source stringlengths 31 227 | text stringlengths 9 2k |
|---|---|
https://en.wikipedia.org/wiki/ZeroAccess%20botnet | ZeroAccess is a Trojan horse computer malware that affects Microsoft Windows operating systems. It is used to download other malware on an infected machine from a botnet while remaining hidden using rootkit techniques.
History and propagation
The ZeroAccess botnet was discovered at least around May 2011. The ZeroAccess rootkit responsible for the botnet's spread is estimated to have been present on at least 9 million systems. Estimates botnet size vary across sources; antivirus vendor Sophos estimated the botnet size at around 1 million active and infected machines in the third quarter of 2012, and security firm Kindsight estimated 2.2 million infected and active systems.
The bot itself is spread through the ZeroAccess rootkit through a variety of attack vectors. One attack vector is a form of social engineering, where a user is persuaded to execute malicious code either by disguising it as a legitimate file, or including it hidden as an additional payload in an executable that announces itself as, for example, bypassing copyright protection (a keygen). A second attack vector utilizes an advertising network in order to have the user click on an advertisement that redirects them to a site hosting the malicious software itself. Finally, a third infection vector used is an affiliate scheme where third-party persons are paid for installing the rootkit on a system.
In December 2013 a coalition led by Microsoft moved to destroy the command and control network for the botnet. The attack was ineffective though because not all C&C were seized, and its peer-to-peer command and control component was unaffected - meaning the botnet could still be updated at will.
Operation
Once a system has been infected with the ZeroAccess rootkit it will start one of the two main botnet operations: bitcoin mining or click fraud. Machines involved in bitcoin mining generate bitcoins for their controller, the estimated worth of which was 2.7 million US dollars per year in September 2012. |
https://en.wikipedia.org/wiki/NCOA7 | Nuclear receptor coactivator 7 is a protein that in humans is encoded by the NCOA7 gene.
See also
Transcription coregulator |
https://en.wikipedia.org/wiki/Softaculous | Softaculous is a commercial script library that automates the installation of commercial and open source web applications to a website. Softaculous scripts are executed from the administration area of a website control panel, typically via an interface tool such as cPanel, Plesk, DirectAdmin and InterWorx. Softaculous applications typically create tables in a database, install software, adjust permissions, and modify web server configuration files.
Softaculous targets open-source software and is available in Free and Premium license versions. The free version supports 46 scripts. The Premium version has 436 scripts and 1115 PHP Classes.
See also
Installatron – a Softaculous competitor.
Fantastico (web hosting) – a Softaculous competitor.
Integrated hosting control panels
cPanel
DirectAdmin
Plesk
Ispmanager
Interworx
Webuzo |
https://en.wikipedia.org/wiki/Representation%20theory%20of%20the%20Galilean%20group | In nonrelativistic quantum mechanics, an account can be given of the existence of mass and spin (normally explained in Wigner's classification of relativistic mechanics) in terms of the representation theory of the Galilean group, which is the spacetime symmetry group of nonrelativistic quantum mechanics.
In dimensions, this is the subgroup of the affine group on (), whose linear part leaves invariant both the metric () and the (independent) dual metric (). A similar definition applies for dimensions.
We are interested in projective representations of this group, which are equivalent to unitary representations of the nontrivial central extension of the universal covering group of the Galilean group by the one-dimensional Lie group , cf. the article Galilean group for the central extension of its Lie algebra. The method of induced representations will be used to survey these.
We focus on the (centrally extended, Bargmann) Lie algebra here, because it is simpler to analyze and we can always extend the results to the full Lie group through the Frobenius theorem.
is the generator of time translations (Hamiltonian), Pi is the generator of translations (momentum operator), Ci is the generator of Galilean boosts, and Lij stands for a generator of rotations (angular momentum operator). The central charge is a Casimir invariant.
The mass-shell invariant
is an additional Casimir invariant.
In dimensions, a third Casimir invariant is , where
somewhat analogous to the Pauli–Lubanski pseudovector of relativistic mechanics.
More generally, in dimensions, invariants will be a function of
and
as well as of the above mass-shell invariant and central charge.
Using Schur's lemma, in an irreducible unitary representation, all these Casimir invariants are multiples of the identity. Call these coefficients and and (in the case of dimensions) , respectively. Recalling that we are considering unitary representations here, we see that these eigenvalues have to b |
https://en.wikipedia.org/wiki/Lumen%20%28anatomy%29 | In biology, a lumen (: lumina) is the inside space of a tubular structure, such as an artery or intestine. It comes .
It can refer to:
the interior of a vessel, such as the central space in an artery, vein or capillary through which blood flows
the interior of the gastrointestinal tract
the pathways of the bronchi in the lungs
the interior of renal tubules and urinary collecting ducts
the pathways of the female genital tract, starting with a single pathway of the vagina, splitting up in two lumina in the uterus, both of which continue through the fallopian tubes
In cell biology, a lumen is a membrane-defined space that is found inside several organelles, cellular components, or structures, including thylakoid, endoplasmic reticulum, Golgi apparatus, lysosome, mitochondrion, and microtubule.
Transluminal procedures
Transluminal procedures are procedures occurring through lumina, including:
natural orifice transluminal endoscopic surgery in the lumina of, for example, the stomach, vagina, bladder, or colon
procedures through the lumina of blood vessels, such as various interventional radiology procedures:
percutaneous transluminal angioplasty
percutaneous transluminal commissurotomy
See also
Foramen, any anatomical opening |
https://en.wikipedia.org/wiki/Replicate%20%28biology%29 | In the biological sciences, replicates are an experimental units that are treated identically. Replicates are an essential component of experimental design because they provide an estimate of between sample error. Without replicates, scientists are unable to assess whether observed treatment effects are due to the experimental manipulation or due to random error. There are also analytical replicates which is when an exact copy of a sample is analyzed, such as a cell, organism or molecule, using exactly the same procedure. This is done in order to check for analytical error. In the absence of this type of error replicates should yield the same result. However, analytical replicates are not independent and cannot be used in tests of the hypothesis because they are still the same sample.
See also
Self-replication
Fold change |
https://en.wikipedia.org/wiki/Heawood%20conjecture | In graph theory, the Heawood conjecture or Ringel–Youngs theorem gives a lower bound for the number of colors that are necessary for graph coloring on a surface of a given genus. For surfaces of genus 0, 1, 2, 3, 4, 5, 6, 7, ..., the required number of colors is 4, 7, 8, 9, 10, 11, 12, 12, .... , the chromatic number or Heawood number.
The conjecture was formulated in 1890 by Percy John Heawood and proven in 1968 by Gerhard Ringel and Ted Youngs. One case, the non-orientable Klein bottle, proved an exception to the general formula. An entirely different approach was needed for the much older problem of finding the number of colors needed for the plane or sphere, solved in 1976 as the four color theorem by Haken and Appel. On the sphere the lower bound is easy, whereas for higher genera the upper bound is easy and was proved in Heawood's original short paper that contained the conjecture. In other words, Ringel, Youngs and others had to construct extreme examples for every genus g = 1,2,3,.... If g = 12s + k, the genera fall into 12 cases according as k = 0,1,2,3,4,5,6,7,8,9,10,11. To simplify, suppose that case k has been established if only a finite number of g's of the form 12s + k are in doubt. Then the years in which the twelve cases were settled and by whom are the following:
1954, Ringel: case 5
1961, Ringel: cases 3,7,10
1963, Terry, Welch, Youngs: cases 0,4
1964, Gustin, Youngs: case 1
1965, Gustin: case 9
1966, Youngs: case 6
1967, Ringel, Youngs: cases 2,8,11
The last seven sporadic exceptions were settled as follows:
1967, Mayer: cases 18, 20, 23
1968, Ringel, Youngs: cases 30, 35, 47, 59, and the conjecture was proved.
Formal statement
Percy John Heawood conjectured in 1890 that for a given genus g > 0, the minimum number of colors necessary to color all graphs drawn on an orientable surface of that genus (or equivalently to color the regions of any partition of the surface into simply connected regions) is given by
where is the floor function.
Re |
https://en.wikipedia.org/wiki/Bates%E2%80%93Guggenheim%20Convention | In chemistry, the Bates–Guggenheim Convention refers to a conventional method based on the Debye–Hückel theory to determine pH standard values. |
https://en.wikipedia.org/wiki/Software-defined%20networking | Software-defined networking (SDN) technology is an approach to network management that enables dynamic, programmatically efficient network configuration to improve network performance and monitoring, in a manner more akin to cloud computing than to traditional network management. SDN is meant to address the static architecture of traditional networks and may be employed to centralize network intelligence in one network component by disassociating the forwarding process of network packets (data plane) from the routing process (control plane). The control plane consists of one or more controllers, which are considered the brains of the SDN network, where the whole intelligence is incorporated. However, centralization has certain drawbacks related to security, scalability and elasticity.
SDN was commonly associated with the OpenFlow protocol (for remote communication with network plane elements to determine the path of network packets across network switches) since OpenFlow's emergence in 2011. However, since 2012, proprietary systems have also used the term. These include Cisco Systems' Open Network Environment and Nicira's network virtualization platform.
SD-WAN applies similar technology to a wide area network (WAN).
History
The history of SDN principles can be traced back to the separation of the control and data plane first used in public switched telephone networks. This provided a manner of simplifying provisioning and management years before the architecture was used in data networks.
The Internet Engineering Task Force (IETF) began considering various ways to decouple the control and forwarding functions in a proposed interface standard published in 2004 named Forwarding and Control Element Separation (ForCES). The ForCES Working Group also proposed a companion SoftRouter architecture. Additional early standards from the IETF that pursued separating control from data include the Linux Netlink as an IP services protocol and a path computation element (PCE) |
https://en.wikipedia.org/wiki/Desulfovibrio%20bastinii | Desulfovibrio bastinii is a moderately halophilic bacteria. It is sulfate-reducing, mesophilic and motile. Its type strain is SRL4225T (=DSM 16055T =ATCC BAA-903T). |
https://en.wikipedia.org/wiki/Texas%20Neurosciences%20Institute | The Texas Neurosciences Institute (TNI) is the name of a medical office building in San Antonio, Texas.
The building is adjacent to the University of Texas Health Science Center medical school. Medical specialties in the building include pediatrics, pediatric hematology/oncology, gastroenterology, neurosurgery, internal medicine, etc. There are also diagnostic labs and radiology imaging centers located there.
See also
South Texas Medical Center |
https://en.wikipedia.org/wiki/Transverse%20mass | The transverse mass is a useful quantity to define for use in particle physics as it is invariant under Lorentz boost along the z direction. In natural units, it is:
where the z-direction is along the beam pipe and so
and are the momentum perpendicular to the beam pipe and
is the (invariant) mass.
This definition of the transverse mass is used in conjunction with the definition of the (directed) transverse energy
with the transverse momentum vector . It is easy to see that for vanishing mass () the three quantities are the same: .
The transverse mass is used together with the rapidity, transverse momentum and polar angle in the parameterization of the four-momentum of a single particle:
Using these definitions (in particular for ) gives for the mass of a two particle system:
Looking at the transverse projection of this system (by setting ) gives:
These are also the definitions that are used by the software package ROOT, which is commonly used in high energy physics.
Transverse mass in two-particle systems
Hadron collider physicists use another definition of transverse mass (and transverse energy), in the case of a decay into two particles. This is often used when one particle cannot be detected directly but is only indicated by missing transverse energy. In that case, the total energy is unknown and the above definition cannot be used.
where is the transverse energy of each daughter, a positive quantity defined using its true invariant mass as:
,
which is coincidentally the definition of the transverse mass for a single particle given above.
Using these two definitions, one also gets the form:
(but with slightly different definitions for !)
For massless daughters, where , we again have , and the transverse mass of the two particle system becomes:
where is the angle between the daughters in the transverse plane.
The distribution of has an end-point at the invariant mass of the system with . This has been used to determine the mass at the Tevatro |
https://en.wikipedia.org/wiki/Warriors%20Orochi%203 | Warriors Orochi 3, originally released as in Japan, is a 2011 hack and slash video game developed by Tecmo Koei and Omega Force for the PlayStation 3 and Xbox 360. This is the fourth installment of the crossover series Warriors Orochi, a combination of the Dynasty Warriors and Samurai Warriors series. This installment serves as a sequel to Warriors Orochi 2. The game was released in Japan in 2011, in Europe in 2012, and in North America in 2012 (PlayStation 3, Xbox 360).
There are two ports of the game: Musou Orochi 2: Special (), released in 2012 for PlayStation Portable exclusively in Japan, and Warriors Orochi 3: Hyper (), which was released as a launch title for the Wii U for Japan, North America, and Europe. An updated version, Warriors Orochi 3: Ultimate (), was released for the PlayStation 3 and PlayStation Vita in Japan in 2013 with PlayStation 4 and Xbox One ports released in 2014. The four versions were also released in North America and Europe in 2014. An additional port for the Nintendo Switch was released exclusively in Japan in 2017. A definitive edition of the game Warriors Orochi 3: Ultimate Definitive Edition was released worldwide for Microsoft Windows Steam in 12 July 2022. Unlike previous titles, Warriors Orochi 3 only features Japanese voices.
Gameplay
The gameplay of Warriors Orochi 3 is similar to that of the two titles that the Warriors Orochi 3 takes its characters from: namely Dynasty Warriors 7 (specifically, Dynasty Warriors Next) and Samurai Warriors 3. Characters from either of these series play similar to how they play in their respective source games, but with a number of changes to unify the two different games together, including:
Dynasty Warriors characters are solely armed with one weapon, and cannot switch to another one; however, the weapon given to each character is their EX weapon from the series. Characters who have changed their EX weapons in Dynasty Warriors 7: Empires (which was released after Warriors Orochi 3, but be |
https://en.wikipedia.org/wiki/Icelandic%20Arctic%20Cooperation%20Network | The Icelandic Arctic Cooperation Network (IACN) is a non-governmental organization in Iceland creating stronger linkages through inclusive multi-stakeholder membership and network, for the facilitation of cooperation concerning the Arctic region.
The Icelandic government passed a "Governmental Policy Plan for the Economy and Community" called Iceland 20/20. The Icelandic Arctic Cooperation Network, established in 2013, is a part of the implementation process of this policy and the result of a collaboration between the members of the IACN; Eything - a regional body for cooperation between the municipalities in north-east Iceland; the Ministry for Foreign Affairs (Iceland), the Ministry of Education, Science and Culture (Iceland); and the Ministry for the Environment and Natural Resources (Iceland).
Recent additional members include the Centre for Gender Equality; the Fisheries Science Centre at the University of Akureyri; the Husavik Academic Centre; Arctic Services; the Icelandic Met Office; the Marine Research Institute; the Icelandic Maritime Administration; the University Centre of the Westfjords; and the Greenland Centre, also in the Westfjords of Iceland.
IACN's first director is Embla Eir Oddsdóttir.
The Icelandic Arctic Cooperation Network is one of four founders of the Icelandic-Arctic Chamber of Commerce. The other three are the Ministry for Foreign Affairs, Iceland; The Icelandic Chamber of Commerce; and the Federation of Icelandic Industries.
The network is based in the research centre Borgir, in Akureyri, Iceland. |
https://en.wikipedia.org/wiki/Social%20reserves | Social Reserves refer to the intangible ties that bind a country together. As a resource, they may be contrasted to a country's financial reserves. The term bears some similarity to the Bhutanese concept of Gross national happiness, in that it attempts to value quality of life in a way that goes beyond traditional economic indicators.
The term was coined in November 2013 by Singapore President Dr Tony Tan at an event organised by St. Joseph's Institution, Singapore. Speaking in a lecture series on leadership, President Tan said:
”The social reserves of a nation are the intangible ties that bind us to one another, and make a nation greater than the sum of individual citizens. [They] are the goodwill that makes us look out for one another even during difficult times, the resilience to overcome challenges and constraints, and the tenacity to progress as individuals and as a nation.”
Singapore maintains large financial reserves, primarily through two sovereign wealth funds. The Government of Singapore Investment Corporation (GIC) manages Singapore's foreign reserves; Temasek Holdings is an investment company owned by the Government of Singapore. Prior to running for Singapore's elected presidency, President Tony Tan was executive director of GIC.
An example of an effort to build up social reserves, he said, was the way that he had expanded Singapore's President's Challenge charity event to go beyond fund-raising to promote volunteerism and social entrepreneurship. |
https://en.wikipedia.org/wiki/Constance%20Cochnower%20Virtue | Constance Cochnower Virtue (6 January 1905 – 21 February 1992) was an American composer and organist who developed a musical notation system called the Virtue Notagraph.
Life and career
Virtue was born in Cincinnati, Ohio, to Robert and Edith Rankin Cochnower. She married Navy doctor Clark W. Virtue and they had two children, Christie and Robert.
Virtue received a B.M. from the University of Cincinnati in 1927, and a master's degree in sacred music from the Union Theological Seminary in New York in 1945. She gave private piano and organ lessons and taught at Grossmont College from 1961 to 1963. She also served as the organist/music director at several churches in New York and California. In 1968, she toured as the pianist with an opera program for Alaska Music Trails.
Virtue developed the Notagraph, which has a seven-line staff, in 1933 as a new system of musical notation. She trademarked the Notagraph and published two books about it: Design for a Modern Notation (1945) and Music without Accidents (1975).
Virtue was a member of Mu Phi Epsilon and the American Guild of Organists. Her papers are archived at the University of California San Diego Center for Research in Computing and the Arts. Her music was published by H.W. Gray and G. Schirmer, Inc.
