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https://en.wikipedia.org/wiki/Journal%20of%20Virology | The Journal of Virology is a biweekly peer-reviewed scientific journal that covers research concerning all aspects of virology. It was established in 1967 and is published by the American Society for Microbiology. Research papers are available free online four months after print publication.
The current editors-in-chief are Felicia Goodrum (University of Arizona) and Stacey Schultz-Cherry (St. Jude Children's Research Hospital). Past editors-in-chief include Rozanne M. Sandri-Goldin (University of California, Irvine, California) (2012-2022), Lynn W. Enquist (2002–2012), Thomas Shenk (1994–2002), and Arnold J. Levine (1984–1994).
Abstracting and indexing
The journal is abstracted and indexed in AGRICOLA, Biological Abstracts, BIOSIS Previews, Chemical Abstracts, Current Contents, EMBASE, MEDLINE/Index Medicus/PubMed, and the Science Citation Index Expanded. Its 2015 impact factor was 4.606, ranking it fifth out of 33 journals in the category "Virology". |
https://en.wikipedia.org/wiki/Hushmail | Hushmail is an encrypted proprietary web-based email service offering PGP-encrypted e-mail and vanity domain service. Hushmail uses OpenPGP standards. If public encryption keys are available to both recipient and sender (either both are Hushmail users or have uploaded PGP keys to the Hush keyserver), Hushmail can convey authenticated, encrypted messages in both directions. For recipients for whom no public key is available, Hushmail will allow a message to be encrypted by a password (with a password hint) and stored for pickup by the recipient, or the message can be sent in cleartext. In July, 2016, the company launched an iOS app that offers end-to-end encryption and full integration with the webmail settings. The company is located in Vancouver, British Columbia, Canada.
History
Hushmail was founded by Cliff Baltzley in 1999 after he left Ultimate Privacy.
Accounts
Individuals
There is one type of paid account, Hushmail Premium, which provides 10GB of storage, as well as IMAP and POP3 service. Hushmail offers a two-week free trial of this account.
Businesses
The standard business account provides the same features as the paid individual account, plus other features like vanity domain, email forwarding, catch-all email and user admin. A standard business plan with email archiving is also available. Features like secure forms and email archiving can be found in the healthcare and legal industry-specific plans.
Additional security features include hidden IP addresses in e-mail headers, two-step verification and HIPAA compliant encryption.
Instant messaging
An instant messaging service, Hush Messenger, was offered until July 1, 2011.
Compromises to email privacy
Hushmail received favorable reviews in the press. It was believed that possible threats, such as demands from the legal system to reveal the content of traffic through the system, were not imminent in Canada unlike the United States and that if data were to be handed over, encrypted messages would be |
https://en.wikipedia.org/wiki/European%20Physical%20Society | The European Physical Society (EPS) is a non-profit organisation whose purpose is to promote physics and physicists in Europe through methods such as physics outreach. Formally established in 1968, its membership includes the national physical societies of 42 countries, and some 3200 individual members. The Deutsche Physikalische Gesellschaft, the world's largest and oldest organisation of physicists, is a major member.
Conferences
One of its main activities is organizing international conferences.
The EPS sponsors conferences other than the Europhysics Conference, like the International Conference of Physics Students in 2011.
Divisions and groups
The scientific activities of EPS are organised through Divisions and Groups, who organise topical conferences, seminars, and workshops. The Divisions and Groups are governed by boards elected from members. The current Divisions of the EPS are:
Atomic, Molecular and Optical Physics Division
Condensed Matter Division
Environmental Physics Division
Gravitational Physics Division
High Energy Particle Physics Division
Nuclear Physics Division
Division of Physics in Life Sciences
Physics Education Division
Plasma Physics Division
Quantum Electronics and Optics Division
European Solar Physics Division
Statistical & Nonlinear Physics Division
And the current Groups of the EPS are:
Accelerator Group
Computational Physics Group
Energy Group
History of Physics Group
Physics for Development Group
Technology and Innovation Group
Prizes
The EPS awards a number of prizes, including the Edison Volta Prize, the EPS Europhysics Prize, the EPS Statistical and Nonlinear Physics Prizes, the High Energy and Particle Physics Prize and the Rolf Wideroe Prize.
It also recognises sites which are historically important for advances to physics, such as the Blackett Laboratory (UK) in 2014, and the Residencia de Estudiantes (Spain) in 2015.
Publications
Its letters journal is EPL; its other publications include Europhysics Ne |
https://en.wikipedia.org/wiki/Engineering%20drawing | An engineering drawing is a type of technical drawing that is used to convey information about an object. A common use is to specify the geometry necessary for the construction of a component and is called a detail drawing. Usually, a number of drawings are necessary to completely specify even a simple component. The drawings are linked together by a master drawing or assembly drawing which gives the drawing numbers of the subsequent detailed components, quantities required, construction materials and possibly 3D images that can be used to locate individual items. Although mostly consisting of pictographic representations, abbreviations and symbols are used for brevity and additional textual explanations may also be provided to convey the necessary information.
The process of producing engineering drawings is often referred to as technical drawing or drafting (draughting). Drawings typically contain multiple views of a component, although additional scratch views may be added of details for further explanation. Only the information that is a requirement is typically specified. Key information such as dimensions is usually only specified in one place on a drawing, avoiding redundancy and the possibility of inconsistency. Suitable tolerances are given for critical dimensions to allow the component to be manufactured and function. More detailed production drawings may be produced based on the information given in an engineering drawing. Drawings have an information box or title block containing who drew the drawing, who approved it, units of dimensions, meaning of views, the title of the drawing and the drawing number.
History
Technical drawing has existed since ancient times. Complex technical drawings were made in renaissance times, such as the drawings of Leonardo da Vinci. Modern engineering drawing, with its precise conventions of orthographic projection and scale, arose in France at a time when the Industrial Revolution was in its infancy. L. T. C. Rolt's biog |
https://en.wikipedia.org/wiki/African%20Society%20for%20Bioinformatics%20and%20Computational%20Biology | The African Society for Bioinformatics and Computational Biology (ASBCB) is a non-profit professional association dedicated to the advancement of bioinformatics and computational biology in Africa. Transformed from the African Bioinformatics Network (ABioNET), ASBCB was established in February 2004 at a meeting in Cape Town, South Africa. The Society serves as an international forum and resource devoted to developing competence and expertise in bioinformatics and computational biology in Africa. It complements its activities with those of other international and national societies, associations and institutions, public and private, that have similar aims. It also promotes the standing of African bioinformatics and computational biology in the global arena through liaison and cooperation with other international bodies.
It is an affiliated regional group of the International Society for Computational Biology (ISCB).
Vision
The Society sees itself as conduit to promote the exchange of ideas, infrastructure and resources in the fields of bioinformatics and computational biology and facilitate the interaction and collaboration among scientists and educators around the world.
It also strives to measurably advance the awareness and understanding of the science of bioinformatics and computational biology. The society represents the bioinformatics and computational biology community in Africa and will be the most respected and reliable international non-profit organization representing this community.
Mission
Be a scholarly society dedicated to advancing, developing and promoting bioinformatics and computational biology in Africa.
Serve a global membership by impacting government and scientific policies, providing high quality publications and meetings, and through distribution of valuable information about training, education, employment and relevant news from related fields.
Develop the application of bioinformatics in Africa in collaboration with individuals, grou |
https://en.wikipedia.org/wiki/Ensifer%20fredii | Ensifer fredii is a nitrogen fixing bacteria of the genus Sinorhizobium. It is a fast-growing root nodule bacteria. Sinorhizobium fredii exhibit a broad host-range and are able to nodulate both determinant hosts such as soy as well as indeterminate hosts including the pigeon pea. Because of their ease of host infection there is interest in their genetics and the symbiotic role in host infection and nodule formation.
History
This species was first isolated from soybeans. The type strain was isolated from a root nodule of Glycine max growing in Hunan Province, China, designated strain USDA 205 (= ATCC 35423 = PRC 205). |
https://en.wikipedia.org/wiki/Constant%20curvature | In mathematics, constant curvature is a concept from differential geometry. Here, curvature refers to the sectional curvature of a space (more precisely a manifold) and is a single number determining its local geometry. The sectional curvature is said to be constant if it has the same value at every point and for every two-dimensional tangent plane at that point. For example, a sphere is a surface of constant positive curvature.
Classification
The Riemannian manifolds of constant curvature can be classified into the following three cases:
elliptic geometry – constant positive sectional curvature
Euclidean geometry – constant vanishing sectional curvature
hyperbolic geometry – constant negative sectional curvature.
Properties
Every space of constant curvature is locally symmetric, i.e. its curvature tensor is parallel .
Every space of constant curvature is locally maximally symmetric, i.e. it has number of local isometries, where is its dimension.
Conversely, there exists a similar but stronger statement: every maximally symmetric space, i.e. a space which has (global) isometries, has constant curvature.
(Killing–Hopf theorem) The universal cover of a manifold of constant sectional curvature is one of the model spaces:
sphere (sectional curvature positive)
plane (sectional curvature zero)
hyperbolic manifold (sectional curvature negative)
A space of constant curvature which is geodesically complete is called space form and the study of space forms is intimately related to generalized crystallography (see the article on space form for more details).
Two space forms are isomorphic if and only if they have the same dimension, their metrics possess the same signature and their sectional curvatures are equal. |
https://en.wikipedia.org/wiki/Achondrogenesis | Achondrogenesis is a number of disorders that are the most severe form of congenital chondrodysplasia (malformation of bones and cartilage). These conditions are characterized by a small body, short limbs, and other skeletal abnormalities. As a result of their serious health problems, infants with achondrogenesis are usually born prematurely, are stillborn, or die shortly after birth from respiratory failure. Some infants, however, have lived for a while with intensive medical support.
Researchers have described at least three forms of achondrogenesis, designated as Achondrogenesis type 1A, achondrogenesis type 1B and achondrogenesis type 2. These types are distinguished by their signs and symptoms, inheritance pattern, and genetic cause. Other types of achondrogenesis may exist, but they have not been characterized or their cause is unknown.
Achondrogenesis type 1A is caused by a defect in the microtubules of the Golgi apparatus. In mice, a nonsense mutation in the thyroid hormone receptor interactor 11 gene (Trip11), which encodes the Golgi microtubule-associated protein 210 (GMAP-210), resulted in defects similar to the human disease. When their DNA was sequenced, human patients with achondrogenesis type 1A also had loss-of-function mutations in GMAP-210. GMAP-210 moves proteins from the endoplasmic reticulum to the Golgi apparatus. Because of the defect, GMAP-210 is not able to move the proteins, and they remain in the endoplasmic reticulum, which swells up. The loss of Golgi apparatus function affects some cells, such as those responsible for forming bone and cartilage, more than others.
Achondrogenesis type 1B is caused by a similar mutation in SLC26A2, which encodes a sulfate transporter.
Achondrogenesis, type 2 is one of several skeletal disorders caused by mutations in the COL2A1 gene. Achondrogenesis, type 2 and hypochondrogenesis (a similar skeletal disorder) together affect 1 in 40,000 to 60,000 births. |
https://en.wikipedia.org/wiki/Time%20crystal | In condensed matter physics, a time crystal is a quantum system of particles whose lowest-energy state is one in which the particles are in repetitive motion. The system cannot lose energy to the environment and come to rest because it is already in its quantum ground state. Because of this, the motion of the particles does not really represent kinetic energy like other motion; it has "motion without energy". Time crystals were first proposed theoretically by Frank Wilczek in 2012 as a time-based analogue to common crystals – whereas the atoms in crystals are arranged periodically in space, the atoms in a time crystal are arranged periodically in both space and time. Several different groups have demonstrated matter with stable periodic evolution in systems that are periodically driven. In terms of practical use, time crystals may one day be used as quantum computer memory.
The existence of crystals in nature is a manifestation of spontaneous symmetry breaking, which occurs when the lowest-energy state of a system is less symmetrical than the equations governing the system. In the crystal ground state, the continuous translational symmetry in space is broken and replaced by the lower discrete symmetry of the periodic crystal. As the laws of physics are symmetrical under continuous translations in time as well as space, the question arose in 2012 as to whether it is possible to break symmetry temporally, and thus create a "time crystal" that is resistant to entropy.
If a discrete time translation symmetry is broken (which may be realized in periodically driven systems), then the system is referred to as a discrete time crystal. A discrete time crystal never reaches thermal equilibrium, as it is a type (or phase) of non-equilibrium matter. Breaking of time symmetry can only occur in non-equilibrium systems. Discrete time crystals have in fact been observed in physics laboratories as early as 2016 (published in 2017). One example of a time crystal, which demonstrate |
https://en.wikipedia.org/wiki/Silk%20screen%20effect | The silk screen effect (SSE) is a visual phenomenon seen in rear-projection televisions. SSE is described by viewers as seeing the texture of the television screen in front of the image. SSE may be found on all rear-projection televisions including DLP and Liquid Crystal on Silicon (LCoS). The effect is most visible when viewing bright white or very light colored images. Viewers also report seeing "sparkles" when viewing very bright colored images.
SSE's nomenclature comes from the visual appearance of this effect, which is likened to viewing an image through a silk screen. SSE should not be confused with the screen door effect, another visual phenomenon seen in rear-projection televisions.
Cause of SSE
SSE is caused by textured screens used in most rear-projection televisions. Rear-projection television manufacturers use textured screens to increase the viewing angle of the television.
Reducing SSE
SSE can be reduced by properly calibrating the picture controls of the rear-projection television. SSE is most prominent when the contrast and brightness are set too high. Adjusting the brightness and contrast and properly calibrating the picture controls can reduce SSE.
See also
Digital Light Processing
Liquid Crystal on Silicon
Screen-door effect |
https://en.wikipedia.org/wiki/Pleurotus%20cornucopiae | Pleurotus cornucopiae is a species of edible fungus in the genus Pleurotus, It is quite similar to the better-known Pleurotus ostreatus, and like that species is cultivated and sold in markets in Europe and China, but it is distinguished because its gills are very decurrent, forming a network on the stem.
Naming
The species name means "of the Cornucopia" (horn of plenty), which is appropriate since the mushrooms are edible and sometimes take on a shape similar to a drinking horn.
The original definition of this species, or basionym, was made by Jean-Jacques Paulet in 1793 as Dendrosarcos cornucopiae. At a time when most gilled mushrooms were lumped into genus Agaricus, Paulet invented genus Dendrosarcos, later Latinised to Dendrosarcus, for those having an excentric or missing stipe. In fact those fungi have not been found to be a closely related group, and today the name only has historical interest, though the taxonomic rules imply that it still needs to be recorded. In 1871 in his "Führer in die Pilzkunde" ("Guide to Mycology"), Paul Kummer introduced Pleurotus as a genus, but the allocation of P. cornucopiae to it was only done later in 1910 by Léon Louis Rolland.
The synonym Pleurotus sapidus due to Schulzer (1873) is sometimes seen
The English name "Branched Oyster Mushroom" has been given to this species.
Description
The following sections use the given references throughout.
General
The cap grows to about 15 cm, with a pale yellowish, brownish or greyish surface. At most there may be very slight traces of the veil.
The stem is always present, may be forked and can vary from excentric to fairly central. Each stem may be up to about 12 cm long and up to 2 cm thick.
The whitish gills are decurrent down the stem and anastomose (criss-cross), becoming a network of ridges at the bottom.
The strong smell has an aniseed element and is also floury when the mushroom is cut. The taste is floury.
Microscopic characteristics
The flesh may be monomitic (as |
https://en.wikipedia.org/wiki/Poqet%20PC | The Poqet PC is a very small, portable IBM PC compatible computer, introduced in 1989 by Poqet Computer Corporation with a price of $2000. The computer was discontinued after Fujitsu Ltd. bought Poqet Computer Corp. It was the first subnotebook form factor IBM PC compatible computer that ran MS-DOS. The Poqet PC is powered by two AA-size batteries. Through the use of aggressive power management, which includes stopping the CPU between keystrokes, the batteries are able to power the computer for anywhere between a couple of weeks and a couple of months, depending on usage. The computer also uses an "instant on" feature, such that after powering it down, it can be used again immediately without having to go through a full booting sequence. The Poqet PC is comparable to the HP 95LX/HP 100LX/HP 200LX and the Atari Portfolio handheld computers.
Poqet PC, "Classic" and Prime
Three variants were produced. The Poqet PC was the first to be introduced and the Poqet PC Prime followed shortly after. (The original version was subsequently renamed the Poqet PC "Classic"). Several years later, the Poqet PC Plus was introduced. The main difference between the Poqet PC Classic and the Prime was the expansion of RAM from 512 to 640 KB and enhancement of the power management features.
Specifications
Size: x x
Weight: with batteries
Battery life: 50–100 hours (expect a lot less if running long, CPU-intensive programs (10-20 h approx.))
Microprocessor: 80C88 / 7 MHz
Memory: 640 KB SRAM
Display: Reflective DSTN (no backlight)
Display compatibility: MDA: 80 × 25 characters CGA: 640 × 200 pixels
PCMCIA: 2 × Type I, Revision 1.0 memory card slots
Secondary storage: Drive A: 512 KB-2 MB PCMCIA (not included) Drive B: 512-2 MB PCMCIA (not included) Drive C: 768 KB ROM drive with MS-DOS 3.3 and PoqetTools Drive D: 22 KB volatile RAM drive
Built-in software: MS-DOS 3.3, PoqetLink, and PoqetTools
Poqet PC Plus
Several years after the Poqet Prime and Classic, and some time after |
https://en.wikipedia.org/wiki/Nonlinear%20conjugate%20gradient%20method | In numerical optimization, the nonlinear conjugate gradient method generalizes the conjugate gradient method to nonlinear optimization. For a quadratic function
the minimum of is obtained when the gradient is 0:
.
