Slow-wave potential

A slow wave potential is a rhythmic electrophysiological event in the gastrointestinal tract. The normal conduction of slow waves is one of the key regulators of gastrointestinal motility. Slow waves are generated and propagated by a class of pacemaker cells called the interstitial cells of Cajal, which also act as intermediates between nerves and smooth muscle cells. Slow waves generated in interstitial cells of Cajal spread to the surrounding smooth muscle cells and control motility.
Description.
In the human Enteric Nervous System, the slow-wave threshold is the potential which must be reached before a slow wave can be propagated in gut wall smooth muscle. Slow waves themselves seldom cause any smooth muscle contraction (Except for, probably in the stomach). When the amplitude of slow waves in smooth muscle cells reaches a certain threshold—the slow-wave threshold—the L-type Ca2+ channels are activated, resulting in calcium influx and initiation of motility.
Slow waves are generated at unique intrinsic frequencies by the interstitial cells of Cajal, even within the same organ. Entrainment of these different intrinsic frequencies through electrical coupling allows these unique intrinsic frequencies to occur at a single frequency within the stomach and segments of the small intestine. Electron microscopic and dye coupling studies to date have confirmed gap junctions as the major coupling mechanisms between interstitial cells of Cajal.
Coupling between ICC and smooth muscle cells is uncertain. Gap junctions have been demonstrated in rare circumstances as one coupling mechanism between ICC and smooth muscle cells. Another potential coupling mechanism is the “Peg and Socket” theory which demonstrates that the membranes of smooth muscle cells have the ability either form physical narrow “sockets” or “pegs” to lock onto other smooth muscle cells and/or interstitial cells of Cajal.
Types.
Gastric slow waves occur at around 3 cycles-per-minute in humans and exhibit significance variances in both amplitudes and propagation velocities in the stomach due to the existence of a gradient of resting membrane potential gradient, interstitial cells of Cajal distributions, and gastric wall thickness. Gastric slow waves frequency, propagation velocity, and amplitude demonstrate significant inter-species differences. Extracellular bioelectrical recording studies have demonstrated that gastric slow waves originate from a pacemaker region located on the greater curvature of the stomach. Human gastric slow waves propagate slower in the corpus than in the pacemaker region and antrum of the stomach. Up to four simultaneous slow wave wavefronts can occur in the human stomach.
Intestinal slow waves occur at around 12 cycles-per-minute in the duodenum, and decreases in frequency towards the colon. Entrainment of intestinal slow waves forms “frequency plateaus” in a piece-wise manner along the intestine. Similar to the stomach, intestinal slow waves frequency, propagation velocity, and amplitude also demonstrate significant inter-species differences.
In uterine smooth muscle, slow waves have not been consistently observed. Uterine muscle seems to generate action potentials spontaneously.
In gastrointestinal smooth muscle, the slow-wave threshold can be altered by input from endogenous and exogenous innervation, as well as excitatory (acetylcholine and Substance P) and inhibitory (vasoactive intestinal peptide and nitric oxide) compounds.
References.
Textbook of Medical Physiology - Gyton and Hall (12th edition)


Nandi bear

In east African folklore, the Nandi bear is a creature said to live in East Africa. It takes its name from the Nandi people who live in western Kenya, in the area the Nandi Bear is reported from. It is also known as Chemosit, Kerit, Koddoelo, Ngoloko, or Duba (which derives from the Arabic words "dubb" or "d.abʕ" / "d.abuʕ" for 'bear' and 'hyena' respectively). The Samburu "Nkampit" appears also to be a version of this creature.
Description.
Descriptions of the Nandi bear are of a ferocious, powerfully built carnivore with high front shoulders (over four feet tall) and a sloping back. Stories of the Nandi bear state that it is fierce, nocturnal, stands on its hind legs and can kill animals. Charles William Hobley authored a diagram of its supposed foot in 1913.
The Nandi people call it "kerit". Local legend holds that the Nandi bear has reddish hair, long feet and is said to scalp people. In 1961, Gardner Soule noted that sightings were reported in Kenya throughout the 19th century and early 20th century but it has "never has been caught or identified". Sightings of the Nandi bear decreased over time. In 1983, Richard Meinertzhagen speculated that it may have been an "anthropoid ape now extinct on account of decreased rainfall."
Scientific evaluation.
There is no scientific evidence that the Nandi bear exists. Alleged sightings are suggested to be misidentification of known species.
In 1923, Charles William Andrews suggested that the Nandi bear may be a surviving representative of the extinct Chalicothere. In the 1930s Louis Leakey suggested that Nandi Bear descriptions matched that of the Chalicothere, though chalicotheres were herbivores. The Chalicothere hypothesis was later abandoned. In 2000, paleontologist Louis L. Jacobs commented that "if chalicotheres existed now, they would have been found out just like the giant forest hog was." He concluded that "if there is anything to the Nandi-bear story besides imagination, I suspect it may be the word-of-mouth description of gorillas passed across the continent from areas where they live to areas where they do not."
Zoologist Reginald Innes Pocock claimed that reports of the Nandi bear were misidentified hyena, specifically the Spotted hyena. In 1932, the Natural History Museum stated that many reports of the Nandi Bear have "proved to have been nothing more than a spotted hyena." Paleontologist George Gaylord Simpson attributed sightings of the Nandi bear to the honey badger or ratel. Simpson commented that the Nandi bear "turned out to be in most if not all cases a ratel, an animal which had been known to scientific zoologists since 1776."


Development of the gonads

The development of the gonads is part of the prenatal development of the reproductive system and ultimately forms the testes in males and the ovaries in females. The gonads initially develop from the mesothelial layer of the peritoneum.
The ovary is differentiated into a central part, the medulla, covered by a surface layer, the germinal epithelium. The immature ova originate from cells from the dorsal endoderm of the yolk sac. Once they have reached the gonadal ridge they are called oogonia. Development proceeds and the oogonia become fully surrounded by a layer of connective tissue cells (pre-granulosa cells). In this way, the rudiments of the ovarian follicles are formed.
In the testis, a network of tubules fuse to create the seminiferous tubules. Via the rete testis, the seminiferous tubules become connected with outgrowths from the mesonephros, which form the efferent ducts of the testis. The descent of the testes consists of the opening of a connection from the testis to its final location at the anterior abdominal wall, followed by the development of the gubernaculum, which subsequently pulls and translocates the testis down into the developing scrotum. Ultimately, the passageway closes behind the testis. A failure in this process causes an indirect inguinal hernia.
Germ cells migrate from near the allantois and colonize the primordial gonads. In the female, the germ cells colonise the cortex and become oogonia. In the male, the germ cells colonise the seminiferous cords of the medulla, becoming spermatogonia.
Before differentiation.
The first appearance of the gonad is essentially the same in the two sexes, and consists in a thickening of the mesothelial layer of the peritoneum. The thick plate of epithelium extends deeply, pushing before it the mesoderm and forming a distinct projection. This is termed the gonadal ridge. The gonadal ridge, in turn, develops into a gonad. This is a testis in the male and an ovary in the female.
At first, the mesonephros and gonadal ridge are continuous, but as the embryo grows the gonadal ridge gradually becomes pinched off from the mesonephros. However, some cells of mesonephric origin join the gonadal ridge. Furthermore, the gonadal ridge still remains connected to the remnant of that body by a fold of peritoneum, namely the mesorchium or mesovarium. About the seventh week the distinction of sex in the gonadal ridge begins to be perceptible.
Ovary.
The ovary is thus formed mainly from the genital ridge and partly from the mesonephros. Later the mass is differentiated into a central part, the medulla of ovary, covered by a surface layer, the germinal epithelium. Between the cells of the germinal epithelium a number of larger cells, the immature ova, are found. The immature ova, in turn, are carried into the stroma beneath by bud-like ingrowths ("genital cords of the germinal epithelium"). The surface germinal epithelium ultimately forms the permanent epithelial covering of this organ. Furthermore, it soon loses its connection with the central mass. Instead, the tunica albuginea of the ovaries develops between them.
Origin of ova.
During early embryonic development, cells from the dorsal endoderm of the yolk sac migrate along the hindgut to the gonadal ridge. These primordial germ cells (PGCs) multiply by mitosis and once they have reached the gonadal ridge they are called oogonia (diploid stem cells of the ovary).
Once oogonia enter this area they attempt to associate with the other somatic cells, derived from both the peritoneum and mesonephros. Development proceeds and the oogonia become fully surrounded by a layer of connective tissue cells (pre-granulosa cells) in an irregular manner. In this way, the rudiments of the ovarian follicles are formed.
Origin of granulosa cells.
The embryological origin of granulosa cells remains controversial. In the 1970s, evidence emerged that the first cells to make contact with the oogonia were of mesonephric origin. It was suggested that mesonephric cells already closely associated with the oogonia proliferated throughout development to form the granulosa cell layer.
Recently this hypothesis has been challenged with some thorough histology. Sawyer et al. hypothesized that in sheep most of the granulosa cells develop from cells of the mesothelium (i.e., epithelial cells from the presumptive surface epithelium of the ovary).
Descent of the ovaries.
Just as in the male, there is a gubernaculum in the female, which effects a considerable change in the position of the ovary, though not so extensive a change as in that of the testis. The gubernaculum in the female lies in contact with the fundus of the uterus and adheres to this organ, and thus the ovary can only descend as far as to this level. The part of the gubernaculum between the ovary and the uterus ultimately becomes the proper ovarian ligament, while the part between the uterus and the labium majus forms the round ligament of the uterus. A pouch of peritoneum analogous to the vaginal process in the male accompanies it along the inguinal canal: it is called the canal of Nuck.
Pathology.
In rare cases, the gubernaculum may fail to contract adhesions to the uterus, and then the ovary descends through the inguinal canal into the labium majus; under these circumstances, its position resembles that of the testis.
Testis.
The testis is developed in much the same way as the ovary, originating from mesothelium as well as mesonephros. Like the ovary, in its earliest stages it consists of a central mass covered by a surface epithelium. In the central mass a series of cords appear, and the periphery of the mass is converted into the tunica albuginea, thus excluding the surface epithelium from any part in the formation of the tissue of the testis. The cords of the central mass run together toward the future hilum and form a network which ultimately becomes the rete testis. On the other hand, the seminiferous tubules are developed from the cords distal to the hilum, and between them connective-tissue septa extend. Via the rete testis, the seminiferous tubules become connected with outgrowths from the mesonephros, which form the efferent ducts of the testis.
Descent of the testes.
The descent of the testes consists of the opening of a connection from the testis to its final location at the anterior abdominal wall, followed by the development of the gubernaculum, which subsequently pulls and translocates the testis down into the developing scrotum. Ultimately, the passageway closes behind the testis.
Opening of connection.
At an early period of fetal life the testes are placed at the back part of abdominal cavity, behind the peritoneum, and each is attached by a peritoneal fold, the mesorchium, to the mesonephros. From the front of the mesonephros a fold of peritoneum termed the inguinal fold grows forward to meet and fuse with a peritoneal fold, the inguinal crest, which grows backward from the antero-lateral abdominal wall. The testis thus acquires an indirect connection with the anterior abdominal wall. At the same time, a portion of the peritoneal cavity lateral to these fused folds is marked off as the future vaginal process.
Development of gubernaculum.
Also, in the inguinal crest a structure, the gubernaculum testis, makes its appearance. This is at first a slender band, extending from that part of the skin of the groin which afterward forms the scrotum through the inguinal canal to the body and epididymis of the testis. As development advances, the peritoneum enclosing the gubernaculum forms two folds, one above the testis and the other below it. The one above the testis is the plica vascularis, and contains the upper part of the gubernaculum, and ultimately also the internal spermatic vessels; the one below, the plica gubernatrix, contains the lower part of the gubernaculum.
The gubernaculum grows into a thick cord. It ends below at the abdominal inguinal ring in a tube of peritoneum, the vaginal process, which protrudes itself down the inguinal canal. By the fifth month the lower part of the gubernaculum still is a thick cord, while the upper part has disappeared. The lower part now consists of a central core of smooth muscle fibers, surrounded by a firm layer of striated muscle elements, connected, behind the peritoneum, with the abdominal wall.
Translocation.
As the testes develops, the main portion of the lower end of the gubernaculum is carried, following the skin to which it is attached, to the bottom of this pouch. Other bands are carried to the medial side of the thigh and to the perineum. The tube of peritoneum constituting the vaginal process projects itself downward into the inguinal canal, and emerges at the external inguinal ring, pushing before it a part of the obliquus internus and the aponeurosis of the obliquus externus, which form respectively the cremaster muscle and the external spermatic fascia. The vaginal process forms a gradually elongating pouch, which eventually reaches the bottom of the scrotum, and behind this pouch the testis is drawn by the growth of the body of the fetus, for the gubernaculum does not grow proportionately with the growth of other parts, and therefore the testis, being attached by the gubernaculum to the bottom of the scrotum, is prevented from rising as the body grows, and is instead drawn first into the inguinal canal and eventually into the scrotum. It seems certain also that the gubernacular cord becomes shortened as development proceeds, and this assists in causing the testis to reach the bottom of the scrotum.
Closing of connection.
By the end of the eighth month the testis has reached the scrotum, preceded by the vaginal process, which communicates by its upper extremity with the peritoneal cavity. Just before birth the upper part of the vaginal process, at the internal inguinal ring, usually becomes closed, and this obliteration extends gradually downward to within a short distance of the testis. The process of peritoneum surrounding the testis is now entirely cut off from the general peritoneal cavity and constitutes the tunica vaginalis.
Pathology.
If the internal inguinal ring does not close properly, then there is a risk that other contents of the abdominal cavity protrudes through the passageway and cause indirect inguinal hernia.


