"OLD FAIRY TALE WITH CONCRETE STUDIES"

"TILL NOW THIS HAS BEEN A FAIRY TALE .NOW THIS IS A REALITY WITH CONCRETE EVIDENCE"

WHY WOULD ANYONE ON THIS EARTH WOULD DATE A WOMEN WHO IS NOT HOT?UNLESS IF HE IS NUTS!

Science is confirming what most women know: When given the choice for a mate, men go for good looks.

In the dating game, men know what they want.

And guys won't be surprised to learn that women are much choosier about partners than they are.

"Just because people say they're looking for a particular set of characteristics in a mate, someone like themselves, doesn't mean that is what they'll end up choosing," Peter M. Todd, of the cognitive science program at Indiana University, Bloomington, said in a telephone interview.

Researchers led by Todd report in Tuesday's edition of Proceedings of the National Academy of Sciences that their study found humans were similar to most other mammals, "following Darwin's principle of choosy females and competitive males, even if humans say something different."

Their study involved 26 men and 20 women in Munich, Germany.

Participants ranged in age from 26 to their early 40s and took part in "speed dating," short meetings of three to seven minutes in which people chat, then move on to meet another dater. Afterward, participants check off the people they'd like to meet again, and dates can be arranged between pairs who select one another.

Speed dating let researchers look at a lot of mate choices in a short time, Todd said.

In the study, participants were asked before the session to fill out a questionnaire about what they were looking for in a mate, listing such categories as wealth and status, family commitment, physical appearance, healthiness and attractiveness.

After the session, the researchers compared what the participants said they were looking for with the people they actually chose to ask for another date.

Men's choices did not reflect their stated preferences, the researchers concluded. Instead, men appeared to base their decisions mostly on the women's physical attractiveness.

The men also appeared to be much less choosy. Men tended to select nearly every woman above a certain minimum attractiveness threshold, Todd said.

Women's actual choices, like men's, did not reflect their stated preferences, but they made more discriminating choices, the researchers found.

The scientists said women were aware of the importance of their own attractiveness to men, and adjusted their expectations to select the more desirable guys.

"Women made offers to men who had overall qualities that were on a par with the women's self-rated attractiveness. They didn't greatly overshoot their attractiveness," Todd said, "because part of the goal for women is to choose men who would stay with them"

But, he added, "they didn't go lower. They knew what they could get and aimed for that level."

So, it turns out, the women's attractiveness influenced the choices of the men and the women.

SOURCE:WASHINGTON(AP)

"LIGHT STIMULATES GROWTH IN INFECTIOUS BACTERIA"

Photosensing proteins are utilized by all forms of living organisms from plants and bacteria to butterflies and humans. These proteins absorb blue light and change shape and trigger other events within a cell. They are also involved in phototropism, the movement of aquatic bacteria, and the regulation of mammalian circadian rhythms. Latest studies found out that they can also drive the spread of infectious disease.

A group of researchers including Howard Hughes Medical Institute international research scholar Fernando A. Goldbaum has discovered that photosensing proteins drive the spread of cattle brucellosis, a bacterial infection that costs cattle farms in Brazil and Argentina up to $100 million a year.

This brucellosis in cattle also called as Malta fever or Bang’s disease, caused by brucella abotus . . Affected cows abort calves late in pregnancy or give birth to weak offspring. The disease is spread when other cows lick the calves or eat grass contaminated by amniotic fluid. Bulls can be infected, but rarely spread the disease.

Unpasteurized consumption of milk of the affected cows results in brucellosis in humans. This disease can be treated with antibiotics but the duration to cure it takes time. In South Africa this disease is quite rampant, as this has not under control in cattle.

Goldbaum and his colleagues found that light exposure primes B. abortus to replicate, increasing its chances of infecting a new host. “At some point in its life cycle, the bacterium comes out of an organism, senses blue light, and prepares itself to infect another organism,” Goldbaum said.

The Brucella photosensor is made of two components: a protein called LOV (for light-oxygen-voltage) and a protein called HK (for histidine kinase). The LOV-HK protein works like other photosensing proteins. It absorbs photons of blue light and uses this energy to create a bond between itself and a nearby flavin molecule (FMN). This activates the enzyme, which then catalyzes a reaction that can alter gene expression.

To test whether B. abortus' photosensing protein was necessary for infection, the group created a strain of the bacteria that lacked LOV-HK. They cultivated this knockout strain, as well as normal bacteria, with immune cells called macrophages. The normal B. abortus replicated and infected macrophages at much higher rates than the knockout strain, confirming that the bacteria need LOV-HK for optimal replication and infection.

The group also found that growing B. abortus in the dark reduced its ability to infect macrophages.

Goldbaum and his colleagues also studied two other species of bacteria: Erythrobacter litoralis, a marine bacterium, and Pseudomonas syringae, which causes disease in a wide range of plants. In both, LOV-HK was active when the bacteria were exposed to blue light. But in contrast to Brucella, in which the photosensor remained active more than two hours after the environment was darkened, the flavin-protein bond in the other two organisms broke within about 30 minutes. The relative stability of the system in Brucella may have evolved to give the bacteria time to successfully infect another animal, Goldbaum said.

