doc_id int32 18 2.25M | text stringlengths 245 2.96k | source stringlengths 38 44 | __index_level_0__ int64 18 2.25M |
|---|---|---|---|
1,112,243 | BLI and SPR are both dominant technologies in the label-free instruments market. Despite sharing some similarities in concept, there are significant differences between the two techniques. Micro-fluidic SPR relies on a closed architecture to transport samples to a stationary sensor chip (Figure 4). BLI instead utilizes an open system, shaking multiple wells on a plate to transport the sensors to the samples without need for micro-fluidics. Being a closed system, SPR's association and dissociation phases are limited by the technology's design. BLI's open plate design results in association and dissociation length limits determined by sample evaporation instead. SPR is easily reproducible due to its continuous flow microfluidics. BLI's multi well plate design allows for extremely high throughput in one batch. Assay configuration in BLI can, in stable conditions, allow for recovery of samples. Assay configuration in SPR allows for higher sensitivity. As a result, BLI results are often compared to SPR results for validation. | https://en.wikipedia.org/wiki?curid=28651121 | 1,111,677 |
834,099 | Crookes incorrectly suggested that the force was due to the pressure of light. This theory was originally supported by James Clerk Maxwell, who had predicted this force. This explanation is still often seen in leaflets packaged with the device. The first experiment to test this theory was done by Arthur Schuster in 1876, who observed that there was a force on the glass bulb of the Crookes radiometer that was in the opposite direction to the rotation of the vanes. This showed that the force turning the vanes was generated inside the radiometer. If light pressure were the cause of the rotation, then the better the vacuum in the bulb, the less air resistance to movement, and the faster the vanes should spin. In 1901, with a better vacuum pump, Pyotr Lebedev showed that in fact, the radiometer only works when there is low-pressure gas in the bulb, and the vanes stay motionless in a hard vacuum. Finally, if light pressure were the motive force, the radiometer would spin in the opposite direction, as the photons on the shiny side being reflected would deposit more momentum than on the black side, where the photons are absorbed. This results from conservation of momentum – the momentum of the reflected photon exiting on the light side must be matched by a reaction on the vane that reflected it. The actual pressure exerted by light is far too small to move these vanes, but can be measured with devices such as the Nichols radiometer. It is in fact possible to make the radiometer spin in the opposite direction by either heating it or putting it in a cold environment (like a freezer) in absence of light, when black sides become cooler than the white ones due to the black-body radiation. | https://en.wikipedia.org/wiki?curid=7021 | 833,650 |
697,388 | This technique is mostly used to produce coatings on structural materials. Such coatings provide protection against high temperatures (for example thermal barrier coatings for exhaust heat management), corrosion, erosion, wear; they can also change the appearance, electrical or tribological properties of the surface, replace worn material, etc. When sprayed on substrates of various shapes and removed, free-standing parts in the form of plates, tubes, shells, etc. can be produced. It can also be used for powder processing (spheroidization, homogenization, modification of chemistry, etc.). In this case, the substrate for deposition is absent and the particles solidify during flight or in a controlled environment (e.g., water). This technique with variation may also be used to create porous structures, suitable for bone ingrowth, as a coating for medical implants. | https://en.wikipedia.org/wiki?curid=6434629 | 697,024 |
2,244,385 | In North America, the US HOU project is led by the United States with support from the National Science Foundation, the Department of Defense, and the Department of Energy. In the US, HOU has developed and pilot-tested an educational program that enables high school students to request their own observations from professional observatories. Students download telescope images to their classroom computers and use the powerful HOU image processing software to visualize and analyze their data. The High school curriculum developed by HOU integrates many of the science and math topics and skills outlined in national standards into open-ended astronomical investigations. HOU has also developed activities and tools for middle school students and products for informal science education centers. The Lawrence Hall of Science at The University of California, Berkeley, is the educational center for the HOU project. | https://en.wikipedia.org/wiki?curid=20430586 | 2,243,114 |
1,245,426 | Solitons are now known to be ubiquitous in nature, from physics to biology. In 1986, Kruskal and Zabusky shared the Howard N. Potts Gold Medal from the Franklin Institute "for contributions to mathematical physics and early creative combinations of analysis and computation, but most especially for seminal work in the properties of solitons." In awarding the 2006 Steele Prize to Gardner, Greene, Kruskal, and Miura, the American Mathematical Society stated that before their work "there was no general theory for the exact solution of any important class of nonlinear differential equations." The AMS added, "In applications of mathematics, solitons and their descendants (kinks, anti-kinks, instantons, and breathers) have entered and changed such diverse fields as nonlinear optics, plasma physics, and ocean, atmospheric, and planetary sciences. Nonlinearity has undergone a revolution: from a nuisance to be eliminated, to a new tool to be exploited." | https://en.wikipedia.org/wiki?curid=1084397 | 1,244,752 |
991,937 | The electrochemical detector uses the principle of a fuel cell to generate an electrical current when the gas to be detected undergoes a chemical reaction. The generated current is precisely related to the amount of carbon monoxide in the immediate environment close to the sensor. Essentially, the electrochemical cell consists of a container, two electrodes, connection wires and an electrolyte, typically sulfuric acid. Carbon monoxide is oxidized at one electrode to carbon dioxide while oxygen is consumed at the other electrode. For carbon monoxide detection, the electrochemical cell has advantages over other technologies in that it has a highly accurate and linear output to carbon monoxide concentration, requires minimal power as it is operated at room temperature, and has a long lifetime, which typically is five years to ten years. This technology has become the dominant technology in the United States and in Europe. Test buttons only indicate the operational effectiveness of the battery, circuit and buzzer. The only way to fully test the operation of a CO alarm using an electrochemical cell is with a known source of calibrated test gas delivered in a shroud to maintain the concentration level for the test period. | https://en.wikipedia.org/wiki?curid=2930061 | 991,420 |
1,020,328 | In flash photography the light of the flash occurs too fast for the pupil to close, so much of the very bright light from the flash passes into the eye through the pupil, reflects off the fundus at the back of the eyeball and out through the pupil. The camera records this reflected light. The main cause of the red color is the ample amount of blood in the choroid which nourishes the back of the eye and is behind the retina. The blood in the retinal circulation is far less than in the choroid, and plays virtually no role. The eye contains several photostable pigments that all absorb in the short wavelength region, and hence contribute somewhat to the red eye effect. The lens cuts off deep blue and violet light, below 430 nm (depending on age), and macular pigment absorbs between 400 and 500 nm, but this pigment is located exclusively in the tiny fovea. Melanin, located in the retinal pigment epithelium (RPE) and the choroid, shows a gradually increasing absorption towards the short wavelengths. But blood is the main determinant of the red color, because it is completely transparent at long wavelengths and abruptly starts absorbing at 600 nm. The amount of red light emerging from the pupil depends on the amount of melanin in the layers behind the retina. This amount varies strongly between individuals. Light-skinned people with blue eyes have relatively low melanin in the fundus and thus show a much stronger red-eye effect than dark-skinned people with brown eyes. | https://en.wikipedia.org/wiki?curid=26491 | 1,019,801 |
63,331 | Since the Maxwell theory of light allows for all possible energies of electromagnetic radiation, most physicists assumed initially that the energy quantization resulted from some unknown constraint on the matter that absorbs or emits the radiation. In 1905, Einstein was the first to propose that energy quantization was a property of electromagnetic radiation itself. Although he accepted the validity of Maxwell's theory, Einstein pointed out that many anomalous experiments could be explained if the "energy" of a Maxwellian light wave were localized into point-like quanta that move independently of one another, even if the wave itself is spread continuously over space. In 1909 and 1916, Einstein showed that, if Planck's law regarding black-body radiation is accepted, the energy quanta must also carry momentum making them full-fledged particles. This photon momentum was observed experimentally by Arthur Compton, for which he received the Nobel Prize in 1927. The pivotal question then, was how to unify Maxwell's wave theory of light with its experimentally observed particle nature? The answer to this question occupied Albert Einstein for the rest of his life, and was solved in quantum electrodynamics and its successor, the Standard Model. (See ' and ', below.) | https://en.wikipedia.org/wiki?curid=23535 | 63,306 |
15,340 | In 2014, Poland planned to purchase 64 multirole combat aircraft from 2021 as part of its modernisation plans to replace the ageing fleet of Sukhoi Su-22M4 'Fitter-K' ground attack aircraft and Mikoyan MiG-29 'Fulcrum' fighters. On 23 November 2017, the Armament Inspectorate announced the acquisition process's start. By 22 December 2017, five entities had expressed interest in the procurement, referred to as "Harpia" (harpy eagle), including Saab AB with Gripen NG, Lockheed Martin with F-35, Boeing with F/A-18, Leonardo with Eurofighter Typhoon and Fights-On Logistics with second hand F-16s. In May 2019, the Polish Defense Ministry formally requested to buy 32 F-35A for $4 billion with delivery from 2023 to 2026 with an option for 32 more from 2027. | https://en.wikipedia.org/wiki?curid=87577 | 15,335 |
1,778,324 | The earliest ceramics of the region's Woodland Culture (1000 BCE–1250 CE) is called the Half-Moon Ware. There are now two known types of early ceramics of the Woodland Culture. It has been suggested that oval or circular structures were used as houses. In 1986, Grantz attempted to test in Fayette County, Pennsylvania several post mold arcs for a pattern to confirm the suggestion of early village houses. Despite earnest effort, it was not confirmed. The Middle (1–500 CE) and Late Woodland (500–1000 CE) Periods for the Northern Panhandle of West Virginia would include the Mid-western cultures of primarily Adena and Late Hopewell (1–500 CE) from McConaughy's (2000) research. "Nebulas" is a term to describe late Hopewellian—localizing societies. Later (650 CE), some Woodland would be alongside very Late Adena (46PU2) and assimilating on the Greater Kanawhan region. Burial ceremonials and mound construction gradually became smaller which has phased out by the end of the Woodland period. However, because tobacco was probably being grown and used, McConaughy in 1990 suggests the development of complex society. Early Woodland peoples lived a more settled existence. | https://en.wikipedia.org/wiki?curid=17254851 | 1,777,322 |
1,742,585 | From the start of the race, defending champion Olga Kaniskina took the lead, only Liu Hong would go with her. The two opened up a big gap with a chase pack of a Guatemalan, the other 2 Russians, other 2 Chinese. By the end of 8K the pack began to lose walkers, Mirna Ortíz and Johanna Jackson were disqualified, and Liu began to lose contact, Kaniskina off on her own. Shortly after the half way mark, the pack was down to Elena Lashmanova and Anisya Kirdyapkina leading Xiuzhi Lu and Qieyang Shijie An hour into the race and Lu began to lose contact, Lashmanova, Kirdyapkina and Qieyang chasing and then swallowing up Liu. By 14 km Kaniskina had a 33-second lead. Almost unnoticeable, the gap between Kaniskina and the chasers had come down to 24 seconds at 16 km, Kirdyapkina and then Liu struggling to stay with the group. After another 2K lap, the gap was down to 17 seconds at 18 km, still seemingly insurmountable with just one lap to go. With Kaniskina looking strong, the gap kept falling. Kaniskina started to show the strain, as the pass became inevitable she began the most pronounced arm swing trying to find that last bit of speed, but it wasn't enough. Less than 200 metres from the finish Lashmanova went by Kaniskina and on to the gold carpet. Lashmanova finished with a 1:25:02 world record. Broken Kaniskina finished 7 seconds back, just a second slower than the previous world record. Qieyang happily finished another 7 seconds later for bronze. After the finish, Kaniskina was barely able to walk, while a fresh Lashmanova celebrated her victory. | https://en.wikipedia.org/wiki?curid=31816302 | 1,741,601 |
2,005,516 | David Deming (born 1954), an American geologist and geophysicist, is an associate professor of Arts and Sciences at the University of Oklahoma in Norman. He graduated from North Central High School in Indianapolis, Indiana in 1972. He then attended Indiana University Bloomington, graduating in 1983 with a BS degree in geology, and received a Ph.D in geophysics from the University of Utah in 1988. Prior to his arrival at the University of Oklahoma in 1992, Deming held a National Research Council postdoctoral fellowship at the U.S. Geological Survey in California. From 1992 through 2003, Deming was an assistant and associate professor in the School of Geology and Geophysics at the University of Oklahoma. An outspoken and controversial professor, Deming was involved in two major disputes with the OU administration, one leading to a lawsuit. Deming is the author of more than thirty research papers and the textbook "Introduction to Hydrogeology". He is an associate editor for the academic journals "Petroleum Geoscience" and "Ground Water", and is an adjunct faculty member at two conservative think tanks, the Oklahoma Council of Public Affairs and the National Center for Policy Analysis | https://en.wikipedia.org/wiki?curid=10043078 | 2,004,367 |
