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top 10 words in brain distribution (in article): wood build wall design size structure light surface type frame |
top 10 words in brain distribution (in article): species animal bird design form common egg body female male |
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top 10 words in brain distribution (not in article): material paint construction window floor tree door plastic roof concrete |
top 10 words in brain distribution (not in article): vehicle wheel tooth tea gear car time aircraft type speed |
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times more probable under desk 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under beetle (words not in the model) | |
| A desk'" is a furniture form and a class of table often used in a work or office setting for reading or writing on or using a computer. Desks often have one or more drawers to store office supplies and papers. Unlike a regular table, usually only one side of a desk is suitable to sit on (though there are some unusual exceptions, such as a partners desk). Not all desks have the form of a table. For instance, an Armoire desk is a desk built within a large wardrobe-like cabinet, and a portable desk is light enough to be placed on a person's lap. Early desks. Desk-style furniture appears not to have been used in classical antiquity or in other ancient centers of civilization in the Middle East or Far East, but there is no specific proof. Medieval illustrations show the first pieces of furniture which seem to have been designed and constructed for reading and writing. Before the invention of the movable type printing press in the 15th century, any reader was potentially a writer or publisher or both, since any book or other document had to be copied by hand. The desks were designed with slots and hooks for bookmarks and for writing implements. Since manuscript volumes were sometimes large, and heavy, desks of the period usually had massive structures. Desks of the Renaissance and later eras had relatively slimmer structures, and more and more drawers as woodworking became more precise and cabinet-making became a distinct trade. It is often possible to find out if a table or other piece of furniture of those times was designed to be used as a desk by looking for a drawer with three small separations (one each for the ink pot, the blotter and the powder tray) and room for the pens. The desk forms we are familiar with in this beginning of the millennium were born mostly in the 17th and 18th centuries. The ergonomic desk of the last decades is the newest addition to a long list of desk forms, but in a way it is only a refinement of the mechanically complex drawing table or drafting table of the end of the 18th century. Industrial era. Refinements to those first desk forms were considerable through the 19th century, as steam-driven machinery made cheap wood-based paper possible in the last periods of the first phase of the industrial revolution. This produced a boom in the number of, or some might say the birth of, the white-collar worker. As these office workers grew in number, desks were mass-produced for them in large quantities, using newer, steam-driven woodworking machinery. This was the first sharp division in desk manufacturing. From then on, limited quantities of finely crafted desks have been constructed by master cabinetmakers for the homes and offices of the rich while the vast majority of desks were assembled rapidly by unskilled labor, from components turned out in batches by machine tools. Thus, age alone does not guarantee that an antique desk is a masterpiece, since this shift took place more than a hundred years ago. More paper and more correspondence drove the need for more complex desks and more specialized desks, such as the rolltop desk which was a mass produced, slatted variant of the classical cylinder desk. It provided a relatively fast and cheap way to lock up the ever increasing flow of paper without having to file everything by the end of the day. Paper documents started leaving the desk as a "home," with the general introduction of filing cabinets. Correspondence and other documents were now too numerous to get enough attention to be rolled up or folded again, then summarized and tagged before being pigeonholed in a small compartment over or under the work surface of the desk. The famous Wooton desk and others were the last manifestations of the "pigeonhole" style. The newer desks could be transformed into many different shapes and angles and were ideal for artists. Steel desks. A smaller boom in office work and desk production occurred at the end of the 19th century and the beginning of the 20th with the introduction of smaller and cheaper electrical presses and efficient carbon papers coupled with the general acceptance of the typewriter. Steel desks were introduced to take heavier loads of paper and withstand the pounding meted out on the typewriters. The L-shaped desk became popular, with the "leg" being used as an annex for the typewriter. Another big boom occurred after the Second World War with the spread of photocopying. Paperwork drove even higher the number of desk workers, whose work surface diminished in size as office rents rose, and the paper itself was moved more and more directly to filing cabinets or sent to records management centers, or transformed into microfilm, or