text stringlengths 60 353k | source stringclasses 2 values |
|---|---|
**Zebra (pen manufacturer)**
Zebra (pen manufacturer):
Zebra Co., Ltd. (ゼブラ株式会社, Zebura Kabushiki gaisha) is a Japanese manufacturer of writing instruments, established in 1914 by Tokumatsu Ishikawa.The company sells a wide range of writing implements through retail stores, wholesalers and mail order. Zebra offers a line of writing instruments that include fountain, ballpoint, brush and gel pens, markers, highlighters and mechanical pencils.
History:
Tokumatsu Ishikawa had begun to produce home-made nibs in 1897, until he established its own business in 1914, registering the name "Zebra" as a trademark. Ishikawa thought Zebra was an appropriate name because his goal was to build a business culture that resembled a family and zebras have a strong herding instinct. Zebra stripes resembling calligraphic pen strokes may also have been a reason for the name.In 1945, the Zebra facilities were destroyed during a bomb attack in World War II, but those would be reconstructed during the 1950s. In 1959 Zebra launched its first ballpoint pen manufactured. Four years later, the company renamed "Zebra Co., Ltd", with Hideaki Ishikawa becoming president of the firm.During the 1970s, Zebra marketed its first lines of markers, including brush-tip models, opening a new factory in Tokyo (1979). Zebra opened a subsidiary in the United States (1982). The 1990s and 2000s decade came with new subsidiaries in Canada, Indonesia, China, Mexico, and the United Kingdom.
Products:
Zebra's line of pens and pencils include "The Original" F-301 and the M-301, which have stainless steel barrels and textured grips. Other product lines include Blen, Surari, Filare (emulsion ink ballpoint pens); Airfit, Z-Grip (ballpoint pen); Sarasa, Sarasa Dry (gel pens); Sharbo (multi-pens); CLiCKART (water-based coloring markers); DelGuard, Tect 2Way (mechanical pencils); Zensations (art products), Mildliner (double ended creative markers), Zebrite (double ended highlighters), and Zazzle (liquid highlighters). Zebra products are available across the US, Canada, Mexico, UK, Singapore, Korea, and Japan.
Products:
Z-Grip In 2017, the Z-Grip line of retractable gel pens was transitioned to low viscosity ink, aka advanced ink. The benefits of the new formula, in addition to a smoother writing experience, was more vibrant colors and an option to create more nuanced hues.
Products:
Steel The Steel line of pens follows a good, better, best hierarchy; 3-series, 4-series, and 7-series respectively. The 301 series is characterized by stainless steel shafts and hardened plastic grips. The 401 has the same stainless steel shaft with a rubber grip. Finally, the flagship pen, the 701 has a knurled grip and is completely stainless steel. A cross section of these barrel styles reflect different ink types. For example, the 3-series barrel is available in ballpoint, gel, mechanical pencil, fountain pen, highlighter, and rollerball pen. All Zebra stainless steel products are refillable, including leads and mechanical pencil erasers.
Products:
Sarasa Dry The company transitioned all their plastic gel pens from different brands and consolidated under one name, Sarasa Dry. All the former products were reformulated to feature Zebra's award-winning Rapid Dry Ink technology, which was third party laboratory, tested and proven to be as fast or faster drying than the competition on a variety of surfaces and dries in less than a second on most surfaces. The assortment, X1, X10, X20, and X30, reflect different barrel styles to accommodate most consumer preferences.
Products:
Surari Range of "emulsion-ink" hybrid ink oil-based ballpoint pens, similar to Uni's Jetstream, Pentel's Vicuna and Pilot's Acroball.
Products:
Zensations Zebra entered the art and activity space with the launch of their Zensations brand of products, geared towards new and amateur artists looking for a slightly higher quality than products solely created for children. The brand encompasses technical pens and pencils, refillable colored mechanical pencils, fineliner markers, calligraphy pens, brush pens (black and colors), and more. Line extensions are developed periodically to refresh the line.
Products:
DelGuard A mechanism employed in the DelGuard system developed by Zebra, causes the lead sleeve in a mechanical pencil to extend outward when excessive pressure is applied at an angle. When excess vertical pressure is applied on the lead, the lead is automatically retracted inwards. Thus, the lead is protected (within certain limits) in both cases. In Japan, 0.3 and 0.7 versions of the DelGuard is available alongside the 0.5 version, whereas in the US, only the 0.5 version is available.
Products:
Sharbo Sharbo is a line of multifunction pens. A pen may contain one or more ink refills plus a mechanical pencil component. Examples are Sharbo X and SK-Sharbo+1. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Quadratic field**
Quadratic field:
In algebraic number theory, a quadratic field is an algebraic number field of degree two over Q , the rational numbers.
Quadratic field:
Every such quadratic field is some Q(d) where d is a (uniquely defined) square-free integer different from 0 and 1 . If d>0 , the corresponding quadratic field is called a real quadratic field, and, if d<0 , it is called an imaginary quadratic field or a complex quadratic field, corresponding to whether or not it is a subfield of the field of the real numbers.
Quadratic field:
Quadratic fields have been studied in great depth, initially as part of the theory of binary quadratic forms. There remain some unsolved problems. The class number problem is particularly important.
Discriminant:
For a nonzero square free integer d , the discriminant of the quadratic field K=Q(d) is d if d is congruent to 1 modulo 4 , and otherwise 4d . For example, if d is −1 , then K is the field of Gaussian rationals and the discriminant is −4 . The reason for such a distinction is that the ring of integers of K is generated by (1+d)/2 in the first case and by d in the second case.
Discriminant:
The set of discriminants of quadratic fields is exactly the set of fundamental discriminants.
Prime factorization into ideals:
Any prime number p gives rise to an ideal pOK in the ring of integers OK of a quadratic field K . In line with general theory of splitting of prime ideals in Galois extensions, this may be p is inert (p) is a prime ideal.
Prime factorization into ideals:
The quotient ring is the finite field with p2 elements: OK/pOK=Fp2 .p splits (p) is a product of two distinct prime ideals of OK The quotient ring is the product OK/pOK=Fp×Fp .p is ramified (p) is the square of a prime ideal of OK The quotient ring contains non-zero nilpotent elements.The third case happens if and only if p divides the discriminant D . The first and second cases occur when the Kronecker symbol (D/p) equals −1 and +1 , respectively. For example, if p is an odd prime not dividing D , then p splits if and only if D is congruent to a square modulo p . The first two cases are, in a certain sense, equally likely to occur as p runs through the primes—see Chebotarev density theorem.The law of quadratic reciprocity implies that the splitting behaviour of a prime p in a quadratic field depends only on p modulo D , where D is the field discriminant.
Class group:
Determining the class group of a quadratic field extension can be accomplished using Minkowski's bound and the Kronecker symbol because of the finiteness of the class group. A quadratic field K=Q(d) has discriminant so the Minkowski bound is Then, the ideal class group is generated by the prime ideals whose norm is less than MK . This can be done by looking at the decomposition of the ideals (p) for p∈Z prime where |p|<Mk.
Class group:
page 72 These decompositions can be found using the Dedekind–Kummer theorem.
Quadratic subfields of cyclotomic fields:
The quadratic subfield of the prime cyclotomic field A classical example of the construction of a quadratic field is to take the unique quadratic field inside the cyclotomic field generated by a primitive p th root of unity, with p an odd prime number. The uniqueness is a consequence of Galois theory, there being a unique subgroup of index 2 in the Galois group over Q . As explained at Gaussian period, the discriminant of the quadratic field is p for p=4n+1 and −p for p=4n+3 . This can also be predicted from enough ramification theory. In fact, p is the only prime that ramifies in the cyclotomic field, so p is the only prime that can divide the quadratic field discriminant. That rules out the 'other' discriminants −4p and 4p in the respective cases.
Quadratic subfields of cyclotomic fields:
Other cyclotomic fields If one takes the other cyclotomic fields, they have Galois groups with extra 2 -torsion, so contain at least three quadratic fields. In general a quadratic field of field discriminant D can be obtained as a subfield of a cyclotomic field of D th roots of unity. This expresses the fact that the conductor of a quadratic field is the absolute value of its discriminant, a special case of the conductor-discriminant formula.
Orders of quadratic number fields of small discriminant:
The following table shows some orders of small discriminant of quadratic fields. The maximal order of an algebraic number field is its ring of integers, and the discriminant of the maximal order is the discriminant of the field. The discriminant of a non-maximal order is the product of the discriminant of the corresponding maximal order by the square of the determinant of the matrix that expresses a basis of the non-maximal order over a basis of the maximal order. All these discriminants may be defined by the formula of Discriminant of an algebraic number field § Definition.
Orders of quadratic number fields of small discriminant:
For real quadratic integer rings, the ideal class number, which measures the failure of unique factorization, is given in OEIS A003649; for the imaginary case, they are given in OEIS A000924.
Some of these examples are listed in Artin, Algebra (2nd ed.), §13.8. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Annex**
Annex:
Annex or annexe may refer to:
Places:
The Annex, a neighbourhood in downtown Toronto, Ontario, Canada The Annex (New Haven), a neighborhood of New Haven, Connecticut, US Annex, Oregon, a census-designated place in the US
Other uses:
Annex (comics), a Marvel Comics character Addendum or appendix at the end of a document The Annex, Grand Cayman, a football ground in George Town, Cayman Islands "Annex", B-side of the 1980 Orchestral Manoeuvres in the Dark single "Enola Gay" Annex, an early name for the Bangkok Adventist Hospital "Annex" is a place in oregon | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Quantitative proteomics**
Quantitative proteomics:
Quantitative proteomics is an analytical chemistry technique for determining the amount of proteins in a sample. The methods for protein identification are identical to those used in general (i.e. qualitative) proteomics, but include quantification as an additional dimension. Rather than just providing lists of proteins identified in a certain sample, quantitative proteomics yields information about the physiological differences between two biological samples. For example, this approach can be used to compare samples from healthy and diseased patients. Quantitative proteomics is mainly performed by two-dimensional gel electrophoresis (2-DE), preparative one-dimensional gel electrophoresis, or mass spectrometry (MS). However, a recent developed method of quantitative dot blot (QDB) analysis is able to measure both the absolute and relative quantity of an individual proteins in the sample in high throughput format, thus open a new direction for proteomic research. In contrast to 2-DE, which requires MS for the downstream protein identification, MS technology can identify and quantify the changes.
Quantification using spectrophotometry:
The concentration of a certain protein in a sample may be determined using spectrophotometric procedures. The concentration of a protein can be determined by measuring the OD at 280 nm on a spectrophotometer, which can be used with a standard curve assay to quantify the presence of tryptophan, tyrosine, and phenylalanine. However, this method is not the most accurate because the composition of proteins can vary greatly and this method would not be able to quantify proteins that do not contain the aforementioned amino acids. This method is also inaccurate due to the possibility of nucleic acid contamination. Other more accurate spectrophotometric procedures for protein quantification include the Biuret, Lowry, BCA, and Bradford methods. An alternative method for label free protein quantification in clear liquid is cuvette-based SPR technique, that simultaneously measures the refractive index ranging 1.0 to 1.6 nD and concentration of the protein ranging from 0.5 µL to 2 mL in volume. This system consists of the calibrated optical filter with very high angular resolution and the interaction of light with this crystal forms a resonance at a wavelength which correlates to concentration and refractive index near the crystal.
Quantification using two dimensional electrophoresis:
Two-dimensional gel electrophoresis (2-DE) represents one of the main technologies for quantitative proteomics with advantages and disadvantages. 2-DE provides information about the protein quantity, charge, and mass of the intact protein. It has limitations for the analysis of proteins larger than 150 kDa or smaller than 5kDa and low solubility proteins. Quantitative MS has higher sensitivity but does not provide information about the intact protein.
Quantification using two dimensional electrophoresis:
Classical 2-DE based on post-electrophoretic dye staining has limitations: at least three technical replicates are required to verify the reproducibility. Difference gel electrophoresis (DIGE) uses fluorescence-based labeling of the proteins prior to separation has increased the precision of quantification as well as the sensitivity in the protein detection. Therefore, DIGE represents the current main approach for the 2-DE based study of proteomes.
Quantification using mass spectrometry:
Mass spectrometry (MS) represents one of the main technologies for quantitative proteomics with advantages and disadvantages. Quantitative MS has higher sensitivity but can provide only limited information about the intact protein. Quantitative MS has been used for both discovery and targeted proteomic analysis to understand global proteomic dynamics in populations of cells (bulk analysis) or in individual cells (single-cell analysis).Early approaches developed in the 1990s applied isotope-coded affinity tags (ICAT), which uses two reagents with heavy and light isotopes, respectively, and a biotin affinity tag to modify cysteine containing peptides. This technology has been used to label whole Saccharomyces cerevisiae cells, and, in conjunction with mass spectrometry, helped lay the foundation of quantitative proteomics. This approach has been superseded by isobaric mass tags, which are also used for single-cell protein analysis.
Quantification using mass spectrometry:
Relative and absolute quantification Mass spectrometry is not inherently quantitative because of differences in the ionization efficiency and/or detectability of the many peptides in a given sample, which has sparked the development of methods to determine relative and absolute abundance of proteins in samples. The intensity of a peak in a mass spectrum is not a good indicator of the amount of the analyte in the sample, although differences in peak intensity of the same analyte between multiple samples accurately reflect relative differences in its abundance.
Quantification using mass spectrometry:
Stable isotope labeling in mass spectrometry Stable isotope labels An approach for relative quantification that is more costly and time-consuming, though less sensitive to experimental bias than label-free quantification, entails labeling the samples with stable isotope labels that allow the mass spectrometer to distinguish between identical proteins in separate samples. One type of label, isotopic tags, consist of stable isotopes incorporated into protein crosslinkers that causes a known mass shift of the labeled protein or peptide in the mass spectrum. Differentially labeled samples are combined and analyzed together, and the differences in the peak intensities of the isotope pairs accurately reflect difference in the abundance of the corresponding proteins.
Quantification using mass spectrometry:
Absolute proteomic quantification using isotopic peptides entails spiking known concentrations of synthetic, heavy isotopologues of target peptides into an experimental sample and then performing LC-MS/MS. As with relative quantification using isotopic labels, peptides of equal chemistry co-elute and are analyzed by MS simultaneously. Unlike relative quantification, though, the abundance of the target peptide in the experimental sample is compared to that of the heavy peptide and back-calculated to the initial concentration of the standard using a pre-determined standard curve to yield the absolute quantification of the target peptide.
Quantification using mass spectrometry:
Relative quantification methods include isotope-coded affinity tags (ICAT), isobaric labeling (tandem mass tags (TMT) and isobaric tags for relative and absolute quantification (iTRAQ)), label-free quantification metal-coded tags (MeCAT), N-terminal labelling, stable isotope labeling with amino acids in cell culture (SILAC), and terminal amine isotopic labeling of substrates (TAILS). A mathematically rigorous approach that integrates peptide intensities and peptide-measurement agreement into confidence intervals for protein ratios has emerged.Absolute quantification is performed using selected reaction monitoring (SRM).
Quantification using mass spectrometry:
Metal-coded tags Metal-coded tags (MeCAT) method is based on chemical labeling, but rather than using stable isotopes, different lanthanide ions in macrocyclic complexes are used. The quantitative information comes from inductively coupled plasma MS measurements of the labeled peptides. MeCAT can be used in combination with elemental mass spectrometry ICP-MS allowing first-time absolute quantification of the metal bound by MeCAT reagent to a protein or biomolecule. Thus it is possible to determine the absolute amount of protein down to attomole range using external calibration by metal standard solution. It is compatible to protein separation by 2D electrophoresis and chromatography in multiplex experiments. Protein identification and relative quantification can be performed by MALDI-MS/MS and ESI-MS/MS.
Quantification using mass spectrometry:
Mass spectrometers have a limited capacity to detect low-abundance peptides in samples with a high dynamic range. The limited duty cycle of mass spectrometers also restricts the collision rate, resulting in an undersampling. Sample preparation protocols represent sources of experimental bias.
Quantification using mass spectrometry:
Stable isotope labeling with amino acids in cell culture Stable isotope labeling with amino acids in cell culture (SILAC) is a method that involves metabolic incorporation of “heavy” C- or N-labeled amino acids into proteins followed by MS analysis. SILAC requires growing cells in specialized media supplemented with light or heavy forms of essential amino acids, lysine or arginine. One cell population is grown in media containing light amino acids while the experimental condition is grown in the presence of heavy amino acids. The heavy and light amino acids are incorporated into proteins through cellular protein synthesis. Following cell lysis, equal amounts of protein from both conditions are combined and subjected to proteotypic digestion. Arginine and lysine amino acids were chosen, because trypsin, the predominant enzyme used to generate proteotypic peptides for MS analysis, cleaves at the C-terminus of lysine and arginine. Following digestion with trypsin, all the tryptic peptides from cells grown in SILAC media would have at least one labeled amino acid, resulting in a constant mass shift from the labeled sample over non-labeled. Because the peptides containing heavy and light amino acids are chemically identical, they co-elute during reverse-phase column fractionation and are detected simultaneously during MS analysis. The relative protein abundance is determined by the relative peak intensities of the isotopically distinct peptides.
Quantification using mass spectrometry:
Traditionally the level of multiplexing in SILAC was limited due to the number of SILAC isotopes available. Recently, a new technique called NeuCode SILAC, has augmented the level of multiplexing achievable with metabolic labeling (up to 4). The NeuCode amino acid method is similar to SILAC but differs in that the labeling only utilizes heavy amino acids. The use of only heavy amino acids eliminates the need for 100% incorporation of amino acids needed for SILAC. The increased multiplexing capability of NeuCode amino acids is from the use of mass defects from extra neutrons in the stable isotopes. These small mass differences however need to be resolved on high resolution mass spectrometers.
Quantification using mass spectrometry:
One of the main benefits of SILAC is the level of quantitation bias from processing errors is low because heavy and light samples are combined before sample preparation for MS analysis. SILAC and NeuCode SILAC are excellent techniques for detecting small changes in protein levels or post-translational modifications between experimental groups.
Quantification using mass spectrometry:
Isobaric labeling Isobaric mass tags (tandem mass tags) are tags that have identical mass and chemical properties that allow heavy and light isotopologues to co-elute together. All mass tags consist of a mass reporter that has a unique number of 13C substitutions, a mass normalizer that has a unique mass that balances the mass of the tag to make all the tags equal in mass and a reactive moiety that crosslinks to the peptides. These tags are designed to cleave at a specific linker region upon high-energy CID, yielding different-sized tags that are then quantitated by LC-MS/MS. Protein or peptide samples prepared from cells, tissues or biological fluids are labeled in parallel with the isobaric mass tags and combined for analysis. Protein quantitation is accomplished by comparing the intensities of the reporter ions in the MS/MS spectra. Three types of tandem mass tags are available with different reactivity: (1) reactive NHS ester which provides high-efficiency, amine-specific labeling (TMTduplex, TMTsixplex, TMT10plex and TMT11plex), (2) reactive iodacetyl function group which labels sulfhydryl-(-SH) groups (iodoTMT) and (3) reactive alkoxyamine functional group which provides covalent labeling of carbonyl-containing compounds (aminoxyTMT).
Quantification using mass spectrometry:
A key benefit of isobaric labeling over other quantification techniques (e.g. SILAC, ICAT, Label-free) is the increased multiplex capabilities and thus increased throughput potential. The ability to combine and analyze several samples simultaneously in one LC-MS run eliminates the need to analyze multiple data sets and eliminates run-to-run variation. Multiplexing reduces sample processing variability, improves specificity by quantifying the proteins from each condition simultaneously, and reduces turnaround time for multiple samples. The current available isobaric chemical tags facilitate the simultaneous analysis of up to 11 experimental samples.
Quantification using mass spectrometry:
Label-free quantification in mass spectrometry One approach for relative quantification is to separately analyze samples by MS and compare the spectra to determine peptide abundance in one sample relative to another, as in label-free strategies. It is generally accepted, that while label-free quantification is the least accurate of the quantification paradigms, it is also inexpensive and reliable when put under heavy statistical validation. There are two different methods of quantification in label-free quantitative proteomics: AUC (area under the curve) and spectral counting.
Quantification using mass spectrometry:
Methods of label-free quantification AUC is a method by which for a given peptide spectrum in an LC-MS run, the area under the spectral peak is calculated. AUC peak measurements are linearly proportional to the concentration of protein in a given analyte mixture. Quantification is achieved through ion counts, the measurement of the amount of an ion at a specific retention time. Discretion is required for the standardization of the raw data. High-resolution spectrometer can alleviate problems that arise when trying to make data reproducible, however much of the work regarding normalizing data can be done through software such as OpenMS, and MassView.Spectral counting involves counting the spectra of an identified protein and then standardizing using some form of normalization. Typically this is done with an abundant peptide mass selection (MS) that is then fragmented and then MS/MS spectra are counted. Multiple samplings of the protein peak is required for accurate estimation of the protein abundance because of the complex physiochemical nature of peptides. Thus, optimization for MS/MS experiments is a constant concern. One alternative to get around this problems is use a data independent technique that cycles between high and low collision energies. Thus a large survey of all possible precursor and product ions is collected. This is limited, however, by the mass spectrometry software's ability to recognize and match peptide patterns of associations between the precursor and product ions.
Applications:
Biomedical applications Quantitative proteomics has distinct applications in the medical field. Especially in the fields of drug and biomarker discovery. LC-MS/MS techniques have started to over take more traditional methods like the western blot and ELISA due to the cumbersome nature of labeling different and separating proteins using these methods and the more global analysis of protein quantification. Mass spectrometry methods are more sensitive to difference in protein structure like post-translational modification and thus can quantify differing modifications to proteins. Quantitative proteomics can circumvent these issues, only needing sequence information to be performed. It can be applied on a global proteome level, or on specifically isolating binding partners in pull-down or affinity purification experiments. Disadvantages, however, in sensitivity and analysis time must be kept in consideration.
Applications:
Drug discovery Quantitative proteomics has the largest applications in the protein target identification, protein target validation, and toxicity profiling of drug discovery. Drug discovery has been used to investigate protein-protein interaction and, more recently, drug-small molecule interactions, a field of study called chemoproteomics. Thus, it has shown great promise in monitoring side-effects of small drug-like molecules and understanding the efficacy and therapeutic effect of one drug target over another. One of the more typical methodologies for absolute protein quantification in drug discovery is the use of LC-MS/MS with multiple reaction monitoring (MRM). The mass spectrometry is typically done by a triple quadrupole MS. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Signal Transduction and Targeted Therapy**
Signal Transduction and Targeted Therapy:
Signal Transduction and Targeted Therapy is a multidisciplinary peer-reviewed open access scientific journal covering biomedical research with a particular focus on signal transduction and its application to the drug development process. It was established in 2016 and is published by Nature Research. The editors-in-chief are Carlo M. Croce (Ohio State University), Kang Zhang (Macau University of Science and Technology), and Yu-Quan Wei (West China Medical Center). According to the Journal Citation Reports, the journal has a 2020 impact factor of 18.187. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Alarsite**
Alarsite:
Alarsite (AlAsO4) is an aluminium arsenate mineral with its name derived from its composition: aluminium and arsenate. It occurs as brittle subhedral grains which exhibit trigonal symmetry. It has a Mohs hardness of 5-5.5 and a specific gravity of 3.32. It is semitransparent, colorless with pale yellow tints and shows a vitreous luster. It is optically uniaxial (+) with refractive indices of nω = 1.596 and nε = 1.608.
Alarsite:
It was reported from fumaroles in the Tolbachik volcano, Kamchatka, Far Eastern Region, Russia. It occurs in association with fedotovite, klyuchevskite, lammerite, nabokoite, atlasovite, langbeinite, hematite and tenorite. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Far-Play**
Far-Play:
Far-Play (stylized fAR-Play, from augmented reality) is a software platform developed at the University of Alberta, for creating location-based, scavenger-hunt style games which use the GPS and web-connectivity features of a player's smartphone. According to the development team, "our long-term objective is to develop a general framework that supports the implementation of AARGs that are fun to play and also educational". It utilizes Layar, an augmented reality smartphone application, QR codes located at particular real-world sites, or a phone's web browser, to facilitate games which require players to be in close physical proximity to predefined "nodes". A node, referred to by the developers as a Virtual Point of Interest (vPOI), is a point in space defined by a set of map coordinates; fAR-Play uses the GPS function of a player's smartphone — or, for indoor games, which are not easily tracked by GPS satellites, specially-created QR codes— to confirm that they are adequately near a given node. Once a player is within a node's proximity, Layar's various augmented reality features can be utilized to display a range of extra content overlaid upon the physical play-space or launch another application for extra functionality.
Development and features:
fAR-Play began development in 2008, emerging from a collaborative project undertaken by a group of University of Alberta students from the Computer Science and Humanities Computing departments. fAR-Play is still under development, but a beta version is available for testing by request. fAR-Play's development is managed by a team of interdisciplinary professors and students at the University of Alberta. Currently, the developing team's roster includes Supervising Professors Geoffrey Rockwell and Eleni Stroulia, Developers Lucio Gutierrez and Matthew Delaney, and Website Developers Calen Henry and Garry Wong.
Development and features:
Technology fAR-Play relies on a number of open- and closed-source web technologies as tools to create, and enhance the users' experience. Layar is the recommended client-side frontend for delivering game content to the player; it is available on Android and iOS, which covers over 91% of smartphones. While Layar is not a requirement to play fAR-Play games, the application does supply additional augmented reality functionality; Layar also includes a built-in QR scanner. Depending on the design of the particular game, the player may instead use a dedicated QR code scanner; the developers recommend BeeTagg, but any such application will do. Layar or a QR code scanner are the maximum software requirements to play a fAR-Play game, making implementation of games on a wide variety of platforms relatively straightforward. fAR-Play games can also be designed for play strictly within a mobile phone's web browser. On the server side, fAR-Play's engine is composed of an Apache server which manages the system's web interface, including the mobile and desktop versions of the fAR-Play website, and a Java-based REST framework for managing the database of nodes.
Development and features:
Features As a platform for designing AR games, as opposed to an AR game itself, fAR-Play offers little in the way of explicit shapes or patterns for games to take; instead, these elements are left to the game designer or players to develop. However, the nonspecific nature of nodes, the many options they offer for content delivery, and the open design of the platform are such that these elements can be developed extensively. Functionally, fAR-Play is a tool for tracking arbitrary points in space and a given player's proximity to them; what it does beyond that is up to the developers' and players' discretion. However, the fAR-Play website contains a leaderboard which tracks registered user's total scores. Players are assigned levels based on their total score, ranging from Novice — Super Player. Player profiles will display nodes that the player has recently caught, and any achievements the player has gained. Additionally, players can share their adventure progress, achievements, and the capture of vPOIs on Facebook.
How to play:
In order to participate in the locative aspects of fAR-Play games, users must have an Android or iOS mobile device and access to wireless internet. Players can participate in fAR-Play anonymously, or create and sign into a fAR-Play account. Those who choose to play anonymously will lose the ability to track their progress across multiple games. When signed in, the player is presented with a list of games that are currently available for play. Each game includes a brief description and the various "adventures" available to the player. Once the game has been started, the player has three different methods for capturing nodes: they may scan a QR in the physical space, discover a node through the Layar camera virtual view, or receive a link in their device's web browser.
How to play:
QR codes and Layar QR codes can only be used as a method for capturing nodes and initiating games when there is a physical code present. In order to scan a QR code, players are required to have an application which can capture and recognize QR codes. If the player is utilizing a QR scanning application that has a built in browser, they will be required to log into fAR-Play through the app. Layar is a free to download augmented reality app, containing a built in QR code scanner, which enables its users to participate in fAR-Play games.
How to play:
Capturing nodes Layar permits the player to see nodes on their mobile device, guiding the player to their goal. Using this application, the player is able to navigate to their objective with map provided by Google Maps' API or by using their camera — Layar overlays a virtual image onto the real-world scene presented by the camera. The representations on screen expand in size as the player approaches the node destination, simulating relative distance. If the player taps any of the nodes that are presented on the screen, they will be provided additional information about that node, including the node's name and a brief description. Nodes can be captured by tapping the "capture" button.
How to play:
Playing on browsers The player can also play fAR-Play games within their mobile device's browser. By visiting https://archive.today/20131123223038/http://farplay.ualberta.ca/far-play/ on a mobile device, players will be presented with a fully realized user interface, permitting full interaction with the games. The player can capture the in game vPOIs through their browser by tapping the "nodes" button. This will bring up a list of all the accessible nodes, complete with a brief description for each location. By clicking on one of the nodes, the player is shown to a screen with a mapped location of the vPOI, an in-depth description of it, and hints. At the top of the page, the player can tap "CAPTURE THIS NODE" and advance in the game. When attempting to capture a node, the developer may or may not associate a challenge with the node. For example, in the game "Zombies ate my Campus", when players are attempting to capture a node, they're presented with a multiple choice question associated with the current node.
How to play:
Game types Players complete an adventure when they have captured all of the nodes within it. fAR-Play provides two game modes: in a Virtual Scavenger Hunt, nodes must be captured in a specific order; in a Virtual Treasure Hunt, the order is unimportant.
Existing fAR-Play games:
Games currently available through fAR-Play include: Giselle Ever After Thought Hub Comics Arts Capture Challenge Pioneering Edmonton The Intelliphone Challenge A Tour of Atwater Zombies ate my Campus
For developers:
fAR-Play's ultimate goal is to provide a simple, effective platform for the creation of locative augmented reality games, but the developer tools are still under active development and not openly available to the public. Access can be granted on a case-by-case basis, however, and a developer's manual is available. Users with development privileges can create new games or edit their existing games, in addition to playing their own or others' games.
For developers:
Adventures Games that are developed with fAR-Play are segmented into components called "Adventures". To progress through each game adventure, the player must reach and capture virtual points of interest, referred to in the game as vPOIs. In order to capture a vPOI, the player must travel to a physical location that is set by the developer. It is the developer's choice to include a challenge question to capture the vPOI, though it is not mandatory. A deduction of points can be implemented if the player submits an incorrect answer to a challenge question.
For developers:
Points and achievements Each of the nodes will reward the player with a predetermined number of points once they have been captured by the player. These points are added to the player's total points. Each of the adventures that are created require a predetermined number of vPOIs to be completed before the player can advance. fAR-Play has the ability to implement achievements, which can reward players with extra points for completing certain tasks. The two general classifications of achievements in the game are: "Percentage of Adventure Completed" and "Percentage of Game Completed".
For developers:
Win conditions The developer must decide if the vPOIs must be completed in a certain order, or if the order is inconsequential. Additionally, the developer can choose if the win condition of an adventure requires all vPOIs to be captured, or only a certain percentage of them. Game creators can set a "Catch Limit" for each vPOI, which restricts the number of times each node may be captured. This can be used to encourage races and competitive play.
For developers:
Name, description and customization When developing a game for fAR-Play, the site requires that users submit a game name, game description, and game story. Each of the adventures within the game will also require a name, and type; Scavenger Hunt is currently the only available adventure type. For additional aesthetic customization, fAR-Play allows developers to utilize CSS to customize the appearance and layout of the player's interface.
For developers:
Hints The developer may implement a hint system within the game to guide players through the experience. These hints can take the form of an image, audio, or video file. To encourage the player to discover answers for themselves, the game can penalize players for the use of hints, reducing their points by a predetermined number.
Notes:
References Guiterrez, L., et al. "fAR-PLAY: a framework to develop augmented/alternate reality games." Second IEEE Workshop On Pervasive Collaboration and Social Networking. 2011.
Llamas, Ramon, et al. "Android and iOS Combine for 91.1% of the Worldwide Smartphone OS Market in 4Q12 and 87.6% for the Year, According to IDC." International Data Corporation. idc.com, 14 February 2013. Accessed 15 November 2013.
The fAR-Play Team. A Player's Guide to fAR-Play. farplay.ualberta.ca. ND. Accessed 15 November 2013.
The fAR-Play Team. "fAR-Play Developers' Manual". farplay.ualberta.ca. 27 September 2011. Accessed 15 November 2013.
The fAR-Play Team. fAR-Play.ualberta.ca. 2010. Accessed 15 November 2013. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Epigenetics of neurodegenerative diseases**
Epigenetics of neurodegenerative diseases:
Neurodegenerative diseases are a heterogeneous group of complex disorders linked by the degeneration of neurons in either the peripheral nervous system or the central nervous system. Their underlying causes are extremely variable and complicated by various genetic and/or environmental factors. These diseases cause progressive deterioration of the neuron resulting in decreased signal transduction and in some cases even neuronal death. Peripheral nervous system diseases may be further categorized by the type of nerve cell (motor, sensory, or both) affected by the disorder. Effective treatment of these diseases is often prevented by lack of understanding of the underlying molecular and genetic pathology. Epigenetic therapy is being investigated as a method of correcting the expression levels of misregulated genes in neurodegenerative diseases.
Epigenetics of neurodegenerative diseases:
Neurodengenerative diseases of motor neurons can cause degeneration of motor neurons involved in voluntary muscle control such as muscle contraction and relaxation. This article will cover the epigenetics and treatment of amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). See the Motor Neuron Fact Sheet for details regarding other motor neuron diseases. Neurodegenerative diseases of the central nervous system can affect the brain and/or spinal cord. This article will cover the epigenetics and treatment of Alzheimer’s disease (AD), Huntington’s disease (HD), and Parkinson’s disease (PD). These diseases are characterized by chronic and progressive neuronal dysfunction, sometimes leading to behavioral abnormalities (as with PD), and, ultimately, neuronal death, resulting in dementia.
Epigenetics of neurodegenerative diseases:
Neurodegenerative diseases of sensory neurons can cause degeneration of sensory neurons involved in transmitting sensory information such as hearing and seeing. The main group of sensory neuron diseases are hereditary sensory and autonomic neuropathies (HSAN) such as HSAN I, HSAN II, and Charcot-Marie-Tooth Type 2B (CMT2B). Though some sensory neuron diseases are recognized as neurodegenerative, epigenetic factors have not yet been clarified in the molecular pathology.
Epigenetics and epigenetic drugs:
The term epigenetics refers to three levels of gene regulation: (1) DNA methylation, (2) histone modifications, and (3) non-coding RNA (ncRNA) function. Briefly, histone-mediated transcriptional control occurs by the wrapping of DNA around a histone core. This DNA-histone structure is called a nucleosome; the more tightly the DNA is bound by the nucleosome, and the more tightly a string of nucleosomes are compressed among each other, the greater the repressive effect on transcription of genes in the DNA sequences near or wrapped around the histones, and vice versa (i.e. looser DNA binding and relaxed compaction leads to a comparatively derepressed state, resulting in facultative heterochromatin or, even further derepressed, euchromatin). At its most repressive state, involving many folds into itself and other scaffolding proteins, DNA-histone structures form constitutive heterochromatin. This chromatin structure is mediated by these three levels of gene regulation. The most relevant epigenetic modifications to treatment of neurodegenerative diseases are DNA methylation and histone protein modifications via methylation or acetylation.
Epigenetics and epigenetic drugs:
In mammals, methylation occurs on DNA and histone proteins. DNA methylation occurs on the cytosine of CpG dinucleotides in the genomic sequence, and protein methylation occurs on the amino termini of the core histone proteins - most commonly on lysine residues. CpG refers to a dinucleotide composed of a cytosine deoxynucleotide immediately adjacent to a guanine deoxynucleotide. A cluster of CpG dinucleotides clustered together is called a CpG island, and in mammals, these CpG islands are one of the major classes of gene promoters, onto or around which transcription factors may bind and transcription can begin. Methylation of CpG dinucleotides and/or islands within gene promoters is associated with transcriptional repression via interference of transcription factor binding and recruitment of transcriptional repressors with methyl binding domains. Methylation of intragenic regions is associated with increased transcription. The group of enzymes responsible for addition of methyl groups to DNA are called DNA methyltransferases (DNMTs). The enzyme responsible for removal of methyl group are called DNA demethylases. The effects of histone methylation are residue dependent (e.g. which amino acid on which histone tail is methylated) therefore the resulting transcriptional activity and chromatin regulation can vary. The enzymes responsible for the addition of methyl groups to histones are called histone methyltransferases (HMTs). The enzymes responsible for the removal of methyl groups from histone are histone demethylases.
Epigenetics and epigenetic drugs:
Acetylation occurs on the lysine residues found at the amino N-terminal of histone tails. Histone acetylation is most commonly associated with relaxed chromatin, transcriptional derepression, and thus actively transcribed genes. Histone acetyltransferases (HATs) are enzymes responsible for the addition of acetyl groups, and histone deacetylases (HDACs) are enzymes responsible for the removal of acetyl groups. Therefore, the addition or removal of an acetyl group to a histone can alter the expression of nearby genes. The majority of drugs being investigated are inhibitors of proteins that remove acetyl from histones or histone deacetylases (HDACs).
Epigenetics and epigenetic drugs:
Briefly, ncRNAs are involved in signaling cascades with epigenetic marking enzymes such as HMTs, and/or with RNA interference(RNAi) machinery. Frequently these signaling cascades result in epigenetic repression (for one example, see X-chromosome inactivation), though there are some cases in which the opposite is true. For example, BACE1-AS ncRNA expression is upregulated in Alzheimer's disease patients and results in increased stability of BACE1 - the mRNA precursor to an enzyme involved in Alzheimer's disease.Epigenetic drugs target the proteins responsible for modifications on DNA or histone. Current epigenetic drugs include but are not limited to: HDAC inhibitors (HDACi), HAT modulators, DNA methyltransferase inhibitors, and histone demethylase inhibitors. The majority of epigenetic drugs tested for use against neurodegenerative diseases are HDAC inhibitors; however, some DNMT inhibitors have been tested as well. While the majority of epigenetic drug treatments have been conducted in mouse models, some experiments have been performed on human cells as well as in human drug trials (see table below). There are inherent risks in using epigenetic drugs as therapies for neurodegenerative disorders as some epigenetic drugs (e.g. HDACis such as sodium butyrate) are non-specific in their targets, which leaves potential for off-target epigenetic marks causing unwanted epigenetic modifications.
Neurodegenerative diseases of motor neurons:
Amyotrophic lateral sclerosis (ALS) Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig's disease, is a motor neuron disease that involves neurogeneration. All skeletal muscles in the body are controlled by motor neurons that communicate signals from the brain to the muscle through a neuromuscular junction. When the motor neurons degenerate, the muscles no longer receive signals from the brain and begin to waste away. ALS is characterized by stiff muscles, muscle twitching, and progressive muscle weakness from muscle wasting. The parts of the body affected by early symptoms of ALS depend on which motor neurons in the body are damaged first, usually the limbs. As the disease progresses most patients are unable to walk or use their arms and eventually develop difficulty speaking, swallowing and breathing. Most patients retain cognitive function and sensory neurons are generally unaffected. Patients are often diagnosed after the age of 40 and the median survival time from onset to death is around 3–4 years. In the final stages, patients can lose voluntary control of eye muscles and often die of respiratory failure or pneumonia as a result of degeneration of the motor neurons and muscles required for breathing. Currently there is no cure for ALS, only treatments that may prolong life.
Neurodegenerative diseases of motor neurons:
Genetics and underlying causes To date, multiple genes and proteins have been implicated in ALS. One of the common themes between many of these genes and their causative mutations is the presence of protein aggregates in motor neurons. Other common molecular features in ALS patients are altered RNA metabolism and general histone hypoacetylation.
Neurodegenerative diseases of motor neurons:
SOD1 The SOD1 gene on chromosome 21 that codes for the superoxide dismutase protein is associated with 2% of cases and is believed to be transmitted in an autosomal dominant manner. Many different mutations in SOD1 have been documented in ALS patients with varying degrees of progressiveness. SOD1 protein is responsible for destroying naturally occurring, but harmful superoxide radicals produced by the mitochondria. Most of the SOD1 mutations associated with ALS are gain-of-function mutations in which the protein retains its enzymatic activity, but aggregate in motor neurons causing toxicity. Normal SOD protein is also implicated in other cases of ALS due to potentially cellular stress. An ALS mouse model through gain-of-function mutations in SOD1 has been developed.
Neurodegenerative diseases of motor neurons:
c9orf72 A gene called c9orf72 was found to have a hexanucleotide repeat in the non-coding region of the gene in association with ALS and ALS-FTD. These hexanucleotide repeats may be present in up 40% of familial ALS cases and 10% of sporadic cases. C9orf72 likely functions as a guanine exchange factor for a small GTPase, but this is likely not related to the underlying cause of ALS. The hexanucleotide repeats are likely causing cellular toxicity after they are spliced out of the c9orf72 mRNA transcripts and accumulate in the nuclei of affected cells.
Neurodegenerative diseases of motor neurons:
UBQLN2 The UBQLN2 gene encodes the protein ubiquilin 2 which is responsible for controlling the degradation of ubiquitinated proteins in the cell. Mutations in UBQLN2 interfere with protein degradation resulting in neurodegeneration through abnormal protein aggregation. This form of ALS is X chromosome-linked and dominantly inherited and can also be associated with dementia.
Epigenetic treatment with HDAC inhibitors ALS patients and mouse models show general histone hypoacetylation that can ultimately trigger apoptosis of cells. In experiments with mice, HDAC inhibitors counteract this hypoacetylation, reactivate aberrantly down-regulated genes, and counteract apoptosis initiation. Furthermore, HDAC inhibitors are known to prevent SOD1 protein aggregates in vitro.
Neurodegenerative diseases of motor neurons:
Sodium phenylbutyrate Sodium phenylbutyrate treatment in a SOD1 mouse model of ALS showed improved motor performance and coordination, decreased neural atrophy and neural loss, and increased weight gain. Release of pro-apoptotic factors was also abrogated as well as a general increase in histone acetylation. A human trial using phenylbuturate in ALS patients showed some increase in histone acetylation, but the study did not report whether ALS symptoms improved with treatment.
Neurodegenerative diseases of motor neurons:
Valproic scid Valproic acid in mice studies restored histone acetylation levels, increased levels of pro-survival factors, and mice showed improved motor performance. However, while the drug delayed the onset of ALS, it did not increase lifespan or prevent denervation. Human trials of valproic acid in ALS patients did not improve survival or slow progression.
Trichostatin A Trichostatin A trials in mouse ALS models restored histone acetylation in spinal neurons, decreased axon demyelination, and increased survival of mice.
Neurodegenerative diseases of motor neurons:
Spinal Muscular Atrophy (SMA) Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease caused by mutations in the SMN1 gene. Symptoms vary greatly with each subset of SMA and the stage of the disease. General symptoms include overall muscle weakness and poor muscle tone including extremities and respiratory muscles leading to difficulty walking, breathing, and feeding. Depending on the type of SMA, the disease can present itself from infancy through adulthood. As SMN protein generally promotes the survival of motor neurons, mutations in SMN1 results in slow degeneration motor neurons leading to progressive system-wide muscle wasting. Specifically, over time, decreased levels of SMN protein results in gradual death of the alpha motor neurons in the anterior horn of the spinal cord and brain. Muscles depend on connections to motor neurons and the central nervous system to stimulate muscle maintenance and therefore degeneration of motor neurons and subsequent denervation of muscles lead to loss of muscle control and muscle atrophy. The muscles of the lower extremities are often affected first followed by upper extremities and sometimes the muscles of respiration and mastication. In general, proximal muscle is always affected more than distal muscle.
Neurodegenerative diseases of motor neurons:
Genetic cause Spinal muscular atrophy is linked to genetic mutations in the SMN1 (Survival of Motor Neuron 1) gene. The SMN protein is widely expressed in neurons and serves many functions within neurons including spliceosome construction, mRNA axon transport, neurite outgrowth during development, and neuromuscular junction formation. The causal function loss in SMA is currently unknown.
Neurodegenerative diseases of motor neurons:
SMN1 is located in a telomeric region of human chromosome 5 and also contains SMN2 in a centromeric region. SMN1 and SMN2 are nearly identical except for a single nucleotide change in SMN2 resulting in an alternative splicing site where intron 6 meets exon 8. This single base pair change leads to only 10-20% of SMN2 transcripts resulting in fully functional SMN protein and 80-90% of transcripts leading to a truncated protein that is rapidly degraded. Most SMA patients have 2 or more copies of the SMN2 gene with more copies resulting in a decrease in disease severity. Most SMA patients have either point mutations or a deletion in exon 7 often leading to a protein product similar to the truncated and degraded version of the SMN2 protein. In SMA patients this small amount of functional SMN2 protein product allows for some neurons to survive.
Neurodegenerative diseases of motor neurons:
Epigenetic treatment through SMN2 gene activation Although SMA is not caused by an epigenetic mechanism, therapeutic drugs that target epigenetic marks may provide SMA patients with some relief, halting or even reversing the progression of the disease. As SMA patients with higher copy numbers of the SMN2 gene have less severe symptoms, researchers predicted that epigenetic drugs that increased SMN2 mRNA expression would increase the amount of functional SMN protein in neurons leading to a reduction in SMA symptoms. Histone deacetylase (HDAC) inhibitors are the main compounds that have been tested to increase SMN2 mRNA expression. Inhibiting HDACs would allow for hyperacetylation of the SMN2 gene loci theoretically resulting in an increase in SMN2 expression. Many of these HDAC inhibitors (HDACi) are first tested in mouse models of SMA created through a variety of mutations in the mouse SMN1 gene. If the mice show improvement and the drug does not cause very many side effects or toxicity, the drug may be used in human clinical trials. Human trials with all of the below HDAC inhibitors are extremely variable and often impacted by the patient's exact SMA subtype.
Neurodegenerative diseases of motor neurons:
Myasthenia Gravis Myasthenia gravis is an autoimmune disease affecting synapses at the neuromuscular junction, whereby antibodies produced primarily in the thymus gland by B-cells associate with postsynaptic nicotinic acetylcholine receptors (AChR), along with other NMJ post-synaptic receptors (MuSK-R and low-density lipoprotein receptor). These antibodies include acetylcholine receptor antibodies, MuSK antibodies, and low-density lipoprotein receptor related protein 4 antibodies (LRP4-Ab). Antibody binding to their respective receptors causes the destruction of those receptors, leading to a reduction in the number of postsynaptic acetylcholinergic receptors and a reduction in overall acetylcholine transport. Disease symptoms include muscular weakness that fatigues due to overuse, but improves with rest. Hallmark symptoms due to muscular weakness include ptosis, double vision, dysphagia, as well as aberrant speech.Myasthenia gravis is a relatively rare disease, occurring in about 3-30 individuals per 100,000, but has been rising over the past couple decades. There exists two variations of myasthenia gravis with respect to age and gender demographics: early-onset myasthenia gravis, which has a higher incidence among females, and late-onset myasthenia gravis, which has a higher incidence among males.
Neurodegenerative diseases of motor neurons:
Epigenetic Factors There has been extensive research on the genetic basis of myasthenia gravis, however evidence does not suggest that it is an inherited disease. There has also been extensive research on the epigenetic contribution to myasthenia gravis. DNA methylation and noncoding RNA, such as miRNA (micro RNA) and long noncoding RNA (lncRNA), are epigenetic factors that play a significant role in increasing the likelihood of acquiring myasthenia gravis. In addition, the thymus is a key organ in the immune response that is often negatively affected by abnormal miRNA expression and DNA methylation.
Neurodegenerative diseases of motor neurons:
miRNA Micro RNA (miRNA) are single-stranded non-coding RNAs that bind their target mRNAs. From there, they can regulate gene expression by inhibiting translation or degrading the mRNA strand, oftentimes in B-cells and T-cells of the immunological process. With respect to myasthenia gravis, abnormal miRNA function is associated with immunoregulatory pathogenesis, and each miRNA has its own unique downstream effects.
Neurodegenerative diseases of motor neurons:
The thymus is an important endocrine organ implicated in myasthenia gravis. In normal, healthy development, the thymus shrinks in size over time. In those with thymus-associated myasthenia gravis there are correlations with thymomas in late-onset myasthenia gravis as well as thymic hyperplasia with germinal centers in early-onset myasthenia gravis, and each of these conditions can be attributed partly to irregular miRNA function. In late-onset myasthenia gravis subjects, it was shown that miRNA-12a-5p expression was increased in thymoma-associated myasthenia gravis. MiRNA-12a-5p inhibits expression of the gene FoxP3, a gene known to be associated with normal thymus development and whose alteration is attributed to thymomas. Additionally, an association between thymoma-associated myasthenia gravis and decreased miR-376a/miR-376c expression was found. Autoimmune regulation is known to be downregulated in thymoma-associated myasthenia gravis, and in thymus cells with downregulated autoimmune regulation there was simultaneous downregulation in miR-376a, miR-376c, and miRNA-12a-5p expression. In early-onset myasthenia gravis patients, 61 miRNA's were found to be either significantly downregulated or upregulated. The most downregulated miRNA was found to be miR-7-5p, whose target gene is CCL21. CCL21 is known to aberrantly recruit B-cells in the thymus of early-onset myasthenia gravis patients, and was found to be highly expressed in early-onset myasthenia gravis patients, potentially explaining the abnormally large amounts of B cells found in thymic hyperplasia.Aside from miRNA's corresponding to altered thymus function, there are other several key miRNA's that are correlated with myasthenia gravis. MiR-15 cluster (miR-15a, miR-15b, and miR-15c) was shown to be associated with autoimmunity, in that its downregulation increased CXCL10 expression, a target gene involved in T-cell signaling. CXCL10 expression was also shown to be increased in the thymus of myasthenia gravis patients. Additionally, miR-146 was found to be upregulated in myasthenia gravis patients. In these patients with upregulated miR-146, there was a concurrent increase in proteins that correspond to a wide array of immune responses, specifically TLR4, CD40, and CD80.
Neurodegenerative diseases of motor neurons:
DNA Methylation DNA methylation is the epigenetic process by which methyl groups are added to either adenine or cytosine bases, which results in the repression of that sequence when cytosine methylation occurs. DNA methylation was found to be a factor in increasing the likelihood of acquiring myasthenia gravis, albeit this topic has not been widely researched. Research in China has identified the gene CTLA-4 (cytotoxic T lymphocyte antigen-4) as being highly methylated in myasthenia gravis patients compared to control groups throughout the entire span of the disease. The CTLA-4 gene produces an antigen of the same name that is presented on killer T-cells and allows for the suppression of the immune response. Methylation of this gene represses production of the antigen CTLA-4—a pattern seen in a significant majority of myasthenia gravis patients—and can explain the elevated immune response seen in myasthenia gravis. Furthermore, myasthenia gravis patients with thymic abnormalities (approximately 10-20% of all myasthenia gravis patients) had even higher levels of CTLA-4 methylation than other myasthenia gravis patients. It is not extensively researched why certain genes are hypermethylated in these cases, but information on myasthenia gravis largely points to upregulation of the DNA methyltransferase genes DNMT1, DNMT3A, and DNMT3B in patients with myasthenia gravis.In addition to CTLA-4 methylation, hypermethylation of the growth hormone secretagogue receptor gene was seen in patients with thymoma-associated late-onset myasthenia gravis. Growth hormone secretagogue receptor hypermethylation is detected in a wide variety of cancers, however only recently has been correlated with the development of thymoma-associated myasthenia gravis. Although it is seen in approximately 1/4 of thymoma-associated myasthenia gravis subjects, it is not a reliable biomarker for the disease, and its relevance to disease progression is not well known.
Neurodegenerative diseases of motor neurons:
Long ncRNA Long ncRNA (lncRNA) are a second type of non-coding RNA that are key post-transcriptional modifiers of protein-coding gene expression. These also play a significant role in myasthenia gravis. Their aberrant regulation can cause differential expression in downstream genes. For instance, the differential expression of lncRNA interferon gamma antisense RNA negatively regulates the expression of HLA-DRB and HLA-DOB, two genes implicated in the body's autoimmune response by differentiating endogenous and foreign proteins. As seen in myasthenia gravis patients with downregulated lethal (let)-7 lncRNA, it was also found that the level of let-7 lncRNA was negatively correlated with levels of interleukin (IL)-10, a gene responsible for inhibiting cytokine secretion/activation, antigen presentation, and macrophage activity, but also for exhibiting anti-tumor effects. Therefore, the negative correlation between let-7 lncRNA and IL-10 levels and its specific effects on myasthenia gravis development are ambiguous.
Neurodegenerative diseases of motor neurons:
In addition to aberrant regulation of downstream target genes, lncRNA also affect expression by acting as competing endogenous RNA (ceRNA). The competing endogenous RNA theory states that transcripts sharing common miRNA binding sites can compete to bind these identical miRNAs, and in this way lncRNAs can bind miRNAs, regulating their downstream binding activity and affecting their function. In the case of myasthenia gravis, the lncRNA small nucleolar RNA host gene (SNHG) 16 regulates the expression of IL-10 by adsorbing let-7c-5p, a miRNA that commonly associates with IL-10, as a competing endogenous RNA.
Neurodegenerative diseases of motor neurons:
Epigenetic Treatments Diagnosis of myasthenia gravis, individual prognosis, and the level of treatment needed can be determined by detecting the amounts of circulating miRNA.
Neurodegenerative diseases of motor neurons:
Immunosuppressants represent a large category in clinical studies for myasthenia gravis treatment, as they reduce the hyperactive immunological response in T-cells presenting acetylcholine receptor-binding antigens. By overexpressing miR-146, studies show that patients with early-onset myasthenia gravis can have antigen-specific suppressive effects. This has implications in reducing the immune response of myasthenia gravis patients and improving prognosis. Likewise, miR-155 is proven to be correlated with myasthenia gravis-associated thymic inflammation and immune response. Research is being conducted whereas repression of miR-155 could reduce these aberrant effects. Lastly, the miRNA's miR-150-5p and miR-21-5p are consistently shown to be elevated in myasthenia gravis patients with acetylcholinergic receptor antibodies (in contrast to the MuSK-binding variant of myasthenia gravis), therefore these two miRNA's are reliable biomarkers in detecting this variant of myasthenia gravis.
Neurodegenerative diseases of the central nervous system:
Alzheimer's Disease (AD) Alzheimer's disease (AD) is the most prevalent form of dementia among the elderly. The disease is characterized behaviorally by chronic and progressive decline in cognitive function, beginning with short-term memory loss, and neurologically by buildup of misfolded tau protein and associated neurofibrillary tangles, and by amyloid-beta senile plaques amyloid-beta senile plaques. Several genetic factors have been identified as contributing to AD, including mutations to the amyloid precursor protein (APP) and presenilins 1 and 2 genes, and familial inheritance of apolipoprotein E allele epsilon 4. In addition to these common factors, there are a number of other genes that have shown altered expression in Alzheimer's disease, some of which are associated with epigenetic factors.
Neurodegenerative diseases of the central nervous system:
Epigenetic factors ncRNA ncRNA that is encoded antisense from an intron within the beta-amyloid cleaving enzyme gene, BACE1, is involved in AD. This ncRNA, BACE1-AS (for antisense), which overlaps exon 6 of BACE1, is involved in increasing the stability of the BACE1 mRNA transcript. As that gene's name suggests, BACE1 is an enzymatic protein that cleaves the Amyloid Precursor Protein into the insoluble amyloid beta form, which then aggregates into senile plaques. With increased stability of BACE1 mRNA resulting from BACE1-AS, more BACE1 mRNA is available for translation into BACE1 protein.
Neurodegenerative diseases of the central nervous system:
miRNA factors have not consistently been shown to play a role in progression of AD. miRNAs are involved in post-transcriptional gene silencing via inhibiting translation or involvement in RNAi pathways. Some studies have shown upregulation of miRNA-146a, which differentially regulates neuroimmune-related Interleukin-1R associated kinases IRAK1 and IRAK2 expression, in human AD brain, while other studies have shown upregulation or downregulation of miRNA-9 in brain.
Neurodegenerative diseases of the central nervous system:
DNA methylation In Alzheimer's disease cases, global DNA hypomethylation and gene-specific hypermethylation has been observed, though findings have varied between studies, especially in studies of human brains. Hypothetically, global hypomethylation should be associated with global increases in transcription, since CpG islands are most prevalent in gene promoters; gene-specific hypermethylation, however, would indicate that these hypermethylated genes are repressed by the methylation marks. Generally, repressive hypermethylation of genes related to learning and memory has been observed in conjunction with derepressive hypomethylation of neuroinflammatory genes and genes related to pathological expression of Alzheimer's disease. Reduced methylation has been found in the long-term memory-associated temporal neocortex neurons in monozygotic twins with Alzheimer's disease compared to the healthy twin. Global hypomethylation of CpG dinucleotides has also been observed in hippocampus and in entorhinal cortex layer II of human AD patients, both of which are susceptible to AD pathology. These results, found by probing with immunoassays, have been challenged by studies that interrogate DNA sequence by bisulfite sequencing, a CpG transformation technique which is sensitive to CpG methylation status, in which global hypomethylation has been observed.
Neurodegenerative diseases of the central nervous system:
COX-2 At the individual gene level, hypomethylation and thus derepression of COX-2 occurs, inhibition of which reduces inflammation and pain, and hypermethylation of BDNF, a neurotrophic factor important for long-term memory. Expression of CREB, an activity-dependent transcription factor involved in regulating BDNF among many other genes, has also been shown to be hypermethylated, and thus repressed, in AD brains, further reducing BDNF transcription. Furthermore, synaptophysin (SYP), the major synaptic vesicle protein-encoding gene, has been shown to be hypermethylated and thus repressed, and transcription factor NF-κB, which is involved in immune signaling, has been shown to be hypomethylated and thus derepressed. Taken together, these results have elucidated a role for dysregulation of genes involved in learning and memory and synaptic transmission, as well as with immune response.
Neurodegenerative diseases of the central nervous system:
Hypomethylation has been observed in promoters of presenilin 1, GSK3beta, which phosphorylates tau protein, and BACE1, an enzyme that cleaves APP into the amyloid-beta form, which in turn aggregates into insoluble senile plaques. Repressive hypermethylation caused by amyloid-beta has been observed at the promoter of NEP, the gene for neprilysin, which is the major amyloid-beta clearing enzyme in the brain. This repression of NEP could result in a feed-forward buildup of senile plaques; combined with the observed increase in AD brains of BACE1-AS and corresponding increases in BACE1 protein and amyloid beta, multiple levels of epigenetic regulation may be involved in controlling amyloid-beta formation, clearance or aggregation, and senile plaque deposition. There may be some effect of age in levels of DNA methylation at specific gene promoters, as one study found greater levels of methylation at APP promoters in AD patients up to 70 years old, but lower levels of methylation in patients greater than 70 years old. Studies on differential DNA methylation in human AD brains remain largely inconclusive possibly owing to the high degree of variability between individuals and to the numerous combinations of factors that may lead to AD.
Neurodegenerative diseases of the central nervous system:
Histone marks Acetylation of lysine residues on histone tails is typically associated with transcriptional activation, whereas deacetylation is associated with transcriptional repression. There are few studies investigating specific histone marks in AD. These studies have elucidated a decrease in acetylation of lysines 18 and 23 on N-terminal tails of histone 3 (H3K18 and H3K23, respectively) and increases in HDAC2 in AD brains - both marks related to transcriptional repression. Age-related cognitive decline has been associated with deregulation of H4K12 acetylation, a cognitive effect that was restored in mice by induction of this mark.
