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983,787 | https://en.wikipedia.org/wiki/Foreword | A foreword is a (usually short) piece of writing, sometimes placed at the beginning of a book or other piece of literature. Typically written by someone other than the primary author of the work, it often tells of some interaction between the writer of the foreword and the book's primary author or the story the book tells. Later editions of a book sometimes have a new foreword prepended (appearing before an older foreword if there was one), which might explain in what respects that edition differs from previous ones.
When written by the author, the foreword may cover the story of how the book came into being or how the idea for the book was developed, and may include thanks and acknowledgments to people who were helpful to the author during the time of writing. Unlike a preface, a foreword is always signed.
Information essential to the main text is generally placed in a set of explanatory notes, or perhaps in an introduction, rather than in the foreword or like preface.
The pages containing the foreword and preface (and other front matter) are typically not numbered as part of the main work, which usually uses Arabic numerals. If the front matter is paginated, it uses lowercase Roman numerals. If there is both a foreword and a preface, the foreword appears first; both appear before the introduction, which may be paginated either with the front matter or the main text.
The word foreword was first used around the mid-17th century, originally as a term in philology. It was possibly a calque of German Vorwort, itself a calque of Latin praefatio.
See also
Afterword
Epigraph
Introduction
Preface
Prologue
References
External links
The difference between a preface, foreword, and introduction – PatMcNees.com
Book design
Book terminology
Literature | Foreword | Engineering | 368 |
24,328,041 | https://en.wikipedia.org/wiki/Response%20reactions | The theory of response reactions (RERs) was elaborated for systems in which several physico-chemical processes run simultaneously in mutual interaction, with local thermodynamic equilibrium, and in which state variables called extents of reaction are allowed, but thermodynamic equilibrium proper is not required. It is based on detailed analysis of the Hessian determinant, using either the Gibbs or the De Donder method of analysis. The theory derives the sensitivity coefficient as the sum of the contributions of individual RERs. Thus phenomena which are in contradiction to over-general statements of the Le Chatelier principle can be interpreted. With the help of RERs the equilibrium coupling was defined. RERs could be derived based either on the species, or on the stoichiometrically independent reactions of a parallel system. The set of RERs is unambiguous in a given system; and the number of them (M) is , where S denotes the number of species and C refers to the number of components. In the case of three-component systems, RERs can be visualized on a triangle diagram.
References
Thermodynamics | Response reactions | Physics,Chemistry,Mathematics | 235 |
7,816,625 | https://en.wikipedia.org/wiki/Package-merge%20algorithm | The package-merge algorithm is an O(nL)-time algorithm for finding an optimal length-limited Huffman code for a given distribution on a given alphabet of size n, where no code word is longer than L. It is a greedy algorithm, and a generalization of Huffman's original algorithm. Package-merge works by reducing the code construction problem to the binary coin collector's problem.
The coin collector's problem
Suppose a coin collector has a number of coins of various denominations, each of which has a numismatic value unrelated to its denomination. The coin collector has run out of money and needs to use some of his coin collection to buy something of cost N. He wishes to select a subset of coins from his collection of minimum numismatic value whose denominations total N.
The binary version of this problem is that all denominations are powers of 2, that is, 1, 1/2, 1/4, etc. dollars.
Description of the package-merge algorithm
Assume that the largest denomination is 1 dollar, and that N is an integer. (The algorithm works even if these assumptions do not hold, by trivial modifications.) The coin collector first separates his coins into lists, one for each denomination, sorted by numismatic value. He then packages the smallest denomination coins in pairs, starting from the pair of smallest total numismatic value. If there is one coin left over, it will be the coin of highest numismatic value of that denomination, and it is set aside and ignored henceforth. These packages are then merged into the list of coins of the next smallest denomination, again in order of numismatic value. The items in that list are then packaged in pairs, and merged into the next smallest list, and so forth.
Finally, there is a list of items, each of which is a 1 dollar coin or a package consisting of two or more smaller coins whose denominations total 1 dollar. They are also sorted in order of numismatic value. The coin collector then selects the least value N of them.
Note that the time of the algorithm is linear in the number of coins.
Reduction of length-limited Huffman coding to the coin collector's problem
Let L be the maximum length any code word is permitted to have.
Let p1, …, pn be the frequencies of the
symbols of the alphabet to be encoded. We first sort the symbols so that pi ≤ pi+1. Create L coins for each symbol, of denominations 2−1, …, 2−L, each of numismatic value pi. Use the package-merge algorithm to select the set of coins of minimum numismatic value whose denominations total n − 1. Let hi be the number of coins of numismatic value pi selected.
The optimal length-limited Huffman code will encode symbol i with a bit string of length hi. The canonical Huffman code can easily be constructed by a simple bottom-up greedy method, given that the hi are known, and this can be the basis for fast data compression.
Performance improvements and generalizations
With this reduction, the algorithm is O(nL)-time and O(nL)-space. However, the original paper, "A fast algorithm for optimal length-limited Huffman codes", shows how this can be improved to O(nL)-time and O(n)-space. The idea is to run the algorithm a first time, only keeping enough data to be able to determine two equivalent subproblems that sum to half the size of the original problem. This is done recursively, resulting in an algorithm that takes about twice as long but requires only linear space.
Many other improvements have been made to the package-merge algorithm to reduce the multiplicative constant and to make it faster in special cases, such as those problems having repeated pis. The package-merge approach has also been adapted to related problems such as alphabetic coding.
Methods involving graph theory have been shown to have better asymptotic space complexity than the package-merge algorithm, but these have not seen as much practical application.
References
External links
An implementation of the package-merge algorithm ""
A fast entropy coder that uses package-merge algorithm
Lossless compression algorithms
Coding theory | Package-merge algorithm | Mathematics | 863 |
14,925,389 | https://en.wikipedia.org/wiki/Ras%20superfamily | The Ras superfamily, derived from "Rat sarcoma virus", is a protein superfamily of small GTPases. Members of the superfamily are divided into families and subfamilies based on their structure, sequence and function. The five main families are Ras, Rho, Ran, Rab and Arf GTPases. The Ras family itself is further divided into 6 subfamilies: Ras, Ral, Rap, Rheb, Rad and Rit. Miro is a recent contributor to the superfamily. Each subfamily shares the common core G domain, which provides essential GTPase and nucleotide exchange activity.
The surrounding sequence helps determine the functional specificity of the small GTPase, for example the 'Insert Loop', common to the Rho subfamily, specifically contributes to binding to effector proteins such as WASP.
In general, the Ras family is responsible for cell proliferation: Rho for cell morphology, Ran for nuclear transport, and Rab and Arf for vesicle transport.
Subfamilies and members
The following is a list of human proteins belonging to the Ras superfamily:
Unclassified:
ARHGAP5
DNAJC27
GRLF1
RASEF
See also
Ras subfamily
References
G proteins
Protein superfamilies | Ras superfamily | Chemistry,Biology | 259 |
1,254,336 | https://en.wikipedia.org/wiki/Applied%20ecology | Applied ecology is a sub-field within ecology that considers the application of the science of ecology to real-world (usually management) questions. It is also described as a scientific field that focuses on the application of concepts, theories, models, or methods of fundamental ecology to environmental problems.
Concept
Applied ecology is an integrated treatment of the ecological, social, and biotechnological aspects of natural resource conservation and management. Applied ecology typically focuses on geomorphology, soils, and plant communities as the underpinnings for vegetation and wildlife (both game and non-game) management.
Applied ecology includes all disciplines that are related to human activities so that it does not only cover agriculture, forestry and fisheries but also global change. It has two study categories. The first involves the outputs or those fields that address the use and management of the environment, particularly for its ecosystem services and exploitable resources. The second are the inputs or those that are concerned with the management strategies or human influences on the ecosystem or biodiversity.
The discipline is often linked to ecological management on the grounds that the effective management of natural ecosystems depends on ecological knowledge. It often uses an ecological approach to solve problems of specific parts of the environment, which can involve the comparison of plausible options (e.g. best management options).
The role of applied science in agricultural production has been brought into greater focus as fluctuations in global food production feed through into prices and availability to consumers.
Approaches
Applied ecologists often use one or more of the following approaches, namely, observation, experimentation, and modeling. For example, a wildlife preservation project could involve: observational studies of the wildlife ecology; experiments to understand causal relationships; and the application of modeling to determine the information beyond the scope of experimentation.
The ecological approach used in applied ecology could include inputs from management strategies such as conservation biology, restoration ecology, global change, ecotoxicology, biomonitoring, biodiversity, environmental policies, and economics, among others. Restoration ecology is a particularly prominent strategy in the discipline since it applies the principles of restoring and repairing damaged ecological systems to their original state.
Like those used in ecological theory, many areas of the discipline employ approaches that are based on simple statistical and analytic models (e.g. spatial models) as well as those with mathematical properties (e.g. matrix models). There is also the digital computer simulation modeling, which is designed to solve statistical ecology problems and to achieve bioeconomic goals such as the forecasting and the evaluation of consequences for specific activities.
Applied ecology also requires human interest, particularly the exercise of judgments of relative values and goals.
Applications
Applied ecology can be applied to the economic development process. The discipline, for example, can be integrated into the national economic planning to comprehensively address environmental concerns since these problems are intersectoral and interdisciplinary in nature.
Aspects of applied ecology include:
Agro-ecosystem management
Biodiversity conservation
Biotechnology
Conservation biology
Disturbance management
Ecosystem restoration
Environmental engineering
Environmental technology
Habitat management
Invasive species management
Landscape use (including development planning)
Protected areas management
Rangeland management
Restoration ecology
Wildlife management (including game)
Major journals in the field include:
Journal of Applied Ecology
Ecological Applications
Applied Ecology and Environmental Research
Related organizations include:
Ecological Society of America (The Americas)
Society for Ecological Restoration (Global)
Institute for Applied Ecology (USA)
Kazakh Agency of Applied Ecology
Öko-Institut (Institute for Applied Ecology) (in Germany)
See also
Holistic management
Natural environment
Natural resource
Nature
Environmental impact design
Landscape planning
References
Bibliography
External links
Ecology
Bioremediation
Ecology
Ecological restoration
Environmental design
Sustainable urban planning
Environmental planning
Environmental technology
Horticulture
Landscape architecture | Applied ecology | Chemistry,Engineering,Biology,Environmental_science | 726 |
56,896,664 | https://en.wikipedia.org/wiki/List%20of%20Fujitsu%20image%20scanners | Fujitsu manufactures two series of image scanners: ScanSnap for consumers/SOHO, and fi for business (fi includes SP brand). Popular ScanSnap models include the S1300, a feature-rich scanner that can scan double-sided color originals, and the S1100, one of the world's smallest scanners. By September 2018, ScanSnap had sold more than five million units globally since 2001, and the ScanSnap brand reached the age of twenty years on July 10, 2021.
The following is a selection of scanners manufactured under the Fujitsu brand.
Current models
Discontinued models (but still eligible for extended service coverage)
Previous models
ScanSnap S300 – portable scanner, 10 sheet ADF, 600 dpi optical resolution, 8 to 0.5 pages per minute depending on mode and AC availability
ScanSnap S300M – Macintosh version of S300 with similar specifications
ScanSnap S500
ScanSnap S500M
ScanSnap S510
ScanSnap S510M
ScanSnap S1100
ScanSnap S1300
ScanSnap S1500
ScanSnap S1500M
ScanSnap iX500 Deluxe
Other
SP-1425
References
Image scanners
Fujitsu image scanners | List of Fujitsu image scanners | Technology | 259 |
49,996,732 | https://en.wikipedia.org/wiki/Uztelecom | Uzbektelecom is a telecommunications company that provides services throughout Uzbekistan, with its headquarters situated in the capital city of Tashkent.
Uzbektelecom is a company that offers a range of data transmission services, including internet access, virtual private network (VPN) services, video conferencing, and the development and implementation of corporate networks. They also offer international telephone services through prepaid cards, which are made possible by the use of the international voice gateway VoIP. Uzbektelecom provides these services using dedicated lines that utilize xDSL and RadioEthernet technologies, as well as dial-up access.
Uzbektelecom JSC provides international telephone communication through two international switching centers, maintaining partnerships with international operators. The general brand of Uzbektelecom JSC has been the Uztelecom trademark since 2011. Through a single sales office, the Company provides subscribers with mobile communication services, Internet connection, television, city telephony, and cloud storage.
Uztelecom also includes a range of telecommunications services for the corporate sector: fixed telephony, wired and wireless broadband (broadband access), PD (data transmission), VPN (virtual private networks), IP telephony, IPTV, virtual office PBX, videoconferencing, mobile communications, mobile PD. The company also provides new generation telecommunications services for the retail sector and small businesses: services based on IP technologies — Internet access, IP telephony, IPTV, universal payment cards for IP telephony and Internet services, etc. At the same time, mobile communication services are provided based on the CDMA-450 and GSM standards.
Uzbektelecom JSC has stakes in eight joint ventures that provide mobile and fixed-line, long-distance and international communications, data transmission and Internet services.
Since November 18, 2013, Uzbektelecom JSC was awarded a certificate of compliance with the requirements of the O'z DSt ISO 9001:2009 (ISO 9001:2008) standard based on the results of the certification audit.
On January 12, 2017, Uzbektelecom JSC conducted a recertification audit and confirmed the certificate of compliance with the requirements of the O'z DSt ISO 9001:2009 (ISO 9001:2008).
In 2018, Uzbektelecom JSC successfully passed certification with the transition to the new version of The o'z DSt ISO 9001:2015 standard.
History
1992–2000
Uzbektelecom was established in 1992.
In 1995–1996, the state enterprise began to be privatized through the formation of multiple joint stock companies, including Uzbektelecom International. In 1997, the Ministry of Communications of the Republic of Uzbekistan was reorganized into the Uzbek Post and Telecommunications Agency, followed by the establishment of regional joint stock companies providing telecommunications services.
2000–2005
From 2000 through 2002, Uzbektelecom was reorganized from a holding company to an operating company, merging the regional telecommunications companies into Uzbektelecom.
In 2003, Uzbektelecom began providing CDMA-450 wireless radio access. As of 2003, the wireless radio access system was working in Samarkand and the Djizak regions. During the years 2004 and 2005, Uzbektelecom implemented improvements to enhance international telephone access and internet connectivity.
2006—present
As of 2007, mobile CDMA communication services were available in all regions of Uzbekistan. In 2011, Uzbektelecom was rebranded as Uztelecom, with sub-brands Uzmobile and Uzonline. In 2012 and 2013, Uztelecom continued to expand its coverage, providing CDMA wireless services to 71% of the country, and installing fiber-optic lines between cities within Uzbekistan and to international destinations.
In April 2023, Uztelecom began trialing its 5G network in the city of Tashkent in preparation for a full scale 5G rollout.
References
External links
Official website
Uzbekistan | Uztelecom | Technology | 829 |
51,121,181 | https://en.wikipedia.org/wiki/Topological%20Galois%20theory | In mathematics, topological Galois theory is a mathematical theory which originated from a topological proof of Abel's impossibility theorem found by Vladimir Arnold and concerns the applications of some topological concepts to some problems in the field of Galois theory. It connects many ideas from algebra to ideas in topology. As described in Askold Khovanskii's book: "According to this theory, the way the Riemann surface of an analytic function covers the plane of complex numbers can obstruct the representability of this function by explicit formulas. The strongest known results on the unexpressibility of functions by explicit formulas have been obtained in this way."
References
Galois theory
Topology | Topological Galois theory | Physics,Mathematics | 140 |
39,563,465 | https://en.wikipedia.org/wiki/List%20of%20open-source%20software%20for%20mathematics | This is a list of open-source software to be used for high-order mathematical calculations. This software has played an important role in the field of mathematics. Open-source software in mathematics has become pivotal in education because of the high cost of textbooks.
Computer algebra systems
A computer algebra system is a type of software set that is used in manipulation of mathematical formulae. The principal objective of a computer algebra system is to systematize monotonous and sometimes problematic algebraic manipulation tasks. The primary difference between a computer algebra system and a traditional calculator is the ability to deal with equations symbolically rather than numerically. The precise uses and capabilities of these systems differ greatly from one system to another, yet their purpose remains the same: manipulation of symbolic equations. Computer algebra system often include facilities for graphing equations and provide a programming language for the users' own procedures.
Axiom
Axiom is a general-purpose computer algebra system. It has been in development since 1971 by IBM, and was originally named scratchpad. Richard Jenks originally headed it but over the years Barry Trager who then shaped the direction of the scratchpad project took over the project. It was eventually sold to the Numerical Algorithms Group (NAG) and was renamed Axiom. After a failure to launch as a product, NAG decided to release it as a free software in 2001 with more than 300 man-years worth of research involved. Axiom is licensed under a Modified BSD license.
Cadabra
A Computer Algebra System designed for the solution of problems in field theory. An unpublished computational program written in Pascal called Abra inspired this open-source software. Abra was originally designed for physicists to compute problems present in quantum mechanics. Kespers Peeters then decided to write a similar program in C computing language rather than Pascal, which he renamed Cadabra. However, Cadabra has been expanded for a wider range of uses, it is no longer restricted to physicists.
CoCoA
CoCoA (COmputations in COmmutative Algebra) is open-source software used for computing multivariate polynomials and initiated in 1987. Originally written in Pascal, CoCoA was later translated into C.
GAP
GAP was initiated by RWTH Aachen University in 1986. This was the case until in 1997 when they decided to co-develop GAP further with CIRCA (Centre for Research in Computational Algebra). Unlike MAXIMA and Axiom, GAP is a system for computational discrete algebra with particular emphasis on computational group theory. In March 2005 the GAP Council and the GAP developers have agreed that status and responsibilities of "GAP Headquarters" should be passed to an equal collaboration of a number of "GAP Centres", where there is permanent staff involvement and an element of collective or organizational commitment, while fully recognizing the vital contributions of many individuals outside those centers.
Mathics
Mathics is an open-source GPL3 license version of the Wolfram Language.
Maxima
This free software had an earlier incarnation, Macsyma. Developed by Massachusetts Institute of Technology in the 1960s, it was maintained by William Schelter from 1982 to 2001. In 1998, Schelter obtained permission to release Maxima as open-source software under the GNU General Public license and the source code was released later that year. Since his death in 2001, a group of Maxima enthusiasts have continued to provide technical support.
PARI/GP
PARI/GP is a computer algebra system that facilitates number-theory computation. Besides support of factoring, algebraic number theory, and analysis of elliptic curves, it works with mathematical objects like matrices, polynomials, power series, algebraic numbers, and transcendental functions. Originally developed by Henri Cohen et al at Université Bordeaux I, France, it now is GPL software. The gp interactive shell allows GP-language scripting; the gp2c compiler compiles GP scripts into C; and the PARI C library allows C programs to use PARI/GP functions.
Sympy
Sympy is a computer algebra system written in Python.
Xcas
Xcas/Giac is an open-source project developed at the Joseph Fourier University of Grenoble since 2000. Written in C++, maintained by et al. and available for Windows, Mac, Linux and many others platforms. It has a compatibility mode with Maple, Derive and MuPAD software and TI-89, TI-92 and Voyage 200 calculators. The system was chosen by Hewlett-Packard as the CAS for their HP Prime calculator, which utilizes the Giac/Xcas 1.1.2 engine under a dual-license scheme.
Geometry
Geogebra
Geogebra (Geometry and Algebra) - combines geometric objects like circles and graphs of functions with its algebraic representation e.g. representing a circle with the radius . Designed for use in schools and educational settings.
Numerical analysis
Numerical analysis is an area of mathematics that creates and analyzes algorithms for obtaining numerical approximations to problems involving continuous variables. When an arbitrary function does not have a closed form as its solution, there would not be any analytical tools present to evaluate the desired solutions, hence an approximation method is employed instead.
FreeMat
FreeMat is an alternative to MATLAB.
GNU Scientific Library
The GNU Scientific Library (or GSL) is a software library for numerical computations in applied mathematics and science. The GSL is written in C and wrappers are available for other programming languages. The GSL is part of the GNU Project and is distributed under the GNU General Public License.
Octave
Octave (aka GNU Octave) is an alternative to MATLAB. Originally conceived in 1988 by John W. Eaton as a companion software for an undergraduate textbook, Eaton later opted to modify it into a more flexible tool. Development begun in 1992 and the alpha version was released in 1993. Subsequently, version 1.0 was released a year after that in 1994. Octave is a high level language with the primary intention in numerical computation.
Modelica
Modelica is an object-oriented, declarative, multi-domain modeling language for component-oriented modeling of complex systems including algebraic and differential equations. OpenModelica and Jmodelica are some of the opensource implementations of the language.
Scilab
Inspired by MATLAB, Scilab was initiated in the mid-1980s at the INRIA (French national Institute for computer science and control). François Delebecque and Serge Steer developed it and it was released by INRIA in 1994 as an open-source software. Since 2008, Scilab has been distributed under the CeCILL license, which is GPL compatible. In 2010, Scilab Enterprise was founded to provide even more support to the software.
SciPy
SciPy is a python programming language library to take advantage of Python's ability to handle large data sets.
Statistics
Statistics is the study of how to collate and interpret numerical information from data. It is the science of learning from data and communicating uncertainty. There are two branches in statistics: ‘Descriptive statistics’’ and ‘’ Inferential statistics
Descriptive statistics involves methods of organizing, picturing and summarizing information from data. Inferential statistics involves methods of using information from a sample to draw conclusions about the Population.
Alternatives to SPSS
R Statistics Software, SOFA Statistics, PSPP and JASP are open source software competitors to SPSS, widely used for statistical analysis of sampled data. PSPP is maintained by the GNU project. SOFA Statistics is addressing beginners with basic features, while GNU-R Statistics Software has a large community that maintains R packages also beyond statistical analysis.
R
R is both a language and software used for statistical computing and graphing. R was originally developed by Bell Laboratories (Currently known as Lucent Technologies) by John Chambers. Since R is largely written in C language, users can use C or C++ commands to manipulate R-objects directly. Also, R runs on most UNIX platforms. R is currently part of the Free Software Foundation GNU project.
Demetra+
Demetra is a program for seasonal adjustments that was developed and published by Eurostat – European Commission under the EUPL license.
Multipurpose mathematics software
Such software were created with the original intent of providing a math platform that can be compared to proprietary software such as MATLAB and Mathematica. They contain multiple other free software and hence have more features than the rest of the software mentioned.
SageMath
SageMath is designed partially as a free alternative to the general-purpose mathematics products Maple and MATLAB. It can be downloaded or used through a web site. SageMath comprises a variety of other free packages, with a common interface and language. SageMath is developed in Python.
SageMath was initiated by William Stein, of Harvard University in 2005 for his personal project in number theory. It was originally known as "HECKE and Manin". After a short while it was renamed SAGE, which stands for ‘’Software of Algebra and Geometry Experimentation’’. Sage 0.1 was released in 2005 and almost a year later Sage 1.0 was released. It already consisted of Pari, GAP, Singular and Maxima with an interface that rivals that of Mathematica.
Theorem provers
Recreational mathematics software
Golly
See also
List of open-source machine learning software
Comparison of deep-learning software
Comparison of numerical-analysis software
List of numerical-analysis software
List of graphing software
List of numerical libraries
List of statistical packages
Mathematical software
References
Mathematics open-source software | List of open-source software for mathematics | Mathematics,Technology | 1,910 |
49,253,215 | https://en.wikipedia.org/wiki/Zinc%20finger%20protein%20613 | Zinc finger protein 613 is a protein that in humans is encoded by the ZNF613 gene.
References
Further reading
Proteins | Zinc finger protein 613 | Chemistry | 28 |
73,169,871 | https://en.wikipedia.org/wiki/NOMe-seq | Nucleosome Occupancy and Methylome Sequencing (NOMe-seq) is a genomics technique used to simultaneously detect nucleosome positioning and DNA methylation... This method is an extension of bisulfite sequencing, which is the gold standard for determining DNA methylation. NOMe-seq relies on the methyltransferase M.CviPl, which methylates cytosines in GpC dinucleotides unbound by nucleosomes or other proteins, creating a nucleosome footprint. The mammalian genome naturally contains DNA methylation, but only at CpG sites, so GpC methylation can be differentiated from genomic methylation after bisulfite sequencing. This allows simultaneous analysis of the nucleosome footprint and endogenous methylation on the same DNA molecules. In addition to nucleosome foot-printing, NOMe-seq can determine locations bound by transcription factors. Nucleosomes are bound by 147 base pairs of DNA whereas transcription factors or other proteins will only bind a region of approximately 10-80 base pairs. Following treatment with M.CviPl, nucleosome and transcription factor sites can be differentiated based on the size of the unmethylated GpC region.
Nucleosome occupancy determines DNA accessibility, which provides insight into regulatory regions of the genome. Important regulatory elements within a cell (such as promoters, enhancers, silencers, etc.), are located in open or accessible regions to allow binding of transcription factors or other regulatory molecules. NOMe-seq can therefore be used to elucidate regulatory information. Alternative DNA accessibility techniques include MNase-seq, DNase-seq, FAIRE-seq, and their successor ATAC-seq. NOMe-seq has the additional benefit of providing DNA methylation status, which also plays a crucial role in the regulation of genomic activity. Interestingly, increased DNA methylation is associated with transcriptional silencing whereas accessible DNA unbound by nucleosomes is generally associated with transcriptional activation. In this sense, NOMe-seq consists of two independent methylation analyses that are functionally oppositional.
History
The M.CviPl methyltransferase was first described in 1998, where the gene was cloned from Chorella virus NYs-1. After its discovery, the methyltransferase was used for nucleosome foot-printing as early as 2004, but NOMe-seq was not officially described until 2012. M.CviPl was not the only methyltransferase used for nucleosome foot-printing; Methylase-sensitive Single Promoter Analysis (M-SPA) was described in 2005 using the CpG methyltransferase M.Sssi. M.CviPl techniques quickly overtook M-SPA as GpC specificity is preferable to CpG specificity, with GpC dinucleotides having a broader distribution throughout the genome and no endogenous methylation. The NOMe-seq assay was subsequently developed, with the earliest mention being in 2011 and an in depth description published in 2012. The technique has since been adapted for single cell technologies, with single cell NOMe-seq (scNOMe-seq) described in 2017 and NOMe-seq using nanopore sequencing (nanoNOMe) described in 2020. These adaptations have allowed high resolution analyses that can compare and contrast DNA accessibility between single cells.
Methods
Components
For isolating nuclei, components include Dulbecco's phosphate-buffered saline (DPBS), trypsin or dispase (depending on cell type), trypan blue, hemocytometer, lysis buffer, and wash buffer
To treat nuclei with M.CviPl, components include GpC Buffer, S-adenosylhomocysteine (SAM), M.CviPl, Sucrose, Nuclease-free water, and Stop buffer
For isolating M.CviPl-treated DNA, components include NaCl, Proteinase K, Phenol:Chloroform (1:1), Ethanol, TE Buffer, and Nandrop spectrophotometer EDTA pH 8
For fragmenting M.CviPI-treated DNA, components include Covaris sonicator, Covaris MicroTUBE AFA Pre-slit Snap-Cap 6x16mm, Nanodrop Spectrophotometer, and DNA High Sensitivity Kit (Agilent) for use with Agilent 2100 Bioanalyzer
For bisulfite conversion of M.CviPI-treated DNA, components include EZ DNA Methylation Kit
For constructing NOMe-seq Library, components include Accel-NGS Methyl-Seq DNA Library Kit for Illumina Platforms, Methyl-Seq Set A Indexing Kit, Magnetic Beads, dsDNA HS Assay Kit, and DNA High Sensitivity Kit
Workflow
Isolate Nuclei: Lysation of pelleted cells
Treat Nuclei with M. CviPl to Methylate GpCs: Incubation with GpC buffer and M.CviPI
Purify and Fragment MCviPl-treated Nuclei
Treat MCviPI-treated Nuclei with Bisulfite: Conversion of unmethylated Cs to Ts
Construct NOME-seq library
Sequence NOMe-seq Library
Perform Quality Check: Analysis of the sequence by aligning the sequenced genomic clones to bisulfite converted sequence
Post-process: Analysis of duplicates and coverage quality
Call for Methylation at CpG and GpC sites: CpG is found in all HCG trinucleotides; GpC is found in all GCH trinucleotides
Call for NDRs
Perform Quality Analysis of methylation and NDRs identification: Visualization of methylation levels
Use
Advantages
High resolution
Identifies regulatory elements without needing to understand nucleosome modifications (in comparison to CHIP-seq)
Greater depth regarding the position of nucleosomes (comparison to DNase-seq, FAIRE-seq, and ATAC-seq.
Identifies information on dual nucleosome position
Identifies DNA methylation at a single-DNA molecule resolution
Relatively short reaction time: 15 minutes while utilizing approximately 200,000 cells.
Limitations
Relies on the presence of GpC residues: while the broad distribution of GpCs provides high depth information, mapping is still based on GpC presence in regions unbound by nucleosomes or transcription factors and therefore can not provide single nucleotide resolution
Higher expense compared to other sequencing methods due to the depth in information generated
Other Applications & Complementary Methods
scNOMe-seq
scNOMe-seq is a method that was adapted from NOMe-seq to be used in single cells studies. This has been found to produce similar results as NOMe-seq when using bulk samples of human cell cultures. Single cell analyses have many benefits in cases where gene expression can vary between cells. For example, to further develop cancer treatments, it would be useful to understand the differences that arise between individual cells using the scNOMe-seq method.
nanoNOMe
nanoNOMe is a method that was adapted from NOMe-seq that uses nanopore sequencing instead of bisulfite sequencing. Nanopore sequencing is a long read sequencing method that also detects DNA methylation, providing additional insight into longe range patterns on individual molecules.
NOMePlot
NOMePlot is a bioinformatic tool that was developed for datasets derived by NOMe-seq. This tool easily obtains single molecule locus-specific information in genome-wide datasets from bulk cell populations and has been validated using mouse embryonic stem cells.
See also
Pore-C
References
DNA sequencing
Molecular biology techniques | NOMe-seq | Chemistry,Biology | 1,613 |
15,364,270 | https://en.wikipedia.org/wiki/Cunningham%20number | In mathematics, specifically in number theory, a Cunningham number is a certain kind of integer named after English mathematician A. J. C. Cunningham.
Definition
Cunningham numbers are a simple type of binomial number – they are of the form
where b and n are integers and b is not a perfect power. They are denoted C±(b, n).
Terms
The first fifteen terms in the sequence of Cunningham numbers are:
3, 5, 7, 8, 9, 10, 15, 17, 24, 26, 28, 31, 33, 35, 37, ...
Properties
There are infinitely many even and odd Cunningham numbers. Provable through observation that the infinite series
are both contained within the Cunningham numbers, and contain only Odd and Even numbers respectively.
By the same logic, there are Infinitely many Cunningham numbers which are 7 modulo 10, and same for 6 modulo 10.
Primality
Establishing whether or not a given Cunningham number is prime has been the main focus of research around this type of number. Two particularly famous families of Cunningham numbers in this respect are the Fermat numbers, which are those of the form C+(2, 2m), and the Mersenne numbers, which are of the form C−(2, n).
Cunningham worked on gathering together all known data on which of these numbers were prime. In 1925 he published tables which summarised his findings with H. J. Woodall, and much computation has been done in the intervening time to fill these tables.
See also
Cunningham project
References
External links
Cunningham Number at MathWorld
The Cunningham Project, a collaborative effort to factor Cunningham numbers
Number theory | Cunningham number | Mathematics | 334 |
34,367,319 | https://en.wikipedia.org/wiki/NGC%203259 | NGC 3259 is a barred spiral galaxy located approximately 90 million light-years from Earth, in the Ursa Major constellation. It has the morphological classification SAB(rs)bc, which indicates that it is a spiral galaxy with a weak bar across the nucleus (SAB), an incomplete inner ring structure circling the bar (rs), and moderate to loosely wound spiral arms (bc). This galaxy is a known source of X-ray emission and it has an active galactic nucleus of the Seyfert 2 type.
References
Barred spiral galaxies
3259
17910403
Ursa Major
031145 | NGC 3259 | Astronomy | 125 |
3,722 | https://en.wikipedia.org/wiki/Berlin%20Wall | The Berlin Wall (, ) was a guarded concrete barrier that encircled West Berlin from 1961 to 1989, separating it from East Berlin and the German Democratic Republic (GDR; East Germany). Construction of the Berlin Wall was commenced by the government of the GDR on 13 August 1961. It included guard towers placed along large concrete walls, accompanied by a wide area (later known as the "death strip") that contained anti-vehicle trenches, beds of nails and other defenses. The primary intention for the Wall's construction was to prevent East German citizens from fleeing to the West.
The Soviet Bloc propaganda portrayed the Wall as protecting its population from "fascist elements conspiring to prevent the will of the people" from building a communist state in the GDR. The authorities officially referred to the Berlin Wall as the Anti-Fascist Protection Rampart (, ). Conversely, West Berlin's city government sometimes referred to it as the "Wall of Shame", a term coined by mayor Willy Brandt in reference to the Wall's restriction on freedom of movement. Along with the separate and much longer inner German border, which demarcated the border between East and West Germany, it came to symbolize physically the Iron Curtain that separated the Western Bloc and Soviet satellite states of the Eastern Bloc during the Cold War.
Before the Wall's erection, 3.5 million East Germans circumvented Eastern Bloc emigration restrictions and defected from the GDR, many by crossing over the border from East Berlin into West Berlin; from there they could then travel to West Germany and to other Western European countries. Between 1961 and 1989, the deadly force associated with the Wall prevented almost all such emigration. During this period, over 100,000 people attempted to escape, and over 5,000 people succeeded in escaping over the Wall, with an estimated death toll of those murdered by East German authorities ranging from 136 to more than 200 in and around Berlin.
In 1989, a series of revolutions in nearby Eastern Bloc countries (Poland and Hungary in particular) and the events of the "Pan-European Picnic" set in motion a peaceful development during which the Iron Curtain largely broke, rulers in the East came under public pressure to cease their repressive policies. After several weeks of civil unrest, the East German government announced on 9 November 1989 that all GDR citizens could visit the FRG and West Berlin. Crowds of East Germans crossed and climbed onto the Wall, joined by West Germans on the other side, and souvenir hunters chipped away parts of the Wall over the next few weeks. The Brandenburg Gate, a few meters from the Berlin Wall, reopened on 22 December 1989, with demolition of the Wall beginning on 13 June 1990 and concluding in 1994. The fall of the Berlin Wall paved the way for German reunification, which formally took place on 3 October 1990.
Background
Post-war Germany
After the end of World War II in Europe, what remained of pre-war Germany west of the Oder-Neisse line was divided into four occupation zones (as per the Potsdam Agreement), each one controlled by one of the four occupying Allied powers: the United States, the United Kingdom, France and the Soviet Union. The capital, Berlin, as the seat of the Allied Control Council, was similarly subdivided into four sectors despite the city's location, which was fully within the Soviet zone.
Within two years, political divisions increased between the Soviets and the other occupying powers. These included the Soviets' refusal to agree to reconstruction plans making post-war Germany self-sufficient, and to a detailed accounting of industrial plants, goods and infrastructure—some of which had already been removed by the Soviets. France, the United Kingdom, the United States, and the Benelux countries later met to combine the non-Soviet zones of Germany into one zone for reconstruction, and to approve the extension of the Marshall Plan.
Eastern Bloc and the Berlin airlift
Following the defeat of Nazi Germany in World War II, the Soviet Union engineered the installation of communist regimes in most of the countries occupied by Soviet military forces at the end of the War, including Poland, Hungary, Czechoslovakia, Bulgaria, Romania, and the GDR, which together with Albania formed the Comecon in 1949 and later a military alliance, the Warsaw Pact. The beginning of the Cold War saw the Eastern Bloc of the Soviet Union confront the Western Bloc of the United States, with the latter grouping becoming largely united in 1949 under NATO and the former grouping becoming largely united in 1955 under the Warsaw Pact. As the Soviet Union already had an armed presence and political domination all over its eastern satellite states by 1955, the pact has been long considered "superfluous", and because of the rushed way in which it was conceived, NATO officials labeled it a "cardboard castle". There was no direct military confrontation between the two organizations; instead, the conflict was fought on an ideological basis and through proxy wars. Both NATO and the Warsaw Pact led to the expansion of military forces and their integration into the respective blocs. The Warsaw Pact's largest military engagement was the Warsaw Pact invasion of Czechoslovakia, its own member state, in August 1968.
Since the end of the War, the USSR installed a Soviet-style regime in the Soviet occupation zone of Germany and later founded the GDR, with the country's political system based on a centrally planned socialist economic model with nationalized means of production, and with repressive secret police institutions, under party dictatorship of the SED (Sozialistische Einheitspartei Deutschlands; Socialist Unity Party of Germany) similar to the party dictatorship of the Soviet Communist Party in the USSR.
At the same time, a parallel country was established under the control of the Western powers in the zones of post-war Germany occupied by them, culminating in the foundation of the Federal Republic of Germany in 1949, which initially claimed to be the sole legitimate power in all of Germany, East and West. The material standard of living in the Western zones of Berlin began to improve quickly, and residents of the Soviet zone soon began leaving for the West in large numbers, fleeing hunger, poverty and repression in the Soviet Zone for a better life in the West. Soon residents of other parts of the Soviet zone began to escape to the West through Berlin, and this migration, called in Germany "Republikflucht", deprived the Soviet zone not only of working forces desperately needed for post-war reconstruction but disproportionately of highly educated people, which came to be known as the "Brain Drain".
In 1948, in response to moves by the Western powers to establish a separate, federal system of government in the Western zones, and to extend the US Marshall Plan of economic assistance to Germany, the Soviets instituted the Berlin Blockade, preventing people, food, materials and supplies from arriving in West Berlin by land routes through the Soviet zone. The United States, the United Kingdom, France, Canada, Australia, New Zealand and several other countries began a massive "airlift", supplying West Berlin with food and other supplies. The Soviets mounted a public relations campaign against the Western policy change. Communists attempted to disrupt the elections of 1948, preceding large losses therein, while 300,000 Berliners demonstrated for the international airlift to continue. In May 1949, Stalin lifted the blockade, permitting the resumption of Western shipments to Berlin.
The German Democratic Republic (the "GDR"; East Germany) was declared on 7 October 1949. On that day, the USSR ended the Soviet military government which had governed the Soviet Occupation Zone (Sowetische Besatzungszone) since the end of the War and handed over legal power to the Provisorische Volkskammer under the new Constitution of the GDR which came into force that day. However, until 1955, the Soviets maintained considerable legal control over the GDR state, including the regional governments, through the Sowetische Kontrollkommission and maintained a presence in various East German administrative, military, and secret police structures. Even after legal sovereignty of the GDR was restored in 1955, the Soviet Union continued to maintain considerable influence over administration and lawmaking in the GDR through the Soviet embassy and through the implicit threat of force which could be exercised through the continuing large Soviet military presence in the GDR, which was used to repress protests in East Germany bloodily in June 1953.
East Germany differed from West Germany (Federal Republic of Germany), which developed into a Western capitalist country with a social market economy and a democratic parliamentary government. Continual economic growth starting in the 1950s fueled a 20-year "economic miracle" (). As West Germany's economy grew, and its standard of living steadily improved, many East Germans wanted to move to West Germany.
Emigration westward in the early 1950s
After the Soviet occupation of Eastern Europe at the end of World War II, the majority of those living in the newly acquired areas of the Eastern Bloc aspired to independence and wanted the Soviets to leave. Taking advantage of the zonal border between occupied zones in Germany, the number of GDR citizens moving to West Germany totaled 187,000 in 1950; 165,000 in 1951; 182,000 in 1952; and 331,000 in 1953. One reason for the sharp 1953 increase was fear of potential further Sovietization, given the increasingly paranoid actions of Joseph Stalin in late 1952 and early 1953. In the first six months of 1953, 226,000 had fled.
Erection of the inner German border
By the early 1950s, the Soviet approach to controlling national movement, restricting emigration, was emulated by most of the rest of the Eastern Bloc, including East Germany. The restrictions presented a quandary for some Eastern Bloc states, which had been more economically advanced and open than the Soviet Union, such that crossing borders seemed more natural—especially where no prior border existed between East and West Germany.
Up until 1952, the demarcation lines between East Germany and the western occupied zones could be easily crossed in most places. On 1 April 1952, East German leaders met the Soviet leader Joseph Stalin in Moscow; during the discussions, Stalin's foreign minister Vyacheslav Molotov proposed that the East Germans should "introduce a system of passes for visits of West Berlin residents to the territory of East Berlin [so as to stop] free movement of Western agents" in the GDR. Stalin agreed, calling the situation "intolerable". He advised the East Germans to build up their border defenses, telling them that "The demarcation line between East and West Germany should be considered a border—and not just any border, but a dangerous one ... The Germans will guard the line of defence with their lives."
Consequently, the inner German border between the two German states was closed, and a barbed-wire fence erected. The border between the Western and Eastern sectors of Berlin, however, remained open, although traffic between the Soviet and the Western sectors was somewhat restricted. This resulted in Berlin becoming a magnet for East Germans desperate to escape life in the GDR, and also a flashpoint for tension between the United States and the Soviet Union.
In 1955, the Soviets gave East Germany authority over civilian movement in Berlin, passing control to a regime not recognized in the West. Initially, East Germany granted "visits" to allow its residents access to West Germany. However, following the defection of large numbers of East Germans (known as Republikflucht) under this regime, the new East German state legally restricted virtually all travel to the West in 1956. Soviet East German ambassador Mikhail Pervukhin observed that "the presence in Berlin of an open and essentially uncontrolled border between the socialist and capitalist worlds unwittingly prompts the population to make a comparison between both parts of the city, which unfortunately does not always turn out in favour of Democratic [East] Berlin."
Berlin emigration loophole
With the closing of the inner German border officially in 1952, the border in Berlin remained considerably more accessible because it was administered by all four occupying powers. Accordingly, Berlin became the main route by which East Germans left for the West. On 11 December 1957, East Germany introduced a new passport law that reduced the overall number of refugees leaving Eastern Germany.
It had the unintended result of drastically increasing the percentage of those leaving through West Berlin from 60% to well over 90% by the end of 1958. Those caught trying to leave East Berlin were subjected to heavy penalties, but with no physical barrier and subway train access still available to West Berlin, such measures were ineffective. The Berlin sector border was essentially a "loophole" through which Eastern Bloc citizens could still escape. The 3.5 million East Germans who had left by 1961 totalled approximately 20% of the entire East German population.
An important reason that passage between East Germany and West Berlin was not stopped earlier was that doing so would cut off much of the railway traffic in East Germany. Construction of a new railway bypassing West Berlin, the Berlin outer ring, commenced in 1951. Following the completion of the railway in 1961, closing the border became a more practical proposition.
Brain drain
The emigrants tended to be young and well-educated, leading to the "brain drain" feared by officials in East Germany. Yuri Andropov, then the CPSU Director on Relations with Communist and Workers' Parties of Socialist Countries, wrote an urgent letter on 28 August 1958 to the Central Committee about the significant 50% increase in the number of East German intelligentsia among the refugees. Andropov reported that, while the East German leadership stated that they were leaving for economic reasons, testimony from refugees indicated that the reasons were more political than material. He stated "the flight of the intelligentsia has reached a particularly critical phase."
By 1960, the combination of World War II and the massive emigration westward left East Germany with only 61% of its population of working age, compared to 70.5% before the war. The loss was disproportionately heavy among professionals: engineers, technicians, physicians, teachers, lawyers, and skilled workers. The direct cost of manpower losses to East Germany (and corresponding gain to the West) has been estimated at $7 billion to $9 billion, with East German party leader Walter Ulbricht later claiming that West Germany owed him $17 billion in compensation, including reparations as well as manpower losses. In addition, the drain of East Germany's young population potentially cost it over 22.5 billion marks in lost educational investment. The brain drain of professionals had become so damaging to the political credibility and economic viability of East Germany that the re-securing of the German communist frontier was imperative.
The exodus of emigrants from East Germany presented two minor potential benefits: an easy way to smuggle East German secret agents to West Germany, and a reduction in the number of citizens hostile to the communist regime. Neither of these advantages, however, proved particularly useful.
Start of the construction (1961)
On 15 June 1961, First Secretary of the Socialist Unity Party and GDR State Council chairman Walter Ulbricht stated in an international press conference, (No one has the intention of erecting a wall!). It was the first time the colloquial term (wall) had been used in this context.
The transcript of a telephone call between Nikita Khrushchev and Ulbricht, on 1 August in the same year, suggests that the initiative for the construction of the Wall came from Khrushchev. However, other sources suggest that Khrushchev had initially been wary about building a wall, fearing negative Western reaction. Nevertheless, Ulbricht had pushed for a border closure for some time, arguing that East Germany's existence was at stake.
Khrushchev had become emboldened upon seeing US president John F. Kennedy's youth and inexperience, which he considered a weakness. In the 1961 Vienna summit, Kennedy made the error of admitting that the US would not actively oppose the building of a barrier. A feeling of miscalculation and failure immediately afterwards was admitted by Kennedy in a candid interview with New York Times columnist James "Scotty" Reston. On Saturday, 12 August 1961, the leaders of the GDR attended a garden party at a government guesthouse in , in a wooded area to the north of East Berlin. There, Ulbricht signed the order to close the border and erect a wall.
At midnight, the police and units of the East German army began to close the border and, by Sunday morning, 13 August, the border with West Berlin was closed. East German troops and workers had begun to tear up streets running alongside the border to make them impassable to most vehicles and to install barbed wire entanglements and fences along the around the three western sectors, and the that divided West and East Berlin. The date of 13 August became commonly referred to as Barbed Wire Sunday in Germany.
The barrier was built inside East Berlin on East German territory to ensure that it did not encroach on West Berlin at any point. Generally, the Wall was only slightly inside East Berlin, but in a few places it was some distance from the legal border, most notably at Potsdamer Bahnhof and the Lenné Triangle that is now much of the Potsdamer Platz development.
Later, the initial barrier was built up into the Wall proper, the first concrete elements and large blocks being put in place on 17 August. During the construction of the Wall, National People's Army (NVA) and Combat Groups of the Working Class (KdA) soldiers stood in front of it with orders to shoot anyone who attempted to defect. Additionally, chain fences, walls, minefields and other obstacles were installed along the length of East Germany's western border with West Germany proper. A wide no man's land was cleared as well to provide a better overview and a clear line of fire at fleeing refugees.
Immediate effects
With the closing of the east–west sector boundary in Berlin, the vast majority of East Germans could no longer travel or emigrate to West Germany. Berlin soon went from being the easiest place to make an unauthorized crossing between East and West Germany to being the most difficult. Many families were split, while East Berliners employed in the West were cut off from their jobs. West Berlin became an isolated exclave in a hostile land. West Berliners demonstrated against the Wall, led by their Mayor () Willy Brandt, who criticized the United States for failing to respond and went so far as to suggest to Washington what to do next. Kennedy was furious. Allied intelligence agencies had hypothesized about a wall to stop the flood of refugees, but the main candidate for its location was around the perimeter of the city. In 1961, Secretary of State Dean Rusk proclaimed, "The Wall certainly ought not to be a permanent feature of the European landscape. I see no reason why the Soviet Union should think it is to their advantage in any way to leave there that monument to communist failure."
United States and UK sources had expected the Soviet sector to be sealed off from West Berlin but were surprised by how long the East Germans took for such a move. They considered the Wall as an end to concerns about a GDR/Soviet retaking or capture of the whole of Berlin; the Wall would presumably have been an unnecessary project if such plans were afloat. Thus, they concluded that the possibility of a Soviet military conflict over Berlin had decreased.
The East German government claimed that the Wall was an "anti-fascist protective rampart" () intended to dissuade aggression from the West. Another official justification was the activities of Western agents in Eastern Europe. The Eastern German government also claimed that West Berliners were buying out state-subsidized goods in East Berlin. East Germans and others greeted such statements with skepticism, as most of the time, the border was only closed for citizens of East Germany traveling to the West, but not for residents of West Berlin travelling to the East. The construction of the Wall had caused considerable hardship to families divided by it. Most people believed that the Wall was mainly a means of preventing the citizens of East Germany from entering or fleeing to West Berlin.
Secondary response
The National Security Agency was the only American intelligence agency that was aware that East Germany was to take action to deal with the brain drain problem. On 9 August 1961, the NSA intercepted an advance warning information of the Socialist Unity Party's plan to close the intra-Berlin border between East and West Berlin completely for foot traffic. The interagency intelligence Berlin Watch Committee assessed that this intercept "might be the first step in a plan to close the border." This warning did not reach John F. Kennedy until noon on 13 August 1961, while he was vacationing in his yacht off the Kennedy Compound in Hyannis Port, Massachusetts. While Kennedy was angry that he had no advance warning, he was relieved that the East Germans and the Soviets had only divided Berlin without taking any action against West Berlin's access to the West. However, he denounced the Berlin Wall, whose erection worsened the relations between the United States and the Soviet Union.
In response to the erection of the Berlin Wall, a retired general, Lucius D. Clay, was appointed by Kennedy as his special advisor with ambassadorial rank. Clay had been the Military Governor of the US Zone of Occupation in Germany during the period of the Berlin Blockade and had ordered the first measures in what became the Berlin Airlift. He was immensely popular with the residents of West Berlin, and his appointment was an unambiguous sign that Kennedy would not compromise on the status of West Berlin. As a symbolic gesture, Kennedy sent Clay and Vice President Lyndon B. Johnson to West Berlin. They landed at Tempelhof Airport on the afternoon of Saturday, 19 August 1961 and were greeted enthusiastically by the local population.
They arrived in a city defended by three Allied brigades—one each from the UK (Berlin Infantry Brigade), the US (Berlin Brigade), and France (Forces Françaises à Berlin). On 16 August, Kennedy had given the order for them to be reinforced. Early on 19 August, the 1st Battle Group, 18th Infantry Regiment (commanded by Colonel Glover S. Johns Jr.) was alerted.
On Sunday morning, U.S. troops marched from West Germany through East Germany, bound for West Berlin. Lead elements—arranged in a column of 491 vehicles and trailers carrying 1,500 men, divided into five march units—left the Helmstedt-Marienborn checkpoint at 06:34. At Marienborn, the Soviet checkpoint next to Helmstedt on the West German-East German border, US personnel were counted by guards. The column was long, and covered from Marienborn to Berlin in full battle gear. East German police watched from beside trees next to the autobahn all the way along.
The front of the convoy arrived at the outskirts of Berlin just before noon, to be met by Clay and Johnson, before parading through the streets of Berlin in front of a large crowd. At 04:00 on 21 August, Lyndon Johnson left West Berlin in the hands of General Frederick O. Hartel and his brigade of 4,224 officers and men. "For the next three and a half years, American battalions would rotate into West Berlin, by autobahn, at three-month intervals to demonstrate Allied rights to the city".
The creation of the Wall had important implications for both German states. By stemming the exodus of people from East Germany, the East German government was able to reassert its control over the country: despite discontent with the Wall, economic problems caused by dual currency and the black market were largely eliminated. The economy in the GDR began to grow. However, the Wall proved a public relations disaster for the communist bloc as a whole. Western powers portrayed it as a symbol of communist tyranny, particularly after East German border guards shot and killed would-be defectors. Such fatalities were later treated as acts of murder by the reunified Germany.
Structure and adjacent areas
Layout and modifications
The Berlin Wall was more than long. In June 1962, a second, parallel fence, also known as a "hinterland" wall (inner wall), was built some farther into East German territory. The houses contained between the wall and fences were razed and the inhabitants relocated, thus establishing what later became known as the death strip. The death strip was covered with raked sand or gravel, rendering footprints easy to notice, easing the detection of trespassers and also enabling officers to see which guards had neglected their task; it offered no cover; and, most importantly, it offered clear fields of fire for the Wall guards.
Through the years, the Berlin Wall evolved through four versions:
Wire fence and concrete block wall (1961)
Improved wire fence (1962–1965)
Improved concrete wall (1965–1975)
(Border Wall 75) (1975–1989)
The "fourth-generation Wall", known officially as "" (retaining wall element UL 12.11), was the final and most sophisticated version of the Wall. Begun in 1975 and completed about 1980, it was constructed from 45,000 separate sections of reinforced concrete, each high and wide, and cost DDM16,155,000 or about US$3,638,000. The concrete provisions added to this version of the Wall were done to prevent escapees from driving their cars through the barricades. At strategic points, the Wall was constructed to a somewhat weaker standard, so that East German and Soviet armored vehicles could easily break through in the event of war.
The top of the wall was lined with a smooth pipe, intended to make it more difficult to scale. The Wall was reinforced by mesh fencing, signal fencing, anti-vehicle trenches, barbed wire, dogs on long lines, "beds of nails" (also known as "Stalin's Carpet") under balconies hanging over the "death strip", over 116 watchtowers, and 20 bunkers with hundreds of guards. This version of the Wall is the one most commonly seen in photographs, and surviving fragments of the Wall in Berlin and elsewhere around the world are generally pieces of the fourth-generation Wall. The layout came to resemble the inner German border in most technical aspects, except that the Berlin Wall had no landmines nor spring-guns. Maintenance was performed on the outside of the wall by personnel who accessed the area outside it either via ladders or via hidden doors within the wall. These doors could not be opened by a single person, needing two separate keys in two separate keyholes to unlock.
As was the case with the inner German border, an unfortified strip of Eastern territory was left outside the wall. This outer strip was used by workers to paint over graffiti and perform other maintenance on the outside of the wall Unlike the inner German border, however, the outer strip was usually no more than four meters wide, and, in photos from the era, the exact location of the actual border in many places appears not even to have been marked. Also in contrast with the inner German border, little interest was shown by East German law enforcement in keeping outsiders off the outer strip; sidewalks of West Berlin streets even ran inside it.
Despite the East German government's general policy of benign neglect, vandals were known to have been pursued in the outer strip, and even arrested. In 1986, defector and political activist Wolfram Hasch and four other defectors were standing inside the outer strip defacing the wall when East German personnel emerged from one of the hidden doors to apprehend them. All but Hasch escaped back into the western sector. Hasch himself was arrested, dragged through the door into the death strip, and later convicted of illegally crossing the de jure border outside the wall. Graffiti artist Thierry Noir has reported having often been pursued there by East German soldiers. While some graffiti artists were chased off the outer strip, others, such as Keith Haring, were seemingly tolerated.
Surrounding municipalities
Besides the sector-sector boundary within Berlin itself, the Wall also separated West Berlin from the present-day state of Brandenburg. The following present-day municipalities, listed in counter-clockwise direction, share a border with the former West Berlin:
Oberhavel: Mühlenbecker Land (partially), Glienicke/Nordbahn, Hohen Neuendorf, Hennigsdorf
Havelland: Schönwalde-Glien, Falkensee, Dallgow-Döberitz
Potsdam (urban district)
Potsdam-Mittelmark: Stahnsdorf, Kleinmachnow, Teltow
Teltow-Fläming: Großbeeren, Blankenfelde-Mahlow
Dahme-Spreewald: Schönefeld (partially)
Official crossings and usage
There were nine border crossings between East and West Berlin. These allowed visits by West Berliners, other West Germans, Western foreigners and Allied personnel into East Berlin, as well as visits by GDR citizens and citizens of other socialist countries into West Berlin, provided that they held the necessary permits. These crossings were restricted according to which nationality was allowed to use it (East Germans, West Germans, West Berliners, other countries). The best known was the vehicle and pedestrian checkpoint at the corner of Friedrichstraße and Zimmerstraße (Checkpoint Charlie), which was restricted to Allied personnel and foreigners.
Several other border crossings existed between West Berlin and surrounding East Germany. These could be used for transit between West Germany and West Berlin, for visits by West Berliners into East Germany, for transit into countries neighbouring East Germany (Poland, Czechoslovakia, and Denmark), and for visits by East Germans into West Berlin carrying a permit. After the 1972 agreements, new crossings were opened to allow West Berlin waste to be transported into East German dumps, as well as some crossings for access to West Berlin's exclaves (see Steinstücken).
Four autobahns connected West Berlin to West Germany, including Berlin-Helmstedt autobahn, which entered East German territory between the towns of Helmstedt and Marienborn (Checkpoint Alpha), and which entered West Berlin at Dreilinden (Checkpoint Bravo for the Allied forces) in southwestern Berlin. Access to West Berlin was also possible by railway (four routes) and by boat for commercial shipping via canals and rivers.
Non-German Westerners could cross the border at Friedrichstraße station in East Berlin and at Checkpoint Charlie. When the Wall was erected, Berlin's complex public transit networks, the S-Bahn and U-Bahn, were divided with it. Some lines were cut in half; many stations were shut down. Three western lines traveled through brief sections of East Berlin territory, passing through eastern stations (called , or ghost stations) without stopping. Both the eastern and western networks converged at , which became a major crossing point for those (mostly Westerners) with permission to cross.
Crossing
West Germans and citizens of other Western countries could generally visit East Germany, often after applying for a visa at an East German embassy several weeks in advance. Visas for day trips restricted to East Berlin were issued without previous application in a simplified procedure at the border crossing. However, East German authorities could refuse entry permits without stating a reason. In the 1980s, visitors from the western part of the city who wanted to visit the eastern part had to exchange at least DM 25 into East German currency at the poor exchange rate of 1:1. It was forbidden to export East German currency from the East, but money not spent could be left at the border for possible future visits. Tourists crossing from the west had to also pay for a visa, which cost DM 5; West Berliners did not have to pay this fee.
West Berliners initially could not visit East Berlin or East Germany at all—all crossing points were closed to them between 26 August 1961 and 17 December 1963. In 1963, negotiations between East and West resulted in a limited possibility for visits during the Christmas season that year (). Similar, very limited arrangements were made in 1964, 1965 and 1966.
In 1971, with the Four Power Agreement on Berlin, agreements were reached that allowed West Berliners to apply for visas to enter East Berlin and East Germany regularly, comparable to the regulations already in force for West Germans. However, East German authorities could still refuse entry permits.
East Berliners and East Germans could not, at first, travel to West Berlin or West Germany at all. This regulation remained in force essentially until the fall of the Wall, but over the years several exceptions to these rules were introduced, the most significant being:
Elderly pensioners could travel to the West starting in 1964
Visits of relatives for important family matters
People who had to travel to the West for professional reasons (for example, artists, truck drivers, musicians, writers, etc.)
