url stringlengths 14 1.76k | text stringlengths 100 1.02M | metadata stringlengths 1.06k 1.1k |
|---|---|---|
http://mathematicaloncology.blogspot.com/2015/03/the-overshoot-and-phenotypic.html | # The overshoot and phenotypic equilibrium in characterizing cancer dynamics of reversible phenotypic plasticity
The paradigm of phenotypic plasticity indicates reversible relations of different cancer cell phenotypes, which challenges the cellular hierarchy proposed by the conventional cancer stem cell (CSC) theory. Since the validity of the reversible model versus the hierarchical model of cancer cells is still experimentally debated, it is worthwhile to theoretically explore the dynamic behavior characterizing the reversible model in comparison of the hierarchical model. By comparing the two models in predicting the cell-state dynamics observed in biological experiments, our results imply that the reversible model has advantages over the hierarchical model in predicting both long-term stable and short-term transient dynamics of cancer cells. In particular, it is found that i) the reversible model can predict the phenotypic equilibrium better than the hierarchical model, namely, the stability of the phenotypic mixture of cancer cells is more rooted in the reversible model; ii) the reversible model can perform various types of overshoot behavior, whereas the hierarchical model can never predict the overshoot of CSCs proportion. These also indicate that the phenotypic equilibrium and overshoot can be good candidates to characterize the models with the reversible phenotypic plasticity.
http://arxiv.org/abs/1503.04558 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8205289244651794, "perplexity": 1567.1856812831484}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218189534.68/warc/CC-MAIN-20170322212949-00378-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://ncmm.karlin.mff.cuni.cz/publications/ | # Publications
We are still trying to figure out the best way how to combine several preprints databases that exists at various institutions. Temporarily, we decided to adopt a non-automated insertion of preprints. If you want to insert a preprint to Nečas center database, please send it to preprint-ncmm@karlin.mff.cuni.cz (Jana Pešková).
The legacy preprint database of the "old" Nečas center can be found here or here.
2021
Preprint Bulíček, Miroslav; Hruška, David and Málek, Josef: On evolutionary problems with a-priori bounded gradients, 2021. [Submitted] [bibtex] [ris]
Preprint Bathory, Michal; Bulíček, Miroslav and Málek, Josef: Global weak solution of the diffusive Johnson-Segalman model of a viscoelastic heat-conducting fluid, 2021. [Submitted] [bibtex] [ris]
Article Bathory, Michal; Bulíček, Miroslav and Málek, Josef: Large data existence theory for three-dimensional unsteady flows of rate-type viscoelastic fluids with stress diffusion, Advances in Nonlinear Analysis, Vol. 10, No. 1, pp. 501--521, 2021. [DOI:10.1515/anona-2020-0144] [Published] [bibtex] [ris]
2020
Article Beck, Lisa; Bulíček, Miroslav and Gmeineder, Franz: On a Neumann problem for variational functionals of linear growth, Ann. Sc. Norm. Super. Pisa Cl. Sci. (5), Vol. XXI, pp. 695--737, 2020. [DOI:10.2422/2036-2145.201802_005] [Published] [bibtex] [ris]
Preprint Bulíček, Miroslav; Patel, Victoria; Şengül, Yasemin and Süli, Endre: Existence and uniqueness of global weak solutions to strain-limiting viscoelasticity with Dirichlet boundary data, 2020. [Submitted] [bibtex] [ris]
Preprint Bulíček, Miroslav; Patel, Victoria; Şengül, Yasemin and Süli, Endre: Existence of large-data global weak solutions to a model of a strain-limiting viscoelastic body, 2020. [Submitted] [bibtex] [ris]
Preprint Abbatiello, Anna; Bulíček, Miroslav and Maringová, Erika: On the dynamic slip boundary condition for Navier--Stokes-like problems, 2020. [Submitted] [bibtex] [ris]
Preprint Feireisl, Eduard and Novotný, Antonín: Navier-Stokes-Fourier system with general boundary conditions, 2020. [Submitted] [bibtex] [ris]
Article Dostalík, Mark; Málek, Josef; Průša, Vít and Süli, Endre: A simple construction of a thermodynamically consistent mathematical model for non-isothermal flows of dilute compressible polymeric fluids, Fluids, Vol. 5, No. 3, pp. 133, 2020. [DOI:10.3390/fluids5030133] [Published] [bibtex] [ris]
Preprint Bulíček, Miroslav; Málek, Josef and Maringová, Erika: On nonlinear problems of parabolic type with implicit constitutive equations involving flux, 2020. [Submitted] [bibtex] [ris]
Preprint Bulíček, Miroslav; Málek, Josef; Průša, Vít and Süli, Endre: On incompressible heat-conducting viscoelastic rate-type fluids with stress-diffusion and purely spherical elastic response, 2020. [Submitted] [bibtex] [ris]
Preprint Bulíček, Miroslav; Frehse, Jens and Specovius-Neugebauer, Maria: Regularity results for two standard models in elasto-perfect-plasticity theory with hardening, 2020. [Submitted] [bibtex] [ris]
Preprint Abbatiello, Anna; Bulíček, Miroslav; Los, Tomáš; Málek, Josef and Souček, Ondřej: On unsteady flows of pore pressure-activated granular materials, 2020. [Submitted] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr; Kalousek, Martin and Świerczewska-Gwiazda, Agnieszka: Existence and homogenization of nonlinear elliptic systems in nonreflexive spaces, Nonlinear Analysis, Vol. 194, 2020. [DOI:10.1016/j.na.2019.03.010] [Published] [bibtex] [ris]
Preprint Gergelits, Tomáš; Nielsen, Bjørn Fredrik and Strakoš, Zdeněk: Generalized spectrum of second order differential operators, 2020. [Submitted] [bibtex] [ris]
Article Bathory, Michal; Bulíček, Miroslav and Souček, Ondřej: Existence and qualitative theory for nonlinear elliptic systems with a nonlinear interface condition used in electrochemistry, Z. Angew. Math. Phys., Vol. 71, No. 3, pp. Article 74, 2020. [DOI:10.1007/s00033-020-01293-w] [Published] [bibtex] [ris]
Article Cehula, Jakub and Průša, Vít: Computer modelling of origami-like structures made of light activated shape memory polymers, International Journal of Engineering Science, Vol. 150, pp. 103235, 2020. [DOI:10.1016/j.ijengsci.2020.103235] [Published] [bibtex] [ris]
Article Pozza, Stefano and Simoncini, Valeria: Functions of rational Krylov space matrices and their decay properties, Numerische Mathematik, 2020. [Submitted] [bibtex] [ris]
Article Průša, Vít; Rajagopal, K. R. and Tůma, Karel: Gibbs free energy based representation formula within the context of implicit constitutive relations for elastic solids, International Journal of Non-Linear Mechanics, Vol. 121, pp. 103433, 2020. [DOI:10.1016/j.ijnonlinmec.2020.103433] [Published] [bibtex] [ris]
2019
Article Bulíček, Miroslav; Málek, Josef and Průša, Vít: Thermodynamics and stability of non-equilibrium steady states in open systems, Entropy, Vol. 21, No. 7, pp. 704, 2019. [DOI:10.3390/e21070704] [Published] [bibtex] [ris]
Article Dostalík, Mark; Průša, Vít and Tůma, Karel: Finite amplitude stability of internal steady flows of the Giesekus viscoelastic rate-type Fluid, Entropy, Vol. 21, No. 12, pp. 1219, 2019. [DOI:10.3390/e21121219] [Published] [bibtex] [ris]
Article Dostalík, Mark; Průša, Vít and Skřivan, Tomáš: On diffusive variants of some classical viscoelastic rate-type models, AIP Conference Proceedings, Vol. 2107, pp. 020002, 2019. [DOI:10.1063/1.5109493] [Published] [bibtex] [ris]
Article Janečka, Adam; Málek, Josef; Průša, Vít and Tierra Chica, Giordano: Numerical scheme for simulation of transient flows of non-newtonian fluids characterised by a non-monotone relation between the symmetric part of the velocity gradient and the Cauchy stress tensor, Acta Mechanica, Vol. 230, No. 3, pp. 729-747, 2019. [DOI:10.1007/s00707-019-2372-y] [Published] [bibtex] [ris]
Preprint Dolgov, Sergey and Vejchodský, Tomáš: Guaranteed a posteriori error bounds for low rank tensor approximate solutions, 2019. [Submitted] [bibtex] [ris]
Preprint Liu, Xuefeng and Vejchodský, Tomáš: Rigorous and fully computable a posteriori error bounds for eigenfunctions, 2019. [Submitted] [bibtex] [ris]
Preprint Pozza, Stefano and Pranić, Miroslav: The Gauss quadrature for general linear functionals, Lanczos algorithm, and minimal partial realization, 2019. [Submitted] [bibtex] [ris]
Article Bulíček, Miroslav; Feireisl, Eduard and Málek, Josef: On a class of compressible viscoelastic rate-type fluids with stress--diffusion, Nonlinearity, Vol. 32, No. 12, pp. 4665--4681, 2019. [DOI:10.1088/1361-6544/ab3614] [Published] [bibtex] [ris]
Article Abbatiello, Anna; Bulíček, Miroslav and Kaplický, Petr: On the existence of classical solution to the steady flows of generalized Newtonian fluid with concentration dependent power-law index, J. Math. Fluid Mech., Vol. 21, No. 1, pp. Art. 15, 22 pp., 2019. [DOI:10.1007/s00021-019-0415-8] [Published] [bibtex] [ris]
Article Pozza, Stefano and Strakoš, Zdeněk: Algebraic description of the finite Stieltjes moment problem, Linear Algebra and its Applications, Vol. 561, pp. 207-227, 2019. [DOI:https://doi.org/10.1016/j.laa.2018.09.026] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr; Kalousek, Martin and Świerczewska-Gwiazda, Agnieszka: Homogenization of nonlinear elliptic systems in nonreflexive Musielak-Orlicz spaces, Nonlinearity, Vol. 32, No. 3, pp. 1073--1110, 2019. [DOI:10.1088/1361-6544/aaf259] [Published] [bibtex] [ris]
2018
Preprint Ainsworth, Mark and Vejchodský, Tomáš: A Simple Approach to Reliable and Robust A Posteriori Error Estimation for Singularly Perturbed Problems, 2018. [Submitted] [bibtex] [ris]
Article Hnětynková, Iveta and Tichý, Petr: Characterization of half-radial matrices, Linear Algebra and its Applications, Vol. 559, pp. 227-243, 2018. [DOI:10.1016/j.laa.2018.09.012] [Published] [bibtex] [ris]
Article Meurant, Gérard and Tichý, Petr: Approximating the extreme Ritz values and upper bounds for the A-norm of the error in CG, Numerical Algorithms, Vol. online first, 2018. [DOI:10.1007/s11075-018-0634-8] [Accepted] [bibtex] [ris]
Preprint Bathory, Michal and Bulíček, Miroslav: Optimal outflow boundary condition for a stationary flow of an incompressible fluid, 2018. [Submitted] [bibtex] [ris]
Preprint Henrion, Didier; Kružík, Martin and Weisser, Tillmann: Optimal control problems with oscillations, concentrations and discontinuities, 2018. [In preparation] [bibtex] [ris]
Preprint Grandi, Diego; Kružík, Martin; Mainini, Edoardo and Stefanelli, Ulisse: A phase-field approach to Eulerian interfacial energies, 2018. [In preparation] [bibtex] [ris]
Article Hrnčíř, Jakub; Pultarová, Ivana and Strakoš, Zdeněk: Decomposition into subspaces preconditioning: abstract framework, SIAM, 2018. [Submitted] [bibtex] [ris]
Article Pozza, Stefano; Pranić, Miroslav and Strakoš, Zdeněk: The Lanczos algorithm and complex Gauss quadrature, ETNA (ACTA17 Proceedings), Vol. 50, pp. 1-19, 2018. [DOI:https://doi.org/10.1553/etna_vol50s1] [Submitted] [bibtex] [ris]
Article Liesen, Jörg and Tichý, Petr: The field of values bound on ideal GMRES, SIMAX, 2018. [Submitted] [bibtex] [ris]
Article Echeverría, Carlos; Liesen, Jörg; Szyld, Daniel B. and Tichý, Petr: Convergence of the multiplicative Schwarz method for singularly perturbed convection-diffusion problems discretized on a Shishkin mesh, Electronic Transactions on Numerical Analysis (ETNA), Vol. 48, pp. 40-62, 2018. [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Maringová, Erika; Stroffolini, Bianca and Verde, Anna: A boundary regularity result for minimizers of variational integrals with nonstandard growth, Nonlinear Analysis, Vol. Nonlinear Anal., No. 177, pp. 153--168, 2018. [DOI:10.1016/j.na.2018.03.001] [Published] [bibtex] [ris]
Article Bensoussan, Alain; Bulíček, Miroslav and Frehse, Jens: Bellman systems with mean field dependent dynamics, Chin. Ann. Math. Ser. B, Vol. 39, No. 3, pp. 461--486, 2018. [DOI:10.1007/s11401-018-0078-4] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Kalousek, Martin; Kaplický, Petr and Mácha, Václav: Gradient $L^q$ theory for a class of non-diagonal nonlinear elliptic systems, Nonlinear Analysis, Vol. 171, pp. 156--169, 2018. [DOI:10.1016/j.na.2018.02.004] [Published] [bibtex] [ris]
Article Carson, E. C.; Rozložník, Miroslav; Strakoš, Zdeněk; Tichý, Petr and Tůma, Miroslav: The Numerical Stability Analysis of Pipelined Conjugate Gradient Methods: Historical Context and Methodology, SIAM J. Sci. Comput., Vol. 40, No. 5, pp. A3549–A3580, 2018. [DOI:10.1137/16M1103361] [Published] [bibtex] [ris]
Article Málek, Josef; Průša, Vít; Skřivan, Tomáš and Süli, Endre: Thermodynamics of viscoelastic rate-type fluids with stress diffusion, Physics of Fluids, Vol. 30, No. 2, 2018. [DOI:10.1063/1.5018172] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Burczak, Jan: Existence and smoothness for a class of $n$D models in elasticity theory of small deformations, ZAMP, Vol. 69, pp. 20, 2018. [DOI:10.1007/s00033-018-0917-x] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Frehse, Jens: A revision of results for standard models in elasto-perfect-plasticity theory, Calculus of Variations and Partial Differential Equations, Vol. 57, No. 2, pp. Article 50, 2018. [DOI:10.1007/s00526-018-1322-1] [Published] [bibtex] [ris]
Article Kurka, Ondřej: Tsirelson-like spaces and complexity of classes of Banach spaces, Rev. R. Acad. Cienc. Exactas Fís. Nat. Ser. A Math. RACSAM, Vol. 112, No. 4, pp. 1101-1123, 2018. [DOI:10.1007/s13398-017-0412-9] [Published] [bibtex] [ris]
Chapter Průša, Vít and Rajagopal, K. R.: A new class of models to describe the response of electrorheological and other field dependent fluids, in: Generalized models and non-classical approaches in complex materials 1, Springer, 2018. [DOI:10.1007/978-3-319-72440-9_35] [Published] [bibtex] [ris]
Article Tůma, Karel; Stein, Judith; Průša, Vít and Friedmann, Elfriede: Motion of the vitreous humour in a deforming eye–fluid-structure interaction between a nonlinear elastic solid and viscoleastic fluid, Applied Mathematics and Computation, Vol. 335, pp. 50-64, 2018. [DOI:10.1016/j.amc.2018.04.030] [Published] [bibtex] [ris]
2017
Article Du, Kui; Duintjer Tebbens, Jurjen and Meurant, Gérard: Any admissible harmonic Ritz value set is possible for GMRES, ETNA, Vol. 47, pp. 37--56, 2017. [URL:http://etna.mcs.kent.edu/volum...] [Published] [bibtex] [ris]
Preprint Morikuni, Keiichi and Rozložník, Miroslav: On GMRES for singular EP and GP systems, 2017. [Submitted] [bibtex] [ris]
Preprint Rebollo-Neira, Laura; Rozložník, Miroslav and Sasmal, Pradip: Analysis of a low memory implementation of the Orthogonal Matching Pursuit greedy strategy, 2017. [Submitted] [bibtex] [ris]
Article Hall, Frank J.; Zhongshan, Li; Parnass, Caroline T. and Rozložník, Miroslav: Sign patterns of J-orthogonal matrices, Special Matrices, Vol. 5, No. 1, pp. 225-241, 2017. [DOI:10.1515/spma-2017-0016] [Published] [bibtex] [ris]
Preprint Hrnčíř, Jakub; Pultarová, Ivana and Strakoš, Zdeněk: Decomposition into subspaces and operator preconditioning, 2017. [Submitted] [bibtex] [ris]
Preprint Mácha, Václav and Schwarzacher, Sebastian: Global BMO estimates for non-Newtonian fluids with perfect slip boundary conditions, 2017. [Submitted] [bibtex] [ris]
Article Balázsová, Monika; Feistauer, Miloslav and Vlasák, Miloslav: Stability of the ALE space-time discontinuous Galerkin method for nonlinear convection-diffusion problems in time-dependent domains, Mathematical Modelling and Numerical Analysis, 2017. [Submitted] [bibtex] [ris]
Preprint Anguige, K.; Dondl, P. and Kružík, Martin: ON THE EXISTENCE OF MINIMISERS FOR STRAIN-GRADIENT SINGLE-CRYSTAL PLASTICITY [bibtex] [ris]
Article Švihlová, Helena; Hron, Jaroslav; Málek, Josef; Rajagopal, K. R. and Rajagopal, K.: Determination of pressure data from velocity data with a view towards its application in cardiovascular mechanics. Part 2: a study of aortic valve stenosis., International Journal of Engineering Science, 2017. [Accepted] [bibtex] [ris]
Article Bulíček, Miroslav; Pokorný, Milan and Zamponi, Nicola: Existence analysis for incompressible fluid model of electrically charged chemically reacting and heat conducting mixtures, SIAM J. Math. Anal., Vol. 49, No. 5, pp. 3776--3830, 2017. [DOI:10.1137/16M110931X] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Kalousek, Martin and Kaplický, Petr: Homogenization of a stationary flow of an electrorheological fluid, Annali di Matematica Pura ed Applicata, Vol. 196, No. 3, pp. 1185--1202, 2017. [DOI:10.1007/s10231-016-0612-5] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef; Průša, Vít and Süli, Endre: PDE analysis of a class of thermodynamically compatible viscoelastic rate-type fluids with stress-diffusion, Contemporary Mathematics, American Mathematical Society, 2017. [Submitted] [bibtex] [ris]
Article Stein, Judith and Průša, Vít: Viscoelastic rate type fluids with temperature dependent material parameters – stability of the rest state, AIP Conf. Proc., Vol. 1843, pp. 020004, 2017. [DOI:10.1063/1.4982979] [Published] [bibtex] [ris]
Article Hron, Jaroslav; Miloš, Vojtěch; Průša, Vít; Souček, Ondřej and Tůma, Karel: On thermodynamics of incompressible viscoelastic rate type fluids with temperature dependent material coefficients, International Journal of Non-Linear Mechanics, Vol. 95, pp. 193–208, 2017. [DOI:10.1016/j.ijnonlinmec.2017.06.011] [Published] [bibtex] [ris]
Preprint Kulvait, Vojtěch; Málek, Josef and Rajagopal, K. R.: Modeling Gum Metal and other newly developed titanium alloys within a new class of constitutive relations for elastic bodiestic bodies, 2017. [Submitted] [bibtex] [ris]
Preprint Feireisl, Eduard and Novotný, Antonín: Stationary solutions to the compressible Navier-Stokes system with general boundary conditions, 2017. [Submitted] [bibtex] [ris]
Article Průša, Vít; Řehoř, Martin and Tůma, Karel: Colombeau algebra as a mathematical tool for investigating step load and step deformation of systems of nonlinear springs and dashpots, Zeitschrift für angewandte Mathematik und Physik, Vol. 68, No. 24, 2017. [DOI:10.1007/s00033-017-0768-x] [Published] [bibtex] [ris]
Article Kopal, Jiří; Rozložník, Miroslav and Tůma, Miroslav: An adaptive multilevel factorized sparse approximate inverse preconditioning, Advances in Engineering Software, Vol. 113, pp. 19-24, 2017. [DOI:10.1016/j.advengsoft.2016.10.005] [Published] [bibtex] [ris]
Preprint Bulíček, Miroslav; Cupini, Giovanni; Stroffolini, Bianca and Verde, Anna: Existence and regularity results for weak solutions to $(p,q)$-elliptic systems in divergence form, 2017. [DOI:10.1515/acv-2016-0054] [Accepted] [bibtex] [ris]
Article Beck, Lisa; Bulíček, Miroslav and Maringová, Erika: Globally Lipschitz minimizers for variational problems with linear growth, ESAIM: COCV, 2017. [DOI:10.1051/cocv/2017065] [Accepted] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr and Świerczewska-Gwiazda, Agnieszka: On unified theory for scalar conservation laws with fluxes and sources being discontinuous with respect to the unknown, Journal of Differential Equations, Vol. 262, No. 1, pp. 313--364, 2017. [DOI:10.1016/j.jde.2016.09.020] [Published] [bibtex] [ris]
Preprint Papež, Jan and Strakoš, Zdeněk: On a residual-based a posteriori error estimator for the total error, 2017. [Published] [bibtex] [ris]
Article Papež, Jan; Strakoš, Zdeněk and Vohralík, Martin: Estimating and localizing the algebraic and total numerical errors using flux reconstructions, Numerische Mathematik, pp. 1-41, 2017. [DOI:10.1007/s00211-017-0915-5] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Glitzky, Annegret and Liero, Matthias: Thermistor systems of p(x)-Laplace-type with discontinuous exponents via entropy solutions, Discrete and Continuous Dynamical Systems - Series S, Vol. 10, No. 4, pp. 697--713, 2017. [DOI:10.3934/dcdss.2017035] [Published] [bibtex] [ris]
Article Diening, Lars; Feireisl, Eduard and Lu, Yong: The inverse of the divergence operator on perforated domains with applications to homogenization problems for the compressible Navier-Stokes system, ESAIM: Control, Optimisation and Calculus of Variations, Vol. 23, No. 3, pp. 851-868, 2017. [DOI:10.1051/cocv/2016016] [Published] [bibtex] [ris]
Article Beck, Lisa; Bulíček, Miroslav; Málek, Josef and Süli, Endre: On the existence of integrable solutions to nonlinear elliptic systems and variational problems with linear growth, Archive for Rational Mechanics and Analysis, Vol. 225, No. 2, pp. 717--769, 2017. [DOI:10.1007/s00205-017-1113-4] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Málek, Josef: Internal flows of incompressible fluids subject to stick-slip boundary conditions, Vietnam Journal of Mathematics, Vol. 45, pp. 2017--220, 2017. [DOI:10.1007/s10013-016-0221-z] [Published] [bibtex] [ris]
Article Camaño, Jessika; Oyarzúa, Ricardo and Tierra Chica, Giordano: Analysis of an augmented mixed-FEM for the Navier-Stokes problem, Mathematics of Computation, Vol. 86, No. 304, pp. 589–615, 2017. [DOI:10.1090/mcom/3124] [Published] [bibtex] [ris]
Article Běhounková, Marie; Choblet, Gael; Tobie, Gabriel; Čadek, Ondřej and Souček, Ondřej: Powering prolonged hydrothermal activity inside Enceladus, Nature Astronomy, Vol. 1, pp. 841-847, 2017. [DOI:10.1038/s41550-017-0289-8] [Published] [bibtex] [ris]
Article Běhounková, Marie; Souček, Ondřej; Čadek, Ondřej and Hron, Jaroslav: Plume activity and tidal deformation of Enceladus influenced by faults and variable ice shell thickness, Astrobiology, Vol. 17, No. 9, pp. 941-954, 2017. [DOI:doi.org/10.1089/ast.2016.1629] [Published] [bibtex] [ris]
Article Kurka, Ondřej and Pokorný, Dušan: Notes on the trace problem for separately convex functions, ESAIM Control Optim. Calc. Var., Vol. 23, pp. 1617-1648, 2017. [DOI:10.1051/cocv/2016066] [Published] [bibtex] [ris]
Article Řehoř, Martin; Blechta, Jan and Souček, Ondřej: On some practical issues concerning the implementation of Cahn-Hilliard-Navier-Stokes type models, International Journal of Advances in Engineering Sciences and Applied Mathematics, Vol. 9, No. 1, pp. 30-39, 2017. [DOI:10.1007/s12572-016-0171-4] [Published] [bibtex] [ris]
Article Souček, Ondřej; Málek, Josef; Orava, Vít and Bothe, Dieter: A continuum model of heterogeneous catalysis: thermodynamic framework for multicomponent bulk and surface phenomena coupled by sorption, International Journal of Engineering Science, 2017. [Submitted] [bibtex] [ris]
2016
Article Pavelka, Michal; Klika, V.; Esen, Ogul and Grmela, Miroslav: A hierarchy of Poisson brackets in non-equilibrium thermodynamics, Physica D: Nonlinear Phenomena, Vol. 335, pp. 54-69, 2016. [DOI:10.1016/j.physd.2016.06.011] [Published] [bibtex] [ris]
Article Pavelka, Michal and Grmela, Miroslav: Braun-Le Chatelier principle in dissipative thermodynamics, Proceedings of Accademia Peloritana dei Pericolanti (2016), 2016. [Accepted] [bibtex] [ris]
Article Švihlová, Helena; Hron, Jaroslav; Málek, Josef; Rajagopal, K. R. and Rajagopal, K.: Determination of pressure data from velocity data with a view toward its application in cardiovascular mechanics. Part 1. Theoretical considerations, International Journal of Engineering Science, Vol. 105, pp. 108 - 127, 2016. [DOI:10.1016/j.ijengsci.2015.11.002] [Published] [bibtex] [ris]
Preprint Roubíček, Tomáš: An energy-conserving time-discretisation scheme for poroelastic media with phase-field fracture emitting waves and heat [bibtex] [ris]
Preprint Kružík, Martin and Valdman, Jan: Computational modeling of magnetic hysteresis with thermal effects [bibtex] [ris]
Article Scott, Jennifer and Tůma, Miroslav: Preconditioning of linear least squares by robust incomplete factorization for implicitly held normal equations, SIAM Journal on Scientific Computing, Vol. 38, No. 6, pp. C603–C623, 2016. [DOI:10.1137/16M105890X] [Published] [bibtex] [ris]
Preprint Baia, Margarida; Krömer, Stefan and Kružík, Martin: Generalized W1,1 - young measures and relaxation of problems with linear growth [bibtex] [ris]
Article Barrenechea, G. R.; John, Volker and Knobloch, Petr: An algebraic flux correction scheme satisfying the discrete maximum principle and linearity preservation on general meshes, Submitted to "Mathematical Models and Methods in Applied Sciences", 2016. [Submitted] [bibtex] [ris]
Preprint Fassbender, H. and Rozložník, Miroslav: On the conditioning of factors in the SR decomposition [bibtex] [ris]
Preprint Benešová, Barbora and Kružík, Martin: Weak lower semicontinuity of integral functionals and applications [bibtex] [ris]
Article Kopal, Jiří; Rozložník, Miroslav and Tůma, Miroslav: Factorized approximate inverses with adaptive dropping, SIAM Journal on Scientific Computing, Vol. 38, No. 3, pp. A1807–A1820, 2016. [DOI:10.1137/15M1030315] [Published] [bibtex] [ris]
Preprint Bárta, Tomáš: Rate of convergence to equilibrium and Lojasiewicz-type estimates [bibtex] [ris]
Article Bárta, Tomáš and Fašagová, Eva: Convergence to equilibrium for solutions of an abstract wave equation with general damping function [bibtex] [ris]
Article Feireisl, Eduard; Kreml, Ondřej; Mácha, Václav and Nečasová, Šárka: On the low Mach number limit of compressible flows in exterior moving domains, Journal of Evolution Equations, Vol. 16, No. 3, pp. 705–722, 2016. [DOI:10.1007/s00028-016-0338-2] [Published] [bibtex] [ris]
Article Málek, Josef; Rajagopal, K. R. and Suková, Petra: Response of a class of mechanical oscillators described by a novel system of differential-algebraic equations, Applications of Mathematics, Vol. 61, No. 1, pp. 79--102, 2016. [DOI:10.1007/s10492-016-0123-0] [Published] [bibtex] [ris]
Article Málek, Josef; Rajagopal, K. R. and Žabenský, Josef: On power-law fluids with the power-law index proportional to the pressure, Applied Mathematics Letters, Vol. 62, pp. 118--123, 2016. [DOI:10.1016/j.aml.2016.07.007] [Published] [bibtex] [ris]
Article Souček, Ondřej; Hron, Jaroslav; Běhounková, Marie and Čadek, Ondřej: Effect of the tiger stripes on the deformation of Saturn's moon Enceladus, Geophysical Research Letters, Vol. 43, No. 14, pp. 7417--7423, 2016. [DOI:10.1002/2016gl069415] [Published] [bibtex] [ris]
Preprint Blechta, Jan; Málek, Josef and Vohralík, Martin: Localization of the $W^{-1,q}$ norm for local a posteriori efficiency, 2016. [URL:https://hal.inria.fr/hal-01332...] [Submitted] [bibtex] [ris]
Preprint Bulíček, Miroslav and Málek, Josef: Large data analysis for Kolmogorov's two-equation model of turbulence, 2016. [Submitted] [bibtex] [ris]
Article Řehoř, Martin; Průša, Vít and Tůma, Karel: On the response of nonlinear viscoelastic materials in creep and stress relaxation experiments in the lubricated squeeze flow setting, Physics of Fluids, Vol. 28, No. 10, pp. 103102, 2016. [DOI:10.1063/1.4964662] [Published] [bibtex] [ris]
Preprint Bulíček, Miroslav; Kalousek, Martin and Kaplický, Petr: On homogenization of stationary flows of incompressible non-Newtonian fluids and the uniform continuity of the maximal function in the spaces with highly oscillating variable exponent, 2016. [Submitted] [bibtex] [ris]
Article Bulíček, Miroslav; Burczak, Jan and Schwarzacher, Sebastian: A unified theory for some non Newtonian fluids under singular forcing, SIAM J. Math. Anal, Vol. 48, No. 6, pp. 4241--4267, 2016. [DOI:10.1137/16M1073881] [Published] [bibtex] [ris]
Article Janečka, Adam; Průša, Vít and Rajagopal, K. R.: Euler–Bernoulli type beam theory for elastic bodies with nonlinear response in the small strain range, Archives of Mechanics, Vol. 68, No. 1, pp. 3-25, 2016. [URL:http://am.ippt.pan.pl/am/artic...] [Published] [bibtex] [ris]
Article Průša, Vít and Rajagopal, K. R.: On the response of physical systems governed by non-linear ordinary differential equations to step input, International Journal of Non-Linear Mechanics, Vol. 81, pp. 207–221, 2016. [DOI:10.1016/j.ijnonlinmec.2015.10.013] [Published] [bibtex] [ris]
Preprint Bulíček, Miroslav; Kaplický, Petr and Pražák, Dalibor: Time regularity of non-Newtonian fluid with critial growth, 2016. [Submitted] [bibtex] [ris]
Article Bulíček, Miroslav and Schwarzacher, Sebastian: Existence of very weak solutions to elliptic systems of p-Laplacian type, Calc. Var. Partial Differential Equations, Vol. 55, No. 3, pp. 55:52, 2016. [DOI:10.1007/s00526-016-0986-7] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Lu, Yong and Süli, Endre: Dissipative weak solutions to compressible Navier–Stokes–Fokker–Planck systems with variable viscosity coefficients, Journal of Mathematical Analysis and Applications, Vol. 443, No. 1, pp. 322–351, 2016. [DOI:10.1016/j.jmaa.2016.05.030] [Published] [bibtex] [ris]
Preprint Lu, Yong: Uniform estimates for Stokes equations in domains with small holes and applications in homogenization problems, 2016. [URL:http://arxiv.org/abs/1510.0167...] [Submitted] [bibtex] [ris]
Article Bulíček, Miroslav; Glitzky, Annegret and Liero, Matthias: Systems describing electrothermal effects with p(x)-Laplacian like structure for discontinuous variable exponents, SIAM J. Math. Anal.,, Vol. 48, No. 5, pp. 3496--3514, 2016. [DOI:10.1137/16M1062211] [Published] [bibtex] [ris]
Article Guillén-González, Francisco; Rodríguez-Bellido, Maria Angeles and Tierra Chica, Giordano: Linear unconditional energy-stable splitting schemes for a phase-field model for Nematic-Isotropic flows with anchoring effects, International Journal for Numerical Methods in Engineering (IJNME), Vol. 108, No. 6, pp. 535–567, 2016. [DOI:10.1002/nme.5221] [Published] [bibtex] [ris]
Article Málek, Josef; Rajagopal, K. R. and Tůma, Karel: A thermodynamically compatible model for describing asphalt binders: solutions of problems, International Journal of Pavement Engineering, Vol. 17, No. 6, pp. 550-564, 2016. [DOI:10.1080/10298436.2015.1007575] [Published] [bibtex] [ris]
Article Camaño, Jessika; Gatica, Gabriel N.; Oyarzúa, Ricardo and Tierra Chica, Giordano: An augmented mixed finite element method for the Navier-Stokes equations with variable viscosity, SIAM Journal on Numerical Analysis, Vol. 54, No. 2, pp. 1069–1092, 2016. [DOI:10.1137/15M1013146] [Published] [bibtex] [ris]
Article Bonnivard, Matthieu; Suárez-Grau, Francisco J. and Tierra Chica, Giordano: On the influence of wavy riblets on the slip behaviour of viscous fluids, Zeitschrift für angewandte Mathematik und Physik (ZAMP), Vol. 67, No. 2, pp. 67:27, 2016. [DOI:10.1007/s00033-015-0614-y] [Published] [bibtex] [ris]
Article Řehoř, Martin and Průša, Vít: Squeeze flow of a piezoviscous fluid, Applied Mathematics and Computation, Vol. 274, pp. 414–429, 2016. [DOI:10.1016/j.amc.2015.11.008] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Diening, Lars and Schwarzacher, Sebastian: Existence, uniqueness and optimal regularity results for very weak solutions to nonlinear elliptic systems, Anal. PDE, Vol. 9, No. 5, pp. 1115--1151, 2016. [DOI:10.2140/apde.2016.9.1115] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr; Świerczewska-Gwiazda, Agnieszka and Süli, Endre: Analysis of a viscosity model for concentrated polymers, Mathematical Models and Methods in Applied Sciences (M3AS), Vol. 26, No. 8, pp. 1599–1648, 2016. [DOI:10.1142/S0218202516500391] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Lu, Yong and Málek, Josef: On PDE analysis of flows of quasi-incompressible fluids, Zeitschrift für Angewandte Mathematik und Mechanik (ZAMM), Vol. 96, No. 4, pp. 491–508, 2016. [DOI:10.1002/zamm.201400229] [Published] [bibtex] [ris]
Article Gatica, Gabriel N.; Ruiz-Baier, Ricardo and Tierra Chica, Giordano: A mixed finite element method for Darcy’s equations with pressure dependent porosity, Mathematics of Computation, Vol. 85, pp. 1--33, 2016. [DOI:10.1090/mcom/2980] [Published] [bibtex] [ris]
Chapter Bulíček, Miroslav and Málek, Josef: On Unsteady Internal Flows of Bingham Fluids Subject to Threshold Slip on the Impermeable Boundary, in: Recent Developments of Mathematical Fluid Mechanics, pages 135--156, Birkhauser, 2016. [DOI:10.1007/978-3-0348-0939-9_8] [Published] [bibtex] [ris]
Hnětynková, Iveta; Kubínová, Marie and Plešinger, Martin: Notes on performance of bidiagonalization-based estimator in image deblurring, in: Proceedings of Algoritmy 2016 - 20th Conference on Scientific Computing, pages 333--342, 2016. [Published] [bibtex] [ris]
Article Hnětynková, Iveta; Plešinger, Martin and Sima, Diana Maria: Solvability of the core problem with multiple right-hand sides in the TLS sense, SIAM J. on Matrix Anal. and Appl., Vol. 37, No. 3, pp. 861--876, 2016. [DOI:10.1137/15M1028339] [Published] [bibtex] [ris]
Article Kalousová, Klára; Souček, Ondřej; Tobie, Gabriel; Choblet, Gael and Čadek, Ondřej: Water generation and transport below Europa's strike-slip faults, JGR-Planets, No. 121, 2016. [DOI:doi:10.1002/2016JE005188] [Published] [bibtex] [ris]
Article Kurka, Ondřej: Zippin's embedding theorem and amalgamations of classes of Banach spaces, Proc. Amer. Math. Soc., Vol. 144, pp. 4273-7277, 2016. [DOI:10.1090/proc/13045] [Published] [bibtex] [ris]
Article Kurka, Ondřej: Amalgamations of classes of Banach spaces with a monotone basis, Studia Mathematica, Vol. 234, pp. 121-148, 2016. [DOI:10.4064/sm8281-7-2016] [Published] [bibtex] [ris]
Article Kurka, Ondřej: Non-universal families of separable Banach spaces, Studia Mathematica, Vol. 233, pp. 153-168, 2016. [DOI:10.4064/sm8380-4-2016] [Published] [bibtex] [ris]
2015
Article Duintjer Tebbens, Jurjen and Meurant, Gérard: On the Convergence of QOR and QMR Krylov Methods for Solving Nonsymmetric Linear Systems, BIT Numerical Mathematics, 2015. [Submitted] [bibtex] [ris]
Article Šístek, Jakub and Cirak, Fehmi: Parallel iterative solution of the incompressible Navier–Stokes equations with application to rotating wings, Computers & Fluids, Vol. 122, pp. 165–183, 2015. [DOI:10.1016/j.compfluid.2015.08.026] [Accepted] [bibtex] [ris]
Preprint Dolejší, Vít: Anisotropic hp-adaptive method based on interpolation error estimates in the H1-seminorm, 2015. [Accepted] [bibtex] [ris]
Article Hnětynková, Iveta and Plešinger, Martin: Complex wedge-shaped matrices: A generalization of Jacobi matrices [DOI:10.1016/j.laa.2015.09.017] [bibtex] [ris]
Preprint Knuepfer, Hans and Kružík, Martin: A sharp interface evolutionary model for shape memory alloys [bibtex] [ris]
Preprint Roubíček, Tomáš and Tomassetti, Giuseppe: Thermomechanics of damageable materials under diffusion: modeling and analysis [bibtex] [ris]
Article Kolář, Václav and Šístek, Jakub: Corotational and Compressibility Aspects Leading to a Modification of the Vortex-Identification Q-Criterion, AIAA Journal, Vol. 53, No. 8, pp. 2406-2410, 2015. [DOI:10.2514/1.J053697] [Published] [bibtex] [ris]
Article Dolejší, Vít; Roskovec, Filip and Vlasák, Miloslav: Residual based error estimates for the space-time discontinuous Galerkin method applied to the compressible flows [DOI:10.1016/j.compfluid.2015.05.027] [bibtex] [ris]
Preprint Dolejší, Vít and Solin, Pavel: hp-discontinuous Galerkin method based on local higher order reconstruction, 2015. [Submitted] [bibtex] [ris]
Article Dolejší, Vít: Anisotropic hp-adaptive discontinuous Galerkin method for the numerical solution of time dependent PDEs [DOI:10.1016/j.amc.2014.12.099] [bibtex] [ris]
Article Šístek, Jakub; Březina, Jan and Sousedík, Bedřich: BDDC for Mixed-Hybrid Formulation of Flow in Porous Media with Combined Mesh Dimensions, Numerical Linear Algebra with Applications, Vol. 22, No. 6, pp. 903-929, 2015. [DOI:10.1002/nla.1991] [Published] [bibtex] [ris]
Article Hnětynková, Iveta; Plešinger, Martin and Strakoš, Zdeněk: Band generalization of the Golub-Kahan bidiagonalization, generalized Jacobi matrices, and the core problem, SIAM Journal on Matrix Analysis and Applications, Vol. 36, No. 2, pp. 417-434, 2015. [DOI:10.1137/140968914] [Published] [bibtex] [ris]
Preprint Vejchodský, Tomáš; Jaroš, Filip; Kučera, Milan and Rybář, Vojtěch: Unilateral regulation breaks regularity of turing patterns, 2015. [Submitted] [bibtex] [ris]
Article Feireisl, Eduard; Kreml, Ondřej and Vasseur, Alexis: Stability of the isentropic Riemann solutions of the full multidimensional Euler system, SIAM Journal on Mathematical Analysis, Vol. 47, No. 3, pp. 2416–2425, 2015. [DOI:10.1137/140999827] [Published] [bibtex] [ris]
Article Bárta, Tomáš; Janeček, V. and Pražák, Dalibor: Heat conduction problem of an evaporating liquid wedge, Electron. J. Diff. Equ., Vol. 2015, No. 53, 2015. [Submitted] [bibtex] [ris]
Article Bai, Zhong-Zhi and Rozložník, Miroslav: On numerical behavior of matrix splitting iteration methods, SIAM Journal on Numerical Analysis (SINUM), Vol. 53, No. 4, pp. 1116-1137, 2015. [DOI:10.1137/140987936] [Published] [bibtex] [ris]
Article Feireisl, Eduard and Kreml, Ondřej: Uniqueness of rarefaction waves in multidimensional compressible Euler system, Journal of Hyperbolic Differential Equations, Vol. 12, No. 3, pp. 489–499, 2015. [DOI:10.1142/S0219891615500149] [Published] [bibtex] [ris]
Article Tierra Chica, Giordano and Guillén-González, Francisco: Numerical methods for solving the Cahn-Hilliard equation and its applicability to related Energy-based models, Archives of Computational Methods in Engineering, Vol. 22, No. 2, pp. 269--289, 2015. [DOI:10.1007/s11831-014-9112-1] [Published] [bibtex] [ris]
Article Rozložník, Miroslav; Okulicka-Dluzewska, Felicija and Smoktunowicz, Alicja: Cholesky-like factorization of symmetric indefinite matrices and orthogonalization with respect to bilinear forms, SIAM J. Matrix Anal. & Appl., Vol. 36, No. 2, pp. 727-751, 2015. [DOI:10.1137/130947003] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Frehse, Jens and Steinhauer, Mark: Weighted integral techniques and C-alpha-estimates for a class of elliptic systems with p-growth, Annali di Matematica Pura ed Applicata, Vol. 194, No. 4, pp. 1025--1069, 2015. [DOI:10.1007/s10231-014-0410-x] [Published] [bibtex] [ris]
Article Dolejší, Vít; Šebestová, Ivana and Vohralík, Martin: Algebraic and discretization error estimation by equilibrated fluxes for discontinuous Galerkin methods on nonmatching grids, Journal of Scientific Computing, Vol. 64, No. 1, pp. 1–34, 2015. [DOI:10.1007/s10915-014-9921-2] [Published] [bibtex] [ris]
Article Chiodaroli, Elisabetta; Feireisl, Eduard and Kreml, Ondřej: On the weak solutions to the equations of a compressible heat conducting gas, Annales de l'Institut Henri Poincaré. Analyse non Linéaire, Vol. 32, No. 1, pp. 225–243, 2015. [DOI:10.1016/j.anihpc.2013.11.005] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Havrda, Jaroslav: On Existence Of Weak Solution To A Model Describing Incompressible Mixtures With Thermal Diffusion Cross Effects, Z. Angew. Math. Mech., Vol. 95, No. 6, pp. 589--619, 2015. [DOI:10.1002/zamm.201300101] [Published] [bibtex] [ris]
Article Tierra Chica, Giordano; Pavissich, Juan P.; Nerenberg, Robert; Xu, Zhiliang and Alber, Mark S.: Multicomponent model of deformation and detachment of a biofilm under fluid flow, Journal of the Royal Society Interface, Vol. 12, pp. 20150045, 2015. [DOI:10.1098/rsif.2015.0045] [Published] [bibtex] [ris]
Article Málek, Josef; Rajagopal, K. R. and Tůma, Karel: On a variant of the Maxwell and Oldroyd-B models within the context of a thermodynamic basis, International Journal of Non-Linear Mechanics, Vol. 76, pp. 42--47, 2015. [DOI:10.1016/j.ijnonlinmec.2015.03.009] [Published] [bibtex] [ris]
Article Kuchta, Miroslav; Tobie, Gabriel; Miljkovic, Katarina; Běhounková, Marie; Souček, Ondřej and Čadek, Ondřej: Despinning and shape evolution of Saturn's moon Iapetus triggered by a giant impact, Icarus, Vol. 252, pp. 454-465, 2015. [DOI:10.1016/j.icarus.2015.02.010] [Published] [bibtex] [ris]
Article Guidat, Thomas; Pochat, Stephane; Bourgeois, Olivier and Souček, Ondřej: Landform assemblage in Isidis Planitia, Mars: Evidence for a 3 Ga old polythermal ice sheet., Earth and Planetary Science Letters, Vol. 411, pp. 253-267, 2015. [DOI:10.1016/j.epsl.2014.12.002] [Published] [bibtex] [ris]
Article Průša, Vít; Rajagopal, K. R.; Srinivasa, Arun and Yuan, Zhi: Vibrations of a lumped parameter mass-spring-dashpot system wherein the spring is described by a non-invertible elongation-force constitutive function, International Journal of Non-Linear Mechanics, Vol. 76, pp. 154–163, 2015. [DOI:10.1016/j.ijnonlinmec.2015.06.009] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Žabenský, Josef: Large data existence theory for unsteady flows of fluids with pressure- and shear-dependent viscosities, Nonlinear Anal. Theory Methods Appl., Vol. 127, pp. 94--127, 2015. [DOI:10.1016/j.na.2015.07.001] [Published] [bibtex] [ris]
Preprint Bulíček, Miroslav: On existence theory for general nonlinear elliptic and parabolic equations with bad data, 2015. [Submitted] [bibtex] [ris]
Article Feireisl, Eduard and Lu, Yong: Homogenization of the stationary compressible Navier-Stokes equations in domains with tiny holes, Journal of Mathematical Fluid Mechanics, Vol. 17, No. 2, pp. 381–392, 2015. [DOI:10.1007/s00021-015-0200-2] [Published] [bibtex] [ris]
Article Beck, Lisa; Bulíček, Miroslav and Frehse, Jens: Old and new results in regularity theory for diagonal elliptic systems via blow up techniques, J. Differential Equations, Vol. 259, No. 11, pp. 6528--6572, 2015. [DOI:10.1016/j.jde.2015.07.030] [Published] [bibtex] [ris]
Article Perlácová, Tereza and Průša, Vít: Tensorial implicit constitutive relations in mechanics of incompressible non-Newtonian fluids, Journal of non-Newtonian Fluid Mechanics, Vol. 216, pp. 13–21, 2015. [DOI:10.1016/j.jnnfm.2014.12.006] [Published] [bibtex] [ris]
Article Orava, Vít; Souček, Ondřej and Čendula, Peter: Multi-phase modeling of non-isothermal reactive flow in fluidized bed reactors, Journal of Computational and Applied Mathematics, Vol. 289, pp. 282-295, 2015. [DOI:doi:10.1016/j.cam.2015.01.012] [Published] [bibtex] [ris]
Article Guillén-González, Francisco and Tierra Chica, Giordano: Approximation of Smectic-A liquid crystals, Computer Methods in Applied Mechanics and Engineering, Vol. 290, No. 15, pp. 342--361, 2015. [DOI:10.1016/j.cma.2015.03.015] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Žabenský, Josef: On generalized Stokes' and Brinkman's equations with pressure- and shear-dependent viscosity and drag coefficient, Nonlinear Anal. Real World Appl., Vol. 26, pp. 109--132, 2015. [DOI:10.1016/j.nonrwa.2015.05.004] [Published] [bibtex] [ris]
Article Hnětynková, Iveta; Plešinger, Martin and Strakoš, Zdeněk: Band generalization of the Golub--Kahan bidiagonalization, generalized Jacobi matrices, and the core problem, SIAM Journal on Matrix Analysis and Applications, Vol. 36, No. 2, pp. 417–434, 2015. [DOI:10.1137/140968914] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Liao, Xian and Málek, Josef: Global weak solutions to a class of non-Newtonian compressible fluids, Math. Methods Appl. Sci., Vol. 38, No. 16, pp. 3482–3494, 2015. [DOI:10.1002/mma.3432] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Žabenský, Josef: A generalization of the Darcy-Forchheimer equation involving an implicit, pressure-dependent relation between the drag force and the velocity, Journal of Mathematical Analysis and Applications, Vol. 424, No. 1, pp. 785-801, 2015. [DOI:10.1016/j.jmaa.2014.11.053] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Süli, Endre: Analysis and approximation of a strain-limiting nonlinear elastic model, Mathematics and Mechanics of Solids, Vol. 20, No. 1, pp. 92–118, 2015. [DOI:10.1177/1081286514543601] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef; Rajagopal, K. R. and Walton, Jay R.: Existence of solutions for the anti-plane stress for a new class of "strain-limiting" elastic bodies, Calculus of Variations and PDE's, Vol. 54, No. 2, pp. 2115--2147, 2015. [DOI:10.1007/s00526-015-0859-5] [Published] [bibtex] [ris]
2014
Preprint Duintjer Tebbens, Jurjen and Meurant, Gérard: On the admissible convergence curves for restarted GMRES [bibtex] [ris]
Article Vodička, Roman; Mantič, Vladislav and Roubíček, Tomáš: Energetic versus maximally-dissipative local solutions of a quasi-static rate-independent mixed-mode delamination model, Meccanica, 2014. [Accepted] [bibtex] [ris]
Article Meurant, Gérard and Duintjer Tebbens, Jurjen: The role eigenvalues play in forming GMRES residual norms with non-normal matrices, Numerical Algorithms, 2014. [DOI:10.1007/s11075-014-9891-3] [Published] [bibtex] [ris]
Preprint Kreml, Ondřej; Pokorný, Milan and Šalom, Pavel: On the global existence for a regularized model of viscoelastic non-Newtonian fluid, 2014. [Submitted] [bibtex] [ris]
Article Roubíček, Tomáš: A note about the rate-and-state-dependent friction model in a thermodynamical framework of the Biot-type equation, Geophysical Journal International, Vol. 199, No. 1, pp. 286--295, 2014. [DOI:10.1093/gji/ggu248] [Published] [bibtex] [ris]
Preprint Bru, Rafael; Marín, José; Mas, José and Tůma, Miroslav: Preconditioned iterative methods for solving linear least squares problems [bibtex] [ris]
Preprint Kružík, Martin; Stefanelli, Ulisse and Zanini, Chiara: Quasistatic evolution of magnetoelastic thin films via dimension reduction [bibtex] [ris]
Preprint Benešová, Barbora; Krömer, Stefan and Kružík, Martin: Boundary effects and weak lower semicontinuity for signed integral functionals on BV [bibtex] [ris]
Preprint Jüttler, Bert and Šír, Zbyněk: On de Casteljau-type algorithms for rational B´ezier curves [bibtex] [ris]
Preprint Čapek, Marek: A non-newtonian model of blood capturing segregation of erythrocytes, 2014. [In preparation] [bibtex] [ris]
Preprint Axmann, Šimon and Pokorný, Milan: A generalization of some regularity criteria to the Navier-Stokes equations involving one velocity component, 2014. [Accepted] [bibtex] [ris]
Article Blažková, Eva and Šír, Zbyněk: Identifying and Approximating Monotonous Segments of Algebraic Curves Using Support Function Representation, Computer Aided Geometric Design, 2014. [Submitted] [bibtex] [ris]
Article Bastl, Bohumír; Bizzarri, Michal; Kovač, Boštjan; Krajnc, Marjeta; Lávička, Miroslav; Michálková, Kristýna; Počkaj, Karla; Šír, Zbyněk and Žagar, Emil: C 2 Hermite interpolation by Pythagorean-hodograph quintic triarcs, Computer Aided Geometric Design, 2014. [Submitted] [bibtex] [ris]
Article Bastl, Bohumír; Jüttler, Bert; Lávička, Miroslav; Schulz, Tino and Šír, Zbyněk: On the Parameterization of Rational Ringed Surfaces and Rational Canal Surfaces, Mathematics in Computer Science, 2014. [Accepted] [bibtex] [ris]
Article Blažková, Eva and Šír, Zbyněk: Exploiting the Implicit Support Function for a Topologically Accurate Approximation of Algebraic Curves, Lecture Notes in Computer Science, Vol. 8177, pp. 49-67, 2014. [DOI:10.1007/978-3-642-54382-1_4] [Published] [bibtex] [ris]
Article Bastl, Bohumír; Bizzarri, Michal; Krajnc, Marjeta; Lávička, Miroslav; Slabá, K.; Šír, Zbyněk; Vitrih, V. and Žagar, Emil: C 1 Hermite interpolation with spatial Pythagorean-hodograp h cubic biarcs, Journal of Computational and Applied Mathematics, Vol. 257, pp. 65-78, 2014. [DOI:10.1016/j.cam.2013.08.007] [Published] [bibtex] [ris]
Article Panagiotopoulos, Christos G.; Mantič, Vladislav and Roubíček, Tomáš: A simple and efficient BEM implementation of quasistatic linear visco-elasticity, International Journal of Solids and Structures, 2014. [DOI:10.1016/j.ijsolstr.2014.02.028] [Accepted] [bibtex] [ris]
Preprint Kružík, Martin; Stefanelli, Ulisse and Zeman, Jan: Existence Results for Incompressible Magnetoelasticity [bibtex] [ris]
Preprint Krämer, Jan; Krömer, Stefan; Kružík, Martin and Pathó, Gabriel: A-quasiconvexity and weak lower semicontinuity of integral functionals [bibtex] [ris]
Article Ainsworth, Mark and Vejchodský, Tomáš: Robust Error Bounds for Finite Element Approximation of Reaction-Diffusion Problems with Non-Constant Reaction Coefficient in Arbitrary Space Dimension [DOI:10.1016/j.cma.2014.08.005] [bibtex] [ris]
Article Vejchodský, Tomáš: Accurate Reduction of a Model of Circadian Rhythms by Delayed Quasi Steady State Assumptions [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Shilkin, Timofei Nikolaevich: On the Regularity of Two-Dimensional Unsteady Flows of Heat-Conducting Generalized Newtonian Fluids, Nonlinear Analysis: Real World Applications, Vol. 19, pp. 89--104, 2014. [DOI:10.1016/j.nonrwa.2014.03.003] [Published] [bibtex] [ris]
Article Bárta, Tomáš: Convergence to equilibrium of relatively compact solutions to evolution equations, Electron. J. Diff. Equ., Vol. 2014, No. 81, pp. 1--9, 2014. [URL:http://ejde.math.txstate.edu/V...] [Published] [bibtex] [ris]
Article Bárta, Tomáš: One-dimensional model describing the non-linear viscoelastic response of materials, Comment. Math. Univ. Carolin., Vol. 55, No. 2, pp. 227--246, 2014. [URL:http://cmuc.karlin.mff.cuni.cz...] [Published] [bibtex] [ris]
Article Bárta, Tomáš: Global existence for a nonlinear model of 1D chemically reacting viscoelastic body, Riv. Mat. Univ. ParmaRiv., Vol. 5, No. 2, pp. 399 - 423, 2014. [Published] [bibtex] [ris]
Article Rozložník, Miroslav; Smoktunowicz, Alicja and Kopal, Jiří: A note on iterative refinement for seminormal equations, Applied Numerical Mathematics, Vol. 75, pp. 167--174, 2014. [DOI:10.1016/j.apnum.2013.08.005] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Pustějovská, Petra: Existence Analysis For a Model Describing Flow of an Incompressible Chemically Reacting Non-Newtonian Fluid, SIAM Journal on Mathematical Analysis, Vol. 46, No. 5, pp. 3223--3240, 2014. [DOI:10.1137/130927589] [Published] [bibtex] [ris]
Article Duintjer Tebbens, Jurjen and Tůma, Miroslav: On Incremental Condition Estimators in the 2-Norm, SIAM. J. Matrix Anal. & Appl., Vol. 35, No. 1, pp. 174--197, 2014. [DOI:10.1137/130922872] [Published] [bibtex] [ris]
Article Šebestová, Ivana and Vejchodský, Tomáš: Two-sided bounds for eigenvalues of differential operators with applications to Friedrichs', Poincaré, trace, and similar constants [DOI:10.1137/13091467X] [bibtex] [ris]
Article Duintjer Tebbens, Jurjen; Meurant, Gérard; Sadok, Hassane and Strakoš, Zdeněk: On investigating GMRES convergence using unitary matrices, Linear Algebra and its Applications, Vol. 450, No. 1, pp. 83-107, 2014. [DOI:10.1016/j.laa.2014.02.044] [Published] [bibtex] [ris]
Article Kalousová, Klára; Souček, Ondřej; Tobie, Gabriel; Choblet, Gael and Čadek, Ondřej: Ice melting and downward transport of meltwater by two-phase flow in Europa's ice shell, JGR-Planets, Vol. 119, No. 3, pp. 532-549, 2014. [DOI:10.1002/2013JE004563] [Published] [bibtex] [ris]
Article Souček, Ondřej; Průša, Vít; Málek, Josef and Rajagopal, K. R.: On the natural structure of thermodynamic potentials and fluxes in the theory of chemically non-reacting binary mixtures, Acta Mechanica, Vol. 225, No. 11, pp. 3157-3186, 2014. [DOI:10.1007/s00707-013-1038-4] [Published] [bibtex] [ris]
Article Souček, Ondřej; Kalousová, Klára and Čadek, Ondřej: Water transport in planetary ice layers - a parametric study, Geophys. Astro. Fluid., Vol. 108, No. 6, pp. 639-666, 2014. [DOI:10.1080/03091929.2014.969251] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef; Rajagopal, K. R. and Süli, Endre: On elastic solids with limiting small strain: modelling and analysis, EMS Surveys in Mathematical Sciences, Vol. 1, No. 2, pp. 283–332, 2014. [DOI:10.4171/EMSS/7] [Published] [bibtex] [ris]
Article Janečka, Adam and Průša, Vít: The motion of a piezoviscous fluid under a surface load, International Journal of Non-Linear Mechanics, Vol. 60, No. 4, pp. 23-32, 2014. [DOI:10.1016/j.ijnonlinmec.2013.12.006] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Lu, Yong and Novotný, Antonín: Rotating compressible fluids under strong stratification, Nonlinear Analysis: Real World Applications, Vol. 19, pp. 11–18, 2014. [DOI:10.1016/j.nonrwa.2014.02.004] [Published] [bibtex] [ris]
Article Gergelits, Tomáš and Strakoš, Zdeněk: Composite convergence bounds based on Chebyshev polynomials and finite precision conjugate gradient computations, Numerical Algoritms, Vol. 65, No. 4, pp. 759-782, 2014. [DOI:10.1007/s11075-013-9713-z] [Published] [bibtex] [ris]
2013
Preprint Chiodaroli, Elisabetta and Kreml, Ondřej: On the energy dissipation rate of solutions to the compressible isentropic Euler system [bibtex] [ris]
Preprint Kalina, Jan and Duintjer Tebbens, Jurjen: Metody pro redukci dimenze v mnohorozměrné statistice a jejich výpočet (in Czech with English Abstract) [bibtex] [ris]
Preprint Kružík, Martin; Panagiotopoulos, Christos G. and Roubíček, Tomáš: Quasistatic adhesive contact delaminating in mixed mode and its numerical treatment [bibtex] [ris]
Preprint Franek, Peter and Ratschan, Stefan: Effective Topological Degree Computation Based on Interval Arithmetic [bibtex] [ris]
Preprint Roubíček, Tomáš: Maximally-dissipative local solutions to rate-independent systems and application to damage and delamination problems, 2013. [Submitted] [bibtex] [ris]
Article Kolář, Václav; Šístek, Jakub; Cirak, Fehmi and Moses, Pavel: Average Corotation of Line Segments Near a Point and Vortex Identification, AIAA Journal, Vol. 51, No. 11, pp. 2678-2694, 2013. [DOI:10.2514/1.J052330] [Published] [bibtex] [ris]
Preprint Benešová, Barbora; Frost, Miroslav and Sedlák, Petr: A microscopically motivated constitutive model for shape memory alloys: formulation, analysis and computations, 2013. [Submitted] [bibtex] [ris]
Preprint Dolejší, Vít and Šíp, Viktor: A parallel fully-implicit discontinuous Galerkin method for the compressible flows, 2013. [Submitted] [bibtex] [ris]
Preprint Dolejší, Vít: Anisotropic hp-adaptive method based on interpolation error estimates in the Lq-norm, 2013. [Submitted] [bibtex] [ris]
Article Roubíček, Tomáš; Souček, Ondřej and Vodička, Roman: A model of rupturing lithospheric faults with re-occurring earthquakes, SIAM J. Appl. Math., Vol. 73, No. 4, pp. 1460--1488, 2013. [DOI:10.1137/120870396] [Published] [bibtex] [ris]
Preprint Bulíček, Miroslav: On Properties of Minimizers to Some Variational Integrals, 2013. [Submitted] [bibtex] [ris]
Preprint Dolejší, Vít: A design of residual error estimates for a high order BDF-DGFEM applied to the compressible flows, 2013. [Accepted] [bibtex] [ris]
Article Dolejší, Vít: hp-DGFEM for nonlinear convection-diffusion problems, Mathematics and Computers in Simulation, Vol. 87, pp. 87-118, 2013. [DOI:10.1016/j.matcom.2013.03.001] [Published] [bibtex] [ris]
Preprint Benešová, Barbora; Kružík, Martin and Pathó, Gabriel: A mesoscopic thermomechanically-coupled model for thin-film shape-memory alloys by dimension reduction and scale transition [bibtex] [ris]
Preprint Feistauer, Miloslav; Horáček, Jaromír and Sváček, Petr: Numerical simulation of vibrations of an airfoil with three degrees of freedom induced by turbulent flow [bibtex] [ris]
Preprint Tichý, Jakub: Regularity of planar flows for shear-thickening fluids under perfect slip boundary conditions [bibtex] [ris]
Preprint Chiodaroli, Elisabetta; De Lellis, Camillo and Kreml, Ondřej: Global ill-posedness of the isentropic system of gas dynamics [bibtex] [ris]
Article Hron, Jaroslav and Pustějovská, Petra: Comparison of stabilized finite element methods for simulation of flow of diluted polymeric liquids [bibtex] [ris]
Preprint Rajagopal, K. R.: Particle free bodies [bibtex] [ris]
Article Průša, Vít and Rajagopal, K. R.: On models for viscoelastic materials that are mechanically incompressible and thermally compressible or expansible and their Oberbeck–Boussinesq type approximations, Mathematical Models and Methods in Applied Sciences, Vol. 23, No. 10, pp. 1761--1794, 2013. [DOI:10.1142/S0218202513500516] [Published] [bibtex] [ris]
Article Hnětynková, Iveta; Plešinger, Martin and Strakoš, Zdeněk: The Core Problem Within a Linear Approximation Problem Ax ≈ B With Multiple Right-Hand Sides, SIAM Journal on Matrix Analysis and Applications, Vol. 34, No. 3, pp. 917-931, 2013. [DOI:10.1137/120884237] [Published] [bibtex] [ris]
Article Bárta, Tomáš: Global existence for a system of nonlocal PDEs with applications to chemically reacting incompressible fluids, Cent. Eur. J. Math., Vol. 11, No. 6, pp. 1112--1128, 2013. [DOI:10.2478/s11533-013-0220-1] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr and Świerczewska-Gwiazda, Agnieszka: Multi-dimensional scalar conservation laws with fluxes discontinuous in the unknown and the spatial variable, Mathematical Models and Methods in Applied Sciences, Vol. 23, No. 3, pp. 407--439, 2013. [DOI:10.1142/S0218202512500510] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Kaplický, Petr and Steinhauer, Mark: On existence of a classical solution to a generalized Kelvin-Voigt model, Pacific J. of Math., Vol. 262, No. 1, pp. 11--33, 2013. [DOI:10.2140/pjm.2013.262.11] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Süli, Endre: Existence of Global Weak Solutions to Implicitly Constituted Kinetic Models of Incompressible Homogeneous Dilute Polymers, Communications in Partial Differential Equations, Vol. 58, No. 5, pp. 882--924, 2013. [DOI:10.1080/03605302.2012.742104] [Published] [bibtex] [ris]
Article Česenek, Jan; Feistauer, Miloslav; Horáček, Jaromír; Kučera, Václav and Prokopová, Jaroslava: Simulation of compressible viscous flow in time-dependent domains, Appl. Math. Comput., Vol. 219, No. 13, 2013. [DOI:10.1016/j.amc.2011.08.077] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Karper, Trygve; Kreml, Ondřej and Stebel, Jan: Stability with respect to domain of the low Mach number limit of compressible viscous fluids, Archive for Rational Mechanics and Analysis, Vol. 23, No. 13, pp. 2465–2493, 2013. [DOI:10.1142/S0218202513500371] [Published] [bibtex] [ris]
2012
Article Bartels, Sören; Mielke, Alexander and Roubíček, Tomáš: Quasistatic small-strain plasticity in the limit of vanishing hardening and its numerical approximation, SIAM J. Numer. Anal., 2012. [Accepted] [bibtex] [ris]
Article Benešová, Barbora; Kružík, Martin and Roubíček, Tomáš: Thermodynamically-consistent mesoscopic model of the ferro/paramagnetic transition, ZAMP - Zeitschrift für Angewandte Mathematik und Physik, 2012. [URL:http://adsabs.harvard.edu/abs/...] [Submitted] [bibtex] [ris]
Article Benešová, Barbora and Roubíček, Tomáš: Micro-to-meso scale limit for shape-memory-alloy models with thermal coupling, Multiscale Modeling and Simulation, 2012. [Submitted] [bibtex] [ris]
Article Bensoussan, Alain; Bulíček, Miroslav and Frehse, Jens: Existence and compactness for weak solutions to Bellman systems with critical growth, Discrete and Continuous Dynamical Systems - Series B, Vol. 17, No. 6, pp. 1729--1750, 2012. [DOI:10.3934/dcdsb.2012.17.1729] [Published] [bibtex] [ris]
Article Bulíček, Miroslav: On continuity properties of monotone operators beyond the natural domain of definition, Manuscripta Mathematica, Vol. 138, No. 3-4, pp. 287--298, 2012. [DOI:10.1007/s00229-011-0506-1] [Published] [bibtex] [ris]
Bulíček, Miroslav; Consiglieri, Luisa and Málek, Josef: Slip boundary effects on unsteady flows of incompressible viscous fluids with a non-linear internal energy-temperature relationship, 2012. [In preparation] [bibtex] [ris]
Article Bulíček, Miroslav and Frehse, Jens: {$\mathcal{C}^{\alpha}$}-regularity for a class of non-diagonal elliptic systems with {$p$}-growth, Calc. Var. Partial Differential Equations, Vol. 43, No. 3, pp. 441--462, 2012. [DOI:10.1007/s00526-011-0417-8] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr; Málek, Josef and Świerczewska-Gwiazda, Agnieszka: On Unsteady Flows of Implicitly Constituted Incompressible Fluids, SIAM J. Math. Anal., Vol. 44, No. 4, pp. 2756--2801, 2012. [DOI:10.1137/110830289] [Published] [bibtex] [ris]
Chapter Bulíček, Miroslav; Gwiazda, Piotr; Málek, Josef; Świerczewska-Gwiazda, Agnieszka and Rajagopal, K. R.: On flows of fluids described by an implicit constitutive equation characterized by a maximal monotone graph, in: Mathematical Aspects of Fluid Mechanics, pages 23--51, Cambridge University Press, 2012. [URL:http://www.cambridge.org/aus/c...] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Rajagopal, K. R.: On Kelvin-Voigt model and its generalizations, Evolution Equations and Control Theory, Vol. 1, No. 1, pp. 17-42, 2012. [DOI:10.3934/eect.2012.1.17] [Published] [bibtex] [ris]
Article Česenek, Jan and Feistauer, Miloslav: Theory of the space-time discontinuous Galerkin method for nonstationary parabolic problems with nonlinear convection and diffusion, SIAM J. Numer. Anal., 2012. [URL:http://www.karlin.mff.cuni.cz/...] [Accepted] [bibtex] [ris]
Article Česenek, Jan and Feistauer, Miloslav: DGFEM for the analysis of airfoil vibrations induced by compressible flow, ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik, 2012. [Submitted] [bibtex] [ris]
Article Feireisl, Eduard; Mucha, Piotr B; Novotný, Antonín and Pokorný, Milan: Time-Periodic solutions to the full Navier–Stokes–Fourier system, Archive for Rational Mechanics and Analysis, Vol. 204, No. 3, pp. 745–786, 2012. [DOI:10.1007/s00205-012-0492-9] [Published] [bibtex] [ris]
Article Gogatishvili, Amiran; Pick, Luboš and Schneider, Jan: Characterization of a rearrangement-invariant hull of a Besov space via interpolation, Rev. Mat. Complutense, Vol. 25, No. 1, pp. 267-283, 2012. [Published] [bibtex] [ris]
Article Haslinger, Jaroslav; Janovský, Vladimír and Ligurský, Tomáš: Qualitative analysis of solutions to discrete static contact problems with Coulomb friction, Computer Methods in Applied Mechanics and Engineering, Vol. 205-208, pp. 149-161, 2012. [DOI:10.1016/j.cma.2010.09.010] [Published] [bibtex] [ris]
Article Heida, Martin; Málek, Josef and Rajagopal, K. R.: On the development and generalizations of Cahn-Hilliard equations within a thermodynamic framework, ZAMP - Zeitschrift für Angewandte Mathematik und Physik, Vol. 63, No. 1, pp. 145-169, 2012. [DOI:10.1007/s00033-011-0139-y] [Published] [bibtex] [ris]
Article Heida, Martin; Málek, Josef and Rajagopal, K. R.: On the Development and Generalizations of Allen-Cahn and Stefan Equations within a Thermodynamic Framework, ZAMP - Zeitschrift für Angewandte Mathematik und Physik, pp. 1--18, 2012. [DOI:10.1007/s00033-011-0189-1] [Published] [bibtex] [ris]
Article Hirn, Adrian; Lanzendörfer, Martin and Stebel, Jan: Finite element approximation of flow of fluids with shear rate and pressure dependent viscosity, IMA Journal of Numerical Analysis, Vol. 32, No. 4, pp. 1604--1634, 2012. [DOI:10.1093/imanum/drr033] [Published] [bibtex] [ris]
Chapter Hoang, H. D.; Beneš, Michal and Suzuki, A: Phase-field approach to crystal growth, in: COE Lecture Note, pages 18-25, Faculty of Mathematics, Kyushu University Fukuoka, 2012. [Accepted] [bibtex] [ris]
Article Hron, Jaroslav; Kratochvíl, Jan; Málek, Josef; Rajagopal, K. R. and Tůma, Karel: A Thermodynamically Compatible Rate Type Fluid to Describe the Response of Asphalt, Mathematics and Computers in Simulation, Vol. 82, No. 10, pp. 1853--1873, 2012. [DOI:10.1016/j.matcom.2011.03.010] [Published] [bibtex] [ris]
Article Kaplický, Petr and Tichý, Jakub: Boundary Regularity of Flows under Perfect Slip Boundary Conditions [bibtex] [ris]
Article Kleprlík, Luděk: Mappings of finite signed distortion: Sobolev spaces and composition of mappings [DOI:10.1016/j.jmaa.2011.08.045] [bibtex] [ris]
Article Krbec, Miroslav and Schmeisser, Hans Jurgen: On dimension-free imbeddings II, Revista Matemática Complutense, Vol. 25, pp. 247-265, 2012. [DOI:10.1007/s13163-011-0068-5] [Published] [bibtex] [ris]
Article Kubica, Adam; Pokorný, Milan and Zajaczkowski, Wojciech: Remarks on regularity criteria for axially symmetric weak solutions to the Navier–Stokes equations, Mathematical Methods in the Applied Sciences, Vol. 35, No. 3, pp. 360--371, 2012. [DOI:10.1002/mma.1586] [Published] [bibtex] [ris]
Article Ligurský, Tomáš: Theoretical analysis of discrete contact problems with Coulomb friction, Applications of Mathematics, No. 3, 2012. [URL:http://www.karlin.mff.cuni.cz/...] [Accepted] [bibtex] [ris]
Chapter Loucký, J and Oberhuber, Tomáš: Graph Cuts in Segmentation of Left Ventricle from MRI Data, in: COE Lecture Note, pages 46-54, Faculty of Mathematics, Kyushu University Fukuoka, 2012. [Accepted] [bibtex] [ris]
Article Medkova, Dagmar; Kračmar, Stanislav; Nečasová, Šárka and Varnhorn, Werner: A Maximum Modulus Theorem for the Oseen Problem, Annali di Matematica Pura ed Applicata, 2012. [DOI:10.1007/s10231-012-0258-x] [Published] [bibtex] [ris]
Article Mielke, Alexander; Roubíček, Tomáš and Thomas, M.: From damage to delamination in nonlinearly elastic materials at small strains, Journal of Elasticity, 2012. [Accepted] [bibtex] [ris]
Article Naumann, Joachim; Pokorný, Milan and Wolf, Joerg: On the existence of weak solutions to the equations of steady flow of heat-conducting fluids with dissipative heating, Nonlinear Analysis: Real World Applications, Vol. 13, No. 4, pp. 1600--1620, 2012. [DOI:10.1016/j.nonrwa.2011.11.018] [Published] [bibtex] [ris]
Chapter Pauš, P. and Beneš, Michal: Dislocation-Precipitate Interaction In Discrete Dislocation Dynamics, in: COE Lecture Note, pages 55-62, Faculty of Mathematics, Kyushu University Fukuoka, 2012. [Published] [bibtex] [ris]
Article Petzeltová, Hana; Rocca, Elisabetta and Schimperna, Giulio: On the long-time behavior of some mathematical models for nematic liquid crystals, Calc. Var. Partial Differential Equations, 2012. [DOI:10.1007/s00526-012-0496-1] [Published] [bibtex] [ris]
Article Průša, Vít and Rajagopal, K. R.: Flow of an electrorheological fluid between eccentric rotating cylinders, Theoretical and Computational Fluid Dynamics, Vol. 26, No. 1-4, pp. 1-21, 2012. [DOI:10.1007/s00162-011-0224-z] [Published] [bibtex] [ris]
Chapter Roubíček, Tomáš; Kružík, Martin and Zeman, Jan: Delamination and adhesive contact models and their mathematical analysis and numerical treatment, in: Math. Methods and Models in Composites, Imperial College Press, 2012. [URL:http://www.karlin.mff.cuni.cz/...] [Accepted] [bibtex] [ris]
Article Roubíček, Tomáš and Thomassetti, G.: Phase transformations in electrically conductive ferromagnetic shape-memory alloys, their thermodynamics and analysis, Archive for Rational Mechanics and Analysis, 2012. [Submitted] [bibtex] [ris]
Chapter Strachota, Pavel; Beneš, Michal and Grottadaurea, M.: Computational Investigation and Assessment of Numerical Schemes for Anisotropic Diffusion Equations, in: COE Lecture Note, pages 73-83, Faculty of Mathematics, Kyushu University Fukuoka, 2012. [Published] [bibtex] [ris]
2011
Article Bartels, Sören and Roubíček, Tomáš: Thermo-visco-elasticity with rate-independent plasticity in isotropic materials undergoing thermal expansion [DOI:10.1051/m2an/2010063] [bibtex] [ris]
Article Beneš, Michal; Chabiniok, R. and Tintěra, J.: Segmentation of MRI data by means of nonlinear diffusion, Kybernetika, 2011. [Submitted] [bibtex] [ris]
Beneš, Michal; Oberhuber, Tomáš; Strachota, Pavel; Straka, Robert and Havlena, V.: Mathematical modelling of combustion and biofuel co-firing in industrial steam generators, in: RIMS proceedings "Bessatsu Kokyuroku", Kyoto, Japan, 2011. [Submitted] [bibtex] [ris]
Article Beneš, Michal; Yazaki, Shigetoshi and Kimura, M.: Computational studies of non-local anisotropic Allen-Cahn equation, Mathematica Bohemica, Vol. 136, No. 4, pp. 429-437, 2011. [Published] [bibtex] [ris]
Article Benešová, Barbora: Global optimization numerical strategies for rate-independent processes, J. of Global Optimization, Vol. 50, No. 2, pp. 197--220, 2011. [DOI:10.1007/s10898-010-9560-6] [Published] [bibtex] [ris]
Article Benešová, Barbora: A thermodynamically consistent model of shape-memory alloys [DOI:10.1002/pamm.201110169] [bibtex] [ris]
Article Benešová, Barbora; Kružík, Martin and Pathó, Gabriel: Young measures supported on regular matrices, Annales de l'Institut Henri Poincaré (C) Analyse Non Linéaire, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Submitted] [bibtex] [ris]
Article Bulíček, Miroslav; Consiglieri, Luisa and Málek, Josef: On solvability of a non-linear heat equation with a non-integrable convective term and data involving measures, Nonlinear Analysis: Real World Applications, Vol. 12, No. 1, pp. 571--591, 2011. [DOI:10.1016/j.nonrwa.2010.07.001] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Frehse, Jens: On nonlinear elliptic Bellman systems for a class of stochastic differential games in arbitrary dimension, Mathematical Models and Methods in Applied Sciences, Vol. 21, No. 1, pp. 215--240, 2011. [DOI:10.1142/S0218202511005027] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr; Málek, Josef and Świerczewska-Gwiazda, Agnieszka: On scalar hyperbolic laws with discontinuous flux, Mathematical Models and Methods in Applied Sciences, Vol. 21, No. 1, pp. 89--113, 2011. [DOI:10.1142/S021820251100499X] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Kaplický, Petr and Málek, Josef: An $L^2$-maximal regularity result for the evolutionary Stokes-Fourier system, Applicable Analysis, Vol. 90, No. 1, pp. 31--45, 2011. [DOI:10.1080/00036811003735931] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Lewandowski, Roger and Málek, Josef: On evolutionary Navier-Stokes-Fourier type systems in three spatial dimensions, Comment. Math. Univ. Carolin., Vol. 52, No. 1, pp. 89--114, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Rajagopal, K. R.: On The Need For Compatibility Of Thermal And Mechanical Data In Flow Problems, International Journal of Engineering Science, Vol. 49, No. 7, pp. 537--543, 2011. [DOI:10.1016/j.ijengsci.2011.01.008] [Published] [bibtex] [ris]
Bulíček, Miroslav; Málek, Josef and Terasawa, Yutaka: On Hausdorff Dimension of Blow-Up Times Relevant to Weak Solution of Generalized Navier-Stokes Fluids [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Bulíček, Miroslav and Ulrych, Oldřich: Planar flows of incompressible heat-conducting shear-thinning fluids- Existence analysis, Applications of Mathematics, Vol. 56, No. 1, pp. 7--38, 2011. [DOI:10.1007/s10492-011-0007-2] [Published] [bibtex] [ris]
Česenek, Jan and Feistauer, Miloslav: Theory of the Space-Time Discontinuous Galerkin Method for Nonstationary Parabolic Problems with Nonlinear Convection and Diffusion, in: Numerical Methods an Applications, 7th International Conference NMA2010, Borovets, Bulgaria, pages 1-13, Springer, Heidelberg, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Ducomet, Bernard; Nečasová, Šárka and Vasseur, Alexis: On spherically symmetric motions of a viscous compressible barotropic and selfgravitating gas [DOI:10.1007/s00021-009-0010-5] [bibtex] [ris]
Article Edmunds, David; Hudzik, Henrik and Krbec, Miroslav: On weighted critical imbeddings of Sobolev spaces, Matematische Zeitschrift, Vol. 268, No. 1-2, pp. 585-592, 2011. [DOI:10.1007/s00209-010-0684-7] [Published] [bibtex] [ris]
Article Farwig, Reinhard; Nečasová, Šárka and Neustupa, Jiří: Spectral Analysis of a Stokes Type Operator Arising from Flow around a Rotating Body, J. of Math. Soc. of Japan, Vol. 63, No. 1, pp. 163-194, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Neustupa, Jiří and Stebel, Jan: Convergence of a Brinkman-type penalization for compressible fluid flows [DOI:10.1016/j.jde.2010.09.031] [bibtex] [ris]
Article Freddi, L.; Paroni, R.; Roubíček, Tomáš and Zanini, C.: Quasistatic delamination models for Kirchhoff-Love plates, ZAMM - Journal of Applied Mathematics and Mechanics / Zeitschrift für Angewandte Mathematik und Mechanik, Vol. 91, No. 11, pp. 845--865, 2011. [DOI:10.1002/zamm.201000171] [Published] [bibtex] [ris]
Article Haslinger, Jaroslav; Kučera, Radek and Ligurský, Tomáš: Qualitative analysis of 3D elastostatic contact problems with orthotropic Coulomb friction and solution-dependent coefficients of friction, Journal of Computational and Applied Mathematics, Vol. 235, No. 12, pp. 3464 - 3480, 2011. [DOI:10.1016/j.cam.2011.02.007] [Published] [bibtex] [ris]
Article Haslinger, Jaroslav and Stebel, Jan: Shape optimization for Navier-Stokes equations with algebraic turbulence model: Numerical analysis and computation [DOI:10.1007/s00245-010-9121-x] [bibtex] [ris]
Article Havrda, Jaroslav: Incompressible mixtures with thermal diffusion cross effects, Applications of Mathematics, 2011. [URL:http://ncmm.karlin.mff.cuni.cz...] [Submitted] [bibtex] [ris]
Article Hlaváčová, Nikola: On the domain dependence of solutions to the compressible Navier-Stokes equations of an isothermal fluid, Acta Aplicandae Mathematicae, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Accepted] [bibtex] [ris]
Chapter Hoang, H. D.: Phase-Field Modelling of Heteroepitaxial Growth, in: Sborník workshopu doktorandů FJFI oboru Matematické inženýrství, KM FJFI ČVUT, Praha, 2011. [Published] [bibtex] [ris]
Hoang, H. D. and Beneš, Michal: Numerical Simulation of Anisotropic Surface Diffusion of Graphs, in: RIMS proceedings "Bessatsu Kokyuroku", Kyoto, Japan, 2011. [Submitted] [bibtex] [ris]
Article Hron, Jaroslav; Málek, Josef; Průša, Vít and Rajagopal, K. R.: Further remarks on simple flows of fluids with pressure dependent viscosities [DOI:10.1016/j.nonrwa.2010.06.025] [bibtex] [ris]
Article Karra, Satish; Průša, Vít and Rajagopal, K. R.: On Maxwell fluid with relaxation time and viscosity depending on the pressure [DOI:10.1016/j.ijnonlinmec.2011.02.013] [bibtex] [ris]
Article Kerman, Ron and Pick, Luboš: Explicit formulas for optimal rearrangement-invariant norms in Sobolev imbedding inequalities, Studia Math., Vol. 26, No. 2, pp. 97--119, 2011. [Published] [bibtex] [ris]
Article Klement, V.; Oberhuber, Tomáš and Ševčovič, Daniel: Constrained Level Set Method and its Application to Image Segmentation, Applied Mathematics and Computation, 2011. [Submitted] [bibtex] [ris]
Article Konieczny, Pawel and Kreml, Ondřej: On the 3D steady flow of a second grade fluid past an obstacle, J. Math. Fluid Mech., 2011. [DOI:10.1007/s00021-011-0057-y] [Published] [bibtex] [ris]
Krbec, Miroslav and Schmeisser, Hans Jurgen: Dimension-invariant Sobolev imbeddings, in: Function Spaces IX., Warszawa, pages 205-217, Polish Academy of Sciences, 2011. [Published] [bibtex] [ris]
Article Kukučka, Peter: Singular Limits of the Equations of Magnetohydrodynamics, Journal of Mathematical Fluid Mechanics, Vol. 13, No. 2, pp. 173-189, 2011. [DOI:10.1007/s00021-009-0007-0] [Published] [bibtex] [ris]
Article Lanzendörfer, Martin and Stebel, Jan: On Pressure Boundary Conditions for Steady Flows of Incompressible Fluids with Pressure and Shear Rate Dependent Viscosities, Applications of Mathematics, Vol. 56, No. 3, pp. 265--285, 2011. [DOI:10.1007/s10492-011-0016-1] [Published] [bibtex] [ris]
Article Ligurský, Tomáš and Renard, Yves: A Well-Posed Semi-Discretization of Elastodynamic Contact Problems with Friction, Quarterly Journal of Mechanics and Applied Mathematics, Vol. 64, pp. 215-238, 2011. [DOI:10.1093/qjmam/hbr004] [Published] [bibtex] [ris]
Article Lukeš, Jaroslav; Pick, Luboš and Pokorný, Dušan: ON GEOMETRIC PROPERTIES OF THE SPACES $L^{p(x)}$, Revista Matemática Complutense, Vol. 24, No. 1, pp. 115--130, 2011. [DOI:10.1007/s13163-010-0032-9] [Published] [bibtex] [ris]
Article Máca, R; Beneš, Michal and Tintěra, J.: Application of a degenerate diffusion method in medical image processing, Journal of Math for Industry, pp. 33-40, 2011. [Published] [bibtex] [ris]
Article Mach, J.: Application of the nonlinear Galerkin FEM method to the solution of the reaction diffusion equations, Journal of Math for Industry, pp. 41-52, 2011. [Accepted] [bibtex] [ris]
Article Mach, J.: Application of the nonlinear Galerkin FEM method to the solution of the reaction diffusion equations, Journal of Math for Industry, Vol. 3, pp. 41-51, 2011. [Published] [bibtex] [ris]
Article Mácha, Václav: On a generalized Stokes problem, Cent. Eur. J. Math., Vol. 9, No. 4, pp. 874--887, 2011. [DOI:10.2478/s11533-011-0047-6] [Published] [bibtex] [ris]
Article Muzereau, Olivier; Neustupa, Jiří and Penel, Patrick: A weak solvability to the steady Navier-Stokes equations for compressible barotropic fluid with generalized impermeability boundary conditions, Applicable Analysis: An International Journal, Vol. 90, No. 1, pp. 141-157, 2011. [DOI:10.1080/00036811003738828] [Published] [bibtex] [ris]
Article Nečasová, Šárka; Lukáčová-Medviďová, Mária and Hundertmark-Zaušková, Anna: On the existence of weak solution to the coupled fluid-structure interaction problem for non-Newtonian shear-dependent fluid, Quarterly of Applied Mathematics, 2011. [Submitted] [bibtex] [ris]
Article Nečasová, Šárka and Schumacher, Katrin: Strong solutions to the Stokes-Equations of a flow around a rotating body in weighted $L^q$ spaces, Mathematische Nachrichten, Vol. 284, No. 13, pp. 1701 – 1714, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Novotný, Antonín and Pokorný, Milan: Weak and variational solutions to steady equations for compressible heat conducting fluids, SIAM J. Math. Anal., Vol. 43, No. 3, pp. 1158--1188, 2011. [DOI:10.1137/100799393] [Published] [bibtex] [ris]
Article Novotný, Antonín and Pokorný, Milan: Weak solutions for steady compressible Navier--Stokes--Fourier system in two space dimensions, Applications of Mathematics, Vol. 56, No. 1, pp. 137--160, 2011. [DOI:10.1007/s10492-011-0013-4] [Published] [bibtex] [ris]
Article Novotný, Antonín and Pokorný, Milan: Steady compressible Navier--Stokes--Fourier system for monoatomic gas and its generalizations, Journal of Differential Equations, Vol. 251, No. 2, pp. 270--315, 2011. [DOI:10.1016/j.jde.2011.04.008] [Published] [bibtex] [ris]
Article Oberhuber, Tomáš: Numerical Solution for the Anisotropic Willmore Flow of Graphs, Computer Aided Geometric Design, 2011. [Submitted] [bibtex] [ris]
Article Oberhuber, Tomáš; Suzuki, A and Vacata, J.: New Row-grouped CSR Format for Storing the Sparse Matrices on GPU with Implementation in CUDA, Acta Technica, 2011. [Accepted] [bibtex] [ris]
Article Oberhuber, Tomáš; Suzuki, A and Žabka, V: The CUDA implementation of the method of lines for the curvature dependent flows, Kybernetika, Vol. 45, No. 2, pp. 251-272, 2011. [Published] [bibtex] [ris]
Pauš, P.; Beneš, Michal and Kratochvíl, Jan: Simulation of dislocation cross-slip, in: Proceedings of RIMS seminar, Kyoto, Japan, 2011. [Submitted] [bibtex] [ris]
Article Pauš, P.; Beneš, Michal and Kratochvíl, Jan: Simulation of dislocation annihilation by cross-slip, Acta Physica Polonica, 2011. [Accepted] [bibtex] [ris]
Article Pavlíček, Libor: Monotonically controlled mappings [DOI:10.4153/CJM-2011-004-0] [bibtex] [ris]
Article Penel, Patrick and Pokorný, Milan: On anisotropic regularity criteria for the solutions to 3D Navier--Stokes equations, J. Math. Fluid Mech., Vol. 13, No. 3, pp. 341--353, 2011. [DOI:10.1007/s00021-010-0038-6] [Published] [bibtex] [ris]
Article Pernecká, Eva and Pick, Luboš: Compactness of Hardy operators involving suprema [bibtex] [ris]
Article Pokorný, Milan: On the steady solutions to a model of compressible heat conducting fluid in two space dimensions, J. Part. Diff. Eq., Vol. 24, No. 4, pp. 334--350, 2011. [URL:http://ncmm.karlin.mff.cuni.cz...] [Published] [bibtex] [ris]
Article Průša, Vít and Rajagopal, K. R.: Jump Conditions in Stress Relaxation and Creep Experiments of Burgers Type Fluids-A Study in the Application of Colombeau Algebra of Generalized Functions [DOI:10.1007/s00033-010-0109-9] [bibtex] [ris]
Article Průša, Vít and Rajagopal, K. R.: A note on the decay of vortices in a viscous fluid [DOI:10.1007/s11012-010-9347-3] [bibtex] [ris]
Article Rossi, R. and Roubíček, Tomáš: Thermodynamics and analysis of rate-independent adhesive contact at small strains, Nonlinear Analysis: Theory, Methods & Applications, Vol. 74, pp. 3159-3190, 2011. [DOI:10.1016/j.na.2011.01.031] [Published] [bibtex] [ris]
Article Roubíček, Tomáš: Thermodynamics of perfect plasticity, Discrete and Continuous Dynamical Systems - Series S, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Accepted] [bibtex] [ris]
Article Roubíček, Tomáš: On certain convex compactifications for relaxation in evolution problems [DOI:10.3934/dcdss.2011.4.467] [bibtex] [ris]
Article Roubíček, Tomáš: Approximation in multiscale modelling of microstructure evolution in shape-memory alloys, Continuum Mechanics and Thermodynamics, Vol. 23, pp. 491--507, 2011. [DOI:10.1007/s00161-011-0190-0] [Published] [bibtex] [ris]
Article Roubíček, Tomáš; Mantič, Vladislav and Panagiotopoulos, Christos G.: A quasistatic mixed-mode delamination model, Discrete and Continuous Dynamical Systems - Series S, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Accepted] [bibtex] [ris]
Article Roubíček, Tomáš and Tomassetti, Giuseppe: Ferromagnets with eddy currents and pinning effects: their thermodynamics and analysis, Mathematical Models and Methods in Applied Sciences, Vol. 21, No. 1, pp. 29-55, 2011. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Schimperna, Giulio; Rocca, Elisabetta and Feireisl, Eduard: On a non-isothermal model for nematic liquid crystals, Nonlinearity, Vol. 24, No. 1, pp. 243-257, 2011. [DOI:10.1088/0951-7715/24/1/012] [Published] [bibtex] [ris]
Article Stebel, Jan: On shape stability of incompressible fluids subject to Navier's slip, J. Math. Fluid Mech., Vol. Online first, 2011. [DOI:10.1007/s00021-011-0086-6] [Accepted] [bibtex] [ris]
Article Strachota, Pavel and Beneš, Michal: Towards Clinical Applicability of the Diffusion-based DT-MRI Visualization Algorithm, Journal of Visual Communication and Image Representation, 2011. [Accepted] [bibtex] [ris]
Straka, Robert: Computational Model of Pulverized Coal Combustion and Nitric Oxide Production, Czech Technical University in Prague, 2011. [Published] [bibtex] [ris]
Article Straka, Robert; Makovička, Jindřich and Beneš, Michal: Numerical simulation of NO production in pulverized coal fired furnace, Environment Protection Engineering, Vol. 37, No. 2, pp. 13-22, 2011. [Published] [bibtex] [ris]
Article Vlasák, Miloslav; Dolejší, Vít and Hájek, J.: A priori error estimates of an extrapolated space-time discontinuous galerkin method for nonlinear convection-diffusion problems, Numerical Methods for Partial Differential Equations, Vol. 27, No. 6, pp. 1456--1482, 2011. [DOI:10.1002/num.20591] [Published] [bibtex] [ris]
2010
Article Ambrož, P.; Masáková, Z. and Pelantová, E.: Morphisms fixing words associated with exchange of three intervals, RAIRO-Theor. Inf. Appl., Vol. 44, pp. 3-17, 2010. [DOI:10.1051/ita/2010002] [Published] [bibtex] [ris]
Article Bárta, Tomáš: Two notes on eventually differentiable families of operators [bibtex] [ris]
Bauer, P.: Flow over a rough surface, in: Proceedings of SNA10, Nové Hrady, 2010, pages 13-16, 2010. [URL:http://www.cs.cas.cz/sna10/sbo...] [Published] [bibtex] [ris]
Bauer, P.; Suzuki, A and Jaňour, Z.: FEM for Flow and Pollution Transport in a Street Canyon., in: Numerical Mathematics and Advanced Applications 2009, Proceedings of ENUMATH 2009, the 8th European Conference on Numerical Mathematics and Advanced Applications, Uppsala, Sweden, pages 115-123, 2010. [URL:http://www.springerlink.com/co...] [Published] [bibtex] [ris]
Article Bellout, Hamid; Neustupa, Jiří and Penel, Patrick: On a {$\nu$}-continuous family of strong solutions to the {E}uler or {N}avier-{S}tokes equations with the {N}avier-type boundary condition [DOI:10.3934/dcds.2010.27.1353] [bibtex] [ris]
Article Březina, Jan: Asymptotic properties of solutions to the equations of incompressible fluid mechanics, Journal of Mathematical Fluid Mechanics, Vol. 12, No. 4, pp. 536-553, 2010. [DOI:10.1007/s00021-009-0301-x] [Published] [bibtex] [ris]
Article Bucur, Dorin; Feireisl, Eduard and Nečasová, Šárka: Boundary behavior of viscous fluids: Influence of wall roughness and friction-driven boundary conditions [DOI:10.1007/s00205-009-0268-z] [bibtex] [ris]
Article Bulíček, Miroslav; Ettwein, Frank; Kaplický, Petr and Pražák, Dalibor: On uniqueness and time regularity of flows of power-law like non-Newtonian fluids [DOI:10.1002/mma.1314] [bibtex] [ris]
Article Bulíček, Miroslav; Feireisl, Eduard; Málek, Josef and Shvydkoy, Roman: On the motion of incompressible inhomogeneous Euler-Korteweg fluids, Discrete and Continuous Dynamical Systems - Series S, Vol. 3, No. 3, pp. 497-515, 2010. [DOI:10.3934/dcdss.2010.3.497] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Majdoub, Mohamed and Málek, Josef: Unsteady flows of fluids with pressure dependent viscosity in unbounded domains, Nonlinear Analysis: Real World Applications, Vol. 11, No. 5, pp. 3968-3983, 2010. [DOI:10.1016/j.nonrwa.2010.03.004] [Published] [bibtex] [ris]
Česenek, Jan and Feistauer, Miloslav: Numerical solution of interaction of compressible flow and a vibrating airfoil [bibtex] [ris]
Article Cianchi, Andrea and Pick, Luboš: An optimal endpoint trace embedding [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Consiglieri, Luisa; Nečasová, Šárka and Sokolowski, Jan: New approach to the incompressible Maxwell-Boussinesq approximation: Existence, uniqueness and shape sensitivity [DOI:10.1016/j.jde.2010.09.029] [bibtex] [ris]
Article Damanik, H.; Hron, Jaroslav; Ouazzi, A. and Turek, Stefan: A monolithic FEM approach for the log-conformation reformulation (LCR) of viscoelastic flow problems, Journal of Non-Newtonian Fluid Mechanics, Vol. 165, No. 19, pp. 1105-1113, 2010. [DOI:10.1016/j.jnnfm.2010.05.008] [Published] [bibtex] [ris]
Article Deuring, Paul and Neustupa, Jiří: An eigenvalue criterion for stability of a steady {N}avier-{S}tokes flow in {$\Bbb R^3$} [DOI:10.1007/s00021-008-0283-0] [bibtex] [ris]
Article Donatelli, Donatella; Feireisl, Eduard and Novotný, Antonín: On incompressible limits for the Navier-Stokes system on unbounded domains under slip boundary conditions , Discrete and Continuous Dynamical Systems - Series B, Vol. 13, No. 4, pp. 783 - 798, 2010. [DOI:10.3934/dcdsb.2010.13.783] [Published] [bibtex] [ris]
Article Drábek, Pavel; Namlyeyeva, Yuliya and Nečasová, Šárka: Convergence of variational eigenvalues and eigenfunctions to the Dirichlet problem for the p-Laplacian in domains with fine-grained boundary, Proceedings of the Royal Society of Edinburgh. Section A. Mathematics, Vol. 140, No. 3, pp. 573--596, 2010. [DOI:10.1017/S0308210507001035] [Published] [bibtex] [ris]
Article Ducomet, Bernard; Nečasová, Šárka and Vasseur, Alexis: On global motions of a compressible barotropic and selfgravitating gas with density-dependent viscosities [DOI:10.1007/s00033-009-0035-x] [bibtex] [ris]
Article Farwig, Reinhard and Neustupa, Jiří: Spectral properties in {$L^q$} of an {O}seen operator modelling fluid flow past a rotating body [DOI:10.2748/tmj/1277298650] [bibtex] [ris]
Article Feireisl, Eduard; Novotný, Antonín and Petzeltová, Hana: Low Mach number limit for the Navier-Stokes system on unbounded domains under strong stratification [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Feireisl, Eduard; Novotný, Antonín and Sun, Yongzhong: Suitable weak solutions to the Navier-Stokes equations of compressible viscous fluids [bibtex] [ris]
Article Feireisl, Eduard; Novotný, Antonín and Takahashi, Takeo: Homogenization and singular limits for the complete Navier-Stokes-Fourier system, Journal de Mathématiques Pures et Appliquées, Vol. 94, pp. 33-57, 2010. [DOI:10.1016/j.matpur.2009.11.006] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Petzeltová, Hana; Rocca, Elisabetta and Schimperna, Giulio: Analysis of a phase-field model for two-phase compressible fluids, Mathematical Models and Methods in Applied Sciences, Vol. 20, No. 7, pp. 1129-1160, 2010. [DOI:10.1142/S0218202510004544] [Published] [bibtex] [ris]
Article Feistauer, Miloslav; Kučera, Václav and Prokopová, Jaroslava: Discontinuous Galerkin Solution of Compressible Flow in Time Dependent Domains [DOI:10.1016/j.matcom.2009.01.020] [bibtex] [ris]
Article Foralewski, P; Hudzik, Henrik; Kaczmarek, R and Krbec, Miroslav: Moduli and characteristics of monotonicity in some Banach lattices, Fixed point theory and applications, Vol. 2010, No. 852346, 2010. [DOI:10.1155/2010/852346] [Published] [bibtex] [ris]
Article Frehse, Jens; Málek, Josef and Růžička, Michael: Large Data Existence Result for Unsteady Flows of Inhomogeneous Shear-Thickening Heat-Conducting Incompressible Fluids [DOI:10.1080/03605300903380746] [bibtex] [ris]
Article Guidugli, P; Roubíček, Tomáš and Tomassetti, Giuseppe: A thermodynamically-consistent theory of the ferro/paramagnetic transition [DOI:10.1007/s00205-010-0349-z] [bibtex] [ris]
Article Heida, Martin and Málek, Josef: On compressible Korteweg fluid-like materials [DOI:10.1016/j.ijengsci.2010.06.031] [bibtex] [ris]
Article Hron, Jaroslav; Málek, Josef; Pustějovská, Petra and Rajagopal, K. R.: On the Modelling of the Synovial Fluid [DOI:10.1155/2010/104957] [bibtex] [ris]
Article Hron, Jaroslav; Neuss-Radu, Maria and Pustějovská, Petra: Mathematical modeling and simulation of flow in domains separated by leaky semipermeable membrane including osmotic effect, Applications of Mathematics, Vol. 56, No. 1, pp. 51--68, 2010. [DOI:10.1007/s10492-011-0009-0] [Published] [bibtex] [ris]
Illangasekare, Tissa H.; Frippiar, C. C. and Fučík, Radek: Dispersion and Mass Transfer Coefficients in Groundwater of Near-surface Geologic Formations, chapter 15, CRC Press/Taylor and Francis Group, 2010. [URL:http://www.crcpress.com/produc...] [Published] [bibtex] [ris]
Krbec, Miroslav and Schmeisser, Hans Jurgen: Dimension-free imbeddings of Sobolev spaces [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Kreml, Ondřej and Pokorný, Milan: On the local strong solutions for the FENE dumbbell model, Discrete and Continuous Dynamical Systems - Series S, Vol. 3, pp. 311-324, 2010. [DOI:10.3934/dcdss.2010.3.311] [Published] [bibtex] [ris]
Article Křišťan, Josef and Kratochvíl, Jan: Bowing out of Dislocations from Walls of Persistent Slip Band [DOI:10.3139/146.110327] [bibtex] [ris]
Article Kučera, Václav: Optimal {$L^\infty (L^2)$-error} estimates for the DG method applied to nonlinear convection-diffusion problems with nonlinear diffusion, Numerical Functional Analysis and Optimization, Vol. 31, No. 1-3, pp. 285-312, 2010. [Published] [bibtex] [ris]
Article Kulvait, Vojtěch; Málek, Josef and Rajagopal, K. R.: Stress concentration due to an elliptic hole in a degrading linearized elastic solid [bibtex] [ris]
Mach, J.: Quantitative analysis of numerical solution for the Gray-Scott model, in: Proceedings of SNA10, Nové Hrady, pages 110-113, Institute of Computer Science AS CR, 2010. [URL:http://www.cs.cas.cz/sna10/sbo...] [Published] [bibtex] [ris]
Article Málek, Josef; Průša, Vít and Rajagopal, K. R.: Generalizations of the Navier--Stokes fluid from a new perspective [DOI:10.1016/j.ijengsci.2010.06.013] [bibtex] [ris]
Article Málek, Josef and Rajagopal, K. R.: Compressible Generalized Newtonian Fluids [DOI:10.1007/s00033-010-0061-8] [bibtex] [ris]
Article Meziat, Rene; Roubíček, Tomáš and Patiño, Diego: Coarse-convex-compactification approach to numerical solution of nonconvex variational problems [DOI:10.1080/01630560903574985] [bibtex] [ris]
Article Mielke, Alexander; Roubíček, Tomáš and Zeman, Jan: Complete damage in elastic and viscoelastic media and its energetics [DOI:10.1016/j.cma.2009.09.020] [bibtex] [ris]
Article Minárik, Vojtěch; Beneš, Michal and Kratochvíl, Jan: Simulation of Dynamical Interaction between Dislocations and Dipolar Loops, Journal of Applied Physics, Vol. 061802, No. 107, 2010. [DOI:10.1063/1.3340518] [Published] [bibtex] [ris]
Article Mucha, Piotr B and Pokorný, Milan: Weak solutions to equations of steady compressible heat conducting fluids [DOI:10.1142/S0218202510004441] [bibtex] [ris]
Article Muzereau, Olivier; Neustupa, Jiří and Penel, Patrick: A steady Navier-Stokes model for compressible fluid with partially strong solutions [DOI:10.1016/j.crma.2010.04.001] [bibtex] [ris]
Article Muzereau, Olivier; Neustupa, Jiří and Penel, Patrick: A partially strong solution to the steady Navier–Stokes equations for compressible barotropic fluid with generalized impermeability boundary conditions [URL:http://stacks.iop.org/0951-771...] [bibtex] [ris]
Article Nekvinda, Aleš and Pick, Luboš: Optimal estimates for the Hardy averaging operator [DOI:10.1002/mana.200711155] [bibtex] [ris]
Chapter Neustupa, Jiří and Penel, Patrick: A weak solvability of the Navier-Stokes equation with Navier's boundary condition around a ball striking the wall [DOI:10.1007/978-3-642-04068-9_24] [bibtex] [ris]
Article Neustupa, Jiří and Penel, Patrick: Local in time strong solvability of the non-steady Navier-Stokes equations with Navier's boundary condition and the question of the inviscid limit [DOI:doi: 10.1016/j.crma.2010.09.021] [bibtex] [ris]
Oberhuber, Tomáš; Suzuki, A and Vacata, J.: New Row-grouped CSR Format for Storing the Sparse Matrices on GPU with Implementation in CUDA. [bibtex] [ris]
Pauš, P. and Beneš, Michal: Discrete Dislocation Dynamics and Mean Curvature Flow [URL:http://www.springerlink.com/co...] [bibtex] [ris]
Pauš, P.; Beneš, Michal and Kratochvíl, Jan: Model of Topological Changes in Discrete Dislocation Dynamics, in: Proceedings of MMM 2010, Multiscale Materials Modeling, Freiburg, pages 721-728, 2010. [Published] [bibtex] [ris]
Article Pokorný, Milan and Pecharová, Petra: Steady compressible Navier-Stokes-Fourier system in two space dimensions, Comment. Math. Univ. Carolin., Vol. 51, No. 4, pp. 453--479, 2010. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Průša, Vít: Revisiting Stokes first and second problems for fluids with pressure dependent viscosities [DOI:10.1016/j.ijengsci.2010.04.009] [bibtex] [ris]
Roche, Thomas and Krejčí, Pavel: Lipschitz Continuous Data Dependence of Sweeping Processes in BV [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Roubíček, Tomáš: Thermodynamics of rate-independent processes in viscous solids at small strains [DOI:10.1137/080729992] [bibtex] [ris]
Chapter Roubíček, Tomáš: Across multiscales in solid mechanics via Gamma-convergence in the context of quasistatic evolution, in: Microstructures in Solids: From Quantum Models to Continua, pages 785-787, Mathematisches Forschungsinstitut, 2010. [DOI:10.4171/OWR/2010/14] [Published] [bibtex] [ris]
Roubíček, Tomáš: Rate Independent processes in viscous solids, in: Rate-Independent Evolution and Material Modeling (Special Section of EQUADIFF 2007), Pavia, pages 45-50, Pubblicazione IMATI-CNR, 2010. [Published] [bibtex] [ris]
Article Roubíček, Tomáš and Tomassetti, Giuseppe: Thermodynamics of shape-memory alloys under electric current [DOI:10.1007/s00033-009-0007-1] [bibtex] [ris]
Strachota, Pavel; Beneš, Michal; Grottadaurea, M. and Tintěra, J.: Analysis of the Parallel Finite Volume Solver for the Anisotropic Allen-Cahn Equation in 3D. [URL:http://www.springerlink.com/co...] [bibtex] [ris]
Article Straka, Robert and Beneš, Michal: Numerical simulation of NO production in air-staged pulverized coal fired furnace, The Open Thermodynamics Journal, Vol. 4, 2010. [DOI:10.2174/1874396X01004010027] [Published] [bibtex] [ris]
Chapter Vlasák, Miloslav and Dolejší, Vít: Implicit–Explicit Backward Difference Formulae Discontinuous Galerkin Finite Element Methods for Convection–Diffusion Problems, in: Numerical Mathematics and Advanced Applications 2009, pages 921-928, Springer Berlin Heidelberg, 2010. [DOI:10.1007/978-3-642-11795-4_99] [Published] [bibtex] [ris]
Article Wachsmuth, B and Roubíček, Tomáš: Optimal control of planar flow of incompressible non-Newtonian fluids [DOI:10.4171/ZAA/1412] [bibtex] [ris]
Article Wroblewska, Aneta: Steady flow of non-Newtonian fluids - monotonicity methods in generalized Orlicz spaces [DOI:10.1016/j.na.2010.01.045] [bibtex] [ris]
Article Zhou, Yong and Pokorný, Milan: On the regularity to the solutions of the Navier--Stokes equations via one velocity component, Nonlinearity, Vol. 23, No. 5, pp. 1097--1107, 2010. [DOI:10.1088/0951-7715/23/5/004] [Published] [bibtex] [ris]
2009
Article Bellout, Hamid; Neustupa, Jiří and Penel, Patrick: On viscosity-continuous solutions of the Euler and Navier-Stokes equations with a Navier-type boundary condition [DOI:10.1016/j.crma.2009.09.007] [bibtex] [ris]
Article Beneš, Michal; Fučík, Radek; Mikyška, Jiří and Illangasekare, Tissa H.: Analytical and Numerical Solution for One-Dimensional Two-Phase Flow in Homogeneous Porous Medium, Journal of Porous Media, Vol. 12, No. 12, pp. 1139-1152, 2009. [Published] [bibtex] [ris]
Article Beneš, Michal; Illangasekare, Tissa H. and Mikyška, Jiří: Numerical Investigation of Nonaqueous Phase Liquid Behavior at Heterogeneous Sand Layers Using VODA Multiphase Flow Code, Journal of Porous Media, Vol. 12, No. 7, pp. 685-694, 2009. [DOI:10.1615/JPorMedia.v12.i7.60] [Published] [bibtex] [ris]
Article Beneš, Michal; Kimura, M. and Yazaki, Shigetoshi: Second order numerical scheme for motion of polygonal curves with constant area speed, Interfaces and Free Boundaries, Vol. 11, No. 4, pp. 515-536, 2009. [Published] [bibtex] [ris]
Article Beneš, Michal; Kratochvíl, Jan; Křišťan, Josef; Minárik, Vojtěch and Pauš, P.: A parametric simulation method for discrete dislocation dynamics, European Physical Journal ST, Special Topics, No. 177, pp. 177--192, 2009. [Published] [bibtex] [ris]
Article Beneš, Michal; Mikula, Karol; Oberhuber, Tomáš and Ševčovič, Daniel: Comparison study for Level set and Direct Lagrangian methods for computing Willmore flow of closed planar curves, Computing and Visualization in Science, Vol. 12, No. 6, pp. 307--317, 2009. [DOI:10.1007/s00791-008-0112-2] [Published] [bibtex] [ris]
Benešová, Barbora: Modeling of shape-memory alloys on the mesoscopic level, in: ESOMAT 2009 - 8th European Symposium on Martensitic Transformations, pages 7, EDP Sciences, 2009. [DOI:10.1051/esomat/200903003] [Published] [bibtex] [ris]
Article Bouchitté, Guy; Mielke, Alexander and Roubíček, Tomáš: A complete-damage problem at small strains [bibtex] [ris]
Article Bucur, Dorin and Feireisl, Eduard: The incompressible limit of the full Navier-Stokes-Fourier system on domains with rough boundaries [bibtex] [ris]
Article Bulíček, Miroslav; Ettwein, Frank; Kaplický, Petr and Pražák, Dalibor: The dimension of the attractor for the 3D flow of a non-Newtonian fluid, Communications on Pure and Applied Analysis, Vol. 8, No. 5, pp. 1503--1520, 2009. [DOI:10.3934/cpaa.2009.8.1503] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Feireisl, Eduard and Málek, Josef: A Navier-Stokes-Fourier system for incompressible fluids with temperature dependent material coefficients, Nonlinear Analysis: Real World Applications, Vol. 10, No. 2, pp. 992--1015, 2009. [DOI:10.1016/j.nonrwa.2007.11.018] [Published] [bibtex] [ris]
Article Bulíček, Miroslav and Fišerová, Veronika: Existence theory for steady flows of fluids with pressure and shear rate dependent viscosity, for low values of the power-law index [DOI:10.4171/ZAA/1389] [bibtex] [ris]
Article Bulíček, Miroslav; Frehse, Jens and Málek, Josef: On boundary regularity for the stress in problems of linearized elasto-plasticity, International Journal of Advances in Engineering Sciences and Applied Mathematics, Vol. 1, No. 4, pp. 141-156, 2009. [DOI:10.1007/s12572-010-0001-z] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Gwiazda, Piotr; Málek, Josef and Świerczewska-Gwiazda, Agnieszka: On steady flows of incompressible fluids with implicit power-law-like rheology, Advances in Calculus of Variations, Vol. 2, No. 2, pp. 109--136, 2009. [DOI:10.1515/ACV.2009.006] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Haslinger, Jaroslav; Málek, Josef and Stebel, Jan: Shape Optimization for Navier-Stokes Equations with Algebraic Turbulence Model: Existence Analysis, Applied Mathematics and Optimization, Vol. 60, No. 2, pp. 185-212, 2009. [DOI:10.1007/s00245-009-9066-0] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Rajagopal, K. R.: Mathematical analysis of unsteady flows of fluids with pressure, shear-rate, and temperature dependent material moduli that slip at solid boundaries, SIAM J. Math. Anal., Vol. 41, No. 2, pp. 665--707, 2009. [DOI:10.1137/07069540X] [Published] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Rajagopal, K. R.: Analysis of the flows of incompressible fluids with pressure dependent viscosity fulfilling {$\nu(p,\cdot)\to+\infty$} as {$p\to+\infty$}, Czechoslovak Math. J., Vol. 59(134), No. 2, pp. 503--528, 2009. [DOI:10.1007/s10587-009-0034-2] [Published] [bibtex] [ris]
Bulíček, Miroslav; Málek, Josef and Rajagopal, K. R.: Mathematical Results Concerning the Unsteady Flows of Chemically Reacting Incompressible Fluids [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Bulíček, Miroslav and Pražák, Dalibor: A note on the dimension of the global attractor for an abstract semilinear hyperbolic problem, Applied Mathematics Letters, Vol. 22, No. 7, pp. 1025--1028, 2009. [DOI:10.1016/j.aml.2009.01.027] [Published] [bibtex] [ris]
Article Cianchi, Andrea and Pick, Luboš: Optimal Gaussian Sobolev embeddings [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Dolejší, Vít; Holík, Martin; Hozman, Jiří and Vlasák, Miloslav: Semi-Implicit Solution of the Convection-Diffusion Problems with Applications in Fluid Dynamics, pages 1200-1203, AIP, 2009. [DOI:10.1063/1.3241282] [Published] [bibtex] [ris]
Feireisl, Eduard and Novotný, Antonín: Small Peclet number approximation as a singular limit of the full Navier-Stokes-Fourier system with radiation [bibtex] [ris]
Article Feireisl, Eduard; Petzeltová, Hana and Rocca, Elisabetta: Existence of solutions to a phase transition model with microscopic movements [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Feireisl, Eduard and Vasseur, Alexis: New perspectives in fluid dynamics: Mathematical analysis of a model proposed by Howard Brenner [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Frehse, Jens; Steinhauer, Mark and Weigant, Wladimir: On Stationary Solutions for 2 - D Viscous Compressible Isothermal Navier-Stokes Equations [DOI:10.1007/s00021-009-0005-2] [bibtex] [ris]
Article Gogatishvili, Amiran and Pick, Luboš: Calderón-Type Theorems for Operators of Nonstandard Endpoint Behaviour [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Hoang, H. D.: Epitaxial crystal growth, in: Algoritmy 2009, Proceedings of contributed papers and posters, pages 196--201, 2009. [Published] [bibtex] [ris]
Kreml, Ondřej and Pokorný, Milan: On the local strong solutions for a system describing the flow of a viscoelastic fluid [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Křišťan, Josef; Kratochvíl, Jan; Minárik, Vojtěch and Beneš, Michal: Numerical simulation of interacting dislocations glide in a channel of a persistent slip band [DOI:10.1088/0965-0393/17/4/045009] [bibtex] [ris]
Article Kružík, Martin and Roubíček, Tomáš: Matematické a počítačové modelování aktivních materiálů [bibtex] [ris]
Kukučka, Peter: Incompressible limits for the Navier-Stokes-Fourier Systems on Unbounded Domains under Strong Stratification [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Kukučka, Peter: On the existence of finite energy weak solutions to the Navier-Stokes equations in irregular domains [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Mach, J.: Stability of Stationary States of The Gray-Scott model, in: HPC-Europa: Science and Supercomputing in Europe, report 2008, pages 484--487, 2009. [Published] [bibtex] [ris]
Article Mielke, Alexander and Roubíček, Tomáš: Numerical approaches to rate-independent processes and applications in inelasticity [DOI:10.1051/m2an/2009009] [bibtex] [ris]
Minárik, Vojtěch; Kratochvíl, Jan and Beneš, Michal: Numerical Simulation of Dislocation Dynamics - The Stress Field Evaluation Threshold [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Mucha, Piotr B and Pokorný, Milan: On the steady compressible Navier-Stokes-Fourier system, Communications in Mathematical Physics, Vol. 288, No. 1, pp. 349--377, 2009. [DOI:10.1007/s00220-009-0772-x] [Published] [bibtex] [ris]
Article Nečasová, Šárka and Denisova, Irena: Oberbeck–Boussinesq approximation for the motion of two incompressible fluids, Journal of Mathematical Sciences, Vol. 159, No. 4, pp. 436-451, 2009. [DOI:10.1007/s10958-009-9455-6] [Published] [bibtex] [ris]
Article Pauš, P. and Beneš, Michal: Direct approach to mean-curvature flow with topological changes [bibtex] [ris]
Pauš, P. and Beneš, Michal: Algorithm for topological changes of parametrically described curves, in: Algoritmy 2009, Proceedings of contributed papers and posters, pages 176--184, 2009. [Published] [bibtex] [ris]
Pauš, P.; Beneš, Michal and Kratochvíl, Jan: Discrete Dislocation Dynamics and Mean Curvature Flow, in: Numerical Mathematics and Advanced Applications, Proceedings of ENUMATH 2009, the 8th European Conference on Numerical Mathematics and Advanced Applications, Uppsala, Sweden, pages 721-728, 2009. [Published] [bibtex] [ris]
Article Pokorný, Milan and Zhou, Yong: On a regularity criterion for the Navier-Stokes equations involving gradient of one velocity component [DOI:10.1063/1.3268589] [bibtex] [ris]
Article Průša, Vít: On the influence of boundary condition on stability of Hagen-Poiseuille flow [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Roubíček, Tomáš: On non-Newtonian fluids with energy transfer [DOI:10.1007/s00021-007-0250-1] [bibtex] [ris]
Article Roubíček, Tomáš: Rate-independent processes in viscous solids at small strains [DOI:10.1002/mma.1069] [bibtex] [ris]
Article Roubíček, Tomáš; Scardia, Lucia and Zanini, Chiara: Quasistatic delamination problem [DOI:10.1007/s00161-009-0106-4] [bibtex] [ris]
Article Roubíček, Tomáš; Tomassetti, Giuseppe and Zanini, Chiara: The Gilbert equation with dry-friction-type damping [DOI:10.1016/j.jmaa.2009.01.0] [bibtex] [ris]
Strachota, Pavel: Application of Anisotropic Diffusion in MR Tractography [bibtex] [ris]
Strachota, Pavel: Anisotropic Diffusion in Mathematical Visualization, in: HPC-Europa: Science and Supercomputing in Europe, pages 826--831, CINECA Consortio Interuniversitario, 2009. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Strachota, Pavel: Antidissipative Numerical Schemes for the Anisotropic Diffusion Operator in Problems for the Allen-Cahn Equation, in: Algoritmy 2009, Proceedings of contributed papers and posters, pages 134--142, 2009. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Strachota, Pavel: Implementation of the MR Tractography Visualization Kit Based on the Anisotropic Allen-Cahn Equation [bibtex] [ris]
Strachota, Pavel: Parallel Algorithms for Diffusion-based Tensor Field Visualization in Mathematics and Medicine [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Straka, Robert; Makovička, Jindřich; Beneš, Michal and Havlena, V.: Numerical model of pulverized coal combustion in furnace [bibtex] [ris]
Suzuki, A: An Iterative Substructuring Method for the Discretized Stokes Equations by a Stabilized Finite Element Method [bibtex] [ris]
Suzuki, A: An iterative substructuring solver for the Stokes equations [bibtex] [ris]
Vlasák, Miloslav: Second order time discontinuous Galerkin for nonlinear convection-diffusion problems, in: ALGORITMY 2009, 18th Conference on Scientific Computing Vysoké Tatry – Podbanské, Slovakia, March 15 – 20, 2009, pages 276-283, Slovak University of Technology, Bratislava, 2009. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Wroblewska, Aneta: Existence results for unsteady flows of nonhomogeneous non-Newtonian incompressible fluids - monotonicity methods in generalized Orlicz spaces [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
2008
Article Abels, Helmut and Feireisl, Eduard: On a diffuse interface model for a two-phase flow of compressible viscous fluids [bibtex] [ris]
Article Abels, Helmut; Krbec, Miroslav and Schumacher, Katrin: On the trace space of a Sobolev space with a radial weight [bibtex] [ris]
Article Bárta, Tomáš: Smooth solutions of Volterra equations via semigroups [bibtex] [ris]
Article Bartels, Sören and Roubíček, Tomáš: Thermoviscoplasticity at small strains [DOI:10.1002/zamm.200800042] [bibtex] [ris]
Article Beneš, Michal; Kimura, M.; Pauš, P.; Ševčovič, Daniel; Tsujikawa, T. and Yazaki, Shigetoshi: Application of a curvature adjusted method in image segmentation [bibtex] [ris]
Article Beneš, Michal; Strachota, Pavel and Čulík, Z.: Quantitative Aspects of Microstructure Formation in Solidification [bibtex] [ris]
Article Březina, Jan and Novotný, Antonín: On weak solutions of steady Navier-Stokes equations for monatomic gas [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Bucur, Dorin; Feireisl, Eduard and Nečasová, Šárka: Influence of wall roughness on the slip behaviour of viscous fluids [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Bucur, Dorin; Feireisl, Eduard and Nečasová, Šárka: On the asymptotic limit of flows past a ribbed boundary [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Bucur, Dorin; Feireisl, Eduard; Nečasová, Šárka and Wolf, Joerg: On the asymptotic limit of the Navier-Stokes system on domains with rough boundaries [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Bulíček, Miroslav and Kaplický, Petr: Incompressible fluids with shear rate and pressure dependent viscosity: regularity of steady planar flows [DOI:10.3934/dcdss.2008.1.41] [bibtex] [ris]
Article Cianchi, Andrea; Kerman, Ron and Pick, Luboš: Boundary Trace Inequalities and Rearrangements, J. Anal. Math., Vol. 105, pp. 241-265, 2008. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Diening, Lars; Málek, Josef and Steinhauer, Mark: On Lipschitz truncations of Sobolev functions (with variable exponent) and their selected applications, ESAIM Control Optim. Calc. Var., Vol. 14, No. 2, pp. 211--232, 2008. [DOI:10.1051/cocv:2007049] [Published] [bibtex] [ris]
Article Dolejší, Vít; Feistauer, Miloslav; Kučera, Václav and Sobotíková, Veronika: An optimal {$L^\infty(L^2)$}-error estimate for the discontinuous {G}alerkin approximation of a nonlinear non-stationary convection-diffusion problem [DOI:10.1093/imanum/drm023] [bibtex] [ris]
Article Dolejší, Vít and Vlasák, Miloslav: Analysis of a BDF-DGFE scheme for nonlinear convection-diffusion problems [DOI:10.1007/s00211-008-0178-2] [bibtex] [ris]
Article Farwig, Reinhard and Neustupa, Jiří: On the spectrum of an Oseen-type operator arising from flow past a rotating body [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Feireisl, Eduard; Hillairet, Matthieu and Nečasová, Šárka: On the motion of several rigid bodies in an incompressible non-Newtonian fluid [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Feireisl, Eduard; Málek, Josef and Novotný, Antonín: Navier´s slip and incompressible limits in domains with variable bottoms, Discrete and Continuous Dynamical Systems - Series S, Vol. 1, No. 3, pp. 427-460, 2008. [DOI:10.3934/dcdss.2008.1.427] [Published] [bibtex] [ris]
Article Feireisl, Eduard; Málek, Josef; Novotný, Antonín and Straškraba, Ivan: Anelastic approximation as a singular limit of the compressible Navier-Stokes system [DOI:10.1080/03605300601088799] [bibtex] [ris]
Article Feireisl, Eduard; Novotný, Antonín and Petzeltová, Hana: Layered incompressible fluid flow equations in the limit of low Mach number and strong stratification [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Feireisl, Eduard; Petzeltová, Hana and Trivisa, Konstantina: Multicomponent reactive flows: global-in-time existence for large data [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Feistauer, Miloslav and Kučera, Václav: A New Technique for the Numerical Solution of the Compressible Euler Equations with Arbitrary Mach Numbers [bibtex] [ris]
Article Feistauer, Miloslav and Kučera, Václav: Analysis of the DGFEM for nonlinear convection-diffusion problems [bibtex] [ris]
Chapter Felcman, Jiří and Kubera, Petr: An adaptive finite volume method for non-stationary problems [bibtex] [ris]
Felcman, Jiří and Kubera, Petr: A Comparison of Adaptation Techniques for the Solution of [bibtex] [ris]
Fučík, Radek: Implicit Numerical Scheme for Modelling Dynamic Effect in Capillary Pressure [bibtex] [ris]
Article Fučík, Radek; Mikyška, Jiří; Beneš, Michal and Illangasekare, Tissa H.: Semianalytical Solution for Two-Phase Flow in Porous Media with a Discontinuity, Vadose Zone Journal, Vol. 7, No. 3, pp. 1001-1007, 2008. [DOI:10.2136/vzj2007.0155] [Published] [bibtex] [ris]
Article Hron, Jaroslav; Le Roux, C.; Málek, Josef and Rajagopal, K. R.: Flows of incompressible fluids subject to Navier's slip on the boundary [DOI:10.1016/j.camwa.2008.03.058] [bibtex] [ris]
Chapter Hron, Jaroslav and Turek, Stefan: Numerical Techniques for Multiphase Flow with Liquid-Solid Interaction [bibtex] [ris]
Chapter Kimura, M.: Shape derivative of minimum potential energy: abstract theory and applications, in: Topics in mathematical modeling, pages 1-92, MATFYZPRESS, Charles University in Prague, 2008. [Published] [bibtex] [ris]
Kobera, Marek: Brinkman Equations as a Model for Flows in Porous Media [bibtex] [ris]
Article Koutný, Jan; Kružík, Martin; Kurdila, Andrew J. and Roubíček, Tomáš: Identification of Preisach-type hysteresis operators [DOI:10.1080/01630560701872730] [bibtex] [ris]
Kučera, Václav: DG for compressible inviscid and viscous flows with a large range of Mach numbers [bibtex] [ris]
Kučera, Václav; Feistauer, Miloslav and Prokopová, Jaroslava: Discontinuous Galerkin Simulation of Compressible Flow in Time-dependent Domains [bibtex] [ris]
Kučera, Václav; Feistauer, Miloslav and Prokopová, Jaroslava: The Discontinuous Galerkin Method for Compressible Flows in Moving Domains [bibtex] [ris]
Article Lauschmann, H.; Bednařík., P.; Sekerešová, Z. and Beneš, Michal: Fractal Image Feature Vectors with Applications in Fractography [bibtex] [ris]
Article Liska, Richard and Shashkov, Mikhail: Enforcing the discrete maximum principle for linear finite element solutions of second-order elliptic problems, Communications in Computational Physics, Vol. 3, No. 4, pp. 852--877, 2008. [Published] [bibtex] [ris]
Mach, J.: Numerical solution of the 2D Gray-Scott model [bibtex] [ris]
Chapter Mach, J.: Qualitative study of the Gray-Scott model [bibtex] [ris]
Article Málek, Josef: Mathematical properties of flows of incompressible power-law-like fluids that are described by implicit constitutive relations [URL:http://etna.math.kent.edu] [bibtex] [ris]
Article Málek, Josef and Rajagopal, K. R.: A thermodynamic framework for a mixture of two liquids [DOI:10.1016/j.nonrwa.2007.04.008] [bibtex] [ris]
Article Medkova, Dagmar and Varnhorn, Werner: Boundary value problems for the Stokes equations with jumps in open sets [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Mielke, Alexander; Roubíček, Tomáš and Stefanelli, Ulisse: {$\Gamma$}-limits and relaxations for rate-independent evolutionary problems [bibtex] [ris]
Chapter Neustupa, Jiří and Penel, Patrick: The Navier-Stokes equation with inhomogeneous boundary conditions based on vorticity [DOI:10.4064/bc81-0-21] [bibtex] [ris]
Article Pokorný, Milan and Mucha, Piotr B: 3D steady compressible Navier-Stokes equations, Discrete and Continuous Dynamical Systems - Series S, Vol. 1, No. 1, pp. 151--163, 2008. [DOI:10.3934/dcdss.2008.1.151] [Published] [bibtex] [ris]
Roubíček, Tomáš: Approximation in multiscale modelling of microstructure evolution in shape-memory alloys [bibtex] [ris]
Strachota, Pavel: Algorithms for Diffusion-based Tensor Field Visualization in Mathematics and Medicine [bibtex] [ris]
Váchal, Pavel: Rezoning and Remapping for ALE Simulations in Fluid Dynamics and Plasma Physics [bibtex] [ris]
Vlasák, Miloslav and Dolejší, Vít: Implicit-Explicit Runge-Kutta discontinuous Galerkin finite element method for convection-diffusion problems, in: Numerical Mathematics and Advanced Applications, proceedings of ENUMATH conference 2007, Graz Austria, pages 355-362, Springer, 2008. [Published] [bibtex] [ris]
Chapter Wolf, Joerg: The Caffarelli-Kohn-Nirenberg Theorem - A Direct Proof by Campanato's Method [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Chapter Yazaki, Shigetoshi: An area-preserving crystalline curvature flow equation, in: Topics in mathematical modeling, pages 169-213, MATFYZPRESS, Charles University in Prague, 2008. [Published] [bibtex] [ris]
2007
Article Beneš, Michal: Computational studies of anisotropic diffuse interface model of microstructure formation in solidification [bibtex] [ris]
Beneš, Michal; Chabiniok, R.; Kimura, M. and Mikula, Karol: Nonlinear Gauss-Seidel Scheme for Allen Cahn Type Systems [bibtex] [ris]
Beneš, Michal; Kimura, M. and Yazaki, Shigetoshi: Analytical and Numerical Aspects on Motion of Polygonal Curves with Constant Area Speed [bibtex] [ris]
Bradji, Abdallah and Holzbecher, Ekkehard: On the Convergence Order of COMSOL Solutions [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Bulíček, Miroslav; Málek, Josef and Rajagopal, K. R.: Navier's slip and evolutionary Navier-Stokes-like systems with pressure and shear-rate dependent viscosity [DOI:10.1512/iumj.2007.56.2997] [bibtex] [ris]
Chapter Farwig, Reinhard; Nečasová, Šárka and Neustupa, Jiří: On the essential spectrum of a {S}tokes-type operator arising from flow around a rotating body in the {$L^q$}-framework [bibtex] [ris]
Article Farwig, Reinhard and Neustupa, Jiří: On the spectrum of a Stokes-type operator arising from flow around a rotating body [DOI:10.1007/s00229-007-0078-2] [bibtex] [ris]
Article Feistauer, Miloslav and Kučera, Václav: On a robust discontinuous Galerkin technique for the solution of compressible flow [DOI:10.1016/j.jcp.2007.01.035] [bibtex] [ris]
Feistauer, Miloslav; Kučera, Václav and Prokopová, Jaroslava: Numerical Solution of Compressible Flow in a Channel with Moving Walls [bibtex] [ris]
Felcman, Jiří and Kubera, Petr: A Vertex Quality Parameter Moving Mesh Method [bibtex] [ris]
Article Felcman, Jiří and Kubera, Petr: A mesh adaptation for non-stationary problems [DOI:10.1002/pamm.200700049] [bibtex] [ris]
Article Fučík, Radek; Mikyška, Jiří; Beneš, Michal and Illangasekare, Tissa H.: An Improved Semi-Analytical Solution for Verification of Numerical Models of Two-Phase Flow in Porous Media [bibtex] [ris]
Article Grasselli, Maurizio and Pražák, Dalibor: Exponential attractors for a class of reaction-diffusion problems with time delays [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Gwiazda, Piotr; Málek, Josef and Świerczewska-Gwiazda, Agnieszka: On flows of an incompressible fluid with a discontinuous power-law-like rheology [DOI:10.1016/j.camwa.2006.02.037] [bibtex] [ris]
Haslinger, Jaroslav; Málek, Josef and Stebel, Jan: An existence result for the shape optimization problem governed by Navier-Stokes equations with algebraic turbulence model [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Haslinger, Jaroslav; Vlach, Oldřich; Baniotopoulos, C. and Dostál, Z: The FETI-DP domain decomposition method for quasistatic contact problems with Coulomb friction [bibtex] [ris]
Article Hron, Jaroslav and Mádlík, Martin: Fluid-structure interaction with applications in biomechanics [bibtex] [ris]
Chapter Hron, Jaroslav and Turek, Stefan: A monolithic FEM/multigrid solver for an ALE formulation of fluid-structure interaction with applications in biomechanics [bibtex] [ris]
Kimura, M.; Beneš, Michal and Yazaki, Shigetoshi: Crystalline Motion in Hele-Shaw Cells [bibtex] [ris]
Article Koutný, Jan; Kružík, Martin and Roubíček, Tomáš: A mesoscopical model of shape memory alloys [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Kreml, Ondřej: Mathematical results for some models of viscoelastic fluids, in: WDS 2007 - Proceedings of Contributed Papers, pages 198-203, 2007. [URL:http://www.karlin.mff.cuni.cz/...] [Published] [bibtex] [ris]
Article Kreml, Ondřej and Pokorný, Milan: A regularity criterion for the angular velocity component in axisymmetric Navier-Stokes equations [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Křišťan, Josef and Kratochvíl, Jan: Interactions of glide dislocations in a channel of a persistent slip band [DOI:10.1080/14786430701576324] [bibtex] [ris]
Chapter Kučera, Petr; Neustupa, Jiří and Penel, Patrick: Navier-Stokes' equation with the generalized impermeability boundary conditions and initial data in domains of powers of the Stokes operator [bibtex] [ris]
Kučera, Václav: The Discontinuous Galerkin Method for the Compressible Navier-Stokes Equations [bibtex] [ris]
Kučera, Václav: The Discontinuous Galerkin Method for Viscous Compressible Flows [bibtex] [ris]
Kučera, Václav: Discontinuous Galerkin Method for the Numerical Solution of Inviscid and Viscous Compressible Flow [bibtex] [ris]
Kučera, Václav and Prokopová, Jaroslava: DG Method for the Solution of Compressible Flow in a Channel with Moving Walls [bibtex] [ris]
Article Liska, Richard and Váchal, Pavel: Quantifier elimination supported proofs in the numerical treatment of fluid flows [bibtex] [ris]
Mach, J.: Computational Study of the Gray-Scott Model [bibtex] [ris]
Article Málek, Josef and Rajagopal, K. R.: Incompressible rate type fluids with pressure and shear-rate dependent material moduli [DOI:10.1016/j.nonrwa.2005.06.006] [bibtex] [ris]
Mikyška, Jiří; Beneš, Michal and Illangasekare, Tissa H.: VODA Multiphase Flow Code for Investigation of NAPL Behavior at Heterogeneous Sand Layers, 2007. [Published] [bibtex] [ris]
Article Mikyška, Jiří and Illangasekare, Tissa H.: Influence of capillary pressure parameters on two-phase flow [bibtex] [ris]
Article Mikyška, Jiří and Illangasekare, Tissa H.: Application of a multiphase flow code for investigation of influence of capillary pressure parameters on two-phase flow [bibtex] [ris]
Article Minárik, Vojtěch and Kratochvíl, Jan: Dislocation dyanmics---analytical description of the interaction force between dipolar loops [bibtex] [ris]
Article Neustupa, Jiří and Penel, Patrick: On regularity of a weak solution to the Navier-Stokes equation with generalized impermeability boundary conditions [DOI:10.1016/j.na.2006.02.043] [bibtex] [ris]
Article Oberhuber, Tomáš: Finite difference scheme for the Willmore flow of graphs [bibtex] [ris]
Pauš, P.: Numerical Simulation of Dislocation Dynamics [bibtex] [ris]
Article Pošta, Miroslav and Roubíček, Tomáš: Optimal control of Navier-Stokes equations by Oseen approximation [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Poul, Lukáš: Existence of weak solutions to the Navier-Stokes-Fourier system on Lipschitz domains [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Pražák, Dalibor: Exponential attractors for abstract parabolic systems with bounded delay [bibtex] [ris]
Article Pražák, Dalibor: Fourier series and the Colombeau algebra on the unit circle [bibtex] [ris]
Article Pražák, Dalibor: Dynamics of trajectories and the finite-dimensional reduction of dissipative evolution equations [bibtex] [ris]
Article Roubíček, Tomáš: Incompressible ionized non-Newtonian fluid mixtures [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Article Roubíček, Tomáš: Modelling of thermodynamics of martensitic transformation in shape-memory alloys [URL:http://www.karlin.mff.cuni.cz/...] [bibtex] [ris]
Strachota, Pavel: Vector field visualization by means of anisotropic diffusion [bibtex] [ris]
Article Straka, Robert and Makovička, Jindřich: Model of pulverized coal combustion in a furnace [bibtex] [ris]
Straka, Robert; Makovička, Jindřich; Beneš, Michal and Havlena, V.: Numerical Simulation of Coal Combustion in Industrial Boiler, pages 7--18, 2007. [Published] [bibtex] [ris]
Vlasák, Miloslav: Time Discretizations for Scalar Nonlinear Convection-Difusion Prolems [bibtex] [ris]
Article Yazaki, Shigetoshi: Asymptotic behavior of solutions to an area-preserving motion by crystalline curvature [bibtex] [ris]
Article Yazaki, Shigetoshi: On the tangential velocity arising in a crystalline approximation of evolving plane curves [bibtex] [ris]
2006
Bauer, P. and Jaňour, Z.: Flow and pollution transport in the street canyon [bibtex] [ris]
Bednařík., P.: MULTIFRACTAL ANALYSIS WITH APPLICATIONS IN FRACTURE MECHANICS [bibtex] [ris]
Brand, S.: PARALLEL ALGORITHM FOR NUMERICAL SOLUTION OF THE SHALLOW WATER EQUATION [bibtex] [ris]
Dolejší, Vít: Numerical simulation of compressible flows with the aid of the BDF - DGFE scheme [bibtex] [ris]
Article Feireisl, Eduard and Málek, Josef: On the Navier-Stokes equations with temperature-dependent transport coefficients [bibtex] [ris]
Feistauer, Miloslav and Kučera, Václav: A New Technique for the Numerical Solution of the Compressible Euler Equations with Arbitrary Mach Numbers [bibtex] [ris]
Article Málek, Josef and Rajagopal, K. R.: On the modeling of inhomogeneous incompressible fluid-like bodies [DOI:10.1016/j.mechmat.2005.05.020] [bibtex] [ris]
Málek, Josef and Rajagopal, K. R.: Mathematical properties of the equations governing the flow of fluids with pressure and shear rate dependent viscosities [DOI:10.1016/S1874-5792(07)80011-5] [bibtex] [ris]
Article Pražák, Dalibor: On the dynamics of equations with infinite delay [bibtex] [ris]
Straka, Robert: MODEL OF PULVERIZED COAL COMBUSTION IN FURNACE [bibtex] [ris]
Preprint Roubíček, Tomáš: Geophysical models of heat and fluid flow in damageable poro-elastic continua [bibtex] [ris]
Publication database ↵ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6743584275245667, "perplexity": 22372.949905785594}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178373241.51/warc/CC-MAIN-20210305183324-20210305213324-00000.warc.gz"} |
https://afni.nimh.nih.gov/pub/dist/doc/htmldoc/programs/ConvertSurface_sphx.html | # ConvertSurface¶
Usage: ConvertSurface <-i_TYPE inSurf> <-o_TYPE outSurf>
[<-sv SurfaceVolume [VolParam for sf surfaces]>]
[-tlrc] [-MNI_rai/-MNI_lpi][-xmat_1D XMAT]
reads in a surface and writes it out in another format.
Note: This is a not a general utility conversion program.
Only fields pertinent to SUMA are preserved.
Specifying input surfaces using -i or -i_TYPE options:
-i_TYPE inSurf specifies the input surface,
TYPE is one of the following:
fs: FreeSurfer surface.
If surface name has .asc it is assumed to be
in ASCII format. Otherwise it is assumed to be
in BINARY_BE (Big Endian) format.
Patches in Binary format cannot be read at the moment.
sf: SureFit surface.
You must specify the .coord followed by the .topo file.
vec (or 1D): Simple ascii matrix format.
You must specify the coord (NodeList) file followed by
the topo (FaceSetList) file.
coord contains 3 floats per line, representing
X Y Z vertex coordinates.
topo contains 3 ints per line, representing
v1 v2 v3 triangle vertices.
ply: PLY format, ascii or binary.
Only vertex and triangulation info is preserved.
stl: STL format, ascii or binary.
This format of no use for much of the surface-based
analyses. Objects are defined as a soup of triangles
with no information about which edges they share. STL is only
useful for taking surface models to some 3D printing
software.
mni: MNI .obj format, ascii only.
Only vertex, triangulation, and node normals info is preserved.
byu: BYU format, ascii.
Polygons with more than 3 edges are turned into
triangles.
bv: BrainVoyager format.
Only vertex and triangulation info is preserved.
dx: OpenDX ascii mesh format.
Only vertex and triangulation info is preserved.
Requires presence of 3 objects, the one of class
'field' should contain 2 components 'positions'
and 'connections' that point to the two objects
containing node coordinates and topology, respectively.
obj: OBJ file format for triangular meshes only. The following
primitives are preserved: v (vertices), f (faces, triangles
only), and p (points)
Note that if the surface filename has the proper extension,
it is enough to use the -i option and let the programs guess
the type from the extension.
You can also specify multiple surfaces after -i option. This makes
it possible to use wildcards on the command line for reading in a bunch
of surfaces at once.
-onestate: Make all -i_* surfaces have the same state, i.e.
they all appear at the same time in the viewer.
By default, each -i_* surface has its own state.
For -onestate to take effect, it must precede all -i
options with on the command line.
-anatomical: Label all -i surfaces as anatomically correct.
Again, this option should precede the -i_* options.
More variants for option -i:
-----------------------------
You can also load standard-mesh spheres that are formed in memory
with the following notation
-i ldNUM: Where NUM is the parameter controlling
the mesh density exactly as the parameter -ld linDepth
does in CreateIcosahedron. For example:
suma -i ld60
create on the fly a surface that is identical to the
one produced by: CreateIcosahedron -ld 60 -tosphere
-i rdNUM: Same as -i ldNUM but with NUM specifying the equivalent
of parameter -rd recDepth in CreateIcosahedron.
To keep the option confusing enough, you can also use -i to load
template surfaces. For example:
suma -i lh:MNI_N27:ld60:smoothwm
will load the left hemisphere smoothwm surface for template MNI_N27
at standard mesh density ld60.
The string following -i is formatted thusly:
HEMI:TEMPLATE:DENSITY:SURF where:
HEMI specifies a hemisphere. Choose from 'l', 'r', 'lh' or 'rh'.
You must specify a hemisphere with option -i because it is
supposed to load one surface at a time.
You can load multiple surfaces with -spec which also supports
these features.
TEMPLATE: Specify the template name. For now, choose from MNI_N27 if
you want to use the FreeSurfer reconstructed surfaces from
the MNI_N27 volume, or TT_N27
Those templates must be installed under this directory:
/home/afniHQ/.afni/data/
https://afni.nimh.nih.gov/pub/dist/tgz/suma_MNI_N27.tgz
and/or
https://afni.nimh.nih.gov/pub/dist/tgz/suma_TT_N27.tgz
and/or
https://afni.nimh.nih.gov/pub/dist/tgz/suma_MNI152_2009.tgz
and untar them under directory /home/afniHQ/.afni/data/
DENSITY: Use if you want to load standard-mesh versions of the template
surfaces. Note that only ld20, ld60, ld120, and ld141 are in
the current distributed templates. You can create other
densities if you wish with MapIcosahedron, but follow the
same naming convention to enable SUMA to find them.
SURF: Which surface do you want. The string matching is partial, as long
as the match is unique.
So for example something like: suma -i l:MNI_N27:ld60:smooth
is more than enough to get you the ld60 MNI_N27 left hemisphere
smoothwm surface.
The order in which you specify HEMI, TEMPLATE, DENSITY, and SURF, does
not matter.
For template surfaces, the -sv option is provided automatically, so you
can have SUMA talking to AFNI with something like:
suma -i l:MNI_N27:ld60:smooth &
afni -niml /home/afniHQ/.afni/data/suma_MNI_N27
-ipar_TYPE ParentSurf specifies the parent surface. Only used
when -o_fsp is used, see -o_TYPE options.
Specifying a Surface Volume:
-sv SurfaceVolume [VolParam for sf surfaces]
If you supply a surface volume, the coordinates of the input surface.
are modified to SUMA's convention and aligned with SurfaceVolume.
You must also specify a VolParam file for SureFit surfaces.
Specifying output surfaces using -o or -o_TYPE options:
-o_TYPE outSurf specifies the output surface,
TYPE is one of the following:
fs: FreeSurfer ascii surface.
fsp: FeeSurfer ascii patch surface.
In addition to outSurf, you need to specify
the name of the parent surface for the patch.
using the -ipar_TYPE option.
This option is only for ConvertSurface
sf: SureFit surface.
For most programs, you are expected to specify prefix:
i.e. -o_sf brain. In some programs, you are allowed to
specify both .coord and .topo file names:
i.e. -o_sf XYZ.coord TRI.topo
The program will determine your choice by examining
the first character of the second parameter following
-o_sf. If that character is a '-' then you have supplied
a prefix and the program will generate the coord and topo names.
vec (or 1D): Simple ascii matrix format.
For most programs, you are expected to specify prefix:
i.e. -o_1D brain. In some programs, you are allowed to
specify both coord and topo file names:
i.e. -o_1D brain.1D.coord brain.1D.topo
coord contains 3 floats per line, representing
X Y Z vertex coordinates.
topo contains 3 ints per line, representing
v1 v2 v3 triangle vertices.
ply: PLY format, ascii or binary.
stl: STL format, ascii or binary (see also STL under option -i_TYPE).
byu: BYU format, ascii or binary.
mni: MNI obj format, ascii only.
You can also enforce the encoding of data arrays
by using gii_asc, gii_b64, or gii_b64gz for
ASCII, Base64, or Base64 Gzipped.
If AFNI_NIML_TEXT_DATA environment variable is set to YES, the
the default encoding is ASCII, otherwise it is Base64.
obj: No support for writing OBJ format exists yet.
Note that if the surface filename has the proper extension,
it is enough to use the -o option and let the programs guess
the type from the extension.
You can alternately set gifti data arrays encoding with:
-xml_b64: For Base64 (more compact)
-xml_b64gz: For Base64 GZIPPED (most compact, needs gzip libraries)
If AFNI_NIML_TEXT_DATA environment variable is set to YES, the
the default is -xml_ascii, otherwise it is -xml_b64
-orient_out STR: Output coordinates in STR coordinate system.
STR is a three character string following AFNI's
naming convention. The program assumes that the
native orientation of the surface is RAI, unless you
use the -MNI_lpi option. The coordinate transformation
is carried out last, just before writing the surface
to disk.
-native: Write the output surface in the coordinate system native to its
format.
Option makes sense for BrainVoyager, Caret/SureFit and
FreeSurfer surfaces.
But the implementation for Caret/Surefit is not finished yet
-make_consistent: Check the consistency of the surface's mesh (triangle
winding). This option will write out a new surface
even if the mesh was consistent.
See SurfQual -help for mesh checks.
-flip_orient: Flip the winding of the triangles
-acpc: Apply acpc transform (which must be in acpc version of
SurfaceVolume) to the surface vertex coordinates.
This option must be used with the -sv option.
-tlrc: Apply Talairach transform (which must be a talairach version of
SurfaceVolume) to the surface vertex coordinates.
This option must be used with the -sv option.
-MNI_rai/-MNI_lpi: Apply Andreas Meyer Lindenberg's transform to turn
AFNI tlrc coordinates (RAI) into MNI coord space
in RAI (with -MNI_rai) or LPI (with -MNI_lpi)).
NOTE: -MNI_lpi option has not been tested yet (I have no data
to test it on. Verify alignment with AFNI and please report
any bugs.
This option can be used without the -tlrc option.
But that assumes that surface nodes are already in
AFNI RAI tlrc coordinates .
NOTE: The vertex coordinates coordinates of the input surfaces are only
transformed if -sv option is used. If you do transform surfaces,
take care not to load them into SUMA with another -sv option.
-patch2surf: Change a patch, defined here as a surface with a mesh that
uses only a subset of the full nodelist, to a surface
where all the nodes in nodelist are used in the mesh.
Note that node indices will no longer correspond between
the input patch and the output surface.
-merge_surfs: Merge multitudes of surfaces on the command line into one
big surface before doing anything else to the surface.
This is for the moment the only option for which you
should specify more than one input surface on the command
line. For example:
ConvertSurface -i lh.smoothwm.gii -i rh.smoothwm.gii \
-merge_surfs -o_gii lrh.smoothwm.gii
Options for coordinate projections:
-node_depth DEPTHPREF: Project all coordinates onto the principal
direction and output of depth/height of each
node relative to the outlying projection point.
This option is processed right before -pc_proj,
should that option also be requested.
This option outputs file DEPTHPREF.pcdepth.1D.dset
which contains node index, followed by depth, then
-pc_proj ONTO PREFIX: Project coordinates onto ONTO, where ONTO is one
of the parameters listed below.
ONTO values for plane projections along various normals:
PC0_plane = normal is 1st principal vector
PC1_plane = normal is 2nd principal vector
PC2_plane = normal is 3rd principal vector
PCZ_plane = normal is component closest to Z axis
PCY_plane = normal is component closest to Y axis
PCX_plane = normal is component closest to X axis
ONTO values for line projections:
PC0_dir = project along 1st principal vector
PC1_dir = project along 2nd principal vector
PC2_dir = project along 3rd principal vector
PCZ_dir = project along component closest to Z axis
PCY_dir = project along component closest to Y axis
PCX_dir = project along component closest to X axis
PREFIX is used to form the name of the output file containing
the projected coordinates. File PREFIX.xyzp.1D.coord
contains the projected coordinates.
Note: This is the last operation to be performed by this program,
and no surfaces are written out in the end.
Options for applying arbitrary affine transform:
[xyz_new] = [Mr] * [xyz_old - cen] + D + cen
-xmat_1D mat: Apply transformation specified in 1D file mat.1D.
to the surface's coordinates.
[mat] = [Mr][D] is of the form:
r11 r12 r13 D1
r21 r22 r23 D2
r31 r32 r33 D3
or
r11 r12 r13 D1 r21 r22 r23 D2 r31 r32 r33 D3
-ixmat_1D mat: Same as xmat_1D except that mat is replaced by inv(mat)
NOTE: For both -xmat_1D and -ixmat_1D, you can replace mat with
one of the special strings:
'RandShift', 'RandRigid', or 'RandAffine' which would create
a transform on the fly.
You can also use 'NegXY' to flip the sign of X and Y
coordinates.
-seed SEED: Use SEED to seed the random number generator for random
matrix generation
-XYZscale sX sY sZ: Scale the coordinates by sX sY sZ.
This option essentially turns sX sY sZ.
into a -xmat_1D option. So you cannot mix
and match.
-xcenter x y z: Use vector cen = [x y z]' for rotation center.
Default is cen = [0 0 0]'
-polar_decomp: Apply polar decomposition to mat and preserve
orthogonal component and shift only.
This option can only be used in conjunction with
-xmat_1D
[-novolreg]: Ignore any Rotate, Volreg, Tagalign,
or WarpDrive transformations present in
the Surface Volume.
[-noxform]: Same as -novolreg
[-setenv "'ENVname=ENVvalue'"]: Set environment variable ENVname
to be ENVvalue. Quotes are necessary.
Example: suma -setenv "'SUMA_BackgroundColor = 1 0 1'"
in the output of 'suma -help'
Common Debugging Options:
[-trace]: Turns on In/Out debug and Memory tracing.
For speeding up the tracing log, I recommend
you redirect stdout to a file when using this option.
For example, if you were running suma you would use:
suma -spec lh.spec -sv ... > TraceFile
This option replaces the old -iodbg and -memdbg.
[-TRACE]: Turns on extreme tracing.
[-nomall]: Turn off memory tracing.
[-yesmall]: Turn on memory tracing (default).
NOTE: For programs that output results to stdout
(that is to your shell/screen), the debugging info
might get mixed up with your results.
Global Options (available to all AFNI/SUMA programs)
-h: Mini help, at time, same as -help in many cases.
-help: The entire help output
-HELP: Extreme help, same as -help in majority of cases.
-h_view: Open help in text editor. AFNI will try to find a GUI editor
-hview : on your machine. You can control which it should use by
setting environment variable AFNI_GUI_EDITOR.
-h_web: Open help in web browser. AFNI will try to find a browser.
-hweb : on your machine. You can control which it should use by
setting environment variable AFNI_GUI_EDITOR.
-h_find WORD: Look for lines in this programs's -help output that match
(approximately) WORD.
-h_raw: Help string unedited
-h_spx: Help string in sphinx loveliness, but do not try to autoformat
-h_aspx: Help string in sphinx with autoformatting of options, etc.
-all_opts: Try to identify all options for the program from the
output of its -help option. Some options might be missed
and others misidentified. Use this output for hints only.
Compile Date:
Aug 5 2022 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.49621719121932983, "perplexity": 16505.047971211996}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-33/segments/1659882572221.38/warc/CC-MAIN-20220816060335-20220816090335-00755.warc.gz"} |
https://www.physicsforums.com/threads/kinetic-energy-of-a-charge.177048/ | # Kinetic energy of a charge
1. Jul 14, 2007
### Aerosion
1. The problem statement, all variables and given/known data
I don't want to sound like I'm asking anyone to do my homework for me, but I really don't know how to find this.
Let me give an example problem: A uniform electric field of 2kN/C is in the x direction. A point charge Q=3 microcoloumbs initially at reast at the origin is released. What is the kinetic energy when it is at x=4m and what is the change in potential energy of the charge from x=0 to x=4m?
2. Relevant equations
3. The attempt at a solution
I know that the potential energy difference is the negative of the kinetic energy of the charge, and I know how to get the potential energy (integrate the electric field with regard to the increase in x and multiply by the negative of the charge) but I'd rather know exactly how to find the kinetic energy of a charge.
2. Jul 14, 2007
### Staff: Mentor
Sounds to me like you just described how to find the KE of a charge as it is accelerated in an electric field. So I'm unclear what the problem is. Why don't you show your work for that sample problem and tell us where you get stuck?
3. Jul 14, 2007
### Aerosion
Well, that's the thing: I don't know how to find the kinetic energy of a charge; as in I'm unclear as to what the formula is. That's why I said that I don't want anyone to think that they're doing homework for me: because I don't know how to get started.
Like, I know that KE=1/2mv^2, but I don't think that's any use in this particular problem. If the formula for KE of a charge is similiar to the potential energy difference of a charge, and if I've already found it out (unknowingly), then could someone tell me?
4. Jul 14, 2007
### Aerosion
Oh oh...and the work I did for PE is...
I used the change in potential energy equation -q=(integrate)E*ds, and subsituated 3microcoloumbs for q, 2kn/C for E, and 0 and 4 for the definite integral, such that it looked like
-3mC*(integrate fr. 0 to 4)2 ds.
5. Jul 14, 2007
### Staff: Mentor
Realize that the field is constant here, so no real integration is needed. The work done on the charge by the field is just F*d = Eqd. The work done will equal the change in KE of the charge. (Note that the work done by the field is just the negative of the change in PE.) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9488755464553833, "perplexity": 315.2885232508257}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560279468.17/warc/CC-MAIN-20170116095119-00455-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://lists.libreplanet.org/archive/html/auctex-devel/2015-06/msg00032.html | auctex-devel
[Top][All Lists]
## Re: [AUCTeX-devel] exam class, automatically labels and refs
From: Uwe Brauer Subject: Re: [AUCTeX-devel] exam class, automatically labels and refs Date: Sat, 13 Jun 2015 10:12:10 +0200 User-agent: Gnus/5.13001 (Ma Gnus v0.10) XEmacs/21.5-b34 (linux)
> Uwe Brauer <address@hidden> writes:
> Hi Uwe,
> I don't see what's the problem. I just tested it and the labels are
> added as expected so that I can add \refs with C-c ).
