Category: Science

Dog’s dinner was key to domestication

On By A.P.In DNA, Dogs, domestication, Dr. Lutter, gene, Nature, ScienceLeave a comment

dog

Dogs now have an excuse for waiting under the dinner table: domestication may have adapted them to thrive on the starch-filled foods that their owners eat.

A study published in Nature found that dogs possess genes for digesting starches, setting them apart from their carnivore cousins — wolves.

The authors say the results support the contentious idea that dogs became domesticated by lingering around human settlements. “While it’s possible that humans might have gone out to take wolf pups and domesticated them, it may have been more attractive for dogs to start eating from the scrap heaps as modern agriculture started,” says Kerstin Lindblad-Toh, a geneticist at Uppsala University in Sweden, who led the work.

Canine-domestication researchers agree that all dogs, from beagles to border collies, are the smaller, more sociable and less aggressive descendants of wolves. But neither the time nor the location of the first domestication is known: fossils place the earliest dogs anywhere from 33,000 years ago in Siberia to 11,000 years ago in Israel, whereas DNA studies of modern dogs put domestication at least 10,000 years ago, and in either Southeast Asia or the Middle East. Many researchers believe that dogs were domesticated more than once, and that even after domestication, they occasionally interbred with wild wolves.

Lindblad-Toh and her team catalogued the genetic changes involved in domestication by looking for differences between the genomes of 12 wolves and 60 dogs from 14 different breeds. Their search identified 36 regions of the genome that set dogs apart from wolves — but are not responsible for variation between dog breeds.

Nineteen of those regions contained genes with a role in brain development or function. These genes, says Lindblad-Toh, may explain why dogs are so much more friendly than wolves. Surprisingly, the team also found ten genes that help dogs to digest starches and break down fats. Lab work suggested that changes in three of those genes make dogs better than meat-eating wolves at splitting starches into sugars and then absorbing those sugars.

Most humans have also evolved to more easily digest starches. Lindblad-Toh suggests that the rise of farming, beginning around 10,000 years ago in the Middle East, led to the adaptations in both species. “This is a striking sign of parallel evolution,” she says. “It really shows how dogs and humans have evolved together to be able to eat starch.”

However, Greger Larson, an evolutionary archaeologist at Durham University, UK, very much doubts that genes involved in digesting starches catalysed domestication, pointing out that the earliest dog fossils predate the dawn of agriculture. His team plans to analyse DNA preserved in dog fossils, to discover when the genetic variations involved in domestication first emerged.

Robert Wayne, a geneticist at the University of California, Los Angeles, who is also studying ancient dog genomes, says that starch metabolism could have been an important adaptation for dogs. However, he thinks that such traits probably developed after behavioural changes that emerged when humans first took dogs in, back when most of our forebears still hunted large game.

Nevertheless, the study adds to evidence that dogs should not eat the same food as wolves, says Wayne, who points out that dog food is rich in carbohydrates and low in protein compared with plain meat. “Every day I get an email from a dog owner who asks, should they feed their dog like a wolf,” says Wayne. “I think this paper answers that question: no.”

http://www.nature.com/news/dog-s-dinner-was-key-to-domestication-1.12280

Thanks to Dr. Lutter for bringing this to the attention of the It’s Interesting community.

What hyperspace would really look like

On By A.P.In Albert Einstein, Big Bang, cosmic microwave background radiation, Doppler Effect, hyperdrive, hyperspace, Journal of Physics Special Topics, Katie Dexter, Millenium Falcon, Riley Connors, Science, Space and Time, speed of light, Star Trek, Star Wars, Theory of Special Relativity, University of Leicester, warp driveLeave a comment

Hyperdrive-yes

The science fiction vision of stars flashing by as streaks when spaceships travel faster than light isn’t what the scene would actually look like, a team of physics students says.

Instead, the view out the windows of a vehicle traveling through hyperspace would be more like a centralized bright glow, calculations show.

The finding contradicts the familiar images of stretched out starlight streaking past the windows of the Millennium Falcon in “Star Wars” and the Starship Enterprise in “Star Trek.” In those films and television series, as spaceships engage warp drive or hyperdrive and approach the speed of light, stars morph from points of light to long streaks that stretch out past the ship.

But passengers on the Millennium Falcon or the Enterprise actually wouldn’t be able to see stars at all when traveling that fast, found a group of physics Masters students at England’s University of Leicester. Rather, a phenomenon called the Doppler Effect, which affects the wavelength of radiation from moving sources, would cause stars’ light to shift out of the visible spectrum and into the X-ray range, where human eyes wouldn’t be able to see it, the students found.

“The resultant effects we worked out were based on Einstein’s theory of Special Relativity, so while we may not be used to them in our daily lives, Han Solo and his crew should certainly understand its implications,” Leicester student Joshua Argyle said in a statement.

The Doppler Effect is the reason why an ambulance’s siren sounds higher pitched when it’s coming at you compared to when it’s moving away — the sound’s frequency becomes higher, making its wavelength longer, and changing its pitch.

