Antigravics

http://www.physorg.com/news139670057.html

>> Marmoset dads that get a whiff of their own babies experience decreased testosterone.
Testosterone is the most abundant, if not the most potent, male hormone in primates, including humans. Produced by the adrenal gland and the testicles, testosterone promotes the maintenance of secondary male characteristics, including such things as muscle mass and strength, fat distribution, bone mass and sex drive. Some studies suggest it may also contribute to male aggressiveness.

Marmosets live in family groups and are prolific breeders. Fathers play a big role in raising their young, joining the female in a care-giving role within a few hours of the birth of offspring, which frequently arrive in pairs. Marmoset babies are also large, each coming into the world at 10 percent of adult weight.

"The female totally needs help. She can't assume all of the parenting responsibilities on her own," says Ziegler, noting that marmoset females also typically become pregnant again within a few weeks of giving birth. "They need a lot of help. That's where the dads come in."

Marmoset males are known to be responsive to female scents, but the new Wisconsin study is the first to show that male physiology can also be influenced by a particular odor from a baby marmoset.

The new study was conducted by isolating experienced male marmoset fathers from their families — and their odors — and presenting them with either a scent from their infants' genital area or a control scent. Similarly, males with no experience as parents were presented with the same odors. Blood tests taken within 20 minutes of exposure revealed a marked decline in testosterone for only those experienced males given the scent of their own babies.

"This shows the male is responsive to chemical cues from their infants," explains Ziegler. ""We saw no behavioral response, but we saw in every single father a significant decline in testosterone."

The finding is interesting and mildly surprising, says Ziegler, because while depressed levels of the hormone may aid the father in his care-giving role, he still must assume important responsibilities such as defending his turf and family, behaviors that may benefit from a jolt of testosterone as opposed to lower levels of the hormone.

"What we are seeing is the system is flexible and that it adjusts up and down," says Ziegler. "It is interesting that the infant can have this parenting effect on the fathers." <<<

http://www.physorg.com/news143122273.html

>> The Testosterone treatment, called LibiGel, is one of the first therapies geared toward women with low libidos, as opposed to men (think Viagra and Cialis). Patients apply the gel once a day to skin on their upper arm, delivering testosterone through the skin and into the bloodstream.

An estimated 40 million women suffer from some type of sexual disorder, according to a study published in the Journal of the American Medical Association. The most common is a lack of sexual desire, which can harm a woman's relationships as well as her physical and mental health.

While a wide range of physical and psychological disorders can lead to loss of libido, a low level of testosterone - a hormone that plays a key role in sex drive in both men and women - often is to blame. Since the ovaries produce the hormone, a woman's interest in sex may drop after she goes through natural menopause or has her ovaries removed, also known as surgical menopause.

Early studies on LibiGel showed it raised blood testosterone levels to normal levels in women who had gone through surgical menopause. Participants reported more satisfying sex lives with no serious side effects.

Doctors have prescribed testosterone pills to women for years, but side effects include acne and excessive hair growth.

If the trial goes well, the treatment could be available by prescription in about three years. >>>

http://www.physorg.com/news154962704.html

>> "safer sex" - is using techniques and products to reduce the risk of infection or pregnancies from intercourse. Products shown to reduce the transmission of infections include condoms or protective barriers such as dental dams and female condoms.

Most of us don't need a medical excuse to have sex, but for those of you who need arm-twisting, here are some important reasons to get playful:

Sex may reduce pain: The chemical oxytocin is released from the brain during orgasm, and this in turn seems to release endorphins into the body. Endorphins are the body's natural painkillers.

Sex may decrease the incidence of prostate cancer: A study published in the British Journal of Urology in 2003 found that men in their 20s could reduce their chances of prostate cancer by ejaculating more than five times a week.

Sex may prevent illnesses such as colds and flus: A 1999 study at Wilkes University in Pennsylvania found that people who have sex one or two times a week had higher levels of immunoglobulin A, the immune cell protein that protects against viral illnesses.

Sex seems to prolong life: A 1997 study from the British Medical Journal followed 1,000 men over 10 years and found that men who had a higher frequency of orgasm had half the death rate of those with fewer orgasms.

Sex burns calories: perhaps 200 calories.

Sex gives muscles a workout: Muscles in the pelvic floor (the ones that help bladder control) are strengthened during sex. Muscles in the back, thighs, glutes, abs and arms can get a workout.

That's great, you may say, but you're older now, and your sex drive has tanked a bit. Remember that intention is the most powerful force at work when you want to bring something into your life. Make it your intention to have a passionate sex life.