Perpendicular plate of palatine bone

The perpendicular plate of palatine bone is the vertical part of the palatine bone, and is thin, of an oblong form, and presents two surfaces and four borders.
Surfaces.
The nasal surface exhibits at its lower part a broad, shallow depression, which forms part of the inferior meatus of the nose. Immediately above this is a well-marked horizontal ridge, the conchal crest, for articulation with the inferior nasal concha; still higher is a second broad, shallow depression, which forms part of the middle meatus, and is limited above by a horizontal crest less prominent than the inferior, the ethmoidal crest, for articulation with the middle nasal concha. Above the ethmoidal crest is a narrow, horizontal groove, which forms part of the superior meatus.
The maxillary surface is rough and irregular throughout the greater part of its extent, for articulation with the nasal surface of the maxilla; its upper and back part is smooth where it enters into the formation of the pterygopalatine fossa; it is also smooth in front, where it forms the posterior part of the medial wall of the maxillary sinus. On the posterior part of this surface is a deep vertical groove, converted into the pterygopalatine canal, by articulation with the maxilla; this canal transmits the descending palatine vessels, and the anterior palatine nerve.
Borders.
The anterior border is thin and irregular; opposite the conchal crest is a pointed, projecting lamina, the maxillary process, which is directed forward, and closes in the lower and back part of the opening of the maxillary sinus.
The posterior border presents a deep groove, the edges of which are serrated for articulation with the medial pterygoid plate of the sphenoid. This border is continuous above with the sphenoidal process; below it expands into the pyramidal process.
The superior border supports the orbital process in front and the sphenoidal process behind. These processes are separated by the sphenopalatine notch, which is converted into the sphenopalatine foramen by the under surface of the body of the sphenoid. In the articulated skull this foramen leads from the pterygopalatine fossa into the posterior part of the superior meatus of the nose, and transmits the sphenopalatine vessels and the superior nasal and nasopalatine nerves.
The inferior border is fused with the lateral edge of the horizontal part, and immediately in front of the pyramidal process is grooved by the lower end of the pterygopalatine canal.


Puffleg

The pufflegs are hummingbirds from the genera "Eriocnemis" and "Haplophaedia". They occur in humid forest, woodland and shrub at altitudes of 1000 to 4800 m. asl in the Andes of Argentina, Bolivia, Peru, Ecuador, Colombia, and Venezuela. The males have a colorful green, coppery or blue plumage, and the females are generally somewhat duller. The most striking feature of both sexes is their dense snow-white leg puffs which consist of feather tufts that resemble woolly panties. One species - the black-thighed puffleg - is characterized by black coloured leg puffs, and another - the buff-thighed puffleg - has lightly buff-tinged leg puffs. Further common features of all species are the straight black bill and the slightly to deeply forked tail. The members of the genus "Haplophaedia" are generally duller than the members of "Eriocnemis".
While most pufflegs remain fairly common, three species (colorful puffleg, black-breasted puffleg and gorgeted puffleg) are critically endangered and one (the turquoise-throated puffleg) is possibly extinct.
Puffleg species.
In addition there were the controversial species: "Eriocnemis söderströmi", "E. isaacsoni" and "E. dyselius" which were each only known by one specimen. In the case of "E. söderströmi" it could have been either the female of "E. godini" or a hybrid between "E. luciani" and "E. nigrivestris". "E. dyselius" was nothing more than a melanistic individual of "E. cupreoventris". Today these species are considered invalid.


Macrochaeta natalensis

Macrochaeta natalensis is a polychaete which belongs to the Acrocirridae family. The body of this worm consists of a head, a cylindrical, segmented body and a tail piece. The head consists of a prostomium (part of the mouth's opening) and a peristomium (area around the mouth) and utilized paired appendages (palps, antennae and cirri).
The scientific name of this species was first published in 1996 by Hartmann-Schröder


Picocoraciae

Picocoraciae is a clade that contains the order Bucerotiformes (hornbills and hoopoes) and the clade Picodynastornithes (containing birds like kingfishers and rollers, and woodpeckers and toucans) supported by various genetic analysis and morphological studies. While these studies supported a sister grouping of Coraciiformes and Piciformes, a large scale, sparse supermatrix has suggested alternative sister relationship between Bucerotiformes and Piciformes instead.


Pantachogon

Pantachogon is a genus of hydrozoans of the family Rhopalonematidae. The genus includes three species.


Axinella

Axinella is a genus of sponges in the family Axinellidae first described in 1862 by Eduard Oscar Schmidt. Species of "Axinella" occur in the Indian and Pacific Oceans. Most of these sponges are smaller than 20 cm, and have a yellow or orange colour.
List of species.
The following species are recognized within the genus "Axinella":


Capitellidae

Capitellidae is a polychaete worm family in the subclass Scolecida.


The Kingbird (journal)


Edward Newman (entomologist)

Edward Newman (13 May 1801 – 12 June 1876) was an English entomologist, botanist and writer.
Newman was born in Hampstead into a Quaker family. Both his parents were keen naturalists, and he was further encouraged to take an interest in the natural world at his boarding school in Painswick. He left school at sixteen to join his father's business in Guildford, moving to Deptford in 1826 to take over a rope-making business. Here he met many of the leading entomologists of the day, including Edward Doubleday, and was a founder member of the Entomological Club. In 1832 he was elected as editor of the club's journal, "The Entomological Magazine", and the following year became a fellow of the Linnean Society and one of the founder members of the Entomological Society of London.
In 1840 Newman was married and published the first edition of "A History of British Ferns and Allied Plants". He became a partner in a firm of London printers, Luxford & Co., and became a printer and publisher of books on natural history and science. He later became the natural history editor of "The Field", editor of "The Zoologist" and editor of "The Entomologist". His books included "Birds-nesting" (1861), "New Edition of Montagu's Ornithological Dictionary" (1866), "Illustrated Natural History of British Moths" (1869) and "Illustrated Natural History of British Butterflies" (1871). He was also author of "The letters of Rusticus on the natural history of Godalming. Extracted from the Magazine of natural history, the Entomological magazine, and the Entomologist" (1849). The topic of these "letters" is economic entomology, some were published in Chamber's Journal.
Newman's "Attempted division of British Insects into natural orders". The Entomological Magazine 2: 379-431(1834) establishes many new families and is therefore an important work of scientific classification.
Newman viewed the skeletons of Pterosaurs not as reptiles but as marsupial bats. This was based on earlier suggestions that some pterosaur fossils showed tufts of hair, which suggested they could not be typical cold blooded reptiles. As a result he published a reconstruction of pterosaurs as hairy animals in an 1843 edition of the Zoologist. This is, as far as is known, the first reconstruction of pterosaurs as hairy warm blooded creatures, which modern research suggests was actually the case. However they are now thought to be highly evolved and warm blooded reptiles and not marsupial bats. He argued, in this rather amusing article, that it was rather "unlikely" that his ideas were correct, since authorities like Georges Cuvier and William Buckland thought pterosaurs were reptiles, but, even so, it was still "possible" that the experts were wrong and he got it right.


Voragonema tatsunoko

Voragonema tatsunoko is a species of deep sea hydrozoan.