For each of these exceptions, GDR citizens had to apply for individual approval, which was never guaranteed. In addition, even if travel was approved, GDR travellers could exchange only a very small number of East German Marks into Deutsche Marks (DM), thus limiting the financial resources available for them to travel to the West. This led to the West German practice of granting a small amount of DM annually (Begrüßungsgeld, or welcome money) to GDR citizens visiting West Germany and West Berlin to help alleviate this situation.
Citizens of other East European countries were in general subject to the same prohibition of visiting Western countries as East Germans, though the applicable exception (if any) varied from country to country.
Allied military personnel and civilian officials of the Allied forces could enter and exit East Berlin without submitting to East German passport controls, purchasing a visa or being required to exchange money. Likewise, Soviet military patrols could enter and exit West Berlin. This was a requirement of the post-war Four Powers Agreements. A particular area of concern for the Western Allies involved official dealings with East German authorities when crossing the border, since Allied policy did not recognize the authority of the GDR to regulate Allied military traffic to and from West Berlin, as well as the Allied presence within Greater Berlin, including entry into, exit from, and presence within East Berlin.
The Allies held that only the Soviet Union, and not the GDR, had the authority to regulate Allied personnel in such cases. For this reason, elaborate procedures were established to prevent inadvertent recognition of East German authority when engaged in travel through the GDR and when in East Berlin. Special rules applied to travel by Western Allied military personnel assigned to the military liaison missions accredited to the commander of Soviet forces in East Germany, located in Potsdam.
Allied personnel were restricted by policy when travelling by land to the following routes:
Transit between West Germany and West Berlin
Road: The Helmstedt–Berlin autobahn (A2) (checkpoints Alpha and Bravo respectively). Soviet military personnel manned these checkpoints and processed Allied personnel for travel between the two points.
Rail: Western Allied military personnel and civilian officials of the Allied forces were forbidden to use commercial train service between West Germany and West Berlin, because of GDR passport and customs controls when using them. Instead, the Allied forces operated a series of official (duty) trains that traveled between their respective duty stations in West Germany and West Berlin. When transiting the GDR, the trains would follow the route between Helmstedt and Griebnitzsee, just outside West Berlin. In addition to persons traveling on official business, authorized personnel could also use the duty trains for personal travel on a space-available basis. The trains traveled only at night, and as with transit by car, Soviet military personnel handled the processing of duty train travelers. (See History of the Berlin S-Bahn.)
Entry into and exit from East Berlin
Checkpoint Charlie (as a pedestrian or riding in a vehicle)
As with military personnel, special procedures applied to travel by diplomatic personnel of the Western Allies accredited to their respective embassies in the GDR. This was intended to prevent inadvertent recognition of East German authority when crossing between East and West Berlin, which could jeopardize the overall Allied position governing the freedom of movement by Allied forces personnel within all Berlin.
Ordinary citizens of the Western Allied powers, not formally affiliated with the Allied forces, were authorized to use all designated transit routes through East Germany to and from West Berlin. Regarding travel to East Berlin, such persons could also use the Friedrichstraße train station to enter and exit the city, in addition to Checkpoint Charlie. In these instances, such travelers, unlike Allied personnel, had to submit to East German border controls.
Defection attempts
During the years of the Wall, around 5,000 people successfully defected to West Berlin. The number of people who died trying to cross the Wall, or as a result of the Wall's existence, has been disputed. The most vocal claims by Alexandra Hildebrandt, director of the Checkpoint Charlie Museum and widow of the museum's founder, estimated the death toll to be well above 200. A historic research group at the Centre for Contemporary History (ZZF) in Potsdam has confirmed at least 140 deaths. Prior official figures listed 98 as being killed.
The East German government issued shooting orders (Schießbefehl) to border guards dealing with defectors, though such orders are not the same as "shoot to kill" orders. GDR officials denied issuing the latter. In an October 1973 order later discovered by researchers, guards were instructed that people attempting to cross the Wall were criminals and needed to be shot:
Early successful escapes involved people jumping the initial barbed wire or leaping out of apartment windows along the line, but these ended as the Wall was fortified. East German authorities no longer permitted apartments near the Wall to be occupied, and any building near the Wall had its windows boarded and later bricked up. On 15 August 1961, Conrad Schumann was the first East German border guard to escape by jumping the barbed wire to West Berlin.
On 22 August 1961, Ida Siekmann was the first casualty at the Berlin Wall: she died after she jumped out of her third floor apartment at 48 Bernauer Strasse. The first person to be shot and killed while trying to cross to West Berlin was Günter Litfin, a twenty-four-year-old tailor. He attempted to swim across the Spree to West Berlin on 24 August 1961, the same day that East German police had received shoot-to-kill orders to prevent anyone from escaping.
Another dramatic escape was carried out in April 1963 by Wolfgang Engels, a 19-year-old civilian employee of the Nationale Volksarmee (NVA). Engels stole a Soviet armored personnel carrier from a base where he was deployed and drove it right into the Wall. He was fired at and seriously wounded by border guards. But a West German policeman intervened, firing his weapon at the East German border guards. The policeman removed Engels from the vehicle, which had become entangled in the barbed wire.
East Germans successfully defected by a variety of methods: digging long tunnels under the Wall, waiting for favorable winds and taking a hot air balloon, sliding along aerial wires, flying ultralights and, in one instance, simply driving a sports car at full speed through the basic, initial fortifications. When a metal beam was placed at checkpoints to prevent this kind of defection, up to four people (two in the front seats and possibly two in the boot) drove under the bar in a sports car that had been modified to allow the roof and windscreen to come away when it made contact with the beam. They lay flat and kept driving forward. The East Germans then built zig-zagging roads at checkpoints. The sewer system predated the Wall, and some people escaped through the sewers, in a number of cases with assistance from the Unternehmen Reisebüro. In September 1962, 29 people escaped through a tunnel to the west. At least 70 tunnels were dug under the wall; only 19 were successful in allowing fugitives—about 400 persons—to escape. The East German authorities eventually used seismographic and acoustic equipment to detect the practice. In 1962, they planned an attempt to use explosives to destroy one tunnel, but this was not carried out as it was apparently sabotaged by a member of the Stasi.
An airborne escape was made by Thomas Krüger, who landed a Zlin Z 42M light aircraft of the Gesellschaft für Sport und Technik, an East German youth military training organization, at RAF Gatow. His aircraft, registration DDR-WOH, was dismantled and returned to the East Germans by road, complete with humorous slogans painted on it by airmen of the Royal Air Force, such as "Wish you were here" and "Come back soon".
If an escapee was wounded in a crossing attempt and lay on the death strip, no matter how close they were to the Western wall, Westerners could not intervene for fear of triggering engaging fire from the 'Grepos', the East Berlin border guards. The guards often let fugitives bleed to death in the middle of this ground, as in the most notorious failed attempt, that of Peter Fechter (aged 18) at a point near Zimmerstrasse in East Berlin. He was shot and bled to death, in full view of the Western media, on 17 August 1962. Fechter's death created negative publicity worldwide that led the leaders of East Berlin to place more restrictions on shooting in public places and provide medical care for possible "would-be escapers". The last person to be shot and killed while trying to cross the border was Chris Gueffroy on 6 February 1989, while the final person to die in an escape attempt was Winfried Freudenberg who was killed when his homemade natural gas-filled balloon crashed on 8 March 1989.
The Wall gave rise to a widespread sense of desperation and oppression in East Berlin, as expressed in the private thoughts of one resident, who confided to her diary "Our lives have lost their spirit... we can do nothing to stop them."
Concerts by Western artists and growing anti-Wall sentiment
David Bowie, 1987
On 6 June 1987, David Bowie, who earlier for several years lived and recorded in West Berlin, played a concert close to the Wall. This was attended by thousands of Eastern concertgoers across the Wall, followed by violent rioting in East Berlin. According to Tobias Ruther, these protests in East Berlin were the first in the sequence of riots that led to those of November 1989. Although other factors were probably more influential in the fall of the Wall, upon his death in 2016, the German Foreign Office tweeted "Good-bye, David Bowie. You are now among #Heroes. Thank you for helping to bring down the #wall."
Bruce Springsteen, 1988
On 19 July 1988, 16 months before the Wall came down, Bruce Springsteen and the E Street Band, played Rocking the Wall, a live concert in East Berlin, which was attended by 300,000 in person and broadcast on television. Springsteen spoke to the crowd in German, saying: "I'm not here for or against any government. I've come to play rock 'n' roll for you in the hope that one day all the barriers will be torn down". East Germany and its FDJ youth organization were worried they were losing an entire generation. They hoped that by letting Springsteen in, they could improve their sentiment among East Germans. However, this strategy of "one step backwards, two steps forwards" backfired, and the concert only made East Germans hungrier for more of the freedoms that Springsteen epitomized.
David Hasselhoff, 1989
On 31 December 1989, American TV actor and pop music singer David Hasselhoff was the headlining performer for the Freedom Tour Live concert, which was attended by over 500,000 people on both sides of the Wall. The live concert footage was directed by music video director Thomas Mignone and aired on broadcast television station Zweites Deutsches Fernsehen ZDF throughout Europe. During shooting, film crew personnel pulled people up from both sides to stand and celebrate on top of the wall. Hasselhoff sang his number one hit song "Looking for Freedom" on a platform at the end of a twenty-meter steel crane that swung above and over the Wall adjacent to the Brandenburg Gate. A small museum was created in 2008 to celebrate Hasselhoff in the basement of the Circus Hostel.
Comments by politicians
On 26 June 1963, 22 months after the erection of the Berlin Wall, U.S. President John F. Kennedy visited West Berlin. Speaking from a platform erected on the steps of Rathaus Schöneberg for an audience of 450,000 and straying from the prepared script, he declared in his Ich bin ein Berliner speech the support of the United States for West Germany and the people of West Berlin in particular:
The message was aimed as much at the Soviets as it was at Berliners and was a clear statement of U.S. policy in the wake of the construction of the Berlin Wall. The speech is considered one of Kennedy's best, both a significant moment in the Cold War and a high point of the New Frontier. It was a great morale boost for West Berliners, who lived in an exclave deep inside East Germany and feared a possible East German occupation.
British prime minister Margaret Thatcher commented in 1982:
In a speech at the Brandenburg Gate commemorating the 750th anniversary of Berlin on 12 June 1987, U.S. President Ronald Reagan challenged Mikhail Gorbachev, then the General Secretary of the Communist Party of the Soviet Union, to tear down the Wall as a symbol of increasing freedom in the Eastern Bloc:
In January 1989, GDR leader Erich Honecker predicted that the Wall would stand for 50 or 100 more years if the conditions that had caused its construction did not change.
Fall
Due to the increasing economic problems in the Eastern Bloc and the failure of the USSR to intervene in relation to the individual communist states, the brackets of the Eastern Bloc slowly began to loosen from the end of the 1980s. One example is the fall of the communist government in neighboring Poland's 1989 Polish parliamentary election. Also in June 1989, the Hungarian government began dismantling the electrified fence along its border with Austria (with Western TV crews present) although the border was still very closely guarded and escape was almost impossible.
The opening of a border gate between Austria and Hungary at the Pan-European Picnic on 19 August 1989, which was based on an idea by Otto von Habsburg to test the reaction of Mikhail Gorbachev, then triggered a peaceful chain reaction, at the end of which there was no longer the GDR and the Eastern Bloc had disintegrated. Because with the non-reaction of the USSR and the GDR to the mass exodus, the media-informed Eastern Europeans could feel the increasing loss of power of their governments and more and more East Germans were now trying to flee via Hungary. Erich Honecker explained to the Daily Mirror regarding the Pan-European Picnic and thus showed his people his own inaction: "Habsburg distributed leaflets far into Poland, on which the East German holidaymakers were invited to a picnic. When they came to the picnic, they were given gifts, food and Deutsche Mark, and then they were persuaded to come to the West." Then, in September, more than 13,000 East German tourists escaped through Hungary to Austria. This set up a chain of events. The Hungarians prevented many more East Germans from crossing the border and returned them to Budapest. These East Germans flooded the West German embassy and refused to return to East Germany.
The East German government responded by disallowing any further travel to Hungary but allowed those already there to return to East Germany. This triggered similar events in neighboring Czechoslovakia. This time, however, the East German authorities allowed people to leave, provided that they did so by train through East Germany. This was followed by mass demonstrations within East Germany itself. Protest demonstrations spread throughout East Germany in September 1989. Initially, protesters were mostly people wanting to leave to the West, chanting ("We want out!"). Then protestors began to chant ("We are staying here!"). This was the start of what East Germans generally call the "Peaceful Revolution" of late 1989. The protest demonstrations grew considerably by early November. The movement neared its height on 4 November, when half a million people gathered to demand political change, at the Alexanderplatz demonstration, East Berlin's large public square and transportation hub. On 9 October 1989, the police and army units were given permission to use force against those assembled, but this did not deter the church service and march from taking place, which gathered 70,000 people.
The longtime leader of East Germany, Erich Honecker, resigned on 18 October 1989 and was replaced by Egon Krenz that day.
The wave of refugees leaving East Germany for the West kept increasing. By early November refugees were finding their way to Hungary via Czechoslovakia, or via the West German Embassy in Prague. This was tolerated by the new Krenz government, because of long-standing agreements with the communist Czechoslovak government, allowing free travel across their common border. However, this movement of people grew so large it caused difficulties for both countries. To ease the difficulties, the politburo led by Krenz decided on 9 November to allow refugees to exit directly through crossing points between East Germany and West Germany, including between East and West Berlin. Later the same day, the ministerial administration modified the proposal to include private, round-trip, and travel. The new regulations were to take effect the next day.
Günter Schabowski, the party boss in East Berlin and the spokesman for the SED Politburo, had the task of announcing the new regulations. However, he had not been involved in the discussions about the new regulations and had not been fully updated. Shortly before a press conference on 9 November, he was handed a note announcing the changes, but given no further instructions on how to handle the information. These regulations had only been completed a few hours earlier and were to take effect the following day, so as to allow time to inform the border guards. But this starting time delay was not communicated to Schabowski. At the end of the press conference, Schabowski read out loud the note he had been given. A reporter, ANSA's Riccardo Ehrman, asked when the regulations would take effect. After a few seconds' hesitation, Schabowski replied, "As far as I know, it takes effect immediately, without delay". After further questions from journalists, he confirmed that the regulations included the border crossings through the Wall into West Berlin, which he had not mentioned until then. He repeated that it was immediate in an interview with American journalist Tom Brokaw.
Excerpts from Schabowski's press conference were the lead story on West Germany's two main news programs that night—at 7:17 p.m. on ZDF's heute and at 8 p.m. on ARD's Tagesschau. As ARD and ZDF had broadcast to nearly all of East Germany since the late 1950s and had become accepted by the East German authorities, the news was broadcast there as well simultaneously. Later that night, on ARD's Tagesthemen, anchorman Hanns Joachim Friedrichs proclaimed, "This 9 November is a historic day. The GDR has announced that, starting immediately, its borders are open to everyone. The gates in the Wall stand open wide."
After hearing the broadcast, East Germans began gathering at the Wall, at the six checkpoints between East and West Berlin, demanding that border guards immediately open the gates. The surprised and overwhelmed guards made many hectic telephone calls to their superiors about the problem. At first, they were ordered to find the "more aggressive" people gathered at the gates and stamp their passports with a special stamp that barred them from returning to East Germany—in effect, revoking their citizenship. However, this still left thousands of people demanding to be let through "as Schabowski said we can". It soon became clear that no one among the East German authorities would take personal responsibility for issuing orders to use lethal force, so the vastly outnumbered soldiers had no way to hold back the huge crowd of East German citizens. Finally, at 10:45 p.m. on 9 November, Harald Jäger, the commander of the Bornholmer Straße border crossing yielded, allowing the guards to open the checkpoints and allowing people through with little or no identity checking. As the Ossis swarmed through, they were greeted by Wessis waiting with flowers and champagne amid wild rejoicing. Soon afterward, a crowd of West Berliners jumped on top of the Wall, and were soon joined by East German youngsters. The evening of 9 November 1989 is known as the night the Wall came down.
Another border crossing to the south may have been opened earlier. An account by Heinz Schäfer indicates that he also acted independently and ordered the opening of the gate at Waltersdorf-Rudow a couple of hours earlier. This may explain reports of East Berliners appearing in West Berlin earlier than the opening of the Bornholmer Straße border crossing.
Thirty years after the fall of the Berlin Wall, The Guardian collected short stories from 9 November 1989 by five German writers who reflect on the day. In this, Kathrin Schmidt remembers comically: "I downed almost an entire bottle of schnapps".
Legacy
Little is left of the Wall at its original site, which was destroyed almost in its entirety. Three long sections are still standing: an piece of the first (westernmost) wall at the Topography of Terror, site of the former Gestapo headquarters, halfway between Checkpoint Charlie and Potsdamer Platz; a longer section of the second (easternmost) wall along the Spree River near the , nicknamed East Side Gallery; and a third section that is partly reconstructed, in the north at Bernauer Straße, which was turned into a memorial in 1998. Other isolated fragments, lampposts, other elements, and a few watchtowers also remain in various parts of the city.
The former leadership in the Schlesischen Busch in the vicinity of the Puschkinallee—the listed, twelve-meter high watchtower stands in a piece of the wall strip, which has been turned into a park, near the Lohmühleninsel.
The former "Kieler Eck" (Kiel Corner) on Kieler Strasse in Mitte, close to the Berlin-Spandau Schifffahrtskanal—the tower is protected as a historic monument and now surrounded on three sides by new buildings. It houses a memorial site named after the Wallopfer Günter Litfin, who was shot at Humboldthafen in August 1961. The memorial site, which is run by the initiative of his brother Jürgen Liftin, can be viewed after registration.
The former management office at Nieder Neuendorf, in the district of Hennigsdorf of the same name—here is the permanent exhibition on the history of the border installations between the two German states.
The former management station at Bergfelde, today the district of Hohen Neuendorf—The tower is located in an already reforested area of the border strip and is used together with surrounding terrain as a nature protection tower by the Deutschen Waldjugend.
The only one of the much slimmer observation towers (BT-11) in the Erna-Berger-Strasse also in Mitte—however, was moved by a few meters for construction work and is no longer in the original location; There is an exhibition about the wall in the area of the Potsdamer Platz in planning.
Nothing still accurately represents the Wall's original appearance better than a very short stretch at Bernauer Straße associated with the Berlin Wall Documentation Center. Other remnants are badly damaged by souvenir seekers. Fragments of the Wall were taken, and some were sold around the world. Appearing both with and without certificates of authenticity, these fragments are now a staple on the online auction service eBay as well as German souvenir shops. Today, the eastern side is covered in graffiti that did not exist while the Wall was guarded by the armed soldiers of East Germany. Previously, graffiti appeared only on the western side. Along some tourist areas of the city centre, the city government has marked the location of the former Wall by a row of cobblestones in the street. In most places only the "first" wall is marked, except near Potsdamer Platz where the stretch of both walls is marked, giving visitors an impression of the dimension of the barrier system.
After the fall of the Berlin Wall, there were initiatives that they want to preserve the death strip walkways and redevelop them into a hiking and cycling area, known as . It is part of the initiative by the Berlin Senate since 11 October 2001.
Cultural differences
For many years after reunification, people in Germany talked about cultural differences between East and West Germans (colloquially Ossis and Wessis), sometimes described as Mauer im Kopf (The wall in the head). A September 2004 poll found that 25 percent of West Germans and 12 percent of East Germans wished that East and West should be separated again by a "Wall". A poll taken in October 2009 on the occasion of the 20th anniversary of the fall of the Wall indicated, however, that only about a tenth of the population was still unhappy with the unification (8 percent in the East; 12 percent in the West). Although differences are still perceived between East and West, Germans make similar distinctions between North and South.
A 2009 poll conducted by Russia's VTsIOM, found that more than half of all Russians do not know who built the Berlin Wall. Ten percent of people surveyed thought Berlin residents built it themselves. Six percent said Western powers built it and four percent thought it was a "bilateral initiative" of the Soviet Union and the West. Fifty-eight percent said they did not know who built it, with just 24 percent correctly naming the Soviet Union and its then-communist ally East Germany.
Wall segments around the world
Not all segments of the Wall were ground up as the Wall was being torn down. Many segments have been given to various institutions around the world. They can be found, for instance, in presidential and historical museums, lobbies of hotels and corporations, at universities and government buildings, and in public spaces in different countries of the world.
50th anniversary commemoration
On 13 August 2011, Germany marked the 50th anniversary of East Germany beginning the erection of the Berlin Wall. Chancellor Angela Merkel joined with President Christian Wulff and Berlin Mayor Klaus Wowereit at the Bernauer Straße memorial park to remember lives and liberty. Speeches extolled freedom and a minute of silence at noon honored those who died trying to flee to the West. "It is our shared responsibility to keep the memory alive and to pass it on to the coming generations as a reminder to stand up for freedom and democracy to ensure that such injustice may never happen again." entreated Mayor Wowereit. "It has been shown once again: Freedom is invincible at the end. No wall can permanently withstand the desire for freedom", proclaimed President Wulff.
Polling
A small minority still support the wall or even support rebuilding the wall back up. In 2008 a poll found that 11% of participants from the former West Berlin and 12% form the former East Berlin said it would be better if the wall was still in place.
A November 2009 poll found that 12% of Germans said the wall should be rebuilt. The poll also found that in the former West German states support was at 12% and in the former East German states it was 13%. A September 2009 poll found 15% of Germans supported a wall, while in the west it was 16% and in the east it was at 10%.
A 2010 poll from Emnid for Bild, found that 24% of West Germans and 23% of East Germans wished for the wall still being in place.
A 2019 poll from Berliner Zeitung on the 30th anniversary, found that 8% of Berliners supported the idea if the wall was still standing, The overwhelming majority of Berliners at 87% however supported the fall of the wall. The poll also found that 28% of the Alternative for Germany (AfD) and 16% of Free Democratic Party (FDP) supporters supported bringing back the wall. A 2019 Yougov poll found that 13% of Germans wanted the wall back, in the West support was at 14% and in the East it was 13%.
A 2019 poll from Forsa found 35% of Berliners thought the construction of the Wall was not so wrong with supporters of the Left Party at 74%.
Related media
Documentaries
Documentary films specifically about the Berlin Wall include:
The Tunnel (December 1962), an NBC News Special documentary film.
The Road to the Wall (1962), a documentary film.
Something to Do with the Wall (1991), a documentary about the fall of the Berlin Wall by Ross McElwee and Marilyn Levine, originally conceived as a commemoration of the 25th anniversary of its construction.
Rabbit à la Berlin (2009), a documentary film, directed by Bartek Konopka, told from the point of view of a group of wild rabbits that inhabited the zone between the two walls.
The American Sector (2020), a documentary by Courtney Stephens and Pacho Velez that tracks down the wall segments located in the U.S.
Feature films
Fictional films featuring the Berlin Wall have included:
Escape from East Berlin (1962), American-West German film inspired by story of 29 East Germans that tunneled under the wall
The Spy Who Came in from the Cold (1965), a Cold War classic set on both sides of The Wall, from the eponymous book by John le Carré, directed by Martin Ritt.
The Boy and the Ball and the Hole in the Wall (1965), Spanish-Mexican co-production.
Funeral in Berlin (1966), a spy movie starring Michael Caine, directed by Guy Hamilton.
Casino Royale (1967), a film featuring a segment centred on a house apparently bisected by the Wall.
The Wicked Dreams of Paula Schultz (1968), a Cold War spy farce about an Olympic athlete who defects, directed by George Marshall.
Berlin Tunnel 21 (1981), a made-for-TV movie about a former American officer leading an attempt to build a tunnel underneath The Wall as a rescue route.
Night Crossing (1982), a British-American drama film starring John Hurt, Jane Alexander, and Beau Bridges, based on the true story of the Strelzyk and Wetzel families, who on 16 September 1979, attempted to escape from East Germany to West Germany in a homemade hot air balloon, during the days of the Inner German border-era.
The Innocent (1993), a film about the joint CIA/MI6 operation to build a tunnel under East Berlin in the 1950s, directed by John Schlesinger.
Sonnenallee (1999), a German comedy film about life in East Berlin in the late 1970s, directed by Leander Haußmann.
The Tunnel (2001), a dramatization of a collaborative tunnel under the Wall, filmed by Roland Suso Richter.
Good Bye Lenin! (2003), film set during German unification that depicts the fall of the Wall through archive footage
Open The Wall (2014), featuring a dramatized story of the East-German border guard who was the first to let East Berliners cross the border to West Berlin on 9 November 1989.
Bridge of Spies (2015), featuring a dramatized subplot about Frederic Pryor, in which an American economics graduate student visits his German girlfriend in East Berlin just as the Berlin Wall is being built. He tries to bring her back into West Berlin but is stopped by Stasi agents and arrested as a spy.
Literature
Some novels specifically about the Berlin Wall include:
John le Carré, The Spy Who Came in from the Cold (1963), classic Cold War spy fiction.
Len Deighton, Berlin Game (1983), classic Cold War spy fiction
T.H.E. Hill, The Day Before the Berlin Wall: Could We Have Stopped It? – An Alternate History of Cold War Espionage, 2010 – based on a legend told in Berlin in the 1970s.
John Marks' The Wall (1999) in which an American spy defects to the East just hours before the Wall falls.
Marcia Preston's West of the Wall (2007, published as Trudy's Promise in North America), in which the heroine, left behind in East Berlin, waits for news of her husband after he makes his escape over the Berlin Wall.
Peter Schneider's The Wall Jumper, (1984; German: Der Mauerspringer, 1982), the Wall plays a central role in this novel set in Berlin of the 1980s.
Music
Music related to the Berlin Wall includes:
Stationary Traveller (1984), a concept album by Camel that takes the theme of families and friends split up by the building of the Berlin Wall.
"West of the Wall", a 1962 top 40 hit by Toni Fisher, which tells the tale of two lovers separated by the newly built Berlin Wall.
"Holidays in the Sun", a song by the English punk rock band Sex Pistols which prominently mentions the Wall, specifically singer Johnny Rotten's fantasy of digging a tunnel under it.
David Bowie's "Heroes" (1977), inspired by the image of a couple kissing at the Berlin Wall (in reality, the couple was his producer Tony Visconti and backup singer Antonia Maaß). The song (which, along with the album of the same name, was recorded in Berlin), makes lyrical references to the kissing couple, and to the "Wall of Shame" ("the shame was on the other side"). Upon Bowie's death, the Federal Foreign Office paid homage to Bowie on Twitter:see also above
"" (1984), a song by the Dutch pop band , about the differences between East and West Berlin during the period of the Berlin Wall.
"Chippin' Away" (1990), a song by Tom Fedora, performed by Crosby, Stills & Nash on the Berlin Wall, which appeared on Graham Nash's solo album Innocent Eyes (1986).
"Berliners", a song by Roy Harper from his 1990 album Once (lyrics include "They built a wall, boys, it stayed up for thirty years"). The song uses a BBC news broadcast describing the fall of the wall.
"Hedwig and the Angry Inch," a rock opera whose genderqueer protagonist Hedwig Robinson was born in East Berlin and later, living in the United States, describes herself as "the new Berlin Wall" standing between "East and West, slavery and freedom, man and woman, top and bottom." As a result, she says, people are moved to "decorate" her with "blood, graffiti and spit." (1998)
The music video for Liza Fox's song "Free" (2013) contains video clips of the fall of the Berlin Wall.
Visual art
Artworks related to the Berlin Wall include:
In 1982, the West-German artist created about 500 artworks along the former border strip around West Berlin as part of his work series Border Injuries. On one of his actions he tore down a large part of the Wall, installed a prepared foil of 3x2m in it, and finished the painting there before the border soldiers on patrol could detect him. This performance was recorded on video. His actions are well-documented both in newspapers from that time and in recent scientific publications.
The Day the Wall Came Down, 1996 and 1998 sculptures by Veryl Goodnight, which depict five horses leaping over actual pieces of the Berlin Wall.
Games
Video games related to the Berlin Wall include:
The Berlin Wall (1991), a video game.
Ostalgie: The Berlin Wall (2018), video game by Kremlingames, where the player, playing as the leader of the GDR from 1989 to 1991, can take down the Berlin Wall themselves or as a result of events in the game, or keep the wall intact as long as the country exists.
See also
Berlin Crisis of 1961 (October 1961)
Chapel of Reconciliation
Deborah Kennedy, American artist whose works were featured on the wall before its fall
Dissolution of the Soviet Union (1991)
East Germany balloon escape
Green Line (Lebanon)
Inner German border
Israeli annexation of East Jerusalem
Korean Demilitarized Zone
Military Demarcation Line
List of walls
Operation Gold
Peace lines
Removal of Hungary's border fence with Austria
The Wall – Live in Berlin (rock opera/concert, 21 July 1990)
World Freedom Day (United States)
Notes
References
Sources
Childs, David (2001). The Fall of the GDR: Germany's Road To Unity, Longman, Pearsoned.co.uk.
Childs, David (1986) [1983]. The GDR: Moscow's German Ally, London: George Allen & Unwin, .
Childs, David (2001). The Fall of the GDR, Longman. Amazon.co.uk
Childs, David (2000). The Two Red Flags: European Social Democracy & Soviet Communism Since 1945, Routledge.
Childs, David (1991). Germany in the Twentieth Century, (From pre-1918 to the restoration of German unity), Batsford, Third edition.
Childs, David (1987). East Germany to the 1990s Can It Resist Glasnost?, The Economist Intelligence Unit. . WorldCat.org
Luftbildatlas. Entlang der Berliner Mauer. Karten, Pläne und Fotos. Hans Wolfgang Hoffmann / Philipp Meuser (eds.) Berlin 2009.
Sarotte, Mary Elise (2014). Collapse: The Accidental Opening of the Berlin Wall, New York: Basic Books,
Sarotte, Mary Elise (2014) [1989]. The Struggle to Create Post-Cold War Europe (Second Edition) Princeton: Princeton University Press,
External links
Berlin Wall on OpenStreetMap (zoomable and scrollable)
Other resources:
Berlin Wall image group on Flickr
Berlin Wall Online, historical chronicle
Border barriers
1961 establishments in East Germany
1961 establishments in West Germany
1961 in military history
1961 in politics
20th century in Berlin
Allied occupation of Germany
Articles containing video clips
Buildings and structures completed in 1961
Buildings and structures demolished in 1989
Buildings and structures demolished in 1990
Demolished buildings and structures in Germany
Eastern Bloc
Former buildings and structures in Germany
Inner German border
Separation barriers
City walls in Germany | Berlin Wall | Engineering | 14,390 |
3,982,609 | https://en.wikipedia.org/wiki/Shoulder%20surfing%20%28computer%20security%29 | In computer security, shoulder surfing is a type of social engineering technique used to obtain information such as personal identification numbers (PINs), passwords and other confidential data by looking over the victim's shoulder. Unauthorized users watch the keystrokes inputted on a device or listen to sensitive information being spoken, which is also known as eavesdropping.
Methods and history
This attack can be performed either at close range (by directly looking over the victim's shoulder) or from a longer range with, for example, a pair of binoculars or similar hardware. Attackers do not need any technical skills in order to perform this method, and keen observation of victims' surroundings and the typing pattern is sufficient. In the early 1980s, shoulder surfing was practiced near public pay phones to steal calling card digits and make long-distance calls or sell them in the market for cheaper prices than the original purchaser paid. However, the advent of modern-day technologies like hidden cameras and secret microphones makes shoulder surfing easier and gives the attacker more scope to perform long-range shoulder surfing. A hidden camera allows the attacker to capture the whole login process and other confidential data of the victim, which ultimately could lead to financial loss or identity theft. Shoulder surfing is more likely to occur in crowded places because it is easier to observe the information without getting the victim's attention.
There are two types of shoulder-surfing attack: direct observation attacks, in which authentication information is obtained by a person who is directly monitoring the authentication sequence, and recording attacks, in which the authentication information is obtained by recording the authentication sequence for later analysis to open the device. Apart from threats to password or PIN entry, shoulder surfing also occurs in daily situations to uncover private content on handheld mobile devices; shoulder surfing visual content was found to leak sensitive information of the user and even private information about third parties.
Countermeasures
Gaze-based password entry
The basic procedure for gaze-based password entry is similar to normal password entry, except that in place of typing a key or touching the screen, the user looks at each desired character or trigger region in sequence (same as eye typing). The approach can, therefore, be used both with character-based passwords by using an on-screen keyboard and with graphical password schemes as surveyed in. A variety of considerations is important for ensuring usability and security. Eye-tracking technology has progressed significantly since its origins in the early 1900s. State of the art eye trackers offers non-encumbering, remote video-based eye tracking with an accuracy of 1˚ of visual angle. Eye trackers are a specialized application of computer vision. A camera is used to monitor the user's eyes. One or more infrared light sources illuminate the user's face and produce a glint – a reflection of the light source on the cornea. As the user looks in different directions the pupil moves but the location of the glint on the cornea remains fixed. The relative motion and position of the center of the pupil and the glint are used to estimate the gaze vector, which is then mapped to coordinates on the screen plane.
Researchers proposed ways to counter shoulder surfing on mobile devices by leveraging the front-facing camera for gaze-based password entry. For example, GazeTouchPIN and GazeTouchPass combine gaze input in the form of eye movements to the left/right, and touch input by tapping on-screen buttons. These methods are more secure than traditional touch-based input (e.g., PIN and Lock Patterns) because they require shoulder surfers to (1) observe the user's eyes, (2) observe the user's touch input, and (3) combine the observations.
Painting album mechanism
Painting album mechanism is an anti-shoulder surfing mechanism, which has characteristics of both recall and recognition graphical techniques. Rather than using a regular PIN or password involving alphanumeric characters, users select a sequence of colors or pictures to unlock the system. The order of the colors and pictures selected during the sign-in process has to match with the order at registration. This anti-shoulder surfing security method was developed based on survey results of users' affinity of choices, and through observation on the way children paint pictures. The resulting mechanism was developed from the survey of user choices, and the outcome created three input schemes named Swipe Scheme, Colour Scheme, and Scot Scheme. Swipe Scheme is implemented in Microsoft Windows 8, and in later versions, it is known as Picture Password; however it has drawn criticism for requiring the user to use a secure enough gesture.
Secret tap method
For access to sensitive information with a low risk of shoulder surfing, the secret tap method is a technique that does not expose the authentication information during entry, even if other individuals try to view the input process. Additionally, the risk of camera recordings also poses a threat. Therefore, it is necessary to make the authentication process more complex in order to prevent authentication information from being stolen. For example, smartphones use biometrics such as fingerprint scanning or facial recognition which cannot be replicated by a shoulder surfer.
The secret tap authentication method can use icons or some other form of system. The goals of a secret tap system are:
Covert observation resistance: Maintain the resistance strength at a level that prevents the authentication information from being revealed to other individuals, even if the authentication operation is performed numerous times.
Recording attack resistance: Maintain the resistance strength at a level that prevents the authentication information from being analyzed by other individuals even if the authentication operation is fully recorded.
Brute-force attack resistance: Maintain the resistance strength at a level that prevents the authentication process from being broken more easily than by a brute-force attack on a four-digit PIN. This policy follows the standard put forth in ISO 9564-1.
Usability: Maintain a level of usability that permits operators to perform the authentication operation with ease.
Comparison of risks between alphanumeric and graphical passwords
The primary benefit of graphical passwords compared to alphanumeric passwords is improved memorability. However, the potential detriment of this advantage is the increased risk of shoulder-surfing. Graphical passwords that use graphics or pictures such as PassFaces, Jiminy, VIP, Passpoints or a combination of graphics and audio such as AVAP are likely all subject to this increased risk unless somehow mitigated in implementation. The results indicate the fact that both alphanumeric and graphical password-based authentication mechanisms may have a significant vulnerability to shoulder-surfing unless certain precautions are taken. Despite the common belief that nondictionary passwords are the most secure type of password-based authentication, the results demonstrate that it is, in fact, the most vulnerable configuration to shoulder-surfing.
PIN entry
Personal identification number (or PIN for short) is used to authenticate oneself in various situations, while withdrawing or depositing money from an automatic teller machine, unlocking a phone, a door, a laptop or a PDA. Though this method of authentication is a two step verification process in some situations, it is vulnerable to shoulder surfing attacks. An attacker can obtain the PIN either by directly looking over the victim's shoulder or by recording the whole login process. On items such as mobile phones with glass, glossy screens, the user could leave smudges on the screen, revealing a PIN. Some highly advanced attacks use thermal cameras to see the thermal signature of the PIN entered. Thermal attacks take advantage of heat fingerprints remaining on keys after the authenticating person is done entering the secret. So, various shoulder surfing resistant PIN entry methodologies are used to make the authentication process secure. Examples include PIN pads with built-in privacy shields. Another example used in ATMs and some entry systems is that of the use of metal PIN pads, making thermal camera attacks nearly impossible due to their material, shielding, reflectivity or internal heating. The transfer of heat through wiping with warm objects or hands is found effective to counter thermal attacks in experiments.
Countermeasure testing
The cognitive trapdoor game has three groups involved in it: a machine verifier, a human prover, and a human observer. The goal of each group is that a human prover has to input the PIN by answering the questions posed by the machine verifier while an observer attempts to shoulder surf the PIN. As the countermeasures are by design harder to easily usurp, it is not easy for the observer to remember the whole login process unless the observer has a recording device.
Virtual reality
A user could wear a virtual reality headset to mitigate the issues of shoulder surfing; however, gesture controls, buttons pressed, and voice commands could still be attacked.
See also
Credit card fraud
Information diving
Phishing
Social engineering (security)
References
Hacking (computer security)
Hacker culture
Computing terminology | Shoulder surfing (computer security) | Technology | 1,781 |
30,307,851 | https://en.wikipedia.org/wiki/Distortion%20problem | In functional analysis, a branch of mathematics, the distortion problem is to determine by how much one can distort the unit sphere in a given Banach space using an equivalent norm. Specifically, a Banach space X is called λ-distortable if there exists an equivalent norm |x| on X such that, for all infinite-dimensional subspaces Y in X,
(see distortion (mathematics)). Note that every Banach space is trivially 1-distortable. A Banach space is called distortable if it is λ-distortable for some λ > 1 and it is called arbitrarily distortable if it is λ-distortable for any λ. Distortability first emerged as an important property of Banach spaces in the 1960s, where it was studied by and .
James proved that c0 and ℓ1 are not distortable. Milman showed that if X is a Banach space that does not contain an isomorphic copy of c0 or ℓp for some (see sequence space), then some infinite-dimensional subspace of X is distortable. So the distortion problem is now primarily of interest on the spaces ℓp, all of which are separable and uniform convex, for .
In separable and uniform convex spaces, distortability is easily seen to be equivalent to the ostensibly more general question of whether or not every real-valued Lipschitz function ƒ defined on the sphere in X stabilizes on the sphere of an infinite dimensional subspace, i.e., whether there is a real number a ∈ R so that for every δ > 0 there is an infinite dimensional subspace Y of X, so that |a − ƒ(y)| < δ, for all y ∈ Y, with ||y|| = 1. But it follows from the result of that on ℓ1 there are Lipschitz functions which do not stabilize, although this space is not distortable by . In a separable Hilbert space, the distortion problem is equivalent to the question of whether there exist subsets of the unit sphere separated by a positive distance and yet intersect every infinite-dimensional closed subspace. Unlike many properties of Banach spaces, the distortion problem seems to be as difficult on Hilbert spaces as on other Banach spaces. On a separable Hilbert space, and for the other ℓp-spaces, 1 < p < ∞, the distortion problem was solved affirmatively by , who showed that ℓ2 is arbitrarily distortable, using the first known arbitrarily distortable space constructed by
.
See also
Tsirelson space
Banach space
References
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Functional analysis | Distortion problem | Mathematics | 552 |
3,727,811 | https://en.wikipedia.org/wiki/NGC%202683 | NGC 2683 is a field spiral galaxy in the northern constellation of Lynx. It was nicknamed the "UFO Galaxy" by the Astronaut Memorial Planetarium and Observatory. It was discovered by the astronomer William Herschel on February 5, 1788.
It is viewed nearly edge-on from Earth's location in space and is located about 30 million light-years away, although previous estimates also give distances between 16 and 25 million light-years.
NGC 2683 is receding from Earth at , and from the Galactic Center at .
Visibility
The reddened light from the center of the galaxy appears yellowish due to the intervening gas and dust located within the outer arms of NGC 2683. Its apparent magnitude is 10.6 making it not visible to the human eye without the aid of a small telescope.
Characteristics
While usually considered an unbarred spiral galaxy, recent research suggests it may in fact be a barred spiral galaxy; its bar is hard to see due to its high inclination.
Further support for the presence of a bar stems from the X-shaped structure seen near its centre, which is thought to be associated with a buckling instability of a stellar bar.
It is also both smaller and less luminous than the Milky Way with very little neutral hydrogen or molecular hydrogen and a low luminosity in the infrared, which suggests a currently low rate of star formation.
NGC 2683 is rich in globular clusters, hosting about 300 of them, twice the number found in the Milky Way. Due to its vast distance and complexity (due to the association of globular clusters bound to it), NGC 2638's mass has not been calculated as accurately as it could be. Otherwise its volume and vector motions are reasonably well known and characterized.
Several satellite galaxies are known in the vicinity of NGC 2683. The largest is KK 69, with a Holmberg diameter of 12,000 light-years (3.7 kiloparsecs). It is a dwarf transitional galaxy, with properties intermediate between those of dwarf irregular galaxies and dwarf spheroidal galaxies. Another is KK 70, which is about half the diameter of KK 69. Two additional dwarf galaxies are assumed to be satellites: they are N2683dw1 and N2683dw2, which are dwarf irregular and dwarf spheroidal galaxies, respectively.
References
External links
APOD, 5 Feb 2014
Unbarred spiral galaxies
Field galaxies
Lynx (constellation)
2683
04641
24930 | NGC 2683 | Astronomy | 500 |
51,406,533 | https://en.wikipedia.org/wiki/Racah%20seniority%20number | The Racah seniority number (seniority quantum number) was introduced by Giulio Racah for the classification of electrons in an atomic configuration. The "seniority number", in a loosing statement, is quantum number additional to the total angular momentum and total spin , which gives the degree of unpaired particles.
A spin-independent interaction is assumed with the property
,
where is the combined angular momentum, magnetic quantum number, is electrons' orbital angular momenta, and is the dimensionless magnetic moment. The equation above shows there is no interaction unless the two electrons' orbital angular momenta are coupled to . The eigenvalue is the "seniority number" .
References
Quantum mechanics | Racah seniority number | Physics | 144 |
16,108,852 | https://en.wikipedia.org/wiki/Immersion%20silver%20plating | Immersion silver plating (or IAg plating) is a surface plating process that creates a thin layer of silver over copper objects. It consists in dipping the object briefly into a solution containing silver ions.
Immersion silver plating is used by the electronics industry in manufacture of printed circuit boards (PCBs), to protect copper conductors from oxidation and improve solderability.
Advantages and disadvantages
Immersion silver coatings have excellent surface planarity, compared to more traditional coating processes such as hot air solder leveling (HASL). They also have low losses in high-frequency applications due to the skin effect.
On the other hand, silver coatings will degrade over time due to oxidation or air contaminants such as sulfur compounds and chlorine. A problem peculiar to silver coatings is the formation of silver whiskers under electric fields, which may short out components.
Specifications
IPC Standard: IPC-4553
See also
Electroless nickel immersion gold (ENIG)
Hot air solder leveling (HASL)
Organic solderability preservative (OSP)
Reflow soldering
Wave soldering
References
External links
PCB Assembly & PCBA Manufacturing
Bluetooth PCBA Manufacturing
Printed circuit board manufacturing | Immersion silver plating | Engineering | 252 |
393,810 | https://en.wikipedia.org/wiki/Richardson%20number | The Richardson number (Ri) is named after Lewis Fry Richardson (1881–1953). It is the dimensionless number that expresses the ratio of the buoyancy term to the flow shear term:
where is gravity, is density, is a representative flow speed, and is depth.
The Richardson number, or one of several variants, is of practical importance in weather forecasting and in investigating density and turbidity currents in oceans, lakes, and reservoirs.
When considering flows in which density differences are small (the
Boussinesq approximation), it is common to use the reduced gravity
g' and the relevant parameter is the densimetric Richardson number
which is used frequently when considering atmospheric or oceanic flows.
If the Richardson number is much less than unity, buoyancy is unimportant
in the flow. If it is much greater than unity, buoyancy is dominant (in
the sense that there is insufficient kinetic energy to homogenize the fluids).
If the Richardson number is of order unity, then the flow is likely to
be buoyancy-driven: the energy of the flow derives from the potential energy in the system originally.
Aviation
In aviation, the Richardson number is used as a rough measure of expected air turbulence. A lower value indicates a higher degree of turbulence. Values in the range 10 to 0.1 are typical, with values below unity indicating significant turbulence.
Thermal convection
In thermal convection problems, Richardson number represents the importance of natural convection relative to the forced convection. The Richardson number in this context is defined as
where g is the gravitational acceleration, is the thermal expansion coefficient, Thot is the hot wall temperature, Tref is the reference temperature, L is the characteristic length, and V is the characteristic velocity.
The Richardson number can also be expressed by using a combination of the Grashof number and Reynolds number,
Typically, the natural convection is negligible when Ri < 0.1, forced convection is negligible when Ri > 10, and neither is negligible when 0.1 < Ri < 10. It may be noted that usually the forced convection is large relative to natural convection except in the case of extremely low forced flow velocities. However, buoyancy often plays a significant role in defining the laminar–turbulent transition of a mixed convection flow. In the design of water filled thermal energy storage tanks, the Richardson number can be useful.
Meteorology
In atmospheric science, several different expressions for the Richardson number are commonly used: the flux Richardson number (which is fundamental), the gradient Richardson number, and the bulk Richardson number.
The flux Richardson number is the ratio of buoyant production (or suppression) of turbulence kinetic energy to the production of turbulence by shear. Mathematically, this is:
,
where is the virtual temperature, is the virtual potential temperature, is the altitude, is the component of the wind, is the component of the wind, and is the (vertical) component of the wind. A prime (e.g. ) denotes a deviation of the respective field from its Reynolds average.
The gradient Richardson number is arrived at by approximating the flux Richardson number using "K-theory". This results in:
.
The bulk Richardson number results from making a finite difference approximation to the derivatives in the expression for the gradient Richardson number, giving:
.
Here, for any variable , , i.e. the difference between at altitude and altitude . If the lower reference level is taken to be , then (due to the no-slip boundary condition), so the expression simplifies to:
.
Oceanography
In oceanography, the Richardson number has a more general form which takes stratification into account. It is a measure of relative importance of mechanical and density effects in the water column, as described by the Taylor–Goldstein equation, used to model Kelvin–Helmholtz instability which is driven by sheared flows.
where N is the Brunt–Väisälä frequency and u the wind speed.
The Richardson number defined above is always considered positive. A negative value of N² (i.e. complex N) indicates unstable density gradients with active convective overturning. Under such circumstances the magnitude of negative Ri is not generally of interest. It can be shown that Ri < 1/4 is a necessary condition for velocity shear to overcome the tendency of a stratified fluid to remain stratified, and some mixing (turbulence) will generally occur. When Ri is large, turbulent mixing across the stratification is generally suppressed.
References
Atmospheric dispersion modeling
Fluid dynamics
Buoyancy
Dimensionless numbers of fluid mechanics | Richardson number | Chemistry,Engineering,Environmental_science | 935 |
15,668,437 | https://en.wikipedia.org/wiki/Gartons%20Limited | Dr John Garton, of the firm of Garton Brothers of Newton-le-Willows in the United Kingdom was the Originator of Scientific Farm Plant Breeding. He is credited as the first scientist to show that the common grain crops and many other plants are self-fertilizing. He also invented the process of multiple cross-fertilization of crop plants.
In 1898 the business became known as Gartons Limited and, under the inspired commercial leadership of George Peddie Miln, was to become the British Empire's largest plant breeding and seed company.
A public company from the start, its shares were traded on the London Stock Exchange from 1947.
History of the business
John Garton and his two brothers, Robert and Thomas, were in business with their father, Peter, in Golborne and Newton-le-Willows in Lancashire, England, as corn and agricultural merchants.
As a young man, John Garton (1863–1922), was the first to understand that whilst some agricultural plants were self-pollinating, others were cross-pollinating. He began experimenting with the artificial cross pollination firstly of cereal plants, then herbage species and root crops.
He attracted the friendship and encouragement of a young Scottish seedsman, George Peddie Miln (1861–1928) who had trained in Dundee and was seed manager of Dicksons Limited of Chester.
Knowing he had developed a far reaching new technique in plant breeding John Garton began to carry out many thousands of controlled crosses on fields at the family farm in Newton-le-Willows. He and his colleagues tried in 1889 to interest the UK Government’s new Board of Agriculture in the invention they called Scientific Farm Plant Breeding. But this was to no avail.
Commercial start
Robert and John Garton made a commercial start as R. & J. Garton. They launched their first variety, 'Abundance' oat, in 1892.
Generous publicity followed in the press, together with the publication of articles by botanists in the Journal of the Royal Agricultural Society of England, and in the Transactions of the Royal Highland and Agricultural Society of Scotland in 1894 and 1898. Professor Robert Wallace (1853–1939) of the University of Edinburgh said 'Under the system originated by Mr John Garton an infinite number of new and distinct breeds of oats, barleys, wheats, clovers and grasses have been produced'.
In 1898 a public company was launched, Gartons Limited. It was based in Warrington. Many of the 600 or so subscribers for £50,000 cumulative preference shares of 6% rising to 10% were farmers.
George Peddie Miln joined the company as Managing Director, together with Robert Garton, Thomas R. Garton, Thomas Baxter and Arthur Smith as directors. Robert and John Garton agreed to continue to work for the Company for five years for £500 and to receive the entire ordinary share capital of the new company of £50,000.
It rapidly became the United Kingdom's best known plant breeding and seed company, and also exported seeds widely.
The Garton Lectureship at Edinburgh University
In 1900 an endowment was made to found the Garton Lectureship in Indian and Colonial Agriculture at the University of Edinburgh. The Garton Lectureship still exists as a biennial award to promising young lecturers in the School of Agriculture but is without emoluments and is no longer tied to colonial agriculture.
Publicity in USA
Noel Kingsbury writes:From the late nineteenth century on, seed companies began to play an increasingly important, if not dominant, role in breeding non-cereal crops and a major role in producing varieties for market gardening and for private growers. The production of new cereals was a somewhat different matter - the fact that they were so vitally important for national food supplies and involved large-scale and long-term work made it more likely that they would be the concern of government.
There were exceptions though, one being the family firm of Gartons of Warrington, Lancashire, in the north of England. Their production of cereals - oats in particular - was appreciated as internationally important during the latter quarter of the nineteenth century and the early years of the twentieth; (The American wheat breeder) Mark Carleton visited them in 1898 and was reportedly astonished at their work, Garton varieties were widely exported throughout the British Empire (then by far and away the world's largest political unit) and the United States.
"That private companies could be so effective in breeding cereal grains indicated that there was no link of necessity between their improvement and the publicly funded research that was to so dominate this sector over so much of the next century."
In 1903 Professor Willet M. Hays (1859–1927) of the Agricultural Experiment Station in Minnesota, USA said 'No one has done more brilliant work in Agricultural Plant Breeding than Messrs. Garton, and this is from now on to be recognised.'
Attempted intellectual property donation
The introduction to their 1899 Spring Catalogue reads:
<blockquote>Our original idea for the dissemination of the seed of these new breeds as the stocks became sufficiently large for the purpose, was through some public body as in the form of an annual free seed distribution upon similar lines to the free seed distributions carried out by the Governments of the United States, Canada, and several of the British Colonies.
On three successive occasions we approached Her Majesty's Government with this object in view, the first occasion being on the formation of the Board of Agriculture, in 1889, when we offered to hand over the whole of the valuable results, providing that body would undertake their dissemination and the continuance of the work, either in the form of an annual free seed distribution or at current market price.
Upon the last occasion our offer was accompanied by letters and reports from all the leading Agricultural Professors, Botanists, and Scientists in the Kingdom, setting forth the national benefit which would accrue from the dissemination of the results in the form we had suggested. The final reply of Her Majesty's Government, however, was that whilst fully recognising the value of the work, owing to there being no precedent upon which to act in such a matter, they were unable to avail themselves of the offer. This was much to be regretted for had our ideas been carried into effect the British farmer would have been placed in immediate possession of important results, which in the hands of a Public Company would not reach him for many years.
Our efforts in this direction not having been successful, and as we were not in a position to undertake the work of distribution ourselves, we have placed it in the lands of a Public Company, and we trust that the continued efforts made by us on behalf of the British farmer will be fully appreciated by him, through his support of the Company responsible for the distribution of the seed of our new breeds of agricultural plants
''R. & J. Garton'</blockquote>
Crop innovations
The firm's first historic introduction was 'Abundance' oat, the world's first agricultural plant variety bred from a controlled cross, introduced to commerce in 1892.
Among the other 170 crop varieties that Gartons bred and introduced to commerce were:
'Standwell' barley, introduced in 1898, the first barley bred from a controlled cross.
'White Monarch' wheat, introduced in 1899, the first wheat bred from a controlled cross.
'Invincible' barley, introduced in 1899, the first crop plant control crossed for disease resistance.
Perennialized red clover, introduced in 1898, the first controlled cross clover.
Perennialized Italian ryegrass, introduced in 1907, the first controlled cross pasture grass.
'Apex' winter wheat, introduced in 1967, the first wheat to be granted plant breeders' rights in the United Kingdom.
John Garton's honorary doctorate
On 23 March 1922 the Senatus Academicus of the University of Edinburgh offered to confer the honorary doctorate of LL.D on John Garton shortly before his death, which he duly accepted.Warrington Guardian 26 August 1922 At its meeting on 6 July 1922 the Senatus Academicus learned that John Garton had died.
The programme and report of the Graduation Ceremony held on 21 July 1922 reads The Senatus Academicus recently conferred the Honorary Degree of Doctor of Laws upon the late John Garton, who duly accepted it. The Degree would have been formally conferred on the present occasion but for his lamented death. Mr Garton invented the process of multiple cross fertilisation of crop plants and has been the means in a great measure of revolutionising field culture by producing hundreds of new and improved varieties which have greatly increased the yields of all the common crops of the farm. The achievement proved to be of immense national importance during the War.
Mr Garton first showed that the common grain crops and many other crop plants are self-fertilising. Up till that time they were generally believed to be fertilised by wind or insects.
Mr Garton’s results got in crossing different species of grasses helped to develop the modern conception of species.
Twenty-two tears ago Mr Garton provided the means to establish the Garton Lectures on Colonial and Indian Agriculture, and subsequently he permanently endowed them as an integral part of the work of the Chair of Agriculture.
Plant breeding grounds
The plant breeding grounds were initially at Newton-le-Willows but moved to Acton Grange, two and a half miles south west of Warrington before settling in about 1930 at Little Leigh near Northwich in Cheshire. A seed development farm was located in Essex, and root crop trials were located on farms in the north of England and in Scotland. Traditionally groups of farmers were invited in mid-summer to inspect the plant breeding grounds and be entertained by the Company.
Initially the Seed Warehouse for cleaning and distributing seed was in Newton-le-Willows but moved to Friars Green in Warrington in 1899 by which time the offices were at Thynne Street, Warrington. A purpose built seven story Seed Warehouse and separate Head Office were built at Arpley, Warrington in 1910. There was an L. M. S. railway siding into the Seed Warehouse. On 25 April 1912 the Seed Warehouse burned down but quickly rebuilt largely by the same builders. Seed cleaning machinery, some unique to the Company, ensured the purity of the product. As time went by fewer seeds were ‘picked’ or cleaned by hand by upwards of one hundred staff as machinery became more sophisticated. Across the top of roof of the warehouse was the company’s name which had to be disguised during wartime.
From the beginning Gartons Limited tested its seeds for purity and germination at its own seed testing laboratories in Warrington. The 1920 Seeds Act, for the first time, made testing and declaring for purity and germination a legal requirement for all seed companies. The Official Seed Testing Station was created in 1917, firstly in Victoria Street in Westminster, London and then in 1921 within the newly formed National Institute of Agricultural Botany in Cambridge. Larger seed companies including Gartons Limited were licensed to carry out their own purity and germination testing.
Commercial success and competition
Gartons Limited was the United Kingdom’s only major agricultural plant breeding company. But this caused them difficulties as early as in their Spring 1900 seed catalogue where a paragraph of the introduction reads: It has come to our knowledge that nearly all the New Breeds introduced by us up to the present time have been renamed by various dealers and are being offered by them under different names. Although the honesty of this conduct is more than questionable, we are resigned for the present to regard it as a novel form of flattery, but we strongly recommend all those who wish to secure our Seeds to order them direct from us, as they cannot be procured from any other genuine source.
After the Great War (1914–1918) the United Kingdom government funded cereal breeding at the Plant Breeding Institute at Cambridge which had been founded in 1912, and funded the setting up of plant breeding stations in Edinburgh (1921), Aberystwyth (1919) and in Glasnevin, Northern Ireland in competition with Gartons Limited.
The 1960 Report of the Committee on Transactions in Seeds set up by Parliament entitled Plant Breeders' Rights stated that whilst two thirds of breeding work was by then carried out by government organisations, one third was in the hands of private breeders. And yet the only non-government funded agricultural crop plant breeding, research and testing establishment visited by the Committee was to Gartons Limited. The United Kingdom's Plant Varieties and Seeds Act 1964 allowed plant breeders to fully protect and be rewarded for their introductions. The last variety bred by Gartons, 'Apex' wheat, was the first British bred wheat to be awarded plant breeders rights in 1967 under this legislation.Gartons Headquarters Plant Breeding Grounds in Cheshire, from The Warrington Examiner 4 April 1931.
Chairmen and directors
The eldest of the three Garton brothers, Robert Garton, was the first chairman of Gartons Limited. He died in February 1950, aged 91, a widower with no children. He was succeeded by the youngest brother, Thomas R. Garton, who died in May 1956. His son, John, was chairman from August 1963 until September 1965. Dr John Garton, the middle of the three brothers, was never, a director.
Nine members of the Miln family were involved with the business over a period of seventy five years.