Take care of your body and live life as a confident sexual being as you age. Here are more tips for enhancing your sex life:

• Keep healthy. Obesity, diabetes and vascular disease can wreak havoc on sex. Avoid smoking, eat a healthy diet and keep a healthy weight.

• Get exercise. Aerobic exercise enhances blood supply to the genitalia, which enhances orgasm.

• Try using sex toys and lubricants. The hands get more arthritic, the penis gets softer, the vagina gets drier and the female orgasm takes longer. Vibrators and lubricants are a great ways to get around these challenges.

Erectile dysfunction is common after the age of 50. Fortunately, lots of treatments are available, so talk to your doctor. >>>

http://www.physorg.com/news173512654.html

>> The sperm of male fruit flies are coated with a chemical 'sex peptide' which inhibits the female's usual afternoon siesta and compels her into an intense period of foraging activity.

The surprise discovery was made by Professor Elwyn Isaac from the University of Leeds' Faculty of Biological Sciences when investigating the marked differences in sleeping patterns between virgin and mated females.

Both male and female fruit flies (Drosophila melanogaster) - commonly seen hovering around rotting fruit and vegetables - are active at dawn and dusk, and have a deep sleep at night. They also exhibit a marked 'resting state' during the afternoon, which Professor Isaac likens to a siesta that conserves the fly's energy and reduces damaging exposure to the sun during hot afternoons.

"However, we noted that after mating, females still slept deeply at night, but ditched the usual siesta in favour of extra foraging and searching for places to lay her eggs," he says. "This behaviour lasts for around eight days - and our research findings suggest that this change is not by choice. Females who mated with males that produced sperm without the sex peptide continued to take their siesta. So we're certain that this change of behaviour is chemically induced by the male."

"Sleep is an ancient and essential mechanism in living creatures from worms to humans, so to inhibit this for such a long period and replace it with extra activity that exposes the female to environmental hazards and danger from predators must require a powerful mechanism," he says.

The sex peptide is produced in the males' accessory glands (the equivalent of the human prostate gland) and attaches itself to the surface of the sperm's tail. Previous research studies have shown that the sex peptide encourages females to increase egg production - a mated female will lay up to 100 eggs a day compared with 1-2 eggs laid by a virgin female. It also inhibits her from mating with other males for around a week to ten days.

"It would appear that preventing sleep and inducing extra domestic-type duties to prepare for the birth of offspring in females is a further tactic used by the male to ensure successful paternity after mating," says Professor Isaac.

Professor Isaac says that the discovery sheds further light on the role of signalling molecules in the brain. "If we can work out exactly how this natural molecular switch can disrupt sleep behaviour, we may be able to apply this knowledge to neurological disorders relating to human sleep such as narcolepsy, which we think is caused by a fault in the neuropeptide signalling pathway in the brain."

Fruit flies are a good model for looking at sleep behaviour in humans as they exhibit many of the hallmarks of mammalian sleep. For example they sleep deeply at night from which they're difficult to rouse and they have a preferred sleeping posture. If kept awake through the night, they exhibit tiredness the next day; if fed caffeine, they stay awake, and they become drowsy if given antihistamines. The fruit fly's genome has also been fully mapped, so wide ranging genetic studies are possible. >>>>

Comment
Extra sexual activity inhibited for seven days after mating to laying eggs in fruit fly

the seven years itch in human beings......after giving birth

http://www.physorg.com/news181472013.html

>> A study in the Jan. 1 issue of the journal Sleep shows that erectile dysfunction was more common in older men with restless leg syndrome (RLS) than in those without RLS, and the magnitude of this association increased with a higher frequency of RLS symptoms.

Results show that erectile dysfunction was 16 percent more likely in men with RLS symptoms that occur five to 14 times per month (odds ratio of 1.16) and 78 percent more likely in men whose RLS symptoms occur 15 or more times a month (OR=1.78). The associations were independent of age, body mass index, use of antidepressants, anxiety and other possible risk factors for RLS. Fifty-three percent of RLS patients and 40 percent of participants without RLS reported having erectile dysfunction, which was defined as a poor or very poor ability to have and maintain an erection sufficient for intercourse.

The results suggest it is likely that the two disorders share common mechanisms, said lead author Xiang Gao, MD, PhD, instructor at Harvard Medical School, associate epidemiologist at Brigham and Women's Hospital and research scientist at the Harvard School of public health in Boston, Mass.

"The mechanisms underlying the association between RLS and erectile dysfunction could be caused by hypofunctioning of dopamine in the central nervous system, which is associated with both conditions," said Gao.

