Wikisnaps! We find what's interesting on Wikipedia, so you don't have to!

The bluntnose sixgill shark, Hexanchus griseus, often simply called the cow shark, is the largest hexanchoid shark, growing to more than 5.4 m (18 ft) in length. Many of its relatives are extinct. The living species that are closest genetically include the dogfish, the Greenland shark, as well as other six- and sevengilled sharks. There are more closely related relatives in the fossil record than living species. Some of the shark's relatives date back to 200 million years ago. This shark is a notable species due to both its primitive and current physical characteristics. This species typically inhabits depths greater than 90 m (300 ft), and has been recorded as deep as 1,875 m (6,150 ft). Like many deep-sea creatures, the bluntnose sixgill shark is known to undertake nightly vertical migrations (travelling surfaceward at night, returning to the depths before dawn). The bluntnose sixgill shark can be seen at depths of 30 m (100 ft) and shallower during parts of the year in some specific places e.g. Flora Islet, near Hornby Island, Sightings during shallow evening dives in Whytecliff Park West Vancouver in British Columbia, in Puget Sound, Monterey Canyon off Monterey, California and in fjords in Norway. The sharks are deepsea sharks, but like most fish that prefer the deep, they come to the shallower depths to feed. Although sluggish in nature, the bluntnose sixgill shark is capable of attaining high speeds for chasing and catching its prey. Because of the bluntnose sixgill shark's large and diverse range they have a wide variety of prey items. Their diet consists of a variety of mollusks, crustaceans, and Agnathans (hagfish and sea lampreys). They also dine on Cape anchovies, Pacific salmon, various species of hake. There are also many more species that are eaten depending upon the shark's home range. Despite its size, the shark is not known to have eaten any humans. [READ THE REST OF THIS ARTICLE]



Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses), that affects birds and mammals. The most common symptoms of the disease are chills, fever, sore throat, muscle pains, severe headache, coughing, weakness/fatigue and general discomfort. Although it is often confused with other influenza-like illnesses, especially the common cold, influenza is a more severe disease than the common cold and is caused by a different type of virus. Influenza may produce nausea and vomiting, particularly in children, but these symptoms are more common in the unrelated gastroenteritis, which is sometimes called inaccurately "stomach flu." Flu can occasionally cause either direct viral pneumonia or secondary bacterial pneumonia. Typically, influenza is transmitted through the air by coughs or sneezes, creating aerosols containing the virus. Influenza can also be transmitted by direct contact with bird droppings or nasal secretions, or through contact with contaminated surfaces. Airborne aerosols have been thought to cause most infections, although which means of transmission is most important is not absolutely clear. Influenza viruses can be inactivated by sunlight, disinfectants and detergents. As the virus can be inactivated by soap, frequent hand washing reduces the risk of infection. Influenza spreads around the world in seasonal epidemics, resulting in the deaths of between 250,000 and 500,000 people every year, up to millions in some pandemic years. On average 41,400 people died each year in the United States between 1979 and 2001 from influenza. In 2010 the Centers for Disease Control and Prevention (CDC) in the United States changed the way it reports the 30 year estimates for deaths. Now they are reported as a range from a low of about 3,300 deaths to a high of 49,000 per year. Vaccinations against influenza are usually made available to people in developed countries. Farmed poultry is often vaccinated to avoid decimation of the flocks. The most common human vaccine is the trivalent influenza vaccine (TIV) that contains purified and inactivated antigens against three viral strains. Typically, this vaccine includes material from two influenza A virus subtypes and one influenza B virus strain. The TIV carries no risk of transmitting the disease, and it has very low reactivity. A vaccine formulated for one year may be ineffective in the following year, since the influenza virus evolves rapidly, and new strains quickly replace the older ones. Antiviral drugs can be used to treat influenza, with neuraminidase inhibitors (such as Tamiflu or Relenza) being particularly effective. [READ THE REST OF THIS ARTICLE]