both. Modular desks seating several co-workers close by became common. Even executive or management desks became mass-produced, built of cheap plywood or fiberboard covered with wood veneer, as the number of persons managing the white collar workers became even greater. Student desks. A "'student desk'" can be any desk form meant for use by a student. Usually the term designates a small pedestal desk or writing table constructed for use by a teenager or a pre-teen in his or her room at home. More often than not it is a pedestal desk, with only one of the two pedestals and about two thirds of the desk surface. Such desks are sometimes called left pedestal desks or right pedestal desks depending on the position of the single pedestal. The height of the desk is usually a bit lower than is the case for normal adult desks. In some cases, the desk is connected from the seat to the table. The table is also used for sitting before classes. The desks are usually mass-produced in steel or wood and sold on the consumer market. In addition there is a wide variety of plans available for woodworking enthusiasts. There are many novel forms of student desks made to maximize the relatively restricted area available in a child's room. One of the most common is the bunk bed desk, also known as a loft bed. Impact of computers. Until the late 1980s desks remained a place for paperwork and business negotiation. At the end of this decade though the personal computer was taking hold in large and medium sized businesses. New office suites included a "knee hole" credenza which was a place for a terminal or personal computer and keyboard tray. Soon new office designs also included "U-shape" suites which added a bridge worksurface between the back credenza and front desk. During the North American recession of the early 1990s, many manager and executive workers had to do word processing and other functions previously completed by typing pools and secretaries. This necessitated a more central placement of the computer on these "U-shape" suite desk systems. With computers abounding, "computer paper" became an office staple. The beginning of this paper boom gave birth to the dream of the "paperless office", in which all information would appear on computer monitors. However, the ease of printing personal documents and the lack of comfort with reading text on computer monitors led to a great deal of document printing. The need for paperwork space vied with the rising desk space taken up by computer monitors, CPUs, printers, scanners, and other peripherals. As well, the need for more space led some desk companies to attach some items to the modesty panel at the back of the desk, such as multi-outlets and cabling. Through the "tech boom" of the 1990s, office worker numbers skyrocketed along with the cost of office space rent. The cubicle desk became widely accepted in North America as an economical way of putting more desk workers in the same space without actually shrinking the size of their working surfaces. The cubicle walls have become new place for workers to affix papers and other items once left on the horizontal desktop surface. Even computer monitor frames themselves are used to attach reminder notes and business cards. Early in the 2000s, private office workers found that their side and back computer-placing furniture made it hard to show the contents of a computer screen to guests or co-workers. Manufacturers have responded to this issue by creating "Forward Facing" desks where computer monitors are placed on the front of the "U-shape" workstation. This forward computer monitor placement promotes a clearer sight-line to greet colleagues, increases computer screen privacy and allows for common viewing of information displayed on a screen. References. Articles and books on real and virtual desks and things in between: | Beetles'" are the group of insects with the largest number of known species. They are placed in the order "'Coleoptera'" (from Greek, "koleos", "sheath"; and, "pteron", "wing", thus "sheathed wing"), which contains more described species than in any other order in the animal kingdom, constituting about 25% of all known life-forms. 40% of all described insect species are beetles (about 350,000 species), and new species are frequently discovered. Estimates put the total number of species, described and undescribed, at between 5 and 8 million. Beetles can be found in almost all habitats, but are not known to occur in the sea or in the polar regions. They interact with their ecosystems in several ways. They often feed on plants and fungi, break down animal and plant debris, and eat other invertebrates. Some species are prey of various animals including birds and mammals. Certain species are agricultural pests, such as the Colorado potato beetle "Leptinotarsa decemlineata", the boll weevil "Anthonomus grandis", the red flour beetle "Tribolium castaneum", and the mungbean or cowpea beetle "Callosobruchus maculatus", while other species of beetles are important controls of agricultural pests. For example, beetles in the family Coccinellidae ("ladybirds" or "ladybugs") consume aphids, scale insects, thrips, and other plant-sucking insects that damage crops. Description. The name "Coleoptera" was given by Aristotle for the hardened shield-like forewing (coleo= shield+ ptera= wing). Other characters of this group which are believed to be monophyletic include