813,304 | In the decade following 1995, Rose-Hulman's growth was aided by a major fundraising campaign, "Vision to be the Best". Originally a $100 million campaign over ten years, it met its goal in half the time. The goal was extended to $200 million, and by the end of the campaign in June 2004, over $250 million had been raised. In 1997, many physical changes came to the Rose-Hulman campus. Due to a gift from the F._W._Olin_Foundation, an expansion of Olin Hall known as the Olin Advanced Learning Center opened. Additionally, The John T Myers Center for Technological Research opened, with space for research labs, presentation rooms, classrooms, and academic offices. Shook Field House was replaced with the $20 million Sports and Recreation Center, which the National Football League's Indianapolis Colts used for their summer training camp from 1999 to 2010. In 2002, Hatfield Hall, a theater and alumni center, was opened. | https://en.wikipedia.org/wiki?curid=61263 | 812,871 |
2,117,029 | There were a number of considerations regarding the purpose and concept for the school. Wass de Czege thought that certain officers should receive a "broad, deep military education in the science and art of war." Graduates would not be a "privileged elite", but would "create a multiplier effect in all areas of Army competence." But there were varying ideas about what product the course should generate. For example, the commandant of the Command and General Staff School, Lieutenant General Jack N. Merritt "wanted sort of a junior Henry Kissinger kind of course," whereas the deputy commandant, Major General Crosbie Saint Jr. envisioned a "super dooper tacticians course." What was developed, and eventually approved, by both officers was "a broad-based curriculum that began with military theory and ended with courses on preparing for war—a logical progression through the complexities of warfare". | https://en.wikipedia.org/wiki?curid=33700588 | 2,115,811 |
224,914 | During this period in Moscow Fredrich Tsander, a scientist and inventor was designing and building liquid rocket engines which ran on compressed air and gasoline. Tsander used it to investigate high-energy fuels including powdered metals mixed with gasoline. In September 1931 Tsander formed the Moscow based 'Group for the Study of Reactive Motion', better known by its Russian acronym “GIRD”. In May 1932, Sergey Korolev replaced Tsander as the head of GIRD. Mikhail Tikhonravov launched the first Soviet liquid propelled rocket, fueled by liquid oxygen and jellied gasoline, the GIRD-9, took place on 17 August 1933, which reached an altitude of . In January 1933 Tsander began development of the GIRD-X rocket. This design burned liquid oxygen and gasoline and was one of the first engines to be regeneratively cooled by the liquid oxygen, which flowed around the inner wall of the combustion chamber before entering it. Problems with burn-through during testing prompted a switch from gasoline to less energetic alcohol. The final missile, long by in diameter, had a mass of , and it was anticipated that it could carry a payload to an altitude of . The GIRD X rocket was launched on 25 November 1933 and flew to a height of 80 meters. | https://en.wikipedia.org/wiki?curid=520402 | 224,799 |
1,975,184 | Immediately after financing and incorporation, they offered founder stock and hired IC designers George Erdi from Fairchild and Dan Dooley from TRW Microelectronics. They also hired Jerry Bresee, a chief process engineer from Tektronix, who developed a semiconductor process far superior to what they were able to access from the Fairchild R&D processing services department, with the exception of nitride passivation for low 1/f noise, a technology known by the founders from Fairchild. In 1969 Dooley designed the first fully integrated D/A converter (DAC), the 6-bit DAC01, using diffused resistors. He recruited his thin film technician with precision resistor fabrication skills that were essential for improving the accuracy of DACs, which became the biggest-selling type of product that helped launch the company. Semiconductor and materials engineer Wadie Khadder was hired with founder stock from Fairchild to support Bresee in both semiconductor process engineering and also the critical precision thin film technology initially needed for producing high accuracy 2-chip D/A converters. | https://en.wikipedia.org/wiki?curid=9406926 | 1,974,047 |
1,638,040 | Parvovirus genomes have distinct starting points of replication that contain palindromic DNA sequences. These sequences are able to alternate between inter- and intrastrand basepairing throughout replication, and they serve as self-priming telomeres at each end of the genome. They also contain two key sites necessary for replication used by the initiator protein: a binding site and a cleavage site. Telomere sequences have significant complexity and diversity, suggesting that they perform additional functions for many species. In MVM, for example, the left-end hairpin contains binding sites for transcription factors that modulate gene expression from an adjacent promoter. For AAV, the hairpins can bind to MRE11/Rad50/NBS1 (MRN) complexes and Ku70/80 heterodimers, which are involved in sensing and repairing DNA. In general, however, they have the same basic structure: imperfect palindromes in which a fully or primarily basepaired region terminates into an axial symmetry. These palindromes can fold into a variety of structures such as a Y-shaped structure and a cruciform-shaped structure. During replication, the termini act as hinges in which the imperfectly basepaired or partial cruciform regions surrounding the axis provide a favorable environment for unfolding and refolding of the hairpin. | https://en.wikipedia.org/wiki?curid=66387043 | 1,637,115 |
1,273,859 | Urban Air Mobility (UAM) is the use of small, highly automated aircraft to carry passengers or cargo at lower altitudes in urban and suburban areas which have been developed in response to traffic congestion. It usually refers to existing and emerging technologies such as traditional helicopters, vertical-takeoff-and-landing aircraft (VTOL), electrically propelled, vertical-takeoff-and-landing aircraft (eVTOL), and unmanned aerial vehicles (UAVs). These aircraft are characterized by the use of multiple electric-powered rotors or fans for lift and propulsion, along with fly-by-wire systems to control them. Inventors have explored urban air mobility concepts since the early days of powered flight. However, advances in materials, computerized flight controls, batteries and electric motors improved innovation and designs beginning in the late 2010s. Most UAM proponents envision that the aircraft will be owned and operated by professional operators, as with taxis, rather than by private individuals. | https://en.wikipedia.org/wiki?curid=51649142 | 1,273,167 |
389,247 | The University of Houston hosts a variety of theatrical performances, concerts, lectures, and events. It has more than 500 student organizations and 17 intercollegiate sports teams. Annual UH events and traditions include The Cat's Back, Homecoming, and Frontier Fiesta. The university's varsity athletic teams, known as the Houston Cougars, are members of the American Athletic Conference and compete in the NCAA Division I in all sports. In 2021, the university received and accepted an invitation to join the Big 12 Conference. The football team regularly makes bowl game appearances, and the men's basketball team has made 23 appearances in the NCAA Division I Tournament—including six Elite Eight and Final Four appearances. The men's golf team has won 16 national championships—the most in NCAA history. In 2022, UH's men's track and field team earned its seventh Indoor Conference Championship title, and its swimming and diving team defended its American Athletic Conference title for the sixth straight season. | https://en.wikipedia.org/wiki?curid=490310 | 389,052 |
97,488 | The mechanisms used to evade the adaptive immune system are more complicated. The simplest approach is to rapidly change non-essential epitopes (amino acids and/or sugars) on the surface of the pathogen, while keeping essential epitopes concealed. This is called antigenic variation. An example is HIV, which mutates rapidly, so the proteins on its viral envelope that are essential for entry into its host target cell are constantly changing. These frequent changes in antigens may explain the failures of vaccines directed at this virus. The parasite "Trypanosoma brucei" uses a similar strategy, constantly switching one type of surface protein for another, allowing it to stay one step ahead of the antibody response. Masking antigens with host molecules is another common strategy for avoiding detection by the immune system. In HIV, the envelope that covers the virion is formed from the outermost membrane of the host cell; such "self-cloaked" viruses make it difficult for the immune system to identify them as "non-self" structures. | https://en.wikipedia.org/wiki?curid=14958 | 97,447 |
1,111,513 | Research in superhydrophobicity recently accelerated with a letter that reported man-made superhydrophobic samples produced by allowing alkylketene dimer (AKD) to solidify into a nanostructured fractal surface. Many papers have since presented fabrication methods for producing superhydrophobic surfaces including particle deposition, sol-gel techniques, plasma treatments, vapor deposition, and casting techniques. Current opportunity for research impact lies mainly in fundamental research and practical manufacturing. Debates have recently emerged concerning the applicability of the Wenzel and Cassie-Baxter models. In an experiment designed to challenge the surface energy perspective of the Wenzel and Cassie-Baxter model and promote a contact line perspective, water drops were placed on a smooth hydrophobic spot in a rough hydrophobic field, a rough hydrophobic spot in a smooth hydrophobic field, and a hydrophilic spot in a hydrophobic field. Experiments showed that the surface chemistry and geometry at the contact line affected the contact angle and contact angle hysteresis, but the surface area inside the contact line had no effect. An argument that increased jaggedness in the contact line enhances droplet mobility has also been proposed. One method to experimentally measure the jaggedness in the contact line uses low melting temperature metal melted and deposited onto micro/nano structured surfaces. When the metal cools and solidifies, it is removed from the surface. flipped, and inspected for contact line micro geometry. | https://en.wikipedia.org/wiki?curid=3169559 | 1,110,947 |
1,042,767 | Earlier in 2014, officials with the Goddard Space Flight Center said the NASA Deep Space Network equipment necessary to transmit signals to the spacecraft had been decommissioned in 1999, and was too expensive to replace. However, project members were able to find documentation for the original equipment and were able to simulate the complex modulator/demodulator electronics using modern software-defined radio (SDR) techniques and open-source programs from the GNU Radio project. They obtained the needed hardware, an off-the-shelf SDR transceiver, and power amplifier, and installed it on the Arecibo dish antenna on 19 May 2014. Once they gained control of the spacecraft, the capture team planned to shift the primary ground station to the dish located at Morehead State University Space Science Center of Kentucky. The dish antenna in Bochum Observatory, Germany, would be a support station. | https://en.wikipedia.org/wiki?curid=2233078 | 1,042,224 |
400,024 | The FME(C)A is a design tool used to systematically analyze postulated component failures and identify the resultant effects on system operations. The analysis is sometimes characterized as consisting of two sub-analyses, the first being the failure modes and effects analysis (FMEA), and the second, the criticality analysis (CA). Successful development of an FMEA requires that the analyst include all significant failure modes for each contributing element or part in the system. FMEAs can be performed at the system, subsystem, assembly, subassembly or part level. The FMECA should be a living document during development of a hardware design. It should be scheduled and completed concurrently with the design. If completed in a timely manner, the FMECA can help guide design decisions. The usefulness of the FMECA as a design tool and in the decision-making process is dependent on the effectiveness and timeliness with which design problems are identified. Timeliness is probably the most important consideration. In the extreme case, the FMECA would be of little value to the design decision process if the analysis is performed after the hardware is built. While the FMECA identifies all part failure modes, its primary benefit is the early identification of all critical and catastrophic subsystem or system failure modes so they can be eliminated or minimized through design modification at the earliest point in the development effort; therefore, the FMECA should be performed at the system level as soon as preliminary design information is available and extended to the lower levels as the detail design progresses. | https://en.wikipedia.org/wiki?curid=981631 | 399,825 |
1,356,031 | Grants have been distributed across the different states even though the perceived risk is not evenly spread, leading to accusations of pork barrel politics that directs money and jobs towards marginal voting areas. The Urban Areas Security Initiative grant program has been particularly controversial, with the 2006 infrastructure list covering 77,000 assets, including a popcorn factory and a hot dog stand. The 2007 criteria were reduced to 2,100 and now those facilities must make a much stronger case to become eligible for grants. While well-intentioned, some of the results have also been questioned regarding claims of poorly designed and intrusive security theater that distracts attention and money from more pressing issues or creates damaging side effects. | https://en.wikipedia.org/wiki?curid=3698136 | 1,355,283 |
