title: "Scottish National Gallery" content: "Diana and Actaeon" and "Diana and Callisto" (purchased jointly with the National Gallery, London). The Scottish National Gallery has also jointly acquired one of Canova's sculptures of The Three Graces with the Victoria and Albert Museum. The Scottish National Gallery has a notable collection of works by Scottish artists, including several landscapes by Alexander Nasmyth, and several works by Sir Henry Raeburn — of particular note his portraits of Alexander Ranaldson Macdonell and Sir Walter Scott), and his celebrated painting, "The Skating Minister". There are also a number of works by artists of the Glasgow School such as James Guthrie.


title: "Scottish National Gallery" content: The Gallery also holds a collection of works by English painters, such as Constable's "Dedham Vale" and a sizeable collection of water colours by Turner which are traditionally displayed in January. "The Monarch of the Glen", a painting considered to be iconic of Scottish culture, is also held in the gallery, the work of the English painter Landseer. Key works of art displayed at the National Gallery include: Other artists represented in the collection include: Scottish National Gallery The Scottish National Gallery (formerly the National Gallery of Scotland) is the national art gallery of Scotland. It is located on The


title: "Blake's 7" content: who take him outside the city to meet their leader, Bran Foster. According to Foster, Blake was once the leader of an influential group of political activists opposed to the Federation's Earth Administration. Blake was arrested, brainwashed and coerced into making a confession denouncing the rebellion. His memory of those years was then blocked. Foster wants Blake to rejoin the dissidents. Suddenly, the meeting is interrupted by the arrival of Federation security forces, who shoot and kill the crowd of rebels. Blake, the only survivor, returns to the city, where he begins to remember his past. He is arrested, tried


title: "Eric Bloodaxe" content: stanza which is usually assigned to Þorbjörn Hornklofi's "Hrafnsmál", a eulogy on Harald's deeds in the form of a conversation between a raven and valkyrie. It tells that Harald "chose the lady from Denmark ["konu danska"] / broke with his Rogaland loves / and his lemans of Horthaland, / the maidens of Hálogaland / and of Hathaland eke." In the "Flateyjarbók", it is preceded by another stanza which refers to the "handmaidens of Ragnhildr" ("ambáttir Ragnhildar") as witnesses of the event. However, it is uncertain whether her name was already in the original composition, as another manuscript reading has the


title: "Sea urchin" content: Sea urchin Sea urchins or urchins () are typically spiny, globular animals, echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal to . Their tests (hard shells) are round and spiny, typically from across. Sea urchins move slowly, crawling with their tube feet, and sometimes pushing themselves with their spines. They feed primarily on algae but also eat slow-moving or sessile animals. Their predators include sea otters, starfish, wolf eels, and triggerfish. Like other echinoderms, urchins have fivefold symmetry as adults, but their pluteus larvae have bilateral (mirror)


title: "Sea urchin" content: symmetry, indicating that they belong to the Bilateria, the large group of animal phyla that includes chordates, arthropods, annelids and molluscs. They are widely distributed across all the oceans, all climates from tropical to polar, and inhabit marine benthic (sea bed) habitats from rocky shores to hadal zone depths. Echinoids have a rich fossil record dating back to the Ordovician, some 450 million years ago. Their closest relatives among the echinoderms are the sea cucumbers (Holothuroidea); both are deuterostomes, a clade which includes the chordates. The animals have been studied since the 19th century as model organisms in developmental biology,


title: "Sea urchin" content: as their embryos were easy to observe; this has continued with studies of their genomes because of their unusual fivefold symmetry and relationship to chordates. Species such as the slate pencil urchin are popular in aquariums, where they are useful for controlling algae. Fossil urchins have been used as protective amulets. Sea urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The symmetry is not obvious in the living animal,


title: "Sea urchin" content: but is easily visible in the dried test. Specifically, the term "sea urchin" refers to the "regular echinoids", which are symmetrical and globular, and includes several different taxonomic groups, with two subclasses : Euechinoidea ("modern" sea urchins, including irregular ones) and Cidaroidea or "slate-pencil urchins", which have very thick, blunt spines, with algae and sponges growing on them. The "irregular" sea urchins are an infra-class inside the Euechinoidea, called Irregularia, and include Atelostomata and Neognathostomata. Irregular echinoids include: flattened sand dollars, sea biscuits, and heart urchins. Together with sea cucumbers (Holothuroidea), they make up the subphylum Echinozoa, which is characterized


title: "Sea urchin" content: by a globoid shape without arms or projecting rays. Sea cucumbers and the irregular echinoids have secondarily evolved diverse shapes. Although many sea cucumbers have branched tentacles surrounding their oral openings, these have originated from modified tube feet and are not homologous to the arms of the crinoids, sea stars, and brittle stars. Urchins typically range in size from , although the largest species can reach up to . They have a rigid, usually spherical body bearing moveable spines, which gives the class the name Echinoidea (from the Greek "ekhinos", spine). The name "urchin" is an old word for hedgehog,


title: "Sea urchin" content: which sea urchins resemble; they have archaically been called sea hedgehogs. The name is derived from Old French "herichun", from Latin "ericius", hedgehog. Like other echinoderms, sea urchin early larvae have bilateral symmetry, but they develop five-fold symmetry as they mature. This is most apparent in the "regular" sea urchins, which have roughly spherical bodies with five equally sized parts radiating out from their central axes. The mouth is at the base of the animal and the anus at the top; the lower surface is described as "oral" and the upper surface as "aboral". Several sea urchins, however, including the


title: "Sea urchin" content: sand dollars, are oval in shape, with distinct front and rear ends, giving them a degree of bilateral symmetry. In these urchins, the upper surface of the body is slightly domed, but the underside is flat, while the sides are devoid of tube feet. This "irregular" body form has evolved to allow the animals to burrow through sand or other soft materials. Sea urchins may appear to be incapable of moving but this is a false impression. Sometimes, the most visible sign of life is the spines, which are attached to ball-and-socket joints and can point in any direction; in


title: "Sea urchin" content: most urchins, touch elicits a prompt reaction from the spines, which converge toward the touched point. Sea urchins have no visible eyes, legs, or means of propulsion, but can move freely but slowly over hard surfaces using adhesive tube feet, working in conjunction with the spines. The internal organs are enclosed in a hard shell or test composed of fused plates of calcium carbonate covered by a thin dermis and epidermis. The test is rigid, and divides into five ambulacral grooves separated by five interambulacral areas. Each of these areas consists of two rows of plates, so the sea urchin


title: "Sea urchin" content: test includes 20 rows of plates in total. The plates are covered in rounded tubercles which contain the sockets to which the spines are attached by ball and socket joints. The inner surface of the test is lined by peritoneum. Sea urchins convert aqueous carbon dioxide using a catalytic process involving nickel into the calcium carbonate portion of the test. Most species have two series of spines, primary (long) and secondary (short), distributed over the surface of the body, with the shortest at the poles and the longest at the equator. The spines are usually hollow and cylindrical. Contraction of


title: "Sea urchin" content: the muscular sheath that covers the test causes the spines to lean in one direction or another, while an inner sheath of collagen fibres can reversibly change from soft to rigid which can lock the spine in one position. Located among the spines are several types of pedicellaria, moveable stalked structures with jaws. Sea urchins move by walking using their many flexible tube feet in a similar way to starfish; regular sea urchins do not have any favourite walking direction. The tube feet protrude through pairs of pores in the test, and are operated by a water vascular system; this


title: "Sea urchin" content: works through hydraulic pressure, allowing the sea urchin to pump water into and out of the tube feet. During locomotion, the tube feet are assisted by the spines which can be used for pushing the body along or to lift the test off the substrate. Movement is generally related to feeding, with the red sea urchin ("Mesocentrotus franciscanus") managing about a day when there is ample food, and up to a day where there is not. An inverted sea urchin can right itself by progressively attaching and detaching its tube feet and manipulating its spines to roll its body upright.


title: "Sea urchin" content: Some species bury themselves in soft sediment using their spines, and "Paracentrotus lividus" uses its jaws to burrow into soft rocks. The mouth lies in the centre of the oral surface in regular urchins, or towards one end in irregular urchins. It is surrounded by lips of softer tissue, with numerous small, embedded bony pieces. This area, called the peristome, also includes five pairs of modified tube feet and, in many species, five pairs of gills. The jaw apparatus consists of five strong arrow-shaped plates known as pyramids, the ventral surface of each of which has a toothband with a


title: "Sea urchin" content: hard tooth pointing towards the centre of the mouth. Specialised muscles control the protrusion of the apparatus and the action of the teeth, and the animal can grasp, scrape, pull and tear. The structure of the mouth and teeth have been found to be so efficient at grasping and grinding that similar structures have been tested for use in real-world applications. On the upper surface of the test at the aboral pole is a membrane, the periproct, which surrounds the anus. The periproct contains a variable number of hard plates, five of which, the genital plates, contain the gonopores, and


title: "Sea urchin" content: one is modified to contain the madreporite, which is used to balance the water vascular system. The mouth of most sea urchins is made up of five calcium carbonate teeth or jaws, with a fleshy, tongue-like structure within. The entire chewing organ is known as Aristotle's lantern from Aristotle's description in his "History of Animals". However, this has recently been proven to be a mistranslation. Aristotle's lantern is actually referring to the whole shape of sea urchins, which look like the ancient lamps of Aristotle's time. Heart urchins are unusual in not having a lantern. Instead, the mouth is surrounded


title: "Sea urchin" content: by cilia that pull strings of mucus containing food particles towards a series of grooves around the mouth. The lantern, where present, surrounds both the mouth cavity and the pharynx. At the top of the lantern, the pharynx opens into the esophagus, which runs back down the outside of the lantern, to join the small intestine and a single caecum. The small intestine runs in a full circle around the inside of the test, before joining the large intestine, which completes another circuit in the opposite direction. From the large intestine, a rectum ascends towards the anus. Despite the names,


title: "Sea urchin" content: the small and large intestines of sea urchins are in no way homologous to the similarly named structures in vertebrates. Digestion occurs in the intestine, with the caecum producing further digestive enzymes. An additional tube, called the siphon, runs beside much of the intestine, opening into it at both ends. It may be involved in resorption of water from food. The water vascular system leads downwards from the madreporite through the slender stone canal to the ring canal, which encircles the oesophagus. Radial canals lead from here through each ambulacral area to terminate in a small tentacle which passes through