Born at Linlathen, Broughty Ferry in 1861, George Peddie Miln trained in a Dundee seed warehouse, the traditional Scottish training for a young man with ambition in the seed trade. He moved to Chester and ran one of its old established seed merchants before joining Gartons Limited as its first Managing Director in 1898. He was a member of Her Majesty's Board of Agriculture Seeds Advisory Council during the first World War. Both the Seeds Act 1920 and the formation of the National Institute of Agricultural Botany came about with his considerable encouragement during his three-year presidency of the Seed Trade Association of the United Kingdom. Of his eleven children, five trained in the seed trade. He was a Justice of the Peace in the City of Chester, a Fellow of the Linnean Society and a member of the Council of the Royal Agricultural Society of England. He died aged 68 following an unsuccessful operation.
When George P. Miln died in 1928 he was succeeded as managing director by his eldest son, Thomas Edward Miln (1890–1963) who for over twenty five years was chairman of the Retail Committee of the Seed Trade Association of the United Kingdom which proudly kept its independence from government control during World War II. A plant breeder as well as a businessman he is credited with the introduction of the sugar beet crop to UK agriculture.
When Gartons Limited became a public quoted company on the London Stock Exchange in 1947 T. E. Miln entered into a further ten year employment contract as Managing Director, even though he was already 59, such was his reputation. Both his sons, Wallace and George, joined him in the business.
T. E. Miln was succeeded in 1961 by his elder son, Wallace Miln (1919–1994) also a skilled plant breeder and seed analyst. Wallace Miln was one of the three founders of the British Association of Plant Breeders at the time of the introduction of the United Kingdom's Plant Varieties and Seeds Act 1964. He was twice President of the Seed Trade Association of United Kingdom. He left Gartons Limited in 1973 to join his elder son, Barnaby Miln, who had trained at Gartons and later with Northrup-King in Minneapolis before setting up his own seed business at Bodenham in Herefordshire.
From 1947 Gartons Limited's shares were quoted on the London Stock Exchange. The Company's profits for the previous seven years had averaged £48,940. In 1949 the profit of £75,340 was the highest ever recorded by the Company.
In 1965 Peter Darlington became chairman of Gartons Limited. In a dramatic change of direction in 1967 Gartons Limited ceased retailing seeds directly to farmers. Instead a new brand was created, Gartons GROplan, and marketing became wholesale through agricultural merchants throughout the United Kingdom.
In 1970 Charles Hoskins became Production Director. Charles Hoskins had previously been with Twyford Seeds and spent twelve years as General Manager of Conder Seeds having under the directorship of his brother Peter Hoskins been responsible for the inception of this profitable and successful business.
Decline following Acquisition of Gartons Groplan By Agricultural Holdings (Hurst Gunson)
Gartons GROplan was sold to Agricultural Holdings Company Limited (Hurst Gunson) in 1971, but Gartons Limited continued as a plant breeding company. Peter Darlington immediately resigned from Gartons Groplan to concentrate on his responsibilities with Gartons Limited and Peter Darlington Partners. Wallace Miln and Charles Hoskins both left Gartons Groplan following the take over by Agricultural Holdings Limited (Hurst Gunson). As already stated Wallace Miln joined his son Barnaby at JB Seeds and Charles Hoskins joined Sinclair McGill, the highly respected Boston based Plant Breeders and Seed Specialists, in 1974 and was appointed Production Director at Sinclair McGill (East) in 1978
Bob Beeton was another senior employee to leave following the take over by Agricultural Holdings Limited (Hurst Gunson.) Bob Beeton had been Sales Manager at Garton Groplan and in 1974 joined Elsoms Spalding, the Spalding based Plant Breeders and Seed Specialists, as Area Sales Manager for East Anglia. Elsoms Spalding remains a family company to this day. Elsoms Spalding still enjoys a justifiable excellent reputation.
Gartons plc, as it became known, ceased trading in 1983. The seed warehouse at Bridge Foot, Warrington, which had dominated the town centre skyline since 1910, was demolished in October 1986. A hotel was built on the site.
The Garton System of Plant Breeding
These Explanatory Notes come from the Gartons Seed Catalogue for Spring 1900:
To those who are not acquainted with the botanical construction of plants it may be well to explain that plants possess generative organs, which correspond to those of the male and female in the animal kingdom. In the animal kingdom, progeny is derived from the mating of different animals of the same breed; in the vegetable kingdom the rule is that the seed is produced through the agency of the generative organs growing together on the same plant. Prior to the commencement of the work initiated by us and carried on during the past 20 years, which has led to the production of our New and Improved Breeds of agricultural plants, it was a recognised belief that many farm plants in the production of their seed were more or less cross-fertilised. The results of our experiments however have proved that such was not the case but that constant in-and-in breeding was the rule.
Where such in-and-in breeding takes place the results are governed by the same natural laws as the in-and-in breeding of animals. In the production of New Breeds of animals the rule followed is to mate two animals of distinct breeds. The progeny, when fixity of type has been secured, constitutes a New Breed.
Under our system of plant breeding we carry the mating of varieties or breeds far beyond what is practised in the animal kingdom. In the first instance we mate varieties and also what were formerly regarded as distinct species of the same genera, and after fixation, the progeny by these combinations are further mated together.
A further extension of our system which is in itself unique and instructive, is the mating of uncultivated indigenous plants of the same Natural Order as the cultivated varieties. From such combinations most valuable results have been obtained.
For example In Southern Asia there exists a species of wheat botanically known as Triticum spelta. In some districts it is looked upon as an indigenous weed infesting the cultivated crops of wheat.
Under no climatic conditions does the grain of this species shed its seed when ripe, and even in threshing it is not possible to separate the grains, as the spikelets break off at the bases of the glumes, the grains remaining firmly enclosed between the chaff scales.
By mating the varieties of this species with cultivated varieties, new breeds have been produced which will under no conditions shed their seed when ripe, but which thresh out a perfectly clean sample with a much heavier yield per acre than common wheat.
In China there is an indigenous species of oat botanically known as Avena nuda or naked oat. The peculiar feature of this species is that the grains (which are very small) grow without any husk, being protected only by the chaff. The habit of the plant is likewise quite unique, four or five grains being suspended upon a thread-like filament about half an inch long. The mating of this species with cultivated varieties has produced new breeds giving yields 50 to 100 per cent. heavier than the original cultivated parents, with a corresponding decrease in the thickness of the skin.
The wild or land oat, Avena fatua, of Great Britain has likewise been used with marked success in the production of new breeds in conjunction with the cultivated varieties. In the wild oat there is hardiness of constitution, vigour, strength of straw, and remarkable fertility. All these qualities have been retained in the new breeds produced.
Another part of our system is the improvement of existing varieties of agricultural plants. The method is similar to that adopted by the breeder of stock for the improvement of his animals, when fresh blood of the same breed is introduced from some other herd.
By crossing two distinct plants of the same variety the resulting progeny is more vigorous and robust in constitution, whilst the habit and individual character of the variety is maintained. A year later, these Explanatory Notes come from the Gartons Seed Catalogue for Spring 1901:'''
FOR over 20 years the work of cross-fertilising crop plants, with the object of producing New and Improved Breeds, has been carried on at Newton-le-Willows in Lancashire. It has there for the first time been demonstrated to Scientific Botanists as well as to Agriculturists that all the corn crops (cereals) and nearly all the other common crops of the farm are self fertilising. In other words, each individual plant provides the pollen which is required in the process of producing seed, to fertilise the female organs of its own flowers. This natural process results in a perfect system of in-breeding which has been going on for an indefinite period, making it possible to grow the different varieties of crops of the same kind in close proximity to each other, and even as mixed crops without any danger of crosses being produced.
If crossing could have occurred in nature it would have been quite impossible to maintain the purity of any variety of crop plant for more than a year or two. As in the Animal Kingdom, the in-breeding of plants tends to the decrease of constitutional vigour, consequently when cross-fertilisation is practised the size and vigour of the selected progeny are increased in a remarkable degree.
Although the natural laws which govern the Animal and the Vegetable Kingdoms bear a very strong resemblance to each other, further points can be realised and greater progress can be made in a limited time with plants than with animals under a system of cross breeding.
Not only have varieties of a given species, but what were formerly regarded as distinct species belonging to the same genus, been successfully mated.
The tendency to sterility in their progeny is overcome by introducing pollen from one or other '01' the original plants, it being the male organs of reproduction that are liable to be absent or defective in the progeny of two extremely divergent parent plants. Many varieties as well as species can thus be blended in the formation of a new breed, but as it is necessary to secure fixity of type in every cross bred plant before it is again used for crossing, the labour and care involved are very considerable.
Attempts at the production of first crosses are not new, as these have been practised for many years by experimenters in the same field, who however stopped short of the point at which the Garton System achieved its greatest results, viz. by compound or multiple crossing. This further stage of the work of cross fertilisation leads to a thorough dislocation of the usual course of the law of inheritance by which "like produces like." In the wilderness of uncertainty and confusion which follows and in which the great majority of the progeny are found to be abortive or inferior, a few choice specimens appear which are grown for a number of years until fixity of type has been secured. These superior and selected specimens are adopted as suitable for cultivation, and a number of them are described in this Catalogue and offered to the public as much superior to the old varieties from which they were derived by the Garton System of Plant Breeding. In making the selections the large quantity and superior quality of the grain, together with great standing power in the straw have been the chief characteristics aimed at, and if these desiderata have been secured in a few of the new breeds to the detriment of the habit of "tillering," the difficulty is readily overcome by providing a liberal seeding.
Some of the most striking and valuable results have been achieved by introducing as progenitors, certain weeds belonging to the same natural order of plants as the cultivated parents. For example, an inferior variety of "spelt" wheat Triticum spelta from Southern Asia, has been employed with excellent results to introduce strength of gluten to the grain, and large yielding and standing power to the crop with immunity from shedding its seed during harvest.
A wild naked Oat, Avena nuda, indigenous to China has been used to produce new breeds which yield in some instances 100 per cent. more than their cultivated parents. Four or five grains are suspended in each spikelet by a thread like filament about half-an-inch long. This peculiar habit of the plant 'has been extended in the progeny and an' accompanying illustration shows a spikelet with no fewer than 14 grains in it.
The hardiness of constitution, standing power of straw, and remarkable fertility of the wild or land oat, Avena fatua, of Great Britain have been successfully introduced, but not without many difficulties, into some of the new breeds.
Some progress has also been made with the improvement of existing varieties of Agricultural plants by introducing pollen from plants of the same variety to increase the vigour of the plant without materially altering its general characteristics.
Varieties Bred and Introduced
Source:
Barley Varieties:
Barley varieties bred and introduced to UK agriculture include Standwell in 1898, Invincible (1899), Zero (1900), Brewer’s Favourite (1901), The Maltster (1903), Eclipse (1904), Ideal (1906), 1917 (1918), Admiral Beatty (1920), Triumphant (1927).
Oat Varieties:
Oat varieties bred and introduced to UK agriculture include Abundance in 1892, Pioneer (1899), Tartar King (1899), Waverley (1900), Goldfinder (1901), Storm King (1902), Excelsior (1903), Colossal (1904), Rival (1906), Unversed (1907), Bountiful (1908), The Yielder (1909), The Record (1911), The Leader (1913), Supreme (1915), The Hero (1916), The Captain (1919), Sir Douglas Haig (1920), Marvellous (1921), Superb (1923), Earl Haig (1925), Cropwell (1926), Plentiful (1927), Black Prince (1929), Progress (1930), Unique (1931), Onward (1935), Jubilee (1936), Royal Scot (1940), Spitfire (1945), Early Grey (1946), Forward (1953), Angus (1959).
Wheat Varieties:
Wheat varieties bred and introduced to UK agriculture include White Monarch in 1899, White Pearl (1900), Red King (1900), New Era (1903), Reliance (1909), Victor (1910), Benefactor (1914), Early Cone (1918), The Hawk (1918), Marshal Foch (1919), Rector (1923), Benefactress (1925), Renown (1926), Wilhelmina Regenerated (1928), Gartons No 60 (1932), Gartons Q3 (1933), Redman (1934), Little Tich (1935), Wilma (1936), Warden (1938), Meteor (1941), Pilot (1945), Welcome (1950), Masterpiece (1951), Alpha (1952), Victor II (1953), Ritchie (1957), Apex (1965).
Swede Varieties:
Swede varieties bred and introduced to UK agriculture include Zero in 1900, Lord Derby (1900), Perfection (1900), Monarch (1900), Model (1900), Green Tankard (1901), Keepwell (1902), Cropwell (1903), Superlative (1905), Victory (1907), Incomparable (1907), Warrington (1914), Acme (1914), Magnificent (1917), Viking (1918), Feedwell (1922), White Fleshed (1933), Parkside (1951), Townhead (1951).
Turnip Varieties:
Turnip varieties bred and introduced to UK agriculture include Mammoth Purpletop in 1900, Greentop Scotch Yellow (1900), Hardy Green Globe (1900), Pioneer (1903), Purpletop Long Keeping (1912), Deep Golden Yellow Long Keeping (1912), The Bruce (1917), The Grampian (1920), The Wallace (1935).
Sugar Beet Varieties:
Sugar Beet varieties bred and introduced to UK agriculture include Gartons in 1909, Gartons C (1941) and Gartons Number 632 (1962).
Kale and Kail Varieties:
Kale varieties bred and introduced to UK agriculture include Thousand Headed in 1902, Marrow Stem Kail (1912), Gartons Hybrid (1937) and Hungry Gap (1941).
Kohl Rabi Varieties:
Kohl Rabi varieties bred and introduced to UK agriculture include Large Green in 1902 and Improved Short Top in 1904.
Mangel Varieties:
Mangel varieties bred and introduced to UK agriculture include Large Yellow Intermediate in 1900, Mammoth Long Red (1900), Golden Tankard (1900), Large Yellow Globe (1900), Select Golden Globe (1900), Sugar (1905), Red Intermediate (1905), Devon Yellow Intermediate (1907), Golden Gatepost (1909), Large Red Globe (1910), Large Golden Globe (1910), Nonsuch (1917), Sunrise (1919), White Knight (1922), New Combination (1924), Lemon Globe (1927), Gartons Number 432 (1928), Gartons Number 47 (1931), White Chief (1935), Gartons Number 601 (1960).
Rape Varieties:
Rape varieties bred and introduced to UK agriculture include Broadleaved in 1906, Early Giant (1947) and Late Dwarf (1947).
Herbage Grass Varieties:
Herbage grass varieties bred and introduced to UK agriculture include Hatchmere Perennial Ryegrass in 1899, Ellesmere Perennialized Italian Ryegrass (1907), Pickmere Perennial Ryegrass (1932), Delamere Cocksfoot (1936), Oakmere Timothy (1940), Flaxmere (1952), Gartons Tall Fescue (1955), Marbury Meadow Fescue (1957), Barmere Timothy (1958).
Clover Varieties:
Clover varieties bred and introduced to UK agriculture include Giant Cowgrass in 1898, Perennial Cowgrass (1898), Perennialized Broad Red Clover (1898), Gartons White Clover (1898) and Broad Red Clover (1907).
Field Cabbage Varieties:
Field Cabbage varieties bred and introduced to UK agriculture include Early Ox Heart in 1900, Extra Early Express (1900), Early Drumhead (1900), Selected Drumhead Savoy (1902), Selected Ormskirk Savoy (1902), Gartons Cattle Drumhead (1904), Giant Purple Flat Poll (1917), Utility (1924), Intermediate Drumhead (1924), Gartons Primo (1939).
Field Carrot Varieties:
Field Carrot varieties bred and introduced to UK agriculture include Scarlet Intermediate in 1900, Mid Season Scarlet (1911), Mammoth White (1924), Intermediate Stump Rooted (1935), Red Cored Early Market (1935), Short Stump Rooted (1938), Giant White (1939).
Lupin, Parsnip, Potato, Sprouting Broccoli, Winter Beans and Winter Rye Varieties:
Other crop varieties bred and introduced to UK agriculture include Gartons Lupin in 1922, Gartons Field Parsnips (1902), Gartons Number 12 Potato (1912), Gartons Purple Sprouting Broccoli (1903), Gartons Giant Winter Bean (1922), GS Giant Winter Bean (1950), P/L 14 Giant Winter Bean (1954), Gartons Giant Large Grained Winter Rye (1922).
References
Agronomy
Molecular biology
Plant reproduction
Pollination management
Plant breeding
Seed companies
Agriculture companies of the United Kingdom | Gartons Limited | Chemistry,Biology | 6,812 |
34,985,593 | https://en.wikipedia.org/wiki/Fractal%20catalytic%20model | A fractal catalytic model is a mathematical representation of chemical catalysis in an environment with fractal characteristics.
References
Fractals
Catalysis | Fractal catalytic model | Chemistry,Mathematics | 33 |
181,568 | https://en.wikipedia.org/wiki/NMEA%200183 | NMEA 0183 is a combined electrical and data specification for communication between marine electronics such as echo sounder, sonars, anemometer, gyrocompass, autopilot, GPS receivers and many other types of instruments. It has been defined and is controlled by the National Marine Electronics Association (NMEA). It replaces the earlier NMEA 0180 and NMEA 0182 standards. In leisure marine applications, it is slowly being phased out in favor of the newer NMEA 2000 standard, though NMEA 0183 remains the norm in commercial shipping.
Details
The electrical standard that is used is EIA-422, also known as RS-422, although most hardware with NMEA-0183 outputs are also able to drive a single EIA-232 port. The standard calls for optically isolated inputs. There is no requirement for isolation for the outputs.
The NMEA 0183 standard uses a simple ASCII, serial communications protocol that defines how data are transmitted in a "sentence" from one "talker" to multiple "listeners" at a time. Through the use of intermediate expanders, a talker can have a unidirectional conversation with a nearly unlimited number of listeners, and using multiplexers, multiple sensors can talk to a single computer port.
At the application layer, the standard also defines the contents of each sentence (message) type, so that all listeners can parse messages accurately.
While NMEA 0183 only defines an RS-422 transport, there also exists a de facto standard in which the sentences from NMEA 0183 are placed in UDP datagrams (one sentence per packet) and sent over an IP network.
The NMEA standard is proprietary and sells for at least US$2000 (except for members of the NMEA) as of September 2020. However, much of it has been reverse-engineered from public sources.
UART settings
There is a variation of the standard called NMEA-0183HS that specifies a baud rate of 38,400. This is in general use by AIS devices.
Message structure
All transmitted data are printable ASCII characters between 0x20 (space) to 0x7e (~)
Data characters are all the above characters except the reserved characters (See next line)
Reserved characters are used by NMEA0183 for the following uses:
Messages have a maximum length of 82 characters, including the $ or ! starting character and the ending <LF>
The start character for each message can be either a $ (For conventional field delimited messages) or ! (for messages that have special encapsulation in them)
The next five characters identify the talker (two characters) and the type of message (three characters).
All data fields that follow are comma-delimited.
Where data is unavailable, the corresponding field remains blank (it contains no character before the next delimiter – see Sample file section below).
The first character that immediately follows the last data field character is an asterisk, but it is only included if a checksum is supplied.
The asterisk is immediately followed by a checksum represented as a two-digit hexadecimal number. The checksum is the bitwise exclusive OR of ASCII codes of all characters between the $ and *, not inclusive. According to the official specification, the checksum is optional for most data sentences, but is compulsory for RMA, RMB, and RMC (among others).
ends the message.
As an example, a waypoint arrival alarm has the form:
$GPAAM,A,A,0.10,N,WPTNME*32
Another example for AIS messages is:
!AIVDM,1,1,,A,14eG;o@034o8sd<L9i:a;WF>062D,0*7D
NMEA sentence format
The main talker ID includes:
BD or GB - Beidou
GA - Galileo
GP - GPS
GL - GLONASS.
NMEA message mainly include the following "sentences" in the NMEA message:
One example, the sentence for Global Positioning System Fixed Data for GPS should be "$GPGGA".
Vendor extensions
Most GPS manufacturers include special messages in addition to the standard NMEA set in their products for maintenance and diagnostics purposes. Extended messages begin with "$P". These extended messages are not standardized.
Software compatibility
NMEA 0183 is supported by various navigation and mapping software. Notable applications include:
Infrakit SURVEY
DeLorme Street Atlas
ESRI
Google Earth
Google Maps Mobile Edition
gpsd - Unix GPS Daemon
JOSM - OpenStreetMap Map Editor
MapKing
Microsoft MapPoint
Microsoft Streets & Trips
NetStumbler
OpenCPN - Open source navigation software
OpenBSD's hw.sensors framework with the nmea(4) pseudo-device driver
OpenNTPD through sysctl API
Rand McNally StreetFinder
ObserVIEW
QGIS
Sample file
A sample file produced by a Tripmate 850 GPS logger. This file was produced in Leixlip, County Kildare, Ireland. The record lasts two seconds.
$GPGGA,092750.000,5321.6802,N,00630.3372,W,1,8,1.03,61.7,M,55.2,M,,*4E
$GPGSA,A,3,10,07,05,02,29,04,08,13,,,,,1.72,1.03,1.38*0A
$GPGSV,3,1,11,10,63,137,17,07,61,098,15,05,59,290,20,08,54,157,30*70
$GPGSV,3,2,11,02,39,223,19,13,28,070,17,26,23,252,,04,14,186,14*79
$GPGSV,3,3,11,29,09,301,24,16,09,020,,36,,,*76
$GPRMC,092750.000,A,5321.6802,N,00630.3372,W,0.02,31.66,280511,,,A*43
$GPGGA,092751.000,5321.6802,N,00630.3371,W,1,8,1.03,61.7,M,55.3,M,,*75
$GPGSA,A,3,10,07,05,02,29,04,08,13,,,,,1.72,1.03,1.38*0A
$GPGSV,3,1,11,10,63,137,17,07,61,098,15,05,59,290,20,08,54,157,30*70
$GPGSV,3,2,11,02,39,223,16,13,28,070,17,26,23,252,,04,14,186,15*77
$GPGSV,3,3,11,29,09,301,24,16,09,020,,36,,,*76
$GPRMC,092751.000,A,5321.6802,N,00630.3371,W,0.06,31.66,280511,,,A*45
Note some blank fields, for example:
GSV records, which describe satellites 'visible', lack the SNR (signal–to–noise ratio) field for satellite 16 and all data for satellite 36.
GSA record, which lists satellites used for determining a fix (position) and gives a DOP of the fix, contains 12 fields for satellites' numbers, but only 8 satellites were taken into account—so 4 fields remain blank.
Status
NMEA 0183 continued to be maintained separately: V4.10 was published in early May 2012, and an erratum noted on 12 May 2012.
On November 27, 2018, it was issued an update to version 4.11, which supports Global Navigation Satellite Systems other than GPS.
See also
GPS Exchange Format
TransducerML
IEEE 1451
IEC 61162
NMEA 2000
NMEA OneNet
RTCM SC-104
RINEX
References
External links
National Marine Electronics Association
NMEA's website about NMEA 0183
NMEA Specifications at APRS Info
Global Positioning System
Network protocols
Computer buses
Marine electronics
Satellite navigation | NMEA 0183 | Technology,Engineering | 1,808 |
11,586,432 | https://en.wikipedia.org/wiki/Henry%20P.%20H.%20Bromwell | Henry Pelham Holmes Bromwell (August 26, 1823 – January 9, 1903) was an American lawyer, politician from Illinois, and prominent Freemason. He was a lawyer and judge who served as a U.S. representative from Illinois from 1865–1869 and continued to practice law when he moved to Colorado in 1870 where he was appointed to compile the state's statutes. Bromwell was initiated into freemasonry in 1854, and he became the Grand Master of Illinois in 1864. When he moved to Colorado he became that state's first Honorary Grand Master. He developed the Free and Accepted Architects, a new rite for Freemasonry which sought to teach its initiates the lost work of the craft embodied in Bromwell's Geometrical system. After his death, the Grand Lodge of Colorado published his work on the esoteric nature of Sacred geometry in the book Restorations of Masonic Geometry and Symbolry.
Family and education
Born in Baltimore, Maryland, Bromwell moved with his parents to Cincinnati, Ohio, in 1824, and thence to Cumberland County, Illinois, in 1836.
He attended private schools in Ohio and Illinois, including Marshall Academy (Marshall, Illinois), becoming an instructor in that academy in 1844. In 1867 he obtained an honorary degree of Master of Arts from McKendree College for his wide reputation for scholarship.
On June 20, 1858, Bromwell married Emily E. Payne. They had three children together, Emma M. Bromwell (1864–1865), Henry Pelham Payne Bromwell (1862–1881), and Henrietta Elizabeth Bromwell (1859–1946). Emma died around the same time as his wife in February 1865. Henry Jr. caught typhoid fever and died in Denver at the age of nineteen; he was studying law at the time.
After twenty years fighting sickness, Bromwell died in Denver, Colorado, January 9, 1903. He was interred in Riverside Cemetery.
Law and politics
In 1848 the family moved to Vandalia, Illinois, where Bromwell worked for his father's newspaper, The Age of Steam, and studied law. Bromwell was admitted to the bar in 1853 and practiced in Vandalia until 1858. Soon after being admitted to the bar, he was elected County Judge of Fayette County, Illinois as well as ex-officio chairman of the County Board and charged with rebuilding the courthouse. While practicing law in Vandalia, Bromwell was "a member of the same bar as Mr. Lincoln, Politically of the same faith, he and the Judge [Bromwell] were naturally warm friends." In 1860 Bromwell was elected as a Presidential Elector for Lincoln. He moved to Charleston, Illinois, in 1857. Bromwell was elected as a Republican to the Thirty-ninth and Fortieth Congresses (March 4, 1865 – March 3, 1869).
In October–November 1870 Bromwell moved to Colorado Territory, arriving on November 10, where he was elected as a member of the territorial legislature in 1873–1874, "the highest legislative body of the territory." In 1875, he was elected as a member of the state's constitutional convention and in 1878 he was elected to the first Legislature of the State of Colorado serving in the House of Representatives, and appointed Commissioner to revise the laws of the state in 1881.
Freemasonry
Bromwell was made a Freemason in Vandalia, Illinois, in 1854. He was a member of Temperance Lodge No. 16, where he served as Worshipful Master from 1856–1857. When he moved to Charleston he joined Charleston Lodge No. 35, where he served as Worshipful Master from 1858–1863, as well as serving as Grand Orator for the Grand Lodge of Illinois. He later was chosen as Grand Master for the Grand Lodge of Illinois in 1864 or 1865 (reports vary).
After moving to Colorado in 1870, he formally joined Denver Lodge #5 in 1874. That same year he served as Grand Orator of the Grand Lodge of Colorado. During the 1889 Grand Lodge annual communication he was unanimously elected as honorary member of the Grand Lodge of Colorado 1889 "in consideration of his distinguished services to the Craft" as well as "a slight evidence of our appreciation of and regard for his high masonic and personal character." This was the first time that someone was nominated as an honorary member of the Grand Lodge of Colorado, and he would remain the only honorary member up to the time of his death in 1903. This motion was proposed because "[Bromwell] does not need this honor to add to his fame as a wise and good mason, but because we honor ourselves in honoring him".
On January 11, 1903, the Grand Lodge of Colorado conducted the funeral service for Bromwell with Past Grand Master Lawrence Greenleaf acting as Grand Master. Among his pall bearers were eight Past Grand Masters, and the religious services were conducted at his residence.
Free and Accepted Architects
Bromwell was the originator of the Free and Accepted Architects, a new branch of freemasonry "the object of which was to restore and preserve the lost work [rituals] of the ancient craft." The Rite itself has been described as "Bromwell surrounded by a few brethren interested in his geometrical system" The rite was "based on a geometrical system evolved in 1859" by Bromwell which contained the "most valuable information which should not be issued except through a series of degrees." The original rite consisted of two degrees, known as "Select Architects" and "Most Excellent Architect"; on May 26, 1875, the "Royal Architects" degree was added. These degrees were not innovations introduced into freemasonry but rather "designed to impart to students of the Craft a knowledge of Masonic symbolism not otherwise obtainable."
On March 1, 1862, a grand lodge of Free and Accepted Architects was formed, "known as King Davids Grand Lodge F.&A.A." The Grand Lodge moved to Denver in 1879, the first meeting in the new location being on June 9 of that year. In the twenty-one years of the Grand Lodge's existence there were nine Grand Master Architects and five lodges mentioned in their minutes: King David's No. 1 Charleston Illinois; King Solomon's No. 2 Washington D.C.; King Hiram's No. 3 Springfield Ill.; Hillsborow No. 4 Hillsboro, Ill.; Pentalpha No. 5 Denver, Col.; with a dispensation issued to Triangle, Los Angeles, Cal. The Grand Lodge continued until 1883, when it held its last meeting on March 6.
After the last Grand Lodge meeting Frank Church, the Grand Master Architect, continued obligating people into the rite. Several attempts were made to revive the lodge, but they all ended up in failure. Finally Harry Bundy, the Grand Secretary of Colorado, gained access to the rite and on December 29, 1958, Bundy obligated several individuals and opened the Grand Lodge of Architects. At this meeting they elected George B. Clark as Grand Master Architect and Harry W. Bundy as the Grand secretary. Afterwards they agreed to meet in Washington D.C. to elect the remaining officers. On February 20, 1959, the Grand Lodge of Architects met, elected a total of fifteen officers, and then turned the ritual over to the Allied Masonic Degrees and placed it in the custody of the Grand College of Rites; "there would be no initiations and the Rite would remain dormant as far as extension of its membership and authority would be concerned."
Restorations of Masonic Geometry and Symbolry
In 1884, Bromwell began work on what was to become his life work, entitled Restorations of Masonic Geometry and Symbolry. This book, in a resolution passed by the Grand Lodge of Illinois, is described as "The most remarkable contribution, along the lines of which it treats, yet made to Masonic Literature." To write this "ponderous volume" it is claimed that Bromwell spent "sixteen hours a day for six years and two months" working on what he described as "a dissertation on the lost knowledge of the Lodge." Chapter Nine, dedicated to the floors of the three lodges and titled "The Floor of the Lodge," "occupied two years and two months in its preparation." This claim has been directly challenged by Coil, who argues that "there is not enough known or ascertainable about the working of ancient or medieval lodges, including those up to the middle of the 18th century to occupy an author more than a few days for the telling of the whole story." While Coil did not have access to any of Bromwell's work, he disparages the entire project stating that "the fact that the five lodges established by Bromwell [The Free and Accepted Architects] soon lapsed and that the entire subject matter, including the book, is entirely forgotten, except for encyclopedic items, sufficiently indicates the lack of value in the work."
The year that Bromwell died, the "Henry P. H. Bromwell Masonic Publication Company" was formed for the sole purpose of publishing Restorations of Masonic Geometry and Symbolry The board of directors for this company was composed entirely of Past Grand Masters. The Grand Lodge of Colorado met on the year of his death and discussed how to best honor Bromwell's work. After the character of the work was explained, "showing that it would be one of the most valuable Masonic publications ever produced", the Grand Lodge of Colorado voted "that the proper officers of the Grand Lodge be authorized to guarantee $2000 towards the expenses of the publication of the work." The book was published in 1905.
References
1823 births
1903 deaths
Colorado state court judges
Esoteric cosmology
American geometers
Illinois lawyers
Illinois state court judges
Lawyers from Baltimore
Lawyers from Denver
Masonic grand masters
Members of the Colorado Territorial Legislature
Members of the Colorado House of Representatives
People from Charleston, Illinois
People from Vandalia, Illinois
Politicians from Baltimore
Politicians from Denver
Republican Party members of the United States House of Representatives from Illinois
Sacred geometry
Writers from Denver
Burials at Riverside Cemetery (Denver, Colorado)
19th-century members of the United States House of Representatives | Henry P. H. Bromwell | Engineering | 2,095 |
15,224,513 | https://en.wikipedia.org/wiki/PTPRCAP | Protein tyrosine phosphatase receptor type C-associated protein is an enzyme that in humans is encoded by the PTPRCAP gene.
The protein encoded by this gene was identified as a transmembrane phosphoprotein specifically associated with tyrosine phosphatase PTPRC/CD45, a key regulator of T- and B-lymphocyte activation. The interaction with PTPRC may be required for the stable expression of this protein.
References
Further reading | PTPRCAP | Chemistry | 104 |
35,190,669 | https://en.wikipedia.org/wiki/Visceral%20pain | Visceral pain is pain that results from the activation of nociceptors of the thoracic, pelvic, or abdominal viscera (organs). Visceral structures are highly sensitive to distension (stretch), ischemia and inflammation, but relatively insensitive to other stimuli that normally evoke pain such as cutting or burning.
Visceral pain is diffuse, difficult to localize and often referred to a distant, usually superficial, structure. It may be accompanied by symptoms such as nausea, vomiting, changes in vital signs as well as emotional manifestations. The pain may be described as sickening, deep, squeezing, and dull. Distinct structural lesions or biochemical abnormalities explain this type of pain in only a proportion of patients. These diseases are grouped under gastrointestinal neuromuscular diseases (GINMD). Others can experience occasional visceral pains, often very intense in nature, without any evidence of structural, biochemical or histolopathologic reason for such symptoms. These diseases are grouped under functional gastrointestinal disorders (FGID) and the pathophysiology and treatment can vary greatly from GINMD. The two major single entities among functional disorders of the gut are functional dyspepsia and irritable bowel syndrome.
Visceral hypersensitivity is hypersensitive visceral pain perception, which is commonly experienced by individuals with functional gastrointestinal disorders.
Epidemiology
In the past, viscera were considered insensitive to pain but now it is clear that pain from internal organs is widespread and that its social burden may surpass that of pain from superficial (somatic) sources. Myocardial ischemia, the most frequent cause of cardiac pain, is the most common cause of death in the United States. Urinary colic produced from ureteral stones has been categorized as one of the most intense forms of pain that a human being can experience. The prevalence of such stones has continuously increased, reaching values of over 20% in developed countries. Surveys have shown prevalence rates among adults of 25% for intermittent abdominal pain and 20% for chest pain; 24% of women experience pelvic pain at any point in time. For over two-thirds of those affected, pain is accepted as part of daily life and symptoms are self-managed; a small proportion defer to specialists for help. Visceral pain conditions are associated with diminished quality of life, and exert a huge cost burden through medical expenses and lost productivity in the workplace.
Clinical presentation
Visceral pain should be suspected when vague midline sensations of malaise are reported by a patient. True visceral pain is characterized as a vague, diffuse, and poorly defined sensation. Regardless of specific organ of origin, the pain is usually perceived in the midline spanning anywhere from the lower abdomen up to the chest. In the early phases the pain is perceived in the same general area and it has a temporal evolution, making the onset sensation insidious and difficult to identify.
The pain is typically associated with involvement of the autonomic nervous system. Some of these symptoms include pallor, sweating, nausea, vomit, changes in vital signs including blood pressure, heart rate and/or temperature. Strong emotional reactions are also common presenting signs and may include anxiety, anguish and a sense of impending doom. Visceral pathology may also manifest only through emotional reactions and discomfort where no pain is reported. The intensity of visceral pain felt might have no relationship to the extent of internal injury.
Visceral pain changes in nature as it progresses. Pain from a specific organ can be experienced, or "referred" to different sites of the body. There is no pathology or no cause for pain at these referred somatic sites however the pain will be experienced at this location, often with significant intensity. Referred pain is sharper, better localized, and less likely to be accompanied by autonomic or emotional signs.
A good example of visceral pain that is common place and embodies the wide spectrum of clinical presentations discussed above is a myocardial infarction (MI), more commonly known as a heart attack. This pain is secondary to ischemia of the cardiac tissue. The most common presenting symptom is chest pain that is often described as tightness, pressure or squeezing. The onset of symptoms is usually gradual, over several minutes and tends to be located in the central chest (overlying the sternum) although it can be experienced in the left chest, right chest, and even abdominal area. Associated symptoms, which are mostly autonomic in nature, include diaphoresis, nausea, vomiting, palpitations, and anxiety (which is often described as a sense of impending doom). Referred pain is experienced most commonly radiating down the left arm however it can also radiate to the lower jaw, neck, back and epigastrium. Some patients, especially elderly and diabetics, may present with what is known as a painless myocardial infarction or a "silent heart attack". A painless MI can present with all of the associated symptoms of a heart attack, including nausea, vomiting, anxiety, heaviness, or choking, but the classic chest pain described above is lacking.
It is always important for not only the physician but also the patient to remember the dissociation between magnitude of injury to internal organs and the intensity of pain and how this can be potentially dangerous if overlooked, for example a silent heart attack. More rarely intense visceral pain does not signify a significant pathologic process, for example intense gas pains.
Neurobiology
The vague and poorly defined sensation as well as its temporal nature, characteristic of visceral pain, is due to the low density of sensory innervation of viscera and the extensive divergence of visceral input within the central nervous system (CNS).
The phenomenon of referred pain is secondary to the convergence of visceral afferent (sensory) nerve fibers entering the spinal cord at the same level as the superficial, somatic structures experiencing the pain. This leads to a misinterpretation of incoming signals by higher brain centers.
Treatment
There are two goals when treating visceral pain:
to alleviate the current experience of pain and
to address any underlying pathology, if and when identifiable.
Treatment of the pain in many circumstances should be deferred, until the origin of the symptoms has been identified. Masking pain may confound the diagnostic process and delay the recognition of life-threatening conditions. Once a treatable condition has been identified there is no reason to withhold symptomatic treatment. Also, if cause for the pain is not found in reasonable time then symptomatic treatment of the pain could be of benefit to the patient in order to prevent long-term sensitization and provide immediate relief.
Symptomatic treatment of visceral pain relies primarily upon pharmacotherapy. Since visceral pain can result secondary to a wide variety of causes, with or without associated pathology, a wide variety of pharmacological classes of drugs are used including a variety of analgesics (ex. opiates, NSAIDs, cannabinoids), antispasmodics (ex. loperamide, benzodiazepines), antidepressants (ex. TCA, SSRI, SNRI) as well as others (ex. ketamine, clonidine, gabapentin). In addition, pharmacotherapy that targets the underlying cause of the pain can help alleviate symptoms due to lessening visceral nociceptive inputs. For example, the use of nitrates can reduce anginal pain by dilating the coronary arteries and thus reducing the ischemia causing the pain. The use of spasmolytics (antispasmodics) can help alleviate pain from a gastrointestinal obstruction by inhibiting the contraction of the gut. There are issues associated with pharmacotherapy that include side effects (ex. constipation associated with opiate use), chemical dependence or addiction, and inadequate pain relief.
Invasive therapies are in general reserved for patients in whom pharmacological and other non-invasive therapies are ineffective. A wide variety of interventions are available and shown to be effective, a few will be discussed here. Approximately 50–80% of pelvic cancer pain patients benefit from nerve blocks. Nerve blocks offer temporary relief and typically involve injection of a nerve bundle with either a local anesthetic, a steroid, or both. Permanent nerve block can be produced by destruction of nerve tissue. Strong evidence from multiple randomized controlled trials support the use of neurolytic celiac plexus block to alleviate pain and reduce opioid consumption in patients with malignant pain originating from abdominal viscera such as the pancreas. Neurostimulation, from a device such as a spinal cord stimulator (SCS), for refractory angina has been shown to be effective in several randomized controlled trials. A SCS may also be used for other chronic pain conditions such as chronic pancreatitis and familial Mediterranean fever. Other devices that have shown benefit in reducing pain include transcutaneous electrical nerve stimulators (TENS), targeted field stimulation, both used for somatic hyperalgesic states, external neuromodulation, pulsed radiofrequency ablation and neuraxial drug delivery systems.
See also
Referred pain
References
Pain
Physiology | Visceral pain | Biology | 1,968 |
27,124,959 | https://en.wikipedia.org/wiki/Sakuma%E2%80%93Hattori%20equation | In physics, the Sakuma–Hattori equation is a mathematical model for predicting the amount of thermal radiation, radiometric flux or radiometric power emitted from a perfect blackbody or received by a thermal radiation detector.
History
The Sakuma–Hattori equation was first proposed by Fumihiro Sakuma, Akira Ono and Susumu Hattori in 1982. In 1996, a study investigated the usefulness of various forms of the Sakuma–Hattori equation. This study showed the Planckian form to provide the best fit for most applications. This study was done for 10 different forms of the Sakuma–Hattori equation containing not more than three fitting variables. In 2008, BIPM CCT-WG5 recommended its use for radiation thermometry measurement uncertainty budgets below 960 °C.
General form
The Sakuma–Hattori equation gives the electromagnetic signal from thermal radiation based on an object's temperature. The signal can be electromagnetic flux or signal produced by a detector measuring this radiation. It has been suggested that below the silver point, a method using the Sakuma–Hattori equation be used. In its general form it looks like
where:
is the scalar coefficient
is the second radiation constant (0.014387752 m⋅K)
is the temperature-dependent effective wavelength (in meters)
is the absolute temperature (in K)
Planckian form
Derivation
The Planckian form is realized by the following substitution:
Making this substitution renders the following the Sakuma–Hattori equation in the Planckian form.
Sakuma–Hattori equation (Planckian form)
Inverse equation
First derivative
Discussion
The Planckian form is recommended for use in calculating uncertainty budgets for radiation thermometry and infrared thermometry. It is also recommended for use in calibration of radiation thermometers below the silver point.
The Planckian form resembles Planck's law.
However the Sakuma–Hattori equation becomes very useful when considering low-temperature, wide-band radiation thermometry. To use Planck's law over a wide spectral band, an integral like the following would have to be considered:
This integral yields an incomplete polylogarithm function, which can make its use very cumbersome.
The standard numerical treatment expands the incomplete integral in a geometric series of the exponential
after substituting Then
provides an approximation if the sum is truncated at some order.
The Sakuma–Hattori equation shown above was found to provide the best curve-fit for interpolation of scales for radiation thermometers among a number of alternatives investigated.
The inverse Sakuma–Hattori function can be used without iterative calculation. This is an additional advantage over integration of Planck's law.
Other forms
The 1996 paper investigated 10 different forms. They are listed in the chart below in order of quality of curve-fit to actual radiometric data.
See also
Stefan–Boltzmann law
Planck's law
Rayleigh–Jeans law
Wien approximation
Wien's displacement law
Kirchhoff's law of thermal radiation
Infrared thermometer
Pyrometer
Thin-filament pyrometry
Thermography
Black body
Thermal radiation
Radiance
Emissivity
ASTM Subcommittee E20.02 on Radiation Thermometry
Notes
References
Statistical mechanics
Equations
1982 in science | Sakuma–Hattori equation | Physics,Mathematics | 677 |
23,951,452 | https://en.wikipedia.org/wiki/Enestebol | Enestebol (), also known as 4-hydroxy-17α-methyl-δ1-testosterone, as well as 4,17β-dihydroxy-17α-methylandrosta-1,4-dien-3-one, is a synthetic and orally active anabolic–androgenic steroid (AAS) and a 17α-alkylated derivative of testosterone which was never marketed. It is closely related to oxymesterone (4-hydroxy-17α-methyltestosterone), as well as to chlorodehydromethyltestosterone (4-chloro-17α-methyl-δ1-testosterone), methylclostebol (4-chloro-17α-methyltestosterone), and metandienone (17α-methyl-δ1-testosterone).
References
Anabolic–androgenic steroids
Androstanes
Enols
Enones
Hepatotoxins | Enestebol | Chemistry | 214 |
6,847,430 | https://en.wikipedia.org/wiki/Sec-Butyllithium | sec-Butyllithium is an organometallic compound with the formula CH3CHLiCH2CH3, abbreviated sec-BuLi or s-BuLi. This chiral organolithium reagent is used as a source of sec-butyl carbanion in organic synthesis.
Synthesis
sec-BuLi can be prepared by the reaction of sec-butyl halides with lithium metal:
Properties
Physical properties
sec-Butyllithium is a colorless viscous liquid. Using mass spectrometry, it was determined that the pure compound has a tetrameric structure. It also exists as tetramers when dissolved in organic solvents such as benzene, cyclohexane or cyclopentane. The cyclopentane solution has been detected with 6Li-NMR spectroscopy to have a hexameric structure at temperatures below −41 °C. In electron-donating solvents such as tetrahydrofuran, there exists an equilibrium between monomeric and dimeric forms.
Chemical properties
The carbon-lithium bond is highly polar, rendering the carbon basic, as in other organolithium reagents. Sec-butyllithium is more basic than the primary organolithium reagent, n-butyllithium. It is also more sterically hindered. sec-BuLi is employed for deprotonations of particularly weak carbon acids where the more conventional reagent n-BuLi is unsatisfactory. It is, however, so basic that its use requires greater care than for n-BuLi. For example diethyl ether is attacked by sec-BuLi at room temperature in minutes, whereas ether solutions of n-BuLi are stable.
The compound decomposes slowly at room temperature and more rapidly at higher temperatures, giving lithium hydride and a mixture of butenes.
Applications
Many transformations involving sec-butyllithium are similar to those involving other organolithium reagents.
In combination with sparteine as a chiral auxiliary, sec-butyllithium is useful in enantioselective deprototonations. It is also effective for lithiation of arenes.
References
Organolithium compounds
Sec-Butyl compounds | Sec-Butyllithium | Chemistry | 472 |
28,916,168 | https://en.wikipedia.org/wiki/Hong%20Kong%20International%20Convention%20for%20the%20safe%20and%20environmentally%20sound%20recycling%20of%20ships | The Hong Kong International Convention for the safe and environmentally sound recycling of ships, or Hong Kong Convention, is a multilateral convention adopted in 2009, which has not entered into force. The conference that created the convention was attended by 63 countries, and overseen by the International Maritime Organization (IMO).
The convention has been designed to improve the health and safety of current ship breaking practices. Ship breaking is considered to be "amongst the most dangerous of occupations, with unacceptably high levels of fatalities, injuries and work-related diseases" by the ILO as large ships are often beached and then dismantled by hand by workers with very little personal protective equipment (PPE). This is most common in Asia, with India, Bangladesh, China, and Pakistan holding the largest ship breaking yards.
The Hong Kong Convention recognised that ship recycling is the most environmentally sound way to dispose of a ship at the end of its life, as most of the ship's materials can be reused. However, it sees current methods as unacceptable. The work sees many injuries and fatalities to workers, as they lack the correct safety equipment to handle the large ship correctly as it is dismantled and most vessels contain a large amount of hazardous materials such as asbestos, PCBs, TBT, and CFCs, which can also lead to highly life-threatening diseases such as mesothelioma and lung cancer.
In advance of ratification of the Hong Kong Convention, the Industry Working Group on Ship Recycling issued Guidelines on Transitional Measures for Shipowners Selling Ships for Recycling.
Inventory of Hazardous Materials
The Inventory of Hazardous Materials has been designed to try to minimise the dangers of these hazards. The Convention defines a hazard as: “any material or substance which is liable to create hazards to human health and/or the environment".
All vessels over 500 gross tons (GT) have to comply with the convention once it comes into force. Each party that does wish to comply must restrict the use of hazardous materials on all ships that fly the flag of that party.
New ships must all carry an Inventory of Hazardous Materials. The inventory will list all 'hazardous materials' on board the vessel, including their amounts and locations. Existing ships must comply no later than five years after the convention comes into force, or prior to being recycled if this occurs before the five-year period. The inventory will remain with a vessel throughout its lifespan, being updated as all new installations enter the ship, as these may potentially contain hazards. The presence of the inventory will then ensure the safety of crew members during the vessel's working life, and also the safety of workers during the recycling process.
Signature, ratification and accession
The convention was open for signature between 1 September 2009 and 31 August 2010, and remained open for accession afterwards. It will enter into force two years after "15 states, representing 40% of the world merchant shipping by gross tonnage, and on average 3% of recycling tonnage for the previous 10 years, have either signed it without reservation as to ratification, acceptance or approval, or have deposited instruments of ratification, acceptance, approval or accession with the Secretary General". The convention will enter into force on 26 June 2025.
Transitional Guidelines
In advance of ratification of the Hong Kong Convention, the Industry Working Group on Ship Recycling in 2009 issued the first edition of Guidelines on Transitional Measures for Shipowners Selling Ships for Recycling. These are supported by maritime organizations: International Chamber of Shipping (ICS), the Baltic and International Maritime Council (BIMCO), the International Association of Classification Societies (IACS), Intercargo, the International Parcel Tankers Association (IPTA), Intertanko, the Oil Companies International Marine Forum (OCIMF), and the International Transport Workers' Federation (ITF). The Transitional Measures are also supported by the national shipowners' associations of Australia, Bahamas, Belgium,
Canada, Chile, Cyprus, Denmark, Faroe Islands, Finland, France, Germany, Greece, Hong Kong, India, Ireland, Italy, Japan, Korea, Kuwait, Liberia, Mexico, Netherlands, Norway, Portugal, Philippines, Russia, Singapore, Spain, Sweden, Switzerland, Turkey, United Kingdom and United States.
Relation to EU instruments
The EU Ship Recycling Regulation entered into force on 30 December 2013. Although this regulation closely follows the Hong Kong convention, there are important differences. The Regulation sets out a number of requirements for European ships, European ship owners, ship recycling facilities willing to recycle European ships, and the relevant competent authorities or administrations. The argument for developing a specified regulation for ship recycling in the European Union, was the fact that the EU noticed how many EU ships that ended up in unsustainable recycling facilities. Europeans own around 40% of the world fleet, around 15000 ships. Among these around 10000 fly an EU Member-State flag, but only 7% of the EU-flagged ships are dismantled in the EU territory, and the rest are mostly dismantled in South Asia
The SRR aims to address the environmental and health hazards associated with ship dismantling by setting high standards for EU-flagged vessels at the end of their operational lives. One of the key components developed by the EU is the European List of Approved Ship Recycling Facilities, identifying the approved ports for all EU flagged ships to be recycled. For a ship recycling yard to be included in the list, the facilities must comply with strict environmental and worker safety standards, reducing toxic waste release and promoting safe dismantling practices. Member States report to the Commission on which facilities in their territory that comply to the requirements, and thereby get included on the list. Shipyards outside the EU can also be included on the European List but must apply to the Commission with proof of the yard’s standards.
To be included on the European List, ship recycling facilities must adhere to specific requirements set by the EU and aligned with the Hong Kong Convention and other international guidelines. Facilities need authorization, robust structural and operational standards, environmental safety protocols, and measures for monitoring health and safety risks to workers and nearby populations. This includes handling hazardous materials on impermeable surfaces, training workers and provide them with protective equipment, implementing emergency plans, and recording incidents. Operators must also submit recycling plans and completion reports, ensuring full compliance and minimizing environmental and health impacts during ship recycling activities. As of November 2024, it contains of 45 shipyards. Because the list works as a guarantee for an yards safety and validity, shipyards can both be removed and added to the list if they seize to comply to the regulation.
Additionally, to the list of approved facilities, the SRR also mandates each ship to hold an Inventory of Hazardous Materials (IHM), listing hazardous substances used in each ship's construction. By hazardous material’ means any material or substance which is liable to create hazards to human health and/or the environment. New installation of material such as asbestos and ozone-depleting substances are prohibited, and the occurrence of materials containing lead, mercury and radioactive substances, to name a few, are to be reported and restricted. This inventory, which must be maintained throughout the ship's life, helps guide shipyards and recyclers on safe waste management and reduces accidental environmental contamination. The ships also report on the operationally generated waste, meaning wastewater and residues generated by the normal operation of ships. By EU standards, any EU ship going for dismantling, all new European ships, and third-country ships stopping in EU ports need to have an inventory of hazardous materials on board
This list, as of 27 July 2023, contains 48 ship-recycling facilities, including 38 yards in Europe (EU, Norway and UK), 9 yards in Turkey and 1 yard in the USA. Several yards on the European List are also capable of recycling large vessels. The list excluded some of the most major ship recycling yards in India and Bangladesh, which have achieved SoCs with the HKC in various class societies. This exclusion has led to many ship owners changing the flag of their vessel before recycling or sell the ship to cash buyers, to evade the regulations. Excluded countries strive towards bringing the HKC into force as the universal regulation, arguing that it would be irrational if international shipping were regulated by multiple and competing standards.
The SRR does however come in conflict with other laws of the sea. When a ship receives a recycling certificate under the Hong Kong Convention, it may also be classified as hazardous waste under the Basel Convention. Throughout the certificate's validity, which can last up to three months, the ship's owners may face the risk of arrest in some ports for violating the Basel Convention. Trough the EUs Waste Shipment Regulations they intend to implement the same rules as the Basel Convention (WSR). However, when implementing the SRR, the EU opted to unilaterally exclude EU-flagged vessels from the scope of the existing WSR. This decision effectively created an unauthorized exemption from the Basel Regime for certain types of hazardous waste, lacking sufficient justification.
References
Environmental conferences
Hazardous materials
2009 in Hong Kong
Treaties concluded in 2009
Treaties not entered into force
Treaties of Belgium
Treaties of the Republic of the Congo
Treaties of Croatia
Treaties of Denmark
Treaties of Estonia
Treaties of France
Treaties of Germany
Treaties of Ghana
Treaties of India
Treaties of Japan
Treaties of Malta
Treaties of the Netherlands
Treaties extended to the Caribbean Netherlands
Treaties of Norway
Treaties of Panama
Treaties of Serbia
Treaties of Turkey | Hong Kong International Convention for the safe and environmentally sound recycling of ships | Physics,Chemistry,Technology | 1,901 |
14,212,068 | https://en.wikipedia.org/wiki/Mercury%28IV%29%20fluoride | Mercury(IV) fluoride, HgF4, is a purported compound, the first to be reported with mercury in the +4 oxidation state. Mercury, like the other group 12 elements (cadmium and zinc), has an s2d10 electron configuration and generally only forms bonds involving its 6s orbital. This means that the highest oxidation state mercury normally attains is +2, and for this reason it is sometimes considered a post-transition metal instead of a transition metal. HgF4 was first reported from experiments in 2007, but its existence remains disputed; experiments conducted in 2008 could not replicate the compound.
History
Speculation about higher oxidation states for mercury had existed since the 1970s, and theoretical calculations in the 1990s predicted that it should be stable in the gas phase, with a square-planar geometry consistent with a formal d8 configuration. However, experimental proof remained elusive until 2007, when HgF4 was first prepared using solid neon and argon for matrix isolation at a temperature of 4 K. The compound was detected using infrared spectroscopy.
However, the compound's synthesis has not been replicated in other labs, and more recent theoretical studies cast doubt on the possible existence of mercury(IV) (and copernicium(IV)) fluoride. Dirac-Hartree-Fock computations including both relativistic effects and electron correlation suggest that an HgF4 compound would be unbound by about 2 eV (and CnF4 by 14 eV).
Explanation
Theoretical studies suggest that mercury is unique among the natural elements of group 12 in forming a tetrafluoride, and attribute this observation to relativistic effects. According to calculations, the tetrafluorides of the "less relativistic" elements cadmium and zinc are unstable and eliminate a fluorine molecule, F2, to form the metal difluoride complex. On the other hand, the tetrafluoride of the "more relativistic" synthetic element 112, copernicium, is predicted to be more stable.
Subsequent density functional theory and coupled cluster calculations indicated that bonding in HgF4 (if it really exists) involves d orbitals. This has led to the suggestion that mercury should be considered a transition metal (the group 12 metals are sometimes excluded from the transition metals because they do not oxidize beyond +2). Chemical historian William B. Jensen has argued that the compound alone is insufficient to reclassify the metal, because HgF4 represents at best a non-equilibrium transient state.
Synthesis and properties
HgF4 is produced by the reaction of elemental mercury with fluorine:
Hg + 2 F2 → HgF4
HgF4 is only stable in matrix isolation at ; upon heating, or if the HgF4 molecules touch each other, it decomposes to mercury(II) fluoride and fluorine:
HgF4 → HgF2 + F2
HgF4 is a diamagnetic, square planar molecule. The mercury atom has a formal 6s25d86p6 electron configuration, and as such obeys the octet rule but not the 18-electron rule. HgF4 is isoelectronic with the tetrafluoroaurate anion, , and is valence isoelectronic with the tetrachloroaurate (), tetrabromoaurate (), and tetrachloroplatinate () anions.
References
Mercury compounds
Fluorides
Metal halides
Hypothetical chemical compounds
Substances discovered in the 2000s | Mercury(IV) fluoride | Chemistry | 734 |
37,217,735 | https://en.wikipedia.org/wiki/Women%27s%20oversized%20fashion%20in%20the%20United%20States%20since%20the%201920s | Oversized fashion, distinct from plus-sized fashion, consists of clothing and other accessories that are larger than normal and reflect some sort of attitude, message, or trend of the period at hand. While oversized fashion trends from the 1920s to the turn of the century vary from decade to decade, there are many overarching themes that have been expressed during the past one hundred or so years. Masculinity, for example, has played a large role in many of the underlying communications of the fashions, although virility is manifested differently in the clothing depending on the era. Oversized fashion production, furthermore, runs largely parallel with the states of the American and global economies. Modernly, oversized fashion has taken on a new form - primarily in the realm of oversized accessories.
The 1920s
The 1920s were marked by a post-war aesthetic. After World War I, the fashion world experienced a great switch: from tight corsets and hobble skirts—to shapeless, oversized, and sparsely decorated garments. Women began to wear more comfortable fashions, including blousy skirts and trousers. Further, this era gave birth to sportswear fashion. Sportswear, previously recognized as America's main contribution to fashion, consisted of a casual more relaxed style. Coco Chanel, known as the first modern dressmaker, made one of the greatest contributions to style in the 1920s: the two-piece dress. She created two-piece dresses out of jersey (fabric), a comfortable stretchy fabric. The American public was receptive, embracing this relaxed style, which was perfect for the active woman on the go. The combination of these new ideas yielded this loosely fitted, modernized style.
The "boyish figure", moreover, became a prevalent trends of the era, with shapeless silhouettes and dropped waistlines giving a more masculine look to the female figure. The emphasis on a flattened chest revolutionized the construction of undergarments. Along with this new silhouette, 1920s fashions were further modernized by the coming of a new generation of sewing-machines, each with an individual electric motor, enabling designers to create more oversized fashions, while saving time and resources.
In contrast to the "boyish figure" were the types of hats and accessories women wore in the roaring twenties. Flapper dresses were juxtaposed with oversized hats, often trimmed with large bows, feathers, ribbons, or sequins. Furthermore, bold headbands were often worn to complement women's customarily shorter hair lengths. Since a lot of women's fashion from this decade were quite masculine in style, many women adorned them with accessories that were rather feminine.
Music also had an influence in the ways in which fashions evolved. The Jazz Age saw the popularization of flaps in dresses; and stars such as the entertainer Josephine Baker became known for their semi-translucent flapper frocks.