Whereas linear conjugate gradient seeks a solution to the linear equation
, the nonlinear conjugate gradient method is generally
used to find the local minimum of a nonlinear function
using its gradient alone. It works when the function is approximately quadratic near the minimum, which is the case when the function is twice differentiable at the minimum and the second derivative is non-singular there.
Given a function of variables to minimize, its gradient indicates the direction of maximum increase.
One simply starts in the opposite (steepest descent) direction:
with an adjustable step length and performs a line search in this direction until it reaches the minimum of :
,
After this first iteration in the steepest direction , the following steps constitute one iteration of moving along a subsequent conjugate direction , where :
Calculate the steepest direction: ,
Compute according to one of the formulas below,
Update the conjugate direction:
Perform a line search: optimize ,
Update the position: ,
With a pure quadratic function the minimum is reached within N iterations (excepting roundoff error), but a non-quadratic function will make slower progress. Subsequent search directions lose conjugacy requiring the search direction to be reset to the steepest descent direction at least every N iterations, or sooner if progress stops. However, resetting every iteration turns the method into steepest descent. The algorithm stops when it finds the minimum, determined when no progress is made after a direction reset (i.e. in the steepest descent direction), or when some tolerance criterion is reached.
Within a linear approximation, the parameters and are the same as in the
linear conjugate gradient method but have been obtaine |
https://en.wikipedia.org/wiki/Email%20spoofing | Email spoofing is the creation of email messages with a forged sender address. The term applies to email purporting to be from an address which is not actually the sender's; mail sent in reply to that address may bounce or be delivered to an unrelated party whose identity has been faked. Disposable email address or "masked" email is a different topic, providing a masked email address that is not the user's normal address, which is not disclosed (for example, so that it cannot be harvested), but forwards mail sent to it to the user's real address.
The original transmission protocols used for email do not have built-in authentication methods: this deficiency allows spam and phishing emails to use spoofing in order to mislead the recipient. More recent countermeasures have made such spoofing from internet sources more difficult but they have not eliminated it completely; few internal networks have defences against a spoof email from a colleague's compromised computer on that network. Individuals and businesses deceived by spoof emails may suffer significant financial losses; in particular, spoofed emails are often used to infect computers with ransomware.
Technical details
When a Simple Mail Transfer Protocol (SMTP) email is sent, the initial connection provides two pieces of address information:
MAIL FROM: - generally presented to the recipient as the Return-path: header but not normally visible to the end user, and by default no checks are done that the sending system is authorized to send on behalf of that address.
RCPT TO: - specifies which email address the email is delivered to, is not normally visible to the end user but may be present in the headers as part of the "Received:" header.
Together, these are sometimes referred to as the "envelope" addressing – an analogy to a traditional paper envelope. Unless the receiving mail server signals that it has problems with either of these items, the sending system sends the "DATA" command, and typically sends severa |
https://en.wikipedia.org/wiki/Proof%20sketch%20for%20G%C3%B6del%27s%20first%20incompleteness%20theorem | This article gives a sketch of a proof of Gödel's first incompleteness theorem. This theorem applies to any formal theory that satisfies certain technical hypotheses, which are discussed as needed during the sketch. We will assume for the remainder of the article that a fixed theory satisfying these hypotheses has been selected.
Throughout this article the word "number" refers to a natural number (including 0). The key property these numbers possess is that any natural number can be obtained by starting with the number 0 and adding 1 a finite number of times.
Hypotheses of the theory
Gödel's theorem applies to any formal theory that satisfies certain properties. Each formal theory has a signature that specifies the nonlogical symbols in the language of the theory. For simplicity, we will assume that the language of the theory is composed from the following collection of 15 (and only 15) symbols:
A constant symbol for zero.
A unary function symbol for the successor operation and two binary function symbols + and × for addition and multiplication.
Three symbols for logical conjunction, , disjunction, , and negation, ¬.
Two symbols for universal, , and existential, , quantifiers.
Two symbols for binary relations, = and <, for equality and order (less than).
Two symbols for left, and right, parentheses for establishing precedence of quantifiers.
A single variable symbol, and a distinguishing symbol that can be used to construct additional variables of the form x*, x**, x***, ...
This is the language of Peano arithmetic. A well-formed formula is a sequence of these symbols that is formed so as to have a well-defined reading as a mathematical formula. Thus is well formed while is not well formed. A theory is a set of well-formed formulas with no free variables.
A theory is consistent if there is no formula such that both and its negation are provable. ω-consistency is a stronger property than consistency. Suppose that is a formula with one fr |
https://en.wikipedia.org/wiki/Process%20control%20network | A Process Control Network (PCN) is a communications network layer that is a part of the Industrial Automation networks in Process Industries. This network is used to transmit instructions and data between control and measurement units and Supervisory Control and Data Acquisition (SCADA) equipment.
Industry requirements
These networks have, over the years, used many of the technologies and topologies utilised in other network applications. However, Process Control Networks (PCNs) have several special requirements that must be met in order for the solution to be acceptable to the industry. These requirements are, in no particular order: Robustness, Determinacy, Compatibility. Robustness includes requirements such as connection redundancy, reduced sensitivity to Electromagnetic Interference (EMI), and good error checking and correction. Determinacy involves assuring that each device is guaranteed access to the network, and in many cases mechanisms to allow priority information (such as alarms) through the system. Compatibility allows SCADA and Distributed Control Systems (DCS) from various manufacturers to communicate with control and measurement equipment from others.
Development of standards
Many early PCNs were serial based, using low level standards such as EIA RS-422 and EIA RS-485 with proprietary protocols on top. One of the de facto standards (which is now becoming an open standard) is Modbus, originally from Modicon. Many PCNs used token passing based protocols because they are essentially deterministic. Both Allen Bradley and Eurotherm utilised such mechanisms. Many of the measurement and control unit manufacturers signed up to the Fieldbus consortium but rather than one standard emerging each manufacturer promoted their own 'standard' leading to a myriad, and confusing, range of physical and logical systems. Modern process control networks rely on Ethernet, TCP/IP, and Microsoft Windows technology. |
https://en.wikipedia.org/wiki/Suzhou%20numerals | The Suzhou numerals, also known as (), is a numeral system used in China before the introduction of Hindu numerals. The Suzhou numerals are also known as (), (), (), () and ().
History
The Suzhou numeral system is the only surviving variation of the rod numeral system. The rod numeral system is a positional numeral system used by the Chinese in mathematics. Suzhou numerals are a variation of the Southern Song rod numerals.
Suzhou numerals were used as shorthand in number-intensive areas of commerce such as accounting and bookkeeping. At the same time, standard Chinese numerals were used in formal writing, akin to spelling out the numbers in English. Suzhou numerals were once popular in Chinese marketplaces, such as those in Hong Kong and Chinese restaurants in Malaysia before the 1990s, but they have gradually been supplanted by Arabic numerals. This is similar to what had happened in Europe with Roman numerals used in ancient and medieval Europe for mathematics and commerce. Nowadays, the Suzhou numeral system is only used for displaying prices in Chinese markets or on traditional handwritten invoices.
Symbols
In the Suzhou numeral system, special symbols are used for digits instead of the Chinese characters. The digits of the Suzhou numerals are defined between U+3021 and U+3029 in Unicode. An additional three code points starting from U+3038 were added later.
The symbols for 5 to 9 are derived from those for 0 to 4 by adding a vertical bar on top, which is similar to adding an upper bead which represents a value of 5 in an abacus. The resemblance makes the Suzhou numerals intuitive to use together with the abacus as the traditional calculation tool.
The numbers one, two, and three are all represented by vertical bars. This can cause confusion when they appear next to each other. Standard Chinese ideographs are often used in this situation to avoid ambiguity. For example, "21" is written as "" instead of "" which can be confused with "3" (). The first |
https://en.wikipedia.org/wiki/CidA/LrgA%20holin | The CidA/LrgA Holin (CidA/LrgA Holin) Family (TC# 1.E.14) is a group of proteins named after CidA (TC# 1.E.14.1.2) and LrgA (TC# 1.E.14.1.1) of Staphylococcus aureus. CidA and LrgA are homologous holin and anti-holin proteins, each with 4 putative transmembrane segments (TMSs). Members of the CidA/LrgA holin family also include putative murine hydrolase exporters from a wide range of Gram-positive and Gram-negative bacteria as well as archaea. Most CidA/LrgA holin family proteins vary in size between 100 and 160 amino acyl residues (aas) in length although a few are larger.
Function
It has been proposed that CidA and CidB (23% and 32% identical to LrgA and LrgB, respectively) are involved in programmed cell death in a process that is analogous to apoptosis in eukaryotes. These proteins are known to regulate and influence biofilm formation by releasing DNA from lysed cells which contributes to the biofilm matrix. CidA, a 131 aa protein with 4 putative TMSs, is believed to be the holin which exports the autolysin CidB, while LrgA may be an anti-holin, a protein that binds and inhibits holin activity. If this is a general mechanism for programmed cell death, this would explain their near ubiquity in the prokaryotic world.
Expression
The cidABC operon is activated by CidR in the presence of acetic acid. Both CidAB and LrgAB affect biofilm formation, oxidative stress, stationary phase survival and antibiotic tolerance in a reciprocal fashion, and their genes are regulated by the LytSR two component regulatory system. Microfluidic techniques have been used to follow gene expression temporally and spatially during biofilm formation, revealing that both cidA and lrgA are expressed mostly in the interior of tower structures in the biofilms, regulated by oxygen availability. Analogous proteins may be linked to competence in S. mutants.
See also
Holin
Lysin
Transporter Classification Database
Further reading |
https://en.wikipedia.org/wiki/200%20new%20shekel%20banknote | The two hundred new shekel note (₪200) is the highest denomination banknote of the Israeli new shekel, It was first issued in Series A 1992 with the Series B in 1999 and Series C in 2015 the latest.
Design
Security features (New Shekel Series C)
LOOK at the banknote
The transparent portrait: A watermark image of the portrait, identical to the portrait shown on the banknote observe, with the denomination next to it. Hold the banknote up to the light and make sure that the portrait and the denomination are visible. This feature can be viewed from either side of the banknote.
The perforated numerals: Tiny holes forming the shape of the banknote's denomination (200) are perforated at the top part of the banknote. Hold the banknote up to the light and make sure you notice them. This feature can be viewed from either side of the banknote.
The window thread: A blue-purple security thread is embedded in the banknote and is revealed in three "windows" on the back of the banknote. Hold the banknote up to the light and make sure that the portrait and the nominal value are clearly visible in the windows. The thread will change its shade from blue to purple when tilting the banknote.
FEEL the banknote
The raised ink: The portrait the Governor's signature, the Hebrew and Gregorian year, text in three languages, and the designated features for the blind on the banknote's margins are printed in intaglio. Touch these details with your finger, on both sides of the banknote, and you can feel the raised ink.
TILT the banknote
The glittering stripe: A transparent and glittering stripe is incorporated into the banknote vertically, next to the portrait. Tilt the banknote in various directions and make sure that the Menorah symbol and the denomination appear and disappear intermittently along the stripe.
The golden book: An artistic reflective foil element in the shape of an "open golden book". Tilt the banknote backward and forward and make sure that the "book" changes its |
https://en.wikipedia.org/wiki/Primate%20cognition | Primate cognition is the study of the intellectual and behavioral skills of non-human primates, particularly in the fields of psychology, behavioral biology, primatology, and anthropology.
Primates are capable of high levels of cognition; some make tools and use them to acquire foods and for social displays; some have sophisticated hunting strategies requiring cooperation, influence and rank; they are status conscious, manipulative and capable of deception; they can recognise kin and conspecifics; they can learn to use symbols and understand aspects of human language including some relational syntax, concepts of number and numerical sequence.
Studies in primate cognition
Theory of Mind
Theory of mind (also known as mental state attribution, mentalizing, or mindreading) can be defined as the "ability to track the unobservable mental states, like desires and beliefs, that guide others' actions". Premack and Woodruff's 1978 article "Does the chimpanzee have a theory of mind?" sparked a contentious issue because of the problem of inferring from animal behavior the existence of thinking, of the existence of a concept of self or self-awareness, or of particular thoughts.
Non-human research still has a major place in this field, however, and is especially useful in illuminating which nonverbal behaviors signify components of theory of mind, and in pointing to possible stepping points in the evolution of what many claim to be a uniquely human aspect of social cognition. While it is difficult to study human-like theory of mind and mental states in species which we do not yet describe as "minded" at all, and about whose potential mental states we have an incomplete understanding, researchers can focus on simpler components of more complex capabilities.
For example, many researchers focus on animals' understanding of intention, gaze, perspective, or knowledge (or rather, what another being has seen). Part of the difficulty in this line of research is that observed phenom |
https://en.wikipedia.org/wiki/Fork%20and%20pull%20model | Fork and pull model refers to a software development model mostly used on GitHub, where multiple developers working on an open, shared project make their own contributions by sharing a main repository and pushing changes after granted pull request by integrator users. Followed by the advent of distributed version control systems (DVCS), Git naturally enables the usage of a pull-based development model, in which developers can copy the project onto their own repository and then push their changes to the original repository, where the integrators will determine the validity of the pull request. Since its appearance, pull-based development has gained popularity within the open software development community. On GitHub, over 400,000 pull-requests emerged per month on average in 2015. It is also the model shared on most collaborative coding platforms, like Bitbucket, Gitorious, etc. More and more functionalities are added to facilitate pull-based model. |
https://en.wikipedia.org/wiki/Ptolemy%27s%20table%20of%20chords | The table of chords, created by the Greek astronomer, geometer, and geographer Ptolemy in Egypt during the 2nd century AD, is a trigonometric table in Book I, chapter 11 of Ptolemy's Almagest, a treatise on mathematical astronomy. It is essentially equivalent to a table of values of the sine function. It was the earliest trigonometric table extensive enough for many practical purposes, including those of astronomy (an earlier table of chords by Hipparchus gave chords only for arcs that were multiples of ). Since the 8th and 9th centuries, the sine and other trigonometric functions have been used in Islamic mathematics and astronomy, reforming the production of sine tables. Khwarizmi and Habash al-Hasib later produced a set of trigonometric tables.
The chord function and the table
A chord of a circle is a line segment whose endpoints are on the circle. Ptolemy used a circle whose diameter is 120 parts. He tabulated the length of a chord whose endpoints are separated by an arc of n degrees, for n ranging from to 180 by increments of . In modern notation, the length of the chord corresponding to an arc of θ degrees is
As θ goes from 0 to 180, the chord of a θ° arc goes from 0 to 120. For tiny arcs, the chord is to the arc angle in degrees as is to 3, or more precisely, the ratio can be made as close as desired to ≈ by making θ small enough. Thus, for the arc of , the chord length is slightly more than the arc angle in degrees. As the arc increases, the ratio of the chord to the arc decreases. When the arc reaches , the chord length is exactly equal to the number of degrees in the arc, i.e. chord 60° = 60. For arcs of more than 60°, the chord is less than the arc, until an arc of 180° is reached, when the chord is only 120.
The fractional parts of chord lengths were expressed in sexagesimal (base 60) numerals. For example, where the length of a chord subtended by a 112° arc is reported to be 99 29 5, it has a length of
rounded to the nearest |
https://en.wikipedia.org/wiki/Newton%E2%80%93Wigner%20localization | Newton–Wigner localization (named after Theodore Duddell Newton and Eugene Wigner) is a scheme for obtaining a position operator for massive relativistic quantum particles. It is known to largely conflict with the Reeh–Schlieder theorem outside of a very limited scope.
The Newton–Wigner position operators 1, 2, 3, are the premier notion of position
in relativistic quantum mechanics of a single particle. They enjoy the same
commutation relations with the 3 space momentum operators and transform under
rotations in the same way as the , , in ordinary QM. Though formally they have the same properties with respect to 1,
2, 3, as
the position in ordinary QM, they have additional properties: One of these is that
This ensures that the free particle moves at the expected velocity with the given momentum/energy.
Apparently these notions were discovered when attempting to define a self adjoint operator in the relativistic setting that resembled the
position operator in basic quantum mechanics in the sense that at low momenta it
approximately agreed with that operator. It also has several famous strange behaviors (see the Hegerfeldt theorem in particular), one of
which is seen as the motivation for having to introduce quantum field theory. |
https://en.wikipedia.org/wiki/IConnectHere | iConnectHere is the consumer division of Deltathree, which provides VoIP internet telephony service to consumers and businesses worldwide. The company's products are: Broadband (Internet) Phones, PC to Phone service, Mobile Dialers, Calling Cards and local phone numbers.
History
Deltathree was founded in 1996 and on March 14, 1997, first demonstrated a direct telephone conversation over the Internet. By June 1999, deltathree's PC-to-Phone and Phone-to-Phone services became commercially available. In September 2001 the iConnectHere brand and service was launched with even lower rates that initially offered.
On December 19, 2001, Deltathree announced that iConnectHere would offer its PC-to-phone service to MSN Messenger and Windows Messenger users in 17 countries.
In 2007 Deltathree launched a communications solution called JoIP jointly with Panasonic. JoIP is a service enabling regular phone owners of Panasonic's Globrange to make cheap international calls.
In July 2010 Deltathree launched a communications solution called the JoIP Mobile (mobile.joip.com). This VoIP mobile dialer can be downloaded to the mobile (practically any smartphone) of the user: BlackBerry OS, Symbian OS, Android OS and iPhone. Windows OS and Blackberry will soon be launched as well.