Neurodegenerative diseases of the central nervous system:
Treatments Treatment for prevention or management of Alzheimer's disease has proven troublesome since the disease is chronic and progressive, and many epigenetic drugs act globally and not in a gene-specific manner. As with other potential treatments to prevent or ameliorate symptoms of AD, these therapies do not work to cure, but only ameliorate symptoms of the disease temporarily, underscoring the chronic, progressive nature of AD, and the variability of methylation in AD brains.
Neurodegenerative diseases of the central nervous system:
Folate and other B vitamins B vitamins are involved in the metabolic pathway that leads to SAM production. SAM is the donor of the methyl group utilized by DNA methyltransferases (DNMTs) to methylate CpGs. Using animal models, Fuso et al. have demonstrated restoration of methylation at previously hypomethylated promoters of presenilin 1, BACE1 and APP - a hypothetically stable epigenetic modification that should repress those genes and slow the progression of AD. Dietary SAM supplementation has also been shown to reduce oxidative stress and delay buildup of neurological hallmarks of AD such as amyloid beta and phosphorylated tau protein in transgenic AD mice.
Neurodegenerative diseases of the central nervous system:
AZA Khan and colleagues have demonstrated a potential role for neuroglobinin attenuating amyloid-related neurotoxicity. 5-aza-2' deoxycitidine (AZA, or decitabine), a DNMT inhibitor, has shown some evidence for regulating neuroglobin expression, though this finding has not been tested in AD models.
Neurodegenerative diseases of the central nervous system:
Histone-directed treatments Though studies of histone marks in AD brains are few in number, several studies have looked at the effects of HDACis in treatment of Alzheimer's disease. Class I and II HDAC inhibitors such as trichostatin A, vorinostat, and sodium butyrate, and Class III HDACis, such as nicotinamide, have been effective at treating symptoms in animal models of AD. While promising as a therapeutic in animal models, studies on the long-term efficacy of HDACis and human trials have yet to be conducted.
Neurodegenerative diseases of the central nervous system:
Sodium butyrate Sodium butyrate is a class I and II HDACi and has been shown to recover learning and memory after 4 weeks, decrease phosphorylated tau protein, and restore dendritic spine density in the hippocampus of AD transgenic mice. Histone acetylation resulting from diffuse sodium butyrate application is especially prevalent in the hippocampus, and genes involved in learning and memory showed increased acetylation in AD mice treated with this drug.
Neurodegenerative diseases of the central nervous system:
Trichostatin A Trichostatin A is also a class I and II HDACi that rescues fear learning in a fear conditioning paradigm in transgenic AD mice to wild type levels via acetylation on histone 4 lysine tails.
Vorinostat Vorinostat is a class I and II HDACi that has been shown to be especially effective at inhibiting HDAC2 and restoring memory functions in non-AD models of learning deficits. One study showed vorinostat is effective at reversing contextual memory deficits in transgenic AD mice.
Huntington's (HD) Huntington's disease (HD) is an inherited disorder that causes progressive degeneration of neurons within the cerebral cortex and striatum of the brain resulting in loss of motor functions (involuntary muscle contractions), decline in cognitive ability (eventually resulting in dementia), and changes in behavior.
Neurodegenerative diseases of the central nervous system:
Genetics and underlying causes Huntington's is caused by an autosomal dominant mutation expanding the number of glutamine codon repeats (CAG) within the Huntingtin gene (Htt). The Htt gene encodes for the huntingtin protein which plays a role in normal development but its exact function remains unknown. The length of this CAG repeat correlates with the age-of-onset of the disease. The average person without Huntington's has less than 36 CAG repeats present within the Htt gene. When this repeat length exceeds 36, the onset of neuronal degradation and the physical symptoms of Huntington's can range from as early as 5 years of age (CAG repeat > 70) to as late as 80 years of age (CAG repeat < 39).This CAG expansion results in mRNA downregulation of specific genes, decreased histone acetylation, and increased histone methylation. The exact mechanism of how this repeat causes gene dysregulation is unknown, but epigenome modification may play a role. For early-onset Huntington's (ages 5–15), both transgenic mice and mouse striatal cell lines show brain specific histone H3 hypoacetylation and decreased histone association at specific downregulated genes within the striatum (namely Bdnf, Cnr1, Drd2 - dopamine 2 receptor, and Penk1 - preproenkephalin). For both late- and early-onset Huntington's, the H3 and H4 core histones associated with these downregulated genes in Htt mutants have hypoacetylation (decreased acetylation) compared to wild-type Htt. This hypoacetylation is sufficient to cause tighter chromatin packing and mRNA downregulation.Along with H3 hypoacetylation, both human patients and mice with the mutant Htt have increased levels of histone H3 lysine 9 trimethylation. This increase in H3-K9 trimethylation is linked to an increased expression of the methyltransferase ESET/SETDB1 (ERG-associated protein with SET domain (ESET)), which targets and trimethylates H3-K9 residues. It is proposed that this hypermethylation may account for the onset of specific gene repression in Htt mutants.
Neurodegenerative diseases of the central nervous system:
HDAC inhibitors Huntington patients and both mouse and Drosophila models show histone H3 and H4 hypoacetylation. There are currently no treatments for the disease but numerous HDAC inhibitors have been tested and shown to reverse the certain symptoms caused by the Htt mutation.
Neurodegenerative diseases of the central nervous system:
Parkinson's Disease (PD) Parkinson's disease (PD) is characterized by progressive degeneration of dopaminergic neurons in the substantia nigra by causes unknown. Several genes and environmental factors (e.g. pesticide exposure) may play a role in onset of PD. Hallmarks include mutations to the alpha-synuclein gene, SNCA, as well as PARK2, PINK1, UCHL1, DJ1, and LRRK2 genes, and fibrillar accumulation of Lewy bodies from misfolded alpha-synuclein. Symptoms are most noticeably manifested in disorders of movement, including shaking, rigidity, deficits in making controlled movements, and slow and difficult walking. The late stages of the disease result in dementia and depression. Levodopa and dopaminergic therapy may ameliorate symptoms, though there is no treatment to halt progression of the disease.
Neurodegenerative diseases of the central nervous system:
Epigenetic factors ncRNA Reductions of miR-133b correlated to decreased numbers of dopaminergic neurons in the midbrain of PD patients. miR-132, meanwhile, is negatively correlated with dopaminergic neuron differentiation in the midbrain. miR-7 and miR-153 act to reduce alpha-synuclein levels (a hallmark of PD) but are reduced in PD brain.
Neurodegenerative diseases of the central nervous system:
DNA methylation Neurons of PD patients show hypomethylation of tumor necrosis factor (TNF) alpha encoding sequence, overexpression of which leads to apoptosis of neurons. Cerebrospinal fluid of PD patients also shows elevated TNF alpha. Research indicates there may be a link between DNA methylation and SNCA expression. Furthermore, human and mouse models have shown reduction of nuclear DNMT1 levels in PD subjects, resulting in hypomethylated states associated with transcriptional repression.
Neurodegenerative diseases of the central nervous system:
Histone marks alpha-synuclein, the protein encoded by SNCA, can associate with histones and prevent their acetylation in concert with the HDACs HDAC1 and Sirt2. Furthermore, it has been demonstrated that alpha-synuclein binds histone 3 and inhibits its acetylation in Drosophila. Dopamine depletion in Parkinson's disease is associated with repressive histone modifications, including reduced H3K4me3, and lower levels of H3 and H4 lysine acetylation after levodopa therapy (a common treatment of PD).
Neurodegenerative diseases of the central nervous system:
Treatments Epigenetic treatments tested in models of PD are few, though some promising research has been conducted. Most treatments investigated thus far are directed at histone modifications and analysis of their roles in mediating alpha-synuclein expression and activity. Pesticides and paraquat increase histone acetylation, producing neurotoxic effects similar to those seen in PD, such as apoptosis of dopaminergic cells. Despite this, treatment with HDACis seems to have a neuroprotective effect.
Neurodegenerative diseases of the central nervous system:
Multiple Sclerosis Multiple Sclerosis (MS) is a demyelinating neurodegenerative disease that does not have a confirmed cause, but is widely considered to be an autoimmune disease in nature. It is indicated by demyelination of the nerves of the brain and spinal cord. Its symptoms are unique in nature and vary, but include those that have degenerative effects in the eyes and limbs. These can present themselves as numbness or atrophy, shock like sensations, paralysis, as well as lack of coordination or tremors, within the extremities. Within the eye, multiple sclerosis can cause blurriness, double vision, pain, or vision loss. Multiple sclerosis effects can be presented throughout other realms of the body, but is largely characterized by these main symptoms. Some of these can include loss of sexual or excretory function and epilepsy. While there are a few subcategories of multiple sclerosis, in most instances, the disease afflicts in a relapsing nature, where relapses of symptoms might not occur for extended periods of time, yielding more to the uncertainty of the disease. There is no known cure for MS, but measures can be taken post relapse to regain loss of function and the symptoms can be mitigated via therapeutic or medicinal means.
Neurodegenerative diseases of the central nervous system:
Epigenetic Factors Because of the outside factors that precede multiple sclerosis and the heritability typically occurring within the mother, it is thought to have an epigenetic cause. Some factors that may increase the incidence of MS are smoking, vitamin deficiency, and a history of some viral infections—which are factors that can induce epigenetic change.
Neurodegenerative diseases of the central nervous system:
Human Leukocyte Antigen-DRB1*15 Allele Human leukocyte antigen-DRB1*15 haplotype is a potential risk factor of MS. Because of the increased likelihood of the mother's human leukocyte antigen-DRB1*15 allele being passed onto their children, this contributes to the instances of MS being more prevalent from the mother. HLA-DRB1 is thought to be regulated via epigenetic means. The correlation of MS and this allele is speculated to be due to the presence of hypomethylation in the CpG island of HLA-DRB1, and those that carry the allele tend to exhibit this hypomethylation. HLA-DRB1 exon 2 is a particular region where evidence has shown that methylation is shown to be important in regulation. Research has furthered the evidence that variation in HLA-DRB1 DMR, which is a mechanism that is methylation regulated, that in turn regulates increased HLA-DRB1 expression, displays an increased risk for MS, and the exhibition of the disease.
Neurodegenerative diseases of the central nervous system:
miRNA Higher levels of expression of specific types of miRNA are often seen in the brain of those afflicted, showing an association of these types of miRNA and MS. Higher expression of miR-155 and miR-326 is often associated with CD4+T cell differentiation, and with this differentiation, instances of autoimmune encephalitis occur, which is the link with which it is thought that smoking can induce epigenetic changes that increase susceptibility to MS. Higher expression levels of miR-18b, miR-493, miR-599, and miR-96 are often seen in patients diagnosed with MS. miR-145 detection appears to be a promising future diagnostic tool due to its high specificity of 90% and sensitivity of 89.5% in whole blood testing due to its capability of distinguishing healthy patients versus those with MS. A symptom associated with MS patients is white matter lesions in the brain, and these lesions when biopsied showed higher expression of miR-155, miR-326 and miR-34a. These are especially notable due to the fact that overexpression of these miRNA's cause downregulation of CD47, leading to myelin phagocytosis, because of CD47's role of inhibiting macrophage activity.
Neurodegenerative diseases of the central nervous system:
DNA Methylation MS patients can be identified through observation of abnormal DNA methylation patterns in genes responsible for inflammation and myelination factor expression. Methylation occurs in the genomic region, CpG island, and is imperative in regulation of transcription. A methylated CpG region typically is the mechanism that will silence a gene, whereas a hypomethylated region is able to induce transcription. Using methylation inhibitors it has been shown that allowing higher proliferation of T cells can be achieved by preventing silencing. Abnormalities in methylation patterns increase the generation of CD4+T auto reactive. Hypomethylation of CpG regions of the PAD2 gene, a regulator of MBP which in turn regulates myelin, is also associated with higher instances of MS. This hypomethylation leads to overexpression of the PAD2 gene. These patterns have been observed in the white matter of patients with MS. While methylation is an indicator of MS, its effects are more specialized to location in MS, for example, where these patterns are observed in white matter.
Neurodegenerative diseases of the central nervous system:
Histone Modifications Association of abnormal histone modification in MS patients can be found in lesions located in the brain, with most instances of this being observed in patients over time and in lesions located in the frontal lobe. Higher instance of histone acetylation can be seen in patients afflicted over time, but this is counteracted by lower instances of histone acetylation in lesions found on the brain early in the course of the disease. The mechanisms by which histone modifications work in the progression of MS are unconfirmed, but changes in acetylation are often associated with the disease.
Neurodegenerative diseases of the central nervous system:
Treatments HDAC Inhibitors Trichostatin Positive responses were observed in animal trials utilizing this HDAC inhibitor, associated with mediation of inflammatory pathways and thus resulting in lower instances of inflammatory responses in the brain. It was also shown to be effective in decreasing levels of disability when the mice were in a relapsing stage of MS. Trichostatin's mediation of symptoms is not well known but is thought to work in increasing acetylation at the H3 and H4 histones in CD4+T cells where MS patients often display differences in acetylation levels at these histones that control patients do not.
Neurodegenerative diseases of the central nervous system:
Vorinostat Animal trials were utilized along with the testing of human myeloid dendritic cells. Not much is known about the mechanisms of Vorinostat, however regulation of Th1/Th17 cytokine expression, which are responsible for inducing inflammation, were observed, thereby decreasing instances of inflammation and demyelination. Decreased patterns of T cell proliferation were also observed, similar to how Trichostatin mediates disease symptoms.Valpropic Acid Valpropic acid has been shown to have positive results in animal trials, in the mitigation of the disease by regulating the severity and duration of MS. Its mechanism is decreasing the presentation of miRNA. Its mechanism for such has been observed in rats by shifting Th1 and Th17 to Th2 (responsible for inducing inflammation), thereby downregulating miRNA expression in inflammatory cytokines, tumor mediating mechanisms, and the spine. This is another instance in which T cell expression regulation is present, by preventing proliferation through interference of its pathway, similar to Trichostatin and Vorinostat. Another effect of VPA is its prevention of macrophage and lymphocyte proliferation in the spinal cords of MS rats. Currently, no HDAC inhibitors are in use for the mitigation of symptoms in MS patients however, some are in pre-clinical trials at this time. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Quasielastic neutron scattering**
Quasielastic neutron scattering:
Quasielastic neutron scattering (QENS) designates a limiting case of inelastic neutron scattering, characterized by energy transfers being small compared to the incident energy of the scattered particles. In a more strict meaning, it denotes scattering processes where dynamics in the sample (such as diffusive dynamics) lead to a broadening of the incident neutron spectrum, in contrast to, e.g., the scattering from a diffusionless crystal, where the scattered neutron energy spectrum consists of an elastic line (corresponding to no energy transfer with the sample) and a number of well-separated inelastic lines due to the creation or annihilation of phonons with specific energies.
Quasielastic neutron scattering:
The term quasielastic scattering was originally coined in nuclear physics. It was applied to thermal neutron scattering since the early 1960s, notably in an article by Leon van Hove and in a highly cited one by Pierre Gilles de Gennes.QENS is typically investigated on high-resolution spectrometers (neutron backscattering, neutron time-of-flight scattering, neutron spin echo).
It is used to investigate topics like solid-state diffusion (e.g. hydrogen in metals) slow modes in crystals (e.g. methyl group rotation) relaxation of viscous liquids
Conference Series:
Starting in 1992, there is a conference series entitled QENS. Since 2012, it is being held together with the Workshop on Inelastic Neutron Spectrometry (WINS).
Textbooks:
M. Beé, Quasielastic Neutron Scattering, Adam Hilger: Bristol (1988).
R. Hempelmann, Quasielastic Neutron Scattering and Solid State Diffusion, Clarendon Press: Oxford (2000). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**1,4-Diazacycloheptane**
1,4-Diazacycloheptane:
1,4-Diazacycloheptane is an organic compound with the formula (CH2)5(NH)2. This cyclic diamine is a colorless oily liquid that is soluble in polar solvents. It is studied as a chelating ligand. The N-H centers can be replaced with many other groups.It has known use in piperazine pharmaceuticals, for example: Fasudil Bunazosin Homochlorcyclizine Homopipramol | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**ML-154**
ML-154:
ML-154 (NCGC-84) is a drug which acts as a selective, non-peptide antagonist at the neuropeptide S receptor NPSR. In animal studies it decreases self-administration of alcohol in addicted rats, and lowers motivation for alcohol rewards, suggesting a potential application for NPS antagonists in the treatment of alcoholism. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Target controlled infusion**
Target controlled infusion:
Target-controlled infusion (TCI) automates the dosing of intravenous drugs during surgery. After the anesthetist sets the desired parameters in a computer and presses the start button, the system controls the infusion pump, while being monitored by the anesthetist. TCI is as safe and effective as manually controlled infusion.
Target controlled infusion:
TCI can be sub-classified according to the target. The suffix 'e' as in TCIe indicates that the target is the effect site, in most cases, the central nervous system or brain. Alternatively, the suffix 'p' denotes plasma, indicating that the device implementing the TCI model is to target the blood plasma. There are important differences in relation to the time taken for effect site equilibration. Studies have demonstrated the clinical safety of the effect-site target model.Popular TCI models exist for Propofol and the synthetic opioid Remifentanil. The models are based on pharmacokinetic studies and use software embedded in the infusion device. For propofol the Marsh and Schnider models are available and the Minto model is commonly used for remifentanil. In 2017, a project to emulate the TCI models in the python language was published on GitHub.
History:
TCI has been used in clinical settings since 1996, initially with propofol. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Pu pu platter**
Pu pu platter:
A pu pu platter is a tray of American Chinese or Hawaiian food consisting of an assortment of small meat and seafood appetizers. The Thrillist called the pu-pu platter "an amalgam of Americanized Chinese food, Hawaiian tradition and bar food."The pupu platter was probably first introduced to restaurants on the United States mainland by Donn Beach in 1934. It has since become a standard at most Polynesian-themed restaurants such as Don's and Trader Vic's. The earliest known print reference to a pupu platter served at a Chinese restaurant is from 1969. Later, other types of restaurants used "pu pu platter" to describe an appetizer combination platter.However, pu pu platters are currently more closely associated with American Chinese restaurants. A typical pu pu platter, as found in American Chinese cuisine, includes appetizers such as egg rolls, spare ribs, chicken wings, chicken fingers, beef teriyaki, skewered beef, fried wontons, fried shrimp, or crab rangoons.
Hawaiian origin and etymology:
In the Hawaiian language, pū-pū denotes a relish, appetizer, canapé, or hors d'oeuvre; it originally meant "shell fish', but also referred to small bits of fish, chicken, or banana relish served with kava and beans.
In Hawaiian cuisine:
Since the introduction of commercial dining and drinking establishments in Hawaii, pūpū were, and remain, standard fare in island establishments. An establishment that serves "heavy pupus" will often have a buffet table with warming trays or warming tables full of chicken, tempura vegetables, shrimp, poke (cubed and seasoned raw fish), small skewers of teriyaki meat or chicken, sushi, and other similar finger foods. An establishment that serves "light pupus" usually will offer only the cold foods such as poke, sushi, and vegetables. Some establishments will serve pūpū to the table.
In Hawaiian cuisine:
At Hawaiian bars, restaurants, catered events such as political rallies, and private parties, establishments and hosts are known in "local" circles by the quality of their pupus. Event invitations often will state that "light pupus" or "heavy pupus" will be served so that attendees will know whether they should plan to have a full meal before the event or not.
In Polynesian cuisine on the mainland:
At the height of the tiki bar craze during the late 1950s and early 1960s, the New York Herald Tribune published several articles concerning the opening and the ambiance of one of the first Hawaiian-themed restaurants in New York City, Luau 400, on East 57th Street. At the time of the restaurant's opening in 1957, pu pu platters were considered a part of the luau feast. A typical platter at this establishment would have included baked clams, rumaki, Shrimp Vela (battered fried shrimp with coconut), chicken wings, egg rolls, spare ribs, or Javanese sate (satay) on skewers. The appetizers were served on "a Lazy Susan made of monkey pod wood and equipped with a little stove fired with charcoal briquettes." Recipes for some of the pu pu items were later published in the Herald Tribune in 1960.Always the showman, Trader Vic included a hibachi grill when presenting a pu pu platter at the table. Others say that the idea could have come from Donn Beach. No one can agree, but everyone else appeared to have copied the idea.
In Polynesian cuisine on the mainland:
By the twenty-first century, the tiki bars and the flaming pu pu platter had become a dying art. Some tiki bar aficionados have created lists of tiki bars in the United States in which a flaming pu pu can still be found.At one 21st-century tiki bar, the pu pu platter includes "Samoan deviled eggs, Chinese sausage and stick[y] rice arancini, coconut shrimp and chilies stuffed with pork sausage." As bar food, a pu pu platter at a 21st-century New York City brasserie could include French escargot, grilled cubed tropical fruits (such as pineapple), fried pierogies or American-style barbecued ribs and wings.
In Italian restaurants:
Italian restaurants in New England may offer "Italian pu pu platters". Depending on the establishment, the platters may contain only appetizers, such as mozzarella sticks, meatballs, sausages, lasagna sticks, and calamari; or they may contain small portions of different pasta dishes, such as spaghetti, lasagna, manicotti, and ravioli. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Burgee**
Burgee:
A burgee is a distinguishing flag, regardless of its shape, of a recreational boating organization. In most cases, they have the shape of a pennant.
Etiquette:
Yacht clubs and their members may fly their club's burgee while under way and at anchor, day or night. Sailing vessels may fly the burgee either from the main masthead or from a halyard under the lowermost starboard spreader. Most powerboats (i.e. those lacking any mast or having a single mast) fly the burgee off a short staff at the bow; two-masted power vessels fly the burgee at the foremast.
Flag officers:
The officers of a yacht club may fly various burgees appropriate to their rank: for example, the commodore may fly a swallow-tailed version of the club burgee (and the vice- and rear-commodores the same, but distinguished by the addition of one or two balls respectively at the canton). A past-commodore may also be given a distinctively-shaped flag. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Virtual directory**
Virtual directory:
In computing, the term virtual directory has a couple of meanings. It may simply designate (for example in IIS) a folder which appears in a path but which is not actually a subfolder of the preceding folder in the path. However, this article will discuss the term in the context of directory services and identity management.
Virtual directory:
A virtual directory or virtual directory server (VDS) in this context is a software layer that delivers a single access point for identity management applications and service platforms. A virtual directory operates as a high-performance, lightweight abstraction layer that resides between client applications and disparate types of identity-data repositories, such as proprietary and standard directories, databases, web services, and applications.
Virtual directory:
A virtual directory receives queries and directs them to the appropriate data sources by abstracting and virtualizing data. The virtual directory integrates identity data from multiple heterogeneous data stores and presents it as though it were coming from one source. This ability to reach into disparate repositories makes virtual directory technology ideal for consolidating data stored in a distributed environment. As of 2011, virtual directory servers most commonly use the LDAP protocol, but more sophisticated virtual directories can also support SQL as well as DSML and SPML.
Virtual directory:
Industry experts have heralded the importance of the virtual directory in modernizing the identity infrastructure. According to Dave Kearns of Network World, "Virtualization is hot and a virtual directory is the building block, or foundation, you should be looking at for your next identity management project." In addition, Gartner analyst, Bob Blakley said that virtual directories are playing an increasingly vital role. In his report, “The Emerging Architecture of Identity Management,” Blakley wrote: “In the first phase, production of identities will be separated from consumption of identities through the introduction of a virtual directory interface.”
Capabilities:
Virtual directories can have some or all of the following capabilities: Aggregate identity data across sources to create a single point of access.
Create high-availability for authoritative data stores.
Act as identity firewall by preventing denial-of-service attacks on the primary data stores through an additional virtual layer.
Support a common searchable namespace for centralized authentication.
Present a unified virtual view of user information stored across multiple systems.
Delegate authentication to backend sources through source-specific security means.
Virtualize data sources to support migration from legacy data stores without modifying the applications that rely on them.
Enrich identities with attributes pulled from multiple data stores, based on a link between user entries.Some advanced identity virtualization platforms can also: Enable application-specific, customized views of identity data without violating internal or external regulations governing identity data. Reveal contextual relationships between objects through hierarchical directory structures.
Develop advanced correlation across diverse sources using correlation rules.
Build a global user identity by correlating unique user accounts across various data stores, and enrich identities with attributes pulled from multiple data stores, based on a link between user entries.
Enable constant data refresh for real-time updates through a persistent cache.
Advantages:
Virtual directories: Enable faster deployment because users do not need to add and sync additional application-specific data sources Leverage existing identity infrastructure and security investments to deploy new services Deliver high availability of data sources Provide application-specific views of identity data which can help avoid the need to develop a master enterprise schema Allow a single view of identity data without violating internal or external regulations governing identity data Act as identity firewalls by preventing denial-of-service attacks on the primary data-stores and providing further security on access to sensitive data Can reflect changes made to authoritative sources in real-time Leverages existing update processes of authoritative sources, so no separate (sometimes manual) process to update a central directory is needed Present a unified virtual view of user information from multiple systems so that it appears to reside in a single system Can secure all backend storage locations with a single security policy
Disadvantages:
An original disadvantage is public perception of "push & pull technologies" which is the general classification of "virtual directories" depending on the nature of their deployment. Virtual directories were initially designed and later deployed with "push technologies" in mind, which also contravened with privacy laws of the United States. This is no longer the case. There are, however, other disadvantages in the current technologies.
Disadvantages:
The classical virtual directory based on proxy cannot modify underlying data structures or create new views based on the relationships of data from across multiple systems. So if an application requires a different structure, such as a flattened list of identities, or a deeper hierarchy for delegated administration, a virtual directory is limited.
Many virtual directories cannot correlate same-users across multiple diverse sources in the case of duplicate users Virtual directories without advanced caching technologies cannot scale to heterogeneous, high-volume environments.
Sample terminology:
Unify metadata: Extract schemas from the local data source, map them to a common format, and link the same identities from different data silos based on a unique identifier.
Namespace joining: Create a single large directory by bringing multiple directories together at the namespace level. For instance, if one directory has the namespace "ou=internal,dc=domain,dc=com" and a second directory has the namespace "ou=external,dc=domain,dc=com," then creating a virtual directory with both namespaces is an example of namespace joining.
Identity joining: Enrich identities with attributes pulled from multiple data stores, based on a link between user entries. For instance if the user joeuser exists in a directory as "cn=joeuser,ou=users" and in a database with a username of "joeuser" then the "joeuser" identity can be constructed from both the directory and the database.
Data remapping: The translation of data inside of the virtual directory. For instance, mapping “uid” to “samaccountname,” so a client application that only supports a standard LDAP-compliant data source is able to search an Active Directory namespace, as well.
Query routing: Route requests based on certain criteria, such as “write operations going to a master, while read operations are forwarded to replicas.” Identity routing: Virtual directories may support the routing of requests based on certain criteria (such as write operations going to a master while read operations being forwarded to replicas).
Authoritative source: A "virtualized" data repository, such as a directory or database, that the virtual directory can trust for user data.
Sample terminology:
Server groups: Group one or more servers containing the same data and functionality. A typical implementation is the multi-master, multi-replica environment in which replicas process "read" requests and are in one server group, while masters process "write" requests and are in another, so that servers are grouped by their response to external stimuli, even though all share the same data.
Use cases:
The following are sample use cases of virtual directories: Integrating multiple directory namespaces to create a central enterprise directory.
Supporting infrastructure integrations after mergers and acquisitions.
Centralizing identity storage across the infrastructure, making identity information available to applications through various protocols (including LDAP, JDBC, and web services).
Creating a single access point for web access management (WAM) tools.
Enabling web single sign-on (SSO) across varied sources or domains.
Supporting role-based, fine-grained authorization policies Enabling authentication across different security domains using each domain’s specific credential checking method.
Improving secure access to information both inside and outside of the firewall. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Ice–albedo feedback**
Ice–albedo feedback:
Ice–albedo feedback is a positive feedback climate process where a change in the area of ice caps, glaciers, and sea ice alters the albedo and surface temperature of a planet. Ice is very reflective, therefore it reflects far more solar energy back to space than the other types of land area or open water. Ice–albedo feedback plays an important role in global climate change. For instance, at higher latitudes, warmer temperatures melt the ice sheets. However, if warm temperatures decrease the ice cover and the area is replaced by water or land, the albedo would decrease. This increases the amount of solar energy absorbed, leading to more warming. The change in albedo acts to reinforce the initial alteration in ice area leading to more warming. Warming tends to decrease ice cover and hence decrease the albedo, increasing the amount of solar energy absorbed and leading to more warming. In the geologically recent past, the ice–albedo positive feedback has played a major role in the advances and retreats of the Pleistocene (~2.6 Ma to ~10 ka ago) ice sheets. Inversely, cooler temperatures increase ice, which increases albedo, leading to more cooling.
Significance:
Current Snow– and ice–albedo feedback have a substantial effect on regional temperatures. In particular, the presence of ice cover makes the North Pole and the South Pole colder than they would have been without it. Consequently, recent Arctic sea ice decline is one of the primary factors behind the Arctic warming nearly four times faster than the global average since 1979 (the year when continuous satellite readings of the Arctic sea ice began)., in a phenomenon known as Arctic amplification. Modelling studies show that strong Arctic amplification only occurs during the months when significant sea ice loss occurs, and that it largely disappears when the simulated ice cover is held fixed. Conversely, the high stability of ice cover in Antarctica, where the thickness of the East Antarctic ice sheet allows it to rise nearly 4 km above the sea level, means that this continent has not experienced any net warming over the past seven decades: ice loss in the Antarctic and its contribution to sea level rise is instead driven entirely by the warming of the Southern Ocean, which had absorbed 35–43% of the total heat taken up by all oceans between 1970 and 2017.Ice–albedo feedback also has a smaller, but still notable effect on the global temperatures. Arctic ice decline between 1979 and 2011 is estimated to have been responsible for 0.21 watts per square meter (W/m2) of radiative forcing, which is equivalent to a quarter of radiative forcing from CO2 increases over the same period. When compared to cumulative increases in greenhouse gas radiative forcing since the start of the Industrial Revolution, it is equivalent to the estimated 2019 radiative forcing from nitrous oxide (0.21 W/m2), nearly half of 2019 radiative forcing from methane (0.54 W/m2) and 10% of the cumulative CO2 increase (2.16 W/m2).
Significance:
Future The impact of ice-albedo feedback on temperature will intensify in the future as the Arctic sea ice decline is projected to become more pronounced, with a likely near-complete loss of sea ice cover (falling below 1 million km2) at the end of the Arctic summer in September at least once before 2050 under all climate change scenarios, and around 2025 under the scenario of continually accelerating greenhouse gas emissions. Since September marks the end of the Arctic summer, it also represents the nadir of sea ice cover in the present climate, with an annual recovery process beginning in the Arctic winter. Consecutive ice-free Septembers are considered highly unlikely in the near future, but their frequency will increase with greater levels of global warming: a 2018 paper estimated that an ice-free September would occur once in every 40 years under a warming of 1.5 °C (2.7 °F), but once in every 8 years under 2 °C (3.6 °F) and once in every 1.5 years under 3 °C (5.4 °F). This means that the loss of Arctic sea ice during September or earlier in the summer would not be irreversible, and in the scenarios where global warming begins to reverse, its annual frequency would begin to go down as well. As such, it is not considered one of the tipping points in the climate system.
Significance:
Notably, while the loss of sea ice cover in September would be a historic event with significant implications for Arctic wildlife like polar bears, its impact on the ice-albedo feedback is relatively limited, as the total amount of solar energy received by the Arctic in September is already very low. On the other hand, even a relatively small reduction in June sea ice extent would have a far greater effect, since June represents the peak of the Arctic summer and the most intense transfer of solar energy. CMIP5 models estimate that a total loss of Arctic sea ice cover from June to September would increase the global temperatures by 0.19 °C (0.34 °F), with a range of 0.16–0.21 °C, while the regional temperatures would increase by over 1.5 °C (2.7 °F). This estimate includes not just the ice-albedo feedback itself, but also its second-order effects such the impact of such sea ice loss on lapse rate feedback, the changes in water vapor concentrations and regional cloud feedbacks. Since these calculations are already part of every CMIP5 and CMIP6 model, they are also included in their warming projections under every climate change pathway, and do not represent a source of "additional" warming on top of their existing projections.
Significance:
Very high levels of global warming could prevent Arctic sea ice from reforming during the Arctic winter. Unlike an ice-free summer, this ice-free Arctic winter may represent an irreversible tipping point. It is most likely to occur at around 6.3 °C (11.3 °F), though it could potentially occur as early as 4.5 °C (8.1 °F) or as late as 8.7 °C (15.7 °F). While the Arctic sea ice would be gone for an entire year, it would only have an impact on the ice-albedo feedback during the months where sunlight is received by the Arctic - i.e. from March to September. The difference between this total loss of sea ice and its 1979 state is equivalent to a trillion tons of CO2 emissions - around 40% of the 2.39 trillion tons of cumulative emissions between 1850 and 2019, although around a quarter of this impact has already happened with the current sea ice loss. Relative to now, an ice-free winter would have a global warming impact of 0.6 °C (1.1 °F), with a regional warming between 0.6 °C (1.1 °F) and 1.2 °C (2.2 °F).
Significance:
Ice–albedo feedback also exists with the other large ice masses on the Earth's surface, such as mountain glaciers, Greenland ice sheet, West Antarctic and East Antarctic ice sheet. However, their large-scale melt is expected to take centuries or even millennia, and any loss in area between now and 2100 will be negligible. Thus, climate change models do not include them in their projections of 21st century climate change: experiments where they model their disappearance indicate that the total loss of the Greenland Ice Sheet adds 0.13 °C (0.23 °F) to global warming (with a range of 0.04–0.06 °C), while the loss of the West Antarctic Ice Sheet adds 0.05 °C (0.090 °F) (0.04–0.06 °C), and the loss of mountain glaciers adds 0.08 °C (0.14 °F) (0.07–0.09 °C). Since the East Antarctic ice sheet would not be at risk of complete disappearance until the very high global warming of 5–10 °C (9.0–18.0 °F) is reached, and since its total melting is expected to take a minimum of 10,000 years to disappear entirely even then, it is rarely considered in such assessments. If it does happen, the maximum impact on global temperature is expected to be around 0.06 °C (0.11 °F). Total loss of the Greenland ice sheet would increase regional temperatures in the Arctic by between 0.5 °C (0.90 °F) and 3 °C (5.4 °F), while the regional temperature in Antarctica is likely to go up by 1 °C (1.8 °F) after the loss of the West Antarctic ice sheet and 2 °C (3.6 °F) after the loss of the East Antarctic ice sheet.
Significance:
Snowball Earth The runaway ice–albedo feedback was also important for the Snowball Earth. Geological evidence show glaciers near the equator, and models have suggested the ice–albedo feedback played a role. As more ice formed, more of the incoming solar radiation was reflected back into space, causing temperatures on Earth to drop. Whether the Earth was a complete solid snowball (completely frozen over), or a slush ball with a thin equatorial band of water still remains debated, but the ice–albedo feedback mechanism remains important for both cases.
Ice–albedo feedback on exoplanets:
On Earth, the climate is heavily influenced by interactions with solar radiation and feedback processes. One might expect exoplanets around other stars to also experience feedback processes caused by stellar radiation that affect the climate of the world. In modeling the climates of other planets, studies have shown that the ice–albedo feedback is much stronger on terrestrial planets that are orbiting stars (see: stellar classification) that have a high near-ultraviolet radiation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Quillen's theorems A and B**
Quillen's theorems A and B:
In topology, a branch of mathematics, Quillen's Theorem A gives a sufficient condition for the classifying spaces of two categories to be homotopy equivalent. Quillen's Theorem B gives a sufficient condition for a square consisting of classifying spaces of categories to be homotopy Cartesian. The two theorems play central roles in Quillen's Q-construction in algebraic K-theory and are named after Daniel Quillen.
Quillen's theorems A and B:
The precise statements of the theorems are as follows.
In general, the homotopy fiber of Bf:BC→BD is not naturally the classifying space of a category: there is no natural category Ff such that FBf=BFf . Theorem B constructs Ff in a case when f is especially nice. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**6162 aluminium alloy**
6162 aluminium alloy:
6162 aluminium alloy is an alloy in the wrought aluminium-magnesium-silicon family (6000 or 6xxx series). It is related to 6262 aluminium alloy in that Aluminum Association designations that only differ in the second digit are variations on the same alloy. It is similar to 6105 aluminium alloy, both in alloy composition and the fact that it is only really used in extrusions. However, as a wrought alloy, it can also be formed by rolling, forging, and similar processes, should the need arise. It is supplied in heat treated form. It can be referred to by the UNS designation A96162, and is covered by the standard ASTM B221: Standard Specification for Aluminum and Aluminum-Alloy Extruded Bars, Rods, Wire, Profiles, and Tubes.
Chemical composition:
The alloy composition of 6162 aluminium is: Aluminium: 96.7 to 98.9% Chromium: 0.1% max Copper: 0.2% max Iron: 0.5% max Magnesium: 0.7 to 1.1% Manganese: 0.1% max Silicon: 0.4 to 0.8% Titanium: 0.1% max Zinc: 0.25% max Residuals: 0.15% max
Properties:
Typical material properties for 6162 aluminum alloy include: Density: 2.70 g/cm3, or 169 lb/ft3.
Young's modulus: 70 GPa, or 10 Msi.
Ultimate tensile strength: 280 to 290 MPa, or 41 to 42 ksi.
Yield strength: 260 to 270 MPa, or 38 to 39 ksi.
Thermal Expansion: 21.9 μm/m-K. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Propylene oxide**
Propylene oxide:
Propylene oxide is an acutely toxic and carcinogenic organic compound with the molecular formula CH3CHCH2O. This colourless volatile liquid with an odour similar to ether, is produced on a large scale industrially. Its major application is its use for the production of polyether polyols for use in making polyurethane plastics. It is a chiral epoxide, although it is commonly used as a racemic mixture.
Propylene oxide:
This compound is sometimes called 1,2-propylene oxide to distinguish it from its isomer 1,3-propylene oxide, better known as oxetane.
Production:
Industrial production of propylene oxide starts from propylene. Two general approaches are employed, one involving hydrochlorination and the other involving oxidation. In 2005, about half of the world production was through chlorohydrin technology and one half via oxidation routes. The latter approach is growing in importance.
Hydrochlorination route The traditional route proceeds via the conversion of propene to propylene chlorohydrin according to the following simplified scheme: The mixture of 1-chloro-2-propanol and 2-chloro-1-propanol is then dehydrochlorinated. For example: Lime (calcium hydroxide) is often used to absorb the HCl.
Production:
Oxidation of propylene The other general route to propylene oxide involves oxidation of propylene with an organic peroxide. The reaction follows this stoichiometry: CH3CH=CH2 + RO2H → CH3CHCH2O + ROHThe process is practiced with four hydroperoxides: In the Halcon process, t-Butyl hydroperoxide derived from oxygenation of isobutane, which affords t-butanol. This coproduct can be dehydrated to isobutene, converted to MTBE, an additive for gasoline.
Production:
Ethylbenzene hydroperoxide, derived from oxygenation of ethylbenzene, which affords 1-phenylethanol. This coproduct can be dehydrated to give styrene, a useful monomer.
Cumene hydroperoxide derived from oxygenation of cumene (isopropylbenzene), which affords cumyl alcohol. Via dehydration and hydrogenation this coproduct can be recycled back to cumene. This technology was commercialized by Sumitomo Chemical.
Hydrogen peroxide is the oxidant in the hydrogen peroxide to propylene oxide (HPPO) process, catalyzed by a titanium-doped silicalite: C3H6 + H2O2 → C3H6O + H2OIn principle, this process produces only water as a side product. In practice, some ring-opened derivatives of PO are generated.
Reactions:
Like other epoxides, PO undergoes ring-opening reactions. With water, propylene glycol is produced. With alcohols, reactions, called hydroxylpropylation, analogous to ethoxylation occur. Grignard reagents add to propylene oxide to give secondary alcohols.
Some other reactions of propylene oxide include: Reaction with aluminium oxide at 250–260 °C leads to propionaldehyde and a little acetone.
Reaction with silver(I) oxide leads to acetic acid.
Reaction with sodium–mercury amalgam and water leads to isopropanol.
Uses:
Between 60 and 70% of all propylene oxide is converted to polyether polyols by the process called alkoxylation. These polyols are building blocks in the production of polyurethane plastics. About 20% of propylene oxide is hydrolyzed into propylene glycol, via a process which is accelerated by acid or base catalysis. Other major products are polypropylene glycol, propylene glycol ethers, and propylene carbonate.
Uses:
Niche uses Fumigant The United States Food and Drug Administration has approved the use of propylene oxide to pasteurize raw almonds beginning on September 1, 2007, in response to two incidents of contamination by Salmonella in commercial orchards, one incident occurring in Canada and one in the United States.
Pistachio nuts can also be subjected to propylene oxide to control Salmonella.
Microscopy Propylene oxide is commonly used in the preparation of biological samples for electron microscopy, to remove residual ethanol previously used for dehydration. In a typical procedure, the sample is first immersed in a mixture of equal volumes of ethanol and propylene oxide for 5 minutes, and then four times in pure oxide, 10 minutes each.
Munition Propylene oxide is sometimes used in thermobaric munitions as the fuel in fuel–air explosives. In addition to the explosive damage from the blast wave, unexploded propylene oxide can cause additional effects from direct toxicity.
Safety:
Propylene oxide is both acutely toxic and carcinogenic. Acute exposure causes respiratory tract irritation, eventually leading to death . Signs of toxicity after acute exposure include salivation, lacrimation, nasal discharge, gasping, lethargy and hypoactivity, weakness, and incoordination. Propylene oxide is also neurotoxic in rats, and presumably in humans Propylene oxide alkylates DNA. As such, it is known animal carcinogen and a potential human carcinogen, and is included into the List of IARC Group 2B carcinogens.
Natural occurrence:
In 2016 it was reported that propylene oxide was detected in Sagittarius B2, a cloud of gas in the Milky Way weighing three million solar masses. It is the first chiral molecule to be detected in space, albeit with no enantiomeric excess.
Cited sources:
Haynes WM, ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. ISBN 1-4398-5511-0. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Epic Systems**
Epic Systems:
Epic Systems Corporation, or Epic, is an American privately held healthcare software company. According to the company, hospitals that use its software held medical records of 78% of patients in the United States and over 3% of patients worldwide in 2022.
History:
Epic was founded in 1979 by Judith R. Faulkner with a $70,000 investment (equivalent to $280,000 in 2022). Originally headquartered in Madison, Wisconsin, Epic moved its headquarters to a large campus in the suburb of Verona, Wisconsin in 2005, where it employs 10,000 people as of 2019. The campus has themed areas/buildings, such as a castle-like structure, a "Wizard Campus" that appears to be inspired by J.K. Rowling's Harry Potter, and a dining facility designed to mimic a train station.As of 2015, the company was in the fifth phase of campus expansion with five new buildings each planned to be around 100,000 square feet. The company also has offices in Bristol, UK; 's-Hertogenbosch, Netherlands; Dubai, United Arab Emirates; Dhahran, Saudi Arabia; Helsinki, Finland; Melbourne, Australia; Singapore; Trondheim, Norway; and Søborg, Denmark.
Product and market:
Epic primarily develops, manufactures, licenses, supports, and sells a proprietary electronic medical record software application, known in whole as 'Epic' or an Epic EMR. The company's healthcare software is centered on its Chronicles database management system. Epic's applications support functions related to patient care, including registration and scheduling; clinical systems for doctors, nurses, emergency personnel, and other care providers; systems for lab technologists, pharmacists, and radiologists; and billing systems for insurers. MyChart is used in the USA and other countries to access doctors’ records and for billing purposes. It is used by 150 million patients across the US.Epic also offers cloud hosting for customers that do not wish to maintain their own servers; and short-term optimization and implementation consultants through their wholly-owned subsidiary Boost, Inc.The company's competitors include Cerner, MEDITECH, Allscripts, athenahealth, and units of IBM, McKesson, and Siemens.The majority of U.S. News & World Report's top-ranked hospitals and medical schools use Epic. In 2003, Kaiser Permanente began using Epic for its electronic records system. Among many others, Epic provides electronic record systems for Cedars-Sinai Medical Center in Los Angeles, the Cleveland Clinic, Johns Hopkins Hospital, UC Davis Medical Center in Sacramento, and all Mayo Clinic campuses. Partners HealthCare began adopting Epic in 2015 in a project initially reported to cost $1.2 billion, which critics decried and which is greater than the cost of its buildings. By 2018, the total expenses for the project were $1.6 billion, with payments for the software itself amounting to less than $100 million and the majority of the costs caused by lost patient revenues, tech support and other implementation work.In 2022 Emory Healthcare, Baptist Health and Memorial Hermann Health System all switched to Epic from Cerner.
Criticisms and controversies:
Data sharing Care Everywhere is Epic's health information exchange software, which comes with its electronic health record (EHR, or EMR) system. A 2014 article in The New York Times interviews two doctors who said that their Epic systems wouldn't allow them to share data with users of competitors' software in a way that will satisfy the Meaningful Use requirements of the HITECH Act. At first, Epic charged a fee to send data to some non-Epic systems. Epic said the yearly cost for an average-sized hospital was around $5,000 a year. However, after Congressional hearings, Epic and other major software vendors announced that they would suspend per-transaction sharing fees. Epic customers must still pay for one-time costs of linking Epic to each individual non-Epic system with which they wish to exchange data; in contrast, Epic's competitors have formed the CommonWell Health Alliance which set a common Interoperability Software standard for electronic health records. A 2014 report by the RAND Corporation noted the software was difficult and costly to use in conjunction with other billing systems. The report also cited other research showing that Epic's implementation in the Kaiser Permanente system led to efficiency losses.
Criticisms and controversies:
In September 2017, Epic announced Share Everywhere, which allows patients to authorize any provider who has internet access to view their record in Epic and to send progress notes back. Share Everywhere was named Healthcare Dive's "Health IT Development of the Year" in 2017.
Criticisms and controversies:
UK experience An Epic electronic health record system costing £200 million was installed at Cambridge University Hospitals NHS Foundation Trust in October 2014, the first installation of an Epic system in the UK.After 2.1 million records were transferred to Epic systems, it developed serious problems and the system became unstable. Ambulances were diverted to other hospitals for five hours and hospital consultants noted issues with blood transfusion and pathology services. Other problems included delays to emergency care and appointments, and problems with discharge letters, clinical letters and pathology test results. Chief information officer, Afzal Chaudhry, said "well over 90% of implementation proceeded successfully".In July 2015, the BBC reported that the hospital's finances were being investigated. In September 2015, both the CEO and CFO of the hospital resigned. Problems with the clinical-records system, which were said to have compromised the "ability to report, highlight and take action on data" and to prescribe medication properly, were held to be contributory factors in the organization's sudden failure. In February 2016, digitalhealth.net reported that Clare Marx, president of the Royal College of Surgeons of England and member of the NHS National Information Board, found that at the time of implementation, "staff, patients and management rapidly and catastrophically lost confidence in the system. That took months and a huge amount of effort to rebuild." Danish experience In 2016, Danish health authorities spent 2.8 billion DKK on the implementation of Epic in 18 hospitals in a region with 2.8 million residents. On May 20, Epic went live in the first hospital. Doctors and nurses reported chaos in the hospital and complained of a lack of preparation and training.Since some elements of the Epic system were not properly translated from English to Danish, physicians resorted to Google Translate. As one example, when inputting information about a patient's condition, physicians were given the option to report between the left and the "correct" leg, not the left and right legs. As of 2019, Epic had still not been fully integrated with Denmark's national medical record system. Danish anesthesiologist and computer architect Gert Galster worked to adapt the system. According to Galster, these Epic systems were designed specifically to fit the U.S. health care system, and could not be disentangled for use in Denmark.An audit of the implementation that voiced concerns was published in June 2018. At the end of 2018, 62% of physicians expressed they were not satisfied with the system and 71 physicians signed a petition calling for its removal.
Criticisms and controversies:
Finnish experience In 2012, the Hospital District of Helsinki and Uusimaa (HUS) decided to replace several smaller health record systems with one district-wide system created by Epic. It was called Apotti and would be used by healthcare and social services for the 2.2 million residents in the HUS area. The Apotti system was selected as the provider in 2015 and implementation started in 2018. By November 2022, the Apotti system had cost 625 million euros.After the implementation, complaints from healthcare workers, especially from doctors, started accumulating. The system was accused of being too complicated and that its convoluted UI was endangering patient safety. For example, one patient was administered the wrong chemotherapeutic drug due to an unclear selection menu in the system.In July 2022, a formal complaint demanding that the issues in the system be fixed or the system be removed entirely was sent to the Finnish health care supervising body Valvira. The complaint was signed by 619 doctors that use Apotti.
Criticisms and controversies:
Norwegian experience Central Norway started introducing Epic (branded “Helseplattformen”) in the winter 2023. After approximately two months, the public broadcaster NRK reported that around 25% of the doctors at the region's main hospital considered quitting their job, and that 40% were experiencing stress related health issues due to the new IT system. Previously, health personnel actively demonstrated against the software by marching though the city of Trondheim. Due to the chaos ensuing the introduction, including 16.000 letters not being sent to patients, the Norwegian CEO of the Helseplattformen IT project, Torbjørg Vanvik, had her employment ended by the board. Unexpected cost increases forced the authorities to decrease efforts in other areas, such as a planned initiative on mental health. Employee representatives state that the public will receive ”significantly worse services“.
Criticisms and controversies:
COVID-19 response In 2020, the novel coronavirus pandemic spread in the United States. Epic Systems faced considerable criticism for their initial plan to have their 10,000 employees return to work on-campus. Employees expressed concern about returning to the office, with the first group being required to return as early as August 10 while the pandemic continued to spread. This plan was abandoned, and as of December 2020, employees were still able to work from home. The plan had come about despite a Dane County public health order requiring remote work "to the greatest extent possible." Criticism revolved in particular around the fact that employees were being ordered back to preserve the company "culture," despite CEO Judy Faulkner's admission that work was getting done remotely. According to The Capital Times, who interviewed 26 Epic employees about the plan, "13 [employees] said they have knowledge of managers being demoted for expressing concern about the company’s plans to bring its nearly 10,000 workers back" to on-campus work, and all requested anonymity for fear of employer retribution.In a survey of over 400 Epic employees, 89% of respondents expressed dissatisfaction with how Epic was handling the pandemic. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Plexin**
Plexin:
A plexin is a protein which acts as a receptor for semaphorin family signaling proteins. It is classically known for its expression on the surface of axon growth cones and involvement in signal transduction to steer axon growth away from the source of semaphorin. Plexin also has implications in development of other body systems by activating GTPase enzymes to induce a number of intracellular biochemical changes leading to a variety of downstream effects.
Structure:
Extracellular All plexins have an extracellular SEMA domain at their N-terminus. This is a structural motif common among all semaphorins and plexins and is responsible for this binding of semaphorin dimers, which are the native conformation for these ligands in vivo. This is followed by alternating plexin, semaphorin, and integrin (PSI) domains and immunoglobulin-like, plexin, and transcription factors (IPT) domains. Each of these is named for the proteins in which their structure is conserved. Collectively, the extracellular region resembles a curved stalk projecting in a clockwise direction.Before bindings its semaphorin dimer ligand, associations between the extracellular domains of pre-formed plexin dimers keeps their intracellular domains segregated and inactive. This allows for co-localization of plexin dimers to be primed for binding of semaphorin dimers and activation of intracellular machinery.
Structure:
Intracellular Highly conserved intracellular domains consisting of a bipartite segment which functions as a GTPase-Activating Protein (GAP). Plexin is the only known receptor molecule to have a GAP domain. In the inactive state, these two sections are separated by a Rho-GTPase binding domain (RBD). When the RBD bind to a Rnd-family Rho-GTPases along with plexin dimerization and semaphoring binding, the intracellular segment undergoes conformational changes which allow the separate GAP domains to interact and become active in turning Rap family Rho-GTPases. These GTPases can have a number of downstream effects, but in particular to Plexin expressed on axonal growth cones, the concentration the secondary messenger cyclic guanosine monophosphate (cGMP) increases within the cell.
Structure:
Classes Nine genes have been identified which divide plexins into four subclasses based on structure and homology. These genes include: Class A: PLXNA1, PLXNA2, PLXNA3, PLXNA4A Class B: PLXNB1, PLXNB2, PLXNB3 Class C: PLXNC1 Class D: PLXND1Class A plexins interact with neuropilin co-receptor proteins to strengthen semaphorin binding interactions without altering the mode of binding. The structure of the Class B plexins has an additional extracellular site for cleavage by convertases, enzymes which modify plexin precursor polypeptides into their final peptide sequence, as well as a structural PDZ interaction motif on its C-terminus. C-class plexins have fewer structural Methionine-Related Sequences (MRS) and IPT domains. D-class plexins have an additional modification in one of the MRS domains
Function:
Plexin receptors largely act to signal the binding of semaphorin signaling proteins in a short-distance inhibitory manner. Each class of plexin has a range of specificity, meaning they could bind specifically to one or more semaphorin isomers. Plexins also have varying effects on development depending on their expression in different tissue types. Plexin receptors have implications in neural development and axon growth guidance, angiogenesis and heart development, skeletal and kidney morphogenesis, and in the immune system. Genetic knockout of plexins have shown to be lethal at embryonic stages due to severe developmental defects in body systems regulated by semaphorin-plexin signaling. Malfunction of the plexin signaling pathway has been implicated in human diseases including neurological disorders and cancers.
Function:
Axon guidance Plexin receptors on axon growth cones receive local semaphorin signaling and impede growth in that direction.Plexin activation on growth cones results in actin and microtubule polymer destabilization as well as clathrin-mediated endocytosis, resulting in retraction of growth cone projections.
Angiogenesis and heart development PLXND1 is involved in guiding the growth of new blood vessels. Cells expressing Sema3E do not need additional vascularization. Developing vessels will have their growth towards these cells inhibited upon PLXND1 binding to Sema3E independent of Neuropilin.
PLXNA2 and PLXND1 modulate proper development of cardiac structures.
Skeletal and kidney development During development, PLXNA1 and PLXNA2 are expressed in chondrocytes and osteoblasts, implementing them in regulating bone homeostasis.
PLXND1 has a role in the formation of vertebral bodies of the spinal column by signaling for proper fusing and splitting of the axial elements.
PLXNB1 and PLXNB2 control branching of the ureter in the kidney by inhibiting and promoting it, respectively.
Immune system PLXNA1 promotes dendritic and T cell proliferation.
PLXNA4 inhibits T cell response, but promotes inflammatory cytokine production by macrophages.
PLXNB1 promotes B cell survival, as well as macrophage recruitment.
Role in intelligence In a genome-wide association study, plexins, which are mutated in several monogenic neurodevelopmental disorders, were significantly enriched for associations with high IQ. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Smoked salmon cheesecake**
Smoked salmon cheesecake:
Cheesecake is a sweet dessert made with a soft fresh cheese (typically cottage cheese, cream cheese, quark or ricotta), eggs, and sugar. It may have a crust or base made from crushed cookies (or digestive biscuits), graham crackers, pastry, or sometimes sponge cake. Cheesecake may be baked or unbaked, and is usually refrigerated.
Vanilla, spices, lemon, chocolate, pumpkin, or other flavors may be added to the main cheese layer. Additional flavors and visual appeal may be added by topping the finished dessert with fruit, whipped cream, nuts, cookies, fruit sauce, chocolate syrup, or other ingredients.
Culinary classification:
Modern cheesecake is not usually classified as an actual "cake", despite the name (compare with Boston cream "pie"). Some people classify it as a torte due to the usage of many eggs, which are the sole source of leavening, as a key factor. Others find compelling evidence that it is a custard pie, based on the overall structure, with the separate crust, the soft filling, and the absence of flour. Other sources identify it as a flan, or tart.
Culinary classification:
Savoury cheesecakes Smoked salmon cheesecake is a savoury form, containing smoked salmon. It is most frequently served as an appetizer or a buffet item. Michael Portillo visited a family-run smokehouse on the Isle of Skye, Scotland during his Great British Railway Journeys series. After sampling their smoked salmon cheesecake he commented "you haven't lived till you've tasted this." A smoked salmon cheesecake was a prize-winning recipe in 1996 in Better Homes and Gardens' Prize Tested Recipe Contest. The recipe called for the use of Swiss cheese along with the more usual (for cheesecakes) Ricotta.
History:
An ancient form of cheesecake may have been a popular dish in ancient Greece even prior to Romans' adoption of it with the conquest of Greece. The earliest attested mention of a cheesecake is by the Greek physician Aegimus (5th century BCE), who wrote a book on the art of making cheesecakes (πλακουντοποιικόν σύγγραμμα—plakountopoiikon sungramma). The earliest extant cheesecake recipes are found in Cato the Elder's De Agri Cultura, which includes recipes for three cakes for religious uses: libum, savillum and placenta. Of the three, placenta cake is the most like modern cheesecakes: having a crust that is separately prepared and baked.A more modern version called a sambocade, made with elderflower and rose water, is found in Forme of Cury, an English cookbook from 1390. On this basis, the English chef Heston Blumenthal argues that cheesecake is an English invention.
History:
The modern cheesecake The English name cheesecake has been used only since the 15th century, and the cheesecake did not evolve into its modern form until somewhere around the 18th century. Europeans began removing yeast and adding beaten eggs to the cheesecake instead. With the overpowering yeast flavor gone, the result tasted more like a dessert treat. The early 19th-century cheesecake recipes in A New System of Domestic Cookery by Maria Rundell are made with cheese curd and fresh butter. One version is thickened with blanched almonds, eggs and cream, and the cakes may have included currants, brandy, raisin wine, nutmeg and orange flower water.
History:
Modern commercial American cream cheese was developed in 1872, when William Lawrence, from Chester, New York, was searching for a way to recreate the soft, French cheese Neufchâtel. He discovered up with a way of making an "unripened cheese" that is heavier and creamier; other dairymen came up with similar creations independently.Modern cheesecake comes in two different types. Along with the baked cheesecake, some cheesecakes are made with uncooked cream cheese on a crumbled-cookie or graham cracker base. This type of cheesecake was invented in the United States.
National varieties:
Cheesecakes can be broadly categorized into two basic types: baked and unbaked. Some do not have a crust or base. Cheesecake comes in a variety of styles based on region: Africa South Africa One popular variant of cheesecake in South Africa is made with whipped cream, cream cheese, gelatin for the filling, and a buttered digestive biscuit crust. It is not baked, and is sometimes made with Amarula liqueur. This variant is very similar to British cheesecake. This cheesecake is more common in British South African communities.
National varieties:
Asia Japan Japanese cheesecake, or soufflé-style or cotton cheesecake, is made with cream cheese, butter, sugar, and eggs, and has a characteristically wobbly, airy texture, similar to chiffon cake. No-bake cheesecakes are known as rare cheesecake (Japanese: レアチーズケーキ).