The 1930s
The 1930s started in depression and ended with the onset of World War II. With rising unemployment and despair, no industry was left unaffected. In the fashion industry, designers cut their prices and produced new lines of ready-to-wear clothes, along with clothing made of more economical and washable fabrics, such as rayon and nylon. For example, Coco Chanel showed a collection of evening dresses made of cotton and sold dresses reduced by 50%. The fashions of the 1930s were stylish and elegant, with flowing lines and Paris-based coutures.
Since many women could not afford to update their wardrobes, women changed their look by resorting to alterations to exemplify the oversized fashion of the 1930s. They used lengthening bands of contrasting fabric and added fur to their hems. This inventive way to put together new articles of clothing gave birth to the "Feedsack Dress"; constructed from the material of a sack of animal feed, these frocks were typically cut similarly to shift dresses. This A-line cuts were boxy and contrasted the slinky and sensual bias-cut dresses that became famous during the same era for their ability to cover the woman's body while clinging to each curve. Furthermore, material was added to collars and sleeves. Another trend rising from the 1930s was the "Banjo Sleeve", created by sewing two rectangular pieces of fabric with the top seam only sewn halfway to allow the arm to flow out. The boxy shape was oversized and blousy. As the era progressed, skirts that flared out fell to the bottom of the calf and sleeves were loosely tied as they fell from the elbow to wrist.
From the harsh economic conditions of the time came about the glamorous 1930s in film, and the glamorous clothing worn seen on the screen grew in popularity. Dresses constructed from Chiffon fabric were rather loose-fitting as they flew away from the body, and embodied the elegance that was maintained throughout the 1930s despite the economic struggles.
The 1940s
During the first half of the 1940s, many clothing-related commodities were in short supply due to World War II; the United States Government relinquished numerous products for utilization in warfare. Leather, for example, was much used in the uniforms of American servicemen—so the material, to a large extent, went out of use in mainstream fashion. As a consequence, oversized fashion utilizing excessive amounts of material was not in style.
Designers such as Cristóbal Balenciaga, Digby Morton, and Norman Hartnell, however, utilized oversized fashion practices in their early 1940s collections to manifest the consequential happenings of the war. While men were abroad taking up arms, many women took on their positions in factories and offices. Accordingly, women's fashion became more masculine. Wide-legged slacks and pronounced shoulder pads became all the rage, and most American women embraced the virile style.
Not until the second half of the decade, though, with the introduction of Dior's “New Look,” was oversized fashion widely put to use. Dior's “New Look,” which first grew in popularity in Europe, featured full skirts that reached the mid-calves. When Dior initially set in motion this new style, the fashion house received a lot of criticism. Sir Stafford Cripps, then President of the Britain's Board of Trade, was quoted as saying that the “New Look” was “utterly stupid” and an enormous waste of labor and materials. He was not the only one opposed to the excessive usage of material. In the U.S, legislation was passed that restricted yardage in fabric for clothing, under a policy entitled L-85.
Many American citizens resisted the new legislation, with groups being formed such as the “A Little Below the Knee Club” in Texas. However, in the U.S, Dior's "New Look" was also shaping the trends of the time. Designer Claire McCardell, influenced by Parisian design, created the monastic dress, in jersey, featuring a criss-cross string belt at midriff and a draped full skirt. A few years later, however, once World War II ended, the “New Look” and its oversized flair was relished both within the fashion world and the consumer market.
The 1950s
The post-war era of the 1950s brought a change to the family dynamic as well as to the fashion world. In 1947, Christian Dior launched as the first collection from his fashion house his "Corelle line", which featured oversized designs. The "Corelle line" became the look of the decade, ushering femininity, luxury and grace into the era, and making a great impact on the female silhouette. This change implemented by Christian Dior dominated the decade.
Clothes transformed from boxy styles, with square shoulders, to feminine and luxurious, with soft shoulder lines, corseted waists, round padded hips, and long skirts, leading to the knee-length "sack" dress. The knee-length skirts and dresses were the most oversized items of this 1950s. The introduction of new fabrics, including Terylene, Orlon, Banlon, Acrilan and Poplin, allowed for new fashion styles to be both created and introduced. Among these were the "wash-and-wear" sweater, the permanently pleated skirt, and the "drip-dry" skirt. Skirts of this era known as circle skirts were supported by layers of petticoats, creating a circular look that accentuated the waist line. Essentially, the petticoat reinforced the femininity of this period.
The 1950s woman also tended to be influenced by the fashions worn by movie stars such as Marilyn Monroe and Audrey Hepburn. Hepburn in her roles in various movies such as Roman Holiday famously wore an oversized skirt that accentuated her waist, together with a tighter shirt.
The 1960s
The look of the 1960s was in marked contrast to the “New Look” developed in the end of the 1940s that heavily influenced trends of the 1950s with femininity and sensuality. The look of the 1960s reflected the main issue of that time: Civil Rights. The 1960s woman “demanded equal rights and equal pay, wanted to be free, to look young and to have fun”. Oversized fashions were utilized in more subtle ways in this decade, giving rise to trends that revolutionized the working woman and gave a voice to more conservative feminines.
To achieve this youthful and flirty look, skirts were shortened, creating a look reminiscent of the 1920s. During this era, in 1965, the miniskirt was developed. An alternative to this exposed look was in high demand, thus leading to the creation of the midi skirt. This new "midi" mainly featured a pleated A-line bodice, which allowed it to flow away from the body. This oversized fashion began to make its way to the workplace as it provided both femininity and formality. Evening wear was also affected, and both long and short dresses could be seen at engagements. Designs embraced the oversized look through more elegant silhouettes, specially in evening wear, which boasted loose forms and fluid fabrics. The change in fashion during this period was also due to international influences such as from London and France, where designers were young. A notable point about this period is that women also began to wear pants-suits and jeans.
The materials used for both clothing and accessories changed during this era. Increasingly used were easy-care synthetic fabrics such as Crimplene, Dacron and Terylene. The benefits of such synthetic fabrics were that they were crease-resistant, easy to wash, and required little to no ironing. Designers such as Cristóbal Balenciaga embraced these new types of materials, using them in oversized dolman-sleeve jackets. The pattern for this piece was cut in a rectangular shape forming a boxy blousy look.
During this period, synthetic yarns that took dyes easily were used. Leather-look plastic also helped to create a vibrant feel to accessories such as shoes, umbrellas and additional clothing items such as mini-skirts. While in this era, clothing became split along lines of age, there were overriding oversized trends including: midi skirts, Dolman sleeves, loose jackets and shapeless frocks. Another factor contributing to the trends of this period was the “post-industrial boom” that helped to generate wealth in the United States. Jackie Kennedy, wife of President John F. Kennedy, became a model of French fashions and helped to spur the spread of the miniskirt, along with Twiggy, who gained iconic status as the face and body of the era wearing the shapeless mod dresses that were a huge trend. Jackie Kennedy's “beehive” hairstyle also highlighted oversized fashion.
The 1970s
The 1970s is often referred to as the “Me Decade”, a term originally coined by writer Tom Wolfe. There were many groups, such as political and extremist groups, wanting a piece of the action. With respect to dress, it was an “anything goes” era, without rules. This manifested in some ways via the production of oversized fashion.
Fashion styles were inspired by previous decades, hinting at both nostalgia and an interest in other cultures. The current political and economic situation of the United States, including the civil rights, unemployment levels, war and terrorism, were reflected in the manner in which individuals dressed. With the women's movement of the 1970s, radical feminists could be stereotyped for their anti-high fashion sentiments; these women required low maintenance and made a statement. With regards to high fashion, established fashion houses produced more ready-to-wear collections and casual attire.
With nostalgia a big theme of this period, secondhand clothes were key. Similar to the 1950s, 1920s clothing also influenced this decade, along with fashions of the '30s, '40s and '50s. Television and movies such as The Godfather and Grease also played homage to styles of the past. When not inspired by nostalgia, fashion took another turn whereby "the idea was to appear as if your body had been spray painted". To achieve this look, leotards were worn and were accessorized with short frilled skirts, cap sleeves and leg-warmers. “Hot pants” or skimpy shorts were also popular in the beginning of the '70s. By the mid-1970s, we see the reemergence of “unstructured design” from the fashion houses. These were considered the simplest cuts, appearing to look as if no skilled cutting was required. Typical of this cut is Issey Miyake’s wool cowboy look for winter 1978-79, an example of experimentation in textured knitting. The unstructured design of the 1970s highlights the oversized fashion of the decade.
The 1980s
The beginning of the 1980s was the first time when women assumed high-status roles in the workplace. Akin to the 1940s, women's fashion in the 1980s was quite masculine, which was a reflection of women wanting to be taken seriously as working professionals. The three most important designers at the start of this decade, Calvin Klein, Giorgio Armani, and Ralph Lauren, were designing clothing that was characterized by broad and square shoulders. This use of oversized shoulders was largely a demonstration of women not wanting to be viewed by their feminine figures, but rather to be viewed equally in their careers.
Designers such as Rei Kawakubo of Comme des Garçons and Yohji Yamamoto began designing with a Japanese-inspired aesthetics. Clothing became much more oversized to better resemble kimono and other flowing Japanese garments. As with oversized shoulders, this Japanese style had the effect of disguising the womanly shape. Donna Karan, who became known at the time as "the Queen of 7th Avenue,", also began utilizing this Japanese style of dress.
Figures both within and outside the fashion world took on this gender-neutral style and made the look ever more popular. Singer, actress, and model Grace Jones was a key figure in furthering this type of fashion—keeping her hair short and wearing manly, oversized clothing. Scottish singer Annie Lennox did the same, but had much more of an effect in the musical realm.
Another essential person who helped further the style of oversized fashion in the 1980s was Princess Diana, who for her wedding to Charles, Prince of Wales in July 1981 wore an oversized wedding dress—making the tailor popular all around the world for the remainder of the decade.
The 1990s
The 1990s was one of the most diverse eras for fashion. As the fashion world began to experience technological modernization, along with a widespread support from mainstream consumers, the industry felt the need to appeal to different types of audiences. Some of the women's fashion trends included neon and pastel colors, legging and exercise wear, the hippie look, and a hip-hop style. The last of those examples, hip-hop style, is identifiable as the oversized fashion of the '90s. The influence of hip-hop on urban fashion was overtly strong. Urban fashion was distinctly designed for African-American youth.
The 1990s urban style heavily influenced by Black Nationalism and African trends began with the blousy pant sported by famous figures in the rap world such as MC Hammer, who popularized oversized "Hammer pants", and fezzes. However, men were not the only ones to embrace this new form of street wear. Women too began to explore the trend. The group TLC (band) and R&B singer Aaliyah created their own urban fashion for women. The trend consisted of wearing oversized pants and big flannel shirts. The hardcore aspect of rap did not fully permit the women to embrace a feminine look that might make them appear weaker. However, some femininity was maintained by the wearing of more fitted shirts, bare midsections and sports bras, while still being hard with the blousy pieces.
During the upheaval of the streetwear fashion, models of color began to make their mark in the industry. It was during the 1990s that Tyra Banks found fame. After being rejected by six modeling agency the young Banks was signed by Elite Model Management, and in her first season as a model she booked 25 shows in Paris Fashion Week. Banks' seductive walk impressed designers and made her a hot commodity. Designers who were influenced by the new oversized streetwear were more likely to book models of color to show their designs. Other famous models of color during the time include Naomi Campbell and Iman. Undoubtedly, oversized fashion marked the beginning of a new trend for urban youth during the 1990s.
The 2000s
Women's oversized fashion at the turn of the century is largely displayed in various accessories. At the beginning of the 2000s, many designers began using sizable and bulky glasses and jewelry in their lines, and women in the spheres of fashion, music, and film began wearing these oversized decorations. Celebrities such as Nicole Richie and Rachel Zoe helped to further this wearing of oversized accessories, and assisted in making the items popular in everyday wear. As the decade progressed, the utility of oversized accessories did not wane, but rather became even more widely used.
Since the year 2006, three designers have garnered massive amounts of attention for their adoption of oversized fashion: Stella McCartney, Alexander McQueen, and Marc Jacobs. In 2006, McQueen put on a show in which an enormous Pepper's ghost illusion of Kate Moss dressed in yards of rippling fabric adorned the backdrop of catwalk; this move furthered the attention of oversized fashion and made Moss the poster model for oversized styling. The death of McQueen in February 2010 led to his style of fashion accruing even more attention, which put oversized fashion even more on the map.
Another exhibition of the trend is the oversized handbag. Designers such as Balenciaga, Betsey Johnson, and Michael Kors began producing purses and satchel-like bags that were larger than usual and complied with the oversized aesthetic. As a result of the enormous increase in influence of the internet and social media, these bags quickly became very popular after pictures of celebrities carrying them were posted online for many to see and then emulate.
The reviews of oversized fashion use in the new millennium have been mixed. Some designers and critics have welcomed the utilization of oversized accessories, while others view the trend as prodigal. Young designers and fashion houses such as McCartney, McQueen, and Jacobs generally esteem oversized accessories, while older and more established couturiers such as Chanel find much oversized accessories distasteful and extravagant.
See also
References
1920s fashion
1920s in the United States
Sizes in clothing
Flappers
Women's clothing | Women's oversized fashion in the United States since the 1920s | Physics,Mathematics | 3,962 |
2,612,812 | https://en.wikipedia.org/wiki/CNDO/2 | Complete Neglect of Differential Overlap (CNDO) is one of the first semi empirical methods in quantum chemistry. It uses the core approximation, in which only the outer valence electrons are explicitly included, and the approximation of zero-differential overlap.
CNDO/2 is the main version of CNDO. The method was first introduced by John Pople and collaborators.
Background
An earlier method was Extended Hückel method, which explicitly ignores electron-electron repulsion terms. It was a method for calculating the electronic energy and the molecular orbitals. CNDO/1 and CNDO/2 were developed from this method by explicitly including the electron-electron repulsion terms, but neglecting many of them, approximating some of them and fitting others to experimental data from spectroscopy.
Methodology
Quantum mechanics provides equations based on the Hartree–Fock method and the Roothaan equations that CNDO uses to model atoms and their locations. These equations are solved iteratively to the point where the results do not vary significantly between two iterations. CNDO does not involve knowledge about chemical bonds but instead uses knowledge about quantum wavefunctions.
CNDO can be used for both closed shell molecules, where the electrons are fully paired in molecular orbitals and open shell molecules, which are radicals with unpaired electrons. It is also used in solid state and nanostructures calculations.
CNDO is considered to yield good results for partial atomic charges and molecular dipole moment. Total energy and binding energy are calculated. Eigenvalues for calculating the highest occupied molecular orbital and lowest unoccupied molecular orbital are reported from the closed shell approach.
See also
Molecular geometry
INDO
NDDO
References
External links
CNDO/2 Calculation (Pirika)
Molecular Modeling for Educators
Density Functional Modelling of Point Defects in Semiconductors
Semiempirical quantum chemistry methods | CNDO/2 | Chemistry | 373 |
23,922,168 | https://en.wikipedia.org/wiki/Telepresence%20technology | Telepresence technology is a term used by the National Oceanic and Atmospheric Administration (NOAA) to refer to the combination of satellite technology with the Internet to broadcast information, including video in real-time from cameras used on its remotely operated vehicle (ROV) on Okeanos Explorer. Its ROV will be operating working in a deep sea environment. Data from the ROV is transmitted to a hub based on the land, which then send it to scientists and to the public.
This effort of the Okeanos Explorer has been compared to the lunar landing.
The telepresence technology used by NOAA includes the following:
deep water mapping, to a depth of 6,000 m
science-oriented ROV operations
real-time satellite transmission of data.
The Okeanos Explorer is designed as an educational tool that can be followed on Twitter.
Notes
Educational technology
Oceanography
Telepresence | Telepresence technology | Physics,Environmental_science | 183 |
27,005,434 | https://en.wikipedia.org/wiki/Stochastic%20roadmap%20simulation | For robot control, Stochastic roadmap simulation is inspired by probabilistic roadmap methods (PRM) developed for robot motion planning.
The main idea of these methods is to capture the connectivity of a geometrically complex high-dimensional space by constructing a graph of local paths connecting points randomly sampled from that space. A roadmap G = (V,E) is a directed graph. Each vertex v is a randomly sampled conformation in C. Each (directed) edge from vertex vi to vertex vj carries a weight Pij , which represents the probability that the molecule will move to conformation vj , given that it is currently at vi. The probability Pij is 0 if there is no edge from vi to vj. Otherwise, it depends on the energy difference between conformations.
Stochastic roadmap simulation is used to explore the kinetics of molecular motion by simultaneously examining multiple pathways in the roadmap. Ensemble properties of molecular motion (e.g., probability of folding (PFold), escape time in ligand-protein binding) is computed efficiently and accurately with stochastic roadmap simulation. PFold values are computed using the first step analysis of Markov chain theory.
See also
Jean-Claude Latombe
Mark Overmars
References
Robot control
Stochastic simulation | Stochastic roadmap simulation | Engineering | 271 |
20,842,572 | https://en.wikipedia.org/wiki/Acrylic%20rubber | Acrylic rubber, known by the chemical name alkyl acrylate copolymer (ACM) or the tradename HyTemp, is a type of rubber that has outstanding resistance to hot oil and oxidation. It belongs to specialty rubbers. It has a continuous working temperature of and an intermittent limit of . ACM is polar and lacks unsaturation. It is resistant to ozone and has low permeability to gases.
Its disadvantage is its low resistance to moisture, acids, and bases. It should not be used in temperatures below .
It is commonly used in automotive transmissions and hoses. It is also used in shaft seals, adhesives, beltings, gaskets and O-rings. It is used in vibration damping mounts due to the damping properties.
See also
Copolymer
References
Rubber
Elastomers | Acrylic rubber | Physics,Chemistry | 177 |
60,758,754 | https://en.wikipedia.org/wiki/Coral%20Reef%20Conservation%20Program | Coral Reef Conservation Program (CRCP) is a partnership between National Oceanic and Atmospheric Administration (NOAA) agencies, established in 2000. The program is a multidisciplinary approach, initiated by the NOAA, to managing and understanding coral reef ecosystems through research and the publication of data to support relevant partners involved in coral reef restoration.
Background
The CRCP was established by the Coral Reef Conservation Act 2000 and Presidential Executive Order 13089, in order to fulfil the NOAA's obligations under these statutes.
The main role of the CRCP is to gather and present scientific information that coastal and marine resource managers and other decision-makers require, to address the various threats facing coral reef ecosystems in U.S. and surrounding waters. The CRCP's priority threats are climate change, unsustainable fishing practices and pollution. Monitoring the effects of these threats on the condition of U.S. coral reef ecosystems is the primary responsibility of the CRCP. Each year NOAA divers survey coral reefs at nearly 1600 sites to monitor these effects.
All research and data collected by the CRCP is publicly available on the Coral Reef Information System. Other than ecosystem monitoring, other tasks conducted by the CRCP include mapping of coral reef habitats, forecasting oceanographic conditions, and communications and data management.
As well as conducting research, the CRCP also financially supports a number of partners including institutions of higher education and not-for-profit organisations, by awarding grants to projects involved in coral reef ecosystem management and restoration. The program aims to fund at least $8 million in grants each year to partners involved in coral reef conservation management projects. In the 2018 Fiscal Year, the program contributed more than $26 million in funding towards coral reef projects across the U.S, through grants and agreements. Funding for the CRCP is provided by the NOAA and the U.S. Fish and Wildlife Service.
Agencies Involved
The CRCP is made up of several NOAA Line Offices including the National Ocean Service, the National Marine Fisheries Service, the Office of Oceanic and Atmospheric Research, and the National Environmental Satellite, Data and Information Service.
The National Ocean Service is the NOAA partner that is responsible for overseeing budget activities for the CRCP and other NOAA agencies. The National Ocean Service also conducts a number of partnered activities with the CRCP including mapping and monitoring of coral reef ecosystems.
The National Marine Fisheries Service is an agency focused on reducing and controlling the effects of overfishing, and works closely with the CRCP to manage the effects of overfishing on coral reef ecosystems
The National Environmental Satellite, Data and Information Service is another NOAA agency whose main role is to monitor coral reef indices through sensors. This data is shared with NOAA bodies including the CRCP, which is then applied to management decision making.
NOAA's Oceanic and Atmospheric Research body coordinates data collection relating to atmospheric and oceanic parameters such as climate variability and wave movement. Oceanic and Atmospheric Research is another partner of the CRCP, providing the organisation with data.
The CRCP also works closely with a number of external partners including state and territorial governments, academic institutions and non-government and intergovernmental organisations.
Objectives
The mission of the Coral Reef Conservation Program is outlined in the Coral Reef Conservation Act and can be summarised as to "protect, conserve and restore coral reef resources by maintaining healthy ecosystem functioning". The objectives of the program are consolidated into the following four key pillars, as outlined in the NOAA governmental webpage.
Increasing Resilience to Climate Change
The CRCP has adopted a resilience-based approach to addressing the issue of climate change which poses a significant threat to coral reef ecosystems by instigating coral bleaching. A resilience-based approach involves increasing the capacity of coral reef ecosystems to recover from changes in parameters and continue normal functioning. Resilience based management utilises pro-active responses rather than reactive responses that traditional management strategies tend to adopt. The CRCP's main responsibility under this approach is to continue to conduct and provide partners with the relevant information and data necessary to successfully initiate resilience-based management practices. In 2014, CRCP scientists, along with partners including the NOAA Coral Reef Watch, developed precise climate and bleaching thermal stress prediction tools. By anticipating stress events such as global bleaching outbreaks, managers can make proactive decisions to minimise the overall effects on coral reef ecosystems. One of the CRCP's targets is for at least seven of the organisation's partners to apply such climate resilience related data to climate-change orientated projects, by 2025. The CRCP also has the responsibility of initiating ongoing communication with government bodies and federal management partners on the importance of resilience-based management for the future viability of coral reefs. To fulfil this responsibility, the CRCP has developed communication plans and response plans to present information and data in a systematic and coherent manner for federal decision and policy makers. Crisis response plans are made up of early warning frameworks to prepare and protect ecosystems in response to global threat events such as coral bleaching, disease and invasive species outbreaks, and natural weather disasters such as tropical storms.
Reducing Land-based Sources of Pollution
Land-based sources of pollution pose a significant threat on coral reef ecosystems by interrupting natural processes and functioning. Reducing this threat is another pillar under the objectives of the CRCP. The CRCP regulates and supports a number of watershed management initiatives including research to identify sources of pollution, conducting studies to understand the impacts of land-based sources of pollution on coral reefs and providing financial and technical assistance to partners' watershed management responses. A key partnership under this pillar is the 'Watershed Partnership Initiative' with the U.S Coral Reef Task Force, which focuses on reducing land-based pollutants by implementing specific and integrated action responses. Watershed management includes the implementation of vegetated buffer protection along coasts, land conservation and the responsible treatment of wastewater.
Improving Fisheries' Sustainability
The success of the CRCP's ability to improve the sustainability of U.S. fisheries relies heavily on partnerships with relevant fishery management councils and agencies. There are two key strategies under this pillar, both of which involve cooperating with external partners. One of the strategies is to provide key data for coral reef fisheries management. Data collected by the CRCP is used by a number of fisheries managers working under the Magnuson-Stevens Fishery Conservation and Management Act in order to ensure that the ecological role and function that marine species play in coral reef ecosystems is sustained. The second strategy is to assist partner agencies in effectively managing coral reef fisheries. The CRCP aims for 50 percent of relevant partners to adopt effective management tools of which have been developed cooperatively. One way that the CRCP assists federal partners interested in the sustainable management of fisheries, is by supporting effective implementation and management of marine protected areas. Marine protected areas are valuable tools for restoring overexploited ecosystems and protecting fisheries.
Restoring Viable Coral Populations
The final pillar to the CRCP's strategy plan is the restoration of coral reef ecosystems. This involves supporting research of herbivore replenishment processes and collecting further data to support the prevention of avoidable losses of coral, increasing resilience and improving long-term coral health. In order to successfully enhance resilience the CRCP has recognised the need to conduct restoration projects on an international level by continuing to build foreign partnership. Restoration projects include resilience interventions such as assisted genetic adaptation, the manipulation of symbiotic relationships and larval propagation.
Projects and Initiatives
Status reports
One of the CRCP's most significant contributions to the management of U.S. coral reef ecosystems is the development of a periodic, national-level assessment on the condition of U.S. coral reef areas. The CRCP partnered with the Integration and Application Network (IAN) at the University of Maryland Centre for Environmental Science (UMES) in forming 'status reports' to present the data collected from the periodic assessments. The status reports fulfil one of the CRCP's responsibilities, as mandated by the Coral Reef Conservation Act 2000, to build an 'integrated observing system' to monitor the condition of coral reefs over time.
Both biological and physical data is collected by UMES-IAN and NOAA scientists in coral reef areas including: American Samoa, the Commonwealth of the Northern Marianna Islands, Guam, Hawaiian Archipelago, and the Pacific Remote Islands. The status reports include the assessment of several indicators which are synthesised into overall condition scores. The indicators are based on four main categories: coral and algae, fish, climate and human connections.
The purpose of the reports is to establish both a baseline and a record to track changes overtime and evaluate the overall conditions of the U.S. coral reef ecosystems. The reports are also part of CRCP's larger initiative to communicate complex information in a clear and concise manner in order to inform communities and decision-makers.
Coral Reef Information System (CoRIS)
The CRCP operates an information database known as 'CoRIS', that provides public access to all coral reef data and information collected and managed by the NOAA. This information portal is a key function of the CRCP, making data accessible to all coral reef management decision-makers. CoRIS is made up of a number of databases including the 'NOAA Deep Sea Coral Data Portal', which provides access to data relating to deep sea coral and sponges.
Outreach and education activities
One of the CRCP's responsibilities as outlined in the Coral Reef Conservation Act is to build public awareness and knowledge on the importance of sustainable management of coral reefs. The CRCP has conducted a number of educational and training workshops, and has also distributed a range of educational material regarding coral reef management, to the public.
In 2017, the CRCP developed an educational video named "A Guide to Assessing Coral Reef Resilience for Decision Support". The video was awarded first place at the 2018 CINEFISH film festival, held in Mexico.
Funding and grants
The CRCP funds a wide variety of coral reef management projects ranging from school science excursions, projects concerning the identification and mapping of coral ecosystems, the publication of educational materials and restoration initiatives.
Funding for hurricanes Irma and Maria
In 2017 Hurricanes Irma and Maria caused severe damage to the coral reefs in Florida and Puerto Rico, impacting ecosystem vulnerability and resilience. Funding to assist coral restoration was provided by the NOAA's CRCP and partners including the National Fish and Wildlife Foundation and National Marine Fisheries Service. The program led efforts to assess the impact of the hurricanes on local coral reef ecosystems and restore damage. The funds were used towards research and assessment to collect data on the impact of the hurricanes on the reefs and other crucial information, vital for effective decision-making. It was found that overturned coral reefs in Puerto Rico appeared to have macroalgal overgrowth, as evident in the figure, as a result of stress from the 2017 hurricanes. Scientists are concerned with the rapid growth of this macroalgae, and such findings are vital for effective management decision-making for the coral reef ecosystem
Funding the Hawaii Coastal Uses Mapping Project
The CRCP funds a number of projects and programs that are interested in the sustainable management of U.S. coral reef ecosystems, including the Hawaii Coastal Uses Mapping Project. The project involved gathering data and information on the impact of human activity near coastal environments on coral reef ecosystems surrounding Hawaii, by using a participatory geographic information systems (PGIS) methodology. PGIS is an effective means to obtain critical sociospatial information which includes data regarding the location of resources and the location of ecosystem related concerns, and is very useful information for a number of stakeholders involved in coastal ecosystem management including state and federal managers. Prior to the implementation of the program there was very little sociospatial data collected on the Hawaii coast.
Funding Research
The CRCP provides financial support to a number of institutional organisations with the purpose of funding and supporting the development of research papers interested in the restoration and protection of coral reef ecosystems. In 2015 the NOAA CRCP funded a study run by the Florida International University, which found that 'grazing fish can help save imperilled coral reefs'. The CRCP has also funded a number of studies on the impacts of climate change on coral reefs and the effectiveness of new management strategies. The article 'Climate-smart Design for Ecosystem Management' from the Environmental Management Journal, was partly funded by the CRCP and examines and assesses adaptation strategies for coral reefs.
References
Oceanographic organizations
Hydrology organizations
Earth sciences organizations
National Oceanic and Atmospheric Administration | Coral Reef Conservation Program | Environmental_science | 2,549 |
6,716,887 | https://en.wikipedia.org/wiki/Matti%20Jutila | Matti Ilmari Jutila (born 1943) is a mathematician and a professor emeritus at the University of Turku. He researches in the field of analytic number theory.
Education and career
Jutila completed a doctorate at the University of Turku in 1970, with a dissertation related to Linnik's constant supervised by .
Jutila's work has repeatedly succeeded in lowering the upper bound for Linnik's constant. He is the author of a monograph, Lectures on a method in the theory of exponential sums (1987). He has been a member of the Finnish Academy of Science and Letters since 1982.
References
External links
1943 births
Living people
Finnish mathematicians
Number theorists
Members of the Finnish Academy of Science and Letters | Matti Jutila | Mathematics | 145 |
32,264,875 | https://en.wikipedia.org/wiki/Raspberry%20Pi%20Foundation | The Raspberry Pi Foundation is a registered charity in England and Wales, as well as an England and Wales company limited by guarantee. It was founded in 2009 to promote the study of computer science. It is part of a group that comprises legal entities in India, Ireland, and the United States, which carry out educational activities in those jurisdictions; and Raspberry Pi Ltd, a commercial subsidiary that develops Raspberry Pi computers and other hardware. The foundation’s charitable activities are funded through a combination of Gift Aid from the profits of Raspberry Pi Ltd, contracts for the delivery of educational services e.g. professional development for teachers, and donations from individuals, foundations, and other organisations.
Foundation
The Raspberry Pi Foundation is a charitable organisation registered with the Charity Commission for England and Wales. The board of trustees was assembled by 2008, and the Raspberry Pi Foundation was founded as a registered charity in May 2009 in Caldecote, England. In 2016, The foundation moved its headquarters to Station Road, Cambridge, moving again in 2018, to Hills Road, Cambridge.
The foundation is supported by the University of Cambridge Computer Laboratory and Broadcom.
Its aim is to "promote the study of computer science and related topics, especially at the school level, and to put the fun back into learning computing." Project co-founder Eben Upton is a former academic, currently employed by Broadcom as a system-on-chip architect and associate technical director. Components, albeit in small numbers, were able to be sourced from suppliers, due to the charitable status of the organisation.
History
When the decline in numbers and skills of students applying for Computer Science became a concern for a team that included Eben Upton, Rob Mullins, Jack Lang and Alan Mycroft at the University of Cambridge’s Computer Laboratory in 2006, a need for a tiny and affordable computer came to their minds. Several versions of the early Raspberry Pi prototypes were designed but were very limited by the high cost and low power processors for mobile devices at that time.
In 2008, the team started a collaboration with Pete Lomas, MD of Norcott Technologies and David Braben, the co-author of the seminal BBC Micro game Elite, and formed the Raspberry Pi Foundation. Three years later, the Raspberry Pi Model B was born and it had sold over two million units within two years of mass production.
Founders and leadership
The founders of the organisation were:
Eben Upton
Rob Mullins, senior lecturer in the Computer Laboratory at the University of Cambridge
Jack Lang, affiliated lecturer in the Computer Laboratory at the University of Cambridge and the founder of Electronic Share Information Ltd
Alan Mycroft, professor of computing in the Computer Laboratory at the University of Cambridge
David Braben, CEO of Frontier Developments and co-writer of the 1984 game Elite
Pete Lomas, MD of Norcott Technologies
In early 2013, the organisation split into two parts: Raspberry Pi Foundation, which is responsible for the charitable and educational activities; and Raspberry Pi (Trading) Ltd, responsible for the engineering and trading activities. Raspberry Pi (Trading) Ltd is a wholly owned subsidiary of Raspberry Pi Foundation, with the money earned from sales of Raspberry Pi products being used to fund the charitable work of the Foundation. Eben Upton was initially CEO of both divisions, but in September 2013 Lance Howarth became CEO of the Raspberry Pi Foundation, with Eben Upton remaining as CEO of Raspberry Pi (Trading) Ltd. Philip Colligan took over from Lance Howarth as CEO of Raspberry Pi Foundation in July 2015.
In 2021 Raspberry Pi (Trading) Ltd changed its name to Raspberry Pi Ltd. Its newly-formed holding company, Raspberry Pi Holdings, was the subject of an initial public offering on the London Stock Exchange in June 2024.
Logo
In October 2011, the foundation's logo was selected from a number submitted from open competition. A shortlist of six was drawn up, with the final judging taking several days. The chosen design was created by Paul Beech and depicts a raspberry, in the style of a buckminsterfullerene molecule.
Education fund
In April 2014, the foundation announced a £1million education fund to support projects that enhance the understanding of computing and to promote the use of technology in other subjects, particularly STEM and creative arts for children. They offered to provide up to 50% of the total projected costs to successful applicants. Carrie Anne Philbin was the Director of Education.
Mergers
In 2015, the Raspberry Pi Foundation merged with Code Club. In 2017, it merged with CoderDojo.
Bebras
The Raspberry Foundation is an active sponsor of the British edition of the International Bebras Computing competition, together with the University of Oxford.
Magazine
The foundation publishes Hello World, a "computing and digital making" magazine. From 2018 to early 2023, the foundation published Wireframe, a video game development magazine.
References
External links
Foundations based in the United Kingdom
Charities based in Cambridgeshire
Computer science organizations
Education advocacy groups
Educational charities based in the United Kingdom
Educational technology non-profits
organizations established in 2009
Raspberry Pi | Raspberry Pi Foundation | Technology | 1,048 |
36,830,673 | https://en.wikipedia.org/wiki/Hurwitz%20problem | In mathematics, the Hurwitz problem (named after Adolf Hurwitz) is the problem of finding multiplicative relations between quadratic forms which generalise those known to exist between sums of squares in certain numbers of variables.
Description
There are well-known multiplicative relationships between sums of squares in two variables
(known as the Brahmagupta–Fibonacci identity), and also Euler's four-square identity and Degen's eight-square identity. These may be interpreted as multiplicativity for the norms on the complex numbers (), quaternions (), and octonions (), respectively.
The Hurwitz problem for the field is to find general relations of the form
with the being bilinear forms in the and : that is, each is a -linear combination of terms of the form .
We call a triple admissible for if such an identity exists. Trivial cases of admissible triples include The problem is uninteresting for of characteristic 2, since over such fields every sum of squares is a square, and we exclude this case. It is believed that otherwise admissibility is independent of the field of definition.
The Hurwitz–Radon theorem
Hurwitz posed the problem in 1898 in the special case and showed that, when coefficients are taken in , the only admissible values were His proof extends to a field of any characteristic except 2.
The "Hurwitz–Radon" problem is that of finding admissible triples of the form Obviously is admissible. The Hurwitz–Radon theorem states that is admissible over any field where is the function defined for odd, with and
Other admissible triples include and
See also
Composition algebra
Hurwitz's theorem (normed division algebras)
Radon–Hurwitz number
References
Field (mathematics)
Quadratic forms
Mathematical problems | Hurwitz problem | Mathematics | 387 |
72,080,374 | https://en.wikipedia.org/wiki/Leucocoprinus%20viridiflavoides | Leucocoprinus viridiflavoides is a species of mushroom producing fungus in the family Agaricaceae. It may still be known as Leucoagaricus viridiflavoides.
Taxonomy
It was first described in 2000 by Brian P. Akers and Sherri A. Angels who classified it as Leucoagaricus viridiflavoides.
In 2012 it was reclassified as Leucocoprinus viridiflavoides by Erhard Ludwig.
Description
Leucocoprinus viridiflavoides is a small dapperling mushroom with yellow flesh that discolours olive or green when damaged or cut.
Cap: 1.6–3.5 cm wide, convex to nearly planar and obtusely umbonate. The surface colour is quite variable and may be a dull brownish to gray to nearly black to greenish colour. It can be almost smooth or covered in minute, grainy scales which are more concentrated at the central disc and thinner or paler towards the edges and may rarely split into concentric rings of scales exposing the yellow flesh beneath. The cap surface may become slightly sticky when moist and both the flesh and the surface bruise bluish-green when handled or with damage and it dries to a greenish or yellowish grey. The cap margins occasionally have minute striations but are often without any striations, which is unusual for Leucocoprinus species and more consistent with Leucoagaricus. The edges may often split almost to the disc and may sometimes present with an appendiculate margin, that is with veil fragments on the cap edges. Stem: 1.8–4.5 cm tall and up to 3mm thick and roughly equal in thickness across the whole stem. The interior of the stem is hollow whilst the surface is sulphur yellow but likewise discolours bluish-green when handled, it is smooth but sometimes minutely scaly at the base on young specimens. The membranous stem ring is sulphur yellow and located towards the top of the stem (superior) but it sometimes disappears. Gills: Free, close to subdistant and pale yellow but likewise bruising bluish green when touched. Upon cutting the gills discolour to a dull pink and they dry to yellow with bluish-green or yellowish-gray edges. Smell: Mild and pleasant. Spore print: Pale yellow. Spores: Ellipsoid to ovoid to amygdaliform with an indistinct germ pore. Detrinoid. 5.3–11 x 3.4–5.1 μm.
Habitat and distribution
L. viridiflavoides is scarcely recorded and little known and is considered to be a rare species. The specimens studied by Akers and Angels were found in Florida where they were growing scattered on the ground in the San Felasco Hammock Preserve State Park.
Similar species
There are a small number of similarly green bruising greenish-yellow species including Leucoagaricus sulphurellus, Leucocoprinus viridiflavus, Leucoagaricus viriditinctus, Lepiota cyanescens and Leucoagaricus houaynhangensis. The genera in which they should be placed is not necessarily certain and some of these species may still be known under previous classifications within Lepiota, Leucocoprinus or Leucoagaricus or may be subject to reclassification as some of these species are poorly documented and all are scarcely observed. As the macroscopic characteristics of these species are similar and unusual within these genera it may take microscopic analysis to distinguish them.
References
viridiflavoides
Fungi described in 2000
Fungi of Florida
Fungus species | Leucocoprinus viridiflavoides | Biology | 762 |
56,240,950 | https://en.wikipedia.org/wiki/PyCBC | PyCBC is an open source software package primarily written in the Python programming language which is designed for use in gravitational-wave astronomy and gravitational-wave data analysis. PyCBC contains modules for signal processing, FFT, matched filtering, gravitational waveform generation, among other tasks common in gravitational-wave data analysis.
The software is developed by the gravitational-wave community alongside LIGO and Virgo scientists to analyze gravitational-wave data, search for gravitational-waves, and to measure the properties of astrophysical sources. It has been used to analyze gravitational-wave data from the LIGO and Virgo observatories to detect gravitational-waves from the mergers of neutron stars and black holes and determine their statistical significance. PyCBC based analyses can integrate with the Open Science Grid for large scale computing resources. Software based on PyCBC has been used to rapidly analyze gravitational-wave data for astronomical follow-up.
See also
List of numerical analysis software
LIGO Scientific Collaboration
European Gravitational Observatory
References
External links
GitHub repository
Physics software
Astronomy software
Free and open-source software
Astronomy
Software using the GNU General Public License
Free software programmed in Python | PyCBC | Physics,Astronomy | 235 |
30,953,521 | https://en.wikipedia.org/wiki/Neutron%20moisture%20gauge | A neutron moisture meter is a moisture meter utilizing neutron scattering. The meters are most frequently used to measure the water content in soil or rock. The technique is non-destructive, and is sensitive to moisture in the bulk of the target material, not just at the surface.
Water, due to its hydrogen content, is an effective neutron moderator, slowing high-energy neutrons. With a source of high-energy neutrons and a detector sensitive to low-energy neutrons (thermal neutrons), the detection rate will be governed by the water content of the soil between the source and the detector. The neutron source typically contains a small amount of a radionuclide. Sources may emit neutrons during spontaneous fission, as with californium; alternatively, an alpha emitter may be mixed with a light element for a nuclear reaction yielding excess neutrons, as with americium in a beryllium matrix.
References
Californium
Moisture gauge
Moisture gauge
Radioactivity
Scattering | Neutron moisture gauge | Physics,Chemistry,Materials_science | 201 |
21,215,692 | https://en.wikipedia.org/wiki/Difetarsone | Difetarsone is an antiprotozoal agent. Various studies have shown it to be particularly effective against Trichuris trichiura, commonly known as the whipworm. Prior to the drugs use in the early 1970s, there were few effective treatments for this infection. It has also been used to treat Entamoeba histolytica infections.
Difetarsone often has minor side effects, which include rashes, nausea and vomiting. It has also resulted in angioedema in at least one known case.
References
Antiprotozoal agents
Arsonic acids | Difetarsone | Biology | 122 |
14,207 | https://en.wikipedia.org/wiki/Hematite | Hematite (), also spelled as haematite, is a common iron oxide compound with the formula, Fe2O3 and is widely found in rocks and soils. Hematite crystals belong to the rhombohedral lattice system which is designated the alpha polymorph of . It has the same crystal structure as corundum () and ilmenite (). With this it forms a complete solid solution at temperatures above .
Hematite occurs naturally in black to steel or silver-gray, brown to reddish-brown, or red colors. It is mined as an important ore mineral of iron. It is electrically conductive. Hematite varieties include kidney ore, martite (pseudomorphs after magnetite), iron rose and specularite (specular hematite). While these forms vary, they all have a rust-red streak. Hematite is not only harder than pure iron, but also much more brittle. The term kidney ore may be broadly used to describe botryoidal, mammillary, or reniform hematite. Maghemite is a polymorph of hematite (γ-) with the same chemical formula, but with a spinel structure like magnetite.
Large deposits of hematite are found in banded iron formations. Gray hematite is typically found in places that have still, standing water, or mineral hot springs, such as those in Yellowstone National Park in North America. The mineral may precipitate in the water and collect in layers at the bottom of the lake, spring, or other standing water. Hematite can also occur in the absence of water, usually as the result of volcanic activity.
Clay-sized hematite crystals also may occur as a secondary mineral formed by weathering processes in soil, and along with other iron oxides or oxyhydroxides such as goethite, which is responsible for the red color of many tropical, ancient, or otherwise highly weathered soils.
Etymology and history
The name hematite is derived from the Greek word for blood, (haima), due to the red coloration found in some varieties of hematite. The color of hematite is often used as a pigment. The English name of the stone is derived from Middle French hématite pierre, which was taken from Latin lapis haematites the 15th century, which originated from Ancient Greek (haimatitēs lithos, "blood-red stone").
Ochre is a clay that is colored by varying amounts of hematite, varying between 20% and 70%. Red ochre contains unhydrated hematite, whereas yellow ochre contains hydrated hematite (Fe2O3 · H2O). The principal use of ochre is for tinting with a permanent color.
Use of the red chalk of this iron-oxide mineral in writing, drawing, and decoration is among the earliest in human history. To date, the earliest known human use of the powdery mineral is 164,000 years ago by the inhabitants of the Pinnacle Point caves in what now is South Africa, possibly for social purposes. Hematite residues are also found in graves from 80,000 years ago. Near Rydno in Poland and Lovas in Hungary red chalk mines have been found that are from 5000 BC, belonging to the Linear Pottery culture at the Upper Rhine.
Rich deposits of hematite have been found on the island of Elba that have been mined since the time of the Etruscans.
Underground hematite mining is classified as carcinogenic hazard to humans.
Magnetism
Hematite shows only a very feeble response to a magnetic field. Unlike magnetite, it is not noticeably attracted to an ordinary magnet. Hematite is an antiferromagnetic material below the Morin transition at , and a canted antiferromagnet or weakly ferromagnetic above the Morin transition and below its Néel temperature at , above which it is paramagnetic.
The magnetic structure of α-hematite was the subject of considerable discussion and debate during the 1950s, as it appeared to be ferromagnetic with a Curie temperature of approximately , but with an extremely small magnetic moment (0.002 Bohr magnetons). Adding to the surprise was a transition with a decrease in temperature at around to a phase with no net magnetic moment. It was shown that the system is essentially antiferromagnetic, but that the low symmetry of the cation sites allows spin–orbit coupling to cause canting of the moments when they are in the plane perpendicular to the c axis. The disappearance of the moment with a decrease in temperature at is caused by a change in the anisotropy which causes the moments to align along the c axis. In this configuration, spin canting does not reduce the energy. The magnetic properties of bulk hematite differ from their nanoscale counterparts. For example, the Morin transition temperature of hematite decreases with a decrease in the particle size. The suppression of this transition has been observed in hematite nanoparticles and is attributed to the presence of impurities, water molecules and defects in the crystals lattice. Hematite is part of a complex solid solution oxyhydroxide system having various contents of H2O (water), hydroxyl groups and vacancy substitutions that affect the mineral's magnetic and crystal chemical properties. Two other end-members are referred to as protohematite and hydrohematite.
Enhanced magnetic coercivities for hematite have been achieved by dry-heating a two-line ferrihydrite precursor prepared from solution. Hematite exhibited temperature-dependent magnetic coercivity values ranging from . The origin of these high coercivity values has been interpreted as a consequence of the subparticle structure induced by the different particle and crystallite size growth rates at increasing annealing temperature. These differences in the growth rates are translated into a progressive development of a subparticle structure at the nanoscale (super small). At lower temperatures (350–600 °C), single particles crystallize. However, at higher temperatures (600–1000 °C), the growth of crystalline aggregates, and a subparticle structure is favored.
Mine tailings
Hematite is present in the waste tailings of iron mines. A recently developed process, magnetation, uses magnets to glean waste hematite from old mine tailings in Minnesota's vast Mesabi Range iron district. Falu red is a pigment used in traditional Swedish house paints. Originally, it was made from tailings of the Falu mine.
Mars
The spectral signature of hematite was seen on the planet Mars by the infrared spectrometer on the NASA Mars Global Surveyor and 2001 Mars Odyssey spacecraft in orbit around Mars. The mineral was seen in abundance at two sites on the planet, the Terra Meridiani site, near the Martian equator at 0° longitude, and the Aram Chaos site near the Valles Marineris. Several other sites also showed hematite, such as Aureum Chaos. Because terrestrial hematite is typically a mineral formed in aqueous environments or by aqueous alteration, this detection was scientifically interesting enough that the second of the two Mars Exploration Rovers was sent to a site in the Terra Meridiani region designated Meridiani Planum. In-situ investigations by the Opportunity rover showed a significant amount of hematite, much of it in the form of small "Martian spherules" that were informally named "blueberries" by the science team. Analysis indicates that these spherules are apparently concretions formed from a water solution. "Knowing just how the hematite on Mars was formed will help us characterize the past environment and determine whether that environment was favorable for life".
Jewelry
Hematite is often shaped into beads, tumbling stones, and other jewellery components. Hematite was once used as mourning jewelry. Certain types of hematite- or iron-oxide-rich clay, especially Armenian bole, have been used in gilding. Hematite is also used in art such as in the creation of intaglio engraved gems. Hematine is a synthetic material sold as magnetic hematite.
Pigment
Hematite has been sourced to make pigments since earlier origins of human pictorial depictions, such as on cave linings and other surfaces, and has been employed continually in artwork through the eras. In Roman times, the pigment obtained by finely grinding hematite was known as sil atticum. Other names for the mineral when used in painting include colcotar and caput mortuum. In Spanish, it is called almagre or almagra, from the Arabic al-maghrah, red earth, which passed into English and Portuguese. Other ancient names for the pigment include ochra hispanica, sil atticum antiquorum, and Spanish brown. It forms the basis for red, purple, and brown iron-oxide pigments, as well as being an important component of ochre, sienna, and umber pigments. The main producer of hematite for the pigment industry is India, followed distantly by Spain.
Industrial purposes
As mentioned earlier, hematite is an important mineral for iron ore. The physical properties of hematite are also employed in the areas of medical equipment, shipping industries, and coal production. Having high density and capable as an effective barrier against X-ray passage, it often is incorporated into radiation shielding. As with other iron ores, it often is a component of ship ballasts because of its density and economy. In the coal industry, it can be formed into a high specific density solution, to help separate coal powder from impurities.
Gallery
See also
Mill scale
Mineral redox buffer
Wüstite
References
External links
MineralData.org
Oxide minerals
Iron(III) minerals
Iron oxide pigments
Hematite group
Trigonal minerals
Minerals in space group 167
Iron ores
Glances
Magnetic minerals
Jewellery components
Symbols of Alabama | Hematite | Technology | 2,066 |
36,448,733 | https://en.wikipedia.org/wiki/Wison%20Group | Wison Group () is an engineering, procurement, and construction company, or EPC firm which focuses on the industries of energy and high-technology. The company attracted significant international coverage in the first half of 2012 by winning a contract to “engineer, procure, construct, install, and commission” (EPCIC) the world's first “floating LNG liquefaction, regasification, and storage unit” off the coast of Colombia. Wison also formed a consortium with Hyundai Engineering & Construction Co. to sign a contract with PDVSA, Venezuela's state-owned oil company, to expand PDVSA's Puerto la Cruz refinery.
History
1997 Wison Chemical Engineering Co., Ltd. was established. The company focused on domestic petrochemical projects.
2003 Wison Group was established. Following this expansion, Wison Group moved into its current location at Zhangjiang Hi-tech Park in Pudong New Area, Shanghai.
2006 Wison Offshore & Marine was founded.
2008 Wison signed an EPC contract with CNOOC Shell for an Ethylene Cracking Furnace Debottlenecking Project, providing Wison with its first foreign-funded project. The company focused on producing CO and other gases.
2011 Wison Group Clean Energy Co., was established in Nanjing, China. Wison Engineering, together with Daelim of South Korea, signed a MDI project contract with BASF.
2012 Wison Engineering was officially listed on the Main Board of The Stock Exchange of Hong Kong Limited (“HKEx”) on December 28, 2012, and stock code is 2236
In 2014, the Wison Engineering Services and its chairman and majority owner Hua Bangsong were charged with bribery in China. Wison denied the charge.
Operations
The Group is composed of four different business sectors: Engineering Services, Offshore & Marine, Clean Energy, and Emerging Business.
Engineering Services
Wison Engineering Ltd. provides engineering, construction and technical services for engineering projects in petrochemical industries. The Group works with foreign and domestic clients as a provider of design, procurement, construction management, and project planning consultation work. Partners and long-term clients include Shell
and BASF.
As the largest private sector chemical engineering, procurement and construction management ("EPC") service provider in China in terms of revenue for 2011, as estimated by CMAI (Shanghai) Limited (CMAI), an independent industry consultant. The company specializes in the provision of construction and technical services for engineering installations in the petrochemical, coal-to-chemical and refining industries. Aside from the provision of EPC service, the Company manufactures integrated piping systems comprising heat-resistant alloy tubes and fittings through its wholly owned subsidiary, Wison (Yangzhou) Chemical Machinery Co., Ltd.
The company has developed various proprietary technologies, including HS-I, HS-II and HS-III cracking furnace proprietary technologies, certain MTO light olefins separation technologies and WMTO process technologies.
Offshore and Marine
Wison Offshore & Marine is a division of the Wison Group in the upstream oil and gas industry. This subsidiary focuses on design, project management, construction and operations of offshore oil projects. These include fixed platforms and modules, offshore lifting equipment mooring systems, and other types of oil and gas developments.
Wison Offshore & Marine operates two fabrication yards that are dedicated to the construction of offshore oil and gas facilities.
Clean Energy
Wison (Nanjing) Clean Energy Co., Ltd. is a company within the Wison Group that utilizes coal as feedstock and uses production technologies to provide customers with a supply of chemicals, including hydrogen, carbon monoxide, sulfur, methanol and butyl-octyl alcohol in an eco-friendly manner. Wison Clean energy holds long-term contracts will domestic and international chemical corporations, including Celanese, BASF-YPC, DMAC, and Bluestar.
Emerging Business
In 2007, Gener BioPharma Co., Ltd., a company with a focus on creating novel human vaccines through antibody research, development, manufacturing, and commercialization, was introduced under the Wison Group name.
Facilities
Wison Group Headquarters are in Shanghai, China, at the Zhangjiang Hi-Tech Park. The building was designed by Architecture-Studio, based in Paris, France. The firm also has a shipbuilding yard in Nantong, China, on the banks of the Yangtze River and is building a second fabrication facility in Zhoushan, China, that will be focused on the construction of onshore and offshore modules, large floating production hulls, topsides and jackets.
Corporate social responsibility
In 2011, the Wison Group introduced the “Wison Shinai Prize in Literature.” The prize was introduced to encourage and promote innovation in Chinese schools. The first place prize is 100,000 yuan.
In 2005, Wison Group founded the Wison Art center at their headquarters in Shanghai to support local and international art. The center has shown works from famous painters including Chen Danqung and Chinese contemporary sculptor Wu Weishan.
Major projects
In March, 2011, Wison Engineering, a subsidiary of Wison Group, finished construction on the world's largest single production capacity of an ethylene cracking furnace. The plant, with a production capacity is up to 192,000 tons/year, was handed over to BASF-YPC. The old record of 150,000 tons/year was also held by a cracking plant that Wison Group constructed.
In June, 2012, Wison Offshore & Marine, a subsidiary to Wison Group, was awarded the contract to build the 'world's first floating LNG Liquefaction, Regasification, and Storage unit.' Referred to as a FLRSU, the production unit will be delivered to Exmar under a contract with Pacific Rubiales Energy Corp. to start operation in Q4 2014 off the coast of Colombia. It will be a non-propelled barge, and will have a capacity of converting per day of natural gas into LNG. It will be built in the Wison Offshore & Marine fabrication facility in Nantong, China. Additional assistance will be provided by the Houston, Texas branch of Wison Offshore & Marine. Black & Veatch will provide engineering and procurement of the topside liquefaction equipment.
See also
Zhangjiang Hi-tech Park
List of Chinese companies
Architecture-Studio
Shanghai
References
Companies established in 1997
Energy engineering and contractor companies
Companies based in Shanghai | Wison Group | Engineering | 1,313 |
637,228 | https://en.wikipedia.org/wiki/Hulett | The Hulett was an ore unloader that was widely used on the Great Lakes of North America. It was unsuited to tidewater ports because it could not adjust for rising and falling tides, although one was used in New York City.
History
The Hulett was invented by George Hulett of Conneaut, Ohio, in the late 19th century; he received a patent for his invention in 1898. The first working machine was built the following year at Conneaut Harbor.
It was steam powered, successful, and many more were built along the Great Lakes, especially the southern shore of Lake Erie to unload boats full of taconite from the iron mines near Lake Superior. John W. Ahlberg converted the Huletts in Conneaut to electricity in the 1920's. Substantial improvements were later made on the design by Samuel T. Wellman.
The Hulett machine revolutionised iron ore shipment on the Great Lakes. Previous methods of unloading lake freighters, involving hoists and buckets and much hand labor, cost approximately 18¢/ton. Unloading with Huletts cost only 6¢/ton. (in 1901 dollars) Unloading only took 5 to 10 hours, as opposed to days for previous methods. Lake boat designs changed to accommodate the Hulett unloader, and became much larger, doubling in length and quadrupling in capacity.
By 1913, 54 Hulett machines were in service. Two were built at Lake Superior (unloading coal) and five at Gary, Indiana, but the vast majority were along the shores of Lake Erie. The additional unloading capacity they brought helped permit a greater than doubling of the ore traffic in the 1900–1912 period. A total of approximately 75 Huletts were built. One was installed in New York City to unload garbage.
The lake's Huletts were used until about 1992, when self-unloading boats were standard on the American side of the lake. All have since been dismantled. In 1999, only six remained, the group of four at Whiskey Island in Cleveland, the oldest. Another set was used unloading barges of coal in South Chicago until 2002 and were demolished in the spring of 2010.
In spite of the Cleveland machines being on the National Register of Historic Places and designated as a Historic Mechanical Engineering Landmark, they were demolished in 2000 by the Cleveland-Cuyahoga County Port Authority to enable development of the underlying land. The Port Authority disassembled and retained two Huletts, to enable their reconstruction at another site, but the reconstruction never started. In March 2024 the Port Authority initially chose a demolition contractor that intended to reassemble one unloader in nearby Canton, but they chose another contractor later in the month, which expects to salvage the arms and buckets. The last two remaining Huletts were scrapped in June 2024.
Operation
The electrically powered Hulett unloader rode on two parallel tracks along the docks, one near the edge and one further back, ordinarily with four railroad tracks in between. Steel towers, riding on wheeled trucks, supported girders that spanned the railroad tracks.
Along these girders ran a carriage which could move toward or away from the dock face. This in turn carried a large walking beam which could be raised or lowered; at the dock end of this was a vertical column with a large scoop bucket on the end. A parallel beam was mounted halfway down this column to keep the column vertical as it was raised or lowered. The machine's operator, stationed in the vertical beam above the bucket for maximum cargo visibility, could spin the beam at any angle. The scoop bucket was lowered into the ship's hold, closed to capture a quantity (10 tons approx.) of ore, raised, and moved back toward the dock. The workmen who operated the Hulett uploaders were known as Ore Hogs.
To reduce the required motion of the carriage, a moving receiving hopper ran between the main girders. It was moved to the front for the main bucket to discharge its load, and then moved back to dump it into a waiting railroad car, or out onto a cantilever frame at the back to dump the load onto a stockpile.
The Hulett could move along the dock to align with the holds on an ore boat. When the hold was almost empty, the Hulett could not finish the job itself. Workmen entered the hold and shoveled the remaining ore into the Hulett's bucket. In a later development, a wheeled excavator was chained to the Hulett's bucket and lowered into the hold to fill the Hulett.
References
External links
Hulett Automatic Ore Unloaders Home Page at the Great Lakes Industrial History Center
Hulett Ore Unloaders and George H. Hulett at the Encyclopedia of Cleveland History
by the American Society of Mechanical Engineers (ASME)
Citizens Vision preservation advocacy site (photo)
Comprehensive video showing Huletts in operation (video)
Bulk-handling cranes
Bulk material handling
Historic American Engineering Record in Ohio
Maritime history
Great Lakes
Engineering vehicles
Industrial Revolution
Steelmaking
Culture of Cleveland
History of Cleveland | Hulett | Chemistry,Engineering | 1,041 |
49,295,086 | https://en.wikipedia.org/wiki/Mirvetuximab%20soravtansine | Mirvetuximab soravtansine, sold under the brand name Elahere, is a medication used as a treatment for epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer. Mirvetuximab soravtansine is a folate receptor alpha directed antibody and microtubule inhibitor conjugate.
