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History of animal testing In 1921 Otto Loewi provided the first substantial evidence that neuronal communication with target cells occurred via chemical synapses. He extracted two hearts from frogs and left them beating in an ionic bath. He stimulated the attached Vagus nerve of the first heart and observed its beating slowed. When the second heart was placed in the ionic bath of the first, it also slowed. In the 1920s, Edgar Adrian formulated the theory of neural communication that the frequency of action potentials, and not the size of the action potentials, was the basis for communicating the magnitude of the signal. His work was performed in an isolated frog nerve-muscle preparation. Adrian was awarded a Nobel Prize for his work. In the 1960s David Hubel and Torsten Wiesel demonstrated the macro columnar organization of visual areas in cats and monkeys, and provided physiological evidence for the critical period for the development of disparity sensitivity in vision (i.e.: the main cue for depth perception), and were awarded a Nobel Prize for their work. In 1996 Dolly the sheep was born, the first mammal to be cloned from an adult cell. The process by which Dolly the sheep was cloned utilized a process known as nuclear transfer applied by lead scientist Ian Wilmut. Although other scientists were not immediately able to replicate the experiment, Wilmut argued that the experiment was indeed repeatable, given a timeframe of over a year | https://en.wikipedia.org/wiki?curid=7800672 | 162,364 |
Ku band Above 10 GHz, Mie scattering takes over. The effect is a noticeable degradation, commonly known as rain fade, during heavy rain (100 mm/h). This problem can be mitigated by transmitting a higher powered signal from the satellite to compensate. Therefore, the K band satellites typically require considerably more power to transmit than the C-band satellites. Another weather-caused degradation called "snow fade" is not specific to the K band. It is due to snow or ice accumulation on a dish significantly altering its focal point. The satellite operator's Earth Station antenna requires more accurate position control when operating at K band due to its much narrower beam focus compared to C band for a dish of a given size. Position feedback accuracies are higher and the antenna may require a closed loop control system to maintain position under wind loading of the dish surface. | https://en.wikipedia.org/wiki?curid=77786 | 381,068 |
Nitrocellulose slide A nitrocellulose slide (or nitrocellulose film slide) is a glass microscope slide that is coated with nitrocellulose that is used to bind biological material, often protein, for colorimetric and fluorescence detection assays. For this purpose, a nitrocellulose slide is generally considered to be superior to glass, because it binds a great deal more protein, and protects the tertiary structure of the protein (and other biological material, i.e.: cells). Typically, nitrocellulose slides have a thin, opaque film of nitrocellulose on a standard 25mm × 75 mm glass microscope slide. The film is extremely sensitive to contact, and to foreign material; contact causes deformation and deposition of material, especially liquids. A nitrocellulose slide is different from a nitrocellulose membrane, which usually filters protein from solution (i.e.: physician's office pregnancy tests), but that it serves a similar goal: to detect the presence and/or concentration level of certain biological material. Nitrocellulose slides are used mainly in proteomics to do protein microarrays with automated systems that print the slides and record results. Microarrays of cell analytes, arrays of cell lysate, antibody microarrays, tissue printing, immunoarrays, etc. are also possible with the slide. Due to their high surface roughness, conventional white nitrocellulose films scatter and reflect large amounts of excitation and emission light during the fluorescence detection in the microarray scanner | https://en.wikipedia.org/wiki?curid=18558539 | 140,111 |
Comparison of wireless data standards A wide variety of different wireless data technologies exist, some in direct competition with one another, others designed for specific applications. Wireless technologies can be evaluated by a variety of different metrics of which some are described in this entry. Standards can be grouped as follows in increasing range order: Personal Area Network (PAN) systems are intended for short range communication between devices typically controlled by a single person. Some examples include wireless headsets for mobile phones or wireless heart rate sensors communicating with a wrist watch. Some of these technologies include standards such as ANT UWB, Bluetooth, ZigBee, and Wireless USB. Wireless Sensor Networks (WSN / WSAN) are, generically, networks of low-power, low-cost devices that interconnect wirelessly to collect, exchange, and sometimes act-on data collected from their physical environments - "sensor networks". Nodes typically connect in a star or mesh topology. While most individual nodes in a WSAN are expected to have limited range (Bluetooth, ZigBee, 6LoWPAN, etc.), particular nodes may be capable of more expansive communications (Wi-Fi, Cellular networks, etc.) and any individual WSAN can span a wide geographical range. An example of a WSAN would be a collection of sensors arranged throughout an agricultural facility to monitor soil moisture levels, report the data back to a computer in the main office for analysis and trend modeling, and maybe turn on automatic watering spigots if the level is too low | https://en.wikipedia.org/wiki?curid=8638682 | 287,677 |
Link Layer Discovery Protocol The (LLDP) is a vendor-neutral link layer protocol used by network devices for advertising their identity, capabilities, and neighbors on a local area network based on IEEE 802 technology, principally wired Ethernet. The protocol is formally referred to by the IEEE as "Station and Media Access Control Connectivity Discovery" specified in IEEE 802.1AB and IEEE 802.3 section 6 clause 79. LLDP performs functions similar to several proprietary protocols, such as Cisco Discovery Protocol, Foundry Discovery Protocol, Nortel Discovery Protocol and Link Layer Topology Discovery. Information gathered with LLDP can be stored in the device management information database (MIB) and queried with the Simple Network Management Protocol (SNMP) as specified in RFC 2922. The topology of an LLDP-enabled network can be discovered by "crawling" the hosts and querying this database. Information that may be retrieved include: The may be used as a component in network management and network monitoring applications. One such example is its use in data center bridging requirements. The (DCBX) is a discovery and capability exchange protocol that is used for conveying capabilities and configuration of the above features between neighbors to ensure consistent configuration across the network. LLDP is used to advertise power over Ethernet capabilities and requirements and negotiate power delivery. LLDP information is sent by devices from each of their interfaces at a fixed interval, in the form of an Ethernet frame | https://en.wikipedia.org/wiki?curid=4094864 | 121,333 |
Lag As such, the client has no direct control over the central game state and may only send change requests to the server, and can only update the local game state by receiving updates from the server. This need to communicate causes a delay between the clients and the server, and is the fundamental cause behind lag. While there may be numerous underlying reasons for why a player experiences lag, they can be summarized as insufficient hardware in either the client or the server, or a poor connection between the client and server. Hardware related issues cause lag due to the fundamental structure of the game architecture. Generally, games consist of a looped sequence of states, or "frames". During each frame, the game accepts user input and performs necessary calculations (AI, graphics etc.). When all processing is finished, the game will update the game state and produce an output, such as a new image on the screen and/or a packet to be sent to the server. The frequency at which frames are generated is often referred to as the frame rate. As the central game state is located on the server, the updated information must be sent from the client to the server in order to take effect. In addition, the client must receive the necessary information from the server in order to fully update the state. Generating packets to send to the server and processing the received packets can only be done as often as the client is able to update its local state | https://en.wikipedia.org/wiki?curid=20646089 | 117,569 |
Willis Carrier In 1906 Carrier discovered that "constant dew-point depression provided practically constant relative humidity," which later became known among air conditioning engineers as the "law of constant dew-point depression." On this discovery he based the design of an automatic control system, for which he filed a patent claim on May 17, 1907. was issued on February 3, 1914. On December 3, 1911, Carrier presented what is perhaps the most significant document ever prepared on air conditioning – "Rational Psychrometric Formulae" – at the annual meeting of the American Society of Mechanical Engineers. It became known as the "Magna Carta of Psychrometrics." This document tied together the concepts of relative humidity, absolute humidity, and dew-point temperature, thus making it possible to design air-conditioning systems to precisely fit the requirements at hand. With the onset of World War I in late 1914, the Buffalo Forge Company, where Carrier had been employed for 12 years, decided to confine its activities entirely to manufacturing. The result was that seven young engineers pooled together their life savings of $32,600 to form the Carrier Engineering Corporation in New York on June 26, 1915. The seven were Carrier, J. Irvine Lyle, Edward T. Murphy, L. Logan Lewis, Ernest T. Lyle, Frank Sanna, Alfred E. Stacey, Jr., and Edmund P. Heckel. The company eventually settled on Frelinghuysen Avenue in Newark, New Jersey | https://en.wikipedia.org/wiki?curid=609222 | 384,539 |
Modified Harvard architecture From a programmer's point of view, a modified Harvard processor in which instruction and data memories share an address space is usually treated as a von Neumann machine until cache coherency becomes an issue, as with self-modifying code and program loading. This can be confusing, but such issues are usually visible only to systems programmers and integrators. Other modified Harvard machines are like pure Harvard machines in this regard. The original Harvard machine, the Mark I, stored instructions on a punched paper tape and data in electro-mechanical counters. This, however, was entirely due to the limitations of technology available at the time. Today a Harvard machine such as the PIC microcontroller might use 12-bit wide flash memory for instructions, and 8-bit wide SRAM for data. In contrast, a von Neumann microcontroller such as an ARM7TDMI, or a modified Harvard ARM9 core, necessarily provides uniform access to flash memory and SRAM (as 8 bit bytes, in those cases). Outside of applications where a cacheless DSP or microcontroller is required, most modern processors have a CPU cache which partitions instruction and data. There are also processors which are Harvard machines by the most rigorous definition (that program and data memory occupy different address spaces), and are only "modified" in the weak sense that there are operations to read and/or write program memory as data | https://en.wikipedia.org/wiki?curid=12907435 | 371,391 |
Sonoporation Sonoporation, or "cellular sonication", is the use of sound (typically ultrasonic frequencies) for modifying the permeability of the cell plasma membrane. This technique is usually used in molecular biology and non-viral gene therapy in order to allow uptake of large molecules such as DNA into the cell, in a cell disruption process called transfection or transformation. employs the acoustic cavitation of microbubbles to enhance delivery of these large molecules. The bioactivity of this technique is similar to, and in some cases found superior to, electroporation. Extended exposure to low-frequency (<MHz) ultrasound has been demonstrated to result in complete cellular death (rupturing), thus cellular viability must also be accounted for when employing this technique. is under active study for the introduction of foreign genes in tissue culture cells, especially mammalian cells. is also being studied for use in targeted Gene therapy in vivo, in a medical treatment scenario whereby a patient is given modified DNA, and an ultrasonic transducer might target this modified DNA into specific regions of the patient's body. is performed with a dedicated sonoporator. may also be performed with custom-built piezoelectric transducers connected to bench-top function generators and acoustic amplifiers. Standard ultrasound medical devices may also be used in some applications | https://en.wikipedia.org/wiki?curid=20497041 | 15,995 |
FM broadcast band Hungary closed down its remaining broadcast transmitters in 2007, and for thirty days in July of that year, several Hungarian amateur radio operators received a temporary experimental permit to perform propagation and interference experiments in the 70–70.5 MHz band. In Belarus, only government-run public radio stations are still active on OIRT. All stations on OIRT in Belarus are a mirror of normal FM broadcasts. The main purpose of those stations is compatibility with older equipment. In 2014, Russia began replacing OIRT-banded transmitter with CCIR-banded (the "western") FM transmitters. The main reason for the change to CCIR FM is to reach more listeners. Unlike Western practice, OIRT FM frequencies are based on 30 kHz rather than 50, 100 or 200 kHz multiples. This may have been to reduce co-channel interference caused by Sporadic E propagation and other atmospheric effects, which occur more often at these frequencies. However, multipath distortion effects are less annoying than on the CCIR band. Stereo is generally achieved by sending the stereo difference signal, using a process called polar modulation. Polar modulation uses a reduced subcarrier on 31.25 kHz with the audio on both side-bands. This gives the following signal structure: L + R --> 31.25 kHz reduced subcarrier L - R. The 4-meter band (70–70.5 MHz) amateur radio allocation used in many European countries is entirely within the OIRT FM band | https://en.wikipedia.org/wiki?curid=272522 | 227,339 |
East Sixth Avenue Parkway is a parkway, part of the Denver Park and Parkway System, which was built in 1909. It was listed on the National Register of Historic Places in 1986. It runs from Colorado Blvd. to Quebec St. in the Hale and Montclair neighborhoods of Denver, Colorado. The listing included two contributing structures. | https://en.wikipedia.org/wiki?curid=57644869 | 316,271 |
Video production Teachers integrate best practice teaching techniques to create scripts, organize content, capture video footage, edit footage using computer based video editing software to deliver final educational material over the Internet. It differs from other types of video production in at least three ways: The primary purpose of using video in distance education is to improve understanding and comprehension in a synchronous or asynchronous manner. Webcasting is also being used in education for distance learning projects; one innovative use was the "DiveLive" programs. For example, Nautilus Productions details an exploration of a notable shipwreck: "In the fall of 2000 Rick Allen's Nautilus Productions co-produced with Bill Lovin of Marine Grafics a groundbreaking, week long live internet broadcast known as "QAR DiveLive" from the Blackbeard wreck site. For the first time ever, live video and audio was broadcast from an underwater archaeological site to the World Wide Web. Students were able to watch the underwater archaeology in real time and ask questions of the scientists exploring the shipwreck. The twice-daily live distance learning programs reached an estimated 1600 students from as far away as Canada during the five days of broadcasting. In October of 2001 Allen and Lovin again co-produced "QAR DiveLive 2001" | https://en.wikipedia.org/wiki?curid=1553972 | 195,852 |
Local number portability ) In the US, there are standards for portability defined by the FCC, the LNPA, NANPA and the ATIS which are agreed upon by all member providers to help make LNP as cost-efficient and expedient as possible while still retaining a healthy level security for all providers and in respect of the highest level of customer service. These rules, first defined in the 1st, 2nd and 3rd Reports and Orders by the FCC (publicly available at fcc.gov), are further detailed by the LNPA in order to ensure any provider can successfully port numbers to any other provider. iconectiv provides a national database called the NPAC (National Portability Administration Center) which contains the correct routing information for all ported and pooled numbers in the US and Canada. The NPAC maintains detailed documentation of the procedure common among US carriers to port numbers as described here. Providers use SS7 to route calls throughout the US/Canada network. SS7 accesses databases for various services such as CNAM, LIDB, Custom Local Area Signaling Services (CLASS) and LNP. Calls to ported numbers are completed when a customer who calls a ported number sends the dialed number to a provider's SSP (Service Switch Point), where it is identified either as a local call or not | https://en.wikipedia.org/wiki?curid=645581 | 278,760 |