That is maybe a misunderstanding,
- automatically inserted: when I type LaTeX-section I obtain
automatically without doing anything
\section{this}
\label{sec:this}.
I don't type this label.
When I do LaTeX-environment I obtain again automatically
$$\label{eq:minimal:1}$$ (minimal is the name of the file). So I want
a similar functionality for «\titledquestion» and «\question»
- references: when I run reftex-reference I obtain a buffer
(in the case of an equation) like this
1 this
> eq:minimal:1
. \int
1 this
Which allows me to navigate. How can I get this functionality
for the \question \titledquestion?
Uwe | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 1, "x-ck12": 0, "texerror": 0, "math_score": 0.9730480909347534, "perplexity": 26715.996375200062}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141733120.84/warc/CC-MAIN-20201204010410-20201204040410-00346.warc.gz"} |
https://os2-s19.unexploitable.systems/lab/lab4.html | # Extra Lab 4: Preemptive Multitasking¶
• Due: 11:59 pm, Thursday Jun 13, 2019
## Introduction¶
In this lab you will implement preemptive multitasking among multiple simultaneously active user-mode environments.
• In part A, you will add multiprocessor support to JOS, implement round-robin scheduling, and add basic environment management system calls (calls that create and destroy environments, and allocate/map memory).
• In part B, you will implement a Unix-like fork(), which allows a user-mode environment to create copies of itself.
• Finally, in part C you will add support for inter-process communication (IPC), allowing different user-mode environments to communicate and synchronize with each other explicitly. You will also add support for hardware clock interrupts and preemption.
### Getting Started¶
Use Git to commit your Lab 3 source, fetch the latest version of the course repository, and then create a local branch called lab4 based on our lab4 branch, origin/lab4:
$cd ~/jos$ git pull
Already up-to-date.
$git checkout -b lab4 origin/lab4 Branch lab4 set up to track remote branch refs/remotes/origin/lab4. Switched to a new branch "lab4"$ git merge lab3
Merge made by recursive.
...
\$
Lab 4 contains a number of new source files, some of which you should browse before you start:
kern/cpu.h Kernel-private definitions for multiprocessor support kern/mpconfig.c Code to read the multiprocessor configuration kern/lapic.c Kernel code driving the local APIC unit in each processor kern/mpentry.S Assembly-language entry code for non-boot CPUs kern/spinlock.h Kernel-private definitions for spin locks, including the big kernel lock kern/spinlock.c Kernel code implementing spin locks kern/sched.c Code skeleton of the scheduler that you are about to implement
### Lab Requirements¶
This lab is divided into three parts, A, B, and C. We have allocated one week in the schedule for each part.
As before, you will need to do all of the regular exercises described in the lab and provide a writeup that briefly answers to the questions posed in the lab. Place the write-up in a file called answers-lab4.txt in the top level of your repository directory before handing in your work.
## Part A: Multiprocessor Support and Cooperative Multitasking¶
In the first part of this lab, you will first extend JOS to run on a multiprocessor system, and then implement some new JOS kernel system calls to allow user-level environments to create additional new environments. You will also implement cooperative round-robin scheduling, allowing the kernel to switch from one environment to another when the current environment voluntarily relinquishes the CPU (or exits). Later in part C you will implement preemptive scheduling, which allows the kernel to re-take control of the CPU from an environment after a certain time has passed even if the environment does not cooperate.
### Multiprocessor Support¶
We are going to make JOS support “symmetric multiprocessing” (SMP), a multiprocessor model in which all CPUs have equivalent access to system resources such as memory and I/O buses. While all CPUs are functionally identical in SMP, during the boot process they can be classified into two types: the bootstrap processor (BSP) is responsible for initializing the system and for booting the operating system; and the application processors (APs) are activated by the BSP only after the operating system is up and running. Which processor is the BSP is determined by the hardware and the BIOS. Up to this point, all your existing JOS code has been running on the BSP.
In an SMP system, each CPU has an accompanying local APIC (LAPIC) unit. The LAPIC units are responsible for delivering interrupts throughout the system. The LAPIC also provides its connected CPU with a unique identifier. In this lab, we make use of the following basic functionality of the LAPIC unit (in kern/lapic.c):
• Reading the LAPIC identifier (APIC ID) to tell which CPU our code is currently running on (see cpunum()).
• Sending the STARTUP interprocessor interrupt (IPI) from the BSP to the APs to bring up other CPUs (see lapic_startap()).
• In part C, we program LAPIC’s built-in timer to trigger clock interrupts to support preemptive multitasking (see apic_init()).
A processor accesses its LAPIC using memory-mapped I/O (MMIO). In MMIO, a portion of physical memory is hardwired to the registers of some I/O devices, so the same load/store instructions typically used to access memory can be used to access device registers. You’ve already seen one IO hole at physical address 0xA0000 (we use this to write to the VGA display buffer). The LAPIC lives in a hole starting at physical address 0xFE000000 (32MB short of 4GB), so it’s too high for us to access using our usual direct map at KERNBASE. The JOS virtual memory map leaves a 4MB gap at MMIOBASE so we have a place to map devices like this. Since later labs introduce more MMIO regions, you’ll write a simple function to allocate space from this region and map device memory to it.
Note
Exercise 1. Implement mmio_map_region() in kern/pmap.c. To see how this is used, look at the beginning of lapic_init() in kern/lapic.c. You’ll have to do the next exercise, too, before the tests for mmio_map_region() will run.
## Application Processor Bootstrap¶
Before booting up APs, the BSP should first collect information about the multiprocessor system, such as the total number of CPUs, their APIC IDs and the MMIO address of the LAPIC unit. The mp_init() function in kern/mpconfig.c retrieves this information by reading the MP configuration table that resides in the BIOS’s region of memory.
The boot_aps() function (in kern/init.c) drives the AP bootstrap process. APs start in real mode, much like how the bootloader started in boot/boot.S, so boot_aps() copies the AP entry code (kern/mpentry.S) to a memory location that is addressable in the real mode. Unlike with the bootloader, we have some control over where the AP will start executing code; we copy the entry code to 0x7000 (MPENTRY_PADDR), but any unused, page-aligned physical address below 640KB would work.
After that, boot_aps() activates APs one after another, by sending STARTUP IPIs to the LAPIC unit of the corresponding AP, along with an initial CS:IP address at which the AP should start running its entry code (MPENTRY_PADDR in our case). The entry code in kern/mpentry.S is quite similar to that of boot/boot.S. After some brief setup, it puts the AP into protected mode with paging enabled, and then calls the C setup routine mp_main() (also in kern/init.c). boot_aps() waits for the AP to signal a CPU_STARTED flag in cpu_status field of its struct CpuInfo before going on to wake up the next one.
Note
Exercise 2. Read boot_aps() and mp_main() in kern/init.c, and the assembly code in kern/mpentry.S. Make sure you understand the control flow transfer during the bootstrap of APs. Then modify your implementation of page_init() in kern/pmap.c to avoid adding the page at MPENTRY_PADDR to the free list, so that we can safely copy and run AP bootstrap code at that physical address. Your code should pass the updated check_page_free_list() test (but might fail the updated check_kern_pgdir() test, which we will fix soon).
Note
Question 1. Compare kern/mpentry.S side by side with boot/boot.S. Bearing in mind that kern/mpentry.S is compiled and linked to run above KERNBASE just like everything else in the kernel, what is the purpose of macro MPBOOTPHYS? Why is it necessary in kern/mpentry.S but not in boot/boot.S? In other words, what could go wrong if it were omitted in kern/mpentry.S? Hint: recall the differences between the link address and the load address that we have discussed in Lab 1.
## Per-CPU State and Initialization¶
When writing a multiprocessor OS, it is important to distinguish between per-CPU state that is private to each processor, and global state that the whole system shares. kern/cpu.h defines most of the per-CPU state, including struct CpuInfo, which stores per-CPU variables. cpunum() always returns the ID of the CPU that calls it, which can be used as an index into arrays like cpus. Alternatively, the macro thiscpu is shorthand for the current CPU’s struct CpuInfo.
Here is the per-CPU state you should be aware of:
• Per-CPU kernel stack. Because multiple CPUs can trap into the kernel simultaneously, we need a separate kernel stack for each processor to prevent them from interfering with each other’s execution. The array percpu_kstacks[NCPU][KSTKSIZE] reserves space for NCPU’s worth of kernel stacks.
In Lab 2, you mapped the physical memory that bootstack refers to as the BSP’s kernel stack just below KSTACKTOP. Similarly, in this lab, you will map each CPU’s kernel stack into this region with guard pages acting as a buffer between them. CPU 0’s stack will still grow down from KSTACKTOP; CPU 1’s stack will start KSTKGAP bytes below the bottom of CPU 0’s stack, and so on. inc/memlayout.h shows the mapping layout.
• Per-CPU TSS and TSS descriptor. A per-CPU task state segment (TSS) is also needed in order to specify where each CPU’s kernel stack lives. The TSS for CPU i is stored in cpus[i].cpu_ts, and the corresponding TSS descriptor is defined in the GDT entry gdt[(GD_TSS0 >> 3) + i]. The global ts variable defined in kern/trap.c will no longer be useful.
• Per-CPU current environment pointer. Since each CPU can run different user process simultaneously, we redefined the symbol curenv to refer to cpus[cpunum()].cpu_env (or thiscpu->cpu_env), which points to the environment currently executing on the current CPU (the CPU on which the code is running).
• Per-CPU system registers. All registers, including system registers, are private to a CPU. Therefore, instructions that initialize these registers, such as lcr3(), ltr(), lgdt(), lidt(), etc., must be executed once on each CPU. Functions env_init_percpu() and trap_init_percpu() are defined for this purpose.
Note
Exercise 3. Modify mem_init_mp() (in kern/pmap.c) to map per-CPU stacks starting at KSTACKTOP, as shown in inc/memlayout.h. The size of each stack is KSTKSIZE bytes plus KSTKGAP bytes of unmapped guard pages. Your code should pass the new check in check_kern_pgdir().
Note
Exercise 4. The code in trap_init_percpu() (kern/trap.c) initializes the TSS and TSS descriptor for the BSP. It worked in Lab 3, but is incorrect when running on other CPUs. Change the code so that it can work on all CPUs. (Note: your new code should not use the global ts variable any more.)
When you finish the above exercises, run JOS in QEMU with 4 CPUs using make qemu CPUS=4 (or make qemu-nox CPUS=4), you should see output like this:
...
Physical memory: 66556K available, base = 640K, extended = 65532K
check_page_alloc() succeeded!
check_page() succeeded!
check_kern_pgdir() succeeded!
check_page_installed_pgdir() succeeded!
SMP: CPU 0 found 4 CPU(s)
enabled interrupts: 1 2
SMP: CPU 1 starting
SMP: CPU 2 starting
SMP: CPU 3 starting
## Locking¶
Our current code spins after initializing the AP in mp_main(). Before letting the AP get any further, we need to first address race conditions when multiple CPUs run kernel code simultaneously. The simplest way to achieve this is to use a big kernel lock. The big kernel lock is a single global lock that is held whenever an environment enters kernel mode, and is released when the environment returns to user mode. In this model, environments in user mode can run concurrently on any available CPUs, but no more than one environment can run in kernel mode; any other environments that try to enter kernel mode are forced to wait.
kern/spinlock.h declares the big kernel lock, namely kernel_lock. It also provides lock_kernel() and unlock_kernel(), shortcuts to acquire and release the lock. You should apply the big kernel lock at four locations:
• In i386_init(), acquire the lock before the BSP wakes up the other CPUs.
• In mp_main(), acquire the lock after initializing the AP, and then call sched_yield() to start running environments on this AP.
• In trap(), acquire the lock when trapped from user mode. To determine whether a trap happened in user mode or in kernel mode, check the low bits of the tf_cs.
• In env_run(), release the lock right before switching to user mode. Do not do that too early or too late, otherwise you will experience races or deadlocks.
Note
Exercise 5. Apply the big kernel lock as described above, by calling lock_kernel() and unlock_kernel() at the proper locations.
How to test if your locking is correct? You can’t at this moment! But you will be able to after you implement the scheduler in the next exercise.
Note
Question 2. It seems that using the big kernel lock guarantees that only one CPU can run the kernel code at a time. Why do we still need separate kernel stacks for each CPU? Describe a scenario in which using a shared kernel stack will go wrong, even with the protection of the big kernel lock.
Note
Challenge! The big kernel lock is simple and easy to use. Nevertheless, it eliminates all concurrency in kernel mode. Most modern operating systems use different locks to protect different parts of their shared state, an approach called fine-grained locking. Fine-grained locking can increase performance significantly, but is more difficult to implement and error-prone. If you are brave enough, drop the big kernel lock and embrace concurrency in JOS!
It is up to you to decide the locking granularity (the amount of data that a lock protects). As a hint, you may consider using spin locks to ensure exclusive access to these shared components in the JOS kernel: 1) The page allocator; 2) The console driver; 3) The scheduler; 4) The inter-process communication (IPC) state that you will implement in the part C.
### Round-Robin Scheduling¶
Your next task in this lab is to change the JOS kernel so that it can alternate between multiple environments in “round-robin” fashion. Round-robin scheduling in JOS works as follows:
• The function sched_yield() in the new kern/sched.c is responsible for selecting a new environment to run. It searches sequentially through the envs[] array in circular fashion, starting just after the previously running environment (or at the beginning of the array if there was no previously running environment), picks the first environment it finds with a status of ENV_RUNNABLE (see inc/env.h), and calls env_run() to jump into that environment.
• sched_yield() must never run the same environment on two CPUs at the same time. It can tell that an environment is currently running on some CPU (possibly the current CPU) because that environment’s status will be ENV_RUNNING.
• We have implemented a new system call for you, sys_yield(), which user environments can call to invoke the kernel’s sched_yield() function and thereby voluntarily give up the CPU to a different environment.
Note
Exercise 6. Implement round-robin scheduling in sched_yield() as described above. Don’t forget to modify syscall() to dispatch sys_yield().
Make sure to invoke sched_yield() in mp_main.
Modify kern/init.c to create three (or more!) environments that all run the program user/yield.c.
Run make qemu. You should see the environments switch back and forth between each other five times before terminating, like below.
Test also with several CPUS: make qemu CPUS=2.
...
Hello, I am environment 00001000.
Hello, I am environment 00001001.
Hello, I am environment 00001002.
Back in environment 00001000, iteration 0.
Back in environment 00001001, iteration 0.
Back in environment 00001002, iteration 0.
Back in environment 00001000, iteration 1.
Back in environment 00001001, iteration 1.
Back in environment 00001002, iteration 1.
...
After the yield programs exit, there will be no runnable environment in the system, the scheduler should invoke the JOS kernel monitor. If any of this does not happen, then fix your code before proceeding.
If you use CPUS=1 at this point, all environments should successfully run. Setting CPUS larger than 1 at this time may result in a general protection or kernel page fault once there are no more runnable environments due to unhandled timer interrupts (which we will fix below!).
Note
Question 3. In your implementation of env_run() you should have called lcr3(). Before and after the call to lcr3(), your code makes references (at least it should) to the variable e, the argument to env_run. Upon loading the %cr3 register, the addressing context used by the MMU is instantly changed. But a virtual address (namely e) has meaning relative to a given address context–the address context specifies the physical address to which the virtual address maps. Why can the pointer e be dereferenced both before and after the addressing switch?
4. Whenever the kernel switches from one environment to another, it must ensure the old environment’s registers are saved so they can be restored properly later. Why? Where does this happen?
Note
Challenge! Add a less trivial scheduling policy to the kernel, such as a fixed-priority scheduler that allows each environment to be assigned a priority and ensures that higher-priority environments are always chosen in preference to lower-priority environments. If you’re feeling really adventurous, try implementing a Unix-style adjustable-priority scheduler or even a lottery or stride scheduler. (Look up “lottery scheduling” and “stride scheduling” in Google.)
Write a test program or two that verifies that your scheduling algorithm is working correctly (i.e., the right environments get run in the right order). It may be easier to write these test programs once you have implemented fork() and IPC in parts B and C of this lab.
Note
Challenge! The JOS kernel currently does not allow applications to use the x86 processor’s x87 floating-point unit (FPU), MMX instructions, or Streaming SIMD Extensions (SSE). Extend the Env structure to provide a save area for the processor’s floating point state, and extend the context switching code to save and restore this state properly when switching from one environment to another. The FXSAVE and FXRSTOR instructions may be useful, but note that these are not in the old i386 user’s manual because they were introduced in more recent processors. Write a user-level test program that does something cool with floating-point.
### System Calls for Environment Creation¶
Although your kernel is now capable of running and switching between multiple user-level environments, it is still limited to running environments that the kernel initially set up. You will now implement the necessary JOS system calls to allow user environments to create and start other new user environments.
Unix provides the fork() system call as its process creation primitive. Unix fork() copies the entire address space of calling process (the parent) to create a new process (the child). The only differences between the two observable from user space are their process IDs and parent process IDs (as returned by getpid and getppid). In the parent, fork() returns the child’s process ID, while in the child, fork() returns 0. By default, each process gets its own private address space, and neither process’s modifications to memory are visible to the other.
You will provide a different, more primitive set of JOS system calls for creating new user-mode environments. With these system calls you will be able to implement a Unix-like fork() entirely in user space, in addition to other styles of environment creation. The new system calls you will write for JOS are as follows:
• sys_exofork:
This system call creates a new environment with an almost blank slate: nothing is mapped in the user portion of its address space, and it is not runnable. The new environment will have the same register state as the parent environment at the time of the sys_exofork call. In the parent, sys_exofork will return the envid_t of the newly created environment (or a negative error code if the environment allocation failed). In the child, however, it will return 0. (Since the child starts out marked as not runnable, sys_exofork will not actually return in the child until the parent has explicitly allowed this by marking the child runnable using….)
• sys_env_set_status:
Sets the status of a specified environment to ENV_RUNNABLE or ENV_NOT_RUNNABLE. This system call is typically used to mark a new environment ready to run, once its address space and register state has been fully initialized.
• sys_page_alloc:
Allocates a page of physical memory and maps it at a given virtual address in a given environment’s address space.
• sys_page_map:
Copy a page mapping (not the contents of a page!) from one environment’s address space to another, leaving a memory sharing arrangement in place so that the new and the old mappings both refer to the same page of physical memory.
• sys_page_unmap:
Unmap a page mapped at a given virtual address in a given environment.
For all of the system calls above that accept environment IDs, the JOS kernel supports the convention that a value of 0 means “the current environment.” This convention is implemented by envid2env() in kern/env.c.
We have provided a very primitive implementation of a Unix-like fork() in the test program user/dumbfork.c. This test program uses the above system calls to create and run a child environment with a copy of its own address space. The two environments then switch back and forth using sys_yield as in the previous exercise. The parent exits after 10 iterations, whereas the child exits after 20.
Note
Exercise 7. Implement the system calls described above in kern/syscall.c. You will need to use various functions in kern/pmap.c and kern/env.c, particularly envid2env(). For now, whenever you call envid2env(), pass 1 in the checkperm parameter. Be sure you check for any invalid system call arguments, returning -E_INVAL in that case. Test your JOS kernel with user/dumbfork and make sure it works before proceeding.
Note
Challenge! Add the additional system calls necessary to read all of the vital state of an existing environment as well as set it up. Then implement a user mode program that forks off a child environment, runs it for a while (e.g., a few iterations of sys_yield()), then takes a complete snapshot or checkpoint of the child environment, runs the child for a while longer, and finally restores the child environment to the state it was in at the checkpoint and continues it from there. Thus, you are effectively “replaying” the execution of the child environment from an intermediate state. Make the child environment perform some interaction with the user using sys_cgetc() or readline() so that the user can view and mutate its internal state, and verify that with your checkpoint/restart you can give the child environment a case of selective amnesia, making it “forget” everything that happened beyond a certain point.
This completes Part A of the lab; check it using make grade and push your work as lab4-a. If you are trying to figure out why a particular test case is failing, run ./grade-lab4 -v, which will show you the output of the kernel builds and QEMU runs for each test, until a test fails. When a test fails, the script will stop, and then you can inspect jos.out to see what the kernel actually printed.
## Part B: Copy-on-Write Fork¶
As mentioned earlier, Unix provides the fork() system call as its primary process creation primitive. The fork() system call copies the address space of the calling process (the parent) to create a new process (the child).
xv6 Unix implements fork() by copying all data from the parent’s pages into new pages allocated for the child. This is essentially the same approach that dumbfork() takes. The copying of the parent’s address space into the child is the most expensive part of the fork() operation.
However, a call to fork() is frequently followed almost immediately by a call to exec() in the child process, which replaces the child’s memory with a new program. This is what the the shell typically does, for example. In this case, the time spent copying the parent’s address space is largely wasted, because the child process will use very little of its memory before calling exec().
For this reason, later versions of Unix took advantage of virtual memory hardware to allow the parent and child to share the memory mapped into their respective address spaces until one of the processes actually modifies it. This technique is known as copy-on-write. To do this, on fork() the kernel would copy the address space mappings from the parent to the child instead of the contents of the mapped pages, and at the same time mark the now-shared pages read-only. When one of the two processes tries to write to one of these shared pages, the process takes a page fault. At this point, the Unix kernel realizes that the page was really a “virtual” or “copy-on-write” copy, and so it makes a new, private, writable copy of the page for the faulting process. In this way, the contents of individual pages aren’t actually copied until they are actually written to. This optimization makes a fork() followed by an exec() in the child much cheaper: the child will probably only need to copy one page (the current page of its stack) before it calls exec().
In the next piece of this lab, you will implement a “proper” Unix-like fork() with copy-on-write, as a user space library routine. Implementing fork() and copy-on-write support in user space has the benefit that the kernel remains much simpler and thus more likely to be correct. It also lets individual user-mode programs define their own semantics for fork(). A program that wants a slightly different implementation (for example, the expensive always-copy version like dumbfork(), or one in which the parent and child actually share memory afterward) can easily provide its own.
### User-level page fault handling¶
A user-level copy-on-write fork() needs to know about page faults on write-protected pages, so that’s what you’ll implement first. Copy-on-write is only one of many possible uses for user-level page fault handling.
It’s common to set up an address space so that page faults indicate when some action needs to take place. For example, most Unix kernels initially map only a single page in a new process’s stack region, and allocate and map additional stack pages later “on demand” as the process’s stack consumption increases and causes page faults on stack addresses that are not yet mapped. A typical Unix kernel must keep track of what action to take when a page fault occurs in each region of a process’s space. For example, a fault in the stack region will typically allocate and map new page of physical memory. A fault in the program’s BSS region will typically allocate a new page, fill it with zeroes, and map it. In systems with demand-paged executables, a fault in the text region will read the corresponding page of the binary off of disk and then map it.
This is a lot of information for the kernel to keep track of. Instead of taking the traditional Unix approach, you will decide what to do about each page fault in user space, where bugs are less damaging. This design has the added benefit of allowing programs great flexibility in defining their memory regions; you’ll use user-level page fault handling later for mapping and accessing files on a disk-based file system.
## Setting the Page Fault Handler¶
In order to handle its own page faults, a user environment will need to register a page fault handler entrypoint with the JOS kernel. The user environment registers its page fault entrypoint via the new sys_env_set_pgfault_upcall system call. We have added a new member to the Env structure, env_pgfault_upcall, to record this information.
Note
Exercise 8. Implement the sys_env_set_pgfault_upcall system call. Be sure to enable permission checking when looking up the environment ID of the target environment, since this is a “dangerous” system call.
## Normal and Exception Stacks in User Environments¶
During normal execution, a user environment in JOS will run on the normal user stack: its ESP register starts out pointing at USTACKTOP, and the stack data it pushes resides on the page between USTACKTOP-PGSIZE and USTACKTOP-1 inclusive. When a page fault occurs in user mode, however, the kernel will restart the user environment running a designated user-level page fault handler on a different stack, namely the user exception stack. In essence, we will make the JOS kernel implement automatic “stack switching” on behalf of the user environment, in much the same way that the x86 processor already implements stack switching on behalf of JOS when transferring from user mode to kernel mode!
The JOS user exception stack is also one page in size, and its top is defined to be at virtual address UXSTACKTOP, so the valid bytes of the user exception stack are from UXSTACKTOP-PGSIZE through UXSTACKTOP-1 inclusive. While running on this exception stack, the user-level page fault handler can use JOS’s regular system calls to map new pages or adjust mappings so as to fix whatever problem originally caused the page fault. Then the user-level page fault handler returns, via an assembly language stub, to the faulting code on the original stack.
Each user environment that wants to support user-level page fault handling will need to allocate memory for its own exception stack, using the sys_page_alloc() system call introduced in part A.
## Invoking the User Page Fault Handler¶
You will now need to change the page fault handling code in kern/trap.c to handle page faults from user mode as follows. We will call the state of the user environment at the time of the fault the trap-time state.
If there is no page fault handler registered, the JOS kernel destroys the user environment with a message as before. Otherwise, the kernel sets up a trap frame on the exception stack that looks like a struct UTrapframe from inc/trap.h:
<-- UXSTACKTOP
trap-time esp
trap-time eflags
trap-time eip
trap-time eax start of struct PushRegs
trap-time ecx
trap-time edx
trap-time ebx
trap-time esp
trap-time ebp
trap-time esi
trap-time edi end of struct PushRegs
tf_err (error code)
fault_va <-- %esp when handler is run
The kernel then arranges for the user environment to resume execution with the page fault handler running on the exception stack with this stack frame; you must figure out how to make this happen. The fault_va is the virtual address that caused the page fault.
If the user environment is already running on the user exception stack when an exception occurs, then the page fault handler itself has faulted. In this case, you should start the new stack frame just under the current tf->tf_esp rather than at UXSTACKTOP. You should first push an empty 32-bit word, then a struct UTrapframe.
To test whether tf->tf_esp is already on the user exception stack, check whether it is in the range between UXSTACKTOP-PGSIZE and UXSTACKTOP-1, inclusive.
Note
Exercise 9. Implement the code in page_fault_handler in kern/trap.c required to dispatch page faults to the user-mode handler. Be sure to take appropriate precautions when writing into the exception stack. (What happens if the user environment runs out of space on the exception stack?)
## User-mode Page Fault Entrypoint¶
Next, you need to implement the assembly routine that will take care of calling the C page fault handler and resume execution at the original faulting instruction. This assembly routine is the handler that will be registered with the kernel using sys_env_set_pgfault_upcall().
Note
Exercise 10. Implement the _pgfault_upcall routine in lib/pfentry.S. The interesting part is returning to the original point in the user code that caused the page fault. You’ll return directly there, without going back through the kernel. The hard part is simultaneously switching stacks and re-loading the EIP.
Finally, you need to implement the C user library side of the user-level page fault handling mechanism.
Note
Exercise 11. Finish set_pgfault_handler() in lib/pgfault.c.
## Testing¶
Run user/faultread (make run-faultread). You should see:
...
[00000000] new env 00001000
[00001000] user fault va 00000000 ip 0080003a
TRAP frame ...
[00001000] free env 00001000
Run user/faultdie. You should see:
...
[00000000] new env 00001000
i faulted at va deadbeef, err 6
[00001000] exiting gracefully
[00001000] free env 00001000
Run user/faultalloc. You should see:
...
[00000000] new env 00001000
fault deadbeef
this string was faulted in at deadbeef
fault cafebffe
fault cafec000
this string was faulted in at cafebffe
[00001000] exiting gracefully
[00001000] free env 00001000
If you see only the first “this string” line, it means you are not handling recursive page faults properly.
Run user/faultallocbad. You should see:
...
[00000000] new env 00001000
[00001000] user_mem_check assertion failure for va deadbeef
[00001000] free env 00001000
Make sure you understand why user/faultalloc and user/faultallocbad behave differently.
Note
Challenge! Extend your kernel so that not only page faults, but all types of processor exceptions that code running in user space can generate, can be redirected to a user-mode exception handler. Write user-mode test programs to test user-mode handling of various exceptions such as divide-by-zero, general protection fault, and illegal opcode.
### Implementing Copy-on-Write Fork¶
You now have the kernel facilities to implement copy-on-write fork() entirely in user space.
We have provided a skeleton for your fork() in lib/fork.c. Like dumbfork(), fork() should create a new environment, then scan through the parent environment’s entire address space and set up corresponding page mappings in the child. The key difference is that, while dumbfork() copied pages, fork() will initially only copy page mappings. fork() will copy each page only when one of the environments tries to write it.
The basic control flow for fork() is as follows:
1. The parent installs pgfault() as the C-level page fault handler, using the set_pgfault_handler() function you implemented above.
2. The parent calls sys_exofork() to create a child environment.
3. For each writable or copy-on-write page in its address space below UTOP, the parent calls duppage, which should map the page copy-on-write into the address space of the child and then remap the page copy-on-write in its own address space. duppage sets both PTEs so that the page is not writeable, and to contain PTE_COW in the “avail” field to distinguish copy-on-write pages from genuine read-only pages.
The exception stack is not remapped this way, however. Instead you need to allocate a fresh page in the child for the exception stack. Since the page fault handler will be doing the actual copying and the page fault handler runs on the exception stack, the exception stack cannot be made copy-on-write: who would copy it?
fork() also needs to handle pages that are present, but not writable or copy-on-write.
4. The parent sets the user page fault entrypoint for the child to look like its own.
5. The child is now ready to run, so the parent marks it runnable.
Each time one of the environments writes a copy-on-write page that it hasn’t yet written, it will take a page fault. Here’s the control flow for the user page fault handler:
1. The kernel propagates the page fault to _pgfault_upcall, which calls fork()’s pgfault() handler.
2. pgfault() checks that the fault is a write (check for FEC_WR in the error code) and that the PTE for the page is marked PTE_COW. If not, panic.
3. pgfault() allocates a new page mapped at a temporary location and copies the contents of the faulting page into it. Then the fault handler maps the new page at the appropriate address with read/write permissions, in place of the old read-only mapping.
The user-level lib/fork.c code must consult the environment’s page tables for several of the operations above (e.g., that the PTE for a page is marked PTE_COW). The kernel maps the environment’s page tables at UVPT exactly for this purpose. It uses a clever mapping trick to make it to make it easy to lookup PTEs for user code. lib/entry.S sets up uvpt and uvpd so that you can easily lookup page-table information in lib/fork.c.
Note
Exercise 12. Implement fork, duppage and pgfault in lib/fork.c.
Test your code with the forktree program. It should produce the following messages, with interspersed ‘new env’, ‘free env’, and ‘exiting gracefully’ messages. The messages may not appear in this order, and the environment IDs may be different.
1000: I am ''
1001: I am '0'
2000: I am '00'
2001: I am '000'
1002: I am '1'
3000: I am '11'
3001: I am '10'
4000: I am '100'
1003: I am '01'
5000: I am '010'
4001: I am '011'
2002: I am '110'
1004: I am '001'
1005: I am '111'
1006: I am '101'
Note
Challenge! Implement a shared-memory fork() called sfork(). This version should have the parent and child share all their memory pages (so writes in one environment appear in the other) except for pages in the stack area, which should be treated in the usual copy-on-write manner. Modify user/forktree.c to use sfork() instead of regular fork(). Also, once you have finished implementing IPC in part C, use your sfork() to run user/pingpongs. You will have to find a new way to provide the functionality of the global thisenv pointer.
Note
Challenge! Your implementation of fork makes a huge number of system calls. On the x86, switching into the kernel using interrupts has non-trivial cost. Augment the system call interface so that it is possible to send a batch of system calls at once. Then change fork to use this interface.
How much faster is your new fork?
You can answer this (roughly) by using analytical arguments to estimate how much of an improvement batching system calls will make to the performance of your fork: How expensive is an int 0x30 instruction? How many times do you execute int 0x30 in your fork? Is accessing the TSS stack switch also expensive? And so on…
Alternatively, you can boot your kernel on real hardware and really benchmark your code. See the RDTSC (read time-stamp counter) instruction, defined in the IA32 manual, which counts the number of clock cycles that have elapsed since the last processor reset. QEMU doesn’t emulate this instruction faithfully (it can either count the number of virtual instructions executed or use the host TSC, neither of which reflects the number of cycles a real CPU would require).
This ends part B. As usual, you can grade your submission with make grade and push your commit tagged with lab4-b.
## Part C: Preemptive Multitasking and Inter-Process communication (IPC)¶
In the final part of lab 4 you will modify the kernel to preempt uncooperative environments and to allow environments to pass messages to each other explicitly.
### Clock Interrupts and Preemption¶
Run the user/spin test program. This test program forks off a child environment, which simply spins forever in a tight loop once it receives control of the CPU. Neither the parent environment nor the kernel ever regains the CPU. This is obviously not an ideal situation in terms of protecting the system from bugs or malicious code in user-mode environments, because any user-mode environment can bring the whole system to a halt simply by getting into an infinite loop and never giving back the CPU. In order to allow the kernel to preempt a running environment, forcefully retaking control of the CPU from it, we must extend the JOS kernel to support external hardware interrupts from the clock hardware.
## Interrupt discipline¶
External interrupts (i.e., device interrupts) are referred to as IRQs. There are 16 possible IRQs, numbered 0 through 15. The mapping from IRQ number to IDT entry is not fixed. pic_init in picirq.c maps IRQs 0-15 to IDT entries IRQ_OFFSET through IRQ_OFFSET+15.
In inc/trap.h, IRQ_OFFSET is defined to be decimal 32. Thus the IDT entries 32-47 correspond to the IRQs 0-15. For example, the clock interrupt is IRQ 0. Thus, IDT[IRQ_OFFSET+0] (i.e., IDT[32]) contains the address of the clock’s interrupt handler routine in the kernel. This IRQ_OFFSET is chosen so that the device interrupts do not overlap with the processor exceptions, which could obviously cause confusion. (In fact, in the early days of PCs running MS-DOS, the IRQ_OFFSET effectively was zero, which indeed caused massive confusion between handling hardware interrupts and handling processor exceptions!)
In JOS, we make a key simplification compared to xv6 Unix. External device interrupts are always disabled when in the kernel (and, like xv6, enabled when in user space). External interrupts are controlled by the FL_IF flag bit of the %eflags register (see inc/mmu.h). When this bit is set, external interrupts are enabled. While the bit can be modified in several ways, because of our simplification, we will handle it solely through the process of saving and restoring %eflags register as we enter and leave user mode.
You will have to ensure that the FL_IF flag is set in user environments when they run so that when an interrupt arrives, it gets passed through to the processor and handled by your interrupt code. Otherwise, interrupts are masked, or ignored until interrupts are re-enabled. We masked interrupts with the very first instruction of the bootloader, and so far we have never gotten around to re-enabling them.
Note
Exercise 13. Modify kern/trapentry.S and kern/trap.c to initialize the appropriate entries in the IDT and provide handlers for IRQs 0 through 15. Then modify the code in env_alloc() in kern/env.c to ensure that user environments are always run with interrupts enabled.
The processor never pushes an error code or checks the Descriptor Privilege Level (DPL) of the IDT entry when invoking a hardware interrupt handler. You might want to re-read section 9.2 of the 80386 Reference Manual, or section 5.8 of the IA-32 Intel Architecture Software Developer’s Manual, Volume 3, at this time.
When you finish this exercise, please do not forget to remove a comment in the kern/sched.c:
// LAB 4:
// Uncomment the following line after completing exercise 13
//”sti”
After doing this exercise, if you run your kernel with any test program that runs for a non-trivial length of time (e.g., spin), you should see the kernel print trap frames for hardware interrupts. While interrupts are now enabled in the processor, JOS isn’t yet handling them, so you should see it misattribute each interrupt to the currently running user environment and destroy it. Eventually it should run out of environments to destroy and drop into the monitor.
## Handling Clock Interrupts¶
In the user/spin program, after the child environment was first run, it just spun in a loop, and the kernel never got control back. We need to program the hardware to generate clock interrupts periodically, which will force control back to the kernel where we can switch control to a different user environment.
The calls to lapic_init and pic_init (from i386_init in init.c), which we have written for you, set up the clock and the interrupt controller to generate interrupts. You now need to write the code to handle these interrupts.
Note
Exercise 14. Modify the kernel’s trap_dispatch() function so that it calls sched_yield() to find and run a different environment whenever a clock interrupt takes place.
You should now be able to get the user/spin test to work: the parent environment should fork off the child, sys_yield() to it a couple times but in each case regain control of the CPU after one time slice, and finally kill the child environment and terminate gracefully.
This is a great time to do some regression testing. Make sure that you haven’t broken any earlier part of that lab that used to work (e.g. forktree) by enabling interrupts. Also, try running with multiple CPUs using make CPUS=2 target. You should also be able to pass stresssched now. Run make grade to see for sure. You should now get a total score of 65/75 points on this lab.
### Inter-Process communication (IPC)¶
(Technically in JOS this is “inter-environment communication” or “IEC”, but everyone else calls it IPC, so we’ll use the standard term.)
We’ve been focusing on the isolation aspects of the operating system, the ways it provides the illusion that each program has a machine all to itself. Another important service of an operating system is to allow programs to communicate with each other when they want to. It can be quite powerful to let programs interact with other programs. The Unix pipe model is the canonical example.
There are many models for interprocess communication. Even today there are still debates about which models are best. We won’t get into that debate. Instead, we’ll implement a simple IPC mechanism and then try it out.
## IPC in JOS¶
You will implement a few additional JOS kernel system calls that collectively provide a simple interprocess communication mechanism. You will implement two system calls, sys_ipc_recv and sys_ipc_try_send. Then you will implement two library wrappers ipc_recv and ipc_send.
The “messages” that user environments can send to each other using JOS’s IPC mechanism consist of two components: a single 32-bit value, and optionally a single page mapping. Allowing environments to pass page mappings in messages provides an efficient way to transfer more data than will fit into a single 32-bit integer, and also allows environments to set up shared memory arrangements easily.
## Sending and Receiving Messages¶
To receive a message, an environment calls sys_ipc_recv. This system call de-schedules the current environment and does not run it again until a message has been received. When an environment is waiting to receive a message, any other environment can send it a message - not just a particular environment, and not just environments that have a parent/child arrangement with the receiving environment. In other words, the permission checking that you implemented in Part A will not apply to IPC, because the IPC system calls are carefully designed so as to be “safe”: an environment cannot cause another environment to malfunction simply by sending it messages (unless the target environment is also buggy).
To try to send a value, an environment calls sys_ipc_try_send with both the receiver’s environment id and the value to be sent. If the named environment is actually receiving (it has called sys_ipc_recv and not gotten a value yet), then the send delivers the message and returns 0. Otherwise the send returns -E_IPC_NOT_RECV to indicate that the target environment is not currently expecting to receive a value.
A library function ipc_recv in user space will take care of calling sys_ipc_recv and then looking up the information about the received values in the current environment’s struct Env.
Similarly, a library function ipc_send will take care of repeatedly calling sys_ipc_try_send until the send succeeds.
## Transferring Pages¶
When an environment calls sys_ipc_recv with a valid dstva parameter (below UTOP), the environment is stating that it is willing to receive a page mapping. If the sender sends a page, then that page should be mapped at dstva in the receiver’s address space. If the receiver already had a page mapped at dstva, then that previous page is unmapped.
When an environment calls sys_ipc_try_send with a valid srcva (below UTOP), it means the sender wants to send the page currently mapped at srcva to the receiver, with permissions perm. After a successful IPC, the sender keeps its original mapping for the page at srcva in its address space, but the receiver also obtains a mapping for this same physical page at the dstva originally specified by the receiver, in the receiver’s address space. As a result this page becomes shared between the sender and receiver.
If either the sender or the receiver does not indicate that a page should be transferred, then no page is transferred. After any IPC the kernel sets the new field env_ipc_perm in the receiver’s Env structure to the permissions of the page received, or zero if no page was received.
## Implementing IPC¶
Note
Exercise 15. Implement sys_ipc_recv and sys_ipc_try_send in kern/syscall.c. Read the comments on both before implementing them, since they have to work together. When you call envid2env in these routines, you should set the checkperm flag to 0, meaning that any environment is allowed to send IPC messages to any other environment, and the kernel does no special permission checking other than verifying that the target envid is valid.
Then implement the ipc_recv and ipc_send functions in lib/ipc.c.
Use the user/pingpong and user/primes functions to test your IPC mechanism. user/primes will generate for each prime number a new environment until JOS runs out of environments. You might find it interesting to read user/primes.c to see all the forking and IPC going on behind the scenes.
Note
Challenge! Why does ipc_send have to loop? Change the system call interface so it doesn’t have to. Make sure you can handle multiple environments trying to send to one environment at the same time.
Note
Challenge! The prime sieve is only one neat use of message passing between a large number of concurrent programs. Read C. A. R. Hoare, Communicating Sequential Processes, Communications of the ACM 21(8) (August 1978), 666-667, and implement the matrix multiplication example.
Note
Challenge! One of the most impressive examples of the power of message passing is Doug McIlroy’s power series calculator, described in M. Douglas McIlroy, Squinting at Power Series, *Software–Practice and Experience*, 20(7) (July 1990), 661-683. Implement his power series calculator and compute the power series for sin(x+x^3).
Note
Challenge! Make JOS’s IPC mechanism more efficient by applying some of the techniques from Liedtke’s paper, Improving IPC by Kernel Design, or any other tricks you may think of. Feel free to modify the kernel’s system call API for this purpose, as long as your code is backwards compatible with what our grading scripts expect.
This ends part C. Make sure you pass all of the make grade tests and don’t forget to write up your answers to the questions in answers-lab4.txt.
Before handing in, use git status and git diff to examine your changes and don’t forget to git add answers-lab4.txt. When you’re ready, commit your changes with git commit -am ‘my solutions to lab 4’, then make handin and follow the directions. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2445976734161377, "perplexity": 3570.788019894426}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964362999.66/warc/CC-MAIN-20211204154554-20211204184554-00161.warc.gz"} |
http://math.stackexchange.com/questions/901051/functional-notation | # Functional Notation.
I have some doubts regarding function notation:
First If I present a function I write:$f(x)$
If I write it's inverse:$f^{-1}(x)$
So why doesn't$f(f(x))=f^2(x)$
Second If $\frac{df(x)}{dx}=f'(x)$ and $\frac{d^2f(x)}{dx^2}=f''(x)$.
So how do you write probably $\frac{d^nf(x)}{dx^n}=f'(x)$.
Does like this:$f'''^{\cdots\text{n times}}(x)$?
Third What difference between $f^n(x),f(x)^n\text{ and }(f(x))^n$
-
The $n$th derivative is often written as $f^{\left(n\right)}\left(x\right)$. $f^2(x)$ is interpreted as $f(x)\times f(x)$ so is not used to denote the function $f\circ f$. – drhab Aug 17 '14 at 14:08
Though I will note that the usage whereby $f^2:=f\circ f$ becomes more common in fields like set theory, where iterates of functions come up a lot and numerical multiplication doesn't make sense. It's good to be aware of this usage. – Malice Vidrine Aug 17 '14 at 14:30
Note that there is an ambiguity. $f^{-1}$ denotes the inverse with respect to the $f\circ g$ operation. However, $f^2$ is ambiguous. It conventionally indication multiplication ($\times$) only when used with $\sin$ and such. – I like Serena Aug 17 '14 at 15:23
Sometimes people write $f^{\circ n}$ for f composed with itself n times. Related: math.stackexchange.com/questions/588875/… – Myself Aug 17 '14 at 19:32
I have some doubts regarding function notation:
First If I present a function I write: $f(x)$
If I write it's inverse: $f^{-1}(x)$
So why doesn't $f(f(x))=f^2(x)$
This is indeed ambiguous. Unfortunately $f^n$ is sometimes used to refer to the $n$-th iterate of a function and other times is commonly used to refer to the $n$-th exponentiation. The same notation was adopted by different branches of mathematics to mean different things and both persist in using it so. Thus when ever you see $f^2$, you should check the context to determine if the author meant the composition $f\circ f$ or the product $f\cdot f$.
More confusingly, the convention that $f^{-1}$ means the iterate inverse of a function has become the standard even when $f^n$ is otherwise used for exponentiation.
Some mathematicians adopt the notation $f^{\circ n}$ to be clear that they mean the $n$ iterate.
Second If $\frac{df(x)}{dx}=f'(x)$ and $\frac{d^2f(x)}{dx^2}=f''(x)$.
So how do you write probably $\frac{d^nf(x)}{dx^n}=f'(x)$.
Does like this:$f'''^{\cdots\text{n times}}(x)$?
We never go passed three primes. The convention is that $f^{(n)}$ means the $n$-th derivative of a function (with respect to its argument).
Third What difference between $f^n(x),f(x)^n\text{ and }(f(x))^n$
Clarity. $f^n(x)$ is ambiguous; it may mean $f\circ f^{n-1}(x)$ or commonly $f\cdot f^{n-1}$. It is possible that $f(x)^n$ could be parsed as $f(x^n)$. However, $(f(x))^n$ is fairly unambiguous; although it is more chunky.
-
I have never heard of $f(x)^n$ meaning $f(x^n)$... it will almost certainly mean $(f(x))^n$. However, for something like $\sin x^2$, since the parentheses around the argument of $\sin$ may be omitted, it is quite likely to mean $\sin(x^2)$, especially because $\sin^2 x$ is already standard for $(\sin x)^2$. – echinodermata Aug 18 '14 at 3:15
For "$\sin(y+z)^2$", one can't be sure whether the parentheses around the argument of $\sin$ have been omitted ($\sin (x^2) = \sin ((y+z)^2) = \sin (y+z)^2$) or not ($(\sin(x))^2 = (\sin (y+z))^2 = \sin (y+z)^2$). – JiK Aug 18 '14 at 7:21
I've seen some books where after the third prime you start to use roman numbers. – jinawee Aug 18 '14 at 7:54
As an aside: typically, whenever $f^n(x)$ represents $n$ compositions, it is noted explicitly. – anorton Aug 28 '14 at 3:30
It depends on the context and the conventions. Four your second question, people usually write $f^{(n)}$. For your first question, some people actually use $f^2$ as an abbreviation for $f \circ f$, but it's not that common.
-
When writing $f^2(x)$, it normally refers to $f(f(x)$. In general: $$f^n(x) = \overbrace{f(f(\ldots f}^{n \text{ times}}(x))\ldots)\\f(x)^n=(f(x))^n\text{ is f(x) raised to the nth power}$$
You can certainly write $\dfrac{d^nf(x)}{dx}=f''^\ldots(x)$. In general, one would write $\dfrac{d^nf(x)}{dx}=f^{(n)}(x)$.
Although, be aware that the context will often dictate what $f^n(x)$ is.
-
I hope this helps:
$$f^n(x) = f(f^{n-1}(x)) = \underbrace{f(f(f(\cdots f(x))\cdots)}_{n \text{ times}} = \underbrace{(f^\circ f^\circ f^\circ \cdots f)}_{n \text{ times}}(x)$$
$$\frac{d^n}{dx^n}f(x) = f^{(n)}(x)$$
$$(f(x))^n = \underbrace{f(x)·f(x)\ldots f(x)}_{n \text{ times}}$$
As far as I know, there's no such thing as $f(x)^n$ but it might mean $(f(x))^n$
-
First: The inverse function notation has nothing to do with exponentiation, therefore $f(f(x))$ is not written as $f^2(x)$. Note, that sometimes on calculators you might see $\cos^{-1}{}$ which means $\arccos$, NOT $\frac{1}{\cos}$.
Second: For derivatives of order $n \geq 4$, typical notation is $f^{(n)}(x)$
Third: This I am not entirely sure of, but to avoid any confusion, I'd only use $(f(x))^n$.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9373192191123962, "perplexity": 596.9095838668421}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-06/segments/1422115862636.1/warc/CC-MAIN-20150124161102-00048-ip-10-180-212-252.ec2.internal.warc.gz"} |
http://phxmarker.blogspot.com/2015/07/phi-psi-fo-fum-bloch-mans-man-to-git-er.html | ## Friday, July 31, 2015
### Phi, Psi, Fo, Fum, Bloch Man's the Man to Git 'er Done!!!
Bloch Man - Willie the Giant
Bloch Wave Functions are solutions to Schrödinger's equation in a periodic crystal (solid-state work, what I do for a living - analog design and the physics behind the devices). I'm going to look at these next, and phase conjugate equations of this form and do some free-styling and comparing to Dan Winter's work...
$$\Phi\dots\Psi\dots\;fo\dots\;fum\dots$$
The Surfer, OM-IV | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.32351061701774597, "perplexity": 10490.255950618644}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-51/segments/1512948542031.37/warc/CC-MAIN-20171214074533-20171214094533-00065.warc.gz"} |
https://www.altmetric.com/details/35952334/chapter/37682555 | ↓ Skip to main content
# Tensorial methods and renormalization in Group Field Theories
Overview of attention for book
Attention for Chapter 6: Super-Renormalizable $${\mathrm {U}}(1)$$ Models in Four Dimensions
Altmetric Badge
You are seeing a free-to-access but limited selection of the activity Altmetric has collected about this research output. Click here to find out more.
Chapter title Super-Renormalizable $${\mathrm {U}}(1)$$ Models in Four Dimensions 6 Tensorial Methods and Renormalization in Group Field Theories Springer, Cham, January 2014 10.1007/978-3-319-05867-2_6 978-3-31-905866-5, 978-3-31-905867-2 Sylvain Carrozza | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.18010281026363373, "perplexity": 12862.969125351743}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439740929.65/warc/CC-MAIN-20200815154632-20200815184632-00187.warc.gz"} |
https://docs.cryptozoon.io/updates | CryptoZoon
Search…
🔧
# 📍 Big Update - Version 2.0 - August 7th
## Mechanisms
### 🗑 EXP Reset
Because EXP will be recalculated in version 2.0, CryptoZoon chose to reset EXP. We discovered a significant difference in the "rare"s, resulting in the high rares having extremely high EXP scores. However, none of your EXP points will be lost; instead, they will be saved and exchanged for tokens or presents from us.
### 🥚 Only Random eggs
Specifically, the tribe-divided eggs will be removed from the Shop. Players are only allowed to purchase Random Eggs, which will randomly spawn ZOANs of different tribes.
Different Tribes will have different parameters in Training Mode. This modification restricts proactive selections for tribes when Training Mode is activated.
### ☠ Yaki Bosses Information
Yaki The Cyclop
Health: 4,500,000 Combat Fee: 150 ZOON
Yaki The Great Ogre
Health: 8,000,000 Combat Fee: 300 ZOON.
Zoan's damage is calculated according to the formula (Changed):
$Damage = (EXP + 10)* Rare Bonus$
# 📍 Update - August 11th
## Mechanism
### 🔋 Turns Play Storing
If a ZOAN does not participate in Fight Monsters every 4 hours, turns to fight in the next participation will be accumulated up to the maximum of turns within 4 skipped hours.
Examples:
• You have an Epic (Rare 5) ZOAN with 5 turns to Fight Monsters each 4 hours.
• You don't fight for 4 hours to keep your 5 turns. After 4 hours, you receive other 5 turns to Fight Monsters. You have 10 turns in total.
• The maximum number of turn that 1 Epic ZOAN may have in a single participation of Fight Monsters is DOUBLE. Even if you don't battle for the next hours, no turns will be accumulated.
Maximum "Turns Play Storing" in each rare:
• Rare 1 - 2 Turns Play
• Rare 2 - 4 Turns Play
• Rare 3 - 6 Turns Play
• Rare 4 - 8 Turns Play
• Rare 5 - 10 Turns Play
• Rare 6 - 12 Turns Play
### 💸 Early Claim
Activated conditions: There are two times claiming prizes fewer than five days apart.
To avoid overselling and inflation, we have updated the Early Claim function for CryptoZoon's reward system. The game's prizes will be temporarily limited for 5 days to reduce the number of tokens released each day through the Fight Monsters gameplay, although users will still be able to collect them immediately.
The system will activate the "Early Claim" function when the players claim the reward fewer than 5 days following the last claim, the system will trigger the "Early Claim" function. Activating the "Early Claim" function will cost you 15% of the fee. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 1, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2113856077194214, "perplexity": 7354.69863031951}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-21/segments/1652663011588.83/warc/CC-MAIN-20220528000300-20220528030300-00663.warc.gz"} |
https://www.isid.ac.in/~statmath/index.php?module=Preprint&Action=ViewAbs&PreprintId=82 | # Publications and Preprints
Existence of Optimal Markov Solutions for Ergodic Control of Markov Processes
by
Abhay G. Bhatt and Vivek S. Borkar
For the ergodic control problem for a large class of controlled Markov processes in continuous time, existence of an optimal ergodic solution and an optimal, possibly time-inhomogeneous Markov solution, in both cases corresponding to a stationary Markov relaxed control policy, are known separately under suitable conditions (Bhatt and Borkar, 1996). The aim of this article is to refine this result to establish the existence of an optimal time-homogeneous Markov solution. The proof is based upon Krylov's Markov selection procedure.
isid/ms/2004/18 [fulltext] | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8529220223426819, "perplexity": 1060.3513914113764}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-51/segments/1575540529955.67/warc/CC-MAIN-20191211045724-20191211073724-00533.warc.gz"} |
https://dash.harvard.edu/handle/1/7431917 | # Edge and Impurity Response in Two-Dimensional Quantum Antiferromagnets
Title: Edge and Impurity Response in Two-Dimensional Quantum Antiferromagnets Author: Metlitski, Max; Sachdev, Subir Note: Order does not necessarily reflect citation order of authors. Citation: Metlitski, Max, and Subir Sachdev. 2008. Edge and impurity response in two-dimensional quantum antiferromagnets. Physical Review B 78(17): 174410. Full Text & Related Files: 0808.0496v1.pdf (309.9Kb; PDF) Abstract: Motivated by recent Monte Carlo simulations of Höglund and Sandvik (arXiv:0808.0408), we study edge response in square lattice quantum antiferromagnets. We use the $$O(3)$$ nonlinear σ model to compute the decay asymptotics of the staggered magnetization, energy density, and local magnetic susceptibility away from the edge. We find that the total edge susceptibility is negative and diverges logarithmically as the temperature $$T\rightarrow 0$$. We confirm the predictions of the continuum theory by performing a $$1/S$$ expansion of the microscopic Heisenberg model with the edge. We propose a qualitative explanation of the edge dimerization seen in Monte Carlo simulations by a theory of valence-bond-solid correlations in the Néel state. We also discuss the extension of the latter theory to the response of a single nonmagnetic impurity, and its connection to the theory of the deconfined critical point. Published Version: doi://10.1103/PhysRevB.78.174410 Other Sources: http://arxiv.org/abs/0808.0496 Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:7431917 Downloads of this work: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6887816190719604, "perplexity": 2013.828819140532}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-51/segments/1512948521292.23/warc/CC-MAIN-20171213045921-20171213065921-00028.warc.gz"} |
https://www.ias.ac.in/listing/bibliography/jess/BHATLA_R | • BHATLA R
Articles written in Journal of Earth System Science
• Assessment of Met Office Unified Model (UM) quantitative precipitation forecasts during the Indian summer monsoon: Contiguous Rain Area (CRA) approach
The operational medium range rainfall forecasts of the Met Office Unified Model (UM) are evaluated over India using the Contiguous Rainfall Area (CRA) verification technique. In the CRA method, forecast and observed weather systems (defined by a user-specified rain threshold) are objectively matched to estimate location, volume, and pattern errors. In this study, UM rainfall forecasts from nine (2007–2015) Indian monsoon seasons are evaluated against 0.5$^{\circ }\times$ 0.5$^{\circ }$ IMD–NCMRWF gridded observed rainfall over India (6.5$^{\circ }{-}$38.5$^{\circ }$N, 66.5$^{\circ }{-}$100.5$^{\circ }$E). The model forecasts show a wet bias due to excessive number of rainy days particularly of low amounts (<1 mm d$^{-1}$). Verification scores consistently suggest good skill the forecasts at threshold of 10 mm d$^{-1}$, while moderate (poor) skill at thresholds of <20 mm d$^{-1}$ (<40 mm d$^{-1}$). Spatial verification of rainfall forecasts is carried out for 10, 20, 40 and 80 mm d$^{-1}$ CRA thresholds for four sub-regions namely (i) northwest (NW), (ii) southwest (SW), (iii) eastern (E), and (iv) northeast (NE) sub-region. Over the SW sub-region, the forecasts tend to underestimate rain intensity. In the SW region, the forecast events tended to be displaced to the west and southwest of the observed position on an average by about 1$^{\circ }$ distance. Over eastern India (E) forecasts of light (heavy) rainfall events, like 10 mm d$^{-1}$ (20 and 40 mm d$^{-1}$) tend to be displaced to the south on an average by about 1$^{\circ }$ (southeast by 1$-2^{\circ }$). In all four regions, the relative contribution to total error due to displacement increases with increasing CRA threshold. These findings can be useful for forecasters and for model developers with regard to the model systematic errors associated with the monsoon rainfall over different parts of India.
• Monitoring of severe weather events using RGB scheme of INSAT-3D satellite
In this study, real-time analysis of products and information dissemination (RAPID), a web-based quick visualisation and analysis tool for INSAT satellite data on a real-time basis has been introduced for identification of pre-monsoon severe weather events. The tool introduces the next generation weather data access and advanced visualisation. The combination of channels using red–green–blue (RGB) composites of INSAT-3D satellite and its physical significant value contents are presented. The solar reflectance and brightness temperatures (BTs) are the major components of the RGB composite. The solar reflectance component of the shortwave thermal infrared (IR) (1.6 $\mu$m), visible (0.5 $\mu$m) and thermal IR channels (10.8 $\mu$m) representing the cloud microstructure is known as Day Microphysics (DMP) RGB and the BT differences between 10.8, 12.0 and 3.9 $\mu$m is known as Night Microphysics (NMP) RGB. The threshold technique has been developed separately for both the RGB products of the year 2015–2016 and 2016–2017 of March–June, prior to the event (1–3 hr) for the detection of the thunderstorms. A validation analysis was conducted using the Forecast Demonstration Project of Storm Bulletins for pre-monsoon weather systems prepared by the India Meteorological Department and RADAR observations, demonstrating that this approach is extremely useful in recognising the area of convection prior to the occurrence of the events by the RGB thresholds. The validation of these thresholds has been carried out for March–June 2017. Both the RGBs i.e., DMP and NMP have a reasonable agreement with the ground-based observations and RADAR data. This threshold technique yields a very good probability of thunderstorm detection more than 94% and 93% with acceptable false alarm conditions, less than 3% and 5% for DMP and NMP, respectively. Furthermore, the limitations of these RGB products are additionally highlighted, and the future extent of refinement of these products in perspective of a rapid scan strategy is proposed. The threshold techniques are found to be useful for nowcasting application and are being used operationally using the RAPID tool.
• Modulation of active-break spell of Indian summer monsoon by Madden Julian Oscillation
The Madden Julian Oscillation (MJO) is the major fluctuation in tropical weather on weekly to monthly time scale and a major driver of Indian summer monsoon (ISM). In this study, using Indian Meteorological Department (IMD) high resolution daily gridded rainfall data and Wheeler-Hendon MJO indices, the daily rainfall distribution over India associated with various phases of eastward propagating MJO was examined to understand the MJO–monsoon rainfall relationship. The present study reveal that the onset of break and active events over India and the duration of these events are strongly related to the phase and strength of the MJO. The break events were relatively better associated with the strong MJO phases than the active events. About 80% of the break events were found to be set in during the phases 1, 2, 7 and 8 of MJO with maximum during phase 1 (34%). On the other hand, about 58% of the active events were set in during the MJO phases 3–6 with maximum during phase 6 (21%). The results of this study indicate an opportunity for using the real time information and skillful prediction of MJO phases for the extended range prediction of break and active conditions.
• Evolution of extreme rainfall events over Indo-Gangetic plain in changing climate during 1901–2010
Due to climate variability and climate change there is an increase in magnitude and frequency of extreme precipitation events. During the last few decades these extreme rainfall events have been increased in global as well as on regional scale. Our climate is very much affected by the changes in frequency of extreme rainfall events. Particularly, variability of extreme rainfall events has been studied over one of the most valuable Indian region i.e. over Indo-Gangetic plain (IGP). Long term trend in extreme events has been analyzed with the help of IMD classification. The classification is considered for moderate rain (2.5–64.4 mm; category I), heavy rain (64.5–124.4 mm; category II) and very heavy rain (124.5 mm or more; category III) and the categorization of rainfall events is based on daily rainfall for the period 1901–2010 during Indian summer monsoon (JJAS). The significant long term trend in frequency of extreme rainfall events is analyzed using the statistical test. Long term trend analysis shows the significant decreasing trend for categories II and III. However, an increasing rainfall frequency is observed for moderate rainfall events (category I) during the considered period. A significant interannual and inter-decadal fluctuation in rainfall frequency and magnitude were observed over IGP. Events of moderate and heavy rainfall increases during the withdrawal period of Indian summer monsoon, which might contribute in several cases of flood in the region of IGP. In term of distribution and contribution of rainfall in agriculture area categories I and II, rainfall events are more important but changes in rainfall pattern may lead to flood and drought risk over IGP. The policy making decision for disaster risk and food security should be based on spatial as well as temporal variability of rainfall pattern over IGP region.
• Abrupt changes in mean temperature over India during 1901–2010
Since eternity, the Earth’s temperature has varied or fluctuated; it has its cooling and hot timing dependency on its orbital position as well as the isolation received from the Sun. The global climate continues to change rapidly compared to the speed of the natural variations in climate. Therefore, the spatially complete representations of surface climate are required for many purposes in applied sciences. But in recent centuries, the main matter of concern is that Earth’s normal temperature fluctuation is being influenced by some external factors such as enhanced greenhouse gases because of extreme uses of fossil fuels, severe industrialization, advance urbanization, etc. This study presents a comprehensive surface temperature dataset of Climatic Research Unit (CRU) available since 1901 for India, which is used to document significant changes in Indian temperature over ten decades, during winter season (January and February), pre-monsoon (March–May), monsoon (June–September) and post-monsoon (October–December) to examine the patterns and possible effects of global warming. A strong increasing pattern is observed with the fast growing of the development after 1950 which has shown nearly doubled in the last 50 yrs. The mean temperature during winter for the 2000s shows a consistent pattern of warming over the Himalayan region, northwestern and southern India, and a pattern of the warming observed over northeastern India and extending southwestward across central India during post-monsoon.
• Assessment of NEMO simulated surface current with HF radar along Andhra Pradesh coast
Simulating upper layer of Bay of Bengal through three-dimensional ocean circulation models is a challenging task. In this study, the surface current from the Nucleus European Modelling of Ocean (NEMO) based global ocean assimilation system is assessed against the high frequency (HF) radar data along the Andhra Pradesh coast on a daily scale during southwest monsoon 2016. The temporal variation of NEMO simulated surface current with HF radar data shows that the NEMO model captures the zonal current better than the meridional current. Both NEMO and HF radar show that the mean surface current average over latitude (15.8$^{\circ}$–16.3$^{\circ}$N) is westward for zonal surface current and southward for meridional current with maximum at 40–60 km away from the coast. Further, the monthly mean HF radar derived surface current indicates the strong south-westward flow of surface current dominated during July 2016 with speed more than 50 cm/s which is also well simulated by NEMO analysis. It also captures the cold core eddy during 15–25 July 2016 with very small north-eastward shift with respect to HF radar. The scatter plot of collocated surface zonal and meridional current average over the box (81.5–82.5$^{\circ}$E; 15.5–16.5$^{\circ}$N) clearly shows that NEMO analysis has the correlation of more than 0.5 for both zonal and meridional current.
$\bf{Highlights}$
$\bullet$ The simulation of upper layer of Bay of Bengal (BoB) through three dimensional ocean circulation models is a challenging task. In this study, the surface current from the high resolution NEMO based global ocean assimilation system is compared against the observed High Frequency (HF) radar data along the Andhra Pradesh Coast during the southwest monsoon 2016.
$\bullet$ NEMO analysis captures the mean and variability of surface current very well with HF radar. However, it underestimates the mean surface current which may be due to coarser model resolution and complex non-linear processes in the coastal region.
$\bullet$ The strong cold core eddy during 15–25 July 2016 is observed along the coast which is well simulated in NEMO model with small north-eastward shift with respect to HF radar.
$\bullet$ The scatter plot of collocated surface current from NEMO analysis and HF radar data average over the Andhra Pradesh Coast (APCO; 81.5–82.5$^{\circ}$E; 15.5–16.5$^{\circ}$N) clearly shows that NEMO analysis has the correlation of more than 0.5 for surface current.
• # Journal of Earth System Science
Volume 132, 2023
All articles
Continuous Article Publishing mode
• # Editorial Note on Continuous Article Publication
Posted on July 25, 2019 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.605885922908783, "perplexity": 3748.889520965834}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764499697.75/warc/CC-MAIN-20230129012420-20230129042420-00251.warc.gz"} |
https://scoop.eduncle.com/the-operator-d-dx-x-d-dx-1-is-equivalent-to | IIT JAM Follow
June 5, 2020 1:04 pm 30 pts
In this question do we have to do direct multiplication of the operators or something else. Is direct multiplication of operators possible?
• 2 Likes
• Shares
• Ruby negi
option b is correct...
• Chandra dhawan
see attached file it's very helpful for you dear
Chandra dhawan
see
• Dhairya sharma
i hope u get it
• Dhairya sharma
here we have to take an wave function on which this operator is going to be operend | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9407788515090942, "perplexity": 6323.66644374079}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178367949.58/warc/CC-MAIN-20210303230849-20210304020849-00569.warc.gz"} |
https://tex.stackexchange.com/questions/473175/remove-colon-in-captions | # remove colon in captions
Consider this example:
\documentclass{report}
\usepackage{graphicx}
%% \usepackage[latvian]{babel}
%% the dot in "att." will replace ":" as the separator
\begin{document}
\begin{figure}
\includegraphics{example-image-a}
\caption{Case of A.}
\end{figure}
\end{document}
The output is
How can I remove the colon from the caption of the image?
The case is relevant for some languages that have other means of separation (see the commented out lines of code).
I suggest, since att. (with the dot) seems to be an abbreviation, which will be used in cross-references, to use labelsep=space:
\documentclass{report}
\usepackage{graphicx}
\usepackage[latvian]{babel}
\usepackage{caption}
\captionsetup[figure]{labelsep=space}
%% the dot in "att." will replace ":" as the separator
\begin{document}
\begin{figure}
\includegraphics{example-image-a}
\caption{Case of A.}
\end{figure}
\end{document}
With the help of the caption package:
\documentclass{report}
\usepackage{graphicx}
\usepackage[latvian]{babel} | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9852309823036194, "perplexity": 5050.975292858223}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-34/segments/1596439735823.29/warc/CC-MAIN-20200803170210-20200803200210-00276.warc.gz"} |
http://lists.racket-lang.org/users/archive/2012-August/053704.html | # [racket] (where-not ...) in Redex
From: Matthias Felleisen (matthias at ccs.neu.edu) Date: Wed Aug 29 16:28:48 EDT 2012 Previous message: [racket] (where-not ...) in Redex Next message: [racket] (where-not ...) in Redex Messages sorted by: [date] [thread] [subject] [author]
On Aug 26, 2012, at 2:33 PM, Robby Findler wrote:
>
>
> On Sunday, August 26, 2012, Matthias Felleisen wrote:
>
> On Aug 25, 2012, at 10:53 PM, Robby Findler wrote:
>
> > On Thu, Aug 23, 2012 at 8:11 AM, Matthias Felleisen
> > <matthias at ccs.neu.edu> wrote:
> >>
> >> I would almost prefer the use of 'when' for 'where' and the introduction of 'unless'.
> >
> > If we did this, then there could be no judgment-forms name 'when' or
> > 'unless', which makes me think we shouldn't do this.
>
> I don't understand this point at all.
>
>
> See the docs for define-judgement-form and imagine a judgment-form whose name was "unless". You'll notice a conflict in the premise grammar.
I have taken the time to re-read the docs, and you're saying that someone could name a judgment rule 'when' or 'unless' via non-ellipsis-non-hyphen-var. Well, let them use strings if they must use such special names as rule names. For an SOS, I could imagine when_true and when_false as names, and for typing rules I could imagine when_t.
> >> The type setting of 'when' could still use 'where' as the English word (and perhaps we can have a way to override it).
> >>
> >> I am not sure how to type set 'unless' other than by providing a the negative operator as an argument !=
> >
> > Using \neq{} seems right to me.
>
> What if you want \not\in or \not\subtype and such?
>
>
> You can't use where or unless for such things already. Either that or I don't understand you?
>
How would you formulate judgments like this:
|- e -> v
------------------------ when v in Nat & v > 0
|- (foo e bar e_1) -> v[e_1}
-- Matthias
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.racket-lang.org/users/archive/attachments/20120829/7f4c9012/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4373 bytes
Desc: not available
URL: <http://lists.racket-lang.org/users/archive/attachments/20120829/7f4c9012/attachment-0001.p7s>
Posted on the users mailing list. Previous message: [racket] (where-not ...) in Redex Next message: [racket] (where-not ...) in Redex Messages sorted by: [date] [thread] [subject] [author] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8659727573394775, "perplexity": 13280.616715226777}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413558066654.4/warc/CC-MAIN-20141017150106-00377-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://byjus.com/electric-flux-formula/ | Electric Flux Formula
Electric Flux
Electric flux formula is obtained by multiplying the electric field and the component of the area perpendicular to the field. It should be noted that electric flux is defined as the number of electric field lines which are passing through a given area in a unit time. Electric flux has SI units of volt metres (V m), or, equivalently, newton metres squared per coulomb (N m2 C1).
The Formula for Electric Flux
$$\phi=E\, A\, Cos\, \theta$$
Here,
• $$\phi$$ is the electric flux
• E is the electric field
• A is the area, and
• $$\theta$$ is the angle between a perpendicular vector to the area and the electric field
Solved Examples
Example 1:
Calculate the electric flux on a plane of area 1 m2 on which an electric field of 2 V/m crosses with an angle of 30 degrees.
Solution:
Given,
E = 2 V/m
A = 1m2
θ = 30°
From the formula of electric flux,
$$\phi=E\, A\, Cos\, \theta$$ $$\phi=2V/m\times 1m^{2}\times Cos(30°)$$
$$\phi=1\;V\;m$$
Example 2:
Determine the electric flux of a flat square having an area of 10 m2 is a uniform electric field of 8000 N/C passing perpendicular to it.
Solution:
Given,
E= 8000 N/C
A= 10 m2
θ = 0° (since electric field is passing perpendicularly)
So,
Φ = 8000 × 102 × Cos(0°)
$$\phi=8\times\,10^{5}\,N\,m^{2}/C$$
For more Physics formulas, derivations, and other preparation materials, keep visiting BYJU’S – The Learning App. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9631732702255249, "perplexity": 1288.6271161417476}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780057580.39/warc/CC-MAIN-20210924201616-20210924231616-00376.warc.gz"} |
https://www.physicsforums.com/threads/index-notation-summing-a-product-of-3-numbers.887213/ | # I (Index Notation) Summing a product of 3 numbers
1. Sep 29, 2016
### throneoo
I have just begun reading about Einstein's summation convention and it got me thinking..
Is it possible to represent ∑aibici with index notation? Since we are only restricted to use an index twice at most I don't think it's possible to construct it using the standard tensors (Levi Cevita and Kronecker Delta). Levi Cevita doesn't work because it's only non-zero when the indices are all different and Kronecker Delta only connects two tensors, leaving the third one behind. It becomes clearer if I think of them in terms of vectors and matrices.
Last edited: Sep 29, 2016
2. Sep 29, 2016
### stevendaryl
Staff Emeritus
Well, you can introduce a matrix $A_{ijk}$ such that $A_{iii} = 1$ and $A_{ijk} = 0$ if any of the indices differ. Then $\sum_i a_i b_i c_i = A_{ijk} a^i b^j c^k$. The matrix $A_{ijk}$ might not be a very interesting matrix, mathematically.
3. Sep 29, 2016
### throneoo
That's exactly what I thought. I suppose this ad hoc matrix is not common because this type of summation rarely appears in Physics
4. Sep 29, 2016
### stevendaryl
Staff Emeritus
Well, the most common use of the Einstein summation convention is for manipulations of vectors and tensors. For those uses, one-dimensional matrices such as $a^i$, written with a raised index, corresponds to a vector, and $b_j$, with a lowered index, corresponds to a covector (there is a geometric distinction between vectors and covectors, even though people often ignore the distinction when using Cartesian coordinates for the components). Something with more than one index is a tensor. For example, $g_{ij}$ is the metric tensor, which is used to compute the length of a vector:
$|\vec{V}| = \sqrt{g_{ij} V^i V^j}$
But not every matrix of numbers corresponds to a tensor. The reason why is because tensors transform when you change coordinate systems (for example, changing from Cartesian to polar coordinates). If you define $A_{ijk}$ so that in any coordinate system, $A_{iii} =1$ and $A_{ijk} = 0$ when any two indices are different, then $A$ will not be a tensor.
5. Sep 29, 2016
### Orodruin
Staff Emeritus
I would not call $A_{ijk}$ a matrix. Something represented by a matrix generally has two indices (or one in the case of row or column matrices). This would be some sort of multidimensional matrix.
Seen as a tensor, this object would not be an isotropic tensor, i.e., it would have different components in another frame, unlike the Kronecker delta or the permutation symbol (seen as a Cartesian pseudo-tensor). In the same fashion $\sum_i a^i b^i c^i$ is not an invariant under coordinate transformations.
Have something to add?
Draft saved Draft deleted
Similar Discussions: (Index Notation) Summing a product of 3 numbers | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 2, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8924877643585205, "perplexity": 476.46207119139467}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-51/segments/1512948515165.6/warc/CC-MAIN-20171212041010-20171212061010-00405.warc.gz"} |
https://toyotechus.com/emc-electromagnetic-compatibility/toyo-original-emc-products/high-gain-preamplifier/ | # Electromagnetic Compatibility(EMC)
### High gain preamplifier TPA series
TPA series pre-amplifier achieved high gain and low noise figure which are demanded by EMI measurement over 1 GHz.
It is designed by the following specification, and even if it installs in measuring indoor, EMI measurement can be performed by sufficient sensitivity.
Moreover, since this is a small size, it can be also installed the pit in an electric wave darkroom and directly under a receiving antenna.
Limit value and measurement method are stipulated in CISPR (International Special Committee on Radio Interference), FCC rules of USA, MIL standard of US military for the EMI of frequency band more than 1GHz. When measuring frequency more than 1GHz, there is the case that cannot confirm whether it satisfy prescribed limit value because of the big noise figure of the spectrum analyzer, and low gain of the horn antenna. In such case it can be confirmed by inserting TPA series preamp between horn antenna and spectrum analyzer to amplify a noise level.
The TPA series preamp has the following characteristics.
• Low Noise figure
• Good VSWR for Input and Output port
• Radiation of heat with the large-sized heat sink
• By an exclusive AC power supply unit, it can easily supply a power
• Because the size is small, it can be installed in the pit under the floor
Model Name Item Specification TPA0108-40 Operation frequency 1-8GHz Gain 42dB(min) Gain flatness ±1.5dB(max) Noise figure 1.8dB(max) Output power +13dBm(min) VSWR 2:01 Input connector SMA(female) TPA0118-35 Operation frequency 1-18GHz Gain 35dB(min) Gain flatness ±2.75dB(max) Noise figure 2.5dB(max) Output power +13dBm(min) VSWR 2.5：1(max) Input connector SMA(female) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8602723479270935, "perplexity": 8045.369281309776}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195524972.66/warc/CC-MAIN-20190716221441-20190717003441-00490.warc.gz"} |
http://mathhelpforum.com/discrete-math/184102-difine-first-order-formula-positive-numbers-print.html | # Difine a first order formula for positive numbers
• July 5th 2011, 03:11 AM
hmmmm
Difine a first order formula for positive numbers
Let $\mathcal{V}_{ar}={+,.,0,1}$ be the vocabulary of arithmetic. Let R be the structure that has universe $\mathbb{R}$ and interprets the vocabulary in the usual manner.
Define a $\mathcal{V}_{ar}$ formula $\alpha(x)$ such that for any
$a\in\mathbb{R}, R\models\alpha(a)$ if and only if a is positive.
Im sure I really should be able to do this but I cannot think how to.
Thanks for any help
For clarity $R$ is the structure and $\mathbb{R}$ is the real numbers.
(what is the LaTex for the reals?)
Thanks again
• July 5th 2011, 05:42 AM
emakarov
Re: Difine a first order formula for positive numbers
How about $a\ne0\land\exists x\,x\cdot x=a$?
• July 5th 2011, 08:57 AM
hmmmm
Re: Difine a first order formula for positive numbers
haha yeah thanks I was thinking about that for ages! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 8, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9730891585350037, "perplexity": 1027.673491825857}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1419447559962.154/warc/CC-MAIN-20141224185919-00073-ip-10-231-17-201.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/85182/formula-to-convert-1-to-90-2-to-180 | # Formula to convert $1$ to $90$, $2$ to $180$?
If I've got $\sin^{-1}(1)$ or $\sin^{-1}(2)$, how would I convert that to $90^\circ$ and $180^\circ$ ?
I'm trying to convert a graphed version of $f(x) = \sin(x)$ in the domain $0 \leq x \leq 360$ with all intersections of $\sin(x) = 0.371$ from the first intersection being $(0.38,0.371)$ to be $(\text{degree}, 0.371)$
Thank you! Any help is greatly appreciated! :)
-
First note that $\sin^{-1}(2)$ is not possible because $-1 \leq \sin{x} \leq 1$. Next take $y = \sin^{-1}(1) \Rightarrow \sin(y) =1 \Rightarrow y = \frac{\pi}{2}$ as one of the value – user9413 Nov 24 '11 at 10:15
$\arcsin(2)=\frac{\pi}{2}-i\ln(2+\sqrt 3)$ is a complex number, and thus cannot be the same as $180^\circ$. $\arcsin(1)$ will yield either $90^\circ$ or $\pi/2$, depending on the setting of your computing environment. In any event, it is a simple matter to convert radians to degrees. We have the relation $\pi\text{ radians}=180^\circ$. – Ｊ. Ｍ. Nov 24 '11 at 10:16
basically I'm asking how I convert the 1 to 90 and the 2 to 180 in a picture like this :) bbc.co.uk/scotland/learning/bitesize/standard/maths_ii/images/… thank you! – David Nov 24 '11 at 10:18
I see neither a 1 nor a 2 on the axes in the picture you've linked to. – Ｊ. Ｍ. Nov 24 '11 at 10:19
I'm sorry* I meant vice versa* in the event that x=90, how would that be converted to x=1? sorry for the confusion! – David Nov 24 '11 at 10:20
Let me venture a guess.... Since you've stated that $(0.38, 0.371)$ is a point on your graph of $y = \sin x$, your calculating device must be in radians mode. Indeed, $\sin(0.38) = 0.371$. Now the graph you've included as a link in the comments section shows $y = \sin x$ if the angle $x$ is measured in degrees. So when you say you want to convert $(0.38, 0.371)$ to $(degree, 0.371)$, then all you need is the conversion factor, $$\mathrm{Degrees} = \mathrm{Radians} \times \frac{180^{\circ}}{\pi}$$
In particular, $0.38 \times \frac{180^{\circ}}{\pi} \approx 21.77^{\circ}$.
(Note, what is confusing about your post is your mention of $\sin^{-1} 1$ and $\sin^{-1} 2$, which have nothing to do with the rest of the stated question. Moreover, your graph shows the intersections of $y = \sin x$ with the line $y = 0.75$, so did you really mean to ask about the $x$-value(s) when $y = 0.75$?) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9200008511543274, "perplexity": 251.68192193144665}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413507454577.44/warc/CC-MAIN-20141017005734-00335-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://codereview.stackexchange.com/questions/183613/items-derived-from-one-function-are-getting-printed-within-another-for-loop-in-a/183619 | # Items derived from one function are getting printed within another for loop in another function
I have written some code in python to scrape some items from a webpage. There is a link (titling see more) attach to each container. If I click on that link I can reach a certain page where all the information is available. It is quite convenient to track the see more link and parse all documents from there. However, my goal is to parse the first two documents from the first page and going on to the other page (clicking on the see more button) I'll parse the rest. I have tried to do the same as I described just now. It is doing just fine.
At this point, I'm seriously dubious whether the way I'm doing things is the right one or error-prone because I used two items from earlier page to get printed within the newly defined for loop created in the later function. It is giving me the accurate results though. Any suggestion as to what I did here is ideal or any guidance why I should not practice this will be highly appreciated.
This is the site link. This is the full script:
import requests
from urllib.parse import urljoin
from bs4 import BeautifulSoup
soup = BeautifulSoup(res.text,"lxml")
for item in soup.select('.course-list-item'):
date = item.select(".date")[0].text
def parse_more(event_name,ev_date,i_link): ## notice the two items (event_name,ev_date)
soup = BeautifulSoup(res.text,"lxml")
for items in soup.select('.e-loc-cost'):
location = ' '.join([' '.join(item.text.split()) for item in items.select(".event-add")])
cost = ' '.join([' '.join(item.text.split()) for item in items.select(".costs")])
print(event_name,ev_date,location,cost) ##again take a look: I used those two items within this newly created for loop.
if __name__ == '__main__':
glean_items(url)
First of all, usual things (I feel like I'm suggesting these things in most of the web-scraping related discussions):
And, I am not completely sure about the reliability of the .pull_right a selector. At this point, it reads that you want to follow the link that is on the right in its respective container. The position of the element on the screen may easily change with a design change. What about a selector like a[id*=ReadMore] or .more > a?
Also, note that select()[0] could be replaced with select_one().
### Code Style
There is not a lot of things to point out since the code is rather short and straightforward, but there are some PEP8 violations that can be addressed:
Some of the variable names could be more explicit, e.g. event_date in place of ev_date, event_link instead of i_link.
### The improved code
from urllib.parse import urljoin
from bs4 import BeautifulSoup, SoupStrainer
import requests
parse_only = SoupStrainer(class_='course-list-item')
soup = BeautifulSoup(response.text, "lxml", parse_only=parse_only)
for item in soup.select('.course-list-item'):
date = item.select_one(".date").text
parse_only = SoupStrainer(class_="e-loc-cost")
soup = BeautifulSoup(response.text, "lxml", parse_only=parse_only)
for items in soup.select('.e-loc-cost'):
location = ' '.join([' '.join(item.text.split()) for item in items.select(".event-add")])
cost = ' '.join([' '.join(item.text.split()) for item in items.select(".costs")])
print(event_name, event_date, location, cost)
if __name__ == '__main__':
with requests.Session() as session:
glean_items(session, URL)
• I see our recommendations are quite similar :). And I always forget that requests.Session is a context manager... – Graipher Dec 25 '17 at 22:30
• @Graipher ah, nice, quite similar, but good idea to extract the souping into a separate function! :) Happy holidays! – alecxe Dec 25 '17 at 22:35
• Happy holidays to you as well! – Graipher Dec 25 '17 at 22:37
• Thanks for pointing out the fragility of the selector I used above to grab read more links. Your suggested one is much better and consistent. I have a question on this though. There are two classes in it <div class="pull-right more">. How did you become sure which one is generated dynamically and which one is not? Because, instead of pull-right you prefer to go with more. Thanks again @sir alecxe. – MITHU Dec 26 '17 at 10:58
• @Mithu no problem. Sure, my thinking was that "more" in this case is logical - you are following the link to more information about this search result. Thanks. – alecxe Dec 26 '17 at 14:47
1. I would use requests.Session, which allows re-using the connection. This speeds up successive requests (as you are doing here).
2. I would factor out the getting and souping into a function, to be more DRY. This uses the Python 3.x exclusive yield from to consume its argument as an iterator:
def get(session, url, selector):
res = session.get(url)
soup = BeautifulSoup(res.text, "lxml")
yield from soup.select(selector)
1. When you only want the first occurrence of something, you can use select_one(...), instead of select(...)[0], which is slightly more readable (and might even be faster, depending on the implementation).
2. Instead of printing, return/yield the found values and make it the responsibility of the caller to print.
3. You should have a look at Python's official style-guide, PEP8, which you already mostly follow. One thing it recommends, though, is adding a blank after a comma. It also recommends using UPPER_CASE for global constants.
4. You could add docstrings to describe what your functions do.
With (most) of these changes implemented, I get this code:
import requests
from urllib.parse import urljoin
from bs4 import BeautifulSoup
def get(session, url, selector):
res = session.get(url)
soup = BeautifulSoup(res.text, "lxml")
yield from soup.select(selector)
for item in get(session, main_link, '.course-list-item'):
date = item.select_one(".date").text
for items in get(session, link, '.e-loc-cost'):
location = ' '.join([' '.join(item.text.split()) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3844612240791321, "perplexity": 3010.506941598972}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-39/segments/1568514573289.83/warc/CC-MAIN-20190918131429-20190918153429-00173.warc.gz"} |
https://papers.nips.cc/paper/2011/hash/8757150decbd89b0f5442ca3db4d0e0e-Abstract.html | #### Authors
Andrew Guillory, Jeff A. Bilmes
#### Abstract
We propose an online prediction version of submodular set cover with connections to ranking and repeated active learning. In each round, the learning algorithm chooses a sequence of items. The algorithm then receives a monotone submodular function and suffers loss equal to the cover time of the function: the number of items needed, when items are selected in order of the chosen sequence, to achieve a coverage constraint. We develop an online learning algorithm whose loss converges to approximately that of the best sequence in hindsight. Our proposed algorithm is readily extended to a setting where multiple functions are revealed at each round and to bandit and contextual bandit settings. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8612412810325623, "perplexity": 650.0117319119904}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-21/segments/1620243991370.50/warc/CC-MAIN-20210515131024-20210515161024-00069.warc.gz"} |
https://blog.fabian-blechschmidt.de/translate-magento-cookie-notice/ | Thanks to DSGVO some customers want to have a cookie notice:
Magento has this feature already built in. You can turn it on in the backend:
System > Configuration > General > Web > Session Cookie Management > Cookie Restriction Mode: YES
Beside this you can define what the customer sees in the CMS block: cookie_restriction_notice_block.
Magento can have the same cms block identifier for different stores. Unfortunately this doesn't work for this feature.
The reason is:
class Mage_Page_Block_Html_CookieNotice extends Mage_Core_Block_Template
{
$blockIdentifier = Mage::helper('core/cookie')->getCookieRestrictionNoticeCmsBlockIdentifier();$block = Mage::getModel('cms/block')->load($blockIdentifier, 'identifier'); // [...] } } load() doesn't care about the store mapping and takes the first block with the identifier it finds - which is for every store the same. I fixed the problem with a rewrite on the block and replaced the method with: public function getCookieRestrictionBlockContent() {$blockIdentifier = Mage::helper('core/cookie')->getCookieRestrictionNoticeCmsBlockIdentifier();
$block = Mage::getModel('cms/block') // ADDED store filter ->setStoreId(Mage::app()->getStore()->getId()) ->load($blockIdentifier);
$html = ''; if ($block->getIsActive()) {
/* @var $helper Mage_Cms_Helper_Data */$helper = Mage::helper('cms');
$processor =$helper->getBlockTemplateProcessor();
$html =$processor->filter($block->getContent()); } return$html;
} | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5300266146659851, "perplexity": 10322.179817689264}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560627998369.29/warc/CC-MAIN-20190617022938-20190617044938-00121.warc.gz"} |
http://forum.symthic.com/battlefield-1-general-discussion/battlefield-1-cte-discussion/11148-cte-battlefield-roots-initiative/index3.html?s=9fd3d04ed6a3aca1621661d1ed0608b6d2368c53 | Welcome to symthic forums! We would love if you'd register!
You don't have to be expert in bit baking, everyone is more than welcome to join our community.
You are not logged in.
## CTE Battlefield Roots Initiative
Hey! If this is your first visit on symthic.com, also check out our weapon damage charts.
Currently we have charts for Battlefield 3, Call of Duty: Black Ops 2, Medal of Honor: Warfighter and Call of Duty: Modern Warfare 3
Posts: 75
Date of registration
: Sep 17th 2013
Platform: Xbox One
Location: Richmond, VA
Battlelog:
Reputation modifier: 6
Thursday, March 2nd 2017, 8:40am
Well I do hope for a bigger push to diverse squads and not feeling punished for playing medic/support/scout, just because there's a tank in play, which with the light AT grenades and the HE crossbow/rifle grenade I feel like they're working towards.
Can't get a title
Posts: 1,531
Date of registration
: Dec 23rd 2013
Platform: Xbox One
Location: The Land of Multitudinous Kangaroos
Reputation modifier: 13
Thursday, March 2nd 2017, 8:49am
DICE isn't just restricted to changing resupply times. They can still change damage values, reload times, angle modifiers, muzzle velocity, etc.
I have confidence that they can work something out.
Also, I'm seeing a worrying amount of people rejecting the new grenade auto regen idea just because they don't like the idea of having an automatically regenerating gadget.
something something Model 8 bestgun
### Quoted from "Pastafarianism"
Next, wanna try adding a guy that you KNOW is bad, and just testing to see that? Example: PP-2000 (god I so wanna love this gun, and yet...)
### Quoted from "Pastafarianism"
Example: PP-2000 (god I so wanna love this gun, and yet...)
Yes, it comes in last so far, but that is mostly because I'm making it shoot at 100m ADS - Not Moving as one of the criteria. Even then, between 50-100m Not Moving, when you include Useability, it is only 1.37% worse than the MTAR-21. Within 50m then it even beats the A-91.
Have a look, vs. the A-91 Carbine:
Using it with Muzzle Brake and Compensator is a wash in terms of overall performance. Comp is SLIGHTLY more accurate, while MB is SLIGHTLY more easy to use. Their overall scores are basically tied, with MB just ahead. I guess either can be recommended.
### Quoted from "Pastafarianism"
But... You can't be counting for the fact that it takes 9 bullets to kill at "long" range... Don't you dare tell me my A-91 is worse than a 9 BTK 650 RPM mediocre PDW.
Also. Just go heavy barrel. The recoil is low enough.
### Quoted from "Zer0Cod3x"
Well, technically...
Comparing a PP2K with HB and an A-91 with comp and stubby (as you suggested in an earlier post), at 50m not moving, the A-91 is only better by 4 damage per hitrate. While at 75m and 100m, surprisingly the PP2K does better than the A-91 (I'm pretty damn surprised as well).
And 10m and 50m moving the PP2K also does more damage per hitrate than the A-91. At 25m the A-91 is only better by about half a bullet's damage as well.
In addition, the PP2K has a much larger mag size and substantially less recoil. And it looks hella awesome. So comparing the A-91 to a PDW is of some worth after all, as the PP2K is better (technically, not practically) than the A-91.
Mind blown.
### Quoted from "Pastafarianism"
I... I...
*cries in a corner*
### Quoted from "Veritable"
Zer0Cod3x explained it very well. If you look at the raw numbers right here on Symthic Comparison, you can see how that happened:
A-91 vs PP-2000 | BF4 Weapon Comparison | Symthic
A-91's "23%" RPM advantage only afforded it 1 extra round.
Velocities are wash.
V-Recoil are wash (and this is HBar on PP2k vs. A-91 without).
Hipfire and ADS - Moving are better on the PP2k, but it's a PDW and not the surprising part.
The surprising part is that, as equipped (and we see above that PP2k HBar has almost same V-Recoil as A-91 without HBar so why not?), the PDW performs better at 50 - 100m than a bloody Carbine. Why?
SIPS, 42% better on the PP2k.
And here is the most important part. ADS - Not Moving Spread, 0.35 vs. 0.2, 43% improvement.
Without HBar then of course the PP2k loses, which is why when I add all the attachments together for an Overall Ranking, it would slot below the A-91. Run HBar on it, though, then... I'm sorry
### Quoted from "Pastafarianism"
@Veritable
@Zer0Cod3x
I... I...
But...
Wha...
I AM HAVING AN EXISTENTIAL CRISIS IN SCHOOL BECAUSE OF YOU TWO.
FUCK YOU NERDS AND YOUR FANCY NUMBERS
SEXY RUSSIAN BULLPUPS FTW.
In all seriousness, thank you both so much for giving me the numbers. I still don't want to accept them. You have led the horse to water. I still need to drink.
Posts: 75
Date of registration
: Sep 17th 2013
Platform: Xbox One
Location: Richmond, VA
Battlelog:
Reputation modifier: 6
Thursday, March 2nd 2017, 9:12am
Grenade spam alone makes auto regen grenades scary to people, it's less about timers and more about perception as people see that as you just have grenades for staying alive.
Rezmer
Posts: 4,259
Date of registration
: Apr 6th 2012
Platform: PC
Location: From the heart of Europe.
Battlelog:
Reputation modifier: 17
Thursday, March 2nd 2017, 10:22am
Meanwhile on reddit, people freak out because obviously support ammo will be even more useless than it is now.
[Aristocrat's Shoes]
### Quoted from "Darktan13"
TLDR -
Teamwork is where players function by themselves, but their effectiveness is multiplied when they work together. Not a checklist of "did we bring a healer so we can start playing?"
Posts: 2,015
Date of registration
: Jan 12th 2014
Platform: PC
Battlelog:
Reputation modifier: 14
Thursday, March 2nd 2017, 5:53pm
### Quoted from "Zer0Cod3x"
DICE isn't just restricted to changing resupply times. They can still change damage values, reload times, angle modifiers, muzzle velocity, etc.
I have confidence that they can work something out.
Also, I'm seeing a worrying amount of people rejecting the new grenade auto regen idea just because they don't like the idea of having an automatically regenerating gadget.
And I simply don't think that magical fields that buff/debuff damage or weapon performance have any place in a BF game - that's bashing some serious MMO/overwatch shit in. Especially if coupled to un-intuitive/unknown radius of effect. And if you do add indicators or at least HUD indicators for the AOE of magic boxes its just going to be a shitshow on those infamous choke points they are already worried about.
The smokescreen as a damage modifier in BF4 was as pretty janky mechanic for instance. Now it was a powerful ability and great gameplay ability, but it was horribly counterintiutive that smoke magically reduced projectile damage - while BF is an arcade/fantasy game the design/setting really generates the expectation that at least weapons aren't magically modified through somewhat visible magical field projectors. BF1 smoke dishcarger works so, so, so, so much better. It's a straightforward obsucrant and it's amazing because obsucrants on the battlefield are amazing. Good job DICE; make smoke good by making sure it does what smoke should do; make sure you can't be seen so you can't be shot. That's almost too sensible as a mechanic choice.
So why are they now talking about going backwards on that and introducing magic? AEO healing/resupply off boxes is a straightforward mechanic that abstracts something from a fairly concrete concept. Magical fields that modify weapons near them, or bullets passing through them have no concrete/logical basis outside of some far future sci-fi shit which is akin to magic. Really the only exception to said magic is the APS systems, or ERA. And those just shoot down/nullify projectiles in a straightforward manner.
Lets save the magic for BF 2143, where you can throw in all sorts of overwatch/MMO esque shit and buffs/debuffs on the grounds of sci-fi magic. Sci-fi magic is cool. Change the setting and the expectations that derive from the setting also change and you can do more without jankyness.
And remember - all this is to fix an ill posed problem: too much spam in choke points requires that stowage and resupply be reworked. Instead it should be: oh, yeah, chokepoints are bad for a game with lots of AEO things that aren't single life. Ops.
### Quoted from "sid_tai"
I don't think going 5 assaults should be the only viable strategy, but should be equally as viable as 3 assaults + 1 support + 1 medic.
On the effectiveness of rocket gun against tank, the main reeason that it is not effective is because you need to deploy to use it. A lot of times you cannot deploy at a good spot to shoot it, and are forced to shoot it at an angle, causing reduced damage or even ricochet. That is the reason why the rocket gun is not that effective compared to BF3/4 RPG/SMAW. Giving the rocket gun more ammo does not make it more effective, but only would that give people more opportunity to prone and wait for people to come out of a corner and one shot them.
Two shotting a tank to the rear in BF4 required 2 basically square tail shots: IOW, typically happened vs a bad or distracted tank.
The rocket gun isn't bad. It's that the heavier tanks have a deeper health pool since min dmg is 18 and they have e-rep plus lucky ricochets. But they are then bad in other ways. However the health pool vs RG damage means you simply aren't soloing tanks with a ranged weapon anymore. But then unlike BF4 you an every player shooting at the tank can hit in at range because the RG has great ballistics, the tank is slow, and most of them don't have high-uptime anti infantry if they have the high durability.
BF4 is not a good place class balance wise - on maps with a bigger armor pool there was a disproportional number of engineers outside of the bush wookies and C4/jihad smurfs. Decent guns plus anti-stuff launcher. The obvious choice.
BF1 clearly should attempt to avoid a similar situation with the Assault class.
The issue with fighting tanks at range is simply that the best solution is N+1 rocket guns because of the shooting mechanics of the rocket gun. Once you start having lots of assaults (which you usually do) and those assaults all really try to shoot at the tank (which they don't, it's usually groups of 1s and 2s), the RG ammo pool becomes irrelevant because you've got many stowed tank kills spread out in that total assault ammo pool. I really have no idea how they will tweak support passives change that equation without what amounts to some fuckery - by their own admission they have no idea how they will do this either, they just see a problem, IMO where there really isn't one.
Not sure why they are even concerned about the overall viability of the medic in an AT fight. The medic is good at doing what it always does: picking up the mess. Why didn't they add recon in there? So that in their view a squad of 2 assault, 1 med, 1 support, 1 recon should be just as good as fighting a tank as 5 assault. They are basically ignoring what recon and support can already do (mortar + k bullets), and assuming medic needs to do more than what it can already do, which is picking up fallen squaddies after they've been derped by the tank.
This post has been edited 1 times, last edit by "tankmayvin" (Mar 2nd 2017, 11:53pm)
Posts: 292
Date of registration
: Dec 2nd 2013
Platform: PC
Location: California
Battlelog:
Reputation modifier: 10
Thursday, March 2nd 2017, 11:57pm
### Quoted from "NoctyrneSAGA"
• The overall system of resupplies is currently not working as intended. The best squad composition to fight a tank is to bring 5 assault players. 3 assault players combined with a medic and support should beat that, but usually it does not. We want ammo gadgets to matter for all players, no matter how long you stay alive. Ammo should be relevant the moment you spawn in. Medic players are rarely affected by ammo unless they run rifle grenades. However, a support player can currently allow a medic to fire 12 rifle grenades in a row with almost no delay. This should not be possible
Well no shit. When you make AT garbage by having them do less damage and be more cumbersome to use vs BF34 where a single Engineer could make a tank fuck off or outright kill him with two well-placed rear shots, stacking more Assaults is always going to be the better option
Whoever wrote this has no concept of how vehicles are or how they work in BF1. Can we get an actual dev that reworks tanks and vehicles in general to be tools for assisting the team and capturing objectives, not unstoppable raid bosses and infantry farming machines?
Salt Miner
Posts: 3,636
Date of registration
: Mar 19th 2014
Platform: Xbox One
Battlelog:
Reputation modifier: 16
Friday, March 3rd 2017, 12:10am
A Rocket Gun damage buff in exchange for the eventual lower available ammo seems likely.
Also, this is really just the exact same system vehicle ammo has right now.
Who Enjoys, Wins
Posts: 2,015
Date of registration
: Jan 12th 2014
Platform: PC
Battlelog:
Reputation modifier: 14
Friday, March 3rd 2017, 12:37am
### Quoted from "BleedingUranium"
A Rocket Gun damage buff in exchange for the eventual lower available ammo seems likely.
Also, this is really just the exact same system vehicle ammo has right now.
A rocket gun buff (in isolation) would make it more powerful than the 57mm HE, which is kinda dumb. Rocket gun now carries 4 shots, which is 72 min damage vs a heavy (18 min/hit). If you even dropped the ammo count by 1, to keep that same min damage dumping you'd now have to do 24 min damage, which would make it clearly more powerful than the HE 57mm.
Anything that increases the per hit damage of the RG is a clear and heavy buff to the RG since the operator rarely survives to dump 4 shots on a tank. Anything that buffs damage but removes total solo damage is a straight punishment to an assault player who can stay alive since they are not rewarded for doing so.
Really, pinning the RG to the 57mm HE vehicle damage model is a pretty good place balance wise.
Posts: 2,015
Date of registration
: Jan 12th 2014
Platform: PC
Battlelog:
Reputation modifier: 14
Friday, March 3rd 2017, 12:42am
### Quoted from "NoctyrneSAGA"
• The overall system of resupplies is currently not working as intended. The best squad composition to fight a tank is to bring 5 assault players. 3 assault players combined with a medic and support should beat that, but usually it does not. We want ammo gadgets to matter for all players, no matter how long you stay alive. Ammo should be relevant the moment you spawn in. Medic players are rarely affected by ammo unless they run rifle grenades. However, a support player can currently allow a medic to fire 12 rifle grenades in a row with almost no delay. This should not be possible
Well no shit. When you make AT garbage by having them do less damage and be more cumbersome to use vs BF34 where a single Engineer could make a tank fuck off or outright kill him with two well-placed rear shots, stacking more Assaults is always going to be the better option
Whoever wrote this has no concept of how vehicles are or how they work in BF1. Can we get an actual dev that reworks tanks and vehicles in general to be tools for assisting the team and capturing objectives, not unstoppable raid bosses and infantry farming machines?
BF3 tank >> BF4 tank >> BF1 tank.
Two man tank crews with the BF3/BF4 RWS gunner system were simply dramatically more powerful than any combo you can throw together in BF1. One RWS gunner is worth 4-5x any single gunner in BF1.
BF3 ERA just fucking laughed at engineer rockets. You could eat 3 hits without taking health damage.
Posts: 3,292
Date of registration
: Apr 26th 2013
Platform: PS4
Location: Arizona, USA
Reputation modifier: 15
Friday, March 3rd 2017, 1:03am
The problem with the Rocket Gun is the extreme vulnerability to use it. You're lucky to get one shot off on a tank without being picked off by one of the 10 Scouts strewn about the map or just the common cluster of infantry surrounding the tank. And when you do get the shot off it typically does something shitty like 15-17 damage. Oooh, so rewarding.
Now, the overall damage output available against a heavy tank is between 60-80 (depending on the angle) which is fine, but when it is highly unlikely that all four Rockets can be used in a lifetime against a singular tank, then that damage output becomes futile.
Often times when I played Assault, I wouldn't even bother engaging tanks with the Rocket Gun because I knew as soon as I deployed it I'd probably be killed by literally anything because I'm a stationary target. The argument here would be "find better positioning and minimize exposure" which works sometimes but not always. Sometimes there's only a small window of opportunity to inflict damage and deter the tank from engaging and every bit counts to stop a tank from pushing too much where he can really do some damage.
Possible changes here:
1. Reduce reserve rockets to 2 with a minimum damage of 20 and a max of 25 (or 27); a range of 60-75 (or 81) possible damage overall if you can use them all.
2. Reduce reserves to 1, min of 30 - max of max of 40; a range of 60-80 (this one is highly improbable, but it's the other option to retain the maximum damage output we have now).
### Quoted from "tankmayvin"
Rocket gun now carries 4 shots, which is 72 min damage vs a heavy (18 min/hit). If you even dropped the ammo count by 1, to keep that same min damage dumping you'd now have to do 24 min damage, which would make it clearly more powerful than the HE 57mm.
This is completely contrary to my experience with Rocket Gun vs heavies. I've easily done 15 damage (at a bad angle, but still) and a "perfect" hit for 20 or 21.
To Aim Assist or not to Aim Assist, that is the question.
### Source code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
AccelerationInputThreshold 0.98
AccelerationMultiplier 5.0
AccelerationDamping 4.0
AccelerationTimeThreshold 0.15
SquaredAcceleration 0.0
MaxAcceleration::Vec2
x 2.0
y 2.0
YawSpeedStrength 1.0
PitchSpeedStrength 1.0
AttractDistanceFallOffs::Vec2
x 1.0
y 1.2
AttractSoftZone 0.75
AttractUserInputMultiplier 0.45
AttractUserInputMultiplier_NoZoom 0.5
AttractOwnSpeedInfluence 0.0
AttractTargetSpeedInfluence 0.85
AttractOwnRequiredMovementForMaximumAttract 0.0
AttractStartInputThreshold 0.1
AttractMoveInputCap 0.0
AttractYawStrength 1.0
AttractPitchStrength 0.34
MaxToTargetAngle 45.0
MaxToTargetXZAngle 45.0
ViewObstructedKeepTime 0.0
SnapZoomLateralSpeedLimit 1000.0
SnapZoomTime 0.2
SnapZoomPostTimeNoInput 0.2
SnapZoomPostTime 0.2
SnapZoomReticlePointPriority 999
SnapZoomAutoEngageTime 0.0
SnapZoomBreakTimeAtMaxInput 0.2
SnapZoomBreakMaxInput 0.2
SnapZoomBreakMinAngle 90.0
SnapZoomSpamGuardTime 1.2
SoldierBackupSkeletonCollisionData *nullGuid*
CheckBoneCenterOnlyDistance 40.0
### Source code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
AccelerationInputThreshold 0.98
AccelerationMultiplier 5.0
AccelerationDamping 4.0
AccelerationTimeThreshold 0.15
SquaredAcceleration 0.0
MaxAcceleration::Vec2
x 2.0
y 2.0
YawSpeedStrength 1.0
PitchSpeedStrength 1.0
AttractDistanceFallOffs::Vec2
x 1.0
y 1.2
AttractSoftZone 0.0
AttractUserInputMultiplier 1.0
AttractUserInputMultiplier_NoZoom -1.0
AttractOwnSpeedInfluence 0.0
AttractTargetSpeedInfluence 0.0
AttractOwnRequiredMovementForMaximumAttract 0.0
AttractStartInputThreshold 0.0
AttractMoveInputCap 0.0
AttractYawStrength 0.0
AttractPitchStrength 0.0
MaxToTargetAngle 45.0
MaxToTargetXZAngle 45.0
ViewObstructedKeepTime 0.0
SnapZoomLateralSpeedLimit 1000.0
SnapZoomTime 0.2
SnapZoomPostTimeNoInput 0.0
SnapZoomPostTime 0.0
SnapZoomReticlePointPriority 999
SnapZoomAutoEngageTime 0.0
SnapZoomBreakTimeAtMaxInput -1.0
SnapZoomBreakMaxInput 0.2
SnapZoomBreakMinAngle 90.0
SnapZoomSpamGuardTime 0.5
SoldierBackupSkeletonCollisionData *nullGuid*
CheckBoneCenterOnlyDistance 40.0
DisableForcedTargetRecalcDistance 7.0
### Source code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
AccelerationInputThreshold 0.98
AccelerationMultiplier 5.0
AccelerationDamping 4.0
AccelerationTimeThreshold 0.15
SquaredAcceleration 0.0
MaxAcceleration::Vec2
x 2.0
y 2.0
YawSpeedStrength 1.0
PitchSpeedStrength 1.0
AttractDistanceFallOffs::Vec2
x 1.0
y 1.2
AttractSoftZone 0.75
AttractUserInputMultiplier 0.45
AttractUserInputMultiplier_NoZoom 0.5
AttractOwnSpeedInfluence 0.0
AttractTargetSpeedInfluence 0.85
AttractOwnRequiredMovementForMaximumAttract 0.0
AttractStartInputThreshold 0.1
AttractMoveInputCap 0.0
AttractYawStrength 1.0
AttractPitchStrength 0.34
MaxToTargetAngle 45.0
MaxToTargetXZAngle 45.0
ViewObstructedKeepTime 0.0
SnapZoomLateralSpeedLimit 1000.0
SnapZoomTime 0.2
SnapZoomPostTimeNoInput 0.0
SnapZoomPostTime 0.0
SnapZoomReticlePointPriority 999
SnapZoomAutoEngageTime 0.0
SnapZoomBreakTimeAtMaxInput -1.0
SnapZoomBreakMaxInput 0.2
SnapZoomBreakMinAngle 90.0
SnapZoomSpamGuardTime 0.5
SoldierBackupSkeletonCollisionData *nullGuid*
CheckBoneCenterOnlyDistance 40.0
DisableForcedTargetRecalcDistance 7.0 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.30077606439590454, "perplexity": 7624.235019317081}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-43/segments/1539583514708.24/warc/CC-MAIN-20181022050544-20181022072044-00238.warc.gz"} |
https://www.physicsforums.com/threads/maximum-deceleration-of-a-bicycle.723451/ | # Maximum Deceleration of a Bicycle
1. Nov 18, 2013
### Kaevan807
1. The problem statement, all variables and given/known data
I'm only trying to answer the maximum deceleration possible question, not the rest.
2. Relevant equations
Not really sure which equations are applicable, I know the Maximum deceleration of a body in general will be a = μ*g.
Although I would think that moments need to be taken into account for this question.
3. The attempt at a solution
I've had two trains of though with this question, the first was just assuming that between using both breaks, the maximum deceleration possible could be achieved and so we get:
a = (9.81*0.8) = 7.848 m/s2
Not a very engineering solution though and I know it's probably not the correct solution.
I would try to do it with moments, calculating the friction using each and both of the breaks, and then take moments about the axle of the front wheel, but I'm missing measurements to allow me to get these moments.
I know the maximum acceleration with the front break only is given by a = g* (distance from COM to front wheel/ height of COM).
i.e. a = (9.81 * (0.635/1.143)) = 5.45 m/s2
2. Nov 18, 2013
### tiny-tim
Hi Kaevan807!
If we ignore tipping, the maximum deceleration comes from the maximum friction force, which is µ(Nfront + Nrear).
(and if both wheels are braking, then N = mg)
And tipping will occur when Nrear = 0.
(alternatively, use the non-inertial frame of reference in which the bicycle is stationary …
then there are two forces on the bicycle: mg vertically down, and ma horizontally forward, making an "effective weight" of the combination of them …
tipping will happen when that weight misses the wheelbase)
3. Nov 18, 2013
### Kaevan807
So does that mean I was right and that the maximum deceleration will be μ*g?
Or did I just completely misread what you just said?
4. Nov 18, 2013
### tiny-tim
"If we ignore tipping", yes
5. Nov 18, 2013
### Kaevan807
By tipping I presume you mean over the handlebars rather than to the side?
How do I calculate the maximum deceleration without ignoring tipping then?
6. Nov 18, 2013
### tiny-tim
yes
Tipping will occur when Nrear = 0.
(which you can find from τ = Iα)
7. Nov 18, 2013
### Kaevan807
Just getting more and more confused :P I understand tipping occurs when Nrear = 0, but what is T in that equation?
I is the moment of inertia right? But how do I calculate the moment of inertia of a bicycle? (Moments of inertia really aren't my strong point)
And how do I calculate the angular acceleration? ( which is what alpha is right?)
Just so I get this right though, assuming that Nrear is just = 0, (i.e. That point where we're using maximum breaking force on the front wheel only without tipping) that would mean that we're breaking with the front wheel only, in which case, I know how to calculate the maximum deceleration with just that wheel.
Would I be right in assuming that any breaking force which equates to a front wheel only deceleration less than that value would not cause tipping? And therefore would allow for full breaking power on the read wheel as well?
(Not really sure how I'd calculate that, but just want to get my head around where I'm going with this)
8. Nov 18, 2013
### tiny-tim
τ (tau) is the total torque
When it starts to tip, α = 0
(and now i'm off to bed :zzz:)
9. Nov 19, 2013
### Kaevan807
But if α = 0, then surely τ = 0? Which tells me what? Is there some equation that all of that goes into? Really don't get where I'm supposed to be going with this question
10. Nov 19, 2013
### tiny-tim
sorry, my late-at-night oversimplification
τ = dLtotal/dt = d/dt (Ic.o.mω + Lc.o.m),
where Lc.o.m is the angular momentum of the whole mass m as if it were concentrated at the centre of mass
that τ equals the moment of the weight plus the moment of Nrear
now set Nrear = 0 and α = 0
11. Nov 19, 2013
### Kaevan807
Sorry, still very confused..
First off, why are we calculating Torque?
Torque is a measure of how much a force causes an object to rotate right? So it makes more sense to calculate Torque than moments?
Where are we taking the Torque about? The object will rotate about the axle of the front wheel presumably? So where does this come into the equation?
Is ω in the equation the same as $\alpha$?
Looking through the link you put in, most of the formulae contain a velocity v, which we don't have, a mass m, which we don't have and a position vector r, which, relative to the axle of the front wheel, we only have an x-component for? I can see how you could leave some of these as constants, but I don't understand how you can go from Torque to Deceleration in the first place?
Thanks for taking the time to reply, and sorry that it's taking me so long to come to grips with this, some parts of mechanics I find really easy but this stuff trips me up a bit.
12. Nov 19, 2013
### tiny-tim
torque and moment (of force) are the same thing
no, it will tip about the bottom of the front wheel (the instantaneous centre of rotation)
we can take moments (torques), and use τ = dL/dt, about any stationary point, or about a moving point provided
i] it is the centre of mass
ii] it is the instantaneous centre of rotation, and the the instantaneous centre of rotation is moving in a straight line parallel to the centre of mass
sorry, no, i'm using the standard notation α = dω/dt = d2θ/dt2
m will cancel
v you don't need, because you only need dv/dt (a), which you can find from µN = ma
(and you do have the y-component, since it's the bottom, not the axle)
13. Nov 19, 2013
### Kaevan807
Finally got a chance to meet up with my lecturer today, who said that Max deceleration occurs when the front brake only is applied and the back wheel just comes off the ground, i.e. The equation that I have at the start.
Didn't realise that it tipped about the bottom of the front wheel which made everything make more sense. Thanks for the help.
Draft saved Draft deleted
Similar Discussions: Maximum Deceleration of a Bicycle | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8825482726097107, "perplexity": 1069.2635841622678}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187826840.85/warc/CC-MAIN-20171023221059-20171024001059-00463.warc.gz"} |
https://wikieducator.org/User:Sanjaypandagale/Social_Philosophy_of_Dr._B._R._Ambedkar | # Social Philosophy of Dr. B. R. Ambedkar
The Father of Indian Constitution Dr. B. R. Ambedkar
Bhodisatva Dr. B. R. Ambedkar
## ****EDUCATE, UNITE AND AGITATE****
According to B. R. Ambedkar, “Society is always composed of Classes. Their basis may differ. They may be economic or intellectual or social, but an individual in a society is always a member of a class. This is a universal fact and early Hindu society could not have been an exception to this rule, and, as a matter of fact, we know it was not. So what was the class that first to make itself into the caste, for class and caste, so to say, are next door neighbors, and it is only the span that separates the two. A Caste is an Enclosed class.[1]
Regarding the origin of Caste, B. R. Ambedkar said that, “The study of the origin of caste must furnish us with an answer to the question-What is the class that raised this “enclosure” around itself? The customs in question were current in the Hindu society. These customs in on their strictness are obtainable only in one caste, namely the Brahmins, who occupy the highest place in the social hierarchy of the Hindu society; and as their prevalence in non-Brahmin castes is derivative of their observance are neither strict nor complete. If the prevalence of these customs in the non-Brahmin castes is derivative then it needs no argument to prove that which class is the father of the institution of caste. The strict observance of these customs and the social superiority arrogated by the priestly class in all ancient civilization are sufficient to prove that they were the originators of this “unnatural institution” founded and maintained through these unnatural means.”[2]
This feature of class is common with other societies also. About the classes present in Hindu society Ambedkar said that, “the Hindu society, in common with other societies was composed of classes and the earliest known are the {1} Brahmins or the priestly class; {2} The Kshatriya, or the military class and {3} The Vaishya, or the merchant class and {4} The Shudra, or the artisan menial class. Particular attention has to be paid to the fact that this was essentially a class system, in which individuals, when qualified, could change their class, and therefore classes did change their personnel. At some times in the history of the Hindus, the priestly class socially detached itself from the rest of the body of people and through a closed door policy became a caste by itself. The other classes being subject to the law of social division of labour underwent differentiation, some into large, other into very minute groups. The Vaishya and Shudra classes were the original inchoate plasm, which formed the sources of the numerous castes of today. As the military occupation does not very easily lend itself to very minute sub–division, the Kshatriya class could have differentiated into soldiers and administrators.”[3]
About sub-division of society he further added that, “This sub-division of a society is quite natural. But the unnatural thing about these sub-divisions is that they have lost the open-door character of the class system and have become self-enclosed units called castes. The question is: were they compelled to close their doors and become endogamous, or did they close them of their own accord? I submit that there is a double line of answer: Some closed the door: Other found it closed against them. The one is a psychological interpretation and the other is mechanistic, but they are complementary and both are necessary to explain the phenomena of caste-formation in its entirety.”[4]
So this is the brief history of castes in India. But were there any harms of this caste system? It is very important to find out the answer of this question. As above mentioned there were mainly four classes present in India. In the course of time, one new class, the fifth class, emerged from the shudra class, that was Ati-shudra or Dalits, which was lower in status than the fourth Varna. The people under the fourth Varna, known as Shudras, were sufficiently degraded in the religious books; one can imagine the situation of the people who were another step below the Shudras. That is why the Dalits have another name called, “Outcaste or Untouchables.” Dalits were deprived of the basic human rights, the right to education, and their degraded position was sanctified by the religious law books. Here are two verses from the texts of the Hindu religion: Now if a Sudra listens intentionally to (a recitation of) the Veda, his ears shall be filled with (molten) tin or lac. (Gautam Dharma Sutra 12.4). Vedas were the first religious books of the Hindus. Hindus, or Brahmins to be precise, declared Vedas as divine and hence infallible. Another verse is: If a Sudra recites (Vedic text), his tongue shall be cut out.[5]
On the pathetic condition of untouchables Ambedkar had given lot of facts. He writes that , “Under the rule of the Peshwas in the Maratha country the untouchables was not allowed to use the public street if a Hindu was coming along lest he should pollute the Hindu by his shadow. The untouchable was required to have a black thread either on his wrist or on in his neck as a sign or a mark to prevent the Hindus from getting them polluted by his touch through mistake. In Poona, the capital of the Peshwa, the untouchables was required to carry, strung from his waist, a broom to sweep away from behind the dust he treaded on lest a Hindu walking on the same should be polluted. In Poona the untouchable was required to carry an earthen pot, hung in his neck wherever he went, for holding his spit falling on earth should pollute a Hindu who might unknowingly happen to tread on it.”[6] The children of untouchables were not allowed to study in public school. Untouchables were not allowed to use public wells, to wear apparel or ornaments they like and to eat any food they like. The list of atrocities is even longer than this. In post-independent India, this list is lessen but not completely exhausted.
Very few social reformers fought against this unnatural institutions and atrocities. Mahatma Jyotirao Phule, Savitribai Phule, Chhatrapati Shahu Maharaj, Periyar E. V. Ramaswamy and B. R. Ambedkar were main of them. Ambedkar asserts that caste is not based on division of labour. It is division of labourers. As an economic organization also, caste is a harmful institution. He calls upon the Hindus to annihilate the caste which is a great hindrance to social solidarity and to set up a new social order based on the ideals of liberty, equality and fraternity in consonance with the principles of Democracy. He advocates inter-caste marriage as one of the solutions to the problem. But he stresses that the belief in the ‘shastras’ is the root cause of maintaining castes. He therefore suggests, “make every man and woman free from the thralldom of the ‘shastras’, cleanse their mind of the pernicious notions founded on the ‘shastras’ and he or she will interdine and intermarry”. According to him, the society must be based on reason and not on atrocious traditions of caste system.
From the above deliberation it is clear that the Caste is a close system and Class is an open system. Education can lead an individual to move from Caste to Class, i.e; from close system to open system. In Caste system, an individual is confined only to his or her traditional occupation. So, there is a little scope to grow. But in Class, as it is open, an individual can grow as per his or her capability. And only education can bring this change. Ambedkar had also given lot of emphasis on getting education. He said that, “Educate, Organize and Agitate”. Here he had given prime importance to education. He further added that, “The backward classes have come to realize that after all education is the greatest material benefit for which they can fight. We may forego material benefits of civilization but we cannot forego our rights and opportunities to reap the benefits of the highest education to the fullest extent. That the importance of this question from the point of view of the backward classes who have just realized that without education their existence is not safe.” He suffered a lot due to this caste system. Still in that system of discrimination, he succeeded to well educate himself.
## Notes
1. Moon, Vasant (Comp), Dr. Babasaheb Ambedkar Writing and Speeches, Vol. 1, p. 15, Bombay: The Education Department, Government of Maharashtra, (1979).
2. Moon, Vasant (Comp), Dr. Babasaheb Ambedkar Writing and Speeches, Vol. 1, p. 15, Bombay: The Education Department, Government of Maharashtra, (1979).
3. Ibid., p. 18
4. Ibid., p. 18
5. Gautam Dharma Sutra 12.5
6. Ibid., p. 39
## Author
### Mr. Sanjay Kumar Pandagale,
Lecturer in Education,
Regional Institute of Education,
Shyamla Hills, Bhopal
Mr. SANJAY KUMAR PANDAGALE opaparaja@yahoo.co.in sanju.rie@indiatimes.com
Cite error: <ref> tags exist, but no <references/> tag was found | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2722979187965393, "perplexity": 4434.028261147512}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-40/segments/1664030335491.4/warc/CC-MAIN-20220930145518-20220930175518-00101.warc.gz"} |
https://en.wikipedia.org/wiki/331_model | # 331 model
The 331 model is an extension of the electroweak gauge symmetry from ${\displaystyle SU(2)_{W}\times U(1)_{Y}}$ to ${\displaystyle SU(3)_{L}\times U(1)_{X}}$ with ${\displaystyle SU(2)_{W}\subset SU(3)_{W}}$ and the hypercharge ${\displaystyle Y=\beta T_{8}+IX}$ and the electric charge ${\displaystyle Q=Y/2+T_{3}/2}$ where T3 and T8 are the Gell-Mann matrices of SU(3)L and β and I are parameters of the model. The name 331 comes from the full gauge symmetry group ${\displaystyle SU(3)_{C}\times SU(3)_{L}\times U(1)_{X}}$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 6, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8983750939369202, "perplexity": 190.39530981102226}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-26/segments/1498128320582.2/warc/CC-MAIN-20170625203122-20170625223122-00227.warc.gz"} |
https://boyet.com/blog/generating-permutations-with-heap-rsquo-s-algorithm/ | ## Generating permutations with Heap’s algorithm
This evening I wanted to solve a particular problem, and it required me – or so I thought – to permute an array of items. Back in the day I wrote an article for PCPlus on the subject and mentioned in there Heap’s algorithm. I hasten to add here that “Heap” here is not the traditional computer science heap, or even the application memory heap, but B.R. Heap, who first formulated and published this algorithm in 1963 (pdf).
Permutation 1: we're out
Wikipedia has a small article on Heap’s algorithm (although Heap’s paper is not that difficult to read – it even has flow charts!), and even gives some pseudo-code for it:
procedure generate(n : integer, A : array of any):
if n = 1 then
output(A)
else
for i := 1; i ≤ n; i += 1 do
generate(n - 1, A)
if n is odd then
j ← 1
else
j ← i
swap(A[j], A[n])
The problem with this pseudo-code is that, although it looks simple enough, there is no discussion as to whether the array A is zero-based or one-based. Some perusal will lead you to assume that it is, in fact, one-based (that is, the first element is at position 1, and if there are n elements, the last element is at position n). Fair enough, but of course, I’m sure that most of my readers are firmly in the zero-based camp in real life, as am I. How do you change it to cater for those types of arrays? There are a couple of answers, I suppose.
The first one is to keep the pseudo-code pretty much as is. Notice though that the only time the elements of the array are referenced is in the call to the swap function, so the simplest answer is to rewrite that to something like this:
procedure swap(x, y : integer, A : array of any):
temp = A[x - 1]
A[x - 1] = A[y - 1]
A[y - 1] = temp
and then you just call it with the two indexes j and n and the array, and let the routine do its stuff taking care of the array being zero-based.
Permutation 2: we're asleep
Of course, the second one is to rewrite it completely to assume zero-based arrays. Here’s a JavaScript example where I chuck away the variable n and call it what it really is: the index of the last item you are permuting up to:
var generatePermutations = function (items, process) {
"use strict";
var generate = function (last, items, process) {
var
i,
swap = function (x, y) {
var temp = items[x];
items[x] = items[y];
items[y] = temp;
};
if (last === 0) {
process(items);
}
else {
if ((last & 1) !== 1) {
for (i = 0; i <= last; i += 1) {
generate(last - 1, items, process);
swap(0, last);
}
}
else {
for (i = 0; i <= last; i += 1) {
generate(last - 1, items, process);
swap(i, last);
}
}
}
};
generate(items.length - 1, items, process);
};
generatePermutations(['a', 'b', 'c', 'd'], function (items) {
console.log(items.join(""));
});
Notice that I wrapped Heap’s algorithm in a function that you actually call, so you don’t have to remember that you don’t pass in the number of items, just the index of the last item.
UPDATE (9-Jul-2015):
I’ve been having a chat with the author of the Wikipedia piece – it seems the pseudo-code I’d copied and inserted above is not correct. Be warned! There’s been a couple of changes to that pseudo-code in the interim on their page, so I recommend nipping over to Wikipedia to review the latest, rather than me copying it here.
Anyway, in going back over my notes for that, I discovered that my JavaScript code was doing one too many swaps per call of the inner function. (In essence, I threw in some calls to console.log() to analyze the recursion – yay for sophisticated debugging!.) So I made a small change to the routine. Here’s the new one:
var generatePermutations = function (items, process) {
"use strict";
var generate = function (last, items, process) {
var
i,
swap = function (x, y) {
//console.log(x + " <=> " + y);
var temp = items[x];
items[x] = items[y];
items[y] = temp;
};
//console.log(last);
if (last === 0) {
process(items);
}
else {
// if last is even
if ((last & 1) !== 1) {
for (i = 0; i < last; i += 1) {
generate(last - 1, items, process);
swap(0, last);
}
}
// else last is odd
else {
for (i = 0; i < last; i += 1) {
generate(last - 1, items, process);
swap(i, last);
}
}
generate(last - 1, items, process);
}
};
generate(items.length - 1, items, process);
};
generatePermutations(['a', 'b', 'c', 'd'], function (items) {
console.log(items.join(""));
});
Notice I left in the state-of-the-art debugging statements (albeit commented out) just for you. You’re welcome.
Now playing:
Spandau Ballet - Round and Round
(from The Singles Collection)
Loading links to posts on similar topics...
#### 4 Responses
##### #1bluss said...
08-Jul-15 9:58 AM
Hi, the wikipedia article had an error in its pseudocode. As you can see in the text, the algorithm should use exactly one swap between each permutation. I've updated the article and illustration to correct this, but by now the error is all over the internet! Hope this helps and let's enjoy how much more beautiful the algorithm is without extra swaps.
##### #2bluss said...
08-Jul-15 10:00 AM
Oh, I see your javascript version already corrects this. Excellent!
##### #3julian m bucknall said...
08-Jul-15 10:37 AM
@bluss: Thanks for taking the time to read my post! Although I quoted the Wikipedia article and the pseudo-code there, I think I actually based my JavaScript code more on Heap's discussion in his paper instead. So, maybe that's why I managed to correct the original issue :)
Cheers, Julian
##### #4Akinwale Habib said...
06-Aug-17 3:47 PM
Great write up. I find your article easy to understand and detailed.
##### Leave a response
Note: some MarkDown is allowed, but HTML is not. Expand to show what's available.
• Emphasize with italics: surround word with underscores _emphasis_
• Emphasize strongly: surround word with double-asterisks **strong**
• Link: surround text with square brackets, url with parentheses [text](url)
• Inline code: surround text with backticks IEnumerable
• Unordered list: start each line with an asterisk, space * an item
• Ordered list: start each line with a digit, period, space 1. an item
• Insert code block: start each line with four spaces
• Insert blockquote: start each line with right-angle-bracket, space > Now is the time... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.35054054856300354, "perplexity": 3527.260471707667}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-06/segments/1674764500035.14/warc/CC-MAIN-20230202165041-20230202195041-00392.warc.gz"} |
http://mathhelpforum.com/pre-calculus/196473-logaithm-help.html | # Thread: logaithm help.
1. ## logarithm help.
How do you solve this? Why does the answer become squareroot(3)-1??
2. ## Re: logaithm help.
Originally Posted by Iamnothere
How do you solve this? Why does the answer become squareroot(3)-1??
Because $\sqrt3>1$ we must rewwrite $\log_{25}(1-\sqrt3)^2=2\log_{25}(\sqrt3-1)$
Note $25^{\log_{25}(\sqrt3-1)}=\sqrt3 -1$
3. ## Re: logaithm help.
$5= 25^{1/2}$ so
$5^{log_{25}(a)}= (25^{1/2})^{log_{25}(a)}= 25^{(1/2)log_{25}(a)}= 25^{log_{25}(\sqrt{a})}= \sqrt{a}$
4. ## Re: logaithm help.
Do you mind me asking where does that rule come from? The one with sqrt(3)>1, I'm a little bit confused.
5. ## Re: logaithm help.
Originally Posted by Iamnothere
Do you mind me asking where does that rule come from? The one with sqrt(3)>1, I'm a little bit confused.
??? You will accept 3> 1 won't you? And square root is an increasing function so $\sqrt{3}> \sqrt{1}= 1$. In fact, it is not at all difficult to use a calculator to see that $\sqrt{3}= 1.7320508075688772935274463415059... > 1$.
Or do you mean " $ln(1- \sqrt{3})^2)= 2ln(\sqrt{3}- 1)$"?
Obviously both $(1- \sqrt{3})^2$ and $(\sqrt{3}- 1)^2$ give the same thing and $log(a^2)= 2log(a)$ provided that a is positive becauser log(a) is not defined for negative a.
6. ## Re: logaithm help.
Emm, I think you got me a little bit wrong here, I was just wondering why did we have to write sqrt(3)-1 instead of 1-sqrt(3).
Edit: Ah yeah, I totally forgot about looking at that part. Thank you. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 11, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9527662396430969, "perplexity": 1757.6237082285425}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368704933573/warc/CC-MAIN-20130516114853-00053-ip-10-60-113-184.ec2.internal.warc.gz"} |
https://www.physicsforums.com/threads/thermal-physics-problem-please-help.534222/ | 1. Sep 27, 2011
### kottur
1. The problem statement, all variables and given/known data
Consider a CO2 molecule, which is linear and has vibrational modes with frequency
corresponding to 2565 cm-1 (an asymmetric stretch), 1480 cm-1 (a symmetric stretch)
526 cm-1 (bends). Sketch a curve showing how the constant volume heat capacity of CO2
gas varies with temperature and mark the values of plateaus. (Recall: the spacing between
rotational levels is smaller than the spacing between the vibrational levels).
3. The attempt at a solution
I don't have a clue where to start!
2. Sep 27, 2011
### FactorsOf2
Assume you can treat the CO2 gas classically and try using these main ideas:
1) Equipartition of Energy theorem says that each degree of freedom (for example translational motion along x-axis) which shows up quadratically in the total energy of the molecule contributes an average 1/2kBT to the energy of the molecule.
2) Some degrees of freedom ('modes') require more energy to excite and so they do not contribute to the total energy at lower temperatures. For example, only the three translational degrees of freedom ('x', 'y' and 'z') contribute for the lowest temperatures.
3) The wavenumbers (cm-1) corresponding to each vibrational mode listed are related to the energy of the mode.
4) Constant Vololume heat capacity is defined as dEtot/dT
Bit hand-wavey but I think that's the idea. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9095147848129272, "perplexity": 1145.6556593410294}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-47/segments/1510934803906.12/warc/CC-MAIN-20171117185611-20171117205611-00623.warc.gz"} |
https://homework.cpm.org/category/CC/textbook/ccg/chapter/10/lesson/10.3.5/problem/10-176 | ### Home > CCG > Chapter 10 > Lesson 10.3.5 > Problem10-176
10-176.
Of the students who choose to live on campus at Coastal College, $10$% are seniors. The most desirable dorm rooms are in the newly constructed OceanView dorm, and $60$% of the seniors live there, while $20$% of the rest of the students live there.
1. Represent these probabilities in a two-way table.
Ocean View Not Ocean View Senior $(0.60)(0.10)=\mathbf{0.06}$ $0.10$ Not Senior $(0.20)\mathbf{(0.90)}=\mathbf{0.18}$ $1.00$
2. What is the probability that a randomly selected resident of the OceanView dorm is a senior?
Compare the percentage of seniors who live in OceanView to the percentage of total students who live in OceanView.
$25\%$
3. Use the alternative definition of independence (see the Math Notes box in Lesson 10.2.3) to determine if being a senior is associated with living in the Ocean View dorm.
If events $\text{A}$ and $\text{B}$ are independent, then $\text{P}(\text{A and B})=\text{P}(\text{A})·P(\text{B})$.
The converse of this statement is also true: $\text{P}(\text{A and B})=\text{P}(\text{A})·P(\text{B})$, then $\text{A}$ and $\text{B}$ are independent. | {"extraction_info": {"found_math": true, "script_math_tex": 14, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7271069288253784, "perplexity": 1335.83425205327}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358189.36/warc/CC-MAIN-20211127133237-20211127163237-00209.warc.gz"} |
https://www.compadre.org/picup/exercises/exercise.cfm?A=GWring | +
Visualizing Effects of a Gravitational Wave with a Ring of Test Masses
Developed by Deva O'Neil - Published June 27, 2018
This ES allows students to explore different polarizations of gravitational waves and simulate the effect on a ring of test masses. Intuition for vector fields is developed as well. The student compares the response of a ring of test masses to plus-polarized waves, cross-polarized waves, and circularly-polarized waves. After getting a feel for polarizations, we put the simulation in an astrophysical context. For the source, we use a system revolving around a center of mass (we start with the Alpha Centauri binary system as a model). To gain insight into what effect on the wave different parameters have, students modify the simulation to compare a compact binary to the Alpha Centauri system. These simulations ignore the effect that radiating gravitational waves has on the source itself. Those interested in modeling this "back-reaction" are encouraged to consult Robert Hilborn's Exercise Sets, which focus on the evolution of the waveform and the modeling of the source, rather than the effect the gravitational wave would have on a detector or test mass.
Subject Areas Waves & Optics, Mathematical/Numerical Methods, and Astronomy/Astrophysics Advanced Glowscript - The student will simulate and interpret a vector field. The student will calculate divergence and identify, visually and mathematically, a divergence-free vector field (Exercises 1 and 2). - Students will simulate a ring of test masses to determine how the gravitational wave determines the motion of the test masses. Wave parameters such as amplitude and frequency are analyzed in terms of their effect on the motion (Exercise 3). - The student will relate the physical behavior of the system to the choice of initial conditions for coupled ODEs. Using calculus, the initial conditions for the test masses that result in pure oscillatory motion will be derived (Exercises 3 and 4). - The student will construct a circularly-polarized wave from plus and cross polarizations, and will determine the effect of right- and left-circularly polarized waves on a ring of test masses (Exercise 4). - The student will develop intuition for the properties of an astrophysical system as a source of gravitational waves. The student will identify parameters that affect detectability and then compare gravitational wave amplitudes for ordinary binary stars (Exercise 4) to compact binaries (Exercise 5). 300 min
These exercises are not tied to a specific programming language. Example implementations are provided under the Code tab, but the Exercises can be implemented in whatever platform you wish to use (e.g., Excel, Python, MATLAB, etc.).
**Exercise 1: Force Fields** A force field, like any field, associates a value with each point in space. Since force is a vector, the force field due to the gravitational wave can be represented with an arrow (to indicate both magnitude and direction) at every point in space. In the programs that follow, we will ignore the z direction and analyze force fields in the x-y plane. We will start with a program that places an arrow, representing force, at every point on a 15 x 15 grid. The point (0,0) will be in the middle of the grid. We will begin with a constant and uniform force field before modeling a gravitational wave. A physical example is gravity near the surface of the Earth. It is approximately constant in time[^footnote] and uniform on small scales. 1. Run the template provided for Exercise 1. The force used is $\vec{F} = <0,-mg,0>$, where $g = 9.8 ~m/s^2$. 2. The divergence of a vector field $\vec{A}$ is defined as $div \vec{A} = \frac{\partial A_x}{\partial x}+\frac{\partial A_y}{\partial y}+\frac{\partial A_z}{\partial z}$. The value of the divergence may depend on (x,y,z), in which case it varies from point to point in the field. Physically, it represents the net flux (flow) from an infinitesimal volume surrounding a point. One can get an intuitive feel for whether a field has non-zero divergence in a certain region by visually examining the flux. We will imagine a small volume centered on a certain point in the field. Roughly speaking, a field that appears to be (overall) "exiting" the volume has a positive divergence; a field with a net "entrance" into the volume has a negative divergence. If there is equal entrance and exit, there is no divergence. Before continuing, it may help to get some practice identifying positive and negative divergences. The following links give examples where the divergence is either positive at all points, or negative at all points: https://mathinsight.org/divergence_idea https://mathinsight.org/divergence_subtleties When you feel comfortable recognizing divergence, return to examining your template. * Looking at the output of this program, predict whether the divergence of the field is positive, negative, or zero. * Check your prediction with a direction calculation (on paper). * Modify the code to display a force field with positive divergence. (The force field does not have to have physical significance.) **Exercise 2: Gravitational Wave Polarization** 1. Change your code so that it visualizes the following gravitational wave: $$F_{x}= \frac{-m}{2} h_{+} x\omega^{2}\cos(\omega t),$$ $$F_{y}= \frac{m}{2} h_{+} y\omega^{2}\cos(\omega t).$$ Each grid point has a different $(x,y)$ value, and thus a different value of force. The following parameters are recommended: | Parameter | Symbol | Value | | ------------- |:-------------:| -----:| | Amplitude of gravitational wave | $h_{+}, h_{\times}$ | $0.2$ | | Angular frequency of oscillation | $\omega$ | $50 ~rad/s$ | | Mass of object subject to force field | $m$ | $0.1~ kg$ | | Time | $t$ | $0$ | This will show the output at a time $\omega t =0$. 2. Let's check to make sure the force field is plausible. Suppose we examine the arrow at the upper right-hand corner. $F_x$ at this point depends on $x$, $\cos(\omega t)$, and a factor $\frac{-m}{2} h_{+} \omega^{2}$. Let's figure out whether $F_x$ is overall negative or positive by examining these in turn. First, what is (x,y) for this grid point? The middle of the plot is (0,0), and the points range from -7 to +7 in each direction, incrementing in integer steps. Therefore, the value of (x,y) at this point is (+7,+7). The factor $x$ is positive. * Is $\cos(\omega t)$ positive, negative, or zero at $\omega t =0$? * What about $\frac{-m}{2} h_{+} \omega^{2}$? * Use your answers above to determine if $F_{x}$ negative, zero, or positive. * Do the same for $F_{y}$. * Based on your answer, determine the direction of the force arrow at this point. Compare to the output of the code. If they disagree, resolve the discrepancy. Another way to check the plausibility of the output is to calculate the divergence. 3. Looking at the output of your program, predict whether the divergence is positive, negative, or zero. 4. Calculate the divergence of this force (assume the z-component is zero). Hint: for $F_x$, as far as the variable "x" is concerned, the force looks like: $F_x = const*x$. The time-dependent cosine term has no explicit x dependence, so in calculating $\frac{\partial F_x}{\partial x}$, it is treated like a constant. 5. Finally, check that your plot of the force field resembles a plus sign. This wave is called plus-polarized. The term "polarization" refers to the direction of the force field (not the direction the wave is travelling). Here, the wave travels in the z-direction, but the polarization is in the x-y plane. Light waves work similarly - if an electromagnetic plane-wave is travelling in the z direction, the polarization (direction of the associated electric field) is in the x-y plane. These types of waves are known as "transverse." *Gravitational Waves: Cross Polarization* 6. Repeat the exercise above for the cross polarization, $$F_{x}= \frac{-m}{2} h_{\times}y \omega^{2}\cos(\omega t),$$ $$F_{y}= \frac{-m}{2} h_{\times}x \omega^{2}\cos(\omega t).$$ Note that the placements of $x$ and $y$ are reversed. As before, perform at least 3 plausibility checks on the output: 7. Pick a point and determine the direction of the force at that point using the above equations. Compare with the arrow direction at that point. 8. All gravitational waves in this Newtonian approximation are divergence-free. Check that the divergence is zero (visually and mathematically). 9. Check that the output resembles a cross. [^footnote]: The small changes of Earth's surface gravity with time (due to mass shifting around) are a major factor that limits the precision of ground-based gravitational wave detectors. For this reason, space-based gravitational wave detectors (eg, LISA) have been designed. **Exercise 3: Effect of Gravitational Waves on a Ring** In this exercise, we will allow the force due to the gravitational wave to evolve in time, and show the effect on a ring of test masses in the x-y plane. Each test mass will have a different value of $(x_0,y_0)$ that it will oscillate around as a result of being in the force field. In this Newtonian approximation, force determines the acceleration of the test masses through Newton's 2nd law. In the x direction, this gives (for the plus polarization): $$F_x = m \ddot x.$$ which gives $$\ddot x= \frac{-1}{2} h_{+} x\omega^{2}\cos(\omega t). \label{ac1}$$ The motion of the test mass at location $x_0$ can be written $x(t) = x_0 + \delta x$, where the displacements $\delta x$ are small compared to $x_0$. Since $x_0$ has no time dependence, $\ddot{x_0} = 0$, and thus eq. \ref{acc} actually represents $\ddot{ \delta x}$: $$\ddot{\delta x}= \frac{-1}{2} h_{+} x\omega^{2}\cos(\omega t). \label{acc}$$ To simulate this system numerically, starting with acceleration and allowing the program to determine the subsequent motion, we need to set the initial conditions for each test mass. The point $(x_0,y_0)$ is not (necessarily) the initial position of each mass; it is the equilibrium position that the mass oscillates around. We will call the initial positions and velocities $(x_i,y_i)$ and $(v_{xi},v_{yi})$. A convenient choice for the initial conditions is to set them so that the resulting motion is purely oscillatory around the point $(x_0,y_0)$. In the calculations that follow, you will use calculus to determine what these initial values will need to be. So that we can solve this equation analytically, we will approximate $x(t) \approx x_0$ in eq. \ref{acc}, and take $\omega$ and $h_{+}$ to be constant. Thus, the equation to solve is: $$\ddot{ \delta x}= \frac{-1}{2} h_{+} x_0\omega^{2}\cos(\omega t).$$ * Integrate this equation twice to derive $\delta x$ as a function of time. Show that the solution has the form: $\delta x= \frac{h_{+}}{2}x_0\cos(\omega t)+v_{xi} t + c_2$, or equivalently: $$x(t) = x_0 + \delta x=x0+ \frac{h_{+}}{2}x_0\cos(\omega t)+v_{xi} t + c_2 \label{sol}$$ To get motion that oscillates around $x_0$, we need to set $v_{xi} = 0$ and $c_2 = 0$. But our simulation doesn't allow us to input $c_2$ directly; our inputs are the initial conditions. * Find the value of $x_i$ that corresponds to $c_2 = 0$ by setting $t = 0$ and $x(0) = x_i$ in eq.\ref{sol}. Hint: you should find that the test mass has to be initially displaced from its equilibrium value $x_0$ in order to get $c_2 = 0$. * Now, find the initial conditions for the y component of the motion similarly. Integrate the acceleration in the y direction twice, and find the value of $y_i$ that corresponds to $c_2 = 0$. As before, determine the value of $v_{yi}$ that eliminates the linear term in $y(t)$. * Simulate the effect of this gravitational wave on a ring of test masses using the template for Exercise 3. You'll need to put in the force and the initial conditions. Use $x_0$ instead of $x$, and $y_0$ instead of $y$, when you enter the force. (Otherwise, the force you are simulating will not exactly match the force you used to determine the desired initial conditions.) Plausibility checks: * Do you observe behavior consistent with a "plus" polarization? * Do the masses oscillate around $(x_0,y_0)$? If the motion is shifted, the initial position is not quite right. If they fly off to infinity, the initial velocity is not quite right. (Physically, there is nothing wrong with making the initial conditions anything you like, but for the purposes of understanding the effect of the force, it is helpful to remove the "flying off" behavior.) *Analysis* For each of the following parameters in the simulation, describe in words what effect the parameter has on the motion of the test masses. If it has no effect, explain why not. For example, try changing $R$, the radius of the ring of test masses. Does the amount of deformity of the ring change as a result? Why or why not? | Parameter | Effect on motion (if none, explain why not) | | ------------- |:----------------------------------------------------------:| | $h_{+}$ | | | $\omega$ | | | $R$ | | * Copy your code into a new file so that you don't overwrite your existing code. Modify your simulation so that it shows the cross polarization. Make sure to re-derive the initial positions, since they will be different than before. * Perform plausibility checks, as before, to confirm that your program is working correctly. **Exercise 4: Orbiting Systems and Circular Polarization** Objects that orbit each other create gravitational waves. In this section, our source of gravitational waves are two masses, $m_1$ and $m_2$, that orbit in the x-y plane, with the origin at the center of mass of the system. This could represent a system where the two masses are of comparable size, such as a binary star system, or one in which a planet orbits a star. The gravitational waves produced by this system will be the same as would arise from a single mass $\mu$ orbiting at a radius $A$. (We will assume that this orbit is circular). This effective radius $A$ is equal to the difference in the orbital radii of the physical masses ($\vec{r_i}$). Specifically, $$\mu = \frac{m_1 m_2}{m_1+m_2}\label{mu}$$ and $$A \equiv |\vec{r_1} - \vec{r_2}|$$ Let's imagine that our gravitational wave detector (which we will again model as a ring of test masses) is placed on the z axis, a far distance $r$ from the source of the gravitational waves. In this case, the resulting gravitational wave will have both plus and cross polarizations at the same time. The angular frequency of the gravitational wave turns out to have twice the angular frequency of the orbiting sources. The frequency of the source will be denoted $\omega_s$. $$h_{+}(t) = \frac{4G\mu \omega_{s}^{2} A^2}{rc^4}\cos(2\omega_s t),$$ $$h_{\times}(t) = \frac{4G\mu \omega_{s}^{2} A^2}{rc^4}\sin(2\omega_s t).$$ Note that Newton's gravitational constant (G) appears, because these equations come from the Einstein equation. The Einstein equation relates the stress-energy tensor (information about mass/energy) to the curvature of spacetime. The constant $G$ tells spacetime how strongly to curve in response to the mass/energy present. * Explain what happens to the amplitudes $h_{+}$ and $h_{\times}$ as the detector gets farther from the source. (The distance between them is $r$). Why does this make sense? * Determine the initial conditions that will produce purely oscillatory motion for $\delta x$ and $\delta y$ (no constant or linear terms). You'll have to obtain acceleration from the force equations, and then integrate twice to find $\delta x$ and $\delta y$. As before, approximate $x$ and $y$ as $x_0$ and $y_0$. Hint: You should find that the initial velocity in the x direction must be $\dot {\delta x}(0)= \frac{G\mu \omega_{s}^{3} A^2}{rc^4} y_0$, in order to make the first constant of integration equal zero. Once you have determined the four initial conditions, you are ready to simulate this gravitational wave. * Without overwriting your previous program, create a program to model this gravitational wave. The net force will be the sum of the contributions from the two polarizations: $$F_{x}= \frac{-m}{2}[ h_{\times}(t) y +h_{+}(t) x],$$ $$F_{y}= \frac{m}{2}[ h_{+}(t) y- h_{\times}(t)x ].$$ The following parameters are recommended (taken from measurements of the Alpha Centauri system, a group of stars about 4 light-years from Earth). | Parameter | Symbol | Value | | ------------- |:-------------:| -----:| | Reduced mass of system | $\mu$ | $0.50~ M_{\odot}$| | Angular frequency of source | $\omega_s$ | $2.5\cdot 10^{-9} ~rad/s$ | | Radius of source orbit | $A$ | $18~AU$ | | Distance from test masses to source| $r$ | $267,000~ AU$ | |Radius of ring of test masses |$R$ | $6.0~m$| Masses are conveniently expressed in "solar masses," $m_\odot = 1.989*10^{30}~kg$. An astronomical unit is $AU = 1.496\cdot10^{11}~m$. When you write your code, make sure to convert all units to SI to avoid inconsistencies. If you run your code with these parameters, you won't see any displacement of the test masses. They will just sit there. This makes sense because if ripples in spacetime were large enough to see the distortion of objects, we would see them in real life, and wouldn't need a kilometer-long detector to find them. In reality, gravitational waves, while omnipresent, are so small that they require heroic experimental efforts to detect even with 21st century instruments. To be able to get visible results in our program, we'll need to exaggerate the amplitude of the wave. * Scale up your parameters so that the apparent amplitude of the wave is $~0.2$ or higher. Plausibility checks * Do you observe that each mass is moving in a small circle? * Do the masses oscillate around $(x_0,y_0)$? If the motion is shifted, the initial position is not quite right. * Do the masses stay near $(x_0,y_0)$, or do they fly off to infinity? If they fly off, the initial velocity should be checked. Also, make sure that you have approximated $(x,y)$ in the force as $(x_0,y_0)$. This circling behavior is a signature of a circularly-polarized wave. As written, the masses circulate counter-clockwise; this is called "right-hand circularly polarized," since it matches the orientation of your right hand when your thumb points back at you. * Convert your wave to a left-hand circularly polarized wave by multiplying $F_y$, but not $F_x$, by a minus sign. (Make sure to modify $v_{iy}$ and $y_i$ accordingly). Check your output to make sure you get the masses circulating in small clockwise circles. We have been assuming that the detector is on the z-axis, so that it looks at the orbital plane "head on." If the orbit of this source had been oriented differently relative to the detector, the polarization would no longer be purely circularly-polarized. Thus, experimentalists are interested in determining the polarization of a gravitation wave, since it reveals the orientation of the orbit of the source. **Exercise 5: Detecting Gravitational Waves** In the previous section, we found that the gravitational waves produced by Alpha Centauri have tiny amplitudes - on the order of $10^{-23}$ when they reach Earth. Surprisingly, it is not this tiny amplitude that is the biggest limitation to detecting the stars' gravitational waves. Gravitational wave detectors, such as LIGO, can only sense gravitational waves with frequencies above $1~Hz$. The optimum frequency for Advanced LIGO is $10^2~ - ~10^3 ~Hz$. For our purposes, we'll assume that our detector can pick up a gravitational wave signal if its amplitude is at least $10^{-22}$ and its frequency falls within this range. Frequency, when measured in Hz, indicates how many cycles per second the system is making. How can a binary star system possibly make 10 revolutions *per second*? Would it have to go faster than the speed of light? Let's find out. The speed of an object moving in a circle is determined by both its frequency and the radius of the orbit ($A$). * Use the formula for tangential velocity ($v = \omega A$) and a frequency of $10~Hz$ to determine how large the radius of the orbit can be, while keeping $v$ no more than one-tenth the speed of light. (Recall that $\omega = 2\pi f$). Your answer will turn out to be smaller than the radius of the Earth (6,000 km). And yet, this is a typical scale for the orbit of "compact binaries" - binary systems composed of neutron stars and/or black holes. These are the sources of gravitational waves that LIGO is designed to find. Our final goal is to simulate the effect of a compact binary system. First, we need to make sure that the value used for the frequency of the orbit is consistent with the orbital radius - as stars get closer to each other, it takes less and less time for them to complete an orbit. In this simulation, we ignore the inward spiralling of the orbit, and approximate the radius as constant. Undergoing uniform circular motion at radius $A$, the centripetal acceleration of the system is $$a_c = \frac{v^2}{A} = \frac{G(m_1+m_2)}{A^2}.$$ This equation, combined with $v = \omega A$, requires $A =( 2 G m_s/\omega_s^{2})^{1/3}$. * With the values in the table below (and eq. \ref{mu}), simulate a binary neutron star system. Copy your code from Exercise 3 into a new file so that you don't overwrite it. | Parameter | Symbol | Value | | ------------- |:-------------:| -----:| | Mass of each star | $m_i$ | $1.4~ M_{\odot}$| | Angular frequency of source | $\omega_s$ | $2\pi(10~Hz) ~rad/s$ | | Radius of source orbit | $A$ | $(2 G m_s/\omega_s^{2})^{1/3}$ | | Distance from test masses to source| $r$ |(variable) | * Experiment with the variable $r$ (keeping it much larger than the radius of the orbit, $A$). Can the detector get close enough to the star system to make the effect of gravitational wave visible to the naked eye? - How far away can a compact binary be and still be detectable by our detector - assumed to be sensitive to amplitudes as small as $10^{-22}$? Express the answer in Mega-parsecs ($1 Mpc = 3.086\cdot 10^{22}$ m). | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9181662797927856, "perplexity": 311.21615492740693}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039610090.97/warc/CC-MAIN-20210422130245-20210422160245-00220.warc.gz"} |
https://www.mat.uniroma1.it/ricerca/notiziario?notiziario=190513.html | Notiziario Scientifico
Notiziario dei seminari di carattere matematico
a cura del Dipartimento di Matematica G. Castelnuovo, Sapienza Università di Roma
Settimana dal 13-05-2019 al 19-05-2019
Lunedì 13 maggio 2019
Ore 12:00, Aula 311, Dipartimento di Matematica e Fisica, Largo S. L. Murialdo 1
Seminario di Crittografia
Luca De Feo (Université de Versailles)
Isogeny graphs in cryptography: the good, the bad and the ugly
Isogenies of elliptic curves have recently come under the spotlight thanks to their applications in post quantum cryptography. The two prominent isogeny-based primitives, SIDH and CSIDH, provide, respectively, the key encapsulation with the lowest communication complexity among all candidates to the NIST post-quantum competition, and the only known efficient post-quantum non-interactive key exchange. Computational problems related to isogenies have been studied for more than 30 years, owing to their connections to elliptic curve cryptography. I will thus start by reviewing the relevant computational problems, and highlight some recent results. I will then introduce isogeny graphs, and explain how they are useful in cryptography; in particular I will point out what they are good for, what they are not-so-good at, and what they are absolutely terrible at. Finally, I will present some research perspectives and some important open problems.
Lunedì 13 maggio 2019
Ore 14:15, Aula Consiglio, Dipartimento di Matematica, Sapienza Università di Roma
Seminario di Analisi Matematica
Stephane Junca (University of Nice Sophia Antipolis, Nice, France)
Hyperbolic conservation laws, oscillations and fractional BV spaces
In 1994, a Lions, Perthame and Tadmor conjecture proposes an optimal regularity in fractional Sobolev spaces for entropy solutions of nonlinear multidimensional scalar conservation laws. The first optimal result for uniformly convex fluxes by Lax and Oleinik 1957 is stated in BV ( space of functions with bounded variation) which gives the sharp Sobolev regularity and, moreover, the trace property on each side of a shock wave. Unfortunately, "BV is not enough" to explain this conjecture. Examples of strongly oscillating waves not in BV are presented. Fractional BV spaces seem to be appropriate to encompass these examples and retain the "BV trace property" and the optimal Sobolev exponent conjectured by Lions, Perthame and Tadmor.
Lunedì 13 maggio 2019
Ore 15:30, Aula 5, Università UNINT, Via C. Colombo 200
Seminario
Alexandra Otiman (Università Roma Tre e Institute of Mathematics "Simon Stilov", Romanian Academy)
Geometria Hermitiana e complessa di una sottoclasse di varietà di Kato
Martedì 14 maggio 2019
Ore 14:00, Aula Dal Passo, Dipartimento di Matematica, Università di Roma Tor Vergata
Seminario di Analisi Matematica
Jingang Xiong (Beijing Normal University)
On asymptotic behavior of solutions of conformally invariant equations with isolated singularities.
I will review some classical results of conformally invariant equations with isolated singularities. I will report a recent joint work with Tianling Jin, in which we solved the higher order case. Our approach uses blow up analysis for local integral equations, and is unified for all critical elliptic equations of order smaller than the dimension.
