Taxonomy.

Polygonaceae are very well-defined and have long been universally recognized. In the APG III system, the family is placed in the order Caryophyllales. Within the order, it lies outside of the large clade known as the core Caryophyllales. It is sister to the family Plumbaginaceae, which it does not resemble morphologically. The last comprehensive revision of the family was published in 1993 by John Brandbyge as part of "The Families and Genera of Vascular Plants". Brandbyge followed earlier systems of plant classification in dividing Polygonaceae into two subfamilies, Eriogonoideae and Polygonoideae. Since 1993, the circumscriptions of these two subfamilies have been changed in light of phylogenetic studies of DNA sequences. Genera related to "Coccoloba" and "Triplaris" were moved from Polygonoideae to Eriogonoideae. The genus "Symmeria" does not belong to either of these subfamilies because it is sister to the rest of the family. "Afrobrunnichia" might constitute a new subfamily as well.  Brandbyge wrote descriptions for 43 genera of Polygonaceae in 1993. Since then, a few more genera have been erected, and some segregates of "Brunnichia", "Eriogonum", and "Persicaria" have been given generic status in major works. Some of the genera were found not to be monophyletic and their limits have been revised. These include "Ruprechtia", "Eriogonum", "Chorizanthe", "Persicaria", "Aconogonon", "Polygonum", "Fallopia", and "Muehlenbeckia".

Description.

Most Polygonaceae are perennial herbaceous plants with swollen nodes, but trees, shrubs and vines are also present. The leaves of Polygonaceae are simple, and arranged alternately on the stems. Each leaf has a peculiar pair of fused, sheathing stipules known as an ochrea. Those species that do not have the nodal ochrea can be identified by their possession of involucrate flower heads. The flowers are normally bisexual, small, and actinomorphic, with a perianth of three to six sepals. After flowering, the sepals often become thickened and enlarged around the developing fruit. Flowers lack a corolla and in some, the sepals are petal-like and colorful. The androecium is composed of three to eight stamens that are normally free or united at the base. The ovary consists of three united carpels that form a single locule, which produces only one ovule. The ovary is superior with basal or free-central placentation. The gynoecium terminates in 1 to 3 styles, each of which ends in a single stigma.

Genera.

, Plants of the World Online accepted 56 genera:

Phylogeny.

The following phylogenetic tree is based on two papers on the molecular phylogenetics of Polygonaceae.

The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is based on the genus "Polygonum", and was first used by Antoine Laurent de Jussieu in 1789 in his book, "Genera Plantarum". The name may refer to the many swollen nodes the stems of some species have, being derived from Greek, "poly" meaning'many' and "gony" meaning 'knee' or 'joint'. Alternatively, it may have a different derivation, meaning'many seeds'.


Etymology.

The name comes from the German "Kohl" ("cabbage") plus "Rübe" ~ "Rabi" (Swiss German variant) ("turnip"), because the swollen stem resembles the latter. Kohlrabi is a commonly eaten vegetable in German-speaking countries and American states with large ancestral German populations such as Wisconsin.  Its Group name Gongylodes (or lowercase and italicized "gongylodes" or "gongyloides" as a variety name) means "roundish" in Greek, from (, ‘round’).  In the northern part of Vietnam, it is called, and in eastern parts of India (West Bengal) and Bangladesh where it is called 'ol kopi'. It is also found in the Kashmir Valley in Northern India and is there known as'monj-hakh','monj' being the round part, and 'hakh' being the leafy part. It is called 'nol khol' in Northern India, 'navalkol' in Maharashtra, noolkol (நூல்கோல்) in Tamil, 'navilu kosu' in Karnataka and in Sri Lanka as 'nol col' (turnip cabbage). It is also native in Cyprus, where it is known as 'kouloumpra' (). It is eaten in the Czech Republic under name 'kedluben' or 'kedlubna'. In Slovakia, it is known as 'kaleráb'. In Romania, it is the 'gulie'.

Description.

Kohlrabi has been created by artificial selection for lateral meristem growth (a swollen, nearly spherical shape); its origin in nature is the same as that of cabbage, broccoli, cauliflower, kale, collard greens, and Brussels sprouts: they are all bred from, and are the same species as, the wild cabbage plant ("Brassica oleracea").  The taste and texture of kohlrabi are similar to those of a broccoli stem or cabbage heart, but milder and sweeter, with a higher ratio of flesh to skin. The young stem in particular can be as crisp and juicy as an apple, although much less sweet.  Except for the "Gigante" cultivar, spring-grown kohlrabi much over 5 cm in size tend to be woody, as do full-grown kohlrabi much over perhaps 10 cm in size; the Gigante cultivar can achieve great size while remaining of good eating quality. The plant matures in 55–60 days after sowing and has good standing ability for up to 30 days after maturity. The approximate weight is 150 g.  There are several varieties commonly available, including 'White Vienna', 'Purple Vienna', 'Grand Duke', 'Gigante' (also known as "Superschmelz"), 'Purple Danube', and 'White Danube'. Coloration of the purple types is superficial: the edible parts are all pale yellow. The leafy greens can also be eaten. One commonly used variety grows without a swollen stem, having just leaves and a very thin stem, and is called "Haakh". "Haakh" and "Monj" are popular Kashmiri dishes made using this vegetable. In the second year, the plant will bloom and develop seeds.

Preparation and use.

Kohlrabi stems (the enlarged vegetal part) are surrounded by two distinct fibrous layers that do not soften appreciably when cooked. These layers are generally peeled away prior to cooking or serving raw, with the result that the stems often provide a smaller amount of food than one might assume from their intact appearance.  The bulbous kohlrabi stem is frequently used raw in salad or slaws. It has a texture similar to that of a broccoli stem, but with a flavor that is sweeter and less vegetal.  Kohlrabi leaves are edible and can be used interchangeably with collard greens and kale.  Kohlrabi is an important part of the Kashmiri cuisine where it is called "Mŏnji" and is one of the most commonly cooked vegetable along with collard greens ("haakh"). It is prepared with its leaves and served with a light soup and eaten with rice.  In Cyprus it is popularly sprinkled with salt and lemon and served as an appetizer.  Some varieties are grown as feed for cattle.

Kohlrabi (from the German for cabbage turnip; "Brassica oleracea" Gongylodes Group), also called German turnip, is a biennial vegetable, a low, stout cultivar of wild cabbage. It is the same species as cabbage, broccoli, cauliflower, kale, Brussels sprouts, collard greens, Savoy cabbage, and gai lan.


Biography.

Lasswitz studied mathematics and physics at the University of Breslau and the University of Berlin, and earned his doctorate in 1873. He spent most of his career as a teacher at the Gymnasium Ernestinum in Gotha (1876–1908).

Works.

His first published science fiction story was "Bis zum Nullpunkt des Seins" ("To the Zero Point of Existence", 1871), depicting life in 2371, but he earned his reputation with his 1897 novel "Auf zwei Planeten", which describes an encounter between humans and a Martian civilization that is older and more advanced. The book has the Martian race running out of water, eating synthetic foods, travelling by rolling roads, and utilising space stations. His spaceships use anti-gravity, but travel realistic orbital trajectories, and use occasional mid-course corrections in travelling between Mars and the Earth; the book depicted the technically correct transit between the orbits of two planets, something poorly understood by other early science fiction writers. It influenced Walter Hohmann and Wernher von Braun. The book was not translated into English until 1971 (as "Two Planets"), and the translation is incomplete. "Auf zwei Planeten" was his most successful novel. A story from Lasswitz's "Traumkristalle" served as the basis for "The Library of Babel", a short story by Jorge Luis Borges.  His last book was "Sternentau: die Pflanze vom Neptunsmond" ("Star Dew: the Plant of Neptune's Moon", 1909). He is also known for his 1896 biography of Gustav Fechner.  For his writing (totalling around 420 works including non-fiction), Lasswitz has been called "the first utopistic-scientific writer in Germany" or even "a German Jules Verne".  A crater on Mars was named in his honour, as was the asteroid.  There also is a Kurd-Laßwitz-Preis, an award for German-speaking as well as foreign authors of science fiction since 1981.

Kurd Lasswitz (; 20 April 1848 – 17 October 1910) was a German author, scientist, and philosopher. He has been called "the father of German science fiction". He sometimes used the pseudonym "Velatus".


Genera.

The last revision of the entire family was published in 2004. It described and provided keys to 236 genera. These are marked with an asterisk (*) in the list below. A few genera have been established or resurrected since 2004. These are marked with a plus sign (+). The remaining genera in the list are mostly of historical interest only and are from a source that includes such genera without explanation. Few of these are recognized in modern treatments of the family.  Kew Gardens provides a list of genera that includes additional information. A list at the Angiosperm Phylogeny Website is frequently updated.

Recent changes.

The circumscription of several genera has changed since 2004. "Tsoongia", "Paravitex", and "Viticipremna" have been sunk into synonymy with "Vitex". "Huxleya" has been sunk into "Volkameria". "Kalaharia", "Volkameria", "Ovieda", and "Tetraclea" have been segregated from a formerly polyphyletic "Clerodendrum". "Rydingia" has been separated from "Leucas". The remaining "Leucas" is paraphyletic over four other genera.

Subfamilies and tribes.

In 2004, the Lamiaceae were divided into seven subfamilies with 10 genera not placed in any of the subfamilies. The unplaced genera are: "Tectona", "Callicarpa", "Hymenopyramis", "Petraeovitex", "Peronema", "Garrettia", "Cymaria", "Acrymia", "Holocheila", and "Ombrocharis". The subfamilies are the Symphorematoideae, Viticoideae, Ajugoideae, Prostantheroideae, Nepetoideae, Scutellarioideae, and Lamioideae. The subfamily Viticoideae is probably not monophyletic. The Prostantheroideae and Nepetoideae are divided into tribes. These are shown in the phylogenetic tree below.

Phylogeny.

