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Snake venom is highly modified saliva. The venom is part of a whole: the apparatus, which is made up of venom glands that synthesize venom; and an injection system, consisting of modified fangs with which to make the venom penetrate into a prey item or a possible threat or predator. The glands which secrete the zootoxins are a modification of the parotid salivary gland of other vertebrates, and are usually situated on each side of the head below and behind the eye, encapsulated in a muscular sheath. The glands have large alveoli in which the synthesized venom is stored before being conveyed by a duct to the base of channeled or tubular fangs, through which it is ejected. Venoms contain more than 20 different compounds, mostly proteins and polypeptides. Snake venom has two main functions: first, the immobilization of prey and second, the digestion of prey. It is a complex mixture of proteins, enzymes, and various other substances. The proteins are responsible for the toxic and lethal effect of the venom and its function is to immobilize prey, enzymes play an important role in the digestion of prey, and various other substances are responsible for important but non-lethal biological effects. Some of the proteins in snake venom are very particular in their effects on various biological functions including blood coagulation, blood pressure regulation, transmission of the nervous or muscular impulse and have turned out to be pharmacological or diagnostic tools or even useful drugs. Viper venom acts more on the vascular system, bringing about coagulation of the blood and clotting of the pulmonary arteries; its action on the nervous system is not great, no individual group of nerve-cells appears to be picked out, and the effect upon respiration is not so direct; the influence upon the circulation explains the great depression which is a symptom of viperine envenomation. The pain of the wound is severe, and is speedily followed by swelling and discoloration. [READ THE REST OF THIS ARTICLE]

After Kennedy's assassination, the widowed First Lady, Jacqueline Kennedy, requested an eternal flame for his gravesite. She was inspired by the eternal flame at the Tomb of the Unknown Soldier at the Arc de Triomphe in Paris, which she and her husband had seen during a visit to France in 1961, and/or took inspiration from the "candle in the wind" of Arthurian legend, and the Broadway Play "Camelot." According to William Manchester's Death of a President (1967), Mrs. Kennedy made her request for an eternal flame on the afternoon of November 24, 1963, after she returned to the White House from the lying-in-state ceremony at the Capitol. The military planners who were organizing the funeral granted her request immediately and rushed to implement it. Overnight, the U.S. Army Corps of Engineers ran a gas line to the planned gravesite, fed by propane tanks from a distance. On November 25, 1963, Jacqueline Kennedy lit the flame at the end of the burial service during the state funeral. She did this by bringing a lighted taper, which was handed to her by a soldier, against the nub of the torch mechanism, which was surrounded by evergreen branches. The eternal flame sprang to life immediately, safely with a steady flame. This was seen live on nationwide television and broadcast to other nations by satellite. The late president's brothers, Robert and Ted, then took turns symbolically lighting the flame in the same manner as their sister-in-law. About a month after it was lit, the flame was extinguished for the first and only time, as of 2009. A Catholic school group visiting the site poured, rather than sprinkled, holy water directly onto the flame, and it went out. A quick-thinking guard used his lighter to reignite the fire. The present device rests on top of a five-foot circular granite stone at the head of the grave. It produces a continuous spark which re-ignites the flame whenever it is momentarily extinguished by any means (such as rain, snow, or wind). The device blows a continuous flow of air at the flame, keeping it a uniform color. The 3rd U.S. Infantry Regiment ("The Old Guard") stood vigil over President Kennedy's gravesite from 1963 through 1965, at which time work commenced on a new permanent gravesite at the exact same location. This was due to heavy visitation by the public and the need for paved pathways that would not turn muddy in rain or snow. In 1967, the permanent gravesite was completed, with the eternal flame surrounded by Cape Cod field stones and selections from President Kennedy's Inaugural Address etched on marble panels that face the nation's capital. In late 2012, the eternal flame began malfunctioning. The causes of the malfunction were not known, but the automatic ignition system began clicking audibly. On January 31, 2013, Meltech Corporation of Landover, Maryland, was awarded a $350,000 contract to upgrade the eternal flame. The work required that the permanent flame be extinguished, and a temporary flame displayed to one side. Army Corps of Engineers officials said that this was the first time a temporary flame was used since the permanent flame was installed. A solid white fence surrounded the permanent flame during the renovations, although the headstones of Kennedy and his family was not be obscured. The flame was transferred to the upgraded permanent eternal flame on May 17, 2013, and the temporary flame extinguished. The refurbishment replaced the original 1967 burner with one that did not require a separate oxygen supply, laid new gas lines, relocated gas pressure regulators, installed automated controls to provide a more energy-efficient flame, and laid new electrical cables and replaced aging electrical conduits. [READ THE REST OF THIS ARTICLE]

