Τρίτη 28 Φεβρουαρίου 2012

Science News SciGuru.com

Science News SciGuru.com

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Sperm do not function like olfactory cells, sperm cannot detect smells

Posted: 28 Feb 2012 06:58 AM PST

According to a 2003 study by German and American scientists, a component of the Lily of the Valley scent known as Bourgeonal alters the calcium balance of human sperm and attracts the sperm. The “Lily of the Valley phenomenon” – also the title of a book about smelling – was born as a result of this discovery that sperm act as swimming olfactory cells which follow a “scent trail” laid by the egg.

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Researchers explain optogenetic tool, Channelrhodopsin: Opening of the ion channel with light

Posted: 28 Feb 2012 06:49 AM PST

Controlling nerve cells with the aid of light: this is made possible by optogenetics. It enables, for example, the investigation of neurobiological processes with unprecedented spatial and temporal precision. The key tool of optogenetics is the light-activated protein channelrhodopsin. Biophysicists from Bochum and Berlin have now succeeded in explaining the switching mechanism through an interdisciplinary approach. The researchers report on their findings in the “Journal of Biological Chemistry”.

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BPH-703, Chemically Altered Osteoporosis Drug, may be Useful in Fighting Malaria

Posted: 28 Feb 2012 05:30 AM PST

BPH-703, a chemically altered osteoporosis drug, may be useful in treating malaria, researchers report in a new study. The researchers found the drug by screening a library of about 1,000 compounds used in previous efforts to target an important biochemical pathway (called isoprenoid biosynthesis) in cancer and in disease-causing organisms. The new drug lead, BPH-703, inhibits a key enzyme in isoprenoid biosynthesis that enables the malaria parasite to sustain itself and defend itself from the host immune system.

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Two Molecules communicate via single photons

Posted: 28 Feb 2012 05:13 AM PST

Scientists realize one of the most elementary and oldest “gedanken” experiments in modern physics, namely, excitation of a single molecule with a single photon. This paves the way for further investigations in which single photons act as carriers of quantum information to be processed by single emitters.

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Brain becomes less plastic and adaptable during depression

Posted: 28 Feb 2012 05:02 AM PST

During depression, the brain becomes less plastic and adaptable, and thus less able to perform certain tasks, like storing memories. Using a rat model, researchers at Karolinska Institutet have now traced the brain's lower plasticity to reduced functionality in its support cells. They  believe that learning more about these cells can pave the way for radical new therapies for depression.

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Race Determines Proper Dose of Common Antibiotic Azithromycin for Pregnant Women

Posted: 27 Feb 2012 08:14 PM PST

According to a new research, race is a key factor in properly dosing the antibiotic azithromycin in pregnant women. Azithromycin, one of the medicines most commonly prescribed to pregnant women, is used to treat bacterial infections, such as bronchitis, pneumonia, sexually transmitted diseases, and infections of the ears, skin and throat. Azithromycin works by stopping the growth of bacteria.

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Drug-Free Housing for Substance Abusers Leaving Detox Linked to Fewer Relapses

Posted: 27 Feb 2012 07:59 PM PST

New Johns Hopkins research suggests that providing housing contingent on drug abstinence to inner-city opioid abusers leaving a detoxification program significantly increases their chances of remaining drug-free six months later.

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Ultra-fast Outflows Help Monster Black Holes Shape Their Galaxies

Posted: 27 Feb 2012 02:08 PM PST

A curious correlation between the mass of a galaxy's central black hole and the velocity of stars in a vast, roughly spherical structure known as its bulge has puzzled astronomers for years. An international team led by Francesco Tombesi at NASA's Goddard Space Flight Center in Greenbelt, Md., now has identified a new type of black-hole-driven outflow that appears to be both powerful enough and common enough to explain this link.

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Antarctic salty soil sucks water out of atmosphere: Could it happen on Mars?

Posted: 27 Feb 2012 01:55 PM PST

The frigid McMurdo Dry Valleys in Antarctica are a cold, polar desert, yet the sandy soils there are frequently dotted with moist patches in the spring despite a lack of snowmelt and no possibility of rain.

A new study, led by an Oregon State University geologist, has found that that the salty soils in the region actually suck moisture out of the atmosphere, raising the possibility that such a process could take place on Mars or on other planets.

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Modified bone drug kills malaria parasite in mice

Posted: 27 Feb 2012 01:47 PM PST

A chemically altered osteoporosis drug may be useful in fighting malaria, researchers report in a new study. Unlike similar compounds tested against many other parasitic protozoa, the drug readily crosses into the red blood cells of malaria-infected mice and kills the malaria parasite. The drug works at very low concentrations with no observed toxicity to the mouse.