Most of the genera of Lamiaceae have never been sampled for DNA for molecular phylogenetic studies. Most of those that have been are included in the following phylogenetic tree. The phylogeny depicted below is based on seven different sources.

The Lamiaceae ( ) or Labiatae are a family of flowering plants commonly known as the mint or deadnettle or sage family. Many of the plants are aromatic in all parts and include widely used culinary herbs like basil, mentha, rosemary, sage, savory, marjoram, oregano, hyssop, thyme, lavender, and perilla. Some species are shrubs, trees (such as teak), or, rarely, vines. Many members of the family are widely cultivated, not only for their aromatic qualities, but also their ease of cultivation, since they are readily propagated by stem cuttings. Besides those grown for their edible leaves, some are grown for decorative foliage, such as "Coleus". Others are grown for seed, such as "Salvia hispanica" (chia), or for their edible tubers, such as "Plectranthus edulis", "Plectranthus esculentus", "Plectranthus rotundifolius", and "Stachys affinis" (Chinese artichoke).


Structure.

The complexity of an integrated circuit is bounded by physical limitations on the number of transistors that can be put onto one chip, the number of package terminations that can connect the processor to other parts of the system, the number of interconnections it is possible to make on the chip, and the heat that the chip can dissipate. Advancing technology makes more complex and powerful chips feasible to manufacture.  A minimal hypothetical microprocessor might include only an arithmetic logic unit (ALU), and a control logic section. The ALU performs addition, subtraction, and operations such as AND or OR. Each operation of the ALU sets one or more flags in a status register, which indicate the results of the last operation (zero value, negative number, overflow, or others). The control logic retrieves instruction codes from memory and initiates the sequence of operations required for the ALU to carry out the instruction. A single operation code might affect many individual data paths, registers, and other elements of the processor.  As integrated circuit technology advanced, it was feasible to manufacture more and more complex processors on a single chip. The size of data objects became larger; allowing more transistors on a chip allowed word sizes to increase from 4- and 8-bit words up to today's 64-bit words. Additional features were added to the processor architecture; more on-chip registers sped up programs, and complex instructions could be used to make more compact programs. Floating-point arithmetic, for example, was often not available on 8-bit microprocessors, but had to be carried out in software. Integration of the floating point unit first as a separate integrated circuit and then as part of the same microprocessor chip sped up floating point calculations.  Occasionally, physical limitations of integrated circuits made such practices as a bit slice approach necessary. Instead of processing all of a long word on one integrated circuit, multiple circuits in parallel processed subsets of each data word. While this required extra logic to handle, for example, carry and overflow within each slice, the result was a system that could handle, for example, 32-bit words using integrated circuits with a capacity for only four bits each.  The ability to put large numbers of transistors on one chip makes it feasible to integrate memory on the same die as the processor. This CPU cache has the advantage of faster access than off-chip memory and increases the processing speed of the system for many applications. Processor clock frequency has increased more rapidly than external memory speed, so cache memory is necessary if the processor is not to be delayed by slower external memory.

Embedded applications.

Thousands of items that were traditionally not computer-related include microprocessors. These include large and small household appliances, cars (and their accessory equipment units), car keys, tools and test instruments, toys, light switches/dimmers and electrical circuit breakers, smoke alarms, battery packs, and hi-fi audio/visual components (from DVD players to phonograph turntables). Such products as cellular telephones, DVD video system and HDTV broadcast systems fundamentally require consumer devices with powerful, low-cost, microprocessors. Increasingly stringent pollution control standards effectively require automobile manufacturers to use microprocessor engine management systems to allow optimal control

History.

The advent of low-cost computers on integrated circuits has transformed modern society. General-purpose microprocessors in personal computers are used for computation, text editing, multimedia display, and communication over the Internet. Many more microprocessors are part of embedded systems, providing digital control over myriad objects from appliances to automobiles to cellular phones and industrial process control. Microprocessors perform binary operations based on Boolean Logic, named after George Boole. The ability to operate computer systems using Boolean Logic was first proven in a 1938 Thesis by Masters Student Claude Shannon, who later went on to become a Professor. Shannon is considered "The Father of Information Theory".  The microprocessor has origins in the development of the MOSFET (metal-oxide-semiconductor field-effect transistor, or MOS transistor), which was first demonstrated by Mohamed M. Atalla and Dawon Kahng of Bell Labs in 1960. Following the development of MOS integrated circuit chips in the early 1960s, MOS chips reached higher transistor density and lower manufacturing costs than bipolar integrated circuits by 1964. MOS chips further increased in complexity at a rate predicted by Moore's law, leading to large-scale integration (LSI) with hundreds of transistors on a single MOS chip by the late 1960s. The application of MOS LSI chips to computing was the basis for the first microprocessors, as engineers began recognizing that a complete computer processor could be contained on several MOS LSI chips. Designers in the late 1960s were striving to integrate the central processing unit (CPU) functions of a computer onto a handful of MOS LSI chips, called microprocessor unit (MPU) chipsets.  The first true microprocessor was the Intel 4004, released as a single MOS LSI chip in 1971. The single-chip microprocessor was made possible with the development of MOS silicon-gate technology (SGT). The earliest MOS transistors had aluminium metal gates, which Italian engineer Federico Faggin replaced with silicon self-aligned gates to develop the first silicon-gate MOS chip at Fairchild Semiconductor in 1968. Faggin later joined Intel and used his silicon-gate MOS technology to develop the 4004, along with Marcian Hoff, Stanley Mazor and Masatoshi Shima in 1971. The 4004 was designed for Busicom, which had earlier proposed a multi-chip design in 1969, before Faggin's team at Intel changed it into a new single-chip design. Intel introduced the first commercial microprocessor, the 4-bit Intel 4004, in 1971. It was soon followed by the 8-bit microprocessor Intel 8008 in 1972.  Other embedded uses of 4-bit and 8-bit microprocessors, such as terminals, printers, various kinds of automation etc., followed soon after. Affordable 8-bit microprocessors with 16-bit addressing also led to the first general-purpose microcomputers from the mid-1970s on.  The first use of the term "microprocessor" is attributed to Viatron Computer Systems describing the custom integrated circuit used in their System 21 small computer system announced in 1968.  Since the early 1970s, the increase in capacity of microprocessors has followed Moore's law; this originally suggested that the number of components that can be fitted onto a chip doubles every year. With present technology, it is actually every two years, and as a result Moore later changed the period to two years.

Market statistics.

In 1997, about 55% of all CPUs sold in the world were 8-bit microcontrollers, of which over 2 billion were sold.  In 2002, less than 10% of all the CPUs sold in the world were 32-bit or more. Of all the 32-bit CPUs sold, about 2% are used in desktop or laptop personal computers. Most microprocessors are used in embedded control applications such as household appliances, automobiles, and computer peripherals. Taken as a whole, the average price for a microprocessor, microcontroller, or DSP is just over.  In 2003, about $44 billion (equivalent to about $ billion in ) worth of microprocessors were manufactured and sold. Although about half of that money was spent on CPUs used in desktop or laptop personal computers, those count for only about 2% of all CPUs sold. The quality-adjusted price of laptop microprocessors improved −25% to −35% per year in 2004–2010, and the rate of improvement slowed to −15% to −25% per year in 2010–2013.  About 10 billion CPUs were manufactured in 2008. Most new CPUs produced each year are embedded.

A microprocessor is a computer processor that incorporates the functions of a central processing unit on a single (or more) integrated circuit (IC) of MOSFET construction. The microprocessor is a multipurpose, clock driven, register based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential digital logic. Microprocessors operate on numbers and symbols represented in the binary number system.


Lists and editions.

The first edition of 1771 covered 45 objects numbered M1 to M45. The total list published by Messier in 1781 contained 103 objects, but the list was expanded through successive additions by other astronomers, motivated by notes in Messier's and Méchain's texts indicating that at least one of them knew of the additional objects. The first such addition came from Nicolas Camille Flammarion in 1921, who added Messier 104 after finding a note Messier made in a copy of the 1781 edition of the catalogue. M105 to M107 were added by Helen Sawyer Hogg in 1947, M108 and M109 by Owen Gingerich in 1960, and M110 by Kenneth Glyn Jones in 1967. M102 was observed by Méchain, who communicated his notes to Messier. Méchain later concluded that this object was simply a re-observation of M101, though some sources suggest that the object Méchain observed was the galaxy NGC 5866 and identify that as M102.  Messier's final catalogue was included in the "Connaissance des Temps pour l'Année 1784" ("Knowledge of Time"; published in 1781), the French official yearly publication of astronomical ephemerides.  Messier lived and did his astronomical work at the Hôtel de Cluny (now the Musée national du Moyen Âge), in Paris, France. The list he compiled contains only objects found in the sky area he could observe: from the north celestial pole to a celestial latitude of about −35.7°. He did not observe or list objects visible only from farther south, such as the Large and Small Magellanic Clouds.

Observations.

The Messier catalogue comprises nearly all the most spectacular examples of the five types of deep-sky object – diffuse nebulae, planetary nebulae, open clusters, globular clusters, and galaxies – visible from European latitudes. Furthermore, almost all of the Messier objects are among the closest to Earth in their respective classes, which makes them heavily studied with professional class instruments that today can resolve very small and visually spectacular details in them. A summary of the astrophysics of each Messier object can be found in the "Concise Catalog of Deep-sky Objects."  Since these objects could be observed visually with the relatively small-aperture refracting telescope (approximately 100 mm, or 4 inches) used by Messier to study the sky, they are among the brightest and thus most attractive astronomical objects (popularly called deep-sky objects) observable from Earth, and are popular targets for visual study and astrophotography available to modern amateur astronomers using larger aperture equipment. In early spring, astronomers sometimes gather for "Messier marathons", when all of the objects can be viewed over a single night.

Star chart of Messier objects.

NOTE: Messier 102 is missing from this chart.