National varieties:
Philippines The most prominent version of cheesecake in the Philippines is ube cheesecake. It is made with a base of crushed graham crackers and an upper layer of cream cheese and ube halaya (mashed purple yam with milk, sugar, and butter). It can be prepared baked or simply refrigerated. Like other ube desserts in the Philippines, it is characteristically purple in color.
National varieties:
Europe Spain Basque cheesecake was created in 1990 by Santiago Rivera of the La Viña restaurant in the Basque Country, Spain. It is composed of burnt custard and no crust. It achieved popularity online in the 2010s, helped by a recipe published by the British food writer Nigella Lawson. In 2023, the British restaurant critic Jay Rayner complained that Basque cheesecake had become overabundant in London.
National varieties:
Russia Russian-style cheesecake (Vatrushka) is in the form of a dough ring and filled with quark or cottage cheese.
North America United States The United States has several different recipes for cheesecake and this usually depends on the region in which the cake is baked, as well as the cultural background of the person baking it.
National varieties:
Chicago Chicago-style cheesecake is a baked cream cheese version that is firm on the outside with a soft and creamy texture on the inside. These cheesecakes are often made in a greased cake pan and are relatively fluffy in texture. The crust used with this style of cheesecake is most commonly made from shortbread that is crushed and mixed with sugar and butter. Some frozen cheesecakes are Chicago-style.
National varieties:
New York New York–style cheesecake uses a cream cheese base, also incorporating heavy cream or sour cream. The typical New York cheesecake is rich and has a dense, smooth, and creamy consistency.
Galleries:
Cheesecakes from around the world Fruit cheesecakes | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Avaya VSP 4000 series**
Avaya VSP 4000 series:
The Avaya Virtual Services Platform 4000 series (VSP 4000) are products that, in computer networking terms, are standalone switch/routers (layer 2/layer 3) designed and manufactured by Avaya for Ethernet-based networks. The VSP 4000 hardware is a derivative of the earlier Ethernet routing switch 4000 series, leveraging certain shared components, but implementing a new, completely different, operating system derived from the virtual service platform 9000 series. The role of the VSP 4000 is to extend fabric-based network virtualization services to smaller, remote locations, thereby creating a single service delivery network.
Avaya VSP 4000 series:
The VSP 4000 offers a range of network virtualization services that are based on Avaya's extended implementation of Shortest Path Bridging; marketed as the 'Avaya VENA Fabric Connect' technology. The first software release supports: Layer 2 virtualized services that extend VLANs across the fabric (including across subnets and long distances) Layer 3 virtualized services that interconnect and extend VRFs across the fabric Native routing between layer 2 and layer 3 virtualized services for access to shared services IP shortcut routing that enables direct layer 3 connectivity between individual end-points without requiring deployment of an additional IGP (e.g. OSPF).These capabilities are positioned are supporting the following deployment scenarios: Virtualized small and mid-sized Enterprise Distributed enterpriseDeployments would be made to facilitate the following business situations: End-to-end traffic separation for multi-tenancy or for security / regulatory compliance (i.e. PCI DSS) Integrated video surveillance
History:
The first VSP 4000 models were made available in April 2013.
The first models delivered in the series were: VSP 4850GTS, a 1RU Layer 2/Layer 3 Switch that is equipped with 48 x 10/100/1000BASE-T ports (including two common Uplink ports offering SFP connectivity) plus 2 x 10 Gigabit Ethernet ports that feature SFP+ physical connectivity.
VSP 4850GTS-PWR+, a similar product the VSP 4850GTS, with the addition of supporting 802.3at Power-over-Ethernet Plus (PoE+) on the copper ports.
VSP 4850GTS-DC, a similar product the VSP 4850GTS, but with DC power instead of AC.In June 2014, a further model was added: VSP 4450GSX-PWR+, a 1RU Layer 2/Layer 3 Switch that is equipped with 36 x 1000BASE-SFP ports, 12 x 10/100/1000BASE-T ports that support 802.3at PoE+, plus 2 x 10GBASE-SFP+ Ethernet ports (that also support Gigabit SFPs). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Biopsychosocial model**
Biopsychosocial model:
Biopsychosocial models are a class of trans-disciplinary models which look at the interconnection between biology, psychology, and socio-environmental factors. These models specifically examine how these aspects play a role in topics ranging from human development, to health and disease, to information processing, and to conflict.
Biopsychosocial model:
According to Derick T. Wade and Peter W. Halligan, as of 2017, it is generally accepted that "illness and health are the result of an interaction between biological, psychological, and social factors."The term was first used to describe a model advocated by George L. Engel in 1977. It now also refers to any model which takes a similar approach, and has become an alternative to the biomedical and/or psychological dominance of many health care systems.
Biopsychosocial model:
Gender can be thought of as biopsychosocial, as it is a complex matter formed from social, psychological, and biological aspects.
History:
George L. Engel and Jon Romano of the University of Rochester in 1977, are widely credited with being the first to propose a biopsychosocial model. However, it had been proposed 100 years earlier and by others. Engel struggled with the then-prevailing biomedical approach to medicine as he strove for a more holistic approach by recognizing that each patient has their own thoughts, feelings, and history. In developing his model, Engel framed it for both illnesses and psychological problems.
History:
Engel's biopsychosocial model reflects the development of illness through the complex interaction of biological factors (genetic, biochemical, etc.), psychological factors (mood, personality, behaviour, etc.) and social factors (cultural, familial, socioeconomic, medical, etc.). For example, a person may have a genetic predisposition for depression, but they must have social factors such as extreme stress at work and family life and psychological factors such as a perfectionistic tendencies which all trigger this genetic code for depression. A person may have a genetic predisposition for a disease, but social and cognitive factors must trigger the illness.
History:
Specifically, Engel broadened medical thinking by re-proposing a separation of body and mind. The idea of mind–body dualism goes back at least to René Descartes, but was forgotten during the biomedical approach. Engel emphasized that the biomedical approach is flawed because the body alone does not contribute to illness. Instead, the individual mind (psychological and social factors) play a significant role in how an illness is caused and how it is treated. Engel proposed a dialogue between the patient and the doctor in order to find the most effective treatment solution.Similarly, materialistic and reductionist ideas proposed with the biomedical model are flawed because they cannot be verified on a cellular level (according to Engel). Instead, the proposed model focuses on the research of past psychologists such as Urie Bronfenbrenner, popularized by his belief that social factors play a role in developing illnesses and behaviors. Simply, Engel used Bronfenbrenner's research as a column of his biopsychosocial model and framed this model to display health at the center of social, psychological, and biological aspects.
History:
After publication, the biopsychosocial model was adopted by the World Health Organization (WHO) in 2002 as a basis for the International Classification of Function (ICF). However, The WHO definition of health adopted in 1948 clearly implied a broad socio-medical perspective.
Current status of the BPS model:
The biopsychosocial (BPS) model is still widely used as both a philosophy of clinical care and a practical clinical guide useful for broadening the scope of a clinician's gaze. Dr. Borrell-Carrió and colleagues reviewed Engel's model 25 years on. They proposed the model had evolved into a BPS and relationship-centered framework for physicians. They proposed three clarifications to the model, and identified seven established principles.
Current status of the BPS model:
Self-awareness.
Active cultivation of trust.
An emotional style characterized by empathic curiosity.
Self-calibration as a way to reduce bias.
Educating the emotions to assist with diagnosis and forming therapeutic relationships.
Using informed intuition.
Communicating clinical evidence to foster dialogue, not just the mechanical application of protocol.Gatchel and colleagues argued in 2007 the biopsychosocial model is the most widely accepted as the most heuristic approach to understanding and treating chronic pain.
Relevant theories and theorists:
Other theorists and researchers are using the term biopsychosocial, or sometimes bio-psycho-social to distinguish Engel's model.Lumley and colleagues used a non-Engel model to conduct a biopsychosocial assessment of the relationship between and pain and emotion. Zucker and Gomberg used a non-Engel biopsychosocial perspective to assess the etiology of alcoholism in 1986.Crittenden considers the Dynamic-Maturational Model of Attachment and Adaptation (DMM), to be a biopsychosocial model. It incorporates many disciplines to understand human development and information processing.Kozlowska's Functional Somatic Symptoms model uses a biopsychosocial approach to understand somatic symptoms. Siegel's Interpersonal Neurobiology (IPNB) model is similar, although, perhaps to distinguish IPNB from Engel's model, he describes how the brain, mind, and relationships are part of one reality rather three separate elements. Most trauma -and violence-informed care models are biopsychosocial models.
Biopsychosocial research:
Wickrama and colleagues have conducted several biopsychosocial-based studies examining marital dynamics. In a longitudinal study of women divorced midlife they found that divorce contributed to an adverse biopsychosocial process for the women. In another study of enduring marriages, they looked to see if hostile marital interactions in the early middle years could wear down couples regulator systems through greater psychological distress, more health-risk behaviors, and a higher body mass index (BMI). Their findings confirmed negative outcomes and increased vulnerability to later physical health problems for both husbands and wives.Kovacs and colleagues meta-study examined the biopsychosocial experiences of adults with congenital heart disease. Zhang and colleagues used a biopsychosocial approach to examine parents own physiological response when facing children's negative emotions, and how it related to parents’ ability to engage in sensitive and supportive behaviors. They found parents’ physiological regulatory functioning was an important factor in shaping parenting behaviors directed toward children's emotions.
Biopsychosocial research:
A biopsychosocial approach was used to assess race and ethnic differences in aging and to develop the Michigan Cognitive Aging Project. Banerjee and colleagues used a biopsychosocial narrative to describe the dual pandemic of suicide and COVID-19.
Potential applications:
When Engel first proposed the biopsychosocial model it was for the purpose of better understanding health and illness. While this application still holds true the model is relevant to topics such as health, medicine, and development. Firstly, as proposed by Engel, it helps physicians better understand their whole patient. Considering not only physiological and medical aspects but also psychological and sociological well-being. Furthermore, this model is closely tied to health psychology. Health psychology examines the reciprocal influences of biology, psychology, behavioral, and social factors on health and illness.
Potential applications:
One application of the biopsychosocial model within health and medicine relates to pain, such that several factors outside an individual's health may affect their perception of pain. For example, a 2019 study linked genetic and biopsychosocial factors to increased post-operative shoulder pain. Future studies are needed to model and further explore the relationship between biopsychosocial factors and pain.The developmental applications of this model are equally relevant. One particular advantage of applying the biopsychosocial model to developmental psychology is that it allows for an intersection within the nature versus nurture debate. This model provides developmental psychologists a theoretical basis for the interplay of both hereditary and psychosocial factors on an individual's development.
In gender:
Gender is thought of by some as biopsychosocial. According to the Gender Spectrum Organization, "A person's gender is the complex interrelationship between three dimensions: body, identity, and social gender."According to Alex Iantaffi and Meg-John Barker, biological, psychological, and social factors all feed back into each other in complex ways to form a person's gender.
Criticisms:
There have been a number of criticisms of Engel's biopsychosocial model. Benning summarized the arguments against the model including that it lacked philosophical coherence, was insensitive to patients' subjective experience, was unfaithful to the general systems theory that Engel claimed it be rooted in, and that it engendered an undisciplined eclecticism that provides no safeguards against either the dominance or the under-representation of any one of the three domains of bio, psycho, or social.Psychiatrist Hamid Tavakoli argues that Engel's BPS model should be avoided because it unintentionally promotes an artificial distinction between biology and psychology, and merely causes confusion in psychiatric assessments and training programs, and that ultimately it has not helped the cause of trying to de-stigmatize mental health. The perspectives model does not make that arbitrary distinction.A number of these criticisms have been addressed over recent years. For example, the BPS-Pathways model describes how it is possible to conceptually separate, define, and measure biological, psychological, and social factors, and thereby seek detailed interrelationships among these factors.While Engel's call to arms for a biopsychosocial model has been taken up in several healthcare fields and developed in related models, it has not been adopted in acute medical and surgical domains, as of 2017. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**PARP4**
PARP4:
Poly [ADP-ribose] polymerase 4 is an enzyme that in humans is encoded by the PARP4 gene.This gene encodes poly(ADP-ribosyl)transferase-like 1 protein, which is capable of catalyzing a poly(ADP-ribosyl)ation reaction. This protein has a catalytic domain which is homologous to that of poly (ADP-ribosyl) transferase, but lacks an N-terminal DNA binding domain which activates the C-terminal catalytic domain of poly (ADP-ribosyl) transferase. Since this protein is not capable of binding DNA directly, its transferase activity may be activated by other factors such as protein-protein interaction mediated by the extensive carboxyl terminus.
Interactions:
PARP4 has been shown to interact with Major vault protein. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**PLK2**
PLK2:
Serine/threonine-protein kinase PLK2 is an enzyme that in humans is encoded by the PLK2 gene.Serum-inducible kinase is a member of the 'polo' family of serine/threonine protein kinases that have a role in normal cell division. [supplied by OMIM] | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Somatic nervous system**
Somatic nervous system:
The somatic nervous system (SNS), or voluntary nervous system is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles.The somatic nervous system consists of nerves carrying afferent nerve fibers, which relay sensation from the body to the central nervous system (CNS), and nerves carrying efferent nerve fibers, which relay motor commands from the CNS to stimulate muscle contraction.The a- of afferent and the e- of efferent correspond to the prefixes ad- (to, toward) and ex- (out of).
Structure:
There are 43 segments of nerves in the human body. With each segment, there is a pair of sensory and motor nerves. In the body, 31 segments of nerves are in the spinal cord and 12 are in the brain stem. Besides these, thousands of association nerves are also present in the body.Thus the somatic nervous system consists of two parts: Spinal nerves: They are mixed nerves that carry sensory information into and motor commands out of the spinal cord.
Structure:
Cranial nerves: They are the nerve fibers that carry information into and out of the brain stem. They include smell, eye muscles, mouth, taste, ear, neck, shoulders, and tongue.
Function:
The somatic nervous system controls all voluntary muscular systems within the body, and the process of voluntary reflex arcs.The basic route of nerve signals within the efferent somatic nervous system involves a sequence that begins in the upper cell bodies of motor neurons (upper motor neurons) within the precentral gyrus (which approximates the primary motor cortex). Stimuli from the precentral gyrus are transmitted from upper motor neurons, down the corticospinal tract, to lower motor neurons (alpha motor neurons) in the brainstem and ventral horn of the spinal cord: upper motor neurons release a neurotransmitter called glutamate from their axon terminal knobs, which is received by glutamate receptors on the lower motor neurons: from there, acetylcholine is released from the axon terminal knobs of alpha motor neurons and received by postsynaptic receptors (nicotinic acetylcholine receptors) of muscles, thereby relaying the stimulus to contract muscle fibers.
Function:
Reflex arcs A reflex arc is a neural circuit that creates a more or less automatic link between a sensory input and a specific motor output. Reflex circuits vary in complexity—the simplest spinal reflexes are mediated by a two-element chain, of which in the human body there is only one, also called a monosynaptic reflex (there is only one synapse between the two neurones taking part in the arc: sensory and motor). The singular example of a monosynaptic reflex is the patellar reflex. The next simplest reflex arc is a three-element chain, beginning with sensory neurons, which activate interneurons inside of the spinal cord, which then activate motor neurons. Some reflex responses, such as withdrawing the hand after touching a hot surface, are protective, but others, such as the patellar reflex ("knee jerk") activated by tapping the patellar tendon, contribute to ordinary behavior.
Other animals:
In invertebrates, depending on the neurotransmitter released and the type of receptor it binds, the response in the muscle fiber could either be excitatory or inhibitory. For vertebrates, however, the response of a skeletal striated muscle fiber to a neurotransmitter – always acetylcholine (ACh) – can only be excitatory. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cabin cruiser**
Cabin cruiser:
A cabin cruiser is a type of power boat that provides accommodation for its crew and passengers inside the structure of the craft.
Cabin cruiser:
A cabin cruiser usually ranges in size from 7.6 to 13.7 m (25 to 45 ft) in length, with larger pleasure craft usually considered yachts. Many cabin cruisers can be recovered and towed with a trailer and thus easily stored on land, which reduces maintenance and expense. These craft are generally equipped with a head (toilet), a galley, and at least one berth. Most cabin cruisers usually have a small dining area and some have an aft cabin (a cabin to the rear of the cockpit, with a double bed). Some cabin cruisers are equipped with heating, air conditioning, and power generators. Most also have water heaters and shore power electric systems.The cabin cruiser provides many of the amenities of larger yachts, while costing much less and normally being fully operable by the owner, whereas larger yachts often require a professional crew.
Cabin cruiser:
Most newer cabin cruisers are faster than older models because of improved aerodynamic and hydrodynamic designs. Cabin cruisers are generally able to handle the water well because of their size and give a stable ride. They are generally spacious in the cockpit (open seating area towards aft or centre).
In the UK, purpose-built cabin cruisers were popular on the canal network in the 1960s and 1970s. Leading manufacturers were Norman, Viking, Microplus, Freeman, and Dawncraft. Today, they are more commonly found on the navigable rivers rather than canals. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Auxology**
Auxology:
Auxology (from Greek αὔξω, auxō, or αὐξάνω, auxanō 'grow'; and -λογία, -logia) is a meta-term covering the study of all aspects of human physical growth. (Although, it is also fundamental of biology.) Auxology is a multi-disciplinary science involving health sciences/medicine (pediatrics, general practice, endocrinology, neuroendocrinology, physiology, epidemiology), and to a lesser extent: nutrition science, genetics, anthropology, anthropometry, ergonomics, history, economic history, economics, socio-economics, sociology, public health, and psychology, among others.
History of auxology:
""Ancient Babylonians and Egyptians left some writings on child growth and variation in height between ethnic groups. In the late 18th century, scattered documents of child growth started to appear in the scientific literature, the studies of Jamberts in 1754 and the annual measurements of the son of Montbeillard published by Buffon in 1777 being the most cited ones [1]. Louis René Villermé (1829) was the first to realize that growth and adult height of an individual depend on the country's socio-economic situation. In the 19th century, the number of growth studies rapidly increased, with increasing interest also in growth velocity [2]. Günther documented monthly height increments in a group of 33 boys of various ages [3]. Kotelmann [4] first noted the adolescent growth spurt. In fact, the adolescent growth spurt appears to be a novel achievement in the history of human growth and the amount and intensity of the spurt seems to be greatest in tall and affluent populations [5]. By the beginning of the 20th century, national growth tables were published for most European nations with data for height, weight, and attempts to relate weight and height, though none of these were references in the proper sense of the word as the data were usually derived from small and unrepresentative samples. After the 1930s X-ray imaging of hand and wrist became popular for determining bone age. Current auxo-logical knowledge is based on the large national studies performed in the 1950s, 1960s and the 1970s, many of them inaugurated by James Tanner [1]. In the late 1970s a new school of anthropometric history [6] emerged among historians and economists. The main aim of this school was to evaluate secular changes in conscript height during the last 100–200 years and to associate them with socio-economic changes and political events in the different countries [7]. In the 1980s and the 1990s new mathematical approaches have been added of which the LMS method has strongly been recommended for constructing modern growth reference tables [8,9]: M stands for mean, S stands for a scaling parameter, and L stands for the Box–Cox power that is required to transform the skewed data to normality. Meanwhile, many national and international growth references are based on this technology. And in view of the general idea of growth and adult height being a mirror of nutritional status, health and wealth [10], these techniques have generally been accepted for routine screening pro-grams in Public Health. Anthropometry has also been considered essential for security purposes, for the usability of industrial products, and it has become routine for car and clothing industries, for furniture, housing, and many other aspects of design in the modern environment. Growth is defined as an increase in size over time. But the rigid metric of physical time is not directly related to the tempo at which an organism develops, matures and ages. Calendar time differs in its meaning in a fast maturing and in a slow maturing organism. Fast maturing children appear tall and "older" than their calendar age suggests, late maturers appear "too young" and often short even though both may later reach the same adult size. Whereas metric scales exist for height, weight and other amplitude parameters, there are no continuous scales for maturation and developmental tempo. Instead we are used to work with substitutes like the 5-step Tanner scale for staging puberty, and age equivalents for describing bone..." is an excerpt taken from Human Growth and Development by Borms, J., R. Hauspie, A. Sand, C. Susanne, and M. Hebbelinck, edsFrom the taken section above we can see that ancient cultures left writings and indicators of growth from childhood into adulthood, such as the Ancient Babylonians and Egyptians. Though it wouldn't been until the later part of the 1700s that it would appear in scientific literature in the light of the Age of Enlightenment. A movement of philosophical and scientific advancement and understanding that dominated the western world in the 18th century. As the ideals and respect of science and mathematics grew we see such men as Louis-René Villermé a physician and economist begin to take interest and realize the growth of individuals into adulthood had factors in their socio-economic situation and status. From there the study would continue to grow at a rapid rate.
History of auxology:
Contemporaries would then catch on reaching from the interest in Growth chart which kept marks on growth velocity into more medical sided interest for public health in the sense of tracking one's own growth and health to set standards.
Auxology in relation to anthropology:
As Biological anthropology is a sub-field of anthropology that provides insight into the biological/physical perspective of human beings and our ancestors, one can easily see how auxology relates to the anthropological fields. This can be seen through the study of physical human development and growth to the slight Sexual dimorphism within Human along with the maturing of the body such as the physical change from childhood into adulthood.
Auxology in relation to anthropology:
Auxology can also be used in the comparing of remains such as that of Neanderthal, Homo habilis and Australopithecus afarensis to any relation of Hominidae. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Recombination hotspot**
Recombination hotspot:
Recombination hotspots are regions in a genome that exhibit elevated rates of recombination relative to a neutral expectation. The recombination rate within hotspots can be hundreds of times that of the surrounding region. Recombination hotspots result from higher DNA break formation in these regions, and apply to both mitotic and meiotic cells. This appellation can refer to recombination events resulting from the uneven distribution of programmed meiotic double-strand breaks.
Meiotic recombination:
Meiotic recombination through crossing over is thought to be a mechanism by which a cell promotes correct segregation of homologous chromosomes and repair of DNA damages. Crossing over requires a DNA double-stranded break followed by strand invasion of the homolog and subsequent repair. Initiation sites for recombination are usually identified by mapping crossing over events through pedigree analysis or through analysis of linkage disequilibrium. Linkage disequilibrium has identified more than 30,000 hotspots within the human genome. In humans, the average number of crossover recombination events per hotspot is one crossover per 1,300 meioses, and the most extreme hotspot has a crossover frequency of one per 110 meioses.
Genomic rearrangements:
Recombination can also occur due to errors in DNA replication that lead to genomic rearrangements. These events are often associated with pathology. However, genomic rearrangement is also thought to be a driving force in evolutionary development as it gives rise to novel gene combinations. Recombination hotspots may arise from the interaction of the following selective forces: the benefit of driving genetic diversity through genomic rearrangement coupled with selection acting to maintain favorable gene combinations.
Initiation sites:
DNA contains "fragile sites" within the sequence that are more prone to recombination. These fragile sites are associated with the following trinucleotide repeats: CGG-CCG, GAG-CTG, GAA-TTC, and GCN-NGC. These fragile sites are conserved in mammals and in yeast, suggesting that the instability is caused by something inherent to the molecular structure of DNA and is associated with DNA-repeat instability. These fragile sites are thought to form hairpin structures on the lagging strand during replication from single-stranded DNA base-pairing with itself in the trinucleotide repeat region. These hairpin structures cause DNA breaks that lead to a higher frequency of recombination at these sites.Recombination hotspots are also thought to arise due to higher-order chromosome structure that make some areas of the chromosome more accessible to recombination than others. A double stranded-break initiation site was identified in mice and yeast, located at a common chromatin feature: the trimethylation of lysine 4 of histone H3 (H3K4me3).Recombination hotspots do not seem to be solely caused by DNA sequence arrangements or chromosome structure. Alternatively, initiation sites of recombination hotspots can be coded for in the genome. Through the comparison of recombination between different mouse strains, locus Dsbc1 was identified as a locus that contributes to the specification of initiation sites in the genome in at least two recombination hotspot locations. Additional crossing over mapping located the Dsbc1 locus to the 12.2 to 16.7-Mb region of mouse chromosome 17, which contains the PRDM9 gene. The PRDM9 gene encodes a histone methyltransferase in the Dsbc1 region, providing evidence of a non-random, genetic basis for recombination initiation sites in mice. Rapid evolution of the PRDM9 gene explains the observation that human and chimpanzees share few recombination hotspots, despite a high level of sequence identity.
Transcription associated recombination:
Homologous recombination in functional regions of DNA is strongly stimulated by transcription, as observed in a range of different organisms. Transcription associated recombination appears to be due, at least in part, to the ability of transcription to open the DNA structure and enhance accessibility of DNA to exogenous chemicals and internal metabolites that cause recombinogenic DNA damages. These findings suggest that transcription-associated recombination may contribute significantly to recombination hotspot formation.
Viral recombination hotspots:
Homologous recombination is very frequent in RNA viruses. Recombination frequently occurs among very similar viruses, where crossover sites may occur anywhere across the genome, but after selection pressure these sites tend to localize in certain regions/hotspots. For example, in Enteroviruses, recombination hotspots have been identified at the 5'UTR-capsid region junction, and at the beginning of the P2 region. These two hotspots flank the P1 region that encodes for the capsid. In coronaviruses, the Spike genomic region is a recombination hotspot. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Wiener deconvolution**
Wiener deconvolution:
In mathematics, Wiener deconvolution is an application of the Wiener filter to the noise problems inherent in deconvolution. It works in the frequency domain, attempting to minimize the impact of deconvolved noise at frequencies which have a poor signal-to-noise ratio.
The Wiener deconvolution method has widespread use in image deconvolution applications, as the frequency spectrum of most visual images is fairly well behaved and may be estimated easily.
Wiener deconvolution is named after Norbert Wiener.
Definition:
Given a system: y(t)=(h∗x)(t)+n(t) where ∗ denotes convolution and: x(t) is some original signal (unknown) at time t .h(t) is the known impulse response of a linear time-invariant system n(t) is some unknown additive noise, independent of x(t) y(t) is our observed signalOur goal is to find some g(t) so that we can estimate x(t) as follows: x^(t)=(g∗y)(t) where x^(t) is an estimate of x(t) that minimizes the mean square error ϵ(t)=E|x(t)−x^(t)|2 ,with E denoting the expectation.
Definition:
The Wiener deconvolution filter provides such a g(t) . The filter is most easily described in the frequency domain: G(f)=H∗(f)S(f)|H(f)|2S(f)+N(f) where: G(f) and H(f) are the Fourier transforms of g(t) and h(t) ,S(f)=E|X(f)|2 is the mean power spectral density of the original signal x(t) ,N(f)=E|V(f)|2 is the mean power spectral density of the noise n(t) ,X(f) , Y(f) , and V(f) are the Fourier transforms of x(t) , and y(t) , and n(t) , respectively, the superscript ∗ denotes complex conjugation.The filtering operation may either be carried out in the time-domain, as above, or in the frequency domain: X^(f)=G(f)Y(f) and then performing an inverse Fourier transform on X^(f) to obtain x^(t) Note that in the case of images, the arguments t and f above become two-dimensional; however the result is the same.
Interpretation:
The operation of the Wiener filter becomes apparent when the filter equation above is rewritten: G(f)=1H(f)[11+1/(|H(f)|2SNR(f))] Here, 1/H(f) is the inverse of the original system, SNR(f)=S(f)/N(f) is the signal-to-noise ratio, and |H(f)|2SNR(f) is the ratio of the pure filtered signal to noise spectral density. When there is zero noise (i.e. infinite signal-to-noise), the term inside the square brackets equals 1, which means that the Wiener filter is simply the inverse of the system, as we might expect. However, as the noise at certain frequencies increases, the signal-to-noise ratio drops, so the term inside the square brackets also drops. This means that the Wiener filter attenuates frequencies according to their filtered signal-to-noise ratio.
Interpretation:
The Wiener filter equation above requires us to know the spectral content of a typical image, and also that of the noise. Often, we do not have access to these exact quantities, but we may be in a situation where good estimates can be made. For instance, in the case of photographic images, the signal (the original image) typically has strong low frequencies and weak high frequencies, while in many cases the noise content will be relatively flat with frequency.
Derivation:
As mentioned above, we want to produce an estimate of the original signal that minimizes the mean square error, which may be expressed: ϵ(f)=E|X(f)−X^(f)|2 .The equivalence to the previous definition of ϵ , can be derived using Plancherel theorem or Parseval's theorem for the Fourier transform.
Derivation:
If we substitute in the expression for X^(f) , the above can be rearranged to ϵ(f)=E|X(f)−G(f)Y(f)|2=E|X(f)−G(f)[H(f)X(f)+V(f)]|2=E|[1−G(f)H(f)]X(f)−G(f)V(f)|2 If we expand the quadratic, we get the following: ϵ(f)=[1−G(f)H(f)][1−G(f)H(f)]∗E|X(f)|2−[1−G(f)H(f)]G∗(f)E{X(f)V∗(f)}−G(f)[1−G(f)H(f)]∗E{V(f)X∗(f)}+G(f)G∗(f)E|V(f)|2 However, we are assuming that the noise is independent of the signal, therefore: E{X(f)V∗(f)}=E{V(f)X∗(f)}=0 Substituting the power spectral densities S(f) and N(f) , we have: ϵ(f)=[1−G(f)H(f)][1−G(f)H(f)]∗S(f)+G(f)G∗(f)N(f) To find the minimum error value, we calculate the Wirtinger derivative with respect to G(f) and set it equal to zero.
Derivation:
dϵ(f)dG(f)=0⇒G∗(f)N(f)−H(f)[1−G(f)H(f)]∗S(f)=0 This final equality can be rearranged to give the Wiener filter. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**PSR J0901–4046**
PSR J0901–4046:
PSR J0901–4046 is an ultra-long period pulsar. Its period, 75.9 seconds, is the longest for any known neutron star pulsar (some objects believed to be white dwarf pulsars, such as AR Scorpii, have longer periods). Its period is more than three times longer than that of PSR J0250+5854, the previous long period record-holder. The pulses are narrow; radio emission is seen from PSR J0901–4046 for only 0.5% of its rotation period.PSR J0901–4046 was discovered serendipitously on September 27, 2020, by the MeerTRAP team, when a single pulse from it was noticed during MeerKAT observations of Vela X-1 (which is less than 1/4 degree away from PSR J0901–4046 on the sky). After that pulse was detected, further examination of the data revealed that 14 weaker pulses were present in the ~30 minute long data set, but they had been missed by the real-time detection software. The deepest image of the MeerKAT field showed a diffuse shell-like structure that may be a supernova remnant associated with the birth of the neutron star.PSR J0901–4046's period, combined with its period time derivative of 2.25×10−13 second/second, implies a characteristic age of 5.3 million years. The discovery of PSR J0901–4046 challenges the understanding of how neutron stars evolve. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Pitofenone**
Pitofenone:
Pitofenone is an antispasmodic. Pitofenone is typically used in combination with fenpiverinium bromide, and metamizole sodium. Previously produced as Baralgin by Sanofi Aventis, the drug is currently sold in Eastern Europe under various trade names, including Spasmalgon (Actavis, Bulgaria), Revalgin (Shreya, India), Spasgan (Wockhardt, India), Bral (Micro Labs, India), and others. It relieves pain and spasms of smooth muscles. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Systolic array**
Systolic array:
In parallel computer architectures, a systolic array is a homogeneous network of tightly coupled data processing units (DPUs) called cells or nodes. Each node or DPU independently computes a partial result as a function of the data received from its upstream neighbours, stores the result within itself and passes it downstream. Systolic arrays were first used in Colossus, which was an early computer used to break German Lorenz ciphers during World War II. Due to the classified nature of Colossus, they were independently invented or rediscovered by H. T. Kung and Charles Leiserson who described arrays for many dense linear algebra computations (matrix product, solving systems of linear equations, LU decomposition, etc.) for banded matrices. Early applications include computing greatest common divisors of integers and polynomials. They are sometimes classified as multiple-instruction single-data (MISD) architectures under Flynn's taxonomy, but this classification is questionable because a strong argument can be made to distinguish systolic arrays from any of Flynn's four categories: SISD, SIMD, MISD, MIMD, as discussed later in this article.
Systolic array:
The parallel input data flows through a network of hard-wired processor nodes, which combine, process, merge or sort the input data into a derived result. Because the wave-like propagation of data through a systolic array resembles the pulse of the human circulatory system, the name systolic was coined from medical terminology. The name is derived from systole as an analogy to the regular pumping of blood by the heart.
Applications:
Systolic arrays are often hard-wired for specific operations, such as "multiply and accumulate", to perform massively parallel integration, convolution, correlation, matrix multiplication or data sorting tasks. They are also used for dynamic programming algorithms, used in DNA and protein sequence analysis.
Architecture:
A systolic array typically consists of a large monolithic network of primitive computing nodes which can be hardwired or software configured for a specific application. The nodes are usually fixed and identical, while the interconnect is programmable. The more general wave front processors, by contrast, employ sophisticated and individually programmable nodes which may or may not be monolithic, depending on the array size and design parameters. The other distinction is that systolic arrays rely on synchronous data transfers, while wavefront tend to work asynchronously.
Architecture:
Unlike the more common Von Neumann architecture, where program execution follows a script of instructions stored in common memory, addressed and sequenced under the control of the CPU's program counter (PC), the individual nodes within a systolic array are triggered by the arrival of new data and always process the data in exactly the same way. The actual processing within each node may be hard wired or block micro coded, in which case the common node personality can be block programmable.
Architecture:
The systolic array paradigm with data-streams driven by data counters, is the counterpart of the Von Neumann architecture with instruction-stream driven by a program counter. Because a systolic array usually sends and receives multiple data streams, and multiple data counters are needed to generate these data streams, it supports data parallelism.
Goals and benefits:
A major benefit of systolic arrays is that all operand data and partial results are stored within (passing through) the processor array. There is no need to access external buses, main memory or internal caches during each operation as is the case with Von Neumann or Harvard sequential machines. The sequential limits on parallel performance dictated by Amdahl's Law also do not apply in the same way, because data dependencies are implicitly handled by the programmable node interconnect and there are no sequential steps in managing the highly parallel data flow.
Goals and benefits:
Systolic arrays are therefore extremely good at artificial intelligence, image processing, pattern recognition, computer vision and other tasks that animal brains do particularly well. Wavefront processors in general can also be very good at machine learning by implementing self configuring neural nets in hardware.
Classification controversy:
While systolic arrays are officially classified as MISD, their classification is somewhat problematic. Because the input is typically a vector of independent values, the systolic array is definitely not SISD. Since these input values are merged and combined into the result(s) and do not maintain their independence as they would in a SIMD vector processing unit, the array cannot be classified as such. Consequently, the array cannot be classified as a MIMD either, because MIMD can be viewed as a mere collection of smaller SISD and SIMD machines.
Classification controversy:
Finally, because the data swarm is transformed as it passes through the array from node to node, the multiple nodes are not operating on the same data, which makes the MISD classification a misnomer. The other reason why a systolic array should not qualify as a MISD is the same as the one which disqualifies it from the SISD category: The input data is typically a vector not a single data value, although one could argue that any given input vector is a single item of data.
Classification controversy:
In spite of all of the above, systolic arrays are often offered as a classic example of MISD architecture in textbooks on parallel computing and in engineering classes. If the array is viewed from the outside as atomic it should perhaps be classified as SFMuDMeR = single function, multiple data, merged result(s).
Systolic arrays use a pre-defined computational flow graph that connects their nodes. Kahn process networks use a similar flow graph, but are distinguished by the nodes working in lock-step in the systolic array: in a Kahn network, there are FIFO queues between each node.
Detailed description:
A systolic array is composed of matrix-like rows of data processing units called cells. Data processing units (DPUs) are similar to central processing units (CPUs), (except for the usual lack of a program counter, since operation is transport-triggered, i.e., by the arrival of a data object). Each cell shares the information with its neighbors immediately after processing. The systolic array is often rectangular where data flows across the array between neighbour DPUs, often with different data flowing in different directions. The data streams entering and leaving the ports of the array are generated by auto-sequencing memory units, ASMs. Each ASM includes a data counter. In embedded systems a data stream may also be input from and/or output to an external source.
Detailed description:
An example of a systolic algorithm might be designed for matrix multiplication. One matrix is fed in a row at a time from the top of the array and is passed down the array, the other matrix is fed in a column at a time from the left hand side of the array and passes from left to right. Dummy values are then passed in until each processor has seen one whole row and one whole column. At this point, the result of the multiplication is stored in the array and can now be output a row or a column at a time, flowing down or across the array.Systolic arrays are arrays of DPUs which are connected to a small number of nearest neighbour DPUs in a mesh-like topology. DPUs perform a sequence of operations on data that flows between them. Because the traditional systolic array synthesis methods have been practiced by algebraic algorithms, only uniform arrays with only linear pipes can be obtained, so that the architectures are the same in all DPUs. The consequence is, that only applications with regular data dependencies can be implemented on classical systolic arrays. Like SIMD machines, clocked systolic arrays compute in "lock-step" with each processor undertaking alternate compute | communicate phases. But systolic arrays with asynchronous handshake between DPUs are called wavefront arrays.
Detailed description:
One well-known systolic array is Carnegie Mellon University's iWarp processor, which has been manufactured by Intel. An iWarp system has a linear array processor connected by data buses going in both directions.
History:
Systolic arrays (also known as wavefront processors), were first described by H. T. Kung and Charles E. Leiserson, who published the first paper describing systolic arrays in 1979. However, the first machine known to have used a similar technique was the Colossus Mark II in 1944.
Application example:
Polynomial evaluationHorner's rule for evaluating a polynomial is: y=(…(((an⋅x+an−1)⋅x+an−2)⋅x+an−3)⋅x+…+a1)⋅x+a0.
A linear systolic array in which the processors are arranged in pairs: one multiplies its input by x and passes the result to the right, the next adds aj and passes the result to the right.
Advantages and disadvantages:
Pros Faster than general purpose processors ScalableCons Expensive, due to low economy of scale Highly specialized, custom hardware is required and often application specific.
Not widely implemented Limited code base of programs and algorithms. (Not all algorithms can be implemented as systolic arrays. Often tricks are needed to map such algorithms on to a systolic array.)
Implementations:
Cisco PXF network processor is internally organized as systolic array.
Google’s TPU is also designed around a systolic array.
Paracel FDF4T TestFinder text search system Paracel FDF4G GeneMatcher Biological (DNA and Protein) search system Inferentia chip at Amazon Web Services MIT Eyeriss is a systolic array accelerator for convolutional neural networks. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Portable toilet**
Portable toilet:
A portable or mobile toilet (colloquial terms: thunderbox, porta-john or porta-potty) is any type of toilet that can be moved around, some by one person, some by mechanical equipment such as a truck and crane. Most types do not require any pre-existing services or infrastructure, such as sewerage, but are completely self-contained. The portable toilet is used in a variety of situations, for example in urban slums of developing countries, at festivals, for camping, on boats, on construction sites, and at film locations and large outdoor gatherings where there are no other facilities. Most portable toilets are unisex single units with privacy ensured by a simple lock on the door. Some portable toilets are small molded plastic or fiberglass portable rooms with a lockable door and a receptacle to catch the human excreta in a container. A portable toilet is not connected to a hole in the ground (like a pit latrine), nor to a septic tank, nor is it plumbed into a municipal system leading to a sewage treatment plant. The chemical toilet is probably the most well-known type of portable toilet, but other types also exist, such as urine-diversion dehydration toilets, composting toilets, container-based toilets, bucket toilets, freezing toilets and incineration toilets. A bucket toilet is a very simple type of portable toilet.
Types:
Chemical toilets A chemical toilet collects human excreta in a holding tank and uses chemicals to minimize the odors. These chemicals may either mask the odor or contain biocides that hinder odor-causing bacteria from multiplying, keeping the smell to a minimum. Chemical toilets include those on plane and trains (although many of these are now vacuum toilets), as well as much simpler ones.
Types:
Portable camping toilets A simpler type of portable toilet may be used in travel trailers (caravans, camper vans) and on small boats. They are also referred to as "cassette toilet" or "camping toilet", or under brand names that have become generic trademarks. The Oxford English Dictionary lists "Porta Potti" ("with arbitrary respelling") as "A proprietary name for: a portable chemical toilet, as used by campers", and gives mostly American examples from 1968. The OED gives this proprietary name a second meaning, "a small prefabricated unit containing a toilet, designed for easy transportation and temporary installation esp. outdoors", which Wikipedia covers under chemical toilet.
Types:
The other name common in British English is "Elsan", which dates back to 1925. According to the Camping and Caravanning Club, "Today you will often see campsites refer to their Chemical Disposal Points as Elsan Disposal Points because of the history and popularity of the brand." The Canal and River Trust uses both brand names, in lieu of any unbranded term.One colloquialism for these simple toilets is the "bucket and chuck it" system, although in fact they no longer resemble an open bucket (see bucket toilet). These are designed to be emptied into sanitary stations connected to the regular sewage system. These toilets are not to be confused with the types that are plumbed in to the vehicle and need to be pumped out at holding tank dump stations.
Types:
Urine-diversion dehydration toilets Portable urine-diversion dehydration toilets are self-contained dry toilets sometimes referred to as "mobile" or "stand-alone" units. They are identifiable by their one-piece molded plastic shells or, in the case of DIY versions, simple plywood box construction. Most users of self-contained UDDTs rely upon a post-treatment process to ensure pathogen reduction. This post-treatment may consist of long-term storage or addition to an existing or purpose-built compost pile or some combination thereof. A post-treatment step is unnecessary in the case of very modest seasonal use.
Types:
Others A commode chair (a chair enclosing a chamber pot) is a basic portable toilet that was used, for example, in 19th-century Europe.
History:
The close stool, built as an article of furniture, is one of the earliest forms of portable toilet. They can still be seen in historic house museums such as Sir George-Étienne Cartier National Historic Site in Old Montreal, Canada. The velvet upholstered close stool used by William III is on display at Hampton Court Palace; see Groom of the Stool.
History:
Early versions of the "Elsan chemical closet" ("closet" meaning a small room, see water closet, WC, and earth closet) were sold at Army & Navy Stores. Their use in World War II bomber aircraft is described at some length by the Bomber Command Museum of Canada; in brief, they were not popular with either the flying crew or the ground crew.African-Americans living under Jim Crow laws (i.e. before the Civil Rights Act of 1964) faced dangerous challenges. Public toilets were segregated by race, and many restaurants and gas stations refused to serve black people, so some travellers carried a portable toilet in the trunk of their car.Since 1974, Grand Canyon guides have used ammo boxes to defecate, according to the Museum of Northern Arizona in Flagstaff, Arizona.
Society and culture:
A slang term, now dated or historic, is a "thunder-box" (Oxford English Dictionary: "a portable commode; by extension, any lavatory"). The term was used particularly in British India; travel writer Stephen McClarence called it "a crude sort of colonial lavatory". One features to comic effect in Evelyn Waugh's novel Men at Arms: "If you must know, it's my thunderbox." ... He...dragged out the treasure, a brass-bound, oak cube... On the inside of the lid was a plaque bearing the embossed title Connolly's Chemical Closet. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Drag reduction system**
Drag reduction system:
In motor racing, the drag reduction system (DRS) is a form of driver-adjustable bodywork aimed at reducing aerodynamic drag in order to increase top speed and promote overtaking. It is an adjustable rear wing of the car, which moves in response to driver commands. DRS often comes with conditions, such as the requirement in Formula 1 that the pursuing car must be within one second (when both cars cross the detection point) for DRS to be activated.
Drag reduction system:
DRS was introduced in Formula One in 2011. The use of DRS is an exception to the rule banning any moving parts whose primary purpose is to affect the aerodynamics of the car. The system is also used in the Formula Renault 3.5 since 2012, Deutsche Tourenwagen Masters since 2013, Super Formula since 2014, GP2 Series later FIA Formula 2 Championship since 2015, GP3 Series later FIA Formula 3 Championship since 2017. An adjustable wing was also used by the Nissan DeltaWing at the 2012 24 Hours of Le Mans, although with free usage.
Formula One:
In Formula One, the DRS opens an adjustable flap on the rear wing of the car, in order to reduce drag, thus giving a pursuing car an overtaking advantage over the car in front. The FIA estimate the speed increase to be between 10–12 km/h (6.2–7.5 mph) by the end of the activation zone, while others, such as technical staff at racecar-engineering.com, cite a much lower figure of 4–5 km/h (2.5–3.1 mph). When the DRS is deactivated or closed, it increases downforce, giving better cornering.
Formula One:
The device can only be used during a race after two racing laps have been completed, and when the pursuing car enters a designated "activation" zone defined by the FIA. This also includes having to wait 2 laps after a safety car restart.
Formula One:
In 2011, the FIA increased the number of DRS zones to two on some circuits featuring multiple long straights. In Valencia and in Montreal, two zones were endorsed on consecutive long straights, while in Monza and in Buddh, two zones were created on separate parts of the circuit. Two zones had originally been planned for every race with multiple long straights from Montreal onwards (depending on Montreal/Valencia success), but this was not implemented. However, at the penultimate round of the 2011 season, two zones on consecutive long straights saw a return at Yas Marina.
Formula One:
When usage of the DRS remained legal for the 2012 season, a second zone was added to the opening round's track in Melbourne. A third DRS zone was added during 2018 and 2019 seasons in Australia, Bahrain, Canada, Austria, Singapore, and Mexico. In the 2022 season, a fourth zone was initially added for the track in Melbourne, after the circuit redevelopment, before being removed for safety reasons. In the 2023 season the zone was re-added. Bahrain, Jeddah, Melbourne, Baku and Miami had their DRS zones adjusted based on whether the FIA deemed DRS made overtaking at these five circuits too easy or too hard in 2022.
Formula One:
Functional description The horizontal elements of the rear wing consist of the main plane and the flap. The DRS allows the flap to lift a maximum of 85 millimetres (3.3 in) from the fixed main plane. This reduces opposition (drag) to airflow against the wing and results in less downforce. In the absence of significant lateral forces (straight line), less downforce allows faster acceleration and potential top speed, unless limited by the top gear ratio and engine rev limiter. Sam Michael, sporting director of the McLaren team, believes that DRS in qualifying will be worth about half a second per lap.
Formula One:
The effectiveness of the DRS will vary from track to track and, to a lesser extent, from car to car. The system's effectiveness was reviewed in 2011 to see if overtaking could be made easier, but not to the extent that driver skill is sidelined. The effectiveness of DRS seems likely to be determined by the level of downforce at a given circuit (where the cars are in low drag trim at circuits like Monza, the effects may be smaller), length of the activation zone, and characteristics of the track immediately after the DRS zone.
Formula One:
Rules on use Use of DRS is restricted by the F1 rules; it is permitted only when both: The following car is within one second of the car to be overtaken, which may be a car being lapped. The FIA may alter this parameter, race by race.
Formula One:
The following car is in an overtaking zone as defined by the FIA before the race (commonly known as the DRS zone).Further: The system may not be activated on the first two laps after the race start, restart, or a safety car deployment, for example, as was the case of the 2021 Belgian Grand Prix, during which no driver could have activated DRS because the entire race took place behind a safety car, before being terminated due to bad weather.
Formula One:
The system cannot be used by the defending driver, unless within one second of another car in front.
Formula One:
The system may not be enabled if racing conditions are deemed dangerous by the race director, such as rain, as was the case at the 2011 Canadian Grand Prix.A dashboard light notifies the driver when the system is enabled (the driver can also see the system deploy in his wing mirrors). The system is deactivated when the driver releases the button or uses the brakes.
Formula One:
There are lines on the track to show the area where the one-second proximity is being detected (the detection point) and a line later on the track (the activation point), along with a sign vertically marked "DRS" where the DRS zone itself begins.
Reception:
There has been a mixed reaction to the introduction of DRS in Formula One amongst both fans and drivers. Some believe that this is the solution to the lack of overtaking in F1 in recent years while others believe this has made overtaking too easy. Former Formula One and Team Penske IndyCar Series driver Juan Pablo Montoya described it as "like giving Picasso Photoshop". The principal argument for the opponents of DRS is that the driver in front does not have an equal chance of defending his position because they are not allowed to deploy DRS to defend. The tightening up on the rules for a leading driver defending their position has added to this controversy. In 2018, then-Scuderia Ferrari driver Sebastian Vettel stated that he preferred throwing bananas Mario Kart-style over the use of DRS, arguing that it's "artificial".
Road car use:
The McLaren P1 coupé is the first road car to have incorporated the F1-style rear wing Drag Reduction Systems. Porsche 911 (992) GT3 RS later followed suit by the introduction of the same system in 2022. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cohesive bandage**
Cohesive bandage:
A self-adhering bandage or cohesive bandage (coban) is a type of bandage or wrap that coheres to itself but does not adhere well to other surfaces. "Coban" by 3M is commonly used as a wrap on limbs because it will stick to itself and not loosen. Due to its elastic qualities, coban is often used as a compression bandage.It is used both on humans and animals. For animal use, it is marketed under a variety of trade names such as "Vetrap" by 3M. It is commonly used on horses and other animals because it will not stick to hair so it is easily removed. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Convolution**
Convolution:
In mathematics (in particular, functional analysis), convolution is a mathematical operation on two functions (f and g) that produces a third function ( f∗g ) that expresses how the shape of one is modified by the other. The term convolution refers to both the result function and to the process of computing it. It is defined as the integral of the product of the two functions after one is reflected about the y-axis and shifted. The choice of which function is reflected and shifted before the integral does not change the integral result (see commutativity). The integral is evaluated for all values of shift, producing the convolution function.
Convolution:
Some features of convolution are similar to cross-correlation: for real-valued functions, of a continuous or discrete variable, convolution ( f∗g ) differs from cross-correlation ( f⋆g ) only in that either f(x) or g(x) is reflected about the y-axis in convolution; thus it is a cross-correlation of g(−x) and f(x), or f(−x) and g(x). For complex-valued functions, the cross-correlation operator is the adjoint of the convolution operator.
Convolution:
Convolution has applications that include probability, statistics, acoustics, spectroscopy, signal processing and image processing, geophysics, engineering, physics, computer vision and differential equations.The convolution can be defined for functions on Euclidean space and other groups (as algebraic structures). For example, periodic functions, such as the discrete-time Fourier transform, can be defined on a circle and convolved by periodic convolution. (See row 18 at DTFT § Properties.) A discrete convolution can be defined for functions on the set of integers.
Convolution:
Generalizations of convolution have applications in the field of numerical analysis and numerical linear algebra, and in the design and implementation of finite impulse response filters in signal processing.Computing the inverse of the convolution operation is known as deconvolution.
Definition:
The convolution of f and g is written f∗g, denoting the operator with the symbol ∗. It is defined as the integral of the product of the two functions after one is reflected about the y-axis and shifted. As such, it is a particular kind of integral transform: := ∫−∞∞f(τ)g(t−τ)dτ.
An equivalent definition is (see commutativity): := ∫−∞∞f(t−τ)g(τ)dτ.
Definition:
While the symbol t is used above, it need not represent the time domain. At each t, the convolution formula can be described as the area under the function f(τ) weighted by the function g(−τ) shifted by the amount t. As t changes, the weighting function g(t − τ) emphasizes different parts of the input function f(τ); If t is a positive value, then g(t − τ) is equal to g(−τ) that slides or is shifted along the τ -axis toward the right (toward +∞) by the amount of t, while if t is a negative value, then g(t − τ) is equal to g(−τ) that slides or is shifted toward the left (toward -∞) by the amount of |t|.
Definition:
For functions f, g supported on only [0, ∞] (i.e., zero for negative arguments), the integration limits can be truncated, resulting in: for f,g:[0,∞)→R.
For the multi-dimensional formulation of convolution, see domain of definition (below).
Notation A common engineering notational convention is: := ∫−∞∞f(τ)g(t−τ)dτ⏟(f∗g)(t), which has to be interpreted carefully to avoid confusion. For instance, f(t)∗g(t − t0) is equivalent to (f∗g)(t − t0), but f(t − t0)∗g(t − t0) is in fact equivalent to (f∗g)(t − 2t0).
Definition:
Relations with other transforms Given two functions f(t) and g(t) with bilateral Laplace transforms (two-sided Laplace transform) F(s)=∫−∞∞e−suf(u)du and G(s)=∫−∞∞e−svg(v)dv respectively, the convolution operation (f∗g)(t) can be defined as the inverse Laplace transform of the product of F(s) and G(s) . More precisely, F(s)⋅G(s)=∫−∞∞e−suf(u)du⋅∫−∞∞e−svg(v)dv=∫−∞∞∫−∞∞e−s(u+v)f(u)g(v)dudv Let t=u+v such that F(s)⋅G(s)=∫−∞∞∫−∞∞e−stf(u)g(t−u)dudt=∫−∞∞e−st∫−∞∞f(u)g(t−u)du⏟(f∗g)(t)dt=∫−∞∞e−st(f∗g)(t)dt Note that F(s)⋅G(s) is the bilateral Laplace transform of (f∗g)(t) . A similar derivation can be done using the unilateral Laplace transform (one-sided Laplace transform).
Definition:
The convolution operation also describes the output (in terms of the input) of an important class of operations known as linear time-invariant (LTI). See LTI system theory for a derivation of convolution as the result of LTI constraints. In terms of the Fourier transforms of the input and output of an LTI operation, no new frequency components are created. The existing ones are only modified (amplitude and/or phase). In other words, the output transform is the pointwise product of the input transform with a third transform (known as a transfer function). See Convolution theorem for a derivation of that property of convolution. Conversely, convolution can be derived as the inverse Fourier transform of the pointwise product of two Fourier transforms.
Historical developments:
One of the earliest uses of the convolution integral appeared in D'Alembert's derivation of Taylor's theorem in Recherches sur différents points importants du système du monde, published in 1754.Also, an expression of the type: ∫f(u)⋅g(x−u)du is used by Sylvestre François Lacroix on page 505 of his book entitled Treatise on differences and series, which is the last of 3 volumes of the encyclopedic series: Traité du calcul différentiel et du calcul intégral, Chez Courcier, Paris, 1797–1800. Soon thereafter, convolution operations appear in the works of Pierre Simon Laplace, Jean-Baptiste Joseph Fourier, Siméon Denis Poisson, and others. The term itself did not come into wide use until the 1950s or 60s. Prior to that it was sometimes known as Faltung (which means folding in German), composition product, superposition integral, and Carson's integral. Yet it appears as early as 1903, though the definition is rather unfamiliar in older uses.The operation: ∫0tφ(s)ψ(t−s)ds,0≤t<∞, is a particular case of composition products considered by the Italian mathematician Vito Volterra in 1913.
Circular convolution:
When a function gT is periodic, with period T, then for functions, f, such that f ∗ gT exists, the convolution is also periodic and identical to: (f∗gT)(t)≡∫t0t0+T[∑k=−∞∞f(τ+kT)]gT(t−τ)dτ, where t0 is an arbitrary choice. The summation is called a periodic summation of the function f.
When gT is a periodic summation of another function, g, then f ∗ gT is known as a circular or cyclic convolution of f and g.
And if the periodic summation above is replaced by fT, the operation is called a periodic convolution of fT and gT.
Discrete convolution:
For complex-valued functions f, g defined on the set Z of integers, the discrete convolution of f and g is given by: (f∗g)[n]=∑m=−∞∞f[m]g[n−m], or equivalently (see commutativity) by: (f∗g)[n]=∑m=−∞∞f[n−m]g[m].
Discrete convolution:
The convolution of two finite sequences is defined by extending the sequences to finitely supported functions on the set of integers. When the sequences are the coefficients of two polynomials, then the coefficients of the ordinary product of the two polynomials are the convolution of the original two sequences. This is known as the Cauchy product of the coefficients of the sequences.
Discrete convolution:
Thus when g has finite support in the set {−M,−M+1,…,M−1,M} (representing, for instance, a finite impulse response), a finite summation may be used: (f∗g)[n]=∑m=−MMf[n−m]g[m].
Circular discrete convolution When a function gN is periodic, with period N, then for functions, f, such that f∗gN exists, the convolution is also periodic and identical to: (f∗gN)[n]≡∑m=0N−1(∑k=−∞∞f[m+kN])gN[n−m].
The summation on k is called a periodic summation of the function f.
If gN is a periodic summation of another function, g, then f∗gN is known as a circular convolution of f and g.
When the non-zero durations of both f and g are limited to the interval [0, N − 1], f∗gN reduces to these common forms: The notation (f ∗N g) for cyclic convolution denotes convolution over the cyclic group of integers modulo N.
Circular convolution arises most often in the context of fast convolution with a fast Fourier transform (FFT) algorithm.
Discrete convolution:
Fast convolution algorithms In many situations, discrete convolutions can be converted to circular convolutions so that fast transforms with a convolution property can be used to implement the computation. For example, convolution of digit sequences is the kernel operation in multiplication of multi-digit numbers, which can therefore be efficiently implemented with transform techniques (Knuth 1997, §4.3.3.C; von zur Gathen & Gerhard 2003, §8.2).
Discrete convolution:
Eq.1 requires N arithmetic operations per output value and N2 operations for N outputs. That can be significantly reduced with any of several fast algorithms. Digital signal processing and other applications typically use fast convolution algorithms to reduce the cost of the convolution to O(N log N) complexity.
Discrete convolution:
The most common fast convolution algorithms use fast Fourier transform (FFT) algorithms via the circular convolution theorem. Specifically, the circular convolution of two finite-length sequences is found by taking an FFT of each sequence, multiplying pointwise, and then performing an inverse FFT. Convolutions of the type defined above are then efficiently implemented using that technique in conjunction with zero-extension and/or discarding portions of the output. Other fast convolution algorithms, such as the Schönhage–Strassen algorithm or the Mersenne transform, use fast Fourier transforms in other rings.
Discrete convolution:
If one sequence is much longer than the other, zero-extension of the shorter sequence and fast circular convolution is not the most computationally efficient method available. Instead, decomposing the longer sequence into blocks and convolving each block allows for faster algorithms such as the overlap–save method and overlap–add method. A hybrid convolution method that combines block and FIR algorithms allows for a zero input-output latency that is useful for real-time convolution computations.
Domain of definition:
The convolution of two complex-valued functions on Rd is itself a complex-valued function on Rd, defined by: (f∗g)(x)=∫Rdf(y)g(x−y)dy=∫Rdf(x−y)g(y)dy, and is well-defined only if f and g decay sufficiently rapidly at infinity in order for the integral to exist. Conditions for the existence of the convolution may be tricky, since a blow-up in g at infinity can be easily offset by sufficiently rapid decay in f. The question of existence thus may involve different conditions on f and g: Compactly supported functions If f and g are compactly supported continuous functions, then their convolution exists, and is also compactly supported and continuous (Hörmander 1983, Chapter 1). More generally, if either function (say f) is compactly supported and the other is locally integrable, then the convolution f∗g is well-defined and continuous.
