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New Reagents Available For Genomic Engineering Of Mouse Models To Understand Human DiseaseNew tools are now available for generating specifically targeted genetic mutations in bacteria, mammalian cells and mice. The new recombinase, Dre, is similar to its predecessor, Cre, but targets unique sites within DNA for recombination. It may be used in combination with currently available methods to produce more complex mouse models to understand disease.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 12:00 pm Think Zinc: Molecular Sensor Could Reveal Zinc's Role In DiseasesScientists have developed a new molecular sensor that can reveal the amount of zinc in cells, which could tell us more about a number of diseases, including type 2 diabetes. The research opens the door to the hidden world of zinc biology by giving scientists an accurate way of measuring the concentration of zinc and its location in cells for the first time.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 12:00 pm Millionths Of A Second Can Cost Millions Of Dollars: A New Way To Track Network DelaysComputer scientists have developed an inexpensive solution for diagnosing networking delays in data center networks as short as tens of millionths of seconds -- delays that can lead to multi-million dollar losses for investment banks running automatic stock trading systems.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 12:00 pm Tumors Feel The Deadly Sting Of NanobeesWhen bees sting, they pump poison into their victims. Now the toxin in bee venom has been harnessed to kill tumor cells. Researchers attached the major component of bee venom to nano-sized spheres that they call nanobees.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 12:00 pm The Science Of Longer Lasting LagerOne of the long standing problems in the drinks industry is how to prevent chemical processes in the drinks compromising their taste, quality and shelf life. In particular, riboflavin (vitamin B2) is responsible for driving photooxidation reactions that affect the flavour of many drinks and so they often have to be packaged in light-shielded containers. Now scientists have developed a way of removing riboflavin.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 12:00 pm Sandfish Tucks Legs And 'Swims' Like A Snake Under Desert SandA new study details how sandfish -- small lizards with smooth scales -- move rapidly underground through desert sand. In this first thorough examination of subsurface sandfish locomotion, researchers found that the animals place their limbs against their sides and create a wave motion like snakes to propel themselves through granular media.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 12:00 pm Light Shed On Cause Of Down Syndrome And Other Genetic DisordersScientists have a better understanding of what causes an abnormal number of chromosomes in offspring, a condition called aneuploidy that encompasses the most common genetic disorders in humans, such as Down syndrome, and is a leading cause of pregnancy loss.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 9:00 am Scientists Identify Stomach’s Timekeepers Of HungerScientists have identified cells in the stomach that time the release of a hormone that makes animals anticipate food and eat even when they are not hungry. The finding, which has implications for the treatment of obesity, marks a landmark in the decades-long search for the timekeepers of hunger. The work reveals what the stomach "tells" the brain.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 9:00 am New Analysis Details Devastating Toll Of Neglected Tropical Diseases In Sub-Saharan AfricaNew light has been shed on the toll that neglected tropical diseases take on sub-Saharan Africa, with an estimated 500 million people suffering from these debilitating and sometimes deadly diseases. Helminth infections account for approximately 85 percent of the NTD burden. Overall, the NTD burden may be equivalent to more than double that caused by tuberculosis and up to one-half of SSA's malaria disease burden.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 9:00 am World's Smallest Semiconductor Laser Heralds New Era In Optical ScienceResearchers have reached a new milestone in laser physics by creating the world's smallest semiconductor laser, capable of generating visible light in a space smaller than a single protein molecule.Source: ScienceDaily: Latest Science News | 31 Aug 2009 | 9:00 am UN seeks better data on hurricanes, droughts (AP)
Source: Yahoo! News: Science News | 31 Aug 2009 | 4:32 am Shuttle Discovery arrives at space station (AP)
Source: Yahoo! News: Science News | 31 Aug 2009 | 3:18 am Climate trouble may be bubbling up in far north (AP)
Source: Yahoo! News: Science News | 31 Aug 2009 | 3:03 am Himalayan nations hold first climate talks (AFP)
Source: Yahoo! News: Science News | 31 Aug 2009 | 2:55 am The Nation's Weather (AP)AP - High pressure was forecast to bring cooler than normal temperatures to the Central U.S., while wet weather was expected to persist in the East on Monday.Source: Yahoo! News: Science News | 31 Aug 2009 | 2:49 am As hybrid cars gobble rare metals, shortage looms (Reuters)