Works
Virtue's compositions include:
Chamber
Fairy Tale for a Sleepy Child (cello)
For Spring Returning (violin)
Romanza (violin, cello and piano)
String Quartet in G
Orchestra
Mystic Sonnet: To a Tree in Bloom (also arranged for piano)
Theater
Queen of Camelot (musical)
What Gift to the King? (Christmas music drama)
Vocal
"Farragut March Song"
"I Will Lift Up Mine Eyes"
"Love is Like a Rose" (text by Christina Georgina Rossetti)
Six Songs from the Chronology of Love |
https://en.wikipedia.org/wiki/Fin%20%28extended%20surface%29 | In the study of heat transfer, fins are surfaces that extend from an object to increase the rate of heat transfer to or from the environment by increasing convection. The amount of conduction, convection, or radiation of an object determines the amount of heat it transfers. Increasing the temperature gradient between the object and the environment, increasing the convection heat transfer coefficient, or increasing the surface area of the object increases the heat transfer. Sometimes it is not feasible or economical to change the first two options. Thus, adding a fin to an object, increases the surface area and can sometimes be an economical solution to heat transfer problems.
One-piece finned heat sinks are produced by extrusion, casting, skiving, or milling.
General case
To create a tractable equation for the heat transfer of a fin, many assumptions need to be made:
Steady state
Constant material properties (independent of temperature)
No internal heat generation
One-dimensional conduction
Uniform cross-sectional area
Uniform convection across the surface area
With these assumptions, conservation of energy can be used to create an energy balance for a differential cross section of the fin:
Fourier’s law states that
where is the cross-sectional area of the differential element. Furthermore, the convective heat flux can be determined via the definition of the heat transfer coefficient h,
where is the temperature of the surroundings. The differential convective heat flux can then be determined from the perimeter of the fin cross-section P,
The equation of energy conservation can now be expressed in terms of temperature,
Rearranging this equation and using the definition of the derivative yields the following differential equation for temperature,
;
the derivative on the left can be expanded to the most general form of the fin equation,
The cross-sectional area, perimeter, and temperature can all be functions of x.
Uniform cross-sectional area
If the |
https://en.wikipedia.org/wiki/Smart%20cut | Smart cut is a technological process that enables the transfer of very fine layers of crystalline silicon material onto a mechanical support. It was invented by Michel Bruel of CEA-Leti, and was protected by US patent 5374564. The application of this technological procedure is mainly in the production of silicon-on-insulator (SOI) wafer substrates.
The role of SOI is to electronically insulate a fine layer of monocrystalline silicon from the rest of the silicon wafer; an ultra-thin silicon film is transferred to a mechanical support, thereby introducing an intermediate, insulating layer. Semiconductor manufacturers can then fabricate integrated circuits on the top layer of the SOI wafers using the same processes they would use on plain silicon wafers.
The sequence of illustrations pictorially describes the process involved in fabricating SOI wafers using the smart cut technology. |
https://en.wikipedia.org/wiki/DF-224 | The DF-224 is a space-qualified computer used in space missions from the 1980s. It was built by Rockwell Autonetics. As with many spacecraft computers, the design is very redundant, since servicing in space is at best difficult and often impossible. The configuration had three CPUs, one active and two spares. The main memory consisted of six memory units, each with 8K 24-bit words of plated wire memory, with up to 48K words total. Four memory modules could be powered up at one time, resulting in a maximum of 32K words of available memory, though some applications such as the Hubble Space Telescope used fewer memory banks to allow for graceful failure modes. There were three I/O processors, one operational and two backups. The power supply consisted of 6 independent power converters, with overlapping coverage of the operating functions. The processor used fixed-point arithmetic with a two's complement format.
Compared to computers that came later, the DF-224 was big and slow. It was roughly by by , weighed , and had a clock speed of 1.25 MHz.
The DF-224 on HST was augmented with a 386 co-processor on the first servicing mission (SM1). This had a clock speed of 16 MHz.
In Hubble servicing mission 3A the DF-224 (with co-processor) was replaced by the Advanced Computer using a 25 MHz Intel i486, and much more storage
The DF-224 was one of the candidate computers for the Space Shuttle, but was not selected. It was also baselined in a version of a reusable Agena upper stage for use with the Shuttle, but this was never built.
See also
IBM RAD6000 - a more modern space-qualified computer.
RAD750 - newer version
Mongoose-V - radiation hard processor based on the MIPS-3000.
Various implementations of the MIL-STD-1750A 16-bit processor have been used in several spacecraft |
https://en.wikipedia.org/wiki/Priority%20encoder | A priority encoder is a circuit or algorithm that compresses multiple binary inputs into a smaller number of outputs, similar to a simple encoder. The output of a priority encoder is the binary representation of the index of the most significant activated line. In contrast to the simple encoder, if two or more inputs to the priority encoder are active at the same time, the input having the highest priority will take precedence. It is an improvement on a simple encoder because it can handle all possible input combinations, but at the cost of extra logic.
Applications of priority encoders include their use in interrupt controllers (to allow some interrupt requests to have higher priority than others), decimal or binary encoding, and analog-to-digital / digital to-analog conversion.
A truth table of a single bit 4-to-2 priority encoder is shown, where the inputs are shown in decreasing order of priority left-to-right, and "x" indicates a don't care term - i.e. any input value there yields the same output since it is superseded by a higher-priority input. The (usually-included) "v" output indicates if the input is valid.
Priority encoders can be easily connected in arrays to make larger encoders, such as one 16-to-4 encoder made from six 4-to-2 priority encoders – four 4-to-2 encoders having the signal source connected to their inputs, and the two remaining encoders take the output of the first four as input.
Recursive construction of priority encoders
A priority-encoder, also called leading zero detector (LZD) or leading zero counter (LZC), receives an -bit input vector and detects the index of the first binary ‘1’ in the input vector. A valid signal indicates if any binary ‘1’ was detected in the input vector, hence the index is valid.
Priority-encoders can be efficiently constructed by recursion. The input vector is split into equal fragments with bits. A priority encoder with a narrower width of 𝑛/𝑘 is applied for each fragment. The valid bit of each of the |
https://en.wikipedia.org/wiki/Book%20of%20the%20Zodiac | The Book of the Zodiac () is a Mandaean text. It covers Mandaean astrology in great detail. The book is used to obtain a Mandaean's baptismal name (malwasha). It is also an important source on Mandaean numerology.
Manuscripts and translations
An English translation of the text, based on Manuscript 31 of the Drower Collection (DC 31), was published by E. S. Drower in 1949. The manuscript is a kurasa, or unbound manuscript consisting of loose sheets.
Buckley has also located a privately held copy of the Book of the Zodiac dating from 1919, which belonged to Lamea Abbas Amara in San Diego.
There is also a manuscript of the Book of the Zodiac from 1789 CE that is currently held at the Bibliothèque National in Paris, which was used by Drower and may have also been used by Nicolas Siouffi.
Contents
Drower's manuscript (DC 31) consists of 289 pages in Mandaic. There are 20 individual books or sections, which are:
Book 1: The Book of the Signs of the Zodiac for Men
Book 2: The Book of the Signs of the Zodiac for Women
Book 3: The Book of Stars
Book 4: lists of astrological terms and calculations
Book 5: The Book of the Moon
Book 6: charms against evil spirits
Book 7: charms against evil spirits
Book 8: The Days of the Month
Book 9: illnesses
Book 10: astrological information
Book 11: selecting days for certain activities
Book 12: The Opening of a Door
Book 13: predictions
Book 14: predictions
Book 15: predictions
Book 16: predictions
Book 17: geographical regions governed by the planets and zodiac signs
Book 18: predictions
Book 19: transits of Saturn, halos of the sun, meteors and comets, and rainfall
Book 20: meteorology
There is also an appendix (labeled as Part II in Drower's text) that discusses omens, predictions, remedies, eclipses, and other topics.
See also
Ginza Rabba
Mandaean Book of John |
https://en.wikipedia.org/wiki/Verhoeff%20algorithm | The Verhoeff algorithm is a checksum for error detection first published by Dutch mathematician Jacobus Verhoeff in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two adjacent digits, which was at the time thought impossible with such a code.
The method was independently discovered by H. Peter Gumm in 1985, this time including a formal proof and an extension to any base.
Goals
Verhoeff had the goal of finding a decimal code—one where the check digit is a single decimal digit—which detected all single-digit errors and all transpositions of adjacent digits. At the time, supposed proofs of the nonexistence of these codes made base-11 codes popular, for example in the ISBN check digit.
His goals were also practical, and he based the evaluation of different codes on live data from the Dutch postal system, using a weighted points system for different kinds of error. The analysis broke the errors down into a number of categories: first, by how many digits are in error; for those with two digits in error, there are transpositions (ab → ba), twins (aa → 'bb'), jump transpositions (abc → cba), phonetic (1a → a0), and jump twins (aba → cbc). Additionally there are omitted and added digits. Although the frequencies of some of these kinds of errors might be small, some codes might be immune to them in addition to the primary goals of detecting all singles and transpositions.
The phonetic errors in particular showed linguistic effects, because in Dutch, numbers are typically read in pairs; and also while 50 sounds similar to 15 in Dutch, 80 doesn't sound like 18.
Taking six-digit numbers as an example, Verhoeff reported the following classification of the errors:.
Description
The general idea of the algorithm is to represent each of the digits (0 through 9) as elements of the dihedral group . That is, map digits to , manipulate these, then map back into digits. Let this mapping be
Let |
https://en.wikipedia.org/wiki/DECnet | DECnet is a suite of network protocols created by Digital Equipment Corporation. Originally released in 1975 in order to connect two PDP-11 minicomputers, it evolved into one of the first peer-to-peer network architectures, thus transforming DEC into a networking powerhouse in the 1980s. Initially built with three layers, it later (1982) evolved into a seven-layer OSI-compliant networking protocol.
DECnet was built right into the DEC flagship operating system OpenVMS since its inception. Later Digital ported it to Ultrix, OSF/1 (later Tru64) as well as Apple Macintosh and IBM PC running variants of DOS, OS/2 and Microsoft Windows under the name PATHWORKS, allowing these systems to connect to DECnet networks of VAX machines as terminal nodes.
While the DECnet protocols were designed entirely by Digital Equipment Corporation, DECnet Phase II (and later) were open standards with published specifications, and several implementations were developed outside DEC, including ones for FreeBSD and Linux. DECnet code in the Linux kernel was marked as orphaned on February 18, 2010 and removed August 22, 2022.
Evolution
DECnet refers to a specific set of hardware and software networking products which implement the DIGITAL Network Architecture (DNA). The DIGITAL Network Architecture has a set of documents which define the network architecture in general, state the specifications for each layer of the architecture, and describe the protocols which operate within each layer. Although network protocol analyzer tools tend to categorize all protocols from DIGITAL as "DECnet", strictly speaking, non-routed DIGITAL protocols such as LAT, SCS, AMDS, LAST/LAD are not DECnet protocols and are not part of the DIGITAL Network Architecture.
To trace the evolution of DECnet is to trace the development of DNA. The beginnings of DNA were in the early 1970s. DIGITAL published its first DNA specification at about the same time that IBM announced its Systems Network Architecture (SNA). Since |
https://en.wikipedia.org/wiki/LANtastic | LANtastic is a peer-to-peer local area network (LAN) operating system for DOS and Microsoft Windows (and formerly OS/2). The New York Times described the network, which permits machines to function both as servers and as workstations, as allowing computers, "to share printers and other devices."
InformationWeek pointed out that "these peer-to-peer networking solutions, such as Webcorp's Web and Artisoft's LANtastic, definitely aren't powerful, but they can act as 'starter' local area networks" yet added that even Fortune-sized companies find them useful.
LANtastic supports Ethernet, ARCNET and Token Ring adapters as well as its original twisted-pair adapter at .
Overview
Lantastic networks use NetBIOS.
Its multi-platform support allows a LANtastic client station to access any combination of Windows or DOS operating systems, and its interconnectivity allows sharing of files, printers, CD-ROMs and applications throughout an enterprise. LANtastic was especially popular before Windows 95 arrived with built-in networking and was nearly as popular as the market leader Novell at the time.
The New York Times described the network, which permits machines to function both as servers and as workstations, as allowing computers "to share printers and other devices.
History
LANtastic was originally developed by Artisoft, Inc. in Tucson, Arizona, the first company to offer peer-to-peer networking.
Several foreign-language versions were released in 1992.
By mid 1994, Microsoft's Windows for Workgroups was "eating into" LANtastic's lead (as was Novell).
Artisoft bought TeleVantage, and renamed the latter Artisoft TeleVantage. Artisoft subsequently bought Vertical Communications (September, 2004), and renamed itself (January, 2005) to be Vertical Communications.
Following the release of TeleVantage, Lantastic and Artisoft's other legacy products were acquired by SpartaCom Technologies in 2000. SpartaCom was later acquired by PC Micro.
LANtastic 8.01 was released in 2006. |
https://en.wikipedia.org/wiki/Dynamic%20bandwidth%20allocation | Dynamic bandwidth allocation is a technique by which traffic bandwidth in a shared telecommunications medium can be allocated on demand and fairly between different users of that bandwidth. This is a form of bandwidth management, and is essentially the same thing as statistical multiplexing. Where the sharing of a link adapts in some way to the instantaneous traffic demands of the nodes connected to the link.
Dynamic bandwidth allocation takes advantage of several attributes of shared networks:
all users are typically not connected to the network at one time
even when connected, users are not transmitting data (or voice or video) at all times
most traffic occurs in bursts—there are gaps between packets of information that can be filled with other user traffic
Different network protocols implement dynamic bandwidth allocation in different ways. These methods are typically defined in standards developed by standards bodies such as the ITU, IEEE, FSAN, or IETF. One example is defined in the ITU G.983 specification for passive optical network (PON).
See also
Statistical multiplexing
Channel access method
Dynamic channel allocation
Reservation ALOHA (R-ALOHA)
Telecommunications techniques
Computer networking
Radio resource management |
https://en.wikipedia.org/wiki/Dagobert%20Karl%20de%20Daldorff | Dagobert Carl (also Charles/Karl) von Daldorff (wrongly given in some places as Ingobert Karl Daldorff) (c. 1760 – 18 December 1802) was a senior lieutenant in the Danish East India Company, naturalist and collector of natural history specimens. He is commemorated in the crab genus Daldorfia.
Daldorff was born in Kiel (although some sources claimed that he was born in Moscow) and obtained a doctorate from the University of Kiel in 1795 under J.C. Fabricius. He joined the Danish East India Company army serving as a lieutenant captain. He was sent to conduct natural history studies, supported by Count Schimmelmann, to the Danish colonies of Frederiksnagore where he became a member of the council. He also travelled to the Danish colony of Tranquebar in India. During his travels to India and on his stays he collected insects, crustaceans, birds, and fishes. He maintained a diary of his travels from Copenhagen, leaving on October 14, 1790 and reaching Tranquebar on May 6, 1791, and an excerpt was published by the Danish East India Company. He served as a Second lieutenant at the Garrison in 1792 and Governor Peter Anker recorded that he was excellent in mathematics. While in Tranquebar, he worked on a monograph of the crabs which was never published. In 1795 he went to Sumatra (where he made an ascent of Gunung Bungkuk) and returned to Serampore. In 1798 he clashed with Colonel Bie and resigned from military service in 1799 but continued to stay member of the council. He died at Serampore in 1802. A debt of 665 Danish rigsdaler was paid by Ove R. Sehested who along with Tønder Lund obtained a number of his insect specimens. Some of the insects he collected were examined and a few (such as the dragonfly Tholymis tillarga) described by Fabricius. Several birds were described by Martin Vahl. The crab genus Daldorfia was named for him by Mary J. Rathbun in 1904. His note on the climbing perch Perca scandens to Joseph Banks was read in the Linnean Society in 1795. He noted |
https://en.wikipedia.org/wiki/Nete%20virus | Nete virus is a lineage of segmented RNA viruses infecting animals which was discovered in 2020. |
https://en.wikipedia.org/wiki/Actinide%20concept | In nuclear chemistry, the actinide concept (also known as actinide hypothesis) proposed that the actinides form a second inner transition series homologous to the lanthanides. Its origins stem from observation of lanthanide-like properties in transuranic elements in contrast to the distinct complex chemistry of previously known actinides. Glenn Theodore Seaborg, one of the researchers who synthesized transuranic elements, proposed the actinide concept in 1944 as an explanation for observed deviations and a hypothesis to guide future experiments. It was accepted shortly thereafter, resulting in the placement of a new actinide series comprising elements 89 (actinium) to 103 (lawrencium) below the lanthanides in Dmitri Mendeleev's periodic table of the elements.
Origin
In the late 1930s, the first four actinides (actinium, thorium, protactinium, and uranium) were known. They were believed to form a fourth series of transition metals, characterized by the filling of 6d orbitals, in which thorium, protactinium, and uranium were respective homologs of hafnium, tantalum, and tungsten. This view was widely accepted as chemical investigations of these elements revealed various high oxidation states and characteristics that closely resembled the 5d transition metals. Nevertheless, research into quantum theory by Niels Bohr and subsequent publications proposed that these elements should constitute a 5f series analogous to the lanthanides, with calculations that the first 5f electron should appear in the range from atomic number 90 (thorium) to 99 (einsteinium). Inconsistencies between theoretical models and known chemical properties thus made it difficult to place these elements in the periodic table.
The first appearance of the actinide concept may have been in a 32-column periodic table constructed by Alfred Werner in 1905. Upon determining the arrangement of the lanthanides in the periodic table, he placed thorium as a heavier homolog of cerium, and left spaces for hypot |
https://en.wikipedia.org/wiki/Xylitol | Xylitol is a chemical compound with the formula , or HO(CH2)(CHOH)3(CH2)OH; specifically, one particular stereoisomer with that structural formula. It is a colorless or white crystalline solid that is freely soluble in water. It can be classified as a polyalcohol and a sugar alcohol, specifically an alditol. The name derives from , xyl[on] 'wood', with the suffix -itol used to denote sugar alcohols.
Xylitol is used as a food additive and sugar substitute. Its European Union code number is E967. Replacing sugar with xylitol in food products may promote better dental health, but evidence is lacking on whether xylitol itself prevents dental cavities.
History
Emil Fischer, a German chemistry professor, and his assistant Rudolf Stahel isolated a new compound from beech wood chips in September 1890 and named it Xylit, the German word for xylitol. The following year, the French chemist M.G. Bertrand isolated xylitol syrup by processing wheat and oat straw. Sugar rationing during World War II led to an interest in sugar substitutes. Interest in xylitol and other polyols became intense, leading to their characterization and manufacturing methods.