The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his "Catalogue des Nébuleuses et des Amas d'Étoiles" ("Catalogue of Nebulae and Star Clusters"). Because Messier was only interested in finding comets, he created a list of non-comet objects that frustrated his hunt for them. The compilation of this list, in collaboration with his assistant Pierre Méchain, is known as "the Messier catalogue." This catalogue of objects is one of the most famous lists of astronomical objects, and many Messier objects are still referenced by their Messier number. The catalogue includes astronomical objects (deep-sky objects) that can be observed from Earth's Northern Hemisphere; many Messier objects are extremely popular targets for amateur astronomers.


Morphology.

Mites are arachnids, and as such, evolved from a segmented body with the segments organised into two tagmata: a prosoma (cephalothorax) and an opisthosoma (abdomen). However, only the faintest traces of primary segmentation remain in mites; the prosoma and opisthosoma are fused, and a region of flexible cuticle (the circumcapitular furrow) separates the chelicerae and pedipalps from the rest of the body. This anterior body region is called the capitulum or gnathosoma, and according to some works, is also found in the Ricinulei. The remainder of the body is called the idiosoma and is unique to mites.  Most adult mites have four pairs of legs, like other arachnids, but some have fewer. For example, gall mites like "Phyllocoptes variabilis" (family Eriophyidae) have a worm-like body with only two pairs of legs; some parasitic mites have only one or three pairs of legs in the adult stage. Larval and prelarval stages have a maximum of three pairs of legs; adult mites with only three pairs of legs may be called 'larviform'. Also, members of the Nematalycidae within the Endeostigmata, which live between sand grains, have often worm-like and elongated bodies with reduced legs.  The mouth parts of mites may be adapted for biting, stinging, sawing, or sucking. They breathe through tracheae, stigmata (small openings of the skin), intestines, and the skin itself. Species hunting for other mites have very acute senses, but many mites are eyeless. The central eyes of arachnids are always missing, or they are fused into a single eye. Thus, any eye number from none to five may occur.

Ontogeny.

Acarine ontogeny typically consists of an egg, a prelarval stage (often absent), a larval stage (hexapod except in the mite superfamily Eriophyoidea, which have only two pairs of legs), and a series of nymphal stages. Any or all of these stages except the adult may be suppressed or occur only within the body of a previous stage. Larvae (and prelarvae) have a maximum of three pairs of legs (legs are often reduced to stubs or absent in prelarvae); legs IV are added at the first nymphal stage. Usually, a maximum of three nymphal stages are present and they are referred to in sequence as the protonymph, deutonymph, and tritonymph; however, some soft ticks have supernumerary nymphal stages. The females of some Tarsonemidae bear sexually mature young. If any nymphal stages are absent, then authors may disagree on which stages are present. Only the Oribatida pass through all developmental stages.

Diversity and lifestyles.

Acarines are extremely diverse. They live in practically every habitat, and include aquatic (fresh and sea water) and terrestrial species. They outnumber other arthropods in the soil organic matter and detritus. Many are parasitic, and they affect both vertebrates and invertebrates. Most parasitic forms are external parasites, while the free-living forms are generally predatory and may even be used to control undesirable arthropods. Others are detritivores that help to break down forest litter and dead organic matter, such as skin cells. Others still are plant feeders and may damage crops.  The feather mites, Astigmata, are found on almost all species of birds, except for penguins, and are highly specialized for life on their hosts. They may feed on uropygial oil, skin flakes, fungus, bacteria, and feathers, depending on the taxon to which they belong. Their lifestyles are affected by the microclimate (ambient temperature and relative humidity); for example, seasonal change in temperature causes feather mites to shift their microhabitats on blue tits. However, no evidence shows microclimate affecting mite diversity.

Economic and medical importance.

Damage to crops is perhaps the most costly economic effect of mites, especially by the spider mites and their relatives (Tetranychoidea), earth mites (Penthaleidae), thread-footed mites (Tarsonemidae) and the gall and rust mites (Eriophyidae). The honey bee parasite "Varroa destructor" has caused or contributed to large-scale die-offs of commercial pollinating populations.  Some parasitic forms affect humans and other mammals, causing damage by their feeding, and can even be vectors of diseases, such as scrub typhus, rickettsialpox, Lyme disease, Q fever, Colorado tick fever, tularemia, tick-borne relapsing fever, babesiosis, ehrlichiosis, and tick-borne meningoencephalitis. A well-known effect of mites on humans is their role as allergens and the stimulation of asthma in people affected by respiratory disease.  The use of predatory mites (for example, Phytoseiidae) in pest control and herbivorous mites that infest weeds are also of importance. An unquantified, but major positive contribution of the Acari is their normal functioning in ecosystems, especially their roles in the decomposer subsystem. In this context, the association of many species with carcasses and decaying organic matter qualify them as potential medicolegal indicators in forensic entomology.  Chemical agents used to control ticks and mites include dusting sulfur and ivermectin.

Taxonomy and phylogeny.

The phylogeny of the Acari is still disputed and several taxonomic schemes have been proposed for their classification. The third edition (2009) of the standard textbook "A Manual of Acarology" uses a system of six orders, grouped into three superorders:  Recent genetic research has caused a change in the naming scheme, however, and recent publications have changed the superorder Parasitiformes to an order. Other recent research has suggested that Acari is polyphyletic, with ticks and spiders being more closely related than ticks and mites. The cladogram is based on Dabert et al. 2010, which used molecular data. It showed the Acariformes sister to the Solifugae (camel spiders), while the Parasitiformes were sister to the Pseudoscorpionida.

The Acari (or Acarina ) are a taxon of arachnids that contains mites and ticks. The diversity of the Acari is extraordinary and their fossil history goes back to at least the early Devonian period. Acarologists (people who study the Acari) have proposed a complex set of taxonomic ranks to classify mites. In most modern treatments, the Acari are considered a subclass of the Arachnida and are composed of two or three superorders or orders: Acariformes (or Actinotrichida), Parasitiformes (or Anactinotrichida), and Opilioacariformes; the latter is often considered a subgroup within the Parasitiformes. The monophyly of the Acari is open to debate, and the relationships of the acarines to other arachnids is not at all clear. In older treatments, the subgroups of the Acarina were placed at order rank, but as their own subdivisions have become better understood, treating them at the superorder rank is more usual.


Instruction set.

Every processor or processor family has its own instruction set. Instructions are patterns of bits, digits or characters that by physical design correspond to different commands to the machine. Thus, the instruction set is specific to a class of processors using (mostly) the same architecture. Successor or derivative processor designs often include all the instructions of a predecessor and may add additional instructions. Occasionally, a successor design will discontinue or alter the meaning of some instruction code (typically because it is needed for new purposes), affecting code compatibility to some extent; even nearly completely compatible processors may show slightly different behavior for some instructions, but this is rarely a problem. Systems may also differ in other details, such as memory arrangement, operating systems, or peripheral devices. Because a program normally relies on such factors, different systems will typically not run the same machine code, even when the same type of processor is used.  A processor's instruction set may have all instructions of the same length, or it may have variable-length instructions. How the patterns are organized varies strongly with the particular architecture and often also with the type of instruction. Most instructions have one or more opcode fields which specifies the basic instruction type (such as arithmetic, logical, jump, etc.) and the actual operation (such as add or compare) and other fields that may give the type of the operand(s), the addressing mode(s), the addressing offset(s) or index, or the actual value itself (such constant operands contained in an instruction are called "immediates").  Not all machines or individual instructions have explicit operands. An accumulator machine has a combined left operand and result in an implicit accumulator for most arithmetic instructions. Other architectures (such as 8086 and the x86-family) have accumulator versions of common instructions, with the accumulator regarded as one of the general registers by longer instructions. A stack machine has most or all of its operands on an implicit stack. Special purpose instructions also often lack explicit operands (CPUID in the x86 architecture writes values into four implicit destination registers, for instance). This distinction between explicit and implicit operands is important in code generators, especially in the register allocation and live range tracking parts. A good code optimizer can track implicit as well as explicit operands which may allow more frequent constant propagation, constant folding of registers (a register assigned the result of a constant expression freed up by replacing it by that constant) and other code enhancements.

Programs.

A computer program is a list of instructions that can be executed by a central processing unit (CPU). A program's execution is done in order for the CPU that is executing it to solve a specific problem and thus accomplish a specific result. While simple processors are able to execute instructions one after another, superscalar processors are capable of executing a variety of different instructions at once.  Program flow may be influenced by special 'jump' instructions that transfer execution to an instruction other than the numerically following one. Conditional jumps are taken (execution continues at another address) or not (execution continues at the next instruction) depending on some condition.

Assembly languages.

A much more readable rendition of machine language, called assembly language, uses mnemonic codes to refer to machine code instructions, rather than using the instructions' numeric values directly, and uses symbolic names to refer to storage locations and sometimes registers. For example, on the Zilog Z80 processor, the machine code codice_1, which causes the CPU to decrement the codice_2 processor register, would be represented in assembly language as codice_3.

Example.

The MIPS architecture provides a specific example for a machine code whose instructions are always 32 bits long. The general type of instruction is given by the "op" (operation) field, the highest 6 bits. J-type (jump) and I-type (immediate) instructions are fully specified by "op". R-type (register) instructions include an additional field "funct" to determine the exact operation. The fields used in these types are:  "rs", "rt", and "rd" indicate register operands; "shamt" gives a shift amount; and the "address" or "immediate" fields contain an operand directly.  For example, adding the registers 1 and 2 and placing the result in register 6 is encoded:  Load a value into register 8, taken from the memory cell 68 cells after the location listed in register 3:  Jumping to the address 1024:

Relationship to microcode.

In some computer architectures, the machine code is implemented by an even more fundamental underlying layer called microcode, providing a common machine language interface across a line or family of different models of computer with widely different underlying dataflows. This is done to facilitate porting of machine language programs between different models. An example of this use is the IBM System/360 family of computers and their successors. With dataflow path widths of 8 bits to 64 bits and beyond, they nevertheless present a common architecture at the machine language level across the entire line.  Using microcode to implement an emulator enables the computer to present the architecture of an entirely different computer. The System/360 line used this to allow porting programs from earlier IBM machines to the new family of computers, e.g. an IBM 1401/1440/1460 emulator on the IBM S/360 model 40.