457,333 | Giving a more precise explanation of this discrepancy in D receptor has been attempted by a significant minority. Radioligand imaging measurements involve the monomer and dimer ratio, and the 'cooperativity' model. Cooperativitiy is a chemical function in the study of enzymes. Dopamine receptors interact with their own kind, or other receptors to form higher order receptors such as dimers, via the mechanism of cooperativity. Philip Seeman has said: "In schizophrenia, therefore, the density of [11C] methylspiperone sites rises, reflecting an increase in monomers, while the density of [11C] raclopride sites remains the same, indicating that the total population of D monomers and dimers does not change." (In another place Seeman has said methylspiperone possibly binds with dimers) With this difference in measurement technique in mind, the above-mentioned meta-analysis uses results from 10 different ligands. Exaggerated ligand binding results such as SDZ GLC 756 (as used in the figure) were explained by reference to this monomer-dimer equilibrium. | https://en.wikipedia.org/wiki?curid=599614 | 457,110 |
1,910,975 | The limitations of electron microscopy in the study of lipid structures deal primarily with sample preparation. Most electron microscopes require the sample to be under vacuum, which is incompatible with hydration at room temperature. To surmount this problem, samples can be imaged under cryogenic conditions with the associated water frozen, or a metallic negative can be made from a frozen sample. It is also typically necessary to stain the bilayer with a heavy metal compound such as osmium tetroxide or uranyl acetate because the low atomic weight constituents of lipids (carbon, nitrogen, phosphorus, etc.) offer little contrast compared to water. If a Transmission electron microscope (TEM) is being used, it is also necessary to cut or polish the sample into a very thin (<1 micrometre) sheet, which can be difficult and time-consuming. Scanning Electron Microscopy (SEM) does not require this step, but cannot offer the same resolution as TEM. Both methods are surface-sensitive techniques and cannot reveal information about deeply buried structures. | https://en.wikipedia.org/wiki?curid=21453848 | 1,909,876 |
314,423 | Malnutrition and poor nutritional status is an area of concern, affecting 12% to 50% of hospitalized elderly patients and 23% to 50% of institutionalized elderly patients living in long-term care facilities such as assisted living communities and skilled nursing facilities. As malnutrition can occur due to a combination of physiologic, pathologic, psychologic and socioeconomic factors, it can be difficult to identify effective interventions. Physiologic factors include reduced smell and taste, and a decreased metabolic rate affecting nutritional food intake. Unintentional weight loss can result from pathologic factors, including a wide range of chronic diseases that affect cognitive function, directly impact digestion (e.g. poor dentition, gastrointestinal cancers, gastroesophageal reflux disease) or may be managed with dietary restrictions (e.g. congestive heart failure, diabetes mellitus, hypertension). Psychologic factors include conditions including depression, anorexia, and grief. | https://en.wikipedia.org/wiki?curid=436825 | 314,254 |
533,674 | The device consists of a gear known as a ratchet that rotates freely in one direction but is prevented from rotating in the opposite direction by a pawl. The ratchet is connected by an axle to a paddle wheel that is immersed in a fluid of molecules at temperature formula_1. The molecules constitute a heat bath in that they undergo random Brownian motion with a mean kinetic energy that is determined by the temperature. The device is imagined as being small enough that the impulse from a single molecular collision can turn the paddle. Although such collisions would tend to turn the rod in either direction with equal probability, the pawl allows the ratchet to rotate in one direction only. The net effect of many such random collisions would seem to be that the ratchet rotates continuously in that direction. The ratchet's motion then can be used to do work on other systems, for example lifting a weight ("m") against gravity. The energy necessary to do this work apparently would come from the heat bath, without any heat gradient (i.e. the motion leeches energy from the temperature of the air). Were such a machine to work successfully, its operation would violate the second law of thermodynamics, one form of which states: "It is impossible for any device that operates on a cycle to receive heat from a single reservoir and produce a net amount of work." | https://en.wikipedia.org/wiki?curid=432276 | 533,395 |
848,901 | The existing low-voltage network, and local transformers in particular, may not have enough capacity to handle the additional power load that might be required in certain areas with high plug-in electric car concentrations. As recharging a single electric-drive car could consume three times as much electricity as a typical home, overloading problems may arise when several vehicles in the same neighborhood recharge at the same time, or during the normal summer peak loads. To avoid such problems, utility executives recommend owners to charge their vehicles overnight when the grid load is lower or to use smarter electric meters that help control demand. When market penetration of plug-in electric vehicles begins to reach significant levels, utilities will have to invest in improvements for local electrical grids in order to handle the additional loads related to recharging to avoid blackouts due to grid overload. Also, some experts have suggested that by implementing variable time-of-day rates, utilities can provide an incentive for plug-in owners to recharge mostly overnight when rates are lower. | https://en.wikipedia.org/wiki?curid=23840623 | 848,451 |
2,106,091 | In 1867, Morel was active in British North Borneo for the Labuan Coal Company, building railways and sinking mining shafts, living at Labuan island, when he was invited to Japan by British envoy Sir Harry Parkes. During his short assignment he made significant proposals to the Japanese government regarding engineering administration and education. The government established the Ministry of Public Works in December 1870 on his advice to integrate the introduction of foreign technologies and their application. Morel designed Japan's first railway, connecting Shimbashi Station in Tokyo with Sakuragichō Station in Yokohama. The locomotives and rails were imported from England. Through discussions with Itō Hirobumi and Ōkuma Shigenobu, Morel advised on what industries and technologies were necessary for Japan to build railways, and through discussions Japan's standard gauge of was established. During poor weather when work on the line was not possible, he took his Japanese engineers and surveyors into his house for lectures. | https://en.wikipedia.org/wiki?curid=28955738 | 2,104,878 |
1,388,283 | The power per thrust required for a perfectly collimated output beam is 300 MW/N (half this if it can be reflected off the craft); very high energy density power sources would be required to provide reasonable thrust without unreasonable weight. The specific impulse of a photonic rocket is harder to define, since the output has no (rest) mass and is not expended fuel; if we take the momentum per inertia of the photons, the specific impulse is just "c", which is impressive. However, considering the mass of the source of the photons, e.g., atoms undergoing nuclear fission, brings the specific impulse down to 300 km/s ("c"/1000) or less; considering the infrastructure for a reactor (some of which also scales with the amount of fuel) reduces the value further. Finally, any energy loss not through radiation that is redirected precisely to aft but is instead conducted away by engine supports, radiated in some other direction, or lost via neutrinos or so will further degrade the efficiency. If we were to set 80% of the mass of the photon rocket = fissionable fuel, and recognizing that nuclear fission converts about 0.10% of the mass into energy: then if the photon rocket masses 300,000 kg then 240,000 kg of that is atomic fuel. Therefore, the fissioning of all of the fuel will result in the loss of just 240 kg of mass. Then 300,000/299,760 kg = an "m"/"m" of 1.0008. Using the rocket equation, we find "v" = ln 1.0008 × "c" where "c" = 299,792,458 m/s. | https://en.wikipedia.org/wiki?curid=37851 | 1,387,515 |
1,154,810 | From 1967 to 1995, PTB operated the Experimental and Research Reactor Braunschweig. This reactor served in particular as neutron source for fundamental research, not for the investigation of nuclear energy. PTB dealt with this controversial subject from 1977 to 1989, above all due to the fact that the task "long-term management and disposal of radioactive waste" had been assigned to it. Later on, this field of work passed over to the ″Bundesamt für Strahlenschutz″ (Federal Office for Radiation Protection) after same had been newly established. Today, PTB’s Division 6 deals with ionizing radiation in general. This also includes a highly sensitive trace survey station for radionuclides which has been measuring radioactive substances in ground-level air for meanwhile more than 50 years. | https://en.wikipedia.org/wiki?curid=336112 | 1,154,200 |
75,918 | Ferdinand de Saussure (1857–1913), the "father" of modern linguistics, proposed a dualistic notion of signs, relating the "signifier" as the form of the word or phrase uttered, to the "signified" as the mental concept. According to Saussure, the sign is completely arbitrary—i.e., there is no necessary connection between the sign and its meaning. This sets him apart from previous philosophers, such as Plato or the scholastics, who thought that there must be some connection between a signifier and the object it signifies. In his "Course in General Linguistics", Saussure credits the American linguist William Dwight Whitney (1827–1894) with insisting on the arbitrary nature of the sign. Saussure's insistence on the arbitrariness of the sign also has influenced later philosophers and theorists such as Jacques Derrida, Roland Barthes, and Jean Baudrillard. Ferdinand de Saussure coined the term "sémiologie" while teaching his landmark "Course on General Linguistics" at the University of Geneva from 1906 to 1911. Saussure posited that no word is inherently meaningful. Rather a word is only a "signifier." i.e., the representation of something, and it must be combined in the brain with the "signified", or the thing itself, in order to form a meaning-imbued "sign." Saussure believed that dismantling signs was a real science, for in doing so we come to an empirical understanding of how humans synthesize physical stimuli into words and other abstract concepts. | https://en.wikipedia.org/wiki?curid=29301 | 75,889 |
440,758 | In other experiments that spring and summer, Lodge put a series of spark gaps along two 29 meter (95') long wires and noticed he was getting a very large spark in the gap near the end of the wires, which seemed to be consistent with the oscillation wavelength produced by the Leyden jar meeting with the wave being reflected at the end of the wire. In a darkened room, he also noted a glow at intervals along the wire at one half wavelength intervals. He took this as evidence that he was generating and detecting Maxwell's electromagnetic waves. While traveling on a vacation to the Tyrolean Alps in July 1888, Lodge read in a copy of "Annalen der Physik" that Heinrich Hertz in Germany had been conducting his own electromagnetic research, and that he had published a series of papers proving the existence of electromagnetic waves and their propagation in free space. Lodge presented his own paper on electromagnetic waves along wires in September 1888 at the British Science Association meeting in Bath, England, adding a postscript acknowledging Hertz's work and saying: "The whole subject of electrical radiation seems working itself out splendidly." | https://en.wikipedia.org/wiki?curid=348879 | 440,543 |
360,935 | . Strong imbalances or disruptions to neurotransmitter systems have been associated with many diseases and mental disorders. These include Parkinson's, depression, insomnia, Attention Deficit Hyperactivity Disorder (ADHD), anxiety, memory loss, dramatic changes in weight and addictions. Chronic physical or emotional stress can be a contributor to neurotransmitter system changes. Genetics also plays a role in neurotransmitter activities. Apart from recreational use, medications that directly and indirectly interact with one or more transmitter or its receptor are commonly prescribed for psychiatric and psychological issues. Notably, drugs interacting with serotonin and norepinephrine are prescribed to patients with problems such as depression and anxiety—though the notion that there is much solid medical evidence to support such interventions has been widely criticized. Studies shown that dopamine imbalance has an influence on multiple sclerosis and other neurological disorders. | https://en.wikipedia.org/wiki?curid=21865 | 360,746 |
1,566,458 | Drake was an elite engineer as well as talented craftsman throughout his lifetime. Drake first engineered the simulation for his windsurfer concept on paper then crafted nearly all of the windsurfer prototype components by hand in his Santa Monica, California home garage in January 1967. He built the wishbone boom, daggerboard and mast foot from laminated teak wood. He designed and built a custom wood press jig for shaping the curve into the wishbone boom. His universal joint design was created by reconfiguring a commercially available sailboat swivel joint; constructed from heavy duty marine stainless steel with a teflon core component. Drake custom engineered the first sail, which was made of Dacron sail cloth. It formed a triangular Bermuda rig cut and was sewn by sail maker Bob Broussard. The custom board, the size of a large tandem surfboard, was designed by Drake and shaped from an oversized foam blank by shaper Gary Seaman at the Santa Monica-based surfboard factory of Con Surfboards. A repurposed hollow fiberglass mast from a small racing dingy was used to support the sail. Schweitzer's contribution to the project was primarily financial and non-technical. Drake was the concept's design engineer who knew what specifications the sail craft required and what materials were needed to build it. Drake instructed Schweitzer to purchase specific items and where to go to purchase those items, including the large foam tandem surfboard blank, and the hollow fiberglass mast. | https://en.wikipedia.org/wiki?curid=23117343 | 1,565,571 |
