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Tag: "concentrations" at biology news

Industrial contaminants spread by seabirds in High Arctic, new Canadian study shows

..., the researchers found. "The effect is to elevate concentrations of pollutants such as mercury and DDT to as much as 60 times that of areas not influenced by seabird populations," says team member John Smol, a biology professor at Queen's University and Canada Research Chair in Environmental Change. The multidisc...

Device traps, disables harmful bacteria

...ers on the ceiling of the pool room. They compared concentrations of total bacteria, culturable bacteria and airborn...one year apart, and found that the filters reduced concentrations of culturable bacteria by 69 and 80 percent during monitoring periods executed in respective years. ...

Insight into our sight: A new view on the evolution of the eye lens

...ty to precisely refract light, arise from the high concentrations of special proteins called crystallins found in lens cells. Fish, frogs, birds and mammals all experience image-forming vision, thanks to the fact that their eyes all express crystallins and form a lens; however, the vertebrates' nearest invertebrat...

Weight control protein may yield antiobesity drugs

...p a metabolic syndrome characterized by high blood concentrations of leptin, insulin, and lipids. They also develop ... Rui said. However, obese animals, with high blood concentrations of the hormone, often exhibit resistance to leptin's usual effects. As a result, leptin itself has p...

Gaining ground in the race against antibiotic resistance

...istance enzyme and grew the bacteria on increasing concentrations of antibiotics, it took only a few days of test tube evolution to increase drug resistance. Eventually, they found four mutations in the evolved enzyme that allowed the bacteria to survive on a drug dose 64 times higher than the dose that kills bacte...

NYU chemists use computer simulation to enhance understanding of DNA transcription

... three-dimensional zig-zag structures at high salt concentrations and "beads-on-a-string" structures at low salt, demonstrating that the structure of chromatin strongly depends on its salt environment. To Schlick and her colleagues, these results revealed that in a low-salt environment, linker DNAs in the array we...

Gradient guides nerve growth down spinal cord

...ther proteins, Wnt1 and Wnt5a are produced at high concentrations at the top of the cord and at consecutively lower levels farther down. They also found that motor nerves are guided by Wnts through a different receptor, called Ryk, that mediates repulsion by Wnts. Antibodies that blocked the Wnt-Ryk interaction bl...

Sensor web simulation investigates technique to improve prediction of pollution across the globe

...hould make observations. If a model forecasts high concentrations of CO, the sensor web's instruments can be commanded to make targeted observations of those locations. The actual sensor measurements can then be fed back into the computer model to improve the accuracy of the forecast. Talabac's team hopes to illust...

Water management in cells

...cell can regulate its volume by adjusting the salt concentrations in and around the cell. Exactly how this process w...r water can more easily respond to changes in salt concentrations and that volume changes are facilitated by the presence of specific channels that transport water. ...

Genetically modified maize not found in southern Mexico

...es in the United States that can test for very low concentrations of transgenic material in maize seeds. The researchers were looking for traces of two key transgenes ?one or both of which are found in all GM maize crops. Test results showed no evidence of the presence of either transgene from any of the seeds. "...

Does manganese inhaled from the shower represent a public health threat?

... In their analysis, Spangler and Elsner found that concentrations well below 0.5 milligrams might lead to brain injury. "Inhaling manganese, rather than eating or drinking it, is far more efficient at delivering manganese to the brain," said Spangler. "The nerve cells involved in smell are a direct pathway for tox...

Baby's genes affect mom's cholesterol levels

...proteins," notes Descamps. "In pregnant women, the concentrations of these lipoproteins are particularly very high a...d apolipoprotein E that are known to influence the concentrations of triglycerides and cholesterol in the general population. They found that when these polymorphisms...

NCAR analysis shows widespread pollution from 2004 wildfires

...earch (NCAR). The fires also increased atmospheric concentrations of ground-level ozone across much of the Northern ... last year. Because of the wildfires, ground-level concentrations of ozone increased by 25% or more in parts of the northern continental United States and by 10% as f...

Bacteria in Household Dust May Trigger Asthma Symptoms

...and bedding dust. Households with higher endotoxin concentrations experienced higher prevalence of respiratory sympt...tion analysis was performed to correlate endotoxin concentrations to specific health outcomes. “When we analyzed the dust samples, we found that kitchen and living r...

Modifications render carbon nanotubes nontoxic

...cal cell cultures are exposed to various forms and concentrations of toxins. In order to compare the toxicity of different compounds, scientists look for the concentration -- typically measured in parts per million or parts per billion -- of materials that lead to the death of 50 percent of the cells in a culture w...

Amphetamines reverse Parkinson's disease symptoms in mice

... -- normally thought to act by increasing dopamine concentrations in the brain ? correct the behavioral abnormalities associated with Parkinson's in mice devoid of the brain messenger. Dopamine normally acts on dopamine receptors ? protein switches on the surface of neurons -- to stimulate brain processes that affe...

Beach pollution is worst during new and full moon

...ing track of tidal patterns and analyzing them for concentrations of enterococci -- bacteria that allow scientists to estimate the risk of illness from swimming in marine waters. "This is the largest array of beaches examined at the same time for a similar pattern," says Alexandria Boehm, Ph.D., an environmental en...

Chernobyl: The true scale of the accident

... exposure, but, with the exception of a few areas, concentrations fall within safe levels. What is the extent of fo...lation in the aquatic food chain, though, elevated concentrations of radiocaesium were found in fish from lakes as far away as Germany and Scandinavia. Comparable lev...

Zinc supplements safe for HIV-infected children

...ed children. The CD4+ T lymphocytes and hemoglobin concentrations also were similar between the two study groups. Importantly, HIV-infected children who received zinc supplementation were less likely to get watery diarrhea. "Programs to increase zinc supplementation in populations with a high prevalence of HIV inf...

Fresh water affected by salt from deicing roads

...loride. In developed areas of Baltimore, chloride concentrations were already high enough to induce mortality in aq...cant that the long-term record shows that salinity concentrations are going up, even in places where the amount of salt applied has not increased. Concentrations are...

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