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53,191,245 | https://en.wikipedia.org/wiki/A%20Cancri | The Bayer designation A Cancri is shared by two stars/star systems in the constellation Cancer:
A1 Cancri (45 Cancri)
A2 Cancri (50 Cancri)
See also
α Cancri
Cancri, A
Cancer (constellation) | A Cancri | [
"Astronomy"
] | 57 | [
"Cancer (constellation)",
"Constellations"
] |
53,191,309 | https://en.wikipedia.org/wiki/D%20Cancri | The Bayer designation d Cancri is shared by two star systems in the constellation Cancer:
d1 Cancri (20 Cancri)
d2 Cancri (25 Cancri)
See also
δ Cancri
Cancri, d
Cancer (constellation) | D Cancri | [
"Astronomy"
] | 57 | [
"Cancer (constellation)",
"Constellations"
] |
53,192,145 | https://en.wikipedia.org/wiki/Separation%20of%20prescribing%20and%20dispensing | Separation of prescribing and dispensing, also called dispensing separation, is a practice in medicine and pharmacy in which the physician who provides a medical prescription is independent from the pharmacist who provides the prescription drug.
In the Western world there are centuries of tradition for separating pharmacists from physicians. In Asian countries it is traditional for physicians to also provide drugs.
Contemporary research indicates that separation of prescribing and dispensing lowers expenditure on drugs, which is explained by the fact physician-prescribing gives doctors an incentive to over-prescribe. This is an example of a conflict of interest in the healthcare industry leading to unnecessary health care.
Background
In many Western jurisdictions such as the United States, pharmacists are regulated separately from physicians. These jurisdictions also usually specify that only pharmacists may supply scheduled pharmaceuticals to the public, and that pharmacists cannot form business partnerships with physicians or give them "kickback" payments. In other words, the diagnosing physicians' role is supposed to extend only as far as providing proper prescriptions to patients, who are then entitled to purchase the prescribed drugs at the pharmacies of their choice.
However, the American Medical Association (AMA) Code of Ethics provides that physicians may dispense drugs within their office practices as long as there is no patient exploitation and patients have the right to a written prescription that can be filled elsewhere. 7 to 10 percent of American physicians practices reportedly dispense drugs on their own.
In some rural areas in the United Kingdom, there are dispensing physicians who are allowed to both prescribe and dispense prescription-only medicines to their patients from within their practices. The law requires that the GP practice be located in a designated rural area and that there is also a specified, minimum distance (currently 1 mile; 1.6 kilometres) between a patient's home and the nearest retail pharmacy. See Dispensing Doctors' Association.
This law also exists in Austria for general physicians if the nearest pharmacy is more than 4 kilometers ( miles) away, or where none is registered in the city. Switzerland also allows dispensing physicians in several Kantons.
In other jurisdictions (particularly in Asian countries such as China, Malaysia, and Singapore), doctors are allowed to dispense drugs themselves and the practice of pharmacy is sometimes integrated with that of the physician, particularly in traditional Chinese medicine.
In Canada it is common for a medical clinic and a pharmacy to be located together and for the ownership in both enterprises to be common, but licensed separately.
The reason for the majority rule is the high risk of a conflict of interest and/or the avoidance of absolute powers. Otherwise, the physician has a financial self-interest in "diagnosing" as many conditions as possible, and in exaggerating their seriousness, because he or she can then sell more medications to the patient. Such self-interest directly conflicts with the patient's interest in obtaining cost-effective medication and avoiding the unnecessary use of medication that may have side-effects. This system reflects much similarity to the checks and balances system of the U.S. and many other governments.
A campaign for separation has begun in many countries and has already been successful (as in Korea). As many of the remaining nations move towards separation, resistance and lobbying from dispensing doctors who have pecuniary interests may prove a major stumbling block (e.g. in Malaysia).
Experience in Asian countries
In many Asian countries there is not a traditional separation between physician and pharmacist. In Taiwan, a plan initiated in March 1997 experimented with separating doctors who prescribe from pharmacists who fulfill prescriptions on the theory that this would reduce unnecessary health care. The plan had mixed results. The South Korean government passed a law in 2000 which separated drug prescribing from dispensing. The passing of the law achieved some of its intentions and also caused problems in unexpected ways. Japan also is experimenting with separation of prescribing and dispensing. In Malaysia, , separation of prescribing and dispensing only occurs in government hospitals.
References
Further reading
External links
Medical regulation
Pharmacy
Separation of powers | Separation of prescribing and dispensing | [
"Chemistry"
] | 866 | [
"Pharmacology",
"Pharmacy"
] |
53,193,155 | https://en.wikipedia.org/wiki/Interchange%20instability | The interchange instability, also known as the Kruskal–Schwarzschild instability or flute instability, is a type of plasma instability seen in magnetic fusion energy that is driven by the gradients in the magnetic pressure in areas where the confining magnetic field is curved.
The name of the instability refers to the action of the plasma changing position with the magnetic field lines (i.e. an interchange of the lines of force in space) without significant disturbance to the geometry of the external field. The instability causes flute-like structures to appear on the surface of the plasma, hence it is also referred to as the flute instability. The interchange instability is a key issue in the field of fusion energy, where magnetic fields are used to confine a plasma in a volume surrounded by the field.
The basic concept was first noted in a 1954 paper by Martin David Kruskal and Martin Schwarzschild, who demonstrated that a situation similar to the Rayleigh–Taylor instability in classic fluids existed in magnetically confined plasmas. The problem can occur anywhere where the magnetic field is concave with the plasma on the inside of the curve. Edward Teller gave a talk on the issue at a meeting later that year, pointing out that it appeared to be an issue in most of the fusion devices being studied at that time. He used the analogy of rubber bands on the outside of a blob of jelly; there is a natural tendency for the bands to snap together and eject the jelly from the center.
Most machines of that era suffered from other instabilities that were far more powerful, and whether or not the interchange instability was taking place could not be confirmed. This was finally demonstrated beyond doubt by a Soviet magnetic mirror machine during an international meeting in 1961. When the US delegation stated they were not seeing this problem in their mirrors, it was pointed out they were making an error in the use of their instrumentation. When that was considered, it was clear the US experiments were also being affected by the same problem. This led to a series of new mirror designs, as well as modifications to other designs like the stellarator to add negative curvature. These had cusp-shaped fields so that the plasma was contained within convex fields, the so-called "magnetic well" configuration.
In modern designs, the interchange instability is suppressed by the complex shaping of the fields. In the tokamak design there are still areas of "bad curvature", but particles within the plasma spend only a short time in those areas before being circulated to an area of "good curvature". Modern stellarators use similar configurations, differing from tokamaks largely in how that shaping is created.
Basic concept
Magnetic confinement systems attempt to hold the plasma within a vacuum chamber using magnetic fields. The plasma particles are electrically charged, and thus see a transverse force from the field due to the Lorentz force. When the particle's original linear motion is superimposed on this transverse force, its resulting path through space is a helix, or corkscrew shape. Such a field will thus trap the plasma by forcing it to flow along the lines.
One can produce a linear field using an electromagnet in the form of a solenoid wrapped around a tubular vacuum chamber. In this case, the plasma will orbit the lines running down the center of the chamber and be prevented from moving outward towards the walls. This does not confine the plasma along the length of the tube, and it will rapidly flow out the ends. Designs that prevented this from occurring appeared in the early 1950s and experiments began in earnest in 1953. However, all of these devices proved to leak plasma at rates far higher than expected.
In May 1954, Martin David Kruskal and Martin Schwarzschild published a paper demonstrating two effects that meant plasmas in magnetic fields were inherently unstable. One of the two effects, which became known as the kink instability, was already being seen in early z-pinch experiments and occurred slowly enough to be captured on movie film. The topic of stability immediately gained significance in the field.
The other instability noted in the paper considered an infinite sheet of plasma held up against gravity by a magnetic field. It suggested there would be behaviour similar to that in classical physics when one heavy fluid is supported by a lighter one, which leads to the Rayleigh–Taylor instability. Any small vertical disturbance in an initially uniform field would result in the field pulling on the charges laterally and causing the initial disturbance to be further magnified. As large sheets of plasma were not common in existing devices, the outcome of this effect was not immediately obvious. It was not long before a corollary became obvious; the initial disturbance resulted in a curved interface between the plasma and the external field, and this was inherent to any design that had a convex area in the field.
In October 1954 a meeting of the still-secret Project Sherwood researchers was held at Princeton University's Gun Club building. Edward Teller brought up the topic of this instability and noted that two of the major designs being considered, the stellarator and the magnetic mirror, both had large areas of such curvature and thus should be expected to be inherently unstable. He further illustrated it by comparing the situation to jello being held together with rubber bands; while such a setup might be created, any slight disturbance would cause the rubber bands to contract and eject the jello. This exchange of position appeared to be identical to the mirror case in particular, where the plasma naturally wanted to expand while the magnetic fields had an internal tension.
No such behaviour had been seen in experimental devices, but as the situation was considered further, it became clear it would be more obvious in areas of greater curvature, and existing devices used relatively weak magnetic fields with relatively flat fields. This nevertheless presented a significant problem; a key measure of the attractiveness of a reactor design was its beta, the ratio of magnetic field strength to confined plasma - higher beta meant more plasma for the same magnet, which was a significant factor in cost. However, higher beta also implied more curvature in these devices, which would make them increasingly unstable. This might force reactors to operate at low beta and be doomed to be economically unattractive.
As the magnitude of the problem became clear, the meeting turned to the question of whether or not there was any arrangement that was naturally stable. Jim Tuck was able to provide a solution; the picket fence reactor concept had been developed as a solution to another problem, bremsstrahlung losses, but he pointed out that its field arrangement would be naturally stable under the conditions shown in the Kruskal/Schwarzschild paper. Nevertheless, as Amasa Bishop noted;
The correctness of the simplified model was then called into question and led to further study. The answer appeared at a follow-up meeting at Berkeley in
February 1955, where Harold Grad of New York University, Conrad Longmire of Los Alamos and Edward A. Frieman of Princeton presented independent developments that all proved the effect to be real, and worse, should be expected at any beta, not just high beta. Further work at Los Alamos demonstrated that the effect should be seen in both the mirror and stellarator.
The effect is most obvious in the magnetic mirror device. The mirror has a field that runs along the open center of the cylinder and bundles together at the ends. In the center of the chamber the particles follow the lines and flow towards either end of the device. There, the increasing magnetic density causes them to "reflect", reversing direction and flowing back into the center again. Ideally, this will keep the plasma confined indefinitely, but even in theory there a critical angle between the particle trajectory and the axis of the mirror where particles can escape. Initial calculations showed that the loss rate through this process would be small enough to not be a concern.
In practice, all mirror machines demonstrated a loss rate far higher than these calculations suggested. The interchange instability was one of the major reasons for these losses. The mirror field has a cigar shape to it, with increasing curvature at the ends. When the plasma is located in its design location, the electrons and ions are roughly mixed. However, if the plasma is displaced, the non-uniform nature of the field means the ion's larger orbital radius takes them outside the confinement area while the electrons remain inside. It is possible the ion will hit the wall of the container, removing it from the plasma. If this occurs, the outer edge of the plasma is now net negatively charged, attracting more of the positively charged ions, which then escape as well.
This effect allows even a tiny displacement to drive the entire plasma mass to the walls of the container. The same effect occurs in any reactor design where the plasma is within a field of sufficient curvature, which includes the outside curve of toroidal machines like the tokamak and stellarator. As this process is highly non-linear, it tends to occur in isolated areas, giving rise to the flute-like expansions as opposed to mass movement of the plasma as a whole.
History
In the 1950s, the field of theoretical plasma physics emerged. The confidential research of the war became declassified and allowed the publication and spread of very influential papers. The world rushed to take advantage of the recent revelations on nuclear energy. Although never fully realized, the idea of controlled thermonuclear fusion motivated many to explore and research novel configurations in plasma physics. Instabilities plagued early designs of artificial plasma confinement devices and were quickly studied partly as a means to inhibit the effects. The analytical equations for interchange instabilities were first studied by Kruskal and Schwarzschild in 1954. They investigated several simple systems including the system in which an ideal fluid is supported against gravity by a magnetic field (the initial model described in the last section).
In 1958, Bernstein derived an energy principle that rigorously proved that the change in potential must be greater than zero for a system to be stable. This energy principle has been essential in establishing a stability condition for the possible instabilities of a specific configuration.
In 1959, Thomas Gold attempted to use the concept of interchange motion to explain the circulation of plasma around the Earth, using data from Pioneer III published by James Van Allen. Gold also coined the term “magnetosphere” to describe “the region above the ionosphere in which the magnetic field of the Earth has a dominant control over the motions of gas and fast charged particles.” Marshall Rosenthal and Conrad Longmire described in their 1957 paper how a flux tube in a planetary magnetic field accumulates charge because of opposing movement of the ions and electrons in the background plasma. Gradient, curvature and centrifugal drifts all send ions in the same direction along the planetary rotation, meaning that there is a positive build-up on one side of the flux tube and a negative build-up on the other. The separation of charges established an electric field across the flux tube and therefore adds an E x B motion, sending the flux tube toward the planet. This mechanism supports our interchange instability framework, resulting in the injection of less dense gas radially inward. Since Kruskal and Schwarzschild's papers a tremendous amount of theoretical work has been accomplished that handle multi-dimensional configurations, varying boundary conditions and complicated geometries.
Studies of planetary magnetospheres with space probes has helped the development of interchange instability theories, especially the comprehensive understanding of interchange motions in Jupiter and Saturn’s magnetospheres.
Instability in a plasma system
The single most important property of a plasma is its stability. MHD and its derived equilibrium equations offer a wide variety of plasmas configurations but the stability of those configurations have not been challenged. More specifically, the system must satisfy the simple condition
where ? is the change in potential energy for degrees of freedom. Failure to meet this condition indicates that there is a more energetically preferable state. The system will evolve and either shift into a different state or never reach a steady state. These instabilities pose great challenges to those aiming to make stable plasma configurations in the lab. However, they have also granted us an informative tool on the behavior of plasma, especially in the examination of planetary magnetospheres.
This process injects hotter, lower density plasma into a colder, higher density region. It is the MHD analog of the well-known Rayleigh-Taylor instability. The Rayleigh-Taylor instability occurs at an interface in which a lower density liquid pushes against a higher density liquid in a gravitational field. In a similar model with a gravitational field, the interchange instability acts in the same way. However, in planetary magnetospheres co-rotational forces are dominant and change the picture slightly.
Simple models
Let's first consider the simple model of a plasma supported by a magnetic field B in a uniform gravitational field g. To simplify matters, assume that the internal energy of the system is zero such that static equilibrium may be obtained from the balance of the gravitational force and the magnetic field pressure on the boundary of the plasma. The change in the potential is then given by the equation: ? If two adjacent flux tubes lying opposite along the boundary (one fluid tube and one magnetic flux tube) are interchanged the volume element doesn't change and the field lines are straight. Therefore, the magnetic potential doesn't change, but the gravitational potential changes since it was moved along the z axis. Since the change in is negative the potential is decreasing.
A decreasing potential indicates a more energetically favorable system and consequently an instability. The origin of this instability is in the J × B forces that occur at the boundary between the plasma and magnetic field. At this boundary there are slight ripple-like perturbations in which the low points must have a larger current than the high points since at the low point more gravity is being supported against the gravity. The difference in current allows negative and positive charge to build up along the opposite sides of the valley. The charge build-up produces an E field between the hill and the valley. The accompanying E × B drifts are in the same direction as the ripple, amplifying the effect. This is what is physically meant by the “interchange” motion.
These interchange motions also occur in plasmas that are in a system with a large centrifugal force. In a cylindrically symmetric plasma device, radial electric fields cause the plasma to rotate rapidly in a column around the axis. Acting opposite to the gravity in the simple model, the centrifugal force moves the plasma outward where the ripple-like perturbations (sometimes called “flute” instabilities) occur on the boundary. This is important for the study of the magnetosphere in which the co-rotational forces are stronger than the opposing gravity of the planet. Effectively, the less dense “bubbles” inject radially inward in this configuration.
Without gravity or an inertial force, interchange instabilities can still occur if the plasma is in a curved magnetic field. If we assume the potential energy to be purely magnetic then the change in potential energy is: . If the fluid is incompressible then the equation can be simplified into . Since (to maintain pressure balance), the above equation shows that if the system is unstable. Physically, this means that if the field lines are toward the region of higher plasma density then the system is susceptible to interchange motions. To derive a more rigorous stability condition, the perturbations that cause an instability must be generalized. The momentum equation for a resistive MHD is linearized and then manipulated into a linear force operator. Due to purely mathematical reasons, it is then possible to split the analysis into two approaches: the normal mode method and the energy method. The normal mode method essentially looks for the eigenmodes and eigenfrequencies and summing the solutions to form the general solution. The energy method is similar to the simpler approach outlined above where is found for any arbitrary perturbation in order to maintain the condition . These two methods are not exclusive and can be used together to establish a reliable diagnosis of the stability.
Observations in space
The strongest evidence for interchange transport of plasma in any magnetosphere is the observation of injection events. The recording of these events in the magnetospheres of Earth, Jupiter and Saturn are the main tool for the interpretation and analysis of interchange motion.
Earth
Although spacecraft have travelled many times in the inner and outer orbit of Earth since the 1960s, the spacecraft was the first major plasma experiment performed that could reliably determine the existence of radial injections driven by interchange motions. The analysis revealed the frequent injection of a hot plasma cloud is injected inward during a substorm in the outer layers of the magnetosphere. The injections occur predominantly in the night-time hemisphere, being associated with the depolarization of the neutral sheet configuration in the tail regions of the magnetosphere. This paper then implies that Earth's magnetotail region is a major mechanism in which the magnetosphere stores and releases energy through the interchange mechanism. The interchange instability also has been found to have a limiting factor on the night side plasmapause thickness [Wolf et al. 1990]. In this paper, the plasmapause is found to be near the geosynchronous orbit in which the centrifugal and gravitational potential exactly cancel out. This sharp change in plasma pressure associated with the plasma pause enables this instability. A mathematical treatment comparing the growth rate of the instability with the thickness of the plasmapause boundary revealed that the interchange instability limits the thickness of that boundary.
Jupiter
Interchange instability plays a major role in the radial transport of plasma in the Io plasma torus at Jupiter. The first evidence of this behavior was published by Thorne et al. in which they discovered “anomalous plasma signatures” in the Io torus of Jupiter's magnetosphere. Using the data from the spacecraft Galileo's energetic particle detector (EPD), the study looked at one specific event. In Thorne et al. they concluded that these events had a density differential of at least a factor of 2, a spatial scale of km and an inward velocity of about km/s. These results support the theoretical arguments for interchange transport.
Later, more injections events were discovered and analyzed from Galileo. Mauk et al. used over 100 Jovian injections to study how these events were dispersed in energy and time. Similar to injections of Earth, the events were often clustered in time. The authors concluded that this indicated the injection events were triggered by solar wind activity against the Jovian magnetosphere. This is very similar to the magnetic storm relationship injection events have on Earth. However, it was found that Jovian injections can occur at all local time positions and therefore can't be directly related to the situation in Earth's magnetosphere. Although the Jovian injections aren't a direct analog of Earth's injections, the similarities indicate that this process plays a vital role in the storage and release of energy. The difference may lie in the presence of Io in the Jovian system. Io is a large producer of plasma mass because of its volcanic activity. This explains why the bulk of interchange motions are seen in a small radial range near Io.
Saturn
Recent evidence from the spacecraft Cassini has confirmed that the same interchange process is prominent on Saturn. Unlike Jupiter, the events happen much more frequently and more clearly. The difference lies in the configuration of the magnetosphere. Since Saturn's gravity is much weaker, the gradient/curvature drift for a given particle energy and L value is about 25 times faster. Saturn's magnetosphere provides a much better environment for the study of interchange instability under these conditions even though the process is essential in both Jupiter and Saturn. In a case study of one injection event, the Cassini Plasma Spectrometer (CAPS) produced characteristic radial profiles of plasma densities and temperatures of the plasma particles that also allowed the calculation of the origin of the injection and the radial propagation velocity. The electron density inside the event was lowered by a factor of about 3, the electron temperature was higher by an order of magnitude than the background, and there was a slight increase in the magnetic field. The study also used a model of pitch angle distributions to estimate the event originated between and had a radial speed of about 260+60/-70 km/s. These results are similar to the Galileo results discussed earlier. The similarities imply that the Saturn and Jupiter processes are the same.
See also
Plasma stability
Magnetic mirror
Fusion power
References
Plasma instabilities | Interchange instability | [
"Physics"
] | 4,144 | [
"Plasma phenomena",
"Physical phenomena",
"Plasma instabilities"
] |
53,196,840 | https://en.wikipedia.org/wiki/SN%202013fs | SN 2013fs is a supernova, located in the spiral galaxy NGC 7610, discovered by the Intermediate Palomar Transient Factory sky survey at Palomar Observatory on 6 October 2013 (and originally named iPTF 13dqy). It was discovered approximately three hours from explosion (first light) and was observed in ultraviolet and X-ray wavelengths, among others, within several hours. Optical spectra were obtained beginning at six hours from explosion, making these the earliest such detailed observations ever made of a supernova. The supernova was also independently discovered by Kōichi Itagaki on 7 October 2013.
The star that produced SN 2013fs was a red supergiant with a mass 10 times the mass of the Sun, an effective temperature of 3,500 K, a radius 607 times the size of the Sun, and no more than a few million years old when it exploded. The star was surrounded by a relatively dense shell of gas shed by the star within the year before it exploded. Radiation emitted by the supernova explosion illuminated this shell, which had a mass of approximately one-thousandth the mass of the Sun, and its outer fringe was about five times the distance of Neptune from the Sun.
References
External links
Light curves and spectra on the Open Supernova Catalog
20131006
Supernovae
Pegasus (constellation) | SN 2013fs | [
"Chemistry",
"Astronomy"
] | 269 | [
"Supernovae",
"Pegasus (constellation)",
"Astronomical events",
"Constellations",
"Explosions"
] |
53,197,236 | https://en.wikipedia.org/wiki/LG%20Watch%20Sport | The LG Watch Sport is a smartwatch released by LG Corporation on Feb 09, 2017. The device is one of the first smartwatches to ship with Android Wear version 2.0 with LTE (telecommunication) and Android Pay support.
References
External links
Official Website
Android (operating system) devices
Products introduced in 2017
Wear OS devices
Smartwatches
LG Electronics products | LG Watch Sport | [
"Technology"
] | 77 | [
"Wear OS devices",
"Smartwatches"
] |
53,198,175 | https://en.wikipedia.org/wiki/Genomic%20evolution%20of%20birds | The genomic evolution of birds has come under scrutiny since the advent of rapid DNA sequencing, as birds have the smallest genomes of the amniotes despite acquiring highly derived phenotypic traits. Whereas mammalian and reptilian genomes range between 1.0 and 8.2 giga base pairs (Gb), avian genomes have sizes between 0.91 Gb (black-chinned hummingbird, Archilochus alexandri) and 1.3 Gb (common ostrich, Struthio camelus). Avian genomes reflect the action of natural selection and are the basis of their phenotypes, reflected in their morphology and behaviour, which have evolved significantly since their divergence from other archosaurian, diapsid, and amniotic lineages.
Features of current bird genomes
Compared to other tetrapod lineages, birds have fewer repeated elements in their genomes, comprising only 4–10% of its extent, compared to 34–52% in mammals. The total size of avian short interspersed nuclear elements (SINEs) has been drastically reduced, averaging only 1.3 mega base pairs (Mb), compared to animals in similar lineages: The American alligator (Alligator mississippiensis), a fellow archosaur, averages 12.6 Mb SINEs, and the green sea turtle (Chelonia mydas), a non-archosaur diapsid, averages 34.9 Mb. These data suggest that the last common ancestor of modern birds already had a reduced number of SINEs.
The mean size of introns, intergenic sequences, and even exons is significantly reduced. Mammalian and reptilian introns have an average size of 4.3 kb and 3.1 kb respectively, whereas those of birds are only 2.1 kb long. Likewise, gene spacing averages 91 kb for mammals and 61 kb for reptiles, but only 49 kb in birds. Similar reductions have occurred in bats, suggesting that genome-size reduction is advantageous to flying animals, allowing, for example, the rapid regulation of gene expression required for powered flight. To rule out the possibility of genomic expansion in mammals and reptiles, Zhang et al. (2014) reconstructed successive deletion events in the avian ancestral genome compared to the reptilian.
Birds have experienced the most genomic reductions of any vertebrate group. The early chromosomic fragmentation event that led to the appearance of microchromosomes in birds possibly contributed to this gene loss. These fragmentation events must have taken place in a common ancestor of most birds, since approximately every two out of three species studied have at least 30 pairs of microchromosomes, 2n = 80 being the size of the average karyotype of birds (with the only exception the family Falconidae, which are 2n = 6–12).
Macrosynteny studies have determined that, in vocal learner birds, genes have undergone a deeper rearrangement along their corresponding chromosomes than those of non-vocal learner birds. In addition to that, microsynteny studies revealed that birds possess a higher number of orthologous genes that maintain synteny. This proves that gene order along chromosomes is more conserved in birds than in other animal groups. A clear example are genes coding for haemoglobin subunits. These genes are easily duplicated and lost. As a consequence, there are huge differences regarding the number and relative position of the genes of alpha-hemoglobins and beta-hemoglobins in mammals. In birds, that is not the case. Both position and number of these genes are highly conserved among them.
Birds' point mutation rate (1.9 mutations per site per Ma) is smaller than that of mammals (2.7 mutations per site per Ma). This rate is also smaller among aequornithes (water birds) than that of telluraves (land birds). In this last group, birds of prey have the smallest mutation rate, and songbirds have the highest. These rates are consistent with the broad distribution of birds in different environments and the phenotypic changes in response to selective pressures exerted by the ecological niches they occupy.
The presence of functional restrictions in genome self-regulation can be studied by comparing the genomes of species whose last common ancestor is more ancient. It is known that, approximately, 7.5% of bird genome is comprised by highly conserved elements (HCEs). Of those HCEs, 12.6% are directly involved in protein coding genes functionality. Non-coding HCEs that are bird specific (not found in mammals) happen to be related with the regulation of the activity of transcription factors related to metabolism. In comparison, mammal HCEs are related to controlling cell signalling, development, and response to stimuli.
Evolutionary genomic changes
The rate of genetic variation is not homogeneous across the genome. This can be assayed using Ka/Ks ratio studies (also known as dN/dS) to estimate the balance between neutral mutations, purifying mutations, and beneficial mutations.
In birds, Z-chromosome genes have the highest variability, perhaps due to the low gene density in the Z-chromosome. Genetic variability is higher in macrochromosomes than in microchromosomes, perhaps related to the lower recombination frequency of the latter.
While genes that mediate the development of the central nervous system vary most rapidly in mammals, the genes that mediate morphological development undergoes the most rapid change in avian genomes.
Genome relation to singing
The avian ability to learn songs has appeared independently at least twice: once in the ancestor of hummingbirds and another in the common ancestor of songbirds and parrots. These lineages possess a number of neuronal circuits not found in lineages unable to learn songs. A dN/dS analysis showed conserved evolution in 227 genes, most of which are highly expressed in the regions of the brain that control singing. Furthermore, 20% of them seemed to be regulated by singing.
Genomic evolution of morphological features
To fly, bird ancestors had to undergo a series of changes at the molecular level that translate into changes at morphological level. Approximately half of the genes involved in ossification are known to have been positively selected. Some relevant examples are AHSG, that controls bone mineralization density, and P2RX7, which is associated to bone homeostasis. Their action would be responsible for the differences observed between mammal and bird bones.
Something similar occurs with the respiratory system. In mammals, the total inner volume of lungs changes during ventilation. However, this does not happen in birds. They make the air circulate through their lungs by contracting and expanding their air sacs. Five genes are involved in this process in mammals and birds.
Feathers are one of the most characteristic features of birds, along with the beak. Feathers are formed of α- and β-keratins. Compared to reptiles and mammals, α-keratin protein family has been reduced in birds, whereas β-keratins has expanded enormously. Since every major bird lineage possess at least one protein of each of the six β-keratin groups, it can be said that their last common ancestor already possessed a large diversity of this kind of protein. 56% of β-keratins are feather-specific and can only be found in birds, whereas those that make up scales and claws can also be found in reptiles. The variety and number of copies of these genes seems to correlate with the bird's lifestyle, land birds having a larger variety, and the variety being larger still in domestic birds.
Birds are also known for being toothless. This feature seems to be a consequence of several modifications and deletions which occurred in the exons of the genes implicated in the formation of enamel and dentine. It is thought that the common ancestor of birds already lacked mineralized teeth, and that later genome changes pushed the situation to the current status.
Also, birds have the best vision system known in vertebrates. They have a higher number of photoreceptors, and most birds are tetrachromats. The only exception are penguins, which have only three functional opsin genes (and hence are trichromats). This exception could be related to the aquatic lifestyle, since marine mammals have also lost either one or two cone opsin genes.
In many birds the right ovary has become non-functional. There are two ovary development-related genes, MMP19 and AKR1C3, that have disappeared in birds. The fact that a high number of genes related to spermatogenesis are evolving fast (which does not happen in those related to ovogenensis) suggest that males undergo a stronger selective pressure.
Clarification of early diversification of birds
Rapid genomic sequencing data enabled research into the early evolution and divergence of bird groups and produced a more detailed phylogenetic tree. Earlier phylogenetic reconstructions based on single genes proved inadequate due to incomplete lineage sorting.
The low resolution of single-gene phylogenies, scarcity of coding DNA data, and convergent evolution confused early attempts to reconstruct avian phylogeny. For example, when base pairing errors occur, DNA repair mechanisms favor GC pairs.
Genomic analysis suggests 36 bird lineages arose in a period of 10–15 My, relatively quickly on an evolutionary timescale. That period includes the massive K-Pg extinction event that freed many niches, allowing for the adaptive radiation and diversification of surviving species. The genomic analysis accords with fossil record data and with mammal evolution estimates.
The cladogram from this analysis recovers Accipitriformes as a separate clade from Falconiformes, which traditionally subsumed it.
References
Evolution of birds
Genomics
Evolutionary biology | Genomic evolution of birds | [
"Biology"
] | 2,012 | [
"Evolutionary biology"
] |
53,199,261 | https://en.wikipedia.org/wiki/Assassination%20of%20Kim%20Jong-nam | On 13 February 2017, Kim Jong-nam, the older half-brother of the North Korean leader Kim Jong Un, was assassinated at the Kuala Lumpur International Airport in Malaysia. He had been living abroad since his exile from North Korea in 2003.
Following his visit to the resort island Langkawi, Kim Jong-nam arrived at terminal 2 sometime before 9:00 a.m. to take a 10:50 a.m. AirAsia flight to Macau. At approximately 9:00 a.m., two women sprayed Kim Jong-nam with the VX nerve agent. He died about 15 to 20 minutes later while being transported to the hospital.
The women were identified as Siti Aisyah from Indonesia and Đoàn Thị Hương from Vietnam. Both were charged with the murder of Kim Jong-nam. The murder charges were eventually dropped when it was found that they were unknowingly used for the assassination, although Hương pled guilty to a lesser charge of "voluntarily causing hurt by dangerous weapons or means" and received a sentence of three years and four months. She was released from prison on 3 May 2019.
It is widely believed that Kim Jong-nam was murdered on the orders of Kim Jong Un. Four North Korean suspects, later confirmed as spies, left the airport shortly after the assassination and reached Pyongyang without being arrested. Other North Koreans were arrested but were released without charge.
Attack
Kim Jong-nam arrived in Malaysia on 6 February 2017, traveling to the resort island of Langkawi on 8 February. On 13 February, at about 9 am, he was approached by two women, one of whom was Vietnamese while the other was Indonesian, and ambushed with VX nerve agent near an airport self check-in kiosk at level 3, departure hall in KLIA 2, the low-cost carrier terminal at Kuala Lumpur International Airport while waiting for a 10:50 a.m. AirAsia flight to Macau. VX is a chemical weapon banned by the Chemical Weapons Convention of 1993. North Korea, which has not ratified the convention, is suspected of holding a stockpile.
Malaysian police said that Kim had alerted an airport receptionist, saying that "someone had grabbed him from behind and splashed a liquid on his face" and a woman "covered his face with a cloth laced with a liquid".
A resuscitation device was strapped to Kim's face, and he was then transported by stretcher through the airport to reach an ambulance. He was treated at the airport in the Menara Medical Clinic by nurse Rabiatul Adawiyah Mohd Sofi and Dr. Nik Mohd Adzrul Ariff Raja Azlan, who later testified that he was sweating, in pain and unresponsive. At the clinic, Kim was given 1 mg of atropine, and also adrenaline. He was given tracheal intubation. He died about 15 to 20 minutes after the attack while being transferred from the airport to the Putrajaya Hospital.
As he was traveling under the pseudonym "Kim Chol", Malaysian officials did not immediately formally confirm that Kim Jong-nam was the man killed. Kim's extensive Facebook use under this pseudonym since at least 2010, and use of commercial email services for communications, may have made it easier for North Korean agents to seek his whereabouts and track his movements. At the time of his death, Kim's backpack contained approximately $100,000 in cash and he was carrying four North Korean passports, all bearing the name Kim Chol.
On 15 February, Malaysian police arrested 28-year-old Vietnamese woman Đoàn Thị Hương at Kuala Lumpur International Airport in connection with the attack. Hương was identified through CCTV footage. On 16 February, a 25-year-old Indonesian woman named Siti Aisyah was arrested and identified as the second female suspect. Aisyah's boyfriend, a 26-year-old Malaysian named Muhammad Farid bin Jalaluddin, was also arrested on 16 February to assist in the investigation.
Hương told the police that she was instructed by four men who were traveling with them to spray Kim with an unidentified liquid while Aisyah held and covered his face with a handkerchief as part of a prank. CCTV footage showed that Hương and Aisyah rushed to separate restrooms after carrying out the attack, and that they headed to the airport taxi stand after leaving the restrooms. Hương was seen leaving the airport by taxi at around 9:30 a.m. Hương claimed that after she returned to look for the others, they had disappeared and thus she decided to head back to the airport.
On 17 February, police arrested a 46-year-old North Korean man named Ri Jong-chol. He was described as an IT worker for Tombo Enterprise, living in Malaysia.
International reactions
South Korea
Kim Myung-yeon, a spokesperson for South Korea's Liberty Korea Party, described the killing as a "naked example of Kim Jong-un's reign of terror." The South Korean government drew a parallel with the execution of Kim Jong-un's own uncle and others. The acting President of South Korea, Hwang Kyo-ahn, said that if the murder was confirmed to be masterminded by North Korea, that would clearly depict the brutality and inhumanity of the regime.
United States
North Korea was relisted as a state sponsor of terrorism by the United States on 20 November 2017, with the assassination cited as one of the reasons.
In March 2018, the United States Department of State imposed additional sanctions on North Korea, having asserted that North Korea used VX nerve agent to assassinate Kim Jong-nam.
On 10 June 2019, after the trial, The Wall Street Journal reported that former US officials stated Kim had been a CIA source. A book by Anna Fifield, The Washington Post bureau chief in Beijing, had earlier reported this, stating he had been previously filmed abroad with a US intelligence agent, and had carried a backpack that contained $120,000 in cash.
Apology from North Korean officials to Vietnam
On 12 December 2018, it was reported that North Korean officials had informally apologized to Vietnam for involving a Vietnamese woman in the assassination following Vietnam's demands for an official apology and threats to sever diplomatic ties.
Other reactions
The Executive Council of the Organisation for the Prohibition of Chemical Weapons (OPCW) expressed "grave concern"
over the incident and called for those responsible for the use of chemical weapons to be held accountable.
Autopsy
An autopsy was conducted despite North Korean diplomats objecting to any such procedure on Kim's body. Malaysian officials later commented that the autopsy proceeded as the North Korean diplomats failed to submit a formal protest. A post-mortem on Kim was conducted on 15 February at the Kuala Lumpur Hospital mortuary in the presence of several North Korean officials, and concluded the following day with formally confirming the identity of Kim's body. The autopsy was conducted by pathologist Mohamad Shah Mahmood of Kuala Lumpur Hospital, who testified that Kim's lungs, brain, liver and spleen were affected by the poison. Chemical pathologist Nur Ashikin Othman testified that Kim's urine showed the effects of being exposed to the poison. Low levels of cholinesterase indicated that Jong-nam had been exposed to an insecticide or nerve agent. Forensic consultant Dr. Nurliza bte Abdullah testified that Jong-nam's pupil constriction, and the feces in his underwear, suggested he had been poisoned.
On 24 February, Malaysia's police chief Khalid Abu Bakar announced that a post-mortem toxicology report had found traces of the nerve agent VX on Kim's face. According to experts, the use of VX may explain why two assailants were involved, because the assailants "could have wiped two or more precursors" in Kim's face. This is referred to as a binary chemical weapon. This method could ensure that the assailants were not themselves killed by the poison, which can be fatal in very small amounts; additionally, smuggling the chemical components into Malaysia separately could have helped avoid detection. Aisyah reported she vomited in the taxi afterward and has continued to feel unwell.
Chemical weapons experts Jean-Pascal Zanders and Richard Guthrie noted that the reported effects were not entirely consistent with the potency of VX—Kim was able to walk to the medical station without suffering spasms, paramedics were not affected, the assailants survived and there were no other reports of injury even though the scene of the attack was not cleaned for over a week. VX degrades rapidly in storage and North Korea's supplies are believed to be several years old, which could explain the apparent weakness of the chemical.
On 10 March, police completed the autopsy, confirming that the deceased was Kim Jong-nam based on DNA provided by his son Kim Han-sol, and the body was handed to the Ministry of Health for further action. The Health Ministry said they would then give Kim's family two to three weeks to claim his body, with the body having been embalmed to preserve it during the period. The family, however, declined to take the body and gave the Malaysian authorities permission to manage the remains. Over objections of Kim Han-sol, the body was flown to Pyongyang on 31 March. Kim Jong-nam's blazer, backpack and watch were initially submitted to a police chemistry department for analysis, but subsequently returned to officials from the North Korean embassy.
Diplomatic protest
Following Malaysia's refusal to release the body immediately, North Korea's ambassador Kang Chol accused Malaysia of collaborating with the country's enemies over the assassination of Kim Jong-nam. The ambassador said they would reject the outcome of the post-mortem conducted "on its citizen without permission" and perceived the decision as a "violation of human rights" and thus would lodge a complaint to the International Court of Justice (ICJ). The ambassador was summoned by the government of Malaysia on 20 February, while the Malaysian ambassador to North Korea was recalled.
The ambassador then responded that they could not trust the investigation conducted by the Malaysian police, noting there had been no evidence of the cause of death even a week after the attack. He also proposed that North Korea and Malaysia open a joint investigation together in order to prevent influence from South Korea which, he said, was trying to malign North Korea as the party responsible for the killing. Malaysian Prime Minister Najib Razak responded to the ambassador that his country would be objective during the investigation, rejecting the request for joint investigation. On 22 February, Malaysian police said there was evidence of an attempted break-in at the mortuary where Kim's body was being held.
The North Korean government rejected all findings, accused the Malaysian police of fabricating evidence in collusion with South Korea and demanded the release of the three people being held in connection with the death.
North Korean–Malaysian dispute
On 28 February, the North Korean government dispatched a high level delegation to Malaysia. North Korea said the claim that VX nerve agent was used to kill one of its citizens was "absurd" and lacked scientific basis, portraying it as an allegation jointly made by the United States and South Korea to tarnish its image, adding that the death was caused by a "heart attack" as Kim Jong-nam has a record of heart disease. The North Koreans stressed that if it was indeed caused by the chemical, it should be proven by the Organisation for the Prohibition of Chemical Weapons. Malaysian police immediately rejected the North Korean claims. However, in a statement released by the Malaysian Foreign Ministry, the country said it was already co-operating with OPCW.
Malaysia announced that from 6 March they would cancel visa-free entry for North Koreans, citing "security issues". On 4 March, the North Korean ambassador Kang Chol was declared persona non grata and asked to leave within 48 hours with a similar move having been imposed by North Korea towards the Malaysian ambassador. The North Korean authorities also reacted on 7 March by barring all Malaysian citizens in North Korea from leaving. Malaysian authorities imposed reciprocal measures, prohibiting North Korean citizens from leaving Malaysia.
On 30 March, former-Malaysian Prime Minister Najib Razak said that all Malaysians in North Korea as well as North Koreans in Malaysia would be allowed to return to their home countries after the receipt of a letter from Kim's family requesting his remains be returned to North Korea.
Attempts to restore diplomatic relations
Following the 2018 North Korea–United States Summit held in Singapore on 12 June 2018, the new Malaysian-led government of Pakatan Harapan under Prime Minister Mahathir Mohamad said:"the world should not treat North Korea leader Kim Jong-un with skepticism and instead learn from his new attitude towards bringing about peace".In a joint press conference in Tokyo, Japan, he said: "We hoped for a successful outcome from the historic meeting", adding that "Malaysia will re-open their embassy in North Korea as an end to the diplomatic row over the assassination of Kim Jong-nam". On 13 February 2019, Mahathir said that Malaysia will settle its problem with North Korea soon after the 2019 North Korea–United States Vietnam Summit held in Hanoi, Vietnam on 27–28 February 2019 but after the changing of leadership, no major statement has been issued since.
Further investigations
According to lead police investigator Wan Azirul Nizam Che Wan Aziz, Kim Jong-nam told a friend that he feared his life was in danger six months before the assassination.