Target girl is a term sometimes used in circus and vaudeville to denote a female assistant in "impalement" acts such as knife throwing, archery or sharpshooting. The assistant stands in front of a target board or is strapped to a moving board and the impalement artist throws knives or shoots projectiles so as to hit the board but miss the assistant. The image or character of the target girl has also permeated beyond the impalement arts and become an icon in fiction and visual media. Although some assistants are male there is no common equivalent term for a male assistant. This reflects the fact that, historically at least, female assistants have predominated in the acts in question. The presence of an assistant as a human target provides a powerful element of risk. Without assistants placing themselves in danger these acts would be simple demonstrations of accuracy, but with the potential for injury or death the show is much more dramatic. Target girls often wear revealing costumes, thus adding an element of overt sexuality to an act. In this respect there is some similarity to magicians' assistants, although there is a distinct difference in that any apparent danger to an assistant in a magic act is mostly an illusion, whereas impalement acts are demonstrations of accuracy, nerve and calculated risk and the danger is real. While some observers have perceived target girls as masochistic or passive and some feminists criticise the concept as misogynist, several target girls have given accounts of themselves as assertive women and portrayed their experiences as empowering. small group of target girls are notable for the fact that they are well known celebrities who performed the role for charitable purposes or other reasons apart from their main career. These are examples of the target girl, rather than the thrower, being the main individual in the act. The annual Circus of the Stars television special, made by CBS between 1977 and 1994, provided a number of examples. They include: Lynda Carter, the actress best known as television's Wonder Woman, appeared as a target girl on the very first Circus of the Stars in January 1977, with actor David Janssen throwing knives at her and Linda Blair, the actress who rose to fame as a child star in The Exorcist, appeared as a target girl for knife thrower Paul Lacross on Circus of the Stars in 1983. [READ THE REST OF THIS ARTICLE]

The XM307 Advanced Crew Served Weapon (ACSW) is a developmental 25 mm belt-fed Grenade Machine Gun with smart shell capability. It is the result of the OCSW or Objective Crew Served Weapon project. It is lightweight and designed to be two-man portable, as well as vehicle mounted. The XM307 can kill or suppress enemy soldiers out to 2,000 metres (2,187 yd), and destroy lightly armored vehicles, watercraft, and helicopters at 1,000 metres (1,094 yd). The primary advantage of the XM307 is its attenuated recoil system. The weapon controls recoil to a degree that a large tripod and heavy sandbags are not required to effectively employ this weapon. Because of this reduced recoil impulse and light weight, other mounting options are also possible such as small unmanned vehicles and aircraft. The XM307's airburst rounds make it much easier to bypass walls protecting enemies that could cause collateral damage if fired upon directly. Operators do not have to shoot through the wall, just through an opening or over the top to kill the people behind the cover, leaving the structure of the building intact. An additional advantage of the XM307 is that it can be converted into the XM312, a .50 cal version for infantry and light anti-armor support in under two minutes (1min 47sec). [READ THE REST OF THIS ARTICLE] is not affiliated with or endorsed by wikipedia. wikipedia and the wikipedia globe are registered trademarks of
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