title: "Sea urchin" content: the ambulacral plate near the aboral pole. Lateral canals lead from these radial canals, ending in ampullae. From here, two tubes pass through a pair of pores on the plate to terminate in the tube feet. Sea urchins possess a hemal system with a complex network of vessels in the mesenteries around the gut, but little is known of the functioning of this system. However, the main circulatory fluid fills the general body cavity, or coelom. This coelomic fluid contains phagocytic coelomocytes, which move through the vascular and hemal systems and are involved in internal transport and gas exchange. The


title: "Sea urchin" content: coelomocytes are an essential part of blood clotting, but also collect waste products and actively remove them from the body through the gills and tube feet. Most sea urchins possess five pairs of external gills attached to the peristomial membrane around their mouths. These thin-walled projections of the body cavity are the main organs of respiration in those urchins that possess them. Fluid can be pumped through the gills' interiors by muscles associated with the lantern, but this does not provide a continuous flow, and occurs only when the animal is low in oxygen. Tube feet can also act as


title: "Sea urchin" content: respiratory organs, and are the primary sites of gas exchange in heart urchins and sand dollars, both of which lack gills. The inside of each tube foot is divided by a septum which reduces diffusion between the incoming and outgoing streams of fluid. The nervous system of sea urchins has a relatively simple layout. With no true brain, the neural center is a large nerve ring encircling the mouth just inside the lantern. From the nerve ring, five nerves radiate underneath the radial canals of the water vascular system, and branch into numerous finer nerves to innervate the tube feet,


title: "Sea urchin" content: spines, and pedicellariae. Sea urchins are sensitive to touch, light, and chemicals. There are numerous sensitive cells in the epithelium, especially in the spines, pedicellaria and tube feet, and around the mouth. Although they do not have eyes or eye spots (except for diadematids, which can follow a threat with their spines), the entire body of most regular sea urchins might function as a compound eye. In general, sea urchins are negatively attracted to light, and seek to hide themselves in crevices or under objects. Most species, apart from pencil urchins, have statocysts in globular organs called spheridia. These are


title: "Sea urchin" content: stalked structures and are located within the ambulacral areas; their function is to help in gravitational orientation. Sea urchins are dioecious, having separate male and female sexes, although no distinguishing features are visible externally. Regular sea urchins have five gonads, lying underneath the interambulacral regions of the test, while the irregular forms mostly have four, with the hindmost gonad being absent; heart urchins have three or two. Each gonad has a single duct rising from the upper pole to open at a gonopore lying in one of the genital plates surrounding the anus. Some burrowing sand dollars have an elongated


title: "Sea urchin" content: papilla that enables the liberation of gametes above the surface of the sediment. The gonads are lined with muscles underneath the peritoneum, and these allow the animal to squeeze its gametes through the duct and into the surrounding sea water, where fertilization takes place. During early development, the sea urchin embryo undergoes 10 cycles of cell division, resulting in a single epithelial layer enveloping the blastocoel. The embryo then begins gastrulation, a multipart process which dramatically rearranges its structure by invagination to produce the three germ layers, involving an epithelial-mesenchymal transition; primary mesenchyme cells move into the blastocoel and become


title: "Sea urchin" content: mesoderm. An unusual feature of sea urchin development is the replacement of the larva's bilateral symmetry by the adult's broadly fivefold symmetry. During cleavage, mesoderm and small micromeres are specified. At the end of gastrulation, cells of these two types form coelomic pouches. In the larval stages, the adult rudiment grows from the left coelomic pouch; after metamorphosis, that rudiment grows to become the adult. The animal-vegetal axis is established before the egg is fertilized. The oral-aboral axis is specified early in cleavage, and the left-right axis appears at the late gastrula stage. In most cases, the female's eggs float


title: "Sea urchin" content: freely in the sea, but some species hold onto them with their spines, affording them a greater degree of protection. The unfertilized egg meets with the free-floating sperm released by males, and develops into a free-swimming blastula embryo in as few as 12 hours. Initially a simple ball of cells, the blastula soon transforms into a cone-shaped echinopluteus larva. In most species, this larva has 12 elongated arms lined with bands of cilia that capture food particles and transport them to the mouth. In a few species, the blastula contains supplies of nutrient yolk and lacks arms, since it has


title: "Sea urchin" content: no need to feed. Several months are needed for the larva to complete its development, the change into the adult form beginning with the formation of test plates in a juvenile rudiment which develops on the left side of the larva, its axis being perpendicular to that of the larva. Soon, the larva sinks to the bottom and metamorphoses into a juvenile urchin in as little as one hour. In some species, adults reach their maximum size in about five years. The purple urchin becomes sexually mature in two years and may live for twenty. Sea urchins feed mainly on


title: "Sea urchin" content: algae, so they are primarily herbivores, but can feed on sea cucumbers and a wide range of invertebrates, such as mussels, polychaetes, sponges, brittle stars, and crinoids, making them omnivores, consumers at a range of trophic levels. Mass mortality of sea urchins was first reported in the 1970s, but diseases in sea urchins had been little studied before the advent of aquaculture. In 1981, bacterial "spotting disease" caused almost complete mortality in juvenile "Pseudocentrotus depressus" and "Hemicentrotus pulcherrimus", both cultivated in Japan; the disease recurred in succeeding years. It was divided into a cool-water "spring" disease and a hot-water "summer"


title: "Sea urchin" content: form. Another condition, bald sea urchin disease, causes loss of spines and skin lesions and is believed to be bacterial in origin. Adult sea urchins are usually well protected against most predators by their strong and sharp spines, which can be venomous in some species. The small urchin clingfish lives among the spines of urchins such as "Diadema"; juveniles feed on the pedicellariae and sphaeridia, adult males choose the tube feet and adult females move away to feed on shrimp eggs and molluscs. Sea urchins are one of the favourite foods of many lobsters, crabs, triggerfish, California sheephead, sea otter


title: "Sea urchin" content: and wolf eels (which specialise in sea urchins). All these animals carry particular adaptations (teeth, pincers, claws) and a strength that allow them to overcome the excellent protective features of sea urchins. Left unchecked by predators, urchins devastate their environments, creating what biologists call an urchin barren, devoid of macroalgae and associated fauna. Sea otters have re-entered British Columbia, dramatically improving coastal ecosystem health. The spines, long and sharp in some species, protect the urchin from predators. Some tropical sea urchins like Diadematidae, Echinothuriidae and Toxopneustidae have venomous spines. Other creatures also make use of these defences; crabs, shrimps and


title: "Sea urchin" content: other organisms shelter among the spines, and often adopt the colouring of their host. Some crabs in the Dorippidae family carry sea urchins, starfish, sharp shells or other protective objects in their claws. Pedicellaria are a good means of defense against ectoparasites, but not a panacea as some of them actually feed on it. The hemal system defends against endoparasites. Sea urchins are established in most seabed habitats from the intertidal downwards, at an extremely wide range of depths. Some species, such as "Cidaris abyssicola", can live at depths of several thousands metres. Many genera are only found in the


title: "Sea urchin" content: abyssal zone, including many cidaroids, most of the genera in the Echinothuriidae family, and the "cactus urchins" "Dermechinus". One of the deepest-living families is the "Pourtalesiidae", strange bottle-shaped irregular sea urchins that live only in the hadal zone and have been collected as deep as 6850 metres beneath the surface in the Sunda Trench. Nevertheless, this makes sea urchin the class of echinoderms living the least deep, compared to brittle stars, starfish and crinoids that remain abundant below and sea cucumbers which have been recorded from . Population densities vary by habitat, with more dense populations in barren areas as


title: "Sea urchin" content: compared to kelp stands. Even in these barren areas, greatest densities are found in shallow water. Populations are generally found in deeper water if wave action is present. Densities decrease in winter when storms cause them to seek protection in cracks and around larger underwater structures. The shingle urchin ("Colobocentrotus atratus"), which lives on exposed shorelines, is particularly resistant to wave action. It is one of the few sea urchin that can survive many hours out of water. Sea urchins can be found in all climates, from warm seas to polar oceans. The larvae of the polar sea urchin "Sterechinus


title: "Sea urchin" content: neumayeri" have been found to use energy in metabolic processes twenty-five times more efficiently than do most other organisms. Despite their presence in nearly all the marine ecosystems, most species are found on temperate and tropical coasts, between the surface and some tens of meters deep, close to photosynthetic food sources. The earliest echinoid fossils date to the upper part of the Ordovician period ("circa" 450 Mya). There is a rich fossil record, their hard tests made of calcite plates surviving in rocks from every period since then. Spines are present in some well-preserved specimens, but usually only the test


title: "Sea urchin" content: remains. Isolated spines are common as fossils. Some Jurassic and Cretaceous Cidaroida had very heavy, club-shaped spines. Most fossil echinoids from the Paleozoic era are incomplete, consisting of isolated spines and small clusters of scattered plates from crushed individuals, mostly in Devonian and Carboniferous rocks. The shallow-water limestones from the Ordovician and Silurian periods of Estonia are famous for echinoids. Paleozoic echinoids probably inhabited relatively quiet waters. Because of their thin tests, they would certainly not have survived in the wave-battered coastal waters inhabited by many modern echinoids. Echinoids declined to near extinction at the end of the Paleozoic era,


title: "Sea urchin" content: with just six species known from the Permian period. Only two lineages survived this period's massive extinction and into the Triassic: the genus "Miocidaris", which gave rise to modern cidaroida (pencil urchins), and the ancestor that gave rise to the euechinoids. By the upper Triassic, their numbers increased again. Cidaroids have changed very little since the Late Triassic, and are the only Paleozoic echinoid group to have survived. The euechinoids diversified into new lineages in the Jurassic and Cretaceous periods, and from them emerged the first irregular echinoids (the Atelostomata) during the early Jurassic. Some echinoids, such as "Micraster" in


title: "Sea urchin" content: the chalk of the Cretaceous period, serve as zone or index fossils. Because they are abundant and evolved rapidly, they enable geologists to date the surrounding rocks. In the Paleogene and Neogene periods ("circa" 66 to 1.8 Mya), sand dollars (Clypeasteroida) arose. Their distinctive, flattened tests and tiny spines were adapted to life on or under loose sand in shallow water, and they are abundant as fossils in southern European limestones and sandstones. Echinoids are deuterostome animals, like the chordates. A 2014 analysis of 219 genes from all classes of echinoderms gives the following phylogenetic tree. Approximate dates of branching


