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https://en.wikipedia.org/wiki/Neutrino%20decoupling | In Big Bang cosmology, neutrino decoupling was the epoch at which neutrinos ceased interacting with other types of matter, and thereby ceased influencing the dynamics of the universe at early times. Prior to decoupling, neutrinos were in thermal equilibrium with protons, neutrons and electrons, which was maintained through the weak interaction. Decoupling occurred approximately at the time when the rate of those weak interactions was slower than the rate of expansion of the universe. Alternatively, it was the time when the time scale for weak interactions became greater than the age of the universe at that time. Neutrino decoupling took place approximately one second after the Big Bang, when the temperature of the universe was approximately 10 billion kelvin, or 1 MeV.
As neutrinos rarely interact with matter, these neutrinos still exist today, analogous to the much later cosmic microwave background emitted during recombination, around 377,000 years after the Big Bang. They form the cosmic neutrino background (abbreviated CνB or CNB). The neutrinos from this event have a very low energy, around 10−10 times smaller than is possible with present-day direct detection. Even high energy neutrinos are notoriously difficult to detect, so the CNB may not be directly observed in detail for many years, if at all. However, Big Bang cosmology makes many predictions about the CNB, and there is very strong indirect evidence that the CNB exists.
Derivation of decoupling time
Neutrinos are scattered (interfering with free streaming) by their interactions with electrons and positrons, such as the reaction
.
The approximate rate of these interactions is set by the number density of electrons and positrons, the averaged product of the cross section for interaction and the velocity of the particles. The number density of the relativistic electrons and positrons depends on the cube of the temperature , so that . The product of the cross section and velocity for weak interactions fo |
https://en.wikipedia.org/wiki/Kentik | Kentik is an American network observability, network monitoring and anomaly detection company headquartered in San Francisco, California.
History
Kentik was founded in 2014 as CloudHelix by Co-founders Avi Freedman, Ian Applegate, Ian Pye, and Justin Biegel. The company changed its name to Kentik in 2015.
Technology
Kentik's Network Observability Cloud is a software-as-a-service (SaaS) product that ingests NetFlow and other network data and analyzes it to provide network monitoring and anomaly detection services for the operators of Internet-connected networks. Kentik's underlying data engine is a clustered datastore modeled on Dremel. The engine collects and correlates live operational data from Internet routers and switches to produce network activity and health information.
Analysis
Since November 2020, Kentik has been the organizational home of Doug Madory's Internet routing analysis practice, previously associated with Renesys and Renesys' subsequent acquirers DynDNS and Oracle. While employed by Kentik, Madory discovered the Global Resource Systems IP address hijacking which occurred during the final hours of the Trump administration and was the first to accurately quantify the 2021 Facebook outage, the largest communications outage in history. |
https://en.wikipedia.org/wiki/Attack%20surface | The attack surface of a software environment is the sum of the different points (for "attack vectors") where an unauthorized user (the "attacker") can try to enter data to, extract data, control a device or critical software in an environment. Keeping the attack surface as small as possible is a basic security measure.
Elements of an attack surface
Worldwide digital change has accelerated the size, scope, and composition of an organization's attack surface. The size of an attack surface may fluctuate over time, adding and subtracting assets and digital systems (e.g. websites, hosts, cloud and mobile apps, etc.). Attack surface sizes can change rapidly as well. Digital assets eschew the physical requirements of traditional network devices, servers, data centers, and on-premise networks. This leads to attack surfaces changing rapidly, based on the organization's needs and the availability of digital services to accomplish it.
Attack surface scope also varies from organization to organization. With the rise of digital supply chains, interdependencies, and globalization, an organization's attack surface has a broader scope of concern (viz. vectors for cyberattacks). Lastly, the composition of an organization's attack surface consists of small entities linked together in digital relationships and connections to the rest of the internet and organizational infrastructure, including the scope of third-parties, digital supply chain, and even adversary-threat infrastructure.
An attack surface composition can range widely between various organizations, yet often identify many of the same elements, including:
Autonomous System Numbers (ASNs)
IP Address and IP Blocks
Domains and Sub-Domains (direct and third-parties)
SSL Certificates and Attribution
WHOIS Records, Contacts, and History
Host and Host Pair Services and Relationship
Internet Ports and Services
NetFlow
Web Frameworks (PHP, Apache, Java, etc.)
Web Server Services (email, database, applications)
Pub |
https://en.wikipedia.org/wiki/Bulb | In botany, a bulb is structurally a short stem with fleshy leaves or leaf bases that function as food storage organs during dormancy. (In gardening, plants with other kinds of storage organ are also called "ornamental bulbous plants" or just "bulbs".)
Description
The bulb's leaf bases, also known as scales, generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions. At the center of the bulb is a vegetative growing point or an unexpanded flowering shoot. The base is formed by a reduced stem, and plant growth occurs from this basal plate. Roots emerge from the underside of the base, and new stems and leaves from the upper side. Tunicate bulbs have dry, membranous outer scales that protect the continuous lamina of fleshy scales. Species in the genera Allium, Hippeastrum, Narcissus, and Tulipa all have tunicate bulbs. Non-tunicate bulbs, such as Lilium and Fritillaria species, lack the protective tunic and have looser scales.
Bulbous plant species cycle through vegetative and reproductive growth stages; the bulb grows to flowering size during the vegetative stage and the plant flowers during the reproductive stage. Certain environmental conditions are needed to trigger the transition from one stage to the next, such as the shift from a cold winter to spring. Once the flowering period is over, the plant enters a foliage period of about six weeks during which time the plant absorbs nutrients from the soil and energy from the sun for setting flowers for the next year. Bulbs dug up before the foliage period is completed will not bloom the following year but then should flower normally in subsequent years.
Plants that form bulbs
Plants that form underground storage organs, including bulbs as well as tubers and corms, are called geophytes. Some epiphytic orchids (family Orchidaceae) form above-ground storage organs called pseudobulbs, that superficially resemble bulbs.
Nearly all plants that form true bulbs are monocotyl |
https://en.wikipedia.org/wiki/FEFLOW | FEFLOW (Finite Element subsurface FLOW system) is a computer program for simulating groundwater flow, mass transfer and heat transfer in porous media and fractured media. The program uses finite element analysis to solve the groundwater flow equation of both saturated and unsaturated conditions as well as mass and heat transport, including fluid density effects and chemical kinetics for multi-component reaction systems.
History
The software was firstly introduced by Hans-Jörg G. Diersch in 1979, see and. He developed the software in the Institute of Mechanics of the German Academy of Sciences Berlin up to 1990. In 1990 he was one of the founders of WASY GmbH of Berlin, Germany (the acronym WASY translates from German to Institute for Water Resources Planning and Systems Research), where FEFLOW has been developed further, continuously improved and extended as a commercial simulation package. In 2007 the shares of WASY GmbH were purchased by DHI. The WASY company has been fused and FEFLOW became part of the DHI Group software portfolio. FEFLOW is being further developed at DHI by an international team. Software distribution and services are worldwide.
Technology
The program is offered in both 32-bit and 64-bit versions for Microsoft Windows and Linux operating systems.
FEFLOW's theoretical basis is fully described in the comprehensive FEFLOW book. It covers a wide range of physical and computational issues in the field of porous/fractured-media modeling. The book starts with a more general theory for all relevant flow and transport phenomena on the basis of the continuum mechanics, systematically develops the basic framework for important classes of problems (e.g., multiphase/multispecies non-isothermal flow and transport phenomena, variably saturated porous media, free-surface groundwater flow, aquifer-averaged equations, discrete feature elements), introduces finite element methods for solving the basic multidimensional balance equations, in detail discusses a |
https://en.wikipedia.org/wiki/Declaration%20of%20Helsinki | The Declaration of Helsinki (DoH, ), is a set of ethical principles regarding human experimentation developed originally in 1964 for the medical community by the World Medical Association (WMA). It is widely regarded as the cornerstone document on human research ethics.
It is not a legally binding instrument under the international law, but instead draws its authority from the degree to which it has been codified in, or influenced, national or regional legislation and regulations. Its role was described by a Brazilian forum in 2000 in these words: "Even though the Declaration of Helsinki is the responsibility of the World Medical Association, the document should be considered the property of all humanity."
Principles
The Declaration is morally binding on physicians, and that obligation overrides any national or local laws or regulations, if the Declaration provides for a higher standard of protection of humans than the latter. Investigators still have to abide by local legislation but will be held to the higher standard.
Basic principles
The fundamental principle is respect for the individual (Article 8), his or her right to self-determination and the right to make informed decisions (Articles 20, 21 and 22) regarding participation in research, both initially and during the course of the research. The investigator's duty is solely to the patient (Articles 2, 3 and 10) or volunteer (Articles 16, 18), and while there is always a need for research (Article 6), the participant's welfare must always take precedence over the interests of science and society (Article 5), and ethical considerations must always take precedence over laws and regulations (Article 9).
The recognition of the increased vulnerability of individuals and groups calls for special vigilance (Article 8). It is recognized that when the research participant is incompetent, physically or mentally incapable of giving consent, or is a minor (Articles 23, 24), then allowance should be considered for su |
https://en.wikipedia.org/wiki/Iron%20fertilization | Iron fertilization is the intentional introduction of iron-containing compounds (like iron sulfate) to iron-poor areas of the ocean surface to stimulate phytoplankton production. This is intended to enhance biological productivity and/or accelerate carbon dioxide () sequestration from the atmosphere. Iron is a trace element necessary for photosynthesis in plants. It is highly insoluble in sea water and in a variety of locations is the limiting nutrient for phytoplankton growth. Large algal blooms can be created by supplying iron to iron-deficient ocean waters. These blooms can nourish other organisms.
Ocean iron fertilization is an example of a geoengineering technique. Iron fertilization attempts to encourage phytoplankton growth, which removes carbon from the atmosphere for at least a period of time. This technique is controversial because there is limited understanding of its complete effects on the marine ecosystem, including side effects and possibly large deviations from expected behavior. Such effects potentially include release of nitrogen oxides, and disruption of the ocean's nutrient balance. Controversy remains over the effectiveness of atmospheric sequestration and ecological effects. Since 1990, 13 major large scale experiments have been carried out to evaluate efficiency and possible consequences of iron fertilization in ocean waters. A study in 2017 determined that the method is unproven; sequestering efficiency is low and sometimes no effect was seen and the amount of iron deposits that is needed to make a small cut in the carbon emissions is in the million tons per year.
Approximately 25 per cent of the ocean surface has ample macronutrients, with little plant biomass (as defined by chlorophyll). The production in these high-nutrient low-chlorophyll (HNLC) waters is primarily limited by micronutrients, especially iron. The cost of distributing iron over large ocean areas is large compared with the expected value of carbon credits. Research in the |
https://en.wikipedia.org/wiki/Material%20implication%20%28rule%20of%20inference%29 | In propositional logic, material implication is a valid rule of replacement that allows for a conditional statement to be replaced by a disjunction in which the antecedent is negated. The rule states that P implies Q is logically equivalent to not- or and that either form can replace the other in logical proofs. In other words, if is true, then must also be true, while if is true, then cannot be true either; additionally, when is not true, may be either true or false.
Where "" is a metalogical symbol representing "can be replaced in a proof with," P and Q are any given logical statements, and can be read as "(not P) or Q". To illustrate this, consider the following statements:
: Sam ate an orange for lunch
: Sam ate a fruit for lunch
Then, to say, "Sam ate an orange for lunch" "Sam ate a fruit for lunch" (). Logically, if Sam did not eat a fruit for lunch, then Sam also cannot have eaten an orange for lunch (by contraposition). However, merely saying that Sam did not eat an orange for lunch provides no information on whether or not Sam ate a fruit (of any kind) for lunch.
Partial proof
Suppose we are given that . Then, we have by the law of excluded middle (i.e. either must be true, or must not be true).
Subsequently, since , can be replaced by in the statement, and thus it follows that (i.e. either must be true, or must not be true).
Suppose, conversely, we are given . Then if is true that rules out the first disjunct, so we have . In short, . However if is false, then this entailment fails, because the first disjunct is true which puts no constraint on the second disjunct . Hence, nothing can be said about . In sum, the equivalence in the case of false is only conventional, and hence the formal proof of equivalence is only partial.
This can also be expressed with a truth table:
Example
An example: we are given the conditional fact that if it is a bear, then it can swim. Then, all 4 possibilities in the truth table are compared |
https://en.wikipedia.org/wiki/Backyard%20Ballistics | Backyard Ballistics is a how-to book by William Gurstelle that was published in 2001. It is full of experiments that can be done relatively inexpensively and can be easily executed. It also includes the history and mechanical principles of some of the inventions and projects. From catapults to rockets, this book describes accessible ways to create these at home or in the classroom. In addition to recreational use by individuals, teacher's guides have been developed and science fair projects designed around this book. It has been cited in several educational and scientific journals. |
https://en.wikipedia.org/wiki/GATC%20%28gene%29 | Glutamyl-tRNA(Gln) amidotransferase, subunit C homolog (bacterial) is a protein that in humans is encoded by the GATC gene. The gene is also known as 15E1.2 and encodes part of a Glu-tRNA(Gln) amidotransferase enzyme.
Model organisms
Model organisms have been used in the study of GATC function. A conditional knockout mouse line, called Gatctm1a(KOMP)Wtsi was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists — at the Wellcome Trust Sanger Institute.
Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Twenty eight tests were carried out on mutant mice and two significant abnormalities were observed. No homozygous mutant embryos were recorded during gestation and, in a separate study, no homozygous animals were observed at weaning. This may imply that double deletion of the GATC gene is lethal to zygotes. The remaining tests were carried out on adult heterozygous mutant animals but no further abnormalities were seen. |
https://en.wikipedia.org/wiki/Charles%20Clement%20Coe | Charles Clement Coe (1830-1921) was an English Unitarian minister and writer.
Coe was born in King's Lynn and educated at Manchester College, Oxford. He was President of the Leicester Literary and Philosophical Society (1862-1863) and was Minister of the Unitarian Great Meeting chapel in Bond Street, Leicester. His was minister at Bank Street Unitarian Chapel in Bolton, Lancashire, from 1874 to 1895, when he moved to Bournemouth.
It was while at Bolton that Coe wrote a large volume, Nature Versus Natural Selection: An Essay on Organic Evolution (1895). He defended evolution but rejected natural selection. The biologist J. Arthur Thomson gave the book a positive review, commenting that it is a very interesting critique of natural selection written with much skill.
Publications
Nature Versus Natural Selection: An Essay on Organic Evolution (1895)
Notes
External links
1830 births
1921 deaths
English Unitarian ministers
People from King's Lynn
19th-century English clergy
20th-century English clergy
Alumni of Harris Manchester College, Oxford |
https://en.wikipedia.org/wiki/Simple%20Dietz%20method | The simple Dietz method is a means of measuring historical investment portfolio performance, compensating for external flows into/out of the portfolio during the period. The formula for the simple Dietz return is as follows:
where
is the portfolio rate of return,
is the beginning market value,
is the ending market value, and
is the net external inflow during the period (flows out of the portfolio are negative and flows into the portfolio are positive).
It is based on the assumption that all external flows occur at the half-way point in time within the evaluation period (or are spread evenly across the period, and so the flows occur on average at the middle of the period).
Fees
To measure returns net of fees, allow the value of the portfolio to be reduced by the amount of the fees. To calculate returns gross of fees, compensate for them by treating them as an external flow, and exclude accrued fees from valuations, i.e. do not reduce the portfolio market value by the fee amount accrued.
Discussion
The simple Dietz method is a variation upon the simple rate of return, which assumes that external flows occur either at the beginning or at the end of the period. The simple Dietz method is somewhat more computationally tractable than the internal rate of return (IRR) method.
A refinement of the simple Dietz method is the modified Dietz method, which takes available information on the actual timing of external flows into consideration.
Like the modified Dietz method, the simple Dietz method is based on the assumption of a simple rate of return principle, unlike the internal rate of return method, which applies a compounding principle.
Also like the modified Dietz method, it is a money-weighted returns method (as opposed to a time-weighted returns method). In particular, if the simple Dietz returns on two portfolios over the same period are and , then the simple Dietz return on the combined portfolio containing the two portfolios is the weighted average |
https://en.wikipedia.org/wiki/Tali%27Zorah | Tali'Zorah, or Tali in short, is a character in BioWare's Mass Effect franchise, who serves as a party member (or "squadmate") in all three games in the Mass Effect trilogy. She is of the quarian alien race. Within the series, she is a skilled technician and the daughter of Rael'Zorah, a member of the quarian judicial review Admiralty Board. Ash "Liz" Sroka voices Tali in each of her appearances. Outside of the trilogy, Tali appears in Mass Effect: Homeworlds, a comic series with individual issues on each of several Mass Effect 3 squadmates.
Tali was initially the only quarian in the series. In the sequels, more extreme variations of her design were discarded in favor of revisions on her previous look. The Mass Effect 3 development team considered her removal from the squad, but ultimately chose to include her due to staff interest. The team also debated whether to reveal her masked face.
Tali has been received positively, and is one of the series' most popular characters. Her true appearance was a common online discussion topic amongst fans, though her face, upon its reveal, was criticized for being based on a stock photo, and was later replaced in a remaster. Various merchandise for the character, as with other of the series' squadmates, has been released.