The most common adverse reactions, including laboratory abnormalities, were vision impairment, fatigue, increased aspartate aminotransferase, nausea, increased alanine aminotransferase, keratopathy, abdominal pain, decreased lymphocytes, peripheral neuropathy, diarrhea, decreased albumin, constipation, increased alkaline phosphatase, dry eye, decreased magnesium, decreased leukocytes, decreased neutrophils, and decreased hemoglobin.
Mirvetuximab soravtansine was approved for medical use in the United States in November 2022. The US Food and Drug Administration (FDA) considers it to be a first-in-class medication.
Medical uses
Mirvetuximab soravtansine is indicated for the treatment of adults with folate receptor alpha (FRα) positive, platinum-resistant epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer, who have received one to three prior systemic treatment regimens. Recipients are selected for therapy based on an FDA-approved test.
Adverse effects
The product labeling includes a boxed warning for ocular toxicity.
History
Efficacy was evaluated in Study 0417 (NCT04296890), a single-arm trial of 106 participants with FRα positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer. Participants were permitted to receive up to three prior lines of systemic therapy. All participants were required to have received bevacizumab. The trial enrolled participants whose tumors were positive for FRα expression as determined by the above assay. Participants were excluded if they had corneal disorders, ocular conditions requiring ongoing treatment, Grade >1 peripheral neuropathy, or noninfectious interstitial lung disease.
Efficacy was evaluated in Study 0416 (MIRASOL, NCT04209855), a multicenter, open-label, active-controlled, randomized, two-arm trial in 453 participants with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer. Participants were permitted to receive up to three prior lines of systemic therapy. The trial enrolled participants whose tumors were positive for FRα expression as determined by the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay. Participants were randomized (1:1) to receive mirvetuximab soravtansine-gynx 6 mg/kg (based on adjusted ideal body weight) as an intravenous infusion every 3 weeks or investigator’s choice of chemotherapy (paclitaxel, pegylated liposomal doxorubicin, or topotecan) until disease progression or unacceptable toxicity. The results from this trial satisfy the post-marketing requirement of the previous accelerated approval for mirvetuximab soravtansine-gynx.
Society and culture
Legal status
In September 2024, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Elahere, intended for the treatment of adults with folate receptor-alpha (FRα) positive epithelial ovarian, fallopian tube and primary peritoneal cancer. The applicant for this medicinal product is AbbVie Deutschland GmbH & Co. KG. Mirvetuximab soravtansine was authorized for use in the European Union in November 2024.
Names
Mirvetuximab soravtansine is the international nonproprietary name (INN).
References
Further reading
External links
Monoclonal antibodies for tumors
Antibody-drug conjugates | Mirvetuximab soravtansine | Biology | 871 |
71,459,264 | https://en.wikipedia.org/wiki/Black%20hole%20stability%20conjecture | The black hole stability conjecture is the conjecture that a perturbed Kerr black hole in Minkowski space will settle back down to a stable state. The question developed out of work in 1952 by the French mathematician Yvonne Choquet-Bruhat.
The stability of empty Minkowski space is a result of Klainerman and Christodoulou from 1993.
A 2016 by Hintz and Vasy paper proved the stability of slowly rotating Kerr black holes in de Sitter space.
A limited stability result for Kerr black holes in Schwarzschild space-time was published by Klainerman and Szeftel in 2017.
Culminating in 2022, a series of papers was published by Giorgi, Klainerman and Szeftel which present a proof of the conjecture for slowly rotating Kerr black holes in Minkowski space-time.
See also
Final state conjecture
Stability of matter
Positive energy theorem
Birkhoff's theorem (relativity)
Penrose–Hawking singularity theorems
Hoop conjecture
References
Black holes
General relativity
Conjectures that have been proved | Black hole stability conjecture | Physics,Astronomy,Mathematics | 213 |
70,426,705 | https://en.wikipedia.org/wiki/Tyra%20Wolfsberg | Tyra Gwendolen Wolfsberg is an American bioinformatician. She is the associate director of the bioinformatics and scientific programming core at the National Human Genome Research Institute.
Life
Wolfsberg received a A.B. in molecular biology from Princeton University. She earned a Ph.D. in biochemistry and biophysics from the University of California, San Francisco. Her 1995 dissertation was titled Identification and characterization of ADAM, a novel gene family. Wolfsberg transitioned to computationally based research by performing a postdoctoral fellowship at the National Center for Biotechnology Information (NCBI) at NIH. She worked as a staff scientist at NCBI before joining the National Human Genome Research Institute (NHGRI) faculty in 2000.
Wolfsberg is the associate director of NHGRI's bioinformatics and scientific programming core. Her research program focuses on developing methodologies to integrate sequence, annotation, and experimentally generated data so that bench biologists can quickly and easily obtain results for their large-scale experiments. She has collaborated with NHGRI investigators on a variety of projects, from genomic characterizations of DNAse I hypersensitive sites and retroviral integration sites to the annotation of the genome of the ctenophore Mnemiopsis leidyi. Her analysis of the Mnemiopsis genome helped to demonstrate that ctenophores are the oldest animal relatives of humans.
References
Living people
Year of birth missing (living people)
Place of birth missing (living people)
Princeton University alumni
University of California, San Francisco alumni
National Institutes of Health people
21st-century American women scientists
American bioinformaticians
Women bioinformaticians
21st-century American biologists
American medical researchers
American women medical researchers | Tyra Wolfsberg | Chemistry,Biology | 352 |
2,407,650 | https://en.wikipedia.org/wiki/Kaczmarz%20method | The Kaczmarz method or Kaczmarz's algorithm is an iterative algorithm for solving linear equation systems . It was first discovered by the Polish mathematician Stefan Kaczmarz, and was rediscovered in the field of image reconstruction from projections by Richard Gordon, Robert Bender, and Gabor Herman in 1970, where it is called the Algebraic Reconstruction Technique (ART). ART includes the positivity constraint, making it nonlinear.
The Kaczmarz method is applicable to any linear system of equations, but its computational advantage relative to other methods depends on the system being sparse. It has been demonstrated to be superior, in some biomedical imaging applications, to other methods such as the filtered backprojection method.
It has many applications ranging from computed tomography (CT) to signal processing. It can be obtained also by applying to the hyperplanes, described by the linear system, the method of successive projections onto convex sets (POCS).
Algorithm 1: Kaczmarz algorithm
The original Kaczmarz algorithm solves a complex-valued system of linear equations .
Let be the conjugate transpose of the -th row of . Initialize to be an arbitrary complex-valued initial approximation. For compute:
where iterates over the rows of in any order, deterministic or random. It is only necessary that each row is iterated infinitely often.
When we are in the space of real vectors, the Kaczmarz iteration has a clear geometric meaning. It means projecting orthogonally to the hyperplane defined by . In this interpretation, it is clear that if the Kaczmarz iteration converges, then it must converge to one of the solutions to .
A more general algorithm can be defined using a relaxation parameter
If the system has a solution, converges to the minimum-norm solution, provided that the iterations start with the zero vector. If the rows are iterated in order, and , then convergence is exponential.
There are versions of the method that converge to a regularized weighted least squares solution when applied to a system of inconsistent equations and, at least as far as initial behavior is concerned, at a lesser cost than other iterative methods, such as the conjugate gradient method.
Algorithm 2: Randomized Kaczmarz algorithm
In 2009, a randomized version of the Kaczmarz method for overdetermined linear systems was introduced by Thomas Strohmer and Roman Vershynin in which the i-th equation is selected randomly with probability proportional to
This method can be seen as a particular case of stochastic gradient descent.
Under such circumstances converges exponentially fast to the solution of and the rate of convergence depends only on the scaled condition number .
Theorem. Let be the solution of Then Algorithm 2 converges to in expectation, with the average error:
Proof
We have
Using
we can write () as
The main point of the proof is to view the left hand side in () as an expectation of some random variable. Namely, recall that the solution space of the equation of is the hyperplane
whose normal is Define a random vector Z whose values are the normals to all the equations of , with probabilities as in our algorithm:
with probability
Then () says that
The orthogonal projection onto the solution space of a random equation of is given by
Now we are ready to analyze our algorithm. We want to show that the error reduces at each step in average (conditioned on the previous steps) by at least the factor of The next approximation is computed from as where are independent realizations of the random projection The vector is in the kernel of It is orthogonal to the solution space of the equation onto which projects, which contains the vector (recall that is the solution to all equations). The orthogonality of these two vectors then yields
To complete the proof, we have to bound from below. By the definition of , we have
where are independent realizations of the random vector
Thus
Now we take the expectation of both sides conditional upon the choice of the random vectors (hence we fix the choice of the random projections and thus the random vectors and we average over the random vector ). Then
By () and the independence,
Taking the full expectation of both sides, we conclude that
The superiority of this selection was illustrated with the reconstruction of a bandlimited function from its nonuniformly spaced sampling values. However, it has been pointed out that the reported success by Strohmer and Vershynin depends on the specific choices that were made there in translating the underlying problem, whose geometrical nature is to find a common point of a set of hyperplanes, into a system of algebraic equations. There will always be legitimate algebraic representations of the underlying problem for which the selection method in will perform in an inferior manner.
The Kaczmarz iteration () has a purely geometric interpretation: the algorithm successively projects the current iterate onto the hyperplane defined by the next equation. Hence, any scaling of the equations is irrelevant; it can also be seen from () that any (nonzero) scaling of the equations cancels out. Thus, in RK, one can use or any other weights that may be relevant. Specifically, in the above-mentioned reconstruction example, the equations were chosen with probability proportional to the average distance of each sample point from its two nearest neighbors — a concept introduced by Feichtinger and Gröchenig. For additional progress on this topic, see, and the references therein.
Algorithm 3: Gower-Richtarik algorithm
In 2015, Robert M. Gower and Peter Richtarik developed a versatile randomized iterative method for solving a consistent system of linear equations which includes the randomized Kaczmarz algorithm as a special case. Other special cases include randomized coordinate descent, randomized Gaussian descent and randomized Newton method. Block versions and versions with importance sampling of all these methods also arise as special cases. The method is shown to enjoy exponential rate decay (in expectation) - also known as linear convergence, under very mild conditions on the way randomness enters the algorithm. The Gower-Richtarik method is the first algorithm uncovering a "sibling" relationship between these methods, some of which were independently proposed before, while many of which were new.
Insights about Randomized Kaczmarz
Interesting new insights about the randomized Kaczmarz method that can be gained from the analysis of the method include:
The general rate of the Gower-Richtarik algorithm precisely recovers the rate of the randomized Kaczmarz method in the special case when it reduced to it.
The choice of probabilities for which the randomized Kaczmarz algorithm was originally formulated and analyzed (probabilities proportional to the squares of the row norms) is not optimal. Optimal probabilities are the solution of a certain semidefinite program. The theoretical complexity of randomized Kaczmarz with the optimal probabilities can be arbitrarily better than the complexity for the standard probabilities. However, the amount by which it is better depends on the matrix . There are problems for which the standard probabilities are optimal.
When applied to a system with matrix which is positive definite, Randomized Kaczmarz method is equivalent to the Stochastic Gradient Descent (SGD) method (with a very special stepsize) for minimizing the strongly convex quadratic function Note that since is convex, the minimizers of must satisfy , which is equivalent to The "special stepsize" is the stepsize which leads to a point which in the one-dimensional line spanned by the stochastic gradient minimizes the Euclidean distance from the unknown(!) minimizer of , namely, from This insight is gained from a dual view of the iterative process (below described as "Optimization Viewpoint: Constrain and Approximate").
Six Equivalent Formulations
The Gower-Richtarik method enjoys six seemingly different but equivalent formulations, shedding additional light on how to interpret it (and, as a consequence, how to interpret its many variants, including randomized Kaczmarz):
1. Sketching viewpoint: Sketch & Project
2. Optimization viewpoint: Constrain and Approximate
3. Geometric viewpoint: Random Intersect
4. Algebraic viewpoint 1: Random Linear Solve
5. Algebraic viewpoint 2: Random Update
6. Analytic viewpoint: Random Fixed Point
We now describe some of these viewpoints. The method depends on 2 parameters:
a positive definite matrix giving rise to a weighted Euclidean inner product and the induced norm
and a random matrix with as many rows as (and possibly random number of columns).
1. Sketch and Project
Given previous iterate the new point is computed by drawing a random matrix (in an iid fashion from some fixed distribution), and setting
That is, is obtained as the projection of onto the randomly sketched system . The idea behind this method is to pick in such a way that a projection onto the sketched system is substantially simpler than the solution of the original system . Randomized Kaczmarz method is obtained by picking to be the identity matrix, and to be the unit coordinate vector with probability Different choices of and lead to different variants of the method.
2. Constrain and Approximate
A seemingly different but entirely equivalent formulation of the method (obtained via Lagrangian duality) is
where is also allowed to vary, and where is any solution of the system Hence, is obtained by first constraining the update to the linear subspace spanned by the columns of the random matrix , i.e., to
and then choosing the point from this subspace which best approximates . This formulation may look surprising as it seems impossible to perform the approximation step due to the fact that is not known (after all, this is what we are trying the compute!). However, it is still possible to do this, simply because computed this way is the same as computed via the sketch and project formulation and since does not appear there.
5. Random Update
The update can also be written explicitly as
where by we denote the Moore-Penrose pseudo-inverse of matrix . Hence, the method can be written in the form , where is a random update vector.
Letting it can be shown that the system always has a solution , and that for all such solutions the vector is the same. Hence, it does not matter which of these solutions is chosen, and the method can be also written as . The pseudo-inverse leads just to one particular solution. The role of the pseudo-inverse is twofold:
It allows the method to be written in the explicit "random update" form as above,
It makes the analysis simple through the final, sixth, formulation.
6. Random Fixed Point
If we subtract from both sides of the random update formula, denote
and use the fact that we arrive at the last formulation:
where is the identity matrix. The iteration matrix, is random, whence the name of this formulation.
Convergence
By taking conditional expectations in the 6th formulation (conditional on ), we obtain
By taking expectation again, and using the tower property of expectations, we obtain
Gower and Richtarik show that
where the matrix norm is defined by
Moreover, without any assumptions on one has By taking norms and unrolling the recurrence, we obtain
Theorem [Gower & Richtarik 2015]
Remark. A sufficient condition for the expected residuals to converge to 0 is This can be achieved if has a full column rank and under very mild conditions on Convergence of the method can be established also without the full column rank assumption in a different way.
It is also possible to show a stronger result:
Theorem [Gower & Richtarik 2015]
The expected squared norms (rather than norms of expectations) converge at the same rate:
Remark. This second type of convergence is stronger due to the following identity which holds for any random vector and any fixed vector :
Convergence of Randomized Kaczmarz
We have seen that the randomized Kaczmarz method appears as a special case of the Gower-Richtarik method for and being the unit coordinate vector with probability where is the row of It can be checked by direct calculation that
Further Special Cases
Algorithm 4: PLSS-Kaczmarz
Since the convergence of the (randomized) Kaczmarz method depends on a rate of convergence the method may make slow progress on some practical problems. To ensure finite termination of the method, Johannes Brust and Michael Saunders (academic)
have developed a process that generalizes the (randomized) Kaczmarz iteration and
terminates in at most iterations to a solution for the consistent system . The process is based on Dimensionality reduction, or projections
onto lower dimensional spaces, which is how it derives its name PLSS (Projected Linear Systems Solver). An iteration of PLSS-Kaczmarz can be regarded as the generalization
where is the selection of rows 1 to and all columns of . A randomized version of the method uses
non repeated row indices at each iteration: where each is in .
The iteration converges to a solution when . In particular, since it holds that
and therefore is a solution to the linear system. The computation of iterates in PLSS-Kaczmarz can be simplified and organized effectively.
The resulting algorithm only requires matrix-vector products and has a direct form
algorithm PLSS-Kaczmarz is
input: matrix A right hand side b
output: solution x such that Ax=b
x := 0, P = [0]
for k in 1,2,...,m do
a := A(ik,:)' // Select an index ik in 1,...,m without resampling
d := P' * a
c1 := norm(a)
c2 := norm(d)
c3 := (bik-x'*a)/((c1-c2)*(c1+c2))
p := c3*(a - P*(P'*a))
P := [ P, p/norm(p) ] // Append a normalized update x := x + p
return x''
Notes
References
External links
A randomized Kaczmarz algorithm with exponential convergence
Comments on the randomized Kaczmarz method
Kaczmarz algorithm in training Kolmogorov-Arnold network
Numerical linear algebra
Medical imaging
Signal processing | Kaczmarz method | Technology,Engineering | 2,930 |
2,789,245 | https://en.wikipedia.org/wiki/Surface%20web | The Surface Web (also called the Visible Web, Indexed Web, Indexable Web or Lightnet) is the portion of the World Wide Web that is readily available to the general public and searchable with standard web search engines. It is the opposite of the deep web, the part of the web not indexed by a web search engine. The Surface Web only consists of 10 percent of the information that is on the internet. The Surface Web is made with a collection of public web pages on a server accessible by any search engine.
According to one source, , Google's Index of the Surface Web contains about 14.8 billion pages.
See also
Clearnet (networking)
References
Internet search engines
Internet terminology
Dark web | Surface web | Technology | 144 |
65,362,635 | https://en.wikipedia.org/wiki/Kathrin%20Jansen | Kathrin U. Jansen (born 1958) is the former Head of Vaccine Research and Development at Pfizer. She previously led the development of the HPV vaccine (Gardasil) and newer versions of the pneumococcal conjugate vaccine (Prevnar), and is working with BioNTech to create a COVID-19 vaccine using mRNA (Pfizer–BioNTech COVID-19 vaccine) that was approved for Emergency Use Authorization in the United States on December 11, 2020.
Early life and education
Jansen was born in Erfurt, East Germany. She was frequently unwell as a child, and suffered several throat infections. The medical treatment she received from her father (antibiotics, codeine) inspired her to pursue a career in drug development. Her family fled to West Germany before the Berlin Wall was constructed in 1961. To transport Jansen across the border, her aunt pretended that she was her child, giving her some sleeping pills so that she didn't wake up and tell the border patrol the truth. Her family settled in Marl, North Rhine-Westphalia. She eventually studied biology at the University of Marburg, with the hope to work in the pharmaceutical industry. Whilst she was an undergraduate, Rudolf K. Thauer arrived at the university, and established a department of microbiology. Jansen completed her doctoral degree at the University of Marburg, where she studied chemical pathways in bacteria. After earning her degree, Jansen moved to Cornell University as an Alexander von Humboldt Foundation postdoctoral fellow investigating the function of the acetylcholine receptor with George Paul Hess. In particular, Jansen focussed on the yeast expression of multi-subunit neuronal receptors.
Research and career
Jansen was fascinated by the development of novel pharmaceuticals, and wanted to return to Europe, so moved to Geneva to join the Glaxo Institute for Molecular Biology. At the Glaxo Institute for Molecular Biology Jansen encouraged the immunologists to create a novel receptor for immunoglobulin E. She completed an internship in the laboratory of David Bishop at the University of Oxford, where she studied the expression of insect cells using baculoviridae.
In 1992 Jansen moved back to the United States, where she joined the vaccine division at Merck & Co. She became interested in making vaccines, and started work on the human papillomavirus infection. Soon after Jian Zhou and Ian Frazer started work on the HPV vaccine, proposing that the proteins of the human papillomavirus infection virus-like particles could be self assembled into something that could be used as a vaccine. Jansen proposed the vaccine should be made in yeast, a substrate which Merck & Co. had previously used for the Hepatitis B vaccine. Various innovations were required to ensure that the yeast did not degrade the virus like particles, and prevent their aggregation. Jansen managed to convince Edward Scolnick that the experimental vaccine was worth pursuing, and started to make the assays. Jansen worked with Laura Koutsky at the University of Washington to conduct natural history studies that informed the phase 2 clinical trials. In 2002 the vaccination was proven 100% effective, and Jansen left the Merck & Co. knowing that the vaccination would be a success.
She joined VaxGen in 2004, where she was appointed chief scientific officer. In 2006 Jansen left VaxGen to join Wyeth Pharmaceuticals in 2006, where she was responsible for vaccine discovery. Here she developed the pneumococcal conjugate vaccine (Prevnar-13). In 2010 Jansen was appointed adjunct professor at the University of Pennsylvania.
Jansen is concerned about the rise of vaccine hesitancy. During a conference at Pfizer in 2019, she said “I don't know what motivates an individual to ignore scientific facts. As scientists, it is our obligation to rectify misinformation and to provide the facts on what we know and what we don't know,”.
During the COVID-19 pandemic Jansen oversaw the development of the Pfizer COVID-19 vaccine. She looked at four potential candidates, before joining with BioNTech to improve the likelihood of identifying the vaccine with the highest potential. To test efficacy, Jansen and Pfizer are working under guidance from the Food and Drug Administration and conducting a 30,000 patient study. In July 2020 Jansen announced positive results in their clinical trials, resulting in an increase in the share price of Pfizer.
Select publications
References
1958 births
Living people
University of Marburg alumni
Vaccinologists
Microbiologists
COVID-19 researchers
Pfizer people
Wyeth
University of Pennsylvania faculty
GSK plc people
Merck & Co. people
German immunologists
Foreign associates of the National Academy of Engineering
Members of the National Academy of Medicine | Kathrin Jansen | Biology | 997 |
32,313,371 | https://en.wikipedia.org/wiki/Oldstone%20Conference | The Oldstone Conference of 11 to 14 April 1949 was the third of three postwar conferences held to discuss quantum physics; arranged for the National Academy of Sciences by J. Robert Oppenheimer, who was again chairman. It followed the Shelter Island Conference of 1947 and the Pocono Conference of 1948. There were 24 participants; new participants were Robert Christie, Freeman Dyson (whose writings explained Feynman’s ideas), George Placzek, and Hideki Yukawa.
Held at Oldstone-on-the-Hudson in Peekskill, New York, the main talking-point was Richard Feynman’s approach to quantum electrodynamics (QED); Feynman was now (at 30) the leading physicist of his generation.
See also
List of physics conferences
References
Physics conferences
History of science and technology in the United States
Foundational quantum physics
1949 in science
1949 in the United States
1949 conferences
Science events in the United States
April 1949 events in the United States | Oldstone Conference | Physics | 202 |
23,524,651 | https://en.wikipedia.org/wiki/C9H6O2 | {{DISPLAYTITLE:C9H6O2}}
The molecular formula C9H6O2 (molar mass: 146.14 g/mol, exact mass: 146.036779 u) may refer to:
Chromone
Coumarin
1,3-Indandione
Isocoumarin
Phenylpropiolic acid
Molecular formulas | C9H6O2 | Physics,Chemistry | 81 |
2,230,954 | https://en.wikipedia.org/wiki/Shark%20repellent | A shark repellent is any method of driving sharks away from an area. Shark repellents are a category of animal repellents. Shark repellent technologies include magnetic shark repellent, electropositive shark repellents, electrical repellents, and semiochemicals. Shark repellents can be used to protect people from sharks by driving the sharks away from areas where they are likely to harm human beings. In other applications, they can be used to keep sharks away from areas they may be a danger to themselves due to human activity. In this case, the shark repellent serves as a shark conservation method. There are some naturally occurring shark repellents; modern artificial shark repellents date to at least the 1940s, with the United States Navy using them in the Pacific Ocean theater of World War II.
Natural repellents
It has traditionally been believed that sharks are repelled by the smell of a dead shark; however, modern research has had mixed results.
The Pardachirus marmoratus fish (finless sole, Red Sea Moses sole) repels sharks through its secretions. The best-understood factor is pardaxin, acting as an irritant to the sharks' gills, but other chemicals have been identified as contributing to the repellent effect.
In 2017, the US Navy announced that it was developing a synthetic analog of hagfish slime with potential application as a shark repellent.
History
Some of the earliest research on shark repellents took place during the Second World War, when military services sought to minimize the risk to stranded aviators and sailors in the water. Research has continued to the present, with notable researchers including Americans Eugenie Clark, and later Samuel H. Gruber, who has conducted tests at the Bimini Sharklab on the Caribbean island of Bimini, and the Japanese scientist Kazuo Tachibana. The future celebrity chef Julia Child developed shark repellent while working for the Office of Strategic Services.
Initial work, which was based on historical research and studies at the time, focused on using the odor of another dead shark. Efforts were made to isolate the active components in dead shark bodies that repelled other sharks. Eventually, it was determined that certain copper compounds like copper acetate, in combination with other ingredients, could mimic a dead shark and drive live sharks away from human beings in the water. Building on this work, Stewart Springer and others patented a "shark repellent" consisting of a combination of copper acetate and a dark-colored dye to obscure the user.
This shark repellent, known as "Shark Chaser", was long supplied to sailors and aviators of the United States Navy, initially packaged in cake form using a water-soluble wax binder and rigged to life vests. The Navy employed Shark Chaser extensively between 1943 and 1973. It is believed that the composition does repel sharks in some situations, but not in all, with about a 70% effectiveness rating.
On the other hand, Albert Tester questioned the idea that dead shark bodies or chemicals based on them could work as shark repellent. In 1959, he prepared and tested extracts of decaying shark flesh on tiger sharks in Hawaii and blacktip sharks at Enewetak Atoll. Tester found that not only did the dead shark extracts fail to repel any sharks, but several sharks had a "weak or strong attraction" to them. Tester reported a similar failure to repel sharks by a 1959 test at Enewetak of "an alleged shark repellent, supplied by a fisherman, which contained extract of decayed shark flesh as the principal component." Research has continued into the 2000s on using extracts from dead sharks or synthesizing such chemicals.
Research
Since the 1970s, there have been studies of how the Moses sole repels sharks, with Clark and Gruber both studying it. it has not found practical use, however, as the chemicals are perishable, and the repellent had to be injected into the shark's mouth to be effective; in nature the substance is secreted on the skin and is thus ingested by sharks when they bite the sole.
Since the 1980s, there is evidence that surfactants such as sodium lauryl sulfate can act as a shark repellent at concentrations of the order of 100 parts per million. However, this does not meet the desired "cloud" deterrence level of 0.1 parts per million.
There have been validated field tests and studies to confirm the effectiveness of semiochemicals as a shark repellent. From 2005-2010, an extensive study on the effectiveness of semiochemicals as a shark repellent was conducted by scientists from SharkDefense Technologies and Seton Hall University. The study's results were published in the scientific journal Ocean & Coastal Management in 2013. The study concluded that the existence of a putative chemical shark repellent has been confirmed.
As of 2014, SharkDefense partnered with SharkTec LLC to manufacture the semiochemical in a canister as a shark repellent for consumers called Anti-Shark 100.
Recently, SharkDefense used the same semiochemicals found in SharkTec's product to reduce shark by-catch by 71% in a government grant initiative. The government agency NOAA released these findings in a report to Congress.
In 2018 independent tests were carried out on five Shark Repellent technologies using Great white sharks. Only Shark Shield’s Ocean Guardian Freedom+ Surf showed measurable results, with encounters reduced from 96% to 40%. Rpela (electrical repellent technology), SharkBanz bracelet & SharkBanz surf leash (magnetic shark repellent technology) and Chillax Wax (essential oils) showed no measurable effect on reducing shark attacks.
In popular culture
The 1947 Robb White book Secret Sea mentions a copper acetate shark repellent developed by the U.S. Navy.
In Batman: The Movie (1966) there is a scene where an exploding shark jumps from the water and grabs Batman's leg while he is hanging on the Batcopter's ladder, piloted by Robin. Batman tries to punch the shark back to the ocean, but it does not affect the shark. He's handed a canister of Oceanic Bat-Spray, making the shark open its jaw and explode.
In a 2015 a MythBusters episode, the hosts Adam Savage and Jamie Hyneman used an extract of dead sharks, and were able to drive away 10-20 Caribbean reef sharks and nurse sharks in only a few seconds on two occasions. The repellent used consisted of extracts from other species of shark bodies, and sharks did not return for over 5 minutes on both occasions.
See also
Chain mail
Bear spray
References
Pesticides
Shark attack prevention | Shark repellent | Biology,Environmental_science | 1,389 |
16,552,524 | https://en.wikipedia.org/wiki/EDSAC%202 | EDSAC 2 was an early vacuum tube computer (operational in 1958), the successor to the Electronic Delay Storage Automatic Calculator (EDSAC). It was the first computer to have a microprogrammed control unit and a bit-slice hardware architecture.
First calculations were performed on the incomplete machine in 1957. Calculations about elliptic curves performed on EDSAC-2 in the early 1960s led to the Birch and Swinnerton-Dyer conjecture, a Millennium Prize Problem, unsolved as of 2024. And in 1963, Frederick Vine and Drummond Matthews used EDSAC 2 to generate a magnetic anomaly map of the seafloor from data collected in the Indian Ocean by H.M.S. Owen, key evidence that helped support the theory of plate tectonics. EDSAC-2 was decommissioned in 1965, having been superseded by the Titan computer.
References
External links
1950s computers
1958 establishments in England
1958 in computing
Computer-related introductions in 1958
1965 disestablishments in England
Early British computers
One-of-a-kind computers
40-bit computers
University of Cambridge Computer Laboratory
History of the University of Cambridge | EDSAC 2 | Technology | 228 |
6,489,336 | https://en.wikipedia.org/wiki/Louis%20Berger%20Group | Louis Berger (formerly known as Berger Group Holdings) is a full-service engineering, architecture, planning, environmental, program and construction management and economic development firm based in Morristown, New Jersey. Founded in 1953 in Harrisburg, Pennsylvania by Dr. Louis Berger, the firm employed nearly 6,000 employees in more than 50 countries worldwide. The company was acquired by WSP Global in 2018.
The firm provides services to federal, state and local government clients, as well as to international multilateral institutions and to commercial industry. As of September 2011, Louis Berger ranked as the third largest USAID private-sector partner, and was ranked #25 in 2015 among U.S. design firms in terms of total firm revenue by Engineering News-Record.
The company has suffered setbacks in recent years with settlement of fraud charges for contracts in Afghanistan; admission of criminal responsibility to Foreign Corrupt Practices Act violations in a settlement with the US Department of Justice for bribery of governments in Asia; and a debarment by the World Bank for corrupt practices. In 2019, the National Transportation Safety Board determined that Louis Berger's inadequate peer review of the design contributed to the Florida International University pedestrian bridge collapse. They were also criticized for failure to identify the significance of structural cracking and not preparing a remedial plan to address it.
History
Background
Louis Berger was founded in 1953 by Louis Berger in Harrisburg, Pennsylvania. Born in 1914 in Lawrence, Massachusetts, Dr. Berger graduated from Tufts College in 1936 with a degree in civil engineering, and earned a master’s in soils and geology from Massachusetts Institute of Technology in 1940. In 1942, Dr. Berger joined the United States Coast Guard where he designed waterfront facilities along the Mississippi River and commanded a Coast Guard base in Greenland. Upon returning from active duty, he earned his PhD in soil mechanics from Northwestern University and joined the teaching faculty at the Pennsylvania State University. In 1952, Dr. Berger left his position at Pennsylvania State University to form the engineering consulting firm that would later become Louis Berger.
Fredric S. Berger, son of the company's founder, Dr. Louis Berger, was involved with the company since 1972 and served as chairman of Louis Berger Group from 2007 until his passing in April 2015. Mr. Berger held a bachelor's in economics from Tufts University and a master of science degree in civil engineering from the Massachusetts Institute of Technology. Mr. Berger was a founding member of the American University of Afghanistan and served on the university's board from 2004 to 2015. In 2013, Mr. Berger was appointed to advisory boards for the U.S. Institute of Peace and the U.S. Trade and Development Agency.
Early years
The firm’s first major projects included design on the Pennsylvania Turnpike, the first turnpike in the U.S., and on I-80 between Denville and Netcong, the first interstate road in the state of New Jersey The firm also designed the Herat-Islam Qala Highway in Afghanistan in 1965.
International development work
Louis Berger began its first international project in 1959 when the firm was selected by USAID and the U.S. Army Corps of Engineers Gulf District to design a 435-mile highway between Yangon and Mandalay in Myanmar. The project was initially rejected by the Burmese government as proposed by the Corps of Engineers, but Louis Berger was able to design the project using more economical alternatives.
In December 2010, the Discovery Science Channel production team filmed thirty hours of footage of the works for the construction of a new bridge over the Sava River in Belgrade, Serbia.
In 2012, Louis Berger completed work on the Juba-Nimule Road in South Sudan under the Sudan Infrastructure Services Project. The road was the first paved highway in South Sudan and links the South Sudanese capital to the town of Nimule on the Ugandan border.
Organization
Louis Berger consists of three operating companies which include a United States unit (formerly known as Louis Berger Group), an international unit, and a services unit that provides base logistics and operations support, global operations and maintenance, turnkey power solutions and fueling and facility services. Headquartered in Morristown, New Jersey, Louis Berger manages its regional operations out of offices in Washington D.C., France, United Arab Emirates, India and Panama. The company was acquired by the Canada-based WSP Global in 2018 for $400 million.
Industry rankings
Louis Berger was ranked #25 among U.S. design firms in 2015 based on total firm revenue by Engineering News-Record and #10 among Program Management firms The firm also ranked #37 among Environmental firms in 2014.
Criticisms
Afghanistan and Iraq
In November 2010, Louis Berger agreed to pay a record $69.3 million to settle charges of fraud against the government brought under the False Claims Act. The case, filed by a whistleblower, alleged that the company billed the government for internal costs unrelated to its rebuilding contracts in Afghanistan.
Protection payments to Taliban
According to the lawsuit, filed in December 2019 in the D.C. District Court on behalf of Gold Star families, some U.S. contractors involved in Afghanistan's reconstruction projects, including Louis Berger Group, made illegal "protection payments" to the Taliban, funding a "Taliban-led terrorist insurgency" that killed or wounded thousands of Americans in Afghanistan. In 2009, then-Secretary of State Hillary Clinton said that the "protection money" was "one of the major sources of funding for the Taliban."
Bribery in India, Vietnam, Indonesia, and Kuwait
Between 1998 and 2010, executives at the company paid bribes amounting to $3.9 million to government officials in India, Indonesia, Vietnam and Kuwait to win business in violation of the Foreign Corrupt Practices Act. A settlement agreement between the company with the US Department of Justice was announced in July 2015, in which the company admitted criminal responsibility and agreed to pay a penalty of $17.1 million. The inquiry into the company's activities in Vietnam uncovered corrupt payments to government officials in the Third Rural Transport and Da Nang Priority Infrastructure Investment Projects, both World Bank funded projects. The World Bank imposed a one-year debarment on firm for engaging in "corrupt practices" in February 2015.
Key Projects
Roads and Bridges
Dragon River Bridge, Vietnam
Bang Na Expressway, Thailand
Kabul-Kandahar Highway, Afghanistan
Third Bridge over Panama Canal, Panama
Ada Bridge, Serbia
Pennsylvania Turnpike, Pennsylvania
Juba-Nimule Road, South Sudan
Ohmi-Odori Bridge, Japan
Aviation
Suvarnabhumi Airport
Sir Seewoosagur Ramgoolam International Airport
Ovda Air Base
Queen Alia International Airport
Rail
Kamalapur railway station
Doha Metro
MRT Blue Line
Mumbai Monorail
North South Railway (Saudi Arabia)
Maritime
Port at Lekki
Port of Santos
Other projects
Lincoln Memorial Reflecting Pool
Kajaki Dam
See also
Hermanos Serdán International Airport
Kabul-Kandahar Highway
Pennsylvania Turnpike
Third Bridge over Panama Canal
References
Engineering consulting firms of the United States
International engineering consulting firms
Construction and civil engineering companies of the United States
Construction and civil engineering companies established in 1953
1953 establishments in Pennsylvania | Louis Berger Group | Engineering | 1,420 |
2,148,212 | https://en.wikipedia.org/wiki/Sanctum%20sanctorum | The Latin phrase sanctum sanctorum is a translation of the Hebrew term קֹדֶשׁ הַקֳּדָשִׁים (Qṓḏeš HaQŏḏāšîm), literally meaning Holy of Holies, which generally refers in Latin texts to the holiest place of the Ancient Israelites, inside the Tabernacle and later inside the Temple in Jerusalem, but the term also has some derivative use in application to imitations of the Tabernacle in church architecture.
The plural form sancta sanctorum is also used, arguably as a synecdoche, referring to the holy relics contained in the sanctuary. The Vulgate translation of the Bible uses sancta sanctorum for the Holy of Holies. Hence the derivative usage to denote the Sancta Sanctorum chapel in the complex of the Archbasilica of Saint John Lateran, Rome.
In Hinduism, a temple's innermost part where the Murti of the deity is kept forms the Garbhagriha, also referred to as a sanctum sanctorum.
Etymology
The Latin word sanctum is the neuter form of the adjective "holy", and sanctorum its genitive plural. Thus the term sanctum sanctorum literally means "the holy [place/thing] of the holy [places/things]", replicating in Latin the Hebrew construction for the superlative, with the intended meaning "the most holy [place/thing]".
Use of the term in modern languages
The Latin word sanctum may be used in English, following Latin, for "a holy place", or a sanctuary, as in the novel Jane Eyre (1848) which refers to "the sanctum of school room".
Romance languages tend to use the form sancta sanctorum, treating it as masculine and singular. E.g., the Spanish dictionary of the Real Academia Española admits sanctasanctórum (without the space and with an accent) as a derivative Spanish noun denoting both the Holy of Holies in the Temple in Jerusalem, any secluded and mysterious place, and something that a person holds in the highest esteem.
The term is still often used by Indian writers for the garbhagriha or inner shrine chamber in Hindu temple architecture, after being introduced by British writers in the 19th century.
German Catholic processions
Some regional branches of the Catholic Church, e. g. Germans, are wont to refer to the Blessed Sacrament, when adored in the tabernacle or in exposition or procession (e.g. on Corpus Christi), as the Holy of Holies. By custom, It is adored with genuflection; with a double genuflection, that is a short moment of kneeling on both knees, if in exposition; in the procession this ritual may be nonrigoristically alleviated, but at least a simple genuflection is appropriate when It is elevated by the priest for blessing or immediately after transsubstantiation. Personnel in uniform — which in Germany includes student corporations — give the military salute when passing by or in the moment of elevation.
The "enclosed house" of Hindu temple architecture
The garbhagriha in Hindu temple architecture (a shrine inside a temple complex where the main deity is installed in a separate building by itself inside the complex) has also been compared to a "sanctum sanctorum" in texts on Hindu temple architecture, though the Sanskrit term actually means "enclosed house" or "the deep interior of the house". However, some Indian English authors seem to have translated the Sanskrit term literally as "womb house".
See also
References
Vulgate Latin words and phrases
Superlatives in religion
Sacral architecture | Sanctum sanctorum | Engineering | 756 |
57,441,697 | https://en.wikipedia.org/wiki/Mechanically%20gradient%20polymers | Polymer gradient materials (PGM) are a class of polymers with gradually changing mechanical properties along a defined direction creating an anisotropic material. These materials can be defined based upon the direction and the steepness of the gradient used and can display gradient or graded transitions. A wide range of methods can be used to create these gradients including gradients in reinforcing fillers, cross-link density or porosity to name a few. 3D printing has been used to combine several of these methods in one manufacturing technique.
These materials can be inspired by nature where mechanical gradients are used commonly to improve interfaces between two dissimilar surfaces. When two materials that have different moduli are connected together in a bilayer, this can create a weak junction, whereas a mechanical gradient can reduce the stress and strain of the connection. In contrast, a butt joint that gives a junction between materials with little to no gradient has been shown to be weaker than the homogenous components.
Mechanically gradient polymers are not manufactured as extensively as can be found in nature, and there can also be unintended gradients during the manufacturing process. Materials are not always completely uniform despite the intentions of the manufacturer, and these unintended gradients may weaken the material rather than improve. Therefore, mechanical gradients must be properly applied to the particular application to prevent introduction of instabilities.
Methods
Gradient in reinforcing filler
Reinforcing fillers such as carbon nanotubes that have high mechanical moduli have been used commonly to create polymer composites with high strength and toughness. Since the modulus and filler amount are linked, by varying the amount of filler across the polymer the modulus will similarly change. Additionally, since long nanofillers create anisotropic moduli, if the direction of the nanofiller could be modified along the length of the polymer, the modulus gradient could also be tuned in this manner.
Gradient in crosslink density
A common approach to increasing the mechanical strength of polymers includes changing the crosslinking density of the polymer. Crosslinks connect the polymer chains creating a web that resists deformation. Therefore, increasing the crosslinking density in a section of a polymer will increase the modulus in this location. This can be used to create a mechanical gradient if the crosslinking density changes across the polymer. A common approach to achieving this is using a photopolymerization process which with changes in UV exposure you can change the degree of crosslinking or polymerization in the area exposed. In a similar manner, the amount of initiator or crosslinker could be varied across the sample creating a similar effect.
Gradient in porosity
Porosity can be used to decrease the modulus of a polymer as seen in polymer foams, and as seen in bone, a change in porosity and therefore density can also be used to create a mechanical gradient along its cross-section.
Applications
Nature
There are many examples in nature where soft tissue and hard surfaces are connected by a mechanical gradient to improve the fracture and impact resistance. Examples include mussels that connect to hard rocks by the mussel byssus which connects back to the soft muscle of the foot. A more extreme example is the squid beak which has an extremely hard tip required to kill and dismember its prey which connects back to the soft flesh of the body of the squid. Without the mechanically gradient in the beak, the squid would be unable to withstand the high impacts despite its hardness since it would break off from the body at the junction between the materials.
Biomedical Implants
As mentioned above, many systems in nature incorporate mechanical gradients, and similarly for biomedical implants these gradients can be useful. Many implants are stiff and can cause damage to the surrounding tissues due to this difference in stiffness. This is a problem for instance in microelectrodes implanted into the brain which is extremely soft. The damage caused can create a buildup of fibrous tissue which can then interfere with the signal between the electrode and the brain. Similarly, in knee and hip implants, there is a need for high integration between the strong bone and the cartilage and tissue. Otherwise problems such as stress shielding can occur where the bone degenerates due to the implant having too strong of a modulus.
References
Polymers | Mechanically gradient polymers | Chemistry,Materials_science | 879 |
25,161,898 | https://en.wikipedia.org/wiki/Sony%20TV8-301 | The TV8-301 was a small black-and-white television made by Sony. It is notable for being the world's first non-projection type all-transistor television. It had an eight-inch screen. It was also portable, having a bay in the back for two 6-volt lead–acid batteries. It was priced high, as it was innovative in many ways, so, to the average consumer it was something of a luxury item and not a practical buy. Additionally, this television was rather prone to malfunction, which led to it being called Sony's "frail little baby". Released on the market in 1960, it was discontinued in 1962.
Technical data
Transistors: 23 (silicon and germanium)
Diodes: 15 + 2 high-voltage (17)
References
External links
TV8-301
Image of B&W TV
Television technology
Sony products
Vacuum tube displays
Television sets | Sony TV8-301 | Technology | 190 |
1,857,696 | https://en.wikipedia.org/wiki/JDOM | JDOM is an open-source Java-based document object model for XML that was designed specifically for the Java platform so that it can take advantage of its language features. JDOM integrates with Document Object Model (DOM) and Simple API for XML (SAX), supports XPath and XSLT. It uses external parsers to build documents. JDOM was developed by Jason Hunter and Brett McLaughlin starting in March 2000. It has been part of the Java Community Process as JSR 102, though that effort has since been abandoned.
Examples
Suppose the file "foo.xml" contains this XML document:
<shop name="shop for geeks" location="Tokyo, Japan">
<computer name="iBook" price="1200$" />
<comic_book name="Dragon Ball vol 1" price="9$" />
<geekyness_of_shop price="priceless" />
</shop>
One can parse the XML file into a tree of Java objects with JDOM, like so:
SAXBuilder builder = new SAXBuilder();
Document doc = builder.build(new FileInputStream("foo.xml"));
Element root = doc.getRootElement();
// root.getName() is "shop"
// root.getAttributeValue("name") is "shop for geeks"
// root.getAttributeValue("location") is "Tokyo, Japan"
// root.getChildren() is a java.util.List object that contains 3 Element objects.
In case you do not want to create the document object from any file or any input stream, you can create the document object against the element.
Element root = new Element("shop"); // here <shop></shop> is the root
Document doc = new Document(root); // create a new document with the supplied element as the root
As a converse, one can construct a tree of elements, then generate an XML file from it, as in the following example:
Element root = new Element("shop");
root.setAttribute("name", "shop for geeks");
root.setAttribute("location", "Tokyo, Japan");
Element item1 = new Element("computer");
item1.setAttribute("name", "iBook");
item1.setAttribute("price", "1200$");
root.addContent(item1);
// perform similar steps for other elements
XMLOutputter outputter = new XMLOutputter();
outputter.output(new Document(root), new FileOutputStream ("foo2.xml"));
References
External links
Java (programming language) libraries
Document Object Model
XML-based standards | JDOM | Technology | 625 |
47,596,170 | https://en.wikipedia.org/wiki/Trelagliptin | Trelagliptin (trade name Zafatek) is a pharmaceutical drug used for the treatment of type 2 diabetes (diabetes mellitus).
Indications
It is a highly selective dipeptidyl peptidase-4 inhibitor that is typically used as an add on treatment when the first line treatment of metformin is not achieving the expected glycemic goals; though it has been approved for use as a first line treatment when metformin cannot be used.
Biochemistry
DPP-4 inhibitors activate T-cells and are more commonly known as T-cell activation antigens (specifically CD26). Chemically, it is a fluorinated derivative of alogliptin.
Development
Formulated as the salt trelagliptin succinate, it was approved for use in Japan in March 2015. Takeda, the company that developed trelagliptin, chose to not get approval for the drug in the US and EU. The licensing rights that Takeda purchased from Furiex Pharmaceuticals for DPP-4 inhibitors included a clause specific to development of this drug in the US and EU. The clause required that all services done for phase II and phase III clinical studies in the US and EU be purchased through Furiex. Takeda chose to cease development of this drug in the US and EU because of the high costs quoted by Furiex for these services. Gliptins have been on the market since 2006 and there are 8 gliptins currently registered as drugs (worldwide). Gliptins are an emerging market and are thus being developed at an increasing rate; there are currently two gliptins in advanced stages of development that are expected to be on the market in the coming year.
Gliptins are thought to have cardiovascular protective abilities though the extent of these effects is still being studied. They are also being studied for the ability that this class of drugs has at promoting B-cell survival.
Administration and dosing
Similar drugs in the same class as trelagliptin are administered once daily while trelagliptin is administered once weekly. Alogliptin (Nesina) is the other major DPP-4 inhibitor on the market. It is also owned by Takeda and is administered once daily. A dosing of once per week is advantageous as a reduction in the frequency of required dosing is known to increase patient compliance.
A recent meta-analysis published by Dutta et. al. highlighted the good glycaemic efficacy and safety of this molecule as compared to peer DPP4 inhibitors which have to be taken daily like alogliptin, sitagliptin, linagliptin, teneligliptin, anagliptin or vildagliptin, having an advantage of reducing the monthly pill count from 30 to 4.
Brand names
In Bangladesh it is marketed under the trade name Wedica.
References
Dipeptidyl peptidase-4 inhibitors
Pyrimidinediones
Fluoroarenes
Piperidines
Nitriles | Trelagliptin | Chemistry | 614 |
11,955,434 | https://en.wikipedia.org/wiki/International%20Maritime%20Hall%20of%20Fame | The International Maritime Hall of Fame is a museum honouring people who have made a large contribution in the maritime field. The hall of fame inducted its first set of honorees in or about 1994. The hall is sponsored by the Maritime Association of the Port of New York and New Jersey.
Inductees
For 1994-2008 inductees, see footnote
Malcom McLean - creator of international standard shipping containers.
2000
See footnote
2001
See footnote
2003
Christopher L. Koch, president and CEO, World Shipping Council
Olav K. Rakkenes, former president and CEO, Atlantic Container Line
Charles G. Raymond, chairman, CEO and president, Horizon Lines
Paul F. Richardson, principal, Paul F. Richardson & Associates
Henk Van Hemmen, president emeritus, Martin, Ottaway Van Hemmen & Dolan Inc.:
John Arnold Witte, Sr., CEO and president, Donjon Marine Co., Inc.
2009
See footnote
2010
See footnote
2011
See footnote
2012 & 2013
See footnote
2014
Peter Friedmann, executive director, Agriculture Transportation Coalition
Jorn Hinge, president and chief executive officer, United Arab Shipping Company (S.A.G.)
Carol Notias Lambos, partner, The Lambos Firm, LLP
Lambros C. Varnavides, managing director and global head of shipping, Royal Bank of Scotland
Wolf von Appen, president, Ultramar Agencia Maritima Ltda., and chairman, Grupo Ultramar
2016
C. Duff Hughes, president, The Vane Brothers Company
Simeon P. Palios, chairman and CEO, Diana Shipping, Inc.
Robert P. (Rob) Kusiciel, vice president of logistics & transportation, Center of Excellence, Honeywell International, Inc.
William (Bill) Payne, vice chairman, NYK Line (NA), Inc. and vice president, NYK Ports, LLC.
Christopher J. Wiernicki, chairman, CEO and president, American Bureau of Shipping, Inc.
2017
Jean-Jacques (JJ) Ruest, executive vice-president and chief marketing officer, Canadian National Railway Company
Harley V. Franco, chairman and chief executive officer, Harley Marine Services
Angeliki N. Frangou, chairman and chief executive officer, Navios Maritime Holdings Inc.
James C. McKenna, president and chief executive officer, Pacific Maritime Association
Madeleine Paquin, president and chief executive officer, Logistec Corporation
2018
Michael A. Jordan, founding principal and technical direction, Liftech
Donato Caruso, of counsel, The Lambos Firm, LLP
Adam M. Goldstein, vice chairman, Royal Caribbean Cruises Ltd
Juergen Pump, president for North America, Hamburg Süd
2019
Harold J. Daggett, international president, International Longshoremen’s Association, AFL-CIO
George Economou, founder, chairman, CEO, DryShips Inc.
John F. Reinhart, chief executive officer, executive director, Virginia Port Authority
Rodolphe J. Saadé, chairman and chief executive officer, CMA CGM S.A.
Richard S. (Rich) Weeks, president and chief executive officer, Weeks Marine, Inc.
2020
Lisa Lutoff-Perlo, president and CEO, Celebrity Cruises Inc.
James R. Mara, president emeritus, Metropolitan Marine Maintenance Contractors’ Association
James I. Newsome III, president and CEO, South Carolina Ports Authority
Dr. Nikolas P. Tsakos, president and CEO, Tsakos Energy Navigation Corp.
Lois K. Zabrocky, president and CEO, International Seaways Inc.
2021
James Angelo Ruggieri, Eur Ing, General Machine Corp.
Larry Wilkerson, United States Coast Guard
Similar Halls
Delaware Maritime Hall of Fame
National Maritime Hall of Fame
Footnotes
External links
International Maritime Hall of Fame Awards 1994-2008
Port of New York and New Jersey
Science and technology halls of fame
Maritime
Maritime museums in the United States
Maritime history organizations | International Maritime Hall of Fame | Technology | 796 |
33,151,276 | https://en.wikipedia.org/wiki/4-Vinylphenol | 4-Vinylphenol is an organic compound with the formula C2H3C6H4OH. It is the most studied of the three isomeric vinylphenols. It is a white volatile solid.
Production
Upon contact with iron oxide at 500 °C, 4-ethylphenol undergoes dehydrogenation to give 4-vinyllphenol:
C2H5C6H4OH → C2H3C6H4OH + H2
Natural occurrence
It is found in wine and beer. It is produced by the spoilage yeast Brettanomyces. When it reaches concentrations greater than the sensory threshold, it can give the wine aromas described as barnyard, medicinal, band-aids, and mousy. In wine, 4-vinylphenol can react with other molecules, such as anthocyanidins, to produce new chemical compounds. In white wines vinylphenols are dominant (4-vinylphenol 70-1 150 μg/L, 4-vinylguaiacol 10-490 μg/L) whereas, in red wines, it is the corresponding ethyl phenols.
Biosynthesis
The enzyme cinnamate decarboxylase converts p-coumaric acid to 4-vinylphenol. 4-Vinylphenol is further reduced to 4-ethylphenol by the enzyme vinyl phenol reductase. Coumaric acid is sometimes added to microbiological media, enabling the positive identification of Brettanomyces by smell.
See also
4-Ethylguaiacol
Yeast in winemaking
Wine fault
Wine chemistry
Poly-4-vinylphenol (polyvinylphenol or PVP) is a plastic structurally similar to polystyrene.
References
Natural phenols
Vinyl compounds
4-Hydroxyphenyl compounds | 4-Vinylphenol | Chemistry | 383 |
28,357,829 | https://en.wikipedia.org/wiki/Time%20evolution%20of%20integrals | Within differential calculus, in many applications, one needs to calculate the rate of change of a volume or surface integral whose domain of integration, as well as the integrand, are functions of a particular parameter. In physical applications, that parameter is frequently time t.
Introduction
The rate of change of one-dimensional integrals with sufficiently smooth integrands, is governed by this extension of the fundamental theorem of calculus:
The calculus of moving surfaces provides analogous formulas for volume integrals over Euclidean domains, and surface integrals over differential geometry of surfaces, curved surfaces, including integrals over curved surfaces with moving contour boundaries.
Volume integrals
Let t be a time-like parameter and consider a time-dependent domain Ω with a smooth surface boundary S. Let F be a time-dependent invariant field defined in the interior of Ω. Then the rate of change of the integral
is governed by the following law:
where C is the velocity of the interface. The velocity of the interface C is the fundamental concept in the calculus of moving surfaces. In the above equation, C must be expressed with respect to the exterior normal. This law can be considered as the generalization of the fundamental theorem of calculus.
Surface integrals
A related law governs the rate of change of the surface integral
The law reads
where the -derivative is the fundamental operator in the calculus of moving surfaces, originally proposed by Jacques Hadamard. is the trace of the mean curvature tensor. In this law, C need not be expression with respect to the exterior normal, as long as the choice of the normal is consistent for C and . The first term in the above equation captures the rate of change in F while the second corrects for expanding or shrinking area. The fact that mean curvature represents the rate of change in area follows from applying the above equation to since is area:
The above equation shows that mean curvature can be appropriately called the shape gradient of area. An evolution governed by
is the popular mean curvature flow and represents steepest descent with respect to area. Note that for a sphere of radius R,
, and for a circle of radius R,
with respect to the exterior normal.
Surface integrals with moving contour boundaries
Suppose that S is a moving surface with a moving contour γ. Suppose that the velocity of the contour γ with respect to S is c. Then the rate of change of the time dependent integral:
is
The last term captures the change in area due to annexation, as the figure on the right illustrates.
References
Differential calculus
Integral calculus | Time evolution of integrals | Mathematics | 508 |
73,825,961 | https://en.wikipedia.org/wiki/Network%20Coordinate%20System | A Network Coordinate System (NC system) is a system for predicting characteristics such as the latency or bandwidth of connections between nodes in a network by assigning coordinates to nodes. More formally, It assigns a coordinate embedding to each node in a network using an optimization algorithm such that a predefined operation estimates some directional characteristic of the connection between node and .
Uses
In general, Network Coordinate Systems can be used for peer discovery, optimal-server selection, and characteristic-aware routing.
Latency Optimization
When optimizing for latency as a connection characteristic i.e. for low-latency connections, NC systems can potentially help improve the quality of experience for many different applications such as:
Online Games
Forming game groups such that all the players are close to each other and thus have a smoother overall experience.
Choosing servers as close to as many players in a given multiplayer game as possible.
Automatically routing game packets through different servers so as to minimize the total latency between players who are actively interacting with each other in the game map.
Content delivery networks
Directing a user to the closest server that can handle a request to minimize latency.
Voice over IP
Automatically switch relay servers based on who is talking in a few-to-many or many-to-many voice chat to minimize latency between active participants.
Peer-to-peer networks
Can use the latency-predicting properties of NC systems to do a wide variety of routing optimizations in peer-to-peer networks.
Onion routing networks
Choose relays such as to minimize the total round trip delay to allow for a more flexible tradeoff between performance and anonymity.
Physical positioning
Latency correlates with the physical distances between computers in the real world. Thus, NC systems that model latency may be able to aid in locating the approximate physical area a computer resides in.
Bandwidth Optimization
NC systems can also optimize for bandwidth (although not all designs can accomplish this well). Optimizing for high-bandwidth connections can improve the performance of large data transfers.
Sybil Attack Detection
Sybil attacks are of much concern when designing peer-to-peer protocols. NC systems, with their ability to assign a location to the source of traffic can aid in building systems that are Sybil-resistant.
Design Space
Landmark-Based vs Decentralized
Almost any NC system variant can be implemented in either a landmark-based or fully decentralized configuration. Landmark-based systems are generally secure so long as none of the landmarks are compromised, but they aren't very scalable. Fully decentralized configurations are generally less secure, but they can scale indefinitely.
Euclidean Embedding
This design assigns a point in -dimensional euclidean space to each node in the network and estimates characteristics via the euclidean distance function where represents the coordinate of node .
Euclidean Embedding designs are generally easy to optimize.
The optimization problem for the network as a whole is equivalent to finding the lowest energy state of a spring-mass system where the coordinates of the masses correspond to the coordinates of nodes in the network and the springs between the masses represent measured latencies between nodes.
To make this optimization problem function work in a decentralized protocol, each node exchanges its own coordinates with those of a fixed set of peers and measures the latencies to those peers, simulating a miniature spring-mass system where all the masses representing the coordinates of the peers and each mass is connected via a single spring to the node's own "mass" which when simulated, gives a more optimal value for the node's coordinate. All these individual updates allow the network as a whole to form a predictive coordinate space by collaboratively.
The laws of Euclidean space require certain characteristics of the distance function to hold true, such as symmetry (measuring from should give the same result as from ) and the triangle inequality . No real-world network characteristics completely satisfy these laws, but some do more than others and NC systems using euclidean embedding are somewhat accurate when run on datasets containing violations of these laws.
Notable Papers: GNP, PIC Vivaldi, Pharos
Matrix Factorization
The matrix factorization design imagines the entire network as represented by an incomplete matrix where is the total number of nodes in the network, and any element of the matrix at the intersection between row and column of the matrix represents a directional latency measurement from node to node . The goal is to estimate the numbers in the unfilled squares of the matrix using the squares that are already filled in, i.e. performing matrix completion.