Source: Yahoo! News: Science News | 31 Aug 2009 | 2:03 am Shuttle Discovery Marks Silver Anniversary With Space Station Docking (SPACE.com)SPACE.com - As space shuttle Discovery neared the International Space Station (ISS) on Sunday evening, its crew first caught sight of the sun's glare bouncing off eight pairs of solar arrays. The reflection spanned both space and time, as it hearkened back to Discovery's maiden launch 25 years ago on a six-day mission then to test fly a large, lightweight solar wing.Source: Yahoo! News: Science News | 31 Aug 2009 | 1:46 am India 'terminates' Moon missionIndia's space agency calls off its inaugural moon mission, a day after losing all contact with the orbiting satellite.Source: BBC News | Science & Environment | UK Edition | 30 Aug 2009 | 11:50 pm Shuttle Discovery Arrives at Space Station (SPACE.com)SPACE.com - After a two-day orbital chase, space shuttle Discovery linked up with the International Space Station late Sunday to deliver a new crewmember and a cargo pod full of vital supplies.Source: Yahoo! News: Science News | 30 Aug 2009 | 10:46 pm As hybrid cars gobble rare metals, shortage looms (Reuters)
Source: Yahoo! News: Science News | 30 Aug 2009 | 9:52 pm Typhoon brings heavy wind, rain to eastern Japan (AFP)
Source: Yahoo! News: Science News | 30 Aug 2009 | 8:49 pm Space shuttle reaches space station for 9-day stayCAPE CANAVERAL, Florida (Reuters) - U.S. space shuttle Discovery arrived at the International Space Station Sunday with food, equipment and new lab gear for the orbital outpost.Source: Reuters: Science News | 30 Aug 2009 | 8:30 pm Shuttle Discovery arrives at ISSSpace shuttle Discovery arrives at the International Space Station for a nine-day stay, carrying scientific equipment.Source: BBC News | Science & Environment | UK Edition | 30 Aug 2009 | 7:54 pm Wikipedia to Color Code Untrustworthy Text
Starting this fall, you’ll have a new reason to trust the information you find on Wikipedia: An optional feature called “WikiTrust” will color code every word of the encyclopedia based on the reliability of its author and the length of time it has persisted on the page. More than 60 million people visit the free, open-access encyclopedia each month, searching for knowledge on 12 million pages in 260 languages. But despite its popularity, Wikipedia has long suffered criticism from those who say it’s not reliable. Because anyone with an internet connection can contribute, the site is subject to vandalism, bias and misinformation. And edits are anonymous, so there’s no easy way to separate credible information from fake content created by vandals. Now, researchers from the Wiki Lab at the University of California, Santa Cruz have created a system to help users know when to trust Wikipedia—and when to reach for that dusty Encyclopedia Britannica on the shelf. Called WikiTrust, the program assigns a color code to newly edited text using an algorithm that calculates author reputation from the lifespan of their past contributions. It’s based on a simple concept: The longer information persists on the page, the more accurate it’s likely to be. Text from questionable sources starts out with a bright orange background, while text from trusted authors gets a lighter shade. As more people view and edit the new text, it gradually gains more “trust” and turns from orange to white. “They’ve hit on the fundamentally Darwinian nature of Wikipedia,” said Wikipedia software developer and neuroscientist Virgil Griffith of the California Institute of Technology, who was not involved in the project. “Everyone’s injecting random crap into Wikipedia, and what people agree with more often sticks around. Crap that people don’t like goes away.” WikiTrust has been available as a MediaWiki extension since November 2008, meaning that anyone who runs a wiki site has been free to download the code and add the feature to their site. Now bigwigs at the WikiMedia Foundation, the non-profit organization that manages Wikipedia, have decided to the add the WikiTrust feature to the entire encyclopedia. Starting sometime this fall, registered Wikipedia users will be able to click on a “trust info” tab and view the color-coded text.
“Online collaboration is becoming more and more central to the way in which knowledge is created and assembled worldwide,” said computer scientist Luca de Alfaro, who runs the UCSC Wiki Lab and led the WikiTrust project. “There are more and more services that simply cannot exist without some notion of user reputation and trust in the content.” De Alfaro first came up with the idea for a wiki reputation system when he became frustrated with the amount of vandalism on his own wiki site. “I started to think there has to be some way to give people an incentive to behave in a more productive way,” he said. Collaborative websites such as Amazon.com and eBay already have reputation systems based on user ratings. Many people proposed creating a similar system for Wikipedia, but de Alfaro feared that user-generated ratings might upset Wikipedia’s collaborative atmosphere. He also didn’t want to create more work for editors. “If something works as well as Wikipedia,” de Alfaro said, “you think very hard before proposing to modify it in such a way that everybody has to give comments on everybody else.” Since Wikipedia already keeps track of every revision, de Alfaro realized he could use that data to create a reputation system independent of human input. “Machines should work for humans and not the other way around,” he said. “So if you can get information without bothering people, via clever algorithms, this is much better.”