Domain of definition:
Convolution of f and g is also well defined when both functions are locally square integrable on R and supported on an interval of the form [a, +∞) (or both supported on [−∞, a]).
Domain of definition:
Integrable functions The convolution of f and g exists if f and g are both Lebesgue integrable functions in L1(Rd), and in this case f∗g is also integrable (Stein & Weiss 1971, Theorem 1.3). This is a consequence of Tonelli's theorem. This is also true for functions in L1, under the discrete convolution, or more generally for the convolution on any group.
Domain of definition:
Likewise, if f ∈ L1(Rd) and g ∈ Lp(Rd) where 1 ≤ p ≤ ∞, then f∗g ∈ Lp(Rd), and ‖f∗g‖p≤‖f‖1‖g‖p.
In the particular case p = 1, this shows that L1 is a Banach algebra under the convolution (and equality of the two sides holds if f and g are non-negative almost everywhere).
More generally, Young's inequality implies that the convolution is a continuous bilinear map between suitable Lp spaces. Specifically, if 1 ≤ p, q, r ≤ ∞ satisfy: 1p+1q=1r+1, then ‖f∗g‖r≤‖f‖p‖g‖q,f∈Lp,g∈Lq, so that the convolution is a continuous bilinear mapping from Lp×Lq to Lr.
The Young inequality for convolution is also true in other contexts (circle group, convolution on Z). The preceding inequality is not sharp on the real line: when 1 < p, q, r < ∞, there exists a constant Bp,q < 1 such that: ‖f∗g‖r≤Bp,q‖f‖p‖g‖q,f∈Lp,g∈Lq.
The optimal value of Bp,q was discovered in 1975 and independently in 1976, see Brascamp–Lieb inequality.
A stronger estimate is true provided 1 < p, q, r < ∞: ‖f∗g‖r≤Cp,q‖f‖p‖g‖q,w where ‖g‖q,w is the weak Lq norm. Convolution also defines a bilinear continuous map Lp,w×Lq,w→Lr,w for 1<p,q,r<∞ , owing to the weak Young inequality: ‖f∗g‖r,w≤Cp,q‖f‖p,w‖g‖r,w.
Domain of definition:
Functions of rapid decay In addition to compactly supported functions and integrable functions, functions that have sufficiently rapid decay at infinity can also be convolved. An important feature of the convolution is that if f and g both decay rapidly, then f∗g also decays rapidly. In particular, if f and g are rapidly decreasing functions, then so is the convolution f∗g. Combined with the fact that convolution commutes with differentiation (see #Properties), it follows that the class of Schwartz functions is closed under convolution (Stein & Weiss 1971, Theorem 3.3).
Domain of definition:
Distributions If f is a smooth function that is compactly supported and g is a distribution, then f∗g is a smooth function defined by ∫Rdf(y)g(x−y)dy=(f∗g)(x)∈C∞(Rd).
More generally, it is possible to extend the definition of the convolution in a unique way with φ the same as f above, so that the associative law f∗(g∗φ)=(f∗g)∗φ remains valid in the case where f is a distribution, and g a compactly supported distribution (Hörmander 1983, §4.2).
Measures The convolution of any two Borel measures μ and ν of bounded variation is the measure μ∗ν defined by (Rudin 1962) ∫Rdf(x)d(μ∗ν)(x)=∫Rd∫Rdf(x+y)dμ(x)dν(y).
In particular, (μ∗ν)(A)=∫Rd×Rd1A(x+y)d(μ×ν)(x,y), where A⊂Rd is a measurable set and 1A is the indicator function of A This agrees with the convolution defined above when μ and ν are regarded as distributions, as well as the convolution of L1 functions when μ and ν are absolutely continuous with respect to the Lebesgue measure.
The convolution of measures also satisfies the following version of Young's inequality ‖μ∗ν‖≤‖μ‖‖ν‖ where the norm is the total variation of a measure. Because the space of measures of bounded variation is a Banach space, convolution of measures can be treated with standard methods of functional analysis that may not apply for the convolution of distributions.
Properties:
Algebraic properties The convolution defines a product on the linear space of integrable functions. This product satisfies the following algebraic properties, which formally mean that the space of integrable functions with the product given by convolution is a commutative associative algebra without identity (Strichartz 1994, §3.3). Other linear spaces of functions, such as the space of continuous functions of compact support, are closed under the convolution, and so also form commutative associative algebras.
Properties:
Commutativity Proof: By definition: Changing the variable of integration to u=t−τ the result follows.Associativity Proof: This follows from using Fubini's theorem (i.e., double integrals can be evaluated as iterated integrals in either order).Distributivity Proof: This follows from linearity of the integral.Associativity with scalar multiplication for any real (or complex) number a .Multiplicative identity No algebra of functions possesses an identity for the convolution. The lack of identity is typically not a major inconvenience, since most collections of functions on which the convolution is performed can be convolved with a delta distribution (a unitary impulse, centered at zero) or, at the very least (as is the case of L1) admit approximations to the identity. The linear space of compactly supported distributions does, however, admit an identity under the convolution. Specifically, where δ is the delta distribution.Inverse element Some distributions S have an inverse element S−1 for the convolution which then must satisfy from which an explicit formula for S−1 may be obtained.The set of invertible distributions forms an abelian group under the convolution.Complex conjugation Relationship with differentiation Proof: (f∗g)′=ddt∫−∞∞f(τ)g(t−τ)dτ=∫−∞∞f(τ)∂∂tg(t−τ)dτ=∫−∞∞f(τ)g′(t−τ)dτ=f∗g′.
Properties:
Relationship with integration If {\textstyle F(t)=\int _{-\infty }^{t}f(\tau )d\tau ,} and {\textstyle G(t)=\int _{-\infty }^{t}g(\tau )\,d\tau ,} then Integration If f and g are integrable functions, then the integral of their convolution on the whole space is simply obtained as the product of their integrals: ∫Rd(f∗g)(x)dx=(∫Rdf(x)dx)(∫Rdg(x)dx).
This follows from Fubini's theorem. The same result holds if f and g are only assumed to be nonnegative measurable functions, by Tonelli's theorem.
Differentiation In the one-variable case, ddx(f∗g)=dfdx∗g=f∗dgdx where ddx is the derivative. More generally, in the case of functions of several variables, an analogous formula holds with the partial derivative: ∂∂xi(f∗g)=∂f∂xi∗g=f∗∂g∂xi.
A particular consequence of this is that the convolution can be viewed as a "smoothing" operation: the convolution of f and g is differentiable as many times as f and g are in total.
These identities hold under the precise condition that f and g are absolutely integrable and at least one of them has an absolutely integrable (L1) weak derivative, as a consequence of Young's convolution inequality. For instance, when f is continuously differentiable with compact support, and g is an arbitrary locally integrable function, ddx(f∗g)=dfdx∗g.
These identities also hold much more broadly in the sense of tempered distributions if one of f or g is a rapidly decreasing tempered distribution, a compactly supported tempered distribution or a Schwartz function and the other is a tempered distribution. On the other hand, two positive integrable and infinitely differentiable functions may have a nowhere continuous convolution.
In the discrete case, the difference operator D f(n) = f(n + 1) − f(n) satisfies an analogous relationship: D(f∗g)=(Df)∗g=f∗(Dg).
Convolution theorem The convolution theorem states that F{f∗g}=F{f}⋅F{g} where F{f} denotes the Fourier transform of f Convolution in other types of transformations Versions of this theorem also hold for the Laplace transform, two-sided Laplace transform, Z-transform and Mellin transform.
Convolution on matrices If W is the Fourier transform matrix, then W(C(1)x∗C(2)y)=(WC(1)∙WC(2))(x⊗y)=WC(1)x∘WC(2)y ,where ∙ is face-splitting product, ⊗ denotes Kronecker product, ∘ denotes Hadamard product (this result is an evolving of count sketch properties).
Translational equivariance The convolution commutes with translations, meaning that τx(f∗g)=(τxf)∗g=f∗(τxg) where τxf is the translation of the function f by x defined by (τxf)(y)=f(y−x).
If f is a Schwartz function, then τxf is the convolution with a translated Dirac delta function τxf = f ∗ τx δ. So translation invariance of the convolution of Schwartz functions is a consequence of the associativity of convolution.
Properties:
Furthermore, under certain conditions, convolution is the most general translation invariant operation. Informally speaking, the following holds Suppose that S is a bounded linear operator acting on functions which commutes with translations: S(τxf) = τx(Sf) for all x. Then S is given as convolution with a function (or distribution) gS; that is Sf = gS ∗ f.Thus some translation invariant operations can be represented as convolution. Convolutions play an important role in the study of time-invariant systems, and especially LTI system theory. The representing function gS is the impulse response of the transformation S.
Properties:
A more precise version of the theorem quoted above requires specifying the class of functions on which the convolution is defined, and also requires assuming in addition that S must be a continuous linear operator with respect to the appropriate topology. It is known, for instance, that every continuous translation invariant continuous linear operator on L1 is the convolution with a finite Borel measure. More generally, every continuous translation invariant continuous linear operator on Lp for 1 ≤ p < ∞ is the convolution with a tempered distribution whose Fourier transform is bounded. To wit, they are all given by bounded Fourier multipliers.
Convolutions on groups:
If G is a suitable group endowed with a measure λ, and if f and g are real or complex valued integrable functions on G, then we can define their convolution by (f∗g)(x)=∫Gf(y)g(y−1x)dλ(y).
Convolutions on groups:
It is not commutative in general. In typical cases of interest G is a locally compact Hausdorff topological group and λ is a (left-) Haar measure. In that case, unless G is unimodular, the convolution defined in this way is not the same as {\textstyle \int f\left(xy^{-1}\right)g(y)\,d\lambda (y)} . The preference of one over the other is made so that convolution with a fixed function g commutes with left translation in the group: Lh(f∗g)=(Lhf)∗g.
Convolutions on groups:
Furthermore, the convention is also required for consistency with the definition of the convolution of measures given below. However, with a right instead of a left Haar measure, the latter integral is preferred over the former.
On locally compact abelian groups, a version of the convolution theorem holds: the Fourier transform of a convolution is the pointwise product of the Fourier transforms. The circle group T with the Lebesgue measure is an immediate example. For a fixed g in L1(T), we have the following familiar operator acting on the Hilbert space L2(T): Tf(x)=12π∫Tf(y)g(x−y)dy.
The operator T is compact. A direct calculation shows that its adjoint T* is convolution with g¯(−y).
Convolutions on groups:
By the commutativity property cited above, T is normal: T* T = TT* . Also, T commutes with the translation operators. Consider the family S of operators consisting of all such convolutions and the translation operators. Then S is a commuting family of normal operators. According to spectral theory, there exists an orthonormal basis {hk} that simultaneously diagonalizes S. This characterizes convolutions on the circle. Specifically, we have hk(x)=eikx,k∈Z, which are precisely the characters of T. Each convolution is a compact multiplication operator in this basis. This can be viewed as a version of the convolution theorem discussed above.
Convolutions on groups:
A discrete example is a finite cyclic group of order n. Convolution operators are here represented by circulant matrices, and can be diagonalized by the discrete Fourier transform.
A similar result holds for compact groups (not necessarily abelian): the matrix coefficients of finite-dimensional unitary representations form an orthonormal basis in L2 by the Peter–Weyl theorem, and an analog of the convolution theorem continues to hold, along with many other aspects of harmonic analysis that depend on the Fourier transform.
Convolution of measures:
Let G be a (multiplicatively written) topological group.
If μ and ν are finite Borel measures on G, then their convolution μ∗ν is defined as the pushforward measure of the group action and can be written as (μ∗ν)(E)=∬1E(xy)dμ(x)dν(y) for each measurable subset E of G. The convolution is also a finite measure, whose total variation satisfies ‖μ∗ν‖≤‖μ‖‖ν‖.
In the case when G is locally compact with (left-)Haar measure λ, and μ and ν are absolutely continuous with respect to a λ, so that each has a density function, then the convolution μ∗ν is also absolutely continuous, and its density function is just the convolution of the two separate density functions.
If μ and ν are probability measures on the topological group (R,+), then the convolution μ∗ν is the probability distribution of the sum X + Y of two independent random variables X and Y whose respective distributions are μ and ν.
Infimal convolution:
In convex analysis, the infimal convolution of proper (not identically +∞ ) convex functions f1,…,fm on Rn is defined by: It can be shown that the infimal convolution of convex functions is convex. Furthermore, it satisfies an identity analogous to that of the Fourier transform of a traditional convolution, with the role of the Fourier transform is played instead by the Legendre transform: We have:
Bialgebras:
Let (X, Δ, ∇, ε, η) be a bialgebra with comultiplication Δ, multiplication ∇, unit η, and counit ε. The convolution is a product defined on the endomorphism algebra End(X) as follows. Let φ, ψ ∈ End(X), that is, φ, ψ: X → X are functions that respect all algebraic structure of X, then the convolution φ∗ψ is defined as the composition X→ΔX⊗X→ϕ⊗ψX⊗X→∇X.
Bialgebras:
The convolution appears notably in the definition of Hopf algebras (Kassel 1995, §III.3). A bialgebra is a Hopf algebra if and only if it has an antipode: an endomorphism S such that id id X∗S=η∘ε.
Applications:
Convolution and related operations are found in many applications in science, engineering and mathematics.
Convolutional neural networks apply multiple cascaded convolution kernels with applications in machine vision and artificial intelligence. Though these are actually cross-correlations rather than convolutions in most cases.
In non-neural-network-based image processing In digital image processing convolutional filtering plays an important role in many important algorithms in edge detection and related processes (see Kernel (image processing)) In optics, an out-of-focus photograph is a convolution of the sharp image with a lens function. The photographic term for this is bokeh.
In image processing applications such as adding blurring.
In digital data processing In analytical chemistry, Savitzky–Golay smoothing filters are used for the analysis of spectroscopic data. They can improve signal-to-noise ratio with minimal distortion of the spectra In statistics, a weighted moving average is a convolution.
In acoustics, reverberation is the convolution of the original sound with echoes from objects surrounding the sound source.
In digital signal processing, convolution is used to map the impulse response of a real room on a digital audio signal.
In electronic music convolution is the imposition of a spectral or rhythmic structure on a sound. Often this envelope or structure is taken from another sound. The convolution of two signals is the filtering of one through the other.
Applications:
In electrical engineering, the convolution of one function (the input signal) with a second function (the impulse response) gives the output of a linear time-invariant system (LTI). At any given moment, the output is an accumulated effect of all the prior values of the input function, with the most recent values typically having the most influence (expressed as a multiplicative factor). The impulse response function provides that factor as a function of the elapsed time since each input value occurred.
Applications:
In physics, wherever there is a linear system with a "superposition principle", a convolution operation makes an appearance. For instance, in spectroscopy line broadening due to the Doppler effect on its own gives a Gaussian spectral line shape and collision broadening alone gives a Lorentzian line shape. When both effects are operative, the line shape is a convolution of Gaussian and Lorentzian, a Voigt function.
Applications:
In time-resolved fluorescence spectroscopy, the excitation signal can be treated as a chain of delta pulses, and the measured fluorescence is a sum of exponential decays from each delta pulse.
In computational fluid dynamics, the large eddy simulation (LES) turbulence model uses the convolution operation to lower the range of length scales necessary in computation thereby reducing computational cost.
In probability theory, the probability distribution of the sum of two independent random variables is the convolution of their individual distributions.
In kernel density estimation, a distribution is estimated from sample points by convolution with a kernel, such as an isotropic Gaussian.
In radiotherapy treatment planning systems, most part of all modern codes of calculation applies a convolution-superposition algorithm.
In structural reliability, the reliability index can be defined based on the convolution theorem.
The definition of reliability index for limit state functions with nonnormal distributions can be established corresponding to the joint distribution function. In fact, the joint distribution function can be obtained using the convolution theory.
Applications:
In Smoothed-particle hydrodynamics, simulations of fluid dynamics are calculated using particles, each with surrounding kernels. For any given particle i , some physical quantity Ai is calculated as a convolution of Aj with a weighting function, where j denotes the neighbors of particle i : those that are located within its kernel. The convolution is approximated as a summation over each neighbor.
Applications:
In Fractional calculus convolution is instrumental in various definitions of fractional integral and fractional derivative. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Single-track road**
Single-track road:
A single-track road or one-lane road is a road that permits two-way travel but is not wide enough in most places to allow vehicles to pass one another (although sometimes two compact cars can pass). This kind of road is common in rural areas across the United Kingdom and elsewhere. To accommodate two-way traffic, many single-track roads, especially those officially designated as such, are provided with passing places (United Kingdom) or pullouts or turnouts (United States), or simply wide spots in the road, which may be scarcely longer than a typical car using the road. The distance between passing places varies considerably, depending on the terrain and the volume of traffic on the road. The railway equivalent for passing places are passing loops.
In Scotland:
The term is widely used in Scotland, particularly the Highlands, to describe such roads. Passing places are generally marked with a diamond-shaped white sign with the words "passing place" on it. New signs tend to be square rather than diamond-shaped, as diamond signs are also used for instructions to tram drivers in cities. On some roads, especially in Argyll and Bute, passing places are marked with black-and-white-striped posts. Signs remind drivers of slower vehicles to pull over into a passing place (or opposite it, if it is on the opposite side of the road) to let following vehicles pass, and most drivers oblige. The same system is found very occasionally in rural England and Wales, as well as Sai Kung District in the New Territories. Sometimes two small vehicles can pass one another at a place other than a designated passing place.
In Scotland:
Some A-class and B-class roads in the Highlands are still single-track, although many sections have been widened for the sake of faster travel. In 2009, the A830 "Road to the Isles" and A851 on the Isle of Skye have had their single-track sections replaced with higher-quality single-carriageway road.
In mountains:
In remote backcountry areas around the world, particularly in mountains, many roads are single-track and unmarked. These include many U.S. Forest Service and logging roads in the United States. In Peru, the second of two overland transportation routes between Cuzco and Madre de Dios Region, a 300 km heavy-truck route, is a single-track road of gravel and dirt.
In mountains:
When practical, it is usually considered better for the vehicle going downhill to yield the right of way by stopping at a wide spot. The reason seems to be that it may be harder for the vehicle going up to get started again. At least in California, it is also the vehicle going downhill that must back up, if it is too late to stop at a wide spot.
Types:
Chicanes Chicanes are often placed on residential streets as a more aesthetic means to slow down cars.
One-lane passages Sometimes, for budget reasons, and where traffic is fairly low, bridges exist as single-track corridors. Tunnels in remote areas can also be one lane when the tunnel is short and traffic is low, when building a hill or blasting away the mountain is too cost-prohibitive.
One-way single-track roads Single-track roads also exist as one-way stretches. Exit and entrance ramps for freeways and motorways are among common examples of one-way single-track roads.
Private single-track roads The most common example of private single-track roads are long driveways of rural properties such as country houses and farm property.
Types:
Ice roads The mountain passes on the Dalton Highway in Alaska have a rule where goods-carrying northbound truck traffic has the right of way, while returning southbound traffic has to stop, as mentioned on Ice Road Truckers. The reason behind this procedure is that traffic going north is in somewhat of a hurry to deliver equipment to Deadhorse, Prudhoe Bay, and the drill site over the frozen Arctic Ocean.
Types:
Temporary one-lane restrictions When reconstruction is being done on two-lane highways where traffic is moderately heavy, a worker will often stand at each end of the construction zone, holding a sign with "SLOW" or "GO" written on one side and "STOP" on the reverse. The workers, who communicate through yelling, hand gestures, or radio, will periodically reverse their signs to allow time for traffic to flow in each direction. A modification of this for roadways that have heavier traffic volumes is to maintain one direction on the existing roadway, and detour the other, thus not requiring the use of flaggers. An example of this is the M-89 reconstruction project in Plainwell, Michigan, where westbound traffic is detoured via county roads around town.
User etiquette:
If lines of sight are long, and both drivers are familiar with the road, vehicles heading towards each other can adjust their speed so as to arrive at a wide spot at the same time and pass slowly, avoiding the need for either vehicle to stop.
When two vehicles meet head-on, generally the drivers confer to decide in which direction lies the closest wide spot, and together they travel there, the lead vehicle necessarily in reverse gear.
User etiquette:
In Scotland, and places like the Isle of Man most drivers are accustomed to single-track roads. When opposing traffic is encountered, the first driver to reach the nearest passing place pulls over, no matter which side, and flashes the headlights to signal the other car to proceed forward. It is customary for both drivers to then acknowledge each other with a wave as they pass. At night, both drivers acknowledge each other by flashing their off-side direction indicators headlights immediately before or as they pass. It is extremely dangerous to flash headlights at close proximity on narrow unlit country roads at night as this affects drivers' night vision.
User etiquette:
Usually when there is a brief one-lane bottleneck of a two-lane road, traffic will usually yield to oncoming traffic already in the bottleneck. One-lane single-track roads usually have no conflict.
User etiquette:
In the United States, if the situation permits, both vehicles will pull off the road slightly and pass in this manner. Although saving time, this process can cause ruts and erosion along the edge of the road. For this reason, single track roads are generally used in places with very low traffic volumes, though one-lane stop-gap measures will have a STOP and YIELD on a sign construction workers flip.
User etiquette:
If there are no passing places or wide parts of the road then the start of the road is considered as the passing place. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**WAY-163909**
WAY-163909:
WAY-163,909 is a drug which acts as a potent and reasonably selective agonist for the serotonin 5-HT2C receptor. It has antipsychotic-like effects in animal models, and has been used to study the role of the 5-HT2C receptor subtype in the action of addictive drugs such as nicotine and methamphetamine. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Barrow's inequality**
Barrow's inequality:
In geometry, Barrow's inequality is an inequality relating the distances between an arbitrary point within a triangle, the vertices of the triangle, and certain points on the sides of the triangle. It is named after David Francis Barrow.
Statement:
Let P be an arbitrary point inside the triangle ABC. From P and ABC, define U, V, and W as the points where the angle bisectors of BPC, CPA, and APB intersect the sides BC, CA, AB, respectively. Then Barrow's inequality states that PA+PB+PC≥2(PU+PV+PW), with equality holding only in the case of an equilateral triangle and P is the center of the triangle.
Generalisation:
Barrow's inequality can be extended to convex polygons. For a convex polygon with vertices A1,A2,…,An let P be an inner point and Q1,Q2,…,Qn the intersections of the angle bisectors of ∠A1PA2,…,∠An−1PAn,∠AnPA1 with the associated polygon sides A1A2,…,An−1An,AnA1 , then the following inequality holds: sec (πn)∑k=1n|PQk| Here sec (x) denotes the secant function. For the triangle case n=3 the inequality becomes Barrow's inequality due to sec (π3)=2
History:
Barrow's inequality strengthens the Erdős–Mordell inequality, which has identical form except with PU, PV, and PW replaced by the three distances of P from the triangle's sides. It is named after David Francis Barrow. Barrow's proof of this inequality was published in 1937, as his solution to a problem posed in the American Mathematical Monthly of proving the Erdős–Mordell inequality. This result was named "Barrow's inequality" as early as 1961.A simpler proof was later given by Louis J. Mordell. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**String quintet repertoire**
String quintet repertoire:
The string quintet normally comprises the four instruments of the standard string quartet (2 violins, viola, and cello), plus one additional instrument. This additional instrument may be a viola, cello or double bass. Of these three different combinations, the string quintet with a second viola has the widest repertoire and may be referred to as the standard string quintet. The other two combinations have far fewer important works, though the combination with two cellos includes the string quintet by Schubert, which is widely considered the greatest of all string quintets.
String quintet repertoire:
Ordering in each section is by surname of composer. These lists should be complete for major composers and their string quintets. For secondary or minor composers, the lists are not exhaustive but those shown may be taken as representative examples. For recent or living composers, no attempt has been made at completeness.
"Viola" quintets:
String quintets with 2 violins, 2 violas and cello Arnold Bax (1883-1953) String Quintet in G (1908) Lyrical Interlude (1922) Ludwig van Beethoven (1770-1827) String Quintet in E flat, Op. 4 (1792-3; 1795–6) String Quintet in C major, Op. 29 (1801) String Quintet in C minor, Op. 104 (1793-5; 1817) Luigi Boccherini (1743-1805) String Quintet Op. 60 No. 1 in C major, G 391 (1801) String Quintet Op. 60 No. 2 in B flat major, G 392 (1801) String Quintet Op. 60 No. 3 in A major, G 393 (1801) String Quintet Op. 60 No. 4 in E flat major, G 394 (1801; lost) String Quintet Op. 60 No. 5 in G major, G 395 (1801) String Quintet Op. 60 No. 6 in F major, G 396 (1801) String Quintet Op. 62 No. 1 in C major, G 397 (1802) String Quintet Op. 62 No. 2 in E flat major, G 398 (1802) String Quintet Op. 62 No. 3 in F major, G 399 (1802) String Quintet Op. 62 No. 4 in B flat major, G 400 (1802) String Quintet Op. 62 No. 5 in D major, G 401 (1802) String Quintet Op. 62 No. 6 in E major, G 402 (1802) Also 12 further quintets arranged from piano quintets Johannes Brahms (1833-1897) String Quintet No. 1 in F major, Op. 88 (1883) String Quintet No. 2 in G major, Op. 111 (1891) Frank Bridge (1879-1941) String Quintet in E minor, H 7 (1901) Benjamin Britten (1913-1976) Phantasy Quintet (1932) Max Bruch (1838-1920) String Quintet No. 1 in A minor (1918) String Quintet No. 2 in E flat major (1918) Anton Bruckner (1824-1896) String Quintet in F major, WAB 112 (1878-9) Intermezzo for String Quintet, WAB 113 (1879) Franz Danzi (1763-1826) String Quintet in E flat major, op. 66 no. 1 (1823-4) String Quintet in F minor, op. 66 no. 2 (1823-4) String Quintet in A major, op. 66 no. 3 (1823-4) Gaetano Donizetti (1797-1848) Allegro in C major Antonín Dvořák (1841-1904) String Quintet in A minor, Op. 1 (1861) String Quintet in E-flat major, Op. 97 (1893) François-Joseph Fétis (1784-1871) String Quintet no. 1 in A minor (1860) String Quintet no. 2 (1862) String Quintet no. 3 (1862) Niels Gade (1817-1890) String Quintet in E minor, op. 8 (1845) Joseph Haydn (1732-1809) Divertimento in G major, Hob.II:2 (c. 1753) Michael Haydn (1737-1806) Quintet in C major, MH 187 Quintet in B flat major, MH 412 Quintet in F major, MH 367 Quintet in F major, MH 411 Quintet in G major, MH 189 Heinrich von Herzogenberg (1843-1900) String Quintet in C minor, op. 77 (1892) Felix Mendelssohn (1809-1847) String Quintet No. 1 in A major, op. 18 (1826; 1832) Minuet in F sharp minor (1826) String Quintet No. 2 in B flat major, op. 87 (1845) Wolfgang Amadeus Mozart (1756-1791) String Quintet in B-flat, K. 174 (1773) String Quintet in C major, K. 515 (1787) String Quintet in G minor, K. 516 (1787) String Quintet in C minor, K. 406/516b (1782; c. 1788) String Quintet in D major, K. 593 (1790) String Quintet in E-flat major, K. 614 (1791) Carl Nielsen (1865-1931) String Quintet in G major, FS 5 (1888) George Onslow (1784-1853) Three string quintets Three further string quintets with two versions, either for 2 violins, 2 violas and cello or for 2 violins, viola and 2 cellos Sir Hubert Parry (1848-1918) String Quintet in E flat major (1883-4) Anton Reicha (1770-1836) Seven string quintets Ferdinand Ries (1784-1838) Five string quintets Franz Schubert (1797-1828) Overture in C minor, D. 8 (1811) Louis Spohr (1784-1859) Seven string quintets Sir Charles Villiers Stanford (1852-1924) String Quintet no. 1 in F major, op. 85 (1903) String Quintet no. 2 in C minor, op. 86 (1903; unpublished) Johan Svendsen (1840-1911) String Quintet in C major, Op. 5 (1867) Sergey Taneyev (1856-1915) String Quintet no. 2 in C major, Op. 16 (1903-4) Ralph Vaughan Williams (1872-1958) Phantasy Quintet (1912)
"Cello" quintets:
String quintets with 2 violins, viola and 2 cellos David Baker (1931-2016) Two Cello String Quintet (1987) Violoncello and string quartet (Commissioned by Janos Starker) Ludwig van Beethoven Kreutzer Sonata arranged for String Quintet (Simrock, 1832) Luigi Boccherini (1743-1805) String Quintet Op. 10 No. 1 in A major, G 265 String Quintet Op. 10 No. 2 in E flat major, G 266 String Quintet Op. 10 No. 3 in C minor, G 267 String Quintet Op. 10 No. 4 in C major, G 268 String Quintet Op. 10 No. 5 in E flat major, G 269 String Quintet Op. 10 No. 6 in D major, G 270 String Quintet Op. 11 No. 1 in B flat major, G 271 String Quintet Op. 11 No. 2 in A major, G 272 String Quintet Op. 11 No. 3 in C major, G 273 String Quintet Op. 11 No. 4 in F minor, G 274 String Quintet Op. 11 No. 5 in E major, G 275 (This quintet includes the well-known "Boccherini's Minuet") String Quintet Op. 11 No. 6 in D major ("L'uccelliera" - "Bird Sanctuary"), G 276 String Quintet Op. 13 No. 1 in E flat major, G 277 String Quintet Op. 13 No. 2 in C major, G 278 String Quintet Op. 13 No. 3 in F major, G 279 String Quintet Op. 13 No. 4 in D minor, G 280 String Quintet Op. 13 No. 5 in A major, G 281 String Quintet Op. 13 No. 6 in E major, G 282 String Quintet Op. 18 No. 1 in C minor, G 283 String Quintet Op. 18 No. 2 in D major, G 284 String Quintet Op. 18 No. 3 in E flat major, G 285 String Quintet Op. 18 No. 4 in C major, G 286 String Quintet Op. 18 No. 5 in D minor, G 287 String Quintet Op. 18 No. 6 in E major, G 288 String Quintet Op. 20 No. 1 in E flat major, G 289 String Quintet Op. 20 No. 2 in B flat major, G 290 String Quintet Op. 20 No. 3 in F major, G 291 String Quintet Op. 20 No. 4 in G major, G 292 String Quintet Op. 20 No. 5 in D minor, G 293 String Quintet Op. 20 No. 6 in A minor, G 294 String Quintet Op. 25 No. 1 in D minor, G 295 String Quintet Op. 25 No. 2 in E flat major, G 296 String Quintet Op. 25 No. 3 in A major, G 297 String Quintet Op. 25 No. 4 in C major, G 298 String Quintet Op. 25 No. 5 in D major, G 299 String Quintet Op. 25 No. 6 in A minor, G 300 String Quintet Op. 27 No. 1 in A major, G 301 String Quintet Op. 27 No. 2 in G major, G 302 String Quintet Op. 27 No. 3 in E minor, G 303 String Quintet Op. 27 No. 4 in E flat major, G 304 String Quintet Op. 27 No. 5 in G minor, G 305 String Quintet Op. 27 No. 6 in B minor, G 306 String Quintet Op. 28 No. 1 in F major, G 307 String Quintet Op. 28 No. 2 in A major, G 308 String Quintet Op. 28 No. 3 in E flat major, G 309 String Quintet Op. 28 No. 4 in C major, G 310 String Quintet Op. 28 No. 5 in D minor, G 311 String Quintet Op. 28 No. 6 in B flat major, G 312 String Quintet Op. 29 No. 1 in D major, G 313 String Quintet Op. 29 No. 2 in C minor, G 314 String Quintet Op. 29 No. 3 in F major, G 315 String Quintet Op. 29 No. 4 in A major, G 316 String Quintet Op. 29 No. 5 in E flat major, G 317 String Quintet Op. 29 No. 6 in G minor, G 318 String Quintet Op. 30 No. 1 in B flat major, G 319 String Quintet Op. 30 No. 2 in A minor, G 320 String Quintet Op. 30 No. 3 in C major, G 321 String Quintet Op. 30 No. 4 in E flat major, G 322 String Quintet Op. 30 No. 5 in E minor, G 323 String Quintet Op. 30 No. 6 in C major ("Musica notturna delle strade di Madrid"), G 324 String Quintet Op. 31 No. 1 in E flat major, G 325 String Quintet Op. 31 No. 2 in G major, G 326 String Quintet Op. 31 No. 3 in B flat major, G 327 String Quintet Op. 31 No. 4 in C minor, G 328 String Quintet Op. 31 No. 5 in A major, G 329 String Quintet Op. 31 No. 6 in F major, G 330 String Quintet Op. 36 No. 1 in E flat major, G 331 String Quintet Op. 36 No. 2 in D major, G 332 String Quintet Op. 36 No. 3 in G major, G 333 String Quintet Op. 36 No. 4 in A minor, G 334 String Quintet Op. 36 No. 5 in G minor, G 335 String Quintet Op. 36 No. 6 in F major, G 336 String Quintet Op. 39 No. 1 in B flat major, G 337 String Quintet Op. 39 No. 2 in F major, G 338 String Quintet Op. 39 No. 3 in D major, G 339 String Quintet Op. 40 No. 1 in A major, G 340 String Quintet Op. 40 No. 2 in D major, G 341 String Quintet Op. 40 No. 3 in D major, G 342 String Quintet Op. 40 No. 4 in C major, G 343 String Quintet Op. 40 No. 5 in E minor, G 344 String Quintet Op. 40 No. 6 in B flat major, G 345 String Quintet Op. 41 No. 1 in E flat major, G 346 String Quintet Op. 41 No. 2 in F major, G 347 String Quintet Op. 42 No. 1 in F minor, G 348 String Quintet Op. 42 No. 2 in C major, G 349 String Quintet Op. 42 No. 3 in B minor, G 350 String Quintet Op. 42 No. 4 in G minor, G 351 String Quintet Op. 43 No. 1 in E flat major, G 352 String Quintet Op. 43 No. 2 in D major, G 353 String Quintet Op. 43 No. 3 in F major, G 354 String Quintet Op. 45 No. 1 in C minor, G 355 String Quintet Op. 45 No. 2 in A major, G 356 String Quintet Op. 45 No. 3 in B flat major, G 357 String Quintet Op. 45 No. 4 in C major, G 358 String Quintet Op. 46 No. 1 in B flat major, G 359 String Quintet Op. 46 No. 2 in D minor, G 360 String Quintet Op. 46 No. 3 in C major, G 361 String Quintet Op. 46 No. 4 in G minor, G 362 String Quintet Op. 46 No. 5 in F major, G 363 String Quintet Op. 46 No. 6 in E flat major, G 364 String Quintet Op. 49 No. 1 in D major, G 365 String Quintet Op. 49 No. 2 in B flat major, G 366 String Quintet Op. 49 No. 3 in E flat major, G 367 String Quintet Op. 49 No. 4 in D minor, G 368 String Quintet Op. 49 No. 5 in E flat major, G 369 String Quintet Op. 50 No. 1 in A major, G 370 String Quintet Op. 50 No. 2 in E flat major, G 371 String Quintet Op. 50 No. 3 in B flat major, G 372 String Quintet Op. 50 No. 4 in E major, G 373 String Quintet Op. 50 No. 5 in C major, G 374 String Quintet Op. 50 No. 6 in B flat major, G 375 String Quintet Op. 51 No. 1 in E flat major, G 376 String Quintet Op. 51 No. 2 in C minor, G 377 String Quintet in C major, G 378 String Quintet in E minor (from G 407), G 379 String Quintet in F major (from G 408), G 380 String Quintet in E flat major (from G 410), G 381 String Quintet in A minor (from G 412), G 382 String Quintet in D major (from G 411), G 383 String Quintet in C major (from G 409), G 384 String Quintet in D minor (from G 416), G 385 String Quintet in E minor (from G 417), G 386 String Quintet in B flat major (from G 414), G 387 String Quintet in A major (from G 413), G 388 String Quintet in E minor (from G 415), G 389 String Quintet in C major (from G 418), G 390 String Quintet Op. 60 No. 1 in C major, G 391 String Quintet Op. 60 No. 2 in B flat major, G 392 String Quintet Op. 60 No. 3 in A major, G 393 String Quintet Op. 60 No. 4 in E flat major (lost), G 394 String Quintet Op. 60 No. 5 in G major, G 395 String Quintet Op. 60 No. 6 in E major, G 396 String Quintet Op. 62 No. 1 in C major, G 397 String Quintet Op. 62 No. 2 in E flat major, G 398 String Quintet Op. 62 No. 3 in F major, G 399 String Quintet Op. 62 No. 4 in B flat major, G 400 String Quintet Op. 62 No. 5 in D major, G 401 String Quintet Op. 62 No. 6 in E major, G 402 String Quintet in E flat major (lost), G 406 Also: "String Quintet in C major" put together by Johann Lauterbach (1832-1918) from unrelated Boccherini string quintet movements Aleksandr Borodin (1833-87) String Quintet in F minor (1853-4: unfinished; completed by O. Evlakhov) Luigi Cherubini (1760-1842) String Quintet in E minor (1837) Carl Ditters von Dittersdorf (1739-99) Six string quintets Henry Eccles (1670-1742) Sonata in G minor for cello and strings (This is actually a sonata for viola da gamba and figured bass and not a string quintet. The version for cello and strings is a transcription. This sonata is also often played in a transcription for cello and piano.) Aleksandr Glazunov (1865-1936) String Quintet in A major, Op. 39 (1891-2) Karl Goldmark (1820-1915) String Quintet in A minor, Op. 9 (1862) Jay Greenberg (born 1991) String Quintet (2005) George Onslow (1784-1853) Twenty-two string quintets Three further string quintets with two versions, either for 2 violins, viola and 2 cellos or for 2 violins, 2 violas and cello Anton Reicha (1770-1836) Three string quintets Franz Schubert (1797-1828) Quintet in C major, D. 956, Op. 163 (1828) Peter Seabourne (born 1960) String Quintet Adrien-François Servais (1807-66) Souvenir de Spa for cello and strings Sergey Taneyev (1856-1915) String Quintet no. 1 in G major, Op. 14 (1900–01)
"Double bass" quintets:
String quintets with two violins, viola, cello and double bass Luigi Boccherini (1743-1805) String Quintet Op. 39 No. 1 in B flat major, G 337 (1787) String Quintet Op. 39 No. 2 in F major, G 338 (1787) String Quintet Op. 39 No. 3 in D major, G 339 (1787) Carl Ditters von Dittersdorf (1739-99) Six string quintets (with non-obbligato horns) Antonín Dvořák (1841-1904) String Quintet in G major, Op. 77 (1875) Alistair Hinton (born 1950) String Quintet (1969–77) George Onslow (1784-1853) Six string quintets
Sources:
Grove Music Online Jeffery, Paul 'A Player's Guide to Chamber Music' (Robert Hale, 2017) | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Low-g condition**
Low-g condition:
Low-g condition is a phase of aerodynamic flight where the airframe is temporarily unloaded. The pilot—and the airframe—feel temporarily "weightless" because the aircraft is in free-fall or decelerating vertically at the top of a climb. It may also occur during an excessively rapid entry into autorotation. This can have a disastrous effect on the aircraft, particularly in the case of helicopters, some of which need the rotor to constantly be under a non-zero amount of load.
Effects:
In smaller airplanes Most smaller airplanes and gliders have no problems with 0g conditions. In fact, it can be enjoyable to have zero gravity in the cockpit. To produce 0g, the aircraft has to follow a ballistic flight path, which is essentially an upside down parabola.
Effects:
This is the only method to simulate zero gravity for humans on earth. In helicopters In contrast, low-g conditions can be disastrous for helicopters. In such a situation their rotors may flap beyond normal limits. The excessive flapping can cause the root of the blades to exceed the limit of their hinges and this condition, known as mast bumping, can cause the separation of the blades from the hub or for the mast to shear, and hence detach the whole system from the aircraft, falling from the sky. This is especially true for helicopters with teetering rotors, such as the two-bladed design seen on Robinson helicopters.
Effects:
This effect was first discovered when many accidents with Bell UH-1 and AH-1 helicopters occurred. These particular helicopters simply crashed without any obvious cause. Later, it was found that these accidents usually happened during low terrain flight after passing a ridge and initiating a dive from the previous climb.
Articulated and rigid rotor systems do not lose controlling forces up to 0g, but may encounter this depending on their flapping hinge offset from the mast. However, dangerous situations, as with a teetering rotor, may not occur.
On fixed-wing aircraft Low-g conditions can also affect fixed-wing aircraft in some instances, mainly by disrupting the airflow over the wings, making them difficult or impossible to control via the aerodynamic surfaces.
The controllability of an airplane by the control surfaces only depends on airspeed. So, if one keeps airspeed, control is retained. Usually the controllability is even increased, because there is no need to produce lift. 0g forces are a minimal problem for fixed wing aircraft, but there are exceptions, including, but not limited to, airplanes with gravity-fed fuel systems.
Use in space agencies:
To simulate 0-g conditions some space agencies uses a modified passenger aircraft to simulate a low-g condition. The ESA uses an Airbus A300, for example. NASA has the Vomit Comet. One upside down parabola simulates 0g for about 25 s. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Legacy system**
Legacy system:
In computing, a legacy system is an old method, technology, computer system, or application program, "of, relating to, or being a previous or outdated computer system", yet still in use. Often referencing a system as "legacy" means that it paved the way for the standards that would follow it. This can also imply that the system is out of date or in need of replacement.
Legacy system:
Legacy code is old computer source code that is no longer supported on the standard hardware and environments, and is a codebase that is in some respect obsolete or supporting something obsolete. Legacy code may be written in programming languages, use frameworks and external libraries, or use architecture and patterns that are no longer considered modern, increasing the mental burden and ramp-up time for software engineers who work on the codebase. Legacy code may have zero or insufficient automated tests, making refactoring dangerous and likely to introduce bugs. Long-lived code is susceptible to software rot, where changes to the runtime environment, or surrounding software or hardware may require maintenance or emulation of some kind to keep working. Legacy code may be present to support legacy hardware, a separate legacy system, or a legacy customer using an old feature or software version.
Legacy system:
While the term usually refers to source code, it can also apply to executable code that no longer runs on a later version of a system, or requires a compatibility layer to do so. An example would be a classic Macintosh application which will not run natively on macOS, but runs inside the Classic environment, or a Win16 application running on Windows XP using the Windows on Windows feature in XP.
Legacy system:
An example of legacy hardware are legacy ports like PS/2 and VGA ports, and CPUs with older, incompatible instruction sets (with e.g. newer operating systems). Examples in legacy software include legacy file formats like .swf for Adobe Flash or .123 for Lotus 1-2-3, and text files encoded with legacy character encodings like EBCDIC.
Overview:
The first use of the term legacy to describe computer systems probably occurred in the 1960s. By the 1980s it was commonly used to refer to existing computer systems to distinguish them from the design and implementation of new systems. Legacy was often heard during a conversion process, for example, when moving data from the legacy system to a new database.
Overview:
While this term may indicate that some engineers may feel that a system is out of date, a legacy system can continue to be used for a variety of reasons. It may simply be that the system still provides for the users' needs. In addition, the decision to keep an old system may be influenced by economic reasons such as return on investment challenges or vendor lock-in, the inherent challenges of change management, or a variety of other reasons other than functionality. Backward compatibility (such as the ability of newer systems to handle legacy file formats and character encodings) is a goal that software developers often include in their work.
Overview:
Even if it is no longer used, a legacy system may continue to impact the organization due to its historical role. Historic data may not have been converted into the new system format and may exist within the new system with the use of a customized schema crosswalk, or may exist only in a data warehouse. In either case, the effect on business intelligence and operational reporting can be significant. A legacy system may include procedures or terminology which are no longer relevant in the current context, and may hinder or confuse understanding of the methods or technologies used.
Overview:
Organizations can have compelling reasons for keeping a legacy system, such as: The system works satisfactorily, and the owner sees no reason to change it.
The costs of redesigning or replacing the system are prohibitive because it is large, monolithic, and/or complex.
Retraining on a new system would be costly in lost time and money, compared to the anticipated appreciable benefits of replacing it (which may be zero).
Overview:
The system requires near-constant availability, so it cannot be taken out of service, and the cost of designing a new system with a similar availability level is high. Examples include systems to handle customers' accounts in banks, computer reservations systems, air traffic control, energy distribution (power grids), nuclear power plants, military defense installations, and systems such as the TOPS database.
Overview:
The way that the system works is not well understood. Such a situation can occur when the designers of the system have left the organization, and the system has either not been fully documented or documentation has been lost.
The user expects that the system can easily be replaced when this becomes necessary.
Overview:
Newer systems perform undesirable (especially for individual or non-institutional users) secondary functions such as a) tracking and reporting of user activity and/or b) automatic updating that creates "back-door" security vulnerabilities and leaves end users dependent on the good faith and honesty of the vendor providing the updates. This problem is especially acute when these secondary functions of a newer system cannot be disabled.
Problems posed by legacy computing:
Legacy systems are considered to be potentially problematic by some software engineers for several reasons.
If legacy software runs on only antiquated hardware, the cost of maintaining the system may eventually outweigh the cost of replacing both the software and hardware unless some form of emulation or backward compatibility allows the software to run on new hardware.
Problems posed by legacy computing:
These systems can be hard to maintain, improve, and expand because there is a general lack of understanding of the system; the staff who were experts on it have retired or forgotten what they knew about it, and staff who entered the field after it became "legacy" never learned about it in the first place. This can be worsened by lack or loss of documentation. Comair airline company fired its CEO in 2004 due to the failure of an antiquated legacy crew scheduling system that ran into a limitation not known to anyone in the company.
Problems posed by legacy computing:
Legacy systems may have vulnerabilities in older operating systems or applications due to lack of security patches being available or applied. There can also be production configurations that cause security problems. These issues can put the legacy system at risk of being compromised by attackers or knowledgeable insiders.
Problems posed by legacy computing:
Integration with newer systems may also be difficult because new software may use completely different technologies. Integration across technology is quite common in computing, but integration between newer technologies and substantially older ones is not common. There may simply not be sufficient demand for integration technology to be developed. Some of this "glue" code is occasionally developed by vendors and enthusiasts of particular legacy technologies.
Problems posed by legacy computing:
Budgetary constraints often lead corporations to not address the need of replacement or migration of a legacy system. However, companies often don't consider the increasing supportability costs (people, software and hardware, all mentioned above) and do not take into consideration the enormous loss of capability or business continuity if the legacy system were to fail. Once these considerations are well understood, then based on the proven ROI of a new, more secure, updated technology stack platform is not as costly as the alternative—and the budget is found.
Problems posed by legacy computing:
Due to the fact that most legacy programmers are entering retirement age and the number of young engineers replacing them is very small, there is an alarming shortage of available workforce. This in turn results in difficulty in maintaining legacy systems, as well as an increase in costs of procuring experienced programmers.
Some legacy systems have a hard limit on their total capacity which may not be enough for today's needs, for example the 4 GB memory limit on many older x86 CPUs, or the 4 billion address limit in IPv4.
Improvements on legacy software systems:
Where it is impossible to replace legacy systems through the practice of application retirement, it is still possible to enhance (or "re-face") them. Most development often goes into adding new interfaces to a legacy system. The most prominent technique is to provide a Web-based interface to a terminal-based mainframe application. This may reduce staff productivity due to slower response times and slower mouse-based operator actions, yet it is often seen as an "upgrade", because the interface style is familiar to unskilled users and is easy for them to use. John McCormick discusses such strategies that involve middleware.Printing improvements are problematic because legacy software systems often add no formatting instructions, or they use protocols that are not usable in modern PC/Windows printers. A print server can be used to intercept the data and translate it to a more modern code. Rich Text Format (RTF) or PostScript documents may be created in the legacy application and then interpreted at a PC before being printed.
Improvements on legacy software systems:
Biometric security measures are difficult to implement on legacy systems. A workable solution is to use a Telnet or HTTP proxy server to sit between users and the mainframe to implement secure access to the legacy application.
Improvements on legacy software systems:
The change being undertaken in some organizations is to switch to automated business process (ABP) software which generates complete systems. These systems can then interface to the organizations' legacy systems and use them as data repositories. This approach can provide a number of significant benefits: the users are insulated from the inefficiencies of their legacy systems, and the changes can be incorporated quickly and easily in the ABP software.
Improvements on legacy software systems:
Model-driven reverse and forward engineering approaches can be also used for the improvement of legacy software.
NASA example:
Andreas M. Hein, from the Technical University of Munich, researched the use of legacy systems in space exploration. According to Hein, legacy systems are attractive for reuse if an organization has the capabilities for verification, validation, testing, and operational history. These capabilities must be integrated into various software life cycle phases such as development, implementation, usage, or maintenance. For software systems, the capability to use and maintain the system are crucial. Otherwise the system will become less and less understandable and maintainable.
NASA example:
According to Hein, verification, validation, testing, and operational history increases the confidence in a system's reliability and quality. However, accumulating this history is often expensive. NASA's now retired Space Shuttle program used a large amount of 1970s-era technology. Replacement was cost-prohibitive because of the expensive requirement for flight certification. The original hardware completed the expensive integration and certification requirement for flight, but any new equipment would have had to go through that entire process again. This long and detailed process required extensive tests of the new components in their new configurations before a single unit could be used in the Space Shuttle program. Thus any new system that started the certification process becomes a de facto legacy system by the time it is approved for flight.
NASA example:
Additionally, the entire Space Shuttle system, including ground and launch vehicle assets, was designed to work together as a closed system. Since the specifications did not change, all of the certified systems and components performed well in the roles for which they were designed. Even before the Shuttle was scheduled to be retired in 2010, NASA found it advantageous to keep using many pieces of 1970s technology rather than to upgrade those systems and recertify the new components.
Perspectives on legacy code:
Some in the software engineering prefer to describe "legacy code" without the connotation of being obsolete. Among the most prevalent neutral conceptions are source code inherited from someone else and source code inherited from an older version of the software. Eli Lopian, CEO of Typemock, has defined it as "code that developers are afraid to change". Michael Feathers introduced a definition of legacy code as code without tests, which reflects the perspective of legacy code being difficult to work with in part due to a lack of automated regression tests. He also defined characterization tests to start putting legacy code under test.
Perspectives on legacy code:
Ginny Hendry characterized creation of code as a `challenge` to current coders to create code that is "like other legacies in our lives—like the antiques, heirlooms, and stories that are cherished and lovingly passed down from one generation to the next. What if legacy code was something we took pride in?".
Additional uses of the term Legacy in computing:
The term legacy support is often used in conjunction with legacy systems. The term may refer to a feature of modern software. For example, Operating systems with "legacy support" can detect and use older hardware. The term may also be used to refer to a business function; e.g. a software or hardware vendor that is supporting, or providing software maintenance, for older products.
Additional uses of the term Legacy in computing:
A "legacy" product may be a product that is no longer sold, has lost substantial market share, or is a version of a product that is not current. A legacy product may have some advantage over a modern product making it appealing for customers to keep it around. A product is only truly "obsolete" if it has an advantage to nobody—if no person making a rational decision would choose to acquire it new.
Additional uses of the term Legacy in computing:
The term "legacy mode" often refers specifically to backward compatibility. A software product that is capable of performing as though it were a previous version of itself, is said to be "running in legacy mode". This kind of feature is common in operating systems and internet browsers, where many applications depend on these underlying components.
The computer mainframe era saw many applications running in legacy mode. In the modern business computing environment, n-tier, or 3-tier architectures are more difficult to place into legacy mode as they include many components making up a single system.
Virtualization technology is a recent innovation allowing legacy systems to continue to operate on modern hardware by running older operating systems and browsers on a software system that emulates legacy hardware.
Brownfield architecture:
Programmers have borrowed the term brownfield from the construction industry, where previously developed land (often polluted and abandoned) is described as brownfield.
Brownfield architecture is a type of software or network architecture that incorporates legacy systems.
Brownfield deployment is an upgrade or addition to an existing software or network architecture that retains legacy components.
Alternative view:
There is an alternate favorable opinion—growing since the end of the Dotcom bubble in 1999—that legacy systems are simply computer systems in working use: "Legacy code" often differs from its suggested alternative by actually working and scaling.
IT analysts estimate that the cost of replacing business logic is about five times that of reuse, even discounting the risk of system failures and security breaches. Ideally, businesses would never have to rewrite most core business logic: debits = credits is a perennial requirement.
Alternative view:
The IT industry is responding with "legacy modernization" and "legacy transformation": refurbishing existing business logic with new user interfaces, sometimes using screen scraping and service-enabled access through web services. These techniques allow organizations to understand their existing code assets (using discovery tools), provide new user and application interfaces to existing code, improve workflow, contain costs, minimize risk, and enjoy classic qualities of service (near 100% uptime, security, scalability, etc.).This trend also invites reflection on what makes legacy systems so durable. Technologists are relearning the importance of sound architecture from the start, to avoid costly and risky rewrites. The most common legacy systems tend to be those which embraced well-known IT architectural principles, with careful planning and strict methodology during implementation. Poorly designed systems often don't last, both because they wear out and because their inherent faults invite replacement. Thus, many organizations are rediscovering the value of both their legacy systems and the theoretical underpinnings of those systems. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Citric acid/potassium-sodium citrate**
Citric acid/potassium-sodium citrate:
Citric acid/potassium-sodium citrate is a drug used in the treatment of metabolic acidosis (a disorder in which the blood is too acidic). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Salpicon**
Salpicon:
Salpicon (or salpicón, meaning "hodgepodge" or "medley" in Spanish) is a dish of one or more ingredients diced or minced and bound with a sauce or liquid. There are different versions found in Spanish and the broader Latin American cuisine. A salpicon is sometimes used as stuffing.
In Mexican cuisine and Central American cuisine, the term refers to a salad mixture containing thinly sliced or chopped flank steak, onion, oregano, chile serrano, avocado, tomatoes, and vinegar. The mixture is commonly served on tostadas, tacos or as a filling of poblano peppers. In Honduras, rabbit meat is used.
In Colombian cuisine, salpicón is a fruit cocktail beverage made with a base of watermelon and/or orange juice, which gives it its bright red color, and soda water. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Phred quality score**
Phred quality score:
A Phred quality score is a measure of the quality of the identification of the nucleobases generated by automated DNA sequencing. It was originally developed for the computer program Phred to help in the automation of DNA sequencing in the Human Genome Project. Phred quality scores are assigned to each nucleotide base call in automated sequencer traces. The FASTQ format encodes phred scores as ASCII characters alongside the read sequences. Phred quality scores have become widely accepted to characterize the quality of DNA sequences, and can be used to compare the efficacy of different sequencing methods. Perhaps the most important use of Phred quality scores is the automatic determination of accurate, quality-based consensus sequences.
Definition:
Phred quality scores Q are logarithmically related to the base-calling error probabilities P and defined as 10 log 10 P This relation can be also be written as 10 10 For example, if Phred assigns a quality score of 30 to a base, the chances that this base is called incorrectly are 1 in 1000.
The phred quality score is the negative ratio of the error probability to the reference level of P=1 expressed in Decibel (dB).
History:
The idea of sequence quality scores can be traced back to the original description of the SCF file format by Staden's group in 1992. In 1995, Bonfield and Staden proposed a method to use base-specific quality scores to improve the accuracy of consensus sequences in DNA sequencing projects.However, early attempts to develop base-specific quality scores had only limited success.
History:
The first program to develop accurate and powerful base-specific quality scores was the program Phred. Phred was able to calculate highly accurate quality scores that were logarithmically linked to the error probabilities. Phred was quickly adopted by all the major genome sequencing centers as well as many other laboratories; the vast majority of the DNA sequences produced during the Human Genome Project were processed with Phred.
History:
After Phred quality scores became the required standard in DNA sequencing, other manufacturers of DNA sequencing instruments, including Li-Cor and ABI, developed similar quality scoring metrics for their base calling software.
Methods:
Phred's approach to base calling and calculating quality scores was outlined by Ewing et al.. To determine quality scores, Phred first calculates several parameters related to peak shape and peak resolution at each base. Phred then uses these parameters to look up a corresponding quality score in huge lookup tables. These lookup tables were generated from sequence traces where the correct sequence was known, and are hard coded in Phred; different lookup tables are used for different sequencing chemistries and machines. An evaluation of the accuracy of Phred quality scores for a number of variations in sequencing chemistry and instrumentation showed that Phred quality scores are highly accurate.Phred was originally developed for "slab gel" sequencing machines like the ABI373. When originally developed, Phred had a lower base calling error rate than the manufacturer's base calling software, which also did not provide quality scores. However, Phred was only partially adapted to the capillary DNA sequencers that became popular later. In contrast, instrument manufacturers like ABI continued to adapt their base calling software changes in sequencing chemistry, and have included the ability to create Phred-like quality scores. Therefore, the need to use Phred for base calling of DNA sequencing traces has diminished, and using the manufacturer's current software versions can often give more accurate results.
Applications:
Phred quality scores are used for assessment of sequence quality, recognition and removal of low-quality sequence (end clipping), and determination of accurate consensus sequences.
Applications:
Originally, Phred quality scores were primarily used by the sequence assembly program Phrap. Phrap was routinely used in some of the largest sequencing projects in the Human Genome Sequencing Project and is currently one of the most widely used DNA sequence assembly programs in the biotech industry. Phrap uses Phred quality scores to determine highly accurate consensus sequences and to estimate the quality of the consensus sequences. Phrap also uses Phred quality scores to estimate whether discrepancies between two overlapping sequences are more likely to arise from random errors, or from different copies of a repeated sequence.
Applications:
Within the Human Genome Project, the most important use of Phred quality scores was for automatic determination of consensus sequences. Before Phred and Phrap, scientists had to carefully look at discrepancies between overlapping DNA fragments; often, this involved manual determination of the highest-quality sequence, and manual editing of any errors. Phrap's use of Phred quality scores effectively automated finding the highest-quality consensus sequence; in most cases, this completely circumvents the need for any manual editing. As a result, the estimated error rate in assemblies that were created automatically with Phred and Phrap is typically substantially lower than the error rate of manually edited sequence.
Applications:
In 2009, many commonly used software packages make use of Phred quality scores, albeit to a different extent. Programs like Sequencher use quality scores for display, end clipping, and consensus determination; other programs like CodonCode Aligner also implement quality-based consensus methods.