Relationship to bytecode.

Machine code is generally different from bytecode (also known as p-code), which is either executed by an interpreter or itself compiled into machine code for faster (direct) execution. An exception is when a processor is designed to use a particular bytecode directly as its machine code, such as is the case with Java processors.  Machine code and assembly code are sometimes called "native code" when referring to platform-dependent parts of language features or libraries.

Storing in memory.

The Harvard architecture is a computer architecture with physically separate storage and signal pathways for the code (instructions) and data. Today, most processors implement such separate signal pathways for performance reasons but implement a Modified Harvard architecture, so they can support tasks like loading an executable program from disk storage as data and then executing it. Harvard architecture is contrasted to the Von Neumann architecture, where data and code are stored in the same memory which is read by the processor allowing the computer to execute commands.  From the point of view of a process, the "code space" is the part of its address space where the code in execution is stored. In multitasking systems this comprises the program's code segment and usually shared libraries. In multi-threading environment, different threads of one process share code space along with data space, which reduces the overhead of context switching considerably as compared to process switching.

Readability by humans.

Pamela Samuelson wrote that machine code is so unreadable that the United States Copyright Office cannot identify whether a particular encoded program is an original work of authorship; however, the US Copyright Office "does" allow for copyright registration of computer programs and a program's machine code can sometimes be decompiled in order to make its functioning more easily understandable to humans.  Cognitive science professor Douglas Hofstadter has compared machine code to genetic code, saying that "Looking at a program written in machine language is vaguely comparable to looking at a DNA molecule atom by atom."

Machine code is a computer program written in machine language instructions that can be executed directly by a computer's central processing unit (CPU). Each instruction causes the CPU to perform a very specific task, such as a load, a store, a jump, or an arithmetic logic unit (ALU) operation on one or more units of data in the CPU's registers or memory.


Taxonomy and nomenclature.

The circumscription of the Malvaceae is controversial. The traditional Malvaceae "sensu stricto" comprise a very homogeneous and cladistically monophyletic group. Another major circumscription, Malvaceae "sensu lato", has been more recently defined on the basis that molecular techniques have shown the commonly recognised families Bombacaceae, Tiliaceae, and Sterculiaceae, which have always been considered closely allied to Malvaceae "s.s.", are not monophyletic groups. Thus, the Malvaceae can be expanded to include all of these families so as to compose a monophyletic group. Adopting this circumscription, the Malvaceae incorporate a much larger number of genera.

Subfamilies.

This article is based on the second circumscription, as presented by the Angiosperm Phylogeny Website. The Malvaceae "s.l." (hereafter simply "Malvaceae") comprise nine subfamilies. A tentative cladogram of the family is shown below. The diamond denotes a poorly supported branching (<80%).  It is important to point out the relationships between these subfamilies are still either poorly supported or almost completely obscure. There are continuing disagreements over the correct circumscription of these subfamilies, including the preservation of the family, Bombacaceae. The circumscription of the family may change dramatically as new studies are published.  If looking for information about the traditional Malvaceae "s.s.", we recommend referring to Malvoideae, the subfamily that approximately corresponds to that group.

Synapomorphies.

The relationships between the "core Malvales" families used to be defined on the basis of shared "malvean affinities". These included the presence of malvoid teeth, stems with mucilage canals, and stratified wedge-shaped phloem. These affinities were problematic because they were not always shared within the core families. Later studies revealed more unambiguous synapomorphies within Malvaceae "s.l.." Synapomorphies identified within Malvaceae "s.l." include the presence of tile cells, trichomatous nectaries, and an inflorescence structure called a bicolor unit. Tile cells consist of vertically positioned cells interspersed between and dimensionally similar to procumbent ray cells. Evidence of Malvean wood fossils have confirmed their evolutionary link in Malvaceae "s.l.", as well explained their diverse structures. Flowers of Malvaceae "s.l". exhibit nectaries consisting of densely arranged multicellular hairs resembling trichomes. In most of Malvaceae "s.l.", these trichomatous nectaries are located on the inner surface of the sepals, but flowers of the subfamily, Tiliodeae, also have present nectaries on the petals. Malvean flowers also share a unifying structure known as a bicolor unit, named for its initial discovery in the flowers of "Theobroma bicolor". The bicolor unit consists of an ordered inflorescence with determinate cymose structures. The inflorescence can branch off the main axis, creating separate orders of the flowers, with the main axis developing first. Bracts on the peduncle subtend axillary buds that become these lateral stalks. One bract within this whorl is a sterile bract. The bicolor unit is a variable structure in complexity, but the presence of fertile and sterile bracts is a salient character.

Names.

The English common name'mallow' (also applied to other members of Malvaceae) comes from Latin "malva" (also the source for the English word "mauve"). "Malva" itself was ultimately derived from the word for the plant in ancient Mediterranean languages. Cognates of the word include Ancient Greek () or (), Modern Greek (), modern () and modern ().

Description.

Most species are herbs or shrubs, but some are trees and lianas.

Leaves and stems.

Leaves are generally alternate, often palmately lobed or compound and palmately veined. The margin may be entire, but when dentate, a vein ends at the tip of each tooth (malvoid teeth). Stipules are present. The stems contain mucous canals and often also mucous cavities. Hairs are common, and are most typically stellate. Stems of Bombacoideae are often covered in thick prickles.

Flowers.

The flowers are commonly borne in definite or indefinite axillary inflorescences, which are often reduced to a single flower, but may also be cauliflorous, oppositifolious, or terminal. They often bear supernumerary bracts in the structure of a bicolor unit. They can be unisexual or bisexual, and are generally actinomorphic, often associated with conspicuous bracts, forming an epicalyx. They generally have five valvate sepals, most frequently basally connate, with five imbricate petals. The stamens are five to numerous, and connate at least at their bases, but often forming a tube around the pistils. The pistils are composed of two to many connate carpels. The ovary is superior, with axial placentation, with capitate or lobed stigma. The flowers have nectaries made of many tightly packed glandular hairs, usually positioned on the sepals.

Fruits.

The fruits are most often loculicidal capsules, schizocarps or nuts.

Pollination.

Self-pollination is often avoided by means of protandry. Most species are entomophilous (pollinated by insects). Bees from the tribe Emphorini of the Apidae (including "Ptilothrix", "Diadasia", and "Melitoma") are known to specialize on the plants.

Importance.

A number of species are pests in agriculture, including "Abutilon theophrasti" and "Modiola caroliniana", and others that are garden escapes. Cotton (four species of "Gossypium"), kenaf ("Hibiscus cannabinus"), cacao ("Theobroma cacao"), kola nut ("Cola spp."), and okra ("Abelmoschus esculentus") are important agricultural crops. The fruit and leaves of baobabs are edible, as is the fruit of the durian. A number of species, including "Hibiscus syriacus", "Hibiscus rosa-sinensis" and "Alcea rosea" are garden plants.

Malvaceae, or the mallows, is a family of flowering plants estimated to contain 244 genera with 4225 known species. Well-known members of economic importance include okra, cotton, cacao and durian. There are also some genera containing familiar ornamentals, such as "Alcea" (hollyhock), "Malva" (mallow) and "Lavatera" (tree mallow), as well as "Tilia" (lime or linden tree). The largest genera in terms of number of species include "Hibiscus" (300 species), "Sterculia" (250 species), "Dombeya" (250 species), "Pavonia" (200 species) and "Sida" (200 species).


Life and work.

Born in Hamburg, he is the son of Achim Helge Freiherr von Beust and Hanna, née Wolff, who was considered half Jewish in Nazi Germany. Through his father he is a descendant of Saxon and Austrian statesman Count Friedrich Ferdinand von Beust.  In 1971 von Beust became a member of the conservative Christian Democratic Union (CDU). In 1973, after finishing high school, he worked for CDU parliamentary group in the Hamburg Parliament ("Hamburgische Bürgerschaft"), a position he held until he started to study law in 1975 at the University of Hamburg. From 1977 until 1983 he was Hamburg president of the youth organisation of his party. Since 1978 Beust has been a member of the Hamburg city-state's parliament. In 1983 he successfully completed his studies and became an independent lawyer.  He has been a member of the ruling council of the Hamburg Land CDU since 1992, and of the national ruling council of the CDU party since 1998.

First Mayor of Hamburg.