One of the suspects, Siti Aisyah, had been in Malaysia at least a day before the attack, reportedly to celebrate her birthday with her friends. Aisyah was a divorced mother who worked as a spa masseuse in Kuala Lumpur. She regularly returned to Indonesia to meet her mother and son. She told her mother that she found a better job as an actor in prank video for the Chinese market. After Hương and Aisyah were arrested, they claimed they thought they were participating in a prank. According to both suspects, they were told to play harmless tricks on people in the vicinity for a prank TV show, one target being Kim Jong-nam. They said they were promised US$100, but after losing contact with their handlers, they never received the money.
According to their lawyers, Hương was recruited in December 2016 in Hanoi, Vietnam, while Aisyah was recruited in January 2017 by a Malaysian scout working for the North Koreans. The women were handled by separate teams of North Korean men, who posed as being from Japan and China, one of the recruiters being Ri Ji-u. Since their recruitment, Aisyah had performed the prank on at least 10 occasions. She was flown to Phnom Penh to perform the prank three times with an offer of US$200, while Hương performed it four times in locations including the airport terminals and Mandarin Oriental hotel in Kuala Lumpur. The prank involved approaching unsuspecting men and putting hands on their faces or kissing them on the cheek, then apologising before running away. Then Ri Ji-u said that a new actress and actor would join them for the airport prank. He described the actor as a fat and bald man with a "black bag and jacket", matching Kim's description on the day of his death. The Malaysian police retrieved a photo of "James" from Siti Aisyah's phone. He was later identified as Ri Ji-u. The police searched for him but he was already in the North Korean embassy.
On 19 February, Malaysian police named four more North Korean suspects. They were identified as Ri Ji-hyon (aged 33), Hong Song-hak (34), O Jong-gil (55) and Ri Jae-nam (57), all of whom left Malaysia after the attack, and the Malaysian police requested help from Interpol and other relevant authorities in tracking them. According to an unnamed source, the four suspects flew to Jakarta, Dubai and Vladivostok before reaching Pyongyang. Three other male North Korean suspects were still in Malaysia: Ri Ji-u, who had lived in Malaysia for three years; Kim Uk-il, an employee of Air Koryo; and Hyon Kwang-song, the second secretary at the North Korean embassy. These suspects had taken refuge in the North Korean embassy.
On 22 February, Malaysia Royal Police Chief Khalid Khalid Abu Bakar said that the killing was "a planned effort" and that the two women arrested had been trained to carry out the attack and had repeatedly rehearsed it together at Pavilion Kuala Lumpur and Kuala Lumpur City Centre (KLCC). Khalid also alleged that the women apparently knew they were handling poisonous substances. That same day, an unnamed Malaysian man believed to be a chemist was picked up by police during a raid on a condominium where he then led police to another condominium where various chemicals were seized.
On 28 February, both women were charged with murder, which carries a mandatory death sentence. A lawyer for Hương requested a second autopsy as he doubted Malaysian expertise, calling for experts from Japan and Iraq as well pathologists from North Korea itself to be involved. The Malaysian police responded by telling the lawyer to appeal to the high court.
On 3 March, the only detained North Korean suspect, Ri Jong-chol, was released and deported due to lack of evidence. While in transit through China, he told the media that the Malaysian police threatened to hurt his family if he did not confess his involvement in the murder and said his arrest was part of a "conspiracy". Malaysian police strongly denied his allegation.
On 16 March, Interpol issued a red notice for the four North Korean suspects who had fled to Pyongyang. The three North Korean suspects, Ri Ji-u, Kim Uk-il and Hyon Kwang-song, who were holed up in the North Korean embassy in Malaysia, were released on 30 March and allowed to return home after investigators interviewed them and cleared them of any wrongdoing.
On 22 March, Yonhap News Agency released information stating that Ri Ji-hyon, one of the four suspects who left Malaysia after the attack (the man with a cap on the photo from the airport CCTV), is the son of former North Korean ambassador to Vietnam Ri Hong. From November 2009, he worked as a trainee diplomat in Hanoi for more than a year before becoming an interpreter for another few years. With his ability to converse fluently in the Vietnamese language, he is suspected of having seduced and lured the Vietnamese national Hương into a fake TV prank, making her believe that he is a rich South Korean man. On the request of the Judicial Authorities of Malaysia, Interpol had published a red notice for Ri Ji-hyon for his involvement in the murder plot.
According to the forensics investigation, Kim had a Dell laptop which had accessed data stored on a USB pen drive while he was in Langkawi, though the pen drive was not in his possession when he died.
Murder trial
The murder trial of Siti Aisyah and Đoàn Thị Hương began on 2 October 2017, at the High Court in Shah Alam, Selangor, Malaysia, with both pleading not guilty. Judge Datuk Azmi Ariffin was the presiding judge.
A Malaysian government chemist testified before the court that VX degradation products were found on the two women. The testimony was the first evidence to provide a link between the defendants and the VX nerve agent. Claims by North Korean authorities that Kim had died of a heart attack were disputed by pathologist Mohamad Shah Mahmood, who told the court there was no evidence of a heart attack on autopsy and that post-mortem toxicology reports showed VX was the sole cause of death. Under cross-examination by both defense lawyers, Mohamad, however, acknowledged he had limited knowledge of nerve agents in general and said he did not know the amount of the poison that was used.
Another chemical pathologist, Nur Ashikin Othman, told the court that Kim had very low blood levels of cholinesterase, the enzyme inhibited by anticholinesterase agents such as VX. She also stated that cholinesterase levels were within the normal range for both defendants, but that this did not rule out the possibility they had been in contact with VX. Tengku Ampuan Rahimah Hospital doctor Ranjini Sivaganabalan, a specialist in poisons, testified that VX may not be fatal in very low dosages and disagreed with an assertion that as little as 10 milligrams of VX would be lethal to humans, and claimed that a person with VX on their hands may not be fully decontaminated by washing it off with soap and water. Toxicologist K. Sharmilah testified that vials of atropine, a drug used as an antidote to poisoning with nerve agents such as VX, were found in Kim Jong-nam's bag. On 8 October, the trial had to be moved to a high-security laboratory due to the danger posed by the nerve agent-tainted clothing admitted into evidence.
Police investigator Wan Azirul identified four suspects in the CCTV images as Mr. Chang (identified as Hong Song-hac), Mr. Y (Rhi Ji-hyon), James (O Jong-gil), and Hanamori (a.k.a. "Grandpa" and "Uncle") (Ri Jae-nam). The men were not arrested because Malaysian police did not have sufficient information to identify or locate the suspects, according to investigating officer Wan Azirul and Deputy Public Prosecutor Wan Shaharuddin Wan Ladin.
When the trial resumed in January 2018, Justice Azmi Ariffin ruled that certain CCTV records could not be admitted as evidence. On 14 March, Hương's lawyer, Hisyam Teh Poh Teik, presented a recorded statement from Nguyễn Bích Thủy, a bar owner and Hương's friend, to the Vietnamese police on 1 March 2017, detailing how Hương was recruited by a man named as "Li" (identified as Rhi Ji-hyon). Through the statement, Thủy said:
During the cross examination, the defence lawyer also produced an affidavit Thủy had made the previous October that also contained her police statement. The Malaysian police lead investigator Wan Azirul then came under fire from the lawyer after he admitted not seeking out Thủy even though the accused (Hương) had mentioned her in her statement, with the lawyer said "In doing an investigation you are supposed to look for the truth, but your investigation is only focused on the CCTV footage. The truth is there (in Vietnam) but no one in Malaysia is interested". The lawyer also told that in November he had asked the Malaysian attorney general's office for assistance in convincing Thủy to travel to Malaysia to testify about her role in introducing Hương to the North Korean man. The request was however declined when another attorney representing Hương, Salim Bashir said "It's unfortunate that the attorney general declined to exercise his power to do this and in doing that deprived us of having the opportunity for police to go to Vietnam and investigate". Salim added that the fact that security videos showed Hương appeared to be touching her hair briefly after approaching Kim and going to a toilet farther away to wash her hands showed an "innocent mind" and not the conduct of someone who knew she had poison on her hand. According to lawyer Hisyam, Thủy also turned down efforts by Vietnamese police and defence lawyers to travel to Malaysia to testify for Hương, citing her responsibility in running her bar with her husband and taking care of her young child.
Meanwhile, on the Siti Aisyah side according to her lawyer Gooi Soon Seng, he slammed Malaysian investigators for not allowing him to meet Aisyah during her 14-day remand and not releasing portions of the video linked to the attack as well for the authorities failure to copy all the footage from the CCTV server of the airport which compromised the defence of Aisyah. The lawyer blamed the police for not publishing the entire incident of the video during the attack as it was seen during the trials that police had deliberately cut off the key moments of the killing from the video that the accused (Aisyah) was adjusting glasses after attacking the victim (to which the footage of Aisyah wearing sunglasses was dropped as evidence is not appropriate when police are trying to convict his client of murder). The lawyer adding that police has failed to investigate crucial evidence such as Aisyah's jeans and glasses that were not sent for lab tests. Based on a chemistry department test also showing that Aisyah's finger nail cuttings, nail swabs and blood found no traces of VX.
Both defence lawyers agreed that their clients did not know they were handling poison and made a scapegoat moreover with the absence of the four North Korean suspects. Through the trial from 20 March, Hisyam screened a video of CCTV recorded at Noi Bai International Airport on 2 February 2017, on her client played a prank on a Vietnamese government official named Trịnh Ngọc Linh in Hanoi less than two weeks before the attack, which showed her approaching the man from behind and putting her arms around his neck. Another video screened by the lawyer showing Hương acting as the victim of pranks played by a Vietnamese filmmaker, Nguyễn Mạnh Quang (also known as Quang Bek). Through an affidavit made by Quang, Quang said he had hired Hương to act in the video, which recorded in 2016. The lawyer then explained that "these videos explain why the accused identified herself as an actress" and questioned police investigator Wan Azirul if he "made some efforts to track Quang after receiving affidavits and ask if the task was important or that it was a waste of time" which was replied by "no efforts was made and agreeing to the latter question". The Malaysian police investigator however deny the blame that with the absence of four North Korean suspects their investigation had caused prejudice, insisting that "as for the case, the main perpetrators who committed the killing are the two accused", as well denying on the accusation that Malaysian police did not take adequate measures to pursue the four men, stressing that Interpol had issued an alert for the four men to be arrested based on Malaysia's request. After being questioned by another Hương lawyer Naran Singh during the session hearing, the police investigator admitted there was a mistake in his investigation due to pressure from previous Malaysian police Chief Khalid though Wan Azirul still declining the claim that his investigation is controlled by his superior.
Closing arguments in the trial began on 27 June 2018. On 16 August, the Malaysian court has decided to continue the trial on 1 November until April 2019, with the judge saying that "a political assassination cannot be ruled out" although there was not enough evidence to say, adding that security camera footage "showed that they had the knowledge that the liquid on their hands was toxic and there was no hidden crew and no attempt to bring the person in on the joke afterward, as is common in reality TV prank shows". Both of the accused are then being called to enter their defense since the trial would take another few months before a final verdict is reached. On 1 September, the Malaysian police are tracking down two Indonesian women who are willing to testify on the case.
On 28 January 2019, the trial was postponed to March.
Dismissal of murder charges
Release of Siti Aisyah
In March 2019, Siti Aisyah was released after her murder charge was dismissed. Both the Indonesian and Vietnamese media later revealed that her release was due to a request letter sent by the Indonesian government, which had received a response from Malaysian attorney general Tommy Thomas. This was later admitted by Thomas and confirmed by Reuters, though Thomas refused to respond to other media sources when asked to comment on the decision.
On 13 March, Minister in the Prime Minister's Department Liew Vui Keong further explained that the power to dismiss charges against any individual in Malaysia rests with the nation's attorney general as established in the constitution. Despite similar callings from the Vietnamese government to release Đoàn Thị Hương in the manner of the Indonesian suspect, Malaysian prosecutors rejected the request and said the trial would continue to proceed with a postponement until 1 April due to Hương's poor health and psychological condition—she had not slept for three nights following the Malaysian attorney general's decision to drop the charges against Aisyah.
Reactions
Hương's defence lawyers felt the Malaysian government was practicing discrimination in the judiciary system since the court previously stated that it found a prima facie case against both suspects but only released one. They provided reasons for doing so, such as "taking consideration of good relations between Indonesia and Malaysia thus agreed to the passage of nolle prosequi for Aisyah", as evidenced from the discovery of the hidden letter delivered by the attorney general of Malaysia to the Indonesian Ministry of Law and Human Rights as a response towards their appeal request. The Malaysian attorney general's different treatment towards the two suspects attracted criticism from Ramkarpal Singh, the Malaysian Member of Parliament for Bukit Gelugor. Ramkarpal felt that Thomas's refusal to withdraw the murder charge against the second suspect was "mind boggling and raises questions about the powers of attorney general in the country". He further stated:
Vietnamese Foreign Affairs Ministry spokeswoman Lê Thị Thu Hằng regretted the Malaysian attorney general's decision and called for a fair trial on the case. Her statement was echoed by other Vietnamese ministers, including Foreign Minister Phạm Bình Minh, Deputy Foreign Minister Nguyễn Quốc Dũng, and Vietnamese ambassador to Malaysia Lê Quý Quỳnh. The release of Siti Aisyah "sparked anger in Malaysia", with sources suggesting that the release was a result of political lobbying and "diplomatic pressure" from the Indonesian government; Malaysian Prime Minister Mahathir Mohamad "denied that the Malaysian government caved in to diplomatic pressure", claiming that he had "no information" regarding the assassination and that the release was done based on the "rule of law".
Bridget Welsh, a Southeast Asia expert with John Cabot University, predicted that the decision will risk a "thorny bilateral problem with Vietnam if there is no similar treatment towards their citizen". Malaysian Chinese Association (MCA) President Wee Ka Siong expressed concern over possible meddling in the trial outcome. According to Wee, he had obtained a reply to his written question during a Parliament session in Malaysia, where Prime Minister Mahathir said that the attorney general could still follow his directive even though the attorney general had the discretion to decide on the timeline for criminal prosecution procedures. His statement was followed by MCA spokeswoman Chan Quin Er, who echoed Ramkarpal's statements and stressed that "Malaysian laws should not discriminate" and everyone "is equal before the law".
Outgoing Malaysian Bar president George Varughese expressed that "the Attorney General has the prerogative to drop charges", but "it would be good if the Attorney General could give his reasons for dropping the charges" to avoid speculation. Other Malaysian lawyers viewed the decision as discriminatory against Hương—not only in the sense of Malaysia's justice system, but also to the public (who mostly wanted a fair, transparent trial), as voiced by lawyer Nur Hannan Ishak.
Sentencing and release of Đoàn Thị Hương
On 1 April 2019, the murder charge against Hương was dropped, and she pleaded guilty to the lesser charge of "voluntarily causing hurt by dangerous weapons or means." She was sentenced to three years and four months in prison, but received a one-third reduction in her term, and was released on 3 May.
See also
North Korea's illicit activities
List of assassinations
Notes
References
External links
2010s in Kuala Lumpur
2017 murders in Malaysia
Kim Jong-nam
Chemical terrorism
Kim Jong-nam
February 2017 crimes in Asia
February 2017 events in Malaysia
Kim Jong-nam
Filmed killings in Asia
Kim family (North Korea)
Kuala Lumpur International Airport
Malaysia–North Korea relations
Targeted killing
Terrorism committed by North Korea | Assassination of Kim Jong-nam | [
"Chemistry"
] | 6,603 | [
"Chemical terrorism"
] |
53,199,888 | https://en.wikipedia.org/wiki/Intectin | Intectin is a Ly-6 family protein which is anchored to glycosylphosphatidylinositol on intestinal epithelial cells. Intectin has been shown to maintain the integrity of the intestinal wall by inducing apoptosis of intestinal epithelial cells upon exposure to dietary palmitic acid. Mice treated with the prebiotic oligofructose showed improved intestinal homeostasis as indicated by increased intectin.
References
Proteins | Intectin | [
"Chemistry"
] | 100 | [
"Biomolecules by chemical classification",
"Proteins",
"Molecular biology"
] |
53,201,672 | https://en.wikipedia.org/wiki/F%20Puppis | The Bayer designations F Puppis and f Puppis are distinct and refer to two different stars in the constellation Puppis:
F Puppis (HD 57240)
f Puppis (HD 61330)
Puppis, f
Puppis | F Puppis | [
"Astronomy"
] | 50 | [
"Puppis",
"Constellations"
] |
53,201,736 | https://en.wikipedia.org/wiki/M%20Puppis | The Bayer designations m Puppis and M Puppis are distinct. Due to technical limitations, both designations link here. For the star
m Puppis, see PU Puppis
M Puppis, see HD 57197
Puppis, m
Puppis | M Puppis | [
"Astronomy"
] | 51 | [
"Puppis",
"Constellations"
] |
53,201,806 | https://en.wikipedia.org/wiki/W%20Puppis | The Bayer designations W Puppis and w Puppis are distinct and refer to two different stars in the constellation Puppis:
W Puppis (HR 3002), a red giant star.
w Puppis (CD-32°5185, FK5 1219, GC 11400, GSC 07126-03938, HIP 40945, HR 3282, HD 70555, SAO 199118) an orange giant star
Puppis, w
Puppis | W Puppis | [
"Astronomy"
] | 99 | [
"Puppis",
"Constellations"
] |
53,202,151 | https://en.wikipedia.org/wiki/Eyeball%20network | Eyeball network is a slang term used by network engineers and architects that refers to an access network whose primary users use the network to “look at things” (browse the Internet, read email, etc.) and consume content, as opposed to a network that may be used primarily to generate its own data, or “content networks/providers”.
The term “eyeball network” is often overheard in conversations and seen in articles that discuss peering relationships between other networks, as well as net neutrality issues.
An example of an eyeball network would be any given ISP that provides internet connectivity to end-users – The ISP may peer with Google (which is a content provider) where the end users consume content serviced/provided by Google, in this case the ISP is just an “eyeball network” providing a means for the end user to reach Google provided actual content.
However, it is to be noted that not all ISPs are eyeball networks, they can be pure transit providers. With Tier 2 networks and lower, they can serve as both an eyeball network and a transit provider, depending on their business model. In the modern day ecosystem where peering is given priority, the lines are blurred between the different types of networks as ultimately any given network must be able to reach every other given network on the internet at large.
References
Computer engineering
Computer networking
Slang | Eyeball network | [
"Technology",
"Engineering"
] | 278 | [
"Electrical engineering",
"Computer networking",
"Computer science",
"Computer engineering"
] |
59,466,172 | https://en.wikipedia.org/wiki/Geophis%20dunni | Geophis dunni, Dunn's earth snake, is a species of enigmatic snake in the family Colubridae. The species is presumably endemic to Nicaragua and is only known from a single specimen discovered in 1932. This specimen, the holotype, was discovered by Karl Patterson Schmidt in the stomach of a Central American coral snake, and no additional specimen has been seen since. The holotype has a snout-to-vent length (SVL) of , a tail length of , and a total length of . It is part of the Geophis sieboldi species group according to Floyd Leslie Downs. This species was named by Schmidt after fellow herpetologist Emmett Reid Dunn "in allusion to his important contributions to our knowledge of this group of snakes".
This species is little known for several reasons. Snakes of the genus Geophis are fossorial and nocturnal, and as such are rarely observed in their natural habitat even by those actively searching for them. Also, the snakes of this genus form extensive species complexes in which the only way to tell them apart is by slight differences. For example, Geophis dunni differs from other species by having 17 dorsal scale rows, 8 infralabial scales, and 140 ventral scales. Additionally, the type locality given by Schmidt is very vague, only being "Matagalpa, Nicaragua". Matagalpa is both a city and a municipality, and no data for elevation or habitat type were specified either. However, Downs would mark a location in north Nicaragua at an elevation of as being the type locality of this snake, but this location is exactly the city of Matagalpa and has been questioned by other papers on its accuracy. As of 2022, Geophis dunni remains "data deficient" until another individual is collected and a habitat is identified.
Reproduction
G. dunni is oviparous.
References
Geophis
Snakes of Central America
Reptiles of Nicaragua
Endemic fauna of Nicaragua
Taxa named by Karl Patterson Schmidt
Reptiles described in 1932
Species known from a single specimen | Geophis dunni | [
"Biology"
] | 419 | [
"Individual organisms",
"Species known from a single specimen"
] |
59,466,481 | https://en.wikipedia.org/wiki/International%20Conference%20on%20Learning%20Representations | The International Conference on Learning Representations (ICLR) is a machine learning conference typically held in late April or early May each year. Along with NeurIPS and ICML, it is one of the three primary conferences of high impact in machine learning and artificial intelligence research.
The conference includes invited talks as well as oral and poster presentations of refereed papers. Since its inception in 2013, ICLR has employed an open peer review process to referee paper submissions (based on models proposed by Yann LeCun). In 2019, there were 1591 paper submissions, of which 500 accepted with poster presentations (31%) and 24 with oral presentations (1.5%). In 2021, there were 2997 paper submissions, of which 860 were accepted (29%).
Locations
ICLR 2025, Singapore
ICLR 2024, Vienna, Austria
ICLR 2023, Kigali, Rwanda
ICLR 2022 (virtual conference)
ICLR 2021, Vienna, Austria (virtual conference)
ICLR 2020, Addis Ababa, Ethiopia (virtual conference)
ICLR 2019, New Orleans, Louisiana, United States
ICLR 2018, Vancouver, Canada
ICLR 2017, Toulon, France
ICLR 2016, San Juan, Puerto Rico, United States
ICLR 2015, San Diego, California, United States
ICLR 2014, Banff National Park, Canada
ICLR 2013, Scottsdale, Arizona, United States
See also
ICML
NeurIPS
AAAI Conference on Artificial Intelligence
References
External links
Official website
Artificial intelligence conferences
Signal processing conferences
International conferences in Canada | International Conference on Learning Representations | [
"Technology"
] | 314 | [
"Computing stubs",
"Computer conference stubs"
] |
59,468,239 | https://en.wikipedia.org/wiki/Phenylmercuric%20nitrate | Phenylmercuric nitrate is an organomercury compound with powerful antiseptic and antifungal effects. It was once commonly used as a topical solution for disinfecting wounds, but as with all organomercury compounds it is highly toxic, especially to the kidneys, and is no longer used in this application. However it is still used in low concentrations as a preservative in eye drops for ophthalmic use, making it one of the few organomercury derivatives remaining in current medical use.
See also
Merbromin
Phenylmercury acetate
Phenylmercuric borate
Thiomersal
References
Antiseptics
Organomercury compounds | Phenylmercuric nitrate | [
"Chemistry"
] | 149 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
59,468,795 | https://en.wikipedia.org/wiki/Tub%C3%A2 | Tubâ () is a traditional Filipino palm wine made from the naturally fermented sap of various species of palm trees. During the Spanish colonial period, tubâ was introduced to Guam, the Marianas, and Mexico via the Manila galleons. It remains popular in Mexico, especially in the states of Colima, Jalisco, Michoacán, Nayarit, and Guerrero. Tubâ was also introduced to the Torres Strait Islands of Australia in the mid-19th century by Filipino immigrant workers in the pearling industry.
History
Tubâ has existed in the Philippines since pre-colonial times. It was widely consumed for recreation as well as having ritual significance in animist religious ceremonies performed by babaylan and other shamans. Heavy consumption of tubâ and other alcoholic beverages in the Philippines was reported by early Spanish colonizers. Social drinking (inuman or tagayán in Tagalog and Visayan languages) was and is an important aspect of Filipino cultural interfacing.
A peculiar yet nationwide drinking custom is sharing a single drinking vessel. During tagayán, one person (usually the owner of the beverage) becomes the tanggero who fills a cup with a serving of alcohol (a tagay). One of the group then drinks from the cup and passes it back to the tanggero for a refill. The tanggero fills the cup again and passes it to a different person, and so on until all have had a drink. A second method is to drink from the same container at the same time using drinking straws made from hollow reeds or bamboo. Tagayán is usually accompanied by a shared serving of food known as pulutan. The ritual and terminology of tagayán was recorded in the Bocabulario Tagalog (1630) by Fray Miguel Ruiz, and these social drinking practises remain largely unchanged today. Tagayán is also related to the ancient Filipino practice of sandugo (blood compact), as both reinforce camaraderie and social bonds among participants by drinking from the same vessel.
Tubâ was first recorded in European records by Antonio Pigafetta of the Magellan expedition (c. 1521), who called it uraca and mistakenly assumed that it was distilled.
Tubâ could be further distilled using a distinctive type of still into a palm liquor known as lambanóg (palm spirit) and laksoy (nipa). During the Spanish colonial period of the Philippines, lambanog and laksoy were inaccurately called vino de coco ("coconut wine") and vino de nipa ("nipa wine"), respectively, despite them being distilled liquor. From around 1569, lambanog (as vino de coco) was introduced via the Manila galleons to Nueva Galicia (now Colima, Jalisco, and Nayarit) in modern Mexico by Filipino immigrants who established coconut plantations. It quickly became popular in the region, competing with the sales of imported spirits from Spain. This led colonial authorities and the Royal Audience in Spain to ban the production of vino de coco and decree the destruction of coconut plantations. By the mid-1700s, vino de coco production in Mexico had ceased (though non-alcoholic variants of tubâ persisted). The prohibition of vino de coco and the introduced distillation technologies from the Philippines led to the development of mezcal and tequila by the indigenous peoples of Mexico.
Regional variations
Bahal
Bahal is a type of tubâ that is distinctively orange to brown in color because it has added extracts (barok) from the dried bark (marka tungog or tangal) of certain mangrove species (Ceriops tagal, Rhizophora mucronata, or Vateria indica). It is fermented for around a day to a few weeks. It is an intermediate stage in the production of bahalina wines. It originates from the Visayan regions of Visayas and Mindanao.
Kinutil
Kinutil is tubâ mixed with raw egg yolks, tabliya chocolate, milk, and other ingredients. It is widespread in the Visayan regions of Visayas and Mindanao and is also known as kinutir, kutir, or dubado, among other names.
Tuhak
Tuhak is a type of tubâ made from the sap of kaong palm (Arenga pinnata), locally known as kaong or cabonegro. It originates from the Caraga region of Mindanao. It is collected and fermented in the same way as tubâ. However, extracts from the bark of a tree known as lamud may sometimes be added to aid in fermentation and to prevent the souring of the sap. It is also known as hidikup or hidiup in Agusan del Norte and san in Agusan del Sur.
Tunggang
Tunggang is a type of tubâ made by the Manobo, Mandaya, and Mamanwa people from fishtail palm (Caryota spp.) sap. It is not as popular as other varieties of tubâ because it has a relatively more unpleasant smell and taste.
Outside of the Philippines
Mariana Islands
Tubâ production and coconut sap harvesting were introduced to Guam and the Mariana Islands (then part of the Spanish East Indies) by Filipino settlers. Their initial introduction is usually attributed to the Filipino assistants of the Spanish missionary Diego Luis de San Vitores in 1668. Tubâ quickly became a fixture of the culture in the islands, which previously had no native alcoholic drink. The Chamorro people developed two derivatives from tubâ: aguajente (also aguayente or agi, from Spanish aguardiente), a distilled liquor similar to Filipino lambanóg; and almibad, a sweet syrup made from boiled coconut sap used in making candies and rice cakes (potu). Tubâ itself was either consumed fresh (non-alcoholic) or fermented; with the former popular to women and children, and the latter popular to men.
Soon after the acquisition of Guam by the United States from Spain in 1899, aguajente was banned by the American government. Anyone caught making it would get a prison sentence and a fine. The ban remained in place for the next 40 years, restricting tubâ only to the non-alcoholic and mildly alcoholic versions. In 1939, shortly before the outbreak of World War II, taxes were also levied on tubâ-producing coconut palms, further crippling the industry. Today, tubâ is rare in the islands and its production is in decline.
Mexico
Tubâ, along with coconuts (which are not native to the Americas), was introduced to Mexico in the 16th to 17th centuries via the Manila Galleons to Acapulco. It remains popular in Western Mexico where it is known as tuba, particularly in the states of Colima, Jalisco, Michoacán, and Guerrero. Mexican tuba is made in the same way as Filipino tubâ. The traditional sap collectors are known as tuberos (which also means "plumber" in both Mexico and the Philippines). They were also distilled into vino de coco (lambanog), which became so popular that in 1619, Captain Sebastian de Piñeda wrote to King Philip III of Spain complaining of the Filipino "Indio" settlers in Nueva España who were causing significant loss of profits to Iberian alcohol exporters due to tuba. The distinctive Filipino-type stills used by tuba farmers were adopted by the indigenous peoples of Mexico for the distillation of other alcoholic drinks. The most notable of which is mezcal and sotol, the fermented juice of both drinks prior to distillation is still called tuba.
Mexican tuba is also commonly sold as tuba fresca, a non-alcoholic version made from fresh coconut sap. Tuba fresca is traditionally sold by street vendors in large bottle gourds mixed with coconut milk, ice, and sugar. It is usually topped with walnuts and diced fruit.
Torres Strait Islands
In the mid-19th century, Filipino immigrant workers settled in the Torres Strait Islands in Australia to work in the pearling industry as divers and overseers. They settled in sizable communities in Horn Island, Thursday Island, and Hammond Island, numbering at around 500 by 1884. Despite Australian anti-miscegenation laws and the general racism of the Australian government at the time, many Filipinos intermarried with the native Torres Strait Islanders. They also transmitted various Filipino traditions and material culture to the natives, including stories, songs, recipes, various crop plants, and new technologies.
One of these technologies were the methods for producing tubâ. The Islanders, who previously had no tradition of alcohol production or consumption, quickly adopted the tubâ and all its various uses. They consumed coconut sap fresh as a non-alcoholic beverage or as a dip for mangoes; they fermented it into tubâ proper which they also called tuba; they used it as yeast to make bread rise; and they distilled it into liquor which they referred to as "steamed tuba." Even though Australian government prohibitions existed from 1837 to the 1960s banning the sale and consumption of alcohol to Indigenous Australians, it failed to stop the popularity of tuba.
After the introduction of even more restrictive race-based laws in 1901 and the collapse of the pearl and shell market, most Filipinos started leaving Australia and returning to the Philippines. By 1912, almost all of the Filipino population was gone, along with the pearling industry, leaving only the families who intermarried with the locals and their descendants. The tradition of tuba production, however, remained. During World War II, tuba was sold by the Islanders to American servicemen stationed in the Strait who were also familiar with tuba. Tuba is still an important part of Torres Strait Islander culture today.
See also
Mezcal
Bahalina
Lambanog
Basi
Tapuy
Nipa palm vinegar
Kaong palm vinegar
Coconut sugar
References
Fermented drinks
Edible palms
Filipino cuisine
Philippine alcoholic drinks
Guamanian alcoholic drinks
Tree tapping | Tubâ | [
"Biology"
] | 2,038 | [
"Fermented drinks",
"Biotechnology products"
] |
59,468,856 | https://en.wikipedia.org/wiki/Snecked%20masonry | Snecked masonry has a mixture of roughly squared stones of different sizes. It is laid in horizontal courses with rising stones projecting through the courses of smaller stones. Yet smaller fillers called snecks also occur in the courses. The mixture of stone sizes produces a strong bond and an attractive finish. Large amounts of planning for bricklaying process should be considered, as the corners cannot mould perfectly into every size stone. Additional stonecutting and on-the-scene stonecrafting skills may be required.
References
Masonry
Building materials
Stonemasonry
Building stone | Snecked masonry | [
"Physics",
"Engineering"
] | 115 | [
"Masonry",
"Building engineering",
"Construction",
"Stonemasonry",
"Materials",
"Building materials",
"Matter",
"Architecture"
] |
59,469,155 | https://en.wikipedia.org/wiki/Collidinic%20acid | Collidinic acid (pyridine-2,4,6-tricarboxylic acid) is an organic compound that belongs to the heterocycles (more precisely the heteroaromatics). It belongs to the group of pyridinetricarboxylic acids and consists of a pyridine ring which carries three carboxy groups in the 2-, 4- and 6-positions. The name is derived from 2,4,6-collidine (2,4,6-trimethylpyridine).
Preparation
The compound can be obtained from the oxidation of 2,4,6-collidine by potassium permanganate.
Uses
Collidinic acid can be used in the spectrophotometric determination of iron.
References
Pyridines
Tricarboxylic acids
Aromatic acids | Collidinic acid | [
"Chemistry"
] | 181 | [
"Organic compounds",
"Organic compound stubs",
"Organic chemistry stubs"
] |
59,471,623 | https://en.wikipedia.org/wiki/C8H5NO6 | {{DISPLAYTITLE:C8H5NO6}}
The molecular formula C8H5NO6 may refer to:
Berberonic acid
Collidinic acid
3-Nitrophthalic acid
4-Nitrophthalic acid
5-Nitroisophthalic acid
4-(Nitrooxy)carbonyl benzoic acid | C8H5NO6 | [
"Chemistry"
] | 75 | [
"Isomerism",
"Set index articles on molecular formulas"
] |
59,471,688 | https://en.wikipedia.org/wiki/Thermoelectric%20acclimatization | Thermoelectric acclimatization depends on the possibility of a Peltier cell of absorbing heat on one side and rejecting heat on the other side. Consequently, it is possible to use them for heating on one side and cooling on the other and as a temperature control system.
Peltier cell heat pump
A typical Peltier cell based heat pump can be used by coupling the thermoelectric generators with photovoltaic air cooled panels as defined in the PhD thesis of Alexandra Thedeby. Considering the system with an air plant that ensures the possibility of heating on one side and cooling on the other. By changing the configuration it allows both winter and summer acclimatization. These elements are expected to be an effective element for zero-energy buildings, if coupled with solar thermal energy and photovoltaic with particular reference to create radiant heat pumps on the walls of a building.
It must be remarked that this acclimatization method ensures the ideal efficiency during summer cooling if coupled with a photovoltaic generator. The air circulation could be also used for cooling the temperature of PV modules.
The most important engineering requirement is the accurate design of heat sinks to optimize the heat exchange and minimize the fluiddynamic losses.
Thermodynamic parameters
The efficiency can be determined by the following relation:
where is the temperature of the cooling surface and is the temperature of the heating surface.
The key energy phenomena and the reason of defining a specific use of thermoelectric elements (Figure 1) as heat pump resides in the energy fluxes that those elements allow realizing:
Conductive power :
Heat flux on the cold side :
Heat flux on the hot side :
Electric power :
Where the following terms are used: , electric current; α Seebeck coefficient; R electric resistance, S surface area, d cell thickness, and k thermal conductivity.
The efficiencies of the system are:
Cooling efficiency:
Heating efficiency:
COP can be calculated according to Cannistraro.
Final uses
Thermoelectric heat pumps can be easily used for both local acclimatization for removing local discomfort situations. For example, thermoelectric ceilings are today in an advanced research stage with the aim of increasing indoor comfort conditions according to Fanger, such as the ones that may appear in presence of large glassed surfaces, and for small building acclimatization if coupled with solar systems.
Those systems have the key importance in the direction of new zero emissions passive building because of a very high COP value and the following high performances by an accurate exergy optimization of the system.
At industrial level thermoelectric acclimatization appliances are actually under development
References
Heating
Thermodynamics | Thermoelectric acclimatization | [
"Physics",
"Chemistry",
"Mathematics"
] | 554 | [
"Thermodynamics",
"Dynamical systems"
] |
59,472,212 | https://en.wikipedia.org/wiki/NGC%207130 | NGC 7130 (also known as IC 5135) is a spiral galaxy located in the constellation Piscis Austrinus. It is located at a distance of about 220 million light years from Earth, which, given its apparent dimensions, means that NGC 7130 is about 100,000 light years across. It was discovered by John Herschel on September 25, 1834, and discovered independently by Lewis Swift on September 17, 1897. The location of the galaxy given in the New General Catalogue was off by 30 arcminutes in declination from the location of the galaxy.
Characteristics
NGC 7130 is characterised as a peculiar galaxy based on its distorted shape. The galaxy has two faint arms towards the south, while north of the galaxy there is diffuse H-alpha emission. Two knots with H-alpha emission are observed southeast of the galaxy. The galaxy has star streams and trailing tidal arms. It has been suggested that the distorted shape of NGC 7130 is the result of the interaction with another galaxy. In the infrared K-band a bar is visible. The total infrared luminosity of NGC 7130 is (1011.35 ) and it is categorised as a luminous infrared galaxy.
Nucleus
NGC 7130 has a bright nucleus which is characterised as active. The galaxy features optical emission lines typical of a type 2 Seyfert galaxy, with broad lines and strong emission lines from high ionisation elements, like [He II], however the ultraviolet spectrum is more consistent with the emission produced by young, massive O-type stars, suggesting an active starburst in the nucleus. More detailed observations in ultraviolet reveal an asymmetric circumnuclear starburst ring with several knots. The total span of the ring is one arcsecond, which corresponds to 310 pc, in the north-south direction, and 0.7 arcseconds, which corresponds to 220 pc, in east-west direction. Ultraviolet emission is also observed at the inner part of the spiral arms at the leading edge of the bar.
The galaxy emits also X-rays. Based on observations by Chandra X-ray Observatory it was found that the two thirds of the X-ray emission at 0.3–8 keV of the galaxy comes from the circumnuclear starburst activity and the galaxy disk, while the rest was attributed to an active galactic nucleus (AGN) hidden by a Compton-thick column with column density over 1024 cm−2. The percentage attributed to the AGN exceeds 50% at higher energies, over 2 keV. The transition from the emission of the AGN to that of the starburst is smooth, as seen by the different ionisation states of the gas around the nucleus. The extended narrow-line region of NGC 7130 is estimated to have a radius of kpc. There is also an outflowing wind, whose origin however cannot be determined accurately.
In the centre of NGC 7130 lies a supermassive black hole whose mass is estimated to be (107.59 ) based on stellar velocity dispersion.
The star formation rate in the central kiloparsec of NGC 7130 is estimated to be 4.3 per year. The total star formation rate of the galaxy is estimated to be 21 per year.
Supernovae
Two supernovae have been observed in NGC 7130: SN 2010bt (type IIn, mag 15.9), and SN 2017hgz (type Ia, mag 15.1).
Nearby galaxies
NGC 7130 belongs in a galaxy group known as LGG 445. Other members of the galaxy group include NGC 7057, IC 5105, NGC 7087, NGC 7060, NGC 7072, NGC 7075, NGC 7110, IC 5128, and IC 5139. Near NGC 7130 lie also the distorted NGC 7135, 18 arcminutes to the east, and IC 5131, 12 arcminutes to the west. It has been suggested that the distortion of NGC 7130 was caused by an interaction with one of these two galaxies, however, they have nearly half the redshift.
See also
NGC 7679 - A similar starburst and active galaxy
References
External links
NGC 7130 on SIMBAD
Spiral galaxies
Peculiar galaxies
Seyfert galaxies
Luminous infrared galaxies
Piscis Austrinus
7130
IC objects
67387
Discoveries by John Herschel
Astronomical objects discovered in 1834
Galaxies discovered in 1834
403-G032
-06-47-015 | NGC 7130 | [
"Astronomy"
] | 925 | [
"Piscis Austrinus",
"Constellations"
] |
59,472,484 | https://en.wikipedia.org/wiki/Charlotte%20Fitch%20Roberts | Charlotte Fitch Roberts (February 13, 1859 – December 5, 1917) was an American chemist best known for her work on stereochemistry.
Life
Roberts was born on February 13, 1859, in New York City to Horace Roberts and Mary Roberts (née Hart).
Education and career
Roberts attended Wellesley College in 1880. Wellesley made her a graduate assistant in 1881, an instructor in 1882, and an associate professor in 1886. In 1885 she spent a year at Cambridge University working with Sir James Dewar, a chemist and physicist. In 1896 she published The Development and Present Aspects of Stereochemistry. She obtained a PhD from Yale in 1894 and a post at the University of Berlin from 1899 to 1900. She was made a professor and the head of the chemistry department from 1896 to 1917 at Wellesley College.
Awards and professional bodies
Roberts was made a fellow of the American Association for the Advancement of Science, and a chemistry professorship at Wellesley now bears her name.
References
External links
1859 births
1917 deaths
Scientists from New York City
American women chemists
Stereochemists
20th-century American chemists
19th-century American chemists
Wellesley College alumni
Yale University alumni
Wellesley College faculty
Fellows of the American Association for the Advancement of Science | Charlotte Fitch Roberts | [
"Chemistry"
] | 242 | [
"Stereochemistry",
"Stereochemists"
] |
59,473,839 | https://en.wikipedia.org/wiki/Potassium%20tellurite | Potassium tellurite, K2TeO3, is an inorganic potassium-tellurium compound. It has been used as a selective growth medium in microbiology.
References
Tellurites
Potassium compounds | Potassium tellurite | [
"Chemistry"
] | 42 | [
"Inorganic compounds",
"Inorganic compound stubs"
] |
54,487,875 | https://en.wikipedia.org/wiki/1-Hexadecene | 1-Hexadecene, also known as 1-cetene, is a long-chain hydrocarbon and an alkene with the molecular formula CH2=CH(CH2)13CH3. It is one of many isomers of hexadecene. Classified as an alpha-olefin, 1-hexadecene is a colorless liquid.
Uses
1-Hexadecene is used as a surfactant in lubricating fluid, a drilling fluid in the boring and drilling industry, and in paper sizing. It
is used to functionalize hydrogen-terminated silicon surfaces by hydrosilation.
However, the high reactivity of 1-hexadecene means that exposure to air could cause oxidation of its surface layer, forming unwanted impurities. It is stored with the use of tank blanketing, and handled in a dry, inert atmosphere.