Structure, production, commerce
Xylitol is one of three 5-carbon sugar alcohols. The others are arabitol and ribitol. These three compounds differ in the stereochemistry of the three secondary alcohol groups.
Xylitol occurs naturally in small amounts in plums, strawberries, cauliflower, and pumpkin; humans and many other animals make trace amounts during metabolism of carbohydrates. Unlike most sugar alcohols, xylitol is achiral. Most other isomers of pentane-1,2,3,4,5-pentol are chiral, but xylitol has a plane of symmetry.
Industrial production starts with lignocellulosic biomass from which xylan is extracted; raw biomass materials include hardwoods, softwoods, and agricultural waste from processing maize, wheat, or rice. The mixture is hydrolyzed with acid to give xylose. The xylose is purified by chromatography. Purifi |
https://en.wikipedia.org/wiki/Scroll%20%28art%29 | The scroll in art is an element of ornament and graphic design featuring spirals and rolling incomplete circle motifs, some of which resemble the edge-on view of a book or document in scroll form, though many types are plant-scrolls, which loosely represent plant forms such as vines, with leaves or flowers attached. Scrollwork is a term for some forms of decoration dominated by spiralling scrolls, today used in popular language for two-dimensional decorative flourishes and arabesques of all kinds, especially those with circular or spiralling shapes.
Scroll decoration has been used for the decoration of a vast range of objects, in all Eurasian cultures, and most beyond. A lengthy evolution over the last two millennia has taken forms of plant-based scroll decoration from Greco-Roman architecture to Chinese pottery, and then back across Eurasia to Europe. They are very widespread in architectural decoration, woodcarving, painted ceramics, mosaic, and illuminated manuscripts (mostly for borders).
In the usual artistic convention, scrolls "apparently do not succumb to gravitational forces, as garlands and festoons do, or oppose them, in the manner of vertically growing trees. This gives scrolls a relentless power. Even if attached to walls, they are more deeply embedded in the architectural order than the festoon, which are fictitiously hanging on them."
Terminology
Typically in true scrolls the main "stem" lines do not cross over each other, or not significantly. When crossing stems become a dominant feature in the design, terms such as interlace or arabesque are used instead. Many scrolls run along a relatively narrow band, such as a frieze panel or the border of a carpet or piece of textile or ceramics, and so are often called "running scrolls", while others spread to cover wide areas, and are often infinitely expandible. Similar motifs made up of straight lines and right angles, such as the "Greek key", are more often called meanders.
In art history, a "flo |
https://en.wikipedia.org/wiki/Mixed-signal%20integrated%20circuit | A mixed-signal integrated circuit is any integrated circuit that has both analog circuits and digital circuits on a single semiconductor die. Their usage has grown dramatically with the increased use of cell phones, telecommunications, portable electronics, and automobiles with electronics and digital sensors.
Overview
Integrated circuits (ICs) are generally classified as digital (e.g. a microprocessor) or analog (e.g. an operational amplifier). Mixed-signal ICs contain both digital and analog circuitry on the same chip, and sometimes embedded software. Mixed-signal ICs process both analog and digital signals together. For example, an analog-to-digital converter (ADC) is a typical mixed-signal circuit.
Mixed-signal ICs are often used to convert analog signals to digital signals so that digital devices can process them. For example, mixed-signal ICs are essential components for FM tuners in digital products such as media players, which have digital amplifiers. Any analog signal can be digitized using a very basic ADC, and the smallest and most energy efficient of these are mixed-signal ICs.
Mixed-signal ICs are more difficult to design and manufacture than analog-only or digital-only integrated circuits. For example, an efficient mixed-signal IC may have its digital and analog components share a common power supply. However, analog and digital components have very different power needs and consumption characteristics, which makes this a non-trivial goal in chip design.
Mixed-signal functionality involves both traditional active elements (like transistors) and well-performing passive elements (like coils, capacitors, and resistors) on the same chip. This requires additional modelling understanding and options from manufacturing technologies. High voltage transistors might be needed in the power management functions on a chip with digital functionality, possibly with a low-power CMOS processor system. Some advanced mixed-signal technologies may enable combining an |
https://en.wikipedia.org/wiki/Fluorophore-assisted%20carbohydrate%20electrophoresis | Fluorophore assisted carbohydrate electrophoresis or FACE is a biochemical technology suited for detecting complex mixtures of high molecular weight N-glycans. A specialized form of this technique is the DSA-FACE, which is an acronym for DNA sequencer-assisted flurophore-assisted carbohydrate electrophoresis. DSA-FACE has higher resolution and sensitivity than classical FACE. |
https://en.wikipedia.org/wiki/Olivary%20body | In anatomy, the olivary bodies or simply olives (Latin oliva and olivae, singular and plural, respectively) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. They contain the olivary nuclei.
Structure
The olivary body is located on the anterior surface of the medulla lateral to the pyramid, from which it is separated by the antero-lateral sulcus and the fibers of the hypoglossal nerve.
Behind (dorsally), it is separated from the postero-lateral sulcus by the ventral spinocerebellar fasciculus. In the depression between the upper end of the olive and the pons lies the vestibulocochlear nerve.
In humans, it measures about 1.25 cm in length, and between its upper end and the pons there is a slight depression to which the roots of the facial nerve are attached.
The external arcuate fibers wind across the lower part of the pyramid and olive and enter the inferior peduncle.
Olivary nuclei
The olive consists of two parts:
The inferior olivary nucleus (or 'complex'), which is a part of the olivo-cerebellar system and is mainly involved in cerebellar motor-learning and function.
The superior olivary nucleus, considered part of the pons and part of the auditory system, aiding the perception of sound.
The inferior olive in itself is divided to 3 main nuclei:
The primary olivary nucleus (PO) which consist of the major laminar structure.
The medial accessory olivary nucleus (MAO) lies between the primary olivary nucleus and the pyramid, and forms a curved lamina, the concavity of which is directed laterally.
The dorsal accessory olivary nucleus (DAO) is the smallest, and appears on transverse section as a curved lamina behind the primary olivary nucleus.
Small additional inferior olivary structures consist of the dorsal cap of Kooy and the ventrolateral outgrowth.
Additional images |
https://en.wikipedia.org/wiki/Home%20Gateway%20Initiative | The Home Gateway Initiative (HGI) was a nonprofit trade organization to discuss the key specifications and standards of residential gateways, also known as home gateways.
It was founded by telephone companies (Belgacom, BT, Deutsche Telekom, France Telecom, KPN, Nippon Telegraph and Telephone (NTT), Swiss Telecom, Telenor, Telecom Italia and Teliasonera) in December 2004.
Several manufacturers such as ADB, Devolo, Huawei, Ikanos Communications, Intel, Lantiq, SoftAtHome or ZTE also joined the alliance.
HGI's aims included:
Release specifications of the home gateway.
Boost the market of home communication services to the millions of customers served by its founding members.
Improve the interoperability of gateways with home devices.
HGI also built on work of other standards bodies such as the Broadband Forum, Digital Living Network Alliance (DLNA) and Open Services Gateway initiative (OSGi) Alliance.
The initiative made an agreement with the Telecommunication Standardization Sector of the International Telecommunication Union (ITU-T) in 2006. HGI established relations with oneM2M and initiated a transfer of HGI work into oneM2M, especially regarding a Smart Device Template (SDT) specification which was transferred as ETSI TR 118 522 V2.0.0 (2016-09)
HGI closed operations in June 2016, wrapping up according to its statutes, and archiving all specifications for five years. The HGI website and documents were permanently archived on www.archive.org on 21 February 2021. The organisation webpage www.homegatewayinitiative.org is no longer owned and might potentially be taken over by some other organisation in future. |
https://en.wikipedia.org/wiki/Nanocrystal%20solar%20cell | Nanocrystal solar cells are solar cells based on a substrate with a coating of nanocrystals. The nanocrystals are typically based on silicon, CdTe or CIGS and the substrates are generally silicon or various organic conductors. Quantum dot solar cells are a variant of this approach which take advantage of quantum mechanical effects to extract further performance. Dye-sensitized solar cells are another related approach, but in this case the nano-structuring is a part of the substrate.
Previous fabrication methods relied on expensive molecular beam epitaxy processes, but colloidal synthesis allows for cheaper manufacturing. A thin film of nanocrystals is obtained by a process known as "spin-coating". This involves placing an amount of the quantum dot solution onto a flat substrate, which is then rotated very quickly. The solution spreads out uniformly, and the substrate is spun until the required thickness is achieved.
Quantum dot based photovoltaic cells based on dye-sensitized colloidal TiO2 films were investigated in 1991
and were found to exhibit promising efficiency of converting incident light energy to electrical energy, and to be incredibly encouraging due to the low cost of materials used. A single-nanocrystal (channel) architecture in which an array of single particles between the electrodes, each separated by ~1 exciton diffusion length, was proposed to improve the device efficiency and research on this type of solar cell is being conducted by groups at Stanford, Berkeley and the University of Tokyo.
Although research is still in its infancy, nanocrystal photovoltaics may offer advantages such as flexibility (quantum dot-polymer composite photovoltaics)
lower costs, clean power generation and an efficiency of 65%, compared to around 20 to 25% for first-generation, crystalline silicon-based photovoltaics in the future.
It is argued that many measurements of the efficiency of the nanocrystal solar cell are incorrect and that nanocrystal solar cells are not |
https://en.wikipedia.org/wiki/Cinemeccanica | Cinemeccanica is a motion picture equipment company specializing in cinema projectors. The company was formed in 1920 in Milan, Italy. Currently they have two film projectors available, the Victoria 5 (introduced in 1975) and the Victoria 8 (introduced in 1961). A new digital projector, the CMC3 D2 is also available.
The Victoria 8 at one time came in two models, a 35 mm film gauge and a dual 35/70 mm film gauge. The projector has become less popular in recent years with the smaller and cheaper Victoria 5 now the best selling projector from Cinemeccanica.
The company also manufacture film platter systems (the CNR-35N), film rewinders and Dolby Digital and SR soundtrack readers.
See also
List of Italian Companies
External links
Cinemeccanica
Pico Projector Comparison
Answers Article About Cinemeccanica
Youtube video of a Victoria 5 Projector
Electronics companies of Italy
Manufacturing companies based in Milan
Manufacturing companies established in 1920
1920 establishments in Italy
Italian brands
Projectors |
https://en.wikipedia.org/wiki/Admission%20note | An admission note is part of a medical record that documents the patient's status (including history and physical examination findings), reasons why the patient is being admitted for inpatient care to a hospital or other facility, and the initial instructions for that patient's care.
Purpose
Admission notes document the reasons why a patient is being admitted for inpatient care to a hospital or other facility, the patient's baseline status, and the initial instructions for that patient's care. Health care professionals use them to record a patient's baseline status and may write additional on-service notes, progress notes (SOAP notes), preoperative notes, operative notes, postoperative notes, procedure notes, delivery notes, postpartum notes, and discharge notes. These notes constitute a large part of the medical record. Medical students often develop their clinical reasoning skills by writing admission notes. The traditional, rational definition of being admitted usually involves spending an overnight in the hospital. This definition is sometimes stretched in the U.S. medical billing industry, where hospital corporations may blur the definitions of "admission" and "observation" because of reimbursement rules under which healthcare payors pay less for the care if an "admission" was involved.
Components
An admission note may sometimes be incorrectly referred to as an HPI (history of present illness) or H and P (history and physical), which include only portions of an admission note.
An admission note can include the following sections:
Outline
Not every admission note explicitly discusses every item listed below, however, the ideal admission note would include:
Header
Patient identifying information (maybe located separately)
name
ID number
chart number
room number
date of birth
attending physician
sex
admission date
Date
Time
Service
Chief complaint (CC)
Typically one sentence including
age
race
sex
presenting complaint
example: "34 yo whi |
https://en.wikipedia.org/wiki/Water%20Resistant%20mark | Water Resistant is a common mark stamped on the back of wrist watches to indicate how well a watch is sealed against the ingress of water. It is usually accompanied by an indication of the static test pressure that a sample of newly manufactured watches were exposed to in a leakage test. The test pressure can be indicated either directly in units of pressure such as bar, atmospheres, or (more commonly) as an equivalent water depth in metres (in the United States sometimes also in feet).
An indication of the test pressure in terms of water depth does not mean a water-resistant watch was designed for repeated long-term use in such water depths. For example, a watch marked 30 metres water resistant cannot be expected to withstand activity for longer time periods in a swimming pool, let alone continue to function at 30 metres under water. This is because the test is conducted only once using static pressure on a sample of newly manufactured watches. As only a small sample is tested, there is a small likelihood that any individual watch is not water resistant to the certified depth or even at all.
The test for qualifying a diving watch to bear the word "diver's" on the dial is for repeated usage in a given depth and includes safety margins to take factors into account like aging of the seals, the properties of water and seawater, rapidly changing water pressure and temperature, as well as dynamic mechanical stresses encountered by a watch. Every "diver's" badged watch has to be taken through a small but highly specified battery of tests designed to simulate those stresses including being tested for continued water resistance up to 125% of the stated rating (a "200 meter" watch has to be pressured up to 250 meters water depth equivalent and show no signs of intrusion).
ISO 2281 water-resistant watches standard
The International Organization for Standardization (ISO) issued a standard for water-resistant watches which also prohibits the term waterproof to be used with w |
https://en.wikipedia.org/wiki/Balto%20%28film%29 | Balto is a 1995 animated adventure film directed by Simon Wells, produced by Amblin Entertainment and distributed by Universal Pictures. The film, which stars the voices of Kevin Bacon, Bridget Fonda, Jim Cummings, Phil Collins and Bob Hoskins, is loosely based on the true story of the eponymous dog who helped save children infected with diphtheria in the 1925 serum run to Nome. Though primarily an animated film, it uses a live-action framing device that takes place in New York City's Central Park and features Miriam Margolyes.
Although the film was a major financial disappointment (it was overshadowed by the success of Pixar's Toy Story), its subsequent sales on home video led to two direct-to-video sequels: Balto II: Wolf Quest (2002) and Balto III: Wings of Change (2005), though none of the original voice cast reprised their roles.
Plot
In New York City, an elderly woman and her granddaughter are walking through Central Park, looking for a memorial statue. As they seat themselves for a rest, the grandmother recounts a story about Nome, Alaska.
In 1925, Balto, a wolfdog hybrid, lives in an abandoned boat on the outskirts of Nome with his adoptive father, a Russian snow goose named Boris, and two polar bears, Muk and Luk. Being a half-breed, Balto is ridiculed by dogs and humans alike. His only friends in town are a little girl named Rosy, and her red husky, Jenna whom Balto has a crush on, and is challenged by the town's favorite sled dog, Steele, a fierce and arrogant Alaskan Malamute.
That night, all the children, including Rosy, fall ill with diphtheria. Severe winter weather conditions prevent medicine from being brought by air or sea from Anchorage, and the closest rail line ends in Nenana after authorization to transport the antitoxin by rail is given by the Governor of Alaska in Juneau. A dog race is held to determine the best-fit dogs for a sled dog team to get the medicine. Balto enters and wins, but Steele exposes his wolf-dog heritage, resulting i |
https://en.wikipedia.org/wiki/Citranaxanthin | Citranaxanthin is a carotenoid pigment used as a food additive under the E number E161i as a food coloring. There are natural sources of citranaxanthin, but it is generally prepared synthetically. It is used as an animal feed additive to impart a yellow color to chicken fat and egg yolks. |
https://en.wikipedia.org/wiki/Soci%C3%A9t%C3%A9%20mycologique%20de%20France | The Société mycologique de France (Mycological Society of France), often known by the abbreviation SMF, is an association linking French and French-speaking mycologists.
History
The society was founded in 1884 in Épinal in the Vosges by three doctors,
Lucien Quélet (1832-1889), Antoine Mougeot (1815-1889) and René Joseph Justin Ferry (1845-1924), joined by two pharmacists, Émile Boudier (1828-1920) and Narcisse Théophile Patouillard (1854-1926).
The object of the society was to "Establish relationships between mycologists scattered in various parts of French territory, centralize their research and thereby achieve the foundation of a complete fungal flora of France".
It was the first mycological society in the world. One year after its creation it already had 128 members and three years later it had 250. Most founder members were pharmacists, doctors or teachers and then it opened to amateurs.
The society's headquarters are located at 20 rue Rottembourg in the 12th arrondissement of Paris.
Activities
The society provides many activities and facilities for its members including
Forest excursions hunting fungi accompanied by mycologists
Identification sessions of collected fungi
An annual exhibition of fresh mushrooms in Paris (in 2006 this was held from 11 to 15 October in the pavilion 18 of the Parc floral de Paris).
An annual congress held in the French provinces (in 2006, this was held in Herbeumont (Belgium) from 25 to 30 September. In 2007, in Poitiers. In 2008 in Dourdan).
Courses in mycology and microscopy for beginners.
Access to its publications including the SMF database
Publications
The society publishes a newsletter, an academic journal (the Bulletin de la Société Mycologique de France), a list of recommended French names of fungi and a database.
The SMF database
The SMF database ("") operates under Access and contains more than 16,000 species of fungi studied by mycologists for their botanical interest, notably those of particular intere |
https://en.wikipedia.org/wiki/Open%20architecture | Open architecture is a type of computer architecture or software architecture intended to make adding, upgrading, and swapping components with other computers easy. For example, the IBM PC, Amiga 500 and Apple IIe have an open architecture supporting plug-in cards, whereas the Apple IIc computer has a closed architecture. Open architecture systems may use a standardized system bus such as S-100, PCI or ISA or they may incorporate a proprietary bus standard such as that used on the Apple II, with up to a dozen slots that allow multiple hardware manufacturers to produce add-ons, and for the user to freely install them. By contrast, closed architectures, if they are expandable at all, have one or two "expansion ports" using a proprietary connector design that may require a license fee from the manufacturer, or enhancements may only be installable by technicians with specialized tools or training.