First term  On 31 October 2001, Ole von Beust became First Mayor of Hamburg.  When Hamburg experienced an exodus of jobs after major corporations including cigarette-maker Reemtsma, travel and shipping company Hapag-Lloyd, haircare products-maker Hans Schwarzkopf and the Vereins and Westbank AG were acquired by companies outside of Hamburg, von Beust had the city's investment arm, the Hamburger Gesellschaft für Beteiligungsverwaltung, join forces with retailer Tchibo for the acquisition of cosmetics maker Beiersdorf in 2003. This put American multinational Procter & Gamble out of the bidding and preserved Beiersdorf as a publicly traded, stand-alone company in Hamburg.  As host of Hamburg's annual St. Matthew's Day banquet for the city's civic and business leaders, von Beust invited several high-ranking guests of honour to the city, including Queen Silvia of Sweden (2003), King Abdullah II of Jordan (2005), Crown Prince Frederik of Denmark (2006), President Jakaya Kikwete of Tanzania (2008).  On 19 August 2003, von Beust dismissed his vice-mayor, Ronald Schill, causing a scandal. Von Beust had earlier dismissed Walter Wellinghausen, senator of the interior and Schill's most important official, without consulting Schill beforehand. This was due to public allegations of misconduct on Wellinghausen's part. In a private conversation, Schill then demanded that Beust take back the dismissal, allegedly using personal threats. Beust then decided to dismiss Schill as well.  In the (preassigned) press conference Schill held minutes after he had heard of his own dismissal, he spoke vaguely of "homosexual relationships", a "flat in an infamous hustler district" and "certain things happened that let one infer the occurrence of love acts" between von Beust and Roger Kusch, who von Beust had appointed minister (in German city-states "senator") of justice. Beust in turn stated that Schill threatened to make his alleged liaison with Kusch public under the premise that Beust intermingled public and private affairs. He said he had no sexual relationship with Kusch, that they merely knew each other for 25 years and were good friends, and that Beust was Kusch's landlord. "This is all – absolutely all", according to Beust.  His unprepared statement to the press quickly earned Schill a homophobic reputation. A popular radio-station broadcast a song calling him "Mega-Proll" (mega redneck) and gay and lesbian associations protested vocally. Schill however later affirmed von Beust's version of the story, except for the accusations of blackmail, saying that he warned von Beust to stay clear of nepotism, and that this had nothing to do with Beust's sexual orientation. He stated "I have nothing against homosexuals".  In a later interview, von Beust's father confirmed that his son is indeed homosexual. Beust himself considers his sexual orientation a private matter; when asked directly he usually ironically refers the interviewer to his father. He has been in a relationship with his partner Lukas Förster since 2013.  Second term  The Hamburg elections of 29 February 2004, ended with an unprecedented landslide victory for Ole von Beust and the CDU, with the party achieving an overall majority in the city-state's parliament. The CDU gained 47.2 percent of the vote, a full 21-point increase from the previous election in September 2001. This was the first time since 1993 the city-state has had only a single ruling party.  Under von Beust's leadership, the Hamburg state government made the decision to commence construction of the Elbphilharmonie, a concert hall in the quarter.  Between 2007 and 2009, von Beust was one of 32 members of the Second Commission on the modernization of the federal state, which had been established to reform the division of powers between federal and state authorities in Germany.  Third term  In the Hamburg elections of 24 February 2008, the CDU gained 42.6 percent of the vote. Thus, the CDU continued to be the strongest party in Hamburg. However, since the CDU lost its absolute majority, it formed a coalition government with the Greens. At the time, the two party's cooperation was widely seen as a test for a possible coalition at the national level.  In February 2009, von Beust and Minister President Peter Harry Carstensen of Schleswig-Holstein agreed on a €13 billion bailout of state-owned shipping financier HSH Nordbank. The two states were forced to intervene after the SoFFin fund, which had been set up by the federal government in 2008 to stabilize the financial markets, said it could not help out HSH Nordbank until it got rid of all its bad debts.  Ahead of the 2009 national elections, von Beust was tipped as potential Federal Minister for Economic Cooperation and Development in the cabinet of Chancellor Angela Merkel; in the negotiations on a coalition agreement with the FDP, however, the position went to Dirk Niebel.  In 2010, von Beust became the first German state leader to indicate that his state was in principle willing to provide humanitarian solutions for former Guantanamo inmates approved for release; Hamburg later accepted one released detainee.  On 18 July 2010 Ole von Beust announced his resignation, to take effect on 25 August. Leaving office alongside von Beust were Karin von Welck, Hamburg's State Minister for Culture, and Volkmar Schoen of the senate chancellery.  Shortly after, voters in Hamburg toppled von Beust's proposed education reforms in the city-state's first binding referendum. The vote assured the preservation of Hamburg's four-year primary schools, rather than extending primary education to six years, which the ruling coalition of Christian Democrats and Greens had proposed.

Life after politics.

Upon leaving active politics, von Beust opened his own law firm and joined consultancy Roland Berger as advisor. In 2012, he succeeded Klaus von Dohnányi as Executive Director of the Hamburg Foundation for Politically Persecuted People.  During a strike of ground crew at Frankfurt Airport in February 2012, von Beust was appointed as arbitrator by airport operator Fraport for negotiations with trade union GdF. The union accepted his proposed settlement plan; Fraport, however, rejected the deal.  In addition, von Beust has been holding various paid and unpaid positions, including the following:  In late 2015, von Beust was named co-chairman (alongside Jürgen Trittin and Matthias Platzeck) of a government-appointed commission tasked with recommending by early 2016 how to safeguard the funding of fulfilling Germany's exit from nuclear energy. By April 2016, the commission agreed to ask the power firms to pay €23.3 billion ($26.4 billion) into a state fund to cover the costs of nuclear waste storage.

Recognition.

Von Beust was a finalist for the World Mayor prize of 2010.

Carl-Friedrich Arp Ole Freiherr von Beust, generally called Ole von Beust (born 13 April 1955), was a German politician who was First Mayor of Hamburg from 31 October 2001 to 25 August 2010, serving as President of the Bundesrat from 1 November 2007 on for one year. He was succeeded as mayor by Christoph Ahlhaus.


Family and education.

Lafontaine was born in Saarlouis into a family of craftsmen. His father, Hans Lafontaine, was a professional baker and was killed serving in World War II. He spent his childhood living with his mother, Katharina (née Ferner), and his twin brother, Hans, in Dillingen.  He attended a Catholic episcopal boarding institution in Prüm and there was educated at the Regino-Gymnasium, a public school. He left school in 1962 and received a scholarship from Cusanuswerk, the scholarship body of the Catholic Church in Germany, to study physics at the universities of Bonn and Saarland. Lafontaine graduated in 1969; his thesis concerned the production of monocrystalline barium titanate. He worked for "Versorgungs- und Verkehrsgesellschaft" Saarbrücken until 1974, serving on its board from 1971.  Lafontaine has been married four times and has two sons by his second and third wives. In November 2011, Lafontaine officially presented fellow politician Sahra Wagenknecht as his new girlfriend, who is 26 years his junior. Since December 22, 2014 they have been married. He is a non-practising Catholic.

Political rise.

Lafontaine rose to prominence locally as mayor of Saarbrücken and became more widely known as a critic of chancellor Helmut Schmidt's support for the NATO plan to deploy Pershing II missiles in Germany. From 1985 to 1998 he served as Minister-President of the Saarland. In this position he struggled to preserve the industrial base of the state, which was based on steel production and coal mining with subsidies, and served as President of the Bundesrat in 1992/93.

Chancellor candidacy and assassination attempt.

Lafontaine was the SPD's candidate for Chancellor in the German federal election of 1990. He faced nearly impossible odds. The election had been called two months after the reunification of Germany, and the incumbent government of Helmut Kohl was in a nearly unassailable position.  During the campaign he was attacked with a knife by a mentally deranged woman after a speech in Cologne. His carotid artery was slashed and he remained in a critical condition for several days.

Political comeback.

At the "Mannheim convention" in 1995, he was elected chairman of the SPD in a surprise move, replacing Rudolf Scharping. He was mainly responsible for bringing the whole political weight of the SPD to bear against Kohl and his CDU party, rejecting bipartisan cooperation that had characterized German politics for many years. Lafontaine argued that any help given to Kohl would only lengthen his unavoidable demise.  After the SPD's unexpectedly clear victory at the polls in September 1998, he was appointed Federal Minister of Finance in the first government of Gerhard Schröder.

Minister of Finance.

During his short tenure as Minister of Finance, Lafontaine was a main bogeyman of UK Eurosceptics. This was because, among other things, he had called for the prompt tax harmonisation of the European Union, which would have resulted in an increase in UK taxes. In 1998, English tabloid "The Sun" called Lafontaine "Europe's most dangerous man". On 11 March 1999, he resigned from all his official and party offices, claiming that "lack of cooperation" in the cabinet had become unbearable. Until the formation of the Left Party he was known for his attacks against the Schroeder government in the tabloid "Bild-Zeitung", which is generally considered conservative.

Leaving the SPD and formation of The Left party.

On 24 May 2005 Lafontaine left the SPD. After two weeks of speculation it was announced on 10 June that he would run as the lead candidate for The Left party ("Die Linke"), a coalition of the Labor and Social Justice Party (WASG), which was based in western Germany, and the Left Party.PDS, which was the successor to the ruling East German Socialist Unity Party (SED). Lafontaine joined the WASG on 18 June 2005 and was selected to head their list for the 2005 Federal Election in North Rhine-Westphalia on the same day. Moreover, he also unsuccessfully contested the Saarbrücken constituency, which he had previously represented from 1990 to 2002. Nevertheless, the result of the Left party in the Saarland was by far the best in any of the federal states in the West of Germany.  In 2007, when the Left Party was formed in a merger between 'Left Party.PDS' and WASG, he became chairman alongside Lothar Bisky.  In May 2009, he declared that "Financial capitalism has failed. We need to democratize the economy. The workforce needs to have a far greater say in their companies than has been the case so far."

Criticism.

An article by Lafontaine on Erich Honecker, state and party leader of the German Democratic Republic and a fellow Saarlander, in the magazine "Der Spiegel" was criticised as laudatory by many observers. In the late 1980s and early 1990s, he tarnished his left-wing credentials with a plea for pro-business policies and a call for the reduction of the influx of Germans from Eastern Europe and asylum-seekers.  Lafontaine lives in a manor-like house, commonly known as the "palace of social justice" ("Palast der sozialen Gerechtigkeit"). When asked about whether this could be in conflict with his socialist ideas, Lafontaine said politicians of the left do not have to be poor, but they have to fight against poverty.

Oskar Lafontaine (; born 16 September 1943) is a German politician. He served as Minister-President of the state of Saarland from 1985 to 1998, and was federal leader of the Social Democratic Party (SPD) from 1995 to 1999. He was the lead candidate for the SPD in the 1990 German federal election, but lost by a wide margin. He served as Minister of Finance under Chancellor Gerhard Schröder after the SPD's victory in the 1998 federal election, but resigned from both the ministry and Bundestag less than six months later, positioning himself as a popular opponent of Schröder's policies in the tabloid press.


Screening.

Cancer screening is recommended for cancers of breast, cervix, colon, and lung.