Character overview
Tali is a quarian, one of a nomadic alien race driven from their homeworld, Rannoch, by a race of software-based intelligences which they created, the geth. As a quarian, Tali must wear a full-body environmental suit due to her race's weaker immune systems, which also has the effect of hiding her physical appearance and facial features. Tali is first introduced on her Pilgrimage, a quarian rite where young adults leave to obtain a gift for a captain so as to be allowed to join their crew. Having completed this after the first game, her design in Mass Effect 2 and 3 reflects her new maturity. In both Mass Effect 2 and Mass Effect 3, Tali's default appearance can be changed to various altern |
https://en.wikipedia.org/wiki/Geroch%20group | The Geroch group is an infinite-dimensional symmetry group of axisymmetric, stationary vacuum spacetimes that are solutions of Einstein's equations of general relativity. It is generated by two non-commuting subgroups: the Matzner–Misner group (after Richard Alfred Matzner and Charles W. Misner) of linear combinations (with constant coefficients) of the two Killing vector fields associated with the spacetime's axisymmetry and stationarity, and the Ehlers group.
See also
Robert Geroch
Bibliography
General relativity |
https://en.wikipedia.org/wiki/Rainbow%20plaque | The Rainbow Plaque programme is a UK system installing commemorative plaques to highlight significant people, places and moments in LGBTQIA+ history. Emulating established UK blue plaque programmes run by English Heritage, local authorities and other bodies, the first permanent rainbow plaque (a blue circular plaque with six rainbow colours around the circumference) was unveiled in York in July 2018. Some UK LGBT locations are denoted by pink plaques, an idea that predated rainbow plaques.
History
The rainbow plaque programme was initiated in 2018 by York Civic Trust and the York LGBT Forum to honour lesbian diarist Anne Lister (1791–1840) and her partner Ann Walker, with the first version of a plaque unveiled on 24 July 2018, replaced with amended wording including the word 'lesbian' in February 2019. Temporary cardboard plaques were also placed on key sites during LGBT pride campaigns in York in 2018 and Leeds in 2019.
The permanent plaque initiative then extended nationally through the Wandsworth LGBTQ+ Forum and Studio Voltaire, unveiling permanent plaques for Oscar Wilde at Clapham Junction railway station on 24 July 2019, and for the 1985 film My Beautiful Laundrette on Wilcox Road in South Lambeth on 10 September 2021. A rainbow plaque was also unveiled in Burnley on 30 July 2021 marking the 50th anniversary of a meeting of the Campaign for Homosexual Equality held at Burnley Library.
In 2023, five further rainbow plaques were announced for London, supported by the Mayor of London's Untold Stories Fund and Wandsworth Oasis.
Greenwich Tavern - Then a well-known gay bar, the Gloucester Arms (today the Greenwich Tavern) in Greenwich was the location of a key scene in the 1996 film Beautiful Thing which was set and filmed in Thamesmead and Greenwich in southeast London. The plaque was unveiled at the Greenwich Tavern on 23 July 2023.
Black Lesbian and Gay Centre - Originally established in Haringey in 1985, the centre moved to a converted railway arch in Pec |
https://en.wikipedia.org/wiki/James%20Joseph%20Sylvester | James Joseph Sylvester (3 September 1814 – 15 March 1897) was an English mathematician. He made fundamental contributions to matrix theory, invariant theory, number theory, partition theory, and combinatorics. He played a leadership role in American mathematics in the later half of the 19th century as a professor at the Johns Hopkins University and as founder of the American Journal of Mathematics. At his death, he was a professor at Oxford University.
Biography
James Joseph was born in London on 3 September 1814, the son of Abraham Joseph, a Jewish merchant. James later adopted the surname Sylvester when his older brother did so upon emigration to the United States.
At the age of 14, Sylvester was a student of Augustus De Morgan at the University of London. His family withdrew him from the University after he was accused of stabbing a fellow student with a knife. Subsequently, he attended the Liverpool Royal Institution.
Sylvester began his study of mathematics at St John's College, Cambridge in 1831, where his tutor was John Hymers. Although his studies were interrupted for almost two years due to a prolonged illness, he nevertheless ranked second in Cambridge's famous mathematical examination, the tripos, for which he sat in 1837. However, Sylvester was not issued a degree, because graduates at that time were required to state their acceptance of the Thirty-nine Articles of the Church of England, and Sylvester could not do so because he was Jewish. For the same reason, he was unable to compete for a Fellowship or obtain a Smith's prize. In 1838, Sylvester became professor of natural philosophy at University College London and in 1839 a Fellow of the Royal Society of London. In 1841, he was awarded a BA and an MA by Trinity College Dublin. In the same year he moved to the United States to become a professor of mathematics at the University of Virginia, but left after less than four months. A student who had been reading a newspaper in one of Sylvester's lec |
https://en.wikipedia.org/wiki/Hamiltonian%20mechanics | Hamiltonian mechanics emerged in 1833 as a reformulation of Lagrangian mechanics. Introduced by Sir William Rowan Hamilton, Hamiltonian mechanics replaces (generalized) velocities used in Lagrangian mechanics with (generalized) momenta. Both theories provide interpretations of classical mechanics and describe the same physical phenomena.
Hamiltonian mechanics has a close relationship with geometry (notably, symplectic geometry and Poisson structures) and serves as a link between classical and quantum mechanics.
Overview
Phase space coordinates (p,q) and Hamiltonian H
Let be a mechanical system with the configuration space and the smooth Lagrangian Select a standard coordinate system on The quantities are called momenta. (Also generalized momenta, conjugate momenta, and canonical momenta). For a time instant the Legendre transformation of is defined as the map which is assumed to have a smooth inverse For a system with degrees of freedom, the Lagrangian mechanics defines the energy function
The Legendre transform of turns into a function known as the . The Hamiltonian satisfies
which implies that
where the velocities are found from the (-dimensional) equation which, by assumption, is uniquely solvable for The (-dimensional) pair is called phase space coordinates. (Also canonical coordinates).
From Euler–Lagrange equation to Hamilton's equations
In phase space coordinates the (-dimensional) Euler–Lagrange equation
becomes Hamilton's equations in dimensions
From stationary action principle to Hamilton's equations
Let be the set of smooth paths for which and The action functional is defined via
where and (see above). A path is a stationary point of (and hence is an equation of motion) if and only if the path in phase space coordinates obeys the Hamilton's equations.
Basic physical interpretation
A simple interpretation of Hamiltonian mechanics comes from its application on a one-dimensional system consisting of one nonrelativis |
https://en.wikipedia.org/wiki/Virtual%20DOS%20machine | Virtual DOS machines (VDM) refer to a technology that allows running 16-bit/32-bit DOS and 16-bit Windows programs when there is already another operating system running and controlling the hardware.
Overview
Virtual DOS machines can operate either exclusively through typical software emulation methods (e.g. dynamic recompilation) or can rely on the virtual 8086 mode of the Intel 80386 processor, which allows real mode 8086 software to run in a controlled environment by catching all operations which involve accessing protected hardware and forwarding them to the normal operating system (as exceptions). The operating system can then perform an emulation and resume the execution of the DOS software.
VDMs generally also implement support for running 16- and 32-bit protected mode software (DOS extenders), which has to conform to the DOS Protected Mode Interface (DPMI).
When a DOS program running inside a VDM needs to access a peripheral, Windows will either allow this directly (rarely), or will present the DOS program with a virtual device driver (VDD) which emulates the hardware using operating system functions. A VDM will systematically have emulations for the Intel 8259A interrupt controllers, the 8254 timer chips, the 8237 DMA controller, etc.
Concurrent DOS 8086 emulation mode
In January 1985 Digital Research together with Intel previewed Concurrent DOS 286 1.0, a version of Concurrent DOS capable of running real mode DOS programs in the 80286's protected mode. The method devised on B-1 stepping processor chips, however, in May 1985 stopped working on the C-1 and subsequent processor steppings shortly before Digital Research was about to release the product. Although with the E-1 stepping Intel started to address the issues in August 1985, so that Digital Research's "8086 emulation mode" worked again utilizing the undocumented LOADALL processor instruction, it was too slow to be practical. Microcode changes for the E-2 stepping improved the speed again. This ea |
https://en.wikipedia.org/wiki/Jacob%20Riis | Jacob August Riis ( ; May 3, 1849 – May 26, 1914) was a Danish-American social reformer, "muckraking" journalist, and social documentary photographer. He contributed significantly to the cause of urban reform in America at the turn of the twentieth century. He is known for using his photographic and journalistic talents to help the impoverished in New York City; those impoverished New Yorkers were the subject of most of his prolific writings and photography. He endorsed the implementation of "model tenements" in New York with the help of humanitarian Lawrence Veiller. Additionally, as one of the most famous proponents of the newly practicable casual photography, he is considered one of the fathers of photography due to his very early adoption of flash.
While living in New York, Riis experienced poverty and became a police reporter writing about the quality of life in the slums. He attempted to alleviate the poor living conditions of poor people by exposing these conditions to the middle and upper classes.
Biography
Early life
Born in 1849 in Ribe, Denmark, Jacob Riis was the third of the 15 children (one of whom, an orphaned niece, was fostered) of Niels Edward Riis, a schoolteacher and writer for the local Ribe newspaper, and Carolina Riis (née Bendsine Lundholm), a homemaker. Among the 15, only Jacob, one sister, and the foster sister survived into the twentieth century. Riis was influenced by his father, whose school Riis delighted in disrupting. His father persuaded him to read (and improve his English via) Charles Dickens's magazine All the Year Round and the novels of James Fenimore Cooper.
Jacob had a happy childhood but experienced tragedy at the age of eleven when his brother Theodore, a year younger, drowned. He never forgot his mother's grief.
At age eleven or twelve, he donated all the money he had and gave it to a poor Ribe family living in a squalid house if they cleaned it. The tenants took the money and obliged; when he told his mother, she went |
https://en.wikipedia.org/wiki/Institute%20of%20Optics%20and%20Electronics | The Institute of Optics and Electronics of the Chinese Academy of Sciences () is a Chinese science research institute located in the town of Wenxing, Shuangliu District of Chengdu, in southwest China's Sichuan province. It is the largest institute of Chinese Academy of Sciences (CAS) in southwest China, founded in 1970. It is a diversified organization with operations in photoelectric tracking measurement, beam control, adaptive optics, astronomical target photoelectric observation and recognition, advanced optical manufacturing, aerospace photoelectric equipment, micro nano optics, microelectronics optics, and biomedical optics. It has more than 1,200 staff, including 2 academicians of the Chinese Academy of Engineering (CAE), 1 winner of National Science Fund for Outstanding Young Scholars, 1 recruitment program of global experts, 1 chief scientist of National 973 Program, 8 state-level experts in the field of opto-electronics, 13 academic and technological research leaders in Sichuan, and 350 senior S&T personnel.
History
The Institute of Optics and Electronics, Chinese Academy of Sciences was founded in 1970.
Laboratories
Nine Chinese state key laboratories are now under the Institute of Optics and Electronics, such as State Key Laboratory of Optical Technologies for Micro fabrication, CAS Key labs on Beam Control, Adaptive Optics, and Chengdu Measurement and Testing laboratory for Geometrical Parameter and CAS Photoelectric Precision Mechanics.
Leaders
Directors
Communist Party Secretaries |
https://en.wikipedia.org/wiki/Monkey%27s%20fist | A monkey's fist or monkey paw is a type of knot, so named because it looks somewhat like a small bunched fist or paw. It is tied at the end of a rope to serve as a weight, making it easier to throw, and also as an ornamental knot. This type of weighted rope can be used as a hand-to-hand weapon, called a slungshot by sailors. It was also used in the past as an anchor in rock climbing, by stuffing it into a crack. It is still sometimes used today in sandstone, as in the Elbe Sandstone Mountains in Germany.
Description
The monkey's fist knot is most often used as the weight in a heaving line. The line would have the monkey's fist on one end, an eye splice or bowline on the other, with about 30 feet (~10 metres) of line between. A lightweight feeder line would be tied to the bowline, then the weighted heaving line could be hurled between ship and dock. The other end of the lightweight line would be attached to a heavier-weight line, allowing it to be drawn to the target easily.
The knot is often tied around a small weight, such as a stone, marble, tight fold of paper, grapeshot, or a piece of wood. However, this may be considered unsafe and therefore poor seamanship.
The UK Maritime and Coastguard Agency's (MCA) publication "Code of Safe Working Practices for Merchant Seamen", Section 25.3.2, states that "heaving lines should be constructed with a 'monkey’s fist' at one end. To prevent personal injury, the 'fist' should be made only with rope and should not contain added weighting materials".
They should not be attached by metal or plastic clip to the heaving line. Some port authorities instruct linesmen to cut off monkey's fists that use these fastenings.
Tying
The three coils of cordage in a monkey's fist form in effect a set of Borromean rings in three dimensions. This is most obvious when tied flat. The rings should then be started near center, coiled from outside inwards, in all three set of rings, and the third set finished by letting the end exit through th |
https://en.wikipedia.org/wiki/Elastic%20instability | Elastic instability is a form of instability occurring in elastic systems, such as buckling of beams and plates subject to large compressive loads.
There are a lot of ways to study this kind of instability. One of them is to use the method of incremental deformations based on superposing a small perturbation on an equilibrium solution.
Single degree of freedom-systems
Consider as a simple example a rigid beam of length L, hinged in one end and free in the other, and having an angular spring attached to the hinged end. The beam is loaded in the free end by a force F acting in the compressive axial direction of the beam, see the figure to the right.
Moment equilibrium condition
Assuming a clockwise angular deflection , the clockwise moment exerted by the force becomes . The moment equilibrium equation is given by
where is the spring constant of the angular spring (Nm/radian). Assuming is small enough, implementing the Taylor expansion of the sine function and keeping the two first terms yields
which has three solutions, the trivial , and
which is imaginary (i.e. not physical) for and real otherwise. This implies that for small compressive forces, the only equilibrium state is given by , while if the force exceeds the value there is suddenly another mode of deformation possible.
Energy method
The same result can be obtained by considering energy relations. The energy stored in the angular spring is
and the work done by the force is simply the force multiplied by the vertical displacement of the beam end, which is . Thus,
The energy equilibrium condition now yields as before (besides from the trivial ).
Stability of the solutions
Any solution is stable iff a small change in the deformation angle results in a reaction moment trying to restore the original angle of deformation. The net clockwise moment acting on the beam is
An infinitesimal clockwise change of the deformation angle results in a moment
which can be rewritten as
since due t |
https://en.wikipedia.org/wiki/Animal%20cognition | Animal cognition encompasses the mental capacities of non-human animals including insect cognition. The study of animal conditioning and learning used in this field was developed from comparative psychology. It has also been strongly influenced by research in ethology, behavioral ecology, and evolutionary psychology; the alternative name cognitive ethology is sometimes used. Many behaviors associated with the term animal intelligence are also subsumed within animal cognition.
Researchers have examined animal cognition in mammals (especially primates, cetaceans, elephants, dogs, cats, pigs, horses, cattle, raccoons and rodents), birds (including parrots, fowl, corvids and pigeons), reptiles (lizards, snakes, and turtles), fish and invertebrates (including cephalopods, spiders and insects).
Historical background
Earliest inferences
The mind and behavior of non-human animals has captivated the human imagination for centuries. Many writers, such as Descartes, have speculated about the presence or absence of the animal mind. These speculations led to many observations of animal behavior before modern science and testing were available. This ultimately resulted in the creation of multiple hypotheses about animal intelligence.
One of Aesop's Fables was The Crow and the Pitcher, in which a crow drops pebbles into a vessel of water until he is able to drink. This was a relatively accurate reflection of the capability of corvids to understand water displacement. The Roman naturalist Pliny the Elder was the earliest to attest that said story reflects the behavior of real-life corvids.
Aristotle, in his biology, hypothesized a causal chain where an animal's sense organs transmitted information to an organ capable of making decisions, and then to a motor organ. Despite Aristotle's cardiocentrism (mistaken belief that cognition occurred in the heart), this approached some modern understandings of information processing.
Early inferences were not necessarily precise or ac |
https://en.wikipedia.org/wiki/Lectican | Lecticans, also known as hyalectans, are a family of proteoglycans (a type protein that is attached to chains of negatively charged polysaccharides) that are components of the extracellular matrix. There are four members of the lectican family: aggrecan, brevican, neurocan, and versican. Lecticans interact with hyaluronic acid and tenascin-R to form a ternary complex.
Tissue distribution
Aggrecan is a major component of extracellular matrix in cartilage whereas versican is widely expressed in a number of connective tissues including those in vascular smooth muscle, skin epithelial cells, and the cells of central and peripheral nervous system. The expression of neurocan and brevican is largely restricted to neural tissues.
Structure
All four lecticans contain an N-terminal globular domain (G1 domain) that in turn contains an immunoglobulin V-set domain and a Link domain that binds hyaluronic acid; a long extended central domain (CS) that is modified with covalently attached sulfated glycosaminoglycan chains, and a C-terminal globular domain (G3 domain) containing of one or more EGF repeats, a C-type lectin domain and a CRP-like domain. Aggrecan has in addition a globular domain (G2 domain) that is situated between the G1 and CS domains.
