text
stringlengths 2
132k
| source
dict |
|---|---|
Arthur Eichengrün (13 August 1867 – 23 December 1949) was a German Jewish chemist, materials scientist, and inventor. He is known for developing the highly successful anti-gonorrhea drug Protargol, the standard treatment for 50 years until the adoption of antibiotics, and for his pioneering contributions in plastics: co-developing (with Theodore Becker) the first soluble cellulose acetate materials in 1903, called "Cellit", and creating processes for the manufacture of these materials which were influential in the development of injection moulding. During World War I his relatively non-flammable synthetic cellulose acetate lacquers, marketed under the name "Cellon", were important in the aircraft industry. He contributed to photochemistry by inventing the first process for the production and development of cellulose acetate film, which he patented with Becker. Eichengrün claimed to have directed the initial synthesis of aspirin in 1897, but his claim has been disputed. For many years Bayer credited Felix Hoffmann, Eichengrün's junior, with the invention of aspirin. However, according to some historians the first attribution of the discovery to Hoffmann appears in 1934, and may have reflected anti-Jewish revisionism. Nonetheless, Bayer has denied these claims indicating that Hoffman already figured as the inventor in the American patent of aspirin filed in 1899. During World War II, Eichengrün was imprisoned in the Theresienstadt concentration camp. == Life == Arthur Eichengrün was born in Aachen as the son of a Jewish cloth merchant and manufacturer. In 1885, he took up studies in chemistry at the University of Aachen, later moved to Berlin, and finally to Erlangen, where he received a doctoral degree in 1890. In 1896, he joined Bayer, working in the pharmaceutical laboratory. In 1908, he quit Bayer and founded his own pharmaceutical factory, the Cellon-Werke in Berlin. His company was "Aryanized" by the Nazis in 1938. In 1943, he was arrested
|
{
"page_id": 529207,
"source": null,
"title": "Arthur Eichengrün"
}
|
and sentenced to four months in prison for having failed to include the word "Israel" in his name in a letter to a Reich official (Nazi law required Jewish men to be identified as such, as they required Jewish women to identify as "Sarah".). In May 1944, he was arrested again on the same charge and deported to the concentration camp Theresienstadt, where he spent 14 months until the end of World War II in Europe, escaping death. After the liberation, he returned to Berlin, but moved to Bad Wiessee in Bavaria in 1948, where he died the following year at the age of 82. == Work == === Aspirin === Eichengrün has made his name through numerous inventions, such as processes for synthesizing chemical compounds. Aside from Aspirin, Eichengrün held 47 patents. Bayer's official story credits Felix Hoffmann, a young Bayer chemist, with the invention of aspirin in 1897. Impure acetylsalicylic acid (ASA, the active compound of aspirin) had been synthesized already in 1853 by French chemist Charles Frédéric Gerhardt; the 1897 process developed at Bayer was the first to produce pure ASA that could be used for medical purposes. Due to the rise of the Nazis in Germany, Eichengrün was unable to object when Hoffmann first made the claim that he (Hoffman) invented aspirin, in the footnote of a 1934 German Encyclopedia. Hoffmann's claim was once widely accepted, but many historians now consider it to be discredited. Eichengrün first claimed to have invented aspirin in a 1944 letter from Theresienstadt concentration camp, addressed to IG Farben (of which Bayer was a part), where he cited his many contributions to the company (which was highly influential in the concentration camps), including the invention of aspirin, as reasons for why he should be released. Five years later, Arthur Eichengrün published
|
{
"page_id": 529207,
"source": null,
"title": "Arthur Eichengrün"
}
|
a paper in Pharmazie in 1949, where he explained that he had instructed Hoffmann to synthesise acetylsalicylic acid and that the latter had done so without knowing the purpose of the work. The paper elucidated how he planned and directed the synthesis of aspirin along with the synthesis of several related compounds, describing these events in detail. He also claimed to be responsible for aspirin's initial surreptitious clinical testing. Finally, he explained that Hoffmann's role was restricted to the initial lab synthesis using his (Eichengrün's) process and nothing more. Eichengrün's account was largely ignored by historians and chemists until 1999, when Walter Sneader of the Department of Pharmaceutical Sciences at the University of Strathclyde in Glasgow re-examined the case and came to the conclusion that indeed Eichengrün's account was convincing and correct and that Eichengrün deserved credit for the invention of aspirin. Bayer denied this in a press release, asserting that the invention of aspirin was due to Hoffmann. Evidence supporting Eichengrün's claims to the invention Walter Sneader based his claims that Eichengrün both invented the process for synthesizing aspirin and oversaw its clinical testing on old and newly released archived materials, including letters, patents, and lab work. He found that Hoffmann was not credited with inventing the process for synthesizing Aspirin in any documents prior to 1934, 37 years after its initial synthesis. Further he found reason to doubt the footnote's credibility, not just for being published during the "Aryanization" period of Nazi Germany, but for its inaccurate claims about the testing of salicylic acid derivates other than acetyl ester. The vague reference did not specify which derivatives were tested, but claimed they had been discovered earlier but had been synthesized for "other purposes". No indication was given of what the others were, but in 1899 Heinrich Dreser, head
|
{
"page_id": 529207,
"source": null,
"title": "Arthur Eichengrün"
}
|
of the experimental pharmacology laboratory at Elberfeld, named them in a publication as propionyl, butyryl, valeryl, and benzoyl salicylic acids. He further alluded to these derivatives in 1907 and again in 1918. However, the assertion that these salicylic acid derivates had been synthesized for non-therapeutic reasons is demonstrably false. Hoffmann's colleague Otto Bonhoeffer (who also worked under Eichengrün) had been awarded a US and UK patent in 1900 for several of these compounds. The patents indicate that the derivatives were prepared for the exact purpose of finding a salicylic acid derivative with therapeutic value. Sneader concluded that because of this error the 1934 footnote is unreliable. However Bayer dismissed Sneader claims asserting Hoffman invention of the Aspirin. According to Bayer, Hoffmann and Eichengrün were colleagues of equal standing at Bayer, not in a hierarchical relationship. This undermines Sneader's claim that Hoffmann worked under Eichengrün's direction. Numerous documents, including Hoffmann's laboratory journal entry from August 10, 1897, explicitly record his synthesis of ASA, providing clear evidence of his role in this pivotal discovery. Additionally, Hoffmann is recognized as the inventor in the American patent for ASA, filed in 1899. Notably, Eichengrün never contested this acknowledgment during his tenure at Bayer, further solidifying Hoffmann’s claim to the invention. Eichengrün’s assertions lack timely credibility, as he did not claim credit for the synthesis until 1949—more than 50 years after Hoffmann's documented work. This delay raises questions about the validity of his late claims to authorship. Furthermore, the narrative suggesting that Eichengrün's Jewish background led to the suppression of his contributions lacks substantive evidence. Throughout his career, Eichengrün was a successful inventor with numerous patents and never demanded recognition for ASA during his time at Bayer. === Protargol === In 1897, protargol, a silver salt of a protein mixture, developed by Eichengrün at Bayer,
|
{
"page_id": 529207,
"source": null,
"title": "Arthur Eichengrün"
}
|
was introduced as a new drug against gonorrhea. Protargol stayed in use until sulfa drugs and then antibiotics became available in the 1940s. === Plastics === In 1903, Eichengrün co-developed the first soluble form of cellulose acetate with Theodore Becker. He developed processes for the manufacture of cellulose acetate materials and devoted the rest of his life to the technical and economic development of plastics, lacquers, enamels, and artificial fibers based on cellulose acetate. During World War I his relatively non-inflammable synthetic cellulose acetate lacquers were important in the aircraft industry. He also pioneered the influential technique of injection moulding. In 1904, he created and patented the first safety film with Becker, (cellulose diacetate) from a process they devised in 1901 for the direct acetylation of cellulose at a low temperature to prevent its degradation, which permitted the degree of acetylation to be controlled, thereby avoiding total conversion to its triacetate. Cellit was a stable, non-brittle cellulose acetate polymer that could be dissolved in acetone for further processing. It was used to manufacture cellulose diacetate cinematographic film, which Eastman Kodak and the Pathé Frères began to use in 1909. Cellulose acetate film became the standard in the 1950s, preferred over the highly flammable and unstable film stock produced from Nitrocellulose. == References == == External links == Arthur Eichengrün in the Complete Dictionary of Scientific Biography Sneader's paper crediting Eichengrün with the invention of aspirin in the British Medical Journal. Bayer's press release denying this at the Wayback Machine (archived September 28, 2007) (in German) Wer hat es erfunden? (Who invented it?) (in German) Gratzer, Walter (2002). "Truth Stranger than Fiction". Eurekas and Euphorias; The Oxford Book of Scientific Anectodes. New York: Oxford University Press. pp. 209-210. ISBN 978-0-19-280403-7. Retrieved December 12, 2018 – via Internet Archive.
|
{
"page_id": 529207,
"source": null,
"title": "Arthur Eichengrün"
}
|
Ayanna Williams is an American who holds the world record for the longest fingernails ever reached on a single hand for a woman, with a combined length of 576.4 centimeters (181.09 inches). She is also ranked second in the list of having longest fingernails in the world considering both genders, just behind India's Shridhar Chillal who had a combined length of 909.6 centimeters (358.1 inches). Ayanna was awarded the Guinness World Record in 2018 for being the woman with the longest finger nails in the world. == Biography == Ayanna pursued her interest in growing nails and engaged in nail art during her young age as a kid. She spent over 2 months to grow her nails without cutting them. Although proud of her record-breaking nails, Ayanna has faced increasing difficulties due to the weight of her finger nails. She found difficulties when engaging in day-to-day activities such as washing plates, dishes and putting sheets on bed. In 2021, she decided to cut her nails. On 9 April 2021, she had her fingernails cut by Allison Readinger of Trinity Vista Dermatology using an electronic rotary power tool at the Ripley's Believe It or Not! museum in New York City, where the nails had been put on display for public. The nails were measured for one last time in 2021 and the reading marked as 733.55 centimeters (240.7 inches) before cutting them down. == See also == Lee Redmond, who held the record for the longest fingernails on both hands. == References ==
|
{
"page_id": 67375932,
"source": null,
"title": "Ayanna Williams"
}
|
The blue whale (Balaenoptera musculus) is a marine mammal and a baleen whale. Reaching a maximum confirmed length of 29.9 m (98 ft) and weighing up to 199 t (196 long tons; 219 short tons), it is the largest animal known ever to have existed. The blue whale's long and slender body can be of various shades of greyish-blue on its upper surface and somewhat lighter underneath. Four subspecies are recognized: B. m. musculus in the North Atlantic and North Pacific, B. m. intermedia in the Southern Ocean, B. m. brevicauda (the pygmy blue whale) in the Indian Ocean and South Pacific Ocean, and B. m. indica in the Northern Indian Ocean. There is a population in the waters off Chile that may constitute a fifth subspecies. In general, blue whale populations migrate between their summer feeding areas near the poles and their winter breeding grounds near the tropics. There is also evidence of year-round residencies, and partial or age/sex-based migration. Blue whales are filter feeders; their diet consists almost exclusively of krill. They are generally solitary or gather in small groups, and have no well-defined social structure other than mother–calf bonds. Blue whales vocalize, with a fundamental frequency ranging from 8 to 25 Hz; their vocalizations may vary by region, season, behavior, and time of day. Orcas are their only natural predators. The blue whale was abundant in nearly all the Earth's oceans until the end of the 19th century. It was hunted almost to the point of extinction by whalers until the International Whaling Commission banned all blue whale hunting in 1966. The International Union for Conservation of Nature has listed blue whales as Endangered as of 2018. It continues to face numerous man-made threats such as ship strikes, pollution, ocean noise, and climate change. Scientists found evidence
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
of this through morphological or epidemiological analysis. These analyses are accompanied by chemical profiles that use fecal and tissue which continue to prove the impact of man-made threats. == Taxonomy == === Nomenclature === The genus name, Balaenoptera, means winged whale, while the species name, musculus, could mean "muscle" or a diminutive form of "mouse", possibly a pun by Carl Linnaeus when he named the species in Systema Naturae. One of the first published descriptions of a blue whale comes from Robert Sibbald's Phalainologia Nova, after Sibbald found a stranded whale in the estuary of the Firth of Forth, Scotland, in 1692. The name "blue whale" was derived from the Norwegian blåhval, coined by Svend Foyn shortly after he had perfected the harpoon gun. The Norwegian scientist G. O. Sars adopted it as the common name in 1874. Blue whales were referred to as "Sibbald's rorqual", after Robert Sibbald, who first described the species. Whalers sometimes referred to them as "sulphur bottom" whales, as the bellies of some individuals are tinged with yellow. This tinge is due to a coating of huge numbers of diatoms. (Herman Melville briefly refers to "sulphur bottom" whales in his novel Moby-Dick.) === Evolution === Blue whales are rorquals in the family Balaenopteridae. A 2018 analysis estimates that the Balaenopteridae family diverged from other families in between 10.48 and 4.98 million years ago during the late Miocene. The earliest discovered anatomically modern blue whale is a partial skull fossil from southern Italy identified as B. cf. musculus, dating to the Early Pleistocene, roughly 1.5–1.25 million years ago. The Australian pygmy blue whale diverged during the Last Glacial Maximum. Their more recent divergence has resulted in the subspecies having a relatively low genetic diversity, and New Zealand blue whales have an even lower genetic diversity. Whole
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
genome sequencing suggests that blue whales are most closely related to sei whales with gray whales as a sister group. This study also found significant gene flow between minke whales and the ancestors of the blue and sei whale. Blue whales also displayed high genetic diversity. ==== Hybridization ==== Blue whales are known to interbreed with fin whales. The earliest description of a possible hybrid between a blue whale and a fin whale was a 20 m (66 ft) anomalous female whale with the features of both the blue and the fin whales taken in the North Pacific. A whale captured off northwestern Spain in 1984, was found to have been the product of a blue whale mother and a fin whale father. Two live blue-fin whale hybrids have since been documented in the Gulf of St. Lawrence (Canada), and in the Azores (Portugal). DNA tests done in Iceland on a blue whale killed in July 2018 by the Icelandic whaling company Hvalur hf., found that the whale was the offspring of a male fin whale and female blue whale; however, the results are pending independent testing and verification of the samples. Because the International Whaling Commission classified blue whales as a "Protection Stock", trading their meat is illegal, and the kill is an infraction that must be reported. Blue-fin hybrids have been detected from genetic analysis of whale meat samples taken from Japanese markets. Blue-fin whale hybrids are capable of being fertile. Molecular tests on a 21 m (70 ft) pregnant female whale caught off Iceland in 1986 found that it had a blue whale mother and a fin whale father, while its fetus was sired by a blue whale. In 2024, a genome analysis of North Atlantic blue whales found evidence that approximately 3.5% of the blue whales'
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
genome was derived from hybridization with fin whales. Gene flow was found to be unidirectional from fin whales to blue whales. Comparison with Antarctic blue whales showed that this hybridization began after the separation of the northern and southern populations. Despite their smaller size, fin whales have similar cruising and sprinting speeds to blue whales, which would allow fin males to complete courtship chases with blue females. There is a reference to a humpback–blue whale hybrid in the South Pacific, attributed to marine biologist Michael Poole. === Subspecies and stocks === At least four subspecies of blue whale are traditionally recognized, some of which are divided into population stocks or "management units". They have a worldwide distribution, but are mostly absent from the Arctic Ocean and the Mediterranean, Okhotsk, and Bering Sea. Northern subspecies (B. m. musculus) North Atlantic population – This population is mainly documented from New England along eastern Canada to Greenland, particularly in the Gulf of St. Lawrence, during summer though some individuals may remain there all year. They also aggregate near Iceland and have increased their presence in the Norwegian Sea. They are reported to migrate south to the West Indies, the Azores and northwest Africa. Eastern North Pacific population – Whales in this region mostly feed off California's coast from summer to fall and then Oregon, Washington State, the Alaska Gyre and Aleutian Islands later in the fall. During winter and spring, blue whales migrate south to the waters of Mexico, mostly the Gulf of California, and the Costa Rica Dome, where they both feed and breed. Central/Western Pacific population – This stock is documented around the Kamchatka Peninsula during the summer; some individuals may remain there year-round. They have been recorded wintering in Hawaiian waters, though some can be found in the Gulf of
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
Alaska during fall and early winter. Northern Indian Ocean subspecies (B. m. indica) – This subspecies can be found year-round in the northwestern Indian Ocean, though some individuals have recorded travelling to the Crozet Islands during between summer and fall. Pygmy blue whale (B. m. brevicauda) Madagascar population – This population migrates between the Seychelles and Amirante Islands in the north and the Crozet Islands and Prince Edward Islands in the south were they feed, passing through the Mozambique Channel. Australia/Indonesia population – Whales in this region appear to winter off Indonesia and migrate to their summer feeding grounds off the coast of Western Australia, with major concentrations at Perth Canyon and an area stretching from the Great Australian Bight and Bass Strait. Eastern Australia/New Zealand population – This stock may reside in the Tasman Sea and the Lau Basin in winter and feed mostly in the South Taranaki Bight and off the coast of eastern North Island. Blue whales have been detected around New Zealand throughout the year. Antarctic subspecies (B. m. intermedia) – This subspecies includes all populations found around the Antarctic. They have been recorded to travel as far north as eastern tropical Pacific, the central Indian Ocean, and the waters of southwestern Australia and northern New Zealand. Blue whales off the Chilean coast might be a separate subspecies based on their geographic separation, genetics, and unique song types. Chilean blue whales might overlap in the Eastern Tropical Pacific with Antarctica blue whales and Eastern North Pacific blue whales. Chilean blue whales are genetically differentiated from Antarctica blue whales such that interbreeding is unlikely. However, the genetic distinction is less between them and the Eastern North Pacific blue whale, hence there might be gene flow between the Southern and Northern Hemispheres. A 2019 study by Luis Pastene,
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
