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Tag: "population" at biology news

Picky female frogs drive evolution of new species in less than 8,000 years

...s, this behavior created a reproductively isolated population - essentially a new species - that is unable to ma...ars to have occurred in the contact region where a population of the southern lineage had become isolated from the rest of its lineage and had developed a prefere...

Volunteers sought for avian flu vaccine study

...virus will evolve to spread easily among the human population and become a global pandemic,"said Edwards, professor of Pediatric Infectious Diseases and vice chairof clinical research in the Department of Pediatrics. "Developing an effective vaccine is our best defense. The elderly, in particular, could be at...

'License to kill' enables powerful immune attack cells in mice

... bone marrow, leading to replacement of the entire population approximately once a week. Scientists led by Wayne M. Yokoyama, M.D., the Sam J. Levin and Audrey Loew Levin Professor of Research in Arthritis, and professor of medicine and of pathology and immunology, discovered through experiments in mice that t...

Costly breeding programs for endangered species pay off

...ations were less likely to go extinct or to suffer population crashes than were the populations that had undergone limited inbreeding. "The benefits of maximum-avoidance inbreeding were difficult to detect as long as the populations remained captive," said Meffert. "It's not clear why this is the case, but it ...

Continued reduction in the number of drug-related deaths in the UK

...highest annual drug-related death rate per 100,000 population (21.8), followed by Liverpool (15.8), and Blackpool & the Fylde (11.1). Of these five areas, only Liverpool showed an increase over 2003 (up from 7.4). Compared with the same period in 2003, the following jurisdictions reported a notable reduc...

Emerald Spectre haunts Ontario's ash forests

...s the apparently successful eradication of a borer population that was introduced into Maryland and, subsequently, into Virginia in a shipment of infected nursery saplings from Michigan. Officials destroyed the saplings as well as all ash trees within a kilometre of each infected site. "The success in Maryland...

New study shows measles immunization may prevent fatal brain infection

... of measles during the 1989-1991 resurgence in the population with the highest risk for SSPE, namely children under the age of five, or because wild-type viruses of the genotype identified are more likely to cause SSPE. The measles vaccine is known to be highly effective. Two doses provide immunity to 99 perc...

Preventing a pandemic: Study suggests strategies for containing a flu outbreak

...ife Sciences, at Science. A rural Southeast Asian population is a likely place for the new strain to emerge, so...Thailand. With this information, they simulated a population of 500,000 in which individuals mixed in a variety of settings, including households, household clus...

Gene therapy reverses genetic mutation responsible for heart failure in muscular dystrophy

...scle cell. Because 30 percent to 40 percent of the population has antibodies to human AAVs, there is always the possibility that the effectiveness of this form of gene therapy may be blunted by a host immune response. However, Dr. Xiao is optimistic that will not be the case. "The AAV-8 we used in this study w...

Amphetamines reverse Parkinson's disease symptoms in mice

...res are expected to rise as the average age of the population increases. Symptoms of the disease include tremors, slow movement or an inability to move, rigid limbs and a shuffling gait. Progression of the disease also leads to severe impairment in cognitive function. Dopamine replacement therapy which involve...

Agricultural workers at increased risk for infection with animal flu viruses

...as not appeared in the United States in any animal population or in humans. ...

Plant genes identified that can form basis for crops better adapted to environmental conditions

...friendly, sustainable agriculture in a world whose population is growing while the land available for agriculture is diminishing. Tom Beeckman is in charge of the root development group in the VIB Department of Plant Systems Biology, which is under the direction of Dirk Inz (for more info, see: www.vib.be/Rese...

Prenatal exposure to marine toxin causes lasting damage

...ke sure that the most sensitive parts of the human population are protected from toxic exposure to domoic acid," he continued. The researchers reported their findings in a forthcoming special issue dedicated to research on marine toxins of Neurotoxicology and Teratology. In 1987, more than 100 people in Can...

Chernobyl: The true scale of the accident

...rofound negative health impacts to the rest of the population in surrounding areas, nor have we found widespread...kelihood of decreased fertility among the affected population has been found, nor has there been any evidence of increases in congenital malformations that can be...

Cornell finds natural selection in humans

...In general, negative selection eliminates from the population very harmful changes to proteins that kill or stop reproduction. But mutations that have led to slightly deleterious versions of the gene -- mutations that may cause disease or only slightly reduce the average number of children left by those that ca...

Regenerating worms help elucidate stem cell biology

...k they probably have a lot to teach us about how a population of stem cells is being regulated in vivo, rather than in a Petri dish," he said. So Sánchez Alvarado and his colleagues set out to understand exactly how neoblasts carry out the remarkable maintenance and recreation of the varied tissues that ma...

New vaccine platform may fight infections with causes from influenza to bioterrorism

...st pneumocystis pneumonia in mice lacking the same population of immune cells that HIV destroys in humans. The v...th compromised immune systems continues to rise, a population that cannot be protected against polio, the flu and other infectious agents with existing vaccines t...

Student scientists create living bacterial photographs

...urs of exposure (the time it takes for a bacterial population to grow and fill the Petri dish), the light projector is removed. What's left is a living photograph. Bacteria in the lighted regions of the Petri dish don't produce the pigment and appear light. Those in the dark regions produce pigment and appe...

Oil spills and climate change double the mortality rate of British seabirds

... years, has had a negative effect on the guillemot population of Skomer Island. Professor Tim Birkhead of the ...said: "Prior to our investigation of the guillemot population of Skomer Island, the impact of oil pollution on seabird mortality rates at a particular colony was ...

Scientists determine structure of enzyme that disrupts bacterial virulence

...the ability of certain bacteria to sense their own population growth ?the key to triggering genes that can increase virulence. In order to sense the size of their own populations, certain bacteria produce small molecules called N-acyl homoserine lactones. The concentrations of these lactones increase along wit...

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