Archive for the 'News' Category

Researchers have now been able to sequence the entire Denisova genome using 10 milligram of a finger bone fragment that was found in the Denisova-Cave in Southern Sibiria. Photo by MPI for Evolutionary Anthropology)

From ScienceDaily

he Max Planck Institute for Evolutionary Anthropology, in Leipzig, Germany, has completed the genome sequence of a Denisovan, a representative of an Asian group of extinct humans related to Neandertals.

In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The DNA sequences showed that this individual came from a previously unknown group of extinct humans that have become known as Denisovans. Together with their sister group the Neandertals, Denisovans are the closest extinct relatives of currently living humans.

The Leipzig team has now developed sensitive novel techniques which have allowed them to sequence every position in the Denisovan genome about 30 times over, using DNA extracted from less than 10 milligrams of the finger bone. In the previous draft version published in 2010, each position in the genome was determined, on average, only twice. This level of resolution was sufficient to establish the relationship of Denisovans to Neandertals and present-day humans, but often made it impossible for researchers to study the evolution of specific parts of the genome. The now-completed version of the genome allows even the small differences between the copies of genes that this individual inherited from its mother and father to be distinguished.

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Every year, nearly $100 billion is invested in biomedical research in the US, all of it aimed at teasing apart the invisible bits of the body. Photo by Mauricio Alejo

By Jonah Lehrer from Wired

On November 30, 2006, executives at Pfizer—the largest pharmaceutical company in the world—held a meeting with investors at the firm’s research center in Groton, Connecticut. Jeff Kindler, then CEO of Pfizer, began the presentation with an upbeat assessment of the company’s efforts to bring new drugs to market. He cited “exciting approaches” to the treatment of Alzheimer’s disease, fibromyalgia, and arthritis. But that news was just a warm-up. Kindler was most excited about a new drug called torcetrapib, which had recently entered Phase III clinical trials, the last step before filing for FDA approval. He confidently declared that torcetrapib would be “one of the most important compounds of our generation.”

Kindler’s enthusiasm was understandable: The potential market for the drug was enormous. Like Pfizer’s blockbuster medication, Lipitor—the most widely prescribed branded pharmaceutical in America—torcetrapib was designed to tweak the cholesterol pathway. Although cholesterol is an essential component of cellular membranes, high levels of the compound have been consistently associated with heart disease. The accumulation of the pale yellow substance in arterial walls leads to inflammation. Clusters of white blood cells then gather around these “plaques,” which leads to even more inflammation. The end result is a blood vessel clogged with clumps of fat.

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By Emily Hanford from NPR

The lecture is one of the oldest forms of education there is.

“Before printing someone would read the books to everybody who would copy them down,” says Joe Redish, a physics professor at the University of Maryland.

But lecturing has never been an effective teaching technique and now that information is everywhere, some say it’s a waste of time. Indeed, physicists have the data to prove it.

When Eric Mazur began teaching physics at Harvard, he started out teaching the same way he had been taught.

“I sort of projected my own experience, my own vision of learning and teaching — which is what my instructors had done to me. So I lectured,” he says.

He loved to lecture. Mazur’s students apparently loved it, too. They gave him great evaluations and his classes were full.

“For a long while, I thought I was doing a really, really good job,” he says.

But then in 1990, he came across articles written by David Hestenes, a physicist at Arizona State. Hestenes got the idea for the series when a colleague came to him with a problem. The students in his introductory physics courses were not doing well: Semester after semester, the class average never got above about 40 percent.

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By Joseph R Mendelson III from American Scientist

I learned great and terrible lessons in my first year of graduate work in 1989—more than I expected and more than I realized at the time. My advisor at the University of Texas at Arlington, Jonathan Campbell, arranged for me to spend a field season in Guatemala surveying the amphibians and reptiles in the environs of a coffee plantation near Pueblo Viejo, in the Department of Alta Verapaz. I was going it alone with no Spanish language skills in the midst of a brutal civil war. But there had never been any herpetological work done in this particular part of the country, so I balanced my apprehension with a vision of myself following in the footsteps of the intrepid tropical natural historians and explorers whose monographs I was intensely studying.

During that summer I assembled a good collection of reptiles from Pueblo Viejo, but only a poor collection of amphibians. We all assumed at the time that the paltry representation of amphibian specimens was due to my incomplete skills; where I come from in southern California, reptiles are common and amphibians are scarce. Twenty years later, it is clear to all herpetologists that I had arrived on the scene of a massacre. That field trip launched my research career as an amphibian taxonomist and, indeed, I discovered my first species of frog new to science at Pueblo Viejo. Since then I have had the pleasure of discovering and naming dozens of new species, but some of them I “discovered” on museum shelves and not in the field. My finds had become extinct before they were even named. I chose to become a herpetologist, not a paleontologist, because I enjoy working afield with live animals. Recent reflection has forced me to reconsider my academic title. I am a forensic taxonomist.

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From TXCHNOLOGIST

In November 2011, NASA launched its biggest, most ambitious mission to Mars. The $2.5 billion Mars Science Lab spacecraft will arrive in orbit around the Red Planet this August, releasing a lander that will use rockets to control a slow descent into the atmosphere. Equipped with a “sky crane,” the lander will gently lower the one-ton Curosity rover on the surface of Mars. Curiosity, which weighs five times more than any previous Martian rover, will perform an unprecedented battery of tests for three months as it scoops up soil from the floor of the 96-mile-wide Gale Crater. Its mission, NASA says, will be to “assess whether Mars ever was, or is still today, an environment able to support microbial life.”

For all the spectacular engineering that’s gone into Curiosity, however, its goal is actually quite modest. When NASA says it wants to find out if Mars was ever suitable for life, they use a very circumscribed version of the word. They are looking for signs of liquid water, which all living things on Earth need. They are looking for organic carbon, which life on Earth produces and, in some cases, can feed on to survive. In other words, they’re looking on Mars for the sorts of conditions that support life on Earth.

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