Computer platforms may include systems with both open and closed architectures. The Mac mini and Compact Macintosh are closed; the Macintosh II and Power Mac G5 are open. Most desktop PCs are open architecture.
Similarly, an open software architecture is one in which additional software modules can be added to the basic framework provided by the architecture. Open APIs (Application Programming Interfaces) to major software products are the way in which the basic functionality of such products can be modified or extended. The Google APIs are examples. A second type of open software architecture consists of the messages that can flow between computer systems. These messages have a standard structure that can be modified or extended per agreements between the computer systems. An example is IBM's Distributed Data Management Architecture.
Open architecture allows potential users to see inside all or parts of the architecture without any proprietary constraints. Typically, an open architecture publishes all or parts of its architecture that the developer or integrator wants to |
https://en.wikipedia.org/wiki/NDUFB1 | NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 1 is an enzyme that in humans is encoded by the NDUFB1 gene. NADH dehydrogenase (ubiquinone) 1 beta subcomplex, 1, 7kDa is an accessory subunit of the NADH dehydrogenase (ubiquinone) complex, located in the mitochondrial inner membrane. It is also known as Complex I and is the largest of the five complexes of the electron transport chain.
Structure
The NDUFB1 gene, located on the q arm of chromosome 14 in position 32.12, is 5,687 base pairs long. The NDUFB1 protein weighs 7 kDa and is composed of 58 amino acids. NDUFB1 is a subunit of the enzyme NADH dehydrogenase (ubiquinone), the largest of the respiratory complexes. The structure is L-shaped with a long, hydrophobic transmembrane domain and a hydrophilic domain for the peripheral arm that includes all the known redox centers and the NADH binding site. NDUFB1 is one of about 31 hydrophobic subunits that form the transmembrane region of Complex I. It has been noted that the N-terminal hydrophobic domain has the potential to be folded into an alpha helix spanning the inner mitochondrial membrane with a C-terminal hydrophilic domain interacting with globular subunits of Complex I. The highly conserved two-domain structure suggests that this feature is critical for the protein function and that the hydrophobic domain acts as an anchor for the NADH dehydrogenase (ubiquinone) complex at the inner mitochondrial membrane.
Function
The human NDUFB1 gene codes for a subunit of Complex I of the respiratory chain, which transfers electrons from NADH to ubiquinone. However, NDUFB1 is an accessory subunit of the complex that is believed not to be involved in catalysis. Initially, NADH binds to Complex I and transfers two electrons to the isoalloxazine ring of the flavin mononucleotide (FMN) prosthetic arm to form FMNH2. The electrons are transferred through a series of iron-sulfur (Fe-S) clusters in the prosthetic arm and finally to coenzyme Q10 (CoQ), which is reduc |
https://en.wikipedia.org/wiki/Kleinschmidt%20Inc | Kleinschmidt Inc. was established in 1931 by Edward Kleinschmidt. It is a privately owned firm that provides electronic commerce, electronic data interchange, and value-added network services. Its headquarters are in Deerfield, Illinois.
Edward Kleinschmidt was one of the inventors of the teleprinter, one of the first electronic commerce devices.
History
1893 - Edward Ernst Kleinschmidt started working with telegraphy;
1898 - Edward E Kleinschmidt opened his own experimental shop;
1906 - George Seely joined Kleinschmidt’s shop with a partially developed block system for electric trolley car railways;
1910 - Exhibited at the Association of American Railroads Communications Convention;
1910 - Kleinschmidt started to receive multiple patents;
1914 - Kleinschmidt Electric Company was founded;
1924 - Kleinschmidt Electric merged with the Morkrum Company to form Morkrum-Kleinschmidt Corporation;
1928 - The company name was changed to Teletype Corporation;
1930 - The Teletype Corporation was sold to AT&T for $30,000,000 in stock;
1931 - Kleinschmidt Laboratories Inc. was founded;
1944 - Edward E. Kleinschmidt demonstrated his lightweight teleprinter at the Chief Signal Officer;
1949 - The Kleinschmidt 100-words-per-minute typebar page printer was made the standard for the Military;
1956 - Kleinschmidt Laboratories Inc. merged with Smith Corona which merged with Marchant Calculating Machine Company shortly thereafter, forming SCM;
1979 - Started to provide Electronic Data Interchange (EDI) and Car Location Message (CLM) services;
1986 - Hanson Trust acquired SCM Corporation. Harry S. Gaples, then Kleinschmidt division president, purchased the division from Hanson Trust.
See also
Edward Kleinschmidt
Electronic commerce
Electronic Data Interchange
Enterprise Application Integration
Supply Chain Management
Teletypewriter
Value-added network |
https://en.wikipedia.org/wiki/Mileva%20Prvanovi%C4%87 | Mileva Prvanović (born July 16, 1929 - 2016) was a Serbian differential geometer. She is a retired professor of mathematics at the University of Novi Sad and a member of the Serbian Academy of Sciences and Arts.
Education and career
Prvanović was born in Knjaževac on July 16, 1929, the daughter of mathematics professor Stanko Prvanović (1904–1982). After studying at the University of Belgrade, she earned a doctorate in 1955 from the University of Zagreb under the supervision of Danilo Blanuša, with a dissertation concerning differential geometry. In doing so, she became the first student in Serbia to earn a doctorate in geometry.
While completing her doctorate, she worked as a teaching assistant at the Serbian Academy of Sciences. Then, she joined the mathematics department at Novi Sad as an assistant professor. She was promoted to docent in 1957, associate professor in 1962, and full professor in 1967. She retired in 1993. As well as her professorial duties, she also served as editor in chief of the journal Publications de l'Institut Mathématique of the Mathematical Institute of the Serbian Academy of Sciences and Arts.
Recognition
Prvanović was elected to the Serbian Academy of Sciences and Arts in 1981.
A seminar in Vrnjačka Banja was held in 2014 in honor of her 85th birthday. |
https://en.wikipedia.org/wiki/Criminology | Criminology (from Latin , "accusation", and Ancient Greek , -logia, from λόγος logos meaning: "word, reason") is the interdisciplinary study of crime and deviant behaviour. Criminology is a multidisciplinary field in both the behavioural and social sciences, which draws primarily upon the research of sociologists, political scientists, economists, legal sociologists, psychologists, philosophers, psychiatrists, social workers, biologists, social anthropologists, scholars of law and jurisprudence, as well as the processes that define administration of justice and the criminal justice system.
Criminologists are individuals who engage in the exploration and investigation of the intersection between crime and society's reactions to it. Certain criminologists delve into the behavioral trends of potential offenders. In a broader sense, these professionals undertake research and inquiries, formulating hypotheses, and scrutinizing observable trends in a systematic manner.
The interests of criminologists include the study of nature of crime and criminals, origins of criminal law, etiology of crime, social reaction to crime, and the functioning of law enforcement agencies and the penal institutions. It can be broadly said that criminology directs its inquiries along three lines: first, it investigates the nature of criminal law and its administration and conditions under which it develops; second, it analyzes the causation of crime and the personality of criminals; and third, it studies the control of crime and the rehabilitation of offenders. Thus, criminology includes within its scope the activities of legislative bodies, law-enforcement agencies, judicial institutions, correctional institutions and educational, private and public social agencies.
History of academic criminology
Modern academic criminology has direct roots in the 19th-century Italian School of "criminal anthropology", which according to the historian Mary Gibson "caused a radical refocusing of criminolog |
https://en.wikipedia.org/wiki/Waterfall%20%28M.%20C.%20Escher%29 | Waterfall () is a lithograph by the Dutch artist M. C. Escher, first printed in October 1961. It shows a perpetual motion machine where water from the base of a waterfall appears to run downhill along the water path before reaching the top of the waterfall.
While most two-dimensional artists use relative proportions to create an illusion of depth, Escher here and elsewhere uses conflicting proportions to create a visual paradox. The watercourse supplying the waterfall (its aqueduct or leat) has the structure of two Penrose triangles. A Penrose triangle is an impossible object designed by Oscar Reutersvärd in 1934, and found independently by Roger Penrose in 1958.
Description
The image depicts a watermill with an elevated aqueduct and waterwheel as the main feature. The aqueduct begins at the waterwheel and flows behind it. The walls of the aqueduct step downward, suggesting that it slopes downhill. The aqueduct turns sharply three times, first to the left, then to the right, and finally to the left again. The viewer looks down at the scene diagonally, which means that from the viewer's perspective the aqueduct appears to be slanted upward. The viewer is also looking across the scene diagonally from the lower right, which means that from the viewer's perspective the two left-hand turns are directly in line with each other, while the waterwheel, the forward turn and the end of the aqueduct are all in line. The second left-hand turn is supported by pillars from the first, while the other two corners are supported by a tower of pillars that begins at the waterwheel. The water falls off the edge of the aqueduct and over the waterwheel in an impossible infinite cycle; in his notes on the picture, Escher points out that some water must be periodically added to this perpetual motion machine to compensate for evaporation. The use of the Penrose stairs is paralleled by Escher's Ascending and Descending (1960), where instead of the flow of water, two lines of monks endlessly |
https://en.wikipedia.org/wiki/Eulerian%20matroid | In matroid theory, an Eulerian matroid is a matroid whose elements can be partitioned into a collection of disjoint circuits.
Examples
In a uniform matroid , the circuits are the sets of exactly elements. Therefore, a uniform matroid is Eulerian if and only if is a divisor of . For instance, the -point lines are Eulerian if and only if is divisible by three.
The Fano plane has two kinds of circuits: sets of three collinear points, and sets of four points that do not contain any line. The three-point circuits are the complements of the four-point circuits, so it is possible to partition the seven points of the plane into two circuits, one of each kind. Thus, the Fano plane is also Eulerian.
Relation to Eulerian graphs
Eulerian matroids were defined by as a generalization of the Eulerian graphs, graphs in which every vertex has even degree. By Veblen's theorem the edges of every such graph may be partitioned into simple cycles, from which it follows that the graphic matroids of Eulerian graphs are examples of Eulerian matroids.
The definition of an Eulerian graph above allows graphs that are disconnected, so not every such graph has an Euler tour. observes that the graphs that have Euler tours can be characterized in an alternative way that generalizes to matroids: a graph has an Euler tour if and only if it can be formed from some other graph , and a cycle in , by contracting the edges of that do not belong to . In the contracted graph, generally stops being a simple cycle and becomes instead an Euler tour. Analogously, Wilde considers the matroids that can be formed from a larger matroid by contracting the elements that do not belong to some particular circuit. He shows that this property is trivial for general matroids (it implies only that each element belongs to at least one circuit) but can be used to characterize the Eulerian matroids among the binary matroids, matroids representable over GF(2):
a binary matroid is Eulerian if and only if it is th |
https://en.wikipedia.org/wiki/Glycolic%20acid | Glycolic acid (or hydroxyacetic acid; chemical formula ) is a colorless, odorless and hygroscopic crystalline solid, highly soluble in water. It is used in various skin-care products. Glycolic acid is widespread in nature. A glycolate (sometimes spelled "glycollate") is a salt or ester of glycolic acid.
History
The name "glycolic acid" was coined in 1848 by French chemist Auguste Laurent (1807–1853). He proposed that the amino acid glycine—which was then called glycocolle—might be the amine of a hypothetical acid, which he called "glycolic acid" (acide glycolique).
Glycolic acid was first prepared in 1851 by German chemist Adolph Strecker (1822–1871) and Russian chemist Nikolai Nikolaevich Sokolov (1826–1877). They produced it by treating hippuric acid with nitric acid and nitrogen dioxide to form an ester of benzoic acid and glycolic acid (), which they called "benzoglycolic acid" (Benzoglykolsäure; also benzoyl glycolic acid). They boiled the ester for days with dilute sulfuric acid, thereby obtaining benzoic acid and glycolic acid (Glykolsäure).
Preparation
Glycolic acid can be synthesized in various ways. The predominant approaches use a catalyzed reaction of formaldehyde with synthesis gas (carbonylation of formaldehyde), for its low cost.
It is also prepared by the reaction of chloroacetic acid with sodium hydroxide followed by re-acidification.
Other methods, not noticeably in use, include hydrogenation of oxalic acid, and hydrolysis of the cyanohydrin derived from formaldehyde. Some of today's glycolic acids are formic acid-free. Glycolic acid can be isolated from natural sources, such as sugarcane, sugar beets, pineapple, cantaloupe and unripe grapes.
Glycolic acid can also be prepared using an enzymatic biochemical process that may require less energy.
Properties
Glycolic acid is slightly stronger than acetic acid due to the electron-withdrawing power of the terminal hydroxyl group. The carboxylate group can coordinate to metal ions forming coord |
https://en.wikipedia.org/wiki/Terpene | Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n ≥ 2. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predominantly by plants, particularly conifers. Terpenes are further classified by the number of carbons: monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), as examples. The terpene alpha-pinene is a major component of the common solvent, turpentine.
History and terminology
The term terpene was coined in 1866 by the German chemist August Kekulé to denote all hydrocarbons having the empirical formula C10H16, of which camphene was one. Previously, many hydrocarbons having the empirical formula C10H16 had been called "camphene", but many other hydrocarbons of the same composition had had different names. Kekulé coined the term "terpene" in order to reduce the confusion. The name "terpene" is a shortened form of "terpentine", an obsolete spelling of "turpentine".
Although sometimes used interchangeably with "terpenes", terpenoids (or isoprenoids) are modified terpenes that contain additional functional groups, usually oxygen-containing. The terms terpenes and terpenoids are often used interchangeably, however. Furthermore, terpenes are produced from terpenoids and many terpenoids are produced from terpenes. Both have strong and often pleasant odors, which may protect their hosts or attract pollinators. The number of terpenes and terpenoids is estimated at 55,000 chemical entities.
The 1939 Nobel Prize in Chemistry was awarded to Leopold Ružička "for his work on polymethylenes and higher terpenes", "including the first chemical synthesis of male sex hormones."
Biological function
Terpenes are major biosynthetic building blocks. Steroids, for example, are derivatives of the triterpene squalene. Terpenes and terpenoids are also the primary constituents of the essential oils of many types of plants and flowers. In plants, terpenes and terpenoids are important mediators of |
https://en.wikipedia.org/wiki/Timed%20propositional%20temporal%20logic | In model checking, a field of computer science, timed propositional temporal logic (TPTL) is an extension of propositional linear temporal logic (LTL) in which variables are introduced to measure times between two events. For example, while LTL allows to state that each event p is eventually followed by an event q, TPTL furthermore allows to give a time limit for q to occur.
Syntax
The future fragment of TPTL is defined similarly to linear temporal logic, in which furthermore, clock variables can be introduced and compared to constants. Formally, given a set of clocks, MTL is built up from:
a finite set of propositional variables AP,
the logical operators ¬ and ∨, and
the temporal modal operator U,
a clock comparison , with , a number and a comparison operator such as <, ≤, =, ≥ or >.
a freeze quantification operator , for a TPTL formula with set of clocks .
Furthermore, for an interval, is considered as an abbreviation for ; and similarly for every other kind of intervals.
The logic TPTL+Past is built as the future fragment of TLS and also contains
the temporal modal operator S.
Note that the next operator N is not considered to be a part of MTL syntax. It will instead be defined from other operators.
A closed formula is a formula over an empty set of clocks.
Models
Let , which intuitively represents a set of times. Let a function that associates to each moment a set of propositions from AP. A model of a TPTL formula is such a function . Usually, is either a timed word or a signal. In those cases, is either a discrete subset or an interval containing 0.
Semantics
Let and be as above. Let be a set of clocks. Let (a clock valuation over ).
We are now going to explain what it means for a TPTL formula to hold at time for a valuation . This is denoted by .
Let and be two formulas over the set of clocks , a formula over the set of clocks , , , a number and being a comparison operator such as <, ≤, =, ≥ or >:
We first consider form |
https://en.wikipedia.org/wiki/Flora%20of%20the%20Venezuelan%20Guayana | Flora of the Venezuelan Guayana is a multivolume flora describing the vascular plants of the Guayana Region of Venezuela, encompassing the three states south of the Orinoco: Amazonas, Bolívar, and Delta Amacuro. Initiated by Julian Alfred Steyermark in the early 1980s, it was completed after his death under the guidance of Paul E. Berry, Kay Yatskievych, and Bruce K. Holst. The nine volumes were published between 1995 and 2005 by Timber Press and Missouri Botanical Garden Press. The project brought together more than 200 botanists from around the world and was "the first effort to produce a comprehensive inventory and identification guide for the plants of such an extensive region of northern South America".
Volumes
The first volume, written primarily by Italian ecologist Otto Huber, is an introduction to the geography, ecology, botanical history and conservation of the Venezuelan Guayana, and includes two fold-out maps of the region (one vegetation and one topographical, both 1:2,000,000 scale). The subsequent eight volumes cover the known plant families of the area in alphabetical order, each treating around 1000–1300 species. Ferns and fern allies are covered in the first part of volume 2, with the remainder of that volume, and the rest of the flora, devoted to seed plants (generally following the Cronquist system for flowering plants). Both native and naturalised species are included. Around half of all species are illustrated with black-and-white line drawings by Venezuelan artist Bruno Manara. Species accounts include non-exhaustive synonymies, and vernacular names are occasionally given.
Volume 1, Introduction (1995). . 363 pp.
Volume 2, Pteridophytes, Spermatophytes, Acanthaceae–Araceae (1995). . 706 pp., 1285 species treated, 618 line drawings.
Volume 3, Araliaceae–Cactaceae (1997). . 792 pp., 1113 species treated, 628 line drawings.
Volume 4, Caesalpiniaceae–Ericaceae (1998). . 799 pp., 1329 species treated, 621 line drawings.
Volume 5, Eriocaulacea |
https://en.wikipedia.org/wiki/Benny%20Benson | John Ben Benson Jr. (September 12, 1912 – July 2, 1972) was an Alaska native best known for designing the flag of Alaska. Benson was age 14 years old when he won a contest in 1927 to design the flag for the Territory of Alaska, which became a U.S. state on January 3, 1959.