On August 1, 2017, Deltathree, LLC, provider of iConnecthere discontinued service.
Client applications and devices
iConnectHere provides a free client applications such as the PC to Phone Dialer and Mobile Dialers as part of its service; to date the application had 8 major releases (current version is 8). Additionally, iConnectHere offers a free broadband phone adapter from Linksys along with the Pay as you Go World Plans with local receiving calls numbers all over the world among other international and U.S calling plans. |
https://en.wikipedia.org/wiki/13th%20meridian%20west | The meridian 13° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, Greenland, the Atlantic Ocean, Africa, the Southern Ocean, and Antarctica to the South Pole.
The 13th meridian west forms a great circle with the 167th meridian east.
From Pole to Pole
Starting at the North Pole and heading south to the South Pole, the 13th meridian west passes through:
{| class="wikitable plainrowheaders"
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! scope="row" style="background:#b0e0e6;" | Arctic Ocean
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! scope="row" | Western Sahara
| Claimed by
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! scope="row" style="background:#b0e0e6;" | Atlantic Ocean
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| Turtle Islands
|-valign="top"
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! scope="row" style="background:#b0e0e6;" | Atlantic Ocean
| style="background:#b0e0e6;" | Passing just west of Inaccessible Island, Tristan da Cunha, (at )
|-
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! scope="row" style="background:#b0e0e6;" | Southern Ocean
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! scope="row" | Antarctica
| Queen Maud Land, claimed by
|-
|}
See also
12th meridian west
14th meridian west
w013 meridian west |
https://en.wikipedia.org/wiki/Iron%20peak | The iron peak is a local maximum in the vicinity of Fe (Cr, Mn, Fe, Co and Ni) on the graph of the abundances of the chemical elements.
For elements lighter than iron on the periodic table, nuclear fusion releases energy. For iron, and for all of the heavier elements, nuclear fusion consumes energy. Chemical elements up to the iron peak are produced in ordinary stellar nucleosynthesis, with the alpha elements being particularly abundant. Some heavier elements are produced by less efficient processes such as the r-process and s-process. Elements with atomic numbers close to iron are produced in large quantities in supernova due to explosive oxygen and silicon fusion, followed by radioactive decay of nuclei such as Nickel-56. On average, heavier elements are less abundant in the universe, but some of those near iron are comparatively more abundant than would be expected from this trend.
Binding energy
A graph of the nuclear binding energy per nucleon for all the elements shows a sharp increase to a peak near nickel and then a slow decrease to heavier elements. Increasing values of binding energy represent energy released when a collection of nuclei is rearranged into another collection for which the sum of nuclear binding energies is higher. Light elements such as hydrogen release large amounts of energy (a big increase in binding energy) when combined to form heavier nuclei. Conversely, heavy elements such as uranium release energy when converted to lighter nuclei through alpha decay and nuclear fission. is the most thermodynamically favorable in the cores of high-mass stars. Although iron-58 and nickel-62 have even higher (per nucleon) binding energy, their synthesis cannot be achieved in large quantities, because the required number of neutrons is typically not available in the stellar nuclear material, and they cannot be produced in the alpha process (their mass numbers are not multiples of 4).
See also
Abundances of the elements (data page) |
https://en.wikipedia.org/wiki/Kolmogorov%27s%20three-series%20theorem | In probability theory, Kolmogorov's Three-Series Theorem, named after Andrey Kolmogorov, gives a criterion for the almost sure convergence of an infinite series of random variables in terms of the convergence of three different series involving properties of their probability distributions. Kolmogorov's three-series theorem, combined with Kronecker's lemma, can be used to give a relatively easy proof of the Strong Law of Large Numbers.
Statement of the theorem
Let be independent random variables. The random series converges almost surely in if the following conditions hold for some , and only if the following conditions hold for any :
Proof
Sufficiency of conditions ("if")
Condition (i) and Borel–Cantelli give that for large, almost surely. Hence converges if and only if converges. Conditions (ii)-(iii) and Kolmogorov's Two-Series Theorem give the almost sure convergence of .
Necessity of conditions ("only if")
Suppose that converges almost surely.
Without condition (i), by Borel–Cantelli there would exist some such that for infinitely many , almost surely. But then the series would diverge. Therefore, we must have condition (i).
We see that condition (iii) implies condition (ii): Kolmogorov's two-series theorem along with condition (i) applied to the case gives the convergence of . So given the convergence of , we have converges, so condition (ii) is implied.
Thus, it only remains to demonstrate the necessity of condition (iii), and we will have obtained the full result. It is equivalent to check condition (iii) for the series
where for each , and are IID—that is, to employ the assumption that , since is a sequence of random variables bounded by 2, converging almost surely, and with . So we wish to check that if converges, then converges as well. This is a special case of a more general result from martingale theory with summands equal to the increments of a martingale sequence and the same conditions (; the series of the variances i |
https://en.wikipedia.org/wiki/Particle%20method | Particle methods is a widely used class of numerical algorithms in scientific computing. Its application ranges from computational fluid dynamics (CFD) over molecular dynamics (MD) to discrete element methods.
History
One of the earliest particle methods is smoothed particle hydrodynamics, presented in 1977. Libersky et al. were the first to apply SPH in solid mechanics. The main drawbacks of SPH are inaccurate results near boundaries and tension instability that was first investigated by Swegle.
In the 1990s a new class of particle methods emerged. The reproducing kernel particle method (RKPM) emerged, the approximation motivated in part to correct the kernel estimate in SPH: to give accuracy near boundaries, in non-uniform discretizations, and higher-order accuracy in general. Notably, in a parallel development, the Material point methods were developed around the same time which offer similar capabilities. During the 1990s and thereafter several other varieties were developed including those listed below.
List of methods and acronyms
The following numerical methods are generally considered to fall within the general class of "particle" methods. Acronyms are provided in parentheses.
Smoothed particle hydrodynamics (SPH) (1977)
Dissipative particle dynamics (DPD) (1992)
Reproducing kernel particle method (RKPM) (1995)
Moving particle semi-implicit (MPS)
Particle-in-cell (PIC)
Moving particle finite element method (MPFEM)
Cracking particles method (CPM) (2004)
Immersed particle method (IPM) (2006)
Definition
The mathematical definition of particle methods captures the structural commonalities of all particle methods. It, therefore, allows for formal reasoning across application domains.
The definition is structured into three parts:
First, the particle method algorithm structure, including structural components, namely data structures, and functions.
Second, the definition of a particle method instance. A particle method instance describes a speci |
https://en.wikipedia.org/wiki/Trusted%20Computing | Trusted Computing (TC) is a technology developed and promoted by the Trusted Computing Group. The term is taken from the field of trusted systems and has a specialized meaning that is distinct from the field of confidential computing. With Trusted Computing, the computer will consistently behave in expected ways, and those behaviors will be enforced by computer hardware and software. Enforcing this behavior is achieved by loading the hardware with a unique encryption key that is inaccessible to the rest of the system and the owner.
TC is controversial as the hardware is not only secured for its owner, but also secured against its owner. Such controversy has led opponents of trusted computing, such as free software activist Richard Stallman, to refer to it instead as treacherous computing, even to the point where some scholarly articles have begun to place scare quotes around "trusted computing".
Trusted Computing proponents such as International Data Corporation, the Enterprise Strategy Group and Endpoint Technologies Associates state that the technology will make computers safer, less prone to viruses and malware, and thus more reliable from an end-user perspective. They also state that Trusted Computing will allow computers and servers to offer improved computer security over that which is currently available. Opponents often state that this technology will be used primarily to enforce digital rights management policies (imposed restrictions to the owner) and not to increase computer security.
Chip manufacturers Intel and AMD, hardware manufacturers such as HP and Dell, and operating system providers such as Microsoft include Trusted Computing in their products if enabled. The U.S. Army requires that every new PC it purchases comes with a Trusted Platform Module (TPM). As of July 3, 2007, so does virtually the entire United States Department of Defense.
Key concepts
Trusted Computing encompasses six key technology concepts, of which all are required for a full |
https://en.wikipedia.org/wiki/NetWare%20Link%20Services%20Protocol | NetWare Link Services Protocol (NLSP) is a routing protocol for Internetwork Packet Exchange based on the Intermediate-System-to-Intermediate-System (IS-IS) protocol developed by the International Organization for Standardization (ISO). NLSP enables NetWare servers to exchange routing and service information without the high broadcast overhead generated by Routing Information Protocol and Service Advertising Protocol. Instead of periodically retransmitting its information every few minutes like RIP and SAP, NLSP only transmits every two hours, or when there is a change in a route or service, making it much more suitable for use over a wide area network.
See also
IS-IS
Routing Information Protocol
Service Advertising Protocol
NetWare |
https://en.wikipedia.org/wiki/Toronto-Addis%20Ababa%20Academic%20Collaboration | The Toronto-Addis Ababa Academic Collaboration is a university educational program to teach medicine in Ethiopia.
The Toronto-Addis Ababa Academic Collaboration was launched in 2008, as a wider program that grew from an earlier 2003 collaboration called the Toronto Addis Ababa Psychiatry Program.
The Toronto-Addis Ababa Academic Collaboration involves the University of Toronto providing teaching support to Addis Ababa University. Both universities pay costs, the program is run frugally, and it does not receive any external funding.
Since it started, the scope of the collaboration has grown to include 24 medical and non-medical academic disciplines.
History
The Toronto-Addis Ababa Academic Collaboration is the successor to the original, and ongoing, Toronto Addis Ababa Psychiatry Program. The Psychiatry Program has a syllabus designed by Addis Ababa University faculty, delivered by University of Toronto faculty.
The Psychiatry Program provides training in physiatry to medical students at Addis Ababa University and works with priests to encourage referral to, and acceptance of, medical care for people with mental illness.
Following discussions that started in 2008, in 2013, the collaboration grew into the Toronto-Addis Ababa Academic Collaboration in Emergency Medicine, and the partnership expanded to include the University of Wisconsin. The Emergency Medicine teaching is done at the Black Lion Hospital (also known as Tikur Anbessa Hospital) in Addis Ababa. The first graduates of the emergency medicine program graduated in 2016.
Outcomes
As of 2017, 222 Ethiopian graduates have become university faculty due to assistance from the collaboration and a further 143 were enrolled in ongoing education.
The program has increased the number of psychiatry graduates in Ethiopia and reduced the percentage of Ethiopian medical graduates who leave the country after graduation. |
https://en.wikipedia.org/wiki/John%20Goss-Custard | Dr John D. Goss-Custard is a British behavioural ecologist; he was one of the first scientists to carry out field work on foraging behaviour making use of optimising models, specifically the optimal diet model. After completing a BSc degree in Zoology at the University of Bristol, he moved to the University of Aberdeen to carry out research for a PhD degree, which he was awarded in 1966. The University of Aberdeen awarded him its DSc degree in 1987.
Goss-Custard's PhD was based on the study of foraging in the Common Redshank. Subsequently, he worked at the Centre for Ecology and Hydrology's Furzebrook Research Station at Wareham, Dorset, leading an extensive project on the foraging of overwintering Eurasian Oystercatchers on the estuary of the River Exe. This project led to one of the first uses of agent-based modelling to predict ecological relationships in an extended landscape; the model, developed for the Exe estuary, was subsequently tested successfully on the Wash. This work was surveyed in a book that he edited.
Goss-Custard retired from his post at CEH in 2002. Although he did not hold a substantive university post, Goss-Custard held an honorary position at the University of Exeter for many years, and is currently a Visiting Professor at the University of Bournemouth. He co-supervised PhD degrees with colleagues at the University of Exeter and also the University of Oxford. |
https://en.wikipedia.org/wiki/Particle%20physics%20in%20cosmology | Particle physics is the study of the interactions of elementary particles at high energies, whilst physical cosmology studies the universe as a single physical entity. The interface between these two fields is sometimes referred to as particle cosmology. Particle physics must be taken into account in cosmological models of the early universe, when the average energy density was very high. The processes of particle pair production, scattering and decay influence the cosmology.
As a rough approximation, a particle scattering or decay process is important at a particular cosmological epoch if its time scale is shorter than or similar to the time scale of the universe's expansion. The latter quantity is where is the time-dependent Hubble parameter. This is roughly equal to the age of the universe at that time.
For example, the pion has a mean lifetime to decay of about 26 nanoseconds. This means that particle physics processes involving pion decay can be neglected until roughly that much time has passed since the Big Bang.
Cosmological observations of phenomena such as the cosmic microwave background and the cosmic abundance of elements, together with the predictions of the Standard Model of particle physics, place constraints on the physical conditions in the early universe. The success of the Standard Model at explaining these observations support its validity under conditions beyond those which can be produced in a laboratory. Conversely, phenomena discovered through cosmological observations, such as dark matter and baryon asymmetry, suggest the presence of physics that goes beyond the Standard Model.
Further reading
Bergström, Lars & Goobar, Ariel (2004); Cosmology and Particle Astrophysics, 2nd ed. Springer Verlag. .
Branco, G. C., Shafi, Q., & Silva-Marcos, J. I. (2001). Recent developments in particle physics and cosmology. Dordrecht: Kluwer Academic.
Collins, P. D. B. (2007). Particle physics and cosmology. New York: John Wiley & Sons.
Kazakov, D. I., |
https://en.wikipedia.org/wiki/Ethel%20Vaughan-Sawyer | Ethel May Vaughan-Sawyer (6 July 1868 – 9 March 1949) was a British gynaecological surgeon. She was described by pioneering physician and feminist Louisa Garrett Anderson as "100 times better at her work than I am". A champion of women's rights to work and take part in political life, Vaughan-Sawyer described herself as an example of "healthy normal womanhood usefully and happily employed".
Life
Ethel May Vaughan was born on 6 July 1868 in Derby, the oldest of eight children born to Cedric Vaughan and Jane Ellen Ridley. Her father was a locomotive engineer, who from 1872 was manager of the Hodbarrow Mining Company in Cumberland, where the family moved.
With her two younger sisters, Ethel was educated at a private school in Bottesford, Leicestershire, and later in Lausanne. From 1889, she studied at University College London, and in 1891 entered the London School of Medicine for Women, where she excelled. She graduated BS and MB in 1896, and MD in 1898.
In 1907, Vaughan married George Henry Vaughan-Sawyer, a captain and author. The marriage was happy and their daughter, Petronella Grace, was born on 31 August 1908. George Henry Vaughan-Sawyer was killed in action in 1914. Petronella Grace, a designer and illustrator, died in 1931 at the age of 22.
Medical career
In 1897, Vaughan became assistant medical officer to Camberwell Infirmary. She subsequently became curator of the Royal Free Hospital's museum, and in 1899 clinical assistant to physician Raymond Crawfurd. In 1901, she spent time in Paris with fellow physician Louisa Garrett Anderson, visiting French hospitals.
By that year, Vaughan had established a private practice from her home in Brompton Square, South Kensington, alongside her friend Dr. Kate Marion Hunter. When, a year later, Mary Scharlieb was appointed physician for the diseases of women at the Royal Free Hospital, Vaughan was made her assistant. Scharlieb described Vaughan as both "a great pleasure to work with" and "one of the best and most s |
https://en.wikipedia.org/wiki/Rowbottom%20cardinal | In set theory, a Rowbottom cardinal, introduced by , is a certain kind of large cardinal number.
An uncountable cardinal number is said to be - Rowbottom if for every function f: [κ]<ω → λ (where λ < κ) there is a set H of order type that is quasi-homogeneous for f, i.e., for every n, the f-image of the set of n-element subsets of H has < elements. is Rowbottom if it is - Rowbottom.
Every Ramsey cardinal is Rowbottom, and every Rowbottom cardinal is Jónsson. By a theorem of Kleinberg, the theories ZFC + “there is a Rowbottom cardinal” and ZFC + “there is a Jónsson cardinal” are equiconsistent.
In general, Rowbottom cardinals need not be large cardinals in the usual sense: Rowbottom cardinals could be singular. It is an open question whether ZFC + “ is Rowbottom” is consistent. If it is, it has much higher consistency strength than the existence of a Rowbottom cardinal. The axiom of determinacy does imply that is Rowbottom (but contradicts the axiom of choice). |
https://en.wikipedia.org/wiki/Effective%20dose%20%28pharmacology%29 | In pharmacology, an effective dose (ED) or effective concentration (EC) is the minimum dose or concentration of a drug that produces a biological response. The term "effective dose" is used when measurements are taken in vivo, while "effective concentration" is used when the measurements are taken in vitro.
It has been stated that any substance can be toxic at a high enough dose. This concept was exemplified in 2007 when a California woman died of water intoxication in a contest sanctioned by a radio station. The line between efficacy and toxicity is dependent upon the particular patient, although the dose administered by a physician should fall into the predetermined therapeutic window of the drug.
The importance of determining the therapeutic range of a drug cannot be overstated. This is generally defined by the range between the minimum effective dose (MED) and the maximum tolerated dose (MTD). The MED is defined as the lowest dose level of a pharmaceutical product that provides a clinically significant response in average efficacy, which is also statistically significantly superior to the response provided by the placebo. Similarly, the MTD is the highest possible but still tolerable dose level with respect to a pre-specified clinical limiting toxicity. In general, these limits refer to the average patient population. For instances in which there is a large difference between the MED and MTD, it is stated that the drug has a large therapeutic window. Conversely, if the range is relatively small, or if the MTD is less than the MED, then the pharmaceutical product will have little to no practical value.