Compression:
Quality scores are normally stored together with the nucleotide sequence in the widely accepted FASTQ format. They account for about half of the required disk space in the FASTQ format (before compression), and therefore the compression of the quality values can significantly reduce storage requirements and speed up analysis and transmission of sequencing data. Both lossless and lossy compression are recently being considered in the literature. For example, the algorithm QualComp performs lossy compression with a rate (number of bits per quality value) specified by the user. Based on rate-distortion theory results, it allocates the number of bits so as to minimize the MSE (mean squared error) between the original (uncompressed) and the reconstructed (after compression) quality values. Other algorithms for compression of quality values include SCALCE, Fastqz and more recently QVZ, AQUa and the MPEG-G standard, that is currently under development by the MPEG standardisation working group. Both are lossless compression algorithms that provide an optional controlled lossy transformation approach. For example, SCALCE reduces the alphabet size based on the observation that “neighboring” quality values are similar in general. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Macrophomic acid**
Macrophomic acid:
Macrophomic acid is a fungal metabolite isolated from the fungus Macrophoma commelinae. The enzyme macrophomate synthase converts 5-acetyl-4-methoxy-6-methyl-2-pyrone to 4-acetyl-3-methoxy-5-methyl-benzoic acid (macrophomic acid) through an unusual intermolecular Diels-Alder reaction (Scheme 1). The pathway to formation of macrophomic acid suggests that the enzyme is a natural Diels-Alderase. Formation of this type of aromatic ring compound normally proceeds via the shikimate and polyketide pathways; however, the production of macrophomic acid by macrophomate synthase proceeds totally differently. Learning about the production of macrophomic acid by a possible natural Diels-Alderase enzyme is important in understanding enzyme catalytic mechanisms. This knowledge can then be applied to organic synthesis.
Biosynthesis:
The biosynthesis of macrophomic acid is catalyzed by the enzyme macrophomate synthase. The unusual multistep conversion of 5-acetyl-4-methoxy-6-methyl-2-pyrone (3) to macrophomic acid is thought to proceed by either a concerted Diels-Alder reaction or a recently proposed 2-step Michael-aldol sequence. The Michael-aldol sequence involves a Michael addition reaction and an aldol condensation. The actual pathway is not yet understood completely. In the conversion of the 2-pyrone (3), oxaloacetate (1) is decarboxylated to form an enolate that coordinates to a Mg2+ metal center (2) found in the active site of the enzyme. Then, the coordinated enolate can either add to the 2-pyrone (3) through a Michael-aldol or Diels-Alder pathway. Both pathways include a bicyclic intermediate (4).
Biosynthesis:
In the Michael-aldol pathway (Scheme 2), The coordinated oxaloacetate enolate performs a Michael addition to the ring of the pyrone to form intermediate 4. Next, this intermediate undergoes an aldol condensation to form the proposed bicyclic intermediate (5). Finally, this bicyclic compound undergoes a decarboxylation to form intermediate 6 and dehydration to form macrophomic acid (7).
Biosynthesis:
In the Diels-Alder mechanism for the biosynthesis of macrophomic acid (Scheme 3), oxaloacetate is decarboxylated to form the enolate complex with Mg2+. Next, the enolate complex adds to the pyrone through a Diels-Alder concerted reaction to form a bicyclic intermediate (8). Then, just as in the Michael-aldol sequence, the bicyclic intermediate gets decarboxylated and dehydrated to form macrophomic acid (9). This pathway is thought to be the actual mechanism; however, according to QM/MM calculations, it seems that the Michael-aldol sequence is more energetically favored. There has also been difficulty in isolating the key intermediates for either proposed pathway. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Fricative**
Fricative:
A fricative is a consonant produced by forcing air through a narrow channel made by placing two articulators close together. These may be the lower lip against the upper teeth, in the case of [f]; the back of the tongue against the soft palate in the case of German [x] (the final consonant of Bach); or the side of the tongue against the molars, in the case of Welsh [ɬ] (appearing twice in the name Llanelli). This turbulent airflow is called frication.A particular subset of fricatives are the sibilants. When forming a sibilant, one still is forcing air through a narrow channel, but in addition, the tongue is curled lengthwise to direct the air over the edge of the teeth. English [s], [z], [ʃ], and [ʒ] are examples of sibilants.
Fricative:
The usage of two other terms is less standardized: "Spirant" is an older term for fricatives used by some American and European phoneticians and phonologists. "Strident" could mean just "sibilant", but some authors include also labiodental and uvular fricatives in the class.
Types:
The airflow is not completely stopped in the production of fricative consonants. In other words, the airflow experiences friction.
Types:
Sibilants [s] voiceless coronal sibilant, as in English sip [z] voiced coronal sibilant, as in English zip [s̪] voiceless dental sibilant [z̪] voiced dental sibilant [s̺] voiceless apical sibilant [z̺] voiced apical sibilant [s̟] voiceless predorsal sibilant (laminal, with tongue tip at lower teeth) [z̟] voiced predorsal sibilant (laminal) [s̠] voiceless postalveolar sibilant (laminal) [z̠] voiced postalveolar sibilant (laminal) [ʃ] voiceless palato-alveolar sibilant (domed, partially palatalized), as in English ship [ʒ] voiced palato-alveolar sibilant (domed, partially palatalized), as the si in English vision [ɕ] voiceless alveolo-palatal sibilant (laminal, palatalized) [ʑ] voiced alveolo-palatal sibilant (laminal, palatalized) [ʂ] voiceless retroflex sibilant (apical or subapical) [ʐ] voiced retroflex sibilant (apical or subapical)All sibilants are coronal, but may be dental, alveolar, postalveolar, or palatal (retroflex) within that range. However, at the postalveolar place of articulation, the tongue may take several shapes: domed, laminal, or apical, and each of these is given a separate symbol and a separate name. Prototypical retroflexes are subapical and palatal, but they are usually written with the same symbol as the apical postalveolars. The alveolars and dentals may also be either apical or laminal, but this difference is indicated with diacritics rather than with separate symbols.
Types:
Central non-sibilant fricatives [ɸ] voiceless bilabial fricative [β] voiced bilabial fricative [f] voiceless labiodental fricative, as in English fine [v] voiced labiodental fricative, as in English vine [θ̼] voiceless linguolabial fricative [ð̼] voiced linguolabial fricative [θ], [θ̟] voiceless dental non-sibilant fricative, as in English thing [ð], [ð̟] voiced dental non-sibilant fricative, as in English that [θ̠], [ɹ̝̊] voiceless alveolar non-sibilant fricative [ð̠], [ɹ̝] voiced alveolar non-sibilant fricative [r̝̊] voiceless trilled fricative [r̝] voiced trilled fricative [ç] voiceless palatal fricative [ʝ] voiced palatal fricative [x] voiceless velar fricative [ɣ] voiced velar fricative [ɧ] voiceless palatal-velar fricative (articulation disputed)The IPA also has letters for epiglottal fricatives, [ʜ] voiceless epiglottal fricative [ʢ] voiced epiglottal fricativewith allophonic trilling, but these might be better analyzed as pharyngeal trills.
Types:
[ʩ] voiceless velopharyngeal fricative (often occurs with a cleft palate) [ʩ̬] voiced velopharyngeal fricative Lateral fricatives [ɬ̪] voiceless dental lateral fricative [ɮ̪] voiced dental lateral fricative [ɬ] voiceless alveolar lateral fricative [ɮ] voiced alveolar lateral fricative [ɬ̠] voiceless postalveolar lateral fricative (Mehri) [ɮ̠] voiced postalveolar lateral fricative [ɭ˔̥] or extIPA [ꞎ] voiceless retroflex lateral fricative [ɭ˔] or extIPA [𝼅] Voiced retroflex lateral fricative (in Ao) [ʎ̥˔] or [ʎ̝̥] or extIPA [𝼆] voiceless palatal lateral fricative [ʎ̝] or extIPA [𝼆̬] voiced palatal lateral fricative (allophonic in Jebero) [ʟ̝̊] or extIPA [𝼄] voiceless velar lateral fricative [ʟ̝] or extIPA [𝼄̬] voiced velar lateral fricativeThe lateral fricative occurs as the ll of Welsh, as in Lloyd, Llewelyn, and Machynlleth ([maˈxənɬɛθ], a town), as the unvoiced 'hl' and voiced 'dl' or 'dhl' in the several languages of Southern Africa (such as Xhosa and Zulu), and in Mongolian.
Types:
ʪ or [ɬ͜s] and [θ͜ɬ] voiceless grooved lateral alveolar fricative (a laterally lisped [s] or [θ]) (Modern South Arabian) ʫ or [ɮ͜z] and [ð͜ɮ] voiced grooved lateral alveolar fricative (a laterally lisped [z] or [ð]) (Modern South Arabian) IPA letters used for both fricatives and approximants [χ] voiceless uvular fricative [ʁ] voiced uvular fricative [ħ] voiceless pharyngeal fricative [ʕ] voiced pharyngeal fricativeNo language distinguishes fricatives from approximants at these places, so the same symbol is used for both. For the pharyngeal, approximants are more numerous than fricatives. A fricative realization may be specified by adding the uptack to the letters, [χ̝, ʁ̝, ħ̝, ʕ̝]. Likewise, the downtack may be added to specify an approximant realization, [χ̞, ʁ̞, ħ̞, ʕ̞].
Types:
(The bilabial approximant and dental approximant do not have dedicated symbols either and are transcribed in a similar fashion: [β̞, ð̞]. However, the base letters are understood to specifically refer to the fricatives.) Pseudo-fricatives [h] voiceless glottal transition, as in English hat [ɦ] breathy-voiced glottal transitionIn many languages, such as English, the glottal "fricatives" are unaccompanied phonation states of the glottis, without any accompanying manner, fricative or otherwise. However, in languages such as Arabic, they are true fricatives.In addition, [ʍ] is usually called a "voiceless labial-velar fricative", but it is actually an approximant. True doubly articulated fricatives may not occur in any language; but see voiceless palatal-velar fricative for a putative (and rather controversial) example.
Types:
Aspirated fricatives Fricatives are very commonly voiced, though cross-linguistically voiced fricatives are not nearly as common as tenuis ("plain") fricatives. Other phonations are common in languages that have those phonations in their stop consonants. However, phonemically aspirated fricatives are rare. /s~sʰ/ contrasts with a tense, unaspirated /s͈/ in Korean; aspirated fricatives are also found in a few Sino-Tibetan languages, in some Oto-Manguean languages, in the Siouan language Ofo (/sʰ/ and /fʰ/), and in the (central?) Chumash languages (/sʰ/ and /ʃʰ/). The record may be Cone Tibetan, which has four contrastive aspirated fricatives: /sʰ/ /ɕʰ/, /ʂʰ/, and /xʰ/.
Types:
Nasalized fricatives Phonemically nasalized fricatives are rare. Umbundu has /ṽ/ and Kwangali and Souletin Basque have /h̃/. In Coatzospan Mixtec, [β̃, ð̃, s̃, ʃ̃] appear allophonically before a nasal vowel, and in Igbo nasality is a feature of the syllable; when /f v s z ʃ ʒ/ occur in nasal syllables they are themselves nasalized.
Occurrence:
Until its extinction, Ubykh may have been the language with the most fricatives (29 not including /h/), some of which did not have dedicated symbols or diacritics in the IPA. This number actually outstrips the number of all consonants in English (which has 24 consonants). By contrast, approximately 8.7% of the world's languages have no phonemic fricatives at all. This is a typical feature of Australian Aboriginal languages, where the few fricatives that exist result from changes to plosives or approximants, but also occurs in some indigenous languages of New Guinea and South America that have especially small numbers of consonants. However, whereas [h] is entirely unknown in indigenous Australian languages, most of the other languages without true fricatives do have [h] in their consonant inventory.
Occurrence:
Voicing contrasts in fricatives are largely confined to Europe, Africa, and Western Asia. Languages of South and East Asia, such as Mandarin Chinese, Korean, and the Austronesian languages, typically do not have such voiced fricatives as [z] and [v], which are familiar to many European speakers. In some Dravidian languages they occur as allophones. These voiced fricatives are also relatively rare in indigenous languages of the Americas. Overall, voicing contrasts in fricatives are much rarer than in plosives, being found only in about a third of the world's languages as compared to 60 percent for plosive voicing contrasts.About 15 percent of the world's languages, however, have unpaired voiced fricatives, i.e. a voiced fricative without a voiceless counterpart. Two-thirds of these, or 10 percent of all languages, have unpaired voiced fricatives but no voicing contrast between any fricative pair.This phenomenon occurs because voiced fricatives have developed from lenition of plosives or fortition of approximants. This phenomenon of unpaired voiced fricatives is scattered throughout the world, but is confined to nonsibilant fricatives with the exception of a couple of languages that have [ʒ] but lack [ʃ]. (Relatedly, several languages have the voiced affricate [dʒ] but lack [tʃ], and vice versa.) The fricatives that occur most often without a voiceless counterpart are – in order of ratio of unpaired occurrences to total occurrences – [ʝ], [β], [ð], [ʁ] and [ɣ].
Acoustics:
Fricatives appear in waveforms as somewhat random noise caused by the turbulent airflow, upon which a periodic pattern is overlaid if voiced. Fricatives produced in the front of the mouth tend to have energy concentration at higher frequencies than ones produced in the back. The centre of gravity (CoG), i.e. the average frequency in a spectrum weighted by the amplitude (also known as spectral mean), may be used to determine the place of articulation of a fricative relative to that of another. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**SARS conspiracy theory**
SARS conspiracy theory:
The SARS conspiracy theory began to emerge during the severe acute respiratory syndrome (SARS) outbreak in China in the spring of 2003, when Sergei Kolesnikov, a Russian scientist and a member of the Russian Academy of Medical Sciences, first publicized his claim that the SARS coronavirus is a synthesis of measles and mumps. According to Kolesnikov, this combination cannot be formed in the natural world and thus the SARS virus must have been produced under laboratory conditions. Another Russian scientist, Nikolai Filatov, head of Moscow's epidemiological services, had earlier commented that the SARS virus was probably man-made.However, independent labs concluded these claims to be premature since the SARS virus is a coronavirus, whereas measles and mumps are paramyxoviruses. The primary differences between a coronavirus and a paramyxovirus are in their structures and method of infection, thus making it implausible for a coronavirus to have been created from two paramyxoviruses.
SARS conspiracy theory:
The widespread reporting of claims by Kolesnokov and Filatov caused controversy in many Chinese internet discussion boards and chat rooms. Many Chinese believed that the SARS virus could be a biological weapon manufactured by the United States, which perceived China as a potential threat.
SARS conspiracy theory:
The failure to find the source of the SARS virus further convinced these people and many more that SARS was artificially synthesised and spread by some individuals and even governments. Circumstantial evidence suggests that the SARS virus crossed over to humans from Asian palm civets ("civet cats"), a type of animal that is often killed and eaten in Guangdong, where SARS was first discovered.Supporters of the conspiracy theory suggest that SARS caused the most serious harm in mainland China, Hong Kong, Taiwan and Singapore, regions where most Chinese reside, while the United States, Europe and Japan were not affected as much. However, the highest mortality from SARS outside of China occurred in Canada where 43 died. Conspiracists further take as evidence the idea that, although SARS has an average mortality rate of around 10% around the world, no one died in the United States from SARS. However, there were only 8 confirmed cases out of 27 probable cases in the US (10% of 8 people is less than 1 person). Regarding reasons why SARS patients in the United States experienced a relatively mild illness, the U.S. Centers for Disease Control has explained that anybody with fever and a respiratory symptom who had traveled to an affected area was included as a SARS patient in the U.S., even though many of these were found to have had other respiratory illnesses.Tong Zeng, an activist with no medical background, authored the book The Last Defense Line: Concerns About the Loss of Chinese Genes, published in 2003. In the book, Zeng suggested researchers from the United States may have created SARS as an anti-Chinese bioweapon after taking blood samples in China for a longevity study in the 1990s. The book's hypothesis was a front-page report in the Guangzhou newspaper Southern Metropolis Daily.Coronaviruses similar to SARS have been found in bats in China, suggesting they may be their natural reservoir. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Solithromycin**
Solithromycin:
Solithromycin (trade name Solithera) is a ketolide antibiotic undergoing clinical development for the treatment of community-acquired pneumonia and other infections.Solithromycin exhibits excellent in vitro activity against a broad spectrum of Gram-positive respiratory tract pathogens, including macrolide-resistant strains. Solithromycin has activity against most common respiratory Gram-positive and fastidious Gram-negative pathogens, and is being evaluated for its utility in treating gonorrhea.
Pre-clinical studies:
An in vivo pre-clinical study performed by Jeffrey Keelan done in sheep may provide a prophylactic approach for intrauterine infections during pregnancy. This study was carried out by administering solithromycin to pregnant sheep, resulting in effective concentrations greater than 30 ng/ml in the fetal plasma, maternal plasma and amniotic fluid. A single maternal dose maintained these concentrations for over 12 hours.
Clinical trials:
May 2011: solithromycin is in a Phase 2 clinical trial for serious community-acquired bacterial pneumonia and in a Phase 1 clinical trial with an intravenous formulation.
September 2011: solithromycin demonstrated comparable efficacy to levofloxacin with reduced adverse events in Phase 2 trial in people with community-acquired pneumonia January 2015: in a Phase 3 clinical trial for community-acquired bacterial pneumonia, solithromycin administered orally demonstrated statistical non-inferiority to the fluoroquinolone moxifloxacin.
July 2015: patient enrollment for the second Phase 3 clinical trial (Solitaire IV) for community-acquired bacterial pneumonia was completed with results expected in Q4 2015.
Oct 2015: IV to oral solithromycin demonstrated statistical non-inferiority to IV to oral moxifloxacin in adults with community-acquired bacterial pneumonia.
July 2016: Cempra announced FDA acceptance of IV and oral formulations of Solithera (solithromycin) new drug applications for the treatment of community-acquired bacterial pneumonia.
Structure:
X-ray crystallography studies have shown solithromycin, the first fluoroketolide in clinical development, has a third region of interactions with the bacterial ribosome, as compared with two binding sites for other ketolides.
Structure:
The only previously marketed ketolide, telithromycin, suffers from rare but serious side effects. Recent studies have shown this to be likely due to the presence of the pyridine-imidazole group of the telithromycin side chain acting as an antagonist towards various nicotinic acetylcholine receptors. Solithromycin differs from telithromycin because the side chain does not significantly antagonize nicotinic acetylcholine receptors. Instead of the pyridine-imidazole group used on telithromycin, this molecule has a triazole-phenylamine moiety.
Mechanism of action:
Solithromycin inhibits bacterial translation by binding to the 23S ribosomal RNA, preventing the offending bacteria from synthesizing proteins.
Side effects:
During a clinical study some patients presented with elevated liver enzyme which may or may not be indicative of hepatotoxicity. This prompted the FDA Antimicrobial Drugs Advisory Committee to vote that the risk to the liver has not been adequately characterized and that further studies need to be conducted. To this extent, the FDA requests a 9,000 patient safety trial as well as restricting the drug.
Development:
In 2008, investigational new drug applications for solithromycin capsules and an intravenous formulation were submitted. From studies of pharmacokinetics, safety, and efficacy several issues were found. There is variable absorption which can result in subtherapeutic drug concentrations and even therapy failure. Additionally, there are significant drug-drug interactions affecting solithromycin concentrations as well the concentrations of the offending drugs. There is also a narrow therapeutic margin which can make this drug challenging to dose.
Commercial aspects:
Cempra's general plan is to develop solithromycin develop products through late stage clinical trials and sell them to their hospital based sales force or through partnerships, which would need negotiations with larger pharmaceutical companies. There are several manufacturing plants used such as Wockhardt Limited and Hospira Incorporated manufacturing facilities as well as Uquifa Laboratories, an alternative GMP facility.
Intellectual property:
Due to the fact that bringing new products to the market takes a significant investment of time and money, companies place considerable importance on patent protection for new products. Solithromycin is a new chemical entity from the macrolide library of compounds that were licensed by Optimer. It is covered by a series of patents and patent applications which claim the composition of matter of solithromycin. There are also patents surrounding the synthesis and purification of this substance. For example, patent EP3190122 A1 presents a novel, efficient route of synthesis that bypasses the need for chromatographic purification which saves time. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Role Class Model**
Role Class Model:
In computer science, the role class model is a role analysis pattern described (but not invented ) by Francis G. Mossé in his article on Modelling Roles. The role class pattern provides the ability for a class to play multiple roles and to embed the role characteristic in a dedicated class.
In our society, as we built it, roles are everywhere. Anyone trying to work in a team to create something has a role. In cinematography, many different persons take part in the creation of a film: the film director, the producer, actors, play writer(s), etc.
Even our State organisations are based on various roles. In a Republic, you have a President, Ministers, Deputies, etc.
Role Class Model:
Dealing with these situations is one of the problems encountered most during object-oriented analysis. Francis G. Mossé has identified 5 role analysis patterns that can be used to solve most role related problems: Role Inheritance, Association Roles, Role Classes, Generalised Role Classes and Association Class Roles. They all have various degrees of constraints, flexibility or power, which together offer a complete solution to most role-related problems.
Intent:
A model that allows a class to play one or more roles at the same time. A role - as defined by Francis Mossé in Modelling Roles - is a concept of a purpose that a class could have in a certain context.
Context:
The following example is given: Many persons work on a film, each of them with a different role. At the difference of other concepts, a person is not restricted to one role. One could be both the director and a character in a film. Modelling roles for such a concept would require that a class could play more than a single role.
Context:
A solution using inheritance to conceptualise a role - cf. the Inheritance Role Model - is not possible, as this would allow a person to play only a single role. As one can see in Figure 1 below, the inheritance role model says that a character, who is a person, is playing in a film. But there is no way to say that the person playing the character is also the director. Because, the inheritance makes a character a person in general, not a particular person.
Problem:
As explained in Context, using inheritance to play more than one role cannot be considered, because a class could not play two roles at the same time in such a context (cf. the Inheritance Role Model).
The expectation is to have a model where a class could be seen as more than one concept or role, and where attributes specific to one of those concepts can be specified.
Solution:
A solution to the previous problem could be to use the Association Role Model, which could create an association between a person and a film. However, specific information on each role could not be stored in such a case. The role class model provides the flexibility of the association with role-specific attributes and even class operations, if needed.
This meta model - in Figure 2 - shows the role class like an element linking the Client and the BaseClass. For the Client interacting with the Role is like interacting with the Base Class itself, but from the perspective, it is expecting. The advantage having the role as a class is that attributes can be bound to it.
Solution:
Another situation where the Role pattern is interesting is when you've the following situation: Then you realise that as a contract holder, the Person has specific attributes. The holder UML role becomes a dedicated class ContractHolder with these specific attributes. Note that in that case that the multiplicity near Person and Contract are always 1. It means that you've one ContractHolder object for each association between a Contract and a Person.
Solution:
Real-world example Cinema A simple application of the role class model in a real example is in the 7th art (see Figure 3), the cinematography. This art involves a creation (the Film) and people to create it. Each person has a different role in the film, they could be actors and play characters, they could be director or scenarist, etc. A person is not limited to one role in a film, they can be both actors and directors and even more. For example, the film Scoop (2006) has been directed by Woody Allen, he is also the scenarist and he plays the role of Sid Waterman.
Solution:
In Figure 4, one can see in more detail the role that each person can play in a film. From the film, it is possible to ask the list of crews and cast that help elaborated it. Each person has one or more roles (e.g. actor, director, producer, cameraman, etc.) in the film and can participate in more than one film. A person could even be an actor in a film and a producer in another. One advantage of using a role class in the case of the actor role is that the character qualities can be stored within the role. This is true for the actor role, this is also true for other roles, however maybe not all.
Solution:
Only a few of the possible role have been modelled in Figure 4. One remark easily visible is that not all the role needs attributes and using the role class model for all of them is unnecessary (like for the Director role). In addition, there is a lot of redundancy between each role class. Redundancy in computer science means more work in maintenance, which is not wished.
Strengths and weaknesses:
The employment of this model depends on the business process. The analysis pattern "Role Class Model" offers a possibility to employ a model with linking between a base class and the client. In addition inheritance is not a part of the solution because of the flexibility of zero or multiple roles (role-specific attributes and operations).
Strength implies also its counterpart's weakness. The problem of the role class model is the redundancy, for example the method getName is visible in all of the role classes described in Figure 4. If this is considered inconvenient, the role class generalisation model as defined in Modelling Roles is a possible way to go.
Related links:
Actor-Role Pattern, A JPA Implementation https://web.archive.org/web/20071105232543/http://www.ibstaff.net/fmartinez/?p=16 | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**7-cubic honeycomb**
7-cubic honeycomb:
The 7-cubic honeycomb or hepteractic honeycomb is the only regular space-filling tessellation (or honeycomb) in Euclidean 7-space.
It is analogous to the square tiling of the plane and to the cubic honeycomb of 3-space.
There are many different Wythoff constructions of this honeycomb. The most symmetric form is regular, with Schläfli symbol {4,35,4}. Another form has two alternating 7-cube facets (like a checkerboard) with Schläfli symbol {4,34,31,1}. The lowest symmetry Wythoff construction has 128 types of facets around each vertex and a prismatic product Schläfli symbol {∞}(7).
Related honeycombs:
The [4,35,4], , Coxeter group generates 255 permutations of uniform tessellations, 135 with unique symmetry and 134 with unique geometry. The expanded 7-cubic honeycomb is geometrically identical to the 7-cubic honeycomb.
The 7-cubic honeycomb can be alternated into the 7-demicubic honeycomb, replacing the 7-cubes with 7-demicubes, and the alternated gaps are filled by 7-orthoplex facets.
Quadritruncated 7-cubic honeycomb A quadritruncated 7-cubic honeycomb, , contains all tritruncated 7-orthoplex facets and is the Voronoi tessellation of the D7* lattice. Facets can be identically colored from a doubled C~7 ×2, [[4,35,4]] symmetry, alternately colored from C~7 , [4,35,4] symmetry, three colors from B~7 , [4,34,31,1] symmetry, and 4 colors from D~7 , [31,1,33,31,1] symmetry. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Nitro (wireless networking)**
Nitro (wireless networking):
Nitro from Conexant (originally developed by Intersil) is a proprietary 802.11g performance enhancement technology introduced in 2003 as part of the PRISM chipset. The first implementation was designed to help compensate for the performance loss of higher-speed 802.11g devices when they share a wireless network with slower 802.11b devices.
Nitro (wireless networking):
Later implementations are marketed as Nitro MX Xtreme which adds proprietary frame-bursting, compression and point-to-point side session technology for a claimed 140 Mbit/s throughput transmission speed. The point-to-point side session technology, called DirectLink, creates a connection between clients or from a client to a media source, such as a media server, and avoids the access point. It does this while staying in 802.11 Infrastructure mode so the client can continue to utilize access point-based security and power-savings.
Alternatives:
Nitro is one of several competing incompatible proprietary extension approaches that were developed to increase performance of 802.11g wireless devices, such as 125 High Speed Mode from Broadcom, Super G (or "108 Mbit/s" technology) from Atheros, and MIMO-based extensions from Airgo Networks. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Mesotherapy**
Mesotherapy:
Mesotherapy (from Greek mesos, "middle", and therapy from Greek therapeia) is a form of alternative medicine which involves intradermal or subcutaneous injections of pharmaceutical preparations, enzymes, hormones, plant extracts, vitamins, and/or other ingredients such as hyaluronic acid. It has no proven clinical efficacy and poor scientific backing. Mesotherapy injections allegedly target adipose fat cells, apparently by inducing lipolysis, rupture and cell death among adipocytes. The stated aim of mesotherapy is to provide the skin with essential nutrients, hydration, and other beneficial compounds to rejuvenate and revitalize its appearance. The effects of the treatment may vary depending on the individual.Pressurized mesotherapy is a needle-free method that uses an accelerated jet of air to insert the ingredients into the skin tissue. A study on the effect of using a lipolytic substance inserted with needles compared to pressurized injection showed significant fat layer reduction for both methods but even better results with the pressurized injection system.
Usage:
In the United States, deoxycholic acid, under the brand name Kybella, is approved by the Food and Drug Administration for reducing moderate-to-severe fat below the chin. When injected into submental fat, deoxycholic acid helps destroy adipocytes (fat cells), which are metabolized by the body over the course of several months. Deoxycholic acid has not been approved for injection elsewhere in the body.
Usage:
There is no conclusive research proof that any chemical compounds work to target adipose (fat cells) specifically. Cell lysis, resulting from the detergent action of deoxycholic acid, may account for any clinical effect.
History:
Michel Pistor (1924–2003) performed clinical research and founded the field of mesotherapy. The French press coined the term mesotherapy in 1958. The French Académie Nationale de Médecine recognized mesotherapy as a specialty of medicine in 1987. The French Society of Mesotherapy recognizes its use as treatment for various conditions but makes no mention of its use in plastic surgery. Popular throughout European countries and South America, mesotherapy is practiced by approximately 18,000 physicians worldwide.
Criticism:
Physicians have expressed concern over the efficacy of mesotherapy, arguing that the treatment hasn't been studied enough to make a determination. Mesotherapy for the treatment of cosmetic conditions hasn't been the subject of standard clinical trials; however, the procedure has been studied for pain relief for several ailments, such as tendonitis, tendon calcification, dental procedures, cancer, cervicobrachialgia, arthritis, lymphedema, and venous stasis.Despite the lack of clinical trials, there have been case studies and medical papers written on mesotherapy as a cosmetic treatment.Rod Rohrich, M.D., chairman of the Department of Plastic Surgery at the University of Texas Southwestern Medical Center is quoted as saying: "There is simply no data, no science and no information, to my knowledge, that mesotherapy works." The American Society of Plastic Surgeons issued a position statement not endorsing mesotherapy.In the United States, the FDA cannot control the act of practitioners injecting various mixtures into patient's bodies, because this practice falls under the jurisdiction of state medical boards. Robin Ashinoff, speaking for the American Academy of Dermatology, wrote "A simple injection is giving people false hope. Everybody's looking for a quick fix. But there is no quick fix for fat or fat deposits or for cellulite." The American Society for Dermatologic Surgery informed its members in February 2005 that "further study is warranted before this technique can be endorsed.""No one says exactly what they put into the (syringe)," said Naomi Lawrence, a derma-surgeon at the University of Medicine and Dentistry of New Jersey. "One drug they often use, phosphatidylcholine, is unpredictable and causes extreme inflammation and swelling where injected. It is not a benign drug."Mesotherapy is currently banned in a number of South American countries. Even Brazil, which tends to be less strict than the US in drug approvals, has banned the drug for these purposes.In Australia, an alternative therapy salon was investigated by the Health Department after several clients developed skin abscesses on the calves, buttocks, thighs, abdomen, shoulders, face and neck after undergoing mesotherapy, with one patient also developing a mycobacterial infection.Following undesirable effects observed on several patients of a French practitioner, an official ratification was published in France in April 2011 to ban mesotherapy as a method for removing fat deposits. This ban was canceled in June 2011 by the French Council of State because the investigation proved that these undesirable effects weren't due to mesotherapy itself, but were due to unhygienic conditions.
Clinical studies:
In a prospective study, 10 patients underwent four sessions of facial mesotherapy using multivitamins at monthly intervals. This study found that there was no clinically relevant benefit for skin rejuvenation.Deoxycholic acid received FDA approval as an injectable to dissolve submental fat June 2015. This was based on the results of a phase III randomized trial of 2600 patients in which 68.2% of patients showed a response by measurement of the fat deposit; 81% had mild temporary adverse reactions of bruising, swelling, pain, numbness, erythema, and firmness around the treated area. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Early-onset parkinsonism-intellectual disability syndrome**
Early-onset parkinsonism-intellectual disability syndrome:
Early-onset parkinsonism-intellectual disability syndrome is a very rare genetic disorder which is characterized by intellectual disabilities, psychomotor developmental delays, macrocephaly, and Parkinson's disease which starts before the age of 45 (early onset PD). Additional symptoms include epilepsy, strabismus, and frontal bossing.
Causes:
This disorder is either caused by alterations or deletions of the RAB39B gene in chromosome Xq28 which are inherited in an X-linked recessive manner.
Epidemiology:
More than 12 cases from 3 families from Australia and the U.S. have been described in medical literature. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Castle (shogi)**
Castle (shogi):
In shogi, castles (Japanese: 囲い, romanized: kakoi) are strong defensive configurations of pieces that protect the king (Japanese: 玉).
In contrast to the special castling move in western chess, shogi castles are structures that require making multiple individual moves with more than one piece.
Introduction:
Usually the pieces involved in constructing castles are golds (Japanese: 金), silvers (Japanese: 銀), and pawns (Japanese: 歩). Typically, they also require moving the king from its starting position – often to the left or right side of the board.
Introduction:
The simplest castle involves two pieces and requires three moves, but it is more common to move at least three different pieces. For example, a simple Mino castle requires moving the king, the rook (Japanese: 飛), a silver, and two golds for a total of six moves. Others such as the Static Rook Bear-in-the-hole castle are more complex, which requires moving the king, a pawn, the bishop (Japanese: 角), a lance (Japanese: 香), a silver, and two golds for a total of twelve moves.
Introduction:
The lack of a castle and with the king in its start position is known by the term sitting king (Japanese: 居玉, romanized: igyoku), which is typically regarded negatively. However, there are a few strategies (often involving early attacks) that allow a sitting king (such as the Ureshino opening).
There are many types of castles and variations on those types which can be used, but it is important to understand which ones are useful in the current situation and how to compensate for their weak points.
Introduction:
As an example from a professional game, Shino Kumakura (Black, on bottom) used a very hard castle, a variant of a Left Mino castle with an extra dragon and gold reinforcement that was created after an aborted attempt at making an Bear-in-the-hole castle. She used this castle in a Static Rook Counter-Ranging Rook position (that is, her rook remained in its starting position in the opening). Her opponent, Fusako Ajiki (White) was using an Incomplete Mino castle (on the right side of her board) that has been attacked forcing the silver previously on 72 to move to 61. Ajiki's castle was used (as is typical) with Fourth File Rook, a type of Ranging Rook position.
Castle development:
There are piece development relations between castles. For instance, a basic Mino castle can be developed into a Silver Crown castle, a Gold Fortress castle can be developed into a Complete Fortress castle, a Boat castle into a Bear-in-the-hole castle, a Gold Excelsior castle into a Right Fortress castle, and so on.
Castles and opening types:
Certain castles are generally paired with certain openings. For example, if White is playing a Ranging Rook opening like Fourth File Rook, then White often uses a Mino (or related) castle on their right side of the board. A Fourth File Rook opening can be met with Black playing a Static Rook opening, which may often lead to Black building a Static Rook Bear-in-the-hole castle.
Fortress:
The Fortress castle (Japanese: 矢倉囲い, romanized: yagura gakoi) is considered by many to be the strongest defensive position in shogi in Double Static Rook games.A common Fortress structure is the Gold Fortress (Japanese: 金矢倉, romanized: kin yagura). It has a strongly protected king; a well-fortified line of pawns; and the bishop, rook, and a pawn all support a later attack by the rook's silver or knight. It is difficult to break down with a frontal assault, though it is weaker from the side. It is typically used against Static Rook openings that involve advancing the rook's pawn. However, one's opponent may just as easily adopt this defense, giving neither side an advantage.
Fortress:
Although the Gold Fortress is the most common form of Fortress, there are many variations of Fortress. A Fortress may be developed into a Fortress Bear-in-the-hole castle.
Helmet:
The Helmet or Headpiece (Japanese: カブト, romanized: kabuto) castle is a structure often used to protect the king while playing a Reclining Silver strategy usually in combination with a Bishop Exchange opening. The Helmet castle is structurally related to the Fortress castle and is also known as the Helmet Fortress (カブト矢倉 or Japanese: 兜矢倉, romanized: kabuto yagura).
Helmet:
If bishops have already been exchanged, then the silver that originated at 79 will have moved up to 77 via 88. And, for Reclining Silver, the right silver that originated at 39 will have reached the central file at 56 (through 38 and 47) with pawn on the fourth file moving up to 46 to make way for the silver.
Crab:
The Crab castle (Japanese: カニ囲い, romanized: kanigakoi) three generals 金銀金 gold-silver-gold lined up next to each other on rank 8 (or rank 2 for White) starting from the sixth to the central file. The king is moved one square to the left behind the middle silver.The crab name comes from the way the king at 69 can only move from side to side (79, 59).
Crab:
The Crab castle is used in Static Rook positions and also appears in handicap game positions played by Black (such as the 2-Piece handicap).
Furthermore, it may be possible to utilize the Crab castle in a Ranging Rook position in Double Ranging Rook games.
Crab:
When playing the Fortress opening, a Crab castle is usually constructed as a strong intermediate castle in the development of a Fortress castle. In these positions, the three pawns above the castle generals are advanced with the bishop in its start positions and the right silver is developed to the 48 square adjacent to the other generals so that the pieces are lined up as 角金銀金銀 bishop-gold-silver-gold-silver.
Bonanza:
The Bonanza castle (ボナンザ) is a castle that used to be built by the computer shogi engine Bonanza. It has some similarities with the Incomplete Fortress castle.
Snowroof:
Snowroof (also Snow Roof Fortress or Zigzag, Japanese: 雁木, romanized: gangi) castle has the left silver positioned on 67 and the two golds positioned on 78 and 58.
Typically, the right silver is also moved up to 57 as well making a four general castle.
Since a silver is placed on the 67 square, the sixth file pawn must be pushed forward to 66. Thus, Snowroof positions are characterized by having a closed bishop diagonal just as in traditional Ranging Rook positions and Fortress positions played by Black.
Snowroof:
In Snowroof, the bishop may be kept in situ (Japanese: 居角, romanized: ikaku) on the 88 square. In this case, the 86 square is not defended allowing the opponent to trade off rook pawns at any time in contrast to the Fortress castle and the Helmet castle (used in Bishop Exchange openings). If the eighth file pawn trade happens, the side pawn on 76 cannot be captured as it is defended by the 67-silver. Alternately, the bishop may be moved up to 77 so that it defends 86 preventing the eighth file pawn trade. However, once the bishop is on the 95–59 diagonal, then the Snowroof player's bishop may be traded off if the opponent pulls their bishop back to attack along the 31–97 diagonal. Thus, the Snowroof player must weigh the pros and cons of a rook pawn trade vs a bishop trade. Yet another common possibility has the bishop moving B-77, B-59 aiming for a position on the 37 or 25 squares so that it may be utilized on these diagonals.
Snowroof:
Silver Horns Snowroof Silver Horns Snowroof (Japanese: ツノ銀雁木, romanized: tsuno gin gangi) is a recent variant that positions the right silver on 47 instead of the usual 57.
This allows the possibility of moving the silver to the 56 square in a Reclining Silver position.
The silver horns name comes from the similar positioning of the two silvers on rank 7 flanking the central file on the sixth and fourth file that is found in the Central Rook Silver Horns variation. The horns metaphor is describing the way the two silvers extend out from the corners of the gold positioned on the 58 square.
Right King:
Right King (右玉 migi gyoku) Bishop Exchange Right King examples Yoshiharu Habu (White) used a Right King castle in a 2016 Ōi tournament game on September 12 against opponent Kazuki Kimura (Black). The opening was Bishop Exchange Double Reclining Silver.
Right King:
Although Habu had initially moved his king leftwards to the 42 square earlier in the game, he later moved his king rightwards (K-52, K-61, K-72) to form a Right King position. Additionally, his left silver that was earlier on the 33 square has moved after a pawn trade on the fourth file to the 53 square (via S-44) further strengthening the Right King castle.
Right King:
Kimura is using a Gold Fortress castle with his king on the 79 square.
Silver Horns Snowroof Right King examples Black's Silver Horns Snowroof Right KingBlack's Silver Horns Snowroof Right King 48-Gold variant
Central House:
Central House (shogi) (Japanese: 中住まい, romanized: nakazumai) is a castle characterized by the king being one rank above a sitting king position, that is, in the case of Black the king is moved to 58. While the positions of golds and silvers are not particularly fixed, the golds are often moved to 78 and 38, while the silvers are often moved to 68, 48 or 38.
Central House:
Putting more emphasis on a wide defense than on solidness, the goal of the player using this castle is to prevent the opponent from dropping pieces into their camp. Usually the player is also aiming for the same goal of dropping into the opponent's promotion zone. Therefore, the castle is often used Double Wing Attack openings and in the Aerial Battle variation of the Side Pawn Capture opening. In some rare cases, it is also used with Fortress openings and Double Ranging Rook as well as other uncommon openings (such as Takishita's Spread Golds opening).
Central House:
It's considered to be weak against attacks from above the king's position.
It used to be a popular castle among non-professional players playing "bench" shogi in the streets.
This castle is also called Spread Golds (Japanese: 金開き, romanized: kinbiraki), which is also another name for the Duck castle.
Central House game example A Kōji Tanigawa vs Kenji Waki game in an All Nihon Pro tournament from August 1993 shows Tanigawa (Black) using a Central House castle. The opening is the N-33 variation of the Side Pawn Capture opening.
Nakahara:
Nakahara (shogi) (Japanese: 中原囲い, romanized: Nakahara gakoi) The castle is named after Makoto Nakahara, for which he won the Kōzō Masuda Award in 1996. The Nakahara castle was originally part of the Nakahara Double Wing Attack, and consisted simply of the silver moving up from its initial position. Since the obtained position with the gold at 59 and the king at 69 resembled old-style Double Attack, Nakahara asked Yasujirō Kon, the teacher of his own teacher (Toshio Takayanagi), to teach him the basics of it. With this knowledge, Nakahara went on to apply it to modern strategy. A similar castle has been since discovered in an early game during the Edo period.
Nakahara:
While Nakahara developed it originally as a castle for sente (black), it is nowadays used almost exclusively by gote (white), particularly as this castle is played often along with the R-85 variation of Side Pawn Capture. The typical configuration involves S-22, G-32, K-41, G-51, and S-62. Although feeble in appearance, the main characteristic of this castle is that as the formation is low the king has plenty of routes to escape from attacks coming from right or left. While according to Nakahara this castle is less flexible compared to a Central House castle, thanks to its having a gold in the 1st. rank it is strong against both rook drops and knight attacks. Moreover, because it is easy to build up Nakahara thought it would be safe to presume that its use would become widespread.
Nakahara:
In recent years attention has been paid to its use for sente (black) in Side-Pawn Capture openings, and some research has been conducted about the solidness of the king, and following this research the Right Nakahara variation, where the position of the pieces on left and right of the king are reversed, has become rarely used.
Duck:
Duck or Duck Legs (アヒル ahiru) or Spread Golds (Japanese: 金開き, romanized: kinbiraki) is a Static Rook castle used in the surprise Duck opening.
Paperweight:
Paperweight castle (Japanese: 文鎮囲い, romanized: bunchingakoi) is a Static Rook castle used against Ranging Rook opponents in the Subway Rook opening (Japanese: 地下鉄飛車, romanized: chikatetsubisha).
It is named after the long row of pieces on rank 8, which is like the shape of traditional Japanese paperweights used to hold down parchment paper for brushwork calligraphy.
Truck:
Truck castle (Japanese: トラック囲い, romanized: torakkugakoi) is an uncommon Static Rook castle.
Boat:
The Boat castle (Japanese: 舟囲い or Japanese: 船囲い, romanized: funagakoi) is a Static Rook castle used against Ranging Rook, where the king moves next to the bishop and moves the right hand gold diagonally forward above the king's throne. This castle can also be an intermediary towards making stronger castles, such as Left Mino, Silver Crown or Bear-in-the-hole. This castle is often considered weak although Static Rook has the option of engaging in a rapid attack through various means, especially against Fourth File Rook and by making use of the left silver.
Boat:
A rapid attack is not guaranteed to be successful, since Ranging Rook will try to trade off the bishops and bring the game into a full-scale battle. This can lead static rook into a difficult game, because their Boat castle is too weak compared to the opponent's Mino castle. As such, Static Rook would rather resort to making stronger castles, such as Bear-in-the-hole or Left Mino.
Boat:
Daddy's Dearest Daddy's Dearest or Girl-In-The-House (Japanese: 箱入り娘, romanized: hakoiri musume, lit. 'daughter inside box') is a development from the Boat castle with the fifth file gold moving to the sixth file getting closer to the king.
Diamond The Diamond or Lozenge castle (Japanese: 菱囲い, romanized: hishigakoi) can be developed from a Boat castle by moving the left silver up to 68 and incorporating the right silver above the gold on 57. The Diamond is relatively stronger than the Boat.
Strawberry:
The Strawberry castle (Japanese: イチゴ囲い, romanized: Ichigo) is a simple way of castling that appears in Double Wing Attack openings. The Strawberry castle is used for Static Rook positions and has golds positioned on the 78 and 58 squares (like in the Snowroof castle) while the left silver remains in the start position so that it defends the bishop. The king is moved up and leftward to the 68 square. It is structurally identical to the Helmet castle before the bishops are exchanged.
Yonenaga King:
Yonenaga King castle (Japanese: 米長玉, romanized: Yonenaga gyoku) is used for Static Rook vs Ranging Rook games. This castle is named after Kunio Yonenaga.
This castle is similar to an Edge King Silver Crown.
The Yonenaga King variant show here is almost the same as a Left Silver Crown castle but with the king moved leftward one file to the edge. Thus, it may called by the name Yonenaga King Silver Crown (Japanese: 米長玉銀冠, romanized: Yonenaga gyoku ginkanmuri).
elmo:
Elmo (Japanese: エルモ, romanized: erumo or Left Mountain Japanese: 左山, romanized: hidari yama) castle is a Static Rook castle used against Ranging Rook positions. It is found in the computer shogi game records of the elmo shogi engine. The elmo engine (which is an eval function and a book file used with the YaneuraOu search engine) was the undefeated winner of the 2017 World Computer Shogi Championship beating the previously dominant Ponanza engine.
elmo:
This castle is characterized by the position of the king on K-78 (K-32 if played as White), silver on S-68 and gold on G-79 (or S-42 & G-31 for White).
Subsequently, the castle has been used by professional shogi players in 2018 and recently featured in a book on a new Anti-Ranging Rook Rapid Attack strategy.
Elephant Eye:
Silver Elephant Eye (Japanese: 銀象眼, romanized: gin zōgan) and Gold Elephant Eye (Japanese: 金象眼, romanized: kin zōgan) may be used in bishop handicap games.
Skewered Cutlet:
Skewered Cutlet castle (Japanese: 串カツ, romanized: kushikatsu) is used for Static Rook vs Ranging Rook games. It is named after a kushikatsu.
The Skewered Cutlet is structurally similar to the Static Rook Bear-in-the-hole, but unlike the latter, the positions of the king and the lance are reversed. This makes it look as if the king is skewered by the lance beneath, hence the origin of the name.
Skewered Cutlet:
Among its advantages is that since the king is away from the bishop's diagonal, it can easily escape towards the top from side attacks, and furthermore, that it can be formed in one less move than Bear-in-the-hole. In contrast, the lance is unable to defend the king, and since the king is on the lance file it prevents the lance from attacking (hence, none of its two typical functions can be used), and as a result it's weak to edge attacks, so it's a castle better known by its weaknesses than its strong points.
Skewered Cutlet:
Once the Skewered Cutlet castle has been formed, five further moves are required for it to convert into a Bear-in-the-hole castle. In contrast, it takes only two moves to convert into a Millennium castle, so care needs to be taken to use it properly depending on the circumstances.
Because of the king's position at 98, it's also possible to move to a Yonenaga King.
Bear-in-the-hole:
The Bear-in-the-hole castle Japanese: (穴熊, romanized: anaguma, lit. 'hole-bear') is a very common and often used in professional shogi.
This castle can be executed on either side of the board.
Mino:
The Mino castle (Japanese: 美濃囲い, romanized: minōgakoi) is a defensive position that is considered easier for beginners, but still popular with professionals. (Mino is a historical province of Japan.) The King is placed in a safe position, while the three generals work well to back each other up.
Silver Crown The Silver Crown castle (Japanese: 銀冠, romanized: ginkanmuri) is often a further development from Mino (via a High Mino castle).
Silver Crown is stronger than both Mino and High Mino from above.
Wall:
Wall castle (Japanese: 壁囲い, romanized: kabegakoi), also known as Quick Castle (Japanese: 早囲い, romanized: hayagakoi), is used for Static Rook vs Ranging Rook games. According to Hosking, it can also be called Edo Castle as it often appeared in Ranging Rook positions during the Edo period.The castle requires only three moves, and so, can be formed very quickly if under attack. And, for this reason, yet another name for this castle is Three-Move castle (Japanese: 三手囲い, romanized: sante gakoi). However, this name also refers to another simple castle constructed by three moves (see section below).
Wall:
(In Japanese, the term 早囲い hayagakoi also refers to Quick Fortress castle.) The Wall castle can develop later into the stronger Gold Mino with two moves. (That is, it requires five moves in total.) Wall game examples Although the Wall castle is often found in very old shogi games from the Edo period, it may occasionally be found in modern professional games.
Wall:
Yasumitsu Satō (Black) used the Wall castle in a 2017 NHK tournament on October 22 as shown in the adjacent diagram. The castle is paired with an Opposing Rook attacking formation.
Iijima is using a Bear-in-the-hole castle that has not yet been completed yet along with a Static Rook formation.
This game features aggressive attacks very early in the game, which partly explains the presence of the Wall castle instead of more complex Ranging Rook castles like Mino.
Cozy castle:
The Cozy castle or Ōsumi castle (Japanese: 大住囲い or 大隅囲い, romanized: Ōsumi gakoi) can be formed with only three moves (like the Wall castle), for example, in the case of Black (sente) castling to the right, K-48, K-38, G-48.
This castle also goes sometimes by the names of Three-Move castle (Japanese: 三手囲い, romanized: sante gakoi) or 早囲い hayagakoi. (Thus, this name is ambiguous since it can also refer to the Wall castle and rapid method of forming a Fortress castle.)
Small/Rapid Castle:
The Small or Rapid castle is another simple castle that can be formed by only four moves. This castle itself is not very common, but it can transition into a Gold Mino.
Another quick castle built in four moves has the silver on 48 and the gold on 59.
Flatfish:
The Flatfish castle (Japanese: 平目囲い or Japanese: ヒラメ囲い, romanized: hiramegakoi) is used in the Flatfish opening.
It is structurally similar to a Mino castle but with the two golds positioned adjacent to each other on the same bottom rank rather having the centermost gold on the same rank as the silver.
Millennium:
Millennium (shogi) (Japanese: ミレニアム, romanized: mireniamu) is a newer castle developed in response to the Fujii System (Japanese: 藤井システム, romanized: Fujii shisutemu) opening. It's a static rook strategy used against ranging rook strategies. The name "Millennium" is due to the fact that it first started to be deliberately played among professional players around the year 2000. It's also known as Kamakura castle, Kamaboko castle, or Tochka (Pillbox). Kunio Yonenaga is said to have been the first player to use it in the modern era (although, his using it was probably not deliberate). Hiroyuki Miura first started to use it, and his popularization of the tactic among pro players awarded him the Kōzō Masuda Award for innovation in shogi strategy in 2002. It is also suggested that the popularity of the castle occurred thanks to the internet activity among amateur players.
Millennium:
At the time, the Fujii System was making its fury felt, which unlike Bear-in-the-hole Static Rook made threats against the king difficult by way of the bishop and the knight, which consolidated it as a strong tactic. However, it is not as solid as the Bear-in-the-hole due to the number of moves it takes, and because of the time it takes to set up it could be taken advantage of by Ranging Rook hence showing a counter-measure against the formation of Bear-in-the-hole, a perfect countermeasure to the Fujii System had not been arrived at. Furthermore, as countermeasures against the Fujii System were established for both Bear-in-the-hole Static Rook strategies and Rapid Attack-type strategies, the use of this castle became less common after 2006.
Millennium:
The Millennium castle is characterized by the King being positioned in the place of the left knight, and surrounded by three (or four) golds and silvers. In terms of solidness, it is slightly inferior to Bear-in-the-hole, as solid as a Skewered Cutlet castle (Kushikatsu), and stronger than a Mino castle. Furthermore, the most important difference with Bear-in-the-hole is that since the king is not on the rival's bishop diagonal this makes it easy for the left knight to attack and capture.
Millennium:
From the point of view of defending the edge (i.e., the ninth file), compared to the Skewered Cutlet castle which defends it with silver and knight, the Millennium castle defends with silver and lance. By placing the king on the eight file (White's second file), it's more durable against edge attacks, and in contrast due to the distance from the center it can reach places that the Bear-in-the-hole and Skewered Cutlet castles cannot. Because of the king's position on rank 1, it can be said to be far or deep away from attacks from above, but it can hardly be said to be strong against this type of attacks, so this is also a weakness. Further, compared to the Bear-in-the-hole castle, due to its close proximity to the center, it shows weakness against attacks with promoted pawns. Some variations exist in order to make it stronger against attacks from above.
Aerokin:
This castle usually develops when one player tries to attack the other's Silver Crown from the side with rooks (or dragons).
Gold Excelsior:
Gold Excelsior or Peerless Golds (Japanese: 金無双, romanized: kinmusō) is a castle used in Double Ranging Rook openings. It has an alternate name of Two Golds or Twin Golds (Japanese: 二枚金, romanized: nimaikin) or Silver Wall.
Gold Excelsior:
From the point of view of Black, this castle is formed by moving the king to 38, the left gold to 58 and the right gold to 48. The most predominant feature is, of course, the fact that the two golds stand side by side, this also being the origin of the adjective "peerless" or "unrivalled" in the Japanese name of the castle (Japanese: 無双, romanized: musō). Because of this peculiarity, this castle makes it difficult to play a Central Rook strategy, as the position of the left gold prevents the rook from ranging back and forth freely along the central file.
Gold Excelsior:
All in all, as attacks from above are frequently the case in Double Ranging Rook games, the right silver is often moved to 28 so that it provides a way of defending against such attacks. This is not recommended, however, against horizontal attacks as the silver in that position easily turns into a wall that blocks the king's escaping route (hence the name "Silver Wall"). Therefore, the silver should either stay on 39, or move to 37.
Gold Excelsior:
Compared to Mino castles, the Gold Excelsior is stronger against attacks from above (especially those from the first and second file). It's somewhat weaker than Mino, however, against side attacks. Gold Excelsior is also weak against attacks from the fourth file, which is often called "the rabbit's ear." In the case of Static vs. Ranging Rook games, in which side attacks are typical, Mino castles are superior. In contrast, against side attacks in Double Ranging Rook games, Gold Excelsior is superior. However, positions where a silver wall is formed have been falling out of favor recently due to their weaknesses against Fortress castles, and hence Mino has become more predominant even in Double Ranging Rook games. Since Mino is particularly weak in the first and seconds files, it has problems against Opposing Rook, but is superior against Fourth File Rook and Third File Rook. Insofar as the silver does not need to moved up, Golden Excelsior is formed one move faster than Mino (hence why the king in Double Ranging Rook games is often left at 39 when playing Mino), and hence is effective in rapid attacks.
Gold Excelsior:
In the case of switching to a Fortress castle, Golden Excelsior can go to Incomplete Fortress in just one tempo, but it would lose one tempo to form a Complete Fortress. Therefore, leaving the right gold on 49 and make a boat castle variant (same gold formation, just opposite side) as an intermediate for the Fortress castle on the right hand side.
Mid-Rank King castles:
Aerial Tower Aerial Tower (Japanese: 空中楼閣, romanized: kūchū rōkaku) is a Mid-Rank King (Japanese: 中段玉, romanized: chūdan gyoku) type of castle in which the king is positioned on the middle ranks 4–6.
Fourth Rank Edge King Fourth Rank Edge King (Japanese: 四段端玉, romanized: yondan hashigyoku) is a Mid-Rank type of castle.
Mid-Rank King castles:
Fourth Rank Edge King examples In a Double Static Rook game from an April 1970 Meijin title match, challenger Renshō Nada (Black) used a Fourth Rank Edge King castle (which requires many moves to construct). Yasuharu Ōyama initially used a Snowroof-like structure for his castle that later developed in response to Nada's position. Ōyama has dropped a pawn inside of Nada's camp on the 67 square, which Nada cannot easily attack. Later in the game, Nada was able to move his king to an entering king state. However, ultimately, after an exhausted attack on Ōyama's king, Nada resigned on the 185th move.
Mid-Rank King castles:
Another Double Static Rook Nada vs Ōyama game features a somewhat different castle form by Black that resembles a Fourth Rank Edge King castle. Black's castle was originally a Snowroof castle. White started with a Gold Fortress castle that developed into a Complete Fortress and then a Fortress Bear-in-the-hole. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Α-Aminoadipate pathway**
Α-Aminoadipate pathway:
The α-aminoadipate pathway is a biochemical pathway for the synthesis of the amino acid L-lysine. In the eukaryotes, this pathway is unique to the higher fungi (containing chitin in their cell walls) and the euglenids. It has also been reported from bacteria of the genus Thermus.
Pathway overview:
Homocitrate is initially synthesised from acetyl-CoA and 2-oxoglutarate by homocitrate synthase. This is then converted to homoaconitate by homoaconitase and then to homoisocitrate by homoisocitrate dehydrogenase. A nitrogen atom is added from glutamate by aminoadipate aminotransferase to form the α-aminoadipate from which this pathway gets its name. This is then reduced by aminoadipate reductase via an acyl-enzyme intermediate to a semialdehyde. Reaction with glutamate by one class of saccharopine dehydrogenase yields saccharopine which is then cleaved by a second saccharopine dehydrogenase to yield lysine and oxoglutarate.
α-Aminoadipic acid:
α-Aminoadipic acid is the conjugate acid of α-aminoadipate, the latter of which is the prevalent form at physiological pH. A 2013 study identified α-Aminoadipic acid (2-aminoadipic acid) as a novel predictor of the development of diabetes and suggested that it is a potential modulator of glucose homeostasis in humans. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Carbonyl bromide**
Carbonyl bromide:
Carbonyl bromide, also known as bromophosgene, is an organic chemical compound with the chemical formula COBr2. It is a colorless liquid. It is a bromine analogue of phosgene. It is a carbon oxohalide. Carbonyl bromide is a decomposition product of halon compounds used in fire extinguishers.
Synthesis and reactions:
Carbonyl bromide is formed by the oxidation carbon tetrabromide with sulfuric acid: CBr4 + H2SO4 → COBr2 + SO2 + Br2 + H2OIn contrast to phosgene, carbonyl bromide cannot be produced efficiently by halogenation of carbon monoxide. The bromination of carbon monoxide follows this equation: CO + Br2 ⇌ COBr2But the process is slow at room temperature. Increasing temperature, in order to increase the reaction rate, results in a further shift of the chemical equilibrium towards the educts (since ΔRH < 0 and ΔRS < 0).Carbonyl bromide slowly decomposes to carbon monoxide and elemental bromine even at low temperatures. It is also sensitive to hydrolysis, breaking down into hydrogen bromide, water and carbon dioxide. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Supergranulation**
Supergranulation:
Supergranulation is a particular pattern of convection cells on the Sun's surface called supergranules. It was discovered in the 1950s by A.B.Hart[1] using Doppler velocity measurements showing horizontal flows on the photosphere (flow speed about 300 to 500 m/s, a tenth of that in the smaller granules). Later work (1960s) by Leighton, Noyes and Simon established a typical size of about 30000 km for supergranules with a lifetime of about 24 hours.