Jorge Acevedo and Trevor Branch provided new morphometric data from a survey of 60 Chilean blue whales, hoping to address the debate about the possible distinction of this population from others in the Southern Hemisphere. Data from this study, based on whales collected in the 1965/1966 whaling season, shows that both the maximum and mean body length of Chilean blue whales lies between these values in pygmy and Antarctic blue whales. Data also indicates a potential difference in snout-eye measurements between the three, and a significant difference in fluke-anus length between the Chilean population and pygmy blue whales. This further confirms Chilean blue whales as a separate population, and implies that they do not fall under the same subspecies as the pygmy blue whale (B. m. brevicauda). A 2024 genomic study of the global blue whale population found support for the subspecific status of Antarctic and Indo-western Pacific blue whales but not eastern Pacific blue whales. The study found "...divergence between the eastern North and eastern South Pacific, and among the eastern Indian Ocean, the western South Pacific and the northern Indian Ocean." and "no divergence within the Antarctic". == Description == The blue whale is a slender-bodied cetacean with a broad U-shaped head; thin, elongated flippers; a small 33 centimeters (13 in) sickle-shaped dorsal fin located close to the tail, and a large tail stock at the root of the wide and thin flukes. The upper jaw is lined with 70–395 black baleen plates. The throat region has 60–88 grooves which allows the skin to expand during feeding. It has two blowholes that can squirt 9.1–12.2 meters (30–40 ft) up in the air. The skin has a mottled grayish-blue coloration, appearing blue underwater. The mottling patterns near the dorsal fin vary between individuals. The underbelly has lighter pigmentation and
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
can appear yellowish due to diatoms in the water, which historically earned them the nickname "sulphur bottom". The male blue whale has the largest penis in the animal kingdom, at around 3 m (9.8 ft) long and 12 in (30 cm) wide. === Size === The blue whale is the largest animal known ever to have existed. Some studies have estimated that certain shastasaurid ichthyosaurs and the ancient whale Perucetus could have rivalled the blue whale in size, with Perucetus actually being heavier with a mean weight of 180 t (180 long tons; 200 short tons). However, these estimates were based on fragmentary remains, and the proposed size for Perucetus was disputed by studies in 2024. Other studies estimate that, on land, large sauropods like Bruhathkayosaurus (mean weight: 110–170 tons) and Maraapunisaurus (mean weight: 80–120 tons) might have rivalled the blue whale, with the former even exceeding the blue whale based on its most liberal estimates (240 tons). However, these estimates were based on even more fragmentary specimens that had disintegrated by the time estimates could be made. The International Whaling Commission (IWC) whaling database reports 88 individuals longer than 30 meters (98 ft), including one of 33 meters (108 ft). The Discovery Committee reported lengths up to 31 meters (102 ft). The longest scientifically measured individual blue whale was 30 meters (98 ft) from rostrum tip to tail notch. Female blue whales are larger than males. Hydrodynamic models suggest a blue whale could not exceed 33 metres (108 ft) because of metabolic and energy constraints. The average length of sexually mature female blue whales is 22.0 meters (72.1 ft) for Eastern North Pacific blue whales, 24 meters (79 ft) for central and western North Pacific blue whales, 21–24 meters (68–78 ft) for North Atlantic blue whales, 25.4–26.3 meters (83.4–86.3
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
ft) for Antarctic blue whales, 23.5 meters (77.1 ft) for Chilean blue whales, and 21.3 meters (69.9 ft) for pygmy blue whales. In the Northern Hemisphere, males weigh an average 100 metric tons (220,000 lb) and females 112 metric tons (247,000 lb). Eastern North Pacific blue whale males average 88.5 tonnes (195,000 lb) and females 100 tonnes (220,000 lb). Antarctic males average 112 tonnes (247,000 lb) and females 130 tonnes (290,000 lb). Pygmy blue whale males average 83.5 tonnes (184,000 lb) to 99 tonnes (218,000 lb). The weight of the heart of a stranded North Atlantic blue whale was 180 kg (400 lb), the largest known in any animal. The record-holder blue whale was recorded at 173 tonnes (190 short tons), with estimates of up to 199 tonnes (220 short tons). In 2024, Motani and Pyenson calculated the body mass of blue whales at different lengths, compiling records of their sizes from previous academic literatures and using regression analyses and volumetric analyses. A 25 metres (82 ft) long individual was estimated to weigh approximately 101–119 tonnes (111–131 short tons), while a 30 metres (98 ft) long individual was estimated to weigh approximately 184–205 tonnes (203–226 short tons). Considering that the largest blue whale was indeed 33 metres (108 ft) long, they estimated that a blue whale of such length would have weighed approximately 252–273 tonnes (278–301 short tons). During the harvest of a female blue whale, Messrs. Irvin and Johnson collected a fetus that is now 70% preserved and used for educational purposes. The fetus was collected in 1922, so some shrinkage may have occurred, making visualization of some features fairly difficult. However, due to this collection researchers now know that the external anatomy of a blue whale fetus is approximately 133 mm. Along with during the developmental phases, the
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
fetus is located where the embryonic and fetal phases converge. This fetus is the youngest gestational age of the specimen recorded. === Life span === Blue whales live around 80–90 years or more. Scientists look at a blue whale's earwax or ear plug to estimate its age. Each year, a light and dark layer of wax is laid corresponding with fasting during migration and feeding time. Each set is thus an indicator of age. The oldest blue whale found was determined, using this method, to be 110 years old. The maximum age of a pygmy blue whale determined this way is 73 years. In addition, female blue whales develop scars or corpora albicantia on their ovaries every time they ovulate. In a female pygmy blue whale, one corpus albicans is formed on average every 2.6 years. == Behavior and ecology == The blue whale is usually solitary, but can be found in pairs. When productivity is high enough, blue whales can be seen in gatherings of more than 50 individuals. Populations may go on long migrations, traveling to their summer feeding grounds towards the poles and then heading to their winter breeding grounds in more equatorial waters. The animals appear to use memory to locate the best feeding areas. There is evidence of alternative strategies, such as year-round residency, and partial (where only some individuals migrate) or age/sex-based migration. Some whales have been recorded feeding in breeding grounds. Blue whale typically swim at 2–8 kilometers per hour (1.2–5.0 mph) but may swim faster at 32–36 kilometers per hour (20–22 mph) during encounters with boats, predators or other individuals. Their massive size limits their ability to breach. The greatest dive depth reported from tagged blue whales was 315 meters (1,033 ft). Their theoretical aerobic dive limit was estimated at 31.2 minutes,
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
however, the longest dive measured was 15.2 minutes. The deepest confirmed dive from a pygmy blue whale was 506 meters (1,660 ft). A blue whale's heart rate can drop to 2 beats per minute (bpm) at deep depths, but upon surfacing, can rise to 37 bpm, which is close to its peak heart rate. === Diet and feeding === The blue whale's diet consists almost exclusively of krill. Blue whales capture krill through lunge feeding; they swim towards them at high speeds as they open their mouths up to 80°. They may engulf 220 metric tons (220 long tons; 240 short tons) of water at one time. They squeeze the water out through their baleen plates with pressure from the throat pouch and tongue, and swallow the remaining krill. Blue whales have been recorded making 180° rolls during lunge-feeding, possibly allowing them to search the prey field and find the densest patches. While pursuing krill patches, blue whales maximize their calorie intake by increasing the number of lunges while selecting the thickest patches. This provides them enough energy for everyday activities while storing additional energy necessary for migration and reproduction. Due to their size, blue whales have larger energetic demands than most animals resulting in their need for this specific feeding habit. Blue whales have to engulf densities greater than 100 krill/m3 to maintain the cost of lunge feeding. They can consume 34,776–1,912,680 kilojoules (8,312–457,141 kcal) from one mouthful of krill, which can provide up to 240 times more energy than used in a single lunge. It is estimated that an average-sized blue whale must consume 1,120 ± 359 kilograms (2,469 ± 791 lb) of krill a day. On average, a blue whale eats 4 t (3.9 long tons; 4.4 short tons) each day. In the southern ocean, blue whales
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
feed on Antarctic krill (Euphausia superba). In the South Australia, pygmy blue whales (B. m. brevicauda) feeds on Nyctiphanes australis. In California, they feed mostly on Thysanoessa spinifera, but also less commonly on North pacific krill (Euphausia pacifica). Research of the Eastern North Pacific population shows that when diving to feed on krill, the whales reach an average depth of 201 meters, with dives lasting 9.8 minutes on average. While most blue whales feed almost exclusively on krill, the Northern Indian Ocean subspecies (B. m. indica) instead feeds predominantly on sergestid shrimp. To do so, they dive deeper and for longer periods of time than blue whales in other regions of the world, with dives of 10.7 minutes on average, and a hypothesized dive depth of about 300 meters. Fecal analysis also found the presence of fish, krill, amphipods, cephalopods, and scyphozoan jellyfish in their diet. Blue whales appear to avoid directly competing with other baleen whales. Different whale species select different feeding spaces and times as well as different prey species. In the Southern Ocean, baleen whales appear to feed on Antarctic krill of different sizes, which may lessen competition between them. Blue whale feeding habits may differ due to situational disturbances, like environmental shifts or human interference. This can cause a change in diet due to stress response. Due to these changing situations, there was a study performed on blue whales measuring cortisol levels and comparing them with the levels of stressed individuals, it gave a closer look to the reasoning behind their diet and behavioral changes. === Reproduction and birth === The age of sexual maturity for blue whales is thought to be 5–15 years. In the Northern Hemisphere, the length at which they reach maturity is 21–23 meters (69–75 ft) for females and 20–21 meters (66–69
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
ft) for males. In the Southern Hemisphere, the length of maturity is 23–24 meters (75–79 ft) and 22 meters (72 ft) for females and males respectively. Male pygmy blue whales average 18.7 meters (61.4 ft) at sexual maturity. Female pygmy blue whales are 21.0–21.7 meters (68.9–71.2 ft) in length and roughly 10 years old at the age of sexual maturity. Since corpora are added every ~2.5 years after sexual maturity, physical maturity is assumed to occur at 35 years. Little is known about mating behavior, or breeding and birthing areas. Blue whales appear to be polygynous, with males competing for females. A male blue whale typically trails a female and will fight off potential rivals. The species mates from fall to winter. Pregnant females eat roughly four percent of their body weight daily, amounting to 60% of their overall body weight throughout summer foraging periods. Gestation may last 10–12 months with calves being 6–7 meters (20–23 ft) long and weighing 2–3 metric tons (2.0–3.0 long tons; 2.2–3.3 short tons) at birth. Estimates suggest that because calves require 2–4 kilograms (4.4–8.8 lb) milk per kg of mass gain, blue whales likely produce 220 kilograms (490 lb) of milk per day (ranging from 110 to 320 kilograms (240 to 710 lb) of milk per day). The first video of a calf thought to be nursing was filmed in New Zealand in 2016. Calves may be weaned when they reach 6–8 months old at a length of 16 meters (53 ft). They gain roughly 37,500 pounds (17,000 kg) during the weaning period. Interbirth periods last two to three years; they average 2.6 years in pygmy blue whales. Mother-calf pairings are infrequently observed, and this may be due to mothers birthing and weaning their young in-between their entry and return to their summer feeding
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
grounds. === Vocalizations === Blue whales produce some of the loudest and lowest frequency vocalizations in the animal kingdom, and their inner ears appear well adapted for detecting low-frequency sounds. The fundamental frequency for blue whale vocalizations ranges from 8 to 25 Hz. Blue whale songs vary between populations. Vocalizations produced by the Eastern North Pacific population have been well studied. This population produces pulsed calls ("A") and tonal calls ("B"), upswept tones that precede type B calls ("C") and separate downswept tones ("D"). A and B calls are often produced in repeated co-occurring sequences and sung only by males, suggesting a reproductive function. D calls may have multiple functions. They are produced by both sexes during social interactions while feeding. and by males when competing for mates. Blue whale calls recorded off Sri Lanka have a three-unit phrase. The first unit is a 19.8 to 43.5 Hz pulsive call, and is normally 17.9 ± 5.2 seconds long. The second unit is a 55.9 to 72.4 Hz FM upsweep that is 13.8 ± 1.1 seconds long. The final unit is 28.5 ± 1.6 seconds long with a tone of 108 to 104.7 Hz. A blue whale call recorded off Madagascar, a two-unit phrase, consists of 5–7 pulses with a center frequency of 35.1 ± 0.7 Hz lasting 4.4 ± 0.5 seconds proceeding a 35 ± 0 Hz tone that is 10.9 ± 1.1 seconds long. In the Southern Ocean, blue whales produce 18-second vocals which start with a 9-second-long, 27 Hz tone, and then a 1-second downsweep to 19 Hz, followed by a downsweep further to 18 Hz. Other vocalizations include 1–4 second long, frequency-modulated calls with a frequency of 80 and 38 Hz. There is evidence that some blue whale songs have temporally declined in tonal frequency. The vocalization
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
of blue whales in the Eastern North Pacific decreased in tonal frequency by 31% from the early 1960s to the early 21st century. The frequency of pygmy blue whales in the Antarctic has decreased by a few tenths of a hertz every year starting in 2002. It is possible that as blue whale populations recover from whaling, there is increasing sexual selection pressure (i.e., a lower frequency indicates a larger body size). === Predators === The only known natural predator to blue whales is the orca, although the rate of fatal attacks by orcas is unknown. Photograph-identification studies of blue whales have estimated that a high proportion of the individuals in the Gulf of California have rake-like scars, indicative of encounters with orcas. Off southeastern Australia, 3.7% of blue whales photographed had rake marks and 42.1% of photographed pygmy blue whales off Western Australia had rake marks. Documented predation by orcas has been rare. A blue whale mother and calf were first observed being chased at high speeds by orcas off southeastern Australia. The first documented attack occurred in 1977 off southwestern Baja California, Mexico, but the injured whale escaped after five hours. Four more blue whales were documented as being chased by a group of orcas between 1982 and 2003. The first documented predation event by orcas occurred in September 2003, when a group of orcas in the Eastern Tropical Pacific was encountered feeding on a recently killed blue whale calf. In March 2014, a commercial whale watch boat operator recorded an incident involving a group of orcas harassing a blue whale in Monterey Bay. The blue whale defended itself by slapping its tail. A similar incident was recorded by a drone in Monterey Bay in May 2017. The first direct observations of orca predation occurred off the south
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
coast of Western Australia, two in 2019 and one more in 2021. The first victim was estimated to be 18–22 meters (59–72 ft). === Infestations and health threats === In Antarctic waters, blue whales accumulate diatoms of the species Cocconeis ceticola and the genera Navicola, which are normally removed when the whales enter warmer waters. Barnacles such as Coronula diadema, Coronula reginae, and Cryptolepas rhachianecti, latch on to whale skin deep enough to leave behind a pit if removed. Whale lice species make their home in cracks of the skin and are relatively harmless. The copepod species Pennella balaenopterae digs in and attaches itself to the blubber to feed on. Intestinal parasites include the trematode genera Ogmogaster and Lecithodesmus; the tapeworm genera Priapocephalus, Phyllobotrium, Tetrabothrius, Diphyllobotrium, and Diplogonoporus; and the thorny-headed worm genus Bolbosoma. In the North Atlantic, blue whales also contain the protozoans Entamoeba, Giardia and Balantidium. == Conservation == The global blue whale population is estimated to be 5,000–15,000 mature individuals and 10,000–25,000 total as of 2018. By comparison, there were at least 140,000 mature whales in 1926. There are an estimated total of 1,000–3,000 whales in the North Atlantic, 3,000–5,000 in the North Pacific, and 5,000–8,000 in the Antarctic. There are possibly 1,000–3,000 whales in the eastern South Pacific while the pygmy blue whale may number 2,000–5,000 individuals. Blue whales have been protected in areas of the Southern Hemisphere since 1939. In 1955, they were given complete protection in the North Atlantic under the International Convention for the Regulation of Whaling; this protection was extended to the Antarctic in 1965 and the North Pacific in 1966. The protected status of North Atlantic blue whales was not recognized by Iceland until 1960. In the United States, the species is protected under the Endangered Species Act. Blue whales are
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
formally classified as endangered under both the U.S. Endangered Species Act and the IUCN Red List. They are also listed on Appendix I under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Convention on the Conservation of Migratory Species of Wild Animals. Although, for some populations, there is not enough information on current abundance trends (e.g., pygmy blue whales), others are critically endangered (e.g., Antarctic blue whales). === Threats === In 2017, DNA evidence was used to identify whale bones at Icelandic archaeological sites. Of the 124 bones analyzed more than 50% were from blue whales and some dated as far back as 900 CE. This, and other evidence, suggests that Icelanders were hunting whales as early as the 9th century, just as the settlement of Iceland began. Thus Icelanders would have been among the earliest known humans to hunt the blue whale. Blue whales were initially difficult to hunt because of their size and speed. This began to change in the mid-19th century with the development of harpoons that can be shot as projectiles. Blue whale whaling peaked between 1930 and 1931 with 30,000 animals taken. Harvesting of the species was particularly high in the Antarctic, with 350,000–360,000 whales taken in the first half of the 20th century. In addition, 11,000 North Atlantic whales (mostly around Iceland) and 9,500 North Pacific whales were killed during the same period. The International Whaling Commission banned all hunting of blue whales in 1966 and gave them worldwide protection. However, the Soviet Union continued to illegally hunt blue whales and other species up until the 1970s. Ship strikes are a significant mortality factor for blue whales, especially off the U.S. West Coast. A total of 17 blue whales were killed or suspected to have been
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
killed by ships between 1998 and 2019 off the U.S. West Coast. Five deaths in 2007 off California were considered an unusual mortality event, as defined under the Marine Mammal Protection Act. Lethal ship strikes are also a problem in Sri Lankan waters, where their habitat intersects with one of the world's most active shipping routes. Here, strikes caused the deaths of eleven blue whales in 2010 and 2012, and at least two in 2014. Ship-strike mortality claimed the lives of two blue whales off southern Chile in the 2010s. Possible measures for reducing future ship strikes include better predictive models of whale distribution, changes in shipping lanes, vessel speed reductions, and seasonal and dynamic management of shipping lanes. Few cases of blue whale entanglement in commercial fishing gear have been documented. The first report in the U.S. occurred off California in 2015, reportedly some type of deep-water trap/pot fishery. Three more entanglement cases were reported in 2016. In Sri Lanka, a blue whale was documented with a net wrapped through its mouth, along the sides of its body, and wound around its tail. Increasing man-made underwater noise impacts blue whales. They may be exposed to noise from commercial shipping and seismic surveys as a part of oil and gas exploration. Blue whales in the Southern California Bight decreased calling in the presence of mid-frequency active (MFA) sonar. Exposure to simulated MFA sonar was found to interrupt blue whale deep-dive feeding, but no changes in behavior were observed in individuals feeding at shallower depths. The responses also depended on the animal's behavioral state, its (horizontal) distance from the sound source and the availability of prey. The potential impacts of pollutants on blue whales is unknown. However, because blue whales feed low on the food chain, there is a lesser chance
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