ED50
The median effective dose is the dose that produces a quantal effect (all or nothing) in 50% of the population that takes it (median referring to the 50% population base). It is also sometimes abbreviated as the ED50, meaning "effective dose for 50% of the population". The ED50 is commonly used as a measure of the reasonable expectancy of a drug effect, b |
https://en.wikipedia.org/wiki/Software%20development%20process | In software engineering, a software development process is a process of planning and managing software development. It typically involves dividing software development work into smaller, parallel, or sequential steps or sub-processes to improve design and/or product management. It is also known as a software development life cycle (SDLC). The methodology may include the pre-definition of specific deliverables and artifacts that are created and completed by a project team to develop or maintain an application.
Most modern development processes can be vaguely described as agile. Other methodologies include waterfall, prototyping, iterative and incremental development, spiral development, rapid application development, and extreme programming.
A life-cycle "model" is sometimes considered a more general term for a category of methodologies and a software development "process" is a more specific term to refer to a specific process chosen by a specific organization. For example, there are many specific software development processes that fit the spiral life-cycle model. The field is often considered a subset of the systems development life cycle.
History
The software development methodology (also known as SDM) framework didn't emerge until the 1960s. According to Elliott (2004), the systems development life cycle (SDLC) can be considered to be the oldest formalized methodology framework for building information systems. The main idea of the SDLC has been "to pursue the development of information systems in a very deliberate, structured and methodical way, requiring each stage of the life cycle––from the inception of the idea to delivery of the final system––to be carried out rigidly and sequentially" within the context of the framework being applied. The main target of this methodology framework in the 1960s was "to develop large scale functional business systems in an age of large scale business conglomerates. Information systems activities revolved around heavy |
https://en.wikipedia.org/wiki/Oligopeptidase | An Oligopeptidase is an enzyme that cleaves peptides but not proteins. This property is due to its structure: the active site of this enzyme is located at the end of a narrow cavity which can only be reached by peptides.
History
Background
Proteins are essential macromolecules of living organisms. They are continuously being degraded into their constituent amino acids which can be reused in the synthesis of new proteins. Every cellular protein has its own half-life time. In humans, for instance, 50% of the liver and plasma proteins are replaced in 10 days, whereas in muscles it takes 180 days. In average, every 80 days about 50% of our proteins are totally replaced. Although the regulation of protein degradation is as important as their synthesis to keep each cell protein concentration at the optimum level, research in this area remained until the end of the 1970s. Up to this time, lysosomes, discovered in the 1950s by the Belgian cytologist Christian de Duve, were thought responsible for the complete digestion of intra- and extracellular proteins by the lysosomal hydrolytic enzymes.
Between the 1970s and 1980s, this view drastically changed. New experimental evidences showed that, under physiological conditions, non-lysosomal proteases were responsible for limited proteolysis of intra- and/or extracellular proteins, a concept originally conceived by Linderstᴓm-Lang in 1950. Endogenous or exogenous proteins are processed by non-lysosomal proteases into intermediate-sized polypeptides, which display gene and metabolic regulation, neurologic, endocrine, and immunological roles, whose dysfunction might explain a number of pathologies. Consequently, protein degradation did not represent anymore the end of the biological function of proteins, but rather the beginning of a yet unexplored side of the biology of the cells. A number of intra- or extracellular proteases release protein fragments endowed with essential biological activities. These hydrolytic processes coul |
https://en.wikipedia.org/wiki/HarmonyOS | HarmonyOS (HMOS) () is a distributed operating system developed by Huawei for smartphones, tablets, TVs, smart watches, and other smart devices. It has a multikernel design with dual frameworks: the operating system selects suitable kernels from the abstraction layer in the case of devices that use diverse resources.
The operating system was officially launched by Huawei in August 2019.
Architecture
HarmonyOS is designed with a layered architecture, which consists of four layers; the kernel layer at the bottom provides the upper three layers, i.e., the system service layer, framework layer and application layer, with basic kernel capabilities, such as process and thread management, memory management, file system, network management, and peripheral management.
In the kernel layer, the system applies a multikernel design and selects an appropriate kernel for a device with different resource limitations. For wearables, screenless I/O devices and IoT devices, the system is based on real-time operating system LiteOS; while for smartphones and tablets, the system operates by utilizing a Linux kernel subsystem and executing the AOSP code with a modified EMUI user interface, enabling Android apps and HarmonyOS apps to run seamlessly through a compatibility layer in the userland outside the kernel.
The system includes a communication base called DSoftBus for integrating physically separate devices into a virtual Super Device, allowing one device to control others and sharing data among devices with distributed communication capabilities. To address security concerns arising from varying devices, the system provides a hardware-based Trusted Execution Environment (TEE) to prevent leakage of sensitive personal data when they are stored or processed.
It supports several forms of apps, including the apps that can be installed from AppGallery on smartphones and tablets, installation-free Quick apps and lightweight Meta Services accessible by users.
History
Early developmen |
https://en.wikipedia.org/wiki/GDNF%20family%20of%20ligands | The GDNF family of ligands (GFL) consists of four neurotrophic factors: glial cell line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN), and persephin (PSPN). GFLs have been shown to play a role in a number of biological processes including cell survival, neurite outgrowth, cell differentiation and cell migration. In particular signalling by GDNF promotes the survival of dopaminergic neurons.
Signalling complex formation
At the cell surface of target cells, a signalling complex forms, composed of a particular GFL dimer, a receptor tyrosine kinase molecule RET, and a cell surface-bound co-receptor that is a member of the GFRα protein family. The primary ligands for the co-receptors GFRα1, GFRα2, GFRα3, and GFRα4 are GDNF, NRTN, ARTN, and PSPN, respectively.
Upon initial GFL-GFRα complex formation, the complex then brings together two molecules of RET, triggering trans-autophosphorylation of specific tyrosine residues within the tyrosine kinase domain of each RET molecule. Phosphorylation of these tyrosines then initiates intracellular signal transduction processes.
It has been shown that in the case of GDNF, heparan sulfate glycosaminoglycans are also required to be present at the cell surface in order for RET mediated GDNF signalling to occur.
Clinical significance
GFLs are an important therapeutic target for several conditions:
GDNF has shown promising results in two Parkinson's disease clinical trials and in a number of animal trials. Although a different study later reported this as a 'placebo effect', work on perfecting the delivery of GDNF to the putamen is continuing. GDNF is a potent survival factor for central motoneurons and may have clinical importance for the treatment of ALS. Moreover, recent results highlight the importance of GDNF as a new target for drug addiction and alcoholism treatment.
NRTN can also be used for Parkinson’s disease therapy and for epilepsy treatment. NRTN promotes survival of basal forebrain cholinergi |
https://en.wikipedia.org/wiki/Am386 | The Am386 CPU is a 100%-compatible clone of the Intel 80386 design released by AMD in March 1991. It sold millions of units, positioning AMD as a legitimate competitor to Intel, rather than being merely a second source for x86 CPUs (then termed 8086-family).
History and design
While the AM386 CPU was essentially ready to be released prior to 1991, Intel kept it tied up in court. Intel learned of the Am386 when both companies hired employees with the same name who coincidentally stayed at the same hotel, which accidentally forwarded a package for AMD to Intel's employee. AMD had previously been a second-source manufacturer of Intel's Intel 8086, Intel 80186 and Intel 80286 designs, and AMD's interpretation of the contract, made up in 1982, was that it covered all derivatives of them. Intel, however, claimed that the contract only covered the 80286 and prior processors and forbade AMD the right to manufacture 80386 CPUs in 1987. After a few years in the courtrooms, AMD finally won the case and the right to sell their Am386 in March 1991. This also paved the way for competition in the 80386-compatible 32-bit CPU market and so lowered the cost of owning a PC.
While Intel's 386 CPUs had topped out at 33 MHz in 1989, AMD introduced 40 MHz versions of both its 386DX and 386SX out of the gate, extending the lifespan of the architecture. In the following two years the AMD 386DX-40 saw popularity with small manufacturers of PC clones and with budget-minded computer enthusiasts because it offered near-80486 performance at a much lower price than an actual 486. Generally the 386DX-40 performs nearly on par with a 25 MHz 486 due to the 486 needing fewer clock cycles per instruction, thanks to its tighter pipelining (more overlapping of internal processing) in combination with an on-chip CPU cache. However, its 32-bit 40 MHz data bus gave the 386DX-40 comparatively good memory and I/O performance.
Am386DX data
32-bit data bus, can select between either a 32-bit bus or a 16-b |
https://en.wikipedia.org/wiki/Clinical%20Interventions%20in%20Aging | Clinical Interventions in Aging is a peer-reviewed open access medical journal covering research in gerontology. The journal was established in 2006 and is published by Dove Medical Press. The editor-in-chief is Nandu Goswami of the University of Graz.
Abstracting and indexing
The journal is abstracted and indexed in:
According to the Journal Citation Reports, the journal has a 2012 impact factor of 2.651. |
https://en.wikipedia.org/wiki/Cytometry%20Part%20A | Cytometry Part A is a peer-reviewed scientific journal covering all aspects of the study of cytometry that was established in 1980. It is the official journal of the International Society for Advancement of Cytometry.
Cytometry Part A focuses on molecular analysis of cellular systems as well as cell-based spectroscopic analyses and associated bioinformatics/computational methodologies.
Brian Mayall was the journal's founding editor-in-chief until 1998. Jan Visser and Charles Goolsby subsequently succeeded Brian Mayall in this position. Attila Tarnok has served as the Journal's editor-in-chief since 2007.
This journal was formerly known as Cytometry and first published in July 1980 with . It has been published with since 2003. Cytometry Part A is associated with Cytometry Part B, .
The journal is abstracted and indexed in:
BIOSIS Previews
Current Contents
MEDLINE/PubMed
Science Citation Index Expanded
Scopus
According to the Journal Citation Reports, the journal has a 2020 impact factor of 4.355. |
https://en.wikipedia.org/wiki/Timeline%20of%20the%20development%20of%20tectonophysics%20%28after%201952%29 | The evolution of tectonophysics is closely linked to the history of the continental drift and plate tectonics hypotheses. The continental drift/ Airy-Heiskanen isostasy hypothesis had many flaws and scarce data. The fixist/ Pratt-Hayford isostasy, the contracting Earth and the expanding Earth concepts had many flaws as well.
The idea of continents with a permanent location, the geosyncline theory, the Pratt-Hayford isostasy, the extrapolation of the age of the Earth by Lord Kelvin as a black body cooling down, the contracting Earth, the Earth as a solid and crystalline body, is one school of thought. A lithosphere creeping over the asthenosphere is a logical consequence of an Earth with internal heat by radioactivity decay, the Airy-Heiskanen isostasy, thrust faults and Niskanen's mantle viscosity determinations.
Making sense of the puzzle pieces
1953, the Great Global Rift, running along the Mid-Atlantic Ridge, was discovered by Bruce Heezen (Lamont Group) (Puzzle pieces: Seismic-refraction and Sonar survey of the rifts). , , , ,
Their world ocean floor map was published 1977. Austrian painter Heinrich Berann worked on it.
Nowadays the seafloor maps have a better resolution by the SEASAT, Geosat/ERM and ERS-1/ERM (European Remote-Sensing Satellite/Exact Repeat Mission) missions.
World map of earthquake epicenters, oceanic ones mainly .
1954–1963: Alfred Rittmann was elected IAV President (IAV at that time) for three periods.
1956, S. K. Runcorn becomes a drifter. ,
Statistics by Ronald Fisher. ,
Jan Hospers work (magnetic poles and geographical poles coincide the last 23 Ma).
Self-exciting dynamo theory of Elsasser-Bullard.
S. W. Carey, plate tectonics . But he believed here in an Expanding Earth.
1958, Henry William Menard notes that most mid-ocean ridges are halfway between the two continental edges ( cited in ).
1959, analysis of Vanguard satellite orbit suggests "large-scale convection currents in the mantle" .
Seafloor spreading
December |
https://en.wikipedia.org/wiki/Fair%20allocation%20of%20items%20and%20money | Fair allocation of items and money is a class of fair item allocation problems in which, during the allocation process, it is possible to give or take money from some of the participants. Without money, it may be impossible to allocate indivisible items fairly. For example, if there is one item and two people, and the item must be given entirely to one of them, the allocation will be unfair towards the other one. Monetary payments make it possible to attain fairness, as explained below.
Two agents and one item
With two agents and one item, it is possible to attain fairness using the following simple algorithm (which is a variant of cut and choose):
Alice says a price p that she is willing to pay for the item.
George chooses whether to take the item and pay p, or leave the item to Alice so that Alice pays p.
This algorithm assumes that the agents have quasilinear utilities, that is, their utility is the value of items plus the amount of money that they have. If George thinks that Alice's price is low (he is willing to pay more than p), then he takes the item and pay p, and his utility is positive, so he does not envy Alice. Alice, too, does not envy George since his utility - in her eyes - is 0. Similarly, if George thinks that Alice's price is high (he is willing to pay p or more), then he leaves the item to Alice and does not envy, since Alice's utility in his eyes is negative.
The paid money p can later be divided equally between the players, since an equal monetary transfer does not affect the relative utilities. Then, effectively, the buying agent pays p/2 to the selling agent. The total utility of each agent is at least 1/2 of his/her utility for the item. If the agents have different entitlements, then the paid money p should be divided between the partners in proportion to their entitlements.
There are various works extending this simple idea to more than two players and more complex settings. The main fairness criteria in these works is envy-freenes |
https://en.wikipedia.org/wiki/Profinite%20word | In mathematics, more precisely in formal language theory, the profinite words are a generalization of the notion of finite words into a complete topological space. This notion allows the use of topology to study languages and finite semigroups. For example, profinite words are used to give an alternative characterization of the algebraic notion of a variety of finite semigroups.
Definition
Let A an alphabet. The set of profinite words over A consists of the completion of a metric space whose domain is the set of words over A. The distance used to define the metric is given using a notion of separation of words. Those notions are now defined.
Separation
Let M and N be monoids, and let p and q be elements of the monoid M. Let φ be a morphism of monoids from M to N. It is said that the morphism φ separates p and q if . For example, the morphism sending a word to the parity of its length separates the words ababa and abaa. Indeed .
It is said that N separates p and q if there exists a morphism of monoids φ from M to N that separates p and q. Using the previous example, separates ababa and abaa. More generally, separates any words whose size are not congruent modulo n. In general, any two distinct words can be separated, using the monoid whose elements are the factors of p plus a fresh element 0. The morphism sends prefixes of p to themselves and everything else to 0.
Distance
The distance between two distinct words p and q is defined as the inverse of the size of the smallest monoid N separating p and q. Thus, the distance of ababa and abaa is . The distance of p to itself is defined as 0.
This distance d is an ultrametric, that is, . Furthermore it satisfies and .
Since any word p can be separated from any other word using a monoid with |p|+1 elements, where |p| is the length of p, it follows that the distance between p and any other word is at least . Thus the topology defined by this metric is discrete.
Profinite topology
The profinite completion of , de |
https://en.wikipedia.org/wiki/Astrobiology | Astrobiology is a scientific field within the life and environmental sciences that studies the origins, early evolution, distribution, and future of life in the universe by investigating its deterministic conditions and contingent events. As a discipline, astrobiology is founded on the premise that life may exist beyond Earth.
Research in astrobiology comprises three main areas: the study of habitable environments in the Solar System and beyond, the search for planetary biosignatures of past or present extraterrestrial life, and the study of the origin and early evolution of life on Earth.
The field of astrobiology has its origins in the 20th century with the advent of space exploration and the discovery of exoplanets. Early astrobiology research focused on the search for extraterrestrial life and the study of the potential for life to exist on other planets. In the 1960s and 1970s, NASA began its astrobiology pursuits within the Viking program, which was the first US mission to land on Mars and search for signs of life. This mission, along with other early space exploration missions, laid the foundation for the development of astrobiology as a discipline.
Regarding habitable environments, astrobiology investigates potential locations beyond Earth that could support life, such as Mars, Europa, and exoplanets, through research into the extremophiles populating austere environments on Earth, like volcanic and deep sea environments. Research within this topic is conducted utilising the methodology of the geosciences, especially geobiology, for astrobiological applications.
The search for biosignatures involves the identification of signs of past or present life in the form of organic compounds, isotopic ratios, or microbial fossils. Research within this topic is conducted utilising the methodology of planetary and environmental science, especially atmospheric science, for astrobiological applications, and is often conducted through remote sensing and in situ missi |
https://en.wikipedia.org/wiki/Aavasaksa | Aavasaksa is a sharp-edged hill in Ylitornio municipality in Finnish Lapland. It has an elevation of . Aavasaksa is famous for its sights both towards Finland and Sweden, and it is included in the list of the National landscapes of Finland. Decorative hunting cabin "Imperial Lodge" (Keisarinmaja) is one of the buildings on top of the hill. Its construction began with a visit by Alexander II of Russia in mind, but due to political instability it never happened. It's only open in the summer.
Due to Aavasaksa's distinctive elevation above other nearby hills, it was first used by Pierre Louis Maupertuis in the French Geodesic Mission (1736–1737), and later became part of the Struve Geodetic Arc. As a result of this, UNESCO named Aavasaksa a World Heritage Site, along with the 33 other sites used in the Struve Geodetic Arc.
Aavasaksa is often considered the southernmost point in Finland where the midnight sun is literally visible. The hill is surrounded by rivers running next to it: Torne River to the west and the smaller to the east and north.