See also
Hyaladherin |
https://en.wikipedia.org/wiki/Multiple%20Registration%20Protocol | Multiple Registration Protocol (MRP), which replaced Generic Attribute Registration Protocol (GARP), is a generic registration framework defined by the IEEE 802.1ak amendment to the IEEE 802.1Q standard. MRP allows bridges, switches or other similar devices to register and de-register attribute values, such as VLAN identifiers and multicast group membership across a large local area network. MRP operates at the data link layer.
History
GARP was defined by the IEEE 802.1 working group to provide a generic framework allowing bridges (or other devices like switches) to register and de-register attribute values such as VLAN identifiers and multicast group membership. GARP defines the architecture, rules of operation, state machines and variables for the registration and de-registration of attribute values. GARP was used by two applications: GARP VLAN Registration Protocol (GVRP) for registering VLAN trunking between multilayer switches, and by the GARP Multicast Registration Protocol (GMRP). The latter two were both mostly enhancements for VLAN-aware switches per definition in IEEE 802.1Q.
Multiple Registration Protocol (MRP) was introduced in order to replace GARP, with the IEEE 802.1ak amendment in 2007. The two GARP applications were also modified in order to use MRP. GMRP was replaced by Multiple MAC Registration Protocol (MMRP) and GVRP was replaced by Multiple VLAN Registration Protocol (MVRP). This change essentially moved the definitions of GARP, GVRP, and GMRP into an 802.1Q based environment, implying they were already VLAN aware. This also allowed for significant streamlining of the underlying protocol without much change to the interface of the applications themselves.
The new protocol and applications fixed a problem with the old GARP-based GVRP-based system,
where a simple registration or a failover could take an extremely long time to converge on a large network, incurring a significant bandwidth degradation.
It is expected GARP will be removed from |
https://en.wikipedia.org/wiki/Non-well-founded%20set%20theory | Non-well-founded set theories are variants of axiomatic set theory that allow sets to be elements of themselves and otherwise violate the rule of well-foundedness. In non-well-founded set theories, the foundation axiom of ZFC is replaced by axioms implying its negation.
The study of non-well-founded sets was initiated by Dmitry Mirimanoff in a series of papers between 1917 and 1920, in which he formulated the distinction between well-founded and non-well-founded sets; he did not regard well-foundedness as an axiom. Although a number of axiomatic systems of non-well-founded sets were proposed afterwards, they did not find much in the way of applications until Peter Aczel’s hyperset theory in 1988.
The theory of non-well-founded sets has been applied in the logical modelling of non-terminating computational processes in computer science (process algebra and final semantics), linguistics and natural language semantics (situation theory), philosophy (work on the Liar Paradox), and in a different setting, non-standard analysis.
Details
In 1917, Dmitry Mirimanoff introduced the concept of well-foundedness of a set:
A set, x0, is well-founded if it has no infinite descending membership sequence
In ZFC, there is no infinite descending ∈-sequence by the axiom of regularity. In fact, the axiom of regularity is often called the foundation axiom since it can be proved within ZFC− (that is, ZFC without the axiom of regularity) that well-foundedness implies regularity. In variants of ZFC without the axiom of regularity, the possibility of non-well-founded sets with set-like ∈-chains arises. For example, a set A such that A ∈ A is non-well-founded.
Although Mirimanoff also introduced a notion of isomorphism between possibly non-well-founded sets, he considered neither an axiom of foundation nor of anti-foundation. In 1926, Paul Finsler introduced the first axiom that allowed non-well-founded sets. After Zermelo adopted Foundation into his own system in 1930 (from previous w |
https://en.wikipedia.org/wiki/Polyanhydride | Polyanhydrides are a class of biodegradable polymers characterized by anhydride bonds that connect repeat units of the polymer backbone chain. Their main application is in the medical device and pharmaceutical industry. In vivo, polyanhydrides degrade into non-toxic diacid monomers that can be metabolized and eliminated from the body. Owing to their safe degradation products, polyanhydrides are considered to be biocompatible.
Applications
The characteristic anhydride bonds in polyanhydrides are water-labile (the polymer chain breaks apart at the anhydride bond). This results in two carboxylic acid groups which are easily metabolized and biocompatible.
Biodegradable polymers, such as polyanhydrides, are capable of releasing physically entrapped or encapsulated drugs by well-defined kinetics and are a growing area of medical research. Polyanhydrides have been investigated as an important material for the short-term release of drugs or bioactive agents. The rapid degradation and limited mechanical properties of polyanhydrides render them ideal as controlled drug delivery devices.
One example, Gliadel, is a device in clinical use for the treatment of brain cancer. This product is made of a polyanhydride wafer containing a chemotherapeutic agent. After removal of a cancerous brain tumor, the wafer is inserted into the brain releasing a chemotherapy agent at a controlled rate proportional to the degradation rate of the polymer. The localized treatment of chemotherapy protects the immune system from high levels of radiation.
Other applications of polyanhydrides include the use of unsaturated polyanhydrides in bone replacement, as well as polyanhydride copolymers as vehicles for vaccine delivery.
Classes
There are three main classes of polyanhydrides: aliphatic, unsaturated, and aromatic. These classes are determined by examining their R groups (the chemistry of the molecule between the anhydride bonds).
Aliphatic polyanhydrides consist of R groups |
https://en.wikipedia.org/wiki/Rhizomucor%20pusillus | Rhizomucor pusillus is a species of Rhizomucor. It can cause disease in humans.
R. pusillus is a grey mycelium fungi most commonly found in compost piles. Yellow-brown spores grow on a stalk to reproduce more fungal cells.
Biology
Rhizomucor pusillus is a thermophilic fungus that lives in hot environments. Its growth optimum is between 50 and 70 degrees Celsius. It is a good producer of amylase. It is homothallic and can cause infections in humans and animals. R. pusillus cells have stolons, rhizoids, and branched sporangiophores. Because of the high temperatures required for this microorganism, it is difficult to study in laboratory environments. The ability to utilize different carbon sources can be used differentiate this fungus from other species: it is unable to assimilate sucrose, glycine, phenylalanine, and B-alanine.
Diversity
There are three species in the genus Rhizomucor. R. pusillus, R. miehei, and R.hizomucor variabilis. R. pusillus is the only species of genus that is thermophilic. R. variabilis and R. miehei are homogenous and homothallic. Colors of the sporangia and size and shape of diameter vary between the three species. The degree of intraspecies variability is high. R. pusillus lives in geothermal places that create and produce their own heat, such as piles of compost and garbage or landfills. Thermophiles reproduce both sexually and asexually. Most common reproduction is asexually, through mitosis. Thermophiles reproduce asexually, when a male spore and a female spore come in contact with each other. Different strains of R. pusillus segregate into two subclusters at very high levels causing different EST and G6D patterns.
Roles in disease
Rhizomucor pusillis can lead to zygomycosis in humans. It causes necrosis of infected tissues and pen neural invasion. It is an incredibly rare disease often found in the lungs of patients with a weakened immune system and can often lead to a fatal outcome. It occurs in patients with hematological malign |
https://en.wikipedia.org/wiki/Hilbert%E2%80%93Bernays%20paradox | The Hilbert–Bernays paradox is a distinctive paradox belonging to the family of the paradoxes of reference (like Berry's paradox). It is named after David Hilbert and Paul Bernays.
History
The paradox appears in Hilbert and Bernays' Grundlagen der Mathematik and is used by them to show that a sufficiently strong consistent theory cannot contain its own reference functor. Although it has gone largely unnoticed in the course of the 20th century, it has recently been rediscovered and appreciated for the distinctive difficulties it presents.
Formulation
Just as the semantic property of truth seems to be governed by the naive schema:
(T) The sentence ′P′ is true if and only if P
(where single quotes refer to the linguistic expression inside the quotes), the semantic property of reference seems to be governed by the naive schema:
(R) If a exists, the referent of the name ′a′ is identical with a
Consider however a name h for (natural) numbers satisfying:
(H) h is identical with ′(the referent of h) +1′
Suppose that, for some number n:
(1) The referent of h is identical with n
Then, surely, the referent of h exists, and so does (the referent of h)+1. By (R), it then follows that:
(2) The referent of ′(the referent of h)+1′ is identical with (the referent of h)+1
and so, by (H) and the principle of indiscernibility of identicals, it is the case that:
(3) The referent of h is identical with (the referent of h)+1
But, again by indiscernibility of identicals, (1) and (3) yield:
(4) The referent of h is identical with n +1
and, by transitivity of identity, (1) together with (4) yields:
(5) n is identical with n+1
But (5) is absurd, since no number is identical with its successor.
Solutions
Since every sufficiently strong theory will have to accept something like (H), absurdity can only be avoided either by rejecting the principle of naive reference (R) or by rejecting classical logic (which validates the reasoning from (R) and (H) to absurdity). On the firs |
https://en.wikipedia.org/wiki/Intermittent%20photic%20stimulation | In medicine, Intermittent Photic Stimulation, or IPS, is a form of visual stimulation used in conjunction with electroencephalography to investigate anomalous brain activity triggered by specific visual stimuli, such as flashing lights or patterns.
IPS and EEGs are often used to diagnose conditions such as photosensitive epilepsy. The field is relatively new and the details of use of IPS have not been widely standardized. IPS is often used in conjunction with other controllable generators of visual stimuli, such as low-level visual stimulation LLVS.
Photic stimulation may also be used to elicit myoclonus, especially cortical reflex myoclonus when present in photo-sensitive forms.
IPS may be used to stimulate the visual system for patients with amblyopia. This system uses a visual stimulus that is usually red in color with a frequency of about 4 Hz to stimulate the neural pathway between the retina and the visual cortex. The objective is to improve the visual acuity of an amblyopic (lazy) eye. |
https://en.wikipedia.org/wiki/Relative%20Atrial%20Index | The Relative Atrial Index (RAI) is a numeric parameter used to assess for cardiac shunt defects. It is calculated from the standard transthoracic Doppler echocardiogram measurements of the right atrial area divided by the left atrial area. RAI = right atrial area / left atrial area. These measurements are made from the apical four chamber view.
Large validation studies in patients with known atrial septal defects showed that the RAI > 1.0 in the majority of cases. This is in contrast to matched and population controls, where the RAI was significantly below 1.0. This simple numeric parameter has found a role in the diagnostic work-up for possible shunt defects on standard tranthorcaic echocardiograms. The RAI rapidly normalizes within 24 hours of percutaneous closure of atrial septal defects. Secondary validation studies have confirmed the data in discrete patient populations. This parameter has been shown to predict long-term survival after acute pulmonary embolism.
The RAI was conceptualized in response to observed clinical inadequacies of standard transthoracic echocardiography in some shunt conditions. The same author had developed several Doppler echocardiographic numeric parameters over the last two decades to assess cardiac diastolic function.
See also
Medical ultrasonography section: Doppler sonography
Echocardiography
American Society of Echocardiography
Christian Doppler |
https://en.wikipedia.org/wiki/The%20Oyster%20Question | The Oyster Question: Scientists, Watermen, and the Maryland Chesapeake Bay since 1880 is a 2009 book by Christine Keiner. It examines the conflict between oystermen and scientists in the Chesapeake Bay from the end of the nineteenth century to the present, which includes the period of the so-called "Oyster Wars" and the precipitous decline of the oyster industry at the end of the twentieth century. The book engages the myth of the "Tragedy of the Commons" by examining the often fraught relationship between local politics and conservation science, arguing that for most of the period Maryland's state political system gave rural oystermen more political clout than politicians and the scientists they appointed and allowing oystermen to effectively manage the oyster bed commons. Only towards the end of the twentieth century did reapportionment bring suburban and urban interests more political power, by which time they had latched on to oystermen as elements of the area's heritage and incorporated them and the oysters into broader conservation efforts. An important theme is the "intersection[] of scientific knowledge with experiential knowledge in the context of use," in that Keiner "treats the knowledge of the Chesapeake Bay’s oystermen alongside that of biologists." "Through her analysis, Keiner effectively reframes how environmental historians have analyzed histories of common resources and provides a working model for integrating historical and ecological information to bridge the histories of science and environmental history."
Awards
The book won the 2010 Forum for the History of Science in America Prize. It shared the 2010 Maryland Historical Trust's Heritage Book Award, and received an Honorable Mention for the Frederick Jackson Turner Award from the Organization of American Historians in 2010. |
https://en.wikipedia.org/wiki/Reeler%20domain | Reeler domain is a protein domain. Extracellular matrix (ECM) proteins play an important role in early cortical development, specifically in the formation of neural connections and in controlling the cytoarchitecture of the central nervous system. The product of the reeler gene in mouse is reelin, a large extracellular protein secreted by pioneer neurons that coordinates cell positioning during neurodevelopment. F-spondin and mindin are a family of matrix-attached adhesion molecules that share structural similarities and overlapping domains of expression. Both F-spondin and mindin promote adhesion and outgrowth of hippocampal embryonic neurons and bind to a putative receptor(s) expressed on both hippocampal and sensory neurons.
This domain of unknown function is found at the N terminus of reelin and F-spondin.
Examples
Human genes that encode proteins containing the reeler domain include:
FRRS1, RELN, SPON1 |
https://en.wikipedia.org/wiki/Preauricular%20deep%20parotid%20lymph%20nodes | The preauricular deep parotid lymph nodes (anterior auricular glands or preauricular glands), from one to three in number, lie immediately in front of the tragus.
Their afferents drain multiple surfaces, most of which are lateral in origin. A specific example would be the lateral portions of the eye's bulbar and palpebral conjunctiva as well as the skin adjacent to the ear within the temporal region. The efferents of these nodes pass to the superior deep cervical glands.
The preauricular nodes glands will present with marked swelling in viral conjunctivitis. |
https://en.wikipedia.org/wiki/List%20of%20plants%20by%20common%20name | This is a list of plants organized by their common names. However, the common names of plants often vary from region to region, which is why most plant encyclopedias refer to plants using their scientific names, in other words using binomials or "Latin" names.
A
African sheepbush – Pentzia incana
Alder – Alnus
Black alder – Alnus glutinosa, Ilex verticillata
Common alder – Alnus glutinosa
False alder – Ilex verticillata
Gray alder – Alnus incana
Speckled alder – Alnus incana
White alder – Alnus incana, Alnus rhombifolia, Ilex verticillata
Almond – Prunus dulcis
Aloe vera – Aloe vera
Amaranth – Amaranthus
Foxtail amaranth – Amaranthus caudatus
Ambrosia
Tall ambrosia – Ambrosia trifida
Amy root – Apocynum cannabinum
Angel trumpet – Brugmansia suaveolens
Apple – Malus domestica
Apricot – Prunus armeniaca
Arfaj – Rhanterium epapposum
Arizona sycamore – Platanus wrighitii
Arrowwood – Cornus florida
Indian arrowwood – Cornus florida
Ash – Fraxinus spp.
Black ash – Acer negundo, Fraxinus nigra
Blue ash – Fraxinus quadrangulata
Cane ash – Fraxinus americana
European ash – Fraxinus excelsior
Green ash – Fraxinus pennsylvanica lanceolata
Maple ash – Acer negundo
Red ash – Fraxinus pennsylvanica lanceolata
River ash – Fraxinus pennsylvanica
Swamp ash – Fraxinus pennsylvanica
White ash – Fraxinus americana
Water ash – Acer negundo, Fraxinus pennsylvanica
Azolla – Azolla
Carolina azolla – Azolla caroliniana
B
Bamboo – bamboosa ardinarifolia
Banana – mainly Musa × paradisica, but also other Musa species and hybrids
Baobab – Adansonia
Bay – Laurus spp. or Umbellularia spp.
Bay laurel – Laurus nobilis (culinary)
California bay – Umbellularia californica
Bean – Fabaceae, specifically Phaseolus spp.
Bearberry – Ilex decidua
Bear corn – Veratrum viride
Beech – Fagus
Bindweed
Blue bindweed – Solanum dulcamara
Bird's nest – Daucus carota
Bird's nest plant – Daucus carota
Bird of paradise – Strelitzia reginae
Birch – Betula spp.
Black birch – Betula lenta, Betula nigra
Bolean bir |
https://en.wikipedia.org/wiki/Test%20engineer | A test engineer is a professional who determines how to create a process that would best test a particular product in manufacturing and related disciplines, in order to assure that the product meets applicable specifications. Test engineers are also responsible for determining the best way a test can be performed in order to achieve adequate test coverage. Often test engineers also serve as a liaison between manufacturing, design engineering, sales engineering and marketing communities as well.
