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Roadrunner is a supercomputer built by IBM at the Los Alamos National Laboratory in New Mexico, USA. Currently the world's fastest computer, the US$133-million Roadrunner is designed for a peak performance of 1.7 petaflops, achieving 1.026 on May 25, 2008, and to be the world's first TOP500 Linpack sustained 1.0 petaflops system. It is a one-of-a-kind supercomputer, built from commodity parts, with many novel design features. IBM built the computer for the U.S. Department of Energy's (DOE) National Nuclear Security Administration. It is a hybrid design with 12,960 IBM PowerXCell 8i and 6,480 AMD Opteron dual-core processors in specially designed blade servers connected by Infiniband. The Roadrunner uses Red Hat Enterprise Linux along with Fedora as its operating systems and is managed with xCAT distributed computing software. It also uses the Open MPI Message Passing Interface implementation. Roadrunner occupies approximately 6,000 square feet (560 m2) and became operational in 2008. The DOE plans to use the computer for simulating how nuclear materials age in order to predict whether the USA's aging arsenal of nuclear weapons is safe and reliable. Other uses for the Roadrunner include the sciences, financial, automotive and aerospace industries. [READ THE REST OF THIS ARTICLE]



Mudskippers are are completely amphibious fish, fish that can use their pectoral fins to walk on land. Being amphibious, they are uniquely adapted to intertidal habitats, unlike most fish in such habitats which survive the retreat of the tide by hiding under wet seaweed or in tidal pools. Mudskippers are quite active when out of water, feeding and interacting with one another, for example to defend their territories. They are found in tropical, subtropical and temperate regions, including the Indo-Pacific and the Atlantic coast of Africa. Compared with fully aquatic gobies, these fish present a range of peculiar behavioural and physiological adaptations to an amphibious lifestyle. These include: Anatomical and behavioural adaptations that allow them to move effectively on land as well as in the water. As their name implies, these fish use their fins to move around in a series of skips. They can also flip their muscular body to catapult themselves up to 2 feet (60 cm) into the air. The ability to breathe through their skin and the lining of their mouth (the mucosa) and throat (the pharynx). This is only possible when the mudskipper is wet, limiting mudskippers to humid habitats and requiring that they keep themselves moist. This mode of breathing, similar to that employed by amphibians, is known as cutaneous air breathing. Another important adaptation that aids breathing while out of water are their enlarged gill chambers, where they retain a bubble of air. These large gill chambers close tightly when the fish is above water, keeping the gills moist, and allowing them to function. They act like a scuba diver's cylinders, and supply oxygen for respiration also while on land. And digging deep burrows in soft sediments allow the fish to thermoregulate, avoid marine predators during the high tide when the fish and burrow are submerged, and for laying their eggs. [READ THE REST OF THIS ARTICLE]



The fire knife is a traditional Samoan cultural implement that is used in ceremonial dances. It was originally composed of a machete wrapped in towels on both ends with a portion of the blade exposed in the middle. Tribal performers of fire knife dancing (or Siva Afi as it is called in Samoa) dance while twirling the knife and doing other acrobatic stunts. The towels are set afire during the dances thus explaining the name. Knife dancing has a history which goes back hundreds of years. The modern fire knife dance has its roots in the ancient Samoan exhibition called "ailao" - the flashy demonstration of a Samoan warrior's battle prowess through artful twirling, throwing and catching, and dancing with a war club. The 'ailao could be performed with any warclub and some colonial accounts confirm that women also performed 'ailao at the head of ceremonial processions, especially daughters of high chiefs. During night dances torches were often twirled and swung about by dancers, although a warclub was the usual implement used for 'ailao. Before the introduction of metals, the most common clubs that were wielded and displayed in the 'ailao fashion were elaborately carved heirloom clubs called "anava." These 'anava were frequently carved with serrated edges and jagged "teeth" which characterized the unique Samoan weapon called the "nifo'oti." When European and American whalers and traders began commercial ventures in Samoa they introduced the natives to the long-handled blubber knife and the hooked cane knife. The characteristic metal hook of these tools was readily incorporated into the Samoan wooden nifo'oti which bears the unique hooked element whether carved from wood or forged from steel. One common claim is that the word "nifo'oti" means "tooth of death" but this is not linguistically accurate as Samoan syntax places the modifier after the subject; according to Samoan grammar the term "nifo'oti" would actually mean "dead tooth," hardly as intimidating as the former translation. Fire was added to the knife in 1946 by a Samoan knife dancer named Freddie Letuli, later to become Paramount Chief Letuli Olo Misilagi. Letuli was performing in San Francisco and while practicing, noticed a Hindu Fire eater and also a little girl with lighted batons. The fire eater loaned him some fuel, he wrapped some towels around his knife, and the fire knife dance was born. Although today many commercial performers perform the dance with short staffs or unbladed knives, this is not authentic fire knife dance and is unacceptable in the Samoas except for training purposes. The knives used by performers in American Samoa are still made of machetes, although they are often dulled for younger dancers. [READ THE REST OF THIS ARTICLE]



The MG 42 (shortened from German: Maschinengewehr 42, or "machine gun 42") is a 7.92mm universal machine gun that was developed in Nazi Germany and entered service with the Wehrmacht in 1942. It supplemented and in some instances, replaced the MG 34 general purpose machine gun in all branches of the German Armed Forces, though both weapons were manufactured and used until the end of the war. The MG 42 has a proven record of reliability, durability, simplicity, and ease of operation, but is most notable for being able to produce a stunning volume of suppressive fire. One of the weapon's most notable features was its comparatively high rate of fire of about 1,200 rounds per minute, twice the rate of the British Vickers machine gun and American Browning at 600 round/min. So distinct and terrifying was the weapon that the United States Army created training films to aid its soldiers in dealing with the psychological trauma of facing the weapon in battle. At such a high rate the human ear cannot easily discern the sound of individual bullets being fired, and in use the gun makes a sound described as like "ripping cloth" and giving rise to the nickname "Hitler's buzzsaw", or, more coarsely, "Hitler's zipper" (Soviet soldiers called it the "linoleum ripper"). German soldiers called it Hitlersäge ("Hitler's saw") or "Bonesaw". The gun was sometimes called "Spandau" by British troops from the manufacturer's plates noting the district of Berlin where some were produced, much like the Germans' own World War I MG 08 had been nicknamed. Notwithstanding the MG 42's high rate of fire, the Handbook of the German Army (1940) forbade the firing of more than 250 rounds in a single burst and indicated a sustained rate of no more than 300–350 rounds per minute to minimize barrel wear and over-heating. The MG 42's belt-feed and quick-change barrel system allowed for more prolonged firing in comparison to these weapons. The MG 42's lineage continued past Nazi Germany's defeat, forming the basis for the nearly identical MG1 (MG 42/59), and subsequently evolved into the MG1A3, which was in turn followed by the MG 3. It also spawned the Swiss MG 51, SIG MG 710-3, Austrian MG 74, and the Spanish 5.56mm Ameli light machine gun, and lent many design elements to the American M60 and Belgian MAG. The MG 42 was adopted by a number of armed organizations after the war, and was copied or license-built as well. The MG 3 served with many armies during the Cold War and remains in use to this day. [READ THE REST OF THIS ARTICLE]



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