Zygoma

The term zygoma generally refers to the zygomatic bone, a bone of the human skull commonly referred to as the cheekbone or malar bone, but it may also refer to:


African Zoology

African Zoology is a biannual peer-reviewed scientific journal that covers any aspect of zoology relevant to Africa and its surrounding oceans, seas, and islands. It is published by the Zoological Society of Southern Africa. It publishes topical reviews, full-length papers, short communications, and book reviews.
History.
The journal was established by the Zoological Society of Southern Africa in 1965 as "Zoologica Africana", which was renamed to "South African Journal of Zoology" in 1979, when the South African Bureau of Publications became its publisher. In 2000, the journal returned to the society and obtained its current name.
Abstracting and indexing.
"African Zoology" is abstracted and indexed in Biological Abstracts, Chemical Abstracts, Current Advances in Biology, GeoAbstracts, Science Citation Index, and The Zoological Record. According to the "Journal Citation Reports", the journal has a 2019 impact factor of 0.86.


Vibratome

A vibratome is an instrument used to cut thin slices of material (although, usually thicker slices than those cut in paraffin-embedded samples using a microtome). It is similar to a microtome but uses a vibrating blade to cut through tissue. The vibration amplitude, the speed, and the angle of the blade can all be controlled. Fixed or fresh tissue pieces are embedded in low gelling temperature agarose. The resulting agarose block containing the tissue piece is then attached to a metal block and sectioned while submerged in a water or buffer bath. Individual sections are then collected with a fine brush and transferred to slides or multiwell plates for staining.
Vibratome is not a generic name but a registered trademark of Leica Biosystems Richmond, Inc. in the USA.


Orchesella jurassica

Orchesella jurassica is a species of slender springtail in the family Entomobryidae.


Antrum

"This is a disambiguation page for the biological term. For the 2018 horror movie, see Antrum (film)"
In biology, antrum is a general term for a cavity or chamber, which may have specific meaning in reference to certain organs or sites in the body.
In vertebrates, it may refer specifically to:
In invertebrates, it may refer specifically to:


Coronal plane

A coronal plane (also known as the frontal plane) is any vertical plane that divides the body into ventral and dorsal (belly and back) sections.
It is one of the three main planes of the body used to describe the location of body parts in relation to each other axis.
Details.
The coronal plane is an example of a longitudinal plane, because it is perpendicular to the transverse plane. For a human, the mid-coronal plane would transect a standing body into two halves (front and back, or anterior and posterior) in an imaginary line that cuts through both shoulders. The description of the coronal plane applies to most animals as well as humans even though humans walk upright and the various planes are usually shown in the vertical orientation.
The sternal plane ("planum sternale") is a coronal plane which transects the front of the sternum.
Etymology.
The term is derived from Latin "corona" ('garland, crown'), from Ancient Greek κορώνη ("korōnē", 'garland, wreath'). The coronal plane is so-called because it lies in the direction of Coronal suture.


Hylonomoipos

Hylonomoipos is a genus of velvet worm in the Peripatopsidae family. They are found in Queensland, Australia.
Species.
The genus contains the following species:


Meixnerididae

Meixnerididae is a family of Maricola triclads.


Buchan Gulf

Buchan Gulf is an isolated, elongated Arctic fjord on Baffin Island's northeastern coast in the Qikiqtaaluk Region of Nunavut, Canada. The Inuit settlement of Pond Inlet is to the north.
Geography.
Characterized by open sea, coastal cliffs, and rocky marine shores, the gulf stretches with an elevation ranging up to above sea level.
Fauna.
It is a Canadian Important Bird Area (#NU069), an International Biological Program site (Region 9, #7-11), and a Key Migratory Bird Terrestrial Habitat site. There is a sizeable population of northern fulmars. Megafauna which can be seen in the water include polar bears, walruses, and narwhals.


Mink

Mink are dark-colored, semiaquatic, carnivorous mammals of the genera "Neovison" and "Mustela" and part of the family Mustelidae, which also includes weasels, otters, and ferrets. There are two extant species referred to as "mink": the American mink and the European mink. The extinct sea mink is related to the American mink but was much larger.
The American mink's fur has been highly prized for use in clothing. Their treatment on fur farms has been a focus of animal rights and animal welfare activism. American mink have established populations in Europe (including Great Britain) and South America. Some people believe this happened after the animals were released from mink farms by animal rights activists, or otherwise escaping from captivity. In the UK, under the Wildlife & Countryside Act 1981, it is illegal to release mink into the wild. In some countries, any live mink caught in traps must be humanely killed.
American mink are believed by some to have contributed to the decline of the less hardy European mink through competition (though not through hybridization—native European mink are in fact more closely related to polecats than to North American mink). Trapping is used to control or eliminate introduced American mink populations.
Mink oil is used in some medical products and cosmetics, as well as to treat, preserve, and waterproof leather.
Species.
The American mink ("Neovison vison") is larger and more adaptable than the European mink ("Mustela lutreola") but, due to variations in size, an individual mink usually cannot be determined as European or American with certainty without looking at the skeleton. However, all European mink have a large white patch on their upper lip, whereas only some American mink have this marking. Therefore, any mink without the patch is certainly of the American species. Taxonomically, both American and European mink were placed in the same genus "Mustela" but the American mink has since been reclassified as belonging to its own genus, "Neovison".
The sea mink "Neovison macrodon", native to the New England area, is considered to be a close relative or a subspecies of the American mink. It went extinct in the late 19th century, chiefly as a result of hunting for the fur trade.
Description.
A wild male mink weighs about and is about in length. Farm-bred males can reach . The female weighs about and reaches a length of about . The sizes above do not include the tail, which can be from .
A mink's rich glossy coat in its wild state is brown and looks silky. Farm-bred mink can vary from white to almost black, which is reflected in the British wild mink. Their pelage is deep, rich brown, with or without white spots on the underparts, and consists of a slick, dense underfur overlaid with dark, glossy, almost stiff guard hairs.
Mink show the curious phenomenon of delayed implantation. Although the true gestation period is 39 days, the embryo may stop developing for a variable period, so that as long as 76 days may elapse before the litter arrives. Between 45 and 52 days is normal. There is only one litter per year. They typically have between six and 10 kits per litter. Litters as large as 16 have been recorded at fur farms.
The maximum lifespan of a mink is usually around ten years, but rarely exceeds three years in the wild.
Diet.
Mink prey on fish and other aquatic life, small mammals, birds, and eggs; adults may eat young mink. Mink raised on farms primarily eat expired cheese, eggs, fish, meat and poultry slaughterhouse byproducts, dog food, and turkey livers, as well as prepared commercial foods. A farm with 3,000 mink may use as much as two tons of food per day.
Predators.
Great horned owls, bobcats, foxes, coyotes, wolves, and humans are all natural predators of mink. They are trapped for their fur (though the majority of mink fur on the market comes from fur farms).
Mink like to live near water and are seldom found far from riverbanks, lakes, and marshes. Even when roaming, they tend to follow streams and ditches. Sometimes they leave the water altogether for a few hundred meters, especially when looking for rabbits, one of their favorite foods. In some places, particularly in Scotland and in Iceland, they live along the seashore. Sometimes they live in towns if suitable water is available. Mink may be present at all hours, even when people are nearby.
Territory.
Mink are very territorial animals. A male mink will not tolerate another male within his territory but appears to be less aggressive towards females. Generally, the territories of both male and female animals are separate, but a female's territory may sometimes overlap with that of a male. Very occasionally, it may be totally within a male's.
The territories, which tend to be long and narrow, stretch along river banks, or around the edges of lakes or marshes. Territory sizes vary, but they can be several miles long. Female territories are smaller than those of males.
Each territory has one or two central areas (core areas) where the mink spends most of its time. The core area is usually associated with a good food supply, such as a pool rich in fish, or a good rabbit warren. The mink may stay in its core area, which can be quite small, for several days at a time, but it also makes excursions to the ends of its territory. These excursions seem to be associated with the defense of the territory against intruders. The mink likely checks for any signs of a strange mink and leaves droppings (scat) redolent of its personal scent to reinforce its territorial rights.
Human uses.
Farming.
The American mink's fur has been highly prized for use in clothing, with hunting giving way to farming. Their treatment on fur farms has been a focus of animal rights and animal welfare activism. American mink have established populations in Europe (including Great Britain) and South America, after being released from mink farms by animal rights activists, or otherwise escaping from captivity. In the UK, under the Wildlife & Countryside Act 1981, it is illegal to release mink into the wild. In some countries, any live mink caught in traps must be humanely killed.
Ireland.
There are three mink farms in Ireland, in Donegal, Kerry, and Laois. Mink farming was introduced into the country by two veterinarians. Three thousand mink were released by campaigners into the wild from a farm in the 1960s. It is estimated that there are 33,500 wild mink in Ireland.
The Irish Department of Agriculture stated in November 2020 saying that the Department of Health had advised, following the detection of coronavirus among animals on a Danish mink farm, that the roughly 120,000 farmed Irish mink should be culled. Mink farming was already due to be discontinued under the 2020 Programme for Government but the coronavirus risk had expedited the closure of the industry.
Health concerns.
Minks are among the animals that can be infected with coronaviruses. Transmission of the SARS-CoV-2 virus from minks to humans was first documented in the Netherlands by way of genetic tracing, which prompted the government to bring forward to the end of 2020 a ban on mink farming scheduled to go into effect in 2024. The United States Department of Agriculture confirmed that cases of minks infected with COVID-19 had been documented in Utah in August 2020.
In November 2020, Denmark, the world's largest producer of mink fur, announced it is to cull its mink population of 15 to 17 million to stop the spread of Cluster 5, a mutated strain of the virus, which has been linked to the animals and resulting in a mutated COVID-19 to 12 humans. The decision was later halted due to the legality of the proposed legislation.
Stereotypy.
On farms, minks are placed in battery cages, a type of soft, metal wire cage that restricts their ability to move. This often results in a condition referred to as stereotypies, an abnormal behavior. These abnormal, repetitive behaviours are a result of keeping them imprisoned, and is similar to the deterioration of mental health in humans. Stereotypies have also been noted to increase during human presence.
To attempt to eliminate stereotypies in captive mink, the Canadian National Farm Animal Care Council has implemented regulations on incorporating environmental enrichments into mink cages. Enrichments are pen-related alterations or the addition of novel objects to improve the mink's physical and psychological health. Enrichments may help reduce the onset of stereotypies, but rarely decrease or eliminate them entirely. Leaving minks alone plays a large role in the prevention of stereotypies, and the animals' well-being.