Test engineer expertises
Test engineers can have different expertise, which depends on what test process they are more familiar with (although many test engineers have full familiarity from the PCB level processes like ICT, JTAG, and AXI) to PCBA and system level processes like board functional test (BFT or FT), burn-in test, system level test (ST). Some of the processes used in manufacturing where a test engineer is needed are:
In-circuit test (ICT)
Stand-alone JTAG test
Automated x-ray inspection (AXI) (also known as X-ray test)
Automated optical inspection (AOI) test
Center of Gravity (CG) test
Continuity or flying probe test
Electromagnetic compatibility or EMI test
(Board) functional test (BFT/FT)
Burn-in test
Environmental stress screening (ESS) test
Highly Accelerated Life Test (HALT)
Highly accelerated stress screening (HASS) test
Insulation test
Ongoing reliability test (ORT)
Regression test
System test (ST)
Vibration test
Final quality audit process (FQA) test
Early project involvement from design phase
Ideally, a test engineer's involvement with a product begins with the very early stages of the engineering design process, i.e. the requirements engineering stage and the design engineering stage. Depending on the culture of the firm, these early stages could involve a Product Requirements Document (PRD) and Marketing Requirements Document (MRD)—some of the earliest work done during a new product introduction (NPI).
By working with or as part o |
https://en.wikipedia.org/wiki/Viroplasm | A viroplasm, sometimes called "virus factory" or "virus inclusion", is an inclusion body in a cell where viral replication and assembly occurs. They may be thought of as viral factories in the cell. There are many viroplasms in one infected cell, where they appear dense to electron microscopy. Very little is understood about the mechanism of viroplasm formation.
Definition
A viroplasm is a perinuclear or a cytoplasmic large compartment where viral replication and assembly occurs. The viroplasm formation is caused by the interactions between the virus and the infected cell, where viral products and cell elements are confined.
Groups of viruses that form viroplasms
Viroplasms have been reported in many unrelated groups of Eukaryotic viruses that replicate in cytoplasm, however, viroplasms from plant viruses have not been as studied as viroplasms from animal viruses. Viroplasms have been found in the cauliflower mosaic virus, rotavirus, vaccinia virus and the rice dwarf virus. These appear electron-dense under an electron microscope and are insoluble.
Structure and formation
Viroplasms are localized in the perinuclear area or in the cytoplasm of infected cells and are formed early in the infection cycle. The number and the size of viroplasms depend on the virus, the virus isolate, hosts species, and the stage of the infection. For example, viroplasms of mimivirus have a similar size to the nucleus of its host, the amoeba Acanthamoeba polyphaga.
A virus can induce changes in composition and organization of host cell cytoskeletal and membrane compartments, depending on the step of the viral replication cycle. This process involves a number of complex interactions and signaling events between viral and host cell factors.
Viroplasms are formed early during the infection; in many cases, the cellular rearrangements caused during virus infection lead to the construction of sophisticated inclusions —viroplasms— in the cell where the factory will be assembled. The |
https://en.wikipedia.org/wiki/Frontiers%20in%20Physics | Frontiers in Physics is a peer-reviewed open-access scientific journal covering physics. It was established in 2013 and is published by Frontiers Media. The editor-in-chief is Alex Hansen (Norwegian University of Science and Technology). The scope of the journal covers the entire field of physics, from experimental, to computational and theoretical physics.
Abstracting and indexing
The journal is abstracted and indexed in Current Contents/Physical, Chemical & Earth Sciences, Science Citation Index Expanded, and Scopus. According to the Journal Citation Reports, the journal has a 2020 impact factor of 3.560. |
https://en.wikipedia.org/wiki/Hunt%20Institute%20for%20Botanical%20Documentation | The Hunt Institute for Botanical Documentation (HIBD), dedicated as the Rachel McMasters Miller Hunt Botanical Library in 1961, is a research division of Carnegie Mellon University.
History
HIBD is named for Rachel McMasters Miller Hunt. She donated a collection of botanical books to the University to create HIBD. An annual monetary award is given in her honor by the institute.
HIBD was dedicated October 10, 1961. George H. M. Lawrence was the founding director. In 1970, Gilbert Daniels, became the 2nd director. T. D. Jacobsen succeeded Robert Kiger as director in 2019.
Description
HIBD is an institution of international bibliographical research in the fields of botany, horticulture, and plant science history. It has a research library with over 30,000 works and art holdings. It includes art and bibliography departments.
HIBD is better known internationally than in the U.S. It has a collection of botanical paintings (many of them watercolors), drawings, and prints dating from the Renaissance to contemporary works. Its Library has books from an equally expansive time frame.
HIBD hosts public exhibitions, including the triennial International Exhibition of Botanical Art & Illustration exhibitions since 1964. That exhibition coincides with the American Society of Botanical Artists educational conference in Pittsburgh.
Publications
'Botanico-Periodicum-Huntanium' (first started in 1968, Sept 2004 BPH2 began)
'Bulletin of the Hunt Institute for Botanical Documentation'
'Catalogue of Botanical Books in the Collection of Rachel McMasters Hunt'
'Huntia' is a peer-reviewed scientific journal published by the Hunt Institute for Botanical Documentation. In continuous publication since 1964, this journal is the Institute's scholarly journal of botanical history. The journal is published irregularly in one or more numbers per volume of approximately 200 pages by Hunt Institute. Starting with volume 17, the journal is now only published online and in colour. |
https://en.wikipedia.org/wiki/Implicit%20curve | In mathematics, an implicit curve is a plane curve defined by an implicit equation relating two coordinate variables, commonly x and y. For example, the unit circle is defined by the implicit equation . In general, every implicit curve is defined by an equation of the form
for some function F of two variables. Hence an implicit curve can be considered as the set of zeros of a function of two variables. Implicit means that the equation is not expressed as a solution for either x in terms of y or vice versa.
If is a polynomial in two variables, the corresponding curve is called an algebraic curve, and specific methods are available for studying it.
Plane curves can be represented in Cartesian coordinates (x, y coordinates) by any of three methods, one of which is the implicit equation given above. The graph of a function is usually described by an equation in which the functional form is explicitly stated; this is called an explicit representation. The third essential description of a curve is the parametric one, where the x- and y-coordinates of curve points are represented by
two functions both of whose functional forms are explicitly stated, and which are dependent on a common parameter
Examples of implicit curves include:
a line:
a circle:
the semicubical parabola:
Cassini ovals (see diagram),
(see diagram).
The first four examples are algebraic curves, but the last one is not algebraic. The first three examples possess simple parametric representations, which is not true for the fourth and fifth examples. The fifth example shows the possibly complicated geometric structure of an implicit curve.
The implicit function theorem describes conditions under which an equation can be solved implicitly for x and/or y – that is, under which one can validly write or . This theorem is the key for the computation of essential geometric features of the curve: tangents, normals, and curvature. In practice implicit curves have an essential drawback: the |
https://en.wikipedia.org/wiki/David%20May%20%28computer%20scientist%29 | Michael David May FRS FREng (born 24 February 1951) is a British computer scientist. He is a Professor in the Department of Computer Science at the University of Bristol and founder of XMOS Semiconductor, serving until February 2014 as the chief technology officer.
May was lead architect for the transputer. As of 2017, he holds 56 patents, all in microprocessors and multi-processing.
Life and career
May was born in Holmfirth, Yorkshire, England and attended Queen Elizabeth Grammar School, Wakefield. From 1969 to 1972 he was a student at King's College, Cambridge, University of Cambridge, at first studying Mathematics and then Computer Science in the University of Cambridge Mathematical Laboratory, now the University of Cambridge Computer Laboratory.
He moved to the University of Warwick and started research in robotics. The challenges of implementing sensing and control systems led him to design and implement an early concurrent programming language, EPL, which ran on a cluster of single-board microcomputers connected by serial communication links. This early work brought him into contact with Tony Hoare and Iann Barron: one of the founders of Inmos.
When Inmos was formed in 1978, May joined to work on microcomputer architecture, becoming lead architect of the transputer and designer of the associated programming language Occam. This extended his earlier work and was also influenced by Tony Hoare, who was at the time working on CSP and acting as a consultant to Inmos.
The prototype of the transputer was called the Simple 42 and was completed in 1982. The first production transputers, the T212 and T414, followed in 1985; the T800 floating point transputer in 1987. May initiated the design of one of the first VLSI packet switches, the C104, together with the communications system of the T9000 transputer.
Working closely with Tony Hoare and the Programming Research Group at Oxford University, May introduced formal verification techniques into the design of the |
https://en.wikipedia.org/wiki/Multivariate%20kernel%20density%20estimation | Kernel density estimation is a nonparametric technique for density estimation i.e., estimation of probability density functions, which is one of the fundamental questions in statistics. It can be viewed as a generalisation of histogram density estimation with improved statistical properties. Apart from histograms, other types of density estimators include parametric, spline, wavelet and Fourier series. Kernel density estimators were first introduced in the scientific literature for univariate data in the 1950s and 1960s and subsequently have been widely adopted. It was soon recognised that analogous estimators for multivariate data would be an important addition to multivariate statistics. Based on research carried out in the 1990s and 2000s, multivariate kernel density estimation has reached a level of maturity comparable to its univariate counterparts.
Motivation
We take an illustrative synthetic bivariate data set of 50 points to illustrate the construction of histograms. This requires the choice of an anchor point (the lower left corner of the histogram grid). For the histogram on the left, we choose (−1.5, −1.5): for the one on the right, we shift the anchor point by 0.125 in both directions to (−1.625, −1.625). Both histograms have a binwidth of 0.5, so any differences are due to the change in the anchor point only. The colour-coding indicates the number of data points which fall into a bin: 0=white, 1=pale yellow, 2=bright yellow, 3=orange, 4=red. The left histogram appears to indicate that the upper half has a higher density than the lower half, whereas the reverse is the case for the right-hand histogram, confirming that histograms are highly sensitive to the placement of the anchor point.
One possible solution to this anchor point placement problem is to remove the histogram binning grid completely. In the left figure below, a kernel (represented by the grey lines) is centred at each of the 50 data points above. The result of summing these kernels is gi |
https://en.wikipedia.org/wiki/Archaeothyris | Archaeothyris is an extinct genus of ophiacodontid synapsid that lived during the Late Carboniferous and is known from Nova Scotia. Dated to 306 million years ago, Archaeothyris, along with a more poorly known synapsid called Echinerpeton, are the oldest undisputed synapsids known. The name means ancient window (Greek), and refers to the opening in the skull, the temporal fenestra, which indicates this is an early synapsid. Protoclepsydrops also from Nova Scotia is slightly older but is known by very fragmentary materials.
Description
Archaeothyris was more advanced than the early sauropsids, having strong jaws that could open wider than those of the early reptiles. While its sharp teeth were all of the same size & shape, it did possess a pair of enlarged canines, suggesting that it was a carnivore.
Archaeothyris' legs were articulated laterally at its pelvis and shoulders, which gave it a sprawling stance. The first toe is smaller than the second.
Classification
Archaeothyris belonged to the family Ophiacodontidae, a group of early pelycosaurs that evolved early in the Late Carboniferous. It was one of the earliest and most basal synapsids (the group which includes mammals).
Below is a cladogram modified from the analysis of Benson (2012):
Discovery and paleoecology
Fossils of Archaeothyris were first described in 1972 from the Joggins fossil cliffs, the same locality in which the early reptiles Hylonomus and Petrolacosaurus (both of which resemble Archaeothyris) were found.
Archaeothyris lived in what is now Nova Scotia, about 306 million years ago in the Carboniferous Period (Pennsylvanian).
Nova Scotia at this time was a swamp, similar to today's Everglades in Florida. The "trees" (actually giant club mosses) were very tall, some, such as Lepidodendron, up to tall. Archaeothyris and the other early amniotes lived in the moist vegetation on the forest ground, together with the more terrestrially adapted labyrinthodont amphibians.
See also
List of pel |
https://en.wikipedia.org/wiki/Gene%20signature | A gene signature or gene expression signature is a single or combined group of genes in a cell with a uniquely characteristic pattern of gene expression that occurs as a result of an altered or unaltered biological process or pathogenic medical condition. This is not to be confused with the concept of gene expression profiling. Activating pathways in a regular physiological process or a physiological response to a stimulus results in a cascade of signal transduction and interactions that elicit altered levels of gene expression, which is classified as the gene signature of that physiological process or response. The clinical applications of gene signatures breakdown into prognostic, diagnostic and predictive signatures. The phenotypes that may theoretically be defined by a gene expression signature range from those that predict the survival or prognosis of an individual with a disease, those that are used to differentiate between different subtypes of a disease, to those that predict activation of a particular pathway. Ideally, gene signatures can be used to select a group of patients for whom a particular treatment will be effective.
Timeline of gene signature detection
In 1995, 2 studies conducted identified unique approaches to analyzing global gene expression of a genome which collectively promoted the value of identifying and analyzing gene signatures for physiological relevance. The first study reports a technique that improves expressed sequence tag (EST) analysis, known as Serial Analysis of Gene Expression (SAGE) that hinged on sequencing and quantifying mRNA samples which acquired levels of gene expression that eventually revealed characteristic gene expression patterns.
The second study identified a technique that is now widely known as the microarray which quantifies complementary DNA (cDNA) hybridization on a glass slide to analyze the expression of many genes in parallel. These studies drew greater attention to the wealth of information that analysi |
https://en.wikipedia.org/wiki/Caraval | The caraval (also called a cara-serval) is the hybrid cross between a male caracal and a female serval. They have a spotted pattern similar to the serval, but on a darker background.
A servical is the cross between a male serval and a female caracal. A litter of servicals occurred by accident when the two animals were kept in the same enclosure at Los Angeles Zoo. The hybrids were given to an animal shelter. The only photos show them as tawny kittens.
Several serval - caracal offspring have been born in recent years through a breeding program in order to create F1 hybrids. So far; no F1 hybrids of this cross breed are in existence. |
https://en.wikipedia.org/wiki/Catherine-de-Barnes%20Isolation%20Hospital | Catherine-de-Barnes Isolation Hospital was a specialist isolation hospital for infection control in Catherine-de-Barnes, a village within the Metropolitan Borough of Solihull in the English county of West Midlands.
Foundation
In 1907, a "fever hospital" was established as a joint operation of the Solihull and Meriden Councils for isolating patients with infectious diseases such as diphtheria, typhoid fever and smallpox. A purpose-built isolation hospital was built by Solihull and Meriden Rural District Councils in Henwood Lane, Catherine-de-Barnes, and opened by 1910. It was constructed with a main block housing individual one-bed wards and several separate bungalow-style buildings, enough to house ten staff and 16 patients.
Maternity hospital
In the 1950s, when infectious diseases became less prevalent, Catherine-de-Barnes became a convalescent maternity hospital, with the first child apparently being born there on 25 March 1953.
National isolation hospital
Following the building of the maternity block at Solihull Hospital, Catherine-de-Barnes reverted to an isolation hospital. It was designated the United Kingdom's national isolation hospital in 1966 and was kept on permanent standby for patients with highly dangerous diseases. From the late 1960s to the late 1970s, the hospital was ready to accept patients at one hour's notice but had a resident staff of only two people, Leslie and Dorothy Harris. Anyone who wished to enter the 20 acre hospital grounds had to wear protective clothing and be inoculated.
In 1978, Janet Parker, the last known victim of smallpox in the world, was treated and died at Catherine-de-Barnes Isolation Hospital following an outbreak that originated at the University of Birmingham Medical School. The ward in which she died was still sealed off five years after her death, all the furniture and equipment inside left untouched. Janet Parker's father, 71-year-old Frederick Witcomb, had died at Catherine-de-Barnes Hospital a week before his d |
https://en.wikipedia.org/wiki/Fuse%20Mediation%20Router | Fuse Mediation Router is an open source tool for integrating services using Enterprise Integration Patterns based on Apache Camel for use in enterprise IT organizations. It is certified, productized and fully supported by the people who wrote the code. Fuse Mediation Router uses a standard method of notation to go from diagram to implementation without coding.
Fuse Mediation Router is a rule-based routing and process mediation engine that combines the ease of basic POJO development with the clarity of the standard Enterprise Integration Patterns. It can be deployed inside any container or be used stand-alone, and works directly with any kind of transport or messaging model to rapidly integrate existing services and applications.
Fuse Mediation Router is now a part of Red Hat JBoss Fuse.
Tooling
FuseSource offers graphical, Eclipse-based tooling for Apache Camel for download.
See also
Message-oriented middleware
Enterprise messaging system
Enterprise Integration Patterns
Service-oriented architecture
Event-driven SOA
External links
JBoss Fuse (Enterprise ServiceMix) web site
CamelOne Conference
Apache ServiceMix getting started resources
Apache ServiceMix web site
JBoss Fuse (Enterprise ServiceMix) documentation
JBoss Fuse (Enterprise ServiceMix) forums
JBoss Fuse (Enterprise ServiceMix) support
JBoss community web site
Free software distributions
Web services
Web applications |
https://en.wikipedia.org/wiki/Infrabarrelled%20space | In functional analysis, a discipline within mathematics, a locally convex topological vector space (TVS) is said to be infrabarrelled (also spelled infrabarreled) if every bounded barrel is a neighborhood of the origin.
Characterizations
If is a Hausdorff locally convex space then the canonical injection from into its bidual is a topological embedding if and only if is infrabarrelled.
Properties
Every quasi-complete infrabarrelled space is barrelled.
Examples
Every barrelled space is infrabarrelled.
A closed vector subspace of an infrabarrelled space is, however, not necessarily infrabarrelled.
Every product and locally convex direct sum of any family of infrabarrelled spaces is infrabarrelled.
Every separated quotient of an infrabarrelled space is infrabarrelled.