for bioaccumulation of organic chemical contaminants. Analysis of the earwax of a male blue whale killed by a collision with a ship off the coast of California showed contaminants like pesticides, flame retardants, and mercury. Reconstructed persistent organic pollutant (POP) profiles suggested that a substantial maternal transfer occurred during gestation and/or lactation. Male blue whales in the Gulf of St. Lawrence, Canada, were found to have higher concentrations of PCBs, dichlorodiphenyltrichloroethane (DDT), metabolites, and several other organochlorine compounds relative to females, reflecting maternal transfer of these persistent contaminants from females into young. == See also == Largest organisms List of cetaceans List of largest mammals List of whale vocalizations == Note == == References == == Further reading == == External links == Blue whale vocalizations – Cornell Lab of Ornithology—Bioacoustics Research Program (archived 26 February 2015) Blue whale video clips and news from the BBC – BBC Wildlife Finder Voices in the Sea – Sounds of the Blue Whale NOAA Stock Assessments Life of a Hunter: Blue Whale Archived 31 December 2019 at the Wayback Machine – BBC America Living With Predators – BBC America
|
{
"page_id": 4925,
"source": null,
"title": "Blue whale"
}
|
The first isolation of deoxyribonucleic acid (DNA) was done in 1869 by Friedrich Miescher. DNA extraction is the process of isolating DNA from the cells of an organism isolated from a sample, typically a biological sample such as blood, saliva, or tissue. It involves breaking open the cells, removing proteins and other contaminants, and purifying the DNA so that it is free of other cellular components. The purified DNA can then be used for downstream applications such as PCR, sequencing, or cloning. Currently, it is a routine procedure in molecular biology or forensic analyses. This process can be done in several ways, depending on the type of the sample and the downstream application, the most common methods are: mechanical, chemical and enzymatic lysis, precipitation, purification, and concentration. The specific method used to extract the DNA, such as phenol-chloroform extraction, alcohol precipitation, or silica-based purification. For the chemical method, many different kits are used for extraction, and selecting the correct one will save time on kit optimization and extraction procedures. PCR sensitivity detection is considered to show the variation between the commercial kits. There are many different methods for extracting DNA, but some common steps include: Lysis: This step involves breaking open the cells to release the DNA. For example, in the case of bacterial cells, a solution of detergent and salt (such as SDS) can be used to disrupt the cell membrane and release the DNA. For plant and animal cells, mechanical or enzymatic methods are often used. Precipitation: Once the DNA is released, proteins and other contaminants must be removed. This is typically done by adding a precipitating agent, such as alcohol (such as ethanol or isopropanol), or a salt (such as ammonium acetate). The DNA will form a pellet at the bottom of the solution, while the contaminants
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
will remain in the liquid. Purification: After the DNA is precipitated, it is usually further purified by using column-based methods. For example, silica-based spin columns can be used to bind the DNA, while contaminants are washed away. Alternatively, a centrifugation step can be used to purify the DNA by spinning it down to the bottom of a tube. Concentration: Finally, the amount of DNA present is usually increased by removing any remaining liquid. This is typically done by using a vacuum centrifugation or a lyophilization (freeze-drying) step. Some variations on these steps may be used depending on the specific DNA extraction protocol. Additionally, some kits are commercially available that include reagents and protocols specifically tailored to a specific type of sample. == What does it deliver? == DNA extraction is frequently a preliminary step in many diagnostic procedures used to identify environmental viruses and bacteria and diagnose illnesses and hereditary diseases. These methods consist of, but are not limited to: Fluorescence In Situ Hybridization (FISH) technique was developed in the 1980s. The basic idea is to use a nucleic acid probe to hybridize nuclear DNA from either interphase cells or metaphase chromosomes attached to a microscopic slide. It is a molecular method used, among other things, to recognize and count particular bacterial groupings. To recognize, define, and quantify the geographical and temporal patterns in marine bacterioplankton communities, researchers employ a technique called terminal restriction fragment length polymorphism (T-RFLP). Sequencing: Whole or partial genomes and other chromosomal components, ended for comparison with previously published sequences. == Basic procedure == Cells that are to be studied need to be collected. Breaking the cell membranes open exposes the DNA along with the cytoplasm within (cell lysis). Lipids from the cell membrane and the nucleus are broken down with detergents and surfactants. Breaking down
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
proteins by adding a protease (optional). Breaking down RNA by adding an RNase (optional). The solution is treated with a concentrated salt solution (saline) to make debris such as broken proteins, lipids, and RNA clump together. Centrifugation of the solution, which separates the clumped cellular debris from the DNA. DNA purification from detergents, proteins, salts, and reagents is used during the cell lysis step. The most commonly used procedures are: Ethanol precipitation usually by ice-cold ethanol or isopropanol. Since DNA is insoluble in these alcohols, it will aggregate together, giving a pellet upon centrifugation. Precipitation of DNA is improved by increasing ionic strength, usually by adding sodium acetate. Phenol–chloroform extraction in which phenol denatures proteins in the sample. After centrifugation of the sample, denatured proteins stay in the organic phase while the aqueous phase containing nucleic acid is mixed with chloroform to remove phenol residues from the solution. Minicolumn purification relies on the fact that the nucleic acids may bind (adsorption) to the solid phase (silica or other) depending on the pH and the salt concentration of the buffer. Cellular and histone proteins bound to the DNA can be removed either by adding a protease or having precipitated the proteins with sodium or ammonium acetate or extracted them with a phenol-chloroform mixture before the DNA precipitation. After isolation, the DNA is dissolved in a slightly alkaline buffer, usually in a TE buffer, or in ultra-pure water. == Common chemicals == The most common chemicals used for DNA extraction include: Detergents, such as SDS or Tween-20, which are used to break open cells and release the DNA. Protease enzymes, such as Proteinase K, which are used to digest proteins that may be binding to the DNA. Phenol and chloroform, which are used to separate the DNA from other cellular components. Ethanol
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
or isopropanol, which are used to precipitate the DNA. Salt, such as NaCl, which is often used to help dissolve the DNA and maintain its stability. EDTA, which is used to chelate the metals ions that can damage the DNA. Tris-HCL, which is used to maintain the pH at the optimal condition for DNA extraction. == Method selection == Some of the most common DNA extraction methods include organic extraction, Chelex extraction, and solid phase extraction. These methods consistently yield isolated DNA, but they differ in both the quality and the quantity of DNA yielded. When selecting a DNA extraction method, there are multiple factors to consider, including cost, time, safety, and risk of contamination. Organic extraction involves the addition of incubation in multiple different chemical solutions; including a lysis step, a phenol-chloroform extraction, an ethanol precipitation, and washing steps. Organic extraction is often used in laboratories because it is cheap, and it yields large quantities of pure DNA. Though it is easy, there are many steps involved, and it takes longer than other methods. It also involves the unfavorable use of the toxic chemicals phenol and chloroform, and there is an increased risk of contamination due to transferring the DNA between multiple tubes. Several protocols based on organic extraction of DNA were effectively developed decades ago, though improved and more practical versions of these protocols have also been developed and published in the last years. The chelex extraction method involves adding the Chelex resin to the sample, boiling the solution, then vortexing and centrifuging it. The cellular materials bind to the Chelex beads, while the DNA is available in the supernatant. The Chelex method is much faster and simpler than organic extraction, and it only requires one tube, which decreases the risk of DNA contamination. Unfortunately, Chelex extraction does
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
not yield as much quantity and the DNA yielded is single-stranded, which means it can only be used for PCR-based analyses and not for RFLP. Solid phase extraction such as using a spin-column-based extraction method takes advantage of the fact that DNA binds to silica. The sample containing DNA is added to a column containing a silica gel or silica beads and chaotropic salts. The chaotropic salts disrupt the hydrogen bonding between strands and facilitate the binding of the DNA to silica by causing the nucleic acids to become hydrophobic. This exposes the phosphate residues so they are available for adsorption. The DNA binds to the silica, while the rest of the solution is washed out using ethanol to remove chaotropic salts and other unnecessary constituents. The DNA can then be rehydrated with aqueous low-salt solutions allowing for elution of the DNA from the beads. This method yields high-quality, largely double-stranded DNA which can be used for both PCR and RFLP analysis. This procedure can be automated and has a high throughput, although lower than the phenol-chloroform method. This is a one-step method i.e. the entire procedure is completed in one tube. This lowers the risk of contamination making it very useful for the forensic extraction of DNA. Multiple solid-phase extraction commercial kits are manufactured and marketed by different companies; the only problem is that they are more expensive than organic extraction or Chelex extraction. == Special types == Specific techniques must be chosen for the isolation of DNA from some samples. Typical samples with complicated DNA isolation are: archaeological samples containing partially degraded DNA, see ancient DNA samples containing inhibitors of subsequent analysis procedures, most notably inhibitors of PCR, such as humic acid from the soil, indigo and other fabric dyes or haemoglobin in blood samples from microorganisms with
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
thick cellular walls, for example, yeast samples containing mixed DNA from multiple sources Extrachromosomal DNA is generally easy to isolate, especially plasmids may be easily isolated by cell lysis followed by precipitation of proteins, which traps chromosomal DNA in insoluble fraction and after centrifugation, plasmid DNA can be purified from soluble fraction. A Hirt DNA Extraction is an isolation of all extrachromosomal DNA in a mammalian cell. The Hirt extraction process gets rid of the high molecular weight nuclear DNA, leaving only low molecular weight mitochondrial DNA and any viral episomes present in the cell. == Detection of DNA == A diphenylamine (DPA) indicator will confirm the presence of DNA. This procedure involves chemical hydrolysis of DNA: when heated (e.g. ≥95 °C) in acid, the reaction requires a deoxyribose sugar and therefore is specific for DNA. Under these conditions, the 2-deoxyribose is converted to w-hydroxylevulinyl aldehyde, which reacts with the compound, diphenylamine, to produce a blue-colored compound. DNA concentration can be determined by measuring the intensity of absorbance of the solution at the 600 nm with a spectrophotometer and comparing to a standard curve of known DNA concentrations. Measuring the intensity of absorbance of the DNA solution at wavelengths 260 nm and 280 nm is used as a measure of DNA purity. DNA can be quantified by cutting the DNA with a restriction enzyme, running it on an agarose gel, staining with ethidium bromide (EtBr) or a different stain and comparing the intensity of the DNA with a DNA marker of known concentration. Using the Southern blot technique, this quantified DNA can be isolated and examined further using PCR and RFLP analysis. These procedures allow differentiation of the repeated sequences within the genome. It is these techniques which forensic scientists use for comparison, identification, and analysis. == High-molecular-weight DNA extraction
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
method == In this method, plant nuclei are isolated by physically grinding tissues and reconstituting the intact nuclei in a unique Nuclear Isolation Buffer (NIB). The plastid DNAs are released from organelles and eliminated with an osmotic buffer by washing and centrifugation. The purified nuclei are then lysed and further cleaned by organic extraction, and the genomic DNA is precipitated with a high concentration of CTAB. The highly pure, high molecular weight gDNA is extracted from the nuclei, dissolved in a high pH buffer, allowing for stable long-term storage. == DNA storage == DNA storage is an important aspect of DNA extraction projects as it ensures the integrity and stability of the extracted DNA for downstream applications. One common method of DNA storage is ethanol precipitation, which involves adding ethanol and a salt, such as sodium chloride or potassium acetate, to the extracted DNA to precipitate it out of solution. The DNA is then pelleted by centrifugation and washed with 70% ethanol to remove any remaining contaminants. The DNA pellet is then air-dried and resuspended in a buffer, such as Tris-EDTA (TE) buffer, for storage. Another method is freezing the DNA in a buffer such as TE buffer, or in a cryoprotectant such as glycerol or DMSO, at -20 or -80 degrees Celsius. This method preserves the integrity of the DNA and slows down the activity of any enzymes that may degrade it. It's important to note that the choice of storage buffer and conditions will depend on the downstream application for which the DNA is intended. For example, if the DNA is to be used for PCR, it may be stored in TE buffer at 4 degrees Celsius, while if it is to be used for long-term storage or shipping, it may be stored in ethanol at -20 degrees
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
Celsius. The extracted DNA should be regularly checked for its quality and integrity, such as by running a gel electrophoresis or spectrophotometry. The storage conditions should be also noted and controlled, such as the temperature and humidity. It's also important to consider the long-term stability of the DNA and the potential for degradation over time. The extracted DNA should be stored for as short a time as possible, and the conditions for storage should be chosen to minimize the risk of degradation. In general, the extracted DNA should be stored under the best possible conditions to ensure its stability and integrity for downstream applications. == Quality control == There are several quality control techniques used to ensure the quality of extracted DNA, including: Spectrophotometry: This is a widely used method for measuring the concentration and purity of a DNA sample. Spectrophotometry measures the absorbance of a sample at different wavelengths, typically at 260 nm and 280 nm. The ratio of absorbance at 260 nm and 280 nm is used to determine the purity of the DNA sample. Gel electrophoresis: This technique is used to visualize and compare the size and integrity of DNA samples. The DNA is loaded onto an agarose gel and then subjected to an electric field, which causes the DNA to migrate through the gel. The migration of the DNA can be visualized using ethidium bromide, which intercalates into the DNA and fluoresces under UV light. Fluorometry: Fluorometry is a method to determine the concentration of nucleic acids by measuring the fluorescence of the sample when excited by a specific wavelength of light. Fluorometry uses dyes that specifically bind to nucleic acids and have a high fluorescence intensity. PCR: Polymerase Chain Reaction (PCR) is a technique that amplifies a specific region of DNA, it is also used
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
as a QC method by amplifying a small fragment of the DNA, if the amplification is successful, it means the extracted DNA is of good quality and it's not degraded. Qubit Fluorometer: The Qubit Fluorometer is an instrument that uses fluorescent dyes to measure the concentration of DNA and RNA in a sample. It is a quick and sensitive method that can be used to determine the concentration of DNA samples. Bioanalyzer: The bioanalyzer is an instrument that uses electrophoresis to separate and analyze DNA, RNA, and protein samples. It can provide detailed information about the size, integrity, and purity of a DNA sample. == See also == Boom method DNA fingerprinting DNA sequencing DNA structure Ethanol precipitation Plasmid preparation Polymerase chain reaction SCODA DNA purification == References == == Further reading == Sambrook, Michael R.; Green, Joseph (2012). Molecular Cloning (4th ed.). Cold Spring Harbor, N.Y.: Cold Spring Harbor Laboratory Pr. ISBN 1936113422. OCLC 774021237. == External links == How to extract DNA from anything living DNA Extraction Virtual Lab
|
{
"page_id": 1053500,
"source": null,
"title": "DNA extraction"
}
|
Avoidance reaction is a term used in the description of the movement of paramecium. This helps the cell avoid obstacles and causes other objects to bounce off of the cell's outer membrane. The paramecium does this by reversing the direction in which its cilia beat. This results in stopping, spinning or turning, after which point the paramecium resumes swimming forward. If multiple avoidance reactions follow one another, it is possible for a paramecium to swim backward, though not as smoothly as swimming forward. Avoidance reaction occurs when the cell hits an obstruction, providing an anterior, mechanical stimulus: The cell will then reverse. It will then stop and rotate. Now facing a new direction, the cell will move off in that direction. This process will continue until the cell is able to negotiate its way around the obstruction. Movement of Paramecium cells is caused by control of calcium ions inside the cell and membrane potentials. The simplest explanation for the avoidance reaction is that membrane potential controls the influx of calcium ions, which regulates the beat frequency and angles of cilia on the surface of the cell. == References ==
|
{
"page_id": 9638718,
"source": null,
"title": "Avoidance reaction"
}
|
Wafer bonding is a packaging technology on wafer-level for the fabrication of microelectromechanical systems (MEMS), nanoelectromechanical systems (NEMS), microelectronics and optoelectronics, ensuring a mechanically stable and hermetically sealed encapsulation. The wafers' diameter range from 100 mm to 200 mm (4 inch to 8 inch) for MEMS/NEMS and up to 300 mm (12 inch) for the production of microelectronic devices. Smaller wafers were used in the early days of the microelectronics industry, with wafers being just 1 inch in diameter in the 1950s. == Overview == In microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS), the package protects the sensitive internal structures from environmental influences such as temperature, moisture, high pressure and oxidizing species. The long-term stability and reliability of the functional elements depend on the encapsulation process, as does the overall device cost. The package has to fulfill the following requirements: protection against environmental influences heat dissipation integration of elements with different technologies compatibility with the surrounding periphery maintenance of energy and information flow == Techniques == The commonly used and developed bonding methods are as follows: Direct bonding Surface activated bonding Plasma activated bonding Anodic bonding Eutectic bonding Glass frit bonding Adhesive bonding Thermocompression bonding Reactive bonding Transient liquid phase diffusion bonding Atomic diffusion bonding == Requirements == The bonding of wafers requires specific environmental conditions which can generally be defined as follows: substrate surface flatness smoothness cleanliness bonding environment bond temperature ambient pressure applied force materials substrate materials intermediate layer materials The actual bond is an interaction of all those conditions and requirements. Hence, the applied technology needs to be chosen in respect to the present substrate and defined specification like max. bearable temperature, mechanical pressure or desired gaseous atmosphere. == Evaluation == The bonded wafers are characterized in order to evaluate a technology's yield, bonding strength and level
|
{
"page_id": 31331135,
"source": null,
"title": "Wafer bonding"
}
|
of hermeticity either for fabricated devices or for the purpose of process development. Therefore, several different approaches for the bond characterization have emerged. On the one hand non-destructive optical methods to find cracks or interfacial voids are used beside destructive techniques for the bond strength evaluation, like tensile or shear testing. On the other hand, the unique properties of carefully chosen gases or the pressure depending vibration behavior of micro resonators are exploited for hermeticity testing. == References == == Further reading == Peter Ramm, James Lu, Maaike Taklo (editors), Handbook of Wafer Bonding, Wiley-VCH, ISBN 3-527-32646-4.