The same thing would happen to the light of stars when a spaceship began to move toward them at significant speed. And other light, such as the pervasive glow of the universe called the cosmic microwave background radiation, which is left over from the Big Bang, would be shifted out of the microwave range and into the visible spectrum, the students found.

“If the Millennium Falcon existed and really could travel that fast, sunglasses would certainly be advisable,” said research team member Riley Connors. “On top of this, the ship would need something to protect the crew from harmful X-ray radiation.”

The increased X-ray radiation from shifted starlight would even push back on a spaceship traveling in hyperdrive, the team found, slowing down the vehicle with a pressure similar to the force felt at the bottom of the Pacific Ocean. In fact, such a spacecraft would need to carry extra energy reserves to counter this pressure and press ahead.

Whether the scientific reality of these effects will be taken into consideration on future Star Wars films is still an open question.

“Perhaps Disney should take the physical implications of such high speed travel into account in their forthcoming films,” said team member Katie Dexter.

Connors, Dexter, Argyle, and fourth team member Cameron Scoular published their findings in this year’s issue of the University of Leicester’s Journal of Physics Special Topics.

http://www.livescience.com/26272-star-wars-hyperspace-physics-reality.html

Facial morphology associated with brown eyes make people be perceived as more trustworthy

On By A.P.In blue eyes, brown eyes, Charles University, Czech Republic, facial morphology, honesty, Plos One, trustworthinessLeave a comment

IMG_0240-Version-2

In a study recently published in PLoS ONE, researchers from from Charles University in the Czech Republic had 238 participants rate the faces of 80 students for trustworthiness, attractiveness, and dominance. Not surprisingly, they found that the three measures correlated well with each other, with faces rating high on one scale rating high on the other two. Female faces were generally more trustworthy than male ones. But that’s wasn’t all. A much more peculiar correlation was discovered as they looked at the data: brown-eyed faces were deemed more trustworthy than blue-eyed ones.

It didn’t matter if the judge was male or female, blue-eyed or brown-eyed. Even accounting for attractiveness and dominance, the result was the same: brown-eyed people’s faces were rated more trustworthy. There was some evidence of in-group bias, with blue-eyed female faces receiving lower ratings from brown-eyed women than from blue or green-eyed ones, but this difference didn’t drive the phenomenon. All the participants, no matter what eye color they had or how good-looking they thought the face was agreed that brown-eyed people just appear to look more reliable.

The real question is why? Is there a cultural bias towards brown eyes? Or does eye color really correlate somehow with personality traits like accountability and honesty? Does eye color really matter that much?

To find out, the scientists used computer manipulation to take the same faces but change their eye colors. Without changing traits other than hue of the iris, the researchers swapped the eye colors of the test faces from blue to brown and vice versa. This time, the opposite effect was found. Despite the strange correlation to eye color, the team found that eye color didn’t affect a photo’s trustworthiness rating. So it isn’t the eye color itself that really matters—something else about brown-eyed faces makes them seem more dependable.

To get at what’s really going on, the researchers took the faces and analyzed their shape. They looked at the distances between 72 facial landmarks, creating a grid-like representation of each face. For men, the answer was clear: differences in face shape explained the appeal of brown eyes.

Shape changes associated with eye color and perceived trustworthiness, from the grid-based facial shape analysis done by the researchers. Note the similarities between the shapes of brown-eyed faces and trustworthy ones.

“Brown-eyed individuals tend to be perceived as more trustworthy than blue-eyed ones,” explain the authors. “But it is not brown eyes that cause this perception. It is the facial morphology linked to brown eyes.”

Brown-eyed men, on average, have bigger mouths, broader chins, bigger noses, and more prominent eyebrows positioned closer to each other, while their blue-eyed brethren are characterized by more angular and prominent lower faces, longer chins, narrower mouths with downward pointing corners, smaller eyes, and more distant eyebrows. The differences associated with trustworthiness are also how our faces naturally express happiness—an upturned mouth, for example—which may explain why we trust people who innately have these traits.

Although the trend was the same for female faces, researchers didn’t find the same correlation between trustworthiness and face shape in women. This result is puzzling, but female faces were overall much less variable than male faces, so it’s possible the statistical analyses used to test for correlation were hampered by this. Or, it’s possible that something else is in play when it comes to the trustworthiness of female faces. The researchers hope that further research can shed light on this conundrum.