Yellowtail (fish)

A yellowtail may be any of several different species of fish. Most commonly the yellowtail amberjack "Seriola lalandi" is meant. In the context of sushi, yellowtail usually refers to the Japanese amberjack, "Seriola quinqueradiata". Other species called simply "yellowtail" include:
In addition, "yellowtail" appears in many other common names of fish:


Eupraxie Gurjanova

Eupraxie Fedorovna Gurjanova (25 January 1902, Cherepovets – 27 January 1981, Leningrad) was a Soviet hydrobiologist, carcinologist and zoogeographer, specialist in the systematics of isopod crustaceans and amphipods, doctor of biological sciences.
Life and education.
Eupraxie Gurjanova was born on 12 (25) January 1902 in Cherepovets, Novgorod province. Her father, Fedor Gurjanov, was originally from Kiev. He taught mathematics in Cherepovets real college for over 30 years and then became an inspector and received personal nobility. Gurjanova’s mother, Tatiana, was originally from Tver region. Gurjanova was the eighth of eleven children in the family.
In 1919, Gurjanova entered Kazan University, where she attended lectures by Professor Nikolay Livanov, successfully passed the exams, but soon she contracted typhus and had to interrupt studies. After the illness the following year, Gurjanova was transferred to the biological department of the Physics and Mathematics Faculty of Petrograd University where she started her scientific work in the field of hydrobiology under Professor Konstantin Deryugin. In summer 1921, together with a group of Professor Deryugin's other students, Gurjanova went to the Murmansk Biological Station of the Petrograd Society of Naturalists and was engaged in the study of coastal areas of the Kola Bay. In 1922, Gurjanova participated in a large scale and complex expedition to the White Sea. In 1923, Gurjanova continued studying the coastal areas of the Kola Bay, and from 1922 until 1925 she was an employee of Murmansk biological station where she received her first pedagogical experience.
Gurjanova graduated from Leningrad University in 1924.
From 1925 until 1929, Gurjanova studied at the graduate school of the hydrobiology laboratory of the Peterhof Institute of Natural Sciences. During this time, she was helping Professor Deryugin to conduct practical classes with students. Soon she began a course of lectures on hydrobiology.
Work.
In 1929, Gurjanova graduated from the graduate school and was transferred to work at the Zoological Institute. At the Zoological Institute Gurjanova studied two groups of crustaceans – "Isopoda" and "Amphipoda" – becoming one of world’s specialists in the field and writing capital monographies on this subject. In the 1930–1960s Gurjanova took part in many expeditions in the western part of the Pacific Ocean.
She explored marine biology, working in the White and Bering seas, Kuril and Sakhalin islands areas, and the northwestern Pacific Ocean. From 1939 to 1952 Gurjanova was a member of the department of hydrobiology and ichthyology at Leningrad State University. After the death of Professor Deryugin, she took over responsibility for the department.
Since 1946, Gurjanova was in charge of the Department of Higher Crustaceans at the Zoological Institute of the Academy of Sciences of the USSR. In 1946-1949, Gurjanova was working as a deputy chief in the Kuril-Sakhalin expedition.
In 1951, her capital report on amphipods "Bokoplavy morey SSSR (Amphipoda-Gammaridea of the seas of the USSR and adjoining waters)" was published.) In 1962, one more Gurjanova’s monography was published "Bokoplavy sevemoi chasti Tikhogo okeana (Amphipoda Gammaridea). Chasti I. (Scud shrimps (Amphipoda Gammaridea) of the northern part of the Pacific Ocean. Part 1)."
In 1956-1960, Gurjanova worked as part of the Soviet-Chinese expedition in the Yellow Sea. In 1961, she began to study the Gulf of Tonkin in the Soviet-Vietnamese expedition. Her last expeditions were on Cuba in 1963, 1965 and 1968.
Gurjanova repeatedly represented Soviet science abroad. In 1963, she was a part of the organizing committee for the Institute of Oceanology for the Cuban Academy of Sciences. In 1966, at the invitation of the Royal Society of England, Gurjanova gave a number of lectures on hydrobiology in London. In 1967, she chaired in the section of the International biological symposium in Norway and participated in the work of the IX Pacific Scientific Congress in Thailand.
During her scientific career, Gurjanova described over 260 species and subspecies of amphipods new for science (including 27 independent genera and 4 families) and published about 200 scientific papers on various issues of fauna, bionomy and biogeography of the sea. Eupraxie Gurjanova died on 27 January 1981 in Leningrad.
Following marine organisms were named in her honour: "Gurjanovella" Uschakov, 1926, "Rhizellobiopsis eupraxiae" (Zachs, 1923), "Lineus gurjanovae" Korotkevich, 1977, "Lepidepecreum gurjanovae" Hurley, 1963, "Metridia gurjanovae" Epstein, 1949, "Vitjaziana gurjanovae" Birstein & Vinogradov, 1955, "Amicula gurjanovae" Jakovleva, 1952, "Rhizolepas gurjanovae" Zevina, 1968, "Lithacrosiphon gurjanovae" Murina, 1967, "Protomedeia" "gurjanovae" Bulycheva, 1951, "Eugerda gurjanovae" Malyutina & Kussakin, 1996, "Eohaustorius gurjanovae" Bousfield & Hoover, 1995, "Onchidiopsis gurjanovae" Derjugin, 1937, "Glycinde gurjanovae" Uschakov & Wu, 1962, "Samytha gurjanovae" Ushakov, 1950, "Ritterella gurjanovae" Beniaminson, 1974.


Glyoxysome

Glyoxysomes are specialized peroxisomes found in plants (particularly in the fat storage tissues of germinating seeds) and also in filamentous fungi. Seeds that contain fats and oils include corn, soybean, sunflower, peanut and pumpkin. As in all peroxisomes, in glyoxysomes the fatty acids are oxidized to acetyl-CoA by peroxisomal β-oxidation enzymes. When the fatty acids are oxidized hydrogen peroxide (H2O2) is produced as oxygen (O2) is consumed. Thus the seeds need oxygen to germinate. Besides peroxisomal functions, glyoxysomes possess additionally the key enzymes of glyoxylate cycle (isocitrate lyase and malate synthase) which accomplish the glyoxylate cycle bypass.
Thus, glyoxysomes (as all peroxisomes) contain enzymes that initiate the breakdown of fatty acids and additionally possess the enzymes to produce intermediate products for the synthesis of sugars by gluconeogenesis. The seedling uses these sugars synthesized from fats until it is mature enough to produce them by photosynthesis.
Plant peroxisomes also participate in photorespiration and nitrogen metabolism in root nodules.


Bucket handle movement

Bucket-handle is a movement of ribs that results in change in transverse diameter of the thorax.
Definition.
One of the most important functions of ribs and diaphragm is the change in volume of thorax that helps inspiration and expiration. In general, the ribs move around two axes. As the anterior end of ribs is about 4 cm lower than the posterior end, the middle part of rib is lower than anterior and posterior ends. Movement at costovertebral joints 7 to 10 about an anteroposterior axis results in raising and lowering the middle of the rib, the Bucket-handle movement. In elevation, this increases the transverse diameter of the thorax.


Enchelion

Enchelion is an extinct genus of prehistoric bony fish that lived during the upper Cenomanian.


Inoceramus cuvieri

Inoceramus cuvieri is an extinct species of the extinct genus "Inoceramus" of Bivalve mollusks that serves as an index fossil of chalky rocks of Turonian age of the Cretaceous Period in Europe and North America.
Description.
"Inoceramus cuvieri" are commonly found as brown shells, usually with some shine. Immature "I. cuvieri" are not as flat as other shells in the same rock, having a high hump for its umbo, and having much thinner growth lines. Immature thin shells appear as fragile as other bivalves found in the same rocks. Mature "I. cuvieri" are flat and can be around 1 meter in size, leaving much thicker shells.
Environment.
"Inoceramus cuvieri" lived in shallow, temperate, normal-salinity inland seaways where the bottom was calcareous mud, corresponding to the maximum depth and width of the Greenhorn sequence of the Western Interior Seaway. The depths of as much as were far enough from shore for clear water and slow sedimentation, and the bottom deep enough for rare wave action disturbance. Fragments of shells from large individuals are encrusted by "Ostrea congesta", two "Serpula" species, and other sessile animals, reflecting that the shells of large "Inoceramus" floating on the mud were commonly the only hard surfaces available for colonization.
Distribution.
"Inoceramus cuvieri" are found throughout both middle Turonian Europe and the middle Turonian Western Interior Seaway.
In the High Plains of North America, "I. cuvieri" is an index fossil of the chalky lower Carlile Shale and upper Greenhorn Limestone and the corresponding bedding of the Mancos Shale, and shells of juveniles are particularly common in the Fencepost limestone bed.


Palatomaxillary suture

The palatomaxillary suture is a suture separating the maxilla from the palatine bone.


Pheasant

Pheasants () are birds of several genera within the subfamily Phasianinae, of the family Phasianidae in the order Galliformes. Though they can be found world over in introduced (and captive) populations, the pheasant genera native range is restricted to Asia.
Pheasants are characterised by strong sexual dimorphism, males being highly decorated with bright colours and adornments such as wattles. Males are usually larger than females and have longer tails. Males play no part in rearing the young.
Pheasants eat mostly seeds, grains, roots, and berries, while in the summer they take advantage of insects, fresh green shoots, spiders, earthworms, and snails.
The best-known is the common pheasant, which is widespread throughout the world, in introduced feral populations and in farm operations. Various other pheasant species are popular in aviaries, such as the golden pheasant ("Chrysolophus pictus").
Etymology.
According to the "Oxford English Dictionary", the word "pheasant" ultimately comes from Phasis, the ancient name of what is now called the Rioni River in Georgia.
It passed from Greek to Latin to French (spelled with an initial "f") then to English, appearing for the first time in English around 1299.
Species in taxonomic order.
This list is ordered to show presumed relationships between species.
Previous classifications.
"Euplocamus" and "Gennceus" are older names more or less corresponding to the current "Lophura".
These old genera were used for:


Orzeliscus

Orzeliscus is a genus of tardigrades in the family Halechiniscidae. The genus was named and described by Eveline Du Bois-Reymond Marcus in 1952.
Species.
The genus includes two species:


Fibroblast

A fibroblast is a type of biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework (stroma) for animal tissues, and plays a critical role in wound healing. Fibroblasts are the most common cells of connective tissue in animals.
Structure.
Fibroblasts have a branched cytoplasm surrounding an elliptical, speckled nucleus having two or more nucleoli. Active fibroblasts can be recognized by their abundant rough endoplasmic reticulum. Inactive fibroblasts (called fibrocytes) are smaller, spindle-shaped, and have a reduced amount of rough endoplasmic reticulum. Although disjointed and scattered when they have to cover a large space, fibroblasts, when crowded, often locally align in parallel clusters.
Unlike the epithelial cells lining the body structures, fibroblasts do not form flat monolayers and are not restricted by a polarizing attachment to a basal lamina on one side, although they may contribute to basal lamina components in some situations (e.g. subepithelial myofibroblasts in intestine may secrete the α-2 chain-carrying component of the laminin, which is absent only in regions of follicle-associated epithelia which lack the myofibroblast lining). Fibroblasts can also migrate slowly over substratum as individual cells, again in contrast to epithelial cells. While epithelial cells form the lining of body structures, it is fibroblasts and related connective tissues which sculpt the "bulk" of an organism.
The life span of a fibroblast, as measured in chick embryos, is 57 ± 3 days.
Relationship with fibrocytes.
Fibroblasts and fibrocytes are two states of the same cells, the former being the activated state, the latter the less active state, concerned with maintenance and tissue metabolism. Currently, there is a tendency to call both forms fibroblasts. The suffix "-blast" is used in cellular biology to denote a stem cell or a cell in an activated state of metabolism.
Fibroblasts are morphologically heterogeneous with diverse appearances depending on their location and activity. Though morphologically inconspicuous, ectopically transplanted fibroblasts can often retain positional memory of the location and tissue context where they had previously resided, at least over a few generations. This remarkable behavior may lead to discomfort in the rare event that they stagnate there excessively.
Development.
The main function of fibroblasts is to maintain the structural integrity of connective tissues by continuously secreting precursors of the extracellular matrix. Fibroblasts secrete the precursors of all the components of the extracellular matrix, primarily the ground substance and a variety of fibers. The composition of the extracellular matrix determines the physical properties of connective tissues.
Like other cells of connective tissue, fibroblasts are derived from primitive mesenchyme. Thus they express the intermediate filament protein vimentin, a feature used as a marker to distinguish their mesodermal origin. However, this test is not specific as epithelial cells cultured in vitro on adherent substratum may also express vimentin after some time.
In certain situations, epithelial cells can give rise to fibroblasts, a process called epithelial-mesenchymal transition (EMT).
Conversely, fibroblasts in some situations may give rise to epithelia by undergoing a mesenchymal to epithelial transition (MET) and organizing into a condensed, polarized, laterally connected true epithelial sheet. This process is seen in many developmental situations (e.g. nephron and notocord development), as well as in wound healing and tumorigenesis.
Function.
Fibroblasts make collagen fibres, glycosaminoglycans, reticular and elastic fibers. Growing individuals' fibroblasts are dividing and are synthesizing ground substance. Tissue damage stimulates fibrocytes and induces the production of fibroblasts.
Inflammation.
Besides their commonly known role as structural components, fibroblasts play a critical role in an immune response to a tissue injury. They are early players in initiating inflammation in the presence of invading microorganisms. They induce chemokine synthesis through the presentation of receptors on their surface. Immune cells then respond and initiate a cascade of events to clear the invasive microorganisms. Receptors on the surface of fibroblasts also allow regulation of hematopoietic cells and provide a pathway for immune cells to regulate fibroblasts.
Tumour mediation.
Fibroblasts, like the tumor-associated host fibroblasts (TAF), play a crucial role in immune regulation through TAF-derived extracellular matrix (ECM) components and modulators. TAF are known to be significant in the inflammatory response as well as immune suppression in tumors. TAF-derived ECM components cause alterations in the ECM composition and initiate the ECM remodeling. The ECM remodeling is described as changes in the ECM as a result of enzyme activity which can lead to degradation of the ECM. Immune regulation of tumors is largely determined by the ECM remodeling because the ECM is responsible for regulating a variety of functions, such as proliferation, differentiation, and morphogenesis of vital organs. In many tumor types, especially those related to the epithelial cells, ECM remodeling is common. Examples of TAF-derived ECM components include Tenascin and Thrombospondin-1 (TSP-1), which can be found in sites of chronic inflammation and carcinomas, respectively.
Immune regulation of tumors can also occur through the TAF-derived modulators. Although these modulators may sound similar to the TAF-derived ECM components, they differ in the sense that they are responsible for the variation and turnover of the ECM. Cleaved ECM molecules can play a critical role in immune regulation. Proteases like matrix metalloproteineases (MMPs) and the uPA system are known to cleave the ECM. These proteases are derived from fibroblasts.
Secondary actions.
Mouse embryonic fibroblasts (MEFs) are often used as "feeder cells" in human embryonic stem cell research. However, many researchers are gradually phasing out MEFs in favor of culture media with precisely defined ingredients of exclusively human derivation. Further, the difficulty of exclusively using human derivation for media supplements is most often solved by use of "defined media" where the supplements are synthetic and achieve the primary goal of eliminating the chance of contamination from derivative sources.
In view of the clinical application of stem cell derived tissues, the use of human fibroblast as feeders has been studied. Whereas the fibroblasts are usually used to maintain pluripotency of the stem cells, they can also be used to facilitate development of the stem cells into specific type of cells such as cardiomyocytes.
Host immune response.
Fibroblasts from different anatomical sites in the body express many genes that code for immune mediators and proteins. These mediators of immune response enable the cellular communication with hematopoietic immune cells. The immune activity of non-hematopoietic cells, such as fibroblasts, is referred to as “structural immunity”. In order to facilitate a fast response to immunological challenges, fibroblasts encode crucial aspects of the structural cell immune response in the epigenome.


Urnaloricus

Urnaloricus is a genus of loriciferans, distinct enough to belong in its own family, Urnaloricidae. Adult specimens are unknown, and are not thought to form part of the animal's lifecycle.
Species include:


Prototrisauropodiscus

Prototrisauropodiscus is an ichnogenus of reptile footprint.


Ligiarctus

Ligiarctus is a genus of tardigrades, in the subfamily Florarctinae which is part of the family Halechiniscidae. The genus was named and described by Jeanne Renaud-Mornant in 1982.
Species.
The genus includes two species:


Cyrtopora

Cyrtopora is an extinct genus from a class of marine Bryozoans, the cyclostomes. It lived from 140 - 66 million years ago during the Cretaceous Period of Europe.


Endotenon


James Davidson (ornithologist)

James Davidson FZS (28 March 1849 – 25 June 1925) was a Scottish naturalist in colonial India. He studied birds and many aspects of Indian natural history during his career in the Indian Civil Service, mostly posted in the Bombay Presidency and central India.
Davidson was born at Maryhill near Glasgow to William James Davidson and Harriet, daughter of Mark Sprot. His early education was at St Andrews in the private school of Mr Douglas before he went to study followed by studies at Glasgow and Edinburgh Universities. He qualified in the Indian Civil Services in 1872 and served in the Bombay Presidency until 1897. For his work during the famine years around 1876–78, he received a special award from the government. He retired to Edinburgh, Scotland.
During his service in India, he wrote extensively about the birds of the regions of present-day Uttara Kannada, Satara and Belgaum, corresponding with Allan Octavian Hume, to whom he gave his bird collection. His method included the use of local lads (including the Bhils) who located bird nests for him. He wrote numerous notes to "Stray Feathers", the Journal started by Hume as well as to the journal of the Bombay Natural History Society. Just before his retirement, he made a trip to Kashmir with the lepidopterist and forest officer Thomas Reid Davys Bell. He was a member of the British Ornithologists' Union from 1883.


Diversity of fish

Fish are very diverse animals and can be categorised in many ways. This article is an overview of some of ways in which fish are categorised. Although most fish species have probably been discovered and described, about 250 new ones are still discovered every year. According to FishBase, 34,300 species of fish had been described as of September 2020. That is more than the combined total of all other vertebrate species: mammals, amphibians, reptiles and birds.
Fish species diversity is roughly divided equally between marine (oceanic) and freshwater ecosystems. Coral reefs in the Indo-Pacific constitute the centre of diversity for marine fishes, whereas continental freshwater fishes are most diverse in large river basins of tropical rainforests, especially the Amazon, Congo, and Mekong basins. More than 5,600 fish species inhabit Neotropical freshwaters alone, such that Neotropical fishes represent about 10% of all vertebrate species on the Earth. Exceptionally rich sites in the Amazon basin, such as Cantão State Park, can contain more freshwater fish species than occur in all of Europe.
By taxonomy.
Fish systematics is the formal description and organisation of fish taxa into systems. It is complex and still evolving. Controversies over "arcane, but important, details of classification are still quietly raging".
The term "fish" describes any non-tetrapod chordate, (i.e., an animal with a backbone), that has gills throughout life and has limbs, if any, in the shape of fins. Unlike groupings such as birds or mammals, fish are not a single clade but a paraphyletic collection of taxa, including jawless, cartilaginous and skeletal types.
Jawless fish.
Jawless fish were the earliest fish to evolve. There is current debate over whether these are really fish at all. They have no jaw, no scales, no paired fins, and no bony skeleton. Their skin is smooth and soft to the touch, and they are very flexible. Instead of a jaw, they possess an oral sucker. They use this to fasten onto other fish, and then use their rasp-like teeth to grind through their host's skin into the viscera. Jawless fish inhabit both fresh and salt water environments. Some are anadromous, moving between both fresh and salt water habitats.
Extant jawless fish are either lamprey or hagfish. Juvenile lamprey feed by sucking up mud containing micro-organisms and organic debris. The lamprey has well-developed eyes, while the hagfish has only primitive eyespots. The hagfish coats itself and carcasses it finds with noxious slime to deter predators, and periodically ties itself into a knot to scrape the slime off. It is the only invertebrate fish and the only animal which has a skull but no vertebral column. It has four hearts, two brains, and a paddle-like tail.
Cartilaginous fish.
Cartilaginous fish have a cartilaginous skeleton. However, their ancestors were bony animals, and were the first fish to develop paired fins. Cartilaginous fish don't have swim bladders. Their skin is covered in placoid scales (dermal denticles) that are as rough as sandpaper. Because cartilaginous fish do not have bone marrow, the spleen and special tissue around the gonads produces red blood cells. Their tails can be asymmetric, with the upper lobe longer than the lower lobe. Some cartilaginous fishes possess an organ called a Leydig's organ which also produces red blood cells.
There are over 980 species of cartilaginous fish. They include sharks, rays and chimaera.
Bony fish.
Bony fish include the lobe-finned fish and the ray finned fish. The lobe-finned fish is the class of fleshy finned fishes, consisting of lungfish and coelacanths. They are bony fish with fleshy, lobed paired fins, which are joined to the body by a single bone. These fins evolved into the legs of the first tetrapod land vertebrates, amphibians. Ray finned fishes are so-called because they possess lepidotrichia or "fin rays", their fins being webs of skin supported by bony or horny spines ("rays").
There are three types of ray finned fishes: the chondrosteans, holosteans, and teleosts. The chondrosteans and holosteans are among the earlier fish to evolve, and share characteristics with both teleosts and sharks. In comparison with the other chondrosteans, the holosteans are closer to the teleosts and further from sharks.
Teleosts.
Teleosts are the most advanced or "modern" fishes. They are overwhelmingly the dominant class of fishes (or for that matter, vertebrates) with nearly 30,000 species, covering about 96 percent of all extant fish species. They are ubiquitous throughout fresh water and marine environments from the deep sea to the highest mountain streams. Included are nearly all the important commercial and recreational fishes.
Teleosts have a movable maxilla and premaxilla and corresponding modifications in the jaw musculature. These modifications make it possible for teleosts to protrude their jaws outwards from the mouth. The caudal fin is homocercal, meaning the upper and lower lobes are about equal in size. The spine ends at the caudal peduncle, distinguishing this group from those in which the spine extends into the upper lobe of the caudal fin.
By life span.
Some of the shortest-lived species are gobies, which are small coral reef–dwelling fish. Some of the longest-lived are rockfish.
By shape.
Boxfishes have heavily armoured plate-like scales fused into a solid, triangular, boxlike carapace, from which the fins, tail, eyes and mouth protrude. Because of this heavy armour, boxfish move slowly, but few other fish are able to eat the adults.


