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Tag: "sex" at biology news

A gene's first 'kiss' sets off that affair known as puberty

...nd FSH cause the testes and ovaries to produce the sex hormones testosterone and estradiol, the culprits responsible for the physical changes and emotional baggage of male and female puberty, respectively. "We now have very good evidence that the GPR54 gene and its switch, the kisspeptin protein molecul...

Topical treatment shown to inhibit HIV and herpes simplex virus infection

...ated by the World Health Organization, unprotected sex is the predominant mode of HIV transmission, and genital herpes plays a major role in the sexual spread of HIV. The researchers conducted a prospective, randomized, double blind, placebo-controlled study among 20 HIV-infected women to assess the ant...

Male circumcision reduces risk of HIV transmission from women to men

...robability ofHIV infection per act of heterosexual sex among a population withmultiple sexual partners has found that uncircumcised men have morethan twice the risk of acquiring HIV than do circumcised men.In the study, published in the Feb. 15 issue of The Journal ofInfectious Diseases, now available on...

Found: Missing sequence of the human Y chromosome

...l sequences were still missing.The Y chromosome, a sex chromosome that is specific to the human male,has posed a particular challenge to researchers attempting to decodeits sequence. It contains an extraordinary abundance of repetitiveelements, including transposons and tandem arrays of satellitesequence...

Female sex hormones play a vital role in defense against sexually transmitted diseases

...be published in the Journal of Virology, show that sex hormones have a profound effect on susceptibility ... reaffirms previous research, that in female mice, sex hormones have a profound effect on susceptibility to sexually transmitted infections as well as on t...

NYC's First Rapid HIV Drug-resistant AIDS Case Prompts Call to Step Up HIV Prevention

...een September 2000 and May 2003 -- had unprotected sex with numerous male partners in mid-October, report...ouraging gay men, in particular, to practice safer sex and use condoms during all sexual encounters." "This case in New York underscores the crucial need ...

How the environment could be damaging men's reproductive health

...e pollutants (POPs) can affect the distribution of sex chromosomes in sperm, leading to a slight increase...e first study to show that the distribution of the sex chromosomes in sperm can be affected by exposure to POPs," said Prof Giwercman. The study did not e...

Variation in women's X chromosomes may explain differences among individuals, between sexes

...at the extensive variation in gene activity in the sex chromosomes means that, in essence, there is not o...osome. In animals, sexual identity is governed by sex chromosomes. In humans and other mammals, males have one X and one Y chromosome, while females have ...

HIV vaccine trial breaks ground for future research

...ntravenous drugs. The volunteers were men who have sex with men or women at high risk for heterosexual transmission. The vaccine and placebo were given by injection seven times over 30 months and the participants were assessed for risk. At each visit the participants were tested for HIV infection, and fo...

HIV-1 spread through six transmission lines in the UK

... least six large transmission chains of men having sex with men, suggesting separate introductions of sub...t increase in high-risk behaviour among men having sex with men, a significant increase in condom use has been reported since 1990, which could explain the...

Love's all in the brain: fMRI study shows strong, lateralized reward, not sex, drive

...spects of human behavior than with the emotions or sex drive. Brain systems were activated that humans sh...nswered the "historic question of whether love and sex are the same, or different, or whether romantic passion is just warmed over sexual arousal." He said...

Same-Sex Mating Discovered in a Toxic Fungus

...plants and animals, sexual identity is governed by sex chromosomes. In fungi, however, sexual identity is...ungi, usually exist in an approximately one-to-one sex ratio," Lin said. "Yet in Cryptococcus neoformans, one mating type predominates, leaving them with a...

Youth With HIV Take More Risks After New Meds Introduced

Teens with HIV are having more risky sex with more partners than their counterparts did in ...rted having more sexual partners, more unprotected sex and more drug use than HIV-positive youth studied between 1994 and 1996, say Marguerita Lightfoot, P...

AIDS Public Awareness Campaign Expands Following Report Of Rapidly Progressive HIV

...s a male in his mid-40s who reported multiple male sex partners and unprotected sex, often while using cr...ansmitted disease (STD); and/or * Have engaged in sex with multiple partners. People who wish to be tested for HIV/AIDS may contact: * New York State HI...

Mother birds increase progesterone to hatch females

In mammals, sperm from the male determines the sex of the offspring. In birds, however, it is the female's sex chromosome that determines offspring sex. Now, Cornell University researchers think they understand ...

Radio-tracking associated with 'dramatic shift' in water vole sex ratio

...oles was associated with a "dramatic shift" in the sex ratio of the animals' offspring, casting doubt on ...ly cause for the female decline was a shift in the sex ratio of young raised by radio-collared females. This result has implications for conservation resea...

New study: Sexually transmitted disease treatment can be effectively administered by sex partners

...t have referral tear-out cards for distribution to sex partners. The new method, known as patient-deliver...gonorrhea infection, and most reported two or more sex partners. The men were each randomly assigned to one of the three partner treatment arms. Nearly 80 ...

Measurement Challenges In Detecting Cancer Biomarkers

...t have referral tear-out cards for distribution to sex partners. The new method, known as patient-deliver...gonorrhea infection, and most reported two or more sex partners. The men were each randomly assigned to one of the three partner treatment arms. Nearly 80 ...

New Finding May Aid Adult Stem Cell Collection

...t have referral tear-out cards for distribution to sex partners. The new method, known as patient-deliver...gonorrhea infection, and most reported two or more sex partners. The men were each randomly assigned to one of the three partner treatment arms. Nearly 80 ...

Certain fish have a special mating preference

... That does not exclude males with an average-sized sex organ, called a gonopodium. These fish out-compete the larger-endowed males in a predator-laden environment because they have a faster burst speed than the males with larger genitalia, who lose out because the size of their organ slows them down, mak...

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