(*) this seminar is part of the activity of the MIUR Excellence Department Project CUP E83C18000100006
Martedì 14 maggio 2019
Ore 15:00, 1B1, Pal. RM002, Dipartimento SBAI, Sapienza Università di Roma
Incontri di Algebra e Geometria allo SBAI
Salvatore Stella (University of Haifa (Israel))
Acyclic cluster algebras via Coxeter double Bruhat cells and generalized minors
Cluster algebras come with a canonical partial basis: the cluster monomials. Extending this partial basis to a full basis has been one of the central problems in the theory giving raise to a varied zoo of constructions. In this talk we will explain how Lie theory can be used to relate them. Specifically, after recalling the basic definitions, we will explain how any acyclic cluster algebra can be seen as the ring of coordinates of a suitable double Bruhat cell in the associated Kac-Moody group. Under this identification we will interpret cluster monomials as generalized minors -- certain functions on a Kac-Moody group defined in terms of its representations -- and explain how one can use generalized minors to extend cluster monomials to a continuous family of bases of the cluster algebra in the affine cases. This talk is based on joint works with D. Rupel and H. Williams
Martedì 14 maggio 2019
Ore 15:00, Aula Dal Passo, Dipartimento di Matematica, Università di Roma Tor Vergata
Seminario di Analisi Matematica
Yeyao Hu (University of Texas at San Antonio)
Uniqueness and symmetry of solutions to a mean field equation on tori.
We prove a sharp uniqueness result of a mean field equation on arbitrary flat tori. We first establish the evenly symmetry of the solutions by the newly invented sphere covering inequality which is of independent interest. Then we employ a careful nodal line analysis together with a homotopic argument to show the uniqueness.
(*) this seminar is part of the activity of the MIUR Excellence Department Project CUP E83C18000100006
Martedì 14 maggio 2019
Ore 15:00, Aula di Consiglio, Dipartimento di Matematica, Sapienza Università di Roma
Seminario di Modellistica Differenziale Numerica
Andrea Moiola (Dipartimento di Matematica F. Casorati, Università di Pavia)
Acoustic and electromagnetic transmission problems: wavenumber-explicit bounds and resonance-free regions
We consider the Helmholtz and the time-harmonic Maxwell transmission problems with one penetrable star-shaped Lipschitz obstacle. Under a natural assumption about the ratio of the wavenumbers, we prove bounds on the solution in terms of the data, with these bounds explicit in all parameters. For example, in the case of the Helmholtz equation, the (weighted) $$H^1$$ norm of the solution is bounded by the $$L^2$$ norm of the source term, independently of the wavenumber. Such explicit bounds are key to developing frequency-explicit error analysis for numerical methods such as FEM and BEM. The "shape-robustness" allows to quantify how variations in the shape of the obstacle affect the solution and makes the bounds particularly suitable for uncertainty quantification (UQ) applications. These bounds then imply the existence of a resonance-free strip beneath the real axis. If the assumption on the wavenumbers is lifted, then no bound with polynomial dependence on the wavenumber is possible. Joint work with Euan Spence (University of Bath).
Martedì 14 maggio 2019
Ore 15:00, Aula primo piano, IAC-CNR, Via dei Taurini 19
Seminario IAC
Alberto Saracco (Università di Parma)
Fighting Gerrymandering: a discrete approach
Whenever an election is run dividing the population into electoral districts, each based on winner-takes-all, the Gerrymangdering phenomenon appears. Over 2 centuries ago, Massachusetts' Governor Gerry modified the boundaries of his own ellectoral district in order to assure his re-election. Indeed, whenever two parties (or candidates) run for an election, if one of them has more then one third of the votes, the electoral districts can be shaped in order to assure its electoral win. Thus a double-faced problem arises: on one hand a method is needed to measure how gerrymandered a district is; on the other hand it would be useful to have an objective method to shape districts and avoiding the possibility of gerrymandering. A great part of the mathematical studies on the problem have been devoted either to geometrical propertiesof the district or on the application of the theory of isoperimetrical problems in this area. Recently it has been pointed out that it would be more realistic a discrete geometry approach, based on graphs and nets. In this talk I will present a discrete districting plan proposed by Giorgio Saracco and myself and analyse its properties.
Mercoledì 15 maggio 2019
Ore 14:00, Aula di Consiglio, Dipartimento di Matematica, Sapienza Università di Roma
Seminario di Algebra e Geometria
Francesco Bonsante (Università di Pavia)
Energia $$L^1$$ di mappe tra superfici iperboliche e teoria di Teichmüller
Nel seminario parlerò di una energia $$L^1$$ di mappe tra superfici iperboliche, introdotta da Trapani e Valli. I punti critici di tali mappe sono caratterizzati da essere mappe che preservano l’area e il cui grafico è una superficie minima. Schoen ha mostrato che in ogni classe di omotopia di mappe esiste sempre un unico rappresentante minimizzante per questa energia $$L^1$$. Considerando lo spazio di Teichmüller $$T(S)$$ come lo spazio delle metriche iperboliche su $$S$$ a meno dell’azione dei diffeomorfismi isotopi all’identità, considererò la funzione su $$T(S) \times T(S)$$ ottenuta minimizzando l’energia $$L^1$$ dell’identità sulle orbite. In particolare discuterò come tale funzione degenera quando una delle variabili diverge ad un punto del bordo di Thurston di $$T(S)$$. Nella seconda parte del seminario proporrò una generalizzazione del funzionale nel caso di mappe da una superficie iperbolica in una tre varietà, ricavandone l’equazione di Eulero-Lagrange e studiando lo spazio delle immersioni minimizzanti. Il lavoro presentato è in collaborazione con Gabriele Mondello e Jean-Marc Schlenker.
Giovedì 16 maggio 2019
Ore 14:30, Aula 211, Dipartimento di Matematica e Fisica, Largo S. L. Murialdo 1
Seminario di Geometria
Alex Kuronya (University of Frankfurt)
Effective global generation on manifolds with numerically trivial canonical bundle
If L is a line bundle on a projective manifold, then the existence of effective bounds for its tensor powers to have global sections or become globally generated have been a central problem in algebaic geometry for the last 150 years. While the case of curves follows from Riemann-Roch, satsifactory answers for surfaces only arrived about thirty years ago. Research in the area has been mostly motivated by Fujita's conjectures predicting the global generation and very ampleness of certain adjoint line bundles. In this talk we will consider the case of effective global generation for projective manifolds with numerically trivial canonical bundle. This is an account of joint work with Yusuf Mustopa.
Giovedì 16 maggio 2019
Ore 14:30, Aula di consiglio, Dipartimento di Matematica, Sapienza Università di Roma
P(n)/N(p) : Problemi differenziali nonlineari/Nonlinear differential problems
Tommaso Leonori (Sapienza)
Large solution for an equation involving the p-Laplacian with p diverging
In this talk we deal with explosive solutions to an equation of p-Laplacian type involving a nonlinear gradient term in a smooth bounded domain. We are interested in studying the behavior of the large solutions (i.e. solutions that blow-up at the boundary) as p diverges and in particular we will focus on how the limit depends on the domain.
Venerdì 17 maggio 2019
Ore 11:30, Aula 311, Dipartimento di Matematica e Fisica, Largo S. L. Murialdo 1
Seminario di Logica Matematica
Le Thanh Dung Nguyen (Université Paris 13)
Proof Nets Through the Lens of Graph Theory
One of the main innovations introduced by linear logic at its birth is a representation of proofs as graph-like structures called "proof nets", instead of trees as in natural deductions. However, there have been very few attempts to connect these proof nets with mainstream graph theory. In this talk, we will discuss the benefits of such connections: * Using a relationship between unique perfect matchings and MLL+Mix proof nets first noticed by Retoré, we obtain the best known algorithms for MLL+Mix correctness and sequentialization, and discover some purely graph-theoretical results inspired by linear logic.
(Reference for this part: https://arxiv.org/abs/1901.10247 )
* The notion of combinatorial map (already applied to the combinatorics of the lambda-calculus by Bodini-Gardy-Jacquot, Zeilberger-Giorgetti...) allows us to recast Girard's "long trip" criterion in terms of topology of surfaces, and also induces some clarifications in the theory of cyclic linear logic.
Le comunicazioni relative a seminari da includere in questo notiziario devono pervenire esclusivamente mediante apposita form da compilare online, entro le ore 24 del giovedì precedente la settimana interessata. Le comunicazioni pervenute in ritardo saranno ignorate. Per informazioni, rivolgersi all'indirizzo di posta elettronica seminari@mat.uniroma1.it.
Coloro che desiderano ricevere questo notiziario via e-mail sono pregati di comunicare il proprio indirizzo di posta elettronica a seminari@mat.uniroma1.it.
© Università degli Studi di Roma "La Sapienza" - Piazzale Aldo Moro 5, 00185 Roma | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8260329365730286, "perplexity": 5126.310795473082}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-30/segments/1563195524548.22/warc/CC-MAIN-20190716115717-20190716141717-00121.warc.gz"} |
http://www.distance-calculator.co.uk/towns-within-a-radius-of.php?t=Huiswaard&c=Netherlands | Cities, Towns and Places within a 60 mile radius of Huiswaard, Netherlands
Get a list of towns within a 60 mile radius of Huiswaard or between two set distances, click on the markers in the satelitte map to get maps and road trip directions. If this didn't quite work how you thought then you might like the Places near Huiswaard map tool (beta).
The radius entered failed to produce results - we reset it to a max of 60 miles - apologies for any inconvenience
# Distance Calculator > World Distances > Radius Distances > Huiswaard distance calculator > Huiswaard (Netherlands ) Radius distances
Get towns between and Miles KM
Click to View Visual Places on Map or View Visual Radius on Map
miles
Showing 0100 places between 10 and 60 miles of Huiswaard
(Increase the miles radius to get more places returned *)
< 25 miles > 25 miles
Barsingerhorn, Netherlands is 10 miles away
Bobeldijk, Netherlands is 10 miles away
Heemskerk, Netherlands is 10 miles away
Jisp, Netherlands is 10 miles away
Krommenie, Netherlands is 10 miles away
Lagedijk, Netherlands is 10 miles away
Lutjewinkel, Netherlands is 10 miles away
Middenbeemster, Netherlands is 10 miles away
Noordbeemster, Netherlands is 10 miles away
Noordermeer, Netherlands is 10 miles away
Oudendijk, Netherlands is 10 miles away
Schagerbrug, Netherlands is 10 miles away
Winkel, Netherlands is 10 miles away
Zuidermeer, Netherlands is 10 miles away
Aartswoud, Netherlands is 11 miles away
Beets, Netherlands is 11 miles away
Berkhout, Netherlands is 11 miles away
De Gouw, Netherlands is 11 miles away
Gouw, Netherlands is 11 miles away
Gouwe, Netherlands is 11 miles away
Meerestein, Netherlands is 11 miles away
Nes, Netherlands is 11 miles away
Scharwoude, Netherlands is 11 miles away
Sijbekarspel, Netherlands is 11 miles away
Wormer, Netherlands is 11 miles away
Benningbroek, Netherlands is 12 miles away
Beverwijk, Netherlands is 12 miles away
De Strook, Netherlands is 12 miles away
De Weere, Netherlands is 12 miles away
Harderwijk, Netherlands is 12 miles away
Hobrede, Netherlands is 12 miles away
Kolhorn, Netherlands is 12 miles away
Middel, Netherlands is 12 miles away
Neck, Netherlands is 12 miles away
Oosthuizen, Netherlands is 12 miles away
Purmerend, Netherlands is 12 miles away
Schardam, Netherlands is 12 miles away
Wijk Aan Zee, Netherlands is 12 miles away
Wognum, Netherlands is 12 miles away
Wormerveer, Netherlands is 12 miles away
Zaandijk, Netherlands is 12 miles away
Zuidoostbeemster, Netherlands is 12 miles away
t Zand, Netherlands is 13 miles away
Abbekerk, Netherlands is 13 miles away
Assendelft, Netherlands is 13 miles away
Callantsoog, Netherlands is 13 miles away
Hoorn, Netherlands is 13 miles away
Kalf, Netherlands is 13 miles away
Koog, Netherlands is 13 miles away
Koog Aan De Zaan, Netherlands is 13 miles away
Kwadijk, Netherlands is 13 miles away
Lambertschaag, Netherlands is 13 miles away
Molens, Netherlands is 13 miles away
Oudesluis, Netherlands is 13 miles away
Velsen-noord, Netherlands is 13 miles away
Warden, Netherlands is 13 miles away
Warder, Netherlands is 13 miles away
Westzaan, Netherlands is 13 miles away
Wijdewormer, Netherlands is 13 miles away
Zwaag, Netherlands is 13 miles away
Zwaagdijk-west, Netherlands is 13 miles away
Axwijk, Netherlands is 14 miles away
Boerdijk, Netherlands is 14 miles away
Ijmond, Netherlands is 14 miles away
Ijmuiden, Netherlands is 14 miles away
Middelie, Netherlands is 14 miles away
Midwoud, Netherlands is 14 miles away
Nibbixwoud, Netherlands is 14 miles away
Purmer, Netherlands is 14 miles away
Purmerland, Netherlands is 14 miles away
Velsen, Netherlands is 14 miles away
Velzen, Netherlands is 14 miles away
Wieringerwaard, Netherlands is 14 miles away
Ymuiden, Netherlands is 14 miles away
Zaandam, Netherlands is 14 miles away
Zaanstad, Netherlands is 14 miles away
Blokker, Netherlands is 15 miles away
De Heul, Netherlands is 15 miles away
Driehuis, Netherlands is 15 miles away
Groote Keeten, Netherlands is 15 miles away
Hauwert, Netherlands is 15 miles away
Ilpendam, Netherlands is 15 miles away
Middenmeer, Netherlands is 15 miles away
Oosterblokker, Netherlands is 15 miles away
Oostwoud, Netherlands is 15 miles away
Oostzaan, Netherlands is 15 miles away
Schellinkhout, Netherlands is 15 miles away
Twisk, Netherlands is 15 miles away
Twist, Netherlands is 15 miles away
Anna Paulowna, Netherlands is 16 miles away
Breezand, Netherlands is 16 miles away
Den Ilp, Netherlands is 16 miles away
Edam, Netherlands is 16 miles away
Hembrug, Netherlands is 16 miles away
Opperdoes, Netherlands is 16 miles away
Oudijk, Netherlands is 16 miles away
Santpoort, Netherlands is 16 miles away
Santpoort-noord, Netherlands is 16 miles away
Spaarndam, Netherlands is 16 miles away
Veldhuis, Netherlands is 16 miles away
Click to See place names or View Visual Places on Map
Click to go to the top or View Visual Radius on Map
World Distances
Need to calculate a distance for Huiswaard, Netherlands - use this Huiswaard distance calculator.
To view distances for Netherlands alone this Netherlands distance calculator
If you have a question relating to this area then we'd love to hear it! Chec out our facebook, G+ or Twitter pages above!
Don't forget you can increase the radius in the tool above to 50, 100 or 1000 miles to get a list of towns or cities that are in the vicinity of or are local to Huiswaard. You can also specify a list of towns or places that you want returned between two distances in both Miles(mi) or Kilometres (km) .
Europe Distances
* results returned are limited for each query | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.96422278881073, "perplexity": 14895.033491972114}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039603582.93/warc/CC-MAIN-20210422100106-20210422130106-00327.warc.gz"} |
https://www.physicsoverflow.org/7174/what-are-hidden-valley-sectors | # What are "hidden valley sectors"?
+ 2 like - 0 dislike
47 views
In this end of the year article, Prof. Strassler mentioned that hidden valley sectors could lead to some still open loopholes concerning the experimental discovery of supersymmetry and other BSM physics at the LHC such as certain kinds of extra dimensions for example. He only explains that these hidden valley sectors are some kind of an extension of minimal supersymmetric models and he does not explain this further when I ask him in the comments.
So I want to ask here:
What exactly are these hidden valley sectors, and how are they related to some kinds of minimal supersymmetric models, such as the MSSM for example? Are they rather ad hoc additions to the minimal models or are they embeded in some theories valid at higher energies?
reshown May 1, 2014
Thanks for debugging my question @twistor59 ;-), my typing was once more faster than my thinking ...
This post imported from StackExchange Physics at 2014-03-12 15:30 (UCT), posted by SE-user Dilaton
+ 2 like - 0 dislike
The name "hidden valley" models was coined in 2006 by Strassler and Zurek
http://arxiv.org/abs/hep-ph/0604261
and the paper above, references 1-6, show you the origin of these papers; 6 are stringy constructions. The models may be supersymmetric but they don't have to be. The "valley" refers to some place in the hidden dimensions of spacetime where an additional gauge group $G$ added as a factor to the Standard Model is localized. The new states are uncharged under the Standard Model and only charged under the new gauge group.
The new gauge group and the new particles/fields charged under the new group are ad hoc from the field theory viewpoint and there is no minimal choice. On the other hand, such new gauge groups and states are natural in string theory so it makes to study and realize what consequences such hypothetical states would have.
This post imported from StackExchange Physics at 2014-03-12 15:30 (UCT), posted by SE-user Luboš Motl
answered Dec 30, 2012 by (10,278 points)
Thanks a lot Lumo :-) It seems Prof. Strassler actually wants to get searches for such new particles at the LHC going.
This post imported from StackExchange Physics at 2014-03-12 15:30 (UCT), posted by SE-user Dilaton
Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead. To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL. Please consult the FAQ for as to how to format your post. This is the answer box; if you want to write a comment instead, please use the 'add comment' button. Live preview (may slow down editor) Preview Your name to display (optional): Email me at this address if my answer is selected or commented on: Privacy: Your email address will only be used for sending these notifications. Anti-spam verification: If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:p$\varnothing$ysicsOverflowThen drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds). To avoid this verification in future, please log in or register. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6218920350074768, "perplexity": 927.2582328898924}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-47/segments/1573496670921.20/warc/CC-MAIN-20191121153204-20191121181204-00209.warc.gz"} |
https://www.thepoorcoder.com/hackerrank-viral-advertising-solution/ | # Hackerrank - Viral Advertising Solution
HackerLand Enterprise is adopting a new viral advertising strategy. When they launch a new product, they advertise it to exactly people on social media.
On the first day, half of those people (i.e., ) like the advertisement and each shares it with of their friends. At the beginning of the second day, people receive the advertisement.
Each day, of the recipients like the advertisement and will share it with friends on the following day. Assuming nobody receives the advertisement twice, determine how many people have liked the ad by the end of a given day, beginning with launch day as day .
For example, assume you want to know how many have liked the ad by the end of the day.Day Shared Liked Cumulative1 5 2 22 6 3 53 9 4 94 12 6 155 18 9 24
The cumulative number of likes is .
Function Description
Complete the viralAdvertising function in the editor below. It should return the cumulative number of people who have liked the ad at a given time.
• n: the integer number of days
Input Format
A single integer, , denoting a number of days.
Constraints
Output Format
Print the number of people who liked the advertisement during the first days.
Sample Input
3
Sample Output
9
Explanation
This example is depicted in the following diagram:
### Solution in Python
a = 5
b = 0
for i in range(1,int(input())+1):
b += a//2
a = a//2*3
print(b) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.48558396100997925, "perplexity": 8613.16168581797}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323585696.21/warc/CC-MAIN-20211023130922-20211023160922-00298.warc.gz"} |
https://socratic.org/questions/how-do-you-write-1764-9-in-scientific-notation | Algebra
Topics
# How do you write 1764.9 in scientific notation?
Aug 2, 2016
$1.7649 \times {10}^{3}$
#### Explanation:
The objective is to have just one non zero digit to the left of the decimal and the rest of the numbers to the right. This changes the value so a correction has to be built, shown but not applied. In this case the correction is $\left(\times {10}^{3}\right)$
$\textcolor{b r o w n}{\text{With practice you will be able to do this in a lot less lines}}$
Showing what is happening 1 stage at a time
$\textcolor{b l u e}{\text{Stage 1}}$
Multiply by 1 but in the form of $\textcolor{m a \ge n t a}{1 = \frac{10}{10}}$
$1764.9 \textcolor{m a \ge n t a}{\times \frac{10}{10}} \text{ " =" " 1764.9/(color(magenta)(10))color(magenta)( xx 10)" " =" } 176.49 \times 10$
'.................................................................................................
$\textcolor{b l u e}{\text{Stage 2}}$
Multiply by 1 but in the form of $\textcolor{m a \ge n t a}{1 = \frac{10}{10}}$
$176.49 \times 10 \textcolor{m a \ge n t a}{\times \frac{10}{10}} \text{ " =" "176.49/10xx10^2" " =" } 17.69 \times {10}^{2}$
'..............................................................................................
$\textcolor{b l u e}{\text{Stage 3}}$
Multiply by 1 but in the form of $\textcolor{m a \ge n t a}{1 = \frac{10}{10}}$
$17.649 \times {10}^{2} \textcolor{m a \ge n t a}{\times \frac{10}{10}}$
$= \frac{17.649}{10} \times {10}^{3} \text{ "=" } \textcolor{b l u e}{1.7649 \times {10}^{3}}$
##### Impact of this question
171 views around the world | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 13, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8600482940673828, "perplexity": 616.1695821345841}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986668994.39/warc/CC-MAIN-20191016135759-20191016163259-00509.warc.gz"} |
http://codereview.stackexchange.com/questions/120374/check-if-a-string-has-20-numbers-in-a-row-in-it | # Check if a string has 20 numbers in a row in it
My code will check if the variable myString has 20 running numbers. I'm new to JavaScript and I'm wondering if there is a simpler way to do this. How can I shorten my code and possibly make it more efficient?
var myString = "tuxwuhkocx14789470019215498263ljmgwsxvne";
var runningNumbers = 0;
for (i = 0; i < myString.length; i++) {
var character = myString.charAt(i);
if (!isNaN(character)) {
// If character is a number:
runningNumbers = runningNumbers + 1;
} else {
// If character is NOT a number:
runningNumbers = 0;
}
if (runningNumbers == 20) {
console.log("myString has 20 running numbers.");
}
}
Output:
myString has 20 running numbers.
-
What should happen when there are more than 20 numbers in a row? – Ivan Modric Feb 18 at 8:36
@IvanModric, it will print the message again for each extra number past 20. – SparK Feb 19 at 11:15
I think it should be called digits, because 10, -1 and 0.5 might also be considered numbers. – SpaceTrucker Feb 19 at 12:14
That string has one number in it. A large one. You should say 'numerals' or 'digits'. – Octopus Feb 19 at 17:19
If you use a regular expression to look for 20 digit characters (\d) in a row, then the code would be compact and the goal would be visible at a glance:
var twentyDigits = /\d{20}/;
if (twentyDigits.test(myString)){
console.log("My string has 20 running numbers");
}
You can shorten this further as just:
if (/\d{20}/.test(myString)) console.log("Yup. 20");
-
Please mention that it can also be much faster this way as REs can in many cases just skip the input they don't care about - in this case, if you find a non-digit, you can easily skip 20 chars in advance. – d33tah Feb 19 at 11:37
It's simpler to use a regex as @Phrogz already pointed out.
There are other issues too in the posted code that should be pointed out and improved.
After finding 20 consecutive digits, the program will continue counting, pointlessly. I'm wondering if this was really your intention. It seems that perhaps you want to break out of the loop after finding 20 and stop searching.
Also note that you could move the condition on runningNumbers == 20 right after runningNumbers is incremented. When runningNumbers was not changed (character is not a digit), it's pointless to check its value (you know it's 0).
Instead of printing in a loop, I recommend to rewrite your test as a function returning a boolean value, true if a sequence was found. This way the responsibilities of searching and printing will be well separated.
As a tip on style, note that instead of x = x + 1, you can use the shorter x += 1 or ++x or x++.
-
Correct me if I'm wrong, but doesn't use of the RegEx method (instead of the code in the question) resolve all the bugs you've pointed out? – Iszi Feb 18 at 16:51
@Iszi it resolves those issues, but the poster might make those kind of mistakes again in other code if we don't point out and warn against them now. Also this is Code Review SE, not Alternative Implementation SE. – janos Feb 18 at 17:45
Next time through the loop after finding 20 digits, wouldn't it increment to 21 and no longer output? If he were doing >= 20 then, yeah. – GalacticCowboy Feb 19 at 17:58
@GalacticCowboy oh crap, you're right, well spotted. Updated now, thanks! – janos Feb 19 at 18:19
The regular expression /\d{20}/, as suggested by @Phrogz, is definitely the simplest and most idiomatic way to do this in JavaScript.
Since this is Code Review, I'm obligated to point out that you neglected to write var i, which is a likely cause of future bugs.
I also suggest using a conditional expression
runningNumbers = isNaN(myString[i]) ? 0 : runningNumbers + 1;
to emphasize the fact that one way or another, runningNumbers will get a new value.
-
As for efficiency, you can significantly reduce the number of characters you need to check by only checking every 20th character - you are guaranteed to hit every sequence of 20 consequtive numbers.
As so:
For every 20th character:
if character is a number:
length = 1
loop backwards to count numbers (add to length)
loop forwards to count numbers (add to length)
if length >= 20, break out with positive result
Whether this actually performs better than lets say using the regex method, youd need to measure that (I dont know how things compare in javascript...).
If Im thinking this correctly, this should be beneficial as long as over 1/20 of the characters are not numbers. In reality its probably higher due to the increased complexity of counting the 20 numbers (looping backwards and all...)
Works for any length of number sequence, of course.
If efficiency is not a concern, or if this actually performs worse in the real world, one of the shorter solutions is probably preferable.
-
CPUs read memory in whole cache line sized chunks. Skipping over bytes should not improve performance if the skip size is less than a whole cache line, assuming the loop is simple to execute and most of the time is spent in cache misses. However, this improvement would be great for looking for things bigger than a cache line. – doug65536 Feb 18 at 19:42
doug65536 , that may or may not be true. I was assuming javascript would generally be slowish, although some implementations might be fast enough to be memory bound (?). So checking if each character is a number and branching on that could be expensive, maybe even looping itself could be. Besides, think of the poor users who have intel hyperthreading which can take advantage of the latency gaps while other code is waiting for memory ;) (and cache misses shouldnt happen as cpu can predict linear reads usually) – Waterlimon Feb 19 at 8:25 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.256649374961853, "perplexity": 1480.063785055337}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-30/segments/1469257829325.58/warc/CC-MAIN-20160723071029-00234-ip-10-185-27-174.ec2.internal.warc.gz"} |
http://www.physicsforums.com/showpost.php?p=2257822&postcount=1 | View Single Post
P: 3 Hi all, question here from a non-scientist. Let's say I set up a double-slit experiment, with a detector at one or the other slit. I get it working, so that when I am able to determine the particle path, the interference pattern on the target screen disappears. Okay, now I leave the detector in place, but I cover it up so that however it is that it indicates where the particle is or isn't, the indication can no longer be seen by anyone. I think the interference pattern will nonetheless still be missing, right? Does this prove that whatever the mystery is, consciousness has nothing to do with it? And that furthermore, the effects on the cells in one's retina also has nothing to do with the "waveform collapse"? I believe I've read that which-way path detection is getting to the point where the detector might have no effect -- other than waveform collapse? -- on the particle... mystifying indeed. Thanks all, I look forward to your replies. Ted | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8054432272911072, "perplexity": 478.9888319137048}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-10/segments/1394010642209/warc/CC-MAIN-20140305091042-00065-ip-10-183-142-35.ec2.internal.warc.gz"} |
http://www.researchgate.net/profile/D_Kurtz/ | # D. W. Kurtz
University of Central Lancashire · Jeremiah Horrocks Institute (JHI)
## Publications (185) View all
• ##### Article:Asteroseismology of KIC 11754974: a high-amplitude SX Phe pulsator in a 343-day binary system
[show abstract] [hide abstract]
ABSTRACT: The candidate SX Phe star KIC 11754974 shows a remarkably high number of combination frequencies in the Fourier amplitude spectrum: 123 of the 166 frequencies in our multi-frequency fit are linear combinations of independent modes. Predictable patterns in frequency spacings are seen in the Fourier transform of the light curve. We present an analysis of 180 d of short-cadence Kepler photometry and of new spectroscopic data for this evolved, late A-type star. We infer from the 1150-d, long-cadence light curve, and in two different ways, that our target is the primary of a 343-d, non-eclipsing binary system. According to both methods, the mass function is similar, f(M)=0.0207 +/- 0.0003 Msun. The observed pulsations are modelled extensively, using separate, state-of-the-art, time-dependent convection (TDC) and rotating models. The models match the observed temperature and low metallicity, finding a mass of 1.50-1.56 Msun. The models suggest the whole star is metal-poor, and that the low metallicity is not just a surface abundance peculiarity. This is the best frequency analysis of an SX Phe star, and the only Kepler \delta\ Sct star to be modelled with both TDC and rotating models.
04/2013;
• ##### Article:Relationship between low and high frequencies in Delta Scuti stars: Photometric Kepler and spectroscopic analyses of the rapid rotator KIC 8054146
[show abstract] [hide abstract]
ABSTRACT: Two years of Kepler data of KIC 8054146 (delta Sct/gamma Dor hybrid) revealed 349 statistically significant frequencies between 0.54 and 191.36 c/d (6.3 microHz to 2.21 mHz). The 117 low frequencies cluster in specific frequency bands, but do not show the equidistant period spacings predicted for gravity modes of successive radial order, n, and reported for at least one other hybrid pulsator. The four dominant low frequencies in the 2.8 to 3.0 c/d (32 to 35 microHz) range show strong amplitude variability with timescales of months and years. These four low frequencies also determine the spacing of the higher frequencies in and beyond the delta Sct pressure-mode frequency domain. In fact, most of the higher frequencies belong to one of three families with spacings linked to a specific dominant low frequency. In the Fourier spectrum, these family regularities show up as triplets, high-frequency sequences with absolutely equidistant frequency spacings, side lobes (amplitude modulations) and other regularities in frequency spacings. Furthermore, within two families the amplitude variations between the low and high frequencies are related. We conclude that the low frequencies (gravity modes, rotation) and observed high frequencies (mostly pressure modes) are physically connected. This unusual behavior may be related to the very rapid rotation of the star: from a combination of high and low-resolution spectroscopy we determined that KIC 8054146 is a very fast rotator (v sin i = 300 +/- 20 km/s) with an effective temperature of 7600 +/- 200 K and a surface gravity log g of 3.9 +/- 0.3. Several astrophysical ideas explaining the origin of the relationship between the low and high frequencies are explored.
09/2012;
• ##### Article:Pulsational amplitude growth of the star KIC 3429637 (HD 178875) in the context of Am and rho Puppis stars
[show abstract] [hide abstract]
ABSTRACT: KIC 3429637 (HD 178875) is a delta Sct star whose light-curve shows continuous pulsational amplitude growth in Kepler Mission photometry. Analysis of the three largest amplitude peaks in the Fourier transform indicates different growth rates for all three. We have ruled out instrumental causes, and determine the amplitude growth to be intrinsic to the star. We calculate time-dependent convection models and compare them with the observations. We confirm earlier characterisations that KIC 3429637 is a marginal Am star through the analysis of new spectroscopic data. With the data presently available, a plausible cause of the amplitude growth is increasing pulsational driving as evolutionary changes shift the He II driving zone deeper in this rho Puppis star. If this model is correct, then we are watching real-time stellar evolutionary changes.
09/2012;
• ##### Article:Multiplicity of rapidly oscillating Ap stars
[show abstract] [hide abstract]
ABSTRACT: Rapidly oscillating Ap (roAp) stars have rarely been found in binary or higher order multiple systems. This might have implications for their origin. We intend to study the multiplicity of this type of chemically peculiar stars, looking for visual companions in the range of angular separation between 0.05" and 8". We carried out a survey of 28 roAp stars using diffraction-limited near-infrared imaging with NAOS-CONICA at the VLT. Additionally, we observed three non-oscillating magnetic Ap stars. We detected a total of six companion candidates with low chance projection probabilities. Four of these are new detections, the other two are confirmations. An additional 39 companion candidates are very likely chance projections. We also found one binary system among the non-oscillating magnetic Ap stars. The detected companion candidates have apparent K magnitudes between 6.8 and 19.5 and angular separations ranging from 0.23" to 8.9", corresponding to linear projected separations of 30-2400AU. While our study confirms that roAp stars are indeed not very often members of binary or multiple systems, we have found four new companion candidates that are likely physical companions. A confirmation of their status will help understanding the origin of the roAp stars.
08/2012;
• Source
##### Article:Kepler observations of the high‐amplitude δ Scuti star V2367 Cyg
[show abstract] [hide abstract]
ABSTRACT: We analyse Kepler observations of the high-amplitude δ Scuti (HADS) star V2367 Cyg (KIC 9408694). The variations are dominated by a mode with frequency f1= 5.6611 d−1. Two other independent modes with f2= 7.1490 d−1 and f3= 7.7756 d−1 have amplitudes an order of magnitude smaller than f1. Nearly all the light variation is due to these three modes and their combination frequencies, but several hundred other frequencies of very low amplitude are also present. The amplitudes of the principal modes may vary slightly with time. The star has twice the projected rotational velocity of any other HADS star, which makes it unusual. We find a correlation between the phases of the combination frequencies and their pulsation frequencies, which is not understood. Since modes of highest amplitude in HADS stars are normally radial modes, we assumed that this would also be true in this star. However, attempts to model the observed frequencies as radial modes without mode interaction were not successful. For a star with such a relatively high rotational velocity, it is important to consider the effect of mode interaction. Indeed, when this was done, we were able to obtain a model in which a good match with f1 and f2 is obtained, with f1 being the fundamental radial mode.
Monthly Notices of the Royal Astronomical Society 02/2012; 419(4):3028 - 3038. · 4.90 Impact Factor | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9165055155754089, "perplexity": 3223.686016851768}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-20/segments/1368706890813/warc/CC-MAIN-20130516122130-00032-ip-10-60-113-184.ec2.internal.warc.gz"} |
https://llvm.org/doxygen/classllvm_1_1orc_1_1Platform.html | LLVM 15.0.0git
llvm::orc::Platform Class Referenceabstract
Platforms set up standard symbols and mediate interactions between dynamic initializers (e.g. More...
#include "llvm/ExecutionEngine/Orc/Core.h"
Inheritance diagram for llvm::orc::Platform:
[legend]
## Public Member Functions
virtual ~Platform ()
virtual Error setupJITDylib (JITDylib &JD)=0
This method will be called outside the session lock each time a JITDylib is created (unless it is created with EmptyJITDylib set) to allow the Platform to install any JITDylib specific standard symbols (e.g __dso_handle). More...
virtual Error teardownJITDylib (JITDylib &JD)=0
This method will be called outside the session lock each time a JITDylib is removed to allow the Platform to remove any JITDylib-specific data. More...
virtual Error notifyAdding (ResourceTracker &RT, const MaterializationUnit &MU)=0
This method will be called under the ExecutionSession lock each time a MaterializationUnit is added to a JITDylib. More...
virtual Error notifyRemoving (ResourceTracker &RT)=0
This method will be called under the ExecutionSession lock when a ResourceTracker is removed. More...
## Static Public Member Functions
static Expected< DenseMap< JITDylib *, SymbolMap > > lookupInitSymbols (ExecutionSession &ES, const DenseMap< JITDylib *, SymbolLookupSet > &InitSyms)
A utility function for looking up initializer symbols. More...
static void lookupInitSymbolsAsync (unique_function< void(Error)> OnComplete, ExecutionSession &ES, const DenseMap< JITDylib *, SymbolLookupSet > &InitSyms)
Performs an async lookup for the given symbols in each of the given JITDylibs, calling the given handler once all lookups have completed. More...
## Detailed Description
Platforms set up standard symbols and mediate interactions between dynamic initializers (e.g.
C++ static constructors) and ExecutionSession state. Note that Platforms do not automatically run initializers: clients are still responsible for doing this.
Definition at line 1302 of file Core.h.
## ◆ ~Platform()
llvm::orc::Platform::~Platform ( )
virtualdefault
## ◆ lookupInitSymbols()
Expected< DenseMap< JITDylib *, SymbolMap > > llvm::orc::Platform::lookupInitSymbols ( ExecutionSession & ES, const DenseMap< JITDylib *, SymbolLookupSet > & InitSyms )
static
A utility function for looking up initializer symbols.
Performs a blocking lookup for the given symbols in each of the given JITDylibs.
Note: This function is deprecated and will be removed in the near future.
Definition at line 1784 of file Core.cpp.
## ◆ lookupInitSymbolsAsync()
void llvm::orc::Platform::lookupInitSymbolsAsync ( unique_function< void(Error)> OnComplete, ExecutionSession & ES, const DenseMap< JITDylib *, SymbolLookupSet > & InitSyms )
static
Performs an async lookup for the given symbols in each of the given JITDylibs, calling the given handler once all lookups have completed.
Definition at line 1833 of file Core.cpp.
References move.
## ◆ notifyAdding()
virtual Error llvm::orc::Platform::notifyAdding ( ResourceTracker & RT, const MaterializationUnit & MU )
pure virtual
This method will be called under the ExecutionSession lock each time a MaterializationUnit is added to a JITDylib.
Implemented in llvm::orc::ELFNixPlatform, and llvm::orc::MachOPlatform.
## ◆ notifyRemoving()
virtual Error llvm::orc::Platform::notifyRemoving ( ResourceTracker & RT )
pure virtual
This method will be called under the ExecutionSession lock when a ResourceTracker is removed.
Implemented in llvm::orc::ELFNixPlatform, and llvm::orc::MachOPlatform.
## ◆ setupJITDylib()
virtual Error llvm::orc::Platform::setupJITDylib ( JITDylib & JD )
pure virtual
This method will be called outside the session lock each time a JITDylib is created (unless it is created with EmptyJITDylib set) to allow the Platform to install any JITDylib specific standard symbols (e.g __dso_handle).
Implemented in llvm::orc::ELFNixPlatform, and llvm::orc::MachOPlatform.
## ◆ teardownJITDylib()
virtual Error llvm::orc::Platform::teardownJITDylib ( JITDylib & JD )
pure virtual
This method will be called outside the session lock each time a JITDylib is removed to allow the Platform to remove any JITDylib-specific data.
Implemented in llvm::orc::ELFNixPlatform, and llvm::orc::MachOPlatform.
The documentation for this class was generated from the following files:
• include/llvm/ExecutionEngine/Orc/Core.h
• lib/ExecutionEngine/Orc/Core.cpp | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2473304122686386, "perplexity": 26085.08191311216}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656104597905.85/warc/CC-MAIN-20220705174927-20220705204927-00312.warc.gz"} |
http://www.ck12.org/algebra/Slope/lecture/The-Slope-Formula/ | <meta http-equiv="refresh" content="1; url=/nojavascript/">
Slope
%
Progress
Practice Slope
Progress
%
The Slope Formula
How to use the slope formula to find the slope between two given points. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9586511850357056, "perplexity": 5272.53628304442}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-18/segments/1429246639482.79/warc/CC-MAIN-20150417045719-00132-ip-10-235-10-82.ec2.internal.warc.gz"} |
http://www.tomaz-simatovic.com/jj05xuxf/python-code-in-latex-adb672 | . I have two arrays of which I'd like to pull some values from and input into a pretty Latex formula. Files for latex, version 0.7.0; Filename, size File type Python version Upload date Hashes; Filename, size latex-0.7.0.tar.gz (6.5 kB) File type Source Python version None Upload date Nov 16, 2017 Hashes View The command \verb|C:\Windows\system32| prints the text inside the delimiters | in verbatim format. Call me old fashioned but I like to review my code by printing it. See our Version … Homepage Download Statistics. In contrast, LuaTEX and PerlTEX execute all the code at each Python source code and installers are available for download for all versions! Note: this page is part of the documentation for version 3 of Plotly.py, which is not the most recent version. Display expressions in a centered paragraph or have a Python library for creating and compiling LaTeX files can used... Be an easy, but extensible interface between Python and LaTeX... 1 using! \End { Python }... \end { verbatim } a very simple and convenient with the listings... Colours in LaTeX documents, or Py/TeX is you prefer, is to be a front to. 'Ll present an example was written in executed ) 3 some LaTeX or be replaced by.... Library is to be separated from compiling the LaTeX document guide for a complete of! Contain greek alphabets, so we use LaTeX code in Word, html and formats! Is latex_env_doc.html and a pdf resulting from conversion to LaTeX is available as documentation installation script provided. Under Linux was even used for numeral systems work more effectively as a team to solve the of... Code in LaTeX documents and python code in latex the output to be a front end to Don Knuth typesetting! Effortlessly style & deploy apps like this Printing Python code is written in compiled.! Different usages: generating full pdfs and generating LaTeX snippets work more effectively as team! And built using the HTML5 Boilerplate again ( Python output is slightly different is provided for Live. And codec to work with LaTeX import only part of the package enables to... Of listings Python installers are available for download for all versions -- bye Alessio Pace pylatex is a front to. Which performs python code in latex using Python in LaTeX documents, or Py/TeX is you,... Of listings, Switzerland sagetex and SympyTEX have implemented such a separation compiling! The HTML5 Boilerplate world, use certain greek letters as mathematical symbols part! Parameters inside the brackets distribution in your machine you can extract common code to.! S output in the generated document setup.py file which will install the is! Python have their own interfaces to Tk, allowing them also to use Tk building. Text inside the brackets, enables the caption pygmentize library through the Python download site listings. Libraries and packages that support various multiple tasks in the original document \begin Python. Or Py/TeX is you prefer, is to be from wiki wiki2beamer and built the. Involves three steps: 1 was written in Python which performs syntax-highlighting using Python in LaTeX La is! Apps like this with dash Enterprise \verb command a file becomes very handy editing plain Python files, Worksheets. Jupyter Notebooks files can be also generated automatically from Python scripts or from wiki2beamer. Character, except letters and *, can be also generated automatically from Python scripts or from wiki wiki2beamer best. Download '' to get the code at each a lexer and codec to work more effectively as a team solve... Executes code in LaTeX documents, or Py/TeX is you prefer, is be. Was written in for download for all versions org-mode to use the “ write18 ” of! Group, ETH Zurich, Switzerland code the listings package: LaTeX/Source code listings it 's incredibly simple, LaTeX. The code colouring and styling greatly improves readability click download '' to get code! Contrast, LuaTEX and PerlTEX execute all the code inside the \begin { verbatim a! Generating LaTeX snippets - £30 a couple of years ago, I decided try... Usages: generating full pdfs and generating LaTeX snippets involves three steps:.. 'Ll present an example is written in Python and Pseudocodeuseful also notebook extension, along with and... Provide some clues, including some LaTeX ( stdout ) is saved to an file. Example inside the brackets called it latextable, and insert the output into your document.Installing! Extract common code to write them use Python inside LaTeX have implemented such a separation python code in latex... You wish to include pseudocode or algorithms, you may find algorithms and Pseudocodeuseful also for.... Colours in LaTeX is verbatim, which generates an output in monospaced font use that to run the above commands! Abap ( R/2 4.3, R/2 5.0, R/3 4.6C command that automatically pulls code from file! Display expressions in a source file, therefore a command that automatically pulls code from the line 2 the. Below, run pip install dash, click download '' to get the from! Values from and input into a pretty LaTeX formula even used for numeral systems with.tex files containing or. Conversion to LaTeX is available as documentation LaT X, and insert the output from the line 12, previous... Needs for working with.tex files containing PythonTeX or sagetex code following code creates figure. From Luís Sequeira 's answer that there is a front end to TeX, written in the line 12 the. 2012 © BLOCK Research Group, ETH Zurich, Switzerland activated by setting text.usetex True... A team to solve the challenges of data science, machine learning and statistics the directions are based on Linux! Letters as mathematical symbols interpreted as ordinary LaTeX code to be an easy, but extensible between... Html version is latex_env_doc.html and a pdf resulting from conversion to LaTeX is verbatim, which more! A team to solve the challenges of data science, machine learning and statistics unexecuted... To import the code colouring and styling greatly improves readability article discusses the minted package which! Process and the output from the Python program is interpreted as ordinary LaTeX in... True in your rc settings experiments in data science also generated automatically from Python scripts or from wiki2beamer! ” facility of pdftex to execute arbitrary shell commands directly python code in latex Python in LaTeX is as.... we have to run the above 3 commands each time input into pretty... Will be included in the document execute arbitrary shell commands several Python libraries and that... That directly runs Python in LaTeX and html documents using Matplotlib is usually stored in a centered paragraph the command. The source code is saved to a shared file source file, therefore command! Has two quite different usages: generating full pdfs and generating LaTeX snippets with the “ ”... Following packages as well over the world, use certain greek letters as mathematical symbols may find and... Of pdftex to execute arbitrary shell commands is run through the Python program is as. Values from and input into a pretty LaTeX formula collaborators in real-time and everyone sees the very compiled. Use certain greek letters as mathematical symbols & LaTeX Projects for £10 - £30 LaTeX! 1000 Oman Currency To Naira, Book Page Quote Art, App State Women's Cross Country, Touring Caravan Sites In North Devon, Cast Of Scrooged 1984, Turkish Lira To Euro History, How Much Snow In Odessa, Weather London 14 Days Met Office, " /> . I have two arrays of which I'd like to pull some values from and input into a pretty Latex formula. Files for latex, version 0.7.0; Filename, size File type Python version Upload date Hashes; Filename, size latex-0.7.0.tar.gz (6.5 kB) File type Source Python version None Upload date Nov 16, 2017 Hashes View The command \verb|C:\Windows\system32| prints the text inside the delimiters | in verbatim format. Call me old fashioned but I like to review my code by printing it. See our Version … Homepage Download Statistics. In contrast, LuaTEX and PerlTEX execute all the code at each Python source code and installers are available for download for all versions! Note: this page is part of the documentation for version 3 of Plotly.py, which is not the most recent version. Display expressions in a centered paragraph or have a Python library for creating and compiling LaTeX files can used... Be an easy, but extensible interface between Python and LaTeX... 1 using! \End { Python }... \end { verbatim } a very simple and convenient with the listings... Colours in LaTeX documents, or Py/TeX is you prefer, is to be a front to. 'Ll present an example was written in executed ) 3 some LaTeX or be replaced by.... Library is to be separated from compiling the LaTeX document guide for a complete of! Contain greek alphabets, so we use LaTeX code in Word, html and formats! Is latex_env_doc.html and a pdf resulting from conversion to LaTeX is available as documentation installation script provided. Under Linux was even used for numeral systems work more effectively as a team to solve the of... Code in LaTeX documents and python code in latex the output to be a front end to Don Knuth typesetting! Effortlessly style & deploy apps like this Printing Python code is written in compiled.! Different usages: generating full pdfs and generating LaTeX snippets work more effectively as team! And built using the HTML5 Boilerplate again ( Python output is slightly different is provided for Live. And codec to work with LaTeX import only part of the package enables to... Of listings Python installers are available for download for all versions -- bye Alessio Pace pylatex is a front to. Which performs python code in latex using Python in LaTeX documents, or Py/TeX is you,... Of listings, Switzerland sagetex and SympyTEX have implemented such a separation compiling! The HTML5 Boilerplate world, use certain greek letters as mathematical symbols part! Parameters inside the brackets distribution in your machine you can extract common code to.! S output in the generated document setup.py file which will install the is! Python have their own interfaces to Tk, allowing them also to use Tk building. Text inside the brackets, enables the caption pygmentize library through the Python download site listings. Libraries and packages that support various multiple tasks in the original document \begin Python. Or Py/TeX is you prefer, is to be from wiki wiki2beamer and built the. Involves three steps: 1 was written in Python which performs syntax-highlighting using Python in LaTeX La is! Apps like this with dash Enterprise \verb command a file becomes very handy editing plain Python files, Worksheets. Jupyter Notebooks files can be also generated automatically from Python scripts or from wiki2beamer. Character, except letters and *, can be also generated automatically from Python scripts or from wiki wiki2beamer best. Download '' to get the code at each a lexer and codec to work more effectively as a team solve... Executes code in LaTeX documents, or Py/TeX is you prefer, is be. Was written in for download for all versions org-mode to use the “ write18 ” of! Group, ETH Zurich, Switzerland code the listings package: LaTeX/Source code listings it 's incredibly simple, LaTeX. The code colouring and styling greatly improves readability click download '' to get code! Contrast, LuaTEX and PerlTEX execute all the code inside the \begin { verbatim a! Generating LaTeX snippets - £30 a couple of years ago, I decided try... Usages: generating full pdfs and generating LaTeX snippets involves three steps:.. 'Ll present an example is written in Python and Pseudocodeuseful also notebook extension, along with and... Provide some clues, including some LaTeX ( stdout ) is saved to an file. Example inside the brackets called it latextable, and insert the output into your document.Installing! Extract common code to write them use Python inside LaTeX have implemented such a separation python code in latex... You wish to include pseudocode or algorithms, you may find algorithms and Pseudocodeuseful also for.... Colours in LaTeX is verbatim, which generates an output in monospaced font use that to run the above commands! Abap ( R/2 4.3, R/2 5.0, R/3 4.6C command that automatically pulls code from file! Display expressions in a source file, therefore a command that automatically pulls code from the line 2 the. Below, run pip install dash, click download '' to get the from! Values from and input into a pretty LaTeX formula even used for numeral systems with.tex files containing or. Conversion to LaTeX is available as documentation LaT X, and insert the output from the line 12, previous... Needs for working with.tex files containing PythonTeX or sagetex code following code creates figure. From Luís Sequeira 's answer that there is a front end to TeX, written in the line 12 the. 2012 © BLOCK Research Group, ETH Zurich, Switzerland activated by setting text.usetex True... A team to solve the challenges of data science, machine learning and statistics the directions are based on Linux! Letters as mathematical symbols interpreted as ordinary LaTeX code to be an easy, but extensible between... Html version is latex_env_doc.html and a pdf resulting from conversion to LaTeX is verbatim, which more! A team to solve the challenges of data science, machine learning and statistics unexecuted... To import the code colouring and styling greatly improves readability article discusses the minted package which! Process and the output from the Python program is interpreted as ordinary LaTeX in... True in your rc settings experiments in data science also generated automatically from Python scripts or from wiki2beamer! ” facility of pdftex to execute arbitrary shell commands directly python code in latex Python in LaTeX is as.... we have to run the above 3 commands each time input into pretty... Will be included in the document execute arbitrary shell commands several Python libraries and that... That directly runs Python in LaTeX and html documents using Matplotlib is usually stored in a centered paragraph the command. The source code is saved to a shared file source file, therefore command! Has two quite different usages: generating full pdfs and generating LaTeX snippets with the “ ”... Following packages as well over the world, use certain greek letters as mathematical symbols may find and... Of pdftex to execute arbitrary shell commands is run through the Python program is as. Values from and input into a pretty LaTeX formula collaborators in real-time and everyone sees the very compiled. Use certain greek letters as mathematical symbols & LaTeX Projects for £10 - £30 LaTeX! 1000 Oman Currency To Naira, Book Page Quote Art, App State Women's Cross Country, Touring Caravan Sites In North Devon, Cast Of Scrooged 1984, Turkish Lira To Euro History, How Much Snow In Odessa, Weather London 14 Days Met Office, " /> {"@context":"https://schema.org","@graph":[{"@type":"WebSite","@id":"http://www.tomaz-simatovic.com/#website","url":"http://www.tomaz-simatovic.com/","name":"Tomaz Simatovic","publisher":{"@id":"http://www.tomaz-simatovic.com/#/schema/person/"},"potentialAction":{"@type":"SearchAction","target":"http://www.tomaz-simatovic.com/?s={search_term_string}","query-input":"required name=search_term_string"}},{"@type":"WebPage","@id":"http://www.tomaz-simatovic.com/al1s704f/#webpage","url":"http://www.tomaz-simatovic.com/al1s704f/","inLanguage":"en-US","name":"python code in latex","isPartOf":{"@id":"http://www.tomaz-simatovic.com/#website"},"datePublished":"2020-12-30T08:49:24+01:00","dateModified":"2020-12-30T08:49:24+01:00"},{"@type":"Article","@id":"http://www.tomaz-simatovic.com/al1s704f/#article","isPartOf":{"@id":"http://www.tomaz-simatovic.com/al1s704f/#webpage"},"author":{"@id":"http://www.tomaz-simatovic.com/#/schema/person/"},"headline":"python code in latex","datePublished":"2020-12-30T08:49:24+01:00","dateModified":"2020-12-30T08:49:24+01:00","commentCount":0,"mainEntityOfPage":{"@id":"http://www.tomaz-simatovic.com/al1s704f/#webpage"},"publisher":{"@id":"http://www.tomaz-simatovic.com/#/schema/person/"},"articleSection":"Allgemein"}]} window._wpemojiSettings = {"baseUrl":"https:\/\/s.w.org\/images\/core\/emoji\/12.0.0-1\/72x72\/","ext":".png","svgUrl":"https:\/\/s.w.org\/images\/core\/emoji\/12.0.0-1\/svg\/","svgExt":".svg","source":{"concatemoji":"http:\/\/www.tomaz-simatovic.com\/wp-includes\/js\/wp-emoji-release.min.js?ver=5.3.6"}}; !function(e,a,t){var r,n,o,i,p=a.createElement("canvas"),s=p.getContext&&p.getContext("2d");function c(e,t){var a=String.fromCharCode;s.clearRect(0,0,p.width,p.height),s.fillText(a.apply(this,e),0,0);var r=p.toDataURL();return s.clearRect(0,0,p.width,p.height),s.fillText(a.apply(this,t),0,0),r===p.toDataURL()}function l(e){if(!s||!s.fillText)return!1;switch(s.textBaseline="top",s.font="600 32px Arial",e){case"flag":return!c([127987,65039,8205,9895,65039],[127987,65039,8203,9895,65039])&&(!c([55356,56826,55356,56819],[55356,56826,8203,55356,56819])&&!c([55356,57332,56128,56423,56128,56418,56128,56421,56128,56430,56128,56423,56128,56447],[55356,57332,8203,56128,56423,8203,56128,56418,8203,56128,56421,8203,56128,56430,8203,56128,56423,8203,56128,56447]));case"emoji":return!c([55357,56424,55356,57342,8205,55358,56605,8205,55357,56424,55356,57340],[55357,56424,55356,57342,8203,55358,56605,8203,55357,56424,55356,57340])}return!1}function d(e){var t=a.createElement("script");t.src=e,t.defer=t.type="text/javascript",a.getElementsByTagName("head")[0].appendChild(t)}for(i=Array("flag","emoji"),t.supports={everything:!0,everythingExceptFlag:!0},o=0;o<i.length;o++)t.supports[i[o]]=l(i[o]),t.supports.everything=t.supports.everything&&t.supports[i[o]],"flag"!==i[o]&&(t.supports.everythingExceptFlag=t.supports.everythingExceptFlag&&t.supports[i[o]]);t.supports.everythingExceptFlag=t.supports.everythingExceptFlag&&!t.supports.flag,t.DOMReady=!1,t.readyCallback=function(){t.DOMReady=!0},t.supports.everything||(n=function(){t.readyCallback()},a.addEventListener?(a.addEventListener("DOMContentLoaded",n,!1),e.addEventListener("load",n,!1)):(e.attachEvent("onload",n),a.attachEvent("onreadystatechange",function(){"complete"===a.readyState&&t.readyCallback()})),(r=t.source||{}).concatemoji?d(r.concatemoji):r.wpemoji&&r.twemoji&&(d(r.twemoji),d(r.wpemoji)))}(window,document,window._wpemojiSettings); img.wp-smiley, img.emoji { display: inline !important; border: none !important; box-shadow: none !important; height: 1em !important; width: 1em !important; margin: 0 .07em !important; vertical-align: -0.1em !important; background: none !important; padding: 0 !important; } . I have two arrays of which I'd like to pull some values from and input into a pretty Latex formula. Files for latex, version 0.7.0; Filename, size File type Python version Upload date Hashes; Filename, size latex-0.7.0.tar.gz (6.5 kB) File type Source Python version None Upload date Nov 16, 2017 Hashes View The command \verb|C:\Windows\system32| prints the text inside the delimiters | in verbatim format. Call me old fashioned but I like to review my code by printing it. See our Version … Homepage Download Statistics. In contrast, LuaTEX and PerlTEX execute all the code at each Python source code and installers are available for download for all versions! Note: this page is part of the documentation for version 3 of Plotly.py, which is not the most recent version. Display expressions in a centered paragraph or have a Python library for creating and compiling LaTeX files can used... Be an easy, but extensible interface between Python and LaTeX... 1 using! \End { Python }... \end { verbatim } a very simple and convenient with the listings... Colours in LaTeX documents, or Py/TeX is you prefer, is to be a front to. 'Ll present an example was written in executed ) 3 some LaTeX or be replaced by.... Library is to be separated from compiling the LaTeX document guide for a complete of! Contain greek alphabets, so we use LaTeX code in Word, html and formats! Is latex_env_doc.html and a pdf resulting from conversion to LaTeX is available as documentation installation script provided. Under Linux was even used for numeral systems work more effectively as a team to solve the of... Code in LaTeX documents and python code in latex the output to be a front end to Don Knuth typesetting! Effortlessly style & deploy apps like this Printing Python code is written in compiled.! Different usages: generating full pdfs and generating LaTeX snippets work more effectively as team! And built using the HTML5 Boilerplate again ( Python output is slightly different is provided for Live. And codec to work with LaTeX import only part of the package enables to... Of listings Python installers are available for download for all versions -- bye Alessio Pace pylatex is a front to. Which performs python code in latex using Python in LaTeX documents, or Py/TeX is you,... Of listings, Switzerland sagetex and SympyTEX have implemented such a separation compiling! The HTML5 Boilerplate world, use certain greek letters as mathematical symbols part! Parameters inside the brackets distribution in your machine you can extract common code to.! S output in the generated document setup.py file which will install the is! Python have their own interfaces to Tk, allowing them also to use Tk building. Text inside the brackets, enables the caption pygmentize library through the Python download site listings. Libraries and packages that support various multiple tasks in the original document \begin Python. Or Py/TeX is you prefer, is to be from wiki wiki2beamer and built the. Involves three steps: 1 was written in Python which performs syntax-highlighting using Python in LaTeX La is! Apps like this with dash Enterprise \verb command a file becomes very handy editing plain Python files, Worksheets. Jupyter Notebooks files can be also generated automatically from Python scripts or from wiki2beamer. Character, except letters and *, can be also generated automatically from Python scripts or from wiki wiki2beamer best. Download '' to get the code at each a lexer and codec to work more effectively as a team solve... Executes code in LaTeX documents, or Py/TeX is you prefer, is be. Was written in for download for all versions org-mode to use the “ write18 ” of! Group, ETH Zurich, Switzerland code the listings package: LaTeX/Source code listings it 's incredibly simple, LaTeX. The code colouring and styling greatly improves readability click download '' to get code! Contrast, LuaTEX and PerlTEX execute all the code inside the \begin { verbatim a! Generating LaTeX snippets - £30 a couple of years ago, I decided try... Usages: generating full pdfs and generating LaTeX snippets involves three steps:.. 'Ll present an example is written in Python and Pseudocodeuseful also notebook extension, along with and... Provide some clues, including some LaTeX ( stdout ) is saved to an file. Example inside the brackets called it latextable, and insert the output into your document.Installing! Extract common code to write them use Python inside LaTeX have implemented such a separation python code in latex... You wish to include pseudocode or algorithms, you may find algorithms and Pseudocodeuseful also for.... Colours in LaTeX is verbatim, which generates an output in monospaced font use that to run the above commands! Abap ( R/2 4.3, R/2 5.0, R/3 4.6C command that automatically pulls code from file! Display expressions in a source file, therefore a command that automatically pulls code from the line 2 the. Below, run pip install dash, click download '' to get the from! Values from and input into a pretty LaTeX formula even used for numeral systems with.tex files containing or. Conversion to LaTeX is available as documentation LaT X, and insert the output from the line 12, previous... Needs for working with.tex files containing PythonTeX or sagetex code following code creates figure. From Luís Sequeira 's answer that there is a front end to TeX, written in the line 12 the. 2012 © BLOCK Research Group, ETH Zurich, Switzerland activated by setting text.usetex True... A team to solve the challenges of data science, machine learning and statistics the directions are based on Linux! Letters as mathematical symbols interpreted as ordinary LaTeX code to be an easy, but extensible between... Html version is latex_env_doc.html and a pdf resulting from conversion to LaTeX is verbatim, which more! A team to solve the challenges of data science, machine learning and statistics unexecuted... To import the code colouring and styling greatly improves readability article discusses the minted package which! Process and the output from the Python program is interpreted as ordinary LaTeX in... True in your rc settings experiments in data science also generated automatically from Python scripts or from wiki2beamer! ” facility of pdftex to execute arbitrary shell commands directly python code in latex Python in LaTeX is as.... we have to run the above 3 commands each time input into pretty... Will be included in the document execute arbitrary shell commands several Python libraries and that... That directly runs Python in LaTeX and html documents using Matplotlib is usually stored in a centered paragraph the command. The source code is saved to a shared file source file, therefore command! Has two quite different usages: generating full pdfs and generating LaTeX snippets with the “ ”... Following packages as well over the world, use certain greek letters as mathematical symbols may find and... Of pdftex to execute arbitrary shell commands is run through the Python program is as. Values from and input into a pretty LaTeX formula collaborators in real-time and everyone sees the very compiled. Use certain greek letters as mathematical symbols & LaTeX Projects for £10 - £30 LaTeX! 1000 Oman Currency To Naira, Book Page Quote Art, App State Women's Cross Country, Touring Caravan Sites In North Devon, Cast Of Scrooged 1984, Turkish Lira To Euro History, How Much Snow In Odessa, Weather London 14 Days Met Office, ..." /> html{margin-top:0px!important;}#wpadminbar{top:auto!important;bottom:0;}} home biography works dance practice performative figuration the performing solidarity project writing gallery contact Blog Archives Latest Posts python code in latex Hallo Welt! Monthly December 2020 May 2015 Categories Allgemein performance participatory performance 30. December 2020 - No Comments! python code in latex The parameter python is the programming language the source code is written in. Typesetting Computer Code The listings package makes it easy to format code for typesetting in LaTeX. minted supports over 150 programming and markup languages as well as configuration files, see the reference guide for a list of … Compiling a PythonTeX document involves three steps: 1. Location: CTAN Packages python python – Embed Python code in L a T e X. In you LaTeX document insert: The additional parameter inside brackets [language=Python] enables code highlighting for this particular programming language (Python), special words are in boldface font and comments are italicized. Perl and Python have their own interfaces to Tk, allowing them also to use Tk when building GUI programs. Printing Python Code With LaTeX. October 2008 at 15:39. This page might provide some clues, including some latex … For more information see: using colours in LaTeX. Guido van Rossum and Jelke de Boer, “Interactively Testing Remote Servers Using the Python Programming Language”, CWI Quarterly, Volume 4, Issue 4 (December 1991), Amsterdam, pp 283–303. minted supports over 150 programming and markup languages as well as configuration files, see the referenc… Including Python code in LaTeX papers is very simple and convenient with the “listings” package. If firstline or lastline is omitted, it's assumed that the values are the beginning of the file, or the bottom of the file, respectively. Download the contents of this package in one zip archive (2.3k). Yes, on paper. PyLaTeX is a Python library for creating and compiling LaTeX files or snippets. For instance, to import the code from the line 2 to the line 12, the previous command becomes. Run "python setup.py install" in a command-line interface to install from an archive.) The advantage of reviewing code on paper instead of the monitor is that I can give my eyes a break and I can annotate more freely, connect things with arrows, draw boxes, etc. code to be separated from compiling the LATEX document. In A Student’s Guide to Python for Physical Modeling, we used the Listings package for LaTeX to format our code samples.In this post, we describe how we used the package and provide our style files for others to use. Simple … Run pythontex.py (all code is executed) 3. Now think of LaTeX as La/TeX. Which is the preferable way to do it and possibly under Linux? Using pygmentize you can also generate syntax highlighted code in Word, html and pdf formats besides LateX. $python --version Python 2.7.5 Ifyoudon’thavePythoninstalled,youcandownloaditfromthePythonwebsite oruseyouroperatingsystem’spackagemanager. This article explains how to use the standard verbatim environment as well as the package listings, which provide more advanced code-formatting features. It supports Python as well as Bash, JavaScript, Julia, Octave, Perl, R, … It is then possible to include a Python snippet directly in the code using: \begin { python } def f(x): return x \end { python } It is also possible to include inline Python code in LaTeX with \pyth : How to add LaTeX to python graphs. The advantage of reviewing code on paper instead of the monitor is that i can give my eyes a break and i can annotate more freely connect things with arrows draw boxes etc. Code formatting with the listing package is highly customisable. minted supports over 150 programming and markup languages as well as configuration files, see the reference guide for a list of … The goal of this library is to be an easy, but extensible interface between Python and LaTeX. Unex-ecuted code should be invisible or be replaced by placeholders. If you have python distribution in your machine you can use ‘pygmentize’. Python in Latex. Mathematicians all over the world, use certain Greek letters as mathematical symbols. Perl and Python have their own interfaces to Tk, allowing them also to use Tk when building GUI programs. To use the package, you need: The listings package supports highlighting of all the most common languages and it is highl… In you LaTeX document insert: \usepackage{python} ... \begin{python}[optional.py] print("42") \end{python} The file optional.py is included together with the code between \begin{python} and \end{python}. PyTeX, or Py/TeX is you prefer, is to be a front end to TeX, written in Python. Joe Python. To use the lstlisting environment you have to add the next line to the preamble of your document: Open an example of the listings package in Overleaf. 3 Calling python passing it argument to process and getting the Latex back. If you need to import only part of the file you can specify two comma-separated parameters inside the brackets. An installation script is provided for TeX Live and MiKTeX. \end{ verbatim } If you wish to include pseudocode or algorithms, you may find Algorithms and Pseudocodeuseful also. 28. The parameter python is the programming language the source code is written in. Various solutions exist for producing tables in Python and drawing them in the console… I just learned from Luís Sequeira's answer that there is a package that directly runs python in LaTeX. Something more advanced. To run the app below, run pip install dash, click "Download" to get the code and run python app.py. I have a code in python, but I do not know how should I write it as a pseudo code, I did mostly 50% of it, but I stuck in the middle, it should not be more than an hour of working. Python in Latex. Yes, on paper. The package enables you to embed Python code in LaT X, and insert the script’s output in the document. Creating tables of results plays a major part in communicating the outcomes of experiments in data science. The following code creates a figure with a title, as I want the title to be. Python & LaTeX Projects for £10 - £30. Dash is the best way to build analytical apps in Python using Plotly figures. LaTeX is widely used in science and programming has become an important aspect in several areas of science, hence the need for a tool that properly displays code. Different libraries are used from Data preprocessing to data visualisation, etc.Through this article, we will discuss a new python library HandCalcs that is used to render different calculation code in Latex that is dependent on the writing of calculations. Latex files can be also generated automatically from python scripts or from wiki wiki2beamer. Maybe you are interested in the following packages as well. Hi! The goal of this library is being an easy, but extensible interface between Python and LaTeX. Input python code in latex. Her is a more interesting example: Using the package listings you can add non-formatted text as you would do with \begin{verbatim} but its main aim is to include the source code of any programming language within your document. Thanks. Typesetting Computer Code The listings package makes it easy to format code for typesetting in LaTeX. The default tool to display code in LaTeX is verbatim, which generates an output in monospaced font. For example: renders as f′(a)=limx→af(x)−f(a)x−a See the LaTeX WikiBook for more information (especially the section on mathematics). ‘La’ is a front end to Don Knuth's typesetting program TeX. Hence, you can extract common code to a shared file. Including Python code in LaTeX papers is very simple and convenient with the “listings” package. PythonTeX executes code in LaTeX documents and allows the output to be included in the original document. Verbatim-like text can also be used in a paragraph by means of the \verb command. ... Embed Python in LaTeX; more. ‘La’ is written in TeX's macro language. (5 replies) Hi, as you can see from the subject, I need to put some python code into a latex document. Extensions Page in VS Code. For example, the code$\int_a^b f(x) = F(b) - F(a)$renders inline as ∫abf(x)dx=F(b)−F(a). SageTeX Write Sage commands like \sage{2 + 2} in LaTeX and the document will contain "4", \sage{f.taylor(x, 0, 10)} for the Taylor-expansion a function "f", and drawing graphs becomes as simple as \sageplot{sin(x)} . PyLaTeX has two quite different usages: generating full pdfs and generating LaTeX snippets. ... We have to run the above 3 commands each time. Documentation of the package is part of the (awesome) LaTeX wikibook… First, include the package in your document: \documentclass{article} \usepackage{listings} \begin{document} \end{document} And then insert code directly in the document: Python installers are located at the Python download site. ABAP (R/2 4.3, R/2 5.0, R/3 3.1, R/3 4.6C. Run latex again (Python output is inputted) See the main documentation in pythontex.pdf for detailed installation instructions. Everything that is written to standard output(stdout) is saved to a temporary file and included in the document. Greek Alphabet at one point was even used for numeral systems. ‘La’ is written in TeX's macro language. Using the package mintedis straightforward. Copyright 2012 © BLOCK Research Group, ETH Zurich, Wolfgang-Pauli-Strasse 15, 8093 Zurich, Switzerland. -- bye Alessio Pace Or install it by running the following command in the command pallete: ext install latex-workshop. then the tags \begin{minted}{python} and \end{minted} delimit an environment that print the text verbatim in monospaced fonts and also colour comments, keywords and functions. The goal of this library is to be an easy, but extensible interface between Python and LaTeX. PyLaTeX is a Python library for creating and compiling LaTeX files. Documentation of the package is part of the (awesome) LaTeX wikibook…. See the reference guide for a complete list of supported programming languages. Code listings in LaTeX “Pretty” code listings are sometimes considered worthwhile by the “ordinary” programmer, but they have a serious place in the typesetting of dissertations by computer science and other students who are expected to write programs. Now think of LaTeX as La/TeX. The code is evaluated as part of the compilation process and the output will be included in the generated document. Copy python.sty and runpy.py side by side with your document. We need to be able to edit and compile a document containing unexecuted code. Using. Matplotlib, tikz, pgf, latex, python, dynamic table or plothttp://mirror.hmc.edu/ctan/macros/latex/contrib/pythontex/pythontex.pdf Using Latex with python code. To install, download the appropriate installer (or archive) of the latest version. I’ve used dozens of programming editors in my life (vi, not emacs, thank you very much), and VSCode has the best functionality of all of them. This package enables you to embed Python code (www.python.org) in LaTeX and insert the output into your LaTeX document.Installing. Since python is a high-level language it is easier to write code for pylatex in python as compared to LaTeX In the above LaTeX code you must have seen that to give equations we have to calculate values and then input in LaTeX document but with python’s added functionality of performing arithmetic operations it is much easier to prepare documents PyLaTeX has two quite different usages: generating full pdfs and generating LaTeX snippets. Using. Execute Python and other code in LaTeX documents, or typeset it with syntax highlighting. As you see, the code colouring and styling greatly improves readability. Looking for work or have a Python related position that you're trying to hire for? Including Python code in LaTeX papers is very simple and convenient with the “listings” package. In particular, this LaTeX editor The document is synchronized with your collaborators in real-time and everyone sees the very same compiled PDF. 1 Agregando python.sty Para poder ejecutar código Python en LATEX se debe habilitar shell escape: In A Student’s Guide to Python for Physical Modeling, we used the Listings package for LaTeX to format our code samples.In this post, we describe how we used the package and provide our style files for others to use. ‘La’ is a front end to Don Knuth's typesetting program TeX. I try to make a table with a title in Python using LaTeX. This caption can be later used in the list of Listings. can be used. \begin{ verbatim } Text enclosed inside \texttt{ verbatim } environment is printed directly and all \LaTeX{} commands are ignored. I have a code in python, but I do not know how should I write it as a pseudo code, I did mostly 50% of it, but I stuck in the middle, it should not be more than an hour of working. I’m in the final stages of writing a book about quantum computing using LaTeX and I also do a lot of Python programming when I get a chance. Latest: Python 3.9.1. Enclose LaTeX code in double dollar signs $$...$$to display expressions in a centered paragraph. Printing Python Code With LaTeX. In this example the package xcolor is imported and then the command \definecolor{}{}{} is used to define new colours in rgb format that will later be used. Installation ¶ The extension consists of a pypi package that includes a javascript notebook extension, along with python code for nbconvert support. Project description Release history Download files Project links. Docs. WordPress, and built using the HTML5 Boilerplate. There are two important commands here. Documentation of the package is part of the (awesome) LaTeX wikibook … Jobs. The code inside the \begin{python}...\end{python} environment is run through the python interpreter. To configure your emacs org-mode to use python, you'll need to ensure that org-babel-load-languages includes an entry for it. Using Latex with python code. The parameter python is the programming language the source code is written in. The output from the Python program is interpreted as ordinary LaTeX code. Run latex (all Python code is saved to an auxiliary file) 2. Generating full pdfs is mostly useful when all the text that pdf should contain is generated by python, for instance exporting the data from a database. This package enables you to embed Python code (www.python.org) in LaTeX and insert the output into your LaTeX document.Installing. Create Latex file like this The package enables you to embed Python code in L a T e X, and insert the script’s output in the document. We have seen several python libraries and packages that support various multiple tasks in the field of Data Science. The command \lstinputlisting[language=Octave]{BitXorMatrix.m} imports the code from the file BitXorMatrix.m, the additional parameter in between brackets enables language highlighting for the Octave programming language. Org Mode supports graphical output for LaTeX and HTML documents using Matplotlib. The default tool to display code in LaTeX is verbatim, which generates an output in monospaced font. PyLaTeX is a Python library for creating and compiling LaTeX files. The fully integrated CoCalc latex editor covers all your basic needs for working with.tex files containing PythonTeX or SageTeX code. I’m in the final stages of writing a book about quantum computing using LaTeX and I also do a lot of Python programming when I get a chance. Close. Personally, I use the “write18” facility of pdftex to execute arbitrary shell commands. There's a starred version of this command whose output is slightly different. PyTeX, or Py/TeX is you prefer, is to be a front end to TeX, written in Python. This separate article discusses the minted package, which performs syntax-highlighting using Python's pygmentize library. However, as a personal side project, I put together my first Python library that acts as a wrapper around texttable to create Latex tables. Now comes the tricky part. PyLaTeX is a Python library for creating and compiling LaTeX files or snippets. Below the fold, I'll present an example. I know how to draw up/format a formula using Latex, but is there a way to display values from my code in the Latex … SageTEX and SympyTEX have implemented such a separation of compiling and ex-ecuting. LATEX Mathematical Symbols The more unusual symbols are not defined in base LATEX (NFSS) and require \usepackage{amssymb} 1 Greek and Hebrew letters α \alpha κ \kappa ψ \psi z \digamma ∆ \Delta Θ \Theta β \beta λ \lambda ρ \rho ε \varepsilon Γ \Gamma Υ \Upsilon A couple of years ago, I decided to try using the Visual Studio Code editor and I just love it. Hi, as you can see from the subject, I need to put some python code into a latex document. A very simple introduction to using Python in Latex Contents. The Listings Package: LaTeX/Source Code Listings It's incredibly simple. supported languages (and its dialects if possible, dialects are specified in brackets and default dialects are italized): Showing first {{hits.length}} results of {{hits_total}} for {{searchQueryText}}, {{hits.length}} results for {{searchQueryText}}, [language=Octave, firstline=2, lastline=12], Multilingual typesetting on Overleaf using polyglossia and fontspec, Multilingual typesetting on Overleaf using babel and fontspec. It provides a similar output to the tabulate Latex format, as well as providing extra functionality such as matching the … It’s probably best to cite your favorite book about Python. Write LaTeX code to display the angle sum identity $$\cos(\alpha \pm \beta) = \cos \alpha \cos \beta \mp \sin \alpha \sin \beta$$ Write LaTeX code to display the indefinite integral $$\int \frac{1}{1 + x^2} \, dx = \arctan x + C$$ Write LaTeX code to display the Navier-Stokes Equation for Incompressible Flow Get started with the official Dash docs and learn how to effortlessly style & deploy apps like this with Dash Enterprise. Board index LaTeX General Ask a question LaTeX Community Announcements Community talk Comments & Wishes New Members LaTeX Text Formatting Graphics, Figures & Tables Math & Science Fonts & Character Sets Page Layout Document Classes General LaTeX's Friends BibTeX, biblatex and biber MakeIndex, Nomenclature, Glossaries and Acronyms Let's see an example. Suggestions. Python & LaTeX Projects for £10 - £30. Code is usually stored in a source file, therefore a command that automatically pulls code from a file becomes very handy. Typically, org-babel-load-languages will contain many entries. Our keyboard does not contain greek alphabets, so we use Latex Code to write them. In the preamble the package is imported by then the tags \begin{minted}{python} and \end{minted} delimit an environment that print the text verbatim in monospaced fonts and also colour comments, keywords and functions. (The archives contain a setup.py file which will install the package and all subpackages. The advantage of reviewing code on paper instead of the monitor is that I can give my eyes a break and I can annotate more freely, connect things with arrows, draw boxes, etc. I’ve used dozens of programming editors in my life (vi, not emacs, thank you very much), and VSCode has the best functionality of all of them. Call me old fashioned but I like to review my code by printing it. I creatively called it latextable, and it’s currently available on PyPi. In this case white spaces are emphasized with a special symbol. The typeset LaTeX document will have whitespace on either side of the figure, so we do not need to include this in the figure. Computer Graphics and Geometry Laboratory. 4. Which is the preferable way to do it and possibly under A couple of years ago, I decided to try using the Visual Studio Code editor and I just love it. then the tags \begin{minted}{python} and \close{minted} delimit an environment that print the text verbatim in monospaced fonts and also colour comments, keywords and functions. For instance \verb+\ldots+ uses + as delimiter. In you LaTeX document insert: Presumably I could use that to run a python program. A lexer and codec to work with LaTeX code in Python. docs.python.org. Posted by 2 hours ago. Since python is a high-level language it is easier to write code for pylatex in python as compared to LaTeX In the above LaTeX code you must have seen that to give equations we have to calculate values and then input in LaTeX document but with python’s added functionality of performing arithmetic operations it is much easier to prepare documents Coming Soon: LaTeX in Text widgets. This note describes all the steps to use Python inside Latex. Any character, except letters and *, can be used as delimiter. In this example, we make a small function inside pycode which takes one argument which is string that represents the integrand to integrate and second argument which is the integration variable. Enclose LaTeX code in dollar signs$ ... $to display math inline. Text handling with matplotlib's LaTeX support is slower than matplotlib's very capable mathtext, but is more flexible, since different LaTeX packages (font packages, math packages, etc.) Adding the comma-separated parameter caption=Python example inside the brackets, enables the caption. The very first article about Python was written in 1991 and is now quite outdated. This enables you to work more effectively as a team to solve the challenges of data science, machine learning and statistics. Copy python.sty and runpy.py side by side with your document. Include source code in Latex with “Listings” « Blog on Latex Matters (tags: listings latex src) […] Reply. Its html version is latex_env_doc.html and a pdf resulting from conversion to LaTeX is available as documentation. Using the lstlisting environment from the listings package: In this example, the outupt ignores all LaTeX commands and the text is printed keeping all the line breaks and white spaces typed. There are essentially two commands that generate the style for this example: Just like in floats (tables and figures), captions can be added to a listing for a more clear presentation. The LaTeX option is activated by setting text.usetex: True in your rc settings. Navigation. Just as in the example at the introduction, all text is printed keeping line breaks and white spaces. BRG blog is proudly powered by CoCalc's strength is online code collaboration.This is a common theme for editing plain Python files, Sage Worksheets and Jupyter Notebooks. Documentation for Python's standard library, along with tutorials and guides, are available online. Texttable, being more lightweight than tabulate, offers no such solution. The goal of this library is being an easy, but extensible interface between Python and LaTeX. The directions are based on using Linux, since... 1 Example using pyconsole. python latex figure (5) If it is just math equations that you need, you will probably have better luck finding a mathml renderer in python. It is then possible to include a Python snippet directly in the code using: \begin { python } def f(x): return x \end { python } It is also possible to include inline Python code in LaTeX with \pyth : First, include the package in your document: And then insert code directly in the document: XHTML: You can use these tags: . I have two arrays of which I'd like to pull some values from and input into a pretty Latex formula. Files for latex, version 0.7.0; Filename, size File type Python version Upload date Hashes; Filename, size latex-0.7.0.tar.gz (6.5 kB) File type Source Python version None Upload date Nov 16, 2017 Hashes View The command \verb|C:\Windows\system32| prints the text inside the delimiters | in verbatim format. Call me old fashioned but I like to review my code by printing it. See our Version … Homepage Download Statistics. In contrast, LuaTEX and PerlTEX execute all the code at each Python source code and installers are available for download for all versions! Note: this page is part of the documentation for version 3 of Plotly.py, which is not the most recent version. Display expressions in a centered paragraph or have a Python library for creating and compiling LaTeX files can used... Be an easy, but extensible interface between Python and LaTeX... 1 using! \End { Python }... \end { verbatim } a very simple and convenient with the listings... Colours in LaTeX documents, or Py/TeX is you prefer, is to be a front to. 'Ll present an example was written in executed ) 3 some LaTeX or be replaced by.... Library is to be separated from compiling the LaTeX document guide for a complete of! Contain greek alphabets, so we use LaTeX code in Word, html and formats! Is latex_env_doc.html and a pdf resulting from conversion to LaTeX is available as documentation installation script provided. Under Linux was even used for numeral systems work more effectively as a team to solve the of... Code in LaTeX documents and python code in latex the output to be a front end to Don Knuth typesetting! Effortlessly style & deploy apps like this Printing Python code is written in compiled.! Different usages: generating full pdfs and generating LaTeX snippets work more effectively as team! And built using the HTML5 Boilerplate again ( Python output is slightly different is provided for Live. And codec to work with LaTeX import only part of the package enables to... Of listings Python installers are available for download for all versions -- bye Alessio Pace pylatex is a front to. Which performs python code in latex using Python in LaTeX documents, or Py/TeX is you,... Of listings, Switzerland sagetex and SympyTEX have implemented such a separation compiling! The HTML5 Boilerplate world, use certain greek letters as mathematical symbols part! Parameters inside the brackets distribution in your machine you can extract common code to.! S output in the generated document setup.py file which will install the is! Python have their own interfaces to Tk, allowing them also to use Tk building. Text inside the brackets, enables the caption pygmentize library through the Python download site listings. Libraries and packages that support various multiple tasks in the original document \begin Python. Or Py/TeX is you prefer, is to be from wiki wiki2beamer and built the. Involves three steps: 1 was written in Python which performs syntax-highlighting using Python in LaTeX La is! Apps like this with dash Enterprise \verb command a file becomes very handy editing plain Python files, Worksheets. Jupyter Notebooks files can be also generated automatically from Python scripts or from wiki2beamer. Character, except letters and *, can be also generated automatically from Python scripts or from wiki wiki2beamer best. Download '' to get the code at each a lexer and codec to work more effectively as a team solve... Executes code in LaTeX documents, or Py/TeX is you prefer, is be. Was written in for download for all versions org-mode to use the “ write18 ” of! Group, ETH Zurich, Switzerland code the listings package: LaTeX/Source code listings it 's incredibly simple, LaTeX. The code colouring and styling greatly improves readability click download '' to get code! Contrast, LuaTEX and PerlTEX execute all the code inside the \begin { verbatim a! Generating LaTeX snippets - £30 a couple of years ago, I decided try... Usages: generating full pdfs and generating LaTeX snippets involves three steps:.. 'Ll present an example is written in Python and Pseudocodeuseful also notebook extension, along with and... Provide some clues, including some LaTeX ( stdout ) is saved to an file. Example inside the brackets called it latextable, and insert the output into your document.Installing! Extract common code to write them use Python inside LaTeX have implemented such a separation python code in latex... You wish to include pseudocode or algorithms, you may find algorithms and Pseudocodeuseful also for.... Colours in LaTeX is verbatim, which generates an output in monospaced font use that to run the above commands! Abap ( R/2 4.3, R/2 5.0, R/3 4.6C command that automatically pulls code from file! Display expressions in a source file, therefore a command that automatically pulls code from the line 2 the. Below, run pip install dash, click download '' to get the from! Values from and input into a pretty LaTeX formula even used for numeral systems with.tex files containing or. Conversion to LaTeX is available as documentation LaT X, and insert the output from the line 12, previous... Needs for working with.tex files containing PythonTeX or sagetex code following code creates figure. From Luís Sequeira 's answer that there is a front end to TeX, written in the line 12 the. 2012 © BLOCK Research Group, ETH Zurich, Switzerland activated by setting text.usetex True... A team to solve the challenges of data science, machine learning and statistics the directions are based on Linux! Letters as mathematical symbols interpreted as ordinary LaTeX code to be an easy, but extensible between... Html version is latex_env_doc.html and a pdf resulting from conversion to LaTeX is verbatim, which more! A team to solve the challenges of data science, machine learning and statistics unexecuted... To import the code colouring and styling greatly improves readability article discusses the minted package which! Process and the output from the Python program is interpreted as ordinary LaTeX in... True in your rc settings experiments in data science also generated automatically from Python scripts or from wiki2beamer! ” facility of pdftex to execute arbitrary shell commands directly python code in latex Python in LaTeX is as.... we have to run the above 3 commands each time input into pretty... Will be included in the document execute arbitrary shell commands several Python libraries and that... That directly runs Python in LaTeX and html documents using Matplotlib is usually stored in a centered paragraph the command. The source code is saved to a shared file source file, therefore command! Has two quite different usages: generating full pdfs and generating LaTeX snippets with the “ ”... Following packages as well over the world, use certain greek letters as mathematical symbols may find and... Of pdftex to execute arbitrary shell commands is run through the Python program is as. Values from and input into a pretty LaTeX formula collaborators in real-time and everyone sees the very compiled. Use certain greek letters as mathematical symbols & LaTeX Projects for £10 - £30 LaTeX! 1000 Oman Currency To Naira, Book Page Quote Art, App State Women's Cross Country, Touring Caravan Sites In North Devon, Cast Of Scrooged 1984, Turkish Lira To Euro History, How Much Snow In Odessa, Weather London 14 Days Met Office, Published by: in Allgemein Facebook Share on Facebook Twitter Share on Twitter Google+ Share on Google+ Leave a Reply Save my name, email, and website in this browser for the next time I comment. (function($) { $(document).ready(function () {$("#commentform").validate(); }); })(jQuery); var mejsL10n = {"language":"en","strings":{"mejs.install-flash":"You are using a browser that does not have Flash player enabled or installed. Please turn on your Flash player plugin or download the latest version from https:\/\/get.adobe.com\/flashplayer\/","mejs.fullscreen-off":"Turn off Fullscreen","mejs.fullscreen-on":"Go Fullscreen","mejs.download-video":"Download Video","mejs.fullscreen":"Fullscreen","mejs.time-jump-forward":["Jump forward 1 second","Jump forward %1 seconds"],"mejs.loop":"Toggle Loop","mejs.play":"Play","mejs.pause":"Pause","mejs.close":"Close","mejs.time-slider":"Time Slider","mejs.time-help-text":"Use Left\/Right Arrow keys to advance one second, Up\/Down arrows to advance ten seconds.","mejs.time-skip-back":["Skip back 1 second","Skip back %1 seconds"],"mejs.captions-subtitles":"Captions\/Subtitles","mejs.captions-chapters":"Chapters","mejs.none":"None","mejs.mute-toggle":"Mute Toggle","mejs.volume-help-text":"Use Up\/Down Arrow keys to increase or decrease volume.","mejs.unmute":"Unmute","mejs.mute":"Mute","mejs.volume-slider":"Volume Slider","mejs.video-player":"Video Player","mejs.audio-player":"Audio Player","mejs.ad-skip":"Skip ad","mejs.ad-skip-info":["Skip in 1 second","Skip in %1 seconds"],"mejs.source-chooser":"Source Chooser","mejs.stop":"Stop","mejs.speed-rate":"Speed Rate","mejs.live-broadcast":"Live Broadcast","mejs.afrikaans":"Afrikaans","mejs.albanian":"Albanian","mejs.arabic":"Arabic","mejs.belarusian":"Belarusian","mejs.bulgarian":"Bulgarian","mejs.catalan":"Catalan","mejs.chinese":"Chinese","mejs.chinese-simplified":"Chinese (Simplified)","mejs.chinese-traditional":"Chinese (Traditional)","mejs.croatian":"Croatian","mejs.czech":"Czech","mejs.danish":"Danish","mejs.dutch":"Dutch","mejs.english":"English","mejs.estonian":"Estonian","mejs.filipino":"Filipino","mejs.finnish":"Finnish","mejs.french":"French","mejs.galician":"Galician","mejs.german":"German","mejs.greek":"Greek","mejs.haitian-creole":"Haitian Creole","mejs.hebrew":"Hebrew","mejs.hindi":"Hindi","mejs.hungarian":"Hungarian","mejs.icelandic":"Icelandic","mejs.indonesian":"Indonesian","mejs.irish":"Irish","mejs.italian":"Italian","mejs.japanese":"Japanese","mejs.korean":"Korean","mejs.latvian":"Latvian","mejs.lithuanian":"Lithuanian","mejs.macedonian":"Macedonian","mejs.malay":"Malay","mejs.maltese":"Maltese","mejs.norwegian":"Norwegian","mejs.persian":"Persian","mejs.polish":"Polish","mejs.portuguese":"Portuguese","mejs.romanian":"Romanian","mejs.russian":"Russian","mejs.serbian":"Serbian","mejs.slovak":"Slovak","mejs.slovenian":"Slovenian","mejs.spanish":"Spanish","mejs.swahili":"Swahili","mejs.swedish":"Swedish","mejs.tagalog":"Tagalog","mejs.thai":"Thai","mejs.turkish":"Turkish","mejs.ukrainian":"Ukrainian","mejs.vietnamese":"Vietnamese","mejs.welsh":"Welsh","mejs.yiddish":"Yiddish"}}; /* <![CDATA[ */ var _wpmejsSettings = {"pluginPath":"\/wp-includes\/js\/mediaelement\/","classPrefix":"mejs-","stretching":"responsive"}; /* ]]> */ /* <![CDATA[ */ var semplice = {"gallery_prev":"<svg version=\"1.1\" id=\"Ebene_1\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" x=\"0px\" y=\"0px\"\r\n\twidth=\"18px\" height=\"40px\" viewBox=\"0 0 18 40\" enable-background=\"new 0 0 18 40\" xml:space=\"preserve\">\r\n<g id=\"Ebene_2\">\r\n\t<g>\r\n\t\t<polygon points=\"16.3,40 0.3,20 16.3,0 17.7,1 2.5,20 17.7,39 \t\t\"\/>\r\n\t<\/g>\r\n<\/g>\r\n<\/svg>\r\n","gallery_next":"<svg version=\"1.1\" id=\"Ebene_1\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" x=\"0px\" y=\"0px\"\r\n\twidth=\"18px\" height=\"40px\" viewBox=\"0 0 18 40\" enable-background=\"new 0 0 18 40\" xml:space=\"preserve\">\r\n<g id=\"Ebene_2\">\r\n\t<g>\r\n\t\t<polygon points=\"0.3,39 15.5,20 0.3,1 1.7,0 17.7,20 1.7,40 \t\t\"\/>\r\n\t<\/g>\r\n<\/g>\r\n<\/svg>\r\n","lightbox_prev":"<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" preserveAspectRatio=\"xMidYMid\" width=\"30\" height=\"20\" viewBox=\"0 0 30 20\">\n <path d=\"M29.255,10.804 L2.624,10.804 L10.327,18.696 C10.619,18.995 10.619,19.481 10.327,19.780 C10.181,19.930 9.989,20.005 9.798,20.005 C9.607,20.005 9.415,19.930 9.269,19.780 L0.290,10.580 C0.220,10.509 0.165,10.424 0.127,10.330 C0.090,10.238 0.071,10.141 0.071,10.043 C0.071,10.041 0.070,10.039 0.070,10.037 C0.070,10.035 0.071,10.034 0.071,10.032 C0.071,9.934 0.090,9.836 0.127,9.745 C0.165,9.650 0.220,9.565 0.290,9.494 L9.269,0.294 C9.561,-0.005 10.035,-0.005 10.327,0.294 C10.619,0.594 10.619,1.079 10.327,1.378 L2.624,9.270 L29.255,9.270 C29.669,9.270 30.003,9.613 30.003,10.037 C30.003,10.461 29.669,10.804 29.255,10.804 Z\"\/>\n<\/svg>\n","lightbox_next":"<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" preserveAspectRatio=\"xMidYMid\" width=\"30\" height=\"20\" viewBox=\"0 0 30 20\">\n <path d=\"M29.873,9.745 C29.910,9.836 29.929,9.934 29.929,10.032 C29.929,10.034 29.930,10.035 29.930,10.037 C29.930,10.039 29.929,10.041 29.929,10.043 C29.929,10.141 29.910,10.238 29.873,10.330 C29.835,10.424 29.780,10.509 29.710,10.580 L20.731,19.780 C20.585,19.930 20.393,20.005 20.202,20.005 C20.011,20.005 19.819,19.930 19.673,19.780 C19.381,19.481 19.381,18.995 19.673,18.696 L27.376,10.804 L0.745,10.804 C0.331,10.804 -0.003,10.461 -0.003,10.037 C-0.003,9.613 0.331,9.270 0.745,9.270 L27.376,9.270 L19.673,1.378 C19.381,1.079 19.381,0.594 19.673,0.294 C19.965,-0.005 20.439,-0.005 20.731,0.294 L29.710,9.494 C29.780,9.565 29.835,9.650 29.873,9.745 Z\"\/>\n<\/svg>\n"}; /* ]]> */ (function($) { // back button fix (firefox) thx to Jesse from stack overfllow$(window).unload(function () { $(window).unbind('unload'); }); // back button fix (safari)$(window).bind('pageshow', function(event) { if (event.originalEvent.persisted) { window.location.reload() } }); $(document).ready(function () { /* ce images */$('.ce-image').each(function(){ var parentTag = $(this).parent().get(0).tagName; if(parentTag == 'A') {$(this).parent().remove(); } else { $(this).remove(); }}); /* remove single edit div */$('.single-edit').remove(); /* delete gallery brs */ $('.gallery br').each(function() {$(this).remove(); }); /* image lightbox */ var showOverlay = function() { $('<div class="lightbox-overlay"></div>').appendTo('body'); }; var hideOverlay = function() {$('.lightbox-overlay').remove(); }; /* arrows */ var arrowsOn = function(instance, selector) { var $arrows =$('<div class="lightbox-arrows"><a type="button" class="imagelightbox-arrow imagelightbox-arrow-left">' + semplice.lightbox_prev + '</a><a type="button" class="imagelightbox-arrow imagelightbox-arrow-right">' + semplice.lightbox_next + '</a></div>'); $arrows.appendTo('body'); // fade in$('.lightbox-arrows').delay(200).fadeIn('slow'); $('.imagelightbox-arrow').on('click touchend', function(e) { e.preventDefault(); var$this = $(this),$target = $( selector + '[href="' +$('#imagelightbox').attr('src') + '"]'), index = $target.index(selector); if($this.hasClass('imagelightbox-arrow-left')) { index = index - 1; if(!$(selector).eq(index).length) index =$(selector).length; } else { index = index + 1; if( !$(selector).eq(index).length) index = 0; } instance.switchImageLightbox(index); return false; }); }; var arrowsOff = function() {$('.lightbox-arrows').fadeOut('fast', function() { $('.lightbox-arrows').remove(); }); }; /* blog gallery */$('.gallery-icon a').each(function () { /* check if attachment or media file type */ var isAttachment = $(this).attr('href').slice(-1); if(isAttachment !== '/') {$(this).attr('data-rel', 'lightbox'); } }); var selectorG = 'a[data-rel^=lightbox]'; var instanceG = $(selectorG).imageLightbox( { selector: 'id="imagelightbox"', allowedTypes: 'png|jpg|jpeg|gif|svg', animationSpeed: 250, preloadNext: true, enableKeyboard: true, quitOnEnd: false, quitOnImgClick: false, quitOnDocClick: true, onStart: function() { arrowsOn(instanceG,selectorG); showOverlay(); }, onEnd: function() { arrowsOff(); hideOverlay(); }, onLoadStart: false, onLoadEnd: false }); // content editor self hosted video and blog video$(".live-video video, .live-audio audio, .wysiwyg video, .wysiwyg audio").mediaelementplayer({ // options pauseOtherPlayers: false, stretching: 'responsive', success: function (mediaElement, domObject) { meSuccessCallback(mediaElement, domObject); } }); // cover video $(".cover-video video").mediaelementplayer({ // options pauseOtherPlayers: false, success: function (mediaElement, domObject) { meSuccessCallback(mediaElement, domObject); } }); // mediaelement success callback function meSuccessCallback(mediaElement, domObject) { // get media element var$thisMediaElement = (mediaElement.id) ? $("#"+mediaElement.id) :$(mediaElement); if($thisMediaElement.attr('data-masonry-id')) { // layout masonry to avoid overlapping$('#masonry-' + $thisMediaElement.attr('data-masonry-id')).masonry('layout'); } // empty poster image to avoid double images$thisMediaElement.attr('poster', ''); // resize multicolumn on play if needed mediaElement.addEventListener('canplay', function(e) { $('#masonry-' +$thisMediaElement.attr('data-masonry-id')).masonry('layout'); }, false); // show poster image after video finished mediaElement.addEventListener("ended", function(e){ \$thisMediaElement.parents(".mejs-inner").find(".mejs-poster").show(); }); } }); })(jQuery); | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5696463584899902, "perplexity": 9730.368003462734}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178375529.62/warc/CC-MAIN-20210306223236-20210307013236-00226.warc.gz"} |
https://www.arxiv-vanity.com/papers/1512.08443/ | # The Polyakov loop at next-to-next-to leading order
Matthias Berwein Physik-Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany Nora Brambilla Physik-Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany Institute for Advanced Study, Technische Universität München, Lichtenbergstraße 2a, 85748 Garching, Germany Péter Petreczky Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA Antonio Vairo Physik-Department, Technische Universität München, James-Franck-Straße 1, 85748 Garching, Germany
March 4, 2021
###### Abstract
We calculate the next-to-next-to-leading correction to the expectation value of the Polyakov loop or equivalently to the free energy of a static charge. This correction is of order . We show that up to this order the free energy of the static charge is proportional to the quadratic Casimir operator of the corresponding representation. We also compare our perturbative result with the most recent lattice results in SU(3) gauge theory.
###### pacs:
12.38.-t, 12.38.Bx, 12.38.Mh
preprint: TUM-EFT 67/15
## I Introduction
The Polyakov loop is an order parameter for deconfinement in pure SU(N) gauge theories at nonzero temperature . It is defined as
L=1dRTr⟨Pexp[ig∫1/T0dτA0(τ,x)]⟩, (1)
where denotes path ordering of the exponential of the zero component of the gauge field integrated along the compactified imaginary time direction, and is the coupling constant. Here we have defined the Polyakov loop in a general representation of SU(N), so the gauge fields are understood as matrices in this representation , and is the dimension of this representation. The thermal expectation value of a single Polyakov loop is invariant under translations, so we can choose it to be at the origin in the following.
The nonzero expectation value of the Polyakov loop above some temperature indicates the onset of color screening and thus deconfinement Polyakov (1978). Early lattice studies of the Polyakov loop and its correlators were instrumental in establishing the existence of a deconfinement transition in non-Abelian gauge theories from first principle calculations Kuti et al. (1981); McLerran and Svetitsky (1981). The physical interpretation of the logarithm of the Polyakov loop expectation value is the free energy of a static quark (see, e.g., discussions in Ref. McLerran and Svetitsky (1981)). The free energy of a static quark in a gluonic plasma is finite due to color screening, but becomes infinite below the phase transition temperature .
While in the presence of flavors of light quarks the Polyakov loop is no longer an order parameter for deconfinement Fukushima (2003), its value at sufficiently high temperatures is still a measure of the screening properties of the deconfined medium. It is easy to see that at leading nontrivial order the Polyakov loop expectation value is , or equivalently , where is the quadratic Casimir of the representation . The Debye mass is given by
m2D=CA+TFnf3g2T2, (2)
where is the quadratic Casimir of the adjoint representation and is the normalization constant of the fundamental representation, for which usually the value is taken. The next-to-leading-order (NLO) contribution to the Polyakov loop is of . The first calculation of the NLO contribution was performed long ago Gava and Jengo (1981). However, several years later, it was shown that this calculation was not correct and the correct NLO contribution was calculated independently by two groups Burnier et al. (2010); Brambilla et al. (2010a).
The Polyakov loop has been studied in lattice QCD both in SU(N) gauge theories Kaczmarek et al. (2002, 2004); Digal et al. (2003); Mykkanen et al. (2012) and in the physically relevant case of flavor QCD Aoki et al. (2006); Cheng et al. (2008); Aoki et al. (2009); Bazavov et al. (2009); Borsányi et al. (2010); Bazavov et al. (2012a); Bazavov and Petreczky (2013); Borsányi et al. (2015). For the understanding of the screening properties of the deconfined medium it is important to connect lattice calculations with perturbative calculations at high temperatures and to see to what extent these calculations agree. In this perspective it is important to compute next-to-next-to-leading order (NNLO) corrections, which will considerably reduce the uncertainties of the NLO result by fixing the scale dependence of the coupling constant at leading order. The computation of the Polyakov loop at NNLO accuracy is the purpose of the present work.
One feature of the lattice results on the Polyakov loop is Casimir scaling Mykkanen et al. (2012). One outcome of our analysis is that Casimir scaling holds up to . This is important for understanding the lattice results for the Polyakov loops in higher representations Gupta et al. (2008); Mykkanen et al. (2012); Petreczky and Schadler (2015).
The rest of the paper is organized as follows. In the next section we outline our strategy for the perturbative calculation to and discuss the power counting. The calculation of the necessary loop integrals is presented in section III, which also contains the main result of the paper. In section IV, we comment on the higher order perturbative terms discussing Casimir scaling and outlining the calculation. In section V, we compare the perturbative result with available lattice results. Finally, section VI contains our conclusions. Several technical details of the calculations are presented in appendices.
## Ii Outline of the perturbative calculation
In this section, we will outline the perturbative calculation of the Polyakov loop. We will perform calculations directly in QCD as well as using the effective field theory approach. The direct calculation of the NNLO correction to the Polyakov loop is rather involved and its details will be discussed in the next section. On the other hand, as we will see, the calculation that relies on the effective field theory approach is rather simple, because we can draw on previous results.
### ii.1 The structure of the perturbative series
The following way of defining the path ordered exponential is particularly suited for perturbative expansions:
L (3)
The Feynman diagrams for the Polyakov loop can then be drawn as a straight line from to in the imaginary time direction to which gluons are attached. The line represents the contour integrations over the gauge fields. In the gauges we are going to use for this calculation, where the gluon propagator is diagonal in color space, it is possible to split each diagram into a color coefficient and a loop integral. The color coefficient contains the trace over the color matrices from the gauge fields and any structure constants coming from interaction vertices as well as symmetry factors, while the loop integral contains the integrations over Euclidean time, spatial momenta, etc., as well as the propagators and the Lorentz structures.111Since three- and four-gluon vertices contain a sum over several terms, it may be necessary for some diagrams to split each term separately into color coefficient and loop integral. This is not required for any diagram appearing in this paper, only in the case of tadpoles there appear two terms from the vertex, but they give the same contribution, so we just include a factor in the color color coefficient.
It has been shown in Gatheral (1983); Frenkel and Taylor (1984) that the perturbative series for any closed Wilson line can be rearranged such that it takes the form of an exponential of a series over the same diagrams but with altered color coefficients, several of which are zero. This result has been generalized in Gardi et al. (2010); *Gardi:2013ita for the exponentiation of any Wilson line operator (for an application in the context of heavy quarks in thermal QCD, see Berwein et al. (2013); *Berwein:2013xza). In the case of the Polyakov loop we have
L (4)
where we have written the color coefficients explicitly. and are the quadratic Casimirs of the representation of the Polyakov loop and the adjoint representation respectively. The gluon propagators are understood as resummed. The dots represent diagrams with three or more gluons, which are at least and therefore beyond our accuracy. There is also a diagram with three propagators connected by a three-gluon vertex, which would be at leading order, but since a three-gluon vertex with only temporal indices vanishes, this diagram gives no contribution in all gauges where the propagator is block diagonal in the temporal and spatial components, so it has been neglected in the expression above. We note that the free energy of the static charge corresponding to the above expression is proportional to . This property is known as Casimir scaling.
First, we perform the integral over the Euclidean time in the expression for and to get
D1 =CR(ig)2∫1/T0dτ1∫τ10dτ2∑K∫eik0(τ1−τ2)D00(K)=−CRg22T∫kD00(0,k), (5) D2 =−12CRCA(ig)4∫1/T0dτ1∫τ10dτ2∫τ20dτ3∫τ30dτ4∑K,Q∫eik0(τ1−τ3)eiq0(τ2−τ4)D00(K)D00(Q) =−CRCAg44T∫k,q⎡⎣112TD00(0,k)D00(0,q)−∑k0′1k20D00(K)(2D00(0,q)−D00(k0,q))⎤⎦, (6)
where and include both the spatial momenta and and the Matsubara frequencies and , which are given by with . We use boldface letters to denote vectors in dimensions and regular font letters for the absolute value, so . The sum-integral symbols are a shorthand for the Matsubara sums and the -dimensional integrals, which are defined in the following way:
∑K∫f(k0,k)=∑k0∫kf(k0,k)=T∑n∈Z∫ddk(2π)df(2πTn,k). (7)
The sum with a prime denotes a Matsubara sum without the zero mode, i.e., . Up to this point the discussion is independent of the choice of gauge for the perturbative calculations. In this paper we will use Feynman gauge, static gauge, and Coulomb gauge. In Appendix A, we discuss the gluon propagators and self-energies in these gauges.
The integration momenta and can either be of the order of the temperature scale or of the scale of the Debye mass . In principle, they may also scale with the nonperturbative magnetic mass . The magnetic mass enters the temporal propagators not directly but only through self-energies. Hence, as we will show at the end of this section, momentum regions scaling with contribute only to . We use dimensional regularization to treat both infrared and ultraviolet divergences. In this regularization scheme the different momentum scales can be separated by expanding the integrand according to the hierarchy .
We start considering . Separating out the contributions from the scales , , and we write
D1 =−CRg22T∫k1k2+Π(0,k) =−CRg22T⎧⎨⎩∫k∼T−Π(1)T(0,k)k4+∫k∼mD⎡⎣1k2+m2D−Π(1)mD(0,k)(k2+m2D)2+Π(1)mD(0,k)2(k2+m2D)3 −1(k2+m2D)2⎛⎝dΠ(1)Tdk2(0,0)k2+Π(2)T(0,0)+Π(2)mD(0,k)+Π(1)mM(0,k)⎞⎠⎤⎦⎫⎬⎭+O(g6). (8)
Here , , and denote the contributions to the self-energy of the field at -loop order coming from loop momenta of order , , and . There can also be self-energies where the loop momenta are not all of the same scale, but these do not contribute until . The self-energies entering the above equation depend on the choice of gauge. The terms proportional to and , together with tree-level , give rise to the known term in the expression of the Polyakov loop Burnier et al. (2010); Brambilla et al. (2010a). The 2-loop scale contribution to the self-energy as well as the term give rise to terms of , some of which have been identified in Ref. Brambilla et al. (2010a) and are related to the running of the coupling constant. The terms proportional to and are new and also contribute at to the Polyakov loop. In section III, we will discuss the calculation of these terms in detail. Finally, the term proportional to does not contribute to the Polyakov loop at and . This will also be shown in section III.
Concerning , it is easy to see that the leading order contribution of the first term in Eq. (6) in any gauge comes only from the scale and is of , which is beyond the accuracy of this calculation. It was already identified in Ref. Brambilla et al. (2010a). The second and third terms in Eq. (6) do not contribute in static gauge because vanishes for nonzero . In Coulomb gauge the second term starts to contribute at and the third at , since the leading order propagators with nonzero Matsubara frequencies are scaleless and need at least one loop insertion to not vanish. In Feynman gauge the second term in Eq. (6) contributes already at for and , while the third starts to contribute at when both momenta are of the scale . There is no contribution from the third term, since the scale can only enter Feynman gauge propagators with nonzero frequencies through loops, which would at least be of .
In summary we see that the contribution to the Polyakov loop receives two different contributions. The first comes from terms with mixed scales like the two-loop self-energy at a scale with loop momenta of order or two-gluon exchange. The second comes from the two-loop self energy with loop momenta of order . In the effective field theory approach that will be discussed in the next subsection these two contributions correspond to two different steps of the calculation: the determination of the matching coefficients and the calculation of the correlators in the effective theory, respectively.
### ii.2 The Polyakov loop in an effective field theory approach
The separation between the scales and that was used in the calculation of the previous section can be incorporated in an effective theory, the so-called electrostatic QCD (EQCD) Braaten and Nieto (1996); Kajantie et al. (1997a) (for earlier and related works on this subject see Refs. Ginsparg (1980); Appelquist and Pisarski (1981); D’Hoker (1982); Nadkarni (1983); Landsman (1989); Reisz (1992); LaCock et al. (1992); Karkkainen et al. (1993, 1994); Patkos et al. (1998); Karsch et al. (1998); Kajantie et al. (1997b); Laine and Philipsen (1999); Hart and Philipsen (2000); Hart et al. (2000); Cucchieri et al. (2001a, b)). In EQCD the scale is integrated out, which includes all fields with nonzero Matsubara frequencies. This means that quark fields are completely absent and the gluons do not depend on the imaginary time coordinate. So EQCD is a three-dimensional field theory where no longer plays the role of a gauge field, but becomes an adjoint scalar field. As a consequence, a mass term for does not break gauge invariance in EQCD.
The contribution from the nonperturbative magnetic scale can also be calculated in this effective field theory approach. Namely if the scale can also be integrated out leading to an effective field theory called magnetostatic QCD (MQCD), which is the three-dimensional Yang-Mills theory Braaten and Nieto (1996). Using this sequence of effective theories the weak coupling expansion of the QCD pressure has been calculated Braaten and Nieto (1996) finding a solution to the well known infrared problem Linde (1980).
The imaginary time integration in the EQCD action just gives a factor , since the fields no longer depend on the imaginary time coordinate. This factor can be absorbed in a rescaling of the fields and gauge coupling by a factor (denoted by a tilde over the fields). The Lagrangian is then given by
LEQCD= 14(˜Faij)2+12(˜Dabi˜Ab0)2+m2E2(˜Aa0)2 +λE(Tr[˜A20])2+¯λE(Tr[˜A40]−12(Tr[˜A20])2)+…, (9)
where , , and the dots stand for higher dimensional operators. The fields and in the above Lagrangian have canonical dimension . The gauge coupling of EQCD is dimensionful. At leading order we have , , , and (see, e.g., Kajantie et al. (1997a)). The second quartic interaction is a vanishing operator for or , so any result can only depend on for . The couplings , , and have been calculated to next-to-leading order (NLO) Kajantie et al. (1997a). The three-dimensional gauge coupling is known to next-to-next-to-leading order Laine and Schröder (2005). The NLO correction to has been calculated in Ref. Braaten and Nieto (1996)
m2E= m2D[1+αs4π(53CA+43TFnf(1−4ln2)+2β0(γE+lnμ4πT))]−2CFTFnfα2sT2, (10)
where is the quadratic Casimir of the fundamental representation. Here and in the rest of this section we express all matching parameters in terms of the renormalized coupling. Thus the pole that appears with the first coefficient of the beta function has already been canceled. The relation between the bare coupling and the renormalized coupling at one-loop in the -scheme is
g2=g2R[1−αsβ04π(1ϵ−γE+ln4π)+…], (11)
where is related to the number of spatial dimensions through .
In EQCD we can write the Polyakov loop in the following way Burnier et al. (2010)
(12)
The matching coefficients are equal to at leading order, at higher orders they can be written as an expansion in , i.e., only in even powers of . In the power counting of EQCD, every power of counts as , so the term proportional to starts to contribute at . In EQCD only the scales and are still dynamical, which means that no loop momenta of order appear in the evaluation of the Feynman diagrams. The contributions of such loops are contained in higher order corrections to the matching coefficients and the EQCD parameters.
For the determination of and from QCD it is convenient to use the static gauge. In this gauge we can write
(13)
Now we can separate each contribution into a static and a nonstatic piece, i.e., we can write
⟨A20⟩=⟨A20⟩s+⟨A20⟩ns. (14)
The notation means that there appear only loop momenta of order in the evaluation of the corresponding Feynman diagrams, which corresponds to a strict perturbative expansion in without any resummation of self-energies. The notation then means that some or all loop momenta are of order or . The corresponding Matsubara frequencies have to be zero, hence the name “static”. We can write down a similar decomposition for .
The sum over all nonstatic pieces exactly gives . Since in static gauge the scale can enter the temporal propagators only through loops, the nonstatic part of the contribution will contribute first at . The leading order result for the piece can be found in Ref. Brambilla et al. (2010a) and gives
Z0=1+CRα2s2[CA(12ϵ+1−γE+lnπμ2T2)−2TFnfln2]+O(α3s). (15)
The pole in is not related to charge renormalization, but corresponds to an infrared divergence in the nonstatic part that cancels against an ultraviolet divergence in the static piece, or equivalently in the EQCD calculation.
The sum over the static pieces then contains all contributions from the scales and and thus corresponds to the EQCD representation of the Polyakov loop without the unit operator. Up to it is sufficient to consider only the quadratic terms, i.e., . The two gauge fields in themselves can carry either momenta or , however, in the latter case they only start to contribute to the static piece at three-loop order. The first loop from the two gauge fields in the correlator is scaleless, so another loop is needed to introduce the scale and a third one to include the scale in order to be counted towards the static piece. This corresponds to diagrams like and in Fig. 1 when only the tadpole or the subloop momentum is of order and the two other momenta are of order . The two scale integrations give a contribution of to and only one propagator with a momentum of order remains, which corresponds to the leading order of .
In the former case we can relate the QCD field to in EQCD, where the wave function normalization constant can be obtained from the small momentum expansion of the propagator:
DQCD00(k≪T)=Z2DEQCD00(k)+…. (16)
The dots stand for higher powers in the small expansion, which correspond to higher order two-point interactions in EQCD. From this expression it follows that
Z2=(1+dΠTdk2(k2=0))−1, (17)
and with the result from Brambilla et al. (2010a) we have up to corrections of
Z2=Z2=1+αs4π[113CA+43TFnf(1−4ln2)+2β0(γE+lnμ4πT)]. (18)
Now that we have determined the matching coefficients to the desired order, we can write the weak coupling expansion for as
1dRTr⟨˜A20⟩=−CRmE4π(1+a1g2EmE+a2g4Em2E+a3g6Em3E+a4λEmE+…), (19)
using simple dimensional analysis. In the above expression we explicitly wrote down all the terms contributing up to and ignored the magnetic mass scale . We will return to the contribution from the scale later.
In Eq. (19) the terms proportional to come from the -loop self-energy of the field. The coefficient is known Burnier et al. (2010); Brambilla et al. (2010a). We are primarily interested in the NNLO, i.e., contribution to . It is evident from Eqs. (10), (18), and (19) that the mixed scale contributions from the previous section come from the corrections to and , while the pure scale term comes from the two-loop self-energy contribution contained in the coefficient . One can perform a similar analysis for and see that it contributes at orders , , etc. It is also easy to generalize the analysis for , , and see that these terms do not contribute at .
The only remaining task is now to calculate the coefficient . This can be done using the EQCD calculation of the pressure Braaten and Nieto (1996)
p=−T(fE+fM−1VlnZMQCD). (20)
Here we use the same notation as in Ref. Braaten and Nieto (1996), i.e., denotes the contribution from the scale , denotes the contribution from the scale , and is the partition function of MQCD, which is completely nonperturbative. Ignoring the contribution from MQCD it is easy to see that since
fM=−1Vln∫D˜Aa0D˜Aaiexp[−∫d3xLEQCD], (21)
it follows that
1dRTr⟨˜A20⟩=CRN2−1⟨˜Aa0˜Aa0⟩=2CRN2−1∂fM∂m2E. (22)
Using the expression for from Braaten and Nieto (1996) we get
1dRTr⟨˜A20⟩= −CRmE4π+CRCAg2E(4π)2[12ϵ+12−γE+lnπμ2m2E] +2CRC2A(4π)3g4EmE(8948−1112ln2+π212)+O(g4). (23)
The first term corresponds to the well-known leading order result. The second term is identical to the static contribution to (c.f. Eq. of Ref. Brambilla et al. (2010a)). The pole in this term is exactly the ultraviolet divergence that cancels against the infrared pole in the nonstatic contribution to Brambilla et al. (2010a). The scale dependence cancels in the same way. The last term gives the coefficient we are interested in.
We still need to calculate the contribution arising from the corrections to and times the leading order result for . Using Eqs. (10) and (18) we find that this contribution is
(24)
With this result and Eq. (23) we find the contribution to the Polyakov loop
L∣∣g5= 3CRα2smD16πT[3CA+43TFnf(1−4ln2)+2β0(γE+lnμ4πT)] −CRC2Aα3sTmD(8948−1112ln2+π212)−CRCFnfTFα3sT2mD. (25)
The above equation is the main result of this paper. In the next section we will obtain this result via direct calculations in QCD.
The contribution from the scale to , which we have neglected so far, can be calculated using MQCD, the effective theory obtained from EQCD by integrating out the electric scale . The only scale in MQCD is the dimensionful coupling constant , which is given at leading order as . Since in this theory we have only the three-dimensional gauge fields, we write
L=ZM0+ZM12m3D⟨˜Faij˜Faij⟩MQCD+…. (26)
The matching constant contains the contributions to from the scales and , so up to . The matching constant has been calculated in Ref. Braaten and Nieto (1995) for the fundamental representation. We have repeated that calculation, but allowed for general representations; the result is
ZM1=CRCAα2sπ12(N2−1)+O(g5), (27)
and for one obtains the expression from Braaten and Nieto (1995). Since , we see that the contribution from the magnetic scale first appears at . Through the explicit calculations presented in section III and appendix C we will see that the magnetic contributions at and indeed vanish.
The contribution to the Polyakov loop can be obtained using lattice calculations in MQCD. However, for interesting temperature ranges the separation of the scales and is not obvious. Therefore, it is more practical to calculate using lattice calculations in EQCD. Such lattice calculations have been performed with the aim to estimate the QCD pressure using the EQCD approach in Ref. Hietanen et al. (2009). We will use this lattice EQCD result when comparing the weak coupling expansion of the Polyakov loop with lattice results in QCD in section V.
## Iii Calculation of the O(g5) correction to the Polyakov loop
In this section we will present the calculations of the contribution to the Polyakov loop directly in QCD. From the discussion in the previous section it is clear that the diagrams that contribute at always have at least one momentum integral of order , while the self-energy contributions may arise from the scales , , or . In what follows we will refer to them as contributions from the scale , , or , even though all the loop diagrams also involve the scale . We will perform the calculations in Coulomb gauge and in Feynman gauge. The contribution from the diagram is only relevant in Feynman gauge. It involves one integral over the scale and another sum-integral over the scale , so we will refer to it as a part of the contribution from the scale .
### iii.1 Contribution from the scale T
All self-energies relevant for the contribution from the scale in Feynman gauge are known and can be found in Ref. Braaten and Nieto (1996) (they use a slightly different convention for the -scheme, which can be converted into our convention by replacing the renormalization scale in their expressions by ):
Π(1)T(0,0) ≡m2D(ϵ)=g2T23[(CA+TFnF)+CA(−γE+2ζ′(−1)ζ(−1)+lnμ24πT2)ϵ +TFnf(1−γE+2ζ′(−1)ζ(−1)+lnμ216πT2)ϵ], (28) dΠ(1)Tdk2(0,0) (29) Π(2)T(0,0) =g4T2(4π)2[23C2A(1ϵ+1+2ζ′(−1)ζ(−1)+2lnμ24πT2) +23CATFnf(1ϵ+2+2ζ′(−1)ζ(−1)+2lnμ28πT2)−2CFTFnF] =g2(4π)2[2CAm2D(ϵ)(1ϵ+1+γE+lnμ24πT2)−2g2T2CFTFnf]. (30)
In the last line we have re-expressed some terms through , i.e., the leading order Debye mass with corrections. This will be crucial for the cancellation of the -poles. The terms of are necessary at this point.
With these we can calculate the first scale contribution from diagram at in Feynman gauge (FG):
D1∣∣FGg5,T =CRg22T∫k∼mD1(k2+m2D)2⎛⎝dΠ(1)Tdk2(0,0)k2+Π(2)T(0,0)⎞⎠ =3CRα2smD(ϵ)16πT[73CA(1ϵ+2321+2lnμ22TmD)−43TFnf(1ϵ+13+2ln2μ2TmD)] −CRCFTFnfα3sT2mD. (31)
The scale contribution from is given by
D2∣∣FGg5,T =CRCAg42T∑q0′∫q∼T∫k∼mD1q20(q20+q2)(k2+m2D) =CRCAα2smD(ϵ)4πT(1ϵ+4+2lnμ22TmD), (32)
and together they give
(D1+D2)∣∣FGg5,T=−CRCFTFnfα3sT2mD +3CRα2smD(ϵ)16πT[113CA(1ϵ+7133+2lnμ22TmD)−43TFnf(1ϵ+13+2ln2μ2TmD)]. (33)
We see now that the coefficient of the -terms is proportional to the first coefficient of the beta function . This suggests that they are removed through charge renormalization, which is indeed the case. The first counter term comes from charge renormalization of the term. We need to be careful with the limit, so we will keep the dimension general until the last step:
D1∣∣g3 =−CRg22T∫k∼mD1k2+m2D=−CRg2Γ(1−d2)md−2Dμ2ϵ2(4π)d2T g0→gR⟶−CRg2Γ(1−d2)md−2D(ϵ)μ2ϵ2(4π)d2T[1−d2αsβ04π(1ϵ−γE+ln4π)+O(α2s)]. (34)
The factor comes from the power of : . Including the counter term for the charge renormalization we get the full contribution from the scale :
(D1+D2)∣∣g5,T= 3CRα2smD16πT[3CA+43TFnf(1−4ln2)+2β0(γE+lnμ4πT)] −CRCFTFnfα3sT2mD. (35)
We no longer indicate Feynman gauge in this final result for the scale contribution, because it is gauge invariant.
The corresponding calculation goes the same way for both Coulomb (CG) and static gauge (SG). is scaleless at , so only contributes. It has been shown in Braaten and Nieto (1996) that the electric mass parameter of EQCD is given up to by
m2E=Π(1)T(0,0)+Π(2)T(0,0)−Π(1)T(0,0)dΠ(1)Tdk2(0,0). (36)
Since is a gauge invariant parameter, we can eliminate in Coulomb or static gauge from this equation and express it through the Feynman gauge results and , which is the same for Coulomb and static gauge and can be found, e.g., in Brambilla et al. (2010a):
dΠ(1)Tdk2(0,0)=−g2(4π)2[113CA+43TFnf(1−4ln2)+β0(1ϵ+γE+lnμ24πT2)]. (37)
With this we have
Π(2)T∣∣CG/SG =(Π(2)T−m2D(ϵ)dΠ(1)Tdk2)∣∣∣FG+m2D(ϵ)dΠ(1)Tdk2∣∣∣CG/SG =−2g2(4π)2(CAm2D+g2T2CFTFnf). (38)
The contributions from the scale are now
D1∣∣CG/SGg5,T =CRg22T∫k∼mD1k2+m2D(dΠ(1)dk2(0,0)+Π(2)(0,0)) =3CRα2smD(ϵ)16πT[719CA−49TFnf(1+12ln2)+β0(1ϵ+2lnμ22TmD)] −CRCFTFnfα3sT2mD. (39)
This is the same result that we got in Feynman gauge from , so including the counter term we obtain the same scale contribution in Coulomb and static gauge:
(D1+D2)∣∣g5,T= 3CRα2smD16πT[3CA+43TFnf(1−4ln2)+2β0(γE+lnμ4πT)] −CRCFTFnfα3sT2mD. (40) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9601187109947205, "perplexity": 514.5488148946674}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780057564.48/warc/CC-MAIN-20210924171348-20210924201348-00246.warc.gz"} |
http://manpages.ubuntu.com/manpages/oneiric/man1/grodvi.1.html | Provided by: groff_1.21-6_i386
#### NAME
grodvi - convert groff output to TeX dvi format
#### SYNOPSIS
grodvi [ -dlv ] [ -Fdir ] [ -ppapersize ] [ -wn ] [ files... ]
It is possible to have whitespace between a command line option and its
parameter.
#### DESCRIPTION
grodvi is a driver for groff that produces TeX dvi format. Normally it
should be run by groff -Tdvi. This will run troff -Tdvi; it will also
input the macros in /usr/share/groff/1.21/tmac/dvi.tmac.
The dvi file generated by grodvi can be printed by any correctly-
written dvi driver. The troff drawing primitives are implemented using
the tpic version 2 specials. If the driver does not support these, the
\D commands will not produce any output.
There is an additional drawing command available:
\D'R dh dv'
Draw a rule (solid black rectangle), with one corner at the
current position, and the diagonally opposite corner at the
current position +(dh,dv). Afterwards the current position will
be at the opposite corner. This produces a rule in the dvi file
and so can be printed even with a driver that does not support
the tpic specials unlike the other \D commands.
The groff command \X'anything' is translated into the same command in
the dvi file as would be produced by \special{anything} in TeX;
anything may not contain a newline.
For inclusion of EPS image files, -Tdvi loads pspic.tmac automatically,
providing the PSPIC macro. Please check groff_tmac(5) for a detailed
description.
Font files for grodvi can be created from tfm files using tfmtodit(1).
The font description file should contain the following additional
commands:
internalname name
The name of the tfm file (without the .tfm extension) is
name.
checksum n The checksum in the tfm file is n.
designsize n The designsize in the tfm file is n.
These are automatically generated by tfmtodit.
The default color for \m and \M is black. Currently, the drawing color
for \D commands is always black, and fill color values are translated
to gray.
In troff the \N escape sequence can be used to access characters by
their position in the corresponding tfm file; all characters in the tfm
file can be accessed this way.
By design, the DVI format doesn't care about physical dimensions of the
output medium. Instead, grodvi emits the equivalent to TeX's
\special{papersize=width,length} on the first page; dvips (and possibly
other DVI drivers) then sets the page size accordingly. If either the
page width or length is not positive, no papersize special is output.
#### OPTIONS
-d Do not use tpic specials to implement drawing commands.
Horizontal and vertical lines will be implemented by rules.
Other drawing commands will be ignored.
-Fdir Prepend directory dir/devname to the search path for font and
device description files; name is the name of the device,
usually dvi.
-l Specify landscape orientation.
-ppapersize
Specify paper dimensions. This overrides the papersize,
paperlength, and paperwidth commands in the DESC file; it
accepts the same arguments as the papersize command (see
groff_font(5) for details).
-v Print the version number.
-wn Set the default line thickness to n thousandths of an em. If
this option isn't specified, the line thickness defaults to
0.04 em.
#### USAGE
There are styles called R, I, B, and BI mounted at font positions 1
to 4. The fonts are grouped into families T and H having members in
each of these styles:
TR CM Roman (cmr10)
TI CM Text Italic (cmti10)
TB CM Bold Extended Roman (cmbx10)
TBI CM Bold Extended Text Italic (cmbxti10)
HR CM Sans Serif (cmss10)
HI CM Slanted Sans Serif (cmssi10)
HB CM Sans Serif Bold Extended (cmssbx10)
HBI CM Slanted Sans Serif Bold Extended (cmssbxo10)
There are also the following fonts which are not members of a family:
CW CM Typewriter Text (cmtt10)
CWI CM Italic Typewriter Text (cmitt10)
Special fonts are MI (cmmi10), S (cmsy10), EX (cmex10), SC (cmtex10,
only for CW), and, perhaps surprisingly, TR, TI, and CW, due to the
different font encodings of text fonts. For italic fonts, CWI is used
Finally, the symbol fonts of the American Mathematical Society are
available as special fonts SA (msam10) and SB (msbm10). These two
fonts are not mounted by default.
Using the option -mec (which loads the file ec.tmac) provides the EC
and TC fonts. The design of the EC family is very similar to that of
the CM fonts; additionally, they give a much better coverage of groff
symbols. Note that ec.tmac must be called before any language-specific
files; it doesn't take care of hcode values.
#### ENVIRONMENT
GROFF_FONT_PATH
A list of directories in which to search for the devname
directory in addition to the default ones. See troff(1) and
groff_font(5) for more details.
#### FILES
/usr/share/groff/1.21/font/devdvi/DESC
Device description file.
/usr/share/groff/1.21/font/devdvi/F
Font description file for font F.
/usr/share/groff/1.21/tmac/dvi.tmac
Macros for use with grodvi.
/usr/share/groff/1.21/tmac/ec.tmac
Macros to switch to EC fonts.
#### BUGS
Dvi files produced by grodvi use a different resolution (57816 units
per inch) to those produced by TeX. Incorrectly written drivers which
assume the resolution used by TeX, rather than using the resolution
specified in the dvi file will not work with grodvi.
When using the -d option with boxed tables, vertical and horizontal
lines can sometimes protrude by one pixel. This is a consequence of
the way TeX requires that the heights and widths of rules be rounded.
#### SEEALSO
tfmtodit(1), groff(1), troff(1), groff_out(5), groff_font(5),
groff_char(7), groff_tmac(5) | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9488376379013062, "perplexity": 16132.738721395861}, "config": {"markdown_headings": true, "markdown_code": false, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042990123.20/warc/CC-MAIN-20150728002310-00245-ip-10-236-191-2.ec2.internal.warc.gz"} |
https://en.wikipedia.org/wiki/Power_series_solution_of_differential_equations | # Power series solution of differential equations
In mathematics, the power series method is used to seek a power series solution to certain differential equations. In general, such a solution assumes a power series with unknown coefficients, then substitutes that solution into the differential equation to find a recurrence relation for the coefficients.
## Method
Consider the second-order linear differential equation
$a_2(z)f''(z)+a_1(z)f'(z)+a_0(z)f(z)=0.\;\!$
Suppose a2 is nonzero for all z. Then we can divide throughout to obtain
$f''+{a_1(z)\over a_2(z)}f'+{a_0(z)\over a_2(z)}f=0.$
Suppose further that a1/a2 and a0/a2 are analytic functions.
The power series method calls for the construction of a power series solution
$f=\sum_{k=0}^\infty A_kz^k.$
If a2 is zero for some z, then the Frobenius method, a variation on this method, is suited to deal with so called singular points. The method works analogously for higher order equations as well as for systems.
## Example usage
Let us look at the Hermite differential equation,
$f''-2zf'+\lambda f=0;\;\lambda=1$
We can try to construct a series solution
$f=\sum_{k=0}^\infty A_kz^k$
$f'=\sum_{k=0}^\infty kA_kz^{k-1}$
$f''=\sum_{k=0}^\infty k(k-1)A_kz^{k-2}$
Substituting these in the differential equation
\begin{align} & {} \quad \sum_{k=0}^\infty k(k-1)A_kz^{k-2}-2z\sum_{k=0}^\infty kA_kz^{k-1}+\sum_{k=0}^\infty A_kz^k=0 \\ & =\sum_{k=0}^\infty k(k-1)A_kz^{k-2}-\sum_{k=0}^\infty 2kA_kz^k+\sum_{k=0}^\infty A_kz^k \end{align}
Making a shift on the first sum
\begin{align} & = \sum_{k+2=0}^\infty (k+2)((k+2)-1)A_{k+2}z^{(k+2)-2}-\sum_{k=0}^\infty 2kA_kz^k+\sum_{k=0}^\infty A_kz^k \\ & =\sum_{k=-2}^\infty (k+2)(k+1)A_{k+2}z^k-\sum_{k=0}^\infty 2kA_kz^k+\sum_{k=0}^\infty A_kz^k \\ & =(0)(-1)A_0 z^{-2} + (1)(0)A_{1}z^{-1}+\sum_{k=0}^\infty (k+2)(k+1)A_{k+2}z^k-\sum_{k=0}^\infty 2kA_kz^k+\sum_{k=0}^\infty A_kz^k \\ & =\sum_{k=0}^\infty (k+2)(k+1)A_{k+2}z^k-\sum_{k=0}^\infty 2kA_kz^k+\sum_{k=0}^\infty A_kz^k \\ & =\sum_{k=0}^\infty \left((k+2)(k+1)A_{k+2}+(-2k+1)A_k\right)z^k \end{align}
If this series is a solution, then all these coefficients must be zero, so:
$(k+2)(k+1)A_{k+2}+(-2k+1)A_k=0\;\!$
We can rearrange this to get a recurrence relation for Ak+2.
$(k+2)(k+1)A_{k+2}=-(-2k+1)A_k\;\!$
$A_{k+2}={(2k-1)\over (k+2)(k+1)}A_k\;\!$
Now, we have
$A_2 = {-1 \over (2)(1)}A_0={-1\over 2}A_0,\, A_3 = {1 \over (3)(2)} A_1={1\over 6}A_1$
We can determine A0 and A1 if there are initial conditions, i.e. if we have an initial value problem.
So we have
\begin{align} A_4 & ={1\over 4}A_2 = \left({1\over 4}\right)\left({-1 \over 2}\right)A_0 = {-1 \over 8}A_0 \\[8pt] A_5 & ={1\over 4}A_3 = \left({1\over 4}\right)\left({1 \over 6}\right)A_1 = {1 \over 24}A_1 \\[8pt] A_6 & = {7\over 30}A_4 = \left({7\over 30}\right)\left({-1 \over 8}\right)A_0 = {-7 \over 240}A_0 \\[8pt] A_7 & = {3\over 14}A_5 = \left({3\over 14}\right)\left({1 \over 24}\right)A_1 = {1 \over 112}A_1 \end{align}
and the series solution is
\begin{align} f & = A_0x^0+A_1x^1+A_2x^2+A_3x^3+A_4x^4+A_5x^5+A_6x^6+A_7x^7+\cdots \\[8pt] & = A_0x^0 + A_1x^1 + {-1\over 2}A_0x^2 + {1\over 6}A_1x^3 + {-1 \over 8}A_0x^4 + {1 \over 24}A_1x^5 + {-7 \over 240}A_0x^6 + {1 \over 112}A_1x^7 + \cdots \\[8pt] & = A_0x^0 + {-1\over 2}A_0x^2 + {-1 \over 8}A_0x^4 + {-7 \over 240}A_0x^6 + A_1x + {1\over 6}A_1x^3 + {1 \over 24}A_1x^5 + {1 \over 112}A_1x^7 + \cdots \end{align}
which we can break up into the sum of two linearly independent series solutions:
$f=A_0 \left(1+{-1\over 2}x^2+{-1 \over 8}x^4+{-7 \over 240}x^6+\cdots\right) + A_1\left(x+{1\over 6}x^3+{1 \over 24}x^5+{1 \over 112}x^7+\cdots\right)$
which can be further simplified by the use of hypergeometric series.
## A Simpler way using Taylor Series
A much simpler way of solving this equation (and power series solution in general) using the Taylor series form of the expansion. Here we assume the answer is of the form
$f=\sum_{k=0}^\infty A_kz^k\over {k!}$
If we do this, the general rule for obtaining the recurrence relationship for the coefficients is
$y^{[n]} -> A_{k+n}$
and
$x^m y^{[n]} -> (k)(k-1)...(k-m+1)A_{k+n-m}$
In this case we can solve the Hermite equation in fewer steps:
$f''-2zf'+\lambda f=0;\;\lambda=1$
becomes
$A_{k+2} -2kA_k +\lambda A_k=0$
or
$A_{k+2} = (2k-\lambda) A_k$
in the series
$f={\sum_{k=0}^\infty A_kz^k\over {k!}}$
## Nonlinear equations
The power series method can be applied to certain nonlinear differential equations, though with less flexibility. A very large class of nonlinear equations can be solved analytically by using the Parker-Sochacki method. Since the Parker-Sochacki method involves an expansion of the original system of ordinary differential equations through auxiliary equations, it is not simply referred to as the power series method. The Parker-Sochacki method is done before the power series method to make the power series method possible on many nonlinear problems. An ODE problem can be expanded with the auxiliary variables which make the power series method trivial for an equivalent, larger system. Expanding the ODE problem with auxiliary variables produces the same coefficients (since the power series for a function is unique) at the cost of also calculating the coefficients of auxiliary equations. Many times, without using auxiliary variables, there is no known way to get the power series for the solution to a system, hence the power series method alone is difficult to apply to most nonlinear equations.
The power series method will give solutions only to initial value problems (opposed to boundary value problems), this is not an issue when dealing with linear equations since the solution may turn up multiple linearly independent solutions which may be combined (by superposition) to solve boundary value problems as well. A further restriction is that the series coefficients will be specified by a nonlinear recurrence (the nonlinearities are inherited from the differential equation).
In order for the solution method to work, as in linear equations, it is necessary to express every term in the nonlinear equation as a power series so that all of the terms may be combined into one power series.
As an example, consider the initial value problem
$F F'' + 2 F'^2 + \eta F' = 0 \quad ; \quad F(1) = 0 \ , \ F'(1) = -\frac{1}{2}$
which describes a solution to capillary-driven flow in a groove. Note the two nonlinearities: the first and second terms involve products. Note also that the initial values are given at $\eta = 1$, which hints that the power series must be set up as:
$F(\eta) = \sum_{i = 0}^{\infty} c_i (\eta - 1)^i$
since in this way
$\frac{d^n F}{d \eta^n} \Bigg|_{\eta = 1} = n! \ c_n$
which makes the initial values very easy to evaluate. It is necessary to rewrite the equation slightly in light of the definition of the power series,
$F F'' + 2 F'^2 + (\eta - 1) F' + F' = 0 \quad ; \quad F(1) = 0 \ , \ F'(1) = -\frac{1}{2}$
so that the third term contains the same form $\eta - 1$ that shows in the power series.
The last consideration is what to do with the products; substituting the power series in would result in products of power series when it's necessary that each term be its own power series. This is where the Cauchy product
$\left(\sum_{i = 0}^{\infty} a_i x^i\right) \left(\sum_{i = 0}^{\infty} b_i x^i\right) = \sum_{i = 0}^{\infty} x^i \sum_{j = 0}^i a_{i - j} b_j$
is useful; substituting the power series into the differential equation and applying this identity leads to an equation where every term is a power series. After much rearrangement, the recurrence
$\sum_{j = 0}^i \left((j + 1) (j + 2) c_{i - j} c_{j + 2} + 2 (i - j + 1) (j + 1) c_{i - j + 1} c_{j + 1}\right) + i c_i + (i + 1) c_{i + 1} = 0$
is obtained, specifying exact values of the series coefficients. From the initial values, $c_0 = 0$ and $c_1 = -1/2$, thereafter the above recurrence is used. For example, the next few coefficients:
$c_2 = -\frac{1}{6} \quad ; \quad c_3 = -\frac{1}{108} \quad ; \quad c_4 = \frac{7}{3240} \quad ; \quad c_5 = -\frac{19}{48600} \ \dots$
A limitation of the power series solution shows itself in this example. A numeric solution of the problem shows that the function is smooth and always decreasing to the left of $\eta = 1$, and zero to the right. At $\eta = 1$, a slope discontinuity exists, a feature which the power series is incapable of rendering, for this reason the series solution continues decreasing to the right of $\eta = 1$ instead of suddenly becoming zero. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 37, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.992611825466156, "perplexity": 524.9594988824696}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-32/segments/1438042991019.80/warc/CC-MAIN-20150728002311-00105-ip-10-236-191-2.ec2.internal.warc.gz"} |
http://itfeature.com/testing-of-hypothesis/type-i-error | # Difference between a probability value and the significance level?
Basically in hypothesis testing the goal is to see if the probability value is less than or equal to the significance level (i.e., is p ≤ alpha). It is also called the size of the test or size of the critical region. It is generally specified before any samples are drawn so that the results obtained will not influence our choice.
• The probability value (also called the p-value) is the probability of the observed result found in your research study of occurring (or an even more extreme result occurring), under the assumption that the null hypothesis is true (i.e., if the null were true).
• In hypothesis testing, the researcher assumes that the null hypothesis is true and then sees how often the observed finding would occur if this assumption were true (i.e., the researcher determines the p-value).
• The significance level (also called the alpha level) is the cutoff value the researcher selects and then uses to decide when to reject the null hypothesis.
• Most researchers select the significance or alpha level of .05 to use in their research; hence, they reject the null hypothesis when the p-value is less than or equal to .05.
• The key idea of hypothesis testing it that you reject the null hypothesis when the p-value is less than or equal to the significance level of.05.
# Type I and Type II Errors
In hypothesis testing there are two possible errors we can make: Type I and Type II errors.
• A Type I error occurs when your reject a true null hypothesis (remember that when the null hypothesis is true you hope to retain it).
α=P(type I error)=P(Rejecting the null hypothesis when it is true)
Type I error is more serious than type II error and therefore more important to avoid that a type II error.
• A Type II error occurs when you fail to reject a false null hypothesis (remember that when the null hypothesis is false you hope to reject it).
β=P(type II error) = P(accepting null hypothesis when alternative hypothesis is true)
• The best way to allow yourself to set a low alpha level (i.e., to have a small chance of making a Type I error) and to have a good chance of rejecting the null when it is false (i.e., to have a small chance of making a Type II error) is to increase the sample size.
• The key in hypothesis testing is to use a large sample in your research study rather than a small sample!
If you do reject your null hypothesis, then it is also essential that you determine whether the size of the relationship is practically significant.
The hypothesis test procedure is therefore adjusted so that there is a guaranteed “low” probability of rejecting the null hypothesis wrongly; this probability is never zero.
# Type I Error
It has become part of the statistical hypothesis testing culture.
• It is a longstanding convention.
• It reflects a concern over making type I errors (i.e., wanting to avoid the situation where you reject the null when it is true, that is, wanting to avoid “false positive” errors).
• If you set the significance level at .05, then you will only reject a true null hypothesis 5% or the time (i.e., you will only make a type I error 5% of the time) in the long run. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8952564597129822, "perplexity": 327.08859698966853}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-22/segments/1495463613135.2/warc/CC-MAIN-20170529223110-20170530003110-00429.warc.gz"} |
https://www.physicsforums.com/threads/work-kinetic-energy.188202/ | # Work/ Kinetic Energy
1. Sep 30, 2007
### sheri1987
1. The problem statement, all variables and given/known data
With brakes fully applied, a 1670 kg car decelerates from a speed of 78.0 km/hr. What is the work done by the braking force in bringing the car to a stop?
What is the change in the kinetic energy of the car?
2. Relevant equations
W=f*s, KE= .5(m)(v^2)
3. The attempt at a solution
I am not sure if for the first answer how to start the problem, I have the mass, but I do not know the acceleration to solve for F...how can I go about solving this problem? Also for the second question I thought I would just have to use the equation for KE to solve, but it doesnt seem to be working...any suggestions?
2. Sep 30, 2007
### dynamicsolo
Have you had the work-kinetic energy theorem yet? In any case, you can answer part 2 right off: what was the KE of the car at the start? what is the KE at the end?
3. Sep 30, 2007
### Dick
The answers to both questions are the same. Energy is conserved, so the KE of the car is equal to the energy consumed by the braking force. If you are getting a wrong answer for the second part it's likely because you've overlooked that the speed is in km/hr. Not m/sec. Convert km/hr to m/sec.
4. Sep 30, 2007
### dynamicsolo
I was resisting pointing this out. I wanted to find out if the point of the problem was to discover that this is the case. (If her course has covered the W-KE theorem, then the answer to one part would point to the answer for the other...)
5. Sep 30, 2007
### sheri1987
for the second part of the problem do I use the equation KE =.5m(v^2) ....m= 1670, v = 78000 cause I have to convert it to m/hr....isn't the KE at the end 0, since the car stops? so wouldn't my answer be the final minus the inital?
6. Sep 30, 2007
### Dick
Yes but v=78000 is completely meaningless. What units? The usual units of energy are joules. In that case you want the speed in m/sec. 78000 certainly isn't right. Hint, 1hr=3600sec.
Last edited: Sep 30, 2007
7. Sep 30, 2007
### Dick
Apologies. You did say it was m/hr. But that's not the number you want to plug into (1/2)*mv^2 to get joules.
Similar Discussions: Work/ Kinetic Energy | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.899255096912384, "perplexity": 721.3318446312353}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-39/segments/1505818687324.6/warc/CC-MAIN-20170920142244-20170920162244-00086.warc.gz"} |
https://www.ventsistema.net/85ch5/2387f1-epidermis-example-of-a-tissue | # epidermis example of a tissue
Cuticle: Waxy, waterproof substance produced by epidermal cells of leaves, shoots, and other above-ground parts of plants; prevents damage and loss of water by evaporation. Root hairs are elongations of epidermal cells in the root. it is interrupted by stomata in many plants. Biology » Plant and Animal Tissues » Plant Tissues. The epidermis is the outermost layer of the three layers of skin. The meristematic tissues give rise to cells that perform a specific function. The dermis connects the epidermis to the hypodermis and provides structure and elasticity from collagen and elastin fibers. Epidermis: This system solely consists of the outermost skin or epidermis of all the plant organs beginning from the underground roots to the fruits and seeds.. Therefore, a microscopic examination of prepared epidermis sample was required to ensure sample collection only … In some plants addition to guard cells, specialised A tissue is a group of cells with the same origin that serve a similar function. Options. Guard cells control the opening and closing of the pores known as stomata thus controlling water loss in plants. Describe the shape of the guard cells and normal epidermal cells. Stomata in a tomato leaf as seen under a scanning electron microscope. Ocimum) or non-glandular. are minute pores surrounded by two guard cells. Together, the stoma and the guard cells are referred to as stomata. In some older works the cells of the leaf epidermis have been regarded as specialized parenchyma cells, but the established modern preference has long been to classify the epidermis as dermal tissue, whereas parenchyma is classified as ground tissue. Prickles also provide protection against animals layer of the root has two types of epidermal cells, long cells and short cells. protective in function and forms the outermost layer of the stem. and ‘Derma’. The rows of cells develop from stem cell In Nerium, in the … The stomata occur mainly in the Did You Know? Large stem cells, termed basal cells, dominate the stratum basale. They are live cells. appendages that originate, Piliferous In many plants it The upper and lower epidermis of the leaf are examples of protective tissue. The cells are compactly and are one or more one celled thick. The short cells are called trichoblasts. Epidermal pores may be present here Adjust lighting if necessary and draw one stoma and its guard cells. The epidermis of the mammalian skin is an example. They In some rose plants they also help in climbing. $$\overset{\underset{\mathrm{def}}{}}{=}$$, Investigation: Practical Investigation of Leaf Epidermis. upper and lower epidermis. them. The cuticle is The epidermis is the outermost cell layer of the primary plant body. is also mixed wax to form epicuticular wax. It consists of relatively unspecialised cells with thin cell walls. Enlarge the part of the specimen you chose and focus on high power. Tissues in the Leaf. The leaf epidermis is single layered, but in certain leaves, multilayered upper A) prevent light from passing through them. layer called cuticle. Epidermal tissues in leaves are covered with a waxy cuticle. The minute openings found on the The epidermis is usually made of a single layer of cells. epidermis dermis a fatty layer (hypodermis) lies deep to it on the number and arrangement of subsidiary cells around the guard cells, the These cells are helpful The epidermis is the outermost of three main skin layers.The outermost one is called the epidermis. In Ficus upper epidermal layer contains Epidermis: Every living organism is made up of multiple cells, or basic units of all life. The epidermis is composed of multiple layers of flattened cells that overlie a base layer composed of columnar cells arranged perpendicularly. While the epidermis is composed of epithelial cells, the dermis is composed of connective tissue. water due to the presence of cuticle. Connective Tissue. are called. cells. Chloroplasts are usually absent except Generally, epidermis is single layered, but in certain leaves, multilayered upper epidermis is present, Example: Ficus, Nerium, and Peperomea. Epidermal tissue system . Main Difference – Dermis vs Epidermis. See more. Stomata epidermis of leaves. The first is the epidermis. in guard cells of stomata. is in direct contact with external environment. They are usually loosely packed, so that large spaces between cells (intercellular spaces) are found in this tissue. The outer walls of epidermal cells have a Epidermis protects the underlying tissues. cells of upper epidermis (Example: Grasses) are larger and thin walled. It They Epidermal hairs can also be in the form of Your browser seems to have Javascript disabled. A stoma is surrounded by a pair of specialized epidermal cells called guard They are called silica cells. for the rolling and unrolling of the leaf according to the weather change. The stomata occur mainly in the Dermis and epidermis are basically protective outer layers of the body. epidermal cells are present which are distinct from other epidermal cells. Register or login to make commenting easier. 7. This upward migrati… Example: styrax, many members Label all parts. The skin is connective tissue that consists of cells, fibers and an extracellular matrix. It is devoid of Epidermis is derived from two Greek words, namely ‘Epi’ grasses and sedges, the guard cells are dumbbell- shaped. loss by transpiration. exchange. However, three or more tear-offs of the same leaf sample increased the chance of a sample contamination with mesophyll tissue. The epidermis is primarily a covering layer which helps in the protection of the internal soft tissues against mechanical injury. Cultured Epidermis. The main difference between epidermis and epithelium is that epidermis is the outermost protective layer of the skin of animals whereas epithelium is one of the four types of tissues in the animal body, which lines the internal and external surfaces of the body. of the epidermal cells of the grasses are filled with silica. D) are impregnated with keratin …of the stem compose the epidermis. Simple Permanent Tissues: Parenchyma, Collenchyma, Sclerenchyma, Difference Between Different types of tissues, Introduction to Tissue System, Types and Characteristics of tissue System, Primary Structure of Dicot Root - Bean Root, Primary Structure of Monocot Root-maize Root, Anatomical differences between dicot root and monocot root, Anatomy and Primary Structure of Dicot stem - sunflower stem, Anatomy and Primary Structure of Monocot Stem-maize Stem. The outer In some situations, it contains chlorophyll and performs … appendages that originate from the epidermal cells are called trichomes. and they also check excessive transpiration. 1. This single layer of cells is firmly attached to the basal lamina, which separates the epidermis from the loose connective tissue of the adjacent dermis. Simple Cuboidal ET can be found where. epidermal pores and cuticle. Skin is the largest organ of the human body. Description. Autologous Cultured Epidermis. Trichomes may be branched or unbranched ‘Epi’ means upon and They A simple tissue is called epithelium in animals and epidermis in plants. Xerophytic plants (Examples: Cycas, Nerium), stomata is sunken beneath the epidermal cells are present which are distinct from other epidermal cells. cystoliths made up of calcium carbonate crystals. Generally the cuticle on the upper epidermis 3. Trichoblasts are elongate into root hairs. Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail. In angiosperm: Dermal tissue …is the source of the periderm, a protective tissue that replaces the epidermis when the secondary growth displaces, and ultimately destroys, the epidermis … It is Chlorenchyma. It is at its thinnest on the eyelids, measuring just half a millimeter, and at its thickest on the palms and soles at 1.5 millimeters. Cells of epidermis are elongated and flattened, without intercellular space. Generally, Unless specified, this website is not in any way affiliated with any of the institutions featured. It is made up of single layer of parenchyma cells The thickness of the epidermis varies depending on where on the body it is located. Some exchange. This leads to an increase in the swelling of the guard cells and the stomatal pores open. integument is skin. xylem vessels (made up of tracheids and vessels), phloem vessels (made up of sieve tubes and companion cells), Rip a piece of leaf lengthwise and check for “thinner bits” near the edges, which will be epidermal tissue (ensure that you have LOWER epidermis because this is where the guard cells are found.). stomata are more in number on the lower epidermis than on the upper epidermis. 2. The epidermis is usually one cell layer thick, and its cells lack chloroplasts.…. Epidermal cells are living. Generally, Piliferous Epidermis is defined as the outer layer of skin, cells or tissue. The short cells are called. We will examine two types of permanent tissue: The epidermis is a single layer of cells that covers plants’ leaves, flowers, roots and stems. Epidermis protects the underlying tissues. and sharp in appearance. It is a plant tissue formed of thin and densely packed cells, meant to separate the inside of the organisms from the outside. is generally dorsiventral. An average adult has a total surface area of around 1.6 m 2 of skin, which if subcutaneous tissue is included weighs around 9 kg. The epidermis is the outermost layer of the plant's primary body. The stoma is bordered on either side by a pair of specialised cells known as guard cells. The main difference between dermis and epidermis is that dermis is a tissue below the epidermis, containing living cells whereas epidermis is the outermost part of the body, protecting it from dehydration, trauma, and infections.The dermis of animals is found in the skin and is … abaxial leaf surface within stomatal crypts. various types of stomata are recognised. Based Stomata is involved in transpiration and gaseous Epidermis, "epi" coming from the Greek meaning "over" or "upon", is the outermost layer of the skin.It forms the waterproof, protective wrap over the body's surface which also serves as a barrier to infection and is made up of stratified squamous epithelium with an underlying basal lamina.. The guard cells and subsidiary cells The unicellular or multicellular keratinized stratified. These cells are tightly packed, form a continuous sheet and are almost without any intercellular spaces between them. epidermis is single layered, but in certain leaves, multilayered upper Once cells develop to perform this particular function, they lose their ability to divide. contain chloroplasts, whereas the other epidermal cells normally do not have Root hairs maximise the surface area over which absorption of water from the soil can occur. The sunken stomata reduce water may also be glandular (Example: Rose, are called Subsidiary cells. When guard cells take up these solutes, the water potential decreases causing osmotic water to flow into the guard cells. The guard cells The deepest epidermal layer is the stratum basale or stratum germinativum. Epidermis definition, the outer, nonvascular, nonsensitive layer of the skin, covering the true skin or corium. Components of plant epidermal tissue Epidermis . In some rose plants they also help in climbing. are minute pores surrounded by two guard cells. In leaf epidermis there are a number of epidermal cells arranged in … Consists of organs including the skin, hair, nails, sweat and sebaceous glands, and associated muscle and nervous tissue. The chemicals in trichomes make plants less easily digested by hungry animals and can also slow down the growth of fungus on the plant. The outer walls of epidermal cells have a Its thickness depends on where it is located on the body. In some plants addition to guard cells, specialised derived from protoderm. Although epidermis is a continuous outer layer, water due to the presence of cuticle. many types of epidermal outgrowths in stems. The another important function of piliferous layer is protection. Save my name, email, and website in this browser for the next time I comment. Stomata is involved in transpiration and gaseous Tissue means a number of cells coming together to perform a common function. When cells of the same type work together to perform a collective function, the collection of cells is called a tissue.For example, the epidermis is a collection of parenchyma-like cells working together to separate the internal environment of the plant from the exterior. As such they act as a form of protection for the plant against predation. There are five layers of the epidermis: 2. B) have a similar structure and function. In many plants a large number of epidermal hairs layer of the root is known as piliferous layer or epiblema. For example, it's thinnest on the eyelids (half a millimeter). It is a This modified article is licensed under a CC BY-NC-SA 4.0 license. Epidermal tissue system is the outer most covering of plants. Protective tissues are a part of plant tissue system. We're sorry, but in order to log in and use all the features of this website, you will need to enable JavaScript in your browser. cells of upper epidermis (Example: Grasses) are larger and thin walled. C) prevent excessive loss of water. Guard cells are bean shaped specialised epidermal cells found mainly on the lower surface of leaves which are responsible for regulating the size of the stoma opening. many types of epidermal outgrowths in stems. Usually, It is the outermost cell layer of the plant body and plays a protective role in the plant. There are Epidermis: It is the outermost protective layer of plant organs. While in The function of key structural features are listed in the table below. Don't want to keep filling in name and email whenever you want to comment? Leaf trichomes trap water in the area above the stomata and prevent water loss. stellate hairs (star shaped) present in plants. 4. are one type of epidermal emergences with no vascular supply. This layer represents the point of contact between the plants and the outer environment and, as such exhibits diversities in structure. Copyright © 2018-2021 BrainKart.com; All Rights Reserved. Focus the slide on low power and search for a section of the sample that does not have air bubbles over the stomata. Layer of cells covering surface of entire plant. water and mineral salts from the soil. But it … The epidermis is often covered in a layer of waxy protection, to stop the plant from burning or drying out in the sun. and they also check excessive transpiration. It is made of long cells, compactly arranged to form a continuous layer. 6. The waxy outer layer on the epidermis prevents water loss from leaves. In Nerium , in the multilayered epidermis The guard cells also contain chloroplasts for photosynthesis. It is always recommended to visit an institution's official website for more information. This tissue has a high regeneration capacity, lacks blood vessels, and is richly innervated. epidermis and; cork. Protective tissues include . The dermal tissue system—the epidermis—is the outer protective layer of the primary plant body (the roots, stems, leaves, flowers, fruits, and seeds). The epidermis is made of four main layers and functions by protecting and safeguarding the internal cells and tissues. A stoma is a pore found in the leaf and stem epidermis that allows for gaseous exchange. epithelial tissue. epidermis is present, Example: There are This is a lesson from the tutorial, Plant and Animal Tissues and you are encouraged to log in or register, so that you can track your progress. Epidermal tissues contain guard cells containing chloroplasts. Guard cells control the opening and closing of the pores known as. made up of cutin. As basal cells undergo mitosis, new keratinocytes are formed and move into the more superficial layers of the epidermis. They are stiff Epidermal tissue system is the outermost covering of plants. help in opening and closing of stomata during gaseous exchange and transpiration. which are arranged compactly without intercellular spaces. Prickles, Of a tissue because the cells. seeds and fruits, and provide protection against animals. epidermis of leaves. The unicellular or multicellular This tissue is composed of epidermal cells, which are clustered cells that secrete a waxy cuticle, which plays a role in preventing water loss. Adipose tissue _____ _____ squamous epithelial tissue forms the epidermis of skin. It is a Epidermis definition is - the outer epithelial layer of the external integument of the animal body that is derived from the embryonic epiblast; specifically : the outer nonsensitive and nonvascular layer of the skin of a vertebrate that overlies the dermis. The skin on your body is an example of epidermis. (BS) Developed by Therithal info, Chennai. The stomata in the epidermis allow oxygen, carbon dioxide and water vapour to enter and leave the leaf. The epidermis in plants serves the same function as it does in animals. Scanning electron microscope image of Nicotiana alata (tobacco plant) upper leaf surface, showing trichomes (also known as hairs’) and a few stomata. Trichomes are also helpful in the dispersal of protective in function and forms the outermost layer of the stem. The three main tissue systems in plants are the epidermis, ground tissue, and vascular tissue. single layer of parenchymatous rectangular cells. In some The epidermis is the thin outer layer of skin, the dermis is the thicker inner layer of skin. Glandular hairs repel herbivorous animals. It has It consists of epidermis This tissue is parenchyma, a type of permanent tissue. An example of … is thicker than that of lower epidermis. and there. The epidermis is usually made up of a single layer Skin covers the human body completely. of Malvaceae and Solanaceae. (Example: Rose). The turgor pressure is controlled by movements of large quantities of ions and sugar into the guard cells. In most dicots and monocots the guard cells are bean-shaped. The four main types of animal tissues are connective, nervous, muscle, and epithelial tissues. tissue system is the outer most covering of plants. arranged without intercellular cells. seeds and fruits, and provide protection against animals. ‘Derma’ means skin. The epidermis is the outermost layer of the skin. 2. Some Root hair is always single celled, it absorbs Tissues are found in animals and plants. It is Simple tissue is made up of the same type of cells and mostly covers the surface of both, internal organs of the body and external organs of the body. are called, Stomata The epidermis is the outermost of the three layers that make up the skin, the inner layers being the dermis and hypodermis. All names, acronyms, logos and trademarks displayed on this website are those of their respective owners. This system in the shoot checks excessive loss of The above is a microscopic image of an Arabidopsis thaliana (commonly known as Thale cress’ or `mouse ear’) stoma showing two guard cells exhibiting green fluorescence, with chloroplasts staining red. Glandular hairs repel herbivorous animals. Opening and closing of the guard cells is determined by the turgor pressure of the two guard cells. Epidermis is generally composed of single layer of parenchymatous cells compactly arranged without intercellular spaces. It consists of epidermis, stomata and epidermal outgrowths. Simple tissue is tightly packed together. are called bulliform cells or motor cells. layer called, Some E.g., skin, the lining of the mouth, the lining of blood vessels, lung alveoli and kidney tubules are all made of epithelial tissue. The cells are compactly The epidermis is the outermost layer of the skin, which is composed of cells called keratinocytes – made of a protein called keratin. layer of the root has two types of epidermal cells, long cells and short cells. They This system in the shoot checks excessive loss of The cuticle single layer of parenchymatous rectangular cells. In Ficus upper epidermal layer contains cystoliths made up of calcium carbonate crystals. These proteins are made by fibroblasts found in the dermis. What's an example of connective tissue proper? Epithelial tissues are the covering or protective tissues and cover most organs and cavities in the animal body. The process of developing a particular structure suited to a specific function is known as cellular differentiation. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the amount of water released from the body into the atmosphere through transepidermal water loss. They 5. Prickles also provide protection against animals Vocabulary. They assume many shapes and sizes. Trichomes are also helpful in the dispersal of It’s thin but durable and acts as a protective barrier … It's thickest on the palms of the hands and soles of the feet (1.5 millimeters). arranged without intercellular cells. occur on the epidermis. the outer layer alone is cutinized. It prevents excessive evaporation of water from the internal tissues, for this, several adaptations like development of thick cuticle, wax, hairs, etc., take place. Epidermal The below mentioned article provides an overview on the epidermal tissue system of plants. This tissue provides support to plants and also stores food. Register or login to receive notifications when there's a reply to your comment or update on this information. epidermis is present, Example: Ficus, Nerium, and Peperomea. Cover with a cover slip. checks transpiration . The waxy outer layer on the epidermis prevents water loss from leaves. Some plant epidermal cells can secrete poisonous or bad-tasting substances. of cells that are closely packed. Organizing and providing relevant educational content, resources and information for students. epidermis are called stomata (singular: stoma). Use the scissors to cut off a small section of epidermis and mount it in water on a microscope slide. No bark is formed on the herbaceous stem. Ions and sugar into the more superficial layers of flattened cells that overlie a base composed. Protection against animals and they also check excessive transpiration arranged perpendicularly a stoma is plant... Any way affiliated with any of the same leaf sample increased the chance of a sample contamination with mesophyll.... To a specific function is known as water to flow into the guard cells control the opening closing! Next time I comment ( half a millimeter ) outer most covering plants. Outer layers of the guard cells control the opening and closing of the plant.! Or protective tissues are the epidermis prevents water loss from leaves tissue has a regeneration! Of large quantities of ions and sugar into the guard cells tissues are a part of plant system... ( intercellular spaces it is a single layer of cells with thin cell walls the cells... Support to plants and also stores food the plants and the guard cells by two guard cells, meant separate! Formed of thin and densely packed cells, the water potential decreases causing osmotic water flow! Upper epidermal layer contains cystoliths made up of single layer of the human body pressure of the body it also. Absorption of water from the epidermal tissue system is the outermost protective layer of the pores known stomata! It consists of epidermis are called trichomes multiple cells, specialised epidermal cells, fibers and an matrix! Rolling and unrolling of the guard cells of upper epidermis ( example: grasses ) are larger and walled! Outer walls of epidermal cells are bean-shaped Every living organism is epidermis example of a tissue of four main types stomata! Stoma is bordered on either side by a pair of specialised cells known as layer. Is generally composed of multiple cells, compactly arranged without intercellular spaces point of contact the! Where it is located stop the plant from burning or drying out in epidermis! Absorbs water and mineral salts from the outside are many types of animal tissues » plant and animal tissues a! Covering the true skin or corium the part of plant tissue formed of thin and densely packed cells, basal. Compactly without intercellular spaces of stomata during gaseous exchange and transpiration multiple cells, stoma. Derived from two Greek words, namely ‘ Epi ’ and ‘ Derma ’ mixed wax to form a layer... Single layer of the pores known as the outermost covering of plants one celled thick to a specific function turgor! Upper and lower epidermis than on the epidermal tissue system is the outermost covering of plants of subsidiary cells in! Occur mainly in the epidermis is a single layer of cells that are packed! And short cells migrati… What 's an example of epidermis pore found in this browser for plant... To stop the plant body, nonvascular, nonsensitive layer of parenchymatous rectangular cells during gaseous.. The form of stellate hairs ( star shaped ) present in plants the... Function and forms the epidermis of the plant from burning or drying in... Website in this browser for the plant are found in the table below a single layer of the cells... More information and mineral salts from the epidermal cells are dumbbell- shaped epidermis oxygen... Stomata are minute pores surrounded by two guard cells arranged to form a continuous layer a protective in., carbon dioxide and water vapour to enter and leave the leaf allows for gaseous exchange subsidiary cells around guard... The process of developing a particular structure suited to a specific function outgrowths stems! Give rise to cells that overlie a base layer composed of connective tissue that consists of relatively unspecialised cells thin! One is called epithelium in animals and can also be in the root is known cellular... Plant from burning or drying out in the shoot checks excessive loss of water due to the presence of.. Cells develop to perform this particular function, they lose their ability to.... Off a small section of epidermis are called, stomata is sunken beneath the abaxial leaf within! Epidermis and mount it in water on a microscope slide of leaves meristematic tissues give rise to cells that a!, a type of permanent tissue of columnar cells arranged perpendicularly most covering of plants this information is! Alone is cutinized are formed and move into the more superficial layers of flattened cells that a... | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.47260692715644836, "perplexity": 4908.956176686364}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-49/segments/1637964358786.67/warc/CC-MAIN-20211129164711-20211129194711-00015.warc.gz"} |
https://paperswithcode.com/paper/neural-machine-translation | # Neural Machine Translation
22 Sep 2017Philipp Koehn
Draft of textbook chapter on neural machine translation. a comprehensive treatment of the topic, ranging from introduction to neural networks, computation graphs, description of the currently dominant attentional sequence-to-sequence model, recent refinements, alternative architectures and challenges... (read more)
PDF Abstract
125 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8273956179618835, "perplexity": 13559.83382797486}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-18/segments/1555578711882.85/warc/CC-MAIN-20190425074144-20190425100144-00530.warc.gz"} |
http://www.self.gutenberg.org/articles/eng/Unitary_transformation | #jsDisabledContent { display:none; } My Account | Register | Help
# Unitary transformation
Article Id: WHEBN0000236007
Reproduction Date:
Title: Unitary transformation Author: World Heritage Encyclopedia Language: English Subject: Collection: Publisher: World Heritage Encyclopedia Publication Date:
### Unitary transformation
In mathematics, a unitary transformation is a transformation that preserves the inner product: the inner product of two vectors before the transformation is equal to their inner product after the transformation.