403,147 | For example, Rogers discussed a situation in Peru involving the implementation of boiling drinking water to improve health and wellness levels in the village of Los Molinas. The residents had no knowledge of the link between sanitation and illness. The campaign worked with the villagers to try to teach them to boil water, burn their garbage, install latrines and report cases of illness to local health agencies. In Los Molinas, a stigma was linked to boiled water as something that only the "unwell" consumed, and thus, the idea of healthy residents boiling water prior to consumption was frowned upon. The two-year educational campaign was considered to be largely unsuccessful. This failure exemplified the importance of the roles of the communication channels that are involved in such a campaign for social change. An examination of diffusion in El Salvador determined that there can be more than one social network at play as innovations are communicated. One network carries information and the other carries influence. While people might hear of an innovation's uses, in Rogers' Los Molinas sanitation case, a network of influence and status prevented adoption. | https://en.wikipedia.org/wiki?curid=1123434 | 402,947 |
1,044,337 | The American botanist Asa Gray used the name "theistic evolution" for his point of view, presented in his 1876 book "Essays and Reviews Pertaining to Darwinism". He argued that the deity supplies beneficial mutations to guide evolution. St George Jackson Mivart argued instead in his 1871 "On the Genesis of Species" that the deity, equipped with foreknowledge, sets the direction of evolution by specifying the (orthogenetic) laws that govern it, and leaves species to evolve according to the conditions they experience as time goes by. The Duke of Argyll set out similar views in his 1867 book "The Reign of Law". According to the historian Edward Larson, the theory failed as an explanation in the minds of late 19th century biologists as it broke the rules of methodological naturalism which they had grown to expect. Accordingly, by around 1900, biologists no longer saw theistic evolution as a valid theory. In Larson's view, by then it "did not even merit a nod among scientists." In the 20th century, theistic evolution could take other forms, such as the orthogenesis of Teilhard de Chardin. | https://en.wikipedia.org/wiki?curid=53955838 | 1,043,793 |
51,567 | Southern Iraq during Akkadian period seems to have been approaching its modern rainfall level of less than per year, with the result that agriculture was totally dependent upon irrigation. Before the Akkadian period, the progressive salinisation of the soils, produced by poorly drained irrigation, had been reducing yields of wheat in the southern part of the country, leading to the conversion to more salt-tolerant barley growing. Urban populations there had peaked already by 2,600 BC, and demographic pressures were high, contributing to the rise of militarism apparent immediately before the Akkadian period (as seen in the Stele of the Vultures of Eannatum). Warfare between city states had led to a population decline, from which Akkad provided a temporary respite. It was this high degree of agricultural productivity in the south that enabled the growth of the highest population densities in the world at this time, giving Akkad its military advantage. | https://en.wikipedia.org/wiki?curid=1566 | 51,547 |
1,560,088 | Eukaryotic cells can communicate directly with each other through cell–cell contact or at distance by secreting soluble factors such as hormones, growth factors, cytokines and chemokines. Both RNA and mRNAs can be functionally transferred from a donor to a recipient cell via membrane-derived vesicles called exosomes. Similarly to hormones, miRNAs are released into the circulation (called circulating miRNAs or c-miRNAs), to affect cells throughout the organism. The c-miRNAs are transported by exosomes, high-/low-density lipoproteins, apoptotic bodies, and RNA-binding proteins. A bout of exercise increases c-miR-223 levels in the circulation in young healthy men, while lack of miR-223 leads to hippocampal-dependent memory deficits and neuronal cell death. Likely arising from different mechanisms, both acute exercise and chronic endurance training have been shown to robustly modify the miRNA signature of human plasma. | https://en.wikipedia.org/wiki?curid=42663845 | 1,559,202 |
547,408 | Offered over 18 months, the Rotman Global Executive MBA program immerses mid-to-senior executives in core business disciplines from a global perspective. The program, supported by well-known post-secondary institutions in Brazil, India, Hong Kong and China, brings participants together in cross-cultural study teams to gain business experience in the world's main economic regions. Candidates are mid-to-senior level professionals from industry, providers and service delivery organizations, consulting firms, public agencies, science, and payers in the healthcare and life sciences sector around the world who seek to advance their leadership careers. | https://en.wikipedia.org/wiki?curid=630291 | 547,121 |
1,628,601 | Limiting biotic homogenization ultimately relies on limiting its sources: species invasion and extinction. Because these are largely rooted in human activity, if conservation is to be successful, it is necessary to reduce the degree to which people cause invasions and extinctions. Since biotic homogenization is still a relatively new area of study, increased education about both its mechanism and impact could potentially be effective as well. If we are to improve our understanding of the field, it is necessary to increase the scale of our knowledge of its spatial, temporal, geographic, and taxonomic components. There is a disproportionate number of studies in taxonomic homogenization, with relatively few in functional homogenization, which could have greater ecological implications. Increased study into functional homogenization could give insight into conservation needs. These gaps in the literature may, however, soon be filled. The study of homogenization is increasingly gaining attention in ecological circles, with the number of studies quantifying its effects increasing exponentially between the years of 2000 and 2015. | https://en.wikipedia.org/wiki?curid=59627314 | 1,627,682 |
1,700,265 | It has been developed by DRDO's laboratory Aeronautical Development Establishment (ADE). Ulka was earlier simply known as MT (Missile Target). It has been designed to be launched from subsonic or supersonic aircraft by means of an ejector release unit. It performed missions between 50 m to 13,000 m altitude at speeds ranging from 0.7 to 1.4 Mach with a rocket motor. It is able to simulate the speed and altitude characteristics of approaching, receding or crossing of a variety of aircraft using false radar signatures. It is used for defensive training of surface-to-air missile crews against anti-ship missiles and for development testing and evaluation of air defense systems. It can be air-launched by a variety of aircraft. It is the first Indian aerial vehicle to incorporate a canard configuration. It has been succeeded by Lakshya PTA. | https://en.wikipedia.org/wiki?curid=30367403 | 1,699,311 |
1,237,176 | Other British companies developed products for gate array design and fabrication. Qudos Limited, a spin-off from Cambridge University, offered a chip design product called Quickchip available for VAX and MicroVAX II systems and as a complete $11,000 turnkey solution, providing a suite of tools broadly similar to those of Ferranti's products including automatic layout, routing, rule checking and simulation functionality for the design of gate arrays. Qudos employed electron beam lithography, etching designs onto Ferranti ULA devices that formed the physical basis of these custom chips. Typical prototype production costs were stated as £100 per chip. Quickchip was subsequently ported to the Acorn Cambridge Workstation, with a low-end version for the BBC Micro, and to the Acorn Archimedes. | https://en.wikipedia.org/wiki?curid=592816 | 1,236,512 |
1,678,861 | Designed specifically as a large-scale thermal-vacuum test chamber for qualification testing of vehicles and equipment in outer-space conditions, it was discovered in the late 2000s that the unique construction of the SPF interior aluminum vacuum chamber also makes it an extremely large and electrically complex RF cavity with excellent reverberant RF characteristics. In 2009 these characteristics were measured by NIST and others after which the facility was understood to be, not only the world's largest Vacuum chamber, but also the world's largest EMI/EMC test facility. In 2011 NASA GRC successfully performed a calibration of the aluminum vacuum chamber using IEC 61000-4-21 methodologies. As a result of these activities, the SPF is capable of performing radiated susceptibility EMI tests for vehicles and equipment per MIL-STD-461 and able to achieve MIL-STD-461F limits above approximately 80 MHz. In the spring of 2017 the low-power characterizations and calibrations from 2009 and 2011 were proven correct in a series of high-power tests performed in the chamber to validate its capabilities. The SPF chamber is currently being prepared for EMI radiated susceptibility testing of the crew module for the Artemis 1 of NASA's Orion spacecraft. | https://en.wikipedia.org/wiki?curid=6904158 | 1,677,918 |
431,882 | In 1968, the US Navy took a hard look at its air-to-air problems over North Vietnam and tasked Captain Frank Ault to come up with recommendations to improve the situation. His report became known as the Ault Report. It resulted in the establishment of TOPGUN and incorporation of DACT into the syllabus. The United States Navy Fighter Weapons School adopted the nimble subsonic A-4 Skyhawk to simulate subsonic Soviet fighters, while the F-5E Tiger simulated the supersonic MiG-21 fighter. Both the Skyhawk and Tiger were used in the 1986 film "Top Gun". After aerial combat resumed again in 1972 over North Vietnam the Navy had numerous TOPGUN graduates who were ready to take on the VPAF MiG-17, MiG-19 and MiG-21 pilots that had also been training and were prepared for the resumption of hostilities. The Navy's win/loss exchange ratio soared to over 20:1 before the loss of a Marine Phantom brought it back to 12.5:1 by 1973; an unqualified testament to the value of the TOPGUN approach and DACT. The USAF did not improve its exchange ratio at all in the same period and hurriedly began to adopt DACT, even to the point of inviting Navy Crusaders to visit a base in Thailand in 1972 to conduct DACT with the F-4 Phantoms based there. | https://en.wikipedia.org/wiki?curid=5921677 | 431,670 |
422,685 | Carl Paul Gottfried von Linde (11 June 1842 – 16 November 1934) was a German scientist, engineer, and businessman. He discovered a refrigeration cycle and invented the first industrial-scale air separation and gas liquefaction processes, which led to the first reliable and efficient compressed-ammonia refrigerator in 1876. These breakthroughs laid the backbone for the 1913 Nobel Prize in Physics that was awarded to Heike Kamerlingh Onnes. Linde was a member of scientific and engineering associations, including being on the board of trustees of the Physikalisch-Technische Reichsanstalt and the Bavarian Academy of Sciences and Humanities. Linde was also the founder of what is now known as Linde plc but formerly known (variously) as the Linde division of Union Carbide, Linde, Linde Air Products, Praxair, and others. Linde is the world's largest producer of industrial gases and ushered in the creation of the global supply chain for industrial gases. He was knighted in 1897 as Ritter von Linde. | https://en.wikipedia.org/wiki?curid=993397 | 422,479 |
589,028 | The panel recommended in results released on September 12, 2008, that ASCE should immediately take steps to remove the potential for conflict of interest in its participation in post-disaster engineering studies. The most important recommendations were that peer review funds over $1 million should come from a separate source, like the National Institute of Standards and Technology (NIST), that ASCE should facilitate but not control the assessment teams, and that information to the public and press should be disseminated not under the extremely tight controls that Ray Seed and his team experienced. It concluded that ASCE should draw up an ethics policy to eliminate questions of possible conflicts of interest. | https://en.wikipedia.org/wiki?curid=599261 | 588,726 |
2,136,277 | The history of the property shows the progressive development of the site from the medieval city wall, moving on to the choice of the site by the Infantado and Villafranca families and the subsequent evolution of the urban development through to the 19th century. The Palace, built between 1717 and 1734 under the supervision of the architect Francisco Ruiz, coincided with the gradual establishment in Madrid of the Alvarez de Toledo family, which reached its maximum splendour through the union with the Medina Sidionia and Alba families as a result of the wedding between the 11th Marquis José Álvarez de Toledo y Dubois and María Cayetana de Silva, 13th Duchess of Alba. After this period, the 19th century was witness to the rise of a new noble class based on agricultural and industrial success, and particularly that of Pérez-Seoana y Roca de Togores family, the Barons of Riudoms, appointed Duke of Pinohermoso in 1790 and Grandee of Spain in 1794 by Charles IV of Spain. This family acquired the palace in 1872 and was responsible for organizing the décor lasting through to our day, in which an important role was played by the architect , and which the current restoration process has returned to its original splendor. | https://en.wikipedia.org/wiki?curid=38744545 | 2,135,049 |
951,657 | The International Federation of Robotics has predicted a worldwide increase in adoption of industrial robots and they estimated 1.7 million new robot installations in factories worldwide by 2020 [IFR 2017]. Rapid advances in automation technologies (e.g. fixed robots, collaborative and mobile robots, and exoskeletons) have the potential to improve work conditions but also to introduce workplace hazards in manufacturing workplaces. Despite the lack of occupational surveillance data on injuries associated specifically with robots, researchers from the US National Institute for Occupational Safety and Health (NIOSH) identified 61 robot-related deaths between 1992 and 2015 using keyword searches of the Bureau of Labor Statistics (BLS) Census of Fatal Occupational Injuries research database (see info from Center for Occupational Robotics Research). Using data from the Bureau of Labor Statistics, NIOSH and its state partners have investigated 4 robot-related fatalities under the Fatality Assessment and Control Evaluation Program. In addition the Occupational Safety and Health Administration (OSHA) has investigated dozens of robot-related deaths and injuries, which can be reviewed at OSHA Accident Search page. Injuries and fatalities could increase over time because of the increasing number of collaborative and co-existing robots, powered exoskeletons, and autonomous vehicles into the work environment. | https://en.wikipedia.org/wiki?curid=147918 | 951,152 |