|
{
"page_id": 31331135,
"source": null,
"title": "Wafer bonding"
}
|
DD-Peptidase may refer to: Muramoylpentapeptide carboxypeptidase, an enzyme Serine-type D-Ala-D-Ala carboxypeptidase, an enzyme
|
{
"page_id": 39260994,
"source": null,
"title": "DD-Peptidase"
}
|
A reedbed or reed bed is a natural habitat found in floodplains, waterlogged depressions and estuaries. Reedbeds are part of a succession from young reeds colonising open water or wet ground through a gradation of increasingly dry ground. As reedbeds age, they build up a considerable litter layer that eventually rises above the water level and that ultimately provides opportunities in the form of new areas for larger terrestrial plants such as shrubs and trees to colonise. Artificial reedbeds are used to remove pollutants from greywater, and are also called constructed wetlands. == Types == Reedbeds vary in the species that they can support, depending upon water levels within the wetland system, climate, seasonal variations, and the nutrient status and salinity of the water. Reed swamps have 20 cm or more of surface water during the summer and often have high invertebrate and bird species use. Reed fens have water levels at or below the surface during the summer and are often more botanically complex. Reeds and similar plants do not generally grow in very acidic water. In these situations, reedbeds are replaced by bogs and vegetation such as poor fen. Although common reeds are characteristic of reedbeds, not all vegetation dominated by this species is characteristic of reedbeds. It also commonly occurs in unmanaged, damp grassland and as an understorey in certain types of damp woodland. == Wildlife == Most European reedbeds mainly comprise common reed (Phragmites australis) but also include many other tall monocotyledons adapted to growing in wet conditions – other grasses such as reed sweet-grass (Glyceria maxima), Canary reed-grass (Phalaris arundinacea) and small-reed (Calamagrostis species), large sedges (species of Carex, Scirpus, Schoenoplectus, Cladium and related genera), yellow flag iris (Iris pseudacorus), reed-mace ("bulrush" – Typha species), water-plantains (Alisma species), and flowering rush (Butomus umbellatus). Many dicotyledons
|
{
"page_id": 1774404,
"source": null,
"title": "Reed bed"
}
|
also occur, such as water mint (Mentha aquatica), gipsywort (Lycopus europaeus), skull-cap (Scutellaria species), touch-me-not balsam (Impatiens noli-tangere), brooklime (Veronica beccabunga) and water forget-me-nots (Myosotis species). Many animals are adapted to living in and around reedbeds. These include mammals such as Eurasian otter, European beaver, water vole, Eurasian harvest mouse and water shrew, and birds such as great bittern, purple heron, European spoonbill, water rail (and other rails), purple gallinule, marsh harrier, various warblers (reed warbler, sedge warbler etc.), bearded reedling and reed bunting. == Uses == === Constructed wetlands === Constructed wetlands are artificial swamps (sometimes called reed fields) using reed or other marshland plants to form part of small-scale sewage treatment systems. Water trickling through the reedbed is cleaned by microorganisms living on the root system and in the litter. These organisms utilize the sewage for growth nutrients, resulting in a clean effluent. The process is very similar to aerobic conventional sewage treatment, as the same organisms are used, except that conventional treatment systems require artificial aeration. === Treatment ponds === Treatment ponds are small versions of constructed wetlands which uses reedbeds or other marshland plants to form an even smaller water treatment system. Similar to constructed wetlands, water trickling through the reedbed is cleaned by microorganisms living on the root system and in the litter. Treatment ponds are used for the water treatment of a single house or a small neighbourhood. == Gallery == == See also == Organisms used in water purification South Milton Ley == References ==
|
{
"page_id": 1774404,
"source": null,
"title": "Reed bed"
}
|
The palatine raphe (also median palatine raphe) is a raphe of the oral cavity. It is a narrow, slight midline ridge extending anteroposteriorly across the palate, from the incisive papilla anteriorly to the palatine uvula posteriorly. Beneath the raphe, the submucosa is absent.: 637 == Anatomy == The palatine raphe is a midline tendinous band of the palate.: 114 === Relations and attachments === The raphe is a surface feature overlying - and indicating - the intermaxillary suture, and median palatine suture.: 114-115 The greater palatine foramen may be palpated on either side about half way between the palatine raphe, and the palatal gingival margin of the 2nd or 3rd upper molar tooth.: 59, 220 The palatine raphe serves as an attachment for multiple muscles: the palatoglossus muscle arises from the posterior portion of the raphe; the levator veli palatini muscle and (the tendon of) the tensor veli palatini muscle insert into the raphe.: 114-115 == References == == External links == "Anatomy diagram: 05287.011-1". Roche Lexicon - illustrated navigator. Elsevier. Archived from the original on 2013-04-22. Diagram at bris.ac.uk Diagram at ana.bris.ac.uk Diagram at waybuilder.net
|
{
"page_id": 9311047,
"source": null,
"title": "Palatine raphe"
}
|
Calcium plays a crucial role in regulating the events of cellular division. Calcium acts both to modulate intracellular signaling as a secondary messenger and to facilitate structural changes as cells progress through division. Exquisite control of intracellular calcium dynamics are required, as calcium appears to play a role at multiple cell cycle checkpoints. The major downstream calcium effectors are the calcium-binding calmodulin protein and downstream calmodulin-dependent protein kinases I / II. Evidence points to this signaling cascade as a major mediator of calcium signaling in cell division. == Meiosis == Historically, one of the most well characterized roles of intracellular calcium is activation of the ovum after sperm fertilization. In deuterosome eggs (mammals, fish, amphibians, ascidians, sea urchins, etc.), successful sperm entry leads to a distinct rise in intracellular calcium ions (Ca2+), with mammals and ascidians displaying a series of intracellular calcium spikes required for completion of meiosis.... Unfertilized vertebrate eggs arrest development after meiosis I. This developmental pause is attributed to the vaguely defined cytostatic factor (CSF). Current researches suggest “CSF” is actually multiple pathways working together to halt division at metaphase of meiosis II. Upon sperm entry into the egg, Ca2+ is released from intracellular stores, leading to inhibition of the CSF-arrest mechanism. Calmodulin dependent kinase II was shown to be the protein responsible for converting the Ca2+ influx signal into inhibition of CSF and activation of cyclin degradation machinery to degrade cyclin B, resulting in progression through meiosis II. In mammals, this rise in Ca2+ was shown to be driven by IP3 stimulation induced by PLCζ provided by the sperm. In general, PLC enzymes stimulate calcium release by internal stores through the breakdown of PIP2 into IP3 and DAG. == Mitosis == === Signaling === Beyond the events of meiosis, changes in Ca2+ levels are observed in
|
{
"page_id": 55841611,
"source": null,
"title": "Calcium signaling in cell division"
}
|
a variety of organisms at different stages of division, such as nuclear membrane breakdown and the metaphase-anaphase transition. Further, recent work has shown mechanically induced rapid entry into mitosis of cells paused in G2. Further, progression through division requires the presence of calcium (G1/S, G2/M, and metaphase/anaphase), suggesting checkpoints require a calcium-dependent signaling mechanism ==== G1/S ==== Entry into S-phase is calcium dependent. Depleting internal calcium stores inhibits initiation of DNA synthesis. One possible mechanism is that cyclin A synthesis is inhibited, preventing cdk2 activity which is required for initiation of DNA synthesis. ===== G2/M ===== Cell cycle progression is regulated by multiple pathways. It was shown using human cancer cell lines, that the G2/M checkpoint is regulated by CaMKII and MAPK crosstalk. Here, CaMKII activates MEK/ERK, which degrades the cell cycle arresting p27 protein === Disease === In general, transformed cells proliferate in a calcium-independent manner, whereas non-transformed cells show high sensitivity to extra-cellular calcium concentration, suggesting oncogenic growth may include disruption of calcium signaling. === Chromatin Structure === Condensation of chromatin is a vital step in cell division, allowing cells to equally distribute chromosomes to the daughter cells. Recent work has suggested that Ca2+ is required for enabling chromatin condensation in prometaphase. Calcium was found to concentrate on condensed DNA to much higher levels compared to normal cytosolic calcium concentration. The role of calcium in condensation was independent of CAMK function, suggesting a purely structural role of Ca2+ in chromatin compaction. Further, this result was demonstrated in vitro with extracted chromatin, emphasizing that the mere presence of Ca2+ can influence the structure of chromatin == References ==
|
{
"page_id": 55841611,
"source": null,
"title": "Calcium signaling in cell division"
}
|
A Radio Recombination Line (RRL) in astrophysics is a spectral emission line produced by the transition of electrons between two energy levels in an atom, and with a rest frequency in the radio band of the electromagnetic spectrum. This effect is believed to be produced in ionized gas, and driven by the recombination of ions with electrons, when the energy of the electron falls enough to be captured by the ion. Following this capture, the electron cascades down through the energy levels to a stable state, emitting a photon at each transition. In low density regions of the Interstellar Medium (ISM), these atoms can remain stable up to very high quantum number (n~1000), and have a diameter up to 1 micron across, similar to the size of human hair. The Bohr model predicting the strength of emission lines at different quantum numbers allows for the existence of RRLs, but they were not studied until several decades later in 1945 by Dutch astronomer, Hendrik van de Hulst. In his work, van de Hulst proposed the existence of observable radio line emission from highly excited atoms in the ISM, as well as predicted the observable 21cm emission in neutral hydrogen regions. For Hydrogen, this effect occurs in HII regions and can be thought of as a rarer example of the Hydrogen spectral series, only occurring for electron transitions beginning above n > 27 {\displaystyle n>27} . The first search for astronomical RRLs began in 1958 by T.M. Egorova and N.F. Ryzhkov, focusing on the H271α line in the galactic plane, resulting in no clear detection of the line. Six years after the first searches began, a group at Lebedev Physical Institute in Moscow, Russia detected the first RRLs using a 22-m radio telescope on 27 April 1964. The group detected the H90α
|
{
"page_id": 79827787,
"source": null,
"title": "Radio Recombination Lines"
}
|
transition, at a rest frequency of 8872.5 MHz and produced in the Omega Nebula. A separate Russian group detected the H104α line one month later in May 1964, again in the Omega nebula. RRLs were first observed at cosmological distances ( z = 1.124) in 2019, and are suggested to have originated from a warm Hydrogen or cold neutral Carbon region within a dwarf-like galaxy that is being energized by a background quasar. == References ==
|
{
"page_id": 79827787,
"source": null,
"title": "Radio Recombination Lines"
}
|
An electrojet is an electric current which travels around the E region of the Earth's ionosphere. There are three electrojets: one above the magnetic equator (the equatorial electrojet), and one each near the Northern and Southern Polar Circles (the Auroral Electrojets). Electrojets are Hall currents carried primarily by electrons at altitudes from 100 to 150 km. In this region the electron gyro frequency (Larmor frequency) is much greater than the electron-neutral collision frequency. In contrast, the principal E region ions (O2+ and NO+) have gyrofrequencies much lower than the ion-neutral collision frequency. Kristian Birkeland was the first to suggest that polar electric currents (or auroral electrojets) are connected to a system of filaments (now called "Birkeland currents") that flow along geomagnetic field lines into and away from the polar region. == Equatorial Electrojet == The worldwide solar-driven wind results in the so-called Sq (solar quiet) current system in the E region of the Earth's ionosphere (100–130 km altitude). Resulting from this current is an electrostatic field directed E-W (dawn-dusk) in the equatorial day side of the ionosphere. At the magnetic dip equator, where the geomagnetic field is horizontal, this electric field results in an enhanced eastward current within ± 3 degrees of the magnetic equator, known as the equatorial electrojet. == Auroral Electrojet == The term 'auroral electrojet' is the name given to the large horizontal currents that flow in the D and E regions of the auroral ionosphere. Although horizontal ionospheric currents can be expected to flow at any latitude where horizontal ionospheric electric fields are present, the auroral electrojet currents are remarkable for their strength and persistence. There are two main factors in the production of the electrojet. First of all, the conductivity of the auroral ionosphere is generally larger than that at lower latitudes. Secondly, the horizontal
|
{
"page_id": 5575501,
"source": null,
"title": "Electrojet"
}
|
electric field in the auroral ionosphere is also larger than that at lower latitudes. Since the strength of the current is directly proportional to the vector product of the conductivity and the horizontal electric field, the auroral electrojet currents are generally larger than those at lower latitudes. During magnetically quiet periods, the electrojet is generally confined to the auroral oval. However, during disturbed periods, the electrojet increases in strength and expands to both higher and lower latitudes. This expansion results from two factors, enhanced particle precipitation and enhanced ionospheric electric fields. The Auroral Electrojet Index measures magnetic activity as observed by a chain of high-latitude observatories. == See also == Magnetohydrodynamics Kennelly–Heaviside layer Ionosphere "The Earth's Ionosphere: Plasma Physics and Electrodynamics," by Michael Kelley, Academic Press, ISBN 9780120884254 == References == == External links == https://web.archive.org/web/20100705021933/http://www-star.stanford.edu/~vlf/ejet/electrojet.html
|
{
"page_id": 5575501,
"source": null,
"title": "Electrojet"
}
|
Teleology in biology is the use of the language of goal-directedness in accounts of evolutionary adaptation, which some biologists and philosophers of science find problematic. The term teleonomy has also been proposed. Before Darwin, organisms were seen as existing because God had designed and created them; their features such as eyes were taken by natural theology to have been made to enable them to carry out their functions, such as seeing. Evolutionary biologists often use similar teleological formulations that invoke purpose, but these imply natural selection rather than actual goals, whether conscious or not. Some biologists and religious thinkers held that evolution itself was somehow goal-directed (orthogenesis), and in vitalist versions, driven by a purposeful life force. With evolution working by natural selection acting on inherited variation, the use of teleology in biology has attracted criticism, and attempts have been made to teach students to avoid teleological language. Nevertheless, biologists still often write about evolution as if organisms had goals, and some philosophers of biology such as Francisco Ayala and biologists such as J. B. S. Haldane consider that teleological language is unavoidable in evolutionary biology. == Context == === Teleology === Teleology, from Greek τέλος, telos "end, purpose" and -λογία, logia, "a branch of learning", was coined by the philosopher Christian von Wolff in 1728. The concept derives from the ancient Greek philosophy of Aristotle, where the final cause (the purpose) of a thing is its function. However, Aristotle's biology does not envisage evolution by natural selection. Phrases used by biologists like "a function of ... is to ..." or "is designed for" are teleological at least in language. The presence of real or apparent teleology in explanations of natural selection is a controversial aspect of the philosophy of biology, not least for its echoes of natural theology. ===
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
Natural theology === Before Darwin, natural theology both assumed the existence of God and used the appearance of function in nature to argue for the existence of God. The English parson-naturalist John Ray stated that his intention was "to illustrate the glory of God in the knowledge of the works of nature or creation". Natural theology presented forms of the teleological argument or argument from design, namely that organs functioned well for their apparent purpose, so they were well-designed, so they must have been designed by a benevolent creator. For example, the eye had the function of seeing, and contained features like the iris and lens that assisted with seeing; therefore, ran the argument, it had been designed for that purpose. === Goal-directed evolution === Religious thinkers and biologists have supposed that evolution was driven by some kind of life force, a philosophy known as vitalism, and have often supposed that it had some kind of goal or direction (towards which the life force was striving, if they also believed in that), known as orthogenesis or evolutionary progress. Such goal-directedness implies a long-term teleological force; some supporters of orthogenesis considered it to be a spiritual force, while others held that it was purely biological. For example, the embryologist Karl Ernst von Baer believed in a teleological force in nature, whereas the spiritualist philosopher Henri Bergson linked orthogenesis with vitalism, arguing for a creative force in evolution known as élan vital in his book Creative Evolution (1907). The biophysicist Pierre Lecomte du Noüy and the botanist Edmund Ware Sinnott developed vitalist evolutionary philosophies known as telefinalism and telism respectively. Their views were heavily criticized as non-scientific; the palaeontologist George Gaylord Simpson argued that Du Noüy and Sinnott were promoting religious versions of evolution. The Jesuit paleontologist Pierre Teilhard de Chardin argued
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
that evolution was aiming for a supposed spiritual "Omega Point" in what he called "directed additivity". With the emergence of the modern evolutionary synthesis, in which the genetic mechanisms of evolution were discovered, the hypothesis of orthogenesis was largely abandoned by biologists, especially with Ronald Fisher's argument in his 1930 book The Genetical Theory of Natural Selection. === Natural selection === Natural selection, introduced in 1859 as the central mechanism of evolution by Charles Darwin, is the differential survival and reproduction of individuals due to differences in phenotype. The mechanism directly implies evolution, a change in heritable traits of a population over time. === Adaptation === A trait which persists in a population is often assumed by biologists to have been selected for in the course of evolution, raising the question of how the trait achieves this. Biologists call any such mechanism the function of the trait, using phrases like "A function of stotting by antelopes is to communicate to predators that they have been detected", or "The primate hand is designed (by natural selection) for grasping." An adaptation is an observable structure or other feature of an organism (for example, an enzyme) generated by natural selection to serve its current function. A biologist might propose the hypothesis that feathers are adaptations for bird flight. That would require three things: that the trait of having feathers is heritable; that the trait does serve the function of flight; and that the trait increases the fitness of the organisms that have it. Feathers clearly meet these three conditions in living birds. However, there is also a historical question, namely, did the trait arise at the same time as bird flight? Unfortunately for the hypothesis, this seems not to be so: theropod dinosaurs had feathers, but many of them did not fly. Feathers
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