Asteroid 2678 Aavasaksa is named after the hill. |
https://en.wikipedia.org/wiki/Mangrove%20restoration | Mangrove restoration is the regeneration of mangrove forest ecosystems in areas where they have previously existed. The practice of mangrove restoration is grounded in the discipline of restoration ecology, which aims to “[assist] the recovery of resilience and adaptive capacity of ecosystems that have been degraded, damaged, or destroyed”. Since environmental impacts are an ongoing threat, to successfully restore an ecosystem implies not merely to recreate its former condition, but to strengthen its capacity to adapt to change over time. Mangrove forests are most likely to thrive in the upper half of the intertidal zone. If planted below the mean tide level, or subject to too great a sea level rise, they may fail to thrive. Success will also depend on the species chosen and their suitability to conditions.
Environmental context
Mangrove forests, along with the animal species they shelter, represent globally significant sources of biodiversity and provide humanity with valuable ecosystem services. They are used by mammals, reptiles and migratory birds as feeding and breeding grounds, and provide crucial habitats for fish and crustacean species of commercial importance. The Atlantic goliath grouper for instance, which is currently listed as critically endangered due to overfishing, utilizes mangroves as a nursery for the first 5–6 years of life. The roots of the mangrove physically buffer shorelines from the erosive impacts of ocean waves and storms. Additionally, they protect riparian zones by absorbing floodwaters and slowing down the flow of sediment-loaded river water. This allows sediments to drop to the bottom where they are held in place, thus containing potentially toxic waste products and improving the quality of water and sanitation in coastal communities.
To the human communities who rely on them, mangrove forests represent local sources of sustainable income from the harvest of fish and timber, as well as non-timber forest products such as medicinal |
https://en.wikipedia.org/wiki/Fossil%20%28software%29 | Fossil is a software configuration management, bug tracking system and wiki software server for use in software development created by D. Richard Hipp.
Features
Fossil is a cross-platform DVCS that runs on Linux, BSD derivatives, Mac and Windows. It is capable of performing distributed version control, bug tracking, wiki services, and blogging. The software has a built-in web interface, which reduces project tracking complexity and promotes situational awareness. A user may simply type "fossil ui" from within any check-out and Fossil automatically opens the user's web browser to display a page giving detailed history and status information on that project. The fossil executable may be run as a standalone HTTP server, as a CGI application, accessed via SSH, or run interactively from the CLI.
Being distributed, Fossil requires no central server, although collaboration is made easier by using one.
Content is stored using a SQLite database so that transactions are atomic even if interrupted by a power loss or system crash.
Fossil is free software released under a BSD license (relicensed from previously GPL).
Adoption
Fossil is used for version control by the SQLite project, which is itself a component of Fossil. SQLite transitioned to using Fossil for version control over CVS on 2009-08-12.
Some examples of other projects using Fossil are:
Tcl/Tk Project
Pikchr
LuaSQLite3
libfossil
Androwish, the Tcl implementation for Android
Source code hosting
The following websites provide free source code hosting for Fossil repositories:
Chisel. Original site owner James Turner announced that the site would cease operation on May 1, 2013. After domain ownership was transferred on May 1, 2013, it continued operation.
SourceForge (unofficially through webpages hosting service)
See also
Comparison of revision control software
List of revision control software
Notes |
https://en.wikipedia.org/wiki/List%20of%20mathematical%20topics%20in%20classical%20mechanics | This is a list of mathematical topics in classical mechanics, by Wikipedia page. See also list of variational topics, correspondence principle.
Newtonian physics
Newton's laws of motion
Inertia,
Kinematics, rigid body
Momentum, kinetic energy
Parallelogram of force
Circular motion
Rotational speed
Angular speed
Angular momentum
torque
angular acceleration
moment of inertia
parallel axes rule
perpendicular axes rule
stretch rule
centripetal force, centrifugal force, Reactive centrifugal force
Laplace–Runge–Lenz vector
Euler's disk
elastic potential energy
Mechanical equilibrium
D'Alembert's principle
Degrees of freedom (physics and chemistry)
Frame of reference
Inertial frame of reference
Galilean transformation
Principle of relativity
Conservation laws
Conservation of momentum
Conservation of linear momentum
Conservation of angular momentum
Conservation of energy
Potential energy
Conservative force
Conservation of mass
Law of universal gravitation
Projectile motion
Kepler's laws of planetary motion
Escape velocity
Potential well
Weightlessness
Lagrangian point
N-body problem
Kolmogorov-Arnold-Moser theorem
Virial theorem
Gravitational binding energy
Speed of gravity
Newtonian limit
Hill sphere
Roche lobe
Roche limit
Hamiltonian mechanics
Phase space
Symplectic manifold
Liouville's theorem (Hamiltonian)
Poisson bracket
Poisson algebra
Poisson manifold
Antibracket algebra
Hamiltonian constraint
Moment map
Contact geometry
Analysis of flows
Nambu mechanics
Lagrangian mechanics
Action (physics)
Lagrangian
Euler–Lagrange equations
Noether's theorem
Classical mechanics |
https://en.wikipedia.org/wiki/List%20of%20species%20named%20after%20the%20COVID-19%20pandemic | A number of species have been named after the COVID-19 pandemic. The names of the new species may refer to the virus itself, to the pandemic, to the lockdowns, or to something more intricate, such as the name of a person dead from the disease.
Animals
(in alphabetical order of genera)
Achilia covidia Kurbatov, Cuccodoro & Sabella, 2021 (Insect, Coleoptera, Staphylinidae) – "the epithet of this new species refers to the COVID-19 pandemic and the periods of quarantine during which this study was carried out by the authors".
Achilia pandemica Kurbatov, Cuccodoro & Sabella, 2021 (Insect, Coleoptera, Staphylinidae) – "the epithet of this new species refers to the COVID-19 pandemic and the periods of quarantine during which this study was carried out by the authors".
Achilia quarantena Kurbatov, Cuccodoro & Sabella, 2021 (Insect, Coleoptera, Staphylinidae) – "the epithet of this new species refers to the COVID-19 pandemic and the periods of quarantine during which this study was carried out by the authors".
Allorhogas quarentenus Joele, Zaldívar-Riverón & Penteado-Dias, 2021 (Insect, Hymenoptera, Braconidae) – "The name of this species refers to the COVID-19 pandemics with its subsequent undefined quarantine, which occurred while the authors were describing it".
Carinadelius medicus Ranjith, van Achterbergan Achterberg, Samartsev & Nasser, 2021 (Insect, Hymenoptera, Braconidae) – "Named after Friedrich Kasimir Medikus (1738 – 1808), a German physician and botanist. We dedicate this species with gratitude to all doctors and nurses for their timeless and uncompromising efforts to control COVID-19".
Cephalothrips corona Alavi & Minaei, 2021 (Insect, Thysanoptera, Phlaeothripidae) – "This article was prepared during the first author's quarantine period due to his positive test for the Coronavirus diseases".
Coralliozetus clausus Hastings, 2021 (Fish, Perciformes, Chaenopsidae) – " from the Latin meaning 'enclosed' or 'having been shut off,' in reference to the |
https://en.wikipedia.org/wiki/Chris%20Dyer%20%28engineer%29 | Chris Dyer (born 12 February 1968) is the former head of Vehicle Performance Group at Renault Sport Formula 1 Team and the former race engineer of Michael Schumacher and Kimi Räikkönen at the Ferrari Formula One team.
Early career
Born in Bendigo, Victoria, Dyer worked with the top V8 Supercar outfit, the Tom Walkinshaw owned Holden Racing Team in the mid nineties alongside drivers such as Peter Brock and Craig Lowndes. In 1997, he switched to Walkinshaw's Formula One team Arrows, working as Damon Hill's chief data engineer. In 1998, he stepped up to race engineering, working with drivers such as Jos Verstappen.
Ferrari
For the 2001 season, Dyer moved to Scuderia Ferrari, working as Michael Schumacher's vehicle engineer, alongside Luca Baldisserri. By the end of 2002, Dyer engineered Schumacher at the tests, and after the championships had been won, at the last three races at Monza, Indianapolis and Suzuka. Dyer then race engineered Michael Schumacher to his 2003 and 2004 world titles, appearing with the German on the podium after his triumph at the 2003 Canadian Grand Prix. Dyer was quoted saying that 'One of Michael's strengths is that, apart from driving quickly, he has an understanding of the car and how all the systems work'.
Dyer then took over as Kimi Räikkönen's race engineer when the Finn moved to Ferrari in 2007. Despite suggestions that the pair didn't always get the most from the package, Räikkönen took the title in 2007 at the final race by a single point over Lewis Hamilton and Fernando Alonso. However, after the disappointing results in the 2008 season, Ferrari announced that Dyer would be replaced by Andrea Stella for the 2009 season, with Dyer promoted to chief track engineer.
On 4 January 2011 Ferrari announced that Dyer was replaced as head of race track engineering by former McLaren engineer Pat Fry. This decision was taken after Dyer made the call to bring Fernando Alonso into the pits to cover off the Australian Mark Webber's pit stop in th |
https://en.wikipedia.org/wiki/Abdallat%E2%80%93Davis%E2%80%93Farrage%20syndrome | Abdallat–Davis–Farrage syndrome is a form of phakomatosis, a disease of the central nervous system accompanied by skin abnormalities. It is characterized by the out of the ordinary pigment of the skin that is abnormal to one's genetics or the color perceived on a basis.
The condition is named after the team of medical professionals who first wrote it up, describing the appearance of the syndrome in a family from Jordan. It was characterized in 1980 by Adnan Abdallat, a Jordanian doctor.
Signs and symptoms
Clinical presentation is as follows:
Albinism (hair)
Irregular decreased skin pigmentation
Excessive freckling
Insensitivity to pain
Paraparesis/quadraparesis
Genetics
The syndrome is thought to be inherited as an autosomal recessive genetic trait, meaning that in order to manifest symptoms, a person must inherit a gene for Abdallat–Davis–Farrage syndrome from both parents. As it is also autosomal (not linked to either of the genes that determine gender), it can manifest in both men and women. Those with only one gene are carriers, and they typically manifest no symptoms; in the event that a person inherits both genes, symptoms usually appear before one year of age.
Treatment |
https://en.wikipedia.org/wiki/Arrowroot | Arrowroot is a starch obtained from the rhizomes (rootstock) of several tropical plants, traditionally Maranta arundinacea, but also Florida arrowroot from Zamia integrifolia, and tapioca from cassava (Manihot esculenta), which is often labeled arrowroot. Polynesian arrowroot or pia (Tacca leontopetaloides), and Japanese arrowroot (Pueraria lobata), also called kudzu, are used in similar ways. In India, it is called palua.
History
Archaeological studies in the Americas show evidence of arrowroot cultivation as early as 7,000 years ago. The name may come from aru-aru (meal of meals) in the language of the Caribbean Arawak people, for whom the plant was a staple. It has also been suggested that the name comes from arrowroot's use in treating poison-arrow wounds, as it draws out the poison when applied to the site of the injury.
In the early days of carbonless copy paper, arrowroot, because of its fine grain-size, was a widely used ingredient. After an economical way of centrifugally separating wheat flour was devised, arrowroot lost its role in papermaking.
Uses
Cultivation in Saint Vincent and the Grenadines
Saint Vincent has a long history of arrowroot production. The industry started as the food and medicine of the Carib and Garifuna peoples, and developed to the status of a major export of St. Vincent during the period 1900 to 1965. It became an important commodity in colonial trade in the 1930s. As the sugar industry declined in the nineteenth century, cultivation of arrowroot was developed to fill the void. Since then, the area cultivated has declined steadily as other crops, particularly bananas, have gained wider acceptance by farmers. Evidence of its former importance is indicated by the ruins of the various magnificent 19th-century factories located in valleys on the St. Vincent mainland.
Arrowroot cultivation is now concentrated on farms located north of the Rabacca River, particularly in the Owia area. This is also the area where the population of C |
https://en.wikipedia.org/wiki/Red%20supergiant | Red supergiants (RSGs) are stars with a supergiant luminosity class (Yerkes class I) of spectral type K or M. They are the largest stars in the universe in terms of volume, although they are not the most massive or luminous. Betelgeuse and Antares A are the brightest and best known red supergiants (RSGs), indeed the only first magnitude red supergiant stars.
Classification
Stars are classified as supergiants on the basis of their spectral luminosity class. This system uses certain diagnostic spectral lines to estimate the surface gravity of a star, hence determining its size relative to its mass. Larger stars are more luminous at a given temperature and can now be grouped into bands of differing luminosity.
The luminosity differences between stars are most apparent at low temperatures, where giant stars are much brighter than main-sequence stars. Supergiants have the lowest surface gravities and hence are the largest and brightest at a particular temperature.
The Yerkes or Morgan-Keenan (MK) classification system is almost universal. It groups stars into five main luminosity groups designated by roman numerals:
I supergiant;
II bright giant;
III giant;
IV subgiant;
V dwarf (main sequence).
Specific to supergiants, the luminosity class is further divided into normal supergiants of class Ib and brightest supergiants of class Ia. The intermediate class Iab is also used. Exceptionally bright, low surface gravity, stars with strong indications of mass loss may be designated by luminosity class 0 (zero) although this is rarely seen. More often the designation Ia-0 will be used, and more commonly still Ia+. These hypergiant spectral classifications are very rarely applied to red supergiants, although the term red hypergiant is sometimes used for the most extended and unstable red supergiants like VY Canis Majoris and NML Cygni.
The "red" part of "red supergiant" refers to the cool temperature. Red supergiants are the coolest supergiants, M-type, and at le |
https://en.wikipedia.org/wiki/Privacy%20Impact%20Assessment | A Privacy Impact Assessment (PIA) is a process which assists organizations in identifying and managing the privacy risks arising from new projects, initiatives, systems, processes, strategies, policies, business relationships etc. It benefits various stakeholders, including the organization itself and the customers, in many ways. In the United States and Europe, policies have been issued to mandate and standardize privacy impact assessments.
Overview
A Privacy Impact Assessment is a type of impact assessment conducted by an organization (typically, a government agency or corporation with access to a large amount of sensitive, private data about individuals in or flowing through its system). The organization reviews its own processes to determine how these processes affect or might compromise the privacy of the individuals whose data it holds, collects, or processes. PIAs have been conducted by various sub-agencies of the U.S. Department of Homeland Security (DHS), and methods to conduct them have been standardized.
A PIA is typically designed to accomplish three main goals:
Ensure conformance with applicable legal, regulatory, and policy requirements for privacy.
Identify and evaluate the risks of privacy breaches or other incidents and effects.
Identify appropriate privacy controls to mitigate unacceptable risks.
A privacy impact report seeks to identify and record the essential components of any proposed system containing significant amounts of personal information and to establish how the privacy risks associated with that system can be managed. A PIA will sometimes go beyond an assessment of a "system" and consider critical "downstream" effects on people who are affected in some way by the proposal.
Purpose
Since PIA concerns an organization's ability to keep private information safe, the PIA should be completed whenever said organization is in possession of the personal information on its employees, clients, customers and business contacts etc. Althou |
https://en.wikipedia.org/wiki/Hamiltonian%20completion | The Hamiltonian completion problem is to find the minimal number of edges to add to a graph to make it Hamiltonian.
The problem is clearly NP-hard in the general case (since its solution gives an answer to the NP-complete problem of determining whether a given graph has a Hamiltonian cycle). The associated decision problem of determining whether K edges can be added to a given graph to produce a Hamiltonian graph is NP-complete.
Moreover, Hamiltonian completion belongs to the APX complexity class, i.e., it is unlikely that efficient constant ratio approximation algorithms exist for this problem.
The problem may be solved in polynomial time for certain classes of graphs, including series–parallel graphs and their generalizations, which include outerplanar graphs, as well as for a line graph of a tree
or a cactus graph.
Gamarnik et al. use a linear time algorithm for solving the problem on trees to study the asymptotic number of edges that must be added for sparse random graphs to make them Hamiltonian. |
https://en.wikipedia.org/wiki/Sekkotsu | or Judo therapy (柔道整復術) is the traditional Japanese art of bone-setting. It has been used in many Japanese martial arts and has developed alongside Judo (柔道) into a licensed medical practice somewhat resembling chiropractic in Japan today.
See also
Anma and shiatsu
Dit Da
Tui na
External links
Traditional Japanese medicine
Alternative medicine
Asian traditional medicine
Judo |
https://en.wikipedia.org/wiki/Pisano%20period | In number theory, the nth Pisano period, written as (n), is the period with which the sequence of Fibonacci numbers taken modulo n repeats. Pisano periods are named after Leonardo Pisano, better known as Fibonacci. The existence of periodic functions in Fibonacci numbers was noted by Joseph Louis Lagrange in 1774.
Definition
The Fibonacci numbers are the numbers in the integer sequence:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597, 2584, 4181, 6765, 10946, 17711, 28657, 46368, ...
defined by the recurrence relation
For any integer n, the sequence of Fibonacci numbers Fi taken modulo n is periodic.
The Pisano period, denoted (n), is the length of the period of this sequence. For example, the sequence of Fibonacci numbers modulo 3 begins:
0, 1, 1, 2, 0, 2, 2, 1, 0, 1, 1, 2, 0, 2, 2, 1, 0, 1, 1, 2, 0, 2, 2, 1, 0, ...
This sequence has period 8, so (3) = 8.
Properties
With the exception of (2) = 3, the Pisano period (n) is always even.
A simple proof of this can be given by observing that (n) is equal to the order of the Fibonacci matrix
in the general linear group GL2(ℤn) of invertible 2 by 2 matrices in the finite ring ℤn of integers modulo n. Since Q has determinant −1, the determinant of Q(n) is (−1)(n), and since this must equal 1 in ℤn, either n ≤ 2 or (n) is even.
