One of astronomy's big questions is why galaxies forming as recently as 1 billion years after the Big Bang contain so much dust. The leading hypothesis is that supernovae, stars that explode at the end of their lives, contain large amounts of metal-enriched material that, in turn, harbors key ingredients of dust, like silicon, iron and carbon.
Montreal, April 14 2009 – Begin treatment as early as possible: this general common sense rule seems to apply to most diseases except HIV-AIDS, which is only treated once a certain number of immune cells called "CD4+" cells have disappeared. The results of a North American study, which involved the team of Dr. Marina Klein of the Research Institute of the MUHC, run contrary to this consensus. The findings show that the risk of death in seropositive patients decreases by 69% to 94% if they start treatment earlier than officially recommended.
This study, which was recently published in the New England Journal of Medicine, could have considerable influence on medical practice.
UPTON, NY -- By creating a "family tree" of genes expressed in one form of woody plant and a less woody, herbaceous species, scientists at the U.S. Department of Energy's Brookhaven National Laboratory have uncovered clues that may help them engineer plants more amenable to biofuel production. The study, published in the April 2009 issue of Plant Molecular Biology, also lays a foundation for understanding these genes' evolutionary and structural properties and for a broader exploration of their roles in plant life.
Extensive death of nerve cells leads to severe dementia in patients with Alzheimer's disease. Until now, it has only been possible to investigate the neuronal devastation in post mortem animal models, and by using complicated methods. Researchers at the German Center for Neurodegenerative Disease at Ludwig-Maximilians-Universitaet (LMU) Muenchen, headed by Professor Christian Haass, have now successfully observed this demise of nerve cells by life imaging. The scientists inserted a gene into zebrafish that leads to a severe form of Alzheimer's in humans.
Nerve signals that tell the brain that we are being slowly stroked on the skin have their own specialised nerve fibres in the skin. This is shown by a new study from the Sahlgrenska Academy, University of Gothenburg, Sweden. The discovery may explain why touching the skin can relieve pain.
The specialised nerve fibres in the skin are called CT nerves (C-tactile) and they travel directly to the areas in the brain that are important in the emergence of feelings.
In 2005 researchers at the University of Gothenburg and Stockholm University discovered a new species of seaweed. The species, which was named Fucus radicans, evolved from a bladder wrack (Fucus vesiculosus) ancestor from the Baltic Sea. Detailed studies of Fucus radicans show that, from an evolutionary perspective, it was formed extremely rapidly: the species was formed less than 2,500 years ago, and probably as recently as about 400 years ago. This discovery is one of few examples of extremely rapid species formation. The results also show that new species can also be formed in the relatively young and species-poor Baltic Sea.
Routine screening for coronary artery disease in type 2 diabetes patients with no symptoms of angina or a history of coronary disease is unnecessary and may lead initially to more invasive and costly heart procedures, according to researchers at Yale School of Medicine. They report their findings in the April 15 Journal of the American Medical Association.
"Patients with type 2 diabetes with no symptoms who are feeling well can generally be managed effectively with preventive therapies such as lipid-lowering drugs, blood pressure medication, aspirin and diabetes treatment," said Lawrence Young, M.D., professor of medicine at Yale School of Medicine.
Ann Arbor, MI--Patients with a rare, blinding eye disease saw their vision improve after treatment with drugs to suppress their immune systems, according to researchers at the University of Michigan Kellogg Eye Center. Because autoimmune retinopathy (AIR) is difficult to diagnose, the biggest challenge now is to find biologic markers that identify patients who can benefit from treatment.
Fast food and soft drinks may be making children fatter but they also make them happy. Programs aimed at tackling childhood obesity, by reducing children's consumption of unhealthy food and drink, are likely to be more effective if they also actively seek to keep children happy in other ways, according to Professor Hung-Hao Chang from National Taiwan University and Professor Rodolfo Nayga from the University of Arkansas in the US. Their findings are published in Springer's Journal of Happiness Studies.
COLUMBUS, Ohio – New research shows that human teeth lost some enamel hardness after the application of several different products used in the home to whiten teeth. The study suggests that future generations of such products might be reformulated in an effort to reduce these side effects.
The researchers noted that teeth typically can restore their previous hardness after losing small amounts of enamel calcification. But this is the first study to show at a nanometer scale – measuring in billionths of a meter – how human teeth are affected by the popular home whiteners.
An invasion of soybean aphids poses a problem for soybean farmers requiring application of pesticides, but a team of Penn State entomologists thinks a careful choice of nitrogen-fixing bacteria may provide protection against the sucking insects.
Soybeans are legumes, plants that can have a symbiotic relationship with nitrogen-fixing bacteria -- rhizobia -- and therefore do not need additional nitrogen fertilizer. Each type of legume -- peas, beans, lentils, alfalfa -- have their own rhizobia.
"Soybeans are from Asia and so there were originally no nitrogen-fixing bacteria that would colonize soybeans in U.S. soils," said Consuelo De Moraes, associate professor of entomology. "The rhizobia had to be transferred here."
Although more than three million high school seniors take standardized college admissions tests like the SAT "it is well known by educational researchers that high-school grades are the best indicator of student readiness for college, and standardized admissions tests are useful primarily as a supplement to the high-school record," according to Richard C. Atkinson in a speech to be presented April 15, 2009 at the American Educational Research Association's 90th annual meeting in San Diego.
In May 2008 the island of Guam became a living laboratory for scientists as they attached acoustic equipment to coconut trees in order to listen for rhinoceros beetles. A grant from USDA IPM allowed Richard Mankin, a recognized world-class expert on acoustic detection of insects, to travel to Guam to collaborate with island scientists on the Guam Coconut Rhinoceros Beetle Eradication Project. The results of this research were recently published in the journal Florida Entomologist.
