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

Ameloblastoma is a rare, benign tumor of odontogenic epithelium much more commonly appearing in the lower jaw than the upper jaw. It was recognized in 1827 by Cusack. This type of odontogenic neoplasm was designated as an adamantinoma in 1885 by the French physician Louis-Charles Malassez. It was finally renamed to the modern name ameloblastoma in 1930 by Ivey and Churchill. While these tumors are rarely malignant or metastatic, and progress slowly, the resulting lesions can cause severe abnormalities of the face and jaw. Additionally, because abnormal cell growth easily infiltrates and destroys surrounding bony tissues, wide surgical excision is required to treat this disorder. Ameloblastomas are often associated with the presence of unerupted teeth. Symptoms include painless swelling, facial deformity if severe enough, pain if the swelling impinges on other structures, loose teeth, ulcers, and periodontal disease. Lesions will occur in the mandible and maxilla,although 75% occur in the ascending ramus area and will result in extensive and grotesque deformitites of the mandible and maxilla. In the maxilla it can extend into the maxillary sinus and floor of the nose. The lesion has a tendency to expand the bony cortices because slow growth rate of the lesion allows time for periosteum to develop thin shell of bone ahead of the expanding lesion. This shell of bone cracks when palpated and this phenomenon is referred to as "Egg Shell Cracking" or crepitus, an important diagnostic feature. Ameloblastoma is tentatively diagnosed through radiographic examination and must be confirmed by histological examination. Radiographically, it appears as a lucency in the bone of varying size and features—sometimes it is a single, well-demarcated lesion whereas it often demonstrates as a multiloculated "soap bubble" appearance. Resorption of roots of involved teeth can be seen in some cases, but is not unique to ameloblastoma. The disease is most often found in the posterior body and angle of the mandible, but can occur anywhere in either the maxilla or mandible. Ameloblastoma is often associated with bony-impacted wisdom teeth—one of the many reasons dentists recommend having them extracted. Radiation is ineffective in many cases of ameloblastoma. There have also been reports of sarcoma being induced as the result of using radiation to treat ameloblastoma. Chemotherapy is also often ineffective. However, there is some controversy regarding this and some indication that some ameloblastomas might be more responsive to radiation that previously thought. While the Mayo Clinic recommends surgery for almost all ameloblastomas, there are situations in which a Mayo Clinic physician might recommend radiation therapy. These include malignancy, inability to completely remove the ameloblastoma, recurrence, unacceptable loss of function, and unacceptable cosmetic damage. In the case of radiotherapy, oncologists at the Mayo Clinic would use intensity-modulated radiotherapy. [READ THE REST OF THIS ARTICLE]

Ripple Rock was an underwater, twin-peaked mountain in the Seymour Narrows of the Discovery Passage in British Columbia, Canada, a part of the marine trade route from Vancouver and coastal points north. The nearest town was Campbell River. Only 2.7 meters (9 feet) underwater at low tide, it was a marine hazard, described by the explorer George Vancouver as "one of vilest stretches of water in the world." The first known large ship to fall prey to Ripple Rock was the sidewheel steamer Saranac in 1875, as it was heading north to Alaska. At least 20 large and 100 smaller vessels were badly damaged or sunk between then and 1958. At least 110 people drowned in these accidents. As early as 1931, a Marine Commission recommended removing Ripple Rock, but it was not until 1942 that the government authorized attempts to remove it. There was political opposition to the destruction of Ripple Rock, as some felt it would serve well as a bridge support to connect Vancouver Island to the mainland. The first attempts at planting explosive charges on Ripple Rock were made with floating drilling barges with the goal of blasting away the rock in pieces. The first, in 1943, was secured with six 3.8 cm steel cables attached to anchors that altogether weighed 998 metric tons. This approach was abandoned when one cable broke on average every 48 hours. Another attempt in 1945, involving two large overhead steel lines was similarly abandoned after only 93 (out of 1500 planned) controlled explosions were successful. In 1953, the National Research Council of Canada commissioned a feasibility study on the idea of planting a large explosive charge underneath the peaks by drilling vertical and horizontal shafts from Maud Island in the sound. Based on the study, this approach was recommended. Between November 1955, and April 1958, a three-shift operation involving an average of 75 men worked to build a 174 meter vertical shaft from Maud Island, a 762 meter horizontal shaft to the base of Ripple Rock, and two main 91 meter vertical shafts into the twin peaks, from which "coyote" shafts were drilled for the explosives. 1,270 metric tons of Nitramex 2H explosives were placed in these shafts, estimated at ten times the amount needed for a similar explosion above water. The explosion took place at 9:31:02 am on April 5, 1958. 635,000 metric tons of rock and water was displaced by the explosion, resulting in debris at least 300 meters in the air, falling on land on either side of the narrows. The blast increased the clearing at low tide to about 14 meters (45 feet). The Royal Canadian Mounted Police cleared the area of within 3 miles of the explosion, and the engineers and TV crew that witnessed the explosion were housed in a bunker. The explosion was noted as one of the largest non-nuclear planned explosions on record, though Soviet authorities reported a larger explosion in the Ural Mountains to carve a new channel for the Kolonga River and in China to open a copper mine. This is a National Historic Event in Canada. The Ripple Rock explosion was seen throughout Canada, live on CBC Television. It was one of the first live coast to coast television coverages of an event in Canada. [READ THE REST OF THIS ARTICLE]