Superscalar processor However even given infinitely fast dependency checking logic on an otherwise conventional superscalar CPU, if the instruction stream itself has many dependencies, this would also limit the possible speedup. Thus the degree of intrinsic parallelism in the code stream forms a second limitation. Collectively, these limits drive investigation into alternative architectural changes such as very long instruction word (VLIW), explicitly parallel instruction computing (EPIC), simultaneous multithreading (SMT), and multi-core computing. With VLIW, the burdensome task of dependency checking by hardware logic at run time is removed and delegated to the compiler. Explicitly parallel instruction computing (EPIC) is like VLIW with extra cache prefetching instructions. Simultaneous multithreading (SMT) is a technique for improving the overall efficiency of superscalar processors. SMT permits multiple independent threads of execution to better utilize the resources provided by modern processor architectures. Superscalar processors differ from multi-core processors in that the several execution units are not entire processors. A single processor is composed of finer-grained execution units such as the ALU, integer multiplier, integer shifter, FPU, etc. There may be multiple versions of each execution unit to enable execution of many instructions in parallel. This differs from a multi-core processor that concurrently processes instructions from "multiple" threads, one thread per processing unit (called "core") | https://en.wikipedia.org/wiki?curid=51702 | 380,442 |
Parsons Brinckerhoff Following the acquisition of Louis Berger Group by WSP Global in 2018 for $400 million, the operations of Louis Berger Group in the United States were merged with WSP USA's. The firm is involved in several major expansions of the public transportation system in the New York metropolitan area, including the new 7 Subway Extension, Second Avenue Subway, and Long Island Rail Road's East Side Access to Grand Central Terminal, Other current and recent projects include: the Taiwan High Speed Rail Project; the Bosphorus rail tunnel in Istanbul; The Woodrow Wilson Bridge in Washington, D.C.; an extension of the East London Line of the London Overground; and the Medupi Power Station in South Africa. Is is also involved with the redevelopment of LaGuardia Airport in New York City, New York. partnered with rival engineering firm Bechtel to build the troubled Big Dig in Boston, Massachusetts. The Big Dig, or Central Artery/Tunnel project as it was officially known, was intended to replace an elevated Interstate freeway and connecting roads with a tunnel system underneath Boston. The project was beset with bad engineering, shoddy workmanship, and the death of an automobile passenger as a poor ceiling design caused a tunnel roof section to collapse on a car in the tunnel, crushing the victim. The Big Dig was years over schedule and engineering costs to several times of Bechtel/Parsons Brinckerhoff's original estimates, from $8 Billion to in excess of $24 Billion | https://en.wikipedia.org/wiki?curid=4684743 | 215,348 |
Harry Bateman married Ethel Horner in 1912 and had a son named Harry Graham, who died as a child, later the couple adopted a daughter named Joan Margaret. He died on his way to New York in 1946 of Coronary thrombosis. In 1907 was lecturing at the University of Liverpool together with another senior wrangler, Ebenezer Cunningham. Together they came up in 1908 with the idea of a conformal group of spacetime (now usually denoted as ) which involved an extension of the method of images. For his part, in 1910 Bateman published "". He showed that the Jacobian matrix of a spacetime diffeomorphism which preserves the Maxwell equations is proportional to an orthogonal matrix, hence conformal. The transformation group of such transformations has "15 parameters" and extends both the Poincaré group and the Lorentz group. Bateman called the elements of this group spherical wave transformations. In evaluating this paper, one of his students, Clifford Truesdell, wrote Bateman was the first to apply Laplace transform to integral equation in 1906. He submitted a detailed report on integral equation in 1911 in the British association for the advancement of science. Horace Lamb in his 1910 paper solved an integral equation as a double integral, but in his footnote he says, "Mr. H. Bateman, to whom I submitted the question, has obtained a simpler solution in the form" In 1914 Bateman published "The Mathematical Analysis of Electrical and Optical Wave-motion". As Murnaghan says, this book "is unique and characteristic of the man | https://en.wikipedia.org/wiki?curid=531115 | 346,919 |
Bond softening they are accurate only for infinitely slow transitions. When the dissociation is fast and the gap is small, a diabatic transition may occur where the system ends up on the other branch of the anticrossing. The probability of such a transition is described by the Landau–Zener formula. When applied to the dissociation through the 3-photon gap, the formula gives a small probability of the H molecular ion ending up in the 3ω dissociation limit without emitting any photons. The "bond softening" phrase was coined by Phil Bucksbaum in 1990 at the time of its experimental observation. A was used to generate intense pulses of about 80 ps duration at the second harmonic of 532 nm. In a vacuum chamber, the pulses were focused on molecular hydrogen under low pressure (about 10 mbar) inducing ionization and dissociation. The kinetic energy of protons was measured in a time-of-flight (TOF) spectrometer. The proton TOF spectra revealed three peaks of kinetic energy spaced by a half of the photon energy. As the neutral H atom was taking the other half of the photon energy, this was an unambiguous confirmation of the bond softening process leading to the 1ω, 2ω and 3ω dissociation limits. Such a process which absorbs more than the minimum number of photons is known as above-threshold dissociation. A comprehensive review puts the mechanism of bond softening in a broader research context. Anticrossings of diatomic energy curves have many similarities to the conical intersections of energy surfaces in polyatomic molecules. | https://en.wikipedia.org/wiki?curid=40660830 | 28,489 |
Second-order intercept point The Second Order Intercept Point, also known as the SOI, IP2, or IIP2 (Input Intercept Point), is a measure of linearity that quantifies the second-order distortion generated by nonlinear systems and devices. Examples of frequently used devices that are concerned with this measure are amplifiers and mixers. It is related to the third-order intercept point, which is generally used for quantifying degree of nonlinearity of a nonlinear system or it can also be used to estimate the nonlinear products present at the output of such a system. At low power levels, the fundamental output power rises in a one-to-one ratio (in terms of dB) of the input power, while the second-order output power rises in a two-to-one ratio. If the input power is high enough for the device to reach saturation, the output power flattens out in both the first- and second-order cases. The second order intercept point is the output power point at which the extrapolated first- and second-order lines intersect on a plot, since the actual power levels will flatten off due to saturation at much lower power level typically. In other words, the response is assumed to be perfect all the way to infinity. There are actually values for both the input and output SOI (known as the ISOI & OSOI or IIP2 & OIP2) of a device or system, being related by the small signal gain of the device or system. The OSOI in dB is simply the ISOI in dB plus the small signal gain of the device or system | https://en.wikipedia.org/wiki?curid=17276436 | 297,954 |
Lock-in amplifier The lock-in amplifier is commonly believed to have been invented by Princeton University physicist Robert H. Dicke who founded the company Princeton Applied Research (PAR) to market the product. However, in an interview with Martin Harwit, Dicke claims that even though he is often credited with the invention of the device, he believes that he read about it in a review of scientific equipment written by Walter C. Michels, a professor at Bryn Mawr College. This could have been a 1941 article by Michels and Curtis, which in turn cites a 1934 article by C. R. Cosens, while another timeless article was written by C. A. Stutt in 1949. The operation of a lock-in amplifier relies on the orthogonality of sinusoidal functions. Specifically, when a sinusoidal function of frequency "f" is multiplied by another sinusoidal function of frequency "f" not equal to "f" and integrated over a time much longer than the period of the two functions, the result is zero. Instead, when "f" is equal to "f" and the two functions are in phase, the average value is equal to half of the product of the amplitudes. In essence, a lock-in amplifier takes the input signal, multiplies it by the reference signal (either provided from the internal oscillator or an external source), and integrates it over a specified time, usually on the order of milliseconds to a few seconds. The resulting signal is a DC signal, where the contribution from any signal that is not at the same frequency as the reference signal is attenuated close to zero | https://en.wikipedia.org/wiki?curid=1859768 | 411,704 |
OpenChrom After successful commercialization of contract development and services around the project, vendor Lablicate reinforced the commitment to Free/Libre/Open-Source Software with the release of ChemClipse in October 2016, which serves as the base for all products. The Lablicate Team is integrated into the mass spectrometry department of the University of Hamburg. They provide their chemometric knowledge for students and researchers. Each system vendor stores the recorded analysis data in its own proprietary format. That makes it difficult to compare data sets from different systems and vendors. Furthermore, it's a big drawback for interlaboratory tests. The aim of is to support a wide range of different mass spectrometry data formats natively. takes care that the raw data files can't be modified according to the good laboratory practice. To help scientists supports several open formats to import and export the analysis results. In addition, offers its own open source format (*.ocb) that makes it possible to save the edited chromatogram as well as the peaks and identification results. offers a variety of features to analyze chromatographic data: The software was first released in 2010. Each release is named after a famous scientist. | https://en.wikipedia.org/wiki?curid=28242998 | 177,764 |
Thyristor The GTO thyristor and IGCT are two devices related to the thyristor that address this problem. In high-frequency applications, thyristors are poor candidates due to long switching times arising from bipolar conduction. MOSFETs, on the other hand, have much faster switching capability because of their unipolar conduction (only majority carriers carry the current). manufacturers generally specify a region of safe firing defining acceptable levels of voltage and current for a given operating temperature. The boundary of this region is partly determined by the requirement that the maximum permissible gate power (P), specified for a given trigger pulse duration, is not exceeded. As well as the usual failure modes due to exceeding voltage, current or power ratings, thyristors have their own particular modes of failure, including: In recent years, some manufacturers have developed thyristors using silicon carbide (SiC) as the semiconductor material. These have applications in high temperature environments, being capable of operating at temperatures up to 350 °C. A reverse conducting thyristor (RCT) has an integrated reverse diode, so is not capable of reverse blocking. These devices are advantageous where a reverse or freewheel diode must be used. Because the SCR and diode never conduct at the same time they do not produce heat simultaneously and can easily be integrated and cooled together. Reverse conducting thyristors are often used in frequency changers and inverters. Photothyristors are activated by light | https://en.wikipedia.org/wiki?curid=181174 | 394,436 |
Survival of the fittest Darwin wrote on page 6 of "The Variation of Animals and Plants under Domestication" published in 1868, "This preservation, during the battle for life, of varieties which possess any advantage in structure, constitution, or instinct, I have called Natural Selection; and Mr. Herbert Spencer has well expressed the same idea by the Survival of the Fittest. The term "natural selection" is in some respects a bad one, as it seems to imply conscious choice; but this will be disregarded after a little familiarity". He defended his analogy as similar to language used in chemistry, and to astronomers depicting the "attraction of gravity as ruling the movements of the planets", or the way in which "agriculturists speak of man making domestic races by his power of selection". He had "often personified the word Nature; for I have found it difficult to avoid this ambiguity; but I mean by nature only the aggregate action and product of many natural laws,—and by laws only the ascertained sequence of events." In the first four editions of "On the Origin of Species", Darwin had used the phrase "natural selection". In Chapter 4 of the 5th edition of "The Origin" published in 1869, Darwin implies again the synonym: "Natural Selection, or the Survival of the Fittest". By "fittest" Darwin meant "better adapted for the immediate, local environment", not the common modern meaning of "in the best physical shape" (think of a puzzle piece, not an athlete) | https://en.wikipedia.org/wiki?curid=627964 | 142,435 |
History of the oil shale industry The oil shale industry expanded immediately before World War I because of limited access to conventional petroleum resources and the mass production of automobiles and trucks, which accompanied an increase in gasoline consumption. Oil shale production in Scotland peaked in 1910–1912 with more than three million tonnes. That time Scottish shale oil industry contributed 2% of global oil production. After that, production declined with exception of the period of World War II. In 1919, five survived shale oil companies ("Young's Paraffin Light & Mineral Oil Company", "Broxburn Oil Company", "Pumpherston Shale Oil Company", "Oakbank Oil Company", and "James Ross & Company Philpstoun Oil Works"), were merged into Scottish Oils, a subsidiary of Anglo-Persian Oil Company. In the United States the government started to create the Naval Petroleum and Oil Shale Reserves in 1909. The reserves were seen as a possible emergency source of fuel for the military, particularly the Navy. The government reserved the Roan Plateau near Rifle, Colorado which later became a federal demonstration and test site. First attempt to produce oil from the western deposits was made in Nevada by local businessman Robert Catlin by acquiring oil-shale properties in the 1890s and erecting the first retorts in 1915 and 1916. Although the attempt was commercially unsuccessful, in 1917 he incorporated Catlin Shale Products Company which made several unsuccessful attempts to sold shale oil products until it was dissolved in 1930 | https://en.wikipedia.org/wiki?curid=12825955 | 258,330 |
Drain-waste-vent system To allow only one vent stack, and thus one roof penetration as permitted by local building code, sub-vents may be tied together inside the building and exit via a common vent stack. One additional requirement for a vent stack connection occurs when there are very long horizontal drain runs with very little slope to the run. Adding a vent connection within the run will aid flow, and when used with a cleanout allows for better serviceability of the long run. A blocked vent is a relatively common problem caused by anything from leaves, to dead animals, to ice dams in very cold weather, or a horizontal section of the venting system, sloped the wrong way and filled with water from rain or condensation. Symptoms range from bubbles in the toilet bowl when it is flushed, to slow drainage, and all the way to siphoned (empty) traps which allow sewer gases to enter the building. When a fixture trap is venting properly, a "sucking" sound can often be heard as the fixture vigorously empties out during normal operation. This phenomenon is harmless, and is different from "trap suckout" induced by pressure variations caused by wastewater movement "elsewhere" in the system, which is not supposed to allow interactions from one fixture to another. Toilets are a special case, since they are usually designed to self-siphon to ensure complete evacuation of their contents; they are then automatically refilled by a special valve mechanism | https://en.wikipedia.org/wiki?curid=822294 | 310,087 |
