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From today's featured article Serpins are a superfamily of proteins with similar structures that were first recognized for their protease inhibition activity and are found in all kingdoms of life. Their unusual mechanism of action irreversibly inhibits their target protease by undergoing a large conformational change to disrupt its active site. This contrasts with the more common competitive mechanism for protease inhibitors that bind to and block access to the protease active site. Protease inhibition by serpins controls an array of biological processes, including coagulation and inflammation, and consequently these proteins are the target of medical research. Their conformational-change mechanism confers certain advantages, but it also has drawbacks: serpins are vulnerable to mutations that can result in protein misfolding and the formation of inactive long-chain polymers. Serpin polymerization not only reduces the amount of active inhibitor, but also leads to accumulation of the polymers, which can cause cell death and even organ failure. (Full article...) Recently featured: Gregor MacGregor Tank Girl (film) Jumping Flash! Did you know... Dancing Shiva at Badami cave 1 ... that a pre-8th-century sculpture of a Tandava-dancing Shiva (pictured) can be found at the Badami cave temples, a UNESCO World Heritage Site candidate? ... that John Edgcumbe, a collateral descendant of Joshua Reynolds and co-editor of The Letters of Sir Joshua Reynolds, was Devon's first consultant haematologist? ... that Gregory the Great preached at San Menna? ... that SS officer Herbert Mehlhorn was involved in the camouflage of the mass graves of the Jewish victims at the Chełmno extermination camp? ... that a 1960 telecast of Night of the Auk was the first time William Shatner played a spacecraft crew member on television? ... that Benjamin D. Wood produced the first multiple choice test? ... that the parliament of the Republic of Carpatho-Ukraine met only once for a single day? ... that as a child, British chef Margot Henderson would cook garden snails with breadcrumbs for her parents' dinner parties?

In the news EgyptAir Airbus A320-200 involved in hijack An overpass collapses in Kolkata, India, killing at least 25 people. EgyptAir Flight 181 (aircraft pictured) is hijacked shortly after takeoff and forced to land at Larnaca International Airport in Cyprus. A suicide bombing in Lahore, Pakistan, targeting Christians celebrating Easter, kills at least 74 people and injures more than 340. The Syrian Army recaptures Palmyra from the Islamic State of Iraq and the Levant. In rowing, Cambridge win the 162nd Boat Race and Oxford win the 71st Women's Boat Race. Ongoing events: Zika virus outbreak Recent deaths: Hans-Dietrich Genscher Ronnie Corbett Zaha Hadid Imre Kertész On this day... April 2: World Autism Awareness Day; Easter Saturday (Western Christianity, 2016) Juan Ponce de León 1513 – Spanish conquistador Juan Ponce de León (pictured) reached Florida, becoming the first European known to do so, purportedly while searching for the Fountain of Youth in the New World. 1865 – American Civil War: On the third try, Union Army forces captured Petersburg, Virginia, although Confederate government officials and most of the remaining Confederate army were able to escape. 1911 – The Australian Bureau of Statistics conducted the country's first national census. 1982 – Argentine special forces invaded the Falkland Islands, sparking the Falklands War. 2006 – Over 60 tornadoes touched down in the central United States, killing 27 people and causing about US$1.1 billion in damages. More anniversaries: April 1 April 2 April 3

Today's featured picture The Australasian swamphen (Porphyrio melanotus) is a species of swamphen previously considered a subspecies of the purple swamphen. Members of this species live in groups of 3–12 individuals and are known to group together and shriek loudly to defend nests successfully during attacks; when unsuccessful at repelling predators, they may abandon their nest sites. The Australasian swamphen can be found in eastern Indonesia (the Moluccas, Aru and Kai Islands), as well as in Papua New Guinea, Australia, and New Zealand. Photograph: Toby Hudson Recently featured: Joseph Ducreux Paysandisia archon SMS Fürst Bismarck (1897)

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