## Contents
• Formal definition 1
• Properties 2
• Unitary operator 3
• Antiunitary transformation 4
## Formal definition
More precisely, a unitary transformation is an isomorphism between two Hilbert spaces. In other words, a unitary transformation is a bijective function
U:H_1\to H_2\,
where H_1 and H_2 are Hilbert spaces, such that
\langle Ux, Uy \rangle_{H_2} = \langle x, y \rangle_{H_1}
for all x and y in H_1.
## Properties
A unitary transformation is an isometry, as one can see by setting x=y in this formula.
## Unitary operator
In the case when H_1 and H_2 are the same space, a unitary transformation is an automorphism of that Hilbert space, and then it is also called a unitary operator.
## Antiunitary transformation
A closely related notion is that of antiunitary transformation, which is a bijective function
U:H_1\to H_2\,
between two complex Hilbert spaces such that
\langle Ux, Uy \rangle = \overline{\langle x, y \rangle}=\langle y, x \rangle
for all x and y in H_1, where the horizontal bar represents the complex conjugate. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9697182774543762, "perplexity": 2381.3045851192196}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-26/segments/1560627999783.49/warc/CC-MAIN-20190625011649-20190625033649-00171.warc.gz"} |
http://dcx.sap.com/1001/en/dbdaen10/da-filename-database-dbengine.html | SQL Anywhere 10.0.1 » SQL Anywhere Server - Database Administration » The Database Server » The SQL Anywhere database server » Database server options
### @data server option
Reads in options from the specified environment variable or configuration file.
###### Syntax
{ dbsrv10 | dbeng10 } @data ...
###### Applies to
All operating systems and servers, as well as all database utilities except the Language Selection utility (dblang), the Rebuild utility (rebuild), the Certificate Creation utility (createcert), the Certificate Viewer utility (viewcert), the ActiveSync provider install utility (mlasinst), and the File Hiding utility (dbfhide).
###### Remarks
Use this option to read in command line options from the specified environment variable or configuration file. If both exist with the same name that is specified, the environment variable is used.
Configuration files can contain line breaks, and can contain any set of options. See Using configuration files.
If you want to protect the information in a configuration file (for example, because it contains passwords) you can use the File Hiding (dbfhide) utility to obfuscate the contents of configuration files. See File Hiding utility (dbfhide).
The @data parameter can occur at any point in the command line, and parameters contained in the file are inserted at that point. Multiple files can be specified, and the file specifier can be used with command line options.
###### Example
The following configuration file holds a set of options for a server named myserver that starts with a cache size of 4 MB and loads the sample database:
```-c 4096
-n myserver
"c:\mydatabase.db"```
If this configuration file is saved as c:\config.txt, it can be used in a command as follows:
`dbsrv10 @c:\config.txt`
The following configuration file contains comments:
```#This is the server name:
-n MyServer
#These are the protocols:
-x tcpip
#This is the database file
my.db```
The following statement, entered all on one line, sets an environment variable that holds options for a database server that starts with a cache size of 4 MB and loads the sample database.
`set envvar=-c 4096 "c:\mydatabase.db"`
This statement starts the database server using an environment variable named envvar.
`dbsrv10 @envvar` | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8460282683372498, "perplexity": 4462.200365200447}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-13/segments/1552912203529.38/warc/CC-MAIN-20190324230359-20190325012359-00210.warc.gz"} |
https://love2d.org/forums/viewtopic.php?f=5&t=1053&start=190 | ## middleclass & extras: middleclass 3.0 is out!
kikito
Inner party member
Posts: 3068
Joined: Sat Oct 03, 2009 5:22 pm
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
I'm glad I can help. Stateful is the next thing I'll update - either this week or the next one.
When I write def I mean function.
bartbes
Sex machine
Posts: 4685
Joined: Fri Aug 29, 2008 10:35 am
Location: The Netherlands
### Re: middleclass & extras: middleclass 2.0 is out!
No Class Commons? I am disappoint.
Cowardly acts and the eating of birds must not be the deeds of a Hero of Storms.
kikito
Inner party member
Posts: 3068
Joined: Sat Oct 03, 2009 5:22 pm
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
It's on my list! But I need to do this first, sorry
When I write def I mean function.
TechnoCat
Inner party member
Posts: 1610
Joined: Thu Jul 30, 2009 12:31 am
Location: Chicago, IL
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
kikito wrote::neko: I'm glad I can help. Stateful is the next thing I'll update - either this week or the next one.
EDIT: Actually, I see you have been updating it. I'll see what is wrong.
EDIT2: OH! stateful is its own separate repo now. Gotcha. And it works.
Code: Select all
Stateful = require 'stateful.stateful'
kikito
Inner party member
Posts: 3068
Joined: Sat Oct 03, 2009 5:22 pm
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
Hi technocat,
I'm afraid that I haven't been able to release it yet. Sorry about that. I've been a bit ill and real life had me working on other things.
It's approaching completion, though. The main functionality is already there - only secondary stuff is left (for example, callbacks are not invoked when popAllStates is called; isInState isn't implemented, and states are not included in mixins - althought I might leave that one out)
As a side note, I've decided that from now on it will be my policy to not provide a folder, but a self-contained file for all my libs. This way you will not need a require 'stateful.stateful' (which in some cases gives trouble to physfs) but simply require 'stateful'.
Regards, and apologies for the delay!
When I write def I mean function.
TechnoCat
Inner party member
Posts: 1610
Joined: Thu Jul 30, 2009 12:31 am
Location: Chicago, IL
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
kikito wrote:Hi technocat,
I'm afraid that I haven't been able to release it yet. Sorry about that. I've been a bit ill and real life had me working on other things.
It's approaching completion, though. The main functionality is already there - only secondary stuff is left (for example, callbacks are not invoked when popAllStates is called; isInState isn't implemented, and states are not included in mixins - althought I might leave that one out)
My minuscule needs seem to have already been met. It seems to work without any problems.
I made this with middleclass 2.0 and the new stateful. (and Tween)
Attachments
splash.love
0.7.2
TechnoCat
Inner party member
Posts: 1610
Joined: Thu Jul 30, 2009 12:31 am
Location: Chicago, IL
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
Do class declarations have to be global?
http://i.imgur.com/xIJBO.png
I tried doing this and it keeps giving me an upvalue boolean error when I require it in another file and do :new on the returned object.
Code: Select all
local Shmup = class('Shmup')function Shmup:initialize()endfunction Shmup:update(dt)endfunction Shmup:draw()endreturn Shmup
kikito
Inner party member
Posts: 3068
Joined: Sat Oct 03, 2009 5:22 pm
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
TechnoCat wrote:Do class declarations have to be global?
As far as I know, no.
TechnoCat wrote:I tried doing this and it keeps giving me an upvalue boolean error when I require it in another file and do :new on the returned object.
That is weird.
Can you include inspect.lua in your main and print the Shmup variable on the console?
Code: Select all
local inspect = require 'inspect'local Shmup = require 'Shmup'puts(inspect(Shmup))
Does it work if you make Shmup global?
Last edited by kikito on Fri Oct 14, 2011 9:20 am, edited 1 time in total.
When I write def I mean function.
Robin
The Omniscient
Posts: 6496
Joined: Fri Feb 20, 2009 4:29 pm
Location: The Netherlands
Contact:
### Re: middleclass & extras: middleclass 2.0 is out!
You spend too much time with Ruby.
kikito
Inner party member
Posts: 3068
Joined: Sat Oct 03, 2009 5:22 pm | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5724844336509705, "perplexity": 11065.391070811833}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-44/segments/1476988718278.43/warc/CC-MAIN-20161020183838-00107-ip-10-171-6-4.ec2.internal.warc.gz"} |
https://en.wikipedia.org/wiki/Liouville%27s_theorem_(complex_analysis) | # Liouville's theorem (complex analysis)
In complex analysis, Liouville's theorem, named after Joseph Liouville, states that every bounded entire function must be constant. That is, every holomorphic function f for which there exists a positive number M such that ${\displaystyle |f(z)|\leq M}$ for all ${\displaystyle z}$ in ${\displaystyle \mathbb {C} }$ is constant. Equivalently, non-constant holomorphic functions on ${\displaystyle \mathbb {C} }$ have dense images.
The theorem is considerably improved by Picard's little theorem, which says that every entire function whose image omits at least two complex numbers must be constant.
## Proof
The theorem follows from the fact that holomorphic functions are analytic. If f is an entire function, it can be represented by its Taylor series about 0:
${\displaystyle f(z)=\sum _{k=0}^{\infty }a_{k}z^{k}}$
where (by Cauchy's integral formula)
${\displaystyle a_{k}={\frac {f^{(k)}(0)}{k!}}={1 \over 2\pi i}\oint _{C_{r}}{\frac {f(\zeta )}{\zeta ^{k+1}}}\,d\zeta }$
and Cr is the circle about 0 of radius r > 0. Suppose f is bounded: i.e. there exists a constant M such that |f(z)| ≤ M for all z. We can estimate directly
${\displaystyle |a_{k}|\leq {\frac {1}{2\pi }}\oint _{C_{r}}{\frac {|f(\zeta )|}{|\zeta |^{k+1}}}\,|d\zeta |\leq {\frac {1}{2\pi }}\oint _{C_{r}}{\frac {M}{r^{k+1}}}\,|d\zeta |={\frac {M}{2\pi r^{k+1}}}\oint _{C_{r}}|d\zeta |={\frac {M}{2\pi r^{k+1}}}2\pi r={\frac {M}{r^{k}}},}$
where in the second inequality we have used the fact that |z|=r on the circle Cr. But the choice of r in the above is an arbitrary positive number. Therefore, letting r tend to infinity (we let r tend to infinity since f is analytic on the entire plane) gives ak = 0 for all k ≥ 1. Thus f(z) = a0 and this proves the theorem.
## Corollaries
### Fundamental theorem of algebra
There is a short proof of the fundamental theorem of algebra based upon Liouville's theorem.[1]
### No entire function dominates another entire function
A consequence of the theorem is that "genuinely different" entire functions cannot dominate each other, i.e. if f and g are entire, and |f| ≤ |g| everywhere, then f = α·g for some complex number α. Consider that for g=0 the theorem is trivial so we assume g${\displaystyle \neq }$0. Consider the function h = f/g. It is enough to prove that h can be extended to an entire function, in which case the result follows by Liouville's theorem. The holomorphy of h is clear except at points in g−1(0). But since h is bounded and all the zeroes of g are isolated, any singularities must be removable. Thus h can be extended to an entire bounded function which by Liouville's theorem implies it is constant.
### If f is less than or equal to a scalar times its input, then it is linear
Suppose that f is entire and |f(z)| is less than or equal to M|z|, for M a positive real number. We can apply Cauchy's integral formula; we have that
${\displaystyle |f'(z)|={\frac {1}{2\pi }}\left|\oint _{C_{r}}{\frac {f(\zeta )}{(\zeta -z)^{2}}}d\zeta \right|\leq {\frac {1}{2\pi }}\oint _{C_{r}}{\frac {\left|f(\zeta )\right|}{\left|(\zeta -z)^{2}\right|}}\left|d\zeta \right|\leq {\frac {1}{2\pi }}\oint _{C_{r}}{\frac {M\left|\zeta \right|}{\left|(\zeta -z)^{2}\right|}}\left|d\zeta \right|={\frac {MI}{2\pi }}}$
where I is the value of the remaining integral. This shows that f' is bounded and entire, so it must be constant, by Liouville's theorem. Integrating then shows that f is affine and then, by referring back to the original inequality, we have that the constant term is zero.
### Non-constant elliptic functions cannot be defined on C
The theorem can also be used to deduce that the domain of a non-constant elliptic function f cannot be C. Suppose it was. Then, if a and b are two periods of f such that ab is not real, consider the parallelogram P whose vertices are 0, a, b and a + b. Then the image of f is equal to f(P). Since f is continuous and P is compact, f(P) is also compact and, therefore, it is bounded. So, f is constant.
The fact that the domain of a non-constant elliptic function f can not be C is what Liouville actually proved, in 1847, using the theory of elliptic functions.[2] In fact, it was Cauchy who proved Liouville's theorem.[3][4]
### Entire functions have dense images
If f is a non-constant entire function, then its image is dense in C. This might seem to be a much stronger result than Liouville's theorem, but it is actually an easy corollary. If the image of f is not dense, then there is a complex number w and a real number r > 0 such that the open disk centered at w with radius r has no element of the image of f. Define g(z) = 1/(f(z) − w). Then g is a bounded entire function, since
${\displaystyle (\forall z\in \mathbb {C} ):|g(z)|={\frac {1}{|f(z)-w|}}<{\frac {1}{r}}\cdot }$
So, g is constant, and therefore f is constant.
## Remarks
Let C ∪ {∞} be the one point compactification of the complex plane C. In place of holomorphic functions defined on regions in C, one can consider regions in C ∪ {∞}. Viewed this way, the only possible singularity for entire functions, defined on CC ∪ {∞}, is the point ∞. If an entire function f is bounded in a neighborhood of ∞, then ∞ is a removable singularity of f, i.e. f cannot blow up or behave erratically at ∞. In light of the power series expansion, it is not surprising that Liouville's theorem holds.
Similarly, if an entire function has a pole at ∞, i.e. blows up like zn in some neighborhood of ∞, then f is a polynomial. This extended version of Liouville's theorem can be more precisely stated: if |f(z)| ≤ M.|zn| for |z| sufficiently large, then f is a polynomial of degree at most n. This can be proved as follows. Again take the Taylor series representation of f,
${\displaystyle f(z)=\sum _{k=0}^{\infty }a_{k}z^{k}.}$
The argument used during the proof using Cauchy estimates shows that
${\displaystyle (\forall k\in \mathbb {N} ):|a_{k}|\leqslant Mr^{n-k}.}$
So, if k > n,
${\displaystyle |a_{k}|\leqslant \lim _{r\rightarrow +\infty }Mr^{n-k}=0.}$
Therefore, ak = 0.
Liouville's theorem does not extend to the generalizations of complex numbers known as double numbers and dual numbers.[5] | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 13, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9922842383384705, "perplexity": 221.6842980552391}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-40/segments/1474738660350.13/warc/CC-MAIN-20160924173740-00247-ip-10-143-35-109.ec2.internal.warc.gz"} |
https://math.stackexchange.com/questions/2601712/probability-and-statistic-with-distribution | # Probability and statistic with distribution [closed]
Suppose X has an exponential distribution with $E[X] = 3$. Suppose Y has a uniform distribution on $[0, 5]$. Suppose X and Y are independent.
• (a) Find $P(X≤1)$.
• (b) Find the joint density of X and Y .
I know exponential pdf is $\lambda e^{-\lambda x}$, but I don't know how to get $\lambda$ in computing $\int_{0}^{1} \lambda e^{-\lambda x} dx$
I don't know how to start (b). Please help.
## closed as off-topic by Chappers, GNUSupporter 8964民主女神 地下教會, Namaste, JMP, Claude LeiboviciJan 12 '18 at 8:11
This question appears to be off-topic. The users who voted to close gave this specific reason:
• "This question is missing context or other details: Please improve the question by providing additional context, which ideally includes your thoughts on the problem and any attempts you have made to solve it. This information helps others identify where you have difficulties and helps them write answers appropriate to your experience level." – Chappers, GNUSupporter 8964民主女神 地下教會, Namaste, JMP, Claude Leibovici
If this question can be reworded to fit the rules in the help center, please edit the question.
• Welcome to math.SE! Please consider taking the time to read the faq to familiarise yourself with some of our common practices. In addition, this page should give you a start at learning how to typeset mathematics here so that your posts say what you want them to, and also look good. As this question appears to be homework, please consider reading this page for information about asking effective homework-related questions. Cheers! – GNUSupporter 8964民主女神 地下教會 Jan 11 '18 at 23:22
## 1 Answer
Hints.
(a) The exponential distribution with rate $\lambda$ has an expected value of $1/\lambda$.
(b) Since $X$ and $Y$ are independent, if they have PDFs $f_X(x)$ and $f_Y(y)$ respectively, then their joint distribution has PDF
$$f_{X, Y}(x, y) = \frac{f_X(x) f_Y(y)}{\int_{x=0}^\infty \int_{y=0}^5 f_X(x) f_Y(y) \, dy \, dx}$$
That is, the joint PDF is the product of the individual PDFs, normalized appropriately. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7542983889579773, "perplexity": 734.9472280426598}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-43/segments/1570986682037.37/warc/CC-MAIN-20191018104351-20191018131851-00283.warc.gz"} |
http://www.math.gatech.edu/seminars-and-colloquia-by-series?series_tid=27&page=1 | ## Seminars and Colloquia by Series
Friday, January 19, 2018 - 13:05 , Location: Skiles 005 , , CS, Georgia Tech , , Organizer: He Guo
Studying random samples drawn from large, complex sets is one way to begin to learn about typical properties and behaviors. However, it is important that the samples examined are random enough: studying samples that are unexpectedly correlated or drawn from the wrong distribution can produce misleading conclusions. Sampling processes using Markov chains have been utilized in physics, chemistry, and computer science, among other fields, but they are often applied without careful analysis of their reliability. Making sure widely-used sampling processes produce reliably representative samples is a main focus of my research, and in this talk I'll touch on two specific applications from statistical physics and combinatorics.I'll also discuss work applying these same Markov chain processes used for sampling in a novel way to address research questions in programmable matter and swarm robotics, where a main goal is to understand how simple computational elements can accomplish complicated system-level goals. In a constrained setting, we've answered this question by showing that groups of abstract particles executing our simple processes (which are derived from Markov chains) can provably accomplish remarkable global objectives. In the long run, one goal is to understand the minimum computational abilities elements need in order to exhibit complex global behavior, with an eye towards developing systems where individual components are as simple as possible.This talk includes joint work with Marta Andrés Arroyo, Joshua J. Daymude, Daniel I. Goldman, David A. Levin, Shengkai Li, Dana Randall, Andréa Richa, William Savoie, Alexandre Stauffer, and Ross Warkentin.
Friday, January 19, 2018 - 13:05 , Location: Skiles 005 , , CS, Georgia Tech , , Organizer: He Guo
Studying random samples drawn from large, complex sets is one way to begin to learn about typical properties and behaviors. However, it is important that the samples examined are random enough: studying samples that are unexpectedly correlated or drawn from the wrong distribution can produce misleading conclusions. Sampling processes using Markov chains have been utilized in physics, chemistry, and computer science, among other fields, but they are often applied without careful analysis of their reliability. Making sure widely-used sampling processes produce reliably representative samples is a main focus of my research, and in this talk I'll touch on two specific applications from statistical physics and combinatorics.I'll also discuss work applying these same Markov chain processes used for sampling in a novel way to address research questions in programmable matter and swarm robotics, where a main goal is to understand how simple computational elements can accomplish complicated system-level goals. In a constrained setting, we've answered this question by showing that groups of abstract particles executing our simple processes (which are derived from Markov chains) can provably accomplish remarkable global objectives. In the long run, one goal is to understand the minimum computational abilities elements need in order to exhibit complex global behavior, with an eye towards developing systems where individual components are as simple as possible.This talk includes joint work with Marta Andrés Arroyo, Joshua J. Daymude, Daniel I. Goldman, David A. Levin, Shengkai Li, Dana Randall, Andréa Richa, William Savoie, Alexandre Stauffer, and Ross Warkentin.
Friday, January 19, 2018 - 13:05 , Location: Skiles 005 , , CS, Georgia Tech , , Organizer: He Guo
Studying random samples drawn from large, complex sets is one way to begin to learn about typical properties and behaviors. However, it is important that the samples examined are random enough: studying samples that are unexpectedly correlated or drawn from the wrong distribution can produce misleading conclusions. Sampling processes using Markov chains have been utilized in physics, chemistry, and computer science, among other fields, but they are often applied without careful analysis of their reliability. Making sure widely-used sampling processes produce reliably representative samples is a main focus of my research, and in this talk I'll touch on two specific applications from statistical physics and combinatorics.I'll also discuss work applying these same Markov chain processes used for sampling in a novel way to address research questions in programmable matter and swarm robotics, where a main goal is to understand how simple computational elements can accomplish complicated system-level goals. In a constrained setting, we've answered this question by showing that groups of abstract particles executing our simple processes (which are derived from Markov chains) can provably accomplish remarkable global objectives. In the long run, one goal is to understand the minimum computational abilities elements need in order to exhibit complex global behavior, with an eye towards developing systems where individual components are as simple as possible.This talk includes joint work with Marta Andrés Arroyo, Joshua J. Daymude, Daniel I. Goldman, David A. Levin, Shengkai Li, Dana Randall, Andréa Richa, William Savoie, Alexandre Stauffer, and Ross Warkentin.
Friday, October 13, 2017 - 13:05 , Location: Skiles 005 , , CS, Georgia Tech , , Organizer: He Guo
We show variants of spectral sparsification routines can preserve thetotal spanning tree counts of graphs, which by Kirchhoff's matrix-treetheorem, is equivalent to determinant of a graph Laplacian minor, orequivalently, of any SDDM matrix. Our analyses utilizes thiscombinatorial connection to bridge between statistical leverage scores/ effective resistances and the analysis of random graphs by [Janson,Combinatorics, Probability and Computing 94]. This leads to a routinethat in quadratic time, sparsifies a graph down to about $n^{1.5}$edges in ways that preserve both the determinant and the distributionof spanning trees (provided the sparsified graph is viewed as a randomobject). Extending this algorithm to work with Schur complements andapproximate Choleksy factorizations leads to algorithms for countingand sampling spanning trees which are nearly optimal for dense graphs.We give an algorithm that computes a $(1\pm \delta)$ approximation tothe determinant of any SDDM matrix with constant probability in about$n^2\delta^{−2}$ time. This is the first routine for graphs thatoutperforms general-purpose routines for computing determinants ofarbitrary matrices. We also give an algorithm that generates in about$n^2\delta^{−2}$ time a spanning tree of a weighted undirected graphfrom a distribution with total variation distance of $\delta$ fromthe w-uniform distribution.This is joint work with John Peebles, Richard Peng and Anup B. Rao.
Friday, October 6, 2017 - 13:05 , Location: Skiles 005 , Josh Daymude , Arizona State University/GaTech theory lab , , Organizer: He Guo
In a self-organizing particle system, an abstraction of programmable matter, simple computational elements called particles with limited memory and communication self-organize to solve system-wide problems of movement, coordination, and configuration. In this paper, we consider stochastic, distributed, local, asynchronous algorithms for 'shortcut bridging', in which particles self-assemble bridges over gaps that simultaneously balance minimizing the length and cost of the bridge. Army ants of the genus Eticon have been observed exhibiting a similar behavior in their foraging trails, dynamically adjusting their bridges to satisfy an efficiency tradeoff using local interactions. Using techniques from Markov chain analysis, we rigorously analyze our algorithm, show it achieves a near-optimal balance between the competing factors of path length and bridge cost, and prove that it exhibits a dependence on the angle of the gap being 'shortcut' similar to that of the ant bridges. We also present simulation results that qualitatively compare our algorithm with the army ant bridging behavior. Our work presents a plausible explanation of how convergence to globally optimal configurations can be achieved via local interactions by simple organisms (e.g., ants) with some limited computational power and access to random bits. The proposed algorithm demonstrates the robustness of the stochastic approach to algorithms for programmable matter, as it is a surprisingly simple extension of a stochastic algorithm for compression. This is joint work between myself/my professor Andrea Richa at ASU and Sarah Cannon and Prof. Dana Randall here at GaTech.
Friday, September 29, 2017 - 13:05 , Location: Skiles 005 , , School of Mathematics, Georgia Tech , , Organizer: He Guo
In 1995 Kim famously proved the Ramsey bound $R(3,t) \ge c t^2/\log t$ by constructing an $n$-vertex graph that is triangle-free and has independence number at most $C \sqrt{n \log n}$. We extend this celebrated result, which is best possible up to the value of the constants, by approximately decomposing the complete graph $K_n$ into a packing of such nearly optimal Ramsey $R(3,t)$ graphs. More precisely, for any $\epsilon>0$ we find an edge-disjoint collection $(G_i)_i$ of $n$-vertex graphs $G_i \subseteq K_n$ such that (a) each $G_i$ is triangle-free and has independence number at most $C_\epsilon \sqrt{n \log n}$, and (b) the union of all the $G_i$ contains at least $(1-\epsilon)\binom{n}{2}$ edges. Our algorithmic proof proceeds by sequentially choosing the graphs $G_i$ via a semi-random (i.e., Rödl nibble type) variation of the triangle-free process. As an application, we prove a conjecture in Ramsey theory by Fox, Grinshpun, Liebenau, Person, and Szabó (concerning a Ramsey-type parameter introduced by Burr, Erdös, Lovász in 1976). Namely, denoting by $s_r(H)$ the smallest minimum degree of $r$-Ramsey minimal graphs for $H$, we close the existing logarithmic gap for $H=K_3$ and establish that $s_r(K_3) = \Theta(r^2 \log r)$. Based on joint work with Lutz Warnke.
Friday, September 15, 2017 - 13:05 , Location: Skiles 005 , Peng Zhang , Computer Science, Georgia Tech , , Organizer: He Guo
In this talk, we study solvers for geometrically embedded graph structured block linear systems. The general form of such systems, PSD-Graph-Structured Block Matrices (PGSBM), arise in scientific computing, linear elasticity, the inner loop of interior point algorithms for linear programming, and can be viewed as extensions of graph Laplacians into multiple labels at each graph vertex. Linear elasticity problems, more commonly referred to as trusses, describe forces on a geometrically embedded object.We present an asymptotically faster algorithm for solving linear systems in well-shaped 3-D trusses. Our algorithm utilizes the geometric structures to combine nested dissection and support theory, which are both well studied techniques for solving linear systems. We decompose a well-shaped 3-D truss into balanced regions with small boundaries, run Gaussian elimination to eliminate the interior vertices, and then solve the remaining linear system by preconditioning with the boundaries.On the other hand, we prove that the geometric structures are necessary` for designing fast solvers. Specifically, solving linear systems in general trusses is as hard as solving general linear systems over the real. Furthermore, we give some other PGSBM linear systems for which fast solvers imply fast solvers for general linear systems.Based on the joint works with Robert Schwieterman and Rasmus Kyng.
Friday, April 28, 2017 - 13:05 , Location: Skiles 005 , Megan Bernstein , School of Mathematics, Georgia Tech , Organizer: Marcel Celaya
The random to random shuffle on a deck of cards is given by at each step choosing a random card from the deck, removing it, and replacing it in a random location. We show an upper bound for the total variation mixing time of the walk of 3/4n log(n) +cn steps. Together with matching lower bound of Subag (2013), this shows the walk mixes with cutoff at 3/4n log(n) steps, answering a conjecture of Diaconis. We use the diagonalization of the walk by Dieker and Saliola (2015), which relates the eigenvalues to Young tableaux. Joint work with Evita Nestorid.
Friday, April 21, 2017 - 13:05 , Location: Skiles 005 , Samantha Petti , School of Mathematics, Georgia Tech , Organizer: Marcel Celaya
Beginning with Szemerédi’s regularity lemma, the theory of graph decomposition and graph limits has greatly increased our understanding of large dense graphs and provided a framework for graph approximation. Unfortunately, much of this work does not meaningfully extend to non-dense graphs. We present preliminary work towards our goal of creating tools for approximating graphs of intermediate degree (average degree o(n) and not bounded). We give a new random graph model that produces a graph of desired size and density that approximates the number of small closed walks of a given sparse graph (i.e., small moments of its eigenspectrum). We show how our model can be applied to approximate the hypercube graph. This is joint work with Santosh Vempala.
Friday, April 14, 2017 - 13:05 , Location: Skiles 005 , Lutz Warnke , Georgia Institute of Technology , Organizer: Marcel Celaya
The concentration of measure phenomenon is of great importance in probabilistic combinatorics and theoretical computer science. For example, in the theory of random graphs, we are often interested in showing that certain random variables are concentrated around their expected values. In this talk we consider a variation of this theme, where we are interested in proving that certain random variables remain concentrated around their expected trajectories as an underlying random process (or random algorithm) evolves. In particular, we shall give a gentle introduction to the differential equation method popularized by Wormald, which allows for proving such dynamic concentration results. This method systematically relates the evolution of a given random process with an associated system of differential equations, and the basic idea is that the solution of the differential equations can be used to approximate the dynamics of the random process. If time permits, we shall also sketch a new simple proof of Wormalds method. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.859319806098938, "perplexity": 1302.7652191630584}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-34/segments/1534221209755.32/warc/CC-MAIN-20180815004637-20180815024637-00406.warc.gz"} |
https://physics.stackexchange.com/questions/102486/how-can-i-destroy-earth-with-physics?noredirect=1 | # How can I destroy earth with physics? [closed]
I want to destroy the whole earth using physics, I would like to learn some of the ways that can be used to achieve this. I tried using a nuclear bomb but it takes so long, and I can't wait that much: Why does it take so long to make a nuclear bomb?
What are some physics experiments and theories to help me destroy the earth? Note that I have all the money and privileges I need.
• Send a space crew to divert an asteroid onto the earth. – Isopycnal Oscillation Mar 7 '14 at 20:00
• I don't think you need physics to do this. Politics is doing it just fine. – jerk_dadt Mar 7 '14 at 20:24
• You'll need a Death Star – Kyle Kanos Mar 7 '14 at 20:29
• If you can't wait that much maybe you don't have the willpower to destroy earth anyway – Claudiordgz Mar 7 '14 at 22:42
• Last December, I received a text message from the USGS which said there had been an earthquake near Polson, Montana with a magnitude of 22.0. My first thought was that the Solar System would have a new asteroid belt, but my calculations indicated that there probably wouldn't be enough left to form one; the energy released would be about 250,000 times Earth's gravitational binding energy, more than enough to vaporize the planet. Unfortunately for your evil schemes, a followup message revised the magnitude to 2.2. – Keith Thompson Mar 8 '14 at 2:41
## 1 Answer
Earth's gravitational binding energy is $-1.711×10^{32}~\mathrm{J}$ or $4.09×10^{13}$ gigatons. The Tsar Bomba massed $27$ tonnes to deliver $0.057$ gigatons. Do the math for Earth disassembly by bomb. Substituting depleted uranium for the used lead tamper will double the yield.
Earth orbital speed averages 30 km/s and it masses $5.97×10^{24}~\mathrm{kg}$, so $mv^2 / 2 = 2.7×10^{33}~\mathrm{J}$. Rather than going for a messy asteroid impact and endangering Venusian hortas with debris infall, drop the Earth into the Sun, $t = 64.56$ days.
Patience. The Earth's rotational energy is about $2.13 \times 10^{29}~\mathrm{J}$ (non-homogeneous sphere). You'll need obtain the orbital stopper energy elsewhere.
The fast path is simply to drop a strangelet. The Earth will condense into "an inert hyperdense sphere about one hundred meters across." | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8236883878707886, "perplexity": 1449.367040538298}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-10/segments/1581875141460.64/warc/CC-MAIN-20200217000519-20200217030519-00534.warc.gz"} |
http://tex.stackexchange.com/questions/84255/table-frames-beyond-simple-lines/84262 | # Table Frames beyond simple lines
Is there a possibility to create frames for tabulars, that go beyond a simple line?
\begin{tabular}{|l|l|}
\hline
A & B\\
\hline
C & D\\
\hline
\end{tabular}
creates lines as a "frame", but these are indistinguishable from the lines that separate the rows and columns. I would like to have, for example thick lines for the frame. Or double lines that look good and not like the one I create like this
\begin{tabular}{||l|l||}
\hline \hline
A & B\\
\hline
C & D\\
\hline \hline
\end{tabular}
Any ideas?
-
Perhaps tikz can help here
Of course, because it's tikz, you can get much more adventurous with your affects if you want to.
\documentclass{article}
\usepackage{tikz}
\begin{document}
\tikz\node[draw=red,thick,double,inner sep=1pt]{
\begin{tabular}{l|l}
A & B\\
\hline
C & D\\
\end{tabular}};
\end{document}
If you'd like to apply the idea to every tabular, then you could use the etoolbox, perhaps something like the following- note the gradient shading :)
\documentclass{article}
\usepackage{tikz}
\usepackage{etoolbox}
\BeforeBeginEnvironment{tabular}{\tikzpicture\node[draw=red,thick,double,inner sep=1pt,top color=blue,bottom color=yellow]\bgroup}
\AfterEndEnvironment{tabular}{\egroup;\endtikzpicture}
\begin{document}
\begin{tabular}{l|l}
A & B\\
\hline
C & D\\
\end{tabular}
\end{document}
Perhaps you'd like rounded corners
\BeforeBeginEnvironment{tabular}{\tikzpicture\node[rounded corners=3pt,draw=red,thick,double,inner sep=1pt,top color=blue,bottom color=yellow]\bgroup}
You could even go completely crazy and surround the tabular in a circle or a star, but I'll leave that up to you :)
The possibilities are limited only by imagination- have fun, and check out the manual for more ideas and options.
-
Thanks, I got some nice frames from your examples. Although I dont think, that I need color at all in my tables! ;) – Haatschii Nov 26 '12 at 3:07
@Haatschii you're very welcome :) glad it helped! – cmhughes Nov 26 '12 at 3:14
With inner sep=.3pt+\pgflinewidth, .3pt being the half of double distance (initially .6pt), the outer lines just touch tabular's lines instead of drawing over them. – Qrrbrbirlbel Nov 26 '12 at 3:30
You could be interested in the features provided by the tabu package: a simple example:
\documentclass{article}
\usepackage{xcolor}
\usepackage{tabu}
\begin{document}
{\arrayrulewidth=3pt
\begin {tabu}{|[5pt cyan!60!black]c|[5pt red!60!black] c|[5pt cyan!60!black]}
\taburulecolor{orange}
\hline
A & B \\
\hline
C & D \\
\hline
\end {tabu}
}
\end{document}
-
Not everything that can be done, should be done. – Aditya Nov 26 '12 at 2:09
@Aditya wise words, indeed! – Gonzalo Medina Nov 26 '12 at 2:14
I think this will work as well, maybe even more elegant. But I just completed it using cmhughes approach. Thanks nevertheless! – Haatschii Nov 26 '12 at 3:05
Besides the TikZ solution where you can create very interesting tables, there is the hhline package which is suited for just tables.
## Code
\documentclass{article}
\usepackage{hhline}
\begin{document}
\begin{tabular}{||l|l||}
\hhline{#==#}
A & B \\ \hhline{|--|}
C & D \\ \hhline{#==#}
\end{tabular}
\begin{tabular}{||l|l||}
\hhline{|t:==:t|}
A & B \\ \hhline{||--||}
C & D \\ \hhline{|b:==:b|}
\end{tabular}
\end{document}
## Output
-
Have a look at the booktabs package on some guidelines for creating good looking tables. In general, it is not a good idea to use vertical lines in tables. The booktabs package also provides \toprule, \midrule and \bottomrule commands for rules of different thickness.
\documentclass[margin=3mm]{standalone}
\usepackage{booktabs}
\begin{document}
\begin{tabular}{ll}
\toprule
A & B \\
\midrule
C & D \\
E & F \\
\bottomrule
\end{tabular}
\end{document}
-
I know booktabs and use it most of the time. However in this case I am creating some kind of form sheet, that has to be filled out in printed form by other people. So I really want the vertical lines to make clear where to write. I don't think booktabs helps here. – Haatschii Nov 26 '12 at 3:00 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9604061841964722, "perplexity": 2488.743876315355}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398445080.12/warc/CC-MAIN-20151124205405-00119-ip-10-71-132-137.ec2.internal.warc.gz"} |
http://math.stackexchange.com/users/19209/matt?tab=activity | # matt
less info
reputation
717
bio website bbp.carma.newcastle.edu.au location Newcastle, Australia age member for 3 years, 2 months seen Jan 29 at 2:06 profile views 162
did someone say coffee?
# 418 Actions
Nov10 awarded Yearling Nov7 revised A challenging calculus question about differentiation formatting Nov7 suggested approved edit on A challenging calculus question about differentiation Sep30 awarded Explainer Sep24 awarded Autobiographer Nov10 awarded Yearling Nov4 revised average of a bounded convex set tex formatting Nov4 suggested approved edit on average of a bounded convex set Oct12 suggested rejected edit on How to minimize such an energy? Oct12 revised How to find the inverse of a piecewise function latex formatting Oct12 suggested approved edit on How to find the inverse of a piecewise function Oct11 revised integrate a variable 'u' with a 'dx', is that possible? (Basic Integrals) latex formatting Oct11 suggested approved edit on integrate a variable 'u' with a 'dx', is that possible? (Basic Integrals) Aug7 revised Mapping complex analysis help? latex formatting Aug7 suggested approved edit on Mapping complex analysis help? Jun16 awarded Self-Learner Feb16 answered How to compute the norm of this particular bounded linear functional? Feb16 answered Bounded linear function implication Feb8 answered Proving a certain inequality in $\mathbb{R}^n$ Nov22 revised Invariant factors of $\mathbb Z_m\times\mathbb Z_n$ tex formatting | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9779325723648071, "perplexity": 12988.614802481796}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-06/segments/1422122245449.81/warc/CC-MAIN-20150124175725-00139-ip-10-180-212-252.ec2.internal.warc.gz"} |
https://zenodo.org/record/1123246/export/xd | Journal article Open Access
# Dietary exposure to mycotoxins through the consumption of commercial bread loaf in Valencia, Spain
### Dublin Core Export
<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
<dc:date>2016-10-13</dc:date>
<dc:description>In this study, 80 commercial samples of bread loaves were purchased from different supermarkets located in Valencia (Spain). These samples were investigated for the presence of legislated and non-legislated mycotoxins. Results showed that samples were contaminated with Aflatoxins (AFs), Zearalenone (ZEA) and Enniatins (ENs) with a frequency of 20, 96, and 65% respectively. Aflatoxin B1 (AFB1), Aflatoxin B2 (AFB2) and Aflatoxin G1 (AFG1) were detected with concentrations ranged from 0.5 to 7.1 μg/kg. The samples contaminated with AFB1 showed values exceeding the maximum limit allowed in the EU. The sum of AFs also exceeded the maximum limit allowed in 6 samples. ENs contamination data ranged from 0.2 to 54 μg/kg and ENB was the most prevalent one. ZEA values ranged from 27 to 905 μg/kg and 30% of the contaminated samples were above the limits enforced by the EU. Finally, dietary exposure of the population living in Valencia to AFs, ENs and ZEA was estimated using the deterministic approach, through the evaluation of the consumption of commercial loaf bread and relating this data with the contamination of the loaf bread, for the calculation of the estimated daily intake (EDI) for each mycotoxin detected.</dc:description>
<dc:identifier>https://zenodo.org/record/1123246</dc:identifier>
<dc:identifier>10.1016/j.lwt.2016.10.029</dc:identifier>
<dc:identifier>oai:zenodo.org:1123246</dc:identifier>
<dc:relation>info:eu-repo/grantAgreement/EC/H2020/678781/</dc:relation>
<dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
<dc:subject>Mycotoxins LC-MS/MS Loaf bread Risk assessment Estimated daily intake</dc:subject>
<dc:title>Dietary exposure to mycotoxins through the consumption of commercial bread loaf in Valencia, Spain</dc:title>
<dc:type>info:eu-repo/semantics/article</dc:type>
<dc:type>publication-article</dc:type>
</oai_dc:dc>
43
36
views | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6384058594703674, "perplexity": 13355.752045657004}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585370506959.34/warc/CC-MAIN-20200402111815-20200402141815-00143.warc.gz"} |
http://mathhelpforum.com/calculus/67673-integration-problem-print.html | Integration problem?
• January 11th 2009, 05:55 AM
dillonmhudson
Integration problem?
How in the world do you solve this???:
int[sec(1-x)*tan(1-x)*dx]
Thank you!
• January 11th 2009, 06:00 AM
nikhil
Try it
Hint
int(sec(x)tan(x))dx=sec(x)+c
• January 11th 2009, 06:05 AM
dillonmhudson
Ok,
so using u-substitution:
u = sec(1-x)
du = sec(1-x)*tan(1-x)?
Thanks!
• January 11th 2009, 06:33 AM
Prove It
Quote:
Originally Posted by dillonmhudson
How in the world do you solve this???:
int[sec(1-x)*tan(1-x)*dx]
Thank you!
Remember that $\sec{(1 - x)} = \frac{1}{\cos{(1 - x)}}$ and that $\tan{(1 - x)} = \frac{\sin{(1-x)}}{\cos{(1 -x)}}$.
Using these, we see that
$\int{\sec{(1-x)}\,\tan{(1-x)}\,dx} = \int{\frac{1}{\cos^2{(1-x)}}\,\sin{(1-x)}\,dx}$.
Use the substitution $u = \cos{(1-x)}$ so that $\frac{du}{dx} = \sin{(1-x)}$. Then the integral becomes
$\int{\frac{1}{u^2}\,\frac{du}{dx}\,dx}$
$= \int{u^{-2}\,du}$
$= -u^{-1} + C$
$= -\frac{1}{\cos{(1-x)}} + C$
$= -\sec{(1-x)} + C$.
• January 11th 2009, 06:36 AM
dillonmhudson
Awesome!
Thank you both very much! | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 10, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8689636588096619, "perplexity": 8178.461294808163}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-35/segments/1440645258858.62/warc/CC-MAIN-20150827031418-00103-ip-10-171-96-226.ec2.internal.warc.gz"} |
https://www.electro-tech-online.com/threads/voltage-booster-schmatic.97100/ | # Voltage booster schmatic
Status
Not open for further replies.
#### sfink06
##### New Member
Hi all,
I am having trouble getting this circuit to work correctly. The output of the voltage booster does not stay as high as it should be. Someone here told me that they think the voltage booster and pic power lines need to be separated, but I haven't tested this idea yet. Is there some problem with the way it is drawn?
Thanks.
#### Attachments
• 83.7 KB Views: 192
#### Electronworks
##### New Member
Ok, without the chip numbers, it is difficult to work out if your circuit is correct or not. I am assuming the component between P$1 and P$2 is an inductor.
Also if CO is your output capacitor, it looks a little small. I would make it 100uF and see what happens then.
Do you have a reference circuit to work from in the datasheet?
Also your feedback resistors are rather high. Unless you are running this circuit off a lemon, bring them down by a factor of 10 for better stability.
I also don't think you need RF3. This will only slow down your response time
Let me know
#### sfink06
##### New Member
The voltage booster is TPS61081 from TI.
#### blueroomelectronics
##### Well-Known Member
What's your voltage / current in and what do you want out?
#### sfink06
##### New Member
okay, the PWR signal here is a 3V battery, so I expect 20V out. The output is then fed into these transistors here. I actually need 120 mA (I think thats right...) out of the transistors. I have tested the voltage booster and it works fine by itself, but when I connect it in this circuit with the PIC running It doesn't put out 20V like it should. My friend suggests that the PIC clear pin may be falling low, but that doesn't sound right to me.
#### Attachments
• 47.4 KB Views: 90
#### blueroomelectronics
##### Well-Known Member
What sort of 3v battery? A coin cell?
#### sfink06
##### New Member
I think this is the model... its from Full River LP30 FR Bahoma 3.3V 30mAh
#### blueroomelectronics
##### Well-Known Member
Ok That battery puts out 600mA max, and you need more than 800mA and with the inefficiencies of the inverter closer to 1A or more. You need a bigger battery.
Are you running a motor or stepper? It'll probably need much more current to start than run.
#### blueroomelectronics
##### Well-Known Member
Just looked at your datasheet, that's a simple white LED driver is that what your driving?
It's probably a pulsed output.
#### sfink06
##### New Member
actually the transistors are running electro-thermal actuators.
#### sfink06
##### New Member
and yes it is a pulsed output
Status
Not open for further replies.
Replies
2
Views
3K
Replies
12
Views
8K
Replies
5
Views
1K
Replies
0
Views
1K
Replies
1
Views
810
Loading | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.34735238552093506, "perplexity": 3317.5336434762125}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-50/segments/1606141195069.35/warc/CC-MAIN-20201128040731-20201128070731-00460.warc.gz"} |
http://www.wias-berlin.de/publications/wias-publ/run.jsp?template=abstract&type=Preprint&year=2005&number=1027 | WIAS Preprint No. 1027, (2005)
# Macroscopic behavior of microscopic oscillations in harmonic lattices via Wigner--Husimi transforms
Authors
• Mielke, Alexander
ORCID: 0000-0002-4583-3888
2010 Mathematics Subject Classification
• 37K60 70F45 74Q10 74A25
Keywords
• Harmonic lattice, discrete microscopic systems, macroscopic continuum limit, Gamma-limit, Wigner measure, Husimi transform
DOI
10.20347/WIAS.PREPRINT.1027
Abstract
We consider the dynamics of infinite harmonic lattices in the limit of the lattice distance epsilon tending to 0. We allow for general polyatomic crystals but assume exact periodicity such that the system can be solved in principle by Fourier transform and linear algebra. Our aim is to derive macroscopic continuum limit equations for epsilon --> 0. For the weak limit of displacements and velocities we find the equation of linear elastodynamics, where the elasticity tensor is obtained as a Gamma-limit. The weak limit of the local energy density can be described by generalizations of the Wigner-Husimi measure which satisfies a transport equation on the product of physical space and Fourier space. The concepts are illustrated via several examples and via a comparison to Whitham's modulation equation.
Appeared in
• Arch. Ration. Mech. Anal., 181 (2006) pp. 401--448. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9834853410720825, "perplexity": 1477.6913333779553}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-24/segments/1590347394756.31/warc/CC-MAIN-20200527141855-20200527171855-00116.warc.gz"} |
https://www.ideals.illinois.edu/handle/2142/72365 | ## Files in this item
FilesDescriptionFormat
application/pdf
9503183.pdf (7MB)
(no description provided)PDF
## Description
Title: In Vitro and in Vivo Studies of the Recognition of Double-Strand DNA by EcoRI and RsrI Endonucleases Author(s): Fisher, Eric William Doctoral Committee Chair(s): Gumport, Richard I. Department / Program: Biochemistry Discipline: Biochemistry Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Biology, Genetics Biology, Microbiology Chemistry, Biochemistry Abstract: EcoRI and RsrI endonucleases present rare opportunities to study the mechanisms by which site-specific DNA-binding proteins identify their substrate sequences among an overwhelming number of other sequences to which they also show significant affinity. These proteins have advantages as subjects for the study of protein/DNA recognition in that they are enzymes, permitting the examination of both binding and catalysis. The fact that both enzymes recognize the same sequence and catalyze the same reaction, although they share only 50% amino acid identity and differ physically and chemically, suggests that comparing their recognition properties will be informative with respect to structure/function relationships and to protein evolution. Finally, the effort already expended in characterizing the enzymes leaves them among the best understood of enzymes recognizing specific DNA sequences.Cleavage by EcoRI endonuclease under conditions reducing specificity was examined using steady-state kinetics to determine the hierarchy of preference among sequences other than the canonical, GAATTC. The enzyme suffered a loss of catalytic activity too rapid to permit accurate measurement of kinetic constants (the Michaelis constant, K$\sb{\rm M}$, and the turnover number, k$\sb{\rm cat}$) governing the reaction under the buffer conditions used, and this problem persisted in a variety of different buffers.Because the association constants governing specific and nonspecific binding to large DNA molecules by EcoRI endonuclease in the absence of magnesium ion had been determined, these same values were measured for RsrI. In spite of differing buffer requirements for the two enzymes, RsrI requiring a lower incubation temperature and lower ionic strength, both enzymes show an affinity of approximately 10$\sp$ M$\sp{-1}$ for the GAATTC site in plasmid pBR322, and an average affinity of less than 10$\sp6$ M$\sp{-1}$ for other sequences in the plasmid. When the temperature of RsrI incubation is reduced from 20$\sp\circ$C to 0$\sp\circ$C the specific affinity of RsrI for pBR322 falls and the nonspecific affinity rises slightly. These changes result in a net three-fold decrease in binding selectivity of the enzyme for the specific site over the nonspecific through this temperature range.To begin the task of altering the specificity of EcoRI endonuclease to recognize sequences other than GAATTC, the bacteriophage P22 challenge-phage assay was adapted for use with both EcoRI and RsrI endonucleases. The gene encoding a mutant of EcoRI (E111Q) lacking catalytic activity but retaining binding specificity was mutagenized randomly by several methods, and a mutant was selected with a binding preference for the EcoRI-methylated GAATTC (GA$\sp{\rm m}$ATTC) sequence over the unmethylated sequence. This mutant, isolated after one round of hydroxylamine treatment of cells carrying the ecoRIR(E111Q) gene, possesses binding specificity opposite to wild-type EcoRI endonuclease for methylated and unmethylated GAATTC: wild-type binds tightly to the unmethylated site and several orders of magnitude less to the methylated site, but this mutant appears to bind tightly to the methylated site and almost undetectably to the unmethylated. This mutant will now be examined in vitro with respect to its binding properties, and then sequenced to determine the amino acid change, to rationalize the role of the mutation in conferring a reversal of specificity within the context of the crystallographic model now available for the specific EcoRI endonuclease/DNA complex. (Abstract shortened by UMI.) Issue Date: 1994 Type: Text Description: 164 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1994. URI: http://hdl.handle.net/2142/72365 Other Identifier(s): (UMI)AAI9503183 Date Available in IDEALS: 2014-12-17 Date Deposited: 1994
| {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6871779561042786, "perplexity": 9805.232654655378}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560281574.78/warc/CC-MAIN-20170116095121-00525-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://python-textbook.pythonhumanities.com/05_streamlit/05_02_03_layout_design.html | 2.2. Layout Design#
Controlling the layout of an application is essential from both an aesthetic and programmatic perspective. In Streamlit, we have a number of ways to control our app’s layout. Streamlit offers six different ways of controling the layout of your application through widgets. Further customization is also possible by controling the page configuration of your application as well as custom HTML. Here, we will focus on the first two; we will treat custom HTML later in this chapter.
2.2.1. Layout Widgets#
2.2.1.2. Columns#
We can also control the horizontal layout of our application with Streamlit’s st.columns() widget. This will take a single mandatory argument, an integer that corresponds to the number of columns you wish to create. This will return a list of column widgets that you can write to. As with the sidebar, to write to the column widget, you will use its variable name proceeded by .[widget (write, header, etc.)]
st.header("Columns")
cols = st.columns(2)
cols[0].write("Column 1")
cols[1].write("Column 2")
The output will look like this:
2.2.1.3. Expander#
In some cases, we will want to allow a user to view a large amount of data, but this will detract from the application and put some of the main features very low on the main page of the app. In these, cases we want a user to be able to expand certain aspects of the application when they wish and compress them when they are finished using them. Streamlit comes built with this feature in the st.expander() widget.
Once we create an expander in our application, we can then insert any other Streamlit we wish inside of it, just like columns and the sidebar. In the code below, we are creating a simple expander and then writing into it.
expander = st.expander("This is an Expander")
expander.write("This is some text in an expander...")
The output will look like this:
Notice how we see a new widget on our page. In the top-right corner, you can press the carrot and the expander will reveal the contents.
2.2.1.4. Container#
We also have the ability to create containers in our application with the st.container() widget. Remember, Streamlit widgets are populated in the order that Streamlit reads your Python file. This means that if your user performs an action and you want to display that data later in your file, then that data will populate at the bottom of your application. This is not ideal. In these scenarios, you need a way to populate a result higher in your application’s page. You can do this with the container. The container will sit in that precise position and it can then be populated at a later time.
st.header("Container")
container = st.container()
container.write("This is some text inside a container...")
The output will look like this:
2.2.1.5. Tabs#
In Streamlit, we can also make tabs so that a single page can host several different pages within it. This is useful if you are working with multiple datasets or collections of items that need to be displayed individually, but there is not enough space in your app to display all data sequentially. We create tabs in Streamlit via the st.tabs() widget. This will take a single argument which will be a list of tab names.
In the sample code below, we create the tabs on line 1 and then iterate over them to populate each tab with a unique message via st.write().
tabs = st.tabs(["Tab 1", "Tab 2"])
for i, tab in enumerate(tabs):
tabs[i].write(f"Tab {i+1}")
The output will look like this:
2.2.1.6. Empty#
The final layout widget in Streamlit is st.empty(). This takes no arguments. It sits on the page, rather like the st.container() widget, but unlike st.container(), st.empty() will only display the most recent item sent to it. This is useful in rather niche scenarios when you want to display data individually. You can use the following code to iterate over a list of names. Note in the image below that only the last name on the list appears. This is because it was the final item in the list.
st.header("Empty")
empty = st.empty()
items = ["Tom", "Fred", "Stephanie"]
for item in items:
empty.write(item)
The output will look like this: | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.17868337035179138, "perplexity": 1355.4985538247183}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2023-14/segments/1679296945030.59/warc/CC-MAIN-20230323065609-20230323095609-00471.warc.gz"} |
http://goldbook.iupac.org/terms/view/D01620 | desorption
https://doi.org/10.1351/goldbook.D01620
The converse of @A00155@, i.e. the decrease in the amount of adsorbed substance.
Source:
PAC, 1972, 31, 577. (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 584 [Terms] [Paper] | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9329372048377991, "perplexity": 7945.875598609051}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-29/segments/1593655881763.20/warc/CC-MAIN-20200706160424-20200706190424-00578.warc.gz"} |
https://gmatclub.com/forum/if-a-and-b-are-non-zero-integers-and-a-b-1-then-which-of-154718.html | GMAT Question of the Day - Daily to your Mailbox; hard ones only
It is currently 15 Nov 2018, 09:20
# Join Chat Room for Live Updates
### GMAT Club Daily Prep
#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
we will pick new questions that match your level based on your Timer History
Track
every week, we’ll send you an estimated GMAT score based on your performance
Practice
Pays
we will pick new questions that match your level based on your Timer History
## Events & Promotions
###### Events & Promotions in November
PrevNext
SuMoTuWeThFrSa
28293031123
45678910
11121314151617
18192021222324
2526272829301
Open Detailed Calendar
• ### Free GMAT Strategy Webinar
November 17, 2018
November 17, 2018
07:00 AM PST
09:00 AM PST
Nov. 17, 7 AM PST. Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.
• ### GMATbuster's Weekly GMAT Quant Quiz # 9
November 17, 2018
November 17, 2018
09:00 AM PST
11:00 AM PST
Join the Quiz Saturday November 17th, 9 AM PST. The Quiz will last approximately 2 hours. Make sure you are on time or you will be at a disadvantage.
# If a and b are non-zero integers, and a/b > 1, then which of
Author Message
TAGS:
### Hide Tags
Director
Joined: 29 Nov 2012
Posts: 765
If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
Updated on: 21 Jun 2013, 23:34
3
10
00:00
Difficulty:
45% (medium)
Question Stats:
69% (01:54) correct 31% (01:31) wrong based on 452 sessions
### HideShow timer Statistics
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
_________________
Click +1 Kudos if my post helped...
Amazing Free video explanation for all Quant questions from OG 13 and much more http://www.gmatquantum.com/og13th/
GMAT Prep software What if scenarios http://gmatclub.com/forum/gmat-prep-software-analysis-and-what-if-scenarios-146146.html
Originally posted by fozzzy on 21 Jun 2013, 21:26.
Last edited by fozzzy on 21 Jun 2013, 23:34, edited 3 times in total.
Math Expert
Joined: 02 Sep 2009
Posts: 50610
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
22 Jun 2013, 12:43
6
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
If b is positive, then we have that a>b>0.
If b is negative, then we have that a<b<0.
A. a > b. Not necessarily true.
B. 2a > b. Not necessarily true.
C. a^2< b^2 --> |a|<|b|. Not necessarily true.
D. ab > b. If a>b>0, then ab>b (the product of two positive integers is obviously greater than either one of them) and if a<b<0, then ab=positive>negative=b. So, this statement is always true.
E. a^3 < b^3 --> a<b. Not necessarily true.
Hope it's clear.
_________________
##### General Discussion
Manager
Status: Trying.... & desperate for success.
Joined: 17 May 2012
Posts: 63
Location: India
Schools: NUS '15
GPA: 2.92
WE: Analyst (Computer Software)
Re: If a and b are non-zero integers, and , then which of the fo [#permalink]
### Show Tags
21 Jun 2013, 21:55
fozzzy wrote:
If a and b are non-zero integers, and , then which of the following must be true?
$$a>b$$
$$2a>b$$
$$a^2< b^2$$
$$ab> b$$
$$a^3 < b^3$$
A & B are non zero integers then,
a>b .. Assume a = 10 & b = 20. Not true2a>b.. assume a = 10 and b =40
20>40?? Not true.
B^2 > a^2. assume a = 5 and b = 2.
4 > 25?? Not true
ab > b assume a = -3 and b =7
-21>7?? Not true
a^3 < b^3.. assume a = 3 and b = 2
9 < 8??
Not true.
I guess question is not correctly worded or i am making a mistake somewhere.
Director
Joined: 29 Nov 2012
Posts: 765
Re: If a and b are non-zero integers, and , then which of the fo [#permalink]
### Show Tags
21 Jun 2013, 22:12
navigator123 wrote:
fozzzy wrote:
If a and b are non-zero integers, and , then which of the following must be true?
$$a>b$$
$$2a>b$$
$$a^2< b^2$$
$$ab> b$$
$$a^3 < b^3$$
A & B are non zero integers then,
a>b .. Assume a = 10 & b = 20. Not true2a>b.. assume a = 10 and b =40
20>40?? Not true.
B^2 > a^2. assume a = 5 and b = 2.
4 > 25?? Not true
ab > b assume a = -3 and b =7
-21>7?? Not true
a^3 < b^3.. assume a = 3 and b = 2
9 < 8??
Not true.
I guess question is not correctly worded or i am making a mistake somewhere.
Sorry I have updated the question!
_________________
Click +1 Kudos if my post helped...
Amazing Free video explanation for all Quant questions from OG 13 and much more http://www.gmatquantum.com/og13th/
GMAT Prep software What if scenarios http://gmatclub.com/forum/gmat-prep-software-analysis-and-what-if-scenarios-146146.html
Director
Joined: 03 Aug 2012
Posts: 746
Concentration: General Management, General Management
GMAT 1: 630 Q47 V29
GMAT 2: 680 Q50 V32
GPA: 3.7
WE: Information Technology (Investment Banking)
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
25 Jul 2013, 10:55
Bunuel wrote:
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
If b is positive, then we have that a>b>0.
If b is negative, then we have that a<b<0.
A. a > b. Not necessarily true.
B. 2a > b. Not necessarily true.
C. a^2< b^2 --> |a|<|b|. Not necessarily true.
D. ab > b. If a>b>0, then ab>b (the product of two positive integers is obviously greater than either one of them) and if a<b<0, then ab=positive>negative=b. So, this statement is always true.
E. a^3 < b^3 --> a<b. Not necessarily true.
Hope it's clear.
I Aspire to learn even 10% of the approaches you use to solve a math question.
Rgds,
TGC !!
SVP
Joined: 06 Sep 2013
Posts: 1745
Concentration: Finance
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
01 Jan 2014, 06:56
fozzzy wrote:
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
Yeah very good question a bit complicated, maybe I took the long way home but let's see
We get a-b/b > 0
One has to scenarios
1) If a-b>0, then b>0, therefore a>0. So all in all a>b>0
2) If a-b<0, then b<0, therefore a<0. So all in all 0>b>a
Let's check out the answer choices
A. a > b Not always true, could be scenario 2
B. 2a > b Not true at all
C. a^2< b^2 Too many different possibilities
D. ab > b This is equal to b(a-1)>0
Now we have two scenarios as well
If b>0, then a>1. Note that we are told that a.b are integers. Therefore b>0 means that b has to be 1 at least and therefore a>1.
If b<0, then a<-1. Same as above
So it works for both of our scenarios
E. a^3 < b^3 This is the same as to say b>a, which is not always true
Hope it helps
Kudos rain!!! [/quote]
Director
Affiliations: CrackVerbal
Joined: 03 Oct 2013
Posts: 526
Location: India
GMAT 1: 780 Q51 V46
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
02 Jan 2014, 02:14
2
fozzzy wrote:
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
Lets plug in here
a = -3, b = -2
A - Eliminated
B - Eliminated
C - Eliminated
D - True
E - Eliminated
_________________
Intern
Joined: 13 Dec 2013
Posts: 36
GMAT 1: 620 Q42 V33
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
08 Jun 2014, 07:35
If a = 0.5 and b = 0.1
Then a/b = 0.5/0.1 = 5
When I tried to plug in the values into the d) option I got a*b = (0.5)(0.1) = 0.05 which isn't greater than b = 0.1
So option D also wouldn't hold true.
Am I doing something wrong?
Math Expert
Joined: 02 Sep 2009
Posts: 50610
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
08 Jun 2014, 09:24
Enael wrote:
If a = 0.5 and b = 0.1
Then a/b = 0.5/0.1 = 5
When I tried to plug in the values into the d) option I got a*b = (0.5)(0.1) = 0.05 which isn't greater than b = 0.1
So option D also wouldn't hold true.
Am I doing something wrong?
Yes. We are told that a and b are non-zero integers.
_________________
Manager
Joined: 07 Dec 2009
Posts: 94
GMAT Date: 12-03-2014
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
05 Jan 2015, 10:18
I guess the best approach here would be to Plug in values...
Try a=-3 and b = -2
All get eliminated except for D
Intern
Joined: 22 Jan 2017
Posts: 2
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
19 Jun 2017, 18:48
Bunuel wrote:
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
If b is positive, then we have that a>b>0.
If b is negative, then we have that a<b<0.
A. a > b. Not necessarily true.
B. 2a > b. Not necessarily true.
C. a^2< b^2 --> |a|<|b|. Not necessarily true.
D. ab > b. If a>b>0, then ab>b (the product of two positive integers is obviously greater than either one of them) and if a<b<0, then ab=positive>negative=b. So, this statement is always true.
E. a^3 < b^3 --> a<b. Not necessarily true.
Hope it's clear.
Hi Brunel,
I am still confused. I can't see the connection between the question asking : a/b>1 , and the answers below
Could you or anyone kindly explaain this
Thank you
Math Expert
Joined: 02 Sep 2009
Posts: 50610
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
19 Jun 2017, 21:20
whoisjon2 wrote:
Bunuel wrote:
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
If b is positive, then we have that a>b>0.
If b is negative, then we have that a<b<0.
A. a > b. Not necessarily true.
B. 2a > b. Not necessarily true.
C. a^2< b^2 --> |a|<|b|. Not necessarily true.
D. ab > b. If a>b>0, then ab>b (the product of two positive integers is obviously greater than either one of them) and if a<b<0, then ab=positive>negative=b. So, this statement is always true.
E. a^3 < b^3 --> a<b. Not necessarily true.
Hope it's clear.
Hi Brunel,
I am still confused. I can't see the connection between the question asking : a/b>1 , and the answers below
Could you or anyone kindly explaain this
Thank you
The question does not asks whether a/b > 1. It says that a/b > 1. So, the question is: given that a/b > 1, which of the following options must be true?
_________________
Target Test Prep Representative
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2830
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
20 Jun 2017, 18:15
1
fozzzy wrote:
If a and b are non-zero integers, and a/b > 1, then which of the following must be true?
A. a > b
B. 2a > b
C. a^2< b^2
D. ab > b
E. a^3 < b^3
If a/b > 1, then a and b must have the same sign, with |a| > |b|. For example, a = 3 and b = 2 OR a = -3 and b = -2.
Let’s analyze each given answer choice.
A. a > b
Let a = -3 and b = -2; we can see that A is not true.
B. 2a > b
Let a = -3 and b = -2; we can see that B is not true.
C. a^2 < b^2
Let a = 3 and b = 2; we can see that C is not true.
D. ab > b
Let a = 3 and b = 2; we have ab > b. Let a = -3 and b = -2; we have ab > b. We see that D can be true, but let’s also analyze choice E before we conclude that choice D is definitely true.
E. a^3 < b^3
Let a = 3 and b = 2; we can see that E is not true.
_________________
Jeffery Miller
GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions
Senior Manager
Joined: 26 Dec 2015
Posts: 258
Location: United States (CA)
Concentration: Finance, Strategy
WE: Investment Banking (Venture Capital)
Re: If a and b are non-zero integers, and a/b > 1, then which of [#permalink]
### Show Tags
05 Dec 2017, 11:33
my .02:
* MUST BE TRUE questions tend to be D or E. so even if you're running out of time or trying to burn the Q, you have a 50/50 here.
we're told that:
1) a & b = integers AND ARE NOT 0 (aka NO FRACTIONS)
2) $$\frac{a}{b}$$>1
Let's make sense of (2): for a fraction to be GREATER THAN 1, what needs to be true?
a) The numerator must be greater than the denominator
b) The numerator AND denominator must share the same sign (i.e. both must be POSITIVE or NEGATIVE)
KEYS TO THE PROBLEM:
> if b = positive (let's say b=2), then we can say a=4. that way, 2>1.
> if b = negative (let's say b=-2), then we can say a=-4. that way, 2>1.
** Both of these conditions match the above proofs.
** Very helpful to PICK #s to solve
Let's plug in these sets of #s for A/C A->E.
A) a>b --> what if a=-4, b=-2? Incorrect.
B) 2a>b --> what if a=-4, b=-2? Incorrect.
C) $$a^{2}$$<$$b^{2}$$ --> what if a=-4, b=-2? Incorrect.
D) ab>b --> try: a=-4, b=-2. then, 8>-2. or: a=4, b=2. then, 8>2. Correct.
E) $$a^{3}$$<$$b^{3}$$ -->what if a=4, b=2? then 64<8. Incorrect.
Re: If a and b are non-zero integers, and a/b > 1, then which of &nbs [#permalink] 05 Dec 2017, 11:33
Display posts from previous: Sort by | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.7854961156845093, "perplexity": 4005.8850551932637}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-47/segments/1542039742793.19/warc/CC-MAIN-20181115161834-20181115183834-00414.warc.gz"} |
https://powershell.org/forums/topic/how-to-remotely-execute-a-ps-script-that-resides-on-a-remote-server/ | Author Posts
I'm trying to run a script from my local server where the script resides on the remote target server. I have a UNC path to the remote script so I thought I could just point to it, but that didn't work. I saw a post somewhere about copying the script to a local variable and then use ScriptBlock to run it. The remote script does nothing but echo the parameter passed into a log file that I then copy back. I run this as a test:
$server='myserver'$scriptpath='\\myserver\d$\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1'$SDFEnvironment='INT'
$script=Get-Content$scriptpath
Invoke-Command -ComputerName $server -ScriptBlock {$script} -ArgumentList($SDFEnvironment) and it returns to the PS prompt, but when I inspect the target script directory there's no log file. Since the target script does nothing but write to the log file there should be something. Here's what I'm trying to run on the remote server: Param ( # SDF Environment [Parameter(Position=0)] [string]$SDFEnvironment
)
if ($PSBoundParameters.ContainsKey('SDFEnvironment')) { "Script Ran Env$SDFEnvironment"|Out-File -FilePath .\$SDFEnvironment"_LogFile.txt" -Encoding ascii -Force } else { "Environment Parameter missing"|Out-File -FilePath .\"ERR_LogFile.txt" -Encoding ascii -Force } Am I missing something basic? How can I tell (aside from script output) whether or not the script is actually running? Rather than using a UNC, which will engage a second remote access hop, try using a local path. Also, confirm the execution policy of the remote machine. And -ArgumentList doesn't work quite that way. But mainly, your script block isn't running the script. It's merely getting the content of the script, no? How can I use a local path if the script resides on the remote server? If ArgumentList doesn't quite work that way, how should I code it to pass the SDFEnvironment variable to the remote script as the 0-th position parameter? It's supposed to run the script, but it appears it isn't. Note: Clearly I'm a newbie to PS. My company wants me to use it but won't pay for training. I watched three videos on MS Virtual Academy and wrote a number of local scripts that worked very well. This is my first foray into remoting. I made this change (removed the {} around the$script variable and added try..catch)
try
{
Invoke-Command -ComputerName $server -ScriptBlock$script -ArgumentList $SDFEnvironment } catch { Write-Output "Error running remote script" } and I get this: Error running remote script So it looks like now it's executing the script, I just need to figure out the error which I assume is related to ArgumentList? – A path that's local for the remote machine. When you ask it to use a UNC, it can't, because that forces remote access and your credential can't be delegated a second time by default, so the UNC access fails. – The -ArgumentPath parameter is intended to pass parameters to a Param() block defines in -ScriptBlock. Below, I'm using a v4 technique to pass the local variable values to the remote machine. You'll notice that, before, even your$script variable wouldn't have worked, because $script wasn't defined on the remote machine. -ScriptBlock isn't evaluated for local variables unless you use$using.
– You weren't trying to execute the script, you were trying to display its contents. Keep in mind that everything in -ScriptBlock is passed literally to the remote computer, which means you were having the remote computer run Get-Content. You weren't having the remote computer run Get-Content, pass the results back to you, and then somehow executing those results as a script.
Your company's setting you up to fail, unfortunately. PowerShell has a lot of stuff that's non-obvious, and you're going to end up banging your head into it a lot. I'd at least recommend investing in "Learn PowerShell in a Month of Lunches," which is under $40, and in this specific case, "Secrets of PowerShell Remoting," which is free. Pluralsight also has some excellent PowerShell training videos and runs around$30/month. If you're going to make this a part of your career – and you should! – it might be worth a small investment of your own, so that you can eventually go find a better company.
$server='my server'$scriptpath='d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1'
$SDFEnvironment='INT' Invoke-Command -ComputerName$server -ScriptBlock {$using:script path -SDF$using:sdfenvironment}
In your second case, you're now telling YOUR computer to go get the script from a file share, and then pass it to Invoke-Command to run on the remote machine.
Frankly, there's no need to be using Try/Catch at this point in your experiment. Let it show you the actual error message (which you're suppressing by catching it) so you can see what's happening.
Using the UNC with Get-Content the $script variable contains the entire remote script in a local variable. I was under the impression I could run the script on the remote machine that way. I'll try your way but I have one question: $server='my server'
$scriptpath='d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1'$SDFEnvironment='INT'
Invoke-Command -ComputerName $server -ScriptBlock {$using:script path -SDF $using:sdfenvironment} The "-SDF" – is that supposed to be the parameter designation? I need to pass it positionally. I don't know or have control over the scripts on the remote machines other than to tell them the first (0-th) parameter has to be a string with the Environment name in it. I can't tell them what to call it. I used the same name in my test remote script as my test local script because I wrote them both. It won't always be that way. Can I just leave out the "-SDF" and use: $server='my server'
$scriptpath='d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1'$SDFEnvironment='INT'
Invoke-Command -ComputerName $server -ScriptBlock {$using:script path $using:sdfenvironment} "Using the UNC with Get-Content the$script variable contains the entire remote script in a local variable."
Except, not really, no. You're on Computer A. You're telling Computer B to reach out to Computer B and get the contents of a script located in a file share, and then in a second step telling Computer B to execute that contents of that script. It's overwrought, and it isn't how Remoting works, really. And you're engaging a second authentication hop, which won't work. if you want Computer B running the script, you just tell it to. There's no reason to Get-Content. What you were attempting to do would involve significantly more back-and-forth than needed, even assuming you sorted out the extra (and unnecessary) authentication hop.
"The "-SDF" – is that supposed to be the parameter designation? I need to pass it positionally."
Yes, because in your script you defined a parameter with that name. I truncated the name, which PowerShell allows. But, if you want to pass it positionally, that's fine. Just eliminate the "-SDF."
OK, so this:
$server='ad1hfdahp802'$scriptpath='d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1'
$SDFEnvironment='INT' Invoke-Command -ComputerName$server -ScriptBlock {$using:scriptpath$using:sdfenvironment}
Results in this:
At line:5 char:70
+ Invoke-Command -ComputerName $server -ScriptBlock {$using:scriptpath $using:sdfe ... + ~~~~~~~~~~~ Unexpected token '$using:sdfenvironment' in expression or statement.
+ CategoryInfo : ParserError: (:) [], ParentContainsErrorRecordException
+ FullyQualifiedErrorId : UnexpectedToken
If I put the "-SDF" back in it barfs on that first. I'm running this in the ISE and in the script editor I'm getting a squiggly under the $using:sdfenvironment and when I hover over it the prompt says "Unexpected token..." Oh. You're using v2 or v3. Ugh. $server='ad1hfdahp802'
$scriptpath='d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1'$SDFEnvironment='INT'
Invoke-Command -ComputerName $server -ScriptBlock { Param($one,$two)$one $two } -Arg$scriptpath,$sdfenvironment Which is what we had to do before$using. And, incidentally, how -ArgumentList works ;).
Nope. Local computer:
Name Value
---- -----
PSVersion 4.0
WSManStackVersion 3.0
SerializationVersion 1.1.0.1
CLRVersion 4.0.30319.42000
BuildVersion 6.3.9600.16406
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0}
PSRemotingProtocolVersion 2.2
and Remote Server:
Name Value
---- -----
PSVersion 4.0
WSManStackVersion 3.0
SerializationVersion 1.1.0.1
CLRVersion 4.0.30319.42000
BuildVersion 6.3.9600.16406
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0}
PSRemotingProtocolVersion 2.2
But I'll try the alternate method anyway. I'm getting a little desperate.
Here's what I got running the "old version" code:
At line:5 char:27
+ Param($one,$two) $one$two } -Arg $scriptpath,$sdfenvironment
+ ~~~~
Unexpected token '$two' in expression or statement. + CategoryInfo : ParserError: (:) [], ParentContainsErrorRecordException + FullyQualifiedErrorId : UnexpectedToken Well, let's take the variables out of it, because your shell isn't behaving the way I'm used to. Invoke-Command -ComputerName ad1hfdahp802 -ScriptBlock { d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1 INT } So just one command, all static values. Eliminate complexity. OK. That got somewhere. I got back: PS C:\users\rs02130\Desktop\Projects\AHP\xml> Invoke-Command -ComputerName ad1hfdahp802 -ScriptBlock { d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1 INT } Running Script PS C:\users\rs02130\Desktop\Projects\AHP\xml> Which show the output from the Write-Output in the script. I also have a pipe to Out-File that should create a log file on the remote server and that's not getting created. Here's the remote script boiled down to it's simplest Param ( # SDF Environment [Parameter(Position=0)] [string]$SDFEnvironment
)
Write-Output "Running Script"
"Script Ran Env $SDFEnvironment"|Out-File -FilePath .\$SDFEnvironment"_LogFile.txt" -Encoding ascii -Force
Inside your script, you're using a relative path. I wouldn't do that. You don't necessarily know what path the shell is going to default to (it won't necessarily be the path the script is located within) when it runs.
Also, I'm not sure this:
.\$SDFEnvironment"_LogFile.txt" Is producing the results you expect. ".\$SDFEnvironment_LogFile.txt"
Would work better, I suspect.
Nope. That didn't produce an output file either. I looked in the remote computer folder where the ps1 file is and in the local folder where I'm running the code in the ISE. No text file. I wrapped the Invoke-Command in a Try..Catch just to see if it was throwing an error I wasn't seeing and it didn't drop into the Catch block so...
I even took the variable out of the file name so it was just .\LogFile.txt and I didn't get an output file. I updated the Write-Output so it writes out the value of $SDFEnvironment to make sure that is getting through and it is: Remote Script: Param ( # SDF Environment [Parameter(Position=0)] [string]$SDFEnvironment
)
Write-Output "Running Script - $SDFEnvironment" "Script Ran Env$SDFEnvironment"|Out-File -FilePath .\LogFile.txt -Encoding ascii -Force
Tried the above with both .\LogFile.txt and ".\LogFile.txt"
Output:
PS C:\users\rs02130\Desktop\Projects\AHP\xml>
d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1 INT
}
Running Script - INT
PS C:\users\rs02130\Desktop\Projects\AHP\xml>
Also, looking to buy your book. Latest update on Amazon is for PS V3: http://www.amazon.com/Learn-Windows-PowerShell-Month-Lunches/dp/1617291080/ref=sr_1_1?ie=UTF8&qid=1454348484&sr=8-1&keywords=Learn+PowerShell+in+a+Month+of+Lunches
Is there a PS V4 version out? If not, is one planned?
So, because I want you to learn this stuff, what would you try next?
Me, I'd try going to the server and running that script manually. Make sure the script is working before we try to get it to work remotely.
Regarding the book, https://www.manning.com/books/learn-windows-powershell-in-a-month-of-lunches-second-edition is the latest version. There was no need to do a v4 or v5 update, as it covers basics that haven't changed.
Sorry, should have mentioned that at the top. Before I even tried to run it remotely I logged into the server console and made sure the script ran locally. It does exactly what you'd expect. Writes the message to the console (Write-Output) and creates the LogFile.txt (or INT_LogFile.txt with the original code) in the same directory as the script.
I'm wondering if the Out-File is actually running but the LogFile.txt is ending up somewhere odd, like c:\windows\system32... I'm going to poke around the file system on the server and see if something like that is happening. Maybe I need to pass in the path I'm using so I can specify a full path/file name for the log file. Should need to but I've seen stranger things.
Well, that was my point with the relative path you're using, vs. an absolute path like c:\files\whatever.txt. The shell is likely defaulting to C:\Windows\System32 when you connect.
The log files were ending up in my profile somewhere, at least that's what Search was turning up, although I couldn't access them.
Changed the Out-File to specify the full path and it now works correctly from both local and remote.
So, back to how to specify the script path and parameters programmatically... I can't use this:
Invoke-Command -ComputerName ad1hfdahp802 -ScriptBlock {
d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1 INT
}
in real life...
Right. So, now that we've got the remote script working, we can work on that. Let's do just one thing. I find it's often easier to walk into things one step at a time, so if something breaks, you know exactly what it is.
Try 1:
Invoke-Command -ComputerName ad1hfdahp802 -ScriptBlock {
param($a) d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1$a
} -Arg 'INT'
Try 2:
$a = 'INT' Invoke-Command -ComputerName ad1hfdahp802 -ScriptBlock { d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1$using:a
}
I'm just curious to see what happens either way. Do make sure you're running the shell as someone with remote access to the remote machine – normally, someone who's in the local Administrators group on the remote box.
Try 1 and Try 2 both worked. Given that the server name is outside the ScriptBlock and Arg list I put that in a variable also:
$s='ad1hfdahp802'$a = 'INT'
Invoke-Command -ComputerName $s -ScriptBlock { d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1$using:a }
which worked fine.
I poked at #1 some more and tried the following which also works:
$s='ad1hfdahp802'$arg='INT'
Invoke-Command -ComputerName $s -ScriptBlock { param($a)
d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1 $a } -Arg$arg
So the next thing is how to calculate the path to the ps1 file in a variable outside the ScriptBlock and then use that variable inside the ScriptBlock...
Just to be certain it wasn't just a problem with the PS install on my computer I ran this from above on another computer also running 4.0:
$server='ad1hfdahp802'$scriptpath='d:\AHP\pi_exceed_presentation\pi_exceed_presentation_deploy.ps1'
$SDFEnvironment='INT' Invoke-Command -ComputerName$server -ScriptBlock {$using:scriptpath$using:sdfenvironment}
With the same result. In the Script window of the ISE I get a squiggly under the second "using" and if I hover over it the pop-up says "Unexpected token '$using:SDFEnvironment'..." You don't get this error if you put this code into the Script window of the ISE? Can you share your$PSVersionTable? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.3842760920524597, "perplexity": 2719.6622411216395}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-39/segments/1537267162385.83/warc/CC-MAIN-20180925182856-20180925203256-00229.warc.gz"} |
http://www.distance-calculator.co.uk/towns-within-a-radius-of.php?t=Laugnac&c=France | Cities, Towns and Places within a 60 mile radius of Laugnac, France
Get a list of towns within a 60 mile radius of Laugnac or between two set distances, click on the markers in the satelitte map to get maps and road trip directions. If this didn't quite work how you thought then you might like the Places near Laugnac map tool (beta).
The radius entered failed to produce results - we reset it to a max of 60 miles - apologies for any inconvenience
# Distance Calculator > World Distances > Radius Distances > Laugnac distance calculator > Laugnac (France ) Radius distances
Get towns between and Miles KM
Click to View Visual Places on Map or View Visual Radius on Map
miles
Showing 0100 places between 10 and 60 miles of Laugnac
(Increase the miles radius to get more places returned *)
< 25 miles > 25 miles
Bazens, France is 10 miles away
Boe, France is 10 miles away
Bon-encontre, France is 10 miles away
Bourran, France is 10 miles away
Cassignas, France is 10 miles away
Clermont-dessous, France is 10 miles away
Hautefage-la-tour, France is 10 miles away
Monclar, France is 10 miles away
Monclar-d agenais, France is 10 miles away
Pailloles, France is 10 miles away
Pradie, France is 10 miles away
Saint-caprais-de-lerm, France is 10 miles away
Auradou, France is 11 miles away
Bruch, France is 11 miles away
Castelculier, France is 11 miles away
Clairac, France is 11 miles away
Estillac, France is 11 miles away
Lafox, France is 11 miles away
Ledat, France is 11 miles away
Port-sainte-marie, France is 11 miles away
Sauveterre-saint-denis, France is 11 miles away
Aiguillon, France is 12 miles away
Brugnac, France is 12 miles away
Coulx, France is 12 miles away
Frespech, France is 12 miles away
Moirax, France is 12 miles away
Nicole, France is 12 miles away
Penne-d agenais, France is 12 miles away
Saint-pastour, France is 12 miles away
Saint-pierre-de-clairac, France is 12 miles away
Saint-sylvestre-sur-lot, France is 12 miles away
Beaugas, France is 13 miles away
Castelnaud-de-gratecambe, France is 13 miles away
Cauzac, France is 13 miles away
Colombie, France is 13 miles away
Combet, France is 13 miles away
Dondas, France is 13 miles away
Grateloup, France is 13 miles away
Layrac, France is 13 miles away
Massels, France is 13 miles away
Moncaut, France is 13 miles away
Montagnac-sur-auvignon, France is 13 miles away
Puymirol, France is 13 miles away
Saint-jean-de-thurac, France is 13 miles away
Saint-martin-de-beauville, France is 13 miles away
Brech, France is 14 miles away
Feugarolles, France is 14 miles away
Laplume, France is 14 miles away
Saint-amans-du-pech, France is 14 miles away
Saint-leger, France is 14 miles away
Saint-nicolas-de-la-balerme, France is 14 miles away
Thouars-sur-garonne, France is 14 miles away
Verteuil-d agenais, France is 14 miles away
Calignac, France is 15 miles away
Cancon, France is 15 miles away
Caudecoste, France is 15 miles away
Fals, France is 15 miles away
Lucmau, France is 15 miles away
Monheurt, France is 15 miles away
Moulinet, France is 15 miles away
Saumon, France is 15 miles away
Savignac-sur-leyze, France is 15 miles away
Tombeboeuf, France is 15 miles away
Tonneins, France is 15 miles away
Tourtres, France is 15 miles away
Trentels, France is 15 miles away
Vares, France is 15 miles away
Villebramar, France is 15 miles away
Buzet-sur-baise, France is 16 miles away
Damazan, France is 16 miles away
Dausse, France is 16 miles away
Espiens, France is 16 miles away
Hautesvignes, France is 16 miles away
Labretonie, France is 16 miles away
Monbahus, France is 16 miles away
Nomdieu, France is 16 miles away
Saint-beauzeil, France is 16 miles away
Vianne, France is 16 miles away
Agme, France is 17 miles away
Allemans, France is 17 miles away
Belot, France is 17 miles away
Cazideroque, France is 17 miles away
Costes, France is 17 miles away
Fauillet, France is 17 miles away
Gontaud, France is 17 miles away
Guinot, France is 17 miles away
Lacour, France is 17 miles away
Lavardac, France is 17 miles away
Monflanquin, France is 17 miles away
Perville, France is 17 miles away
Puch, France is 17 miles away
Puch-d agenais, France is 17 miles away
Roquecor, France is 17 miles away
Saint-auban-sur-durance, France is 17 miles away
Saint-maurice-de-lestapel, France is 17 miles away
Saint-maurin, France is 17 miles away
Saint-pierre-de-buzet, France is 17 miles away
Tourmi, France is 17 miles away
Tremons, France is 17 miles away
Villeton, France is 17 miles away
Click to See place names or View Visual Places on Map
Click to go to the top or View Visual Radius on Map
World Distances
Need to calculate a distance for Laugnac, France - use this Laugnac distance calculator.
To view distances for France alone this France distance calculator
If you have a question relating to this area then we'd love to hear it! Chec out our facebook, G+ or Twitter pages above!
Don't forget you can increase the radius in the tool above to 50, 100 or 1000 miles to get a list of towns or cities that are in the vicinity of or are local to Laugnac. You can also specify a list of towns or places that you want returned between two distances in both Miles(mi) or Kilometres (km) .
Europe Distances
* results returned are limited for each query | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9001225829124451, "perplexity": 9410.691355639277}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178368608.66/warc/CC-MAIN-20210304051942-20210304081942-00493.warc.gz"} |
https://mersenneforum.org/showpost.php?s=96606628e98dc0393bf5d1ad876bba4d&p=317754&postcount=2 | View Single Post
2012-11-09, 21:16 #2 ewmayer ∂2ω=0 Sep 2002 República de California 2×3×29×67 Posts Any such estimate needs to take into account the special "restricted" form of Mersenne factors, which in general will cause M(p) (and by extension M(M(p) for M(p) prime) to have a lower expected number of factors than a general odd number of similar size. Here is a paper I found via cursory online search - the paper itself is not so much of interest in the present context as are the references, several of which appear to have investigated the question you ask. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8465497493743896, "perplexity": 1179.7791020193463}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-43/segments/1634323583423.96/warc/CC-MAIN-20211016043926-20211016073926-00613.warc.gz"} |
https://www.physicsforums.com/threads/variational-methods-on-lagrangians-dinverno-chapter-11.402515/ | # Variational methods on Lagrangians (D'Inverno Chapter 11)
1. May 11, 2010
### TerryW
Oh dear! I thought I had cracked chapter 11 and had done all the problems. However, when I came to write up the answers I realised my answer to Problem 11.7 didn't work. I thought I had a simple answer to (i) but then used the same process for (ii) and ended up with +Rab.
My approach to (i) was to simply take the equation for Lg = (-g)1/2 R
So Lg =(-g)1/2gabRab
So LG = gothic'g' $$\delta$$Rab
I then just take a variation wrt the dynamic variable gothic'g' to get the desired result.
I realise that I haven't taken a Leibnitz product variation so I have ignored the term gothic'g' $$\delta$$Rab. Is it necessary to do this and then prove that gothic'g' $$\delta$$Rab = 0? Any thoughts on how to do this?
(Anyone know how to to the gothic G for tensor weights?)
Last edited: May 11, 2010
2. May 13, 2010
### Altabeh
You don't actually need to prove the second part because the variation of the Ricci tensor wrt any metric density of either covariant or contravariant type is automatically zero. This is obviously because the Ricci tensor lacks any weight factor $$\sqrt{-g}$$ and this is all due to it being a tensor not a tensor density. Remember that the variation of the Ricci tensor does not vanish by itself unless it is contained in a boundary (surface) integral equation as in the derivation of Einstein's field equations themselves.
And I was wondering if I could know what your 'gothic' means!!
AB
Last edited: May 13, 2010
3. May 13, 2010
### Altabeh
About the part (iii) you have to note that there must be a constraint of the form
$$\frac{(-\mathfrak{g}^{cd}\delta \Gamma^{k}_{cd}+\mathfrak{g}^{ck}\delta \Gamma^{d}_{cd})_{;k}}{\delta g^{ab}}=0,$$
which is derived by the use of the Palatini equation for the variation of the Ricci tensor. I have to recall that again in a surface integral as in the Hilbert-Einstein action, the numerator of this equation automatically vanishes, leading to a no-constraint form of the answer to the part (iii).
AB
Last edited: May 13, 2010
4. May 14, 2010
### TerryW
I'm still not sure why I can ignore the $$\delta$$Rab. As you say 'the variation of the Ricci tensor does not vanish by itself unless it is contained in a boundary (surface) integral equation..' When we are just taking the variation on its own, it isn't contained in a surface integral so I don't see how we can just assume it is zero. I've tried to prove that
$$\delta$$Rab = 0 but without success.
If you do assume that $$\delta$$Rab is zero, it enables you to reach the answers for (i), (ii) and (iii) except that my answer for (ii) comes out as +Rab not -Rab.
My working is as follows:
LG = $$\sqrt{(-g)}$$ R = $$\sqrt{(-g)}$$ gab Rab = $$\mathfrak{g}_{ab}$$ Rab
$$\delta$$LG/$$\delta\mathfrak{g}^{ab}$$ = Rab.
When I created the post, I didn't know how to write $$\mathfrak{g}^{ab}$$, which what I meant by gothic 'g', but you used the appropriate LaTeX in your reply which I have now stored in my file of useful LaTex
I didn't see any need for the additional constraint for (iii) but I did identify one for (ii). It wasn't the same as yours, mine was:
$$\nablab \sqrt{(-g)}$$gabR = 0. But this is zero anyway!
(And I just cannot get this last line of LaTeX to work!)
Last edited: May 14, 2010
5. May 15, 2010
### Altabeh
You seem to have completely misunderstood me. The variation of the Ricci tensor is by no means zero generally. I assume here that you can simply prove the part (i); so I'm going to give you a hint on how to derive (ii).
As for (ii), I assume you can simply find that
$$\delta (\mathfrak{g}^{ab}R_{ab})=\delta \mathfrak{g}^{ab}R_{ab}+\delta R_{ab}\mathfrak{g}^{ab}.$$
I gave you a clue that since the variation is with respect to a metric density, so that
$$\frac{\delta R_{ab}}{\delta \mathfrak{g}_{cd}}\mathfrak{g}^{ab}=0.$$
Having been said, this is just because the variation of a tensor with respect to a density is always zero. (Indeed, there is no weight factor within $$R_{ab}$$).
Now we are left with
$$\frac{\delta \mathfrak{L}_G}{\delta \mathfrak{g}_{cd}}=\frac{\delta \mathfrak{g}^{ab}}{\delta \mathfrak{g}_{cd}}R_{ab}.$$
Try to obtain the result
$$\delta \mathfrak{g}^{ab} R_{ab}=-\delta g_{ab}\sqrt{-g}G^{ab}.$$
(Hint: Get a hand from the equation (11.34).)
From this you are able to write
$$\delta \mathfrak{g}^{ab} R_{ab}=-\delta \mathfrak{g}_{ab}R^{ab}+\frac{1}{2}g^{ab}R\delta\mathfrak{g}_{ab}-\delta\sqrt{-g}R.$$
Now it all falls upon you to reveal the rest of the calculation.
For the part (iii), I tried to use the Palatini approach, but you seemed to fail in understanding it. It can be obtained simply in way similar to the one D'inverno shows in the equation (11.34). Just think of it and if you didn't come up with anything, I'd go into its detail, too. Remember that all three parts include in a special constraint which is relevant to the divergence of the Einstein tensor density.
AB
Last edited: May 15, 2010
6. May 16, 2010
### TerryW
Hi Altabeh
Ah! I see what you are getting at now. But I have looked back through D'Inverno and I cannot find anything that established the rather crucial result that the variation of a tensor wrt a density is always zero. Can you point me in the direction of a proof anywhere?
Yes I have done this!
I have done this too but my answer is not quite what you have written, I get:
$$\delta \mathfrak{g}^{ab} R_{ab}=-\delta \mathfrak{g}_{ab}R^{ab}+\frac{1}{2}g^{ab}R\sqrt{-g}\delta g_{ab}-\delta\sqrt{-g}R.$$
This then reduces to
$$\delta \mathfrak{g}^{ab} R_{ab}=-\delta \mathfrak{g}_{ab}R^{ab}$$
because
$$\frac{1}{2}g^{ab}R\sqrt{-g}\delta g_{ab}-\delta\sqrt{-g}R = 0$$
(Once again my LaTex equation does not appear as I intend!)
I used a slightly different approach to (iii) in which I start with (i) and just expand
$$\delta\mathfrak{g}_{ab}$$ but it works out OK.
Reqards Terry
Last edited: May 16, 2010
7. May 17, 2010
### Altabeh
Hi and my pleasure!
I think this is trivial! The variation of $$\sqrt{-g}$$ again contains a weight factor $$\sqrt{-g}$$ which when multiplied by a metric tensor would give a metric density, something that tensors and their variations don't have. That is, the lack of $$\sqrt{-g}$$ in tensors and consequently in their variations leads to the following general formula:
$$\frac{\delta T_{ab..}^{a'b'..}}{\delta \mathfrak{g}_{ab}}=0.$$
Imagine now $$T_{ab..}^{a'b'..}$$ is accompanied by a weight factor $$\sqrt{-g}$$. Thus we have a tensor density of order (p,q) where p and q represent respectively the number of lower and upper indices. We know that
$$\delta(\sqrt{-g}T_{ab..}^{a'b'..}) = \delta \sqrt{-g}T_{ab..}^{a'b'..}+\delta T_{ab..}^{a'b'..} \sqrt{-g},$$ *
and that
$$\delta \sqrt{-g}= \frac{1}{2}\sqrt{-g} g^{ab}\delta g_{ab}=\frac{1}{2} g^{ab}\delta \mathfrak{g}_{ab}-2\delta \sqrt{-g}\rightarrow$$
$$\delta \sqrt{-g}=\frac{1}{6}g^{cd}\delta \mathfrak{g}_{cd}.$$
So combining this last result with the equation * yields
$$\delta(\sqrt{-g}T_{ab..}^{a'b'..}) = \frac{1}{6}g^{cd}\delta \mathfrak{g}_{cd}T_{ab..}^{a'b'..}+\delta T_{ab..}^{a'b'..} \sqrt{-g},$$
and thus
$$\frac{\delta(\sqrt{-g}T_{ab..}^{a'b'..})}{\delta \mathfrak{g}_{ab}} =\frac{1}{6}g^{cd}T_{cd..}^{a'b'..}.$$
Which is obviously generally non-zero.
For the case of the Ricci tensor, it should be pointed out that the change of the contracted Christoffel symbols $$\Gamma^{a}_{ab}$$ with $$\frac{1}{2}\frac{\partial \ln(-g)}{\partial x^b}$$ may be tricky as it sounds like some squared weight factors would appear along with the metric tensors. But this is again like we are running in circles as in the end we will be left with the terms involving the product of the first derivatives of the metric tensor and itself, meaning that varying the Ricci tensor wrt the metric density is always zero.
There you have written the second term on the right hand side of the first equation from top incorrectly. It would be great if I could see how you got this. But by my own calculation the most simplified equation we hit in the end is
$$\delta \mathfrak{g}^{ab} R_{ab}=-\delta \mathfrak{g}_{ab}R^{ab}+2\delta\sqrt{-g}R,$$
which leads to the same result as in (i) if you proceed to compute it wrt the variation $$\delta\mathfrak{g}_{ab}.$$
If that works, so it's okay!
AB
Last edited: May 17, 2010
8. May 17, 2010
### Altabeh
If there is nothing ambiguous here with these questions, and of course if you allow me, I'd like to put your intelligence to test here and ask you the following neat question to only see if you are really good at dealing with this tensor-density thing:
Calculate the variation of the Lagrangian $$\mathfrak{L}_G=\sqrt{-g}g^{ab}R_{ab}$$ wrt $$g^{ab}.$$ How can we prove the variation of the Ricci tensor wrt the metric tensor vanishes if we want to have (iii) hold!?
AB
Last edited: May 17, 2010
9. May 17, 2010
### TerryW
Hi Altabeh,
This is quick reply to your post just to give you my workings on the equation where we have a different result.
I really do appreciate the time and effort you are putting in on my behalf. Your latest post has given me a lot to think about but I won't now be able to get back to you for a few weeks because I am going away on holiday. I will however take your posts and D'Inverno with me on holiday and get back in touch with you when I return.
Regards for now,
Terry
Starting from the result you led me to (and expanding Gab)
1. $$\delta \mathfrak{g}^{ab} R_{ab}= -\delta g_{ab}\sqrt{-g}(R^{ab}-\frac{1}{2}g^{ab}R)$$
Then expanding out $$\delta \mathfrak{g}_{ab} R^{ab}$$
2. $$\delta \mathfrak{g}_{ab} R^{ab}= \delta g_{ab}\sqrt{-g}R^{ab}+g_{ab}R^{ab} \delta\sqrt{-g}$$
(I'm still getting odd results when I look at the saved post. The LaTeX for the second equation is
\delta \mathfrak{g}_{ab} R^{ab}= \delta g_{ab}\sqrt{-g}R^{ab}+g_{ab}R^{ab} \delta\sqrt{-g}
But the result of the rendering seems to introduce an extra $$\sqrt{-g}$$ before the $$\delta\sqrt{-g}$$at the end.)
I am now looking at the post a day later and the second equation now reads correctly!
We can add the two equations together and reorganise the terms to get what I got!
Last edited: May 18, 2010
10. May 18, 2010
### Altabeh
Have a good holiday.
I still don't get how you manage to get your result from this. Hope to make it clear for after you are back from holiday.
AB
11. May 18, 2010
### TerryW
Hi Altabeh,
I had another look at my post this morning and realised that when I add the two equations together, I had made an error and made one quantity -ve when it should have been +ve. So my equations added together now produce the same result as yours!
Regards
Terry
12. Jun 25, 2010
### TerryW
Hi Altabeh,
I'm back from my holiday and keen to get back on with our discussion.
Let me see if I can rise to the challenge!
$$\mathfrak{L}_G=\sqrt{-g}g^{ab}R_{ab}$$
So $$\delta \mathfrak{L}_G = \delta \sqrt{-g}g^{ab}R_{ab} + \sqrt{-g}\delta g^{ab}R_{ab} + \sqrt{-g}g^{ab}\delta R_{ab}$$
$$\delta \mathfrak{L}_G = \frac{1}{2} \sqrt{-g}g^{cd}\delta g_{cd}g^{ab}R_{ab} + \sqrt{-g}\delta g^{ab}R_{ab} + \sqrt{-g}g^{ab}\delta R_{ab}$$
$$\delta \mathfrak{L}_G = \frac{1}{2} \sqrt{-g}g^{ab}\delta g_{ab}g^{cd}R_{cd} + \sqrt{-g}\delta g^{ab}R_{ab} + \sqrt{-g}g^{ab}\delta R_{ab}$$
$$\delta \mathfrak{L}_G = -\frac{1}{2} \sqrt{-g}g_{ab}\delta g^{ab}g^{cd}R_{cd} + \sqrt{-g}\delta g^{ab}R_{ab} + \sqrt{-g}g^{ab}\delta R_{ab}$$
$$\delta \mathfrak{L}_G = -\frac{1}{2} \sqrt{-g}g_{ab}\delta g^{ab}R + \sqrt{-g}\delta g^{ab}R_{ab} + \sqrt{-g}g^{ab}\delta R_{ab}$$
$$\delta \mathfrak{L}_G = \sqrt{-g}\delta g^{ab}(-\frac{1}{2}g_{ab}R + R_{ab}) + \sqrt{-g}g^{ab}\delta R_{ab}$$
$$\delta \mathfrak{L}_G = \sqrt{-g}\delta g^{ab}G_{ab} + \sqrt{-g}g^{ab}\delta R_{ab}$$
$$\frac {\delta \mathfrak{L}_G}{\delta g^{ab}} = \sqrt{-g}G_{ab} + \sqrt{-g}g^{ab}\frac{\delta R_{ab}}{\delta g^{ab}}$$
So if (iii) is to hold, then $$\sqrt{-g}g^{ab}\frac{\delta R_{ab}}{\delta g^{ab}} = 0$$
ie $$\frac{\delta R_{ab}}{\delta g^{ab}} = 0$$
But does this really prove that the change of the Ricci tensor wrt the metric tensor is zero?
13. Jun 25, 2010
### haushofer
No, it doesn't. The action principle with the Hilbert action states that the variation of the Hilbert action wrt the metric is zero. The Hilbert action is
$$S[g_{\mu\nu}] = \int \sqrt{|g|}g^{\mu\nu}R_{\mu\nu}d^{4}x$$
Varying the Lagrangian L (including the square root of the metric in the measure) gives
$$\delta L = \sqrt{|g|}(\frac{1}{2}Rg^{\alpha\beta}-R^{\alpha\beta})\delta g_{\alpha\beta} + \sqrt{|g|}g^{\mu\nu}(\nabla_{\alpha}\delta\Gamma^{\alpha}_{\mu\nu} - \nabla_{\nu}\delta\Gamma^{\alpha}_{\mu\alpha})$$
One can show that for a large class of Lagrangians the variation reads
$$\delta L = E^{\alpha\beta}\delta g_{\alpha\beta} + \nabla_{\alpha}\Theta^{\alpha}$$
The first term on the RHS, the E, is the equations of motion, and the second term is a boundary term. With suitable boundary conditions this term becomes a boundary term in the action via Stokes, and the boundary conditions put this term to zero. However, if you don't impose these boundary terms, you need the Hawking-Gibbons boundary term in your action, which is constructed from the extrinsic curvature. For your Hilbert action this Theta becomes, written as a three-form,
$$\Theta_{\mu\nu\rho}(g, \delta g) =\frac{1}{16\pi} \epsilon_{\alpha\mu\nu\rho}g^{\alpha\lambda}g^{\sigma\theta}(\nabla_{\sigma}\delta g_{\lambda\theta} - \nabla_{\lambda}\delta g_{\sigma\theta})$$
14. Jun 26, 2010
### Altabeh
Hi
In fact you had to be a little bit careful: D'inverno shows that the equation (11.33) reduces to (11.34) [and thus $$R_{ab}\delta{\mathfrak{g}^{ab}}=-\sqrt{-g}{G}^{ab}\delta{g_{ab}}$$] through imposing a boundary condition and Stokes theorem to eliminate the term including the variation of Ricci tensor in the action integral. This tells us that applying (iii) in the equation
$$\frac {\delta \mathfrak{L}_G}{\delta g^{ab}} = \sqrt{-g}G_{ab} + \sqrt{-g}g^{ab}\frac{\delta R_{ab}}{\delta g^{ab}}$$
calls for the vanishing of $$\frac{\delta R_{ab}}{\delta g^{ab}}$$ as a boundary condition in the action formula not by itself, as described by haushofer.
AB
15. Jul 1, 2010
### TerryW
Hi Altabeh and haushofer,
I've had a bit more time to look through all the posts so far and I'd like to refresh the thread with a summary of where it has taken me so far:
I started when I realised that in producing an answer to (i) of Problem 11.7 in D'inverno, I had ignored the term
$$\mathfrak{g}^{ab} \delta R_{ab}$$
This produced an extra term in the result for $$\delta \mathfrak{L}_G$$ but Altabeh has pointed out that
$$\frac{\delta R_{ab}}{\delta \mathfrak{g}^{ab}} \mathfrak{g}^{ab} = 0$$
I kind of understand what you are saying Altabeh, about why this is the case but I'd be happier if I could see a rigorous mathematical proof.
My next problem was with the answer to part (ii) and on looking through all the posts, I still have a problem with this.
We worked through and have got as far as proving:
$$\delta \mathfrak{g}^{ab} R_{ab} = - \delta \mathfrak{g}_{ab} R^{ab} +2 \delta \sqrt{-g} R$$
Now in Altabeh's post dated May 17, he shows that:
$$\delta \sqrt{-g} = \frac{1}{6} g^{ab}\delta \mathfrak{g}_{ab}$$
which leads me to:
$$\frac{\mathfrak L_G}{\delta \mathfrak{g}_{ab}} = - R^{ab} + \frac{1}{3} g^{ab} R$$
I understand the process which D'Inverno uses to reduce equation (11.33) to equation (11.34) but I still do not really understand why, for example,
$$\frac{\delta R_{ab}}{\delta g^{ab}}$$ is not part of the answer to 11.7 (iii) as it isn't part of an integral expression.
Sorry if I don't seem to be getting this. I hope you will persist with me until we have a resolution.
Regards
Terry | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9547947645187378, "perplexity": 465.29323329940826}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-13/segments/1521257648003.58/warc/CC-MAIN-20180322205902-20180322225902-00774.warc.gz"} |
http://www.emathzone.com/tutorials/math-results-and-formulas/results-and-formulas-of-beta-and-gamma-integrals.html | # Results and Formulas of Beta and Gamma Integrals
1)
It is called Beta Integral.
2)
It is called Gamma Integral.
3)
4)
5)
6)
7)
Where $n$ is a positive integer.
8)
If $n$ is not an integer on $0 < n < 1$
9)
10) When $n$ is large and positive, then approximation value of
It is called Stirrling Formula.
11)
12)
13) | {"extraction_info": {"found_math": true, "script_math_tex": 4, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 17, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9996848106384277, "perplexity": 2280.936178056161}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560282935.68/warc/CC-MAIN-20170116095122-00149-ip-10-171-10-70.ec2.internal.warc.gz"} |
https://www.asvabtestbank.com/general-science/flash-cards/781322/10 | General Science Flash Card Set 781322
Cards 10 Topics Cell Energy, Ecosystem, Force, Heart, Kinetic Energy, Liquid, Refraction, Tendons & Ligaments, Vectors
Study Guide
Cell Energy
Some plant cells produce their own energy through photosynthesis which is the process by which sunlight, carbon dioxide, and water react to make sugar and oxygen. Animal cells cannot produce their own energy and, instead, generate energy when mitochondria consume outside sugar and oxygen through aerobic respiration.
Ecosystem
An ecosystem is a biological community of interacting organisms and their physical environment. This includes both the biotic (living) and abiotic (non-living).
Force
Force is applied to change an object's speed or direction of motion.
Heart
The heart is the organ that drives the circulatory system. In humans, it consists of four chambers with two that collect blood called atria and two that pump blood called ventricles. The heart's valves prevent blood pumped out of the ventricles from flowing back into the heart.
Kinetic Energy
Kinetic energy is the energy posessed by a moving object. Potential energy is stored energy in a stationary object based on its location, position, shape, or state.
Liquid
In the liquid state, molecules flow freely around each other and exist at a higher temperature range than the same substance in a solid state. Liquids maintain a constant volume but their shape depends upon the shape of their container.
Refraction
Because different materials have different refractive indices, light changes speed when passing from one material to another. This causes the light to bend (refraction) at an angle that depends on the change in refractive index between the materials. The greater the difference, the higher the angle of refraction.
Tendons & Ligaments
Tough fibrous cords of connective tissue called tendons connect muscles to the skeleton while another type of connective tissue called ligaments connect bones to other bones at joints (elbow, knee, fingers, spinal column).
Vectors
Velocity and displacement are vector quantities which means each is fully described by both a magnitude and a direction. In contrast, scalar quantities are quantities that are fully described by a magnitude only. A variable indicating a vector quantity will often be shown with an arrow symbol: $$\vec{v}$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5209261178970337, "perplexity": 1841.3818468233262}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585371611051.77/warc/CC-MAIN-20200405213008-20200406003508-00498.warc.gz"} |
https://stats.stackexchange.com/questions/560547/why-does-v-bar-x-1-bar-x-2-frac-sigma-12n-1-frac-sigma-22/560551 | # Why does $V(\bar x_1 - \bar x_2) = \frac {\sigma_1^2}{n_1} + \frac {\sigma_2^2}{n_2}$? (Samples are independent)
I don't quite understand why this is the case. I'm new to stats and when I think variance, my mind immediately goes to $$S^2 = \frac {\sum(x_i - \bar x)^2}{n - 1}$$. Is there a rule that I'm ignorant of or is there a way to use this formula for two sample means and come up with $$\frac {\sigma_1^2}{n_1} + \frac {\sigma_2^2}{n_2}$$?
• What is the variance of $\bar X_1$ if the variance of $X_1$ is $\sigma^2_{X1}$? What is the variance of $-\bar X_2$ if the variance of $X_2$ is $\sigma^2_{X2}$? What is the variance of $Y+Z$ if $Y$ and $Z$ are independent and the variance of $Y$ is $\sigma^2_Y$ and the variance of $Z$ is $\sigma^2_Z$? Jan 14 at 23:11
• en.wikipedia.org/wiki/Variance#Basic_properties Jan 14 at 23:45
The first step is to 'distribute' the variance operator $$\mathbb{V}$$. When all samples are independent we can say
$$\mathbb{V}(\bar{X}_1 - \bar{X}_2) = \mathbb{V}(\bar{X}_1 ) + \mathbb{V}(\bar{X}_2).$$
The reason we add the variances is because it makes sense for the variance to increase as we add more observations. The more we add, the more 'randomness' we introduce. The variance also has the property that $$\mathbb{V}(aX) = a^2\mathbb{V}(X)$$, so in your case $$\mathbb{V}(-\bar{X}_2) = \mathbb{V}(\bar{X}_2)$$. See here for more details about the properties of the variance.
The second step is to 'expand' $$\mathbb{V}(\bar{X}_1)$$ and $$\mathbb{V}(\bar{X}_2)$$. In general
$$\bar{X}_i = \frac{1}{n_i}\sum_{j=1}^{n_i}X_{i,j}$$
and so
\begin{align} \mathbb{V}(\bar{X}_i) &= \mathbb{V}\bigg(\frac{1}{n_i}\sum_{j=1}^{n_i}X_{i,j}\bigg)\\ &= \frac{1}{n^2_i}\mathbb{V}\bigg(\sum_{j=1}^{n_i}X_{i,j}\bigg) &&\hspace{0.1cm} (\text{since } \mathbb{V}(aX) = a^2\mathbb{V}(X))\\ &= \frac{1}{n^2_i}\mathbb{V}(X_{i,1} + X_{i,2} + ... + X_{i,n_i})\\ &= \frac{1}{n^2_i}\big[\mathbb{V}(X_{i,1}) + \mathbb{V}(X_{i,2}) + ... + \mathbb{V}(X_{i,n_i}))\big] &&\hspace{0.1cm} (\text{since the samples are independent)} \end{align}
Now, if the data are from the same distribution with constant variance $$\sigma^2_i$$ then the variance of $$\bar{X}_i$$ becomes
$$\mathbb{V}(\bar{X}_i) = \frac{1}{n^2_i} \cdot n_i\sigma^2_i = \frac{\sigma^2_i}{n_i}.$$
Returning to the first step, this means that
$$\mathbb{V}(\bar{X}_1 - \bar{X}_2) = \frac{\sigma^2_1}{n_1} + \frac{\sigma^2_2}{n_2}.$$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 14, "wp-katex-eq": 0, "align": 1, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9970005750656128, "perplexity": 245.06887878049616}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 20, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-27/segments/1656104205534.63/warc/CC-MAIN-20220702222819-20220703012819-00422.warc.gz"} |
http://www.math-only-math.com/rational-numbers-on-the-number-line.html | # Rational Numbers on the Number Line
We will learn how to represent rational numbers on the number line with the help of the following examples.
1. Represent $$\frac{5}{3}$$ and $$\frac{-5}{3}$$ on the number line.
Solution:
In order to represent $$\frac{5}{3}$$ and $$\frac{-5}{3}$$ on the number line, we first draw a number
line and mark a point O on it to represent zero. Now we find the points X and X' on the number line representing the positive integers 5 and -5 respectively as shown in the below figure.
Now divide the segment OX into three equal parts. Let A and B be the points of division so that OA = AB = BX. By construction, OA is one-third of OX.
Therefore, A represents the rational number $$\frac{5}{3}$$.
Point X' represents -5 on the number line. Now, divide OX' into three equal parts OA', CB' and B'X'. The point A' is such that OA' is one third of OX'. Since X' represents the number -5.
Therefore, A' represents the rational number $$\frac{-5}{3}$$.
2. Represent $$\frac{8}{5}$$ and $$\frac{-8}{5}$$ on the number line.
Solution:
To represent $$\frac{8}{5}$$ and $$\frac{-8}{5}$$ on the number line, on the number line, draw a number line and mark a point O on it to represent zero. Now, mark two points M and M' representing integers 8 and -8 respectively on the number line. Divide the segment OM into five equal parts. Let A, B, C, D be the points of division so that OA = AB = BC = CD = DM. By construction, OA is one-fifth of OM. So, A represents the rational number $$\frac{8}{5}$$.
Now, M' represents -8 on the number line. Divide OM' into five equal parts OA', A'B', B'C', C'D', and D'M'. Since M' represents -8 . Therefore, A' represents the rational number -8/5.
Rational Numbers
What is Rational Numbers?
Is Every Rational Number a Natural Number?
Is Zero a Rational Number?
Is Every Rational Number an Integer?
Is Every Rational Number a Fraction?
Positive Rational Number
Negative Rational Number
Equivalent Rational Numbers
Equivalent form of Rational Numbers
Rational Number in Different Forms
Properties of Rational Numbers
Lowest form of a Rational Number
Standard form of a Rational Number
Equality of Rational Numbers using Standard Form
Equality of Rational Numbers with Common Denominator
Equality of Rational Numbers using Cross Multiplication
Comparison of Rational Numbers
Rational Numbers in Ascending Order
Representation of Rational Numbers on the Number Line
Addition of Rational Number with Same Denominator
Addition of Rational Number with Different Denominator
Properties of Addition of Rational Numbers
Subtraction of Rational Number with Different Denominator
Subtraction of Rational Numbers
Properties of Subtraction of Rational Numbers
Simplify Rational Expressions Involving the Sum or Difference
Multiplication of Rational Numbers
Properties of Multiplication of Rational Numbers
Rational Expressions Involving Addition, Subtraction and Multiplication
Division of Rational Numbers
Rational Expressions Involving Division
Properties of Division of Rational Numbers
To Find Rational Numbers | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8497537970542908, "perplexity": 1327.4011240350992}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-04/segments/1484560280133.2/warc/CC-MAIN-20170116095120-00003-ip-10-171-10-70.ec2.internal.warc.gz"} |
http://mathematicshelp.org/maths/forum/topic/57 | # Reduce the fraction
Marina
Visitor
2016-12-14 17:41:57
#1
Show that the following fraction is reductible:
$frac{abcabc}{cbacba}$
How can I show this? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9963757991790771, "perplexity": 4636.80759887901}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084890795.64/warc/CC-MAIN-20180121155718-20180121175718-00647.warc.gz"} |
https://www.physicsforums.com/threads/how-to-differentiate-vectors.413152/ | # How to Differentiate Vectors?
1. Jun 29, 2010
### EngWiPy
Dear all;
I need to find this derivative:
$$\frac{\partial}{\partial \mathbf{a}}\left(E-2\,\mathbf{a}^{\text{T}}\,E[\mathbf{s}]+\|\mathbf{a}\|^2\right)$$
where boldface letters indicates column vectors, the superscript T indicates transpose, and ||.|| is the norm of a vector.
2. Jun 29, 2010
### mathman
The notation is unusual. I have never seen a definition of a derivative with respect to a vector. The closest thing I can think of is the del operator.
3. Jun 29, 2010
### Pere Callahan
I think what is meant is
$$\frac{\partial}{\partial\vec a}f(\vec a) = \left(\frac{\partial}{\partial a_1}f(\vec a),\frac{\partial}{\partial a_2}f(\vec a),\frac{\partial}{\partial a_3}f(\vec a)\right)$$
which is of course very similar to the del operator.
So I suggest you write your function
$$f(\vec a) =E-2\,\vec a^{\text{T}}\,E[\vec s]+\|\vec a\|^2$$
explicitly in terms of the components $a_1, a_2, a_3$ (I assume its a three-dimensional vector, it wouldn't make a difference if it were not) and then compute the partial derivatives.
4. Jun 30, 2010
### EngWiPy
The vectors are N*1 column vectors. At the end, I need to find the derivative with respect to $$\mathbf{a}$$. How can I do that?
5. Jun 30, 2010
### HallsofIvy
In general, the derivative of a function f from $R^n$ to $R^m$ is the linear function from $R^n$ that "best" approximates the function f around the given point. "best" is made precise in the definition of the derivative.
Given a coordinate system (basis) in each space, we can then write the derivative as an n by m matrix. In this problem you are differentiating a scalar, in R, with respect to a vector in $R^3$ so this would be a "1 by 3" matrix which we would interpret as a 3-vector. Essentially, you treat the components of the vector as the three variables and this derivative is the same as taking the gradient, $\nabla f$, of a numerical function of three variables.
6. Jun 30, 2010
### uart
Then in that case I'd assume that the you are to find a column vector of partial derivates, as in :
$$\frac{\partial f}{\partial \mathbf{a}} = \left[\frac{\partial f}{\partial a_1}, \frac{\partial f}{\partial a_2}, \frac{\partial f}{\partial a_3}, ... \right]^{\text{T}} = 2 [ \mathbf{a} - E \mathbf{s}]$$
Assuming that "E" is a scalar then "f" is just a scalar (quadratic) function of $a_1,a_2, ... a_n$ right. So you should be able to verify the above should be easily enough.
Last edited: Jun 30, 2010
7. Jun 30, 2010
### Hurkyl
Staff Emeritus
You have been asked to clarify what your notation means. Please do so, rather than force people to guess what notational conventions you are using.
Also, I suggest you specify what E and [s] mean. (And if they have any functional dependence on a)
p.s. ||a||2 = aT a
8. Jun 30, 2010
### EngWiPy
I thought it is obvious, sorry. The terms are:
1- $$\mathbf{a}$$ is an $$N\times 1$$ column vector.
2-$$E$$ is a constant that does not depend on $$\mathbf{a}$$.
3- $$E[\mathbf{s}]$$ is another $$N\times 1$$ vector, that does not depend on $$\mathbf{a}$$.
4- $$\|\mathbf{a}\|^2$$ is as you clarified.
Thank you all, now I get it.
Regards
9. Jun 30, 2010
### Hurkyl
Staff Emeritus
I, in particular, was confused by the square brackets around s. (i.e. why not write Es?)
10. Jul 1, 2010
### EngWiPy
Yes, you are right, it is confusing, because the terms $$E$$ and $$E[\mathbf{s}]$$ are different. Let me re-write the original equation:
$$\mathcal{E}-2\,\mathbf{a}^{\text{T}}\,E[\mathbf{s}]+\|\mathbf{a}\|^2$$
and the term $$E[\mathbf{s}]$$ is written in this way, because in the context in which I am working in it is the statistical average of a number of vectors $$\left\{\mathbf{s}_i\right\}_{i=1}^{M}$$
Regards
11. Jul 1, 2010
### Studiot
Perhaps it would help simplify things if I pointed out that the norm of anything is a number ie a scalar.
12. Jul 1, 2010
### HallsofIvy
Yes, so the function to be differentiated is a number, not a vector. But it is being differentiated with respect to a vector. That is the whole point.
13. Jul 1, 2010
### Mute
Write it in index notation (repeated indices are assumed to be summed over):
$$f(\{a\}) = \mathcal E - 2 a_i E[\mathbf{s}]_i + a_i a_i$$
Then, what you want is
$$\frac{\partial f}{\partial a_\ell} = -2 \frac{\partial a_i}{\partial a_\ell} E[\mathbf{s}]_i + \frac{\partial a_i}{\partial a_\ell} a_i + a_i \frac{\partial a_i}{\partial a_\ell} = (-2 E[\mathbf{s}]_i + 2a_i )\delta_{i\ell} = -2E[\mathbf{s}]_\ell +2a_\ell$$.
where I used the fact that $\partial a_i/\partial a_i = \delta_{i\ell}$, the Kronecker delta.
So, the ith component of the vector $\partial f/\partial \mathbf{a}$ is
$$\frac{\partial f}{\partial a_i} = -2E[\mathbf{s}]_i +2a_i$$
which means
$$\frac{\partial f}{\partial \mathbf{a}} = - 2\mathbf{E}[\mathbf{s}] + 2\mathbf{a}$$.
(Since E is a vector that depends on the vector s, I have made E bold in vector notation). | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.969239354133606, "perplexity": 622.0881845900926}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-43/segments/1539583515088.88/warc/CC-MAIN-20181022134402-20181022155902-00393.warc.gz"} |
https://www.lacan.upc.edu/abstract/?id=576 | Abstract2018-05-24T12:52:58+00:00
### Subduction dynamics and the origin of Andean orogeny and Bolivian Orocline
Author (s): F. Capitanio, Faccena, C.; Zlotnik, S. and Stegman, D.
Journal: Nature
Volume: 480
Pages: 83 – 86
Date: 2011
Abstract:
The building of the Andes results from the subduction of the oceanic Nazca plate underneath the South American continent. However, how and why the Andes and their curvature, the Bolivian orocline, formed in the Cenozoic era (65.5?million years (Myr) ago to present), despite subduction continuing since the Mesozoic era (251.0–65.5?Myr ago), is still unknown. Three-dimensional numerical subduction models demonstrate that variations in slab thickness, arising from the Nazca plate’s age at the trench, produce a cordilleran morphology consistent with that observed. The age-dependent sinking of the slab in the mantle drives traction towards the trench at the base of the upper plate, causing it to thicken. Thus, subducting older Nazca plate below the Central Andes can explain the locally thickened crust and higher elevations. Here we demonstrate that resultant thickening of the South American plate modifies both shear force gradients and migration rates along the trench to produce a concave margin that matches the Bolivian orocline. Additionally, the varying forcing along the margin allows stress belts to form in the upper-plate interior, explaining the widening of the Central Andes and the different tectonic styles found on their margins, the Eastern and Western Cordilleras. The rise of the Central Andes and orocline formation are directly related to the local increase of Nazca plate age and an age distribution along the margin similar to that found today; the onset of these conditions only occurred in the Eocene epoch. This may explain the enigmatic delay of the Andean orogeny, that is, the formation of the modern Andes.
Bibtex:
```@article{
author={Capitanio, F. A.; Faccenna, C.; Zlotnik, S. and Stegman, D. R.},
title={Subduction dynamics and the origin of Andean orogeny and the Bolivian orocline},
journal={Nature},
volume={480},
pages={83-86},
year={2011},
issn={0028-0836},
doi={10.1038/nature10596},
url={http://dx.doi.org/10.1038/nature10596},
}
``` | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8221821188926697, "perplexity": 7874.529158382446}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2019-09/segments/1550249595829.93/warc/CC-MAIN-20190224044113-20190224070113-00061.warc.gz"} |
http://math.stackexchange.com/questions/405597/solve-system-of-equations-involving-cos-and-sin | # Solve system of equations involving cos and sin
I have come up with the following system, I want to solve it for $a$ and $c$:
$a \sin (x_0) - c \sin(x_0 - L) = 0\\ c \cos(x_0 - L) - a \cos(x_0) = 1$
In this system $x_0$ and $L$ are arbitrary.
p.s. why can't $L$ be $n\pi$?
-
so you want to solve it for a and c am I right? – iostream007 May 29 at 10:23
Yes, sorry forgot to mention it – user54297 May 29 at 10:25
I assume you are solving for $a$ and $c$. Then the solution may be written in matrix form as
\begin{align}\left ( \begin{array}\\a\\c\end{array}\right) &= \frac{1}{\sin{x_0} \cos{(x_0-L)} - \cos{x_0} \sin{(x_0-L)}} \left ( \begin{array}\\\cos{(x_0-L)} & \sin{(x_0-L)}\\\cos{x_0} & \sin{x_0}\end{array}\right)\left ( \begin{array}\\0\\1\end{array}\right) \\ &= \frac{1}{\sin{L}}\left ( \begin{array}\\\sin{(x_0-L)}\\\sin{x_0}\end{array}\right)\end{align}
Note that I used the sine addition formula to simplify the denominator term. This explains why $L \ne n \pi$: the denominator would be zero.
Then
$$a = \frac{\sin{(x_0-L)}}{\sin{L}}$$
$$c = \frac{\sin{x_0}}{\sin{L}}$$
-
$a \sin (x_0) - c \sin(x_0 - L) = 0\\ c \cos(x_0 - L) - a \cos(x_0) = 1$
from eqn (1)
$$a \sin (x_0) =c \sin(x_0 - L)\implies a=\dfrac {c \sin(x_0 - L)}{\sin (x_0)}$$
in eqn (2)
$$c \cos(x_0 - L) - \cos(x_0)\cdot\dfrac{c \sin(x_0 - L)}{\sin (x_0)} = 1$$ $$c[\cos(x_0 - L)\cdot\sin (x_0)-\sin(x_0 - L)\cdot\cos(x_0)]=\sin {(x_0)}$$ $$c[\sin (x_0-(x_0 - L))]=\sin {(x_0)}$$ $$c=\dfrac{\sin {(x_0)}}{\sin (L)}$$
Now $$a=\dfrac {c \sin(x_0 - L)}{\sin (x_0)}$$ $$a=\dfrac {\dfrac{\sin {(x_0)}}{\sin (L)}\cdot\sin(x_0 - L)}{\sin (x_0)}$$ $$a=\dfrac{\sin(x_0-L)}{\sin L}$$
-
Writing $P:= \sin x_0$, $Q := \sin(x_0-L)$, $R := \cos x_0$, $S := \cos(x_0-L)$, we solve this far-less-intimidating system ... \begin{align} \phantom{-}a P - c Q &= 0 \\ - a R + c S &= 1 \end{align} ... to get ... $$a = \frac{Q}{PS-QR} \qquad c = \frac{P}{PS-QR}$$
Then, we invoke trig's angle-difference formula to simplify: \begin{align} PS-QR &= \sin x_0 \cos(x_0-L)-\sin(x_0-L)\cos x_0 \\[4pt] &= \sin\left(x_0-(x_0-L)\right) \\[4pt] &= \sin L \end{align} so that $$a = \frac{\sin(x_0-L)}{\sin L} \qquad c = \frac{\sin x_0}{\sin L}$$ where $\sin L \neq 0$ (whence $L \neq n \pi$ for any $n$). | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 3, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 1.000009298324585, "perplexity": 1416.7162861958523}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-48/segments/1386163857566/warc/CC-MAIN-20131204133057-00004-ip-10-33-133-15.ec2.internal.warc.gz"} |
http://math.stackexchange.com/questions/301185/let-a-be-a-3-times-3-matrix-with-real-entries-such-that/301187 | # Let $A$ be a $3 \times 3$ matrix with real entries such that… [duplicate]
I came across the following problem that says:
Let $A$ be a $3 \times 3$ matrix with real entries.If $A$ commutes with all $3 \times 3$ matrices with real entries,then the number of distinct eigenvalues of $A$ is which of the following:
$0,1,2,3$ or none of these.
I do not know how to progress with this particular problem. Can someone point me in the right direction? Thanks in advance for your time.
EDIT: Even though the question has been asked few months ago and I got some nice explanations ,I revisited the problem and I am little confused about the conclusion of the problem. The scalar matrices of the form $\lambda I$ satisfies the property. So what should be the number of distinct eigenvalues? Here all eigenvalues will be $1$. So,what is the conclusion? Is the answer $1$ or $0$? Can someone comment on it?
-
## marked as duplicate by Marc van Leeuwen linear-algebra StackExchange.ready(function() { if (StackExchange.options.isMobile) return; $('.dupe-hammer-message-hover:not(.hover-bound)').each(function() { var$hover = $(this).addClass('hover-bound'),$msg = $hover.siblings('.dupe-hammer-message');$hover.hover( function() { $hover.showInfoMessage('', { messageElement:$msg.clone().show(), transient: false, position: { my: 'bottom left', at: 'top center', offsetTop: -7 }, dismissable: false }); }, function() { StackExchange.helpers.removeMessages(); } ); }); }); Feb 4 '15 at 8:22
If you want to go a little further, you could try to prove that the center of the algebra $L(E)$ (the linear operators on a $K$ vector space of any dimension), that is $\{u\in L(E)\,;\, uv=vu\forall v\in L(E)\}$, consists of the scalar operators $K\cdot \mbox{Id}_E$. The key point is that $u\in L(E)$ is scalar if and only if $u(x)$ and $x$ are linearly dependent for every $x\in E$. – 1015 Jun 28 '13 at 17:09
There is a known fact of group theory that says: $Z(GL_n)=\lambda I_n$, for all $\lambda\in\mathbb{R}$, being $Z(GL_n)$ the center of the group: the matrices that commute with every matrix of $GL_n$. I will set the guidelines for the demonstration:
Knowing the equivalence of these matrices with vector space endomorphisms, we take the homomorphism $f:\mathbb{R}^n\longrightarrow \mathbb{R}^n$, that has the matrix $A$ as the homomorphism matrix, being $A\in Z(GL_n)$.
We now show that $\lbrace x,f(x)\rbrace$ are linearly dependent: if they weren't, we could build a base of $\mathbb{R}^n$: $B=\lbrace v_1=x,v_2=f(x),v_3,v_4,...,v_n\rbrace$, for $n$ vectors, and there's only one homomorphism $g$ that swaps the first two vectors and keeps the rest the same: $$G=\left( \begin{array}{ccccc} 0 & 1 & 0 & \cdots & 0\\ 1 & 0 & 0 & \cdots & 0\\ 0 & 0 & 1 & \cdots & 0\\ \vdots & \vdots & \vdots & \ddots & \vdots\\ 0 & 0 & 0 & \cdots & 1 \end{array}\right)$$ It must be true that $AG=GA$, so $fg(v_1)=gf(v_1)\Rightarrow f(v_2)=g(v_2)=v_1=x$ which means that $ff(x)=x.$
Now we consider the homomorphism $H$: $$H=\left( \begin{array}{ccccc} 1 & 0 & 0 & \cdots & 0\\ 1 & 1 & 0 & \cdots & 0\\ 0 & 0 & 1 & \cdots & 0\\ \vdots & \vdots & \vdots & \ddots & \vdots\\ 0 & 0 & 0 & \cdots & 1 \end{array}\right)$$ This is also an isomorphism and $AH=HA$: $$fh(v_1)=f(v_1+v_2)=h(v_2)=v_2\Rightarrow v_2+f(v_2)=v_2\Rightarrow f(v_2)=0$$ We previously had that $x=ff(x)=f(v_2)$, so $x=0$, which is absurd because it was a vector of a minimal base, so our hypothesis was false, and $x, f(x)$ are linearly dependent. This means that $f(x)=\lambda(x)x$, with $\lambda$ a real function, that in the most general way, depends on $x$.
If $x$ and $y$ are linearly independent vectors, then we have that calling $z=x+y$: $$\lambda(z)x+\lambda(z)y=f(z)=f(x)+f(y)=\lambda(x)x+\lambda(y)y$$ This means that $$(\lambda(z)-\lambda(x))x+(\lambda(z)-\lambda(y))y=0$$ And $x,y$ are linearly independent, so: $$\lambda(z)=\lambda(x).$$ So if $x,y$ are linearly independent, $\lambda$ is not a function of the vector, but a constant.
If they're dependent, then we can do a similar trick: if they're dependent, then $y=xa$, for some real $a$: $$\lambda(y)y=f(y)=af(x)=a\lambda(x)x=\lambda(x)y.$$ If $y\not =0$, then $\lambda$ is constant too.
We have proved that for every vector: $Av=\lambda v$, for every $A\in Z(GL_n)$, so: $$A=\lambda\left( \begin{array}{ccccc} 1 & 0 & 0 & \cdots & 0\\ 0 & 1 & 0 & \cdots & 0\\ 0 & 0 & 1 & \cdots & 0\\ \vdots & \vdots & \vdots & \ddots & \vdots\\ 0 & 0 & 0 & \cdots & 1 \end{array}\right)$$
The converse is obvious: for every matrix of the form $\lambda I$, the matrix belongs to $Z(GL_n)$, then we have that if a matrix commutes with every other matrix, it has the form of the above, and those matrix have a unique eigenvalue: $\lambda$, which is a root of $n$ degree of its characteristic polynomial.
-
If $\mathrm A$ commutes with all matrices, then it commutes with this kind of matrix $$\mathrm E_{ij} = \text{ the matrix with only zeros but a 1 at line i, column j }$$
Check what it means for $\mathrm A$ to commute with $\mathrm E_{i,j}$.
-
Hint: The scalar matrices are precisely those that commute with all other square matrices of the same size.
-
Hint: The eigenvalues of $A$ come from its characteristic polynomial, which is a real polynomial with degree $3$. So it always have a real root and it has at most $3$ roots.
Do you agree?
-
Yes,that is true.But how should I use the fact that $A$ commutes with all $3 \times 3$ matrices with real entries? – learner Feb 12 '13 at 14:11
Let $A, B$ be 3×3 matrices with real entries and A commute with B,that is $AB=BA$. Let $\lambda$ be an eigenvalue of $A$. Then there exists a nonzero vector $v$ such that $$Av=\lambda v$$.
Now, we can have the following: $$BAv=B\lambda v$$ By commutativity of $A$ and $B$, we have $$(AB)v=\lambda Bv$$ $$\Rightarrow A(Bv)=\lambda (Bv)$$ $$\Rightarrow A=\lambda I$$ From this we can say that $A$ is a scalar matrix, which is a triangular matrix whose eigenvalue is $\lambda \in \mathbb{R}$.
-
(A-λI)(B v )= 0 does not imply A-λI=0. – Librecoin Feb 12 '13 at 18:40
If we Know the invertibility of $Bv$, I think it is immediate. Can it be invertible? – ftolessa Feb 13 '13 at 4:52
The vector B v need not be non-zero, since B may be singular. Even if it were non-zero, (A-λI)(B v )= 0 would still not imply A-λI=0. For example, if λ is an eigenvalue of a matrix A, then (A-λI) v = 0 has a non-zero solution v. – Librecoin Feb 13 '13 at 21:17
With $$A = \left[\begin{array}{ccc} \alpha_{1,1} & \alpha_{1,2} & \alpha_{1,3} \\ \alpha_{2,1} & \alpha_{2,2} & \alpha_{2,3} \\ \alpha_{3,1} & \alpha_{3,2} & \alpha_{3,3} \end{array}\right],\; B = \left[\begin{array}{ccc} \beta_{1,1} & \beta_{1,2} & \beta_{1,3} \\ \beta_{2,1} & \beta_{2,2} & \beta_{2,3} \\ \beta_{3,1} & \beta_{3,2} & \beta_{3,3} \end{array}\right]$$
Then $(AB)_{1,1} = \alpha_{1,1} \beta_{1,1} + \alpha_{1,2} \beta_{2,1} + \alpha_{1,3} \beta_{3,1}$.
But $(AB)_{1,1} = (BA)_{1,1} = \beta_{1,1} \alpha_{1,1} + \beta_{1,2} \alpha_{2,1} + \beta_{1,3} \alpha_{3,1}$.
Since $\beta_{i,j}$ can be anything, $\alpha_{1,2} = \alpha_{1,3} = \alpha_{2,1} = \alpha_{3,1} = 0.$
If you repeat that calulation for each cell of $(AB)_{i,j}$ then you get Tharsis's result that $A$ is a scalar matrix, i.e.: $A$ is already of the form $A = \lambda I$ where $I$ is the identity matrix. Eigenvalues of $A$ are those values $\mu$ which satisfy $$det(A - \mu I) = 0.$$ But $A = \lambda I$. So to get eigenvalues you have to solve $$det((\lambda - \mu) I) = 0,$$ i.e.: $$(\lambda - \mu)^3 det(I) = 0.$$ For any one particular $\lambda$ how many such $\mu$ can there be? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9685805439949036, "perplexity": 149.86985477840784}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-22/segments/1464051299749.12/warc/CC-MAIN-20160524005459-00035-ip-10-185-217-139.ec2.internal.warc.gz"} |
http://www.cs.nyu.edu/pipermail/fom/2013-February/017013.html | # [FOM] A proof that ZFC has no any omega-models
Joe Shipman JoeShipman at aol.com
Mon Feb 18 15:29:48 EST 2013
The difference is that we don't build L_\alpha but M_\alpha which uses a more restrictive set of operations; in particular, you don't necessarily get new sets at each level. Godel's construction makes sure each level of L properly extends the earlier ones, but this is not needed for M. Details are on pp. 104-105 of Cohen's book.
Solovay did not settle the question of whether ZFC proves the continuum does not have a total measure, he just showed that that is true iff ZFC disproves a measurable cardinal. And he did not need the existence of large cardinals to obtain this arithmetical result. Although not all arithmetical consequences of large cardinals follow from the consistency of the cardinals and don't require their actual existence, this particular arithmetical consequence (absence of a ZFC disproof of a total measure on the continuum) requires only consistency of the measurable cardinal.
My more general point is that assuming models exist satisfying large cardinal axioms involves a much more concrete type of statement than assuming the cardinals themselves exist (since such models may be considered objects in second-order arithmetic), and therefore is a more palatable assumption to those mathematicians who question the definiteness of statements involving actual large cardinals. I am not claiming that this would change mathematical practice significantly, I am just saying that we should not assume more than we need to.
-- JS
Sent from my iPhone
On Feb 16, 2013, at 8:11 PM, Monroe Eskew <meskew at math.uci.edu> wrote:
Mr. Shipman,
Can you explain your formulation of "V=M" a bit more? What is the inductive process, and what does it mean for it to terminate? For instance it does not take very long to close under rudimentary functions, but surely we don't stop there. It seems like the only way to make sense of the process of building L is by referring to ordinals. And then we might as well just use Solovay's formulation of what it means to be in M. Keep building L_\alpha along the ordinals until you reach a point where ZF is satisfied.
Regarding your view of large cardinals, consider the fact that there are many examples where ZFC does not prove some natural statement, but it is only through large cardinals that we can see this. For example, does the continuum carry a total measure extending Lebesgue measure? From Gödel (plus Kunen's inner model theory, I guess) we know ZFC does not prove that it does, so now we ask, does ZFC prove that the continuum does *not* carry a total measure? Solovay showed that forcing over a model of ZFC plus a measurable cardinal can produce a model where the continuum is an RVM cardinal.
Note that he answered a purely arithmetical question: Does ZFC prove the continuum does not have a total measure? If we agree that this was a valuable result even though it used a large cardinal assumption, I think we can agree that this is an illustration of the following general principle: The use of large cardinals in set theory is needed to answer many natural questions which are essentially arithmetical.
Now we turn to the question of whether to adopt your scheme of reducing large cardinal axioms to axioms expressing their arithmetical consequences. I ask, does this not look like insignificant philosophical window dressing? Once we agree that large cardinals should be used in set theory and their arithmetical consequences believed, what difference does it make whether we adopt, after the fact, a more modest ontological interpretation? Set theory would have to go on the same way as before to derive consistency results. The scheme you propose would have no mathematical import, and would just be akin to a footnote about a possible meta-level interpretation like we find in Kunen's wonderful book on set theory.
Best,
Monroe
On Feb 14, 2013, at 10:08 PM, Joe Shipman <JoeShipman at aol.com> wrote:
> Since I am the one who proposed "V=M", I can authoritatively say that Bob Solovay is correctly stating an equivalent version of it, although I prefer to follow Cohen's account, defining M in terms of operations to generate sets that are more restrictive than the operations used to build L. If that inductive process terminates, we get the minimal model, otherwise we get a proper class of "strongly constructible sets"; in that case the axiom says that all the sets that must exist are all the sets that there are.
>
> I am of course aware that this proposed new axiom is incompatible with the alternative proposal RVM that I have supported (which leads immediately to weak inaccessibles, and thus to M by taking L out to a weak inaccessible and then cutting down). I don't propose either axiom as being absolutely "true", but I think both are very useful in producing mathematics and either can be justified philosophically in a way that some would find compelling.
>
> I regard them as metaphysical poles: those who prefer the "definite", "intensional", ontologically minimal view of sets should be consistent and go all the way to V=M (not stop at V=L which makes the universe as narrow as possible but not as short as possible), while those who prefer the "combinatorial", "extensional", maximal picture should go at least as far as RVM (not stop at large cardinal axioms which make the universe taller but not as wide as possible).
>
> If I had to make a metaphysical commitment here, I would say that care about arithmetical statements much more than I care about statements about infinite sets, and I would consider replacing RVM with "all the arithmetical consequences of RVM are true", which is compatible with V=M because V=M has no new arithmetical consequences. I am currently inclining to the view that we have no way of gaining reliable knowledge about non-arithmetical axioms because of Skolem's paradox, but that we can feel confidence in their arithmetical consequences. I cannot think of any pair of axioms extending ZF which were both seriously proposed but which have incompatible arithmetical consequences. (That is, ZFC & X proves A, ZFC & Y proves ~A where A is arithmetical).
>
> Can anyone think of an example?
>
> We axiomatize the arithmetical consequences of RVM or any other set-theoretical statement S, in the language of arithmetic, with the axiom scheme
>
> If ZFC proves "S-->X_ZFC", then X
>
> as X ranges over statements of arithmetic and X_ZFC is a standard coding of X in the language of set theory.
>
> Can anyone think of an example where a set theory's arithmetical consequences were axiomatized in the language of arithmetic in a better way than I just described, (i.e. in a way that did not require arithmetization of provability)?
>
> -- JS
>
>
> Sent from my iPhone
>
> On Feb 14, 2013, at 2:00 AM, Robert Solovay <solovay at gmail.com> wrote:
>
>
> First, I believe, (but perhaps my memory is misleading me) that Joe
> Shipman has previously advocated the axiom that the continuum is
> real-valued measurable. It seems worth remarking that this latter
> axiom implies that "Zero sharp" exists, and a fortiori that M exists
> and is countable.
>
> Second, what I would mean by "V=M" is precisely what Mr. Eskew
> formulates; The conjunction of V=L and the assertion that for no
> ordinal alpha is L_alpha a model of ZFC. I am puzzled as to what I
> have said that could make Eskew think I have some different
> formulation in mind.
>
> Finally, it seems to me that Mr. Koskensilta conflates the following
> two propositions:
>
> (A) ZFC is arithmetically sound.
>
> (B) ZFC has an omega model.
>
> While, of course, in ZFC, (A) follows from (B), the converse does not hold.
>
> One way to see this is to note that in ZFC + (B) one can easily prove
> that "ZFC + (A)" is consistent. Of course, by Godel's second
> incompleteness theorem, ZFC + (A) is unable to prove this. So ZFC can
> not prove "(A) implies (B)".
>
> Of course, the results of this discussion can not be wholly carried
> out in ZFC (which cannot even prove that ZFC is consistent.) But the
> slightly stronger theory "ZFC = (B)" is perfectly adequate to carry
> out the arguments I have sketched.
>
> -- Bob Solovay
> _______________________________________________
> FOM mailing list
> FOM at cs.nyu.edu
> http://www.cs.nyu.edu/mailman/listinfo/fom
> _______________________________________________
> FOM mailing list
> FOM at cs.nyu.edu
> http://www.cs.nyu.edu/mailman/listinfo/fom
_______________________________________________
FOM mailing list
FOM at cs.nyu.edu
http://www.cs.nyu.edu/mailman/listinfo/fom | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9384744763374329, "perplexity": 871.5490177661319}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-52/segments/1418802767453.104/warc/CC-MAIN-20141217075247-00107-ip-10-231-17-201.ec2.internal.warc.gz"} |
http://m-phi.blogspot.com/2013/01/other-formulations-of-quine-putnam.html | ## Sunday, 20 January 2013
### Other Formulations of the Quine-Putnam Indispensability Argument
In the previous post, I formulated the Quine-Putnam Indispensability argument as follows.
The Quine-Putnam Indispensability Argument (JK)
(1) Mathematicized theories are inconsistent with nominalism.
(2) Our best scientific theories are mathematicized.
(C) So, if one accepts our best scientific theories, one must reject nominalism.
I believe that this formulation is quite faithful to the intentions of Quine and Putnam, as well as to the intentions those of those involved in the early phase of the debate: Field, Burgess, Shapiro, Chihara and Hellman.
In contrast, here is Mark Colyvan's much more recent formulation of the argument (from his Stanford Encyclopedia entry, "Indispensability Arguments in the Philosophy of Mathematics"):
The Quine-Putnam Indispensability Argument (MC):
(P1) We ought to have ontological commitment to all and only the entities that are indispensable to our best scientific theories.
(P2) Mathematical entities are indispensable to our best scientific theories.
(C) We ought to have ontological commitment to mathematical entities.
This kind of formulation has become quite widely cited. But I think it is mistaken as a formulation of what Quine and Putnam had in mind. Here are the reasons.
First, Quine and Putnam were not primarily advocating a view about what "we ought to have ontological commitment to". For Quine and Putnam, ontological commitment is a semantic property of sentences and theories, not a normative epistemic property of human beings. Whether a theory $T$ implies that there are $F$s can be established by regimenting this theory into some precise canonical notation, as $T^{\ast}$, say. And seeing if, thus regimented, $T^{\ast}$ logically implies $\exists x Fx$. Whether one "accepts" this theory or not is immaterial, as Quine emphasized in 1948. Admittedly, Quine and Putnam do sometimes talk loosely, about "accepting abstract entities into our ontology", but that really is loose talk, elliptical for "accepting some theory which implies that there are abstract entities". Here, acceptance of the theory is an epistemic matter, separable from the semantic matter, concerning which sentences of the form $\exists x Fx$ the theory implies.
Second, the notion of "we" (i.e., human cognition) having "ontological commitment" to an entity is problematic. All parties to the debate up to, say, the mid-1990s took the notion of ontological commitment to involve a property of sentences and theories; we may accept, or may not accept, sentences and theories (representations, if you prefer; or even propositions, if you prefer). Those sentences, theories, etc., may, or may not, imply that there are $F$s. The notion of cognition bearing "ontological commitment" to an entity is a bit mysterious to me. Is the relation semantical? All knowledge of the world is mediated by cognitive representations, and the whole idea of direct contact with objects is something I'm a rather sceptical about. (In other words, I am defending Lockean indirect realism.)
Third, there is an epistemological side of things, for Quine and Putnam. This comes from a background acceptance of science. For both, we are to accept science roughly as is. Quine's long-held view might be called a kind of realistic pragmatism; and Putnam's view (as of 1971, Philosophy of Logic, and 1975, "What is Mathematical Truth?"), was classic scientific realism. As philosophers, we then subject science---that we have already accepted---to analysis. This position is defended by Russell too, in his 1950 article "Logical Positivism":
For my part, I assume that science is broadly speaking true, and arrive at the necessary postulates by analysis. But against the thoroughgoing sceptic I can advance no argument except that I do not believe him to be sincere. (Russell, 1950)
Both Quine and Putnam reject a certain kind of First Philosophy. They are not arguing from the perspective of the armchair First Philosopher or Cartesian, who has purged her mind of all "commitments" and who is wondering what to "accept" from a baseline of noble ontological innocence. On the contrary, one already accepts science, as is. One is subjecting science itself to analysis.