Given the importance of trust in human interactions, from friendships to business partnerships or even romance, these findings pose some interesting evolutionary questions. Why would certain face shapes seem more dangerous? Why would blue-eyed face shapes persist, even when they are not deemed as trustworthy? Are our behaviors linked to our bodies in ways we have yet to understand? There are no easy answers. Face shape and other morphological traits are partially based in genetics, but also partially to environmental factors like hormone levels in the womb during development. In seeking to understand how we perceive trust, we can learn more about the interplay between physiology and behavior as well as our own evolutionary history.

http://blogs.scientificamerican.com/science-sushi/2013/01/09/brown-eyes-deemed-more-trustworthy-but-thats-not-the-whole-story/

DARPA eyes pop-up deep sea sensors with project Upward Falling Payloads

On By A.P.In DARPA, Defense Advanced Research Projects Agency, Engineering, Inventions, Kebmodee, marine biology, ScienceLeave a comment

nextgov-medium

In a proposal almost as fanciful as the fictional 20,000 Leagues Under the Sea by Jules Verne, the Defense Advanced Research Projects Agency kicked off a research project last Friday to develop sensor systems that could be placed miles below the surface of the ocean and activated when needed by a remote command.

DARPA said it wants to develop a system that can store unmanned sensors such as waterborne or airborne cameras, decoys, network nodes, beacons and jammers, in watertight capsules that can withstand pressure at depths up to six kilometers (3.7 miles) and then be launched to the surface “after years of dormancy.”

Nearly half of the world’s oceans have depths deeper than 4 kilometers (2.5 miles), DARPA said, “which provides a “vast area for concealment of storage” and this concealment “also provides opportunity to surprise maritime targets from below, while its vastness provides opportunity to simultaneously operate across great distance,” DARPA said.

The agency said it envisions the subsystems of its Upward Falling Payloads projects will consist of a sensor payload, a “riser” providing pressure tolerant encapsulation of the payload and a communication system triggering launch of the payload stored on a container with an inner, 4-7/8 inch diameter and a length of 36 inches.

In the first stage of the three-phase project expected to cost no more than $1.75 million, DARPA wants researchers to concentrate on a communications system that avoids “false triggers” of the deep-sea systems and can operate at long distances from the submerged sensors. Proposals for this phase also should detail the design of a capsule and riser system that will work after sitting for years on the seabed, and potential sensor systems for military or humanitarian use.

The second phase of the project calls for the communication system to “wake up” the system on the seabed and launch it, with tests planned the Western Pacific in 2015 and 2016,though tests also could be conducted in the Atlantic or offshore from Hawaii, DARPA said.

In the third phase, planned for 2017, DARPA plans tests of a completely integrated and distributed Upward Falling Payloads system at full depth in the Western Pacific.

Proposals are due March 12 and DARPA expects to make an award in June.

http://www.nextgov.com/defense/2013/01/darpa-eyes-pop-deep-sea-sensors/60655/

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.

Application of Einstein’s theory of relatively to make a new type of clock may finally allow precise definition of the kilogram

On By A.P.In atomic clock, clock, Einstein, kilogram, physics, ScienceLeave a comment

sn-particlemass

A Rolex is nice, but this is a truly elegant timepiece. A new type of clock keeps time by weighing the smallest bits of matter, physicists report. Compared with standard atomic clocks, which work differently, the new clock keeps lousy time. However, by connecting mass and time the technique could lead to a quantum-mechanical redefinition of the kilogram.

“This gorgeous experiment shows that the road to redefining the kilogram is opening up,” says John Hall, a physicist at JILA, a laboratory run jointly by the University of Colorado, Boulder, and the National Institute of Standards and Technology.

A standard atomic clock takes advantage of the fact that an atom can absorb electromagnetic radiation such as light at certain frequencies as its internal structure jumps from one “quantum state” to another. The clock essentially exposes atoms to radiation tuned to such a frequency, which then serves as the ticking of the clock. The atomic clocks that keep official world time are accurate to 3 parts in 1016, so they would gain or lose less than a second in 100 million years.

It should be possible to keep time in a different way, says Holger Müller, a physicist at the University of California, Berkeley. Any massive particle must be described by a quantum wave that oscillates up and down even if the particle just sits there. The heavier the atom is, the higher the frequency of that flapping, which is known as the Compton frequency. In principle, the quantum oscillation can be used to keep time.

In practice, the Compton frequency for an atom is far too high to be measured by any electronic counter—something like a million-billion-billion cycles per second. So Müller, his student Shau-Yu Lan, and colleagues devised a way to track it in an experiment that exploits Albert Einstein’s theory of relativity, as they report online this week in Science.

The researchers start with a puff of cesium atoms that falls through space toward a detector. Along the way, the atoms encounter pulses of two opposing lasers with slightly different frequencies that gently nudge the atoms without making their inner structure change. The pulses split the cloud in two, and one half of the cloud falls as normal. The other gets pushed up away from the first half and then gets pushed back toward it to catch up.

Here’s where the relativity enters. From the perspective of the un-nudged half of the cloud, the second half moves away and then moves back. Because that second half is moving at a few centimeters per second, its time should appear to slow down just a bit thanks to the weird time dilation predicted by Einstein’s theory of special relativity. So the quantum wave for that half of the cloud oscillates slightly slower than the one for the first half of the cloud.

When the clouds recombine, that difference in oscillations affects how they overlap and “interfere.” If the researchers tune the difference in the two lasers’ frequency just right, the recombining waves will interfere “constructively” so that the cloud falls into the detector. And in that condition, a simple equation relates the “difference frequency,” which can be read out like a clock’s ticking, to the Compton frequency of the atoms and the much lower average frequency of the two lasers.

