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Tag: "reproductive" at biology news

Temperament linked to onset of cancer and early death in female rats

...prehensive rats were more likely to have irregular reproductive cycles than adventuresome rats, and that disruption could account for hormonal differences linked to the development of cancer earlier, the scholars found. There was no difference in the length of time between onset of cancer and death in the two se...

Climate change has surprising effect on endangered naked carp

...te. Naked carp take seven to ten years to reach reproductive size. Although historically abundant, overfishing and destruction of spawning habitat through dam-building caused the species to become endangered during the 1990s. Diversion of water for agriculture from the lake has been compounded by climate chang...

'Nymph of the sea' reveals remarkable brood

... and indicates a remarkably conserved egg brooding reproductive strategy."...

More kidney cancer is detected and treated early, yet death rate rises

...common malignancy of the genitourinary system (the reproductive system and urinary system). The American Cancer Society estimates there will be about 38,890 new cases of kidney cancer (24,650 in men and 14,240 in women) in the United States this year, and about 12,840 people (8,130 men and 4,710 women) will die f...

A new male-specific gene in algae unveils an origin of male and female

...y, a more simple form of sex in which very similar reproductive cells take on different "mating types" but do not differentiate as distinct sperm and egg. The transition from isogamy to oogamy has apparently occurred multiple times during the evolution of animals, plants, and some algae, but how did such transiti...

Dragonfly's metabolic disease provides clues about human obesity

... muscles work and affect the animal's survival and reproductive capabilities, can mechanically isolate single flight muscles and measure their mechanical power output under conditions similar to those in nature. The researchers noted that the muscles of some dragonflies are able to perform at 80 watts per kg. wh...

Male chimpanzees prefer mating with old females

... young females more valuable as mates with greater reproductive potential. The findings, reported by Martin Muller of Boston University and colleagues at Harvard University, appear in the November 21st issue of Current Biology. Theoretical explanations for the preference of human males for young females as mat...

Single molecular 'mark' seen as pivotal for genome compaction in spores and sperm

...e passed to the next generation in spores. In both reproductive strategies, major physical changes occur in the genetic material after it has been duplicated and then halved on the way to the production of mature gametes or spores. Near the end of the process, the material ?called chromatin, the substructure of c...

Exposure to dioxins influences male reproductive system, study of Vietnam veterans concludes

...ntained in the herbicide Agent Orange affects male reproductive health by limiting the growth of the prostate glan...n Agent Orange, may disturb the male endocrine and reproductive systems in several ways. "Until now, we did not have very good evidence whether or not dioxins af...

For crickets, parasitic flies can stop the music

...hand, singing and finding mates increases a male’s reproductive success; on the other, it also carries high potential costs, Brockmann said. "The interesting question is how exactly do these conflicting pressures play out in evolution"" Scientists have known for some time that parasitic flies, known scientifi...

Wild tigers need cat food

...numbers remain stable due to a combination of high reproductive rates and abundant prey. The study, which appears...nual losses, and yet do fine because of their high reproductive rates," said WCS researcher Dr. Ullas Karanth, lead author of the study. "The conservation implicat...

Researchers discover that sheep need retroviruses for reproduction

...lity to cause diseases, said Dr. Thomas Spencer, a reproductive biologist with the Texas Agricultural Experiment Station and Texas A&M University. Findings published Sept. 11 in the Proceedings of the National Academy of Sciences demonstrate enJSRVs are essential for the development of the placenta in shee...

Hormone linked to brain's cravings for food and other energy sources

...ine, neurobiology and obstetrics, gynecology & reproductive sciences. In this study, Horvath and colleagues found that ghrelin could signal directly in the VTA region and activate dopamine neuronal activity, which controls reward-associated behavior to promote interest in food as a reward. As a default, gh...

Some butterflies travel farther, reproduce faster

...ratory The study, "Population history-dependent reproductive physiology in a butterfly metapopulation," will be...For those reasons, natural selection on flight and reproductive capability acts primarily on the females. Travelers reproduce more quickly This study examined...

Why do insects like to eat some plants more than others?

...uction and future survival. The finding that plant reproductive allocation can attract enemies means that sex may be even more costly than previously though. This research also has implications for weed control and protection of rare plant species. ...

Virus may control Australia's

...is generally viewed as a major pest. "Given their reproductive capacity and their hardiness, carp have been termed the 'rabbit of the river'."Carp were introduced into Australia in the early 1900s as a food and sporting fish. During extensive flooding in the 1970s the fish escaped from farm dams and took over th...

Heavy smoking cuts women's chance of pregnancy -- even with donated oocytes

... on line (Thursday 9 November) in Europe's leading reproductive medicine journal Human Reproduction. The finding, from a team of fertility experts in Portugal and Spain, comes as a result of comparing the pregnancy rates between non-heavy smokers and heavy smokers, all of whom received donated oocytes. Smoki...

Common ancestry of bacterium and plants could be key to an effective new treatment for chlamydia

...treated, Chlamydia infections can damage a woman's reproductive organs and lead to infertility. An estimated 2.8 million men and women in the U.S. are infected with chlamydia each year. Chlamydia can be easily treated and cured with antibiotics. However, bacteria often develop resistance to antibiotics, meaning t...

Designer babies - what would you do for a 'healthy' baby?

...sented with information and speculation about what reproductive technologies might achieve in the future and with various ethical dilemmas. This new research is among the first to investigate the thoughts and feelings of ordinary prospective parents. The results of a series of surveys of 100-200 participants i...

Why do some queen bees eat their worker bee's eggs?

...reduced rearing of workers' sons or greater worker reproductive policing. Were the textbooks wrong" A new study appearing in the current issue of The American Naturalist strongly supports Hamilton's original theory. Tom Wenseleers and Francis Ratnieks (University of Sheffield) compared 90 species and found tha...

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