To estimate a specific latency between two nodes, this method uses the dot product where / represents a point in a -dimensional inner product space.
NC system designs using matrix factorization are generally more complicated than their euclidean counterparts.
In the centralized variant, matrix completion can be performed directly on a set of landmarks which have measured latency to every other landmark in a set, thus creating a complete matrix representing the landmark network. This matrix can then be factored on a single computer using non-negative matrix factorization (NNMF) into two matrices and such that . Since matrix multiplication is essentially doing the dot product for each row and column of the input matrices, coordinates for each landmark can be represented by two "in" and "out" vectors ( and ) taken respectively from the th row of and the th column of . With this, latencies between two landmarks can be approximates by a simple dot product: . Any node that wants to figure out their own coordinates can simply measure the latency to some subset of all the landmarks, re-create a complete matrix using the landmark's coordinates, and then perform NNMF to calculate their own coordinate. This coordinate can then be used with any other node (landmark or otherwise) to estimate latency to any other coordinate that was calculated via the same set of landmarks.
The decentralized variant is decidedly simpler. For a given node, the goal is to minimize the absolute difference (or squared difference) between the measured latencies to the peers and the predicted latencies to the peers. The predicted latency is given by the same equation where is the outgoing vector of node and is the incoming vector of node . This goal (or loss function) can then be minimized using stochastic gradient descent with line search.
Notable Papers: IDES, Phoenix, DMFSGD
Tensor Factorization
Notable Papers: TNDP Leverage Sampling + Personal Devices
Relative Coordinates
Notable Papers: RMF
Alternatives
Network Coordinate Systems are not the only way to predict network properties. There are also methods such as iPlane and iPlane Nano which take a more analytical approach and try to mechanistically simulate the behavior of internet routers to predict by what route some packets will flow, and thus what properties a connection will have.
In The Wild
Vuze - BitTorrent Client
References
Computer networking
Peer-to-peer computing | Network Coordinate System | Technology,Engineering | 1,396 |
11,421,483 | https://en.wikipedia.org/wiki/RyeE%20RNA | The CyaR RNA (formerly known as RyeE RNA) non-coding RNA was identified in a large scale screen of Escherichia coli and was called candidate 14. The exact 5′ and 3′ ends of this RNA are uncertain. This gene lies between yegQ and orgK in E. coli. This small RNA was shown to be bound by the Hfq protein. This RNA has been renamed as CyaR for (cyclic AMP-activated
RNA). It has been shown that the CyaR RNA acts as a repressor of the porin OmpX. It has also been shown that cyaR expression is tightly controlled by the cyclic AMP receptor protein, CRP.
A comparative genomics approach was able to detect and verify the additional targets ptsI, sdhA and yobF.
See also
RydB RNA
RyhB RNA
RyeB RNA
References
External links
Non-coding RNA | RyeE RNA | Chemistry | 185 |
3,065,512 | https://en.wikipedia.org/wiki/Hyaline | A hyaline substance is one with a glassy appearance. The word is derived from , and .
Histopathology
Hyaline cartilage is named after its glassy appearance on fresh gross pathology. On light microscopy of H&E stained slides, the extracellular matrix of hyaline cartilage looks homogeneously pink, and the term "hyaline" is used to describe similarly homogeneously pink material besides the cartilage. Hyaline material is usually acellular and proteinaceous. For example, arterial hyaline is seen in aging, high blood pressure, diabetes mellitus and in association with some drugs (e.g. calcineurin inhibitors). It is bright pink with PAS staining.
Ichthyology and entomology
In ichthyology and entomology, hyaline denotes a colorless, transparent substance, such as unpigmented fins of fishes or clear insect wings.
Botany
In botany, hyaline refers to thin and translucent plant parts, such as the margins of some sepals, bracts and leaves.
See also
Hyaline arteriolosclerosis
Hyaloid canal, which passes through the eye
Hyalopilitic
Hyaloserositis
Infant respiratory distress syndrome, previously known as hyaline membrane disease
References
Taber's Cyclopedic Medical Dictionary, 19th Edition. Donald Venes ed. 1997 F.A. Davis. Page 1008.
Histopathology
Fungal morphology and anatomy | Hyaline | Chemistry | 306 |
1,231,204 | https://en.wikipedia.org/wiki/Constructive%20quantum%20field%20theory | In mathematical physics, constructive quantum field theory is the field devoted to showing that quantum field theory can be defined in terms of precise mathematical structures. This demonstration requires new mathematics, in a sense analogous to classical real analysis, putting calculus on a mathematically rigorous foundation. Weak, strong, and electromagnetic forces of nature are believed to have their natural description in terms of quantum fields.
Attempts to put quantum field theory on a basis of completely defined concepts have involved most branches of mathematics, including functional analysis, differential equations, probability theory, representation theory, geometry, and topology. It is known that a quantum field is inherently hard to handle using conventional mathematical techniques like explicit estimates. This is because a quantum field has the general nature of an operator-valued distribution, a type of object from mathematical analysis. The existence theorems for quantum fields can be expected to be very difficult to find, if indeed they are possible at all.
One discovery of the theory that can be related in non-technical terms, is that the dimension d of the spacetime involved is crucial. Notable work in the field by James Glimm and Arthur Jaffe showed that with d < 4 many examples can be found. Along with work of their students, coworkers, and others, constructive field theory resulted in a mathematical foundation and exact interpretation to what previously was only a set of recipes, also in the case d < 4.
Theoretical physicists had given these rules the name "renormalization," but most physicists had been skeptical about whether they could be turned into a mathematical theory. Today one of the most important open problems, both in theoretical physics and in mathematics, is to establish similar results for gauge theory in the realistic case d = 4.
The traditional basis of constructive quantum field theory is the set of Wightman axioms. Konrad Osterwalder and Robert Schrader showed that there is an equivalent problem in mathematical probability theory. The examples with d < 4 satisfy the Wightman axioms as well as the Osterwalder–Schrader axioms . They also fall in the related framework introduced by Rudolf Haag and Daniel Kastler, called algebraic quantum field theory. There is a firm belief in the physics community that the gauge theory of C.N. Yang and Robert Mills (the Yang–Mills theory) can lead to a tractable theory, but new ideas and new methods will be required to actually establish this, and this could take many years.
External links
Axiomatic quantum field theory
Functional analysis | Constructive quantum field theory | Mathematics | 505 |
41,242,602 | https://en.wikipedia.org/wiki/Opon%20If%C3%A1 | An ọpọ́n Ifá is a divination tray used in traditional African and Afro-American religions, notably in the system known as Ifá and in Yoruba tradition more broadly. The etymology of opon, literally meaning "to flatter", explains the artistic and embellished nature of the trays, as they are meant to praise and acknowledge the noble work of the Babalawo (diviners). The etymology of the term Ifá, however, has been a subject of debate. Ifá may be considered an orisha, or a Yoruba god — specifically, the god of divination Orula. Conversely, some scholars have referred to Ifá merely as the "great consulting oracle" as opposed to a god or a deity, without any divine connotations.
Opon Ifá are typically made by wood carvers who specialize in the trays, and are made with designs per request of the patron babalawo or by the carver's own accord. The emphasis on the tray's design is not only due to their "flattering" nature, but also because of their functionality during consultation. Different carvers employ various aesthetic styles within West Africa and in the African diaspora, but most carvers are able to trace their influence back to Oyo, in present-day Nigeria.
During divination consultations, the opon Ifá is used by a babalawo to communicate with Ifá, who is able to identify the causes and solutions to personal and collective problems, and to restore harmony with the spirits. An intermediary orisha, Esu, serves as the messenger between the babalawo and Ifá, as the two spirits are close companions to each other. In conjunction with other divine instruments such as an iroke Ifá (diviner's tapper), ikin Ifá (sacred palm or kola nuts) or opele Ifá (divination chain), and iyerosun (divining powder), the opon Ifá is used to determine the odu, or verses, associated with a patron's particular predicament. Once an odu is revealed by Ifá, the babalawo then elucidates a solution that is embedded in the archetypal story described in the specific odu.
Structure
Opon Ifá are wooden, generally between 15 and 46 centimeters (6 and 18 inches) in diameter, and are flat and usually circular; however, rectangular, semi-circular, and approximately square specimens have also been observed. The trays exhibit a raised outer perimeter – often embellished with carved figures, objects, and abstract geometric designs. The artistic intricacy of the peripheral carvings are a status marker among babalowos, and suggest their importance to clients. The top of the tray is called the "head" or the oju opon, and the bottom is conversely called the "feet" or the ese opon. Typically, the head is adorned with a carved depiction of Esu, the messenger of Ifá. Certain trays may have additional representations of Esu, and trays with two, four, eight, and even sixteen faces have been studied. In such cases, the "head" of the tray may be designated by cowries. The cowries are also used to spread the sacred divining powder, iyerosun.
The peripheral markings of the opon Ifá are functional as well as ornamental. They serve to divide the perimeter into nine different sections that contribute symbolic significance during consultations. Each section is named after one of nine ancient and influential diviners. In a divination reading, the babalowo sits facing east with the opon Ifá in front of them, such that the "feet" of the tray is closest to them. In this orientation, the oju opon ("face of the tray"), ese opon ("feet of the tray"), ona kanran ("straight path"), and the ona murun ("direct path") are respectively situated on the east, west, south and north sides of the tray's perimeter. On the diagonals from these cardinal directions are four additional sections or diviners: alaselosi ("the one who implements with the left") to the northeast, alabolotun ("the one who proposes with the right") to the southeast, afurukeresayo ("the one who has a diviner's fly-whisk and is happy") to the northwest, and ajiletepowo ("an early riser who sits down and prospers") to the southwest. The final section is the space in the center of the tray, the erilade opon ("the meeting place that crowns all"), for a total of nine sections. These sections come into play during consultations when the babalowo individually evokes the presence of Ifá and the nine ancient diviners before beginning the reading of the tray.
The circumference of opon Ifá may also be carved with animals that are significant in Yoruba mythology. Such markings are believed by practitioners to allow the babalowo to harness the powers of the depicted animal, enhancing the general efficacy of the tray, or heightening the effectiveness of certain odu. The abilities of the animals can sometimes be inferred by examining their roles in any of the 256 archetypal stories associated with the odu. For instance, Opon Ifá may display carvings of bush rats, or okete, which in Yoruba mythology can take on human form to conduct nighttime mischief. Birds are also depicted, which symbolize witchcraft. Finally, according to diviners from Oyo, Nigeria, snakes may symbolize the efficacy of Ifá divination as a whole, as it is believed that snakes obtained their venomous capacity from Ifá – as outlined in the odu okaran asa. Furthermore, snakes may symbolize Ifá himself, perhaps responsible for their prevalence in opon Ifá and in other Yoruba art. When abstract or crisscross markings are incorporated with zoomorphic imagery, they may offer a kinetic and sentient quality to the depicted animals, further enhancing the tray's divine potency.
Yoruba carvers
Historically, Yoruba carvers played an important role in their communities – many were specialists, creating an array of objects from the banal (e.g. stools, walking sticks, etc.) to the divine (e.g. shrine sculptures, headdresses, etc.). Most of the carvers specialized in opon Ifá traced their roots to Are Lagbayi, a master palace wood carver of old Oyo, in present-day Nigeria. His legacy is continued by the opon Ifá carvers who are frequented by babalowo, and create trays with designs of their own discretion or by request of their patron diviners. Some sources of aesthetic inspiration are the fables of storied diviners, the spirits and archetypal everyday experiences described by the odu, and instruments used during Ifá consultations – such as the iroke Ifá.
Variations
There are variations in the structure of opon Ifá, particularly in regard to the number and location of depicted Esu faces and the geometric shape of the board. Even within a town there will be different forms of the tray. For example, one tray may depict Esu with his chin protruding into the center of the tray (the erilade opon), while another depicts two Esu faces on opposite sides of the tray. Although the Ifá system of divination finds its roots among the Yoruba, its practise has spread amongst the African diaspora and is known by different names, with subtle to profound alterations.
Beyond the foundational features of the opon Ifá outlined above, the functional nature of the structural enhancements cannot be generalized and are typically left to the artist's discretion. A particularly notable specimen is one from the 17th century Kingdom of Dahomey, in present-day Benin, which was used for Fá divination. This board displays a standard circular opon Ifá in the center of the tray, but is encompassed by a larger, rectangular tray. In Cuban Santería, heavily influenced by Ifá, opon Ifá may also be employed; this will often display a broad color gamut, and may lack a depiction of Esu.
Yoruba beliefs
The face of Esu, the intermediary orisha between Ifá and the babalawo, is generally carved into the opon Ifá's perimeter to acknowledge his critical role during divine consultations and to allow the babalowo to directly confront him. The relationship between the two deities is outlined in the Yoruba canon – specifically from among the 256 odu, or verses, that the babalawo interprets from the opon Ifá – and provides an account for how Esu came to occupy his role. The following is an account of the myth by an Ifá chief from Oyo, Nigeria:
Ifá and Esu are two of the four-hundred orisha sent to Earth by Olodumare, the supreme being in Yoruba religion. Each of the four-hundred divinities has unique supernatural abilities; Ifá knows the predestined fate of all human beings, and Esu is the keeper of the ase (divine power or authority). Esu, confident in his status as the wisest among all of Olodumare's spirits, administered a test to 398 of the other deities, all of whom failed. Only then did Esu test Ifá.
Esu requested that Ifá supervise his monkey for one week while he undertook a journey. Ifá agreed, but first he asked Esu to tie the monkey to the tree in front of his house. After Esu had embarked on his journey, Ifá consulted an oracle to see what Esu's intentions were for his journey. The oracle prescribed to Ifá a sacrificial offering of bananas that must be performed deep in a thick forest. Ifá obliged and performed the sacrifice, only to find Esu's monkey missing once he returned to the tree in front of his home. Esu, having suddenly decided to not pursue his trip, returned to Ifá's home to see that Ifá had broken his commitment. Grief-stricken, Esu began to weep. He informed Ifá that if he did not find the monkey within the seven days that it takes for his tears to fall to the ground, Ifá would be cursed without peace for the rest of his life. Seeking a solution, Ifá once again consulted the oracle, who told him to return to the exact spot in the forest where the sacrifice of bananas had been performed. There, he would find the monkey. Ifá accepted the oracle's guidance and found Esu's monkey in the forest. Having returned the monkey to Esu before his tears hit the earth, Ifá completed the test and sealed his partnership with Esu. To express his gratitude, Esu swore to be a companion and accomplice to Ifá in all his endeavors. Thus, Esu acts as the mouthpiece through which Ifá imparts his clairvoyant knowledge.
In divination consultations
During a divination session, the babalawo first properly orients the tray with the "feet" of the opon Ifá facing towards him. He sits facing east, the direction from which Ifá is thought to have come from the spiritual plane, and allows light to illuminate the tray, being careful to prevent shadows from landing on the wood. Once properly oriented, an iroke Ifá, or a diviner's tapper, is used by the babalowo to evoke the presence of Ifá via the rhythmic drumming of the tapper on the surface of the opon Ifá. The nine diviners symbolically depicted in the tray's perimeter are also summoned. Then, sixteen palm or kola nuts, the ikin Ifá, are thrown onto the opon Ifá's wooden surface and the babalowo proceeds to interpret which of the 256 possible sets of odu (verses) are displayed by the nuts. An odu is essentially a word or sign of eight marks that is drawn in the iyerosun powder scattered over the tray. Each of the signs have corresponding verses which must be chanted and chosen according to the client's particular situation.
Each of the odu is constructed by individually determining each "letter" of the odu in a step-wise manner, starting from the bottom-right division of the border, then the bottom-left. Working up from bottom to top, this process is repeated six more times until the complete odu is constructed and written on the board. If sacred palm nuts are used, sixteen nuts are held in one hand by the babalawo. With the other hand, he snatches as many as he can out of his palm. If there is one remaining, he draws two vertical lines into the iyerosun powder on the board. If there are two nuts remaining, he draws only one line. The process continues until two figures of four segments each are formed.
Another way to use the opon Ifá incorporates a divination chain known as opele Ifá, reserving the palm or kola nuts for more serious questions. The opele consists of a chain of eight half-kola nuts strung together, each associated with one of the eight letters of an odu and a site along the tray's border. After evoking the spirits with the iroke Ifá, the babalowo then throws the opele; each of the eight half-nuts will land concave up or concave down, heads or tails. A single line represents "heads" while two vertical lines symbolize "tails" – this process is recorded in the iyerosun powder, as it is done with the palm nuts. Thus, this binary system of one and two vertical lines gives rise to 256 different odu, each associated with a spirit and certain archetypal situation. Some odu are affirmative, and others are negative. Furthermore, the odu determines what offerings the babalowo prescribes to the client in order for them to achieve their desired ends.
References
Religious objects
Yoruba culture
Yoruba words and phrases
Traditional African religions
Afro-American religion
Divination
Yoruba art | Opon Ifá | Physics | 2,997 |
6,137,903 | https://en.wikipedia.org/wiki/Saharan%20air%20layer | The Saharan air layer (SAL) is an extremely hot, dry, and sometimes dust-laden layer of the atmosphere that often overlies the cooler, more humid surface air of the Atlantic Ocean. It carries upwards of 60 million tons of dust annually over the ocean and the Americas. This annual phenomenon sometimes cools the ocean and suppresses Atlantic tropical cyclogenesis.
The SAL is a subject of ongoing study and research. Its existence was first postulated in 1972.
Creation
The dust cloud originates in Saharan Africa and extends from the surface upwards several kilometers. As the dust drives, or is driven out over the Atlantic ocean, it is lifted above the denser marine air. This atmospheric arrangement is an inversion where the temperature actually increases with height, as the boundary between the SAL and the marine layer suppresses or "caps" any convection originating in the marine layer. Since it is dry air, the lapse rate within the SAL itself is steep, that is, the temperature falls rapidly with height.
Disturbances such as large thunderstorm complexes over North Africa periodically result in vast dust and sand storms, some of which extend as high as . The layer is transported westwards cross the Atlantic by a series of broad anticyclonic eddies that are typically found above sea level. An estimated 60-200 million tons of dust particles are carried from the Sahara Desert region of North Africa, where it originates, and moves westward annually.
Sometimes a depression to the southwest of the Canary Islands increases the wind speed and intensity of the SAL, which can lift the dust around into the air and often carries the dust as far as the Caribbean.
Effects
The SAL passes over the Canary Islands where the phenomenon is named "calima" (English: "haze") and manifests as a fog that reduces visibility and deposits a layer of dust over everything. It is especially prevalent in the winter months. Canary islanders suffer respiratory problems during this weather event, and sometimes the dust is so bad that public life and transport halt completely. On January 8, 2002, the dust was so heavy over the Tenerife South Airport, dropping the visibility to , that it was forced to close.
From northern Africa, winds blow twenty percent of dust from a Saharan storm out over the Atlantic Ocean, and twenty percent of that, or four percent of a single storm's dust, reaches all the way to the western Atlantic. The remainder settles out into the ocean or washes out of the air with rainfall. Scientists believe the July 2000 measurements made in Puerto Rico, nearly 8 million tonnes, equaled about one-fifth of the year's total dust deposits.
The clouds of dust SAL creates are visible in satellite photos as a milky white to gray shade, similar to haze.
Findings to date indicate that the iron-rich dust particles that often occur within the SAL reflect solar radiation, thus cooling the atmosphere. The particles also reduce the amount of sunlight reaching the ocean, thus reducing the amount of heating of the ocean. They also tend to increase condensation as they drift into the marine layer below, but not precipitation as the drops formed are too small to fall and tend not to readily coalesce. These tiny drops are subsequently more easily evaporated as they move into drier air laterally or dry air mixes down from the SAL aloft. Research on aerosols also shows that the presence of small particles in air tends to suppress winds. The SAL has also been observed to suppress the development and intensifying of tropical cyclones, which may be related directly to these factors.
See also
African easterly jet
References
NOAA FAQ: Saharan Air Layer
Real Time SAL data
SAL over the Atlantic, current graphic display
Research: Aerosols Slow Wind
HA! Look at 2006! Where are the hurricanes? (SAL role in delaying hurricane season)
External links
NASA's 2013 HS3 Hurricane Mission to Delve into Saharan Dust
Meteorological phenomena
Atlantic Ocean
Sahara
Satellite interpretation
Tropical meteorology
Winds
Environment of Western Sahara | Saharan air layer | Physics | 798 |
20,135,897 | https://en.wikipedia.org/wiki/Use%20of%20costume%20in%20Athenian%20tragedy | Some authors have argued that costume use in Athenian tragedy was standardized for the genre. This is said to have consisted of a full-length or short tunic, a cloak and soft leather boots, and may have been derived from the robes of Dionysian priests or invented by Aeschylus. Brockett, however, disputes this, arguing that the evidence we have is based on archaeological remains, some few references in the texts, and the writings of later authors. As far as the vase paintings are concerned, most of these are dated later than the 5th century BCE and their relationship with theatrical practice is unclear. One of the earliest examples is a red-figure vase painting c. 500-490 BCE that shows a tragic chorus invoking a ghost, on a crater (bowl) in the Antikenmuseum in Basle.
The tragic actors were certainly heavily disguised. This had a religious purpose, for the actor was supposed to give up his identity in order to let another speak and act through him. Indeed, the dramas were performed in honour of Dionysus, the God of Ecstasy, which means “standing outside oneself”. Actors therefore had to renounce their individuality. The actors thought that the mask itself contained the character and are said to have prayed before putting on their masks. The costume was probably an elaborately-decorated version of everyday clothing worn in the 5th century BCE. The garments included:
chiton (robe or tunic)
chlaina (overgarment)
chlamys (short cloak)
kothurnus (short lace-up boots)
himation (overgarment)
peplos (cloak).
The chiton worn by the actors differed from that worn in everyday life because it incorporated sleeves, which were coloured and patterned. The sleeves may in fact have been part of an undergarment. Long white sleeves were worn by the (male) actors for female roles, and indeed, in vase paintings females are usually painted with lighter skin.
The costumes worn for the performances of Alcestis, for example, were iconographic, and symbolised the opposition of light and dark. In the play, life is evoked as the act of seeing the sun. Death – the son of Night in Greek mythology - wears a black peplos and black wings. Apollo wears white, representing the sun. Admetus contrasts the black of the funeral procession with the white of the funeral procession. The corpse of Alcestis is dressed as a bride, in accordance with Greek tradition and Herakles wears a bearskin and carries a club.
The costumes worn gave the audience an immediate sense of character-type, gender, age, social status and class.
Around the time of Aeschylus, the boots or buskins worn by the actors were flat. The actors had the same “status” as the chorus. In the 3rd century BCE, the actors were raised to the status of heroes and “platform” soles began to be used, together with a head-dress called an onkos. The raised soles may have induced a stylised way of walking, suited to the rhythm of tragic verse, and the onkos made the actors taller, enhancing visibility. Their bodies were padded so that they did not look too slim. However, some authors believe that this happened later than the 3rd century BCE. It is also thought that the “teetering gait” is a misapprehension.
The masks were the most striking feature of the costume worn by the Athenian actors. Facial expression was lost anyway due to the huge size of the Greek theatres, but the masks were also a means of blotting out expression, so visual meaning was expressed by the entire body. The actors were seen as silhouettes, or integral bodies, rather than faces. The masks themselves were made of stiffened linen, thin clay, cork or wood, and covered the whole head and had hair.
Attempts have been made in modern times to investigate the use of masks in Athenian tragedy through practice research. These explorations conclude that masks may lead to a more demonstrative style of acting, with declamatory delivery of the lines substituted for intimacy. They also found that the mask could impede the projection of sound. The Greeks are said to have overcome this in various ways. Initially, the mouth apertures were small, but later this became a “wide-open” mouth. Some authors believe that the mouth was shaped like a “mouth-trumpet” and had an amplifying effect. Certainly, the use of a mask covering the whole produces an enhanced resonating effect, which serves dramatic delivery.
Performances therefore had to be more physical. Peter Arnott states that the Greeks thought good acting and a good voice were synonymous. This was achieved through athletic training, voice exercises and diet.
Experiments have shown that unaccustomed actors suffer disorientation and restriction when masked. The Greeks countered this through a vocabulary of gesture known as (gesticulation). Aristotle says that in his day excessive gestures were used – leading to overacting – compared with the older tradition.
Masks can also be used as a dramatic tool, e.g. lowering the masks shows reflection, raising the mask shows a challenge or superiority. The Greeks called these physical stances schemata (forms).
Silent masks were used to great effect, particularly on child actors, expressing powerlessness, bewilderment, vulnerability, etc.
The use of masks enabled the three speaking actors to portray up to eight or nine characters, through multiple role-playing. The same character could therefore be played by different actors, and transitions within a character would be portrayed by the use of different masks.
The wide variety of masks used is attested by Pollux, a rhetorician writing in 2nd century CE, in his Onomastikon. He lists 30 different male masks (old age with white or grey hair, the tyrant with thick black hair, a fair, pale masks indicating sorrow or sickness, a boastful soldier, a rustic, servants, a cook, etc.) and 17 female masks (fat and thin old women, two matrons, one virgin, a bawd, a mistress, three courtesans, a lady's maid, etc.).
References
Sources
Taylor, David. The Greek and Roman Stage (Bristol Classical Press, 1999).
Simon, Erika . The Ancient Theatre (Taylor & Francis, 1982).
Webster, T.B.L. Greek Theatre Production (Methuen young books; 2nd ed., 1970)
Brockett, Oscar. History of the Theatre (Pearson, 2008)
Arnott, P. Introduction to the Greek Theatre (Papermac, 1971).
McDonald, Marianne & Walton, J. Michael. The Cambridge Companion to Greek and Roman Theatre (Cambridge University Press, 2007).
Rehm, Rush. Greek Tragic Theatre (Routledge, 1994).
McLeish, Kenneth & Griffiths, Trevor R. A Guide to Greek Theatre and Drama (Methuen, 2003).
Wiles, David. Tragedy in Athens(Cambridge University Press, 1999)
Laver, James. Costume in the Theatre(Harrap, 1964)
Costume
Athenian tragedy
Greek clothing
Ancient Greek plays
Ancient Greek tragedies | Use of costume in Athenian tragedy | Engineering | 1,464 |
37,580,917 | https://en.wikipedia.org/wiki/Moving%20load | In structural dynamics, a moving load changes the point at which the load is applied over time. Examples include a vehicle that travels across a bridge and a train moving along a track.
Properties
In computational models, load is usually applied as
a simple massless force,
an oscillator, or
an inertial force (mass and a massless force).
Numerous historical reviews of the moving load problem exist.
Several publications deal with similar problems.
The fundamental monograph is devoted to massless loads. Inertial load in numerical models is described in
Unexpected property of differential equations that govern the motion of the mass particle travelling on the string, Timoshenko beam, and Mindlin plate is described in. It is the discontinuity of the mass trajectory near the end of the span (well visible in string at the speed v=0.5c). The moving load significantly increases displacements. The critical velocity, at which the growth of displacements is the maximum, must be taken into account in engineering projects.
Structures that carry moving loads can have finite dimensions or can be infinite and supported periodically or placed on the elastic foundation.
Consider simply supported string of the length l, cross-sectional area A, mass density ρ, tensile force N, subjected to a constant force P
moving with constant velocity v. The motion equation of the string under the moving force has a form
Displacements of any point of the simply supported string is given by the sinus series
where
and the natural circular frequency of the string
In the case of inertial moving load, the analytical solutions are unknown. The equation of motion is increased by the term related to the inertia of the moving load. A concentrated mass m accompanied by a point force P:
The last term, because of complexity of computations, is often neglected by engineers. The load influence is reduced to the massless load term. Sometimes the oscillator is placed in the contact point. Such approaches are acceptable only in low range of the travelling load velocity. In higher ranges both the amplitude and the frequency of vibrations differ significantly in the case of both types of a load.
The differential equation can be solved in a semi-analytical way only for simple problems. The series determining the solution converges well and 2-3 terms are sufficient in practice. More complex problems can be solved by the finite element method or space-time finite element method.
The discontinuity of the mass trajectory is also well visible in the Timoshenko beam. High shear stiffness emphasizes the phenomenon.
The Renaudot approach vs. the Yakushev approach
Renaudot approach
Yakushev approach
Massless string under moving inertial load
Consider a massless string, which is a particular case of moving inertial load problem. The first to solve the problem was Smith.
The analysis will follow the solution of Fryba. Assuming
=0, the equation of motion of a string under a moving mass can
be put into the following form
We impose simply-supported boundary conditions and zero initial conditions. To solve this equation we use the convolution property. We assume dimensionless displacements of the string and
dimensionless time :
where st is the static deflection in the middle of
the string.
The solution is given by a sum
where is the dimensionless parameters :
Parameters , and are given below
In the case of =1, the considered problem has a closed solution:
References
Mechanical vibrations | Moving load | Physics,Engineering | 697 |
232,428 | https://en.wikipedia.org/wiki/Cruelty | Cruelty is the intentional infliction of suffering or the inaction towards another's suffering when a clear remedy is readily available. Sadism can also be related to this form of action or concept. Cruel ways of inflicting suffering may involve violence, but affirmative violence is not necessary for an act to be cruel.
Etymology
The term comes from Middle English, via the Old French term "crualte", which is based on Latin "crudelitas", from "crudelis".
The word has metaphorical uses, for example, "The cliffs remained cruel." (i.e., unclimbable when they desperately needed to be climbed) in The Lord of the Rings.
Usage in law
The term cruelty is often used in law and criminology with regard to the treatment of animals, children, spouses, and prisoners. When cruelty to animals is discussed, it often refers to unnecessary suffering. In criminal law, it refers to punishment, torture, victimization, draconian measures, and cruel and unusual punishment. In divorce cases, many jurisdictions permit a cause of action for cruel and inhumane treatment.
In law, cruelty is "the infliction of physical or mental distress, especially when considered a determinant in granting a divorce." According to Barozzo, there are four distinct conceptions of cruelty in criminal law. “The differences between these conceptions of cruelty rest on the types of agency, victimization, causality, and values that they employ.”
The first is the agent-objective conception, which is “exemplified by […] agency that goes above in degree and beyond in type the [suffering] allowed by applicable norms.” Under this conception, the victim suffered cruelty in light of “the objective character of the act or treatment” she was subjected to. Cruelty, in this sense, is defined as an “inclination of the mind toward the side of harshness”. Any punishment or other treatment that surpasses the scope of sufficiency and ventures into possibility is classified as excessive, and therefore, cruel.
The second conception is agent-subjective, in which “cruelty obtains only when the agent's deviant behavior is accompanied by the fault of character consisting in deriving personal delight from causing and witnessing suffering”. This conception is best understood under the presumption that punishment or other violence is a means to restore the offset in the cosmic order of the universe caused by wrongdoing. Anything that goes beyond what is necessary for this restoration, then, is cruel; the peace and harmony is not balanced with excessive punishment or violence—the scale of wrongdoing merely tips to the other side. For example, the Eighth Amendment of the U.S. Constitution prohibits cruel and unusual punishment, which means that we must “inquire into a prison official’s state of mind […]” when determining that the agent is not taking pleasure in inflicting pain and that punishment does not exceed the crime.
The third conception is victim-subjective, in which the “element of cruelty rests in the victim's intense experience of suffering”. Here, the pain or the sense of degradation and humiliation experienced particularly and uniquely by the victim is considered. Recognizing cruelty, then, requires reference to our compassion rather than some normative standard of reasonableness. Continuing with the example of punishment, the state’s intention is not relevant in determining whether a punishment is cruel. According to the law, “ill-treatment must attain a minimum level of severity”, and this minimum is determined by “all the circumstances of the case, such as the duration of the treatment, its physical or mental effects and, in some cases, the sex, age, and state of health of the victim, etc.”
The fourth and final conception is the accumulation of all the prior conceptions: the victim-objective and agent-independent. This conception “refers to severe violations of the respect, recognition, and care that the unconditional and inherent dignity of each and every individual command”. Under this view, “cruelty occurs when a grave violation of human dignity that in normal circumstances would amount to cruelty is caused by individuals or by the operation of impersonal institutions, structures or social processes, even if the victim is unaware of his predicament”.
Beyond serving as an analytical framework, these four conceptions—the distinctive features of each as well as their collective evolution—reflect the reality that “the phenomenon of cruelty […] is a human-made problem that calls for preventive and corrective responses”.
Criticism
One criticism of the concept of cruelty suggests that it conflates disregard for others with hurting others for its own sake, arguing that the two are mutually exclusive: total disregard for what another being feels (be it a human or non-human) would be incompatible with deriving pleasure from hurting that being for its own sake, since caring about inflicting suffering would be incompatible with not caring.
Literary references
George Eliot, in the short story "Janet's Repentance" from Scenes of Clerical Life, stated that "cruelty, like every other vice, requires no motive outside itself — it only requires opportunity." Philosopher Bertrand Russell argued that almost all marriage customs involve cruelty towards those who do not follow them, meaning there was no rational basis for condemning one custom or another as sinful; he concluded that "the cruelty habitually practised in punishing it is unnecessary...the infliction of cruelty with a good conscience is a delight to moralists. That is why they invented hell." Gilbert K. Chesterton stated that "cruelty is, perhaps, the worst kind of sin. Intellectual cruelty is certainly the worst kind of cruelty."
See also
Abuse
Cruelty-free
Schadenfreude
Spite
The Four Stages of Cruelty
Theatre of Cruelty
References
Paulo Barrozo,Cruelty in Criminal Law: Four Conceptions, 51 CRIM. L. BULLETIN 5 (2015).
Simon Baron-Cohen, The Science of Evil: On Empathy and the Origins of Cruelty, Basic Books, 2011. Reviewed in The Montreal Review
Susan Sontag, Regarding the Pain of Others, 2003.
Notes
External links
Abuse
Suffering
Aggression
Concepts in ethics | Cruelty | Biology | 1,258 |
1,775,884 | https://en.wikipedia.org/wiki/Betaine | A betaine () in chemistry is any neutral chemical compound with a positively charged cationic functional group that bears no hydrogen atom, such as a quaternary ammonium or phosphonium cation (generally: onium ions), and with a negatively charged functional group, such as a carboxylate group that may not be adjacent to the cationic site. Historically, the term was reserved for trimethylglycine (TMG), which is involved in methylation reactions and detoxification of homocysteine. This is a modified amino acid consisting of glycine with three methyl groups serving as methyl donor for various metabolic pathways.
Pronunciation
The pronunciation of the compound reflects its origin and first isolation from sugar beets (Beta vulgaris subsp. vulgaris), and does not derive from the Greek letter beta (β). It is commonly pronounced beta-INE or BEE-tayn.
Glycine betaine
The original betaine, N,N,N-trimethylglycine, was named after its discovery in sugar beet (Beta vulgaris subsp. vulgaris) in the nineteenth century. It is a small N-trimethylated amino acid. It is a zwitterion, which cannot isomerize because there is no labile hydrogen atom attached to the nitrogen atom. This substance may be called glycine betaine to distinguish it from other betaines.
Uses
Biochemistry
Phosphonium betaines are intermediates in the Wittig reaction. The addition of betaine to polymerase chain reactions improves the amplification of DNA by reducing the formation of secondary structure in GC-rich regions. The addition of betaine may enhance the specificity of the polymerase chain reaction by eliminating the base pair composition dependence of DNA melting.
Food additive
In 2017, the European Food Safety Authority concluded that betaine was safe "as a novel food to be used at a maximum intake level of 6 mg/kg body weight per day in addition to the intake from the background diet."
Approved drug
A prescription drug (Cystadane) containing betaine has limited use for oral treatment of genetic homocystinuria to lower levels of homocysteine in circulating blood.
Dietary supplement
Trimethylglycine, a betaine, is used as a dietary supplement, although there is no evidence that it is effective or safe. Common side effects of taking oral betaine include nausea and stomach upset.
Safety
Many betaines are irritants of the eyes and skin.
See also
Cocamidopropyl betaine
Mesoionic
Mesomeric betaine
Osmoprotectants
Ylide
References
Further reading
Quaternary ammonium compounds
Zwitterions
Surfactants | Betaine | Physics,Chemistry | 559 |
23,899,486 | https://en.wikipedia.org/wiki/KeepVault | KeepVault is an online backup service to perform online and local backups of Windows-based personal computers and servers. KeepVault uses a storage-based pricing model which allows it to offer unlimited users and devices under one account. The KeepVault technology uses end-to-end encryption and files can be accessed from other computers or via the web.
History
KeepVault was first created by Proxure in 2006. In January 2012 Proxure was acquired by AuthenTec, Inc. Following AuthenTec, Inc.’s acquisition by Apple, Inc., KeepVault was acquired by a group of the original developers and became an independent company.
Products
Keepvault offers a Windows desktop application and a Windows Server Add-in, and has two plan types (Home and Professional) as well as free local backup.
OEM Distribution
In 2007 KeepVault was an early OEM vendor for backup when Microsoft launched Windows Home Server. KeepVault was shipped on the HP Data Vault and HP Mediasmart servers.
Starting in 2013, the KeepVault Dashboard Add-in is preinstalled on the Western Digital Sentinel server series.
Backup Awareness Week
As a joint business and community effort KeepVault launched Backup Awareness Week in May of 2014. “Backup Week” is designed to educate the public about the risks of data loss, and ways to protect their data.
Criticism
In 2008 bloggers complained about the end of unlimited data plans. Since then KeepVault has taken the position that unlimited plans are unsustainable.
See also
List of online backup services
References
External links
Backup software
Backup
File hosting
Cloud storage
Windows software
File hosting for Windows | KeepVault | Engineering | 339 |
7,973,767 | https://en.wikipedia.org/wiki/Vandetanib | Vandetanib, sold under the brand name Caprelsa, is an anti-cancer medication that is used for the treatment of certain tumours of the thyroid gland. It acts as a kinase inhibitor of a number of cell receptors, mainly the vascular endothelial growth factor receptor, the epidermal growth factor receptor, and the RET-tyrosine kinase. The drug was developed by AstraZeneca who later sold the rights to Sanofi in 2015.
Medical use
Vandetanib is used to treat medullary thyroid cancer in adults who are ineligible for surgery.
Contraindications
The V804M mutation in RET confers resistance to Vandetanib anti-RET activity.
In people with moderate and severe hepatic impairment, no dosage for vandetanib has been recommended, as its safety and efficacy has not been established yet. Vandetanib is contraindicated in people with congenital long QT syndrome.
Adverse effects
Very common (present in greater than 10% of people) adverse effects include colds, bronchitis, upper respiratory tract infections, urinary tract infections, decreased appetite, low calcium absorption, insomnia, depressed mood, Headache, tingling sensations, weird, painful sensations, dizziness, blurred vision, damage to the cornea, long QT syndrome, high blood pressure, stomach pain, diarrhea, nausea, vomiting, indigestion, sensitivity to sunlight, rash, acne, dry and itchy skin, nail disorders, protein in urine, kidney stones, weakness, fatigue, pain, and edema.
Common (present in between 1% and 10% of people) adverse effects include pneumonia, sepsis, influenza, cystitis, sinusitis, laryngitis, folliculitis, boils, fungal infection, kidney infections, low thyroid hormone levels, low potassium, high calcium levels, hyperglycemia, hypercholesterolemia, hypertriglyceridemia, dehydration, low sodium levels, anxiety, tremor, lethargy, loss of consciousness, balance disorders, changes in sense of taste, visual impairment, halo vision, perceived light flashes, glaucoma, pink eye, dry eye, keratopathy, hypertensive crisis, mini strokes, nose bleeds, coughing up blood, defecating blood, colitis, dry mouth, stomatitis, constipation, gastritis, gallstones, Chemotherapy-induced acral erythema, hair loss, painful urination, bloody urine, kidney failure, frequent urination, urgent need to urinate, and fever.
Interactions
Vandetanib has been reported as a substrate for the OATP1B1 and OATP1B3 transporters. Interaction of vandetanib with OATP1B1 and OATP1B3 may alter its hepatic disposition and can lead to transporter mediated drug-drug interactions. Also, vandetanib is an inhibitor of OATP1B3 transporter but not for OATP1B1.
Other drugs that prolong the QT interval can possibly add to this side effect of vandetanib. As the drug is partly metabolised via the liver enzyme CYP3A4, strong inducers of this enzyme can decrease its blood plasma concentrations. CYP3A4 inhibitors do not significantly increase vandetanib concentrations, presumably because it is also metabolised by flavin containing monooxygenase 1 (FMO1) and 3.
Pharmacology
Vandetanib is an inhibitor of vascular endothelial growth factor receptor-2, epidermal growth factor receptor, and RET tyrosine kinases. RET tyrosine kinases; it weakly inhibits vascular endothelial growth factor receptor-3.
Vandetanib is well absorbed from the gut, reaches peak blood plasma concentrations 4 to 10 hours after application, and has a half-life of 19 days on average, per pharmacokinetic studies. It has to be taken for about three months to achieve a steady-state concentration. In the blood, it is almost completely (90–96%) bound to plasma proteins such as albumin. It is metabolised to N-desmethylvandetanib via CYP3A4 and to vandetanib-N-oxide via FMO1 and 3. Both of these are active metabolites. Vandetanib is excreted via the faeces (44%) and the urine (25%) in form of the unchanged drug and the metabolites.
History
Vandetanib was approved by the FDA in April 2011, for treatment of late-stage thyroid cancer.
Vandetanib was first initially marketed without a trade name; it has been marketed under the trade name Caprelsa since August 2011.
In 2015 Genzyme acquired the product from AstraZeneca.
Research
AstraZeneca tested Vandetanib in clinical trials for non-small cell lung cancer and submitted an application for approval to the EMA but then withdrew the application in October 2009 after trials showed no benefit when the drug was administered alongside chemotherapy. A clinical trial of vandetanib plus gemcitabine versus placebo plus gemcitabine in locally advanced or metastatic pancreatic carcinoma was negative in a prospective, randomised, double-blind, multicentre phase 2 trial.
References
Angiogenesis inhibitors
Receptor tyrosine kinase inhibitors
Quinazolines
Amines
Bromoarenes
Fluoroarenes
Phenol ethers
Piperidines
Drugs developed by AstraZeneca
Sanofi | Vandetanib | Chemistry,Biology | 1,176 |
78,396,381 | https://en.wikipedia.org/wiki/Gennaro%20Maria%20D%27Afflitto | Gennaro Maria D'Afflitto (1618 – 1673) was an Italian Dominican friar and military engineer who worked under Philip IV and Charles II of Spain.
Biography
Gennaro Maria D'Afflitto was born into a noble family in Naples in 1618. On 16 September 1633, he entered the Dominican convent of Santa Maria della Sanità, Naples. He received a good scientific and humanistic education, and developed a keen interest in mathematics. In 1647 he met Don John Joseph of Austria, who had been sent to Naples to quell the rebellion of Masaniello. He followed him in the campaign to recapture Orbetello and Porto Longone (1650) and later served as military engineer in the Spanish Army in Catalonia, Portugal and the Southern Netherlands. In 1663 the Supreme Council of War appointed him as professor of mathematics in the Real Academia de Matemáticas, Artillería y Fortificación of Madrid. He was in charge of the chair until 1665. In the following years, he came under the service of Ferdinando II of Tuscany again as a teacher of mathematics and military engineer. At the end of 1667 he became an advisor to the Republic of Genoa on engineering matters, and worked on the fortifications of Savona and Vado Ligure. D'Afflitto is also credited with fortification works in Cuneo and Nizza Marittima on behalf of the House of Savoy. He died at Naples in 1673.
Works
D'Afflitto published at Madrid a treatise on fortifications in two volumes, De Munitione et Fortificatione, Libri duo. The first volume is dedicated to Don John Joseph of Austria. Abstracts of this work were published at Florence in 1665, by Captain Giovanni Battista Sergiuliani, and in 1667 by Filippo Domenico Mazzenghi. Likewise, he is the author of Compendio de modernas fortificaciones (Compendium of Modern Fortifications), translated into Spanish in 1657 by Baltasar Siscara. D'Afflitto wrote also a treatise on fire and explosive weapons, De igne et ignivomis (Zaragoza, 1661). The work is divided into two parts: the first deals with the nature of fire and the different kinds of fuels; the second describes various types of explosives. He left in manuscript Terra seu quadripartites orbis, Compendio della Sfera universale, and a number of poems and miscellaneous tracts on philosophical and theological topics. Jonas Moore considered D'Afflitto, together with Francesco Tensini and Pietro Sardi, one of Italy's foremost experts on fortification.
Published works
De munitione et fortificatione (Matriti s. d.)
References
Bibliography
Italian engineer stubs
Italian engineers
Military engineering
Engineers from Naples
1618 births
1673 deaths | Gennaro Maria D'Afflitto | Engineering | 578 |
546,039 | https://en.wikipedia.org/wiki/Syntax%20%28logic%29 | In logic, syntax is anything having to do with formal languages or formal systems without regard to any interpretation or meaning given to them. Syntax is concerned with the rules used for constructing, or transforming the symbols and words of a language, as contrasted with the semantics of a language which is concerned with its meaning.
The symbols, formulas, systems, theorems and proofs expressed in formal languages are syntactic entities whose properties may be studied without regard to any meaning they may be given, and, in fact, need not be given any.
Syntax is usually associated with the rules (or grammar) governing the composition of texts in a formal language that constitute the well-formed formulas of a formal system.
In computer science, the term syntax refers to the rules governing the composition of well-formed expressions in a programming language. As in mathematical logic, it is independent of semantics and interpretation.
Syntactic entities
Symbols
A symbol is an idea, abstraction or concept, tokens of which may be marks or a metalanguage of marks which form a particular pattern. Symbols of a formal language need not be symbols of anything. For instance there are logical constants which do not refer to any idea, but rather serve as a form of punctuation in the language (e.g. parentheses). A symbol or string of symbols may comprise a well-formed formula if the formulation is consistent with the formation rules of the language. Symbols of a formal language must be capable of being specified without any reference to any interpretation of them.
Formal language
A formal language is a syntactic entity which consists of a set of finite strings of symbols which are its words (usually called its well-formed formulas). Which strings of symbols are words is determined by the creator of the language, usually by specifying a set of formation rules. Such a language can be defined without reference to any meanings of any of its expressions; it can exist before any interpretation is assigned to it – that is, before it has any meaning.
Formation rules
Formation rules are a precise description of which strings of symbols are the well-formed formulas of a formal language. It is synonymous with the set of strings over the alphabet of the formal language which constitute well formed formulas. However, it does not describe their semantics (i.e. what they mean).
Propositions
A proposition is a sentence expressing something true or false. A proposition is identified ontologically as an idea, concept or abstraction whose token instances are patterns of symbols, marks, sounds, or strings of words. Propositions are considered to be syntactic entities and also truthbearers.
Formal theories
A formal theory is a set of sentences in a formal language.
Formal systems
A formal system (also called a logical calculus, or a logical system) consists of a formal language together with a deductive apparatus (also called a deductive system). The deductive apparatus may consist of a set of transformation rules (also called inference rules) or a set of axioms, or have both. A formal system is used to derive one expression from one or more other expressions. Formal systems, like other syntactic entities may be defined without any interpretation given to it (as being, for instance, a system of arithmetic).
Syntactic consequence within a formal system
A formula A is a syntactic consequence within some formal system of a set Г of formulas if there is a derivation in formal system of A from the set Г.
Syntactic consequence does not depend on any interpretation of the formal system.
Syntactic completeness of a formal system
A formal system is syntactically complete (also deductively complete, maximally complete, negation complete or simply complete) iff for each formula A of the language of the system either A or ¬A is a theorem of . In another sense, a formal system is syntactically complete iff no unprovable axiom can be added to it as an axiom without introducing an inconsistency. Truth-functional propositional logic and first-order predicate logic are semantically complete, but not syntactically complete (for example the propositional logic statement consisting of a single variable "a" is not a theorem, and neither is its negation, but these are not tautologies). Gödel's incompleteness theorem shows that no recursive system that is sufficiently powerful, such as the Peano axioms, can be both consistent and complete.
Interpretations
An interpretation of a formal system is the assignment of meanings to the symbols, and truth values to the sentences of a formal system. The study of interpretations is called formal semantics. Giving an interpretation is synonymous with constructing a model. An interpretation is expressed in a metalanguage, which may itself be a formal language, and as such itself is a syntactic entity.
See also
Symbol (formal)
Formation rule
Formal grammar
Syntax (linguistics)
Syntax (programming languages)
Mathematical logic
Well-formed formula
References
External links
Formal languages
Metalogic
Concepts in logic
Philosophy of logic | Syntax (logic) | Mathematics | 1,021 |
42,735,438 | https://en.wikipedia.org/wiki/The%20Astounding%2C%20the%20Amazing%2C%20and%20the%20Unknown | The Astounding, the Amazing, and the Unknown is an alternate historical adventure novel written by Paul Malmont, the sequel to The Chinatown Death Cloud Peril (2007). It features real-life pulp magazine authors of the past as the heroes of adventures reminiscent of their favored genres. The book was first published in hardcover by Simon & Schuster and audiobook by Brilliance Audio in July 2011. The title is drawn from those of the magazines, Astounding Science-Fiction, Amazing Stories, and Unknown, for which his main protagonists wrote.
Plot
The story, divided into short, numbered "episodes" rather than chapters, is presented as a "story about Nikola Tesla" recounted by Richard Feynman to a group of other Manhattan Project scientists in the wake of World War II. It involves the efforts of a similar think-tank, the Kamikaze Group, to uncover the secret of a rumored "super-weapon" Tesla had developed before his death, one supposedly responsible for the mysterious Tunguska explosion of 1908. Feynman makes no claims for the tale's veracity, a caution warranted at the end of the book when his informant is revealed to have been pulp writer L. Ron Hubbard, a participant in the novel's events portrayed as a self-promoting, delusional narcissist.
Malmont bases the Kamikaze Group on the trio of science fiction writers, Robert A. Heinlein, L. Sprague de Camp and Isaac Asimov, who in actual history spent most of the war doing aeronautical engineering research for the U.S. Navy at the Philadelphia Naval Shipyard's Naval Air Experimental Station. He portrays them as engaged in a joint project there to develop super-scientific weapons to help the U.S. win the war, though in reality they worked separately on technical improvements to airplanes and weapons systems. Heinlein leads the fictional project, which also draws on the assistance of other pulp authors of his acquaintance, most notably Hubbard, Walter B. Gibson, and Lester Dent, with cameo roles by John W. Campbell, Norvell Page, Hugh B. Cave, Frederik Pohl, Cleve Cartmill, Kurt Vonnegut, Judith Merril, and Ray Bradbury. Additional historical luminaries such as Jack Parsons, Albert Einstein and Jimmy Stewart also put in appearances.
After Tesla's mysterious death the military raids his apartment and confiscates his papers, spurred by apparent German interest in his discoveries. Heinlein is charged with investigating the supposed "wonder weapon" referred to in the papers. Together with de Camp, Asimov, Hubbard and Gibson he explores a sub-basement of the Empire State Building where Tesla had left some of his equipment, and is almost trapped there by an unknown adversary. Further inquiries take the core group to the former site of Wardenclyffe Tower, the inventor's wireless transmission facility in Shoreham, New York, which apparently doubled as the "sending" component of the weapon. Afterwards Hubbard is sent first to the Aleutian Islands and then the South Pacific to retrieve the receiver, while Asimov is put in charge of securing the capacitors needed to make the transmitter work.
Meanwhile, government goons are investigating the group itself, alarmed by the publication of Cartmill's story "Deadline," with its all-too accurate description of a nuclear weapon similar to that being developed by the Manhattan Project. Their brutal interrogation of Heinlein is interrupted by a deadly phone call via which they are somehow electrocuted in the same fashion as Tesla. Matters come to a head as the Kamikaze Group seemingly makes good a promise to "make a ship disappear" (a nod to the "Philadelphia Experiment" urban legend), while Heinlein, convinced that time is running out, works with Tesla's ex-assistant at a duplicate of Wardencyffe Tower to make the wonder weapon functional. Once it is activated the assistant reveals himself as the group's prime adversary, and nearly succeeds in killing the group members before falling to his death in the pits beneath the tower.
After the villain's defeat the military shuts down the Kamikaze Group. Heinlein is disheartened to discover that his group was conceived and regarded as a mere blind to distract the Axis powers from the U.S.'s real super weapon effort—the Manhattan Project. His assertions of the reality of Tesla's weapon fall on deaf ears.
Much later, Hubbard, returning to the U.S. after the war, learns what has become of his former compatriots, encounters Feynman, and tells him the story.
Reception
Michael Dirda, writing for The Washington Post, feels the novel "never quite lives up to its title. It opens slowly, breaks up its narrative among too many different characters and plot lines, and is unpersuasively framed as a story related by physicist Richard Feynman. Frequent comic episodes, some verging on slapstick, don't wholly come off. Nor are the big scenes - involving secret tunnels underneath the Empire State Building or the final showdown at Tesla's Tower - altogether fresh. I couldn't follow much of the science, and Hubbard's feverish dreams reminded me of accounts of bad LSD trips." He concludes, however, that "if you're already a fan of any of the writer-heroes of this novel, you'll probably be irresistibly drawn to The Astounding, the Amazing, and the Unknown. And the book does have some good moments. It's almost worth reading just to arrive at the pronouncement: 'Oh my God! . . . You've vaporized Isaac Asimov!'"
Rege Behe in the Pittsburgh Tribune calls the book "humorous and clever, . . . an opus waiting for Hollywood to call." In reference to the book's title he notes that it "is all of those things, a joyous romp grounded in the golden age of science and pulp fiction in the 1940s. The author's cast . . . are wonderfully realized."
Paul Di Filippo in The Speculator "applaud[s] its vigorous storytelling and historical acumen," calling the book's style "by turns analytical, journalistic, affectionate, elegiac, philosophical, and, well, pulpish. [Malmont] reconstructs his characters and their era with historical fidelity and empathy without feeling chained to total textbook accuracy . . . [blending] verisimilitude with outlandish blood-and-thunder action" in a "seething scrum of high-minded conversation and low-down deeds . . . Malmont plainly has a blast recreating this dangerous, promising era and putting its inhabitants through their larger-than-life paces." Di Filippo does twit the author for his anachronistic use of the term "sci-fi," not coined until the late 1950s, but feels that "[t]aken all in all, the book delivers both thrills and meditative reflections on the writerly condition."
The book was also reviewed by Amy Goldschlager in Locus, no. 612, January 2012.
Notes
2011 American novels
American alternate history novels
Simon & Schuster books
Cultural depictions of Nikola Tesla
Tunguska event
Novels about writers
Cultural depictions of Albert Einstein | The Astounding, the Amazing, and the Unknown | Physics | 1,512 |
71,625,153 | https://en.wikipedia.org/wiki/Oath%3A%20Chronicles%20of%20Empire%20and%20Exile | Oath: Chronicles of Empire and Exile is a 2021 board game with asymmetric gameplay and legacy elements designed by Cole Wehrle, illustrated by Kyle Ferrin, and published by Leder Games. In Oath, players compete to become the Chancellor, and the events of each game influence the events of the games that follow. Upon its release, Oath received positive reviews, and an expansion for the game is in development. The game is part of an increase in the release of games that are based on a scenario or have a campaign structure, and is focused on fantasy politics and crisis.
Gameplay
In Oath, 1-6 players compete in an asymmetric game, taking upon the role of individuals who are trying to rule a fantasy land. One Chancellor player begins with significant control over eight Sites which are divided between three regions: the Cradle, the Provinces and the Hinterland. The other players start with an Exile character that can eventually become a Citizen. Everyone has the same major actions; they may search the deck, muster troops, trade favor and secrets (the two main currencies in the game), recover relics, campaign militarily against enemies, and travel across the board. Through the use of Denizen cards that can be picked up throughout the game, players are given access to unique powers. For games with only one or two players, the game includes an automated version of the Chancellor, the Clockwork Prince.
Victory can be earned in several ways. The Chancellor, if they continue to fulfil their Oathkeeper goal throughout the game, may roll a dice three times from turn five until turn eight, increasing their chances to win each turn. Vision cards can be picked up by Exiles which also enable victory goals, and an Exile may also attempt to usurp the Chancellor by completing the game's main goal. If the Chancellor wins but a Citizen has fulfilled certain conditions, the Citizen may win instead. Often, the game will end with a losing player forced to be a kingmaker for the other players, often decided through informal deal making and metagaming.
Development
The game was in development since 2018. Wehrle sought in the production of Oath to place narrative value as a priority, and to remove any predetermined scenarios so that every element of the game could be altered. His experience of second hand board games during childhood, such as Squad Leader and other Avalon Hill board games as well as HeroQuest and Chancellorsville, led him to want to design a board game that had a "more resonant echo"; he wanted each box to have a tangible history without the player destroying parts of it, as was the norm in many legacy games. Other inspirations for Wehrle in terms of Oath included Imperium, Barbarian, Kingdom and Empire, and Blood Royale, a role-playing game.
In 2022, Wehrle announced that Leder Games was designing an expansion for Oath.
Kickstarter
A Kickstarter campaign for the game was launched in January 2020 to fund its production, with a single pledge level of $90. Backers who pledged this amount received a journal to chronicle their sessions as well as metal favor coins and resin secret tokens, which were sold separately to the public upon the game's full release. It met its funding goal of $50,000 quickly.
Reception
Oath received generally positive reviews. Dicebreaker wrote of its "small, thoughtful details" and "evocative world and deep strategy". Tabletop Gaming compared Ferrin's artwork for the game to The Dark Crystal, calling it "evocative and characterful." Polygon described the game as "an elaborate role-playing game wearing the clothes of a complex strategy title", and later praised the game for its neoprene game board. In 2021, Gamereactor complimented its production and design, but also wrote of the game's steep learning curve and niche target audience. IGN listed the game as one of the best strategy board games in 2022.
Awards
2021 Golden Geek Award for 'Most Innovative Board Game'
2021 Tabletop Gaming Award for 'Best Board Game of 2021'
2021 Dice Tower 'Best Game from a Small Publisher' nominee
2022 SXSW Gaming Awards' 'Tabletop Game of the Year' nominee
2022 American Tabletop Awards' 'Complex Games' award nominee.
See also
Root, Pax Pamir, and John Company, other board games designed by Cole Wehrle
References
External links
Oath page on the Leder Games website
American board games
Asymmetric board games
Board games introduced in 2021
Fantasy board games
Kickstarter-funded tabletop games
Legacy games | Oath: Chronicles of Empire and Exile | Physics | 941 |
26,618,143 | https://en.wikipedia.org/wiki/HD%20180902%20b | HD 180902 b is an extrasolar planet orbiting the K-type star HD 180902 approximately 342 light years away in the constellation Sagittarius.
