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Tag: "male" at biology news

Tulane researcher reports on origin of deadly fever outbreak

...tality rate of 83 percent for that outbreak. Young male miners comprised 52 percent of the cases, suggesting that exposure in underground mines was a factor in the spread of the disease. The discovery of multiple different genetic variants of the virus indicates that the two-year outbreak was fueled by r...

Geneticists discover genes that make fruit fly hybrids sterile

...h each other, thereby preventing the production of male offspring. The finding may eventually shed light...n in a D. melanogaster gene called "Hmr" (Hybrid male rescue) and a similar mutation in a D. simulans gene called "Lhr" (Lethal hybrid rescue) that make...

Bad blood between boys and girls

...d Toxoplasma negative women. The probability of a male birth also increased, up to two boys in three chil...ding to the researchers, the increased survival of male embryos in infected women may be explained by toxoplasmosis' modulating and suppressing effects on t...

Mapping the mouse genome

...es. In fact, when calculating rates separately for male and female HS mice, they confirmed results seen previously for humans, that the average autosomal (non-sex) chromosomes had a higher recombination rate for females than males. Observing where there was a particularly high, or low, rate of recombin...

Genetic surprise confirms neglected 70-year-old evolutionary hypothesis

... you mate the two, every now and then you'll get a male with a combination that includes no gene at all. These guys are sterile because they completely lack a gene that's necessary for fertility." The gene, called JYAlpha, is one of the same genes that is essential for sperm motility in the flies, as wel...

Firefighters face increased risk for certain cancers

...10,000 firefighters, most of them full-time, white male workers, from 32 previously published scientific studies to determine the comprehensive health effects and correlating cancer risks of their profession. Risk for 20 different cancers was classified into three categories--probable, possible or not...

PET imaging shows young smokers quick benefit of quitting

...on on coronary endothelial dysfunction in 15 young male adults (in their twenties and thirties) with no other heart diseases or cardiovascular risk factors (other than smoking). The young smokers, who smoked an average of 20 cigarettes a day, agreed to stop for at least six months. Myocardial (heart) bloo...

Road-crossing in chimpanzees: A risky business

...Cell Press. Prior research has shown that adult male monkeys reduce the risks of predatory attacks through adaptive spatial patterning, moving toward the front of the group when traveling toward potentially unsafe areas, such as waterholes, and bringing up the rear when retreating, but comparable data ...

Hair-growth drug artificially lowers PSA levels in prostate cancer screening, study finds

...BPH and male-pattern hair loss have to do with the male hormone testosterone, which is being converted to dihydrotestosterone (DHT) by an enzyme named 5-alpha reductase. DHT activates the genes responsible for the development of male-pattern hair loss. Finasteride interferes with this process by blocking ...

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

...alf sisters. Instead the workers favor the queen's male progeny, since she has mated with multiple males, ensuring variation in the species. According to this theory, a species where the mother queen mates with multiple males would have more worker policing. This theory is widespread and in animal behavio...

Vanishing beetle horns have surprise function

... borne of differential growth; flamboyantly horned male beetles grow them, hornless females simply can't. But the American Naturalist report shows that even within sexually dimorphic horned beetle species, both sexes initially form the horns, even if one or both sexes reabsorb the horn tissue sometime bef...

Male contraception: One door opens, another closes

We have often heard that a new male contraceptive is "five to ten years" away. But are...zed that it was acting as a contraceptive in their male mice at a tenth of the disease-treatment dose. With safety testing already out of the way, they thou...

With fruit fly sex, researchers find mind-body connection

...shaking come-ons and flirtatious flights that mark male and female fly courtship. Results are published...ivity by repressing female behavior and activating male behavior. Other scientists have found that a web of interacting genes control courtship and receptiv...

Huddling and a drop in metabolism allow penguins to survive the South Pole cold

...loggers. The researchers sought to assess whether male emperor penguins lower their deep body temperature during breeding and incubation. Additionally, using external devices during pairing and visual observations of implanted males during incubation, they sought to study deep body temperature variations...

Monitoring poisons in the environment -- a woolly matter

... both lead and copper were significantly higher in male sheep, which has been linked to the effect of androgens on metabolism. Dr Sneddon comments, "Sheep wool evidently has potential as a bio-indicator of naturally occurring heavy metal concentrations in upland areas, which have previously not been as...

Fruit fly gene research may shed light on human disease processes

...dents have been researching how fly embryos become male or female, a process that occurs over a 30-minute ...ascade of proteins to ensure embryos remain either male or female once their sex has been determined, as well as help in the chromosome-counting process and...

The influence of the menstrual cycle on the female brain

...tivation, the same experiment was carried out on a male group. Result: when men anticipate rewards, they mainly activate a region involved in motivation for obtaining rewards, the ventral striatum, whereas in women, it is a region dealing with emotions, the amygdalo-hippocampal region, which is the most h...

Fish can determine their social rank by observation alone, study finds

A male fish can size up potential rivals, and even rank t...orial fish from Africa. "In their natural habitat, male cichlids are constantly trying to ascend socially by beating each other up," said study co-author Ru...

Circumcision: A proven strategy to prevent HIV

...ths, and several million dollars could be saved if male circumcision became routine in sub-Saharan Africa....onal Institutes of Health halted Bailey's trial of male circumcision after the study's independent data safety monitoring board reviewed the preliminary res...

Salamanders suffer delayed effects of common herbicide

... as 0.1 parts per billion have been shown to cause male frogs to develop both male and female organs by altering their production of sex hormones. Findings from Rohr's study, which...

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