Franz Hermann Troschel

Franz Hermann Troschel (10 October 1810 – 6 November 1882) was a German zoologist born in Spandau.
He studied mathematics and natural history at the University of Berlin, where he was awarded his doctorate in 1834. From 1840 to 1849 he was an assistant to Martin Lichtenstein at the Natural History Museum of Berlin. In 1849 he became a professor of zoology and natural history at the University of Bonn. In 1851 he became a member of the Academy of Sciences Leopoldina.
Troschel is remembered for the identification and classification of species in the fields of malacology, ichthyology and herpetology. A few of the species that contain his name are Troschel's sea star ("Evasterias troschelii)", Troschel's parrotfish ("Chlorurus troschelii)", Troschel's murex ("Murex troschelii)", and a freshwater snail ("Bithynia troschelii)".


Parachela (tardigrade)

Parachaela is an order of tardigrade in the class Eutardigrada.


Elaphoidella jeanneli

Elaphoidella jeanneli is a species of harpacticoid copepod in the family Canthocamptidae. It is found in Europe.
The IUCN conservation status of "Elaphoidella jeanneli" is "VU", vulnerable. The species faces a high risk of endangerment in the medium term. The IUCN status was reviewed in 1996.


Hugh Whistler

Hugh Whistler (28 September 1889 – 7 July 1943), F.Z.S., M.B.O.U. was an English police officer and ornithologist who worked in India. He wrote one of the first field guides to Indian birds and documented the distributions of birds in notes in several journals apart from describing new subspecies.
Life and career.
Hugh was the first son of Major Fuller Whistler of the Highland Light Infantry and Gwenllian Annie (née Robinson) and was born at Mablethorpe in 1889. Whistler was educated at Aldenham School. His younger brother Ralfe Allen Fuller Whistler (24 July 1895 - 28 April 1917) followed after his father and joined the Highland Light Infantry while Hugh went to serve with the Indian police mainly in the Punjab.
He served in India from December 1909 to April 1926. He was initially posted at Phillaur but was later to serve across Punjab including districts such as Jhang that were considered unpopular. He was posted in other regions including Kangra, Lahul and Spiti. He began to correspond with Claud Buchanan Ticehurst and, when on leave in England in 1910, he visited Grove House at Lowestoft and was introduced to scientific ornithology. Wherever he was posted, he took an interest in the local birdlife, keeping careful notes and making collections. In 1924 he returned to England and made a trip to Spain with Ticehurst.
On 2 October 1925 Whistler married Margaret Joan Ashton (1893–1981) daughter of Thomas Gair Ashton, 1st Baron Ashton of Hyde and Eva Margaret James who were from near his own home in Battle. He died on 7 July 1943 leaving behind a daughter Benedicta (now deceased) and son Ralfe.
Ornithology.
Whistler studied and collected birds wherever he was posted in India. On retiring to England he continued his research into Indian ornithology. He published extensively in the "Journal of the Bombay Natural History Society", making notes on the occurrence and on the distributions of geographic plumage variations. He published a ten-part introduction to the study of birds in India. He made collecting trips to Spain, Albania, Italy and Algeria often in the company of Claud Buchanan Ticehurst.
Around 1925 a plan was made by W S Millard, Sir George Lowndes and F J Mitchell to produce an illustrated guide to the birds of India for beginners. Whistler was asked to help in its writing. It was eventually published in 1928 as the "Popular Handbook of Indian Birds". Four later editions of this publication were issued, and the last was published after his death. In this work he foresaw the value of popularizing observation-based ornithology:
Whistler lived at Battle, East Sussex during his retirement, where he was a Justice of the Peace. He made one trip to India in 1928 as a guest of Admiral Hubert Lynes with the intention of studying the birds of Kashmir. Lynes was recalled to England and insisted that Whistler and Bertram Beresford Osmaston complete the bird survey. He joined the British Ornithologists' Union in 1913 and in 1940 served as its as vice-president. He visited Kashmir with Admiral Lynes and wanted to produce an account of the birds of Punjab and Kashmir; this was not completed.
He was also interested in hounds, pheasant rearing, falconry and was an antiquarian. He was for a while involved in the care of Bodiam Castle. Whistler was a very careful and critical observer noted for his "capacity for taking pains".
He was skeptical of George Bristow and his observations which was later to become famous as the Hastings Rarities scandal. Whistler was critical of egg collection driven by trade and remarked on the unscrupulous collection that he heard of from a correspondent in the Khasi hills. He further remarked that eggs from Assam or Sikkim be treated with caution by oologists. This article was reacted to by E C Stuart Baker.
Several subspecies of birds were named after him including some by Ticehurst, Delacour and Stresemann. Whistler's warbler originally described as "Seicercus burkii whistleri" is now considered a full species: "Seicercus whistleri". The Whistler Prize of Sussex University, awarded to the best essay on natural history or archaeology, is named after him. His collection of 17,320 bird skins was presented to the Natural History Museum by Mrs Whistler in 1949.
Writings.
A partial list of Whistler's writings includes:


Olenoidestranans

Olenoidestranans is an extinct genus from a well-known class of fossil marine arthropods, the trilobites. It lived from 501 to 490 million years ago during the Dresbachian faunal stage of the late Cambrian Period.


Arcuate foramen

In human anatomy, arcuate foramen, also known as ponticulus posticus (Latin for "little posterior bridge") or Kimmerle's anomaly, refers to a bony bridge on the atlas (C1 vertebra) that covers the groove for the vertebral artery. It is a common anatomical variation and estimated to occur in approximately 3-15% of the population. It occurs in females more commonly than males. The ponticulus posticus is created through ossification of the posterior atlantooccipital ligament.
Pathology.
The presence of arcuate foramen is associated with headache, musculoskeletal pain and vertebrobasilar stroke.


New World sparrow

New World sparrows are a group of mainly New World passerine birds, forming the family Passerellidae. They are seed-eating birds with conical bills, brown or gray in color, and many species have distinctive head patterns.
Although they share the name sparrow, New World sparrows are more closely related to Old World buntings than they are to the Old World sparrows (family Passeridae). New World sparrows are also similar in both appearance and habit to finches, with which they sometimes used to be classified.
Taxonomy.
The genera now assigned to the family Passerellidae were previously included with the buntings in the family Emberizidae. A phylogenetic analysis of nuclear and mitochondrial DNA sequences published in 2015 found that the Passerellidae formed a monophyletic group that had an uncertain relationship to the Emberizidae. Emberizidae was therefore split and the family Passerellidae resurrected. It had originally been introduced, as the subfamily Passerellinae, by the German ornithologist Jean Cabanis in 1851.
The International Ornithological Congress (IOC) recognizes these 138 species in the family, distributed among 29 genera in the following sequence. One extinct species, the Bermuda towhee, is included. The North American and South American classification committees of the American Ornithological Society (AOS) do not recognize all of these species and use some different common names.
Genus "Oreothraupis"
Genus "Chlorospingus"
Genus "Rhynchospiza"
Genus "Peucaea"
Genus "Ammodramus"
Genus "Arremonops"
Genus "Amphispiza"
Genus "Chondestes"
Genus "Calamospiza"
Genus "Spizella"
Genus "Arremon"
Genus "Passerella"
Genus "Spizelloides"
Genus "Junco"
Genus "Zonotrichia"
Genus "Artemisiospiza"
Genus "Oriturus"
Genus "Pooecetes"
Genus "Ammospiza"
Genus "Centronyx"
Genus "Passerculus"
Genus "Xenospiza"
Genus "Melospiza"
Genus "Pezopetes"
Genus "Torreornis"
Genus "Melozone"
Genus "Aimophila"
Genus "Pipilo"
Genus "Atlapetes"


Orchesella multifasciata

Orchesella multifasciata is a species of slender springtail in the family Entomobryidae.


George William Chaster

George William Chaster (1863 – 5 May 1910) was an English doctor, entomologist, and conchologist.
Life.
George William Chaster was born in Wigan in 1863. He trained as a doctor at University College, Liverpool, winning the Lyon-Jones Scholarship in 1882 and was appointed the Holt Tutorial Fellow in 1889. He also won a number of medals during his training. He established his medical practice in Southport. He was one of the founding members of the Southport Natural Science Society and served as the editor of the Society's journal.
From a young age, Chaster was interested in the natural sciences, in particular conchology. He spent is holidays in Ireland, where he would dredge and collect specimens. Along with Irish naturalists, including Robert Welch, Chaster dredged around Rathlin Ireland in 1896 and 1897. He also took part in the Royal Irish Academy's Clare Island Survey. He was also interested in Foraminifera and Coleoptera, publishing numerous papers on a variety of topics. As well as collecting locally in Southport, he also collected in Nottinghamshire. In Ireland, he added a number of newly recorded species to lists. Chaster named the mollusc species, "Arculus sykesii" and "Neolepton obliquatum", the genus "Retrotortina" with the monotypic species "R. fuscata" which is considered as Europe's smallest gastropod, and the genus "Cima". The foraminifer species "Rotalliella chasteri" described by Edward Heron-Allen and Arthur Earland in 1913 under the genus "Discorbina" is named after him. He served as the vice-president of the Conchological Society of Great Britain & Ireland.
Chaster died on 5 May 1910 from pleuro-pneumonia. The National Museum of Wales holds his collection of around 11,000 insects, and 2,890 lots of molluscs. Robert Lloyd Praeger stated that "Irish conchology especially owes much to his work" and that his premature death "was a severe loss to Irish zoology". Obituaries were published in the "British Medical Journal" and "The Entomologist's Monthly Magazine".