Discovery
HD 180902 b, along with other planets, was discovered in 2010 by scientists at the Keck Observatory. These planets were discovered via doppler spectroscopy, which is detecting exoplanets using the star's wobble.
Properties
Orbit
HD 180902 b takes 510 days to orbit its parent star, which is longer than Earth's orbital period, which is 365 days. It orbits at a distance similar to Earth from the sun. HD 180902 orbits with mild eccentricity.
Characteristics
HD 180902 b has a minimum mass of 1.685 times the mass of Jupiter, but since its inclination is not known, the true mass of the planet cannot be detected. According to a theoretical search by the observatory, it may have a radius that is 22.1% larger than Jupiter.
See also
HD 4313 b
HD 181342 b
HD 206610 b
HD 136418 b
HD 212771 b
References
External links
Exoplanets discovered in 2010
Exoplanets detected by radial velocity
Sagittarius (constellation)
Giant planets | HD 180902 b | Astronomy | 254 |
26,501,091 | https://en.wikipedia.org/wiki/Arden%27s%20rule | In theoretical computer science, Arden's rule, also known as Arden's lemma, is a mathematical statement about a certain form of language equations.
Background
A (formal) language is simply a set of strings. Such sets can be specified by means of some language equation, which in turn is based on operations on languages. Language equations are mathematical statements that resemble numerical equations, but the variables assume values of formal languages rather than numbers. Among the most common operations on two languages A and B are the set union A ∪ B, and their concatenation A⋅B. Finally, as an operation taking a single operand, the set A* denotes the Kleene star of the language A.
Statement of Arden's rule
Arden's rule states that the set A*⋅B is the smallest language that is a solution for X in the linear equation X = A⋅X ∪ B where X, A, B are sets of strings. Moreover, if the set A does not contain the empty word, then this solution is unique.
Equivalently, the set B⋅A* is the smallest language that is a solution for X in X = X⋅A ∪ B.
Application
Arden's rule can be used to help convert some finite automatons to regular expressions, as in Kleene's algorithm.
See also
Regular expression
Nondeterministic finite automaton
Notes
References
Arden, D. N. (1960). Delayed logic and finite state machines, Theory of Computing Machine Design, pp. 1-35, University of Michigan Press, Ann Arbor, Michigan, USA.
(open-access abstract)
John E. Hopcroft and Jeffrey D. Ullman, Introduction to Automata Theory, Languages, and Computation, Addison-Wesley Publishing, Reading Massachusetts, 1979. . Chapter 2: Finite Automata and Regular Expressions, p.54.
Arden, D.N. An Introduction to the Theory of Finite State Machines, Monograph No. 12, Discrete System Concepts Project, 28 June 1965.
Formal languages | Arden's rule | Mathematics | 412 |
1,500,520 | https://en.wikipedia.org/wiki/Cross%20sea | A cross sea (also referred to as a squared sea or square waves) is a sea state of wind-generated ocean waves that form nonparallel wave systems. Cross seas have a large amount of directional spreading. This may occur when water waves from one weather system continue despite a shift in wind. Waves generated by the new wind run at an angle to the old.
Two weather systems that are far from each other may create a cross sea when the waves from the systems meet at a place far from either weather system. Until the older waves have dissipated, they can present a perilous sea hazard.
This sea state is fairly common and a large percentage of ship accidents have been found to occur in this state. Vessels fare better against large waves when sailing directly perpendicular to oncoming surf. In a cross sea scenario, that becomes impossible as sailing into one set of waves necessitates sailing parallel to the other.
A cross swell is generated when the wave systems are longer-period swells, rather than short-period wind-generated waves.
Notes
References
Water waves | Cross sea | Physics,Chemistry | 217 |
1,606,195 | https://en.wikipedia.org/wiki/Smith%E2%80%93Waterman%20algorithm | The Smith–Waterman algorithm performs local sequence alignment; that is, for determining similar regions between two strings of nucleic acid sequences or protein sequences. Instead of looking at the entire sequence, the Smith–Waterman algorithm compares segments of all possible lengths and optimizes the similarity measure.
The algorithm was first proposed by Temple F. Smith and Michael S. Waterman in 1981. Like the Needleman–Wunsch algorithm, of which it is a variation, Smith–Waterman is a dynamic programming algorithm. As such, it has the desirable property that it is guaranteed to find the optimal local alignment with respect to the scoring system being used (which includes the substitution matrix and the gap-scoring scheme). The main difference to the Needleman–Wunsch algorithm is that negative scoring matrix cells are set to zero. Traceback procedure starts at the highest scoring matrix cell and proceeds until a cell with score zero is encountered, yielding the highest scoring local alignment. Because of its cubic time complexity, it often cannot be practically applied to large-scale problems and is replaced in favor of computationally more efficient alternatives such as (Gotoh, 1982), (Altschul and Erickson, 1986), and (Myers and Miller, 1988).
History
In 1970, Saul B. Needleman and Christian D. Wunsch proposed a heuristic homology algorithm for sequence alignment, also referred to as the Needleman–Wunsch algorithm. It is a global alignment algorithm that requires calculation steps ( and are the lengths of the two sequences being aligned). It uses the iterative calculation of a matrix for the purpose of showing global alignment. In the following decade, Sankoff, Reichert, Beyer and others formulated alternative heuristic algorithms for analyzing gene sequences. Sellers introduced a system for measuring sequence distances. In 1976, Waterman et al. added the concept of gaps into the original measurement system. In 1981, Smith and Waterman published their Smith–Waterman algorithm for calculating local alignment.
The Smith–Waterman algorithm is fairly demanding of time: To align two sequences of lengths and , time is required. Gotoh and Altschul optimized the algorithm to steps. The space complexity was optimized by Myers and Miller from to (linear), where is the length of the shorter sequence, for the case where only one of the many possible optimal alignments is desired. Chowdhury, Le, and Ramachandran later optimized the cache performance of the algorithm while keeping the space usage linear in the total length of the input sequences.
Motivation
In recent years, genome projects conducted on a variety of organisms generated massive amounts of sequence data for genes and proteins, which requires computational analysis. Sequence alignment shows the relations between genes or between proteins, leading to a better understanding of their homology and functionality. Sequence alignment can also reveal conserved domains and motifs.
One motivation for local alignment is the difficulty of obtaining correct alignments in regions of low similarity between distantly related biological sequences, because mutations have added too much 'noise' over evolutionary time to allow for a meaningful comparison of those regions. Local alignment avoids such regions altogether and focuses on those with a positive score, i.e. those with an evolutionarily conserved signal of similarity. A prerequisite for local alignment is a negative expectation score. The expectation score is defined as the average score that the scoring system (substitution matrix and gap penalties) would yield for a random sequence.
Another motivation for using local alignments is that there is a reliable statistical model (developed by Karlin and Altschul) for optimal local alignments. The alignment of unrelated sequences tends to produce optimal local alignment scores which follow an extreme value distribution. This property allows programs to produce an expectation value for the optimal local alignment of two sequences, which is a measure of how often two unrelated sequences would produce an optimal local alignment whose score is greater than or equal to the observed score. Very low expectation values indicate that the two sequences in question might be homologous, meaning they might share a common ancestor.
Algorithm
Let and be the sequences to be aligned, where and are the lengths of and respectively.
Determine the substitution matrix and the gap penalty scheme.
- Similarity score of the elements that constituted the two sequences
- The penalty of a gap that has length
Construct a scoring matrix and initialize its first row and first column. The size of the scoring matrix is . The matrix uses 0-based indexing.
Fill the scoring matrix using the equation below.
where
is the score of aligning and ,
is the score if is at the end of a gap of length ,
is the score if is at the end of a gap of length ,
means there is no similarity up to and .
Traceback. Starting at the highest score in the scoring matrix and ending at a matrix cell that has a score of 0, traceback based on the source of each score recursively to generate the best local alignment.
Explanation
Smith–Waterman algorithm aligns two sequences by matches/mismatches (also known as substitutions), insertions, and deletions. Both insertions and deletions are the operations that introduce gaps, which are represented by dashes. The Smith–Waterman algorithm has several steps:
Determine the substitution matrix and the gap penalty scheme. A substitution matrix assigns each pair of bases or amino acids a score for match or mismatch. Usually matches get positive scores, whereas mismatches get relatively lower scores. A gap penalty function determines the score cost for opening or extending gaps. It is suggested that users choose the appropriate scoring system based on the goals. In addition, it is also a good practice to try different combinations of substitution matrices and gap penalties.
Initialize the scoring matrix. The dimensions of the scoring matrix are 1+length of each sequence respectively. All the elements of the first row and the first column are set to 0. The extra first row and first column make it possible to align one sequence to another at any position, and setting them to 0 makes the terminal gap free from penalty.
Scoring. Score each element from left to right, top to bottom in the matrix, considering the outcomes of substitutions (diagonal scores) or adding gaps (horizontal and vertical scores). If none of the scores are positive, this element gets a 0. Otherwise the highest score is used and the source of that score is recorded.
Traceback. Starting at the element with the highest score, traceback based on the source of each score recursively, until 0 is encountered. The segments that have the highest similarity score based on the given scoring system is generated in this process. To obtain the second best local alignment, apply the traceback process starting at the second highest score outside the trace of the best alignment.
Comparison with the Needleman–Wunsch algorithm
The Smith–Waterman algorithm finds the segments in two sequences that have similarities while the Needleman–Wunsch algorithm aligns two complete sequences. Therefore, they serve different purposes. Both algorithms use the concepts of a substitution matrix, a gap penalty function, a scoring matrix, and a traceback process. Three main differences are:
One of the most important distinctions is that no negative score is assigned in the scoring system of the Smith–Waterman algorithm, which enables local alignment. When any element has a score lower than zero, it means that the sequences up to this position have no similarities; this element will then be set to zero to eliminate influence from previous alignment. In this way, calculation can continue to find alignment in any position afterwards.
The initial scoring matrix of Smith–Waterman algorithm enables the alignment of any segment of one sequence to an arbitrary position in the other sequence. In Needleman–Wunsch algorithm, however, end gap penalty also needs to be considered in order to align the full sequences.
Substitution matrix
Each base substitution or amino acid substitution is assigned a score. In general, matches are assigned positive scores, and mismatches are assigned relatively lower scores. Take DNA sequence as an example. If matches get +1, mismatches get -1, then the substitution matrix is:
This substitution matrix can be described as:
Different base substitutions or amino acid substitutions can have different scores. The substitution matrix of amino acids is usually more complicated than that of the bases. See PAM, BLOSUM.
Gap penalty
Gap penalty designates scores for insertion or deletion. A simple gap penalty strategy is to use fixed score for each gap. In biology, however, the score needs to be counted differently for practical reasons. On one hand, partial similarity between two sequences is a common phenomenon; on the other hand, a single gene mutation event can result in insertion of a single long gap. Therefore, connected gaps forming a long gap usually is more favored than multiple scattered, short gaps. In order to take this difference into consideration, the concepts of gap opening and gap extension have been added to the scoring system. The gap opening score is usually higher than the gap extension score. For instance, the default parameters in EMBOSS Water are: gap opening = 10, gap extension = 0.5.
Here we discuss two common strategies for gap penalty. See Gap penalty for more strategies.
Let be the gap penalty function for a gap of length :
Linear
A linear gap penalty has the same scores for opening and extending a gap:
,
where is the cost of a single gap.
The gap penalty is directly proportional to the gap length. When linear gap penalty is used, the Smith–Waterman algorithm can be simplified to:
The simplified algorithm uses steps. When an element is being scored, only the gap penalties from the elements that are directly adjacent to this element need to be considered.
Affine
An affine gap penalty considers gap opening and extension separately:
,
where is the gap opening penalty, and is the gap extension penalty. For example, the penalty for a gap of length 2 is .
An arbitrary gap penalty was used in the original Smith–Waterman algorithm paper. It uses steps, therefore is quite demanding of time. Gotoh optimized the steps for an affine gap penalty to , but the optimized algorithm only attempts to find one optimal alignment, and the optimal alignment is not guaranteed to be found. Altschul modified Gotoh's algorithm to find all optimal alignments while maintaining the computational complexity. Later, Myers and Miller pointed out that Gotoh and Altschul's algorithm can be further modified based on the method that was published by Hirschberg in 1975, and applied this method. Myers and Miller's algorithm can align two sequences using space, with being the length of the shorter sequence. Chowdhury, Le, and Ramachandran later showed how to run Gotoh's algorithm cache-efficiently in linear space using a different recursive divide-and-conquer strategy than the one used by Hirschberg. The resulting algorithm runs faster than Myers and Miller's algorithm in practice due to its superior cache performance.
Gap penalty example
Take the alignment of sequences and as an example.
When linear gap penalty function is used, the result is (Alignments performed by EMBOSS Water. Substitution matrix is DNAfull (similarity score: +5 for matching characters otherwise -4). Gap opening and extension are 0.0 and 1.0 respectively):
When affine gap penalty is used, the result is (Gap opening and extension are 5.0 and 1.0 respectively):
This example shows that an affine gap penalty can help avoid scattered small gaps.
Scoring matrix
The function of the scoring matrix is to conduct one-to-one comparisons between all components in two sequences and record the optimal alignment results. The scoring process reflects the concept of dynamic programming. The final optimal alignment is found by iteratively expanding the growing optimal alignment. In other words, the current optimal alignment is generated by deciding which path (match/mismatch or inserting gap) gives the highest score from the previous optimal alignment. The size of the matrix is the length of one sequence plus 1 by the length of the other sequence plus 1. The additional first row and first column serve the purpose of aligning one sequence to any positions in the other sequence. Both the first line and the first column are set to 0 so that end gap is not penalized. The initial scoring matrix is:
Example
Take the alignment of DNA sequences and as an example. Use the following scheme:
Substitution matrix:
Gap penalty: (a linear gap penalty of )
Initialize and fill the scoring matrix, shown as below. This figure shows the scoring process of the first three elements. The yellow color indicates the bases that are being considered. The red color indicates the highest possible score for the cell being scored.
The finished scoring matrix is shown below on the left. The blue color shows the highest score. An element can receive score from more than one element, each will form a different path if this element is traced back. In case of multiple highest scores, traceback should be done starting with each highest score. The traceback process is shown below on the right. The best local alignment is generated in the reverse direction.
The alignment result is:
Implementation
An implementation of the Smith–Waterman Algorithm, SSEARCH, is available in the FASTA sequence analysis package from UVA FASTA Downloads. This implementation includes Altivec accelerated code for PowerPC G4 and G5 processors that speeds up comparisons 10–20-fold, using a modification of the Wozniak, 1997 approach, and an SSE2 vectorization developed by Farrar making optimal protein sequence database searches quite practical. A library, SSW, extends Farrar's implementation to return alignment information in addition to the optimal Smith–Waterman score.
Accelerated versions
FPGA
Cray demonstrated acceleration of the Smith–Waterman algorithm using a reconfigurable computing platform based on FPGA chips, with results showing up to 28x speed-up over standard microprocessor-based solutions. Another FPGA-based version of the Smith–Waterman algorithm shows FPGA (Virtex-4) speedups up to 100x over a 2.2 GHz Opteron processor. The TimeLogic DeCypher and CodeQuest systems also accelerate Smith–Waterman and Framesearch using PCIe FPGA cards.
A 2011 Master's thesis includes an analysis of FPGA-based Smith–Waterman acceleration.
In a 2016 publication OpenCL code compiled with Xilinx SDAccel accelerates genome sequencing, beats CPU/GPU performance/W by 12-21x, a very efficient implementation was presented. Using one PCIe FPGA card equipped with a Xilinx Virtex-7 2000T FPGA, the performance per Watt level was better than CPU/GPU by 12-21x.
GPU
Lawrence Livermore National Laboratory and the United States (US) Department of Energy's Joint Genome Institute implemented an accelerated version of Smith–Waterman local sequence alignment searches using graphics processing units (GPUs) with preliminary results showing a 2x speed-up over software implementations. A similar method has already been implemented in the Biofacet software since 1997, with the same speed-up factor.
Several GPU implementations of the algorithm in NVIDIA's CUDA C platform are also available. When compared to the best known CPU implementation (using SIMD instructions on the x86 architecture), by Farrar, the performance tests of this solution using a single NVidia GeForce 8800 GTX card show a slight increase in performance for smaller sequences, but a slight decrease in performance for larger ones. However, the same tests running on dual NVidia GeForce 8800 GTX cards are almost twice as fast as the Farrar implementation for all sequence sizes tested.
A newer GPU CUDA implementation of SW is now available that is faster than previous versions and also removes limitations on query lengths. See CUDASW++.
Eleven different SW implementations on CUDA have been reported, three of which report speedups of 30X.
Finally, other GPU-accelerated implementations of the Smith-Waterman can be found in NVIDIA Parabricks, NVIDIA's software suite for genome analysis.
SIMD
In 2000, a fast implementation of the Smith–Waterman algorithm using the single instruction, multiple data (SIMD) technology available in Intel Pentium MMX processors and similar technology was described in a publication by Rognes and Seeberg. In contrast to the Wozniak (1997) approach, the new implementation was based on vectors parallel with the query sequence, not diagonal vectors. The company Sencel Bioinformatics has applied for a patent covering this approach. Sencel is developing the software further and provides executables for academic use free of charge.
A SSE2 vectorization of the algorithm (Farrar, 2007) is now available providing an 8-16-fold speedup on Intel/AMD processors with SSE2 extensions. When running on Intel processor using the Core microarchitecture the SSE2 implementation achieves a 20-fold increase. Farrar's SSE2 implementation is available as the SSEARCH program in the FASTA sequence comparison package. The SSEARCH is included in the European Bioinformatics Institute's suite of similarity searching programs.
Danish bioinformatics company CLC bio has achieved speed-ups of close to 200 over standard software implementations with SSE2 on an Intel 2.17 GHz Core 2 Duo CPU, according to a publicly available white paper.
Accelerated version of the Smith–Waterman algorithm, on Intel and Advanced Micro Devices (AMD) based Linux servers, is supported by the GenCore 6 package, offered by Biocceleration. Performance benchmarks of this software package show up to 10 fold speed acceleration relative to standard software implementation on the same processor.
Currently the only company in bioinformatics to offer both SSE and FPGA solutions accelerating Smith–Waterman, CLC bio has achieved speed-ups of more than 110 over standard software implementations with CLC Bioinformatics Cube.
The fastest implementation of the algorithm on CPUs with SSSE3 can be found the SWIPE software (Rognes, 2011), which is available under the GNU Affero General Public License. In parallel, this software compares residues from sixteen different database sequences to one query residue. Using a 375 residue query sequence a speed of 106 billion cell updates per second (GCUPS) was achieved on a dual Intel Xeon X5650 six-core processor system, which is over six times more rapid than software based on Farrar's 'striped' approach. It is faster than BLAST when using the BLOSUM50 matrix.
An implementation of Smith–Waterman named diagonalsw, in C and C++, uses SIMD instruction sets (SSE4.1 for the x86 platform and AltiVec for the PowerPC platform). It is released under an open-source MIT License.
Cell Broadband Engine
In 2008, Farrar described a port of the Striped Smith–Waterman to the Cell Broadband Engine and reported speeds of 32 and 12 GCUPS on an IBM QS20 blade and a Sony PlayStation 3, respectively.
Limitations
Fast expansion of genetic data challenges speed of current DNA sequence alignment algorithms. Essential needs for an efficient and accurate method for DNA variant discovery demand innovative approaches for parallel processing in real time.
See also
Bioinformatics
Sequence alignment
Sequence mining
Needleman–Wunsch algorithm
Levenshtein distance
BLAST
FASTA
References
External links
JAligner — an open source Java implementation of the Smith–Waterman algorithm
B.A.B.A. — an applet (with source) which visually explains the algorithm
FASTA/SSEARCH — services page at the EBI
UGENE Smith–Waterman plugin — an open source SSEARCH compatible implementation of the algorithm with graphical interface written in C++
OPAL — an SIMD C/C++ library for massive optimal sequence alignment
diagonalsw — an open-source C/C++ implementation with SIMD instruction sets (notably SSE4.1) under the MIT license
SSW — an open-source C++ library providing an API to an SIMD implementation of the Smith–Waterman algorithm under the MIT license
melodic sequence alignment — a javascript implementation for melodic sequence alignment
DRAGMAP A C++ port of the Illumina DRAGEN FPGA implementation
Bioinformatics algorithms
Computational phylogenetics
Sequence alignment algorithms
Dynamic programming | Smith–Waterman algorithm | Biology | 4,190 |
1,416,042 | https://en.wikipedia.org/wiki/Fitting%20subgroup | In mathematics, especially in the area of algebra known as group theory, the Fitting subgroup F of a finite group G, named after Hans Fitting, is the unique largest normal nilpotent subgroup of G. Intuitively, it represents the smallest subgroup which "controls" the structure of G when G is solvable. When G is not solvable, a similar role is played by the generalized Fitting subgroup F*, which is generated by the Fitting subgroup and the components of G.
For an arbitrary (not necessarily finite) group G, the Fitting subgroup is defined to be the subgroup generated by the nilpotent normal subgroups of G. For infinite groups, the Fitting subgroup is not always nilpotent.
The remainder of this article deals exclusively with finite groups.
The Fitting subgroup
The nilpotency of the Fitting subgroup of a finite group is guaranteed by Fitting's theorem which says that the product of a finite collection of normal nilpotent subgroups of G is again a normal nilpotent subgroup. It may also be explicitly constructed as the product of the p-cores of G over all of the primes p dividing the order of G.
If G is a finite non-trivial solvable group then the Fitting subgroup is always non-trivial, i.e. if G≠1 is finite solvable, then F(G)≠1. Similarly the Fitting subgroup of G/F(G) will be nontrivial if G is not itself nilpotent, giving rise to the concept of Fitting length. Since the Fitting subgroup of a finite solvable group contains its own centralizer, this gives a method of understanding finite solvable groups as extensions of nilpotent groups by faithful automorphism groups of nilpotent groups.
In a nilpotent group, every chief factor is centralized by every element. Relaxing the condition somewhat, and taking the subgroup of elements of a general finite group which centralize every chief factor, one simply gets the Fitting subgroup again :
The generalization to p-nilpotent groups is similar.
The generalized Fitting subgroup
A component of a group is a subnormal quasisimple subgroup. (A group is quasisimple if it is a perfect central extension of a simple group.) The layer E(G) or L(G) of a group is the subgroup generated by all components. Any two components of a group commute, so the layer is a perfect central extension of a product of simple groups, and is the largest normal subgroup of G with this structure. The generalized Fitting subgroup F*(G) is the subgroup generated by the layer and the Fitting subgroup. The layer commutes with the Fitting subgroup, so the generalized Fitting subgroup is a central extension of a product of p-groups and simple groups.
The layer is also the maximal normal semisimple subgroup, where a group is called semisimple if it is a perfect central extension of a product of simple groups.
This definition of the generalized Fitting subgroup can be motivated by some of its intended uses. Consider the problem of trying to identify a normal subgroup H of G that contains its own centralizer and the Fitting group. If C is the centralizer of H we want to prove that C is contained in H. If not, pick a minimal characteristic subgroup M/Z(H) of C/Z(H), where Z(H) is the center of H, which is the same as the intersection of C and H. Then M/Z(H) is a product of simple or cyclic groups as it is characteristically simple. If M/Z(H) is a product of cyclic groups then M must be in the Fitting subgroup. If M/Z(H) is a product of non-abelian simple groups then the derived subgroup of M is a normal semisimple subgroup mapping onto M/Z(H). So if H contains the Fitting subgroup and all normal semisimple subgroups, then M/Z(H) must be trivial, so H contains its own centralizer. The generalized Fitting subgroup is the smallest subgroup that contains the Fitting subgroup and all normal semisimple subgroups.
The generalized Fitting subgroup can also be viewed as a generalized centralizer of chief factors. A nonabelian semisimple group cannot centralize itself, but it does act on itself as inner automorphisms. A group is said to be quasi-nilpotent if every element acts as an inner automorphism on every chief factor. The generalized Fitting subgroup is the unique largest subnormal quasi-nilpotent subgroup, and is equal to the set of all elements which act as inner automorphisms on every chief factor of the whole group :
Here an element g is in HCG(H/K) if and only if there is some h in H such that for every x in H, xg ≡ xh mod K.
Properties
If G is a finite solvable group, then the Fitting subgroup contains its own centralizer. The centralizer of the Fitting subgroup is the center of the Fitting subgroup. In this case, the generalized Fitting subgroup is equal to the Fitting subgroup. More generally, if G is a finite group, then the generalized Fitting subgroup contains its own centralizer. This means that in some sense the generalized Fitting subgroup controls G, because G modulo the centralizer of F*(G) is contained in the automorphism group of F*(G), and the centralizer of F*(G) is contained in F*(G). In particular there are only a finite number of groups with given generalized Fitting subgroup.
Applications
The normalizers of nontrivial p-subgroups of a finite group are called the p-local subgroups and exert a great deal of control over the structure of the group (allowing what is called local analysis). A finite group is said to be of characteristic p type if F*(G) is a p-group for every p-local subgroup, because any group of Lie type defined over a field of characteristic p has this property. In the classification of finite simple groups, this allows one to guess over which field a simple group should be defined. Note that a few groups are of characteristic p type for more than one p.
If a simple group is not of Lie type over a field of given characteristic p, then the p-local subgroups usually have components in the generalized Fitting subgroup, though there are many exceptions for groups that have small rank, are defined over small fields, or are sporadic. This is used to classify the finite simple groups, because if a p-local subgroup has a known component, it is often possible to identify the whole group .
The analysis of finite simple groups by means of the structure and embedding of the generalized Fitting subgroups of their maximal subgroups was originated by Helmut Bender and has come to be known as Bender's method. It is especially effective in the exceptional cases where components or signalizer functors are not applicable.
References
Finite groups
Functional subgroups | Fitting subgroup | Mathematics | 1,436 |
49,841,592 | https://en.wikipedia.org/wiki/Radiation%20detection | The following Radiological protection instruments can be used to detect and measure ionizing radiation:
Ionization chambers
Gaseous ionization detectors
Geiger counters
Photodetectors
Scintillation counters
Semiconductor detectors
Radioactivity
Radiation protection | Radiation detection | Physics,Chemistry | 45 |
616,775 | https://en.wikipedia.org/wiki/Loop%20I%20Bubble | The Loop I Bubble is a cavity in the interstellar medium (ISM) of the Orion Arm of the Milky Way. From our Sun's point of view, it is situated towards the Galactic Center of the Milky Way galaxy. Two conspicuous tunnels connect the Local Bubble with the Loop I Bubble cavity (the Lupus Tunnel). The Loop I Bubble is a supershell.
The Loop I Bubble is located roughly 100 parsecs, or 330 light years, from the Sun. The Loop I Bubble was created by supernovae and stellar winds in the Scorpius–Centaurus association, some 500 light years from the Sun. The Loop I Bubble contains the star Antares (also known as Alpha Scorpii). Several tunnels connect the cavities of the Local Bubble with the Loop I Bubble, called the "Lupus Tunnel".
See also
Local Bubble
Orion Arm
Superbubble
References
Interstellar media
Orion–Cygnus Arm | Loop I Bubble | Astronomy | 196 |
1,792,688 | https://en.wikipedia.org/wiki/Combo%20television%20unit | A combo television unit, or a TV/VCR combo, sometimes known as a televideo, is a television with a VCR, DVD player, or sometimes both, built into a single unit.
Types
TV/VCR combos
During the era of their popularity, many of these units displayed product videos in stores or for other commercial displays. The main reason for this was that unlike most low-end, standalone VCRs, many included an automatic repeat play feature.
TV/Computer combos
Some fully functional computer systems or game consoles have been built into some models of TVs over time. Hewlett-Packard currently has a version of their TouchSmart line of computers with a built-in TV tuner, and even has a built-in DVR; also making it a TV/DVR combo which is a relatively rare concept. As of late 2006, Samsung introduced an LED TV with a proprietary operating system with Internet access to websites like Facebook, YouTube, Hulu, Netflix, and other sites. Other TV/computer combo equipment can simply just be flatscreen TVs with USB ports which allows USB flash drives and external hard drives to be connected to allow for audio and video playback, in which it can give a streamlined, fully solid-state profile.
Almost all modern-day TV sets have simplified CPUs and memory chips for basic functions such as channels and video settings, and video timing for LCD flat panels; however these examples are not sophisticated enough to qualify as significant examples. Other computer parts are used for real-time playback of DVDs on combo TVs with DVD player (and Blu-ray Disc for more high-end models) functionality; however these dedicated functions alone don't qualify as significant examples either.
In the modern day, the distinction between a combo TV and an all-in-one PC have blurred with the modern smart TV concept.
In 2010, Sony introduced a TV with a built-in PlayStation 2.
See also
Handheld television
VCR/DVD combo
VCR/Blu-ray combo
Internet television, the software equivalent of a TV/computer combo
References
Television technology
Video hardware
Television sets | Combo television unit | Technology,Engineering | 432 |
15,686,634 | https://en.wikipedia.org/wiki/World%27s%20largest%20weather%20vane | According to the Guinness World Records, the world's largest weather vane is located in Jerez, Spain.
According to the explore north website a challenger for the title of world's largest weather vane is located in Whitehorse, Yukon. The weather vane is a retired Douglas DC-3 atop a swiveling support. Located beside the Whitehorse airport the weather vane is used mainly by pilots to determine wind direction. This weather vane only requires a 5 km/hour wind to rotate.
Other claimants to the title are located in:
Westlock, Alberta, Canada: The Canadian Tractor Museum is home to the tallest functioning weather vane at 50 feet. This weather vane was erected in 2006 with a 1942 Case Model D Tractor atop it after being a volunteer project for 2 years.
Montague, Michigan, USA: Montague is home to the "World's Largest Working Weathervane" which was constructed in part by local manufacturer Whitehall Metal Studios. Originally located on a man-made peninsula that jutted out into the waters at the Northeast end of White Lake, it was moved to the corner of Dowling & Water Streets in Montague. The functioning weathervane is 48 feet tall with an arrow 26 feet long. It is topped by the Ella Ellenwood, a lumbering Schooner that frequented White Lake transporting lumber from Montague to Milwaukee, Wisconsin.
References
Meteorological instrumentation and equipment | World's largest weather vane | Technology,Engineering | 281 |
71,232,931 | https://en.wikipedia.org/wiki/Steven%20M.%20Cron | Steven M. Cron is a retired Michelin product research engineer and co-inventor of the Tweel.
Cron began his engineering education with a BS Mechanical Engineering degree from the University of Missouri-Columbia in 1984. In 1985, he completed an MS degree in aeronautical engineering from the U. S. Air Force Institute of Technology at Wright-Patterson Air Force Base. He then continued with the Air Force for 6 years as a project engineer working on ICBMs and as an instructor of Engineering Mechanics at the US Air Force Academy. He began his career at Michelin in 1991 as a research engineer. He had initial assignments in the area of tire vibrations, specifically damped modal analysis of pneumatic tires via the finite element method.
He began work on airless tire technology as early as 1997, with work on the Tweel occurring over the period 2000-2009. Although other airless tire concepts have been studied or attempted in the past, none has achieved the commercial success of the Tweel, which is based on the framework and approach pioneered by Cron and co-inventor Timothy B. Rhyne.
In 2018, Cron received the Harold Herzlich Distinguished Technology award. At the time, Cron said that work on the Tweel began informally, starting with the idea that the load of the vehicle should be carried in the tire structure by means of tension, as happens in a traditional pneumatic tire. After realizing that cord tension carried via the sidewall would not work with zero inflation pressure, a successful experiment with polyurethane spokes lead to the basic Tweel design.
In 2021, Cron and co-inventor Timothy B. Rhyne were jointly awarded the Charles Goodyear Medal, the highest honor conferred by the American Chemical Society, Rubber Division. It was the first time that the award was given jointly.
References
Polymer scientists and engineers
Tire industry people
Year of birth missing (living people)
Place of birth missing (living people)
University of Missouri alumni
Air Force Institute of Technology alumni
Living people
Michelin people | Steven M. Cron | Chemistry,Materials_science | 419 |
2,439,851 | https://en.wikipedia.org/wiki/Erythranthe%20guttata | Erythranthe guttata, with the common names seep monkeyflower and common yellow monkeyflower, is a yellow bee-pollinated annual or perennial plant. It was formerly known as Mimulus guttatus.
Erythranthe guttata is a model organism for biological studies, and in that context is still referred to as Mimulus guttatus. There may be as many as 1000 scientific papers focused on this species. The genome is (as of 2012) being studied in depth.
For combined research of evolution, genetics, and ecology, particularly plant-insect interactions, the yellow monkeyflower has become a model system. With the help of physically resistant protections called trichomes, which have been thoroughly examined, the yellow monkeyflower defends itself against herbivores.
Description
A highly variable plant, taking many forms, E. guttata is a species complex in that there is room to treat some of its forms as different species by some definitions.
The plant ranges from tall with disproportionately large, 2 to 4 cm long, tubular flowers. The perennial form spreads with stolons or rhizomes. The stem may be erect or recumbent. In the latter form, roots may develop at leaf nodes. Sometimes dwarfed, it may be hairless or have some hairs.
Leaves are opposite, round to oval, usually coarsely and irregularly toothed or lobed. The bright yellow flowers are born on a raceme, most often with five or more flowers.
The calyx has five lobes that are much shorter than the flower. Each flower has bilateral symmetry and has two lips. The upper lip usually has two lobes; the lower, three. The lower lip may have one large to many small red to reddish brown spots (hence the name guttata, which is Latin for 'spotted'). The opening to the flower is hairy.
Erythranthe guttata is pollinated by bees, such as Bombus species. Inbreeding reduces flower quantity and size and pollen quality and quantity. E. guttata also displays a high degree of self-pollination. Erythranthe nasuta (Mimulus nasutus) evolved from E. guttata in central California between 200,000 and 500,000 years ago and since then has become primarily a self-pollinator. Other differences have occurred since then, such as genetic code variations and variations in plant morphology. E. guttata prefers a wetter habitat than E. nasuta.
Distribution and habitat
A herbaceous wildflower, Erythranthe guttata grows along the banks of streams and seeps throughout much of western North America from sea level to . Both annual and perennial forms occur throughout the species' range. It blooms during spring at low elevations, during summer at high elevations.
It is found in a wide range of habitats including the splash zone of the Pacific Ocean, the chaparral of California, Western U.S. deserts, the geysers of Yellowstone National Park, alpine meadows, serpentine barrens, and even on the toxic tailings of copper mines. It is also very common in New Zealand near water bodies.
The flower is also an introduced species in Europe.
Cultivation
Erythranthe guttata is cultivated in the specialty horticulture trade and available as an ornamental plant for: traditional gardens; natural landscape, native plant, and habitat gardens.
Uses
The leaves are edible, both raw and cooked. Leaves are sometimes added to salads as a lettuce substitute, they have a slight bitter flavour.
References
External links
Calflora: Mimulus guttatus'' (Seep Monkey Flower, Yellow Monkey Flower, common yellow monkeyflower)
University of Michigan - Dearborn, Native American Ethnobotany:
Mimulus Genome Browser - for genetics researchers
Mimulus guttatus — UC Photos gallery
guttata
Flora of the Northwestern United States
Flora of the Southwestern United States
Flora of Western Canada
Flora of the West Coast of the United States
Flora of British Columbia
Flora of California
Flora of the California desert regions
Flora of the Sierra Nevada (United States)
Natural history of the California chaparral and woodlands
Plant models
Garden plants of North America
Freshwater plants
Leaf vegetables
Flora without expected TNC conservation status | Erythranthe guttata | Biology | 879 |
26,407,042 | https://en.wikipedia.org/wiki/G.%20D.%20Agrawal | Guru das Agrawal, also known as Sant Swami Sanand and Sant Swami Gyan Swaroop Sanand (20 July, 1932 – 11 October, 2018), was an Indian environmentalist, engineer, religious leader, monk, and professor. He was the Patron of Ganga Mahasabha, founded by Madan Mohan Malviya in 1905.
He is notable for several fasts undertaken to stop many projects on the River Ganga. His fast in 2009 led to the damming of the Bhagirathi River being stopped.
Agrawal died on 11 October 2018, after fasting since 22 June 2018, demanding the government act on its promises to clean and save the Ganga.
Early life
Born to a farming family in Kandhla, Muzaffarnagar district, Uttar Pradesh, in 1932, he studied in local primary and secondary schools. He graduated in civil engineering from the University of Roorkee (now IIT Roorkee). While he was the member secretary of the Central Pollution Control Board during 1979 – 1980, he was also a visiting professor for environmental engineering at the University of Roorkee.
In July 2011, he became a Hindu sannyasi and Swami Gyanswaroop Sanand.
Environmental activism
Background
Despite numerous protests and representations by local citizens, 6 hydroelectric power-plant dams were planned, seeking clearance or already under construction, on a stretch of the Bhagirathi River's length. This run is from the river's source at the Gangotri Glacier to the remote town of Uttarkashi in the Himalayan foothills. In pursuit of its energy intensive plan for economic growth, the Indian government had hastily pushed hydroelectric generating projects on the river, destroying what many describe as the traditional Indian ethos of worshipping and living in harmony with nature.
2009
Agrawal started a fast on 13 June 2009 at Uttarkashi. His demand was minimal and specific, i.e. to allow the flow of the Ganges in its original channel in this stretch from its origin. This is the only stretch left where the Ganges can still be seen undisturbed by man. The free-running of the river is a crucial element of its sacred status.
Before his fast began in January, Agrawal said, "The water ...(of the Ganges) is not ordinary water to a Hindu. It is a matter of life and death of Hindu faith".
An allegation by Uttarakhand Minister
Diwakar Bhatt, in a press conference, alleged that "It may be that the Central Intelligence Agency (CIA) of the US or Pakistan's Inter Service Intelligence (ISI) are behind these so-called anti-hydro projects in Uttarakhand, as by doing so they are hampering the development of the state and ultimately of India. So, they are traitors and should be opposed by people too."
2013
In mid-June 2013, Agrawal began his fast in the wake of the inactivity of National Ganga River Basin Authority. He stopped taking water on 21 September as his fast entered its 101st day. Due to government's apathy towards Agrawal's fast, three members of the national Ganga River Basin Authority, Rajendra Singh, Ravi Chopra and Rashid Siddiqui resigned.
2018
In February 2018, Agrawal sent an open letter to Prime Minister Narendra Modi urging him to stop environmentally unfriendly projects and ensure what he calls the 'aviral' flow of the river in the upper stretches of the river Ganga. He reminded the prime minister that "It will be four years in May when the Central government will complete four years in office, but nothing has been done so far for the cause of Ganga".
Agrawal had mentioned in the letter that if no action is taken by Ganga Dussehra (22 June 2018), he will go on fast-unto-death. He wrote another letter to PM on 13 June. After receiving no response from the government, he began his fast on 22 June at Haridwar.
On the 19th day of his fast, police evicted him from his fast venue to AIIMS Rishikesh. Based on a petition filed by Agrawal against forced eviction, Uttarakhand high-court stepped in and said he needs to be taken to hospital only if his health is in danger.
The government responded to Agrawal's fast via Nitin Gadkari (Union Minister for Water Resources, River Development and Ganga Rejuvenation), but it failed to resolve the impasse. Agrawal alleged that government is focusing on the cleaning river Ganga whereas his holistic vision ensures 'aviral-nirmal' Ganga.
On 13 August (53rd day of the fast), Agrawal was admitted to AIIMS again.
On 9 October (the 109th day of the fast), he stopped drinking water and refused to take medicine, water or any fluid/juice orally. However, he gave written consent to doctors for administering potassium orally and drip to provide 500ML saline fluid per day to maintain the minimum fluid and electrolyte needs of the body.
On 11 October (the 111th day of the fast), he died from starvation, aged 86.
Dam stopped
Work on the Loharinag Pala Hydro Power Project was stopped when Agrawal came close to dying on the 38th day of his fast in protest of the harnessing of the river Bhagirathi. In a letter dated 19 February 2009 to Agrawal, the Ministry of Power stated that it had ordered the immediate suspension of work on the Loharinag-Pala Hydropower Project on the Bhagirathi River. In response, Agrawal ended his fast the following day at 11:00 am. The Indian government agreed to speed up its inquiry into how electricity could be generated without the flow of the Ganges being impeded.
Agrawal's devotion to the River Ganges comes from his strong Hindu faith and conviction that India is staring at an unprecedented ecological and cultural catastrophe. As a citizen and a patriot, he has made it his life's mission to recall India to its traditional reverence for nature and to share that wisdom with the "developed" world. His sense of duty allows him to do no less.
National Ganges River Basin Authority
His campaign was taken up by leaders of the opposition party, who called for stopping all dam constructions upstream of the river. The Government of India was quick to commit itself to ensure perennial environmentally acceptable flows throughout the river and informing Agrawal of the same. The Government then went a step ahead and declared the Ganges a National River and set up the National Ganga River Basin Authority (NGRBA) as an empowered planning, implementing, and monitoring authority for the Ganges.
On 4 November 2009, in New Delhi, Prime Minister Manmohan Singh, also the chairman of NGRBA, directed the concerned officials to expedite of the National Ganges River Basin Research Institute (NGRBRI). The Centre for Environmental Studies and Technology (CEST), Banaras Hindu University was named the research institute that would act as knowledge centre for collecting and analysing all relevant data concerning the Ganges basin.
The objectives of NGRBRI are to:
generate primary ecological data required by NGBRA for short and long-term planning of sustainable development of the Ganges River basin
investigate the hydrology and pollution problems along the river basin
study social, cultural and religious dimensions and develop eco-friendly technologies for sustainable development
act as the knowledge centre for the collection and analysis of all relevant data concerning the Ganges basin
create long-term models for future planning for maintaining water quality and its varied sustainable uses
On 10 February 2010, Union Minister of State (Independent Charge) for Environment and Forests Jairam Ramesh, addressing the GangesYamuna summit organised by the Nehru Memorial Library and Museum said: "I have said in the Parliament that India is a civilisation of rivers, and it should not become a land of tunnels." He said some new projects on Bhagirathi River would not be allowed. "There are no two opinions. There is just one mass opinion that the projects proposed on the river Bhagirathi, named Pala Maneri and Bhaironghati projects, will not be entertained further by the government."
References
External links
Prof. Agrawal's Letter regarding 'Fasting Unto Death' Pramod-Van, Chitrakoot, M.P. Date: 14 April 2008, Re: My Intention of "Fasting Unto Death" for Conservation of Bhagirathi
News clippings related to Agrawal's fast-unto-death
, Video – 8:41; , Video 9:39; , Video 8:25
G.D. Agrawal's Third and Final Letter to PM Modi on Saving the Ganga
‘Ganges Crusader GD Agrawal Murdered,’ Aide Attacks Modi, Gadkari
1932 births
2018 deaths
Indian environmentalists
UC Berkeley College of Engineering alumni
IIT Roorkee alumni
Hindu activists
20th-century Indian engineers
IIT Kanpur people
Environmental engineers
People who died on hunger strike
People from Muzaffarnagar district | G. D. Agrawal | Chemistry,Engineering | 1,873 |
1,181,942 | https://en.wikipedia.org/wiki/Arguments%20for%20and%20against%20drug%20prohibition | Commonly-cited arguments for and against the prohibition of drugs include the following:
Efficiency
Arguments that drug laws are effective
Supporters of prohibition claim that drug laws have a successful track record suppressing illicit drug use since they were introduced in the 1910s. The licit drug alcohol has current (last 12 months) user rates as high as 80–90% in populations over 14 years of age, and tobacco has historically had current use rates up to 60% of adult populations, yet the percentages currently using illicit drugs in OECD countries are generally below 1% of the population excepting cannabis where most are between 3% and 10%, with six countries between 11% and 17%.
In the 50-year period following the first 1912 international convention restricting use of opium, heroin and cocaine, the United States' use of illicit drugs other than cannabis was consistently below 0.5% of the population, with cannabis rising to 1–2% of the population between 1955 and 1965. With the advent of the counter-culture movement from the late 1950s, where illicit drug use was promoted as mind-expanding and relatively harmless, illicit drug use rose sharply. With illicit drug use peaking in the 1970s in the United States, the "Just Say No" campaign, initiated under the patronage of Nancy Reagan, coincided with recent (past month) illicit drug use decreases from 14.1% in 1979 to 5.8% in 1992, a drop of 60%.
In March, 2007, Antonio Maria Costa, former executive director of the United Nations Office on Drugs and Crime, drew attention to the drug policy of Sweden, arguing:
In Europe as of 2007, Sweden spends the second highest percentage of GDP, after the Netherlands, on drug control. The UNODC argues that when Sweden reduced spending on education and rehabilitation in the 1990s in a context of higher youth unemployment and declining GDP growth, illicit drug use rose but restoring expenditure from 2002 again sharply decreased drug use as student surveys indicate. In 1998, a poll run by SIFO of 1,000 Swedes found that 96% wanted stronger action by government to stop drug abuse, and 95% wanted drug use to remain illegal.
Criticizing governments that have relaxed their drug laws, Antonio Maria Costa, speaking in Washington before the launch of the World Drug Report in June 2006, said:
Arguments that drug laws are ineffective
One of the prominent early critics of prohibition in the United States was August Vollmer, founder of the School of Criminology at University of California, Irvine and former president of the International Association of Chiefs of Police. In his 1936 book The Police and Modern Society, he stated his opinion that:
Stephen Rolles, writing in the British Medical Journal in 2010, argues:
These conclusions have been reached by a succession of committees and reports including, in the United Kingdom alone, the Police Foundation, the Home Affairs Select Committee, the Prime Minister's Strategy Unit, the Royal Society of Arts, and the UK Drug Policy Consortium. The United Nations Office of Drugs and Crime has also acknowledged the many "unintended negative consequences" of drug enforcement.
The editor of the British Medical Journal, Dr. Fiona Godlee, gave her personal support to Rolles' call for decriminalisation, and the arguments drew particular support from Sir Ian Gilmore, former president of the Royal College of Physicians, who said we should be treating drugs "as a health issue rather than criminalising people" and "this could drastically reduce crime and improve health".
Danny Kushlik, head of external affairs at Transform, said the intervention of senior medical professionals was significant. He said: "Sir Ian's statement is yet another nail in prohibition's coffin. The Hippocratic oath says: 'First, do no harm'. Physicians are duty bound to speak out if the outcomes show that prohibition causes more harm than it reduces."
Nicholas Green, chairman of the Bar Council, made comments in a report in the profession's magazine, in which he said that drug-related crime costs the UK economy about £13bn a year and that there was growing evidence that decriminalisation could free up police resources, reduce crime and recidivism and improve public health.
A 2006 report sponsored by the New York County Lawyers' Association, one of the largest local bar associations in the United States, argues on the subject of US drug policy:
In response to claims that prohibition can work, as argued by Antonio Maria Costa, executive director of the United Nations Office on Drugs and Crime, who drew attention to the drug policy of Sweden, Henrik Tham has written in 1998 that sometimes it's domestically important to stress drug policy as successful; in the case of Sweden, where this notion is important, such claims serve "the function of strengthening a threatened national identity in a situation where the traditional 'Swedish model' has come under increasingly hard attack from both inside and outside the country." Tham questions the success of the Swedish model – "The shift in Swedish drug policy since around 1980" ...(more difficult to receive nolle prosequi for minor drug crimes) ..."towards a more strict model has according to the official point of view been successful by comparison with the earlier, more lenient drug policy. However, available systematic indicators show that the prevalence of drug use has increased since around 1980, that the decrease in drug incidence was particularly marked during the 1970s and that some indicators point towards an increase during the 1990s."
Leif Lenke and Börje Olsson from Stockholm University have conducted research that showed how drug use have followed the youth unemployment in close correlation. They noted that unlike most of Europe, Sweden did not have widespread and lingering youth unemployment until the early 1990s financial crisis, suggesting that unattractive future prospects may contribute to the increase in drug use among the young. CAN, the Swedish Council for Information on Alcohol and Other Drugs, 2009 report stated that the increase in drug use have continued since the 1990s with a slight dip in the mid-2000.
The professor emeritus in criminology at the University of Oslo, Nils Christie, pointed out Sweden as the hawk of international drug policy in a 2004 book. He said that Sweden is serving the role of being welfare alibi for, and lending legitimacy to, the US drug war. Adding that USA and Sweden have had an extraordinary influence on UNODC as the biggest donor countries. Sweden was the second biggest donor financing 8% of the UNODC budget behind the European Commission in 2006, followed by the US. In 2007 and 2008 Sweden was the fourth biggest donor, behind the European Commission, USA and Canada. In 2009 it was the third, as USA withdrew some of its funding.
A 2009 editorial in The Economist argued:
Antonio Maria Costa's conviction that "countries have the drug problem they deserve" if they fail to follow the "Swedish Model" in drug control has also been criticised in Peter Cohen's work – Looking at the UN, smelling a rat.
In its 2011 report, the Global Commission on Drug Policy stated that "The global war on drugs has failed, with devastating consequences for individuals and societies around the world".
Deterrence
Arguments that prohibition discourages drug use
A 2001 Australian study, of 18- to 29-year-olds by the NSW Bureau of Crime Statistics and Research suggests that prohibition deters illicit drug use. 29% of those who had never used cannabis cited the illegality of the substance as their reason for never using the drug, while 19% of those who had ceased use of cannabis cited its illegality as their reason.
Gil Kerlikowske, director of the US ONDCP argued,
The DEA argues "Legalization has been tried before—and failed miserably. Alaska's experiment with legalization in the 1970s led to the state's teens using marijuana at more than twice the rate of other youths nationally. This led Alaska's residents to vote to re-criminalize marijuana in 1990."
Drug Free Australia has cited the Netherlands as an example of drug policy failure because it is soft in approach. They argue that the Dutch idea of going soft on cannabis dealers, thereby creating a "separation of markets" from hard drug dealers has failed to stem the initiation to drugs such as heroin, cocaine, and amphetamines, saying that, in 1998, the Netherlands had the third highest cannabis and cocaine use in Europe. According to Barry McCaffrey of the US Office of National Drug Control Policy, Dutch tolerance has allowed the Netherlands to become a criminal epicentre for illicit synthetic drug manufacture, particularly ecstasy, as well as the home for production and worldwide export of strains of cannabis with THC reportedly 10 times higher than normal. Gil Kerlikowske has attested that, where there were once thousands of cannabis cafés there are now only several hundred. Levels of cannabis use, in 2005 only marginally higher than in 1998, while other European countries have accelerated past them, are more likely, Drug Free Australia argues, the result of a growing intolerance of cannabis in the Netherlands rather than a growing tolerance. Drug Free Australia has also argued that British reductions in cannabis use after softer legislation may be more so the result of heavy UK media exposure of the stronger evidence of links between cannabis and psychosis.
Arguments that prohibition does not discourage drug use
It has been suggested that drug law reform could reduce the use of hard drugs as it has in countries such as the Netherlands. According to a 2009 annual report by the European Monitoring Centre for Drugs and Drug Addiction, the Dutch are among the lowest users of marijuana or cannabis in Europe, despite the Netherlands' policy on soft drugs being one of the most liberal in Europe, allowing for the sale of marijuana at "coffee shops", which the Dutch have allowed to operate for decades, and possession of less than .
British Crime Survey statistics indicated that the proportion of 16- to 24-year-olds using cannabis decreased from 28% a decade ago to 21%, with its declining popularity accelerating after the decision to downgrade the drug to class C was announced in January 2004. The BCS figures, published in October 2007, showed that the proportion of frequent users in the 16–24 age group (i.e. who were using cannabis more than once a month), fell from 12% to 8% in the past four years.
American teenagers are drinking and smoking less and doing fewer drugs than their predecessors in more than 40 years of tracking. Use of marijuana is down among 8th- and 10th-graders, though it is flat among high school seniors, according to the annual Monitoring the Future survey of American teens.
A 2008 scholarly study found that intensified enforcement of marijuana laws does not achieve the stated goals of
marijuana prohibition and that "decriminalizing marijuana possession or deprioritizing marijuana law enforcement does not appear to increase marijuana use".
Gateway drug theory
Arguments that cannabis is a gateway drug
The US Drug Enforcement Agency's "2008 Marijuana Sourcebook" argues that recent research supports the gateway hypothesis that certain drugs (such as cannabis) act as gateways to use of 'harder' drugs such as heroin, either because of social contact or because of an increasing search for a better high. Proponents cite studies such as that of 311 same sex twins, where only one twin smoked cannabis before age 17, and where such early cannabis smokers were five times more likely than their twin to move on to harder drugs.
Arguments that cannabis is not a gateway drug
In the American Journal of Public Health, Andrew Golub and Bruce Johnson of the National Development and Research Institute in New York wrote that young people who smoked marijuana in the generations before and after the baby boomers did not appear to be likely to move on to harder drugs.
Researchers from the independent Rand Drug Policy Research Center in Santa Monica, California, looking at data from the National Household Survey on Drug Abuse between 1982 and 1994, concluded that teenagers who took hard drugs did so whether they had first tried cannabis or not.
A twin study (of 510 same sex twin pairs) which adjusted for additional confounders such as peer drug use, found that cannabis use and associations with later hard drug use existed only for non-identical twins. The study suggested that a causal role of cannabis use in later hard drug usage is minimal, if it exists at all, and that cannabis use and hard drug use share the same influencing factors such as genetics and environment.
Health
Health arguments for drug laws
Advocates of prohibition argue that particular drugs should be illegal because they are harmful. Drug Free Australia for example argues "That illicit drugs are inherently harmful substances is attested by the very nomenclature of the 'harm reduction' movement." The U.S. government has argued that illegal drugs are "far more deadly than alcohol" saying "although alcohol is used by seven times as many people as drugs, the number of deaths induced by those substances is not far apart. According to the Centers for Disease Control and Prevention (CDC), during 2000, there were 15,852 drug-induced deaths; only slightly less than the 18,539 alcohol-induced deaths." Ratios of the harms of illicit opiates to licit alcohol and tobacco in Australia are similar, with 2 deaths per hundred opiate users per annum versus 0.22 deaths per hundred for alcohol (9 times less) per year and 0.3 for tobacco (7 times less).
The DEA has said:
Many of the deaths from using cannabis, other than from car accidents while intoxicated or violence and aggression, are more likely to figure in the longer term, just as with tobacco, where both nicotine overdose and cannabis overdose are extremely rare or nonexistent. While ecstasy may have lower rates of immediate mortality than some other illicits, there is a growing science on the already recognized considerable health harms of ecstasy. Drug Free Australia argues that distinctions between "soft" and "hard" drugs are entirely artificial, and titling cannabis "soft" or ecstasy "recreational" does not lessen the extensive harms of these substances.
Gil Kerlikowske, former director of the US Office of National Drug Control Policy (ONDCP) argues that in the United States, illegal drugs already cost $180 billion a year in health care, lost productivity, crime, and other expenditures, and that number would only increase under legalization because of increased use.
Drug Free Australia claims arguments that increased health harms of illicit drugs are the result of lack of government regulation of their purity and strength are not well supported by evidence. In Australia, which has had the highest opioid mortality per capita in the OECD, studies found that "overdose fatality is not a simple function of heroin dose or purity. There is no evidence of toxicity from contaminants of street heroin in Australia." Drug Free Australia claims that other causes of death such as suicide, murder and accidents are an effect of the drug themselves, not of their purity or otherwise.
Addiction
Drug Free Australia argues "Regarding the freedom of choice of those addicted to a drug, it is important to recognize that addiction is defined as compulsive by its very nature and that addictions curb individual freedom." ... "As is the case with alcohol addiction, illicit drug addictions likewise serve to keep many such users functionally in poverty and often as a continued burden on friends, family and society. Where it is argued that all disabilities are a burden on society it must be recognized that most disabilities are not the result of a choice, whereas the decision to recreationally use illicit drugs is most commonly free, and with the knowledge that they may lead to an abundance of addictions."
Health arguments for drug law reform
There is evidence that many illicit drugs pose comparatively fewer health dangers than certain legal drugs. The health risks of MDMA (Ecstasy) have been exaggerated for instance, the risks from cannabis use also overstated, and health problems from the use of legal substances, particularly alcohol and tobacco, are greater, even than from cocaine use for example (occasional cocaine use does not typically lead to severe or even minor physical or social problems).
Health benefits
A 2015 study of 135,095 U.S. adults found no significant link between lifetime psychedelic use and increased mental health problems or suicidal behavior. The researchers concluded that the prohibition of psychedelics is challenging to justify on public health grounds, given these findings.
Many trials have shown beneficial effects associated with psychoactive drug use:
There is evidence that MDMA (ecstasy) can treat or cure post-traumatic stress disorder and anxiety in cases of terminal illness.
LSD has been widely researched as a therapeutic agent, and has shown effectiveness against alcoholism, frigidity and various other disorders. See Psychedelic therapy.
Researchers at Harvard-affiliated McLean Hospital found members of a religious group regularly using peyote scored significantly better on several measures of overall mental health than did subjects who did not use the hallucinogen.
A 2007 study, by Santos et al. found that users of ayahuasca scored better on tests measuring anxiety and hopelessness than people who did not use the drug.
Quality control
According to a World Health Organisation report: "As cannabis is an illegal drug its cultivation, harvesting and distribution are not subject to quality control mechanisms to ensure the reliability and safety of the product used by consumers. It is well recognised in developing countries, such as Kenya, that illicit alcohol production can result in the contamination with toxic by-products or adulterants that can kill or seriously affect the health of users. The same may be true of illicit drugs such as opiates, cocaine and amphetamine in developed societies."
The government cannot enforce quality control on products sold and manufactured illegally. Examples include: the easier to make derivative MDA being sold as MDMA, heroin users unintentionally injecting brick dust, quinine, or fentanyl with which their heroin had been cut; and heroin/cocaine overdoses occurring as a result of users not knowing exactly how much they are taking. If the supply of drugs such as ecstasy came from legitimate pharmaceutical companies, their product would be far less likely to contain toxic additives or varying dosages. This is a view supported by a number of parents whose children have died of overdoses.