title: "Sea urchin" content: of major clades are shown in millions of years ago (mya). The phylogeny of the sea urchins is as follows: Sea urchin injuries are puncture wounds inflicted by the animal's brittle, fragile spines. These are a common source of injury to ocean swimmers, especially along coastal surfaces where coral with stationary sea urchins are present. Their stings vary in severity depending on the species. Their spines can be venomous or cause infection. Granuloma and staining of the skin from the natural dye inside the sea urchin can also occur. Breathing problems may indicate a serious reaction to toxins in the


title: "Sea urchin" content: sea urchin. They inflict a painful wound when they penetrate human skin, but are not themselves dangerous if fully removed promptly; if left in the skin, further problems may occur. Sea urchins are traditional model organisms in developmental biology. This use originated in the 1800s, when their embryonic development became easily viewed by microscopy. The transparency of the urchin's eggs enabled them to be used to observe that sperm cells actually fertilize ova. They continue to be used for embryonic studies, as prenatal development continues to seek testing for fatal diseases. Sea urchins are being used in longevity studies for


title: "Sea urchin" content: comparison between the young and old of the species, particularly for their ability to regenerate tissue as needed. Scientists at the University of St Andrews have discovered a genetic sequence, the '2A' region, in sea urchins previously thought to have belonged only to viruses that afflict humans like foot-and-mouth disease virus. More recently, Eric H. Davidson and Roy John Britten argued for the use of urchins as a model organism due to their easy availability, high fecundity, and long lifespan. Beyond embryology, urchins provide an opportunity to research cis-regulatory elements. Oceanography has taken in interest in monitoring the health of


title: "Sea urchin" content: urchins and their populations as a way to assess overall ocean acidification, temperatures, and ecological impacts. The organism's evolutionary placement and unique embryology with five-fold symmetry were the major arguments in the proposal to seek the sequencing of its genome. Importantly, urchins act as the closest living relative to chordates and thus are of interest for the light they can shed on the evolution of vertebrates. The genome of "Strongylocentrotus purpuratus", was completed in 2006 and established homology between sea urchin and vertebrate immune system-related genes. Sea urchins code for at least 222 Toll-like receptor genes and over 200 genes


title: "Sea urchin" content: related to the Nod-like-receptor family found in vertebrates. This increases its usefulness as a valuable model organism for studying the evolution of innate immunity. The sequencing also revealed that while some genes were thought to be limited to vertebrates, there were also innovations that have previously never been seen outside the chordate classification, such as immune transcription factors PU.1 and SPIB. The gonads of both male and female sea urchins, usually called sea urchin roe or corals, are culinary delicacies in many parts of the world. In Mediterranean cuisines, "Paracentrotus lividus" is often eaten raw, or with lemon, and known


title: "Sea urchin" content: as "ricci" on Italian menus where it is sometimes used in pasta sauces. It can also flavour omelettes, scrambled eggs, fish soup, mayonnaise, béchamel sauce for tartlets, the "boullie" for a soufflé, or Hollandaise sauce to make a fish sauce. In Chilean cuisine, it is served raw with lemon, onions, and olive oil. Though the edible "Strongylocentrotus droebachiensis" is found in the North Atlantic, it is not widely eaten. However, sea urchins (called "uutuk" in Alutiiq) are commonly eaten by the Alaska Native population around Kodiak Island. It is commonly exported, mostly to Japan. In the West Indies, slate pencil


title: "Sea urchin" content: urchins are eaten. On the Pacific Coast of North America, "Strongylocentrotus franciscanus" was praised by Euell Gibbons; "Strongylocentrotus purpuratus" is also eaten. In New Zealand, "Evechinus chloroticus", known as "kina" in Maori, is a delicacy, traditionally eaten raw. Though New Zealand fishermen would like to export them to Japan, their quality is too variable. In Japan, sea urchin is known as , and its roe can retail for as much as ¥40000 ($360) per kg; it is served raw as "sashimi" or in "sushi", with soy sauce and "wasabi". Japan imports large quantities from the United States, South Korea, and


title: "Sea urchin" content: other producers. Japan consumes 50,000 tons annually amounting to over 80% of global production. Japanese demand for sea urchin corals has raised concerns about overfishing. Native Americans in California are also known to eat sea urchins. The coast of Southern California is known as a source of high quality uni, with divers picking sea urchin from kelp beds in depths as low as 24 m/80 ft. As of 2013, the state was limiting the practice to 300 sea urchin diver licenses. Some species of sea urchins, such as the slate pencil urchin ("Eucidaris tribuloides"), are commonly sold in aquarium stores.


title: "Sea urchin" content: Some species are effective at controlling filamentous algae, and they make good additions to an invertebrate tank. A folk tradition in Denmark and southern England imagined sea urchin fossils to be thunderbolts, able to ward off harm by lightning or by witchcraft, as an apotropaic symbol. Another version supposed they were petrified eggs of snakes, able to protect against heart and liver disease, poisons, and injury in battle, and accordingly they were carried as amulets. These were, according to the legend, created by magic from foam made by the snakes at midsummer. Sea urchin Sea urchins or urchins () are


title: "Barn swallow" content: Barn swallow The barn swallow ("Hirundo rustica") is the most widespread species of swallow in the world. It is a distinctive passerine bird with blue upperparts and a long, deeply forked tail. It is found in Europe, Asia, Africa and the Americas. In Anglophone Europe it is just called the swallow; in Northern Europe it is the only common species called a "swallow" rather than a "martin". There are six subspecies of barn swallow, which breed across the Northern Hemisphere. Four are strongly migratory, and their wintering grounds cover much of the Southern Hemisphere as far south as central Argentina,


title: "Barn swallow" content: the Cape Province of South Africa, and northern Australia. Its huge range means that the barn swallow is not endangered, although there may be local population declines due to specific threats. The barn swallow is a bird of open country that normally uses man-made structures to breed and consequently has spread with human expansion. It builds a cup nest from mud pellets in barns or similar structures and feeds on insects caught in flight. This species lives in close association with humans, and its insect-eating habits mean that it is tolerated by humans; this acceptance was reinforced in the past


title: "Barn swallow" content: by superstitions regarding the bird and its nest. There are frequent cultural references to the barn swallow in literary and religious works due to both its living in close proximity to humans and its annual migration. The barn swallow is the national bird of Estonia. The adult male barn swallow of the nominate subspecies "H. r. rustica" is long including of elongated outer tail feathers. It has a wingspan of and weighs . It has steel blue upperparts and a rufous forehead, chin and throat, which are separated from the off-white underparts by a broad dark blue breast band. The


title: "Barn swallow" content: outer tail feathers are elongated, giving the distinctive deeply forked "swallow tail". There is a line of white spots across the outer end of the upper tail. The female is similar in appearance to the male, but the tail streamers are shorter, the blue of the upperparts and breast band is less glossy, and the underparts paler. The juvenile is browner and has a paler rufous face and whiter underparts. It also lacks the long tail streamers of the adult. The song of the barn swallow is a cheerful warble, often ending with "su-seer" with the second note higher than


title: "Barn swallow" content: the first but falling in pitch. Calls include "witt" or "witt-witt" and a loud "splee-plink" when excited (or trying to chase intruders away from the nest). The alarm calls include a sharp "siflitt" for predators like cats and a "flitt-flitt" for birds of prey like the hobby. This species is fairly quiet on the wintering grounds. The distinctive combination of a red face and blue breast band render the adult barn swallow easy to distinguish from the African "Hirundo" species and from the welcome swallow ("Hirundo neoxena") with which its range overlaps in Australasia. In Africa the short tail streamers


title: "Barn swallow" content: of the juvenile barn swallow invite confusion with juvenile red-chested swallow ("Hirundo lucida"), but the latter has a narrower breast band and more white in the tail. The barn swallow was described by Linnaeus in his "Systema Naturae" in 1758 as "Hirundo rustica", characterised as "H. rectricibus, exceptis duabus intermediis, macula alba notatîs". "Hirundo" is the Latin word for "swallow"; "rusticus" means "of the country". This species is the only one of that genus to have a range extending into the Americas, with the majority of "Hirundo" species being native to Africa. This genus of blue-backed swallows is sometimes called


title: "Barn swallow" content: the "barn swallows". The "Oxford English Dictionary" dates the English common name "barn swallow" to 1851, though an earlier instance of the collocation in an English-language context is in Gilbert White's popular book "The Natural History of Selborne", originally published in 1789: The swallow, though called the chimney-swallow, by no means builds altogether in chimnies , but often within barns and out-houses against the rafters ... In "Sweden" she builds in barns, and is called "ladusvala", the barn-swallow. This suggests that the English name may be a calque on the Swedish term. There are few taxonomic problems within the genus,


title: "Barn swallow" content: but the red-chested swallow—a resident of West Africa, the Congo basin, and Ethiopia—was formerly treated as a subspecies of barn swallow. The red-chested swallow is slightly smaller than its migratory relative, has a narrower blue breast-band, and (in the adult) has shorter tail streamers. In flight, it looks paler underneath than barn swallow. Six subspecies of barn swallow are generally recognised. In eastern Asia, a number of additional or alternative forms have been proposed, including "saturata" by Robert Ridgway in 1883, "kamtschatica" by Benedykt Dybowski in 1883, "ambigua" by Erwin Stresemann and "mandschurica" by Wilhelm Meise in 1934. Given the


title: "Barn swallow" content: uncertainties over the validity of these forms, this article follows the treatment of Turner and Rose. The short wings, red belly and incomplete breast band of "H. r. tytleri" are also found in "H. r. erythrogaster", and DNA analyses show that barn swallows from North America colonised the Baikal region of Siberia, a dispersal direction opposite to that for most changes in distribution between North America and Eurasia. The preferred habitat of the barn swallow is open country with low vegetation, such as pasture, meadows and farmland, preferably with nearby water. This swallow avoids heavily wooded or precipitous areas and


title: "Barn swallow" content: densely built-up locations. The presence of accessible open structures such as barns, stables, or culverts to provide nesting sites, and exposed locations such as wires, roof ridges or bare branches for perching, are also important in the bird's selection of its breeding range. It breeds in the Northern Hemisphere from sea level to typically , but to in the Caucasus and North America, and it is absent only from deserts and the cold northernmost parts of the continents. Over much of its range, it avoids towns, and in Europe is replaced in urban areas by the house martin. However, in