United States Military Academy From this amount, pay is automatically deducted for the cost of uniforms, books, supplies, services, meals, and other miscellaneous expenses. All remaining money after deductions is used by the individual cadets’ discretion. All cadets receive meals in the dining halls, and have access to internet on approved, issued devices. The student population was 4,389 cadets for the 2016–2017 academic year. The student body has recently been around 20% female. All cadets reside on campus for their entire four years in one of the nine barracks buildings. Most cadets are housed with one roommate, but some rooms are designed for three cadets. Cadets are grouped into "companies" identified by alpha-numeric codes. All companies live together in the same barracks area. The commandant may decide to have cadets change companies at some point in their cadet career. This process is known as scrambling and the method of scrambling has changed several times in recent years. All 4,000 cadets dine together at breakfast and lunch in the Washington Hall during the weekdays. The cadet fitness center, Arvin Cadet Physical Development Center (usually just called "Arvin" by cadets and faculty), which was rebuilt in 2004, houses extensive physical fitness facilities and equipment for student use. Each class of cadets elects representatives to serve as class president and fill several administrative positions | https://en.wikipedia.org/wiki?curid=32173 | 330,935 |
Casting (metalworking) The above cooling curve depicts a basic situation with a pure metal, however, most castings are of alloys, which have a cooling curve shaped as shown below. Note that there is no longer a thermal arrest, instead there is a freezing range. The freezing range corresponds directly to the liquidus and solidus found on the phase diagram for the specific alloy. The local solidification time can be calculated using Chvorinov's rule, which is: Where "t" is the solidification time, "V" is the volume of the casting, "A" is the surface area of the casting that contacts the mold, "n" is a constant, and "B" is the mold constant. It is most useful in determining if a riser will solidify before the casting, because if the riser does solidify first then it is worthless. The gating system serves many purposes, the most important being conveying the liquid material to the mold, but also controlling shrinkage, the speed of the liquid, turbulence, and trapping dross. The gates are usually attached to the thickest part of the casting to assist in controlling shrinkage. In especially large castings multiple gates or runners may be required to introduce metal to more than one point in the mold cavity. The speed of the material is important because if the material is traveling too slowly it can cool before completely filling, leading to misruns and cold shuts. If the material is moving too fast then the liquid material can erode the mold and contaminate the final casting | https://en.wikipedia.org/wiki?curid=53601 | 58,586 |
Sabayil Castle is a submerged medieval fortress on the coast of the Caspian Sea near Baku, Azerbaijan. The castle is named after the surrounding area of Bayil. The structure is also known as the "Atlantis of the Caspian Sea". Research scientists have referred to it as “Sabayil castle”, “Bayil castle”, “Bandargala”, “Underground town”, “Caravanserai”, “Cloister”, “Monastery”, “Custom house” and “Defence castle”. The castle was built on one of the Bayil hills near the Caspian Sea coast in 1232–33, during the life of Fariburz, son of Shirvanshah Garsasb, by architect Abdul-Majid Masud oglu. At the same time, in 1232, this architect also built the round castle in Mardakan, which was part of Abseron’s integrated defence system, defending the city and Bayil Castle from the north. Some archaeologists suggested the castle belonged to the Shirvanshahs. During a major earthquake in the capital city of Baku in 1306, the building collapsed and the island submerged and remained under water for several centuries. It was not until the early 18th century, when the Caspian Sea receded, that the structure resurfaced. At this time, stones recovered from the site with inscriptions on them provided valuable information for historians. According to Azerbaijani historian Sara Ashurbeyli, Sabayil is the castle mentioned by Abdurrashid Al-Bakuvi, a 15th-century geographer who alleged that the structure was destroyed during the 13th-century Mongol invasion | https://en.wikipedia.org/wiki?curid=29461386 | 353,397 |
Sonification A blind reader could hold a book up to the device and hold an apparatus to the area she wanted to read. The optophone played a set group of notes: g c' d' e' g' b' c<nowiki>" e"</nowiki>. Each note corresponded with a position on the optophone's reading area, and that note was silenced if black ink was sensed. Thus, the missing notes indicated the positions where black ink was on the page and could be used to read. Pollack and Ficks published the first perceptual experiments on the transmission of information via auditory display in 1954. They experimented with combining sound dimensions such as timing, frequency, loudness, duration, and spacialization and found that they could get subjects to register changes in multiple dimensions at once. These experiments did not get into much more detail than that, since each dimension had only two possible values. John M. Chambers, Max Mathews, and F.R. Moore at Bell Laboratories did the earliest work on auditory graphing in their "Auditory Data Inspection" technical memorandum in 1974. They augmented a scatterplot using sounds that varied along frequency, spectral content, and amplitude modulation dimensions to use in classification. They did not do any formal assessment of the effectiveness of these experiments | https://en.wikipedia.org/wiki?curid=702705 | 384,901 |
Coal pollution mitigation The facility captures CO and acid rain producing pollutants, separates them, and compresses the CO into a liquid. Plans are to inject the CO into depleted natural gas fields or other geological formations. Vattenfall opines that this technology is considered not to be a final solution for CO reduction in the atmosphere, but provides an achievable solution in the near term while more desirable alternative solutions to power generation can be made economically practical. Other examples of oxy-combustion carbon capture are in progress. Callide Power Station has retrofitted a 30-MWth existing PC-fired power plant to operate in oxy-fuel mode; in Ciuden, Spain, Endesa has a newly built 30-MWth oxy-fuel plant using circulating fluidized bed combustion (CFBC) technology. Babcock-ThermoEnergy's Zero Emission Boiler System (ZEBS) is oxy-combustion-based; this system features near 100% carbon-capture and according to company information virtually no air-emissions. Other carbon capture and storage technologies include those that dewater low-rank coals. Low-rank coals often contain a higher level of moisture content which contains a lower energy content per tonne. This causes a reduced burning efficiency and an increased emissions output. Reduction of moisture from the coal prior to combustion can reduce emissions by up to 50 percent. In the late 1980s and early 1990s, the U.S | https://en.wikipedia.org/wiki?curid=2423894 | 345,660 |
Staining The usual purpose is to reveal cytological details that might otherwise not be apparent; however, staining can also reveal where certain chemicals or specific chemical reactions are taking place within cells or tissues. "In vitro" staining involves colouring cells or structures that have been removed from their biological context. Certain stains are often combined to reveal more details and features than a single stain alone. Combined with specific protocols for fixation and sample preparation, scientists and physicians can use these standard techniques as consistent, repeatable diagnostic tools. A counterstain is stain that makes cells or structures more visible, when not completely visible with the principal stain. While ex vivo, many cells continue to live and metabolize until they are "fixed". Some staining methods are based on this property. Those stains excluded by the living cells but taken up by the already dead cells are called vital stains (e.g. trypan blue or propidium iodide for eukaryotic cells). Those that enter and stain living cells are called supravital stains (e.g. New Methylene Blue and brilliant cresyl blue for reticulocyte staining). However, these stains are eventually toxic to the organism, some more so than others. Partly due to their toxic interaction inside a living cell, when supravital stains enter a living cell, they might produce a characteristic pattern of staining different from the staining of an already fixed cell (e.g. "reticulocyte" look versus diffuse "polychromasia") | https://en.wikipedia.org/wiki?curid=411782 | 174,534 |
Tyranny of numbers Even a single bad component or solder joint could render the entire module inoperative. Even with properly working modules, the mass of wiring connecting them together was another source of construction and reliability problems. As computers grew in complexity, and the number of modules increased, the complexity of making a machine actually work grew more and more difficult. This was the "tyranny of numbers". It was precisely this problem that Jack Kilby was thinking about while working at Texas Instruments. Theorizing that germanium could be used to make all common electronic components - resistors, capacitors, etc. - he set about building a single-slab component that combined the functionality of an entire module. Although successful in this goal, it was Robert Noyce's silicon version and the associated fabrication techniques that make the integrated circuit (IC) truly practical. Unlike modules, ICs were built using photoetching techniques on an assembly line, greatly reducing their cost. Although any given IC might have the same chance of working or not working as a module, they cost so little that if they didn't work you simply threw it away and tried another. In fact, early IC assembly lines had failure rates around 90% or greater, which kept their prices high. The U.S. Air Force and NASA were major purchasers of early ICs, where their small size and light weight overcame any cost issues | https://en.wikipedia.org/wiki?curid=995862 | 217,413 |
Enrique Ros Enrique Emilio Ros y Pérez (1924 – April 10, 2013) was a Cuban-American businessman, author, and activist opposed to Cuban president Fidel Castro. was born in 1924 in Cienfuegos, Cuba. Ros hosted radio shows on U.S. government station Radio y Televisión Martí, which broadcasts exclusively to Cuba. He was a strong advocate of retaining the United States embargo against Cuba. He was the author of "Revolucion de 1933 en Cuba". Ros was married to Amanda Adato (1926–2011) and they had two children, Enrique Jr. "Henry" and retired U.S. Representative Ileana Ros-Lehtinen, and four grandchildren: Jennifer and Katherine Ros, and Patricia and Rodrigo Lehtinen. Ros died on April 10, 2013 in a South Miami, Florida hospital from respiratory complications. He was 89. | https://en.wikipedia.org/wiki?curid=2867645 | 478,386 |
Charles Darwin When organising his notes as the ship sailed home, Darwin wrote that, if his growing suspicions about the mockingbirds, the tortoises and the Falkland Islands fox were correct, "such facts undermine the stability of Species", then cautiously added "would" before "undermine". He later wrote that such facts "seemed to me to throw some light on the origin of species". By the time Darwin returned to England, he was already a celebrity in scientific circles as in December 1835 Henslow had fostered his former pupil's reputation by giving selected naturalists a pamphlet of Darwin's geological letters. On 2 October 1836 the ship anchored at Falmouth, Cornwall. Darwin promptly made the long coach journey to Shrewsbury to visit his home and see relatives. He then hurried to Cambridge to see Henslow, who advised him on finding naturalists available to catalogue Darwin's animal collections and who agreed to take on the botanical specimens. Darwin's father organised investments, enabling his son to be a self-funded gentleman scientist, and an excited Darwin went round the London institutions being fêted and seeking experts to describe the collections. British zoologists at the time had a huge backlog of work due to natural history collecting being promoted and encouraged through the British Empire, and there was a danger of specimens just being left in storage | https://en.wikipedia.org/wiki?curid=8145410 | 162,625 |
Neurophysins are carrier proteins which transport the hormones oxytocin and vasopressin to the posterior pituitary from the paraventricular and supraoptic nucleus of the hypothalamus, respectively. Inside the neurosecretory granules, the analogous neurophysin I and II form stabilizing complexes via covalent interactions. Stabilizing neurophysin-hormone complexes that are formed within neurosecretory granules located in the posterior pituitary gland aid in intra-axonal transport. During intra-axonal transport, the neurophysin's are believed to prevent the bound hormone from leaking into the cytoplasmic space and proteolytic digestion via enzymes. However, due to the low concentration of neurophysin in the blood, it's likely the protein-hormone complex dissociates, indicating the neurophysin does not aid in transporting the hormone through the circulatory system . are also secreted out of the posterior pituitary hypothalamus, each carrying their respective associated passenger hormone. When the posterior pituitary hypothalamus secretes vasopressin and its neurophysin carrier, it also secretes a glycopeptide. There are two types: These proteins are synthesized in the cell bodies of the supraoptic and paraventricular regions of the hypothalamus. The disulfide-rich neurophysin protein is suggested to be congruent with the synthesis of insulin in which a precursor molecule of higher molecular weight is proteolytically cleaved and forms disulfide linkages | https://en.wikipedia.org/wiki?curid=5532777 | 192,507 |
Offshore oil spill prevention and response Each section is suspended by a threaded adapter inside the bottom end of the section above. Failure of either the casings or the cement can lead to injection of oil into groundwater layers, flow to the surface far from the well, or a blowout at the wellhead. In addition to casings, oil wells usually contain a "production liner" or "production tubing", which is another set of steel pipes suspended inside the casing. The "annulus" between the casing and the production liner is filled with "mud" of a specific density to "balance" the pressure inside the casing with the "pore pressure" of fluids in the surrounding rock "formations". To ensure that the cement forms a strong, continuous, 360-degree seal between the casing and the borehole, "centralizers" are placed around the casing sections before they are lowered into the borehole. Cement is then injected in the space between the bottom of the new casing section and the bottom of the borehole. The cement flows up around the outside of the casing, replacing the mud in that space with pure, uncontaminated cement. Then the cement is held perfectly still for several hours while it solidifies. Without centralizers, there is a high risk that a channel of drilling mud or contaminated cement will be left where the casing contacts the borehole. These channels can provide a path for a later blowout. Even a thin crack can be pushed open by the enormous pressure of oil from below. Then erosion of the cement can occur from high-velocity sand particles in the oil | https://en.wikipedia.org/wiki?curid=27663682 | 229,062 |
Building officials of developed countries are generally the jurisdictional administrator of building and construction codes, engineering calculation supervision, permits, facilities management, and accepted construction procedures. In some jurisdictions building officials act as project engineer or project manager for the chief building official who is the jurisdiction's formally recognized building official. Usual qualifications are a bachelor's degree in Administration, Engineering, or Architecture, or Building Surveying or Construction Management, with an extensive building construction background, and in some instances are licensed as a Professional Engineer or Architect or Building Surveyors or Building Certifiers. can be certified. Law Australian law is governed under individual state laws & territories generally made from state Acts & Regulations governing ... Qld, NSW, Vic, Tas, South Aust, West Aust, Nth Territory, Aust Capital Territory, various off shore islands & Aust protectorates within the 200 nautical mile limit of the Commonwealth of Australia. Town Planning & Development Concepts of planning & development are primarily approved under state Town Planning Acts & Regulations, which outline the procedures & protocols for various types of projects. Town Planning is a separate university degree discipline, which is usually guided by the interest of the general community & attempts to solve development problems | https://en.wikipedia.org/wiki?curid=8066154 | 356,774 |