a holometabolous life cycle; having a prothorax that is distinct from and freely articulating with the mesothorax; the meso- and meta-thoracic segments fusing to form a pterothorax; a depressed body shape with the legs on the ventral surface; the coxae of legs recessed into cavities formed by heavily sclerotized thoracic sclerites; the abdominal sternites more sclerotized than the tergites; antennae with 11 or fewer segments; and terminal genitalic appendages retracted into the abdomen and invisible at rest. The general anatomy of beetles is quite uniform, although specific organs and appendages may vary greatly in appearance and function between the many families in the order. Like all insects, beetles' bodies are divided into three sections: the head, the thorax, and the abdomen. When viewed from below, the thorax is that part from which all three pairs of legs and both pairs of wings arise. The abdomen is everything posterior to the thorax. When viewed from above, most beetles appear to have three clear sections, but this is deceptive: on the beetle's upper surface, the middle "section" is a hard plate called the pronotum, which is only the front part of the thorax; the back part of the thorax is concealed by the beetle's wings. Like all arthropods, beetles are segmented organisms, and all three of the major sections of the body are themselves composed of several further segments, although these are not always readily discernible. This further segmentation is usually best seen on the abdomen. Beetles are generally characterised by a particularly hard exoskeleton and hard forewings (elytra). The beetle's exoskeleton is made up of numerous plates called sclerites, separated by thin sutures. This design creates the armoured defences of the beetle while maintaining flexibility. The elytra are not used for flight, but tend to cover the hind part of the body and protect the second pair of wings ("alae"). The elytra must be raised in order to move the hind flight wings. A beetle's flight wings are crossed with veins and are folded after landing, often along these veins, and are stored below the elytra. In some beetles, the ability to fly has been lost. These include the ground beetles (family Carabidae) and some "true weevils" (family Curculionidae), but also some desert and cave-dwelling species of other families. Many of these species have the two elytra fused together, forming a solid shield over the abdomen. In a few families, both the ability to fly and the elytra have been lost, with the best known example being the glow-worms of the family Phengodidae, in which the females are larviform throughout their lives. Beetles have mouthparts similar to those of grasshoppers. Of these parts, the most commonly known are probably the mandibles, which appear as large pincers on the front of some beetles. The mandibles are a pair of hard, often tooth-like structures that move horizontally to grasp, crush, or cut food or enemies (see defence, below). Two pairs of finger-like appendages are found around the mouth in most beetles, serving to move food into the mouth. These are the maxillary and labial palpi. The eyes are compound and may display remarkable adaptability, as in the case of whirligig beetles (family Gyrinidae), in which the eyes are split to allow a view both above and below the waterline. Other species also have divided eyes — some longhorn beetles (family Cerambycidae) and weevils — while many beetles have eyes that are notched to some degree. A few beetle genera also possess ocelli, which are small, simple eyes usually situated farther back on the head (on the vertex). Beetles' antennae are primarily organs of smell, but may also be used to feel out a beetle's environment physically. They may also be used in some families during mating, or among a few beetles for defence. Antennae vary greatly in form within the Coleoptera, but are often similar within any given family. In some cases, males and females of the same species will have different antennal forms. Antennae may be clavate (flabellate and lamellate are sub-forms of clavate, or clubbed antennae), filiform, geniculate, moniliform, pectinate, or serrate. For images of these antennal forms see antenna (biology). The legs, which are multi-segmented, end in two to five small segments called tarsi. Like many other insect orders beetles bear claws, usually one pair, on the end of the last tarsal segment of each leg. While most beetles use their legs for walking, legs may be variously modified and adapted for other uses. Among aquatic families — Dytiscidae, Haliplidae, many species of Hydrophilidae and others — the legs, most notably the last pair, are modified for swimming and often bear rows of long hairs to aid this purpose. Other beetles have fossorial legs that are widened and often spined for digging. Species with such adaptations are found among the scarabs, ground beetles, and clown beetles (family Histeridae). The hind legs of some beetles, such as flea beetles (within Chrysomelidae) and flea weevils (within Curculionidae), are enlarged and designed for jumping. Oxygen is obtained via a tracheal system. Air enters a series of tubes along the body through openings called spiracles, and is then taken into increasingly finer fibres. Pumping movements of the body force the air through the system. Beetles have hemolymph instead of blood, and the open circulatory system of the beetle