1,537,604 | During the twentieth century, a myriad of theories were developed for the origin of primate sensory adaptations. Evolutionary "progress" was marked by the adaptive characteristics of visual and tactile structures, yet a reduction in olfactory abilities. This theory was further elaborated by Le Gros Clark, asserting the reduction of olfactory structures was attributed to the diminished need for smell in arboreal environments. This theory was later challenged with the existence of arboreal mammals that do not exhibit primate traits that are considered "adaptive" (specifically, reduced olfaction), yet they are still successful within their respective environment. Furthermore, strepsirrhine primates demonstrate the social behavior of scent-marking in both terrestrial and arboreal habitats. Arboreal New World primates (Platyrrhini) possess skin scent-glands and also exhibit the same scent-marking traits as do strepsirrhines. Studies have provided a structural explanation for the reduced olfaction in primates, proposing that degeneration of the nasal region resulted from crowding of the nasal cavity in conjunction with progressively convergent orbits. | https://en.wikipedia.org/wiki?curid=46405867 | 1,536,732 |
875,002 | After five years of collaboration, Collier arranged for Piper to work with pharmacologist John Vane at the Royal College of Surgeons of England, in order to learn Vane's new bioassay methods, which seemed like a possible solution to the "in vitro" testing failures. Vane and Piper tested the biochemical cascade associated with anaphylactic shock (in extracts from guinea pig lungs, applied to tissue from rabbit aortas). They found that aspirin inhibited the release of an unidentified chemical generated by guinea pig lungs, a chemical that caused rabbit tissue to contract. By 1971, Vane identified the chemical (which they called "rabbit-aorta contracting substance," or RCS) as a prostaglandin. In a 23 June 1971 paper in the journal "Nature", Vane and Piper suggested that aspirin and similar drugs (the nonsteroidal anti-inflammatory drugs or NSAIDs) worked by blocking the production of prostaglandins. Later research showed that NSAIDs such as aspirin worked by inhibiting cyclooxygenase, the enzyme responsible for converting arachidonic acid into a prostaglandin. | https://en.wikipedia.org/wiki?curid=16283254 | 874,540 |
771,673 | Wireless telegraphy or radiotelegraphy, commonly called CW (continuous wave), ICW (interrupted continuous wave) transmission, or on-off keying, and designated by the International Telecommunication Union as emission type A1A or A2A, is a radio communication method. It was transmitted by several different modulation methods during its history. The primitive spark-gap transmitters used until 1920 transmitted damped waves, which had very wide bandwidth and tended to interfere with other transmissions. This type of emission was banned by 1934, except for some legacy use on ships. The vacuum tube (valve) transmitters which came into use after 1920 transmitted code by pulses of unmodulated sinusoidal carrier wave called continuous wave (CW), which is still used today. To receive CW transmissions, the receiver requires a circuit called a beat frequency oscillator (BFO). The third type of modulation, frequency-shift keying (FSK) was used mainly by radioteletype networks (RTTY). Morse code radiotelegraphy was gradually replaced by radioteletype in most high volume applications by World War II. | https://en.wikipedia.org/wiki?curid=33131 | 771,259 |
870,513 | Two years on from the introduction of CD-ROM products, adoption of the technology was still at a "tentative state", with £8 million having been spent on equipment and an estimated 3,000 drives deployed in UK schools. Drive prices had fallen significantly, from around £1,000 to £300 and with a further decline to £200 anticipated. As a significant technology in the delivery of multimedia content, the focus had shifted from merely using CD-ROM as a cheap storage medium for large amounts of graphics and text to aspirations of providing "high-quality, full-screen graphics coupled with hi-fi stereo sound" on CD media, with the principal challenge identified as being able to deliver compressed video that either a computer or a drive could decompress without compromising video quality or introducing incompatibilities between different manufacturers' products. | https://en.wikipedia.org/wiki?curid=63145 | 870,053 |
1,600,554 | One of the works of Alexey Kondrashov is called the Kondrashov Hypothesis or the deterministic mutation hypothesis. This hypothesis explains the benefits of sexual reproduction. Kondrashov argues that because of the slightly deleterious effect of mutations the population will tend to be composed of individuals with a small number of mutations. Because of the recombination effect of the sex on the genotypes the individuals with fewer and more deleterious mutations will be created. Since there is a major selective disadvantage to individuals with more mutations, these individuals die out. Alexey Kondrashov also worked in the field of protein evolution. Kondrashov states that amino acid composition of proteins varies between taxa, so it can evolve. For example, the organism that has more G+C base pairs in the genome will have more amino acids encoded by G+C rich codons. To support this hypothesis Kondrahov et al. compared sets of orthologous proteins from 15 taxa, which represent three domains of life. As a result, Ser, His, Met, Phe and Cysaccure in 14 taxa. Gly, Glu, Ala, Pro was pretty much lost. The amino acids with reducing frequencies was probably among the first incorporated into the genetic codes. Also, all amino acids except Ser, which have an increase in frequency, were probably recruited late. This process also continues to go today. | https://en.wikipedia.org/wiki?curid=9334988 | 1,599,653 |
115,376 | Light travels from the fixation object to the fovea through an imaginary path called the visual axis. The eye's tissues and structures that are in the visual axis (and also the tissues adjacent to it) affect the quality of the image. These structures are: tear film, cornea, anterior chamber, pupil, lens, vitreous, and finally the retina. The posterior part of the retina, called the retinal pigment epithelium (RPE) is responsible for, among many other things, absorbing light that crosses the retina so it cannot bounce to other parts of the retina. In many vertebrates, such as cats, where high visual acuity is not a priority, there is a reflecting tapetum layer that gives the photoreceptors a "second chance" to absorb the light, thus improving the ability to see in the dark. This is what causes an animal's eyes to seemingly glow in the dark when a light is shone on them. The RPE also has a vital function of recycling the chemicals used by the rods and cones in photon detection. If the RPE is damaged and does not clean up this "shed" blindness can result. | https://en.wikipedia.org/wiki?curid=648954 | 115,331 |
2,055,700 | GIS is also being used to model some of Masdar's key infrastructural features directly. Its involvement in simulating the citywide Personal Rapid Transport System (PRTS) is one such example. As common road vehicles are banned from the city, the "driverless" transit system will transport people and freight across the 7km2 area. GIS is capable of modelling the system route, due to comprise 85 passenger stations and approximately 1,700 automated vehicles. By drawing spatial buffer zones around potential PRTS stops, passenger-distance maps can visualize residential areas that fall outside of ideal service requirements. GIS is an instrumental tool in visualizing such problems. A smooth, functioning PRTS is a central infrastructural aspect of Masdar's grand vision, and engineering companies who specialize in GIS technologies have helped in realizing this digitally-orchestrated dream. Yet journalists in particular have been sceptical. As Bryan Walsh has argued; "will Masdar City ever really develop the authenticity of a real city?" Or as Jonathan Glancey contends, will its "ultra-modern aspects ... prove to be a mirage"? | https://en.wikipedia.org/wiki?curid=31783151 | 2,054,517 |
230,365 | Data mining pharmacovigilance databases is one approach that has become increasingly popular with the availability of extensive data sources and inexpensive computing resources. The data sources (databases) may be owned by a pharmaceutical company, a drug regulatory authority, or a large healthcare provider. Individual case safety reports in these safety databases are retrieved and converted into structured format, and statistical methods (usually as mathematical algorithm) are applied to calculate statistical measures of association. If the statistical measure crosses an arbitrarily set threshold, a signal is declared for a given drug associated with a given adverse event. All signals deemed worthy of investigation, require further analysis using all available data in an attempt to confirm or refute the signal. If the analysis is inconclusive, additional data may be needed such as a post-marketing observational trial. | https://en.wikipedia.org/wiki?curid=1243554 | 230,247 |
688,245 | As laser science needed good theoretical foundations, and also because research into these soon proved very fruitful, interest in quantum optics rose. Following the work of Dirac in quantum field theory, John R. Klauder, George Sudarshan, Roy J. Glauber, and Leonard Mandel applied quantum theory to the electromagnetic field in the 1950s and 1960s to gain a more detailed understanding of photodetection and the statistics of light (see degree of coherence). This led to the introduction of the coherent state as a concept which addressed variations between laser light, thermal light, exotic squeezed states, etc. as it became understood that light cannot be fully described just referring to the electromagnetic fields describing the waves in the classical picture. In 1977, Kimble et al. demonstrated a single atom emitting one photon at a time, further compelling evidence that light consists of photons. Previously unknown quantum states of light with characteristics unlike classical states, such as squeezed light were subsequently discovered. | https://en.wikipedia.org/wiki?curid=658955 | 687,887 |
309,880 | On Earth, several complex multicellular life forms (or eukaryotes) have been identified with the potential to survive conditions that might exist outside the conservative habitable zone. Geothermal energy sustains ancient circumvental ecosystems, supporting large complex life forms such as "Riftia pachyptila". Similar environments may be found in oceans pressurised beneath solid crusts, such as those of Europa and Enceladus, outside of the habitable zone. Numerous microorganisms have been tested in simulated conditions and in low Earth orbit, including eukaryotes. An animal example is the "Milnesium tardigradum", which can withstand extreme temperatures well above the boiling point of water and the cold vacuum of outer space. In addition, the lichens "Rhizocarpon geographicum" and "Xanthoria elegans" have been found to survive in an environment where the atmospheric pressure is far too low for surface liquid water and where the radiant energy is also much lower than that which most plants require to photosynthesize. The fungi "Cryomyces antarcticus" and "Cryomyces minteri" are also able to survive and reproduce in Mars-like conditions. | https://en.wikipedia.org/wiki?curid=1072751 | 309,713 |
1,232,354 | In order to test real world performance of UHTC materials in reentry environments, NASA Ames conducted two flight experiments in 1997 and 2000. The slender Hypersonic Aero-thermodynamic Research Probes (SHARP B1 and B2) briefly exposed the UHTC materials to actual reentry environments by mounting them on modified nuclear ordnance Mk12A reentry vehicles and launching them on Minuteman III ICBMs. Sharp B-1 had a HfB2/SiC nosecone with a tip radius of 3.5 mm which experienced temperatures well above 2,815 °C during reentry, ablating away at an airspeed of 6.9 km/s as predicted; however, it was not recovered and its axially-symmetric cone shape did not provide flexural strength data needed to evaluate the performance of UHTCs in linear leading edges. To improve the characterization of UHTC mechanical strength and better study their performance, SHARP-B2, was recovered and included four retractable, sharp wedge-like protrusions called "strakes" which each contained three different UHTC compositions which were extended into the reentry flow at different altitudes. | https://en.wikipedia.org/wiki?curid=38050893 | 1,231,692 |
1,396,627 | Economic historian Bernice Hamilton describes the 1700s as having "completely transformed" all "the medical professions," explaining that "advances in medical education and science," the emergence of a robust middle class, "as well as the growth of 'a professional feeling'" had greatly changed the socio-economic order by the end of the 18th century. Thanks to the ruling in the Rose Case back in London, apothecaries began 1705 as fully accredited medical professionals who could write prescriptions. Hamilton notes "…the apothecaries, once mere tradesmen and the 'servants of the physician,' had become practicing doctors," treating patients directly. These trends spread to the colonies, and though apothecaries never organized into a legally distinct and guilded profession in North America, the rural hinterlands mirrored the prevalence of the apothecary in Britain, where "in more remote locales, the apothecary 'was usually the only doctor.'" | https://en.wikipedia.org/wiki?curid=34631752 | 1,395,856 |
998,350 | Yang reported in 2016 that an interaction with the Earth's magnetic field had caused the fairly large apparent thrust in their 2012 paper. Tajmar looked for potential Lorentz force interactions between power leads in trying to replicate White's experimental setup. Another source of error could have arisen from electromagnetic interaction with the walls of the vacuum chamber. White argued that any wall interaction could only be the result of a well-formed resonance coupling between the device and wall and that the high frequency used imply the chances of this would be highly dependent on the device's geometry. As components get warmer due to thermal expansion, the device's geometry changes, shifting the resonance of the cavity. In order to counter this effect and keep the system in optimal resonance conditions, White used a phase-locked loop system (PLL). Their analysis assumed that using a PLL ruled out significant electromagnetic interaction with the wall. | https://en.wikipedia.org/wiki?curid=6883009 | 997,832 |