title: "Barn swallow" content: Honshū, Japan, the barn swallow is a more urban bird, with the red-rumped swallow ("Cecropis daurica") replacing it as the rural species. In winter, the barn swallow is cosmopolitan in its choice of habitat, avoiding only dense forests and deserts. It is most common in open, low vegetation habitats, such as savanna and ranch land, and in Venezuela, South Africa and Trinidad and Tobago it is described as being particularly attracted to burnt or harvested sugarcane fields and the waste from the cane. In the absence of suitable roost sites, they may sometimes roost on wires where they are more


title: "Barn swallow" content: exposed to predators. Individual birds tend to return to the same wintering locality each year and congregate from a large area to roost in reed beds. These roosts can be extremely large; one in Nigeria had an estimated 1.5 million birds. These roosts are thought to be a protection from predators, and the arrival of roosting birds is synchronised in order to overwhelm predators like African hobbies. The barn swallow has been recorded as breeding in the more temperate parts of its winter range, such as the mountains of Thailand and in central Argentina. Migration of barn swallows between Britain


title: "Barn swallow" content: and South Africa was first established on 23 December 1912 when a bird that had been ringed by James Masefield at a nest in Staffordshire, was found in Natal. As would be expected for a long-distance migrant, this bird has occurred as a vagrant to such distant areas as Hawaii, Bermuda, Greenland, Tristan da Cunha the Falkland Islands, and even Antarctica. The barn swallow is similar in its habits to other aerial insectivores, including other swallow species and the unrelated swifts. It is not a particularly fast flier, with a speed estimated at about 11 m/s, up to 20 m/s


title: "Barn swallow" content: and a wing beat rate of approximately 5, up to 7–9 times each second. The barn swallow typically feeds in open areas above shallow water or the ground often following animals, humans or farm machinery to catch disturbed insects, but it will occasionally pick prey items from the water surface, walls and plants. In the breeding areas, large flies make up around 70% of the diet, with aphids also a significant component. However, in Europe, the barn swallow consumes fewer aphids than the house or sand martins. On the wintering grounds, Hymenoptera, especially flying ants, are important food items. When


title: "Barn swallow" content: egg-laying, barn swallows hunt in pairs, but will form often large flocks otherwise. The amount of food a clutch will get depends on the size of the clutch, with larger clutches getting more food on average. The timing of a clutch also determines the food given; later broods get food that is smaller in size compared to earlier broods. This is because larger insects are too far away from the nest to be profitable in terms of energy expenditure. Isotope studies have shown that wintering populations may utilise different feeding habitats, with British breeders feeding mostly over grassland, whereas Swiss


title: "Barn swallow" content: birds utilised woodland more. Another study showed that a single population breeding in Denmark actually wintered in two separate and different areas. The barn swallow drinks by skimming low over lakes or rivers and scooping up water with its open mouth. This bird bathes in a similar fashion, dipping into the water for an instant while in flight. Swallows gather in communal roosts after breeding, sometimes thousands strong. Reed beds are regularly favoured, with the birds swirling "en masse" before swooping low over the reeds. Reed beds are an important source of food prior to and whilst on migration; although


title: "Barn swallow" content: the barn swallow is a diurnal migrant that can feed on the wing whilst it travels low over ground or water, the reed beds enable fat deposits to be established or replenished. The male barn swallow returns to the breeding grounds before the females and selects a nest site, which is then advertised to females with a circling flight and song. Plumage may be used to advertise: in some populations, like in the subspecies "H. r. gutturalis", darker ventral plumage in males is associated with higher breeding success. In other populations, the breeding success of the male is related to


title: "Barn swallow" content: the length of the tail streamers, with longer streamers being more attractive to the female. Males with longer tail feathers are generally longer-lived and more disease resistant, females thus gaining an indirect fitness benefit from this form of selection, since longer tail feathers indicate a genetically stronger individual which will produce offspring with enhanced vitality. Males in northern Europe have longer tails than those further south; whereas in Spain the male's tail streamers are only 5% longer than the female's, in Finland the difference is 20%. In Denmark, the average male tail length increased by 9% between 1984 and 2004,


title: "Barn swallow" content: but it is possible that climatic changes may lead in the future to shorter tails if summers become hot and dry. Males with long streamers also have larger white tail spots, and since feather-eating bird lice prefer white feathers, large white tail spots without parasite damage again demonstrate breeding quality; there is a positive association between spot size and the number of offspring produced each season. The breeding season of the barn swallow is variable; in the southern part of the range, the breeding season usually is from February or March to early to mid September, although some late second


title: "Barn swallow" content: and third broods finish in October. In the northern part of the range, it usually starts late May to early June and ends the same time as the breeding season of the southernmost birds. Both sexes defend the nest, but the male is particularly aggressive and territorial. Once established, pairs stay together to breed for life, but extra-pair copulation is common, making this species genetically polygamous, despite being socially monogamous. Males guard females actively to avoid being cuckolded. Males may use deceptive alarm calls to disrupt extrapair copulation attempts toward their mates. As its name implies, the barn swallow typically


title: "Barn swallow" content: nests inside accessible buildings such as barns and stables, or under bridges and wharves. Before man-made sites became common, it nested on cliff faces or in caves, but this is now rare. The neat cup-shaped nest is placed on a beam or against a suitable vertical projection. It is constructed by both sexes, although more often by the female, with mud pellets collected in their beaks and lined with grasses, feathers, algae or other soft materials. The nest building ability of the male is also sexually selected; females will lay more eggs and at an earlier date with males who


title: "Barn swallow" content: are better at nest construction, with the opposite being true with males that are not. After building the nest, barn swallows may nest colonially where sufficient high-quality nest sites are available, and within a colony, each pair defends a territory around the nest which, for the European subspecies, is in size. Colony size tends to be larger in North America. In North America at least, barn swallows frequently engage in a mutualist relationship with ospreys. Barn swallows will build their nest below an osprey nest, receiving protection from other birds of prey that are repelled by the exclusively fish-eating ospreys.


title: "Barn swallow" content: The ospreys are alerted to the presence of these predators by the alarm calls of the swallows. There are normally two broods, with the original nest being reused for the second brood and being repaired and reused in subsequent years. The female lays two to seven, but typically four or five, reddish-spotted white eggs. The clutch size is influenced by latitude, with clutch sizes of northern populations being higher on average than southern populations. The eggs are in size, and weigh , of which 5% is shell. In Europe, the female does almost all the incubation, but in North America


title: "Barn swallow" content: the male may incubate up to 25% of the time. The incubation period is normally 14–19 days, with another 18–23 days before the altricial chicks fledge. The fledged young stay with, and are fed by, the parents for about a week after leaving the nest. Occasionally, first-year birds from the first brood will assist in feeding the second brood. Compared to those from early broods, juvenile barn swallows from late broods have been found to migrate at a younger age, fuel less efficiently during migration and have lower return rates the following year. The barn swallow will mob intruders such


title: "Barn swallow" content: as cats or accipiters that venture too close to their nest, often flying very close to the threat. Adult barn swallows have few predators, but some are taken by accipiters, falcons, and owls. Brood parasitism by cowbirds in North America or cuckoos in Eurasia is rare. Hatching success is 90% and the fledging survival rate is 70–90%. Average mortality is 70–80% in the first year and 40–70% for the adult. Although the record age is more than 11 years, most survive less than four years. Barn swallow nestlings have prominent red gapes, a feature shown to induce feeding by parent


title: "Barn swallow" content: birds. An experiment in manipulating brood size and immune system showed the vividness of the gape was positively correlated with T-cell–mediated immunocompetence, and that larger brood size and injection with an antigen led to a less vivid gape. The barn swallow has been recorded as hybridising with the cliff swallow ("Petrochelidon pyrrhonota") and the cave swallow ("P. fulva") in North America, and the house martin ("Delichon urbicum") in Eurasia, the cross with the latter being one of the most common passerine hybrids. Barn swallows (and other small passerines) often have characteristic feather holes on their wing and tail feathers. These


title: "Barn swallow" content: holes were suggested as being caused by avian lice such as "Machaerilaemus malleus" and "Myrsidea rustica", although other studies suggest that they are mainly caused by species of "Brueelia". Several other species of lice have been described from barn swallow hosts, including "Brueelia domestica" and "Philopterus microsomaticus". The avian lice prefer to feed on white tail spots, and they are generally found more numerously on short-tailed males, indicating the function of unbroken white tail spots as a measure of quality. In Texas, the swallow bug ("Oeciacus vicarius"), which is common on species such as the cliff swallow, is also known


title: "Barn swallow" content: to infest barn swallows. Predatory bats such as the greater false vampire bat are known to prey on barn swallows. Swallows at their communal roosts attract predators and several falcon species make use of these opportunities. Falcon species confirmed as predators include the peregrine falcon and the African hobby. The barn swallow has an enormous range, with an estimated global extent of and a population of 190 million individuals. The species is evaluated as least concern on the 2007 IUCN Red List, and has no special status under the Convention on International Trade in Endangered Species of Wild Fauna and


title: "Barn swallow" content: Flora (CITES), which regulates international trade in specimens of wild animals and plants. This is a species that has greatly benefited historically from forest clearance, which has created the open habitats it prefers, and from human habitation, which have given it an abundance of safe man-made nest sites. There have been local declines due to the use of DDT in Israel in the 1950s, competition for nest sites with house sparrows in the US in the 19th century, and an ongoing gradual decline in numbers in parts of Europe and Asia due to agricultural intensification, reducing the availability of insect


title: "Barn swallow" content: food. However, there has been an increase in the population in North America during the 20th century with the greater availability of nesting sites and subsequent range expansion, including the colonisation of northern Alberta. A specific threat to wintering birds from the European populations is the transformation by the South African government of a light aircraft runway near Durban into an international airport for the 2010 FIFA World Cup. The roughly square Mount Moreland reed bed is a night roost for more than three million barn swallows, which represent 1% of the global population and 8% of the European breeding