See also |
https://en.wikipedia.org/wiki/Mohr%27s%20circle | Mohr's circle is a two-dimensional graphical representation of the transformation law for the Cauchy stress tensor.
Mohr's circle is often used in calculations relating to mechanical engineering for materials' strength, geotechnical engineering for strength of soils, and structural engineering for strength of built structures. It is also used for calculating stresses in many planes by reducing them to vertical and horizontal components. These are called principal planes in which principal stresses are calculated; Mohr's circle can also be used to find the principal planes and the principal stresses in a graphical representation, and is one of the easiest ways to do so.
After performing a stress analysis on a material body assumed as a continuum, the components of the Cauchy stress tensor at a particular material point are known with respect to a coordinate system. The Mohr circle is then used to determine graphically the stress components acting on a rotated coordinate system, i.e., acting on a differently oriented plane passing through that point.
The abscissa and ordinate (,) of each point on the circle are the magnitudes of the normal stress and shear stress components, respectively, acting on the rotated coordinate system. In other words, the circle is the locus of points that represent the state of stress on individual planes at all their orientations, where the axes represent the principal axes of the stress element.
19th-century German engineer Karl Culmann was the first to conceive a graphical representation for stresses while considering longitudinal and vertical stresses in horizontal beams during bending. His work inspired fellow German engineer Christian Otto Mohr (the circle's namesake), who extended it to both two- and three-dimensional stresses and developed a failure criterion based on the stress circle.
Alternative graphical methods for the representation of the stress state at a point include the Lamé's stress ellipsoid and Cauchy's stress q |
https://en.wikipedia.org/wiki/Booru | {{safesubst:#invoke:RfD||Danbooru|month = October
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https://en.wikipedia.org/wiki/Dexter%20Kozen | Dexter Campbell Kozen (born December 20, 1951) is an American theoretical computer scientist. He is Joseph Newton Pew, Jr. Professor in Engineering at Cornell University. He received his B.A. from Dartmouth College in 1974 and his PhD in computer science in 1977 from Cornell University, where he was advised by Juris Hartmanis. He advised numerous Ph.D. students.
He is a Fellow of the Association for Computing Machinery, a Guggenheim Fellow, and has received an Outstanding Innovation Award from IBM Corporation. He has also been named Faculty of the Year by the Association of Computer Science Undergraduates at Cornell.
Dexter Kozen was one of the first professors to receive the honor of a professorship at The Radboud Excellence Initiative at Radboud University Nijmegen in the Netherlands.
He is known for his work at the intersection of logic and complexity. He is one of the fathers of dynamic logic and developed the version of the modal μ-calculus most used today. Moreover, he has written several textbooks on the theory of computation, automata theory, dynamic logic, and algorithms.
Kozen was a guitarist, singer, and songwriter in the band "Harmful if Swallowed". He also holds the position of faculty advisor for Cornell's rugby football club and plays for the Cortland Homer Thundering Herd rugby team.
Awards and honors
John G. Kemeny Prize in Computing, Dartmouth College)] (1974)
Outstanding Innovation Award, IBM Corporation) (1974)
Fellow, John Simon Guggenheim Foundation (1991)
Prize Nagrode, Polish Ministry of Education, for paper (1993)
Stephen and Margery Russell Distinguished Teaching Award, College of Arts and Sciences, Cornell (2001)
Prize Nagrode, Polish Ministry of Education, for paper (1993)
ACM Fellow, For contributions to theoretical computer science (2003)
Fellow, AAAS (2008)
2001 LICS Test-of-Time Award for the paper (2011)
Fellow, EATCS (2016)
McDowell Award, for groundbreaking contributions to topics ranging from computational comple |
https://en.wikipedia.org/wiki/Symbiogenesis | Symbiogenesis (endosymbiotic theory, or serial endosymbiotic theory) is the leading evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms. The theory holds that mitochondria, plastids such as chloroplasts, and possibly other organelles of eukaryotic cells are descended from formerly free-living prokaryotes (more closely related to the Bacteria than to the Archaea) taken one inside the other in endosymbiosis. Mitochondria appear to be phylogenetically related to Rickettsiales bacteria, while chloroplasts are thought to be related to cyanobacteria.
The idea that chloroplasts were originally independent organisms that merged into a symbiotic relationship with other one-celled organisms dates back to the 19th century, when it was espoused by researchers such as Andreas Schimper. The endosymbiotic theory was articulated in 1905 and 1910 by the Russian botanist Konstantin Mereschkowski, and advanced and substantiated with microbiological evidence by Lynn Margulis in 1967.
Among the many lines of evidence supporting symbiogenesis are that new mitochondria and plastids are formed only by splitting in two, and that cells cannot create new ones otherwise; that the transport proteins called porins are found in the outer membranes of mitochondria, chloroplasts, and bacterial cell membranes; that cardiolipin is found only in the inner mitochondrial membrane and bacterial cell membranes; and that some mitochondria and plastids contain single circular DNA molecules similar to the circular chromosomes of bacteria.
History
The Russian botanist Konstantin Mereschkowski first outlined the theory of symbiogenesis (from Greek: σύν syn "together", βίος bios "life", and γένεσις genesis "origin, birth") in his 1905 work, The nature and origins of chromatophores in the plant kingdom, and then elaborated it in his 1910 The Theory of Two Plasms as the Basis of Symbiogenesis, a New Study of the Origins of Organisms. Mereschkowski knew of the work of botanist A |
https://en.wikipedia.org/wiki/Iain%20Buchan | Iain Edward Buchan is a public health physician, data scientist and academic. He holds the W.H. Duncan Chair of Public Health Systems and is Associate Pro Vice Chancellor for Innovation at the University of Liverpool.
Buchan's research focuses on health data science and informatics to enable better prevention, early intervention, and value of care for patients and populations. He has written 337 articles and his work has been cited of 26000 times according to Google Scholar. He is most known for leading the world's first evaluation of mass rapid antigen testing, and the first realistic risk-mitigated reopening of mass events during the UK's response to the COVID-19 pandemic. He also developed the Civic Data Cooperative, which resulted in the Combined Intelligence for Population Health Action (CIPHA) system during the pandemic. He is the recipient of HTN Health Tech Award, Alwyn-Smith Medal, and Florence Nightingale Award.
Buchan is a Fellow of the Faculty of Public Health, the American College of Medical Informatics, British Computer Society and the Faculty of Clinical Informatics. He has also been an advisor to UK, European and international health policy groups, AstraZeneca) and research organizations including UKRI, Wellcome Trust and the UK National Institute for Health and Care Research (NIHR), for which he is a Senior Investigator.
Education and early career
In the 1980s, Buchan pursued medical training alongside studies in pharmacology and statistical software development. As an undergraduate, he published the first version of a statistical package called "StatsDirect." During the 1990s, as a junior doctor, he researched care pathways, health system dynamics, and care inequities. Later, he trained as a public health consultant while conducting research in medical informatics and pursuing doctoral studies in computational statistics.
Career
Buchan began his academic career in 1992 as an Honorary Clinical Lecturer at the University of Liverpool. He then se |
https://en.wikipedia.org/wiki/Abu%20Abed | Abu Abed is a fictional character that forms the centerpiece of many jokes in Lebanon, though he is known throughout the Arab world. The Washington Post describes him as an "Archie Bunker-like figure who is a fumbling caricature of all the failings of the Lebanese." His full name is sometimes given as Abu Abed El Beyrouty and he is also called Abul Abed or Abu El-Abed.
In illustrations, Abu Abed's most notable features are a large mustache and the red fez he wears on his head. Abu Abed's best friend is Abu Steif, with whom he spends much of the day in the Kahwat El Ejeez قهوة القزاز, an actual and well-known coffee shop in central Beirut. He is sometimes claimed to be a Sunni Beiruti. One example of the literally hundreds of jokes with Abu Abed is:
During the 2006 Israel-Lebanon conflict, the most widely told joke among Lebanese was again about Abu Abed. The jokes goes: Abu Abed is sitting in the cafe when he calls Ehud Olmert, Prime Minister of Israel, to tell him not to come north of the border or he and four of his friends will give Israel trouble. Olmert laughs and tells Abu Abed that one Israeli battalion can easily overrun his neighborhood. This verbal contest escalates until Abu Abed says that he has collected thousands of fighters armed with shoulder-fired rockets and Olmert states that Israel has two million soldiers. "'Two million?' asks Abul Abed. 'In that case I am going to have to surrender. We simply do not have enough room to keep 2 million hostages.'"
Notes and references
External links
Clean Abu El Abed Jokes, collected by Abdallah Hayar
Official Abou El Abed web site
Humor and wit characters
Lebanese culture
Fictional Lebanese people
National personifications |
https://en.wikipedia.org/wiki/Kappaphycus%20alvarezii | Kappaphycus alvarezii, the elkhorn sea moss, is a species of red algae. The elkhorn sea moss varies in size, weight, and age. It is a dark greenish-brown hue and can sometimes be deep purple. The moss is cylindrical in shape throughout the seaweed. Its diameter averages 1.526 mm when dried. Near the base of the seaweed, its average length is from 1 mm to 17 mm and 1 mm to 2 mm in diameter. Firm algae are around 2 m tall, with axes and branches around 1–2 cm in diameter. It used to be believed they reproduced through vegetative fermentation, but recent studies show that they reproduce sexually. They reproduce through vegetative propagation and reproduce sexually. Cross sections of the Elkhorn sea moss have a medulla composed of small thick-walled cells interspaced among large parenchyma cells. This moss is used for various types of foods that humans consume and can also be used to make a jelly-like dessert. This moss is a very good source of minerals and of high commercial interest. It is one of the most important commercial sources of carrageenans, a family of gel-forming, viscosifying polysaccharides. Farming methods affect the character of the carrageenan that can be extracted from the seaweed. It is very fast-growing, known to double its biomass in 15 days.
Habitat and ecology
The Elkhorn sea moss is located in the Pacific, French, and Indian Oceans, as well as the Caribbean sea, South China's sea. It is located on the islands of Hawaii and Guam. Lastly, it is located in Fanning, Moana, Tonga, and Fiji.
Role within native habitat
The role this sea moss plays in its native habitat is to feed the fish in the surrounding area. It also produces and releases certain minerals which benefit the habitat in which it inhabits. It is found on reef flats and the edges of the reef varying in depth. The moss can be anywhere from 1–17 meters deep. It can also loosely attach itself to the coral. They can form large unattached fragments that can form a mat like structure. Th |
https://en.wikipedia.org/wiki/Dark%20Ages%20Radio%20Explorer | Dark Ages Radio Explorer (DARE) is a NASA mission concept, intended to identify redshifted line emission from the earliest neutral hydrogen atoms forming after Cosmic Dawn. The emissions from neutral hydrogen atoms (with a wavelength of 21cm, frequency of 1420MHz at rest) provide unique opportunities to probe the formation of the first stars in the Universe and the period immediately following the Dark Ages of the universe. The planned orbiter would explore the universe as it was from around 80 million years to 420 million years after the Big Bang. The dataset gathered by the mission would provide insight into the formation of the first stars, how the first black holes grew so rapidly, and the reionization of the universe. Computer models of galaxy formation would also be tested. This mission could also add to research on dark matter decay and provide insight for developing lunar surface telescopes that help refind exoplanet exploration of nearby stars.
Background
The period between the formation of stars and galaxies and recombination is known as the "dark ages". During this time, the majority of matter in the universe is neutral hydrogen. This hydrogen has yet to be observed, but experiments are underway to detect the hydrogen line produced during this era. The hydrogen line is produced when an electron in a neutral hydrogen atom is excited to a state where the electron and proton have aligned spins or de-excited as the electron and proton spins transition from being aligned to anti-aligned. The energy difference between these two hyperfine states is electron volts, corresponding to a wavelength of 21 centimeters. At times when neutral hydrogen is in thermodynamic equilibrium with the photons in the cosmic microwave background (CMB), the neutral hydrogen and CMB are said to be "coupled", and the hydrogen line is not observable. The hydrogen line can only be observed when the two temperatures differ.
Theoretical motivation
The Big Bang produced a hot, dense, nea |
https://en.wikipedia.org/wiki/Helmut%20Schreyer | Helmut Theodor Schreyer (4 July 1912 – 12 December 1984) was a German inventor. He is mostly known for his work on the Z3, one of the first personal computers (PC).
Early life
Helmut Schreyer was the son of the minister Paul Schreyer and Martha. When his father started to work in a parish in Mosbach, the young Schreyer went to a school there. He earned his Abitur in 1933.
Career
Schreyer started to study electronic and telecommunications engineering at the Technical University of Berlin in 1934. He got to know Konrad Zuse at the company AV Motiv in 1935. In 1938 Schreyer earned his diploma and then worked as a graduate assistant for Prof Wilhelm Stäblein. Another assistant of Stäblein was Herbert Raabe, who had worked at AEG's research division until 1936.
World War II
In 1939, when World War II started, Schreyer applied for exemption from the drafting for military service, on the basis that his work was important for the war efforts of Nazi Germany. Schreyer submitted to the German government a plan to build a large electronic computer. This plan was rejected by the Nazi German military, because the war was expected to only last a couple of years and building the electronic computer Schreyer envisaged, would have taken much longer. Among others, Schreyer worked on detection technology for unexploded ordnance. He then worked on the accelerometer for the V-2-rocket. Schreyer's prototype of this accelerometer was destroyed, when he fled to Vienna on a train, during the last days of World War II. Schreyer also worked on technology to convert the radar signal into an audio signal which the pilot of a fighter aircraft might recognize.
Konrad Zuse invented and built the so called Z-series of personal computers between 1936 and 1945. Zuse was a schoolmate and co-worker of Schreyer, who advised Zuse on relays. Subsequently, Zuse built the Z3 computer, integrating relays as arithmetic logic unit. The Z3 computer was completed in 1941 and used 2,600 relays, with the di |
https://en.wikipedia.org/wiki/Desulfovirgula | Desulfovirgula is a genus of sulfate reducing, anaerobic, endospore-forming, Gram-positive, thermophilic, motile, rod-shaped bacteria, isolated from an underground mining site in an area of Japan characterized by high geothermal activity.
Up to now (December 2021) Desulfovirgula thermocuniculi is the sole known species in the genus.
Electron acceptors that this organism can utilize include sulfate, sulfite, thiosulfate and elemental sulfur, while H2 (in the presence of CO2) and carboxylic acids can be utilized as electron donors.
See also
List of bacterial orders
List of bacteria genera |
https://en.wikipedia.org/wiki/Inositol-3-phosphate%20synthase | In enzymology, an inositol-3-phosphate synthase () is an enzyme that catalyzes the chemical reaction
D-glucose 6-phosphate 1D-myo-inositol 3-phosphate
Hence, this enzyme has one substrate, D-glucose 6-phosphate, and one product, 1D-myo-inositol 3-phosphate.
This enzyme belongs to the family of isomerases, specifically the class of intramolecular lyases. The systematic name of this enzyme class is 1D-myo-inositol-3-phosphate lyase (isomerizing). Other names in common use include myo-inositol-1-phosphate synthase, D-glucose 6-phosphate cycloaldolase, inositol 1-phosphate synthatase, glucose 6-phosphate cyclase, inositol 1-phosphate synthetase, glucose-6-phosphate inositol monophosphate cycloaldolase, glucocycloaldolase, and 1L-myo-inositol-1-phosphate lyase (isomerizing).
This enzyme participates in streptomycin biosynthesis and inositol phosphate metabolism. It employs one cofactor, NAD+. The reaction this enzyme catalyses represents the first committed step in the production of all inositol-containing compounds, including phospholipids, either directly or by salvage. The enzyme exists in a cytoplasmic form in a wide range of plants, animals, and fungi. It has also been detected in several bacteria and a chloroplast form is observed in alga and higher plants. Inositol phosphates play an important role in signal transduction.
In Saccharomyces cerevisiae (Baker's yeast), the transcriptional regulation of the INO1 gene encoding inositol-3-phosphate synthase has been studied in detail and its expression is sensitive to the availability of phospholipid precursors as well as growth phase. The regulation of the structural gene encoding 1L-myo-inositol-1-phosphate synthase has also been analyzed at the transcriptional level in the aquatic angiosperm, Spirodela polyrrhiza (Giant duckweed) and the halophyte, Mesembryanthemum crystallinum (Common ice plant).
In prokaryotes, myo-D-inositol phosphate synthase was discovered by Bachhawat and Mande in 1999 (reported in J |
https://en.wikipedia.org/wiki/Phalaenopsis%20%C3%97%20gersenii | Phalaenopsis × gersenii is a species of orchid native to Borneo and Sumatra. It is a natural hybrid of Phalaenopsis violacea and Phalaenopsis sumatrana. It is named after Gerrit Jan Gersen (1826-1877). He was a Dutch official, who was deployed to the Dutch East Indies, where he also was active as a plant collector of the Malesian region.