Primer (molecular biology) A primer that can bind to multiple regions along the DNA will amplify them all, eliminating the purpose of PCR. A few criteria must be brought into consideration when designing a pair of PCR primers. Pairs of primers should have similar melting temperatures since annealing during PCR occurs for both strands simultaneously, and this shared melting temperature must not be either too much higher or lower than the reaction's annealing temperature. A primer with a "T" (melting temperature) too much higher than the reaction's annealing temperature may mishybridize and extend at an incorrect location along the DNA sequence. A "T" significantly lower than the annealing temperature may fail to anneal and extend at all. Additionally, primer sequences need to be chosen to uniquely select for a region of DNA, avoiding the possibility of hybridization to a similar sequence nearby. A commonly used method for selecting a primer site is BLAST search, whereby all the possible regions to which a primer may bind can be seen. Both the nucleotide sequence as well as the primer itself can be BLAST searched. The free NCBI tool Primer-BLAST integrates primer design and BLAST search into one application, as do commercial software products such as ePrime and Beacon Designer. Computer simulations of theoretical PCR results (Electronic PCR) may be performed to assist in primer design by giving melting and annealing temperatures, etc | https://en.wikipedia.org/wiki?curid=23650 | 154,350 |
Synonym (taxonomy) An example is the genus "Pomatia" Beck, 1837, which was established for a group of terrestrial snails containing as its type species the Burgundy or Roman snail "Helix pomatia"—since "Helix pomatia" was already the type species for the genus "Helix" Linnaeus, 1758, the genus "Pomatia" was an objective synonym (and useless). At the same occasion "Helix" is also a synonym of "Pomatia", but it is older and so it has precedence. At the species level, subjective synonyms are common because of an unexpectedly large range of variation in a species, or simple ignorance about an earlier description, may lead a biologist to describe a newly discovered specimen as a new species. A common reason for objective synonyms at this level is the creation of a replacement name. It is possible for a junior synonym to be given precedence over a senior synonym, primarily when the senior name has not been used since 1899, and the junior name is in common use. The older name may be declared to be a "nomen oblitum", and the junior name declared a "nomen protectum". This rule exists primarily to prevent the confusion that would result if a well-known name, with a large accompanying body of literature, were to be replaced by a completely unfamiliar name. An example is the European land snail "Petasina edentula" (Draparnaud, 1805) | https://en.wikipedia.org/wiki?curid=8166296 | 162,703 |
Import substitution industrialization 10 of 1965 reinforced this view, claiming that ‘If Africanization is undertaken at the expense of growth, our reward will be a falling standard of living’. Under such a development path, multinational corporations occupied a dominant role in the economy, primarily in the manufacturing sectors. Economic historians such as Ralph Austen argue that the openness to western enterprise and technical expertise led to higher GNP in Kenya than comparative Socialist countries such as Ghana and Tanzania. However, The 1972 World Bank ILO Report on Kenya, claimed that direct state intervention was necessary to reduce the growing economic inequalities that had occurred as a result of state capitalism. In all countries that adopted ISI, the state oversaw and managed its implementation, designing economic policies that directed development towards the indigenous population, with the aim of creating an industrialised economy. The 1972 Nigerian Enterprises Promotion Decree exemplifies such control, as it required foreign companies to offer at least 40% of their equity shares to local people. A state-controlled economy has been critiqued by scholars such as Douglas North, who claim that the interests of political elites may be self-serving, rather than for the good of the nation. This correlates with the theory of neo-patrimonialism, which claims that post-colonial elites used the coercive powers of the state to maintain their political positions and increase their personal wealth | https://en.wikipedia.org/wiki?curid=140763 | 507,352 |
RAMS is an acronym for Reliability, Availability, Maintainability, and Safety, commonly used in engineering to characterize a product or system: | https://en.wikipedia.org/wiki?curid=26789010 | 228,486 |
Progeria Lamin A does not appear to be necessary for life; mice in which the "Lmna" gene is knocked out show no embryological symptoms (they develop an Emery–Dreifuss muscular dystrophy-like condition postnatally). This implies that it is the buildup of prelamin A in the wrong place, rather than the loss of the normal function of lamin A, that causes the disease. It was hypothesized that part of the reason that treatment with an FTI such as alendronate is inefficient is due to prenylation by geranylgeranyltransferase. Since statins inhibit geranylgeranyltransferase, the combination of an FTI and statins was tried, and markedly improved "the aging-like phenotypes of mice deficient in the metalloproteinase Zmpste24, including growth retardation, loss of weight, lipodystrophy, hair loss, and bone defects". Repair of DNA double-strand breaks can occur by either of two processes, non-homologous end joining (NHEJ) or homologous recombination (HR). A-type lamins promote genetic stability by maintaining levels of proteins that have key roles in NHEJ and HR. Mouse cells deficient for maturation of prelamin A show increased DNA damage and chromosome aberrations and have increased sensitivity to DNA damaging agents. In progeria, the inability to adequately repair DNA damages due to defective A-type lamin may cause aspects of premature aging (also see DNA damage theory of aging) | https://en.wikipedia.org/wiki?curid=205224 | 151,816 |
Gartons Limited Under our system of plant breeding we carry the mating of varieties or breeds far beyond what is practised in the animal kingdom. In the first instance we mate varieties and also what were formerly regarded as distinct species of the same genera, and after fixation, the progeny by these combinations are further mated together. A further extension of our system which is in itself unique and instructive, is the mating of uncultivated indigenous plants of the same Natural Order as the cultivated varieties. From such combinations most valuable results have been obtained. For example In Southern Asia there exists a species of wheat botanically known as Triticum spelta. In some districts it is looked upon as an indigenous weed infesting the cultivated crops of wheat. Under no climatic conditions does the grain of this species shed its seed when ripe, and even in threshing it is not possible to separate the grains, as the spikelets break off at the bases of the glumes, the grains remaining firmly enclosed between the chaff scales. By mating the varieties of this species with cultivated varieties, new breeds have been produced which will under no conditions shed their seed when ripe, but which thresh out a perfectly clean sample with a much heavier yield per acre than common wheat. In China there is an indigenous species of oat botanically known as Avena nuda or naked oat. The peculiar feature of this species is that the grains (which are very small) grow without any husk, being protected only by the chaff | https://en.wikipedia.org/wiki?curid=15668437 | 51,100 |
Cabotage Australia also permits foreign-owned airlines incorporated under Australian law (such as Tigerair Australia and the domestic arm of Virgin Australia) to operate on domestic routes, although it prohibits such airlines from operating international routes as Australian flag carriers. They can, however still operate international routes if they are operated by an Australian-owned subsidiary. Chile has the most liberal cabotage rules in the world, enacted in 1979, which allow foreign airlines to operate domestic flights, conditional upon reciprocal treatment for Chilean carriers in the foreign airline's country. This unusual regime is partly due to Chile's geographical need for air service, and partly to incentivize liberalization in other countries amid the international expansion of its flag carrier LATAM Chile, which now has major operations in many other Latin American countries. Like Australia, Chile allows foreign companies to set up Chilean subsidiaries to offer domestic flights in Chile, regardless of reciprocity. Before 1991, Lufthansa was prohibited from flying to West Berlin, so Pan Am, British Airways, and Air France operated the routes between West Germany and West Berlin. For a short time in the late 1980s, Trans World Airlines also flew between then-West Germany and West Berlin. During this time, Pan Am flew to Tegel, in Berlin, from Munich-Riem Airport (now closed), Hamburg and Frankfurt. Air France flew from Düsseldorf. British Airways flew from Münster-Osnabrück, Hannover, and some other cities | https://en.wikipedia.org/wiki?curid=1624953 | 455,249 |
Resistive opto-isolator Its lifetime can be prolonged by limiting the controlling current to half of the maximum value. ROs based on incandescent lamps typically fail after about 20,000 hours, due to the burnout of the spiral, and are more prone to overheating. Degradation of the photoresistor is gradual and irreversible. If the operating temperature does not exceed the limit (typically 75 °C or less) then for each year of continuous operation, the dark resistance falls by 10%; at higher temperature such changes can occur within minutes. The maximum power dissipated in the photoresistor is usually specified for 25 °C and decreases by 2% for every °C of heating. Cooling below −25 °C sharply increases the response time of a photoresistor. These changes are reversible unless the cooling induces cracking in the plastic components. Soviet ROs packed in metal cases could withstand even at −60 °C, but at these temperatures their response time reached 4 seconds. Highly resistive ROs can be operated at AC voltages exceeding 200 V and used as low-power AC or DC relays, e.g., to control electroluminescent indicators. In the simplest output-limiting circuits, the RO is placed in the top (series connection) or lower (shunt) arm of the voltage divider. The series connection provides a greater controlling range (−80 dB) at DC and low frequencies. The operation is complicated by the nonlinearity of the resistance vs. the controlling current | https://en.wikipedia.org/wiki?curid=37259466 | 412,339 |
Fine chemical In fact, L-glutamic acid, D, L-methionine, L-aspartic acid and L-phenylalanine are used in large quantities as food and feed additives. About 50 peptide drugs are commercialized. The number of amino acids that make up a specific peptide varies widely. At the low end are the dipeptides. The most important drugs with a dipeptide (L-alanyl-L-proline) moiety are the “-pril” cardiovascular drugs, such as Alapril (lisinopril), Captoril (captopril), Novolac (imidapril) and Renitec (enalapril). Also the artificial sweetener Aspartame (N-L-α-Aspartyl-L-phenylalanine 1-methyl ester) is a dipeptide. At the high end there is the anticoagulant hirudin, MW ≈ 7000, which is composed of 65 amino acids. Apart from pharmaceuticals, peptides are also used for diagnostics and vaccines. The total production volume (excl. Aspartame) of chemically synthesized, pure peptides is about 1500 kilograms and sales approach $500 million on the active pharmaceutical (API) level and $10 billion on the finished drug level, respectively. The bulk of the production of peptide drugs, which comprise also the first generation anti-AIDS drugs, the “…navirs”, is outsourced to a few specialized contract manufacturers, such as Bachem, Switzerland; Chengu GT Biochem, China; Chinese Peptide Company, China; Lonza, Switzerland, and Polypeptide, Denmark. "Proteins" are “very high-molecular-weight” (MW > 100,000) organic compounds, consisting of amino acid sequences linked by peptide bonds | https://en.wikipedia.org/wiki?curid=3694845 | 459,480 |
Future of Life Institute The (FLI) is a non-profit research institute and outreach organization in the Boston area that works to mitigate existential risks facing humanity, particularly existential risk from advanced artificial intelligence (AI). Its founders include MIT cosmologist Max Tegmark and Skype co-founder Jaan Tallinn, and its board of advisors includes entrepreneur Elon Musk. FLI's mission is to catalyze and support research and initiatives for safeguarding life and developing optimistic visions of the future, including positive ways for humanity to steer its course in response to new technologies and challenges. FLI is particularly focused on the potential risks to humanity from the development of human-level or superintelligent artificial general intelligence (AGI). The Institute was founded in March 2014 by MIT cosmologist Max Tegmark, Skype co-founder Jaan Tallinn, Harvard graduate student and International Mathematical Olympiad (IMO) medalist Viktoriya Krakovna, Boston University graduate student Meia Chita-Tegmark (Tegmark's wife), and UCSC physicist Anthony Aguirre. The Institute's 14-person Scientific Advisory Board comprises 12 men and 2 women, and includes computer scientists Stuart J. Russell and Francesca Rossi, biologist George Church, cosmologist Saul Perlmutter, astrophysicist Sandra Faber, theoretical physicist Frank Wilczek, entrepreneur Elon Musk, and actors and science communicators Alan Alda and Morgan Freeman (as well as cosmologist Stephen Hawking prior to his death in 2018) | https://en.wikipedia.org/wiki?curid=42912557 | 242,951 |
Information sensitivity In many countries, unauthorized disclosure of classified information is a criminal offence, and may be punishable by fines, prison sentence, or even the death penalty, depending on the severity of the violation. For less severe violations, civil sanctions may be imposed, ranging from reprimand to revoking of security clearance and subsequent termination of employment. Whistleblowing is the intentional disclosure of sensitive information to a third-party with the intention of revealing alleged illegal, immoral, or otherwise harmful actions. There are many examples of present and former government employees disclosing classified information regarding national government misconduct to the public and media, in spite of the criminal consequences that await them. Espionage, or spying, involves obtaining sensitive information without the permission or knowledge of its holder. The use of spies is a part of national intelligence gathering in most countries, and has been used as a political strategy by nation-states since ancient times. It is unspoken knowledge in international politics that countries are spying on one another all the time, even their allies. Computer security is information security applied to computing and network technology, and is a significant and ever-growing field in computer science | https://en.wikipedia.org/wiki?curid=5316476 | 120,885 |
Plane of polarization He defined the "plane of vibration" as "the plane passing through the ray and the direction of vibration" (in agreement with Fig.1). Now suppose that a fine diffraction grating is illuminated at normal incidence. At large angles of diffraction, the grating will appear somewhat edge-on, so that the directions of vibration will be crowded towards the direction parallel to the plane of the grating. If the planes of polarization coincide with the planes of vibration (as MacCullagh and Neumann said), they will be crowded in the same direction; and if the planes of polarization are "normal" to the planes of vibration (as Fresnel said), the planes of polarization will be crowded in the normal direction. To find the direction of the crowding, one could vary the polarization of the incident light in equal steps, and determine the planes of polarization of the diffracted light in the usual manner. Stokes performed such an experiment in 1849, and it found in favor of Fresnel. In 1852, Stokes noted a much simpler experiment that leads to the same conclusion. Sunlight scattered from a patch of blue sky 90° from the sun is found, by the methods of Malus, to be polarized in the plane containing the line of sight and the sun. But it is obvious from the geometry that the vibrations of that light can only be perpendicular to that plane. There was, however, a sense in which MacCullagh and Neumann were correct | https://en.wikipedia.org/wiki?curid=55054778 | 404,147 |