Signs and symptoms.

Signs and symptoms usually depend on the size and type of cancer.

Diagnosis and staging.

Diagnostic and staging investigations depend on the size and type of malignancy.

Blood cancer.

Blood investigations including hemoglobin, total leukocyte count, platelet count, peripheral smear, red cell indices.  Bone marrow studies including aspiration, flow cytometry, cytogenetics, fluorescent in situ hybridisation and molecular studies.

Lymphoma.

Excision biopsy of lymph node for histopathological examination, immunohistochemistry, and molecular studies.  Blood investigations include lactate dehydrogenase (LDH), serum uric acid, and kidney function tests.  Imaging tests such as computerised tomography (CT scan), positron emission tomography (PET CT).  Bone marrow biopsy.

Solid tumors.

Biopsy for histopathology and immunohistochemistry.  Imaging tests like X-ray, ultrasonography, computerised tomography (CT), magnetic resonance imaging (MRI) and PET CT.  Endoscopy including Naso-pharyngoscopy, Direct & Indirect Laryngoscopy, Upper Gastrointestinal Endoscopy, Colonoscopy, Cystoscopy.  Tumor markers including alphafetoprotein (AFP), Beta Human Chorionic Gonadotropin (HCG), Carcinoembionic Antigen (CEA), CA 125, Prostate specific antigen (PSA).

Treatment.

Treatment depends on the size and type of cancer.

Lymphoma.

It includes Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL):

Blood cancer.

Includes acute and chronic leukemias. Acute leukemias includes acute lymphoblastic leukemia (ALL), and acute myeloid leukemia (AML). Chronic leukemias include chronic lymphocytic leukemia (CLL), and chronic myeloid leukemia (CML).

Oncology is a branch of medicine that deals with the prevention, diagnosis, and treatment of cancer. A medical professional who practices oncology is an "oncologist". The name's etymological origin is the Greek word ὄγκος ("óngkos"), meaning 1. "burden, volume, mass" and 2. "barb", and the Greek word λόγος ("logos"), meaning "study".


Characteristics.

Physical properties.

Plutonium, like most metals, has a bright silvery appearance at first, much like nickel, but it oxidizes very quickly to a dull gray, although yellow and olive green are also reported. At room temperature plutonium is in its α ("alpha") form. This, the most common structural form of the element (allotrope), is about as hard and brittle as gray cast iron unless it is alloyed with other metals to make it soft and ductile. Unlike most metals, it is not a good conductor of heat or electricity. It has a low melting point (640 °C) and an unusually high boiling point (3,228 °C).  Alpha decay, the release of a high-energy helium nucleus, is the most common form of radioactive decay for plutonium. A 5 kg mass of Pu contains about atoms. With a half-life of 24,100 years, about of its atoms decay each second by emitting a 5.157 MeV alpha particle. This amounts to 9.68 watts of power. Heat produced by the deceleration of these alpha particles makes it warm to the touch.  Resistivity is a measure of how strongly a material opposes the flow of electric current. The resistivity of plutonium at room temperature is very high for a metal, and it gets even higher with lower temperatures, which is unusual for metals. This trend continues down to 100 K, below which resistivity rapidly decreases for fresh samples. Resistivity then begins to increase with time at around 20 K due to radiation damage, with the rate dictated by the isotopic composition of the sample.  Because of self-irradiation, a sample of plutonium fatigues throughout its crystal structure, meaning the ordered arrangement of its atoms becomes disrupted by radiation with time. Self-irradiation can also lead to annealing which counteracts some of the fatigue effects as temperature increases above 100 K.  Unlike most materials, plutonium increases in density when it melts, by 2.5%, but the liquid metal exhibits a linear decrease in density with temperature. Near the melting point, the liquid plutonium has very high viscosity and surface tension compared to other metals.

Allotropes.

Plutonium normally has six allotropes and forms a seventh (zeta, ζ) at high temperature within a limited pressure range. These allotropes, which are different structural modifications or forms of an element, have very similar internal energies but significantly varying densities and crystal structures. This makes plutonium very sensitive to changes in temperature, pressure, or chemistry, and allows for dramatic volume changes following phase transitions from one allotropic form to another. The densities of the different allotropes vary from 16.00 g/cm to 19.86 g/cm.  The presence of these many allotropes makes machining plutonium very difficult, as it changes state very readily. For example, the α form exists at room temperature in unalloyed plutonium. It has machining characteristics similar to cast iron but changes to the plastic and malleable β ("beta") form at slightly higher temperatures. The reasons for the complicated phase diagram are not entirely understood. The α form has a low-symmetry monoclinic structure, hence its brittleness, strength, compressibility, and poor thermal conductivity.  Plutonium in the δ ("delta") form normally exists in the 310 °C to 452 °C range but is stable at room temperature when alloyed with a small percentage of gallium, aluminium, or cerium, enhancing workability and allowing it to be welded. The δ form has more typical metallic character, and is roughly as strong and malleable as aluminium. In fission weapons, the explosive shock waves used to compress a plutonium core will also cause a transition from the usual δ phase plutonium to the denser α form, significantly helping to achieve supercriticality. The ε phase, the highest temperature solid allotrope, exhibits anomalously high atomic self-diffusion compared to other elements.

Nuclear fission.

Plutonium is a radioactive actinide metal whose isotope, plutonium-239, is one of the three primary fissile isotopes (uranium-233 and uranium-235 are the other two); plutonium-241 is also highly fissile. To be considered fissile, an isotope's atomic nucleus must be able to break apart or fission when struck by a slow moving neutron and to release enough additional neutrons to sustain the nuclear chain reaction by splitting further nuclei.  Pure plutonium-239 may have a multiplication factor (k) larger than one, which means that if the metal is present in sufficient quantity and with an appropriate geometry (e.g., a sphere of sufficient size), it can form a critical mass. During fission, a fraction of the nuclear binding energy, which holds a nucleus together, is released as a large amount of electromagnetic and kinetic energy (much of the latter being quickly converted to thermal energy). Fission of a kilogram of plutonium-239 can produce an explosion equivalent to. It is this energy that makes plutonium-239 useful in nuclear weapons and reactors.  The presence of the isotope plutonium-240 in a sample limits its nuclear bomb potential, as plutonium-240 has a relatively high spontaneous fission rate (~440 fissions per second per gram—over 1,000 neutrons per second per gram), raising the background neutron levels and thus increasing the risk of predetonation. Plutonium is identified as either weapons-grade, fuel-grade, or reactor-grade based on the percentage of plutonium-240 that it contains. Weapons-grade plutonium contains less than 7% plutonium-240. Fuel-grade plutonium contains from 7% to less than 19%, and power reactor-grade contains 19% or more plutonium-240. Supergrade plutonium, with less than 4% of plutonium-240, is used in U.S. Navy weapons stored in proximity to ship and submarine crews, due to its lower radioactivity. The isotope plutonium-238 is not fissile but can undergo nuclear fission easily with fast neutrons as well as alpha decay.

Isotopes and nucleosynthesis.

Twenty radioactive isotopes of plutonium have been characterized. The longest-lived are plutonium-244, with a half-life of 80.8 million years, plutonium-242, with a half-life of 373,300 years, and plutonium-239, with a half-life of 24,110 years. All of the remaining radioactive isotopes have half-lives that are less than 7,000 years. This element also has eight metastable states, though all have half-lives less than one second.  The known isotopes of plutonium range in mass number from 228 to 247. The primary decay modes of isotopes with mass numbers lower than the most stable isotope, plutonium-244, are spontaneous fission and alpha emission, mostly forming uranium (92 protons) and neptunium (93 protons) isotopes as decay products (neglecting the wide range of daughter nuclei created by fission processes). The primary decay mode for isotopes with mass numbers higher than plutonium-244 is beta emission, mostly forming americium (95 protons) isotopes as decay products. Plutonium-241 is the parent isotope of the neptunium decay series, decaying to americium-241 via beta emission.  Plutonium-238 and 239 are the most widely synthesized isotopes. Plutonium-239 is synthesized via the following reaction using uranium (U) and neutrons (n) via beta decay (β) with neptunium (Np) as an intermediate:  </chem>  Neutrons from the fission of uranium-235 are captured by uranium-238 nuclei to form uranium-239; a beta decay converts a neutron into a proton to form neptunium-239 (half-life 2.36 days) and another beta decay forms plutonium-239. Egon Bretscher working on the British Tube Alloys project predicted this reaction theoretically in 1940.  Plutonium-238 is synthesized by bombarding uranium-238 with deuterons (D, the nuclei of heavy hydrogen) in the following reaction:  \ce

Plutonium is a radioactive chemical element with the symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen. When exposed to moist air, it forms oxides and hydrides that can expand the sample up to 70% in volume, which in turn flake off as a powder that is pyrophoric. It is radioactive and can accumulate in bones, which makes the handling of plutonium dangerous.


Etymology.

The word "poltergeist" comes from the German language words "poltern" ("to make sound" and "to rumble") and "Geist" ("ghost" and "spirit"), and the term itself translates as "noisy ghost", "rumble-ghost" or a "loud spirit". A synonym coined by René Sudre is "thorybism", from Greek "thorybein" ("to make noise or uproar; throw into confusion").

Suggested explanations.

Natural phenomena.