References
Hexadecene1 | 1-Hexadecene | [
"Chemistry"
] | 189 | [
"Organic compounds",
"Alkenes"
] |
54,489,716 | https://en.wikipedia.org/wiki/Carlos%20Jaschek | Carlos Jaschek (March 2, 1926 – April 12, 1999) was a German-born Argentine astrophysicist who spent time in the United States, lived in Switzerland, settled in France, became a French citizen and worked to make astronomical data accessible to all nations. As the second Director of a new center in Strasbourg, France, designed to be a computerized repository for data about the stars, he was part of its early team who were determined, clearsighted decision-makers when its resources were limited.
Jaschek began in astronomy at La Plata, in South America, later directing its Astrophysics Department. He travelled and conducted research at many observatories along with his wife, the stellar astronomer and spectroscopist Mercedes Jaschek, with whom he spent a lifetime collaborating in research. They lived in Argentina from 1937 to 1973. With his wife and his other colleagues, Jaschek was involved with both stellar spectroscopy and photometry, the newly-accessible infrared(IR) and ultraviolet (UV) as well as visible light, astronomical statistics and guidelines for designating stars, and with the chemically peculiar stars
In addition to his research discoveries, he co-created atlases and catalogues and published them. He was President of the International Astronomical Union's Commission 45 Stellar Classification. and was an early proponent of creating astronomical databases.
He founded an organization to encourage research on the impact of astronomy on society, the SEAC. The Jaschek's retired in 1993 and moved to Spain, continuing to be active in scientific endeavors. Mercedes Jaschek died in 1995, and Carlos Jaschek in 1999.
Career
Jaschek was born on March 2, 1926, in Brieg, Germany, (now Brzeg, Poland). His family moved to Argentina in South America when he was 11. In 1947, he was hired at La Plata Observatory. His wife, Mercedes Isabel Corvalán de Jaschek, was an Argentine stellar spectroscopist, who also began at the National University of La Plata in 1947. The pair collaborated throughout their lives. Carlos Jaschek received his Ph.D. in astronomy in 1952.
After a year in the United States, he became professor in astrophysics at La Plata University and the director of the Astrophysical Department in 1957. Jaschek's initial research at La Plata involved observing minor planets. He began programs in stellar spectroscopy and worked to develop equipment particularly in photoelectric photometry. He was also involved with Argentina's fledgling radio astronomy and space program. In 1972, he organized the first astrophysics conference in Latin America.
From 1957 to 1973, Jaschek made contacts with other spectroscopists, creating lifelong collaborations with astronomers in other nations when he travelled to observatories and astronomy departments including Yerkes Observatory, Perkins Observatory, Ohio State University, the University of Michigan and elsewhere. He was Invited Professor at Perkins Observatory in 1964 and 1967, and also at the University of Chicago (Yerkes) as a research associate in 1967. He was invited professor at the Argentine National Observatory at Córdoba in 1968. In 1970, he was invited professor at Cordoba, Ohio State University, and at Geneva University. Mercedes Jaschek also conducted research at Cordoba, Perkins, Yerkes, Michigan and Geneva.
From 1970 to 1973, Jaschek was the vice president of the International Astronomical Union's (IAU) Commission 45 Stellar Classification, and he became president of that commission in 1973. He moved from La Plata to Europe in 1973 due to the political situation. There was political instability at that time in Argentina.
In 1973, Jaschek was again at Geneva University as invited professor. He was then hired as an associate professor at Strasbourg University. He was at Strasbourg from 1974 to 1993, and he became a French citizen, as did his wife. He later became full professor, and supervised many students.
Jaschek encouraged the development of automated methods for stellar classification classifying stars. He also encouraged the development of astronomical data bases. He was "a force behind the development of the C.D.S," the Center de Données Stellaires (Center of Stellar Data). In 1968, Jaschek had described the problem of the increasing volume of astronomical data without adequate means of collecting and distributing it:
After a year at Geneva, Jaschek became Director of the Center de Données Stellaires(CDS) in Strasbourg. The CDS, begun in 1972, was an innovative but challenging project to create a central repository for astronomical data, an idea "even questioned by many French astronomers". In 1974, its first director, Jean Jung, changed careers. Carlos Jaschek officially began as Director in 1975, and Mercedes Jaschek strengthened the Center's limited scientific staff. In 1977, Jaschek summarized the strengths and weakness of the world's astronomical data bases and noted that, with the exception of peculiar stars, considerable advances were being made. Jaschek noted:
Jaschek directed the Center of Stellar Data (CDS) from 1975 to 1990, As Director, he was "instrumental in organizing world-wide access to astronomical data with special sensitivity to third-world countries. As the second director of CDS, Jaschek's 15-year term was said to have brought "spectacular progress for CDS" by increasing its international reputation as it was established as the leading astronomical data base. When it expanded its focus from stars to include other non-solar system astronomical objects, it changed its name from Center de Données Stellaires to the Centre de données astronomiques de Strasbourg (The Center of astronomical Data of Strasbourg).
As Director, Jaschek was concerned with improving astronomical naming conventions. In 1979 at an IAU meeting in Canada, over 100 astronomers from 15 Commissions met regarding the designation of objects, and before William P. Bidelman gave the report on their suggested reforms, Carlos Jaschek began to introduce the need for them by saying:
In 1986, he listed the 10 different factors for which a star may be named, noting that the variety was for historical reasons and "It is certainly not very rational to have 10 different practices for the same operation", before suggesting some guidelines.
Jaschek was also interested in the Set of Identifications, Measurements and Bibliography for Astronomical Data (SIMBAD). SIMBAD became operational in 1990. In addition to working to make the CDS the world's largest astronomical database, Jaschek helped with the creation of astronomical data centers in China, Japan, India, Argentina and the U.S.S.R.
Jaschek worked in spectroscopy, photometry, and classification of stars and in statistical astronomy. Carlos and Mercedes Jaschek worked on stars, making spectral classification catalogs and atlases of spectral atlases in visible, ultraviolet (UV) and infrared (IR) wavelengths. They worked on the first classification schemes for the ultraviolet spectrum They collaborated with Yvette Andrillat on stars in the near-infrared, and Carlos Jaschek had a long-term collaboration with the Marcel Golay group in Switzerland to make comparisons between photometry and spectroscopy.
The Jascheks collaborated on Be, Ae, shell, Ap, and other peculiar stars. They produced a catalogue and bibliography of 2,000 Be stars for the period from 1950 to 1970 based on Mercedes Jaschek's survey of the Southern Celestial Hemisphere.
They were the first to introduce the gallium stars subgroup and to discover the ApSi4200 stars. They were the first to find the rare CNO stars which are O- or B- B-type stars where some of the elements C, N and O show spectral lines that are weaker or stronger than would be expected. They also identified the presence of rare-earth elements in stars of Mn and SrCrEu groups.
Carlos Jaschek helped create the Catalog of Bright Stars (fourth edition). Together the Jascheks wrote The Classification of Stars, which had 20 editions published, The Behavior of Chemical Elements in Stars (1995), and Spectroscopic Atlas for the Southern Sky Stars and other books. Their reference works were incorporated into the Strasbourg Centre of Stellar Data (CDS).
Jaschek also wrote Data in Astronomy in which he noted he became involved with data at La Plata in the early 1960s, when he was compiling a catalogue with a student for their own use and the student suggested publishing it. He authored or co-authored ~250 refereed publications and over 15 books and was noted for "precise observation and careful classification of peculiar stars" using the MK classification system.
Jaschek was Invited Speaker at ~15 international meetings. He helped organize 14 scientific meetings, and frequently edited or co-edited the proceedings. In 1992, Jaschek founded the Société Européenne pour l' Astronomie dans la culture (European Society for Astronomy in Culture), a cultural astronomy organization which holds yearly conferences and is open to all nations.
Retirement
In 1993, the Jascheks retired from Strasbourg Observatory. Due to poor health, they moved to Salamanca (Spain) to live with their daughter's family, and continued their scientific activities from their new location. The couple has been described as "inseparable in their life and in their work". Mercedes Jaschek died on November 21, 1995, and he was deeply impacted by the loss.
Jaschek continued making public presentations, and in 1998 he published a book on ethno-astronomy. He was remembered as someone who loved his family, astronomy and its impact on culture, teaching and history books, and was regarded as kind, optimistic, upright, and helpful.
Carlos Jaschek died April 12, 1999, in Salamanca, Spain.
Memberships and honors
The Carlos Jaschek Award was created in his honor in 2006 by the Société Européenne pour l' Astronomie dans la culture (European Society for Astronomy in Culture).
The minor planet (2964) Jaschek was named after him. It was discovered July 16, 1974, at the Carlos U. Cesco Observatory at El Leoncito.
Received the 1955 John Simon Guggenheim Memorial Foundation fellowship. "Carlos Oton Rüdiger Jaschek". Astronomy and Astrophysics; Latin America & Caribbean competition.
Member of the National Center for Scientific Research in France
Member of the National Academy of Sciences of Argentina.
Member of the Royal Argentine Astronomical Society
Member of the Astronomische Gesellschaft, the German Astronomical Society.
Member of the International Astronomical Union (IAU) Organizing Committee of Commission 33 Structure & Dynamics of the Galactic System from 1964 to 1967. Member of the Organizing Committee of Commission 45 Stellar Classification from 1967 to 1970, Jaschek became Vice-President from 1970 to 1973, was President from 1973 to 1976, and was on the Organizing Committee from 1976 to 1979. He was on the Organizing Committee of Commission 29 Stellar Spectra from 1973 to 1985, and on the Organizing Committee of Commission 5 Documentation and Astronomical Data from 1982 to 1991.
Select bibliography
Hoffleit, D.; Jaschek, C. (1982). The Bright Star Catalogue. Fourth revised edition. (Containing data compiled through 1979) Yale University Observatory, New Haven, CT, USA.
Cowley, Anne, Cowley, Charles, Jaschek, Mercedes & Jaschek, Carlos. "A study of the bright A stars. I. A catalogue of spectral classifications". Astronomical Journal, 74(3):375 – 406. April, 1969.
Jaschek, Carlos; Jaschek, Mercedes. (1987). The Classification of stars. Cambridge University Press. 1987. .
Jaschek, M.; Jaschek, C.; Hubert-Delplace, A.-M.; Hubert, H. "A classification of Be stars". Astronomy and Astrophysics Supplement Series, 42:103–114. October, 1980.
Jaschek, Carlos; Conde, Horacio; de Sierra, Amelia C. "Catalogue of stellar spectra classified in the Morgan-Keenan system". Serie Astronomica, La Plata: Observatorio Astronomico de la Universidad de la Plata. 1964.
See also
Peculiar stars
Stellar classification
Notes
References
Further reading
The Cambridge Encyclopedia of Stars by James B. Kaler (2006). Cambridge University Press. .
External links
European Society for Astronomy in Culture (SEAC: Societe Europeenne pour I'Astronomie dans la Culture).
Strasbourg astronomical Data Center.
SIMBAD Astronomial Database.
VizieR Service.
Aladin Sky Atlas.
1926 births
1999 deaths
German emigrants to Argentina
Spectroscopists
20th-century Argentine astronomers
National University of La Plata alumni
Academic staff of the National University of La Plata
Academic staff of the University of Strasbourg
Naturalized citizens of France
20th-century French astronomers
French astrophysicists
Centre de données astronomiques de Strasbourg | Carlos Jaschek | [
"Physics",
"Chemistry",
"Astronomy"
] | 2,624 | [
"Physical chemists",
"Spectrum (physical sciences)",
"Analytical chemists",
"Spectroscopists",
"Centre de données astronomiques de Strasbourg",
"Spectroscopy",
"Astronomy data and publications"
] |
54,491,519 | https://en.wikipedia.org/wiki/NGC%207061 | NGC 7061 is an elliptical galaxy located about 400 million light-years away in the constellation of Indus. NGC 7061 was discovered by astronomer John Herschel on September 30, 1834.
See also
NGC 7012
List of NGC objects (7001–7840)
References
External links
Elliptical galaxies
Indus (constellation)
7061
66785
Astronomical objects discovered in 1834 | NGC 7061 | [
"Astronomy"
] | 77 | [
"Indus (constellation)",
"Constellations"
] |
54,491,997 | https://en.wikipedia.org/wiki/Karl%20Arnold%20%28chemist%29 | Karl Arnold, variously Carl Johann Moritz Arnold or Johann Karl Moritz Arnold (12 March 1853 – 24 June 1929), was a German chemist and mountaineer. He served as Director and briefly as Vice-Chancellor of the Institute of Chemistry at the University of Veterinary Medicine Hanover. His published works on organic chemistry were of importance to veterinarians, medical students and pharmacists. He was also an accomplished alpinist and chairman of the Hanover section of the German-Austrian Alpine Association.
Early life
Karl Arnold was the son of chemist Georg Friedrich Arnold of the village of Uffenheim. From 1851 to 1859 Georg Friedrich Arnold operated a pharmacy in the lower floor of the town hall.
The family then moved to Ansbach, where Georg Friedrich Arnold became the Bavarian court pharmacist.
Education
After attending the local gymnasium Karl Arnold began training as a pharmacist with his Father, also working as an assistant apothecary in pharmacies in Zofingen, Hamburg, Frankfurt am Main and Magdeburg.
In 1875 he began formal studies in pharmacy at the University of Munich, receiving his license as a pharmacist in 1876.
Arnold worked with Max Joseph von Pettenkofer, professor of hygiene at Munich.
During his time in Munich, he became a member of an academic singing association, the Akademische Gesangverein (AGV) München in the Sondershäuser Verband.
Arnold went on to study chemistry and physics at the University of Tübingen, where he worked with Julius Lothar Meyer. Meyer proposed models for the periodic table of elements in 1860 and 1868, and Arnold himself proposed a model for the periodic table in 1885.
In 1877 Arnold passed the state teaching examinations for natural science. He completed his doctoral thesis with Robert Wilhelm Bunsen at the University of Heidelberg, studying inorganic and physical chemistry. Arnold received the degree of Doctor of Philosophy in 1878, at the age of 25.
Karl Arnold worked as a pharmacist to fulfill his military service. He was an assistant in Würzburg and a lecturer in Gerstungen.
Royal Veterinary School
On 1 May 1880 Arnold began to work at the Königliche Tierarzneischule (Royal Veterinary School) in Hanover (now the University of Veterinary Medicine Hanover). Initially he was a lecturer, demonstrator and tutor in chemistry and physics, earning "1500 M. Remuneration, freier Wohnung, Licht und Heizung in der Anstalt" ("1500 M. Remuneration, free apartment, light and heating in the institution").
When chairman Karl Begemann fell ill in 1883, Arnold took over his chemistry courses. After Begemann died in 1885, Arnold was formally appointed as lecturer in chemistry, pharmacy and pharmacognosy. He became head of the university pharmacy. As of 1889, Arnold became director of the Institute of Chemistry and the sole chemistry lecturer. In 1890 he was appointed to the rank of professor.
Following the mandate given to Begemann to expand and modernize the chemistry department, Arnold developed an expansion plan including chemical labs and an auditorium. As of 1899, this plan was put into effect, locating the new buildings on the Bischofsholer Damm.
Karl Arnold remained director of the Chemistry Institute from 1889 until 1921.
In 1913, the university created the post of rector. Karl Arnold was the first person to be elected to the Vice-Chancellor of the School of Veterinary Medicine, on 7 May 1913, but declined the post. It was eventually accepted by Bernhard Malkmus (1913 - 1915) who held the rectorship from 1913 to 1915. Malkmus was called up for military service in 1915, and Arnold replaced him as Vice-Chancellor from 30 May 1915 to 1 August 1915.
Arnold died on 24 June 1929.
A street, Karl-Arnold-Platz, is named in his honor.
Research
In organic chemistry, Arnold studied the determination of chlorides, urea, uric acid, phosphates, alkaloids and sugar under physiological conditions. Many of these substances were part of the composition of urine, and could be useful in assessing both normal body function and disease.
He also studied disinfectants including hydrogen peroxide, formalin, lysol, ozone, and creole soaps. He developed methods to detect and characterize their use in medications. He also studied the hygiene of milk and food ingredients and tested air quality in stables.
He published extensively on chemical analysis, veterinary medicine, and medicine.
His Repetitorium der Chemie ("Chemistry Revision Course") was a standard work for veterinarians, medical students and pharmacists. Reprinted sixteen times, its last edition appeared in 1923. Anleitung zur qualitativen, chemischen Analyse anorganischer und organischer Körper sowie zur toxikologisch-chemischen und medizinisch-chemischen Analyse ("Instruction Manual on Qualitative, Chemical Analysis of Inorganic and Organic Bodies as well as on Toxicological-Chemical and Medical-Chemical Analysis") was also frequently reprinted, as was Pharmakognosie, pharmazeutisch-chemische Präparate und Rezeptierkunde ("Pharmacognosis, Pharmaceutical-Chemical Substances and the Science of Prescribing"). Arnold also published a three-volume work, Tierärztliche Arzneibuch für Studierende und praktische Tierärzte ("Veterinary Medicinal Book for Students and Practising Veterinarians" with professor of physiology Josef Tereg.
Arnold's published works also included a design for the periodic table.
Mountaineering
In 1869 16-year-old Karl Arnold climbed the Alps for the first time.
He was a member of the German-Austrian Alpine Association (Deutscher und Österreichischer Alpenverein) for almost 45 years, and chairman of the Hanover section.
After making an ascent of the Ankogel in 1885, he encouraged development of the town of Mallnitz in Carinthia, now part of High Tauern National Park as a locale for mountaineers.
In 1886 the main committee of the Alpine Association gave the Hanover section responsibility for the Ankogel area. The hill to the left of the original Hanover House was renamed Arnoldhöhe in Carl Arnold's honor in 1888. Arnold and the Hanover section arranged for the building of the original Hanover House above Mallnitz on the Etschlsattel, inaugurated in 1911 to meet the needs of visitors using the recently built Tauern Railway. (In 2014 a newer building of the same name was built nearby, replacing the original which had burnt.)
Arnold's ashes were buried in an urn in a small mausoleum that Arnold had built on the Arnoldshöhe near what was then Hanover house.
References
1853 births
1929 deaths
20th-century German chemists
German mountain climbers
People involved with the periodic table
19th-century German chemists | Karl Arnold (chemist) | [
"Chemistry"
] | 1,429 | [
"Periodic table",
"People involved with the periodic table"
] |
54,492,195 | https://en.wikipedia.org/wiki/NGC%207064 | NGC 7064 is a nearby edge-on barred spiral galaxy located about 35 million light-years away in the constellation of Indus. NGC 7064 has an estimated diameter of 51,000 light-years. NGC 7064 was discovered by astronomer John Herschel on July 8, 1834.
See also
NGC 4013
List of NGC objects (7001–7840)
References
External links
Barred spiral galaxies
Indus (constellation)
7064
66836
Astronomical objects discovered in 1834 | NGC 7064 | [
"Astronomy"
] | 95 | [
"Indus (constellation)",
"Constellations"
] |
54,492,223 | https://en.wikipedia.org/wiki/Radioactive%20nanoparticle | A radioactive nanoparticle is a nanoparticle that contains radioactive materials. Radioactive nanoparticles have applications in medical diagnostics, medical imaging, toxicokinetics, and environmental health, and are being investigated for applications in nuclear nanomedicine. Radioactive nanoparticles present special challenges in operational health physics and internal dosimetry that are not present for other substances, although existing radiation protection measures and hazard controls for nanoparticles generally apply.
Types and applications
Engineered
Engineered radioactive nanoparticles are used in medical imaging techniques such as positron emission tomography and single-photon emission computed tomography, and an aerosol of carbon nanoparticles containing technetium-99m are used in a commercially available procedure for ventilation/perfusion scintigraphy of the lungs. Engineered radioactive nanoparticles are also used as a radiolabel to detect the presence of the nanoparticles themselves in environmental health and toxicokinetics studies.
Engineered radioactive nanoparticles are being investigated for therapeutic use combining nuclear medicine with nanomedicine, especially for cancer. Neutron capture therapy is one such potential application. In addition, nanoparticles can help to sequester the toxic daughter nuclides of alpha emitters when used in radiotherapy.
Nuclear imaging is non-invasive and has high sensitivity, and nanoparticles are useful as a platform for combining multiple copies of targeting vectors and effectors in order to selectively deliver radioisotopes to a specific region of interest. Other benefits of nanoparticles for diagnostic and therapeutic use include increased blood and tumor retention time, as well as the possibility of using their unique physical and chemical properties in treatment. However, the nanoparticles must be engineered to avoid being recognized by the mononuclear phagocyte system and transported to the liver or spleen, often through manipulating their surface functionalization.
Targeting techniques include functionalizing radioactive nanoparticles with antibodies to target them to a specific tissue, and using magnetic nanoparticles that are attracted to a magnet placed over the tumor site. Technetium-99m, indium-111, and iodine-131 are common radioisotopes used for these purposes, with many others used as well. Radioactive nanoparticles can be produced by either synthesizing the nanoparticles directly from the radioactive materials, or by irradiating non-radioactive particles with neutrons or accelerated ions, sometimes in situ.
Natural and incidental
As with all nanoparticles, radioactive nanoparticles can also be naturally occurring or incidentally produced as a byproduct of industrial processes. The main source of naturally occurring nanomaterials containing radionuclides is the decay of radon gas, whose immediate decay products are non-gaseous elements that precipitate into nanoscale particles along with atmospheric dust and vapors. Minor natural sources include primordial radionuclides present in the nanoscale portion of volcanic ash, and primordial and cosmogenic nuclides taken up by plants which are later burned. Radioactive nanoparticles may be incidentally produced by procedures in the nuclear industry such as nuclear reprocessing and the cutting of contaminated objects.
Health and safety
Radioactive nanoparticles combine the hazards of radioactive materials with the hazards of nanomaterials. Inhalation exposure is the most common route of exposure to airborne particles in the workplace. Animal studies on some classes of nanoparticles indicate pulmonary effects including inflammation, granulomas, and pulmonary fibrosis, which were of similar or greater potency when compared with other known fibrogenic materials such as silica, asbestos, and ultrafine carbon black. Some studies in cells or animals have shown genotoxic or carcinogenic effects, or systemic cardiovascular effects from pulmonary exposure. The hazards of ionizing radiation depend on whether the exposure is acute or chronic, and includes effects like radiation-induced cancer and teratogenesis. In some cases, the inherent physicochemical toxicity of the nanoparticle itself may lead to lower exposure limits than those associated with the radioactivity alone, which is not the case with most radioactive materials.
Radioactive nanoparticles present special challenges in operational health physics and internal dosimetry that are not present for other substances, as the nanoparticles' toxicokinetics depend on their physical and chemical properties including size, shape, and surface chemistry. For example, inhaled nanoparticles will deposit in different locations in the lungs, and will be metabolized and transported through the body differently, than vapors or larger particles. There may also be hazards from associated processes such as strong magnetic fields and cryogens used in imaging equipment, and handling of lab animals in experimental studies. Effective risk assessment and communication is important, as both nanotechnology and radiation have unique considerations with public perception.
Hazard controls
In general, most elements of a standard radiation protection program are applicable to radioactive nanomaterials, and many hazard controls for nanomaterials will be effective with the radioactive versions. The hierarchy of hazard controls encompasses a succession of five categories of control methods to reduce the risk of illness or injury. The two most effective are elimination and substitution, for example reducing dust exposure by eliminating a sonication process or substituting a nanomaterial slurry or suspension in a liquid solvent instead of a dry powder. Substitutions should consider both the radioactivity and physicochemical hazards of all the options, and also take into account that radioactive nanomaterials are easier to detect than non-radioactive substances.
Engineering controls should be the primary form of protection, including local exhaust systems such as fume hoods, gloveboxes, biosafety cabinets, and vented balance enclosures; radiation shielding; and access control systems. The need for negative room pressure to prevent contamination of outside areas can conflict with the customary use of positive pressure when pharmaceuticals are being handled, although this can be overcome through use of a cascade pressure system, or by handling nanomaterials in enclosures.
Administrative controls include procedures to limit radiation doses, and contamination control procedures including encouraging good work practices and monitoring for contamination. Personal protective equipment is the least effective and should be used in conjunction with other hazard controls. In general, personal protective equipment intended for radioactive materials should be effective with radioactive nanomaterials, including impervious laboratory coats, goggles, safety gloves, and in some cases respirators, although the greater potential penetration through clothing and mobility in air of nanoparticles should be taken into account.
See also
Health and safety hazards of nanomaterials
Radiation protection
References
Nanomedicine
Nanoparticles by physical property
Nuclear medicine | Radioactive nanoparticle | [
"Materials_science"
] | 1,379 | [
"Nanomedicine",
"Nanotechnology"
] |
54,492,474 | https://en.wikipedia.org/wiki/Newton%27s%20minimal%20resistance%20problem | Newton's minimal resistance problem is a problem of finding a solid of revolution which experiences a minimum resistance when it moves through a homogeneous fluid with constant velocity in the direction of the axis of revolution, named after Isaac Newton, who studied the problem in 1685 and published it in 1687 in his Principia Mathematica. This is the first example of a problem solved in what is now called the calculus of variations, appearing a decade before the brachistochrone problem. Newton published the solution in Principia Mathematica without his derivation, and David Gregory was the first person who approached Newton and persuaded him to write an analysis for him. Then the derivation was shared with his students and peers by Gregory.
According to I. Bernard Cohen, in his Guide to Newton’s Principia, "The key to Newton’s reasoning was found in the 1880s, when the earl of Portsmouth gave his family’s vast collection of Newton’s scientific and mathematical papers to Cambridge University. Among Newton’s manuscripts they found the draft text of a letter, … in which Newton elaborated his mathematical argument. [This] was never fully understood, however, until the publication of the major manuscript documents by D. T. Whiteside [1974], whose analytical and historical commentary has enabled students of Newton not only to follow fully Newton’s path to discovery and proof, but also Newton’s later (1694) recomputation of the surface of least resistance".
Even though Newton's model for the fluid was wrong as per our current understanding, the fluid he had considered finds its application in hypersonic flow theory as a limiting case.
Definition
In Proposition 34 of Book 2 of the Principia, Newton wrote: "If in a rare medium, consisting of equal particles freely disposed at equal distances from each other, a globe and a cylinder described on equal diameter move with equal velocities in the direction of the axis of the cylinder, the resistance of the globe will be but half as great as that of the cylinder."
Following this proposition is a scholium containing the famous condition that the curve which, when rotated about its axis, generates the solid that experiences less resistance than any other solid having a fixed length, and width.
In modern form, Newton's problem is to minimize the following integral:
where represents the curve which generates a solid when it is rotated about the x axis, and
I is the reduction in resistance caused by the particles impinging upon the sloping surface DNG, formed by rotating the curve, instead of perpendicularly upon the horizontal projection of DNG on the rear disc DA from the direction of motion, in Fig. 1 below. Note that the front of the solid is the disc BG, the triangles GBC and GBR are not part of it, but are used below by Newton to express the minimum condition.
This integral is related to the total resistance experienced by the body by the following relation:
The problem is to find the curve that generates the solid that experiences less resistance than any other solid having a fixed axial length L and a fixed width H.
Since the solid must taper in the direction of motion, H is the radius of the disc forming the rear surface of the curve rotated about the x axis. The units are chosen so that the constant of proportionality is unity. Also, note that and the integral, which is evaluated between x = 0 and x = L is negative. Let y = h when x = L.
When the curve is the horizontal line DK, so the solid is a cylinder, the integral is zero, and the resistance of the cylinder is which explains the constant term.
Condition for a minimum resistance solid
The simplest way to apply the Euler–Lagrange equation to this problem is to rewrite the resistance as
where , and the integral, which is evaluated between y = H and y = h < H, is negative.
Substituting the integrand into the Euler–Lagrange equation
and it follows that is constant, and this can be written as
where , and is a constant.
Although the curves that satisfy the minimum condition cannot be described by a simple function y = f(x), they may be plotted using p as a parameter, to obtain the corresponding coordinates (x, y) of the curves. The equation of x as a function of p is obtained from the minimum condition (1), and an equivalent of it was first found by Newton.
Differentiating:
and integrating:
where is a constant.
Since when , and when , the constants can be determined in terms of H, h and L. Because y from equation (1) can never be zero or negative, the front surface of any solid satisfying the minimum condition must be a disc (GB in Fig. 2 above).
As this was the first example of this type of problem, Newton had to invent a completely new method of solution. Also, he went much deeper in his analysis of the problem than simply finding the condition (1).
Solid experiencing least resistance
While a solid of least resistance must satisfy (1), the converse is not true. Fig. 2 shows the family of curves that satisfy it for different values of . As increases the radius, Bg = h, of the disc at x = L decreases and the curve becomes steeper.
Directly before the minimum resistance problem, Newton stated that if on any elliptical or oval figure rotated about its axis, p becomes greater than unity, one with less resistance can be found. This is achieved by replacing the part of the solid that has p > 1 with the frustum of a cone whose vertex angle is a right angle, as shown in Fig. 2 for curve . This has less resistance than . Newton does not prove this, but adds that it might have applications in shipbuilding. Whiteside supplies a proof and contends that Newton would have used the same reasoning.
In Fig. 2, since the solid generated from the curve Dng satisfies the minimum condition and has p < 1 at g, it experiences less resistance than that from any other curve with the same end point g. However, for the curve DνΓ, with p > 1 at end point Γ, this is not the case for although the curve satisfies the minimum condition, the resistance experienced by φγ and γΓ together is less than that by φΓ.
Newton concluded that of all solids that satisfy the minimum resistance condition, the one experiencing the least resistance, DNG in Fig. 2, is the one that has p = 1 at G. This is shown schematically in Fig. 3 where the overall resistance of the solid varies against the radius of the front surface disc, the minimum occurring when h = BG, corresponding to p = 1 at G.
In the Principia, in Fig. 1 the condition for the minimum resistance solid is translated into a geometric form as follows: draw GR parallel to the tangent at N, so that , and equation (1) becomes:
At G, , , and , so which appears in the Principia in the form:
Newton's derivation of the minimum resistance condition
Although this appears fairly simple, it has several subtleties that have caused much confusion.
In Fig 4, assume DNSG is the curve that when rotated about AB generates the solid whose resistance is less than any other such solid with the same heights, AD = H, BG = h and length, AB = L.
Fig. 5. shows the infinitesimal region of the curve about N and I in more detail. Although NI, Nj and NJ are really curved, they can be approximated by straight lines provided NH is sufficiently small.
Let HM = y, AM = x, NH = u, and HI = w = dx. Let the tangent at each point on the curve, . The reduction of the resistance of the sloping ring NI compared to the vertical ring NH rotated about AB is (2)
Let the minimum resistance solid be replaced by an identical one, except that the arc between points I and K is shifted by a small distance to the right , or to the left , as shown in more detail in Fig. 5. In either case, HI becomes .
The resistance of the arcs of the curve DN and SG are unchanged. Also, the resistance of the arc IK is not changed by being shifted, since the slope remains the same along its length. The only change to the overall resistance of DNSG is due to the change to the gradient of arcs NI and KS. The 2 displacements have to be equal for the slope of the arc IK to be unaffected, and the new curve to end at G.
The new resistance due to particles impinging upon NJ or Nj, rather that NI is:
+ w.(terms in ascending powers of starting with the 2nd).
The result is a change of resistance of: + higher order terms, the resistance being reduced if o > 0 (NJ less resisted than NI).
This is the original 1685 derivation where he obtains the above result using the series expansion in powers of o. In his 1694 revisit he differentiates (2) with respect to w. He sent details of his later approach to David Gregory, and these are included as an appendix in Motte’s translation of the Principia.
Similarly, the change in resistance due to particles impinging upon SL or Sl rather that SK is: + higher order terms.
The overall change in the resistance of the complete solid, + w.(terms in ascending powers of starting with the 2nd).
Fig 6 represents the total resistance of DNJLSG, or DNjlSG as a function of o. Since the original curve DNIKSG has the least resistance, any change o of whatever sign, must result in an increase in the resistance. This is only possible if the coefficient of o in the expansion of is zero, so:
(2)
If this was not the case, it would be possible to choose a value of o with a sign that produced a curve DNJLSG, or DNjlSG with less resistance than the original curve, contrary to the initial assumption. The approximation of taking straight lines for the finite arcs, NI and KS becomes exact in the limit as HN and OS approach zero. Also, NM and HM can be taken as equal, as can OT and ST.
However, N and S on the original curve are arbitrary points, so for any 2 points anywhere on the curve the above equality must apply. This is only possible if in the limit of any infinitesimal arc HI, anywhere on the curve, the expression,
is a constant. (3)
This has to be the case since, if was to vary along the curve, it would be possible to find 2 infinitesimal arcs NI and KS such that (2) was false, and the coefficient of o in the expansion of would be non-zero. Then a solid with less resistance could be produced by choosing a suitable value of o.
This is the reason for the constant term in the minimum condition in (3). As noted above, Newton went further, and claimed that the resistance of the solid is less than that of any other with the same length and width, when the slope at G is equal to unity. Therefore, in this case, the constant in (3) is equal to one quarter of the radius of the front disc of the solid, .
References
Minimal surfaces
Isaac Newton
Calculus of variations
Mathematical problems | Newton's minimal resistance problem | [
"Chemistry",
"Mathematics"
] | 2,342 | [
"Foams",
"Mathematical problems",
"Minimal surfaces"
] |
54,493,344 | https://en.wikipedia.org/wiki/NGC%207065 | NGC 7065 Is a barred spiral galaxy located about 320 million light-years away in the constellation of Aquarius. NGC 7065 is part of a pair of galaxies that contains the galaxy NGC 7065A. NGC 7065 was discovered by astronomer Albert Marth on August 3, 1864.
See also
NGC 7042
List of NGC objects (7001–7840)
References
External links
Barred spiral galaxies
Aquarius (constellation)
7065
66766
Astronomical objects discovered in 1864 | NGC 7065 | [
"Astronomy"
] | 97 | [
"Constellations",
"Aquarius (constellation)"
] |
54,494,255 | https://en.wikipedia.org/wiki/Chandrasekhar%27s%20white%20dwarf%20equation | In astrophysics, Chandrasekhar's white dwarf equation is an initial value ordinary differential equation introduced by the Indian American astrophysicist Subrahmanyan Chandrasekhar, in his study of the gravitational potential of completely degenerate white dwarf stars. The equation reads as
with initial conditions
where measures the density of white dwarf, is the non-dimensional radial distance from the center and is a constant which is related to the density of the white dwarf at the center. The boundary of the equation is defined by the condition
such that the range of becomes . This condition is equivalent to saying that the density vanishes at .
Derivation
From the quantum statistics of a completely degenerate electron gas (all the lowest quantum states are occupied), the pressure and the density of a white dwarf are calculated in terms of the maximum electron momentum standardized as , with pressure and density , where
is the mean molecular weight of the gas, and is Planck's constant.
When this is substituted into the hydrostatic equilibrium equation
where is the gravitational constant and is the radial distance, we get
and letting , we have
If we denote the density at the origin as , then a non-dimensional scale
gives
where . In other words, once the above equation is solved the density is given by
The mass interior to a specified point can then be calculated
The radius-mass relation of the white dwarf is usually plotted in the plane -.
Solution near the origin
In the neighborhood of the origin, , Chandrasekhar provided an asymptotic expansion as
where . He also provided numerical solutions for the range .
Equation for small central densities
When the central density is small, the equation can be reduced to a Lane–Emden equation by introducing
to obtain at leading order, the following equation
subjected to the conditions and . Note that although the equation reduces to the Lane–Emden equation with polytropic index , the initial condition is not that of the Lane–Emden equation.
Limiting mass for large central densities
When the central density becomes large, i.e., or equivalently , the governing equation reduces to
subjected to the conditions and . This is exactly the Lane–Emden equation with polytropic index . Note that in this limit of large densities, the radius
tends to zero. The mass of the white dwarf however tends to a finite limit
The Chandrasekhar limit follows from this limit.
See also
Emden–Chandrasekhar equation
Tolman–Oppenheimer–Volkoff equation
References
Equations of astronomy
Equations of physics
Fluid dynamics
Stellar dynamics
White dwarfs
Ordinary differential equations | Chandrasekhar's white dwarf equation | [
"Physics",
"Chemistry",
"Astronomy",
"Mathematics",
"Engineering"
] | 514 | [
"Equations of physics",
"Concepts in astronomy",
"Chemical engineering",
"Mathematical objects",
"Astrophysics",
"Equations",
"Equations of astronomy",
"Piping",
"Fluid dynamics",
"Stellar dynamics"
] |
54,494,563 | https://en.wikipedia.org/wiki/Limit%20and%20colimit%20of%20presheaves | In category theory, a branch of mathematics, a limit or a colimit of presheaves on a category C is a limit or colimit in the functor category .
The category admits small limits and small colimits. Explicitly, if is a functor from a small category I and U is an object in C, then is computed pointwise:
The same is true for small limits. Concretely this means that, for example, a fiber product exists and is computed pointwise.
When C is small, by the Yoneda lemma, one can view C as the full subcategory of . If is a functor, if is a functor from a small category I and if the colimit in is representable; i.e., isomorphic to an object in C, then, in D,
(in particular the colimit on the right exists in D.)
The density theorem states that every presheaf is a colimit of representable presheaves.
Notes
References
Category theory
Sheaf theory | Limit and colimit of presheaves | [
"Mathematics"
] | 215 | [
"Functions and mappings",
"Mathematical structures",
"Category theory stubs",
"Mathematical objects",
"Fields of abstract algebra",
"Sheaf theory",
"Mathematical relations",
"Category theory",
"Topology"
] |
54,495,610 | https://en.wikipedia.org/wiki/Ky%20Fan%20inequality%20%28game%20theory%29 | In mathematics, there are different results that share the common name of the Ky Fan inequality. The Ky Fan inequality presented here is used in game theory to investigate the existence of an equilibrium.
Another Ky Fan inequality is an inequality involving the geometric mean and arithmetic mean of two sets of real numbers of the unit interval.
Statement
Suppose that is a convex compact subset of a Hilbert space and that is a function from to satisfying
is lower semicontinuous for every and
is concave for every .
Then there exists such that
References
Game theory | Ky Fan inequality (game theory) | [
"Mathematics"
] | 107 | [
"Game theory"
] |
54,498,676 | https://en.wikipedia.org/wiki/PSV%20Garuda%20Vega | PSV Garuda Vega is a 2017 Indian Telugu-language action spy film written and directed by Praveen Sattaru. The film is produced by M. Koteswara Raju and stars Rajasekhar, Pooja Kumar, Adith Arun, Shraddha Das, and Kishore, while Sanjay Reddy, Nassar, Ali, Posani Krishna Murali, and Sayaji Shinde play supporting roles.
PSV Garuda Vega was released worldwide on 3 November 2017 where it received positive reviews from critics and emerged as a commercial success at the box office.
Plot
Niranjan Iyer, a hacker, makes a deal for confidential information worth with an unknown person. When he confirms the deal, someone chases after him, but Niranjan manages to escape. Pullela Chandrasekhar, an ACP of the NIA and his wife Swathi, consult a divorce lawyer. Swathi accuses Shekhar of neglecting her and their son and only focusing on his work. Shekhar gets into a car crash when he returns to his office. He finds a high range gun in the other car, which is rare in India, and the other car's owner escapes by shooting Shekhar.
Shekhar decides to arrest the car owner and orders his assistant to check traffic signal CCTV footage to find him. He discovers that the owner is the seasoned assassin Yakub Ali. Shekhar and his team interrogate him, but learn nothing; they decide to bring him to court, but Ali dies on the way, where his phone receives a message, which displays three codes. Having solved the code, Shekhar and his team learn that the codes describe a bomb placed in Charminar and set to explode at 8:00 AM, in just a few hours, and also learns in the investigation, that the opposition leader of the state, Pratap Reddy, is going on a rally against the current government, and they conclude that the bomb is placed to kill Reddy.
Shekhar finds the bomb in an underhole and immediately informs the bomb squad, but they inform him that it is a remote-controlled bomb and that the remote must be used to detonate the bomb, in the vicinity. Shekhar searches for the remote, but to no avail. After Shekhar captures a suspicious man, the latter reveals that the remote is in a white colored-van, being operated by the terrorists. He shoots at the van with the other police officers and kills them. Shekhar finds Niranjan in the crowd, and chases after him, where he successfully arrests him. In custody, Niranjan manages to sell the drive containing the secret information for to Reddy's secretary. After arresting him, Shekhar's senior officer is informed by the government that Shekhar has been assigned to transfer Niranjan to Nagpur.
When Shekhar and Niranjan arrive in Nagpur, a gang attacks them, which forces their van into the river and shoot at them. Shekhar saves Niranjan and leaves towards the forest, where Niranjan reveals that the success of Pokhran Fire testing in 1998 made India to keep its uranium reserves protected from other countries, for future use. The head of the Atomic Department of India, hired four hackers, which include Niranjan, Vishal and two other people, to replace the current photos of their uranium reserves with older photos, so that satellites from other countries cannot see their wealth. They successfully hacked and then left the place. However, Vishal bugged the Indian database of the DAE and learned that a uranium mine in Andhra Pradesh has the highest quantity of uranium in the country.
The head of the DAE has dealt with the MLA of the district and several other ministers, and the hackers were used to hack the satellites to cover up evidence of uranium smuggling. Vishal blackmailed the head of the DAE for , but was killed. Niranjan took the drive and sold it to Reddy's secretary as he would expose the scandal, but Reddy made a deal with the MLA. After the revelation, Shekhar kills the mercenaries sent to kill them and manages to track the location of the main suspect George.
Shekhar and Niranjan leave to meet George to find the data on a remote server of the DAE, but are captured. They are left tied, along with Swathi, on the remote server ship, rigged with explosives to kill them. Shekhar and Niranjan manage to escape and detach the explosives on their ship. They shoot the explosives onto George's ship, by using a leaking high pressurized steam pipe, and successfully kill him and the smugglers. The MLA and several other officers of the scandal are exposed and arrested.