Based on an person’s past contributions, WikiTrust computes a reputation score between zero and nine. When someone makes an edit, the background behind the new text gets shaded orange depending on their reputation: the brighter the orange, the less “trust” the text has. Then when another author edits the page, they essentially vote on the new text. If they like the edit, they’ll keep it, and if not, they’ll revert it. Text that persists will become less orange over time, as more editors give their votes of approval. “We try to predict when things are going to be deleted,” Adler said. “We want words that are going to be deleted to have a low trust, and words that are not going to be deleted to have a high trust.” But some critics think there may be hurdles to running the trust tool over the entire site. “This isn’t a trivial web architecture design and implementation issue,” said computer scientist Ed Chi of the Palo Alto Research Group, who studies Wikipedia and social cognition. Since WikiTrust assigns a reputation score to every word in every article, running the program in real time will demand significant processing power and several terabytes of extra disk space. But Wiki Lab researchers say they’re already working on making the program more efficient. Using the first version of WikiTrust, it took a regular computer 20 days to process five years of Wikipedia revision data. The latest edition cuts that time to four days, and it can calculate trust ratings for 30 to 40 revisions per second. “That’s on a single machine,” Adler said. “So it’s very practical for us to keep up with Wikipedia.” In addition, because the product hasn’t been tested in large numbers of real users, Chi said he’s not convinced that users will find it helpful. Although his reasearch group had similar ideas for a reputation system in Wikipedia, Chi said they decided not to pursue the iea. “I wasn’t sure how well it really would work with ordinary users, in terms of their increased ability to detect trust problems and its interference with actual reading tasks,” he said. The Wiki Lab researchers also worried about their product detracting from the Wikipedia experience, so they designed it to be as unobtrusive as possible. Because too much orange text would turn people off, they balanced the need to flag questionable text with the need to keep the page readable. They also hid the gadget in a tab at the top of the screen, so if you don’t want to bother with trust ratings, you don’t have to click on the “trust info” tab. And don’t go hunting for your own orange ratings: The team decided not to display user reputation to avoid discouraging new users. “Even if you’re a wonderful biologist,” de Alfaro said, “if you haven’t written very much at all on Wikipedia, your reputation will be low.” WikiTrust can detect most types of questionable content. But when asked whether his gadget measures “truth” on Wikipedia, de Alfaro hesitated. WikiTrust determines trustworthiness based on how many people agree with a particular passage of text, he said, but majority approval doesn’t guarantee truth. “If 20 people are all biased in one way, our tool does not know it,” de Alfaro said. “Our tool can simply measure consensus.” Adler offers a hypothetical example. “What if Wikipedia was dominated by Nazis?” he said. “Whatever you say about the Holocaust, they’re going to revert you, and then other people are going to come and support those edits rather than your edits.” In that case, WikiTrust would start flagging your Holocaust content as unreliable—no matter how accurate it was. Trial by consensus sounds sketchy, but majority opinion has nearly always dictated society’s definition of truth. A 15th century encyclopedia would have insisted that the sun revolves around the earth. The 1911 edition of the Encyclopedia Britannica asserted that bacteria causes the flu, since viruses hadn’t been discovered yet. So perhaps it’s not a question of whether to trust consensus. Rather, whose consensus do you want to trust: a handful of experts, or thousands of anonymous internet users and a clever computer algorithm? Image 1: Flickr/bastique. Image 2: Screenshot of a Wikipedia page using WikTrust; questionable text appears orange. Courtesy UCSC Wiki Lab. This story was adapted from a feature by Hadley Leggett published in Science Notes, the annual publication of the UCSC Science Communication Program. See Also:
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Source: Wired: Wired Science | 30 Aug 2009 | 6:00 pm Window on the cosmosShortlisted images in this year's Astronomy Photographer of the Year competition organised by the Royal Observatory, Greenwich
Source: Science news, comment and analysis | guardian.co.uk | 30 Aug 2009 | 5:05 pm Power releaseFreeing up blocked renewable energy projectsSource: BBC News | Science & Environment | UK Edition | 30 Aug 2009 | 2:58 pm Gold nanotech breath test may show lung cancer earlyLONDON (Reuters) - A sensor made with gold nanoparticles can detect lung cancer in a patient's breath and may offer a diagnosis before tumors show up on an x-ray, Israeli scientists said on Sunday.Source: Reuters: Science News | 30 Aug 2009 | 11:01 am Contact lost, India terminates first moon missionBANGALORE, India (Reuters) - India terminated its first mission to the moon Sunday, a spokesman for the national space agency said, a day after scientists lost all contact with an unmanned spacecraft orbiting the moon.Source: Reuters: Science News | 30 Aug 2009 | 7:51 am
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The Wiki Lab built its trust tool around the principle that Wikipedia pages tend to improve over time, or at least to move toward consensus. You can measure an author’s trustworthiness by looking at how long his or her edits persist over time, said UCSC graduate student Bo Adler, who developed WikiTrust with de Alfaro and graduate student Ian Pye. “When you add something to Wikipedia and it lasts a long time, you did a good job,” Adler said. “If it gets erased right away, you did a bad job.”