Sunder Lal Hora Dr FRSE FLS (2 May 1896 – 8 December 1955) was an Indian ichthyologist and was known for his biogeographical theory on the affinities of Western Ghats and Indo-Malayan forms. He was the second Indian director of the Zoological Survey of India, succeeding Baini Prashad. Hora was born at Hafizabad in the Punjab (modern day Pakistan) on 2 May 1896. He schooled in Jullunder before college at Lahore. He met Thomas Nelson Annandale who visited his college in Lahore in 1919 and was invited to the Zoological Survey of India. In 1921 he became in-charge of ichthyology and herpetology and in 1947 became Superintendent of the Z.S.I. and then Director after Baini Prashad moved to become an advisor to the government. He was elected a Fellow of the Royal Society of Edinburgh in 1929. His proposers were James Hartley Ashworth, John Stephenson, Charles Henry O'Donoghue and James Ritchie. He died on 8 December 1955. The "Satpura hypothesis", a zoo-geographical hypothesis proposed by him that suggests that the central Indian Satpura Range of hills acted as a bridge for the gradual migrations of Malayan fauna into the peninsula and the Western Ghats of India. He supported the theory on the basis of torrential fishes which had special suckers to hold onto rocks. Later research however pointed out that his examples made use of unrelated species showing common characters that were independently evolved, that is they were examples of convergent evolution | https://en.wikipedia.org/wiki?curid=2450700 | 3,535 |
Intuition He finds that regular knowledge is based on imitation while intuitive knowledge is based on intellectual certitude. In the West, intuition does not appear as a separate field of study, and early mentions and definitions can be traced back to Plato. In his book "Republic" he tries to define intuition as a fundamental capacity of human reason to comprehend the true nature of reality. In his works "Meno" and "Phaedo", he describes intuition as a pre-existing knowledge residing in the "soul of eternity", and a phenomenon by which one becomes conscious of pre-existing knowledge. He provides an example of mathematical truths, and posits that they are not arrived at by reason. He argues that these truths are accessed using a knowledge already present in a dormant form and accessible to our intuitive capacity. This concept by Plato is also sometimes referred to as anamnesis. The study was later continued by his followers. In his book "Meditations on First Philosophy", Descartes refers to an “intuition” as a pre-existing knowledge gained through rational reasoning or discovering truth through contemplation. This definition is commonly referred to as rational intuition. Later philosophers, such as Hume, have more ambiguous interpretations of intuition | https://en.wikipedia.org/wiki?curid=154170 | 279,722 |
Change vector In an Oracle database, a change vector consists of a single change to a single data block. A change vector is the smallest unit of change recorded in a redo log. | https://en.wikipedia.org/wiki?curid=33547062 | 275,264 |
Cyberwarfare in the United States The plan is to exploit Huawei's technology so that when the company sold equipment to other countries—including both allies and nations that avoid buying American products—the NSA could roam through their computer and telephone networks to conduct surveillance and, if ordered by the president, offensive cyberoperations. In June 2019, Russia has conceded that it is "possible" its electrical grid is under cyber-attack by the United States. The "New York Times" reported that American hackers from the United States Cyber Command planted malware potentially capable of disrupting the Russian electrical grid. The Pentagon has had an information sharing arrangement, the Defense Industrial Base Cybersecurity and Information Assurance (DIBCIA) program, in place with some private defense contractors since 2007 to which access was widened in 2012. A number of other information sharing initiatives such as the Cyber Intelligence Sharing and Protection Act (CISPA) and Cybersecurity Information Sharing Act (CISA) have been proposed, but failed for various reasons including over fears that they have too few limits, and could be used to spy on the general public. The United States Cyber Command (USCYBERCOM) is a United States Armed Forces Unified Combatant Command | https://en.wikipedia.org/wiki?curid=28844498 | 231,520 |
NEMA stepper motor NEMA standard (NEMA ICS 16-2001) describes stepper motors. NEMA stepper motors are labeled most notably by faceplate size, NEMA 17 being a stepper motor with a 1.7 x 1.7 inch faceplate. NEMA 17 stepper motor is a stepper motor type specified by NEMA. NEMA 17 steppers have a 1.7 x 1.7 inch faceplate. NEMA 17 steppers have usually more torque than the smaller variants, such as NEMA 14. NEMA 17 steppers are commonly used in 3D-printers. http://reprap.org/wiki/NEMA_Motor | https://en.wikipedia.org/wiki?curid=53828762 | 194,215 |
Arc welding This is important because in manual welding, it can be difficult to hold the electrode perfectly steady, and as a result, the arc length and thus voltage tend to fluctuate. Constant voltage power supplies hold the voltage constant and vary the current, and as a result, are most often used for automated welding processes such as gas metal arc welding, flux cored arc welding, and submerged arc welding. In these processes, arc length is kept constant, since any fluctuation in the distance between the wire and the base material is quickly rectified by a large change in current. For example, if the wire and the base material get too close, the current will rapidly increase, which in turn causes the heat to increase and the tip of the wire to melt, returning it to its original separation distance. The direction of current used in arc welding also plays an important role in welding. Consumable electrode processes such as shielded metal arc welding and gas metal arc welding generally use direct current, but the electrode can be charged either positively or negatively. In general, the positively charged anode will have a greater heat concentration (around 60%). "Note that for stick welding in general, DC+ polarity is most commonly used. It produces a good bead profile with a higher level of penetration. DC- polarity results in less penetration and a higher electrode melt-off rate. It is sometimes used, for example, on thin sheet metal in an attempt to prevent burn-through | https://en.wikipedia.org/wiki?curid=440996 | 443,719 |
Protein–protein interaction Nuclear magnetic resonance is advantageous for characterizing weak PPIs. Proteins hold structural domains that allow their interaction with and bind to specific sequences on other proteins: The study of the molecular structure can give fine details about the interface that enables the interaction between proteins. When characterizing PPI interfaces it is important to take into account the type of complex. Parameters evaluated include size (measured in absolute dimensions Å or in solvent-accessible surface area (SASA)), shape, complementarity between surfaces, residue interface propensities, hydrophobicity, segmentation and secondary structure, and conformational changes on complex formation. The great majority of PPI interfaces reflects the composition of protein surfaces, rather than the protein cores, in spite of being frequently enriched in hydrophobic residues, particularly in aromatic residues. PPI interfaces are dynamic and frequently planar, although they can be globular and protruding as well. Based on three structures – insulin dimer, trypsin-pancreatic trypsin inhibitor complex, and oxyhaemoglobin – Cyrus Chothia and Joel Janin found that between 1,130 and 1,720 Å of surface area was removed from contact with water indicating that hydrophobicity is a major factor of stabilization of PPIs. Later studies refined the buried surface area of the majority of interactions to 1,600±350 Å | https://en.wikipedia.org/wiki?curid=2161878 | 67,395 |
Endophyte One group of fungal endophytes are the arbuscular mycorrhizal fungi involving biotrophic Glomeromycota associated with various plant species. As often with other organisms associated with plants such as mycorrhizal fungus, endophytes gain carbon from their association with the plant host. Bacterial endophytes are polyphyletic, belonging to broad range of taxa, including α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, Firmicutes, Actinobacteria. One or more endophytic organisms are found in nearly every land plant. It is suggested that areas of high plant diversity such as tropical rainforests may also contain the highest diversity of endophytic organisms that possess novel and diverse chemical metabolites. It has been estimated that there could be approximately 1 million endophytic fungi that exist in the world. A diazotrophic bacterium isolated in lodgepole pines ("Pinus contorta") in British Columbia, Canada, is "Paenibacillus polymyxa", which may help its host by fixing nitrogen. Endophytes include a wide variety of microorganisms including fungi, bacteria and viruses. There are two different means of classifying endophytes. The first method divides endophytes into two categories: systemic (true) and nonsystemic (transient). These categories are based on the endophyte's genetics, biology and mechanism of transmission from host to host | https://en.wikipedia.org/wiki?curid=889890 | 150,771 |
Enrique Salinas Enrique Eduardo Guillermo Salinas de Gortari (November 15, 1952 – December 6, 2004) was the third of four brothers of former president of Mexico Carlos Salinas. On December 6, 2004 his corpse was found, with a plastic bag placed over his head, inside a Volkswagen Passat. The vehicle was abandoned in the upmarket municipality of Huixquilucan, Estado de México, on the outskirts of Mexico City. The authorities gave asphyxiation as the cause of death. Unlike his brothers ex-president Carlos and convicted felon Raúl, Enrique had eschewed the world of politics in favour of the business sector. Salinas' widow and kids reside in Lausanne, Switzerland | https://en.wikipedia.org/wiki?curid=1250773 | 456,848 |
Autoclave (industrial) Customarily, the metal thickness is driven by the code requirements relating to visual inspection. Thinner metal can be used, providing the welds are radiographed. This saves cost when the metal is not SA516 but stainless steel or a refractory alloy. Of the entire machine, the costliest (depending on the size of the autoclave) and most important single piece of hardware is the fast-opening door. It must be of full diameter to allow access to the working space, seal tightly against rated pressure at the highest shell temperature, operate readily and quickly, and comply with the same safety code that governs the rest of the pressure vessel. Of all safety-related concerns, the most critical are those which relate to the door's operation. There are several types of fast-opening doors commonly used. The simplest and most primitive type of door, a bolted plate or flanged cap on some sort of hinge, is no longer considered even minimally acceptable for production autoclaves because it is anything but quick in opening and closing. For vessels up to four feet in diameter and rated at not much over 125 psi, a hinged semi-elliptical door secured by lever-operated cam-locking T-bolts works essentially as quickly and as easily as the more commonly used rotating locking ring door. This door design uses up to a dozen or so latching T-bolts on the door hub (see photos), the stationary part fitted to the cylindrical vessel itself, which engage matching lugs welded to the door | https://en.wikipedia.org/wiki?curid=21441673 | 348,938 |
Granite Sentry was a Cheyenne Mountain nuclear bunker improvement program "to provide a Message Processing Subsystem and a Video Distribution Subsystem, and [to upgrade] the NORAD Computer System display capability and four major centers: (1) the Air Defense Operations Center, (2) the NORAD Command Center, (3) the Battle Staff Support Center, and (4) the Weather Support Unit." was also to process and display "nuclear detection data provided from the Integrated Correlation and Display System." For $230 million the program was also to "replace display screens of the Attack Warning and Attack Assessment System", and was delayed from 1993 to 1996. and other Cheyenne Mountain Upgrade interfaces were tested in 1997, and Granite Sentry's processing regarding "simulated [nuclear] detonation messages…injected into the Defense Support Program Data Distribution Center [was] not adequate...". | https://en.wikipedia.org/wiki?curid=37097222 | 98,659 |
Tetrode Superhet receivers reappeared in the early 1930s when, because of the proliferation of transmitting stations, their greater selectivity became an important advantage; almost all receivers operate on this principle today, albeit with a higher IF frequency. In the screen grid class of tetrode, the main function of the second grid is to act as an electrostatic screen between the anode and the control grid (i.e. the first grid) in order to reduce the internal capacitance between control grid and anode. The first true screen-grid valve, with a screen grid designed for this purpose, was patented by Hiroshi Ando in 1919, and the first practical versions were built by N. H. Williams and Albert Hull at General Electric and Bernard Tellegen at Phillips in 1926. This type of tetrode was developed to correct deficiencies in the triode tube which became apparent when attempts were made to use triodes as small-signal radio-frequency amplifiers. In the triode, the control grid was next to the plate. Capacitance between these two electrodes caused instability and oscillation when both anode and grid were connected into tuned resonant circuits, as was the case in early radios, or in any application where the anode circuit presented an inductive load to the valve. Oscillation could only be avoided by using very small stage gain at frequencies above about 100 kHz, and at frequencies above 1 MHz, triodes are virtually useless in tuned amplifiers in which both anode and grid circuits are tuned to the same frequency | https://en.wikipedia.org/wiki?curid=102451 | 381,343 |
Hybrid electric vehicles in the United States The fleet of hybrid electric vehicles in the United States, with over 4 million units sold through April 2016, is the second largest in the world after Japan (over 5 million). American sales of hybrid electric vehicles represent about 36% of the more than 11 million hybrid sold worldwide through April 2016. Since their inception in 1999, a total of 4,058,258 hybrid electric automobiles and sport utility vehicles have been sold in the country through May 2016. Sales of hybrid vehicles in the U.S. began to decline following the financial crisis of 2007–08, and after a short recovery, began to decline again in 2014 due to low gasoline prices. Hybrid sales in the American market achieved its highest market share ever in 2013, capturing 3.19% of new car sales that year, and dropped below 2% by April 2016. The top selling hybrid electric vehicle in the country is the conventional Toyota Prius, which has sold 1,643,000 units since 2000 through April 2016, representing a 40.8% market share of all hybrids sold in the U.S. since 1999. Cumulative sales of the Prius nameplate totaled 1,932,805 units delivered through April 2016, representing a 48.0% market share of total hybrid sales in the U.S. , the conventional Prius is followed by the Toyota Camry Hybrid, with 345,640 units sold since 2006, the Honda Civic Hybrid, with cumulative sales of 234,610 vehicles since 2002, the Ford Fusion Hybrid with 166,341 units since 2009, and the Toyota Prius c with 165,075 units since 2012 | https://en.wikipedia.org/wiki?curid=26712551 | 378,289 |
Engine configuration There may be two, three, four or five valves per cylinder, with the intake valves outnumbering the exhaust valves in case of an odd number. Poppet valves are opened by means of a camshaft which revolves at half the crankshaft speed. This can be either chain, gear or toothed belt driven from the crankshaft, and can be located in the crankcase (where it may serve one or more banks of cylinders) or in the cylinder head. If the camshaft is located in the crankcase, a valve train of pushrods and rocker arms will be required to operate overhead valves. Mechanically simpler are side valves, where the valve stems rested directly on the camshaft However, this gives poor gas flows within the cylinder head as well as heat problems and fell out of favor for automobile use, see "flathead engine". The majority of modern automobile engines place the camshaft on the cylinder head in an overhead camshaft (OHC) design. There may be one or two camshafts in the cylinder head; a single camshaft design is called single overhead camshaft (SOHC). A design with two camshafts per cylinder head is called double overhead camshaft (DOHC). Note that the camshafts are counted per cylinder head, so a V engine with one camshaft in each of its two-cylinder heads is still an SOHC design, and a V engine with two camshafts per cylinder head is DOHC, or informally a "quad cam" engine. With overhead camshafts, the valvetrain will be shorter and lighter, as no pushrods are required | https://en.wikipedia.org/wiki?curid=199966 | 448,366 |