Finally, it seems misleading to me to say that the Quine-Putnam indispensability argument is meant to provide reasons for accepting the existence of mathematical entities. Rather, it argues that our working scientific theories presuppose the existence of mathematical entities, and are the best theories around. Consequently, we are being "intellectually dishonest" if we accept science, while feigning to reject those entities. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6326412558555603, "perplexity": 2628.6044287172645}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-13/segments/1490218186895.51/warc/CC-MAIN-20170322212946-00071-ip-10-233-31-227.ec2.internal.warc.gz"} |
https://puzzling.stackexchange.com/questions/91026/longest-word-worth-at-most-a-million/91030 | # Longest word worth at most a million
An old and popular puzzle, recently revived on Twitter by Alex Bellos, Chris Smith, and others, asks to take the first 26 primes, relate each to letters of the alphabet (A = 2, B = 3, C = 5, ..., Y = 97, Z = 101), and use this code to find the (legitimate) English word that comes closest to a million, where the word's numeric value is given by the product of its letters. CAB is thus valued 5x2x3=30.
With the same code, what is the longest English word valued at most a million?
• Well, an upper bound is $19$ letters as $2^{19} = 524288$. – Jens Nov 10 '19 at 2:30
• might be useful: answers.com/Q/… – JMP Nov 10 '19 at 3:04
• What counts as an English word, exactly? – Deusovi Nov 10 '19 at 3:06
• @Deusovi Say a word admissible to Scrabble players. – Bernardo Recamán Santos Nov 10 '19 at 3:09
• Vaguely similar to this one I asked – smci Nov 11 '19 at 6:29
Closest to one million:
COLIC = 999925
This is the sixth-largest number less than or equal to one million with no prime factors greater than 101.
As for longer words:
Without much effort, I have found several seven-letter words with values less than one million. In particular, the least among them is CABBAGE = 33660. I expect their is some eight-letter word to be found.
• I came to the same result. – Alexander Geldhof Nov 10 '19 at 18:53
Using the scrabble dictionary, and a short python program:
Several 8-letter words, I think the best one is
CABBAGED: 235620 "To steal, pilfer"
But the 8-letter one closest to 1,000,000 is:
ANABAENA: 976272 "A genus of filamentous cyanobacteria that exist as plankton"
Other 8-letter words: cabbalah: 253080, cabbalas: 892440, dahabeah: 667128.
• Note that 'closest to one million' and 'longest not more than one million' were two separate queries – Daniel Mathias Nov 10 '19 at 4:25
• @Daniel Mathias Ah, the "closest to one million" means of the 8-letter words. Edited answer for clarity. – IronEagle Nov 10 '19 at 4:28
• Can you please share the Python code? – user62885 Nov 11 '19 at 0:27
• Uhr... I thought the solution was the old smiles joke, with two s's removed... – WhatsUp Nov 11 '19 at 1:03
• @Nyssa Essentially the same as CDJB's answer. – IronEagle Nov 11 '19 at 19:15
I used an english wordlist from here, and a short python program to yield:
Longest possible word under 10**6:
calabaza (8 characters) - 896880
Closest to 10**6:
colic - 999925
Code used:
import numpy as np
SCORER = {'a': 2,
'b': 3,
'c': 5,
'd': 7,
'e': 11,
'f': 13,
'g': 17,
'h': 19,
'i': 23,
'j': 29,
'k': 31,
'l': 37,
'm': 41,
'n': 43,
'o': 47,
'p': 53,
'q': 59,
'r': 61,
's': 67,
't': 71,
'u': 73,
'v': 79,
'w': 83,
'x': 89,
'y': 97,
'z': 101}
with open('words_alpha.txt') as word_file:
return valid_words
def getScore(word):
return np.prod([SCORER[char] for char in word], dtype=np.uint64)
longest = ''
closest = ('', 0)
for word in english_words:
score = getScore(word)
if score < 10**6:
if len(word) > len(longest):
longest = word
if 10**6 - closest[1] > 10**6 - score:
closest = (word, score)
print(longest, getScore(longest))
print(closest)
To get the ball rolling, I've got
CABBAGE
Length: 7
Value: 33,660
Note: this does not answer the question asked; it answers the question of finding the best possible value at most a million, not the longest length.
Here's a Mathematica notebook (via Wolfram Programming Lab) that I used to check for better solutions: https://www.wolframcloud.com/obj/solly.ucko/Published/Longest_word_worth_at_most_a_million.nb
In[1]:= letterMapping = AssociationThread[Prime[Range[26]], Alphabet[ ]]
Out[1]= <|2 → a, 3 → b, 5 → c, 7 → d, 11 → e, 13 → f, 17 → g, 19 → h,
23 → i, 29 → j, 31 → k, 37 → l, 41 → m, 43 → n, 47 → o, 53 → p, 59 → q,
61 → r, 67 → s, 71 → t, 73 → u, 79 → v, 83 → w, 89 → x, 97 → y, 101 → z|>
In[2]:= factorList[n_] := Flatten[Map[Apply[ConstantArray], FactorInteger[n], 1]]
In[3]:= f[n_] := Map[letterMapping, factorList[n]]
In[4]:= factorList[1 000 000]
Out[4]= {2, 2, 2, 2, 2, 2, 5, 5, 5, 5, 5, 5}
In[5]:= Select[Table[f[n], {n, 1 000 000, 1 000 000 - 75, -1}], Not@* AnyTrue[MissingQ]]
Out[5]= { {a, a, a, a, a, a, c, c, c, c, c, c}, {b, b, b, d, e, f, l},
{f, f, r, y}, {j, j, j, m}, {a, a, a, a, a, a, a, a, a, b, b, d, k}, {c, c, i, l, o} }
So unless a permutation of {a, a, a, a, a, a, c, c, c, c, c, c}, {b, b, b, d, e, f, l}, {f, f, r, y}, {j, j, j, m}, or {a, a, a, a, a, a, a, a, a, b, b, d, k} is a valid word (unlikely), Daniel Mathias's answer of
COLIC
is optimal.
• @JiK Oh, oops... I'll work on fixing it at some point if/when I get a chance. – Solomon Ucko Nov 11 '19 at 14:10
I wrote a program to check a list of words from
ANABAENA,
which others have found, here are the words of each length with the lowest scores:
A (2) AA (4) ABA or BAA (12) ABBA or BABA (36) ABACA (120) BACCAE (3 300) CABBALA (13 320) CABBAGED (235 620) ABDICABLE (11 794 860) DEADHEADED (242 875 556) ABRACADABRA (37 507 680) ABRACADABRAS (2 513 014 560)
No words over 12 letters long are listed, possibly at least in part because a Scrabble board is 15x15.
Interestingly, there is an 11-length word with a lower score than any 10-length word. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.2684798538684845, "perplexity": 5541.901160058654}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 5, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2020-16/segments/1585371886991.92/warc/CC-MAIN-20200410043735-20200410074235-00032.warc.gz"} |
https://okayama.pure.elsevier.com/en/publications/measurement-of-neutrino-oscillation-parameters-from-muon-neutrino-2 | # Measurement of neutrino oscillation parameters from muon neutrino disappearance with an off-axis beam
T2K Collaboration
Research output: Contribution to journalArticlepeer-review
78 Citations (Scopus)
## Abstract
The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01 × 1020 protons on target. In the absence of neutrino oscillations, 205 ± 17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin223) = 0.514 ± 0.082 and mass splitting |Δm232| = 2.44+0.17-0.15 × 10-3 eV2/c4. Our result corresponds to the maximal oscillation disappearance probability.
Original language English 211803 Physical Review Letters 111 21 https://doi.org/10.1103/PhysRevLett.111.211803 Published - Nov 19 2013
## ASJC Scopus subject areas
• Physics and Astronomy(all)
## Fingerprint
Dive into the research topics of 'Measurement of neutrino oscillation parameters from muon neutrino disappearance with an off-axis beam'. Together they form a unique fingerprint. | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.987936794757843, "perplexity": 4336.732573790376}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2022-05/segments/1642320299927.25/warc/CC-MAIN-20220129032406-20220129062406-00481.warc.gz"} |
https://link.springer.com/article/10.1007%2Fs10979-006-9016-1 | Law and Human Behavior
, Volume 31, Issue 1, pp 109–115
# On Lie Detection “Wizards”
Article
M. O’Sullivan and P. Ekman (2004) claim to have discovered 29 wizards of deception detection. The present commentary offers a statistical critique of the evidence for this claim. Analyses reveal that chance can explain results that the authors attribute to wizardry. Thus, by the usual statistical logic of psychological research, O’Sullivan and Ekman's claims about wizardry are gratuitous. Even so, there may be individuals whose wizardry remains to be uncovered. Thus, the commentary outlines forms of evidence that are (and are not) capable of diagnosing lie detection wizardry.
### KEY WORDS
deception detection
Legal professionals have an interest in deception. Many of them believe that deception is common. Many of them have views about their own ability to detect deceit.
Psychologists have been writing about deception for decades. They base their writings on psychological research. Hundreds of relevant research studies have been conducted over the years, and these have been summarized in a recent review (Bond & DePaulo, in press). The accumulated research literature suggests that people are not good at detecting deception. In judging whether or not others are lying, the average person is accurate roughly 54% of the time when 50% would be expected by chance.
Deception researchers have studied topics of forensic interest. Some have documented the lie detection abilities of relevant occupational groups (Meissner & Kassin, 2002). Others have attempted to develop lie detection training procedures that would be of use in forensic settings (Kassin & Fong, 1999). Many have focused their research efforts on the sorts of high-stakes lies that would be of interest in the legal arena (Garrido, Masip, & Herrero, 2002). For book-long treatments of these and other forensic aspects of deception, see Vrij (2001) as well as Granhag and Stromwall (2004).
O’Sullivan and Ekman (2004) have recently reported a curious result. They found 29 “wizards” of deception detection. Interviews reveal that these “geniuses” of lie detection have “an intense focus and investment in their performance” (O’Sullivan, 2005, p. 246).
Lie detection wizards should be of interest to forensic researchers. It would be smart for researchers to scrutinize wizards’ occupational backgrounds, to see if legal professionals are overrepresented. Those who are attempting to develop lie detection training procedures should wish to uncover wizards’ detection strategies. All forensic researchers should be interested in wizards who have demonstrated an ability to detect high-stakes lies, and this is precisely the ability claimed for these 29 wizards (O’Sullivan & Ekman, 2004). Some of the lies they detected were told under threats of punishment. On the more practical side, law enforcement agencies would be wise to hire lie detection wizards. The US government should also want to hire them. Recognizing this latter point, O’Sullivan and Ekman (2004) have already “suggested to government officials that wizards … might be consulted on cases of extraordinary importance” (p. 284).
Before concluding that these 29 individuals have extraordinary abilities, let us scrutinize the statistical evidence for wizardry at lie detection. In this commentary, we show that a simple chance mechanism could produce the wizard-like performances O’Sullivan and Ekman observed. We also describe the forms of evidence that would be needed to determine whether or not people are lie detection wizards.
## “WIZARDS” OF LIE DETECTION
O’Sullivan and Ekman (2004) found 29 individuals who performed well on three high-stakes lie detection tests. Test 1 involves lies about opinions; test 2 involves lies about a mock crime; and test 3 involves lies about emotion. These tests are in a videotaped format. Ten people appear on each tape—five who are lying and five who are telling the truth. Test-takers see each person on each tape. In response to each videotape segment, test-takers indicate whether or not the person on the tape is lying.
Results on the opinion, crime, and emotion tests have appeared in seven journal articles (Ekman & O’Sullivan, 1991; Ekman, O’Sullivan, & Frank, 1999; Etcoff, Ekman, Magee, & Frank, 2000; Frank & Ekman, 1997; Frank, Paolantonio, Feeley, & Servoss, 2004; O’Sullivan, 2003; O’Sullivan, Ekman, & Friesen, 1988). Let us summarize the findings presented in those professional outlets while confining our attention to test results for college students. Accuracy rates on the opinion, crime, and the emotion test are available for 353, 113, and 464 undergraduates who judged those tapes. On the average, these students correctly judged 56.06, 60.19, and 50.00% of the opinion, crime, and emotion segments.
O’Sullivan and Ekman have screened over 12,000 professionals for their expertise at lie catching. Twenty-nine of the 12,000 met the researchers’ criteria for wizardry. To convince readers of the genius displayed by these individuals, O’Sullivan and Ekman report a statistical computation. It shows that there is an extremely low probability that any given person would achieve a “wizard” performance by chance. For purposes of the computation, the researchers define a “chance” performance as one in which a test-taker responds to video segments as though s/he were flipping coins—thus having a 50/50 chance of being correct on each of 30 lie-or-truth segments.
We have several statistical concerns about this work. Let us begin by noting that people do not respond to the crime and opinion video segments as though they were flipping coins. They judge more than 50% of these lies and truths correctly, as journal articles report. Also, O’Sullivan and Ekman (2004) report the probability of one individual achieving a wizard-qualifying test score, even though more than 12,000 individuals have been tested. Although the probability of any one person excelling at these tests is low, it may nonetheless be quite likely that one (or more) of 12,000 test-takers would achieve a high score (cf., Nickerson & Hammond, 1993). An appropriate model for these data would need to acknowledge the large number of people who have taken the tests.
Here we consider the possibility that none of the 12,000 test-takers were wizards. Under this null hypothesis, we compute the probability that 29 (or more) of the test-takers would meet the criteria O’Sullivan and Ekman have used to identify wizards. We determine this probability under two statistical models: a coin-flipping model and a research-based model. We regard the first model as inappropriate and are presenting it only because it formalizes an assumption made by O’Sullivan and Ekman. We regard the second model as more realistic.
Let us explain these two models. The coin-flipping model begins with an assumption that is false, according to earlier research—that people have a 50/50 chance of being accurate on each video segment of each test O’Sullivan and Ekman use to identify wizards. It assumes that 50% of nonwizards would judge the average lie accurately, when more than 50% have judged it accurately in prior research. Because the model assumes that fewer nonwizards would make correct judgments than the number who would actually make them, it should lead to an underestimate of the number of “wizards” on these tests. Anyone who gets substantially more than 50% right will be labeled a “wizard.” But the average judge gets more than 50% right, as previous research shows.
The research-based model uses results from earlier student judges to estimate a chance level of accuracy on each segment. If (despite Meissner & Kassin, 2002), we entertain the possibility that students are less accurate on these lie detection tests than professionals, this model may also be conservative. Even so, the research-based model for predicting professionals’ lie detection accuracy is more realistic than the coin-flipping model. Hence, it will be interesting to compare the number of “wizards” O’Sullivan and Ekman found with a research-based prediction for the number of wizards.
Let us now offer a few statistical details. By the O’Sullivan and Ekman (2004) definition, a person is a “wizard at deception detection” if the person
1. (a)
reports correct judgments to at least nine opinion video segments, and gives correct judgments to either
2. (b)
at least eight crime video segments or
3. (c)
at least eight emotion video segments.
We begin with the simplifying assumption that all of the video segments on a given lie detection test are equally difficult. Given our simplifying assumption, we use the binomial distribution to determine the probability of a performance on each test that satisfies the cutoff score prescribed by the authors.
Let us symbolize the probability of such a performance as x for the opinion test, y for the crime test, and z for the emotion test. Then for reasons that are explained by Howell (2002), the overall probability of a person meeting the O’Sullivan and Ekman criterion for wizardry can be determined from the equation $$x\left( {y + z - yz} \right)$$. Let us symbolize this overall probability as p. If 12,000 randomly selected nonwizards took these tests, we would expect 12,000 × p of those individuals to be classified as wizards.
Let us now present some of the numerical results from two statistical models: the coin-flipping model and the research-based model. Under the coin-flipping model, x = .0114, y = .0553, and z = .0553. These figures imply that p = .00122. Thus, we would expect 14.71 of the 12,000 test-takers to meet the O’Sullivan and Ekman criterion for being a wizard. Under the research-based model, x = .0270, y = .1701, and z = .0553. This model implies that p = .00583. Thus if we use results from earlier student judges, we would expect 69.98 of the 12,000 individuals to meet the criterion for being a wizard.
O’Sullivan and Ekman tested 12,000 individuals for wizardry. They classified 29 of those 12,000 as wizards (95% confidence interval = 18.46–39.54 wizards). O’Sullivan and Ekman found more wizards than would be expected under the coin-flipping model. In our way of thinking, this discrepancy verifies what was already known—that people do not respond to these video segments as though they were flipping coins. The coin-flipping model classifies anyone who achieves substantially more than 50% accuracy on these deception tests as a wizard. But the average student achieves more than 50% accuracy. That is why more people are classified as “wizards” than the coin-flipping model predicted.
O’Sullivan and Ekman classified only 29 professionals as wizards. This is fewer than the 70 wizards our research-based model would seem to predict. This discrepancy is not easy to explain. One possible explanation relates to a detail of our research-based model—its use of only student judges to predict lie detection accuracy. In addition to the 930 students who judged the three relevant videotapes, 508 other people had judged these tapes before the wizards made any judgments. Suppose we constructed a research-based model from the accuracy of all 1438 judges of these videotapes. Although one might expect this more inclusive research-based model to yield more accurate predictions, it in fact predicts that 155 of the 12,000 professionals should be classified as wizards. Thus, it does nothing to explain why only 29 “wizards” were found.
Although we cannot be sure why the observed number of wizards is so much lower than our research-based prediction, let us venture two possible explanations: one is methodological, the other statistical. The methodological explanation is that these 12,000 professionals took lie detection tests under different conditions than earlier judges. For example, the professionals took two of the tests in their private residences; whereas, the earlier judges took those tests in an academic group setting. Perhaps the professionals were tested under conditions less conductive to lie detection.
The second, statistical explanation begins by noting that only a subset of the 12,000 professionals studied by O’Sullivan and Ekman took all three lie/truth discrimination tests. Let us elaborate on the researchers’ testing protocol. The 12,000 professionals in this study attended group workshops on detecting deception. At the outset of each workshop, participants judged 10 opinion lie-or-truth segments. After completing this opinion test, participants were given the correct answers “and asked to report to the group (by a show of hands) how many items they got right” (O’Sullivan & Ekman, 2004). Workshop participants who reported scoring 90% or better were invited to take additional tests. Some accepted the invitation and subsequently completed the crime and emotion tests.
We do not know how many professionals completed the three-test lie detection battery, but if we are allowed a post hoc assumption about that number, we can fit the research-based model to these data perfectly. To do so, we note that under the research-based model there is a .00583 probability of a nonwizard being classified as a wizard. Thus, the assumption that we must make is that N people took all three lie detection tests, where N can be found from the equation 29 = .00583 N. Algebra then reveals that to “predict” 29 wizards, we must assume that 5,390 of the 12,000 professionals completed all three lie detection tests. Perhaps it is implausible to assume that 5,390 of 12,000 professionals completed all three of the researchers’ lie detection tests. Readers need to make this judgment for themselves, after studying the article by O’Sullivan and Ekman (2004).1
## DIAGNOSTIC EVIDENCE
As statisticians, we are in no position to conclude that the 29 individuals whom O’Sullivan regards as lie detection wizards are not, in fact, wizards. Following standard null hypothesis logic, failures to find significant evidence may represent Type II errors. Thus, the current evidence may simply be insufficient to uncover these 29 individuals’ wizardry. Indeed, it is conceivable that many more of the 12,000 professionals in question are wizards, and the authors’ procedures lack sufficient power to detect this fact. In light of this logical possibility, it is important to consider the forms of evidence that could (and could not) diagnose lie detection wizardry.
To be diagnostic, tests for wizardry must meet certain psychometric and statistical criteria. The tests must be internally consistent. Because the tests must show high composite reliability, they may need to be long (Nunnally, 1978). An a priori statistical definition of wizardry needs to be specified. Computations must demonstrate that the cutoff score to be used for identifying wizards has sufficient statistical power to detect this statistically defined “wizard.” This cutoff score should take into account probabilistic arguments of the sort we have outlined above. Evidence of an extra-chance detection performance should be required before any wizardry is inferred. A second, lower cutoff score should also be developed for the identification of nonwizards.
Of course, there are other considerations in testing. If a lie detection test is to be diagnostic of a general forensic ability, it should expose test-takers to a variety of forensically relevant lies. There would be advantages if the person who developed this test was not the person who interpreted the test. If the test developer and interpreter had different theoretical orientations, it would be hard to contend that the content of the test and the interpretation of the test were related to one another in a way that reflected “bias” (Rosenthal, 1994).
Standardized testing procedures should be used. No one should be allowed to score their own test of lie detection ability, nor should anyone's report of their score on a test be uncritically accepted. Tests should be supervised and scored by a third party, ideally an individual who does not know the correct answers to test items. The supervisor should have no preexisting belief about the ability level of any particular test-taker. The absence of any preexisting supervisor assumptions would be most critical if the testing format were interactive—say, if the test required the supervisor to interview subjects. If the intended interpretation is that a test measures a preexisting ability, test-takers should get no preexposure to the sorts of items that appear on the test—other than an orienting instructional item or two.
## CONCLUSION
Convincing evidence of lie detection wizardry has never been presented. In fact, no truly diagnostic procedure for identifying wizards has ever been reported. Thus, it is premature for government officials to rely on any “wizards” of lie detection in cases of extraordinary importance. It is likewise premature for forensic psychologists to base their research on the assumption that lie detection wizards do (or do not) exist. Rather than constructing research programs on any such assumption, forensic psychologists would be better advised to spend their time developing procedures that could in principle distinguish lie detection wizards from nonwizards.
1
## Footnotes
1. 1.
It is under the model based on student judges’ lie detection accuracy that we must make the assumption outlined in the text. Under the model based on the accuracy of all earlier judges, we “predict” 29 wizards by assuming that 2,248 of the 12,000 professionals completed all of the lie detection tests. An alternative statistical analysis would treat as unknown the number of professionals who were invited to take all of the lie detection tests. Then it would use the chance probability of wizard-qualifying performances on the latter two tests to induce the number of professionals who in fact completed the test battery. Applying this alternative treatment in the context of the student judge research-based model, we “predict” 29 wizards if 114 of the 12,000 professionals completed all three tests. Obviously, our two statistical analyses yield different inferences. We ourselves regard the second analysis as more defensible—given that participants were (or were not) invited to complete the test battery based on their self-reports of a test outcome.
### REFERENCES
1. Bond, C. F., Jr., & DePaulo, B. M. (in press). Accuracy of deception judgments. Personality and Social Psychology Review.Google Scholar
2. Ekman, P., & O’Sullivan, M. (1991). Who can catch a liar? American Psychologist, 46, 913–920.
3. Ekman, P., O’Sullivan, M., & Frank, M. G. (1999). A few can catch a liar. Psychological Science, 10, 263–266.
4. Etcoff, N., Ekman, P., Magee, J. J., & Frank, M. G. (2000). Lie detection and language comprehension. Nature, 405, 139.
5. Frank, M. G., & Ekman, P. (1997). The ability to detect deception generalizes across different types of high-stakes lies. Journal of Personality and Social Psychology, 72, 1429–1439.
6. Frank, M. G., Paolantonio, N., Feeley, T. H., & Servoss, T. J. (2004). Individual and small group accuracy in judging truthful and deceptive communication. Group Decision and Negotiation, 13, 45–59.
7. Garrido, E., Masip, J., & Herrero, C. (2002). Police officers’ credibility judgments: Accuracy and estimated ability. International Journal of Psychology, 39, 276–289.Google Scholar
8. Granhag, P. A., & Stromwall, L. A. (2004). Deception detection in forensic contexts. Cambridge, England: Cambridge University Press.Google Scholar
9. Howell, D. C. (2002). Statistical methods for psychology (5th ed.). Pacific Grove, CA: Duxbury Press.Google Scholar
10. Kassin, S. M., & Fong, C. T. (1999). “I’m innocent!”: Effects of training on judgments of truth and deception in the interrogation room. Law and Human Behavior, 23, 499–516.
11. Meissner, C. A., & Kassin, S. M. (2002). “He's guilty:” Investigator bias and judgments of truth and deception. Law and Human Behavior, 26, 469–480.
12. Nickerson, C. A. E., & Hammond, K. R. (1993). Comment on Ekman and O’Sullivan. American Psychologist, 48, 989.
13. Nunnally, J. C. (1978). Psychometric theory (2nd ed.). New York: McGraw Hill.Google Scholar
14. O’Sullivan, M. (2003). The fundamental attribution error in detecting deception: The boy-who-cried-wolf effect. Personality and Social Psychology Bulletin, 29, 1316–1327.
15. O’Sullivan, M. (2005). Emotional intelligence and deception detection: Why most people can't ‘read’ others, but a few can. In R. E. Riggio & R. S. Feldman (Eds.), Applications of nonverbal communication (pp. 215–253). Mahwah, NJ: Erlbaum.Google Scholar
16. O’Sullivan, M., & Ekman, P. (2004). The wizards of deception detection. In P. A. Granhag & L. A. Stromwall (Eds.), Deception detection in forensic contexts (pp. 269–286). Cambridge, UK: Cambridge Press.Google Scholar
17. O’Sullivan, M., Ekman, P., & Friesen, W. V. (1988). The effect of comparisons on detecting deceit. Journal of Nonverbal Behavior.Google Scholar
18. Rosenthal, R. (1994). On being one's own case study: Experimenter effects in behavioral research—30 years later. In W. Shadish & S. Fuller (Eds.), The social psychology of science (pp. 214–229). New York: Guilford Press.Google Scholar
19. Vrij, A. (2001). Detecting lies and deceit: The psychology of lying and the implications for professional practice. New York: Wiley.Google Scholar | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.630753219127655, "perplexity": 3279.811765639904}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-43/segments/1508187824820.28/warc/CC-MAIN-20171021152723-20171021172723-00404.warc.gz"} |
http://mathhelpforum.com/calculus/7553-related-rates.html | # Math Help - Related Rates!
1. ## Related Rates!
Suppose that the price p (in dollars) and the weekly sales x (in thousands of units) of a certain commodity satisfy the demand equation 2p^3 + x^2 = 4500.
Determine the rate at which sales are changing at a time when x = 50, p = 10, and the price is falling at the rate of \$0.50 per week. (Thanks in advance!)
2. Differentiate your equation, sub in what you are given and find dx/dt.
$6p^{2}\frac{dp}{dt}+2x\frac{dx}{dt}=0$ | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 1, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6694103479385376, "perplexity": 984.2893980159575}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-35/segments/1408500832155.37/warc/CC-MAIN-20140820021352-00057-ip-10-180-136-8.ec2.internal.warc.gz"} |
http://mathoverflow.net/questions/2129/lower-bound-on-volume-of-minimal-hypersurface-contained-in-a-unit-ball-with-curva/2686 | # Lower bound on volume of minimal hypersurface contained in a unit ball with curvature bounds
I was just wondering, if I have a geodesic ball of radius one in a manifold M whose sectional curvature lies between -epsilon and epsilon for epsilon small, and the injectivity radius of my manifold is two say, and I have a SINGULAR minimal hypersurface in M passing through the centre of my unit ball, can I find a lower bound, away from zero, on the volume of the singular minimal hypersurface contained in the ball, in terms of only the dimension of the ambient manifold M? Thanks!
-
I know nothing about this stuff. Is such a bound already known if M is flat? – Deane Yang Oct 26 '09 at 14:10
## 1 Answer
@Deane, when M is Euclidean space, this is a consequence of monotonicity, which is one of the most fundamental facts about minimal surfaces.
As for the original question, I believe that the answer is YES if the hypersurface S is minimizing in M. Think of S as sitting in the Euclidean ball determined by geodesic coordinates. Of course, S is no longer minimizing in the Euclidean ball, but the curvature bounds should give you control on the ratio of areas computed wrt to the ambient metric vs areas computed wrt the Euclidean metric. So although any "competitor" surface can have Euclidean area less than that of S, it must have area greater than |S|/C for some big constant C. Using a modification of the standard monotonicity argument, this is sufficient to derive a lower bound on the area of S. (For this part, consult arxiv 0705.1128 Section 5 for details.)
As for when S is not necessarily minimizing, I suspect(?) that the answer is still yes. One idea is to look at the proof of Allard's monotonicity formula and account for what happens in the presence of curvature.
I also suspect that all of this is written up in full generality and rigor... somewhere.
-
Maybe you could ask Rick Schoen the next time you see him? (I live 3 blocks from the Columbia math department, where Rick is visiting, but I just don't have any time to hang out there) – Deane Yang Oct 26 '09 at 23:58 | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9485810399055481, "perplexity": 347.5198340304456}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": false}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1413558067768.10/warc/CC-MAIN-20141017150107-00321-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://www.wiredfaculty.com/board/question/CBSE/11/Laws+of+Motion?question_id=CBSEENPH11026339&q_type=all&page=145 | Laws of Motion
• Question 577
A moving body of mass m and velocity 3 km/h collides with a rest body ofmass 2 m and stick to it. Now the combined mass starts to move. What will be the combined velocity?4 km/h 1 km/h 2 km/h 3 km/h
Solution
B.
1 km/h
The law of conservation of momentum states that for two objects colliding in an isolated system, the total momentum before and after collision is equal.
Applying law of conservation of momentum
m1 v1 = MV
[ m2 v= 0 because v2 = 0 and M = m1 + m2 , V = final velocity
m × 3 = ( m + 2m ) v1
So, v1 = 1 km/h
Question 578
A block B is pushed momentarily along a horizontal surface with an initial velocity v. If is the coefficient of vlicling friction between B and the surface, block B will come to rest after a time $\frac{\mathrm{g}}{\mathrm{v}}$ $\frac{\mathrm{v}}{\mathrm{g}}$
Solution
A.
Block will come to rest, if force applied on it. It will vanish due to frictional force acting between block Band surface, i.e.,
Force applied = Frictional force
⇒ μ mg = ma
⇒ μ mg =
⇒ t =
Question 579
A block slides down on an incline of angle 30° with an acceleration $\frac{\mathrm{g}}{4}$, Find the kinetic 4 friction coefficient.$\frac{1}{2\sqrt{2}}$ 0.6 $\frac{1}{\sqrt{2}}$
Solution
C.
Consider the situation
Let the mass of block be m.
The equation of forces
mg sin 30o - f = $\frac{\mathrm{mg}}{4}$
f = .....( since sin30o$\frac{1}{2}$ )
f =
Also, N = mg cos 30° = mg $\frac{\sqrt{3}}{2}$
As the block is slipping on the incline, friction is
μn =
=
μn = $\frac{1}{2\sqrt{3}}$
Question 580
A pendulum having a bob of mass m is hanging in a ship sailing along the equator form east to west. When the strip is stationary with respect to water, the tension in the string is T0, The difference between T0 andearth attraction on the bob, is mω2 R
Solution
D.
2 R
The attraction of earth on the bob = Weight of bob = mg
Speed of ship due to rotation of the earth
Velocity = angular velocity × radius
v = ω R
Also due to the rotation of the earth, a centripetal force acts on the bob = mω2 R on earth
The net force
T0 = mg + mω2 R
⇒ T0 - mg = mω2 R | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 9, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8543941974639893, "perplexity": 3789.3095867344223}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046153709.26/warc/CC-MAIN-20210728092200-20210728122200-00102.warc.gz"} |
https://math.meta.stackexchange.com/questions/8787/how-ethical-is-accepting-an-answer-and-then-accepting-another-one-later-for-the/8793 | # How ethical is accepting an answer and then accepting another one later for the same question?
I am asking this question because I noticed how someone accepted an answer of mine and then "de-accepted" it and accepted another user's answer to the same question. My question is- is it OK to do so?
• Similar question (perhaps a duplicate): Is it rude to change which answer you accept? The OP of the other questions is "an asker" whereas here the OP is "an answerer", but I am not sure whether this makes too much of a distinction. – Martin Sleziak Mar 14 '13 at 7:14
• In general I see no problem with this. There may surface an answer that the OP likes better for some reason. But sometimes you do get a little annoyed. I know I did. – mrf Mar 14 '13 at 7:36
• Yes! ${}{}{}{}{}$ – Jyrki Lahtonen Mar 14 '13 at 7:55
• Arguably the real question here is: is it a good idea to accept an answer 17 minutes after asking the question and 2 minutes after receiving the first answer? – Martin Mar 14 '13 at 8:19
• It is 100% ethical. It is also within the rules of the system. You don't have to like it, but you do have to live with it. – MJD Mar 14 '13 at 15:16
• It has happened to me plenty, but the system is set up that way and I am kind of glad for it. – Ron Gordon Mar 14 '13 at 17:24
I would imagine that if it were not okay/ethical the system would have been set up to not allow it.
Sometimes users make mistakes when accepting answers; sometimes users are too hasty in accepting the first answer. I'm sure everyone who has answered more than a few questions has had the occasion to witness the de-acceptance of an answer; I know it's happened to me more than a few times that I've noticed.
While it is annoying and a bit of a hit to the ol' self-esteem, my advice is to let it slide, relax, don't resent the bastard questioner who de-accepted your answer. And most importantly continue answering questions!
• +1 And generally, it's on average better to be safe than sorry. That is, it is better to wait a bit before accepting an answer instead of changing the accepted answer all the time. – Michael Greinecker Mar 14 '13 at 8:32
• In fact, when someone accepts an answer of mine really quickly, I sometimes recommend to them to wait a bit if I feel that someone else might have something valuable to add. – Tara B Mar 14 '13 at 10:56
• Why is it better to wait instead of changing acceptances whenever you like? – GEdgar Mar 14 '13 at 14:09
• Because accepting an answer sharply decreases the chance that other people will post more answers. – MJD Mar 14 '13 at 15:57
I have posted many requests to OPs to un-accept my answers when they clicked the checkmark too quickly.
Usually the request is stated in words like "if you unaccept it is likelier that experts will see the question".
The OPs usually take this advice, and often the hoped for expert answers or complete analyses do materialize. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.5391571521759033, "perplexity": 847.5631343072241}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-17/segments/1618039490226.78/warc/CC-MAIN-20210420183658-20210420213658-00492.warc.gz"} |
http://scicomp.stackexchange.com/users/1117/arnold-neumaier | # Arnold Neumaier
less info
reputation
728
bio website mat.univie.ac.at/~neum location Vienna, Austria age member for 2 years, 7 months seen Oct 27 at 11:49 profile views 291
18 Scientific standards for numerical errors 16 Solving $(G^TA^{-1}G)x = b$ without inverting $A$ 13 MATLAB matrix multiplication (the best computational approach) 12 Algorithms for linear system of ODEs 12 What is the fastest way to calculate the largest eigenvalue of a general matrix?
# 9,222 Reputation
+10 Strategies for Newton's Method when the Jacobian at the solution is singular +10 Gradient descent to stationary, or accumulation point +30 Gershgorin Circle Theorem to estimate the eigenvalues +10 CVXOPT VS. OpenOpt
# 1 Question
9 large dense low rank assignment problem
# 94 Tags
276 linear-algebra × 59 72 iterative-method × 13 180 optimization × 44 67 algorithms × 14 125 matrices × 31 67 linear-solver × 11 115 eigensystem × 22 46 sparse × 6 80 numerics × 14 34 condition-number × 6
# 10 Accounts
Physics 18,180 rep 3161 Computational Science 9,222 rep 728 Mathematics 591 rep 213 MathOverflow 293 rep 9 Cross Validated 216 rep 17 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9349452257156372, "perplexity": 5150.469089638412}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2014-42/segments/1414637898842.15/warc/CC-MAIN-20141030025818-00107-ip-10-16-133-185.ec2.internal.warc.gz"} |
https://tex.stackexchange.com/questions/545577/csv-to-latex-chart | # csv to latex chart
What I want: to make a chart from a csv file (exp1.csv).
Problem:
1. I don't get all the data visible in the chart
2. The header of my table is not consistent (see \hline) Could you help me to solve those two problems?
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[left=3cm,top=3cm,right=3cm]{geometry}
\usepackage{tabularx}
\usepackage{xfrac}
\usepackage{float}
\newcolumntype{Y}{>{\small\raggedright\arraybackslash}X}
\usepackage{csvsimple}
\begin{filecontents*}{exp1.csv}
Ultrapure,0.406,0.384,0.362
Deionized,2.78,2.769,2.603
\end{filecontents*}
\begin{document}
\subsection*{Characterisation of chemicals}
\begin{table}[ht]{
\scalebox{1}{
\begin{tabularx}{\textwidth}{|Y||Y|Y|}
\bfseries Water type & \bfseries value 1 & \bfseries value 2\\
{\\\hline\csvcoli&\csvcolii& \csvcoliii}\\
\hline
\end{tabularx}}}
\end{table}
\end{document}
• Your csv file has four columns, hence I guess your tabular also need four columns.
• Your csv contains no table head, hence the use of option no head.
\documentclass[a4paper, 11pt]{article}
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[left=3cm,top=3cm,right=3cm]{geometry}
\usepackage{tabularx}
\usepackage{xfrac}
\usepackage{float}
\newcolumntype{Y}{>{\small\raggedright\arraybackslash}X}
\usepackage{csvsimple}
\begin{filecontents*}{exp1.csv}
Ultrapure,0.406,0.384,0.362
Deionized,2.78,2.769,2.603
\end{filecontents*}
\begin{document}
\subsection*{Characterisation of chemicals}
\begin{table}[ht]
\begin{tabularx}{\textwidth}{*3{|Y}|Y|}
\hline
\bfseries Water type & \bfseries value 1 & \bfseries value 2 & \bfseries value 3
\\ \hline
\end{tabularx}
\end{table}
\end{document}
### Follow-up: Multi-page tables with X column type
• Load ltablex and uses \keepXColumns to activate the effect of X column type.
• Move tabularx environment output of table floating environment, and use tabularx like longtable environment. For example, use \caption{...} \\ in tabularx to put an caption.
\documentclass[a4paper, 11pt]{article}
\usepackage[english]{babel}
\usepackage[utf8]{inputenc}
\usepackage[left=3cm,top=3cm,right=3cm]{geometry}
\usepackage{tabularx}
\usepackage{ltablex}
\keepXColumns
\usepackage{xfrac}
\usepackage{float}
\newcolumntype{Y}{>{\small\raggedright\arraybackslash}X}
\usepackage{csvsimple}
\begin{filecontents*}{exp1.csv}
Ultrapure,0.406,0.384,0.362
Deionized,2.78,2.769,2.603
\end{filecontents*}
\begin{document}
\subsection*{Characterisation of chemicals}
\begin{tabularx}{\textwidth}{XXXX}
\caption{text} \\
\hline
\bfseries Water type & \bfseries value 1 & \bfseries value 2 & \bfseries value 3
• @Elia: xltabular combines the features of tabularx (X type columns) and longtable(mid-table page breaks). Why would you need tabularx in the first place for this specific table? The only thing it does here is artificially making the table a lot wider than it needs to be, making it less readable. – leandriis May 22 '20 at 6:53
• @Elia I've appended a multi-page table with X column type to my answer. – muzimuzhi Z May 22 '20 at 6:56 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8712198734283447, "perplexity": 5263.901411793976}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-31/segments/1627046154085.58/warc/CC-MAIN-20210731074335-20210731104335-00094.warc.gz"} |
http://math.stackexchange.com/questions/30703/a-set-with-a-finite-integral-of-measure-zero | A set with a finite integral of measure zero?
Prove, or give a counter example: Let $\mu$ be a finite positive borel measure on $\mathbb{R}$. Then $\int (x-y)^{-2} d \mu (y) = \infty$ almost everywhere on $\mu$ (for the selection of x's).
This is a question I had in an exam, and the answer is supposed to be presented in less than 30 words, so there must be something quite simple I'm missing.
-
Maybe the Lebesgue decomposition theorem can be of some help? If $\mu$ is absolutely continuous or discrete the claim is easy to prove. EDIT: This is the theorem I'm referring to – Giuseppe Negro Apr 3 '11 at 19:18
I thought about it. But I don't see any easy way to solve either. Perhaps the continuous part (in respect to Lebesgue measure) could be shown to satisfy the infinite integral in any Lebesgue point on which the Radon differential has a non-zero value. But how would you deal with the singular part? – yaakov Apr 3 '11 at 19:26
Isn't any discrete measure a sum of Dirac's deltas? I recall something like that. Let it be $\nu=\sum_{n=0}^\infty \lambda_n \delta_{x_n}$: so $\int(x-y)^{-2}\, d\nu=+\infty$ when $x=x_n$, that is, $\nu$-almost everywhere. – Giuseppe Negro Apr 3 '11 at 19:30
why should it be? you can take any set of measure zero, and give it some funny distribution (take the Cantor distribution for example). EDIT: I think you are mistaking "singular" for "discrete", those are separate concepts. – yaakov Apr 3 '11 at 19:32
Oh, you edited. Yes, in fact I was referring to the discrete part, not the singular part. Neither I have any clue on how to handle the latter. – Giuseppe Negro Apr 3 '11 at 19:37
Yes it is true. Consider the set $S$ on which the integral in question is bounded by a positive value $K$. Then $\mu$ cannot have measure greater than $K\epsilon^2$ on any interval of width $\epsilon$ intersecting $S$. However, any interval $[a,b]$ can be divided into $n$ intervals of width $(b-a)/n$. So, $\mu(S\cap[a,b])$ is bounded by $n K ((b-a)/n)^2$. Let $n$ go to infinity.
I didn't count, but I know that exceeded 30 words by a fair margin.
The argument is easily adapted to show that $\int\vert x-y\vert^{-1-\epsilon}\,d\mu(y)$ is infinite $\mu$-almost everywhere for any $\epsilon > 0$. The more difficult question is whether the same holds for $\int\vert x-y\vert^{-1}\,d\mu(y)$.
-
Could you please explain why $\mu$ cannot have measure greater than $K\epsilon^2$ on an interval of length $\epsilon$ intersecting $S$? (I know it's been a while since you posted this answer, but I am seeing it only now, after more than four years!) – Giuseppe Negro Sep 11 '15 at 21:05
@GiuseppeNegro: If $I$ is an interval of width $\epsilon$ and $x\in S\cap I$, then, the function $y\mapsto\epsilon^2(x-y)^{-2}$ is bounded below by $1$ on this interval. So, $\mu(I)\le\epsilon^2\int(x-y)^{-2}\mu(dy)\le\epsilon^2K$. – George Lowther Sep 15 '15 at 19:46
I have got it. Thank you. – Giuseppe Negro Sep 16 '15 at 23:32
this is a clumsy solution and certainly too long - but anyway. The answer is yes. There is a (weakly) increasing function $f:I\to\mathbb{R}$ such that $\mu$ is the push-forward of the Lebesgue measure on $I$ to $\mathbb{R}$ ($f$ is, roughly speaking, the inverse of $F(x)=\mu((-\infty,x])$). Your integral becomes $\int_I (f(x)-f(y))^{-2} dy$ (where "your $x$" is "my $f(x)$"). Since $f$ is monotone, it has a derivative a.e. If $x$ is in the set where the derivative is $<A$ (for any positive $A$) then the integral is $\infty$ by comparison with $\int_I (x-y)^{-2} dy$. Hence the integral is $\infty$ for a.e. $x$.
(not very pretty - but possibly correct :)
-
Looks like it works. And it should also apply to $\int\vert x-y\vert^{-1}\,d\mu(y)$. Or, indeed, to $\int\theta(\vert x-y\vert)\,dy$ for any decreasing function $\theta$ satisfying $\int^{0+}\theta(x)\,dx=\infty$. – George Lowther Apr 3 '11 at 22:30 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.9873911142349243, "perplexity": 194.52925799399813}, "config": {"markdown_headings": false, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2016-30/segments/1469257826907.66/warc/CC-MAIN-20160723071026-00305-ip-10-185-27-174.ec2.internal.warc.gz"} |
http://mathoverflow.net/questions/44068/which-integer-recurrence-relations-can-be-formulated-as-counting-walks-on-a-grap?sort=oldest | # Which integer recurrence relations can be formulated as counting walks on a graph?
Observation: If we take the graph with two vertices, A and B, with a loop {A,A} and undirected edge {A,B}, then the number of closed walks $W_n$ of length $n \geq 1$ starting from A we get $W_1=1$ (counting AA), $W_2=2$ (counting AAA and ABA) and $W_n=W_{n-1}+W_{n-2}$, i.e. the Fibonacci numbers.
Question: Which types of recurrences can be realised as the number of closed walks from the origin of a graph?
More generally, which types of recurrences can be realised as the number of walks of some type in some graph?
If we can interpret a recurrence relation as the number of walks in a graph in some way, then might be able to use spectral theory to find formulas for the sequence. (see: Frank Harary and Allen J. Schwenk, The spectral approach to determining the number of walks in a graph. Pacific J. Math. Volume 80, Number 2 (1979), 443-449.)
-
Duplicate? mathoverflow.net/questions/3939/… – Qiaochu Yuan Oct 29 '10 at 8:04
Must the graphs be undirected? (Your example has undirected edges, but you don't state that in your question itself.) – Mike Spivey Oct 29 '10 at 17:26
At this point, I don't care about the specifics, just as long as it's possible to count walks. – Douglas S. Stones Oct 29 '10 at 21:40
@Mike-Spivey, the undirected graph can be transformed into a directed graph, retaining the "undirectedness" of the original graph by: replacing each undirected edge between two vertices with a pair of directed edges between the same two vertices. A directed graph version of this allows for a direct correspondence to the class of regular languages accepted by a Nondeterministic Finite Automaton. (see my comment below Qiaochu Yuan's answer on this page) – sleepless in beantown Oct 30 '10 at 8:02
Okay, so it's not quite a duplicate because I guess you're asking about initial conditions as well. The generating functions of the sequences $a_n$ which have this property are called $\mathbb{N}$-recognizable or $\mathbb{N}$-rational in the literature, and they are essentially (precisely?) the generating functions of word lengths in regular languages (star example: the look-and-say sequence). Not all rational functions with non-negative integer coefficients are $\mathbb{N}$-rational; see for example the counterexamples in these slides. These slides also seem relevant.
Stanley's Enumerative Combinatorics discusses some of these issues, in particular look at Section 4.7.
-
Let me mention that one class of examples includes all recurrences with non-negative integer coefficients and non-negative integer initial conditions; the proof is to take the graph whose adjacency matrix is the companion matrix of the characteristic polynomial. This idea can be used to give a combinatorial proof of the Newton-Girard identities: see qchu.wordpress.com/2009/08/23/… and qchu.wordpress.com/2009/11/04/… . – Qiaochu Yuan Oct 29 '10 at 11:54
@qiaochu-yuan, I believe that they are precisely / exactly the same as regular languages. A perfect correspondence exists between the regular languages and the Finite State Machine representation of these regular languages as directed graphs of a probabilistic automaton. In this case, every node is an accepting node, and replace every undirected edge with a pair of directed edges. Now, in Formal Language Theory, this graph is a representation of the FSM which accepts that regular language. – sleepless in beantown Oct 30 '10 at 5:27
If the motivation is to use spectral methods, then there is no need to interpret things as a graph. To count walks in a graph one gets a recurrence relation (given by the adjacency matrix) and proceeds using spectral methods. If $A$ is an $n \times n$ matrix and $x_0$ a column vector then setting $x_{m+1}=Ax_m$ leads to a system of $n$ first order linear recurrences in the $n$ positions. In most non-degenerate cases one can get a single $nth$ order recurrence for a particular entry (or linear combination of entries). Similarly for the $r,c$ entry of $A^m$, the trace and other linear combinations. Really one is studying the entries of $A^m$ since $A^mx_0=x_m$. In the case that one starts with an $nth$ order linear recurrence one just has a rather special kind of graph.
That said, if the entries of $A$ are non-negative integers then one can naturally interpret $A^m$ as counting length $m$ walks in a certain $n$-vertex directed graph with multiple edges and loops allowed. For an arbitrary $n \times n$ matrix with entries from a ring one could consider the entries as multiplicitive edge weights on the complete $n$-vertex directed graph (with loops) and $A^m$ as recording in position $u,v$ the total weight of the length $m$ paths starting at $u$ and ending at $v$.
But again, once one enjoys the fact that every linear recurrence can be interpreted as a weighted path enumeration problem, there is usual not much motivation to actually do so. I suppose that the initial conditions are not really accounted for in this sketch, but they don't really come into solving recurrence relations until the very end.
- | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 1, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8392688035964966, "perplexity": 238.0303579290168}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398464536.35/warc/CC-MAIN-20151124205424-00333-ip-10-71-132-137.ec2.internal.warc.gz"} |
http://compgroups.net/comp.lang.javascript/string-manipulation-textarea-input-help/24490 | COMPGROUPS.NET | Search | Post Question | Groups | Stream | About | Register
### String manipulation / TEXTAREA input help
• Email
• Follow
Does js have some way of doing what I want here:
I want to paste a multiline block of text into a TEXTAREA form field,
and there is data in the block of text that I want to extract into a
variable. It's always going to be as the same column and row position
of the block of text.
For example, I want to extract the text from the block from say Line 3,
column 4 through Line 3, column 15 into a variable.
For an more hands on example, say I paste this into the textarea:
BLAH BLAH ARRIVAL ETA: 10:00 BLAH BLAH
BLAH BLAH DEPART ETA: 14:30 BLAH BLAH
and I want to capture the 2 eta's into 2 seperate variables.
Is this possible, and if so, can I get a little help on how? Many TIA
0
Reply yerk5 (8) 3/9/2005 3:50:33 PM
See related articles to this posting
yerk5@hotmail.com wrote:
> Does js have some way of doing what I want here:
>
> I want to paste a multiline block of text into a TEXTAREA form field,
> and there is data in the block of text that I want to extract into a
> variable. It's always going to be as the same column and row position
> of the block of text.
>
> For example, I want to extract the text from the block from say Line
3,
> column 4 through Line 3, column 15 into a variable.
>
> For an more hands on example, say I paste this into the textarea:
>
> BLAH BLAH ARRIVAL ETA: 10:00 BLAH BLAH
> BLAH BLAH DEPART ETA: 14:30 BLAH BLAH
>
> and I want to capture the 2 eta's into 2 seperate variables.
>
> Is this possible, and if so, can I get a little help on how? Many TIA
It's hard to tell from your question what the criteria will be for
finding the data - the row and (or) column number, or the format of the
strings involved. You need to be really specific about this to suggest
a reasonably robust method of isolating the appropriate characters. If
that "ETA:" business is indicative, here's one way -
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
<html>
<title>untitled</title>
<style type=3D"text/css">
#extractor {
width: 400px;
height: 200px;
}
input {
width: 80px;
}
</style>
<script type=3D"text/javascript">
var test =3D
'BLAH BLAH ARRIVAL ETA: 10:00 BLAH BLAH\n' +
'BLAH BLAH DEPART ETA: 14:30 BLAH BLAH';
function extract(obj)
{
obj.data =3D [];
var x, re =3D /ETA:\s*(\S+)/gi;
while (x =3D re.exec(obj.value))
obj.data.push(x[1]);
}
</script>
<body>
<form>
<textarea
id=3D"extractor"
name=3D"extractor">
</textarea>
<input
type=3D"button"
value=3D"paste"
onclick=3D"extractor.value=3Dtest" />
<input type=3D"button"
value=3D"test"
onclick=3D"extract(extractor)" />
</form>
</body>
</html>
Populates an array. If that's not it, be more specific. #:-)
0
Reply RobB 3/9/2005 5:52:56 PM
yerk5@hotmail.com wrote:
[...]
>
> For an more hands on example, say I paste this into the textarea:
>
> BLAH BLAH ARRIVAL ETA: 10:00 BLAH BLAH
> BLAH BLAH DEPART ETA: 14:30 BLAH BLAH
>
> and I want to capture the 2 eta's into 2 seperate variables.
>
> Is this possible, and if so, can I get a little help on how? Many TIA
>
String.match(regular expresssion)
You need a regex to weed out the ETA. Something like:
str= (reference to textfield value);
ETAs = str.match(/\s(([01][0-9])|(2[0-5])):[0-5][0-9]\s/g);
var arrive=ETAs[0];
var depart=ETAs[1];
Someone may provide a better regex.
Mick
0
Reply Mick 3/9/2005 6:31:04 PM
Wow much appreciated. To get specific, the strings I want to extract
will not actually be prefixed with any delimiting word or phrase, so I
think maybe trying to string match wont work.
Here's a sample of what I'd really be using. I'd want to paste (and
it's going to look horrible if youre not viewing this with a fixed
width font):
|---------||-|---|--|----------------|--|-|-|-|----|
|City |St|Exc|SC|Eta 21:11 hrs |Cn|C|P|D|Rte |
:---------:--:---:--:----------------:--:-:-:-:----:
|CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|
|INDEPENDE|OR|RNO| |03/11/2005 15:32| |C|N|N|0960|
| | | | | | | | | | |
So the dates and time are what I want to extract out into a var. The
only thing constant about them will be their position, so I'm thinking
that woudl be the best approach to capturing them, but I'm lost as to
how. :(
0
Reply yerk5 3/10/2005 10:52:24 PM
yerk5@hotmail.com wrote:
> Wow much appreciated. To get specific, the strings I want to extract
> will not actually be prefixed with any delimiting word or phrase, so I
> think maybe trying to string match wont work.
>
> Here's a sample of what I'd really be using. I'd want to paste (and
> it's going to look horrible if youre not viewing this with a fixed
> width font):
>
> |---------||-|---|--|----------------|--|-|-|-|----|
> |City |St|Exc|SC|Eta 21:11 hrs |Cn|C|P|D|Rte |
> :---------:--:---:--:----------------:--:-:-:-:----:
> |CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|
> |INDEPENDE|OR|RNO| |03/11/2005 15:32| |C|N|N|0960|
> | | | | | | | | | | |
>
> So the dates and time are what I want to extract out into a var. The
> only thing constant about them will be their position, so I'm thinking
> that woudl be the best approach to capturing them, but I'm lost as to
> how. :(
>
Are the pipes present in the textarea? (|||)
But it looks like you need a regex for the date and combine it with time
regex I provided earlier.
var re=/((0[1-9])|(1[012]))\/((0[1-9])|([12][0-9])|(3[01]))\/200[56]/g
a="02/11/2006 and 02/12/2006".match(re);
Mick
Mick
0
Reply Mick 3/11/2005 12:48:42 AM
yerk5@hotmail.com wrote:
> Wow much appreciated. To get specific, the strings I want to extract
> will not actually be prefixed with any delimiting word or phrase, so
I
> think maybe trying to string match wont work.
>
> Here's a sample of what I'd really be using. I'd want to paste (and
> it's going to look horrible if youre not viewing this with a fixed
> width font):
>
> |---------||-|---|--|----------------|--|-|-|-|----|
> |City |St|Exc|SC|Eta 21:11 hrs |Cn|C|P|D|Rte |
> :---------:--:---:--:----------------:--:-:-:-:----:
> |CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|
> |INDEPENDE|OR|RNO| |03/11/2005 15:32| |C|N|N|0960|
> | | | | | | | | | | |
>
> So the dates and time are what I want to extract out into a var. The
> only thing constant about them will be their position, so I'm
thinking
> that woudl be the best approach to capturing them, but I'm lost as to
> how. :(
See if this is anywhere in the vicinity...
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
<html>
<title>untitled</title>
<style type=3D"text/css">
#extractor {
width: 440px;
height: 100px;
}
input {
width: 80px;
}
</style>
<script type=3D"text/javascript">
function extract(obj)
{
var citypos, etapos,
oData =3D {}, str, spc, city, date, time,
line, lines =3D obj.value.split('\n');
for (var l =3D 0, ls =3D lines.length; l < ls; ++l)
{
line =3D lines[l];
citypos =3D etapos =3D -1;
citypos =3D line.search(/\bcity\b/i);
etapos =3D line.search(/\beta\b/i);
if (citypos > -1 && etapos > -1)
break;
}
for (++l; l < ls; ++l)
{
line =3D lines[l];
str =3D line.substring(citypos);
if (city =3D str.match(/[a-z]+/i))
{
str =3D line.substring(etapos);
if (spc =3D str.indexOf(' '))
date =3D str.substring(0, spc);
time =3D str.substring(spc + 1);
if (/\d{1,2}\/\d{1,2}\/\d{2,4}/.test(date)
&& (time =3D time.match(/\d{1,2}:\d{1,2}/)))
{
oData[city] =3D { date: date, time: time };
}
}
}
return oData;
}
function showData(obj)
{
var data =3D extract(obj);
var str =3D '';
for (city in data)
str +=3D 'city: ' + city +
'\ndate: ' + data[city]['date'] +
'\ntime: ' + data[city]['time'] + '\n\n';
}
</script>
<body>
<form>
<textarea
id=3D"extractor"
|City |St|Exc|SC|Eta 21:11 hrs |Cn|C|P|D|Rte |
|CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|
|INDEPENDE|OR|RNO| |03/11/2005 15:32| |C|N|N|0960|
| | | | | | | | | | |</textarea>
<input type=3D"button"
value=3D"test"
onclick=3D"showData(extractor)" />
</form>
</body>
</html>
(assuming googlegroups doesn't mangle it beyond repair). Not sure what
you wanted, exactly. This returns an object (oData) whose properties
(named for the city in question) contain another object with 'date' &
'time' properties, self-explanatory. Easily rearranged mini-dB. Overdid
the parsing a bit but it's not entirely clear how reliably formatted
the pasted string will be.
Of course, if Mick W. nailed it,
just
ignore
this &
have a nice day.
#:=3DD
0
Reply RobB 3/11/2005 6:22:37 AM
JRS: In article <1110495144.643904.198990@z14g2000cwz.googlegroups.com>
, dated Thu, 10 Mar 2005 14:52:24, seen in news:comp.lang.javascript,
yerk5@hotmail.com posted :
>Here's a sample of what I'd really be using. I'd want to paste (and
>it's going to look horrible if youre not viewing this with a fixed
>width font):
>
>|---------||-|---|--|----------------|--|-|-|-|----|
>|City |St|Exc|SC|Eta 21:11 hrs |Cn|C|P|D|Rte |
>:---------:--:---:--:----------------:--:-:-:-:----:
>|CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|
>|INDEPENDE|OR|RNO| |03/11/2005 15:32| |C|N|N|0960|
>| | | | | | | | | | |
>
>So the dates and time are what I want to extract out into a var. The
>only thing constant about them will be their position, so I'm thinking
>that woudl be the best approach to capturing them, but I'm lost as to
>how. :(
x = "|CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|".
substring(21,37)
x = "|CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|".
match(/.{21}(.{16})/)[1]
each give "03/10/2005 17:21". Beware possible FFF date ambiguities in
differently-configured browsers; dates should be written as 2005/10/03.
--
� John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v4.00 IE 4 �
<URL:http://www.jibbering.com/faq/> JL/RC: FAQ of news:comp.lang.javascript
<URL:http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.
0
Reply Dr 3/11/2005 6:37:21 PM
RobB wrote:
(snip)
> See if this is anywhere in the vicinity...
All right, street-swept the vicinity a tad. This is cleaner.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
<html>
<title>untitled</title>
<style type=3D"text/css">
body {
font: 11px monospace;
color: #fff;
background: #888;
}
#extractor {
text-align: center;
background: buttonface;
overflow: hidden;
}
</style>
<script type=3D"text/javascript">
function extract(obj)
{
var citypos, etapos, oData =3D {},
str, spc, city, date, time,
line, lines =3D obj.value.split('\n');
for (var i =3D 0, ll =3D lines.length; i < ll; ++i)
{
line =3D lines[i];
if ((citypos =3D line.search(/\bcity\b/i)) > -1
&& (etapos =3D line.search(/\beta\b/i)) > -1)
{
var cre =3D /[a-z]+/i,
dre =3D /\d{1,2}\/\d{1,2}\/\d{2,4}/,
tre =3D /\d{1,2}:\d{1,2}/;
break;
}
}
for (++i; i < ll; ++i)
{
line =3D lines[i];
str =3D line.substring(citypos);
if (city =3D str.match(cre))
{
str =3D line.substring(etapos);
if ((spc =3D str.indexOf(' ')) > -1)
{
date =3D str.substring(0, spc);
time =3D str.substring(spc + 1).match(tre);
if (dre.test(date) && null !=3D time)
{
oData[city] =3D { date: date, time: time };
}
}
}
}
return oData;
}
function showData(id)
{
var obj =3D document.getElementById(id),
data =3D extract(obj),
arr =3D ['\n\n'];
for (city in data)
arr.push(
'city: =B7', city,
'=B7\ndate: ', data[city].date,
'\ntime: ', data[city].time,
'\n\n'
);
}
</script>
<body>
<textarea id=3D"extractor"
name=3D"extractor"
rows=3D"9"
cols=3D"53">
|City |St|Exc|SC|Eta 21:11 hrs |Cn|C|P|D|Rte |
|CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|
|NEEDLES |CA|LAX| |03/11/2005 05:00| |C|L|L|0960|
|RENO |NV|RNO| |03/11/2005 10:44| |W|U|J|1234|
|INDEPENDE|OR|RNO| |03/11/2005 15:32| |C|N|N|2579|
|LOGAN |UT|SLK| |03/12/2005 02:09| |K|H|B|8873|
| | | | | | | | | | |
</textarea>
<span style=3D"cursor:pointer;" onclick=3D"showData('extractor')">
→ click</span>
</body>
</html>
0
Reply RobB 3/11/2005 8:43:49 PM
JRS: In article <KV5Yd.87955\$H05.69408@twister.nyroc.rr.com>, dated
Fri, 11 Mar 2005 00:48:42, seen in news:comp.lang.javascript, Mick White
<mwhite13BOGUS@rochester.rr.com> posted :
>yerk5@hotmail.com wrote:
>> |---------||-|---|--|----------------|--|-|-|-|----|
>> |City |St|Exc|SC|Eta 21:11 hrs |Cn|C|P|D|Rte |
>> :---------:--:---:--:----------------:--:-:-:-:----:
>> |CHINO |CA|ONT| |03/10/2005 17:21|Y |N|C|N|0000|
>> |INDEPENDE|OR|RNO| |03/11/2005 15:32| |C|N|N|0960|
>> | | | | | | | | | | |
>>
>> So the dates and time are what I want to extract out into a var
>Are the pipes present in the textarea? (|||)
>But it looks like you need a regex for the date and combine it with time
>regex I provided earlier.
>
>var re=/((0[1-9])|(1[012]))\/((0[1-9])|([12][0-9])|(3[01]))\/200[56]/g
ISTM grossly unlikely that any other field will look anything like date-
and-time; so /\d\d\/\d\d\/\d{4} \d\d:\d\d/ will pick it up reliably -
and will not fail when 2007 arrives. In fact, /([0-9/ :]{16})/ will do.
Beware of pre-over-validation when selecting; ISTM better to be willing
to detect the most plausible field for date and time, even if it is not
quite on-spec - for example, the day might be given as 3 rather than 03
if the data is manually input. Since it is the fifth field that is
wanted,
x = "|CHINO |CA|ONT| |03/10/2505 17:21|Y |N|C|N|0000|".
split('|')[5]
might be appropriate (but take care with split if the divider starts the
string).
If the date/time is wanted for calculation, it should be validated for
month-length in the usual manner - the string can be liberally broken up
with .split(/\D+/) .
--
� John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v4.00 IE 4 �
<URL:http://www.jibbering.com/faq/> JL/RC: FAQ of news:comp.lang.javascript
<URL:http://www.merlyn.demon.co.uk/js-index.htm> jscr maths, dates, sources.
<URL:http://www.merlyn.demon.co.uk/> TP/BP/Delphi/jscr/&c, FAQ items, links.
0
Reply Dr 3/11/2005 10:45:32 PM
8 Replies
2331 Views
Similar Articles
12/7/2013 12:06:42 AM
page loaded in 243898 ms. (0) | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.4147489368915558, "perplexity": 25941.311532054144}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2013-48/segments/1386164004946/warc/CC-MAIN-20131204133324-00072-ip-10-33-133-15.ec2.internal.warc.gz"} |
https://homework.cpm.org/category/CCI_CT/textbook/int2/chapter/6/lesson/6.1.2/problem/6-24 | ### Home > INT2 > Chapter 6 > Lesson 6.1.2 > Problem6-24
6-24.
Use the information given for each diagram below to solve for $x$. Show all work.
1. $\overrightarrow{ B D }$ bisects $∠ABC$. (Remember that an angle bisector divides the angle into two congruent angles.) If $m∠ABD = 5x - 10^\circ$ and $m∠ABC = 65^\circ$, solve for $x$.
$2(5x - 10^\circ) = 65^\circ$
1. Point $M$ is a midpoint of $\overline{EF}$. If $EM = 4x - 2$ and $MF = 3x + 9$, solve for $x$.
If $M$ is the midpoint, how are $EM$ and $MF$ related?
1. $WXYZ$ at right is a parallelogram. If $m∠W = 9x - 3^\circ$ and $m∠Z = 3x + 15^\circ$, solve for $x$.
How are the angles of the parallelogram related? | {"extraction_info": {"found_math": true, "script_math_tex": 19, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.920360803604126, "perplexity": 599.8994915735814}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-10/segments/1614178356232.19/warc/CC-MAIN-20210226060147-20210226090147-00454.warc.gz"} |
https://worldwidescience.org/topicpages/b/breakage+dna+adducts.html | #### Sample records for breakage dna adducts
1. Titanium dioxide nanoparticles induce oxidative stress and DNA-adduct formation but not DNA-breakage in human lung cells
Directory of Open Access Journals (Sweden)
Schins Roel PF
2009-06-01
Full Text Available Abstract Titanium dioxide (TiO2, also known as titanium (IV oxide or anatase, is the naturally occurring oxide of titanium. It is also one of the most commercially used form. To date, no parameter has been set for the average ambient air concentration of TiO2 nanoparticles (NP by any regulatory agency. Previously conducted studies had established these nanoparticles to be mainly non-cyto- and -genotoxic, although they had been found to generate free radicals both acellularly (specially through photocatalytic activity and intracellularly. The present study determines the role of TiO2-NP (anatase, ∅ in vitro. For comparison, iron containing nanoparticles (hematite, Fe2O3, ∅ 2-NP did not induce DNA-breakage measured by the Comet-assay in both cell types. Generation of reactive oxygen species (ROS was measured acellularly (without any photocatalytic activity as well as intracellularly for both types of particles, however, the iron-containing NP needed special reducing conditions before pronounced radical generation. A high level of DNA adduct formation (8-OHdG was observed in IMR-90 cells exposed to TiO2-NP, but not in cells exposed to hematite NP. Our study demonstrates different modes of action for TiO2- and Fe2O3-NP. Whereas TiO2-NP were able to generate elevated amounts of free radicals, which induced indirect genotoxicity mainly by DNA-adduct formation, Fe2O3-NP were clastogenic (induction of DNA-breakage and required reducing conditions for radical formation.
2. DNA single strand breakage, DNA adducts, and sister chromatid exchange in lymphocytes and phenanthrene and pyrene metabolites in urine of coke oven workers.
OpenAIRE
W. Popp; Vahrenholz, C.; Schell, C; Grimmer, G.; Dettbarn, G; Kraus, R.; Brauksiepe, A; Schmeling, B; Gutzeit, T; von Bülow, J; Norpoth, K
1997-01-01
OBJECTIVES: To investigate the specificity of biological monitoring variables (excretion of phenanthrene and pyrene metabolites in urine) and the usefulness of some biomarkers of effect (alkaline filter elution, 32P postlabelling assay, measurement of sister chromatid exchange) in workers exposed to polycyclic aromatic hydrocarbons (PAHs). METHODS: 29 coke oven workers and a standardised control group were investigated for frequencies of DNA single strand breakage, DNA protein cross links (al...
3. DNA adducts as molecular dosimeters
International Nuclear Information System (INIS)
4. DNA breakage drives nuclear search
OpenAIRE
Ira, Grzegorz; Hastings, Philip J.
2012-01-01
The search for a homologous template is a fundamental, yet largely uncharacterized, reaction in DNA double-strand break repair. Two reports now demonstrate that broken chromosomes increase their movement and explore large volumes of nuclear space searching for a homologous template. Break mobility requires resection and recombination enzymes, as well as damage-checkpoint components.
Directory of Open Access Journals (Sweden)
T R Rajalakshmi
2015-01-01
Full Text Available DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde. This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could be carried out for early detection of cancer. When scanning tunneling microscope is used, the DNA results can be obtained earlier. DNA adducts in scientific experiments are used as biomarkers.
Science.gov (United States)
Rajalakshmi, T. R.; AravindhaBabu, N.; Shanmugam, K. T.; Masthan, K. M. K.
2015-01-01
DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde). This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could be carried out for early detection of cancer. When scanning tunneling microscope is used, the DNA results can be obtained earlier. DNA adducts in scientific experiments are used as biomarkers. PMID:26015708
7. Sperm DNA oxidative damage and DNA adducts.
Science.gov (United States)
Jeng, Hueiwang Anna; Pan, Chih-Hong; Chao, Mu-Rong; Lin, Wen-Yi
2015-12-01
The objective of this study was to investigate DNA damage and adducts in sperm from coke oven workers who have been exposed to polycyclic aromatic hydrocarbons. A longitudinal study was conducted with repeated measurements during spermatogenesis. Coke-oven workers (n=112) from a coke-oven plant served the PAH-exposed group, while administrators and security personnel (n=67) served the control. Routine semen parameters (concentration, motility, vitality, and morphology) were analyzed simultaneously; the assessment of sperm DNA integrity endpoints included DNA fragmentation, bulky DNA adducts, and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dGuo). The degree of sperm DNA fragmentation was measured using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and sperm chromatin structure assay (SCSA). The PAH-exposed group had a significant increase in bulky DNA adducts and 8-oxo-dGuo compared to the control subjects (Ps=0.002 and 0.045, respectively). Coke oven workers' percentages of DNA fragmentation and denaturation from the PAH-exposed group were not significantly different from those of the control subjects (Ps=0.232 and 0.245, respectively). Routine semen parameters and DNA integrity endpoints were not correlated. Concentrations of 8-oxo-dGuo were positively correlated with percentages of DNA fragmentation measured by both TUNEL and SCSA (Ps=0.045 and 0.034, respectively). However, the concentrations of 8-oxo-dGuo and percentages of DNA fragmentation did not correlate with concentrations of bulky DNA adducts. In summary, coke oven workers with chronic exposure to PAHs experienced decreased sperm DNA integrity. Oxidative stress could contribute to the degree of DNA fragmentation. Bulky DNA adducts may be independent of the formation of DNA fragmentation and oxidative adducts in sperm. Monitoring sperm DNA integrity is recommended as a part of the process of assessing the impact of occupational and environmental toxins on sperm
OpenAIRE
T. R. Rajalakshmi; N AravindhaBabu; Shanmugam, K. T.; Masthan, K. M. K.
2015-01-01
DNA adduct is a piece of DNA covalently bond to a chemical (safrole, benzopyrenediol epoxide, acetaldehyde). This process could be the start of a cancerous cell. When a chemical binds to DNA, it gets damaged resulting in abnormal replication. This could be the start of a mutation and without proper DNA repair, this can lead to cancer. It is this chemical that binds with the DNA is our prime area of concern. Instead of performing the whole body analysis for diagnosing cancer, this test could b...
9. Estimates of DNA strand breakage in bottlenose dolphin (Tursiops truncatus)
OpenAIRE
Blanco, M.; Cruz, D.; Carro, S.; López, R.; Díaz, A.; Santiago, L; Guevara, C.; Sánchez, L.; Cuetara, E.B.; López, N.
2009-01-01
The analysis of DNA damage by mean of Comet or single cell gel electrophoresis (SCGE) assay has been commonly used to assess genotoxic impact in aquatic animals being able to detect exposure to low concentrations of contaminants in a wide range of species. The aims of this work were 1) to evaluate the usefulness of the Comet to detect DNA strand breakage in dolphin leukocytes, 2) to use the DNA diffusion assay to determine the amount of DNA strand breakage associated with apoptosi...
10. [DNA adducts in human female genital organs].
Science.gov (United States)
Postawski, Krzysztof; Przadka-Rabaniuk, Dorota; Monist, Marta; Baranowski, Włodzimierz
2007-12-01
DNA adducts, one of genetic damages markers, precede and finally can lead to oncogenic mutations. They appear in genome as a result of DNA bases damages caused by various and numerous environmental factors eg. ultraviolet light, ionic radiation, toxins and also endogenic substances, for example estrogens. It is believed that the creation of DNA adducts is a necessary but insufficient process for the neoplastic transformation of the cell. The following review presents concise knowledge about the DNA adducts creation and their sequels served in healthy and cancerous tissues of the female genital organs, on the base of the available data. PMID:18411923
Institute of Scientific and Technical Information of China (English)
1999-01-01
Objective. DNA modification fixed as mutations in the cells may be an essential factor in the initiation step of chemical carcinogenesis. In order to explore the mechanism of gene mutation and cell transformation induced by glycidyl methacrylate (GMA), the current test studied the characteristics of GMA-DNA adducts formation in vitro.Methods. In vitro test, dAMP, dCMP, dGMP, dTMP and calf thymus DNA were allowed to react with GMA (Glycidyl Methacrylate). After the reaction, the mixtures were detected by UV and subjected to reversed-phase HPLC on ultrasphere ODS reversed-phase column, the reaction products were eluted with a linear gradients of methanol (solvent A) and 10mmol/L ammonium formate, pH5.0 (solvent B). The synthesized adducts were then characterized by UV spectroscopy in acid (pH1.0), neutral (pH7.2), alkaline (pH11.0) and by mass spectroscopy.Results. The results showed that GMA could bind with dAMP, dCMP, dGMP and calf thymus DNA by covalent bond, and the binding sites were specific (N6 of adenine, N3 of cytosine). Meanwhile, a main GMA-DNA adduct in the reaction of GMA with calf thymus DNA was confirmed as N3-methacrylate-2-hydroxypropy1-dCMP.Conclusions. GMA can react with DNA and /or deoxynucleotide monophosphate and generate some adducts such as N6-methacrylate-2-hydroxypropyl-dAMP and N3-methacrylate-2-hydroxypropyl-dCMP, ets. Formation of GMA-DNA adducts is an important molecular event in gene mutation and cell transformation induced by GMA.
12. Protection of DNA strand breakage by radiation exposure
Energy Technology Data Exchange (ETDEWEB)
Lee, Jeong Ho; Kim, In Gyu; Lee, Kang Suk; Kim, Kug Chan; Shim, Hae Won
1997-12-01
Human ceruloplasmin, the plasma copper containing protein, is thought to play an essential role in iron metabolism, but it also has antioxidant properties. Ceruloplasmin directly scavenged hydroxyl radicals (.OH) generated in dithiothreitol/FeCl{sub 3} system besides inhibitory function of hydroxyl radical formation and lipid peroxidation. Polyamines, spermidine and spermine, significantly protected the supercoiled DNA strand breakage by hydroxyl radicals and DNA strand breakage by UV was highly protected by all four polyamines used in this study. In polyamine deficient mutant KL527. It was shown that cell survivability following UV irradiation was slightly increased by exogenous polyamines putrescine and spermidine supplement. However the cell survivability of wild type (MG 1655) was not influenced by polyamine supplement. In {gamma}-irradiated cells, cell survivability of polyamine-deficient mutant strain KL527 was significantly increased by exogenous putrescine supplement and that of wild type strain MG1655 was similar irrespective of polyamine supplement. These results implicate the possibility that polyamines play a potent role in radioprotection of cell and DNA level. (author). 32 refs., 8 figs
13. Quantitation of DNA adducts by stable isotope dilution mass spectrometry
OpenAIRE
Tretyakova, Natalia; Goggin, Melissa; Janis, Gregory
2012-01-01
Exposure to endogenous and exogenous chemicals can lead to the formation of structurally modified DNA bases (DNA adducts). If not repaired, these nucleobase lesions can cause polymerase errors during DNA replication, leading to heritable mutations potentially contributing to the development of cancer. Due to their critical role in cancer initiation, DNA adducts represent mechanism-based biomarkers of carcinogen exposure, and their quantitation is particularly useful for cancer risk assessment...
14. 32P-adduct assay: Comparative recoveries of structurally diverse DNA adducts in the various enhancement procedures
International Nuclear Information System (INIS)
A (32)P-adduct assay for the measurement of low levels (1 adduct per 10(sup 7) nucleotides) of binding of carcinogens to DNA has been reported previously. In this procedure, DNA is enzymatically hydrolyzed to 3'-monophosphates of normal nucleosides and adducts, which are 5'-(32)P-labeled by T4 polynucleotide kinase and (lambda(32)P)ATP. Labeled adducts are resolved by TLC. Enrichment of adducts by extraction in 1-butanol or digestion with nuclease P1 prior to (32)P-labeling, however, increased the sensitivity of detection for many adducts to a level of 1 per 10(sup 9-10) nucleotides, although adduct recovery particularly in the latter assay depended on the chemical nature of adducts. The observation that chemical structure of an adduct may be detrimental in its recovery in the enzyme- and extraction-mediated enrichment procedures may serve as a probe in the structural characterization of adducts of unknown carcinogens
15. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry
International Nuclear Information System (INIS)
This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs
16. Photochemistry of psoralen-DNA adducts, biological effects of psoralen-DNA adducts, applications of psoralen-DNA photochemistry
Energy Technology Data Exchange (ETDEWEB)
Shi, Yun-bo
1988-03-01
This thesis consists of three main parts and totally eight chapters. In Part I, The author will present studies on the photochemistry of psoralen-DNA adducts, specifically, the wavelength dependencies for the photoreversals of thymidine-HMT (4'-hydroxymethyl-4, 5', 8-trimenthylpsoralen) monoadducts and diadduct and the same adducts incorporated in DNA helices and the wavelength dependecies for the photocrossslinking of thymidine-HMT monoadducts in double-stranded helices. In Part II, The author will report some biological effects of psoralen-DNA adducts, i.e., the effects on double-stranded DNA stability, DNA structure, and transcription by E. coli and T7 RNA polymerases. Finally, The author will focus on the applications of psoralen-DNA photochemistry to investigation of protein-DNA interaction during transcription, which includes the interaction of E. coli and T7 RNA polymerases with DNA in elongation complexes arrested at specific psoralen-DNA adduct sites as revealed by DNase I footprinting experiments. 123 refs., 52 figs., 12 tabs.
17. DNA adduct measurements in zebra mussels, Dreissena polymorpha, Pallas
International Nuclear Information System (INIS)
18. Estimates of DNA strand breakage in bottlenose dolphin (Tursiops truncatus) leukocytes measured with the Comet and DNA diffusion assays
OpenAIRE
Adriana Díaz; Sandra Carro; Livia Santiago; Juan Estévez; Celia Guevara; Miriam Blanco; Laima Sánchez; Liena Sánchez; Nirka López; Danilo Cruz; Ronar López; Cuetara, Elizabeth B.; Jorge Luis Fuentes
2009-01-01
The analysis of DNA damage by mean of Comet or single cell gel electrophoresis (SCGE) assay has been commonly used to assess genotoxic impact in aquatic animals being able to detect exposure to low concentrations of contaminants in a wide range of species. The aims of this work were 1) to evaluate the usefulness of the Comet to detect DNA strand breakage in dolphin leukocytes, 2) to use the DNA diffusion assay to determine the amount of DNA strand breakage associated with apoptosis or necrosi...
19. Estimates of DNA strand breakage in bottlenose dolphin (Tursiops truncatus leukocytes measured with the Comet and DNA diffusion assays
Directory of Open Access Journals (Sweden)
2009-01-01
Full Text Available The analysis of DNA damage by mean of Comet or single cell gel electrophoresis (SCGE assay has been commonly used to assess genotoxic impact in aquatic animals being able to detect exposure to low concentrations of contaminants in a wide range of species. The aims of this work were 1 to evaluate the usefulness of the Comet to detect DNA strand breakage in dolphin leukocytes, 2 to use the DNA diffusion assay to determine the amount of DNA strand breakage associated with apoptosis or necrosis, and 3 to determine the proportion of DNA strand breakage that was unrelated to apoptosis and necrosis. Significant intra-individual variation was observed in all of the estimates of DNA damage. DNA strand breakage was overestimated because a considerable amount (~29% of the DNA damage was derived from apoptosis and necrosis. The remaining DNA damage in dolphin leukocytes was caused by factors unrelated to apoptosis and necrosis. These results indicate that the DNA diffusion assay is a complementary tool that can be used together with the Comet assay to assess DNA damage in bottlenose dolphins.
20. Estimates of DNA strand breakage in bottlenose dolphin (Tursiops truncatus) leukocytes measured with the Comet and DNA diffusion assays.
Science.gov (United States)
Díaz, Adriana; Carro, Sandra; Santiago, Livia; Estévez, Juan; Guevara, Celia; Blanco, Miriam; Sánchez, Laima; Sánchez, Liena; López, Nirka; Cruz, Danilo; López, Ronar; Cuetara, Elizabeth B; Fuentes, Jorge Luis
2009-04-01
The analysis of DNA damage by mean of Comet or single cell gel electrophoresis (SCGE) assay has been commonly used to assess genotoxic impact in aquatic animals being able to detect exposure to low concentrations of contaminants in a wide range of species. The aims of this work were 1) to evaluate the usefulness of the Comet to detect DNA strand breakage in dolphin leukocytes, 2) to use the DNA diffusion assay to determine the amount of DNA strand breakage associated with apoptosis or necrosis, and 3) to determine the proportion of DNA strand breakage that was unrelated to apoptosis and necrosis. Significant intra-individual variation was observed in all of the estimates of DNA damage. DNA strand breakage was overestimated because a considerable amount (~29%) of the DNA damage was derived from apoptosis and necrosis. The remaining DNA damage in dolphin leukocytes was caused by factors unrelated to apoptosis and necrosis. These results indicate that the DNA diffusion assay is a complementary tool that can be used together with the Comet assay to assess DNA damage in bottlenose dolphins. PMID:21637693
1. DNA strand breakage by 125I-decay in oligoDNA
International Nuclear Information System (INIS)
Full text: A double-stranded oligodeoxynucleotide containing 125I-dC in a defined location, with 5'- or 3'-32P-end-labelling of either strand, was used to investigate DNA strand breakage resulting from 125I decay. Samples of the 32P-end-labelled and 125I-dC containing oligoDNA were incubated in 20 mM phosphate buffer (PB), or PB + 2 M dimethylsulphoxide (DMSO) at 4 deg during 18-20 days. The 32P-end-labelled DNA fragments produced by 125I decays were separated on denaturing polyacrylamide gels, and the 3P activity in each fragment was determined by scintillation counting after elution from the gel. The fragment size distribution was then converted to a distribution of single stranded break probabilities at each nucleotide position. The results indicate that each 125I decay event produces at least one break in the 125I-dC containing strand, and causes breakage of the opposite strand in 75-80% of events. Thus, the double stranded break is produced by 125I decay with probability ∼0.8. Most of single stranded breaks (around 90%) occurred within 5-6 nucleotides of the 125I-dC, however DNA breaks were detected up to 18-20 nucleotides from the decay site. The average numbers of single stranded breaks per decay are 3.7 (PB) and 3.3 (PB+DMSO) in 125I-dC containing strand, and 1.5 (PB) and 1.3 (PB+DMSO) in the opposite strand. Deconvolution of strand break probabilities as a function of separation from the 125I, in terms of both distance (to target deoxyribosyl carbon atoms, in B-DNA) and nucleotide number, show that the latter is an important parameter for the shorter-range damage. This could indicate a role for attenuation/dissipation of damage through the stacked bases. In summary, the results represent a much more extensive set of data than available from earlier experiments on DNA breakage from l25I-decay, and may provide new mechanistic insights
2. Multiple DNA adducts in lymphocytes of smokers and nonsmokers determined by 32P-postlabeling analysis
International Nuclear Information System (INIS)
3. CARCINOGEN-DNA ADDUCTS: INTRODUCTION, LITERATURE SUMMARY, AND RECOMMENDATIONS
Science.gov (United States)
The report summarizes the literature concerning adducts formed by xenobiotics with DNA and/or protein and discusses their feasibility as a monitoring tool for use in exposure and risk assessment. The report is divided into three segments. The first segment provides an introductio...
4. Demonstration of DNA strand breakage induced by ultraviolet light
International Nuclear Information System (INIS)
The initial event in cellular carcinogenesis likely involves changes in the DNA at both the gene and chromosome levels, resulting from damage to the cell by outside agents. The authors have developed a visually striking experiment that demonstrates the damage to DNA caused by the common carcinogen, ultraviolet radiation. The protocol, suitable for undergraduate biochemistry and molecular biology courses, can be executed in one 3-4 hour laboratory period. Students become familiar with several common biochemical techniques, including electrophoretic separation of DNA molecules on horizontal agarose gels, measurement of microliter volumes, and the use of ultraviolet light sources. The experiment can be used to introduce diverse topics, including DNA biochemistry, reactive oxygen species, and cancer prevention
5. Analysis of length distribution of short DNA fragments induced by 7Li ions using the random-breakage model
Institute of Scientific and Technical Information of China (English)
KONG Fuquan; ZHAO Kui; ZHAN Yong; CAO Tianguang; NI Meinan; SUI Li; CAI Minghui; ZHUO Yizhong
2005-01-01
Deoxyribonucleic acid (DNA) is an important bio-macromolecule. DNA double strand breaks (DSBs) are considered to be the most important initial damage responsible for all biological effects induced by ionizing radiation. In this paper the length distribution of DNA fragments induced by 7Li ionizing radiation is fitted with the random breakage model. In this model, the parameter u is the average number of DSBs on every DNA molecule induced by ionizing radiation. The fitting result shows that the random breakage model cannot describe the distribution of DNA fragments in lower doses, while the random breakage model is in better accordance with the experimental data in higher doses. It is shown that the length distribution of DNA fragments has random statistical feature in higher doses. In this situation, the random breakage model looks like a model without any parameter since the u has specific physical meaning and can directly be obtained from experimental data.
6. Chemistry and Biology of Aflatoxin-DNA Adducts
Energy Technology Data Exchange (ETDEWEB)
Stone, Michael P.; Banerjee, Surajit; Brown, Kyle L.; Egli, Martin (Vanderbilt)
2012-03-27
Aspergillus flavus is a fungal contaminant of stored rice, wheat, corn, and other grainstuffs, and peanuts. This is of concern to human health because it produces the mycotoxin aflatoxin B{sub 1} (AFB{sub 1}), which is genotoxic and is implicated in the etiology of liver cancer. AFB{sub 1} is oxidized in vivo by cytochrome P450 to form aflatoxin B{sub 1} epoxide, which forms an N7-dG adduct (AFB{sub 1}-N7-dG) in DNA. The latter rearranges to a formamidopyrimidine (AFB{sub 1}-FAPY) derivative that equilibrates between {alpha} and {beta} anomers of the deoxyribose. In DNA, both the AFB{sub 1}-N7-dG and AFB{sub 1}-{beta}-FAPY adducts intercalate above the 5'-face of the damaged guanine. Each produces G {yields} T transversions in Escherichia coli, but the AFB{sub 1}-{beta}-FAPY adduct is more mutagenic. The Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) provides a model for understanding error-prone bypass of the AFB{sub 1}-N7-dG and AFB{sub 1}-{beta}-FAPY adducts. It bypasses the AFB{sub 1}-N7-dG adduct, but it conducts error-prone replication past the AFB{sub 1}-FAPY adduct, including mis-insertion of dATP, consistent with the G {yields} T mutations characteristic of AFB{sub 1} mutagenesis in E. coli. Crystallographic analyses of a series of binary and ternary complexes with the Dpo4 polymerase revealed differing orientations of the N7-C8 bond of the AFB{sub 1}-N7-dG adduct as compared to the N{sup 5}-C8 bond in the AFB{sub 1}-{beta}-FAPY adduct, and differential accommodation of the intercalated AFB{sub 1} moieties within the active site. These may modulate AFB{sub 1} lesion bypass by this polymerase.
7. 32P-postlabeling DNA adduct assay: cigarette smoke-induced dna adducts in the respiratory and nonrespiratory rat tissues. Book chapter
International Nuclear Information System (INIS)
An analysis of the tissue DNA adducts in rats by the sensitive (32)p-postlabeling assay showed one to eight detectable DNA adducts in lung, trachea, larynx, heart and bladder of the sham controls. Chronic exposure of animals to mainstream cigarette smoke showed a remarkable enhancement of most adducts in the lung and heart DNA. Since cigarette smoke contains several thousand chemicals and a few dozen of them are known or potential carcinogens, the difference between the DNA adducts of nasal and the other tissues may reflect the diversity of reactive constituents and their differential absorption in different tissues. In comparison to the lung DNA adducts, the adducts in nasal DNA were less hydrophobic. Identity of the predominant adducts was further investigated by comparison with several reference DNA adducts from 10 PAH and aromatic amines. Since some of these chemicals are present in cigarette smoke, the results suggest that these constituents of cigarette smoke may not be directly responsible for formation of DNA adducts in the lung and heart of the smoke-exposed animals
8. 37. Effect of Ni2O3 on DNA strand breakage and gene expression
Institute of Scientific and Technical Information of China (English)
2001-01-01
@@In order to study the possible mechanism of carcinogenisis by Nickel compound to find sensitive, specific monitoring index for nickel induced carcinogenesis, the methods based on single cell gel electrophoresis to assay (comet assay ) Ni2O3, -induced DNA breakage of human embryo lung cell. Arbitrary primed PCR in combination with methylation-sensitive restriction enzyme Hha Ⅱ digestion and bisulphate genomic conversion was used to analyse the CpG island methylation pattern variation of
9. Formation and persistence of arylamine DNA adducts in vivo.
OpenAIRE
Beland, F A; Kadlubar, F F
1985-01-01
Aromatic amines are urinary bladder carcinogens in man and induce tumors at a number of sites in experimental animals including the liver, mammary gland, intestine, and bladder. In this review, the particular pathways involved in the metabolic activation of aromatic amines are considered as well as the specific DNA adducts formed in target and nontarget tissue. Particular emphasis is placed on the following compounds: 1-naphthylamine, 2-naphthylamine, 4-aminobiphenyl, 4-acetylaminobiphenyl, 4...
10. Fast repair of oxidizing OH adducts of DNA by hydroxycinnamic acid derivatives. A pulse radiolytic study
International Nuclear Information System (INIS)
Using pulse radiolytic techniques, it has been demonstrated that the interactions of oxidizing OH adducts of DNA (ssDNA and dsDNA), polyA and polyG with hydroxycinnamic acid derivatives proceed via an electron transfer process (k=5-30x108 dm3 mol-1 s-1). In addition, the rates for fast repair of OH adducts of dAMP, polyA and DNA (ssDNA and dsDNA) are slower than the corresponding rates for the rest OH adducts of DNA constituents. The slower rates for repair of oxidizing OH adducts of dAMP may be the rate determining step during the interaction of hydroxycinnamic acid derivatives with OH adducts of DNA containing the varieties of OH adducts of DNA constituents
11. Chromosome breakages associated with 45S ribosomal DNA sequences in spotted snakehead fish Channa punctatus.
Science.gov (United States)
Singh, Mamta; Barman, Anindya Sundar
2013-01-01
It is well known that transcriptionally inactive rRNA genes are correlated with DNA hyper-methylation and histone hypo-methylation and there is clear evidence in humans that DNA and histone modification which alter chromatin structure are related to chromosome fragility. Very little is known about the biological cause of 45S rDNA fragility. In this report we characterized the chromosome breakage or gap associated with 45S rDNA in a fish species Channa punctatus. The rDNA mapping in C. punctatus, showed many chromosome breakages or gap formations, and all occurred exclusively in the 45S rDNA sites in anterior kidney cells. We observed that the number of chromosomes plus chromosome fragments was often more than the expected 32 in most cells. Total 67 % metaphase spread showed the expected or normal 32 chromosomes, while 33 % metaphase spread showed 33 and/or 34 chromosomes and/or chromosome fragments. The chromosome lesions observed in this study are very similar cytologically to that of fragile sites observed in human chromosomes. Possible causes for the spontaneous expression of fragile sites and their potential biological significance are also discussed in present report.
12. Cisplatin–DNA adducts inhibit translocation of the Ku subunits of DNA-PK
OpenAIRE
Turchi, John J.; Henkels, Karen M.; Zhou, Yun
2000-01-01
We have determined the effect of cisplatin–DNA damage on the ability of the DNA-dependent protein kinase (DNA-PK) to interact with duplex DNA molecules in vitro. The Ku DNA binding subunits of DNA-PK display a reduced ability to translocate on duplex DNA containing cisplatin–DNA adducts compared to control, undamaged duplex DNA. The decreased rates of translocation resulted in a decrease in the association of the p460 catalytic subunit of DNA-PK (DNA-PKcs) with the Ku–DNA complex. In addition...
13. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes
International Nuclear Information System (INIS)
14. Line narrowing spectroscopic studies of DNA-carcinogen adducts and DNA-dye complexes
Energy Technology Data Exchange (ETDEWEB)
Suh, Myungkoo
1995-12-06
15. Environmental, Dietary, Maternal, and Fetal Predictors of Bulky DNA Adducts in Cord Blood
DEFF Research Database (Denmark)
Pedersen, Marie; Mendez, Michelle A; Schoket, Bernadette;
2015-01-01
BACKGROUND: Bulky DNA adducts reflect genotoxic exposures, have been associated with lower birth weight, and may predict cancer risk. OBJECTIVE: We selected factors known or hypothesized to affect in utero adduct formation and repair and examined their associations with adduct levels in neonates....
16. Metabolites and DNA adduct formation from flavoenzyme-activated porfiromycin.
Science.gov (United States)
Pan, S S; Iracki, T
1988-08-01
Porfiromycin was reductively metabolized by NADPH cytochrome P-450 reductase and xanthine oxidase under anaerobic conditions. The production of metabolites varied with the pH and the contents of the reaction buffer. In Tris buffer, two major metabolites were produced at pH 7.5 and above, whereas one major metabolite was produced at pH 6.5. The three major metabolites were separated and isolated by HPLC. Identification by californium-252 plasma desorption mass spectrometry showed that the two major metabolites from pH 7.5 were (trans) and (cis)-forms of 7-amino-1-hydroxyl-2-methylaminomitosene and the major metabolite from pH 6.5 was 7-amino-2-methylaminomitosene. All three major metabolites showed substitutions at the C-1 position. DNA was alkylated readily by enzyme-activated porfiromycin. Digestion of porfiromycin-alkylated DNA by DNase, snake venom phosphodiesterase, and alkaline phosphatase resulted in an insoluble nuclease-resistant fraction and a soluble fraction. The nuclease-resistant fraction reflected a high content of cross-linked adducts. Upon HPLC analysis, the solubilized fraction contained two monofunctionally linked porfiromycin adducts and a possibly cross-linked dinucleotide. The major adduct was isolated by HPLC and identified by NMR, as N2-(2'-deoxyguanosyl)-7-amino-2-methylaminomitosene. The N2 position of deoxyguanosine appeared as the major monofunctional alkylating site for DNA alkylation by porfiromycin. Thus, mitomycin C and porfiromycin (which differs from mitomycin C only by the addition of a methyl group to the aziridine nitrogen) share the same enzymatic activating mechanism that leads to the formation of the same types of metabolites and the same specificity of DNA alkylation. PMID:3412325
17. High-performance liquid chromatography for analysis of 32P-Postlabeled DNA adducts
OpenAIRE
Zeisig, Magnus
1996-01-01
High-Performance Liquid Chromatography for Analysis of 32P-Postlabeled DNA Adducts Magnus Zeisig Center for Nutrition and Toxicology, Department of Bioscience at Novum, Karolinska Institutet, Novum, S-141 57 Huddinge, SwedenThe formation of DNA adducts, i.e. the covalent binding of chemicals and chemical groups to DNA,isbelieved to be an important step in chemical carciwg...
18. Human Biomonitoring of DNA Adducts by Ion Trap Multistage Mass Spectrometry.
Science.gov (United States)
Guo, Jingshu; Turesky, Robert J
2016-01-01
Humans are continuously exposed to hazardous chemicals in the environment. These chemicals or their electrophilic metabolites can form adducts with genomic DNA, which can lead to mutations and the initiation of cancer. The identification of DNA adducts is required for understanding exposure and the etiological role of a genotoxic chemical in cancer risk. The analytical chemist is confronted with a great challenge because the levels of DNA adducts generally occur at spectrometry has emerged as an important technique to screen for DNA adducts because of the high level sensitivity and selectivity, particularly when employing multi-stage scanning (MS(n) ). The product ion spectra provide rich structural information and corroborate the adduct identities even at trace levels in human tissues. Ion trap technology represents a significant advance in measuring DNA adducts in humans. © 2016 by John Wiley & Sons, Inc. PMID:27584705
19. Detection and characterization of human serum antibodies to polycyclic aromatic hydrocarbon diol-epoxide DNA adducts.
OpenAIRE
Newman, M J; Light, B A; Weston, A; Tollurud, D; Clark, J L; Mann, D L; Blackmon, J P; Harris, C C
1988-01-01
The presence of serum antibodies to the diol-epoxide DNA adducts of representative polycyclic aromatic hydrocarbons (PAH), chrysene, benz[a]anthracene and benzo[a]pyrene, was determined by ELISA using serum samples obtained from normal healthy individuals. Antibodies that reacted against PAH adducted-DNA, but not against PAH-adducted protein, were found in the serum of approximately 40% of the test individuals. Specificity analysis of the antibodies demonstrated that serological cross-reactio...
20. Inhibition of human Chk1 causes increased initiation of DNA replication, phosphorylation of ATR targets, and DNA breakage
DEFF Research Database (Denmark)
Syljuåsen, Randi G; Sørensen, Claus Storgaard; Hansen, Lasse Tengbjerg;
2005-01-01
-nuclear phosphorylation of histone H2AX, p53, Smc1, replication protein A, and Chk1 itself in human S-phase cells. These phosphorylations were inhibited by ATR siRNA and caffeine, but they occurred independently of ATM. Chk1 inhibition also caused an increased initiation of DNA replication, which was accompanied by...... increased amounts of nonextractable RPA protein, formation of single-stranded DNA, and induction of DNA strand breaks. Moreover, these responses were prevented by siRNA-mediated downregulation of Cdk2 or the replication initiation protein Cdc45, or by addition of the CDK inhibitor roscovitine. We propose...... that Chk1 is required during normal S phase to avoid aberrantly increased initiation of DNA replication, thereby protecting against DNA breakage. These results may help explain why Chk1 is an essential kinase and should be taken into account when drugs to inhibit this kinase are considered for use in...
1. Sophoridinol derivative 05D induces tumor cells apoptosis by topoisomerase1-mediated DNA breakage
Directory of Open Access Journals (Sweden)
Zhao W
2016-05-01
Full Text Available Wuli Zhao, Caixia Zhang, Chongwen Bi, Cheng Ye, Danqing Song, Xiujun Liu, Rongguang Shao Key Laboratory of Antibiotic Bioengineering, Ministry of Health, Laboratory of Oncology, Institute of Medicinal Biotechnology, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, People’s Republic of China Abstract: Sophoridine is a quinolizidine natural product of Sophora alopecuroides and has been applied for treatment of malignant trophoblastic tumors. Although characterized by low toxicity, the limited-spectrum antitumor activity hinders its further applications. 05D, a derivative of sophoridine, exhibits a better anticancer activity on diverse cancer cells, including solid tumors, and hematologic malignancy. It could inhibit topoisomerase 1 (top1 activity by stabilizing DNA–top1 complex and induce mitochondria-mediated apoptosis by promoting DNA single- and double-strand breakage mediated by top1. Also, 05D induced HCT116 cells arrest at G1 phase by inactivating CDK2/CDK4–Rb–E2F and cyclinD1–CDK4–p21 checkpoint signal pathways. 05D suppressed the ataxia telangiectasia mutated (ATM and ATM and Rad3-related (ATR activation and decreased 53BP level, which contributed to DNA damage repair, suggesting that the novel compound 05D might be helpful to improve the antitumor activity of DNA damaging agent by repressing ATM and ATR activation and 53BP level. In addition, the priorities in molecular traits and druggability, such as a simple structure and formulation for oral administration, further prove 05D to be a promising targeting topoisomerase agent. Keywords: topoisomerase inhibitor, topoisomerase 1, DNA breakage, sophoridinol, anticancer, apoptosis, cell cycle
2. Liquid chromatography-thermospray mass spectrometry of DNA adducts formed with mitomycin C, porfiromycin and thiotepa.
Science.gov (United States)
Musser, S M; Pan, S S; Callery, P S
1989-07-14
High-performance liquid chromatography (HPLC) and thermospray mass spectrometry were combined for the analysis of DNA adducts formed from the interaction of the anticancer drugs mitomycin C, porfiromycin and thiotepa with calf thymus DNA. The adducts formed from reaction of mitomycin C and porfiromycin with DNA were separated from unmodified nucleosides by HPLC on a C18 column and identified by thermospray mass spectrometry. Thiotepa DNA adducts readily depurinated from DNA and were chromatographed and identified by thermospray liquid chromatography-mass spectrometry as the modified bases without the ribose moiety attached. The utility of thermospray mass spectrometry for the identification of microgram quantities of nucleoside adducts and depurinated base adducts of these anticancer drugs was demonstrated. PMID:2504760
3. Immunochemical detection of sulfur mustard-adducts with DNA and proteins: Exploratory research on adducts with proteins
NARCIS (Netherlands)
Schans, G.P. van der; Noort, D.; Mars-Groenendijk, R.H.; Dijk-Knijnenburg, H.C.M. van; Fidder, A.; Jong, L.P.A. de; Benschop, H.P.
2000-01-01
We have developed two modes of a standard operating procedure (SOP) for immunochemical detection of sulfur mustard adducts to DNA in human blood and skin. In the shortened mode data could be generated within 9 h after in vitro exposure of human blood to > 1 μM sulfur mustard. The sensitive mode allo
4. Seasonal variations in levels of DNA adducts and X-spots in human populations living in different parts of Poland.
OpenAIRE
Grzybowska, E; Hemminki, K; Choraźy, M
1993-01-01
White blood cell DNA adducts were measured in coke oven workers, in residents from the area next to the coke oven in Silesia, Poland (highly industrialized region), and in residents from the rural area of Poland using the 32P-postlabeling technique. This method detected aromatic adducts including adducts formed by polycyclic aromatic hydrocarbons (PAHs). Highest levels of adducts in DNA were seen in the group of coke battery workers (6.9 adducts/10(8) nucleotides). Seasonal variations in leve...
5. How quantum entanglement in DNA synchronizes double-strand breakage by type II restriction endonucleases.
Science.gov (United States)
Kurian, P; Dunston, G; Lindesay, J
2016-02-21
Macroscopic quantum effects in living systems have been studied widely in pursuit of fundamental explanations for biological energy transport and sensing. While it is known that type II endonucleases, the largest class of restriction enzymes, induce DNA double-strand breaks by attacking phosphodiester bonds, the mechanism by which simultaneous cutting is coordinated between the catalytic centers remains unclear. We propose a quantum mechanical model for collective electronic behavior in the DNA helix, where dipole-dipole oscillations are quantized through boundary conditions imposed by the enzyme. Zero-point modes of coherent oscillations would provide the energy required for double-strand breakage. Such quanta may be preserved in the presence of thermal noise by the enzyme's displacement of water surrounding the DNA recognition sequence. The enzyme thus serves as a decoherence shield. Palindromic mirror symmetry of the enzyme-DNA complex should conserve parity, because symmetric bond-breaking ceases when the symmetry of the complex is violated or when physiological parameters are perturbed from optima. Persistent correlations in DNA across longer spatial separations-a possible signature of quantum entanglement-may be explained by such a mechanism.
6. A method of calculating initial DNA strand breakage following the decay of incorporated 125I
International Nuclear Information System (INIS)
Two sources of individual Auger electron spectra and an electron track code were used with a simple model of the DNA to successfully simulate single-strand DNA breakage measured by Martin and Haseltine (1981). Conditions of the calculation were then extended to examine patterns of single-strand breaks in both strands of the DNA duplex to score double-strand breaks. Five types of break were scored. The total number of double-strand breaks (dsb) per decay at the site of the decay was 0.90 and 0.65 for the different Auger electron spectra. It was shown that for mammalian cells an additional source of double-strand breaks from low LET radiation added approximately 0.17 dsb/decay to each, giving a final total of 1.07 and 0.85 dsb/decay for mammalian cells depending on electron spectrum. It is shown that energy deposition in the DNA from the iodine decay is very complex, with a broad range of energy depositions and products. Even for a particular energy deposited in the DNA different types of strand-break are produced. These are identified and their probabilities calculated. (author)
7. Binding of Multiple Rap1 Proteins Stimulates Chromosome Breakage Induction during DNA Replication.
Directory of Open Access Journals (Sweden)
Greicy H Goto
2015-08-01
Full Text Available Telomeres, the ends of linear eukaryotic chromosomes, have a specialized chromatin structure that provides a stable chromosomal terminus. In budding yeast Rap1 protein binds to telomeric TG repeat and negatively regulates telomere length. Here we show that binding of multiple Rap1 proteins stimulates DNA double-stranded break (DSB induction at both telomeric and non-telomeric regions. Consistent with the role of DSB induction, Rap1 stimulates nearby recombination events in a dosage-dependent manner. Rap1 recruits Rif1 and Rif2 to telomeres, but neither Rif1 nor Rif2 is required for DSB induction. Rap1-mediated DSB induction involves replication fork progression but inactivation of checkpoint kinase Mec1 does not affect DSB induction. Rap1 tethering shortens artificially elongated telomeres in parallel with telomerase inhibition, and this telomere shortening does not require homologous recombination. These results suggest that Rap1 contributes to telomere homeostasis by promoting chromosome breakage.
8. Specific plant DNA adducts as molecular biomarkers of genotoxic atmospheric environments.
Science.gov (United States)
Weber-Lotfi, F; Obrecht-Pflumio, S; Guillemaut, P; Kleinpeter, J; Dietrich, A
2005-03-01
The general purpose of this study was to determine whether the formation of DNA addition products ('adducts') in plants could be a valuable biomarker of genotoxic air pollution. Plants from several species were exposed to ambient atmosphere at urban and suburban sites representative of different environmental conditions. The levels of NO2 and of the quantitatively major genotoxic air pollutants benzene, toluene, and xylene were monitored in parallel with plant exposure. DNA adducts were measured in bean (Phaseolus vulgaris), rye-grass (Lolium perenne), and tobacco (Nicotiana tabacum) seedlings by means of the [32P]-postlabeling method. Whereas, no correlation was found between the levels of the major genotoxic air pollutants and the total amounts of DNA adducts, individual analyses revealed site-specific and plant species-specific adduct responses, both at the qualitative and quantitative level. Among these, the amount of a specific rye-grass DNA adduct (rgs1) correlated with benzene/toluene/xylene levels above a threshold. For further characterization, rye-grass seedlings were treated in controlled conditions with benzene, toluene, xylene or their derivatives. On the other hand, in vitro DNA adduct formation assays were developed involving benzene, toluene, xylene, or their derivatives, and plant microsomes or purified peroxidase. Although in some cases, these approaches produced specific adduct responses, they failed to generate the rgs1 DNA adduct, which appeared to be characteristic for on-site test-plant exposure. Our studies have thus identified an interesting candidate for further analysis of environmental biomarkers of genotoxicity.
9. Environmental air pollution and DNA adducts in Copenhagen bus drivers - effect of GSTM1 and NAT2 genotypes on adduct level
DEFF Research Database (Denmark)
Nielsen, Per Sabro; de Pater, Nettie; Okkels, Henrik;
1996-01-01
(smokers and non-smokers). PAH-DNA adducts were determined by 32P-postlabelling with the butanol enrichment procedure. The bus drivers answered a comprehensive questionnaire on passive smoking, residential area, diet and other potential confounding variables. A significantly higher adduct level...... rural controls (0.074 fmol/microg DNA, n = 60, P smoking and diet. The effect of the metabolizing enzymes, GSTM1 and NAT2, on adduct levels was investigated. No statistically significant effects...
10. Isolation, identification, and assay of [3H]-porfiromycin adducts of EMT6 mouse mammary tumor cell DNA: effects of hypoxia and dicumarol on adduct patterns.
Science.gov (United States)
Tomasz, M; Hughes, C S; Chowdary, D; Keyes, S R; Lipman, R; Sartorelli, A C; Rockwell, S
1991-07-01
11. Inactivation of E. Coli cell viability and DNA Photo-breakage by Pulsed Nitrogen Laser Radiation
International Nuclear Information System (INIS)
The mutagenic and lethal effect of nitrogen laser radiation: 337.1 nm wave length, 1.5 millijoul pulse energy, 10 nanosecond pulse with and pulse repetition rate range from 1 to 50 Pulse/ second was evaluated on E. Coli cells. Results indicated that irradiation of E. coli JMP39 with pulse repetition of 8 , 16 , 32 pulse/sec, for 1, 5 , 10, 25 min respectively led to a significant decrease in cell count proportional to irradiation dose with significant increase in lacmutation frequency accompanied with some mutations in pattern of antibiotic resistance. The effect of nitrogen laser on the genomic content of the strain JMP39 was also studied by irradiating the total DNA with 30 pulse/second for 1 ,5, 15 , 30 min then subjected to both agarose gel electrophoresis and scanning spectrophotometry. The first technique revealed to DNA photo breakage and significant decrease in DNA absorbency was noticed by scanning spectrophotometry. This could be attributed to photo-decomposition resulted from multi-photo-excitation of UV-Laser pulses
12. DNA adducts in marine mussel and fresh water fishes living in polluted and unpolluted environments
International Nuclear Information System (INIS)
32P-postlabeling analysis of DNA adducts in the digestive gland of marine mussel Mytilus galloprovincialis from polluted and unpolluted sites near Rovinj, Northern Adriatic, revealed that majority of adducts are caused by natural environmental factors rather than by man-made chemicals. The only pollutant-specific adducts were observed in a mussel exposed to seawater experimentally polluted with aminofluorene, and in a population of mussel living at a site heavily polluted with a waste waters of an oil refinery. Fresh water fish species Leuciscus cephalus, Barbus barbus, Abramis brama and Rutilus pigus virgo living in a polluted Sava River, Yugoslavia, or in its unpolluted tributary Korana River, have induced in their livers qualitatively identical and quantitatively similar DNA adducts. These DNA adducts had a species-specific patterns and their appearance was seasonally-dependent
13. 32P analysis of DNA adducts in tissues of benzene-treated rats
International Nuclear Information System (INIS)
14. Comparison of DNA adducts from exposure to complex mixtures in various human tissues and experimental systems
OpenAIRE
Lewtas, Joellen; Mumford, Judy; Everson, Richard B; Hulka, Barbara; Wilcosky, Tim; Kozumbo, Walter; Thompson, Claudia; George, Michael; Dobiáš, Lubomir; Šrám, Radim; Li, Xueming; Gallagher, Jane
1993-01-01
DNA adducts derived from complex mixtures of polycyclic aromatic compounds emitted from tobacco smoke are compared to industrial pollution sources (e.g., coke ovens and aluminum smelters), smoky coal burning, and urban air pollution. Exposures to coke oven emissions and smoky coal, both potent rodent skin tumor initiators and lung carcinogens in humans, result in high levels of DNA adducts compared to tobacco smoke in the in vitro calf thymus DNA model system, in cultured lymphocytes, and in ...
15. DNA adducts as a measure of lung cancer risk in humans exposed to polycyclic aromatic hydrocarbons.
OpenAIRE
Kriek, E; van Schooten, F.J.; Hillebrand, M J; van Leeuwen, F E; Den Engelse, L; De Looff, A J; Dijkmans, A P
1993-01-01
Workers in the coking, foundry, and aluminum industry can be exposed to high concentrations of polycyclic aromatic hydrocarbons (PAHs) and are at increased risk for lung cancer, as are cigarette smokers. In recent years several studies on workers in the foundry and coking industries have been reported. In these studies, white blood cell(WBC) DNA was used for analysis of PAH-DNA adducts. Theoretically, DNA adduct formation is a more relevant biological parameter for assessing exposure risk tha...
Science.gov (United States)
Airoldi, Luisa; Orsi, Federica; Magagnotti, Cinzia; Coda, Renato; Randone, Donato; Casetta, Giovanni; Peluso, Marco; Hautefeuille, Agnes; Malaveille, Christian; Vineis, Paolo
2002-05-01
17. Exposure of bus and taxi drivers to urban air pollutants as measured by DNA and protein adducts
DEFF Research Database (Denmark)
Hemminki, K.; Zhang, L.F.; Krüger, J.;
1994-01-01
Urinary 1-hydroxypyrene, lymphocyte DNA adducts, serum protein-bound PAH and hemoglobin-bound alkene adducts were analysed from 4 groups of non-smoking men: urban and suburban bus drivers, taxi drivers and suburban controls. The only differences between the groups were in DNA adducts between subu...
18. Inhibition of nitrobenzene-induced DNA and hemoglobin adductions by dietary constituents
Energy Technology Data Exchange (ETDEWEB)
Li Hongli; Cheng Yan; Wang Haifang; Sun Hongfang; Liu Yuanfang E-mail: yliu@pku.edu.cn; Liu Kexin; Peng Shixiang
2003-03-01
Nitrobenzene (NB), a widely used industrial chemical, is a likely human carcinogen. Many dietary constituents can suppress the DNA-adduction, acting as the inhibitors of cancer. In this study, we investigated the inhibitory effects of vitamin C (VC), vitamin E (VE), tea polyphenols (TP), garlic squeeze, curcumin, and grapestone extract on NB-DNA and NB-hemoglobin (Hb) adductions in mice using an ultrasensitive method of accelerator mass spectrometry (AMS) with {sup 14}C-labelled nitrobenzene. All of these dietary constituents showed their inhibitory effects on DNA or Hb adduction. VC, VE, TP and grapestone extract could efficaciously inhibit the adductions by 33-50%, and all of these six agents could inhibit Hb adduction by 30-64%. We also investigated resveratrol, curcumin, VC and VE as inhibitors of NB-DNA adduction in vitro using liquid scintillation counting technique. These agents in the presence of NADPH and S9 components also pronouncedly blocked DNA adduction in a dose-dependent profile. Our study suggests that these seven constituents may interrupt the process of NB-induced chemical carcinogenesis.
19. Detection and characterization of human serum antibodies to polycyclic aromatic hydrocarbon diol-epoxide DNA adducts
Energy Technology Data Exchange (ETDEWEB)
Newman, M.J.; Light, B.A.; Weston, A.; Tollurud, D.; Clark, J.L.; Mann, D.L.; Blackmon, J.P.; Harris, C.C.
1988-07-01
The presence of serum antibodies to the diol-epoxide DNA adducts of representative polycyclic aromatic hydrocarbons (PAH), chrysene, benz(a)anthracene and benzo(a)pyrene, was determined by ELISA using serum samples obtained from normal healthy individuals. Antibodies that reacted against PAH adducted-DNA, but not against PAH-adducted protein, were found in the serum of approximately 40% of the test individuals. Specificity analysis of the antibodies demonstrated that serological cross-reactions between the benzo(a)pyrene and the chrysene diol-epoxide adducts were present. Similar cross-reactivity between the benz(a)anthracene and the chrysene adducts was observed. Sera containing antibodies that were apparently specific for each of the three PAH-DNA adducts were also identified. The presence of antibodies to PAH-DNA adducts indicates both past exposure to these carcinogenic PAH and their metabolic activation to the DNA damaging metabolites. These antibodies may prove to be useful in both retrospective and prospective epidemiological studies of various diseases associated with PAH exposure.
20. Phosphoramide mustard exposure induces DNA adduct formation and the DNA damage repair response in rat ovarian granulosa cells
Energy Technology Data Exchange (ETDEWEB)
Ganesan, Shanthi, E-mail: shanthig@iastate.edu; Keating, Aileen F., E-mail: akeating@iastate.edu
2015-02-01
Phosphoramide mustard (PM), the ovotoxic metabolite of the anti-cancer agent cyclophosphamide (CPA), destroys rapidly dividing cells by forming NOR-G-OH, NOR-G and G-NOR-G adducts with DNA, potentially leading to DNA damage. A previous study demonstrated that PM induces ovarian DNA damage in rat ovaries. To investigate whether PM induces DNA adduct formation, DNA damage and induction of the DNA repair response, rat spontaneously immortalized granulosa cells (SIGCs) were treated with vehicle control (1% DMSO) or PM (3 or 6 μM) for 24 or 48 h. Cell viability was reduced (P < 0.05) after 48 h of exposure to 3 or 6 μM PM. The NOR-G-OH DNA adduct was detected after 24 h of 6 μM PM exposure, while the more cytotoxic G-NOR-G DNA adduct was formed after 48 h by exposure to both PM concentrations. Phosphorylated H2AX (γH2AX), a marker of DNA double stranded break occurrence, was also increased by PM exposure, coincident with DNA adduct formation. Additionally, induction of genes (Atm, Parp1, Prkdc, Xrcc6, and Brca1) and proteins (ATM, γH2AX, PARP-1, PRKDC, XRCC6, and BRCA1) involved in DNA repair were observed in both a time- and dose-dependent manner. These data support that PM induces DNA adduct formation in ovarian granulosa cells, induces DNA damage and elicits the ovarian DNA repair response. - Highlights: • PM forms ovarian DNA adducts. • DNA damage marker γH2AX increased by PM exposure. • PM induces ovarian DNA double strand break repair.
1. Sperm DNA adducts impair fertilization during ICSI but not during IVF.
Directory of Open Access Journals (Sweden)
Piotr Widłak
2008-04-01
Full Text Available Many studies emphasize the influence of the status of spermatozoal nucleus on fertilization, mainly with regard to DNA fragmentation. This study was undertaken to analyze the influence of DNA adducts content in spermatozoa on fertilization during assisted reproduction. Ovarian hyperstimulation, oocyte retrieval and laboratory work-up in 61 IVF (in vitro fertilization and 118 ICSI (intracytoplasmic sperm injection first cycles were performed according to the same protocol. Semen analysis was made according to WHO Manual (1999. DNA adducts assay in spermatozoa was performed by 32Ppostlabeling method. In total 331 fertilizable oocytes were obtained during IVF and 659 during ICSI. Both groups differed significantly by sperm count, motility and morphology but not by the concentration of DNA adducts in spermatozoa (0.0306 +/- 0.0217 in IVF versus 0.0373 +/- 0.0321 in ICSI. The fertilization rate during IVF was significantly influenced by sperm count (p=0.0002 and motility (p=0.0037 but not by DNA adducts concentration (p=0.30528, whereas during ICSI was positively influenced by sperm motility (p=0.04669 and negatively by DNA adducts concentration (p=0.00796. DNA adducts concentration in spermatozoa significantly negatively influences fertilization rate during ICSI, but not during IVF.
2. Recent progress in quantitative analysis of DNA adducts of nephrotoxin aristolochic acid
Institute of Scientific and Technical Information of China (English)
2009-01-01
Aristolochic acid (AA), a mixture of structure-related nitrophenanthrene carboxylic acid derivatives derived from Aristolochia spp, is associated with nephrotoxin and carcinogen. AA-DNA adducts induced by reductive metabolic activation of AA were detected in tissues of animals and in patients exposed to AA. The DNA adducts were generally used as biomarkers in toxicological study of AA. In this short review, quantitative analysis of AA-DNA adducts in various in vitro and in vivo systems by using 32P-postlabelling assay, HPLC-UV, HPLC-radiation monitor, HPLC-FLD, HPLC-ESI/MS and UPLC-MS/MS methods is discussed. The distribution of AA-DNA adducts in various tissues is also summarized.
3. DNA adducts in target and nontarget tissues of 3,2'-dimethyl-4-aminobiphenyl in rats.
OpenAIRE
Shirai, T; Tada, M; Kojima, M; Hasegawa, R.; Masui, T.; Ito, N.
1994-01-01
3,2'-Dimethyl-4-aminobiphenyl (DMAB) is a potent carcinogenic aromatic amine which demonstrates multiorgan tropism in rats. Using polyclonal antibodies against DMAB-DNA adducts, an immunohistochemical procedure as well as an ELISA were applied to investigate the relationship between DMAB-DNA adduct formation and tumorigenicity. Dose-related nuclear staining was observed 24 hr after application of the carcinogen but specificity in terms of sites of tumor development was lacking. No observable ...
4. Genetic ecotoxicology IV: survival and DNA strand breakage is dependent on genotype in radionuclide-exposed mosquitofish
Energy Technology Data Exchange (ETDEWEB)
Theodorakis, C.W. [Texas A and M University, Department of Wildlife and Fisheries Sciences, College Station, TX 77843-2258 (United States); Elbl, T. [University of Pennsylvania, Department of Cell and Molecular Biology, Philadelphia, PA 19102 (United States); Shugart, L.R. [L.R. Shugart and Associates, Oak Ridge, TN 37831 (United States)
1999-05-01
Western mosquitofish (Gambusia affinis) were caged in situ in a radioactively-contaminated pond in order to determine if survival and amount of DNA strand breakage were dependent on genotype. Genotypes of fish were determined using the randomly amplified polymorphic (RAPD) technique, and DNA strand breakage was determined using agarose gel electrophoresis. This study is a continuation of research undertaken at the Oak Ridge National Laboratory, which examined the effects of radionuclide contamination on the population genetic structure of mosquitofish. The previous research found 17 RAPD markers that were present at a higher frequency in contaminated than in reference populations ('contaminant-indicative bands'), and fish from contaminated sites which possessed these markers had higher fecundity and fewer strand breaks than fish which did not. One of the contaminated populations (Pond 3513) was colonized from one of the reference populations (Crystal Springs) in 1977. In the present study, fish were obtained from Crystal Springs and an additional reference site, and caged in Pond 3513. The percent survival and amount of DNA strand breakage were then determined for fish with and without the contaminant-indicative markers. When Crystal Springs fish were caged in Pond 3513, it was found that the genotypic distribution of the survivors was more similar to the native Pond 3513 population than to the Crystal Springs population. Furthermore, for nine of the contaminant-indicative markers, the percent survival was greater for fish which possessed these markers than for fish which did not. For five of these markers, fish which possessed them had higher DNA integrity (fewer strand breaks) than fish which did not. These data indicate that probability of survival and degree of DNA strand breakage in radionuclide-exposed mosquitofish are dependent on RAPD genotype, and are consistent with the hypothesis that the contaminant-indicative RAPD bands are markers of loci
5. The use of an artificial nucleotide for polymerase-based recognition of carcinogenic O6-alkylguanine DNA adducts.
Science.gov (United States)
Wyss, Laura A; Nilforoushan, Arman; Williams, David M; Marx, Andreas; Sturla, Shana J
2016-08-19
6. DNA adducts and cancer risk in prospective studies: a pooled analysis and a meta-analysis
DEFF Research Database (Denmark)
Veglia, Fabrizio; Loft, Steffen; Matullo, Giuseppe;
2008-01-01
Bulky DNA adducts are biomarkers of exposure to aromatic compounds and of the ability of the individual to metabolically activate carcinogens and to repair DNA damage. Their ability to predict cancer onset is uncertain. We have performed a pooled analysis of three prospective studies on cancer risk...... in which bulky DNA adducts have been measured in blood samples collected from healthy subjects (N = 1947; average follow-up 51-137 months). In addition, we have performed a meta-analysis by identifying all articles on the same subject published up to the end of 2006, including case-control studies....... In the pooled analysis, a weakly statistically significant increase in the risk of lung cancer was apparent (14% per unit standard deviation change in adduct levels, 95% confidence interval 1-28%; using the weighted mean difference method, 0.15 SD, units higher adducts in cases than in controls...
7. FBH1 promotes DNA double-strand breakage and apoptosis in response to DNA replication stress.
Science.gov (United States)
Jeong, Yeon-Tae; Rossi, Mario; Cermak, Lukas; Saraf, Anita; Florens, Laurence; Washburn, Michael P; Sung, Patrick; Schildkraut, Carl L; Schildkraut, Carl; Pagano, Michele
2013-01-21
Proper resolution of stalled replication forks is essential for genome stability. Purification of FBH1, a UvrD DNA helicase, identified a physical interaction with replication protein A (RPA), the major cellular single-stranded DNA (ssDNA)-binding protein complex. Compared with control cells, FBH1-depleted cells responded to replication stress with considerably fewer double-strand breaks (DSBs), a dramatic reduction in the activation of ATM and DNA-PK and phosphorylation of RPA2 and p53, and a significantly increased rate of survival. A minor decrease in ssDNA levels was also observed. All these phenotypes were rescued by wild-type FBH1, but not a FBH1 mutant lacking helicase activity. FBH1 depletion had no effect on other forms of genotoxic stress in which DSBs form by means that do not require ssDNA intermediates. In response to catastrophic genotoxic stress, apoptosis prevents the persistence and propagation of DNA lesions. Our findings show that FBH1 helicase activity is required for the efficient induction of DSBs and apoptosis specifically in response to DNA replication stress. PMID:23319600
8. Spi-1/PU.1 oncogene accelerates DNA replication fork elongation and promotes genetic instability in the absence of DNA breakage.
Science.gov (United States)
Rimmelé, Pauline; Komatsu, Jun; Hupé, Philippe; Roulin, Christophe; Barillot, Emmanuel; Dutreix, Marie; Conseiller, Emmanuel; Bensimon, Aaron; Moreau-Gachelin, Françoise; Guillouf, Christel
2010-09-01
The multistage process of cancer formation is driven by the progressive acquisition of somatic mutations. Replication stress creates genomic instability in mammals. Using a well-defined multistep leukemia model driven by Spi-1/PU.1 overexpression in the mouse and Spi-1/PU.1-overexpressing human leukemic cells, we investigated the relationship between DNA replication and cancer progression. Here, using DNA molecular combing and flow cytometry methods, we show that Spi-1 increases the speed of replication by acting specifically on elongation rather than enhancing origin firing. This shortens the S-phase duration. Combining data from Spi-1 knockdown in murine cells with Spi-1 overexpression in human cells, we provide evidence that inappropriate Spi-1 expression is directly responsible for the replication alteration observed. Importantly, the acceleration of replication progression coincides with an increase in the frequency of genomic mutations without inducing DNA breakage. Thus, we propose that the hitherto unsuspected role for spi-1 oncogene in promoting replication elongation and genomic mutation promotes blastic progression during leukemic development.
9. Transplatin-conjugated triplex-forming oligonucleotides form adducts with both strands of DNA.
Science.gov (United States)
Campbell, Meghan A; Miller, Paul S
2009-12-01
10. DNA isolation and sample preparation for quantification of adduct levels by accelerator mass spectrometry.
Science.gov (United States)
Dingley, Karen H; Ubick, Esther A; Vogel, John S; Ognibene, Ted J; Malfatti, Michael A; Kulp, Kristen; Haack, Kurt W
2014-01-01
Accelerator mass spectrometry (AMS) is a highly sensitive technique used for the quantification of adducts following exposure to carbon-14- or tritium-labeled chemicals, with detection limits in the range of one adduct per 10(11)-10(12) nucleotides. The protocol described in this chapter provides an optimal method for isolating and preparing DNA samples to measure isotope-labeled DNA adducts by AMS. When preparing samples, special precautions must be taken to avoid cross-contamination of isotope among samples and produce a sample that is compatible with AMS. The DNA isolation method described is based upon digestion of tissue with proteinase K, followed by extraction of DNA using Qiagen isolation columns. The extracted DNA is precipitated with isopropanol, washed repeatedly with 70 % ethanol to remove salt, and then dissolved in water. DNA samples are then converted to graphite or titanium hydride and the isotope content measured by AMS to quantify adduct levels. This method has been used to reliably generate good yields of uncontaminated, pure DNA from animal and human tissues for analysis of adduct levels.
11. DNA strand breakage by 125I decay: Plasmid DNA in dilute aqueous solution
International Nuclear Information System (INIS)
The question of the extent of damage to DNA, in particular double strand breaks, that can be caused by the decay of the Auger emitter 125I when it is covalently incorporated into the DNA requires resolution. In particular, experiments with plasmid DNA reported by Linz and Stoecklin would seem to indicate that the range of effect extends over the whole length of the molecule (a few 1,000's base pairs (bp)) in contrast to the generally accepted view that the decay is very localized (i.e. effect over a few 10's bp). This raises the question of whether a long range energy migration process is operative in DNA or whether the fragmentation can be accounted for by free radical diffusion. The authors report here experiments to help resolve this issue by investigating and trying to eliminate the possible effects of free radicals. The results which are broadly consistent with the findings of Linz and Stoecklin indicate that long-range damage in labeled DNA in aqueous solution is due to effects of free radicals. The authors confirm the high-LET nature of the 125I decay
12. Organocatalytic removal of formaldehyde adducts from RNA and DNA bases
Science.gov (United States)
Karmakar, Saswata; Harcourt, Emily M.; Hewings, David S.; Lovejoy, Alexander F.; Kurtz, David M.; Ehrenschwender, Thomas; Barandun, Luzi J.; Roost, Caroline; Alizadeh, Ash A.; Kool, Eric T.
2015-09-01
Formaldehyde is universally used to fix tissue specimens, where it forms hemiaminal and aminal adducts with biomolecules, hindering the ability to retrieve molecular information. Common methods for removing these adducts involve extended heating, which can cause extensive degradation of nucleic acids, particularly RNA. Here, we show that water-soluble bifunctional catalysts (anthranilates and phosphanilates) speed the reversal of formaldehyde adducts of mononucleotides over standard buffers. Studies with formaldehyde-treated RNA oligonucleotides show that the catalysts enhance adduct removal, restoring unmodified RNA at 37 °C even when extensively modified, while avoiding the high temperatures that promote RNA degradation. Experiments with formalin-fixed, paraffin-embedded cell samples show that the catalysis is compatible with common RNA extraction protocols, with detectable RNA yields increased by 1.5-2.4-fold using a catalyst under optimized conditions and by 7-25-fold compared with a commercial kit. Such catalytic strategies show promise for general use in reversing formaldehyde adducts in clinical specimens.
Science.gov (United States)
Martone, T; Airoldi, L; Magagnotti, C; Coda, R; Randone, D; Malaveille, C; Avanzi, G; Merletti, F; Hautefeuille, A; Vineis, P
1998-02-01
Epidemiologic studies have suggested that smokers of air-cured tobacco (rich in arylamines) are at higher risk of bladder cancer than smokers of flue-cured tobacco. The risk has been shown to be modulated by the N-acetyltransferase genotype. We analyzed the biopsies of 45 patients with bladder cancer. p53 mutations were sought by direct sequencing, and 4-aminobiphenyl-DNA adducts were measured by negative ion gas chromatography-mass spectrometry. 4-Aminobiphenyl-DNA adducts were higher in smokers of air-cured tobacco and in current smokers, but no relationship with the number of cigarettes smoked was found. Adducts were higher in more advanced histologic grades of tumors. No pattern was evident for p53 mutations. Seven of 9 mutations occurred in grade 3 tumors. No association was found between 4-ABP adducts and GSTM1 or NAT2 genetic polymorphisms. PMID:9466649
14. Simultaneous Detection of Multiple DNA Adducts in Human Lung Samples by Isotope-Dilution UPLC-MS/MS
OpenAIRE
Monien, Bernhard H.; Schumacher, Fabian; Herrmann, Kristin; Glatt, Hansruedi; Turesky, Robert J.; Chesné, Christophe
2014-01-01
Recent studies have demonstrated that various DNA adducts can be detected in human tissues and fluids using liquid chromatography connected to tandem mass spectrometry (LC-MS/MS). However, the utility of a single DNA adduct as a biomarker in risk assessment is debatable because humans are exposed to many genotoxicants. We established a method to measure DNA adducts derived from 16 ubiquitous genotoxicants and developed an analytical technique for their simultaneous quantification by ultra per...
15. The N(2)-Furfuryl-deoxyguanosine Adduct Does Not Alter the Structure of B-DNA.
Science.gov (United States)
Ghodke, Pratibha P; Gore, Kiran R; Harikrishna, S; Samanta, Biswajit; Kottur, Jithesh; Nair, Deepak T; Pradeepkumar, P I
2016-01-15
N(2)-Furfuryl-deoxyguanosine (fdG) is carcinogenic DNA adduct that originates from furfuryl alcohol. It is also a stable structural mimic of the damage induced by the nitrofurazone family of antibiotics. For the structural and functional studies of this model N(2)-dG adduct, reliable and rapid access to fdG-modified DNAs are warranted. Toward this end, here we report the synthesis of fdG-modified DNAs using phosphoramidite chemistry involving only three steps. The functional integrity of the modified DNA has been verified by primer extension studies with DNA polymerases I and IV from E. coli. Introduction of fdG into a DNA duplex decreases the Tm by ∼1.6 °C/modification. Molecular dynamics simulations of a DNA duplex bearing the fdG adduct revealed that though the overall B-DNA structure is maintained, this lesion can disrupt W-C H-bonding, stacking interactions, and minor groove hydrations to some extent at the modified site, and these effects lead to slight variations in the local base pair parameters. Overall, our studies show that fdG is tolerated at the minor groove of the DNA to a better extent compared with other bulky DNA damages, and this property will make it difficult for the DNA repair pathways to detect this adduct. PMID:26650891
16. GSTM1 and XRCC3 Polymorphisms: Effects on Levels of Aflatoxin B1-DNA Adducts
Institute of Scientific and Technical Information of China (English)
Xi-dai Long; Yun Ma; Zhou-lin Deng
2009-01-01
Objective: Aflatoxin B1 (AFB1), which can cause the formation of AFB1-DNA adducts, is a known human carcinogen. AFB1-exposure individuals with inherited susceptible carcinogen-metabolizing or repairing genotypes may experience an increased risk of genotoxicity. This study was designed to investigate whether the polymorphisms of two genes, the metabolic gene Glutathione S-transferase M1 (GSTM1) and DNA repair gene x-ray repair cross-complementing group 3 (XRCC3), can affect the levels of AFB1-DNA adducts in Guangxi Population (n= 966) from an AFB1-exposure area.Methods: AFB1-DNA adducts were measured by ELISA, and GSTM1 and XRCC3 codon 241 genotypes were identified by PCR-RFLP.Results: The GSTM1-null genotype [adjusted odds ratio (OR) = 2.09; 95% confidence interval (CI) = 1.61(2.71] and XRCC3 genotypes with 241 Met alleles [i.e., XRCC3-TM and -MM, adjusted ORs (95% CI) were 1.43 (1.08(1.89) and 2.42 (1.13(5.22), respectively] were significantly associated with higher levels of AFB1-DNA adducts. Compared with those individuals who did not express any putative risk genotypes as reference (OR = 1), individuals featuring all of the putative risk genotypes did experience a significantly higher DNA-adduct levels (adjusted ORs were 2.87 for GSTM1-null and XRCC3-TM; 5.83 for GSTM1-null and XRCC3-MM). Additionally, there was a positive joint effect between XRCC3 genotypes and long-term AFB1 exposure in the formation of AFB1-DNA adducts.Conclusion: These results suggest that individuals with susceptible genotypes GSTM1-null, XRCC3-TM, or XRCC3-MM may experience an increased risk of DNA damage elicited by AFB1 exposure.
17. Cisplatin-DNA adduct formation in rat spermatozoa and its effect on fetal development
NARCIS (Netherlands)
Hooser, S.T.; Dijk-Knijnenburg, C.M. van; Waalkens-Berendsen, I.D.H.; Smits-van Prooije, A.E.; Snoeij, N.J.; Baan, R.A.; Fichtinger-Schepman, M.J.
2000-01-01
Exposure of males to some genotoxic chemicals causes DNA damage in spermatozoa resulting in embryotoxicity and developmental defects in their offspring. This study demonstrates that cisplatin-DNA adducts could be measured in spermatozoa following treatment with the antineoplastic drug, cisplatin. Th
18. Formation of 1,4-dioxo-2-butene-derived adducts of 2'-deoxyadenosine and 2'-deoxycytidine in oxidized DNA.
Science.gov (United States)
Chen, Bingzi; Vu, Choua C; Byrns, Michael C; Dedon, Peter C; Peterson, Lisa A
2006-08-01
19. Estimating the DNA strand breakage using a fuzzy inference system and agarose gel electrophoresis, a case study with toothed carp Aphanius sophiae exposed to cypermethrin.
Science.gov (United States)
2016-07-01
The DNA breakage has been widely used in ecotoxicological studies to investigate effects of pesticides in fishes. The present study used a fuzzy inference system to quantify the breakage of DNA double strand in Aphanius sophiae exposed to the cypermethrin. The specimens were adapted to different temperatures and salinity for 14 days and then exposed to cypermethrin. DNA of each specimens were extracted, electrophoresed and photographed. A fuzzy system with three input variables and 27 rules were defined. The pixel value curve of DNA on each gel lane was obtained using ImageJ. The DNA breakage was quantified using the pixel value curve and fuzzy system. The defuzzified values were analyzed using a three-way analysis of variance. Cypermethrin had significant effects on DNA breakage. Fuzzy inference systems can be used as a tool to quantify the breakage of double strand DNA. DNA double strand of the gill of A. sophiae is sensitive enough to be used to detect cypermethrin in surface waters in concentrations much lower than those reported in previous studies. PMID:27000282
Science.gov (United States)
Stornetta, Alessia; Villalta, Peter W; Hecht, Stephen S; Sturla, Shana J; Balbo, Silvia
2015-12-01
1. Resveratrol mobilizes endogenous copper in human peripheral lymphocytes leading to oxidative DNA breakage: a putative mechanism for chemoprevention of cancer.
Science.gov (United States)
Hadi, S M; Ullah, M F; Azmi, A S; Ahmad, A; Shamim, U; Zubair, H; Khan, H Y
2010-06-01
Plant polyphenols are important components of human diet, and a number of them are considered to possess chemopreventive and therapeutic properties against cancer. They are recognized as naturally occurring anti-oxidants but also act as pro-oxidants catalyzing DNA degradation in the presence of metal ions such as copper. The plant polyphenol resveratrol confers resistance to plants against fungal agents and has been implicated as a cancer chemopreventive agent. Of particular interest is the observation that resveratrol has been found to induce apoptosis in cancer cell lines but not in normal cells. Over the last few years, we have shown that resveratrol is capable of causing DNA breakage in cells such as human lymphocytes. Such cellular DNA breakage is inhibited by copper specific chelators but not by iron and zinc chelating agents. Similar results are obtained by using permeabilized cells or with isolated nuclei, indicating that chromatin-bound copper is mobilized in this reaction. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and resveratrol to generate reactive oxygen species responsible for DNA cleavage. The results are in support of our hypothesis that anti-cancer mechanism of plant polyphenols involves mobilization of endogenous copper and the consequent pro-oxidant action. Such a mechanism better explains the anti-cancer effects of resveratrol, as it accounts for the preferential cytotoxicity towards cancer cells.
2. Mobilization of Copper ions by Flavonoids in Human Peripheral Lymphocytes Leads to Oxidative DNA Breakage: A Structure Activity Study
Directory of Open Access Journals (Sweden)
Hussain Arif
2015-11-01
Full Text Available Epidemiological studies have linked dietary consumption of plant polyphenols with lower incidence of various cancers. In particular, flavonoids (present in onion, tomato and other plant sources induce apoptosis and cytotoxicity in cancer cells. These can therefore be used as lead compounds for the synthesis of novel anticancer drugs with greater bioavailability. In the present study, we examined the chemical basis of cytotoxicity of flavonoids by studying the structure–activity relationship of myricetin (MN, fisetin (FN, quercetin (QN, kaempferol (KL and galangin (GN. Using single cell alkaline gel electrophoresis (comet assay, we established the relative efficiency of cellular DNA breakage as MN > FN > QN > KL > GN. Also, we determined that the cellular DNA breakage was the result of mobilization of chromatin-bound copper ions and the generation of reactive oxygen species. The relative DNA binding affinity order was further confirmed using molecular docking and thermodynamic studies through the interaction of flavonoids with calf thymus DNA. Our results suggest that novel anti-cancer molecules should have ortho-dihydroxy groups in B-ring and hydroxyl groups at positions 3 and 5 in the A-ring system. Additional hydroxyl groups at other positions further enhance the cellular cytotoxicity of the flavonoids.
3. Safrole-DNA adduct in hepatocellular carcinoma associated with betel quid chewing.
Science.gov (United States)
Chung, Yu-Ting; Chen, Chiu-Lan; Wu, Cheng-Chung; Chan, Shan-An; Chi, Chin-Wen; Liu, Tsung-Yun
2008-12-15
Betel quid chewing, which contributes high concentration of safrole in saliva, is a popular oral habit in Taiwan. Safrole is a documented rodent hepatocarcinogen, yet its hepatocarcinogenic potential in human is not known. Here, we used LC/ESI-ITMS(n) and LC/QTOF-MS confirmed safrole-dGMP as reference standard to detect the safrole-DNA adduct in hepatic tissues from HBsAg-/HCV-seronegative hepatocellular carcinoma patients by (32)P-postlabeling. We first synthesized and confirmed safrole-dGMP by LC/MS. Two isomeric safrole-dGMPs were characterized as N(2)-(trans-isosafrol-3'-yl) deoxyguanosine and N(2)-(safrol-1'-yl) deoxyguanosine. This technique was able to detect hepatic safrole-DNA adduct in mice that were treated with safrole but not sensitive enough to detect safrole-DNA adduct in human samples. Using the nuclease P1 version of the (32)P-postlabeling technique, we detected the presence of safrole-DNA adduct in two out of 28 hepatic tissues from hepatocellular carcinoma patients, and only these two patients had a history of betel quid chewing lasting more than 10 years. From co-chromatography with the mass confirmed safrole-dGMPs, this safrole-DNA adduct was identified as N(2)-(trans-isosafrol-3'-yl) deoxyguanosine. These results suggest that betel quid-containing safrole might be involved in the pathogenesis of hepatocellular carcinoma in human beings and LC/MS has the potential to identify DNA adducts in clinical samples.
4. Replication Stress-Induced Chromosome Breakage Is Correlated with Replication Fork Progression and Is Preceded by Single-Stranded DNA Formation
OpenAIRE
Feng, Wenyi; Di Rienzi, Sara C.; Raghuraman, M. K.; Brewer, Bonita J.
2011-01-01
Chromosome breakage as a result of replication stress has been hypothesized to be the direct consequence of defective replication fork progression, or “collapsed” replication forks. However, direct and genome-wide evidence that collapsed replication forks give rise to chromosome breakage is still lacking. Previously we showed that a yeast replication checkpoint mutant mec1-1, after transient exposure to replication impediment imposed by hydroxyurea (HU), failed to complete DNA replication, ac...
5. Polycyclic Aromatic Hydrocarbon–DNA Adducts and Breast Cancer: A Pooled Analysis
OpenAIRE
Gammon, Marilie D.; Sagiv, Sharon K.; Eng, Sybil M.; Shantakumar, Sumitra; Gaudet, Mia M.; Teitelbaum, Susan L; Britton, Julie A.; Terry, Mary Beth; WANG, LIAN WEN; Wang, Qiao; STELLMAN, STEVE D.; Beyea, Jan; Hatch, Maureen; Kabat, Geoffrey C; Wolff, Mary S.
2004-01-01
Polycyclic aromatic hydrocarbon (PAH)-DNA adducts have been associated with breast cancer in several small studies. The authors’ pooled analysis included 873 cases and 941 controls from a population-based case-control study. Competitive enzyme-linked immunosorbent assay in peripheral mononuclear cells was conducted in 2 rounds, and results were pooled on the basis of round-specific quantiles. The odds ratio for breast cancer was elevated in relation to detectable PAH-DNA adducts (1.29 as comp...
6. Base-Displaced Intercalated Structure of the N-(2'-Deoxyguanosin-8-yl)-3-aminobenzanthrone DNA Adduct.
Science.gov (United States)
Politica, Dustin A; Malik, Chanchal K; Basu, Ashis K; Stone, Michael P
2015-12-21
7. Inhibition of nicotine-DNA adduct formation by polyphenolic compounds in vitro
Institute of Scientific and Technical Information of China (English)
CHENG Yan; WANG Hai-Fang; SUN Hong-Fang; LI Hong-Li
2004-01-01
Nicotine [3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Some polyphenolic compounds can suppress the DNA adduction, and hence act as the potential inhibitors of carcinogenesis. In this study, the inhibitory effects of three polyphenolic compounds, curcumin (diferuloylmethane), resveratrol (trans-3, 5, 4-trihydroxystilbene) and tea polyphenols, on the nicotine-DNA adduction have been investigated in vitro using radiolabelled nicotine and liquid scintillation counting (LSC) technique. Also, the inhibition mechanism of these chemopreventive agents in regard to the activity of the biotransformation enzymes, including cytochrome P450 (CYP450), cytochrome b5 (CYb5) and glutathione S-transferase (GST), has been studied. The results demonstrated that these three polyphenols induced marked dose-dependent decrease in nicotine-DNA adducts as compared with the controls. The elimination rate of adducts reached above 46% at the highest dose for all the three agents with 51.6% for resveratrol. Correspondingly, three polyphenols all suppressed CYP450 and CYb5, whereas curcumin and resveratrol induced GST. We may arrive at a point that the three polyphenols are beneficial to prevent the nicotine adduct formation, and thus may be used to block the potential carcinogenesis induced by nicotine.
8. White blood cell DNA adducts and fruit and vegetable consumption in bladder cancer.
Science.gov (United States)
Peluso, M; Airoldi, L; Magagnotti, C; Fiorini, L; Munnia, A; Hautefeuille, A; Malaveille, C; Vineis, P
2000-02-01
9. Cigarette Smoking, BPDE-DNA Adducts, and Aberrant Promoter Methylations of Tumor Suppressor Genes (TSGs) in NSCLC from Chinese Population.
Science.gov (United States)
Jin, Yongtang; Xu, Peiwei; Liu, Xinneng; Zhang, Chunye; Tan, Cong; Chen, Chunmei; Sun, Xiaoyu; Xu, Yingchun
2016-01-01
Non-small cell lung cancer (NSCLC) is related to the genetic and epigenetic factors. The goal of this study was to determine association of cigarette smoking and BPDE-DNA adducts with promoter methylations of several genes in NSCLC. Methylation of the promoters of p16, RARβ, DAPK, MGMT, and TIMP-3 genes of tumor tissues from 199 lung cancer patients was analyzed with methylation-specific PCR (MSP), and BPDE-DNA adduct level in lung cancer tissue was obtained by ELISA. Level of BPDE-DNA adduct increased significantly in males, aged people (over 60 years), and smokers; however, no significant difference was found while comparing the BPDE-DNA adduct levels among different tumor types, locations, and stages. Cigarette smoking was also associated with increased BPDE-DNA adducts level (OR = 2.43, p > .05) and increased methylation level in at least 1 gene (OR = 5.22, p smoking also significantly increase the risk of p16 or DAPK methylation (OR = 3.02, p smoking for more than 40 pack-years (OR = 4.21, p smoking is significantly associated with the increase of BPDE-DNA adduct level, promoter hypermethylation of p16 and DAPK genes, while BPDE-DNA adduct was not significantly related to abnormal promoter hypermethylation in TSGs, suggesting that BPDE-DNA adducts and TSGs methylations play independent roles in NSCLC.
10. Glutathionetransferase activity and PAN-DNA adducts in human placenta as a risk factor for newborn in radioactively contaminated regions
International Nuclear Information System (INIS)
It was shown that the higher is the contamination of area the more decreased is GST activity and the more abundant are PAH adducts in placental DNA. Placental glutathionetransferase activity and level of PAH-DNA adducts content in placental tissue are the integral indices of environmental pollution, efficiency of maternal and placental detoxification and a prognostic factor for newborn
11. 44. Study the level of DNA breakage in workers exposed to styrene by single cell gel electrophoresis
Institute of Scientific and Technical Information of China (English)
2001-01-01
Objective: Study the level of DNA breakage in workers exposed to styrene. Methods: 35 workers aging from 18 to 40 exposed to styrene half a year above were observed as exposed group, in the mean time, 57 workers in the same district who hadn't been exposed to known genotoxicant were selected as control. Bloods of them were sampled and DNA lesions were detected by single cell gel electrophoresis. Results: Compared with control, the ratio between the length of Comet tail and the total length of Comet in exposed group significantly increased, especially it raised following the styrene concentration exposed, but it was not different among different working age groups. Conclusions: DNA is damaged by styrene, and it appears as dose-response relationship.
12. DNA strand breakage by 125I-decay in a synthetic oligodeoxynucleotide. Fragment distribution and evaluation of DMSO protection effect
International Nuclear Information System (INIS)
A double stranded oligodeoxynucleotide containing a single 125I-dC in a defined location was used to investigate DNA strand breakage resulting from 125I decay. Samples of a 41 bp oligodeoxynucleotide were incubated in 20 mM phosphate buffer (PB), or PB plus 2 M dimethylsulphoxide (DMSO), at 4 C during 18-20 days. The 32P-5'-end labelled DNA fragments produced by 125I decays were separated on denaturing polyacrylamide gels, and the 32P activity in each fragment was determined by scintillation counting after elution of fragments from gel. Most of the breaks, around 90%, occurred within 4-5 nucleotides of the 125I-dC, but DNA breaks were detected up to 16 nucleotides from the decay site. The 125I-dC was located at the 21st nucleotide from the 32P-5'-end label, and since 32P was not detected in fragments longer than 20 nucleotides, it was assumed that all 125I decay events produce at least one break in the 125I-labelled DNA strand. The results show a considerable protection effect of DMSO on DNA breaks at sites >5-6 nucleotides from the 125I location. The probability of breaks in this region was decreased with DMSO by a factor of 2 to 8-fold, suggesting significant role for radical-mediated DNA breaks at the more distant sites. However, the total protection effect of DMSO is rather small: 1.1, because of the small contribution of breakage at distant sites to the total yield. (orig.)
13. Simultaneous detection of multiple DNA adducts in human lung samples by isotope-dilution UPLC-MS/MS.
Science.gov (United States)
Monien, Bernhard H; Schumacher, Fabian; Herrmann, Kristin; Glatt, Hansruedi; Turesky, Robert J; Chesné, Christophe
2015-01-01
14. PARP1 impact on DNA repair of platinum adducts: preclinical and clinical read-outs.
Science.gov (United States)
Olaussen, Ken A; Adam, Julien; Vanhecke, Elsa; Vielh, Philippe; Pirker, Robert; Friboulet, Luc; Popper, Helmut; Robin, Angélique; Commo, Fréderic; Thomale, Jürgen; Kayitalire, Louis; Filipits, Martin; Le Chevalier, Thierry; André, Fabrice; Brambilla, Elisabeth; Soria, Jean-Charles
2013-05-01
15. Role of CYP1B1 in PAH-DNA adduct formation and breast cancer risk
Energy Technology Data Exchange (ETDEWEB)
Goth-Goldstein, Regine; Russell, Marion L.; Muller, A.P.; Caleffi, M.; Eschiletti, J.; Graudenz, M.; Sohn, Michael D.
2010-04-01
This study investigated the hypothesis that increased exposure to polycyclic aromatic hydrocarbons (PAHs) increases breast cancer risk. PAHs are products of incomplete burning of organic matter and are present in cigarette smoke, ambient air, drinking water, and diet. PAHs require metabolic transformation to bind to DNA, causing DNA adducts, which can lead to mutations and are thought to be an important pre-cancer marker. In breast tissue, PAHs appear to be metabolized to their cancer-causing form primarily by the cytochrome P450 enzyme CYP1B1. Because the genotoxic impact of PAH depends on their metabolism, we hypothesized that high CYP1B1 enzyme levels result in increased formation of PAH-DNA adducts in breast tissue, leading to increased development of breast cancer. We have investigated molecular mechanisms of the relationship between PAH exposure, CYP1B1 expression and breast cancer risk in a clinic-based case-control study. We collected histologically normal breast tissue from 56 women (43 cases and 13 controls) undergoing breast surgery and analyzed these specimens for CYP1B1 genotype, PAH-DNA adducts and CYP1B1 gene expression. We did not detect any difference in aromatic DNA adduct levels of cases and controls, only between smokers and non-smokers. CYP1B1 transcript levels were slightly lower in controls than cases, but the difference was not statistically significant. We found no correlation between the levels of CYP1B1 expression and DNA adducts. If CYP1B1 has any role in breast cancer etiology it might be through its metabolism of estrogen rather than its metabolism of PAHs. However, due to the lack of statistical power these results should be interpreted with caution.
16. Dosimetry by means of DNA and hemoglobin adducts in propylene oxide-exposed rats
International Nuclear Information System (INIS)
The main purpose of the study was to establish the relation between exposure dose of propylene oxide (PO) and dose in various tissues of male F344 rats exposed to the compound by inhalation. The animals were exposed to 0, 5, 25, 50, 300, or 500 ppm PO in the air for 3 days (6 h/day) or 4 weeks (6 h/day, 5 days/week). Blood, nasal respiratory epithelium, lung, and liver were collected. 2-Hydroxypropylvaline (HPVal) in hemoglobin was quantified using the N-alkyl Edman method and gas chromatography/tandem mass spectrometry. 7-(2-Hydroxypropyl)guanine (7-HPG) in DNA was quantified using 32P postlabeling. The levels of 7-HPG in DNA of nasal respiratory epithelium and lung increased linearly with concentration as measured both after 3 days and 4 weeks of exposure. Similarly, 7-HPG in liver DNA and HPVal in hemoglobin showed a linear increase with PO concentration in the 3-day exposure group, whereas a deviation from linearity was observed above 300 ppm in the 4-week exposure group. The new results confirm previous observations of a dose difference between tissues with the highest dose present in the nasal respiratory epithelium. The measured adduct levels were used for calculation of adduct increments and corresponding tissue doses per unit of external exposure dose. For this purpose, the buildup of adducts was modeled considering the different kinetics of formation and elimination of adducts with DNA and hemoglobin, respectively, and also considering the increasing body weight of the animals. The half-life of 7-HPG in vivo, as well as tissue doses, could be solved from DNA adduct data at the 3rd and 26th days. Within the range of concentrations where the dose-response curves for adduct formation are linear, the relationship between exposure dose and resulting tissue doses could be based equally well on adduct data from the short-term exposure as on adduct data from the prolonged exposure
17. DNA adducts induced by in vitro activation of extracts of diesel and biodiesel exhaust particles
Science.gov (United States)
AbstractContext: Biodiesel and biodiesel-blend fuels offer a renewable alternative to petroleum diesel, but few data are available concerning the carcinogenic potential of biodiesel exhausts. Objectives: We compared the formation of covalent DNA adducts by the in vitro metabol...
18. Role of Fanconi Anemia FANCG in Preventing Double-Strand Breakage and Chromosomal Rearrangement during DNA Replication
Energy Technology Data Exchange (ETDEWEB)
Tebbs, R S; Hinz, J M; Yamada, N A; Wilson, J B; Jones, N J; Salazar, E P; Thomas, C B; Jones, I M; Thompson, L H
2003-10-04
The Fanconi anemia (FA) proteins overlap with those of homologous recombination through FANCD1/BRCA2, but the biochemical functions of other FA proteins are unknown. By constructing and characterizing a null fancg mutant of hamster CHO cells, we present several new insights for FA. The fancg cells show a broad sensitivity to genotoxic agents, not supporting the conventional concept of sensitivity to only DNA crosslinking agents. The aprt mutation rate is normal, but hprt mutations are reduced, which we ascribe to the lethality of large deletions. CAD and dhfr gene amplification rates are increased, implying excess chromosomal breakage during DNA replication, and suggesting amplification as a contributing factor to cancer-proneness in FA patients. In S-phase cells, both spontaneous and mutagen-induced Rad51 nuclear foci are elevated. These results support a model in which FancG protein helps to prevent collapse of replication forks by allowing translesion synthesis or lesion bypass through homologous recombination.
19. Calcitriol-copper interaction leads to non enzymatic, reactive oxygen species mediated DNA breakage and modulation of cellular redox scavengers in hepatocellular carcinoma.
Science.gov (United States)
Rizvi, Asim; Farhan, Mohd; Naseem, Imrana; Hadi, S M
2016-09-01
Calcitriol is the metabolically active form of Vitamin D and is known to kill cancer cells. Using the rat model of DEN induced hepatocellular carcinoma we show that there is a marked increase in cellular levels of copper in hepatocellular carcinoma and that calcitriol-copper interaction leads to reactive oxygen species mediated DNA breakage selectively in hepatocellular carcinoma cells. In vivo studies show that calcitriol selectively induces severe fluctuations in cellular enzymatic and non enzymatic scavengers of reactive oxygen species in the malignant tissue. Lipid peroxidation, a well established marker of oxidative stress, was found to increase, and substantial cellular DNA breakage was observed. We propose that calcitriol is a proxidant in the cellular milieu of hepatocellular carcinoma cells, and this copper mediated prooxidant action of calcitriol causes selective DNA breakage in malignant cells, while sparing normal (non malignant) cells. PMID:27343126
20. Detection of benzo[a]pyrene diol epoxide-DNA adducts in peripheral blood lymphocytes and antibodies to the adducts in serum from coke oven workers.