Life
Early life
Benson was born in Chignik, Alaska, on September 12, 1912. He was a Qawalangin (Fox Islander) Unangan born to a Swedish-American father, John Ben "Benny" Benson Sr., and Aleut-Russian mother, Tatiana Ioannovna Dediukhina, from a village near Unalaska. When he was three years old, his mother died, forcing his father to send him and his brother Carl to an orphanage, as Benson's father could not take care of them. Benson grew up at the Jesse Lee Home for Children in Unalaska and later in Seward.
Fox Farm
After graduating from school in 1932, Benson left the Jesse Lee Home. He returned to the Aleutian Islands to work with his father fishing and, for a time, trapping blue foxes on Chirikof Island and on John's privately own Ugaiushak Island. The rate for furs began to decline, so Benson moved to Seattle in 1936. He used the $1,000 prize from the flag design competition to enroll in the Hemphill Diesel Engineering School for Diesel engine repair. In 1938, Benson married Betty Van Hise. The couple's first child, Anna May, was born in October 1938. Their second daughter, Charlotte Abbot, was born in June 1940. Benson divorced in 1950 and moved with his daughters to Kodiak where he became an airplane mechanic for Kodiak Airways.
Later years and death
Benson met his sister in the mid 1950s, 30 years after their separation. His sister died soon after. His brother Carl also died in 1965. Benson's right leg had to be amputated in 1969 due to circulatory problems. Shortly after that, in 1972, he met and married a former Jesse Lee Home resident, Anna Sophie Jenks. Benson had several stepchildren and grandchildren. He died of a heart attack in Kodiak, Alaska, on July 2 of that year, at the |
https://en.wikipedia.org/wiki/Range%20of%20a%20projectile | In physics, a projectile launched with specific initial conditions will have a range. It may be more predictable assuming a flat Earth with a uniform gravity field, and no air resistance. The horizontal ranges of a projectile are equal for two complementary angles of projection with the same velocity.
The following applies for ranges which are small compared to the size of the Earth. For longer ranges see sub-orbital spaceflight. The maximum horizontal distance traveled by the projectile, neglecting air resistance, can be calculated as follows:
where
d is the total horizontal distance travelled by the projectile.
v is the velocity at which the projectile is launched
g is the gravitational acceleration—usually taken to be 9.81 m/s2 (32 f/s2) near the Earth's surface
θ is the angle at which the projectile is launched
y0 is the initial height of the projectile
If y0 is taken to be zero, meaning that the object is being launched on flat ground, the range of the projectile will simplify to:
Ideal projectile motion
Ideal projectile motion states that there is no air resistance and no change in gravitational acceleration. This assumption simplifies the mathematics greatly, and is a close approximation of actual projectile motion in cases where the distances travelled are small. Ideal projectile motion is also a good introduction to the topic before adding the complications of air resistance.
Derivations
A launch angle of 45 degrees displaces the projectile the farthest horizontally.
This is due to the nature of right triangles. Additionally, from the equation for the range :
We can see that the range will be maximum when the value of is the highest (i.e. when it is equal to 1).
Clearly, has to be 90 degrees. That is to say, is 45 degrees.
Flat ground
First we examine the case where (y0) is zero. The horizontal position of the projectile is
In the vertical direction
We are interested in the time when the projectile returns to the same height |
https://en.wikipedia.org/wiki/Physiological%20agonism%20and%20antagonism | Physiological agonism describes the action of a substance which ultimately produces the same effects in the body as another substance—as if they were both agonists at the same receptor—without actually binding to the same receptor. Physiological antagonism describes the behavior of a substance that produces effects counteracting those of another substance (a result similar to that produced by an antagonist blocking the action of an agonist at the same receptor) using a mechanism that does not involve binding to the same receptor.
Examples
Physiological agonists
Epinephrine induces platelet aggregation, and so does hepatocyte growth factor (HGF). Thus, they are physiological agonists to each other.
Physiological antagonists
There are several substances that have antihistaminergic action despite not being ligands for the histamine receptor. For instance, epinephrine raises arterial pressure through vasoconstriction mediated by A1-adrenergic receptor activation, in contrast to histamine, which lowers arterial pressure. Thus, despite not being true antihistamines because they do not bind to and block the histamine receptor, epinephrine and other such substances are physiological antagonists to histamine. |
https://en.wikipedia.org/wiki/Armstrong%20oscillator | The Armstrong oscillator (also known as the Meissner oscillator) is an electronic oscillator circuit which uses an inductor and capacitor to generate an oscillation. It is the earliest oscillator circuit, invented by US engineer Edwin Armstrong in 1912 and independently by Austrian engineer Alexander Meissner in 1913, and was used in the first vacuum tube radio transmitters. It is sometimes called a tickler oscillator because its distinguishing feature is that the feedback signal needed to produce oscillations is magnetically coupled into the tank inductor in the input circuit by a "tickler coil" (L2, right) in the output circuit. Assuming the coupling is weak but sufficient to sustain oscillation, the oscillation frequency f is determined primarily by the LC circuit (tank circuit L1 and C in the figure on the right) and is approximately given by
This circuit was widely used in the regenerative radio receiver, popular until the 1940s. In that application, the input radio frequency signal from the antenna is magnetically coupled into the LC circuit by an additional winding, and the feedback is reduced with adjustable gain control in the feedback loop, so the circuit is just short of oscillation. The result is a narrow-band radio-frequency filter and amplifier. The non-linear characteristic of the transistor or tube also demodulated the RF signal to produce the audio signal.
The circuit diagram shown is a modern implementation, using a field-effect transistor as the amplifying element. Armstrong's original design used a triode vacuum tube.
In the Meissner variant, the LC resonant circuit is exchanged with the feedback coil, i.e., in the output path (vacuum tube plate, field-effect transistor drain, or bipolar transistor collector) of the amplifier (e.g., Grebennikov, Fig. 2.8). Many publications, however, embrace both variants with either name. English speakers call it the "Armstrong oscillator", whereas German speakers call it the "Meißner oscillator".
See als |
https://en.wikipedia.org/wiki/Anamorphosis | Anamorphosis is a distorted projection that requires the viewer to occupy a specific vantage point, use special devices, or both to view a recognizable image. It is used in painting, photography, sculpture and installation, toys, and film special effects. The word is derived from the Greek prefix ana-, meaning "back" or "again", and the word morphe, meaning "shape" or "form". Extreme anamorphosis has been used by artists to disguise caricatures, erotic and scatological scenes, and other furtive images from a casual spectator, while revealing an undistorted image to the knowledgeable viewer.
Types of projection
There are two main types of anamorphosis: perspective (oblique) and mirror (catoptric). More complex anamorphoses can be devised using distorted lenses, mirrors, or other optical transformations.
An oblique anamorphism forms an affine transformation of the subject. Early examples of perspectival anamorphosis date to the Renaissance of the fifteenth century and largely relate to religious themes.
With mirror anamorphosis, a conical or cylindrical mirror is placed on the distorted drawing or painting to reveal an undistorted image. The deformed picture relies on laws regarding angles of incidence of reflection. The length of the flat drawing's curves are reduced when viewed in a curved mirror, such that the distortions resolve into a recognizable picture. Unlike perspective anamorphosis, catoptric images can be viewed from many angles. The technique was originally developed in China during the Ming Dynasty, and the first European manual on mirror anamorphosis was published around 1630 by the mathematician Vaulezard.
Channel anamorphosis or tabula scalata has a different image on each side of a corrugated carrier. A straight frontal view shows an unclear mix of the images, while each image can be viewed correctly from a certain angle.
History
Prehistory
The Stone Age cave paintings at Lascaux may make use of anamorphic technique, because the oblique angle |
https://en.wikipedia.org/wiki/Quadrisecant | In geometry, a quadrisecant or quadrisecant line of a space curve is a line that passes through four points of the curve. This is the largest possible number of intersections that a generic space curve can have with a line, and for such curves the quadrisecants form a discrete set of lines. Quadrisecants have been studied for curves of several types:
Knots and links in knot theory, when nontrivial, always have quadrisecants, and the existence and number of quadrisecants has been studied in connection with knot invariants including the minimum total curvature and the ropelength of a knot.
The number of quadrisecants of a non-singular algebraic curve in complex projective space can be computed by a formula derived by Arthur Cayley.
Quadrisecants of arrangements of skew lines touch subsets of four lines from the arrangement. They are associated with ruled surfaces and the Schläfli double six configuration.
Definition and motivation
A quadrisecant is a line that intersects a curve, surface, or other set in four distinct points. It is analogous to a secant line, a line that intersects a curve or surface in two points; and a trisecant, a line that intersects a curve or surface in three points.
Compared to secants and trisecants, quadrisecants are especially relevant for space curves, because they have the largest possible number of intersection points of a line with a generic curve. In the plane, a generic curve can be crossed arbitrarily many times by a line; for instance, small generic perturbations of the sine curve are crossed infinitely often by the horizontal axis. In contrast, if an arbitrary space curve is perturbed by a small distance to make it generic, there will be no lines through five or more points of the perturbed curve. Nevertheless, any quadrisecants of the original space curve will remain present nearby in its perturbation.
One explanation for this phenomenon is visual: looking at a space curve from far away, the space of such points of view can be d |
https://en.wikipedia.org/wiki/Alfred%20Young%20%28mathematician%29 | Alfred Young, FRS (16 April 1873 – 15 December 1940) was a British mathematician.
He was born in Widnes, Lancashire, England, and educated at Monkton Combe School in Somerset and Clare College, Cambridge, graduating BA as 10th Wrangler in 1895. He is known for his work in the area of group theory. Both Young diagrams and Young tableaux (which he introduced in 1900) are named after him.
Young was appointed to the position of lecturer at Selwyn College, Cambridge, in 1901, transferring to Clare College in 1905. In 1902 he collaborated with John Hilton Grace on the book The Algebra of Invariants.
In 1907 he married Edith Clara née Wilson. In 1908 he became an ordained clergyman, and in 1910 became parish priest at Birdbrook in Essex, a village 25 miles east of Cambridge. He lived there for the rest of his life, but in 1926 began lecturing once again at Cambridge.
Most of his long series of papers on invariant theory and the symmetric group were written while he was a clergyman.
See also
Hyperoctahedral group
Young's lattice
Young–Fibonacci lattice
Young symmetrizer
Representation theory of the symmetric group |
https://en.wikipedia.org/wiki/Backward%20compatibility | Backward compatibility (sometimes known as backwards compatibility) is a property of an operating system, software, real-world product, or technology that allows for interoperability with an older legacy system, or with input designed for such a system, especially in telecommunications and computing.
Modifying a system in a way that does not allow backward compatibility is sometimes called "breaking" backward compatibility. Such breaking usually incurs various types of costs, such as switching cost.
A complementary concept is forward compatibility. A design that is forward-compatible usually has a roadmap for compatibility with future standards and products.
Usage
In hardware
A simple example of both backward and forward compatibility is the introduction of FM radio in stereo. FM radio was initially mono, with only one audio channel represented by one signal. With the introduction of two-channel stereo FM radio, many listeners had only mono FM receivers. Forward compatibility for mono receivers with stereo signals was achieved by sending the sum of both left and right audio channels in one signal and the difference in another signal. That allows mono FM receivers to receive and decode the sum signal while ignoring the difference signal, which is necessary only for separating the audio channels. Stereo FM receivers can receive a mono signal and decode it without the need for a second signal, and they can separate a sum signal to left and right channels if both sum and difference signals are received. Without the requirement for backward compatibility, a simpler method could have been chosen.
Full backward compatibility is particularly important in computer instruction set architectures, one of the most successful being the x86 family of microprocessors. Their full backward compatibility spans back to the 16-bit Intel 8086/8088 processors introduced in 1978. (The 8086/8088, in turn, were designed with easy machine-translatability of programs written for its prede |
https://en.wikipedia.org/wiki/IEEE%20P1619 | Institute of Electrical and Electronics Engineers (IEEE) standardization project for encryption of stored data, but more generically refers to the Security in Storage Working Group (SISWG), which includes a family of standards for protection of stored data and for the corresponding cryptographic key management.
Standards
SISWG oversees work on the following standards:
The base IEEE 1619 Standard Architecture for Encrypted Shared Storage Media uses the XTS-Advanced Encryption Standard (XEX-based Tweaked CodeBook mode (TCB) with ciphertext stealing (CTS); the proper name should be XTC (XEX TCB CTS), but that acronym is already used to denote the drug ecstasy.
The P1619.1 Authenticated Encryption with Length Expansion for Storage Devices uses the following algorithms:
Counter mode with CBC-MAC (CCM)
Galois/Counter Mode (GCM)
Cipher Block Chaining (CBC) with HMAC-Secure Hash Algorithm
XTS-HMAC-Secure Hash Algorithm
The P1619.2 Standard for Wide-Block Encryption for Shared Storage Media has proposed algorithms including:
XCB
EME2
The P1619.3 Standard for Key Management Infrastructure for Cryptographic Protection of Stored Data defines a system for managing encryption data at rest security objects which includes architecture, namespaces, operations, messaging and transport.
P1619 also standardized the key backup in the XML format.
Narrow-block vs. wide-block encryption
An encryption algorithm used for data storage has to support independent encryption and decryption of portions of data. So-called narrow-block algorithms operate on relatively small portions of data, while the wide-block algorithms encrypt or decrypt a whole sector. Narrow-block algorithms have the advantage of more efficient hardware implementation. On the other hand, smaller block size provides finer granularity for data modification attacks. There is no standardized "acceptable granularity"; however, for example, the possibility of data modification with the granularity of one bit (bit-f |
https://en.wikipedia.org/wiki/Sarawak%20Biodiversity%20Centre | Sarawak Biodiversity Centre is a statutory body that was set up by the government of Sarawak in 1997 for the regulation of access and collection of biological resources for research or commercial purposes. In 2004, the centre was relieved of its regulatory role and started to get involved in biotechnology-based research on the biological resources in the state.
History
Sarawak Biodiversity Centre (SBC) was established in 1997 following the enactment of the Sarawak Biodiversity Centre Ordinance by the Sarawak state government for conservation, utilization, protection and sustainable development of biodiversity in the state. This was followed by the enactment of Sarawak Biodiversity Regulations in 1998. In December 2003, the Sarawak State Legislative Assembly passed the Sarawak Biodiversity Centre (Amendment) Ordinance 2003. The state assembly also revised the Sarawak Biodiversity Regulations in 2004. Following these revisions, Sarawak Biodiversity Centre was relieved of its previous role and assumed a new role of research and development of the state biological resources and documentation of indigenous knowledge of utilising biological resources. In 2017, SBC hosted BioBorneo and Bioeconomy Day.
SBC collaborated with Mitsubishi Corporation on cultivating indigenous algae since 2012. In 2019, SBC and Mitsubishi launched one of the largest algae cultivation facility in Southeast Asia. It is expected to produce 60 tonnes of dried algae biomass per hectare per year.
Programmes
Traditional Knowledge Documentation Programme
This programme exists to prevent the loss of traditional knowledge in indigenous communities because knowledge is passed to the next generations only through oral tradition. This programme is carried out through capacity-building workshops where local communities are trained with documentation techniques as well as growing and management of useful indigenous plants. As of 9 November 2020, a total of 6,420 plants were documented with 1,713 species of |
https://en.wikipedia.org/wiki/Discovery%20and%20development%20of%20phosphodiesterase%205%20inhibitors | Phosphodiesterases (PDEs) are a superfamily of enzymes. This superfamily is further classified into 11 families, PDE1 - PDE11, on the basis of regulatory properties, amino acid sequences, substrate specificities, pharmacological properties and tissue distribution. Their function is to degrade intracellular second messengers such as cyclic adenine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) which leads to several biological processes like effect on intracellular calcium level by the Ca2+ pathway.
Phosphodiesterase 5 (PDE5) is widely expressed in several tissues in the body for example brain, lung, kidney, urinary bladder, smooth muscle and platelets. It is possible to prevent cGMP hydrolysis by inhibiting PDE5 and therefore treat diseases associated with low cGMP levels, because of this, PDE5 is an ideal target for the development of inhibitors. The therapeutic effects of PDE5 inhibition have been demonstrated in several cardiovascular conditions, chronic kidney disease and diabetes mellitus.
The major PDE5 inhibitors (a subset of the phosphodiesterase inhibitors) are sildenafil, tadalafil, vardenafil, and avanafil, and although all share the same mechanism of action each has unique pharmacokinetic and pharmacodynamic properties which dictate their suitability in various conditions and their side effect profile.
General
The human genome contains at least 21 genes involved in determining the intracellular levels of cAMP and cGMP by the expression of phosphodiesterase proteins or PDE's. These PDE's are grouped into at least 11 functional subfamilies, named PDE1-PDE11. PDEs are enzymes that hydrolyze cyclic adenosine 3,5-monophosphate (cAMP) and cyclic guanosine 3,5-monophospahate (cGMP), which are intracellular second messengers, into AMP and GMP. These second messengers control many physiological processes.
The cAMP is formed from ATP by the enzyme adenylyl cyclase and cGMP is formed from GTP by the enzyme guanylyl cyclase which are either membr |
https://en.wikipedia.org/wiki/2-Fluoroethanol | 2-Fluoroethanol is the organic compound with the formula CH2FCH2OH. This colorless liquid is one of the simplest stable fluorinated alcohols. It was once used as a pesticide. The related difluoro- and trifluoroethanols are far less dangerous.
Synthesis
2-Fluoroethanol was originally synthesized by treating 2-chloroethanol with potassium fluoride, in a simple Finkelstein reaction. The product has a lower boiling point that the starting material and may be conveniently isolated by distillation.
ClCH2CH2OH + KF → FCH2CH2OH + KCl
Similar procedures start from (1,3)-dioxolan-2-one and from 2-bromoethanol.
Structure and reactivity
Hydrogen bonding stabilizes the gauche conformer.
In a basic solution, 2-fluoroethanol undergoes dehydrofluorination, giving acetaldehyde.
Reaction of 2-fluoroethanol with trifluoromethanesulfonic anhydride in the presence of base gives the triflate ester.