Minoan Moulds of Palaikastro The () are double sided schist casting moulds from the time of the Minoan culture for casting cultural figurines and symbols. These include female figurines with raised arms, double axes (Λάβρυες, "Labryes") and opium poppy flowers or capsules, two double axes with indented edges, "sanctification horns" and a geared disc with a cross and astral symbols, which could have been used for astronomical predictions of solar and lunar eclipses. They have been found near Palaikastro in the eastern part of Crete. The two moulds were discovered in October 1899 by a farmer from Karydi northeast of the village of Palaikastro. The Gendarmerie sent the finds to the then Cretan capital Chania, where they were assessed and kept by the archeologist and historian Stefanos Xanthoudidis. He recognised the importance of ancient craftsmanship and delivered the moulds to the museum in Heraklion which had been set up in 1883. Xanthoudidis described the objects in March 1900 in an article ("Ancient molds from Sitia in Crete") in the journal of the Archaeological Society of Athens. This publication included photos of plaster casts of all four sides of the moulds. Xanthoudidis described the two moulds, which were made from relatively soft and brittle schist as Plate Α and Plate Β. His plaster casts, which are also reproduced on the right hand side, are mirror images of the original moulds. Both moulds are wide, high and thick, while the width of the plaster casts is | https://en.wikipedia.org/wiki?curid=60752454 | 291,529 |
Action Target is a manufacturer of custom shooting ranges and portable steel targets for military, law enforcement, Special Forces groups, tactical training schools, and commercial applications based in Provo, Utah. Since its founding in 1985, has increased its inventory to include over 4,000 products. The company designs, delivers, and installs indoor and outdoor range equipment throughout the world. John Mulligan has been Chief Operating Officer since 2015. His predecessor, John Curtis, was a partner in the firm who was elected the mayor of Provo in 2008 and U.S. Representative for Utah's 3rd congressional district in 2016. was founded in 1986 by Kyle Bateman and Addison Sovine to address a need they saw with law enforcement training, and operated out of Bateman's bedroom at first. They soon moved to a larger facility near the Interstate 15 freeway in Provo before moving to a manufacturing facility nearby next to a residential neighborhood. In 1989, the company moved to manufacturing facilities on the west side of Provo on property which used to house a wrecking yard. Throughout the next fifteen years, expanded and built several large buildings to house its manufacturing. In late 2003 or early 2004, the company donated land to Provo City in order to extend the street and provide an alternate route for delivery trucks, as well as offering to purchase properties to create a buffer zone between its facilities and those of residential neighbors. The company produced two bullet-proof training villages for use by the U.S | https://en.wikipedia.org/wiki?curid=24967851 | 452,079 |
Rackmount KVM It had been previously reported that LG, the last manufacturer for this form factor display, announced the product was End Of Life (EOL) in 2013. However, Sharp Electronics has introduced a new 20.1" display as of 2 December 2014. The most common LCD sizes currently in production are 15", 17", 19" and 20". Several manufacturers have released KVM models providing two or three displays in a 2U or 3U height. A wide variety of pointing devices are available to provide mouse functionality. Many keyboards include pointing devices such as a small trackball, touch pad, joy stick (Hulapoint), or pointing stick. Similar pointing devices are available as stand-alone modules and can be installed separately from the keyboard. In a lay-flat design, there is sufficient height in a 1U design to install a larger 1-1/2" trackball and larger trackballs in the KVMs which are 2U in height. Some manufacturers have made provision for using a true mouse by providing a location for storage and a flat surface to use it on. Many KVMs are offered with a built-in KVM switch allowing the one KVM to control a number of connected computers without using an external KVM switch. The KVM switch can be controlled either by on-screen menus, hot-key commands, or, on some KVM models, via front accessible push buttons. | https://en.wikipedia.org/wiki?curid=40951217 | 412,880 |
High-temperature superconductivity There are four possible crystallographic sites for oxygen: O(1), O(2), O(3) and O(4). The coordination polyhedra of Y and Ba with respect to oxygen are different. The tripling of the perovskite unit cell leads to nine oxygen atoms, whereas YBaCuO has seven oxygen atoms and, therefore, is referred to as an oxygen-deficient perovskite structure. The structure has a stacking of different layers: (CuO)(BaO)(CuO)(Y)(CuO)(BaO)(CuO). One of the key feature of the unit cell of YBaCuO (YBCO) is the presence of two layers of CuO. The role of the Y plane is to serve as a spacer between two CuO planes. In YBCO, the Cu–O chains are known to play an important role for superconductivity. "T" is maximal near 92 K when "x" ≈ 0.15 and the structure is orthorhombic. Superconductivity disappears at "x" ≈ 0.6, where the structural transformation of YBCO occurs from orthorhombic to tetragonal. The preparation of other cuprates is more difficult than the YBCO preparation. They also have a different crystal structure: they are tetragonal where YBCO is orthorhombic. Problems in these superconductors arise because of the existence of three or more phases having a similar layered structure. Moreover, the crystal structure of other tested cuprate superconductors are very similar. Like YBCO, the perovskite-type feature and the presence of simple copper oxide (CuO) layers also exist in these superconductors. However, unlike YBCO, Cu–O chains are not present in these superconductors | https://en.wikipedia.org/wiki?curid=101336 | 269,392 |
Zoothamnium niveum niveum" for its attached bacteria "Candidatus" Thiobios zoothamnicoli (a member of the Gammaproteobacteria) are its active alternation between oxygen-rich and sulfide-rich conditions. This alternation can occur through the regular contraction and extension of the colonies and through the water currents set up by the beating of the cilia in the region of the oral opening of the ciliates. The rapid contraction and slow re-extension of the colonies causes a flow of both sulfide-rich water for the feeding of the bacteria and normal oxygenated seawater for the respiration of "Z. niveum". Through the beating of its cilia at the oral apparatus of "Zoothamnium" is the mixing regulated. When there is a low supply of sulfur compounds, the bacteria use the sulfur that is stored inside their cells. They eventually appear pale and transparent after four hours because the stored sulfur has been consumed. However, if the sulfide concentration is too high, it can be toxic to the "Zoothamnium" colonies and kill the ciliates despite the bacteria. Bacteria close to the oral end of the microzooids have a coccoid form, a larger volume, and a higher division rate than the rod-shaped bacteria on the stalks, despite both belonging to the same species. This is because the mixing of water by the beating of the oral cilia result in a more optimal concentration of both oxygen and sulfide in the water there | https://en.wikipedia.org/wiki?curid=54643138 | 187,487 |
Adjustment clause In insurance, an adjustment clause in a contract specifies how the amount of a claim (particularly a claim against an insurance company) will be determined for the purposes of a settlement, giving consideration to objections made by the debtor or insurance company, as well as the allegations of the claimant in support of his claim. For example: Adjustment of claims is not confined to claims against insurance companies. An allowance made by a creditor, particularly a storekeeper, in response to a complaint by the debtor respecting the accuracy of the account or other claim, or a reduction in the claim or account made to induce a prompt payment, is in a proper sense an adjustment. | https://en.wikipedia.org/wiki?curid=23403807 | 459,010 |
Thermal oxidation However, fast oxidation leaves more dangling bonds at the silicon interface, which produce quantum states for electrons and allow current to leak along the interface. (This is called a "dirty" interface.) Wet oxidation also yields a lower-density oxide, with lower dielectric strength. The long time required to grow a thick oxide in dry oxidation makes this process impractical. Thick oxides are usually grown with a long wet oxidation bracketed by short dry ones (a "dry-wet-dry" cycle). The beginning and ending dry oxidations produce films of high-quality oxide at the outer and inner surfaces of the oxide layer, respectively. Mobile metal ions can degrade performance of MOSFETs (sodium is of particular concern). However, chlorine can immobilize sodium by forming sodium chloride. Chlorine is often introduced by adding hydrogen chloride or trichloroethylene to the oxidizing medium. Its presence also increases the rate of oxidation. can be performed on selected areas of a wafer, and blocked on others. This process, first developed at Philips, is commonly referred to as the local oxidation of silicon (LOCOS) process. Areas which are not to be oxidized are covered with a film of silicon nitride, which blocks diffusion of oxygen and water vapor due to its oxidation at a much slower rate. The nitride is removed after oxidation is complete | https://en.wikipedia.org/wiki?curid=8556260 | 406,592 |
Jiang Haokang (; March 1935 – 15 October 2019) was a Chinese aerospace engineer and a professor at Beihang University. An expert on aeroengine testing and flow measurement technology, he won the State Science and Technology Progress Award (First Prize) in 1993. Jiang was born in March 1935 in Wujin, Jiangsu, Republic of China. In 1953, he became one of the first class of students at the newly established Beihang University (then called Beijing Institute of Aeronautics) and studied engine design. Upon graduation in 1958, he was hired by the university as a faculty member. From 1980 to 1983, he was a visiting scholar at Cranfield University in England. With his research focus on aeroengine testing and flow measurement technology, Jiang was a recognized expert in the field in China. He was awarded the First Prize of the Guanghua Science and Technology Fund and a special pension by the Chinese government for distinguished scientists. In 1993, his research on "a large-scale axial flow compressor facility and dynamic measurement techniques for rotor flow study" won the State Science and Technology Progress Award (First Prize). Jiang died on 15 October 2019 in Chengdu, aged 84. | https://en.wikipedia.org/wiki?curid=62118559 | 200,086 |
Arecibo Observatory On May 12, 2011, the agency informed Cornell University that, as of October 1, 2011, it would no longer be the operator of the NAIC and the Arecibo Observatory. At that time, Cornell transferred its operations to SRI International, along with two other managing partners, Universities Space Research Association and Universidad Metropolitana de Puerto Rico, with a number of other collaborators. Upon the award of the new cooperative agreement for NAIC management and operation, NSF also decertified NAIC as a Federally Funded Research and Development Center (FFRDC), with the stated goal of providing the NAIC with greater freedom to establish broader scientific partnerships and pursue funding opportunities for activities beyond the scope of those supported by NSF. In October 2015, the NSF released a "Dear Colleague Letter" reiterating its desire for a "substantially reduced funding commitment from NSF". On September 30, 2016, the NSF released a followup to the October 2015 "Dear Colleague Letter" announcing a solicitation for future operation of the Observatory stating "The subject Solicitation will request the submission of formal proposals involving the continued operation of under conditions of a substantially reduced funding commitment from NSF." The damage sustained from Hurricane Maria in September 2017 further clouded the observatory's future | https://en.wikipedia.org/wiki?curid=159191 | 434,195 |
Environmental Mutagenesis and Genomics Society In 1969, the EMS established the Environmental Mutagen Information Center (EMIC) at the Oak Ridge National Laboratory, which developed the first bibliographic database on environmental mutagenesis, facilitating research throughout the 1970s and early 1980s, particularly the development of tests for genetic toxicology, through the establishment of a register of substances tested for toxicity. This, in turn, contributed significantly to the GENE-TOX program, established by Drs. Angela Auletta and Michael D. Waters at the US EPA and it now forms part of TOXNET. During the early 1970s, the society played a significant part in the development of the US Toxic Substances Control Act of 1976, enabling the United States Environmental Protection Agency to include mutagenicity data in regulatory decisions. The EMS "Committee 17", chaired by John W. Drake, published an influential position paper; “Environmental Mutagenic Hazards”, in Science in 1975. This described the research needs and regulatory responsibility for managing potential mutagenic compounds in the environment. It influenced research direction, regulatory procedures and mutagenicity testing within industry. In 1970 the EMS established the book series "Chemical Mutagens: Principles and Methods for Their Detection" and the first volume was published in the following year. This has included a number of influential papers, from the first by Dr. Bruce N. Ames on the Salmonella (Ames) mutagenicity assay | https://en.wikipedia.org/wiki?curid=30040694 | 155,819 |
World clock A world clock is a clock which displays the time for various cities around the world. The display can take various forms: There are also worldtime watches, both wrist watches and pocket watches. Sometime manufacturers of timekeepers erroneously apply the worldtime label to instruments that merely indicate time for two or a few time zones, but the term should be used only for timepieces that indicate time for all major time zones of the globe. | https://en.wikipedia.org/wiki?curid=1563736 | 260,337 |
Alexander Bain (inventor) Bain worked on an experimental fax machine from 1843 to 1846. He used a clock to synchronise the movement of two pendulums for line-by-line scanning of a message. For transmission, Bain applied metal pins arranged on a cylinder made of insulating material. An electric probe that transmitted on-off pulses then scanned the pins. The message was reproduced at the receiving station on electrochemically sensitive paper impregnated with a chemical solution similar to that developed for his chemical telegraph. In his patent description dated 27 May 1843 for "improvements in producing and regulating electric currents and improvements in timepieces, and in electric printing, and signal telegraphs," he claimed that "a copy of any other surface composed of conducting and non-conducting materials can be taken by these means". The transmitter and receiver were connected by five wires. In 1850 he applied for an improved version but was too late, as Frederick Bakewell had obtained a patent for his superior "image telegraph" two years earlier in 1848. Bain's and Bakewell's laboratory mechanisms reproduced poor quality images and were not viable systems because the transmitter and receiver were never truly synchronized. In 1861, the first practical operating electro-mechanical commercially exploited telefax machine, the Pantelegraph, was invented by the Italian physicist Giovanni Caselli. He introduced the first commercial telefax service between Paris and Lyon at least 11 years before the invention of workable telephones | https://en.wikipedia.org/wiki?curid=1341253 | 211,483 |
Sutter's Fort Following word of the Gold Rush, the fort was largely deserted by the 1850s and fell into disrepair. In 1891, the Native Sons of the Golden West, who sought to safeguard many of the landmarks of California's pioneer days, purchased and rehabilitated when the City of Sacramento sought to demolish it. Repair efforts were completed in 1893 and the fort was given by the Native Sons of the Golden West to the State of California. In 1947, the fort was transferred to the authority of California State Parks. Most of the original neighborhood structures were initially built in the late 1930s as residences, many of which have been converted to commercial uses such as private medical practices. The history of the neighborhood is largely residential. is located on level ground at an elevation of approximately above mean sea datum. The slope elevation decreases northward toward the American River and westward toward the Sacramento River. Slope elevation gradually increases to the south and east, away from the rivers. All surface drainage flows toward the Sacramento River. Groundwater in the vicinity flows south-southwest toward the Sacramento Delta. However, after peak rainfall, the Sacramento River swells and the groundwater flow can actually reverse away from the river. | https://en.wikipedia.org/wiki?curid=36822 | 323,242 |