title: "Barn swallow" content: population. The reed bed lies on the flight path of aircraft using the proposed La Mercy airport, and there were fears that it would be cleared because the birds could threaten aircraft safety. However, following detailed evaluation, advanced radar technology will be installed to enable planes using the airport to be warned of bird movements and, if necessary, take appropriate measures to avoid the flocks. Climate change may affect the barn swallow; drought causes weight loss and slow feather regrowth, and the expansion of the Sahara will make it a more formidable obstacle for migrating European birds. Hot dry summers


title: "Barn swallow" content: will reduce the availability of insect food for chicks. Conversely, warmer springs may lengthen the breeding season and result in more chicks, and the opportunity to use nest sites outside buildings in the north of the range might also lead to more offspring. The barn swallow is an attractive bird that feeds on flying insects and has therefore been tolerated by humans when it shares their buildings for nesting. As one of the earlier migrants, this conspicuous species is also seen as an early sign of summer's approach. In the Old World, the barn swallow appears to have used man-made


title: "Barn swallow" content: structures and bridges since time immemorial. An early reference is in Virgil's "Georgics" (29 BC), ""Ante garrula quam tignis nidum suspendat hirundo"" (Before the twittering swallow hangs its nest from the rafters). Many cattle farmers believed that swallows spread "Salmonella" infections, however a study in Sweden showed no evidence of the birds being reservoirs of the bacteria. Many literary references are based on the barn swallow's northward migration as a symbol of spring or summer. The proverb about the necessity for more than one piece of evidence goes back at least to Aristotle's "Nicomachean Ethics": "For as one swallow or


title: "Barn swallow" content: one day does not make a spring, so one day or a short time does not make a fortunate or happy man." The barn swallow symbolises the coming of spring and thus love in the "Pervigilium Veneris", a late Latin poem. In his poem "The Waste Land", T. S. Eliot quoted the line ""Quando fiam uti chelidon [ut tacere desinam]?"" ("When will I be like the swallow, so that I can stop being silent?") This refers to the myth of Philomela in which she turns into a nightingale, and her sister Procne into a swallow. On the other hand, an


title: "Barn swallow" content: image of the assembly of swallows for their southward migration concludes John Keats's ode "To Autumn". The swallow is cited in several of William Shakespeare's plays for the swiftness of its flight, with "True hope is swift, and flies with swallow's wings" from Act 5 of "Richard III", and "I have horse will follow where the game Makes way, and run like swallows o'er the plain." from the second act of "Titus Andronicus". Shakespeare references the annual migration of the species in "The Winter's Tale", Act 4: "Daffodils, That come before the swallow dares, and take The winds of March


title: "Barn swallow" content: with beauty". Gilbert White studied the barn swallow in detail in his pioneering work "The Natural History of Selborne", but even this careful observer was uncertain whether it migrated or hibernated in winter. Elsewhere, its long journeys have been well observed, and a swallow tattoo is popular amongst nautical men as a symbol of a safe return; the tradition was that a mariner had a tattoo of this fellow wanderer after sailing . A second swallow would be added after at sea. In the past, the tolerance for this beneficial insectivore was reinforced by superstitions regarding damage to the barn


title: "Barn swallow" content: swallow's nest. Such an act might lead to cows giving bloody milk, or no milk at all, or to hens ceasing to lay. This may be a factor in the longevity of swallows' nests. Survival, with suitable annual refurbishment, for 10–15 years is regular, and one nest was reported to have been occupied for 48 years. It is depicted as the "Martlet", "Merlette" or "Merlot" in heraldry, where it represents younger sons who have no lands. It is also represented as lacking feet as this was a common belief at the time. As a result of a campaign by ornithologists,


title: "Barn swallow" content: the barn swallow has been the national bird of Estonia since 23 June 1960. Barn swallow The barn swallow ("Hirundo rustica") is the most widespread species of swallow in the world. It is a distinctive passerine bird with blue upperparts and a long, deeply forked tail. It is found in Europe, Asia, Africa and the Americas. In Anglophone Europe it is just called the swallow; in Northern Europe it is the only common species called a "swallow" rather than a "martin". There are six subspecies of barn swallow, which breed across the Northern Hemisphere. Four are strongly migratory, and their


title: Bastille content: area, frequented by foreign visitors and tourists, but few went beyond the Bastille into the faubourg. The faubourg was characterised by its built-up, densely populated areas, particularly in the north, and its numerous workshops producing soft furnishings. Paris as a whole had continued to grow, reaching slightly less than 800,000 inhabitants by the reign of Louis XVI, and many of the residents around the faubourg had migrated to Paris from the countryside relatively recently. The Bastille had its own street address, being officially known as No. 232, rue Saint-Antoine. Structurally, the late-18th century Bastille was not greatly changed from its


title: Peshawar content: its former name "Parashāwar", transcribed in Persian as "پَرَشَاوَر", and "Peshāwar" ("پشاور"). Peshawar was founded as the ancient city of "Puruṣapura", on the Gandhara Plains in the broad Valley of Peshawar. The city likely first existed as a small village in the 5th century BCE, within the cultural sphere of eastern ancient Persia. Puruṣapura was founded near the ancient Gandharan capital city of Pushkalavati, near present-day Charsadda. In the winter of 327–26 BCE, Alexander the Great subdued the Valley of Peshawar during his invasion of ancient India, as well as the nearby Swat and Buner valleys. Following Alexander's conquest, the


title: "Lockheed Martin F-22 Raptor" content: "to conduct a comprehensive assessment and study of the costs associated with resuming production of F-22 aircraft." Defense Secretary Robert Gates had production halted at 187 F-22s (at a cost of $67 billion) to direct funds for ongoing irregular warfare operations in Iraq and Afghanistan. Since then, lawmakers and the Pentagon noted that air warfare systems of Russia and China were catching up to U.S. air superiority capabilities. Previous estimates of restarting production placed figures at around $2 billion, including $300–500 million in non-recurring start-up costs, with an estimated unit cost of $233 million for a production run of 75


title: "Heavy Metal (magazine)" content: be designed through a collaboration between PinHeadz, the pinball artist Zombie Yeti (known for his work on tables such as Stern's Ghostbusters) and legendary pinball designer Pat Lawlor, who has designed games such as "Twilight Zone" and "The Addams Family". Heavy Metal (magazine) Heavy Metal is an American science fiction and fantasy comics magazine, known primarily for its blend of dark fantasy/science fiction and erotica. In the mid-1970s, while publisher Leonard Mogel was in Paris to jump-start the French edition of "National Lampoon", he discovered the French science-fantasy magazine "Métal Hurlant" which had debuted January 1975. The French title translates


title: "Stanley Cup" content: version was made in secret, and its production was revealed only three years later. The replicated "Permanent Cup", was created in 1993 by Montreal silversmith Louise St. Jacques to be used as a stand-in at the Hockey Hall of Fame whenever the Presentation Cup is not available for display. There are very few differences between the authenticated version and the Hockey Hall of Fame version. The surest way to identify one version from the other is to check the engraving for the 1984 Stanley Cup winning Edmonton Oilers. The authenticated version has x's engraved over Basil Pocklington's name whereas his


title: "Clinical death" content: can be stopped in the entire body below the heart for at least 30 minutes, with injury to the spinal cord being a limiting factor. Detached limbs may be successfully reattached after 6 hours of no blood circulation at warm temperatures. Bone, tendon, and skin can survive as long as 8 to 12 hours. The brain, however, appears to accumulate ischemic injury faster than any other organ. Without special treatment after circulation is restarted, full recovery of the brain after more than 3 minutes of clinical death at normal body temperature is rare. Usually brain damage or later brain death


title: "Dietary fiber" content: 101.77, and 101.78). In December 2016, FDA approved a qualified health claim that consuming resistant starch from high-amylose corn may reduce the risk of type 2 diabetes due to its effect of increasing insulin sensitivity. The allowed claim specified: "High-amylose maize resistant starch may reduce the risk of type 2 diabetes. FDA has concluded that there is limited scientific evidence for this claim." Dietary fiber Dietary fiber or roughage is the portion of plant-derived food that cannot be completely broken down by digestive enzymes. It has two main components: Dietary fiber consists of non-starch polysaccharides and other plant components such


title: Broccoli content: Broccoli Broccoli is an edible green plant in the cabbage family whose large flowering head is eaten as a vegetable. The word "broccoli" comes from the Italian plural of "", which means "the flowering crest of a cabbage", and is the diminutive form of "brocco", meaning "small nail" or "sprout". Broccoli is often boiled or steamed but may be eaten raw. Broccoli is classified in the Italica cultivar group of the species "Brassica oleracea". Broccoli has large flower heads, usually green in color, arranged in a tree-like structure branching out from a thick, edible stalk. The mass of flower heads


title: Broccoli content: is surrounded by leaves. Broccoli resembles cauliflower, which is a different cultivar group of the same species. Broccoli resulted from breeding of cultivated "Brassica" crops in the northern Mediterranean starting in about the 6th century BC. Since the time of the Roman Empire, broccoli has been commonly consumed among Italians. Combined in 2016, China and India produced 73% of the world's broccoli and cauliflower crops. There are three commonly grown types of broccoli. The most familiar is Calabrese broccoli, often referred to simply as "broccoli", named after Calabria in Italy. It has large (10 to 20 cm) green heads and


title: Broccoli content: thick stalks. It is a cool season annual crop. Sprouting broccoli has a larger number of heads with many thin stalks. Purple cauliflower is a type of broccoli grown in Europe and North America. It has a head shaped like cauliflower, but consisting of tiny flower buds. It sometimes, but not always, has a purple cast to the tips of the flower buds. Other cultivar groups of "Brassica oleracea" include cabbage (Capitata Group), cauliflower and Romanesco broccoli (Botrytis Group), kale and collard greens (Acephala Group), kohlrabi (Gongylodes Group), Brussels sprouts (Gemmifera Group), and kai-lan (Alboglabra Group). Rapini, sometimes called "broccoli


title: Broccoli content: raab" among other names, forms similar but smaller heads, and is actually a type of turnip ("Brassica rapa"). Broccolini or "Tenderstem broccoli" is a cross between broccoli and Chinese broccoli. Beneforté is a variety of broccoli containing 2–3 times more glucoraphanin that was produced by crossing broccoli with a wild Brassica variety, "Brassica oleracea" var "villosa". In 2016, global production of broccoli (combined for production reports with cauliflowers) was 25.2 million tonnes, with China and India together accounting for 73% of the total (table). Secondary producers, each having one million tonnes or less annually, were the United States, Spain, Mexico