If m and n are coprime, then (mn) is the least common multiple of (m) and (n), by the Chinese remainder theorem. For example, (3) = 8 and (4) = 6 imply (12) = 24. Thus the study of Pisano periods may be reduced to that of Pisano periods of prime powers q = pk, for k ≥ 1.
If p is prime, (pk) divides pk–1 (p). It is unknown if
for every prime p and integer k > 1. Any prime p providing a counterexample would necessarily be a Wall–Sun–Sun prime, and conversely every Wall–Sun–Sun prime p gives a counterexample (set k = 2).
So the study of Pisano periods may be further reduced to that of Pisano periods of primes. In this regard, two primes are anomalous. The prime 2 |
https://en.wikipedia.org/wiki/The%20Eidolon | The Eidolon was one of two games that were part of Lucasfilm Games' second wave in December 1985. The other was Koronis Rift. Both took advantage of the fractal technology developed for Rescue on Fractalus!, further enhancing it. In The Eidolon, Rescue'''s fractal mountains were turned upside down and became the inside of a cave.
In addition to common cassette formats, the Atari and Commodore 64 versions were supplied on a floppy disk. One side had the Atari version, and the other had the Commodore 64 version. The Atari version required an XL/XE with 64kB or more memory.
Plot
The player discovers the Eidolon, a strange 19th-century vehicle, in an abandoned laboratory. As the player investigates this device, he is accidentally transported to another dimension and is trapped in a vast, maze-like cave. The creatures in this cave, sensing the energy emanating from the Eidolon, are woken from a long slumber, and the player soon finds that his only chance of survival lies in this mysterious vehicle and its powerful energy weapon.
Gameplay
The objective of The Eidolon is to successfully navigate through all of the game's levels, defeating the dragon guardian at the end of each level. The player navigates through each maze and collects energy orbs, which come in four different colors (red, yellow, green and blue). Along the way, various enemies wake up and attack the Eidolon, attempting to absorb its energy. Some enemies also fire orbs at the Eidolon, of which all but the red orbs can be absorbed by pressing the space bar at the right time to replenish the Eidolon's limited energy.
Green orbs also have the power to transform other enemies into different kinds of enemies. Blue orbs can freeze enemies temporarily, giving the player a momentary advantage in a fight.
Each level contains three diamonds, each guarded by an enemy of a specific color. After defeating each of these enemies and collecting the diamonds, the player can proceed to the dragon that guards the exit. |
https://en.wikipedia.org/wiki/Recombinant%20virus | A recombinant virus may occur naturally or be produced by recombining pieces of DNA using recombinant DNA technology.
Synthetic recombination
This may be used to produce viral vaccines or gene therapy vectors.
Natural recombination
The term is also used to refer to naturally occurring recombination between virus genomes in a cell infected by more than one virus strain. This occurs either by Homologous recombination of the nucleic acid strands or by reassortment of genomic segments. Both these and mutation within the virus have been suggested as ways in which influenza and other viruses evolve. An example of a recombinant virus is Western equine encephalitis virus (WEE), which is a recombinant virus between two other closely related yet distinct encephalitis viruses. In addition, reassortment is most important for pandemic influenza viruses.
See also
Reassortment
Mutation
Chromosomal crossover |
https://en.wikipedia.org/wiki/Aerohive%20Networks | Aerohive Networks was an American multinational computer networking equipment company headquartered in Milpitas, California, with 17 additional offices worldwide. The company was founded in 2006 and provided wireless networking to medium-sized and larger businesses.
In 2012, Aerohive was listed on The Wall Street Journal's list of "Top 50 Start-Ups." The company raised around $105 million in venture capital funding before undergoing an IPO in March 2014.
On June 26, 2019, Extreme Networks announced its intent to acquire Aerohive for a purchase price of approximately $272 million. The acquisition closed on August 9, 2019.
History
Aerohive was founded in 2006 by Changming Liu. That same year, the company raised $4 million in series A round funding. In July 2007, the company raised an additional $20 million in series B round funding led by Kleiner Perkins Caufield & Byers. Aerohive completed a series C round of funding, raising $23.5 million to expand its sales and marketing strategy in March 2010. In 2011, the company acquired Pareto Networks, a cloud-based routing service, the acquisition allowed Aerohive to integrate Pareto's cloud management technology into its existing offerings. In September 2012, Aerohive raised $22.5 million in a series E round of funding and announced its plans to undergo an IPO the following year. The company raised an additional $10 million in funding as it prepared to go public, in 2013. On March 28, 2014, the company was listed on the New York Stock Exchange under the HIVE symbol. Aerohive joined Barack Obama's ConnectED initiative in October 2014, when it partnered with Apple Inc. and provided wireless connectivity to the schools receiving Apple products.
Aerohive announced that its devices would operate more seamlessly with Barracuda Networks security products in May 2015. In September 2015, the company announced a technology alliance with Juniper Networks. In January 2016, the company released HiveSchool, a learning application for |
https://en.wikipedia.org/wiki/Helminthiasis | Helminthiasis, also known as worm infection, is any macroparasitic disease of humans and other animals in which a part of the body is infected with parasitic worms, known as helminths. There are numerous species of these parasites, which are broadly classified into tapeworms, flukes, and roundworms. They often live in the gastrointestinal tract of their hosts, but they may also burrow into other organs, where they induce physiological damage.
Soil-transmitted helminthiasis and schistosomiasis are the most important helminthiases, and are among the neglected tropical diseases. These group of helminthiases have been targeted under the joint action of the world's leading pharmaceutical companies and non-governmental organizations through a project launched in 2012 called the London Declaration on Neglected Tropical Diseases, which aimed to control or eradicate certain neglected tropical diseases by 2020.
Helminthiasis has been found to result in poor birth outcome, poor cognitive development, poor school and work performance, poor socioeconomic development, and poverty. Chronic illness, malnutrition, and anemia are further examples of secondary effects.
Soil-transmitted helminthiases are responsible for parasitic infections in as much as a quarter of the human population worldwide. One well-known example of soil-transmitted helminthiases is ascariasis.
Types of parasitic helminths
Of all the known helminth species, the most important helminths with respect to understanding their transmission pathways, their control, inactivation and enumeration in samples of human excreta from dried feces, faecal sludge, wastewater, and sewage sludge are:
soil-transmitted helminths, including Ascaris lumbricoides (the most common worldwide), Trichuris trichiura, Necator americanus, Strongyloides stercoralis and Ancylostoma duodenale
Hymenolepis nana
Taenia saginata
Enterobius
Fasciola hepatica
Schistosoma mansoni
Toxocara canis
Toxocara cati
Helminthiases are classified a |
https://en.wikipedia.org/wiki/Peptide%20microarray | A peptide microarray (also commonly known as peptide chip or peptide epitope microarray) is a collection of peptides displayed on a solid surface, usually a glass or plastic chip. Peptide chips are used by scientists in biology, medicine and pharmacology to study binding properties and functionality and kinetics of protein-protein interactions in general. In basic research, peptide microarrays are often used to profile an enzyme (like kinase, phosphatase, protease, acetyltransferase, histone deacetylase etc.), to map an antibody epitope or to find key residues for protein binding. Practical applications are seromarker discovery, profiling of changing humoral immune responses of individual patients during disease progression, monitoring of therapeutic interventions, patient stratification and development of diagnostic tools and vaccines.
Principle
The assay principle of peptide microarrays is similar to an ELISA protocol.
The peptides (up to tens of thousands in several copies) are linked to the surface of a glass chip typically the size and shape of a microscope slide. This peptide chip can directly be incubated with a variety of different biological samples like purified enzymes or antibodies, patient or animal sera, cell lysates and then be detected through a label-dependent fashion, for example, by a primary antibody that targets the bound protein or modified substrates. After several washing steps a secondary antibody with the needed specificity (e.g. anti IgG human/mouse or anti phosphotyrosine or anti myc) is applied. Usually, the secondary antibody is tagged by a fluorescence label that can be detected by a fluorescence scanner. Other label-dependent detection methods includes chemiluminescence, colorimetric or autoradiography.
Label-dependent assays are rapid and convenient to perform, but risk giving rise to false positive and negative results. More recently, label-free detection including surface plasmon resonance (SPR) spectroscopy, mass spectrometry ( |
https://en.wikipedia.org/wiki/Universal%20dielectric%20response | In physics and electrical engineering, the universal dielectric response, or UDR, refers to the observed emergent behaviour of the dielectric properties exhibited by diverse solid state systems. In particular this widely observed response involves power law scaling of dielectric properties with frequency under conditions of alternating current, AC. First defined in a landmark article by A. K. Jonscher in Nature published in 1977, the origins of the UDR were attributed to the dominance of many-body interactions in systems, and their analogous RC network equivalence.
The universal dielectric response manifests in the variation of AC Conductivity with frequency and is most often observed in complex systems consisting of multiple phases of similar or dissimilar materials. Such systems, which can be called heterogenous or composite materials, can be described from a dielectric perspective as a large network consisting of resistor and capacitor elements, known also as an RC network. At low and high frequencies, the dielectric response of heterogeneous materials is governed by percolation pathways. If a heterogeneous material is represented by a network in which more than 50% of the elements are capacitors, percolation through capacitor elements will occur. This percolation results in conductivity at high and low frequencies that is directly proportional to frequency. Conversely, if the fraction of capacitor elements in the representative RC network (Pc) is lower than 0.5, dielectric behavior at low and high frequency regimes is independent of frequency. At intermediate frequencies, a very broad range of heterogeneous materials show a well-defined emergent region, in which power law correlation of admittance to frequency is observed. The power law emergent region is the key feature of the UDR. In materials or systems exhibiting UDR, the overall dielectric response from high to low frequencies is symmetrical, being centered at the middle point of the emergent region, whic |
https://en.wikipedia.org/wiki/Doppler%20imaging | Inhomogeneous structures on stellar surfaces, i.e. temperature differences, chemical composition or magnetic fields, create characteristic distortions in the spectral lines due to the Doppler effect. These distortions will move across spectral line profiles due to the stellar rotation. The technique to reconstruct these structures on the stellar surface is called Doppler-imaging, often based on the maximum entropy image reconstruction to find the stellar image. This technique gives the smoothest and simplest image that is consistent with observations.
To understand the magnetic field and activity of stars, studies of the Sun are not sufficient; studies of other stars are necessary. Periodic changes in brightness have long been observed in stars which indicate cooler or brighter starspots on the surface. These spots are larger than the ones on the Sun, covering up to 20% of the star. Spots with similar size as the ones on the Sun would hardly give rise to changes in intensity. In order to understand the magnetic field structure of a star, it is not enough to know that spots exist because their location and extent are also important.
History
Doppler imaging was first used to map chemical peculiarities on the surface of Ap stars. For mapping starspots it was first used by Steven Vogt and Donald Penrod in 1983, when they demonstrated that signatures of starspots were observable in the line profiles of the active binary star HR 1099 (V711 Tau); from this they could derive an image of the stellar surface.
Criteria for Doppler Imaging
In order to be able to use the Doppler imaging technique the star needs to fulfill some specific criteria.
The stellar rotation needs to be the dominating effect broadening spectral lines, .
The projected equatorial rotational velocity should be at least . If the velocity is lower, spatial resolution is degraded, but variations in the line profile can still give information of areas with higher velocities. For very high velocities , |
https://en.wikipedia.org/wiki/Nilcurve | In mathematics, a nilcurve is a pointed stable curve over a finite field with an indigenous bundle whose p-curvature is square nilpotent. Nilcurves were introduced by as a central concept in his theory of p-adic Teichmüller theory.
The nilcurves form a stack over the moduli stack of stable genus g curves with r marked points in characteristic p, of degree
p3g–3+r. |
https://en.wikipedia.org/wiki/Quasistatic%20loading | In solid mechanics, quasistatic loading refers to loading where inertial effects are negligible. In other words, time and inertial force are irrelevant. |
https://en.wikipedia.org/wiki/Superconducting%20radio%20frequency | Superconducting radio frequency (SRF) science and technology involves the application of electrical superconductors to radio frequency devices. The ultra-low electrical resistivity of a superconducting material allows an RF resonator to obtain an extremely high quality factor, Q. For example, it is commonplace for a 1.3 GHz niobium SRF resonant cavity at 1.8 kelvins to obtain a quality factor of Q=5×1010. Such a very high Q resonator stores energy with very low loss and narrow bandwidth. These properties can be exploited for a variety of applications, including the construction of high-performance particle accelerator structures.
Introduction
The amount of loss in an SRF resonant cavity is so minute that it is often explained with the following comparison: Galileo Galilei (1564–1642) was one of the first investigators of pendulous motion, a simple form of mechanical resonance. Had Galileo experimented with a 1 Hz resonator with a quality factor Q typical of today's SRF cavities and left it swinging in an entombed lab since the early 17th century, that pendulum would still be swinging today with about half of its original amplitude.
The most common application of superconducting RF is in particle accelerators. Accelerators typically use resonant RF cavities formed from or coated with superconducting materials. Electromagnetic fields are excited in the cavity by coupling in an RF source with an antenna. When the RF fed by the antenna is the same as that of a cavity mode, the resonant fields build to high amplitudes. Charged particles passing through apertures in the cavity are then accelerated by the electric fields and deflected by the magnetic fields. The resonant frequency driven in SRF cavities typically ranges from 200 MHz to 3 GHz, depending on the particle species to be accelerated.
The most common fabrication technology for such SRF cavities is to form thin walled (1–3 mm) shell components from high purity niobium sheets by stamping. These shell compon |
https://en.wikipedia.org/wiki/Left%20gastric%20vein | The left gastric vein (or coronary vein) is a vein that derives from tributaries draining the lesser curvature of the stomach.
Structure
The left gastric vein runs from right to left along the lesser curvature of the stomach. It passes to the esophageal opening of the stomach, where it receives some esophageal veins. It then turns backward and passes from left to right behind the omental bursa. It drains into the portal vein near the superior border of the pancreas.
Function
The left gastric vein drains deoxygenated blood from the lesser curvature of the stomach. It also acts as collaterals between the portal vein and the systemic venous system of the lower esophagus (azygos vein).
Clinical significance
The esophageal branch of the left gastric vein drains into the azygos vein. In cases of portal hypertension, this communication allows for blood to bypass the portal vein and reach systemic circulation. As a result of this anastomosis, development of esophageal and paraesophageal varices is possible.
See also
Portacaval anastomosis
Right gastric vein |
https://en.wikipedia.org/wiki/Mark%20Kisin | Mark Kisin is a mathematician known for work in algebraic number theory and arithmetic geometry. In particular, he is known for his contributions to the study of p-adic representations and p-adic cohomology.
Born in Vilnius, Lithuania and raised from the age of five in Melbourne, Australia, he won a silver medal at the International Mathematical Olympiad in 1989 and received his B.Sc. from Monash University in 1991. He received his Ph.D. from Princeton University in 1998 under the direction of Nick Katz. From 1998 to 2001 he was a Research Fellow at the University of Sydney, after which he spent three years at the University of Münster.
After six years at the University of Chicago, Kisin took the post in 2009 of professor of mathematics at Harvard University.
He was elected a Fellow of the Royal Society in 2008. He gave an invited talk at the International Congress of Mathematicians in 2010, on the topic of "Number Theory". In 2012 he became a fellow of the American Mathematical Society. He was elected to the American Academy of Arts and Sciences in 2022. |
https://en.wikipedia.org/wiki/Vanessa%20atalanta | Vanessa atalanta, the red admiral or, previously, the red admirable, is a well-characterized, medium-sized butterfly with black wings, red bands, and white spots. It has a wingspan of about . It was first described by Carl Linnaeus in his 1758 10th edition of Systema Naturae. The red admiral is widely distributed across temperate regions of North Africa, the Americas, Europe, Asia, and the Caribbean. It resides in warmer areas, but migrates north in spring and sometimes again in autumn. Typically found in moist woodlands, the red admiral caterpillar's primary host plant is the stinging nettle (Urtica dioica); it can also be found on the false nettle (Boehmeria cylindrica). The adult butterfly drinks from flowering plants like Buddleia and overripe fruit. Red admirals are territorial; females will only mate with males that hold territory. Males with superior flight abilities are more likely to successfully court females. It is known as an unusually calm butterfly, often allowing observation at a very close distance before flying away, also landing on and using humans as perches.
Geographic range
The red admiral is found in temperate regions of North Africa, North and Central America, Europe, Asia, and island regions of Hawaii, and the Caribbean.
Description
The forewing of this butterfly bears on a black ground an oblique vermilion band
and a group of white subapical spots. On the hindwing the larger portion of the distal margin is red, with a row of small black spots and at the anal angle an elongate blue spot. The underside is partly variegated with blue; the forewing is on the whole similar in markings to the upper, while the hindwing is brightly variegated and clouded, bearing black markings, of which those in the cell resemble a figure (on the left wing 18 or 98, on the right 81 or 89); in the middle of the costal area there is a pale patch and in the distal marginal area a row of ocellus-like spots. Sometimes, especially in the female, the red band of the for |
https://en.wikipedia.org/wiki/Poly%28methyl%20methacrylate%29 | Poly(methyl methacrylate) (PMMA) is the synthetic polymer derived from methyl methacrylate. It is used as an engineering plastic, and it is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Hesalite, Plexiglas, Acrylite, Lucite, and Perspex, among several others (see below). This plastic is often used in sheet form as a lightweight or shatter-resistant alternative to glass. It can also be used as a casting resin, in inks and coatings, and for many other purposes.
It is often technically classified as a type of glass, in that it is a non-crystalline vitreous substance—hence its occasional historic designation as acrylic glass.
History
The first acrylic acid was created in 1843. Methacrylic acid, derived from acrylic acid, was formulated in 1865. The reaction between methacrylic acid and methanol results in the ester methyl methacrylate.