Many claimed poltergeist events have proved on investigation to be hoaxes.  Psychical researcher Frank Podmore proposed the 'naughty little girl' theory for poltergeist cases (many of which have seemed to centre on an adolescent, usually a girl). He found that the centre of the disturbance was often a child who was throwing objects around to fool or scare people for attention. Skeptical investigator Joe Nickell says that claimed poltergeist incidents typically originate from "an individual who is motivated to cause mischief". According to Nickell:  "In the typical poltergeist outbreak, small objects are hurled through the air by unseen forces, furniture is overturned, or other disturbances occur—usually just what could be accomplished by a juvenile trickster determined to plague credulous adults."  Nickell writes that reports are often exaggerated by credulous witnesses.  "Time and again in other “poltergeist” outbreaks, witnesses have reported an object leaping from its resting place supposedly on its own, when it is likely that the perpetrator had secretly obtained the object sometime earlier and waited for an opportunity to fling it, even from outside the room—thus supposedly proving he or she was innocent."  According to research in anomalistic psychology, claims of poltergeist activity can be explained by psychological factors such as illusion, memory lapses, and wishful thinking. A study (Lange and Houran, 1998) wrote that poltergeist experiences are delusions "resulting from the affective and cognitive dynamics of percipients' interpretation of ambiguous stimuli". Psychologist Donovan Rawcliffe has written that almost all poltergeist cases that have been investigated turned out to be based on trickery, whilst the rest are attributable to psychological factors such as hallucinations.  Attempts have also been made to scientifically explain poltergeist disturbances that have not been traced to fraud or psychological factors. Skeptic and magician Milbourne Christopher found that some cases of poltergeist activity can be attributed to unusual air currents, such as a 1957 case on Cape Cod where downdrafts from an uncovered chimney became strong enough to blow a mirror off of a wall, overturn chairs and knock things off shelves.

Unverified natural phenomena.

In the 1950s, Guy William Lambert proposed that reported poltergeist phenomena could be explained by the movement of underground water causing stress on houses. He suggested that water turbulence could cause strange sounds or structural movement of the property, possibly causing the house to vibrate and move objects. Later researchers, such as Alan Gauld and Tony Cornell, tested Lambert's hypothesis by placing specific objects in different rooms and subjecting the house to strong mechanical vibrations. They discovered that although the structure of the building had been damaged, only a few of the objects moved a very short distance. The skeptic Trevor H. Hall criticized the hypothesis claiming if it was true "the building would almost certainly fall into ruins." According to Richard Wiseman the hypothesis has not held up to scrutiny.  Michael Persinger has theorized that seismic activity could cause poltergeist phenomena. However, Persinger's claims regarding the effects of environmental geomagnetic activity on paranormal experiences have not been independently replicated and, like his findings regarding the God helmet, may simply be explained by the suggestibility of participants.  David Turner, a retired physical chemist, suggested that ball lightning might cause the "spooky movement of objects blamed on poltergeists."

Paranormal.

Parapsychologists Nandor Fodor and William G. Roll suggested that poltergeist activity can be explained by psychokinesis.  Poltergeist activity has often been believed to be the work of malicious spirits by spiritualists. According to Allan Kardec, the founder of Spiritism, poltergeists are manifestations of disembodied spirits of low level, belonging to the sixth class of the third order. Under this explanation, they are believed to be closely associated with the elements (fire, air, water, earth).  Psychoanalyst Carl Gustav Jung was interested in the concept of poltergeists and the occult in general. Jung believed that a female cousin's trance states were responsible for a dining table splitting in two and his later discovery of a broken bread knife. Jung also believed that when a bookcase gave an explosive cracking sound during a meeting with Sigmund Freud in 1909, he correctly predicted there would be a second sound, speculating that such phenomena was caused by 'exteriorization' of his subconscious mind. Freud disagreed, and concluded there was some natural cause. Freud biographers maintain the sounds were likely caused by the wood of the bookcase contracting as it dried out.

In ghostlore, a poltergeist ( or ; German for "noisy ghost" or "noisy spirit") is a type of ghost or spirit that is responsible for physical disturbances, such as loud noises and objects being moved or destroyed. They are purportedly capable of pinching, biting, hitting, and tripping people. Most accounts of poltergeists describe the movement or levitation of objects such as furniture and cutlery, or noises such as knocking on doors.


Early life.

Probus was born between 230 and 235 (exact date of birth unknown) in Sirmium (modern day Sremska Mitrovica), Pannonia Inferior, the son of Dalmatius. According to the Alexandrian Chronicle, he was born sometime in the year 232.

Military career.

Probus entered the army around 250 upon reaching adulthood. He rose rapidly through the ranks, repeatedly earning high military decorations. Appointed as a military tribune by the emperor Valerian, at a very young age, in recognition of his latent ability, he justified the choice by a distinguished victory over the Sarmatians on the Illyrian frontier. During the chaotic years of the reign of Valerian, Illyria was the only province, generaled by such officers as Claudius, Aurelian and Probus, where the barbarians were kept at bay, while Gaul was overrun by the Franks, Rhaetia by the Alemans, Thrace and the Mediterranean by the Goths, and the east by Shapur I. Probus became amongst the highest placed lieutenants of Aurelian, reconquering Egypt from Zenobia in 273 A.D. Emperor Tacitus, upon his accession in 275, appointed Probus supreme chief of the east, granting him extraordinary powers in order to secure a dangerous frontier. Though the details are not specified, he is said to have fought with success on almost every frontier of the empire, before his election as emperor by the troops upon Tacitus' death of old age in 276, in his camp in Asia Minor.

As emperor.

Florianus, the half-brother of Tacitus, also proclaimed himself emperor, and took control of Tacitus' army in Asia Minor, but was killed by his own soldiers after an indecisive campaign against Probus in the mountains of Cilicia. In contrast to Florianus, who ignored the wishes of the senate, Probus referred his claim to Rome in a respectful dispatch. The senate enthusiastically ratified his pretensions. Probus next travelled west, defeating the Goths along the lower Danube in 277, and acquiring the title of "Gothicus". However, the Goths came to respect his ability and implored a treaty with the empire. In 278, Probus campaigned successfully in Gaul against the Alamanni and Longiones; both tribes had advanced through the Neckar valley and across the Rhine into Roman territory. Meanwhile, his generals defeated the Franks and these operations were directed to clearing Gaul of Germanic invaders (Franks and Burgundians), allowing Probus to adopt the titles of "Gothicus Maximus" and "Germanicus Maximus". Reportedly, 400,000 barbarians were killed during Probus' campaign, and the entire nation of the Lugii were extirpated.  After the defeat of the Germanic invaders in Gaul, Probus crossed the Rhine to campaign successfully against the Barbarians in their homeland, forcing them to pay homage. In the aftermath of the campaign, Probus repaired the ancient fortifications erected by Hadrian in the vulnerable space between the Rhine and Danube, in the territory of Swabia. More significantly, Probus, by forcing from the vanquished tribes a tribute of manpower, established the precedent of settling barbarians within the empire as auxiliaries on a large scale. The provinces were depopulated by war, disease and the chaotic administration, heavy taxation, and extensive army recruitment, during the crisis of the Third century, and the barbarian colonies, at least in the short term, helped to restore frontier defense and the practice of agriculture.  The army discipline which Aurelian had repaired was cultivated and extended under Probus, who was however more shy in the practice of cruelty.  In 279–280, Probus was, according to Zosimus, in Raetia, Illyricum and Lycia, where he fought the Vandals. In the same years, Probus' generals defeated the Blemmyes in Egypt. Either then, or during his previous command in Egypt, he ordered the reconstruction of bridges and canals along the Nile, where the production of grain for the Empire was centered.  In 280–281, Probus put down three usurpers, Julius Saturninus, Proculus and Bonosus. The extent of these revolts is not clear, but there are clues that they were not just local problems (an inscription with the name of Probus erased has been found as far as Spain). Following this, Probus then put down a revolt by an unnamed rebel in Britain with the assistance of a certain Victorinus, who was later made consul in 282. During the winter of 281, the emperor was in Rome, where he celebrated his well-deserved triumph. Probus was eager to start his eastern campaign, delayed by the revolts in the west. He left Rome in 282, travelling first towards Sirmium, his birth city.

Assassination.

Different accounts of Probus's death exist. According to Joannes Zonaras, the commander of the Praetorian Guard Marcus Aurelius Carus had been proclaimed, more or less unwillingly, emperor by his troops.  Probus sent some troops against the new usurper, but when those troops changed sides and supported Carus, Probus' remaining soldiers assassinated him at Sirmium (September/October 282). According to other sources, however, Probus was killed by disgruntled soldiers, who rebelled against his orders to be employed for civic purposes, like draining marshes. Allegedly, the soldiers were provoked when they overheard him lamenting the necessity of a standing army. Carus was proclaimed emperor after Probus' death and avenged the murder of his predecessor.

Legacy.

According to the favorable treatment of Gibbon (whose account is largely derived from the "Augustan History"), Probus was the last of the benevolent constitutional emperors of Rome. While his successor Carus (Imp. 282-284) simply disdained to seek the senate's confirmation of his title, the latter's successor Diocletian (Imp. 284-305) took active measures to undermine its authority, and established the autocratic nature and divine derivation of the Imperial power. Never again, after Diocletian's reforms, would the Roman senate play an active role in the management of the empire. On the military sphere, Probus' victories continued the succession of martial Illyrian emperors begun by Claudius Gothicus, which restored the military supremacy of Rome after defeats sustained during the crisis of the third century.  Attribution:

Probus (; Marcus Aurelius Probus; c. 19 August 232 – September/October 282) was Roman Emperor from 276 to 282. Probus was an active and successful general as well as a conscientious administrator, and in his reign of six years he secured prosperity for the inner provinces while withstanding repeated inundations of hostile barbarian tribes on almost every sector of the frontier.


The Hitchhiker's Guide to the Galaxy (novel)

Plot summary.