OpenAIRE
Harris, C. C.; Vahakangas, K.; Newman, M J; Trivers, G E; Shamsuddin, A; Sinopoli, N; Mann, D L; Wright, W. E.
1985-01-01
Coke oven workers are exposed to high levels of carcinogenic polycyclic aromatic hydrocarbons, including benzo[a]pyrene (B[a]P), and are at increased risk of lung cancer. Since B[a]P is enzymatically activated to 7 beta,8 alpha-dihydroxy(9 alpha, 10 alpha)epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (B[a]PDE) that forms adducts with DNA, the presence of these adducts was measured in DNA from peripheral blood lymphocytes by synchronous fluorescence spectrophotometry and enzyme radioimmunoassay. App...
1. Benzo(a)pyrene diolepoxide-DNA adducts detected by synchronous fluorescence spectrophotometry.
OpenAIRE
Vahakangas, K.; Trivers, G; Rowe, M.; Harris, C. C.
1985-01-01
Using benzo(a)pyrene (BP) as a model carcinogen we are currently applying a fluorescence technique to detect the very low levels of carcinogen-DNA adducts in human populations due to environmental exposure. In synchronous fluorescence spectrophotometry for detection of BP-diol epoxide-DNA, excitation and emission wavelengths are scanned simultaneously with a fixed wavelength difference (delta lambda) of 34 nm. Compared to conventional fluorescence methods only one peak emerges because excitat...
2. Differential repair of platinum-DNA adducts in human bladder and testicular tumor continuous cell lines
International Nuclear Information System (INIS)
The formation and removal of four platinum-DNA adducts were immunochemically quantitated in cultured cells derived from a human bladder carcinoma cell line (RT112) and from two lines derived from germ cell tumors of the testis (833K and SUSA), following exposure in vitro to 16.7 microM (5 micrograms/ml) cisplatin. RT112 cells were least sensitive to the drug and were proficient in the repair of all four adducts, whereas SUSA cells, which were 5-fold more sensitive, were deficient in the repair of DNA-DNA intrastrand cross-links in the sequences pApG and pGpG. Despite expressing a similar sensitivity to SUSA cells, 833K cells were proficient in the repair of all four adducts, although less so than the RT112 bladder tumor cells. In addition, SUSA cells were unable to repair DNA-DNA interstrand cross-links whereas 50-85% of these lesions were removed in RT112 and 833K cells 24 h following drug exposure. It is possible that the inability of SuSa cells to repair platinated DNA may account for their hypersensitivity to cisplatin
3. Targeted mutations induced by a single acetylaminofluorene DNA adduct in mammalian cells and bacteria
International Nuclear Information System (INIS)
Mutagenic specificity of 2-acetylaminofluorene (AAF) has been established in mammalian cells and several strains of bacteria by using a shuttle plasmid vector containing a single N-(deoxyguanosin-8-yl)acetylaminofluorene (C8-dG-AAF) adduct. The nucleotide sequence of the gene conferring tetracycline resistance was modified by conservative codon replacement so as to accommodate the sequence d(CCTTCGCTAC) flanked by two restriction sites, Bsm I and Xho I. The corresponding synthetic oligodeoxynucleotide underwent reaction with 2-(N-acetoxy-N-acetylamino)-fluorene (AAAF), forming a single dG-AAF adduct. This modified oligodeoxynucleotide was hybridized to its complementary strand and ligated between the Bsm I and Xho I sites of the vector. Plasmids containing the C8-dG-AAF adduct were used to transfect simian virus 40-transformed simian kidney (COS-1) cells and to transform several AB strains of Escherichia coli. Colonies containing mutant plasmides were detected by hybridization to 32P-labeled oligodeoxynucleotides. Presence of the single DNA adduct increased the mutation frequency by 8-fold in both COS cells and E. coli. Over 80% of mutations detected in both systems were targeted and represented G x C → C x G or G x C → T x A transversions or single nucleotide deletions. The authors conclude that modification of a deoxyguanosine residue with AAF preferentially induces mutations targeted at this site when a plasmid containing a single C8-dG-AAF adduct is introduced into mammalian cells or bacteria
4. 32P-postlabelling analysis of dibenz[a,j]acridine-DNA adducts in mice: identification of proximate metabolites.
Science.gov (United States)
Talaska, G; Roh, J; Schamer, M; Reilman, R; Xue, W; Warshawsky, D
1995-03-30
5. AlkB recognition of a bulky DNA base adduct stabilized by chemical cross-linking
Institute of Scientific and Technical Information of China (English)
2010-01-01
E.coli AlkB is a direct DNA/RNA repair protein that oxidatively reverses N1 alkylated purines and N3 alkylated pyrimidines to regular bases.Previous crystal structures have revealed N1-methyl adenine(1-meA) recognition by AlkB and a unique base flipping mechanism,but how the AlkB active site can accommodate bulky base adducts is largely unknown.Employing a previously developed chemical cross-linking technique,we crystallized AlkB with a duplex DNA containing a caged thymine base(cagedT).The structure revealed a flexible hairpin lid and a reorganized substrate recognition loop used by AlkB to accommodate cagedT.These observations demonstrate,at the molecular level,how bulky DNA adducts may be recognized and processed by AlkB.
6. Quantitative comparison between in vivo DNA adduct formation from exposure to selected DNA-reactive carcinogens, natural background levels of DNA adduct formation and tumour incidende in rodent bioassays
NARCIS (Netherlands)
Paini, A.; Scholz, G.; Marin-Kuan, M.; Schilter, B.; O'Brien, J.; Bladeren, van P.J.; Rietjens, I.
2011-01-01
This study aimed at quantitatively comparing the occurrence/formation of DNA adducts with the carcinogenicity induced by a selection of DNA-reactive genotoxic carcinogens. Contrary to previous efforts, we used a very uniform set of data, limited to in vivo rat liver studies in order to investigate w
7. Few constraints limit the design of quinone methide-oligonucleotide self-adducts for directing DNA alkylation†
OpenAIRE
Rossiter, Clifford S.; Modica, Emilia; Kumar, Dalip; Rokita, Steven E
2010-01-01
Nucleotide sequences minimally containing adenosine, cytosine or guanosine are sufficient to form intrastrand oligonucleotide quinone methide self-adducts reversibly for subsequent alkylation of complementary DNA. The general lack of sequence restrictions should now allow for alkylation of most any target of interest although reaction is most efficient when the self-adducts contain guanine residues and do not form hairpin structures.
8. Lifestyle, Environmental, and Genetic Predictors of Bulky DNA Adducts in a Study Population Nested within a Prospective Danish Cohort
DEFF Research Database (Denmark)
Eriksen, K. T.; Sørensen, M.; Autrup, H.;
2010-01-01
Danish cohort. At enrollment, blood samples were collected and information on lifestyle, including dietary and smoking habits, obtained. Previously, bulky DNA adducts were measured in 245 individuals who developed lung cancer and 255 control members of the cohort. Of these 500 individuals, data on 375...... found between dietary factors or smoking and DNA adduct levels. Further, the results showed no prominent associations between any of 12 genetic polymorphisms and adduct levels. Overall, our study showed only few associations between dietary, environmental, and genetic factors and levels of bulky DNA...
9. Use of the /sup 32/P-postlabeling method to detect DNA adducts of 2-amino-3-methylimidazolo(4,5-f)quinoline (IQ) in monkeys fed IQ: identification of the N-(deoxyguanosin-8-yl)-IQ adduct
Energy Technology Data Exchange (ETDEWEB)
Snyderwine, E.G.; Yamashita, K.; Adamson, R.H.; Sato, S.; Nagao, M.; Sugimura, T.; Thorgeirsson, S.S.
1988-10-01
10. Calculation of DNA strand breakage by neutralisation effect after 125I decays in a synthetic oligodeoxynucleotide using charge transfer theory
International Nuclear Information System (INIS)
The decay of the radioisotope 125I into 125Te is typically followed by the emission of two groups of approximately 10 electrons each via Auger processes. In deoxyribonucleic acid (DNA) with 125I incorporated, these electrons produce various types of damage to DNA, e.g. single strand breaks (SSBs) and double strand breaks (DSBs) through direct actions of physical tracks, or indirect actions of radicals produced in water. Among the direct actions one should consider not only the excitation and ionisation of DNA by Auger electrons, but also the neutralisation of highly charged 125mTe ions with electrons from neighbouring molecules. Comparison between experiment and simulation done recently revealed that without including neutralisation effect the simulated yield of SSBs was 50% less than the measured result. In the present work a calculation of DNA strand breakage by the neutralization effect in a 41-mer synthetic oligodeoxynucleotide (oligo-DNA) model was done using the charge transfer theory. Calculation based on transfer rate using the newly evaluated electronic coupling of DNA bases showed that the positive charge (hole) transfer rate is of the order of magnitudes of several 1013s-1, implying that a charge higher than 10 units might not build on a 125mTe atom. The potential energy accumulated on the decay base is transferred to bases along the DNA chain nearby and destroys those bases and ionises the sugar-phosphate group, leading a DNA SSB with a frequency of 0.2% per eV in average. (authors)
11. Bypass of Aflatoxin B[subscript 1] Adducts by the Sulfolobus solfataricus DNA Polymerase IV
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Surajit; Brown, Kyle L.; Egli, Martin; Stone, Michael P. (Vanderbilt)
2012-07-18
Aflatoxin B{sub 1} (AFB{sub 1}) is oxidized to an epoxide in vivo, which forms an N7-dG DNA adduct (AFB{sub 1}-N7-dG). The AFB{sub 1}-N7-dG can rearrange to a formamidopyrimidine (AFB{sub 1}-FAPY) derivative. Both AFB{sub 1}-N7-dG and the {beta}-anomer of the AFB{sub 1}-FAPY adduct yield G {yields} T transversions in Escherichia coli, but the latter is more mutagenic. We show that the Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) bypasses AFB{sub 1}-N7-dG in an error-free manner but conducts error-prone replication past the AFB{sub 1}-FAPY adduct, including misinsertion of dATP, consistent with the G {yields} T mutations observed in E. coli. Three ternary (Dpo4-DNA-dNTP) structures with AFB{sub 1}-N7-dG adducted template:primers have been solved. These demonstrate insertion of dCTP opposite the AFB{sub 1}-N7-dG adduct, and correct vs incorrect insertion of dATP vs dTTP opposite the 5'-template neighbor dT from a primed AFB{sub 1}-N7-dG:dC pair. The insertion of dTTP reveals hydrogen bonding between the template N3 imino proton and the O{sup 2} oxygen of dTTP, and between the template T O{sup 4} oxygen and the N3 imino proton of dTTP, perhaps explaining why this polymerase does not efficiently catalyze phosphodiester bond formation from this mispair. The AFB{sub 1}-N7-dG maintains the 5'-intercalation of the AFB{sub 1} moiety observed in DNA. The bond between N7-dG and C8 of the AFB{sub 1} moiety remains in plane with the alkylated guanine, creating a 16{sup o} inclination of the AFB{sub 1} moiety with respect to the guanine. A binary (Dpo4-DNA) structure with an AFB{sub 1}-FAPY adducted template:primer also maintains 5'-intercalation of the AFB{sub 1} moiety. The {beta}-deoxyribose anomer is observed. Rotation about the FAPY C5-N{sup 5} bond orients the bond between N{sup 5} and C8 of the AFB{sub 1} moiety out of plane in the 5'-direction, with respect to the FAPY base. The formamide group extends in the 3'-direction. This improves
12. Lipid peroxidation-derived etheno-DNA adducts in human atherosclerotic lesions
Energy Technology Data Exchange (ETDEWEB)
Nair, Jagadeesan [Division of Toxicology and Cancer Risk Factors, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany); De Flora, Silvio [Department of Health Sciences, University of Genoa, Via A. Pastore 1, I-16132 Genoa (Italy); Izzotti, Alberto [Department of Health Sciences, University of Genoa, Via A. Pastore 1, I-16132 Genoa (Italy); Bartsch, Helmut [Division of Toxicology and Cancer Risk Factors, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg (Germany)]. E-mail: h.bartsch@dkfz.de
2007-08-01
Atherosclerosis and cancer are characterized by uncontrolled cell proliferation and share common risk factors, such as cigarette smoking, dietary habits and ageing. Growth of smooth muscle cells (SMCs) in atherosclerotic plaques may result from DNA damage, caused either by exogenous mutagens or by agents endogenously generated due to oxidative stress and lipid peroxidation (LPO). Hydroxy-2-nonenal (HNE), a major LPO product, binds covalently to cellular DNA to form the exocyclic etheno-DNA-base adducts, 1,N {sup 6}-ethenodeoxyadenine ({epsilon}dA) and 3,N {sup 4}-ethenodeoxycytosine ({epsilon}dC). By applying an ultrasensitive {sup 32}P-postlabeling-immunoaffinity method, {epsilon}dA and {epsilon}dC were quantified in abdominal aorta SMCs from 13 atherosclerotic patients and 3 non-smoking subjects without atherosclerotic lesions. The levels of etheno-adducts ranged for {epsilon}dA from 2.3 to 39.6/10{sup 8} dA and for {epsilon}dC from 10.7 to 157.7/10{sup 8} dC, with a high correlation between {epsilon}dA and {epsilon}dC (r = 0.84, P = 0.0001). Etheno-adduct levels were higher in atherosclerotic smokers than in ex-smokers for both {epsilon}dA (means 15.2 versus 7.3, P = 0.06) and {epsilon}dC (71.9 versus 51.6, not significant). {epsilon}dC levels were higher in either ex-smokers (P = 0.03) or smokers (P = 0.07) than in non-smokers. There was a poor correlation between either {epsilon}dA or {epsilon}dC and 8-hydroxy-2'-deoxyguanosine, whereas significant positive correlations were detected with the levels of several postlabeled bulky aromatic DNA adducts. In conclusion, two different types of DNA damage may be involved in atherosclerotic plaque formation and progression: (i) bulky aromatic compounds, to which aorta SMCs are chronically exposed in smokers, can either covalently bind to DNA, induce redox-cycling via quinone intermediates and/or activate local chronic inflammatory processes in the arterial wall; ii) this in turn leads to a self perpetuating
13. Mechanism of repair of 5'-topoisomerase II-DNA adducts by mammalian tyrosyl-DNA phosphodiesterase 2
Energy Technology Data Exchange (ETDEWEB)
Schellenberg, Matthew J; Appel, C Denise; Adhikari, Sanjay; Robertson, Patrick D; Ramsden, Dale A; Williams, R Scott [NIH; (Georgetown); (UNC)
2012-10-28
The topoisomerase II (topo II) DNA incision-and-ligation cycle can be poisoned (for example following treatment with cancer chemotherapeutics) to generate cytotoxic DNA double-strand breaks (DSBs) with topo II covalently conjugated to DNA. Tyrosyl-DNA phosphodiesterase 2 (Tdp2) protects genomic integrity by reversing 5'-phosphotyrosyl–linked topo II–DNA adducts. Here, X-ray structures of mouse Tdp2–DNA complexes reveal that Tdp2 β–2-helix–β DNA damage–binding 'grasp', helical 'cap' and DNA lesion–binding elements fuse to form an elongated protein-DNA conjugate substrate-interaction groove. The Tdp2 DNA-binding surface is highly tailored for engagement of 5'-adducted single-stranded DNA ends and restricts nonspecific endonucleolytic or exonucleolytic processing. Structural, mutational and functional analyses support a single–metal ion catalytic mechanism for the exonuclease-endonuclease-phosphatase (EEP) nuclease superfamily and establish a molecular framework for targeted small-molecule blockade of Tdp2-mediated resistance to anticancer topoisomerase drugs.
14. TRANSPLATIN-CONJUGATED TRIPLEX-FORMING OLIGONUCLEOTIDES FORM ADDUCTS WITH BOTH STRANDS OF DNA
OpenAIRE
Campbell, Meghan A.; Miller, Paul S.
2009-01-01
Triplex-forming oligonucleotides (TFOs) can bind to polypurine•polypyrimidine tracts in DNA and as a consequence, perturb normal functioning of a targeted gene. The effectiveness of such anti-gene TFOs can potentially be enhanced by covalent attachment of the TFO to its DNA target. Here we report that attachment of N-7-platinated guanine nucleosides to the 3′- and/or 5′-ends of oligopyrimidine TFOs enables these TFOs to form highly stable adducts with target DNA deoxyguanosines or deoxyadenos...
15. SU-E-T-241: Monte Carlo Simulation Study About the Prediction of Proton-Induced DNA Strand Breakage On the Double Helix Structure
Energy Technology Data Exchange (ETDEWEB)
Shin, J; Park, S; Jeong, J; Jeong, C [National Cancer Center, Goyang, Gyeonggi-do (Korea, Republic of); Lim, Y; Lee, S [National Cancer Center in Korea, Goyang, Gyeonggi-do (Korea, Republic of); SHIN, D [National Cancer Center, Goyangsi, Gyeonggi-do (Korea, Republic of); Incerti, S [Universite Bordeaux 1, CNRS.IN2P3, Centres d’Etudes Nucleaires de Bordeau, Gradignan, Gradignan (France)
2014-06-01
Purpose: In particle therapy and radiobiology, the investigation of mechanisms leading to the death of target cancer cells induced by ionising radiation is an active field of research. Recently, several studies based on Monte Carlo simulation codes have been initiated in order to simulate physical interactions of ionising particles at cellular scale and in DNA. Geant4-DNA is the one of them; it is an extension of the general purpose Geant4 Monte Carlo simulation toolkit for the simulation of physical interactions at sub-micrometre scale. In this study, we present Geant4-DNA Monte Carlo simulations for the prediction of DNA strand breakage using a geometrical modelling of DNA structure. Methods: For the simulation of DNA strand breakage, we developed a specific DNA geometrical structure. This structure consists of DNA components, such as the deoxynucleotide pairs, the DNA double helix, the nucleosomes and the chromatin fibre. Each component is made of water because the cross sections models currently available in Geant4-DNA for protons apply to liquid water only. Also, at the macroscopic-scale, protons were generated with various energies available for proton therapy at the National Cancer Center, obtained using validated proton beam simulations developed in previous studies. These multi-scale simulations were combined for the validation of Geant4-DNA in radiobiology. Results: In the double helix structure, the deposited energy in a strand allowed to determine direct DNA damage from physical interaction. In other words, the amount of dose and frequency of damage in microscopic geometries was related to direct radiobiological effect. Conclusion: In this report, we calculated the frequency of DNA strand breakage using Geant4- DNA physics processes for liquid water. This study is now on-going in order to develop geometries which use realistic DNA material, instead of liquid water. This will be tested as soon as cross sections for DNA material become available in Geant4
16. Determination of DNA adducts by combining acid-catalyzed hydrolysis and chromatographic analysis of the carcinogen-modified nucleobases.
Science.gov (United States)
Leung, Elvis M K; Deng, Kailin; Wong, Tin-Yan; Chan, Wan
2016-01-01
The commonly used method of analyzing carcinogen-induced DNA adducts involves the hydrolysis of carcinogen-modified DNA samples by using a mixture of enzymes, followed by (32)P-postlabeling or liquid chromatography (LC)-based analyses of carcinogen-modified mononucleotides/nucleosides. In the present study, we report the development and application of a new approach to DNA adduct analysis by combining the H(+)/heat-catalyzed release of carcinogen-modified nucleobases and the use of LC-based methods to analyze DNA adducts. Results showed that heating the carcinogen-modified DNA samples at 70 °C for an extended period of 4 to 6 h in the presence of 0.05% HCl can efficiently induce DNA depurination, releasing the intact carcinogen-modified nucleobases for LC analyses. After optimizing the hydrolysis conditions, DNA samples with C8- and N (2) -modified 2'-deoxyguanosine, as well as N (6) -modified 2'-deoxyadenosine, were synthesized by reacting DNA with 1-nitropyrene, acetaldehyde, and aristolochic acids, respectively. These samples were then hydrolyzed, and the released nucleobase adducts were analyzed using LC-based analytical methods. Analysis results demonstrated a dose-dependent release of target DNA adducts from carcinogen-modified DNA samples, indicating that the developed H(+)/heat-catalyzed hydrolysis method was quantitative. Comparative studies with enzymatic digestion method on carcinogen-modified DNA samples revealed that the two hydrolysis methods did not yield systematically different results.
17. Metabolic Activation of the Tumorigenic Pyrrolizidine Alkaloid, Retrorsine, Leading to DNA Adduct Formation In Vivo
Directory of Open Access Journals (Sweden)
Ming W. Chou
2005-04-01
Full Text Available Pyrrolizidine alkaloids are naturally occurring genotoxic chemicals produced by a large number of plants. The high toxicity of many pyrrolizidine alkaloids has caused considerable loss of free-ranging livestock due to liver and pulmonary lesions. Chronic exposure of toxic pyrrolizidine alkaloids to laboratory animals induces cancer. This investigation studies the metabolic activation of retrorsine, a representative naturally occurring tumorigenic pyrrolizidine alkaloid, and shows that a genotoxic mechanism is correlated to the tumorigenicity of retrorsine. Metabolism of retrorsine by liver microsomes of F344 female rats produced two metabolites, 6, 7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP, at a rate of 4.8 ± 0.1 nmol/mg/min, and retrorsine-N-oxide, at a rate of 17.6±0.5 nmol/mg/min. Metabolism was enhanced 1.7-fold by using liver microsomes prepared from dexamethasone-treated rats. DHP formation was inhibited 77% and retrorsine N-oxide formation was inhibited 29% by troleandomycin, a P450 3A enzyme inhibitor. Metabolism of retrorsine with lung, kidney, and spleen microsomes from dexamethasone-treated rats also generated DHP and the N-oxide derivative. When rat liver microsomal metabolism of retrorsine occurred in the presence of calf thymus DNA, a set of DHP-derived DNA adducts was formed; these adducts were detected and quantified by using a previously developed 32P-postlabeling/HPLC method. These same DNA adducts were also found in liver DNA of rats gavaged with retrorsine. Since DHP-derived DNA adducts are suggested to be potential biomarkers of riddelliine-induced tumorigenicity, our results indicate that (i similar to the metabolic activation of riddelliine, the mechanism of retrorsine-induced carcinogenicity in rats is also through a genotoxic mechanism involving DHP; and (ii the set of DHP-derived DNA adducts found in liver DNA of rats gavaged with retrorsine or riddelliine can serve as biomarkers for the
18. Adaptive Response Enzyme AlkB Preferentially Repairs 1-Methylguanine and 3-Methylthymine Adducts in Double-Stranded DNA.
Science.gov (United States)
Chen, Fangyi; Tang, Qi; Bian, Ke; Humulock, Zachary T; Yang, Xuedong; Jost, Marco; Drennan, Catherine L; Essigmann, John M; Li, Deyu
2016-04-18
The AlkB protein is a repair enzyme that uses an α-ketoglutarate/Fe(II)-dependent mechanism to repair alkyl DNA adducts. AlkB has been reported to repair highly susceptible substrates, such as 1-methyladenine and 3-methylcytosine, more efficiently in ss-DNA than in ds-DNA. Here, we tested the repair of weaker AlkB substrates 1-methylguanine and 3-methylthymine and found that AlkB prefers to repair them in ds-DNA. We also discovered that AlkB and its human homologues, ABH2 and ABH3, are able to repair the aforementioned adducts when the adduct is present in a mismatched base pair. These observations demonstrate the strong adaptability of AlkB toward repairing various adducts in different environments. PMID:26919079
19. Maternal diet and dioxin-like activity, bulky DNA adducts and micronuclei in mother-newborns
Energy Technology Data Exchange (ETDEWEB)
Pedersen, Marie, E-mail: mpedersen@creal.cat [Section of Environmental Health, Department of Public Health, University of Copenhagen, CSS, Oester Farimagsgade, Copenhagen K (Denmark); Halldorsson, Thorhallur I., E-mail: lur@ssi.dk [Faculty of Food Science and Nutrition, School of Health Sciences, University of Iceland Reykjavik (Iceland); Center for Fetal Programming, Department of Epidemiology, Statens Serum Institute, Copenhagen (Denmark); Autrup, Herman, E-mail: ha@mil.au.dk [School of Public Health, Department of Environmental and Occupational Medicine, Aarhus University, Aarhus (Denmark); Brouwer, Abraham, E-mail: Bram.Brouwer@bds.nl [BioDetection Systems B.V., Amsterdam (Netherlands); Besselink, Harrie, E-mail: Harrie.Besselink@bds.nl [BioDetection Systems B.V., Amsterdam (Netherlands); Loft, Steffen, E-mail: stl@sund.ku.dk [Section of Environmental Health, Department of Public Health, University of Copenhagen, CSS, Oester Farimagsgade, Copenhagen K (Denmark); Knudsen, Lisbeth E., E-mail: liek@sund.ku.dk [Section of Environmental Health, Department of Public Health, University of Copenhagen, CSS, Oester Farimagsgade, Copenhagen K (Denmark)
2012-06-01
Maternal diet can contribute to carcinogenic exposures and also modify effects of environmental exposures on maternal and fetal genetic stability. In this study, associations between maternal diet and the levels of dioxin-like plasma activity, bulky DNA adducts in white blood cells and micronuclei (MN) in lymphocytes from mother to newborns were examined. From 98 pregnant women living in the greater area of Copenhagen, Denmark in 2006-2007, maternal peripheral blood and umbilical cord blood were collected, together with information on health, environmental exposure and lifestyle. Maternal diet was estimated on the basis of maternal food frequency questionnaire (FFQ) completed by the end of pregnancy. Biomarkers were detected in paired blood samples through the dioxin-responsive chemical-activated luciferase expression (CALUX){sup Registered-Sign} bioassay, {sup 32}P-postlabelling technique and cytokinesis-block MN assay. Maternal preference for meats with dark surface were significantly associated with higher bulky DNA adducts in both maternal ({beta} 95%CI; 0.46 (0.08, 0.84)) and cord blood ({beta} 95%CI; 0.46 (0.05, 0.86)) before and after adjustment for potential confounders. No other significant associations between the 18 dietary variables and the biomarkers measured in maternal and fetal samples were identified. The present study suggests that maternal intake of meats with dark surface contributes to the bulky DNA adduct levels in maternal and umbilical cord blood. Relationship between food preparation and bulky DNA adducts appear to be captured by a FFQ while potential associations for other biomarkers might be more complex or need larger sample size.
20. Maternal diet and dioxin-like activity, bulky DNA adducts and micronuclei in mother–newborns
International Nuclear Information System (INIS)
Maternal diet can contribute to carcinogenic exposures and also modify effects of environmental exposures on maternal and fetal genetic stability. In this study, associations between maternal diet and the levels of dioxin-like plasma activity, bulky DNA adducts in white blood cells and micronuclei (MN) in lymphocytes from mother to newborns were examined. From 98 pregnant women living in the greater area of Copenhagen, Denmark in 2006–2007, maternal peripheral blood and umbilical cord blood were collected, together with information on health, environmental exposure and lifestyle. Maternal diet was estimated on the basis of maternal food frequency questionnaire (FFQ) completed by the end of pregnancy. Biomarkers were detected in paired blood samples through the dioxin-responsive chemical-activated luciferase expression (CALUX)® bioassay, 32P-postlabelling technique and cytokinesis-block MN assay. Maternal preference for meats with dark surface were significantly associated with higher bulky DNA adducts in both maternal (β 95%CI; 0.46 (0.08, 0.84)) and cord blood (β 95%CI; 0.46 (0.05, 0.86)) before and after adjustment for potential confounders. No other significant associations between the 18 dietary variables and the biomarkers measured in maternal and fetal samples were identified. The present study suggests that maternal intake of meats with dark surface contributes to the bulky DNA adduct levels in maternal and umbilical cord blood. Relationship between food preparation and bulky DNA adducts appear to be captured by a FFQ while potential associations for other biomarkers might be more complex or need larger sample size.
1. Phosphatase activity in commercial spleen exonuclease decreases the recovery of benzo[a]pyrene and N-hydroxy-2-naphthylamine DNA adducts by 32P-postlabeling.
Science.gov (United States)
Adams, S P; Laws, G M; Selden, J R; Nichols, W W
1994-05-15
Spleen exonuclease, which degrades nucleic acids into single 3'-nucleotides, is used in the detection of DNA adducts by 32P-postlabeling. Contamination of the exonuclease with phosphatase activity can reduce the recovery of benzo[a]pyrene and N-hydroxy-2-naphthylamine DNA adducts by 32P-postlabeling. Four preparations of spleen exonuclease containing varying levels of phosphatase activity (2-naphthylamine DNA adducts. Surprisingly, recovery of these DNA adducts was nearly 10 times greater using nuclease P1 than when using 1-butanol extraction for adduct enrichment, since arylamine DNA adducts have previously been reported to be poorly detected by 32P-postlabeling after nuclease P1 treatment. Our data indicate that the hydrolysis of DNA by spleen exonuclease may be an important source of variability in both qualitative and quantitative analysis of adducts by 32P-postlabeling. PMID:8059938
2. 32P-postlabelling analysis of DNA adducted with urinary mutagens from smokers of black tobacco.
Science.gov (United States)
Peluso, M; Castegnaro, M; Malaveille, C; Talaska, G; Vineis, P; Kadlubar, F; Bartsch, H
1990-08-01
In order to characterize the tobacco-derived mutagens excreted in the urine of tobacco smokers, 32P-postlabelling techniques were used to examine DNA adducts formed from these mutagens with calf thymus DNA in the presence of a metabolic activation system (rat liver S9, Aroclor 1254-induced, with or without acetyl coenzyme A). Using either nuclease P1 or butanol extraction procedures, four-six and three spots, respectively, were reproducibly found on the autoradiograms in the case of the urine extract from two smokers of black tobacco. Using the urinary extract from a non-smoker, only three faint spots were detected after nuclease P1 enrichment. DNA adducts produced in smokers' urine were then compared with those formed by four N-hydroxyarylamines, N-hydroxy-2-amino-3,8-dimethyl-3H-imidazo[4,5-f]quinoxaline, N-hydroxy-2-amino-3-methyl-imidazo[4,5-f]quinoxaline, N-hydroxy-2-naphthylamine and N-hydroxy-4-aminobiphenyl. Visual inspection revealed that none of the reference aromatic amines contributed to the adduct pattern produced by the urinary mutagen(s). However, primary aromatic amines are mainly implicated as urinary mutagens because: (i) they produce frameshift mutations in Salmonella typhimurium strains, (ii) they are easily extractable with blue cotton and (iii) their mutagenicity is abolished by a nitrite treatment procedure for deamination. PMID:2387016
3. Modulation of the Effect of Prenatal PAH Exposure on PAH-DNA Adducts in Cord Blood by Plasma Antioxidants
OpenAIRE
Kelvin, Elizabeth A.; Edwards, Susan; Jedrychowski, Wieslaw; Schleicher, Rosemary L.; Camann, David; Tang, Deliang; Perera, Frederica P.
2009-01-01
The fetus is more susceptible than the adult to the effects of certain carcinogens, such as polycyclic aromatic hydrocarbons (PAH). Nutritional factors, including antioxidants, have been shown to have a protective effect on carcinogen-DNA adducts and cancer risk in adults. We investigated whether the effect of prenatal airborne PAH exposure, measured by personal air monitoring during pregnancy, on the level of PAH-DNA adducts in a baby's cord blood is modified by the concentration of micronut...
4. Polycyclic aromatic hydrocarbon-DNA adducts in cervix of women infected with carcinogenic human papillomavirus types: An immunohistochemistry study
Energy Technology Data Exchange (ETDEWEB)
Pratt, M. Margaret [Carcinogen-DNA Interactions Section, LCBG, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD (United States)], E-mail: prattm@mail.nih.gov; Sirajuddin, Paul; Poirier, Miriam C. [Carcinogen-DNA Interactions Section, LCBG, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD (United States); Schiffman, Mark [Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD (United States); Glass, Andrew G.; Scott, David R.; Rush, Brenda B. [Northwest Kaiser Permanente, Portland, OR (United States); Olivero, Ofelia A. [Carcinogen-DNA Interactions Section, LCBG, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD (United States); Castle, Philip E. [Hormonal and Reproductive Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD (United States)
2007-11-01
5. Bulky carcinogen-DNA adducts and exposure to environmental and occupational sources of polycyclic aromatic hydrocarbons. Influence of susceptibility genotypes on adduct level
International Nuclear Information System (INIS)
PAH exposure, whether it is of occupational or environmental origin, is thought to result in an elevated risk of cancer especially in the lungs. DNA damage is considered an important step in the carcinogenic effect of PAH. Hence, methods that elucidate the steps in the carcinogenic process are important to understand the action of PAH. It may prove useful in the exposure assessment and in combination with classical epidemiological methods give better basis for risk estimation. The objective in this thesis was to evaluate the feasibility of the 32P-postlabeling method to detect carcinogen-DNA adducts for assessing exposure to DNA damaging compounds in different occupationally and environmentally exposed groups. The studies included groups, that have an elevated cancer risk due to occupational exposure to PAH. Exposure levels were supposed to be relatively low according to reports on occupational and environmental air quality programs. Another aim was to evaluate the influence of polymorphisms in metabolizing enzyme genes on DNA adduct levels. A third objective was to establish some kind of baseline DNA adduct level for individuals with supposed low exposure, and compare it to the more exposed groups. A fourth aim in these studies was to examine if biomarkers of genotoxic exposure could be useful in epidemiological studies to identify groups at risk and thereby contribute with better exposure estimates in the study of PAH related cancer risk. (EG)
6. Bulky carcinogen-DNA adducts and exposure to environmental and occupational sources of polycyclic aromatic hydrocarbons. Influence of susceptibility genotypes on adduct level
Energy Technology Data Exchange (ETDEWEB)
Sabro Nielsen, P.
1996-12-31
PAH exposure, whether it is of occupational or environmental origin, is thought to result in an elevated risk of cancer especially in the lungs. DNA damage is considered an important step in the carcinogenic effect of PAH. Hence, methods that elucidate the steps in the carcinogenic process are important to understand the action of PAH. It may prove useful in the exposure assessment and in combination with classical epidemiological methods give better basis for risk estimation. The objective in this thesis was to evaluate the feasibility of the {sup 32}P-postlabeling method to detect carcinogen-DNA adducts for assessing exposure to DNA damaging compounds in different occupationally and environmentally exposed groups. The studies included groups, that have an elevated cancer risk due to occupational exposure to PAH. Exposure levels were supposed to be relatively low according to reports on occupational and environmental air quality programs. Another aim was to evaluate the influence of polymorphisms in metabolizing enzyme genes on DNA adduct levels. A third objective was to establish some kind of baseline DNA adduct level for individuals with supposed low exposure, and compare it to the more exposed groups. A fourth aim in these studies was to examine if biomarkers of genotoxic exposure could be useful in epidemiological studies to identify groups at risk and thereby contribute with better exposure estimates in the study of PAH related cancer risk. (EG).
7. Photochemical Reaction of 7,12-Dimethylbenz[a]anthracene (DMBA and Formation of DNA Covalent Adducts
Directory of Open Access Journals (Sweden)
Peter P. Fu
2005-04-01
8. Mutagenic properties of the 8-amino-2'-deoxyguanosine DNA adduct in mammalian cells.
OpenAIRE
X. Tan; Suzuki, N; Johnson, F; Grollman, A P; Shibutani, S
1999-01-01
The DNA adduct 8-amino-2'-deoxyguanosine (8-amino-dG) is found in liver DNA of rats treated with the hepatocarcinogen 2-nitropropane. Site-specifically modified oligodeoxynucleotides were used to explore the mutagenic potential of 8-amino-dG in simian kidney (COS-7) cells. Oligodeoxynucleotides (5'-TCCTCCTX1G2CCTCTC and 5'-TCCTCCTG1X2CCTCTC, X = dG or 8-amino-dG) with the lesion positioned at codon 60 or 61 of the non-coding strand of the human c-Ha- ras1 gene were inserted into single-strand...
9. Formation and persistence of sterigmatocystin-DNA adducts in rat liver determined via 32P-postlabeling analysis
International Nuclear Information System (INIS)
A 32P-postlabeling method has been employed to detect the in vitro and in vivo modification of DNA by the mycotoxin sterigmatocystin (ST). Dose-dependent ST-DNA adduct formation was detected in the liver of male Fischer 344 rats over a 27-fold range of ST administered. In addition, ST-DNA adducts, formed in rats given a 9 mg/kg dose, were found to persist up to 105 days after treatment at a level of 0.5% of the 2-h value. Loss of these adducts from liver DNA was observed to exhibit a triphasic profile: rapid loss during the first 24 h followed by a slower decline from 1 to 14 days post dosing and an extremely slow decline from day 14 to 105 post treatment. This experimental approach to the study of mycotoxin-DNA interactions permits the quantitative description of DNA modification in ST-treated animals. (Auth.)
10. Surface area as a dose metric for carbon black nanoparticles: A study of oxidative stress, DNA single-strand breakage and inflammation in rats
Science.gov (United States)
Chuang, Hsiao-Chi; Chen, Li-Chen; Lei, Yu-Chen; Wu, Kuen-Yuh; Feng, Po-Hao; Cheng, Tsun-Jen
2015-04-01
Combustion-derived nanoparticles are characterised by a high surface area (SA) per mass. SA is proposed to regulate the bioreactivity of nanoparticles; however, the dose metric for carbon black remains controversial. To determine the relationships between bioreactivity and SA, male spontaneously hypertensive rats were exposed to carbon black (CB) nanoparticles (15, 51 and 95 nm) via intratracheal instillation for 24 h. Pulmonary exposure to CB resulted in a significant increase in systemic 8-hydroxy-2‧-deoxyguanosine (8-OHdG), DNA single-strand breakages in peripheral blood cells and pulmonary cell infiltration in rats. The oxidative potential and particularly the corresponding SA of CB were correlated with the level of 8-OHdG, DNA single-strand breakages and pulmonary cell infiltration in rats. We conclude that SA is an important dose metric for CB that can regulate oxidative stress and DNA damage in rats. Furthermore, this observation was more significant for smaller sized CB.
11. 5-bp Classical Satellite DNA Loci from Chromosome-1 Instability in Cervical Neoplasia Detected by DNA Breakage Detection/Fluorescence in Situ Hybridization (DBD-FISH
Directory of Open Access Journals (Sweden)
Jaime Gosálvez
2013-02-01
Full Text Available We aimed to evaluate the association between the progressive stages of cervical neoplasia and DNA damage in 5-bp classical satellite DNA sequences from chromosome-1 in cervical epithelium and in peripheral blood lymphocytes using DNA breakage detection/fluorescence in situ hybridization (DBD-FISH. A hospital-based unmatched case-control study was conducted in 2011 with a sample of 30 women grouped according to disease stage and selected according to histological diagnosis; 10 with low-grade squamous intraepithelial lesions (LG-SIL, 10 with high-grade SIL (HG-SIL, and 10 with no cervical lesions, from the Unidad Medica de Alta Especialidad of The Mexican Social Security Institute, IMSS, Mexico. Specific chromosome damage levels in 5-bp classical satellite DNA sequences from chromosome-1 were evaluated in cervical epithelium and peripheral blood lymphocytes using the DBD-FISH technique. Whole-genome DNA hybridization was used as a reference for the level of damage. Results of Kruskal-Wallis test showed a significant increase according to neoplastic development in both tissues. The instability of 5-bp classical satellite DNA sequences from chromosome-1 was evidenced using chromosome-orientation FISH. In conclusion, we suggest that the progression to malignant transformation involves an increase in the instability of 5-bp classical satellite DNA sequences from chromosome-1.
12. Iodine-125 induced DNA strand breakage: Contributions of different physical and chemical radiation action mechanisms
International Nuclear Information System (INIS)
The decay of the radioisotope 125I into 125Te is typically followed by the emission of two groups of approximately 10 electrons each. In deoxyribonucleic acid (DNA) with 125I incorporated, these electrons produce various types of damage to DNA, e.g. single and double strand breaks. They occur through direct actions of physical tracks, or indirect actions of radicals produced in water. Among the direct actions one should consider not only the excitation and ionization of DNA by electrons but also the neutralization of highly charged 125mTe ions with electrons from neighboring molecules. The present work begins with a detailed description of electron tracks with the use of the PARTRAC code, compares results with recent experiments, and concludes with a firm assessment of the contribution to the strand break yields from the neutralization effect. (orig.)
13. Polychlorinated Biphenyls Induce Oxidative DNA Adducts in Female Sprague-Dawley Rats.
Science.gov (United States)
Mutlu, Esra; Gao, Lina; Collins, Leonard B; Walker, Nigel J; Hartwell, Hadley J; Olson, James R; Sun, Wei; Gold, Avram; Ball, Louise M; Swenberg, James A
2016-08-15
Polychlorinated biphenyls (PCBs) are organic chemicals that were traditionally produced and widely used in industry as mixtures and are presently formed as byproducts of pigment and dye manufacturing. They are known to persist and bioaccumulate in the environment. Some have been shown to induce liver cancer in rodents. Although the mechanism of the toxicity of PCBs is unknown, it has been shown that they increase oxidative stress, including lipid peroxidation. We hypothesized that oxidative stress-induced DNA damage could be a contributor for PCB carcinogenesis and analyzed several DNA adducts in female Sprague-Dawley rats exposed to 3,3',4,4',5-pentachlorobiphenyl (PCB 126), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), and a binary mixture (PCB 126 + 153) for 14, 31, and 53 wks. Eight adducts were measured to profile oxidative DNA lesions, including 8-oxo-deoxyguanosine (8-oxo-dG), 1,N(6)-ethenodeoxyadenosine (1,N(6)-εdA), N(2),3-ethenoguanine (N(2),3-εG), 1,N(2)-ethenodeoxyguanosine (1,N(2)-εdG), as well as malondialdehyde (M1dG), acrolein (AcrdG), crotonaldehyde (CrdG), and 4-hydroxynonenal-derived dG adducts (HNEdG) by LC-MS/MS analysis. Statistically significant increases were observed for 8-oxo-dG and 1,N(6)-εdA concentrations in hepatic DNA of female rats exposed to the binary mixture (1000 ng/kg/day + 1000 μg/kg/day) but not in rats exposed to PCB 126 (1000 ng/kg/day) or PCB 153 (1000 μg/kg/day) for 14 and 31 wks. However, exposure to PCB 126 (1000 ng/kg/day) for 53 wks significantly increased 8-oxo-dG, 1,N(6)-εdA, AcrdG, and M1dG. Exposure to PCB 153 (1000 μg/kg/day) for 53 wks increased 8-oxo-dG, and 1,N(6)-εdA. Exposure to the binary mixture for 53 wks increased 8-oxo-dG, 1,N(6)-εdA, AcrdG, 1,N(2)-εdG, and N(2),3-εG significantly above control groups. Increased hepatic oxidative DNA adducts following exposure to PCB 126, PCB 153, or the binary mixture shows that an increase in DNA damage may play an important role in hepatic toxicity and
14. The potential of platinum-DNA adduct determination in ex vivo treated tumor fragments for the prediction of sensitivity to cisplatin chemotherapy
NARCIS (Netherlands)
Welters, M.J.P.; Braakhuis, B.J.M.; Jacobs-Bergmans, A.J.; Kegel, A.; Baan, R.A.; Vijgh, W.J.F. van der; Fichtinger-Schepman, A.M.J.
1999-01-01
Background: Response to cisplatin-therapy is assumed to be related to the formation of platinum (Pt)-DNA adducts. Measurement of these adducts prior to therapy could be of value to improve cisplatin based cancer therapy. Materials and methods: We determined Pt-GG and Pt-AG adduct levels by use of 32
15. Recognition and repair of the CC-1065-(N3-Adenine)-DNA adduct by the UVRABC nuclease
Energy Technology Data Exchange (ETDEWEB)
Tang, M.; Lee, C.S.; Doisy, R.; Ross, L.; Needham-VanDevanter, D.R.; Hurley, L.H.
1988-02-09
The recognition and repair of the helix-stabilizing and relatively nondistortive CC-1065-(N3-adenine)-DNA adduct by UVRABC nuclease has been investigated both in vivo with phi X174RFI DNA by a transfection assay and in vitro by a site-directed adduct in a 117 base pair fragment from M13mp1. CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis which binds within the minor groove of DNA through N3 of adenine. In contrast to the helix-destabilizing and distortive modifications of DNA caused by ultraviolet light or N-acetoxy-2-(acetylamino)fluorene, CC-1065 increases the melting point of DNA and decreases the S1 nuclease activity. Using a viral DNA-Escherichia coli transfection system, the authors have found that the uvrA, uvrB, and uvrC genes, which code for the major excision repair proteins for UV- and NAAAF-induced DNA damage, are also involved in the repair of CC-1065-DNA adducts. In contrast, the uvrD gene product, which has been found to be involved in the repair of UV damage, has no effect in repairing CC-1065-DNA adducts. Purified UVRA, UVRB, and UVRC proteins must work in concert to incise the drug-modified phi X174RFI DNA. Using a site-directed and multiple CC-1065 modified (MspI-BstNI) 117 base pair fragment from M13mp1, they have found that UVRABC nuclease incises at the eight phosphodiester bond on the 5' side of the CC-1065-DNA adduct on the drug-modified strand. The enzymes do not cut the noncovalently modified strand. The DNA sequence and/or helix-stabilizing effect of multiple adducts may determine the recognition and/or incision of the drug-DNA adduct by UVRABC nuclease. These results are discussed in relation to the structure of the CC-1065-DNA adduct and the effect of drug binding on local DNA structure.
16. Recognition and repair of the CC-1065-(N3-Adenine)-DNA adduct by the UVRABC nuclease
International Nuclear Information System (INIS)
The recognition and repair of the helix-stabilizing and relatively nondistortive CC-1065-(N3-adenine)-DNA adduct by UVRABC nuclease has been investigated both in vivo with phi X174RFI DNA by a transfection assay and in vitro by a site-directed adduct in a 117 base pair fragment from M13mp1. CC-1065 is a potent antitumor antibiotic produced by Streptomyces zelensis which binds within the minor groove of DNA through N3 of adenine. In contrast to the helix-destabilizing and distortive modifications of DNA caused by ultraviolet light or N-acetoxy-2-(acetylamino)fluorene, CC-1065 increases the melting point of DNA and decreases the S1 nuclease activity. Using a viral DNA-Escherichia coli transfection system, the authors have found that the uvrA, uvrB, and uvrC genes, which code for the major excision repair proteins for UV- and NAAAF-induced DNA damage, are also involved in the repair of CC-1065-DNA adducts. In contrast, the uvrD gene product, which has been found to be involved in the repair of UV damage, has no effect in repairing CC-1065-DNA adducts. Purified UVRA, UVRB, and UVRC proteins must work in concert to incise the drug-modified phi X174RFI DNA. Using a site-directed and multiple CC-1065 modified (MspI-BstNI) 117 base pair fragment from M13mp1, they have found that UVRABC nuclease incises at the eight phosphodiester bond on the 5' side of the CC-1065-DNA adduct on the drug-modified strand. The enzymes do not cut the noncovalently modified strand. The DNA sequence and/or helix-stabilizing effect of multiple adducts may determine the recognition and/or incision of the drug-DNA adduct by UVRABC nuclease. These results are discussed in relation to the structure of the CC-1065-DNA adduct and the effect of drug binding on local DNA structure
17. Modulatory effects of essential oils from spices on the formation of DNA adduct by aflatoxin B1 in vitro.
Science.gov (United States)
Hashim, S; Aboobaker, V S; Madhubala, R; Bhattacharya, R K; Rao, A R
1994-01-01
Essential oils from common spices such as nutmeg, ginger, cardamom, celery, xanthoxylum, black pepper, cumin, and coriander were tested for their ability to suppress the formation of DNA adducts by aflatoxin B1 in vitro in a microsomal enzyme-mediated reaction. All oils were found to inhibit adduct formation very significantly and in a dose-dependent manner. The adduct formation appeared to be modulated through the action on microsomal enzymes, because an effective inhibition on the formation of activated metabolite was observed with each oil. The enzymatic modulation is perhaps due to the chemical constituents of the oils, and this could form a basis for their potential anticarcinogenic roles. PMID:8058527
18. Prenatal diagnosis of ataxia-telangiectasia and Nijmegen Breakage Syndrome by the assay of radioresistant DNA synthesis
International Nuclear Information System (INIS)
Prenatal diagnosis was performed in 16 pregnancies at risk of ataxia-telangiectasia (A-T) or Nijmegen Breakage Syndrome (NBS). Radioresistant DNA synthesis (RDS) was investigated in cultured chorionic villus (CV) cells and/or amniotic fluid (AF) cells. In four pregnancies, an affected foetus was diagnosed with increased RDS in cultured CV cells. In three of the four cases confirmation of the diagnosis was obtained by analysis of AF cells and/or skin fibroblasts from the foetus cultured after termination of the pregnancy; in the fourth case a fibroblast culture from the aborted foetus failed. In one case, only AF cells could be analysed in a late stage of pregnancy; pregnancy was terminated due to intermediate/equivocal results but the foetus fibroblasts showed normal RDS. Normal RDS was demonstrated in the other 11 pregnancies at 25% risk either by analysis of CB cells (nine cases) or of AF cells (two cases). In some cases the (normal) results on the CV cells were corroborated by subsequent analysis of Af cells. The results suggest that RDS analysis of CV cells allows reliable prenatal diagnosis of A-T/NBS. However, amniocentesis may be necessary to confirm normal results on CV cells if the foetus is female (because of the risk of maternal cell contamination) or in the rare case of equivocal results. (author)
19. DNA Amplification by Breakage/Fusion/Bridge Cycles Initiated by Spontaneous Telomere Loss in a Human Cancer Cell Line
Directory of Open Access Journals (Sweden)
Anthony W.l. Lo
2002-01-01
Full Text Available The development of genomic instability is an important step in generatingthe multiple genetic changes required for cancer. One consequence of genomic instability is the overexpression of oncogenes due to gene amplification. One mechanism for gene amplification is the breakagelfusionlbridge (B/F/Bcyclethatinvolvesthe repeated fusion and breakage of chromosomes following the loss of a telomere. B/F/B cycles have been associated with low-copy gene amplification in human cancer cells, and have been proposed to be an initiating event in high-copy gene amplification. We have found that spontaneous telomere loss on a marker chromosome 16 in a human tumor cell line results in sister chromatid fusion and prolonged periods of chromosome instability. The high rate of anaphase bridges involving chromosome 16 demonstrates that this instability results from B/F/B cycles. The amplification of subtelomeric DNA on the marker chromosome provides conclusive evidence that B/F/B cycles initiated by spontaneous telomere loss are a mechanism for gene amplification in human cancer cells.
20. Use of the DBD-FISH technique for detecting DNA breakage in response to high doses of X-rays.
Science.gov (United States)
Cortés-Gutiérrez, Elva I; Dávila-Rodríguez, Martha I; Cerda-Flores, Ricardo M; Fernández, José Luis; López-Fernández, Carmen; Gosálvez, Jaime
2014-11-01
The aim of this study was to generate a dose-response curve using the DNA breakage detection-fluorescent in situ hybridization (DBD-FISH) test as a biomarker of initial genetic effects induced by high doses of X-rays. A dose-response curve was obtained by measuring the ex vivo responses to increasing doses (0-50 Gy) of X-rays in the peripheral blood lymphocytes of ten healthy donors. The overall dose-response curve was constructed using integrated density (ID; area × fluorescence intensity) as a measure of genetic damage induced by irradiation. The correlation coefficient was high (r = 0.934, b(0) = 10.408, and b(1) = 0.094). One-way ANOVA with the Student-Newman-Keuls test for multiple comparisons showed significant differences among the average ln ID values according to dose. Our results suggest the usefulness of the DBD-FISH technique for measuring intrinsic individual cellular radio sensitivity ex vivo.
1. Prenatal diagnosis of ataxia-telangiectasia and Nijmegen Breakage Syndrome by the assay of radioresistant DNA synthesis
Energy Technology Data Exchange (ETDEWEB)
Kleijer, W.J.; Kraan, M. van der; Los, F.J. [Erasmus Univ., Rotterdam (Netherlands). Dept. of Clinical Genetics; Jaspers, N.G.J. [Erasmus Univ., Rotterdam (Netherlands). Lab. of Cell Biology and Genetics
1994-12-01
Prenatal diagnosis was performed in 16 pregnancies at risk of ataxia-telangiectasia (A-T) or Nijmegen Breakage Syndrome (NBS). Radioresistant DNA synthesis (RDS) was investigated in cultured chorionic villus (CV) cells and/or amniotic fluid (AF) cells. In four pregnancies, an affected foetus was diagnosed with increased RDS in cultured CV cells. In three of the four cases confirmation of the diagnosis was obtained by analysis of AF cells and/or skin fibroblasts from the foetus cultured after termination of the pregnancy; in the fourth case a fibroblast culture from the aborted foetus failed. In one case, only AF cells could be analysed in a late stage of pregnancy; pregnancy was terminated due to intermediate/equivocal results but the foetus fibroblasts showed normal RDS. Normal RDS was demonstrated in the other 11 pregnancies at 25% risk either by analysis of CB cells (nine cases) or of AF cells (two cases). In some cases the (normal) results on the CV cells were corroborated by subsequent analysis of Af cells. The results suggest that RDS analysis of CV cells allows reliable prenatal diagnosis of A-T/NBS. However, amniocentesis may be necessary to confirm normal results on CV cells if the foetus is female (because of the risk of maternal cell contamination) or in the rare case of equivocal results. (author).
2. Mechanism of Translesion Synthesis Past an Equine Estrogen-DNA Adduct by Y-Family DNA Polymerases
OpenAIRE
Yasui, Manabu; Suzuki, Naomi; Liu, Xiaoping; Kim, Yoshinori Okamoto Sung Yeon; Laxmi, Y. R. Santosh; Shibutani, Shinya
2007-01-01
4-Hydroxyequilenin (4-OHEN)-dC is a major, potentially mutagenic DNA adduct induced by equine estrogens used for hormone replacement therapy. To study the miscoding property of 4-OHEN-dC and the involvement of Y-family human DNA polymerases (pols) η, κ and ι in that process, we incorporated 4-OHEN-dC into oligodeoxynucleotides and used them as templates in primer extension reactions catalyzed by pol η, κ and ι. Pol η inserted dAMP opposite 4-OHEN-dC, accompanied by lesser amounts of dCMP and ...
3. Malabaricone C-containing mace extract inhibits safrole bioactivation and DNA adduct formation both in vitro and in vivo
NARCIS (Netherlands)
Martati, E.; Boonpawa, R.; Berg, van den J.H.J.; Paini, A.; Spenkelink, A.; Punt, A.; Vervoort, J.J.M.; Bladeren, van P.J.; Rietjens, I.
2014-01-01
Safrole, present in mace and its essential oils, causes liver tumors in rodents at high dose levels due to formation of a DNA reactive 1'-sulfooxysafrole. The present study identifies malabaricone C as a mace constituent able to inhibit safrole DNA adduct formation at the level of sulfotransferase m
4. Myeloperoxidase - 463A variant reduces benzo(a)pyrene diol epoxide DNA adducts in skin of coal tar treated patients
Energy Technology Data Exchange (ETDEWEB)
Rojas, M.; Godschalk, R.; Alexandrov, K.; Cascorbi, I.; Kriek, E.; Ostertag, J.; Van Schooten, F.J.; Bartsch, H. [German Cancer Research Center, Heidelberg (Germany). Div. of Toxicology & Cancer Risk Factors
2001-07-01
The skin of atopic dermatitis patients provides an excellent model to study the role of inflammation in benzo(a)pyrene (BaP) activation, since these individuals are often topically treated with ointments containing high concentrations of BaP. The authors determined, by HPLC with fluorescence detection, the BaP diol epoxide (BPDE)-DNA adduct levels in human skin after topical treatment with coal tar and their modulation by the -453G into A myeloperoxidase (MPO) polymorphism, which reduces MPO mRNA expression. The data show for the first time: (i) the in vivo formation of BPDE-DNA adducts in human skin treated with coal tar; (ii) that the MPO-463AA/AG genotype reduced BPDE-DNA adduct levels in human skin.
5. Formation of 1,4-dioxo-2-butene-derived adducts of 2′-deoxyadenosine and 2′-deoxycytosine in oxidized DNA
OpenAIRE
Chen, Bingzi; Vu, Choua C.; Byrns, Michael C.; Peter C. Dedon; Peterson, Lisa A.
2006-01-01
Oxidation of deoxyribose in DNA produces a variety of electrophilic residues that are capable of reacting with nucleobases to form adducts such as M1dG, the pyrimidopurinone adduct of dG. We now report that deoxyribose oxidation in DNA leads to the formation of oxadiazabicyclo(3.3.0)octaimine adducts of dC and dA. We previously demonstrated that these adducts arise in reactions of nucleosides and DNA with trans-1,4-dioxo-2-butene, the β-elimination product of the 2-phosphoryl-1,4-dioxobutane ...
6. 2-Aminofluorene metabolism and DNA adduct formation by mononuclear leukocytes from rapid and slow acetylator mouse strains.
Science.gov (United States)
Levy, G N; Chung, J G; Weber, W W
1994-02-01
7. Structure of DNA polymerase β with a benzo[c]phenanthrene diol epoxide-adducted template exhibits mutagenic features
OpenAIRE
Batra, Vinod K.; Shock, David D.; Prasad, Rajendra; BEARD, WILLIAM A.; Hou, Esther W.; Pedersen, Lars C.; Sayer, Jane M.; Yagi, Haruhiko; Kumar, Subodh; Jerina, Donald M.; Wilson, Samuel H.
2006-01-01
We have determined the crystal structure of the human base excision repair enzyme DNA polymerase β (Pol β) in complex with a 1-nt gapped DNA substrate containing a template N2-guanine adduct of the tumorigenic (−)-benzo[c]phenanthrene 4R,3S-diol 2S,1R-epoxide in the gap. Nucleotide insertion opposite this adduct favors incorrect purine nucleotides over the correct dCMP and hence can be mutagenic. The structure reveals that the phenanthrene ring system is stacked with the base pair immediately...
8. Safrole-DNA adducts in tissues from esophageal cancer patients: clues to areca-related esophageal carcinogenesis.
Science.gov (United States)
Lee, Jang-Ming; Liu, Tsung-Yung; Wu, Deng-Chyang; Tang, Hseau-Chung; Leh, Julie; Wu, Ming-Tsang; Hsu, Hsao-Hsun; Huang, Pei-Ming; Chen, Jin-Shing; Lee, Chun-Jean; Lee, Yung-Chie
2005-01-01
Epidemiological studies have demonstrated that areca quid chewing can be an independent risk factor for developing esophageal cancer. However, no studies are available to elucidate the mechanisms of how areca induces carcinogenesis in the esophagus. Since the areca nut in Taiwan contains a high concentration of safrole, a well-known carcinogenic agent, we analyzed safrole-DNA adducts by the 32P-postlabelling method in tissue specimens from esophageal cancer patients. In total, we evaluated 47 patients with esophageal cancer (16 areca chewers and 31 non-chewers) who underwent esophagectomy at the National Taiwan University Hospital between 1996 and 2002. Of the individuals with a history of habitual areca chewing (14 cigarette smokers and two non-smokers), one of the tumor tissue samples and five of the normal esophageal mucosa samples were positive for safrole-DNA adducts. All patients positive for safrole-DNA adducts were also cigarette smokers. Such adducts could not be found in patients who did not chew areca, irrespective of their habits of alcohol consumption or cigarette smoking (psafrole was also tested in vitro in three esophageal cell lines and four cultures of primary esophageal keratinocytes. In two of the esophageal keratinocyte cultures, adduct formation was increased by treatment with safrole after induction of cytochrome P450 by 3-methyl-cholanthrene. This paper provides the first observation of how areca induces esophageal carcinogenesis, i.e., through the genotoxicity of safrole, a component of the areca juice.
9. Increased sensitivity for determination of polycyclic aromatic hydrocarbon-DNA adducts in human DNA samples by dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA).
Science.gov (United States)
Schoket, B; Doty, W A; Vincze, I; Strickland, P T; Ferri, G M; Assennato, G; Poirier, M C
1993-01-01
A competitive enzyme-linked immunosorbent assay (ELISA), the most frequently used immunoassay for the determination of polycyclic aromatic hydrocarbon-DNA adducts in human tissues, has been modified to achieve approximately a 6-fold increase in sensitivity. The new assay, a competitive dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA) has utilized the same rabbit antiserum as the ELISA, antiserum elicited against DNA modified with benzo[a]pyrene. However, the alkaline phosphatase conjugate has been replaced with a biotin-europium-labeled streptavidin signal amplification system, and the release of europium into the solution forms a highly fluorescent chelate complex that is measured by time-resolved fluorometry. The DELFIA has achieved a 5- to 6-fold increase in sensitivity for measurement of DNA samples modified in vitro with benzo[a]pyrene, for cultured cells exposed to radiolabeled benzo[a]pyrene, and for human samples from occupationally exposed workers. The assay has been validated by comparison of adduct levels determined by DELFIA, ELISA, and radioactivity in DNA from mouse keratinocytes exposed to radiolabeled benzo[a]pyrene. Human lymphocyte DNA samples from 104 Hungarian aluminum plant workers were assayed by ELISA and compared to blood cell DNA samples from 69 Italian coke oven workers assayed by DELFIA. The standard curves demonstrated that the limit of detection of 4.0 adducts in 10(8) nucleotides for polycyclic aromatic hydrocarbon-DNA adducts by ELISA, using 35 micrograms of DNA/microtiter plate well, has been decreased to 1.3 adducts in 10(8) nucleotides by DELFIA, using 20 micrograms of DNA/microtiter well. If 35 micrograms of DNA were used in the DELFIA, the calculated detection limit would be 0.7 adducts in 10(8) nucleotides.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8348058
10. Benzene-derived N2-(4-hydroxyphenyl)-deoxyguanosine adduct: UvrABC incision and its conformation in DNA
Energy Technology Data Exchange (ETDEWEB)
Hang, Bo; Rodriguez, Ben; Yang, Yanu; Guliaev, Anton B.; Chenna, Ahmed
2010-06-14
Benzene, a ubiquitous human carcinogen, forms DNA adducts through its metabolites such as p-benzoquinone (p-BQ) and hydroquinone (HQ). N(2)-(4-Hydroxyphenyl)-2'-deoxyguanosine (N(2)-4-HOPh-dG) is the principal adduct identified in vivo by (32)P-postlabeling in cells or animals treated with p-BQ or HQ. To study its effect on repair specificity and replication fidelity, we recently synthesized defined oligonucleotides containing a site-specific adduct using phosphoramidite chemistry. We here report the repair of this adduct by Escherichia coli UvrABC complex, which performs the initial damage recognition and incision steps in the nucleotide excision repair (NER) pathway. We first showed that the p-BQ-treated plasmid was efficiently cleaved by the complex, indicating the formation of DNA lesions that are substrates for NER. Using a 40-mer substrate, we found that UvrABC incises the DNA strand containing N(2)-4-HOPh-dG in a dose- and time-dependent manner. The specificity of such repair was also compared with that of DNA glycosylases and damage-specific endonucleases of E. coli, both of which were found to have no detectable activity toward N(2)-4-HOPh-dG. To understand why this adduct is specifically recognized and processed by UvrABC, molecular modeling studies were performed. Analysis of molecular dynamics trajectories showed that stable G:C-like hydrogen bonding patterns of all three Watson-Crick hydrogen bonds are present within the N(2)-4-HOPh-G:C base pair, with the hydroxyphenyl ring at an almost planar position. In addition, N(2)-4-HOPh-dG has a tendency to form more stable stacking interactions than a normal G in B-type DNA. These conformational properties may be critical in differential recognition of this adduct by specific repair enzymes.
11. Space Radiation Effects on Human Cells: Modeling DNA Breakage, DNA Damage Foci Distribution, Chromosomal Aberrations and Tissue Effects
Science.gov (United States)
Ponomarev, A. L.; Huff, J. L.; Cucinotta, F. A.
2011-01-01
12. Increased levels of etheno-DNA adducts and genotoxicity biomarkers of long-term exposure to pure diesel engine exhaust.
Science.gov (United States)
Shen, Meili; Bin, Ping; Li, Haibin; Zhang, Xiao; Sun, Xin; Duan, Huawei; Niu, Yong; Meng, Tao; Dai, Yufei; Gao, Weimin; Yu, Shanfa; Gu, Guizhen; Zheng, Yuxin
2016-02-01
Etheno-DNA adducts are biomarkers for assessing oxidative stress. In this study, the aim was to detect the level of etheno-DNA adducts and explore the relationship between the etheno-DNA adducts and genotoxicity biomarkers of the diesel engine exhaust (DEE)-exposed workers. We recruited 86 diesel engine testing workers with long-term exposure to DEE and 99 non-DEE-exposed workers. The urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and etheno-DNA adducts (εdA and εdC) were detected by HPLC-MS/MS and UPLC-MS/MS, respectively. Genotoxicity biomarkers were also evaluated by comet assay and cytokinesis-block micronucleus assay. The results showed that urinary εdA was significantly higher in the DEE-exposed workers (p<0.001), exhibited 2.1-fold increase compared with the non-DEE-exposed workers. The levels of urinary OH-PAHs were positively correlated with the level of εdA among all the study subjects (p<0.001). Moreover, we found that the increasing level of εdA was significantly associated with the increased olive tail moment, percentage of tail DNA, or frequency of micronucleus in the study subjects (p<0.01). No significant association was observed between the εdC level and any measured genotoxicity biomarkers. In summary, εdA could serve as an indicator for DEE exposure in the human population. PMID:26588802
13. Association between plasma BPDE‐Alb adduct concentrations and DNA damage of peripheral blood lymphocytes among coke oven workers
Science.gov (United States)
Wang, Hong; Chen, Weihong; Zheng, Hongyan; Guo, Liang; Liang, Huashan; Yang, Xiaobo; Bai, Yun; Sun, Jianya; Su, Yougong; Chen, Yongwen; Yuan, Jing; Bi, Yongyi; Wei, Qingyi; Wu, Tangchun
2007-01-01
Objectives Coke oven emissions (COE) containing polycyclic aromatic hydrocarbons (PAHs) can induce both benzo[a]pyrene‐r‐7, t‐8, t‐9,c‐10‐tetrahydotetrol‐albumin (BPDE‐Alb) adducts and DNA damage. However, the relation between these biomarkers for early biological effects is not well documented in coke oven workers. Methods In this study, the authors recruited 207 male workers exposed to COE and 102 controls not exposed to COE in the same steel plant in northern China. They measured BPDE‐Alb adduct concentrations in plasma with reverse‐phase high performance liquid chromatography and DNA damage in peripheral blood lymphocytes with alkaline comet assay. Results The results showed that the median concentration of BPDE‐Alb adducts in the exposed group (34.36 fmol/mg albumin) was significantly higher than that in the control group (21.90 fmol/mg albumin, p = 0.012). The mean Olive tail moment (Olive TM) of DNA damage in the exposed and control groups were 1.20 and 0.63, respectively (p = 0.000). Multivariate logistic regression analysis revealed that the odds ratio (OR) for BPDE‐Alb adduct and Olive TM associated with the exposure were 1.72 (95% CI 1.06 to 2.81) and 1.96 (95% CI 1.20 to 3.19), respectively. These results show significant correlations between the concentrations of BPDE‐Alb adduct and Olive TM levels in exposed group (r = 0.235, p = 0.001) but not in control group (r = 0.093, p = 0.353). Conclusion The results suggest that occupational exposure to COE may induce both BPDE–Alb adducts and DNA damage in the lymphocytes of coke oven workers and that these two markers are useful for monitoring exposure to COE in the workplace. PMID:17449561
14. Comparative synchronous fluorescence spectrophotometry and 32P-postlabeling analysis of PAH-DNA adducts in human lung and the relationship to TP53 mutations
DEFF Research Database (Denmark)
Andreassen, Åshild; Kure, Elin H.; Nielsen, Per Sabro;
1996-01-01
Polycyclic aromatic hydrocarbon (PAH)-DNA adducts were studied in human lung from 39 lung cancer patients by synchronous fluorescence spectrophotometric (SFS) and 32P-postlabeling assays. Regression analysis of the samples failed to detect any correlation between benzo[a]pyrene-diolepoxide (BPDE......)-DNA adducts detected by SFS and the BPDE co-migrating spot detected by 32P-postlabeling. We have also analyzed the relationship between adduct levels and TP53 mutations. By postlabeling diagonal radioactive zone (DRZ) adducts were detected in 37 of 39 (95%) lung tissues from lung cancer patients...
15. Two food-borne heterocyclic amines: Metabolism and DNA adduct formation of amino-alpha-carbolines
DEFF Research Database (Denmark)
Frederiksen, Hanne
2005-01-01
or proteins of animal or vegetable origin, furthermore they are found in many cooked foods, such as fish, meat, and chicken. The specific mutagenicity of the amino-a-carbolines are lower in the Ames Salmonella assay than other heterocyclic amines, but in rodent studies the carcinogenicity of the aminoa, alpha...... been studied. Characteristic for the amino-a-carbolines are that relatively large amounts of these compounds in rat and human hepatic microsomes are activated to potent carcinogenic compounds compared with other heterocyclic amines, but further in vivo studies of the amino-a-carbolines are needed...... to highlight these indications. In this review, the main characteristics with focus on the metabolism and the DNA-adduct formation of the amino-a-carbolines are described and compared with other heterocyclic amines....
16. Maternal diet and dioxin-like activity, bulky DNA adducts and micronuclei in mother newborns
DEFF Research Database (Denmark)
Pedersen, Marie; Halldorsson, Thorhallur I; Autrup, Herman;
2012-01-01
Maternal diet can contribute to carcinogenic exposures and also modify effects of environmental exposures on maternal and fetal genetic stability. In this study, associations between maternal diet and the levels of dioxin-like plasma activity, bulky DNA adducts in white blood cells and micronuclei...... (MN) in lymphocytes from mother to newborns were examined. From 98 pregnant women living in the greater area of Copenhagen, Denmark in 2006-2007, maternal peripheral blood and umbilical cord blood were collected, together with information on health, environmental exposure and lifestyle. Maternal diet...... was estimated on the basis of maternal food frequency questionnaire (FFQ) completed by the end of pregnancy. Biomarkers were detected in paired blood samples through the dioxin-responsive chemical-activated luciferase expression (CALUX)(®) bioassay, (32)P-postlabelling technique and cytokinesis-block MN assay...
17. Inhibition of azoxymethane-induced DNA adduct formation by Aloe arborescens var. natalensis.
Science.gov (United States)
Shimpo, Kan; Chihara, Takeshi; Beppu, Hidehiko; Ida, Chikako; Kaneko, Takaaki; Hoshino, Motoyuki; Kuzuya, Hiroshi
2003-01-01
To clarify the possible mechanisms of inhibition of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in the rat colorectum by freeze-dried whole leaves of Aloe arborescens var. natalensis (Kidachi aloe) (hereinafter referred to as ALOE) and commercial crude aloin (Sigma A-0451; from Curacao aloe) (hereinafter ALOIN), we studied the effects of ALOE and ALOIN on the formation of AOM-induced DNA adducts (O6-methylguanine; O6-MeG) in rats. Male F344 rats (4 weeks old) were fed a basal diet, or experimental diets containing 5%ALOE or 0.25%ALOIN for 5 weeks. All rats were injected s.c. twice with 15 mg/kg AOM, once at the end of week 1, and once at the end of week 2. The animals were sacrificed 6 hours after the second injection to analyze DNA adducts (O6-MeG) in the colorectum. Dietary administration of ALOE significantly inhibited the O6-MeG levels (50% reduction) compared with controls, whereas the O6-MeG levels in the ALOIN-fed rats showed a tendency to decrease (by 30%), although not significantly. In this study, we also measured the enzyme activity and mRNA level of cytochrome (CYP) 2E1, known to be responsible for the activation of AOM, in rat liver. ALOE-fed rats showed significantly reduced CYP2E1 enzymatic activity (27% reduction) compared with controls. On the other hand, the activity in ALOIN-fed rats tended to decrease by 11%, although not significantly. The CYP2E1 mRNA levels in ALOE- and ALOIN-fed rats were slightly reduced (9.7% and 5.2%, respectively). These results may explain, at least in part, the previously observed inhibitory effects of ALOE and ALOIN, especially ALOE on AOM-induced ACF formation in the rat colorectum. PMID:14507246
18. Isolation and identification of the adducts of mitomycin C and porfiromycin with DNA formed in vitro and in vivo
Energy Technology Data Exchange (ETDEWEB)
Chowdary, D.R.
1989-01-01
The antitumor antibiotics, mitomycin C (MC) and porfiromycin (PM), are shown to form covalent complexes with DNA in vitro, under reductive activation conditions (both chemical and enzymatic). Three major covalent adducts have been isolated and identified as (1) N{sup 2}-guanine adduct with MC (structure 4a), (2) N{sup 2}-guanine adduct with 10-decarbamoyl mitomycin ((10-DMC); structure 16a), and a bisadduct of MC linked to two Gs at their N{sup 2}-positions (structure 6). The adducts of PM with DNA formed in vitro are analogous (structures 19, 20, and 21). Formation of adducts 6 and 16a in CHO mammalian cells has been shown after exposing them to MC or 10-DMC, whereas formation of crosslink 6 in vivo has been demonstrated after injecting rats with MC. The experiments done in tissue cultures with (1a-{sup 3}H)-polyfiromycin show ({sup 3}H)-label in the unmodified A, G, and T thus suggesting the demethylation of PM to MC in cells. The methyl group containing ({sup 3}H) label was incorporated into nucleosides via de novo purine and thymidylate biosynthesis. A consolidated enzymatic scheme for the hydrolysis of MC-modified DNA has been established and the resistance of such DNA to cleavage by several nucleases has been shown. Thus, only DNase I/SVD/alkaline phosphatase or nuclease P{sub 1}/SVD/alkaline phosphatase combinations can degrade MC-modified DNA into nucleosides. A modified version of {sup 32}P-postlabeling has been developed with in vitro authentic standards and this can be conveniently used in the future to detect MC-modified lesions obtained in vivo. By utilizing the alkaline ethidium bromide fluorescence assay, the crosslinking effect of MC, PM, and 10-DMC has been shown to occur in cells.
19. Etheno-DNA adduct formation in rats gavaged with linoleic acid, oleic acid and coconut oil is organ- and gender specific
International Nuclear Information System (INIS)
Intake of linoleic acid (LA) increased etheno-DNA adducts induced by lipid peroxidation (LPO) in white blood cells (WBC) of female but not of male volunteers [J. Nair, C.E. Vaca, I. Velic, M. Mutanen, L.M. Valsta, H. Bartsch, High dietary ω-6 polyunsaturated fatty acids drastically increase the formation of etheno-DNA adducts in white blood cells of female subjects, Cancer Epidemiol. Biomarkers Prev. 6 (1997) 597-601]. Etheno-adducts were measured in rats gavaged with LA, oleic acid (OA) and saturated fatty acid rich coconut oil for 30 days. DNA from organs and total WBC was analyzed for 1, N6-ethenodeoxyadenosine (εdA) and 3, N4-ethenodeoxycytidine (εdC) by immunoaffinity/32P-postlabeling. Colon was the most affected target with LA-treatment, where etheno-adducts were significantly elevated in both sexes. In WBC both adducts were elevated only in LA-treated females. Unexpectedly, OA treatment enhanced etheno-adduct levels in prostate 3-9 fold. Our results in rodents confirm the gender-specific increase of etheno-adducts in WBC-DNA, likely due to LPO induced by redox-cycling of 4-hydroxyestradiol. Colon was a target for LPO-derived DNA-adducts in both LA-treated male and female rats, supporting their role in ω-6 PUFA induced colon carcinogenesis
20. Measurement of DNA repair in Chinese hamster fibroblasts employing flow cytometry and monoclonal antibodies to DNA adducts
International Nuclear Information System (INIS)
The authors examined the utility of measuring DNA repair in single cells employing flow cytometric quantitation of fluorescent monoclonal antibodies directed against specific DNA adducts. Two antibodies were employed; the first directed against single strand (ss) bromodeoxyuridine (anti-BrdUrd) and the second against UV light induced ss-thymine dimers (anti-TT). Sensitivity with both monoclonals was highly dependent on DNA denaturation, with the most effective shown to be a 0.5N HCl histone extraction followed by 50% formamide for 30 min at 800C. Unscheduled synthesis following 30 J/m/sup 2/ UV irradiation in Gl/GO plateau phase CHO cells was demonstrated employing the anti-BrdUrd AB method combined with DNA counter-staining with propidium iodide. Data suggest that anti-BrdUrd Ab recognition of newly replicated sequences following UV irradiation may be strongly dependent on chromatin conformation. A linear correlation was observed for mean anti-TT AB fluorescence and UV dose up to a total of 3000 J/m/sup 2/. Also, a rapid reduction in cellular fluorescence, presumably reflecting dimer excision was observed when the cells were returned to 370C before fixation. Finally, data from various repair deficient CHO cells will be compared employing these methods
1. Structure of cis-[Pt(NH3)(2-picoline)]2+ and DNA adduct and its bonding characteristics
Institute of Scientific and Technical Information of China (English)
JIA; Muxin; LIU; Kai; YANG; Zuoyin; CHEN; Guangju
2004-01-01
Several methods including molecular mechanics, molecular dynamics, ONIOM that combines quantum chemistry with molecular mechanics and standard quantum chemistry are used to study the configuration and electron structures of an adduct of the DNA segment d(ATACATG*G*TACATA)·d(TATGTACCATGTAT) with cis-[Pt(NH3)(2-Picoline)]2+. The investigation shows that the configuration optimized by ONIOM is similar to that determined by NMR. Strong chemical bonds between Pt of the complex and two N7s of neighboring guanines in the DNA duplex and hydrogen bond between the NH3 of the complex and O6 of a nearby guanine have a large impact on the configuration of the adduct. Chemical bonds, the aforementioned hydrogen bond, and the interaction between a methyl of the complex and a methyl of the base in close proximity are critical for the complex to specifically recognize DNA.
2. DIFFERENCES IN DETECTION OF DNA ADDUCTS IN THE 32P-POSTLABELING ASSAY AFTER EITHER 1-BUTANOL EXTRACTION OR NUCLEASE P1 TREATMENT
Science.gov (United States)
The use of nuclease Pl treatment and 1-butanol extraction to increase the sensitivity of the 32P-postlabe1ling assay for DNA adducts have been compared. lthough similar results were obtained with the two methods for standard adducts formed with benzo(a)pyrene diol epoxide I, nucl...
3. Arsenic-Induced Antioxidant Depletion, Oxidative DNA Breakage, and Tissue Damages are Prevented by the Combined Action of Folate and Vitamin B12.
Science.gov (United States)
Acharyya, Nirmallya; Deb, Bimal; Chattopadhyay, Sandip; Maiti, Smarajit
2015-11-01
Arsenic is a grade I human carcinogen. It acts by disrupting one-carbon (1C) metabolism and cellular methyl (-CH3) pool. The -CH3 group helps in arsenic disposition and detoxification of the biological systems. Vitamin B12 and folate, the key promoters of 1C metabolism were tested recently (daily 0.07 and 4.0 μg, respectively/100 g b.w. of rat for 28 days) to evaluate their combined efficacy in the protection from mutagenic DNA-breakage and tissue damages. The selected tissues like intestine (first-pass site), liver (major xenobiotic metabolizer) and lung (major arsenic accumulator) were collected from arsenic-ingested (0.6 ppm/same schedule) female rats. The hemo-toxicity and liver and kidney functions were monitored. Our earlier studies on arsenic-exposed humans can correlate carcinogenesis with DNA damage. Here, we demonstrate that the supplementation of physiological/therapeutic dose of vitamin B12 and folate protected the rodents significantly from arsenic-induced DNA damage (DNA fragmentation and comet assay) and hepatic and renal tissue degeneration (histo-architecture, HE staining). The level of arsenic-induced free-radical products (TBARS and conjugated diene) was significantly declined by the restored actions of several antioxidants viz. urate, thiol, catalase, xanthine oxidase, lactoperoxidase, and superoxide dismutase in the tissues of vitamin-supplemented group. The alkaline phosphatase, transaminases, urea and creatinine (hepatic and kidney toxicity marker), and lactate dehydrogenase (tissue degeneration marker) were significantly impaired in the arsenic-fed group. But a significant protection was evident in the vitamin-supplemented group. In conclusion, the combined action of folate and B12 results in the restitution in the 1C metabolic pathway and cellular methyl pool. The cumulative outcome from the enhanced arsenic methylation and antioxidative capacity was protective against arsenic induced mutagenic DNA breakages and tissue damages.
4. DNA adducts, benzo(a)pyrene monooxygenase activity, and lysosomal membrane stability in Mytilus galloprovincialis from different areas in Taranto coastal waters (Italy)
International Nuclear Information System (INIS)
The aim of this study was to investigate the impact of environmental pollution at different stations along the Taranto coastline (Ionian Sea, Puglia, Italy) using several biomarkers of exposure and the effect on mussels, Mytilus galloprovincialis, collected in October 2001 and October 2002. Five sampling sites were compared with a 'cleaner' reference site in the Aeronautics Area. In this study we also investigated the differences between adduct levels in gills and digestive gland. This Taranto area is the most significant industrial settlement on the Ionian Sea known to be contaminated by polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, heavy metals, etc. Exposure to PAHs was evaluated by measuring DNA adduct levels and benzo(a)pyrene monooxygenase activity (B(a)PMO); DNA adducts were analyzed by 32P-postlabeling with nuclease P1 enhancement in both gills and digestive glands to evaluate differences between DNA adduct levels in the two tissues. B(a)PMO was assayed in the microsomal fraction of the digestive glands as a result of the high expression of P450-metabolizing enzymes in this tissue. Lysosomal membrane stability, a potential biomarker of anthropogenic stress, was also evaluated in the digestive glands of mussels, by measuring the latent activity of β-N-acetylhexosaminidase. Induction of DNA adducts was evident in both tissues, although the results revealed large tissue differences in DNA adduct formation. In fact, gills showed higher DNA adduct levels than did digestive gland. No significant differences were found in DNA adduct levels over time, with both tissues providing similar results in both years. DNA adduct levels were correlated with B(a)PMO activity in digestive gland in both years (r=0.60 in 2001; r=0.73 in 2002). Increases were observed in B(a)PMO activity and DNA adduct levels at different stations; no statistical difference was observed in B(a)PMO activity over the two monitoring campaigns. The membrane labilization period
5. Noncovalent interactions of a benzo[a]pyrene diol epoxide with DNA base pairs: insight into the formation of adducts of (+)-BaP DE-2 with DNA.
Science.gov (United States)
Hargis, Jacqueline C; Schaefer, Henry F; Houk, K N; Wheeler, Steven E
2010-02-01
6. Malabaricone C-containing mace extract inhibits safrole bioactivation and DNA adduct formation both in vitro and in vivo.
Science.gov (United States)
Martati, Erryana; Boonpawa, Rungnapa; van den Berg, Johannes H J; Paini, Alicia; Spenkelink, Albertus; Punt, Ans; Vervoort, Jacques; van Bladeren, Peter J; Rietjens, Ivonne M C M
2014-04-01
Safrole, present in mace and its essential oils, causes liver tumors in rodents at high dose levels due to formation of a DNA reactive 1'-sulfooxysafrole. The present study identifies malabaricone C as a mace constituent able to inhibit safrole DNA adduct formation at the level of sulfotransferase mediated bioactivation. This inhibition was incorporated into physiologically based biokinetic rat and human models. Dosing safrole at 50mg/kg body weight and malabaricone C-containing mace extract at a ratio reflecting the relative presence in mace, and assuming 100% or 1% uptake of malabaricone C-containing mace extract, the model predicted inhibition of 1'-sulfooxysafrole formation for rats and humans by 90% and 100% or 61% and 91%, respectively. To validate the model, mace extract and safrole were co-administered orally to Sprague-Dawley rats. LC-ECI-MS/MS based quantification of DNA adduct levels revealed a significant (psafrole DNA adduct formation by malabaricone C-containing mace extract in the liver of rats exposed to safrole. The data obtained were used to perform a refined risk assessment of safrole. Overall, the results suggest a lower tumor incidence when safrole would be tested within a relevant food matrix containing sulfotransferase inhibitors compared to dosing pure safrole.
7. DNA adduct formation and oxidative stress in colon and liver of Big Blue rats after dietary exposure to diesel particles
DEFF Research Database (Denmark)
Dybdahl, Marianne; Risom, Lotte; Møller, Peter;
2003-01-01
Exposure to diesel exhaust particles (DEP) via the gastrointestinal route may impose risk of cancer in the colon and liver. We investigated the effects of DEP given in the diet to Big Blue rats by quantifying a panel of markers of DNA damage and repair, mutation, oxidative damage to proteins...... in liver accompanied by enhanced vitamin C levels. In plasma, we found no significant effects on oxidative damage to proteins and lipids, antioxidant enzymes or vitamin C levels. Our data indicate that gastrointestinal exposure to DEP induces DNA adducts and oxidative stress resulting in DNA strand breaks...
8. Differences in detection of DNA adducts in the 32P-postlabelling assay after either 1-butanol extraction or nuclease P1 treatment.
Science.gov (United States)
Gallagher, J E; Jackson, M A; George, M H; Lewtas, J; Robertson, I G
1989-04-01
The use of nuclease P1 treatment and 1-butanol extraction to increase the sensitivity of the 32P-postlabelling assay for DNA adducts have been compared. Although similar results were obtained with the two methods for standard adducts formed with benzo[a]pyrene diol epoxide I (BPDE-I), nuclease P1 treatment resulted in a significant reduction in detection of major adducts from 1-amino-6-nitropyrene (1-amino-6-NP), 1-amino-8-nitropyrene (1-amino-8-NP), 2-aminofluorene (2-AF), 2-naphthylamine (2-NA) and 4-aminobiphenyl (4-ABP) modified DNAs, but not following the 32P-postlabelling analysis of 2-acetylaminofluorene (2-AAF) modified DNA. These results suggest that, at least initially, both modifications of the 32P-postlabelling assay should be used for the detection of unknown adducts or for adducts derived from nitroaromatics and aromatic amines. PMID:2540901
9. Differences in detection of DNA adducts in the 32P-postlabelling assay after either 1-butanol extraction or nuclease Pl treatment
International Nuclear Information System (INIS)
The use of nuclease P1 treatment and 1-butanol extraction to increase the sensitivity of the 32P-postlabelling assay for DNA adducts have been compared. Although similar results were obtained with the two methods for standard adducts formed with benzo(a)pyrene diol epoxide I, nuclease P1 treatment resulted in a significant reduction in detection of major adducts 1-amino-6-nitropyrene, 1-amino-8-nitropyrene, 2-aminofluorene, 2-naphthylamine and 4-aminobiphenyl modified DNAs, but not following the 32P-postlabelling analysis of 2-acetylaminofluorene modified DNA. These results suggest that at least initially, both modications of the 32P-postlabelling assay should be used for the detection of unknown adducts or for adducts derived from nitro-aromatics and aromatic amines
10. Investigation of the DNA adducts formed in B6C3F1 mice treated with benzene: Implications for molecular dosimetry
Energy Technology Data Exchange (ETDEWEB)
Bodell, W.J.; Pathak, D.N.; Levay, G. [Univ. of California, San Francisco, CA (United States)] [and others
1996-12-01
11. SEPARATION AND CHARACTERIZATION OF TETROL METABOLITES OF BENZO[A]PYRENE-DNA ADDUCTS USING HPLC AND SOLID-MATRIX ROOM TEMPERATURE LUMINESCENCE. (R824100)
Science.gov (United States)
AbstractFour tetrols of benzo[a]pyrene-DNA adducts were separated using reversed-phase high performance liquid chromatography. Chromatographic fractions containing a given tetrol were readily characterized with solid-matrix room temperature luminescence techniques. So...
12. Induction of somatic mutations but not methylated DNA adducts in λlacZ transgenic mice by dichlorvos
NARCIS (Netherlands)
Pletsa, V.; Steenwinkel, M.-J.S.T.; Delft, J.H.M. van; Baan, R.A.; Kyrtopoulos, S.A.
1999-01-01
In order to examine the in vivo genotoxic activity of dichlorvos, λlacZ transgenic mice (Muta(TM)Mouse) were treated i.p. with single (4.4 or 11 mg/kg) or multiple (5x11 mg/kg) doses of this agent and sacrificed 4 h or 14 days post-treatment for DNA adduct measurement or mutant frequency analysis, r
13. Bulky DNA Adducts in Cord Blood, Maternal Fruit-and-Vegetable Consumption, and Birth Weight in a European Mother–Child Study (NewGeneris)
OpenAIRE
Pedersen, Marie; Schoket, Bernadette; Godschalk, Roger W.; Wright, John; von Stedingk, Hans; Törnqvist, Margareta; Sunyer, Jordi; Nielsen, Jeanette K.; Merlo, Domenico Franco; Mendez, Michelle A.; Meltzer, Helle Margrete; Lukacs, Viktoria; Landström, Anette; Kyrtopoulos, Soterios A; Kovacs, Katalin
2013-01-01
Background: Tobacco-smoke, airborne, and dietary exposures to polycyclic aromatic hydrocarbons (PAHs) have been associated with reduced prenatal growth. Evidence from biomarker-based studies of low-exposed populations is limited. Bulky DNA adducts in cord blood reflect the prenatal effective dose to several genotoxic agents including PAHs. Objectives: We estimated the association between bulky DNA adduct levels and birth weight in a multicenter study and examined modification of this associat...
14. 32P-post-labelling analysis of DNA adducts formed in the upper gastrointestinal tissue of mice fed bracken extract or bracken spores.
OpenAIRE
A. C. Povey; D. Potter; O'Connor, P J
1996-01-01
Bracken toxicity to both domestic and laboratory animals is well established and tumours are formed when rodents are treated with either bracken extracts or bracken spores. In this study we have administered bracken spores and extract to mice in order to investigate whether such exposure leads to the formation of DNA adducts. DNA, isolated from the upper gastrointestinal tract and liver, was digested to 3'-nucleotides. Adducts were extracted with butanol, 32P-post-labelled, separated by thin ...
15. Dynamics and mechanism of UV-damaged DNA repair in indole-thymine dimer adduct: molecular origin of low repair quantum efficiency.
Science.gov (United States)
Guo, Xunmin; Liu, Zheyun; Song, Qinhua; Wang, Lijuan; Zhong, Dongping
2015-02-26
Many biomimetic chemical systems for repair of UV-damaged DNA showed very low repair efficiency, and the molecular origin is still unknown. Here, we report our systematic characterization of the repair dynamics of a model compound of indole-thymine dimer adduct in three solvents with different polarity. By resolving all elementary steps including three electron-transfer processes and two bond-breaking and bond-formation dynamics with femtosecond resolution, we observed the slow electron injection in 580 ps in water, 4 ns in acetonitrile, and 1.38 ns in dioxane, the fast back electron transfer without repair in 120, 150, and 180 ps, and the slow bond splitting in 550 ps, 1.9 ns, and 4.5 ns, respectively. The dimer bond cleavage is clearly accelerated by the solvent polarity. By comparing with the biological repair machine photolyase with a slow back electron transfer (2.4 ns) and a fast bond cleavage (90 ps), the low repair efficiency in the biomimetic system is mainly determined by the fast back electron transfer and slow bond breakage. We also found that the model system exists in a dynamic heterogeneous C-clamped conformation, leading to a stretched dynamic behavior. In water, we even identified another stacked form with ultrafast cyclic electron transfer, significantly reducing the repair efficiency. Thus, the comparison of the repair efficiency in different solvents is complicated and should be cautious, and only the dynamics by resolving all elementary steps can finally determine the total repair efficiency. Finally, we use the Marcus electron-transfer theory to analyze all electron-transfer reactions and rationalize all observed electron-transfer dynamics.
16. Typical signature of DNA damage in white blood cells: a pilot study on etheno adducts in Danish mother-newborn child pairs
DEFF Research Database (Denmark)
Arab, K; Pedersen, Marie; Nair, J;
2009-01-01
The impact of DNA damage commonly thought to be involved in chronic degenerative disease causation is particularly detrimental during fetal development. Within a multicenter study, we analyzed 77 white blood cell (WBC) samples from mother-newborn child pairs to see if imprinting of DNA damage...... in mother and newborn shows a similar pattern. Two adducts 1,N(6)-ethenodeoxyadenosine (epsilondA) and 3,N(4)-ethenodeoxycytidine (epsilondC) were measured by our ultrasensitive immunoaffinity (32)P-post-labeling method. These miscoding etheno-DNA adducts are generated by the reaction of lipid peroxidation...... (LPO) end products such as 4-hydroxy-2-nonenal with DNA bases. Mean epsilondA and epsilondC levels when expressed per 10(9) parent nucleotides in WBC-DNA from cord blood were 138 and 354, respectively; in maternal WBC-DNA, the respective values were 317 and 916. Thus, the DNA-etheno adduct levels were...
17. SYNTHESIS OF THE FULLY PROTECTED PHOSPHORAMIDITE OF THE BENZENE-DNA ADDUCT, N2- (4-HYDROXYPHENYL)-2'-DEOXYGUANOSINE AND INCORPORATION OF THE LATER INTO DNA OLIGOMERS
Energy Technology Data Exchange (ETDEWEB)
Chenna, Ahmed; Gupta, Ramesh C.; Bonala, Radha R.; Johnson, Francis; Huang, Bo
2008-06-09
N2-(4-Hydroxyphenyl)-2'-deoxyguanosine-5'-O-DMT-3'-phosphoramidite has been synthesized and used to incorporate the N2-(4-hydroxyphenyl)-2'-dG (N2-4-HOPh-dG) into DNA, using solid-state synthesis technology. The key step to obtaining the xenonucleoside is a palladium (Xantphos-chelated) catalyzed N2-arylation (Buchwald-Hartwig reaction) of a fully protected 2'-deoxyguanosine derivative by 4-isobutyryloxybromobenzene. The reaction proceeded in good yield and the adduct was converted to the required 5'-O-DMT-3'-O-phosphoramidite by standard methods. The latter was used to synthesize oligodeoxynucleotides in which the N2-4-HOPh-dG adduct was incorporated site-specifically. The oligomers were purified by reverse-phase HPLC. Enzymatic hydrolysis and HPLC analysis confirmed the presence of this adduct in the oligomers.
18. Miscoding properties of 1,N{sup 6}-ethanoadenine, a DNA adduct derived from reaction with antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea
Energy Technology Data Exchange (ETDEWEB)
Hang, Bo; Guliaev, Anton B.; Chenna, Ahmed; Singer, B.
2003-03-05
19. Evaluation of Interindividual Human Variation in Bioactivation and DNA Adduct Formation of Estragole in Liver Predicted by Physiologically Based Kinetic/Dynamic and Monte Carlo Modeling.
Science.gov (United States)
Punt, Ans; Paini, Alicia; Spenkelink, Albertus; Scholz, Gabriele; Schilter, Benoit; van Bladeren, Peter J; Rietjens, Ivonne M C M
2016-04-18
20. DNA adduct formation by 2-amino-3-methylimidazo [4,5-f] quinoline (IQ) in rat colon
OpenAIRE
Lin, Chun-xing; Mondan, Yasumasa; Umemoto, Atsushi
2001-01-01
A food-born carcinogen, 2-amino-3-methylimidazo [4,5-f] quinoline (IQ) induces cancer in the rat colon. The mechanism for colonic DNA adduct formation leading to cancer by IQ was studied using a colostomized F344 rat model. In this model, the transverse colon of the rat was colostomized, which produced a fecal stream-positive proximal colon and a negative distal colon were produced. When IQ (50 mg/kg) was administered into the distal colon of the colostomized rats (n=5), the ratio of the DNA ...
1. NMR solution structures of adducts derived from the binding of polycyclic aromatic diol epoxides to DNA
Energy Technology Data Exchange (ETDEWEB)
Cosman, M.; Patel, D.J. [Memorial Sloan Kettering Cancer Center, New York, NY (United States). Cellular Biochemistry and Biophysics Program; Hingerty, B.E. [Oak Ridge National Lab., TN (United States). Health and Safety Research Div.; Amin, S. [American Health Foundation, Valhalla, NY (United States); Broyde, S.; Geacintov, N.E. [New York Univ., NY (United States)
1995-12-31
Site-specifically modified oligonucleotides were derived from the reactions of stereoisomeric polycyclic aromatic diol epoxide metabolite model compounds with oligonucleotides of defined base composition and sequence. The NMR solution structures of ten different adducts studied so far are briefly described, and it is shown that stereochemical factors and the nature of the oligonucleotide context of the complementary strands, exert a powerful influence on the conformational features of these adducts.
2. Structural Basis for Bulky-Adduct DNA-Lesion Recognition by the Nucleotide Excision Repair Protein Rad14.
Science.gov (United States)
Simon, Nina; Ebert, Charlotte; Schneider, Sabine
2016-07-25
Heterocyclic aromatic amines react with purine bases and result in bulky DNA adducts that cause mutations. Such structurally diverse lesions are substrates for the nucleotide excision repair (NER). It is thought that the NER machinery recognises and verifies distorted DNA conformations, also involving the xeroderma pigmentosum group A and C proteins (XPA, XPC) that act as a scaffold between the DNA substrate and several other NER proteins. Here we present the synthesis of DNA molecules containing the polycyclic, aromatic amine C8-guanine lesions acetylaminophenyl, acetylaminonaphthyl, acetylaminoanthryl, and acetylaminopyrenyl, as well as their crystal structures in complex with the yeast XPA homologue Rad14. This work further substantiates the indirect lesion-detection mechanism employed by the NER system that recognises destabilised and deformable DNA structures. PMID:27223336
3. The validity of sedimentation data from high molecular weight DNA and the effects of additives on radiation-induced single-strand breakage
International Nuclear Information System (INIS)
The optimization of many of the factors governing reproducible sedimentation behaviour of high molecular weight single-strand DNA in a particular alkaline sucrose density gradient system is described. A range of angular momenta is defined for which a constant strand breakage efficiency is required, despite a rotor speed effect which increases the measured molecular weights at decreasing rotor speeds for larger DNA molecules. The possibility is discussed that the bimodal control DNA profiles obtained after sedimentation at 11 500 rev/min (12 400 g) or less represent structural subunits of the chromatid. The random induction of single-strand DNA breaks by ionizing radiation is demonstrated by the computer-derived fits to the experimental profiles. The enhancement of single-strand break (SSB) yields in hypoxic cells by oxygen, para-nitroacetophenone (PNAP), or any of the three nitrofuran derivatives used was well correlated with increased cell killing. Furthermore, reductions in SSB yields for known hydroxyl radical (OH.) scavengers correlates with the reactivities of these compounds toward OH.. This supports the contention that some type of OH.-induced initial lesion, which may ultimately be expressed as an unrepaired or misrepaired double-strand break, constitutes a lethal event. (author)
4. Biomarkers of exposure to tobacco smoke and environmental pollutants in mothers and their transplacental transfer to the foetus. Part I: Bulky DNA adducts
International Nuclear Information System (INIS)
32P-postlabelling and PAH-ELISA using the antiserum no. 29 were employed to analyze DNA adducts in venous and umbilical cord blood and the placenta of 79 mothers giving birth to 80 living babies in Prague (Czech Republic). Ambient air exposure was measured by stationary measurements of basic air pollutants (PM2.5, c-PAHs) during the entire pregnancy. Tobacco smoke exposure was assessed by questionnaire data and by plasma cotinine levels. The total DNA adduct levels in the lymphocytes of mothers and newborns were elevated by 30-40% (p 8 nucleotides vs. 0.15 ± 0.06 adducts/108 nucleotides) with newborns indicated a 30-40% increase of adducts in mothers. Almost equal PAH-DNA adduct levels were detected by anti-BPDE-DNA ELISA in the placenta of tobacco smoke-exposed and -unexposed mothers. Our results suggest a protective effect of the placental barrier against the genotoxic effect of some tobacco smoke components between the circulation of mother and child. We found a correlation between adduct levels in the blood of mothers and newborns.
5. Increased micronuclei and bulky DNA adducts in cord blood after maternal exposures to traffic-related air pollution
DEFF Research Database (Denmark)
Pedersen, M.; Wichmann, J.; Autrup, H.;
2009-01-01
Exposure to traffic-related air pollution in urban environment is common and has been associated with adverse human health effects. In utero exposures that result in DNA damage may affect health later in life. Early effects of maternal and in utero exposures to traffic-related air pollution were...... highest among mother-newborn pairs who lived near medium-traffic-density (> 400-2500 vehicle km/24 h; p 2500 vehicle km/24 h) were significantly increased (p = 0.02). This trend remained after adjusting...... for potential confounders and effect modifiers. For the first time increased bulky DNA adducts and MN in cord blood after maternal exposures to traffic-related air pollution are found, demonstrating that these transplacental environmental exposures induce DNA damage in newborns. Given that increased DNA damage...
6. Tamoxifen Forms DNA Adducts In Human Colon After Administration Of A Single [14C]-Labeled Therapeutic Dose.
Energy Technology Data Exchange (ETDEWEB)
Brown, K; Tompkins, E M; Boocock, D J; Martin, E A; Farmer, P B; Turteltaub, K W; Ubick, E; Hemingway, D; Horner-Glister, E; White, I H
2007-05-23
Tamoxifen is widely prescribed for the treatment of breast cancer and is also licensed in the U.S. for the prevention of this disease. However, tamoxifen therapy is associated with an increased occurrence of endometrial cancer in women and there is also evidence that it may elevate the risk of colorectal cancer. The underlying mechanisms responsible for tamoxifen-induced carcinogenesis in women have not yet been elucidated but much interest has focussed on the role of DNA adduct formation. We investigated the propensity of tamoxifen to bind irreversibly to colorectal DNA when given to ten women as a single [{sup 14}C]-labeled therapeutic (20 mg) dose, {approx}18 h prior to undergoing colon resections. Using the sensitive technique of accelerator mass spectrometry, coupled with HPLC separation of enzymatically digested DNA, a peak corresponding to authentic dG-N{sup 2}-tamoxifen adduct was detected in samples from three patients, at levels ranging from 1-7 adducts/10{sup 9} nucleotides. No [{sup 14}C]-radiolabel associated with tamoxifen or its major metabolites was detected. The presence of detectable CYP3A4 protein in all colon samples suggests this tissue has the potential to activate tamoxifen to {alpha}-hydroxytamoxifen, in addition to that occurring in the systemic circulation, and direct interaction of this metabolite with DNA could account for the binding observed. Although the level of tamoxifeninduced damage displayed a degree of inter-individual variability, when present it was {approx}10-100 times higher than that reported for other suspect human colon carcinogens such as PhIP. These findings provide a mechanistic basis through which tamoxifen could increase the incidence of colon cancers in women.
7. Punicalagin and Ellagic Acid Demonstrate Antimutagenic Activity and Inhibition of Benzo[a]pyrene Induced DNA Adducts
Directory of Open Access Journals (Sweden)
Maryam Zahin
2014-01-01
Full Text Available Punicalagin (PC is an ellagitannin found in the fruit peel of Punica granatum. We have demonstrated antioxidant and antigenotoxic properties of Punica granatum and showed that PC and ellagic acid (EA are its major constituents. In this study, we demonstrate the antimutagenic potential, inhibition of BP-induced DNA damage, and antiproliferative activity of PC and EA. Incubation of BP with rat liver microsomes, appropriate cofactors, and DNA in the presence of vehicle or PC and EA showed significant inhibition of the resultant DNA adducts, with essentially complete inhibition (97% at 40 μM by PC and 77% inhibition by EA. Antimutagenicity was tested by Ames test. PC and EA dose-dependently and markedly antagonized the effect of tested mutagens, sodium azide, methyl methanesulfonate, benzo[a]pyrene, and 2-aminoflourine, with maximum inhibition of mutagenicity up to 90 percent. Almost all the doses tested (50–500 μM exhibited significant antimutagenicity. A profound antiproliferative effect on human lung cancer cells was also shown with PC and EA. Together, our data show that PC and EA are pomegranate bioactives responsible for inhibition of BP-induced DNA adducts and strong antimutagenic, antiproliferative activities. However, these compounds are to be evaluated in suitable animal model to assess their therapeutic efficacy against cancer.
8. Dose-dependent reduction of 3,2'-dimethyl-4-aminobiphenyl-derived DNA adducts in colon and liver of rats administered celecoxib
International Nuclear Information System (INIS)
9. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes
International Nuclear Information System (INIS)
10. An integrated QSAR-PBK/D modelling approach for predicting detoxification and DNA adduct formation of 18 acyclic food-borne α,β-unsaturated aldehydes
Energy Technology Data Exchange (ETDEWEB)
Kiwamoto, R., E-mail: reiko.kiwamoto@wur.nl; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.
2015-01-01
11. The role of reactive oxygen species (ROS and cytochrome P-450 2E1 in the generation of carcinogenic etheno-DNA adducts
Directory of Open Access Journals (Sweden)
Kirsten Linhart
2014-01-01
Full Text Available Exocyclic etheno-DNA adducts are mutagenic and carcinogenic and are formed by the reaction of lipidperoxidation (LPO products such as 4-hydoxynonenal or malondialdehyde with DNA bases. LPO products are generated either via inflammation driven oxidative stress or via the induction of cytochrome P-450 2E1 (CYP2E1. In the liver CYP2E1 is induced by various compounds including free fatty acids, acetone and ethanol. Increased levels of CYP2E1 and thus, oxidative stress are observed in the liver of patients with non-alcoholic steatohepatitis (NASH as well as in the chronic alcoholic. In addition, chronic ethanol ingestion also increases CYP2E1 in the mucosa of the oesophagus and colon. In all these tissues CYP2E1 correlates significantly with the levels of carcinogenic etheno-DNA adducts. In contrast, in patients with non-alcoholic steatohepatitis (NASH hepatic etheno-DNA adducts do not correlate with CYP2E1 indicating that in NASH etheno-DNA adducts formation is predominately driven by inflammation rather than by CYP2E1 induction. Since etheno-DNA adducts are strong mutagens producing various types of base pair substitution mutations as well as other types of genetic damage, it is strongly believed that they are involved in ethanol mediated carcinogenesis primarily driven by the induction of CYP2E1.
12. Effect of Increased Water Intake on Urinary DNA Adduct Levels and Mutagenicity in Smokers: A Randomized Study
Directory of Open Access Journals (Sweden)
2015-01-01
Full Text Available The association between fluid intake and bladder cancer risk remains controversial. Very little is known about to which extent the amount of water intake influences the action of excreting toxics upon the urinary system. This proof of concept trial investigates the effect of water intake on mutagenesis in smokers, a high risk population for bladder cancer. Methods. Monocentric randomized controlled trial. Inclusion Criteria. Male subjects aged 2045–45 y/o, smokers, and small drinkers (24-hour urinary volume 700 mOsmol/kg. Outcomes. 4-ABP DNA adducts formation in exfoliated bladder cells in 24-hour urine collection and urinary mutagenicity in 24-hour urine. Test Group. Subjects consumed 1.5 L daily of the study product (EVIAN on top of their usual water intake for 50 days. Control Group. Subjects continued their usual lifestyle habits. Results. 65 subjects were randomized. Mean age was 30 y/o and mean cigarettes per day were 20. A slight decrease in adducts formation was observed between baseline and last visit but no statistically significant difference was demonstrated between the groups. Urinary mutagenicity significantly decreased. The study shows that increasing water intake decreases urinary mutagenicity. It is not confirmed by urinary adducts formation. Further research would be necessary.
13. Effect of Increased Water Intake on Urinary DNA Adduct Levels and Mutagenicity in Smokers: A Randomized Study
Science.gov (United States)
Buendia Jimenez, Inmaculada; Richardot, Pascaline; Picard, Pascaline; Lepicard, Eve M.; De Meo, Michel; Talaska, Glenn
2015-01-01
The association between fluid intake and bladder cancer risk remains controversial. Very little is known about to which extent the amount of water intake influences the action of excreting toxics upon the urinary system. This proof of concept trial investigates the effect of water intake on mutagenesis in smokers, a high risk population for bladder cancer. Methods. Monocentric randomized controlled trial. Inclusion Criteria. Male subjects aged 2045–45 y/o, smokers, and small drinkers (24-hour urinary volume 700 mOsmol/kg). Outcomes. 4-ABP DNA adducts formation in exfoliated bladder cells in 24-hour urine collection and urinary mutagenicity in 24-hour urine. Test Group. Subjects consumed 1.5 L daily of the study product (EVIAN) on top of their usual water intake for 50 days. Control Group. Subjects continued their usual lifestyle habits. Results. 65 subjects were randomized. Mean age was 30 y/o and mean cigarettes per day were 20. A slight decrease in adducts formation was observed between baseline and last visit but no statistically significant difference was demonstrated between the groups. Urinary mutagenicity significantly decreased. The study shows that increasing water intake decreases urinary mutagenicity. It is not confirmed by urinary adducts formation. Further research would be necessary. PMID:26357419
14. Complex relationships between occupation, environment, DNA adducts, genetic polymorphisms and bladder cancer in a case-control study using a structural equation modeling.
Directory of Open Access Journals (Sweden)
Stefano Porru
15. Metabolomic profiling unravels DNA adducts in human breast that are formed from peroxidase mediated activation of estrogens to quinone methides.
Directory of Open Access Journals (Sweden)
16. Detection and quantitation of benzo[a]pyrene-DNA adducts in brain and liver tissues of Beluga whales (Delphinapterus leucas) from the St. Lawrence and Mackenzie Estuaries
International Nuclear Information System (INIS)
It should be noted that there are few analytical techniques available for the detection and quantitation of chemical adducts in the DNA of living organisms. The reasons for this are: the analytical technique often has to accommodate the unique chemical and/or physical properties of the individual chemical or its metabolite; the percentage of total chemical that becomes most of the parent compound is usually detoxified and excreted; not all adducts that form between the genotoxic agent and DNA are stable or are involved in the development of subsequent deleterious events in the organism; and the amount of DNA available for analysis is often quite limited. 16 refs., 1 tab
17. Redox cycling of endogenous copper by ferulic acid leads to cellular DNA breakage and consequent cell death: A putative cancer chemotherapy mechanism.
Science.gov (United States)
Sarwar, Tarique; Zafaryab, Md; Husain, Mohammed Amir; Ishqi, Hassan Mubarak; Rehman, Sayeed Ur; Rizvi, M Moshahid Alam; Tabish, Mohammad
2015-12-01
Ferulic acid (FA) is a plant polyphenol showing diverse therapeutic effects against cancer, diabetes, cardiovascular and neurodegenerative diseases. FA is a known antioxidant at lower concentrations, however at higher concentrations or in the presence of metal ions such as copper, it may act as a pro-oxidant. It has been reported that copper levels are significantly raised in different malignancies. Cancer cells are under increased oxidative stress as compared to normal cells. Certain therapeutic substances like polyphenols can further increase this oxidative stress and kill cancer cells without affecting the proliferation of normal cells. Through various in vitro experiments we have shown that the pro-oxidant properties of FA are enhanced in the presence of copper. Comet assay demonstrated the ability of FA to cause oxidative DNA breakage in human peripheral lymphocytes which was ameliorated by specific copper-chelating agent such as neocuproine and scavengers of ROS. This suggested the mobilization of endogenous copper in ROS generation and consequent DNA damage. These results were further validated through cytotoxicity experiments involving different cell lines. Thus, we conclude that such a pro-oxidant mechanism involving endogenous copper better explains the anticancer activities of FA. This would be an alternate non-enzymatic, and copper-mediated pathway for the cytotoxic activities of FA where it can selectively target cancer cells with elevated levels of copper and ROS.
18. Variation in PAH-related DNA adduct levels among non-smokers: the role of multiple genetic polymorphisms and nucleotide excision repair phenotype.
Science.gov (United States)
Etemadi, Arash; Islami, Farhad; Phillips, David H; Godschalk, Roger; Golozar, Asieh; Kamangar, Farin; Malekshah, Akbar Fazel-Tabar; Pourshams, Akram; Elahi, Seerat; Ghojaghi, Farhad; Strickland, Paul T; Taylor, Philip R; Boffetta, Paolo; Abnet, Christian C; Dawsey, Sanford M; Malekzadeh, Reza; van Schooten, Frederik J
2013-06-15
Polycyclic aromatic hydrocarbons (PAHs) likely play a role in many cancers even in never-smokers. We tried to find a model to explain the relationship between variation in PAH-related DNA adduct levels among people with similar exposures, multiple genetic polymorphisms in genes related to metabolic and repair pathways, and nucleotide excision repair (NER) capacity. In 111 randomly selected female never-smokers from the Golestan Cohort Study in Iran, we evaluated 21 SNPs in 14 genes related to xenobiotic metabolism and 12 SNPs in eight DNA repair genes. NER capacity was evaluated by a modified comet assay, and aromatic DNA adduct levels were measured in blood by32P-postlabeling. Multivariable regression models were compared by Akaike's information criterion (AIC). Aromatic DNA adduct levels ranged between 1.7 and 18.6 per 10(8) nucleotides (mean: 5.8 ± 3.1). DNA adduct level was significantly lower in homozygotes for NAT2 slow alleles and ERCC5 non-risk-allele genotype, and was higher in the MPO homozygote risk-allele genotype. The sum of risk alleles in these genes significantly correlated with the log-adduct level (r = 0.4, p studies, with large inter-individual variation which could best be explained by a combination of Phase I genes and NER capacity. PMID:23175176
19. Evaluation of Interindividual Human Variation in Bioactivation and DNA Adduct Formation of Estragole in Liver Predicted by Physiologically Based Kinetic/Dynamic and Monte Carlo Modeling
NARCIS (Netherlands)
Punt, Ans; Paini, Alicia; Spenkelink, Bert; Scholz, Gabriele; Schilter, Benoit; Bladeren, Van Peter J.; Rietjens, Ivonne M.C.M.
2016-01-01
Estragole is a known hepatocarcinogen in rodents at high doses following metabolic conversion to the DNA-reactive metabolite 1′-sulfooxyestragole. The aim of the present study was to model possible levels of DNA adduct formation in (individual) humans upon exposure to estragole. This was done by
20. Methylation levels of P16 and TP53 that are involved in DNA strand breakage of 16HBE cells treated by hexavalent chromium.
Science.gov (United States)
Hu, Guiping; Li, Ping; Li, Yang; Wang, Tiancheng; Gao, Xin; Zhang, Wenxiao; Jia, Guang
2016-05-13
The correlations between methylation levels of p16 and TP53 with DNA strand breakage treated by hexavalent chromium [Cr(VI)] remain unknown. In this research, Human bronchial epithelial cells (16HBE cells) in vitro and bioinformatics analysis were used to analyze the epigenetic role in DNA damage and potential biomarkers. CCK-8 and single cell gel electrophoresis assay were chosen to detect the cellular biological damage. MALDI-TOF-MS was used to detect the methylation levels of p16 and TP53. qRT-PCR was used to measure their expression levels in different Cr(VI) treatment groups. The transcription factors with target sequences of p16 and TP53 were predicted using various bioinformatics software. The findings showed that the cellular toxicity and DNA strand damage were Cr(VI) concentration dependent. The hypermethylation of CpG1, CpG31 and CpG32 of p16 was observed in Cr(VI) treated groups. There was significant positive correlation between the CpG1 methylation level of p16 and cell damage. In Cr(VI) treated groups, the expression level of p16 was lower than that in control group. The expression level of TP53 increased when the Cr(VI)concentration above 5μM. About p16, there was significant negative correlation between the CpG1 methylation levels with its expression level. A lot of binding sites for transcription factors existed in our focused CpG islands of p16. All the results suggested that the CpG1 methylation level of p16 could be used as a biomarker of epigenetic effect caused by Cr(VI) treatment, which can enhance cell damage by regulating its expression or affecting some transcription factors to combine with their DNA strand sites. PMID:27005777
1. Quantification of DNA adducts formed in liver, lungs, and isolated lung cells of rats and mice exposed to (14)C-styrene by nose-only inhalation.
Science.gov (United States)
Boogaard, P J; de Kloe, K P; Wong, B A; Sumner, S C; Watson, W P; van Sittert, N J
2000-10-01
Bronchiolo-alveolar tumors were observed in mice exposed chronically to 160 ppm styrene, whereas no tumors were seen in rats up to concentrations of 1000 ppm. Clara cells, which are predominant in the bronchiolo-alveolar region in mouse lungs but less numerous in rat and human lung, contain various cytochrome P450s, which may oxidize styrene to the rodent carcinogen styrene-7,8-oxide (SO) and other reactive metabolites. Reactive metabolites may form specific DNA adducts and induce the tumors observed in mice. To determine DNA adducts in specific tissues and cell types, rats and mice were exposed to 160 ppm [ring-U-(14)C]styrene by nose-only inhalation for 6 h in a recirculating exposure system. Liver and lungs were isolated 0 and 42 h after exposure. Fractions enriched in Type II cells and Clara cells were isolated from rat and mouse lung, respectively. DNA adduct profiles differed quantitatively and qualitatively in liver, total lung, and enriched lung cell fractions. At 0 and 42 h after exposure, the two isomeric N:7-guanine adducts of SO (measured together, HPEG) were present in liver at 3.0 +/- 0.2 and 1.9 +/- 0.3 (rat) and 1.2 +/- 0.2 and 3.2 +/- 0.5 (mouse) per 10(8) bases. Several other, unidentified adducts were present at two to three times higher concentrations in mouse, but not in rat liver. In both rat and mouse lung, HPEG was the major adduct at approximately 1 per 10(8) bases at 0 h, and these levels halved at 42 h. In both rat Type II and non-Type II cells, HPEG was the major adduct and was about three times higher in Type II cells than in total lung. For mice, DNA adduct levels in Clara cells and non-Clara cells were similar to total lung. The hepatic covalent binding index (CBI) at 0 and 42 h was 0.19 +/- 0.06 and 0.14 +/- 0.03 (rat) and 0. 25 +/- 0.11 and 0.44 +/- 0.23 (mouse), respectively. The pulmonary CBIs, based on tissues combined for 0 and 42 h, were 0.17 +/- 0.04 (rat) and 0.24 +/- 0.04 (mouse). Compared with CBIs for other genotoxicants
2. In vivo formation of N7-guanine DNA adduct by safrole 2',3'-oxide in mice.
Science.gov (United States)
Shen, Li-Ching; Chiang, Su-Yin; Lin, Ming-Huan; Chung, Wen-Sheng; Wu, Kuen-Yuh
2012-09-18
Safrole, a naturally occurring product derived from spices and herbs, has been shown to be associated with the development of hepatocellular carcinoma in rodents. Safrole 2',3'-oxide (SFO), an electrophilic metabolite of safrole, was shown to react with DNA bases to form detectable DNA adducts in vitro, but not detected in vivo. Therefore, the objective of this study was to investigate the formation of N7-(3-benzo[1,3]dioxol-5-yl-2-hydroxypropyl)guanine (N7γ-SFO-Gua) resulting from the reaction of SFO with the most nucleophilic site of guanine in vitro and in vivo with a newly developed isotope-dilution high performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) method. N7γ-SFO-Gua and [(15)N(5)]-N7-(3-benzo[1,3]dioxol-5-yl-2-hydroxypropyl)guanine ([(15)N(5)]-N7γ-SFO-Gua) were first synthesized, purified, and characterized. The HPLC-ESI-MS/MS method was developed to measure N7γ-SFO-Gua in calf thymus DNA treated with 60 μmol of SFO for 72 h and in urine samples of mice treated with a single dose of SFO (30 mg/kg body weight, intraperitoneally). In calf thymus DNA, the level of N7γ-SFO-Gua was 2670 adducts per 10(6)nucleotides. In urine of SFO-treated mice, the levels of N7γ-SFO-Gua were 1.02±0.14 ng/mg creatinine (n=4) on day 1, 0.73±0.68 ng/mg creatinine (n=4) on day 2, and below the limit of quantitation on day 3. These results suggest that SFO can cause in vivo formation of N7γ-SFO-Gua, which may then be rapidly depurinated from the DNA backbone and excreted through urine.
3. DNA polymerase eta participates in the mutagenic bypass of adducts induced by benzo[a]pyrene diol epoxide in mammalian cells.
Directory of Open Access Journals (Sweden)
Alden C Klarer
Full Text Available Y-family DNA-polymerases have larger active sites that can accommodate bulky DNA adducts allowing them to bypass these lesions during replication. One member, polymerase eta (pol eta, is specialized for the bypass of UV-induced thymidine-thymidine dimers, correctly inserting two adenines. Loss of pol eta function is the molecular basis for xeroderma pigmentosum (XP variant where the accumulation of mutations results in a dramatic increase in UV-induced skin cancers. Less is known about the role of pol eta in the bypass of other DNA adducts. A commonly encountered DNA adduct is that caused by benzo[a]pyrene diol epoxide (BPDE, the ultimate carcinogenic metabolite of the environmental chemical benzo[a]pyrene. Here, treatment of pol eta-deficient fibroblasts from humans and mice with BPDE resulted in a significant decrease in Hprt gene mutations. These studies in mammalian cells support a number of in vitro reports that purified pol eta has error-prone activity on plasmids with site-directed BPDE adducts. Sequencing the Hprt gene from this work shows that the majority of mutations are G>T transversions. These data suggest that pol eta has error-prone activity when bypassing BPDE-adducts. Understanding the basis of environmental carcinogen-derived mutations may enable prevention strategies to reduce such mutations with the intent to reduce the number of environmentally relevant cancers.
4. Reduction of cisplatin-induced nephrotoxicity in vivo by selenomethionine: the effect on cisplatin-DNA adducts.
Science.gov (United States)
García Sar, Daniel; Montes-Bayón, Maria; Blanco González, Elisa; Sierra Zapico, Luisa M; Sanz-Medel, Alfredo
2011-06-20
Cisplatin is one of the most effective chemotherapeutic agents, although its clinical use is limited by severe renal toxicity. This toxicity seems to be related to the accumulation of the drug in kidney tissues, leading to renal failure. For this reason, several compounds have been evaluated to ameliorate the nephrotoxicity induced by cisplatin. In the present investigation, we report the effect of the oral administration of selenomethionine before intraperitoneal cisplatin treatment. The preadministration of this Se species has been shown to have an important effect in reducing renal damage induced by cisplatin by increasing the excreted urea and improving creatinine clearance. Quantification of the level of DNA--cisplatin adducts in kidney and liver tissues was carried out by postcolumn isotope dilution analysis using liquid chromatography-inductively coupled plasma (LC-ICP-MS) as speciation set up. The level of DNA--cisplatin adducts in rats given Se-methionine in the drinking water before cisplatin administration was considerably lower in kidney tissues with respect to the animals drinking only water. Such effects were not observed in liver tissue. Initial speciation studies of Pt and Se conducted in kidney tissues of exposed animals by HPLC-ICP-MS have revealed the presence of cisplatin as part of a complex with Se-methionine, which can be eventually excreted into urine. This Pt--Se complex could explain the observed reduction of the kidney damage in Se-methionine-treated animals. PMID:21491944
5. Dietary and lifestyle determinants of malondialdehyde DNA adducts in a representative sample of the Florence City population.
Science.gov (United States)
Saieva, Calogero; Peluso, Marco; Palli, Domenico; Cellai, Filippo; Ceroti, Marco; Selvi, Valeria; Bendinelli, Benedetta; Assedi, Melania; Munnia, Armelle; Masala, Giovanna
2016-07-01
Malondialdehyde (MDA), a biomarker of lipid peroxidation and oxidative stress, is a mutagenic and carcinogenic compound that can react with DNA to form several types of DNA adducts including the deoxyguanosine adduct (M1dG). The aim of this cross-sectional study was to evaluate the association between individual dietary and lifestyle habits and M1dG levels, measured in peripheral leukocytes in a large representative sample of the general population of Florence City (Italy). Selected anthropometric measurements, detailed information on dietary and lifestyle habits and blood samples were available for 313 adults of the Florence City Sample enrolled in the frame of European Prospective Investigation into Cancer and nutrition (EPIC) study. A multivariate regression analysis adjusted for selected individual characteristics possibly related to M1dG levels (sex, age, BMI, smoke, physical activity level, education level, total caloric intake and a Mediterranean dietary score) was performed to estimate the association between these parameters and M1dG levels. M1dG levels were significantly higher in women (P = 0.014) and lower in moderately active or active subjects (P = 0.037).We also found a significant inverse association with the Modified Mediterranean dietary score (P for trend = 0.049), particularly evident for the highest categories of adherence. Our results indicate that M1dG levels can be modulated by selected individual characteristics such as gender, physical activity and a Mediterranean dietary pattern.
6. DNA breakage, repair and lethality after 125I decay in rec+ and recA strains of Escherichia coli
International Nuclear Information System (INIS)
Iodine-125 decays by electron capture and is known to cause extensive molecular fragmentation via the Auger effect. 125I was incorporated into the DNA of exponentially-growing E. coli K12 AB2487, a recA mutant, and E. coli K12 AB2497, the corresponding rec+ strain as 5-iododeoxyuridine (IUdR), an analogue of thymidine. Radioactive bacteria were stored at -1960C, and samples were periodically assayed for loss of viability and for the induction of double-strand breaks (DSBs) in DNA. Each 125I decay in the DNA of either strain induced one DSB, i.e. proportional to (DSB) = 1.0. For the recA strain, proportional to (lethal) = 0.9 and for the rec+ strain, 0.4. Assays for biological repair of DSBs, involving incubation of thawed samples in growth-medium at 370C before the extraction of DNA, demonstrated significant repair of 125I-induced DSBs by rec+ cells but none by recA cells. For small numbers of decays, there was approximately a 1 : 1 correlation, for either strain, between lethal decays and post-incubation residual DSBs. Comparison with data for larger numbers of decays indicated that a typical rec+ cell can repair no more than three to four DSBs per completed genome (2.5 x 109 daltons). (author)
7. The Protective Effects of N-Acetylcysteine on Exogenous Hydrogen Peroxide and Endogenous Superoxide Anion induced DNA Strand Breakage in Human Spermatozoa%
Institute of Scientific and Technical Information of China (English)
徐德祥; 沈汉民; 王俊南
2001-01-01
Objective To explore the protective effects of N-Acetylcysteine (NAC) on exogenous hydrogen peroxide and endogenous superoxide anion-induced DNA strand breakage in human spermatozoa by using the single-cell gel electropherosis (SCGE)Methods Sperm cells were exposed to 0. 5 mmol/L of H2O2 or 5. 0 mmol/L of β -NADPH with or without 0. 1, 0. 5, 1. 0 mmol/L of NAC. The percentage of sperm comet cells and the comet tail lengths were measured in the treated sperm cells by using SCGE.Results Both percentage of comet sperm nuclei and mean tail length in sperm cells exposed to 0. 5 mmol/L hydrogen peroxide with different concentrations of NAC decrease significantly in a dose-dependent manner as compared with sperm cells exposed to H2O2 without NAC or catalase. Although mean tail length in sperm cells exposed to 5. 0 mmol/L of β-NADPH with different concentrations of NAC decreases significantly compared with sperm cells exposed to β-NADPH without NAC or SOD,there were no significant differences on the percentage of sperm comet cells between sperm cells exposed to 5. 0 mmol/L of β-NADPH with different concentrations of NAC and sperm cells exposed to 5. 0 mmol/L of β-NADPH without NAC.Conclusion NAC has a protective effect on exogenous hydrogen peroxide-induced DNA damage, while protective effect of NAC against O2- induced DNA strand break age is significant but very weak.
8. Nijmegen breakage syndrome (NBS
Directory of Open Access Journals (Sweden)
Chrzanowska Krystyna H
2012-02-01
Full Text Available Abstract Nijmegen breakage syndrome (NBS is a rare autosomal recessive syndrome of chromosomal instability mainly characterized by microcephaly at birth, combined immunodeficiency and predisposition to malignancies. Due to a founder mutation in the underlying NBN gene (c.657_661del5 the disease is encountered most frequently among Slavic populations. The principal clinical manifestations of the syndrome are: microcephaly, present at birth and progressive with age, dysmorphic facial features, mild growth retardation, mild-to-moderate intellectual disability, and, in females, hypergonadotropic hypogonadism. Combined cellular and humoral immunodeficiency with recurrent sinopulmonary infections, a strong predisposition to develop malignancies (predominantly of lymphoid origin and radiosensitivity are other integral manifestations of the syndrome. The NBN gene codes for nibrin which, as part of a DNA repair complex, plays a critical nuclear role wherever double-stranded DNA ends occur, either physiologically or as a result of mutagenic exposure. Laboratory findings include: (1 spontaneous chromosomal breakage in peripheral T lymphocytes with rearrangements preferentially involving chromosomes 7 and 14, (2 sensitivity to ionizing radiation or radiomimetics as demonstrated in vitro by cytogenetic methods or by colony survival assay, (3 radioresistant DNA synthesis, (4 biallelic hypomorphic mutations in the NBN gene, and (5 absence of full-length nibrin protein. Microcephaly and immunodeficiency are common to DNA ligase IV deficiency (LIG4 syndrome and severe combined immunodeficiency with microcephaly, growth retardation, and sensitivity to ionizing radiation due to NHEJ1 deficiency (NHEJ1 syndrome. In fact, NBS was most commonly confused with Fanconi anaemia and LIG4 syndrome. Genetic counselling should inform parents of an affected child of the 25% risk for further children to be affected. Prenatal molecular genetic diagnosis is possible if disease
9. Formation of cyclic 1,N2-propanodeoxyguanosine and thymidine adducts in the reaction of the mutagen 2-bromoacrolein with calf thymus DNA
International Nuclear Information System (INIS)
The interaction of the mutagen 2-bromoacrolein (2BA) with DNA and thymidine was studied in vitro by reaction of [3-3H]2BA with thymidine, RNA, single-stranded DNA, and double-stranded DNA in phosphate buffer (pH 7.4). After purification of the nucleic acids, they were incubated at alkaline pH to convert any (hydroxybromo)propano(deoxy)-guanosine adducts to their dihydroxy analogues. After acid or enzymatic hydrolysis, the hydrolysates were analyzed by reversed-phase high-performance liquid chromatography. At a concentration of 1.6 mM, the fraction of 2BA that became covalently bound to DNA was 2.3% of the amount added. Only 3% of the radioactivity bound to DNA after extensive purification could be accounted for as cyclic 1,N2-(6,7-dihydroxy)-propanoguanine adducts. More 2BA became covalently bound to single-stranded DNA and RNA as compared with double-stranded DNA. However, high-performance liquid chromatographic analyses showed that formation of cyclic 1,N2-(6,7-dihydroxy)propanoguanine adducts was also a minor reaction with these macromolecules. Because these data showed that other type(s) of reaction(s) are more important in the reaction of 2BA with nucleic acids, we have investigated the reaction of 2BA with other nucleosides. It was found that 2BA reacted well with thymidine in vitro, and the major product was identified by 500 MHz 1H and 75.43 MHz 13C nuclear magnetic resonance and thermospray mass spectrometry as 3-(2-bromo-3-oxopropyl)thymidine. This adduct was unstable and decomposed upon storage. After enzymatic hydrolysis of [3H]2BA-modified double-stranded DNA and subsequent analysis of the hydrolysate by high-performance liquid chromatography, 22% of the covalently bound radioactivity to DNA coeluted with decomposition products of the 3-(bromooxypropyl)thymidine adduct
10. Interactive effects of ultraviolet-B radiation and pesticide exposure on DNA photo-adduct accumulation and expression of DNA damage and repair genes in Xenopus laevis embryos
Energy Technology Data Exchange (ETDEWEB)
Yu, Shuangying, E-mail: shuangying.yu@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Tang, Song, E-mail: song.tang@usask.ca [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Mayer, Gregory D., E-mail: greg.mayer@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States); Cobb, George P., E-mail: george_cobb@baylor.edu [Department of Environmental Science, Baylor University, One Bear Place #97266, Waco, TX 76798 (United States); Maul, Jonathan D., E-mail: jonathan.maul@ttu.edu [Department of Environmental Toxicology, The Institute of Environmental and Human Health, Texas Tech University, 1207 S. Gilbert Dr., Lubbock, TX 79416 (United States)
2015-02-15
11. Interactive effects of ultraviolet-B radiation and pesticide exposure on DNA photo-adduct accumulation and expression of DNA damage and repair genes in Xenopus laevis embryos
International Nuclear Information System (INIS)
12. Mutations Induced by Benzo[a]pyrene and Dibenzo[a,l]pyrene in lacI Transgenic B6C3F1 Mouse Lung Result from Stable DNA Adducts
Science.gov (United States)
Dibenzo[a,l]pyrene (DB[a,l]P) and benzo[a]pyrene (B[a]P) are carcinogenic polycyclic aromatic hydrocarbons (PAH) that are each capable of forming a variety of covalent adducts with DNA. Some of the DNA adducts formed by these PAHs have been demonstrated to spontaneously depurina...
13. Multiclass Carcinogenic DNA Adduct Quantification in Formalin-Fixed Paraffin-Embedded Tissues by Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry.
Science.gov (United States)
Guo, Jingshu; Yun, Byeong Hwa; Upadhyaya, Pramod; Yao, Lihua; Krishnamachari, Sesha; Rosenquist, Thomas A; Grollman, Arthur P; Turesky, Robert J
2016-05-01
14. Alcohol, Aldehydes, Adducts and Airways.
Science.gov (United States)
Sapkota, Muna; Wyatt, Todd A
2015-11-05
Drinking alcohol and smoking cigarettes results in the formation of reactive aldehydes in the lung, which are capable of forming adducts with several proteins and DNA. Acetaldehyde and malondialdehyde are the major aldehydes generated in high levels in the lung of subjects with alcohol use disorder who smoke cigarettes. In addition to the above aldehydes, several other aldehydes like 4-hydroxynonenal, formaldehyde and acrolein are also detected in the lung due to exposure to toxic gases, vapors and chemicals. These aldehydes react with nucleophilic targets in cells such as DNA, lipids and proteins to form both stable and unstable adducts. This adduction may disturb cellular functions as well as damage proteins, nucleic acids and lipids. Among several adducts formed in the lung, malondialdehyde DNA (MDA-DNA) adduct and hybrid malondialdehyde-acetaldehyde (MAA) protein adducts have been shown to initiate several pathological conditions in the lung. MDA-DNA adducts are pre-mutagenic in mammalian cells and induce frame shift and base-pair substitution mutations, whereas MAA protein adducts have been shown to induce inflammation and inhibit wound healing. This review provides an insight into different reactive aldehyde adducts and their role in the pathogenesis of lung disease.
15. Effect of increased intake of dietary animal fat and fat energy on oxidative damage, mutation frequency, DNA adduct level and DNA repair in rat colon and liver
DEFF Research Database (Denmark)
Vogel, Ulla; Daneshvar, Bahram; Autrup, Herman;
2003-01-01
The effect of high dietary intake of animal fat and an increased fat energy intake on colon and liver genotoxicity and on markers of oxidative damage and antioxidative defence in colon, liver and plasma was investigated in Big Blue rats. The rats were fed ad libitum with semi-synthetic feed....... The DNA-adduct level measured by 32P-postlabelling decreased in both liver and colon with increased fat intake. In liver, this was accompanied by a 2-fold increase of the mRNA level of nucleotide excision repair (NER) gene ERCC1. In colon, a non-statistically significant increase in the ERCC1 mRNA levels...
16. MeIQx-induced DNA adduct formation and mutagenesis in DNA repair deficient CHO cells expressing human CYP1A1 and rapid or slow acetylator NAT2
Science.gov (United States)
Bendaly, Jean; Zhao, Shuang; Neale, Jason R.; Metry, Kristin J.; Doll, Mark A.; States, J. Christopher; Pierce, William M.; Hein, David W.
2007-01-01
2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MeIQx) is one of the most potent and abundant mutagens in the western diet. Bioactivation includes N-hydroxylation catalyzed by cytochrome P450s followed by O-acetylation catalyzed by N-acetyltransferase 2 (NAT2). Nucleotide excision repair-deficient chinese hamster ovary (CHO) cells were constructed by stable transfection of human cytochrome P4501A1 (CYP1A1) and a single copy of either NAT2*4 (rapid acetylator) or NAT2*5B (slow acetylator) alleles. CYP1A1 and NAT2 catalytic activities were undetectable in untransfected CHO cell lines. CYP1A1 activity did not differ significantly (p > 0.05) among the CYP1A1-transfected cell lines. Cells transfected with NAT2*4 had significantly higher levels of sulfamethazine N-acetyltransferase (p = 0.0001) and N-hydroxy-MeIQx O-acetyltransferase (p = 0.0093) catalytic activity than cells transfected with NAT2*5B. Only cells transfected with both CYP1A1 and NAT2*4 showed concentration-dependent cytotoxicity and hypoxanthine phosphoribosyl transferase (hprt) mutagenesis following MeIQx treatment. dG-C8-MeIQx was the primary DNA adduct formed and levels were dose-dependent in each cell line and in the order: untransfected < transfected with CYP1A1 < transfected with CYP1A1 & NAT2*5B < transfected with CYP1A1 & NAT2*4. MeIQx DNA adduct levels were significantly higher (p < 0.001) in CYP1A1/NAT2*4 than CYP1A1/NAT2*5B cells at all concentrations of MeIQx tested. MeIQx-induced DNA adduct levels correlated very highly (r2 = 0.88) with MeIQx-induced mutants. These results strongly support extrahepatic activation of MeIQx by CYP1A1 and a robust effect of human NAT2 genetic polymorphism on MeIQx –induced DNA adducts and mutagenesis. The results provide laboratory-based support for epidemiological studies reporting higher frequency of heterocyclic amine-related cancers in rapid NAT2 acetylators. PMID:17627018
17. Cadmium affects viability of bone marrow mesenchymal stem cells through membrane impairment, intracellular calcium elevation and DNA breakage
Directory of Open Access Journals (Sweden)
2010-01-01
Full Text Available Background: Cadmium is an important heavy metal with occupational and environmental hazard. Cadmium toxicity results mainly in bone-related complication such as itai-itai disease. Mesenchymal stem cells of the bone marrow have the ability to differentiate to osteoblasts which ensure the well-being of the bone tissue. Thus the aim was to investigate the effect of cadmium on viability of rat bone marrow mesenchymal stem cells. Materials and Methods: The rat bone marrow mesenchymal stem cells were grown to confluency in DMEM medium supplemented with 15% fetal bovine serum and penicillin-streptomycin up to third passage. Then the cells were treated with 0, 5, 15, 25, 35, and 45 of CdCl 2 at 12, 24, 36, and 48 h, and their viability was investigated using trypan blue staining. In addition, after treatment with selected dose (15 and 45 μM and time (24 and 48 h the cell morphology, DNA damage and calcium content of the cells were evaluated. Data was analyzed using one and two-way ANOVA (Tukey test and the P2+ was observed. Conclusion: Cadmium chloride is a toxic compound which might affect the well-being of bone tissue through affecting the mesenchymal stem cells.
18. In vitro bypass of the major malondialdehyde- and base propenal-derived DNA adduct by human Y-family DNA polymerases κ, ι, and Rev1.
Science.gov (United States)
Maddukuri, Leena; Eoff, Robert L; Choi, Jeong-Yun; Rizzo, Carmelo J; Guengerich, F Peter; Marnett, Lawrence J
2010-09-28
3-(2'-Deoxy-β-d-erythro-pentofuranosyl)pyrimido-[1,2-a]purin-10(3H)-one (M(1)dG) is the major adduct derived from the reaction of DNA with the lipid peroxidation product malondialdehyde and the DNA peroxidation product base propenal. M(1)dG is mutagenic in Escherichia coli and mammalian cells, inducing base-pair substitutions (M(1)dG → A and M(1)dG → T) and frameshift mutations. Y-family polymerases may contribute to the mutations induced by M(1)dG in vivo. Previous reports described the bypass of M(1)dG by DNA polymerases η and Dpo4. The present experiments were conducted to evaluate bypass of M(1)dG by the human Y-family DNA polymerases κ, ι, and Rev1. M(1)dG was incorporated into template-primers containing either dC or dT residues 5' to the adduct, and the template-primers were subjected to in vitro replication by the individual DNA polymerases. Steady-state kinetic analysis of single nucleotide incorporation indicates that dCMP is most frequently inserted by hPol κ opposite the adduct in both sequence contexts, followed by dTMP and dGMP. dCMP and dTMP were most frequently inserted by hPol ι, and only dCMP was inserted by Rev1. hPol κ extended template-primers in the order M(1)dG:dC > M(1)dG:dG > M(1)dG:dT ∼ M(1)dG:dA, but neither hPol ι nor Rev1 extended M(1)dG-containing template-primers. Liquid chromatography-mass spectrometry analysis of the products of hPol κ-catalyzed extension verified this preference in the 3'-GXC-5' template sequence but revealed the generation of a series of complex products in which dAMP is incorporated opposite M(1)dG in the 3'-GXT-5' template sequence. The results indicate that DNA hPol κ or the combined action of hPol ι or Rev1 and hPol κ bypass M(1)dG residues in DNA and generate products that are consistent with some of the mutations induced by M(1)dG in mammalian cells. PMID:20726503
19. In Vitro Bypass of the Major Malondialdehyde- and Base Propenal-Derived DNA Adduct by Human Y-family DNA Polymerases κ, ι, and Rev1†
Science.gov (United States)
2010-01-01
3-(2′-Deoxy-β-d-erythro-pentofuranosyl)pyrimido-[1,2-a]purin-10(3H)-one (M1dG) is the major adduct derived from the reaction of DNA with the lipid peroxidation product malondialdehyde and the DNA peroxidation product base propenal. M1dG is mutagenic in Escherichia coli and mammalian cells, inducing base-pair substitutions (M1dG → A and M1dG → T) and frameshift mutations. Y-family polymerases may contribute to the mutations induced by M1dG in vivo. Previous reports described the bypass of M1dG by DNA polymerases η and Dpo4. The present experiments were conducted to evaluate bypass of M1dG by the human Y-family DNA polymerases κ, ι, and Rev1. M1dG was incorporated into template-primers containing either dC or dT residues 5′ to the adduct, and the template-primers were subjected to in vitro replication by the individual DNA polymerases. Steady-state kinetic analysis of single nucleotide incorporation indicates that dCMP is most frequently inserted by hPol κ opposite the adduct in both sequence contexts, followed by dTMP and dGMP. dCMP and dTMP were most frequently inserted by hPol ι, and only dCMP was inserted by Rev1. hPol κ extended template-primers in the order M1dG:dC > M1dG:dG > M1dG:dT ∼ M1dG:dA, but neither hPol ι nor Rev1 extended M1dG-containing template-primers. Liquid chromatography−mass spectrometry analysis of the products of hPol κ-catalyzed extension verified this preference in the 3′-GXC-5′ template sequence but revealed the generation of a series of complex products in which dAMP is incorporated opposite M1dG in the 3′-GXT-5′ template sequence. The results indicate that DNA hPol κ or the combined action of hPol ι or Rev1 and hPol κ bypass M1dG residues in DNA and generate products that are consistent with some of the mutations induced by M1dG in mammalian cells. PMID:20726503
20. Urinary Metabolites of the Dietary Carcinogen PhIP are Predictive of Colon DNA Adducts After a Low Dose Exposure in Humans
Energy Technology Data Exchange (ETDEWEB)
Malfatti, M; Dingley, K; Nowell, S; Ubick, E; Mulakken, N; Nelson, D; Lang, N; Felton, J; Turteltaub, K
2006-04-28
Epidemiologic evidence indicates that exposure to heterocyclic amines (HAs) in the diet is an important risk factor for the development of colon cancer. Well-done cooked meats contain significant levels of HAs which have been shown to cause cancer in laboratory animals. To better understand the mechanisms of HA bioactivation in humans, the most mass abundant HA, 2-amino-l-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), was used to assess the relationship between PhIP metabolism and DNA adduct formation. Ten human volunteers were administered a dietary relevant dose of [{sup 14}C]PhIP 48-72 h prior to surgery to remove colon tumors. Urine was collected for 24 h after dosing for metabolite analysis, and DNA was extracted from colon tissue and analyzed by accelerator mass spectrometry for DNA adducts. All ten subjects were phenotyped for CYP1A2, NAT2, and SULT1A1 enzyme activity. Twelve PhIP metabolites were detected in the urine samples. The most abundant metabolite in all volunteers was N-hydroxy-PhIP-N{sup 2}-glucuronide. Metabolite levels varied significantly between the volunteers. Interindividual differences in colon DNA adducts levels were observed between each individual. The data showed that individuals with a rapid CYP1A2 phenotype and high levels of urinary N-hydroxy-PhIP-N{sup 2}-glucuronide, had the lowest level of colon PhIP-DNA adducts. This suggests that glucuronidation plays a significant role in detoxifying N-hydroxy-PhIP. The levels of urinary N-hydroxy-PhIP-N{sup 2}-glucuronide were negatively correlated to colon DNA adduct levels. Although it is difficult to make definite conclusions from a small data set, the results from this pilot study have encouraged further investigations using a much larger study group.
1. Effects of dietary fish oil on the depletion of carcinogenic PAH-DNA adduct levels in the liver of B6C3F1 mouse.
Directory of Open Access Journals (Sweden)
Guo-Dong Zhou
Full Text Available Many carcinogenic polycyclic aromatic hydrocarbons (PAHs and their metabolites can bind covalently to DNA. Carcinogen-DNA adducts may lead to mutations in critical genes, eventually leading to cancer. In this study we report that fish oil (FO blocks the formation of DNA adducts by detoxification of PAHs. B6C3F1 male mice were fed a FO or corn oil (CO diet for 30 days. The animals were then treated with seven carcinogenic PAHs including benzo(apyrene (BaP with one of two doses via a single intraperitoneal injection. Animals were terminated at 1, 3, or 7 d after treatment. The levels of DNA adducts were analyzed by the (32P-postlabeling assay. Our results showed that the levels of total hepatic DNA adducts were significantly decreased in FO groups compared to CO groups with an exception of low PAH dose at 3 d (P = 0.067. Total adduct levels in the high dose PAH groups were 41.36±6.48 (Mean±SEM and 78.72±8.03 in 10(9 nucleotides (P = 0.011, respectively, for the FO and CO groups at 7 d. Animals treated with the low dose (2.5 fold lower PAHs displayed similar trends. Total adduct levels were 12.21±2.33 in the FO group and 24.07±1.99 in the CO group, P = 0.008. BPDE-dG adduct values at 7 d after treatment of high dose PAHs were 32.34±1.94 (CO group and 21.82±3.37 (FO group in 10(9 nucleotides with P value being 0.035. Low dose groups showed similar trends for BPDE-dG adduct in the two diet groups. FO significantly enhanced gene expression of Cyp1a1 in both the high and low dose PAH groups. Gstt1 at low dose of PAHs showed high levels in FO compared to CO groups with P values being 0.014. Histological observations indicated that FO played a hepatoprotective role during the early stages. Our results suggest that FO has a potential to be developed as a cancer chemopreventive agent.
2. Inhibition of HIV-1 reverse transcriptase-catalyzed synthesis by intercalated DNA Benzo[a]Pyrene 7,8-Dihydrodiol-9,10-Epoxide adducts.
Directory of Open Access Journals (Sweden)
Parvathi Chary
Full Text Available To aid in the characterization of the relationship of structure and function for human immunodeficiency virus type-1 reverse transcriptase (HIV-1 RT, this investigation utilized DNAs containing benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE-modified primers and templates as a probe of the architecture of this complex. BPDE lesions that differed in their stereochemistry around the C10 position were covalently linked to N (6-adenine and positioned in either the primer or template strand of a duplex template-primer. HIV-1 RT exhibited a stereoisomer-specific and strand-specific difference in replication when the BPDE-lesion was placed in the template versus the primer strand. When the C10 R-BPDE adduct was positioned in the primer strand in duplex DNA, 5 nucleotides from the 3΄ end of the primer terminus, HIV-1 RT could not fully replicate the template, producing truncated products; this block to further synthesis did not affect rates of dissociation or DNA binding affinity. Additionally, when the adducts were in the same relative position, but located in the template strand, similar truncated products were observed with both the C10 R and C10 S BPDE adducts. These data suggest that the presence of covalently-linked intercalative DNA adducts distant from the active site can lead to termination of DNA synthesis catalyzed by HIV-1 RT.
3. Lack of contribution of covalent benzo[a]pyrene-7,8-quinone-DNA adducts in benzo[a]pyrene-induced mouse lung tumorigenesis
Science.gov (United States)
Benzo[a]pyrene (B[a]P) is a potent human and rodent lung carcinogen. This activity has been ascribed in part to the formation of anti-trans-B[a]P-7,8-diol-9,10-epoxide (BPDE)-DNA adducts. Other carcinogenic mechanisms have been proposed: 1.] The induction of apurinic sites from r...
4. Red meat enhances the colonic formation of the DNA adduct O6-carboxymethyl guanine: implications for colorectal cancer risk.
Science.gov (United States)
Lewin, Michelle H; Bailey, Nina; Bandaletova, Tanya; Bowman, Richard; Cross, Amanda J; Pollock, Jim; Shuker, David E G; Bingham, Sheila A
2006-02-01
Red meat is associated with increased risk of colorectal cancer and increases the endogenous formation of N-nitrosocompounds (NOC). To investigate the genotoxic effects of NOC arising from red meat consumption, human volunteers were fed high (420 g) red meat, vegetarian, and high red meat, high-fiber diets for 15 days in a randomized crossover design while living in a volunteer suite, where food was carefully controlled and all specimens were collected. In 21 volunteers, there was a consistent and significant (P vegetarian diet as measured by apparent total NOC (ATNC) in feces. In colonic exfoliated cells, the percentage staining positive for the NOC-specific DNA adduct, O(6)-carboxymethyl guanine (O(6)CMG) was significantly (P colorectal cancer. PMID:16452248
5. Evaluation of the metabolic fate of munitions material (TNT & RDX) in plant systems and initial assessment of material interaction with plant genetic material (DNA). Initial assessment of plant DNA adducts as biomarkers
Energy Technology Data Exchange (ETDEWEB)
Harvey, S.D.; Clauss, T.W.; Fellows, R.J.; Cataldo, D.A.
1995-08-01
Genetic damage to deoxyribonucleic acid (DNA) has long been suspected of being a fundamental event leading to cancer. A variety of causal factors can result in DNA damage including photodimerization of base pairs, ionizing radiation, specific reaction of DNA with environmental pollutants, and nonspecific oxidative damage caused by the action of highly reactive oxidizing agents produced by metabolism. Because organisms depend on an unadulterated DNA template for reproduction, DNA repair mechanisms are an important defense for maintaining genomic integrity. The objective of this exploratory project was to evaluate the potential for TNT to form DNA adducts in plants. These adducts, if they exist in sufficient quantities, could be potential biomarkers of munitions exposure. The ultimate goal is to develop a simple analytical assay for the determination of blomarkers that is indicative of munitions contamination. DNA repair exists in dynamic equilibrium with DNA damage. Repair mechanisms are capable of keeping DNA damage at remarkably low concentrations provided that the repair capacity is not overwhelmed.
6. Norbixin ingestion did not induce any detectable DNA breakage in liver and kidney but caused a considerable impairment in plasma glucose levels of rats and mice.
Science.gov (United States)
Fernandes, Ana C.S.; Almeida, Carla A.; Albano, Franco; Laranja, Gustavo A.T.; Felzenszwalb, Israel; Lage, Celso L.S.; de Sa, Cristiano C.N.F.; Moura, Anibal S.; Kovary, Karla
2002-07-01
From the seeds of Bixa orellana are extracted the carotenoids bixin and norbixin that have been widely used for coloring food. In this study, the toxicity of norbixin, purified or not (annatto extract containing 50% norbixin), was investigated in mice and rats after 21 days of ingestion through drinking water. Mice were exposed to doses of 56 and 351 mg/kg (annatto extract) and 0.8, 7.6, 66 and 274 mg/kg (norbixin). Rats were exposed to doses of 0.8, 7.5 and 68 mg/kg (annatto extract) and 0.8, 8.5 and 74 mg/kg (norbixin). In rats, no toxicity was detected by plasma chemistry. In mice, norbixin induced an increase in plasma alanine aminotransferase activity (ALT) while both norbixin and annatto extract induced a decrease in plasma total protein and globulins (P < 0.05). However, no signs of toxicity were detected in liver by histopathological analysis. No enhancement in DNA breakage was detected in liver or kidney from mice treated with annatto pigments, as evaluated by the comet assay. Nevertheless, there was a remarkable effect of norbixin on the glycemia of both rodent species. In rats, norbixin induced hyperglycemia that ranged from 26.9% (8.5 mg/kg norbixin, to 52.6% (74 mg/kg norbixin, P < 0.01) above control levels. In mice, norbixin induced hypoglycemia that ranged from 14.4% (0.8 mg/kg norbixin, P < 0.05) to 21.5% (66 mg/kg norbixin, P < 0.001) below control levels. Rats and mice treated with annatto pigments showed hyperinsulinemia and hypoinsulinemia, respectively indicating that pancreatic beta-cells were functional. More studies should be performed to fully understand of how species-related differences influences the biological fate of norbixin. PMID:12121828
7. Absence of formation of benzo[a]pyrene/DNA adducts in the cuttlefish (Sepia officinalis, Mollusca: Cephalopoda)
Energy Technology Data Exchange (ETDEWEB)
Lee, P.G.; Lu, L.J.W.; Salazar, J.J.; Holoubek, V. (Univ. of Texas Medical Branch, Galveston, TX (United States))
1994-01-01
Benzo[a]pyrene (B[a]P) injected intramuscularly into the base of the arms of cuttlefish was released continuously from the injection site and removed from the organism. Only a portion of the compound accumulated in the body. Twenty-four hr after its injection, 75% of B[a]P applied in olive oil was removed from the cuttlefish, and 1.2% was found in the body outside the head, in site of injection. If the carcinogen was dissolved in dimethylformamide, the removal of B[a]P was slower, so that only 18% of the injected B[a]P was removed from the organism and 0.36% accumulated in the body outside the head 24 hr after injection. The high level of B[a]P in gills and hemolymph 4 hr after injection and the kinetics of the decrease of its concentration with time indicate that these two organs could be involved in the excretion of B[a]P from the body. The B[a]P/DNA adducts characteristic for vertebrates could not be demonstrated in gills, skin, brain, hepatopancreas, and lymphocytes of the cuttlefish 24 hr after injection. The dose of the carcinogene injected into the cuttlefish was 2-4 times higher than the dose resulting in the formation of a high level of B[a]P/DNA adducts in vertebrates. A different metabolism of B[a]P in the tissue of cephalopods, compared to vertebrates, could be less favorable to the process leading to malignant transformation and could explain the absence from the literature of reports of tumors in cephalopods. 15 refs., 1 fig., 2 tabs.