Origin:
Supergranulation has long been interpreted as a specific convection scale, but its origin is not precisely known. Although the presence of granules in the solar photosphere is a well-documented phenomenon, there is still much debate on the true nature or even the existence of higher-order granulation patterns. Some authors suggest the existence of three distinct scales of organization: granulation (with typical diameters of 150–2500 km), mesogranulation (5000–10000 km) and supergranulation (over 20000 km). Granules are typically considered as being signs of convective cells forming a hierarchic structure: supergranules would be thus fragmented in their uppermost layers into smaller mesogranules, which in turn would split into even smaller granules at their surface. The solar material would flow downward in dark "lanes" separating granules with the divisions between supergranules being the biggest concentrations of cold gas, analogous to rivers connecting smaller tributaries. It should however be stressed that this picture is highly speculative and might turn out to be false in the light of future discoveries. Recent studies show some evidence that mesogranulation was a ghost feature caused by averaging procedures. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Sutimlimab**
Sutimlimab:
Sutimlimab, sold under the brand name Enjaymo, is a monoclonal antibody that is used to treat adults with cold agglutinin disease (CAD). It is given by intravenous infusion. Sutimlimab prevents complement-enhanced activation of autoimmune human B cells in vitro.The most common side effects include headache, high blood pressure, urinary tract infection (infection of the structures that carry urine), upper respiratory tract infection (nose and throat infection), nasopharyngitis (inflammation of the nose and throat), nausea, abdominal pain, infusion-related reactions and cyanosis (bluish discoloration of hands and feet in response to cold and stress).This drug is being developed by Bioverativ, a Sanofi company. Sutimlimab was approved for medical use in the United States in February 2022, and in the European Union in November 2022. The US Food and Drug Administration (FDA) considers it to be a first-in-class medication.
Medical uses:
Sutimlimab is indicated to decrease the need for red blood cell transfusion due to hemolysis (red blood cell destruction) in adults with cold agglutinin disease (CAD).
Adverse effects:
The most common side effects include respiratory tract infection, viral infection, diarrhea, dyspepsia (indigestion), cough, arthralgia (joint stiffness), arthritis, and swelling in the lower legs and hands.
Pharmacology:
Mechanism of action Sutimlimab targets the C1s enzyme and inhibits its enzymatic propagation of the classical complement pathway, thereby, preventing the formation of the C3-convertase enzyme.
History:
The effectiveness of sutimlimab was assessed in a study of 24 adults with cold agglutinin disease who had a blood transfusion within the past six months. All participants received sutimlimab for up to six months and could choose to continue therapy in a second part of the trial. Based on body weight, participants received either a 6.5g or 7.5g infusion of sutimlimab into their vein on day 0, day 7, and every 14 days through week 25.In total, 54% of participants responded to sutimlimab. The response was defined in the study as an increase in hemoglobin (an indirect measurement of the amount of red blood cells that are not destroyed) of 2 g/dL or greater (or to 12 g/dL or greater), and no red blood cell transfusions after the first five weeks of treatment; and no other therapies for cold agglutinin disease as defined in the study.The U.S. Food and Drug Administration (FDA) granted the application for sutimlimab orphan drug, breakthrough therapy, and priority review designations.
Society and culture:
Legal status On 15 September 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Enjaymo, intended for the treatment of hemolytic anemia in adults with cold agglutinin disease (CAD). The applicant for this medicinal product is Genzyme Europe BV. Sutimlimab was approved for medical use in the European Union in November 2022.
Society and culture:
Names Sutimlimab is the International nonproprietary name (INN). | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Aeronautical operational control**
Aeronautical operational control:
Aeronautical operational control (AOC) is a group or the entirety of applications used for communication of an aircraft with its airline or service partners on the ground. An AOC application was traditionally hosted on an ACARS MU or Communications Management Unit (CMU). AOC communication is required for the exercise of authority over the initiation, continuation, diversion or termination of flight for safety, regularity and efficiency reasons.AOC were often user-defined, because they were only exchanged between an airline and its own aircraft; controlling both ends, there was no need for standardization.However, by introducing airframe-defined ACARS messages (e.g. the Airbus A380) and because of the increasing need to connect airline handling partners such as fuel suppliers or de-icing companies, a need to standardize appeared. In 2007, ARINC 633 was created developed to standardize these AOC messages. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**INK4**
INK4:
INK4 is a family of cyclin-dependent kinase inhibitors (CKIs). The members of this family (p16INK4a, p15INK4b, p18INK4c, p19INK4d) are inhibitors of CDK4 (hence their name INhibitors of CDK4), and of CDK6. The other family of CKIs, CIP/KIP proteins are capable of inhibiting all CDKs. Enforced expression of INK4 proteins can lead to G1 arrest by promoting redistribution of Cip/Kip proteins and blocking cyclin E-CDK2 activity. In cycling cells, there is a resassortment of Cip/Kip proteins between CDK4/5 and CDK2 as cells progress through G1. Their function, inhibiting CDK4/6, is to block progression of the cell cycle beyond the G1 restriction point. In addition, INK4 proteins play roles in cellular senescence, apoptosis and DNA repair.INK4 proteins are tumor suppressors and loss-of-function mutations lead to carcinogenesis.INK4 proteins are highly similar in terms of structure and function, with up to 85% amino acid similarity. They contain multiple ankyrin repeats.
Genes:
The INK4a/ARF/INK4b locus encodes three genes (p15INK4b, ARF, and p16INK4a) in a 35-kilobase stretch of the human genome. P15INK4b has a different reading frame that is physically separated from p16INK4a and ARF. P16INK4a and ARF have different first exons that are spliced to the same second and third exon. While those second and third exons are shared by p16INK4a and ARF, the proteins are encoded in different reading frames meaning that p16INK4a and ARF are not isoforms, nor do they share any amino acid homology.
Evolution:
Polymorphisms of the p15INK4b/p16INK4a homolog were found to segregate with melanoma susceptibility in the Xiphophorus indicating that INK4 proteins have been involved with tumor suppression for over 350 million years. Furthermore, the older INK4-based system has been further bolstered by the evolution of the recent addition of the ARF-based anti-cancer response.
Function:
INK4 proteins are cell-cycle inhibitors. When they bind to CDK4 and CDK6, they induce an allosteric change that leads to the formation of CDK-INK4 complexes rather than CDK-cyclin complexes. This leads to an inhibition of retinoblastoma (Rb) phosphorylation downstream. Therefore, the expression of p15INK4b or p16INK4A keeps the Rb-family proteins hypophosphorylated. This allows the hypophosphorylated Rb to repress transcription of S-phase genes causing cell cycle arrest in the G1 phase.
Subsets:
P16INK4a P16 is formed from four ankyrin repeat (AR) motifs that exhibit a helix-turn-helix conformation except that the first helix in the second AR consists of four residues. P16 regulation involves epigenetic control and multiple transcription factors. PRC1, PRC2, YY1, and Id1 play a role in the suppression of p16INK4A expression and transcription factors CTCF, Sp1, and ETs activate p16INK4A transcription. In knockout experiments, it was found that mice lacking just p16INK4a were more prone to spontaneous cancers. Mice lacking both p16INK4a and ARF were found to be even more tumor prone than the mice lacking just p16INK4a.
Subsets:
P15INK4b P15 is also formed from four ankyrin repeat (AR) motifs. Expression of P15INK4b is induced by TGF-b indicating its role as a potential downstream effector of TGF-b mediated growth arrest.
Subsets:
P18INK4c P18INK4c has been shown to play an important role in modulating TCR-mediated T cell proliferation. The loss of p18INK4c in T cells reduced the requirement of CD28 costimulation for efficient T cell proliferation. Other INK4 family members did not affect this process. Furthermore, it was shown that p18INK4c is preferentially inhibitory to CDK6, but not CDK4 activity in activated T cells that suggest p18INK4c may set an inhibitory threshold in resting T cells.
Clinical significance:
Role in cancer Cells containing oncogenic mutations in-vivo often responded by activating the INK4A/ARF/INK4B locus that encodes the INK4 tumor suppressor proteins. The unusual genomic arrangement of the INK4a/ARF/INK4b locus functions as a weakness in our anti-cancer defenses. This is due to the fact that three crucial regulators of the RB and p53 (regulated by ARF) are vulnerable to one single, small deletion. This observation yields two possible opposing conclusions: Either tumor formation does not provide any evolutionary selection pressure because the overlapping INK4a/ARF/INK4b is not selected against or tumorigenesis provides such a strong pressure, that an entire group of genes has been selected for at the INK4a/ARF/INK4b locus to prevent cancer. The response of the INK4a/ARF/INK4b locus efficiently prevents cancers that could occur to the constant oncogenic mutations that occur in long-lived mammals.
Clinical significance:
When the INK4a/ARF/INK4b locus was overexpressed, the mice demonstrated a 3-fold reduction in the incidence of spontaneous cancers. This evidence further indicated that the INK4a/ARF/INK4b locus in mice plays a role in tumor suppression.
Clinical significance:
Role in aging The INK4 family has been implicated in the aging process. The expression of p16INK4a increases with aging in many tissues of rodents and humans. It was also shown that INK4a/ARF deficient animals increase an age-related decline in T-cell responsiveness to CD3 and CD28, which is a hallmark of aging. Furthermore, neural stem cells from Bmi-1- deficient animals demonstrate increased INK4a/ARF expression and impaired regenerative potential. The phenotype; however, can be rescued by p16INK4a deficiency implying that while p16INK4a can potentially be used as a biomarker of physiologic, rather than chronologic age, it is also an effector of aging. The mechanism by which it does this is by limiting the self-renewal capacity of disparate tissues such as lymphoid organs, bone marrow, and the brain.
Regulation of INK4 expression:
Initially, it was thought that each INK4 family member was structurally redundant and equally potent. It was later found; however, that INK4 family members are differentially expressed during mouse development. The diversity in expression pattern indicates that the INK4 gene family may have cell lineage-specific or tissue-specific functions. Evidence has shown that INK4a/ARF expression increase at an early stage of tumorigenesis, but the precise stimuli relevant to cancer that induces the expression of the locus is unknown. Expression of p15INK4b does not correlate with p16INK4a in many normal rodent tissues. Induction and repression of p15INK4b; however, has been noted in response to a few signaling events such as RAS activation, that also induce INK4/ARF expression.
Regulation of INK4 expression:
RAS activation might lead to increased INK4/ARF expression potentially through ERK-mediated activation of Ets1/2 to induce p16INK4. A few repressors of INK4a/ARF/INK4b expression have been identified as well. T box proteins and the polycomb group have been shown to repress p16INK4a, p15INK4b, and ARF. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cylindrical σ-algebra**
Cylindrical σ-algebra:
In mathematics — specifically, in measure theory and functional analysis — the cylindrical σ-algebra or product σ-algebra is a type of σ-algebra which is often used when studying product measures or probability measures of random variables on Banach spaces.
For a product space, the cylinder σ-algebra is the one that is generated by cylinder sets.
Cylindrical σ-algebra:
In the context of a Banach space X, the cylindrical σ-algebra Cyl (X) is defined to be the coarsest σ-algebra (that is, the one with the fewest measurable sets) such that every continuous linear function on X is a measurable function. In general, Cyl (X) is not the same as the Borel σ-algebra on X, which is the coarsest σ-algebra that contains all open subsets of X. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Run queue**
Run queue:
In modern computers many processes run at once. Active processes are placed in an array called a run queue, or runqueue. The run queue may contain priority values for each process, which will be used by the scheduler to determine which process to run next. To ensure each program has a fair share of resources, each one is run for some time period (quantum) before it is paused and placed back into the run queue. When a program is stopped to let another run, the program with the highest priority in the run queue is then allowed to execute.
Run queue:
Processes are also removed from the run queue when they ask to sleep, are waiting on a resource to become available, or have been terminated.
Run queue:
In the Linux operating system (prior to kernel 2.6.23), each CPU in the system is given a run queue, which maintains both an active and expired array of processes. Each array contains 140 (one for each priority level) pointers to doubly linked lists, which in turn reference all processes with the given priority. The scheduler selects the next process from the active array with highest priority. When a process' quantum expires, it is placed into the expired array with some priority. When the active array contains no more processes, the scheduler swaps the active and expired arrays, hence the name O(1) scheduler.
Run queue:
In UNIX or Linux, the sar command is used to check the run queue.
The vmstat UNIX or Linux command can also be used to determine the number of processes that are queued to run or waiting to run. These appear in the 'r' column.
Run queue:
Example: $ vmstat procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 2 0 0 4579152 324416 4619528 0 0 402 236 3357 15 20 2 78 0 0 There are two models for Run queues: one that assigns a Run Queue to each physical processor, and the other has only one Run Queue in the system | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**SXBL**
SXBL:
sXBL (SVG's XML Binding Language) is a mechanism for defining the presentation and interactive behavior of elements described in a namespace other than SVG's (an XML language supporting vector graphics, user events and scripted behavior). sXBL is very similar to XBL, as it does for SVG documents what XBL does for XUL documents. For example, it is possible to define a generic scrollArea in sXBL and use it in SVG documents.
History, objectives, and future:
sXBL specification derived from a specification called RCC (Rendering Custom Content) that was embedded in a 2003 working draft of the SVG 1.2 specification. The RCC part of the specification has since been removed in favor of the sXBL more modular approach.
History, objectives, and future:
As stated in the sXBL working draft: sXBL is intended to be an SVG-specific first version of a more general-purpose XBL specification (e.g., "XBL 2.0"). The intent is that, in the future, a general-purpose and modularly-defined XBL specification will be developed which will replace this specification and will define additional features that are necessary to support scenarios beyond SVG, such as integration into web browsers that support CSS. Once a general-purpose XBL is defined, sXBL would just become an SVG-specific subset (i.e., a profile) of the larger XBL specification.
History, objectives, and future:
Even if sXBL has borrowed a lot from XBL, there are some differences between these two standards (for example, the name of some of the elements are different).
However, there are also some subtle differences between the current state of the Mozilla XBL 2.0 working draft and the current state of the sXBL working draft.
As the sXBL specification has not evolved since the last working draft in August 2005, and since the September 2006 release of the XBL 2.0 last call working draft, it seems that sXBL will be dropped in favour of the more general XBL 2.0 approach.
Implementations:
sXBL is a W3C working draft, and has not yet reached the status of a recommendation. However, the Batik SVG Toolkit, a Java library that can be used to render, generate, and manipulate SVG graphics, has a preliminary "almost full" implementation of the current state of the sXBL specification in its code base. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Dose profile**
Dose profile:
In external beam Radiotherapy, transverse and longitudinal dose measurements are taken by a radiation detector in order to characterise the radiation beams from medical linear accelerators. Typically, an ionisation chamber and water phantom are used to create these radiation dose profiles. Water is used due to its tissue equivalence. Transverse dose measurements are performed in the x (crossplane) or y (inplane) directions perpendicular to the radiation beam, and at a given depth (z) in the phantom. These are known as dose profiles.
Dose profile:
Dose measurements taken along the z direction create radiation dose distribution known as a depth-dose curve. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Test tube**
Test tube:
A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top and closed at the bottom.
Test tubes are usually placed in special-purpose racks.
Types and usage:
Chemistry Test tubes intended for general chemical work are usually made of glass, for its relative resistance to heat. Tubes made from expansion-resistant glasses, mostly borosilicate glass or fused quartz, can withstand high temperatures up to several hundred degrees Celsius.
Chemistry tubes are available in a multitude of lengths and widths, typically from 10 to 20 mm wide and 50 to 200 mm long. The top often features a flared lip to aid pouring out the contents.
A chemistry test tube typically has a flat bottom, a round bottom, or a conical bottom. Some test tubes are made to accept a ground glass stopper or a screw cap. They are often provided with a small ground glass or white glaze area near the top for labelling with a pencil.
Test tubes are widely used by chemists to handle chemicals, especially for qualitative experiments and assays. Their spherical bottom and vertical sides reduce mass loss when pouring, make them easier to wash out, and allow convenient monitoring of the contents. The long, narrow neck of test tube slows down the spreading of gases to the environment.
Types and usage:
Test tubes are convenient containers for heating small amounts of liquids or solids with a Bunsen burner or alcohol burner. The tube is usually held by its neck with a clamp or tongs. By tilting the tube, the bottom can be heated to hundreds of degrees in the flame, while the neck remains relatively cool, possibly allowing vapours to condense on its walls. A boiling tube is a large test tube intended specifically for boiling liquids.
Types and usage:
A test tube filled with water and upturned into a water-filled beaker is often used to capture gases, e.g. in electrolysis demonstrations.
A test tube with a stopper is often used for temporary storage of chemical or biological samples.
Biosciences Culture tubes are test tubes used in biology and related sciences for handling and culturing all kinds of live organisms, such as molds, bacteria, seedlings, plant cuttings, etc.. Some racks for culture tubes are designed to hold the tubes in a nearly horizontal position, so as to maximize the surface of the culture medium inside.
Types and usage:
Culture tubes for biology are usually made of clear plastic (such as polystyrene or polypropylene) by injection molding and are often discarded after use. Plastic test tubes with a screwtop cap are often called "Falcon tubes" after a line manufactured by Becton Dickinson.Some sources consider that the presence of a lip is what distinguishes a test tube from a culture tube.
Types and usage:
Clinical medicine In clinical medicine, sterile test tubes with air removed, called vacutainers, are used to collect and hold samples of physiological fluids such as blood, urine, pus, and synovial fluid. These tubes are commonly sealed with a rubber stopper and often have a specific additive placed in the tube with the stopper color indicating the additive. For example, a blue-top tube is a 5 ml test tube containing sodium citrate as an anticoagulant, used to collect blood for coagulation and glucose-6-phosphate dehydrogenase testing. Small vials used in medicine may have a snap-top (also called a hinge cap) molded as part of the vial.
Types and usage:
Other uses Test tubes are sometimes put to casual uses outside of lab environments, e.g. as flower vases, glassware for certain weak shots, or containers for spices. They can also be used for raising queen ants during their first months of development.
Variants:
Boiling tube A boiling tube is a small cylindrical vessel used to strongly heat substances in the flame of a Bunsen burner. A boiling tube is essentially a scaled-up test tube, being about 50% larger.
Variants:
They are designed to be wide enough to allow substances to boil violently as opposed to a test tube, which is too narrow; a boiling liquid can explode out of the end of test tubes when they are heated, as there is no room for bubbles of gas to escape independently of the surrounding liquid. This phenomenon is called bumping.
Variants:
Ignition tube An ignition tube is used in much the same way as a boiling tube, except it is not as large and thick-walled. It is primarily used to hold small quantities of substances which are undergoing direct heating by a Bunsen burner or other heat source. This type of tube is used in the sodium fusion test.
Ignition tubes are often difficult to clean due to the small bore. When used to heat substances strongly, some char may stick to the walls as well. They are usually disposable. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Universal powerline bus**
Universal powerline bus:
Universal Powerline Bus (UPB) is a proprietary software protocol developed by Powerline Control Systems for power-line communication between devices used for home automation. Household electrical wiring is used to send digital data between UPB devices via pulse-position modulation.Communication is peer to peer, with no central controller necessary.UPB addressing allows 250 devices per house and 250 houses per transformer, allowing over 62,500 total device addresses and can co-exist with other powerline carrier systems within the same home.As of 2018, UPB enjoys one of the broadest range of device types when compared to most protocols and has support from some major manufacturers in the home automation space. Most notably, Leviton and their Omni series of home automation products, as well as the UPB devices they market. UPB is also supported by many major home automation software manufacturers. A few of which are listed below.
Reliability:
UPB is a highly reliable protocol for home automation. It is not susceptible to RF interference, signal blockage by walls or short distance broadcast issues like some wireless protocols. UPB transmits on the building's existing wiring and has extensive noise reduction circuitry. This allows it to traverse long distances without issues, even across multiple electrical panels, making it ideal for very large homes. Appliances that have traditionally plagued X10 devices, usually do not affect UPB. In fact, UPB signals can reliably be received by the target device even with significant amounts of electrical noise on the power lines. However, in the event that an appliance in your home causes extreme interference when operating, an inexpensive wire-in noise filter can be applied at the circuit breaker panel to solve the issue.
Interoperability:
As of 2020, control of UPB devices is supported by the Home Assistant open source software (in version 0.110 and later).As of 2017, control of UPB devices is supported by the OpenHAB open source software.HomeSeer is a well known commercial home automation software package that has support for UPB.
Mobile App support (IOS and Android) is available by using the PulseWorx Gateway (PGW) plug-in module.
Voice recognition products such as Alexa, Automated Living's HAL and Google's Assistant are supported either directly or indirectly through a device or automation controller.
Interoperability:
UPB can coexist with other powerline technologies. It can also interoperate with other automation devices that use RF (for example) through the use of a multi protocol automation controller (See Leviton Omni, HomeSeer devices). This allows for a mixed technology automation system to achieve best in class devices from many manufacturers. However, it is interesting to note that unlike most wireless protocols, UPB does not require an automation controller or hub to operate.
Interoperability:
Since UPB is a peer to peer protocol, individual switches, scene controllers and various types of plug-in modules can be individually programmed to do multiple tasks without the need to purchase a hub or controller. Some examples of actions that can be achieved without a hub or controller would be: timed shutoff of a bathroom fan (timer plug-in module or a switch with timer feature built-in), lights turning on or off based on a photocell's sensing of sunlight (I/O plug-in module), turning on one set of lights with a single tap of the switch and turning on another set of lights or devices on a double tap of the switch (dimmer switch). Turning on/off a Hot Tub (load controller switch), multiple preset light dimming settings (scene controller switch), turn on/off a motorized device (relay switch).
Interoperability:
Scene controllers with built in Infrared (IR) sensors are available. This allows for a single programmable remote control (universal remote) like those made by Logitech to control both your lighting and your television or other media devices.
Hardware Manufacturers:
The following is a list of UPB device manufacturers. This is not a comprehensive list: Advanced Quonset Technologies Leviton HLC line Powerline Control Systems PulseWorx line Simply Automated Web Mountain WGL Designs | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Ecotechnics**
Ecotechnics:
Ecotechnics is defined as the 'techne' of bodies. Ecotechnics thinks of the body as a technology which makes possible the inclusion of a whole new range of bodies. This gives people more agency and biopower over their own use of their bodies. This makes it usable for queer theory and disability studies. An interpretation also refers to the term as the craft of the home.In classifying the body as a technical object, Jean-Luc Nancy explained how it works by partitioning bodies into their own zones and spaces, which also allow such bodies to connect with other bodies. Hence, Nancy claims that technology determine our interactions with other beings in the world. Ecotechnics is also central in Sullivan's and Murray's collection of essays Queering the Technologisation of Bodies. It is built on Bernard Stiegler's work that sees the body and technology as a double process: the technology and the body are informed by each other. Derrida who extends on both Nancy and Stiegler's ideas argues that the 'proper body' implicates interconnections of technical additions. Ecotechnics goes against the essentialist and binary notion of the body as a technological object which positions it within post-structuralism. The body can only be understood within its environment and this environment is a technical one.
Ecotechnics:
Nancy also applied the ecotechnics concept to contemporary issues such as war and globalization. He maintained, for instance, that modern conflicts are produced by the dividing lines between: North and South; rich and poor; and, integrated and excluded. He also believes that ecotechnics is undoing communities due to the elimination of the polis and the prevalence of oikos, calling for a global sovereignty that would administer the world as a single household. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Stone skipping**
Stone skipping:
Stone skipping and stone skimming are considered related but distinct activities: both refer to the art of throwing a flat stone across the water in such a way (usually sidearm) that it bounces off the surface. The objective of "skipping" is to see how many times a stone can bounce before it sinks into the water; the objective of "skimming" is to see how far a bouncing stone can travel across the water before it sinks into the water. In Japan, the practice is referred to as Mizu Kiri, which loosely translates to "water cutting". In Mizu Kiri contests, both skimming and skipping principles, as well as a throw's overall aesthetic quality, are taken into account to determine the winners.
History:
The act of skipping stones was mentioned by Marcus Minucius Felix in his dialogue Octavius, in which he described children playing a game on the beach. Greek scholar Julius Pollux also noted the game in Onomastikon. Among the first documented evidence stone skipping as a sport was in England, where it was described as "Ducks and Drakes" in 1583. An early explanation of the physics of stone-skipping was provided by Lazzaro Spallanzani in the 18th century.
History:
Records The world record for the number of skips, according to the Guinness Book of Records, is 88, by Kurt "Mountain Man" Steiner. The cast was achieved on September 6, 2013, at Red Bridge in the Allegheny National Forest, Pennsylvania. The previous record was 65 skips, by Max Steiner (no relation), set at Riverfront Park, Franklin, Pennsylvania. Before him, the record was 51 skips, set by Russell Byars on July 19, 2007, skipping at the same location. Kurt Steiner also held the world record between 2002 and 2007 with a throw of 40 skips, achieved in competition in Franklin, PA.
History:
The Guinness World Record for the furthest distance skimmed using natural stone stands at 121.8m for men, established by Dougie Isaacs (Scotland), and 52.5m for women, thrown by Nina Luginbuhl (Switzerland). These records were made on 28 May 2018 at Abernant Lake, Llanwrtyd Wells, Powys, Wales.
There are several stone skimming championships held. The record for most World Championship wins also sits with Dougie Isaacs (Scotland), with 8 Men's World Stone Skimming Championship wins (2005, 2007, 2010, 2011, 2013, 2014, 2015, 2016) and the Women's World Stone Skimming Championship wins record sits with Lucy Wood (England) with 5 wins (2012, 2013, 2015, 2016, 2018).
Championships:
The "Big Four" American stone skipping contests include (in order of establishment and participant rankings): The Mackinac Island championship, held on July 4 in northern Michigan (entry by invite only; must win prior Mackinac Open or Pennsylvania Qualifier to enter); The Pennsylvania championship, held usually the 3rd Saturday of August in Franklin, PA, about one hour southeast of Erie (winners invited to the subsequent Michigan contest); The Vermont championship (about one month after Pennsylvania) on the shore of Lake Paran, North of Bennington; and The Great Southern championship in Arkansas (Labor Day weekend).Former world champion Coleman-McGhee founded the North American Stone Skipping Association (NASSA) in 1989 in Driftwood, Texas. NASSA-sanctioned world championships were held from 1989 through 1992 in Wimberley, Texas. The next official NASSA World Championship is expected to be held at Platja d'en Ros beach in Cadaqués, Catalonia, Spain..
Championships:
A stone skimming championship takes place every year in Easdale, Scotland, where relative distance counts as opposed to the number of skips, as tends to be the case outside of the US. The event was run for more than 20 years by Donald Melville, who is seen as having done more for the sport than anyone. Since 1997, competitors from all over the world have taken part in the World Stone Skimming Championships (WSSC) in a disused water-filled quarry on Easdale Island using sea-worn Easdale slate of maximum 3" diameter. Each participant gets three throws and the stone must bounce/skip at least twice to count (i.e. 3 water touches minimum).. The event featured in the 2019 BBC Scotland documentary Sink or Skim. The WSSC for 2020-2022 were cancelled due to coronavirus concerns. The next is scheduled for Sept 2023.
Championships:
Other domestic distance-based championships in the UK are currently the Welsh and British, but they were cancelled in 2020 and 2021 for reasons including the COVID-19 pandemic. The British is next due to be held in 2023. Japan holds competitions where both skimming and skipping principles, as well as a throw's overall aesthetic quality, are taken into account to determine the winners. At present, there is also a competition at Ermatingen in Switzerland and occasionally in the Netherlands (both skimming/distance-based).
Championships:
Men's World Skimming Championship winners by year 2020, 2021 and 2022 Championships cancelled due to aspects of the COVID-19 pandemic.
Women's World Skimming Championship winners by year 2020, 2021 and 2022 Championships cancelled due to the COVID-19 pandemic.
Underlying physics:
Although stone skipping occurs at the air-water interface, surface tension has very little to do with the physics of stone-skipping. Instead, the stones are a flying wing akin to a planing boat or Frisbee, generating lift from a body angled upwards relative to a high horizontal velocity.The same physical laws apply to stones traveling in air or in water, but the effect is only comparable to gravity when immersed in water, because of the latter fluid's higher density. The result is a characteristic bouncing or skipping motion, in which a series of extremely brief collisions with the water superficially appear to support the stone.During each collision, the stone's horizontal velocity is approximately constant and its vertical motion can be approximated as a distorted pendulum. The stone is only partially immersed, and the lift applied at the back torques the stone towards tumbling. That torque is stabilized by the gyroscope effect: the stone-skipper imparts a perpendicular initial angular momentum much larger than the collisional impulse, so that the latter induces only a small precession in the axis of rotation.Stones improperly oriented at the moment of collision will not rebound: the largest observed angle of attack preceding a rebound occurred at an angle of approximately 45°. Conversely, a stone making angle 20° with the water's surface may rebound even at relatively low velocities, as well as minimizing the time and energy spent in the following collision.In principle, a stone can skip arbitrarily-long distances, given a sufficiently high initial speed and rotation. Each collision saps an approximately constant kinetic energy from the stone (a dynamical equation equivalent to Coulomb friction), as well as imparting an approximately constant angular impulse. Experiments suggest that initial angular momentum's stabilizing effect limits most stones: even "long-lived" throws still have high translational velocities when they finally sink.
Names:
English: "skipping stones" or "skipping rocks" (North America); "lobsta cutting" (Cape Cod, North America); "stone skimming" or "ducks and drakes" (Britain); Skliffing or "skiting" (Scotland) and "stone skiffing" (Ireland) Bengali: "frog jumps" (Bengbaji); "kingfisher" (Machhranga) Bulgarian: "frogs" (жабки) Cantonese: "skipping (little) stones" (片石(仔)) [pin3 sek6 (zai2)] Catalan: "making step-stone bridges" (fer passeres); "making furrows" (fer rigalets); "skipping stones" (llençar passanelles) Czech: "to make/throw froggies" (dělat (házet) žabky/žabičky – countrywide and generally intelligible); "to make ducks/drakes/ducklings" (dělat kačky/kačeny/kačery/kačenky/káčata/káčírky - in East Bohemia and parts of Moravia); "little fishes" (rybičky/rybky); "saucers" (mističky); "plates/dishes" (talíře); "wagtails" (podlisky/podlíšky/lyšky); "divers" (potápky); "pot-lids" (pokličky/pukličky); "flaps" (plisky/plesky); "plops" (žbluňky); "darts" (šipky); "bubbles" (bubliny); "Jews" (židy); "figures" (páni/panáky); "gammers"/"wagtails" (babky); "dolls"/"girls"/"dragonflies" (panenky); "to ferry Virgin Mary" (převážet panenku Mariu) Danish: "slipping" (smut or at smutte); "to make slips" (at slå smut) Dutch: "ketsen" (bouncing) Estonian: "throwing a burbot" (lutsu viskama) Finnish: "throwing bread/a sandwich" (heittää leipiä/voileipiä) French: "making ricochets" (faire des ricochets) German: "stone skipping" (Steinehüpfen); colloquially i.a. "flitting" (flitschen, old synonym of schwirren, "whirring"), its diminutive flitscheln, and "bouncing" (ditschen, a variant of titschen); older synonyms rarely used are i.a. "leading the bride" (die Braut führen), "throwing frogs" (Frösche werfen), "shooting/throwing maids/virgins" (Jungfern schießen/werfen), "skiffing" (schiffeln, schippern), "springing" (schnellern, from schnellen, "springing" or "darting"), and "pebbling" (steineln) Greek: "little frogs" (βατραχάκια) Hungarian: "making it to waddle", lit. "making it walk like a duck" (kacsáztatás) Italian: rimbalzello Japanese: "cutting water" (「水切り」[mizu kiri]) Korean: mulsujebi (물수제비), meaning water (Korean: 물; RR: mul) and Korean soup sujebi.
Names:
Latvian: "throwing (stone) froggies" (mest (akmens) vardītes) Lithuanian: "making frogs" (daryti varlytes) Macedonian: "frogs" (жабчиња) Mandarin: da shui piao (打水漂) Marathi: bhakrya kadhne Mongolian: "making the rabbit leap" (tuulai kharailgakh); "making the dog lick" (nokhoi doloolgokh) Nigerian: "the way a dragonfly skips across the water" (lami lami) Norwegian: "fish bounce" (fiskesprett) Polish: "letting the ducks out" (puszczanie kaczek) Portuguese "water shearing" ("capar a água"); "making tiny hats" ("fazer chapeletas") Russian: "pancakes" (блинчики [Blinchiki]); "frogs" (лягушки [Lyagushki]) Serbo-Croatian: "(to throw) little frogs" ([bacati] žabice) Spanish: "making white-caps" (hacer cabrillas); "making little frogs" (hacer ranitas); making ducklings (hacer patitos) Swedish: "throwing a sandwich" (kasta smörgås or kasta macka) Telugu: "frog jumps" (kappa gantulu) Turkish: "skimming stone" (taş sektirme) Ukrainian: "letting the frogs out" (zapuskaty zhabky) Farsi/Persian: "Syrian bashing" (سوری زدن) Vietnamese: "ricochet" (ném thia lia); "tossing stone" (liếc đá, lia đá)
In popular culture:
The lead character of the 2001 film Amélie skips stones along the Canal Saint-Martin in Paris as a plot point, and picks up good skipping stones when she spots them. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Sigma 24mm f/1.8 EX DG lens**
Sigma 24mm f/1.8 EX DG lens:
The Sigma 24mm f/1.8 EX DG is wide-angle lens which features a fast f/1.8 maximum aperture for use in low-light situations, and macro focusing capability to a reproduction ratio of 1:2.7. It uses aspherical lens elements. Though intended for 35mm film and full-frame digital SLRs, this lens is available for several makes of APS-C digital SLR cameras, where the angle of view is similar to a moderate wide-angle lens (in the 35mm-40mm range, depending on the size of the D-SLR sensor).
Sigma 24mm f/1.8 EX DG lens:
This lens is capable of macro photography, with minimum focusing down to 18 cm/7.1" (reproduction ratio 1:2.7). It incorporates a floating focus system in order to minimize distortion, spherical aberration and astigmatism, and provides high performance at all shooting distances. The high reproduction ratio and wide angle of view allow capturing high quality images not only of a subject but also the surrounding scenery.
Sigma 24mm f/1.8 EX DG lens:
The Lens was introduced in 2001. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Fucosyltransferase 4**
Fucosyltransferase 4:
Fucosyltransferase 4 is a protein that in humans is encoded by the FUT4 gene.
Function:
The product of this gene transfers fucose to N-acetyllactosamine polysaccharides to generate fucosylated carbohydrate structures. It catalyzes the synthesis of the non-sialylated antigen, Lewis x (CD15). [provided by RefSeq, Jan 2009]. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Helmsman**
Helmsman:
A helmsman or helm (sometimes driver) is a person who steers a ship, sailboat, submarine, other type of maritime vessel, or spacecraft. The rank and seniority of the helmsman may vary: on small vessels such as fishing vessels and yachts, the functions of the helmsman are combined with that of the skipper; on larger vessels, there is a separate officer of the watch who is responsible for the safe navigation of the ship and gives orders to the helmsman, who physically steers the ship in accordance with those orders.
Helmsman:
In the merchant navy, the person at the helm is usually an able seaman, particularly during ship arrivals, departures, and while maneuvering in restricted waters or other conditions requiring precise steering. An ordinary seaman is commonly restricted to steering in open waters. Moreover, military ships may have a seaman or quartermaster at the helm.
Helmsman:
A professional helmsman maintains a steady course, properly executes all rudder orders, and communicates to the officer on the bridge using navigational terms relating to ship's heading and steering. A helmsman relies upon visual references, a magnetic and gyrocompass, and a rudder angle indicator to steer a steady course. The mate or other officer on the bridge directs the helmsman aboard merchant or navy ships.
Helmsman:
Clear and exact communication between the helmsman and officer on the bridge is essential to safe navigation and ship handling. Consequently, a set of standard steering commands, responses by the helmsman, and acknowledgment by the conning officer are widely recognized in the maritime industry. The helmsman repeats any verbal commands to demonstrate that the command is heard and understood. The International Convention on Standards of Training, Certification and Watchkeeping for Seafarers (STCW) requires that a helmsman be able to understand and respond to helm orders in English.The proliferation of autopilot systems and the increased computerization of operations on a ship's bridge lessen the need for helmsmen standing watch in open waters.
Helm commands:
Helm orders or commands fall into two categories: rudder commands and heading commands. A rudder command dictates changing the angle of the rudder, which is a single-event action, whereas steering a heading is a comparatively long event and will require ongoing or continuous rudder adjustments.
Helm commands:
The following are helm orders used in the United States Navy and United States Coast Guard:Rudder Midships (Bring rudder angle to 0 degrees) Meet Her (Counter steer to stop the movement or swing of the ship's bow) Hard rudder (Used infrequently, such as emergencies, when maximum rudder is required) Left or right standard rudder (~20 degrees. Varies per ship) Shift your rudder (Steer the same number of degrees but opposite rudder angle)Heading Steady as she goes (Steer as needed to continue current heading) Steady on a course (Steer as needed to bring ship on desired course)
Acquired skills:
Steering a ship effectively requires skills gained through training and experience. An expert helmsman has a keen sense of how a particular ship will respond to the helm or how different sea conditions impact steering. For instance, experience teaches a helmsman the ability to correct the rudder in advance of a ship substantially falling off course. This requires the capacity to anticipate the delay between when the helm is applied and when the ship responds to the rudder. Similarly, a skilled helmsman will avoid overcompensating for a ship's movement caused by local conditions, such as wind, swells, currents, or rough seas.
Acquired skills:
Ship simulators Computer-based ship simulators provide a training environment for learning skills to steer a ship. Training can be programmed to replicate a variety of ship sizes and environmental conditions. Scenarios depicted in 3-D graphics range from making course corrections in open waters to maneuvering in port, rivers, or other shallow waters. Cost compared to a real vessel is low. Mariners learn responses to dangerous situations, such as steering failure, in the safety of a virtual environment.
Acquired skills:
Land-based ship simulators may feature a full-scale replica of a steering stand with a ship's wheel. Such simulators incorporate magnetic and gyro compasses (or repeaters) for steering. Moreover, a rudder angle indicator that responds appropriately to the helm is part of the configuration.
Acquired skills:
However technology also allows for a multitude of smaller workstations in a classroom setting. Administrators network student workstations so that the instructor can launch individual scenarios at each station. Computer models are used to accurately simulate conditions such as wind, seas, and currents. Moreover, shallow-water effects or other hydrodynamic forces, such as ships passing close to each other, can also be depicted. A computer application records training sessions, complete with voice commands issued by the instructor which are received by the students via a headset.
Acquired skills:
On the job training On-the-job training at sea is critical to a helmsman developing ability to "sense" or anticipate how a ship will respond in different conditions. The experienced helmsman uses measured responses to sea conditions, even when encountering heavy weather that may cause a ship to pitch and roll as it pounds its way through oncoming waves. Subsequently, the helmsman learns to relax and take into account the vessel's natural rhythm in order to avoid oversteering whatever the maritime environment. Consequently, more accurate steering is attained with less rudder. Applying the minimal rudder required to steer a course reduces drag of the ship, thereby favorably impacting the ship's speed and operating costs.
Acquired skills:
One of the helmsman's most important duties is steering a ship in a harbor or seaport when reduced speeds slow a ship's response to the rudder. For it is during ship arrivals and departures, when most ship collisions or groundings occur. Clear communication, then, between the officer of the bridge and the helmsman is essential for safe operations. The officer or harbor pilot relies upon the helmsman to flawlessly execute steering commands to avoid a variety of hazards, including man-made obstacles, land formations, grounding in shallow waters, and the threat of collision with other vessels. In addition, powerful sea tides and river currents encountered in seaports heighten navigation dangers, as a ship's ability to stop is severely limited.
Relieving the helm:
Helmsmen of merchant and military ships that are underway stand watch at the helm for a set period of time before being relieved by another watchstander. The person being relieved will complete any course change or other critical maneuver that is in progress before handing over the helm.
Relieving the helm:
Merchant vessels The helmsman handing over the helm will inform the relief helmsman of any rudder commands in place and pertinent conditions. "Steering 180. We have oncoming traffic two points on the starboard" for example. In addition, the current helmsman should inform the relief if there are any peculiarities affecting steerage. Similarly, the helmsman will also point out if he or she is steering on a landmark, range, or navigational light. The relief helmsman is obligated to repeat the course being steered or other rudder command in order to demonstrate an understanding of the situation at the helm.
Relieving the helm:
On merchant ships, it is taught at the various maritime academies that the proper way to relieve the helm is for the helmsman being relieved to call out loudly the ship's course per gyro, course per standard magnetic compass, steering mode, rudder angle, and the pump the vessel is steering off of. The relief helmsman will then take the helm and repeat all the information to ensure that he/she knows what to steer while on watch. An example of this would be: Helmsman: "Helm is being relieved... steering two-four-eight per gyro, checking two-four-five per standard. Helm is in hand, rudder amidships, steering off the port pump." Relief: "Helm has been relieved... steering two-four-eight per gyro, checking two-four-five per standard. Helm is in hand, rudder amidships, steering off the port pump." The officer on watch will usually reply with "very well." | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**PyAOP reagent**
PyAOP reagent:
PyAOP ((7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate) is a coupling reagent used in solid phase peptide synthesis. It is a derivative of the HOAt family of coupling reagents. It is preferred over HATU, because it does not side react at the N-terminus of the peptide. Compared to the HOBt derivates, PyAOP (and HOAt in general) are more reactive due to the additional nitrogen. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cotton tensor**
Cotton tensor:
In differential geometry, the Cotton tensor on a (pseudo)-Riemannian manifold of dimension n is a third-order tensor concomitant of the metric. The vanishing of the Cotton tensor for n = 3 is necessary and sufficient condition for the manifold to be conformally flat. By contrast, in dimensions n ≥ 4, the vanishing of the Cotton tensor is necessary but not sufficient for the metric to be conformally flat; instead, the corresponding necessary and sufficient condition in these higher dimensions is the vanishing of the Weyl tensor, while the Cotton tensor just becomes a constant times the divergence of the Weyl tensor. For n < 3 the Cotton tensor is identically zero. The concept is named after Émile Cotton.
Cotton tensor:
The proof of the classical result that for n = 3 the vanishing of the Cotton tensor is equivalent to the metric being conformally flat is given by Eisenhart using a standard integrability argument. This tensor density is uniquely characterized by its conformal properties coupled with the demand that it be differentiable for arbitrary metrics, as shown by (Aldersley 1979).
Cotton tensor:
Recently, the study of three-dimensional spaces is becoming of great interest, because the Cotton tensor restricts the relation between the Ricci tensor and the energy–momentum tensor of matter in the Einstein equations and plays an important role in the Hamiltonian formalism of general relativity.
Definition:
In coordinates, and denoting the Ricci tensor by Rij and the scalar curvature by R, the components of the Cotton tensor are Cijk=∇kRij−∇jRik+12(n−1)(∇jRgik−∇kRgij).
The Cotton tensor can be regarded as a vector valued 2-form, and for n = 3 one can use the Hodge star operator to convert this into a second order trace free tensor density Cij=∇k(Rli−14Rgli)ϵklj, sometimes called the Cotton–York tensor.
Properties:
Conformal rescaling Under conformal rescaling of the metric g~=e2ωg for some scalar function ω . We see that the Christoffel symbols transform as Γ~βγα=Γβγα+Sβγα where Sβγα is the tensor Sβγα=δγα∂βω+δβα∂γω−gβγ∂αω The Riemann curvature tensor transforms as R~λμαβ=Rλμαβ+∇αSβμλ−∇βSαμλ+SαρλSβμρ−SβρλSαμρ In n -dimensional manifolds, we obtain the Ricci tensor by contracting the transformed Riemann tensor to see it transform as R~βμ=Rβμ−gβμ∇α∂αω−(n−2)∇μ∂βω+(n−2)(∂μω∂βω−gβμ∂λω∂λω) Similarly the Ricci scalar transforms as R~=e−2ωR−2e−2ω(n−1)∇α∂αω−(n−2)(n−1)e−2ω∂λω∂λω Combining all these facts together permits us to conclude the Cotton-York tensor transforms as C~αβγ=Cαβγ+(n−2)∂λωWβγαλ or using coordinate independent language as grad ω⌟W, where the gradient is plugged into the symmetric part of the Weyl tensor W.
Properties:
Symmetries The Cotton tensor has the following symmetries: Cijk=−Cikj and therefore 0.
In addition the Bianchi formula for the Weyl tensor can be rewritten as δW=(3−n)C, where δ is the positive divergence in the first component of W. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Alkaloid**
Alkaloid:
Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar structure may also be termed alkaloids. In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen or sulfur. More rarely still, they may contain elements such as phosphorus, chlorine, and bromine.Alkaloids are produced by a large variety of organisms including bacteria, fungi, plants, and animals. They can be purified from crude extracts of these organisms by acid-base extraction, or solvent extractions followed by silica-gel column chromatography. Alkaloids have a wide range of pharmacological activities including antimalarial (e.g. quinine), antiasthma (e.g. ephedrine), anticancer (e.g. homoharringtonine), cholinomimetic (e.g. galantamine), vasodilatory (e.g. vincamine), antiarrhythmic (e.g. quinidine), analgesic (e.g. morphine), antibacterial (e.g. chelerythrine), and antihyperglycemic activities (e.g. piperine). Many have found use in traditional or modern medicine, or as starting points for drug discovery. Other alkaloids possess psychotropic (e.g. psilocin) and stimulant activities (e.g. cocaine, caffeine, nicotine, theobromine), and have been used in entheogenic rituals or as recreational drugs. Alkaloids can be toxic too (e.g. atropine, tubocurarine). Although alkaloids act on a diversity of metabolic systems in humans and other animals, they almost uniformly evoke a bitter taste.The boundary between alkaloids and other nitrogen-containing natural compounds is not clear-cut. Compounds like amino acid peptides, proteins, nucleotides, nucleic acid, amines, and antibiotics are usually not called alkaloids. Natural compounds containing nitrogen in the exocyclic position (mescaline, serotonin, dopamine, etc.) are usually classified as amines rather than as alkaloids. Some authors, however, consider alkaloids a special case of amines.
Naming:
The name "alkaloids" (German: Alkaloide) was introduced in 1819 by German chemist Carl Friedrich Wilhelm Meissner, and is derived from late Latin root alkali and the Greek-language suffix -οειδής -('like'). However, the term came into wide use only after the publication of a review article, by Oscar Jacobsen in the chemical dictionary of Albert Ladenburg in the 1880s.There is no unique method for naming alkaloids. Many individual names are formed by adding the suffix "ine" to the species or genus name. For example, atropine is isolated from the plant Atropa belladonna; strychnine is obtained from the seed of the Strychnine tree (Strychnos nux-vomica L.). Where several alkaloids are extracted from one plant their names are often distinguished by variations in the suffix: "idine", "anine", "aline", "inine" etc. There are also at least 86 alkaloids whose names contain the root "vin" because they are extracted from vinca plants such as Vinca rosea (Catharanthus roseus); these are called vinca alkaloids.
History:
Alkaloid-containing plants have been used by humans since ancient times for therapeutic and recreational purposes. For example, medicinal plants have been known in Mesopotamia from about 2000 BC. The Odyssey of Homer referred to a gift given to Helen by the Egyptian queen, a drug bringing oblivion. It is believed that the gift was an opium-containing drug. A Chinese book on houseplants written in 1st–3rd centuries BC mentioned a medical use of ephedra and opium poppies. Also, coca leaves have been used by Indigenous South Americans since ancient times.Extracts from plants containing toxic alkaloids, such as aconitine and tubocurarine, were used since antiquity for poisoning arrows.Studies of alkaloids began in the 19th century. In 1804, the German chemist Friedrich Sertürner isolated from opium a "soporific principle" (Latin: principium somniferum), which he called "morphium", referring to Morpheus, the Greek god of dreams; in German and some other Central-European languages, this is still the name of the drug. The term "morphine", used in English and French, was given by the French physicist Joseph Louis Gay-Lussac.
History:
A significant contribution to the chemistry of alkaloids in the early years of its development was made by the French researchers Pierre Joseph Pelletier and Joseph Bienaimé Caventou, who discovered quinine (1820) and strychnine (1818). Several other alkaloids were discovered around that time, including xanthine (1817), atropine (1819), caffeine (1820), coniine (1827), nicotine (1828), colchicine (1833), sparteine (1851), and cocaine (1860). The development of the chemistry of alkaloids was accelerated by the emergence of spectroscopic and chromatographic methods in the 20th century, so that by 2008 more than 12,000 alkaloids had been identified.The first complete synthesis of an alkaloid was achieved in 1886 by the German chemist Albert Ladenburg. He produced coniine by reacting 2-methylpyridine with acetaldehyde and reducing the resulting 2-propenyl pyridine with sodium.
Classifications:
Compared with most other classes of natural compounds, alkaloids are characterized by a great structural diversity. There is no uniform classification. Initially, when knowledge of chemical structures was lacking, botanical classification of the source plants was relied on. This classification is now considered obsolete.More recent classifications are based on similarity of the carbon skeleton (e.g., indole-, isoquinoline-, and pyridine-like) or biochemical precursor (ornithine, lysine, tyrosine, tryptophan, etc.). However, they require compromises in borderline cases; for example, nicotine contains a pyridine fragment from nicotinamide and a pyrrolidine part from ornithine and therefore can be assigned to both classes.Alkaloids are often divided into the following major groups: "True alkaloids" contain nitrogen in the heterocycle and originate from amino acids. Their characteristic examples are atropine, nicotine, and morphine. This group also includes some alkaloids that besides the nitrogen heterocycle contain terpene (e.g., evonine) or peptide fragments (e.g. ergotamine). The piperidine alkaloids coniine and coniceine may be regarded as true alkaloids (rather than pseudoalkaloids: see below) although they do not originate from amino acids.
Classifications:
"Protoalkaloids", which contain nitrogen (but not the nitrogen heterocycle) and also originate from amino acids. Examples include mescaline, adrenaline and ephedrine.
Polyamine alkaloids – derivatives of putrescine, spermidine, and spermine.
Peptide and cyclopeptide alkaloids.
Classifications:
Pseudoalkaloids – alkaloid-like compounds that do not originate from amino acids. This group includes terpene-like and steroid-like alkaloids, as well as purine-like alkaloids such as caffeine, theobromine, theacrine and theophylline. Some authors classify ephedrine and cathinone as pseudoalkaloids. Those originate from the amino acid phenylalanine, but acquire their nitrogen atom not from the amino acid but through transamination.Some alkaloids do not have the carbon skeleton characteristic of their group. So, galanthamine and homoaporphines do not contain isoquinoline fragment, but are, in general, attributed to isoquinoline alkaloids.Main classes of monomeric alkaloids are listed in the table below:
Properties:
Most alkaloids contain oxygen in their molecular structure; those compounds are usually colorless crystals at ambient conditions. Oxygen-free alkaloids, such as nicotine or coniine, are typically volatile, colorless, oily liquids. Some alkaloids are colored, like berberine (yellow) and sanguinarine (orange).Most alkaloids are weak bases, but some, such as theobromine and theophylline, are amphoteric. Many alkaloids dissolve poorly in water but readily dissolve in organic solvents, such as diethyl ether, chloroform or 1,2-dichloroethane. Caffeine, cocaine, codeine and nicotine are slightly soluble in water (with a solubility of ≥1g/L), whereas others, including morphine and yohimbine are very slightly water-soluble (0.1–1 g/L). Alkaloids and acids form salts of various strengths. These salts are usually freely soluble in water and ethanol and poorly soluble in most organic solvents. Exceptions include scopolamine hydrobromide, which is soluble in organic solvents, and the water-soluble quinine sulfate.Most alkaloids have a bitter taste or are poisonous when ingested. Alkaloid production in plants appeared to have evolved in response to feeding by herbivorous animals; however, some animals have evolved the ability to detoxify alkaloids. Some alkaloids can produce developmental defects in the offspring of animals that consume but cannot detoxify the alkaloids. One example is the alkaloid cyclopamine, produced in the leaves of corn lily. During the 1950s, up to 25% of lambs born by sheep that had grazed on corn lily had serious facial deformations. These ranged from deformed jaws to cyclopia (see picture). After decades of research, in the 1980s, the compound responsible for these deformities was identified as the alkaloid 11-deoxyjervine, later renamed to cyclopamine.
Distribution in nature:
Alkaloids are generated by various living organisms, especially by higher plants – about 10 to 25% of those contain alkaloids. Therefore, in the past the term "alkaloid" was associated with plants.The alkaloids content in plants is usually within a few percent and is inhomogeneous over the plant tissues. Depending on the type of plants, the maximum concentration is observed in the leaves (for example, black henbane), fruits or seeds (Strychnine tree), root (Rauvolfia serpentina) or bark (cinchona). Furthermore, different tissues of the same plants may contain different alkaloids.Beside plants, alkaloids are found in certain types of fungus, such as psilocybin in the fruiting bodies of the genus Psilocybe, and in animals, such as bufotenin in the skin of some toads and a number of insects, markedly ants. Many marine organisms also contain alkaloids. Some amines, such as adrenaline and serotonin, which play an important role in higher animals, are similar to alkaloids in their structure and biosynthesis and are sometimes called alkaloids.
Extraction:
Because of the structural diversity of alkaloids, there is no single method of their extraction from natural raw materials. Most methods exploit the property of most alkaloids to be soluble in organic solvents but not in water, and the opposite tendency of their salts.
Extraction:
Most plants contain several alkaloids. Their mixture is extracted first and then individual alkaloids are separated. Plants are thoroughly ground before extraction. Most alkaloids are present in the raw plants in the form of salts of organic acids. The extracted alkaloids may remain salts or change into bases. Base extraction is achieved by processing the raw material with alkaline solutions and extracting the alkaloid bases with organic solvents, such as 1,2-dichloroethane, chloroform, diethyl ether or benzene. Then, the impurities are dissolved by weak acids; this converts alkaloid bases into salts that are washed away with water. If necessary, an aqueous solution of alkaloid salts is again made alkaline and treated with an organic solvent. The process is repeated until the desired purity is achieved.
Extraction:
In the acidic extraction, the raw plant material is processed by a weak acidic solution (e.g., acetic acid in water, ethanol, or methanol). A base is then added to convert alkaloids to basic forms that are extracted with organic solvent (if the extraction was performed with alcohol, it is removed first, and the remainder is dissolved in water). The solution is purified as described above.Alkaloids are separated from their mixture using their different solubility in certain solvents and different reactivity with certain reagents or by distillation.A number of alkaloids are identified from insects, among which the fire ant venom alkaloids known as solenopsins have received greater attention from researchers. These insect alkaloids can be efficiently extracted by solvent immersion of live fire ants or by centrifugation of live ants followed by silica-gel chromatography purification. Tracking and dosing the extracted solenopsin ant alkaloids has been described as possible based on their absorbance peak around 232 nanometers.
Biosynthesis:
Biological precursors of most alkaloids are amino acids, such as ornithine, lysine, phenylalanine, tyrosine, tryptophan, histidine, aspartic acid, and anthranilic acid. Nicotinic acid can be synthesized from tryptophan or aspartic acid. Ways of alkaloid biosynthesis are too numerous and cannot be easily classified. However, there are a few typical reactions involved in the biosynthesis of various classes of alkaloids, including synthesis of Schiff bases and Mannich reaction.
Biosynthesis:
Synthesis of Schiff bases Schiff bases can be obtained by reacting amines with ketones or aldehydes. These reactions are a common method of producing C=N bonds.
Biosynthesis:
In the biosynthesis of alkaloids, such reactions may take place within a molecule, such as in the synthesis of piperidine: Mannich reaction An integral component of the Mannich reaction, in addition to an amine and a carbonyl compound, is a carbanion, which plays the role of the nucleophile in the nucleophilic addition to the ion formed by the reaction of the amine and the carbonyl.
Biosynthesis:
The Mannich reaction can proceed both intermolecularly and intramolecularly:
Dimer alkaloids:
In addition to the described above monomeric alkaloids, there are also dimeric, and even trimeric and tetrameric alkaloids formed upon condensation of two, three, and four monomeric alkaloids. Dimeric alkaloids are usually formed from monomers of the same type through the following mechanisms: Mannich reaction, resulting in, e.g., voacamine Michael reaction (villalstonine) Condensation of aldehydes with amines (toxiferine) Oxidative addition of phenols (dauricine, tubocurarine) Lactonization (carpaine).
Dimer alkaloids:
There are also dimeric alkaloids formed from two distinct monomers, such as the vinca alkaloids vinblastine and vincristine, which are formed from the coupling of catharanthine and vindoline. The newer semi-synthetic chemotherapeutic agent vinorelbine is used in the treatment of non-small-cell lung cancer. It is another derivative dimer of vindoline and catharanthine and is synthesised from anhydrovinblastine, starting either from leurosine or the monomers themselves.
Biological role:
Alkaloids are among the most important and best-known secondary metabolites, i.e. biogenic substances not directly involved in the normal growth, development, or reproduction of the organism. Instead, they generally mediate ecological interactions, which may produce a selective advantage for the organism by increasing its survivability or fecundity. In some cases their function, if any, remains unclear. An early hypothesis, that alkaloids are the final products of nitrogen metabolism in plants, as urea and uric acid are in mammals, was refuted by the finding that their concentration fluctuates rather than steadily increasing.Most of the known functions of alkaloids are related to protection. For example, aporphine alkaloid liriodenine produced by the tulip tree protects it from parasitic mushrooms. In addition, the presence of alkaloids in the plant prevents insects and chordate animals from eating it. However, some animals are adapted to alkaloids and even use them in their own metabolism. Such alkaloid-related substances as serotonin, dopamine and histamine are important neurotransmitters in animals. Alkaloids are also known to regulate plant growth. One example of an organism that uses alkaloids for protection is the Utetheisa ornatrix, more commonly known as the ornate moth. Pyrrolizidine alkaloids render these larvae and adult moths unpalatable to many of their natural enemies like coccinelid beetles, green lacewings, insectivorous hemiptera and insectivorous bats. Another example of alkaloids being utilized occurs in the poison hemlock moth (Agonopterix alstroemeriana). This moth feeds on its highly toxic and alkaloid-rich host plant poison hemlock (Conium maculatum) during its larval stage. A. alstroemeriana may benefit twofold from the toxicity of the naturally-occurring alkaloids, both through the unpalatability of the species to predators and through the ability of A. alstroemeriana to recognize Conium maculatum as the correct location for oviposition. A fire ant venom alkaloid known as solenopsin has been demonstrated to protect queens of invasive fire ants during the foundation of new nests, thus playing a central role in the spread of this pest ant species around the world.
Applications:
In medicine Medical use of alkaloid-containing plants has a long history, and, thus, when the first alkaloids were isolated in the 19th century, they immediately found application in clinical practice. Many alkaloids are still used in medicine, usually in the form of salts widely used including the following: Many synthetic and semisynthetic drugs are structural modifications of the alkaloids, which were designed to enhance or change the primary effect of the drug and reduce unwanted side-effects. For example, naloxone, an opioid receptor antagonist, is a derivative of thebaine that is present in opium.
Applications:
In agriculture Prior to the development of a wide range of relatively low-toxic synthetic pesticides, some alkaloids, such as salts of nicotine and anabasine, were used as insecticides. Their use was limited by their high toxicity to humans.