Still, the discovery was a complete surprise, Goldbaum said. The group actually was looking for an oxygen sensor. Because Brucella often survives in low-oxygen, low-nutrient environments, Goldbaum surmised that it must have a way to sense whether its immediate surroundings were suitable.

The new information has set Goldbaum on a somewhat modified road to his goal of finding out all he can about Brucella. “In the future, this research may lead to a point of attack for drug design,” he said. “But we still need to know more. We are still focused on the role of flavin metabolism on virulence. And we are still looking for an oxygen sensor.”

"GENES FROM BACTERIA ARE FOUND IN ANIMALS"

some insects and roundworms pick up DNA from bacteria living within their cells, new research shows.

The DNA transfer occurs in the animals' egg cells, so the genetic modification passes between generations. The mechanism therefore provides an alternative to mutation of existing DNA as a way for the species to acquire new genetic traits.

Gene swapping is ubiquitous among bacteria and other single-celled organisms. Even plants and fungi are known to occasionally adopt a piece of foreign DNA. But scientists thought that multicellular animals picked up genes from bacteria only rarely.

"Our data are indicating that [DNA transfer] is going on all the time," says John H. Werren of the University of Rochester in New York, who led the research team.

The discovery challenges the prevailing view of animal evolution, in which genetic information is passed exclusively from parents to offspring. The transfer of DNA from bacteria means that an individual could acquire and pass on genes that it had not inherited.

"We're sort of on the edge of a transformation in the field" of animal evolution, comments Laura A. Katz of Smith College in Northampton, Mass. "These sorts of data allow us to redefine the field to capture this other process going on."

Werren's team looked at several species of insects and roundworms infected by a parasitic bacterium called Wolbachia pipientis, which afflicts about 20 percent of insect species as well as many other invertebrates. The bacterium lives inside the animals' cells, including their egg cells, giving it ready access to the chromosomes that are passed on to the animals' offspring.

"I think that physical access is the key to allowing this [DNA transfer] to happen," Werren says. The way in which animals' bodies insulate their eggs and sperm from foreign bacteria is the main barrier to heritable-DNA transfer in animals, he says.

The researchers compared the genetic code of the bacterium with the code of 11 other species: four roundworms, four fruit flies, and three wasps. The team found that all but three of the fruit fly species had segments of the bacterium's genetic code embedded in their DNA.

Some of this transferred DNA is active in the host species' cells, the researchers found, but they didn't determine whether the genes serve a biological function in the host.

The team also scanned an archive of published genomes for 21 other invertebrate species and found bacterial genes in nine of them.

Such bacterial genetic code is routinely ignored during the sequencing of animals' genomes because most scientists have assumed that the foreign DNA is a sign of contamination, Werren says. However, the new research rules out the possibility of contamination, Katz says. "I think it's a really beautifully done, elegant study."

Julie C. Dunning Hotopp, a member of the research team and a scientist at the J. Craig Venter Institute in Rockville, Md., says that the mechanism by which DNA leaves the bacteria and becomes inserted into the host species' chromosomes remains uncertain.

While in-cell parasites such as W. pipientis are common among invertebrates, none is known to infect people or other mammals, Werren says.

SOURCE:Science news

if this is the case how can we say that the genetic material which has been transferred to the next generations belong to the particular animal is it's own?

"THIRSTY FEMALE BEETLES QUENCH THIRST BY HAVING SEX"

Female beetles mate to quench their thirst, literally.

In some insect species, including certain beetles, moths and crickets, the males produce exceptionally large ejaculates that can account for up to 10 percent of their body weight.

A new study, published in the August issue of the journal Animal Behavior, reveals that dehydrated bruchid beetles accept sexual invitations simply to snag the water in a mate's seminal fluid.

It's the insect-world version of gold digging.

Martin Edvardsson of the University of Exeter and his colleagues gave female bruchids (Callosobruchus maculatus) either unlimited access to water or limited water, with all females having free access to males for mating.

They found that thirsty females mated 40 percent more frequently than those with free access to water.

Like sponges, females can absorb the water from seminal fluid through their reproductive tracts. The more water they take in, the less frequently they need to mate, an activity that's physically damaging to the females. (The males have spines on their genitalia that puncture females' reproductive tract during mating.)

That decrease in mating frequency also can be advantageous for a male, since the longer a female goes without mating with another male, the greater will be his chances of successful fertilization.

By delivering a deluge of water with the sperm that thereby also slakes a female's thirst, a male can help ensure his sperm has more time to fertilize the eggs without competing sperm from future mates.

Like other insects, the female bruchid beetles can store viable sperm for long periods of time before fertilizing their eggs. Past research has shown that a larger proportion of eggs will be fertilized by the last male to mate when there are long intervals between matings.

"The large ejaculates may have evolved because males can make it less beneficial for females to remate by providing them with a large amount of water," Edvardsson said.

While traditional nuptial gifts are thought to entice a female to mate or invest in the resulting offspring, the beetles' watery offerings act to prevent females from mating with other males.

SOURCE:Imaginova corp

kash main bhi ek male beetle hota?