Earthman Arthur Dent is saved by his friend, Ford Prefect—an alien researcher for the titular "Hitchhiker's Guide to the Galaxy", which provides info on every planet in the galaxy—from the Earth just before it is destroyed by the alien Vogons. After being tossed out of the Vogon ship that they hitched a ride on, Arthur and Ford are rescued by the "Heart of Gold", a spaceship driven by Zaphod Beeblebrox, Ford's semi-cousin and the President of the Galaxy. The ship's crew—Arthur, Ford, Zaphod, a depressed robot named Marvin, and a human woman named Trillian—embark on a journey to find the legendary planet known as Magrathea.  On Magrathea, the five are taken into the planet's centre by a man named Slartibartfast. There, they learn that in the distant past a race of "hyperintelligent, pan-dimensional beings" created a supercomputer named Deep Thought to determine the answer to the "Ultimate Question to Life, the Universe, and Everything", which Deep Thought found to be the number 42. Deep Thought tells its creators that the answer makes no sense to them because they didn't know what the "Ultimate Question" had been in the first place, so he suggested designing an even greater computer to determine what the Ultimate Question was. This computer is actually the planet Earth, which was constructed by the Magratheans, and was five minutes away from finishing its task and figuring out the Ultimate Question when the Vogons destroyed it. The pet mice Trillian has are actually part of the group of hyperintelligent superbeings. They reject the idea of building a new Earth to start the process over and offer to buy Arthur's brain in case it contains the question, leading to a fight when he declines. Zaphod saves Arthur from having his brain removed, the five escape Magrathea, and decide to go to The Restaurant at the End of the Universe.

Illustrated edition.

"The Illustrated Hitchhiker's Guide to the Galaxy" is a specially designed book made in 1994. It was first printed in the United Kingdom by Weidenfeld & Nicolson and in the United States by Harmony Books (who sold it for $42.00). It is an oversized book, and came in silver-foil "holographic" covers in both the UK and US markets. It features the first appearance of the 42 Puzzle, designed by Adams himself, a photograph of Adams and his literary agent Ed Victor as the two space cops, and many other designs by Kevin Davies, who has participated in many Hitchhiker's related projects since the stage productions in the late 1970s. Davies himself appears as Prosser. This edition is out of print – Adams bought up many remainder copies and sold them, autographed, on his website.

In other media.

Audiobook adaptations.

There have been three audiobook recordings of the novel. The first was an abridged edition (), recorded in the mid-1980s by Stephen Moore, best known for playing the voice of Marvin the Paranoid Android in the radio series, LP adaptations and in the TV series. In 1990, Adams himself recorded an unabridged edition for Dove Audiobooks (), later re-released by New Millennium Audio () in the United States and available from BBC Audiobooks in the United Kingdom. Also by arrangement with Dove, ISIS Publishing Ltd produced a numbered exclusive edition signed by Douglas Adams () in 1994. To tie-in with the 2005 film, actor Stephen Fry, the film's voice of the Guide, recorded a second unabridged edition ().

Television series.

The popularity of the radio series gave rise to a six-episode television series, directed and produced by Alan J. W. Bell, which first aired on BBC 2 in January and February 1981. It employed many of the actors from the radio series and was based mainly on the radio versions of Fits the First through Sixth. A second series was at one point planned, with a storyline, according to Alan Bell and Mark Wing-Davey that would have come from Adams's abandoned "Doctor Who and the Krikkitmen" project (instead of simply making a TV version of the second radio series). However, Adams got into disputes with the BBC (accounts differ: problems with budget, scripts, and having Alan Bell involved are all offered as causes), and the second series was never made. Elements of "Doctor Who and the Krikkitmen" were instead used in the third novel, "Life, the Universe and Everything".  The main cast was the same as the original radio series, except for David Dixon as Ford Prefect instead of McGivern, and Sandra Dickinson as Trillian instead of Sheridan.

Film adaptation.

"The Hitchhiker's Guide to the Galaxy" was adapted into a science fiction comedy film directed by Garth Jennings and released on 28 April 2005 in the UK, Australia and New Zealand, and on the following day in the United States and Canada. It was rolled out to cinemas worldwide during May, June, July, August and September.

Series.

The deliberately misnamed "Hitchhiker's Guide to the Galaxy" ""Trilogy"" consists of six books, five written by Adams: "The Hitchhiker's Guide to the Galaxy" (1979), "The Restaurant at the End of the Universe" (1980), "Life, the Universe and Everything" (1982), "So Long, and Thanks for All the Fish" (1984) and "Mostly Harmless" (1992). On 16 September 2008 it was announced that Irish author Eoin Colfer was to pen a sixth book. The book, entitled "And Another Thing...", was published in October 2009, on the 30th anniversary of the publication of the original novel.  "The Hitchhiker's Guide to the Galaxy" was never titled "trilogy." It was called that by readers, but the word "trilogy" doesn't appear on the cover of the first three books and was not used until the publication of the fourth book.

Reception.

Greg Costikyan reviewed "The Hitchhiker's Guide to the Galaxy" in "Ares Magazine" #6 and commented that ""The Hitchhiker's Guide" is written with superb English wit, far more humorous than any American sitcom."

Legacy.

The "Babel fish", a creature used in the novel that feeds on brainwaves and can instantly translate alien languages, inspired the name of Babel Fish, the first free online language translator, which launched in 1997.  When Elon Musk's Tesla Roadster was launched into space on the maiden flight of the Falcon Heavy rocket in February 2018, it had the words DON'T PANIC on the dashboard display and carried amongst other items a copy of the novel and a towel.

The Hitchhiker's Guide to the Galaxy is the first of six books in the "Hitchhiker's Guide to the Galaxy" comedy science fiction "trilogy" by Douglas Adams. The novel is an adaptation of the first four parts of Adams' radio series of the same name. The novel was first published in London on 12 October 1979. It sold 250,000 copies in the first three months.


Form.

Rather than forming a tight bulb like the onion, the leek produces a long cylinder of bundled leaf sheaths that are generally blanched by pushing soil around them (trenching). They are often sold as small seedlings in flats that are started off early in greenhouses, to be planted out as weather permits. Once established in the garden, leeks are hardy; many varieties can be left in the ground during the winter to be harvested as needed.

Cultivars.

Leek cultivars may be treated as a single cultivar group, e.g. as "A. ampeloprasum" 'Leek Group'. The cultivars can be subdivided in several ways, but the most common types are "summer leeks", intended for harvest in the season when planted, and overwintering leeks, meant to be harvested in the spring of the year following planting. Summer leek types are generally smaller than overwintering types; overwintering types are generally more strongly flavored. Cultivars include 'King Richard' and 'Tadorna Blue'.

Growing.

Leeks are easy to grow from seed and tolerate standing in the field for an extended harvest, which takes place up to 6 months from planting. The soil in which it is grown has to be loose and drained well; leek can be grown in the same regions where onions can be grown. Leeks usually reach maturity in the autumn months. Leeks can be bunched and harvested early when they are about the size of a finger or pencil, or they can be thinned and allowed to grow to a much larger mature size. Hilling leeks can produce better specimens.  Leeks suffer from insect pests including the thrips species "Thrips tabaci" and the leek moth. Leeks are also susceptible to leek rust ("Puccinia allii").

Cuisine.

Leeks have a mild, onion-like taste. In its raw state, the vegetable is crunchy and firm. The edible portions of the leek are the white base of the leaves (above the roots and stem base), the light green parts, and to a lesser extent the dark green parts of the leaves. The dark green portion is usually discarded because it has a tough texture, but it can be sautéed, or more commonly added to stock for flavor. A few leaves are sometimes tied with twine and other herbs to form a "bouquet garni".  Leeks are typically chopped into slices 5–10 mm thick. The slices have a tendency to fall apart, due to the layered structure of the leek. The different ways of preparing the vegetable are:  Leeks are an ingredient of cock-a-leekie soup, leek and potato soup, and "vichyssoise", as well as plain leek soup.  Because of their symbolism in Wales (see below), they have come to be used extensively in that country’s cuisine. Elsewhere in Britain, leeks have come back into favor only in the last 50 years or so, having been overlooked for several centuries.

Historical consumption.

The Hebrew Bible talks of חציר, identified by commentators as leek, and says it is abundant in Egypt. Dried specimens from archaeological sites in ancient Egypt, as well as wall carvings and drawings, indicate that the leek was a part of the Egyptian diet from at least the second millennium BCE. Texts also show that it was grown in Mesopotamia from the beginning of the second millennium BCE. The leek was the favorite vegetable of the Emperor Nero, who consumed it in soup or in oil, believing it beneficial to the quality of his voice.

Cultural significance.

The leek is one of the national emblems of Wales, and it or the daffodil (in Welsh, the daffodil is known as "Peter's leek", "Cenhinen Bedr") is worn on St. David's Day. According to one legend, King Cadwaladr of Gwynedd ordered his soldiers to identify themselves by wearing the vegetable on their helmets in an ancient battle against the Saxons that took place in a leek field. The Elizabethan poet Michael Drayton stated, in contrast, that the tradition was a tribute to Saint David, who ate only leeks when he was fasting. Whatever the case, the leek has been known to be a symbol of Wales for a long time; Shakespeare, for example, refers to the custom of wearing a leek as an “ancient tradition” in "Henry V". In the play, Henry tells the Welsh officer Fluellen that he, too, is wearing a leek "for I am Welsh, you know, good countryman." The 1985 and 1990 British one pound coins bear the design of a leek in a coronet, representing Wales.  Alongside the other national floral emblems of countries currently and formerly in the Commonwealth or part of the United Kingdom (including the English Tudor Rose, Scottish thistle, Irish shamrock, Canadian maple leaf, and Indian lotus), the Welsh leek appeared on the coronation gown of Elizabeth II. It was designed by Norman Hartnell; when Hartnell asked if he could exchange the leek for the more aesthetically pleasing Welsh daffodil, he was told no.  Perhaps the most visible use of the leek, however, is as the cap badge of the Welsh Guards, a battalion within the Household Division of the British Army.  In Romania, the leek is also widely considered a symbol of Oltenia, a historical region in the southwestern part of the country.

Dietary restrictions.

Mahayana monks do not consume leeks as they are considered to "excite the senses".

The leek is a vegetable, a cultivar of "Allium ampeloprasum", the broadleaf wild leek. The edible part of the plant is a bundle of leaf sheaths that is sometimes erroneously called a stem or stalk. The genus "Allium" also contains the onion, garlic, shallot, scallion, chive, and Chinese onion.