Applications:
Use as psychoactive drugs Preparations of plants containing alkaloids and their extracts, and later pure alkaloids, have long been used as psychoactive substances. Cocaine, caffeine, and cathinone are stimulants of the central nervous system. Mescaline and many indole alkaloids (such as psilocybin, dimethyltryptamine and ibogaine) have hallucinogenic effect. Morphine and codeine are strong narcotic pain killers.There are alkaloids that do not have strong psychoactive effect themselves, but are precursors for semi-synthetic psychoactive drugs. For example, ephedrine and pseudoephedrine are used to produce methcathinone and methamphetamine. Thebaine is used in the synthesis of many painkillers such as oxycodone.
General and cited references:
Aniszewski, Tadeusz (2007). Alkaloids: secrets of life. Amsterdam: Elsevier. ISBN 978-0-444-52736-3.
Begley, Tadhg P. (2009). Encyclopedia of Chemical Biology. pp. 1569–1570. doi:10.1002/cbic.200900262. ISBN 978-0-471-75477-0. {{cite book}}: |journal= ignored (help) Brossi, Arnold (1989). The Alkaloids: Chemistry and Pharmacology. Academic Press.
Dewick, Paul M. (2002). Medicinal Natural Products: A Biosynthetic Approach (Second ed.). Wiley. ISBN 978-0-471-49640-3.
Fattorusso, E.; Taglialatela-Scafati, O. (2008). Modern Alkaloids: Structure, Isolation, Synthesis and Biology. Wiley-VCH. ISBN 978-3-527-31521-5.
Grinkevich NI; Safronich LN, eds. (1983). The chemical analysis of medicinal plants (in Russian). Moscow: Vysshaya Shkola.
Hesse, Manfred (2002). Alkaloids: Nature's Curse or Blessing?. Wiley-VCH. ISBN 978-3-906390-24-6.
Knunyants, IL (1988). Chemical Encyclopedia. Soviet Encyclopedia.
Orekhov, AP (1955). Chemistry alkaloids (Acad. 2nd ed.). Moscow.{{cite book}}: CS1 maint: location missing publisher (link) Plemenkov, VV (2001). Introduction to the Chemistry of Natural Compounds. Kazan.{{cite book}}: CS1 maint: location missing publisher (link) Saxton, J. E. (1971). The Alkaloids: A Specialist Periodical Report. London: The Chemical Society.
Veselovskaya, N. B.; Kovalenko, A. E. (2000). Drugs. Moscow: Triada-X.
Wink, M (2009). "Mode of action and toxicology of plant toxins and poisonous plants". Mitt. Julius Kühn-Inst. 421: 93–112x. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Criticism of the theory of relativity**
Criticism of the theory of relativity:
Criticism of the theory of relativity of Albert Einstein was mainly expressed in the early years after its publication in the early twentieth century, on scientific, pseudoscientific, philosophical, or ideological bases. Though some of these criticisms had the support of reputable scientists, Einstein's theory of relativity is now accepted by the scientific community.Reasons for criticism of the theory of relativity have included alternative theories, rejection of the abstract-mathematical method, and alleged errors of the theory. According to some authors, antisemitic objections to Einstein's Jewish heritage also occasionally played a role in these objections. There are still some critics of relativity today, but their opinions are not shared by the majority in the scientific community.
Special relativity:
Relativity principle versus electromagnetic worldview Around the end of the 19th century, the view was widespread that all forces in nature are of electromagnetic origin (the "electromagnetic worldview"), especially in the works of Joseph Larmor (1897) and Wilhelm Wien (1900). This was apparently confirmed by the experiments of Walter Kaufmann (1901–1903), who measured an increase of the mass of a body with velocity which was consistent with the hypothesis that the mass was generated by its electromagnetic field. Max Abraham (1902) subsequently sketched a theoretical explanation of Kaufmann's result in which the electron was considered as rigid and spherical. However, it was found that this model was incompatible with the results of many experiments (including the Michelson–Morley experiment, the Experiments of Rayleigh and Brace, and the Trouton–Noble experiment), according to which no motion of an observer with respect to the luminiferous aether ("aether drift") had been observed despite numerous attempts to do so. Henri Poincaré (1902) conjectured that this failure arose from a general law of nature, which he called "the principle of relativity". Hendrik Antoon Lorentz (1904) created a detailed theory of electrodynamics (Lorentz ether theory) that was premised on the existence of an immobile aether and employed a set of space and time coordinate transformations that Poincaré called the Lorentz transformations, including the effects of length contraction and local time. However, Lorentz's theory only partially satisfied the relativity principle, because his transformation formulas for velocity and charge density were incorrect. This was corrected by Poincaré (1905) who obtained full Lorentz covariance of the electrodynamic equations.Criticizing Lorentz's 1904 theory, Abraham (1904) held that the Lorentz contraction of electrons requires a non-electromagnetic force to ensure the electron's stability. This was unacceptable to him as a proponent of the electromagnetic worldview. He continued that as long as a consistent explanation is missing as to how those forces and potentials act together on the electron, Lorentz's system of hypotheses is incomplete and doesn't satisfy the relativity principle. Poincaré (1905) removed this objection by showing that the non-electromagnetic potential ("Poincaré stress") holding the electron together can be formulated in a Lorentz covariant way, and showed that in principle it is possible to create a Lorentz covariant model for gravitation which he considered non-electromagnetic in nature as well. Thus the consistency of Lorentz's theory was proven, but the electromagnetic worldview had to be given up. Eventually, Albert Einstein published in September 1905 what is now called special relativity, which was based on a radical new application of the relativity principle in connection with the constancy of the speed of light. In special relativity, the space and time coordinates depend on the inertial observer's frame of reference, and the luminiferous aether plays no role in the physics. Although this theory was founded on a very different kinematical model, it was experimentally indistinguishable from the aether theory of Lorentz and Poincaré, since both theories satisfy the relativity principle of Poincaré and Einstein, and both employ the Lorentz transformations. After Minkowski's introduction in 1908 of the geometric spacetime model for Einstein's version of relativity, most physicists eventually decided in favor of the Einstein-Minkowski version of relativity with its radical new views of space and time, in which there was no useful role for the aether.
Special relativity:
Claimed experimental refutations Kaufmann–Bucherer–Neumann experiments: To conclusively decide between the theories of Abraham and Lorentz, Kaufmann repeated his experiments in 1905 with improved accuracy. However, in the meantime the theoretical situation had changed. Alfred Bucherer and Paul Langevin (1904) developed another model, in which the electron is contracted in the line of motion, and dilated in the transverse direction, so that the volume remains constant. While Kaufmann was still evaluating his experiments, Einstein published his theory of special relativity. Eventually, Kaufmann published his results in December 1905 and argued that they are in agreement with Abraham's theory and require rejection of the "basic assumption of Lorentz and Einstein" (the relativity principle). Lorentz reacted with the phrase "I am at the end of my Latin", while Einstein did not mention those experiments before 1908. Yet, others started to criticize the experiments. Max Planck (1906) alluded to inconsistencies in the theoretical interpretation of the data, and Adolf Bestelmeyer (1906) introduced new techniques, which (especially in the area of low velocities) gave different results and which cast doubts on Kaufmann's methods. Therefore, Bucherer (1908) conducted new experiments and arrived at the conclusion that they confirm the mass formula of relativity and thus the "relativity principle of Lorentz and Einstein". Yet Bucherer's experiments were criticized by Bestelmeyer leading to a sharp dispute between the two experimentalists. On the other hand, additional experiments of Hupka (1910), Neumann (1914) and others seemed to confirm Bucherer's result. The doubts lasted until 1940, when in similar experiments Abraham's theory was conclusively disproved. (It must be remarked that besides those experiments, the relativistic mass formula had already been confirmed by 1917 in the course of investigations on the theory of spectra. In modern particle accelerators, the relativistic mass formula is routinely confirmed.)In 1902–1906, Dayton Miller repeated the Michelson–Morley experiment together with Edward W. Morley. They confirmed the null result of the initial experiment. However, in 1921–1926, Miller conducted new experiments which apparently gave positive results. Those experiments initially attracted some attention in the media and in the scientific community but have been considered refuted for the following reasons: Einstein, Max Born, and Robert S. Shankland pointed out that Miller had not appropriately considered the influence of temperature. A modern analysis by Roberts shows that Miller's experiment gives a null result, when the technical shortcomings of the apparatus and the error bars are properly considered. Additionally, Miller's result is in disagreement with all other experiments, which were conducted before and after. For example, Georg Joos (1930) used an apparatus of similar dimensions to Miller's, but he obtained null results. In recent experiments of Michelson–Morley type where the coherence length is increased considerably by using lasers and masers the results are still negative.
Special relativity:
In the 2011 Faster-than-light neutrino anomaly, the OPERA collaboration published results which appeared to show that the speed of neutrinos is slightly faster than the speed of light. However, sources of errors were found and confirmed in 2012 by the OPERA collaboration, which fully explained the initial results. In their final publication, a neutrino speed consistent with the speed of light was stated. Also subsequent experiments found agreement with the speed of light, see measurements of neutrino speed.
Special relativity:
Acceleration in special relativity It was also claimed that special relativity cannot handle acceleration, which would lead to contradictions in some situations. However, this assessment is not correct, since acceleration actually can be described in the framework of special relativity (see Acceleration (special relativity), Proper reference frame (flat spacetime), Hyperbolic motion, Rindler coordinates, Born coordinates). Paradoxes relying on insufficient understanding of these facts were discovered in the early years of relativity. For example, Max Born (1909) tried to combine the concept of rigid bodies with special relativity. That this model was insufficient was shown by Paul Ehrenfest (1909), who demonstrated that a rotating rigid body would, according to Born's definition, undergo a contraction of the circumference without contraction of the radius, which is impossible (Ehrenfest paradox). Max von Laue (1911) showed that rigid bodies cannot exist in special relativity, since the propagation of signals cannot exceed the speed of light, so an accelerating and rotating body will undergo deformations.Paul Langevin and von Laue showed that the twin paradox can be completely resolved by consideration of acceleration in special relativity. If two twins move away from each other, and one of them is accelerating and coming back to the other, then the accelerated twin is younger than the other one, since he was located in at least two inertial frames of reference, and therefore his assessment of which events are simultaneous changed during the acceleration. For the other twin nothing changes since he remained in a single frame.Another example is the Sagnac effect. Two signals were sent in opposite directions around a rotating platform. After their arrival a displacement of the interference fringes occurs. Sagnac himself believed that he had proved the existence of the aether. However, special relativity can easily explain this effect. When viewed from an inertial frame of reference, it is a simple consequence of the independence of the speed of light from the speed of the source, since the receiver runs away from one beam, while it approaches the other beam. When viewed from a rotating frame, the assessment of simultaneity changes during the rotation, and consequently the speed of light is not constant in accelerated frames.As was shown by Einstein, the only form of accelerated motion that cannot be non-locally described is the one due to gravitation. Einstein was also unsatisfied with the fact that inertial frames are preferred over accelerated frames. Thus over the course of several years (1908–1915), Einstein developed general relativity. This theory includes the replacement of Euclidean geometry by non-Euclidean geometry, and the resultant curvature of the path of light led Einstein (1912) to the conclusion that (like in extended accelerated frames) the speed of light is not constant in extended gravitational fields. Therefore, Abraham (1912) argued that Einstein had given special relativity a coup de grâce. Einstein responded that within its area of application (in areas where gravitational influences can be neglected) special relativity is still applicable with high precision, so one cannot speak of a coup de grâce at all.
Special relativity:
Superluminal speeds In special relativity, the transfer of signals at superluminal speeds is impossible, since this would violate the Poincaré-Einstein synchronization, and the causality principle. Following an old argument by Pierre-Simon Laplace, Poincaré (1904) alluded to the fact that Newton's law of universal gravitation is founded on an infinitely great speed of gravity. So the clock-synchronization by light signals could in principle be replaced by a clock-synchronization by instantaneous gravitational signals. In 1905, Poincaré himself solved this problem by showing that in a relativistic theory of gravity the speed of gravity is equal to the speed of light. Although much more complicated, this is also the case in Einstein's theory of general relativity.Another apparent contradiction lies in the fact that the group velocity in anomalously dispersive media is higher than the speed of light. This was investigated by Arnold Sommerfeld (1907, 1914) and Léon Brillouin (1914). They came to the conclusion that in such cases the signal velocity is not equal to the group velocity, but to the front velocity which is never faster than the speed of light. Similarly, it is also argued that the apparent superluminal effects discovered by Günter Nimtz can be explained by a thorough consideration of the velocities involved.Also quantum entanglement (denoted by Einstein as "spooky action at a distance"), according to which the quantum state of one entangled particle cannot be fully described without describing the other particle, does not imply superluminal transmission of information (see quantum teleportation), and it is therefore in conformity with special relativity.
Special relativity:
Paradoxes Insufficient knowledge of the basics of special relativity, especially the application of the Lorentz transformation in connection with length contraction and time dilation, led and still leads to the construction of various apparent paradoxes. Both the twin paradox and the Ehrenfest paradox and their explanation were already mentioned above. Besides the twin paradox, also the reciprocity of time dilation (i.e. every inertially moving observer considers the clock of the other one as being dilated) was heavily criticized by Herbert Dingle and others. For example, Dingle wrote a series of letters to Nature at the end of the 1950s. However, the self-consistency of the reciprocity of time dilation had already been demonstrated long before in an illustrative way by Lorentz (in his lectures from 1910, published 1931) and many others—they alluded to the fact that it is only necessary to carefully consider the relevant measurement rules and the relativity of simultaneity. Other known paradoxes are the Ladder paradox and Bell's spaceship paradox, which also can simply be solved by consideration of the relativity of simultaneity.
Special relativity:
Aether and absolute space Many physicists (like Hendrik Lorentz, Oliver Lodge, Albert Abraham Michelson, Edmund Taylor Whittaker, Harry Bateman, Ebenezer Cunningham, Charles Émile Picard, Paul Painlevé) were uncomfortable with the rejection of the aether, and preferred to interpret the Lorentz transformation based on the existence of a preferred frame of reference, as in the aether-based theories of Lorentz, Larmor, and Poincaré. However, the idea of an aether hidden from any observation was not supported by the mainstream scientific community, therefore the aether theory of Lorentz and Poincaré was superseded by Einstein's special relativity which was subsequently formulated in the framework of four-dimensional spacetime by Minkowski.Others such as Herbert E. Ives argued that it might be possible to experimentally determine the motion of such an aether, but it was never found despite numerous experimental tests of Lorentz invariance (see tests of special relativity).
Special relativity:
Also attempts to introduce some sort of relativistic aether (consistent with relativity) into modern physics such as by Einstein on the basis of general relativity (1920), or by Paul Dirac in relation to quantum mechanics (1951), were not supported by the scientific community (see Luminiferous aether#End of aether?).In his Nobel lecture, George F. Smoot (2006) described his own experiments on the Cosmic microwave background radiation anisotropy as "New Aether drift experiments". Smoot explained that "one problem to overcome was the strong prejudice of good scientists who learned the lesson of the Michelson and Morley experiment and Special Relativity that there were no preferred frames of reference." He continued that "there was an education job to convince them that this did not violate Special Relativity but did find a frame in which the expansion of the universe looked particularly simple." Alternative theories The theory of complete aether drag, as proposed by George Gabriel Stokes (1844), was used by some critics as Ludwig Silberstein (1920) or Philipp Lenard (1920) as a counter-model of relativity. In this theory, the aether was completely dragged within and in the vicinity of matter, and it was believed that various phenomena, such as the absence of aether drift, could be explained in an "illustrative" way by this model. However, such theories are subject to great difficulties. Especially the aberration of light contradicted the theory, and all auxiliary hypotheses, which were invented to rescue it, are self-contradictory, extremely implausible, or in contradiction to other experiments like the Michelson–Gale–Pearson experiment. In summary, a sound mathematical and physical model of complete aether drag was never invented, consequently this theory was no serious alternative to relativity.Another alternative was the so-called emission theory of light. As in special relativity the aether concept is discarded, yet the main difference from relativity lies in the fact that the velocity of the light source is added to that of light in accordance with the Galilean transformation. As the hypothesis of complete aether drag, it can explain the negative outcome of all aether drift experiments. Yet, there are various experiments that contradict this theory. For example, the Sagnac effect is based on the independence of light speed from the source velocity, and the image of Double stars should be scrambled according to this model—which was not observed. Also in modern experiments in particle accelerators no such velocity dependence could be observed. These results are further confirmed by the De Sitter double star experiment (1913), conclusively repeated in the X-ray spectrum by K. Brecher in 1977; and the terrestrial experiment by Alväger, et al. (1963);, which all show that the speed of light is independent of the motion of the source within the limits of experimental accuracy.
Special relativity:
Principle of the constancy of the speed of light Some consider the principle of the constancy of the velocity of light insufficiently substantiated. However, as already shown by Robert Daniel Carmichael (1910) and others, the constancy of the speed of light can be interpreted as a natural consequence of two experimentally demonstrated facts: The velocity of light is independent of the velocity of the source, as demonstrated by De Sitter double star experiment, Sagnac effect, and many others (see emission theory).
Special relativity:
The velocity of light is independent of the direction of velocity of the observer, as demonstrated by Michelson–Morley experiment, Kennedy–Thorndike experiment, and many others (see luminiferous aether).Note that measurements regarding the speed of light are actually measurements of the two-way speed of light, since the one-way speed of light depends on which convention is chosen to synchronize the clocks.
General relativity:
General covariance Einstein emphasized the importance of general covariance for the development of general relativity, and took the position that the general covariance of his 1915 theory of gravity ensured implementation of a generalized relativity principle. This view was challenged by Erich Kretschmann (1917), who argued that every theory of space and time (even including Newtonian dynamics) can be formulated in a covariant way, if additional parameters are included, and thus general covariance of a theory would in itself be insufficient to implement a generalized relativity principle. Although Einstein (1918) agreed with that argument, he also countered that Newtonian mechanics in general covariant form would be too complicated for practical uses. Although it is now understood that Einstein's response to Kretschmann was mistaken (subsequent papers showed that such a theory would still be usable), another argument can be made in favor of general covariance: it is a natural way to express the equivalence principle, i.e., the equivalence in the description of a free-falling observer and an observer at rest, and thus it is more convenient to use general covariance together with general relativity, rather than with Newtonian mechanics. Connected with this, also the question of absolute motion was dealt with. Einstein argued that the general covariance of his theory of gravity supports Mach's principle, which would eliminate any "absolute motion" within general relativity. However, as pointed out by Willem de Sitter in 1916, Mach's principle is not completely fulfilled in general relativity because there exist matter-free solutions of the field equations. This means that the "inertio-gravitational field", which describes both gravity and inertia, can exist in the absence of gravitating matter. However, as pointed out by Einstein, there is one fundamental difference between this concept and absolute space of Newton: the inertio-gravitational field of general relativity is determined by matter, thus it is not absolute.
General relativity:
Bad Nauheim Debate In the "Bad Nauheim Debate" (1920) between Einstein and (among others) Philipp Lenard, the latter stated the following objections: He criticized the lack of "illustrativeness" of Einstein's version of relativity, a condition that he suggested could only be met by an aether theory. Einstein responded that for physicists the content of "illustrativeness" or "common sense" had changed in time, so it could no longer be used as a criterion for the validity of a physical theory. Lenard also argued that with his relativistic theory of gravity Einstein had tacitly reintroduced the aether under the name "space". While this charge was rejected (among others) by Hermann Weyl, in an inaugural address given at the University of Leiden in 1920, shortly after the Bad Nauheim debates, Einstein himself acknowledged that according to his general theory of relativity, so-called "empty space" possesses physical properties that influence matter and vice versa. Lenard also argued that Einstein's general theory of relativity admits the existence of superluminal velocities, in contradiction to the principles of special relativity; for example, in a rotating coordinate system in which the Earth is at rest, the distant points of the whole universe are rotating around Earth with superluminal velocities. However, as Weyl pointed out, it is incorrect to handle a rotating extended system as a rigid body (neither in special nor in general relativity)—so the signal velocity of an object never exceeds the speed of light. Another criticism that was raised by both Lenard and Gustav Mie concerned the existence of "fictitious" gravitational fields in accelerating frames, which according to Einstein's Equivalence Principle are no less physically real than those produced by material sources. Lenard and Mie argued that physical forces can only be produced by real material sources, while the gravitational field that Einstein supposed to exist in an accelerating frame of reference has no concrete physical meaning. Einstein responded that, based on Mach's principle, one can think of these gravitational fields as induced by the distant masses. In this respect the criticism of Lenard and Mie has been vindicated, since according to the modern consensus, in agreement with Einstein's own mature views, Mach's principle as originally conceived by Einstein is not actually supported by general relativity, as already mentioned above.
General relativity:
Silberstein–Einstein controversy Ludwik Silberstein, who initially was a supporter of the special theory, objected at different occasions against general relativity. In 1920 he argued that the deflection of light by the sun, as observed by Arthur Eddington et al. (1919), is not necessarily a confirmation of general relativity, but may also be explained by the Stokes-Planck theory of complete aether drag. However, such models are in contradiction with the aberration of light and other experiments (see "Alternative theories"). In 1935, Silberstein claimed to have found a contradiction in the Two-body problem in general relativity. The claim was refuted by Einstein and Rosen (1935).
Philosophical criticism:
The consequences of relativity, such as the change of ordinary concepts of space and time, as well as the introduction of non-Euclidean geometry in general relativity, were criticized by some philosophers of different philosophical schools. Many philosophical critics had insufficient knowledge of the mathematical and formal basis of relativity, which led to the criticisms often missing the heart of the matter. For example, relativity was misinterpreted as some form of relativism. However, this is misleading as it was emphasized by Einstein or Planck. On one hand it's true that space and time became relative, and the inertial frames of reference are handled on equal footing. On the other hand, the theory makes natural laws invariant—examples are the constancy of the speed of light, or the covariance of Maxwell's equations. Consequently, Felix Klein (1910) called it the "invariant theory of the Lorentz group" instead of relativity theory, and Einstein (who reportedly used expressions like "absolute theory") sympathized with this expression as well.Critical responses to relativity were also expressed by proponents of neo-Kantianism (Paul Natorp, Bruno Bauch etc.), and phenomenology (Oskar Becker, Moritz Geiger etc.). While some of them only rejected the philosophical consequences, others rejected also the physical consequences of the theory. Einstein was criticized for violating Immanuel Kant's categoric scheme, i.e., it was claimed that space-time curvature caused by matter and energy is impossible, since matter and energy already require the concepts of space and time. Also the three-dimensionality of space, Euclidean geometry, and the existence of absolute simultaneity were claimed to be necessary for the understanding of the world; none of them can possibly be altered by empirical findings. By moving all those concepts into a metaphysical area, any form of criticism of Kantianism would be prevented. Other pseudo-Kantians like Ernst Cassirer or Hans Reichenbach (1920), tried to modify Kant's philosophy. Subsequently, Reichenbach rejected Kantianism at all and became a proponent of logical positivism.Based on Henri Poincaré's conventionalism, philosophers such as Pierre Duhem (1914) and Hugo Dingler (1920) argued that the classical concepts of space, time, and geometry were, and will always be, the most convenient expressions in natural science, therefore the concepts of relativity cannot be correct. This was criticized by proponents of logical positivism such as Moritz Schlick, Rudolf Carnap, and Reichenbach. They argued that Poincaré's conventionalism could be modified to bring it into accord with relativity. Although it is true that the basic assumptions of Newtonian mechanics are simpler, it can only be brought into accord with modern experiments by inventing auxiliary hypotheses. On the other hand, relativity doesn't need such hypotheses, thus from a conceptual viewpoint, relativity is in fact simpler than Newtonian mechanics.Some proponents of Philosophy of Life, Vitalism, Critical realism (in German speaking countries) argued that there is a fundamental difference between physical, biological and psychological phenomena. For example, Henri Bergson (1921), who otherwise was a proponent of special relativity, argued that time dilation cannot be applied to biological organisms, therefore he denied the relativistic solution of the twin paradox. However, those claims were rejected by Paul Langevin, André Metz and others. Biological organisms consist of physical processes, so there is no reason to assume that they are not subject to relativistic effects like time dilation.Based on the philosophy of Fictionalism, the philosopher Oskar Kraus (1921) and others claimed that the foundations of relativity were only fictitious and even self-contradictory. Examples were the constancy of the speed of light, time dilation, length contraction. These effects appear to be mathematically consistent as a whole, but in reality they allegedly are not true. Yet, this view was immediately rejected. The foundations of relativity (such as the equivalence principle or the relativity principle) are not fictitious, but based on experimental results. Also, effects like constancy of the speed of light and relativity of simultaneity are not contradictory, but complementary to one another.In the Soviet Union (mostly in the 1920s), philosophical criticism was expressed on the basis of dialectic materialism. The theory of relativity was rejected as anti-materialistic and speculative, and a mechanistic worldview based on "common sense" was required as an alternative. Similar criticisms also occurred in the People's Republic of China during the Cultural Revolution. (On the other hand, other philosophers considered relativity as being compatible with Marxism.)
Relativity hype and popular criticism:
Although Planck already in 1909 compared the changes brought about by relativity with the Copernican Revolution, and although special relativity was accepted by most of the theoretical physicists and mathematicians by 1911, it was not before publication of the experimental results of the eclipse expeditions (1919) by a group around Arthur Stanley Eddington that relativity was noticed by the public. Following Eddington's publication of the eclipse results, Einstein was glowingly praised in the mass media, and was compared to Nikolaus Copernicus, Johannes Kepler and Isaac Newton, which caused a popular "relativity hype" ("Relativitätsrummel", as it was called by Sommerfeld, Einstein, and others). This triggered a counter-reaction of some scientists and scientific laymen who could not accept the concepts of modern physics, including relativity theory and quantum mechanics. The ensuing public controversy regarding the scientific status of Einstein's theory of gravity, which was unprecedented, was partly carried out in the press. Some of the criticism was not only directed to relativity, but personally at Einstein as well, who some of his critics accused of being behind the promotional campaign in the German press.
Relativity hype and popular criticism:
Academic and non-academic criticism Some academic scientists, especially experimental physicists such as the Nobel laureates Philipp Lenard and Johannes Stark, as well as Ernst Gehrcke, Stjepan Mohorovičić, Rudolf Tomaschek and others criticized the increasing abstraction and mathematization of modern physics, especially in the form of relativity theory, and later quantum mechanics. It was seen as a tendency to abstract theory building, connected with the loss of intuitive "common sense". In fact, relativity was the first theory, in which the inadequacy of the "illustrative" classical physics was thought to have been demonstrated. Some of Einstein's critics ignored these developments and tried to revitalize older theories, such as aether drag models or emission theories (see "Alternative Theories"). However, those qualitative models were never sufficiently advanced to compete with the success of the precise experimental predictions and explanatory powers of the modern theories. Additionally, there was also a great rivalry between experimental and theoretical physicists, as regards the professorial activities and the occupation of chairs at German universities. The opinions clashed at the "Bad Nauheim debates" in 1920 between Einstein and (among others) Lenard, which attracted much public attention.In addition, there were many critics (with or without physical training) whose ideas were far outside the scientific mainstream. These critics were mostly people who had developed their ideas long before the publication of Einstein's version of relativity, and they tried to resolve in a straightforward manner some or all of the enigmas of the world. Therefore, Wazeck (who studied some German examples) gave to these "free researchers" the name "world riddle solver" ("Welträtsellöser", such as Arvid Reuterdahl, Hermann Fricke or Johann Heinrich Ziegler). Their views had quite different roots in monism, Lebensreform, or occultism. Their views were typically characterized by the fact that they practically rejected the entire terminology and the (primarily mathematical) methods of modern science. Their works were published by private publishers, or in popular and non-specialist journals. It was significant for many "free researchers" (especially the monists) to explain all phenomena by intuitive and illustrative mechanical (or electrical) models, which also found its expression in their defense of the aether. For this reason they objected to the abstractness and inscrutability of the relativity theory, which was considered a pure calculation method that cannot reveal the true reasons underlying the phenomena. The "free researchers" often used Mechanical explanations of gravitation, in which gravity is caused by some sort of "aether pressure" or "mass pressure from a distance". Such models were regarded as an illustrative alternative to the abstract mathematical theories of gravitation of both Newton and Einstein. The enormous self-confidence of the "free researchers" is noteworthy, since they not only believed themselves to have solved the great riddles of the world, but many also seemed to expect that they would rapidly convince the scientific community.Since Einstein rarely defended himself against these attacks, this task was undertaken by other relativity theoreticians, who (according to Hentschel) formed some sort of "defensive belt" around Einstein. Some representatives were Max von Laue, Max Born, etc. and on popular-scientific and philosophical level Hans Reichenbach, André Metz etc., who led many discussions with critics in semi-popular journals and newspapers. However, most of these discussions failed from the start. Physicists like Gehrcke, some philosophers, and the "free researchers" were so obsessed with their own ideas and prejudices that they were unable to grasp the basics of relativity; consequently, the participants of the discussions were talking past each other. In fact, the theory that was criticized by them was not relativity at all, but rather a caricature of it. The "free researchers" were mostly ignored by the scientific community, but also, in time, respected physicists such as Lenard and Gehrcke found themselves in a position outside the scientific community. However, the critics didn't believe that this was due to their incorrect theories, but rather due to a conspiracy of the relativistic physicists (and in the 1920s and 1930s of the Jews as well), which allegedly tried to put down the critics, and to preserve and improve their own positions within the academic world. For example, Gehrcke (1920/24) held that the propagation of relativity is a product of some sort of mass suggestion. Therefore, he instructed a media monitoring service to collect over 5000 newspaper clippings which were related to relativity, and published his findings in a book. However, Gehrcke's claims were rejected, because the simple existence of the "relativity hype" says nothing about the validity of the theory, and thus it cannot be used for or against relativity.Afterward, some critics tried to improve their positions by the formation of alliances. One of them was the "Academy of Nations", which was founded in 1921 in the US by Robert T. Browne and Arvid Reuterdahl. Other members were Thomas Jefferson Jackson See and as well as Gehrcke and Mohorovičić in Germany. It is unknown whether other American critics such as Charles Lane Poor, Charles Francis Brush, Dayton Miller were also members. The alliance disappeared as early as the mid-1920s in Germany and by 1930 in the USA.
Relativity hype and popular criticism:
Chauvinism and antisemitism Shortly before and during World War I, there appeared some nationalistically motivated criticisms of relativity and modern physics. For example, Pierre Duhem regarded relativity as the product of the "too formal and abstract" German spirit, which was in conflict with the "common sense". Similarly, popular criticism in the Soviet Union and China, which partly was politically organized, rejected the theory not because of factual objections, but as ideologically motivated as the product of western decadence.So in those countries, the Germans or the Western civilization were the enemies. However, in Germany the Jewish ancestry of some leading relativity proponents such as Einstein and Minkowski made them targets of racially minded critics, although many of Einstein's German critics did not show evidence of such motives. The engineer Paul Weyland, a known nationalistic agitator, arranged the first public meeting against relativity in Berlin in 1919. While Lenard and Stark were also known for their nationalistic opinions, they declined to participate in Weyland's rallies, and Weyland's campaign eventually fizzled out due to a lack of prominent speakers. Lenard and others instead responded to Einstein's challenge to his professional critics to debate his theories at the scientific conference held annually at Bad Nauheim. While Einstein's critics, assuming without any real justification that Einstein was behind the activities of the German press in promoting the triumph of relativity, generally avoided antisemitic attacks in their earlier publications, it later became clear to many observers that antisemitism did play a significant role in some of the attacks.Reacting to this underlying mood, Einstein himself openly speculated in a newspaper article that in addition to insufficient knowledge of theoretical physics, antisemitism at least partly motivated their criticisms. Some critics, including Weyland, reacted angrily and claimed that such accusations of antisemitism were only made to force the critics into silence. However, subsequently Weyland, Lenard, Stark and others clearly showed their antisemitic biases by beginning to combine their criticisms with racism. For example, Theodor Fritsch emphasized the alleged negative consequences of the "Jewish spirit" within relativity physics, and the far right-press continued this propaganda unhindered. After the murder of Walther Rathenau (1922) and murder threats against Einstein, he left Berlin for some time. Gehrcke's book on "The mass suggestion of relativity theory" (1924) was not antisemitic itself, but it was praised by the far-right press as describing an alleged typical Jewish behavior, which was also imputed to Einstein personally. Philipp Lenard in 1922 spoke about the "foreign spirit" as the foundation of relativity, and afterward he joined the Nazi party in 1924; Johannes Stark did the same in 1930. Both were proponents of the so-called German Physics, which only accepted scientific knowledge based on experiments, and only if accessible to the senses. According to Lenard (1936), this is the "Aryan physics or physics by man of Nordic kind" as opposed to the alleged formal-dogmatic "Jewish physics". Additional antisemitic critics can be found in the writings of Wilhelm Müller, Bruno Thüring and others. For example, Müller erroneously claimed that relativity was a purely "Jewish affair" and it would correspond to the "Jewish essence" etc., while Thüring made comparisons between the Talmud and relativity.
Relativity hype and popular criticism:
Accusations of plagiarism and priority discussions Some of Einstein's critics, like Lenard, Gehrcke and Reuterdahl, accused him of plagiarism, and questioned his priority claims to the authorship of relativity theory. The thrust of such allegations was to promote more traditional alternatives to Einstein's abstract hypothetico-deductive approach to physics, while Einstein himself was to be personally discredited. It was argued by Einstein's supporters that such personal accusations were unwarranted, since the physical content and the applicability of former theories were quite different from Einstein's theory of relativity. However, others argued that between them Poincaré and Lorentz had earlier published several of the core elements of Einstein's 1905 relativity paper, including a generalized relativity principle that was intended by Poincaré to apply to all physics. Some examples: Johann Georg von Soldner (1801) was credited for his calculation of the deflection of light in the vicinity of celestial bodies, long before Einstein's prediction which was based on general relativity. However, Soldner's derivation has nothing to do with Einstein's, since it was fully based on Newton's theory, and only gave half of the value as predicted by general relativity.
Relativity hype and popular criticism:
Paul Gerber (1898) published a formula for the perihelion advance of Mercury, which was formally identical to an approximate solution given by Einstein. However, since Einstein's formula was only an approximation, the solutions are not identical. In addition, Gerber's derivation has no connection with General relativity and was even regarded as meaningless.
Woldemar Voigt (1887) derived a transformation, which is very similar to the Lorentz transformation. As Voigt himself acknowledged, his theory was not based on electromagnetic theory, but on an elastic aether model. His transformation also violates the relativity principle.
Friedrich Hasenöhrl (1904) applied the concept of electromagnetic mass and momentum (which were known long before) to cavity radiation and thermal radiation. Yet, the applicability of Einstein's Mass–energy equivalence goes much further, since it is derived from the relativity principle and applies to all forms of energy.
Relativity hype and popular criticism:
Menyhért Palágyi (1901) developed a philosophical "space-time" model in which time plays the role of an imaginary fourth dimension. Palágyi's model was only a reformulation of Newtonian physics, and had no connection to electromagnetic theory, the relativity principle, or to the constancy of the speed of light.Some contemporary historians of science have revived the question as to whether Einstein was possibly influenced by the ideas of Poincaré, who first stated the relativity principle and applied it to electrodynamics, developing interpretations and modifications of Lorentz's electron theory that appear to have anticipated what is now called special relativity. Another discussion concerns a possible mutual influence between Einstein and David Hilbert as regards completing the field equations of general relativity (see Relativity priority dispute).
Relativity hype and popular criticism:
A Hundred Authors Against Einstein A collection of various criticisms can be found in the book Hundert Autoren gegen Einstein (A Hundred Authors Against Einstein), published in 1931. It contains very short texts from 28 authors, and excerpts from the publications of another 19 authors. The rest consists of a list that also includes people who only for some time were opposed to relativity. From among Einstein's concepts the most targeted one is space-time followed by the speed of light as a constant and the relativity of simultaneity, with other concepts following. Besides philosophic objections (mostly based on Kantianism), also some alleged elementary failures of the theory were included; however, as some commented, those failures were due to the authors' misunderstanding of relativity. For example, Hans Reichenbach wrote a report in the entertainment section of a newspaper, describing the book as “a magnificent collection of naive mistakes” and as “unintended droll literature.” Albert von Brunn interpreted the book as a pamphlet "of such deplorable impotence as occurring elsewhere only in politics" and "a fallback into the 16th and 17th centuries" and concluded “it can only be hoped that German science will not again be embarrassed by such sad scribblings”, and Einstein said, in response to the book, that if he were wrong, then one author would have been enough.According to Goenner, the contributions to the book are a mixture of mathematical–physical incompetence, hubris, and the feelings of the critics of being suppressed by contemporary physicists advocating the new theory. The compilation of the authors show, Goenner continues, that this was not a reaction within the physics community—only one physicist (Karl Strehl) and three mathematicians (Jean-Marie Le Roux, Emanuel Lasker and Hjalmar Mellin) were present—but a reaction of an inadequately educated academic citizenship, which did not know what to do with relativity. As regards the average age of the authors: 57% were substantially older than Einstein, one third was around the same age, and only two persons were substantially younger. Two authors (Reuterdahl, von Mitis) were antisemitic and four others were possibly connected to the Nazi movement. On the other hand, no antisemitic expression can be found in the book, and it also included contributions of some authors of Jewish ancestry (Salomo Friedländer, Ludwig Goldschmidt, Hans Israel, Emanuel Lasker, Oskar Kraus, Menyhért Palágyi).
Status of criticism:
The theory of relativity is considered to be self-consistent, is consistent with many experimental results, and serves as the basis of many successful theories like quantum electrodynamics. Therefore, fundamental criticism (like that of Herbert Dingle, Louis Essen, Petr Beckmann, Maurice Allais and Tom van Flandern) has not been taken seriously by the scientific community, and due to the lack of quality of many critical publications (found in the process of peer review) they were rarely accepted for publication in reputable scientific journals. Just as in the 1920s, most critical works are published in small publication houses, alternative journals (like "Apeiron" or "Galilean Electrodynamics"), or private websites. Consequently, where criticism of relativity has been dealt with by the scientific community, it has mostly been in historical studies.However, this does not mean that there is no further development in modern physics. The progress of technology over time has led to extremely precise ways of testing the predictions of relativity, and so far it has successfully passed all tests (such as in particle accelerators to test special relativity, and by astronomical observations to test general relativity). In addition, in the theoretical field there is continuing research intended to unite general relativity and quantum theory, between which a fundamental incompatibility still remains. The most promising models are string theory and loop quantum gravity. Some variations of those models also predict violations of Lorentz invariance on a very small scale. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Androgen backdoor pathway**
Androgen backdoor pathway:
The androgen backdoor pathway is a collective name for all metabolic pathways where clinically relevant androgens are synthesized from 21-carbon steroids (pregnanes) by their 5α-reduction with roundabout of testosterone and/or androstenedione. Initially described as pathway where 5α-reduction of 17α-hydroxyprogesterone ultimately leads to 5α-dihydrotestosterone, several other pathways have been since then discovered that lead to 11-oxygenated androgens which are potent agonists of the androgen receptors. A backdoor pathway is an alternative to the conventional, canonical androgenic pathway that involves testosterone and/or androstenedione.
Introduction:
The androgen backdoor pathways are critical metabolic processes involved in the synthesis of clinically relevant androgens from 21-carbon steroids (pregnanes) through their 5α-reduction. These pathways occur without the involvement of testosterone and/or androstenedione, which are part of the conventional, canonical androgenic pathway. Initially, the 5α-reduction of 17α-hydroxyprogesterone was described in medical literature as a pathway that ultimately leads to the production of 5α-dihydrotestosterone. However, over the last two decades, several other distinct pathways have been discovered that lead to the synthesis of 11-oxygenated androgens, which are potent agonists of the androgen receptors. The androgen response mechanism occurs through the binding of androgens to cytosolic androgen receptors, which are translocated to the nucleus upon androgen binding and ultimately regulate gene transcription via androgen responsive elements. This response mechanism plays a crucial role in male sexual differentiation and puberty, as well as other tissue types and processes. The discovery of the backdoor pathway to 5α-dihydrotestosterone in the tammar wallaby in 2003 opened new avenues for understanding the biosynthesis of androgens in humans. Subsequently, other backdoor pathways leading to potent 11-oxygenated androgens have also been characterized, providing further insight into the synthesis of androgens in vivo. Understanding these pathways is critical for the development of effective treatments for conditions related to androgen biosynthesis.
Biochemistry:
Dihydrotestosterone backdoor biosynthesis The primary feature of the androgen backdoor pathway is that 17α-hydroxyprogesterone (17-OHP) can be 5α-reduced and finally converted to 5α-dihydrotestosterone (DHT) via an alternative route that bypasses the conventional intermediates androstenedione and testosterone.This route is activated during normal prenatal development and leads to early male sexual differentiation. It was first described in the marsupials and later confirmed in humans. Both the canonical and backdoor pathways of DHT biosynthesis are required for normal human male genital development, thus defects in the backdoor pathway from 17-OHP or progesterone (P4) to DHT lead to undervirilization in male fetuses because placental P4 is the precursor of DHT via the backdoor pathway.In 21-hydroxylase deficiency or cytochrome P450 oxidoreductase deficiency, this route may be activated regardless of age and sex by even a mild increase in circulating 17-OHP levels.While 5α-reduction is the last transformation in the classical androgen pathway, it is the first step in the backdoor pathways to 5α-dihydrotestosterone that acts on either 17-OHP or P4 which are ultimately converted to DHT.
Biochemistry:
17α-Hydroxyprogesterone pathway The first step of this pathway is the 5α-reduction of 17-OHP to 5α-pregnan-17α-ol-3,20-dione (17OHDHP, since it is also known as 17α-hydroxy-dihydroprogesterone). The reaction is catalyzed by SRD5A1.
17OHDHP is then converted to 5α-pregnane-3α,17α-diol-20-one (5α-Pdiol) via 3α-reduction by a 3α-hydroxysteroid dehydrogenase isozyme (AKR1C2 and AKR1C4) or HSD17B6, that also has 3α-reduction activity. 5α-Pdiol is also known as 17α-hydroxyallopregnanolone or 17OH-allopregnanolone.
5α-Pdiol is then converted to 5α-androstan-3α-ol-17-one, also known as androsterone (AST) by 17,20-lyase activity of CYP17A1 which cleaves a side-chain (C17-C20 bond) from the steroid nucleus, converting a C21 steroid (a pregnane) to C19 steroid (an androstane or androgen). AST is 17β-reduced to 5α-androstane-3α,17β-diol (3α-diol) by HSD17B3 or AKR1C3.
The final step is 3α-oxidation of 3α-diol in target tissues to DHT by an enzyme that has 3α-hydroxysteroid oxidase activity, such as AKR1C2, HSD17B6, HSD17B10, RDH16, RDH5, and DHRS9. This oxidation is not required in the classical androgen pathway. The pathway can be summarized as: 17-OHP → 17OHDHP → 5α-Pdiol → AST → 3α-diol → DHT.
Biochemistry:
Progesterone pathway The pathway from progesterone (P4) to DHT is similar to that described above from 17-OHP to DHT, but the initial substrate for 5α-reductase here is P4 rather than 17-OHP. Placental P4 in the male fetus is the feedstock for the backdoor pathway found operating in multiple non-gonadal tissues. The first step in this pathway is 5α-reduction of P4 towards 5α-dihydroprogesterone (5α-DHP) by SRD5A1. 5α-DHP is then converted to allopregnanolone (AlloP5) via 3α-reduction by AKR1C2 or AKR1C4. AlloP5 is then converted to 5α-Pdiol by the 17α-hydroxylase activity of CYP17A1. The pathway then proceeds the same way as the pathway that starts from 17-OHP, and can be summarized as: P4 → 5α-DHP → AlloP5 → 5α-Pdiol → AST → 3α-diol → DHT.
Biochemistry:
11-Oxygenated androgen backdoor biosynthesis There are two known 11-oxygenated androgens, 11-ketotestosterone (11KT) and 11-ketodihydrotestosterone (11KDHT), which both bind and activate the androgen receptor with affinities, potencies, and efficacies that are similar to that of T and DHT, respectively. Some work suggests that though 11β-hydroxytestosterone (11OHT) and 11β-hydroxydihydrotestosterone (11OHDHT) may not have significant androgenic activity as they were once thought to possess, they may still be important precursors to androgenic molecules. The relative importance of the androgens depends on their activity, circulating levels and stability. The steroids 11OHA4 and 11KA4 have been established as having minimal androgen activity, but remain important molecules in this context since they act as androgen precursors.
Biochemistry:
The backdoor pathways to 11-oxygenated androgens can be broadly as two Δ4 steroid entry points (17-OHP and P4) that can undergo a common sequence of three transformations: 11β-hydroxylation by CYP11B1 in the adrenal cortex, 5α-reduction by SRD5A1/SRD5A1, reversible 3α-reduction/oxidation of the ketone/alcohol by AKR1C2 or AKR1C4.
Clinical significance:
In congenital adrenal hyperplasia (CAH) due to deficiency of 21-hydroxylase or cytochrome P450 oxidoreductase (POR), the associated elevated 17-OHP levels result in flux through the backdoor pathway to DHT that begins with 5α-reduction of 17-OHP . This pathway may be activated regardless of age and sex. Fetal excess of 17-OHP in CAH may contribute to DHT synthesis that leads to external genital virilization in newborn girls with CAH. P4 levels may also be elevated in CAH, leading to androgen excess via the backdoor pathway from P4 to DHT. 17-OHP and P4 may also serve as substrates to 11-oxygenated androgens in CAH.Serum levels of the C21 11-oxygenated steroids: 21-deoxycorticosterone (11OHP4) and 21-deoxycortisol (21dF), have been known to be elevated in both non-classical and classical forms of CAH since about 1990, and liquid chromatography–mass spectrometry profiles that include these steroids have been proposed for clinical applications. Classical CAH patients receiving glucocorticoid therapy had C19 11-oxygenated steroid serum levels that were elevated 3-4 fold compared to healthy controls. In that same study, the levels of C19 11-oxygenated androgens correlated positively with conventional androgens in women but negatively in men. The levels of 11KT were 4 times higher compared to that of T in women with the condition. In adult women with CAH, the ratio of DHT produced in a backdoor pathway to that produced in a conventional pathway increases as control of androgen excess by glucocorticoid therapy deteriorates. In CAH patients with poor disease control, 11-oxygenated androgens remain elevated for longer than 17-OHP, thus serving as a better biomarker for the effectiveness of the disease control. In males with CAH, 11-oxygenated androgen levels may indicate the presence testicular adrenal rest tumors.
Clinical significance:
Both the classical and backdoor androgen pathway to DHT are required for normal human male genital development. Deficiencies in the backdoor pathway to DHT from 17-OHP or from P4 lead to underverilization of the male fetus, as placental P4 is a precursor to DHT in the backdoor pathway.A case study of five 46,XY (male) patients from two families demonstrated that atypical genital appearance were attributed to mutations in AKR1C2 and/or AKR1C4, which operate exclusively in the backdoor pathway to DHT. Mutations in the AKR1C3 and genes involved in the classical androgen pathway were excluded as the causes for the atypical appearance. The 46,XX (female) relatives of affected patients, having the same mutations, were phenotypically normal and fertile. Although both AKR1C2 and AKR1C4 are needed for DHT synthesis in a backdoor pathway, the study found that mutations in AKR1C2 only were sufficient for disruption. However, these AKR1C2/AKR1C4 variants leading to DSD are rare and have been only so far reported in just those two families. This case study emphasizes the role of AKR1C2/4 in the alternative androgen pathways.
Clinical significance:
Isolated 17,20-lyase deficiency syndrome due to variants in CYP17A1, cytochrome b5, and POR may also disrupt the backdoor pathway to DHT, as the 17,20-lyase activity of CYP17A1 is required for both classical and backdoor androgen pathways. This rare deficiency can lead to DSD in both sexes, with affected girls being asymptomatic until puberty, when they show amenorrhea.11-oxygenated androgens may play important roles in DSDs. 11-oxygenated androgen fetal biosynthesis may coincide with the key stages of production of cortisol — at weeks 8–9, 13–24, and from 31 and onwards. In these stages, impaired CYP17A1 and CYP21A2 activity lead to increased ACTH due to cortisol deficiency and the accumulation of substrates for CYP11B1 in pathways to 11-oxygenated androgens and could cause abnormal female fetal development.
History:
In 1987, Eckstein et al. incubated rat testicular microsomes in the presence of radiolabelled steroids and demonstrated that 5α-androstane-3α,17β-diol is preferentially produced from 17α-hydroxyprogesterone (17-OHP ). While "androstanediol" was used to denote both 5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol, "3α-diol" is used here to abbreviate 5α-androstane-3α,17β-diol in this paper as it is a common convention and emphasizes it as the 3α-reduced derivative of DHT. The function of 3α-diol was not known at that time.
History:
In 2000, Shaw et al. demonstrated that circulating 3α-diol mediates prostate development in tammar wallaby pouch young via conversion to DHT in target tissues. Tammar wallaby pouch young do not show sexually dimorphic circulating levels of T and DHT during prostate development which suggested that another androgenization mechanism was responsible. While 3α-diol's androgen receptor binding affinity is five orders of magnitude lower than DHT (generally described as AR inactive), it was known 3α-diol can be oxidized back to DHT via the action of a number of dehydrogenases.In 2003, Wilson et al. incubated the testes of tammar wallaby pouch young with radiolabelled progesterone to show that 5α-reductase expression in this tissue enabled a novel pathway from 17-OHP to 3α-diol without T as an intermediate: 17-OHP → 17OHDHP → 5α-Pdiol → AST → 3α-diol.
History:
In 2004, Mahendroo et al. demonstrated that an overlapping novel pathway is operating in mouse testes, generalizing what had been demonstrated in tammar wallaby: P4 → 5α-DHP → AlloP5→ 5α-Pdiol → AST → 3α-diol.
History:
The term "backdoor pathway" was coined by Auchus in 2004 and defined as a route to DHT that: 1) bypasses conventional intermediates androstenedione (A4) and T; 2) involves 5α-reduction of 21-carbon (C21) pregnanes to 19-carbon (C19) androstanes; and 3) involves the 3α-oxidation of 3α-diol to DHT. The backdoor pathway explained how androgens are produced under certain normal and pathological conditions in humans when the classical androgen pathway cannot fully explain the observed consequences. The pathway Auchus defined adds DHT to the terminus of the pathway described by Wilson et al. in 2003: 17-OHP → 17OHDHP → 5α-Pdiol → AST → 3α-diol → DHT.
History:
The clinical relevance of these results was demonstrated in 2012 for the first time when Kamrath et al. attributed the urinary metabolites to the androgen backdoor pathway from 17-OHP to DHT in patients with steroid 21-hydroxylase (encoded by the gene CYP21A2) enzyme deficiency.
History:
Barnard et al. in 2017 demonstrated metabolic pathways from C21 steroids to 11KDHT that bypasses A4 and T in vitro in a prostate cancer derived cell line, an aspect that is similar to that of the backdoor pathway to DHT. These newly discovered pathways to 11-oxygenated androgens were also described as "backdoor" pathways due to this similarity, and were further characterized in subsequent studies.
Note:
This article was submitted to WikiJournal of Medicine for external academic peer review in 2022 (reviewer reports). The updated content was reintegrated into the Wikipedia page under a CC-BY-SA-3.0 license (2023). The version of record as reviewed is: Maxim Masiutin; Maneesh Yadav; et al. (3 April 2023). "Alternative androgen pathways" (PDF). WikiJournal of Medicine. 10 (1): 3. doi:10.15347/WJM/2023.003. ISSN 2002-4436. Wikidata Q100737840. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Intercostal nerve block**
Intercostal nerve block:
Intercostal nerve block (abbreviated ICNB) is a nerve block which temporarily or permanently interrupts the flow of signals along an intercostal nerve, usually performed to relieve pain.
Uses:
An ICNB relieves the pain associated with injured intercostal nerves. This pain can arise from chest surgery, physical trauma, aggravation of the shingles virus, or pressure put upon the nerves during pregnancy.
Techniques:
Anesthetic nerve block Injecting local pain relievers and steroids into the injured area alleviates intercostal nerve pain. In this type of nerve block, a needle inserted between two ribs releases a steroid into the area around the nerve. The exact location of injection depends on the underlying cause of the injury. After three to five days, the steroid begins to relieve pain. Depending on the individual, the pain-relieving effects of the steroid last for days to several months.
Techniques:
Risks Injection without a device such as an ultrasound or fluoroscope to guide the needle can cause pneumothorax, a condition where air enters the cavity surrounding the lung or into a blood vessel causing local anesthetic toxicity. Other newer facial plane blocks may be an alternative option due to a preferential safety profile Neurolysis Physicians can also treat intercostal nerve pain by intentionally damaging the intercostal nerves. This process, known as neurolysis, prevents the nerves from sending pain signals. In chemical neurolysis, a needle injects alcohol or phenol into the nerve and prevents the conduction of pain signals. Neurolysis can also be accomplished through a process known as radio-frequency lesioning. In radio-frequency lesioning, a needle transmits radio waves to the nerve and interrupts regular pain signaling. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**SilverFast**
SilverFast:
SilverFast is the name of a family of software for image scanning and processing, including photos, documents and slides, developed by LaserSoft Imaging.
There are also other applications for image processing using digital cameras or printers and for 48-bit raw data image processing.
History:
SilverFast was introduced in 1995, it is still under development today. Some scanner manufacturers bundle their hardware with SilverFast software. Some of the features developed for SilverFast, especially in the area of color management, error detection and automatic dust and scratch removal, have been patented. The European Digital Press Association named SilverFast the "Best colour management software of the year 2008" for improving the dynamic range of most scanners and for creating ICC profiles automatically. In 2011 version 8 was introduced, and HDR imaging software followed in 2012. SilverFast 9 has been released in 2020.
History:
Patents 2005: Patent granted on barcode technology used for the Auto IT8 Calibration. (Karl-Heinz Zahorsky, EP: 1594301) 2008: Patent granted on technology used for SilverFast Multi-Exposure@. (Karl-Heinz Zahorsky, EP: 1744278, US 8,693,808) 2021: Patent pending for a scanning method that reduces scanning time for flatbed scanners. (Karl-Heinz Zahorsky, German, European and US patents pending)
Products:
SilverFast is offered individually adjusted to the respective scanner model. If several scanners are operated, it is therefore necessary to purchase a corresponding number of additional licenses. Upgrade rates are also offered when purchasing a new scanner.
Products:
Overview of the available products: 1) including: Multi-Exposure 2) optional: ICC Printer Calibration Optional features As marked in the table above, some products are available with additional features: Multi-Exposure – Multi-Exposure is an exposure blending technique for scanning transparent originals like slides, negatives, and film strips with increased dynamic range. This is accomplished by scanning the original multiple times with different exposure times, increasing the dynamic range and preserving detail in the light and shadow areas of the image. Multi-Exposure does not work with reflective originals and differs from "Multi-Sampling," which also scans multiple times but with unaltered exposure.
Products:
ICC Printer Calibration – The SilverFast ICC Printer Calibration calibrates the printer using a previously calibrated flatbed scanner as the measuring device for profiling the printer.
Products:
SilverFast Scanner Software It can be used as a stand-alone application, as a Photoshop plug-in, or as a universal TWAIN module. Versions include: SilverFast SE (basic edition) SilverFast SE Plus (plus edition / with Multi-Exposure) SilverFast Ai Studio (premium edition) SilverFast X-Ray (a special version of SilverFast designed to digitize radiographic films for scientific and medical radiography) SilverFast HDR Software SilverFast HDR is a computer program for processing 48-bit raw images. Many newer scanners are able to output the image directly with all existing data instead of breaking it down to 24-bit. This 48-bit raw image can be saved immediately and digital processing performed later.
Products:
SilverFast HDR (basic edition) SilverFast HDR Studio (premium edition)SilverFast HDR contains the functionality of SilverFast Ai Studio for 48-bit raw data, such as defining output size and resolution, auto-adjusting of highlights and shadows, three-part histogram, gradation curves, selective color correction, unsharp masking, color cast removal slider, color separation, and CMYK-preview. SilverFast HDR can be used as a native plug-in for Adobe Photoshop, as a universal TWAIN module, or as a stand-alone application.
Products:
The HDR Studio has AACO (Auto-Adaptive Contrast Optimization), JPEG 2000, USMPlus (Unsharp Mask Plus), CloneTool and PrinTao.
Products:
HDRi (64Bit RAW data with infrared channel) With version 6.6.1 any SilverFast HDR version supports the proprietary RAW data format HDRi. These 64-bit HDRi color files and 32-bit HDRi greyscale files contain additional 16-bit infrared RAW data besides the 48-bit color RAW data and 16-bit greyscale RAW data respectively. Therefore, a scanner with an infrared channel available to the software is necessary. This RAW format can keep any readable image information for later post-processing.
Products:
The acronym "HDR" as used by SilverFast is not related to High-dynamic-range imaging, a widely used technique to increase the dynamic range of (digital) images.
The data format is: SilverFast Archiving Software The SilverFast Archive Suite includes SilverFast Ai Studio and SilverFast HDR Studio with an integrated color management system. This package is suitable for archiving slides, negatives, and photos, whereas the post processing can take place anytime after scanning.
SilverFast Archive Suite - consisting of SilverFast Ai Studio and SilverFast HDR Studio (premium edition) PrintTao 8 PrintTao 8 is for Canon and Epson large format printers. It can be used as a stand-alone application or as a plug-in for Adobe Photoshop and Adobe Lightroom.
PrinTao 8 takes over color management and all printer driver settings. It contains various printing templates like pack templates for portrait photographers or gallery wrap templates for printing on canvas.
SRDx Photoshop Plug-in SRDx (Smart Removal of Defects) is a plug-in for Adobe Photoshop to remove defects like dust particles, specks, small scratches and finger prints from digital images.
Most dust and scratch removal tools use blur effects which degrade overall image quality. SRDx works without any unsharping effects. SRDx uses an adjustable automatic detection of dust and scratches that can be fine-tuned manually using a defect marker and a rubber tool.
SilverFast DC SilverFast DC has been discontinued. SilverFast DC was a stand-alone software for digital camera image processing. It contained features for reading the image data from the camera, for processing, optimizing, and archiving the images on the computer, as well as for printing the edited images.
IT8 calibration & color management:
Scanner calibration: SilverFast is equipped with a color management system that enables largely automated IT8 color calibration of the scanner using IT8 targets supplied by the manufacturer LaserSoft Imaging.
IT8 calibration & color management:
according to ISO standard 12641-1 (from 1993): conventional standard according to ISO standard 12641-2 (from 2020): new standard for a more precise IT8 calibration with about 3 times the number of measuring fields. LaserSoft Imaging cooperated for creating this standard.Printer calibration: SilverFast also enables printer calibration by printing a color table and then scanning it using an already calibrated scanner to create an ICC profile.
Supported devices:
SilverFast supports 325 scanners.
Most Microsoft Windows-only 35mm USB scanners sold under various names are not supported. Each scanner model requires a separate license.