Data were collected from 23,119 men who participated in the Health Professionals Follow-up study, a large ongoing U.S. cohort of male dentists, optometrists, osteopaths, podiatrists, pharmacists and veterinarians. Participants were between the ages of 56 and 91 years, with a mean age of 69 years. To reduce possible misclassification of RLS, participants with diabetes and arthritis were excluded.

Participants were questioned in 2002 about RLS diagnosis and severity based on the International RLS study group criteria. RLS was defined as having unpleasant leg sensations combined with restlessness and an urge to move; with symptoms appearing only at rest, improving with movement, worsening in the evening or at night compared with the morning, and occurring five or more times per month.

About four percent of participants had RLS (944 of 23,119 men), and about 41 percent (9,433 men) had erectile dysfunction. Men with RLS were older and were more likely to be Caucasian. The prevalence of erectile dysfunction also increased with age.

The authors noted that the association between RLS and erectile dysfunction also could be related in part to other sleep disorders that co-occur with RLS. For example, obstructive sleep apnea and sleep deprivation may decrease circulating testosterone levels.

They also pointed out that the cross-sectional design of the study did not allow for a determination of causality. Further epidemiological studies are needed to clarify the relationship between the RLS and erectile dysfunction and to explore the biological mechanisms underlying the association. >>>

http://www.physorg.com/news181826700.html

>> Women's minds and genitals respond differently to sexual arousal, whereas in men, the responses of the body and mind are more in tune with each other, according to Assistant Professor Meredith Chivers, from Queen's University in Kingston, Canada, and her international collaborators, Michael Seto, Martin Lalumičre, Ellen Laan, and Teresa Grimbos. Their meta-analysis of the extent of agreement between subjective ratings and physiological measures of sexual arousal in men and women is published online this week in Springer's journal Archives of Sexual Behavior.

The human sexual response is a dynamic combination of cognitive, emotional and physiological processes. Chivers and colleagues were interested in the degree to which an individual's experience of sexual arousal mirrors physiological genital activity and whether gender difference in this agreement (commonly reported in individual studies) would be found when a meta-analysis of sexual psychophysiology studies was conducted.

The authors reviewed 134 studies, published between 1969 and 2007, which measured the degree of agreement between subjective experiences of sexual arousal and physiological genital responses. Overall, the studies reviewed data collected from over 2,500 women and 1,900 men. Participants indicated how aroused they felt during or after they were exposed to a variety of sexual stimuli, called subjective arousal. Researchers measured the physiological responses to the sexual stimuli using different methods, including changes in penile erection for men and changes in genital blood flow for women.

Men's subjective and physiological measures of sexual arousal showed a greater degree of agreement than women's. For the male participants, the subjective ratings more closely matched the physiological readings indicating that men's minds and genitals were in agreement. For the women, however, the responses of the mind and genitals were not as closely matched as men's, suggesting a split between women's bodies and minds. The readings from the physiological measurements and their subjective ratings were, in some cases, significantly different.

The researchers then looked at factors in the studies that might shed some light on this gender difference. They identified two methodological differences, in particular, that may play a role.

The type of sexual stimuli - their content and how it was presented e.g. visually or as an audio recording - made no difference to how well the subjective and physiological responses mirrored each other in men. However, it did influence women's responses. Women exposed to a greater range and number of sexual stimuli - content and presentation - were more likely to have stronger agreement between subjective and physiological responses.

The timing of the assessment of self-reported sexual arousal also had an effect. When participants were asked to rate their subjective arousal at the end of each stimulus, men's responses were closer to one another than women's. However, when both men and women were asked to rate their arousal whilst they were exposed to the stimulus, the gender difference disappeared because men's concordance dropped to the range of women's.

The authors conclude: "The assessment of sexual arousal in men and women informs theoretical studies of human sexuality and provides a method to assess and evaluate the treatment of sexual dysfunctions. Understanding measures of arousal is, therefore, paramount to further theoretical and practical advances in the study of human sexuality. Our results have implications for the assessment of sexual arousal, the nature of gender differences in sexual arousal, and models of sexual response." >>>

http://www.physorg.com/news184570915.html

>> An Australian National University team conducting a 20-year population study on health and ageing analysed the mental function of a group of women before and during pregnancy and in the early stages of motherhood.

"We didn't find any difference between the women before and after pregnancy, or before and after motherhood, and there were no differences between the non-mothers and the mothers, and the pregnant women," lead researcher Helen Christensen told AFP.