PET radiotracers
2-[18F]-fluoroethoxy group is a common moiety in the structures of radiotracers used with PET. Such radiotracers include fluoroethyl-l-tyrosine 1-(2-[18F]-fluoroethoxy)-4-nitrobenzene and [18F]-fluoroethyl 4-fluorobenzoate, being a [18F]fluoroalkyl ether and ester respectively.
Metabolism
It was patented as a rodenticide in Germany in 1935. In rats, it was found that fluoroethanol induced a similar toxicity as that of fluoroacetate, known to metabolize to fluorocitrate to exert the toxic effect.
2-Fluoroethanol is converted by alcohol dehydrogenase (ADH) using nicotinamide adenine dinucleotide (NAD+) as cofactor, ultimately leading to the formation of fluoroacetaldehyde and then fluoroacetate.
Fluoroacetate is a precursor to fluorocitrate, an inhibitor of aconitase, an enzyme that participates in the TCA cycle.
Toxicity
Reported effects of 2-fluoroethanol are epigastric distress effects, such as vomiting, and central nervous effects, such as auditory hallucinations, numbness feeling of the face or nose. Both these types of effects occur gradually after being expose |
https://en.wikipedia.org/wiki/Thin-film%20lithium-ion%20battery | The thin film lithium-ion battery is a form of solid-state battery. Its development is motivated by the prospect of combining the advantages of solid-state batteries with the advantages of thin-film manufacturing processes.
Thin-film construction could lead to improvements in specific energy, energy density, and power density on top of the gains from using a solid electrolyte. It allows for flexible cells only a few microns thick. It may also reduce manufacturing costs from scalable roll-to-roll processing and even allow for the use of cheap materials.
Background
Lithium-ion batteries store chemical energy in reactive chemicals at the anodes and cathodes of a cell. Typically, anodes and cathodes exchange lithium (Li+) ions through a fluid electrolyte that passes through a porous separator which prevents direct contact between the anode and cathode. Such contact would lead to an internal short circuit and a potentially hazardous uncontrolled reaction. Electric current is usually carried by conductive collectors at the anodes and cathodes to and from the negative and positive terminals of the cell (respectively).
In a thin-film lithium battery the electrolyte is solid and the other components are deposited in layers on a substrate. In some designs, the solid electrolyte also serves as a separator.
Components of thin film battery
Cathode materials
Cathode materials in thin film lithium ion batteries are the same as in classical lithium ion batteries. They are normally metal oxides that are deposited as a film by various methods.
Metal oxide materials are shown below as well as their relative specific capacities (), open circuit voltages (), and energy densities ().
Deposition methods for cathode materials
There are various methods being used to deposit thin film cathode materials onto the current collector.
Pulsed Laser Deposition
In Pulsed Laser Deposition, materials are fabricated by controlling parameters such as laser energy and fluence, substrate temperat |
https://en.wikipedia.org/wiki/Calcomp | Calcomp Technology, Inc., often referred to as Calcomp or CalComp, was a company best known for its Calcomp plotters.
History
It was founded as California Computer Products, Inc in 1959, located in Anaheim, California.
Sanders Associates, Inc., purchased Calcomp in 1980. In 1986, Sanders Associates was purchased by the Lockheed Corporation, and merged into Lockheed's Information Systems Group. Lockheed kept CalComp as a brand name.
Shutdown
Calcomp Technology shut down its operations in 1999, and transferred different product lines to various other companies, some of whom continue to use the "Calcomp" or other "Cal-" trademarks:
Technical Services and spare parts: CalGraph Technology Services, Inc.
TechJet 5500 Large Format Inkjet Plotter / Printer Information: CalComp Graphics.
Digitizer, Tablets and scanners: GTCO CalComp, Inc.
Film Imaging Systems: EcoPro Imaging (now part of OYO Instruments)
Cutter and sign maker products: Westcomp
Products
It produced a wide range of plotters (both drum and flat-bed), digitizers, thermal transfer color printers, thermal plotters (InfoWorld June 13, 1994 p. 40) and other graphic input/output devices. In 1969, it produced about 80% of all plotters worldwide.
It also produced IBM plug compatible (PCM) disk and tape products. The disk products ranged from 2311 (CD-1,5, 17, 18, 24, 25) through 3350 equivalents. The tape product was a 3420 equivalent.
Calcomp acquired Talos and Summagraphics, which had acquired Houston Instruments.
Houston Instruments
Houston Instruments was another manufacturer of pen plotters. They used the DMPL plotting control language. They competed with Hewlett Packard plotters such as the HP 7470.
They were purchased by Summagraphics.
DMP-29
DMP-40, DMP-41, DMP-42
DMP-50, DMP-51, DMP-51MP, DMP-52, DMP-52MP, DMP-55, DMP-56
DMP-60, DMP-61, DMP-61DL, DMP-62, DMP-62DL, DMP-63, DMP-64, DMP-65C
DMP-161, DMP-162, DMP-162R
Computer division
In 1987, CalComp sold its computer division to a company th |
https://en.wikipedia.org/wiki/Blazhko%20effect | The Blazhko effect, also known as the Tseraskaya–Blazhko effect, and which is sometimes called long-period modulation, is a variation in period and amplitude in RR Lyrae type variable stars. It was first observed by Sergey Blazhko in 1907 in the star RW Draconis.
The physics behind the Blazhko effect is currently still a matter of debate, with there being three primary hypotheses.
In the first, referred to as the resonance model, the cause of the modulation is a non-linear resonance among either the fundamental or the first overtone pulsation mode of the star and a higher mode. The second, known as the magnetic model, assumes the variation to be caused by the magnetic field being inclined to the rotational axis, deforming the main radial mode. The magnetic model was ruled out in 2004 by high resolution spectro-polarimetric observations. The third model assumes that cycles in the convection cause the alternations and the modulations.
Observational evidence based on Kepler observations indicates much of the Blazhko effect's two-cycle light curve modulation is due to simple period-doubling. Many RR Lyrae stars have a variability period of approximately 12 hours and ground-based astronomers typically make nightly observations about 24 hours apart; thus period-doubling results in brightness maximums during nightly observations that are significantly different from the daytime maximum. |
https://en.wikipedia.org/wiki/Data%20compression%20symmetry | Symmetry and asymmetry, in the context of data compression, refer to the time relation between compression and decompression for a given compression algorithm.
If an algorithm takes the same time to compress a data archive as it does to decompress it, it is considered symmetrical. Note that compression and decompression, even for a symmetric algorithm, may not be perfectly symmetric in practice, depending on the devices the data is being copied to and from, and other factors such as latency and the fragmentation on the device.
In turn, if the compression and decompression times of an algorithm are vastly different, it is considered asymmetrical.
Examples
Symmetric algorithms are typically used for media streaming protocols, as either the server taking too long to compress the data, or the client taking too long to decompress, would lead to delays in the viewing of the data.
Asymmetrical algorithms wherein the compression is faster than the decompression can be useful for backing up or archiving data, as in these cases data is typically much more often stored than retrieved. |
https://en.wikipedia.org/wiki/Augustin-Jean%20Fresnel | Augustin-Jean Fresnel (10 May 1788 – 14 July 1827) was a French civil engineer and physicist whose research in optics led to the almost unanimous acceptance of the wave theory of light, excluding any remnant of Newton's corpuscular theory, from the late 1830s until the end of the 19th century. He is perhaps better known for inventing the catadioptric (reflective/refractive) Fresnel lens and for pioneering the use of "stepped" lenses to extend the visibility of lighthouses, saving countless lives at sea. The simpler dioptric (purely refractive) stepped lens, first proposed by Count Buffon and independently reinvented by Fresnel, is used in screen magnifiers and in condenser lenses for overhead projectors.
By expressing Huygens's principle of secondary waves and Young's principle of interference in quantitative terms, and supposing that simple colors consist of sinusoidal waves, Fresnel gave the first satisfactory explanation of diffraction by straight edges, including the first satisfactory wave-based explanation of rectilinear propagation. Part of his argument was a proof that the addition of sinusoidal functions of the same frequency but different phases is analogous to the addition of forces with different directions. By further supposing that light waves are purely transverse, Fresnel explained the nature of polarization, the mechanism of chromatic polarization, and the transmission and reflection coefficients at the interface between two transparent isotropic media. Then, by generalizing the direction-speed-polarization relation for calcite, he accounted for the directions and polarizations of the refracted rays in doubly-refractive crystals of the biaxial class (those for which Huygens's secondary wavefronts are not axisymmetric). The period between the first publication of his pure-transverse-wave hypothesis, and the submission of his first correct solution to the biaxial problem, was less than a year.
Later, he coined the terms linear polarization, circular |
https://en.wikipedia.org/wiki/Term%20graph | A term graph is a representation of an expression in a formal language as a generalized graph whose vertices are . Term graphs are a more powerful form of representation than expression trees because they can represent not only common subexpressions (i.e. they can take the structure of a directed acyclic graph) but also cyclic/recursive subexpressions (cyclic digraphs).
Abstract syntax trees cannot represent shared subexpressions since each tree node can only have one parent; this simplicity comes at the cost of efficiency due to redundant duplicate computations of identical terms. For this reason term graphs are often used as an intermediate language at a subsequent compilation stage to abstract syntax tree construction via parsing.
The phrase "term graph rewriting" is often used when discussing graph rewriting methods for transforming expressions in formal languages. Considered from the point of view of graph grammars, term graphs are not regular graphs, but hypergraphs where an n-ary word will have a particular subgraph in first place, another in second place, and so on, a distinction that does not exist in the usual undirected graphs studied in graph theory.
Term graphs are a prominent topic in programming language research since term graph rewriting rules can formally expressing a compiler's operational semantics. Term graphs are also used as abstract machines capable of modelling chemical and biological computations as well as graphical calculi such as concurrency models. Term graphs can perform automated verification and logical programming since they are well-suited to representing quantified statements in first order logic. Symbolic programming software is another application for term graphs, which are capable of representing and performing computation with abstract algebraic structures such as groups, fields and rings.
The TERMGRAPH conference focuses entirely on research into term graph rewriting and its applications.
Term graphs are also used in |
https://en.wikipedia.org/wiki/Drop.io | Drop.io was an online file sharing service. It allowed users to quickly create "drops", which could contain files of any type, and could be accessed via the internet, e-mail, phone, fax, and widgets. The service did not require users to sign up for an account, and each drop was private unless the creator chose to share it. Drop.io was named one of Time magazine's 50 Best Websites of 2009, and CNET Webware 100.
On October 29, 2010, Drop.io announced that the company had been purchased by Facebook, Inc. and that the service would be shutting down. Sam Lessin, one of the site's founders, would be moving to Facebook. , the site is no longer active; the blog is also down, as of November 2011. As of 2021, http://drop.io redirects to a site owned by Chandler Systems, Inc., an Ohio-based manufacturer of residential and commercial water treatment products.
Products
Drop.io's free product provided 100 megabytes of storage. Users could upgrade to 25 gigabytes of storage for an annual fee. Drop.io additionally offered a business and education-oriented service called Manager, which aimed to replace FTP systems for file sharing.
History
Drop.io was founded by Sam Lessin and Darshan Somashekar in August 2007. The company's offices were originally located in Manhattan, New York City; it moved to the "DUMBO" neighborhood of Brooklyn in 2008.
Drop.io was nominated for the Technical Achievement Award at the South By Southwest 11th Annual Web Awards in 2007.
On June 10, drop.io and Scribd, announced a partnership to offer rich conversion and viewing within private "drops", in an attempt to make it easier for people to share private information online. As of 2008, users can find drop.io on a number of social networking sites, including: Facebook and Twitter.
Between March 2007 and November 2008, drop.io released a series of feature improvements to their platform including 'inputs' and 'outputs' via various interfaces like phone and fax, a Twitter 'subscription' mode, and a Fi |
https://en.wikipedia.org/wiki/Ceridwen%20Fraser | Ceridwen Fraser is an Australian biogeographer, currently serving as a research associate professor for the Department of Marine Science at the University of Otago in Dunedin, New Zealand. She focuses her studies on ecology, evolution, climate change, and how they are all significant to the southern hemisphere, specifically at higher latitudes such as Antarctica.
Early life and career
Fraser was born in Canberra. While in primary school, she had a teacher who was a marine biologist and collected organisms from the ocean and displayed them in a tank in the classroom. Fraser was often distracted and amazed at these small animals, and by the age of 11, Fraser knew that she wanted to become a marine biologist. However, many adults in her life advised her that this would be a risky career choice, and therefore her first undergraduate degree was in the studies of conserving cultural materials, more specifically paper conservation, at the University of Canberra. After earning this degree, Fraser completed her second undergraduate degree in marine science at Macquarie University, after having transferred from James Cook University (because she could not handle the climate of Townsville). After graduating from Macquarie University, Fraser spent a year studying polychaete worm ecology at the Australian Museum with Pat Hutchings. She earned her PhD from the Department of Zoology at the University of Otago.
Fraser became a lecturer at the Australian National University in 2012, where she worked at and mainly conducted her research at up until 2019. In that same year, she received, and took the opportunity, to move her lab group and continue her research at the University of Otago, where she continues to be a professor.
Research
Fraser's research has expanded to several different parts of the world. After receiving her doctorate, Fraser worked at two different locations as a postdoctorate fellow. The first of these occupations was at the University of Otago with the Allan |
https://en.wikipedia.org/wiki/Zinc%20oxide | Zinc oxide is an inorganic compound with the formula . It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically.
History
Zinc compounds were probably used by early humans, in processed and unprocessed forms, as a paint or medicinal ointment, but their composition is uncertain. The use of pushpanjan, probably zinc oxide, as a salve for eyes and open wounds, is mentioned in the Indian medical text the Charaka Samhita, thought to date from 500 BC or before. Zinc oxide ointment is also mentioned by the Greek physician Dioscorides (1st century AD). Galen suggested treating ulcerating cancers with zinc oxide, as did Avicenna in his The Canon of Medicine. It is used as an ingredient in products such as baby powder and creams against diaper rashes, calamine cream, anti-dandruff shampoos, and antiseptic ointments.
The Romans produced considerable quantities of brass (an alloy of zinc and copper) as early as 200 BC by a cementation process where copper was reacted with zinc oxide. The zinc oxide is thought to have been produced by heating zinc ore in a shaft furnace. This liberated metallic zinc as a vapor, which then ascended the flue and condensed as the oxide. This process was described by Dioscorides in the 1st century AD. Zinc oxide has also been recovered from zinc mines at Zawar in India, dating from the second half of the first millennium BC.
From the 12th to the 16th century zinc and zinc oxide were recognized and produced in India using a primitive form of the direct synthesis process. From India, zinc manufacture moved to China in the 17th century. In 1743, the first European zinc |
https://en.wikipedia.org/wiki/Nunatak%20hypothesis | In biogeography, particularly phytogeography, the nunatak hypothesis about the origin of a biota in formerly glaciated areas is the idea that some or many species have survived the inhospitable period on icefree land such as nunataks. Its antithesis is the tabula rasa hypothesis, which posits that all species have immigrated into completely denuded land after the retreat of glaciers.
By the mid-20th Century, the nunatak hypothesis was widely accepted among biologists working on the floras of Greenland and Scandinavia. However, while modern geology has established the presence of ice-free areas during the last glacial maximum in both Greenland and Scandinavia, molecular techniques have revealed limited between-region genetic differentiation in many Arctic taxa, strongly suggesting a general capacity for long-distance dispersal among polar organisms. This does not directly disprove glacial survival. But it makes it less necessary as an explanation. Moreover, populations that survived on icefree land have probably in most cases been genetically flooded by postglacial immigrants. |
https://en.wikipedia.org/wiki/List%20of%20nominees%20for%20the%20Nobel%20Prize%20in%20Physics | The Nobel Prize in Physics () is awarded annually by the Royal Swedish Academy of Sciences to scientists who have made outstanding contributions in Physics. It is one of the five Nobel Prizes which were established by the will of Alfred Nobel in 1895.
Every year, the Royal Swedish Academy of Sciences sends out forms, which amount to a personal and exclusive invitation, to about three thousand selected individuals to invite them to submit nominations. The names of the nominees are never publicly announced, and neither are they told that they have been considered for the Prize. Nomination records are strictly sealed for fifty years. , the nominations for the years 1901 to 1970 are publicly available. Despite the annual sending of invitations, the prize was not awarded in six years (1916, 1931, 1934, 1940–1942) and have been delayed for a year nine times (1914, 1917, 1918, 1921, 1924, 1925, 1928, 1932, 1943).
From 1901 to 1970, 574 scientists were nominated for the prize, 92 of which were awarded either jointly or individually. 31 more scientists from these nominees were awarded after 1970 and John Bardeen was awarded a second time on 1972. Of the 10 women nominees, only two were awarded the prize. The first woman to be nominated was Marie Curie in 1902 by German scientist Emil Warburg and French mathematician Gaston Darboux, and she won the prize the next year. She is the only woman to win a Nobel Prize twice: Physics (1903) and Chemistry (1911). Besides 22 and 3 scientists from these nominees won the prizes in Chemistry (including two more women) and in Physiology or Medicine correspondingly (including years after 1970). Only one informal corporation and one organization have been nominated: the Nuclear scientists (1946 and 1947) and CERN (1970).
Despite the long list of nominated noteworthy physicists, astronomers, engineers, and chemists, there have been other famed scientists who were overlooked for the prize in physics, such as physicists G.Fr.FitzGerald, G.St |
https://en.wikipedia.org/wiki/Edge%20data%20integration | An edge data integration is an implementation of data integration technology undertaken in an ad hoc or tactical fashion. This is also sometimes referred to as point-to-point integration because it connects two types of data directly to serve a narrow purpose. Many edge integrations, and actually the vast majority of all data integration, involve hand-coded scripts. Some may take the form of Business Mashups (web application hybrids), Rich Internet applications, or other browser-based models that take advantage of Web 2.0 technologies to combine data in a Web browser.