Splanchnic

Splanchnic is usually used to describe organs in the abdominal cavity.
It is used when describing:
History and etymology.
The term derives from , meaning "inward parts, organs".
The term "splanchnologia" is used for grouping in "Nomina Anatomica", but not in "Terminologia Anatomica". It includes most of the structures usually considered "internal organs", but not all (for example, the heart is excluded).


William Henry Kelson

William Henry Kelson FRCS FZS (15 August 1862 – 24 January 1940) was an English physician and writer, President of the Hunterian Society, Fellow of the Royal College of Surgeons and of the Zoological Society of London.
Early life.
Kelson was born in London. He was educated at Gresham's School, Holt, and from 1880 at the London Hospital (now the Royal London Hospital, where he held the Letheby scholarship.
Career.
After qualifying as a surgeon, Kelson held various hospital appointments. He was surgeon to the throat and ear department of the City Dispensary, became President of the Laryngological Section and Honorary Secretary to the Otological and Laryngological Sections of the Royal Society of Medicine and President of the Hunterian Society.
Family.
In 1921, Kelson married Hilda Frances, younger daughter of Arthur W. Lane, of Ealing, but they had no children. He was the only son or William Henry Kelson Snr and Ann Maria Perry. He had two sisters, Emily and Wilhelmina. He was the grandson of Colonel Charles Kelson and great-grandson of Dr Thomas Mortimer Kelson of Sevenoaks in Kent.


Geodia hentscheli

Geodia hentscheli is a species of sponge in the family Geodiidae. It is found in the waters of the North Atlantic Ocean. The species was described in 2010 by Paco Cárdenas, Hans Tore Rapp, Christoffer Schander & Ole S. Tendal.


Reticular connective tissue

Reticular connective tissue is a type of connective tissue with a network of reticular fibers, made of type III collagen ("reticulum" = net or network). Reticular fibers are not unique to reticular connective tissue, but only in this type they are dominant.
Reticular fibers are synthesized by special fibroblasts called reticular cells. The fibers are thin branching structures.
Location.
Reticular connective tissue is found around the kidney, liver, the spleen, and lymph nodes, Peyer' patches as well as in bone marrow.
Function.
The fibers form a soft skeleton (stroma) to support the lymphoid organs (lymph node stromal cells, red bone marrow, and spleen).
Adipose tissue is held together by reticular fibers.
Staining.
They can be identified in histology by staining with a heavy metal like silver or the PAS stain that stains carbohydrates.
Gordon and Gold can also be used.
Appearance.
Reticular connective tissue resembles areolar connective tissue, but the only fibers in its matrix are reticular fibers, which form a delicate network along which fibroblasts called reticular cells lie scattered. Although reticular fibers are widely distributed in the body, reticular tissue is limited to certain sites. It forms a labyrinth-like stroma (literally, "bed or "mattress"), or internal framework, that can support many free blood cells (largely lymphocytes) in lymph nodes, the spleen, and red bone marrow.
Classification.
There are more than 20 types of reticular fibers. In Reticular Connective Tissue type III collagen/reticular fiber (100-150 nm in diameter) is the major fiber component. It forms the architectural framework of liver, adipose tissue, bone marrow, spleen and basement membrane, to name a few.
References.
Notes


Deep cervical vein

The deep cervical vein (posterior vertebral or posterior deep cervical vein) accompanies its artery between the Semispinales capitis and colli.
It begins in the suboccipital region by communicating branches from the occipital vein and by small veins from the deep muscles at the back of the neck.
It receives tributaries from the plexuses around the spinous processes of the cervical vertebræ, and terminates in the lower part of the vertebral vein.


Retrocalcaneal bursitis

Retrocalcaneal bursitis is an inflammation of the bursa located between the calcaneus and the anterior surface of the Achilles tendon. It commonly occurs in association with rheumatoid arthritis, spondyloarthropathies, gout, and trauma.
The pain is usually on the back of the heel and swelling appears on lateral or medial side of the tendon.


Interlobar veins

The interlobar veins are veins of the renal circulation which drain the renal lobes.


Martin Rathke

Martin Heinrich Rathke (August 25, 1793, Danzig – September 3, 1860, Königsberg) was a German embryologist and anatomist. Along with Karl Ernst von Baer and Christian Heinrich Pander, he is recognized as one of the founders of modern embryology. He was the father of chemist Bernhard Rathke (1840–1923).
He studied medicine and natural history at the University of Göttingen, later relocating to Berlin, where he received his doctorate in medicine (1818). In 1828 he was named professor of physiology, pathology and semiotics at the University of Dorpat. In 1832/33 he undertook research expeditions to Finland and to the Crimea. Rathke was a professor of zoology and anatomy at Königsberg from 1835 to 1860. In 1839, while based in Königsberg, he travelled to Scandinavia, where he conducted studies of marine organisms.
He studied marine organisms and the embryonic development of sex organs. He was the first to describe the brachial clefts and gill arches in the embryos of mammals and birds. He also first described in 1839 the embryonic structure, now known as Rathke's pouch, from which the anterior lobe of the pituitary gland develops.
He was the first to discover that the amphioxus was a separate taxa, and not the larvae of a mollusk, as previously thought. He was the author of several writings on crustaceans, mollusks and worms, and also the author of works on vertebrates, such as the lemming and various reptiles.


Henderson crake

The Henderson crake or red-eyed crake ("Zapornia atra") is a species of flightless bird in the family Rallidae. It is endemic to Henderson Island in the southeast Pacific Ocean. Its natural habitat is subtropical or tropical moist lowland forest.
The population of this species is estimated to be 6,200 mature individuals, roughly equivalent to 9,300 individuals in total.
Habitat and ecology.
The species is found in dense to open forest throughout the island plateau, both in forest dominated by "Pisonia" and "Pisonia"/"Xylosma", and in "Timonius" thicket, also occurring in "Pandanus"-"Thespesia"-"Argusia" embayment forests and coconut groves on the beaches (Jones et al. 1995). It is omnivorous and appears to be an opportunistic feeder, taking advantage of seasonal increases in prey (Jones et al. 1995). It forages in the leaf-litter, gleaning items such as skink "Emoia cyanura" eggs from the undersides of fallen leaves, large nematodes, beetles, moths, spiders, dead caterpillars, land snails and small insects (Jones et al. 1995). The breeding season is long, extending from late July to mid February (double broods are not uncommon) and clutch-size is 2-3 (Jones et al. 1995). Helpers may provide extraparental care such as defending eggs and chicks from crabs and rats. Based on a small sample, adult annual survival is at least 43%, and reproductive success is a minimum of 0.95 chicks surviving to one month old per pair, per annum (Jones et al. 1995).


Florence Wambugu

Florence Muringi Wambugu (born 23 August 1953) is a Kenyan plant pathologist and virologist. She is known for her advocacy of using biotechnology to increase food production in Africa.
Education.
She attended the University of Nairobi, Kenya, where she received her Bachelor of Science in botany and zoology. She obtained her Master of Science in botanical pathology from North Dakota State University, United States in 1984; and her PhD from the University of Bath, England in 1991.
She was also awarded an Honorary Degree (Doctor of Science) from the University of Bath in 2009.
Professional career.
Wambugu is the founder, director and the chief executive officer of Africa Harvest Biotech Foundation International (AHBFI) since 1994. AHBFI is a nonprofit foundation with offices in Nairobi, Kenya, Johannesburg, South Africa, and Washington, D.C. Previously, she founded, established and worked as Africa Region Director, ISAAA – Afri-center, in Nairobi. From 1978 to 1991, she worked as a senior research officer (pathologist) and coordinator of plant biotechnology research at the Kenya Agricultural Research Institute (KARI), Kenya. Thereafter (1991–1994), she was a post-doctoral fellow with Monsanto Company.
She has made significant contributions to the research, development and improvement of maize, pyrethrum, banana, sweet potato and forestry production in Kenya. She has published over 100 articles and co-authored various papers.
Previously, she served on several board of directors including the Private Sector Committee of the CGIAR, the United Nations Millennium Development goals Hunger task force; she also was a member of the Executive Committee of Forum for Agricultural Research in Africa (FARA); the DuPont Company Biotech Advisory Panel, USA; the International Plant Genetic Resources Institute (IPGRI, now called Bioversity International), and the African Biotechnology Stakeholders Forum (ABSF).
Currently, she is serving as a Council Member of the Japan ; a steering committee member of the European Action on Global Life Sciences (EAGLES); and a Science Board member of the Bill and Melinda Gates Foundation Grand Challenge in Global Health.
GM Sweet Potato.
Florence Wambugu was involved in a project to develop a genetically modified (GM) sweet potato. In February 2004, the science magazine, New Scientist, reported that the project had failed.
Awards.
Florence Wambugu has been the recipient of numerous awards.
Personal life.
Florence Wambugu has three children.


Niven Busch

Niven Busch (April 26, 1903 – August 25, 1991) was an American novelist and screenwriter of movies such as the acclaimed "The Postman Always Rings Twice". His novels included "Duel in the Sun" (1944) and "California Street". He was married to actress Teresa Wright for ten years beginning in 1942.
Early career.
Born in New York City, Busch began his writing career in the early twenties, when he went to work for "Time" Magazine (co-founded by Busch's cousin, Briton Hadden). Before departing for Hollywood a decade later, Busch had risen to editor at the weekly, working simultaneously for "The New Yorker", where he contributed profiles on famous Americans. (These articles were collected into his first book, the non-fiction "Twenty-One Americans".)
In 1932, realizing he had gone as far as he was likely to go as a New York-based magazine writer/editor, Busch re-connected with agent Myron Selznick, whom Busch knew through his father, an executive who had worked for Myron's father Lewis in the teens and early twenties.
Myron Selznick soon secured work for Busch at Warner Bros. Pictures, and Busch decamped to Los Angeles to write his first film, Howard Hawks's "The Crowd Roars". One of four writers on the production, Busch's name was misspelled in the credits.
Film career.
Through the rest of the thirties, Busch worked for most of the major Hollywood studios, scripting mostly B-movies like "The Big Shakedown". In 1938 he was nominated for an Academy Award for "In Old Chicago", which was based on his story "We the O'Learys", but failed to win. In 1940 he co-wrote "The Westerner" for director William Wyler and producer Samuel Goldwyn. Soon thereafter he went to work as Goldwyn's story editor, recommending "Pride of the Yankees", in which Gary Cooper and Busch's soon-to-be wife Teresa Wright co-starred.
Settling in the hills of Encino with his growing family, Busch began writing novels. "The Carrington Incident", published in 1941, was followed by the best-seller "Duel in the Sun", which Lewis Selznick's other son David purchased and turned into the 1946 blockbuster of the same title. He now alternated between the writing of screenplays and novels, most of which became best-sellers. "They Dream of Home", a tale of returning veterans, was followed by "The Furies" (1950), which became a film that starred Barbara Stanwyck.
Another notable film of the period — for which Busch wrote the original screenplay — was "Pursued" starring Robert Mitchum and Teresa Wright, one of the first psychological Westerns with "noir" overtones. Around the same time, Busch also adapted the noir thriller "The Postman Always Rings Twice" (1946), for Metro-Goldwyn-Mayer.
Later career.
In the early fifties, Busch and Wright divorced, and Busch left Hollywood for northern California, where he devoted himself to cattle ranching and the full-time writing of novels. There he would meet his fourth wife Carmencita Baker and fifth wife Suzanne de Sanz.
Before Busch's final novel "The Titan Game" he had become one of San Francisco's leading literary lights and a Regent's Professor at the University of California. "California Street" is about the San Francisco newspaper publishing business, with the title taken from California Street in the city.
Busch appears in the film "The Unbearable Lightness of Being", playing the role of "Old Man" in the scene in which Sabina (Lena Olin) receives the letter informing her of Tómas and Tereza's deaths. Busch was 84 at the time of the filming.
Busch died from congestive heart failure in 1991 at the age of eighty-eight.