Cast
Rajasekhar as Pullela Chandrashekhar "Shekhar"
Pooja Kumar as Swathi
Adith Arun as Niranjan Iyer
Shraddha Das as Malini
Kishore as George
Sanjay Reddy as Ex-Intelligence Officer and Analyst
Nassar as NIA Head
Ali as Lawyer
Posani Krishna Murali as Opposition Leader Pratap Reddy
Sayaji Shinde as Mining Minister
Srinivas Avasarala as Prakash
Charandeep as NIA Officer Venkat Rao
Ravi Varma as NIA Officer Yadav
Pruthviraj as Doctor
Shatru as Yakub Ali
Sanjay Swaroop as Ravi Naik
Aadarsh Balakrishna
Sunny Leone - special appearance in the song "Deo Deo"
Soundtrack
Soundtrack was composed by Bheems Ceciroleo and Sricharan Pakala.
Controversy
On 12 April 2018, Hyderabad city civil court forbade the film producers, directors, and YouTube from screening this movie. The court passed this interim order as a city-based uranium company filed a complaint against the film, claiming that it shows the corporation in a bad light.
Notes
References
External links
2010s Telugu-language films
Indian nonlinear narrative films
Indian spy thriller films
2010s spy thriller films
Films shot in Hyderabad, India
Films set in Hyderabad, India
Films about computing
Techno-thriller films
Films about security and surveillance
Films about Islamic terrorism in India
Films shot in Chennai
Fictional portrayals of the Telangana Police
Films about murder
Films about mass murder
Intelligence Bureau (India) in fiction
Films about the Research and Analysis Wing
Films scored by Sricharan Pakala
Films scored by Bheems Ceciroleo
Films directed by Praveen Sattaru
Films set on ships | PSV Garuda Vega | [
"Technology"
] | 1,300 | [
"Works about computing",
"Films about computing"
] |
51,623,631 | https://en.wikipedia.org/wiki/Discovery%20and%20development%20of%20gastrointestinal%20lipase%20inhibitors | Lipase inhibitors belong to a drug class that is used as an antiobesity agent. Their mode of action is to inhibit gastric and pancreatic lipases, enzymes that play an important role in the digestion of dietary fat. Lipase inhibitors are classified in the ATC-classification system as A08AB (peripherally acting antiobesity products).
Numerous compounds have been either isolated from nature, semi-synthesized, or fully synthesized and then screened for their lipase inhibitory activity but the only lipase inhibitor on the market (October 2016) is orlistat (Xenical, Alli).
Lipase inhibitors have also shown anticancer activity, by inhibiting fatty acid synthase.
Discovery of lipase inhibitors and their development
Pancreatic lipase inhibitor was originally discovered and isolated from fermented broth of the Streptomyces toxytricini bacterium in 1981 and named lipstatin. It is a selective and potent irreversible inhibitor of human gastric and pancreatic lipases. Tetrahydrolipstatin, more commonly known as orlistat, is a saturated derivative produced by hydrogenation. It was developed in 1983 by Hoffmann-La Roche and is a more simple and stable compound than lipstatin. For that reason orlistat was chosen over lipstatin for development as an anti-obesity drug. It is the only available FDA-approved oral lipase inhibitor and is known on the market as Xenical and Alli.
Initially orlistat was developed as a treatment for dyslipidemia, not as an anti-obesity agent. When researchers found out that it promotes less energy uptake, the focus was switched to obesity.
Orlistat has a few adverse effects. Most reported side effects are gastrointestinal; including liquid stools, steatorrhea and abdominal pain. More severe and serious are interactions between orlistat and anticoagulants when given in combination. It can increase INR which can lead to insufficient anticoagulant treatment and bleeding. These adverse effects of orlistat are more common early in the therapy but usually decrease with time. Pancreatic lipases do not only affect the hydrolysis of triglycerides but are also necessary for hydrolysis of fat soluble vitamins. Due to this, the absorption of fat-soluble vitamins may decrease. Therefore, it is recommended to take a multiple-vitamin supplement during orlistat therapy.
Cetilistat, a new lipase inhibitor, is an experimental drug for obesity. In October 2016 the drug was still in clinical trials.
Cetilistat was developed to overcome the adverse effects on the gastrointestinal tract of orlistat. It has a different structure but similar inhibition activity to the gastrointestinal lipase. However cetilistat interacts differently with the fat micelles from digested food, therefore it has less side effects and better tolerability.
Mechanism of action
The lipase inhibitors lipstatin and orlistat act locally in the intestinal tract. They are minimally absorbed in the circulation because of their lipophilicity. Hence, they do not affect systemic lipases.
The mechanism of lipase inhibitors in fat digestion is shown in figure 1. These inhibitors bind covalently as an ester to the serine hydroxyl group at the active site on pancreatic- and gastric lipases and form a stable complex.
This results in a conformational change in the enzyme which causes exposing of the catalytic active site. When the active site is exposed, the hydroxyl group on the serine residue is acylated. This leads to irreversible inactivation of the enzyme.
The inactive lipase is incapable of hydrolysing fats into absorbable fatty acids and monoglycerides, therefore triglycerides are excreted undigested with faeces. With this mode of action calorie uptake from fat in food is limited, hence body weight is reduced. The main role of lipase inhibitors is therefore to inhibit lipases in the gastrointestinal tract, but they do not have significant activity against proteases, amylases or other digestive enzymes.
Cetilistat has a bicyclic structure but lacks the β-lactone ring. It acts in a similar way as a typical lipase inhibitor that has the β-lactone structure.
Drug target
Lipases in the gastrointestinal tract play a critical role in fat digestion. More than 95% of fat in food consists of triglycerides, which are categorized based on the length of fatty acids connected to glyceride backbone. The length of long-chain triglycerides prevent their absorption through the intestinal mucosa. For that reason lipases in the gastrointestinal tract must hydrolyse it to smaller molecules, free fatty acids and monoglyceride, before absorption can occur.
Gastric lipase
Gastric- and lingual lipases are the two acidic lipolytic enzymes that origin preduodenal but the gastric lipase is in much higher levels in humans.
Gastric lipase is synthesized and secreted from gastric chief cells in the stomach and is stable at pH 1,5-8,
but has maximum activity at pH 3-6.
Fat digestion begins when gastric lipase hydrolyses dietary triglycerides, by cleaving only one long-, medium- or short-acyl chain from the glyceride backbone and release free fatty acids and diacylglycerols. The enzyme hydrolyses esters at position sn-3, the acyl chain at the bottom, more rapidly than esters at sn-1 position, the acyl chain on the top of the glyceride backbone. However the gastric lipase activity against phospholipids and cholesterol esters is poor.
Gastric lipase is composed of 379 amino acids. Fully glycosylated protein is 50kDa and unglycosylated enzyme is 43kDa. However deglycosylation of the enzyme does not affect the activity of the enzyme. The hydrophobic region around Ser152, which has the hexapeptide sequence Val-Gly-His-Ser-Gln-Gly, is essential for the catalytic activity of gastric lipase. At the N-terminal, Lys4 is necessary for the enzyme to bind at lipid-water interfaces.
Pancreatic lipase
Pancreatic lipase is the most important lipolytic enzyme in the gastrointestinal tract and is essential for fat digestion.
Pancreatic lipase is secreted from acinar cells in the pancreas and its secretion, with the pancreatic juice to the small intestine, is stimulated by hormones. These hormones are induced in the stomach by hydrolysed products in gastric digestion.
The pancreatic lipase is secreted to the small intestine where it is most active, at pH 7-7,5.
Pancreatic lipase hydrolyses triglycerides and diglycerides by cleaving acyl chains at the sn-1 and sn-3 position
and releases free fatty acids and 2-monoglycerides.
The pancreatic lipase consists of 465 amino acids. Schematic picture of pancreatic lipase is shown in figure 2. Pancreatic and gastric lipases share little homology but have the same hydrophobic region at the active site, which is important for the lipolytic activity. The hydrophobic region has the hexapeptide sequence Val-Gly-His-Ser-Gln-Gly and is at Ser153 in pancreatic lipases but Ser152 in gastric lipases.
Chemistry of lipase inhibitors
β-lactone class
The chemical structure of compounds play an important role in binding to their target. The most important and necessary chemical group for the binding and activity of these compounds is the β-lactone (beta-lactone) ring which is the central pharmacophore. The β-lactone moiety is shown in red in the structures in the table below.
Researches have shown that cleavage of the β-lactone ring results in loss of inhibitory activity of the inhibitors, which makes the β-lactone structure a crucial part in biological activity.
The lactone ring structure binds irreversibly to the active site of the lipase and forms covalent bond, which leads to inhibition.
Drugs of this class include:
Lipstatin, the first known lipase inhibitor, comes from a natural source. It has a β-propiolactone ring, which has a 2,3-trans-disubstituted linear alkyl chains located at the α- (C6) and β-site (C13) of the compound. It contains N-formyl-L-leucine amino acid connected to the β-alkyl chain via ester-bond. The structure of Lipstatin is shown in the table below.
Orlistat is a semi-synthetic compound, which has a similar structure to lipstatin. They differ only in the saturation of the β-alkyl chain, where orlistat is saturated while lipstatin has two double bonds in the side chain. The structure of orlistat is shown in the table from the last section.
Structure-activity relationship (SAR)
Most natural lipase inhibitors differ only in the structure of the side chains and the nature of the linked amino acids, but have the same β-lactone ring in (S)-configuration as a primary structure.
Besides the role of the β-lactone ring in structure-activity relationship, the nature of the functional groups (e.g. ester or ether and the chain length at the β-site) also matter. However a trans-position of the side-chains on the β-lactone ring is crucial for its activity.
Synthetic lipase inhibitor: cetilistat
Cetilistat is a synthetic lipase inhibitor. Instead of having a β-lactone structure like most of the lipase inhibitors, it has a bicyclic benzoxazinone ring. It is also a lipophilic compound but differs in the hydro- and lipophilic side chain.
The structure and more information about Cetilistat is shown in the table on the right.
Other lipase inhibitors
Other lipase inhibitors have been recognized, e.g. from different plant products. These include alkaloids, carotenoids, glycosides, polyphenols, polysaccharides, saponins and terpenoids. However, none of these have been used clinically as lipase inhibitors. More active lipase inhibitors are the lipophilic compounds from microbial sources.
Lipase inhibitors from microbial source can be divided into two classes based on their structure. Those who have a β-lactone ring are lipstatin, valilactone, percyquinin, panclicin A-E, ebelactone A and B, vibralactone and esterastin. Those who do not have a β-lactone ring are (E)-4-amino styryl acetate, ε–polylysine and caulerpenyne.
Lipase inhibitors have also been made synthetically, e.g. cetilistat, based on the structure of triglycerides and other natural lipase substrates. However, the synthetic lipase inhibitors differ in structure and some of them lack the β-lactone ring.
Additional activities
Potential for cancer treatment
As further discussed, orlistat is a pancreatic and gastric lipase inhibitor. Orlistat is also a potent thioesterase inhibitor and therefore inhibits fatty acid synthase (FAS). Since FAS is essential for tumor cells, for its growth and survival, and is upregulated and overexpressed in variety of tumors, scientists have high expectations for FAS as an oncology drug target. Orlistat inhibits FAS with the same mechanism as it does with pancreatic lipase, that is by binding covalently to the active serine site.
This effect of orlistat as a FAS-inhibitor was first identified in a high throughput screening for enzymes with prostate cancer inhibition activity. However FAS is resistant to many cancer medicines. Orlistat sensitizes these FAS resistance cancer drugs, by inhibiting FAS. There is a low FAS expression in normal tissues so the activity of orlistat on normal cells is limited.
Because of the difference in FAS expression between normal cells and cancer cells, orlistat selectively targets tumor cells. Due to this FAS is a potential drug target in cancer therapy.
Orlistat works locally in the intestines as a lipase inhibitor, and therefore suffers from several limitations in its development as a systemic drug. Its poor bioavailability and solubility are the main reasons to develop a new anticancer analogue to overcome these limitations.
References
Lipase inhibitors
Gastrointestinal lipase inhibitors | Discovery and development of gastrointestinal lipase inhibitors | [
"Chemistry",
"Biology"
] | 2,751 | [
"Life sciences industry",
"Medicinal chemistry",
"Drug discovery"
] |
51,624,378 | https://en.wikipedia.org/wiki/Mixed%20conductor | Mixed conductors, also known as mixed ion-electron conductors (MIEC), are a single-phase material that has significant conduction ionically and electronically. Due to the mixed conduction, a formally neutral species can transport in a solid and therefore mass storage and redistribution are enabled. Mixed conductors are well known in conjugation with high-temperature superconductivity and are able to capacitate rapid solid-state reactions.
They are used as catalysts (for oxidation), permeation membranes, sensors, and electrodes in batteries and fuel cells, because they allow for rapidly transducing chemical signals and permeating chemical components.
Strontium titanate (), titanium dioxide (), , cerium(IV) oxide (), lithium iron phosphate (), and are examples of mixed conductors.
Introduction
MIEC materials tend to be nonstoichiometric oxides, many of which have perovskite structures with rare earth metals on the A-site and transition metals on the B-site. Substituting various ions into the lattice of such an oxide can result in increased electronic conductivity through the formation of holes and introduce ionic conductivity by developing oxygen vacancies. This mechanism is known as defect theory, which states that defects like these offer additional pathways that favor fast diffusion. Other promising materials include those with pyrochlore, brownmillerite, Ruddlesden-Popper, and orthorhombic K2NiF4-type structures.
However, true (single-phase) MIECs that are compatible with other design parameters can be difficult to find, so many researchers have turned to heterogeneous MIEC materials (H-MIECs). An H-MIEC is a composite mixture of two phases: one for conducting ions, and another conducting electrons or holes. These materials are desirable for the ability to tune their properties for specific applications by adjusting concentration levels to achieve optimal electron and ion transport. Porous H-MIECs also incorporate a third phase in the form of pores, which allow the formation of triple phase boundaries (TPBs) between the three phases that provide high catalytic activity.
Applications
SOFC/SOEC
Current state-of-the-art solid oxide fuel cells (SOFCs) and electrolysis cells (SOECs) frequently incorporate electrodes made of MIEC materials. SOFCs are unique among fuel cells in that negatively charged ions (O2-) are transported from the cathode to the anode across the electrolyte, making MIEC cathode materials critical to achieving high performance. These fuel cells operate with the following oxidation-reduction reaction:
Anode Reaction: 2H2 + 2O2− → 2H2O + 4e−
Cathode Reaction: O2 + 4e− → 2O2−
Overall Cell Reaction: 2H2 + O2 → 2H2O
MIECs like lanthanum strontium cobalt ferrite (LSCF) are frequently the subject of modern fuel cell research, as they enable the reduction reaction to occur over the entire cathode surface area instead of only at the cathode/electrolyte interface.
One of the most commonly used oxygen electrode (cathode) materials is the H-MIEC LSM-YSZ, consisting of lanthanum strontium manganite (LSM) infiltrated onto a Y2O3-doped ZrO2 scaffold. The LSM nanoparticles are deposited on the walls of the porous YSZ scaffold to provide an electronically conductive pathway and a high density of TPBs for the reduction reaction to occur.
See also
Fast ion conductor
Proton conductor
Superconductivity
References
Electrical conductors
Electrochemistry
Solid-state chemistry
Superconductivity | Mixed conductor | [
"Physics",
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] | 785 | [
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"Condensed matter physics",
"Electrical conductors",
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51,624,530 | https://en.wikipedia.org/wiki/Working%20level | Working level (WL) is a historical unit of concentration of radioactive decay products of radon, applied to uranium mining environment. One working level refers to the concentration of short-lived decay products of radon in equilibrium with 3,700 Bq/m (100 pCi/L) in air. These decay products would emit 1.3 × 10 MeV in complete decay. The Nuclear Regulatory Commission uses this definition.
Working level month (WLM) is a closely related quantity, referring to exposure to one working level for 170 hours per month. This comes from assuming a 40-hour work week.
In 2002, the NRC regulations limited exposure in mines to 0.3 WL, which was comparable with the standards of International Commission on Radiological Protection at the time.
References
Units of radiation dose
Radon
Radiation protection
Mine safety | Working level | [
"Mathematics"
] | 172 | [
"Quantity",
"Units of radiation dose",
"Units of measurement"
] |
51,626,919 | https://en.wikipedia.org/wiki/IBI%20Group | IBI Group Inc. is a Canadian-based architecture, engineering, planning, and technology firm operating from over 60 offices in 12 countries across the world.
Founded in 1974 in Toronto, Canada, IBI Group has since been ranked as one of the largest architecture or architecture/engineering firms in the world: in 2011 it ranked 4th or 6th (depending on the methodology used); in 2016 it was ranked as the 8th largest architecture firm (with 836 fee-earning architects) by BD Online; and in 2016 its United States operations were ranked by ArchDaily as the 13th largest architecture firm in the USA.
As of 2022, IBI Group has approximately 3,400 employees and more than 60 offices located across six continents. IBI Group's consulting services business is concentrated in three practice areas: Intelligence, Buildings and Infrastructure. By integrating productivity tools, processes and technology innovations developed through IBI's Intelligence practice, the company has been able to drive incremental growth in its traditional Buildings and Infrastructures practices, while generating more efficient results for IBI clients.
On September 27, 2022, it was acquired by Arcadis.
History
The IBI Group was founded in Toronto by nine partners to provide professional planning and design services for urban development and transportation projects.
The firm merged with Robbie/Young + Wright Architects to become Robbie Young + Wright / IBI Group Architects, with noted Toronto architect Rod Robbie as chairman emeritus. In 2004 the firm became a publicly owned entity through the formation of the IBI Income Fund. In 2010 the Fund was converted to a corporation, IBI Group Inc.
The firm's name was derived from the last initials of its two founding principals, Neal Irwin and Phil Beinhaker. The firm has rebranded itself, stating the IBI stands for "Intelligence, Buildings, and Infrastructure."
In September 2022, IBI Group was acquired by Arcadis.
Major acquisitions
Since 2000 the firm has expanded through mergers and acquisitions of consulting firms in multiple locations. Some have been folded into the IBI Group brand and others have maintained a distinct identity. The major acquisitions below are listed in chronological order.
Cumming Cockburn
In 2004, IBI Group acquired the Ontario architecture and consulting firm Cumming Cockburn, as well as its subsidiaries CCL Consultants and Marshall Cumming & Associates.
Vancouver office
The Vancouver office expanded through the 2005 merger of Hancock Bruckner, Eng + Wright; Lawrence Doyle Architects; and Young + Wright Architects.
Grey-Noble & Grey-Noble
In 2005 the Newmarket, Ontario-based architectural firm of Grey-Noble & Grey-Noble was acquired.
Thomas Blurock Architects
In 2006 the Costa Mesa, California-based educational project-focused firm of Thomas Blurock Architects was acquired and incorporated.
Page+Steele
In 2008 the Toronto-based firm of Page+Steele, Architects was acquired and operates as Page+Steele/IBI Group.
Gruzen Samton Architects
In 2009 the New York City based firm of Gruzen Samton Architects, Planners & Interior Designers was acquired. The firm was founded in 1936 and operates as IBI Group.
Group Architects
In 2009 the small Toronto-based firm of Group Architects was acquired. IBI relocated and redistributed its team to a new location and the company and presence dissolved entirely through the following years.
BFGC Architects Planners
In 2009, BFGC Architects Planners, with offices in Bakersfield, San Luis Obispo and San Jose, California, was acquired.
Nightingale Architects
In 2010, Nightingale Architects, with four offices in the United Kingdom, including in London and Cardiff, was acquired for £13.1 million.
Dull Olson Weekes Architects
In 2010, IBI acquired the Portland, Oregon-based firm of Dull Olson Weekes Architects, a regional specialist in the design of educational facilities with offices in Portland and Seattle, Washington. It has received multiple awards for its work, including the CEFPI/A4LE James D. MacConnell Award for excellence in design and planning, in 2009 for the Rosa Parks School and Community Campus at New Columbia, in 2014 for Trillium Creek Primary School, and in 2020 as a finalist for Mary Lyon Elementary School. The firm operates as IBI Group Architects.
Cardinal Hardy Architectes
In 2011, the Quebec-based firm of Cardinal Hardy merged with Beinhaker Architecte (within the IBI Group), and became known as Cardinal Hardy Beinhaker Architecte. Groupe Cardinal Hardy merged into the IBI Group. Three years later, in late 2014, it was sold to Montreal-based architecture group Lemay.
Carol R. Johnson Associates
In 2011 the Boston based landscape architecture firm Carol R. Johnson Associates was acquired.
Bay Architects
In 2011 the Houston, Texas-based firm of Bay Architects was acquired.
Taylor Young
In 2012, Taylor Young, a United Kingdom-based architectural and master-planning practice headquartered in Cheshire and with offices in Liverpool and London, was acquired.
M-E Companies
In 2012, M-E Companies, an Ohio-based engineering firm with offices in Westerville, Cincinnati and Canton was acquired.
Aspyr
IBI acquired the British Columbia-based Aspyr Engineering on September 3, 2019.
Cole Engineering Group
IBI acquired the Cole Engineering Group on December 1, 2020.
Major projects
Major projects, ordered by type, are:
Masterplans
Benxi New City, Benxi, China
2012 Summer Olympics - Travel demand management program, London
CaféTO, Toronto
Al Bandar Development Master Plan, Muscat
Bhubaneswar Smart City Strategy and Implementation, Bhubaneswar
Government
States of Jersey Police headquarters, Jersey
Fire Station 16 and Calgary Fire Department Headquarter, Calgary
Cultural
Parliament of Canada Visitor Centre Phase 1 (with Moriyama & Teshima Architects), Ottawa
Boca Raton Center for the Arts and Innovation, Boca Raton
Education
41 Cooper Square, New York City
Diamond Ranch High School (executive architect), Pomona, California
École secondaire catholique Père-Philippe-Lamarche, Toronto, Ontario
Franklin High School renovation
Heschel School - Ronald P. Stanton Campus, New York City
Rosa Parks School and Community Campus at New Columbia
Ridgeview High School (Redmond, Oregon)
Sabine Pass K-12 School, Sabine Pass
San Jacinto College Maritime Center, Houston
Sandy High School, Sandy, Oregon
School of One, New York City
Stuyvesant High School, New York City
Trillium Creek Primary School, Portland
Transportation
Evergreen Point Floating Bridge, Lake Washington, Washington
Pioneer Village station, Toronto
Victoria Park station (Toronto) renovation
Confederation Line, Ottawa - station design
Bloomington GO Station, Richmond Hill, Ontario
Line 5 Eglinton, Toronto
Office
Ericsson R&D Complex, Research Triangle Park, North Carolina
Boston Landing, New Balance World Headquarters, Boston
Leisure
Delta Toronto Hotel, Toronto
Oceanside Dolphin Hotel, San Diego
Mixed use
Holt Renfrew, Calgary, Vancouver and Mississauga
Parq Vancouver, Vancouver
Residential
88 Scott Street, Toronto
Atlantis The Royal, Dubai
Healthcare
BC Cancer Research Centre, Vancouver (with Henriquez Partners Architects)
Optegra Eye Hospital, London
Queen Elizabeth University Hospital, Glasgow
Royal Hospital for Children, Glasgow
Products
HotSpot
IBI Group acquired HotSpot in June 2022 for $5.74 million. Founded in 2013, HotSpot allows users to pay for municipal parking from their phones, or pay for and receive real-time updates about bus services, as well as order and pay for taxis.
CurbIQ
CurbIQ is IBI Group's curbside management tool intended to allow municipalities and mobility companies to manage curbside operations by digitizing their regulation. It was created as a result of IBI Group's Curbside Management Strategy created for the City of Toronto for the 2015 Pan American and Parapan American Games.
CurbIQ consists of four modules:
Curb Viewer - map-based visualization tool allows municipalities to visualise their existing curbside regulations.
Curb Manager - simplified GIS platform for municipalities to efficiently manage their curbside by adding, removing, or modifying curbside regulations.
Curb Analyzer - quantifies the designations of curb spaces to provide city planners with trends on their usage
Curb Rules API - to allow transportation network companies, such as ridesharing applications, and commercial vehicle dispatches, to add information about curbside regulations to their own applications.
CurbIQ was used to launch a SENATOR pilot project in Dublin, Ireland that aimed to create a new logistics system to improve the city's transportation network in 2022.
Nspace
Nspace is a desk and conference room booking and visitor management application intended to support flexible work arrangements.
Acquisition by Arcadis
IBI Group announced on July 18, 2022, that it has entered into an agreement with the Dutch design, engineering and management consulting company Arcadis to "acquire all issued and outstanding shares" for $19.50 per share, a thirty percent premium on the day's closing price. The approximately $873 million acquisition was finalised in September 2022 after a shareholder vote.
References
External links
IBI Group corporate structure (see page 7)
2022 mergers and acquisitions
Architecture firms of Canada
Companies based in Toronto
Architecture firms based in Oregon
Engineering consulting firms of Canada
International engineering consulting firms
Companies formerly listed on the Toronto Stock Exchange | IBI Group | [
"Engineering"
] | 1,873 | [
"Engineering consulting firms",
"International engineering consulting firms"
] |
51,627,377 | https://en.wikipedia.org/wiki/Sagenomella%20keratitidis | Sagenomella keratitidis is a hyphomycete discovered as its own species in 2008 by Sung-Yaon Hsieh et al. at the Institute of Plant and Microbial Biology and the National Taiwan University Hospital.
History and taxonomy
Studies prior to 2009 showed evidence of fungal keratitis development with the use of contact lenses, but very little evidence of the development of keratitis associated with contact lens wear. Fungal keratitis associated with contact lens wear is quite rare when compared to microbial keratitis. Fungal keratitis accounts for only 5% of keratitides. The majority of Sagenomella species are soil-associated. S. keratitidis is the first species that is associated with the human eye. It was discovered in 2010 that Sagenomella can be grouped into three distinct categories, and these groups are not all descended from a common ancestor. DNA sequence analysis studies showed that S. keratitidis is most closely related to Sagenomella sclerotialis with two species showing 99% DNA homology. The researchers in Taiwan proposed the genus Sagenomella based on growth pattern and morphology.
Growth and morphology
S. keratitidis has very slow growth on a range of cultures, making experiments involving isolation and purification very difficult. It has translucent, linked ameroconidia and very small conidiophores— its unusually small, few conidiophores are the reason why the colonies are white rather than gray. S. keratitidis species have spherical, phialidic conidia. Sagenomella species are closely related to Acremonium, but distinguished by their linked conidia. Sagenomella species are also distinguished from Acremonium species by their sharp-tipped, abruptly-ending conidia. S. keratitidis lacks chlamydospores.
S. keratitidis may superficially resemble another member of its genus,S.humicola, under a microscope, but can be distinguished from S.humicola because of its extremely slow growth and lack of chlamydospores.
Physiology
The species of genus Sagenomella generally grow between the temperatures of 20-23 °C on malt extract agar, and are known for their slow growth. Little is known so far about the physiology of S. keratitidis but its close relative, S.chlamydospora, grows best between a temperature of 37 °C and 40 °C, above which it does not survive. Ideal growth for Sagenomella species is at 27 °C.S. keratitidis was found to grow better on media that had been modified with yeast.
Pathogenicity
Sagenomella species normally cause unspecific symptoms and infections of Sagenomella are difficult to diagnose because this is an uncommon genus of fungus.S. keratitidis was found to cause inflammation of the cornea, or keratitis, in an individual who wore contact lenses. So far, this has been the only case of keratitis found to be caused by S. keratitidis.S. keratitidis is not as pathogenic as other members of the same genus, such as S.chlamydospora, which can cause serious mycosis in canines. Canine S.chlamydospora infections can cause the animal to limp, experience pain in its spine, and feel a general lack of energy. If left untreated, these infections can spread to humans.
Habitat and ecology
S. keratitidis is a human eye pathogen, unlike its other genus counterparts, whose habitat is either soil, manure, or fodder. Although rare, it may occur due to poor sanitation in individuals who wear contact lenses.
References
Trichocomaceae
Fungi described in 2009
Fungus species | Sagenomella keratitidis | [
"Biology"
] | 789 | [
"Fungi",
"Fungus species"
] |
51,628,478 | https://en.wikipedia.org/wiki/German%20Climate%20Action%20Plan%202050 | The German Climate Action Plan 2050 () is a climate protection policy document approved by the German government on 14November 2016. The plan outlines measures by which Germany can meet its various national greenhouse gas emissions reduction goals through to 2050 (see table) and service its international commitments under the 2016 Paris Climate Agreement. The Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB), under minister Barbara Hendricks, led the development of the plan. The plan was progressively watered down since a draft was first leaked in early May 2016. Projections from the environment ministry in September 2016 indicate that Germany will likely miss its 2020 climate target.
The Climate Action Plan2050 should not be confused with an earlier document, the Climate Action Programme2020 (), approved in December 2014 and which only covers the period until 2020. In early 2017 it was agreed that the 2020 Programme would be scrapped.
Climate targets
Germany announced the following official greenhouse gas emissions targets on 28September 2010.
Regarding European Union policy, in October 2009 the Council of the European Union agreed that the appropriate abatement objective for Europe and other developed economies was 80–95% below 1990 levels by 2050 (consistent with Germany).
In October 2014 the European Council endorsed a binding European Union target of an at least 40% reduction in domestic greenhouse gas emissions by 2030 relative to 1990 (less stringent than Germany).
Climate Action Programme 2020
The Climate Action Programme2020 () is an attempt by Germany to help meet its official 2020 greenhouse gas emissions reductions target after a 'climate gap' had been identified. Projections from 2013 show Germany may miss its 40% reductions target by about without additional measures. The first draft of the programme was released in 2014. How best to control the contribution from coal-fired generation remained controversial, but economy and energy minister Sigmar Gabriel (SPD) dismissed plans aired in his ministry in October 2014 to retire 10GW of coal capacity.
The Climate Action Programme2020 was approved on 3December 2014. The official document is available in English.
The most significant part of the new package is a pledge to cut electricity sector emissions substantially by 2020. To do so, the government proposes to cap emissions from the sector at 22million tonnes between 2016 and 2020 or 4.4million tonnes each year. Once the cap is in place, energy companies will be allocated allowances based on their current emissions. If they cut their emissions by a greater amount, they may be able to sell their surplus to other companies. The package also contains measures to improve energy efficiency and the transport sector. Environmental groups criticized the package for not going far enough in reducing the reliance on coal-fired generation.
In December 2015, the government remained confident that its 2020 emissions target will be met through the measures contained in the programme and elsewhere. However, a government report, released on 30September 2016, shows that Germany will meet its 2020 greenhouse gas commitments only under "a best case scenario". The report, prepared for the European Union, is available in German. The analysis projects Germany's greenhouse gas emissions forward for the next 20years.
A PwC report from November 2016 evaluates the economic and ecological effects of the Climate Action Programme2020 and finds that the economic benefits outweigh the costs of the proposed measures. Based on the report, environment minister Barbara Hendricks said in a press release that "the programme will create additional jobs and a GDP increase of 1% by 2020".
In early 2017, the government agreed to scrap the 2020 plan entirely.
Development of the Climate Action Plan 2050
The history of the Climate Action Plan2050 is quite involved. The Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) is the lead agency for the plan, under the direction of environment minister Barbara Hendricks (SPD). A novel public consultation process was utilized to collect ideas from state and city governments, advocacy groups, and citizens and these ideas were then used to help create the first version. Internal drafts of the plan were leaked three times to the media in 2016, the first in early May, the second in late June, and the third in early November.
Coalition agreement: 2013
The notion of a climate action plan arose from the coalition agreement between the CDU, CSU, and SPD parties in 2013. The agreement stated:
Public consultation: 25 June 2015 – 19 March 2016
A public consultation with stakeholders began on 2015 with a Kick-off Conference in Berlin. A discussion paper for this exercise was dated 9June 2015 and is available in English. The consultation process involved a series of meetings with states (), municipalities, associations, and citizens, with delegates selected to represent these various groupings in subsequent forums. The process was organized by the Wuppertal Institute and the dialog agency IFOK. The resulting proposals for action were collated and presented at a meeting at the environment ministry (BMUB) on 2016. The final report is available in German. This input was used to help create the first draft of the Climate Action Plan2050. The German government also explained its public participation process at the 2015 United Nations Climate Change Conference () on 9December 2015. The design of the consultation process was novel for Germany. An explanatory video from the BMUB is available.
First leaked draft: early May 2016
A draft of the plan was leaked to media for the first time in early May 2016. It was the result of consolidating a long catalog of measures from the consultation process. The leaked plan included proposals for:
ecological tax reform and the internalization of environmental costs
climate friendly investment
reducing emissions from coal and a phase-out of coal () well before 2050
making both old and new buildings climate-neutral
the digitalisation and electrification of the transport sector
a floor price for carbon and climate-aware investment
a reduction in the numbers of ruminant animals and for the public to eat less meat
the use forests as carbon sinks and the renaturalisation of moorlands for the same purpose
the investigation of a new national welfare index
the embedding of climate protection in local and regional public services
The plan also suggested a "pluralistic" (meaning diverse groups are represented) commission be established, tasked with developing a coal phase-out plan by .
Following the leaked document, state governments became increasingly concerned that they were being railroaded into climate change goals that could damage their regional economies.
Second leaked draft: 21 June 2016
A draft of the plan was leaked to media for the second time in late June 2016. The draft was dated 21June 2016 and is available for download in German. Unlike the first leak, this draft was compiled after consultation with the economics and energy ministry (BMWi).
The new draft shows that individual sectors may escape specific emissions targets and that an end date for coal-fired generation has been omitted. Earlier versions had contained sector-specific targets for energy, transport, industry, buildings, and agriculture. The energy sector which was previously slated to make a "considerable" contribution is now required to make an "adequate" contribution. Rather than saying that coal-fired generation must "end well before 2050" the new draft emphasizes that "the importance of power production from coal will decrease" and that there will be a "step-by-step reduction". The previous draft stated that the transport sector would need to deliver "disproportionately high" emissions reductions (on account of the poor performance of the sector to date), that has now diminished to an "ambitious" contribution. Other proposals remain, including the development of ecological tax reform. The plan also includes targets for modernizing the heating and cooling systems in buildings, including no new fossil-fueled heating systems in houses after 2030.
The proposal for a Commission on Climate Protection, Growth, Structural Change, and the Completion of the Energiewende () remains, but now without the specific task of developing a roadmap for the phase-out of coal.
The weakening of the plan is also a result of industry associations repeatedly criticizing sector targets and itemized measures, which they fear would harm Germany's economic performance and international competitiveness.
Official draft: 6 September 2016
An official draft was released on 6September 2016 and is available in German. This draft retains a provision for the establishment of a Commission on Climate Protection, Growth, Structural Change, and the Completion of the Energiewende.
The content however has been watered down considerably. Concrete emissions reductions targets were removed altogether. The previously leaked June 2016 draft stated that by 2030 "a large majority of newly registered cars" would need to be powered by either electricity or biofuels. However, the new draft merely states that "the government aims to significantly lower car emissions by 2030" and that electric cars can contribute to that goal.
Environmental groups have become increasingly critical of the plan as each iteration led to a watering down of its climate protection provisions. The NGOs were particularly concerned about the lack of detail concerning a coal phase-out. On 24 September 2016, Greenpeace Germany issued a report critical of the watering down of the results of the consultation process.
Cabinet deliberations: late 2016
In late 2016, the plan went to the Chancellery () to coordinate the final version to be agreed by the German cabinet ().
Media reports in late October 2016 suggest a deepening rift between the economics and energy ministry (BMWi) and the environment ministry (BMUB) over the plan and the exit process for coal-fired generation (). Economy and energy minister Sigmar Gabriel opposes the setting of a coal exit date before job alternatives for lignite workers have been determined.
A revised draft plan, circulated by the environment ministry on 4November 2016, was obtained by Süddeutsche Zeitung. The plan has become more stringent and now includes passages that had earlier been removed during the negotiations between ministries. The new plan also precludes new coal-fired generation and the expansion of existing open-pit mines and calls on the government to lobby for an EU-wide floor price for auctioned EU ETS emissions allowances.
On 7November 2016, over 40 German companies, including energy suppliers EnBW and MVV Energie and network operator 50Hertz, together with Commerzbank, Deutsche Telekom, IKEA, and Hochtief, are lobbying for a more ambitious program, one which ensures that Germany's Paris Agreement commitments are met. The companies want sector-specific emissions targets for 2030 and state that "only in this way can new business models and concrete plans for decarbonisation be developed". They want the goal to be the "rapid switch to 100% renewable energy". British economist Nicholas Stern also backs a more ambitious plan. The original statement from the companies is available.
On 8November 2016, economy and energy minister Gabriel vetoed the plan amid concerns by trade union IG BCE and supported by the BDI industry group. The draft does not timetable a phase-out for brown coal, notwithstanding Gabriel said he expected brown coal to remain in use past 2040. On 11November 2016, Reuters news agency reported that chancellor Angela Merkel and ministers Gabriel and Hendricks had agreed on a new draft.
Approval: 14 November 2016
On 14November 2016, the cabinet officially adopted and released the new plan. It was overseen by a CDU/CSU/SPD grand coalition government, led by Angela Merkel. The timing allowed environment minister Barbara Hendricks to present the German plan at the COP22 climate talks held in Marrakesh, Morocco. Canada, Mexico, and the US also presented climate action plans.
Climate Action Plan 2050
The official Climate Action Plan2050 is available in German and runs to 91pages. An official summary of the principles and goals underpinning the plan is available in English.
The plan is to be supplemented by a program of policy measures, developed by the German parliament (), with the first such program to be in place in 2018. Annual reporting will track progress and should facilitate specific policy adjustments where needed.
Preamble
The plan begins with a preamble that states that the document is an evolving work in progress and "cannot and does not want to be a detailed masterplan". It adds that there will be "no rigid provisions" and that the plan is technology neutral and open to innovation. The preamble stresses that the government will simultaneously maintain German competitiveness:
The preamble also reiterates Germany's 2010 climate targets (see table) and its 2016 Paris Agreement commitment.
Sector targets
Sector targets remained controversial during the development of the plan. Notwithstanding, the official document now specifies sector targets for the first time under a national climate protection policy. The initial sector targets will be subject to a comprehensive impact assessment and consultation and may well be adjusted as a result in 2018.
For comparison, the Paris Agreement nationally determined contribution (NDC) for Germany is −55% relative to 1990 (which accords with the final cell in the table).
Commission for growth, structural change, and regional development
The plan establishes a commission for growth, structural change, and regional development. Unlike earlier versions, the commission will not be tasked with setting a date for an exit from coal. Instead, the commission will "support the structural changes" resulting from transformation and will "develop a mix of instruments that will bring together economic development, structural change, social acceptability and climate protection". The commission will be based at the economics and energy ministry, but will consult with other ministries, federal states, municipalities, and unions, as well as with representatives of "affected" companies and regions. The commission is scheduled to start work at the beginning of 2018 and to report at the end of 2018.
EU Emissions Trading System
The plan stresses to role of the European Union Emission Trading System (EUETS) as the primary climate protection instrument covering the energy sector and parts of industry in central Europe. The government wants to strengthen price signaling and will campaign to make the EUETS "effective" at a European level. Earlier provisions to set a floor price for emissions allowances were removed.
Energy sector
The energy sector GHG target for 2030 is tonnes eq or a reduction of 61–62% relative to 1990. The energy supply must be "almost completely decarbonised" by 2050, with renewables as its main source. For the electricity sector, "in the long-term, electricity generation must be based almost entirely on renewable energies" and "the share of wind and solar power in total electricity production will rise significantly".
If "possible and economically sensible", renewable energy will be used directly in all sectors, and electricity from renewable sources will be used efficiently for heating, transport, and industry. The utilization of biomass will be limited and sourced mostly from waste. The plan states that transitioning to a power supply based on renewables while ensuring supply security is "technically feasible". During the transition, "less carbon-intensive natural gas power plants and the existing most modern coal power plants play an important role as interim technologies".
The plan states that "the climate targets can only be reached if coal-fired power generation is reduced step-by-step". Moreover, the German government "in its development cooperation does not lend support to new coal power plants". Regions which depend on coal, like the Lausitz, need special consideration: "we must succeed in establishing concrete perspectives for the future of the affected regions, before concrete decisions on the step-by-step withdrawal from the lignite industry can be taken".
Notwithstanding, a coal phase-out for Germany is implied in the plan, environment minister Barbara Hendricks said in an interview on 21November 2016. "If you read the Climate Action Plan carefully, you will find that the exit from coal-fired power generation is the immanent consequence of the energy sector target.... By 2030... half of the coal-fired power production must have ended, compared to 2014", Hendricks said.
The plan also establishes a regional fund to foster new businesses in lignite mining regions. The government will need to ensure that EU competition law does not inhibit the operation of the fund.
Building sector
The building sector GHG target for 2030 is tonnes eq or a reduction of 66–67% relative to 1990. Under the plan, Germany's building stock will be largely carbon-neutral by 2050 and their limited energy needs will be met through renewables. Due to the slow turnover of buildings, the groundwork for this goal must be laid by 2030. The government will invest heavily in programs to implement high energy standards for buildings. Heating, cooling, and electricity supply will be progressively switched to renewables. The government will terminate support programs that rely on fossil fuels by 2020 and switch instead to support programs using renewable systems. The aim is to "make renewables-based systems much more attractive than fossil-fuel-based ones".
