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Tag: "smaller" at biology news

Study finds evolution doesn't always favor bigger animals

...rtant in determining whether animals get bigger or smaller over time," added Hunt, now a curator at the Natio...lder environments. The reason: Bigger animals have smaller surface to volume ratios and can more effectively conserve heat in cold environments. Similarly, sma...

Aggression-related gene weakens brain's impulse control circuits

...rsion ?especially males ?tended to have relatively smaller emotion-related brain structures, a hyperactive alarm center and under-active impulse control circuitry. The study identifies neural mechanisms by which this gene likely contributes to risk for violent and impulsive behavior through effects on the de...

Engineered mouse mimics cognitive aspects of schizophrenia

...that is involved in the cognitive deficits is much smaller in rodents than in primates. Some of the cognitive symptoms such as hallucinations or delusions are impossible to address. "However, rodent models have the advantage of allowing direct tests of cause-effect relationships for specific aspects of the...

Scientists discover that widely available drug also helps fight kidney disease

...azed," said Weimbs. "The kidneys were smaller, had smaller cysts and had retained their function." "We have known the genetic mutations that cause PKD for over a decade," explained Weimbs. "The genetic mutations are located in the gene for the polycystin-1 protein. Unfortunately, the function of polycystin-...

Fertility drugs given 'all-clear' in new study

...he fetus." The study contradicts an earlier, much smaller study linking letrozole to increased rates of inherited malformations. This study led to widespread concern about the use of letrozole, a drug which has been widely used in the treatment of infertility in recent years. "There were several methodolog...

New University of Toronto research a 'pore' excuse for engineering

...uld help satisfy society's never-ending hunger for smaller digital devices and cellphones, and could even lead to new methods for delivering medications via skin patches. The material, known as periodic mesoporous organosilica (PMO), is a thin film interspersed with pores just two-billionths of a metre acro...

Virginia Tech scientists develop process for creating biocompatible fibers

...atural compound into a sub micron fiber ?100 times smaller than a human hair. "It is the first demonstration that electrostatic spinning, or electrospinning, a polymer processing technique, can be used with a small molecule to produce a fiber. "Clothing fibers such as polyesters and nylons are composed of la...

Nanotechnology may find disease before it starts

...iopsy in many cases," Liu said. Nanoparticles are smaller than any cell in the human body, so they may pass through the walls of the leaky blood vessels, or capillaries, of tumor tissue and actually infiltrate the tumor. "Until now, nobody knew what these particles would do in the blood," Rosol said. "But ...

Antioxidant selenium offers no heart-disease protection

...r. "Our results extend previous research based on smaller intervention trials focusing on cardiovascular risk factors," said Stranges. "Our findings are consistent with those from previous studies that have shown no beneficial effect of selenium supplementation in combination with other antioxidants on the...

'Bad' enzymes may wear white hats after stroke

...iven immediately following the stroke, rats showed smaller areas of brain damage. Injections given at three days had no effect, but those given at seven days or 14 days led to more extensive brain damage, compared with rats that did not receive an inhibitor. The team also looked for MMPs within the brains o...

Genetic and environmental influences on alcohol consumption among rhesus monkeys

...s effect ?while statistically significant ?is much smaller than additive genetic effects. "Identifying a genetic component to alcohol consumption in this important animal model is a precursor to searching for the specific regions of the genome for genes that influence alcohol consumption," said Lorenz. "Ma...

MIT chemist discovers secret behind nature's medicines

...ids was substituted with a much shorter one. That smaller substitute leaves more room in the active site -- ...te difference in their structures. But it's just a smaller amino acid change in the active site. Things are usually not this simple, but there's an elegant bea...

Ultrasounds show mothers' drinking shrinks fetal brain

...aled that fetuses of the continuing drinkers had a smaller ratio of head-to-abdominal circumference, which indicates reduced skull growth. They also had smaller measures of the cerebellum, a region of the brain involved in many mental, motor and sensory tasks. ...

Duke to test bird flu vaccine dosing

...ccine, we can create a stronger immune response to smaller doses of the vaccine," said Emmanuel Walter, M.D.,...h Consortium and leader of the Duke study. "If the smaller dose stimulates immunity against the virus, then more people could be immunized with existing suppli...

Rare Tibetan antelope listed as endangered

... from outside the body. As technology enabled ever smaller ultrasound arrays, the researchers engineered probes that could fit inside catheters threaded through blood vessels to image the vasculature and heart from the inside out. The current advance relies on 500 tiny cables and sensors packed into a tube ...

3D ultrasound device poised to advance minimally invasive surgery

... from outside the body. As technology enabled ever smaller ultrasound arrays, the researchers engineered probes that could fit inside catheters threaded through blood vessels to image the vasculature and heart from the inside out. The current advance relies on 500 tiny cables and sensors packed into a tube ...

Overfishing in inland waters reduces biodiversity and threatens health

...es are often successively replaced in the catch by smaller ones. At the same time, some fish populations respond to fishing pressure with reductions in mean size at maturation. Allan and colleagues identify two main types of overfishing. One leads to marked declines in catch per unit effort and size of indi...

Picking particles faster than one at a time

...entation program was used to pick particles from a smaller and more difficult molecule, a convex or "boat-shaped" enzyme labeled TPP-II, isolated from the fruit-fly. Although an initial comparison between manual selection and automatic selection indicated that 15 percent of the program's nominations were fal...

NASA's AURA satellite peers into Earth's ozone hole

...e hole that developed over Antarctica this year is smaller than in previous years. NASA's 2005 assessment of the size and thickness of the ozone layer was the first based on observations from the Ozone Monitoring Instrument on the agency's Aura spacecraft. Aura was launched in 2004. This year's ozone hole...

Dog genome sequenced

...dimorphism seems to have evolved as females became smaller than males due to natural selection for optimal size," Lark explains. "This is consistent with our finding that a variant on the X chromosome plays a role in skeletal size determination." ...

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