title: Broccoli content: and Italy (table). In the United States, the US Department of Agriculture reported that national production just of broccoli in 2014 was 0.95 million tonnes, nearly all of which was grown in California. Broccoli is a cool-weather crop that does poorly in hot summer weather. Broccoli grows best when exposed to an average daily temperature between . When the cluster of flowers, also referred to as a "head" of broccoli, appear in the center of the plant, the cluster is green. Garden pruners or shears are used to cut the head about an inch from the tip. Broccoli should be


title: Broccoli content: harvested before the flowers on the head bloom bright yellow. While the heading broccoli variety performs poorly in hot weather, mainly due to insect infestation, the sprouting variety is more resistant, though attention must be paid to sucking insects (such as aphids), caterpillars and whiteflies. Spraying of "bacillus thuringiensis" can control caterpillar attacks, while a citronella vase may ward off whiteflies. Mostly introduced by accident to North America, Australia and New Zealand, "cabbage worms", the larvae of "Pieris rapae", the small white butterfly are a common pest in broccoli. A 100 gram serving of raw broccoli provides 34 kcal and


title: Broccoli content: is an excellent source (20% or higher of the Daily Value, DV) of vitamin C and vitamin K. Raw broccoli also contains moderate amounts (10–19% DV) of several B vitamins and the dietary mineral manganese, whereas other essential nutrients are in low content. Broccoli has low content of carbohydrates, protein, fat, and dietary fiber. Boiling broccoli reduces the levels of sulforaphane, with losses of 20–30% after five minutes, 40–50% after ten minutes, and 77% after thirty minutes. However, other preparation methods such as steaming, microwaving, and stir frying had no significant effect on the compounds. Broccoli also contains the carotenoid


title: Broccoli content: compounds lutein and zeaxanthin in amounts about 6 times lower than in kale. The perceived bitterness of cruciferous vegetables such as broccoli varies from person to person, but the functional underpinnings of this variation are not known. Some research reports that the gene TAS2R38 may be responsible for bitter taste perception in broccoli. Other factors, such as isothiocyanates and polyphenols, are also likely involved in bitterness perception. Broccoli Broccoli is an edible green plant in the cabbage family whose large flowering head is eaten as a vegetable. The word "broccoli" comes from the Italian plural of "", which means "the


title: "Passive solar building design" content: 20 to 30 cm), using window glazing on the outdoor space to prevent heat loss, dedicating 15–20% of floor area for thermal storage, and implementing a Trombe wall to absorb heat entering the space. Overhangs are used to block direct sunlight in the summer, and allow it in the winter, and heat reflecting blinds are inserted between the thermal wall and the glazing to limit heat build-up in the summer months. Another study analyzed double-green skin facade (DGSF) on the outside of high rise buildings in Hong Kong. Such a green facade, or vegetation covering the outer walls, can combat


title: "Thermal mass" content: For bodies made of many materials, the sum of heat capacities for their pure components may be used in the calculation, or in some cases (as for a whole animal, for example) the number may simply be measured for the entire body in question, directly. As an extensive property, heat capacity is characteristic of an object; its corresponding intensive property is specific heat capacity, expressed in terms of a measure of the amount of material such as mass or number of moles, which must be multiplied by similar units to give the heat capacity of the entire body of material.


title: Tutsi content: were murdered by the former and "at least as many" were killed by the latter. Since the 2000 Arusha Peace Process, today in Burundi the Tutsi minority shares power in a more or less equitable manner with the Hutu majority. Traditionally, the Tutsi had held more economic power and controlled the military. A similar pattern of events took place in Rwanda, but there the Hutu came to power in 1962. They in turn often oppressed the Tutsi, who fled the country. After the anti-Tutsi violence around 1959-1961, Tutsis fled in large numbers. These exile Tutsi communities gave rise to Tutsi


title: Equisetum content: Equisetum Equisetum (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of vascular plants that reproduce by spores rather than seeds. "Equisetum" is a "living fossil" as it is the only living genus of the entire class Equisetopsida, which for over one hundred million years was much more diverse and dominated the understory of late Paleozoic forests. Some Equisetopsida were large trees reaching to 30 meters tall. The genus "Calamites" of the family Calamitaceae, for example, is abundant in coal deposits from the Carboniferous period. The pattern of spacing of nodes in horsetails, wherein those


title: Equisetum content: toward the apex of the shoot are increasingly close together, inspired John Napier to invent logarithms. A superficially similar but entirely unrelated flowering plant genus, mare's tail ("Hippuris"), is occasionally referred to as "horsetail", and adding to confusion, the name mare's tail is sometimes applied to "Equisetum". Despite centuries of use in traditional medicine, there is no evidence that "Equisetum" has any medicinal properties. The name "horsetail", often used for the entire group, arose because the branched species somewhat resemble a horse's tail. Similarly, the scientific name "Equisetum" is derived from the Latin "equus" ("horse") + "seta" ("bristle"). Other names


title: Equisetum content: include candock for branching individuals, and snake grass or scouring-rush for unbranched or sparsely branched individuals. The latter name refers to the rush-like appearance of the plants, and to the fact that the stems are coated with abrasive silicates, making them useful for scouring (cleaning) metal items such as cooking pots or drinking mugs, particularly those made of tin. In German, the corresponding name is "Zinnkraut" ("tin-herb"). Rough horsetail "E. hyemale" is still boiled and then dried in Japan, to be used for the final polishing process on woodcraft to produce a smoother finish than any sandpaper. In Spanish-speaking countries,


title: Equisetum content: these plants are known as "cola de caballo," meaning "horsetail". In these plants the leaves are greatly reduced and usually non-photosynthetic. They contain a single, non-branching vascular trace, which is the defining feature of microphylls. However, it has recently been recognised that horsetail microphylls are probably not ancestral as in Lycopodiophyta (clubmosses and relatives), but rather derived adaptations, evolved by reduction of megaphylls. They are, therefore, sometimes referred to as megaphylls to reflect this homology. The leaves of horsetails are arranged in whorls fused into nodal sheaths. The stems are usually green and photosynthetic, and are distinctive in being hollow,


title: Equisetum content: jointed and ridged (with sometimes 3 but usually 6–40 ridges). There may or may not be whorls of branches at the nodes. The spores are borne under sporangiophores in strobili, cone-like structures at the tips of some of the stems. In many species the cone-bearing shoots are unbranched, and in some (e.g. field horsetail, "E. arvense") they are non-photosynthetic, produced early in spring. In some other species (e.g. marsh horsetail, "E. palustre") they are very similar to sterile shoots, photosynthetic and with whorls of branches. Horsetails are mostly homosporous, though in the field horsetail smaller spores give rise to male


title: Equisetum content: prothalli. The spores have four elaters that act as moisture-sensitive springs, assisting spore dispersal through crawling and hopping motions after the sporangia have split open longitudinally. The crude cell extracts of all "Equisetum" species tested contain (MXE) activity. This is a novel enzyme and is not known to occur in any other plants. In addition, the cell walls of all "Equisetum" species tested contain mixed-linkage glucan (MLG), a polysaccharide which, until recently, was thought to be confined to the Poales. The evolutionary distance between "Equisetum" and the Poales suggests that each evolved MLG independently. The presence of MXE activity in


title: Equisetum content: "Equisetum" suggests that they have evolved MLG along with some mechanism of cell wall modification. The lack of MXE in the Poales suggests that there it must play some other, currently unknown, role. Due to the correlation between MXE activity and cell age, MXE has been proposed to promote the cessation of cell expansion. The living members of the genus "Equisetum" are divided into two distinct lineages, which are usually treated as subgenera. The name of the type subgenus, "Equisetum", means "horse hair" in Latin, while the name of the other subgenus, "Hippochaete", means "horse hair" in Greek. Hybrids are


title: Equisetum content: common, but hybridization has only been recorded between members of the same subgenus. While plants of subgenus "Equisetum" are usually referred to as horsetails, those of subgenus "Hippochaete" are often called scouring rushes, especially when unbranched. Two "Equisetum" plants are sold commercially under the names "Equisetum japonicum" (barred horsetail) and "Equisetum camtschatcense" (Kamchatka horsetail). These are both types of "E. hyemale" var. "hyemale", although they may also be listed as varieties of "E. hyemale". The genus "Equisetum" as a whole, while concentrated in the non-tropical northern hemisphere, is near-cosmopolitan, being absent only from Antarctica, though they are not known to


title: Equisetum content: be native to Australia, New Zealand nor the islands of the Pacific. They are most common in northern North America (Canada and the northernmost United States), where the genus is represented by nine species ("arvense", "fluviatile", "palustre", "pratense", "sylvaticum", "hyemale", "laevigatum", "scirpoides", and "variegatum"). Only four ("bogotense", "giganteum", "myriochaetum", and "ramosissimum") of the fifteen species are known to be native south of the Equator. They are perennial plants, herbaceous and dying back in winter as most temperate species, or evergreen as most tropical species and the temperate species rough horsetail ("E. hyemale"), branched horsetail ("E. ramosissimum"), dwarf horsetail ("E. scirpoides")


title: Equisetum content: and variegated horsetail ("E. variegatum"). They typically grow 0.2–1.5 m tall, though the "giant horsetails" are recorded to grow as high as 2.5 m (northern giant horsetail, "E. telmateia"), 5 m (southern giant horsetail, "E. giganteum") or 8 m (Mexican giant horsetail, "E. myriochaetum"), and allegedly even more. One species, "Equisetum fluviatile", is an emergent aquatic, rooted in water with shoots growing into the air. The stalks arise from rhizomes that are deep underground and difficult to dig out. The field horsetail ("E. arvense") can be a nuisance weed, readily regrowing from the rhizome after being pulled out. It is


title: Equisetum content: unaffected by many herbicides designed to kill seed plants. However, as "E. arvense" prefers an acid soil, lime may be used to assist in eradication efforts to bring the soil pH to 7 or 8. Members of the genus have been declared noxious weeds in Australia and in the US state of Oregon. All the "Equisetum" are classed as "unwanted organisms" in New Zealand and are listed on the National Pest Plant Accord. People have regularly consumed horsetails. The young plants are eaten cooked or raw, but considerable care must be taken. For example, the fertile stems bearing strobili of


title: Equisetum content: some species are cooked and eaten like asparagus (a dish called "tsukushi") in Japan. Native Americans in the Pacific Northwest eat the young shoots of this plant raw. If eaten over a long enough period of time, some species of horsetail can be poisonous to grazing animals, including horses. The toxicity appears to be due to thiaminase, which can cause thiamin (vitamin B1) deficiency. Extracts and other preparations of "E. arvense" have served as herbal remedies, with records dating over centuries. In 2009, the European Food Safety Authority concluded there was no evidence for the supposed health effects of "E.