Larmor precession To calculate the spin of a particle in a magnetic field, one must also take into account Thomas precession. The spin angular momentum of an electron precesses counter-clockwise about the direction of the magnetic field. An electron has a negative charge, so the direction of magnetic moment is opposite to that of its spin. | https://en.wikipedia.org/wiki?curid=2784730 | 22,367 |
TV tuner card Like the analog cards, the Hybrid and Combo tuners can have specialized chips on the tuner card to perform the encoding, or leave this task to the CPU. The tuner cards with this 'hardware encoding' are generally thought of as being higher quality. Small USB tuner sticks have become more popular in 2006 and 2007 and are expected to increase in popularity. These small tuners generally do not have hardware encoding due to size and heat constraints. While most TV tuners are limited to the radio frequencies and video formats used in the country of sale, many TV tuners used in computers use DSP, so a firmware upgrade is often all that's necessary to change the supported video format. Many newer TV tuners have flash memory big enough to hold the firmware sets for decoding several different video formats, making it possible to use the tuner in many countries without having to flash the firmware. However, while it is generally possible to flash a card from one analog format to another due to the similarities, it is generally not possible to flash a card from one digital format to another due to differences in decode logic necessary. Many TV tuners can function as FM radios; this is because there are similarities between broadcast television and FM radio. The FM radio spectrum is close to (or even inside) that used by VHF terrestrial TV broadcasts. And many broadcast television systems around the world use FM audio. So listening to an FM radio station is simply a case of configuring existing hardware | https://en.wikipedia.org/wiki?curid=626814 | 420,907 |
Prototype 2 After eradicating the virus in Africa, Mexico and Russia, Alex travels around the world, wondering about if the virus has made him a human, humanity's killer or its savior. Alex slowly begins to decide that he is the earth's savior and will usher it into a new age of prosperity after he wipes out humanity. However, this changes when he falls for a woman. When the woman betrays him, he decides that he will wipe out humanity, and so he returns to New York City and makes it NYZ. The second comic, dubbed the Survivors, focuses on a former police officer, Conrad, who joins up with Ami Levin, a religiously tolerant person and Marcie, an art student. The three run afoul of Lieutenant Riley; he would, however, agree to let Conrad see his wife, so long he agrees to work for Gentek. Unbeknownst to Conrad, his wife is dead, and he ended up in a project called Orion. The third comic, entitled the Labyrinth introduced Heller and Mike Marcos. Development of the game started soon after the success of the first game and was in development for three years. The game was first shown at the Spike 2010 VGA Awards in December. The game was revealed to be the main focus of the April 2011 EGM Issue. It was displayed in "EGM" and "EGMI" in 2011 revealing many new details about the game's plot, characters and gameplay. The game's graphics have been completely updated with buildings being much more detailed and deformation of vehicles, mutants and humans being much more visual. The game was also partially written by Dan Jolley | https://en.wikipedia.org/wiki?curid=30020776 | 155,801 |
Diauxie cAMP, in turn, is required for the catabolite activator protein (CAP) to bind to DNA and activate the transcription of the lac operon, which includes genes necessary for lactose metabolism. The presence of allolactose, a metabolic product of lactose, is sensed through the activity of the lac repressor, which inhibits transcription of the lac operon until lactose is present. Thus, if glucose is present, cAMP levels remain low, so CAP is unable to activate transcription of the lac operon, regardless of the presence or absence of lactose. Upon the exhaustion of the glucose supply, cAMP levels rise, allowing CAP to activate the genes necessary for the metabolism of other food sources, including lactose if it is present. More recent research however suggests that the cAMP model is not correct in this instance since cAMP levels remain identical under glucose and lactose growth conditions, and a different model has been proposed and it suggests that the lactose-glucose diauxie in "E. coli" may be caused mainly by inducer exclusion. In this model, glucose transport via the EIIA shuts down lactose permease when glucose is being transported into the cell, so lactose is not transported into cell and used. While the cAMP/CAP mechanism may not play a role in the glucose/lactose diauxie, it is a suggested mechanism for other diauxie . | https://en.wikipedia.org/wiki?curid=4361880 | 142,974 |
Crimes involving radioactive substances On November 5, 1974, Kerr-McGee worker and labor union activist Karen Silkwood found herself exposed to plutonium-239 after working to grind and polish plutonium pellets by way of a glovebox to be used in nuclear fuel rods at the Cimarron Fuel Fabrication Site in Oklahoma. Inspection of the gloves would yield no evidence of external leakage of radioactive contaminant from the glovebox, despite the fact that plutonium had been found on those surfaces of the gloves that had contact with Silkwood's hands, and no other source for a plutonium leak could be ascertained despite thorough inspections of the air vents and surrounding surfaces. However, on November 6, despite Silkwood's prior decontamination and self-inspection, a detection on her part the next day yielded more signs of alpha activity on her hands, while health physics staff at the plant subsequently detected further alpha activity on her right forearm, neck and face. On November 7, Silkwood tested positive for very significant levels of alpha activity, and an inspection of her apartment showed high levels of radioactive contamination. Thereafter, Silkwood and two other co-workers personally associated with her (roommate Sherri Ellis and boyfriend Drew Stephens) would be tested at Los Alamos National Laboratory; while the latter two only tested positive for insignificant amounts of plutonium exposure, Silkwood was found to have of plutonium-239 in her lungs, though researcher Dr. George Voelz insisted that this amount was still negligible and non-harmful | https://en.wikipedia.org/wiki?curid=8126990 | 287,047 |
Political economy in anthropology It is important to emphasize that this book was not based on fieldwork, and itself proposed a cross-cultural universalistic model of peasant economic behaviour based upon a set of fixed theoretical principles, not a reading of peasant culture. Firstly, he argued that peasants were "risk averse", or, put differently, followed a "safety first" principle. They would not adopt risky new seeds or technologies, no matter how promising, because tried and true traditional methods had demonstrated, not promised, effectiveness. This gives peasants an unfair reputation as "traditionalist" when in fact they are just risk averse. Secondly, Scott argues that peasant society provides "subsistence insurance" for its members to tide them over those occasions when natural or man-made disaster strikes. Although fieldwork has not supported many of Scott's conclusions, the book encouraged a generation of researchers. | https://en.wikipedia.org/wiki?curid=38452127 | 506,034 |
Plain tobacco packaging The company rearranged its assets to become a Hong Kong investor in order to use the investor-state dispute settlement provisions in the Australia-Hong Kong Bilateral Investment treaty (BIT). Immediately following the passage of legislation on 21 November 2011, Philip Morris announced it had served a notice of arbitration under Australia's Bilateral Investment Treaty with Hong Kong, seeking the suspension on the plain packaging laws and compensation for the loss of trademarks. Allens Arthur Robinson represented Philip Morris. In response, Health Minister Nicola Roxon stated that she believed the government was "on very strong ground" legally, and that the government was willing to defend the measures. The continuance of trade and investment proceedings on the issue has been described as an affront to the rule of law in Australia. Dr Patricia Ranald, Convener of the Australian Fair Trade and Investment Network said that big tobacco and other global corporations are lobbying hard to include the right of foreign investors to sue governments in the current negotiations for a Trans-Pacific Partnership Agreement (TPPA). Philip Morris International lost its case in December 2015. In November 2011, British American Tobacco announced that it would challenge the laws in the High Court as soon as they gained royal assent. In August 2012, the High Court ruled in favour of the Australian government | https://en.wikipedia.org/wiki?curid=28424452 | 481,092 |
Ceramics museum A ceramics museum is a museum wholly or largely devoted to ceramics, usually ceramic art. Its collections may also include glass and enamel, but typically concentrate on pottery, including porcelain. Most national collections are in a more general museum covering all of the arts, or just the decorative arts. However, there are a number of specialized ceramics museums, with some focusing on the ceramics of just one country, region or manufacturer. Others have international collections, which may be centered on ceramics from Europe or East Asia or have a more global emphasis. Outstanding major ceramics collections in general museums include The Palace Museum, Beijing, with 340,000 pieces, and the National Palace Museum in Taipei city, Taiwan (25,000 pieces); both are mostly derived from the Chinese Imperial collection, and are almost entirely of pieces from China. In London, the Victoria and Albert Museum (over 75,000 pieces, mostly after 1400 CE) and British Museum (mostly before 1400 CE) have very strong international collections. The Metropolitan Museum of Art in New York and Freer Gallery of Art in Washington DC (12,000, all East Asian) have perhaps the best of the many fine collections in the large city museums of the United States. The Corning Museum of Glass, in Corning, New York, has more than 45,000 glass objects. Many of the historic ceramics manufacturers have museums at or very near their factories, sometimes owned by the company, sometimes independent institutions | https://en.wikipedia.org/wiki?curid=22654329 | 266,907 |
Hatred In many countries, deliberate use of hate speech is a criminal offence prohibited under "incitement to hatred" legislation. It is often alleged that the criminalization of hate speech is sometimes used to discourage legitimate discussion of negative aspects of voluntary behavior (such as political persuasion, religious adherence and philosophical allegiance). There is also some question as to whether or not hate speech falls under the protection of freedom of speech in some countries. Both of these classifications have sparked debate, with counter-arguments such as, but not limited to, a difficulty in distinguishing motive and intent for crimes, as well as philosophical debate on the validity of valuing targeted hatred as a greater crime than general misanthropy and contempt for humanity being a potentially equal crime in and of itself. The neural correlates of hate have been investigated with an fMRI procedure. In this experiment, people had their brains scanned while viewing pictures of people they hated. The results showed increased activity in the middle frontal gyrus, right putamen, bilaterally in the premotor cortex, in the frontal pole, and bilaterally in the medial insular cortex of the human brain. Hate, like love, takes different shapes and forms in different languages. While it may be fair to say that one single emotion exists in English, French (haine), and German (Hass), hate is historically situated and culturally constructed: it varies in the forms in which it is manifested | https://en.wikipedia.org/wiki?curid=19328052 | 147,024 |
Coral of life It follows in part from the above characterization that a coral is able to show many aspects of the history and diversity of life simultaneously in a single diagram, providing a summary of information which is impossible to do with trees. These include The figure on the right is a first attempt to display a diagram that depicts all these features together. The Coral of Life is embedded in a two-dimensional space with geological time as the vertical axis, and species diversity as the horizontal. Divergence times, sister group relationships and species richness values were derived from various sources. Branch shapes are drawn to indicate gradual diversification, and extinctions are shown wherever information was available on past richness values. Large groups are shown in different colors. Major events in the history of life are noted. Self-similarity is demonstrated by zooming into the monocots, then to orchids, cypripedoids and the Cypripedium genus, by which the coral transforms into a network (due to common hybridization among orchids). At a first glance, it is similar to romerograms often used in paleontology, but there is a remarkable difference that requires a more detailed discussion of historical classification of life. The last, but not the least important, feature of the Coral of Life is that it requires a classification valid for the past and present life viewed together | https://en.wikipedia.org/wiki?curid=60823876 | 158,756 |
Alexandra Ladies' Club The is an historic building in Victoria, British Columbia, Canada. | https://en.wikipedia.org/wiki?curid=57643340 | 316,255 |
Automotive head-up display An automotive head-up display or automotive heads-up display —also known as a auto-HUD— is any transparent display that presents data in the automobile without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view information with the head positioned "up" and looking forward, instead of angled down looking at lower instruments. At this time, there are two different approaches to OEM HUDs in automobiles. The first is to treat the back of the windshield in such a way that an image projected onto it will reflect to the driver. The second is to have a small combiner that is separate from the windshield. Combiners can be retracted. These displays are becoming increasingly available in production cars, and usually offer speedometer, tachometer, and navigation system displays. Night vision information is also displayed via HUD on certain General Motors, Honda, Toyota and Lexus vehicles. Other manufactures such as Audi, BMW, Citroën, Nissan, Mazda, Kia, Mercedes and Volvo currently offer some form of HUD system. Motorcycle helmet HUDs are also commercially available. Add-on HUD systems also exist, projecting the display onto a glass combiner mounted on the windshield. These systems have been marketed to police agencies for use with in-vehicle computers. The Eyes-on-the-Road-Benefit (ERB), also known as the Head-Up-Display-Advantage, is the term given to the purported advantages provided to motorists when driving using a Head- Up-Display (HUD) | https://en.wikipedia.org/wiki?curid=44739087 | 431,908 |
Human uses of birds White's 1951 "The Goshawk" describes the author's "monstrous and often cruel battles" to train his bird of prey, while Helen Macdonald's 2014 "H is for Hawk", which references White's book, tells how her obsession with the same species as a falconer helped her through the loss of her father. In music, birdsong has influenced composers and musicians in several ways: they can be inspired by birdsong; they can intentionally imitate bird song in a composition, as Vivaldi and Beethoven did, along with many later composers; they can incorporate recordings of birds into their works, first seen in the work of Ottorino Respighi; or as Beatrice Harrison did in 1924 with a nightingale, and David Rothenberg did in 2000 with a laughingthrush, they can duet with birds. At least two groups of scientists, namely Luis Felipe Baptista and Robin A. Keister in 2005, and Adam Tierney and colleagues in 2011, have argued that birdsong has a similar structure to music. Baptista and Keister argue that the way birds use variations of rhythm, relationships of musical pitch, and combinations of notes is somewhat musical, perhaps because some birds exploit variation in song to avoid monotony, or mimic other species. Tierney argues that the similar motor constraints on human and avian song drive these to have similar song structures, including "arch-shaped and descending melodic contours in musical phrases", long notes at the ends of phrases, and typically small differences in pitch between adjacent notes | https://en.wikipedia.org/wiki?curid=50262203 | 180,903 |