It was developed in 1928 in several different laboratories by many chemists, such as William R. Conn, Otto Röhm, and Walter Bauer, and first brought to market in 1933 by German Röhm & Haas AG (as of January 2019, part of Evonik Industries) and its partner and former U.S. affiliate Rohm and Haas Company under the trademark Plexiglas.
Polymethyl methacrylate was discovered in the early 1930s by British chemists Rowland Hill and John Crawford at Imperial Chemical Industries (ICI) in the United Kingdom. ICI registered the product under the trademark Perspex. About the same time, chemist and industrialist Otto Röhm of Röhm and Haas AG in Germany attempted to produce safety glass by polymerizing methyl methacrylate between two layers of glass. The polymer separated from the glass as a clear plastic sheet, which Röhm gave the trademarked name Plexiglas in 1933. Both Perspex and Plexiglas were commercialized in the late 1930s. In the United States, E.I. du Pont de Nemours & Company (now DuPont Company) subsequently introduced its own product under the trademark L |
https://en.wikipedia.org/wiki/Hypercomputation | Hypercomputation or super-Turing computation is a set of models of computation that can provide outputs that are not Turing-computable. For example, a machine that could solve the halting problem would be a hypercomputer; so too would one that can correctly evaluate every statement in Peano arithmetic.
The Church–Turing thesis states that any "computable" function that can be computed by a mathematician with a pen and paper using a finite set of simple algorithms, can be computed by a Turing machine. Hypercomputers compute functions that a Turing machine cannot and which are, hence, not computable in the Church–Turing sense.
Technically, the output of a random Turing machine is uncomputable; however, most hypercomputing literature focuses instead on the computation of deterministic, rather than random, uncomputable functions.
History
A computational model going beyond Turing machines was introduced by Alan Turing in his 1938 PhD dissertation Systems of Logic Based on Ordinals. This paper investigated mathematical systems in which an oracle was available, which could compute a single arbitrary (non-recursive) function from naturals to naturals. He used this device to prove that even in those more powerful systems, undecidability is still present. Turing's oracle machines are mathematical abstractions, and are not physically realizable.
State space
In a sense, most functions are uncomputable: there are computable functions, but there are an uncountable number () of possible super-Turing functions.
Models
Hypercomputer models range from useful but probably unrealizable (such as Turing's original oracle machines), to less-useful random-function generators that are more plausibly "realizable" (such as a random Turing machine).
Uncomputable inputs or black-box components
A system granted knowledge of the uncomputable, oracular Chaitin's constant (a number with an infinite sequence of digits that encode the solution to the halting problem) as an input can solve a l |
https://en.wikipedia.org/wiki/Quadratics | Quadratics is a six-part Canadian instructional television series produced by TVOntario in 1993. The miniseries is part of the Concepts in Mathematics series. The program uses computer animation to demonstrate quadratic equations and their corresponding functions in the Cartesian coordinate system.
Synopsis
Each program involves two robots, Edie and Charon, who work on an assembly line in a high-tech factory. The robots discuss their desire to learn about quadratic equations, and they are subsequently provided with lessons that further their education.
Episodes |
https://en.wikipedia.org/wiki/Flag%20of%20Buffalo%2C%20New%20York | The municipal flag of Buffalo is the official banner of the city of Buffalo, New York. The navy blue flag contains a large central emblem consisting of the city seal with 13 "electric flashes" (depicted as lightning bolts) and interspaced 5-pointed white stars emanating from it.
History
Following a request from New York City publisher, the Julius Bien Company, to provide a copy of the banner graphic for a work depicting the flags of large municipalities, Mayor Louis P. Fuhrmann and Commissioner of Public Works, Francis G. Ward, proposed a design. The city's first flag was composed of the city seal superimposed on the state coat-of-arms in blue over a buff-colored background.
1912 proposal
From Common Council Proceedings, June 3, 1912:
To the left center a lighthouse on pier with ship passing it into harbor. To the lower right canal boat passing into canal to the right surrounded in circle by the legend "City of Buffalo, Incorporated 1832."
The municipalities of the United States having as a rule a Municipal Flag, examinination shows the general practice to be the use of the Coat of Arms of the City or the Coat of Arms of the State upon which is superimposed the seal of the City.
In accordance with the latter rule we submit as a design for the Municipal Flag of the City of Buffalo, the following:
"The Coat of Arms of the State of New York with the Seal of the City of Buffalo superimposed upon the shield of the same all in blue upon the field of the flag in Continental buff."
(Despite the assertion above, no such "general practice" of superimposing city seals over state seals has been documented.)
Flag seal
Though the Common Council passed an ordinance describing the official seal of the city and its flag, the seal described was not the one included on the banner. At the time there were several seals being used by various city officials. The seal depicted on the flag was actually the seal being used by the Mayor. There are a few differences, the most |
https://en.wikipedia.org/wiki/Noisy-storage%20model | The noisy-storage model refers to a cryptographic model employed in quantum cryptography. It assumes that the quantum memory device of an attacker (adversary) trying to break the protocol is imperfect (noisy).
The main goal of this model is to enable the secure implementation of two-party cryptographic primitives, such as bit commitment, oblivious transfer and secure identification.
Motivation
Quantum communication has proven to be extremely useful when it comes to distributing encryption keys. It allows two distant parties Alice and Bob to expand a small initial secret key into an arbitrarily long secret key by sending qubits (quantum bits) to each other. Most importantly, it can be shown that any eavesdropper trying to listen into their communication cannot intercept any information about the long key. This is known as quantum key distribution (QKD).
Yet, it has been shown that even quantum communication does not allow the secure implementation of many other two-party cryptographic tasks. These all form instances of secure function evaluation. An example is oblivious transfer. What sets these tasks apart from key distribution is that they aim to solve problems between two parties, Alice and Bob, who do not trust each other. That is, there is no outside party like an eavesdropper, only Alice and Bob. Intuitively, it is this lack of trust that makes the problem hard. Unlike in quantum key distribution, Alice and Bob cannot collaborate to try and detect any eavesdropping activity. Instead, each party has to fend for himself.
Since tasks like secure identification are of practical interest, one is willing to make assumptions on how powerful the adversary can be. Security then holds as long as these assumptions are satisfied. In classical cryptography, i.e., without the use of quantum tools, most of these are computational assumptions. Such assumptions consists of two parts. First, one assumes that a particular problem is difficult to solve. For example, one might |
https://en.wikipedia.org/wiki/PRISM%20model%20checker | PRISM is a probabilistic model checker, a formal verification software tool for the modelling and analysis of systems that exhibit probabilistic behaviour. One source of such systems is the use of randomization, for example in communication protocols like Bluetooth and FireWire, or in security protocols such as Crowds and Onion routing. Stochastic behaviour also arises in many other computer systems, for example due to equipment failures or unpredictable communication delays. Yet another class of systems amenable to this kind of analysis are biochemical reaction networks.
PRISM can be used to analyse several different types of probabilistic models, including discrete-time Markov chains, continuous-time Markov chains, Markov decision processes and probabilistic extensions of the timed automata formalism. Properties to be verified against these models are expressed in probabilistic extensions of temporal logic.
Development of PRISM is primarily carried out at the University of Birmingham and the University of Oxford. The tool is open-source software, released under the GNU General Public License. PRISM has been selected for the Google Summer of Code programme in 2013 and 2014. |
https://en.wikipedia.org/wiki/RAF%20raid%20on%20La%20Caine%20%281944%29 | The RAF raid on La Caine (1944) was an attack on 10 June 1944 by aircraft of the Royal Air Force against the headquarters of during Operation Overlord the Allied invasion of France, which led the German Panzer divisions in France and Belgium. The headquarters had recently taken over the château at La Caine, about to the south-west of the city of Caen, north of Thury-Harcourt.
Squadrons of North American B-25 Mitchell medium bombers and Hawker Typhoon fighter bombers of the RAF Second Tactical Air Force attacked the château and its grounds with bombs and air-to-ground rockets. Eighteen staff officers were killed in the attack and the commander, Leo Geyr von Schweppenburg was wounded.
A German armoured counter-offensive by against the Allied beachhead was postponed and then cancelled after the destruction of the headquarters. Command of Panzer divisions in the area was transferred to the headquarters; the remnants of the HQ was withdrawn to Paris and did not return to action until 28 June.
Background
(Field Marshal) Gerd von Rundstedt, ( the commander of German forces in western Europe) established , (commanded by Leo Geyr von Schweppenburg from 19 November 1943 to 4 July 1944) as a headquarters for the administration and training of the seven Panzer divisions based in northern France and Belgium. The organisation was also to command the Panzer divisions as a strategic reserve during the anticipated Allied invasion from Britain. On 9 June 1944, three days after the beginning of Operation Overlord, the invasion of France by the Western Allies, Erwin Rommel, commander of (Army Group B) with responsibility for the defence of northern France, drove to the HQ of and gave orders for a counter-offensive against the Allied landings in Normandy.
Allied monitoring of German communications
The Government Code and Cypher School (GC&CS) code-breaking organisation at Bletchley Park read German radio signals encrypted by the Enigma cypher machine and was part of the |
https://en.wikipedia.org/wiki/Ribosomal%20pause | Ribosomal pause refers to the queueing or stacking of ribosomes during translation of the nucleotide sequence of mRNA transcripts. These transcripts are decoded and converted into an amino acid sequence during protein synthesis by ribosomes. Due to the pause sites of some mRNA's, there is a disturbance caused in translation. Ribosomal pausing occurs in both eukaryotes and prokaryotes. A more severe pause is known as a ribosomal stall.
It's been known since the 1980s that different mRNAs are translated at different rates. The main reason for these differences was thought to be the concentration of varieties of rare tRNAs limiting the rate at which some transcripts could be decoded. However, with research techniques such as ribosome profiling, it was found that at certain sites there were higher concentrations of ribosomes than average, and these pause sites were tested with specific codons. No link was found between the occupancy of specific codons and amount of their tRNAs. Thus, the early findings about rare tRNAs causing pause sites doesn't seem plausible.
Two techniques can localize the ribosomal pause site in vivo; a micrococcal nuclease protection assay and isolation of polysomal transcript. Isolation of polysomal transcripts occurs by centrifuging tissue extracts through a sucrose cushion with translation elongation inhibitors, for example cycloheximide.
Ribosome pausing can be detected during preprolactin synthesis on free polysomes, when the ribosome is paused the other ribosomes are tightly stacked together. When the ribosome pauses, during translation, the fragments that started to translate before the pause took place are overrepresented. However, along with the mRNA if the ribosome pauses then specific bands will be improved in the trailing edge of the ribosome.
Some of the elongation inhibitors, such as: cycloheximide (in eukaryotes) or chloramphenicol, cause the ribosomes to pause and to accumulate in the start codons. Elongation Factor P regulates |
https://en.wikipedia.org/wiki/Finger%20binary | Finger binary is a system for counting and displaying binary numbers on the fingers of either or both hands. Each finger represents one binary digit or bit. This allows counting from zero to 31 using the fingers of one hand, or 1023 using both: that is, up to 25−1 or 210−1 respectively.
Modern computers typically store values as some whole number of 8-bit bytes, making the fingers of both hands together equivalent to 1 bytes of storage—in contrast to less than half a byte when using ten fingers to count up to 10.
Mechanics
In the binary number system, each numerical digit has two possible states (0 or 1) and each successive digit represents an increasing power of two.
Note: What follows is but one of several possible schemes for assigning the values 1, 2, 4, 8, 16, etc. to fingers, not necessarily the best. (see below the illustrations.): The rightmost digit represents two to the zeroth power (i.e., it is the "ones digit"); the digit to its left represents two to the first power (the "twos digit"); the next digit to the left represents two to the second power (the "fours digit"); and so on. (The decimal number system is essentially the same, only that powers of ten are used: "ones digit", "tens digit" "hundreds digit", etc.)
It is possible to use anatomical digits to represent numerical digits by using a raised finger to represent a binary digit in the "1" state and a lowered finger to represent it in the "0" state. Each successive finger represents a higher power of two.
With palms oriented toward the counter's face, the values for when only the right hand is used are:
When only the left hand is used:
When both hands are used:
And, alternately, with the palms oriented away from the counter:
The values of each raised finger are added together to arrive at a total number. In the one-handed version, all fingers raised is thus 31 (16 + 8 + 4 + 2 + 1), and all fingers lowered (a fist) is 0. In the two-handed system, all fingers raised is 1,023 (512 + 256 + 1 |
https://en.wikipedia.org/wiki/Commutative%20property | In mathematics, a binary operation is commutative if changing the order of the operands does not change the result. It is a fundamental property of many binary operations, and many mathematical proofs depend on it. Most familiar as the name of the property that says something like or , the property can also be used in more advanced settings. The name is needed because there are operations, such as division and subtraction, that do not have it (for example, ); such operations are not commutative, and so are referred to as noncommutative operations. The idea that simple operations, such as the multiplication and addition of numbers, are commutative was for many years implicitly assumed. Thus, this property was not named until the 19th century, when mathematics started to become formalized. A similar property exists for binary relations; a binary relation is said to be symmetric if the relation applies regardless of the order of its operands; for example, equality is symmetric as two equal mathematical objects are equal regardless of their order.
Mathematical definitions
A binary operation on a set S is called commutative if
In other words, an operation is commutative if every two elements commute. An operation that does not satisfy the above property is called noncommutative.
One says that commutes with or that and commute under if
That is, a specific pair of elements may commute even if the operation is (strictly) noncommutative.
Examples
Commutative operations
Addition and multiplication are commutative in most number systems, and, in particular, between natural numbers, integers, rational numbers, real numbers and complex numbers. This is also true in every field.
Addition is commutative in every vector space and in every algebra.
Union and intersection are commutative operations on sets.
"And" and "or" are commutative logical operations.
Noncommutative operations
Some noncommutative binary operations:
Division, subtraction, and exponentiat |
https://en.wikipedia.org/wiki/Axostyle | An axostyle is a sheet of microtubules found in certain protists. It arises from the bases of the flagella, sometimes projecting beyond the end of the cell, and is often flexible or contractile, and so may be involved in movement and provides support for the cell. Axostyles originate in association with a flagellar microtubular root and occur in two groups, the oxymonads and parabasalids; they have different structures and are not homologous. Within Trichomonads the axostyle has been theorised to participate in locomotion and cell adhesion, but also karyokinesis during cell division. |
https://en.wikipedia.org/wiki/Symbols%20of%20British%20Columbia | British Columbia is Canada's westernmost province, and has established several provincial symbols.
Official symbols
Other Symbols |
https://en.wikipedia.org/wiki/Omphalotus%20olivascens | Omphalotus olivascens, commonly known as the western jack-o'-lantern mushroom, is an orange to brown-colored gilled poisonous mushroom native to California and Mexico. It is sometimes mistaken for chanterelles.
Taxonomy
The fungus was described as new to science in 1976 by American mycologists Howard E. Bigelow, Orson K. Miller Jr., and Harry D. Thiers. A subspecies with blue flesh, O. olivascens var. indigo, was described growing on live oak in Baja California, Mexico.
Description
To an untrained eye, O. olivascens appears similar to some chanterelles, but unlike the chanterelle, the jack-o'-lantern mushroom has true, blade-like gills (rather than ridges) and it can have olive coloration that chanterelles lack; also, Omphalotus species are saprotrophic, grow directly on wood, and are bioluminescent.
The cap is wide. The stalks are long and wide. The spores are white to pale yellow.
Ecology
A saprobe or parasite, O. nidiformis is nonspecific in its needs and is compatible with a wide variety of hosts.
Omphalotus species cause a white rot by breaking down lignin in their tree hosts.
Biochemistry
The jack o'lantern mushroom is poisonous; while not lethal, consuming this mushroom leads to very severe cramps, vomiting, and diarrhea.
The toxic ingredient of many species of Omphalotus is a sesquiterpene compound known as illudin S. This, along with illudin M, have been identified in O. nidiformis. The two illudins are common to the genus Omphalotus and not found in any other basidiomycete mushroom.
Similar species
Several Omphalotus species with similar bioluminescent properties occur worldwide, all of which are presumed poisonous. The best known are the North American jack o'lantern mushroom (O. olearius) and the tsukiyotake (O. japonicus (Kawam.) Kirchm. & O.K. Mill. (formerly known as Lampteromyces japonicus (Kawam.) Sing.), found in Japan and eastern Asia. Molecular analysis shows the jack-o'-lantern to be most closely related to the ghost fungus Omphalotu |
https://en.wikipedia.org/wiki/Metatrochophore | A metatrochophore (;) is a type of larva developed from the trochophore larva of a polychaete annelid.
Metatrochophores have a number of features trochophores lack, including eyespots and segments. |
https://en.wikipedia.org/wiki/Alternative%20mating%20strategy | An alternative mating strategy is a strategy used by male or female animals, often with distinct phenotypes, that differs from the prevailing mating strategy of their sex. Such strategies are diverse and variable both across and within species. Animal sexual behaviour and mate choice directly affect social structure and relationships in many different mating systems, whether monogamous, polygamous, polyandrous, or polygynous. Though males and females in a given population typically employ a predominant reproductive strategy based on the overarching mating system, individuals of the same sex often use different mating strategies. Among some reptiles, frogs and fish, large males defend females, while small males may use sneaking tactics to mate without being noticed.
Strategies and selection
Alternative mating strategies have been observed among both male and female animals. Most typically, alternative strategies will be adopted in the face of competition within a sex, especially in species that mate multiply. In these scenarios, some individuals will adopt very different mating strategies to achieve reproductive success. The result over time will be a variety of evolutionarily stable strategies and phenotypes, consisting of both conventional individuals and unconventional individuals who mate through alternative means. Successful strategies are maintained through sexual selection.
