تاریخ : سه شنبه 10 بهمن 1391 | 08:55 ب.ظ | نویسنده : osam

New work shows that bacteria reach miles into the atmosphere, bolstering the notion that microbes can affect precipitation and cloud formation.

Wikimedia, Jessie EastlandTen kilometers (more than 6 miles) into the atmosphere, a plethora of microbes is thriving, possibly affecting cloud chemistry and playing a role in atmospheric conditions, according to new research published today (January 28) in Proceedings of the National Academy of Sciences.

“It’s the most exciting paper I’ve seen published this year,” said Jessica Green, a microbial ecologist at the University of Oregon, who was not involved in the research. “It contributes significantly to the hypothesis that the atmosphere is alive. . . . The possibility of microbes being metabolically active in the atmosphere transforms our understanding of global processes.”

Previous research on snow and rainwater collected at high elevations had already established that bacteria in the air initiate moisture condensation that leads to precipitation. Some of these microbes secrete special proteins that allow them to initiate ice crystallization, which may affect weather by changing the temperature at which ice crystals form in the sky. But most microbe-rich precipitation was collected from the Earth, and may represent different bacterial communities than those in the atmosphere, which may have different properties for ice nucleation and cloud formation than those found in rain water, explained senior author Konstantinos Konstantinidis, a microbial genomicist at Georgia Tech.

To get a better glimpse of bacteria in the atmosphere—before they’ve fallen to earth— Konstantinidis and collaborators teamed up with NASA toTags


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تاریخ : شنبه 30 دی 1391 | 04:30 ب.ظ | نویسنده : ANVAR MAFIA20
تاریخ : شنبه 30 دی 1391 | 03:50 ب.ظ | نویسنده : ANVAR MAFIA20

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Researchers can work out the hair and eye color of ancient and recently deceased humans by looking only at DNA extracted from their skeletal remains, according to a study published this week (January 14) in Investigative Genetics.














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تاریخ : جمعه 29 دی 1391 | 11:38 ق.ظ | نویسنده : osam
                         تمام مقالات خارجی در عرض چند هفته ی دیگر ترجمه خواهند شد
person donating their DNA sequence anonymously for research purposes may in fact be identified by a few simple web searches, according to a

 paper published today (January 17) in Science. But rather than trying to protect anonymity, some scientists believe efforts should instead be focused on educating DNA donors and on legislating against the misuse of sequence data.

“The paper is a nice example of how simple it is to re-identify de-identified samples and that the reliance on de-identification as the mechanism of ensuring privacy and avoiding misuse is one that is not viable,” said Nita Farahany, a professor of law and research at Duke University in Durham, North Carolina, who was not involved in the study.

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تاریخ : جمعه 29 دی 1391 | 11:30 ق.ظ | نویسنده : osam

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ike humans, with their complement of microbes that aid in everything from immune responses to nutrition, plants rely on a vast array of bacteria

 and fungi for health and defense. Over the last decade, research has revealed many new functional aspects of the crosstalk between human-associated microbes and human cells, but plant biologists are only beginning to scratch the surface of the often surprising ways that soil microbiota impact plants, from underground fungus-wired alarm systems to soil bacteria that can trigger defensive plant behavior or even act as a sort of vaccine. But despite these benefits, microbes are still primarily thought of as harbingers of disease.
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تاریخ : جمعه 29 دی 1391 | 11:29 ق.ظ | نویسنده : osam


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Video games designed to tackle tough scientific problems are leading to breakthroughs in RNA structure, protein folding, genetic sequence alignment, and moreMarie Mole


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