This is almost what the researchers want, except for the presence of the pesky average frequency of the lasers. So long as that frequency remains as an independent input, the whole scheme relies on whatever clock is used to set it, and is not itself an independent clock. To get around that problem, the researchers employ an elaborate feedback system called a frequency comb that fixes the average frequency of the lasers at a known multiple of the difference frequency. The average laser frequency then drops out of the equation, leaving the difference frequency set to a known fraction of the Compton frequency. The rate of the clock’s ticking is thus set by the cesium atom’s mass alone.

The experiment is a “tour de force,” says Hall, who shared the Nobel Prize in physics in 2005 for his role in developing the frequency comb. However, the rig’s precision is only a part in 100 million, he says, so any claim that it can compete with atomic clocks “leads one to believe that smoking a certain substance is legal in California.”

The real value of the approach may come in redefining the kilogram, Hall says. The kilogram is the last physical unit in the International System of Units defined by a physical artifact, a platinum-iridium cylinder kept by the International Bureau of Weights and Measures in Sèvres, France. But that standard has been getting steadily lighter over the decades as it is repeatedly cleaned, he says.

The measurement of the Compton frequency offers another way to define the unit. Researchers could simply define Planck’s constant, the number that needs to be multiplied by that frequency to get an atom’s mass. A measurement of an atom’s Compton frequency would then give an exact value of its mass in kilograms. In fact, Müller’s experiment can be reinterpreted as a measurement of Planck’s constant within the existing unit system, Hall says. A team led by François Biraben of the École Normale Supérieure in Paris has used a very similar technique to produce a better measurement, he adds.

Even if the kilogram is redefined in this way, it will still take work to translate it to the macroscopic scale of everyday life. “There’s a long way to go from a microscopic mass of an atom to something you can take to the supermarket to guarantee that when you buy a kilogram of sugar, it’s a kilogram,” says Steven Cundiff, a physicist at JILA. Researchers with a kilogram-definition initiative called the Avogadro Project are trying bridge this gap by fashioning spheres of silicon containing precise numbers of atoms. If scientists can nail down the mass of the silicon atom, the spheres would translate that mass to the macroscopic scale.

http://news.sciencemag.org/sciencenow/2013/01/new-type-of-clock-keeps-time-by-.html?ref=hp

Researchers look down a different path for new antidepressants

On By A.P.In Carver College of Medicine, Depression, Drugs, Inventions, Iowa, Iowa City, Medicine, neurogenesis, Neuropsychiatric Disease, Science, serotonin, SSRI, The Brain, University of Iowa, University of Iowa Hospitals and ClinicsLeave a comment

hippneuron-640x447

As a teenager growing up in New Mexico, Zach Weinberg had the same thing for breakfast every day of high school. Next to his tortilla and cream cheese, which he insists is delicious, was a small, round, yellow pill – an antidepressant called Lexapro. By his senior year, the only thing different was the color of his pill, now a shiny white. This one was Wellbutrin. He’d traded one antidepressant for another. If the pills work, they certainly don’t work for long. Now, at age 23, he’s frustrated at still having to play around with different drug combinations and doses.

The odds are that you know someone in the same situation. According to the National Institutes of Health, approximately one in 10 men and one in four women in the U.S. will suffer from depression at some point in their lives. Clinical depression can come at any time, lasting anywhere from months to years, and is characterized by low self-esteem and a loss of interest in things that were once enjoyable.

Along with various forms of therapy, antidepressant drugs are the most effective treatment. But even when they work, they come with side effects – such as weight gain and trouble sleeping – that can make the symptoms of depression worse. So for people like Weinberg, choosing between one kind of antidepressant and another isn’t really much of a choice.

But that may be changing. New insights into how traditional antidepressants – including the wildly popular SSRIs, or selective serotonin reuptake inhibitor, drugs like Prozac, Paxil and Lexapro – work inside the brain are stimulating the development of a new generation of medications that may work faster and more effectively.

Contrary to what their developers originally thought, many antidepressants have a surprising, indirect way of altering brain chemistry: by stimulating the growth of new neurons and protecting those neurons from dying. “The SSRI hypothesis is really falling apart,” says Paul Currie, a neuroscientist at Reed College in Portland, Ore. He explains that these new ideas have researchers trying something a little different to treat depression.

SSRIs work by manipulating serotonin, one of the most important chemical messengers in the brain. Serotonin is at least partly responsible for everything from eating disorders to the pretty colors and patterns people see while on psychedelic drugs.

When serotonin is released from one neuron and picked up by another in the course of transmitting a message between them, some is taken back up into the original neuron. By blocking this mechanism, SSRIs force more serotonin to circulate in the system, supposedly reducing feelings of depression.