550,442 | It was assumed that fishes to a large degree evolved around reefs, but since their origin about 480 million years ago, they lived in near-shore environments like intertidal areas or permanently shallow lagoons and didn't start to proliferate into other biotopes before 60 million years later. A few adapted to deeper water, while solid and heavily built forms stayed where they were or migrated into freshwater. The increase of primary productivity on land during the late Devonian changed the freshwater ecosystems. When nutrients from plants were released into lakes and rivers, they were absorbed by microorganisms which in turn was eaten by invertebrates, which served as food for vertebrates. Some fish also became detritivores. Early tetrapods evolved a tolerance to environments which varied in salinity, such as estuaries or deltas. | https://en.wikipedia.org/wiki?curid=38046595 | 550,154 |
1,004,655 | Tim Noakes, based on an earlier idea by the 1922 Nobel Prize in Physiology or Medicine winner Archibald Hill has proposed the existence of a central governor. In this, the brain continuously adjusts the power output by muscles during exercise in regard to a safe level of exertion. These neural calculations factor in prior length of strenuous exercise, the planned duration of further exertion, and the present metabolic state of the body. This adjusts the number of activated skeletal muscle motor units, and is subjectively experienced as fatigue and exhaustion. The idea of a central governor rejects the earlier idea that fatigue is only caused by mechanical failure of the exercising muscles ("peripheral fatigue"). Instead, the brain models the metabolic limits of the body to ensure that whole body homeostasis is protected, in particular that the heart is guarded from hypoxia, and an emergency reserve is always maintained. The idea of the central governor has been questioned since ‘physiological catastrophes’ can and do occur suggesting that if it did exist, athletes (such as Dorando Pietri, Jim Peters and Gabriela Andersen-Schiess) can override it. | https://en.wikipedia.org/wiki?curid=395477 | 1,004,137 |
1,348,062 | A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and in the past billion years; basking sharks and copepods are just two examples of giant and microscopic organisms that feed upon plankton. Planktivory can be an important mechanism of top-down control that contributes to trophic cascades in aquatic and marine systems. There is a tremendous diversity of feeding strategies and behaviors that planktivores utilize to capture prey. Some planktivores utilize tides and currents to migrate between estuaries and coastal waters; other aquatic planktivores reside in lakes or reservoirs where diverse assemblages of plankton are present, or migrate vertically in the water column searching for prey. Planktivore populations can impact the abundance and community composition of planktonic species through their predation pressure, and planktivore migrations facilitate nutrient transport between benthic and pelagic habitats. | https://en.wikipedia.org/wiki?curid=36726184 | 1,347,321 |
788,921 | Eileen Marie Collins was born in Elmira, New York, on 19 November 1956. Her parents were James Edward Collins and his wife Rose Marie O'Hara. Her ancestors came to America in the mid-1800s, settling in Pennsylvania and Elmira, New York. She has three siblings: an older brother, Edward; a younger sister, Margaret; and a younger brother, James. Her father served in the US Navy in the Pacific Theater during World War II. After the war he managed the family bar, then became a surveyor. Her parents separated when she was young, and her mother took a job as a stenographer at the Elmira Correctional Facility. As a child, she was shy and needed speech therapy for her stutter. She participated in Girl Scouts, and attended the El-Ne-Ho summer camp. She expressed an interest in becoming a pilot, reading books such as "Fate Is the Hunter" and "God Is My Co-Pilot", and subscribing to "Air Force Magazine". | https://en.wikipedia.org/wiki?curid=336966 | 788,497 |
1,933,176 | Given that PP cells reside in the pancreas and serve both the digestive and endocrine systems, the roles it can play within a clinical setting are vast and important to analyze. Many of the applications geared around pancreatic polypeptide cells and the substances they secrete serve to better understand and treat diabetes better than it already is, and they have been heavily studied in rats. Studies are also being pursued to see how PP cells and the substances they release can help individuals who do not have a pancreas anymore due to various circumstances regulate insulin levels and maintain homeostasis. Other studies relating to PP cells have shown that these cells help to play a role in hunger for organisms. Another area of clinical research surrounding the pancreatic islets and PP cells is in regards to cellular communication. Currently, therapeutic strategies are being studied to help improve the communication between different cells in this pancreatic region by diving deeper into the cellular functions of these very cells and the regions they islet regions they reside in. The current studies being done mainly focus on diabetes and preventing the adverse effects it poses on mammalian organisms. The studies being done now focus heavily on the potential for stem-cell therapeutics or the development of different pharmaceuticals to help limit this condition. | https://en.wikipedia.org/wiki?curid=602549 | 1,932,068 |
454,271 | Following projects to the Human Genome Project seek to address a deeper and more diverse characerization of the human genetic variability, which the reference genome is not able to represent. The HapMap Project, active during the period 2002 -2010, with the purpose of creating a haplotypes map and their most common variations among different human populations. Up to 11 populations of different ancestry were studied, such as individuals of the Han ethnic group from China, Gujaratis from India, the Yoruba people from Nigeria or Japanese people, among others. The 1000 Genomes Project, carried out between 2008 and 2015, with the aim of creating a database that includes more than 95% of the variations present in the human genome and whose results can be used in studies of association with diseases (GWAS) such as diabetes, cardiovascular or autoimmune diseases. A total of 26 ethnic groups were studied in this project, expanding the scope of the HapMap project to new ethnic groups such as the Mende people of Sierra Leone, the Vietnamese people or the Bengali people. The Human Pangenome Project, which started its initial phase in 2019 with the creation of the Human Pangenome Reference Consortium, seeks to create the largest map of human genetic variability taking the results of previous studies as a starting point. | https://en.wikipedia.org/wiki?curid=27708701 | 454,050 |
144,836 | Cordite was used initially in the .303 British, Mark I and II, standard rifle cartridge between 1891 and 1915; shortages of cordite in World War I led to the creation of the 'Devils Porridge' munitions factory on the English-Scottish border, (producing 800 tonnes of cordite per annum). The UK also imported some United States–developed smokeless powders for use in rifle cartridges. Cordite was also used for large weapons, such as tank guns, artillery, and naval guns. It has been used mainly for this purpose since the late 19th century by the UK and British Commonwealth countries. Its use was further developed before World War II, and as Unrotated Projectiles for launching anti-aircraft weapons. Small cordite rocket charges were also developed for ejector seats made by the Martin-Baker Company. Cordite was also used in the detonation system of the Little Boy atomic bomb dropped over Hiroshima in August 1945. | https://en.wikipedia.org/wiki?curid=58244 | 144,778 |
1,329,650 | Previous research has shown REM sleep to reactivate cortical neural assemblies post-training on a serial reaction time task (SRT), in other words REM sleep replays the processing that occurred while one learnt an implicit task in the previous waking hours. However, control subjects did not complete a SRT task, thus researchers could not assume the reactivation of certain networks to be a result of the implicitly learned sequence/grammar as it could simply be due to elementary visuomotor processing which was obtained in both groups. To answer this question the experiment was redone and another group was added who also took part in the SRT task. They experienced no sequence to the SRT task (random group), whereas the experimental group did experience a sequence (probabilistic group), although without conscious awareness. Results of PET scans indicate that bilateral cuneus were significantly more activated during SRT practice as well as post-training REM sleep in the Probabilistic group than the Random group. In addition, this activation was significantly increased during REM sleep versus the SRT task. This suggests that specific brain regions are specifically engaged in the post-processing of sequential information. This is further supported by the fact that regional CBF (rCBF) during post-training REM sleep are modulated by the level of high-order, but not low-order learning obtained prior to sleep. Therefore, brain regions that take part in a learning process are modulated by both the sequential structure of the learned material (increased activation in cuneus), and the amount of high-order learning (rCBF). | https://en.wikipedia.org/wiki?curid=26685741 | 1,328,921 |
720,593 | "The New York Times" wrote that "in a community known for its biting, sometimes misogynistic discourse on Twitter, Mr. Kaminsky stood out for his empathy." He was known for regularly paying for hotels or travel bills for other people going to Black Hat, and once paid for a plane ticket for a friend of his after she had broken up with her boyfriend; the pair later married. At various points in his career, Kaminsky shifted his focus to work on projects related to his friends' and family's health, developing an app that helps colorblind people, working on hearing aid technology, and developing telemedicine tools related to AIDS among refugees for Academic Model Providing Access to Healthcare (AMPATH). According to his mother, "he did things because they were the right thing to do, not because they would elicit financial gain." | https://en.wikipedia.org/wiki?curid=17498141 | 720,213 |
970,218 | Q-mediated turn-on of late transcription begins about 6–8 min after infection if the lytic pathway is chosen. More than 25 genes are expressed from the single late promoter, resulting in four parallel biosynthetic pathways. Three of the pathways are for production of the three components of the virion: the DNA-filled head, the tail, and the side tail fibers. The virions self-assemble from these components, with the first virion appearing at about 20 min after infection. The fourth pathway is for lysis. In lambda 5 proteins are involved in lysis: the holin and antiholin from gene "S", the endolysin from gene "R" and the spanin proteins from genes "Rz" and "Rz1". In wild-type lambda, lysis occurs at about 50 min, releasing approximately 100 completed virions. The timing of lysis is determined by the holin and antiholin proteins, with the latter inhibiting the former. In overview, the holin protein accumulates in the cytoplasmic membrane until suddenly forming micron-scale holes, which triggers lysis. The endolysin R is released to the periplasm, where it attacks the peptidoglycan. The spanin proteins Rz and Rz1 accumulate in the cytoplasmic and outer membranes, respectively, and form a complex spanning the periplasm through the meshwork of the peptidoglycan. When the endolysin degrades the peptidoglycan, the spanin complexes are liberated and cause disruption of the outer membrane. Destruction of the peptidoglycan by the endolysin and disruption of the outer membrane by the spanin complex are both required for lysis in lambda infections. | https://en.wikipedia.org/wiki?curid=765350 | 969,708 |
1,902,102 | In the second part (Scheme 2) the procedures are still confined to rings A and B. More protective groups were added to triol 15 as reaction with PPTS and 2-methoxypropene gives the acetonide 16. At this point the double bond in ring A was epoxidized with "m"-CPBA and sodium carbonate to epoxide 17 and a Grob fragmentation (also present in the Holton effort) initiated by DABCO opened up the AB ring system in alcohol 18, which was not isolated but protected as a TIPS silyl ether 19 with triisopropylsilyl triflate and 2,6-lutidine. The C1 position was next oxidized by the phosphite ester, P(OEt) and the strong base KO"t"-Bu, and oxygen to alcohol 20 (the stereochemistry controlled by bowl-shaped AB ring with hydroxylation from unhindered convex direction), the primary alcohol group was deprotected with ammonium chloride in methanol to diol 21 and two reductions first with NaBH to triol 22 and then hydrogen gas and Crabtree's catalyst give triol 23. These positions were protected by trimethylsilyl chloride and pyridine to 24 and then triphosgene to 25 in order to facilitate the oxidation of the primary alcohol group to the aldehyde 26 by PCC. | https://en.wikipedia.org/wiki?curid=8705174 | 1,901,012 |
1,422,315 | Due to macromolecular crowding, enzyme assays and biophysical measurements performed in dilute solution may fail to reflect the actual process and its kinetics taking place in the cytosol. One approach to produce more accurate measurements would be to use highly concentrated extracts of cells, to try to maintain the cell contents in a more natural state. However, such extracts contain many kinds of biologically active molecules, which can interfere with the phenomena being studied. Consequently, crowding effects are mimicked "in vitro" by adding high concentrations of relatively inert molecules such as polyethylene glycol, ficoll, dextran, or serum albumin to experimental media. However, using such artificial crowding agents can be complicated, as these crowding molecules can sometimes interact in other ways with the process being examined, such as by binding weakly to one of the components. | https://en.wikipedia.org/wiki?curid=19248693 | 1,421,514 |