The women were given memory and cognitive speed tests three times over eight years as part of the "Path Through Life" study, which is tracking the mental health of a random sample of 7,500 Australians over 20 years.

Christensen said the findings were unique because the women were not told they were being tested for a pregnancy study when they signed up and it was the first time researchers could make a comparison with pre-conception scores.

"You don't have necessarily the biases that you might have if you are just doing a study where you recruit women to a pregnancy study," she said.

"When they're doing the cognitive test they don't know that it's out to prove that they've lost their marbles or otherwise."

According to the study, which was published in the British Journal of Psychiatry, pregnant women were frequently warned about the possibility of short-term memory problems, a condition guidebooks described as "baby brain" or "placenta brain".

"These views are supported by scientific research evidence and systematic reviews," it said.

While the study had found some limited impact on cognitive speed in late pregnancy, Christensen said the results showed that carrying a baby had "pretty much no permanent effects" on a woman's mental function.

"I think that people have the tendency to blame the fact that they're pregnant on normal lapses of memory which happen all the time to us anyway," she said.

Christensen said the findings showed "'placenta brain' is not inevitable, and that perceptions of impairment may reflect emotional or other unknown factors."

"Our results challenge the view that mothers are anything other than the intellectual peers of their contemporaries," she said. >>>

http://www.abc.net.au/news/stories/2010 ... 831886.htm

>> A report commissioned by the British government has found that adult sexuality is being imposed on children and teenagers through a tide of images in the media.

The study has found such images put pressure on young people to aspire to an unhealthy ideal.

It called for men's magazines to carry an age warning and music videos with sexual posing should not be shown until late in the evening to help combat the sexualisation of children.

The report also said video games consoles and mobile phones should be sold with parental controls already switched on, and that an online "one-stop-shop" should be set up for the public to voice concerns about irresponsible marketing.

Psychologist Dr Linda Papadopoulos, the report's author, said children and young people were exposed to growing amounts of "hyper-sexualised images", and were also sold the idea they had to look "hot" and "sexy".

"As such, they are facing pressures that children in the past simply did not have to face," the report said.

"While sexualised images have featured in advertising and communications since mass media first emerged, what we are seeing now is an unprecedented rise in both the volume and the extent to which these images are impinging on everyday life."

This impacted on young people's "mental and physical health, attitudes and beliefs" and led some children to suffering poor self-esteem and eating disorders, it said.

The report, which forms part of the government's strategy to tackle violence against women, comes a week after the opposition Conservatives said they would take action against companies guilty of sexualising children.

Conservative leader David Cameron said his party would bring in measures to tackle irresponsible marketing practices aimed at children and companies that breached advertising guidelines.

The theme is likely to become a major issue for the major parties in Britain's upcoming general election.

"We know that parents are concerned about the pressure their children are under at a much younger age, which is why we have already committed to a number of the recommendations in this report," Home Secretary Alan Johnson said.

The study highlighted magazines as an issue, with the trend of dressing children provocatively and the sexualised ideals of young, thin beauty.

"A dominant theme in magazines seems to be the need for girls to present themselves as sexually desirable in order to attract male attention," it said.

Publications aimed at young men, so-called lads' mags which feature pictures of scantily clad women, were also a problem.

"Lads' mags contain a high degree of highly sexualised images of women that blur the lines between pornography and mainstream media," the report said.

"The predominant message for boys is to be sexually dominant and to objectify the female body."

The report's 36 recommendations included:

# A ratings system for photographs to show the extent to which they have been digitally altered.

# Music videos with sexual posing or sexually aggressive lyrics to be broadcast only after the 9.00 pm.

# Men's magazines should be marked as recommended for sale to only those aged 15 and over, and placed away from children's view in the same way as pornographic magazines.

# A government ban on adverts for jobs in the adult entertainment industry to be placed in job centres.>>>

http://www.huffingtonpost.com/2010/02/1 ... &&&&&&&&&&

>> The antechinus, a mouse-like marsupial, is polygamous. Each antechinus female will mate with several males in a breeding season, with the result that a single antechinus litter has several fathers. The antechinus mating ritual is long and exhausting with copulation lasting up to twelve hours. In fact, following the breeding season, there is complete die-off of the physiologically exhausted males of the group.>>

Sexual cannibalism has been documented only in arachnids, insects and amphipods although anecdotal evidence suggests its existence in gastropods and copepods as well

Black widow spider Latrodectus mactans, Praying Mantis... cannibalistic

>> 48 healthy males participated in the experiment. Half received an oxytocin nose spray at the start of the experiment, the other half a placebo.