The illegality of injectable drugs leads to a scarcity of needles which causes an increase in HIV infections. An easy cure to this problem, while upholding the illegality of drugs, is the Dutch policy of distributing free needles. The money spent on both increased health costs due to HIV infections and drug prohibition itself causes a drain upon society.
Studies on the effects of prescribing heroin to addicts as practiced in many European countries have shown better rates of success than any other available treatment in terms of assisting long-term users establish stable, crime-free lives. Many patients were able to find employment, some even started a family after years of homelessness and delinquency.
Block to research
The illegality of many recreational drugs may be dissuading research into new, more effective and perhaps safer recreational drugs, despite evidence that their use may be beneficial in certain contexts. Research on Schedule I drugs in many countries, including the United States and United Kingdom, and under international law, is tightly regulated and requires expensive and hard-to-obtain permits. Such restrictions have largely prevented investigation of their properties and therapeutic uses, and most research since the passage of the drug laws focuses on negative impacts of these drugs. For example, all known agonists of the 5HT2A receptor are psychedelics, which prevents research into this receptor.
In particular, research suggests that recreational drugs may have psychiatric applications, which many demonstrating potential for treatment-resistant mental health conditions, such as depression and anxiety. Those who support the legalisation of recreational drugs for research purposes highlight that it is unethical not to conduct research into therapeutic interventions that may have the potential to treat these conditions.
Misleading health statistics
The United States Drug Enforcement Administration (DEA) has suggested that illegal drugs are "far more deadly than alcohol", arguing that "although alcohol is used by seven times as many people as drugs, the number of deaths induced by those substances is not far apart", quoting figures from the Centers for Disease Control and Prevention (CDC), claiming "during 2000, there were 15,852 drug-induced deaths; only slightly less than the 18,539 alcohol-induced deaths."
The DEA's use of such figures is questionable however. An article in the Journal of the American Medical Association gave the number deaths caused by alcohol in year 2000 as 85,000 – over four and a half times greater than the DEA's preferred figure. The DEA's argument also overlooks tobacco, causing 435,000 US deaths in year 2000. And, the CDC definition of "drug-induced death" includes suicides using drugs, accidental overdose, and deaths from medically prescribed (not illegal) drugs. An analysis of drug-induced deaths for the 20-year period 1979–1998 found the vast majority attributable to accidental overdose, and suicide by drug taking, which together account for about 76 percent of all such deaths. Taking into account deaths from non-illegal drugs leaves only 21 percent of CDC "drug-induced death" figures actually due to the use of "illegal" drugs.
Claims that cannabis is far more powerful than it used to be are also dubious, with "scare figures" skewed by comparing the weakest cannabis from the past with the strongest of today. Figures regarding emergency room mentions of marijuana use can be misleading too, as "mention" of a drug in an emergency department visit does not mean that the drug was the cause of the visit.
Medical uses
A document published for the non-profit advocacy organization Europe Against Drugs (EURAD) argues that "one cannot vote for a medicine" and that a scientific approval basis is essential. It says that EU rules set out strict criteria for the acceptance of a drug for medical use:
Arguments against medical uses of prohibited drugs
According to Janet D. Lapey, M.D., of Concerned Citizens For Drug Prevention, " Due to a placebo effect, a patient may erroneously believe a drug is helpful when it is not. This is especially true of addictive, mind-altering drugs like marijuana. A marijuana withdrawal syndrome occurs, consisting of anxiety, depression, sleep and appetite disturbances, irritability, tremors, diaphoresis, nausea, muscle convulsions, and restlessness. Often, persons using marijuana erroneously believe that the drug is helping them combat these symptoms without realizing that actually marijuana is the cause of these effects. Therefore, when a patient anecdotally reports a drug to have medicinal value, this must be followed by objective scientific studies."
The US Drug Enforcement Administration also says:
Arguments for medical uses of prohibited drugs
Most of the psychoactive drugs now prohibited in modern societies have had medical uses in history. In natural plant drugs like opium, coca, cannabis, mescaline, and psilocybin, the medical history usually dates back thousands of years and through a variety of cultures.
Psychedelics such as LSD and psilocybin (the main ingredient in most hallucinogenic mushrooms) are the subject of renewed research interest because of their therapeutic potential. They could ease a variety of difficult-to-treat mental illnesses, such as chronic depression, post-traumatic stress disorder, and alcohol dependency. In 2018, the United States Food and Drug Administration (FDA) granted breakthrough therapy designation for psilocybin-assisted therapy for treatment-resistant major depressive disorder. In 2019, the FDA also granted breakthrough therapy designation for psilocybin therapy treating major depressive disorder more generally. MDMA (Ecstasy) has been used for cognitive enhancement in people with Parkinson's disease, and has shown potential in treating posttraumatic stress disorder, social anxiety, and alcohol addiction.
Lack of access to controlled medications
Under prohibition, millions of people find it very difficult to obtain controlled medications, particularly opiate pain-relievers. The United Nations 1961 Single Convention on Narcotic Drugs requires that opiates be distributed only by medical prescription, but this is impractical in many areas.
According to the Transnational Institute, June 2008:
According to the International Narcotics Control Board (INCB) and the World Health Organisation (WHO) there is now an unmet demand in opiates. Ironically, the current drug control regulations hamper access to controlled opiate medications for therapeutic use. Many patients are unable to access morphine, methadone or an equivalent opioid. Global medical morphine consumption would rise five times if countries would make morphine available at the level of the calculated need, according to a recent WHO estimate.
According to the New York Times, September 2007:
Under Sierra Leone law, morphine may be handled only by a pharmacist or doctor, explained Gabriel Madiye, the hospice's founder. But in all Sierra Leone there are only about 100 doctors — one for every 54,000 people, compared with one for every 350 in the United States.... "How can they say there is no demand when they don't allow it?" he [Madiye] asked. "How can they be so sure that it will get out of control when they haven't even tried it?"
Economic
Economic arguments for prohibitive drug laws
The DEA argues that "compared to the social costs of drug abuse and addiction—whether in taxpayer dollars or in pain and suffering—government spending on drug control is minimal."
Antonio Maria Costa, executive director of the United Nations Office on Drugs and Crime, has said:
Gil Kerlikowske, former director of the US ONDCP, argues that legalizing drugs, then regulating and taxing their sale, would not be effective fiscally.
Former directors of the ONDCP, John P. Walters and Barry McCaffrey have accused billionaires George Soros, Peter Lewis and John Sperling of bankrolling the pro-pot or drug legalisation movement. "These people use ignorance and their overwhelming amount of money to influence the electorate", Walters said. Billionaire US financier, George Soros said in his autobiography, "I would establish a strictly controlled distribution network through which I would make most drugs, excluding the most dangerous ones like crack, legally available." The drug legalization lobby's vigorous and well funded promotion in media and schools of a "safe use of illegal drugs" message
indicates that drug prohibition is in the midst of a pitched battle waged by those who are accepting not only of the drug user but who also strongly promote an acceptance of drug use itself.
Prohibition of hemp industry
Opposition to the legalization of hemp, which uses plants of the cannabis genus for commercial purposes, centres on the fact that those wanting to legalize the use of cannabis for recreational and medical purposes themselves present it as their Trojan horse for that very purpose:
In a Huffington Post interview, Mark Kleiman, the "Pot Czar" of Washington state, said he was concerned that the National Cannabis Industry Association would favor profits over public health. He also said that it could become a predatory body like the lobbying arms of the tobacco and alcohol industries. Kleiman said: "The fact that the National Cannabis Industry Association has hired itself a K Street suit [lobbyist] is not a good sign."
Economic arguments for drug law reform
The United States efforts at drug prohibition started out with a $350 million budget in 1971, and was in 2006 a $30 billion campaign. These numbers only include direct prohibition enforcement expenditures, and as such only represent part of the total cost of prohibition. This $30 billion figure rises dramatically once other issues, such as the economic impact of holding 400,000 prisoners on prohibition violations, are factored in.
The war on drugs is extremely costly to such societies that outlaw drugs in terms of taxpayer money, lives, productivity, the inability of law enforcement to pursue mala in se crimes, and social inequality. Some proponents of decriminalization say that the financial and social costs of drug law enforcement far exceed the damages that the drugs themselves cause. For instance, in 1999, close to 60,000 prisoners (3.3% of the total incarcerated population) convicted of violating marijuana laws were behind bars at a cost to taxpayers of some $1.2 billion per year. In 1980, the total jail and prison population was 540,000, about one-quarter the size it is today. Drug offenders accounted for 6% of all prisoners. According to the Federal Bureau of Prisons, drug offenders now account for nearly 51%.
It has been argued that if the US government legalised marijuana it would save $7.7 billion per year in expenditure on enforcement of prohibition. Also, that marijuana legalization would yield tax revenue of $2.4 billion annually if it were taxed like all other goods and $6.2 billion annually if it were taxed at rates comparable to those on alcohol and tobacco.
According to a 2018 report, legalising cannabis in the United Kingdom could raise between 1 and 3.5 billion pounds in tax and lead to savings for the police and the criminal justice system. It has been argued that the raised tax revenue could then be invested in public services, such as the budget of the National Health Service (NHS).
The creation of drug cartels
Mass arrests of local growers of marijuana, for example, not only increase the price of local drugs, but lessens competition. Only major retailers that can handle massive shipments, have their own small fleet of aircraft, troops to defend the caravans and other sophisticated methods of eluding the police (such as lawyers), can survive by this regulation of the free market by the government
Effect on producer countries
The United States' "War on Drugs" has added considerably to the political instability in South America. The huge profits to be made from cocaine and other South American-grown drugs are largely because they are illegal in the wealthy neighbouring nation. This drives people in the relatively poor countries of Colombia, Peru, Bolivia and Brazil to break their own laws in organising the cultivation, preparation and trafficking of cocaine to the States. This has allowed criminal, paramilitary and guerrilla groups to reap huge profits, exacerbating already serious law-and-order and political problems. Within Bolivia, the political rise of former president Evo Morales was directly related to his grassroots movement against US-sponsored coca-eradication and criminalization policies. However, coca has been cultivated for centuries in the Andes. Among their various legitimate uses, coca leaves are chewed for their mild stimulant & appetite suppression effects, and steeped as a tea which is known to reduce the effects of human altitude sickness. Rural farmers in the poor regions in which coca has historically been cultivated often find themselves at the difficult and potentially violent intersection of government-sponsored eradication efforts, illegal cocaine producers & traffickers seeking coca supplies, anti-government paramilitary forces trafficking in cocaine as a source of revolutionary funding, and the historical hardships of rural subsistence farming (or its typical alternative – abandoning their land and fleeing to an urban slum). In some regions, farmers' coca and other crops are frequently destroyed by U.S.-sponsored eradication treatments (usually sprayed from the air with varying degrees of discrimination), whether or not the farmers directly supply the cocaine trade, thereby destroying their livelihoods. Agricultural producers in these countries are pushed further to grow coca for the cocaine trade by the dumping of subsidised farming products (fruit, vegetables, grain etc.) produced by Western countries (predominantly US and EU agricultural surpluses) (see BBC reference, below), which reduces the prices they could otherwise receive for alternate crops such as maize. The net effect can be a depression of prices for all crops, which can both make the farmer's livelihood more precarious, and make the cocaine producers' coca supplies cheaper.
After providing a significant portion of the world's poppy for use in heroin production, Afghanistan went from producing practically no illegal drugs in 2000 (following banning by the Taliban), to cultivating what is now as much as 90% of the world's opium. The Taliban is currently believed to be heavily supported by the opium trade there.
Furthermore, the sale of the illegal drugs produces an influx of dollars that is outside the formal economy, and puts pressure on the currency exchange keeping the dollar low and making the export of legal products more difficult.
Prohibition of hemp industry
The war on drugs has resulted in the outlawing of the entire hemp industry in the United States. Hemp, which is a special cultivar of Cannabis sativa, does not have significant amounts of psychoactive (THC) substances in it, less than 1%. Without even realizing the plant had been outlawed several months prior, Popular Mechanics magazine published an article in 1938 entitled "The New Billion-Dollar Crop" anticipating the explosion of the hemp industry with the invention of machines to help process it. Recently, governmental refusal to take advantage of taxing hemp has been a point of criticism. Hemp has a large list of potential industrial uses including textiles, paper, rope, fuel, construction materials, and biocomposites (for use in cars for example). Hemp has some drawbacks, however, one being that the long fibers in hemp are only a part of the outer bast, and this has contributed to hemp having only modest commercial success in countries (for example in Canada) where it is legal to harvest hemp.
The seed of the hemp plant is highly nutritious. Rare for a plant, it contains all essential amino acids. Rare for any food, it is a good source of alpha-linolenic acid, an omega 3 fatty acid which is deficient in most diets.
Legalization as a job creator
Drug legalization has the potential to create a vast array of jobs, in sectors such as: sales, distribution, transportation, growing, cultivation, production, quality assurance, regulatory bodies, advertising, scientific research and lab analysis. If certain drugs were to be sold solely at single-purpose licensed premises then construction of these stores would also help the construction industry.
A 2019 jobs count found that legalized cannabis had directly created 211,000 full-time workers in the U.S., part of a total of 296,000 in all related areas combined (as a total of states where cannabis is legal). Nick Colas at DataTrek Research said in 2019 that cannabis is the “fastest-growing labor market in the U.S.” If cannabis were to be legalized nationally across the U.S., it is estimated that it would create over one million jobs.
Before the legalization of cannabis in Canada, it was estimated that the legalization of cannabis in the country would create thousands of new jobs. However, comprehensive statistics regarding the total amount jobs created by legalized cannabis in Canada have yet to be published post legalization. Cannabis was legalized in Canada on 17 October 2018.
Crime, terrorism and social order
Arguments for prohibitive drug laws
While concerns are sometimes expressed that the "war on drugs" can never be won, there is a failure to recognize that other justifiably costly policing wars such as "blitzes" on speeding can likewise never be won. Such blitzes reduce and contain speeding, as with policing of illicit drug use. Failure to police speeding drivers simply allows inordinate harm to be inflicted on other individuals. Speeding is not legalized simply because it can never be eradicated.
There is an argument that much crime and terrorism is drug related or drug funded and that prohibition should reduce this.
Former US president George W. Bush, in signing the Drug-Free Communities Act Reauthorization Bill in December 2001, said, "If you quit drugs, you join the fight against terror in America."
The US Office of National Drug Control Policy (ONDCP) says that drug-related offences may include violent behavior resulting from drug effects.
The US Drug Enforcement Administration claims:
The U.S. government began the Drug Use Forecasting (DUF) program in 1987 to collect information on drug use among urban arrestees. In 1997, the National Institute of Justice expanded and reengineered the DUF study and renamed it the Arrestee Drug Abuse Monitoring (ADAM) program. ADAM is a network of 34 research sites in select U.S. cities.
DUF research indicates that:
Frequent use of hard drugs is one of the strongest indicators of a criminal career.
Offenders who use drugs are among the most serious and active criminals, engaging in both property and violent crime.
Early and persistent use of cocaine or heroin in the juvenile years is an indicator of serious, persistent criminal behavior in adulthood.
Those arrested who are drug users are more likely than those not using drugs to be rearrested on pretrial release or fail to appear at trial.
Criminal behavior can importantly be the direct result of drug use which can cause emotional/brain damage, mental illness and anti-social behavior. Psychoactive drugs can have a powerful impact on behavior which may influence some people to commit crimes that have nothing to do with supporting the cost of their drug use. The use of drugs changes behavior and causes criminal activity because people will do things they wouldn't do if they were rational and free of the drug's influence. Cocaine-related paranoia is an example. If drug use increases with legalization, so will such forms of related violent crime as assaults, drugged driving, child abuse, and domestic violence.
That higher prices make the trade lucrative for criminals is recognized but countered by the argument that capitulating to illicit drug use on these grounds makes no more sense than capitulating to those who continue to traffic in human lives, a more expensive business because of its illegality and therefore more lucrative for the criminal, but necessary for the rights of vulnerable citizens.
The Office of National Drug Control Policy says that the idea that our nation's prisons are overflowing with otherwise law-abiding people convicted for nothing more than simple possession of marijuana is a myth, "an illusion conjured and aggressively perpetuated by drug advocacy groups seeking to relax or abolish America's marijuana laws." ONDCP state that the vast majority of inmates in state and federal prison for marijuana have been found guilty of much more than simple possession. Some were convicted for drug trafficking, some for marijuana possession along with one or more other offenses. And many of those serving time for marijuana pleaded down to possession in order to avoid prosecution on much more serious charges. In the US, just 1.6 percent of the state inmate population were held for offences involving only marijuana, and less than one percent of all state prisoners (0.7 percent) were incarcerated with marijuana possession as the only charge. An even smaller fraction of state prisoners were first time offenders (0.3 percent). The numbers on the US federal prisons are similar. In 2001, the overwhelming majority of offenders sentenced for marijuana crimes were convicted for trafficking and only 63 served time for simple possession.
Detective superintendent Eva Brännmark from the Swedish National Police Board, in a speech given to Drug Free Australia's first international conference on illicit drug use, said:
The argument that drug addicts of certain drugs are forced into crime by prohibition should first and foremost highlight the fact that this argument presupposes and underlines the addictive nature of some illicit drugs (which legalization proponents often downplay), addictive enough to create a viable criminal supply industry. Secondly, the harms of increased addictive drug use, which as previously outlined would be a consequence of legalization and its cheaper prices, far outweigh the current crime harms of prohibition. It is worth pointing out, this argument is not useful for substances such as LSD and mescaline, with no addictive properties.
Although criminal punishments vary with rooting out drug usage, it is not the foremost eradication technique to resolve substance use disorder issues. In order to combat these issues, the application of treatment and support group resources coupled with community support and understanding, has far higher long-term potential to cure the ever-growing epidemic plaguing the nation, especially in rural areas.
Arguments for drug law reform
In 2021, Professor Peter Singer described the War on Drugs as an expensive, ineffective and extremely harmful policy.
Violence and profits of drugs traffickers
Prohibition protects the drug cartel insofar as it keeps the distribution in the black market and creates the risk that makes smuggling profitable. As former federal narcotics officer Michael Levine states in relation to his undercover work with Colombian cocaine cartels, from Lamar
"I learned that not only did they not fear our war on drugs, they counted on it to increase the market price and to weed out the smaller, inefficient drug dealers. They found U.S. interdiction efforts laughable. The only U.S. action they feared was an effective demand reduction program. On one undercover tape-recorded conversation, a top cartel chief, Jorge Roman, expressed his gratitude for the drug war, calling it "a sham put on for the American taxpayer" that was actually "good for business".
Critics of drug prohibition often cite the fact that the end of alcohol prohibition in 1933 led to immediate decreases in murders and robberies to support the argument that legalization of drugs could have similar effects. Once those involved in the narcotics trade have a legal method of settling business disputes, the number of murders and violent crime could drop. Robert W. Sweet, a federal judge, strongly agrees: "The present policy of trying to prohibit the use of drugs through the use of criminal law is a mistake". When alcohol use was outlawed during prohibition, it gave rise to gang warfare and spurred the formation of some of the most well known criminals of the era, among them the infamous Al Capone. Similarly, drug dealers today resolve their disputes through violence and intimidation, something which legal drug vendors do not do. Prohibition critics also point to the fact that police are more likely to be corrupted in a system where bribe money is so available. Police corruption due to drugs is widespread enough that one pro-legalization newsletter has made it a weekly feature.
Drug money has been called a major source of income for terrorist organizations. Critics assert that legalization would remove this central source of support for terrorism. While politicians blame drug users for being a major source of financing terrorists, no clear evidence of this link has been provided. US government agencies and government officials have been caught trafficking drugs to finance US-supported terrorist actions in events such as the Iran-Contra Affair, and Manuel Noriega but the isolated nature of these events precludes them from being major sources of financing.
Corruption
Human rights organizations and legal scholars have claimed that drug prohibition inevitably leads to police corruption.
On 2 July 2010, former Interpol President Jackie Selebi was found guilty of corruption by the South African High Court in Johannesburg for accepting bribes worth US$156,000 from a drug trafficker. After being charged in January 2008, Selebi resigned as president of Interpol and was put on extended leave as National Police Commissioner of South Africa.
Stigma of conviction
Despite the fact that most drug offenders are non-violent, the stigma attached to a conviction can prevent employment and education.
Since the human brain continues to mature past age eighteen and into a person's early twenties, it has been argued that many adult drug users will have made decisions to take drugs when their brains were not fully developed and thus they may not have adequately appreciated the risks (as many drug users are under the age of thirty). Since having a drug conviction will create societal disadvantages for the rest of a person's life, it has been argued that drug laws do not adequately take into account the full extent of human maturity when punishing people for taking drugs.
Children being lured into the illegal drug trade
Janet Crist of the White House Office of National Drug Control Policy mentioned that the anti-drug efforts have had "no direct effect on either the price or the availability of cocaine on our streets". Additionally, drug dealers show off expensive jewellery and clothing to young children. Some of these children are interested in making fast money instead of working legitimate jobs. Drug decriminalization would remove the "glamorous Al Capone-type traffickers who are role-models for the young".
The lack of government regulation and control over the lucrative illegal drug market has created a large population of unregulated drug dealers who lure many children into the illegal drug trade. The U.S. government's most recent 2009 National Survey on Drug Use and Health (NSDUH) reported that nationwide over 800,000 adolescents ages 12–17 sold illegal drugs during the previous 12 months preceding the survey. The 2005 Youth Risk Behavior Survey by the U.S. Centers for Disease Control and Prevention (CDC) reported that nationwide 25.4% of students had been offered, sold, or given an illegal drug by someone on school property. The prevalence of having been offered, sold, or given an illegal drug on school property ranged from 15.5% to 38.7% across state CDC surveys (median: 26.1%) and from 20.3% to 40.0% across local surveys (median: 29.4%).
Despite more than $7 billion spent annually towards arresting and prosecuting nearly 800,000 people across the country for marijuana offenses in 2005, the federally funded Monitoring the Future Survey reports about 85% of high school seniors find marijuana "easy to obtain." That figure has remained virtually unchanged since 1975, never dropping below 82.7% in three decades of national surveys.
Environmental
With respect to drug crop cultivation, eradication efforts in line with prohibitionist drug policies ultimately force coca, poppy, and marijuana growers into more remote, ecologically sensitive areas. These crops, which are generally grown away from urban centers and state presence, tend to deplete forestland and expand the agricultural frontier. Out of fear of eradication, cultivators are incentivized to accelerate production cycles in order to obtain the highest yield in the shortest period of time; the pace and methods used by growers neglect measures to promote sustainability, exacerbating the environmental impact. Drug cultivators typically opt to produce in areas with ecosystems with abundant plant biomass to better conceal their operations. Ultimately, this practice leads to increased deforestation which contributes to a greater influx of greenhouse gases into the atmosphere. Moreover, the aerial spraying of herbicides such as glyphosate used in eradication and control efforts have been shown to have negative effects on environmental and human health.
The "balloon effect" also operates further up the drug commodity chain in countries where drugs are trafficked rather than cultivated. Like eradication programs, interdiction pushes traffickers into remote areas where they exacerbate preexisting pressures on forestland. Traffickers use slash and burn practices to convert forest into arable land for cash crop production for the purposes of money laundering as well as the construction of clandestine roads and airstrips. The war on drugs and prohibitionist policies only serve to aggravate the already detrimental impacts of narco-trafficking on Central American forests. Intensified ecological devastation across cultivation and trafficking zones is yet another negative unintended consequence of emphasis on supply-side narcotic reduction borne by poor countries.
User cost of drugs
When the cost of drugs increases, drug users are more likely to commit crimes in order to obtain money to buy the expensive drugs. Legalizing drugs would make drugs reasonably cheap.
Discriminatory
Arguments for inconsistent drug laws
In response to the issue of consistency with regard to drug prohibition and the dangers of alcohol former director of the ONDCP John P. Walters, has said, "It's ludicrous to say we have a great deal of problems from the use of alcohol so we should multiply that with marijuana".
Arguments against inconsistent drug laws
Since alcohol prohibition ended and the war on drugs began there has been much debate over the issue of consistency among legislators with regard to drug prohibition. Many anti-prohibition activists focus on the well-documented dangers of alcohol (such as alcoholism, cystitis, domestic violence, brain and liver damage). In addition to anecdotal evidence, they cite statistics to show more deaths caused by drunk driving under the influence of alcohol than by drivers under the influence of marijuana, and research which suggests that alcohol is more harmful than all but the most "dangerous" drugs. When the level of harm associated with the other drugs includes harm that arises solely as a result of the drugs illegality rather than merely that danger which is associated with actually using the drugs, only heroin, cocaine, barbiturates and street methadone were shown to be more harmful than the legal drug alcohol.
A 2002 DAWN report, for the USA records two possible drug-induced deaths where marijuana was the only drug found. Legal drugs however, have been the cause of more than half a million deaths a year: 480,000 from tobacco smoking-related illnesses and 80,000 from alcohol use disorder. Together, tobacco and alcohol cause about 20% of all yearly deaths in the USA.
It is argued that inconsistency between the harm caused and the legal status of these common drugs undermines the declared motives of the law enforcement agencies to reduce harm by prohibition, for example of marijuana.
In February 2009, the UK government was accused by its most senior expert drugs adviser Professor David Nutt of making political decisions with regard to drug classification, for example in rejecting the scientific advice to downgrade ecstasy from a class A drug. The Advisory Council on the Misuse of Drugs (ACMD) report on ecstasy, based on a 12-month study of 4,000 academic papers, concluded that it is nowhere near as dangerous as other class A drugs such as heroin and crack cocaine, and should be downgraded to class B. The advice was not followed. Jacqui Smith, then Home Secretary, was also widely criticised by the scientific community for bullying Professor David Nutt into apologising for his comments that, in the course of a normal year, more people died from falling off horses than died from taking ecstasy. Professor Nutt was later sacked by Jacqui Smith's successor as Home Secretary Alan Johnson; Johnson saying "It is important that the government's messages on drugs are clear and as an advisor you do nothing to undermine public understanding of them. I cannot have public confusion between scientific advice and policy and have therefore lost confidence in your ability to advise me as Chair of the ACMD."
Consistency between drugs
In the United States, defendants convicted of selling crack cocaine receive equal sentences to those convicted of selling 100 times the same amount of powder cocaine. This disparity was lessened during the Obama administration when the Fair Sentencing Act 2010 changed the ratio to 18 to 1. The majority of offenders convicted for selling crack are poor and/or black, while the majority of those convicted for selling cocaine are not.
Same policy for distinct drugs
Many drug policies group all illegal drugs into a single category. Since drugs drastically vary in their effects, addictive potential, dosages, methods of production, and consumption the arguments either way could be seen as inconsistent.
Race and enforcement of drug laws
It has been alleged that current drug laws are enforced in such a way as to penalize non-whites more harshly and more often than whites, and to penalize the poor of all races more harshly and more often than the middle and upper classes. For example, up until 2012, crack cocaine carried penalties one hundred times more severe than cocaine despite the fact that these drugs are essentially identical. Especially in urban black communities, convictions were nearly exclusively for crack, while cocaine use is statistically much higher among affluent whites.
Civil rights
Civil rights arguments for prohibitive drug laws
Article 33 of the United Nations Convention on the Rights of the Child reads:
States Parties shall take all appropriate measures, including legislative, administrative, social and educational measures, to protect children from the illicit use of narcotic drugs and psychotropic substances as defined in the relevant international treaties and to prevent the use of children in the illicit production and trafficking of such substances.
Drug Free Australia argues:
The notion that illicit drug use is a victimless crime and that everyone should be free to do what they want with their body disregards the web of social interactions that constitute human existence. Affected by an individual's illicit drug use are children, parents, grandparents, friends, colleagues, work, victims of drugged drivers, crime victims, elder abuse, sexual victims etc. Illicit drug use is no less victimless than alcoholism.
Drug Free Australia gives the example that in 2007 one in every nine children under the age of 18 in the United States lived with at least one drug dependent or drug abusing parent. 2.1 million children in the United States live with at least one parent who was dependent on or used illicit drugs.
The Christian Institute argues that there is no point in having criminal laws unless those caught breaking them will at least face prosecution. Less serious offenses, such as failing to complete a census form, may also attract a criminal record, so the contention that criminalizing drug use is draconian can be seen as overstatement.
"Parental substance dependence and abuse can have profound effects on children, including child abuse and neglect, injuries and deaths related to motor vehicle accidents, and increased odds that the children will become substance dependent or abusers themselves. Up-to-date estimates of the number of children living with substance-dependent or substance-abusing parents are needed for planning both adult treatment and prevention efforts and programs that support and protect affected children."
Drug Free Australia concludes any democratic society that deems the use of a certain drug to present unacceptable harm to the individual user, to present unacceptable harm to the users' surrounding community or to transfer too great a burden to the community will seek legislation which will curb that particular freedom of the individual.
Sweden's centre-right alliance government Moderate Party advocates "Zero tolerance for crime", arguing:
Many people argue that only drug dealers should be fought and not the drug users themselves. But this rests on the fundamental error that big-time drugs smugglers and dealers hawk illicit drugs to new consumers. This is most often not the case. Rather it is the users themselves that are mostly responsible for recruiting new users through networks of friends or relatives demonstrating that users need to be targeted as the recruiters of new drug use, and that an emphasis on early rehabilitation for young users is the best answer to curbing widespread dealing. Sweden's mandatory rehabilitation program has resulted in the lowest drug use levels in the developed world.
The freedom of choice of those addicted to a drug is also questioned, recognizing that addiction is defined as compulsive by its very nature and that addictions in and of themselves curb individual freedom. Likewise, the proposal that addictive drugs should be legalized, regulated and opened to "free market dynamics" is immediately belied by the recognition that the drug market for an addict is no longer a free market – it is clear that they will pay any price when needing their drug.
Civil rights arguments for drug law reform
Cognitive liberty
Authors such as Aldous Huxley and Terence McKenna believed that what persons do in private should not be regulated by the government. It is argued that persons should be able to do whatever they want with their bodies, including the recreational use of drugs, as long as they do not harm others. Such arguments often cite the harm principle of philosopher John Stuart Mill who urged that the state had no right to intervene to prevent individuals from doing something that harmed them, if no harm was thereby done to the rest of society: 'Over himself, over his own body and mind, the individual is sovereign' and 'The only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not sufficient warrant.' The argument is that drug use is a victimless crime and as such the government has no right to prohibit it or punish drug consumers, much like the government does not forbid overeating, which causes significantly more deaths per year. This can be equated with the quest for freedom of thought.
Spiritual and religious
Some religious groups including the União do Vegetal, the Native American Church, the Bwiti religion and the Rastafari movement (see religious and spiritual use of cannabis) use psychoactive substances as sacrament in religious rituals. In some religious practice, drugs are sometimes used as a conduit to an oceanic feeling or divine union, equated with mysticism or entheogenic ('that which causes God to be within an individual') experiences. In others, the 'entactogenic' qualities of drugs are used to enhance feelings of empathy among congregations.
Personal development and exploration
Some people believe that altered states of consciousness enable many people to push the boundaries of human experience, knowledge, and creativity. There is thus a moral imperative to use drugs in terms of human progress, teleological development, or just increased artistic creativity; such ideas are central to Cognitive Liberty, Stoned Ape Hypothesis and Aldous Huxley's The Doors of Perception.
In PiHKAL, Alexander Shulgin, argues that the psychedelics help us learn about ourselves; indeed that is where the name "psychedelic" (mind expanding) comes from.
Moral and ethical reasons
Moral arguments for prohibitive drug laws
Moral arguments for drug law reform
Many people, including some religious groups, argue that the war on drugs is itself immoral.
In 2007, Richard Brunstrom, the Chief Constable of North Wales, one of Britain's most senior police officers, said "If policy on drugs is in future to be pragmatic not moralistic, driven by ethics not dogma, then the current prohibitionist stance will have to be swept away as both unworkable and immoral, to be replaced with an evidence-based unified system (specifically including tobacco and alcohol) aimed at minimisation of harms to society."
The author and physician Andrew Weil has commented on the peculiar attitude and emotional bias of some people who think "drug taking is bad", but who nevertheless consume alcohol, and formulate the unhelpful conception "We drink. Therefore alcohol is not a drug."
The UK drug policy reform group Release believe that the stigma attached to drug use needs to be removed. Release's actions have included challenging such stigmatisation with its "Nice People Take Drugs" advertising campaign.
Political
Sending out signals
Arguments for sending out signals
Some argue that sending out signals should be a consideration of drug policy. Previous UK Home Office Minister Vernon Coaker argued "is not part of any system with respect to drugs ... not only trying to send messages out to people who misuse drugs but also about trying to send messages out to people out there in the community?"
In response to the UK government's official drugs advisory body's opposition to cannabis reclassification (upwards, from a class C to a class B drug) in 2008, prime minister Gordon Brown said: "I believe that if we're sending out a signal, particularly to teenagers – and particular those at the most vulnerable age, young teenagers – that in any way we find cannabis acceptable, given all we know about the way that cannabis is being sold in this country, that is not the right thing to do. There's a stronger case now for sending out a signal that cannabis is not only illegal, it's unacceptable."
Arguments against sending out signals
The Science and Technology Select Committee appointed by the House of Commons to inquire into the Government's handling of scientific advice, risk and evidence in policy making agreed with Transform Drug Policy Foundation's view that "Criminal law is supposed to prevent crime, not 'send out' public health messages". Transform warned that sending out signals could backfire by "fostering distrust of police and public health messages amongst young people". The Select Committee's report said "The Government's desire to use the Class of a particular drug to send out a signal to potential users or dealers does not sit comfortably with the claim that the primary objective of the classification system is to categorise drugs according to the comparative harm associated with their misuse. It is also incompatible with the Government's stated commitment to evidence based policy making since it has never undertaken research to establish the relationship between the Class of a drug and the signal sent out and there is, therefore, no evidence base on which to draw in making these policy decisions."
Political calculation
Arguments for political calculation
John Donnelly, writing for the Boston Globe on the presidential race of 2000, suggested that the candidates' silence on drug policy may stem from a widely shared belief that any position even hinting at reducing penalties for drug use would be political suicide. Charles R. Schuster, director of the National Institute on Drug Abuse under Presidents Reagan and Bush (Snr.), was reported as saying in 1997, "Talking sense about drug policy in today's climate of opinion can be political suicide."
Drug policy academic Mark A.R. Kleiman has argued:
Scott Morgan reports how he once attended a discussion of Peter Reuter and David Boyum's book An Analytic Assessment of U.S. Drug Policy, in which the authors admitted ignoring the legalization option in their analysis. Boyum claimed that there was no legitimate political support for ending the drug war and that he and Reuter had therefore confined themselves to recommendations that they thought were politically viable.
Arguments against political calculation
The deaths of two teenage boys in the United Kingdom in March 2010 sparked a nationwide controversy over the amphetamine drug mephedrone, which had gained popularity as a legal high. The Advisory Council on the Misuse of Drugs (ACMD) recommended a ban on the drug, which was quickly passed into law, but the decision was criticised for being politically rather than scientifically driven and led to the resignation of the ACMD's Eric Carlin, the eighth member of the council to leave in five months in protest at what was seen as political interference. Toxicology reports released in May revealed that the boys had never taken the drug. In a later commentary, David Nutt noted that the pharmacology of mephedrone was not known at the time it was banned, and that the decision was so knee-jerk that the ACMD accidentally banned the wrong enantiomer for about a year.
Professor Colin Blakemore, professor of neuroscience at the University of Oxford, said: "This shocking news should be a salutary lesson to tabloid journalists and prejudiced politicians who held a gun to the heads of the ACMD and demanded that this drug should be banned before a single autopsy had been completed ... The politicians talk about using drug classification as a way of sending 'messages' to young people. I fear that the only message that will be sent by the hasty decision on mephedrone is that the drug laws deserve no respect."
Professor David Nutt, the former chairman of the ACMD, said: "the previous government's rush to ban mephedrone never had any serious scientific credibility – it looks much more like a decision based on a short-term electoral calculation. This news demonstrates why it's so important to base drug classification on the evidence, not fear, and why the police, media and politicians should only make public pronouncements once the facts are clear."
Public opinion
Public opinion on prohibitive drug laws
A direct example of societal attitudes driving the International Drug Conventions is the 1925 speech by the Egyptian delegate M. El Guindy to the 1925 Geneva Convention forum which prohibited cannabis – largely reproduced in Willoughby, W. W.; In the late 19th and early 20th century drug use was regarded by the public "as alone a habit, vice, sign of weakness or dissipation", similar to the view of those who could not control their use of the licit drug alcohol. The use of illicit drugs has been prohibited internationally since 1912, an entire century, because of international agreement that the general community has a greater right to protect itself from the harms of illicit drug use than does an individual user to use a harmful substance recreationally.
Currently there is still greater public support for the continued prohibiting of illicit drug use than there is for legalizing and regulating the use of these substances. In the United States 82% of those polled by the Family Research Association in 1998 were opposed to the legalization of heroin and cocaine in the same manner as alcohol is legal. In October 2009 a Gallup poll found that 54% of those polled were against the legalization of cannabis. In Australia, which has had the highest levels of illicit drug use in Organisation for Economic Co-operation and Development (or OECD) countries for more than a decade, according to a 2007 survey, 95% of Australians do not support the legalization of heroin, cocaine and amphetamines, and 79% do not support the legalization of cannabis.
It can be argued that the negative attitudes to illicit drug use which issued in the international drug Conventions, with prohibitions against their use 100 years ago, still exist today. Taking again statistics from Australia, 97% disapprove of the regular use of heroin, 96% disapprove the regular use of amphetamines or cocaine, and 76.5% disapprove of the regular use of cannabis. In any democracy where "the will of the people" is respected by its political representatives, the prohibition of these substance might well be expected to remain intact.
Public opinion on drug law reform
According to Transform Drug Policy Foundation, over the past decade there has been strong shift in public opinion in favour of drug policy reform. This shift has taken place despite successive government's reluctance to consider or debate the subject, or even call to for an independent inquiry.
A national telephone survey conducted in 1993 found that between 52% and 55% of Australians believed that growing and possessing cannabis for personal use should be legalised.
An ICM poll of 1201 people for The Guardian in 1998 found that 47% believed that the illegality of drugs actually encourages young people to try them.
46% of UK adults in a 2002 Guardian poll (of 1075) felt that drug addicts who register themselves as such should have access to certain illegal drugs via prescription.
An ICM poll of 1008 UK adults (aged 16+) for The Guardian in 2008 found that 38% would support a scheme, similar to that established in Portugal and Spain, whereby it is not a criminal offence to possess and use drugs privately.
Following President Barack Obama's win of the 2008 presidential election, Change.gov hosted a service on their website named the Citizen's Briefing Book allowing United States citizens to give their opinion on the most important issues in America, and allow others to vote up or down on those ideas. The top ten ideas are to be given to Obama on the day of his inauguration, January 20, 2009. The most popular idea according to respondents was "Ending Marijuana Prohibition", earning 92,970 points and obtaining a total of 3,550 comments.
The second most popular hope, by contrast, was "Commit to becoming the "Greenest" country in the world." with 70,470 points.
Marijuana has seen a renaissance in its utopian representation in films such as the suburban satire American Beauty (1999, dir. Sam Mendes) and the stoner comedy Pineapple Express (2008, dir. David Gordon Green). Another venue for contemporary criticism of marijuana prohibition is television, such as the Showtime series Weeds (2005–2012, dev. Jenji Kohan); the HBO series True Blood (2008–2014, dev. Alan Ball); and adult animation shows such as South Park, Family Guy, and American Dad!.
David Simon, creator of the television series The Wire, in 2011 told U.S. Attorney General Eric Holder that he'd "give him another season of the HBO show for an end to the war on drugs." Holder had invited show stars Wendell Pierce, Sonja Sohn, and Jim True-Frost to Washington on behalf of an anti-drug public relations campaign and at the time called on Simon and Ed Burns for another season or a movie of the show. Simon replied via a letter to a newspaper offering the trade.
In November 2020, 76 percent of voters in Washington D.C. voted in favor of the initiative to decriminalize psychedelic plants and fungi.
See also
Altered state of consciousness
Chasing the Scream
Cognitive liberty
Darknet market
Demand reduction
Dagga Couple
Drug addiction
Drug Policy Alliance
Drug policy of Sweden
Drug policy of the Netherlands
Drug policy of Portugal
Drug possession
FAAAT think & do tank
Freedom of thought
Harm reduction
Illegal drug trade
Law Enforcement Against Prohibition
NORML, National Organization to Reform Marijuana Laws.
Neurotheology
Perverse incentive
Prohibition (drugs)
Recreational drug use
The Rhetoric of Drugs
Think of the children
Transform Drug Policy Foundation
War on drugs
Zero tolerance
Notes
References
Further reading
"The Mission to End Prohibition." Making Contact. National Radio Project, Oakland CA: 4 November 2009
Toward a Policy on Drugs: Decriminalization? Legalization? Currie, Elliot. Dissent. 1993. Rpt. in Drug Use Should Be Decriminalized. At Issue: Legalizing Drugs. Karin L. Swisher, ed., San Diego, CA.: Greenhaven Press, Inc., 1996: 55–64.
Rolles S. Kushlick D. Jay M. 2004 After the War on Drugs, Options for Control Transform Drug Policy Foundation
Legalization Madness. Inciardi, James A. and Christine A. Saum. Public Interest 123 (1996): 72–82. Rpt. in Legalizing Drugs Would Increase Violent Crime. Current Controversies: Illegal Drugs. Charles P. Cozic, ed., San Diego, CA.: Greenhaven Press, Inc., 1998: 142–150.
Poll Shows Most Russians Against Legalization of Soft Drugs. ITAR-TASS. BBC Monitoring 26 June 2003. Newsbank. 1 Feb 2004.
Jaffer, Mehru, U.N. Firm Against Legalization of Drugs. Inter Press Service 17 Apr. 2003. Newsbank. 1 Feb. 2004 .
Lavoie, Dusty, Marijuanatopia? – Placing Pot Media in the U.S. Social Imaginary: Surveillance, Consumption & Pleasure. ProQuest Dissertations, University of Maine, 2011.
Luna, Claire. Orange County Judge Gray, a Drug-War Foe, Will Run for Senate Now a Libertarian, the Longtime Advocate of Legalization Will Challenge Boxer in 2004. Los Angeles Times 20 Nov. 2003: B3. Newsbank. 1 Feb. 2004 .
Lynch, Gerald W. Legalizing Drugs Is Not the Solution. America 13 Feb. 1993. Rpt. in Legalizing Drugs Would Not Reduce Crime. At Issue: Legalizing Drugs. Karin L. Swisher, ed., San Diego, CA.: Greenhaven Press, Inc., 1996: 110–113.
McNeely, Jennifer. Methadone Maintenance Treatment. Lindesmith Center 1997. Rpt. in Methadone Is an Effective Treatment for Heroin Addiction. Current Controversies: Illegal Drugs. Charles P. Cozic, ed., San Diego, CA.: Greenhaven Press, Inc., 1998: 91–95.
McWilliams, Peter. Ain't Nobody's Business If You Do. Los Angeles, CA. : Prelude Press, 1996 (full text)
Mendez, Julia de Cruz and Ralf Winkler. Marihuana Tax Act of 1937. Jan. 1996. 24 Mar. 2004 .
Paulin, Alastair. Taxation Without Legalization. Mother Jones June 2003: 26. Newsbank. 1 Feb. 2004 .
Rodriguez, L. Jacabo. Time to End the Drug War. CATO Institute 13 Dec. 1997. 23 Feb. 2004 .
Should We Re-Legalize Drugs? United States Libertarian Party. 22 Feb. 2004 .
Thornton, Mark. Alcohol Prohibition Was a Failure. CATO Institute 17 July 1991. 24 Mar. 2004 .
Zuckerman, Mortimer B. Great Idea for Ruining Kids. U.S. News & World Report 24 Feb. 1997. Rpt. in Legalizing Drugs Would Increase Drug Use. Current Controversies: Illegal Drugs. Charles P. Cozic, ed., San Diego, CA.: Greenhaven Press, Inc., 1998: 151–152.
Leavitt, Fred. (2003) The REAL Drug Abusers. Rowman & Littlefield.
Armentano, Paul. Drug War Mythology in You Are Being Lied To. China: The Disinformation Company Ltd., 2001. pp. 234–240
Goldstein, P.J., Brownstein, H.H., Ryan, P.J. & Bellucci, P.A., Crack and Homicide in New York City: A Case Study in the Epidemiology of Violence, in Reinarman, C. and Levine, H. (eds.), Crack in America: Demon Drugs and Social Justice (Berkeley, CA: University of California Press, 1997), pp. 113–130.
Skorneck, Carolyn (Feb 1990). "Survey: 61 percent say all drugs immoral". Moscow-Pullman Daily News.
External links
Why It's Time to Legalize Drugs. Published by HuffPost on 23 February 2016. Last updated on 23 February 2017. Author - Kofi Annan (Secretary-General of the United Nations from January 1997 to December 2006).
"After the War on Drugs: Blueprint for Regulation", 1 July 2009
The Mission to End Prohibition, Making Contact. 4 Nov 2009.
EMCDDA—Decriminalisation in Europe? Recent developments in legal approaches to drug use.
The case for legalisation, The Economist, Jul. 26 2001.
The Senlis Council, international think tank on drug policy reform.
European coalition for Just and effective drugs policies
Cannabis. American Heritage Dictionary of the English Language. Fourth Edition. 2000. Rpt. in Dictionary.com 25 Mar 2004
War on Drugs. Mary H. Cooper. Congressional Quarterly 13 Mar. 1993: 243–258. SIRS. 1 Feb. 2004.
An interview with pro-legalization Nobel laureate economist Milton Friedman
The Drug War as a Socialist Enterprise by Milton Friedman
Simpson, John, 'Rethinking the war on drugs', BBC News, 7 October 2005.
Marijuana 'top cash crop in US', BBC News, 19 December 2006.
Civil rights and liberties
Political controversies
Drug culture | Arguments for and against drug prohibition | Chemistry | 15,169 |
33,770,704 | https://en.wikipedia.org/wiki/Data%20processing%20unit | A data processing unit (DPU) is a programmable computer processor that tightly integrates a general-purpose CPU with network interface hardware. Sometimes they are called "IPUs" (for "infrastructure processing unit") or "SmartNICs". They can be used in place of traditional NICs to relieve the main CPU of complex networking responsibilities and other "infrastructural" duties; although their features vary, they may be used to perform encryption/decryption, serve as a firewall, handle TCP/IP, process HTTP requests, or even function as a hypervisor or storage controller. These devices can be attractive to cloud computing providers whose servers might otherwise spend a significant amount of CPU time on these tasks, cutting into the cycles they can provide to guests.
Examples of DPUs
Azure Boost DPU
In 2024, Microsoft introduced the Azure Boost DPU, a custom-designed data processing unit aimed at optimizing network and infrastructure efficiency across its Azure cloud platform. This DPU offloads network-related tasks such as packet processing, security enforcement, and traffic management from central CPUs, enabling better performance for application workloads.
Key Features
Network Optimization: The Azure Boost DPU enhances network throughput and reduces latency by processing data packets and offloading these tasks from traditional CPUs.
Security Capabilities: It integrates advanced isolation techniques to secure multi-tenant environments, protecting sensitive workloads.
Hyperscale Adaptability: Designed for large-scale data centers, the DPU supports Azure’s hyperscale infrastructure, ensuring scalability for modern cloud applications.
Industry Context
The Azure Boost DPU aligns with the trend of custom silicon development in hyperscale cloud environments. Similar to AWS’s Nitro System and NVIDIA’s BlueField DPUs, Microsoft’s DPU focuses on enhancing cloud efficiency while addressing rising energy and security demands. This innovation positions Microsoft alongside other cloud leaders leveraging DPUs to optimize data center operations and provide cost-effective, high-performance solutions for customers.
Impact on Cloud Computing
The introduction of DPUs like Azure Boost reflects a broader shift in the cloud computing industry toward offloading specific functions from general-purpose processors to specialized hardware. Microsoft’s Azure Boost DPU represents its strategy to reduce costs, enhance security, and achieve sustainability goals while improving infrastructure efficiency.
See also
Compute Express Link (CXL)
References
Electronics
Data processing
Artificial intelligence engineering
Application-specific integrated circuits
Hardware acceleration
Digital electronics
Electronic design
Electronic design automation | Data processing unit | Technology,Engineering | 514 |
62,410,103 | https://en.wikipedia.org/wiki/Carbonate%20chloride | The carbonate chlorides are double salts containing both carbonate and chloride anions. Quite a few minerals are known. Several artificial compounds have been made. Some complexes have both carbonate and chloride ligands. They are part of the family of . In turn these are a part of mixed anion materials.
The carbonate chlorides do not have a bond from chlorine to carbon, however "chlorocarbonate" has also been used to refer to the chloroformates which contain the group ClC(O)O-.
Formation
Natural
Scapolite is produced in nature by metasomatism, where hot high pressure water solutions of carbon dioxide and sodium chloride modify plagioclase.
Chloroartinite is found in Sorel cements exposed to air.
Minerals
In 2016 27 chloride containing carbonate minerals were known.
Artificial
Complexes
The "lanthaballs" are lanthanoid atom clusters held together by carbonate and other ligands. They can form chlorides. Examples are [La13(ccnm)6(CO3)14(H2O)6(phen)18] Cl3(CO3)·25H2O where ccnm is carbamoylcyanonitrosomethanide and phen is 1,10-phenanthroline. Praseodymium (Pr) or cerium (Ce) can substitute for lanthanum (La). Other lanthanide cluster compounds include :(H3O)6[Dy76O10(OH)138(OAc)20(L)44(H2O)34]•2CO3•4
Cl2•L•2OAc (nicknamed Dy76) and (H3O)6[Dy48O6(OH)84(OAc)4(L)15(hmp)18(H2O)20]•CO3•14Cl•2H2O (termed Dy48-T) with OAc=acetate, and L=3-furancarboxylate and Hhmp=2,2-bis(hydroxymethyl)propionic acid.
Platinum can form complexes with carbonate and chloride ligands, in addition to an amino acid. Examples include the platinum compound [Pt(gluH)Cl(CO3)]2.2H2O gluH=glutamic acid, and Na[Pt(gln)Cl2(CO3)].H2O gln=glutamine. Rhodium complexes include Rh2(bipy)2(CO3)2Cl (bipy=bipyridine)
References
Carbonates
Chlorides
Mixed anion compounds
Double salts | Carbonate chloride | Physics,Chemistry | 571 |
2,951,953 | https://en.wikipedia.org/wiki/Argo%20%28ROV%29 | Argo is an unmanned deep-towed undersea video camera sled developed by Dr. Robert Ballard through Woods Hole Oceanographic Institute's Deep Submergence Laboratory. Argo is most famous for its role in the discovery of the wreck of the RMS Titanic in 1985. Argo would also play the key role in Ballard's discovery of the wreck of the battleship Bismarck in 1989.
The towed sled, capable of operating depths of 6,000 meters (20,000 feet), meant 98% of the ocean floor was within reach. The original Argo, used to find Titanic, was long, tall, and wide and weighed about in air. It had an array of cameras looking forward and down, as well as strobes and incandescent lighting to illuminate the ocean floor. It could acquire wide-angle film and television pictures while flying above the sea floor, towed from a surface vessel, and could also zoom in for detailed views.
See also
Acoustically Navigated Geological Underwater Survey (ANGUS)
References
Oceanographic instrumentation
Unmanned underwater vehicles | Argo (ROV) | Technology,Engineering | 216 |
32,257,915 | https://en.wikipedia.org/wiki/ULAS%20J1120%2B0641 | ULAS J1120+0641 was the most distant known quasar when discovered in 2011, surpassed in 2017 by ULAS J1342+0928. ULAS J1120+0641 (at projected comoving distance of 28.85 billion light-years) was the first quasar discovered beyond a redshift of z = 7. Its discovery was reported in June 2011.
Discovery
ULAS J1120+0641 was discovered by the UKIRT Infrared Deep Sky Survey (UKIDSS), using the UK Infrared Telescope, located in Hawaii. The name of the object is derived from UKIDSS Large Area Survey (ULAS), the name of the survey that discovered the quasar, and the location of the quasar in the sky in terms of right ascension (11h 20m) and declination (+06° 41'). This places the quasar in the constellation of Leo, close (on the plane of the sky) to σ Leo. The quasar was discovered by a telescope that operates at infrared wavelengths, which is at longer wavelength and lower energy than visible light. When the light was originally emitted by ULAS J1120+0641, it was in the ultraviolet, with shorter wavelength and higher energy than visible light. The change in energy and wavelength of the light is due to the expanding universe, which imparts a cosmological redshift to all light as it travels through the universe.
The team of scientists spent years searching the UKIDSS for a quasar whose redshift was higher than 6.5. ULAS J1120+0641 is even farther away than they hoped for, with a redshift greater than 7.
UKIDSS is a near infrared photometric survey, so the original discovery was only a photometric redshift of . Before announcing their discovery, the team used spectroscopy on the Gemini North Telescope and the Very Large Telescope to obtain a spectroscopic redshift of .
Description
ULAS J1120+0641 has a measured redshift of 7.085, which corresponds to a comoving distance of 28.85 billion light-years from Earth. , it is the most distant quasar yet observed. The quasar emitted the light observed on Earth today less than 770 million years after the Big Bang, about 13 billion years ago. This is 100 million years earlier than light from the most distant previously known quasar.
The quasar's luminosity is estimated at solar luminosities. This energy output is generated by a supermassive black hole estimated at solar masses. While the black hole powers the quasar, the light does not come from the black hole itself. Daniel Mortlock, lead author of the paper that announced the discovery of ULAS J1120+0641, explained, "The super-massive black hole itself is dark but it has a disc of gas or dust around it that has become so hot that it will outshine an entire galaxy of stars."
Significance
The light from ULAS J1120+0641 was emitted before the end of the theoretically-predicted transition of the intergalactic medium from an electrically neutral to an ionized state (the epoch of reionization). Quasars may have been an important energy source in this process, which marked the end of the cosmic Dark Ages, so observing a quasar from before the transition is of major interest to theoreticians. Because of their high ultraviolet luminosity, quasars also are some of the best sources for studying the reionization process.
This is the first time scientists have seen a quasar with such a large fraction of neutral (non-ionized) hydrogen absorption in its spectrum. Mortlock estimates that 10% to 50% of the hydrogen at the redshift of ULAS J1120+0641 is neutral. The neutral hydrogen fraction in all other quasars seen, even those only 100 million years younger, was typically 1% or less. The spectrum also lacked any significant indication of non-BBN metals. The combination of the neutral hydrogen reading, and lack of metals is suggestive of the quasar being embedded in a protogalaxy in the midst of forming, and possibly creating the first Population III stars for the galaxy, or a pre-protogalaxy core still embedded in the primordial hydrogen fog, predating the Population III stellar population for this galaxy.
The supermassive black hole in ULAS J1120+0641 has a higher mass than was expected. The Eddington limit sets a maximum rate at which a black hole can grow, so the existence of such a massive black hole so soon after the Big Bang implies that it must have formed with a very high initial mass, through the merging of thousands of smaller black holes, or that the standard model of cosmology requires revision.
See also
List of most distant astronomical objects
List of quasars
J0313–1806 − most distant quasar (z=7.64)
Notes
References
External links
ESO, "The most distant quasar" (Image)
PhysOrg, "Astronomers find universe's most distant quasar (w/ video)"
20110630
Leo (constellation)
Quasars | ULAS J1120+0641 | Astronomy | 1,094 |
12,887,799 | https://en.wikipedia.org/wiki/Biological%20pacemaker | A biological pacemaker is one or more types of cellular components that, when "implanted or injected into certain regions of the heart," produce specific electrical stimuli that mimic that of the body's natural pacemaker cells. Biological pacemakers are indicated for issues such as heart block, slow heart rate, and asynchronous heart ventricle contractions.
The biological pacemaker is intended as an alternative to the artificial cardiac pacemaker that has been in human use since the late 1950s. Despite their success, several limitations and problems with artificial pacemakers have emerged during the past decades such as electrode fracture or damage to insulation, infection, re-operations for battery exchange, and venous thrombosis. The need for an alternative is most obvious in children, including premature newborn babies, where size mismatch and the fact that pacemaker leads do not grow with children are a problem. A more biological approach has been taken in order to mitigate many of these issues. However, the implanted biological pacemaker cells still typically need to be supplemented with an artificial pacemaker while the cells form the necessary electrical connections with cardiac tissue.
History
The first successful experiment with biological pacemakers was carried out by Arjang Ruhparwar 's group at Hannover Medical School in Germany using transplanted fetal heart muscle cells. The process was first introduced at the scientific sessions of the American Heart Association in Anaheim in 2001, and the results were published in 2002. A few months later, Eduardo Marban's group from Johns Hopkins University published the first successful gene-therapeutic approach towards the generation of pacemaking activity in otherwise non-pacemaking adult cardiomyocytes using a guinea pig model. The investigators postulated latent pacemaker capability in normal heart muscle cells. This potential ability is suppressed by the inward-rectifier potassium current Ik1 encoded by the gene Kir2 which is not expressed in pacemaker cells. By specific inhibition of Ik1 below a certain level, spontaneous activity of cardiomyocytes was observed with resemblance to the action potential pattern of genuine pacemaker cells.
Meanwhile, other genes and cells have been discovered, including heart muscle cells derived from embryonic stem cells, "HCN" genes which encode the wild type pacemaker current I(f). Michael Rosen's group demonstrated that transplantation of HCN2-transfected human mesenchymal stem cells (hMSCs) leads to expression of functional HCN2 channels in vitro and in vivo, mimicking overexpression of HCN2 genes in cardiac myocytes. In 2010, Ruhparwar's group again demonstrated a type of biological pacemaker, this time showing that by injection of the "Adenylate Cyclase" gene into the heart muscle a biological cardiac pacemaker can be created.
In 2014, a gene called TBX18 has been non-invasively applied to speed up heart rates caused by heart block. More recent studies in 2015, has been experimented optogenetic approach in the rats heart, where a light sensitive transgene (Channelrhodopsin-2) injected to several sites of rat's ventricular, which, furthermore, can simultaneously stimulate the injection sites by a blue light irradiation.
References
American inventions
Cardiac electrophysiology
Embedded systems
Implants (medicine)
Neuroprosthetics
Prosthetics | Biological pacemaker | Technology,Engineering | 687 |
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