Similar drugs use the same reuptake-blocking technique with other neurotransmitters, usually dopamine and norepinephrine. The success of drugs that target this system provides the basis of the monoamine hypothesis of depression – the idea that depression is a result of a chemical imbalance. That’s why decades of research have been aimed at balancing out our monoamine neurotransmitters, including serotonin.

But it takes a week or two for antidepressants to have any noticeable effect, suggesting that it’s not that immediate boost in serotonin that’s making people feel better. Recently, studies have suggested a different explanation: using antidepressants seems to correlate with having more new neurons in the hippocampus, an area of the brain responsible for many memory processes. Those suffering from depression tend to lose neurons in their hippocampi, so researchers have started to think that the effectiveness of monoamine drugs actually comes from their repairing of damaged brain areas.

Rene Hen is one of those curious researchers. A neuroscientist at Columbia University, Hen used radiation to block neurogenesis – the process of growing, repairing, and protecting new neurons – in mice. Later, when given antidepressants, these mice still showed signs of anxiety and depression, unlike the mice that were generating new neurons. This suggested that neurogenesis is actually essential for antidepressants to have any effect. Instead of waiting for the slower, indirect effect on neurogenesis patients get from SSRIs, researchers are now experimenting with drugs that take more direct routes to stimulate neuron growth.

“If you don’t have to do it through the back door, then absolutely that’s the way to go,” says Reed’s Currie. The aim now is to nail down the indirect effect that Hen identified and make it as direct as possible.

And the first drugs specifically targeting neurogenesis for all sorts of disorders, including depression, are starting to appear. In 2010, Andrew Pieper, a psychiatrist at the University of Iowa, ran a massive screening test on 1,000 small molecules. He discovered eight that had positive effects on neurogenesis in the hippocampus. He picked one, called P7C3, and ran with it. When given to mice that lacked a gene necessary for neurogenesis, P7C3 helped them create new neurons and keep them alive.

“There’s a huge unmet need for treatments that block cell death,” Pieper says. And the hope is that treatments for depression derived from P7C3 will work faster, better, and with fewer side effects than SSRIs. Although Peiper and his team have only tested P7C3 on mice, he’s optimistic about its effects in humans and is on the hunt for a commercial partner to develop it.

Neuralstem Inc., a Maryland-based pharmaceutical company, has just announced that their first round of human clinical testing on a similar drug was successful. Their drug, NSI-189, targets neurogenesis in the hippocampus by actually creating new neurons and has been successful in animal models, but these are the first tests in humans.

Despite the early success of these treatments, other scientists are concerned that a drug targeting neurogenesis might be meddling with that system prematurely. “I’m a little worried that, again, we have an oversimplified model,” Currie says. It’s like stirring up a bowl of soup, he continues, “without any thought as to what makes it taste good.”

Brian Luikart at Dartmouth College’s Geisel School of Medicine agrees. “One possibility,” he says, “is that there are global changes in the brain that enhance neurogenesis in the hippocampus.” If that’s true, then more neurogenesis could just be one of many effects of SSRIs without being the key to their success. Although the links between neurogenesis and antidepressants are well established, there is still no evidence to suggest that solely enhancing neurogenesis can help fight depression in humans. “Increasing neurogenesis does not increase happiness,” he says.

Luikart also worries that, while a neurogenesis drug may have fewer side effects, the ones it does have could be even more damaging – especially for cancer patients. A drug that keeps neurons alive could potentially do the same to tumor cells.

But Pieper says he hasn’t seen any negative effects. Neuralstem also says there haven’t been any health concerns in their trials. And even if there are side effects like those Luikart is worried about, it might be worth the risk for those with severe depression.

Neurogenesis drugs are still years from being commercially available, however. Pieper’s is still in pre-clinical testing, and Neuralstem’s, while farther along, is still years away from patients. Until then, Zach Weinberg and the rest of us are just going to have to stick with our reuptake inhibitors and cream cheese tortillas.

Shiny happy neurons

Many researchers taking a different view of pedophilia

On By A.P.In Anton Schweighofer, Center for Mental Health and Addiction in Toronto, child abuse, Crime, Dr. Fred Berlin, Dr. Russell Swerdlow, height, Institute of Sexology and Sexual Medicine in Berlin, James Cantor, Johns Hopkins Sexual Behaviors Consultation Unit, left handedness, Medicine, Neuropsychiatric Disease, pedophilia, phallometry, Project Dunkelfeld, Science, The BrainLeave a comment

13xmIBc_1_www_large_thumb

Despite a stable home life in suburban Chicago, Paul Christiano was tortured by urges he knew could land him in prison. In 1999, he was caught buying child pornography. Now 36, he said he has never molested a child, but after five years of state-ordered therapy, the attraction remains. (Alex Garcia, Chicago Tribune / December 14, 2012)

As a young boy, Paul Christiano loved the world of girls — the way they danced, how their spindly bodies tumbled in gymnastics.

In adolescence, as other boys ogled classmates, he was troubled to find himself fantasizing about 7- to 11-year-olds.