In many cases, the coexistence of alternative and traditional mating strategies will both maximize the average fitness of the sex in question and be evolutionarily stable for a population. However, the utilization of alternative mating strategies may oscillate as a result of varying reproductive conditions, such as the availability of potential mates. Under changing circumstances, the existence of a variety of strategies allows individuals to choose the conditional behaviour that will currently maximize their fitness.
Selection
Conventional and alternative mating behaviours arise thr |
https://en.wikipedia.org/wiki/Monosodium%20citrate | Monosodium citrate, more correctly, sodium dihydrogen citrate (Latin: ), is an acid salt of citric acid. Disodium citrate and trisodium citrate are also known. It can be prepared by partial neutralisation of citric acid with an aqueous solution of sodium bicarbonate or carbonate. It has a slightly acidic taste.
NaHCO3 + C6H8O7 → NaC6H7O7 + CO2 + H2O
Na2CO3 + 2C6H8O7 → 2NaC6H7O7 + CO2 + H2O
It is highly soluble in water and practically insoluble in ethanol. Monosodium citrate is used as an anticoagulant in donated blood. It is used as an alkalinizing agent to prevent kidney stone disease. The crystals form as nearly perfect cubes. |
https://en.wikipedia.org/wiki/Christian%20views%20on%20cloning | Christians take multiple positions in the debate on the morality of human cloning. Since Dolly the sheep was successfully cloned on 5 July 1996, and the possibility of cloning humans became a reality, Christian leaders have been pressed to take an ethical stance on its morality. While many Christians tend to disagree with the practice, such as Roman Catholics and a majority of fundamentalist pastors, including Southern Baptists, the views taken by various other Christian denominations are diverse and often conflicting. It is hard to pinpoint any one, definite stance of the Christian religion, since there are so many Christian denominations and so few official statements from each of them concerning the morality of human cloning.
There are certain Protestant denominations that do not disagree with the acceptability of human cloning. Mary Seller, for example, a member of the Church of England's Board of Social Responsibility and a professor of developmental genetics, states, "Cloning, like all science, must be used responsibly. Cloning humans is not desirable. But cloning sheep has its uses." On the other hand, according to a survey of Christian fundamentalist pastors, responses indicated a "common account of human cloning as primarily reproductive in nature, proscribed by its violation of God's will and role." Many of these pastors acknowledged the reason for this violation being rooted in the religiously motivated view that human cloning is an example of scientists 'playing God.'" It is not only this that many Christians are concerned about, however; other concerns include whether the dignity of the human person is overlooked, as well as the role of the parents as co-creators. All of these things may contribute to why many fundamentalist Christian pastors see human reproductive cloning as simply "forbidden territory."
Understanding cloning
Some scientists do argue that the plurality of views comes from the differing understandings of what exactly human cloning is |
https://en.wikipedia.org/wiki/Instability | In dynamical systems instability means that some of the outputs or internal states increase with time, without bounds. Not all systems that are not stable are unstable; systems can also be marginally stable or exhibit limit cycle behavior.
In structural engineering, a structural beam or column can become unstable when excessive compressive load is applied. Beyond a certain threshold, structural deflections magnify stresses, which in turn increases deflections. This can take the form of buckling or crippling. The general field of study is called structural stability.
Atmospheric instability is a major component of all weather systems on Earth.
Instability in control systems
In the theory of dynamical systems, a state variable in a system is said to be unstable if it evolves without bounds. A system itself is said to be unstable if at least one of its state variables is unstable.
In continuous time control theory, a system is unstable if any of the roots of its characteristic equation has real part greater than zero (or if zero is a repeated root). This is equivalent to any of the eigenvalues of the state matrix having either real part greater than zero, or, for the eigenvalues on the imaginary axis, the algebraic multiplicity being larger than the geometric multiplicity. The equivalent condition in discrete time is that at least one of the eigenvalues is greater than 1 in absolute value, or that two or more eigenvalues are equal and of unit absolute value.
Instability in solid mechanics
Buckling
Elastic instability
Drucker stability of a nonlinear constitutive model
Biot instability (surface wrinkling in elastomers)
Baroclinic instability
Fluid instabilities
Fluid instabilities occur in liquids, gases and plasmas, and are often characterized by the shape that form; they are studied in fluid dynamics and magnetohydrodynamics. Fluid instabilities include:
Ballooning instability (some analogy to the Rayleigh–Taylor instability); found in the magnetosphe |
https://en.wikipedia.org/wiki/Scrapie | Scrapie () is a fatal, degenerative disease affecting the nervous systems of sheep and goats. It is one of several transmissible spongiform encephalopathies (TSEs), and as such it is thought to be caused by a prion. Scrapie has been known since at least 1732 and does not appear to be transmissible to humans. However, it has been found to be experimentally transmissible to humanised transgenic mice and non-human primates.
The name scrapie is derived from one of the clinical signs of the condition, wherein affected animals will compulsively scrape off their fleeces against rocks, trees or fences. The disease apparently causes an itching sensation in the animals. Other clinical signs include excessive lip smacking, altered gaits and convulsive collapse.
Scrapie is infectious and transmissible among conspecifics, so one of the most common ways to contain it (since it is incurable) is to quarantine and kill those affected. However, scrapie tends to persist in flocks and can also arise apparently spontaneously in flocks that have not previously had cases of the disease. The mechanism of transmission between animals and other aspects of the biology of the disease are only poorly understood, and are active areas of research. Recent studies suggest prions may be spread through urine and persist in the environment for decades.
Scrapie usually affects sheep around three to five years of age. The potential for transmission at birth and from contact with placental tissues is apparent.
Regulation
The disease has been notifiable in the EU since 1993, but unlike bovine spongiform encephalopathy (BSE, commonly known as mad cow disease), there was no evidence as of 1999 to suggest that scrapie is a risk to human health. In July 2003, a Canadian Food Inspection Agency officer said that while scrapie shows up every year on Canadian farms, "We've had a lot of experience with scrapie and there's never been a link between scrapie and human illness." As of 2004, the USDA made no menti |
https://en.wikipedia.org/wiki/Rayleigh%20length | In optics and especially laser science, the Rayleigh length or Rayleigh range, , is the distance along the propagation direction of a beam from the waist to the place where the area of the cross section is doubled. A related parameter is the confocal parameter, b, which is twice the Rayleigh length. The Rayleigh length is particularly important when beams are modeled as Gaussian beams.
Explanation
For a Gaussian beam propagating in free space along the axis with wave number , the Rayleigh length is given by
where is the wavelength (the vacuum wavelength divided by , the index of refraction) and is the beam waist, the radial size of the beam at its narrowest point. This equation and those that follow assume that the waist is not extraordinarily small; .
The radius of the beam at a distance from the waist is
The minimum value of occurs at , by definition. At distance from the beam waist, the beam radius is increased by a factor and the cross sectional area by 2.
Related quantities
The total angular spread of a Gaussian beam in radians is related to the Rayleigh length by
The diameter of the beam at its waist (focus spot size) is given by
.
These equations are valid within the limits of the paraxial approximation. For beams with much larger divergence the Gaussian beam model is no longer accurate and a physical optics analysis is required.
See also
Beam divergence
Beam parameter product
Gaussian function
Electromagnetic wave equation
John Strutt, 3rd Baron Rayleigh
Robert Strutt, 4th Baron Rayleigh
Depth of field |
https://en.wikipedia.org/wiki/Certificate%20authority | In cryptography, a certificate authority or certification authority (CA) is an entity that stores, signs, and issues digital certificates. A digital certificate certifies the ownership of a public key by the named subject of the certificate. This allows others (relying parties) to rely upon signatures or on assertions made about the private key that corresponds to the certified public key. A CA acts as a trusted third party—trusted both by the subject (owner) of the certificate and by the party relying upon the certificate. The format of these certificates is specified by the X.509 or EMV standard.
One particularly common use for certificate authorities is to sign certificates used in HTTPS, the secure browsing protocol for the World Wide Web. Another common use is in issuing identity cards by national governments for use in electronically signing documents.
Overview
Trusted certificates can be used to create secure connections to a server via the Internet. A certificate is essential in order to circumvent a malicious party which happens to be on the route to a target server which acts as if it were the target. Such a scenario is commonly referred to as a man-in-the-middle attack. The client uses the CA certificate to authenticate the CA signature on the server certificate, as part of the authorizations before launching a secure connection. Usually, client software—for example, browsers—include a set of trusted CA certificates. This makes sense, as many users need to trust their client software. A malicious or compromised client can skip any security check and still fool its users into believing otherwise.
The clients of a CA are server supervisors who call for a certificate that their servers will bestow to users. Commercial CAs charge money to issue certificates, and their customers anticipate the CA's certificate to be contained within the majority of web browsers, so that safe connections to the certified servers work efficiently out-of-the-box. The q |
https://en.wikipedia.org/wiki/Super-recursive%20algorithm | In computability theory, super-recursive algorithms are a generalization of ordinary algorithms that are more powerful, that is, compute more than Turing machines. The term was introduced by Mark Burgin, whose book "Super-recursive algorithms" develops their theory and presents several mathematical models. Turing machines and other mathematical models of conventional algorithms allow researchers to find properties of recursive algorithms and their computations. In a similar way, mathematical models of super-recursive algorithms, such as inductive Turing machines, allow researchers to find properties of super-recursive algorithms and their computations.
Burgin, as well as other researchers (including Selim Akl, Eugene Eberbach, Peter Kugel, Jan van Leeuwen, Hava Siegelmann, Peter Wegner, and Jiří Wiedermann) who studied different kinds of super-recursive algorithms and contributed to the theory of super-recursive algorithms, have argued that super-recursive algorithms can be used to disprove the Church-Turing thesis, but this point of view has been criticized within the mathematical community and is not widely accepted.
Definition
Burgin (2005: 13) uses the term recursive algorithms for algorithms that can be implemented on Turing machines, and uses the word algorithm in a more general sense. Then a super-recursive class of algorithms is "a class of algorithms in which it is possible to compute functions not computable by any Turing machine" (Burgin 2005: 107).
Super-recursive algorithms are closely related to hypercomputation
in a way similar to the relationship between ordinary computation and ordinary algorithms. Computation is a process, while an algorithm is a finite constructive description of such a process. Thus a super-recursive algorithm defines a "computational process (including processes of input and output) that cannot be realized by recursive algorithms." (Burgin 2005: 108). A more restricted definition demands that hypercomputation solves a sup |
https://en.wikipedia.org/wiki/Helium%20mass%20spectrometer | A helium mass spectrometer is an instrument commonly used to detect and locate small leaks. It was initially developed in the Manhattan Project during World War II to find extremely small leaks in the gas diffusion process of uranium enrichment plants. It typically uses a vacuum chamber in which a sealed container filled with helium is placed. Helium leaks out of the container, and the rate of the leak is detected by a mass spectrometer.
Detection technique
Helium is used as a tracer because it penetrates small leaks rapidly. Helium also has the properties of being non-toxic, chemically inert and present in the atmosphere only in minute quantities (5 ppm). Typically a helium leak detector will be used to measure leaks in the range of 10 to 10 Pa·m·s.
A flow of 10 Pa·m·s is about 0.006 ml per minute at standard conditions for temperature and pressure (STP).
A flow of 10 Pa·m·s is about 0.003 ml per century at STP.
Types of leaks
Typically there are two types of leaks in the detection of helium as a tracer for leak detection: residual leak and virtual leak. A residual leak is a real leak due to an imperfect seal, a puncture, or some other hole in the system. A virtual leak is the semblance of a leak in a vacuum system caused by outgassing of chemicals trapped or adhered to the interior of a system that is actually sealed. As the gases are released into the chamber, they can create a false positive indication of a residual leak in the system.
Uses
Helium mass spectrometer leak detectors are used in production line industries such as refrigeration and air conditioning, automotive parts, carbonated beverage containers food packages and aerosol packaging, as well as in the manufacture of steam products, gas bottles, fire extinguishers, tire valves, and numerous other products including all vacuum systems.
Test methods
Global helium spray
This method requires the part to be tested to be connected to a helium leak detector. The outer surface of the part to be tes |
https://en.wikipedia.org/wiki/Cray-2 | The Cray-2 is a supercomputer with four vector processors made by Cray Research starting in 1985. At 1.9 GFLOPS peak performance, it was the fastest machine in the world when it was released, replacing the Cray X-MP in that spot. It was, in turn, replaced in that spot by the Cray Y-MP in 1988.
The Cray-2 was the first of Seymour Cray's designs to successfully use multiple CPUs. This had been attempted in the CDC 8600 in the early 1970s, but the emitter-coupled logic (ECL) transistors of the era were too difficult to package into a working machine. The Cray-2 addressed this through the use of ECL integrated circuits, packing them in a novel 3D wiring that greatly increased circuit density.
The dense packaging and resulting heat loads were a major problem for the Cray-2. This was solved in a unique fashion by forcing the electrically inert Fluorinert liquid through the circuitry under pressure and then cooling it outside the processor box. The unique "waterfall" cooler system came to represent high-performance computing in the public eye and was found in many informational films and as a movie prop for some time.
Unlike the original Cray-1, the Cray-2 had difficulties delivering peak performance. Other machines from the company, like the X-MP and Y-MP, outsold the Cray-2 by a wide margin. When Cray began development of the Cray-3, the company chose to develop the Cray C90 series instead. This is the same sequence of events that occurred when the 8600 was being developed, and as in that case, Cray left the company.
Initial design
With the successful launch of his famed Cray-1, Seymour Cray turned to the design of its successor. By 1979 he had become fed up with management interruptions in what was now a large company, and as he had done in the past, decided to resign his management post and move to form a new lab. As with his original move to Chippewa Falls, Wisconsin from Control Data HQ in Minneapolis, Minnesota, Cray management understood his needs and support |
https://en.wikipedia.org/wiki/Boris%20Aronov | Boris Aronov (born March 13, 1963) is a computer scientist, currently a professor at the Tandon School of Engineering, New York University. His main area of research is computational geometry. He is a Sloan Research Fellow.
Aronov earned his B.A. in computer science and mathematics in 1984 from Queens College, City University of New York. He went on to graduate studies at the Courant Institute of Mathematical Sciences of New York University, where he received his M.S. in 1986 and Ph.D. in 1989, under the supervision of Micha Sharir. |
https://en.wikipedia.org/wiki/Linear%20circuit | A linear circuit is an electronic circuit which obeys the superposition principle. This means that the output of the circuit F(x) when a linear combination of signals ax1(t) + bx2(t) is applied to it is equal to the linear combination of the outputs due to the signals x1(t) and x2(t) applied separately:
It is called a linear circuit because the output voltage and current of such a circuit are linear functions of its input voltage and current. This kind of linearity is not the same as that of straight-line graphs.
In the common case of a circuit in which the components' values are constant and don't change with time, an alternate definition of linearity is that when a sinusoidal input voltage or current of frequency f is applied, any steady-state output of the circuit (the current through any component, or the voltage between any two points) is also sinusoidal with frequency f. A linear circuit with constant component values is called linear time-invariant (LTI).
Informally, a linear circuit is one in which the electronic components' values (such as resistance, capacitance, inductance, gain, etc.) do not change with the level of voltage or current in the circuit. Linear circuits are important because they can amplify and process electronic signals without distortion. An example of an electronic device that uses linear circuits is a sound system.
Alternate definition
The superposition principle, the defining equation of linearity, is equivalent to two properties, additivity and homogeneity, which are sometimes used as an alternate definition
Additivity
Homogeneity
That is, a linear circuit is a circuit in which (1) the output when a sum of two signals is applied is equal to the sum of the outputs when the two signals are applied separately, and (2) scaling the input signal by a factor scales the output signal by the same factor.
Linear and nonlinear components
A linear circuit is one that has no nonlinear electronic components in it. Examples of line |
https://en.wikipedia.org/wiki/Fingerprint%20scanner | Fingerprint scanners are security systems of biometrics. They are used in police stations, security industries, smartphones, and other mobile devices.
Fingerprints
People have patterns of friction ridges on their fingers, these patterns are called the fingerprints. Fingerprints are uniquely detailed, durable over an individual's lifetime, and difficult to alter. Due to the unique combinations, fingerprints have become an ideal means of identification.
Types of fingerprint scanners
There are four types of fingerprint scanners: optical scanners, capacitance scanners, ultrasonic scanners, and thermal scanners. The basic function of every type of scanner is to obtain an image of a person's fingerprint and find a match for it in its database. The measure of the fingerprint image quality is in dots per inch (DPI).
Optical scanners take a visual image of the fingerprint using a digital camera.
Capacitive or CMOS scanners use capacitors and thus electric current to form an image of the fingerprint. This type of scanner tends to excel in terms of precision.
Ultrasonic fingerprint scanners use high frequency sound waves to penetrate the epidermal (outer) layer of the skin.
Thermal scanners sense the temperature differences on the contact surface, in between fingerprint ridges and valleys.
All fingerprint scanners are susceptible to be fooled by a technique that involves photographing fingerprints, processing the photographs using special software, and printing fingerprint replicas using a 3D printer.
Construction forms
There are two construction forms: the stagnant and the moving fingerprint scanner.
Stagnant: The finger must be dragged over the small scanning area. This is cheaper and less reliable than the moving form. Imaging can be less than ideal when the finger is not dragged over the scanning area at constant speed.
Moving: The finger lies on the scanning area while the scanner runs underneath. Because the scanner moves at constant speed over the fingerpri |
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