can be described as an exaptation, having been co-opted for flight but having evolved earlier for another purpose such as insulation. Biologists may describe both the co-option and the earlier adaptation in teleological language. == Status in evolutionary biology == === A problematic issue === Apparent teleology is a recurring issue in evolutionary biology, much to the consternation of some writers, and as an explanatory style it remains controversial. There are various reasons why biologists may find teleology problematic. Firstly, the concept of adaptation is itself controversial, as it can be taken to imply, as the evolutionary biologists Stephen J. Gould and Richard Lewontin argued, that biologists agree with Voltaire's Doctor Pangloss in his 1759 satire Candide that this is "the best of all possible worlds", in other words that every trait is perfectly suited to its functions. However, all that evolutionary biology requires is the weaker claim that one trait is at least slightly better in a certain context than another, and hence is selected for. Secondly, teleology is linked to the pre-Darwinian idea of natural theology, that the natural world gives evidence of the conscious design and beneficent intentions of a creator, as in the writings of John Ray. William Derham continued Ray's tradition with books such as his 1713 Physico-Theology and his 1714 Astro-Theology. They in turn influenced William Paley who wrote a detailed teleological argument for God in 1802, Natural Theology, or Evidences of the Existence and Attributes of the Deity collected from the Appearances of Nature, starting with the watchmaker analogy. Such creationism, along with a vitalist life-force and directed orthogenetic evolution, has been rejected by most biologists. Thirdly, attributing purposes to adaptations risks confusion with popular forms of Lamarckism where animals in particular have been supposed to influence their own evolution through their intentions,
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
though Lamarck himself spoke rather of habits of use, and the belief that his thinking was teleological has been challenged. Fourthly, the teleological explanation of adaptation is uncomfortable because it seems to require backward causation, in which existing traits are explained by future outcomes; because it seems to attribute the action of a conscious mind when none is assumed to be present in an organism; and because, as a result, adaptation looks impossible to test empirically. A fifth reason concerns students rather than researchers: Gonzalez Galli argues that since people naturally imagine that evolution has a purpose or direction, then the use of teleological language by scientists may act as an obstacle to students when learning about natural selection. Such language, he argues, should be removed to make teaching more effective. === Removable teleological shorthand === Statements which imply that nature has goals, for example where a species is said to do something "in order to" achieve survival, appear teleological, and therefore invalid to evolutionary biologists. It is however usually possible to rewrite such sentences to avoid the apparent teleology. Some biology courses have incorporated exercises requiring students to rephrase such sentences so that they do not read teleologically. Nevertheless, biologists still frequently write in a way which can be read as implying teleology, even though that is not their intention. John Reiss argues that evolutionary biology can be purged of apparent teleology by rejecting the pre-Darwinian watchmaker analogy for natural selection; other arguments against this analogy have also been promoted by writers such as the evolutionary biologist Richard Dawkins. Some philosophers of biology such as James G. Lennox have argued that Darwin was a teleologist, while others like Michael Ghiselin described this claim as a myth promoted by misinterpretations of his discussions, and emphasized the distinction between using teleological
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
metaphors and actually being teleological. Michael Heads, on the other hand, describes a change in Darwin's thinking about evolution that can be traced from the first volume of On the Origin of Species to later volumes. For Heads, Darwin was originally a far more teleological thinker, but over time, "learned to avoid teleology." Heads cites a letter Darwin wrote in 1872, in which he downplayed the role of natural selection as a causal force on its own in explaining biological adaptation, and instead gave more weight to "laws of growth," that operate [without the aid of natural selection]. Andrew Askland, from the Sandra Day O'Connor College of Law claims that unlike transhumanism, an ideology that aims to improve the human condition, which he asserts is "wholly teleological", Darwinian evolution is not teleological. Various commentators view the teleological phrases used in modern evolutionary biology as a type of shorthand for describing any function which offers an evolutionary advantage through natural selection. For example, the zoologist S. H. P. Madrell wrote that "the proper but cumbersome way of describing change by evolutionary adaptation [may be] substituted by shorter overtly teleological statements" for the sake of saving space, but that this "should not be taken to imply that evolution proceeds by anything other than from mutations arising by chance, with those that impart an advantage being retained by natural selection." === Irreducible teleology === Other philosophers of biology argue instead that biological teleology is irreducible, and cannot be removed by any simple process of rewording. Francisco Ayala specified three separate situations in which teleological explanations are appropriate. First, if the agent consciously anticipates the goal of their own action; for example the behavior of picking up a pen can be explained by reference to the agent's desire to write. Ayala extends this type
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
of teleological explanation to non-human animals by noting that "A deer running away from a mountain lion ... has at least the appearance of purposeful behavior." Second, teleological explanations are useful for systems that have a mechanism for self-regulation despite fluctuations in environment; for example, the self-regulation of body temperature in animals. Finally, they are appropriate "in reference to structures anatomically and physiologically designed to perform a certain function." Ayala, relying on work done by the philosopher Ernest Nagel, also rejects the idea that teleological arguments are inadmissible because they cannot be causal. For Nagel, teleological arguments must be consistent because they can always be reformulated as non-teleological arguments. The difference between the two is, for Ayala, merely one of emphasis. Nagel writes that while teleological arguments focus on "the consequences for a given system of a constituent part or process," the equivalent non-teleological arguments focus on ""some of the conditions ... under which the system persists in its characteristic organization and activities." However, Francisco Ayala argued that teleological statements are more explanatory and cannot be disposed of. Karen Neander similarly argued that the modern concept of biological 'function' depends on natural selection. So, for example, it is not possible to say that anything that simply winks into existence, without going through a process of selection, actually has functions. We decide whether an appendage has a function by analysing the process of selection that led to it. Therefore, Neander argues, any talk of functions must be posterior to natural selection, function must be defined by reference to the history of a species, and teleology cannot be avoided. The evolutionary biologist Ernst Mayr likewise stated that "adaptedness ... is an a posteriori result rather than an a priori goal-seeking." Angela Breitenbach, from a Kantian perspective, argues in Kant Yearbook that teleology
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
in biology is important as "a heuristic in the search for causal explanations of nature and ... an inevitable analogical perspective on living beings." In her view of Kant, teleology implies something that cannot be explained by science, but only understood through analogy. Colin Pittendrigh coined the similar term 'teleonomy' for apparently goal-directed biological phenomena. For Pittendrigh, the notion of 'adaptation' in biology, however it is defined, necessarily "connote that aura of design, purpose, or end-directedness, which has, since the time of Aristotle, seemed to characterize the living thing." This association with Aristotle, however, is problematic, because it meant that the study of adaptation would inevitably be bound up with teleological explanations. Pittendrigh sought to preserve the aspect of design and purpose in biological systems, while denying that this design can be understood as a causal principle. The confusion, he says, would be removed if we described these systems "by some other term, like 'teleonomic,' in order to emphasize that the recognition and description of end-directedness does not carry a commitment to Aristotelian teleology as an efficient causal principle." Ernst Mayr criticised Pittendrigh's confusion of Aristotle's four causes, arguing that evolution only involved the material and formal but not the efficient cause. Mayr proposed to use the term only for "systems operating on the basis of a program of coded information." William C. Wimsatt affirmed that the teleologicality of the language of biology and other fields derives from the logical structure of their background theories, and not merely from the use of teleological locutions such as "function" and "in order to". He stated that "To replace talk about function by talk about selection ... is not to eliminate teleology but to rephrase it". However, Wimsatt argues that this thought does not mean an appeal to backwards causation, vitalism, entelechy, or
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
anti-reductionist sentiments. The biologist J. B. S. Haldane observed that "Teleology is like a mistress to a biologist: he cannot live without her but he's unwilling to be seen with her in public." == See also == Fitness landscape Teleomechanism == Notes == == References ==
|
{
"page_id": 51188560,
"source": null,
"title": "Teleology in biology"
}
|
Helopeltis antonii, also known as the tea mosquito bug, are heteropterans found within the Miridae family. They have a relatively large geographical distribution and are a known pest of many agricultural “cash” crops such as cocoa, cashew, and tea. Subsequently, their impact negatively influences economic growth within the regions in which they inhabit. Thus, their impact on humans has caused them to be of great interest biologically, resulting in significant environmental implications. == Distribution == Helopeltis antonii are found in a region known as the old-world tropics which encompasses places such as India, Northern Australia, Guinea, Vietnam, Tanzania, Nigeria, and Indonesia. More specifically, they are more concentrated in the agricultural regions of the old-world tropics. In India their distribution is primarily found within the “cashew belt” which is located along the western coast and central regions of the country due to its high affinity for these plants. However, different nations grow certain crops in various locations within their borders. Crops that H. antonii prefer will ultimately determine their specific distribution within a country. === Identification of distribution === H. antonii are often mistaken and misidentified with other Helopeltis species. Thus, identifying the exact geographical range of H. antonii has become a difficult process. However, recent advances in species identification though DNA barcoding has made it much easier. DNA barcoding is a rapid and relatively inexpensive identification technique that locates unique genetic markers in their DNA allowing for the accurate identification of not only H. antonii, but other species as well. == Mating == Reproduction for H. antonii occurs in 4 stages—arousal, mounting, copulation, and termination of copulation—and occurs year-round. Mounting, arousal, and termination of copulation occurs within a short time frame; copulation is much longer and more variable in length. Mating typically occur in shaded, covered areas === Arousal ===
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
Arousal consists of both chemical and tactile stimuli. Pheromones play an important role in the chemical attraction of females for mating. Although these chemical cues are important, physical cues comprise the bulk of mate attraction and arousal. Males are the sole initiators for reproductive encounters. This first done through sexual identification of a female partner. Sexual identification is only possible when in close proximity of each other. Once a female is located, the male makes contact with the female by gently probing her body with his antennae. Receptive females remain passive, permitting the male to proceed. In contrast, non-receptive females move to escape any further male interaction. === Mounting === Following the initial arousal, the process of mounting ensues. Males mount females on the posterior region of her body allowing the erect male rostrum to stroke the dorsal side of the female, just below the thoracic shield. This stroking behaviour quiets the female and allows for easier insertion of the male aedeagus into the female genital aperture. If insertion is not achieved the male begins a left to right stroking motion to aid in its insertion. Females can also kick or shake males off to prevent further progression of mating. When this occurs, males are quick to remount and re-attempt insertion of their aedeagus into the female genital aperture. Successful insertion leads to copulation. === Copulation === Once insertion has been established the male twists around in an end-to-end fashion to allow for copulation. Once in this end-to-end position, both the male and female remain still until copulation has completed. This can last anywhere from 10 minutes to 2 hours. === Termination of copulation === Following copulation, they abruptly disjoin, however, detachment can be often difficult due to the males' twisted position. Once separated both the male and female begin
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
to feed and clean their own genitals and antenna—this feeding and cleaning behaviour typically occurs within a few steps from the site of copulation. Females do not respond to any other mating advances immediately following copulation. However, females typically reproduce more than once during their lifetime. Interspecific mating has been known to occur between Helopeltis species, specifically between H. antonii and H. theivora. However, their mating results in the production of unviable eggs. The production of eggs following interspecific mating between H. antonii and H. bradyi has not been observed. This ability and inability to engage in interspecific mating is due to the difference in genital structure between females. Females of both H. antonii and H. theivora have sclerotized rings that are not fused, whereas, the females of H. bradyi have fused sclerotized rings in its genitalia. This difference acts like a “lock and key” model for genitalia. == Oviposition == Males and females are able to reproduce and lay viable eggs after their first day of sexual maturity. Unmated females are capable of laying eggs; however, they are sterile. The sex ratio of males to females does not influence the number of eggs a female can lay but environments with a high ratio reduces female longevity due to mating exhaustion. Females that reproduce more than once lay a larger number of eggs during oviposition. Females probe plant tissues with the tip of their rostrum to find a suitable site for the deposition of their eggs. The exact reason behind site choice is unknown, but once found the female bends her abdomen to establish contact between her ovipositor and the plant tissue. The ovipositor is then inserted into the plant tissue and the eggs are deposited, below the epidermis and parenchymatous tissue of the plant, via abdominal contractions. The eggs
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
are ovo-elongate and silvery-white in colour and are approximately 1.0x0.3mm in size. Abundance of eggs laid is also weather dependent. Conditions that yield higher temperatures and increased sun exposure result in a higher abundance; whereas cooler temperatures, less available sunlight, and increased rain exposure reduces abundance. == Development == H. antonii experiences partial metamorphosis, otherwise known as hemimetabolous development, which is characterized by it transition from an egg to nymph and eventually into a matured adult. This developmental pattern takes about 25 days from the time the eggs are laid to adulthood. The eggs take eggs 12–13 days to hatch followed by 12–13 days of progressive nymph instars. H. antonii experience 5 instars in total before reaching adulthood. During the first instar, the body appears light orange in colour and progresses to a deep orange in the second instar. During the third instar, the body beings to develop wing buds and a scutellar horn. Wing pads become visibly prominent as the fourth instar emerges. Finally, in the fifth instar, the wing pads cover half of the abdomen—with the wings being transparent—and the body is light brown in colour but darkens via sclerotization. Additionally, in the fifth instar, the dorsum of the thorax appears red in colour, the tergum of the abdomen a dull white, the dorsal abdominal segment a deep orange colour, and overlapped hemi-elytra covers over the abdomen with its distal end containing a triangular blackish-brown colouration. The less-matured first, second and third instars tend to group close to each other and remain in proximity of their hatch site for feeding. In contrast, the more matured fourth and fifth instars tend to be more dispersed and feed in areas farther from their hatch site as a result. Matured females have a characteristic white patch present on their fifth abdominal
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
segment. === Environmental influence === Although colouration is an important identifying feature of H. antonii it is subject to variation due to variations in temperature and sunlight exposure. Red colour morphs tend to peak in abundance during October and reach their minimum abundance during February (for males) and June (for females). Black colour morphs peak during June for both sexes. A brownish-black colour morph is also seen within the population, but its abundance is low, and its frequency remains constant throughout the year. == Diet and feeding == H. antonii are herbivorous insects that have been known to feed on more than 100 different plant species. The sites of feeding, on these plant hosts, are not localized. Rather, both adult and nymphs feed on various sites ranging from tender shoots, buds, stems, and even their fruiting bodies to obtain sap. H. antonii possess modified mouthparts which work to form a long straw-like structure known as a “stylet”. This modified mouth part enables them to suck up sap from deep within the plant tissues that would not otherwise be as easily accessible. === Seasonal Consumption === H. antonii feed on both native plants as well as agriculturally grown crops. However, their availability changes with the seasons. This change in availability is due to the different growth cycles host plants experience throughout the year. As host plants enter their fruiting or flushing stages, they begin to have a higher rates of sap production and as a result become targeted by H. antonii. In native, non-cultivated, habitats there appears to be a preference for certain types of host plants even when many others are present. During January to February Annona is preferred, from March to April neem is preferred, from May to August papaya is preferred, and from September to December Singapore cherry
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
is preferred. In addition to the consumption of native plant species, agricultural “cash crops” such black pepper, cashew, cocoa, and tea as are often at high risk for consumption and damage due to their large-scale cultivation and ease of accessibility. However, their feeding schedule on these is agricultural crops are more restricted based due to growing and harvest seasons. === Plant preference === Like the seasonal preference of plants, preference is also seen in consumption habits of fruits with respect to different plants. For example, in custard apples the immature fruits are preferred over the matured fruits. Whereas in the Singapore cherries there is no observed feeding preference for immature or mature fruits. === Biological mechanics === Feeding requires the insertion of their stylet into the plant tissues. This insertion results in the secretion of saliva. Present within their saliva are toxic substances that cause death of plant tissues following feeding. However, the biochemical understanding of the toxin's toxicology and function within the saliva is poorly understood and is a site of current research. == Predators == Being a pest to many agricultural crops, resulting in severe destruction of plants following their consumption, have since made H. antonii a major target in hopes to reduce their prevalence in the agricultural industry. The use of insecticides and pesticides have long been used in an attempt to manage and reduce the damaging effects of H. antonii feeding. However, the effectiveness of these chemicals are concentration and volume dependent with respect to the type being used. Some of these pesticides have a prevalence of 500 liters per hectare at concentrations ranging from 50g/L-500g/L. The use of such chemical agents poses a risk not only to the environment but to humans as well—as exposure and administration levels continue to increase so too does its
