cycle

Second messenger NAADP shows fast, dose-related impact on satiety cycle

One traditional approach to pharmaceutical design uses so-called "first messengers" ?hormones, other natural facilitators or synthetic products ?to initiate various cellular cascades for the desired physiological effect. To date, despite concerted efforts at all levels of research, this approach has failed to develop a truly successful obesity drug to address this major global health problem....

FSU biologists describe key role of signal-transcribing gene during cell cycle

Study in Oct. 1 'Development' shows when, where Alzheimer's, some cancers and genetic ills beginT. Biologists at Florida State University have uncovered the pivotal role of a gene called "Cut" that acts as a sort of middleman in cell-to-cell communication. A DNA-binding protein, Cut interprets and transcribes the developmental signals sent through the "Notch" gene, which regulates a layer...

A novel method to measure circadian cycles

Everyone knows morning people and late-night owls. The variation in individual circadian rhythms is an anecdotal as well as experimentally verified fact. But, until now, to systematically study circadian differences (and thereby hope to rout out the underlying genetic causes), scientists have had to rely on prolonged behavioural observation. To screen for and identify circadian rhythm variation...

Microbe has huge role in ocean life, carbon cycle

Researchers at Oregon State University and Diversa Corporation have discovered that the smallest free-living cell known also has the smallest genome, or genetic structure, of any independent cell - and yet it dominates life in the oceans, thrives where most other cells would die, and plays a huge role in the cycling of carbon on Earth. In nature, apparently, bigger is not always better.</...

Marine bacterium suspected to play role in global carbon and nitrogen cycles

Scientists successfully grow 'dwarf belonging to the sea' in laboratoryScientists are now revisiting, and perhaps revising, their thinking about how Archaea, an ancient kingdom of single-celled microorganisms, are involved in maintaining the global balance of nitrogen and carbon. Researchers have discovered the first Archaea known to oxidize ammonia for energy and metabolize carbon dioxide by su...

Hidden sponges determine coral reef's nutrient cycle

Marine organisms hidden in caves, such as sponges, play an extremely important role in the nutrient cycle of coral reefs. Indeed they probably play the most important role of all, says Dutch biologist Sander Scheffers. And that is valuable information for nature conservationists who want to preserve the coral reefs. In order to protect coral reefs it is important to understand how both the...

Web model of influenza-host lifecycles will aid scientists in creating anti-viral drugs

A "starry sky" map linking the myriad interactions between the influenza virus and its human host will help guide researchers in creating new anti-viral drugs, say researchers at UT Southwestern Medical Center. The on-line map, part of a project called Reactome, is intended to teach scientists about parts of the influenza lifecycle they might not be familiar with, and to help researchers...

Of mice, men, trees and the global carbon cycle

A team led by a University of Minnesota researcher has found a universal rule that regulates the metabolism of plants of all kinds and sizes and that may also offer a key to calculating their carbon dioxide emissions, a number that must be known precisely in order to construct valid models of global carbon dioxide cycling. Emissions of the gas occur in both plants and animals through the...

Carbon cycle was already disrupted millions of years ago

Dutch researcher Yvonne van Breugel analysed rocks from seabeds millions of years old. Carbon occurs naturally in two stable forms; atomic mass 12 (99 percent) and atomic mass 13 (1 percent). Episodes in the Jurassic and Cretaceous periods were characterised by a relatively strong increase in 12C. The analyses have shown that this was caused by a sudden large-scale release of carbon from stocks s...

Cycles of cell death, proliferation key to liver cancer

Research at the University of California, San Diego (UCSD) School of Medicine shows that liver cancer is likely caused by cycles of liver cell death and renewal. The research, appearing online the week of June 19 in advance of publication in the journal Proceedings of the National Academy of Sciences, underscores the importance of JNK1-mediated cell death and compensatory proliferation. T...

The vicious cycle of rainforest destruction

Rainforests and savannas contain 70% of the world's plants and are critical to the health of our planet. A new £1.6m international project involving researchers from the Leeds Earth and Biosphere Institute is looking at the impact of global warming on these sensitive areas. The researchers think we may be at the start of a vicious cycle, where global warming causes the rainforests to shrin...

New method confirms importance of fungi in Arctic nitrogen cycle

A new method to calculate the transfer of nitrogen from Arctic mushrooms to plants is shedding light on how fungi living symbiotically on plant roots transfer vital nutrients to their hosts. The analytical technique, developed by John E. Hobbie, MBL Distinguished Scientist and co-director of the laboratory's Ecosystems Center and his son, Erik A. Hobbie of the University of New Hampshire, may be...

Recycled paper and compost could both be key tools to control plant disease

New research by the University of Warwick should have gardeners and commercial growers competing for both recycled paper and organic waste composts. The University's plant research department, Warwick HRI, is finding that recycled paper based composts are proving to be a major weapon in the fight against a range of plant diseases. A University of Warwick research team under Professor Ralp...

MIT's ocean model precisely mimics microbes' life cycles

Scientists at MIT have created an ocean model so realistic that the virtual forests of diverse microscopic plants they "sowed" have grown in population patterns that precisely mimic their real-world counterparts. This model of the ocean is the first to reflect the vast diversity of the invisible forests living in our oceans-tiny, single-celled green plants that dominate the ocean and produ...

The influence of the menstrual cycle on the female brain

What influence does the variation in estrogen level have on the activation of the female brain? Using functional Magnetic Resonance Imaging, Jean-Claude Dreher, a researcher at the Cognitive Neuroscience Center (CNRS/Université Lyon 1), in collaboration with an American team from the National Institute of Mental Health (Bethesda, Maryland) directed by Karen Berman, has identified, for the first t...

Climate change could trigger 'boom and bust' population cycles leading to extinction

Climate change could trigger "boom and bust" population cycles that make animal species more vulnerable to extinction. , according to Christopher C. Wilmers, an assistant professor of environmental studies at the University of California, Santa Cruz. Favorable environmental conditions that produce abundant supplies of food and stimulate population booms appear to set the stage for populati...

Brain's reward circuit activity ebbs and flows with a woman's hormonal cycle

Fluctuations in sex hormone levels during women's menstrual cycles affect the responsiveness of their brains' reward circuitry, an imaging study at the National Institute of Mental Health (NIMH), a component of the National Institutes of Health (NIH), has revealed. While women were winning rewards, their circuitry was more active if they were in a menstrual phase preceding ovulation and dominated...