We've all heard of Pavlov's dogs, the famous canines trained by Russian physiologist Ivan Pavlov to associate food with the sound of a bell. Now, scientists have found that bacteria may be capable of similar behavior--an ability never seen in such simple organisms.
Researchers already know that microbes can mount simple responses to changes in their environment, such as acidity fluctuations, by altering their internal workings. If the changes are regular enough, bacteria can respond ahead of time. But systems biologist Saeed Tavazoie of Princeton University wondered if microbes were capable of more sophisticated reasoning. Could they, for example, learn to match a signal that didn't occur regularly to a probable future event? If so, the bacterium could improve its chances of survival by turning on a preemptive response to that event.
Science & Technology
Recent data from the Cassini mission to Saturn have shed new light on the surface of the saturnian moon Iapetus, particularly the presence and movement of carbon dioxide.
A strange white dwarf star has been discovered in the constellation Ursa Major (Great Bear) 800 light-years away, which has a pulsating variety with carbon at its surface, not hydrogen and helium, which are usually found in such stars.
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| ©Lunarismaar |
| New class of star: An artist's impression of a carbon-rich white dwarf. Most light emitted by these hot stars is in the ultraviolet and blue part of the electromagnetic spectrum. |
On the sea ice 30 miles form the North Pole - Three broken bolts. A vital part of the first sustained effort to monitor big climate shifts at the top of the world was being threatened by three broken bolts.
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| ©New York Times |
| Broken bolts stalled efforts to retrieve instruments through a hole in the Arctic ice |
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| ©iStockphoto/Eric Delmar |
| New research on cane toads in Northern Australia has discovered a way to control the cane toad invasion using parasites and toad communication signals |
Professor Rick Shine from the University of Sydney has been studying the biology of cane toads, and will reveal his new research May 7 at the Academy of Science's peak annual event Science at the Shine Dome.
The radioactive carbon-14 produced by above-ground nuclear testing in the 1950s and '60s has helped researchers determine that the number of fat cells in a human's body, whether lean or obese, is established during the teenage years. Changes in fat mass in adulthood can be attributed mainly to changes in fat cell volume, not an increase in the actual number of fat cells.
Three hot-air balloons dropped asphalt shingles, lumber, sticks, leaves and pine needles onto a north Alabama landfill, so scientists at The University of Alabama in Huntsville could gather data needed to improve tornado warnings.
The payloads dropped by the balloons were similar to the types of debris thrown into the air by tornados that touch the ground. Scientists at UAHuntsville's Earth System Science Center hope the Doppler radar data collected will be a first step toward programming National Weather Service Doppler radar to recognize tornado debris, so more timely and precise tornado warnings might be issued.
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| ©Mariana Felix |
| UA Huntsville graduate students and staff attach a bundle of asphalt shingles to Randy Sedlak's balloon as part of an experiment to help scientists improve tornado forecasting. |
The payloads dropped by the balloons were similar to the types of debris thrown into the air by tornados that touch the ground. Scientists at UAHuntsville's Earth System Science Center hope the Doppler radar data collected will be a first step toward programming National Weather Service Doppler radar to recognize tornado debris, so more timely and precise tornado warnings might be issued.
Previous family-based research had linked a broad region on chromosome 4q with alcohol dependence (AD). A new study has found that nine of the single nucleotide polymorphisms (SNPs) -- DNA sequence variations -- in the 3' region of the tachykinin receptor 3 gene (TACR3), located within chromosome 4q, have a significant association with AD, particularly those with more severe AD, and co-existing cocaine dependence.
"We believe it is important to identify genes contributing to AD for two primary reasons," said Tatiana M. Foroud, director of the division of hereditary genomics at the Indiana University School of Medicine and first author of the study.
"First, better treatments can be developed which would improve the success rate for those wishing to end their AD," she said. "Second, being able to identify those at greater risk for AD at a young age would allow interventions to be initiated earlier, potentially reducing the likelihood that the individual will become AD."
"We believe it is important to identify genes contributing to AD for two primary reasons," said Tatiana M. Foroud, director of the division of hereditary genomics at the Indiana University School of Medicine and first author of the study.
"First, better treatments can be developed which would improve the success rate for those wishing to end their AD," she said. "Second, being able to identify those at greater risk for AD at a young age would allow interventions to be initiated earlier, potentially reducing the likelihood that the individual will become AD."
DNA analysis of residents of Druze villages in Israel suggests these ancient religious communities offer a genetic snapshot of the Near East as it was several thousands of years ago.
The Druze harbor a remarkable diversity of mitochondrial DNA types or lineages that appear to have separated from each other many thousands of years ago, according to a new study by multinational team, led by researchers at the Technion-Israel Institute of Technology Rappaport School of Medicine.
But instead of dispersing throughout the world after their separation, the full range of lineages can still be found within the small, tightly knit Druze population.
Technion researcher Karl Skorecki noted that the findings are consistent with Druze oral tradition suggesting the adherents came from diverse ancestral lineages "stretching back tens of thousands of years." The Druze represent a "genetic sanctuary" or "living relic" that provides a glimpse of the genetic diversity of the Near East in antiquity, the researchers write in the May 7th issue of the journal PLoS ONE.
The Druze harbor a remarkable diversity of mitochondrial DNA types or lineages that appear to have separated from each other many thousands of years ago, according to a new study by multinational team, led by researchers at the Technion-Israel Institute of Technology Rappaport School of Medicine.
But instead of dispersing throughout the world after their separation, the full range of lineages can still be found within the small, tightly knit Druze population.
Technion researcher Karl Skorecki noted that the findings are consistent with Druze oral tradition suggesting the adherents came from diverse ancestral lineages "stretching back tens of thousands of years." The Druze represent a "genetic sanctuary" or "living relic" that provides a glimpse of the genetic diversity of the Near East in antiquity, the researchers write in the May 7th issue of the journal PLoS ONE.
Most female frogs don't call; most lack or have only rudimentary vocal cords. A typical female selects a mate from a chorus of males and then --silently -- signals her beau. But the female concave-eared torrent frog, Odorrana tormota, has a more direct method of declaring her interest: She emits a high-pitched chirp that to the human ear sounds like that of a bird.
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| ©Albert Feng |
| O. tormota lives in a noisy environment on the brushy edge of streams in the Huangshan Hot Springs, in central China, where waterfalls and rushing water provide a constant din. |