349,332 | At the end of the 19th century, the first skyscrapers began to appear in the United States. They were a response to the shortage of land and high cost of real estate in the center of the fast-growing American cities, and the availability of new technologies, including fireproof steel frames and improvements in the safety elevator invented by Elisha Otis in 1852. The first steel-framed "skyscraper", The Home Insurance Building in Chicago, was ten stories high. It was designed by William Le Baron Jenney in 1883, and was briefly the tallest building in the world. Louis Sullivan built another monumental new structure, the Carson, Pirie, Scott and Company Building, in the heart of Chicago in 1904–06. While these buildings were revolutionary in their steel frames and height, their decoration was borrowed from Neo-Renaissance, Neo-Gothic and Beaux-Arts architecture. The Woolworth Building, designed by Cass Gilbert, was completed in 1912, and was the tallest building in the world until the completion of the Chrysler Building in 1929. The structure was purely modern, but its exterior was decorated with Neo-Gothic ornament, complete with decorative buttresses, arches and spires, which caused it to be nicknamed the "Cathedral of Commerce". | https://en.wikipedia.org/wiki?curid=315927 | 349,150 |
1,813,010 | Nine tetrapod trackways from three sites have been reported from the Valentia Slate Formation of Valentia Island, Ireland. The Valentia Slate Formation is composed mostly of purple coloured fine-grained sandstones and siltstones interpreted to represent a fluvial setting. The trackways are late Middle Devonian in age based on a palynological assemblage from the Valentia Slate Formation and the U-Pb radioisotopic dating of an interstratified air-fall tuff bed to ca. 385 Ma, making these tetrapod trackways some of the earliest recorded, along with traces of early Middle Devonian (Eifelian) age from Poland. The most extensive of the Valentia Island trackways is preserved in a fine-grained sandstone and records some 145 imprints in a parallel orientation of the left and right impressions. The systematic variation in size of the impressions affords distinction between tracks left by the manus and pes of the animal, but the trackway does not preserve any finer details. Other trackways at the same site preserve tail and body drag impressions; the nature of the impressions and that of the sandstone led to the interpretation that the setting was not saturated in water. Consequently, these tracks are interpreted as evidence of fully terrestrial locomotion. | https://en.wikipedia.org/wiki?curid=57225997 | 1,811,976 |
2,065,721 | An internationally recognized leader in optometric research and education, Dr. Karla Zadnik became The Ohio State University College of Optometry's dean in June 2014. She received her OD and PhD degrees from the University of California Berkeley School of Optometry and is a Fellow of the American Academy of Optometry. Professional highlights include: American Academy of Optometry President (2011–12): American Optometric Foundation Glenn A. Fry Award Recipient (1995); National Advisory Eye Council of the National Eye Institute (NEI)/National Institutes of Health (2000–04); Study Chair for the NEI-funded Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study; and chair of the first-ever NEI-funded multicenter study based in optometry, the Collaborative Longitudinal Evaluation of Keratoconus (CLEK) Study (1994-2007). At the Ohio State University, she has chaired the Biomedical Sciences Institutional Review Board (IRB) for more than 15 years, and received The Ohio State University's Distinguished Scholar Award in 2010. | https://en.wikipedia.org/wiki?curid=40649289 | 2,064,530 |
1,831,181 | In 1950 Air Staff/PW created special operations wings devoted to the PSYWAR mission to support United States objectives in the Cold War. All Air Commando-designated units had been inactivated after World War II, however the Korean War underscored the need for a substantial Air Force unconventional warfare capability. Despite the urgency of the war, it took eight months before the Air Resupply and Communications Service (ARCS) was activated by HQ USAF at Andrews AFB, Maryland on 23 February 1951. Assigned to Military Air Transport Service (MATS) the plan called for three flying wings, equipped with a mixture of B-29 Superfortress bombers, twin-engine SA-16 amphibians, C-119 and C-54 transports and H-19 helicopters to be established to perform the psychological warfare and unconventional warfare missions. Although MATS was the official parent command of ARCS, operations were directed from the Pentagon Psychological Warfare Division, Directorate of Plans, HQ, USAF. | https://en.wikipedia.org/wiki?curid=18495171 | 1,830,134 |
840,620 | General Benjamin F. Butler bought 12 and Admiral David Dixon Porter bought one, it was not until 1866 that the US Government officially purchased Gatling guns. In 1870, he sold his patents for the Gatling gun to Colt. Gatling remained president of the Gatling Gun Company until it was fully absorbed by Colt in 1897. In 1893, Gatling patented a Gatling gun that replaced the hand cranked mechanism with an electric motor, a relatively new invention at the time, achieving a rate of fire of 3,000 rounds per minute. The hand-cranked Gatling gun was declared obsolete by the United States Army in 1911. Decades later, the mechanical concept was resurrected and wedded to electrically-driven cranking in the M61 Vulcan. That cannon has given rise to numerous variations scaled up to as high as 37 mm and down to 5.56 mm calibers offering versions that are gas-operated as well. | https://en.wikipedia.org/wiki?curid=182949 | 840,170 |
2,028,350 | This gene belongs to the homeobox family, members of which encode a highly conserved family of transcription factors that play an important role in morphogenesis in all multicellular organisms. Mammals possess four similar homeobox gene clusters, HOXA, HOXB, HOXC and HOXD, which are located on different chromosomes and consist of 9 to 11 genes arranged in tandem. This gene, HOXC6, is one of several HOXC genes located in a cluster on chromosome 12. Three genes, HOXC5, HOXC4 and HOXC6, share a 5' non-coding exon. Transcripts may include the shared exon spliced to the gene-specific exons, or they may include only the gene-specific exons. Alternatively spliced transcript variants encoding different isoforms have been identified for HOXC6. Transcript variant two includes the shared exon, and transcript variant one includes only gene-specific exons. HOXC6 plays a role in lymphoma. The HOXC6 isoform, HOXC6-2 is an active carcinogenic for gastric cancer. It stimulates gastric cancer cells proliferation by acting as an oncogene. Downregulation of this gene’s isoforms could potentially lead to less proliferation of certain cancerous cells. With the HOXC6-1 isoform, there were no statistically significant effects on migration, invasion, apoptosis, or proliferation when it was downregulated. According to a study in Cancer Cell International, suppression of the HOXC6 gene plays a role in blocking the TGF-β/SMAD cascade. This then leads to the weakening of epithelial to mesenchymal transition for the cervical carcinoma. | https://en.wikipedia.org/wiki?curid=14813801 | 2,027,183 |
1,134,760 | Off the success of TIROS-1 and ATS-3, NASA in conjunction with United States Geological Survey (USGS), progressed forward in Earth observation through a series of Landsat Satellites launched throughout the 1970s and 1980s. The Nimbus-5 satellite launched in 1972 used passive microwave imaging; a highly successful method to observe changes in sea ice cover. Observation was furthered by succeeding missions such as Nimbus-7, fitted with a Coastal zone colour scanner (CZCS) for detailing colour changes in the Earth's Oceans, and a Total Ozone Mapping Spectrometer (TOMS) to measure solar irradiance and the reflected radiance from the Earth's Atmosphere. The early satellites of these programs have paved the way for much of the EOS program today. The TIROS satellites were extremely important in the testing and development of not only the Earth observing instruments such as spectrometers, but much was also learnt from the various sensors used in order to maintain these satellites in orbit for sustainable periods of time. Sensors such as horizons sensors were tested on these early satellites and have been adapted to produce more advanced methods of observation and operating configurations. | https://en.wikipedia.org/wiki?curid=471278 | 1,134,167 |
783,399 | In 1859, when Charles Darwin's "On the Origin of Species" was first published, the fossil record was poorly known. Darwin described the perceived lack of transitional fossils as "the most obvious and gravest objection which can be urged against my theory," but he explained it by relating it to the extreme imperfection of the geological record. He noted the limited collections available at the time but described the available information as showing patterns that followed from his theory of descent with modification through natural selection. Indeed, "Archaeopteryx" was discovered just two years later, in 1861, and represents a classic transitional form between earlier, non-avian dinosaurs and birds. Many more transitional fossils have been discovered since then, and there is now abundant evidence of how all classes of vertebrates are related, including many transitional fossils. Specific examples of class-level transitions are: tetrapods and fish, birds and dinosaurs, and mammals and "mammal-like reptiles". | https://en.wikipedia.org/wiki?curid=331755 | 782,980 |
112,245 | Mars requires less energy per unit mass (delta V) to reach from Earth than any planet except Venus. Using a Hohmann transfer orbit, a trip to Mars requires approximately nine months in space. Modified transfer trajectories that cut the travel time down to four to seven months in space are possible with incrementally higher amounts of energy and fuel compared to a Hohmann transfer orbit, and are in standard use for robotic Mars missions. Shortening the travel time below about six months requires higher delta-v and an increasing amount of fuel, and is difficult with chemical rockets. It could be feasible with advanced spacecraft propulsion technologies, some of which have already been tested to varying levels, such as Variable Specific Impulse Magnetoplasma Rocket, and nuclear rockets. In the former case, a trip time of forty days could be attainable, and in the latter, a trip time down to about two weeks. In 2016, a University of California, Santa Barbara scientist said they could further reduce travel time for a small robotic probe to Mars down to "as little as 72 hours" with the use of a laser propelled sail (directed photonic propulsion) system instead of the fuel-based rocket propulsion system. | https://en.wikipedia.org/wiki?curid=1744360 | 112,200 |
58,136 | The first inscribed tablets were purely pictographic, which makes it technically difficult to know in which language they were written. Different languages have been proposed though usually Sumerian is assumed. Later tablets after circa 2,900 BC start to use syllabic elements, which clearly show a language structure typical of the non-Indo-European agglutinative Sumerian language. The first tablets using syllabic elements date to the Early Dynastic I-II, circa 2,800 BC, and they are agreed to be clearly in Sumerian. This is the time when some pictographic element started to be used for their phonetical value, permitting the recording of abstract ideas or personal names. Many pictographs began to lose their original function, and a given sign could have various meanings depending on context. The sign inventory was reduced from some 1,500 signs to some 600 signs, and writing became increasingly phonological. Determinative signs were re-introduced to avoid ambiguity. Cuneiform writing proper thus arises from the more primitive system of pictographs at about that time (Early Bronze Age II). | https://en.wikipedia.org/wiki?curid=350137 | 58,111 |
1,905,219 | Opened in 1828, the ENVT is the oldest "Grande École" in Toulouse, and the school has trained more than a quarter of all veterinarians in France – over 15,000 graduates. As a "Grande École", ENVT a French institution of higher education that is separate from, but parallel and connected to the main framework of the French public university system. Similar to the Ivy League in the United States, Oxbridge in the UK, and C9 League in China, "Grandes Écoles" are elite academic institutions that admit students through an extremely competitive process. "Grandes Écoles" typically they have much smaller class sizes and student bodies than public universities in France, and many of their programs are taught in English. International internships, study abroad opportunities, and close ties with government and the corporate world are a hallmark of the "Grandes Écoles". Degrees from "ENVT" are accredited by the "Conférence des Grandes Écoles" and awarded by the Ministry of National Education (France) (). | https://en.wikipedia.org/wiki?curid=30157147 | 1,904,124 |
1,513,198 | In Israel, a multicenter study at eight fertility units located in hospitals across the country found that unit directors are familiar with the patient-centered care approach and in general support it. Nonetheless, interviews with the unit directors revealed that, despite the importance of involving a mental health professional in the care of fertility patients, only some of the units have a social worker or psychologist on their permanent staff. The study also included a survey of 524 patients. These patients were asked to rate the units where they were treated on a scale of 0-3. Scores ranged from 1.85 to 2.49, with an average of 2.0, compared with the average score of 2.2 given by staff members. The difference was statistically significant. There were also statistically significant differences in the scores across the various dimensions of patient-centered care, according to the patients’ socioeconomic background. In particular, the patients gave their lowest ratings to the emotional support dimension, while the staff members believed that the emotional support they provided stood out as a positive aspect of their work. | https://en.wikipedia.org/wiki?curid=23453324 | 1,512,347 |
562,440 | The TFT array consists of a sheet of glass covered with a thin layer of silicon that is in an amorphous or disordered state. At a microscopic scale, the silicon has been imprinted with millions of transistors arranged in a highly ordered array, like the grid on a sheet of graph paper. Each of these thin-film transistors (TFTs) is attached to a light-absorbing photodiode making up an individual pixel (picture element). Photons striking the photodiode are converted into two carriers of electrical charge, called electron-hole pairs. Since the number of charge carriers produced will vary with the intensity of incoming light photons, an electrical pattern is created that can be swiftly converted to a voltage and then a digital signal, which is interpreted by a computer to produce a digital image. Although silicon has outstanding electronic properties, it is not a particularly good absorber of X-ray photons. For this reason, X-rays first impinge upon scintillators made from such materials as gadolinium oxysulfide or caesium iodide. The scintillator absorbs the X-rays and converts them into visible light photons that then pass onto the photodiode array. | https://en.wikipedia.org/wiki?curid=37585910 | 562,151 |