Sea Fighter (FSF-1) is an experimental littoral combat ship under development (2005-2008) by the United States Navy. Its hull is of a small-waterplane-area twin-hull (SWATH) design, provides exceptional stability, even on rough seas. This is accomplished by placing most of the ship's displacement below the level of the waves (like a submarine) where all the kinetic energy of the sea surface is located. Conversely, ships with traditional hull designs have most of their displacement in the wave level of the sea, causing them to roll and pitch in the waves. Some of the aluminium panels have been prefabricated from aluminium extrusions using the innovative friction stir welding process. The ship can operate in both blue and littoral waters. For power, it can use either its dual gas turbine engines for speed or its dual diesel engines for efficient cruising. With twin gas turbine engines, twin water jets, and a streamlined hull, Sea Fighter is capable of speeds of 50 knots (90 km/h) and greater. It is designed to be a sea frame that can carry interchangeable mission modules resembling shipping containers. These modules allow it to be easily reconfigured to meet a variety of mission requirements, including mine warfare, anti-submarine operations, amphibious assault support, surface warfare, transport and logistical missions, cruise missile launch, and special forces interdiction operations. The mission modules are easily loaded and stored on Sea Fighter’s inner deck. Helicopters can land and launch on its deck. Smaller water craft can be carried and launched from its stern. The vessel is being developed under the program title Littoral Surface Craft-Experimental (LSC(X)) with a hull type designation Fast Sea Frame. The first vessel has been assigned the hull classification symbol FSF 1 and also has been referred to as the X-Craft. The vessel was designed by British company BMT Nigel Gee Ltd (formerly BMT Nigel Gee and Associates Ltd) who continue with a role in the development of the vessel. The Navy and Coast Guard are jointly exploring the possibility of further development of Sea Fighter-type vessels for use in patrolling U.S. coastal waters. With an effective range of 4,400 nautical miles (8,100 km) unrefueled the type could also be deployed quickly overseas for similar duties. Sea Fighter is expected to pave the way for a future line of fast, long range destroyers capable of travelling fast enough to avoid or out maneuver most of the current generation of torpedoes. Such vessels would be capable of crossing the Atlantic Ocean unrefueled, and have a very low radar signature, making detection difficult. They would be able to respond quickly to targets located by air or satellite and aggressively attack surface and submerged vessels using their speed to evade torpedo and missile attack. [READ THE REST OF THIS ARTICLE]

Transparent Factory is the English name of an automobile production plant owned by German carmaker Volkswagen, designed by architect Gunter Henn, and opened in 2002. The original German name is Gläserne Manufaktur (factory made of glass, literally vitreous manufactory). Both the German and English names are a word play on the double meaning of transparent and glassy, referring to both optical transparency and transparency of the production process. The main purpose of the factory is the assembly of Volkswagen's luxury sedan, the Phaeton. Spare capacity was also used to construct Bentley Continental Flying Spur vehicles destined for the European market until 2006, when all work was transferred to Bentley's plant in Crewe, England. The Transparent Factory is situated in the city center of Dresden, the 800-year-old German baroque city known for its arts and craftsmanship. It stands at the former location of the convention center. The factory's walls are made almost completely of glass. Its floors are covered entirely in Canadian maple. Its visitor-friendly layout was designed to accommodate up to 250 tourists per day. There are no smokestacks, no loud noises, and no toxic byproducts. Volkswagen have planted 350 trees in the grounds. The transparent factory handles final assembly only. Operations such as stamping and welding and the painting of the steel bodies take place in Zwickau. Painted bodies arrive at the factory by truck. The other 1200 parts and 34 preassembled components are shipped to a remote logistics center and are transferred from there to the factory via CarGoTrams that run on Dresden's public transport tracks. [READ THE REST OF THIS ARTICLE] is not affiliated with or endorsed by wikipedia. wikipedia and the wikipedia globe are registered trademarks of
article content reproduced in compliance with wikipedia's copyright policy and gnu free documentation license
view our privacy policy and terms of service here