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
level of toxicity. Additionally, many countries that import these crops do not import those that have traces of pesticides. Thus, natural predators and parasitoids have been looked to for their biological control properties to prevent the use of these harmful chemicals. === Biological control === H. antonii are subject to both predation and parasitism via parasitoids. Parasitoids of both nymph and adult morphs include Hymenoptera (Braconidae, Platygastridae) and Diptera (Sarcophagidae). Predators are more extensive in diversity and consist of Hymenoptera (Formicidae, Vespidae), Coleoptera, Mantodea, and Odonata. Of specific interest and use are hymenopteran parasitoids, specifically, Telenomus cupis due to their high specificity and specialization on H. antonii eggs. The employment of these parasitoid specialists has significantly decreased the abundance of H. antonii eggs to effectively reduce their devastating impact on agricultural crops. Additionally, these hymenopteran parasitoids are one of the few parasitoids that are active year-round. The combined use of pesticides and biological control agents are less effective in reducing the number of H. antonii within agricultural systems. This is because these pesticides also act against biological control agents—reducing their effectiveness. Additionally, the biological control agents tend to be more affected by pesticides than H. antonii. Biological predators and parasitoids are more affected than H. antonii due to their increase locomotory abilities causing them to be exposed to larger amounts of the synthetic pesticides found on crops. The extensive and prolonged use of pesticides and its lesser effect on H. antonii, when compared to its biological control agents, raises concerns regarding pesticide resistance. However, such evidence has yet to suggest the acquisition of pesticide resistance in H. antonii. == Ecological and economic damage == H. antonii foraging behaviour, especially on commercially produced crops, has devastating impacts on overall crop yields showing yield reduction of as much as 35-75 percent. As
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
more of the native landscape becomes converted into agricultural lands it provides an increased food supply for them. This increased food supply allows for an increase in population. As their population increases more plant tissues are subject to damage and injury. Thus, injured plants are no longer able to allocate their desired resources into fruit/seed production, rather, they are forced to allocate resources and energy into damage control and repair. This alternative allocation of resources is what causes the observed yield reductions. Poor yields result in poor economic outcomes for producers which also has adverse consequences for consumers such as increased prices, as well as an overall reduction in the number and overall quality of available products. Foraging behaviour of H. antonii causes necrotic lesions to develop on plant tissues at feeding sites which can cause the death to new plant buds. Bud death inhibits plants from producing fruit—decreasing yield. Similarly, feeding on premature and mature fruits causes fruit desiccation resulting in a reduction in size and quality—as seen in cashew plants. === Fungal contribution === Although feeding results in necrotic lesioning and desiccation, it is not the only factor that impacts yield. Following foraging, fungal pathogens can enter the wound tissues more readily and cause die-back of shoots and is the primary cause of inflorescence blight. Even though fungal blight is a common occurrence in various plants, the wounds caused by H. antonii in plant tissues exacerbates and accelerates its effects. Die-back from blight also limits the plant's ability to produce products and grow—further perpetuating yield loss. == External links == http://www.yourarticlelibrary.com/zoology/helopeltis-antonii-distribution-life-cycle-and-control/24068 http://www.nbair.res.in/insectpests/Helopeltis-antonii.php DropData cocoa pest guide Data related to Helopeltis at Wikispecies Media related to Helopeltis antonii at Wikimedia Commons == References ==
|
{
"page_id": 62395217,
"source": null,
"title": "Helopeltis antonii"
}
|
Viability PCR, also named v-PCR or vPCR, is an evolution of PCR. Through the use of a simple pre-treatment of the sample by the means of specific intercalating photo-reactive reagents it's possible to neutralize the DNA of dead cells. As a result, only DNA from live cells will be detected by PCR. This approach expands a lot the analytical scope of PCR procedures. The capability to detect only living cells become very important, because in key applications is more important to know the amount of live cells, than the total cell level. Examples of this are: food and water quality control, infectious diseases diagnostic, veterinary applications, ecological dynamics... The first referenced work about this analytical approach was in 2003, Norwegian researchers suggest the use of Ethidium Monoazide, an azide form of Ethidium Bromide, which was used in other analytical fields as Flow Cytometry as a candidate for viability PCR. However, the main important advances were done by Nocker and colleagues, which demonstrated in successive works the potential of this technology and also suggested Propidium monoazide as a better reagent for vPCR. This field still is in development, from 2003 up to 2015, the scientific evidences about the applicability of vPCR are stacking, nowadays main efforts are focused in procedure optimization. Since a simple reagent mix with the sample, photo-activation and subsequent PCR not always shows expected results, each procedure needs some optimization. Up to now the main improvements has been : - Improving the efficiency of photo activation: early procedures were based on high power halogen lamps which overheated the samples and don't ensured constant light dose, these home made solutions have been replaced by led based instruments.[1][2] - The use of long PCR amplicons as targets. - The increase of temperature during dark incubation. Through combining different optimizations strategies
|
{
"page_id": 48698195,
"source": null,
"title": "Viability PCR"
}
|
and controlling the analytical bias, nowadays the vPCR becomes a powerful analytical tool. == References ==
|
{
"page_id": 48698195,
"source": null,
"title": "Viability PCR"
}
|
Esterase D may refer to: Methylumbelliferyl-acetate deacetylase, an enzyme Carboxylesterase, an enzyme
|
{
"page_id": 38998868,
"source": null,
"title": "Esterase D"
}
|
In theoretical physics the Hanany–Witten transition, also called the Hanany–Witten effect, refers to any process in a superstring theory in which two p-branes cross resulting in the creation or destruction of a third p-brane. A special case of this process was first discovered by Amihay Hanany and Edward Witten in 1996. All other known cases of Hanany–Witten transitions are related to the original case via combinations of S-dualities and T-dualities. This effect can be expanded to string theory, 2 strings cross together resulting in the creation or destruction of a third string. == The original effect == The original Hanany–Witten transition was discovered in type IIB superstring theory in flat, 10-dimensional Minkowski space. They considered a configuration of NS5-branes, D5-branes and D3-branes which today is called a Hanany–Witten brane cartoon. They demonstrated that a subsector of the corresponding open string theory is described by a 3-dimensional Yang–Mills gauge theory. However they found that the string theory space of solutions, called the moduli space, only agreed with the known Yang-Mills moduli space if whenever an NS5-brane and a D5-brane cross, a D3-brane stretched between them is created or destroyed. They also presented various other arguments in support of their effect, such as a derivation from the worldvolume Wess–Zumino terms. This proof uses the fact that the flux from each brane renders the action of the other brane ill-defined if one does not include the D3-brane. === The S-rule === Furthermore, they discovered the S-rule, which states that in a supersymmetric configuration the number of D3-branes stretched between a D5-brane and an NS5-brane may only be equal to 0 or 1. Then the Hanany-Witten effect implies that after the D5-brane and the NS5-brane cross, if there was a single D3-brane stretched between them it will be destroyed, and if there was not
|
{
"page_id": 20124501,
"source": null,
"title": "Hanany–Witten transition"
}
|
one then one will be created. In other words, there cannot be more than one D3 brane that stretches between a D5 brane and an NS5 brane. == Generalizations == === (p,q) 5-branes === More generally, NS5-branes and D5-branes may form bound states known as (p,q) 5-branes. The above argument was extended in Branes and Supersymmetry Breaking in Three Dimensional Gauge Theories to the case of a (p,q) and a (p',q') 5-brane which cross. The authors found that the number of D3-branes created or destroyed must be equal to pq'-p'q. Furthmore they showed that this leads to a generalized S-rule, which states that in a supersymmetric configuration the number of D3-branes never goes negative upon crossing two 5-branes. If it does go negative, then the gauge theory exhibits spontaneous supersymmetry breaking. === Dual forms of the effect === Via a series of T-dualities one obtains the result that in any type II superstring theory, when an NS5-brane and a Dp-brane cross one necessarily creates or destroys a D(p-2)-brane. Lifting this statement to M-theory one finds that when two M5-branes cross, one creates or destroys an M2-brane. Using S-duality one may obtain transitions without NS5-brane. For example, when a D5-brane and a D3-cross one creates or destroys a fundamental string. == References ==
|
{
"page_id": 20124501,
"source": null,
"title": "Hanany–Witten transition"
}
|
Sebastian Hiram Shaw is a supervillain appearing in American comic books published by Marvel Comics. He has been frequently depicted as an adversary of the X-Men. A mutant, Shaw possesses the ability to absorb energy and transform it into his own raw strength. He is the leader of the New York branch of the Hellfire Club, an exclusive secret society composed of mutants bent on world domination, although to the public, he is a legitimate businessman and ordinary human. He once funded the mutant-hunting Sentinel program to keep it under his thumb. Kevin Bacon portrays Shaw in the 2011 film X-Men: First Class. == Publication history == Created by writer Chris Claremont and artist/co-writer John Byrne, Sebastian Shaw first appeared in The Uncanny X-Men #129 (Jan. 1980), during the "Dark Phoenix Saga" storyline. John Byrne based the appearance of Sebastian Shaw on British actor Robert Shaw, who had died in 1978. == Fictional character biography == Sebastian Shaw was born in Pittsburgh, Pennsylvania. His power first manifested shortly after he was accepted to engineering school and his father Jacob Shaw died after he contracted an incurable disease. Sebastian Shaw devoted himself to his studies and created Shaw Industries, becoming a millionaire by age 30 and a billionaire by age 40. === Joining the Hellfire Club === Shaw became engaged to a woman named Lourdes Chantel, also a mutant, and was soon initiated into the Hellfire Club thanks to his vast fortune along with Warren Worthington II (father of Warren Worthington III), Howard Stark (father of Tony Stark) and Sir James Braddock (father of Brian and Betsy Braddock), having caught the attention of Ned Buckman, then White King of Hellfire Club's New York branch. Shaw became part of the Council of the Chosen, earning the rank of Black Bishop. Lourdes did
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
not trust Buckman, and feared that Shaw's ambition and the nature of the Hellfire Club would corrupt him. === Taking over === Lourdes is soon seemingly killed by Sentinels in a battle. Upon discovering that Ned Buckman, the White King of the Council, is supporting Steven Lang's Project: Armageddon and its Sentinels, he executes a coup, using Emma Frost's telepathy to make Buckman kill all the Council of the Chosen, including his own White Queen, Paris Seville, and then himself. Shaw proclaims himself Black King, remakes the Council of the Chosen into his Inner Circle and gathers Emma Frost, Harry Leland and the non-mutant cyborg Donald Pierce as the Lords Cardinal of Hellfire Club. At Shaw's side is Tessa, who, unbeknownst to him, is a spy working for Charles Xavier. As the leader of the Inner Circle of the Hellfire Club, Shaw starts plans to dominate the world through force, money and power. His connections to top officials of corporations and government, acquired via the club and through his position as CEO of Shaw Industries, make him a powerful enemy. Shaw becomes a major supporter and builder of Sentinels. This activity brings him into frequent contact with the major players of Project Wideawake, Senator Robert Kelly and Henry Peter Gyrich, to whom he appears to be an anti-mutant bigot. === Meeting the X-Men === Shaw sets his eyes on the X-Men, scheming to capture and study them for use in breeding an army of powerful mutants for the Hellfire Club. He employs the superpowered assassin Warhawk to plant a bug in Cerebro, ensuring the Hellfire Club would be aware of newly manifested mutants at the same moment as the X-Men themselves, as well as giving them access to secret details of their powers and fighting techniques. However, the club's operatives
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
prove ineffective at defeating the X-Men in the field, and the first two mutants they locate in this manner are lost. Now aware of the Hellfire Club's existence, the X-Men infiltrate their headquarters, where they are defeated and captured. However, they escape before Shaw can put them to use. Shaw's control of the Hellfire Club grows more tenuous as Pierce proves to be a mutant-hating traitor, and a new recruit to the Inner Circle, Selene, sets her sights on replacing Shaw as the chairman. The Hellfire Club is forced to battle alongside the X-Men against Nimrod, a Sentinel from the future, and though victorious, two key members perish in the fight. After the battle, the Hellfire Club and the X-Men become allies of sorts, with Magneto and Storm filling the position of White King. Arguing that Shaw's support of the Sentinels is endangering the Inner Circle, Magneto, Selene and Emma vote him out of the club. === Keeping in power === Months later, Shaw was attacked by his son, Shinobi Shaw, who phased his hand into his father's chest to induce a coronary. Shaw was then supposedly blown up in his Swiss mountain chalet by a bomb set by his son. Shinobi shortly became the new Black King of Hellfire Club; however, Shaw survived, albeit with a scar on his face crossing his left eye, which was removed successfully by Madelyne Pryor (seemingly a sentient psionic construct of X-Man) using her psionic powers during their affair after his reappearance. Shaw became part of a new Inner Circle alongside Selene, Madelyne and Trevor Fitzroy, a descendant of Sebastian himself in an alternate future. Shaw's first move upon recovery from the bomb was to contact the mutant named Holocaust, who had crossed over from the "Age of Apocalypse" timeline. In exchange for
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
a new armored containment suit, Holocaust agreed to help Shaw capture X-Force, which he did with ease. Shaw then had Tessa telepathically brainwash X-Force to hunt down Cable, but Cable used his own emergent telepathy to break the conditioning and free his team. Shaw's relationship with Holocaust declined soon after. Shaw's later exploits included vying for control of the Elixir Vitae, thought to be a cure for the Legacy Virus; associations with the British intelligence agency Black Air and an unnamed time-manipulator; and hunting down X-51, the Machine Man. Then, Shaw was apparently ousted from his position as Black King by Selene, who installed the demon Blackheart in his place. This arrangement did not last long, as Selene and Blackheart were defeated and Shaw later returned to power. He attempted to use Lady Mastermind to control Tessa (now called "Sage") and Storm's team of X-Men, who were searching for Destiny's prophetic diaries. Then, after Professor X was "outed" as a mutant, Shaw apparently returned to his capitalist roots and converted the NY branch of the Hellfire Club into a strip club, which was in fact a safe haven for mutants regardless of affiliation. Using telepathic strippers, Shaw gleaned secrets from the minds of his patrons, who come in just to have a good decadent time. Thanks to the aid of his employees, Shaw pretended to be a telepath himself. After a few months, though, Shaw made a play to become the new Lord Imperial of the entire club worldwide, and invited Sage to help him. Shaw also invited Courtney Ross (who was actually her evil counterpart Sat-Yr-9) and Sunspot to join him as the White Queen and Black King. All three accepted, but Sage betrayed Shaw when she did not warn him that Pierce might try to assassinate him. Shaw
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
met with the X-Men, claiming to be somewhat reformed, just before Pierce's attack. He was then wounded by Pierce, but remained strong enough to knock the cyborg Pierce's head off. However, Shaw was too hurt to maintain his club position and was replaced by Sunspot, who became the Lord Imperial of the Hellfire Club. === Illusion === Later, it seemed he had joined forces with a new Inner Circle which included Cassandra Nova, Negasonic Teenage Warhead, and Emma Frost/Perfection, the latter of whom had since joined the X-Men. As the story arc continued to unfold, the Hellfire Club made their attack as they each targeted an individual member of Cyclops' team of X-Men. Shaw himself defeated Colossus. In the end however, it is revealed that the entire Hellfire Club was not real, and all were mental images created by Emma Frost's mind, which was infected with a special "programming" by Cassandra Nova in an attempt to revive her. The Shaw duplicate vanished after being defeated by Cyclops. === X-Men: Endangered Species === Shaw appears incognito (with an image-inducer) at a funeral for a mutant boy named Landru. When confronted by Professor X, he merely states that he was paying his respects. Xavier overhears his thoughts of a possible coup against Sunspot during the service. When Shaw notices him watching, he quickly creates a psi-shield to hide his thoughts. === Mister Sinister and the Cronus Machine === Some time after this Shaw appears at a Hellfire Club dinner hosted by Sunspot and is alerted to a device left to him by his father exploding elsewhere in the compound resulting in the insanity of two club menials and Shaw asking his manservant for a file labelled "Kronos". After being upbraided over the explosion and deaths by da Costa he is ordered to
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
investigate. Shaw however knows the cause. The explosion in the Hellfire Club was caused by the activation of a machine developed beneath the Alamogordo genetics plant in Las Cruces, New Mexico by Mister Sinister. In the past Sinister had worked here (disguised as a Dr. Milbury) alongside Brian Xavier, Kurt Marko and Irene Adler who had been gathered for him by Jacob Shaw, Sebastian's father, as they all had the X-gene and Sinister predicted their children would be mutants. Sinister then experimented of these children (including Cain Marko, Charles Xavier and Sebastian himself), imprinting himself on their DNA. Sinister's machine, dubbed the Cronus device, was designed to activate soon after his death and would activate these hidden copies until Sinister could be reborn in one of them. Jacob, wanting to protect his son, created the device in the Hellfire Club from Sinister's notes to alert and protect Sebastian from the Cronus device. Shaw travelled to New Mexico to visit another of the children to confirm his theory, running into Xavier and Gambit who were investigating a hit list with the children's names on it. Following them he is present when they are attacked by mercenaries under the employ of Amanda Mueller, a former associate of Sinister's. Xavier is captured and Gambit and Shaw team up to save Xavier. It is revealed that Mueller wants to house the powers (though not the personality) of Sinister herself and so is assassinating the children, having undergone the procedure herself. She shoots Xavier, who is already struggling to stop Sinister from taking over his body, which allows him to take over. Sinister in Xavier's body stops Mueller but is in turn confronted by Shaw and Gambit who destroy the Cronus device while Xavier casts Sinister out of his mind. With the threat gone, Shaw