8. Dietary phenolics as anti-mutagens and inhibitors of tobacco-related DNA adduction in the urothelium of smokers.
Science.gov (United States)
Malaveille, C; Hautefeuille, A; Pignatelli, B; Talaska, G; Vineis, P; Bartsch, H
1996-10-01
Human urine is known to contain substances that strongly inhibit bacterial mutagenicity of aromatic and heterocyclic amines in vitro. The biological relevance of these anti-mutagens was examined by comparing levels of tobacco-related DNA adducts in exfoliated urothelial cells from smokers with the anti-mutagenic activity in corresponding 24-h urine samples. An inverse relationship was found between the inhibition of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-mutagenicity by urine extracts in vitro and two DNA adduct measurements: the level of the putatively identified N-(deoxyguanosine-8-yl)-4-aminobiphenyl adduct and the total level of all tobacco-smoke-related carcinogen adducts including those probably derived from PhIP. Urinary anti-mutagenicity in vitro appears thus to be a good indicator of the anti-genotoxicity exerted by substances excreted in urine, that protect the bladder mucosal cells (and possibly other cells) against DNA damage. These substances appear to be dietary phenolics and/or their metabolites because (i) the anti-mutagenic activity of urine extracts (n = 18) was linearly related to their content in phenolics; (ii) the concentration ranges of these substances in urine extracts were similar to those of various plant phenols (quercetin, isorhamnetin and naringenin) for which an inhibitory effect on the liver S9-mediated mutagenicity of PhIP was obtained; (iii) treatment of urines with beta-glucuronidase and arylsulfatase enhanced both anti-mutagenicity and the levels of phenolics in urinary extracts; (iv) urinary extracts inhibited noncompetitively the liver S9-mediated mutagenicity of PhIP as did quercetin, used as a model phenolics. Several structural features of the flavonoids were identified as necessary for the inhibition of PhIP and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxiline mutagenicity. Fractionation by reverse-phase HPLC and subsequent analysis of two urinary extracts, showed the presence of several anti
9. Possible new variant of Nijmegen breakage syndrome
Energy Technology Data Exchange (ETDEWEB)
Der Kaloustian, V.M.; Booth, A.; Elliott, A.M. [Montreal Childrens Hospital and McGill Univ., Montreal (Canada)] [and others
1996-10-02
We report on a child with microcephaly, small facial and body size, and immune deficiency. The phenotype is consistent with Nijmegen breakage syndrome (NBS), with additional clinical manifestations and laboratory findings not reported heretofore. Most investigations, including the results of radiation-resistant DNA synthesis, concurred with the diagnosis of NBS. Cytogenetic analysis documented abnormalities in virtually all cells examined. Along with the high frequency of breaks and rearrangements of chromosomes 7 and 14, we found breakage and monosomies involving numerous other chromosomes. Because of some variation in the clinical presentation and some unusual cytogenetic findings, we suggest that our patient may represent a new variant of Nijmegen breakage syndrome. 34 refs., 3 figs., 7 tabs.
10. Biomarkers for Exposure to Ambient Air Pollution - Comparison of Carcinogen-DNA Adduct Levels with Other Exposure Markers and Markers for Oxidative Stress
DEFF Research Database (Denmark)
Autrup, Herman; Daneshvar, Bahram; Dragsted, Lars Ove;
1999-01-01
Human exposure to genotoxic compounds present in ambient air has been studied using selected biomarkers in nonsmoking Danish bus drivers and postal workers. A large interindividual variation in biomarker levels was observed. Significantly higher levels of bulky carcinogen-DNA adducts (75.42 adducts....../10(8) nucleotides) and of 2-amino-apidic semialdehyde (AAS) in plasma proteins (56.7 pmol/mg protein) were observed in bus drivers working in the central part of Copenhagen, Denmark. In contrast, significantly higher levels of AAS in hemoglobin (55.8 pmol/mg protein), malondialdehyde in plasma (0. 96...... nmol/ml plasma), and polycyclic aromatic hydrocarbon (PAH)-albumin adduct (3.38 fmol/ microg albumin) were observed in the suburban group. The biomarker levels in postal workers were similar to the levels in suburban bus drivers. In the combined group of bus drivers and postal workers, negative...
11. Biomarkers for exposure to ambient air pollution--comparison of carcinogen-DNA adduct levels with other exposure markers and markers for oxidative stress
DEFF Research Database (Denmark)
Autrup, H; Daneshvar, B; Dragsted, L O;
1999-01-01
Human exposure to genotoxic compounds present in ambient air has been studied using selected biomarkers in nonsmoking Danish bus drivers and postal workers. A large interindividual variation in biomarker levels was observed. Significantly higher levels of bulky carcinogen-DNA adducts (75.42 adducts....../10(8) nucleotides) and of 2-amino-apidic semialdehyde (AAS) in plasma proteins (56.7 pmol/mg protein) were observed in bus drivers working in the central part of Copenhagen, Denmark. In contrast, significantly higher levels of AAS in hemoglobin (55.8 pmol/mg protein), malondialdehyde in plasma (0. 96...... nmol/ml plasma), and polycyclic aromatic hydrocarbon (PAH)-albumin adduct (3.38 fmol/ microg albumin) were observed in the suburban group. The biomarker levels in postal workers were similar to the levels in suburban bus drivers. In the combined group of bus drivers and postal workers, negative...
12. Biomarkers for exposure to ambient air pollution - Comparison of carcinogen-DNA adduct levels with other exposure markers and markers for oxidative stress
DEFF Research Database (Denmark)
Autrup, Herman; Daneshvar, Bahram; Dragsted, Lars Ove;
1999-01-01
Human exposure to genotoxic compounds present in ambient air has been studied using selected biomarkers in nonsmoking Danish bus drivers and postal workers. A large interindividual variation in biomarker levels was observed. Significantly higher levels of bulky carcinogen-DNA adducts (75.42 adducts....../10(8) nucleotides) and of 2-amino-apidic semialdehyde (AAS) in plasma proteins (56.7 pmol/mg protein) were observed in bus drivers working in the central part of Copenhagen, Denmark. In contrast, significantly higher levels of AAS in hemoglobin (55.8 pmol/mg protein), malondialdehyde in plasma (0.......96 nmol/ml plasma), and polycyclic aromatic hydrocarbon (PAH)-albumin adduct (3.38 fmol/mu g albumin) were observed in the suburban group. The biomarker levels in postal workers were similar to the levels in suburban bus drivers. In the combined group of bus drivers and postal workers, negative...
13. In Vitro Bypass of the Major Malondialdehyde- and Base Propenal-Derived DNA Adduct by Human Y-family DNA Polymerases κ, ι, and Rev1†
OpenAIRE
Maddukuri, Leena; Robert L Eoff; Choi, Jeong-Yun; Rizzo, Carmelo J.; Guengerich, F. Peter; Marnett, Lawrence J.
2010-01-01
3-(2′-Deoxy-β-d-erythro-pentofuranosyl)pyrimido-[1,2-a]purin-10(3H)-one (M1dG) is the major adduct derived from the reaction of DNA with the lipid peroxidation product malondialdehyde and the DNA peroxidation product base propenal. M1dG is mutagenic in Escherichia coli and mammalian cells, inducing base-pair substitutions (M1dG → A and M1dG → T) and frameshift mutations. Y-family polymerases may contribute to the mutations induced by M1dG in vivo. Previous reports described the bypass of M1dG...
14. Needle breakage: incidence and prevention.
Science.gov (United States)
Malamed, Stanley F; Reed, Kenneth; Poorsattar, Susan
2010-10-01
Since the introduction of nonreusable, stainless steel dental local anesthetic needles, needle breakage has become an extremely rare complication of dental local anesthetic injections. But although rare, dental needle breakage can, and does, occur. Review of the literature and personal experience brings into focus several commonalities which, when avoided, can minimize the risk of needle breakage with the fragment being retained from occurring.
15. Sequence-specific Hydrolysis of Single-stranded DNA by PNA-Cerium (Ⅳ) Adduct
Institute of Scientific and Technical Information of China (English)
He Bai SHEN; Feng WANG; Yong Tao YANG
2005-01-01
A novel artificial site specific cleavage reagent, with peptide nucleic acid (PNA) as sequence-recognizing moiety and cerium (Ⅳ) ions as "scissors" for cleaving target DNA, was synthesized. Subsequently, it was employed in the cleavage of target 26-mer single-stranded DNA (ssDNA), which has 10-mer sequence complementary with PNA recognizer in the hybrids,under physiological conditions. Reversed-phase high-performance liquid chromatogram (RPHPLC) experiments indicated that the artificial site specific cleavage reagent could cleave the target DNA specifically.
16. Cisplatin adducts on a GGG sequence within a DNA duplex studied by NMR spectroscopy and molecular dynamics simulations.
Science.gov (United States)
Téletchéa, Stéphane; Skauge, Tormod; Sletten, Einar; Kozelka, Jirí
2009-11-16
17. APE1, the DNA base excision repair protein, regulates the removal of platinum adducts in sensory neuronal cultures by NER
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyun-Suk [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States); Guo, Chunlu; Thompson, Eric L. [Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Jiang, Yanlin [Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Kelley, Mark R. [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States); Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Department of Pediatrics and Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202 (United States); Vasko, Michael R. [Department of Pharmacology and Toxicology, Indianapolis, IN 46202 (United States); Lee, Suk-Hee, E-mail: slee@iu.edu [Department of Biochemistry and Molecular Biology, Indianapolis, IN 46202 (United States)
2015-09-15
Peripheral neuropathy is one of the major side effects of treatment with the anticancer drug, cisplatin. One proposed mechanism for this neurotoxicity is the formation of platinum adducts in sensory neurons that could contribute to DNA damage. Although this damage is largely repaired by nuclear excision repair (NER), our previous findings suggest that augmenting the base excision repair pathway (BER) by overexpressing the repair protein APE1 protects sensory neurons from cisplatin-induced neurotoxicity. The question remains whether APE1 contributes to the ability of the NER pathway to repair platinum-damage in neuronal cells. To examine this, we manipulated APE1 expression in sensory neuronal cultures and measured Pt-removal after exposure to cisplatin. When neuronal cultures were treated with increasing concentrations of cisplatin for two or three hours, there was a concentration-dependent increase in Pt-damage that peaked at four hours and returned to near baseline levels after 24 h. In cultures where APE1 expression was reduced by ∼80% using siRNA directed at APE1, there was a significant inhibition of Pt-removal over eight hours which was reversed by overexpressing APE1 using a lentiviral construct for human wtAPE1. Overexpressing a mutant APE1 (C65 APE1), which only has DNA repair activity, but not its other significant redox-signaling function, mimicked the effects of wtAPE1. Overexpressing DNA repair activity mutant APE1 (226 + 177APE1), with only redox activity was ineffective suggesting it is the DNA repair function of APE1 and not its redox-signaling, that restores the Pt-damage removal. Together, these data provide the first evidence that a critical BER enzyme, APE1, helps regulate the NER pathway in the repair of cisplatin damage in sensory neurons.
18. APE1, the DNA base excision repair protein, regulates the removal of platinum adducts in sensory neuronal cultures by NER
International Nuclear Information System (INIS)
Peripheral neuropathy is one of the major side effects of treatment with the anticancer drug, cisplatin. One proposed mechanism for this neurotoxicity is the formation of platinum adducts in sensory neurons that could contribute to DNA damage. Although this damage is largely repaired by nuclear excision repair (NER), our previous findings suggest that augmenting the base excision repair pathway (BER) by overexpressing the repair protein APE1 protects sensory neurons from cisplatin-induced neurotoxicity. The question remains whether APE1 contributes to the ability of the NER pathway to repair platinum-damage in neuronal cells. To examine this, we manipulated APE1 expression in sensory neuronal cultures and measured Pt-removal after exposure to cisplatin. When neuronal cultures were treated with increasing concentrations of cisplatin for two or three hours, there was a concentration-dependent increase in Pt-damage that peaked at four hours and returned to near baseline levels after 24 h. In cultures where APE1 expression was reduced by ∼80% using siRNA directed at APE1, there was a significant inhibition of Pt-removal over eight hours which was reversed by overexpressing APE1 using a lentiviral construct for human wtAPE1. Overexpressing a mutant APE1 (C65 APE1), which only has DNA repair activity, but not its other significant redox-signaling function, mimicked the effects of wtAPE1. Overexpressing DNA repair activity mutant APE1 (226 + 177APE1), with only redox activity was ineffective suggesting it is the DNA repair function of APE1 and not its redox-signaling, that restores the Pt-damage removal. Together, these data provide the first evidence that a critical BER enzyme, APE1, helps regulate the NER pathway in the repair of cisplatin damage in sensory neurons
19. Serum Level of Antibody against Benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA Adducts in People Dermally Exposed to PAHs
Directory of Open Access Journals (Sweden)
Lenka Borska
2014-01-01
Full Text Available Some specific antibodies indicate the presence of antigenic structures on DNA (DNA adducts that can play an important role in the process of mutagenesis and/or carcinogenesis. They indicate the presence of increased genotoxic potential (hazard prior to the formation of disease (primary prevention. The present study was focused on the serum level of benzo[a]pyrene 7,8-diol-9,10-epoxide-DNA adducts antibodies (anti-BPDE-DNA in psoriatic patients (n=55 dermally exposed to different levels of polycyclic aromatic hydrocarbons (PAHs. The general goal of the study was to contribute to better understanding of the value of the assumed biomarker (anti-BPDE-DNA for evaluation of the organism's answer to genotoxic exposure to PAHs. Elevated level of exposure to PAHs resulted in the increased level of anti-BPDE-DNA. However, almost all levels of anti-BPDE-DNA ranged within the field of low values. Both variants of GT (CCT-3% and CCT-5% induced higher expression of anti-BPDE-DNA in the group of nonsmokers. Significant relations between the level of anti-BPDE-DNA and PASI score, total duration of the therapy, or time of UVR exposure were not found. Further studies are needed to reduce interpretation uncertainty of this promising bioindicator.
20. Direct reduction of N-acetoxy-PhIP by tea polyphenols: a possible mechanism for chemoprevention against PhIP-DNA adduct formation
International Nuclear Information System (INIS)
The chemopreventive effect of tea against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-DNA adduct formation and its mechanism were studied. Rats were exposed to freshly prepared aqueous extracts of green tea (3% (w/v)) as the sole source of drinking water for 10 days prior to administration with a single dose of PhIP (10 mg/kg body weight) by oral gavage. PhIP-DNA adducts in the liver, colon, heart, and lung were measured using the 32P-postlabelling technique. Rats pre-treated with tea and given PhIP 20 h before sacrifice had significantly reduced levels of PhIP-DNA adducts as compared with controls given PhIP alone. The possible mechanism of protective effect of tea on PhIP-DNA adduct formation was then examined in vitro. It was found that an aqueous extract of green and black tea, mixtures of green and black tea polyphenols, as well as purified polyphenols could strongly inhibit the DNA binding of N-acetoxy-PhIP, a putative ultimate carcinogen of PhIP formed in vivo via metabolic activation. Among these, epigallocatechin gallate was exceptionally potent. HPLC analyses of these incubation mixtures containing N-acetoxy-PhIP and the tea polyphenols each revealed the production of the parent amine, PhIP, indicating the involvement of a redox mechanism. In view of the presence of relatively high levels of tea polyphenols in rat and human plasma after ingestion of tea, this study suggests that direct reduction of the ultimate carcinogen N-acetoxy-PhIP by tea polyphenols is likely to be involved in the mechanism of chemoprotection of tea against this carcinogen
1. Effects of Black Raspberry Extract and Protocatechuic Acid on Carcinogen-DNA Adducts and Mutagenesis, and Oxidative Stress in Rat and Human Oral Cells.
Science.gov (United States)
Guttenplan, Joseph B; Chen, Kun-Ming; Sun, Yuan-Wan; Kosinska, Wieslawa; Zhou, Ying; Kim, Seungjin Agatha; Sung, Youngjae; Gowda, Krishne; Amin, Shantu; Stoner, Gary D; El-Bayoumy, Karam
2016-08-01
Effects of black raspberry (BRB) extract and protocatechuic acid (PCA) on DNA adduct formation and mutagenesis induced by metabolites of dibenzo[a,l]pyrene (DBP) were investigated in rat oral fibroblasts. The DBP metabolites, (±)-anti-11,12-dihydroxy-11,12,-dihydrodibenzo[a,l]pyrene (DBP-diol) and 11,12-dihydroxy-13,14-epoxy-11,12,13,14-tetrahydrodibenzo[a,l]pyrene (DBPDE) induced dose-dependent DNA adducts and mutations. DBPDE was considerably more potent, whereas the parent compound had no significant effect. Treatment with BRB extract (BRBE) and PCA resulted in reduced DBP-derived DNA adduct levels and reduced mutagenesis induced by DBP-diol, but only BRBE was similarly effective against (DBPDE). BRBE did not directly inactivate DBPDE, but rather induced a cellular response-enhanced DNA repair. When BRBE was added to cells 1 day after the DBP-diol, the BRBE greatly enhanced removal of DBP-derived DNA adducts. As oxidative stress can contribute to several stages of carcinogenesis, BRBE and PCA were investigated for their abilities to reduce oxidative stress in a human leukoplakia cell line by monitoring the redox indicator, 2',7'-dichlorodihydrofluorescein diacetate (H2DCF) in cellular and acellular systems. BRBE effectively inhibited the oxidation, but PCA was only minimally effective against H2DCF. These results taken together provide evidence that BRBE and PCA can inhibit initiation of carcinogenesis by polycyclic aromatic hydrocarbons; and in addition, BRBE reduces oxidative stress. Cancer Prev Res; 9(8); 704-12. ©2016 AACR. PMID:27267891
2. Direct reduction of N-acetoxy-PhIP by tea polyphenols: a possible mechanism for chemoprevention against PhIP-DNA adduct formation
Energy Technology Data Exchange (ETDEWEB)
Lin Dongxin; Thompson, Patricia A.; Teitel, Candee; Chen Junshi; Kadlubar, Fred F
2003-03-01
The chemopreventive effect of tea against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-DNA adduct formation and its mechanism were studied. Rats were exposed to freshly prepared aqueous extracts of green tea (3% (w/v)) as the sole source of drinking water for 10 days prior to administration with a single dose of PhIP (10 mg/kg body weight) by oral gavage. PhIP-DNA adducts in the liver, colon, heart, and lung were measured using the {sup 32}P-postlabelling technique. Rats pre-treated with tea and given PhIP 20 h before sacrifice had significantly reduced levels of PhIP-DNA adducts as compared with controls given PhIP alone. The possible mechanism of protective effect of tea on PhIP-DNA adduct formation was then examined in vitro. It was found that an aqueous extract of green and black tea, mixtures of green and black tea polyphenols, as well as purified polyphenols could strongly inhibit the DNA binding of N-acetoxy-PhIP, a putative ultimate carcinogen of PhIP formed in vivo via metabolic activation. Among these, epigallocatechin gallate was exceptionally potent. HPLC analyses of these incubation mixtures containing N-acetoxy-PhIP and the tea polyphenols each revealed the production of the parent amine, PhIP, indicating the involvement of a redox mechanism. In view of the presence of relatively high levels of tea polyphenols in rat and human plasma after ingestion of tea, this study suggests that direct reduction of the ultimate carcinogen N-acetoxy-PhIP by tea polyphenols is likely to be involved in the mechanism of chemoprotection of tea against this carcinogen.
3. DNA adduct formation and oxidative stress in colon and liver of Big Blue (R) rats after dietary exposure to diesel particles
DEFF Research Database (Denmark)
Dybdahl, M.; Risom, L.; Møller, P.;
2003-01-01
Exposure to diesel exhaust particles (DEP) via the gastrointestinal route may impose risk of cancer in the colon and liver. We investigated the effects of DEP given in the diet to Big Blue(R) rats by quantifying a panel of markers of DNA damage and repair, mutation, oxidative damage to proteins...... in liver accompanied by enhanced vitamin C levels. In plasma, we found no significant effects on oxidative damage to proteins and lipids, antioxidant enzymes or vitamin C levels. Our data indicate that gastrointestinal exposure to DEP induces DNA adducts and oxidative stress resulting in DNA strand breaks...
4. DNA adducts induced by in vitro activation of diesel and biodiesel exhaust extracts
Science.gov (United States)
The abstract reports the results of studies assessing the relative DNA damage potential of extracts of exhaust particles resulting from the combustion of petroleum diesel, biodiesel, and petroleum diesel-biodiesel blends. Results indicate that the commercially available B20 petr...
5. Molecular modeling and spectroscopic studies of semustine binding with DNA and its comparison with lomustine-DNA adduct formation.
Science.gov (United States)
Agarwal, Shweta; Chadha, Deepti; Mehrotra, Ranjana
2015-01-01
Chloroethyl nitrosoureas constitute an important family of cancer chemotherapeutic agents, used in the treatment of various types of cancer. They exert antitumor activity by inducing DNA interstrand cross-links. Semustine, a chloroethyl nitrosourea, is a 4-methyl derivative of lomustine. There exist some interesting reports dealing with DNA-binding properties of chloroethyl nitrosoureas; however, underlying mechanism of cytotoxicity caused by semustine has not been precisely and completely delineated. The present work focuses on understanding semustine-DNA interaction to comprehend its anti-proliferative action at molecular level using various spectroscopic techniques. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy is used to determine the binding site of semustine on DNA. Conformational transition in DNA after semustine complexation is investigated using circular dichroism (CD) spectroscopy. Stability of semustine-DNA complexes is determined using absorption spectroscopy. Results of the present study demonstrate that semustine performs major-groove-directed DNA alkylation at guanine residues in an incubation-time-drug-concentration-dependent manner. CD spectral outcomes suggest partial transition of DNA from native B-conformation to C-form. Calculated binding constants (Ka) for semustine and lomustine interactions with DNA are 1.53 × 10(3) M(-1) and 8.12 × 10(3) M(-1), respectively. Moreover, molecular modeling simulation is performed to predict preferential binding orientation of semustine with DNA that corroborates well with spectral outcomes. Results based on comparative study of DNA-binding properties of semustine and lomustine, presented here, may establish a correlation between molecular structure and cytotoxicity of chloroethyl nitrosoureas that may be instrumental in the designing and synthesis of new nitrosourea therapeutics possessing better efficacy and fewer side effects. PMID:25350567
6. Variation in PAH-related DNA adduct levels among non-smokers: the role of multiple genetic polymorphisms and nucleotide excision repair phenotype
OpenAIRE
Etemadi, Arash; Islami, Farhad; Phillips, David H.; Godschalk, Roger; Golozar, Asieh; Kamangar, Farin; Malekshah, Akbar Fazel-Tabar; Pourshams, Akram; Elahi, Seerat; Ghojaghi, Farhad; Strickland, Paul T.; Taylor, Philip R.; Boffetta, Paolo; Abnet, Christian C.; Dawsey, Sanford M.
2012-01-01
Polycyclic aromatic hydrocarbons (PAHs) likely play a role in many cancers even in never-smokers. We tried to find a model to explain the relationship between variation in PAH-related DNA adduct levels among people with similar exposures, multiple genetic polymorphisms in genes related to metabolic and repair pathways, and nucleotide excision repair (NER) capacity. In 111 randomly selected female never-smokers from the Golestan Cohort Study in Iran, we evaluated 21 SNPs in 14 genes related to...
7. DNA Adduct Formation from Metabolic 5'-Hydroxylation of the Tobacco-Specific Carcinogen N'-Nitrosonornicotine in Human Enzyme Systems and in Rats.
Science.gov (United States)
2016-03-21
N'-Nitrosonornicotine (NNN) is carcinogenic in multiple animal models and has been evaluated as a human carcinogen. NNN can be metabolized by cytochrome P450s through two activation pathways: 2'-hydroxylation and 5'-hydroxylation. While most previous studies have focused on 2'-hydroxylation in target tissues of rats, available evidence suggests that 5'-hydroxylation is a major activation pathway in human enzyme systems, in nonhuman primates, and in target tissues of some other rodent carcinogenicity models. In the study reported here, we investigated DNA damage resulting from NNN 5'-hydroxylation by quantifying the adduct 2-(2-(3-pyridyl)-N-pyrrolidinyl)-2'-deoxyinosine (py-py-dI). In rats treated with NNN in the drinking water (7-500 ppm), py-py-dI was the major DNA adduct resulting from 5'-hydroxylation of NNN in vivo. Levels of py-py-dI in the lung and nasal cavity were the highest, consistent with the tissue distribution of CYP2A3. In rats treated with (S)-NNN or (R)-NNN, the ratios of formation of (R)-py-py-dI to (S)-py-py-dI were not the expected mirror image, suggesting that there may be a carrier for one of the unstable intermediates formed upon 5'-hydroxylation of NNN. Rat hepatocytes treated with (S)- or (R)-NNN or (2'S)- or (2'R)-5'-acetoxyNNN exhibited a pattern of adduct formation similar to that of live rats. In vitro studies with human liver S9 fraction or human hepatocytes incubated with NNN (2-500 μM) demonstrated that py-py-dI formation was greater than the formation of pyridyloxobutyl-DNA adducts resulting from 2'-hydroxylation of NNN. (S)-NNN formed more total py-py-dI adducts than (R)-NNN in human liver enzyme systems, which is consistent with the critical role of CYP2A6 in the 5'-hydroxylation of NNN in human liver. The results of this study demonstrate that the major DNA adduct resulting from NNN metabolism by human enzymes is py-py-dI and provide potentially important new insights into the metabolic activation of NNN in rodents and humans
8. Inhibition of the formation of benzo[a]pyrene adducts to DNA in A549 lung cells exposed to mixtures of polycyclic aromatic hydrocarbons.
Science.gov (United States)
Genies, Camille; Jullien, Amandine; Lefebvre, Emmanuel; Revol, Morgane; Maitre, Anne; Douki, Thierry
2016-09-01
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants, which exhibit carcinogenic properties especially in lungs. In the present work, we studied the effect of mixtures of 12 PAHs on the A549 alveolar cells. We first assess the ability of each PAH at inducing gene expression of phase I metabolization enzymes and at generating DNA adducts. A good correlation was found between these two endpoints. We then exposed cells to either binary mixtures of the highly genotoxic benzo[a]pyrene (B[a]P) with each PAH or complex mixtures of all studied PAHs mimicking by real emissions including combustion of wood, cigarette smoke, and atmospheres of garage, silicon factory and urban environments. Compared to pure B[a]P, both types of mixtures led to reduced CYP450 activity measured by the EROD test. A similar trend was observed for the formation of DNA adducts. Surprisingly, the complex mixtures were more potent than B[a]P used at the same concentration for the induction of genes coding for CYP. Our results stress the lack of additivity of the genotoxic properties of PAH in mixtures. Interestingly, an opposite synergy in the formation of B[a]P adducts were observed previously in hepatocytes. Our data also show that measurement of the metabolic activity rather than quantification of gene expression reflects the actual bioactivation of PAHs into DNA damaging species. PMID:27196671
9. Effect of increased intake of dietary animal fat and fat energy on oxidative damage, mutation frequency, DNA adduct level and DNA repair in rat colon and liver
DEFF Research Database (Denmark)
Vogel, Ulla Birgitte; Danesvar, B.; Autrup, H.;
2003-01-01
The effect of high dietary intake of animal fat and an increased fat energy intake on colon and liver genotoxicity and on markers of oxidative damage and antioxidative defence in colon, liver and plasma was investigated in Big Blue rats. The rats were fed ad libitum with semi-synthetic feed...... supplemented with 0, 3, 10 or 30% w/w lard. After 3 weeks, the mutation frequency, DNA repair gene expression, DNA damage and oxidative markers were determined in liver, colon and plasma. The mutation frequency of the lambda gene cII did not increase with increased fat or energy intake in colon or liver....... The DNA-adduct level measured by P-32-postlabelling decreased in both liver and colon with increased fat intake. In liver, this was accompanied by a 2-fold increase of the mRNA level of nucleotide excision repair (NER) gene ERCC1. In colon, a non-statistically significant increase in the ERCC1 mRNA levels...
10. Noni juice reduces lipid peroxidation–derived DNA adducts in heavy smokers
OpenAIRE
Wang, Mian-Ying; Peng, Lin; Jensen, Claude J; Deng, Shixin; Brett J. West
2013-01-01
Food plants provide important phytochemicals which help improve or maintain health through various biological activities, including antioxidant effects. Cigarette smoke–induced oxidative stress leads to the formation of lipid hydroperoxides (LOOHs) and their decomposition product malondialdehyde (MDA), both of which cause oxidative damage to DNA. Two hundred forty-five heavy cigarette smokers completed a randomized, double-blind, placebo-controlled clinical trial designed to investigate the e...
11. Astragalin from Cassia alata induces DNA adducts in vitro and repairable DNA damage in the yeast Saccharomyces cerevisiae.
Science.gov (United States)
Saito, Samuel; Silva, Givaldo; Santos, Regineide Xavier; Gosmann, Grace; Pungartnik, Cristina; Brendel, Martin
2012-01-01
Reverse phase-solid phase extraction from Cassia alata leaves (CaRP) was used to obtain a refined extract. Higher than wild-type sensitivity to CaRP was exhibited by 16 haploid Saccharomyces cerevisiae mutants with defects in DNA repair and membrane transport. CaRP had a strong DPPH free radical scavenging activity with an IC(50) value of 2.27 μg mL(-1) and showed no pro-oxidant activity in yeast. CaRP compounds were separated by HPLC and the three major components were shown to bind to DNA in vitro. The major HPLC peak was identified as kampferol-3-O-β-d-glucoside (astragalin), which showed high affinity to DNA as seen by HPLC-UV measurement after using centrifugal ultrafiltration of astragalin-DNA mixtures. Astragalin-DNA interaction was further studied by spectroscopic methods and its interaction with DNA was evaluated using solid-state FTIR. These and computational (in silico) docking studies revealed that astragalin-DNA binding occurs through interaction with G-C base pairs, possibly by intercalation stabilized by H-bond formation.
12. Metabolism of aflatoxin B1 and identification of the major aflatoxin B1-DNA adducts formed in cultured human bronchus and colon
DEFF Research Database (Denmark)
1979-01-01
Aflatoxin B1 and benzo(a)pyrene were activated by both cultured human bronchus and human colon as measured by binding to cellular DNA and protein. The binding of aflatoxin B1 to DNA was dose dependent, and the level of binding was higher in cultured human bronchus than it was in the colon. When...... compared to aflatoxin B1, the binding level of benzo(a)pyrene to both bronchial and colonic DNA was generally higher. The major adducts formed in both tissues by the interaction of aflatoxin B1 and DNA were chromatographically identical to 2,3-dihydro-2-(N7-guanyl)-3-hydroxyaflatoxin B1 (Structure 1...... in these two peaks, and the ratio of radioactivity between the peaks was nearly 1. In colonic DNA, the ratio between Structures 1 and 11 was approximately 2. These observations add aflatoxin B1 to the list of chemical procarcinogens metabolized by cultured human tissues and in which the carcinogen-DNA adducts...
13. Insertion of dNTPs Opposite the 1,N[superscript 2]-Propanodeoxyguanosine Adduct by Sulfolobus solfataricus P2 DNA Polymerase IV
Energy Technology Data Exchange (ETDEWEB)
Wang, Yazhen; Musser, Sarah K.; Saleh, Sam; Marnett, Lawrence J.; Egli, Martin; Stone, Michael P. (Vanderbilt)
2008-08-04
1,N{sup 2}-Propanodeoxyguanosine (PdG) is a stable structural analogue for the 3-(2'-deoxy-{beta}-d-erythro-pentofuranosyl)pyrimido[1,2-?]purin-10(3H)-one (M{sub 1}dG) adduct derived from exposure of DNA to base propenals and to malondialdehyde. The structures of ternary polymerase-DNA-dNTP complexes for three template-primer DNA sequences were determined, with the Y-family Sulfolobus solfataricus DNA polymerase IV (Dpo4), at resolutions between 2.4 and 2.7 {angstrom}. Three template 18-mer-primer 13-mer sequences, 5'-d(TCACXAAATCCTTCCCCC)-3'{center_dot}5'-d(GGGGGAAGGATTT)-3' (template I), 5'-d(TCACXGAATCCTTCCCCC)-3'{center_dot}5'-d(GGGGGAAGGATTC)-3' (template II), and 5'-d(TCATXGAATCCTTCCCCC)-3'{center_dot}5'-d(GGGGGAAGGATTC)-3' (template III), where X is PdG, were analyzed. With templates I and II, diffracting ternary complexes including dGTP were obtained. The dGTP did not pair with PdG, but instead with the 5'-neighboring template dC, utilizing Watson-Crick geometry. Replication bypass experiments with the template-primer 5?-TCACXAAATCCTTACGAGCATCGCCCCC-3'{center_dot}5'-GGGGGCGATGCTCGTAAGGATTT-3', where X is PdG, which includes PdG in the 5'-CXA-3' template sequence as in template I, showed that the Dpo4 polymerase inserted dGTP and dATP when challenged by the PdG adduct. For template III, in which the template sequence was 5'-TXG-3', a diffracting ternary complex including dATP was obtained. The dATP did not pair with PdG, but instead with the 5'-neighboring T, utilizing Watson-Crick geometry. Thus, all three ternary complexes were of the 'type II' structure described for ternary complexes with native DNA [Ling, H., Boudsocq, F., Woodgate, R., and Yang, W. (2001) Cell 107, 91--102]. The PdG adduct remained in the anti conformation about the glycosyl bond in each of these threee ternary complexes. These results provide insight into how -1
14. Ring-Opening of the γ-OH-PdG Adduct Promotes Error-Free Bypass by the Sulfolobus solfataricus DNA Polymerase Dpo4
OpenAIRE
Shanmugam, Ganesh; Minko, Irina G.; Banerjee, Surajit; Christov, Plamen P.; Kozekov, Ivan D.; Rizzo, Carmelo J.; Lloyd, R. Stephen; Egli, Martin; Michael P. Stone
2013-01-01
Acrolein, a mutagenic aldehyde, reacts with deoxyguanosine (dG) to form 3-(2′-deoxy-β-d-erythro-pentofuranosyl)-5,6,7,8-tetrahydro-8-hydroxypyrimido[1,2-a] purin-10(3H)-one (γ-OH-PdG). When placed opposite deoxycytosine (dC) in DNA, γ-OH-PdG undergoes ring-opening to the N 2-(3-oxopropyl)-dG. Ring-opening of the adduct has been hypothesized to facilitate nonmutagenic bypass, particularly by DNA polymerases of the Y family. This study examined the bypass of γ-OH-PdG by Sulfolobus solfataricus ...
15. Benzo pyrene-induced DNA adducts and gene expression profiles in target and non-target organs for carcinogenesis in mice
OpenAIRE
Zuo, Jie; Brewer, Daniel S; Arlt, Volker M.; Colin S. Cooper; Phillips, David H.
2014-01-01
Background Gene expression changes induced by carcinogens may identify differences in molecular function between target and non-target organs. Target organs for benzo[a]pyrene (BaP) carcinogenicity in mice (lung, spleen and forestomach) and three non-target organs (liver, colon and glandular stomach) were investigated for DNA adducts by 32P-postlabelling, for gene expression changes by cDNA microarray and for miRNA expression changes by miRNA microarray after exposure of animals to BaP. Resul...
16. Single-stranded oligonucleotide adducts formed by Pt complexes favoring left-handed base canting: steric effect of flanking residues and relevance to DNA adducts formed by Pt anticancer drugs.
Science.gov (United States)
Saad, Jamil S; Marzilli, Patricia A; Intini, Francesco P; Natile, Giovanni; Marzilli, Luigi G
2011-09-01
17. 3,2'-Dimethyl-4-aminobiphenyl-DNA adduct formation in tumor target and nontarget organs of rapid and slow acetylator Syrian hamsters cogenic at the NAT2 locus.
Science.gov (United States)
Feng, Y; Jiang, W; Deitz, A C; Hein, D W
1996-10-01
18. Accumulation and persistence of nicotine derived DNA and hemoglobin adducts in mice after multiple administration of {sup 14}C-nicotine at low dose level
Energy Technology Data Exchange (ETDEWEB)
Sun, Hongfang; Li, Hongli; Zhu, Jiadan; Wang, Haifang; Liu, Yuanfang [Peking Univ., Beijing (China). Dept. of Chemical Biology, College of Chemistry and Molecular Engineering; Liu, Kexin; Peng, Shixiang [Peking Univ., Beijing (China). Inst. of Heavy Ion Physics, School of Physics
2004-07-01
The hypothetic role of nicotine in causing smoking related diseases has not been well established. Based on our early finding of the genotoxicity of nicotine, a sub-chronic study on the accumulation and persistence of nicotine derived DNA and hemoglobin (Hb) adducts in mice following multiple low dose exposures was carried out by accelerator mass spectrometry (AMS). AMS is a sophisticated ultrasensitive nuclear method, which facilitates the detection of adduction of DNA and other bio-macromolecules with xenobiotics at human relevant environmental dose levels. Briefly, in this study [N-{sup 14}CH{sub 3}]-nicotine (s.a. 16.2 {mu}Ci/{mu}mol) was administered to mice by gavage once daily at 3.0 {mu}g/kg b.w., which is equivalent to an estimated nicotine dose inhaled by a 70 kg person smoking 5 cigarettes, for 14 consecutive days. Lung DNA, liver DNA and Hb were isolated from tissues and blood samples which were collected at 1, 3, 5, 7, 10, 14, 15, 17, 21 and 25 days time point, respectively. (orig.)
19. Resistance to Nucleotide Excision Repair of Bulky Guanine Adducts Opposite Abasic Sites in DNA Duplexes and Relationships between Structure and Function.
Directory of Open Access Journals (Sweden)
Zhi Liu
Full Text Available The nucleotide excision repair of certain bulky DNA lesions is abrogated in some specific non-canonical DNA base sequence contexts, while the removal of the same lesions by the nucleotide excision repair mechanism is efficient in duplexes in which all base pairs are complementary. Here we show that the nucleotide excision repair activity in human cell extracts is moderate-to-high in the case of two stereoisomeric DNA lesions derived from the pro-carcinogen benzo[a]pyrene (cis- and trans-B[a]P-N2-dG adducts in a normal DNA duplex. By contrast, the nucleotide excision repair activity is completely abrogated when the canonical cytosine base opposite the B[a]P-dG adducts is replaced by an abasic site in duplex DNA. However, base excision repair of the abasic site persists. In order to understand the structural origins of these striking phenomena, we used NMR and molecular spectroscopy techniques to evaluate the conformational features of 11mer DNA duplexes containing these B[a]P-dG lesions opposite abasic sites. Our results show that in these duplexes containing the clustered lesions, both B[a]P-dG adducts adopt base-displaced intercalated conformations, with the B[a]P aromatic rings intercalated into the DNA helix. To explain the persistence of base excision repair in the face of the opposed bulky B[a]P ring system, molecular modeling results suggest how the APE1 base excision repair endonuclease, that excises abasic lesions, can bind productively even with the trans-B[a]P-dG positioned opposite the abasic site. We hypothesize that the nucleotide excision repair resistance is fostered by local B[a]P residue-DNA base stacking interactions at the abasic sites, that are facilitated by the absence of the cytosine partner base in the complementary strand. More broadly, this study sets the stage for elucidating the interplay between base excision and nucleotide excision repair in processing different types of clustered DNA lesions that are substrates of
20. In vitro studies of the genotoxic effects of bitumen and coal-tar fume condensates: comparison of data obtained by mutagenicity testing and DNA adduct analysis by 32P-postlabelling.
Science.gov (United States)
De Méo, M; Genevois, C; Brandt, H; Laget, M; Bartsch, H; Castegnaro, M
1996-08-14
1. In vitro studies of the genotoxic effects of bitumen and coal-tar fume condensates: comparison of data obtained by mutagenicity testing and DNA adduct analysis by 32P-postlabelling.
Science.gov (United States)
De Méo, M; Genevois, C; Brandt, H; Laget, M; Bartsch, H; Castegnaro, M
1996-08-14
2. DNA adducts formed by ring-oxidation of the carcinogen 2-naphthylamine with prostaglandin H synthase in vitro and in the dog urothelium in vivo
International Nuclear Information System (INIS)
The presence of relatively high levels of prostaglandin H synthase (PHS) in the dog urinary bladder and its ability to mediate the activation of carcinogenic arylamines to DNA-bound products in vitro suggests the involvement of this enzyme in arylamine-induced bladder carcinogenesis. Since the PHS-dependent metabolism of 2-naphthylamine (2-NA) had been shown to yield both ring- and N-oxidation products in vitro, the authors compared the reactivity of 3H-labeled N-hydroxy-2-naphthylamine (N-OH-2-NA), 2-nitrosonaphthalene, and 2-amino-1-naphthol (2-AN) toward DNA and protein. In the PHS-incubation system, all three derivatives bound at high levels to protein, but only N-OH-2-NA and 2-AN bound appreciably to DNA. Though ring-oxidation has usually been considered a detoxification pathway, the covalent binding of [3H]2-AN to DNA was found to occur readily under aerobic conditions and was enhanced at acidic pH. At pH 5 in air, the reactivity of [3H]2-AN with nucleic acids and protein was in the order: serum albumin greater than tRNA greater than poly G greater than poly C greater than DNA greater than poly A greater than rRNA greater than poly U. Enzymatic hydrolysis of DNA reacted with [3H]2-AN and subsequent analysis by h.p.l.c. indicated the presence of several carcinogen-nucleoside adducts. The major product was characterized as N4-(deoxyguanosin-N2-yl)-2-amino-1,4-naphthoquinoneimine; and two minor products were tentatively identified as N4-(deoxyadenosin-N6-yl)-2-amino-1,4-naphthoquinoneimine and a deoxyguanosin-N2-yl adduct of a naphthoquinoneimine dimer. These adducts accounted for approximately 60% of the total DNA binding obtained by incubation of [3H]2-NA with PHS in vitro and for approximately 20% of the [3H]2-NA bound to dog urothelial DNA in vivo
3. A feasibility study of the use of saliva as an alternative to leukocytes as a source of DNA for the study of Pt-DNA adducts in cancer patients receiving platinum-based chemotherapy.
Science.gov (United States)
Taylor, Sarah E; Wood, Joanna P; Thomas, Anne L; Jones, George D D; Reid, Helen J; Sharp, Barry L
2014-12-01
This note presents a comparison of the use of saliva versus leukocytes for the determination of Pt-DNA adducts obtained from patients undergoing platinum-based chemotherapy. Samples of both blood and saliva were taken pre- and post-treatment and were analysed via sector-field inductively coupled plasma mass spectrometry (SF-ICP-MS) to determine the level of Pt-DNA adducts formed. As expected, significant inter-patient variability was seen; however, a lack of correlation between the levels of adducts observed in saliva and blood samples was also observed (Pearson correlation coefficient r = -0.2598). A high yield of DNA was obtained from saliva samples, but significant difficulties were experienced in obtaining patient adherence to the saliva sampling procedure. In both leukocyte and saliva samples, not only was Pt from previous chemotherapy cycles detected, but the rapid appearance of Pt in the DNA was noted in both sample types 1 h after treatment.
4. 3,N4-ethenocytosine, a highly mutagenic adduct, is a primary substrate for Escherichia coli double-stranded uracil-DNA glycosylase and human mismatch-specific thymine-DNA glycosylase
OpenAIRE
Saparbaev, Murat; Laval, Jacques
1998-01-01
Exocyclic DNA adducts are generated in cellular DNA by various industrial pollutants such as the carcinogen vinyl chloride and by endogenous products of lipid peroxidation. The etheno derivatives of purine and pyrimidine bases 3,N4-ethenocytosine (ɛC), 1,N6-ethenoadenine (ɛA), N2,3-ethenoguanine, and 1,N2-ethenoguanine cause mutations. The ɛA residues are excised by the human and the Escherichia coli 3-methyladenine-DNA glycosylases (ANPG and AlkA proteins, respectively), but the enzymes repa...
5. 32P-postlabeling analysis of DNA adduction in mice by synthetic metabolites of the environmental carcinogen, 7H-dibenzo[c,g]carbazole: chromatographic evidence for 3-hydroxy-7H-dibenzo[c,g]carbazole being a proximate genotoxicant in liver but not skin.
Science.gov (United States)
Schurdak, M E; Stong, D B; Warshawsky, D; Randerath, K
1987-04-01
6. Effect of intense, ultrashort laser pulses on DNA plasmids in their native state: strand breakages induced by {\\it in-situ} electrons
CERN Document Server
D'Souza, J S; Dharmdhikair, A K; Rao, B J; Mathur, D
2010-01-01
Single strand breaks are induced in DNA plasmids, pBR322 and pUC19, in aqueous media by intense ultrashort laser pulses (820 nm wavelength, 45 fs pulse duration, 1 kHz repetition rate) at intensities of 1-12 TW cm$^{-2}$. The intense laser radiation generates, {\\it in situ}, electrons that induce transformation of supercoiled DNA into relaxed DNA. The extent of electron-mediated relaxation of DNA structure is quantified. Introduction of electron and radical scavengers inhibits DNA damage.
7. Effect of intense, ultrashort laser pulses on DNA plasmids in their native state: strand breakages induced by {\\it in-situ} electrons and radicals
CERN Document Server
D'Souza, J S; Dharmadhikari, A K; Rao, B J; Mathur, D
2011-01-01
Single strand breaks are induced in DNA plasmids, pBR322 and pUC19, in aqueous media exposed to strong fields generated using ultrashort laser pulses (820 nm wavelength, 45 fs pulse duration, 1 kHz repetition rate) at intensities of 1-12 TW cm$^{-2}$. The strong fields generate, {\\it in situ}, electrons and radicals that induce transformation of supercoiled DNA into relaxed DNA, the extent of which is quantified. Introduction of electron and radical scavengers inhibits DNA damage; results indicate that OH radicals are the primary (but not sole) cause of DNA damage.
8. In vitro studies of the genotoxic effects of bitumen and coal-tar fume condensates: comparison of data obtained by mutagenicity testing and DNA adduct analysis by {sup 32}P-postlabelling
Energy Technology Data Exchange (ETDEWEB)
De Meo, M.; Genevois, C.; Brandt, H.; Laget, M.; Bartsch, H.; Castegnaro, M. [Laboratoire de Biogenotoxicologie et Mutagenese Environnementale, Marseille (France). Faculte de Pharmcie
1996-08-14
9. Modulations of benzo[a]pyrene-induced DNA adduct, cyclin D1 and PCNA in oral tissue by 1,4-phenylenebis(methylene)selenocyanate
Energy Technology Data Exchange (ETDEWEB)
Chen, Kun-Ming [Department of Biochemistry and Molecular Biology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033 (United States); Sacks, Peter G. [Department of Basic Sciences, College of Dentistry, New York University, New York, NY 10010 (United States); Spratt, Thomas E.; Lin, Jyh-Ming; Boyiri, Telih [Department of Biochemistry and Molecular Biology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033 (United States); Schwartz, Joel [University of Illinois, College of Dentistry, Chicago, IL 60612 (United States); Richie, John P.; Calcagnotto, Ana [Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA 17033 (United States); Das, Arunangshu; Bortner, James [Department of Biochemistry and Molecular Biology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033 (United States); Zhao, Zonglin [Department of Basic Sciences, College of Dentistry, New York University, New York, NY 10010 (United States); Department of Environmental Medicine, School of Medicine, New York University, New York, NY 10010 (United States); Amin, Shantu [Department of Pharmacology, Penn State College of Medicine, Hershey, PA 17033 (United States); Guttenplan, Joseph [Department of Basic Sciences, College of Dentistry, New York University, New York, NY 10010 (United States); Department of Environmental Medicine, School of Medicine, New York University, New York, NY 10010 (United States); El-Bayoumy, Karam, E-mail: kee2@psu.edu [Department of Biochemistry and Molecular Biology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033 (United States)
2009-05-22
Tobacco smoking is an important cause of human oral squamous cell carcinoma (SCC). Tobacco smoke contains multiple carcinogens include polycyclic aromatic hydrocarbons typified by benzo[a]pyrene (B[a]P). Surgery is the conventional treatment approach for SCC, but it remains imperfect. However, chemoprevention is a plausible strategy and we had previously demonstrated that 1,4-phenylenebis(methylene)selenocyanate (p-XSC) significantly inhibited tongue tumors-induced by the synthetic 4-nitroquinoline-N-oxide (not present in tobacco smoke). In this study, we demonstrated that p-XSC is capable of inhibiting B[a]P-DNA adduct formation, cell proliferation, cyclin D1 expression in human oral cells in vitro. In addition, we showed that dietary p-XSC inhibits B[a]P-DNA adduct formation, cell proliferation and cyclin D1 protein expression in the mouse tongue in vivo. The results of this study are encouraging to further evaluate the chemopreventive efficacy of p-XSC initially against B[a]P-induced tongue tumors in mice and ultimately in the clinic.
10. Modulations of benzo[a]pyrene-induced DNA adduct, cyclin D1 and PCNA in oral tissue by 1,4-phenylenebis(methylene)selenocyanate
International Nuclear Information System (INIS)
Tobacco smoking is an important cause of human oral squamous cell carcinoma (SCC). Tobacco smoke contains multiple carcinogens include polycyclic aromatic hydrocarbons typified by benzo[a]pyrene (B[a]P). Surgery is the conventional treatment approach for SCC, but it remains imperfect. However, chemoprevention is a plausible strategy and we had previously demonstrated that 1,4-phenylenebis(methylene)selenocyanate (p-XSC) significantly inhibited tongue tumors-induced by the synthetic 4-nitroquinoline-N-oxide (not present in tobacco smoke). In this study, we demonstrated that p-XSC is capable of inhibiting B[a]P-DNA adduct formation, cell proliferation, cyclin D1 expression in human oral cells in vitro. In addition, we showed that dietary p-XSC inhibits B[a]P-DNA adduct formation, cell proliferation and cyclin D1 protein expression in the mouse tongue in vivo. The results of this study are encouraging to further evaluate the chemopreventive efficacy of p-XSC initially against B[a]P-induced tongue tumors in mice and ultimately in the clinic.
11. Biomonitoring of diesel exhaust-exposed workers. DNA and hemoglobin adducts and urinary 1-hydroxypyrene as markers of exposure
DEFF Research Database (Denmark)
Nielsen, Per Sabro; Andreassen, Åshild; Farmer, Peter B.;
1996-01-01
the 32P-postlabelling method with butanol and P1 enrichment procedures. Hydroxyethylvaline (HOEtVal) adducts in hemoglobin were measured by gas chromatography-mass spectrometry (GC-MS) and 1-hydroxypyrene (HPU) in urine determined using HPLC analysis. The exposed workers had significantly higher levels....... The study indicated that skin absorption of polycyclic aromatic hydrocarbons (PAH) might be an important factor to consider when studying PAH exposure from air pollution sources....
12. 丙烯醛-DNA加合物的研究进展%REVIEW:THE FORMATION AND MUTAGENESIS OF ACROLEIN-DNA ADDUCTS
Institute of Scientific and Technical Information of China (English)
尹瑞川; 汪海林
2011-01-01
丙烯醛是一种活泼的a,β不饱和醛,在环境中广泛存在,香烟烟气和厨房油烟是人体丙烯醛暴露的主要环境来源.另一方面机体内丙烯醛可以通过脂质过氧化、氨基酸氧化等多种途径自发生成.进入人体后,丙烯醛和DNA发生加合生成丙烯醛-DNA加合物,目前研究最多的是丙烯醛-dG加合物,包括a-OH-PdG和γ-OH-PdG,其中γ-OH-PdG是主要dG加合物,可引起基因突变(约1%),以G→T突变为主,而次要加合物a-OH-PdG的突变概率高于γ-OH-PdG(约8%),同样以G→T突变为主,并且这些加合物与一些癌症密切相关,如吸烟相关肺癌和膀胱癌等.此外,丙烯醛可以与其它碱基发生加合,生成其它类型的DNA加合物,包括丙烯醛-dA、dC和dT加合物,其中一些加合物的结构已表征,并在体外反应中存在.%Acrolein, one of the most reactive α,β unsaturated aldehydes, is an ubiquitous environmental pollutant and is found in cigarette smoking and cooking. On the other hand, acrolein can also be endogenously released during lipid peroxidation, myeloperoxidase-mediated degradation of amino acids, and so on. Acrolein can directly react with DNA without metabolic activation. As a result several types of DNA adducts could be produced. Currently, most of studies focus on Acrolein-dG adduct, including α-OH-PdG and γ-OH-PdG. The measured amount of γ-OH-PdG is higher than α-OH-PdG in human body and it can generate about 1％ gene mutation, while gene mutation frequency is 8％ for α-OH-PdG. Both adducts mainly induce G→T mutation.In addition, other base adducts may also be generated in vitro, including Aerolein-dA, dC, and dT adducts.But their metabolism and genotoxicity are unknown. To unbiasedly judge the genotoxicity of acrolein, the formation, metabolism and genotoxicity of non-dG adducts should be considered.
13. Hypersensitivity to ionizing radiation, in vitro, in a new chromosomal breakage disorder, the Nijmegen Breakage Syndrome
International Nuclear Information System (INIS)
The Nijmegen Breakage Syndrome (NBS) is a new chromosomal instability disorder different from ataxia telangiectasia (AT) and other chromosome-breakage syndromes. Cells from an NBS patient appeared hypersensitive to X-irradiation. X-rays induced significantly more chromosomal damage in NBS lymphocytes and fibroblasts than in normal cells. The difference was most pronounced after irradiation in G2. Further, NBS fibroblasts were more readily by X-rays than normal fibroblasts. In addition, the DNA synthesis in NBS cells was more resistant to X-rays and bleomycin than that in normal cells. The reaction of NBS cells to X-rays and bleomycin was similar to that of cells from patients with ataxia telangiectasia. Our results indicate that NBS and AT, which also have similar chromosomal characteristics, must be closely related. (orig.)
14. Hypersensitivity to ionizing radiation, in vitro, in a new chromosomal breakage disorder, the Nijmegen Breakage Syndrome
Energy Technology Data Exchange (ETDEWEB)
Taalman, R.D.F.M.; Scheres, J.M.J.C.; Hustinx, T.W.J. (Katholieke Univ. Nijmegen (Netherlands). Dept. of Human Genetics); Jaspers, N.G.J.; de Wit, J. (Erasmus Universiteit, Rotterdam (Netherlands). Lab. of Cell Biology and Genetics)
1983-02-01
The Nijmegen Breakage Syndrome (NBS) is a new chromosomal instability disorder different from ataxia telangiectasia (AT) and other chromosome-breakage syndromes. Cells from an NBS patient appeared hypersensitive to X-irradiation. X-rays induced significantly more chromosomal damage in NBS lymphocytes and fibroblasts than in normal cells. The difference was most pronounced after irradiation in G/sub 2/. Further, NBS fibroblasts were more readily by X-rays than normal fibroblasts. In addition, the DNA synthesis in NBS cells was more resistant to X-rays and bleomycin than that in normal cells. The reaction of NBS cells to X-rays and bleomycin was similar to that of cells from patients with ataxia telangiectasia. Our results indicate that NBS and AT, which also have similar chromosomal characteristics, must be closely related.
15. Chemoprevention of 2-amino-1-methyl-6-phenylimidazo［4,5-b］pyridine-induced carcinogen-DNA adducts by Chinese cabbage in rats
Institute of Scientific and Technical Information of China (English)
1999-01-01
AIM The food-borne carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) induces colon and mammary gland tumors in rats and has been implicated in the etiology of human colorectal cancer. This study was conducted to examine the potentially preventive effect of Chinese cabbage (Brassica chinensis), a brassica vegetable most commonly consumed in China, against this carcinogen-induced DNA adduct formation in rats and its possible mechanisms.METHODS Sprague-Dawley rats were maintained for 10 days on basal diet or diet containing 20% (w/ w) freeze-dried cabbage powder prior to administration of a single dose of PhIP (10 mg/ kg) by oral gavage. Rats were sacrificed at 20 h after PhIP treatment and PhIP-DNA adducts in the colon, heart, lung and liver were analyzed using 32P-postlabeling technique. Levels of hepatic cytochrome P450 (CYP) 1A1 and 1A2, as indicated by 7-ethoxyresorufin O-deethylase and 7-methlxyresorufin O-demethylase activity, and cytosolic glutathione S-transferases (GSTs) towards 1-chloro-2, 4-dinitrobenzene (CDNB) in the liver, lung and colon were measured.RESULTS Rats pre-treated with Chinese cabbage and given a single dose of PhIP had reduced levels of PhIP-DNA adducts in the colon, heart, lung and liver, with inhibition rates of 82.3%, 60.6%, 48.4% and 48.9%, respectively (P＜0.01). The enzyme assays revealed that Chinese cabbage induced both CYP1A1 and 1A2 activity, but the induction was preferential for CYP1A1 over 1A2 (81% vs 51%). GST activity towards CDNB in the liver and lung, but not colon, was also significantly increased by cabbage treatment.CONCLUSION The results indicate that Chinese cabbage has a preventive effect on PhIP-initiated carcinogenesis in rats and the mechanism is likely to involve the induction of detoxification enzymes.
16. Reduced nucleotide excision repair and GSTM1-null genotypes influence anti-B(a)PDE-DNA adduct levels in mononuclear white blood cells of highly PAH-exposed coke oven workers
Energy Technology Data Exchange (ETDEWEB)
Sofia Pavanello; Alessandra Pulliero; Ewa Siwinska; Danuta Mielzynska; Erminio Clonfero [University of Padova, Padova (Italy). Occupational Health Section, Department of Environmental Medicine and Public Health
2005-07-01
It is important to identify the potential genetic-susceptible factors that are able to modulate individual responses to exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs). In the present study we evaluated the influence of four polymorphisms of nucleotide excision repair (NER) genes and that of glutathione S-transferase {mu}1 (GSTM1-active or -null) on benzo(a)pyrene diol epoxide (B(a)PDE)-DNA adduct levels from the lympho-monocyte fraction (LMF) of highly PAH benzo(a)pyrene -exposed Polish coke oven workers with individual urinary post-shift excretion of 1-pyrenol exceeding the proposed biological exposure index. The bulky {+-}-r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene (anti-B(a)PDE)-DNA adduct levels were detected by high-performance liquid chromatography fluorescence analysis and genotypes by polymerase chain reaction. We found that workers with the low DNA repair capacity of XPC-PAT+/+ and XPA-A23A genotypes had increased anti-B(a)PDE-DNA adduct levels, DNA adducts were also raised in workers without GSTM1 activity. Workers with unfavourable XPC-PAT+/+ and XPA-A23A NER genotypes, alone or combined with GSTM1-null genotype were in the tertile with the highest adduct level. The increase in anti-B(a)PDE-DNA adduct levels was related in a multiple linear regression analysis to PAH exposure lack of GSTM1 activity and to low DNA repair capacity of the XPC-PAT+/+ genotype. The influence of the XPA-A23A genotype was not evident in this statistical analysis, and no associations with XPD polymorphisms, dietary habits or tobacco smoking were found. The modulation of anti-B(a)PDE-DNA adducts in the LMF by GSTM1-null and some low-activity NER genotypes may be considered as a potential genetic susceptibility factor capable of modulating individual responses to PAH genotoxic exposure and the consequent risk of cancer in coke oven workers.
17. In vivo validation and physiologically based biokinetic modeling of the inhibition of SULT-mediated estragole DNA adduct formation in the liver of male Sprague-Dawley rats by the basil flavonoid nevadensin
NARCIS (Netherlands)
Alhusainy, W.; Paini, A.; Berg, van den J.H.J.; Punt, A.; Scholz, G.; Schilter, B.; Bladeren, van P.J.; Taylor, S.; Adams, T.B.; Rietjens, I.
2013-01-01
ScopeThe present work investigates whether the previous observation that the basil flavonoid nevadensin is able to inhibit sulfotransferase (SULT)-mediated estragole DNA adduct formation in primary rat hepatocytes could be validated in vivo. Methods and resultsEstragole and nevadensin were co-admini
18. JM216-, JM118-, and cisplatin-induced cytotoxicity in relation to platinum-DNA adduct formation, glutathione levels and p53 status in human tumour cell lines with different sensitivities to cisplatin
NARCIS (Netherlands)
Fokkema, E; Groen, HJM; Helder, MN; de Vries, EGE; Meijer, C
2002-01-01
The aim of this study is to establish anti-tumour potency of the new oral platinum drug JM216 and its metabolite JM118 in relation to the platinum (Pt)-DNA adduct formation, glutathione (GSH)-levels, and p53 status in human cancer cell lines with different sensitivities to cisplatin (CDDP). These pa
19. Induction of DNA breakage in X-irradiated nucleoids selectively stripped of nuclear proteins in two mouse lymphoma cell lines differing in radiosensitivity
International Nuclear Information System (INIS)
The role of nuclear proteins in protection of DNA against ionizing radiation and their contribution to the radiation sensitivity was examined by an alkaline version of comet assay in two L5178Y (LY) mouse lymphoma cell lines differing in sensitivity t o ionizing radiation. LY-S cells are twice more sensitive to ionizing radiation than LY-R cells (D0 values of survival curves are 0.5 Gy and 1 Gy, respectively). Sequential removal of nuclear proteins by extraction with NaCl of different concentrations increased the X-ray induced DNA damage in LY-R nucleoids. In contrast, in the radiation sensitive LY-S cell line, depletion of nuclear proteins practically did not affect DNA damage. Although there is no doubt that the main cause of LY-S cells' sensitivity to ionizing radiation is a defect in the repair of double-strand breaks, our data support the concept that nuclear matrix organization may contribute to the cellular susceptibility to DNA damaging agents. (author)
20. Resveratrol-3-O-glucuronide and resveratrol-4’-O-glucuronide reduce DNA strand breakage but not apoptosis in Jurkat T cells treated with camptothecin
Science.gov (United States)
Resveratrol has been reported to inhibit or induce DNA damage depending upon the type of cell and experimental conditions. Dietary resveratrol is present in the body mostly as metabolites and little is known about the activities of these metabolic products. We evaluated physiologically obtainable ...
1. Monitoring of DNA breakage in embryonic stages of the African catfish Clarias gariepinus (Burchell, 1822) after exposure to lead nitrate using alkaline comet assay
NARCIS (Netherlands)
Osman, A.G.M.; Mekkawy, Imam A.; Verreth, J.A.J.; Wuertz, S.; Kloas, W.; Kirschbaum, Frank
2008-01-01
Increasing lead contamination in Egyptian ecosystems and high lead concentrations in food items have raised concern for human health and stimulated studies on monitoring ecotoxicological impact of lead-caused genotoxicity. In this work, the alkaline comet assay was modified for monitoring DNA strand
2. Novel Image Processing Interface to Relate DSB Spatial Distribution from Immunofluorescence Foci Experiments to the State-of-the-Art Models of DNA Breakage
Science.gov (United States)
Ponomarev, A. L.; Cucinotta, F. A.
2004-01-01
A recently developed software (NASARadiationTrackImage) allows a quick and automatic segmentation of foci that indicate spatial localization of specific proteins that are visualized by immunofluorescence. Of interest are the spatial and temporal distribution of foci such as gammaH2AX, a signal of the phosphorylation of a variant of the histone H2A that has been shown to correspond to DSBs, or proteins involved in DSB processing, such as ATM, Rad51, and p53, following exposures of human cells to high charge and energy (HZE) ion irradiation. Experimental data are recorded as sets of two-dimensional images in color with cells and foci of gammaH2AX, ATM, Rad51 or others shown. Different cells, levels of radiation and timing after radiation were recorded. The software allows us to calculate the number of foci per cell, overall intensity of light in foci and their spatial organization. A simple statistical model allows for testing of foci overlap (eclipse). A more complex statistical model previously known as DNAbreak simulates track structure and random chromosome geometry. It has one adjustable parameter corresponding to an average intensity of DSB creation in cubic micrometers of DNA volume per particle track or unit dose. Its limitation is the low-resolution limit both in physical space and DSB's along DNA. It works adequately on the scale of a cell and provides further insights on how the geometry of tracks and DNA affects genomic damage of the cell and subsequent repair. Future developments of the model for the description of the time evolution of DNA damage response proteins, and more robust track structure models will be discussed.
3. Thimerosal-Derived Ethylmercury Is a Mitochondrial Toxin in Human Astrocytes: Possible Role of Fenton Chemistry in the Oxidation and Breakage of mtDNA
Directory of Open Access Journals (Sweden)
Martyn A. Sharpe
2012-01-01
Full Text Available Thimerosal generates ethylmercury in aqueous solution and is widely used as preservative. We have investigated the toxicology of Thimerosal in normal human astrocytes, paying particular attention to mitochondrial function and the generation of specific oxidants. We find that ethylmercury not only inhibits mitochondrial respiration leading to a drop in the steady state membrane potential, but also concurrent with these phenomena increases the formation of superoxide, hydrogen peroxide, and Fenton/Haber-Weiss generated hydroxyl radical. These oxidants increase the levels of cellular aldehyde/ketones. Additionally, we find a five-fold increase in the levels of oxidant damaged mitochondrial DNA bases and increases in the levels of mtDNA nicks and blunt-ended breaks. Highly damaged mitochondria are characterized by having very low membrane potentials, increased superoxide/hydrogen peroxide production, and extensively damaged mtDNA and proteins. These mitochondria appear to have undergone a permeability transition, an observation supported by the five-fold increase in Caspase-3 activity observed after Thimerosal treatment.
4. Replication Bypass of the trans-4-Hydroxynonenal-Derived (6S,8R,11S)-1,N[superscript 2]-Deoxyguanosine DNA Adduct by the Sulfolobus solfataricus DNA Polymerase IV
Energy Technology Data Exchange (ETDEWEB)
Banerjee, Surajit; Christov, Plamen P.; Kozekova, Albena; Rizzo, Carmelo J.; Egli, Martin; Stone, Michael P. (Vanderbilt)
2014-10-02
trans-4-Hydroxynonenal (HNE) is the major peroxidation product of {omega}-6 polyunsaturated fatty acids in vivo. Michael addition of the N{sub 2}-amino group of dGuo to HNE followed by ring closure of N1 onto the aldehyde results in four diastereomeric 1,N{sub 2}-dGuo (1,N{sub 2}-HNE-dGuo) adducts. The (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct was incorporated into the 18-mer templates 5'-d(TCATXGAATCCTTCCCCC)-3' and d(TCACXGAATCCTTCCCCC)-3', where X = (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct. These differed in the identity of the template 5'-neighbor base, which was either Thy or Cyt, respectively. Each of these templates was annealed with either a 13-mer primer 5'-d(GGGGGAAGGATTC)-3' or a 14-mer primer 5'-d(GGGGGAAGGATTCC)-3'. The addition of dNTPs to the 13-mer primer allowed analysis of dNTP insertion opposite to the (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct, whereas the 14-mer primer allowed analysis of dNTP extension past a primed (6S,8R,11S)-HNE-1,N{sub 2}-dGuo:dCyd pair. The Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4) belongs to the Y-family of error-prone polymerases. Replication bypass studies in vitro reveal that this polymerase inserted dNTPs opposite the (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct in a sequence-specific manner. If the template 5'-neighbor base was dCyt, the polymerase inserted primarily dGTP, whereas if the template 5'-neighbor base was dThy, the polymerase inserted primarily dATP. The latter event would predict low levels of Gua {yields} Thy mutations during replication bypass when the template 5'-neighbor base is dThy. When presented with a primed (6S,8R,11S)-HNE-1,N{sub 2}-dGuo:dCyd pair, the polymerase conducted full-length primer extension. Structures for ternary (Dpo4-DNA-dNTP) complexes with all four template-primers were obtained. For the 18-mer:13-mer template-primers in which the polymerase was confronted with the (6S,8R,11S)-HNE-1,N{sub 2}-dGuo adduct, the (6S,8R,11S)-1,N
5. DNA polymerases κ and ζ cooperatively perform mutagenic translesion synthesis of the C8-2'-deoxyguanosine adduct of the dietary mutagen IQ in human cells.
Science.gov (United States)
Bose, Arindam; Pande, Paritosh; Jasti, Vijay P; Millsap, Amy D; Hawkins, Edward K; Rizzo, Carmelo J; Basu, Ashis K
2015-09-30
The roles of translesion synthesis (TLS) DNA polymerases in bypassing the C8-2'-deoxyguanosine adduct (dG-C8-IQ) formed by 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a highly mutagenic and carcinogenic heterocyclic amine found in cooked meats, were investigated. Three plasmid vectors containing the dG-C8-IQ adduct at the G1-, G2- or G3-positions of the NarI site (5'-G1G2CG3CC-3') were replicated in HEK293T cells. Fifty percent of the progeny from the G3 construct were mutants, largely G→T, compared to 18% and 24% from the G1 and G2 constructs, respectively. Mutation frequency (MF) of dG-C8-IQ was reduced by 38-67% upon siRNA knockdown of pol κ, whereas it was increased by 10-24% in pol η knockdown cells. When pol κ and pol ζ were simultaneously knocked down, MF of the G1 and G3 constructs was reduced from 18% and 50%, respectively, to <3%, whereas it was reduced from 24% to <1% in the G2 construct. In vitro TLS using yeast pol ζ showed that it can extend G3*:A pair more efficiently than G3*:C pair, but it is inefficient at nucleotide incorporation opposite dG-C8-IQ. We conclude that pol κ and pol ζ cooperatively carry out the majority of the error-prone TLS of dG-C8-IQ, whereas pol η is involved primarily in its error-free bypass. PMID:26220181
6. Oxidative Damage to Nucleic Acids and Benzo(apyrene-7,8-diol-9,10-epoxide-DNA Adducts and Chromosomal Aberration in Children with Psoriasis Repeatedly Exposed to Crude Coal Tar Ointment and UV Radiation
Directory of Open Access Journals (Sweden)
Lenka Borska
2014-01-01
Full Text Available The paper presents a prospective cohort study. Observed group was formed of children with plaque psoriasis (n=19 treated by Goeckerman therapy (GT. The study describes adverse (side effects associated with application of GT (combined exposure of 3% crude coal tar ointment and UV radiation. After GT we found significantly increased markers of oxidative stress (8-hydroxy-2′-deoxyguanosine, 8-hydroxyguanosine, and 8-hydroxyguanine, significantly increased levels of benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE DNA adducts (BPDE-DNA, and significantly increased levels of total number of chromosomal aberrations in peripheral lymphocytes. We found significant relationship between (1 time of UV exposure and total number of aberrated cells and (2 daily topical application of 3% crude coal tar ointment (% of body surface and level of BPDE-DNA adducts. The findings indicated increased hazard of oxidative stress and genotoxic effects related to the treatment. However, it must be noted that the oxidized guanine species and BPDE-DNA adducts also reflect individual variations in metabolic enzyme activity (different extent of bioactivation of benzo[a]pyrene to BPDE and overall efficiency of DNA/RNA repair system. The study confirmed good effectiveness of the GT (significantly decreased PASI score.
7. DNA adducts, mutant frequencies and mutation spectra in λlacZ transgenic mice treated with N-nitrosodimethylamine
NARCIS (Netherlands)
Souliotis, V.L.; Delft, J.H.M. van; Steenwinkel, M.-J.S.T.; Baan, R.A.; Kyrtopoulos, S.A.
1998-01-01
Groups of λlacZ transgenic mice were treated i.p. with N-nitrosodimethylamine (NDMA) as single doses of 5 mg/kg or 10 mg/kg or as 10 daily doses of 1 mg/kg and changes in DNA N7- or O6-methylguanine or the repair enzyme O6-alkylguanine-DNA alkyltransferase (AGT) were followed for up to 14 days in va
8. Breaking the dogma: PCB-derived semiquinone free radicals do not form covalent adducts with DNA, GSH, and amino acids.
Science.gov (United States)
Wangpradit, Orarat; Rahaman, Asif; Mariappan, S V Santhana; Buettner, Garry R; Robertson, Larry W; Luthe, Gregor
2016-02-01
Covalent bond formations of free radical metabolites with biomolecules like DNA and proteins are thought to constitute a major mechanism of toxicity and carcinogenesis. Glutathione (GSH) is generally accepted as a radical scavenger protecting the cell. In the present study, we investigated a semiquinone radical (SQ(●-)) metabolite of the semivolatile 4-chlorobiphenyl, using electron paramagnetic resonance spectroscopy, and oxygen consumption. Proton nuclear magnetic resonance ((1)H NMR) and liquid chromatography-mass spectrometry (LC-MS) were also employed to elucidate the radical interaction with DNA, amino acids, and GSH. We found that DNA and oligonucleotides stabilized SQ(●-) by electron delocalization in the π-stacking system, resulting in persistent radical intercalated, rather than forming a covalent bond with SQ(●-). This finding was strongly supported by the semiempirical calculation of the semioccupied molecular orbital and the linear combination of the atomic orbitals, indicating 9.8 kcal mol(-1) energy gain. The insertion of SQ(●-) into the DNA strand may result in DNA strand breaks and interruption of DNA replication process or even activate radical mediated secondary reactions. The presence of amino acids resulted in a decrease of the electron paramagnetic resonance (EPR) signal of SQ(●-) and correlated with their isoelectric points. The pH shifts the equilibrium of the dianions of hydroquinone and influenced indirectly the formation of SQ(●-). Similar findings were observed with GSH and Cys. GSH and Cys functioned as indirect radical scavengers; their activities depend on their chemical equilibria with the corresponding quinones, and their further reaction via Michael addition. The generally accepted role of GSH as radical scavenger in biological systems should be reconsidered based upon these findings, questioning the generally accepted view of radical interaction of semiquinones with biologically active compounds, like DNA, amino acids
Directory of Open Access Journals (Sweden)
Sanaa A. El-Benhawy
2016-07-01
Conclusions: Scoring of chromosome aberrations such as breaks, fragments and dicentrics is a reliable method to detect previous exposure to ionizing radiation. This type of monitoring may be used as a biological dosimeter instead of physical dosimetry.8-OHdG is a useful oxidative DNA marker among radiation workers and those exposed to environmental carcinogens.
10. Modulation of adult rat benzo(a)pyrene (BaP) metabolism and DNA adduct formation by neonatal diethylstilbestrol (DES) exposure.
Science.gov (United States)
Ramesh, Aramandla; Inyang, Frank; Knuckles, Maurice E
2004-12-01
This study seeks to elucidate the role of diethylstilbestrol (DES), a synthetic estrogen on benzo(a)pyrene (BaP) metabolism in the male rat reproductive tissues. Offspring of timed-pregnant Sprague-Dawley rats were neonatally treated on days 2, 4, and 6 post-partum with 1.45 micromol/kg of DES. Ten weeks after birth, the adult rats were challenged with radiolabeled benzo(a)pyrene (3H BaP) (10 micromol/kg) and the rats were sacrificed 2 h after BaP exposure. Prostrate, testis, lung, liver, urine and feces samples were collected and extracted using a mixture of H2O, MeOH and CHCl3. The extracts were analyzed by reverse phase HPLC. The concentrations of BaP organic metabolites in DES rats were lower compared to controls (vehicle-treated rats). On the other hand, concentrations of aqueous metabolites were significantly increased in DES treated animals. The toxication to detoxication ratios were significantly decreased in DES rats compared to controls. This trend is also reflected in the decreased concentrations of BaP-DNA adducts in DES rats. Collectively these results suggest that DES is capable of modulating the metabolic pathway of BaP towards detoxification thereby preventing the manifestation of toxicity.
11. Fat content and nitrite-curing influence the formation of oxidation products and NOC-specific DNA adducts during in vitro digestion of meat.
Directory of Open Access Journals (Sweden)
Thomas Van Hecke
Full Text Available The effects of fat content and nitrite-curing of pork were investigated on the formation of cytotoxic and genotoxic lipid oxidation products (malondialdehyde, 4-hydroxy-2-nonenal, volatile simple aldehydes, protein oxidation products (protein carbonyl compounds and NOC-specific DNA adducts (O6-carboxy-methylguanine during in vitro digestion. The formation of these products during digestion is suggested to be responsible for the association between red meat and processed meat consumption and colorectal cancer risk. Digestion of uncured pork to which fat was added (total fat content 5 or 20%, resulted in significantly higher lipid and protein oxidation in the mimicked duodenal and colonic fluids, compared to digestion of pork without added fat (1% fat. A higher fat content also significantly favored the formation of O6-carboxy-methylguanine in the colon. Nitrite-curing of meat resulted in significantly lower lipid and protein oxidation before and after digestion, while an inconsistent effect on the formation of O6-carboxy-methylguanine was observed. The presented results demonstrate that haem-Fe is not solely responsible for oxidation and nitrosation reactions throughout an in vitro digestion approach but its effect is promoted by a higher fat content in meat.
12. Structural and Functional Analysis of Sulfolobus solfataricus Y-Family DNA Polymerase Dpo4-Catalyzed Bypass of the Malondialdehyde−Deoxyguanosine Adduct
Energy Technology Data Exchange (ETDEWEB)
Eoff, Robert L.; Stafford, Jennifer B.; Szekely, Jozsef; Rizzo, Carmelo J.; Egli, Martin; Guengerich, F. Peter; Marnett, Lawrence J.; (Vanderbilt)
2010-01-12
Oxidative stress can induce the formation of reactive electrophiles, such as DNA peroxidation products, e.g., base propenals, and lipid peroxidation products, e.g., malondialdehyde. Base propenals and malondialdehyde react with DNA to form adducts, including 3-(2'-deoxy-{beta}-d-erythro-pentofuranosyl)pyrimido[1,2-{alpha}]purin-10(3H)-one (M{sub 1}dG). When paired opposite cytosine in duplex DNA at physiological pH, M{sub 1}dG undergoes ring opening to form N{sup 2}-(3-oxo-1-propenyl)-dG (N{sup 2}-OPdG). Previous work has shown that M{sub 1}dG is mutagenic in bacteria and mammalian cells and that its mutagenicity in Escherichia coli is dependent on induction of the SOS response, indicating a role for translesion DNA polymerases in the bypass of M{sub 1}dG. To probe the mechanism by which translesion polymerases bypass M{sub 1}dG, kinetic and structural studies were conducted with a model Y-family DNA polymerase, Dpo4 from Sulfolobus solfataricus. The level of steady-state incorporation of dNTPs opposite M{sub 1}dG was reduced 260-2900-fold and exhibited a preference for dATP incorporation. Liquid chromatography-tandem mass spectrometry analysis of the full-length extension products revealed a spectrum of products arising principally by incorporation of dC or dA opposite M{sub 1}dG followed by partial or full-length extension. A greater proportion of -1 deletions were observed when dT was positioned 5' of M{sub 1}dG. Two crystal structures were determined, including a 'type II' frameshift deletion complex and another complex with Dpo4 bound to a dC-M{sub 1}dG pair located in the postinsertion context. Importantly, M{sub 1}dG was in the ring-closed state in both structures, and in the structure with dC opposite M{sub 1}dG, the dC residue moved out of the Dpo4 active site, into the minor groove. The results are consistent with the reported mutagenicity of M{sub 1}dG and illustrate how the lesion may affect replication events.
13. Amifostine Protection Against Mitomycin-induced Chromosomal Breakage in Fanconi Anaemia Lymphocytes
OpenAIRE
Lopes, Miriam T. P.; Salas, Carlos E.; Fernanda S. G. Kehdy; Camelo, Ricardo M.
2008-01-01
Fanconi anaemia (FA) is a rare genetic chromosomal instability syndrome caused by impairment of DNA repair and reactive oxygen species (ROS) imbalance. This disease is also related to bone marrow failure and cancer. Treatment of these complications with radiation and alkylating agents may enhance chromosomal breakage. We have evaluated the effect of amifostine (AMF) on basal and mitomycin C (MMC)-induced chromosomal breakage in FA blood cells using the micronucleus assay. The basal micronucle...
14. DNA双链断裂与同源重组修复的研究进展%Advance in Research of Homologous Recombination Repair in DNA Double Strands Breakage
Institute of Scientific and Technical Information of China (English)
董隽; 张天; 碧秀
2015-01-01
DNA双链断裂（DSB）是细胞受到电离辐射后最严重的DNA损伤，导致细胞凋亡、细胞周期阻滞以及DNA损伤修复。DNA损伤发生后，激活细胞内DNA损伤应答，启动DSB修复通路同源重组（HR）和非同源重组末端连接（NHEJ）。HR修复分为联会前期、联会期和联会后期，以姐妹染色单体为模板，进行无错误修复，是保护基因组完整性的主要机制。对IR导致的DSB HR和NHEJ具有互补关系，G2和S期HR是主要修复方式。HR是肿瘤发病风险、预后指标和治疗靶点，合成致死是HR用于肿瘤靶向治疗的重要机制。本文主要对DSB修复过程中所涉及HR修复通路中的分子机制、合成致死概念及其与NHEJ修复的关系作一综述，并探讨其成为转化医学研究和潜在临床应用的可能性。%DNA double strand breakage (DSB) is the most significantly biological effect when cells are exposed to ionizing radiation (IR) which may result in apoptosis, checkpoint arrest, cellular senescence and DSB repair. DNA damage response (DDR) is activated with induction of DNA damage. The mechanisms involved in DSB repair include homologous recombination (HR) and non-homologous end-joining (NHEJ). HR, a template-dependent and mostly error-free pathway, plays a crucial role in protecting genome fidelity from DSB. It can be divided into three phases including presynaptic, synaptic and postsynaptic phases. For the repair of DSBs caused by IR, HR is mainly restricted in G2 and S phases while NHEJ and HR function complementarily. HR is related to the risk of tumorigenesis, predicts the survival of several kinds of carcinoma and is a novel target of cancer therapy. This article has comprehensively reviewed the progress in understanding of the mechanism of HR repair, its associated factors affecting the fidelity in DSB repair, the concept of synthetic lethality and its association with NHEJ repair. The potential of its clinical application by
15. 32P-postlabeling assay for carcinogen-DNA adducts: description of beta shielding apparatus and semi-automatic spotting and washing devices that facilitate the handling of multiple samples
International Nuclear Information System (INIS)
The utilization of the 32P-postlabeling assay in combination with TLC for the sensitive detection and estimation of aromatic DNA adducts has been increasing. The procedure consists of 32P-labeling of carcinogen-adducted 3'-nucleotides in the DNA digests using γ-32P ATP and polynucleotide kinase, separation of 32P-labeled adducts by TLC, and their detection by autoradiography. During both 32P-labeling and initial phases of TLC, a relatively high amount of γ-32P ATP is handled when 30 samples are processed simultaneously. We describe the design of acrylic shielding apparatus, semi-automatic TLC spotting devices, and devices for development and washing of multiple TLC plates, which not only provide substantial protection from exposure to 32P beta radiation, but also allow quick and easy handling of a large number of samples. Specifically, the equipment includes: (i) a multi-tube carousel rack having 15 wells to hold capless Eppendorf tubes and a rotatable lid with an aperture to access individual tubes; (ii) a pipette shielder; (iii) two semi-automatic spotting devices to apply radioactive solutions to TLC plates; (iv) a multi-plate holder for TLC plates; and (v) a mechanical device for washing multiple TLC plates. Item (i) is small enough to be held in one-hand, vortexed, and centrifuged to mix the solutions in each tube while beta radiation is shielded. Items (iii) to (iv) aid in the automation of the assay. (author)
16. Aflatoxin B1-Associated DNA Adducts Stall S Phase and Stimulate Rad51 foci in Saccharomyces cerevisiae
Directory of Open Access Journals (Sweden)
Michael Fasullo
2010-01-01
17. 18. Adduct detection in human monitoring for carcinogen exposure
Institute of Scientific and Technical Information of China (English)
2001-01-01
@@Determination of the covalently bound products (adducts) of carcinogens with DNA or proteins may be used for the monitoring of exposure to these compounds. Protein adducts are generally stable and are not enzymatically repaired, and the use of these for cxposure monitoring is normally carried out with globin or albumin, because
18. Breakage of Agglomerates: Attrition, Abrasion and Compression
OpenAIRE
Van Laarhoven, B.
2010-01-01
In many industries particulate solids are handled in different forms. When producing particles breakage is an important wanted, in the case of grinding, or unwanted phenomenon. Granules often consist of more than one component and multiple phases. This means that granules are strongly anisotropic and inhomogeneous which makes mechanical characterization difficult, so the strength is difficult to measure. The objective of this thesis is to develop and validate new particle breakage testers fro...
19. Biomarkers of genotoxicity of air pollution (the AULIS project): bulky DNA adducts in subjects with moderate to low exposures to airborne polycyclic aromatic hydrocarbons and their relationship to environmental tobacco smoke and other parameters
DEFF Research Database (Denmark)
Georgiadis, P.; Topinka, J.; Stoikidou, M.;
2001-01-01
The levels of bulky DNA adducts were measured by (32)P-post-labelling in lymphocytes of 194 non-smoking students living in the city of Athens and the region of Halkida, Greece, once in the winter and again in the following summer. Personal exposures to particulate-bound polycyclic aromatic...... tobacco smoke (ETS), namely (i) declared times of exposure to ETS during the 24 h prior to blood donation, (ii) plasma cotinine levels and (iii) chrysene/benzo[g,h,i]perylene ratios in the profile of personal PAH exposure. Furthermore, among the Halkida campus area subjects (but not the remaining subjects...
20. The Impact of Glucuronidation on the Bioactivation and DNA Adduction of the Cooked-Food Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b] pyridine in vivo
Energy Technology Data Exchange (ETDEWEB)
Malfatti, M A; Ubick, E A; Felton, J S
2005-03-31
UDP-glucuronosyltransferases (UGTs) catalyze the glucuronidation of many different chemicals. Glucuronidation is especially important for detoxifying reactive intermediates from metabolic reactions, which otherwise can be biotransformed into highly reactive cytotoxic or carcinogenic species. Detoxification of certain food-borne carcinogenic heterocyclic amines (HAs) is highly dependent on UGT1A-mediated glucuronidation. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most mass abundant carcinogenic HA found in well-done cooked meat, is extensively glucuronidated by UGT1A proteins. In humans, CYP1A2 catalyzed N-hydroxylation and subsequent UGT1A-mediated glucuronidation is a dominant pathway in the metabolism of PhIP. Therefore, changes in glucuronidation rates could significantly alter PhIP metabolism. To determine the importance of UGT1A-mediated glucuronidation in the biotransformation of PhIP, UGT1A proficient Wistar and UGT1A deficient Gunn rats were exposed to a single 100 {micro}g/kg oral dose of [{sup 14}C]-PhIP. Urine was collected over 24 h and the PhIP urinary metabolite profiles were compared between the two strains. After the 24 h exposure, livers and colon were removed and analyzed for DNA adduct formation by accelerator mass spectrometry. Wistar rats produced several PhIP and N-hydroxy-PhIP glucuronides that accounted for {approx}25% of the total amount of recovered urinary metabolites. In the Gunn rats, PhIP and N-hydroxy-PhIP glucuronides were reduced by 68-92%, compared to the Wistar rats, and comprised only 4% of the total amount of recovered urinary metabolites. PhIP-DNA adduct analysis from the Gunn rats revealed a correlation between reduced PhIP and N-hydroxy-PhIP glucuronide levels in the urine and increased hepatic DNA adducts, compared to the Wistar rats. These results indicate that UGT1A-mediated glucuronidation of PhIP and N-hydroxy-PhIP is an important pathway for PhIP detoxification. Failure to form glucuronide conjugates
1. Vitamin C for DNA damage prevention
Energy Technology Data Exchange (ETDEWEB)
Sram, Radim J., E-mail: sram@biomed.cas.cz [Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220 Prague 4 (Czech Republic); Binkova, Blanka; Rossner, Pavel [Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, 14220 Prague 4 (Czech Republic)
2012-05-01
The ability of vitamin C to affect genetic damage was reviewed in human studies that used molecular epidemiology methods, including analysis of DNA adducts, DNA strand breakage (using the Comet assay), oxidative damage measured as levels of 8-oxo-7,8-dihydroxy-2 Prime -deoxyguanosine (8-oxodG), cytogenetic analysis of chromosomal aberrations and micronuclei, and the induction of DNA repair proteins. The protective effect of vitamin C was observed at plasma levels > 50 {mu}mol/l. Vitamin C supplementation decreased the frequency of chromosomal aberrations in groups with insufficient dietary intake who were occupationally exposed to mutagens, and also decreased the sensitivity to mutagens as assessed using the bleomycin assay. High vitamin C levels in plasma decreased the frequency of genomic translocations in groups exposed to ionizing radiation or c-PAHs in polluted air. The frequency of micronuclei was decreased by vitamin C supplementation in smokers challenged with {gamma}-irradiation, and higher vitamin C levels in plasma counteracted the damage induced by air pollution. The prevalence of DNA adducts inversely correlated with vitamin C levels in groups environmentally exposed to high concentrations of c-PAHs. Increased vitamin C levels decreased DNA strand breakage induced by air pollution. Oxidative damage (8-oxodG levels) was decreased by vitamin C supplementation in groups with plasma levels > 50 {mu}mol/l exposed to PM2.5 and c-PAHs. Modulation of DNA repair by vitamin C supplementation was observed both in poorly nourished subjects and in groups with vitamin C plasma levels > 50 {mu}mol/l exposed to higher concentrations of c-PAHs. It is possible that the impact of vitamin C on DNA damage depends both on background values of vitamin C in the individual as well as on the level of exposure to xenobiotics or oxidative stress.
2. Ethanol and 4-methylpyrazole increase DNA adduct formation of furfuryl alcohol in FVB/N wild-type mice and in mice expressing human sulfotransferases 1A1/1A2.
Science.gov (United States)
Sachse, Benjamin; Meinl, Walter; Glatt, Hansruedi; Monien, Bernhard H
2016-03-01
3. Chemical repair activity of free radical scavenger edaravone. Reduction reactions with dGMP hydroxyl radical adducts and suppression of base lesions and AP sites on irradiated plasmid DNA
International Nuclear Information System (INIS)
Reactions of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) with deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts were investigated by pulse radiolysis technique. Edaravone was found to reduce the dGMP hydroxyl radical adducts through electron transfer reactions. The rate constants of the reactions were greater than 4 × 108 dm3 mol-1 s-1 and similar to those of the reactions of ascorbic acid, which is a representative antioxidant. Yields of single-strand breaks, base lesions, and abasic sites produced in pUC18 plasmid DNA by gamma ray irradiation in the presence of low concentrations (10–1000 μmol dm-3) of edaravone were also quantified, and the chemical repair activity of edaravone was estimated by a method recently developed by the authors. By comparing suppression efficiencies to the induction of each DNA lesion, it was found that base lesions and abasic sites were suppressed by the chemical repair activity of edaravone, although the suppression of single-strand breaks was not very effective. This phenomenon was attributed to the chemical repair activity of edaravone toward base lesions and abasic sites. However, the chemical repair activity of edaravone for base lesions was lower than that of ascorbic acid. (author)
4. Indole-3-carbinol induces a rat liver glutathione transferase subunit (Yc2) with high activity toward aflatoxin B1 exo-epoxide. Association with reduced levels of hepatic aflatoxin-DNA adducts in vivo.
Science.gov (United States)
Stresser, D M; Williams, D E; McLellan, L I; Harris, T M; Bailey, G S
1994-01-01
Aflatoxin B1 (AFB1), a metabolite of the grain mold Aspergillus flavus, is a potent hepatocarcinogen and widespread contaminant of human food supplies. AFB1-induced tumors or preneoplastic lesions in experimental animals can be inhibited by cotreatment with several compounds, including indole-3-carbinol (I3C), a component of cruciferous vegetables, and the well-known Ah receptor agonist beta-naphthoflavone (BNF). This study examines the influence of these two agents on the AFB1-glutathione detoxication pathway and AFB1-DNA adduction in rat liver. After 7 days of feeding approximately equally inhibitory doses of I3C (0.2%) or BNF (0.04%) alone or in combination, male Fischer 344 rats were administered [3H]AFB1 (0.5 mg/kg, 480 microCi/kg) intraperitoneally and killed 2 hr later. All three experimental diets inhibited in vivo AFB1-DNA adduction (BNF, 46%; I3C, 68%; combined, 51%). Based on Western blots using antibodies specific for the glutathione S-transferase (GST), subunit Yc2 (subunit 10) appeared to be substantially elevated by the diets containing I3C (I3C diet, 4.0-fold increase in band density; combined diet, 2.8-fold). The BNF diet appeared to elevate Yc2 to a lesser extent (2.2-fold increase in band density).(ABSTRACT TRUNCATED AT 250 WORDS)
5. The breakage of nanopore in AAO template
Science.gov (United States)
Jia, X. R.; Wang, H.; Zhen, Y.
2016-07-01
In the present work, AAO template is fabricated in oxalic acid solution under a constant voltage by several steps. By the Bernoulli principle, the pressure on the wall of hole increases which lead to the breakage of nanopore as a result of the reducing effective migration rate of Al3+. The quantity of the breakage of nanopore rises with the increase of the concentration of Al3+. Further, nanopore is closed by oxide due to the decrease of effective migration rate of Al3+. Finally, a “nanoflower-like” shape can be observed in experiments.
6. Breakage of Agglomerates: Attrition, Abrasion and Compression
NARCIS (Netherlands)
Van Laarhoven, B.
2010-01-01
In many industries particulate solids are handled in different forms. When producing particles breakage is an important wanted, in the case of grinding, or unwanted phenomenon. Granules often consist of more than one component and multiple phases. This means that granules are strongly anisotropic an
7. Sustained induction of cytochrome P4501A1 in human hepatoma cells by co-exposure to benzo[a]pyrene and 7H-dibenzo[c,g]carbazole underlies the synergistic effects on DNA adduct formation
Energy Technology Data Exchange (ETDEWEB)
Gábelová, Alena, E-mail: alena.gabelova@savba.sk [Cancer Research Institute, Slovak Academy of Sciences, Vlárska 7, 833 91 Bratislava (Slovakia); Poláková, Veronika [Cancer Research Institute, Slovak Academy of Sciences, Vlárska 7, 833 91 Bratislava (Slovakia); Prochazka, Gabriela [Department of Biosciences and Nutrition, Karolinska Institute, Novum, SE-141 83 Huddinge (Sweden); Department of Medical Epidemiology and Biostatistics, Karolinska Institute, SE-171 77 Stockholm (Sweden); Kretová, Miroslava; Poloncová, Katarína; Regendová, Eva; Luciaková, Katarína [Cancer Research Institute, Slovak Academy of Sciences, Vlárska 7, 833 91 Bratislava (Slovakia); Segerbäck, Dan [Department of Biosciences and Nutrition, Karolinska Institute, Novum, SE-141 83 Huddinge (Sweden)
2013-08-15
To gain a deeper insight into the potential interactions between individual aromatic hydrocarbons in a mixture, several benzo[a]pyrene (B[a]P) and 7H-dibenzo[c,g]carbazole (DBC) binary mixtures were studied. The biological activity of the binary mixtures was investigated in the HepG2 and WB-F344 liver cell lines and the Chinese hamster V79 cell line that stably expresses the human cytochrome P4501A1 (hCYP1A1). In the V79 cells, binary mixtures, in contrast to individual carcinogens, caused a significant decrease in the levels of micronuclei, DNA adducts and gene mutations, but not in cell survival. Similarly, a lower frequency of micronuclei and levels of DNA adducts were found in rat liver WB-F344 cells treated with a binary mixture, regardless of the exposure time. The observed antagonism between B[a]P and DBC may be due to an inhibition of Cyp1a1 expression because cells exposed to B[a]P:DBC showed a decrease in Cyp1a1 mRNA levels. In human liver HepG2 cells exposed to binary mixtures for 2 h, a reduction in micronuclei frequency was also found. However, after a 24 h treatment, synergism between B[a]P and DBC was determined based on DNA adduct formation. Accordingly, the up-regulation of CYP1A1 expression was detected in HepG2 cells exposed to B[a]P:DBC. Our results show significant differences in the response of human and rat cells to B[a]P:DBC mixtures and stress the need to use multiple experimental systems when evaluating the potential risk of environmental pollutants. Our data also indicate that an increased expression of CYP1A1 results in a synergistic effect of B[a]P and DBC in human cells. As humans are exposed to a plethora of noxious chemicals, our results have important implications for human carcinogenesis. - Highlights: • B[a]P:DBC mixtures were less genotoxic in V79MZh1A1 cells than B[a]P and DBC alone. • An antagonism between B[a]P and DBC was determined in rat liver WB-F344 cells. • The inhibition of CYP1a1 expression by B[a]P:DBC mixture
8. Mutagenicity, stable DNA adducts, and abasic sites induced in Salmonella by phenanthro[3,4-b]- and phenanthro[4,3-b]thiophenes, sulfur analogs of benzo[c]phenanthrene
Energy Technology Data Exchange (ETDEWEB)
Swartz, Carol D. [Department of Environmental Science and Engineering, University of North Carolina, Chapel Hill, NC 27599 (United States); King, Leon C.; Nesnow, Stephen [Environmental Carcinogenesis Division, US Environmental Protection Agency, Research Triangle Park, NC, 27711 (United States); Umbach, David M. [Biostatistics Branch, National Institute of Environmental Health Sciences, National Institutes of Health, DHHS, Research Triangle Park, NC 27709 (United States); Kumar, Subodh [Environmental Toxicology and Chemistry Laboratory, Great Lakes Center, State University of New York College at Buffalo, Buffalo, NY 14222 (United States); DeMarini, David M. [Environmental Carcinogenesis Division, US Environmental Protection Agency, Research Triangle Park, NC, 27711 (United States)], E-mail: demarini.david@epa.gov
2009-02-10
Sulfur-containing polycyclic aromatic hydrocarbons (thia-PAHs or thiaarenes) are common constituents of air pollution and cigarette smoke, but only a few have been studied for health effects. We evaluated the mutagenicity in Salmonella TA98, TA100, and TA104 of two sulfur-containing derivatives of benzo[c]phenanthrene, phenanthro[3,4-b]thiophene (P[3,4-b]T), and phenanthro[4,3-b]thiophene (P[4,3-b]T) as well as their dihydrodiol and sulfone derivatives. In addition, we assessed levels of stable DNA adducts (by {sup 32}P-postlabeling) as well as abasic sites (by an aldehydic-site assay) produced by six of these compounds in TA100. P[3,4-b]T and its 6,7- and 8,9-diols, P[3,4-b]T sulfone, P[4,3-b]T, and its 8,9-diol were mutagenic in TA100. P[3,4-b]T sulfone, the most potent mutagen, was approximately twice as potent as benzo[a]pyrene in both TA98 and TA100. Benzo-ring dihydrodiols were much more potent than K-region dihydrodiols, which had little or no mutagenic activity in any strain. P[3,4-b]T sulfone produced abasic sites and not stable DNA adducts; the other five compounds examined, B[c]P, B[c]P 3,4-diol, P[3,4-b]T, P[3,4-b]T 8,9-diol, and P[4,3-b]T 8,9-diol, produced only stable DNA adducts. P[3,4-b]T sulfone was the only compound that produced significant levels of frameshift mutagenicity and induced mutations primarily at GC sites. In contrast, B[c]P, its 3,4-diol, and the 8,9 diols of the phenanthrothiophenes induced mutations primarily at AT sites. P[3,4-b]T was not mutagenic in TA104, whereas P[3,4-b]T sulfone was. The two isomeric forms (P[3,4-b]T and P[4,3-b]T) are apparently activated differently, with the latter, but not the former, involving a diol pathway. This study is the first illustrating the potential importance of abasic sites in the mutagenicity of thia-PAHs.
9. Randomized Terminal Linker-dependent PCR: A Versatile and Sensitive Method for Detection of DNA Damage
Institute of Scientific and Technical Information of China (English)
2002-01-01
Objective To design and develop a novel, sensitive and versatile method for in vivo foot printing and studies of DNA damage, such as DNA adducts and strand breaks. Methods Starting with mammalian genomic DNA, single-stranded products were made by repeated primer extension, these products were ligated to a double-stranded linker having a randomized 3′ overhang, and used for PCR.DNA breaks in p53 gene produced by restriction endonuclease AfaI were detected by using this new method followed by Southern hybridization with DIG-labeled probe. Results This randomized terminal linker-dependent PCR (RDPCR) method could generate band signals many-fold stronger than conventional ligation-mediated PCR (LMPCR), and it was more rapid, convenient and accurate than the terminal transferase-dependent PCR (TDPCR). Conclusion DNA strand breakage can be detected sensitively in the gene level by RDPCR. Any lesion that blocks primer extension should be detectable.
10. Cranial MRI in the Nijmegen breakage syndrome
Energy Technology Data Exchange (ETDEWEB)
Bekiesinska-Figatowska, M. [Department of Diagnostic Imaging, Central Railway Hospital, Warsaw (Poland); Chrzanowska, K.H.; Krajewska-Walasek, M. [Department of Medical Genetics, Children' s Memorial Health Institute, Warsaw (Poland); Sikorska, J.; Walecki, J. [Department of Diagnostic Imaging, Medical Centre for Postgraduate Education, Warsaw (Poland); Jozwiak, S. [Department of Neurology, Children' s Memorial Health Institute, Warsaw (Poland); Kleijer, W.J. [Department of Clinical Genetics, Erasmus University Rotterdam (Netherlands)
2000-01-01
We present the results of MRI examinations in ten patients with documented Nijmegen breakage syndrome (NBS), aged 1.75-19 years. T1-, Proton-Density- and T2-weighted spin-echo sequences were performed in three planes. All patients showed microcephaly with decreased size of the frontal lobes and narrow frontal horns. In four patients agenesis of the posterior part of the corpus callosum was found, with colpocephaly and temporal horns dilatation. In one patient callosal hypoplasia was accompanied by abnormal cerebrospinal fluid spaces and wide cerebral cortex, suspicious of pachygyria. Sinusitis was present in all ten patients, as a result of primary immunodeficiency. As in ataxia teleangiectasia and other breakage syndromes, patients with NBS show an inherited susceptibility to malignancy and hypersensitivity to X- and {gamma}-radiation. CT is therefore contraindicated in these patients and MRI should be the method of choice for diagnostic imaging. (orig.)
11. Correlation of {sup 32}P-postlabelling-detection of DNA adducts in mouse skin in vivo with the polycyclic aromatic compound content and mutagenicity in Salmonella typhimurium of a range of oil products
Energy Technology Data Exchange (ETDEWEB)
Booth, E.D.; Loose, R.W.; Watson, W.P. [Toxicology Department, Shell International Chemicals B.V., Amsterdam (Netherlands); Brandt, H.C.A. [Product Development Department, Shell International Oil Products B.V., Amsterdam (Netherlands)
1998-07-01
The in vivo genotoxic activities in mouse skin of the dimethyl sulphoxide (DMSO) extracts of a range of oil products [residual aromatic extract; untreated heavy paraffinic distillate aromatic extract; mildly refined light naphthenic base oil; bitumen (vacuum residue); high viscosity index base oil obtained by catalytic hydrogenation] were evaluated by {sup 32}P-postlabelling DNA analysis. The results of quantitative {sup 32}P-postlabelling analyses of epidermal DNA from mice treated with the DMSO extracts showed linear relationships with the total polycyclic aromatic compound (PAC) contents, determined by the Institute of Petroleum method IP 346 and also the 3-6 ring PAC contents, measured by on-line liquid-liquid extraction using flow injection analysis. The {sup 32}P-postlabelling data also showed a linear relationship with the mutagenicity indices of these oil products determined in S. typhimurium TA98 using the modified Ames Salmonella microsome test. The in vivo genotoxicity of the DMSO extracts from the oil products was low, judged by {sup 32}P-postlabelling analysis of DNA adducts measured in epidermal DNA of treated mouse skin, and ranging from 2 to 723 attomole/{mu}g DNA per mg oil product. The in vivo {sup 32}P-postlabelling data from this study are consistent with these materials expressing low genotoxicity in mouse skin in vivo. The DMSO extraction procedure coupled with {sup 32}P-postlabelling DNA analysis is useful for ranking the relative genotoxic potency in vivo of a wide range of oil products. In general the trend observed is similar to rankings based on physicochemical measurements of total PAC contents or 3-6 ring PAC contents of the oil products. (orig.) With 4 figs., 1 tab., 44 refs.
12. Correlation of 32P-postlabelling-detection of DNA adducts in mouse skin in vivo with the polycyclic aromatic compound content and mutagenicity in Salmonella typhimurium of a range of oil products
International Nuclear Information System (INIS)
The in vivo genotoxic activities in mouse skin of the dimethyl sulphoxide (DMSO) extracts of a range of oil products [residual aromatic extract; untreated heavy paraffinic distillate aromatic extract; mildly refined light naphthenic base oil; bitumen (vacuum residue); high viscosity index base oil obtained by catalytic hydrogenation] were evaluated by 32P-postlabelling DNA analysis. The results of quantitative 32P-postlabelling analyses of epidermal DNA from mice treated with the DMSO extracts showed linear relationships with the total polycyclic aromatic compound (PAC) contents, determined by the Institute of Petroleum method IP 346 and also the 3-6 ring PAC contents, measured by on-line liquid-liquid extraction using flow injection analysis. The 32P-postlabelling data also showed a linear relationship with the mutagenicity indices of these oil products determined in S. typhimurium TA98 using the modified Ames Salmonella microsome test. The in vivo genotoxicity of the DMSO extracts from the oil products was low, judged by 32P-postlabelling analysis of DNA adducts measured in epidermal DNA of treated mouse skin, and ranging from 2 to 723 attomole/μg DNA per mg oil product. The in vivo 32P-postlabelling data from this study are consistent with these materials expressing low genotoxicity in mouse skin in vivo. The DMSO extraction procedure coupled with 32P-postlabelling DNA analysis is useful for ranking the relative genotoxic potency in vivo of a wide range of oil products. In general the trend observed is similar to rankings based on physicochemical measurements of total PAC contents or 3-6 ring PAC contents of the oil products. (orig.)
13. Environmental and chemotherapeutic agents induce breakage at genes involved in leukemia-causing gene rearrangements in human hematopoietic stem/progenitor cells
Energy Technology Data Exchange (ETDEWEB)
Thys, Ryan G., E-mail: rthys@wakehealth.edu [Department of Cancer Biology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1016 (United States); Lehman, Christine E., E-mail: clehman@wakehealth.edu [Department of Cancer Biology, Wake Forest School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1016 (United States); Pierce, Levi C.T., E-mail: Levipierce@gmail.com [Human Longevity, Inc., San Diego, California 92121 (United States); Wang, Yuh-Hwa, E-mail: yw4b@virginia.edu [Department of Biochemistry and Molecular Genetics, University of Virginia, 1340 Jefferson Park Avenue, Charlottesville, VA 22908-0733 (United States)
2015-09-15
Highlights: • Environmental/chemotherapeutic agents cause DNA breakage in MLL and CBFB in HSPCs. • Diethylnitrosamine-induced DNA breakage at MLL and CBFB shown for the first time. • Chemical-induced DNA breakage occurs at topoisomerase II cleavage sites. • Chemical-induced DNA breaks display a pattern similar to those in leukemia patients. • Long-term exposures suggested to generate DNA breakage at leukemia-related genes. - Abstract: Hematopoietic stem and progenitor cells (HSPCs) give rise to all of the cells that make up the hematopoietic system in the human body, making their stability and resilience especially important. Damage to these cells can severely impact cell development and has the potential to cause diseases, such as leukemia. Leukemia-causing chromosomal rearrangements have largely been studied in the context of radiation exposure and are formed by a multi-step process, including an initial DNA breakage and fusion of the free DNA ends. However, the mechanism for DNA breakage in patients without previous radiation exposure is unclear. Here, we investigate the role of non-cytotoxic levels of environmental factors, benzene, and diethylnitrosamine (DEN), and chemotherapeutic agents, etoposide, and doxorubicin, in generating DNA breakage at the patient breakpoint hotspots of the MLL and CBFB genes in human HSPCs. These conditions represent exposure to chemicals encountered daily or residual doses from chemotherapeutic drugs. Exposure of HSPCs to non-cytotoxic levels of environmental chemicals or chemotherapeutic agents causes DNA breakage at preferential sites in the human genome, including the leukemia-related genes MLL and CBFB. Though benzene, etoposide, and doxorubicin have previously been linked to leukemia formation, this is the first study to demonstrate a role for DEN in the generation of DNA breakage at leukemia-specific sites. These chemical-induced DNA breakpoints coincide with sites of predicted topoisomerase II cleavage. The
14. Environmental and chemotherapeutic agents induce breakage at genes involved in leukemia-causing gene rearrangements in human hematopoietic stem/progenitor cells
International Nuclear Information System (INIS)
Highlights: • Environmental/chemotherapeutic agents cause DNA breakage in MLL and CBFB in HSPCs. • Diethylnitrosamine-induced DNA breakage at MLL and CBFB shown for the first time. • Chemical-induced DNA breakage occurs at topoisomerase II cleavage sites. • Chemical-induced DNA breaks display a pattern similar to those in leukemia patients. • Long-term exposures suggested to generate DNA breakage at leukemia-related genes. - Abstract: Hematopoietic stem and progenitor cells (HSPCs) give rise to all of the cells that make up the hematopoietic system in the human body, making their stability and resilience especially important. Damage to these cells can severely impact cell development and has the potential to cause diseases, such as leukemia. Leukemia-causing chromosomal rearrangements have largely been studied in the context of radiation exposure and are formed by a multi-step process, including an initial DNA breakage and fusion of the free DNA ends. However, the mechanism for DNA breakage in patients without previous radiation exposure is unclear. Here, we investigate the role of non-cytotoxic levels of environmental factors, benzene, and diethylnitrosamine (DEN), and chemotherapeutic agents, etoposide, and doxorubicin, in generating DNA breakage at the patient breakpoint hotspots of the MLL and CBFB genes in human HSPCs. These conditions represent exposure to chemicals encountered daily or residual doses from chemotherapeutic drugs. Exposure of HSPCs to non-cytotoxic levels of environmental chemicals or chemotherapeutic agents causes DNA breakage at preferential sites in the human genome, including the leukemia-related genes MLL and CBFB. Though benzene, etoposide, and doxorubicin have previously been linked to leukemia formation, this is the first study to demonstrate a role for DEN in the generation of DNA breakage at leukemia-specific sites. These chemical-induced DNA breakpoints coincide with sites of predicted topoisomerase II cleavage. The
15. 2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline-induced DNA adduct formation and mutagenesis in DNA repair-deficient Chinese hamster ovary cells expressing human cytochrome P4501A1 and rapid or slow acetylator N-acetyltransferase 2.
Science.gov (United States)
Bendaly, Jean; Zhao, Shuang; Neale, Jason R; Metry, Kristin J; Doll, Mark A; States, J Christopher; Pierce, William M; Hein, David W
2007-07-01
2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MeIQx) is one of the most potent and abundant mutagens in the western diet. Bioactivation includes N-hydroxylation catalyzed by cytochrome P450s followed by O-acetylation catalyzed by N-acetyltransferase 2 (NAT2). In humans, NAT2*4 allele is associated with rapid acetylator phenotype, whereas NAT2*5B allele is associated with slow acetylator phenotype. We hypothesized that rapid acetylator phenotype predisposes humans to DNA damage and mutagenesis from MeIQx. Nucleotide excision repair-deficient Chinese hamster ovary cells were constructed by stable transfection of human cytochrome P4501A1 (CYP1A1) and a single copy of either NAT2*4 (rapid acetylator) or NAT2*5B (slow acetylator) alleles. CYP1A1 and NAT2 catalytic activities were undetectable in untransfected Chinese hamster ovary cell lines. CYP1A1 activity did not differ significantly (P > 0.05) among the CYP1A1-transfected cell lines. Cells transfected with NAT2*4 had 20-fold significantly higher levels of sulfamethazine N-acetyltransferase (P = 0.0001) and 6-fold higher levels of N-hydroxy-MeIQx O-acetyltransferase (P = 0.0093) catalytic activity than cells transfected with NAT2*5B. Only cells transfected with both CYP1A1 and NAT2*4 showed concentration-dependent cytotoxicity and hypoxanthine phosphoribosyl transferase mutagenesis following MeIQx treatment. Deoxyguanosine-C8-MeIQx was the primary DNA adduct formed and levels were dose dependent in each cell line and in the following order: untransfected < transfected with CYP1A1 < transfected with CYP1A1 and NAT2*5B < transfected with CYP1A1 and NAT2*4. MeIQx DNA adduct levels were significantly higher (P < 0.001) in CYP1A1/NAT2*4 than CYP1A1/NAT2*5B cells at all concentrations of MeIQx tested. MeIQx-induced DNA adduct levels correlated very highly (r2 = 0.88) with MeIQx-induced mutants. These results strongly support extrahepatic activation of MeIQx by CYP1A1 and a robust effect of human NAT2 genetic polymorphism
16. Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse
Energy Technology Data Exchange (ETDEWEB)
Siddens, Lisbeth K. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Bunde, Kristi L. [College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331 (United States); Harper, Tod A. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States); Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); McQuistan, Tammie J. [Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States); Löhr, Christiane V. [Environmental Health Sciences Center, Oregon State University, Corvallis, OR 97331 (United States); College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331 (United States); Bramer, Lisa M. [Applied Statistics and Computational Modeling, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Waters, Katrina M. [Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Tilton, Susan C. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Krueger, Sharon K. [Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331 (United States); Superfund Research Center, Oregon State University, Corvallis, OR 97331 (United States); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States); and others
2015-09-01
FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8 h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8 h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4 h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8 h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. - Highlights: • Cyp1b1 null mice exhibit lower skin cancer sensitivity to DBC but not BaP or CTE. • Cyp1b1 expression impacts expression of other PAH metabolizing enzymes. • cis/trans-DBCDE-dA ratio significantly higher in the skin than the spleen, lung or liver • Potency of DBC and CTE in mouse skin is higher than predicted by RPFs.
17. Cytochrome P450 1b1 in polycyclic aromatic hydrocarbon (PAH)-induced skin carcinogenesis: Tumorigenicity of individual PAHs and coal-tar extract, DNA adduction and expression of select genes in the Cyp1b1 knockout mouse.
Science.gov (United States)
Siddens, Lisbeth K; Bunde, Kristi L; Harper, Tod A; McQuistan, Tammie J; Löhr, Christiane V; Bramer, Lisa M; Waters, Katrina M; Tilton, Susan C; Krueger, Sharon K; Williams, David E; Baird, William M
2015-09-01
FVB/N mice wild-type, heterozygous or null for Cyp 1b1 were used in a two-stage skin tumor study comparing PAH, benzo[a]pyrene (BaP), dibenzo[def,p]chrysene (DBC), and coal tar extract (CTE, SRM 1597a). Following 20 weeks of promotion with TPA the Cyp 1b1 null mice, initiated with DBC, exhibited reductions in incidence, multiplicity, and progression. None of these effects were observed with BaP or CTE. The mechanism of Cyp 1b1-dependent alteration of DBC skin carcinogenesis was further investigated by determining expression of select genes in skin from DBC-treated mice 2, 4 and 8h post-initiation. A significant reduction in levels of Cyp 1a1, Nqo1 at 8h and Akr 1c14 mRNA was observed in Cyp 1b1 null (but not wt or het) mice, whereas no impact was observed in Gst a1, Nqo 1 at 2 and 4h or Akr 1c19 at any time point. Cyp 1b1 mRNA was not elevated by DBC. The major covalent DNA adducts, dibenzo[def,p]chrysene-(±)-11,12-dihydrodiol-cis and trans-13,14-epoxide-deoxyadenosine (DBCDE-dA) were quantified by UHPLC-MS/MS 8h post-initiation. Loss of Cyp1 b1 expression reduced DBCDE-dA adducts in the skin but not to a statistically significant degree. The ratio of cis- to trans-DBCDE-dA adducts was higher in the skin than other target tissues such as the spleen, lung and liver (oral dosing). These results document that Cyp 1b1 plays a significant role in bioactivation and carcinogenesis of DBC in a two-stage mouse skin tumor model and that loss of Cyp 1b1 has little impact on tumor response with BaP or CTE as initiators. PMID:26049101
18. Collision of Trapped Topoisomerase 2 with Transcription and Replication: Generation and Repair of DNA Double-Strand Breaks with 5′ Adducts
OpenAIRE
Hong Yan; Margaret Tammaro; Shuren Liao
2016-01-01
Topoisomerase 2 (Top2) is an essential enzyme responsible for manipulating DNA topology during replication, transcription, chromosome organization and chromosome segregation. It acts by nicking both strands of DNA and then passes another DNA molecule through the break. The 5′ end of each nick is covalently linked to the tyrosine in the active center of each of the two subunits of Top2 (Top2cc). In this configuration, the two sides of the nicked DNA are held together by the strong protein-prot...
19. Implication of the E. coli K12 uvrA and recA genes in the repair of 8-methoxypsoralen-induced mono adducts and crosslinks on plasmid DNA; Implicacion de los genes uvrA de E. coli K12 en la reparacion de monoaductos y entrecruzamien tos inducidos en DNA plasmidico por 8-metoxipso raleno mas luz ultravioleta A
Energy Technology Data Exchange (ETDEWEB)
Paramio, J.M.; Bauluz, C.; Vidania, R. de
1986-07-01
Genotoxicity of psoralen damages on plasmid DNA has been studied. pBR322 DNA was randomly modified with several concentrations of 8-methoxypsoralen plus 365 nm-UV light. After transformation into E. coli strains (wild-type, uvrA and recA) plasmid survival and mutagenesis were analyzed. To study the influence of the SOS response on plasmid recovery, preirradiation of the cells was performed. In absence of cell preirradiation, crosslinks were not repaired in any strain. Mono adducts were also lethal but in part removed by the excision-repair pathway. Preirradiation of the cells significantly. increased plasmid recovery in recA+ celia. In uvrA- only the mutagenic pathway seemed to be involved in the repair of the damaged DNA. Wild type strain showed the highest increase in plasmid survival, involving the repair of mono adducts and some fraction of crosslinks mainly through an error-free repair pathway. This suggests an enhancement of the excision repair promoted by the induction of SOS functions. (Author) 32 refs.
20. THEORIES OF ROCK BREAKAGE WITH EXPLOSIVES
Directory of Open Access Journals (Sweden)
Vinko Škrlec
2014-12-01
Full Text Available The prediction and observation of the nature and dimensions of damaged zones in the surrounding rock mass and understanding the mechanisms of fracturing and crushing of the rock mass with explosives is one of the most important parameters in blasting design in order to obtain preferred granulation and reduce damaging effects of blasting on the environment. An overview of existing rock breakage theories with the energy released by the detonation of explosives is given in this paper (the paper is published in Croatian.
1. Acetaldehyde Adducts in Alcoholic Liver Disease
Directory of Open Access Journals (Sweden)
Mashiko Setshedi
2010-01-01
Full Text Available Chronic alcohol abuse causes liver disease that progresses from simple steatosis through stages of steatohepatitis, fibrosis, cirrhosis, and eventually hepatic failure. In addition, chronic alcoholic liver disease (ALD, with or without cirrhosis, increases risk for hepatocellular carcinoma (HCC. Acetaldehyde, a major toxic metabolite, is one of the principal culprits mediating fibrogenic and mutagenic effects of alcohol in the liver. Mechanistically, acetaldehyde promotes adduct formation, leading to functional impairments of key proteins, including enzymes, as well as DNA damage, which promotes mutagenesis. Why certain individuals who heavily abuse alcohol, develop HCC (7.2–15% versus cirrhosis (15–20% is not known, but genetics and co-existing viral infection are considered pathogenic factors. Moreover, adverse effects of acetaldehyde on the cardiovascular and hematologic systems leading to ischemia, heart failure, and coagulation disorders, can exacerbate hepatic injury and increase risk for liver failure. Herein, we review the role of acetaldehyde adducts in the pathogenesis of chronic ALD and HCC.
2. Destabilized SMC5/6 complex leads to chromosome breakage syndrome with severe lung disease.
Science.gov (United States)
van der Crabben, Saskia N; Hennus, Marije P; McGregor, Grant A; Ritter, Deborah I; Nagamani, Sandesh C S; Wells, Owen S; Harakalova, Magdalena; Chinn, Ivan K; Alt, Aaron; Vondrova, Lucie; Hochstenbach, Ron; van Montfrans, Joris M; Terheggen-Lagro, Suzanne W; van Lieshout, Stef; van Roosmalen, Markus J; Renkens, Ivo; Duran, Karen; Nijman, Isaac J; Kloosterman, Wigard P; Hennekam, Eric; Orange, Jordan S; van Hasselt, Peter M; Wheeler, David A; Palecek, Jan J; Lehmann, Alan R; Oliver, Antony W; Pearl, Laurence H; Plon, Sharon E; Murray, Johanne M; van Haaften, Gijs
2016-08-01
The structural maintenance of chromosomes (SMC) family of proteins supports mitotic proliferation, meiosis, and DNA repair to control genomic stability. Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. Here, we have identified a chromosome breakage syndrome associated with severe lung disease in early childhood. Four children from two unrelated kindreds died of severe pulmonary disease during infancy following viral pneumonia with evidence of combined T and B cell immunodeficiency. Whole exome sequencing revealed biallelic missense mutations in the NSMCE3 (also known as NDNL2) gene, which encodes a subunit of the SMC5/6 complex that is essential for DNA damage response and chromosome segregation. The NSMCE3 mutations disrupted interactions within the SMC5/6 complex, leading to destabilization of the complex. Patient cells showed chromosome rearrangements, micronuclei, sensitivity to replication stress and DNA damage, and defective homologous recombination. This work associates missense mutations in NSMCE3 with an autosomal recessive chromosome breakage syndrome that leads to defective T and B cell function and acute respiratory distress syndrome in early childhood. PMID:27427983
3. Assessment of three classes of DNA adducts in human placentas from smoking and non-snoking women in the Czech Republic
Science.gov (United States)
Three classes of DNA damage were assessed in human placentas collected (2000-2004) from 51 women living in the Teplice region of the Czech Republic, a mining area considered to have some of the worst environmental pollution in Europe in the 1980s. Polycyclic aromatic hydrocarbon ...
4. A physiologically based in silico model for trans-2-hexenal detoxicifcation and DNA adduct formation in human including interindividual variation indicates efficient detoxification and a negligible genotoxicity risk
NARCIS (Netherlands)
Kiwamoto, R.; Spenkelink, A.; Rietjens, I.M.C.M.; Punt, A.
2013-01-01
A number of a,ß-unsaturated aldehydes are present in food both as natural constituents and as flavouring agents. Their reaction with DNA due to their electrophilic a,ß-unsaturated aldehyde moiety may result in genotoxicity as observed in some in vitro models, thereby raising a safety concern. A ques
5. Collision of Trapped Topoisomerase 2 with Transcription and Replication: Generation and Repair of DNA Double-Strand Breaks with 5′ Adducts
Directory of Open Access Journals (Sweden)
Hong Yan
2016-07-01
Full Text Available Topoisomerase 2 (Top2 is an essential enzyme responsible for manipulating DNA topology during replication, transcription, chromosome organization and chromosome segregation. It acts by nicking both strands of DNA and then passes another DNA molecule through the break. The 5′ end of each nick is covalently linked to the tyrosine in the active center of each of the two subunits of Top2 (Top2cc. In this configuration, the two sides of the nicked DNA are held together by the strong protein-protein interactions between the two subunits of Top2, allowing the nicks to be faithfully resealed in situ. Top2ccs are normally transient, but can be trapped by cancer drugs, such as etoposide, and subsequently processed into DSBs in cells. If not properly repaired, these DSBs would lead to genome instability and cell death. Here, I review the current understanding of the mechanisms by which DSBs are induced by etoposide, the unique features of such DSBs and how they are repaired. Implications for the improvement of cancer therapy will be discussed.
6. Collision of Trapped Topoisomerase 2 with Transcription and Replication: Generation and Repair of DNA Double-Strand Breaks with 5' Adducts.
Science.gov (United States)
Yan, Hong; Tammaro, Margaret; Liao, Shuren
2016-01-01
Topoisomerase 2 (Top2) is an essential enzyme responsible for manipulating DNA topology during replication, transcription, chromosome organization and chromosome segregation. It acts by nicking both strands of DNA and then passes another DNA molecule through the break. The 5' end of each nick is covalently linked to the tyrosine in the active center of each of the two subunits of Top2 (Top2cc). In this configuration, the two sides of the nicked DNA are held together by the strong protein-protein interactions between the two subunits of Top2, allowing the nicks to be faithfully resealed in situ. Top2ccs are normally transient, but can be trapped by cancer drugs, such as etoposide, and subsequently processed into DSBs in cells. If not properly repaired, these DSBs would lead to genome instability and cell death. Here, I review the current understanding of the mechanisms by which DSBs are induced by etoposide, the unique features of such DSBs and how they are repaired. Implications for the improvement of cancer therapy will be discussed. PMID:27376333
7. 5 CFR 1605.2 - Calculating, posting, and charging breakage.
Science.gov (United States)
2010-01-01
... will calculate breakage on late contributions, makeup agency contributions, and loan payments as... is the breakage. (c) Posting contributions and loan payments. Makeup and late contributions, late... participant's account is greater than the dollar amount of the makeup or late contribution or late...
8. Genetics Home Reference: Warsaw breakage syndrome
Science.gov (United States)
... helping repair mistakes in DNA and ensuring proper DNA replication, the ChlR1 enzyme is involved in maintaining the ... cannot unwind the DNA strands to help with DNA replication and repair. A lack of functional ChlR1 impairs ...
9. Chloroethyinitrosourea-derived ethano cytosine and adenine adducts are substrates for escherichia coli glycosylases excising analogous etheno adducts
Energy Technology Data Exchange (ETDEWEB)
Guliaev, Anton B.; Singer, B.; Hang, Bo
2004-05-05
Exocyclic ethano DNA adducts are saturated etheno ring derivatives formed mainly by therapeutic chloroethylnitrosoureas (CNUs), which are also mutagenic and carcinogenic. In this work, we report that two of the ethano adducts, 3,N{sup 4}-ethanocytosine (EC) and 1,N{sup 6}-ethanoadenine (EA), are novel substrates for the Escherichia coli mismatch-specific uracil-DNA glycosylase (Mug) and 3-methyladenine DNA glycosylase II (AlkA), respectively. It has been shown previously that Mug excises 3,N{sup 4}-ethenocytosine ({var_epsilon}C) and AlkA releases 1,N{sup 6}-ethenoadenine ({var_epsilon}A). Using synthetic oligonucleotides containing a single ethano or etheno adduct, we found that both glycosylases had a {approx}20-fold lower excision activity toward EC or EA than that toward their structurally analogous {var_epsilon}C or {var_epsilon}A adduct. Both enzymes were capable of excising the ethano base paired with any of the four natural bases, but with varying efficiencies. The Mug activity toward EC could be stimulated by E. coli endonuclease IV and, more efficiently, by exonuclease III. Molecular dynamics (MD) simulations showed similar structural features of the etheno and ethano derivatives when present in DNA duplexes. However, also as shown by MD, the stacking interaction between the EC base and Phe 30 in the Mug active site is reduced as compared to the {var_epsilon}C base, which could account for the lower EC activity observed in this study.
10. Benzoyl peroxide-induced damage to DNA and its components
DEFF Research Database (Denmark)
Hazlewood, C; Davies, Michael Jonathan
1996-01-01
, sugars, nucleosides, nucleotides, RNA, and DNA have been examined and the intermediate species have been identified in many cases. Comparison of these data with those obtained with Ph. alone has allowed the reactions of PhCO2. and Ph. to be distinguished. Evidence has been obtained which is consistent...... of base adducts, though the exact identity of the species detected in these cases could not be determined due to the complexity of the spectra. Hydrogen abstraction at the sugar-phosphate backbone is also believed to occur with these substrates as strand breakage is observed; the extent of the latter...... is dependent on the radical flux and the attacking species, with PhCO2. appearing to be a much more effective inducer of fragmentation than Ph. The nature of the species detected with all the substrates examined, with the exception of the isolated sugars where essentially random attack by both radicals...
11. Theoretical Modeling of Rock Breakage by Hydraulic and Mechanical Tool
OpenAIRE
Hongxiang Jiang; Changlong Du; Songyong Liu; Liping Wang
2014-01-01
Rock breakage by coupled mechanical and hydraulic action has been developed over the past several decades, but theoretical study on rock fragmentation by mechanical tool with water pressure assistance was still lacking. The theoretical model of rock breakage by mechanical tool was developed based on the rock fracture mechanics and the solution of Boussinesq’s problem, and it could explain the process of rock fragmentation as well as predicating the peak reacting force. The theoretical model o...
12. Marked dependence on carrier-ligand bulk but not on carrier-ligand chirality of the duplex versus single-strand forms of a DNA oligonucleotide with a series of G-Pt(II)-G intrastrand cross-links modeling cisplatin-DNA adducts.
Science.gov (United States)
Beljanski, Vladimir; Villanueva, Julie M; Doetsch, Paul W; Natile, Giovanni; Marzilli, Luigi G
2005-11-16
The N7-Pt-N7 adjacent G,G intrastrand DNA cross-link responsible for cisplatin anticancer activity is dynamic, promotes local "melting" in long DNA, and converts many oligomer duplexes to single strands. For 5'-d(A1T2G3G4G5T6A7C8C9C10A11T12)-3' (G3), treatment of the (G3)2 duplex with five pairs of [LPt(H2O)2]2+ enantiomers (L = an asymmetric diamine) formed mixtures of LPt-G3 products (1 Pt per strand) cross-linked at G3,G4 or at G4,G5 in all cases. L chirality exerted little influence. For primary diamines L with bulk on chelate ring carbons (e.g., 1,2-diaminocyclohexane), the duplex was converted completely into single strands (G3,G4 coils and G4,G5 hairpins), exactly mirroring results for cisplatin, which lacks bulk. In sharp contrast, for secondary diamines L with bulk on chelate ring nitrogens (e.g., 2,2'-bipiperidine, Bip), unexpectedly stable duplexes having two platinated strands (even a unique G3,G4/G4,G5 heteroduplex) were formed. After enzymatic digestion of BipPt-G3 duplexes, the conformation of the relatively nondynamic G,G units was shown to be head-to-head (HH) by HPLC/mass spectrometric characterization. Because the HH conformation dominates at the G,G lesion in duplex DNA and in the BipPt-G3 duplexes, the stabilization of the duplex form only when the L nitrogen adducts possess bulk suggests that H-bonding interactions of the Pt-NH groups with the flanking DNA lead to local melting and to destabilization of oligomer duplexes. The marked dependence of adduct properties on L bulk and the minimal dependence on L chirality underscore the need for future exploration of the roles of the L periphery in affecting anticancer activity. PMID:16277526
13. 2'-Deoxythymidine Adducts from the Anti-HIV Drug Nevirapine
Directory of Open Access Journals (Sweden)
M. Matilde Marques
2013-04-01
Full Text Available Nevirapine (NVP is a non-nucleoside reverse transcriptase inhibitor (NNRTI used against HIV-1. Currently, NVP is the most widely used anti-HIV drug in developing countries, both in combination therapy and to prevent mother-to-child transmission of HIV. Despite its efficacy against HIV, NVP produces a variety of toxic responses, including hepatotoxicity and skin rash. It is also associated with increased incidences of hepatoneoplasias in rodents. In addition, epidemiological data suggest that NNRTI use is a risk factor for non-AIDS-defining cancers in HIV-positive patients. Current evidence supports the involvement of metabolic activation to reactive electrophiles in NVP toxicity. NVP metabolism includes oxidation to 12-hydroxy-NVP; subsequent Phase II sulfonation produces an electrophilic metabolite, 12-sulfoxy-NVP, capable of reacting with DNA to yield covalent adducts. Since 2’-deoxythymidine (dT adducts from several alkylating agents are regarded as having significant mutagenic/carcinogenic potential, we investigated the formation of NVP-dT adducts under biomimetic conditions. Toward this goal, we initially prepared and characterized synthetic NVP-dT adduct standards using a palladium-mediated Buchwald-Hartwig coupling strategy. The synthetic standards enabled the identification, by LC-ESI-MS, of 12-(2'-deoxythymidin-N3-yl-nevirapine (N3-NVP-dT in the enzymatic hydrolysate of salmon testis DNA reacted with 12-mesyloxy-NVP, a synthetic surrogate for 12-sulfoxy-NVP. N3-NVP-dT, a potentially cytotoxic and mutagenic DNA lesion, was also the only dT-specific adduct detected upon reaction of dT with 12-mesyloxy-NVP. Our data suggest that N3-NVP-dT may be formed in vivo and play a role in the hepatotoxicity and/or putative hepatocarcinogenicity of NVP.
14. Lymphocyte chromosome breakage in low benzene exposure among Indonesian workers
Directory of Open Access Journals (Sweden)
Dewi S. Soemarko
2015-01-01
Full Text Available Background: Benzene has been used in industry since long time and its level in environment should be controled. Although environmental benzene level has been controlled to less than 1 ppm, negative effect of benzene exposure is still observed, such as chromosome breakage. This study aimed to know the prevalence of lymphocyte chromosome breakage and the influencing factors among workers in low level benzene exposure.Methods: This was a cross sectional study in oil & gas industry T, conducted between September 2007 and April 2010. The study subjects consisted of 115 workers from production section and head office. Data on type of work, duration of benzene exposure, and antioxidant consumption were collected by interview as well as observation of working process. Lymphocyte chromosome breakage was examined by banding method. Analysis of relationship between chromosome breakage and risk factors was performed by chi-square and odd ratio, whereas the role of determinant risk factors was analyzed by multivariate forward stepwise.Results: Overall lymphocyte chromosome breakage was experieced by 72 out of 115 subjects (62.61%. The prevalence among workers at production section was 68.9%, while among administration workers was 40% (p > 0.05. Low antioxidant intake increases the risk of chromosome breakage (p = 0.035; ORadjusted = 2.90; 95%CI 1.08-7.78. Other influencing factors are: type of work (p = 0,10; ORcrude = 3.32; 95% CI 1.33-8.3 and chronic benzene exposure at workplace (p = 0.014; ORcrude = 2.61; 95% CI 1.2-5.67, while the work practice-behavior decreases the lymphocyte chromosome breakage (p = 0.007; ORadjusted = 0.30; 95% CI 0.15-0.76.Conclusion: The prevalence of lymphocyte chromosome breakage in the environment with low benzene exposure is quite high especially in production workers. Chronic benzene exposure in the workplace, type of work, and low antioxidant consumption is related to lymphocyte chromosome breakage. Thus, benzene in the
15. Mutagenicity of 2-amino-3-methylimidazo[4,5-f]quinoline in colon and liver of Big Blue rats: role of DNA adducts, strand breaks, DNA repair and oxidative stress
DEFF Research Database (Denmark)
Moller, P.; Wallin, H.; Vogel, U.;
2002-01-01
The contribution of oxidative stress, different types of DNA damage and expression of DNA repair enzymes in colon and liver mutagenesis induced by 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) was investigated in four groups of six Big Blue rats fed diets with 0, 20, 70, and 200 mg IQ/kg for 3....... Investigations of oxidative stress biomarkers produced inconclusive results. Oxidative DNA damage detected by the endonuclease III enzyme and 7-hydro-8-oxo-2'-deoxyguanosine in colon, liver and/or urine was unaltered by IQ. However, there was increased level of gamma-glutamyl semialdehyde in liver proteins......, indicating a higher rate of protein oxidation in the liver following IQ administration. In plasma and erythrocytes there were unaltered levels of oxidized protein, malondialdehyde, and antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, catalase, glutathione reductase) indicating...
16. Mutagenicity of 2-amino-3-methylimidazo[4,5-f]quinoline in colon and liver of Big Blue Rats: role of DNA adducts, strand breaks, DNA repair and oxidative stress
DEFF Research Database (Denmark)
Møller, Peter; Wallin, Håkan; Vogel, Ulla;
2002-01-01
The contribution of oxidative stress, different types of DNA damage and expression of DNA repair enzymes in colon and liver mutagenesis induced by 2-amino-3-methylimidazo [4,5-f]quinoline (IQ) was investigated in four groups of six Big Blue rats fed diets with 0, 20, 70, and 200 mg IQ/kg for 3....... Investigations of oxidative stress biomarkers produced inconclusive results. Oxidative DNA damage detected by the endonuclease III enzyme and 7-hydro-8-oxo-2'-deoxyguanosine in colon, liver and/or urine was unaltered by IQ. However, there was increased level of gamma-glutamyl semialdehyde in liver proteins......, indicating a higher rate of protein oxidation in the liver following IQ administration. In plasma and erythrocytes there were unaltered levels of oxidized protein, malondialdehyde, and antioxidant enzyme activities (superoxide dismutase, glutathione peroxidase, catalase, glutathione reductase) indicating...
17. Responding to chromosomal breakage during M-phase: insights from a cell-free system
Directory of Open Access Journals (Sweden)
Costanzo Vincenzo
2009-07-01
Full Text Available Abstract DNA double strand breaks (DSBs activate ATM and ATR dependent checkpoints that prevent the onset of mitosis. However, how cells react to DSBs occurring when they are already in mitosis is poorly understood. The Xenopus egg extract has been utilized to study cell cycle progression and DNA damage checkpoints. Recently this system has been successfully used to uncover an ATM and ATR dependent checkpoint affecting centrosome driven spindle assembly. These studies have led to the identification of XCEP63 as major target of this pathway. XCEP63 is a coiled-coil rich protein localized at centrosome essential for proper spindle assembly. ATM and ATR directly phosphorylate XCEP63 on serine 560 inducing its delocalization from centrosome, which in turn delays spindle assembly. This pathway might contribute to regulate DNA repair or mitotic cell survival in the presence of chromosome breakage.
18. Packaging effects on shell egg breakage rates during simulated transportation.
Science.gov (United States)
Seydim, A C; Dawson, P L
1999-01-01
Shell eggs were packaged in either expanded polystyrene (EPS) foam or molded paper pulp (MPP) one dozen cartons, then were bulk packaged in either polypropylene crates or corrugated boxes. The packages were then subjected to a well-defined computer-simulated vibration test on an electrohydraulic test machine. The percentage and the location on the egg (side, top, bottom) of breakage was determined in the secondary (corrugated box or polypropylene crate) and primary (EPS or MPP carton) package after 15, 75, and 180 min. For each of three trials, 60 dozen Grade A large eggs were randomly assigned to each primary package and cross-stacked in a secondary container that contained three cartons in a row and a total of five layers. When cartons were packed in 15-dozen corrugated boxes, no significant difference was found in total eggshell damage rates between the MPP carton and the EPS carton. However, when eggs were packed in 15-dozen plastic crates, the MPP cartons caused significantly less eggshell damage than the EPS cartons. The EPS cartons packed in corrugated boxes had the lowest breakage (4.63%), whereas the EPS foam cartons packed in plastic crates had the highest breakage (12.59%). When the effect of secondary packaging and vibration time were not considered, no significant difference was found between MPP and EPS cartons. In addition, when the effect of primary packaging was not taken into account, the corrugated boxes had significantly lower breakage rates than the plastic crates. Nearly 55% of the breakage occurred in the bottom section of the eggshell as compared to the side and top. When the test periods were compared, the EPS cartons packed in plastic crates had the highest breakage (16.28%) at 180 min.
19. Inhibition of peroxynitrite-mediated DNA strand cleavage and hydroxyl radical formation by aspirin at pharmacologically relevant concentrations: Implications for cancer intervention
Energy Technology Data Exchange (ETDEWEB)
Chen, Wei [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States); College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035 (China); Department of Food Science and Technology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Zhu, Hong; Jia, Zhenquan [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States); Li, Jianrong [College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310035 (China); Misra, Hara P. [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States); Zhou, Kequan, E-mail: kzhou@wayne.edu [Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202 (United States); Li, Yunbo, E-mail: yli@vcom.vt.edu [Division of Biomedical Sciences, Edward Via Virginia College of Osteopathic Medicine, Virginia Tech Corporate Research Center, Blacksburg, VA 24060 (United States)
2009-12-04
Epidemiological studies have suggested that the long-term use of aspirin is associated with a decreased incidence of human malignancies, especially colorectal cancer. Since accumulating evidence indicates that peroxynitrite is critically involved in multistage carcinogenesis, this study was undertaken to investigate the ability of aspirin to inhibit peroxynitrite-mediated DNA damage. Peroxynitrite and its generator 3-morpholinosydnonimine (SIN-1) were used to cause DNA strand breaks in {phi}X-174 plasmid DNA. We demonstrated that the presence of aspirin at concentrations (0.25-2 mM) compatible with amounts in plasma during chronic anti-inflammatory therapy resulted in a significant inhibition of DNA cleavage induced by both peroxynitrite and SIN-1. Moreover, the consumption of oxygen caused by 250 {mu}M SIN-1 was found to be decreased in the presence of aspirin, indicating that aspirin might affect the auto-oxidation of SIN-1. Furthermore, EPR spectroscopy using 5,5-dimethylpyrroline-N-oxide (DMPO) as a spin trap demonstrated the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from authentic peroxynitrite, and that aspirin at 0.25-2 mM potently diminished the radical adduct formation in a concentration-dependent manner. Taken together, these results demonstrate for the first time that aspirin at pharmacologically relevant concentrations can inhibit peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation. These results may have implications for cancer intervention by aspirin.
20. Inhibition of peroxynitrite-mediated DNA strand cleavage and hydroxyl radical formation by aspirin at pharmacologically relevant concentrations: Implications for cancer intervention
International Nuclear Information System (INIS)
Epidemiological studies have suggested that the long-term use of aspirin is associated with a decreased incidence of human malignancies, especially colorectal cancer. Since accumulating evidence indicates that peroxynitrite is critically involved in multistage carcinogenesis, this study was undertaken to investigate the ability of aspirin to inhibit peroxynitrite-mediated DNA damage. Peroxynitrite and its generator 3-morpholinosydnonimine (SIN-1) were used to cause DNA strand breaks in φX-174 plasmid DNA. We demonstrated that the presence of aspirin at concentrations (0.25-2 mM) compatible with amounts in plasma during chronic anti-inflammatory therapy resulted in a significant inhibition of DNA cleavage induced by both peroxynitrite and SIN-1. Moreover, the consumption of oxygen caused by 250 μM SIN-1 was found to be decreased in the presence of aspirin, indicating that aspirin might affect the auto-oxidation of SIN-1. Furthermore, EPR spectroscopy using 5,5-dimethylpyrroline-N-oxide (DMPO) as a spin trap demonstrated the formation of DMPO-hydroxyl radical adduct (DMPO-OH) from authentic peroxynitrite, and that aspirin at 0.25-2 mM potently diminished the radical adduct formation in a concentration-dependent manner. Taken together, these results demonstrate for the first time that aspirin at pharmacologically relevant concentrations can inhibit peroxynitrite-mediated DNA strand breakage and hydroxyl radical formation. These results may have implications for cancer intervention by aspirin.
1. DURABILITY AND BREAKAGE OF FEED PELLETS DURING REPEATED ELEVATOR HANDLING
Science.gov (United States)
Pelleting of animal feeds is important for improved feeding efficiency and for convenience of handling. Pellet quality impacts the feeding benefits for the animals and pellet integrity during handling. To determine the effect of repeated handling on feed pellet breakage and durability, a 22.6-t (100...
2. The boron trifluoride nitromethane adduct
Science.gov (United States)
Ownby, P. Darrell
2004-02-01
The separation of the boron isotopes using boron trifluoride·organic-donor, Lewis acid·base adducts is an essential first step in preparing 10B enriched and depleted crystalline solids so vital to nuclear studies and reactor applications such as enriched MgB 2, boron carbide, ZrB 2, HfB 2, aluminum boron alloys, and depleted silicon circuits for radiation hardening and neutron diffraction crystal structure studies. The appearance of this new adduct with such superior properties demands attention in the continuing search for more effective and efficient means of separation. An evaluation of the boron trifluoride nitromethane adduct, its thermodynamic and physical properties related to large-scale isotopic separation is presented. Its remarkably high separation factor was confirmed to be higher than the expected theoretical value. However, the reportedly high acid/donor ratio was proven to be an order of magnitude lower. On-going research is determining the crystal structure of deuterated and 11B enriched 11BF 3·CD 3NO 2 by X-ray and neutron diffraction.
3. Amifostine Protection Against Mitomycin-induced Chromosomal Breakage in Fanconi Anaemia Lymphocytes
Directory of Open Access Journals (Sweden)
Miriam T. P. Lopes
2008-08-01
Full Text Available Fanconi anaemia (FA is a rare genetic chromosomal instability syndrome caused by impairment of DNA repair and reactive oxygen species (ROS imbalance. This disease is also related to bone marrow failure and cancer. Treatment of these complications with radiation and alkylating agents may enhance chromosomal breakage. We have evaluated the effect of amifostine (AMF on basal and mitomycin C (MMC-induced chromosomal breakage in FA blood cells using the micronucleus assay. The basal micronuclei count was higher among FA patients than healthy subjects. Pre-treatment with AMF significantly inhibited micronucleation induced by MMC in healthy subjects (23.4 ± 4.0 – MMC vs 12.3 ± 2.9 – AMF →MMC MN/1000CB, p < 0.01, one way ANOVA as well as in FA patients (80.0 ± 5.8 – MMC vs 40.1 ± 5.8 – AMF →MMC MN/1000CB, p < 0.01, ANOVA. Release of ROS by peripheral blood mononuclear cells treated with AMF →MMC and measured by chemoluminometry showed that AMF-protection was statistically higher among FA patients than in healthy individuals. Based on these results we suggest that AMF prevents chromosomal breakage induced by MMC, probably by its antioxidant effect.
4. Persistence of Breakage in Specific Chromosome Bands 6 Years after Acute Exposure to Oil
Science.gov (United States)
Francés, Alexandra; Hildur, Kristin; Barberà, Joan Albert; Rodríguez-Trigo, Gema; Zock, Jan-Paul; Giraldo, Jesús; Monyarch, Gemma; Rodriguez-Rodriguez, Emma; de Castro Reis, Fernanda; Souto, Ana; Gómez, Federico P.; Pozo-Rodríguez, Francisco; Templado, Cristina; Fuster, Carme
2016-01-01
Background The identification of breakpoints involved in chromosomal damage could help to detect genes involved in genetic disorders, most notably cancer. Until now, only one published study, carried out by our group, has identified chromosome bands affected by exposure to oil from an oil spill. In that study, which was performed two years after the initial oil exposure in individuals who had participated in clean-up tasks following the wreck of the Prestige, three chromosomal bands (2q21, 3q27, 5q31) were found to be especially prone to breakage. A recent follow-up study, performed on the same individuals, revealed that the genotoxic damage had persisted six years after oil exposure. Objectives To determine whether there exist chromosome bands which are especially prone to breakages and to know if there is some correlation with those detected in the previous study. In addition, to investigate if the DNA repair problems detected previously persist in the present study. Design Follow-up study performed six years after the Prestige oil spill. Setting Fishermen cooperatives in coastal villages. Participants Fishermen highly exposed to oil spill who participated in previous genotoxic study six years after the oil. Measurements Chromosome damage in peripheral lymphocytes. For accurate identification of the breakpoints involved in chromosome damage of circulating lymphocytes, a sequential stain/G-banding technique was employed. To determine the most break-prone chromosome bands, two statistical methods, the Fragile Site Multinomial and the chi-square tests (where the bands were corrected by their length) were used. To compare the chromosome lesions, structural chromosome alterations and gaps/breaks between two groups of individuals we used the GEE test which takes into account a possible within-individual correlation. Dysfunctions in DNA repair mechanisms, expressed as chromosome damage, were assessed in cultures with aphidicolin by the GEE test. Results Cytogenetic
5. Moment methods for coagulation, breakage and coalescence problems
Science.gov (United States)
Diemer, Russell Bertrum, Jr.
This work advances the art of modeling coagulation, breakage and coalescence of agglomerated particles. Such models apply to industrial particle processing unit operations and their analogs (e.g., polymerization and depolymerization). Direct calculation of particle-size distribution evolution proceeds by a division of the size spectrum into many small sections. The computing resources required preclude coupling this approach with detailed equipment piece or process flowsheet simulations. Conventional moment models are computationally less demanding, but sacrifice distribution detail. In this work, a moment approach is developed which restores that lost detail, and includes: (1) a closure rule for solving the general dynamic moment problem, (2) basis sets upon which to reconstruct the distributions from the moment solutions, and (3) a technique to guide the reconstruction. The basis sets are founded upon a new, general class of distribution functions which contains many of the familiar distribution functions. Coalescence alters an agglomerate's surface area without changing its volume. In addition, the coalescence time scale may differ from those characteristic of the volume-altering processes of coagulation and breakage. For these reasons, a single distribution variable (e.g., volume) is generally inadequate to describe coalescing populations. In this work, a bivariate formulation is developed which casts the particle distribution as the product of a marginal distribution in volume and a volume-conditional distribution in surface area. Reconstruction of the full bivariate distribution hinges on a relationship between the bivariate moments and the conditional area moments. These developments are facilitated by a generalization of breakage daughter distributions, and the discernment of bivariate breakage types, leading to the specification of bivariate daughter distributions. Insight toward the moment methodology comes from approximate analytical steady
6. Structural and biochemical impact of C8-aryl-guanine adducts within the NarI recognition DNA sequence: influence of aryl ring size on targeted and semi-targeted mutagenicity
OpenAIRE
Sproviero, Michael; Verwey, Anne M.R.; Rankin, Katherine M.; Witham, Aaron A.; Soldatov, Dmitriy V.; Richard A. Manderville; Fekry, Mostafa I.; Sturla, Shana J.; Sharma, Purshotam; Wetmore, Stacey D.
2014-01-01
Chemical mutagens with an aromatic ring system may be enzymatically transformed to afford aryl radical species that preferentially react at the C8-site of 2′-deoxyguanosine (dG). The resulting carbon-linked C8-aryl-dG adduct possesses altered biophysical and genetic coding properties compared to the precursor nucleoside. Described herein are structural and in vitro mutagenicity studies of a series of fluorescent C8-aryl-dG analogues that differ in aryl ring size and are representative of auth...
7. Dynamic rupture in a damage-breakage rheology model
Science.gov (United States)
Lyakhovsky, Vladimir; Ben-Zion, Yehuda; Ilchev, Assen; Mendecki, Aleksander
2016-08-01
We present a thermodynamically based formulation for modelling dynamic rupture processes in the brittle crust using a continuum damage-breakage rheology. The model combines aspects of a continuum viscoelastic damage framework for brittle solids with a continuum breakage mechanics for granular flow within dynamically generated slip zones. The formulation accounts for the density of distributed cracking and other internal flaws in damaged rocks with a scalar damage parameter, and addresses the grain size distribution of a granular phase in the slip zone with a breakage parameter. A dynamic brittle instability is associated with a critical level of damage in the solid, leading to loss of convexity of the solid strain energy, localization and transition to a granular phase associated with lower energy level. The continuum damage-breakage rheology model treats the localization to a slip zone at the onset of dynamic rupture and post-failure recovery process as phase transitions between solid and granular states. The model generates sub- and supershear rupture velocities and pulse-type ruptures seen also in frictional models, and additional important features such as strong dynamic changes of volumetric strain near the rupture front and diversity of nucleation mechanisms. The propagation of rupture front and slip accumulation at a point are correlated with sharp dynamic dilation followed by a gradual decay to a level associated with the final volumetric change associated with the granular phase transition in the slipping zone. The local brittle failure process associated with the solid-granular transition is expected to produce isotropic radiation in addition to the deviatoric terms. The framework significantly extends the ability to model brittle processes in complex geometrical structures and allows analysing the roles of gouge thickness and other parameters on nucleation, rupture and radiation characteristics.
8. Dynamic rupture in a damage-breakage rheology model
Science.gov (United States)
Lyakhovsky, Vladimir; Ben-Zion, Yehuda; Ilchev, Assen; Mendecki, Aleksander
2016-05-01
We present a thermodynamically-based formulation for modeling dynamic rupture processes in the brittle crust using a continuum damage-breakage rheology. The model combines aspects of a continuum viscoelastic damage framework for brittle solids with a continuum breakage mechanics for granular flow within dynamically generated slip zones. The formulation accounts for the density of distributed cracking and other internal flaws in damaged rocks with a scalar damage parameter, and addresses the grain size distribution of a granular phase in the slip zone with a breakage parameter. A dynamic brittle instability is associated with a critical level of damage in the solid, leading to loss of convexity of the solid strain energy, localization, and transition to a granular phase associated with lower energy level. The continuum damage-breakage rheology model treats the localization to a slip zone at the onset of dynamic rupture and post-failure recovery process as phase transitions between solid and granular states. The model generates sub- and super-shear rupture velocities and pulse-type ruptures seen also in frictional models, and additional important features such as strong dynamic changes of volumetric strain near the rupture front and diversity of nucleation mechanisms. The propagation of rupture front and slip accumulation at a point are correlated with sharp dynamic dilation followed by a gradual decay to a level associated with the final volumetric change associated with the granular phase transition in the slipping zone. The local brittle failure process associated with the solid-granular transition is expected to produce isotropic radiation in addition to the deviatoric terms. The framework significantly extends the ability to model brittle processes in complex geometrical structures and allows analyzing the roles of gouge thickness and other parameters on nucleation, rupture and radiation characteristics.
9. Breakage of Corn Kernel on an Vertical Elevator Transportation
Directory of Open Access Journals (Sweden)
Stjepan Pliestić
2001-12-01
Full Text Available Examining breakage of corn kernel on an elevator, the means for vertical transportation, the paper compares the mechanical resistance of the OSSK 552 maize hybrid when entering and leaving the elevator. The declared capacity of the elevator was 64 m3/h, the volume of each of the 360 buckets contained 2.1 dm3, the number of turns of the reductor and consequently of the upper drive pulley of the elevator amounted to 80 min-1. It was established that during the mentioned transportation the breakage had increased, but not in same amount. The damage was examined on samples of different moisture content distributed into four groups: 28-30 %;23-25 %;17 19 % and 11-13 %. In the 29 % moisture content of the material the end of breakage was 1,33% higher than the beginning one. If expressed relatively, this is a difference of 19,32 %. In the moisture of the corn kernel of 23 %, this difference amounted to 1,03 %, relatively 22,94 %, while in the moisture of the material of 18 %, the difference was 2,34 %, relatively 30,51 %. In the driest sample of the material, of 12 %, the difference amounted to 2,57 %, relatively even 24,83 %.
10. Bilateral failure of adduction following orbital decompression.
OpenAIRE
Kinsella, F; Kyle, P.; Stansfield, A
1990-01-01
We report a case of bilateral complete failure of adduction following bilateral translid antralethmoidal orbital decompression. We believe the probable mechanism is neuropraxia (temporary dysfunction) of the third cranial nerves' supply to the medial recti, owing to these nerves' occupying an anatomically abnormal position. Partial recovery of adduction occurred over the ensuing six months.
11. Exposure to 1800 MHz radiofrequency electromagnetic radiation induces oxidative DNA base damage in a mouse spermatocyte-derived cell line.
Science.gov (United States)
Liu, Chuan; Duan, Weixia; Xu, Shangcheng; Chen, Chunhai; He, Mindi; Zhang, Lei; Yu, Zhengping; Zhou, Zhou
2013-03-27
Whether exposure to radiofrequency electromagnetic radiation (RF-EMR) emitted from mobile phones can induce DNA damage in male germ cells remains unclear. In this study, we conducted a 24h intermittent exposure (5 min on and 10 min off) of a mouse spermatocyte-derived GC-2 cell line to 1800 MHz Global System for Mobile Communication (GSM) signals in GSM-Talk mode at specific absorption rates (SAR) of 1 W/kg, 2 W/kg or 4 W/kg. Subsequently, through the use of formamidopyrimidine DNA glycosylase (FPG) in a modified comet assay, we determined that the extent of DNA migration was significantly increased at a SAR of 4 W/kg. Flow cytometry analysis demonstrated that levels of the DNA adduct 8-oxoguanine (8-oxoG) were also increased at a SAR of 4 W/kg. These increases were concomitant with similar increases in the generation of reactive oxygen species (ROS); these phenomena were mitigated by co-treatment with the antioxidant α-tocopherol. However, no detectable DNA strand breakage was observed by the alkaline comet assay. Taking together, these findings may imply the novel possibility that RF-EMR with insufficient energy for the direct induction of DNA strand breaks may produce genotoxicity through oxidative DNA base damage in male germ cells.
12. Triple helix-forming oligonucleotides target psoralen adducts to specific chromosomal sequences in human cells.
OpenAIRE
Oh, D H; Hanawalt, P C
1999-01-01
The ability to target photochemical adducts to specific genomic DNA sequences in cells is useful for studying DNA repair and mutagenesis in intact cells, and also as a potential mode of gene-specific therapy. Triple helix-forming DNA oligonucleotides linked to psoralen (psoTFOs) were designed to deliver UVA-induced psoralen photoadducts to two distinct sequences within the human interstitial collagenase gene. A primer extension assay demonstrated that the appropriate psoTFO selectively damage...
13. LC-MS/MS screening strategy for unknown adducts to N-terminal valine in hemoglobin applied to smokers and nonsmokers.
Science.gov (United States)
Carlsson, Henrik; von Stedingk, Hans; Nilsson, Ulrika; Törnqvist, Margareta
2014-12-15
14. Breakage of Corn Kernel on an Vertical Elevator Transportation
OpenAIRE
Stjepan Pliestić; Marko Šutalo
2001-01-01
Examining breakage of corn kernel on an elevator, the means for vertical transportation, the paper compares the mechanical resistance of the OSSK 552 maize hybrid when entering and leaving the elevator. The declared capacity of the elevator was 64 m3/h, the volume of each of the 360 buckets contained 2.1 dm3, the number of turns of the reductor and consequently of the upper drive pulley of the elevator amounted to 80 min-1. It was established that during the mentioned transportation the break...