Taxonomy
Phalaenopsis × singuliflora has been viewed as a synonym of Phalaenopsis × gersenii. The other natural hybrid however involves Phalaenopsis bellina instead of Phalaenopsis violacea. |
https://en.wikipedia.org/wiki/International%20Plant%20Nutrition%20Colloquium | The International Plant Nutrition Colloquium (IPNC) is an international conference held every four years for the promotion of research within the field of plant nutrition. Prior to 1981, it was known as the International Colloquium on Plant Analysis and Fertiliser Problems. The IPNC is organised by the International Plant Nutrition Council, which "seeks to advance science-based non-commercial research and education in plant nutrition in order to highlight the importance of this scientific field for crop production, food security, human health and sustainable environmental protection". It is considered that the IPNC is the most important international meeting on plant nutrition globally, with more than 800 delegates attending each meeting. The IPNC covers research in the fields of plant mineral nutrition, plant molecular biology, plant genetics, agronomy, horticulture, ecology, environmental sciences, and fertilizer use and production.
In honour of Professor Horst Marschner, who was a passionate supporter of students and young researchers, the IPNC has established the Marschner Young Scientist Award for outstanding early-career researchers and PhD students with a potential to become future research leaders.
The current President of the International Plant Nutrition Council is Professor Ciro A. Rosolem from the São Paulo State University. The next IPNC is to be held in Iguazu Falls, Brazil, from 22-27 August 2022.
Past and future locations for the IPNC: |
https://en.wikipedia.org/wiki/Back-and-forth%20method | In mathematical logic, especially set theory and model theory, the back-and-forth method is a method for showing isomorphism between countably infinite structures satisfying specified conditions. In particular it can be used to prove that
any two countably infinite densely ordered sets (i.e., linearly ordered in such a way that between any two members there is another) without endpoints are isomorphic. An isomorphism between linear orders is simply a strictly increasing bijection. This result implies, for example, that there exists a strictly increasing bijection between the set of all rational numbers and the set of all real algebraic numbers.
any two countably infinite atomless Boolean algebras are isomorphic to each other.
any two equivalent countable atomic models of a theory are isomorphic.
the Erdős–Rényi model of random graphs, when applied to countably infinite graphs, almost surely produces a unique graph, the Rado graph.
any two many-complete recursively enumerable sets are recursively isomorphic.
Application to densely ordered sets
As an example, the back-and-forth method can be used to prove Cantor's isomorphism theorem, although this was not Georg Cantor's original proof. This theorem states that two unbounded countable dense linear orders are isomorphic.
Suppose that
(A, ≤A) and (B, ≤B) are linearly ordered sets;
They are both unbounded, in other words neither A nor B has either a maximum or a minimum;
They are densely ordered, i.e. between any two members there is another;
They are countably infinite.
Fix enumerations (without repetition) of the underlying sets:
A = { a1, a2, a3, ... },
B = { b1, b2, b3, ... }.
Now we construct a one-to-one correspondence between A and B that is strictly increasing. Initially no member of A is paired with any member of B.
(1) Let i be the smallest index such that ai is not yet paired with any member of B. Let j be some index such that bj is not yet paired with any member of A and ai can be paired wi |
https://en.wikipedia.org/wiki/Nikolay%20Bogolyubov | Nikolay Nikolayevich Bogolyubov (; 21 August 1909 – 13 February 1992), also transliterated as Bogoliubov and Bogolubov, was a Soviet and Russian mathematician and theoretical physicist known for a significant contribution to quantum field theory, classical and quantum statistical mechanics, and the theory of dynamical systems; he was the recipient of the 1992 Dirac Medal.
Biography
Early life (1909–1921)
Nikolay Bogolyubov was born on 21 August 1909 in Nizhny Novgorod, Russian Empire to Russian Orthodox Church priest and seminary teacher of theology, psychology and philosophy Nikolay Mikhaylovich Bogolyubov, and Olga Nikolayevna Bogolyubova, a teacher of music. The Bogolyubovs relocated to the village of Velikaya Krucha in the Poltava Governorate (now in Poltava Oblast, Ukraine) in 1919, where the young Nikolay Bogolyubov began to study physics and mathematics. The family soon moved to Kyiv in 1921, where they continued to live in poverty as the elder Nikolay Bogolyubov only found a position as a priest in 1923.
He attended research seminars in Kyiv University and soon started to work under the supervision of the well-known contemporary mathematician Nikolay Krylov. In 1924, at the age of 15, Nikolay Bogolyubov wrote his first published scientific paper On the behavior of solutions of linear differential equations at infinity. In 1925 he entered Ph.D. program at the Academy of Sciences of the Ukrainian SSR and obtained the degree of Kandidat Nauk (Candidate of Sciences, equivalent to a Ph.D.) in 1928, at the age of 19, with the doctoral thesis titled On direct methods of variational calculus. In 1930, at the age of 21, he obtained the degree of Doktor nauk (Doctor of Sciences, equivalent to Habilitation), the highest degree in the Soviet Union, which requires the recipient to have made a significant independent contribution to his or her scientific field.
This early period of Bogolyubov's work in science was concerned with such mathematical problems as direct me |
https://en.wikipedia.org/wiki/Ars%20cantus%20mensurabilis | Ars cantus mensurabilis (Latin for the art of the measurable song) is a music theory treatise from the mid-13th century, c. 1250–1280 written by German music theorist Franco of Cologne. The treatise was written shortly after De Mensurabili Musica, a treatise by Johannes de Garlandia, which summarised a set of six rhythmic modes in use at the time. In music written in rhythmic modes, the duration of a note could be determined only in context. Ars cantus mensurabilis was the first treatise to suggest that individual notes could have their own durations independent of context. This new rhythmic system was the foundation for the mensural notation system and the ars nova style. |
https://en.wikipedia.org/wiki/E0%20%28cipher%29 | E0 is a stream cipher used in the Bluetooth protocol. It generates a sequence of pseudorandom numbers and combines it with the data using the XOR operator. The key length may vary, but is generally 128 bits.
Description
At each iteration, E0 generates a bit using four shift registers of differing lengths (25, 31, 33, 39 bits) and two internal states, each 2 bits long. At each clock tick, the registers are shifted and the two states are updated with the current state, the previous state and the values in the shift registers. Four bits are then extracted from the shift registers and added together. The algorithm XORs that sum with the value in the 2-bit register. The first bit of the result is output for the encoding.
E0 is divided in three parts:
Payload key generation
Keystream generation
Encoding
The setup of the initial state in Bluetooth uses the same structure as the random bit stream generator. We are thus dealing with two combined E0 algorithms. An initial 132-bit state is produced at the first stage using four inputs (the 128-bit key, the Bluetooth address on 48 bits and the 26-bit master counter). The output is then processed by a polynomial operation and the resulting key goes through the second stage, which generates the stream used for encoding. The key has a variable length, but is always a multiple of 2 (between 8 and 128 bits). 128 bit keys are generally used. These are stored into the second stage's shift registers. 200 pseudorandom bits are then produced by 200 clock ticks, and the last 128 bits are inserted into the shift registers. It is the stream generator's initial state.
Cryptanalysis
Several attacks and attempts at cryptanalysis of E0 and the Bluetooth protocol have been made, and a number of vulnerabilities have been found.
In 1999, Miia Hermelin and Kaisa Nyberg showed that E0 could be broken in 264 operations (instead of 2128), if 264 bits of output are known. This type of attack was subsequently improved by Kishan Chand Gupta an |
https://en.wikipedia.org/wiki/Lamebook | Lamebook is a blog that re-posts 'everything lame and funny' from the social networking site Facebook. Users send in screenshots of unusual or amusing Facebook posts, which are re-posted on the site every weekday.
History
Jonathan Standefer and Matthew Genitempo, graphic designers from Austin, Texas, launched the web site in April 2009 as a Facebook parody site.
The two were acquaintances at Baylor University, yet became friends after they graduated in 2005. "We started Lamebook a little [after meeting], and after a few months of doing that it got so popular that we were able to quit our jobs at the offices and do that full time," said Genitempo, who graduated in 2007 with a degree in graphic design. "That brought a lot of other different design opportunities for both of us."
Privacy
Last names and faces are usually blurred out or pixellated upon upload to avoid invasion of privacy, and content can be removed on request. Lamebook also discourages users from trying to contact people seen in posts.
Oversharing
Sites such as Lamebook would not be in existence without the concept of oversharing. "Overshare," the Word of the Year in 2008 at Webster's New World® College Dictionary, is defined as too much information that is either intentionally or accidentally revealed. The editors of Webster's New World explain that this is a new word for an old phenomenon that has been made much easier by the emergence of modern technology. This ease, combined with the wide reach that many social networking sites allow users to have, has made oversharing quite a common occurrence today. According to the Huffington Post, of online oversharers, 32% say that they have experienced "poster’s remorse" and regretted posting certain information about themselves. Lamebook cocreator Jonathan Standefer, was quoted saying "People overshare on the Internet. My favorite ones used to be the mushy ones, but the fights are the funniest. It's like fighting drunk with one of your friends, but everyone |
https://en.wikipedia.org/wiki/Netherlands%20Mycological%20Society | The Netherlands Mycological Society (Dutch: Nederlandse Mycologische Vereniging (NMV)) is the national society for the Netherlands promoting the study of fungi. It was founded in 1908 and currently has around 800 members. It publishes the journal Coolia as well as various other ad hoc publications, and organises national meetings, courses and mycological excursions.
The society is part of the Pan-European Species directories Infrastructure (PESI). |
https://en.wikipedia.org/wiki/Growth%20Factors%20%28journal%29 | Growth Factors is a bimonthly peer-reviewed scientific journal that covers research on the control of cell production and differentiation and survival. It is published by Informa Healthcare. The editor-in-chief is Steven Stacker (Peter MacCallum Cancer Centre).
External links
Academic journals established in 1989
Molecular and cellular biology journals
Growth factors
Taylor & Francis academic journals
English-language journals
Bimonthly journals |
https://en.wikipedia.org/wiki/Ordinal%20arithmetic | In the mathematical field of set theory, ordinal arithmetic describes the three usual operations on ordinal numbers: addition, multiplication, and exponentiation. Each can be defined in essentially two different ways: either by constructing an explicit well-ordered set that represents the result of the operation or by using transfinite recursion. Cantor normal form provides a standardized way of writing ordinals. In addition to these usual ordinal operations, there are also the "natural" arithmetic of ordinals and the nimber operations.
Addition
The union of two disjoint well-ordered sets S and T can be well-ordered. The order-type of that union is the ordinal that results from adding the order-types of S and T. If two well-ordered sets are not already disjoint, then they can be replaced by order-isomorphic disjoint sets, e.g. replace S by {0} × S and T by {1} × T. This way, the well-ordered set S is written "to the left" of the well-ordered set T, meaning one defines an order on S T in which every element of S is smaller than every element of T. The sets S and T themselves keep the ordering they already have.
The definition of addition α + β can also be given by transfinite recursion on β:
α + 0 = α
, where S denotes the successor function.
when β is a limit ordinal.
Ordinal addition on the natural numbers is the same as standard addition. The first transfinite ordinal is ω, the set of all natural numbers, followed by ω + 1, ω + 2, etc. The ordinal ω + ω is obtained by two copies of the natural numbers ordered in the usual fashion and the second copy completely to the right of the first. Writing 0' < 1' < 2' < ... for the second copy, ω + ω looks like
0 < 1 < 2 < 3 < ... < 0' < 1' < 2' < ...
This is different from ω because in ω only 0 does not have a direct predecessor while in ω + ω the two elements 0 and 0' do not have direct predecessors.
Properties
Ordinal addition is, in general, not commutative. For example, since the order relation for is |
https://en.wikipedia.org/wiki/David%20Negrete%20Fern%C3%A1ndez | David Negrete Fernández () was a Mexican colonel who participated in the Mexican Revolution. He was also a musician.
Biography
David fought alongside military officer Felipe Ángeles as a part of División del Norte.
He married Emilia Moreno Anaya, who bore him:
Consuelo Negrete Moreno
Jorge Alberto Negrete Moreno
Emilia Negrete Moreno
Teresa Negrete Moreno
David Negrete Moreno
Rubén Negrete Moreno
David was a math teacher in Mexico City. He was also a father-in-law of Elisa Christy and María Félix.
See also
Enrique Álvarez Félix, David's step-grandson
Miguel Negrete, relative of David Negrete |
https://en.wikipedia.org/wiki/Useless%20machine | A useless machine or useless box is a device whose only function is to turn itself off. The best-known useless machines are those inspired by Marvin Minsky's design, in which the device's sole function is to switch itself off by operating its own "off" switch. Such machines were popularised commercially in the 1960s, sold as an amusing engineering hack, or as a joke.
More elaborate devices and some novelty toys, which have an obvious entertainment function, have been based on these simple useless machines.
History
The Italian artist Bruno Munari began building "useless machines" (macchine inutili) in the 1930s. He was a "third generation" Futurist and did not share the first generation's boundless enthusiasm for technology, but sought to counter the threats of a world under machine rule by building machines that were artistic and unproductive.
The version of the useless machine that became famous in information theory (basically a box with a simple switch which, when turned "on", causes a hand or lever to appear from inside the box that switches the machine "off" before disappearing inside the box again) appears to have been invented by MIT professor and artificial intelligence pioneer Marvin Minsky, while he was a graduate student at Bell Labs in 1952. Minsky dubbed his invention the "ultimate machine", but that sense of the term did not catch on. The device has also been called the "Leave Me Alone Box".
Minsky's mentor at Bell Labs, information theory pioneer Claude Shannon (who later also became an MIT professor), made his own versions of the machine. He kept one on his desk, where science fiction author Arthur C. Clarke saw it. Clarke later wrote, "There is something unspeakably sinister about a machine that does nothing—absolutely nothing—except switch itself off", and he was fascinated by the concept.
Minsky also invented a "gravity machine" that would ring a bell if the gravitational constant were to change, a theoretical possibility that is not expected |
https://en.wikipedia.org/wiki/Al-Salam%E2%80%93Carlitz%20polynomials | In mathematics, Al-Salam–Carlitz polynomials U(x;q) and V(x;q) are two families of basic hypergeometric orthogonal polynomials in the basic Askey scheme, introduced by . give a detailed list of their properties.
Definition
The Al-Salam–Carlitz polynomials are given in terms of basic hypergeometric functions by |
https://en.wikipedia.org/wiki/Andy%20and%20Bill%27s%20law | Andy and Bill's law is a statement that new software will always consume any increase in computing power that new hardware can provide. The law originates from a humorous one-liner told in the 1990s during computing conferences: "what Andy giveth, Bill taketh away." The phrase is a riff upon the business strategies of former Intel CEO Andy Grove and former Microsoft CEO Bill Gates. Intel and Microsoft had entered into a lucrative partnership in the 1980s through to the 1990s, and the standard chipsets in Microsoft Windows were Intel brand. Despite the profit Intel gained from the deal, Grove felt that Gates was not making full use of the powerful capabilities of Intel chips, and that he was in fact refusing to upgrade his software to achieve optimum hardware performance. Grove's frustration with the dominance of Microsoft software over Intel hardware became public, which spawned the humorous catchphrase; and, later, the law.
See also
Jevons paradox
Moore's law
Wirth%27s law |
https://en.wikipedia.org/wiki/Sabouraud%20agar | Sabouraud agar or Sabouraud dextrose agar (SDA) is a type of agar growth medium containing peptones. It is used to cultivate dermatophytes and other types of fungi, and can also grow filamentous bacteria such as Nocardia. It has utility for research and clinical care.
It was created by, and is named after, Raymond Sabouraud in 1892. In 1977 the formulation was adjusted by Chester W. Emmons when the pH level was brought closer to the neutral range and the dextrose concentration lowered to support the growth of other microorganisms. The acidic pH (5.6) of traditional Sabouraud agar inhibits bacterial growth. Peptones are complex digests and can be a source of variability in Sabouraud agar.
Typical composition
Sabouraud agar is commercially available and typically contains:
40 g/L dextrose
10 g/L peptone
20 g/L agar
pH 5.6
Medical use
Clinical laboratories can use this growth medium to diagnose and further speciate fungal infections, allowing medical professionals to provide appropriate treatment with antifungal medications. Histoplasma and other fungal causes of atypical pneumonia can be grown on this medium. Sabouraud agar used in combination with additional media, such as Inhibitory Mold Agar (IMA), improves identification of fungal clinical isolates. |
https://en.wikipedia.org/wiki/Reactor%20pattern | The reactor software design pattern is an event handling strategy that can respond to many potential service requests concurrently. The pattern's key component is an event loop, running in a single thread or process, which demultiplexes incoming requests and dispatches them to the correct request handler.
By relying on event-based mechanisms rather than blocking I/O or multi-threading, a reactor can handle many concurrent I/O bound requests with minimal delay.
A reactor also allows for easily modifying or expanding specific request handler routines, though the pattern does have some drawbacks and limitations.
With its balance of simplicity and scalability, the reactor has become a central architectural element in several server applications and software frameworks for networking. Derivations such as the multireactor and proactor also exist for special cases where even greater throughput, performance, or request complexity are necessary.
Overview
Practical considerations for the client–server model in large networks, such as the C10k problem for web servers, were the original motivation for the reactor pattern.