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
leaves. === Original Sin === Later, Shaw joins forces with Claudine Renko, a.k.a. Miss Sinister, a female clone of Mister Sinister. Together they manipulate Wolverine into defeating the new members of the Inner Circle, try to take control of Logan's son, Daken, and set up a trap against Xavier. Shaw also attempts to kill Xavier but is stopped by Daken. Shaw is eventually confronted by Wolverine and begins to fight. Shaw's powers initially protect him from being injured by Wolverine's adamantium claws, allowing him to fare extremely well. The ending of the fight takes place off panel and Wolverine appears with his body and claws soaked with blood, which he soon confirms belongs to Shaw. === Dark Reign === During her early days as the White Queen as seen during the "Dark Reign" storyline, Sebastian Shaw sends Emma to convince Namor to join the Hellfire Club. Instead, Namor takes her to his kingdom and they begin a relationship. Believing Emma to have betrayed him for Namor, Shaw sends a reprogrammed Sentinel to Atlantis, attacking the two and destroying the kingdom. As Namor confronts Shaw for his treachery, Selene takes telepathic hold of Emma, erasing her memories of Namor, who vows revenge on Shaw. In the present, Emma reveals that her initial battle with Phoenix unlocked her memories of Namor. She makes a pact with him, seducing Shaw and using her telepathy to make Namor believe she has executed him, while secretly telepathically incapacitating Shaw. Per their deal, Namor vows to protect mutant-kind as his own people, while Emma, more determined to fill her role as a leader of mutant-kind, contacts Cyclops to have Shaw captured by the X-Men for "crimes against mutant-kind." Approaching him later in his cell, Emma reveals that she has captured Shaw for Namor and on the
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
basis that the Sentinels he commissioned were ones later used by Cassandra Nova to destroy Genosha. She sentences him to remember nothing but the faces of the Genoshan victims using her telepathy. === Necrosha === Shaw is targeted by Selene along with all those who failed her in her attempt to ascend to godhood. It is revealed that sometime after M-Day he had his son, Shinobi Shaw killed. Selene sends Shinobi and Harry Leland after Shaw and Donald Pierce. === Utopia === Due to Namor's presence on Utopia, Emma realizes that Shaw's continued existence poses a threat to the agreement she had made with Namor earlier. She decides to finally kill him, but her plans are exposed when Shadowcat accidentally picks up her thoughts during a psi-conversation between her and Colossus. While disgusted at Frost's intended actions, Shadowcat offers her a compromise. As she currently exists as a ghost, she is the perfect tool for making Shaw disappear. Fantomex, Shadowcat and Emma then take him aboard E.V.A., whilst they work out how to dispose of him. Emma wakes Shaw up and asks him to recount the early days of the Hellfire Club. Emma and two other dancers were the closest of friends, when one night, Emma was offered, by Shaw, the position of Queen. The only stipulation was that one of the two girls had to die. She stated she did not care which one was killed and watched as Shaw proceeded to kill both. Present day, Emma starts to question Shaw further when Fantomex, bored with Emma's "woe is me" recounts of her history, drops the floor from under Shaw. Emma goes into a rage at Fantomex, as Fantomex was unaware that Shaw could absorb energy, such as that from hitting the ground from such heights. Shaw proceeds to
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
engage Frost's group, stating that he would rather die than see Emma go on breathing a moment longer. Helped by a maimed Fantomex, the former White Queen tricks Shaw into allowing her into his mind, and (with a little encouragement from Shadowcat), as opposed to killing him, finds the most landlocked place in his mind, the point safest from Namor's rage, and wipes his memory. Shaw's attitude immediately changes, and he seems to have no recollection of who he is, where he is, or the identities of anyone around him. In response to his asking who she is, Emma Frost simply rebuffs him, and asks him who "he" is, coldly telling him that he always said he was a "self-made man" and now is his chance to prove it. She then leaves with the rest of her expedition, leaving a pondering Shaw kneeling in the mud. === Schism/Regenesis === Hope Summers and the Lights find Shaw, assuming him to be a new mutant. When they extract him and bring him back to Utopia, Cyclops is not exactly happy to see him. === Avengers vs. X-Men === After the Avengers invaded Utopia in Avengers vs. X-Men, Shaw along with the kids in Utopia were taken to the Avengers Academy. It is revealed that Shaw read the file on him and now knows everything about his past although he claims not to remember it. Wolverine distrusts Shaw and insists that he should be imprisoned. Shaw relents and is imprisoned in a cell that absorbs kinetic energy, meaning that Shaw would be unable to break it by building up his own kinetic energy by punching it. Shaw however, asks for books to keep him occupied and uses a book to hit himself for 8 hours straight, allowing him to build up enough energy
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
to break out of the cell and into the storm drain. Hercules, Tigra and Madison Jeffries try to stop him, but are quickly defeated. Elsewhere, the young mutants from Utopia, now joined by Ricochet, Wiz Kid and Hollow, confront the Academy students. Shortly after this, Shaw appears to the teenagers. Before a battle between both parties can become serious, X-23 and Finesse warn their friends that Shaw's body language indicates that he doesn't mean to hurt anyone, but to help the mutant children to escape. After both sides agree that the mutant children shouldn't be confined against their will, they fake a battle to justify their escape in front of the cameras at the Academy. === All-New, All-Different Marvel === In All-New, All-Different Marvel, Sebastian Shaw represents Shaw Industries during a meeting at the Universal Bank with Tiberius Stone of Alchemax, Wilson Fisk of Fisk Industries, Darren Cross of Cross Technological Enterprises, Zeke Stane of Stane International, Shingen Harada of the Yashida Corporation, Frr'dox of Shi'ar Solutions Consolidated, and Wilhelmina Kensington of Kilgore Arms. They and Dario Agger discuss his and Roxxon Energy Corporation's plans to exploit the Ten Realms of Asgard. Sebastian Shaw also saw the arrival of Exterminatrix of the Midas Foundation, who knocked out Dario and declared herself a new member of their assembly. === Residing on Krakoa === In the new phase of the X-Men, beginning with the dual miniseries House of X and Powers of X, Shaw joins the Quiet Council of Krakoa, a ruling body consisting of 14 mutants. He is also part of the Hellfire Trading Company, responsible for smuggling Krakoa's new remedies through the black market. During this new phase, he is part of the cast of the Marauders. When the anti-mutant organisation Orchis managed to mount a successful offensive on Krakoa,
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
simultaneously framing the mutants for sabotaging the drugs they had been giving humans to suggest they had been trying to kill innocent people, Shaw openly defected from Krakoa to assist Orchis. He even accepted a demand to sacrifice his mutant powers to associate with Orchis, believing that he could profit from claiming Krakoa's natural resources for himself. Unfortunately for Shaw, when he tried to use his business connections he learned that he had been kicked out of the Hellfire Club by the new White King, the Kingpin, and while he had the legal authority to control Krakoa in practise he had no access to any of its resources, and when he tried to claim the land for himself Shaw's troops were driven off by Charles Xavier, who was still residing on the island. == Powers and abilities == Shaw is a mutant with the unique ability to absorb all kinetic and thermal energy directed at him and use it to augment his strength, speed, stamina and recuperation capabilities to superhuman levels. He absorbs the energy of any impact he is struck by, including not only direct physical blows, but also the impact of bullets and throwing weapons, and less successfully, concussive energy beams; notably Cyclops' optic blasts. By absorbing successive blows from an opponent, Shaw can surpass the physical abilities of said opponent and then overpower them. His speed is the attribute most dramatically increased by his power; after absorbing enough energy he can attack more quickly than opponents can react. He is sometimes shown to be capable of absorbing the cutting, piercing and thrusting energy from a blade. His powers can enable his body to withstand cutting from adamantium, but only for a short time. In the past, Shaw has been limited to a certain amount of energy and
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
would lose consciousness when he surpassed his capabilities. Subsequently, however, Shaw has been shown to now be able to take in an indefinite amount of energy without any ill effects. The power he absorbs dissipates over time, and exposure to the elements causes it to drain rapidly. Without any absorbed energy, Shaw is merely a strong ordinary human in excellent physical condition, but regularly works to keep his strength at a superhuman level. In one instance, he was shown to spend time hitting a wall after waking to build up his power reserves before starting the day. Shaw also can forgo sleep if he receives enough energy. Often he will have his mercenaries pummel him so that he would not need to sleep for some time. Shaw also has a successful business acumen and access to sophisticated weaponry. He not only prides himself on his power and the connections it allows him, but on knowing his opponents and how best to defeat them, whether in battle or in business. He also possesses technology that can block telepathic intrusions by Professor X. == Relatives == Reverend Hiram Shaw: Sorcerer Supreme and an ambitious Puritan Reverend during the Salem Witch Trials, 1692. Sarah Shaw: Hiram's wife. Killed by Dormammu when Hiram refuses to submit to him. Obadiah Shaw: Son of Hiram and Sarah. He fell in love with Abigail Harkness, much to the disapproval of his father, who suspected her to be a witch. Abigail Harkness: Obadiah's girlfriend. She is arrested for witchcraft after Sarah's death, though Obadiah escapes and runs away with her. When the two are chased by Hiram, she reveals that she is a true witch. Elizabeth Shaw-Worthington: A teenager who fled from England when she was 13 years old. In 1780, she was taken by Lady Grey of
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
the Hellfire Club as her protégé, who wanted to use her to seduce General Wallace Worthington and extract military secrets to defeat George Washington. Elizabeth fell in love with Worthington and married him, neglecting her duties to Lady Grey. Worthington is killed by the Hellfire Club, though it is hinted that Elizabeth was already pregnant, making her an ancestor of Warren Worthington III. Brigadier-General Cornelius Shaw: A member of the Inner Circle of London's Hellfire Club and Sebastian's grandfather. Presumably a King in the London Branch Inner Circle. Esau Shaw: Cornelius Shaw's son, who was invited to take his father's place in the Hellfire Club. Killed by brother Jacob. Jacob Shaw: Cornelius Shaw's second son and Sebastian's father, who desired the place offered to Esau in the Hellfire Club. He was mutated by Mister Sinister and given limited shapeshifting powers. He kills his brother Esau after assuming the form of Waltham Pierce. After he fell sick, doctors failed to cure him due to his altered genes. Shinobi Shaw: Sebastian's son with an unnamed Japanese woman. It was later revealed that Harry Leland was Shinobi's biological father. Anthony Shaw: Black King of the Hellfire Club in Bishop's future timeline, seemingly Shinobi's son. William Shaw: Anthony Shaw's son. Trevor Fitzroy: Anthony Shaw's illegitimate son, Shinobi's grandson. Samarra Shaw: Leader of Clan Hellfire in the Chronomancer alternate future, perhaps Anthony's sister or daughter. == Reception == In 2009, Shaw was placed on a list of 100 comic book villains as #55 by IGN. == Other versions == === Age of Apocalypse === In the Age of Apocalypse, Sebastian Shaw is one of the many mutant aristocrats and a prized servant of Apocalypse. He reveals Angel's connections with the X-Men and other rebels to his master, having seen Angel talking to the former X-Man
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
Gambit. After the death of Apocalypse and the rise of his successor Weapon Omega, Shaw managed to acquire Warren Worthington III's nightclub "Haven" and remade it into his image and renamed it as Hellfire Club. The nightclub eventually became an international social club for wealthy elites, all the while trying to influence world events, in accordance with their own agenda. When Weapon Omega started resurrecting the formerly deceased Alphas, Shaw and the Hellfire Club's position was once again threatened. Shaw was later sent to prison and is killed by Donald Pierce, who slipped poison into Shaw’s drink. === Captain Britain === In Alan Moore's Captain Britain – Waiting for the End of the World, Sebastian Shaw makes contributions to help Sir James Jaspers in his cause against the superhumans of Britain. He is a pawn in a game of chess played between Merlin and his daughter. === Forever Yesterday === In the alternate universe created by the Sphinx, Shaw fights against tyranny alongside such heroes as Cannonball, Juggernaut and Beast. === House of M === In the House of M, Sebastian Shaw was granted the position of S.H.I.E.L.D. Director after he aligned himself with Magneto and helped him transform Sentinels into mutant-protecting robots using his company's money. === Mutant X === In the Mutant X universe, Shaw is still the Black King of the Hellfire Club, but is enclosed in a protective shell for reasons unknown. === Ultimate Marvel === The Ultimate Marvel version of Sebastian Shaw is also the leader of the Hellfire Club, a secret society that worships the Phoenix God. He was killed by the Phoenix. === X-Men Noir === In X-Men Noir, Shaw is a powerful politician who commands the Brotherhood. == In other media == === Television === Sebastian Shaw appears in the X-Men: The
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
Animated Series four-part episode "The Dark Phoenix", voiced by David Bryant. This version is a member of the Inner Circle Club. Shaw appears in X-Men '97, voiced by Travis Willingham. As of this series, he became a member of Genosha's ruling council before he is killed amidst a Sentinel invasion. Sebastian Shaw appears in Wolverine and the X-Men, voiced by Graham McTavish. This version is a member of the Inner Circle. === Film === Sebastian Shaw appears in X-Men: First Class, portrayed by Kevin Bacon. This version possesses the additional ability to utilize kinetic energy as sustenance, maintain his youth and life, and fire energy blasts. Additionally, he is fluent in English, German, French, and Russian and previously operated as Nazi scientist Klaus Schmidt during World War II, during which he attempted to experiment on a young Erik Lehnsherr to test out his mutant abilities. Sometime after the war, Shaw went on to acquire a helmet from the Soviet Union capable of blocking telepaths' powers and became the leader of the Hellfire Club in the hopes of exploiting the Cuban Missile Crisis to incite World War III in a Darwinian plot to accelerate the emergence of mutants. Ultimately, he is foiled by Moira MacTaggert's Division X and killed by Lehnsherr, who takes the helmet for himself and unites the Hellfire Club's remnants under his leadership. === Video games === Sebastian Shaw appears as the final boss of X-Men. Sebastian Shaw appears in X-Men Legends II: Rise of Apocalypse, voiced by Alan Shearman. Sebastian Shaw appears as a boss in Marvel: Avengers Alliance. Sebastian Shaw appears in Marvel Snap. === Miscellaneous === Sebastian Shaw appears in The Legacy Quest novel trilogy, written by Steve Lyons. He forms a reluctant alliance with the X-Men to face various menaces while waiting for an
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
opportunity to seize control of a possible cure for the Legacy Virus. == References == == External links == Sebastian Shaw at Marvel.com Sebastian Shaw (House of M) at Marvel.com Sebastian Shaw: The Virtue of Selfishness at UncannyXmen.net
|
{
"page_id": 398166,
"source": null,
"title": "Sebastian Shaw (character)"
}
|
In geometry, Hesse's principle of transfer (German: Übertragungsprinzip) states that if the points of the projective line P1 are depicted by a rational normal curve in Pn, then the group of the projective transformations of Pn that preserve the curve is isomorphic to the group of the projective transformations of P1 (this is a generalization of the original Hesse's principle, in a form suggested by Wilhelm Franz Meyer). It was originally introduced by Otto Hesse in 1866, in a more restricted form. It influenced Felix Klein in the development of the Erlangen program. Since its original conception, it was generalized by many mathematicians, including Klein, Fano, and Cartan. == References == === Original reference === Hesse, L. O. (1866). "Ein Uebertragungsprinzip", Crelle's Journal. == Further reading == Hawkins, Thomas (1988). "Hesses's [sic] principle of transfer and the representation of Lie algebras", Archive for History of Exact Sciences, 39(1), pp. 41–73.
|
{
"page_id": 50664282,
"source": null,
"title": "Hesse's principle of transfer"
}
|
A buckling is a form of hot-smoked herring similar to the kipper and the bloater. The head and guts are removed but the roe or milt remain. They may be eaten hot or cold. == Terminology == The name comes from the German word bückling or the Swedish böckling, both words denoting a type of hot-smoked herring and is a reference to its bad smell reminiscent of the smell of a buck. == Bucklings, bloaters and kippers == All three are types of smoked herring. Bucklings are hot-smoked whole; bloaters are cold-smoked whole; kippers are split, gutted and then cold-smoked. == See also == == References == == External links == Rigby’s Encyclopaedia of the Herring: Buckling
|
{
"page_id": 8262492,
"source": null,
"title": "Buckling (fish)"
}
|
Regnier de Graaf (English spelling), original Dutch spelling Reinier de Graaf, or Latinized Reijnerus de Graeff (30 July 1641 – 17 August 1673), was a Dutch physician, physiologist and anatomist who made key discoveries in reproductive biology. He specialized in iatrochemistry and iatrogenesis, and was the first to develop a syringe to inject dye into human reproductive organs so that he could understand their structure and function. == Biography == De Graaf was born in Schoonhoven in a Roman Catholic family, as the son of a carpenter/engineer (equivalent to a modern architect). He studied medicine in Leuven (1658), Utrecht and Leiden (1663). There his co-students were Jan Swammerdam, Niels Stensen, Ole Borch and Frederik Ruysch, cooperating with professor Franciscus Sylvius, Johannes van Horne and Lucas Schacht. All of them were interested in the organs of procreation and influenced by Rene Descartes' iatrophysical approach. He submitted his doctoral thesis on the pancreas, and in 1665 he went (together with his brother) to France where he further experimented on dogs, cooperating with Pierre Bourdelot. He obtained his medical degree from the University of Angers with Jean Chapelain as his translator. Back in the Dutch Republic, De Graaf established himself at Oude Delft. He was studying the male genitalia, which led to a publication in 1668. For his research in the anatomical theatre on the ovarian follicle he used female rabbits. (The dissection of corpses was only done in winter, and cadavers were scarce; most were sent to Leiden and available when someone was condemned to death.) In May 1672 he married Maria van Dijk. As a correspondent of the Royal Society in London, De Graaf recommended (at the end of April) Henry Oldenburg that attention should be paid to autodidact Antonie van Leeuwenhoek and his work on the improvement of the microscope.