His desires remained stuck in time as he neared adulthood. Despite a stable home life in suburban Chicago, he was tortured by urges he knew could land him in prison.

“For having these feelings, I was destined to become a monster,” he said. “I was terrified.”

In 1999, Christiano was caught buying child pornography. Now 36, he said he has never molested a child, but after five years of state-ordered therapy, the attraction remains.

“These people felt they could snuff out the desire, or shame me into denying it existed,” he said. “But it’s as intrinsic as the next person’s heterosexuality.”

In the laboratory, researchers are coming to the same conclusion.

Like many forms of sexual deviance, pedophilia once was thought to stem from psychological influences early in life. Now, many experts view it as a sexual orientation as immutable as heterosexuality or homosexuality. It is a deep-rooted predisposition — limited almost entirely to men — that becomes clear during puberty and does not change.

The best estimates are that between 1% and 5% of men are pedophiles, meaning that they have a dominant attraction to prepubescent children.

Not all pedophiles molest children. Nor are all child molesters pedophiles. Studies show that about half of all molesters are not sexually attracted to their victims. They often have personality disorders or violent streaks, and their victims are typically family members.

By contrast, pedophiles tend to think of children as romantic partners and look beyond immediate relatives. They include chronic abusers familiar from the headlines — Catholic priests, coaches and generations of Boy Scout leaders.

Other pedophiles are “good people who are struggling,” said Dr. Fred Berlin, a psychiatrist who heads the Johns Hopkins Sexual Behaviors Consultation Unit. “They’re tortured souls fighting like heck not to do this. We do virtually nothing in terms of reaching out to these folks. We drive it underground.”

Some of the new understanding of pedophilia comes from studies done on convicted sex criminals at the Center for Mental Health and Addiction in Toronto, where researchers use a procedure known as phallometry to identify men whose peak attraction is to children.

A man sits alone in a room viewing a series of images and listening to descriptions of various sexual acts with adults and children, male and female, while wearing a device that monitors blood flow to his penis.

Like men attracted to adults, nearly all pedophiles respond most strongly to one gender or the other — females far more often than males.

In searching for causes of pedophilia, researchers have largely dismissed the popular belief that abuse in childhood plays an important role. Studies show that few victims grow up to be abusers, and only about a third of offenders say they were molested.

Scientists at the Toronto center have uncovered a series of associations that suggest pedophilia has biological roots.

Among the most compelling findings is that 30% of pedophiles are left-handed or ambidextrous, triple the general rate. Because hand dominance is established through some combination of genetics and the environment of the womb, scientists see that association as a powerful indicator that something is different about pedophiles at birth.

“The only explanation is a physiological one,” said James Cantor, a leader of the research.

Researchers have also determined that pedophiles are nearly an inch shorter on average than non-pedophiles and lag behind the average IQ by 10 points — discoveries that are consistent with developmental problems, whether before birth or in childhood.

In a 2008 study, Cantor’s team conducted MRI brain scans on 65 pedophiles. Compared with men with criminal histories but no sex offenses, they had less white matter, the connective circuitry of the brain.

The evidence also points to what Cantor explained as “cross wiring”: Seeing a child sets off the same neural response that men typically experience around an attractive woman.

More evidence of brain involvement comes from scattered examples of men with brain tumors or neurological diseases affecting inhibition.

In one case, a 40-year-old teacher in Virginia with no history of sexual deviance suddenly became interested in child pornography and was arrested for molesting his prepubescent stepdaughter.

The night before his sentencing, he showed up at an emergency room with a bad headache. An MRI revealed a tumor compressing his brain’s right frontal lobe.

When the tumor was removed, his obsession faded, according to Dr. Russell Swerdlow, a neurologist on the case. A year later he again became sexually fixated on children. The tumor was growing back.

Swerdlow and others said the case suggests that the man’s attraction to children may have always been present — the tumor simply took away the man’s ability to control it.

Strong impulse control may help explain why some pedophiles never break the law.

Most clinicians have given up on changing the sexual orientation of pedophiles in favor of teaching the how to resist their unacceptable desires.

Experts believe that pedophiles who also have a significant attraction to adults stand the best chance of staying out of trouble, because of their capacity for some sexual fulfillment that is legal. For others, injections of hormones to reduce sex drive are often recommended.

Most pedophiles, however, don’t receive any attention until they’ve been arrested.

In an attempt to change that, sex researchers in Germany launched an unusual media campaign in 2005.

“You are not guilty because of your sexual desire, but you are responsible for your sexual behavior,” said billboards urging them to contact the Institute of Sexology and Sexual Medicine in Berlin. “There is help! Don’t become an offender!”

More than 1,700 men have responded to the print, television and online ads for Project Dunkelfeld — literally “dark field.” As of August, 80 had completed a one-year program aimed at teaching them to control their impulses. Some received hormone shots. Compared to men still on the waiting list, those who received treatment were deemed less likely to molest children, according to an analysis of risk factors.

The German researchers promise patients confidentiality. About half of those assessed admitted to having already molested a child.