is powered by a tube-like heart attached to the top inside of the thorax. Development. Beetles are endopterygotes with complete metamorphosis. A single female may lay from several dozen to several thousand eggs during her lifetime. Eggs are usually laid according to the substrate the larva will feed on upon hatching. Among others, they can be laid loose in the substrate (e.g. flour beetle), laid in clumps on leaves (e.g. Colorado potato beetle), or individually attached (e.g. mungbean beetle and other seed borers) or buried in the medium (e.g. carrot weevil). The larva is usually the principal feeding stage of the beetle life cycle. Larvae tend to feed voraciously once they emerge from their eggs. Some feed externally on plants, such as those of certain leaf beetles, while others feed within their food sources. Examples of internal feeders are most Buprestidae and longhorn beetles. The larvae of many beetle families are predatory like the adults (ground beetles, ladybirds, rove beetles). The larval period varies between species but can be as long as several years. Beetle larvae can be differentiated from other insect larvae by their hardened, often darkened head, the presence of chewing mouthparts, and spiracles along the sides of the body. Like adult beetles, the larvae are varied in appearance, particularly between beetle families. Beetles whose larvae are somewhat flattened and are highly mobile are the ground beetles, some rove beetles, and others; their larvae are described as campodeiform. Some beetle larvae resemble hardened worms with dark head capsules and minute legs. These are elateriform larvae, and are found in the click beetle (Elateridae) and darkling beetle (Tenebrionidae) families. Some elateriform larvae of click beetles are known as wireworms. Beetles in the families of the Scarabaeoidea have short, thick larvae described as scarabaeiform, but more commonly known as grubs. All beetle larvae go through several instars, which are the developmental stages between each moult. In many species the larvae simply increase in size with each successive instar as more food is consumed. In some cases, however, more dramatic changes occur. Among certain beetle families or genera, particularly those that exhibit parasitic lifestyles, the first instar (the planidium) is highly mobile in order to search out a host, while the following instars are more sedentary and remain on or within their host. This is known as hypermetamorphosis; examples include the blister beetles (family Meloidae) and some rove beetles, particularly those of the genus "Aleochara". As with all endopterygotes, beetle larvae pupate, and from this pupa emerges a fully formed, sexually mature adult beetle, or imago. Adults have an extremely variable lifespan, from weeks to years, depending on the species. Reproduction. Beetles may display extremely intricate behaviour when mating. Pheromone communication is thought to be important in the location of a mate. Conflict can play a part in the mating rituals of species such as burying beetles (genus "Nicrophorus") where conflicts between males and females rage until only one of each is left, thus ensuring reproduction by the strongest and fittest. Many male beetles are territorial and will fiercely defend their small patch of territory from intruding males. In such species, the males may often have horns on the head and or thorax, making their overall body lengths greater than those of the females, unlike most insects. Pairing is generally short but in some cases will last for several hours. During pairing sperm cells are transferred to the female to fertilise the egg. Parental care varies between species, ranging from the simple laying of eggs under a leaf to certain scarab beetles, which construct underground structures complete with a supply of dung to house and feed their young. Other beetles are leaf rollers, biting sections of leaves to cause them to curl inwards, then laying their eggs, thus protected, inside. Defense. Beetles and their larvae have a variety of strategies to avoid being attacked by predators or parasitoids. These include camouflage, mimicry, toxicity, and active defense. Camouflage involves the use of colouration or shape to blend into the surrounding environment. This sort of protective coloration is common and widespread among beetle families, especially those that feed on wood or vegetation, such as many of the leaf beetles (family Chrysomelidae) or weevils. In some of these species, sculpturing or various coloured scales or hairs cause the beetle to resemble bird dung or other inedible objects. Many of those that live in sandy environments blend in with the coloration of the substrate. Another defence that often uses colour or shape to deceive potential enemies is mimicry. A number of longhorn beetles (family Cerambycidae) bear a striking resemblance to wasps, which helps them avoid predation even though the beetles are in fact harmless. This defence can be found to a lesser extent in other beetle families, such as the scarab beetles. Beetles may combine their colour mimicry with behavioural mimicry, acting like the wasps they already closely resemble. Many beetle species, including ladybirds, blister beetles, and lycid beetles can secrete distasteful or toxic substances to make them unpalatable or even poisonous. These same species often exhibit aposematism, where bright or contrasting colour