Heidelberg drum scanner:
SilverFast Ai Studio supports prepress drum scanners made by Heidelberger Druckmaschinen AG (Linotype - Hell) on Microsoft Windows 2000, XP, Vista and 7, as well as Mac OS X 10.3-10.5 operating systems. Supported models include the Chromagraph 3300/3400, Tango/XL, Topaz, Nexscan, and Primescan. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Grsync**
Grsync:
Grsync is a graphical user interface for rsync. rsync is a differential backup and file synchronization tool widely used in Unix-like operating systems.
Grsync is developed with the GTK widget toolkit. Like rsync, Grsync is free and open-source software licensed under the GNU General Public License.
About:
Rsync is a tool for creating backups in Linux systems. It supports backing up local folders, SSH tunneling, delta-only synchronization, and so on.
Grsync adds the ability to use such purposes with a graphical user interface, without rsync's need to learn a complex set of command-line arguments. In some cases, it is easier to backup files with grsync than with rsync. Since version 1.3.0, Grsync has GTK-3 compatibility. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**CTAN**
CTAN:
CTAN (an acronym for "Comprehensive TeX Archive Network") is the authoritative place where TeX related material and software can be found for download. Repositories for other projects, such as the MiKTeX distribution of TeX, constantly mirror most of CTAN.
History:
Before CTAN there were a number of people who made some TeX materials available for public download, but there was no systematic collection. At a podium discussion that Joachim Schrod organized at the 1991 EuroTeX conference, the idea arose to bring together the separate collections. (Joachim was interested in this topic because he is active in the TeX community since 1983 and ran one of the largest ftp servers in Germany at that time.) CTAN was built in 1992, by Rainer Schöpf and Joachim Schrod in Germany, Sebastian Rahtz in the UK, and George Greenwade in the U.S. (George came up with the name). Today, there are still only four people who maintain the archives and the TeX catalogue updates: Erik Braun, Ina Dau, Manfred Lotz, and Petra Ruebe-Pugliese. The site structure was put together at the start of 1992 – Sebastian did the main work – and synchronized at the start of 1993. The TeX Users Group provided a framework, a Technical Working Group, for this task's organization. CTAN was officially announced at the EuroTeX conference at Aston University, 1993. The WEB server itself is maintained by Gerd Neugebauer.
History:
The English site has been stable since the beginning, but both the American and the German sites have moved thrice. The American site was first at Sam Houston State University under George Greenwade, in 1995 it moved to UMass Boston where it was run by Karl Berry. In 1999 it moved to Saint Michael's College in Colchester, Vermont. There it was announced to go off-line in the end of January 2011. Since January 2013, a mirror has been hosted by the University of Utah (no upload node). The German site was first at the University of Heidelberg, operated by Rainer; in 1999 it moved to the University of Mainz, also operated by Rainer; 2002 to the University of Hamburg, operated by Reinhard Zierke; finally in 2005 it moved to a commercial hosting company since the amount of traffic got too high to get sponsored by a university. The German site is subsidized by DANTE, the Deutschsprachige Anwendervereinigung TeX.
History:
Today, the main CTAN nodes serve downloads of more than 6 TB per month, not counting its 94 mirror sites worldwide. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Designing Virtual Worlds**
Designing Virtual Worlds:
Designing Virtual Worlds is a book about the practice of virtual world development by Richard Bartle. It has been noted as an authoritative source regarding the history of world-based online games. College courses have been taught using it.In 2021, the author made the book freely available under a Creative Commons license on his website.
Contents:
Designing Virtual Worlds argues that the fundamentals of player relationships to the virtual world and each other are independent of technical issues and are characterized by a blending of online and offline identity. According to the book, it is the designer's role to know what will provide players with a positive game experience, the purpose of virtual worlds is the player's exploration of self, as well as for its expansion of the earlier 4-type Bartle gamer style taxonomy into an 8-type model. The book also focuses on the practicalities of its subject.
Reception:
It has been called "the bible of MMORPG design" and spoken of as "excellent", "seminal", "widely read", "the standard text on the subject", "the most comprehensive guide to gaming virtual worlds" and "a foundation text for researchers and developers of virtual worlds" that is "strongly recommended for anyone actually thinking about building one of these places" and "describes the minimum level of competency you should have when discussing design issues for virtual worlds".In less favorable reception, one reviewer, while calling it a "must-read" work, said he found "much that was questionable, incomplete, or just erroneous" in it. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Tropical Storm Sandy**
Tropical Storm Sandy:
The name Sandy has been used for two tropical cyclones worldwide, one in the Atlantic ocean and one in the Australian Region.
In the Atlantic: Hurricane Sandy (2012) – a Category 3 major hurricane that inflicted nearly $70 billion (2012 USD) in damage and killed 233 people across eight countries from the Caribbean to Canada.The name was retired in the Atlantic after the 2012 hurricane season and was replaced with Sara.
Australian region: Cyclone Sandy (1985) – a severe tropical cyclone that affected Northern Australia.The name was retired in Australian region after the 1984–85 cyclone season. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Subtitle (titling)**
Subtitle (titling):
In books and other works, the subtitle is an explanatory title added by the author to the title proper of a work. Another kind of subtitle, often used in the past, is the alternative title, also called alternate title, traditionally denoted and added to the title with the alternative conjunction "or", hence its appellation.As an example, Mary Shelley gave her most famous novel the title Frankenstein; or, The Modern Prometheus, where or, The Modern Prometheus is the alternative title, by which she references the Greek Titan as a hint of the novel's themes.A more modern usage is to simply separate the subtitle by punctuation, making the subtitle more of a continuation or sub-element of the title proper.
Subtitle (titling):
In library cataloging and in bibliography, the subtitle does not include an alternative title, which is defined as part of the title proper: e.g., One Good Turn: A Natural History of the Screwdriver and the Screw is filed as One Good Turn (title) and A Natural History of the Screwdriver and the Screw (subtitle), while Twelfth Night, or What You Will is filed as Twelfth Night, or What You Will (title).
Literature:
Subtitles and alternative titles for plays were fashionable in the Elizabethan era. William Shakespeare parodied this vogue by giving the comedy Twelfth Night his only subtitle, the deliberately uninformative or What You Will, implying that the subtitle can be whatever the audience wants it to be.In printing, subtitles often appear below the title in a less prominent typeface or following the title after a colon.
Literature:
Some modern publishers choose to forget subtitles when republishing historical works, such as Shelley's famous story, which is often now sold simply as Frankenstein.
Non-fiction:
In political philosophy, for example, the 16th-century theorist Thomas Hobbes named his magnum opus Leviathan or The Matter, Forme and Power of a Common-Wealth Ecclesiasticall and Civil, using the subtitle to explain the subject matter of the book.
Film and other media:
In film, examples of subtitles using "or" include Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb and Birdman or (The Unexpected Virtue of Ignorance).
Film and other media:
Subtitles are also used to distinguish different installments in a series, instead of or in addition to a number, such as: Pirates of the Caribbean: Dead Man's Chest, the second in the Pirates of the Caribbean series; Mario Kart: Super Circuit, the third in the Mario Kart series; and Star Trek II: The Wrath of Khan, the second in the Star Trek series. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Electron beam texturing**
Electron beam texturing:
Electron beam texturing (EBT) is a technology used to apply roughness to the surface of rolling mill cylinders by impinging the surface of these cylinders with a modulated electron beam. The beam locally melts the surface of the cylinder, producing crater-like depressions.
The technology was originally developed by the German company Linotype-Hell for application in the printing industry, but eventually found its successful application in the metal rolling industry, where it is competing with alternative texturing technologies, such as electrodischarge texturing. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Alzheimer's Research & Therapy**
Alzheimer's Research & Therapy:
Alzheimer's Research & Therapy is a monthly peer-reviewed medical journal covering research on Alzheimer's disease. It was established in 2009 and is published by BioMed Central. The editors-in-chief are Douglas R. Galasko (University of California, San Diego), Todd E. Golde (University of Florida), and Philip Scheltens (VU University Medical Center).
Abstracting and indexing:
The journal is abstracted and indexed in Chemical Abstracts Service, Embase, Science Citation Index Expanded, and Scopus. According to the Journal Citation Reports the journal has a 2015 impact factor of 5.197. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cumulative hierarchy**
Cumulative hierarchy:
In mathematics, specifically set theory, a cumulative hierarchy is a family of sets Wα indexed by ordinals α such that Wα⊆Wα+1 If λ is a limit ordinal, then {\textstyle W_{\lambda }=\bigcup _{\alpha <\lambda }W_{\alpha }} Some authors additionally require that Wα+1⊆P(Wα) or that W0≠∅ .The union {\textstyle W=\bigcup _{\alpha \in \mathrm {On} }W_{\alpha }} of the sets of a cumulative hierarchy is often used as a model of set theory.The phrase "the cumulative hierarchy" usually refers to the standard cumulative hierarchy Vα of the von Neumann universe with Vα+1=P(Wα) introduced by Zermelo (1930).
Reflection principle:
A cumulative hierarchy satisfies a form of the reflection principle: any formula in the language of set theory that holds in the union W of the hierarchy also holds in some stages Wα
Examples:
The von Neumann universe is built from a cumulative hierarchy Vα The sets Lα of the constructible universe form a cumulative hierarchy.
The Boolean-valued models constructed by forcing are built using a cumulative hierarchy.
The well founded sets in a model of set theory (possibly not satisfying the axiom of foundation) form a cumulative hierarchy whose union satisfies the axiom of foundation. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Redheffer matrix**
Redheffer matrix:
In mathematics, a Redheffer matrix, often denoted An as studied by Redheffer (1977), is a square (0,1) matrix whose entries aij are 1 if i divides j or if j = 1; otherwise, aij = 0. It is useful in some contexts to express Dirichlet convolution, or convolved divisors sums, in terms of matrix products involving the transpose of the nth Redheffer matrix.
Variants and definitions of component matrices:
Since the invertibility of the Redheffer matrices are complicated by the initial column of ones in the matrix, it is often convenient to express := Cn+Dn where := [cij] is defined to be the (0,1) matrix whose entries are one if and only if j=1 and i≠1 . The remaining one-valued entries in An then correspond to the divisibility condition reflected by the matrix Dn , which plainly can be seen by an application of Mobius inversion is always invertible with inverse Dn−1=[μ(j/i)Mi(j)] . We then have a characterization of the singularity of An expressed by det det (Dn−1Cn+In).
Variants and definitions of component matrices:
If we define the function := if j divides i; otherwise, , then we can define the nth Redheffer (transpose) matrix to be the nxn square matrix Rn=[Mj(i)]1≤i,j≤n in usual matrix notation. We will continue to make use this notation throughout the next sections.
Examples:
The matrix below is the 12 × 12 Redheffer matrix. In the split sum-of-matrices notation for 12 := 12 12 , the entries below corresponding to the initial column of ones in Cn are marked in blue. (111111111111110101010101101001001001100100010001100010000100100001000001100000100000100000010000100000001000100000000100100000000010100000000001) A corresponding application of the Mobius inversion formula shows that the nth Redheffer transpose matrix is always invertible, with inverse entries given by Rn−1=[Mj(i)⋅μ(ij)]1≤i,j≤n, where μ(n) denotes the Moebius function. In this case, we have that the 12 12 inverse Redheffer transpose matrix is given by 12 −1=(100000000000−110000000000−1010000000000−10100000000−1000100000001−1−1001000000−100000100000000−10001000000−10000010001−100−10000100−100000000010010−10−1000001)
Key properties:
Singularity and relations to the Mertens function and special series Determinants The determinant of the n × n square Redheffer matrix is given by the Mertens function M(n). In particular, the matrix An is not invertible precisely when the Mertens function is zero (or is close to changing signs). As a corollary of the disproof of the Mertens conjecture, it follows that the Mertens function changes sign, and is therefore zero, infinitely many times, so the Redheffer matrix An is singular at infinitely many natural numbers.
Key properties:
The determinants of the Redheffer matrices are immediately tied to the Riemann Hypothesis through this relation with the Mertens function, since the Hypothesis is equivalent to showing that M(x)=O(x1/2+ε) for all (sufficiently small) ε>0 Factorizations of sums encoded by these matrices In a somewhat unconventional construction which reinterprets the (0,1) matrix entries to denote inclusion in some increasing sequence of indexing sets, we can see that these matrices are also related to factorizations of Lambert series. This observation is offered in so much as for a fixed arithmetic function f, the coefficients of the next Lambert series expansion over f provide a so-called inclusion mask for the indices over which we sum f to arrive at the series coefficients of these expansions. Notably, observe that ∑d|nf(d)=∑k=1nMk(n)⋅f(k)=[qn](∑n≥1f(n)qn1−qn).
Key properties:
Now in the special case of these divisor sums, which we can see from the above expansion, are codified by boolean (zero-one) valued inclusion in the sets of divisors of a natural number n, it is possible to re-interpret the Lambert series generating functions which enumerate these sums via yet another matrix-based construction. Namely, Merca and Schmidt (2017-2018) proved invertible matrix factorizations expanding these generating functions in the form of ∑n≥1f(n)qn1−qn=1(q;q)∞∑n≥1(∑k=1nsn,kf(k))qn, where (q;q)∞ denotes the infinite q-Pochhammer symbol and where the lower triangular matrix sequence is exactly generated as the coefficients of sn,k=[qn]qk1−qk(q;q)∞ , through these terms also have interpretations as differences of special even (odd) indexed partition functions. Merca and Schmidt (2017) also proved a simple inversion formula which allows the implicit function f to be expressed as a sum over the convolved coefficients ℓ(n)=(f∗1)(n) of the original Lambert series generating function in the form of f(n)=∑d|n∑k=1np(d−k)μ(n/d)[∑j≥0k−j≥0ℓ(k−j)[qj](q;q)∞], where p(n) denotes the partition function, μ(n) is the Moebius function, and the coefficients of (q;q)∞ inherit a quadratic dependence on j through the pentagonal number theorem. This inversion formula is compared to the inverses (when they exist) of the Redheffer matrices An for the sake of completion here.
Key properties:
Other than that the underlying so-termed mask matrix which specifies the inclusion of indices in the divisor sums at hand are invertible, utilizing this type of construction to expand other Redheffer-like matrices for other special number theoretic sums need not be limited to those forms classically studied here. For example, in 2018 Mousavi and Schmidt extend such matrix based factorization lemmas to the cases of Anderson-Apostol divisor sums (of which Ramanujan sums are a notable special case) and sums indexed over the integers that are relatively prime to each n (for example, as classically defines the tally denoted by the Euler phi function). More to the point, the examples considered in the applications section below suggest a study of the properties of what can be considered generalized Redheffer matrices representing other special number theoretic sums.
Key properties:
Spectral radius and eigenspaces If we denote the spectral radius of An by ρn , i.e., the dominant maximum modulus eigenvalue in the spectrum of An , then lim n→∞ρnn=1, which bounds the asymptotic behavior of the spectrum of An when n is large. It can also be shown that log n) , and by a careful analysis (see the characteristic polynomial expansions below) that log n+O(1) The matrix An has eigenvalue one with multiplicity log 2(n)⌋−1 The dimension of the eigenspace Eλ(An) corresponding to the eigenvalue := 1 is known to be ⌊n2⌋−1 . In particular, this implies that An is not diagonalizable whenever n≥5 For all other eigenvalues λ≠1 of An , then dimension of the corresponding eigenspaces Eλ(An) are one.
Key properties:
Characterizing eigenvectors We have that [a1,a2,…,an] is an eigenvector of AnT corresponding to some eigenvalue λ∈σ(An) in the spectrum of An if and only if for n≥2 the following two conditions hold: and λa1=∑k=1nak.
If we restrict ourselves to the so-called non-trivial cases where λ≠1 , then given any initial eigenvector component a1 we can recursively compute the remaining n-1 components according to the formula aj=1λ−1∑d|jd<jad.
With this in mind, for λ≠1 we can define the sequences of := 2.
There are a couple of curious implications related to the definitions of these sequences. First, we have that λ∈σ(An) if and only if ∑k=1nvλ(k)=λ.
Secondly, we have an established formula for the Dirichlet series, or Dirichlet generating function, over these sequences for fixed λ≠1 which holds for all ℜ(s)>1 given by ∑n≥1vλ(n)ns=λ−1λ−ζ(s), where ζ(s) of course as usual denotes the Riemann zeta function.
Key properties:
Bounds and properties of non-trivial eigenvalues A graph theoretic interpretation to evaluating the zeros of the characteristic polynomial of An and bounding its coefficients is given in Section 5.1 of. Estimates of the sizes of the Jordan blocks of An corresponding to the eigenvalue one are given in. A brief overview of the properties of a modified approach to factorizing the characteristic polynomial, pAn(x) , of these matrices is defined here without the full scope of the somewhat technical proofs justifying the bounds from the references cited above. Namely, let the shorthand := log 2(n)⌋ and define a sequence of auxiliary polynomial expansions according to the formula := pAn(t+1)tn−s−1=ts+1−∑k=1svnkts−k.
Key properties:
Then we know that fn(t) has two real roots, denoted by tn± , which satisfy log log 2(n)n), where 0.577216 is Euler's classical gamma constant, and where the remaining coefficients of these polynomials are bounded by log k−1(n)(k−1)!.
Key properties:
A plot of the much more size-constrained nature of the eigenvalues of fn(t) which are not characterized by these two dominant zeros of the polynomial seems to be remarkable as evidenced by the only 20 remaining complex zeros shown below. The next image is reproduced from a freely available article cited above when 10 6 is available here for reference.
Applications and generalizations:
We provide a few examples of the utility of the Redheffer matrices interpreted as a (0,1) matrix whose parity corresponds to inclusion in an increasing sequence of index sets. These examples should serve to freshen up some of the at times dated historical perspective of these matrices, and their being footnote-worthy by virtue of an inherent, and deep, relation of their determinants to the Mertens function and equivalent statements of the Riemann Hypothesis. This interpretation is a great deal more combinatorial in construction than typical treatments of the special Redheffer matrix determinants. Nonetheless, this combinatorial twist on enumerating special sequences of sums has been explored more recently in a number of papers and is a topic of active interest in pre-print archives. Before diving into the full construction of this spin on the Redheffer matrix variants Rn defined above, observe that this type of expansion is in many ways essentially just another variation of the usage of a Toeplitz matrix to represent truncated power series expressions where the matrix entries are coefficients of the formal variable in the series. Let's explore an application of this particular view of a (0,1) matrix as masking inclusion of summation indices in a finite sum over some fixed function. See the citations to the references and for existing generalizations of the Redheffer matrices in the context of general arithmetic function cases. The inverse matrix terms are referred to a generalized Mobius function within the context of sums of this type in.
Applications and generalizations:
Matrix products expanding Dirichlet convolutions and Dirichlet inverses First, given any two non-identically-zero arithmetic functions f and g, we can provide explicit matrix representations which encode their Dirichlet convolution in rows indexed by natural numbers n≥1,1≤n≤x := [Md(n)f(d)g(n/d)]1≤d,n≤x=[00⋯0g(x)00⋯g(x−1)g(x)……⋱⋱⋯g(1)g(2)⋯g(x−1)g(x)][00⋯0f(1)00⋯f(2)f(1)……⋱⋱⋯f(x)f(x−1)⋯f(2)f(1)]RxT.
Then letting := [1,1,…,1] denote the vector of all ones, it is easily seen that the nth row of the matrix-vector product eT⋅Df,g(x) gives the convolved Dirichlet sums (f∗g)(n)=∑d|nf(d)g(n/d), for all 1≤n≤x where the upper index x≥2 is arbitrary.
One task that is particularly onerous given an arbitrary function f is to determine its Dirichlet inverse exactly without resorting to a standard recursive definition of this function via yet another convolved divisor sum involving the same function f with its under-specified inverse to be determined: where := 1/f(1).
Applications and generalizations:
It is clear that in general the Dirichlet inverse f−1(n) for f, i.e., the uniquely defined arithmetic function such that (f−1∗f)(n)=δn,1 , involves sums of nested divisor sums of depth from one to ω(n) where this upper bound is the prime omega function which counts the number of distinct prime factors of n. As this example shows, we can formulate an alternate way to construct the Dirichlet inverse function values via matrix inversion with our variant Redheffer matrices, Rn Generalizations of the Redheffer matrix forms: GCD sums and other matrices whose entries denote inclusion in special sets There are several often cited articles from worthy journals that fight to establish expansions of number theoretic divisor sums, convolutions, and Dirichlet series (to name a few) through matrix representations. Besides non-trivial estimates on the corresponding spectrum and eigenspaces associated with truly notable and important applications of these representations—the underlying machinery in representing sums of these forms by matrix products is to effectively define a so-termed masking matrix whose zero-or-one valued entries denote inclusion in an increasing sequence of sets of the natural numbers {1,2,…,n} . To illustrate that the previous mouthful of jargon makes good sense in setting up a matrix based system for representing a wide range of special summations, consider the following construction: Let An⊆[1,n]∩Z be a sequence of index sets, and for any fixed arithmetic function f:N⟶C define the sums := ∑k∈Anf(k).
Applications and generalizations:
One of the classes of sums considered by Mousavi and Schmidt (2017) defines the relatively prime divisor sums by setting the index sets in the last definition to be := gcd (d,n)=1}.
This class of sums can be used to express important special arithmetic functions of number theoretic interest, including Euler's phi function (where classically we define := 0 ) as φ(n)=∑d∈Gndm, and even the Mobius function through its representation as a discrete (finite) Fourier transform: gcd (k,n)=11≤k≤ne2πikn.
Applications and generalizations:
Citations in the full paper provide other examples of this class of sums including applications to cyclotomic polynomials (and their logarithms). The referenced article by Mousavi and Schmidt (2017) develops a factorization-theorem-like treatment to expanding these sums which is an analog to the Lambert series factorization results given in the previous section above. The associated matrices and their inverses for this definition of the index sets An then allow us to perform the analog of Moebius inversion for divisor sums which can be used to express the summand functions f as a quasi-convolved sum over the inverse matrix entries and the left-hand-side special functions, such as φ(n) or μ(n) pointed out in the last pair of examples. These inverse matrices have many curious properties (and a good reference pulling together a summary of all of them is currently lacking) which are best intimated and conveyed to new readers by inspection. With this in mind, consider the case of the upper index := 21 and the relevant matrices defined for this case given as follows: (1000000000000000000011000000000000000000101000000000000000001111000000000000000010001000000000000000111111000000000000001010101000000000000011011011000000000000101000101000000000001111111111000000000010001010001000000000111111111111000000001010100010101000000011010011001011000000101010101010101000001111111111111111000010001010001010001000111111111111111111001010001010101000101011011001011010011011)−1=(10000000000000000000−11000000000000000000−101000000000000000001−1−110000000000000000−10001000000000000000100−1−110000000000000010−10−1010000000000000−102−100−11000000000000−100010−1010000000000010−110−11−1−110000000000−101000−1000100000000010−1000100−1−110000000030−20−2020−10−1010000000−301030−1−11000−11000000−101010−100000−101000001000−2001001−11−1−110000−302020−201000−1000100030−20−2020−1000100−1−110010−100010−10000000−1010−100−1110−12−1−11−111−100−11) Examples of invertible matrices which define other special sums with non-standard, however, clear applications should be catalogued and listed in this generalizations section for completeness. An existing summary of inversion relations, and in particular, exact criteria under which sums of these forms can be inverted and related is found in many references on orthogonal polynomials. Other good examples of this type of factorization treatment to inverting relations between sums over sufficiently invertible, or well enough behaved triangular sets of weight coefficients include the Mobius inversion formula, the binomial transform, and the Stirling transform, among others.
External links and citations to related work:
Weisstein, Eric W. "Redheffer matrix". MathWorld.
Cardinal, Jean-Paul. "Symmetric matrices related to the Mertens function". Retrieved 12 December 2018.
Kline, Jeffery (2020). "On the eigenstructure of sparse matrices related to the prime number theorem". Linear Algebra and Its Applications. 584: 409–430. doi:10.1016/j.laa.2019.09.022. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Plafond**
Plafond:
A plafond (French for "ceiling"), in a broad sense, is a (flat, vaulted or dome) ceiling.
A plafond can be a product of monumental painting or sculpture. Picturesque plafonds can be painted directly on plaster (as a fresco, oil, glutinous, synthetic paints), on a canvas attached to a ceiling (panel), or a mosaic.
As a decorative feature of churches and staterooms, plafonds were popular from the 17th century until the beginning of the 19th century. Designs of this period typically used illusionistic ceiling painting showing the architectural structure behind, strongly foreshortened figures, architectural details, and/or the open sky. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Tetratricopeptide repeat protein 39C**
Tetratricopeptide repeat protein 39C:
Tetratricopeptide repeat protein 39C is a protein that in humans is encoded by the TTC39C gene. TTC39C is one of three TTC39. Its function is currently unknown; however, there is some evidence suggesting that it plays a role in anaphase. It also contains a relatively well-characterized structural motif called the tetratricopeptide repeat (TPR).
Gene:
TTC39C is located on the long arm of human chromosome 18 at 18q11.2. Its most common aliases are FLJ33761, C18orf17, and HsT2697.
Protein:
The TTC39C protein is 583 amino acids long, and appears to be localized to the cytoplasm of the cell based on its predicted secondary structure It has three isoforms, the longest of which is transcript variant 1. It contains three tetratricopeptide repeats, as well as the domain of unknown function DUF3808. The protein product has a molecular weight of 65.9 kDa and an isoelectric point of 6.584. There are several predicted phosphorylation, acetylation, and palmitoylation sites, which are shown in the table below. Its whole predicted secondary structure is composed almost entirely of helices, and forms a tertiary structure that is predicted to match the structure of the cut9 protein in yeast with 100% accuracy and 85% coverage.
Homology:
The TTC39C protein is over 50% conserved in most vertebrates, and has conservation levels as low as about 24% in invertebrates. At least one ortholog and several homologs have also been identified in fungi. No orthologs have been identified in plants. Several of its orthologs are shown in the table below.
TTC39C has two paralogs from the TTC39 family: TTC39A, and TTC39B, which are located on chromosome 1, at 1p32.3 and chromosome 9, at 9p22.3 respectively. TTC39B has been associated with the management of HDL cholesterol, and may be involved in the prevention of cardiovascular disease
Expression:
The promoter region controlling expression of transcript variant 1 begins approximately 952 bases upstream of the start codon, and includes the entire 5' UTR. Several possible transcription factor binding sites have been identified using the program El Dorado including the CCCTC binding factor and a site for CTCF, an insulator protein that binds CCCTC. This transcription factor is associated with a number of functions including organization of chromatin. There were also several sites that appear to be the general transcription factor TFIIB, and both E2F and E2F transcription factor binding sites. The E2F transcription factors are involved in mediating the cell cycle, which could be a potential link to the hypothesized role of TTC39C in anaphase. Several microarray studies of humans, dogs and mice have provided evidence that TTC39C is most highly expressed in the liver. It exhibits relatively high expression in all tissues, and had a percentile rank above 50% in all tissues except in kidney, spinal cord, and skeletal muscle samples of humans.
Function:
The function of TTC39C is currently unknown. However, one of its structural motifs, the tetratricopeptide repeat is relatively well characterized, and has been shown to be active primarily in four categories of protein-protein interactions: interacting with molecular chaperones, mediating the start of anaphase during cell division, transcription repression, and the transport of proteins. Of these four areas of functionality, the most evidence exists for its involvement in the initiation of anaphase. Two of the three possible interacting proteins identified by STRING play a role in anaphase. Finally, the protein that had a structure that appears to perfectly match 85% of the TTC39C sequence is involved in anaphase in the yeast, Schizosaccharomyces pombe. However, the role of TTC39C in anaphase must be confirmed through additional studies.
Interactions:
Textmining studies have identified several proteins that TTC39C may interact with. These protein-protein interactions have not been confirmed; however, two of the identified proteins, AGBL1 and HAUS4, are likely candidates due to their roles in anaphase. Additional potential protein-protein interactions were identified for TTC39C in mice; however, there is no apparent connection to TTC39C besides coexpression. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Front-runner**
Front-runner:
In politics, a front-runner (also spelled frontrunner or front runner) is a leader in an electoral race. While the front-runner in athletic events (the namesake of the political concept) is generally clear, a political front-runner, particularly in the presidential primary process, is less so as a potential nominee may lead in the polls, have the most name recognition, the most funds raised, or a combination of these. The front-runner is most often declared by the media who are following the race and is written about in a different style than his or her challengers.
Etymology:
The word front-runner originated in the United States. The term emerged from foot racing. It was used by 1914. According to Merriam-Webster the term meant "a contestant who runs best when in the lead" by that time. However the Dictionary of American Slang says it meant "the leader in a contest, election, etc." by that year.The adjective front-running was used by 1940. It also originated from racing. The meaning of the word was analogous to its nounal counterpart at that time. The term was used as a noun by 1970 in the United States to mean "support given to a person or team only when they are doing well." By the 1980s a new definition for front-running emerged from the commodities market in which the word was also used as a noun. The definition was used to describe "a type of fraud in which a trader withholds a large customer order so that he can personally profit from its effect on the market."The intransitive verb front-run emerged by 1950. It originated from a back formation of front-runner. By that year it had a meaning that was analogous to its nounal counterpart.The related word frontrunneritis was used by 1995. It is a combination of frontrunner and –itis, a suffix frequently used informally to describe a tendency or mood that is comparable to a disease. The term was used by that time to describe "the condition of being a leading candidate." In particular it was used to characterize "a tendency to coast or to be under increased scrutiny by the press."
Performance:
American author, columnist, journalist and presidential speechwriter William Safire describes the front-runner as being able to leave "the starting gate well" and set the pace for the other contestants. He uses the racing term "shows early foot" to characterize this tendency. Safire says occasionally the front-runner's lead becomes "insurmountable." He cites Barry Goldwater's successful 1964 Republican presidential nomination and Jimmy Carter's success in several convention states and early primaries in his 1976 presidential campaign as examples.However Safire says the modern usage of the word front-runner has "ominous overtones" of being likely to eventually lose. As an example he references Franklin D. Roosevelt's receiving a letter from Robert W. Woolley about Roosevelt's front-runner status early in his 1932 presidential campaign: "Herein lies the danger ... automatically you become the target of the other candidates, real and potential. There isn't a single favorite son whose delegation won't be held out of the Roosevelt column so long as there is a reasonable chance of getting something for that favorite son, even at your expense." Safire gives another example when he quotes Ted Sorensen's thoughts about John F. Kennedy's front-runner status during his 1960 presidential campaign: "There were disadvantages in being the 'front runner.' The Senator's critics became more open and vocal and his every word was politically interpreted."The outcome of the second round of primaries is critical to a front-runner's success. Safire argues that the front-runner "must come thundering into the convention increasing his speed and with enough 'kick' left for a final spurt" to be successful. He quotes Thomas E. Dewey writing about his losing the 1940 Republican presidential nomination as an example: "When the balloting starts, every candidate wants to show enough strength to be one of the leaders on the first ballot. He also wants to have enough strength in reserve so he can gain on the psychologically important second ballot. For example, in 1940, I led on the first three ballots out of six—the wrong three. I lost ground on the second ballot. That was the beginning of the end and everybody knew it."Safire states that front-runners often take advantage of the bandwagon effect by emphasizing their "inevitability factor." He says this is done by suggesting the futility of the front-runner's opponents. However Safire notes that a front-runner's "inevitability" can be vulnerable to their opponents. Safire cites the example of George W. Bush's front-runner status in the 2000 Republican primary being threatened by John McCain's victory in the New Hampshire primary. Another example he notes is Gary Hart's upset win in the New Hampshire primary, which challenged Walter Mondale's front-runner status in the 1984 Democratic primary. Safire quotes Peter Hart, a pollster "who advised" Walter Mondale, commenting on the 1984 race in 2007: "Inevitability is not a message ... there needs to be something to grab on to. Inevitability is not a tune that people can march to." Safire also cites journalist Adam Gourney's thoughts: "[N]othing invites a teardown more than being perceived as the front-runner. Being on top makes you a big target for your opponents and the news media, and sets you up for buyer's remorse, a common phenomenon in the nomination process, even before the sale is done."Safire says that despite the risks in being the front-runner, candidates prefer it over being a dark horse or a long shot because that position has a higher chance of winning. Front-runners often have a financial advantage over dark horses.
Performance:
Early front-runners David Greenberg, associate professor of History and of Journalism and Media Studies at Rutgers University, states that front-runners decided by early polls often do not win the nomination. Greenberg notes that early polls decided Birch Bayh in the 1976 Democratic primary, Ted Kennedy in the 1980 Democratic primary, Jesse Jackson in the 1988 Democratic primary, Jerry Brown in the 1992 Democratic primary, Howard Dean in the 2004 Democratic primary and Herman Cain in the 2012 Republican primary as front-runners, all of whom lost the nomination.Greenberg suggests that the futility of most early front-runners reflects early polls' unreliability and in particular, their respondents' indifference to the candidates. He notes that indifference is especially justified for electorates whose state primary runs during the later stages of the race. He cites David Karol, a political scientist, who says that "[t]he media don't always report the numbers that say 'not sure' or 'don't know enough.'"Greenberg states that the rise of early front-runners is partly due to name recognition. He cites the early lead of Donald Trump in the 2016 Republican primary, Joe Lieberman in the 2004 Democratic primary and George W. Bush in the 2000 Republican primary as examples of this. He further states that early front-runners are established in part due to recent media attention, and notes that Jonathan Bernstein, a political scientist and columnist, shares this view. Greenberg cites the early front-runners Donald Trump in the 2016 Republican primary, Gary Hart in the 1984 Democratic primary and Howard Dean in the 2004 Democratic primary as examples of this.Greenberg acknowledges that some front-runners decided by early polls win the nomination. He states that this often occurs "in races with few competitors." He notes Al Gore’s early lead in 1999 before winning the 2000 Democratic presidential nomination as an example. Greenberg states that early front-runners can also win if they are an "overwhelming favorite" in the race. He gives Ronald Reagan’s early front-runner status in 1979 before winning the 1980 Republican presidential nomination as an example. Greenberg notes that William Mayer, a political scientist at Northeastern University, discovered that in contested primary races since 1980, of the eight front-runners who polled at 34 percent or higher in the September before the election, six won the nomination, and none of the five front-runners who polled below that percentage won.
Performance:
Debates Primary debate participation may hinder a front-runner's chance to be nominated.Debate analysts and scholars recognize that the front-runner is often attacked more frequently by the other candidates. It is a common strategy of the front-runner's opponents, especially for long shot candidates. During the December 2, 1999 Republican primary debate, almost all attacks were directed against the front-runner George W. Bush. Long shot candidates Gary Bauer, Orrin Hatch and Alan Keyes significantly contributed to the mass attack. In a debate featuring the 1988 Democratic primary candidates, long shot candidates "gang[ed] up" on the front-runner. Analysis on a 1992 primary debate showed that the front-runner received the most attacks.However, excessively attacking the front-runner can hurt one's image and support from viewers. In the December 2, 1999 Republican primary debate, all 10 of Steve Forbes' attacks were made against George W. Bush, contributing to over half of the total attacks that targeted Bush. Steve Forbes experienced a negative effect on his image and lost all support he had from a sample of 91 viewers before the debate. Although reasons other than excessive attacking may have contributed to Forbes' decline, viewers had "a clear negative reaction to his constant attack of Bush." John McCain, who made no attacks, had his image improved and his support from the viewers increased. This suggests that a front-runner's opponent may be more successful if they "attack in moderation." It may also suggest that if the opponent is recognized by viewers as a "legitimate contender," they can benefit from refraining from attacks and "permitting the larger field of [long shot candidates] to do the dirty work of attacking a front-runner." This would allow the opponent to project "a more positive message" about their ideas. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Sinopharm CNBG COVID-19 vaccine**
Sinopharm CNBG COVID-19 vaccine:
Sinopharm NVSI COVID-19 vaccine, also known as mutI-tri-RBD or NVSI-06-08, is a COVID-19 vaccine developed by National Vaccine & Serum Institute (NVSI, 中生研究院), a subsidiary of CNBG of Sinopharm.They claim to be the world's first "second generation broadly protective" recombination protein subunit vaccine, i.e. by combining three heterogeneous antigens into one single trimer RBD protein (突变集成三聚化RBD, mutI-tri-RBD). It's based on the original, and the Beta (K417N/E484K/N501Y) and Kappa (L452R/E484K) variants. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Vinculum (ligament)**
Vinculum (ligament):
In anatomy, a vinculum (pl. vincula) is a band of connective tissue, similar to a ligament, that connects a flexor tendon to a phalanx bone. They contain tiny vessels which supply blood to the tendon.
In vertebrate anatomy, they are referred to as mesotendons.
Vinculum (ligament):
For example, in the fingers and toes of humans and related vertebrates, vincula are responsible for the direct vascularization of the flexor digitorum superficialis and profundus tendons to the intermediate and distal phalanges in each finger. These vincula are four folds in the synovial membrane that carry blood vessels to the body and insertion of the tendon. The tendon receives some additional nutrition directly from the synovial fluid in the sheath, which is important in case of partial loss of direct vascularization from the vincula.In the chick, vincula are much larger and more complex than in humans. Though they contain blood vessels, these only make up a very limited portion of the total mass of the vincula, most of which consists of collagen and elastic fibres.A vinculum is also found in insects' male genitalia. Unlike the vertebrate structures, it is part of the exoskeleton, being formed by the ventral part of the ninth abdominal segment. It retains the aedeagus and the clasper attaches to it. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Spermidine**
Spermidine:
Spermidine is a polyamine compound (C7H19N3) found in ribosomes and living tissues and having various metabolic functions within organisms. It was originally isolated from semen.
Function:
Spermidine is an aliphatic polyamine. Spermidine synthase (SPDS) catalyzes its formation from putrescine. It is a precursor to other polyamines, such as spermine and its structural isomer thermospermine.
Function:
Spermidine synchronizes an array of biological processes, (such as Ca2+, Na+, K+ -ATPase) thus maintaining membrane potential and controlling intracellular pH and volume. Spermidine regulates biological processes, such as Ca2+ influx by glutamatergic N-methyl-d-aspartate receptor (NMDA receptor), which has been associated with nitric oxide synthase (NOS) and cGMP/PKG pathway activation and a decrease of Na+,K+-ATPase activity in cerebral cortex synaptosomes.
Function:
Spermidine is a longevity agent in mammals due to various mechanisms of action, which are just beginning to be understood. Autophagy is the main mechanism at the molecular level, but evidence has been found for other mechanisms, including inflammation reduction, lipid metabolism, and regulation of cell growth, proliferation, and death.Spermidine is known to regulate plant growth, assisting the in vitro process of transcribing RNA, and inhibition of NOS. Also, spermidine is a precursor to other polyamines, such as spermine and thermospermine, some of which contribute to tolerance against drought and salinity in plants.
Function:
Spermidine has been tested and discovered to encourage hair shaft elongation and lengthen hair growth. Spermidine has also been found to “upregulate expression of the epithelial stem cell-associated keratins K15 and K19, and dose-dependently modulated K15 promoter activity in situ and the colony forming efficiency, proliferation and K15 expression of isolated human K15-GFP+ cells in vitro.”
Biochemical actions:
Spermidine's known actions include: Inhibits neuronal nitric oxide synthase (nNOS) Binds and precipitates DNA Polyamine plant growth regulator
Sources:
Good dietary sources of spermidine are aged cheese, mushrooms, soy products, legumes, corn, and whole grains. Spermidine is plentiful in a Mediterranean diet.
For comparison: The spermidine content in human seminal plasma varies between approx. 15 and 50 mg/L (mean 31 mg/L).
Note - spermidine content varies by source and age. See ref for details.
In grains, the endosperm contains most of the spermidine. One of the best known grain dietary sources is wheat germ, containing as much as 243 mg/kg.
Uses:
Spermidine can be used in electroporation while transferring the DNA into the cell under the electrical impulse. May be used for purification of DNA-binding proteins.
Spermidine is also used, along with calcium chloride, for precipitating DNA onto microprojectiles for bombardment with a gene gun.
Spermidine has also been reported to protect the heart from aging and prolong the lifespan of mice, while in humans it was correlated with lower blood pressure. It also was found to reduce the amount of aging in yeast, flies, worms, and human immune cells by inducing autophagy.
Spermidine may play a role in male and female fertility. Fertile men have higher spermidine levels than men who are infertile, and spermidine supplementation has been shown to help maintain a healthy hormone balance and reduce oxidative stress.
Spermidine is commonly used for in vitro molecular biology reactions, particularly, in vitro transcription by phage RNA polymerases, in vitro transcription by human RNA polymerase II, and in vitro translation.
Spermidine increases specificity and reproducibility of Taq-mediated PCR by neutralizing and stabilizing the negative charge on DNA phosphate backbone.
Spermidine is, at physiological pH, a polycationic reagent that aids in enzyme digestion by forcing apart DNA molecules. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Optical margin alignment**
Optical margin alignment:
Optical margin alignment outdents letters like A, V, W, Y, and punctuation into the margins to align the text border optically. Some users remark that it makes the text margin look crooked, but this is because text frames or margin guides are visible. If text frames are not visible, e.g. in print preview, or when printed, the edge of a block of text looks more even if optical margin alignment is enabled.
Optical margin alignment:
From the earliest days of machine printing, punctuation and Drop Capitals were indented slightly into the margin, as can be seen in the pages of the Gutenberg Bible in the British Library. Word-processing software lacks this attention to detail that could be achieved when manually setting type page by page, but professional page layout software like InDesign, Ventura and Serif PagePlus can now achieve this with a fine level of adjustment over which letters to indent into the margin and by how much.
Use:
Optical margin alignment is designed to be used for body text, and not for display type, text in tables, or headlines.
Use:
It is often used for block quotes, which benefit from “hung punctuation.” In such cases, the leading quotation mark is outdented 100% into the margin or paragraph indent, so that subsequent lines of text align with the first character in the quotation. If the first character of the quotation is meant to be styled as a drop cap, then both the opening, hung quotation mark and the following letter are styled as such.
Use:
The optimal values used for the outdents is font-dependent. A typeface whose capital A, V, W, and Y have vertical sides needs no outdents for these letters, but the capital T and punctuation will still benefit from the use of optical margin alignment.
If text has narrow gutters between columns, table borders, or any straight edge such as an image near to the edge of the text, optical margin alignment should not be used because the proximity of the straight line will break the optical illusion.
This technique is related to and sometimes equated with hanging punctuation, though optical margin alignment is not limited to adjusting only punctuation.
Suggested values for optical justification These values may be suitable for common seriffed fonts like Times New Roman, Palatino, or Garamond. Other fonts may need different values. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Cortana (virtual assistant)**
Cortana (virtual assistant):
Cortana is a virtual assistant developed by Microsoft, that uses the Bing search engine to perform tasks such as setting reminders and answering questions for the user.
Cortana (virtual assistant):
Cortana is currently available in English, Portuguese, French, German, Italian, Spanish, Chinese, and Japanese language editions, depending on the software platform and region in which it is used.Microsoft began reducing the prevalence of Cortana and converting it from an assistant into different software integrations in 2019. It was split from the Windows 10 search bar in April 2019. In January 2020, the Cortana mobile app was removed from certain markets, and on March 31, 2021, the Cortana mobile app was shut down globally. On June 2, 2023, Microsoft announced that support for the Cortana standalone app on Microsoft Windows will end in late 2023 and would be replaced by Windows Copilot and Bing Chat AI.
History:
Cortana was demonstrated for the first time at the Microsoft Build developer conference in San Francisco in April 2014. It was launched as a key ingredient of Microsoft's planned "makeover" of future operating systems for Windows Phone and Windows.It is named after Cortana, a synthetic intelligence character in Microsoft's Halo video game franchise originating in Bungie folklore, with Jen Taylor, the character's voice actress, returning to voice the personal assistant's US-specific version.
History:
Development The development of Cortana started in 2009 in the Microsoft Speech products team with general manager Zig Serafin and Chief Scientist Larry Heck. Heck and Serafin established the vision, mission, and long-range plan for Microsoft's digital personal assistant and they built a team with the expertise to create the initial prototypes for Cortana. Some of the key researchers in these early efforts included Microsoft Research researchers Dilek Hakkani-Tür, Gokhan Tur, Andreas Stolcke, and Malcolm Slaney, research software developer Madhu Chinthakunta, and user experience designer Lisa Stifelman. To develop the Cortana digital assistant, the team interviewed human personal assistants. The interviews inspired a number of unique features in Cortana, including the assistant's "notebook" feature. Originally, Cortana was meant to be only a codename, but a petition on Windows Phone's UserVoice site proved to be popular and made the codename official.
History:
Expansion to other platforms In January 2015, Microsoft announced the availability of Cortana for Windows 10 desktops and mobile devices as part of merging Windows Phone into the operating system at large.
History:
On May 26, 2015, Microsoft announced that Cortana would also be available on other mobile platforms. An Android release was set for July 2015, but the Android APK file containing Cortana was leaked ahead of its release. It was officially released, along with an iOS version, in December 2015.During E3 2015, Microsoft announced that Cortana would come to the Xbox One as part of a universally designed Windows 10 update for the console.
History:
New focus In 2017, Microsoft partnered with Amazon to integrate Echo and Cortana with each other, allowing users of each smart assistant to summon the other via a command. This feature preview was released in August 2018. Windows 10 users can just say "Hey Cortana, open Alexa" and Echo users can say "Alexa, open Cortana" to summon the other assistant.In January 2019, Microsoft CEO Satya Nadella stated that he no longer sees Cortana as a direct competitor against Alexa and Siri.
History:
Decreasing focus on Cortana and discontinuation On July 24, 2020, Cortana was removed from the Xbox dashboard as part of a redesign, then on January 31, 2021, Microsoft removed the Cortana mobile application in certain markets (including UK, Australia, Germany, Mexico, China, Spain, Canada, and India).On March 31, 2021, Microsoft shut down the Cortana apps entirely for iOS and Android and removed them from corresponding app stores. To access previously recorded content, users have to use Cortana on Windows 10 or another specialized Microsoft application.Microsoft has also reduced emphasis on Cortana in Windows 11. Cortana is not used during the new device setup process and isn't pinned to the taskbar by default.On June 2, 2023, Microsoft announced that they would shut down the Cortana standalone app on Windows 10 and Windows 11 later in the year. This is because of more powerful productivity and increased AI capabilities tools in Windows and Edge. Microsoft lists several alternatives such as Bing Chat AI and Windows Copilot (coming later in June). They also stressed that the change wouldn't impact Cortana in Office 365 and Teams environments.On August 11, 2023, Microsoft updated the Cortana app in Windows, announcing it is deprecated and can no longer be used. The Cortana End of Support article was updated to reflect this change. Along with the standalone app being deprecated, it was announced in the End of Support article that Cortana support in Teams mobile, Microsoft Teams displays, and Teams rooms will end in Fall 2023. The support article states that Cortana in Outlook mobile will continue to be available.
Cortana in other services:
Microsoft has integrated Cortana into numerous products such as Microsoft Edge, the browser bundled with Windows 10. Microsoft's Cortana assistant is deeply integrated into its Edge browser. Cortana can find opening hours when on restaurant sites, show retail coupons for websites, or show weather information in the address bar. At the Worldwide Partners Conference 2015 Microsoft demonstrated Cortana integration with products such as GigJam. Conversely, Microsoft announced in late April 2016 that it would block anything other than Bing and Edge from being used to complete Cortana searches, again raising questions of anti-competitive practices by the company.Microsoft's "Windows in the car" concept includes Cortana. The concept makes it possible for drivers to make restaurant reservations and see places before they go there.At Microsoft Build 2016, Microsoft announced plans to integrate Cortana into Skype (Microsoft's video-conferencing and instant messaging service) as a bot to allow users to order food, book trips, transcribe video messages and make calendar appointments through Cortana in addition to other bots. As of 2016, Cortana can underline certain words and phrases in Skype conversations that relate to contacts and corporations. A writer from Engadget has criticised the Cortana integration in Skype for responding only to very specific keywords, feeling as if she was "chatting with a search engine" due to the impersonal way the bots replied to certain words such as "Hello" causing the Bing Music bot to bring up Adele's song of that name.Microsoft also announced at Microsoft Build 2016 that Cortana would be able to cloud-synchronise notifications between Windows 10 Mobile's and Windows 10's Action Center, as well as notifications from Android devices.In December 2016, Microsoft announced the preview of Calendar.help, a service that enabled people to delegate the scheduling of meetings to Cortana. Users interact with Cortana by including her in email conversations. Cortana would then check people's availability in Outlook Calendar or Google Calendar, and work with others Cc'd on the email to schedule the meeting. The service relied on automation and human-based computation.In May 2017, Microsoft in collaboration with Harman Kardon announced INVOKE, a voice-activated speaker featuring Cortana. The premium speaker has a cylindrical design and offers 360-degree sound, the ability to make and receive calls with Skype, and all of the other features currently available with Cortana.
Functionality:
Cortana can set reminders, recognize natural voice without the requirement for keyboard input, and answer questions using information from the Bing search engine (For example, current weather and traffic conditions, sports scores, biographies). Searches using Windows 10 are made only with the Microsoft Bing search engine, and all links will open with Microsoft Edge, except when a screen reader such as Narrator is being used, where the links will open in Internet Explorer. Windows Phone 8.1's universal Bing SmartSearch features are incorporated into Cortana, which replaces the previous Bing Search app, which was activated when a user presses the "Search" button on their device. Cortana includes a music recognition service. Cortana can simulate rolling dice and flipping a coin. Cortana's "Concert Watch" monitors Bing searches to determine the bands or musicians that interest the user. It integrates with the Microsoft Band watch band for Windows Phone devices if connected via Bluetooth, it can make reminders and phone notifications.Since the Lumia Denim mobile phone series, launched in October 2014, active listening was added to Cortana enabling it to be invoked with the phrase: "Hey Cortana". It can then be controlled as usual. Some devices from the United Kingdom by O2 received the Lumia Denim update without the feature, but this was later clarified as a bug and Microsoft has since fixed it.Cortana integrates with services such as Foursquare to provide restaurant and local attraction recommendations and LIFX to control smart light bulbs.
Functionality:
Notebook Cortana stores personal information such as interests, location data, reminders, and contacts in the "Notebook". It can draw upon and add to this data to learn a user's specific patterns and behaviors. Users can view and specify what information is collected to allow some control over privacy, said to be "a level of control that goes beyond comparable assistants". Users can delete information from the "Notebook".
Functionality:
Reminders Cortana has a built-in system of reminders, which can, for example, be associated with a specific contact; it will then remind the user when in communication with that contact, possibly at a specific time or when the phone is in a specific location. Originally, these reminders were specific to the device Cortana was installed on but starting on February 12, 2015, Cortana synchronizes reminders across devices.
Functionality:
Design Most versions of Cortana take the form of two nested circles, which are animated to indicate activities such as searching or talking. The main color scheme includes a black or white background and shades of blue for the respective circles.
Phone notification syncing Cortana on Windows mobile and Android is capable of capturing device notifications and sending them to a Windows 10 device. This allows a computer user to view notifications from their phone in the Windows 10 Action Center. The feature was announced in early 2016 and released later in the year.
Functionality:
Miscellaneous Cortana has a "do-not-disturb" mode in which users can specify "quiet hours", as was available for Windows Phone 8.1 users. Users can change the settings so that Cortana calls users by their names or nicknames. It also has a library of "Easter Eggs", pre-determined remarks.When asked for a prediction, Cortana correctly predicted the winners of the first 14 matches of the football 2014 FIFA World Cup knockout stage, including the semi-finals, before it incorrectly picked Brazil over the Netherlands in the third place play-off match; this streak topped Paul the Octopus who correctly predicted all 7 of Germany's 2010 FIFA World Cup matches as well as the Final. Cortana can forecast results in various other sports such as the NBA, the NFL, the Super Bowl, the ICC Cricket World Cup and various European football leagues. Cortana can solve mathematical equations, convert units of measurement, and determine the exchange rates between currencies including Bitcoin.
Integrations:
Cortana can integrate with third-party apps on Windows 10 or directly through the service. Starting in late 2016, Cortana integrated with Microsoft's Wunderlist service, allowing Cortana to add and act on reminders.At Microsoft's Build 2017 conference, Microsoft announced that Cortana would get a consumer third-party skills capability, similar to that in Amazon Alexa.On February 16, 2018, Microsoft announced connected home skills were added for ecobee, Honeywell Lyric, Honeywell Total Connect Comfort, LIFX, TP-Link Kasa, and Geeni, as well as support for IFTTT. At Microsoft's Ignite 2018 conference, Microsoft announced an Technology Adopters Program that Enterprises could build skills that could be developed and deployed into Azure tenants, accessible by organizational units or security groups.
Privacy concerns:
Cortana indexes and stores user information. Cortana can be disabled; this will cause Windows search to search Bing as well as the local computer, but that can also be disabled. Turning Cortana off does not in itself delete user data stored on Microsoft's servers, but it can be deleted by user action. Microsoft has further been criticized for requests to Bing's website for a file called "threshold.appcache", which contains Cortana's information through searches made through the Start Menu even when Cortana is disabled on Windows 10.As of April 2014, Cortana was disabled for users aged under 13 years.
Regions and languages:
The British version of Cortana speaks with a British accent and uses British idioms, while the Chinese version, known as Xiao Na, speaks Mandarin Chinese and has an icon featuring a face and two eyes, which is not used in other regions.As of 2020 the English version of Cortana on Windows devices is available to all users in the United States (American English), Canada (French/English), Australia, India, and the United Kingdom (British English). Other language versions of Cortana are available in France (French), China (Simplified Chinese), Japan (Japanese), Germany (German), Italy (Italian), Brazil (Portuguese), Mexico, and Spain (Spanish). Cortana listens generally to the hot word "Hey Cortana" in addition to certain languages' customized versions, such as "Hola Cortana" in Spanish.The English United Kingdom localised version of Cortana is voiced by voice actress Ginnie Watson, while the United States localised version is voiced by Jen Taylor. Taylor is the voice actress who voices Cortana, the namesake of the virtual assistant, in the Halo video game series.The following table identifies the localized version of Cortana currently available. Except where indicated, this applies to both Windows Mobile and Windows 10 versions of the assistant.
Technology:
The natural language processing capabilities of Cortana are derived from Tellme Networks (bought by Microsoft in 2007) and are coupled with a Semantic search database called Satori.While many of Cortana's U.S. English responses are voiced by Jen Taylor, organic responses require the use of a text-to-speech engine. Microsoft Eva is the name of the text-to-speech voice for organic response in Cortana's U.S. English.
Updating:
Cortana updates were delivered independently of those to the main Windows Phone OS, allowing Microsoft to provide new features at a faster pace. Not all Cortana-related features could be updated in this manner, as some features such as "Hey Cortana" required the Windows Phone update service and the Qualcomm Snapdragon SensorCore Technology. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Analysis of Functional NeuroImages**
Analysis of Functional NeuroImages:
Analysis of Functional NeuroImages (AFNI) is an open-source environment for processing and displaying functional MRI data—a technique for mapping human brain activity.
AFNI is an agglomeration of programs that can be used interactively or flexibly assembled for batch processing using shell script. The term AFNI refers both to the entire suite and to a particular interactive program often used for visualization. AFNI is actively developed by the NIMH Scientific and Statistical Computing Core and its capabilities are continually expanding.
Analysis of Functional NeuroImages:
AFNI runs under many Unix-like operating systems that provide X11 and Motif libraries, including IRIX, Solaris, Linux, FreeBSD and OS X. Precompiled binaries are available for some platforms. AFNI is available for research use under the GNU General Public License, the included SVM-light component is non-commercial and non-distributable. AFNI now comprises over 300,000 lines of C source code, and a skilled C programmer can add interactive and batch functions to AFNI with relative ease.
History and development:
AFNI was originally developed at the Medical College of Wisconsin beginning in 1994, largely by Robert W. Cox. Cox brought development to the NIH in 2001 and development continues at the NIMH Scientific and Statistical Computing Core. In a 1995 paper describing the rationale for development of the software, Cox wrote of fMRI data: "The volume of data gathered is very large, and it is essential that easy-to-use tools for visualization and analysis of 3D activation maps be available for neuroscience investigators." Since then, AFNI has become one of the more commonly used analysis tools in fMRI research, alongside SPM and FSL.Although AFNI initially required extensive shell scripting to execute tasks, pre-made batch scripts and improvements to the graphical user interface (GUI) have since made it possible to generate analyses with less user scripting.
Features:
Visualization One of AFNI's initial offerings improved the approach to transforming scans of individual brains onto a shared standardized space. Since each person's individual brain is unique in size and shape, comparing across a number of brains requires warping (rotating, scaling, etc.) individual brains into a standard shape. Unfortunately, functional MRI data at the time of AFNI's development was too low resolution for effective transformations. Instead, researchers use the higher resolution anatomical brain scans, often acquired at the beginning of an imaging session.
Features:
AFNI allows researchers to overlay a functional image to the anatomical, providing tools for aligning the two into the same space. Processes engaged to warp an individual anatomical scan to standard space are then applied also to the functional scan, improving the transformation process.Another feature available in AFNI is the SUMA tool, developed by Ziad Saad. This tool allows users to project the 2D data onto a 3D cortical surface map. In this way researchers can view activation patterns while more easily taking into account physical cortical features like gyri.
Features:
Image Pre-processing "afni_proc.py" is a pre-made script that will run fMRI data from a single subject through a series of pre-processing steps, starting with the raw data. The default settings will perform the following pre-processing steps and finish with a basic regression analysis: Slice timing: Each 3D brain image is composed of multiple 2D images, "slices". Although acquired at approximately the same time, up to several seconds could separate the first slice acquired from the last. Through interpolation, the slices are aligned to the same time point. Generally, any introduced noise from interpolation errors is thought to be outweighed by improvements in signal.
Features:
Motion correction: Head movements can create sources of error in the analysis. Each 3D acquisition in a scan is collected on a 3D grid, with each small cube of grid space, "voxel", representing a single image intensity value. Ideally, voxels will always represent the same part of the brain in each acquisition, rather than vary from one 3D image to the next. To correct small motion artifacts, AFNI's motion correction tool employs a linear least squares algorithm that attempts to align each 3D image acquired to the first image acquired in the scan.
Features:
Smoothing: To account for random noise in the image, a smoothing kernel is applied. While smoothing can increase the signal-to-noise ratio of the image, it reduces image resolution.
Mask: Removes any non-brain areas, such as skull, from the fMRI image.
Scale: Scale each voxel so that changes in intensity represent percentage of signal change over the course of the scan. The default sets the mean of each voxel equal to 100. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
**Milman–Pettis theorem**
Milman–Pettis theorem:
In mathematics, the Milman–Pettis theorem states that every uniformly convex Banach space is reflexive.
The theorem was proved independently by D. Milman (1938) and B. J. Pettis (1939). S. Kakutani gave a different proof in 1939, and John R. Ringrose published a shorter proof in 1959.
Mahlon M. Day (1941) gave examples of reflexive Banach spaces which are not isomorphic to any uniformly convex space. | kaggle.com/datasets/mbanaei/all-paraphs-parsed-expanded |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.