|
{
"page_id": 1446750,
"source": null,
"title": "Regnier de Graaf"
}
|
De Graaf died on 17 August and was buried respectfully on 21 August in the nearby Old Church, Delft on a prominent spot, at the choir. It has been speculated that he may have committed suicide, but it is more likely it was malaria, typhoid fever or dysentery as in other Dutch cities; the disease persisted throughout the year, peaking in July and August. == Legacy == De Graaf's position in the history of reproduction is unique, summarising the work of anatomists before his time, but unable to benefit from the advances about to be made by microscopy, although he reported its use by Antonie van Leeuwenhoek in 1673. His personal contributions include the description of testicular tubules, the efferent ducts, and corpora lutea. De Graaf may have been the first to understand the reproductive function of the fallopian tube, described the hydrosalpinx, linking its development to female infertility. De Graaf also invented a practical syringe, described in his third treatise. === Graafian follicles === His eponymous legacy are the Graafian (or ovarian) follicles. He himself pointed out that he was not the first to describe them, but described their development. From the observation of pregnancy in rabbits, he concluded that the follicle contained the oocyte, although he never observed it. The mature stage of the ovarian follicle is called the Graafian follicle in his honor, although others, including Fallopius, had noticed the follicles previously (but failed to recognize its reproductive significance). The term Graafian follicle followed the introduction of the term ova Graafiana by Albrecht von Haller who like De Graaf still assumed that the follicle was the oocyte itself, although De Graaf realized the ovum was much smaller. The discovery of the human egg was eventually made by Karl Ernst von Baer in 1827. De Graaf's contemporary Jan
|
{
"page_id": 1446750,
"source": null,
"title": "Regnier de Graaf"
}
|
Swammerdam confronted him after his publication of DeMulierum Organis Generatione Inservientibu and accused him of taking credit of discoveries he and Johannes van Horne had made earlier regarding the importance of the ovary and its eggs. De Graaf issued a rebuttal but was affected by the accusation of plagiarism. === Female ejaculation === De Graaf described female ejaculation and referred to an erogenous zone in the vagina that he himself linked with the male prostate; this zone was later reported by German gynecologist Ernst Gräfenberg and named after him as the Gräfenberg Spot or G-Spot. Further, De Graaf described the anatomy of the testicles and collected secretions of the gall bladder and the pancreas. === Weaknesses === Despite his contributions, De Graaf made a number of errors in addition to believing that the ovum was the follicle. He never actually consulted the ancient texts but merely repeated the accounts of others compounding their inaccuracies. Because he observed rabbits rather than humans, he assumed fertilization took place in the ovary. He believed that the seminal vesicles stored spermatozoa. He was not yet aware of the presence of spermatozoa as such; these were discovered just after his death by the Amsterdam student Johannes Ham, using the microscope of Antonie van Leeuwenhoek. Based upon his rabbit experiments and the description of ectopic pregnancy in a lady that had died in her 12th pregnancy in Paris, he assumed that the complete entity was present in the ovary, brought to life by the influence of the male ejaculatory fluid, and then transported to the uterus. == Publications == De Graaf, R (1664) De succi pancreatici natura et usu exercitatio anatomico-medica De Graaf, R (1668) De Virorum Organis Generationi Inservientibus, de Clysteribus et de Usu Siphonis in Anatomia De Graaf, R (1672) De mulierum organis generationi
|
{
"page_id": 1446750,
"source": null,
"title": "Regnier de Graaf"
}
|
inservientibus tractatus novus : demonstrans tam homines & animalia caetera omnia, quae vivipara dicuntur, haud minus quàm ovipara ab ovo originem ducere De Graaf, R (1686) Alle de Wercken. Leyden, Netherlands. == References == == Other sources == Houtzager HL. Reinier de Graaf 1641–1673 (Dutch). Rotterdam: Erasmus publishing, 1991. ISBN 90-5235-021-3. Houtzager HL (2000). "Reinier De Graaf and his contribution to reproductive biology". European Journal of Obstetrics, Gynecology, and Reproductive Biology. 90 (2): 125–7. doi:10.1016/S0301-2115(00)00258-X. PMID 10825629. Modlin IM; Director Gastric Pathobiology Group (2000). "Regnier de Graaf: Paris, purging, and the pancreas". Journal of Clinical Gastroenterology. 30 (2): 109–13. doi:10.1097/00004836-200003000-00001. PMID 10730914. Longo LD; Degraaf, R (1996). "De mulierum organis generationi inservientibus tractatus novus". American Journal of Obstetrics and Gynecology. 174 (2): 794–5. doi:10.1016/S0002-9378(96)70467-2. PMID 8623824. Wiesemann C (1991). "Regnier de Graaf (1641–1673)" [Regnier de Graaf (1641–1673)]. Der Pathologe (in German). 12 (6): 352–3. PMID 1792221. Houtzager HL (1981). "Reinier de Graaf". European Journal of Obstetrics, Gynecology, and Reproductive Biology. 12 (6): 385–7. doi:10.1016/0028-2243(81)90083-6. PMID 7037492. Gysel C (1978). "Reinier de Graaf (1641–1673) and the syringe" [Reinier de Graaf (1641–1673) and the syringe]. Nederlands Tijdschrift voor Tandheelkunde (in Dutch). 85 (5): 216–8. PMID 379667. Mann RJ (1976). "Regnier de Graaf, 1641–1673, investigator". Fertility and Sterility. 27 (4): 466–8. doi:10.1016/s0015-0282(16)41788-7. PMID 773713. Lindenboom GA (May 1974). "Reinier de Graaf (1641–1673)" [Reinier de Graaf (1641–1673)]. Nederlands Tijdschrift voor Geneeskunde (in Dutch). 118 (21): 789–95. PMID 4597505. "Reinier de Graaf and the Royal Society of London" [Reinier de Graaf and the Royal Society of London]. Nederlands Tijdschrift voor Geneeskunde (in Dutch). 117 (28): 1049–55. 1973. PMID 4595333. Lindberg J (1963). "Regnier de GRAAF" [Regnier de GRAAF]. Nordisk Medicin (in Swedish). 69: 108–12. ISSN 0029-1420. PMID 13930746. Ruler Han van (2003). 'Graaf, Reinier de (1641-73)' The Dictionary of 17th and 18th-Century Dutch Philosophers. Bristol:
|
{
"page_id": 1446750,
"source": null,
"title": "Regnier de Graaf"
}
|
Thoemmes, 2003, vol. 1, 348–9. ISBN 1-85506-966-0. Ruler Han van (2007). 'Graaf, Reinier de' Dictionary of Medical Biography. Westport, Conn.: Greenwood, 2007, vol. 2, 570. Speert H (1956). "Obstetric-gynecologic eponyms; Reinier de Graaf and the graafian follicles". Obstetrics and Gynecology. 7 (5): 582–8. PMID 13309944. == External links == Short biography Britannica entry
|
{
"page_id": 1446750,
"source": null,
"title": "Regnier de Graaf"
}
|
The Jean Mayer Human Nutrition Research Center on Aging (HNRCA), located in Boston, Massachusetts, is one of six human nutrition research centers in the United States supported by the United States Department of Agriculture Agricultural Research Service. The goal of the HNRCA, which is managed by Tufts University, is to explore the relationship between nutrition, physical activity, and healthy and active aging. == History == In the Food and Agriculture Act of 1977, Congress directed the Secretary of Agriculture to establish a comprehensive human nutrition research program and to study the potential cost and value of regional research centers for nutrition. The Agriculture Appropriations Bill, passed later in 1977, instructed the USDA to establish an "adult" human nutrition research facility at Tufts University in Massachusetts. On August 1, 1979, the Cooperative Agreement between Tufts University and the USDA was signed, and on October 23 of the same year, the National Institute on Aging and the USDA signed a Memorandum of Understanding detailing their mutual interest in the HNRCA at Tufts University. Tufts University donated land from its Boston campus for the HNRCA. It is run by cooperative agreement between the ARS and Tufts University. == Contributions to society == The HNRCA is one of the largest research centers in the world studying nutrition and physical activity in healthy and active aging and the prevention of age-related disease. It has made significant contributions to U.S. and international nutritional and physical activity recommendations, public policy, and clinical healthcare. These contributions include advancements in the knowledge of the role of dietary calcium and vitamin D in promoting nutrition and bone health, the role of nutrients in maintaining the optimal immune response and prevention of infectious diseases, role of diet in prevention of cancer, obesity research, modifications to the Food Guide Pyramid, contribution to
|
{
"page_id": 39326559,
"source": null,
"title": "Human Nutrition Research Center on Aging"
}
|
USDA nutrient data bank, advancements in the study of sarcopenia, heart disease, vision, brain and cognitive function, front of packaging food labeling initiatives, and research of how genetic factors impact predisposition to weight gain and various health indicators. == Center structure == The HNRCA employs 270 people, including 60 scientific researchers (holding degrees of Ph.D., M.D., M.P.H., D.V.M.) with faculty appointments at different schools at Tufts University, adjunct scientists, postdoctoral fellows, visiting scientists, ARS researchers, graduate students and other trainees, and administrative and scientific support staff. HNRCA scientists are trained in nutrition, biochemistry, genetics, medicine, endocrinology, gastroenterology, physiology, veterinary medicine, epidemiology, physics, and molecular biology. == Current research == Research clusters within the HNRCA address four specific strategic areas: 1) Cancer, 2) Cardiovascular Disease, 3) Inflammation, Immunity, and Infectious Disease and 4) Obesity. HNRCA scientists collectively average more than one high-impact scientific journal publication each business day of the year and are often cited in the media. == Internal core units == Essential scientific core services provided within the HNRCA are Biostatistics, Comparative Biology Unit, Dietary Assessment Unit, Functional Genomics, Mass Spectrometry, Metabolic Research Unit, and Nutrition Evaluation Laboratory. == Research and publications == The HNRCA scientists collectively average more than one high-impact scientific journal publication each business day of the year and receive a large amount of high-profile media exposure. == See also == USDA Agricultural Research Service == References == == External links == Jean Mayer Human Nutrition Research Center on Aging – official website === Labs === Antioxidants Body Composition Bone Metabolism Cardiovascular Nutrition Energy Metabolism Neuroscience and Aging Nutrition and Neurocognition Nutrition & Cancer Biology Nutritional Epidemiology Nutrition, Exercise, Physiology and Sarcopenia (NEPS) Nutritional Genomics Nutritional Immunology Nutrition & Vision Research Obesity Metabolism Vascular Biology Vitamins & Carcinogenesis Vitamin K Vitamin Metabolism
|
{
"page_id": 39326559,
"source": null,
"title": "Human Nutrition Research Center on Aging"
}
|
Sanitary epidemiological reconnaissance, synonym epidemiological reconnaissance is a literal name of a concept and routine of finding out disease potential on a territory of arrival of major contingent. Russian: санитарно-эпидемиологическая разведка, син. эпидемиологическая разведка. This is a kind of medical reconnaissance, process of information gathering on possible infectious diseases' origin-sources, the ways and factors of the infection transfer and determining all conditions that could have promoted the spread of infestation among army service personnel. In 1939 Academician E.N.Pavlovsky announced his "doctrine of nidality", so called by Soviet biologists. People can acquire zoonoses and insect-borne diseases when they occupy at certain times of the year natural habitat of a certain pathogen (e.g., plague, tularemia, leptospirosis, arboviruses, tick-borne relapsing fever). The WHO Expert Committee on Zoonoses listed over 100 such diseases. About natural focality of the diseases is known elsewhere. == History == Historically, Sanitary epidemiological reconnaissance implied collection and transfer of all data available on sanitary and epidemiological situation of the area of possible deployment and action of armed forces, the same data for the neighbouring and enemy armed forces. The aim for the reconnaissance was to clear up the reasons of the specific disease origin—sources of the infection in various extreme situations, including local wars and armed conflicts, the ways of the infection transfer and all factors promoting to the infestation. This practice has been successfully used on plague-endemic territory at the time of the Soviet–Japanese War (1945) in WWII : "Sanitary epidemiological reconnaissance was organized and conducted continuously for the entire depth of the operation. Mobile sanitary epidemiological detachments followed immediately behind the first echelon of tanks and mechanized vehicles of advancing Soviet army should they encounter any particular contagious disease. Withdrawing enemy forces had poisoned many wells and water sources". After the armed forces have become stationary during
|
{
"page_id": 35525473,
"source": null,
"title": "Sanitary epidemiological reconnaissance"
}
|
wartime and emergency of peace time the sanitary epidemiological reconnaissance turns into sanitary and epidemiological surveillance and medical control of vital and communal activity of the armed forces. == Difference from Epidemic Intelligence Service == Sanitary epidemiological reconnaissance as a practice has nothing in common with the Epidemic Intelligence Service as an educational program of the United States' Centers for Disease Control and Prevention (CDC). The latter was established in 1951 by Alexander Langmuir, due to biological warfare concerns arising from the Korean War, it has become a hands-on two-year postgraduate training program in epidemiology. == International recognition == The use of sanitary epidemiological reconnaissance or similar practices in the armed forces is mentioned elsewhere. The Polish contingents serving under the UN auspices focused their tasks among others on ... sanitary-epidemiological reconnaissance ... . The similar practice is recognized by the WHO and Australia while encompassing chemical, radiological hazards as well. They call it "All-hazards approach" US Department of Health and Human Services in the page 300 of its manual in admits existence of other surveillance systems calling them "early-warning systems of disease potential" with the aim to collect data on indicators of disease or disease potential: animal population (animal morbidity and mortality by a disease that can affect humans, the presence of a disease agent in wild and domestic sentinel animals, vectors of a disease) and environmental data. == Conduction of the reconnaissance == There is a definite need in mobile sanitary-epidemiological groups, trained and equipped for the task. Any group for sanitary epidemiological reconnaissance includes: epidemiologist, specialist on infections, assistant of epidemiologist (bacteriologist-lab assistant), medical orderly (if necessary, the group will include zoologist or parasitologist). These units should be formed up in the deployable medical set-ups. Sanitary-epidemiological reconnaissance should result in revealing of the patients and persons, suspected
|
{
"page_id": 35525473,
"source": null,
"title": "Sanitary epidemiological reconnaissance"
}
|
to the specific disease, their isolation and hospitalization. A sanitary-epidemiological kit is constructed, consisting of two separate units, but each adaptable to use with the other: a portable laboratory kit and a portable combination lab apparatus. The two units can be useful in the work of epidemiologists during sanitary-epidemiological reconnaissance and sanitary epidemiological surveys. == In the 21st century == In 2010 at The Meeting of the States Parties to the Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and Their Destruction in Geneva the sanitary epidemiological reconnaissance was suggested as well-tested means for enhancing the monitoring of infections and parasitic agents, for practical implementation of the International Health Regulations (2005). The aim was to prevent and minimize the consequences of natural outbreaks of dangerous infectious diseases as well as the threat of alleged use of biological weapons against BTWC States Parties. It is pointed out the significance of the sanitary epidemiological reconnaissance in assessing the sanitary-epidemiological situation, organizing and conducting preventive activities, indicating and identifying pathogenic biological agents in the environmental sites, conducting laboratory analysis of biological materials, suppressing hotbeds of infectious diseases, providing advisory and practical assistance to local health authorities. Sanitary epidemiological reconnaissance (inspection) or a similar practice and specific indication in the hotbed should be performed immediately after the receiving of the information about bio-terrorism attack. There were compiled the principles of organization of sanitary epidemiological reconnaissance and criteria for evaluating the sanitary epidemiological status of arms force and regions of their dislocation. == References == == Further reading == Langmuir, A D (1980). "The Epidemic Intelligence Service of the Center for Disease Control". Public Health Reports. 95 (5): 470–7. PMC 1422746. PMID 6106957. LANGMUIR, A D; ANDREWS J M (March 1952). "Biological warfare defense. 2. The Epidemic
|
{
"page_id": 35525473,
"source": null,
"title": "Sanitary epidemiological reconnaissance"
}
|
Intelligence Service of the Communicable Disease Center". American Journal of Public Health and the Nation's Health. 42 (3): 235–8. doi:10.2105/AJPH.42.3.235. PMC 1526024. PMID 14903237.
|
{
"page_id": 35525473,
"source": null,
"title": "Sanitary epidemiological reconnaissance"
}
|
Pacific Conservation Biology is a peer-reviewed scientific journal published by CSIRO Publishing and dedicated to conservation and wildlife management in the Pacific region. It publishes original research, reviews, perspectives and book reviews. Pacific Conservation Biology was established in June 1993 by Surrey Beatty & Sons, a private independent publisher. The Society for Conservation Biology Board of Governors approved a Memorandum of Understanding promoting collaboration due to the similar interest of their organisation and Surrey Beatty. The journal was taken over by CSIRO Publishing in 2015. The current editor-in-chief is Mike Calver (Murdoch University). == Abstracting and indexing == The journal is abstracted and indexed in BIOSIS Previews, CAB Abstracts, Embiology, GEOBASE, Scopus and Zoological Record. == References == == External links == Official website Society for Conservation Biology ISSN 1038-2097
|
{
"page_id": 25170787,
"source": null,
"title": "Pacific Conservation Biology"
}
|
In loop quantum gravity, an s-knot is an equivalence class of spin networks under diffeomorphisms. In this formalism, s-knots represent the quantum states of the gravitational field. == External links == Living Reviews in Relativity: Loop Quantum Gravity: Diffeomorphism invariance Rovelli, Carlo (1996-10-14). "Black Hole Entropy from Loop Quantum Gravity". Physical Review Letters. 77 (16): 3288–3291. arXiv:gr-qc/9603063v1. doi:10.1103/physrevlett.77.3288. ISSN 0031-9007. PMID 10062183. S2CID 43493308.
|
{
"page_id": 7803747,
"source": null,
"title": "S-knot"
}
|
A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory. Almost all predatory fishes (most sharks, tuna, billfishes, pikes etc.) are obligated piscivores. Some non-piscine aquatic animals, such as whales, sea lions, and crocodilians, are not completely piscivorous; often also preying on invertebrates, marine mammals, waterbirds and even wading land animals in addition to fish, while others, such as the bulldog bat and gharial, are strictly dependent on fish for food. Some creatures, including cnidarians, octopuses, squid, cetaceans, spiders, grizzly bears, jaguars, wolves, snakes, turtles and sea gulls, may have fish as significant if not dominant portions of their diets. Humans can live on fish-based diets, as can their carnivorous domesticated pets such as dogs and cats. == Etymology == The name piscivore is derived from Latin piscis 'fish' and vorō 'to devour'. Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". == Discussion == The ecological effects of piscivores can extend to other food chains. In a study of cutthroat trout stocking, researchers found that the addition of this piscivore can have noticeable effects on non-aquatic organisms, in this case bats feeding on insects emerging from the water with the trout. Another study done on lionfish removal to maintain low densities used piscivore densities as a biological indicator for coral reef success. There exist classifications of primary and secondary piscivores. Primary piscivores, also known as "specialists", shift to this habit in the first few months of their lives. Secondary piscivores will move to eating primarily fish later in their lifetime. It is hypothesized that the secondary piscivores' diet change is due to an
|
{
"page_id": 6755173,
"source": null,
"title": "Piscivore"
}
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.