Though extolled by many researchers, the same program could not be conducted in the United States or many other countries, where clinicians and others are required by law to notify authorities if they suspect a child has been or could be harmed.

There have been some grass-roots efforts to bring pedophilia out of the shadows. Anton Schweighofer, a psychologist in British Columbia, said he recently referred one of his patients to Virtuous Pedophiles, an online support group for men who have never acted on their desires and want to keep it that way.

“I just don’t want to get myself in trouble,” said the man, a factory worker who spoke on the condition that he not be identified. “I really don’t want to harm anybody.”

For many pedophiles, a fundamental part of life will always be a shameful secret.

In his late teens, Christiano taught gymnastics and supervised hundreds of young girls. He fasted at work to distract himself from his erotic feelings.

“My hand never slipped,” he said. “There were students I loved and adored. In a perfect world, I could sweep them off their feet and live happily ever after.”

In this world, however, he has tried to commit suicide three times, he said.

In 1999, he stepped into a federal sting operation when he ordered pornography. He avoided prison but was permanently added to the Illinois sex offender registry.

Once lauded in the Chicago press for his promise as a dance choreographer, Christiano now lives off unemployment, help from his parents and low-paying jobs. He has lost apartments and jobs because of his felony.

“PEDO PIECE OF GARBAGE,” read one of many emails he received after an activist group posted a notice about his case online.

His mother, Jennifer Christiano, said that as far back as she could remember, he had always been different from other boys — an odd and creative soul who loved to perform and seemed to worship his female classmates.

“I can’t tell you how hard it is,” she said. “He’s my only child. He’ll never truly be happy. He’ll never have someone he can truly love and who can love him back.”

http://www.latimes.com/news/local/la-me-pedophiles-20130115,0,197689.story?page=1&track=lat-pick

Thanks to Dr. Lutter for bringing this to the attention of the It’s Interesting community.

Huge new flying frog discovered in Vietnam

On By A.P.In Dr Jodi Rowely, Frog, Nature, New Species, Science, VietnamLeave a comment

new-flying-frog-discovered

A NEW SPECIES OF flying frog has been discovered close to Vietnam’s largest city, surprising researchers.

Dr Jodi Rowely, a biologist from the Australian Museum who led the discovery, was stunned to find the 10cm frog less than 100km from Ho Chi Minh City, one of South East Asia’s largest urban centres with a population of over 9 million people.

“To discover a previously unknown species of frog, I typically have to climb rugged mountains, scale waterfalls and push my way through dense and prickly rainforest vegetation,” says Jodi.

“I certainly didn’t expect to find a new species of frog sitting on a fallen tree in lowland forest criss-crossed by a network of paths made by people and water buffalo, and completely surrounded by a sea of rice paddies,” says Jodi.

New amphibian found near Ho Chi Minh City
The frog is bright green with a white belly and has been named Helen’s tree frog (Rhacophorus helenae) after Jodi’s mother. The discovery was published last month in The Journal of Herpetology.

Jodi said the large frog has likely evaded biologists until now by spending most of its time out of sight, in the canopy of large trees. The frog has webbed hands and feet like parachutes, allowing it to glide from tree to tree.

To date, the species had only been found in two patches of lowland forest close to Ho Chi Minh City. Lowland forests are among the most threatened habitats in the world. In 2011 the Javan Rhino which relied on lowland forests was confirmed extinct in Vietnam.

“The new species is at great risk due to ongoing habitat loss and degradation – the greatest threat to amphibians throughout Southeast Asia – but hopefully it has been discovered just in time to help protect it,” says Jodi.

http://www.australiangeographic.com.au/journal/huge-new-flying-frog-discovered-in-vietnam.htm?_tmc=s1fuf2HtTMTwOjr3WxI17LME68lov6cs-fubIOVdTCg

Meteorite has highest water concentration of any yet discovered from Mars

On By A.P.In Carl Agee, Institute of Meteoritics, Mars, Science, Science Express, Space and Time, University of New Mexico1 Comment

130103062853-mars-meteorite-story-top

A team of scientists has established a whole new class of meteorites that seems to have come from Mars’ crust, based on a rare sample from 2.1 billion years ago.

The newly analyzed meteorite has more water than any other Martian meteorite that we know of, by a magnitude of more than 10, said Carl Agee, lead study author and director of the Institute of Meteoritics at the University of New Mexico. Agee and colleagues published their analysis of the meteorite in the journal Science Express.

“There are thousands and thousands of meteorites, and so far this is the only one like it,” Agee said.

This is a volcanic rock that was probably part of an eruption, and interacted with water to the extent that some water got incorporated into the structure of the minerals, Agee said. “That’s why we’re able to see it after a couple of billion years,” he said.

The precise source of the water in the meteorite is unknown. It could have come from a lake or stream, or ground water that a volcano intruded into, Agee said. Alternatively, the water could have come from frozen Martian tundra that melted when hot volcanic material moved through it.

