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 the mechanism that several bird species use to bias the sex ratios of their offspring toward female. By experimenting with domestic chickens, they have determined that the presence...Male elephants woo females with precise chemistry
The exact chemical blend of a pheromone emitted by older male elephants in musth influences both a female elephant's interest in mating and how other surrounding elephants behave, a new study has found. The researchers at Oregon Health & Science University and the University of Auckland in New Zealand say the release of a specific proportion of two mirror images of the pheromone, fron...New study explores beetle species with two forms of females
A fascinating new study from the forthcoming issue of The American Naturalist attempts to explain the mysterious persistence of two forms of females in many diving beetle populations. Their findings have important implications for theories of sexual conflict, which arises when the costs and benefits of multiple matings differ for males and females. "The male versus female arms race (invo...Male rivalry increases when females at most fertile, say researchers
Men become more jealous of dominant males when their female partner is near ovulation, researchers at the University of Liverpool have found. Previous studies have found that women's preferences for male physical appearance vary according to their fertility status. During ovulation women tend to find masculine looking men more attractive and prefer their voices and odour. During this fer...Brain differences could explain why males and females experience pain relief differently
A study conducted by investigators at Georgia State University and the Atlanta-based Center for Behavioral Neuroscience (CBN) reports that anatomical and functional differences in the brain may explain sex differences in the experience of pain and in the effects of certain drugs on pain. The finding, reported in the April 13 issue of the Journal of Comparative Neurology, is the first rep...Sensitive cough suffered by females
According to this new study it shows that women are more sensitive to stimuli that produce a cough.Researchers in the US investigated a group of 60 women and 30 men attending an outpatient clinic for chronic cough.// They had them inhale substances that cause a cough through a mouthpiece for one second. Then they counted the number of coughs produced by the participants over the next ten...10 Million Indian Females Aborted In 20 years
Around 10 million female fetuses may have been aborted in India in the last couple of decades, according to a study published online today by The Lancet. // Fewer girls than boys are born in India. In their study Prabhat Jha (St. Michael's Hospital, University of Toronto, Canada), Rajesh Kumar (Post-Graduate Institute of Medical Education and Research, Chandigarh, India) and colleagues c...Caffeine: Stimulates Sexual Behaviour in Females
A research conducted by Fay Guarraci, an assistance professor of psychology at south-western university and a graduate student revealed that moderate doses // of caffeine has a greater effect on the sexual behaviour of female rats. This study is one of the kinds and is among the first to determine the effects of caffeine on the sexual stimulation of the female rats. It also probes int...Same Genes Act Differently in Males and Females
UCLA researchers report that thousands of genes behave differently in the same organs of males and females – something never detected to this degree.// The study sheds light on why the same disease often strikes males and females differently, and why the genders may respond differently to the same drug. "We previously had no good understanding of why the sexes vary in their relationsh...Male Chimpanzees find Older Females Sexy
When it comes to mating, male chimpanzees have the opposite taste when compared to the males of one of their nearest biological species, human beings, //according to a study published Tuesday. Unlike human males who prefer younger mates, male chimpanzees like older females and turn up their nose at younger ones. The observation was reported in the journal, Current Biology, based on stu...Testosterone, Females or Children
Description:ARUP Laboratories is a national reference laboratory and a worldwide leader in innovative laboratory research and development. ARUP offers an extensive test menu of highly complex and unique medical tests in clinical and anatomic pathology. Owned by the University of Utah, ARUP Laboratories' clients include more than half of the nation's university teaching hospitals and children's hospitals, maj...Testosterone, Free & Total (Includes Sex Hormone Binding Globulin), Females or Children
Description:ARUP Laboratories is a national reference laboratory and a worldwide leader in innovative laboratory research and development. ARUP offers an extensive test menu of highly complex and unique medical tests in clinical and anatomic pathology. Owned by the University of Utah, ARUP Laboratories' clients include more than half of the nation's university teaching hospitals and children's hospitals, maj...Testosterone Free, Females or Children
Description:ARUP Laboratories is a national reference laboratory and a worldwide leader in innovative laboratory research and development. ARUP offers an extensive test menu of highly complex and unique medical tests in clinical and anatomic pathology. Owned by the University of Utah, ARUP Laboratories' clients include more than half of the nation's university teaching hospitals and children's hospitals, maj...