patterns warn away potential predators, and there are, not surprisingly, a great many beetles and other insects that mimic these chemically-protected species. Large ground beetles and longhorn beetles may defend themselves using strong mandibles and or spines or horns to forcibly persuade a predator to seek out easier prey. Others, such as bombardier beetles (within Carabidae), may spray chemicals from their abdomen to repel predators. Feeding. Besides being abundant and varied, the Coleoptera are able to exploit the wide diversity of food sources available in their many habitats. Some are omnivores, eating both plants and animals. Other beetles are highly specialised in their diet. Many species of leaf beetles, longhorn beetles, and weevils are very host specific, feeding on only a single species of plant. Ground beetles and rove beetles (family Staphylinidae), among others, are primarily carnivorous and will catch and consume many other arthropods and small prey such as earthworms and snails. While most predatory beetles are generalists, a few species have more specific prey requirements or preferences. Decaying organic matter is a primary diet for many species. This can range from dung, which is consumed by coprophagous species such as certain scarab beetles (family Scarabaeidae), to dead animals, which are eaten by necrophagous species such as the carrion beetles (family Silphidae). Some of the beetles found within dung and carrion are in fact predatory, such as the clown beetles, preying on the larvae of coprophagous and necrophagous insects. Adaptations to the environment. Aquatic beetles use several techniques for retaining air beneath the water's surface. Beetles of the family Dytiscidae hold air between the abdomen and the elytra when diving. Hydrophilidae have hairs on their under surface that retain a layer of air against their bodies. Adult crawling water beetles use both their elytra and their hind coxae (the basal segment of the back legs) in air retention while whirligig beetles simply carry an air bubble down with them whenever they dive. Evolutionary history and classification. While some authorities believe modern beetles began about 140 million years ago, research announced in 2007 showed that beetles may have entered the fossil record during the Lower Permian, about 265 to 300 million years ago. The four extant suborders of beetle are these: These suborders diverged in the Permian and Triassic. Their phylogenetic relationship is uncertain, with the most popular hypothesis being that Polyphaga and Myxophaga are most closely related, with Adephaga as the sister group to those two, and Archostemata as sister to the other three collectively. There are about 350,000 species of beetles. Such a large number of species poses special problems for classification, with some families consisting of thousands of species and needing further division into subfamilies and tribes. Pests. Many agricultural, forestry, and household insect pests are beetles. These include the following: Beneficial organisms. Some farmers develop beetle banks to foster and provide cover for beneficial beetles. Beetles of the Dermestidae family are often used in taxidermy to clean bones of remaining flesh. Beetles in ancient Egypt and other cultures. Several species of dung beetle, most notably "Scarabaeus sacer" (often referred to as "scarab"), enjoyed a sacred status among the ancient Egyptians, as the creatures were likened to the major god Khepri. Some scholars suggest that the Egyptians' practice of making mummies was inspired by the brooding process of the beetle. Many thousands of amulets and stamp seals have been excavated that depict the scarab. In many artifacts, the scarab is depicted pushing the sun along its course in the sky, much as scarabs push or roll balls of dung to their brood sites. During and following the New Kingdom, scarab amulets were often placed over the heart of the mummified deceased. Some tribal groups, particularly in tropical parts of the world, use the colourful, iridescent elytra of certain beetles, especially certain Scarabaeidae, in ceremonies and as adornment. Study and collection. The study of beetles is called coleopterology'" (from "Coleoptera", see above, and Greek, "-logia"), and its practitioners are "coleopterists" (see this list). Coleopterists have formed organisations to facilitate the study of beetles. Among these is The Coleopterists Society, an international organisation based in the United States. Such organisations may have both professionals and amateurs interested in beetles as members. Research in this field is often published in peer-reviewed journals specific to the field of coleopterology, though journals dealing with general entomology also publish many papers on various aspects of beetle biology. Some of the journals specific to beetle research are: There is a thriving industry in the collection of beetle specimens for amateur and professional collectors. Many coleopterists prefer to collect beetle specimens for themselves, recording detailed information about each specimen and its habitat. Such collections add to the body of knowledge about the Coleoptera. Some countries have established laws governing or prohibiting the collection of certain rare (and often much sought after) species. One such beetle whose collection is illegal or restricted is the American burying beetle, "Nicrophorus americanus". |