title: Equisetum content: arvense", such as for invigoration, weight control, skincare, hair health or bone health. , there is insufficient scientific evidence for its effectiveness as a medicine to treat any human condition. "E. arvense" contains thiaminase, which metabolizes the B vitamin, thiamine, potentially causing thiamine deficiency and associated liver damage, if taken chronically. Horsetail might produce a diuretic effect. Further, its safety for oral consumption has not been sufficiently evaluated and it may be toxic, especially to children and pregnant women. Equisetum Equisetum (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of vascular plants that reproduce


title: Grapefruit content: Grapefruit The grapefruit ("Citrus" × "paradisi") is a subtropical citrus tree known for its sour to semi-sweet, somewhat bitter fruit. Grapefruit is a hybrid originating in Barbados as an accidental cross between two introduced species, sweet orange ("C. sinensis") and pomelo, or shaddock ("C. maxima"), both of which were introduced from Asia in the seventeenth century. When found, it was named the "forbidden fruit"; and frequently, it has been misidentified with the pomelo. The grapefruit's name alludes to clusters of the fruit on the tree, which often appear similar to that of grapes. The evergreen grapefruit trees usually grow to


title: Grapefruit content: around tall, although they may reach . The leaves are glossy, dark green, long (up to ), and thin. It produces white four-petaled flowers. The fruit is yellow-orange skinned and generally, an oblate spheroid in shape; it ranges in diameter from . The flesh is segmented and acidic, varying in color depending on the cultivars, which include white, pink, and red pulps of varying sweetness (generally, the redder varieties are the sweetest). The 1929 U.S. Ruby Red (of the Redblush variety) has the first grapefruit patent. The genetic origin of the grapefruit is a hybrid mix. One ancestor of the


title: Grapefruit content: grapefruit was the Jamaican sweet orange ("Citrus sinensis"), itself an ancient hybrid of Asian origin; the other was the Indonesian pomelo ("C. maxima"). One story of the fruit's origin is that a certain "Captain Shaddock" brought pomelo seeds to Jamaica and bred the first fruit, however, it probably originated as a naturally occurring hybrid between the two plants some time after they had been introduced there. The hybrid fruit, then called "the forbidden fruit", was first documented in 1750 by a Welshman, Rev. Griffith Hughes, who described specimens from Barbados in "The Natural History of Barbados". Currently, the grapefruit is


title: Grapefruit content: said to be one of the "Seven Wonders of Barbados". The grapefruit was brought to Florida by Count Odet Philippe in 1823 in what is now known as Safety Harbor. Further crosses have produced the tangelo (1905), the Minneola tangelo (1931), and the oroblanco (1984). The grapefruit was known as the "shaddock" or "shattuck" until the nineteenth century. Its current name alludes to clusters of the fruit on the tree, which often appear similar to that of grapes. Botanically, it was not distinguished from the pomelo until the 1830s, when it was given the name "Citrus paradisi." Its true origins


title: Grapefruit content: were not determined until the 1940s. This led to the official name being altered to "Citrus × paradisi," the "×" identifying its hybrid origin. An early pioneer in the American citrus industry was Kimball Atwood, a wealthy entrepreneur who founded the Atwood Grapefruit Company in the late nineteenth century. The Atwood Grove became the largest grapefruit grove in the world, with a yearly output of 80,000 boxes of fruit. It was there that pink grapefruit was first discovered in 1906. The 1929 Ruby Red patent was associated with real commercial success, which came after the discovery of a red grapefruit


title: Grapefruit content: growing on a pink variety. Using radiation to trigger mutations, new varieties were developed to retain the red tones which typically faded to pink. The Rio Red variety is the current (2007) Texas grapefruit with registered trademarks Rio Star and Ruby-Sweet, also sometimes promoted as "Reddest" and "Texas Choice". The Rio Red is a mutation bred variety that was developed by treatment of bud sticks with thermal neutrons. Its improved attributes of mutant variety are fruit and juice color, deeper red, and wide adaptation. The Star Ruby is the darkest of the red varieties. Developed from an irradiated Hudson grapefruit,


title: Grapefruit content: it has found limited commercial success because it is more difficult to grow than other varieties. The varieties of Texas and Florida grapefruit include: Oro Blanco, Ruby Red, Pink, Rio Star, Thompson, White Marsh, Flame, Star Ruby, Duncan, and Pummelo HB. China is the top producer of grapefruit and pomelo. It is followed by The United States and Mexico. Grapefruit comes in many varieties. One way to differentiate between varieties is by the flesh color of fruit they produce. The most popular varieties currently cultivated are red, white, and pink hues, referring to the internal pulp color of the fruit.


title: Grapefruit content: The family of flavors range from highly acidic and somewhat sour, to sweet and tart. Grapefruit mercaptan, a sulfur-containing terpene, is one of the substances which has a strong influence on the taste and odor of grapefruit, compared with other citrus fruits. Grapefruit and grapefruit juice have been found to interact with numerous drugs and in many cases, to result in adverse direct and/or side effects (if dosage is not carefully adjusted.) This happens in two very different ways. In the first, the effect is from bergamottin, a natural furanocoumarin in both grapefruit flesh and peel that inhibits the CYP3A4


title: Grapefruit content: enzyme, (among others from the P450 enzyme family responsible for metabolizing 90% of drugs). The action of the CYP3A4 enzyme itself is to metabolize many medications. If the drug's breakdown for removal is lessened, then the level of the drug in the blood may become too high or stay too long, leading to adverse effects. On the other hand, some drugs must be broken down to become active, and inhibiting CYP3A4 may lead to reduced drug effects. The other effect is that grapefruit can block the absorption of drugs in the intestine. If the drug is not absorbed, then not


title: Grapefruit content: enough of it is in the blood to have a therapeutic effect. Each affected drug has either a specific increase of effect or decrease. One whole grapefruit, or a glass of of grapefruit juice may cause drug overdose toxicity. Typically, drugs that are incompatible with grapefruit are so labeled on the container or package insert. People taking drugs should ask their health care provider or pharmacist questions about grapefruit and drug interactions. Grapefruit is a rich source of vitamin C (>20% of the Daily Value, DV in a 100 gram serving), contains the fiber pectin, and the pink and red


title: Grapefruit content: hues contain the beneficial antioxidant lycopene. Studies have shown grapefruit helps lower cholesterol, and there is evidence that the seeds have antioxidant properties. Grapefruit forms a core part of the "grapefruit diet", the theory being that the fruit's low glycemic index is able to help the body's metabolism burn fat. Although grapefruit seed extract (GSE) is promoted as a plant-based preservative by some natural personal care manufacturers, studies have shown that the apparent antimicrobial activity associated with GSE preparations is merely due to contamination with synthetic preservatives such as parabens. Citrus fruits show high amounts of putrescine, they contain very


title: Grapefruit content: little spermidine. Grapefruit juice contains about half the citric acid of lime or lemon juice (which contain about 47 g/l), and about two-and-a-half times the amount of citric acid found in orange juice. In Costa Rica, especially in Atenas, grapefruit are often cooked to remove their sourness, rendering them as sweets; they are also stuffed with "dulce de leche", resulting in a dessert called "toronja rellena" (stuffed grapefruit). In Haiti, grapefruit is used primarily for its juice ("jus de Chadèque"), but also is used to make jam ("confiture de Chadèque"). Grapefruit has also been investigated in cancer medicine pharmacodynamics. Its


title: Grapefruit content: inhibiting effect on the metabolism of some drugs may allow smaller doses to be used, which can help to reduce costs. Grapefruit is a pomelo backcross, a hybrid of pomelo × sweet orange, with sweet orange itself being a pomelo × mandarin hybrid. The grapefruit is a parent to many hybrids: The grapefruit's cousins include: Grapefruit The grapefruit ("Citrus" × "paradisi") is a subtropical citrus tree known for its sour to semi-sweet, somewhat bitter fruit. Grapefruit is a hybrid originating in Barbados as an accidental cross between two introduced species, sweet orange ("C. sinensis") and pomelo, or shaddock ("C. maxima"),


title: "Boeing 707" content: Boeing 707 The Boeing 707 is a mid-sized, long-range, narrow-body, four-engine jet airliner built by Boeing Commercial Airplanes from 1958 to 1979. Its name is commonly pronounced as "seven oh seven". Versions of the aircraft have a capacity from 140 to 219 passengers and a range of . Developed as Boeing's first jet airliner, the 707 is a swept-wing design with podded engines. Although it was not the first jetliner in service, the 707 was the first to be commercially successful. Dominating passenger air transport in the 1960s and remaining common through the 1970s, the 707 is generally credited with


title: "Boeing 707" content: ushering in the Jet Age. It established Boeing as one of the largest manufacturers of passenger aircraft, and led to the later series of airliners with "7x7" designations. The later 720, 727, 737, and 757 share elements of the 707's fuselage design. The 707 was developed from the Boeing 367-80, a prototype jet first flown in 1954. A larger fuselage cross-section and other modifications resulted in the initial-production 707-120, powered by Pratt & Whitney JT3C turbojet engines, which first flew on December 20, 1957. Pan American World Airways began regular 707 service on October 26, 1958. Later derivatives included the


title: "Boeing 707" content: shortened long-range 707-138 and the stretched 707-320, both of which entered service in 1959. A smaller short-range variant, the 720, was introduced in 1960. The 707-420, a version of the stretched 707 with Rolls-Royce Conway turbofans, debuted in 1960, while Pratt & Whitney JT3D turbofans debuted on the 707-120B and 707-320B models in 1961 and 1962, respectively. The 707 has been used on domestic, transcontinental, and transatlantic flights, and for cargo and military applications. A convertible passenger-freighter model, the 707-320C, entered service in 1963, and passenger 707s have been modified to freighter configurations. Military derivatives include the E-3 Sentry airborne


title: "Boeing 707" content: reconnaissance aircraft and the C-137 Stratoliner VIP transports. Boeing produced and delivered 1,011 airliners including the smaller 720 series; over 800 military versions were also produced. As of July 2017, there were no active 707s in commercial airline service. During and after World War II, Boeing was known for its military aircraft. The company had produced innovative and important bombers, from the B-17 Flying Fortress and B-29 Superfortress, to the jet-powered B-47 Stratojet and B-52 Stratofortress. The company's civil aviation department lagged far behind Douglas and other competitors, the only noteworthy airliners being the Boeing 314 Clipper and 307 Stratoliner.