The oxytocin group responded clearly better to the feedback in the form of facial expression than did the placebo group".

In this connection, the so-called amygdaloid nucleus appears to play an important role. This cerebral structure, known generally to doctors as the amygdala, is involved in the emotional evaluation of situations. Certain people suffer from an extremely rare hereditary disease which progressively affects the amygdala. "We were lucky to be able to include two females patients in our study group who were suffering this defect of the amygdala", says Hurlemann. "Both women reacted markedly worse to approving or disapproving faces in the observation test than did other women in a control group. Moreover, their emotional empathy was also affected". Hence, the researchers suspect that the amygdala could bear some form of co-responsibility for the effect of the oxytocin.

One of the effects of the hormone oxytocin is that it triggers labour pains. It also strengthens the emotional bond between a mother and her new-born child. Oxytocin is released on a large scale during an orgasm, too. This neuropeptide is also associated with feelings such as love and trust. Our study has revealed for the first time that emotional empathy is modulated by oxytocin, and that this applies similarly to learning processes with social multipliers, says Hurlemann. This hormone might thus be useful as medication for diseases such as schizophrenia, which are frequently associated with reduced social approachability and social withdrawal.

http://www.physorg.com/news191761448.html

>> A new Dutch study has found pregnant women who drink lots of coffee every day may have smaller babies.

Researchers in Rotterdam studied women who consumed the caffeine equivalent of six cups of coffee per day during their pregnancy.

They say, on average, their babies were slightly shorter than newborns whose mothers had consumed less caffeine during pregnancy.

The findings have been reported in the American Journal of Clinical Nutrition and add to the conflicting body of research on whether caffeine affects foetal growth.

"Caffeine intake seems to affect length growth of the foetus from the first trimester onwards," researcher Rachel Bakker said.

Heavy caffeine consumers also had an increased risk of having a baby who was small for gestational age - smaller than the norm for the baby's sex and the week of pregnancy during which he or she was born.

That finding, however, was based on a small number of babies, and the significance is uncertain.

Of 104 infants born to women with the highest caffeine intakes, seven were small for gestational age.

In this study, Ms Bakker and colleagues at the Erasmus Medical Centre used ultrasound scans to monitor foetal growth over the course of pregnancy in 7,346 women.

At each trimester, the women reported on their usual intake of coffee and tea.

Most women consumed less than the equivalent of four cups of coffee per day at any point in pregnancy, but between 2 and 3 per cent downed six or more cups' worth of caffeine.

http://www.abc.net.au/news/stories/2010 ... ion=justin

>>> New research suggests women become less trusting, less open, more vigilant, and more skeptical and cynical if they are given the male hormone testosterone. This may reflect the survival value for women of being sociable and co-operative, whereas males have historically needed to fight competitors for resources if they were to survive.

The hormone testosterone makes men stronger, larger, and more aggressive, and the new research suggests it also makes them less open and more distrustful, “watching their backs” for dangers. While testosterone is often called the male sex hormone, it is also present in women, but in smaller amounts.

Psychologist Dr Jack van Honk gave either a placebo or the hormone testosterone to a group of 24 women with an average age of 20, and then switched pills, so all the women were given both the testosterone and the placebo. The women were asked to rate 150 photographs of strangers’ faces for trustworthiness, using a scale of +100 (most trustworthy) to -100 (least trustworthy) when they were taking the placebo, and when they were given the hormone.

The research found that women who were most trusting on the placebo rated faces as around 5 percent less trustworthy while taking the hormone pills. Women who were least trusting on the placebo did not appear to be affected, and van Honk speculated this might be because in less trusting individuals the hormone could make them paranoid and socially disabled.

The results also showed the natural level of testosterone in the women had no effect, and their mood also had no effect. The researchers said there was no evidence the women knew when they were taking testosterone.

The authors of the paper, published in the journal Proceedings of the National Academy of Sciences, say the research shows how testosterone regulates human sociability because it “down-regulates interpersonal trust in an adaptive manner.”

Dr van Honk said you have to be “socially sharp” to be successful in competition, and it is not socially sharp to trust people you do not know. He also said testosterone may increase the production of the hormone vasopressin, which has been shown to increase territorial behavior and aggression in animals, although he said social dominance in humans is not about aggression. It could also oppose the hormone oxytocin, which has been implicated in trust and social bonding.

Dr van Honk said being wary of strangers or competitors is an important part of “rising through the ranks” in humans, and being less trusting could also give economic benefits. He said he could also see applications of testosterone in treating psychiatric disorders such as social anxiety disorder.

http://www.physorg.com/news193983556.html