SabreTalk is a discontinued dialect of PL/I for the S/360 IBM mainframes running the TPF platform. was developed jointly by American Airlines, Eastern Air Lines and IBM. is known as PL/TPF (Programming Language for TPF). programs are still running in the British Airways Flight Operations system (FICO), although a commercially available automatic converter is being used to translate programs to C programs. Both the Reservations and Operations Support System (OSS) of Delta Air Lines were developed using both and IBM 360 Assembler. Although development is currently restricted to C++, the majority of Delta's programming platform remained in Sabretalk until recently in the 2010s. Because of the translator from to C and because it is no longer supported by the original developers, several companies are beginning the move away from to purely C-based programs. Code Sample: | https://en.wikipedia.org/wiki?curid=531030 | 269,659 |
Electron mobility The amount of deflection depends on the speed of the carrier and its proximity to the ion. The more heavily a material is doped, the higher the probability that a carrier will collide with an ion in a given time, and the smaller the mean free time between collisions, and the smaller the mobility. When determining the strength of these interactions due to the long-range nature of the Coulomb potential, other impurities and free carriers cause the range of interaction with the carriers to reduce significantly compared to bare Coulomb interaction. If these scatterers are near the interface, the complexity of the problem increases due to the existence of crystal defects and disorders. Charge trapping centers that scatter free carriers form in many cases due to defects associated with dangling bonds. Scattering happens because after trapping a charge, the defect becomes charged and therefore starts interacting with free carriers. If scattered carriers are in the inversion layer at the interface, the reduced dimensionality of the carriers makes the case differ from the case of bulk impurity scattering as carriers move only in two dimensions. Interfacial roughness also causes short-range scattering limiting the mobility of quasi-two-dimensional electrons at the interface. At any temperature above absolute zero, the vibrating atoms create pressure (acoustic) waves in the crystal, which are termed phonons. Like electrons, phonons can be considered to be particles | https://en.wikipedia.org/wiki?curid=760994 | 24,995 |
Evelyn Berezin (April 12, 1925 – December 8, 2018) was an American computer designer of the first computer-driven word processor. She also worked on computer-controlled systems for airline reservations. Berezin was born in the east Bronx in 1925 to Jewish immigrants from the Russian Empire, and attended Christopher Columbus High School. She started university at Hunter College in January 1941, studying Economics instead of the Physics she preferred because it was preferred as a subject for women at that time. After WWII started, new opportunities made the study of physics possible with a scholarship at New York University, plus free classes at both Hunter and Brooklyn Polytech during the war years. At the same time, she worked full-time during the day as an assistant in the Rheology Department of the Research Division of the International Printing Company (IPI). Going to university at night, she received her B.S. in physics in 1946. Berezin began graduate work at New York University, holding a fellowship from the United States Atomic Energy Commission. In 1951 she accepted a job with the Electronic Computer Corporation and began there as head of the Logic Design Department. Berezin was the only person doing the logic design for computers being developed by ECC. In 1957 ECC was purchased by Underwood Corporation (originally known as the Underwood Typewriter Company). Here, she designed a number of computers which were very general in structure but individual in specific application | https://en.wikipedia.org/wiki?curid=37344121 | 334,219 |
Conventional superconductor Conventional superconductors are materials that display superconductivity as described by BCS theory or its extensions. This is in contrast to unconventional superconductors, which do not. Conventional superconductors can be either type-I or type-II. Most elemental superconductors are conventional. Niobium and vanadium are type-II, while most other elemental superconductors are type-I. Critical temperatures of some elemental superconductors: Most compound and alloy superconductors are type-II materials. The most commonly used conventional superconductor in applications is a niobium-titanium alloy - this is a type-II superconductor with a superconducting critical temperature of 11 K. The highest critical temperature so far achieved in a conventional superconductor was 39 K (-234 °C) in magnesium diboride. BaKBiO is an unusual superconductor (a non-cuprate oxide) - but considered 'conventional' in the sense that the BCS theory applies. | https://en.wikipedia.org/wiki?curid=51070 | 58,433 |
Ribosomal frameshift When read from the beginning, these codons make sense to a ribosome and can be translated into amino acids (AA) under the vertebrate mitochondrial code: However, let's change the reading frame by starting one nucleotide downstream (effectively a "+1 frameshift" when considering the 0 position to be the initial position of A): Now, because of this +1 frameshifting, the DNA sequence is read differently. The different codon reading frame therefore yields different amino acids. In the case of a translating ribosome, a frameshift can either result in nonsense (a premature stop codon) after the frameshift, or the creation of a completely new protein after the frameshift. In the case where a frameshift results in nonsense, the NMD (nonsense-mediated mRNA decay) pathway may destroy the mRNA transcript, so frameshifting would serve as a method of regulating the expression level of the associated gene. In viruses this phenomenon may be programmed to occur at particular sites and allows the virus to encode multiple types of proteins from the same mRNA. Notable examples include HIV-1 (human immunodeficiency virus), RSV (Rous sarcoma virus) and the influenza virus (flu), which all rely on frameshifting to create a proper ratio of 0-frame (normal translation) and "trans-frame" (encoded by frameshifted sequence) proteins. Its use in viruses is primarily for compacting more genetic information into a shorter amount of genetic material | https://en.wikipedia.org/wiki?curid=14547183 | 175,507 |
Technology during World War II During the conflict, many new models of bolt-action rifles were produced as a result of lessons learned from the First World War with the designs of a number of bolt-action infantry rifles being modified in order to speed up production as well as to make the rifles more compact and easier to handle. Examples of bolt-action rifles that were used during World War II include the German Mauser Kar98k, the British Lee–Enfield No.4, and the Springfield M1903A3. During the course of World War II, bolt-action rifles and carbines were modified even further to meet new forms of warfare the armies of certain nations faced e.g. urban warfare and jungle warfare. Examples include the Soviet Mosin–Nagant M1944 carbine, which were developed by the Soviets as a result of the Red Army's experiences with urban warfare e.g. the Battle of Stalingrad, and the British Lee–Enfield No.5 carbine, that were developed for British and Commonwealth forces fighting the Japanese in South-East Asia and the Pacific. When World War II ended in 1945, the small arms that were used in the conflict still saw action in the hands of the armed forces of various nations and guerrilla movements during and after the Cold War era. Nations like the Soviet Union and the United States provided many surplus, World War II-era small arms to a number of nations and political movements during the Cold War era as a pretext to providing more modern infantry weapons | https://en.wikipedia.org/wiki?curid=326225 | 236,781 |
RNA origami Because the kissing-loop interactions and dovetail interactions are a half-turn or shorter, they do not create these topological issues. RNA and DNA nanostructures are used for the organization and coordination of important molecular processes. However, there exist several distinct differences between the fundamental structure and applications between the two. Although inspired by the DNA origami techniques established by Paul Rothemund, the process for is vastly different. is a much newer process than DNA origami; DNA origami has been studied while approximately a decade now, while the study of has only recently begun. In contrast to DNA origami, which involves chemically synthesizing the DNA strands and arranging the strands to form any shape desired with the aid of "staple strands", is made by enzymes and subsequently folds into pre-rendered shapes. RNA is able to fold into unique ways in complex structures due to a number of secondary structural motifs, such as conserved motifs and short structural elements. A major determinant for RNA topology is the secondary-structure interaction, which include motifs such as pseudoknots and kissing loops, adjacent helices stacking on one another, hairpin loops with bulge content, and coaxial stacks. This is largely a result of four different nucleotides: adenine (A), cytosine (C), guanine (G) and uracil (U), and ability to form non-canonical base pairs. There also exist more complex and longer-range RNA tertiary interactions | https://en.wikipedia.org/wiki?curid=55481097 | 262,724 |
Tripuhyite is an iron antimonate mineral with composition FeSbO. The name of the mineral comes from the locality of Tripuhy, Ouro Preto, Minas Gerais, Brazil, where it was discovered. Hussak and Prior first described the mineral tripuhyite as an oxide of iron and antimony, and assigned it the composition FeSbO. When a mineral with composition FeSbO was later discovered in Squaw Creek, New Mexico (US), it was considered erroneously as a new mineral and it was given the name "squawcreekite". However, other studies had shown that the original tripuhyite was also FeSbO. In 2002, the Commission on New Minerals and Mineral Names (CNMMN) of the International Mineralogical Association (IMA), approved the redefinition of tripuhyite as FeSbO and the discreditation of squawcreekite. FeSbO exhibits the rutile structure, with a tetragonal unit cell. The cations are octahedrally coordinated to oxygen anions, with the octahedra sharing edges along the c-direction. Fe(III) and Sb(V) cations are distributed in a disordered way over the octahedral sites. | https://en.wikipedia.org/wiki?curid=32944196 | 1,838 |
Real RAM In computing, especially computational geometry, a real RAM (random access machine) is a mathematical model of a computer that can compute with exact real numbers instead of the binary fixed point or floating point numbers used by most actual computers. The real RAM was formulated by Michael Ian Shamos in his 1978 Ph.D. dissertation. The "RAM" part of the real RAM model name stands for "random access machine". This is a model of computing that resembles a simplified version of a standard computer architecture. It consists of a stored program, a computer memory unit consisting of an array of cells, and a central processing unit with a bounded number of registers. Each memory cell or register can store a real number. Under the control of the program, the real RAM can transfer real numbers between memory and registers, and perform arithmetic operations on the values stored in the registers. The allowed operations typically include addition, subtraction, multiplication, and division, as well as comparisons, but not modulus or rounding to integers. The reason for avoiding integer rounding and modulus operations is that allowing these operations could give the real RAM unreasonable amounts of computational power, enabling it to solve PSPACE-complete problems in polynomial time. When analyzing algorithms for the real RAM, each allowed operation is typically assumed to take constant time | https://en.wikipedia.org/wiki?curid=20748371 | 117,607 |
Sight glass It was standard procedure to hold the coal scoop in front of the face while the other hand, holding the cap for protection, reached to turn off the valves at both ends of the glass. A reflex gauge is more complex in construction but can give a clearer distinction between gas (steam) and liquid (water). Instead of containing the media in a glass tube, the gauge consists of a vertically oriented slotted metal body with a strong glass plate mounted on the open side of the slot facing the operator. The rear of the glass, in contact with the media, has grooves moulded into its surface, running vertically. The grooves form a zig-zag pattern with 90° angles. Incident light entering the glass is refracted at the rear surface in contact with the media. In the region that is contact with the gas, most of the light is reflected from the surface of one groove to the next and back towards the operator, appearing silvery white. In the region that is in contact with the liquid, most of the light is refracted into the liquid causing this region to appear almost black to the operator. Well-known makes of reflex gauge are Clark-Reliance, IGEMA,TGI Ilmadur,Penberthy, Jerguson, Klinger, Cesare-Bonetti and Kenco. Due to the caustic nature of boiler anti-scaling treatments ("water softeners"), reflex gauges tend to become relatively rapidly etched by the water and lose their effectivess at displaying the liquid level | https://en.wikipedia.org/wiki?curid=4160674 | 366,322 |
Mitogen A mitogen is a peptide or small protein that induces a cell to begin cell division: mitosis. Mitogenesis is the induction (triggering) of mitosis, typically via a mitogen. The mechanism of action of a mitogen is that it triggers signal transduction pathways involving mitogen-activated protein kinase (MAPK), leading to mitosis. Mitogens act primarily by influencing a set of proteins which are involved in the restriction of progression through the cell cycle. The G1 checkpoint is controlled most directly by mitogens: further cell cycle progression does not need mitogens to continue. The point where mitogens are no longer needed to move the cell cycle forward is called the "restriction point" and depends on cyclins to be passed. One of the most important of these is TP53, a gene which produces a family of proteins known as p53. It, combined with the Ras pathway, downregulate cyclin D1, a cyclin-dependent kinase if they are not stimulated by the presence of mitogens. In the presence of mitogens, sufficient cyclin D1 can be produced. This process cascades onwards, producing other cyclins which stimulate the cell sufficiently to allow cell division. While animals produce internal signals that can drive the cell cycle forward, external mitogens can cause it to progress without these signals. Mitogens can be either endogenous or exogenous factors. Endogenous mitogens function to control cell division is a normal and necessary part of the life cycle of multicellular organisms | https://en.wikipedia.org/wiki?curid=1643827 | 85,426 |
Accountancy in Luxembourg Applicable accounting standards in Luxembourg are interchangeably referred to as either "Luxembourg GAAP" (i.e. Generally Accepted Accounting Principles) or "Luxembourg legal and regulatory requirements" (as often disclosed in the notes to the financial statements). Lux GAAP fall under the Law of 19 December 2002 as amended, sometimes referred to as "the Accounting Law". This law lays out specific accounting principles for all the main financial statement items. Lux GAAP are notable for the many options they afford, especially in terms of asset recognition. For instance, financial assets may be recognised at either 1) acquisition or production cost, 2) fair value (as allowed under the Law of 10 December 2010 which amended the 2002 Law), 3) the lower of cost or market value, depending on financial statement line items. Since theLaw of 30 July 2013 was passed, profits arising from revaluation of assets recognised at fair value may not be distributed as dividends. The Law also defines the accounting framework applicable under Lux GAAP, especially the principles relevant to the preparation of financial statements, especially the prudence principle under which unrealised gains are not recognised except where fair value is applicable, in stark contrast to rules under International Financial Reporting Standards (IFRS). Lawmakers in Luxembourg are especially keen on using doctrine from neighbouring France and Belgium whenever legal and regulatory requirements are unclear | https://en.wikipedia.org/wiki?curid=46664351 | 467,916 |
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