MS Oasis of the Seas is an Oasis-class cruise ship in the fleet of Royal Caribbean International. The first of her class, she is expected to be joined by her sister ship Allure of the Seas in December 2010. Both vessels are expected to cruise the Caribbean from Fort Lauderdale, Florida. She set a new record of carrying over 6,000 passengers. The ship surpasses the Freedom-class cruise ships (also owned by Royal Caribbean) as the world's largest passenger vessel. The vessel was ordered in February 2006 and designed under the name "Project Genesis". Her keel was laid down on 12 November 2007 at STX Europe (formerly Aker Yards) in Turku, Finland. The company announced that full funding for Oasis of the Seas was secured on 15 April 2009. The name Oasis of the Seas resulted from a competition held in May 2008. The ship was completed and turned over to Royal Caribbean on 28 October 2009. Two days later, she departed Finland for the United States. While exiting the Baltic Sea, the vessel passed underneath the Great Belt Fixed Link in Denmark on 1 November 2009. The bridge has a clearance of 65 m (213 ft) above the water; Oasis normally has an air draft of 72 m (236 ft). The passage under the bridge was possible due to retraction of the telescoping funnels, and an additional 30 cm (12 in) was gained by the squat effect whereby vessels travelling at speed in a shallow channel will be drawn deeper into the water. Approaching the bridge at 20 knots (37 km/h; 23 mph), the ship passed under it with less than 2 feet (60 cm) of clearance. The ship's power comes from six marine diesel engines, three Wärtsilä 16-cylinder common rail diesels producing 25,290 hp each, and three similar 12-cylinder engines each producing 18,590 hp. The total output of these prime movers, some 130,110 hp, is converted to electricity, used in hotel power for operation of the lights, elevators, electronics, galleys, water treatment plant, and all of the other systems used on the operation of the vessel, as well as propulsion. Propulsion is not provided by screws on the end of long shafts piercing the hull, as on most prior ships, but by three, 20,000 kilowatts (26,800 hp) "Azipods", ABB's brand of azimuth thrusters. These pods, suspended under the stern, contain electric motors driving 20-foot (6 m) propellers. Because they are rotatable, no rudders are needed to steer the ship. Docking is assisted by four 5,500 kilowatts (7,380 hp) bow thrusters in tunnels. [READ THE REST OF THIS ARTICLE]



Castle Bravo was the code name given to the first U.S. test of a dry fuel thermonuclear hydrogen bomb device, detonated on March 1, 1954, at Bikini Atoll, Marshall Islands, by the United States, as the first test of Operation Castle (a longer series of tests of various devices). Fallout from the detonation—intended to be a secret test—poisoned the islanders who inhabited the test site, as well as the crew of Daigo Fukuryu Maru ("Lucky Dragon No. 5"), a Japanese fishing boat, and created international concern about atmospheric thermonuclear testing. The bomb used lithium deuteride fuel for the fusion stage, unlike the cryogenic liquid deuterium–tritium used as fuel for the fusion stage of the U.S. experimental Ivy Mike device, which, being the size of a small office building, was an impractical weapon for use at war. The bomb tested at Castle Bravo was the first practical deliverable fusion bomb in the U.S. arsenal. The Soviet Union had previously used lithium deuteride in a nuclear bomb, their Sloika design (known as the "Alarm Clock" in the U.S.), in 1953. It was not a "true" hydrogen bomb, deriving most of its yield from boosted fission reactions, and was limited to a yield of 400 kt. By comparison, the Teller-Ulam-based Ivy Mike device had a yield of 10.4 MT, and Castle Bravo had an even larger yield of 15 MT. In the Teller-Ulam design, the fission and fusion stages were kept physically separate in a reflective cavity. The radiation from the exploding fission primary compressed the fusion secondary to high densities, which could then undergo thermonuclear reactions after being heated by the exploding fission weapon. The Soviets, led by Andrei Sakharov, independently developed and tested their first Teller-Ulam device in 1955. Castle Bravo was the most powerful nuclear device ever detonated by the United States, with a yield of 15 Megatons. That yield, far exceeding the expected yield of 4 to 6 megatons, combined with other factors, led to the most significant accidental radiological contamination ever caused by the United States. [READ THE REST OF THIS ARTICLE]



wikisnap.com is not affiliated with or endorsed by wikipedia. wikipedia and the wikipedia globe are registered trademarks of wikipedia.org.
article content reproduced in compliance with wikipedia's copyright policy and gnu free documentation license
view our privacy policy and terms of service here