Transport sector
The transport sector GHG target for 2030 is tonnes eq or a reduction of 40–42% relative to 1990. Unlike earlier drafts, the plan does not now set a deadline for all new cars to be emissions free. Rather the plan states that stricter emissions limits for new cars will be set by the European Union and that "the government will advocate [an] ambitious development of the targets" so that its 2030-goal can be met. These cuts will derive from improved efficiencies and increasingly GHG-neutral energy. Such cuts will require "a significant contribution by the electrification of new cars and should have priority". The plan emphasizes the contribution that biofuels can make, stating that "in the target scenario, the energy supply of street and rail traffic, as well as parts of air and maritime traffic and inland shipping is switched to biofuels – if ecologically compatible – and otherwise largely to renewable electricity as well as other GHG-neutral fuels". The need to support public transport, rail transport, and cycling is stressed in the plan. The plan states a next step is to determine the framework needed to ensure that new powertrain technologies and energy forms will be adopted at scale. This then "involves the question of when, at the latest, they should be introduced into the market, and what penetration rate they should achieve by what date".
Industry
The industry GHG target for 2030 is tonnes eq or a reduction of 49–51% relative to 1990. Good progress has been made and, , the sector must reduce its emissions by about another 20%. Notwithstanding, the plan emphasizes the need to maintain international competitiveness:
The plan continues that, despite the costs and challenges, climate protection could become an "innovation motor" for a modern high-tech economy. The plan acknowledges that some industrial emissions cannot be avoided – for instance, those from steel production or chemical plants. Such emissions should be reduced as far as possible by developing new processes and replacing old ones – or through the use of carbon capture and utilization (CCU) or carbon capture and storage (CCS). The government will launch a research and development program to advance these and other low-carbon processes.
Agricultural sector
The agricultural sector GHG target for 2030 is tonnes eq or a reduction of 31–34% relative to 1990. The plan acknowledges that agriculture cannot reach zero emissions, due to the biological processes inherent in plant cultivation and livestock farming. Instead the plan will focus on reducing emissions as much as possible and on the more efficient use of resources. About one third of agricultural emissions are due to nitrous oxide from fertilizer use. The government wants to reduce these emissions through better management and through research and development. Another one third of emissions derive from ruminant animals. The government will develop a comprehensive strategy to reduce emissions from livestock farming by 2021. The plan states that 20% of agricultural land by 2030 "should be used for organic farming", compared with 6.3% in 2014. The government also advocates the use of financial instruments under a reformed EU Common Agricultural Policy to reduce GHG emissions from the sector."
Land use and forestry sector
The land use and forestry sector offers opportunities for carbon sequestration. The government will prioritize improving the performance of forests as carbon sinks. Sustainable forest management will also be promoted and permanent grasslands and marshes are to be preserved. The expansion of settlements and transport infrastructure is to be reduced to per day by 2020 and to zero by 2050.
Financial matters
Under the plan, the government will consider how to incrementally revise taxation through to 2050, on the understanding that "environmental taxes and levies can create incentives for ecological economic activity" and that "environmentally related taxes and levies can cost-efficiently trigger climate-friendly economic behavior". The government also intends to reduce environmentally harmful subsidies. In addition, the government will support efforts to reconcile global finance flows with climate protection goals, for instance through its role on the G20 Financial Stability Board.
Implementation and revision of the plan
The plan is predicated on a gradual transformation, achieved through a learning process involving the scientific community and accompanied by public dialogue. It is therefore intended that the plan can and should respond to changing technological, political, and social conditions. The plan will be reviewed every five years to align it with the evolution of Germany's nationally determined contribution (NDC) under the Paris Agreement. The first update is therefore slated for late 2019 or early 2020. As early as 2018, the government intends to strengthen the plan by quantifying the various emission reduction efforts and their associated ecological, social, and economic impacts. The sector targets may be modified as a result. Annual reporting should help the government to evaluate and adjust its specific climate protection measures in the short-term.
Reactions
Thilo Schaefer, climate and energy expert at the Cologne Institute for Economic Research (IW), comments that "it looks like the government forgot that the energy sector and industry already participate in the European emissions trading system... in the end, it will simply become more expensive for the affected sectors, but they won't save a single extra ton of ... because the emissions saved by German sectors can be emitted by other states".
Simone Peter, co-chair of the Green Party, said "this is not a good plan anymore, it has become an empty shell, because the ministerial colleagues of [environment minister] Hendricks have removed anything that could be of relevance – be it the coal exit, the end of the combustion engine, or a transition in agriculture".
Klaus Töpfer, founding director of the Institute for Advanced Sustainability Studies (IASS), said "this plan is certainly not yet capable of securing the German contribution to the Paris Climate Agreement. This will require more work".
Regine Günther, director of policy and climate at WWF Germany, said "today's climate action plan is only a fraction of what is needed. The only plus point: all sectors get precise reduction targets, which WWF welcomes. However, the list of negatives is much longer: there are no appropriate measures to reach those targets. There is also a blank on the issue of coal. The plan completely dropped the urgently needed ban on further extension of open cast mining. The commission on coal will not start until 2018, after the federal elections. A minimum price on carbon is also missing completely. With this plan, the industry and energy lobbies have proven how well placed they are in the economy ministry. With such a plan there can be no ambitious climate protection."
Ottmar Edenhofer, a German climate economist and director of the MCC, criticized the plan. He said economy and energy minister "Sigmar Gabriel yielded to lobbyists and sadly put short-term interests before long-term interests".
See also
Barbara Hendricks (SPD) – the environment minister during the development of the plan
Climate change mitigation – actions to limit climate change
Energiewende in Germany – the German energy system transition
German Federal Ministry for Economic Affairs and Energy (BMWi)
German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB)
Notes
References
External links
Climate Action Programme2020 – approved version dated 3December 2014 (this initiative preceded the Climate Action Plan2050)
Klimaschutzplan2050 — approved version dated 14November 2016 (in German)
Climate Action Plan2050 website (in German)
German 2050 Climate Action Plan (full document in English)
Climate Action Plan 2050 Executive Summary in English
Explanatory Film - The Climate Action Plan: Step-by-step to a liveable future. BMU. 11.12.2018. https://www.youtube.com/watch?v=WSJTKyDuI6I
Explanatory Film - The Climate Action Plan: Successful climate action has to be a cooperative undertaking. BMU. 11.12.2018. https://www.youtube.com/watch?v=_ZX4BXhmjMk
Explanatory Film - The Climate Action Plan: Moving together towards a bright future. BMU. 11.12.2018. https://www.youtube.com/watch?v=79FzzI920xg
Climate action plans
Climate change in Germany
Emissions reduction
Climate change policy
Coal phase-out
Energy in Germany
Energy policy of Germany
Renewable energy in Germany | German Climate Action Plan 2050 | [
"Chemistry"
] | 5,185 | [
"Greenhouse gases",
"Emissions reduction"
] |
51,629,229 | https://en.wikipedia.org/wiki/N6946-BH1 | N6946-BH1 is a disappearing supergiant star and failed supernova candidate formerly seen in the galaxy NGC 6946, on the northern border of the constellation of Cygnus. The star, either a red supergiant or a yellow hypergiant, was 25 times the mass of the Sun, and was 20 million light years distant from Earth. In March through to May 2009 its bolometric luminosity increased to at least a million solar luminosities, but by 2015 it had disappeared from optical view. In the mid and near infrared an object is still visible; however, it is fading away with a brightness proportional to t−4/3. The brightening was insufficient to be a supernova; the process that created the outburst is still uncertain.
The star's coordinates were at RA and Dec . The brightness of the star, given by its apparent magnitude in different colour bands on 2 July 2005 is given by R = 21, V = 22, B = 23, U = 24. Prior to the optical outburst the star was about 100,000 times as bright as the Sun. After the outburst it was invisible in the visual band and has declined to 5,000 times as bright as the Sun in infrared radiation.
One hypothesis is that of the failed supernova. In this scenario, the core of the star collapsed to form a black hole. The collapsing matter formed a burst of neutrinos that lowered the total mass of the star by a fraction of a percent. This caused a shock wave that blasted out the star's envelope to make it brighter. N6946-BH1 has supplied evidence contrary to the conventional idea that black holes are usually formed after a supernova, suggesting instead that a star may bypass this eventuality and yet collapse into a black hole.
Observed type II supernovae do not originate from stars with initial masses greater than about , and the rate of large star formation appears to exceed the rate of supernovae. The expectation is that something else is happening to these extra large stars. Failed supernovae and black hole formation is one proposed explanation. If this event indeed reflected the formation of a black hole, it is the first time that black hole formation has been observed.
Observations from the James Webb Space Telescope show that all observations before it were a combination of at least three objects. The data the instrument collected matches that of a merger of two stars; however, the failed supernova hypothesis cannot be ruled out.
Notes
References
External links
N6946-BH1 Giant Star Becomes a Black Hole Right Before Our Eyes!
Stars in NGC 6946
M-type supergiants
Astronomical objects discovered in 2015
Cygnus (constellation)
Extragalactic stars | N6946-BH1 | [
"Astronomy"
] | 558 | [
"Cygnus (constellation)",
"Constellations"
] |
51,630,164 | https://en.wikipedia.org/wiki/NGC%20228 | NGC 228 is a spiral galaxy located in the constellation Andromeda. It was discovered on October 10, 1879 by Édouard Stephan.
References
External links
0228
Barred spiral galaxies
Andromeda (constellation)
Discoveries by Édouard Stephan
002563 | NGC 228 | [
"Astronomy"
] | 50 | [
"Andromeda (constellation)",
"Constellations"
] |
51,630,178 | https://en.wikipedia.org/wiki/NGC%20229 | NGC 229 is a lenticular galaxy located in the constellation Andromeda. It was discovered on October 10, 1879, by Édouard Stephan.
References
External links
0229
Andromeda (constellation)
Lenticular galaxies
Discoveries by Édouard Stephan
002577 | NGC 229 | [
"Astronomy"
] | 52 | [
"Andromeda (constellation)",
"Constellations"
] |
51,630,259 | https://en.wikipedia.org/wiki/NGC%20230 | NGC 230 is a spiral galaxy located in the constellation Cetus. It was discovered in 1886 by Francis Leavenworth.
References
0230
Spiral galaxies
Cetus
002539 | NGC 230 | [
"Astronomy"
] | 36 | [
"Cetus",
"Constellations"
] |
51,630,292 | https://en.wikipedia.org/wiki/NGC%20231 | NGC 231 is an open cluster in the Small Magellanic Cloud. It is located in the constellation Tucana. It was discovered on August 1, 1826 by James Dunlop.
References
0231
Open clusters
Small Magellanic Cloud
Tucana | NGC 231 | [
"Astronomy"
] | 49 | [
"Tucana",
"Constellations"
] |
51,630,314 | https://en.wikipedia.org/wiki/NGC%20232 | NGC 232 is a spiral galaxy located in the constellation Cetus. It was discovered in 1886 by Francis Leavenworth.
References
External links
0232
Barred spiral galaxies
Cetus
002559 | NGC 232 | [
"Astronomy"
] | 39 | [
"Cetus",
"Constellations"
] |
51,630,337 | https://en.wikipedia.org/wiki/NGC%20233 | NGC 233 is an elliptical galaxy located in the constellation Andromeda. It was discovered on September 11, 1784 by William Herschel.
One supernova has been observed in NGC 233: SN2021abzd (typeIa-91bg-like, mag. 17.3).
See also
List of NGC objects (1–1000)
References
External links
0233
Elliptical galaxies
Andromeda (constellation)
002604
00464
+05-02-041
17840911
Discoveries by William Herschel | NGC 233 | [
"Astronomy"
] | 109 | [
"Andromeda (constellation)",
"Constellations"
] |
51,630,360 | https://en.wikipedia.org/wiki/NGC%20234 | NGC 234 is a spiral galaxy located in the constellation Pisces. It was discovered on October 14, 1784, by William Herschel.
One supernova has been observed in NGC 234: SN 2021abze (type II, mag. 16.6).
References
External links
0234
Intermediate spiral galaxies
Pisces (constellation)
002600 | NGC 234 | [
"Astronomy"
] | 73 | [
"Pisces (constellation)",
"Constellations"
] |
51,630,454 | https://en.wikipedia.org/wiki/Gan%20Ee%20Kiang | Gan Ee Kiang (born 23 June 1944) is a Malaysian pharmacologist. He is Professor of Pharmacology at the University of Science, Malaysia, and currently holds the honorary office of Chancellor of the International Medical University in Kuala Lumpur.
He joined the University of Science in 1977 and was Dean of School of Pharmaceutical Sciences from 1979 to 1995. He has also served as an adviser to the World Health Organization. From 1999 to 2013 he was Managing Director of the USAINS Group, the commercial arm of the University of Science. He is a member of the Board of Directors of several companies.
He earned a PhD in Pharmacology at the University of Western Australia in 1972 under the supervision of Mary Fauriel Lockett, the first female professor in Australia.
Honours
Pingat Kelakuan Terpuji (PKT, 1986), state award of Penang
Bintang Cemerlang Negeri (BCN, 1997), state award of Penang
Darjah Setia Pangkuan Negeri (DSPN, 2004), state award of Penang
Johan Mangku Negara (JMN, 1999), Malaysian federal award
References
Living people
Malaysian pharmacologists
1944 births
Academic staff of the International Medical University
Companions of the Order of the Defender of the Realm | Gan Ee Kiang | [
"Chemistry"
] | 263 | [
"Pharmacology",
"Pharmacology stubs",
"Medicinal chemistry stubs"
] |
51,631,063 | https://en.wikipedia.org/wiki/Failed%20supernova | A failed supernova is an astronomical event in time domain astronomy in which a star suddenly brightens as in the early stage of a supernova, but then does not increase to the massive flux of a supernova. They could be counted as a subcategory of supernova imposters. They have sometimes misleadingly been called unnovae.
Overview
Failed supernovae are thought to create stellar black holes by the collapsing of a red supergiant star in the early stages of a supernova. When the star can no longer support itself, the core collapses completely, forming a stellar-mass black hole, and consuming the nascent supernova without having the massive explosion. For a distant observer, the red supergiant star will seem to wink out of existence with little or no flare-up. The observed instances of these disappearances seem to involve supergiant stars with masses above 17 solar masses.
Failed supernovae are one of several events that theoretically signal the advent of a black hole born from an extremely massive star, others including hypernovae and long-duration gamma-ray bursts.
Structure and process
Theoretically, a red supergiant star may be too massive to explode into a supernova, and collapse directly into being a black hole, without the bright flash. They would however generate a burst of gravitational waves. This process would occur in the higher mass red supergiants, explaining the absence of observed supernovae with such progenitors.
List of failed supernovae candidates
References
External links
+
Astronomical events | Failed supernova | [
"Chemistry",
"Astronomy"
] | 311 | [
"Supernovae",
"Astronomical events",
"Explosions"
] |
51,631,696 | https://en.wikipedia.org/wiki/Project%20VR-190 | VR-190 (; Vysotnaya Raketa, literally, high-altitude rocket) was the USSR's first rocket project designed to launch a human into suborbital space flight on a ballistic trajectory. The project ran in the 1940s and 1950s and, according to official sources, did not achieve its set goals. However, conspiracy theories surrounding the project claim that although crewed flights officially failed, cosmonauts were successfully sent into space in the 1950s.
History
Origins
On 13 May 1946, according to a secret decree by the Soviet Government, large-scale rocket research was established in the USSR. The official establishment of the rocket industry was preceded by a working group run by Mikhail Tikhonravov and Nikolai Chernyshov at the NII-4 in the Academy of Artillery Science. In the autumn of 1945, the group ran its own stratospheric rocket programme, which culminated in the development of the VR-190, a rocket system for vertical flight for two pilots up to an altitude of 200 km based on captured German V-2 (A-4) rockets.
In February 1946, the project was presented to the Secretary of the USSR Academy of Sciences, N. G. Bruevich, and then to the Academy's president Sergey Vavilov in March. Positively received, the project was introduced to the Minister of the aviation industry, Mikhail Khrunichev, in June.
Testing and development
Testing of uncrewed and crewed flights was conducted at Kapustin Yar in the Astrakhan region. The test flights were reported to have lasted about 20 minutes during which the rocket reached a height of more than 100 km (Kármán line) in the upper atmosphere, with their payloads separating from the warheads. All pilots descended back using parachutes and landed a few kilometers from the launch site.
The VR-190 project was implemented at roughly same time, with high-altitude rockets with sealed warheads and life-support systems being tested. They also conducted flights with animal passengers in order to assess the combined effects of various factors that could also affect human passengers. Several suborbital flights with dogs were carried out: with R-1B and R-1V rockets (1951) - when dogs Dezik and Roma were the first animals in history to successfully complete sub-orbital spaceflight - with R-1D and R-1E rockets (1954-1957), R-1E rockets (1957-1960) and R-2A and R-5A rockets.
According to official accounts, the project never reached the stage of human flight, and was canceled due to the lack of success in the late 1950s. Work refocused on creating the orbital crewed capsule Vostok.
The project was strictly kept secret, with designers, scientists, and even the dogs operating under pseudonyms. The first public information on the project became available in the 1980s and was of a purely theoretical nature. Its practical implementation and the first flight of the dogs on rockets was officially disclosed in 1991.
See also
Point-to-point sub-orbital spaceflight
Orbital spaceflight
Spaceflight
Spaceport
List of rocket launch sites
Office of Commercial Space Transportation
Canadian Arrow
Supersonic Transport
XCOR Lynx
Rocketplane XP
DH-1 (rocket)
McDonnell Douglas DC-X
Interorbital Systems
Quad (rocket)
Lunar Lander Challenge
Reusable Vehicle Testing program by JAXA
Project Morpheus NASA program to continue developing ALHAT and Quad landers
References
Human spaceflight programs
Space program of the Soviet Union
Suborbital spaceflight | Project VR-190 | [
"Engineering"
] | 725 | [
"Space programs",
"Human spaceflight programs"
] |
51,635,031 | https://en.wikipedia.org/wiki/3-Nitrooxypropanol | 3-Nitrooxypropanol (abbreviated as 3-NOP or 3NOP) is a synthetic organic compound with the formula HOCH2CH2CH2ONO2. It is the mononitrate ester of 1,3-propanediol and acts as an enzyme inhibitor that specifically targets methyl coenzyme M reductase (MCR), the enzyme that catalyzes the final step of methanogenesis in microbes living in the digestive system of ruminants, such as cows and sheep.
When added to the feed of ruminant animals, it significantly lowers methane emissions by inhibiting the activity of MCR without being incorporated into milk or meat. It causes a slight increase in feed conversion without affecting raw yields. Studies have demonstrated that methane output is lowered by 30%.
Description
DSM has patented and commercialized 3-NOP as a methane inhibitor for production animals under the brand name Bovaer, a feed additive. The formulation consists of silicon dioxide (60% w/w), propylene glycol, and 3-nitrooxypropanol (10% w/w).
History
The development of Bovaer began in 2010 as part of the Clean Cow project initiated by DSM-Firmenich. This project aimed to address methane emissions from livestock, which are a major source of greenhouse gases. According to Maik Kindermann, head of research and development for the Bovaer project, the research commenced in 2008 with a focus on understanding the molecular mechanisms behind methane formation in ruminants.
The first successful trials were conducted in 2010 and over 40 trials were conducted to ensure efficacy and safety across different cattle diets and environments.
In 2021, Bovaer received its first approvals for use in Brazil and Chile, followed by authorization from the European Union for dairy cattle in 2022. The product was subsequently approved for use in Canada in early 2024 and received FDA approval for the U.S. market in May 2024.
In April 2022, Elanco was granted exclusive licensing rights to develop and commercialize Bovaer in the United States. In June 2023, Elanco requested a consultation with the U.S. FDA's Center for Veterinary Medicine regarding Bovaer's drug status for use as a methane inhibitor in dairy cows. On May 24, 2024, the U.S. FDA concluded that Bovaer can lower methane production when used as labeled and poses a low risk to animals and humans under its sale conditions.
Safety
The U.S. Food and Drug Administration (FDA) concluded that Bovaer meets safety and efficacy standards for use in lactating dairy cattle, stating that it does not negatively impact milk production or quality. Additionally, a scientific opinion by the European Food Safety Authority (EFSA) found that Bovaer is safe for dairy cows at the maximum recommended levels and poses no significant risk to consumer food safety or the environment.
3-NOP can be harmful if inhaled and is an irritant to the skin and eyes. Although concerns have been raised claiming a lack of long-term studies, three such studies do in fact exist as of November 2021 and were taken into account by the EFSA's regulatory analysis. Arla Foods has claimed that Bovaer will not affect milk quality or safety, as it does not transfer from cow to milk; this too is supported by the EFSA review.
3-NOP is metabolized very quickly into compounds that are naturally present in the rumen of cows.
Reception
In November 2024, Arla Foods announced a collaborative trial involving major UK retailers such as Morrisons, Tesco and Aldi to test Bovaer on approximately 30 farms in the UK.
Despite the potential benefits, the trial has faced significant backlash from consumers who have called for a boycott of Arla's products, particularly Lurpak butter. Critics have expressed concerns over the safety and ethical implications of using additives like Bovaer in livestock feed, with some consumers mistakenly believing that the additive is included in the milk itself.
Arla has defended the trial, asserting that Bovaer has been extensively tested and approved by regulatory bodies such as the European Food Safety Authority (EFSA) and the UK Food Standards Agency. The company insists that there will be no negative impact on animal health or milk quality during the trial. In response to these challenges, Arla is actively seeking government support to facilitate the adoption of sustainable practices among farmers, highlighting that financial assistance could play a crucial role in transitioning to greener methods.
Environmental impact
Bovaer aims to contribute to climate change mitigation by lowering enteric methane emissions from dairy cows. The feed additive, known scientifically as 3-nitrooxypropanol (3-NOP), has shown significant potential in reducing methane production in livestock. Studies indicate that feeding one tablespoon of Bovaer per lactating dairy cow per day can lead to a reduction of approximately 30% in methane emissions, which is equivalent to about 1.2 metric tons of carbon dioxide equivalent (CO2e) per cow annually.
A comprehensive study conducted in the Netherlands involving 150 dairy farms and over 20,000 cows demonstrated that Bovaer is more effective at higher dosages and when incorporated with corn in the cattle's diet. Additionally, trials in Italy reported methane reductions of up to 50% when Bovaer was administered daily to lactating cows. The European Food Safety Authority (EFSA) has concluded that Bovaer is safe for use in dairy cattle, with no significant adverse effects on milk production, composition, or animal health observed during trials. Furthermore, the product has been approved for use in over 55 countries, including Brazil, Chile, and Canada, reflecting its global acceptance and potential impact on reducing agricultural greenhouse gas emissions.
In addition to its environmental benefits, the use of Bovaer could provide financial incentives for farmers through participation in voluntary carbon markets and conservation programs, potentially yielding returns of $20 or more per lactating cow annually. According to Elanco’s VP of Livestock Sustainability, Katie Cook, about 50% of this return is expected to come from carbon marketplace participation through platforms like Athian or Truterra, which allows farmers to sell verified carbon credits generated by their methane reductions.
Moreover, government initiatives are also playing a crucial role. In the U.S., approximately $89 million in grants from the USDA’s Regional Conservation Partnership Program (RCPP) has been allocated to support dairy producers implementing technologies like Bovaer to reduce methane emissions. This funding not only incentivizes farmers to adopt sustainable practices but also helps create a robust market for carbon credits as demand for lower-carbon foods rises globally.
Effects on milk
Milk production and composition
While the primary focus of 3-NOP research has been on methane reduction, its effects on milk production metrics have also been studied. Some studies found that 3-NOP supplementation led to a tendency to decrease milk yield slightly, though this effect was not always observed. For instance, one study reported reductions in milk and energy-corrected milk (ECM) production by 12% and 9%, respectively, when cows were fed diets including 3-NOP. A meta-analysis found that increasing levels of 3-NOP led to higher concentrations of milk fat and protein without significantly affecting overall milk yield.
Feed efficiency
The introduction of 3-NOP has been associated with improved feed efficiency. Research indicates that cows supplemented with this compound exhibited better feed conversion rates, producing more milk fat or protein per unit of feed consumed. Specifically, feed efficiency improved by at least 4% across various studies.
Experimental studies indicate that 3-NOP is an effective feed additive for reducing methane emissions from dairy cows while maintaining or even enhancing certain aspects of milk production. Although some studies report a slight decrease in total milk yield, the increases in milk fat and protein concentrations suggest improved overall efficiency and quality of milk. The consistent findings across diverse trials support the potential for 3-NOP to play a significant role in sustainable dairy farming practices aimed at mitigating environmental impacts while optimizing production outcomes.
Emissions data
The use of 3-nitrooxypropanol has been studied as a method to reduce enteric methane emissions from dairy cows. Enteric methane, a potent greenhouse gas, is a significant contributor to agricultural emissions. Research indicates that the administration of 3-NOP can decrease methane emissions by approximately 30%, equivalent to a reduction of about 1.2 metric tons of carbon dioxide equivalent (CO2e) per cow annually.
3-NOP has demonstrated efficacy in reducing methane emissions from dairy cows. In a study conducted at Penn State University, the addition of 3-NOP to the diet resulted in a 26% reduction in daily methane emissions, with similar findings reported across various trials. The compound works by inhibiting an enzyme crucial for methane synthesis in the rumen, thereby decreasing methane production without negatively impacting feed intake or overall lactational performance.
A meta-analysis encompassing data from multiple studies confirmed that 3-NOP supplementation leads to a 24% decrease in enteric methane emissions, with no adverse effects on dry matter intake (DMI) or milk yield observed.
Society and culture
Conspiracy theory
In 2024, protests in the UK against the use of Bovaer have led some social media users to pour milk down sinks and toilets. A unfounded conspiracy theory circulated online, linking Bovaer to a supposed depopulation agenda involving Bill Gates. These unfounded claims have sparked backlash against Arla Foods, which is trialing Bovaer, and have prompted calls for product boycotts. Experts have clarified that Bovaer is safe and does not pose food safety risks, emphasizing that the claims linking Gates to Bovaer are false. Despite this, the conspiracy theories persist, complicating public acceptance of the additive and the potential benefits in combating climate change.
See also
FutureFeed – a algae-based feed additive that reduces methane emissions
Elanco
Sustainable agriculture
Carbon credits
Animal welfare
References
Enzyme inhibitors
Nitrate esters
Anaerobic digestion
Biodegradable waste management
Animal feed | 3-Nitrooxypropanol | [
"Chemistry",
"Engineering"
] | 2,086 | [
"Biodegradable waste management",
"Biodegradation",
"Anaerobic digestion",
"Environmental engineering",
"Water technology"
] |
68,734,019 | https://en.wikipedia.org/wiki/Humboldtine | Humboldtine is a rarely occurring mineral from the mineral class of "organic compounds" with the chemical composition FeC2O4•2H2O and is therefore a water-containing iron(II) oxalate or the iron salt of oxalic acid.
Humboldtine crystallizes in the monoclinic crystal system, but only rarely develops well-formed, tabular to prismatic crystals with a resin-like sheen on the surfaces. It is mostly found in the form of botryoidal or fibrous to earthy aggregates and crusty coatings from dull yellow to brownish yellow or amber yellow in color. It can be transparent to opaque. It can form from hematite in oxalic acid.
With a Mohs hardness of 1.5 to 2, humboldtine is one of the softest minerals and can be scratched with a fingernail.
Etymology and history
Humboldtine was first discovered by August Breithaupt in a weathered brown coal deposit near the municipality of Korozluky in Okres Most in the Czech Republic and described in 1821 by Mariano Eduardo de Rivero y Ustariz (1798-1857), who named the mineral after the German naturalist Alexander von Humboldt.
The mineral was already known and characterized when the IMA was founded (1959). Accordingly, humboldtine is listed as an officially recognized mineral.
Occurrence
The mineral is known to be found in 30 localities, including Germany, Brazil, the U.K. and Canada.
In 2023, during the digitization of the archive of the , a 75 year old letter from a coal mine owner written in 1949 was found. It mentioned that mineral was found in coal mine near the town of Schwandorf. Analysis of the mineral was done which confirmed the discovery. The discovery doubled the amount of Humboldtine known so far.
Crystal structure
Humboldtine crystallizes monoclinically in the space group C2/c (space group no. 15) with the lattice parameters a = 12.011 Å; b = 5.557 Å; c = 9.920 Å and β = 128.53°, with four formula units per unit cell.
Uses
It is an important synthetic intermediate and also a key building block for the preparation of various advanced materials.
References
Minerals
Organic minerals
Monoclinic minerals
Oxalate minerals
Iron(II) minerals
Minerals described in 1821 | Humboldtine | [
"Chemistry"
] | 486 | [
"Organic compounds",
"Organic minerals"
] |
68,735,447 | https://en.wikipedia.org/wiki/Machine%20learning%20in%20earth%20sciences | Applications of machine learning (ML) in earth sciences include geological mapping, gas leakage detection and geological feature identification. Machine learning is a subdiscipline of artificial intelligence aimed at developing programs that are able to classify, cluster, identify, and analyze vast and complex data sets without the need for explicit programming to do so. Earth science is the study of the origin, evolution, and future of the Earth. The earth's system can be subdivided into four major components including the solid earth, atmosphere, hydrosphere, and biosphere.
A variety of algorithms may be applied depending on the nature of the task. Some algorithms may perform significantly better than others for particular objectives. For example, convolutional neural networks (CNNs) are good at interpreting images, whilst more general neural networks may be used for soil classification, but can be more computationally expensive to train than alternatives such as support vector machines. The range of tasks to which ML (including deep learning) is applied has been ever-growing in recent decades, as has the development of other technologies such as unmanned aerial vehicles (UAVs), ultra-high resolution remote sensing technology, and high-performance computing. This has led to the availability of large high-quality datasets and more advanced algorithms.
Significance
Complexity of earth science
Problems in earth science are often complex. It is difficult to apply well-known and described mathematical models to the natural environment, therefore machine learning is commonly a better alternative for such non-linear problems. Ecological data are commonly non-linear and consist of higher-order interactions, and together with missing data, traditional statistics may underperform as unrealistic assumptions such as linearity are applied to the model. A number of researchers found that machine learning outperforms traditional statistical models in earth science, such as in characterizing forest canopy structure, predicting climate-induced range shifts, and delineating geologic facies. Characterizing forest canopy structure enables scientists to study vegetation response to climate change. Predicting climate-induced range shifts enable policy makers to adopt suitable conversation method to overcome the consequences of climate change. Delineating geologic facies helps geologists to understand the geology of an area, which is essential for the development and management of an area.
Inaccessible data
In Earth Sciences, some data are often difficult to access or collect, therefore inferring data from data that are easily available by machine learning method is desirable. For example, geological mapping in tropical rainforests is challenging because the thick vegetation cover and rock outcrops are poorly exposed. Applying remote sensing with machine learning approaches provides an alternative way for rapid mapping without the need of manually mapping in the unreachable areas.
Reduce time costs
Machine learning can also reduce the efforts done by experts, as manual tasks of classification and annotation etc are the bottlenecks in the workflow of the research of earth science. Geological mapping, especially in a vast, remote area is labour, cost and time-intensive with traditional methods. Incorporation of remote sensing and machine learning approaches can provide an alternative solution to eliminate some field mapping needs.
Consistent and bias-free
Consistency and bias-free is also an advantage of machine learning compared to manual works by humans. In research comparing the performance of human and machine learning in the identification of dinoflagellates, machine learning is found to be not as prone to systematic bias as humans. A recency effect that is present in humans is that the classification often biases towards the most recently recalled classes. In a labelling task of the research, if one kind of dinoflagellates occurs rarely in the samples, then expert ecologists commonly will not classify it correctly. The systematic bias strongly deteriorate the classification accuracies of humans.
Optimal machine learning algorithm
The extensive usage of machine learning in various fields has led to a wide range of algorithms of learning methods being applied. Choosing the optimal algorithm for a specific purpose can lead to a significant boost in accuracy: for example, the lithological mapping of gold-bearing granite-greenstone rocks in Hutti, India with AVIRIS-NG hyperspectral data, shows more than 10% difference in overall accuracy between using support vector machines (SVMs) and random forest.
Some algorithms can also reveal hidden important information: white box models are transparent models, the outputs of which can be easily explained, while black box models are the opposite. For example, although an SVM yielded the best result in landslide susceptibility assessment accuracy, the result cannot be rewritten in the form of expert rules that explain how and why an area was classified as that specific class. In contrast, decision trees are transparent and easily understood, and the user can observe and fix the bias if any is present in such models.
If computational resource is a concern, more computationally demanding learning methods such as deep neural networks are less preferred, despite the fact that they may outperform other algorithms, such as in soil classification.
Usage
Mapping
Geological or lithological mapping and mineral prospectivity mapping
Geological or lithological mapping produces maps showing geological features and geological units. Mineral prospectivity mapping utilizes a variety of datasets such as geological maps and aeromagnetic imagery to produce maps that are specialized for mineral exploration. Geological, lithological, and mineral prospectivity mapping can be carried out by processing data with ML techniques, with the input of spectral imagery obtained from remote sensing and geophysical data. Spectral imaging is also used – the imaging of wavelength bands in the electromagnetic spectrum, while conventional imaging captures three wavelength bands (red, green, blue) in the electromagnetic spectrum.
Random forests and SVMs are some algorithms commonly used with remotely-sensed geophysical data, while Simple Linear Iterative Clustering-Convolutional Neural Network (SLIC-CNN) and Convolutional Neural Networks (CNNs) are commonly applied to aerial imagery. Large scale mapping can be carried out with geophysical data from airborne and satellite remote sensing geophysical data, and smaller-scale mapping can be carried out with images from Unmanned Aerial Vehicles (UAVs) for higher resolution.
Vegetation cover is one of the major obstacles for geological mapping with remote sensing, as reported in various research, both in large-scale and small-scale mapping. Vegetation affects the quality of spectral images, or obscures the rock information in aerial images.
Landslide susceptibility and hazard mapping
Landslide susceptibility refers to the probability of landslide of a certain geographical location, which is dependent on local terrain conditions. Landslide susceptibility mapping can highlight areas prone to landslide risks, which is useful for urban planning and disaster management. Such datasets for ML algorithms usually include topographic information, lithological information, satellite images, etc., and some may include land use, land cover, drainage information, and vegetation cover according to the study requirements. As usual, for training an ML model for landslide susceptibility mapping, training and testing datasets are required. There are two methods of allocating datasets for training and testing: one is to randomly split the study area for the datasets; another is to split the whole study into two adjacent parts for the two datasets. To test classification models, the common practice is to split the study area randomly; however, it is more useful if the study area can be split into two adjacent parts so that an automation algorithm can carry out mapping of a new area with the input of expert-processed data of adjacent land.
Feature identification and detection
Discontinuity analyses
Discontinuities such as fault planes and bedding planes have important implications in civil engineering. Rock fractures can be recognized automatically by machine learning through photogrammetric analysis, even with the presence of interfering objects such as vegetation. In ML training for classifying images, data augmentation is a common practice to avoid overfitting and increase the training dataset size and variability. For example, in a study of rock fracture recognition, 68 images for training and 23 images for testing were prepared via random splitting. Data augmentation was performed, increasing the training dataset size to 8704 images by flipping and random cropping. The approach was able to recognize rock fractures accurately in most cases. Both the negative prediction value (NPV) and the specificity were over 0.99. This demonstrated the robustness of discontinuity analyses with machine learning.
Carbon dioxide leakage detection
Quantifying carbon dioxide leakage from a geological sequestration site has gained increased attention as the public is interested in whether carbon dioxide is stored underground safely and effectively. Carbon dioxide leakage from a geological sequestration site can be detected indirectly with the aid of remote sensing and an unsupervised clustering algorithm such as Iterative Self-Organizing Data Analysis Technique (ISODATA). The increase in soil CO2 concentration causes a stress response for plants by inhibiting plant respiration, as oxygen is displaced by carbon dioxide. The vegetation stress signal can be detected with the Normalized Difference Red Edge Index (NDRE). The hyperspectral images are processed by the unsupervised algorithm, clustering pixels with similar plant responses. The hyperspectral information in areas with known CO2 leakage is extracted so that areas with leakage can be matched with the clustered pixels with spectral anomalies. Although the approach can identify CO2 leakage efficiently, there are some limitations that require further study. The NDRE may not be accurate due to reasons like higher chlorophyll absorption, variation in vegetation, and shadowing effects; therefore, some stressed pixels can be incorrectly classed as healthy. Seasonality, groundwater table height may also affect the stress response to CO2 of the vegetation.
Quantification of water inflow
The rock mass rating (RMR) system is a widely adopted rock mass classification system by geomechanical means with the input of six parameters. The amount of water inflow is one of the inputs of the classification scheme, representing the groundwater condition. Quantification of the water inflow in the faces of a rock tunnel was traditionally carried out by visual observation in the field, which is labour and time consuming, and fraught with safety concerns. Machine learning can determine water inflow by analyzing images taken on the construction site. The classification of the approach mostly follows the RMR system, but combining damp and wet states, as it is difficult to distinguish only by visual inspection. The images were classified into the non-damaged state, wet state, dripping state, flowing state, and gushing state. The accuracy of classifying the images was approximately 90%.
Classification
Soil classification
The most popular cost-effective method od soil investigation method is cone penetration testing (CPT). The test is carried out by pushing a metallic cone through the soil: the force required to push at a constant rate is recorded as a quasi-continuous log. Machine learning can classify soil with the input of CPT data. In an attempt to classify with ML, there are two tasks required to analyze the data, namely segmentation and classification. Segmentation can be carried out with the Constraint Clustering and Classification (CONCC) algorithm to split a single series data into segments. Classification can then be carried out by algorithms such as decision trees, SVMs, or neural networks.
Geological structure classification
Exposed geological structures such as anticlines, ripple marks, and xenoliths can be identified automatically with deep learning models. Research has demonstrated that three-layer CNNs and transfer learning have strong accuracy (about 80% and 90% respectively), while others like k-nearest neighbors (k-NN), regular neural nets, and extreme gradient boosting (XGBoost) have low accuracies (ranging from 10% - 30%). The grayscale images and colour images were both tested, with the accuracy difference being little, implying that colour is not very important in identifying geological structures.
Forecast and predictions
Earthquake early warning systems and forecasting
Earthquake warning systems are often vulnerable to local impulsive noise, therefore giving out false alerts. False alerts can be eliminated by discriminating the earthquake waveforms from noise signals with the aid of ML methods. The method consists of two parts, the first being unsupervised learning with a generative adversarial network (GAN) to learn and extract features of first-arrival P-waves, and the second being use of a random forest to discriminate P-waves. This approach achieved 99.2% in recognizing P-waves, and can avoid false triggers by noise signals with 98.4% accuracy.
Earthquakes can be produced in a laboratory settings to mimic real-world ones. With the help of machine learning, the patterns of acoustic signals as precursors for earthquakes can be identified. Predicting the time remaining before failure was demonstrated in a study with continuous acoustic time series data recorded from a fault. The algorithm applied was a random forest, trained with a set of slip events, performing strongly in predicting the time to failure. It identified acoustic signals to predict failures, with one of them being previously unidentified. Although this laboratory earthquake is not as complex as a natural one, progress was made that guides future earthquake prediction work.
Streamflow discharge prediction
Real-time streamflow data is integral for decision making (e.g., evacuations, or regulation of reservoir water levels during flooding). Streamflow data can be estimated by data provided by stream gauges, which measure the water level of a river. However, water and debris from flooding may damage stream gauges, resulting in lack of essential real-time data. The ability of machine learning to infer missing data enables it to predict streamflow with both historical stream gauge data and real-time data.
Streamflow Hydrology Estimate using Machine Learning (SHEM) is a model that can serve this purpose. To verify its accuracies, the prediction result was compared with the actual recorded data, and the accuracies were found to be between 0.78 to 0.99.
Challenge
Inadequate training data
An adequate amount of training and validation data is required for machine learning. However, some very useful products like satellite remote sensing data only have decades of data since the 1970s. If one is interested in the yearly data, then only less than 50 samples are available. Such amount of data may not be adequate. In a study of automatic classification of geological structures, the weakness of the model is the small training dataset, even though with the help of data augmentation to increase the size of the dataset. Another study of predicting streamflow found that the accuracies depend on the availability of sufficient historical data, therefore sufficient training data determine the performance of machine learning. Inadequate training data may lead to a problem called overfitting. Overfitting causes inaccuracies in machine learning as the model learns about the noise and undesired details.
Limited by data input
Machine learning cannot carry out some of the tasks as a human does easily. For example, in the quantification of water inflow in rock tunnel faces by images for Rock Mass Rating system (RMR), the damp and the wet state was not classified by machine learning because discriminating the two only by visual inspection is not possible. In some tasks, machine learning may not able to fully substitute manual work by a human.
Black-box operation
In many machine learning algorithms, for example, Artificial Neural Network (ANN), it is considered as 'black box' approach as clear relationships and descriptions of how the results are generated in the hidden layers are unknown. 'White-box' approach such as decision tree can reveal the algorithm details to the users. If one wants to investigate the relationships, such 'black-box' approaches are not suitable. However, the performances of 'black-box' algorithms are usually better.
References
Machine learning
Geological techniques | Machine learning in earth sciences | [
"Engineering"
] | 3,220 | [
"Artificial intelligence engineering",
"Machine learning"
] |
68,735,824 | https://en.wikipedia.org/wiki/CARE%20Principles%20for%20Indigenous%20Data%20Governance | The CARE Principles for Indigenous Data Governance are a set of principles intended to guide open data projects in engaging Indigenous Peoples rights and interests. CARE was created in 2019 by the International Indigenous Data Sovereignty Interest Group, a group that is a part of the Research Data Alliance. It outlines collective rights related to open data in the context of the United Nations Declaration on the Rights of Indigenous Peoples and Indigenous data sovereignty.