A naive approach to handle service requests from many potential endpoints, such as network sockets or file descriptors, is to listen for new requests from within an event loop, then immediately read the earliest request. Once the entire request has been read, it can be processed and forwarded on by directly calling the appropriate handler. An entirely "iterative" server like this, which handles one request from start-to-finish per iteration of the event loop, is logically valid. However, it will fall behind once it receives multiple requests in quick succession. The iterative approach cannot scale because reading the request blocks the server's only thread until the full request is received, and I/O operations are typically much slower than other computations.
One strategy to overcome this limitation is multi-threading: by immediately splitting off each n |
https://en.wikipedia.org/wiki/Mobile%20identity%20management | Mobile identity is a development of online authentication and digital signatures, where the SIM card of one’s mobile phone works as an identity tool. Mobile identity enables legally binding authentication and transaction signing for online banking, payment confirmation, corporate services, and consuming online content. The user's certificates are maintained on the telecom operator's SIM card and in order to use them, the user has to enter a personal, secret PIN code. When using mobile identity, no separate card reader is needed, as the phone itself already performs both functions.
In contrast to other approaches, the mobile phone in conjunction with a mobile signature-enabled SIM card aims to offer the same security and ease of use as for example smart cards in existing digital identity management systems. Smart card-based digital identities can only be used in conjunction with a card reader and a PC. In addition, distributing and managing the cards can be logistically difficult, exacerbated by the lack of interoperability between services relying on such a digital identity.
There are a number of private company stakeholders that have an inherent interest in setting up a mobile signature service infrastructure to offer mobile identity services. These stakeholders are mobile network operators and, to a certain extent, financial institutions or service providers with an existing large customer base, that could leverage the use of mobile signatures across several applications.
By country
Finland
The Finnish government has supervised the deployment of a common derivative of the ETSI-based mobile signature service standard, thus allowing the Finnish mobile operators to offer mobile signature services. The Finnish government certificate authority (CA) also issues the certificates that link the digital keys on the SIM card to the person’s real world identity.
Islamic Republic of Iran
Through national mobile register program Iranian customs administration and ministr |
https://en.wikipedia.org/wiki/Rydberg%20formula | In atomic physics, the Rydberg formula calculates the wavelengths of a spectral line in many chemical elements. The formula was primarily presented as a generalization of the Balmer series for all atomic electron transitions of hydrogen. It was first empirically stated in 1888 by the Swedish physicist Johannes Rydberg, then theoretically by Niels Bohr in 1913, who used a primitive form of quantum mechanics. The formula directly generalizes the equations used to calculate the wavelengths of the hydrogen spectral series.
History
In 1890, Rydberg proposed on a formula describing the relation between the wavelengths in spectral lines of alkali metals. He noticed that lines came in series and he found that he could simplify his calculations using the wavenumber (the number of waves occupying the unit length, equal to 1/λ, the inverse of the wavelength) as his unit of measurement. He plotted the wavenumbers (n) of successive lines in each series against consecutive integers which represented the order of the lines in that particular series. Finding that the resulting curves were similarly shaped, he sought a single function which could generate all of them, when appropriate constants were inserted.
First he tried the formula: , where n is the line's wavenumber, n0 is the series limit, m is the line's ordinal number in the series, m is a constant different for different series and C0 is a universal constant. This did not work very well.
Rydberg was trying: when he became aware of Balmer's formula for the hydrogen spectrum In this equation, m is an integer and h is a constant (not to be confused with the later Planck constant).
Rydberg therefore rewrote Balmer's formula in terms of wavenumbers, as .
This suggested that the Balmer formula for hydrogen might be a special case with and , where , the reciprocal of Balmer's constant (this constant h is written B''' in the Balmer equation article, again to avoid confusion with Planck's constant).
The term was found |
https://en.wikipedia.org/wiki/George%20C.%20Papanicolaou | George C. Papanicolaou (; born January 23, 1943) is a Greek-American mathematician who specializes in applied and computational mathematics, partial differential equations, and stochastic processes. He is currently the Robert Grimmett Professor in Mathematics at Stanford University.
Biography
Papanicolaou was born on January 23, 1943, in Athens, Greece. He received his B.E.E. from Union College and his M.S. and Ph.D. from New York University (NYU) in 1969. His PhD thesis, performed under the supervision of Joseph Bishop Keller was entitled "On Stochastic Differential Equations and Applications". At NYU, he started out as an assistant professor in 1969 before moving up to associate professor in 1973 and finally professor in 1976. Later, in 1993, he relocated to Stanford.
He has had 42 doctoral students and 220 descendants. He is married, with three children.
Publications
Papanicolaou has more than 250 publications on a wide range of topics, including imaging, communications and time reversal, waves in random media, convection-diffusion, nonlinear waves, high contrast materials, mathematical finance, and homogenization.
Recognition
George Papanicolaou is a member of the National Academy of Sciences, and he is a Fellow of the American Academy of Arts and Sciences, the American Mathematical Society (AMS), and the Society for Industrial and Applied Mathematics (SIAM). He was a plenary speaker at the International Congress of Mathematicians in 1998 and the International Congress of Industrial and Applied Mathematics (ICIAM) in 2003. He was awarded a Sloan Research Fellowship (1974), a Guggenheim Fellowship (1983), the von Neumann Lectureship from SIAM (2006), the William Benter Prize in Applied Mathematics (2010), the Gibbs Lectureship of the AMS (2011), and the Lagrange Prize from ICIAM (2019). He received an Honorary Doctor of Science, University of Athens in 1987 and a Doctor Honoris Causa, University of Paris VII in 2011.
Books
"Asymptotic Analysis for Periodi |
https://en.wikipedia.org/wiki/Zinc%20finger%20protein%20507 | Zinc finger protein 507 is a protein that in humans is encoded by the ZNF507 gene. |
https://en.wikipedia.org/wiki/TRIM33 | E3 ubiquitin-protein ligase TRIM33, also known as (ectodermin homolog and tripartite motif-containing 33) is a protein encoded in the human by the gene TRIM33, a member of the tripartite motif family.
TRIM33 is thought to be a transcriptional corepressor. However unlike the related TRIM24 and TRIM28 proteins, few transcription factors such as SMAD4 that interact with TRIM33 have been identified.
Structure
The protein is a member of the tripartite motif family. This motif includes three zinc-binding domains:
RING
B-box type 1 zinc finger
B-box type 2 zinc finger
and a coiled-coil region.
Three alternatively spliced transcript variants for this gene have been described, however, the full-length nature of one variant has not been determined.
Interactions
TRIM33 has been shown to interact with TRIM24.
Role in cancer
TRIM33 acts as a tumor suppressor gene preventing the development chronic myelomonocytic leukemia.
TRIM33 regulates also the TRIM28 receptor and promotes physiological aging of hematopoietic stem cells.
TRIM33 acts as an oncogene by preventing apoptosis in B-cell leukemias. |
https://en.wikipedia.org/wiki/Synonymous%20substitution | A synonymous substitution (often called a silent substitution though they are not always silent) is the evolutionary substitution of one base for another in an exon of a gene coding for a protein, such that the produced amino acid sequence is not modified. This is possible because the genetic code is "degenerate", meaning that some amino acids are coded for by more than one three-base-pair codon; since some of the codons for a given amino acid differ by just one base pair from others coding for the same amino acid, a mutation that replaces the "normal" base by one of the alternatives will result in incorporation of the same amino acid into the growing polypeptide chain when the gene is translated. Synonymous substitutions and mutations affecting noncoding DNA are often considered silent mutations; however, it is not always the case that the mutation is silent.
Since there are 22 codes for 64 codons, roughly we should expect a random substitution to be synonymous with probability about 22/64 = 34%. The actual value is around 20%.
A synonymous mutation can affect transcription, splicing, mRNA transport, and translation, any of which could alter the resulting phenotype, rendering the synonymous mutation non-silent. The substrate specificity of the tRNA to the rare codon can affect the timing of translation, and in turn the co-translational folding of the protein. This is reflected in the codon usage bias that is observed in many species. A nonsynonymous substitution results in a change in amino acid that may be arbitrarily further classified as conservative (a change to an amino acid with similar physiochemical properties), semi-conservative (e.g. negatively to positively charged amino acid), or radical (vastly different amino acid).
Degeneracy of the genetic code
Protein translation involves a set of twenty amino acids. Each of these amino acids is coded for by a sequence of three DNA base pairs called a codon. Because there are 64 possible codons, but only 20-22 |
https://en.wikipedia.org/wiki/Football%20Manager%20%281982%20video%20game%29 | Football Manager is the first game in the Football Manager series.
Gameplay
The game was written entirely in BASIC and, apart from the match highlights on some versions, used only text displays and keyboard entry. The player chooses a team and then must try to earn promotion from the fourth to the first division (although the player can then keep playing for as many seasons as they wish). The player also competes in the FA Cup. Though the team and player names are real, they are not accurately represented, so whichever team is selected, the player always starts in the fourth division and their team is randomly populated with players. Each player has a skill rating and an energy rating. Players must be rested to renew their energy rating or they become injured. The players' skill and energy ratings also change at the end of the season. The team has ratings of defence, midfield and attack (the total skills of all defenders, midfielders or attackers selected), energy (an average of all selected players) and morale (which increases when the team wins and decreases when they lose). The player can select their team to balance the skills based on the opposing team's ratings (e.g. to increase the defence rating if the opposition has a high attack rating).
As the match is played, the screen is updated if a goal is scored. For versions with animated graphics highlights, attempts on goal are shown in isometric 3D at either end of the pitch with a scoreboard showing the current score. The player cannot affect the game while it is in progress.
The player must also balance finances. Weekly income and expenditure is calculated and bank loans can be taken out. There is also a basic player transfer system. Random players become available to buy which the player can bid for. If the squad reaches the maximum of 16, no players will be available to buy. The player can also list their own players for sale and then accept or reject bids.
Game progress can be saved at any time. A custo |
https://en.wikipedia.org/wiki/Principle%20of%20marginality | In statistics, the principle of marginality is the fact that the average (or main) effects of variables in an analysis are marginal to their interaction effect—that is, the main effect of one explanatory variable captures the effect of that variable averaged over all values of a second explanatory variable whose value influences the first variable's effect. The principle of marginality implies that, in general, it is wrong to test, estimate, or interpret main effects of explanatory variables where the variables interact or, similarly, to model interaction effects but delete main effects that are marginal to
them. While such models are interpretable, they lack applicability, as they ignore the dependence of a variable's effect upon another variable's value.
Nelder and Venables have argued strongly for the importance of this principle in regression analysis.
Regression form
If two independent continuous variables, say x and z, both influence a dependent variable y, and if the extent of the effect of each independent variable depends on the level of the other independent variable then the regression equation can be written as:
where i indexes observations, a is the intercept term, b, c, and d are effect size parameters to be estimated, and e is the error term.
If this is the correct model, then the omission of any of the right-side terms would be incorrect, resulting in misleading interpretation of the regression results.
With this model, the effect of x upon y is given by the partial derivative of y with respect to x; this is , which depends on the specific value at which the partial derivative is being evaluated. Hence, the main effect of x – the effect averaged over all values of z – is meaningless as it depends on the design of the experiment (specifically on the relative frequencies of the various values of z) and not just on the underlying relationships. Hence:
In the case of interaction, it is wrong to try to test, estimate, or interpret a "main effect |
https://en.wikipedia.org/wiki/Physica%20%28journal%29 | Physica is a Dutch series of peer-reviewed, scientific journals of physics by Elsevier.
It started out in 1921 as a journal of the Nederlandse Natuurkundige Vereniging (Netherlands Physical Society) that published mostly in Dutch. In 1934 it was taken over by the North-Holland Publishing Company, keeping the same name but with a new volume numbering.
The single journal Physica was split in a three-part series in 1975 (Physica A, Physica B, Physica C). Physica D was created in 1980, and Physica E in 1998. It was published in Utrecht until 2007, and is now published in Amsterdam by Elsevier.
Physica A: Statistical Mechanics and its Applications
Physica A was created in 1975 as a result of the splitting of Physica in 1975. It is concerned with statistical mechanics and its applications, particularly random systems, fluids and soft condensed matter, dynamical processes, theoretical biology, econophysics, complex systems, and network theory.
Physica A is published by Elsevier on a bimonthly basis (24 times per year).
Physica B: Condensed Matter
Physica B was created in 1975 as a result of the splitting of Physica in 1975. It is concerned with condensed matter physics and its applications, particularly solid state and low-temperature physics. Some conference proceedings are published in special editions of Physica B.
Physica B is published by Elsevier on an at-least monthly basis (12 times per year, sometimes more).
Physica C: Superconductivity and its Applications
Physica C created in 1975 as a result of the splitting of Physica in 1975. It is a "rapid communications" type of journal, concerned with the topic superconductivity, superconductive materials, and connected phenomena.
Physica C is published by Elsevier, two or three times per month.
Physica D: Nonlinear Phenomena
Physica D was created in 1980 as an expansion of the Physica series. It is concerned with nonlinear physics and nonlinear phenomena in general.
Physica D is published by Elsevier on a bimont |
https://en.wikipedia.org/wiki/Sunsphere | The Sunsphere located in World’s Fair Park in downtown Knoxville, Tennessee, is a high hexagonal steel truss structure, topped with a gold-colored glass sphere that served as the symbol of the 1982 World's Fair.
Design
Designed by the Knoxville-based architectural firm Community Tectonics, the Sunsphere was created as the theme structure for the 1982 World's Fair. It was noted for its unique design in several engineering publications.
The World's Fair site later became a public park, the World's Fair Park, alongside Knoxville's official convention center and adjacent to the University of Tennessee's main campus. The Sunsphere remains standing directly across a man-made pond from the Tennessee Amphitheater, the only other structure remaining from the 1982 World's Fair.
In its original design, the sphere portion was to have had a diameter of to represent symbolically the diameter sun. The tower's window glass panels are layered in 24-karat gold dust and cut to seven different shapes. It weighs and features six double steel truss columns in supporting the seven-story sphere. The tower has a volume of and a surface of .
History
During the fair it cost to take the elevator to the tower's observation deck. The tower served as a restaurant and featured food items such as the Sunburger and a rum and fruit juice cocktail called the Sunburst. In the early morning hours on May 12, 1982, a shot was fired from outside the fair site and shattered one of the sphere's windows. No one was arrested for the incident.
The Sunsphere has been used as a symbol for Knoxville, appearing in postcards and logos. Between 1993 and 1999, the Sunsphere was featured in part on the logo for the Knoxville Smokies minor league baseball club. The 2002 AAU Junior Olympics mascot Spherit took its inspiration from the landmark. It featured red hair and a body shaped like the Sunsphere. On Sunday, May 14, 2000, nuclear weapons protesters scaled the tower and hung a large banner that said "St |
https://en.wikipedia.org/wiki/GPM%20J1839%E2%88%9210 | GPM J1839−10 is a potentially unique ultra-long period magnetar located about 15,000 light-years away from Earth in the Scutum constellation, in the Milky Way. It was discovered by a team of scientists at Curtin University using the Murchison Widefield Array. Its unusual characteristics violate current theory and prompted a search of other radio telescope archives, including the Giant Metrewave Radio Telescope and the Very Large Array, which revealed evidence of the object dating back to 1988. The signature of the object went unnoticed because scientists did not know to look for its unusual behavior.
The current understanding of neutron stars is that below a certain rate of rotation, called "the death line", they cease emissions. Uniquely, not only does GPM J1839−10 have an extremely slow rotation of approximately twenty-two minutes, it emits bursts of radio waves lasting up to five minutes, for which there is currently no generally accepted explanation.
See also
GLEAM-X J162759.5−523504.3
GCRT J1745−3009
PSR J0901–4046
Further reading
Not open access. |
https://en.wikipedia.org/wiki/Evolution%20of%20a%20random%20network | Evolution of a random network is a dynamical process, usually leading to emergence of giant component accompanied with striking consequences on the network topology. To quantify this process, there is a need of inspection on how the size of the largest connected cluster within the network, , varies with the average degree . Networks change their topology as they evolve, undergoing phase transitions. Phase transitions are generally known from physics, where it occurs as matter changes state according to its thermal energy level, or when ferromagnetic properties emerge in some materials as they are cooling down. Such phase transitions take place in matter because it is a network of particles, and as such, rules of network phase transition directly apply to it. Phase transitions in networks happen as links are added to a network, meaning that having N nodes, in each time increment, a link is placed between a randomly chosen pair of them. The transformation from a set of disconnected nodes to a fully connected network is called the evolution of a network.
If we begin with a network having N totally disconnected nodes (number of links is zero), and start adding links between randomly selected pairs of nodes, the evolution of the network begins. For some time we will just create pairs of nodes. After a while some of these pairs will connect, forming little trees. As we continue adding more links to the network, there comes a point when a giant component emerges in the network as some of these isolated trees connect to each other. This is called the critical point. In our natural example, this point corresponds to temperatures where materials change their state. Further adding nodes to the system, the giant component becomes even larger, as more and more nodes get a link to another node which is already part of the giant component. The other special moment in this transition is when the network becomes fully connected, that is, when all nodes belong to the one giant compo |
https://en.wikipedia.org/wiki/Phoner | Phoner and PhonerLite are softphone applications for Windows operating systems available as freeware. Phoner is a multiprotocol telephony application supporting telephony via CAPI, TAPI and VoIP, while PhonerLite provides a specialized and optimized user interface for VoIP only. Beside the different user interface focus both programs share the same code base.