Examples of edge data integration projects might be:
extracting a list of customers from a host Sales Force Automation application and writing the results to an Excel spreadsheet
creating a script-driven framework for managing RSS feeds
combining data from a weather Web site, a shipping company's Web site, and a company's internal logistics database to track shipments and estimated arrival times of packages
It has been claimed that edge data integration do not typically require large budgets and centrally managed technologies, which is in contrast to a core data integration.
See also
core data integration
Business Mashups
Rich Internet application
Web 2.0
Yahoo! Pipes
Microsoft Popfly
IBM Mashup Center |
https://en.wikipedia.org/wiki/Stream%20cipher | A stream cipher is a symmetric key cipher where plaintext digits are combined with a pseudorandom cipher digit stream (keystream). In a stream cipher, each plaintext digit is encrypted one at a time with the corresponding digit of the keystream, to give a digit of the ciphertext stream. Since encryption of each digit is dependent on the current state of the cipher, it is also known as state cipher. In practice, a digit is typically a bit and the combining operation is an exclusive-or (XOR).
The pseudorandom keystream is typically generated serially from a random seed value using digital shift registers. The seed value serves as the cryptographic key for decrypting the ciphertext stream. Stream ciphers represent a different approach to symmetric encryption from block ciphers. Block ciphers operate on large blocks of digits with a fixed, unvarying transformation. This distinction is not always clear-cut: in some modes of operation, a block cipher primitive is used in such a way that it acts effectively as a stream cipher. Stream ciphers typically execute at a higher speed than block ciphers and have lower hardware complexity. However, stream ciphers can be susceptible to security breaches (see stream cipher attacks); for example, when the same starting state (seed) is used twice.
Loose inspiration from the one-time pad
Stream ciphers can be viewed as approximating the action of a proven unbreakable cipher, the one-time pad (OTP). A one-time pad uses a keystream of completely random digits. The keystream is combined with the plaintext digits one at a time to form the ciphertext. This system was proved to be secure by Claude E. Shannon in 1949. However, the keystream must be generated completely at random with at least the same length as the plaintext and cannot be used more than once. This makes the system cumbersome to implement in many practical applications, and as a result the one-time pad has not been widely used, except for the most critical applications. Key g |
https://en.wikipedia.org/wiki/Kostka%20polynomial | In mathematics, Kostka polynomials, named after the mathematician Carl Kostka, are families of polynomials that generalize the Kostka numbers. They are studied primarily in algebraic combinatorics and representation theory.
The two-variable Kostka polynomials Kλμ(q, t) are known by several names including Kostka–Foulkes polynomials, Macdonald–Kostka polynomials or q,t-Kostka polynomials. Here the indices λ and μ are integer partitions and Kλμ(q, t) is polynomial in the variables q and t. Sometimes one considers single-variable versions of these polynomials that arise by setting q = 0, i.e., by considering the polynomial Kλμ(t) = Kλμ(0, t).
There are two slightly different versions of them, one called transformed Kostka polynomials.
The one-variable specializations of the Kostka polynomials can be used to relate Hall-Littlewood polynomials Pμ to Schur polynomials sλ:
These polynomials were conjectured to have non-negative integer coefficients by Foulkes, and this was later proved in 1978 by Alain Lascoux and Marcel-Paul Schützenberger.
In fact, they show that
where the sum is taken over all semi-standard Young tableaux with shape λ and weight μ.
Here, charge is a certain combinatorial statistic on semi-standard Young tableaux.
The Macdonald–Kostka polynomials can be used to relate Macdonald polynomials (also denoted by Pμ) to Schur polynomials sλ:
where
Kostka numbers are special values of the one- or two-variable Kostka polynomials:
Examples |
https://en.wikipedia.org/wiki/Weak%20stability%20boundary | Weak stability boundary (WSB), including low-energy transfer, is a concept introduced by Edward Belbruno in 1987. The concept explained how a spacecraft could change orbits using very little fuel.
Weak stability boundary is defined for the three-body problem. This problem considers the motion of a particle P of negligible mass moving with respect to two larger bodies, P1, P2, modeled as point masses, where these bodies move in circular or elliptical orbits with respect to each other, and P2 is smaller than P1.
The force between the three bodies is the classical Newtonian gravitational force. For example, P1 is the Earth, P2 is the Moon and P is a spacecraft; or P1 is the Sun, P2 is Jupiter and P is a comet, etc. This model is called the restricted three-body problem. The weak stability boundary defines a region about P2 where P is temporarily captured. This region is in position-velocity space. Capture means that the Kepler energy between P and P2 is negative. This is also called weak capture.
Background
This boundary was defined for the first time by Edward Belbruno of Princeton University in 1987. He described a Low-energy transfer which would allow a spacecraft to change orbits using very little fuel. It was for motion about Moon (P2) with P1 = Earth. It is defined algorithmically by monitoring cycling motion of P about the Moon and finding the region where cycling motion transitions between stable and unstable after one cycle. Stable motion means P can completely cycle about the Moon for one cycle relative to a reference section, starting in weak capture. P needs to return to the reference section with negative Kepler energy. Otherwise, the motion is called unstable, where P does not return to the reference section within one cycle or if it returns, it has non-negative Kepler energy.
The set of all transition points about the Moon comprises the weak stability boundary, . The motion of is sensitive or chaotic as it moves about the Moon within . A mathematic |
https://en.wikipedia.org/wiki/4 | 4 (four) is a number, numeral and digit. It is the natural number following 3 and preceding 5. It is a square number, the smallest semiprime and composite number, and is considered unlucky in many East Asian cultures.
Evolution of the Hindu-Arabic digit
Brahmic numerals represented 1, 2, and 3 with as many lines. 4 was simplified by joining its four lines into a cross that looks like the modern plus sign. The Shunga would add a horizontal line on top of the digit, and the Kshatrapa and Pallava evolved the digit to a point where the speed of writing was a secondary concern. The Arabs' 4 still had the early concept of the cross, but for the sake of efficiency, was made in one stroke by connecting the "western" end to the "northern" end; the "eastern" end was finished off with a curve. The Europeans dropped the finishing curve and gradually made the digit less cursive, ending up with a digit very close to the original Brahmin cross.
While the shape of the character for the digit 4 has an ascender in most modern typefaces, in typefaces with text figures the glyph usually has a descender, as, for example, in .
On the seven-segment displays of pocket calculators and digital watches, as well as certain optical character recognition fonts, 4 is seen with an open top: .
Television stations that operate on channel 4 have occasionally made use of another variation of the "open 4", with the open portion being on the side, rather than the top. This version resembles the Canadian Aboriginal syllabics letter ᔦ. The magnetic ink character recognition "CMC-7" font also uses this variety of "4".
Mathematics
Four is the smallest composite number, its proper divisors being and . Four is the sum and product of two with itself: , the only number such that , which also makes four the smallest and only even squared prime number and hence the first squared prime of the form , where is a prime. Four, as the first composite number, has a prime aliquot sum of 3; and as such it is pa |
https://en.wikipedia.org/wiki/Van%20der%20Corput%20lemma%20%28harmonic%20analysis%29 | In mathematics, in the field of harmonic analysis,
the van der Corput lemma is an estimate for oscillatory integrals
named after the Dutch mathematician J. G. van der Corput.
The following result is stated by E. Stein:
Suppose that a real-valued function is smooth in an open interval ,
and that for all .
Assume that either , or that
and is monotone for .
Then there is a constant , which does not depend on ,
such that
for any .
Sublevel set estimates
The van der Corput lemma is closely related to the sublevel set estimates,
which give the upper bound on the measure of the set
where a function takes values not larger than .
Suppose that a real-valued function is smooth
on a finite or infinite interval ,
and that for all .
There is a constant , which does not depend on ,
such that
for any
the measure of the sublevel set
is bounded by . |
https://en.wikipedia.org/wiki/Futile%20cycle | A futile cycle, also known as a substrate cycle, occurs when two metabolic pathways run simultaneously in opposite directions and have no overall effect other than to dissipate energy in the form of heat. The reason this cycle was called "futile" cycle was because it appeared that this cycle operated with no net utility for the organism. As such, it was thought of being a quirk of the metabolism and thus named a futile cycle. After further investigation it was seen that futile cycles are very important for regulating the concentrations of metabolites. For example, if glycolysis and gluconeogenesis were to be active at the same time, glucose would be converted to pyruvate by glycolysis and then converted back to glucose by gluconeogenesis, with an overall consumption of ATP. Futile cycles may have a role in metabolic regulation, where a futile cycle would be a system oscillating between two states and very sensitive to small changes in the activity of any of the enzymes involved. The cycle does generate heat, and may be used to maintain thermal homeostasis, for example in the brown adipose tissue of young mammals, or to generate heat rapidly, for example in insect flight muscles and in hibernating animals during periodical arousal from torpor. It has been reported that the glucose metabolism substrate cycle is not a futile cycle but a regulatory process. For example, when energy is suddenly needed, ATP is replaced by AMP, a much more reactive adenine.
Example
The simultaneous carrying out of glycolysis and gluconeogenesis is an example of a futile cycle, represented by the following equation:
For example, during glycolysis, fructose-6-phosphate is converted to fructose-1,6-bisphosphate in a reaction catalysed by the enzyme phosphofructokinase 1 (PFK-1).
But during gluconeogenesis (i.e. synthesis of glucose from pyruvate and other compounds) the reverse reaction takes place, being catalyzed by fructose-1,6-bisphosphatase (FBPase-1).
Giving an overall reaction of: |
https://en.wikipedia.org/wiki/Piconet | A piconet is an ad hoc network that links a wireless user group of devices using Bluetooth technology protocols. A piconet consists of two or more devices occupying the same physical channel (synchronized to a common clock and hopping sequence). It allows one master device to interconnect with up to seven active slave devices. Up to 255 further slave devices can be inactive, or parked, which the master device can bring into active status at any time, but an active station must go into parked first.
Some examples of piconets include a cell phone connected to a computer, a laptop and a Bluetooth-enabled digital camera, or several PDAs that are connected to each other.
Overview
A group of devices are connected via Bluetooth technology in an ad hoc fashion. A piconet starts with two connected devices, and may grow to eight connected devices. Bluetooth communication always designates one of the Bluetooth devices as a main controlling unit or master unit. Other devices that follow the master unit are slave units. This allows the Bluetooth system to be non-contention based (no collisions). This means that after a Bluetooth device has been added to the piconet, each device is assigned a specific time period to transmit and they do not collide or overlap with other units operating within the same piconet.
Piconet range varies according to the class of the Bluetooth device. Data transfer rates vary between about 200 and 2100 kilobits per second.
Because the Bluetooth system hops over 79 channels, the probability of interfering with another Bluetooth system is less than 1.5%. This allows several Bluetooth piconets to operate in the same area at the same time with minimal interference.
See also
Personal area network (PAN)
Scatternet
IEEE 802.15
Further reading
Bluetooth |
https://en.wikipedia.org/wiki/Rework%20%28electronics%29 | Rework (or re-work) is the term for the refinishing operation or repair of an electronic printed circuit board (PCB) assembly, usually involving desoldering and re-soldering of surface-mounted electronic components (SMD). Mass processing techniques are not applicable to single device repair or replacement, and specialized manual techniques by expert personnel using appropriate equipment are required to replace defective components; area array packages such as ball grid array (BGA) devices particularly require expertise and appropriate tools. A hot air gun or hot air station is used to heat devices and melt solder, and specialised tools are used to pick up and position often tiny components.
A rework station is a place to do this work—the tools and supplies for this work, typically on a workbench. Other kinds of rework require other tools.
Reasons for rework
Rework is practiced in many kinds of manufacturing when defective products are found.
For electronics, defects may include:
Poor solder joints because of faulty assembly or thermal cycling.
Solder bridges—unwanted drops of solder that connect points that should be isolated from each other.
Faulty components.
Engineering parts changes, upgrades, etc.
Components broken due to natural wear, physical stress or excessive current.
Components damaged due to liquid ingress, leading to corrosion, weak solder joints or physical damage.
Process
The rework may involve several components, which must be worked on one by one without damage to surrounding parts or the PCB itself. All parts not being worked on are protected from heat and damage. Thermal stress on the electronic assembly is kept as low as possible to prevent unnecessary contractions of the board which might cause immediate or future damage.
In the 21st century, almost all soldering is carried out with lead-free solder, both on manufactured assemblies and in rework, to avoid the health and environmental hazards of lead. Where this precaution is not n |
https://en.wikipedia.org/wiki/Named%20data%20networking | Named Data Networking (NDN) (related to content-centric networking (CCN), content-based networking, data-oriented networking or information-centric networking (ICN)) is a proposed Future Internet architecture inspired by years of empirical research into network usage and a growing awareness of unsolved problems in contemporary internet architectures like IP. NDN has its roots in an earlier project, Content-Centric Networking (CCN), which Van Jacobson first publicly presented in 2006. The NDN project is investigating Jacobson's proposed evolution from today's host-centric network architecture IP to a data-centric network architecture (NDN). The belief is that this conceptually simple shift will have far-reaching implications for how people design, develop, deploy, and use networks and applications.
NDN has three core concepts that distinguish NDN from other network architectures. First, applications name data and data names will directly be used in network packet forwarding; consumer applications request desired data by its name, so communications in NDN are consumer-driven. Second, NDN communications are secured in a data-centric manner, that is, each piece of data (called a Data packet) will be cryptographically signed by its producer and sensitive payload or name components can also be encrypted for the purpose of privacy; in this way, consumers can verify the packet regardless of how the packet is fetched. Third, NDN adopts a stateful forwarding plane where forwarders will keep a state for each data request (called an Interest packet) and erase the state when a corresponding Data packet comes back; NDN's stateful forwarding allows intelligent forwarding strategies and eliminates loops.
Its premise is that the Internet is primarily used as an information distribution network, which is not a good match for IP, and that the future Internet's "thin waist" should be based on named data rather than numerically addressed hosts. The underlying principle is that a comm |
https://en.wikipedia.org/wiki/Cornus%20canadensis | Cornus canadensis is a species of flowering plant in the dogwood family Cornaceae, native to eastern Asia and North America. Common names include Canadian dwarf cornel, Canadian bunchberry, quatre-temps, crackerberry, and creeping dogwood. Unlike its relatives, which are for the most part substantial trees and shrubs, C. canadensis is a creeping, rhizomatous perennial growing to about tall.
Description
Cornus canadensis is a slow-growing herbaceous perennial growing tall, generally forming a carpet-like mat. The above-ground shoots rise from slender creeping rhizomes that are placed deep in the soil, and form clonal colonies under trees. The vertically produced above-ground stems are slender and unbranched. Produced near the terminal node, the leaves are shiny dark green and arranged oppositely on the stem, clustered with six leaves that often seem to be in a whorl because the internodes are compressed. The leaves consist of two types: two larger and four smaller leaves; the smaller ones develop from the axillary buds of the larger leaves. The leaves have petioles in length and leaf blades that are obovate. The blades have entire margins and are long and wide, with 2–3 veins, cuneate shaped bases and abruptly acuminate apexes. In autumn, the leaves have red-tinted veins and turn completely red.
Flowers
In late spring to midsummer, white flowers are produced that are in diameter with reflexed petals that are ovate-lanceolate in shape and long. The inflorescences are made up of compound terminal cymes, with large showy white bracts that resemble petals. The bracts are green when immature. The bracts are broadly ovate and long and wide, with 7 parallel running veins. The lower nodes on the stem have greatly reduced rudimentary leaves. The calyx tube is obovate in shape and 1 mm long, covered with densely pubescent hairs along with grayish white appressed trichomes. Stamens are very short, being 1 mm long. The anthers are yellowish white in color, narrowly |
https://en.wikipedia.org/wiki/Deltaretrovirus | Deltaretrovirus is a genus of the Retroviridae family. It consists of exogenous horizontally transmitted viruses found in several groups of mammals. , ICTV lists under this genus the Bovine leukemia virus and three species of primate T-lymphotropic virus.
The genus of viruses is known for its propensity to target immune cells and oncogenity, evident in the names of the four named species. Infection is usually asymptomatic, but inflammation and cancer can develop over time.
Classification
Four species are recognized by the ICTV as of 2023:
Bovine leukemia virus
Primate T-lymphotropic virus 1
Primate T-lymphotropic virus 2
Primate T-lymphotropic virus 3
Two additional PTLVs are known but not regonized: HTLV-4 (South Cameroon, 2005) and STLV-5 (Mac B43 strain, highly divergent PTLV-1).
In addition, eight endogenous retroviruses identified as Deltaretrovirus are known as of 2019. Two of these were complete enough to show ORFs; the rest only showing long terminal repeats.
Hosts
Known exogenous deltaretroviruses infect cattle and primates.
The two complete endogenous ones were found in bats and dolphins; the others in Solenodon, mongoose, and fossa. These endogenous examples fill in the large gap in the host range.
Clinical relevance |
https://en.wikipedia.org/wiki/Sznajd%20model | The Sznajd model or United we stand, divided we fall (USDF) model is a sociophysics model introduced in 2000 to gain fundamental understanding about opinion dynamics. The Sznajd model implements a phenomenon called social validation and thus extends the Ising spin model. In simple words, the model states:
Social validation: If two people share the same opinion, their neighbors will start to agree with them.
Discord destroys: If a block of adjacent persons disagree, their neighbors start to argue with them.
Mathematical formulation
For simplicity, one assumes that each individual has
an opinion Si which might be Boolean ( for no, for yes) in its simplest formulation, which means that each individual either agrees or disagrees to a given question.
In the original 1D-formulation, each individual has exactly two neighbors just like beads on a bracelet. At each time step a pair of individual and is chosen at random to change their nearest neighbors' opinion (or: Ising spins) and according to two dynamical rules:
If then and . This models social validation, if two people share the same opinion, their neighbors will change their opinion.
If then and . Intuitively: If the given pair of people disagrees, both adopt the opinion of their other neighbor.
Findings for the original formulations
In a closed (1 dimensional) community, two steady states are always reached, namely complete consensus (which is called ferromagnetic state in physics) or stalemate (the antiferromagnetic state).
Furthermore, Monte Carlo simulations showed that these simple rules lead to complicated dynamics, in particular to a power law in the decision time distribution with an exponent of -1.5.