title: "Boeing 707" content: During 1949–1950, Boeing embarked on studies for a new jet transport, realizing that any design must be aimed at both the military and civilian markets. At the time, aerial refueling was becoming a standard technique for military aircraft, with over 800 KC-97 Stratofreighters on order. With the advent of the Jet Age, a new tanker was required to meet the USAF's fleet of jet-powered bombers; this was where Boeing's new design would potentially win military orders. Boeing studied numerous wing and engine layouts for its new transport/tanker, some of which were based on the B-47 and C-97, before settling on


title: "Boeing 707" content: 367−80. The "Dash 80" took less than two years from project launch in 1952 to rollout on May 14, 1954, then first flew on July 15, 1954. It was powered by the Pratt & Whitney JT3C turbojet engine, which was the civilian version of the J57 used on many military aircraft of the day, including the F-100 Super Sabre fighter and the B-52 bomber. The prototype was a proof-of-concept aircraft for both military and civilian use. The United States Air Force was the first customer, using it as the basis for the KC-135 Stratotanker aerial refueling platform. Whether the passenger


title: "Boeing 707" content: 707 would be profitable was far from certain. At the time, Boeing was making nearly all of its money from military contracts: Its last passenger transport, the Boeing 377 Stratocruiser, had netted the company a $15 million loss before it was purchased by the Air Force as the KC-97 Stratofreighter. In a demonstration flight over Lake Washington outside Seattle, on August 7, 1955, test pilot Tex Johnston performed a barrel roll in the 367-80 prototype. The 132-inch (3.35 m) wide fuselage of the Dash 80 was large enough for four-abreast (two-plus-two) seating like the Stratocruiser. Answering customers' demands and under


title: "Boeing 707" content: Douglas competition, Boeing soon realized this would not provide a viable payload, so it widened the fuselage to to allow five-abreast seating and use of the KC-135's tooling. Douglas Aircraft had launched its DC-8 with a fuselage width of . The airlines liked the extra space and six-abreast seating, so Boeing increased the 707's width again to compete, this time to . The first flight of the first-production 707-120 took place on December 20, 1957, and FAA certification followed on September 18, 1958. Both test pilots Joseph John "Tym" Tymczyszyn and James R. Gannett were awarded the first Iven C.


title: "Boeing 707" content: Kincheloe Award for the test flights that led to certification. A number of changes were incorporated into the production models from the prototype. A Krueger flap was installed along the leading edge between the inner and outer engines on early 707-120 and −320 models. The initial standard model was the 707-120 with JT3C turbojet engines. Qantas ordered a shorter-bodied version called the 707-138, which was a −120 with six fuselage frames removed, three in front of the wings, and three aft. The frames in the 707 were each 20 in (500 mm) apart, so this resulted in a net shortening


title: "Boeing 707" content: of 10 ft (3 m) to . Because the maximum takeoff weight remained the same as that of the −120 (247,000 lb or 112 t), the −138 was able to fly the longer routes that Qantas needed. Braniff International Airways ordered the higher-thrust version with Pratt & Whitney JT4A engines, the 707-220. The final major derivative was the 707-320, which featured an extended-span wing and JT4A engines, while the 707-420 was the same as the −320, but with Conway turbofan engines. British certification requirements relating to go-arounds with one engine inoperative also forced Boeing to increase the height of the


title: "Boeing 707" content: tail fin on all 707 variants, as well as add a ventral fin, which was retrofitted on earlier −120 and −220 aircraft. These modifications also aided in the mitigation of Dutch roll by providing more stability in yaw. Though initially fitted with turbojet engines, the dominant engine for the Boeing 707 family was the Pratt & Whitney JT3D, a turbofan variant of the JT3C with lower fuel consumption and higher thrust. JT3D-engined 707s and 720s were denoted with a "B" suffix. While many 707-120Bs and -720Bs were conversions of existing JT3C-powered machines, 707-320Bs were available only as newly built aircraft,


title: "Boeing 707" content: as they had a stronger structure to support a maximum takeoff weight increased by , along with modifications to the wing. The 707-320B series enabled nonstop westbound flights from Europe to the US West Coast and from the US to Japan. The final 707 variant was the 707-320C, (C for "Convertible"), which had a large fuselage door for cargo. It had a revised wing with three-sectioned leading-edge flaps, improving takeoff and landing performance and allowing the ventral fin to be removed (although the taller fin was retained). The 707-320Bs built after 1963 used the same wing as the −320C and


title: "Boeing 707" content: were known as 707-320B Advanced aircraft. Production of the passenger 707 ended in 1978. In total, 1,010 707s were built for civilian use, though many of these found their way to military service. The 707 production line remained open for purpose-built military variants until 1991, with the last new-build 707 airframes built as E-3 and E-6 aircraft. Traces of the 707 are still found in the 737, which uses a modified version of the 707's fuselage, as well as the same external nose and cockpit configurations as those of the 707. These were also used on the previous 727, while


title: "Boeing 707" content: the 757 also used the 707 fuselage cross-section. The 707's wings are swept back at 35°, and like all swept-wing aircraft, display an undesirable "Dutch roll" flying characteristic that manifests itself as an alternating yawing and rolling motion. Boeing already had considerable experience with this on the B-47 and B-52, and had developed the yaw damper system on the B-47 that would be applied to later swept-wing configurations like the 707. However, many novice 707 pilots had no experience with this phenomenon, as they were transitioning from straight-wing propeller-driven aircraft such as the Douglas DC-7 and Lockheed Constellation. On one


title: "Boeing 707" content: customer-acceptance flight, where the yaw damper was turned off to familiarize the new pilots with flying techniques, a trainee pilot's actions violently exacerbated the Dutch roll motion and caused three of the four engines to be torn from the wings. The plane, a brand new 707-227, "N7071", destined for Braniff, crash-landed on a river bed north of Seattle at Arlington, Washington, killing four of the eight occupants. In his autobiography, test pilot Johnston describes a Dutch roll incident he experienced as a passenger on an early commercial 707 flight. As the aircraft's movements did not cease and most of the


title: "Boeing 707" content: passengers became ill, he suspected a misrigging of the directional autopilot (yaw damper). He went to the cockpit and found the crew unable to understand and resolve the situation. He introduced himself and relieved the ashen-faced captain who immediately left the cockpit feeling ill. Johnston disconnected the faulty autopilot and manually stabilized the plane "with two slight control movements". The 707 uses engine-driven turbocompressors to supply pressurized air for cabin pressurization. On many commercial 707s, the outer port (number 1) engine mount is distinctly different from the other three, as this engine is not fitted with a turbocompressor. Later-model 707s


title: "Boeing 707" content: typically had this configuration, although American Airlines had turbocompressors on engines 2 and 3 only. Early 707 models often had turbocompressor fairings on all four engines, but with only two or three compressors installed. The JT3D-3B engines are readily identifiable by the large gray secondary air inlet doors in the nose cowl. These doors are fully open (sucked in at the rear) during takeoff to provide additional air. When the engines are throttled back to cruise, the doors are shut. The 707 was the first commercial jet aircraft to be fitted with clamshell-type thrust reversers on each of the four


title: "Boeing 707" content: engines. Pratt & Whitney, in a joint venture with Seven Q Seven (SQS) and Omega Air, has selected the JT8D-219 as a re-engine powerplant for Boeing 707-based aircraft, calling their modified configuration a 707RE. Northrop Grumman has selected the −219 to re-engine the United States Air Force's fleet of 19 E-8 Joint STARS aircraft, which will allow the J-STARS more time on station due to the engine's greater fuel efficiency. NATO also plans to re-engine their fleet of E-3 Sentry AWACS aircraft. The −219 is publicized as being half the cost of the competing 707 re-engine powerplant, the CFM International


title: "Boeing 707" content: CFM56, and is 40 dB quieter than JT3D engines that are being replaced. The first commercial orders for the 707 came on October 13, 1955, when Pan Am committed to 20 707s and 25 Douglas DC-8s, dramatically increasing their passenger capacity (in available revenue passenger seat-miles per hour/per day) over its existing fleet of propeller aircraft. The competition between the 707 and Douglas DC-8 was fierce. Pan American ordered these planes, when and as they did, so that they would be the operators of the "first-off" production line for each aircraft type. Until their initial batch of the aircraft had


title: "Boeing 707" content: been delivered to them and put into operation, Pan American would have the distinction of being not only the "Launch Customer" for both transcontinental American jets, but the exclusive operator of American intercontinental jet transports for at least a year. The only rival in intercontinental jet aircraft production at the time was the British de Havilland Comet. However, this was never real competition for the American market as the Comet series had been the subject of fatal accidents (due to design flaws) early in its introduction, withdrawn from service, virtually redesigned from scratch, and reintroduced as version -4. It was


title: "Boeing 707" content: also smaller and slower than the 707. Several major airlines committed only to the (second place in the production race) Douglas DC-8. Douglas Aircraft was the more established and preferred (by airlines and their passengers) maker of passenger aircraft at the time. Douglas had correctly decided to await the validation of a larger and more fuel efficient engine (JT4A from Pratt & Whitney), and to design a larger and longer range aircraft around this engine. To stay competitive, Boeing made a late and costly decision to redesign and enlarge the 707's wing to help increase range and payload. The new


title: "Boeing 707" content: version was numbered 707-320. Pan Am was the first airline to operate the 707; the carrier inaugurated 707 service with a christening at National Airport on October 17, 1958, attended by President Eisenhower, followed by a transatlantic flight for VIPs (personal guests of founder Juan Trippe) from Baltimore's Friendship International Airport to Paris. The aircraft's first commercial flight was from Idlewild Airport, New York, to Le Bourget, Paris, on October 26, 1958, with a fuel stop in Gander, Newfoundland. In December, National Airlines operated the first U.S. domestic jet airline flights between New York/Idlewild and Miami, using 707s leased from