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Tag: "hypothesis" at biology news

Fish evolve a longer lifespan by evolving a longer reproductive period, researchers find

...ce ?Biology. The study supports the controversial hypothesis that natural selection ?the process in nature by which only organisms best adapted to their environment tend to survive and pass on their genetic characters in increasing numbers to succeeding generations ?introduces changes in only a specific segmen...

Machinery of the 'marijuana munchies'

...luded that their findings "are consistent with the hypothesis that the integration of endocannabinoid and leptin signaling regulates the excitability of neurons on appetite-related circuits." They also wrote that "the cellular mechanisms of recently developed antiobesity drugs, such as rimonabant, may include ...

Model identifies genes that induce normal skin cells to become abnormal

...mune system. The group's current study tested the hypothesis that the microenvironment of metastatic melanoma c... metastatic melanoma cells, further supporting the hypothesis that "epigenetic" induction of changes in skin cell gene expression is directly related to exposure ...

Ancient trans-Atlantic swarm brought locusts to the New World

...o power a trip lasting several days. "One unlikely hypothesis is that while the locusts were flying across, as their brethren died and landed in the ocean, they formed huge floating mats of dead locusts," says Lovejoy. "The other locusts would land on these mats, rest and feed on the dead bodies, then take off ...

Same-sex mating by fungi spawned infection outbreak, evidence suggests

... been found in the Pacific Northwest, we favor the hypothesis that the minor type represents one of two parental strains that gave rise to the major outbreak isolate," said study author James Fraser, Ph.D., also of Duke. "The second parent strain remains to be discovered." Additional examination of the mating ...

Federal grant funds research on novel HIV therapy

...system," said Dr. Douglas, "and we are testing the hypothesis that interfering with substance P receptors may reduce neurological injury from HIV infection." Project 3, led by Andrew A. Lackner, Ph.D., D.V.M., director of the Tulane National Primate Research Center, will test whether NK-1R antagonists are saf...

Bacteria that cause tooth decay able to survive without important biochemical pathway

... the absence of the SRP pathway. They tested their hypothesis and found that S. mutans could continue to function in non-stress conditions without the SRP and YidC1 genes, but not without the YidC2 and SRP simultaneously. "The fact that the bacteria could survive without the SRP pathway was the most striking f...

Plants, too, have ways to manage freeloaders

...n in separate nodules. "These results support the hypothesis that legumes can favor more cooperative rhizobia b...keep nodules small is by limiting oxygen, but this hypothesis needs further testing, she said. Simms noted that crop plants such as soybeans have been shown to p...

UCLA imaging study of children with autism finds broken mirror neuron system

... emotion centers of the brain, consistent with the hypothesis that this mirroring mechanism may play a crucial role for understanding how others feel and for empathizing with them. All of the children rehearsed the tasks prior to the fMRI scans to assure researchers they could perform the tasks. Both groups pe...

MicroRNA may have fail-safe role in limb development

...n the limbs through microRNA expression. That is a hypothesis that people in the field will have to test, but it is strongly supported by their research." ...

Alleged 40,000-year-old human footprints in Mexico much, much older than thought

...turns out, throws more cold water on the footprint hypothesis came to Renne one morning in the shower. Many rock... Environment Research Council, have promoted their hypothesis widely, most prominently at a July 4, 2005, presentation and press conference at the Royal Society's...

Predators keep the world green, ecologists find

...Despite being almost 50 years old, the green world hypothesis has been almost impossible to test until now. "Si...able." However, the researchers realized that the hypothesis could be tested on a vast hydroelectric project. Within Venezuela's Caroni Valley, an area of 4,300...

Study ties 'new' cell-death mechanism to developmental and degenerative brain disorders

... neurodegeneration field has been dominated by the hypothesis of misfolded proteins and their aggregation, but t...ration do not necessarily supersede the prevailing hypothesis of defective proteins. In fact, the two may be linked. "It could be that the behavior of the nerve ...

New evidence questions the simple link between prion proteins and madcow disease

...A lot of people are completely wedded to the prion hypothesis of diseases like vCJD, but the more you deal with ...one possible explanation that keeps with the prion hypothesis is that infection occurs as PrPs are absorbed in the mouth, rather than in the gut. Dr Jeffrey, how...

Evolutionary biology research techniques predict cancer

...ading to a cancer relapse. He hopes to pursue this hypothesis in the future. "More immediately," he adds, "we intend to validate the new study with other cohorts and other types of tumors." ...

Common bacteria pirate natural mechanism to get inside cells

...structing the cell to do bad things, he says. "The hypothesis is that in cancer, for example, the receptors get stuck on 'on'." Receptor over-stimulation also helps explain why some drugs stop being effective over time. "What that means is there are no more receptors outside the cells to be affected by the dru...

Researchers create pigs that produce heart-healthy omega-3 fatty acids

...ading to a cancer relapse. He hopes to pursue this hypothesis in the future. "More immediately," he adds, "we intend to validate the new study with other cohorts and other types of tumors." ...

UCLA scientists find male gene in brain area targeted by Parkinson's

...ase," he said. "Our lab is currently studying this hypothesis in an animal model." Sex differences in other dopamine-linked disorders, such as schizophrenia or addiction, may also be explained by the SRY gene, Vilain said. "It's possible that dopamine-related disorders that reveal dramatic differences in seve...

There's something fishy about human brain evolution

...e us food security and higher nutrient density. My hypothesis is that to permit the brain to start to increase in size, the fittest early humans were those with the fattest infants," says Dr. Cunnane, author of the book Survival of the Fattest, published in 2005. Unlike the prehistoric savannahs or forests, ar...

How does the brain know what the right hand is doing?

... for how the brain achieves this: (1) the outflow hypothesis says that the brain monitors signals it sends to t...redict where the limb has moved to; (2) the inflow hypothesis suggests that the brain relies on information from sensors within tissues that say how far a limb ha...

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