Modifications
The final (antiferromagnetic) state of alternating all-on and all-off is unrealistic to represent the behavior of a community. It would mean that the complete population uniformly changes their opinion from one time step to the next. For this reason an alternative dynamical ru |
https://en.wikipedia.org/wiki/Fiber-optic%20current%20sensor | A fiber-optic current sensor (FOCS) is a current sensor for measuring direct current. By using a single-ended optical fiber around the current conductor that utilizes the magneto-optic effect (Faraday effect), FOCS measures uni- or bidirectional DC currents of up to 600 kA within ±0.1% of the measured value.
Because it does not need a magnetic yoke, an FOCS is smaller and lighter than Hall effect current sensors, and suffers no reduction in accuracy due to saturation effects. Because magnetic field sensing is distributed around circumference, it is unaffected by stray magnetic fields, and there is no need for magnetic centering. It also does not need recalibration after installation or during its service life. Because the optical fiber is inherently insulating, electrical isolation is easier to maintain.
The optical phase detection circuit, light source and digital signal processor are contained within the sensor electronics; this technology has been proven in highly demanding applications such as navigation systems in the air, on land and at sea.
Applications
In 2013, ABB launched a 420 kV Disconnecting Circuit Breaker (DCB) with integrated FOCS. Since one FOCS replaces many conventional current transformers, engineering and design of the substation is simplified. By reducing the material needed, including insulation, a 420 kV DCB with integrated FOCS can reduce a substation's footprint by over 50% compared to the conventional solution of live tank breakers with disconnectors and current transformers. |
https://en.wikipedia.org/wiki/James%27%20space | In the area of mathematics known as functional analysis, James' space is an important example in the theory of Banach spaces and commonly serves as useful counterexample to general statements concerning the structure of general Banach spaces. The space was first introduced in 1950 in a short paper by Robert C. James.
James' space serves as an example of a space that is isometrically isomorphic to its double dual, while not being reflexive. Furthermore, James' space has a basis, while having no unconditional basis.
Definition
Let denote the family of all finite increasing sequences of integers of odd length. For any sequence of real numbers and we define the quantity
James' space, denoted by J, is defined to be all elements x from c0 satisfying
, endowed with the norm .
Properties
James' space is a Banach space.
The canonical basis {en} is a (conditional) Schauder basis for J. Furthermore, this basis is both monotone and shrinking.
J has no unconditional basis.
James' space is not reflexive. Its image into its double dual under the canonical embedding has codimension one.
James' space is however isometrically isomorphic to its double dual.
James' space is somewhat reflexive, meaning every closed infinite-dimensional subspace contains an infinite dimensional reflexive subspace. In particular, every closed infinite-dimensional subspace contains an isomorphic copy of ℓ2.
See also
Banach space
Tsirelson space |
https://en.wikipedia.org/wiki/Biochimica%20et%20Biophysica%20Acta | Biochimica et Biophysica Acta (BBA) is a peer-reviewed scientific journal in the field of biochemistry and biophysics that was established in 1947. The journal is published by Elsevier with a total of 100 annual issues in ten specialised sections.
History
Early years
Biochimica et Biophysica Acta was first published in 1947 and was the first international journal to be devoted to the joint fields of biochemistry and biophysics. Published by Elsevier in cooperation with Interscience, it was the first international journal to be launched by Elsevier. The journal first made a profit in 1951.
Early papers were published in English, French, and German, with summaries in all three languages. The majority of papers in the first volume originated in northern and western Europe, with a minority from the US and elsewhere; contributors included William Astbury, Jean Brachet, Hubert Chantrenne, Pierre Desnuelle, Claude Fromageot, Heinz Holter, Raymond Jeener, Felix Haurowitz, Edgar Lederer, Kaj Linderstrøm-Lang, Roger Vendrely, Jean-Marie Wiame, and Ralph W.G. Wyckoff.
Important papers from these early years include "Studies on the structure of ribonucleic acids" by Boris Magasanik and Erwin Chargaff (1951), part of the evidence on which Watson and Crick's model of the structure of DNA was based, and "Enzymic synthesis of deoxyribonucleic acid" by Arthur Kornberg and colleagues (1956), an early report on the isolation of DNA polymerase I.
Diversification
Biochimica et Biophysica Acta was published as a single title until 1962, when additional sections began to be published alongside the main journal: first Specialized Section on Nucleic Acids and Related Subjects and then, from 1963, Specialized Section on Enzymological Subjects and Specialized Section on Lipids and Related Subjects.
In 1964, the main journal became Biochimica et Biophysica Acta (BBA) - General Subjects, and was published alongside the three established sections plus Specialized Section on Biophysical Su |
https://en.wikipedia.org/wiki/Orphan%20gene | Orphan genes, ORFans, or taxonomically restricted genes (TRGs) are genes that lack a detectable homologue outside of a given species or lineage. Most genes have known homologues. Two genes are homologous when they share an evolutionary history, and the study of groups of homologous genes allows for an understanding of their evolutionary history and divergence. Common mechanisms that have been uncovered as sources for new genes through studies of homologues include gene duplication, exon shuffling, gene fusion and fission, etc. Studying the origins of a gene becomes more difficult when there is no evident homologue. The discovery that about 10% or more of the genes of the average microbial species is constituted by orphan genes raises questions about the evolutionary origins of different species as well as how to study and uncover the evolutionary origins of orphan genes.
In some cases, a gene can be classified as an orphan gene due to undersampling of the existing genome space. While it is possible that homologues exist for a given gene, that gene will still be classified as an orphan if the organisms harbouring homologues have not yet been discovered and had their genomes sequenced and properly annotated. For example, one study of orphan genes across 119 archaeal and bacterial genomes could identify that at least 56% were recently acquired from integrative elements (or mobile genetic elements) from non-cellular sources such as viruses and plasmids that remain to be explored and characterized, and another 7% arise through horizontal gene transfer from distant cellular sources (with an unknown proportion of the remaining 37% potentially coming from still unknown families of integrative elements). In other cases, limitations in computational methods for detecting homologues may result in missed homologous sequences and thus classification of a gene as an orphan. Homology detection failure appears to account for the majority, but not all orphan genes. In other cases, |
https://en.wikipedia.org/wiki/Monogenic%20field | In mathematics, a monogenic field is an algebraic number field K for which there exists an element a such that the ring of integers OK is the subring Z[a] of K generated by a. Then OK is a quotient of the polynomial ring Z[X] and the powers of a constitute a power integral basis.
In a monogenic field K, the field discriminant of K is equal to the discriminant of the minimal polynomial of α.
Examples
Examples of monogenic fields include:
Quadratic fields:
if with a square-free integer, then where if d ≡ 1 (mod 4) and if d ≡ 2 or 3 (mod 4).
Cyclotomic fields:
if with a root of unity, then Also the maximal real subfield is monogenic, with ring of integers .
While all quadratic fields are monogenic, already among cubic fields there are many that are not monogenic. The first example of a non-monogenic number field that was found is the cubic field generated by a root of the polynomial , due to Richard Dedekind. |
https://en.wikipedia.org/wiki/Illustris%20project | The Illustris project is an ongoing series of astrophysical simulations run by an international collaboration of scientists. The aim was to study the processes of galaxy formation and evolution in the universe with a comprehensive physical model. Early results were described in a number of publications following widespread press coverage. The project publicly released all data produced by the simulations in April, 2015. Key developers of the Illustris simulation have been Volker Springel (Max-Planck-Institut für Astrophysik) and Mark Vogelsberger (Massachusetts Institute of Technology). The Illustris simulation framework and galaxy formation model has been used for a wide range of spin-off projects, starting with Auriga and IllustrisTNG (both 2017) followed by Thesan (2021), MillenniumTNG (2022) and TNG-Cluster (to be published in 2023).
Illustris simulation
Overview
The original Illustris project was carried out by Mark Vogelsberger and collaborators as the first large-scale galaxy formation application of Volker Springel's novel Arepo code.
The Illustris project included large-scale cosmological simulations of the evolution of the universe, spanning initial conditions of the Big Bang, to the present day, 13.8 billion years later. Modeling, based on the most precise data and calculations currently available, are compared to actual findings of the observable universe in order to better understand the nature of the universe, including galaxy formation, dark matter and dark energy.
The simulation included many physical processes which are thought to be critical for galaxy formation. These include the formation of stars and the subsequent "feedback" due to supernova explosions, as well as the formation of super-massive black holes, their consumption of nearby gas, and their multiple modes of energetic feedback.
Images, videos, and other data visualizations for public distribution are available at official media page.
Computational aspects
The main Illustris simu |
https://en.wikipedia.org/wiki/DNase-Seq | DNase-seq (DNase I hypersensitive sites sequencing) is a method in molecular biology used to identify the location of regulatory regions, based on the genome-wide sequencing of regions sensitive to cleavage by DNase I. FAIRE-Seq is a successor of DNase-seq for the genome-wide identification of accessible DNA regions in the genome. Both the protocols for identifying open chromatin regions have biases depending on underlying nucleosome structure. For example, FAIRE-seq provides higher tag counts at non-promoter regions. On the other hand, DNase-seq signal is higher at promoter regions, and DNase-seq has been shown to have better sensitivity than FAIRE-seq even at non-promoter regions.
DNase-seq Footprinting
DNase-seq requires some downstream bioinformatics analyses in order to provide genome-wide DNA footprints. The computational tools proposed can be categorized in two classes: segmentation-based and site-centric approaches. Segmentation-based methods are based on the application of Hidden Markov models or sliding window methods to segment the genome into open/closed chromatin region. Examples of such methods are: HINT, Boyle method and Neph method. Site-centric methods, on the other hand, find footprints given the open chromatin profile around motif-predicted binding sites, i.e., regulatory regions predicted using DNA-protein sequence information (encoded in structures such as Position weight matrix). Examples of these methods are CENTIPEDE and Cuellar-Partida method. |
https://en.wikipedia.org/wiki/Apostolos%20Doxiadis | Apostolos K. Doxiadis (; born 1953) is a Greek writer. He is best known for his international bestsellers Uncle Petros and Goldbach's Conjecture (2000) and Logicomix (2009).
Early life
Doxiadis was born in Australia, where his father, the architect Constantinos Apostolou Doxiadis was working. Soon after his birth, the family returned to Athens, where Doxiadis grew up. Though his earliest interests were in poetry, fiction and the theatre, an intense interest in mathematics led Doxiadis to leave school at age fifteen, to attend Columbia University, in New York, from which he obtained a bachelor's degree in mathematics. He then attended the École Pratique des Hautes Études in Paris from which he got a master's degree, with a thesis on the mathematical modelling of the nervous system. His father's death and family reasons made him return to Greece in 1975, interrupting his graduate studies. In Greece, although involved for some years with the computer software industry, Doxiadis returned to his childhood and adolescence loves of theatre and the cinema, before becoming a full-time writer.
Work
Fiction in Greek
Doxiadis began to write in Greek. His first published work was A Parallel Life (Βίος Παράλληλος, 1985), a novella set in the monastic communities of 4th-century CE Egypt. His first novel, Makavettas (Μακαβέττας, 1988), recounted the adventures of a fictional power-hungry colonel at the time of the Greek military junta of 1967–1974. Written in a tongue-in-cheek imitation of Greek folk military memoirs, such as that of Yannis Makriyannis, it follows the plot of Shakespeare's Macbeth, of which the eponymous hero's name is a Hellenized form. Doxiadis next novel, Uncle Petros and Goldbach's Conjecture (Ο Θείος Πέτρος και η Εικασία του Γκόλντμπαχ, 1992), was the first long work of fiction whose plot takes place in the world of pure mathematics research. The first Greek critics did not find the mathematical themes appealing, and it received mediocre reviews, unlike Dox |
https://en.wikipedia.org/wiki/PayPay | is a Japanese company that develops electronic payment services owned by LY Corporation. It was established in 2018 as a joint venture between the SoftBank Group and Yahoo Japan through Z Holdings, their holding company. With 38 million users, PayPay is the largest Japanese mobile payment app. In October 2018, it began a QR code and bar code-based payment service, which was developed in collaboration with Paytm, an India-based payment service company.
From a smartphone app, users link their bank account and add money to their PayPay account. At the point of sale, the user makes a payment either by scanning a QR code, or by having the clerk scan a bar code on the smartphone.
2020 cybersecurity incident
PayPay server was hacked on November 28, 2020 which was originated in Brazil. As per the operator of PayPay, a server containing personal and financial information of its entire userbase was compromised. The company acknowledged that configuration flaws led to unauthorized access to information. The service operator was later notified of the incident and preventive measures were taken. |
https://en.wikipedia.org/wiki/Morquio%20syndrome | Morquio syndrome, also known as mucopolysaccharidosis type IV (MPS IV), is a rare metabolic disorder in which the body cannot process certain types of sugar molecules called glycosaminoglycans (AKA GAGs, or mucopolysaccharides). In Morquio syndrome, the specific GAG which builds up in the body is called keratan sulfate. This birth defect, which is autosomal recessive, is a type of lysosomal storage disorder. The buildup of GAGs in different parts of the body causes symptoms in many different organ systems. In the US, the incidence rate for Morquio syndrome is estimated at between 1 in 200,000 and 1 in 300,000 live births.
Signs and symptoms
Patients with Morquio syndrome appear healthy at birth. Types A and B have similar presentations, but Type B generally has milder symptoms. The age of onset is usually between 1 and 3 years of age. Morquio syndrome causes progressive changes to the skeleton of the ribs and chest, which may lead to neurological complications such as nerve compression. Patients may also have hearing loss and clouded corneas. Intelligence is usually normal unless a patient has untreated hydrocephalus.
Physical growth slows and often stops around age 8. Skeletal abnormalities include a bell-shaped chest, a flattening or curvature of the spine, shortened long bones, and dysplasia of the hips, knees, ankles, and wrists. The bones that stabilize the connection between the head and neck can be malformed (odontoid hypoplasia); in these cases, a surgical procedure called spinal cervical bone fusion can be lifesaving. Restricted breathing, joint stiffness, and heart disease are also common. Children with the more severe form of MPS IV may not live beyond their twenties or thirties.
Some additional signs and symptoms of Morquio syndrome include a short stature, scoliosis, kyphosis, hypermobile joints, knock-knees, pectus carinatum, misshapen limbs, unstable vertebrae, cord compression, hepatomegaly, hearing problems, vision problems, and heart problems. |
https://en.wikipedia.org/wiki/Histone-like%20nucleoid-structuring%20protein | Histone-like nucleoid-structuring protein (H-NS), is one of twelve nucleoid-associated proteins (NAPs) whose main function is the organization of genetic material, including the regulation of gene expression via xenogeneic silencing. H-NS is characterized by an N-terminal domain (NTD) consisting of two dimerization sites, a linker region that is unstructured and a C-terminal domain (CTD) that is responsible for DNA-binding. Though it is a small protein (15 kDa), it provides essential nucleoid compaction and regulation of genes (mainly silencing) and is highly expressed, functioning as a dimer or multimer. Change in temperature causes H-NS to be dissociated from the DNA duplex, allowing for transcription by RNA polymerase, and in specific regions lead to pathogenic cascades in enterobacteria such as Escherichia coli and the four Shigella species.
Structure
H-NS has a specific topology that allows it to condense bacterial DNA into a superhelical structure based on evidence from X-ray crystallography. The condensed superhelical structure has implicated H-NS in gene repression caused by the formation of oligomers. These oligomers form due to dimerization of two sites in the N-terminal domain of H-NS. For example, in bacterial species like Salmonella typhimurium, the NTD of H-NS contains dimerization sites in helices alpha 1, alpha 2 and alpha 3. Alpha helices 3 and 4 are then responsible for creating the superhelical structure of H-NS-DNA interactions by head to head association (Figure 2). H-NS also contains an unstructured linker region, also known as a Q-linker. The C-Terminal domain, also known as the DNA Binding Domain (DBD), shows high affinity for regions in DNA that are rich in Adenine and Thymine and present in a hook-like motif in a minor groove. The base stacking present in this AT rich region of the DNA allows for minor widening of the minor groove that is preferential for binding. Common DBD's include AACTA and TACTA regions which can appear hundreds of t |
https://en.wikipedia.org/wiki/Internet%20Gateway%20Device%20Protocol | Internet Gateway Device (IGD) Protocol is a protocol based on Universal Plug and Play (UPnP) for mapping ports in network address translation (NAT) setups, supported by some NAT-enabled routers. It is a common communications protocol for automatically configuring port forwarding, and is part of an ISO/IEC Standard rather than an Internet Engineering Task Force standard.
Usage
Applications using peer-to-peer networks, multiplayer gaming, and remote assistance programs need a way to communicate through home and business gateways. Without IGD one has to manually configure the gateway to allow traffic through, a process which is error-prone and time-consuming. Universal Plug and Play (UPnP) comes with a solution for network address translation traversal (NAT traversal) that implements IGD.
IGD makes it easy to do the following:
Add and remove port mappings
Assign lease times to mappings
Enumerate existing port mappings
Learn the public (external) IP address
The host can allow seeking for available IGDv1/IGDv2 devices with only one M-SEARCH for IGDv1 on the network via Simple Service Discovery Protocol (SSDP) which can be controlled then with the help of a network protocol such as SOAP. A discover request is sent via HTTP and port 1900 to the IPv4 multicast address 239.255.255.250 (for the IPv6 addresses see the Simple Service Discovery Protocol (SSDP)):
M-SEARCH * HTTP/1.1
HOST: 239.255.255.250:1900
MAN: "ssdp:discover"
MX: 2
ST: urn:schemas-upnp-org:device:InternetGatewayDevice:1
Security risks
Malware can exploit the IGD protocol to bring connected devices under the control of a foreign user. The Conficker worm is an example of a botnet created using this vector.
Compatibility issues
There are numerous compatibility issues due the different interpretations of the very large actually backward compatible IGDv1 and IGDv2 specifications. One of them is the UPnP IGD client integrated with current Microsoft Windows and Xbox systems with certified IGDv2 rou |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.