10,445 | Classic Maya rule was centred in a royal culture that was displayed in all areas of Classic Maya art. The king was the supreme ruler and held a semi-divine status that made him the mediator between the mortal realm and that of the gods. From very early times, kings were specifically identified with the young maize god, whose gift of maize was the basis of Mesoamerican civilization. Maya royal succession was patrilineal, and royal power only passed to queens when doing otherwise would result in the extinction of the dynasty. Typically, power was passed to the eldest son. A young prince was called a "chʼok" ("youth"), although this word later came to refer to nobility in general. The royal heir was called "bʼaah chʼok" ("head youth"). Various points in the young prince's childhood were marked by ritual; the most important was a bloodletting ceremony at age five or six years. Although being of the royal bloodline was of utmost importance, the heir also had to be a successful war leader, as demonstrated by taking of captives. The enthronement of a new king was a highly elaborate ceremony, involving a series of separate acts that included enthronement upon a jaguar-skin cushion, human sacrifice, and receiving the symbols of royal power, such as a headband bearing a jade representation of the so-called "jester god", an elaborate headdress adorned with quetzal feathers, and a sceptre representing the god Kʼawiil. | https://en.wikipedia.org/wiki?curid=18449273 | 10,440 |
2,076,397 | In those years, "pop art" developed in the United States, a style with a marked component of popular inspiration that took images from the world of advertising, photography, comics and the mass media. One of its main exponents was Andy Warhol. He used to work by silkscreen, in series ranging from portraits of famous people such as Elvis Presley, Marilyn Monroe, Jacqueline Kennedy or Mao Tse-tung, through his gruesome "Catastrophes" series, "Electric Chairs" and "Race Riots", to all kinds of objects, such as his series of Campbell's Soup Cans or Coca-Cola, elaborated with a garish, strident colorism and a pure, impersonal technique. Warhol chose his images from the mass media, stereotypical images, which he cut out and framed to send to the silkscreen workshop, where they were enlarged, the format and color chosen and the print run made, on paper or canvas, in unnumbered series. His work is cold, indifferent, uniform and mechanized, suitable for an industrialized society geared towards consumption. Even death is treated in the same distant and cold way, as it is still a common image in the media. Another American exponent was Roy Lichtenstein, who was inspired by comics, with images in vignettes that often show the stippling typical of printed editions. These are trivial, almost vulgar images, but emphasized in such a way as to convey the emotions of the characters, albeit with a cold and mechanical look. | https://en.wikipedia.org/wiki?curid=72166508 | 2,075,198 |
753,605 | The 1938 series was extremely robust and proved very popular with Axis forces as well as Allied troops, who used captured examples. Many German soldiers, including elite forces such as the Waffen-SS and Fallschirmjäger forces, preferred the Beretta 38. Germany manufactured 231,193 Beretta M38s in 1944 and 1945. Firing a more powerful Italian version of the widely distributed 9×19mm Parabellum cartridge, the "Cartuccia 9 mm M38", the Beretta was accurate at longer ranges than most other submachine guns. The MAB could deliver impressive firepower at close range, and at longer distances its size and weight was an advantage, making the weapon stable and easy to control. In expert hands, the Beretta MAB allowed accurate short-burst shooting up to and its effective range with Italian M38 ammunition was s, an impressive result for a 9 mm submachine gun. | https://en.wikipedia.org/wiki?curid=2175269 | 753,203 |
118,719 | On May 22, 1894, the main building (Tillman Hall) was destroyed by a fire, which consumed the library, classrooms, and offices. Tillman Hall was rebuilt in 1894 and is still standing today. The first graduating class of Clemson was in 1896 with degrees in mechanical-electrical engineering and agriculture. Clemson's first football team began in 1896 led by trainer Walter Riggs. Henry Hartzog, a graduate of The Citadel, The Military College of South Carolina, became president of Clemson in 1897. Hartzog created a textile department in 1898. Clemson became the first Southern school to train textile specialists. Hartzog expanded the curriculum with more industrialization skills such as foundry work, agriculture studies, and mechanics. In 1902 a large student walkout over the use of rigid military discipline escalated tensions between students and faculty forcing Hartzog to resign. Patrick Mell succeeded Hartzog from 1902 to 1910. | https://en.wikipedia.org/wiki?curid=147456 | 118,672 |
263,253 | Heating of the EUV mask pellicle (film temperature up to 750 K for 80 W incident power) is a significant concern, due to the resulting deformation and transmission decrease. ASML developed a 70 nm thick polysilicon pellicle membrane, which allows EUV transmission of 82%; however, less than half of the membranes survived expected EUV power levels. SiNx pellicle membranes also failed at 82 W equivalent EUV source power levels. At target 250 W levels, the pellicle is expected to reach 686 degrees Celsius, well over the melting point of aluminum. Alternative materials need to allow sufficient transmission as well as maintain mechanical and thermal stability. However, graphite, graphene or other carbon nanomaterials (nanosheets, nanotubes) are damaged by EUV due to the release of electrons and also too easily etched in the hydrogen cleaning plasma expected to be deployed in EUV scanners. Hydrogen plasmas can also etch silicon as well. A coating helps improve hydrogen resistance, but this reduces transmission and/or emissivity, and may also affect mechanical stability (e.g., bulging). | https://en.wikipedia.org/wiki?curid=2154371 | 263,114 |
426,265 | STS-95 "Discovery" (October 29 to November 7, 1998) was a nine-day mission during which the crew supported a variety of research payloads, including deployment of the Spartan solar-observing spacecraft and the testing of the Hubble Space Telescope Orbital Systems Test Platform. The crew also conducted investigations on the correlation between space flight and the aging process. Parazynski was the flight engineer (MS2) for the mission, as well as the navigator for the Spartan spacecraft rendezvous. During the flight, he also operated the Shuttle's robotic arm in support of the testing of several space-vision systems being considered for ISS assembly. In addition, he was responsible for monitoring several life sciences investigations, including those involving crewmate Senator John Glenn. The mission was accomplished in 134 Earth orbits, traveling 3.6 million miles in 213 hours and 44 minutes. | https://en.wikipedia.org/wiki?curid=635284 | 426,056 |
329,464 | During E3 2015, the company announced "Edge of Nowhere", a third-person action-adventure game for the virtual reality hardware Oculus Rift. In April 2016, the company announced two new virtual reality titles: "Feral Rites", a hack and slash game, and "The Unspoken", a fantasy multiplayer game, for the Oculus Rift. According to Price, the company began focusing on virtual reality projects as the team is enthusiastic about the technology, and that it allows the company to develop an expertise in creating VR games. The studio signed an exclusive deal with Oculus VR as Insomniac believed that both companies shared the same passion to "[bring] games to life", and that they allowed Insomniac to retain the rights of their intellectual properties. Price compared the agreement to their previous first-party deals, and added that having the opportunity to develop games for the first generation of VR platforms is something the team could not reject. Despite the new direction, Price added that they will not give up on making console AAA video games. At E3 2016, Insomniac announced their next AAA title, "Marvel's Spider-Man", developed for the PlayStation 4 in conjunction with Marvel Entertainment. Bryan Intihar, producer of "Sunset Overdrive", was the game's creative director. | https://en.wikipedia.org/wiki?curid=693454 | 329,289 |
459,112 | After traumatic brain injury (TBI), abnormalities have been shown in the PCC. Often, head injuries produce widespread axonal injury that disconnect brain regions and lead to cognitive impairment. This is also related to reduced metabolism within the PCC. Studies of performance on simple choice reaction time tasks after TBI show, in particular, that the pattern of functional connectivity from the PCC to the rest of the DMN can predict TBI impairments. They also found that greater damage to the cingulum bundle, that connects the PCC to the anterior DMN, was correlated with sustained attention impairment. In a subsequent study, it was found that TBIs are related to a difficulty in switching from automatic to controlled responses. Within selected tasks, patients with TBI showed impaired motor inhibition that was associated with failure to rapidly reactive the PCC. Collectively, this suggests that the failure to control the PCC/DMN activity can lead to attentional lapses in TBI patients. | https://en.wikipedia.org/wiki?curid=4254360 | 458,887 |
86,521 | The decidedly anti-Aristotelian and anti-clerical music theorist Vincenzo Galilei (c. 1520 – 1591), father of Galileo and the inventor of monody, made use of the method in successfully solving musical problems, firstly, of tuning such as the relationship of pitch to string tension and mass in stringed instruments, and to volume of air in wind instruments; and secondly to composition, by his various suggestions to composers in his "Dialogo della musica antica e moderna" (Florence, 1581). The Italian word he used for "experiment" was "esperienza". It is known that he was the essential pedagogical influence upon the young Galileo, his eldest son (cf. Coelho, ed. "Music and Science in the Age of Galileo Galilei"), arguably one of the most influential empiricists in history. Vincenzo, through his tuning research, found the underlying truth at the heart of the misunderstood myth of 'Pythagoras' hammers' (the square of the numbers concerned yielded those musical intervals, not the actual numbers, as believed), and through this and other discoveries that demonstrated the fallibility of traditional authorities, a radically empirical attitude developed, passed on to Galileo, which regarded "experience and demonstration" as the "sine qua non" of valid rational enquiry. | https://en.wikipedia.org/wiki?curid=10174 | 86,487 |
927,830 | To bring out the best attributes of letterpress, printers must understand the capabilities and advantages of what can be a very unforgiving medium. For instance, since most letterpress equipment prints only one color at a time, printing multiple colors requires a separate press run in register with the preceding color. When offset printing arrived in the 1950s, it cost less, and made the color process easier. The inking system on letterpress equipment is the same as offset presses, posing problems for some graphics. Detailed, white (or "knocked out") areas, such as small, serif type, or very fine halftone surrounded by fields of color can fill in with ink and lose definition if rollers are not adjusted correctly. However, a skilled printer overcomes most of these problems. However, a letterpress provides the option of a wider range of paper, including handmade, organic, and tree-free. Letterpress printing provides a wide range of production choices. The classic feel and finish of letterpress papers takes printing back to an era of quality and craftsmanship. Even the smell of the ink, more apparent on a letterpress-printed page than with offset, may appeal to collectors. | https://en.wikipedia.org/wiki?curid=662134 | 927,342 |
2,006,450 | Right after occupying Yugoslavia, Germans commandeered the factory on 17 April 1941. The complex was heavily bombed during the massive Allied Easter bombing of Belgrade in April 1944. The facilities of Ikarus were almost completely destroyed during the war, but the factory was rebuilt. In 1946 Zmaj and Rogožarski were merged with the Ikarus, after previously being nationalized. In 1954 the company began producing buses and, starting from 1960, the production of aircraft was being shut down and relocated to the SOKO factory in Mostar, Bosnia and Herzegovina. Production of the aircraft was completely discontinued in 1962 and, until that date, Ikarus produced a total of 475 planes after the war. The facilities were completely demolished and the area is today occupied by the residential buildings, stretching between the Hotel Jugoslavija on the east, and "Palmira Toljatija" Street (roughly blocks 9-A and 11-C. divided between the municipalities of Zemun and New Belgrade). The engineers and the design bureau were transferred to the Aeronautical Technical Institute in the Belgrade's suburb of Žarkovo. The company was ultimately renamed to Ikarbus. | https://en.wikipedia.org/wiki?curid=57747642 | 2,005,301 |
1,942,917 | Indium gallium arsenide antimonide (InGaAsSb) is a compound III-V semiconductor. (InGaAsSb) The addition of GaAs allows for a narrower bandgap (0.5 to 0.6 eV), and therefore better absorption of long wavelengths. Specifically, the bandgap was engineered to 0.55 eV. With this bandgap, the compound achieved a photon-weighted internal quantum efficiency of 79% with a fill factor of 65% for a black body at 1100 °C. This was for a device grown on a GaSb substrate by organometallic vapour phase epitaxy (OMVPE). Devices have been grown by molecular beam epitaxy (MBE) and liquid phase epitaxy (LPE). The internal quantum efficiencies (IQE) of these devices approach 90%, while devices grown by the other two techniques exceed 95%. The largest problem with InGaAsSb cells is phase separation. Compositional inconsistencies throughout the device degrade its performance. When phase separation can be avoided, the IQE and fill factor of InGaAsSb approach theoretical limits in wavelength ranges near the bandgap energy. However, the V/E ratio is far from the ideal. Current methods to manufacture InGaAsSb PVs are expensive and not commercially viable. | https://en.wikipedia.org/wiki?curid=2937772 | 1,941,806 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.