CARE is an acronym which stands for Collective Benefit, Authority to Control, Responsibility, Ethics. The CARE Principles are 'people and purpose-oriented, reflecting the crucial role of data in advancing Indigenous innovation and self-determination', and intended as a complement to the data-oriented perspective of other standards such as FAIR data (findable, accessible, interoperable, reusable).
The CARE principles have been embedded into the Beta version of Standardised Data on Initiatives (STARDIT). CARE principles were the basis of a submission to the UN's Global Digital Compact.
See also
FAIR data
First Nations principles of OCAP
Data sovereignty
Indigenous data governance
References
External links
CARE Principles for Indigenous Data Governance (including links to PDFs of full description and short summaries)
Data management
Indigenous rights | CARE Principles for Indigenous Data Governance | [
"Technology"
] | 240 | [
"Data management",
"Data"
] |
68,737,576 | https://en.wikipedia.org/wiki/Amateur%20astronaut | An amateur astronaut is an untrained person participating in a spaceflight. The term is widely used by SpaceX and others, and by widespread media, especially after the launch of Inspiration4, crewed by 4 untrained humans, on a 3-day flight around the Earth.
List of Amateur astronauts
Christopher Sembroski (Inspiration4, 16 September 2021 – 18 September 2021)
Sian Proctor (Inspiration4, 16 September 2021 – 18 September 2021)
Jared Isaacman (Inspiration4, 16 September 2021 – 18 September 2021), (Polaris Dawn, 10 September 2024 –)
Hayley Arceneaux (Inspiration4, 16 September 2021 – 18 September 2021)
Scott Poteet (Polaris Dawn, 10 September 2024 –)
Sarah Gillis (Polaris Dawn, 10 September 2024 –)
Anna Menon (Polaris Dawn, 10 September 2024 –)
References
External links
Matt Watts. SpaceX launches world’s first ‘amateur astronaut’ crew to orbit Earth. Evening Standard, 16 September 2021
Highlights From the SpaceX Inspiration4 Astronauts’ Splashdown. The New York Times, 18 September 2021
Spaceflight | Amateur astronaut | [
"Astronomy"
] | 231 | [
"Spaceflight",
"Outer space"
] |
68,738,451 | https://en.wikipedia.org/wiki/James%20Bond%20007%3A%20Everything%20or%20Nothing%20%28GBA%20video%20game%29 | James Bond 007: Everything or Nothing is a third-person shooter video game, developed by Griptonite Games and published by Electronic Arts for the Game Boy Advance (GBA). As MI6 agent James Bond, the player must foil an ex-KGB agent who plans to use nanotechnology for world domination.
Everything or Nothing was released in November 2003, several months prior to the release of a home console version. It received "mixed or average" reviews according to Metacritic.
Gameplay
Everything or Nothing is primarily a third-person shooter, played from an isometric perspective. The player controls MI6 agent James Bond. Stealth is emphasized throughout the game, and several driving levels are also featured.
The game is divided into eight missions set around the world. On foot, the player has various weapons and gadgets to use against guard enemies who appear throughout the game. Weapons include guns, grenades, and land mines, and the player can also punch or kick. Medical kits are found throughout the game and are used to replenish the player's health. The player can take cover behind pillars or tables and can rappel down cliffs and buildings on some levels.
M and Q appear after each level to brief the player. In each level, primary objectives must be completed before advancing. Optional secondary objectives are also present in each level, providing the player with Style Points if completed. At the end of each level, the player can use the accumulated Style Points to purchase armor, weapon upgrades, increased speed, and better aiming. A blackjack mini-game can also be unlocked by collecting Style Points. The player can sneak up on guards from behind and quietly take them out for additional points. A radar is used to detect enemy locations, and an alert meter tells the player whether they have been spotted.
The driving portions are played during certain missions and are also viewed from an isometric perspective. The player pursues a primary enemy vehicle and is also followed by several smaller enemy vehicles. The player's car has several weapons such as a machine gun, rockets, and oil slicks.
The game offers a multiplayer deathmatch mode for up to four players, with the use of a Game Link Cable. A GameCube – Game Boy Advance link cable can also be used to connect with the GameCube version of Everything or Nothing, unlocking mini-games and upgraded gadgets, among other features.
Plot
The game opens in the Sahara Desert in Egypt, where James Bond infiltrates and destroys a secret weapons facility. He is then sent to a casino in Cairo, to investigate Arkady Yayakov, an ex-KGB agent and suspected smuggler. It is believed that Yayakov knows about recently stolen nanotechnology. Bond pursues Yayakov in a car chase, and his investigation leads him to a Cairo train yard that Yayakov had used as a shipping base. Bond discovers traces of the nanotechnology and also encounters a former foe, Jaws, whom he defeats in a battle.
MI6 learns that one of Yayakov's clients is an ex-KGB agent named Nikolai Diavolo, who has set up a base in the Peruvian jungle near a platinum mine. Bond meets with Agent 003, who has monitored the base, and they infiltrate the site. 003 is killed, and Bond pursues Diavolo in a car chase. He learns of another compound, hidden within a crypt in New Orleans. There, he discovers Diavolo is working with scientist Dr. Katya Nadanova. She has used a biological agent found in Louisiana to create nanobots that are capable of eating through metals, except platinum. Diavolo plans to unleash an army of platinum-coated super soldiers on the world while using the nanobots to destroy military defenses such as warships and tanks. He plans to initiate his plot in Moscow and intends to launch nanotech missiles to destroy cities unless his demands are met.
Bond escapes the New Orleans facility, and American agent Mya Starling is sent to destroy Diavolo's nanotech plant, located at the Andes Mountains in Peru. Bond is sent there after she goes missing, and he proceeds through the large facility, which extends underground through Incan ruins. Starling escapes, the facility is destroyed, and Bond travels to Moscow to foil Diavolo's plot. He pursues Nadanova's tank stops her, and subsequently fights against Jaws in another battle, before ultimately killing Diavolo.
Development and release
Everything or Nothing was developed by Griptonite Games. The game features the likenesses of Pierce Brosnan (James Bond), Judi Dench (M), Willem Dafoe (Nikolai Diavolo), Heidi Klum (Katya Nadanova), and Mýa (Mya Starling). Mýa also sings the game's eponymous song, heard during the end credits. The actors also provide minimal voice-over lines. Everything or Nothing was published by Electronic Arts for Game Boy Advance. In North America, it was released on November 17, 2003, several months before the home console version.
Reception
Everything or Nothing received "mixed or average" reviews according to Metacritic. Critics generally found the game to be too short, with little replay value.
Frank Provo of GameSpot stated that the game adequately captured "the look and feel of a typical Bond film", and Justin Speer of X-Play said the game has an "authentic Bond feel". The on-foot gameplay was compared to Metal Gear Solid for the Game Boy Color. Matt Helgeson, writing for Game Informer, was critical of the isometric perspective: "It's sort of hard to plan your next move when you can only see about 10 virtual feet in front of you, and as a result it's usually easier to just run and gun your way through the levels".
GameSpy's Avi Fryman considered the game's environments to be "severely limited", writing, "There are few nooks and crannies to explore, few secrets to reveal, and few genuinely interactive objects". Eduardo Zacarias of GameZone criticized the sluggish movements and the difficulty in aiming, and found the game somewhat repetitive. Other critics praised the gameplay. Nintendojo called the amount of variety "very admirable in today's heavily congested Game Boy Advance market".
The driving portions were considered reminiscent of Spy Hunter, with some negative comparisons by critics. Greg Orlando of GMR called the driving portions "unwieldy and dull", and Speer also criticized the poor handling. Fryman found this component of the game "not quite as fun or involved" as Spy Hunter. Conversely, Zacarias praised the driving portions and considered them "highly addictive".
The sound and music were praised. Craig Harris of IGN opined that the audio is "where the game really shines", writing that the soundtrack is "outstanding" and "sets the mood perfectly". GamePro wrote that the soundtrack "really brings out the exhilaration of the espionage action". The graphics also received some praise.
Notes
References
External links
James Bond 007: Everything or Nothing at MobyGames
2003 video games
James Bond video games
Electronic Arts games
Game Boy Advance games
Stealth video games
Third-person shooters
Fiction about nanotechnology
Video games set in Egypt
Video games set in New Orleans
Video games set in Peru
Video games set in Moscow
Griptonite Games
Video games developed in the United States
Games with GameCube-GBA connectivity | James Bond 007: Everything or Nothing (GBA video game) | [
"Materials_science"
] | 1,534 | [
"Fiction about nanotechnology",
"Nanotechnology"
] |
68,739,969 | https://en.wikipedia.org/wiki/Orca%20%28carbon%20capture%20plant%29 | The Orca carbon capture plant is a facility that uses direct air capture to remove carbon dioxide from the atmosphere (The name, "Orca" comes from the Icelandic word, "orka" which means "energy". It was constructed by Climeworks and is joint work with Carbfix, an academic-industrial partnership that has developed a novel approach to capture . The plant uses dozens of large fans to pull in air and pass it through a filter. The filter is then released of the it contains through heat. The extracted is later mixed with water and pushed into the ground, using a technology from Carbfix.
The plant started sequestering carbon dioxide in 2021. It is said to have cost between $10–15 million to build. It is located in Iceland and is the largest facility of its kind on earth. It is located about 50 kilometers outside Reykjavík next to the Hellisheiði Power Station, which is run by Reykjavík Energy. It was inaugurated on 8 September 2021 in presence of Katrín Jakobsdóttir, the Prime Minister of Iceland.
Carbon offsetting potential
Climeworks claims that the plant can capture 4000 tons of per year. This equates roughly to the emissions from about 870 cars. It counts Microsoft founder Bill Gates and the reinsurance company Swiss Re as current customers.
The thousands of tons of carbon dioxide being removed is owed to the nearly 20 direct air capture plants currently functioning in the world. As the world's climate climbs towards 2 degrees Celsius, more technology is needed desperately to sustain our climate, preventing it from reaching severe temperatures.
References
Carbon capture and storage
Buildings and structures in Iceland | Orca (carbon capture plant) | [
"Engineering"
] | 334 | [
"Geoengineering",
"Carbon capture and storage"
] |
68,741,924 | https://en.wikipedia.org/wiki/Chemistry%20and%20Non-Metallic%20Industry%20Workers%27%20Union | The Chemistry and Non-Metallic Industry Workers' Union () was a trade union representing workers in various industries in Yugoslavia.
The union was founded in 1974, when the Union of Industrial and Mining Workers was split up. Like its predecessor, it affiliated to the Confederation of Trade Unions of Yugoslavia. By 1990, it had grown to 255,000 members and was led by Stojmir Domazetovski. That year, it split into various more localised unions.
References
Chemical industry trade unions
Trade unions established in 1974
Trade unions disestablished in 1990
Trade unions in Yugoslavia | Chemistry and Non-Metallic Industry Workers' Union | [
"Chemistry"
] | 117 | [
"Chemical industry trade unions"
] |
68,743,168 | https://en.wikipedia.org/wiki/Were%20You%20Raised%20By%20Wolves%3F | Were You Raised By Wolves? is an independent podcast about etiquette and manners hosted by Nick Leighton and Leah Bonnema, which debuted on September 9, 2019. The podcast features Leighton and Bonnema exploring various historical and contemporary etiquette topics and answering questions sent in by listeners.
Content
The format of a typical episode involves six segments, each focusing on a different aspect of etiquette and manners: "Amuse-bouche" (a short explanation of a clear etiquette rule, such as "How to eat a croissant"), "A Question of Etiquette" (a longer discussion on a broader etiquette topic or theme, such as "Ghosting"), "Questions from the Wilderness" (listener-submitted questions), "Vent or Repent" (the hosts share personal anecdotes about etiquette in their own lives), "What Have We Learned?" (the hosts say one thing they've learned during the episode), and "Cordials of Kindness" (the hosts share something they're thankful for). With the exception of the first episode, the show does not include any guests or interviews.
Reception
Nick Leighton has answered questions about etiquette on USA Today and the Washington Post. The podcast has been mentioned by the New York Times, The A.V. Club, and the New Zealand Herald.
Awards
The show was a 2021 Webby Awards Honoree in the Arts & Culture category and a finalist for the 2021 Podcast Awards in the Society & Culture category. In 2022, the show is a Webby Awards Nominee in the "Podcasts - Best Co Hosts" and "Podcasts - Best Advice & How To" categories.
Episodes
Episodes are released weekly, on Mondays. As of August 20, 2021, the podcast had aired 100 episodes.
References
External links
Audio podcasts
Comedy podcasts
2019 podcast debuts
Advice podcasts
Works about interpersonal relationships
American podcasts
Independent podcasts | Were You Raised By Wolves? | [
"Biology"
] | 400 | [
"Behavior",
"Works about interpersonal relationships",
"Works about behavior"
] |
68,743,478 | https://en.wikipedia.org/wiki/Tega%20Brain | Tega Brain is an Australian-born digital artist and environmental engineer who is also an assistant professor of Integrated Digital Media at New York University (NYU). Brain is known for her eccentric and often purposefully dysfunctional information systems that examine the intersection between digital networks and natural phenomena. Her art works have been discussed widely in press outlets such as The New York Times, The Atlantic, Artforum, NPR and The Guardian. Brain's works have been exhibited in multiple museums such as the Whitney Museum of American Art and the Haus der Kulturen der Welt in Berlin. In 2021, Brain co-authored the textbook Code as Creative Medium which serves as a guide for educators and computer scientists about teaching and learning computational art and design.
Education
Brain received a Bachelor of Environmental Engineering and a Bachelor of Arts at University of New South Wales in 2006. She then completed a Masters of Art at the Queensland University of Technology in 2012.
Notable works
In 2015, in response to the decision by John Hancock Insurance to offer discounts if members shared their personal fitness data as logged by a Fitbit, Brain, alongside engineer Surya Mattu, created the website Unfit-Bits. The website offers solutions to spoof fitness data, to "produce data to qualify [users] for incentives from employers or insurers, even if they can't afford a high exercise lifestyle". This work was part of the exhibition, "24/7: A Wake Up Call for Our Non-Stop World" in 2019.
In 2020 she created the work, "New York Apartment", with collaborator Sam Lavigne. This work aggregates all New York City real-estate listings and presents them as a fictional massive apartment. Again in 2020, the pair collaborated on a website titled "Get Well Soon!", which archives over 20,000 comments from GoFundMe campaigns and lists them in alphabetical order. The New York Times described the piece as an "archive of well-wishes and fears, prayers and pleadings, represent a slice of the grief, love, medical costs and mutual aid that define illness in this country."
References
External links
Unfit Bits, 2020
New York Apartment, 2020
Get Well Soon!, 2020
Living people
Year of birth missing (living people)
University of New South Wales alumni
Queensland University of Technology alumni
21st-century Australian women artists
Environmental engineers | Tega Brain | [
"Chemistry",
"Engineering"
] | 478 | [
"Environmental engineers",
"Environmental engineering"
] |
68,744,375 | https://en.wikipedia.org/wiki/Silanide | A silanide is a chemical compound containing an anionic silicon(IV) centre, the parent ion being . The hydrogen atoms can also be substituted to produce more complex derivative anions such as tris(trimethylsilyl)silanide (hypersilyl), tris(tert-butyl)silanide, tris(pentafluoroethyl)silanide, or triphenylsilanide. The simple silanide ion can also be called trihydridosilanide or silyl hydride.
Formation
The simplest trihydridosilanides can be produced from a triphenylsilanide in a reaction with hydrogen or at standard conditions. The triphenylsilanide can be made in a reaction of Ph3SiSiMe3 with the metal tert-butoxy compound.
Reacting hydrogen with potassium triphenylsilyl can yield potassium silanide.
Other method to form silanides are to heat a heavy metal silicide with hydrogen, or react the dissolved metal with silane.
Atomic metals can react directly with silane to yield unstable molecules with formulae. These can be condensed into a noble gas matrix. With titanium this also yields molecules with hydrogen bridging between silicon and titanium.
Properties
The silanide ion has an effective ionic radius of 2.26 Å. In salts at room temperature the ion's orientation is not stable, and it rotates. But at lower temperatures (under 200K) silanide becomes fixed in orientation. The ordered structure forms the β- phase, whereas the higher temperature and more symmetrical disordered structure is called α- phase. The β- phase is about 15% more compact than the α-phase.
The silanide ion has C3v symmetry. The silicon to hydrogen bond length is 1.52 Å and the H-Si-H bond angle is 92.2°, not far off a right angle. In a range of compounds, the stretching force constant for the Si-H bond is 1.9 to 2.05 N cm–1, which is much softer than that of silane's 2.77 N cm–1.
Silanide salts are very easily damaged by air or water.
Heating to under 414K results in the release of hydrogen and the formation of a Zintl-phase MSi. If an alkali silande is rapidly heated to 500K another irreversible reaction occurs:
.
Use
Trihydridosilanides have been investigated as hydrogen storage materials. Potassium silanide can reversibly gain or lose hydrogen over several hours at 373K. However this does not work for sodium silanide. The rate of hydrogen exchange may be improved by a catalyst. Unwanted reactions may reduce the number of times this process can happen.
List
Related
Under high hydrogen pressure, pentacoordinated and hexacoordinated silicon hydride ions are stabilised including and .
More complex derivatives include silanimine -,
With a double bond between silicon and the metal a silylene complex is formed. With a triple bond, M≡SiH forms with metals such as molybdenum and tungsten.
With less hydrogen, a polyanionic hydride [(SiH)−] can be formed.
General organic compounds are termed silylium ions.
References
Silanes
Anions | Silanide | [
"Physics",
"Chemistry"
] | 702 | [
"Ions",
"Matter",
"Anions"
] |
68,746,201 | https://en.wikipedia.org/wiki/Forbes%20Log | The Forbes Log is an instrument for measuring the speed and distance traveled by ships, notably those of the Royal Navy. They were introduced commercially by Elliott Brothers in 1909 and were fitted to all capital ships by 1912, generally to aid the use of the dumaresq as well as battle reporting.
History
Elliott Brothers licensed the concept and began production in 1909. It was a standard fit to all capital ships by 1912. The company also licensed the device to Anschütz in 1911, in exchange for a license of Anschütz's gyrocompass technology. The Anschütz compass proved less accurate and less reliable than models introduced in 1913 by Sperry Gyroscope, and the Anschütz models produced by Elliot were replaced with Sperrys.
Initial tests of the Forbes Log in 1912 demonstrated it was not entirely accurate, which added to a larger set of problems being encountered by the Navy's new gunlaying instruments. These issues were eventually solved, and the Forbes Log remained a standard solution well into World War II, by which time they were found on almost all British and allied ships, including submarines.
One of the remote outputs of the Forbes Log was placed in the gunnery control rooms where they were initially used to set the dumaresq and range clocks by their respective operators; in the post World War I-era, the system was often automated, eliminating the need for an operator to do this.
Description
The measuring system of the Forbes Log consists of an L-shaped tube that projects through the hull with the bottom portion of the L facing forward. The ship's forward motion forces water into the tube where it spins a propeller and then exits through a second pipe facing aft. The propeller is connected to a small generator, whose electrical signal is then sent to the Log itself. This consists of a voltmeter pointer indicating the instantaneous speed, and an odometer-like system recording elapsed distance.
The advantage to the Forbes Log is that the signal can be amplified and sent anywhere in the ship. This made it valuable on large Navy ships where the information was being used by many different parts of the crew. In typical use, the main log would be repeated on the bridge and combat center, with additional speed-only indicators sent to the fire control office and turrets to aid gunlaying.
References
Citations
Bibliography
Military computers
Mechanical computers
Analog computers
Naval artillery | Forbes Log | [
"Physics",
"Technology"
] | 484 | [
"Physical systems",
"Machines",
"Mechanical computers"
] |
75,990,812 | https://en.wikipedia.org/wiki/ADX-71441 | ADX-71441 is a GABAB receptor positive allosteric modulator currently being investigated as a potential treatment for anxiety, epilepsy, pain and other conditions.
Therapeutic potential
Addiction
ADX-71441 has been shown to reduce alcohol consumption. This result was observed in both alcohol dependent and non-dependent animals.
There were also trials about nicotine addiction, which showed positive results: ADX-71441 was able to decrease some withdrawal symptoms of nicotine withdrawal.
Anxiety
This compound has also been shown to reduce anxiety in people with PTSD.
Pain
Experiments have shown that this compound was able to decrease hypersensitivity to pain in mice, Guinea pigs and rats.
Tolerance
ADX-71441 has been shown to have less tolerance and side effects than direct GABAB agonists, such as baclofen.
References
GABA receptor ligands
Fluoroarenes
Acetamides
Methoxy compounds
Triazines
Chloroarenes
Ureas | ADX-71441 | [
"Chemistry"
] | 204 | [
"Organic compounds",
"Ureas"
] |
75,991,369 | https://en.wikipedia.org/wiki/H%C3%B4tel%20de%20Vend%C3%B4me%20%28boulevard%20Saint-Michel%2C%20Paris%29 | The Hôtel de Vendôme is a private mansion in the 6th arrondissement of Paris.
History
The Hôtel de Vendôme was built in 1707 by the architect Jean-Baptiste Alexandre Le Blond, rue d'Enfer (today boulevard Saint-Michel) for the Carthusian canon Antoine de La Porte. The plans were published by Augustin-Charles d'Aviler in 1710 in his Cours d'architecture under the title "Hôtel scis rue d'Enfer in Paris, occupied by M. le duc de Chaulnes et Batie on the designs of Sr le Blond".
Leased to the Duchess of Vendôme, the hotel was remodeled in 1715-1716 by the same architect, who modified the facade overlooking the garden and created a new avant-corps with the pediment of the old one.
In the middle of the 18th century, it was occupied, following a long lease, by the 5th Duke of Chaulnes, Michel Ferdinand d'Albert d'Ailly, who died there in 1769, and his wife. The duke kept part of his important library there also conducting scientific experiments there. Their son, the 6th Duke of Chaulnes, continued the lease, but did not live in the hotel. He sublet it until the Revolution and died in 1792. The hotel was then confiscated.
Adjoining the Luxembourg Gardens, onto which its rear façade overlooks, it has been the headquarters of the Mines Paris – PSL since 1815. It also houses the Musée de Minéralogie.
In the 19th century, it was expanded in two campaigns to make it a place of teaching and research:
First between 1840 and 1852 by François-Alexandre Duquesney: extension of the building to the North and South, construction of the library, with cast iron pillars,...
In 1854, the grand staircase was decorated with paintings by Hugard and in 1856 by Abel de Pujol.
Then between 1861 and 1866 by Théodore-Henri Vallez, during the Haussmann's renovation of Paris (he built four wings around a central covered courtyard).
On January 21, 1926, the hotel was the subject of a first registration as a monument historique which was subsequently canceled, and on September 21, 1994, the 18th century mansion as well as the facades and roofs of the buildings of the 19th century are the subject of a new registration as monument historique.
Notes
1707 establishments in France
Vendome Paris
Buildings and structures in the 6th arrondissement of Paris
Houses completed in 1707
ParisTech
Schools of mines | Hôtel de Vendôme (boulevard Saint-Michel, Paris) | [
"Engineering"
] | 513 | [
"Schools of mines",
"Engineering universities and colleges"
] |
75,991,921 | https://en.wikipedia.org/wiki/Tricholoma%20yatesii | Tricholoma yatesii is a species of gilled mushroom. Index Fungorum and Mycobank state that the current official name of this species is Melanoleuca yatesii. It is extremely similar to Tricholoma equestre but it grows in mycorrhizal association with Quercus (oak trees and shrubs) rather than with Pinus. T. yatesii is a California mushroom, with a handful of observations from Oregon and Washington. In general it is currently "not possible to provide complete or definitive coverage of Tricholoma" in North America, so T. yatesii (and cousins) remain comparatively poorly known to both science and the general public.
William A. Murrill's original description (of what was then called Melanoleuca yatesii) was "Pileus regular, convex, solitary, 5-8 cm. broad; surface smooth, glabrous, viscid, sulfur-yellow, becoming brownish at the center on drying, margin concolorous, entire, incurved on drying; context rather thin, white to pale-yellow; lamellae sinuate-adnexed, rather broad, ventricose, not crowded, apparently pale-yellow when fresh, somewhat discolored on drying; spores ellipsoid, smooth, hyaline, 5X3 μ; stipe equal, shining, subglabrous, sulfur-yellow, becoming nearly white when dry, 6-10 cm long, 8-12 mm thick." Tricholoma yatesii is named after H. S. Yates, who collected the type species under introduced eucalyptus and endemic Monterey cypress in Berkeley, California.
See also
List of Tricholoma species
References
Fungi described in 1914
Fungi of North America
Fungus species
Taxa named by William Alphonso Murrill
yatesii
Mycorrhizal associates of oaks | Tricholoma yatesii | [
"Biology"
] | 385 | [
"Fungi",
"Fungus species"
] |
75,993,685 | https://en.wikipedia.org/wiki/Wairarapa%20Dark%20Sky%20Reserve | The Wairarapa Dark Sky Reserve is an International Dark Sky Reserve in the Wairarapa region in the southern part of the North Island of New Zealand. The reserve was designated by DarkSky International in January 2023. It was the second dark sky reserve to be certified in New Zealand (after the Aoraki Mackenzie International Dark Sky Reserve was recognised in 2012). The area covered by the reserve is and includes the Aorangi Forest Park, and the South Wairarapa and Carterton Districts.
The reserve is certified as an International Dark Sky Reserve, requiring a dark "core" zone that is surrounded by a populated area where policy controls protect the darkness of the core. For the Wairarapa reserve, the dark core is the entire area of the Aorangi Forest Park in the south of the reserve. All measurements of night sky luminance in the core area are darker than 21.3 mag/arcsec2 (corresponding to Bortle scale 3), and in places are as dark as 21.8 mag/arcsec2 (Bortle scale 1). Large parts of the Wairarapa region outside the core of the reserve exceed the minimum value of 21.2 mag/arcsec2 required for the core. Measurements taken in the town of Martinborough show that although it is located in the periphery of the reserve, it almost meets the minimum requirements for the core.
History
Proposals for a dark sky reserve in the South Wairarapa District were initially developed in 2017 and presented to an initial public meeting in Martinborough. In 2018, consultation about the proposals included the Carterton and Masterton districts. At that time, the mayor of Carterton stated that their lighting already complied with the standards, and that they would join with the South Wairarapa District in making an application for designation.
An application for Dark Sky Reserve status was submitted in December 2022. The certification by DarkSky International in 2023 was the result of 5 years of volunteer work by the Wairarapa Dark Sky Association Incorporated (a registered charity in New Zealand), and the South Wairarapa and Carterton district councils, together with other local interested parties.
In 2023, the Masterton District Council, governing an area of adjacent to the designated reserve, began planning and consultation for potentially expanding the Wairarapa Dark Sky Reserve to include the Masterton District. The work involved in making an application includes dark sky measurements and photos, a plan for lighting, and reductions in artificial lighting including changes to types of lighting and installation of shields.
References
External links
Official website
Dark Sky Reserve at South Wairarapa District Council
Star Safari Star-gazing business in Ponatahi, Wairarapa
2023 establishments in New Zealand
Dark-sky preserves in New Zealand
International Dark Sky Reserves
Wairarapa | Wairarapa Dark Sky Reserve | [
"Astronomy"
] | 564 | [
"International Dark Sky Reserves",
"Dark-sky preserves",
"Dark-sky preserves in New Zealand"
] |
75,994,051 | https://en.wikipedia.org/wiki/Ganoderma%20oregonense | Ganoderma oregonense (also known as the west-coast reishi, western varnished conk, lacquer fungus, and/or American ling-chi) is a species of bracket fungus that causes root and butt white rot in conifers in northwestern coastal North America, including California, Oregon, Washington, British Columbia, Yukon, and Alaska. G. oregonense is very similar to Ganoderma tsugae, but G. tsugae is associated with east coast Tsuga (hemlock) rather than west coast conifer. Its been speculated that G. oregonense and G. tsugae might actually be one species, but mycologists just don't know for sure yet.
Western varnished conk has a shiny brown-red-orange and sometimes cream-colored upper surface (often appearing as a color gradient), and white- or cream-colored pores. It can be shaped like a kidney or a fan or a hoof, or like a plate or stack of plates jammed into the side of a log. It fruits annually (rather than perennially), and usually shows up in the fall. They can get quite big, up to a foot in size.
Trees inoculated with G. oregonense end up with spongy, soft insides. It prefers dead red fir but will also accept dead or alive Douglas fir, spruce, hemlock, and pine. When this reishi is found on living trees it is usually consequent to tree wounds, such as bear marks.
According to Paul Stamets, this fungus is edible. This is unusual for a Ganoderma, specimens of which are usually far too tough to be eaten (reishi is often dried, powdered and consumed as a mushroom tea).
This species was originally described by W. A. Murrill as "Pileus reniform, corky, rigid, convex above, plane below, 10 x 17 x 5 cm; surface glabrous, thinly encrusted, smooth, laccate, very lustrous, bay to black, with a deep groove near the margin, which is cream-colored, rounded, smooth, entire, finely tomentose; context punky, white to slightly discolored, homogeneous, with white lines of mycelium near the stipe, 2-3.5 cm. thick; tubes annual, 1 cm. long, avellaneous within, mouths circular to angular, 3 to a mm., edges thin, entire, white to avellaneous; stipe lateral, very thick, short, subcylindric, 2-4 cm long, 3-6 cm. thick, expanding into the pileus, which it resembles in color, surface, and context."
References
External links
Phylogenetics of Ganoderma oregonense and related species in the Pacific Northwest - Kimberly Syring¹, Kelli Daffron², Dr. Jessie Uehling¹ of ¹Oregon State University Department of Botany and Plant Pathology and ²Lewis and Clark National Historical Park (PDF)
Fungi described in 1908
Fungi of North America
Fungus species
oregonense
Taxa named by William Alphonso Murrill
Edible fungi | Ganoderma oregonense | [
"Biology"
] | 653 | [
"Fungi",
"Fungus species"
] |
75,994,171 | https://en.wikipedia.org/wiki/Oil%20industry%20in%20Scotland | The oil industry in Scotland was largely created upon the discovery of North Sea oil. The country is one of the world’s leading oil producers, and in 2020, oil and gas contributed £13.8 billion to the Scottish economy and supported 100,000 jobs. Commercial extraction of oil on the shores of the North Sea dates back to 1851, when James Young retorted oil from torbanite (boghead coal, or oil shale) mined in the Midland Valley of Scotland.
Scottish waters consisting of a large sector of the North Atlantic and the North Sea, containing the largest oil resources in Western Europe. Scotland is one of Europe's largest petroleum producers, with the discovery of North Sea oil transforming the Scottish economy. Oil was discovered in the North Sea in 1966, with the first year of full production taking place in 1976. With the growth of oil exploration during that time, as well as the ancillary industries needed to support it, the city of Aberdeen became the UK's centre of the North Sea Oil Industry, with the port and harbour serving many oil fields off shore. Sullom Voe in Shetland is the site of a major oil terminal, where oil is piped in and transferred to tankers. Similarly the Flotta Oil Terminal in Orkney is linked by a 230 km long pipeline to the Piper and Occidental oil fields in the North Sea. Grangemouth is at the centre of Scotland's petrochemicals industry. The oil related industries are a major source of employment and income in these regions.
History
In December 1969, Amoco discovered the Montrose Field about east of Aberdeen. The original objective of the well had been to drill for gas to test the idea that the southern North Sea gas province extended to the north. Amoco were astonished when the well discovered oil. BP had been awarded several licences in the area in the second licensing round late in 1965, but had been reluctant to work on them.
North Sea oil
Scotland is said to be the largest producer of oil and the second largest producer of gas in Europe. Oil and gas activity in Scotland mostly takes place offshore on offshore oil and gas platforms, mainly of which are located 12 miles off the coast of Aberdeen.
Economic benefits
The extraction of oil and gas in Scottish waters was estimated to have contributed £25.2 billion in Gross Value Added (GVA) to the Economy of Scotland in 2022, representing 11.8% of the overall Scottish Gross Domestic Product (GDP) figure. In March 2023, the Scottish Government established the Energy System and Just Transition Independent Analysis Report, which found that the oil and gas industry in Scotland generated £16 billion in GVA in 2019 whilst it supported the employment of 57,000 people.
Scottish Government
Whilst the Scottish Government acknowledges the economic and social advantage that the discovery and extraction of oil and gas in the North Sea has on Scotland, it has also established ambitious transition targets to Net Zero emissions and have confirmed that "any further extraction and use of fossil fuels must be consistent with Scotland’s climate obligations and Just Transition commitments". The licensing for offshore oil and gas extraction is reserved to the UK Government, whilst the listening for onshore oil and gas extraction has been devolved to the Scottish Government. On matters relating to offshore oil and gas extraction and listening in the North Sea, the Scottish Government has called on the UK Government to establish a "four nations approach" in order to "agree a robust and transparent approach to climate compatibility checkpoints for oil and gas licensing".
Powers for the Scottish Government and Scottish Parliament to legislate on onshore oil and gas extraction was devolved on 9 February 2018. Sections 47–49 of the Scotland Act 2016 transferred powers to "legislate for the granting and regulation of onshore licences, determine the terms and conditions of licences and regulate the licensing process, including administration of existing onshore licences". All onshore oil and gas licences currently held in Scotland are set out in legislation.
Future
Decline
Although North Sea oil production has been declining since 1999, an estimated 920 million tonnes of recoverable crude oil remained in 2009. Over two and a half billion tonnes were recovered from UK offshore oil fields between the first North Sea crude coming ashore in 1975 and 2002, with most oil fields being expected to remain economically viable until at least 2020. High oil prices have resulted in a resurgence of oil exploration, specifically in the North East Atlantic basin to the west of Shetland and the Outer Hebrides, in areas that were previously considered marginal and unprofitable. The North Sea oil and gas industry contributed £35 billion to the UK economy (a little under 1% of GDP) in 2014 and is expected to decline in the coming years.
The Scottish Government recognise that the North Sea "basin is mature and oil and gas production will inevitably decline". The government is committed to the transfer of workers in North Sea oil and gas fields to transition to other sectors of the industry relating to net zero energy and other adjacent energy sectors.
In the run up to the 2014 Scottish independence referendum, it was widely claimed that North Sea oil and gas extraction was fast declining, leading to uncertainty of its future and any economic benefits it would continue to generate in an independent Scotland. This view is in sharp contrast to recent developments in 2023, with the UK Government commissioning new oil and gas fields in the North Sea off the coast of the Shetland Isles.
Transition to net-zero energy
The Scottish Government has pledged for Scotland to become a net zero energy and emissions country. Through a number of targets, the Scottish Government aim to achieve this by "commissioning and publishing independent analysis to look at the Scotland's future energy system, commissioning research and working with partners to develop carbon capture, utilisation and storage in Scotland and supporting a number of demonstration projects to develop hydrogen and hydrogen fuel cells". Additionally, the Scottish Government is committed in "supporting the transition in the North East of Scotland from oil and gas to renewables with our Energy Transition Fund , whilst supporting businesses, communities and individuals to transition to net zero and create jobs in low carbon industries through the Just Transition Fund and strategically engaging with stakeholders across the energy sector through multiple avenues, including the Scottish Energy Advisory Board (SEAB)". Furthermore, they aim to collaborate with the "North Sea Transition Deal (NSTD) through both the North Sea Transition Forum and the North Sea Transition Deal Delivery Group".
The Scottish Government has previously concluded work surrounding the policymaking process on "unconventional oil and gas development in Scotland" and have also worked to enhance the "oil and gas decommissioning capacity and capabilities through the Decommissioning Challenge Fund", which completed a total of three "successful application calls" from 2017 to 2019.
Oil and Gas stations (onshore)
See also
Energy in Scotland
1979 Scottish devolution referendum
References
Scotland
Petroleum by country | Oil industry in Scotland | [
"Chemistry"
] | 1,386 | [
"Petroleum",
"Petroleum by country"
] |
75,994,590 | https://en.wikipedia.org/wiki/Quantum%20singular%20value%20transformation | Quantum singular value transformation is a framework for designing quantum algorithms. It encompasses a variety of quantum algorithms for problems which can be solved with linear algebra, including Hamiltonian simulation, search problems, and linear system solving. It was introduced in 2018 by András Gilyén, Yuan Su, Guang Hao Low, and Nathan Wiebe, generalizing algorithms for Hamiltonian simulation of Guang Hao Low and Isaac Chuang inspired by signal processing.
High-level description
The basic primitive of quantum singular value transformation is the block-encoding. A quantum circuit is a block-encoding of a matrix A if it implements a unitary matrix U such that U contains A in a specified sub-matrix. For example, if , then U is a block-encoding of A.
The fundamental algorithm of QSVT is one that converts a block-encoding of A to a block-encoding of , where p is a polynomial of degree d and denotes the conjugate transpose, with only d applications of the circuit and one ancilla qubit. This can be done for a large class of polynomials p which correspond to applying a polynomial to the singular values of A, giving a "singular value transformation".
A variant of this algorithm can also be performed when A is Hermitian, corresponding to an "eigenvalue transformation". That is, given a block-encoding of A with eigendecomposition of a matrix , one can get a block-encoding for , provided p is bounded.
Algorithm
Input: A matrix whose singular value decomposition is where are the singular values of A
Input: A polynomial
Output: A unitary where has been applied to the singular values of :
Prepare a unitary that encodes on the top left side of , that is
Initialize an qubit state
If the polynomial is odd, first apply and then to
If the polynomial is even apply to
References
See also
Quantum algorithm
HHL algorithm
Quantum machine learning
Digital signal processing
External links
Implementation of the QSVT algorithm for matrix inversion with Classiq
Quantum computing
Quantum algorithms
Signal processing | Quantum singular value transformation | [
"Technology",
"Engineering"
] | 415 | [
"Telecommunications engineering",
"Computer engineering",
"Signal processing"
] |
75,995,045 | https://en.wikipedia.org/wiki/1%2C3-Dimethylimidazolium%20nitrate | 1,3-Dimethylimidazolium nitrate ([DMIM][NO3]) is a solvent within the imidazole-based class of ionic liquids (ILs). 1,3-Dimethylimidazolium is a five-membered ring aromatic cation composed of two nitrogen atoms and three carbon atoms, with methyl groups substituted at positions 1 and 3 of the nitrogen atoms, respectively. The nitrate anion is a poly-ion species characterized by one nitrogen atom and three oxygen atoms.
Thermodynamic properties of this compound are not available as it exhibits fast and often uncontrollable chemical decomposition, only limited data such as its melting and decomposition temperatures. Differential scanning calorimetry and thermogravimetric analysis has been performed to understand thermal decomposition kinetics. Computational methods have been used to probe some of the interactions with water.
References
Imidazoles
Nitrates
Ionic liquids | 1,3-Dimethylimidazolium nitrate | [
"Chemistry"
] | 193 | [
"Oxidizing agents",
"Nitrates",
"Salts"
] |
75,995,060 | https://en.wikipedia.org/wiki/Dictyota%20acutiloba | Dictyota acutiloba. the twisted dictyota, is a species of brown seaweed in the family Dictyotaceae. The species has been found in the Mediterranean Sea, and it has been thought that it got there via the Suez Canal.
Description
This seaweed is flexible, although it is typically thin with its twisted blades giving its wiry look. The smell is like any type of seaweed smell, which is salty and smells like the ocean. This species can grow up to . This can vary depending on the environment.
References
Seaweeds
Dictyotaceae
Species described in 1848 | Dictyota acutiloba | [
"Biology"
] | 128 | [
"Seaweeds",
"Algae"
] |
75,995,083 | https://en.wikipedia.org/wiki/Dictyota%20friabilis | Dictyota friabilis is a species of brown seaweed in the family Dictyotaceae. It has been found around the world in tropical and subtropical climates, including Hawaii, Puerto Rico, and the Gulf of Oman. There are different medical studies involving Dictyota friabilis for use in human application.
Description
Dictyota friabilis has Y-shaped branching tips and is iridescent which makes it glow bluish green. Dictyota friabilis can grow to between in size with a frond span of .
Distribution
Dictyota friabilis in tropical and subtropical climates worldwide, including Hawaii, Puerto Rico and the Gulf of Oman.
Habitat
Dictyota friabilis inhabits coastal areas at depths of up to .
Human use
There have been a few studies with the goals of using Dictyota friabilis for medical purposes. One study used dolabelladienetriol, a compound acquired from the species, to reduce the replication of HIV-1. Another study found that there were compounds that had large variation on cancer cells depending on the season, which may be due to the amount of energy being acquired from photosynthesis.
References
Dictyotaceae
Seaweeds
Species described in 1926 | Dictyota friabilis | [
"Biology"
] | 259 | [
"Seaweeds",
"Algae"
] |
75,995,640 | https://en.wikipedia.org/wiki/Hidden%20layer | In artificial neural networks, a hidden layer is a layer of artificial neurons that is neither an input layer nor an output layer. The simplest examples appear in multilayer perceptrons (MLP), as illustrated in the diagram.
An MLP without any hidden layer is essentially just a linear model. With hidden layers and activation functions, however, nonlinearity is introduced into the model.
In typical machine learning practice, the weights and biases are initialized, then iteratively updated during training via backpropagation.
References
Deep learning
Machine learning | Hidden layer | [
"Engineering"
] | 113 | [
"Artificial intelligence engineering",
"Machine learning"
] |
75,998,118 | https://en.wikipedia.org/wiki/Giry%20monad | In mathematics, the Giry monad is a construction that assigns to a measurable space a space of probability measures over it, equipped with a canonical sigma-algebra. It is one of the main examples of a probability monad.
It is implicitly used in probability theory whenever one considers probability measures which depend measurably on a parameter (giving rise to Markov kernels), or when one has probability measures over probability measures (such as in de Finetti's theorem).
Like many iterable constructions, it has the category-theoretic structure of a monad, on the category of measurable spaces.