The study appears in the Proceedings of the National Academy of Sciences.

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Study shows how to rescue the immune system in compromised conditions

Posted: 27 Feb 2012 12:30 PM PST

In a study published in Nature Medicine, Loyola researchers report on a promising new technique that potentially could turn immune system killer T cells into more effective weapons against infections and possibly cancer. 

The technique involves delivering DNA into the immune system's instructor cells. The DNA directs these cells to overproduce a specific protein that jump-starts killer T cells -- immune system cells that attack cancer cells and pathogens. 

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Hyperactivity in brain may explain multiple symptoms of depression

Posted: 27 Feb 2012 12:22 PM PST

Most of us know what it means when it's said that someone is depressed. But commonly, true clinical depression brings with it a number of other symptoms. These can include anxiety, poor attention and concentration, memory issues, and sleep disturbances.

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Researchers Resolve Controversy Over Gallium Manganese Arsenide that Could Boost Spintronic Performance

Posted: 27 Feb 2012 12:14 PM PST

A long-standing controversy regarding the semiconductor gallium manganese arsenide, one of the most promising materials for spintronic technology, looks to have been resolved. Researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab)in collaboration with scientist from University of Notre Dame have determined the origin of the charge-carriers responsible for the ferromagnetic properties that make gallium manganese arsenide such a hot commodity for spintronic devices.

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Female sex hormones can weaken the ability of fish to protect themselves against environmental toxins

Posted: 27 Feb 2012 12:05 PM PST

It is well known that female sex hormones (oestrogens) that end up in rivers and lakes, primarily via spillage from sewers and livestock farming, pose a threat to the environment.

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Memory Formation Triggered by Stem Cell Development

Posted: 27 Feb 2012 12:00 PM PST

Researchers at the RIKEN-MIT Center for Neural Circuit Genetics have discovered an answer to the long-standing mystery of how brain cells can both remember new memories while also maintaining older ones.

They found that specific neurons in a brain region called the dentate gyrus serve distinct roles in memory formation depending on whether the neural stem cells that produced them were of old versus young age.

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Aurora-A Hinders Tumor-Suppressor to Allow Chemotherapy Resistance

Posted: 27 Feb 2012 11:55 AM PST

A protein abundantly found in treatment-resistant cancers holds an important tumor-suppressor out of the cell nucleus, where it would normally detect DNA damage and force defective cells to kill themselves, a team of scientists reports in the current Cancer Cell.

"Overexpression of Aurora Kinase-A in tumors has been correlated with resistance to DNA-damaging chemotherapy, but we haven't known how this occurs," said senior author Subrata Sen, Ph.D., professor in The University of Texas MD Anderson Cancer Center Department of Molecular Pathology.

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New research shows childhood adversity causes changes in genetics

Posted: 27 Feb 2012 11:08 AM PST

In a look at how major stressors during childhood can change a person's biological risk for psychiatric disorders, researchers at Butler Hospital have discovered a genetic alteration at the root of the association. The research, published online in PLoS ONE on January 25, 2012, suggests that childhood adversity may lead to epigenetic changes in the human glucocorticoid receptor gene, an important regulator of the biological stress response that may increase risk for psychiatric disorders.

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Targeted Drug Helps Leukemia Patients Who Do Not Benefit from Initial Therapy

Posted: 27 Feb 2012 10:51 AM PST

A new study has found that patients with chronic myeloid leukemia (CML) who have not responded to interferon treatments experience long-term benefits when they switch to the targeted drug imatinib. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the study indicates that imatinib is the treatment of choice for these patients.

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The poor, in fact, are less likely to sue their doctor

Posted: 27 Feb 2012 10:43 AM PST

Contrary to the common perception among physicians that poor people sue doctors more frequently, Ramon L. Jimenez from the Monterey Orthopaedic and Sports Medicine Institute and his team demonstrate that socioeconomically disadvantaged patients, in fact, tend to sue physicians less often. Their work suggests that this myth may exist because of subconscious prejudices or stereotypes that affect thinking and decision making without doctors being aware of it - a phenomenon known as unconscious bias. Dr.

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Metacognition - I know (or don't know) that I know

Posted: 27 Feb 2012 10:38 AM PST

At New York University, Sir Henry Wellcome Postdoctoral Fellow Dr Steve Fleming is exploring the neural basis of metacognition: how we think about thinking, and how we assess the accuracy of our decisions, judgements and other aspects of our mental performance.

Metacognition is an important-sounding word for a very everyday process. We 'metacognise' whenever we reflect upon our thinking process and knowledge.

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