Both programs use the Session Initiation Protocol for VoIP call signalisation. Calls are supported via server-based infrastructure or direct IP to IP. Media streams are transmitted via the Real-time Transport Protocol which may be encrypted with the Secure Real-time Transport Protocol (SRTP) and the ZRTP security protocols. Phoner provides as well an interface for configuring and using all supplementary ISDN services provided via CAPI and thus needs an ISDN terminal adapter hardware installed in the computer.
Both programs support IPv4 and IPv6 connections by using UDP, TCP and TLS.
Supported audio formats
G.711 A-law: 64 kbit/s payload, 8 kHz sampling rate
G.711 μ-law: 64 kbit/s payload, 8 kHz sampling rate
G.722: 64 kbit/s payload, 16 kHz sampling rate
G.726: 16, 24, 32 or 40 kbit/s payload, 8 kHz sampling rate
GSM: 13 kbit/s payload, 8 kHz sampling rate
iLBC: 13.3 or 15.2 kbit/s payload, 8 kHz sampling rate
Speex narrow band: 15 kbit/s payload, 8 kHz sampling rate
Speex wide band: 30 kbit/s payload, 16 kHz sampling rate
Opus: 10-50 kbit/s, up to 48 kHz sampling rate
G.729: 8 kbit/s payload, 8 kHz sampling rate
Linear PCM: 705 kbit/s payload, 44.1 kHz sampling rate
See also
Comparison of VoIP software
List of SIP software
Opportunistic encryption |
https://en.wikipedia.org/wiki/TB9Cs1H1%20snoRNA | TB9Cs1H1 is a member of the H/ACA-like class of non-coding RNA (ncRNA) molecule that guide the sites of modification of uridines to pseudouridines of substrate RNAs. It is known as a small nucleolar RNA (snoRNA) thus named because of its cellular localization in the nucleolus of the eukaryotic cell. TB9Cs1H1 is predicted to guide the pseudouridylation of LSU3 ribosomal RNA (rRNA) at residue Ψ1273 and SSU ribosomal RNA (rRNA) at residue Ψ1088. |
https://en.wikipedia.org/wiki/Wellmania | Wellmania is an Australian comedy-drama streaming television series co-created by Brigid Delaney and Benjamin Law for Netflix. Based on Delaney's memoir-reportage hybrid, Wellmania: Misadventures in the Search for Wellness, it follows Liv Healy (Celeste Barber), a 39-year-old woman who struggles with a "major health crisis" as she tries various methods to reclaim her well-being. The series launched globally on the streaming platform on 29 March 2023.
Premise
Liv Healy, a New York-based food writer with an unhealthy lifestyle, recently receives an opportunity that forces her to reevaluate her choices in her hometown of Sydney, Australia. Struggling with her previous habits, she tries various methods of healthy living in order to advance her career to varying levels of success.
Cast
Main
Celeste Barber as Olivia "Liv" Healy, New York Times food writer
Olive McKinnon plays a younger Liv Healy
JJ Fong as Amy Kwan, an investigative journalist from The Standard Sydney who is Liv's best friend of 24 years
Heleina Zara plays a younger Amy Kwan
Genevieve Mooy as Lorraine Healy, Liv's mother who works as a nurse
Lachlan Buchanan as Gareth "Gaz" Healy, Liv's brother and fitness trainer
Remy Hii as Dalbert Tan, Gaz's fiancé
Alexander Hodge as Isaac Huang, ex-football player who is Liv's love interest
Simone Kessell as Helen King, editor-in-chief of The Standard Sydney
Virginie Laverdure as Valerie Jones, Liv's editor from New York Times
Johnny Carr as Doug Henderson, Amy's husband who is a construction worker
Recurring
Leah Vandenberg as Dr. Priyanka Singh, consulate-approved physician
Anthony Phelan as Dr. Price, Lorraine's employer and physician
Guy Edmonds as Chad, United States consulate official
Billy Bate as Archie Henderson-Kwan, Amy and Doug's son
Kiera McAlister as Evie Henderson-Kwan, Amy and Doug's teenage daughter
Claire Lovering as Bianga, Dalbert's close friend
Nicole Shostak as Megan, Dalbert's close friend
Matthew Backer as Armand, |
https://en.wikipedia.org/wiki/Network%20allocation%20vector | The network allocation vector (NAV) is a virtual carrier-sensing mechanism used with wireless network protocols such as IEEE 802.11 (Wi-Fi) and IEEE 802.16 (WiMax). The virtual carrier-sensing is a logical abstraction which limits the need for physical carrier-sensing at the air interface in order to save power. The MAC layer frame headers contain a duration field that specifies the transmission time required for the frame, in which time the medium will be busy. The stations listening on the wireless medium read the Duration field and set their NAV, which is an indicator for a station on how long it must defer from accessing the medium.
The NAV may be thought of as a counter, which counts down to zero at a uniform rate. When the counter is zero, the virtual carrier-sensing indication is that the medium is idle; when nonzero, the indication is busy. The medium shall be determined to be busy when the station (STA) is transmitting. In IEEE 802.11, the NAV represents the number of microseconds the sending STA intends to hold the medium busy (maximum of 32,767 microseconds). When the sender sends a Request to Send the receiver waits one SIFS before sending Clear to Send. Then the sender will wait again one SIFS before sending all the data. Again the receiver will wait a SIFS before sending ACK. So NAV is the duration from the first SIFS to the ending of ACK. During this time the medium is considered busy.
Wireless stations are often battery-powered, so to conserve power the stations may enter a power-saving mode. A station decrements its NAV counter until it becomes zero, at which time it is awakened to sense the medium again.
The NAV virtual carrier sensing mechanism is a prominent part of the CSMA/CA MAC protocol used with IEEE 802.11 WLANs. NAV is used in DCF, PCF and HCF.
Media access control
Computer networking |
https://en.wikipedia.org/wiki/Fundamental%20plane%20%28spherical%20coordinates%29 | The fundamental plane in a spherical coordinate system is a plane of reference that divides the sphere into two hemispheres. The geocentric latitude of a point is then the angle between the fundamental plane and the line joining the point to the centre of the sphere.
For a geographic coordinate system of the Earth, the fundamental plane is the Equator.
Astronomical coordinate systems have varying fundamental planes:
The horizontal coordinate system uses the observer's horizon.
The Besselian coordinate system uses Earth's terminator (day/night boundary). This is a Cartesian coordinate system (x, y, z).
The equatorial coordinate system uses the celestial equator.
The ecliptic coordinate system uses the ecliptic.
The galactic coordinate system uses the Milky Way's galactic equator.
See also
Plane of reference |
https://en.wikipedia.org/wiki/Paul%20Riebesell | Paul Louis Riebesell (9 June 1883, Hamburg – 16 March 1950, Hamburg) was a German mathematician, statistician, actuary, and president of Hamburger Feuerkasse. At the International Congress of Mathematicians, he was an invited speaker in 1932 in Zürich and in 1936 in Oslo.
Biography
Riebesell studied mathematics and natural sciences in Munich, in Berlin, and at the University of Kiel, where he received his doctorate in 1905 under the supervision of Paul Stäckel. After receiving his doctorate, Riebesell was a Studienrat for a number of years in Hamburg. In 1918, he became the second director of the Hamburg Jugendamt. He wrote a commentary on the Reichsgesetz für Jugendwohlfahrt (Youth Welfare Law). He published research on Einstein's theory of relativity. After he habilitated at the University of Hamburg, there at the beginning of the 1920s he was appointed an außerordentlicher Professor (non-tenured professor) in actuarial mathematics and remained in that position until 1934. In 1923, the city of Hamburg appointed him director of Hamburger Feuerkasse. In 1934 he was elected president of the Reichsverband des öffentlich-rechtlichen Versicherung (Reich Association of Public Insurance Companies). in 1937, he lost this position for political reasons. In 1938, he became the director of the life insurance company Isar Lebensversicherungs-AG with headquarters in Munich. He was also a professor honorarius from 1935 to 1940 at the Technische Hochschule Berlin (TH Berlin), from 1935 at the Humboldt University of Berlin, and from 1938 at the Ludwig Maximilian University of Munich. After WW II he returned to Hamburg as president of Hamburger Feuerkasse and held that position until his death in 1950. In 19,48 he co-founded the Deutsche Gesellschaft für Versicherungsmathematik (German Society for Actuarial Mathematics) and became its first chairman.
Riebesell dealt with the influence of currency devaluation on insurance benefits. His achievement in actuarial science lies primari |
https://en.wikipedia.org/wiki/Cranial%20auscultation | Auscultation, a medical neurological procedure, can be performed upon the skull to check for intracranial bruits. Such a bruit may be found in such conditions as cerebral angioma, tumour of the glomus jugulare, intracranial aneurysm, meningioma, occlusion of the internal carotid artery, or increased intracranial pressure.
Clinical observations
The following extract details a method of performing cranial auscultation:
A bruit should be listened for, in quiet surroundings, over the skull and eyeballs, the latter situation being the most favourable for hearing the softest ones. The patient should be asked to close both eyes gently and the stethoscope firmly applied over one eye. During auscultation the other eye should be opened as in this way there is considerable diminution of eyelid flutter, which may cause confusion if rhythmical. Auscultation is then carried out over the other eye in a similar manner. If a murmur is not readily heard the patient should be asked to hold his breath. Finally auscultation should be carried out over the temporal fossæ and mastoid processes.
Notes
Neurology procedures
Neurosurgery |
https://en.wikipedia.org/wiki/Heat%20of%20combustion | The heating value (or energy value or calorific value) of a substance, usually a fuel or food (see food energy), is the amount of heat released during the combustion of a specified amount of it.
The calorific value is the total energy released as heat when a substance undergoes complete combustion with oxygen under standard conditions. The chemical reaction is typically a hydrocarbon or other organic molecule reacting with oxygen to form carbon dioxide and water and release heat. It may be expressed with the quantities:
energy/mole of fuel
energy/mass of fuel
energy/volume of the fuel
There are two kinds of enthalpy of combustion, called high(er) and low(er) heat(ing) value, depending on how much the products are allowed to cool and whether compounds like are allowed to condense.
The high heat values are conventionally measured with a bomb calorimeter. Low heat values are calculated from high heat value test data. They may also be calculated as the difference between the heat of formation ΔH of the products and reactants (though this approach is somewhat artificial since most heats of formation are typically calculated from measured heats of combustion).
By convention, the (higher) heat of combustion is defined to be the heat released for the complete combustion of a compound in its standard state to form stable products in their standard states: hydrogen is converted to water (in its liquid state), carbon is converted to carbon dioxide gas, and nitrogen is converted to nitrogen gas. That is, the heat of combustion, ΔH°comb, is the heat of reaction of the following process:
(std.) + (c + - ) (g) → c (g) + (l) + (g)
Chlorine and sulfur are not quite standardized; they are usually assumed to convert to hydrogen chloride gas and or gas, respectively, or to dilute aqueous hydrochloric and sulfuric acids, respectively, when the combustion is conducted in a bomb calorimeter containing some quantity of water.
Ways of determination
Gross and net
Z |
https://en.wikipedia.org/wiki/Heraldic%20knot | A heraldic knot (referred to in heraldry as simply a knot) is a knot, unknot, or design incorporating a knot used in European heraldry. While a given knot can be used on more than one family's achievement of arms, the family on whose coat the knot originated usually gives its name to the said knot (the exception being the Tristram knot). These knots can be used to charge shields and crests, but can also be used in badges or as standalone symbols of the families for whom they are named (like Scottish plaids). The simplest of these patterns, the Bowen knot, is often referred to as the heraldic knot in symbolism and art outside of heraldry.
Heraldic knots |
https://en.wikipedia.org/wiki/Table%20%28database%29 | A table is a collection of related data held in a table format within a database. It consists of columns and rows.
In relational databases, and flat file databases, a table is a set of data elements (values) using a model of vertical columns (identifiable by name) and horizontal rows, the cell being the unit where a row and column intersect. A table has a specified number of columns, but can have any number of rows. Each row is identified by one or more values appearing in a particular column subset. A specific choice of columns which uniquely identify rows is called the primary key.
"Table" is another term for "relation"; although there is the difference in that a table is usually a multiset (bag) of rows where a relation is a set and does not allow duplicates. Besides the actual data rows, tables generally have associated with them some metadata, such as constraints on the table or on the values within particular columns.
The data in a table does not have to be physically stored in the database. Views also function as relational tables, but their data are calculated at query time. External tables (in Informix
or Oracle,
for example) can also be thought of as views.
In many systems for computational statistics, such as R and Python's pandas, a data frame or data table is a data type supporting the table abstraction. Conceptually, it is a list of records or observations all containing the same fields or columns. The implementation consists of a list of arrays or vectors, each with a name.
Tables versus relations
In terms of the relational model of databases, a table can be considered a convenient representation of a relation, but the two are not strictly equivalent. For instance, a SQL table can potentially contain duplicate rows, whereas a true relation cannot contain duplicate rows that we call tuples. Similarly, representation as a table implies a particular ordering to the rows and columns, whereas a relation is explicitly unordered. However, the database |
https://en.wikipedia.org/wiki/David%20Matula | David William Matula (born 1937) is an American mathematician and computer scientist known for his research on graph theory, graph algorithms, computer arithmetic, and algorithm engineering. He is a professor emeritus at Southern Methodist University, where he formerly held the Cruse C. and Marjorie F. Calahan Centennial Chair in Engineering.
Education and career
Matula was an undergraduate at Washington University in St. Louis, graduating in 1959. He completed his Ph.D. in 1966 at the University of California, Berkeley, with the dissertation Games of Sequence Prediction supervised by David Blackwell.
After completing his Ph.D., he returned to Washington University in St. Louis as a faculty member. He joined the Southern Methodist University faculty in 1974 as chair of the Computer Science and Engineering Department, was named to the Cruse C. and Marjorie F. Calahan Centennial Chair in Engineering in 2016, and retired in 2018.
Book
Matula is the coauthor, with Peter Kornerup, of the book Finite Precision Number Systems and Arithmetic (Encyclopedia of Mathematics and its Applications 133, Cambridge University Press, 2010). |
https://en.wikipedia.org/wiki/Opera%20Omnia%20Leonhard%20Euler | Opera Omnia Leonhard Euler (Leonhardi Euleri Opera omnia) is the compilation of Leonhard Euler's scientific writings. The project of this compilation was undertaken by the Euler Committee of the Swiss Academy of Sciences, established in 1908, and is ongoing . The Committee decided on "the edition of the Collected Works of Leonhard Euler in the original languages, convinced of rendering the entire scientific world a service thereby", and, in 1919, it indicated to collect “All works from Leonhard Euler, hitherto unseen or already printed, coming from St-Petersburg or elsewhere need to be integrated. This also includes the scientific letters of Euler”. The project has been supported by the international community, notably the Petersburg Academy of Sciences where Euler taught and which lent out its Euler materials in 1910. Publishing Euler's Opera Omnia has been termed "one of the most extraordinary projects in publishing".
The Opera Omnia, excepting correspondences still being compiled in IVA9, was made available online in 2022 via the Opera-Bernoulli-Euler, which is working to make "the entire work of Euler, the Bernoulli family and their environment" freely available online.
Euler's writings
During his life, Euler published about 560 writings. After his death in 1783, the Petersburg Academy published more of his manuscripts until 1830, increasing his number of publications to 756. Additional manuscripts were found later by his grandson Paul-Heinrich Fuss and published. Gustav Eneström established an inventory – the Eneström Index – between 1910 and 1913 listing 866 publications, namely E1–E866. Euler's writings are primarily in Latin, French, and German, though some are also in Russian and English. Previous attempts to compile all of Euler's writing had been made prior to the work of the Euler Committee.
The Committee has been publishing the 866 publications of Euler's work since 1911. The work was delayed by two world wars and economic issues. In the second part |
https://en.wikipedia.org/wiki/Intersection%20theorem | In projective geometry, an intersection theorem or incidence theorem is a statement concerning an incidence structure – consisting of points, lines, and possibly higher-dimensional objects and their incidences – together with a pair of objects and (for instance, a point and a line). The "theorem" states that, whenever a set of objects satisfies the incidences (i.e. can be identified with the objects of the incidence structure in such a way that incidence is preserved), then the objects and must also be incident. An intersection theorem is not necessarily true in all projective geometries; it is a property that some geometries satisfy but others don't.
For example, Desargues' theorem can be stated using the following incidence structure:
Points:
Lines:
Incidences (in addition to obvious ones such as ):
The implication is then —that point is incident with line .
Famous examples
Desargues' theorem holds in a projective plane if and only if is the projective plane over some division ring (skewfield} — . The projective plane is then called desarguesian.
A theorem of Amitsur and Bergman states that, in the context of desarguesian projective planes, for every intersection theorem there is a rational identity such that the plane satisfies the intersection theorem if and only if the division ring satisfies the rational identity.
Pappus's hexagon theorem holds in a desarguesian projective plane if and only if is a field; it corresponds to the identity .
Fano's axiom (which states a certain intersection does not happen) holds in if and only if has characteristic ; it corresponds to the identity . |
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