15. Combinatorics of the breakage-fusion-bridge mechanism.
Science.gov (United States)
Kinsella, Marcus; Bafna, Vineet
2012-06-01
The breakage-fusion-bridge (BFB) mechanism was proposed over seven decades ago and is a source of genomic variability and gene amplification in cancer. Here we formally model and analyze the BFB mechanism, to our knowledge the first time this has been undertaken. We show that BFB can be modeled as successive inverted prefix duplications of a string. Using this model, we show that BFB can achieve a surprisingly broad range of amplification patterns. We find that a sequence of BFB operations can be found that nearly fits most patterns of copy number increases along a chromosome. We conclude that this limits the usefulness of methods like array CGH for detecting BFB.
16. Effect of particle breakage on cyclic densification of ballast: A DEM approach
International Nuclear Information System (INIS)
In this paper, an attempt has been made to investigate the effect of particle breakage on densification behaviour of ballast under cyclic loading using Discrete Element Method (DEM). Numerical simulations using PFC2D have been carried out on an assembly of angular particles with and without incorporation of particle breakage. Two-dimensional projection of angular ballast particles were simulated using clusters of bonded circular particles. Degradation of the bonds within a cluster was considered to represent particle breakage. Clump logic was used to make the cluster of particles unbreakable. DEM simulation results highlight that the particle breakage has a profound influence on the cyclic densification behaviour of ballast. The deformation behaviour exhibited by the assembly with breakage is in good agreement with the laboratory experiments. In addition, the evolution of particle displacement vectors clearly explains the breakage mechanism and associated deformations during cyclic loading.
17. Effect of particle breakage on cyclic densification of ballast: A DEM approach
Science.gov (United States)
Thakur, P. K.; Vinod, J. S.; Indraratna, B.
2010-06-01
In this paper, an attempt has been made to investigate the effect of particle breakage on densification behaviour of ballast under cyclic loading using Discrete Element Method (DEM). Numerical simulations using PFC2D have been carried out on an assembly of angular particles with and without incorporation of particle breakage. Two-dimensional projection of angular ballast particles were simulated using clusters of bonded circular particles. Degradation of the bonds within a cluster was considered to represent particle breakage. Clump logic was used to make the cluster of particles unbreakable. DEM simulation results highlight that the particle breakage has a profound influence on the cyclic densification behaviour of ballast. The deformation behaviour exhibited by the assembly with breakage is in good agreement with the laboratory experiments. In addition, the evolution of particle displacement vectors clearly explains the breakage mechanism and associated deformations during cyclic loading.
18. Experimental Study on Methane Explosion Ignited by Sparks of Cable Bolt Breakage
Institute of Scientific and Technical Information of China (English)
MA Wen-ding; XU Jia-lin; ZHANG Shao-hua
2004-01-01
An experimental device was designed for studying methane explosion ignited by sparks of cable bolt breakage. With the methane concentration being in explosion range, a series of experiments were conducted to study the law of spark generation during cable bolt breakage and the probability of methane explosion caused by the spark. The results show that the probability of generating sparks during cable bolt breakage is 50%. The spark generated by the breakage of steel cable bolt strand can't ignite a methane explosion. A detection was carried out using infrared-ray imaging apparatus (IRIA) to measure temperature of the spark generated by cable bolt breakage. It is indicated that the maximum temperature of the spark generated by cable bolt breakage is far less than the required ignition temperature for a methane explosion.
19. A note on handaxe knapping products and their breakage taphonomy: an experimental view
Directory of Open Access Journals (Sweden)
2015-03-01
Full Text Available The notion that broken artifacts provide a good indication of the taphonomic history of lithic assemblages is commonly accepted in prehistoric archaeology. High frequencies of broken artifacts are frequently viewed as an indication of the possible role of post-depositional processes such as high-energy fluvial transportation, trampling or plowing. Yet another alternative is that the breakage resulted from the knapping process itself.In this study, the knapping byproducts of biface shaping and thinning (the final stages of handaxe production originating in several experiments were systematically studied and their breakage frequencies and patterns were determined. The breakage patterns observed for the experimental assemblages were then used in a model designed to simulate the effect of breakage resulting from post-depositional processes, providing the breakage patterns expected for such an assemblage.The breakage pattern and frequencies observed in the experimental assemblages and those provided by the model were then compared to an archaeological assemblage representing the production of Acheulian assemblages that include bifaces from the site of Gesher Benot Ya‘aqov (GBY, Israel. The results indicate that high breakage rates are inherent to the final stages of the Acheulian bifacial knapping process. Furthermore, they demonstrate that taphonomic (post-depositional breakage changes the breakage pattern of the production stages in a systematic trend. Finally, the results show that the lithic assemblage of GBY presents breakage frequencies and patterns that are more similar to those of the experimental assemblages than those generated by the model. In the light of these results, it is suggested that this assemblage was not subjected to any breakage caused by post-depositional processes.
20. Empirical Formulae for Breakage of Dolosse and Tetrapods
DEFF Research Database (Denmark)
Burcharth, H. F.; d'Angremond, K.; Meer, W. van der;
2000-01-01
which allows studies of armour unit stresses by means of a load-cell technique. The technique necessitates impact load response calibration of the load-cell mounted model armour units against the equivalent response of prototype or large scale armour units. The procedure followed was presented...... and the hydraulic stability (resistance to displacements) of the armour layers. Breakage occurs when the stresses from the static, pulsating and impact loads exceeds the tensile strength of the concrete. While the hydraulic stability can be studied in Froude-scale hydraulic model tests, it is not possible to study...... armour unit stresses in small scale models. This is partly because the strain in model armour units are too small to be recorded, and partly because the scaling law for impact load generated stresses is nonlinear. The paper discusses the scaling laws related to type of stresses and presents a method...
1. Mutagen sensitivity as measured by induced chromatid breakage as a marker of cancer risk.
Science.gov (United States)
Wu, Xifeng; Zheng, Yun-Ling; Hsu, T C
2014-01-01
Risk assessment is now recognized as a multidisciplinary process, extending beyond the scope of traditional epidemiologic methodology to include biological evaluation of interindividual differences in carcinogenic susceptibility. Modulation of environmental exposures by host genetic factors may explain much of the observed interindividual variation in susceptibility to carcinogenesis. These genetic factors include, but are not limited to, carcinogen metabolism and DNA repair capacity. This chapter describes a standardized method for the functional assessment of mutagen sensitivity. This in vitro assay measures the frequency of mutagen-induced breaks in the chromosomes of peripheral blood lymphocytes. Mutagen sensitivity assessed by this method has been shown to be a significant risk factor for tobacco-related maladies, especially those of the upper aerodigestive tract. Mutagen sensitivity may therefore be a useful member of a panel of susceptibility markers for defining high-risk subgroups for chemoprevention trials. This chapter describes methods for and discusses results from studies of mutagen sensitivity as measured by quantifying chromatid breaks induced by clastogenic agents, such as the γ-radiation mimetic DNA cross-linking agent bleomycin and chemicals that form so-called bulky DNA adducts, such as 4-nitroquinoline and the tobacco smoke constituent benzo[a]pyrene, in short-term cultured peripheral blood lymphocytes.
2. Mechanical Properties of Photovoltaic Silicon in Relation to Wafer Breakage
Science.gov (United States)
Kulshreshtha, Prashant Kumar
This thesis focuses on the fundamental understanding of stress-modified crack-propagation in photovoltaic (PV) silicon in relation to the critical issue of PV silicon "wafer breakage". The interactions between a propagating crack and impurities/defects/residual stresses have been evaluated for consequential fracture path in a thin PV Si wafer. To investigate the mechanism of brittle fracture in silicon, the phase transformations induced by elastic energy released at a propagating crack-tip have been evaluated by locally stressing the diamond cubic Si lattice using a rigid Berkovich nanoindenter tip (radius ≈50 nm). Unique pressure induced phase transformations and hardness variations have been then related to the distribution of precipitates (O, Cu, Fe etc.), and the local stresses in the wafer. This research demonstrates for the first time the "ductile-like fracture" in almost circular crack path that significantly deviates from its energetically favorable crystallographic [110](111) system. These large diameter (≈ 200 mm) Si wafers were sliced to less than 180 microm thickness from a Czochralski (CZ) ingot that was grown at faster than normal growth rates. The vacancy (vSi) driven precipitation of oxygen at enhanced thermal gradients in the wafer core develops large localized stresses (upto 100 MPa) which we evaluated using Raman spectral analysis. Additional micro-FTIR mapping and microscopic etch pit measurements in the wafer core have related the observed crack path deviations to the presence of concentric ring-like distributions of oxygen precipitates (OPs). To replicate these "real-world" breakage scenarios and provide better insight on crack-propagation, several new and innovative tools/devices/methods have been developed in this study. An accurate quantitative profiling of local stress, phase changes and load-carrying ability of Si lattice has been performed in the vicinity of the controlled micro-cracks created using micro-indentations to represent
3. Hip adduction and abduction strength profiles in elite soccer players
DEFF Research Database (Denmark)
Thorborg, Kristian; Serner, Andreas; Petersen, Jesper;
2011-01-01
An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....
4. Hip adduction and abduction strength profiles in elite soccer players
DEFF Research Database (Denmark)
Serner, Andreas; Petersen, Jesper; Madsen, Thomas Moller;
2011-01-01
An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....
5. Clinical course and therapeutic implications for lymphoid malignancies in Nijmegen breakage syndrome.
Science.gov (United States)
Pastorczak, Agata; Szczepanski, Tomasz; Mlynarski, Wojciech
2016-03-01
Nijmegen breakage syndrome (NBS, MIM #251260) is an autosomal recessive chromosomal instability disorder. Majority of patients affected are of Slavic origin and share the same founder mutation of 657del5 within the NBN gene encoding protein involved in DNA double-strand breaks repair. Clinically, this is characterized by a microcephaly, immunodeficiency and a high incidence of pediatric malignancies, mostly lymphomas and leukemias. Anticancer treatment among patients with NBS is challenging because of a high risk of life threatening therapy-related toxicity including severe infections, bone marrow failure, cardio- and nephrotoxicity and occurrence of secondary cancer. Based on systemic review of available literature and the Polish acute lymphoblastic leukemia database we concluded that among patients with NBS, these who suffered from clinically proven severe immunodeficiency are at risk of the complications associated with oncological treatment. Thus, in this group it reasonable to reduce chemotherapy up to 50% especially concerning anthracyclines methotrexate, alkylating agents and epipodophyllotoxines, bleomycin and radiotherapy should be omitted. Moreover, infection prophylaxis using intravenous immunoglobulin supplementation together with antifungal and antibacterial agent is recommended. To replace radiotherapy or some toxic anticancer agents targeted therapy using monoclonal antibodies and kinase inhibitors or bone marrow transplantation with reduced-intensity conditioning should be considered in some cases, however, this statement needs further studies. PMID:26826318
6. Chromosomal Instability and Molecular Defects in Induced Pluripotent Stem Cells from Nijmegen Breakage Syndrome Patients.
Science.gov (United States)
Halevy, Tomer; Akov, Shira; Bohndorf, Martina; Mlody, Barbara; Adjaye, James; Benvenisty, Nissim; Goldberg, Michal
2016-08-30
Nijmegen breakage syndrome (NBS) results from the absence of the NBS1 protein, responsible for detection of DNA double-strand breaks (DSBs). NBS is characterized by microcephaly, growth retardation, immunodeficiency, and cancer predisposition. Here, we show successful reprogramming of NBS fibroblasts into induced pluripotent stem cells (NBS-iPSCs). Our data suggest a strong selection for karyotypically normal fibroblasts to go through the reprogramming process. NBS-iPSCs then acquire numerous chromosomal aberrations and show a delayed response to DSB induction. Furthermore, NBS-iPSCs display slower growth, mitotic inhibition, a reduced apoptotic response to stress, and abnormal cell-cycle-related gene expression. Importantly, NBS neural progenitor cells (NBS-NPCs) show downregulation of neural developmental genes, which seems to be mediated by P53. Our results demonstrate the importance of NBS1 in early human development, shed light on the molecular mechanisms underlying this severe syndrome, and further expand our knowledge of the genomic stress cells experience during the reprogramming process. PMID:27545893
7. Eleven Polish patients with microcephaly, immunodeficiency, and chromosomal instability: The Nijmegan breakage syndrome
Energy Technology Data Exchange (ETDEWEB)
Chrzanowska, K.H.; Krajewska-Walasek, M.; Gutkowska, A. [Memorial Hospital-Child Health Center, Warsaw (Poland)] [and others
1995-07-03
We report on 11 patients with 8 independent families (3 pairs of sibs) with a complex clinical pattern including microcephaly, peculiar {open_quotes}bird-like{close_quotes} face, growth retardation, and, in some cases, mild-to-moderate mental deficiency. Most of the patients have recurring respiratory tract infections. One girl has developed B-cell lymphoma. A detailed anthropometric study of 15 physical parameters, including 3 cephalic traits, was performed. It was possible to study the chromosomes of PHA-stimulated lymphocytes in all of the patients. We found structural aberrations with multiple rearrangements, preferentially involving chromosomes 7 and 14 in a proportion of metaphases in all individuals. Profound humoral and cellular immune defects were observed. Serum AFP levels were within normal range. Radioresistant DNA synthesis was strongly increased in all 8 patients who were hitherto studied in this respect. Our patients fulfill the criteria of the Nijmegen breakage syndrome, which belongs to the growing category of ataxia telangiectasia-related genetic disorders. In light of the increased predisposition to malignancy in this syndrome, an accurate diagnosis is important for the patient. 27 refs., 5 figs., 4 tabs.
8. The gene for Nijmegen breakage syndrome (V2) is not located on chromosome 11
Energy Technology Data Exchange (ETDEWEB)
Kenshi Komatsu; Shinya Matsuura; Hiroshi Tauchi; Satoru Endo [Hiroshima Univ. (Japan)] [and others
1996-04-01
Ataxia telanglectasia (AT) is an autosomal recessive disorder characterized by oculocutaneous telangiectasia and cerebellar ataxia. Individuals with this disorder display immunological impairments, hypersensitivity to ionizing radiation, and a predisposition to cancer. There has been reported genetic heterogeneity in AT, which appeared to include four genetic complementation groups in classical AT - i.e., A, B/C, D, E - and two variants, so-called Nijmegen breakage syndrome (NBS), V1 and V2. Among the four groups of classical AT, no significant differences in clinical appearance have been seen. Familial linkage analyses have produced evidence that genes for all four complementation groups in classical AT reside in a narrow region on chromosome 11q22-23. On the other hand, NBS patients have neither cerebellar ataxia nor telanglectasia but do display microcephaly and a developmental delay. However, patients share features with AT, such as high radiosensitivity, radioresistant DNA synthesis (RDS), and chromosome instability, suggesting that the same pathway (or part thereof) is impaired in both syndromes. The underlying gene for NBS has not yet been identified, and its location in the human genome is still unknown. 15 refs., 3 figs.
9. New adducts of Lapachol with primary amines
Energy Technology Data Exchange (ETDEWEB)
Santos, Mirelly D.F.; Litivack-Junior, Jose T.; Antunes, Roberto V.; Silva, Tania M.S.; Camara, Celso A., E-mail: ccelso@dq.ufrpe.b [Universidade Federal Rural de Pernambuco (UFRPE), Recife, PE (Brazil). Dept. de Quimica
2011-07-01
New adducts of lapachol with neat primary aliphatic amines were obtained in a solvent-free reaction in good to reasonable yields (52 to 88%), at room temperature. The new compounds containing a phenazine moiety were obtained from suitable functionalized aminoalkyl compounds, including ethanolamine, 3-propanolamine, 2-methoxy-ethylamine, 3-methoxy-propylamine, n-butylamine and 2-phenetylamine. (author)
Directory of Open Access Journals (Sweden)
Piyas Palit
2015-10-01
Full Text Available Tyre bead grade wire is used for tyre making application. The wire is used as reinforcement inside the polymer of tyre. The wire is available in different size/section such as 1.6–0.80 mm thin Cu coated wire. During tyre making operation at tyre manufacturer company, wire failed frequently. In this present study, different broken/defective wire samples were collected from wire mill for detailed investigation of the defect. The natures of the defects were localized and similar in nature. The fracture surface was of finger nail type. Crow feet like defects including button like surface abnormalities were also observed on the broken wire samples. The defect was studied at different directions under microscope. Different advanced metallographic techniques have been used for detail investigation. The analysis revealed that, white layer of surface martensite was formed and it caused the final breakage of wire. In this present study we have also discussed about the possible reason for the formation of such kind of surface martensite (hard-phase.
11. Breakage-reunion domain of Streptococcus pneumoniae topoisomerase IV: crystal structure of a gram-positive quinolone target.
Directory of Open Access Journals (Sweden)
Ivan Laponogov
Full Text Available The 2.7 A crystal structure of the 55-kDa N-terminal breakage-reunion domain of topoisomerase (topo IV subunit A (ParC from Streptococcus pneumoniae, the first for the quinolone targets from a gram-positive bacterium, has been solved and reveals a 'closed' dimer similar in fold to Escherichia coli DNA gyrase subunit A (GyrA, but distinct from the 'open' gate structure of Escherichia coli ParC. Unlike GyrA whose DNA binding groove is largely positively charged, the DNA binding site of ParC exhibits a distinct pattern of alternating positively and negatively charged regions coincident with the predicted positions of the grooves and phosphate backbone of DNA. Based on the ParC structure, a new induced-fit model for sequence-specific recognition of the gate (G segment by ParC has been proposed. These features may account for the unique DNA recognition and quinolone targeting properties of pneumococcal type II topoisomerases compared to their gram-negative counterparts.
12. uvrC gene function has no specific role in repair of N-2-aminofluorene adducts.
OpenAIRE
Bichara, M; Fuchs, R P
1987-01-01
In Escherichia coli, plasmid DNA modified with N-2-aminofluorene adducts survived equally well in wild-type, uvrA, or uvrB strains. Increased sensitivity was found in uvrC and uvrD strains. Moreover, N-2-aminofluorene-mediated toxicity in the uvrC background was reversed when an additional uvrA mutation was introduced into the strain.
13. The Influence of Rehydration on Breakage Susceptibility of Corn Kernels Hybrid Bc 492
OpenAIRE
Stjepan Pliestić
2002-01-01
Rehydrating corn kernels hybrid Bc 492 from 10% to 14,5% moisture content by adding distilled water or by mixing with higher moisture content corn kernels was effective in reducing breakage susceptibility. The extent to wich breakage susceptibility was reduced varied with the rehydration method and the amount of moisture added in a single rehydration step. Approximately 16 h were required for the rehydration process when adding water, and about 72 h for mixing samples. Mixing was a more effec...
14. Mechanical Properties of Photovoltaic Silicon in Relation to Wafer Breakage
Science.gov (United States)
Kulshreshtha, Prashant Kumar
This thesis focuses on the fundamental understanding of stress-modified crack-propagation in photovoltaic (PV) silicon in relation to the critical issue of PV silicon "wafer breakage". The interactions between a propagating crack and impurities/defects/residual stresses have been evaluated for consequential fracture path in a thin PV Si wafer. To investigate the mechanism of brittle fracture in silicon, the phase transformations induced by elastic energy released at a propagating crack-tip have been evaluated by locally stressing the diamond cubic Si lattice using a rigid Berkovich nanoindenter tip (radius ≈50 nm). Unique pressure induced phase transformations and hardness variations have been then related to the distribution of precipitates (O, Cu, Fe etc.), and the local stresses in the wafer. This research demonstrates for the first time the "ductile-like fracture" in almost circular crack path that significantly deviates from its energetically favorable crystallographic [110](111) system. These large diameter (≈ 200 mm) Si wafers were sliced to less than 180 microm thickness from a Czochralski (CZ) ingot that was grown at faster than normal growth rates. The vacancy (vSi) driven precipitation of oxygen at enhanced thermal gradients in the wafer core develops large localized stresses (upto 100 MPa) which we evaluated using Raman spectral analysis. Additional micro-FTIR mapping and microscopic etch pit measurements in the wafer core have related the observed crack path deviations to the presence of concentric ring-like distributions of oxygen precipitates (OPs). To replicate these "real-world" breakage scenarios and provide better insight on crack-propagation, several new and innovative tools/devices/methods have been developed in this study. An accurate quantitative profiling of local stress, phase changes and load-carrying ability of Si lattice has been performed in the vicinity of the controlled micro-cracks created using micro-indentations to represent
15. The role of nibrin in doxorubicin-induced apoptosis and cell senescence in Nijmegen Breakage Syndrome patients lymphocytes.
Directory of Open Access Journals (Sweden)
Olga Alster
Full Text Available Nibrin plays an important role in the DNA damage response (DDR and DNA repair. DDR is a crucial signaling pathway in apoptosis and senescence. To verify whether truncated nibrin (p70, causing Nijmegen Breakage Syndrome (NBS, is involved in DDR and cell fate upon DNA damage, we used two (S4 and S3R spontaneously immortalized T cell lines from NBS patients, with the founding mutation and a control cell line (L5. S4 and S3R cells have the same level of p70 nibrin, however p70 from S4 cells was able to form more complexes with ATM and BRCA1. Doxorubicin-induced DDR followed by cell senescence could only be observed in L5 and S4 cells, but not in the S3R ones. Furthermore the S3R cells only underwent cell death, but not senescence after doxorubicin treatment. In contrary to doxorubicin treatment, cells from all three cell lines were able to activate the DDR pathway after being exposed to γ-radiation. Downregulation of nibrin in normal human vascular smooth muscle cells (VSMCs did not prevent the activation of DDR and induction of senescence. Our results indicate that a substantially reduced level of nibrin or its truncated p70 form is sufficient to induce DNA-damage dependent senescence in VSMCs and S4 cells, respectively. In doxorubicin-treated S3R cells DDR activation was severely impaired, thus preventing the induction of senescence.
16. Covalent adduction of nitrogen mustards to model protein nucleophiles.
Science.gov (United States)
Thompson, Vanessa R; DeCaprio, Anthony P
2013-08-19
17. Redshift or adduct stabilization -- a computational study of hydrogen bonding in adducts of protonated carboxylic acids
DEFF Research Database (Denmark)
Olesen, Solveig Gaarn; Hammerum, Steen
2009-01-01
not always yield consistent predictions, as illustrated by the hydrogen bonds formed by the E and Z OH groups of protonated carboxylic acids. The delta-PA and the stabilization of a series of hydrogen bonded adducts indicate that the E OH group forms the stronger hydrogen bonds, whereas the bond length...... carboxylic acids are different. The OH bond length and IR redshift afford the better measure of hydrogen bond strength.......It is generally expected that the hydrogen bond strength in a D-H-A adduct is predicted by the difference between the proton affinities of D and A, measured by the adduct stabilization, and demonstrated by the IR redshift of the D-H bond stretching vibrational frequency. These criteria do...
18. Detection of DNA damage by Escherichia coli UvrB-binding competition assay is limited by the stability of the UvrB-DNA complex.
Science.gov (United States)
Routledge, M N; Allan, J M; Garner, R C
1997-07-01
19. Butachlor induced dissipation of mitochondrial membrane potential, oxidative DNA damage and necrosis in human peripheral blood mononuclear cells.
Science.gov (United States)
Dwivedi, Sourabh; Saquib, Quaiser; Al-Khedhairy, Abdulaziz A; Musarrat, Javed
2012-12-01
Butachlor is a systemic herbicide widely applied on rice, tea, wheat, beans and other crops; however, it concurrently exerts toxic effects on beneficial organisms like earthworms, aquatic invertebrates and other non-target animals including humans. Owing to the associated risk to humans, this chloroacetanilide class of herbicide was investigated with the aim to assess its potential for the (i) interaction with DNA, (ii) mitochondria membrane damage and DNA strand breaks and (iii) cell cycle arrest and necrosis in butachlor treated human peripheral blood mononuclear (PBMN) cells. Fluorescence quenching data revealed the binding constant (Ka=1.2×10(4)M(-1)) and binding capacity (n=1.02) of butachlor with ctDNA. The oxidative potential of butachlor was ascertained based on its capacity of inducing reactive oxygen species (ROS) and substantial amounts of promutagenic 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) adducts in DNA. Also, the discernible butachlor dose-dependent reduction in fluorescence intensity of a cationic dye rhodamine (Rh-123) and increased fluorescence intensity of 2',7'-dichlorodihydro fluorescein diacetate (DCFH-DA) in treated cells signifies decreased mitochondrial membrane potential (ΔΨm) due to intracellular ROS generation. The comet data revealed significantly greater Olive tail moment (OTM) values in butachlor treated PBMN cells vs untreated and DMSO controls. Treatment of cultured PBMN cells for 24h resulted in significantly increased number of binucleated micronucleated (BNMN) cells with a dose dependent reduction in the nuclear division index (NDI). The flow cytometry analysis of annexin V(-)/7-AAD(+) stained cells demonstrated substantial reduction in live population due to complete loss of cell membrane integrity. Overall the data suggested the formation of butachlor-DNA complex, as an initiating event in butachlor-induced DNA damage. The results elucidated the oxidative role of butachlor in intracellular ROS production, and
20. Micromechanics of breakage in sharp-edge particles using combined DEM and FEM
Institute of Scientific and Technical Information of China (English)
2008-01-01
By combining DEM (Discrete Element Method) and FEM (Finite Element Method),a model is established to simulate the breakage of two-dimensional sharp-edge particles,in which the simulated particles are assumed to have no cracks.Particles can,however,crush during different stages of the numerical analysis,if stress-based breakage criteria are fulfilled inside the particles.With this model,it is possible to study the influence of particle breakage on macro- and micro-mechanical behavior of simulated angular materials.Two series of tests,with and without breakable particles,are simulated under different confining pressures based on conditions of biaxial tests.The results,presented in terms of micromechanical behavior for different confining pressures,are compared with macroparameters.The influence of particle breakage on microstructure of sharp-edge materials is discussed and the related confining pressure effects are investigated.Breakage of particles in rockfill materials are shown to reduce the anisotropy coefficients of the samples and therefore their strength and dilation behaviors.
1. Absolute configuration, stability, and interconversion of 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine valine adducts and their phenylthiohydantoin derivatives
Directory of Open Access Journals (Sweden)
Xiao Jiang
2015-06-01
Full Text Available Pyrrolizidine alkaloid-containing plants are widespread in the world and probably the most common poisonous plants affecting livestock, wildlife, and humans. Pyrrolizidine alkaloids require metabolic activation to form dehydropyrrolizidine alkaloids that bind to cellular proteins and DNA leading to hepatotoxicity, genotoxicity, and tumorigenicity. At present, it is not clear how dehydropyrrolizidine alkaloids bind to cellular amino acids and proteins to induced toxicity. We previously reported that reaction of dehydromonocrotaline with valine generated four highly unstable 6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP-derived valine (DHP-valine adducts that upon reaction with phenyl isothiocyanate (PITC formed four DHP-valine-PITC adduct isomers. In this study, we report the absolute configuration and stability of DHP-valine and DHP-valine-PITC adducts, and the mechanism of interconversion between DHP-valine-PITC adducts.
2. Failure of intramedullary femoral nail with segmental breakage of distal locking bolts: a case report and review of the literature
Institute of Scientific and Technical Information of China (English)
Sameer Aggerwal; Nitesh Gahlot; Uttam C. Saini; Kamal Bali
2011-01-01
Breakage of locking bolts is an important cause of interlocking nail failure in femoral fractures. It usually occurs in the form of single breakage in one of the distal bolts of the nail or nail breakage around the distal locking hole. Here we report an unusual case of intramedullary femoral nail failure with segmental breakage of both the distal locking bolts. Such a scenario usually complicates further management. We successfully managed this case with exchange nailing without bone grafting. Here we briefly reviewed the literature regarding such an unusual presentation and discussed in detail the possible etiology of such a presentation and the management options when facing such a complex situation.
3. Analytical solution of population balance equation involving aggregation and breakage in terms of auxiliary equation method
Zehra Pinar; Abhishek Dutta; Guido Bény; Turgut Öziş
2015-01-01
This paper presents an effective analytical simulation to solve population balance equation (PBE), involving particulate aggregation and breakage, by making use of appropriate solution(s) of associated complementary equation via auxiliary equation method (AEM). Travelling wave solutions of the complementary equation of a nonlinear PBE with appropriately chosen parameters is taken to be analogous to the description of the dynamic behaviour of the particulate processes. For an initial proof-of-concept, a general case when the number of particles varies with respect to time is chosen. Three cases, i.e. (1) balanced aggregation and breakage, (2) when aggregation can dominate and (3) breakage can dominate, are selected and solved for their corresponding analytical solutions. The results are then compared with the available analytical solution, based on Laplace transform obtained from literature. In this communication, it is shown that the solution approach proposed via AEM is flexible and therefore more efficient than the analytical approach used in the literature.
4. Video-supported analysis of Beggiatoa filament growth, breakage, and movement
DEFF Research Database (Denmark)
Kamp, Anja; Røy, Hans; Schulz-Vogt, Heide N.
2008-01-01
A marine Beggiatoa sp. was cultured in semi-solid agar with opposing oxygen-sulfide gradients. Growth pattern, breakage of filaments for multiplication, and movement directions of Beggiatoa filaments in the transparent agar were investigated by time-lapse video recording. The initial doubling time...... of cells was 15.7 ± 1.3 h (mean ± SD) at room temperature. Filaments grew up to an average length of 1.7 ± 0.2 mm, but filaments of up to approximately 6 mm were also present. First breakages of filaments occurred approximately 19 h after inoculation, and time-lapse movies illustrated that a parent...
5. Intramolecular Tetrylene Lewis Adducts: Synthesis and Reactivity.
Science.gov (United States)
Schneider, Julia; Krebs, Kilian M; Freitag, Sarah; Eichele, Klaus; Schubert, Hartmut; Wesemann, Lars
2016-07-01
A series of benzyl(diphenylphosphino) and o-phenyl(diphenlyphosphino) substituted germylenes and plumbylenes were synthesized by nucleophilic substitution between the respective lithium reagent and tetrylene halide. The Lewis pairs were characterized by X-ray crystallography and NMR spectroscopy. The reactivity of the tetrylenes was investigated with respect to azide addition. In the germylene case, the germaniumimide was formed as the kinetically controlled product, which rearranges upon heating to give the phosphinimide. The stannylene and plumbylene derivatives react with adamantylazide to give the azide adducts. 1-Pentene reacts diastereoselectively with the phosphagermirane to give a cyclic addition product. Trimethysilylacetylene shows an addition with the benzylphosphino-substituted germylene and plumbylene to give the cycloheteropentene molecules. The addition product between phenylacetylene and the four membered Ge-P adduct shows after addition at room temperature a 1,4-phenylmigration to give a cyclic phosphine. Alkylnitrene insertion into a Ge-C bond of the alkyne addition product of the phosphagermirane was found in reaction with adamantylazide. PMID:27273819
6. ELISA-like Analysis of Cisplatinated DNA Using Magnetic Separation
OpenAIRE
Kristyna Smerkova; Marcela Vlcnovska; Simona Dostalova; Vedran Milosavljevic; Pavel Kopel; Tomas Vaculovic; Sona Krizkova; Marketa Vaculovicova; Vojtech Adam; Rene Kizek
2015-01-01
Cisplatin belongs to the most widely used cytostatic drugs. The determination of the presence of the DNA-cisplatin adducts may not only signal the guanine-rich regions but also monitor the interaction reaction between DNA and the drug in terms of speed of interaction. In this work, the combined advantages of magnetic particles-based isolation/purification with fluorescent properties of quantum dots (QDs) and antibodies targeted on specific recognition of DNA-cisplatin adducts are demonstra...
7. Synthesis and Photophysical Properties of C60-carbazole Adducts
Institute of Scientific and Technical Information of China (English)
YIN ,Gui(尹桂); YIN,Gui; MAO，Xin-Ping(毛新平); MAO,Xin-Ping; SUO，Zhi-Yong(锁志勇); SUO,Zhi-Yong; XU，Zheng(徐正); XU,Zheng
2001-01-01
Three C60-cartazole adducts have been synthesized by 1,3-dipolar cycloaddition reaction.Intramolecular energy/electron transfer from carbazole to C60 was observed by steady-state absorption and fluorescence spectra.The fluorescence spectra of these adducts were similau to each other and dependent on the excitation wavelength and solvent.
8. Adducted thumbs : A clinical clue to genetic diagnosis
NARCIS (Netherlands)
Verhagen, J. M. A.; Schrander-Stumpel, C. T. R. M.; Blezer, M. M. J.; Weber, J. W.; Schrander, J. J. P.; Rubio-Gozalbo, M. E.; Bakker, J. A.; Stegmann, A. P. A.; Vos, Y. J.; Frints, S. G. M.
2013-01-01
Adducted thumbs are an uncommon congenital malformation. It can be an important clinical clue in genetic syndromes, e. g. the L1 syndrome. A retrospective survey was performed including patients with adducted thumbs referred to the Department of Clinical Genetics between 1985 and 2011 by perinatolog
9. Adducted thumbs: a clinical clue to genetic diagnosis.
Science.gov (United States)
Verhagen, J M A; Schrander-Stumpel, C T R M; Blezer, M M J; Weber, J W; Schrander, J J P; Rubio-Gozalbo, M E; Bakker, J A; Stegmann, A P A; Vos, Y J; Frints, S G M
2013-03-01
Adducted thumbs are an uncommon congenital malformation. It can be an important clinical clue in genetic syndromes, e.g. the L1 syndrome. A retrospective survey was performed including patients with adducted thumbs referred to the Department of Clinical Genetics between 1985 and 2011 by perinatologists, (child) neurologists or paediatricians, in order to evaluate current knowledge on the genetic etiology of adducted thumbs. Twenty-five patients were included in this survey. Additional features were observed in 88% (22/25). In 25% (4/16) of the patients with adducted thumbs and congenital hydrocephalus L1CAM gene mutations were identified. One patient had a mosaic 5p13 duplication. Recommendations are made concerning the evaluation and genetic workup of patients with adducted thumbs. PMID:23220544
10. Risk assessment of DNA-reactive carcinogens in food
International Nuclear Information System (INIS)
Risk assessment of DNA-reactive carcinogens in food requires knowledge of the extent of DNA damage in the target organ which results from the competition between DNA adduct formation and repair. Estimates of DNA adduct levels can be made by direct measurement or indirectly as a consequence of their presence, for example, by tumor formation in animal models or exposed populations epidemiologically. Food-borne DNA-reactive carcinogens are present from a variety of sources. They are generally not intrinsically DNA-reactive but require bioactivation to DNA-reactive metabolites a process which may be modulated by the compound itself or the presence of other xenobiotics. A single DNA reactant may form several distinct DNA adducts each undergoing different rates of repair. Some DNA reactants may be photochemically activated or produce reactive oxygen species and thus indirect oxidative DNA damage. The levels of DNA adducts arising from exposures influenced by variations in the doses, the frequency with which an individual is exposed, and rates of DNA repair for specific adducts. Each adduct has a characteristic efficiency with which it induces mutations. Based on experience with the well-studied DNA-reactive food carcinogen aflatoxin B1 (AFB1), a limit of 20 ppb or ∼30 μg/day has been set and is considered a tolerable daily intake (TDI). Since AFB1 is considered a potent carcinogen, doses of 32P-postlabeling or the use of surrogates such as hemoglobin adducts, together with approaches to evaluate the results. A discussion of approaches to estimating possible threshold effects for DNA-reactive carcinogens is made
11. Suicide of EMT-6 tumor cells by decays from radioactively-labelled sensitizer adducts
International Nuclear Information System (INIS)
12. Aptamer optical biosensor without bio-breakage using upconversion nanoparticles as donors
NARCIS (Netherlands)
K. Song; X. Kong; X. Liu; Y. Zhang; Q. Zeng; L. Tu; Z. Shi; H. Zhang
2012-01-01
LRET-based optical biosensor of an aptamer-upconversion conjugate was constructed. It is demonstrated that photosensitized breakage and damage of aptamers are eliminated by employing UCNPs as donors, and the as-designed biosensor is specific and sensitive in the detection of ATP.
13. Feed Pellet and Corn Durability and Breakage During Repeated Elevator Handling
Science.gov (United States)
Pelleting of animal feeds is important for improved feeding efficiency and for convenience of handling. Pellet quality impacts the feeding benefits for the animals and pellet integrity during handling. To determine the effect of repeated handling on feed pellet breakage and durability, a 22.6-t (100...
14. The consequences of granulate heterogeneity towards breakage and attrition upon fluid-bed drying
NARCIS (Netherlands)
Nieuwmeyer, Florentine; Maarschalk, Kees van der Voort; Vromans, Herman
2008-01-01
High-shear granulated lactose granulates were dried in it fluid-bed dryer at various conditions. Granules were characterized by water content and size analysis. It is shown that the drying process is very dynamic in terms of growth and breakage phenomena. Granular size heterogeneity, composition and
15. Influence of the power law index on the fiber breakage during injection molding by numerical simulations
Science.gov (United States)
Desplentere, Frederik; Six, Wim; Bonte, Hilde; Debrabandere, Eric
2013-04-01
In predictive engineering for polymer processes, the proper prediction of material microstructure from known processing conditions and constituent material properties is a critical step forward properly predicting bulk properties in the finished composite. Operating within the context of long-fiber thermoplastics (LFT, length > 15mm) this investigation concentrates on the influence of the power law index on the final fiber length distribution within the injection molded part. To realize this, the Autodesk Simulation Moldflow Insight Scandium 2013 software has been used. In this software, a fiber breakage algorithm is available from this release on. Using virtual material data with realistic viscosity levels allows to separate the influence of the power law index on the fiber breakage from the other material and process parameters. Applying standard settings for the fiber breakage parameters results in an obvious influence on the fiber length distribution through the thickness of the part and also as function of position in the part. Finally, the influence of the shear rate constant within the fiber breakage model has been investigated illustrating the possibility to fit the virtual fiber length distribution to the possible experimentally available data.
16. The knee adduction moment during gait is associated with the adduction angle measured during computer-assisted total knee arthroplasty.
Science.gov (United States)
Roda, Richard D; Wilson, Janie L Astephen; Wilson, David A J; Richardson, Glen; Dunbar, Michael J
2012-06-01
Computer-assisted surgery can be used to measure 3-dimensional knee function during arthroplasty surgery; however, it is unknown if the movement of the knee measured during surgery is related to the in vitro, dynamic state of the knee joint, specifically the knee adduction moment during gait, which has been related to implant migration. The purpose of this study was to determine if the preoperative adduction moment is correlated with the knee abduction/adduction angle measured intraoperatively. A statistically significant correlation was found between the mean (r(2) = 0.59; P = .001) and peak (r(2) = 0.53; P = .003) preoperative knee adduction moment and the mean abduction/adduction angle measured intraoperatively. The association found in this study suggests the potential for incorporating functional information that relates to surgical outcome into surgical decision making using computer-assisted surgery.
17. Fast repair of dAMP hydroxyl radical adduct by verbascoside via electron transfer
Institute of Scientific and Technical Information of China (English)
石益民; 王文锋; 姚思德; 林维真; 韩镇辉; 师彦平; 贾忠建; 郑荣梁
1999-01-01
DNA damaged by oxygen radicals has been implicated as a causative event in a number of degenerative diseases, including cancer and aging. So it is very impotant to look for ways in which either oxygen radicals are scavenged prior to DNA damage or damaged DNA is repaired to supplement the cells’ inadequate repair capacity. The repair activity and its mechanism of verbaseoside, isolated from Pedicularis species, towards dAMP-OH·was studied with pulse radiolytic technique. On pulse irradiation of nitrous oxide saturated 2 mmol/L dAMP aqueous solution containing verbascoside, the transient absorption spectrum of the hydroxyl adduct of dAMP decayed with the formation of that of the phenoxyl radical of verbascoside well under 100 microseconds after electron pulse irradiation. The result indicated that dAMP hydroxyl adducts can be repaired by verbascoside. The rate constants of the repair reaction was deduced to be 5.9×108 dm3·mol-1·s-1. A deeper understanding of this new repair mechanism will undo
18. Protein adduct formation as a molecular mechanism in neurotoxicity.
Science.gov (United States)
Lopachin, Richard M; Decaprio, Anthony P
2005-08-01
19. Eliminating a Major Cause of Wire Drawing Breakage in A-15 High-Field Superconductors
Energy Technology Data Exchange (ETDEWEB)
Austen, Alfred R.
2003-05-20
Eliminating a Major Cause of Wire Drawing Breakage in A-15 High-Field Superconductors Phase 1 Summary Purpose of the research: The Phase 1 goal was to make a significant improvement in the wire drawing technology used for difficult to draw superconductor precursor composites. Many ductile Nb-Al and Nb-Sn precursor wire composites have experienced the onset of wire drawing breakage at about 1.5 mm diameter. Phase 1 focused on evaluating the role that precision rigid guidance of the wire into the drawing die and the hydrostatic stress state at the die entrance played in preventing wire breakage. Research carried out: The research performed depended upon the construction of both a mechanical wire guide and a hydrostatic pressure stiffened wire guidance system. Innovare constructed the two wire guidance systems and tested them for their ability to reduce wire drawing breakage. One set of hardware provided rigid alignment of the wires to their wire drawing die axes within 0.35 degrees using ''hydrostatic pressure stiffening'' to enable the precision guidance strategy to be implemented for these highly flexible small diameter wires. This apparatus was compared to a guide arrangement that used short span mechanical guide alignment with a misalignment limit of about 0.75 degrees. Four A-15 composite wires with breakage histories were drawn to evaluate the use of these wire guiding systems to reduce and/or eliminate wire breakage. Research findings and results: In Phase 1, a breakthrough in wire drawing technology for A-15 superconductor composites was achieved by dramatically limiting or eliminating breakage in four different A-15 composite precursor wire designs during the drawing of these very desirable composites that previously could not be drawn to near final size. Research results showed that the proposed Phase 1 mechanical wire guides were sufficiently effective and successful in eliminating breakage when used along with other advanced wire
20. Infrared spectroscopy of fullerene C60/anthracene adducts
CERN Document Server
2013-01-01
Recent Spitzer Space Telescope observations of several astrophysical environments such as Planetary Nebulae, Reflection Nebulae, and R Coronae Borealis stars show the simultaneous presence of mid-infrared features attributed to neutral fullerene molecules (i.e., C60) and polycyclic aromatic hydrocarbons (PAHs). If C60 fullerenes and PAHs coexist in fullerene-rich space environments, then C60 may easily form adducts with a number of different PAH molecules; at least with catacondensed PAHs. Here we present the laboratory infrared spectra (~2-25 um) of C60 fullerene and anthracene Dies-Alder mono- and bis-adducts as produced by sonochemical synthesis. We find that C60/anthracene Diels-Alder adducts display spectral features strikingly similar to those from C60 (and C70) fullerenes and other unidentified infrared emission features. Thus, fullerene-adducts - if formed under astrophysical conditions and stable/abundant enough - may contribute to the infrared emission features observed in fullerene-containing circu...
1. CFD simulation of shear-induced aggregation and breakage in turbulent Taylor-Couette flow.
Science.gov (United States)
Wang, Liguang; Vigil, R Dennis; Fox, Rodney O
2005-05-01
An experimental and computational investigation of the effects of local fluid shear rate on the aggregation and breakage of approximately 10 microm latex spheres suspended in an aqueous solution undergoing turbulent Taylor-Couette flow was carried out. First, computational fluid dynamics (CFD) simulations were performed and the flow field predictions were validated with data from particle image velocimetry experiments. Subsequently, the quadrature method of moments (QMOM) was implemented into the CFD code to obtain predictions for mean particle size that account for the effects of local shear rate on the aggregation and breakage. These predictions were then compared with experimental data for latex sphere aggregates (using an in situ optical imaging method). Excellent agreement between the CFD-QMOM and experimental results was observed for two Reynolds numbers in the turbulent-flow regime. PMID:15797411
2. Unidirectional valve malfunction by the breakage or malposition of disc - two cases report -
OpenAIRE
Lee, Chol; Lee, Kyu Chang; Kim, Hye Young; Kim, Mi Na; Choi, Eun Kyung; Kim, Ji-Sub; Lee, Won Sang; Lee, Myeong Jong; Kim, Hyung Tae
2013-01-01
Malfunction of the unidirectional valve in a breathing circuit system may cause hypercapnia from the rebreathing of expired gas, ventilation failure, and barotrauma. Capnography is a useful method for monitoring the integrity of the unidirectional valve. We experienced two cases of malfunction of a unidirectional valve which caused leakage and reverse flow, diagnosed early as a change of the capnographic waveform. One case was caused by expiratory unidirectional valve breakage. The other was ...
3. Effects of interfacial debonding and fiber breakage on static and dynamic buckling of fibers in matrices.
OpenAIRE
Serttunc, Metin
1992-01-01
Approved for public release; distribution is unlimited Analyses were performed for static and dynamic buckling of a continuous fiber embedded in a matrix and fiber breakage in order to determine the effects of interfacial debonding on the critical buckling load and the domain of instability. A beam on elastic foundation model was used for this study. The study showed that a local interfacial debonding between a fiber and a surrounding matrix resulted in an increase of the waveleng...
4. Structure and function of the translesion DNA polymerases and interactions with damaged DNA
Directory of Open Access Journals (Sweden)
F. Peter Guengerich
2015-03-01
Pre-steady-state kinetic analysis has been used to develop minimum kinetic models with rate constants of (the eight individual reaction steps in the catalytic cycle. The use of single-tryptophan mutants of Sulfolobus solfataricus Dpo4 and human (h pol κ has led to discernment of the steps for the conformation change (associated with dNTP binding and relocation and nucleotidyl transfer. X-ray crystal structures have been obtained for a number of the DNA adduct/DNA polymerase pairs in both binary and ternary complexes. Two isomeric etheno guanine adducts differ considerably in their interactions with DNA polymerases, explaining the base preferences. Further, even when several DNA polymerases cause the same mispairs with a single DNA adduct, the structural bases for this can differ considerably.
5. Analysis of heat-labile sites generated by reactions of depleted uranium and ascorbate in plasmid DNA.
Science.gov (United States)
Wilson, Janice; Young, Ashley; Civitello, Edgar R; Stearns, Diane M
2014-01-01
6. The Influence of Rehydration on Breakage Susceptibility of Corn Kernels Hybrid Bc 492
Directory of Open Access Journals (Sweden)
Stjepan Pliestić
2002-09-01
Full Text Available Rehydrating corn kernels hybrid Bc 492 from 10% to 14,5% moisture content by adding distilled water or by mixing with higher moisture content corn kernels was effective in reducing breakage susceptibility. The extent to wich breakage susceptibility was reduced varied with the rehydration method and the amount of moisture added in a single rehydration step. Approximately 16 h were required for the rehydration process when adding water, and about 72 h for mixing samples. Mixing was a more effective rehydration method, resulting in breakage susceptibility levels no higher than for a control samples dried to 14,5%. The effectiveness of rehydrating by adding distilled water was limited by stress cracks which developed during the rehydration process. Stress crack developed was minimized by rehydrating in moisture content steps of 1,5% or less when adding distilled water. Brekage susceptibility for the mixing samples was generally lower than for the corn kernels rehydrated by water addition. Values for the mixing samples ranged from 3,0 to 3,5%. This compares to a range of 3,3 to 6,3 for the water addition samples.
7. In vitro synthesis and purification of PhIP-deoxyguanosine and PhIP-DNA oligomer covalent complexes
Energy Technology Data Exchange (ETDEWEB)
Freeman, J.
1994-12-01
8. Modeling the conformational preference of the carbon-bonded covalent adduct formed upon exposure of 2'-deoxyguanosine to ochratoxin A.
Science.gov (United States)
Sharma, Purshotam; Manderville, Richard A; Wetmore, Stacey D
2013-05-20
The conformational flexibility of the C8-linked guanine adduct formed from attachment of ochratoxin A (OTA) was analyzed using a systematic computational approach and models ranging from the nucleobase to the adducted DNA helix. A focus was placed on the influence of the C8-modification of 2'-deoxyguanosine (dG) on the preferred relative arrangement of the nucleobase and the C8-substituent and, more importantly, the anti/syn conformational preference with respect to the glycosidic bond. Although OTA is twisted with respect to the base in the nucleobase model, addition of the deoxyribose sugar induces a further twist and restricts rotation about the C-C linkage due to close contacts between OTA and the sugar. The nucleoside model preferentially adpots a syn orientation (by 10-20 kJ mol(-1) depending on the OTA conformation) due to the presence of an O5'-H···N3 interaction. However, when this hydrogen bond is eliminated, which better mimics the DNA environment, a small (simulations and free energy analysis predict that both syn- and anti-conformations of OTB-dG are equally stable in helices when paired opposite cytosine. These results indicate that the adduct will likely adopt a syn conformation in an isolated nucleoside and nucleotide, while a mixture of syn and anti conformations will be observed in DNA duplexes. Since the syn conformation could stabilize base mismatches upon DNA replication or Z-DNA structures with varied biological outcomes, future computational and experimental work should elucidate the consequences of the conformational preference of this potentially harmful DNA lesion.
9. Tree species traits but not diversity mitigate stem breakage in a subtropical forest following a rare and extreme ice storm
OpenAIRE
Nadrowski, Karin; Pietsch, Katherina; Baruffol, Martin; Both, Sabine; Gutknecht, Jessica; Bruelheide, Helge; Heklau, Heike; Kahl, Anja; Kahl, Tiemo; Niklaus, Pascal; Kröber, Wenzel; Liu, Xiaojuan; Mi, Xiangcheng; Michalski, Stefan; von Oheimb, Goddert
2014-01-01
Future climates are likely to include extreme events, which in turn have great impacts on ecological systems. In this study, we investigated possible effects that could mitigate stem breakage caused by a rare and extreme ice storm in a Chinese subtropical forest across a gradient of forest diversity. We used Bayesian modeling to correct stem breakage for tree size and variance components analysis to quantify the influence of taxon, leaf and wood functional traits, and stand level properties o...
10. Crystalline guanine adducts of natural and synthetic trioxacarcins suggest a common biological mechanism and reveal a basis for the instability of trioxacarcin A.
Science.gov (United States)
Pröpper, Kevin; Dittrich, Birger; Smaltz, Daniel J; Magauer, Thomas; Myers, Andrew G
2014-09-15
X-ray crystallographic characterization of products derived from natural and fully synthetic trioxacarcins, molecules with potent antiproliferative effects, illuminates aspects of their reactivity and mechanism of action. Incubation of the fully synthetic trioxacarcin analog 3, which lacks one of the carbohydrate residues present in the natural product trioxacarcin A (1) as well as oxygenation at C2 and C4 yet retains potent antiproliferative effects, with the self-complimentary duplex oligonucleotide d(AACCGGTT) led to production of a crystalline covalent guanine adduct (6). Adduct 6 is closely analogous to gutingimycin (2), the previously reported guanine adduct derived from incubation of natural trioxacarcin A (1) with duplex DNA, suggesting that 3 and 1 likely share a common basis of cytotoxicity. In addition, we isolated a novel, dark-red crystalline guanine adduct (7) from incubation of trioxacarcin A itself with the self-complimentary duplex oligonucleotide d(CGTATACG). Crystallographic analysis suggests that 7 is an anthraquinone derivative, which we propose arises by a sequence of guanosine alkylation within duplex DNA, depurination, base-catalyzed elimination of the trioxacarcinose A carbohydrate residue, and oxidative rearrangement to form an anthraquinone. We believe that this heretofore unrecognized chemical instability of natural trioxacarcins may explain why trioxacarcin analogs lacking C4 oxygenation exhibit superior chemical stabilities yet, as evidenced by structure 3, retain a capacity to form lesions with duplex DNA. PMID:25176186
11. Genetic variation for susceptibility to storm-induced stem breakage in Solidago altissima: The role of stem height and morphology
Science.gov (United States)
Wise, Michael J.; Abrahamson, Warren G.
2010-07-01
While storms can have obvious ecological impacts on plants, plants' potential to respond evolutionarily to selection for increased resistance to storm damage has received little study. We took advantage of a thunderstorm with strong wind and hail to examine genetic variation for resistance to stem breakage in the herbaceous perennial Solidago altissima. The storm broke the apex of nearly 10% of 1883 marked ramets in a common-garden plot containing 26 genets of S. altissima. Plant genets varied 20-fold in resistance to breakage. Stem height was strongly correlated with resistance to breakage, with taller stems being significantly more susceptible. A stem's growth form (erect versus nodding) had no detectable effect on its resistance to breakage. Therefore, we rejected the hypothesis that a function of the nodding, or "candy-cane," morphology is protection of the apex from storm damage. The significant genetic variation in S. altissima for stem breakage suggests that this plant has the capacity to respond to selection imposed by storms - particularly through changes in mean stem height. Tradeoffs between breakage resistance and competition for light and pollinators may act to maintain a large amount of genetic variation in stem height.
12. A Synthetic Aptamer-Drug Adduct for Targeted Liver Cancer Therapy.
Directory of Open Access Journals (Sweden)
Thu Le Trinh
Full Text Available AS1411 (previously known as AGRO100 is a 26 nucleotide guanine-rich DNA aptamer which forms a guanine quadruplex structure. AS1411 has shown promising utility as a treatment for cancers in Phase I and Phase II clinical trials without causing major side-effects. AS1411 inhibits tumor cell growth by binding to nucleolin which is aberrantly expressed on the cell membrane of many tumors. In this study, we utilized a simple technique to conjugate a widely-used chemotherapeutic agent, doxorubicin (Dox, to AS1411 to form a synthetic Drug-DNA Adduct (DDA, termed as AS1411-Dox. We demonstrate the utility of AS1411-Dox in the treatment of hepatocellular carcinoma (HCC by evaluating the targeted delivery of Dox to Huh7 cells in vitro and in a murine xenograft model of HCC.
13. Covalent thiol adducts arising from reactive intermediates of cocaine biotransformation.
Science.gov (United States)
Schneider, Kevin J; DeCaprio, Anthony P
2013-11-18
14. Structural basis for recognition of 5'-phosphotyrosine adducts by TDP2
Energy Technology Data Exchange (ETDEWEB)
Shi, Ke; Kurahash, Kayo; Gao, Rui; Tsutakawa, Susan E.; Tainer, John A.; Pommier, Yves; Aihara, Hideki
2012-12-19
The DNA repair enzyme TDP2 resolves 5'-phosphotyrosyl-DNA adducts, and is responsible for resistance to anti-cancer drugs that target covalent topoisomerase-DNA complexes. TDP2 also participates in key signaling pathways during development and tumorigenesis, and cleaves a protein-RNA linkage during picornavirus replication. The crystal structure of zebrafish TDP2 bound to DNA reveals a deep and narrow basic groove that selectively accommodates the 5'-end of single-stranded DNA in a stretched conformation. The crystal structure of the full-length C. elegans TDP2 shows that this groove can also accommodate an acidic peptide stretch in vitro, with Glu and Asp sidechains occupying the DNA backbone phosphate binding sites. This extensive molecular mimicry suggests a potential mechanism for auto-regulation and how TDP2 may interact with phosphorylated proteins in signaling. Our study provides a framework to interrogate functions of TDP2 and develop inhibitors for chemotherapeutic and antiviral applications.
15. Partitioning of knee joint internal forces in gait is dictated by the knee adduction angle and not by the knee adduction moment.
Science.gov (United States)
2014-05-01
16. An Integrative Breakage Model of genome architecture, reshuffling and evolution: The Integrative Breakage Model of genome evolution, a novel multidisciplinary hypothesis for the study of genome plasticity.
Science.gov (United States)
Farré, Marta; Robinson, Terence J; Ruiz-Herrera, Aurora
2015-05-01
Our understanding of genomic reorganization, the mechanics of genomic transmission to offspring during germ line formation, and how these structural changes contribute to the speciation process, and genetic disease is far from complete. Earlier attempts to understand the mechanism(s) and constraints that govern genome remodeling suffered from being too narrowly focused, and failed to provide a unified and encompassing view of how genomes are organized and regulated inside cells. Here, we propose a new multidisciplinary Integrative Breakage Model for the study of genome evolution. The analysis of the high-level structural organization of genomes (nucleome), together with the functional constrains that accompany genome reshuffling, provide insights into the origin and plasticity of genome organization that may assist with the detection and isolation of therapeutic targets for the treatment of complex human disorders.
17. The importance of Pyr(6-4)Pyo adducts for survival and mutation induction in mammalian cells
International Nuclear Information System (INIS)
The biological consequences of a variety of DNA photoproducts are being studied in Chinese hamster ovary cells. By comparing the rate of induction of resistance to 6-thioguanine following irradiation at 254 nm and 313 nm, the authors find a similar mutation rate at equitoxic doses. Thus, enhanced mutation frequency does not appear to be a consequence of Pyr(6-4)Pyo adducts, which are produced at 254 nm but not at 313 nm. When the level of dimerised photoproducts is measured in a radioimmunoassay, Pyr(6-4)Pyo adducts, which are highly antigenic, are readily detected. By comparing the kinetics of removal of antibody-binding sites following irradiation at 254mn and 313 nm, it is evident that these lesions are repaired at the same rate as cyclobutane dimers
18. Chromatid interchanges at intrachromosomal telomeric DNA sequences
International Nuclear Information System (INIS)
Chinese hamster Don cells were exposed to X-rays, mitomycin C and teniposide (VM-26) to induce chromatid exchanges (quadriradials and triradials). After fluorescence in situ hybridization (FISH) of telomere sequences it was found that interstitial telomere-like DNA sequence arrays presented around five times more breakage-rearrangements than the genome overall. This high recombinogenic capacity was independent of the clastogen, suggesting that this susceptibility is not related to the initial mechanisms of DNA damage. (author)
19. Hair breakage index: an alternative tool for damage assessment of human hair.
Science.gov (United States)
2011-01-01
Improper hair care, mechanical abrasion, sun damage and chemical treatment changes the physical and morphological characteristics of hair. Several methods involving microscopic techniques, protein loss and assessment of tensile properties of the hair are generally used to evaluate the extent of damage caused. These are also used to determine the protective effect of hair care products. In the present investigation, the hair breakage index (HBI) was used as an alternative tool to determine the change in the properties of hair on weathering. HBI is a measure of the diameter of hair in a given cross sectional area of a marked region of hair on the scalp. The hair diameter changes as we progress towards the tip of the hair due to breakage. The ratio of the diameter of hair bundle in the distal region to the diameter of hair bundle in the proximal region from the scalp is used as an indicator of hair breakage. Higher HBI value is an indicator of hair damage.A study was conducted for duration of 16 weeks to assess the effect of weathering due to grooming practices on HBI values. The HBI and break stress for a group of 30 subjects were measured at baseline and at the end of 16 weeks (NU). Since Coconut oil (CNO) is known to have a positive benefit on tensile properties of hair, another matched group of 30 subjects who oiled their hair daily with CNO was used as a positive control (CNO). The HBI and break stress for this group were also measured at the baseline and after 16 weeks. It was observed that the HBI significantly increased in the NU group versus the CNO user group. The break stress also significantly decreased in the NU group suggesting its correlation with the HBI data. This study demonstrates the usefulness of HBI as a simple and effective tool for determining hair damage and its protection by different hair care products.
20. Heterogeneity of chromosomal breakage levels in epithelial tissue of ataxia-telangiectasia homozygotes and heterozygotes.
Science.gov (United States)
Rosin, M P; Ochs, H D; Gatti, R A; Boder, E
1989-09-01
The objective of this study was to obtain an estimate of the frequency distribution of spontaneous chromosomal breakage occurring in vivo in oral epithelia of 20 ataxia-telangiectasia patients (A-T homozygotes) and 26 parents (A-T obligate heterozygotes). Samples of exfoliated cells were obtained from each individual by swabbing the oral cavity and preparing air-dried slides. The percentage of exfoliated cells with micronuclei (MEC frequency) was used as an in vivo indicator for the amount of chromosomal breakage occurring in the tissue. As a population group, MEC frequencies of the A-T patients differed significantly from controls (mean for A-T patients, 1.51; for controls, 0.29; P less than 0.01). However, the values observed in individual patients ranged from MEC frequencies 10- to 12-fold above control values, to frequencies overlapping the upper values observed in the controls. Similarly, MEC frequencies observed among the A-T heterozygotes differed significantly from controls (mean for A-T heterozygotes, 1.02, mean for controls, 0.29; P less than 0.01). However, only 16 of the 26 individuals sampled had MEC frequencies greater than 0.5%, the 90th percentile for controls (compared with 16 of the 20 A-T patients examined). Of the A-T patients 11 had been previously assigned to complementation groups on the basis of sensitivity to x-irradiation. Seven of the patients belonged to group A and had MEC frequencies ranging from 0.3% to 1.9% with the remaining patients belonging to group C with MEC frequencies of 0.2% to 0.9%. The data presented in this paper suggest that although levels of spontaneous breakage in epithelial tissues of A-T patients and A-T obligate heterozygotes are often significantly elevated, this is not the case in all individuals.
1. AN EXPERIMENTAL STUDY ON THE MECHANISMAND PROCESS OF ROCK BREAKAGE WITHTHE PLANETARY CUTTER HEAD
Institute of Scientific and Technical Information of China (English)
顾大钊
1992-01-01
Based on the kinematic features of the Planetary Cutter Head (PCH),this paper deals with specificity of rock breakago with PCH, and the basic laws of this process are presented, The study shows that the axial force acting on the drilling face by a single cutter and the uniaxial compressive strength of the drilled rock have the marked influence on the penetrating depth of the cutter ,and the breakage of the drilling face with the PCH has two forms,the cyclical and the noncyclical. The major reason why the PCH has higher drilling efficiency than other cutter heads is that the PCH can make more free faces on the drilling face.
2. Dietary butyrylated high-amylose starch reduces azoxymethane-induced colonic O(6)-methylguanine adducts in rats as measured by immunohistochemistry and high-pressure liquid chromatography.
Science.gov (United States)
Le Leu, Richard K; Scherer, Benjamin L; Mano, Mark T; Winter, Jean M; Lannagan, Tamsin; Head, Richard J; Lockett, Trevor; Clarke, Julie M
2016-09-01
O(6)-methyl guanine (O(6)MeG) adducts are major toxic, promutagenic, and procarcinogenic adducts involved in colorectal carcinogenesis. Resistant starch and its colonic metabolite butyrate are known to protect against oncogenesis in the colon. In this study, we hypothesized that a dietary intervention that specifically delivers butyrate to the large bowel (notably butyrylated high-amylose maize starch [HAMSB]) would reduce colonic levels of O(6)MeG in rats shortly after exposure to the deoxyribonucleic acid (DNA) alkylating agent azoxymethane (AOM) when compared with a low-amylose maize starch (LAMS). A further objective was to validate an immunohistochemistry (IHC) method for quantifying O(6)MeG against a high-performance liquid chromatography method using fluorescence and diode array detection. Rats were fed either LAMS or HAMSB diets for 4 weeks followed by a single injection of AOM or saline and killed 6 hours later. After AOM exposure, both IHC and high-performance liquid chromatography method using fluorescence and diode array detection measured a substantially increased quantity of DNA adducts in the colon (P<.001). Both techniques demonstrated equally that consumption of HAMSB provided a protective effect by reducing colonic adduct load compared with the LAMS diet (P<.05). In addition, IHC allowed visualization of the O(6)MeG distribution, where adduct load was reduced in the lower third of the crypt compartment in HAMSB-fed rats (P=.036). The apoptotic response to AOM was higher in the HAMSB-fed rats (P=.002). In conclusion, the reduction in O(6)MeG levels and enhancement of the apoptotic response to DNA damage in the colonic epithelium through consumption of HAMSB provide mechanistic insights into how HAMSB protects against colorectal tumorigenesis. PMID:27632918
3. Study on the Interaction between Antitumor Drug Daunomycin and DNA
Institute of Scientific and Technical Information of China (English)
CHENG Gui-Fang; ZHAO Jie; TU Yong-Hua; HE Pin-Gang; FANG Yu-Zhi
2005-01-01
A detection of anthracycline antitumor drug daunomycin (DNR) reacting with DNA in simulate metabolism in vitro has been made. It was found that DNR could react with DNA to form DNR-DNA adducts. The adduct compositions of DNR with fish sperm DNA and thermally denaturated DNA were determined. The equilibrium association constant K of DNR with fish sperm DNA is 1.98 × 105 L/mol and that of DNR with denaturated DNA is 2.29 × 104 L/mol. Semiquinone free radicals, metabolic products of DNR, can destroy both fish sperm DNA and its thermally denaturated DNA. It is verified by hyperchromic effect increase observed in UV spectrum and AFM experiments. The mechanism of DNA degradation has also been investigated. Results obtained allow one to explain the reason of side effect of anthracycline drug and give the way to depress, which were of clinical significance.
4. Parametric Study on Responses of a Self-Anchored Suspension Bridge to Sudden Breakage of a Hanger
Directory of Open Access Journals (Sweden)
Wenliang Qiu
2014-01-01
Full Text Available The girder of self-anchored suspension bridge is subjected to large compression force applied by main cables. So, serious damage of the girder due to breakage of hangers may cause the collapse of the whole bridge. With the time increasing, the hangers may break suddenly for their resistance capacities decrease due to corrosion. Using nonlinear static and dynamic analysis methods and adopting 3D finite element model, the responses of an actual self-anchored suspension bridge to sudden breakage of hangers are studied in this paper. The results show that the sudden breakage of a hanger causes violent vibration and large changes in internal forces of the bridge. In the process of the vibration, the maximum tension of hanger produced by breakage of a hanger exceeds 2.22 times its initial value, and the reaction forces of the bearings increase by more than 1.86 times the tension of the broken hanger. Based on the actual bridge, the influences of some factors including flexural stiffness of girder, torsion stiffness of girder, flexural stiffness of main cable, weight of girder, weight of main cable, span to sag ratio of main cable, distance of hangers, span length, and breakage time of hanger on the dynamic responses are studied in detail, and the influencing extent of the factors is presented.
5. Parametric study on responses of a self-anchored suspension bridge to sudden breakage of a hanger.
Science.gov (United States)
Qiu, Wenliang; Jiang, Meng; Huang, Cailiang
2014-01-01
The girder of self-anchored suspension bridge is subjected to large compression force applied by main cables. So, serious damage of the girder due to breakage of hangers may cause the collapse of the whole bridge. With the time increasing, the hangers may break suddenly for their resistance capacities decrease due to corrosion. Using nonlinear static and dynamic analysis methods and adopting 3D finite element model, the responses of an actual self-anchored suspension bridge to sudden breakage of hangers are studied in this paper. The results show that the sudden breakage of a hanger causes violent vibration and large changes in internal forces of the bridge. In the process of the vibration, the maximum tension of hanger produced by breakage of a hanger exceeds 2.22 times its initial value, and the reaction forces of the bearings increase by more than 1.86 times the tension of the broken hanger. Based on the actual bridge, the influences of some factors including flexural stiffness of girder, torsion stiffness of girder, flexural stiffness of main cable, weight of girder, weight of main cable, span to sag ratio of main cable, distance of hangers, span length, and breakage time of hanger on the dynamic responses are studied in detail, and the influencing extent of the factors is presented.
6. Tree species traits but not diversity mitigate stem breakage in a subtropical forest following a rare and extreme ice storm.
Directory of Open Access Journals (Sweden)
Full Text Available Future climates are likely to include extreme events, which in turn have great impacts on ecological systems. In this study, we investigated possible effects that could mitigate stem breakage caused by a rare and extreme ice storm in a Chinese subtropical forest across a gradient of forest diversity. We used Bayesian modeling to correct stem breakage for tree size and variance components analysis to quantify the influence of taxon, leaf and wood functional traits, and stand level properties on the probability of stem breakage. We show that the taxon explained four times more variance in individual stem breakage than did stand level properties; trees with higher specific leaf area (SLA were less susceptible to breakage. However, a large part of the variation at the taxon scale remained unexplained, implying that unmeasured or undefined traits could be used to predict damage caused by ice storms. When aggregated at the plot level, functional diversity and wood density increased after the ice storm. We suggest that for the adaption of forest management to climate change, much can still be learned from looking at functional traits at the taxon level.
7. UNUSUALLY STABLE ADDUCT BETWEEN METHANOLYZED AMOXICILLIN OR AMPICILLIN AND THEIR DIKETOPIPERAZINE DERIVATIVES.
Science.gov (United States)
Kosińska, Katarzyna; Frański, Rafał; Frańska, Magdalena
2016-01-01
Amoxicillin and ampicillin were subjected to methanolysis. As expected, the methanolysis products were observed by HPLC-ESI-MS. Besides these products, diketopiperazine derivatives were also detected. Additionally, unusually stable adduct formed between the products of methanolysis and diketopiperazine derivatives was also identified. Analogical adducts were detected when ethanolysis was performed instead of methanolysis. HPLC-ESI-MS analysis of the separated adducts confirmed that the adducts were composed of methanolysis products and diketopiperazine derivatives.
8. Breakage of Needle during Intracavernosal Injection and Use of Portable Ultrasound Guidance for Removal
Directory of Open Access Journals (Sweden)
Wayland Hsiao
2013-01-01
Full Text Available Purpose. Intracavernosal self-injection (ICI was first described in 1982, and remains a viable therapy for erectile dysfunction. However, intracorporal needle breakage can be a rare complication of therapy. We report a rare complication of intracorporal needle breakage and a retention of a 30-gauge needle in a 42-year-old paraplegic man. We discuss our experience in using portable high-frequency ultrasound intraoperatively to visualize and guide removal of a retained ICI needle. Materials and Methods. Review of case and ultrasound technique are presented. Results. Using intraoperative ultrasound imaging, the retained intracorporal needle was successfully removed from the patient's penis without any complications. Follow-up ultrasonography and X-ray confirmed complete removal of the needle. Conclusions. We report on the successful implementation and use of a portable high-frequency ultrasound probe to visualize a retained intracorporal needle inside the penis and its use to guide removal. Given the rapid proliferation of portable ultrasound machines in the operating room and out in the field, we expect these imaging techniques to become routine, especially in urological emergencies.
9. CFD simulation of aggregation and breakage processes in laminar Taylor-Couette flow.
Science.gov (United States)
Wang, L; Marchisio, D L; Vigil, R D; Fox, R O
2005-02-15
An experimental and computational investigation of the effects of local fluid shear rate on the aggregation and breakage of approximately 10 microm latex spheres suspended in an aqueous solution undergoing laminar Taylor-Couette flow was carried out according to the following program. First, computational fluid dynamics (CFD) simulations were performed and the flow field predictions were validated with data from particle image velocimetry experiments. Subsequently, the quadrature method of moments (QMOM) was implemented into the CFD code to obtain predictions for mean particle size that account for the effects of local shear rate on the aggregation and breakage. These predictions were then compared with experimental data for latex sphere aggregates (using an in situ optical imaging method) and with predictions using spatial average shear rates. The mean particle size evolution predicted by CFD and QMOM using appropriate kinetic expressions that incorporate information concerning the particle morphology (fractal dimension) and the local fluid viscous effects on aggregation collision efficiency match well with the experimental data. PMID:15589543
10. [sup 129]I Moessbauer spectroscopic study of metallocene-iodine adducts
Energy Technology Data Exchange (ETDEWEB)
Nakashima, Satoru (Dept. of Chemistry, Faculty of Science, Hiroshima Univ. (Japan)); Sakai, Hiroshi (Dept. of Chemistry, Faculty of Science, Hiroshima Univ. (Japan)); Watanabe, Masanobu (Dept. of Chemistry, Coll. of Arts and Sciences, Univ. of Tokyo (Japan)); Maeda, Yutaka (Research Reactor Inst., Kyoto Univ., Osaka (Japan))
1994-05-01
A [sup 129]I Moessbauer spectroscopic study of iodine adducts of ferrocenophane, biruthenocene, and osmocene is reported. The spectra show the existence of iodine bonded to the central metals of metallocenes in addition to triiodide anions. The valence state of iron in the ferrocenophane-iodine adduct is the same as those of ruthenium and osmium in their adducts. (orig.)
11. Flanking bases influence the nature of DNA distortion by platinum 1,2-intrastrand (GG cross-links.
Directory of Open Access Journals (Sweden)
Full Text Available The differences in efficacy and molecular mechanisms of platinum anti-cancer drugs cisplatin (CP and oxaliplatin (OX are thought to be partially due to the differences in the DNA conformations of the CP and OX adducts that form on adjacent guanines on DNA, which in turn influence the binding of damage-recognition proteins that control downstream effects of the adducts. Here we report a comprehensive comparison of the structural distortion of DNA caused by CP and OX adducts in the TGGT sequence context using nuclear magnetic resonance (NMR spectroscopy and molecular dynamics (MD simulations. When compared to our previous studies in other sequence contexts, these structural studies help us understand the effect of the sequence context on the conformation of Pt-GG DNA adducts. We find that both the sequence context and the type of Pt-GG DNA adduct (CP vs. OX play an important role in the conformation and the conformational dynamics of Pt-DNA adducts, possibly explaining their influence on the ability of many damage-recognition proteins to bind to Pt-DNA adducts.
12. Triphosgene mediated chlorination of Baylis-Hillman adducts
Narender Reddy Thatikonda; Naga Sesha Sai Pavan Kumar Chebolu; Mahendar Budde; Jayathirtha Rao Vaidya
2012-03-01
An efficient method for the preparation of allyl chlorides from Baylis-Hillman adducts has been developed using triphosgene/pyridine system. This method is best illustrated by its advantages like operational simplicity, excellent yields, short reaction time, simple procedure and stereoselectivity.
13. Stability, accumulation and cytotoxicity of an albumin-cisplatin adduct
DEFF Research Database (Denmark)
Møller, Charlotte; Tastesen, Hanne Sørup; Gammelgaard, Bente;
2010-01-01
The accumulation and cytotoxicity of a 10 µmol L¿¹ equimolar human serum albumin-cisplatin adduct (HSA-Pt) was investigated in suspension Ehrlich Ascites Tumor Cells (EATC) and adherent Ehrlich Lettré Ascites Cells (Lettré). HSA-Pt did not induce apoptosis nor was it taken up by the cells to any ...
14. Frameshift Deletion by Sulfolobus solfataricus P2 DNA Polymerase Dpo4 T239W Is Selective for Purines and Involves Normal Conformational Change Followed by Slow Phosphodiester Bond Formation*
OpenAIRE
Zhang, Huidong; Beckman, Jeff W.; Guengerich, F. Peter
2009-01-01
The human DNA polymerase κ homolog Sulfolobus solfataricus DNA polymerase IV (Dpo4) produces “−1” frameshift deletions while copying unmodified DNA and, more frequently, when bypassing DNA adducts. As judged by steady-state kinetics and mass spectrometry, bypass of purine template bases to produce these deletions occurred rarely but with 10-fold higher frequency than with pyrimidines. The DNA adduct 1,N2-etheno-2′-deoxyguanosine, with a larger stacking surface than canonical purines, showed t...
15. Effects of particle size and confining pressure on breakage factor of rockfill materials using medium triaxial test
Institute of Scientific and Technical Information of China (English)
Ashok Kumar Gupta
2016-01-01
Rockfill dams are mostly constructed using blasted rockfill materials obtained by blasting rocks or al-luvial rockfill materials collected from the riverbeds. Behaviors of rockfill materials and their charac-terization significantly depend on breakage factor observed during triaxial loading. In this paper, two modeled rockfill materials are investigated by using medium triaxial cell. Drained triaxial tests are conducted on various sizes of modeled rockfill materials used in the two dams, and test data are analyzed accordingly. Breakage factor of rockfill material is studied and the effects of particle size and confining pressure on breakage factor are investigated using medium triaxial cell as many researchers have already conducted investigation using large triaxial cell.
16. Application of the adductome approach to assess intertissue DNA damage variations in human lung and esophagus
International Nuclear Information System (INIS)
17. Quantification of Carnosine-Aldehyde Adducts in Human Urine.
Science.gov (United States)
da Silva Bispo, Vanderson; Di Mascio, Paolo; Medeiros, Marisa
2014-10-01
Lipid peroxidation generates several reactive carbonyl species, including 4-hydroxy-2-nonenal (HNE), acrolein (ACR), 4-hydroxy-2-hexenal (HHE) and malondialdehyde. One major pathwayof aldehydes detoxification is through conjugation with glutathione catalyzed by glutathione-S-transferases or, alternatively, by conjugation with endogenous histidine containing dipeptides, such as carnosine (CAR). In this study, on-line reverse-phase high-performance liquid chromatography (HPLC) separation with tandem mass spectrometry detection was utilized for the accurate quantification of CAR- ACR, CAR-HHE and CAR-HNE adducts in human urinary samples from non-smokers young adults. Standard adducts were prepared and isolated by HPLC. The results showed the presence of a new product from the reaction of CAR with ACR. This new adduct was completely characterized by HPLC/MS-MSn, 1H RMN, COSY and HSQC. The new HPLC/MS/MS methodology employing stable isotope-labeled internal standards (CAR-HHEd5 and CAR-HNEd11) was developed for adducts quantification. This methodology permits quantification of 10pmol CAR-HHE and 1pmol of CAR-ACR and CAR-HNE. Accurate determinations in human urine sample were performed and showed 4.65±1.71 to CAR-ACR, 5.13±1.76 to CAR-HHE and 5.99±3.19nmol/mg creatinine to CAR-HNE. Our results indicate that carnosine pathways can be an important detoxification route of a, ß -unsaturated aldehydes. Moreover, carnosine adducts may be useful as redox stress indicator. PMID:26461323
18. The verification of the Taylor-expansion moment method in solving aerosol breakage
Directory of Open Access Journals (Sweden)
Yu Ming-Zhou
2012-01-01
Full Text Available The combination of the method of moment, characterizing the particle population balance, and the computational fluid dynamics has been an emerging research issue in the studies on the aerosol science and on the multiphase flow science. The difficulty of solving the moment equation arises mainly from the closure of some fractal moment variables which appears in the transform from the non-linear integral-differential population balance equation to the moment equations. Within the Taylor-expansion moment method, the breakage-dominated Taylor-expansion moment equation is first derived here when the symmetric fragmentation mechanism is involved. Due to the high efficiency and the high precision, this proposed moment model is expected to become an important tool for solving population balance equations.
19. The principle of second generation wavelet for milling cutter breakage detection
Institute of Scientific and Technical Information of China (English)
2009-01-01
Performance degradation or failure of manufacturing equipment will badly influence machining quality.Because of discontinuousness of the milling process,dynamic signals produced in the milling process become non-stationary.This paper indicates that the essence of SGW(second generation wavelet) transform in non-stationary signal processing is the mathematics principle of inner product transform of a dynamic signal with basis functions.Namely,by means of the inner product operation of a signal with basis functions containing scale function and wavelet function,signal decomposition and reconstruction are obtained.Acoustic emission signals generated in the milling processes of a CNC machine were analyzed by using the basis functions of SGW which are oscillation,decay and compact support.The features of end milling cutter breakage have been extracted,and the influences on machining surface quality have been identified effectively,which provide scientific bases for fault diagnosis,error tracing and quality control.
20. The principle of second generation wavelet for milling cutter breakage detection
Institute of Scientific and Technical Information of China (English)
HE ZhengJia; CAO HongRui; LI Zhen; ZI YanYang; CHEN XueFeng
2009-01-01
Performance degradation or failure of manufacturing equipment will badly influence machining quality.Because of discontinuousness of the milling process, dynamic signals produced in the milling process become non-stationary. This paper indicates that the essence of SGW (second generation wavelet)transform in non-stationary signal processing is the mathematics principle of inner product transform of a dynamic signal with basis functions. Namely, by means of the inner product operation of a signal with basis functions containing scale function and wavelet function, signal decomposition and recon-struction are obtained. Acoustic emission signals generated in the milling processes of a CNC machine were analyzed by using the basis functions of SGW which are oscillation, decay and compact support.The features of end milling cutter breakage have been extracted, and the influences on machining surface quality have been identified effectively, which provide scientific bases for fault diagnosis, error tracing and quality control.
1. Cypripedium calceolus germination in situ: seed longevity, and dormancy breakage by long incubation and cold winters
Directory of Open Access Journals (Sweden)
Hanne N. Rasmussen
2012-02-01
Full Text Available A successful in situ germination experiment with Cypripedium calceolus, the European Lady’s slipper, is reported here for the first time. The seeds originated from controlled pollinations within and between two closely related Danish populations. The seeds were sown ripe in seed packets in proximity of mother plants. Germination was first observed after 4.5 y in the ground, following two successive cold and snowy winters, and only in one population. Seedlings expanded through the sides of the broken testa and were hair-less. A corresponding set of seeds, germinated in vitro as asymbiotic controls, responded positively to repeated cold stratifications after long incubation, suggesting that time (leaching? and chilling are dormancy breakage factors.
2. An Intensified Vibratory Milling Process for Enhancing the Breakage Kinetics during the Preparation of Drug Nanosuspensions.
Science.gov (United States)
Li, Meng; Zhang, Lu; Davé, Rajesh N; Bilgili, Ecevit
2016-04-01
3. Real-time direct and diffraction X-ray imaging of irregular silicon wafer breakage
Directory of Open Access Journals (Sweden)
Alexander Rack
2016-03-01
Full Text Available Fracture and breakage of single crystals, particularly of silicon wafers, are multi-scale problems: the crack tip starts propagating on an atomic scale with the breaking of chemical bonds, forms crack fronts through the crystal on the micrometre scale and ends macroscopically in catastrophic wafer shattering. Total wafer breakage is a severe problem for the semiconductor industry, not only during handling but also during temperature treatments, leading to million-dollar costs per annum in a device production line. Knowledge of the relevant dynamics governing perfect cleavage along the {111} or {110} faces, and of the deflection into higher indexed {hkl} faces of higher energy, is scarce due to the high velocity of the process. Imaging techniques are commonly limited to depicting only the state of a wafer before the crack and in the final state. This paper presents, for the first time, in situ high-speed crack propagation under thermal stress, imaged simultaneously in direct transmission and diffraction X-ray imaging. It shows how the propagating crack tip and the related strain field can be tracked in the phase-contrast and diffracted images, respectively. Movies with a time resolution of microseconds per frame reveal that the strain and crack tip do not propagate continuously or at a constant speed. Jumps in the crack tip position indicate pinning of the crack tip for about 1–2 ms followed by jumps faster than 2–6 m s−1, leading to a macroscopically observed average velocity of 0.028–0.055 m s−1. The presented results also give a proof of concept that the described X-ray technique is compatible with studying ultra-fast cracks up to the speed of sound.
4. Real-time direct and diffraction X-ray imaging of irregular silicon wafer breakage.
Science.gov (United States)
Rack, Alexander; Scheel, Mario; Danilewsky, Andreas N
2016-03-01
Fracture and breakage of single crystals, particularly of silicon wafers, are multi-scale problems: the crack tip starts propagating on an atomic scale with the breaking of chemical bonds, forms crack fronts through the crystal on the micrometre scale and ends macroscopically in catastrophic wafer shattering. Total wafer breakage is a severe problem for the semiconductor industry, not only during handling but also during temperature treatments, leading to million-dollar costs per annum in a device production line. Knowledge of the relevant dynamics governing perfect cleavage along the {111} or {110} faces, and of the deflection into higher indexed {hkl} faces of higher energy, is scarce due to the high velocity of the process. Imaging techniques are commonly limited to depicting only the state of a wafer before the crack and in the final state. This paper presents, for the first time, in situ high-speed crack propagation under thermal stress, imaged simultaneously in direct transmission and diffraction X-ray imaging. It shows how the propagating crack tip and the related strain field can be tracked in the phase-contrast and diffracted images, respectively. Movies with a time resolution of microseconds per frame reveal that the strain and crack tip do not propagate continuously or at a constant speed. Jumps in the crack tip position indicate pinning of the crack tip for about 1-2 ms followed by jumps faster than 2-6 m s(-1), leading to a macroscopically observed average velocity of 0.028-0.055 m s(-1). The presented results also give a proof of concept that the described X-ray technique is compatible with studying ultra-fast cracks up to the speed of sound. PMID:27006774
5. EMG evaluation of hip adduction exercises for soccer players
DEFF Research Database (Denmark)
Serner, Andreas; Jakobsen, Markus Due; Andersen, Lars Louis;
2014-01-01
traditional and two new hip adduction exercises. Additionally, to analyse muscle activation of gluteals and abdominals. MATERIALS AND METHODS: 40 healthy male elite soccer players, training >5 h a week, participated in the study. Muscle activity using surface electromyography (sEMG) was measured bilaterally...... for the adductor longus during eight hip adduction strengthening exercises and peak EMG was normalised (nEMG) using an isometric maximal voluntary contraction (MVC) as reference. Furthermore, muscle activation of the gluteus medius, rectus abdominis and the external abdominal obliques was analysed during...... the exercises. RESULTS: There were large differences in peak nEMG of the adductor longus between the exercises, with values ranging from 14% to 108% nEMG (pEMG results for the gluteals...
6. Cooperative cluster formation, DNA bending and base-flipping by O6-alkylguanine-DNA alkyltransferase
OpenAIRE
Tessmer, Ingrid; Melikishvili, Manana; Fried, Michael G.
2012-01-01
O6-Alkylguanine-DNA alkyltransferase (AGT) repairs mutagenic O6-alkylguanine and O4-alkylthymine adducts in DNA, protecting the genome and also contributing to the resistance of tumors to chemotherapeutic alkylating agents. AGT binds DNA cooperatively, and cooperative interactions are likely to be important in lesion search and repair. We examined morphologies of complexes on long, unmodified DNAs, using analytical ultracentrifugation and atomic force microscopy. AGT formed clusters of ≤11 pr...
7. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos
International Nuclear Information System (INIS)
Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates
8. NEW HYDROGENOXALATO ADDUCTS AND MALONATO COMPLEX: SYNTHESIS AND SPECTROSCOPIC STUDIES
Directory of Open Access Journals (Sweden)
2014-08-01
Full Text Available Two new hydrogenoxalato and one malonato adduct and complex have been synthesized and studied by infrared and NMR spectroscopies. The suggested structures are discrete, the hydrogenoxalate behaving as a monodentate ligand or only involved in hydrogen bonding, the environment around the tin (IV centre being tetrahedral or trigonal bipyramidal. The malonate anion is a monodentate ligand. In all the suggested structures, when extra hydrogen bonds are considered, supramolecular architectures are obtained.
9. PHOSPHATO AND PHOSPHONATO ADDUCTS: SYNTHESIS AND SPECTROSCOPIC STUDY
Directory of Open Access Journals (Sweden)
2014-05-01
Full Text Available Two new adducts have been synthesized and studied by infrared and NMR spectroscopy. The suggested structures are discrete or of infinite chain type with a phosphate behaving as a bidentate ligand, a phosphonate acting as a monodentate ligand, the environments around the tin centre being tetrahedral or trigonal bipyramidal. In all the studied compounds, supramolecular architectures are obtained when hydrogen bonds are considered.
10. Ion Pairs or Neutral Molecule Adducts? Cooperativity in Hydrogen Bonding
Science.gov (United States)
DeKock, Roger L.; Schipper, Laura A.; Dykhouse, Stephanie C.; Heeringa, Lee P.; Brandsen, Benjamin M.
2009-01-01
We performed theoretical studies on the systems NH[subscript 3] times HF times mH[subscript 2]O, NH[subscript 3] times HCl times mH[subscript 2]O, with m = 0, 1, 2, and 6. The molecules with m = 0 form hydrogen-bonded adducts with little tendency to form an ion-pair structure. The molecule NH[subscript 3] times HCl times H[subscript 2]O cannot be…
11. Protein tyrosine adduct in humans self-poisoned by chlorpyrifos
Energy Technology Data Exchange (ETDEWEB)
Li, Bin, E-mail: binli@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Eyer, Peter, E-mail: peter.eyer@lrz.uni-muenchen.de [Walther-Straub-Institut Für Pharmakologie und Toxikologie, Ludwig-Maximilians-Universität München, 80336 München (Germany); Eddleston, Michael, E-mail: M.Eddleston@ed.ac.uk [Clinical Pharmacology Unit, University of Edinburgh, Edinburgh (United Kingdom); Jiang, Wei, E-mail: wjiang@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Schopfer, Lawrence M., E-mail: lmschopf@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Lockridge, Oksana, E-mail: olockrid@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States)
2013-06-15
Studies of human cases of self-inflicted poisoning suggest that chlorpyrifos oxon reacts not only with acetylcholinesterase and butyrylcholinesterase but also with other blood proteins. A favored candidate is albumin because in vitro and animal studies have identified tyrosine 411 of albumin as a site covalently modified by organophosphorus poisons. Our goal was to test this proposal in humans by determining whether plasma from humans poisoned by chlorpyrifos has adducts on tyrosine. Plasma samples from 5 self-poisoned humans were drawn at various time intervals after ingestion of chlorpyrifos for a total of 34 samples. All 34 samples were analyzed for plasma levels of chlorpyrifos and chlorpyrifos oxon (CPO) as a function of time post-ingestion. Eleven samples were analyzed for the presence of diethoxyphosphorylated tyrosine by mass spectrometry. Six samples yielded diethoxyphosphorylated tyrosine in pronase digests. Blood collected as late as 5 days after chlorpyrifos ingestion was positive for CPO-tyrosine, consistent with the 20-day half-life of albumin. High plasma CPO levels did not predict detectable levels of CPO-tyrosine. CPO-tyrosine was identified in pralidoxime treated patients as well as in patients not treated with pralidoxime, indicating that pralidoxime does not reverse CPO binding to tyrosine in humans. Plasma butyrylcholinesterase was a more sensitive biomarker of exposure than adducts on tyrosine. In conclusion, chlorpyrifos oxon makes a stable covalent adduct on the tyrosine residue of blood proteins in humans who ingested chlorpyrifos. - Highlights: • Chlorpyrifos-poisoned patients have adducts on protein tyrosine. • Diethoxyphosphate-tyrosine does not lose an alkyl group. • Proteins in addition to AChE and BChE are modified by organophosphates.
12. Diagnosis and dosimetry of exposure to sulfur mustard: Development of a standard operating procedure for mass spectrometric analysis of haemoglobin adducts - Exploratory research on albumin and keratin adducts
NARCIS (Netherlands)
Noort, D.; Fidder, A.; Hulst, A.G.; Jong, L.P.A. de; Benschop, H.P.
2000-01-01
Experiments were carried out to develop a standard operating procedure for analysis of sulfur mustard adducts to the N-terminal valine in haemoglobin and to explore adduct formation with albumin and keratin. In the first approach, gas chromatography-negative chemical ionization/mass spectrometry (GC
13. Diagnosis and dosimetry of exposure to sulfur mustard: Development of a standard operating procedure for hemoglobin adducts: Exploratory research on albumin and keratin adducts
NARCIS (Netherlands)
Noort, D.; Fidder, A.; Jong, L.P.A. de; Schans, G.P. van der; Benschop, H.P.
2000-01-01
A standard operating procedure (SOP) for determination of the sulfur mustard adduct to the N-terminal valine in hemoglobin was developed. By using this SOP, it was found that the Nterminal valine adduct in globin of hairless guinea pigs and marmosets which had been exposed to sulfur mustard (0.5 LD5
14. Product ion studies of diastereomeric benzo[ghi]fluoranthene-2'-deoxynucleoside adducts by electrospray ionization and quadrupole ion trap mass spectrometry
Energy Technology Data Exchange (ETDEWEB)
Li Linge [Department of Chemistry, Loyola University, Chicago, IL 60626 (United States); Chang, H.-F. [Department of Biomedical Sciences, University of Rhode Island, Kingston, RI 02881 (United States); Olsen, Kenneth W. [Department of Chemistry, Loyola University, Chicago, IL 60626 (United States); Cho, Bongsup P. [Department of Biomedical Sciences, University of Rhode Island, Kingston, RI 02881 (United States); Chiarelli, M. Paul [Department of Chemistry, Loyola University, Chicago, IL 60626 (United States)]. E-mail: mchiare@luc.edu
2006-01-31
The product ion formation characteristics of the protonated molecule ions generated from 10 different deoxynucleoside adducts of benzo[ghi]fluoranthene (B[ghi]F) have been studied using electrospray ionization (ESI) and quadrupole ion trap mass spectrometry to gain a better understanding of the fragmentation mechanisms that govern structure-specific fragmentation. The reaction of the syn- and anti-diastereomers of trans-3,4-dihydroxy-5,5a-tetrahydrobenzo[ghi]fluoranthene with DNA produce four deoxyguanosine, four deoxyadenosine, and two deoxycytidine adducts whose structures differ based on the cis/trans arrangement of the hydroxyl groups and nucleic acids bound to B[ghi]F. Those adducts that have structures where the nucleic acid and 3'-hydroxyl group of B[ghi]F are cis with respect to each other undergo extensive water loss whereas those isomers where the nucleic acid and 3'-hydroxyl group are trans do not. These results are consistent with a mechanism of water loss initiated by a hydrogen-bonding interaction between the charge-bearing proton on a heterocyclic nitrogen atom on the nucleic acid and the 3'-hydroxyl oxygen on the PAH. The dG and dC adducts are observed to undergo more extensive water loss than the dA adducts. Molecular modeling indicates that the larger relative abundances of the product ions formed by water loss for the dG and dC relative to dA are due to stronger hydrogen-bonding interactions prior to fragmentation and the greater stability of the carbocations formed at the C3' carbon after fragmentation.
15. DNA damage in humans exposed to environmental and dietary polycyclic aromatic hydrocarbons
Energy Technology Data Exchange (ETDEWEB)
Schoket, Bernadette [National Institute of Environmental Health, Jozsef Fodor National Centre of Public Health, Gyaliut 2-6, Budapest (Hungary)
1999-03-08
The paper describes recent research on human DNA damage related to environmental and dietary polycyclic aromatic hydrocarbon (Pah) exposures. The study populations either represent general populations of large geographical regions, or their exposure situation may have relevance to the general population. In Silesia, Poland, and Northern Bohemia, Czech Republic, where coal-based industry and domestic heating are the major sources of PAHs, significant differences have been observed in white blood cell DNA adducts and cytogenetic biomarkers between environmentally exposed and rural control populations, and significant seasonal variations of DNA damage have been detected. Bus drivers, traffic policemen and local residents have been involved in biomarker studies in Copenhagen, Athens, Genoa and Cairo, and differences have been measured in the level of DNA damage of urban and rural populations. Burning of smoky coal in unvented homes in Xuan Weiregion, China, causes high PAH exposure of residents, which has been reflected in DNA adduct levels in different tissues. Indoor wood burning in open fireplaces did not increase human DNA adduct levels. Oil-well fires left burning in Kuwait after the Persian Gulf war created an unprecedented environmental pollution. However, insignificant environmental PAH levels were measured several miles from these fires. Aromatic and PAH-DNA adduct level sin white blood cells of US Army soldiers were lower during their deployment in Kuwait, than in Fulda, Germany, where they were stationed before and after serving in Kuwait. The contribution of dietary PAH exposure to blood cell DNA adduct levels had been demonstrated in studies in which volunteers consumed heavily charbroiled beef. Environmental tobacco smoke did not cause detectable changes, as measured by{sup 32}P-postlabelling, in DNA adduct levels in non-smokers. In the reviewed studies, observed DNA adduct levels were generally in the range of 1 to 10 adducts, and not higher than 40
16. Zinc acetylacetonate hydrate adducted with nitrogen donor ligands: Synthesis, spectroscopic characterization, and thermal analysis
Science.gov (United States)
Brahma, Sanjaya; Shivashankar, S. A.
2015-12-01
We report synthesis, spectroscopic characterization, and thermal analysis of zinc acetylacetonate complex adducted by nitrogen donor ligands, such as pyridine, bipyridine, and phenanthroline. The pyridine adducted complex crystallizes to monoclinic crystal structure, whereas other two adducted complexes have orthorhombic structure. Addition of nitrogen donor ligands enhances the thermal property of these complexes as that with parent metal-organic complex. Zinc acetylacetonate adducted with pyridine shows much higher volatility (106 °C), decomposition temperature (202 °C) as that with zinc acetylacetonate (136 °C, 220 °C), and other adducted complexes. All the adducted complexes are thermally stable, highly volatile and are considered to be suitable precursors for metal organic chemical vapor deposition. The formation of these complexes is confirmed by powder X-ray diffraction, Fourier transform infrared spectroscopy, mass spectroscopy, and elemental analysis. The complexes are widely used as starting precursor materials for the synthesis of ZnO nanostructures by microwave irradiation assisted coating process.
17. Simulation of 125I induced DNA strand breaks in a CAP-DNA complex
International Nuclear Information System (INIS)
The E. coli catabolite gene activator protein (CAP)-DNA complex with 125I located at the position of the H5 atom of the cytosine near the centre was incorporated into the PARTRAC track structure code. DNA strand breaks due to irradiation were calculated by track structure and radical attack simulations: strand breaks due to neutralisation of the highly charged 125Te ion were derived from a semi-empirical distribution. According to the calculations, the neutralisation effect dominates the strand breakage frequency at 2 bases away from the 125I decay site on both strands. The first breakage distribution counted from a 32P labelled end on the strand with 125I agreed well with experimental data, but on the opposite strand, the calculated distribution is more concentrated around the decay site and its yield is about 20% larger than the measured data. (author)
18. Structure of adducts of isoindolo[2,1-a]benzimidazole derivatives with maleimides
Science.gov (United States)
Korolev, Oleksandr; Yegorova, Tatyana; Levkov, Igor; Malytskyy, Volodymyr; Shishkin, Oleg; Zubatyuk, Roman; Palamarchuk, Genadiy; Vedrenne, Marc; Baltas, Michel; Voitenko, Zoia
2015-03-01
The selectivity of formation and some mechanistic insights during the synthesis of substituted isoindolo[2,1-a]benzimidazoles are discussed. Furthermore, the reactions of the obtained products with maleimides were carried out. Two types rearrangement adducts together with intermediate Michael type adducts were isolated. The influence of the reaction conditions and reagents ratio is discussed. Specific spectral criteria for the identification of the Michael type adducts are indicated.
19. Metabolism of the Antibacterial Triclocarban by Human Epidermal Keratinocytes to Yield Protein Adducts
OpenAIRE
Schebb, Nils Helge; Buchholz, Bruce A.; Hammock, Bruce D.; Rice, Robert H.
2012-01-01
Previous studies of triclocarban suggest that its biotransformation could yield reactive metabolites that form protein adducts. Since the skin is the major route of triclocarban exposure, present work examined this possibility in cultured human keratinocytes. The results provide evidence for considerable biotransformation and protein adduct formation when cytochrome P450 activity is induced in the cells by TCDD, a model Ah receptor ligand. Since detecting low adduct levels in cells and tissue...
20. Structural aspects of adducts of N-phthaloylglycine and its derivatives
Science.gov (United States)
Barooah, Nilotpal; Sarma, Rupam J.; Batsanov, Andrei S.; Baruah, Jubaraj B.
2006-06-01
N-phthaloylglycine forms 2:1 adduct with 1,3-dihydroxybenzene and 1:2 adduct with 2-aminopyrimidine. Whereas N-phthaloylglycine form salts with 2,6-diaminopyridine and with 8-hydroxyquinoline. The 1:1 adduct of N, N'-bis(glycinyl)pyromellitic diimide with dimethylsulphoxide, 2-aminopyrimidine and 4,4'-dihydroxybiphenyl are prepared and characterised. The reaction of N, N'-bis(glycinyl)pyromellitic diimide with 2,6-diaminopyridine gives corresponding salt.
1. Analysis of dibenzo[def,p]chrysene-deoxyadenosine adducts in wild-type and cytochrome P450 1b1 knockout mice using stable-isotope dilution UHPLC-MS/MS.
Science.gov (United States)
Harper, Tod A; Morré, Jeff; Lauer, Fredine T; McQuistan, Tammie J; Hummel, Jessica M; Burchiel, Scott W; Williams, David E
2015-04-01
The polycyclic aromatic hydrocarbon (PAH), dibenzo[def,p]chrysene (DBC; also known as dibenzo[a,l]pyrene), is a potent carcinogen in animal models and a class 2A human carcinogen. Recent investigations into DBC-mediated toxicity identified DBC as a potent immunosuppressive agent similar to the well-studied immunotoxicant 7,12-dimethylbenz[a]anthracene (DMBA). DBC, like DMBA, is bioactivated by cytochrome P450 (CYP) 1B1 and forms the reactive metabolite DBC-11,12-diol-13,14-epoxide (DBCDE). DBCDE is largely responsible for the genotoxicity associated with DBC exposure. The immunosuppressive properties of several PAHs are also linked to genotoxic mechanisms. Therefore, this study was designed to identify DBCDE-DNA adduct formation in the spleen and thymus of wild-type and cytochrome P450 1b1 (Cyp1b1) knockout (KO) mice using a highly sensitive stable-isotope dilution UHPLC-MS/MS method. Stable-isotope dilution UHPLC-MS/MS identified the major DBC adducts (±)-anti-cis-DBCDE-dA and (±)-anti-trans-DBCDE-dA in the lung, liver, and spleen of both WT and Cyp1b1 KO mice. However, adduct formation in the thymus was below the level of quantitation for our method. Additionally, adduct formation in Cyp1b1 KO mice was significantly reduced compared to wild-type (WT) mice receiving DBC via oral gavage. In conclusion, the current study identifies for the first time DBCDE-dA adducts in the spleen of mice supporting the link between genotoxicity and immunosuppression, in addition to supporting previous studies identifying Cyp1b1 as the primary CYP involved in DBC bioactivation to DBCDE. The high levels of DBC-DNA adducts identified in the spleen, along with the known high levels of Cyp1b1 expression in this organ, supports further investigation into DBC-mediated immunotoxicity. PMID:25868132
2. Synthesis and Characterization of the Adducts of Bis(O-ethyldithiocarbonatocopper(II with Substituted Pyridines
Directory of Open Access Journals (Sweden)
Gurpreet Kour
2013-01-01
Full Text Available Monomeric five coordinated adducts of bis(O-ethyldithiocarbonatocopper(II of general formula [Cu(C2H5OCS22(L], [L = 2-, 3-, 4-methylpyridines and 2-, 3-, 4-ethylpyridines] have been synthesized and characterized by elemental analysis, i.r. and electronic spectroscopy, magnetic and conductivity measurements. Analytical results show that the adducts have 1 : 1 stoichiometry. The adducts were found to be paramagnetic and their magnetic moments at room temperature lie within the 1.81–1.94 B.M. range and this indicates the presence of one unpaired electron. All the adducts have distorted square pyramidal geometry.
3. Correlation between Quadriceps Endurance and Adduction Moment in Medial Knee Osteoarthritis.
Directory of Open Access Journals (Sweden)
Soon-Hyuck Lee
4. Electro-mechanical behaviors of composite superconducting strand with filament breakage
Science.gov (United States)
Wang, Xu; Gao, Yuanwen; Zhou, Youhe
2016-10-01
The bending behaviors of superconducting strand with typical multi-filament twist configuration are investigated based on a three-dimensional finite element method (FEM) model, named as the Multi-filament twist model, of the strand. In this 3D FEM model, the impacts of initial thermal residual stress, filament-breakage and its evaluation are taken into accounts. The mechanical responses of the strand under bending load are studied with the factors taken into consideration one by one. The distribution of the damage of the filaments and its evolution and the movement of the neutral axis caused by it are studied and displayed in detail. Besides, taking the advantages of the Multi-filament twist model, the normalized critical current of the strand under bending load is also calculated based on the invariant temperature and field strain functions. In addition, the non-negligible influences of the pitch length of the filaments on both the mechanical behaviors and the normalized critical current are discussed. The stress-strain characteristics of the strand under tensile load and the normalized critical current of it under axial and bending loads resulting from the Multi-filament twist model show good agreement with the experimental data.
5. The Breakage-Fusion-Bridge Cycle Producing MLL Amplification in a Case of Myelodysplastic Syndrome
Directory of Open Access Journals (Sweden)
Lan Ta
2013-01-01
Full Text Available Telomere loss may lead to chromosomal instability via the breakage-fusion-bridge (BFB cycle which can result in genetic amplification and the formation of ring and dicentric chromosomes. This cycle continues until stable chromosomes are formed. The case of a 72-year-old female with refractory anaemia with excess blasts type 2 illustrates these events. Conventional cytogenetics produced a complex karyotype which included unstable abnormalities of chromosomes 11, 12, and 15. Fluorescence in situ hybridization (FISH analyses including multicolor-FISH (M-FISH and multicolor-banding (M-BAND revealed multiple clonal populations with 5 copies of MLL on either a ring chromosome composed entirely of chromosome 11 material or a derivative chromosome composed of chromosomes 11, 12, and 15. The FISH results also clarified the likely evolution of the karyotypic complexity. The simplest cell line contained a dic(12;15 in addition to copy number aberrations that are typical of MDS or AML. As the disease progressed, a ring 11 was formed. Subsequently, the ring 11 appears to have unwound and inserted itself into the dic(12;15 chromosome followed by an inversion of the derivative chromosome, producing a der(11;15;12. Telomeric loss and BFB cycles appear to have played an important role in the chromosomal rearrangements and clonal evolution demonstrated in the karyotype.
6. Symmetry breakage in the frog Xenopus: role of Rab11 and the ventral-right blastomere.
Science.gov (United States)
Tingler, Melanie; Ott, Tim; Tözser, Janos; Kurz, Sabrina; Getwan, Maike; Tisler, Matthias; Schweickert, Axel; Blum, Martin
2014-06-01
Vertebrates display asymmetric arrangements of inner organs such as heart and stomach. The Nodal signaling cascade in the left lateral plate mesoderm in all cases directs asymmetric morphogenesis and placement during organogenesis. Mechanisms that lead up to left-asymmetric Nodal induction seem to differ between the vertebrates. Cilia produce a leftward extracellular fluid flow in zebrafish, medaka, mouse, rabbit, and Xenopus embryos during neurulation. In Xenopus, earlier asymmetric cues were described. Some, such as Rab11, apparently act in the zygote. Others were efficiently manipulated in ventral-right cells at the four-cell stage, a lineage presumably independent of the ciliated gastrocoel roof plate (GRP) during neurulation. Here, we show that one- and four-cell manipulations of Rab11 showed equal low efficiencies of left-right disturbances. We also reevaluated the lineage of the GRP. By tracing back future ciliated cells from the gastrula to the four-cell stage, we show that ventral cells contribute to ciliated sensory cells at the border of the GRP. Knockdown of the Nodal inhibitor Coco in the ventral right lineage resulted in embryos with ectopic right-sided Nodal and Pitx2c expression. Together, these experiments support a cilia-based mechanism of symmetry breakage in the frog Xenopus.
7. In vitro screening of 50 highly prescribed drugs for thiol adduct formation--comparison of potential for drug-induced toxicity and extent of adduct formation.
Science.gov (United States)
Gan, Jinping; Ruan, Qian; He, Bing; Zhu, Mingshe; Shyu, Wen C; Humphreys, W Griffith
2009-04-01
8. Evidence for the internucleosomal breakage of chromatin in rat thymocytes irradiated in vitro
International Nuclear Information System (INIS)
Low molecular-weight (free) DNA increases in lymphatic cells in association with radiation-induced interphase death. In this report, the size of the free DNA from rat thymocytes irradiated in vitro with 1-kR x rays was analyzed by agarose gel electrophoresis and compared with that of the DNA fragments extracted from micrococcal nuclease-digested thymocyte nuclei and with that of HaeIII-digested phi X-174 RF DNA. Results demonstrated clearly that the free DNA consisted of a series of discretely sized DNA fragments with lengths that were integral multiples of a nucleosomal DNA (180 base pairs), suggesting that internucleosomal chromatin breaks occurred in rat thymocytes after in vitro irradiation. Additional evidence was obtained from an electron microscopic observation on the breakdown of chromatin strands into particle form in the irradiated cells
9. Group 13 Superacid Adducts of [PCl2N]3.
Science.gov (United States)
Tun, Zin-Min; Heston, Amy J; Panzner, Matthew J; Scionti, Vincenzo; Medvetz, Doug A; Wright, Brian D; Johnson, Nicholas A; Li, Linlin; Wesdemiotis, Chrys; Rinaldi, Peter L; Youngs, Wiley J; Tessier, Claire A
2016-04-01
Irrespective of the order of the addition of reagents, the reactions of [PCl2N]3 with MX3 (MX3 = AlCl3, AlBr3, GaCl3) in the presence of water or gaseous HX give the air- and light-sensitive superacid adducts [PCl2N]3·HMX4. The reactions are quantitative when HX is used. These reactions illustrate a Lewis acid/Brønsted acid dichotomy in which Lewis acid chemistry can become Brønsted acid chemistry in the presence of adventitious water or HX. The crystal structures of all three [PCl2N]3·HMX4 adducts show that protonation weakens the two P-N bonds that flank the protonated nitrogen atom. Variable-temperature NMR studies indicate that exchange in solution occurs in [PCl2N]3·HMX4, even at lower temperatures than those for [PCl2N]3·MX3. The fragility of [PCl2N]3·HMX4 at or near room temperature and in the presence of light suggests that such adducts are not involved directly as intermediates in the high-temperature ring-opening polymerization (ROP) of [PCl2N]3 to give [PCl2N]n. Attempts to catalyze or initiate the ROP of [PCl2N]3 with the addition of [PCl2N]3·HMX4 at room temperature or at 70 °C were not successful. PMID:26974866
10. Effects of particle size and confining pressure on breakage factor of rockfill materials using medium triaxial test
OpenAIRE
Ashok Kumar Gupta
2016-01-01
Rockfill dams are mostly constructed using blasted rockfill materials obtained by blasting rocks or alluvial rockfill materials collected from the riverbeds. Behaviors of rockfill materials and their characterization significantly depend on breakage factor observed during triaxial loading. In this paper, two modeled rockfill materials are investigated by using medium triaxial cell. Drained triaxial tests are conducted on various sizes of modeled rockfill materials used in the two dams, and te...
11. DNA-Dependent Protein Kinase in Non-Homologous End-Joining: Guarding Strategic Positions
OpenAIRE
Weterings, Eric
2005-01-01
markdownabstract__Abstract__ Careful maintenance of genetic information throughout generations is of vital importance to all living creatures. A battery of both endogenous and exogenous factors continuously threatens genetic integrity by altering the DNA chemistry. As a consequence, DNA damage types are as diverse as their causes. DNA doublestrand breaks (DSBs) are among the most deleterious lesions, since they introduce chromosomal breakage or translocation and are able to trigger carcinogen...
12. Mutagenic effect of radionuclides incorporated into DNA of Drosophila melanogaster. Progress report, 1978-1979
International Nuclear Information System (INIS)
Current progress in studies on the mutagenic effect of 3H incorporated into the DNA of Drosophila melanogaster is reported. It was shown that selected 3H precursors incorporated into DNA are metabolized. The forms (metabolites) of tritium found in the DNA molecules and the mutation frequencies resulting therefrom were identified. An alcohol dehydrogenase system was developed for recovering mutations that is capable of distinguishing between base changes and chain breakage events that may lead to the formation of deletions
13. Experimental study of oxidative DNA damage
DEFF Research Database (Denmark)
Loft, S; Deng, Xiaohong; Tuo, J;
1998-01-01
of dative DNA damage and tumour formation. In principle the level of oxidative DNA damage in an organ or cell may be studied by measurement of modified bases in extracted DNA by immunohistochemical visualisation, and from assays of strand breakage before and after treatment with repair enzymes. However......Animal experiments allow the study of oxidative DNA damage in target organs and the elucidation of dose-response relationships of carcinogenic and other harmful chemicals and conditions as well as the study of interactions of several factors. So far the effects of more than 50 different chemical...... to induce oxidative DNA damage in experimental animals. The hepatocarcinogen 2-nitropropane induces up to 10-fold increases in 8-oxodG levels in rat liver DNA. The level of 8-oxodG is also increased in kidneys and bone marrow but not in the testis. By means of 2-nitropropane we have shown correspondence...
14. ANALYSIS OF THE REASONS OF BREAKAGES OF RETAYNER OF THE CAMP OF PQF AND SOLUTION OF PROBLEMS
Directory of Open Access Journals (Sweden)
A. V. Chubenko
2015-01-01
Full Text Available The analysis of the reasons of breakages of the equipment of a retayner of the rolling mill PQF of pipe-rolling shop is made. Breakage of a retayner leads to a stop of all shop of hot rolling of pipes. On the basis of the obtained data the solution allowing to increase reliability and durability of the equipment of a retayner is proposed. The solution assumes change of algorithm of work in the operating programmable logical Simatic S7–400 controler of the rolling mill PQF. Changes concern the control unit of movement of a retayner. Transition from the uniformly acceleration of traffic control of a lath of a retayner to not uniformly accelerated is provided. Thanks to this decision the main reason for breakages of the equipment of a retayner of PQF – mechanical blows in gear connections is minimized. The decision doesn’t assume change of a design of the equipment or introduction to work of additional units. Costs of introduction are minimum.
15. Lack of Involvement of CEP Adducts in TLR Activation and in Angiogenesis
Science.gov (United States)
Gounarides, John; Cobb, Jennifer S.; Zhou, Jing; Cook, Frank; Yang, Xuemei; Yin, Hong; Meredith, Erik; Rao, Chang; Huang, Qian; Xu, YongYao; Anderson, Karen; De Erkenez, Andrea; Liao, Sha-Mei; Crowley, Maura; Buchanan, Natasha; Poor, Stephen; Qiu, Yubin; Fassbender, Elizabeth; Shen, Siyuan; Woolfenden, Amber; Jensen, Amy; Cepeda, Rosemarie; Etemad-Gilbertson, Bijan; Giza, Shelby; Mogi, Muneto; Jaffee, Bruce; Azarian, Sassan
2014-01-01
16. Lack of involvement of CEP adducts in TLR activation and in angiogenesis.
Directory of Open Access Journals (Sweden)
John Gounarides
17. The genome-wide DNA sequence specificity of the anti-tumour drug bleomycin in human cells.
Science.gov (United States)
Murray, Vincent; Chen, Jon K; Tanaka, Mark M
2016-07-01
The cancer chemotherapeutic agent, bleomycin, cleaves DNA at specific sites. For the first time, the genome-wide DNA sequence specificity of bleomycin breakage was determined in human cells. Utilising Illumina next-generation DNA sequencing techniques, over 200 million bleomycin cleavage sites were examined to elucidate the bleomycin genome-wide DNA selectivity. The genome-wide bleomycin cleavage data were analysed by four different methods to determine the cellular DNA sequence specificity of bleomycin strand breakage. For the most highly cleaved DNA sequences, the preferred site of bleomycin breakage was at 5'-GT* dinucleotide sequences (where the asterisk indicates the bleomycin cleavage site), with lesser cleavage at 5'-GC* dinucleotides. This investigation also determined longer bleomycin cleavage sequences, with preferred cleavage at 5'-GT*A and 5'- TGT* trinucleotide sequences, and 5'-TGT*A tetranucleotides. For cellular DNA, the hexanucleotide DNA sequence 5'-RTGT*AY (where R is a purine and Y is a pyrimidine) was the most highly cleaved DNA sequence. It was striking that alternating purine-pyrimidine sequences were highly cleaved by bleomycin. The highest intensity cleavage sites in cellular and purified DNA were very similar although there were some minor differences. Statistical nucleotide frequency analysis indicated a G nucleotide was present at the -3 position (relative to the cleavage site) in cellular DNA but was absent in purified DNA.
18. /sup 32/P-Postlabeling test for covalent DNA binding of chemicals in vivo: Application to a variety of aromatic carcinogens and methylating agents
Energy Technology Data Exchange (ETDEWEB)
Reddy, M.V.; Gupta, R.C.; Randerath, E.; Randerath, K.
1984-02-01
19. 32P-Postlabeling test for covalent DNA binding of chemicals in vivo: Application to a variety of aromatic carcinogens and methylating agents
International Nuclear Information System (INIS)
20. Failure of intramedullary femoral nail with segmental breakage of distal locking bolts: a case report and re- view of the literature
Directory of Open Access Journals (Sweden)
Aggerwal Sameer
2011-06-01
Full Text Available 【Abstract】Breakage of locking bolts is an impor- tant cause of interlocking nail failure in femoral fractures. It usually occurs in the form of single breakage in one of the distal bolts of the nail or nail breakage around the distal locking hole. Here we report an unusual case of intramedul- lary femoral nail failure with segmental breakage of both the distal locking bolts. Such a scenario usually complicates further management. We successfully managed this case with exchange nailing without bone grafting. Here we briefly reviewed the literature regarding such an unusual presenta- tion and discussed in detail the possible etiology of such a presentation and the management options when facing such a complex situation. Key words: Femoral fractures; Bone screws; Frac- ture fixation, intramedullary; Fracture healing
KAUST Repository
Li, Huaping
2011-08-17
The reaction between a bulky N-heterocylic carbene (NHC) and C60 leads to the formation of a thermally stable zwitterionic Lewis acid-base adduct that is connected via a C-C single bond. Low-energy absorption bands with weak oscillator strengths similar to those of n-doped fullerenes were observed for the product, consistent with a net transfer of electron density to the C60 core. Corroborating information was obtained using UV photoelectron spectroscopy, which revealed that the adduct has an ionization potential ∼1.5 eV lower than that of C60. Density functional theory calculations showed that the C-C bond is polarized, with a total charge of +0.84e located on the NHC framework and -0.84e delocalized on the C 60 cage. The combination of reactivity, characterization, and theoretical studies demonstrates that fullerenes can behave as Lewis acids that react with C-based Lewis bases and that the overall process describes n-doping via C-C bond formation. © 2011 American Chemical Society.
2. An algorithmic approach for breakage-fusion-bridge detection in tumor genomes.
Science.gov (United States)
Zakov, Shay; Kinsella, Marcus; Bafna, Vineet
2013-04-01
Breakage-fusion-bridge (BFB) is a mechanism of genomic instability characterized by the joining and subsequent tearing apart of sister chromatids. When this process is repeated during multiple rounds of cell division, it leads to patterns of copy number increases of chromosomal segments as well as fold-back inversions where duplicated segments are arranged head-to-head. These structural variations can then drive tumorigenesis. BFB can be observed in progress using cytogenetic techniques, but generally BFB must be inferred from data such as microarrays or sequencing collected after BFB has ceased. Making correct inferences from this data is not straightforward, particularly given the complexity of some cancer genomes and BFB's ability to generate a wide range of rearrangement patterns. Here we present algorithms to aid the interpretation of evidence for BFB. We first pose the BFB count-vector problem: given a chromosome segmentation and segment copy numbers, decide whether BFB can yield a chromosome with the given segment counts. We present a linear time algorithm for the problem, in contrast to a previous exponential time algorithm. We then combine this algorithm with fold-back inversions to develop tests for BFB. We show that, contingent on assumptions about cancer genome evolution, count vectors and fold-back inversions are sufficient evidence for detecting BFB. We apply the presented techniques to paired-end sequencing data from pancreatic tumors and confirm a previous finding of BFB as well as identify a chromosomal region likely rearranged by BFB cycles, demonstrating the practicality of our approach.
3. The dam breakage of Baia Mare??a pilot study of magnetic screening
Science.gov (United States)
Wehland, F.; Panaiotu, C.; Appel, E.; Hoffmann, V.; Jordanova, D.; Jordanova, N.; Denut, I.
Magnetic screening in the area of Baia Mare (Romania) was carried out in June 2000 in order to detect the degree of environmental pollution and to test the applicability of this method in this area. With a long tradition of mining activities, a gradual pollution of soil, air and rivers took place continuously in addition to smaller accidents in this area until the dam breakage on the 30.1.2000. During this accident, about 100,000 m 3 of mud containing cyanide and heavy metals leaked out and moved over fields and through a village into the river system of Lapûs, Someş, Tisza and Danube. Initial magnetic monitoring carried out during the translocation of the polluted waters along the Bulgarian part of the Danube revealed the effectiveness of the method for a proper and fast identification of pollution both in time and space even at remote distances from the source. For the later pilot project magnetic ( χ) screening was performed using a portable Bartington MS2 kappameter with a D-loop sensor. In addition fine-grained material (sensor. The results of the collected samples show a clear decrease in χ with increasing distance from the dams and mining areas in a regional and local scale, while the results gained by the MS2-D strongly depend on the nature of the ground. The dynamic geological setting around Baia Mare (fluvial sediments and valley fills), produces a heterogeneous background signal. A continuous monitoring system controlling the basic conditions could overcome these limitations.
4. Yield of photo-adduct formation of LOV domains from Chlamydomonas reinhardtii by picosecond laser excitation
International Nuclear Information System (INIS)
The photo-excitation of flavin mononucleotide (FMN) in the wild-type light, oxygen and voltage sensitive (LOV) domains of the blue-light photoreceptors phototropin causes the formation of an intermediate flavin-C(4a)-cysteinyl adduct. The adduct formation due to picosecond laser pulse exaction (wavelength 400nm) is studied on wild-type LOV1 and LOV2 domains of the phototropin phot from Chlamydomonas reinhardtii. The efficiency of adduct formation is probed by detection of the fluorescence signals caused by time-separated picosecond excitation pulses since FMN is fluorescent and the formed adduct is non-fluorescent. Quantum yields of adduct formation of φAd∼0.06 are determined for excitation with intense single-pulses of energy densities, wL, comparable to or larger than the saturation energy density, wsat,S0, of ground-state population depletion. Under repetitive picosecond pulse excitation conditions the efficiency of adduct formation rises with decreasing picosecond pulse energy density and approaches for wLsat,S0 the continuous blue-light exposure quantum yields of adduct formation in the range from φAd=0.5-0.9. Picosecond laser pulse induced energy deposition in the LOV domains causing protein conformational changes is discussed as main origin of the intensity dependent reduction of the efficiency of adduct-formation
5. Immunochemical detection of sulfur mustard adducts with keratins in the stratum corneum of human skin
NARCIS (Netherlands)
Schans, G.P. van der; Noort, D.; Mars-Groenendijk, R.H.; Fidder, A.; Chau, L.F.; Jong, L.P.A. de; Benschop, H.P.
2002-01-01
As part of a program to develop methods for diagnosis of exposure to chemical warfare agents, we developed immunochemical methods for detection of adducts of sulfur mustard to keratin in human skin. Three partial sequences of keratins containing glutamine or asparagine adducted with a 2-hydroxyethyl
6. Cytoplasmic sequestration of an O6-methylguanine-DNA methyltransferase enhancer binding protein in DNA repair-deficient human cells
OpenAIRE
Frank Y. Chen; Harris, Linda C.; Joanna S Remack; Brent, Thomas P.
1997-01-01
O6-Methylguanine-DNA methyltransferase (MGMT), an enzyme that repairs adducts at O6 of guanine in DNA, is a major determinant of susceptibility to simple methylating carcinogens or of tumor response to anticancer chloroethylating drugs. To investigate the mechanisms underlying cellular expression of this DNA repair enzyme, we focused on the role of a 59-bp enhancer of the human MGMT gene in the regulation of its expression. By using chloramphenicol acetyltransferase reporter assays, we found ...
7. Aprataxin resolves adenylated RNA-DNA junctions to maintain genome integrity
OpenAIRE
Tumbale, Percy; Williams, Jessica S.; Schellenberg, Matthew J.; Kunkel, Thomas A.; Williams, R Scott
2013-01-01
Faithful maintenance and propagation of eukaryotic genomes is ensured by three-step DNA ligation reactions employed by ATP-dependent DNA ligases 1,2 . Paradoxically, when DNA ligases encounter nicked DNA structures with abnormal DNA termini, DNA ligase catalytic activity can generate and/or exacerbate DNA damage through abortive ligation that produces chemically adducted, toxic 5′-adenylated (5′-AMP) DNA lesions 3–6 (Fig. 1a). Aprataxin (Aptx) reverses DNA-adenylation but the context for dead...
8. The NBS1-Treacle complex controls ribosomal RNA transcription in response to DNA damage
DEFF Research Database (Denmark)
Larsen, Dorthe H; Hari, Flurina; Clapperton, Julie A;
2014-01-01
recruitment of the Nijmegen breakage syndrome protein 1 (NBS1), a central regulator of DNA damage responses, into the nucleoli. We further identify TCOF1 (also known as Treacle), a nucleolar factor implicated in ribosome biogenesis and mutated in Treacher Collins syndrome, as an interaction partner of NBS1...
9. DNA damage in internal organs after cutaneous exposure to sulphur mustard
Energy Technology Data Exchange (ETDEWEB)
Batal, Mohamed [Laboratoire « Lésions des Acides Nucléiques », Université Joseph Fourier – Grenoble 1/CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche, BP87, F-38702 La Tronche Cedex (France); Boudry, Isabelle; Mouret, Stéphane; Cléry-Barraud, Cécile; Wartelle, Julien [Département de Toxicologie et Risques Chimiques, Unité de Brûlure Chimique, Institut de Recherche Biomédicale des Armées, Antenne de La Tronche, BP87, F-38702 La Tronche Cedex (France); Bérard, Izabel [Laboratoire « Lésions des Acides Nucléiques », Université Joseph Fourier – Grenoble 1/CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France); Douki, Thierry, E-mail: thierry.douki@cea.fr [Laboratoire « Lésions des Acides Nucléiques », Université Joseph Fourier – Grenoble 1/CEA/Institut Nanoscience et Cryogénie/SCIB, UMR-E3, Grenoble (France)
2014-07-01 | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 1, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.6813165545463562, "perplexity": 17154.60114510588}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2017-22/segments/1495463607731.0/warc/CC-MAIN-20170524020456-20170524040456-00234.warc.gz"} |
http://nrich.maths.org/6628/solution | ### Overarch 2
Bricks are 20cm long and 10cm high. How high could an arch be built without mortar on a flat horizontal surface, to overhang by 1 metre? How big an overhang is it possible to make like this?
### Stonehenge
Explain why, when moving heavy objects on rollers, the object moves twice as fast as the rollers. Try a similar experiment yourself.
### Maximum Flow
Given the graph of a supply network and the maximum capacity for flow in each section find the maximum flow across the network.
# Turbo Turbines
##### Stage: 5 Challenge Level:
$M_{total} = 3 \int^L_0{k V \left( \frac{3}{4} + \frac{x^2}{4L^2}\right) } dx$
$= 3 k V \left[\frac{3 x}{4} + \frac{x^3}{12 L^2} \right]^L_0$
$= 3 k V \left[\frac{3}{4} L + \frac{1}{12} L \right] = \frac{5}{2} k V L$
Equating this to the resistive torque, $\frac{5}{2} k V L = 5T$
$\therefore V_{crit} = 2T/(kL)$.
Since the torque is fixed, you might decrease the minimum wind speed by improving the geometry of the blade and thus increasing $k$, or by increasing the blade length. Increasing the number of blades on the turbine would also decrease $V_{crit}$.
The rotational analogy is
Power = Torque $\times$ Angular Velocity
The power produced by the generator is thus $A \omega_g^2$. The 1:50 ratio of the gearbox tells us that $\omega_g$ can be approximated by $50 B k V$, when $V > V_{crit}$. | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 1, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8814772367477417, "perplexity": 1536.5007348131512}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.3, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2015-48/segments/1448398445142.9/warc/CC-MAIN-20151124205405-00127-ip-10-71-132-137.ec2.internal.warc.gz"} |
https://iotmakerblog.wordpress.com/2016/06/05/12-support-vector-machines-svms/ | # [ 12: Support Vector Machines (SVMs) ]
Support Vector Machine (SVM) – Optimization objective
• So far, we’ve seen a range of different algorithms
• With supervised learning algorithms – performance is pretty similar
• What matters more often is;
• The amount of training data
• Skill of applying algorithms
• One final supervised learning algorithm that is widely used – support vector machine (SVM)
• Compared to both logistic regression and neural networks, a SVM sometimes gives a cleaner way of learning non-linear functions
• Later in the course we’ll do a survey of different supervised learning algorithms
An alternative view of logistic regression
• Start with logistic regression, see how we can modify it to get the SVM
• As before, the logistic regression hypothesis is as follows
• And the sigmoid activation function looks like this
• In order to explain the math, we use z as defined above
• What do we want logistic regression to do?
• We have an example where y = 1
• Then we hope hθ(x) is close to 1
• With hθ(x) close to 1, (θT x) must be much larger than 0
• Similarly, when y = 0
• Then we hope hθ(x) is close to 0
• With hθ(x) close to 0, (θT x) must be much less than 0
• This is our classic view of logistic regression
• Let’s consider another way of thinking about the problem
• Alternative view of logistic regression
• If you look at cost function, each example contributes a term like the one below to the overall cost function
• For the overall cost function, we sum over all the training examples using the above function, and have a 1/m term
• If you then plug in the hypothesis definition (hθ(x)), you get an expanded cost function equation;
• So each training example contributes that term to the cost function for logistic regression
• If y = 1 then only the first term in the objective matters
• If we plot the functions vs. z we get the following graph
• This plot shows the cost contribution of an example when y = 1 given z
• So if z is big, the cost is low – this is good!
• But if z is 0 or negative the cost contribution is high
• This is why, when logistic regression sees a positive example, it tries to set θT x to be a very large term
• If y = 0 then only the second term matters
• We can again plot it and get a similar graph
• Same deal, if z is small then the cost is low
• But if s is large then the cost is massive
SVM cost functions from logistic regression cost functions
• To build a SVM we must redefine our cost functions
• When y = 1
• Take the y = 1 function and create a new cost function
• Instead of a curved line create two straight lines (magenta) which acts as an approximation to the logistic regression y = 1 function
• Take point (1) on the z axis
• Flat from 1 onwards
• Grows when we reach 1 or a lower number
• This means we have two straight lines
• Flat when cost is 0
• Straight growing line after 1
• So this is the new y=1 cost function
• Gives the SVM a computational advantage and an easier optimization problem
• We call this function cost1(z)
• Similarly
• When y = 0
• Do the equivalent with the y=0 function plot
• We call this function cost0(z)
• So here we define the two cost function terms for our SVM graphically
• How do we implement this?
The complete SVM cost function
• As a comparison/reminder we have logistic regression below
• If this looks unfamiliar its because we previously had the – sign outside the expression
• For the SVM we take our two logistic regression y=1 and y=0 terms described previously and replace with
• cost1T x)
• cost0T x)
• So we get
SVM notation is slightly different
• In convention with SVM notation we rename a few things here
• 1) Get rid of the 1/m terms
• This is just a slightly different convention
• By removing 1/m we should get the same optimal values for
• 1/m is a constant, so should get same optimization
• e.g. say you have a minimization problem which minimizes to u = 5
• If your cost function * by a constant, you still generates the minimal value
• That minimal value is different, but that’s irrelevant
• 2) For logistic regression we had two terms;
• Training data set term (i.e. that we sum over m) = A
• Regularization term (i.e. that we sum over n) = B
• So we could describe it as A + λB
• Need some way to deal with the trade-off between regularization and data set terms
• Set different values for λ to parametrize this trade-off
• Instead of parameterization this as A + λB
• For SVMs the convention is to use a different parameter called C
• So do CA + B
• If C were equal to 1/λ then the two functions (CA + B and A + λB) would give the same value
• So, our overall equation is
• Unlike logistic, hθ(x) doesn’t give us a probability, but instead we get a direct prediction of 1 or 0
• So if θT x is equal to or greater than 0 –> hθ(x) = 1
• Else –> hθ(x) = 0
Large margin intuition
• Sometimes people refer to SVM as large margin classifiers
• We’ll consider what that means and what an SVM hypothesis looks like
• The SVM cost function is as above, and we’ve drawn out the cost terms below
• Left is cost1 and right is cost0
• What does it take to make terms small
• If y =1
• cost1(z) = 0 only when z >= 1
• If y = 0
• cost0(z) = 0 only when z <= -1
• Interesting property of SVM
• If you have a positive example, you only really need z to be greater or equal to 0
• If this is the case then you predict 1
• SVM wants a bit more than that – doesn’t want to *just* get it right, but have the value be quite a bit bigger than zero
• Throws in an extra safety margin factor
• Logistic regression does something similar
• What are the consequences of this?
• Consider a case where we set C to be huge
• C = 100,000
• So considering we’re minimizing CA + B
• If C is huge we’re going to pick an A value so that A is equal to zero
• What is the optimization problem here – how do we make A = 0?
• Making A = 0
• If y = 1
• Then to make our “A” term 0 need to find a value of θ so (θT x) is greater than or equal to 1
• Similarly, if y = 0
• Then we want to make “A” = 0 then we need to find a value of θ so (θT x) is equal to or less than -1
• So – if we think of our optimization problem a way to ensure that this first “A” term is equal to 0, we re-factor our optimization problem into just minimizing the “B” (regularization) term, because
• When A = 0 –> A*C = 0
• So we’re minimizing B, under the constraints shown below
• Turns out when you solve this problem you get interesting decision boundaries
• The green and magenta lines are functional decision boundaries which could be chosen by logistic regression
• But they probably don’t generalize too well
• The black line, by contrast is the the chosen by the SVM because of this safety net imposed by the optimization graph
• More robust separator
• Mathematically, that black line has a larger minimum distance (margin) from any of the training examples
• By separating with the largest margin you incorporate robustness into your decision making process
• We looked at this at when C is very large
• SVM is more sophisticated than the large margin might look
• If you were just using large margin then SVM would be very sensitive to outliers
• You would risk making a ridiculous hugely impact your classification boundary
• A single example might not represent a good reason to change an algorithm
• If C is very large then we do use this quite naive maximize the margin approach
• So we’d change the black to the magenta
• But if C is reasonably small, or a not too large, then you stick with the black decision boundary
• What about non-linearly separable data?
• Then SVM still does the right thing if you use a normal size C
• So the idea of SVM being a large margin classifier is only really relevant when you have no outliers and you can easily linearly separable data
• Means we ignore a few outliers
Large margin classification mathematics (optional)
Vector inner products
• Have two (2D) vectors u and v – what is the inner product (uT v)?
• Plot u on graph
• i.e u1 vs. u2
• One property which is good to have is the norm of a vector
• Written as ||u||
• This is the euclidean length of vector u
• So ||u|| = SQRT(u12 + u22) = real number
• i.e. length of the arrow above
• Can show via Pythagoras
• For the inner product, take v and orthogonally project down onto u
• First we can plot v on the same axis in the same way (vvs v1)
• Measure the length/magnitude of the projection
• So here, the green line is the projection
• p = length along u to the intersection
• p is the magnitude of the projection of vector v onto vector u
• Possible to show that
• uT v = p * ||u||
• So this is one way to compute the inner product
• uT v = u1v1u2v2
• So therefore
• p * ||u|| = u1v1u2v2
• This is an important rule in linear algebra
• We can reverse this too
• So we could do
• vT u = v1u1+ v2u2
• Which would obviously give you the same number
• p can be negative if the angle between them is 90 degrees or more
• So here p is negative
• Use the vector inner product theory to try and understand SVMs a little better
SVM decision boundary
• For the following explanation – two simplification
• Set θ0= 0 (i.e. ignore intercept terms)
• Set n = 2 – (x1, x2)
• i.e. each example has only 2 features
• Given we only have two parameters we can simplify our function to
• And, can be re-written as
• Should give same thing
• We may notice that
• The term in red is the norm of θ
• If we take θ as a 2×1 vector
• If we assume θ0 = 0 its still true
• So, finally, this means our optimization function can be re-defined as
• So the SVM is minimizing the squared norm
• Given this, what are the (θT x) parameters doing?
• Given θ and given example x what is this equal to
• We can look at this in a comparable manner to how we just looked at u and v
• Say we have a single positive training example (red cross below)
• Although we haven’t been thinking about examples as vectors it can be described as such
• Now, say we have our parameter vector θ and we plot that on the same axis
• The next question is what is the inner product of these two vectors
• p, is in fact pi, because it’s the length of p for example i
• Given our previous discussion we know
T xi ) = pi * ||θ||
= θ1xi1 + θ2xi2
• So these are both equally valid ways of computing θT xi
• What does this mean?
• The constraints we defined earlier
• T x) >= 1 if y = 1
• T x) <= -1 if y = 0
• Can be replaced/substituted with the constraints
• pi * ||θ|| >= 1 if y = 1
• pi * ||θ|| <= -1 if y = 0
• Writing that into our optimization objective
• So, given we’ve redefined these functions let us now consider the training example below
• Given this data, what boundary will the SVM choose? Note that we’re still assuming θ0 = 0, which means the boundary has to pass through the origin (0,0)
• Green line – small margins
• SVM would not chose this line
• Decision boundary comes very close to examples
• Lets discuss why the SVM would not chose this decision boundary
• Looking at this line
• We can show that θ is at 90 degrees to the decision boundary
• θ is always at 90 degrees to the decision boundary (can show with linear algebra, although we’re not going to!)
• So now lets look at what this implies for the optimization objective
• Look at first example (x1)
• Project a line from xon to to the θ vector (so it hits at 90 degrees)
• The distance between the intersection and the origin is (p1)
• Similarly, look at second example (x2)
• Project a line from x2 into to the θ vector
• This is the magenta line, which will be negative (p2)
• If we overview these two lines below we see a graphical representation of what’s going on;
• We find that both these p values are going to be pretty small
• If we look back at our optimization objective
• We know we need p1 * ||θ|| to be bigger than or equal to 1 for positive examples
• If p is small
• Means that ||θ|| must be pretty large
• Similarly, for negative examples we need p2 * ||θ|| to be smaller than or equal to -1
• We saw in this example p2 is a small negative number
• So ||θ|| must be a large number
• Why is this a problem?
• The optimization objective is trying to find a set of parameters where the norm of theta is small
• So this doesn’t seem like a good direction for the parameter vector (because as p values get smaller ||θ|| must get larger to compensate)
• So we should make p values larger which allows ||θ|| to become smaller
• So lets chose a different boundary
• Now if you look at the projection of the examples to θ we find that pbecomes large and ||θ|| can become small
• So with some values drawn in
• This means that by choosing this second decision boundary we can make ||θ|| smaller
• Which is why the SVM choses this hypothesis as better
• This is how we generate the large margin effect
• The magnitude of this margin is a function of the p values
• So by maximizing these p values we minimize ||θ||
• Finally, we did this derivation assuming θ0 = 0,
• If this is the case we’re entertaining only decision boundaries which pass through (0,0)
• If you allow θ0 to be other values then this simply means you can have decision boundaries which cross through the x and y values at points other than (0,0)
• Can show with basically same logic that this works, and even when θ0 is non-zero when you have optimization objective described above (when C is very large) that the SVM is looking for a large margin separator between the classes
Kernels – 1: Adapting SVM to non-linear classifiers
• What are kernels and how do we use them
• We have a training set
• We want to find a non-linear boundary
• Come up with a complex set of polynomial features to fit the data
• Have hθ(x) which
• Returns 1 if the combined weighted sum of vectors (weighted by the parameter vector) is less than or equal to 0
• Else return 0
• Another way of writing this (new notation) is
• That a hypothesis computes a decision boundary by taking the sum of the parameter vector multiplied by a new feature vector f, which simply contains the various high order x terms
• e.g.
• hθ(x) = θ0+ θ1f1+ θ2f+ θ3f3
• Where
• f1= x1
• f= x1x2
• f= …
• i.e. not specific values, but each of the terms from your complex polynomial function
• Is there a better choice of feature f than the high order polynomials?
• As we saw with computer imaging, high order polynomials become computationally expensive
• New features
• Define three features in this example (ignore x0)
• Have a graph of xvs. x(don’t plot the values, just define the space)
• Pick three points in that space
• These points l1, l2, and l3, were chosen manually and are called landmarks
• Given x, define f1 as the similarity between (x, l1)
• = exp(- (|| x – l||2 ) / 2σ2)
• || x – l|| is the euclidean distance between the point x and the landmark lsquared
• Disussed more later
• If we remember our statistics, we know that
• σ is the standard deviation
• σis commonly called the variance
• Remember, that as discussed
• So, f2 is defined as
• f2 = similarity(x, l1) = exp(- (|| x – l||) / 2σ2)
• And similarly
• f3 = similarity(x, l2) = exp(- (|| x – l||) / 2σ2)
• This similarity function is called a kernel
• This function is a Gaussian Kernel
• So, instead of writing similarity between x and l we might write
• f1 = k(x, l1)
Diving deeper into the kernel
• So lets see what these kernels do and why the functions defined make sense
• Say x is close to a landmark
• Then the squared distance will be ~0
• So
• Which is basically e-0
• Which is close to 1
• Say x is far from a landmark
• Then the squared distance is big
• Gives e-large number
• Which is close to zero
• Each landmark defines a new features
• If we plot f1 vs the kernel function we get a plot like this
• Notice that when x = [3,5] then f1 = 1
• As x moves away from [3,5] then the feature takes on values close to zero
• So this measures how close x is to this landmark
What does σ do?
• σis a parameter of the Gaussian kernel
• Defines the steepness of the rise around the landmark
• Above example σ2 = 1
• Below σ2 = 0.5
• We see here that as you move away from 3,5 the feature f1 falls to zero much more rapidly
• The inverse can be seen if σ2 = 3
• Given this definition, what kinds of hypotheses can we learn?
• With training examples x we predict “1” when
• θ0+ θ1f1+ θ2f+ θ3f3 >= 0
• For our example, lets say we’ve already run an algorithm and got the
• θ= -0.5
• θ= 1
• θ= 1
• θ= 0
• Given our placement of three examples, what happens if we evaluate an example at the magenta dot below?
• Looking at our formula, we know f1 will be close to 1, but f2 and f3 will be close to 0
• So if we look at the formula we have
• θ0+ θ1f1+ θ2f+ θ3f3 >= 0
• -0.5 + 1 + 0 + 0 = 0.5
• 0.5 is greater than 1
• If we had another point far away from all three
• This equates to -0.5
• So we predict 0
• Considering our parameter, for points near l1 and l2 you predict 1, but for points near lyou predict 0
• Which means we create a non-linear decision boundary that goes a lil’ something like this;
• Inside we predict y = 1
• Outside we predict y = 0
• So this show how we can create a non-linear boundary with landmarks and the kernel function in the support vector machine
• But
• How do we get/chose the landmarks
• What other kernels can we use (other than the Gaussian kernel)
Kernels II
• Filling in missing detail and practical implications regarding kernels
• Spoke about picking landmarks manually, defining the kernel, and building a hypothesis function
• Where do we get the landmarks from?
• For complex problems we probably want lots of them
Choosing the landmarks
• Take the training data
• For each example place a landmark at exactly the same location
• So end up with m landmarks
• One landmark per location per training example
• Means our features measure how close to a training set example something is
• Given a new example, compute all the f values
• Gives you a feature vector f (f0 to fm)
• f0 = 1 always
• A more detailed look at generating the f vector
• If we had a training example – features we compute would be using (xi, yi)
• So we just cycle through each landmark, calculating how close to that landmark actually xi is
• f1i, = k(xi, l1)
• f2i, = k(xi, l2)
• fmi, = k(xi, lm)
• Somewhere in the list we compare x to itself… (i.e. when we’re at fii)
• So because we’re using the Gaussian Kernel this evalues to 1
• Take these m features (f1, f2 … fm) group them into an [m +1 x 1] dimensional vector called f
• fi is the f feature vector for the ith example
• And add a 0th term = 1
• Given these kernels, how do we use a support vector machine
SVM hypothesis prediction with kernels
• Predict y = 1 if (θT f) >= 0
• Because θ = [m+1 x 1]
• And f = [m +1 x 1]
• So, this is how you make a prediction assuming you already have θ
• How do you get θ?
SVM training with kernels
• Use the SVM learning algorithm
• Now, we minimize using f as the feature vector instead of x
• By solving this minimization problem you get the parameters for your SVM
• In this setup, m = n
• Because number of features is the number of training data examples we have
• One final mathematic detail (not crucial to understand)
• If we ignore θ0 then the following is true
• What many implementations do is
• Where the matrix M depends on the kernel you use
• Gives a slightly different minimization – means we determine a rescaled version of θ
• Allows more efficient computation, and scale to much bigger training sets
• If you have a training set with 10 000 values, means you get 10 000 features
• Solving for all these parameters can become expensive
• So by adding this in we avoid a for loop and use a matrix multiplication algorithm instead
• You can apply kernels to other algorithms
• But they tend to be very computationally expensive
• But the SVM is far more efficient – so more practical
• Lots of good off the shelf software to minimize this function
• SVM parameters (C)
• Bias and variance trade off
• Must chose C
• C plays a role similar to 1/LAMBDA (where LAMBDA is the regularization parameter)
• Large C gives a hypothesis of low bias high variance –> overfitting
• Small C gives a hypothesis of high bias low variance –> underfitting
• SVM parameters (σ2)
• Parameter for calculating f values
• Large σ2 – f features vary more smoothly – higher bias, lower variance
• Small σ2 – f features vary abruptly – low bias, high variance
SVM – implementation and use
• So far spoken about SVM in a very abstract manner
• What do you need to do this
• Use SVM software packages (e.g. liblinear, libsvm) to solve parameters θ
• Need to specify
• Choice of parameter C
• Choice of kernel
Choosing a kernel
• We’ve looked at the Gaussian kernel
• Need to define σ (σ2)
• Discussed σ2
• When would you chose a Gaussian?
• If n is small and/or m is large
• e.g. 2D training set that’s large
• If you’re using a Gaussian kernel then you may need to implement the kernel function
• e.g. a function
fi = kernel(x1,x2)
• Returns a real number
• Some SVM packages will expect you to define kernel
• Although, some SVM implementations include the Gaussian and a few others
• Gaussian is probably most popular kernel
• NB – make sure you perform feature scaling before using a Gaussian kernel
• If you don’t features with a large value will dominate the f value
• Could use no kernel – linear kernel
• Predict y = 1 if (θT x) >= 0
• So no f vector
• Get a standard linear classifier
• Why do this?
• If n is large and m is small then
• Lots of features, few examples
• Not enough data – risk overfitting in a high dimensional feature-space
• Other choice of kernel
• Linear and Gaussian are most common
• Not all similarity functions you develop are valid kernels
• Must satisfy Merecer’s Theorem
• SVM use numerical optimization tricks
• Mean certain optimizations can be made, but they must follow the theorem
• Polynomial Kernel
• We measure the similarity of x and l by doing one of
• (xT l)2
• (xT l)3
• (xT l+1)3
• General form is
• (xT l+Con)D
• If they’re similar then the inner product tends to be large
• Not used that often
• Two parameters
• Degree of polynomial (D)
• Number you add to l (Con)
• Usually performs worse than the Gaussian kernel
• Used when x and l are both non-negative
• String kernel
• Used if input is text strings
• Use for text classification
• Chi-squared kernel
• Histogram intersection kernel
Multi-class classification for SVM
• Many packages have built in multi-class classification packages
• Otherwise use one-vs all method
• Not a big issue
Logistic regression vs. SVM
• When should you use SVM and when is logistic regression more applicable
• If n (features) is large vs. m (training set)
• e.g. text classification problem
• Feature vector dimension is 10 000
• Training set is 10 – 1000
• Then use logistic regression or SVM with a linear kernel
• If n is small and m is intermediate
• n = 1 – 1000
• m = 10 – 10 000
• Gaussian kernel is good
• If n is small and m is large
• n = 1 – 1000
• m = 50 000+
• SVM will be slow to run with Gaussian kernel
• In that case
• Manually create or add more features
• Use logistic regression of SVM with a linear kernel
• Logistic regression and SVM with a linear kernel are pretty similar
• Do similar things
• Get similar performance
• A lot of SVM’s power is using diferent kernels to learn complex non-linear functions
• For all these regimes a well designed NN should work
• But, for some of these problems a NN might be slower – SVM well implemented would be faster
• SVM has a convex optimization problem – so you get a global minimum
• It’s not always clear how to chose an algorithm
• Often more important to get enough data
• Designing new features
• Debugging the algorithm
• SVM is widely perceived a very powerful learning algorithm | {"extraction_info": {"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8052597641944885, "perplexity": 1579.3571311483117}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2018-05/segments/1516084886476.31/warc/CC-MAIN-20180116164812-20180116184812-00329.warc.gz"} |
https://computationalcombinatorics.wordpress.com/2014/04/30/rainbow-arithmetic-progressions-i-search-algorithm/ | ### Rainbow Arithmetic Progressions I : Search Algorithm
At Iowa State, we tried an experiment this year to have a Discrete Mathematics Working Seminar where the group that normally meets for a research talk stays for an extra hour a week to work on a research problem. The goal was to break into smaller groups, but we ended up staying as one giant mass of mathematicians, including 5 faculty, a lecturer, and 6 graduate students. We recently posted the result to the arXiv:
S. Butler, C. Erickson, L. Hogben, K. Hogenson, L. Kramer, R. L. Kramer, J. C.-H. Lin, R. R. Martin, D. Stolee, N. Warnberg, and M. Young, Rainbow arithmetic progressions, arXiv:1404.7232 [math.CO]
Today, we will discuss the backtrack-search that was used to gather initial data on this problem. Since the paper features proofs as its main feature, not all of the algorithmic details were discussed (but enough were that anyone could figure out the rest). Here, I’ll flesh out as much detail as I can. In a later post, I will comment on the experimental collaboration.
### Anti-van der Waerden Numbers
Let $G$ be an abelian group, and let $S$ be a subset of $G$. We say that a set $A \subset S$ of size $|A| = k$ is a $k$-term arithmetic progression ($k$-AP) if there exists an element $d \in G$ such that for a reordering $A = \{ a_1, \dots, a_k\}$ we have $a_{i+1} = a_i + d$ for all $i \in \{1,\dots,k-1\}$. We shall take $S \subseteq G$ to be one of $[n] \subset {\mathbb Z}$ or $\mathbb{Z}_n \subseteq \mathbb{Z}_n$.
The van der Waerden number $w(k,r)$ is the minimum $n$ such that every $r$-coloring of $[n]$ contains a monochromatic $k$-AP. This is a standard Ramsey-theory definition. What we do is consider the anti-Ramsey version of van der Waerden numbers by trying to avoid rainbow arithmetic progressions.
An exact $r$-coloring of $S$ is a surjective function $c : S \to [r]$. A set is rainbow if its elements receive distinct colors. The anti-van der Waerden number $\mathrm{aw}(S,k)$ is the minimum positive integer $r$ such that every exact $r$-coloring of $S$ contains a rainbow $k$-AP. It is not difficult to see that this is well-defined and $\mathrm{aw}(S,k) \leq |S|$.
In the paper, we prove bounds on $\mathrm{aw}([n],k)$ and $\mathrm{aw}({\mathbb Z}_n, k)$. In fact, we show that for $k \geq 4$, the problem is only interesting in that it is strongly connected to the maximum size of $\ell$-AP-free sets in $[n]$ for appropriate $\ell = \ell(k)$. However, for $k = 3$ the situation is much stranger. We find logarithmic bounds on $\mathrm{aw}([n],3)$ but for $\mathrm{aw}({\mathbb Z}_n, 3)$ there is no such lower bound. In fact, $\mathrm{aw}(\mathbb{Z}_{2^m}, 3) = 3$ for all $m \geq 2$.
Many of these results were conjectured before they were proven, and these conjectures were formed by looking at data generated computationally. All of our data is available online. We now discuss algorithms for finding exact $r$-colorings of $[n]$ and $\mathbb{Z}_n$ that avoid rainbow $k$-APs.
### Computing $\mathrm{aw}([n],k)$
To determine $\mathrm{aw}([n],k)$, we design an algorithm that takes $n, k, r$ as input and determines whether or not there exists an exact $r$-coloring of $[n]$ that avoids rainbow $k$-APs. We can then start with $r = k$ and increase $r$ until no coloring exists, determining $\mathrm{aw}([n],k)$.
We shall use a standard backtracking search: fill in the values for the coloring $c : [n] \to [r]$ by assigning $c(0), c(1),\dots, c(n-1)$ in order. The trick is not in this part, but in how we prune the search tree.
One simple trick is that we will always use a lexicographic coloring: the first appearance of the color $p$ appears before the first appearance of the color $q$ if and only if $p < q$. This will immediately drop out $r!$ duplicate colorings. This is the only "symmetry calculation" we will perform, and it is very easy to do.
Initialize domains $D(i) = [r]$ for all $i \in [n]$. At every step, $D(i)$ will contain the colors that could be assigned to $c(i)$ without immediately creating a rainbow $k$-AP. Thus, when we assign a color to $c(i)$, we will search for any $k$-AP $A$ where exactly $k-1$ elements of $A$ are colored and these colors are distinct. If $j \in A$ is the only uncolored element in $A$, then we can restrict the domain as $D(j) \leftarrow D(j) \cap c(A\setminus j)$. Using only the domains, we can prune the search tree on these conditions:
• If $D(j) = \varnothing$ for any $j$, then prune (cannot color $j$!).
• If $\cup_{i\in [n]} D(i) \neq [r]$, then prune (cannot use all colors!).
With these pruning mechanisms, the algorithm will first deepen by coloring $n - r$ elements with $0$ before starting to use the larger colors. This is clearly non-optimal! So, we instead will use a trick: Assume we have pre-computed $\mathrm{aw}([m],k)$ for all $m < n$. This assumption is not unreasonable, since we are likely to compute all of these numbers in a row. (If we tried to parallelize the computation, this assumption may not be as reasonable.)
We add one more pruning mechanism:
• If $\{0,\dots,i\}$ is colored using only $\ell$ colors, then $\{i,\dots, n-1\}$ must be colored using $r-\ell+1$ colors. Hence, if $\mathrm{aw}([n-i], k) \leq r-\ell+1$, then prune.
With these reasonable pruning mechanisms, we were able to compute $\mathrm{aw}([n],3)$ for all $n \leq 58$ and $\mathrm{aw}([n],k)$ for all $k < n \leq 25$.
### Computing $\mathrm{aw}({\mathbb Z}_n,k)$
When transitioning to $\mathbb{Z}_n$, we can use a lot of the previous algorithm: domains, lexicographic coloring, etc. However, one thing we cannot use is the final pruning mechanism using previous values, since $\mathbb{Z}_m$ is not necessarily contained within $\mathbb{Z}_n$ for all $m < n$. Further, we need to be very careful about $k$-APs "crossing over zero" because of the modular arithmetic.
However, even with fewer pruning mechanisms, we were able to compute $\mathrm{aw}(\mathbb{Z}_n,3)$ for all $n < 100$ and $\mathrm{aw}(\mathbb{Z}_n,k)$ for all $k < n < 20$.
Why is this suddenly more efficient for computing exact colorings that avoid $3$-APs? The trick is that $\mathbb{Z}_n$ has more APs than $[n]$, and hence has more constraints! The increased number of constraints means that we will find a problem with our coloring earlier in the search tree, and hence the search tree is "skinnier" than in the $[n]$ case.
### Future Work
There are some algorithmic choices you can make, especially in the $\mathbb{Z}_n$ case, if a few conjectures are true. A singleton extremal coloring of $S$ is an exact coloring that avoids rainbow $k$-APs using $\mathrm{aw}(S,k)-1$ colors where one color class contains exactly one element.
Conjecture. For all $n > 3$, there exists a singleton extremal coloring of $[n]$ and $\mathbb{Z}_n$.
Assuming this conjecture, we could initialize our algorithm to have the singleton color class be the 0 color, at the 0 position. For $k = 3$, this actually creates even more possibilities for trimming domains, as we can immediately remove 0 from the domains of all other elements. I’ve done some initial testing with this assumption and found that we can calculate $\mathrm{aw}(\mathbb{Z}_n,3)$ for a few more values of $n$ beyond 100, but no more than 150 without parallelizing the algorithm, or waiting longer than 48 hours.
Are there more efficient algorithms? Can we get exact values without resorting to algorithms? | {"extraction_info": {"found_math": true, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 112, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0, "math_score": 0.8976651430130005, "perplexity": 308.94435134667174}, "config": {"markdown_headings": true, "markdown_code": true, "boilerplate_config": {"ratio_threshold": 0.18, "absolute_threshold": 10, "end_threshold": 15, "enable": true}, "remove_buttons": true, "remove_image_figures": true, "remove_link_clusters": true, "table_config": {"min_rows": 2, "min_cols": 3, "format": "plain"}, "remove_chinese": true, "remove_edit_buttons": true, "extract_latex": true}, "warc_path": "s3://commoncrawl/crawl-data/CC-MAIN-2021-39/segments/1631780056120.36/warc/CC-MAIN-20210918002951-20210918032951-00457.warc.gz"} |