Construction
The Giry monad, like every monad, consists of three structures:
A functorial assignment, which in this case assigns to a measurable space a space of probability measures over it;
A natural map called the unit, which in this case assigns to each element of a space the Dirac measure over it;
A natural map called the multiplication, which in this case assigns to each probability measure over probability measures its expected value.
The space of probability measures
Let be a measurable space.
Denote by the set of probability measures over .
We equip the set with a sigma-algebra as follows. First of all, for every measurable set , define the map by .
We then define the sigma algebra on to be the smallest sigma-algebra which makes the maps measurable, for all (where is assumed equipped with the Borel sigma-algebra).
Equivalently, can be defined as the smallest sigma-algebra on which makes the maps
measurable for all bounded measurable .
The assignment is part of an endofunctor on the category of measurable spaces, usually denoted again by . Its action on morphisms, i.e. on measurable maps, is via the pushforward of measures.
Namely, given a measurable map , one assigns to the map defined by
for all and all measurable sets .
The Dirac delta map
Given a measurable space , the map maps an element to the Dirac measure , defined on measurable subsets by
The expectation map
Let , i.e. a probability measure over the probability measures over . We define the probability measure by
for all measurable .
This gives a measurable, natural map .
Example: mixture distributions
A mixture distribution, or more generally a compound distribution, can be seen as an application of the map .
Let's see this for the case of a finite mixture. Let be probability measures on , and consider the probability measure given by the mixture
for all measurable , for some weights satisfying .
We can view the mixture as the average , where the measure on measures , which in this case is discrete, is given by
More generally, the map can be seen as the most general, non-parametric way to form arbitrary mixture or compound distributions.
The triple is called the Giry monad.
Relationship with Markov kernels
One of the properties of the sigma-algebra is that given measurable spaces and , we have a bijective correspondence between measurable functions and Markov kernels . This allows to view a Markov kernel, equivalently, as a measurably parametrized probability measure.
In more detail, given a measurable function , one can obtain the Markov kernel as follows,
for every and every measurable (note that is a probability measure).
Conversely, given a Markov kernel , one can form the measurable function mapping to the probability measure defined by
for every measurable .
The two assignments are mutually inverse.
From the point of view of category theory, we can interpret this correspondence as an adjunction
between the category of measurable spaces and the category of Markov kernels. In particular, the category of Markov kernels can be seen as the Kleisli category of the Giry monad.
Product distributions
Given measurable spaces and , one can form the measurable space with the product sigma-algebra, which is the product in the category of measurable spaces.
Given probability measures and , one can form the product measure on . This gives a natural, measurable map
usually denoted by or by .
The map is in general not an isomorphism, since there are probability measures on which are not product distributions, for example in case of correlation.
However, the maps and the isomorphism make the Giry monad a monoidal monad, and so in particular a commutative strong monad.
Further properties
If a measurable space is standard Borel, so is . Therefore the Giry monad restricts to the full subcategory of standard Borel spaces.
The algebras for the Giry monad include compact convex subsets of Euclidean spaces, as well as the extended positive real line , with the algebra structure map given by taking expected values. For example, for , the structure map is given by
whenever is supported on and has finite expected value, and otherwise.
See also
Mixture distribution
Compound distribution
de Finetti theorem
Measurable space
Markov kernel
Monad (category theory)
Monad (functional programming)
Category of measurable spaces
Category of Markov kernels
Categorical probability
Citations
References
Further reading
Monads of probability, measures, and valuations, in nLab.
https://ncatlab.org/nlab/show/Giry+monad
External links
What is a probability monad?, video tutorial.
Measure theory
Probability theory
Category theory | Giry monad | [
"Mathematics"
] | 1,109 | [
"Functions and mappings",
"Mathematical structures",
"Mathematical objects",
"Fields of abstract algebra",
"Mathematical relations",
"Category theory"
] |
75,998,433 | https://en.wikipedia.org/wiki/2-Hydroxysaclofen | 2-Hydroxysaclofen is a GABAB receptor antagonist and an analogue of saclofen.
Pharmacodynamics
2-Hydroxysaclofen binds to the GABAB receptor, but this is selective for the (S)-enantiomer, while the (R)-enantiomer does not bind to the GABAB protein.
2-Hydroxysaclofen has been reported to be more potent than saclofen.
See also
Saclofen - another GABAB receptor antagonist
Baclofen - an agonist of the receptor
References
GABA receptor antagonists
4-Chlorophenyl compounds
Sulfonic acids
Tertiary alcohols
Amines
Ethanolamines | 2-Hydroxysaclofen | [
"Chemistry"
] | 151 | [
"Amines",
"Bases (chemistry)",
"Functional groups",
"Sulfonic acids"
] |
75,998,545 | https://en.wikipedia.org/wiki/Ivan%20Mikhailovich%20Velikanov | Ivan Mikhailovich Velikanov (7 November 18988 April 1938), was a Soviet microbiologist who served in the late 1920s and 1930s as chief scientist of Stalin's offensive biological weapons programme.
Early life
Velikanov was born on the 7 November 1898 in the village of Yamanovo, near Kovrov, Vladimir Oblast. Prior to the October 1917 revolution he was employed as a timekeeper and clerk at the local mechanical works. In the aftermath of the revolution, Velikanov enrolled in the Faculty of Medicine at the First Moscow State Medical University. He graduated from the university in 1923. He then enrolled as a microbiologist in the Institute of Red Professors. This institution had been established in 1921 with the aim of recruiting and training a new socialist intelligentsia. He graduated from the institute in 1928 with the title of Professor. In the same year he enrolled for service within the Red Army.
A lead military biological scientist
Velikanov is described as a highly talented scientist and was appointed at a young age as Professor and Head of department at the Department of Microbiology at Moscow State University. In 1928 he was appointed director of a new facility belonging to the Red Army, the Military Vaccine-Sera Laboratory, in Vlasikha, close to the Perkhushkovo railway station, approximately 30 miles to the west of Moscow. At this time Velikanov held the rank of Divisional Doctor which corresponds to the rank of Major General in the modern Russian armed forces.
Velikanov served concomitantly as the Head of the secret Ninth Department of the Institute of Chemical Defence (IKhO). This Department was engaged in secret offensive biological warfare research involving anthrax, tularaemia, and plague bacteria. The use of Clostridium botulinum for sabotage purposes was also being considered. IKhO was itself subordinate to the Red Army's Military-Chemical Directorate (Voenno—khimicheskoe upravlenie, abbreviated to VOKhIMU) headed by Yakov Fishman.
During the period from 1929 through to 1936, Velikanov established an extensive programme of prophylaxis and therapy of botulism poisoning. His most significant scientific research relates to his work on modifying the botulinum toxin to the nontoxic form of a toxoid. In 1934 and 1936, Velikanov reported the first experimental immunization of human subjects with botulinum toxoids. The serum which he developed against botulism is reported to have saved the lives of many thousands of people. In 1935 Velikanov published The Microbiology of Tinned Goods (Mikrobiologiya konservov). His work was still being cited by Soviet authors in the 1960s.
There was almost certainly a military dimension to Velikanov's programme of research on botulism. In 1961, a CIA report on the Soviet BW programme noted that “Political refugees from the Soviet Union contend that botulinum toxin was one of the earliest candidates for agent development, chosen primarily because of its potential effectiveness by ground, air or water dispersion. Unconfirmed reports state that a purification process and suitable disseminating media were two major problems encountered in the preliminary investigations; by 1940-1941, studies on agent properties were allegedly in progress and the toxin was purportedly being stockpiled………”
The CIA report notes that one scientist in particular - possibly Velikanov himself, although the name has been redacted in the released document - “is said to have seen 227 cases of botulinum intoxication in humans, and his computations on comparative fatality rates among treated cases and untreated controls are one of the few hints of suspected human experimentation related to BW in the USSR“.
Pivotal meeting on biological warfare programme with Stalin
On the 15 April 1934, Velikanov attended a meeting of the Politburo where he was a keynote speaker. Besides Stalin himself, among the political leaders attending the meeting were Molotov, Kalinin, Kaganovich, Kuibyshev, Voroshilov, Ordzhonikidze, Andreev, Yagoda and Mikoyan. As well as Velikanov, the scientists attending the meeting included Yakov Moiseevich Fishman, who, since August 1925, had headed-up the Red Army's Military-Chemical Directorate. Also present were Karl Yur’evich Yanel’ (head of the Red Army's Institute of Chemical Warfare Defence - IKhO) and Efim Il’ich Demikhovskii (head of IKhO’s Ninth Department working on anthrax aerosols and botulinum toxins). As a direct result of the meeting, Stalin decided to concentrate the various unconnected strands of the country's BW programme within a single powerful institution - the newly created Biotechnical Institute. Stalin's enthusiastic reaction to the meeting meant that new resources were immediately provided to the BW effort, with the prime example being the transfer to it of a state-of-the-art virology institute on Gorodomlya Island, fitted out with the latest Soviet and Western technology. From this point in history through to its collapse in December 1991, the Soviet Union lavished huge resources on its secret offensive BW programme.
Management of the Biotechnical Institute & Expeditions to Vozrozhdenie Island
Immediately after the meeting with Stalin, Velikanov was appointed Director of the Biotechnical Institute, also known by its codename of V/2-1094 which, as indicated, was located on Gorodomlya Island (Lake Seliger) close to the town of Ostashkov in Tver (at that time named Kalinin) oblast’. In the Summer of 1935, Velikanov's institute conducted trials of biological munitions at the chemical weapons proving ground at Shikhany. Later, in the same year Velikanov's institute selected a 10,000 km2 tract of land on Vozrozhdenie Island in the Aral Sea as a new BW proving ground. Velikanov led the first expedition to the island in the summer of 1936. This comprised more than 100 specialists and support staff from Institute No. V/2-1094. Velikanov was provided with special ships and two airplanes and reportedly conducted experiments involving the spread of tularaemia and related microorganisms.
Velikanov's arrest and execution
It is interesting to note that the first indications that Velikanov had that he was under personal threat from the Soviet security apparatus came in the wake of his meetings with Stalin. These were apparently very unpleasant for Velikanov, who afterwards was invited for discussions with NKVD personnel. As early as the beginning of 1937, NKVD agents are reported to have begun shadowing Velikanov. They also recruited personnel from his own institute to inform on his activities. Velikanov was one of a large number of prominent BW specialists to be arrested by the security organs during the mass repression (dubbed the Great Terror) instigated within the Soviet Union by Stalin. Velikanov was arrested on the 6 July 1937 on the territory of his own institute in Vlasikha. Other victims at the Biotechnical Institute included Velikanov's wife, Zoya Ivanova Mikhailova (also a military doctor). On the 8 April 1938 Velikanov was accused by the Military Collegium of the USSR Supreme Court of being an active participant of a military-fascist conspiracy, into which he had been tempted by the national enemy, Tukhasheviskii, in 1936. At the latter's command Velikanov was alleged to have conducted sabotage in the sphere of the country's defence and prepared for the destruction of the Moscow population through food poisoning. In addition it was alleged that during his visit to Japan in 1934, he was recruited by the Japanese to undertake reconnaissance for terrorist activities. He was tried and condemned to death by shooting with confiscation of all property, as a spy and member of a “counter-revolutionary military plot”. Velikanov refused to admit his guilt and was executed later that same day.
Rehabilitation and official Russian recognition
Velikanov was officially rehabilitated on the 13 June 1956 (Velikanov, 1993). The reappraisal of Velikanov's career culminated in 2004 with this tribute made by R.N. Lukina, writing in an official volume published to mark the 50th anniversary of the Russian Ministry of Defences’ Virology Centre: “Ivan Mikhailovich Velikanov ranks among the outstanding microbiologists of the late 1930s – mid-1940s. Although I.M. Velikanov does not have a direct connection to the founding of the Virology Centre, it is impossible not to give credit to this wonderful scientist, who, being one of the pioneers of military microbiology, stood at the source of the foundation of the system of anti-epidemiological defence of both troops and the population. He was the organiser and supervisor of the Red Army's Biotechnological Institute, a forerunner of the Russian Ministry of Defence's Scientific-Research Sanitary Institute”.
References
1898 births
1938 deaths
Soviet microbiologists
People from Vladimir Oblast
People related to biological warfare
Soviet biological weapons program
Institute of Red Professors alumni
Academic staff of Moscow State University
Great Purge victims from Russia | Ivan Mikhailovich Velikanov | [
"Biology"
] | 1,926 | [
"People related to biological warfare",
"Biological warfare"
] |
75,999,810 | https://en.wikipedia.org/wiki/Wege%20zur%20Raumschiffahrt | Wege zur Raumschiffahrt (Ways to space travel) is a book by Hermann Oberth. Written in German, it was published in 1929 by the Munich Oldenbourg publishing house and was considered a standard work in rocketry for a long time. It was - with a new title and completely revised - the 3rd edition of Oberth's first book Die Rakete zu den Planetenräumen (The Rocket to Planetary Spaces), published in 1923.
In this work, Oberth “translates the dream of space travel that has been cherished by humanity for centuries into the language of formulas and construction designs.” Even after the introduction of powerful electronic computers that deliver more precise numerical results, this work and its formulas were used in research, development and teaching in space technology because “you can read from the formulas what really matters, how things are connected and how to find the best middle ground between all of this.”
Contents
The work is divided into four parts. The first part deals in general terms with the principles of recoil propulsion and its operation in space. His starting point are four assumptions that could not be verified at the time and were therefore controversial:
It is possible to build machines that can climb higher than the atmosphere can reach.
With further improvement, these machines can reach such speeds that - if left to their own devices in the ether - they do not have to fall back to the earth's surface and are even able to leave the earth's area of attraction.
Such machines can be built in such a way that people can ride up with them (probably without any health disadvantage).
Under current conditions, building such machines would be worthwhile.
In the second part (Physical-technical issues) and third part (Construction issues), Oberth describes in detail his principles of rocket propulsion using liquid fuels. He often simplifies the mathematical derivations and formulas by using approximations for certain quantities that were easier to treat mathematically. Where the values for the formula quantities were still uncertain, Oberth always calculated using unfavorable assumptions in order to be sure that his rockets could achieve the required performance. In designing a 100-ton space rocket, Oberth was the first to arrive at a three-stage rocket and to calculate the optimal ratio between the different stages.
In the fourth part Oberth discusses possible uses of his rockets, including uses of the liquid fuel rocket nozzle on earth and in rocket planes. He then calculates and describes rockets that not only ascend, but can also return to Earth afterwards –- similar to the later space shuttle.
Calculations and designs for space stations follow. He proposed numerous uses for such stations, many of which would later become reality, including global communication using satellites that receive and send signals, observation of the earth's surface, especially that of unexplored countries, support of maritime navigation (by warning of icebergs), observation of meteorological data for weather forecasting, and using a space station as a stopover and fuel depot for transportation to other planets. He also described solar sails for stabilizing and propelling satellites.
Oberth foresaw and developed concepts for generating energy in space for use on Earth using mirrors or electrical waves (microwaves). This concept was taken up again in feasibility studies in the United States from 1968 under the name Solar Power Satellite (SPS) and has since been viewed as technically feasible in principle. Finally, Oberth discusses the requirements and technical possibilities for traveling to foreign bodies (moon, asteroids, Mars, Venus, etc.), with an emphasis on the use of an electric spaceship. The technology used here is now known and tested as ion drive.
Editions
The first edition appeared in 1923 with the title Die Rakete zu den Planetenräumen (The Rocket to Planetary Spaces). The work sparked heated debate, known at the time as the Battle of the Many Formulas. The second edition was published in 1925 and was sold out after a short time. The third, expanded edition appeared in 1929 with the new title Wege zur Raumschiffahrt (Ways to space travel). In the years that followed, the book became a standard text in space research and rocketry. In 1960 the book was republished under the original title Die Rakete zu den Planetenräumen. In 1972 NASA issued an authorized English translation. In 1974, Kriterion Verlag, Bucharest, published the new edition of Ways to space travel, with a foreword by Elie Carafoli and updated notes by the author.
Recognition
In 1929, the International Prize for Space Sciences (REP-Hirsch Prize) in Paris was awarded for the first time to Hermann Oberth. In the years that followed, the book became the standard work on space research and rocketry and was called the “Bible of scientific astronautics” by the French aviation and rocket pioneer Robert Esnault-Pelterie.(see p. 117). Oberth's former student, Wernher von Braun, wrote in the foreword to the 4th edition of “The Rocket to Planetary Spaces” in 1964: “Hermann Oberth was the first to use a slide rule and work through numerical concepts in connection with the idea of a real space journey and presented construction designs. ... Hermann Oberth not only solved the theoretical problems of rocket science and designed the necessary technology so that people can penetrate into space, live and work there. He was also determined to make all of these possibilities a reality. Therefore, he is undoubtedly the father of space travel.”(pages 17–18).
References
External links
Full text of (1929 edition; in German) at HathiTrust Digital Library
History of spaceflight
German-language literature
1929 non-fiction books
Space technology
Spaceflight books | Wege zur Raumschiffahrt | [
"Astronomy"
] | 1,165 | [
"Space technology",
"Outer space"
] |
76,000,464 | https://en.wikipedia.org/wiki/Sweet%20Baby%20Inc. | Sweet Baby Inc. is a Canadian narrative development and consultation studio based in Montreal. Founded by former Ubisoft developers, including scriptwriter Kim Belair and product manager David Bédard, the company consults on video game narratives during development to promote diversity, equity, and inclusion within game narratives and studios. Sweet Baby has consulted with several developers and games, including Sable, God of War Ragnarök, and Alan Wake 2. In 2023, the studio became the target of online users who claimed it promoted a "woke agenda".
History
Sweet Baby Inc. was founded in Montreal in 2018 by former Ubisoft developers, including scriptwriter Kim Belair and product manager David Bédard. Belair became Sweet Baby's chief executive officer and Bédard the chief operating officer. Belair said that she founded the company to promote the advancement of women and marginalized groups in the video game industry.
The company consults on game narratives during development and promotes gender and racial diversity in development teams, including correct and consistent pay, training, and credits. Sweet Baby's stated goal is to ensure characters from different demographic groups are not only added for nominal presence, but that their portrayal is respectful, fits into the overall context, and is written for quality scenarios. To achieve this, Sweet Baby organizes developer consultations with representatives of different ethnic groups and cultures when creating characters from these same cultures. The company connects developers with studios when vacancies arise. While the studio can be consulted at any point in development, Belair felt it had a better chance at improvement by entering early to avoid undoing completed work.
From 2018, Bédard was the brand content manager and Belair the story architect on Unknown 9, a transmedia project encompassing comics, novels, and video games, initially as employees of developer Reflector Entertainment and later as part of Sweet Baby. The studio consulted on the narrative and characters of God of War Ragnarök, focusing on making the black character Angrboda more relatable to black audiences while acknowledging the game's Norse mythology. Sweet Baby joined the development of Goodbye Volcano High in 2020 and led the narrative team after development rebooted in 2021.
In 2022, the studio developed Lost Your Marbles for the Playdate handheld console, and formed two teams of around twelve people to assist in the development of two other Playdate games over the course of six months: Recommendation Dog and Reel Steel. Bédard felt undertaking two projects simultaneously was "a bit too ambitious" for the studio due to their differing production schedules. The studio joined Afterlove EP as consultants after the death of writer and designer Mohammad Fahmi in 2022, having been speaking with Fahmi before his death. Belair assisted Remedy Entertainment in refining the background and story arc of Saga Anderson, the protagonist of Alan Wake 2, and worked with A44 Games in developing Nor Vanek, the protagonist of Flintlock: The Siege of Dawn. The studio joined the production of Suicide Squad: Kill the Justice League late in its development, focusing on writing audio logs, non-player character dialogue, and in-game advertisements. Sweet Baby was also involved in writing the script for Marvel's Spider-Man 2. As of April 2024, Sweet Baby had 16 employees.
Online backlash and harassment
In October 2023, Sweet Baby attracted negative attention on Kiwi Farms, a web forum where a user described the company's involvement with Alan Wake 2 as "possibly one of the biggest scandals in gaming history"; similar posts were shared on sites like 4chan and the Reddit community r/KotakuInAction. Employees said a small degree of harassment was directed towards the company following this attention, which increased in January 2024, when a Steam user created a curator group listing Sweet Baby's work, encouraging players to avoid the games as the studio promoted a "woke agenda". The curator group, known as "Sweet Baby Inc detected", received increased attention in February when a Sweet Baby employee asked others to report the group and its creator for violating Steam's code of conduct. The group's creator accused Sweet Baby of censorship. By April, the group had more than 355,000 followers and a related Discord server had thousands of members. Both underwent purges of content in order to stay online after Steam and Discord staff contacted their moderators about potentially violating terms of service, as much of the user-driven content bordered on hate speech. Belair said Sweet Baby did not contact Steam's owner, Valve, regarding the group.
Theories about the studio included that it was directly or indirectly controlled by investment company BlackRock, that it forced Remedy to make Alan Wake 2s Saga Anderson black (which game director Kyle Rowley denied), and that it was responsible for recent failures in high-profile games such as Suicide Squad and for recent industry layoffs. Multiple journalists described these disproven ideas as conspiracy theories; several were based on isolated statements made by Sweet Baby employees on social media or at conferences, taken out of the larger context related to their views on diversity in game narratives. Aftermaths Nathan Grayson noted theories would likely continue spreading as long as their narrative compelled viewers and readers; YouTube videos about the backlash collectively received millions of views. Belair responded that Sweet Baby's work was to improve narratives generally rather than being solely focused on diversity and inclusion; she noted gamers thought the studio had simply added pride flags to Marvel's Spider-Man 2 when it had actually provided narrative work for about three years, including several levels and character arcs.
Sweet Baby's employees faced harassment and attempted doxing in response to the backlash, with attention drawn towards the company and its employees by high-profile social media accounts including Elon Musk, Matt Walsh, and Libs of TikTok. Others who faced harassment included Kotakus reporter who first highlighted the backlash and developers who worked with or publicly supported Sweet Baby. Several journalists and content creators compared it to Gamergate, and TheGamers Stacey Henley called it "the latest dogwhistle for rejecting progressive ideas". The Verges Ash Parrish felt the Discord members were not attempting to "create meaningful change for their cause" but were "simply there for the vibes, rancid though they are". The studio continued to operate as normal; Bédard felt the industry had become familiar with similar controversies since Gamergate. Its partners, like Insomniac Games, offered advice on moving past the backlash based on their own experiences with harassment, and several developers and consultants, like Rami Ismail and Steve Saylor, supported the studio on social media. Journalists and academics urged the studio's other partners to publicly defend it to stop false accusations and avoid complicity, and Game Developers Bryant Francis urged Steam and Discord to clarify their policies to avoid similar incidents and further harassment.
List of games
Notes
References
External links
2018 establishments in Quebec
Canadian consultants
Companies based in Montreal
Diversity (business)
Diversity in computing
Progressivism in Canada
Video game companies established in 2018
Video game companies of Canada
Video game controversies
Video game development companies | Sweet Baby Inc. | [
"Technology"
] | 1,430 | [
"Computing and society",
"Diversity in computing"
] |
76,000,797 | https://en.wikipedia.org/wiki/New%20materialism | New materialism is a term which refers to several theoretical perspectives within contemporary philosophy that attempt to rework the conventional ontological understanding of the material world. While many philosophical tendencies are associated with new materialism, in such a way that the movement resists a single definition, its common characteristics include a rejection of essentialism, representationalism, and anthropocentrism as well as the dualistic boundaries between nature/culture; subject/object; and human/non-human. Instead, new materialists emphasize how fixed entities and apparently closed systems are produced through dynamic relations and processes, considering the distribution of agency through the interaction of heterogeneous forces. The movement has influenced a wide variety of new articulations between intellectual currents in science and philosophy, in fields such as science and technology studies, as well as systems science.
Origin
The term was independently coined by Manuel DeLanda and Rosi Braidotti during the second half of the 1990s to identify an emerging body of interdisciplinary theory that sought to overcome the post-structuralist emphasis on discourse, while drawing on the work of Gilles Deleuze, Félix Guattari, and Gilbert Simondon in seeking to establish a materialist ontology that prioritizes processes of individuation.
Reception
As of 2024, new materialism has been well-received in a wide range of disciplines in contemporary academia, from environmental studies to philosophy. Frequently referenced works include Karen Barad's Meeting the Universe Halfway and Jane Bennett's Vibrant Matter. New Materialists emphasise how Cartesian binaries around human and nature have caused many issues in the world by ignoring social complexity. New materialism been championed for its more integrated approach that considers material and immaterial, biological, and social aspects as interconnected processes rather than distinct entities.
Criticism
Ecologist Andreas Malm has called New Materialism 'idealism of the most useless sort', stating that the approach has little use for climate action or changing our relationship with nature, since it denies distinctions between humanity and nature. Malm argues that this supports the status quo rather than challenging it. He also expresses frustration with the writing style of many New Materialists, claiming that they resist distinctions between things, making their writing impenetrable.
Associated theorists
Karen Barad
Jane Bennett
Rosi Braidotti
Donna Haraway
Isabelle Stengers
Rick Dolphijn
Manuel DeLanda
Catherine Malabou
Quentin Meillassoux
Bruno Latour
Arturo Escobar
Levi Bryant
Drew M. Dalton
Thomas Nail
Tim Ingold
See also
Posthumanism
Assemblage
Agential realism
Speculative realism
References
Bibliography
Materialism
Political ecology
Contemporary philosophy
Philosophical schools and traditions | New materialism | [
"Physics",
"Environmental_science"
] | 536 | [
"Materialism",
"Political ecology",
"Environmental social science",
"Matter"
] |
76,001,041 | https://en.wikipedia.org/wiki/Crinine | Crinine in an alkaloid found in a variety of plants including many species in the family Amaryllidaceae. It was first isolated and characterized in the 1950s as a constituent of several plants in the genus Crinum, from which it derives its name.
Several laboratory syntheses of crinine have been reported.
Related compounds
There are many alkaloids with a chemical structure similar to crinine and they are generally referred to as crinine-type alkaloids. As of 2020, there were at least 85 known crinine-type alkaloids.
References
Alkaloids
Heterocyclic compounds with 4 rings
Cyclohexenols
Benzodioxoles | Crinine | [
"Chemistry"
] | 144 | [
"Organic compounds",
"Biomolecules by chemical classification",
"Natural products",
"Alkaloids"
] |
76,001,746 | https://en.wikipedia.org/wiki/Ormetoprim | Ormetoprim is an antibiotic used in veterinary medicine. Typically it is used in combination with sulfadimethoxine, and it is used in the poultry and aquaculture industries.
Ormetoprim, like other diaminopyrimidines such as trimethoprim, inhibits the reduction of dihydrofolic acid to tetrahydrofolic acid by bacterial cells.
References
Antibiotics
Bacterial dihydrofolate reductase inhibitors
Aminopyrimidines
Veterinary drugs
Methoxy compounds | Ormetoprim | [
"Biology"
] | 108 | [
"Antibiotics",
"Biocides",
"Biotechnology products"
] |
76,003,927 | https://en.wikipedia.org/wiki/Collybia%20brunneocephala | Collybia brunneocephala, also known as the brown blewit or brownit, is a species of gilled mushroom. Previously designated Clitocybe brunneocephala, the brownit and its lavender-colored cousin the wood blewit were reassigned to the genus Collybia in 2023.
As its name implies, the brownit is a brown-capped mushroom with light-beige gills. The cap is usually described as "lubricious" and often has a rubbery-translucent gloss without being sticky. The brownit also has a bit of a stumpy, short-legged quality, as the ratio of cap diameter to stipe height heavily favors the cap. The brownit flushes most frequently from December to March, and is most commonly observed in California in western North America. Often found in lawns and open meadows, sometimes in fairy rings, it also turns up under California native oaks and Monterey cypress.
The brownit is considered a "excellent" edible mushroom, but it can be confused with Entoloma lividoalbum, Entoloma sericatum, and Entoloma rhodopolium, all of which are poisonous. Brownits can also be mistaken for Collybia nuda (which it resembles in both "size and stature") and Clitocybe tarda, but can be distinguished by color and size. C. nuda often looks brown in age, but will retain undertones of lilac. Clitocybe tarda mushrooms are smaller than C. brunneocephala and will retain some hint of purple on the cap, unlike Collybia brunneocephala which stays in the color range from brown to light beige.
William A. Murrill originally described this species in 1913 as a Melanoleuca, based on a specimen collected by R. A. Harper in Alameda County, California. However, based on the minimal information provided, it was not included in later descriptions of Clitocybe species. The brownit was rediscovered by David Arora in Santa Cruz County, California, in the 1970s, and Howard E. Bigelow formally redescribed it in his 1982 Clitocybe monograph using Arora's specimens. There was already a Clitocybe harperi, so the Bigelow gave it a new name suggestive of its brown (brunneo-) head (-cephela). According to recent genetic studies by taxonomists in China, C. brunneocephala belongs to a subgenus designated Leucocalocybe, along with what were formerly designated Lepista personata, Lepista nuda, Lepista fibrosissima, Lepista sordida, and , "forming a strongly supported monophyletic clade (BP = 95%, PP = 1.00)."
See also
Clitocybe violaceifolia
References
Edible fungi of California
Fungi described in 1982
Fungi of North America
Fungus species
Tricholomataceae
Fungi found in fairy rings | Collybia brunneocephala | [
"Biology"
] | 634 | [
"Fungi",
"Fungus species"
] |
73,075,963 | https://en.wikipedia.org/wiki/HR%205907 | HR 5907, also known as V1040 Scorpii and HD 142184, is a star about 470 light years from the Earth, in the constellation Scorpius. It is a 5th magnitude star, so it will be faintly visible to the naked eye of an observer far from city lights. Its brightness varies slightly, ranging from magnitude 5.39 to 5.43 every 12 hours and 20 minutes. HR 5907 is a member of the Scorpius–Centaurus association.
Spectroscopic observations by William Buscombe and Pamela Morris during the years 1956 through 1959 showed that the radial velocity of HR 5907 varied by about 50 km/sec. In 1966, Graham Hill first detected brightness variations in HD 5907. He determined that the brightness varied by 0.03 magnitudes, but was unable to classify the star's type of variability. In 1998, Anne Marie Hubert and Michele Floquet examined the Hipparcos data for the star, confirmed that its brightness varies, and derived a period of 0.508 days with no indications of long-term variability. In 1996 HR 5907 was given the variable star designation V1040 Scorpii.
As of 2018, HR 5907 was the most luminous early spectral type star known at centimeter and millimeter radio wavelengths. On the other end of the electromagnetic spectrum, in 2012 it was clearly detected by the Chandra X-ray Observatory.
HR 5907 is a main sequence star with a strong magnetic field. As of 2018, it had the shortest rotation period known of any early spectral type magnetic star. It spins so rapidly that the star's polar radius is only 88% as large as the equatorial radius. The star has a dipole magnetic field strength of at least 10 kilogauss.
References
Scorpius
077859
142184
Scorpii, V1040
5907
SX Arietis variables
B-type main-sequence stars | HR 5907 | [
"Astronomy"
] | 400 | [
"Scorpius",
"Constellations"
] |
73,078,000 | https://en.wikipedia.org/wiki/Porous%20medium%20equation | The porous medium equation, also called the nonlinear heat equation, is a nonlinear partial differential equation taking the form:where is the Laplace operator. It may also be put into its equivalent divergence form:where may be interpreted as a diffusion coefficient and is the divergence operator.
Solutions
Despite being a nonlinear equation, the porous medium equation may be solved exactly using separation of variables or a similarity solution. However, the separation of variables solution is known to blow up to infinity at a finite time.
Barenblatt-Kompaneets-Zeldovich similarity solution
The similarity approach to solving the porous medium equation was taken by Barenblatt and Kompaneets/Zeldovich, which for was to find a solution satisfying:for some unknown function and unknown constants . The final solution to the porous medium equation under these scalings is:where is the -norm, is the positive part, and the coefficients are given by:
Applications
The porous medium equation has been found to have a number of applications in gas flow, heat transfer, and groundwater flow.
Gas flow
The porous medium equation name originates from its use in describing the flow of an ideal gas in a homogeneous porous medium. We require three equations to completely specify the medium's density , flow velocity field , and pressure : the continuity equation for conservation of mass; Darcy's law for flow in a porous medium; and the ideal gas equation of state. These equations are summarized below:where is the porosity, is the permeability of the medium, is the dynamic viscosity, and is the polytropic exponent (equal to the heat capacity ratio for isentropic processes). Assuming constant porosity, permeability, and dynamic viscosity, the partial differential equation for the density is:where and .
Heat transfer
Using Fourier's law of heat conduction, the general equation for temperature change in a medium through conduction is:where is the medium's density, is the heat capacity at constant pressure, and is the thermal conductivity. If the thermal conductivity depends on temperature according to the power law:Then the heat transfer equation may be written as the porous medium equation:with and . The thermal conductivity of high-temperature plasmas seems to follow a power law.
See also
Diffusion equation
Porous medium
References
External links
The Porous Medium Equation: Mathematical theory
Partial differential equations
Diffusion
Hydrogeology
Heat transfer
Transport phenomena
Exactly solvable models | Porous medium equation | [
"Physics",
"Chemistry",
"Engineering",
"Environmental_science"
] | 506 | [
"Transport phenomena",
"Physical phenomena",
"Heat transfer",
"Diffusion",
"Hydrology",
"Chemical engineering",
"Thermodynamics",
"Hydrogeology"
] |
73,078,347 | https://en.wikipedia.org/wiki/Cole%E2%80%93Hopf%20transformation | The Cole–Hopf transformation is a change of variables that allows to transform a special kind of parabolic partial differential equations (PDEs) with a quadratic nonlinearity into a linear heat equation. In particular, it provides an explicit formula for fairly general solutions of the PDE in terms of the initial datum and the heat kernel.
Consider the following PDE:where , are constants, is the Laplace operator, is the gradient, and is the Euclidean norm in . By assuming that , where is an unknown smooth function, we may calculate:Which implies that:if we constrain to satisfy . Then we may transform the original nonlinear PDE into the canonical heat equation by using the transformation:
This is the Cole-Hopf transformation. With the transformation, the following initial-value problem can now be solved:The unique, bounded solution of this system is:Since the Cole–Hopf transformation implies that , the solution of the original nonlinear PDE is:
The complex form of the Cole-Hopf transformation can be used to transform the Schrödinger equation to the Madelung equation.
Applications
Aerodynamics
Stochastic optimal control
Solving the viscous Burgers' equation
Madelung equation
References
Partial differential equations
Transformation (function)
Parabolic partial differential equations | Cole–Hopf transformation | [
"Mathematics"
] | 260 | [
"Geometry",
"Transformation (function)"
] |
73,078,834 | https://en.wikipedia.org/wiki/Ethylphosphonoselenoic%20dichloride | Ethylphosphonoselenoic dichloride is a selenium-containing organophosphorus compound. It's the precursor to selenophos, the selenium analog of the VE nerve agent.
See also
Methylphosphonyl dichloride
References
Organophosphorus compounds
Organoselenium compounds | Ethylphosphonoselenoic dichloride | [
"Chemistry"
] | 73 | [
"Organophosphorus compounds",
"Organic compounds",
"Functional groups"
] |
73,080,425 | https://en.wikipedia.org/wiki/Leucocoprinus%20inflatus | Leucocoprinus inflatus is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was described in 1987 by the mycologist Jörg Raithelhuber who classified it as Leucocoprinus inflatus.
Raithelhuber based his classification on Lepiota trombophora Berk. & Broome ss. Johannes Rick in Iheringia : Série Botânica 8 - Basidiomycetes Eubasidii in Rio Grande do Sul - Brasilia however this appears to be a typo as the correct name (and the name used by Rick) is Lepiota thrombophora.
Agaricus (Lepiota) thrombophorus was described in 1871 by the British mycologists Miles Joseph Berkeley and Christopher Edmund Broome and classified as Lepiota thrombophora by Pier Andrea Saccardo in 1887.
Raithelhuber states that the species described by Rick is not the same as that described by Berk. & Broome however and notes that no preserved material from Rick exists for this species so Raithelhuber's classification of Leucocoprinus inflatus is based on Rick's description with the spore size quoted directly from Rick. Raithelhuber notes that Leucocoprinus inflatus may possibly just be a variety of Leucocoprinus bulbipes and the spore size of the two species is very similar.
Rick also notes a similarity to Lepiota alborussa and Lepiota clypeolariae.
Description
Leucocoprinus inflatus is a small dapperling mushroom.
Cap: 2.5-3.5cm wide with thin, almost membranous flesh and striations across almost the entire cap. The surface is pale with black fibrous scales and a very dark umbo. Stem: 3.5-4.5cm long, 3mm wide at the top and 7mm at the bulbous base. The surface is white with a powdery coating and the stem ring is white, wide and hanging. Gills: White but discolouring slightly yellow with age. Somewhat distant and bulging in the middle with denticulate edges. Spores: Smooth with a visible pore. 10-12 x 7-9 μm.
Lepiota thrombophora was described by Berk and Broome as having a white, conical cap covered with lumpy brown scales, a furfuraceous stem and white gills.
Etymology
The specific epithet inflatus is Latin for swollen up.
Habitat and distribution
The specimens were found growing on the ground in Brazil.
References
inflatus
Fungi described in 1987
Fungi of South America
Fungus species | Leucocoprinus inflatus | [
"Biology"
] | 564 | [
"Fungi",
"Fungus species"
] |
73,080,455 | https://en.wikipedia.org/wiki/Southern%20maned%20sloth | The southern maned sloth (Bradypus crinitus) is a three-toed sloth species.
Description
The southern maned sloths have flatter skulls, rounder jaws, and wider cheekbones than the northern maned sloths. The species has a head that looks like a coconut.
Distribution
The sloth is endemic to Brazil's Atlantic Forest, a highly biodiverse region. Southern maned sloths were found in Rio de Janeiro and Espírito Santo.
Discovery
The species was discovered by John Edward Gray in 1850, but his assertions were later dismissed, with taxonomists agreeing that the specimen, that Gray described was a B. torquatus, but the new study proves that B. critinus does indeed exist. The B. crinitus separated from B. torquatus in the north by more than 4 million years of evolution.
B.torquatus and B. crinitus are allopatrically distributed that diverged during the Early Pliocene (period of global cooling). Miranda, F. R., Garbino, G. S., Machado, F. A., Perini, F. A., Santos, F. R., & Casali, D. M. (2022). Taxonomic revision of maned sloths, subgenus Bradypus (Scaeopus), Pilosa, Bradypodidae, with revalidation of Bradypus crinitus Gray, 1850. Journal of Mammalogy, 104(1), 86–103. https://doi.org/10.1093/jmammal/gyac059
Name
The sloth received Gray's old name, Bradypus crinitus. The name crinitus means 'hairy', referring to its coconut-like head.
References
External links
Sloths
Mammals of Brazil
Endemic mammals of Brazil
Vulnerable species
Mammals described in 1850
Taxa named by John Edward Gray
Fauna of the Atlantic Forest | Southern maned sloth | [
"Biology"
] | 405 | [
"Vulnerable species",
"Biota by conservation status"
] |
73,080,640 | https://en.wikipedia.org/wiki/Leucocoprinus%20revolutus | Leucocoprinus revolutus is a species of mushroom producing fungus in the family Agaricaceae.
Taxonomy
It was described in 1937 by the mycologist Johannes Rick who classified it as Lepiota revoluta. Rick also noted a possible similarity to Lepiota spodolepsis as classified by Berk. & Broome however this species is not recorded in Species Fungorum or Mycobank and no citation is given for the text in which it may have been described.
In 1987 it was reclassified as Leucocoprinus revolutus by the mycologist Jörg Raithelhuber.
Description
Leucocoprinus revolutus is a small dapperling mushroom.
Cap: 8-13mm wide starting hemispherical before expanding and curving upwards with a small umbo. The surface is grey-blackish with striations from the margins and the cap flesh is membranous or fibrous. Gills: White, moderately densely spaced, bulging with smooth edges. Stem: 2 cm long and 2mm wide, stiff and filamentous. The surface is pale and smooth with a whitish ring. Spores: Raithelhuber described the spores as 'Oval, smooth. 7–8.1 x 4.4-5.2 μm.' However the spore size given by Rick is 5-6 x 3-4 μm.
Etymology
The specific epithet revolutus is Latin for rolled backward. This is in reference to the description of the cap shape given in Latin by Rick of 'hemisphaerico-revoluto'.
Habitat and distribution
The specimens were found growing on the ground in Brazil.
References
revolutus
Fungi described in 1987
Fungi of South America
Fungus species | Leucocoprinus revolutus | [
"Biology"
] | 361 | [
"Fungi",
"Fungus species"
] |
73,081,028 | https://en.wikipedia.org/wiki/Gaia%20BH2 | Gaia BH2 (Gaia DR3 5870569352746779008) is a binary system consisting of a red giant and what is very likely a stellar-mass black hole. Gaia BH2 is located about 3,800 light years away ( away) in the constellation of Centaurus, making it the third-closest known black hole system to Earth. Gaia BH2 is the second black hole discovered from Gaia DR3 astrometric data.
The black hole and red giant orbit the system barycentre every 1,277 days, or around 3.5 years, with a moderate eccentricity of 0.518. The black hole's mass is around , which means its Schwarzschild radius should be about . The red giant has a mass of and a radius of . Its temperature is estimated at .
Discovery
Gaia BH2 was originally discovered as a black hole binary candidate in 2022, found via astrometric observations with Gaia, along with Gaia BH1. At that time it was not clear if Gaia BH2 did definitely harbour a black hole, but it was the only plausible candidate in the Gaia data other than Gaia BH1. Later radial velocity observations confirmed this black hole system and refined its orbital parameters.