Lacrimal artery

The lacrimal artery is an artery that arises close to the optic foramen, and is one of the largest branches derived from the ophthalmic artery. Not infrequently it is given off before the artery enters the orbit.
It accompanies the lacrimal nerve along the upper border of the lateral rectus and supplies the lacrimal gland.
Branches.
Its terminal branches, escaping from the gland, are distributed to the eyelids and conjunctiva: of those supplying the eyelids, two are of considerable size and are named the lateral palpebral arteries; they run medially in the upper and lower lids respectively and anastomose with the medial palpebral arteries, forming an arterial circle in this situation.
The lacrimal artery also give off one or two zygomatic branches, one of which passes through the zygomatico-temporal foramen, to reach the temporal fossa, and anastomoses with the deep temporal arteries; another appears on the cheek through the zygomatico-facial foramen, and anastomoses with the transverse facial.
A recurrent branch passes backward through the lateral part of the superior orbital fissure to the dura mater, and anastomoses with a branch of the middle meningeal artery.
Variations.
The lacrimal artery is sometimes derived from one of the anterior branches of the middle meningeal artery.


Ludwig Karl Georg Pfeiffer

Ludwig Karl Georg Pfeiffer, also known as Louis Pfeiffer (4 July 1805 – 2 October 1877), was a German physician, botanist and conchologist.
Biography.
He received his education in Kassel, and became professor of pathology there in 1828. He served as surgeon-major in Kracow during the Polish rebellion of 1831, traveled afterward through Europe for the interest of science, and was given in 1839 by the Bavarian government a mission to study the natural history of the West Indies. He remained for more than two years in Cuba, then visited most of the West Indian islands. On his return to Europe, he published "Monographia Heliceorum viventium" (4 vols., Leipzig, 1847–48; supplement, 1853); "Symbola ad historiam heliceorum" (3 vols., Cassel, 1851–56); and other works.
Animals named by Pfeiffer.
He named more than 20 new genera and species, some of which have become synonyms:
Marine life named after Pfeiffer.
In the course of time, 24 marine species have been named after Pfeiffer with the epithets "pfeifferi", "pfeifferae", "pfeifferianus" and "pfeifferianum", many of which have become synonyms:
Bibliography.
Partial list of publications:


Pambdelurion

Pambdelurion whittingtoni is an extinct, nektonic organism from the Sirius Passet Lagerstätte, from Cambrian Greenland. Its anatomy strongly suggests that it, along with its relative "Kerygmachela kierkegaardi", was either an anomalocarid or a close relative thereof.
"P. whittingtoni" had a pair of massive anterior limbs that corresponded to the feeding limbs of other anomalocarids. The anterior limbs had a row of flexible, hair-like spines that corresponded with each segment of each limb. Unlike "K. kierkegaardi", "P. whittingtoni"'s mouth was relatively large, though it does not appear to have any large biting surfaces like the mouth of "Anomalocaris". It had 11 pairs of lateral lobes, and 11 pairs of relatively large, lobopod-like legs. None of the fossil specimens have any suggestion of posterior cerci, or tail-flaps.
The massive anterior limbs, with their comb-like rows of spines, suggest that "P. whittingtoni" was a planktivore.


Frederic Moore

Frederic Moore FZS (13 May 1830 – 10 May 1907) was a British entomologist. He was also an illustrator and produced six volumes of "Lepidoptera Indica" and a catalogue of the birds in the collection of the East India Company.
It has been said that Moore was born at 33 Bruton Street, but that may be incorrect given that this was the address of the menagerie and office of the Zoological Society of London from 1826 to 1836. Moore was appointed an assistant in the East India Company Museum London from 31 May 1848 on a "disestablished basis" and became a temporary writer and then an assistant curator at the East India Museum with a pension of £330 per annum from 31 December 1879. He had a daughter Rosa Martha Moore. He began compiling "Lepidoptera indica" (1890–1913), a major work on the butterflies of the South Asia in 10 volumes, which was completed after his death by Charles Swinhoe. Many of the plates were produced by his son while some others were produced by E C Knight and John Nugent Fitch. Many species of butterfly were described by him in this work.
"Moore entered the doors of entomology by way of his artistic abilities. Dr. T. Horsfield (1777–1859), long associated with the East India Museum, required someone capable of doing natural history drawings and, through an introduction, Frederic Moore obtained the post. Thus began a lifetime association with Indian Lepidoptera"
Moore's son F. C. Moore was also an artist and prepared many of the plates in "Lepidoptera Indica". Moore's brother T. J. Moore was a curator at the Liverpool Museum for forty years and his son Thomas Francis Moore was an osteologist at the National Museum at Melbourne.
Moore was an associate of the Linnean Society of London, a member of the Entomological Society of London, a corresponding member of the Entomological Society of Stettin and of the Entomological Society of the Netherlands. His other works included "A Catalogue of the Birds in the Museum of the East-India Company" (1854–58, with Thomas Horsfield) and "The Lepidoptera of Ceylon" (1880–87).


Loop of Henle

In the kidney, the loop of Henle () (or Henle's loop, Henle loop, nephron loop or its Latin counterpart ansa nephroni) is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. Named after its discoverer, the German anatomist Friedrich Gustav Jakob Henle, the loop of Henle's main function is to create a concentration gradient in the medulla of the kidney.
By means of a countercurrent multiplier system, which uses electrolyte pumps, the loop of Henle creates an area of high urea concentration deep in the medulla, near the papillary duct in the collecting duct system. Water present in the filtrate in the papillary duct flows through aquaporin channels out of the duct, moving passively down its concentration gradient. This process reabsorbs water and creates a concentrated urine for excretion.
Structure.
The loop of Henle can be divided into four parts:
The tissue type of the loop is simple squamous epithelium. The "thick" and "thin" terminology does not refer to the size of the lumen, but to the size of the epithelial cells. The loop is also sometimes called the Nephron loop.
Blood supply.
The loop of Henle is supplied by blood in a series of straight capillaries descending from the cortical efferent arterioles. These capillaries (called the vasa recta; "recta" is from the Latin for "straight") also have a countercurrent multiplier mechanism that prevents washout of solutes from the medulla, thereby maintaining the medullary concentration. As water is osmotically driven from the descending limb into the interstitium, it readily enters the capillaries. The low bloodflow through the vasa recta allows time for osmotic equilibration, and can be altered by changing the resistance of the vessels' efferent arterioles.
As well, blood in the vasa recta still has large proteins and ions which were not filtered through the glomerulus. This provides an oncotic pressure for ions to enter the vasa recta from the interstitium.
The main function of the loop of Henle is to set up a concentration gradient.
Physiology.
The descending loop of Henle receives isotonic (300 mOsm/L) fluid from the proximal convoluted tubule (PCT). The fluid is isotonic because as ions are reabsorbed by the gradient time system, water is also reabsorbed maintaining the osmolarity of the fluid in the PCT. Substances reabsorbed in the PCT include urea, water, potassium, sodium, chloride, glucose, amino acids, lactate, phosphate, and bicarbonate. Since water is also reabsorbed the volume of fluid in the loop of Henle is less than the PCT, approximately one-third of the original volume.
The interstitium of the kidney increases in osmolarity outside as the loop of Henle descends from 600 mOsm/L in the outer medulla of the kidney to 1200 mOsm/L in the inner medulla. The descending portion of the loop of Henle is extremely permeable to water and is less permeable to ions, therefore water is easily reabsorbed here and solutes are not readily reabsorbed. The 300 mOsm/L fluid from the loop loses water to the higher concentration outside the loop and increases in tonicity until it reaches its maximum at the bottom of the loop. This area represents the highest concentration in the nephron, but the collecting duct can reach this same tonicity with maximum ADH effect.
The ascending limb of the loop of Henle receives an even lower volume of fluid and has different characteristics compared to the descending limb. In the ascending portion, the loop becomes impermeable to water and the cells of the loop actively reabsorb solutes from the luminal fluid; therefore water is not reabsorbed and ions are readily reabsorbed. As ions leave the lumen via the Na-K-2Cl symporter and the Na-H antiporter, the concentration becomes more and more hypotonic until it reaches approximately 100-150 mOsm/L. The ascending limb is also called the diluting segment of the nephron because of its ability to dilute the fluid in the loop from 1200 mOsm/L to 100 mOsm/L.
Flow of the fluid through the entire loop of Henle is considered slow. As flow increases, the ability of the loop to maintain its osmolar gradient is reduced. The vasa recta (capillary loops) also have a slow flow as well. Increases in vasa recta flow wash away metabolites and cause the medulla to lose osmolarity as well. Increases in flow will disrupt the kidney's ability to form concentrated urine.
Overall the loop of Henle reabsorbs around 25% of filtered ions and 20% of the filtered water in a normal kidney. These ions are mostly Na+, Cl−, K+, Ca2+ and HCO3−. The powering force is the Na/K ATPase on the basolateral membrane which maintains the ion concentrations inside the cells. On the luminal membrane, Na enters the cells passively; using the Na-K-2Cl symporter. Then the Na/K ATPase will pump 3 Na out into the peritubular fluid and 2 K into the cell on the non-lumen side of the cell. This gives the lumen of the fluid in the loop a positive charge in comparison and creates a Na concentration gradient, which both push more Na into the cell via the Na-H antiporter. The hydrogen ion for the antiporter comes from the enzyme carbonic anhydrase, which takes water and carbon dioxide and forms bicarbonate and a hydrogen ion. The hydrogen ion is exchanged for the Na in the tubular fluid of the loop of Henle.