“We do know that there was a significant amount [of water] available,” he said.

Agee and colleagues were able to extract water from the meteorite by putting it into a vacuum-sealed tube and heating it up. Using a mass spectrometer, they were able to determine that the gas released from the heated meteorite was water vapor.

“That vapor is true Martian water that is, sort of like, being awakened” after many years, he said. “We’re pulling it out of the rock.”

Agee’s meteorite is similar to the type of rocks that NASA spacecraft have found on the surface of Mars in terms of its chemical composition. This is the first meteorite that’s a good match to those rocks on Mars today.

The meteorite’s age also makes it unique, Agee said. It from 2.1 billion years ago, making it the second-oldest sample that we have. The oldest is the Alan Hills meteorite, discovered in Antarctica in 1984, which is 4.5 billion years old. All other samples have been much younger.

Right now, Mars is cold and dry, inhospitable for life, Agee said. But many scientists believe the environment used to be warm and wet and that somewhere in its history the planet lost its atmosphere and surface water. When and how that happened are big mysteries.

“This meteorite is a sample from that transitional period, perhaps,” Agee said. “Because of the water that’s present in it, it may be giving us a glimpse of what the surface conditions were like, as well.”

The rare Mars rocks came from Morocco. There are nomads in that country who make a living by scouring the Sahara Desert for the dark, black rocks that have fallen from space, Agee explains. They bring these meteorites into towns and sell them to a dealer. Then the dealer sells them internationally to collectors, museums and scientists.

When Agee realized how rare and important his first sample was, he wanted to know if there were more. The meteorite hunters have since recovered a few more pieces.

The biggest piece of this Martian meteorite fits into the palm of your hand and weighs 320 grams (about 11 ounces), Agee said. There are two samples in his lab and two more in Paris.

“It’s going to be real interesting to see if there are more that are recovered,” he said. “But I think that this particular type is going to be extraordinarily rare.”

Meteorite has highest water content of any from Mars, scientists say

Old termites blow themselves up to save the nest

On By A.P.In Academy of Sciences of the Czech Republic in Prague, Boston, Boston University, Dr. Rajadhyaksha, exploding termite, French Guiana, James Traniello, Neocapritermes taracua termites, Northeastern University, Prague, Rebeca Rosengaus, Robert Hanus, Science, suicide, termiteLeave a comment

sn-termites

When trekking through a forest in French Guiana to study termites, a group of biologists noticed unique spots of blue on the backs of the insects in one nest. Curious, one scientist reached down to pick up one of these termites with a pair of forceps. It exploded. The blue spots, the team discovered, contain explosive crystals, and they’re found only on the backs of the oldest termites in the colony. The aged termites carry out suicide missions on behalf of their nest mates.

After their initial observation, the team carried out field studies of Neocapritermes taracua termites and discovered that those with the blue spots also exploded during encounters with other species of termites or larger predators. The researchers report online today in Science that the secretions released during the explosion killed or paralyzed opponents from a competing termite species. However, if the scientists removed the blue crystal from the termites, their secretions were no longer toxic.

Back in their labs, scientists led by biochemist Robert Hanus of the Academy of Sciences of the Czech Republic in Prague went on to show that the blue termites always had shorter, worn-down mandibles than others from the same species, indicating that they were older. Then, the researchers removed the contents of the blue pouches and analyzed them. They contained a novel protein that is unusually rich with copper, suggesting that it’s an oxygen binding-protein. Rather than being toxic itself, it likely is an enzyme that converts a nontoxic protein into something toxic.

“What happens is when the termites explode, the contents of the back pouch actually interact with secretions from the salivary gland and the mixture is what is toxic,” explains Hanus. It’s the first time two interacting chemicals have been shown responsible for a defense mechanism in termites, he says.

Researchers already knew that many social insects change roles in their colony as they age. Moreover, it’s well known that a number of species of termites explode, often oozing sticky or smelly fluid onto their opponent. But in previously observed cases, the explosive or noxious material is found in the termites’ heads, and the suicide missions are the responsibility of a distinct caste of soldier termites, not aging workers. Since N. taracua have soldiers, it’s especially surprising to see workers exploding, says Hanus.

“This is a quirky, funny natural history,” says behavioral ecologist Rebeca Rosengaus of Northeastern University in Boston, who was not involved in the study. “What’s new and interesting here is that this is found to be an aspect of colony-related age organization,” says biologist James Traniello of Boston University. And the placement and chemistry of the blue crystals is unique, he says. The findings illustrate the vast diversity of social structures and defense mechanisms that the more than 3000 species of termites have evolved over time, Traniello says.

One question that remains is exactly how aging triggers the accumulation of the blue crystals. “We’re still not 100% sure what the role of the blue protein is,” says Hanus. “That’s definitely something which we want to perform further research on.”

http://news.sciencemag.org/sciencenow/2012/07/old-termites-blow-themselves-up-.html

Thanks to Dr. Rajadhyaksha for bringing this to the attention of the It’s Interesting community.