References
Centaurus
Red giants
Stellar black holes
Astrometric binaries
20230215 | Gaia BH2 | [
"Physics",
"Astronomy"
] | 286 | [
"Black holes",
"Stellar black holes",
"Unsolved problems in physics",
"Centaurus",
"Constellations"
] |
73,081,332 | https://en.wikipedia.org/wiki/Aluminium%E2%80%93copper%20alloys | Aluminium–copper alloys (AlCu) are aluminium alloys that consist largely of aluminium (Al) and traces of copper (Cu) as the main alloying elements. Important grades also contain additives of magnesium, iron, nickel and silicon (AlCu(Mg, Fe, Ni, Si)), often manganese is also included to increase strength (see aluminium-manganese alloys). The main area of application is aircraft construction. The alloys have medium to high strength and can be age hardened. They are both . Also available as cast alloy. Their susceptibility to corrosion and their poor weldability are disadvantageous.
Duralumin is the oldest variety in this group and goes back to Alfred Wilm, who discovered it in 1903. Aluminium could only be used as a widespread construction material thanks to the aluminium-copper alloys, as pure aluminium is much too soft for this and other hardenable alloys such as aluminium-magnesium-silicon alloys (AlMgSi) or the naturally hard (non-hardenable) alloys.
Aluminium–copper alloys were standardised in the 2000 series by the international alloy designation system (IADS) which was originally created in 1970 by The Aluminum Association. The 2000 series includes 2014 and 2024 alloys used in airframe fabrication.
Copper alloys with aluminium as the main alloying metal are known as aluminium bronze, the amount of aluminium is generally less than 12%.
History
Duralumin is a trade name for one of the earliest types of age-hardenable aluminium alloys. The term is a combination of Dürener and aluminium. Its use as a trade name is obsolete. Duralumin was developed by the German metallurgist Alfred Wilm at Dürener Metallwerke AG. In 1903, Wilm discovered that after quenching, an aluminium alloy containing 4% copper would harden when left at room temperature for several days. Further improvements led to the introduction of duralumin in 1909. The name is mainly used in pop-science to describe all Al-Cu alloys system.
Aluminium–copper alloys were standardised in the 2000 series by the international alloy designation system (IADS) which was originally created in 1970 by the Aluminum Association. 2000s series includes 2014 and 2024 alloys used in airframe fabrication.
Pure AlCu wrought alloys
All AlCu alloys are based on the system of pure AlCu alloys.
Solubility of copper and phases
Aluminium forms a eutectic with copper at 547 °C and 33 mass percent copper, which also corresponds to the maximum solubility. At lower temperatures, the solubility drops sharply; at room temperature it is only 0.1%.
At higher copper contents, Al2Cu is formed, an intermetallic phase. It is present in a tetragonal structure, which is so different from the cubic crystal system of aluminium that the -phase exists only as an . There are also the partially coherent ones - and -phases.
Microstructural transformations
After casting, the material is usually oversaturated - Mixed crystal, which also contains more copper at room temperature than could actually be dissolved at this temperature.
After that, GP zones (GP(I) zones) form at temperatures below 80 °C, in which increased concentrations of copper are present, but which do not yet have a structure or form their own phases.
At somewhat higher temperatures of up to 250 °C, this forms -phase (also called GP(II) zones), which increases strength.
At even higher temperatures, the partially coherent forms -Phase.
At still higher temperatures of about 300 °C the incoherent one forms -phase in which the strength decreases again.
The individual temperature ranges overlap: Even at low temperatures, there is formation of - or phases, but these form much more slowly than the GP(I/II) zones. Each of the phases forms faster the higher the temperature.
GP(I) zones
The formation of GP(I) zones is referred to as natural hardening and occurs at temperatures up to 80 °C. They are tiny disc-shaped layers just one atom thick and 2 to 5 nanometers in diameter. With time, the number of zones increases and the copper concentration in them increases, but not their diameter. They are coherent with the aluminum lattice and form on the {100} planes.
GP(II) zones
The GP(II) zones (-phases) are largely responsible for the increase in strength of the AlCu alloys. They are coherent with the aluminium crystal and consist of alternating layers of aluminium and copper with layer thicknesses of about 10 nanometers and dimensions of up to 150 nanometers. In contrast to the GP(I) zones, these are three-dimensional precipitations. Their layers are parallel to the aluminium {100} plane. From the -phase forms the -phases, but there are overlaps.
The GP(II) zones need vacancies for growth, which is why a lack of these (e.g. due to magnesium) leads to delayed growth.
Partially coherent phases
The -phase is only partially coherent with the aluminium lattice and forms at temperatures from 150 °C to 300 °C. It has the form of platelets and can arise from the GP(II) zones. However, it can also arise directly as a precipitation from the mixed crystal. In the first case, the increasing surface tension is reduced by dislocations, in the second case, the precipitates form preferentially at dislocations.
Incoherent phases
The -phase is incoherent with the lattice of the mixed crystal. It forms at temperatures of 300 °C and more. It usually forms larger particles with a larger spacing than the other phases and thus does not lead to any increase in strength or even to a drop if its formation takes place at the expense of the other phases. The -phase also occurs at temperatures between 150 °C and 250 °C as precipitation at grain boundaries, as this reduces the surface tension.
The -phase leads to a partial intergranular fracture; however, the fracture behavior remains ductile overall. The change in fracture behavior is caused by precipitation-free zones at the grain boundaries.
The -phase has a greater potential difference compared to the mixed crystal, so that layer corrosion and intergranular corrosion can occur. With longer annealing times, the inside of the grains also separate the -phases, the potential difference is additionally lower.
Grades, alloying elements and contents
As with almost all aluminium alloys, a distinction is made between for rolling and forging and for casting.
The copper content is usually between 3 and 6%. Between 0.3% and 6% the alloys are regarded as not weldable or very difficult to weld (by fusion welding), with higher copper contents they become weldable again. Most types also contain additives of magnesium, manganese and silicon to increase strength. Lead and bismuth form small inclusions that melt at low temperatures, resulting in better chip formation, similar to free machining steel. The heat resistance is increased by adding nickel and iron.
Iron, is found as an impurity in engineering alloys, preventing strain hardening, but adding magnesium makes the aforementioned process possible again. Larger amounts of magnesium up to 1.5% increase strength and elongation at break (see Aluminium-magnesium alloy). Manganese is also used to increase strength (see AlMn). Larger amounts, however, have negative side effects, so the content is limited to around 1% manganese. Smaller additions of silicon are added to bind iron, since it prefers to form the AlFeSi phase, while the formation of Al7Cu2Fe would remove larger amounts of copper from the material, which then no longer leads to the formation of phases that are actually desired (especially Al2Cu, copper aluminide). Larger amounts of silicon are alloyed to form with magnesium Mg2Si (magnesium silicide) which, like aluminium-magnesium-silicon alloy, improves strength and hardenability.
Lithium is added to some alloys with contents between 1.5% and 2.5%. Due to the very low density of Li (0.53 g/cm³ compared to 2.7 g/cm³ of aluminium), this leads to lighter components, which is particularly advantageous in aviation. See aluminium-lithium alloy for details.
Cast alloys
Cast alloys contain about 4% copper and small amounts of other additives that improve castability, including titanium and magnesium. The starting material is primary aluminium; in contrast to other cast aluminium alloys, secondary aluminium (made from scrap) is not used because it reduces elongation and toughess at break. The AlCu cast alloys are prone to hot cracking and are used in the T4 and T6 hardening states.
The following table shows the composition of some grades according to DIN EN 1706. All data is shown in percent by mass, the rest of the materials is aluminium.
Wrought alloys
AlCuMg(Si,Mn) wrought alloys
The AlCuMg alloys represent the most important group of AlCu alloys. Many other phases can form in them:
Al8 Mg5 (-phase, see )
Al2 CuMg, the S phase
Al6 Mg4 Cu, the T phase
The addition of magnesium accelerates the process of cold hardening. Which phases are formed depends primarily on the ratio of copper to magnesium. If the ratio is less than 1/1, clusters containing Cu and Mg are eliminated. At a ratio above 1.5/1, which is the case with most engineering alloys, the forms preferentially phase. These kinds of alloys have significantly higher hardness and strength.
Mechanical properties
Conditions:
O soft (, also hot-formed with the same strength limit values)
T3: solution annealed, quenched, work hardened and naturally aged
T4: solution annealed, quenched and artificially aged
T6: solution heat treated, quenched and artificially aged
T8: solution annealed, cold worked and artificially aged
2000 series
2000 series was formerly referred to as duralumin.
Applications
Aluminium-copper alloys are mainly used in , where their low corrosion resistance plays a subordinate role. Corrosion resistance can be greatly enhanced by the metallurgical bonding of a high-purity aluminium surface layer, referred to as alclad-duralum. To this day alclad materials are used commonly in the aircraft industry. The alloys are processed by rolling, forging, extrusion and partly by casting. Typical uses for wrought Al-Cu alloys include:
2011: Wire, rod, and bar for automatic lathe products. Applications where good machinability and good strength are required.
2014: Heavy-duty forgings, plate, and extrusions for aircraft fittings, wheels, and major structural components, space booster tankage and structure, truck frame and suspension components. Applications requiring high strength and hardness including service at elevated temperatures.
2017 or Avional (France): Around 1% Si. Good machinability. Acceptable resistance to corrosion in air and mechanical properties. Also called AU4G in France. Used for aircraft applications between the wars in France and Italy. Also saw some use in motor-racing applications from the 1960s, as it is a tolerant alloy that could be press-formed with relatively unsophisticated equipment.
2024: Aircraft structures, rivets, hardware, truck wheels, screw machine products, and other structural applications.
2036: Sheet for auto body panels
2048: Sheet and plate in structural components for aerospace application and military equipment
Aviation
German scientific literature openly published information about duralumin, its composition and heat treatment, before the outbreak of World War I in 1914. Despite this, use of the alloy outside Germany did not occur until after fighting ended in 1918. Reports of German use during World War I, even in technical journals such as Flight International, could still misidentify its key alloying component as magnesium rather than copper. Engineers in the UK showed little interest in duralumin only until after the war.
The earliest known attempt to use duralumin for a heavier-than-air aircraft structure occurred in 1916, when Hugo Junkers first introduced its use in the airframe of the Junkers J 3, a single-engined monoplane "technology demonstrator" that marked the first use of the Junkers trademark duralumin corrugated skinning. The Junkers company completed only the covered wings and tubular fuselage framework of the J 3 before abandoning its development. The slightly later, solely IdFlieg-designated Junkers J.I armoured sesquiplane of 1917, known to the factory as the Junkers J 4, had its all-metal wings and horizontal stabilizer made in the same manner as the J 3's wings had been, like the experimental and airworthy all-duralumin Junkers J 7 single-seat fighter design, which led to the Junkers D.I low-wing monoplane fighter, introducing all-duralumin aircraft structural technology to German military aviation in 1918.
Its first use in aerostatic airframes came in rigid airship frames, eventually including all those of the "Great Airship" era of the 1920s and 1930s: the British-built R-100, the German passenger Zeppelins LZ 127 Graf Zeppelin, LZ 129 Hindenburg, LZ 130 Graf Zeppelin II, and the U.S. Navy airships USS Los Angeles (ZR-3, ex-LZ 126), USS Akron (ZRS-4) and USS Macon (ZRS-5).
2000 series were once the most common aerospace alloys, but because they were susceptible to stress corrosion cracking, they are increasingly being replaced by 7000 series in new designs.
Bicycle
Duralumin was used to manufacture bicycle components and framesets from the 1930s to 1990s. Several companies in Saint-Étienne, France stood out for their early, innovative adoption of duralumin: in 1932, Verot et Perrin developed the first light alloy crank arms; in 1934, Haubtmann released a complete crankset; from 1935 on, Duralumin freewheels, derailleurs, pedals, brakes and handlebars were manufactured by several companies.
Complete framesets followed quickly, including those manufactured by: Mercier (and Aviac and other licensees) with their popular Meca Dural family of models, the Pelissier brothers and their race-worthy La Perle models, and Nicolas Barra and his exquisite mid-twentieth century “Barralumin” creations. Other names that come up here also included: Pierre Caminade, with his beautiful Caminargent creations and their exotic octagonal tubing, and also Gnome et Rhône, with its deep heritage as an aircraft engine manufacturer that also diversified into motorcycles, velomotors and bicycles after World War Two.
Mitsubishi Heavy Industries, which was prohibited from producing aircraft during the American occupation of Japan, manufactured the “cross” bicycle out of surplus wartime duralumin in 1946. The “cross” was designed by Kiro Honjo, a former aircraft designer responsible for the Mitsubishi G4M.
Duralumin use in bicycle manufacturing faded in the 1970s and 1980s. Vitus (bicycle company) nonetheless released the venerable “979” frameset in 1979, a “Duralinox” model that became an instant classic among cyclists. The Vitus 979 was the first production aluminium frameset whose thin-wall 5083/5086 tubing was slip-fit and then glued together using a dry heat-activated epoxy. The result was an extremely lightweight but very durable frameset. Production of the Vitus 979 continued until 1992.
References
Works cited
Further reading
David Laughlin, Kazuhiro Hono. Handbook of Aluminum: Vol. 1: Physical Metallurgy and Processes.
Aluminum Paperback - Volume 1. 16th edition, Aluminum Verlag, Düsseldorf 2002, pp. 101 f., 114–116, 121, 139–141
Friedrich Ostermann: Aluminum application technology. 3rd edition, Springer, 2014, , pp. 117–124
Aluminium alloys
Aluminium–copper alloys | Aluminium–copper alloys | [
"Chemistry"
] | 3,301 | [
"Alloys",
"Aluminium alloys"
] |
73,081,491 | https://en.wikipedia.org/wiki/AF%20Leporis | AF Leporis, also known as HD 35850, is a young variable star located away from the Solar System in the constellation of Lepus. With an apparent magnitude of 6.3, it is near the limit of naked eye visibility under ideal conditions. While some studies consider it to be a close spectroscopic binary with a separation of , other studies show no evidence of binarity, and it is likely that the supposed binarity is an artifact resulting from the presence of starspots. AF Leporis is a member of the Beta Pictoris moving group, with an astronomically young age of about 24 million years. It hosts a circumstellar disk and one known exoplanet.
The stellar classification of AF Leporis is F8V(n)k:, matching an F-type main-sequence star that is generating energy through hydrogen fusion at its core. (The 'n' indicates "nebulous" lines due to spin, while the 'k' means it displays interstellar absorption lines. The ':' suffix is used to note some uncertainty in the classification.) AF Leporis is classified as a RS Canum Venaticorum variable star, which means it has an active surface with large star spots that cause the net luminosity to vary as it rotates.
It is about 24 million years old and is spinning rapidly with a projected rotational velocity of around 50 km/s, giving it a rotation period of less than a day. The star has 9% more mass than the Sun and 1.25 times the Sun's radius. The abundance of elements with mass greater than hydrogen – the star's metallicity – is higher than in the Sun. AF Leporis is radiating 1.84 times the luminosity of the Sun from its photosphere at an effective temperature of 6,130 K.
Planetary system
In 2023, a super-Jupiter exoplanet, AF Leporis b, was discovered in orbit around AF Leporis by direct imaging using the NIRC2 instrument at the W. M. Keck Observatory and the SPHERE instrument at the Very Large Telescope. It was also detected in astrometric data from the Hipparcos and Gaia spacecraft, allowing an accurate measurement of its mass. AF Leporis b was later precovered in imaging data from 2011, allowing a more accurate determination of its orbit.
There have been multiple studies of AF Leporis b, which have found somewhat different parameters. Dynamical mass measurements range from to . Values for the planet's orbital inclination range from to , the former consistent with the stellar inclination of and suggesting an aligned system. Initial studies found a fairly eccentric orbit for the planet, but the precovery observations show that its orbit is nearly circular.
AF Leporis b has an effective temperature of about , corresponding to an early-T spectral type. Spectroscopic evidence suggests that it has a metal-rich atmosphere with silicate clouds, though further studies are needed to confirm this.
AF Leporis b was observed with JWST NIRCam. The brightness of F444W is relative faint, indicating significant absorption due to carbon monoxide (CO). The strong CO absorption is explained with disequilibrium chemistry and high metallicity. The observations also rule out additional giant planets in the outer region. The study did not find any variability of AF Leporis b. A study with VLT/GRAVITY confirmed many of the previous observations. The GRAVITY instrument did add high precision astrometry, while at the same time providing a K-band spectrum. The new astrometry together with previous observations was able to constrain the orbit to a circular orbit with an inclination that is aligned with the inclination of the rotation axis of the host star. The K-band spectrum shows prominent methane absorption. The spectrum is also consistent with a metal-rich cloudy atmosphere, with [Fe/H] = 0.75 ±0.25, consistent with the formation via core accretion. The temperature was constrained to 800 ±50 Kelvin. The dynamical mass constrained the planet mass to 3.75 ±0.5 .
See also
51 Eridani
Beta Pictoris
References
Lepus (constellation)
F-type main-sequence stars
RS Canum Venaticorum variables
Beta Pictoris moving group
Planetary systems with one confirmed planet
Circumstellar disks
1817
BD-12 1169
035850
025486
94945758
Leporis, AF | AF Leporis | [
"Astronomy"
] | 927 | [
"Lepus (constellation)",
"Constellations"
] |
73,081,805 | https://en.wikipedia.org/wiki/Superconcentrated%20electrolytes | Superconcentrated electrolytes, also known as water-in-salt or solvent-in-salt liquids, usually refer to chemical systems, which are liquid near room temperature and consist of a solvent-to-dissoved salt in a molar ratio near or smaller than ca. 4-8, i.e. where all solvent molecules are coordinated to cations, and no free solvent molecules remain. Since ca. 2010 such liquid electrolytes found several applications, primarily for batteries. In the case of lithium metal batteries and lithium-ion batteries most commonly used anions for superconcentrated electrolytes are those, that are large, asymmetric and rotationally-vibrationally flexible, such as bis(trifluoromethanesulfonyl)amide and bis(fluorosulfonyl)amide. Noteworthy, lithium chloride and sodium perchlorate also form water-in-salt solutions.
Advantages
Superconcentrated electrolytes demonstrate the following advantages:
(1) Many show a good oxidative stability. In particular, some can suppress oxidative corrosion of an Al current collector without a source of fluoride ion (such as hexafluorophosphate) and enable the use of 5 V lithium-ion battery cathode materials.
(2) Some are resistant to electrochemical reduction. It is believed, that some sulfonimides (e.g., those with S-F and F-(H)C-N fragments, form a solid electrolyte interface similar to that formed by some organic carbonate solvents. Properties #1 and #2 are responsible for very large (4-5 volt) voltage window, which is useful for advanced batteries.
(3) Related to #2 is the ability of some superconcentrated electrolytes to allow for reversible intercalation of Li+ ions into graphite in the absence of ethylene carbonate solvent, therefore enabling a new class of safer lithium-ion batteries.
(4) Solvent vapor pressure is lower, thermal stability is higher, and flammability is absent, which contributes to a better battery safety.
(5) The concentration of charge-carrying ion is larger, which translates into smaller ion travelling distances.
(6) In some cases, and contrary to expectations, faster rates of electrode reactions are observed, than in conventional low-salt-concentration electrolytes.
(7) Polysulfide dissolution is sometimes suppressed, which enables cycling of such batteries as lithium-sulfur.
(8) Some studies report, that Li+ transference number in such liquids is close to one, which means, that Li+ concentration gradient between anode and cathode does not develop during the battery's charge and discharge.
(9) Electrodeposition of lithium metal from superconcentrated electrolytes is often nodular (without dendrites) and reversible.
Disadvantages
At the same time, highly concentrated electrolytes are not without disadvantages:
(1) Their ionic conductivity is generally lower than that of corresponding dilute (~1 M) electrolytes.
(2) Their viscosity is higher than that of conventional electrolytes.
(3) Their cost is usually higher, because manufacturing of some anions, such as sulfonimides, requires several low-yield synthetic steps.
Origin of the unusual properties
The exact mechanism of high-voltage stability of superconcentrated electrolytes have not been established as of 2023. The two main proposed mechanisms are:
(1) a decrease of water molecules' thermodynamic activity, when all water molecules are coordinated to cations, such as Li+.
(2) decomposition of an anion with the formation of a solid electrolyte interface.
Most recent studies suggest, that the anion decomposition mechanism (2) dominates in a majority of cases.
References
Solutions
Electric battery | Superconcentrated electrolytes | [
"Chemistry"
] | 804 | [
"Homogeneous chemical mixtures",
"Solutions"
] |
73,082,093 | https://en.wikipedia.org/wiki/Dimension%20doubling%20theorem | In probability theory, the dimension doubling theorems are two results about the Hausdorff dimension of an image of a Brownian motion. In their core both statements say, that the dimension of a set under a Brownian motion doubles almost surely.
The first result is due to Henry P. McKean jr and hence called McKean's theorem (1955). The second theorem is a refinement of McKean's result and called Kaufman's theorem (1969) since it was proven by Robert Kaufman.
Dimension doubling theorems
For a -dimensional Brownian motion and a set we define the image of under , i.e.
McKean's theorem
Let be a Brownian motion in dimension . Let , then
-almost surely.
Kaufman's theorem
Let be a Brownian motion in dimension . Then -almost surely, for any set , we have
Difference of the theorems
The difference of the theorems is the following: in McKean's result the -null sets, where the statement is not true, depends on the choice of . Kaufman's result on the other hand is true for all choices of simultaneously. This means Kaufman's theorem can also be applied to random sets .
Literature
References
Wiener process
Probability theorems | Dimension doubling theorem | [
"Mathematics"
] | 257 | [
"Theorems in probability theory",
"Mathematical theorems",
"Mathematical problems"
] |
73,082,266 | https://en.wikipedia.org/wiki/Aluminium%E2%80%93scandium%20alloys | Aluminium–scandium alloys (AlSc) are aluminum alloys that consist largely of aluminium (Al) and traces of scandium (Sc) as the main alloying elements. In principle, aluminium alloys strengthened with additions of scandium are very similar to traditional nickel-base superalloys in that both are strengthened by coherent, coarsening resistant precipitates with an ordered L12 structure. But Al–Sc alloys contain a much lower volume fraction of precipitates, and the inter-precipitate distance is much smaller than in their nickel-base counterparts. In both cases however, the coarsening resistant precipitates allow the alloys to retain their strength at high temperatures.
Composition
The addition of scandium to aluminium limits grain growth in the heat-affected zone of welded aluminium components. This has two beneficial effects: the precipitated forms smaller crystals than in other aluminium alloys, and the volume of precipitate-free zones at the grain boundaries of age-hardening aluminium alloys is reduced. Scandium is also a potent grain refiner in cast aluminium alloys, and atom for atom, the most potent strengthener in aluminium, both as a result of grain refinement and precipitation strengthening.
The precipitate is a coherent precipitate that strengthens the aluminum matrix by applying elastic strain fields that inhibit dislocation movement (i.e., plastic deformation). An added benefit of scandium additions to aluminum is that the nanoscale Al3Sc precipitates that give the alloy its strength are coarsening resistant at relatively high temperatures (~350 °C). This is in contrast to typical commercial 2xxx and 6xxx alloys, which quickly lose their strength at temperatures above 250 °C due to the rapid coarsening of their strengthening precipitates. The Al3Sc precipitates also increase the yield strength of aluminum alloys by .
has an equilibrium L12 superlattice structure. A fine dispersion of nano-scale precipitate can be achieved via heat treatment that can also strengthen the alloys through order hardening.
Recent developments include the additions of transition metals such as Zr and rare earth metals like Er to produce shells surrounding the spherical precipitate that has been shown to increase the coarsening resistance of Al-Sc alloys to ~400 °C. The additions form strengthening precipitates with composition Al3(Sc,Zr,Er). These shells are dictated by the diffusivity of the alloying element and lower the cost of the alloy due to less Sc being substituted in part by Zr while maintaining stability and less Sc being needed to form the precipitate. These efforts led by Profs. Seidman and Dunand at Northwestern University, as well as others in the field, resulted in pioneering aluminum superalloys strengthened with core-shell L12-structured nanoprecipitates, an f.c.c./L12 dual-phase alloy. These alloys are somewhat competitive with titanium alloys for a wide array of applications. The alloy is as strong as titanium, as light as aluminum, and as hard as some ceramics. However, titanium alloys, which are similar in lightness and strength, are cheaper and much more widely used.
Since 2013, Apworks GmbH, a spin-off of Airbus, has marketed a high-strength Scandium containing aluminium alloy processed using metal 3D-Printing (Laser Powder Bed Fusion) under the trademark Scalmalloy which claims very high strength & ductility.
Applications
The main application of metallic scandium by weight is in aluminium–scandium alloys for minor aerospace industry components. These alloys contain between 0.1% and 0.5% (by weight) of scandium. They were used in the Russian military, specifically the Mikoyan-Gurevich MiG-21 and MiG-29.
The increased operating temperature of Al-Sc alloys has significant implications for energy efficient applications, particularly in the automotive industry. These alloys can provide a replacement for denser materials such as steel and titanium that are used in 250–350 °C environments, such as in or near engines. Replacement of these materials with lighter aluminium alloys leads to weight reductions which in turn leads to increased fuel efficiencies.
Some items of sports equipment, which rely on lightweight high-performance materials, have been made with scandium-aluminium alloys, including baseball bats, tent poles and bicycle frames and components. Lacrosse sticks are also made with scandium.
The American firearm manufacturing company Smith & Wesson produces semi-automatic pistols and revolvers with frames of scandium alloy and cylinders of titanium or carbon steel.
References
Further reading
Dorin, Thomas; Ramajayam, Mahendra; Vahid, Alireza; Langan, Timothy (2018), "Aluminium Scandium Alloys", Fundamentals of Aluminium Metallurgy, Elsevier, pp. 439–494
Røyset, J.; Ryum, N. (2005-02-01). "Scandium in aluminium alloys". International Materials Reviews. 50 (1): 19–44. doi:10.1179/174328005X14311. ISSN 0950-6608
Shevchenko, M. O.; Kudin, V. G.; Berezutskii, V. V.; Ivanov, M. I.; Sudavtsova, V. S. (2014-07-01). "Thermodynamic Properties of Al–Sc Alloys". Powder Metallurgy and Metal Ceramics. 53 (3): 243–249. doi:10.1007/s11106-014-9610-6. ISSN 1573-9066 | Aluminium–scandium alloys | [
"Chemistry"
] | 1,173 | [
"Alloys",
"Aluminium alloys"
] |
73,082,555 | https://en.wikipedia.org/wiki/List%20of%20phishing%20incidents | The list of phishing incidents covers important or noteworthy events in the history of phishing.
1980s
1984
An early phishing incident was documented at the New Jersey Institute of Technology (NJIT). In an article titled "Life in a Wired Society" in Omni magazine, Murray Turoff challenged a 'sandy-haired whiz kid', Bob Michie, to find a vulnerability in NJIT's EIES computer system. The resulting discovery was part of a sanctioned operation and could be considered one of the earliest documented successful phishing attempts.
1987
A phishing technique was described in detail in a paper and presentation delivered to the 1987 International HP Users Group, Interex.
1990s
The term "phishing" is said to have been coined by the well known spammer and hacker in the mid-90s, Khan C. Smith. The first recorded mention of the term is found in the hacking tool AOHell (according to its creator), which included a function for attempting to steal the passwords or financial details of America Online users.
1995
Phishing on AOL was a technique used by the warez community, who traded in unlicensed software, and black hat hackers to steal credit card information and commit other online crimes. AOL would suspend the accounts of individuals caught using certain keywords in chat rooms related to counterfeiting software or stolen accounts. The term "phishing" originated from the use of the <>< symbol in chat transcripts as a way to disguise references to illegal activity and evade detection by AOL staff. The symbol resembled a fish, and, combined with the popularity of phreaking, led to the term "phishing." AOHell, a program released in 1995, allowed hackers to impersonate AOL staff and send instant messages to victims asking them to reveal their passwords by claiming to need to "verify your account" or "confirm billing information". AOHell was a custom-written program used for phishing and warezing on AOL. In an effort to combat phishing, AOL added a warning to all instant messages stating that they would never ask for passwords or billing information. However, users with both AOL and non-AOL internet accounts (such as those from an ISP) could still phish AOL members without consequences. In 1995, AOL implemented measures to prevent the use of fake credit card numbers to open accounts, leading to an increase in phishing for legitimate accounts. AOL deactivated accounts involved in phishing, and eventually the warez scene on AOL was shut down, causing most phishers to leave the service.
2000s
2001
The first known direct attempt against a payment system affected E-gold in June 2001, which was followed up by a "post-9/11 id check" shortly after the September 11 attacks on the World Trade Center.
2003
The first known phishing attack against a retail bank was reported by The Banker in September 2003.
2004
It is estimated that between May 2004 and May 2005, approximately 1.2 million computer users in the United States suffered losses caused by phishing, totaling approximately . United States businesses lose an estimated per year as their clients become victims.
Phishing is recognized as a fully organized part of the black market. Specializations emerged on a global scale that provided phishing software for payment (thereby outsourcing risk), which were assembled and implemented into phishing campaigns by organized gangs.
2005
In the United Kingdom losses from web banking fraud—mostly from phishing—almost doubled to in 2005, from in 2004, while 1 in 20 computer users claimed to have lost out to phishing in 2005.
2006
Almost half of phishing thefts in 2006 were committed by groups operating through the Russian Business Network based in St. Petersburg.
Banks dispute with customers over phishing losses. The stance adopted by the UK banking body APACS is that "customers must also take sensible precautions ... so that they are not vulnerable to the criminal." Similarly, when the first spate of phishing attacks hit the Irish Republic's banking sector in September 2006, the Bank of Ireland initially refused to cover losses suffered by its customers, although losses to the tune of €113,000 were made good.
Phishers are targeting the customers of banks and online payment services. Emails, supposedly from the Internal Revenue Service, have been used to glean sensitive data from U.S. taxpayers. While the first such examples were sent indiscriminately in the expectation that some would be received by customers of a given bank or service, recent research has shown that phishers may in principle be able to determine which banks potential victims use, and target bogus emails accordingly.
Social networking sites are a prime target of phishing, since the personal details in such sites can be used in identity theft; in late 2006 a computer worm took over pages on MySpace and altered links to direct surfers to websites designed to steal login details.
2007
3.6 million adults lost in the 12 months ending in August 2007. Microsoft claims these estimates are grossly exaggerated and puts the annual phishing loss in the US at .
Attackers who broke into TD Ameritrade's database and took 6.3 million email addresses (though they were not able to obtain social security numbers, account numbers, names, addresses, dates of birth, phone numbers and trading activity) also wanted the account usernames and passwords, so they launched a follow-up spear phishing attack.
2008
The RapidShare file sharing site has been targeted by phishing to obtain a premium account, which removes speed caps on downloads, auto-removal of uploads, waits on downloads, and cool down times between uploads.
Cryptocurrencies such as Bitcoin facilitate the sale of malicious software, making transactions secure and anonymous.
2009
In January 2009, a phishing attack resulted in unauthorized wire transfers of US$1.9 million through Experi-Metal's online banking accounts.
In the third quarter of 2009, the Anti-Phishing Working Group reported receiving 115,370 phishing email reports from consumers with US and China hosting more than 25% of the phishing pages each.
2010s
2011
In March 2011, Internal RSA staff were successfully phished, leading to the master keys for all RSA SecurID security tokens being stolen, then subsequently used to break into US defense suppliers.
Chinese phishing campaigns targeted Gmail accounts of highly ranked officials of the United States and South Korean governments and militaries, as well as Chinese political activists.
2012
According to Ghosh, there were "445,004 attacks in 2012 as compared to 258,461 in 2011 and 187,203 in 2010".
2013
In August 2013, advertising service Outbrain suffered a spear-phishing attack and SEA placed redirects into the websites of The Washington Post, Time, and CNN.
In October 2013, emails purporting to be from American Express were sent to an unknown number of recipients.
In November 2013, 110 million customer and credit card records were stolen from Target customers, through a phished subcontractor account. CEO and IT security staff subsequently fired.
By December 2013, Cryptolocker ransomware had infected 250,000 computers. According to Dell SecureWorks, 0.4% or more of those infected likely agreed to the ransom demand.
2014
In January 2014, the Seculert Research Lab identified a new targeted attack that used Xtreme RAT. This attack used spear phishing emails to target Israeli organizations and deploy the piece of advanced malware. Fifteen machines were compromised including ones belonging to the Civil Administration of Judea and Samaria.
In August 2014, the iCloud leaks of celebrity photos was found to be based on phishing e-mails sent to the victims that looked like they came from Apple or Google, warning the victims that their accounts might be compromised and asking for their account details.
In November 2014, phishing attacks on ICANN gained administrative access to the Centralized Zone Data System; also gained was data about users in the system – and access to ICANN's public Governmental Advisory Committee wiki, blog, and whois information portal.
2015
Charles H. Eccleston pleaded guilty in an attempted spear-phishing when he attempted to infect computers of 80 Department of Energy employees.
Eliot Higgins and other journalists associated with Bellingcat, a group researching the shootdown of Malaysia Airlines Flight 17 over Ukraine, were targeted by numerous spear phishing emails.
In August 2015, Cozy Bear was linked to a spear-phishing cyber-attack against the Pentagon email system causing the shut down of the entire Joint Staff unclassified email system and Internet access during the investigation.
In August 2015, Fancy Bear used a zero-day exploit of Java, in a spear phishing attack spoofing the Electronic Frontier Foundation and launching attacks on the White House and NATO.
2016
In February, Austrian aerospace firm FACC AG was defrauded of 42 million euros ($47 million) through a BEC attack – and subsequently fired both the CFO and CEO.
Fancy Bear carried out spear phishing attacks on email addresses associated with the Democratic National Committee in the first quarter of 2016.
The Wichita Eagle reported "KU employees fall victim to phishing scam, lose paychecks"
Fancy Bear is suspected to be behind a spear phishing attack in August 2016 on members of the Bundestag and multiple political parties such as Linken-faction leader Sahra Wagenknecht, Junge Union and the CDU of Saarland.
In August 2016, the World Anti-Doping Agency reported the receipt of phishing emails sent to users of its database claiming to be official WADA, but consistent with the Russian hacking group Fancy Bear. According to WADA, some of the data the hackers released had been forged.
Within hours of the 2016 U.S. election results, Russian hackers sent emails from spoofed Harvard University email addresses, using techniques similar to phishing to publish fake news targeted at ordinary American voters.
2017
In 2017, 76% of organizations experienced phishing attacks. Nearly half of information security professionals surveyed said that the rate of attacks increased from 2016.
In the first half of 2017 businesses and residents of Qatar were hit with more than 93,570 phishing events in a three-month span.
A phishing email to Google and Facebook users successfully induced employees into wiring money – to the extent of US$100 million – to overseas bank accounts under the control of a hacker. He has since been arrested by the US Department of Justice.
In August 2017, customers of Amazon faced the Amazon Prime Day phishing attack, when hackers sent out seemingly legitimate deals to customers of Amazon. When Amazon's customers attempted to make purchases using the "deals", the transaction would not be completed, prompting the retailer's customers to input data that could be compromised and stolen.
2018
In 2018, the company block.one, which developed the EOS.IO blockchain, was attacked by a phishing group who sent phishing emails to all customers, aimed at intercepting the user's cryptocurrency wallet key; and a later attack targeted airdrop tokens.
2019
Between May 30, 2019, and October 6, 2019, an unauthorized individual gained access to employee email accounts at Golden Entertainment, a Las Vegas, Nevada slot machine operator using an email phishing attack. The attacker had access to one particular email with an attachment containing the Social Security Numbers, Passport numbers, government IDs, and various personal data of multiple company employees and vendors. It is unclear whether this information was exposed. The company notified all affected individuals as a precaution, offering them complimentary Credit report monitoring. Subsequently, a class action lawsuit against the company was approved in the United States District Court for the District of Nevada on December 17, 2020.
From 2015 to 2019, Unatrac Holding Ltd. was subjected to an ongoing spear phishing attack, costing about US$11 million. Obinwanne Okeke and conspirators first acquired the company CFO's email credentials. Then, they sent fake invoices and wire transfer requests to the company's financial department. Okeke perpetrated cyberfraud against many other businesses and individuals, successfully capturing email and other sensitive login credentials. On February 16, 2021, he was sentenced to 10 years in prison.
2020s
2020
On July 15, 2020, Twitter suffered a breach that combined elements of social engineering and phishing. A 17-year-old hacker and accomplices set up a fake website resembling Twitter's internal VPN provider used by remote working employees. Individuals posing as helpdesk staff called multiple Twitter employees, directing them to submit their credentials to the fake VPN website. Using the details supplied by the unknowing employees, they were then able to seize control of several high-profile user accounts, including Barack Obama, Elon Musk, Joe Biden and Apple Inc.'s company account. The hackers sent messages to Twitter followers soliciting Bitcoin promising double the transaction value in return, collecting 12.86 BTC (about $117,000 at the time).
Overview
See also
List of cyberattacks
List of data breaches
List of security hacking incidents
References
Spamming
Internet terminology
Organized crime activity
Social engineering (security)
Cybercrime
Confidence tricks
Identity theft
Types of cyberattacks
Deception
Fraud | List of phishing incidents | [
"Technology"
] | 2,745 | [
"Computing terminology",
"Internet terminology"
] |
73,083,495 | https://en.wikipedia.org/wiki/Australian%20meat%20substitution%20scandal | The Australian meat substitution scandal of 1981 involved the widespread substitution of horse meat and kangaroo meat for beef in Australia. While the substitution primarily affected meat exported overseas, particularly to the United States, further investigations revealed that these, as well as donkey meat and pet food, had been packaged for human consumption and non-halal meat was sold as halal meat domestically in Australia.
Background
Claims that meat processing companies in Victoria were substituting other types of meat for beef were brought before the Parliament of Australia by Cyril Primmer in 1977. Ian Sinclair, then Minister of Primary Industry, later announced that a police investigation of Primmer's claims found no evidence of meat substitution. Allegations of meat substitution were made in both the Australian parliament and the Parliament of Victoria over the following years. However, these claims were not seriously investigated by police.
Investigation
The scandal unraveled on 27 July 1981 after a food inspector in San Diego, California, became suspicious of three blocks of frozen Australian boneless beef that were "darker and stringier" than beef should be. Tests revealed that they were horse meat, not beef, and further testing elsewhere in the United States revealed that some Australian "beef" contained kangaroo meat. Some of the meat had found its way into burgers at the Jack in the Box chain, leading to jokes about "Skippy burgers".
In response, the United States Department of Agriculture imposed stringent inspections on Australian beef imports. In 1982, the Australian government launched the Royal Commission into Australian meat industry to investigate. Exports of meat from processing plants in Victoria were also suspended for 30 days. The commission investigated 35 companies and released a report on its findings in September 1982. The commission found that "malpractices in the nature of commercial cheating have been widespread in the export industry." The report stated that companies routinely falsified packing dates and description of meats. It also found that a perception existed in the industry that this was tolerated by inspectors.
However, Appendix H of the report was not published at the time, and was only made available to the public in 2012, nearly 30 years later, after a Freedom of Information request first made by the Canberra Times in December 1982 was finally successful. The appendix noted that:
Several meat distributors in Australia were found to have purchased low-grade cuts of meat intended for pet food, which they then repackaged and exported for human consumption. Non-halal meat was also substituted for halal meat. Justice Woodward noted that the scale of the operation could not be properly assessed due to attempts to cover it up, but said that the types of meat used as substitutes would be easily obtained in the eastern states of Australia.
Meat substitution was confirmed to have been occurring for at least five years. Sources within Victoria Police claimed that meat processors were being warned when to expect quality inspections by American officials.
A 1981 article in The Washington Post noted that the condition of kangaroos processed for meat did not meet United States standards. In particular, it stated that kangaroos were typically hunted in the field, and then transported hundreds of miles by truck to be processed. The royal commission's report also noted unhygienic conditions at slaughterhouses, including poor cleanliness and the presence of maggots at a slaughterhouse in Katherine, Northern Territory.
Consequences
Ten companies referenced in the appendix had their food-export licenses revoked, effectively shutting nine of them down. Penalties for breaching export-license conditions were also increased from $2,000 to $100,000. The maximum fine at the time, though, for the perpetrators themselves was only $100. Richard V. Hammon, a principal at Profreeze, was convicted of "forging documents issued by or deliverable to Commonwealth authorities" and sentenced to four years in prison.
The scandal led to widespread criticism in Australia of the government and federal police. Critics of Prime Minister Malcolm Fraser claimed that his administration had failed to respond to the scandal until it reached international proportions. Australian Labor Party called for the resignation of Peter Nixon, the Minister of Primary Industry at the time of the scandal. Detractors of Nixon nicknamed the scandal "Slaughtergate", a reference to the Watergate scandal involving US President Richard Nixon.
At the time, concerns arose that the scandal would affect the beef-exporting industry, as the United States was the largest importer of Australian beef. It also affected Australian exports to Singapore and countries in the Middle East. This led to a series of reforms in Australian industry regulations. The 1982 Export Control Act was introduced to regulate the export of meat in the aftermath of the scandal. It introduced new legal requirements for meat-processing operations and required exporters to meet the food standards of countries importing their meat, in addition to Australian standards. The Australian Bureau of Animal Health was replaced by the Export Inspection Service (EIS) in 1982, eventually becoming part of the current Australian Quarantine and Inspection Service.
References
Meat substitution scandal
1981 scandals
July 1981 events in Oceania
Adulteration
Food recalls
Food safety scandals
Scandals in Australia
Jack in the Box
Australia–United States relations | Australian meat substitution scandal | [
"Chemistry"
] | 1,020 | [
"Adulteration",
"Drug safety"
] |
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