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Cholera is altering the human genome

Cholera
© Mark Knobil/Creative CommonsLaid low. A cholera ward in Dhaka, Bangladesh, a country where nearly half the people are infected with the cholera bacterium by age 15.
Cholera kills thousands of people a year, but a new study suggests that the human body is fighting back. Researchers have found evidence that the genomes of people in Bangladesh - where the disease is prevalent - have developed ways to combat the disease, a dramatic case of human evolution happening in modern times.

Cholera has hitchhiked around the globe, even entering Haiti with UN peacekeepers in 2010, but the disease's heartland is the Ganges River Delta of India and Bangladesh. It has been killing people there for more than a thousand years. By the time they are 15 years old, half of the children in Bangladesh have been infected with the cholera-causing bacterium, which spreads in contaminated water and food. The microbe can cause torrential diarrhea, and, without treatment, "it can kill you in a matter of hours," says Elinor Karlsson, a computational geneticist at Harvard and co-author of the new study.

The fact that cholera has been around so long, and that it kills children - thus altering the gene pool of a population - led the researchers to suspect that it was exerting evolutionary pressure on the people in the region, as malaria has been shown to do in Africa.

Another hint that the microbe drives human evolution, notes Regina LaRocque, a study co-author and infectious disease specialist at Massachusetts General Hospital, Boston, is that many people suffer mild symptoms or don't get sick at all, suggesting that they have adaptations to counter the bacterium.

To tease out the disease's evolutionary impact, Karlsson, LaRocque, and their colleagues, including scientists from the International Centre for Diarrhoeal Disease Research in Bangladesh, used a new statistical technique that pinpoints sections of the genome that are under the influence of natural selection. The researchers analyzed DNA from 36 Bangladeshi families and compared it to the genomes of people from northwestern Europe, West Africa, and eastern Asia. Natural selection has left its mark on 305 regions in the genome of the subjects from Bangladesh, the team reveals online today in Science Translational Medicine.

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Whales flee from military sonar leading to mass strandings, research shows

Whale
© Bluegreen Pictures/Doug PerrineWhales flee from the loud military sonar used by navies to hunt submarines, research shows.
Whales flee from the loud military sonar used by navies to hunt submarines, new research has proven for the first time. The studies provide a missing link in the puzzle that has connected naval exercises around the world to unusual mass strandings of whales and dolphins.

Beaked whales, the most common casualty of the strandings, were shown to be highly sensitive to sonar. But the research also revealed unexpectedly that blue whales, the largest animals on Earth and whose population has plummeted by 95% in the last century, also abandoned feeding and swam rapidly away from sonar noise.

The strong response observed in the beaked whales occurred at noise levels well below those allowed for US navy exercises. "This result has to be taken into consideration by regulators and those planning naval exercises," said Stacy DeRuiter, at the University of St Andrews in Scotland, who led one of the teams.

"For whales and dolphins, listening is as important as seeing is for humans - they communicate, locate food, and navigate using sound," said Sarah Dolman, at charity Whale and Dolphin Conservation. "Noise pollution threatens vulnerable populations, driving them away from areas important to their survival, and at worst injuring or even causing the deaths of some whales and dolphins." Dolman said there were no accepted international standards regarding noise pollution and there was an urgent need to re-evaluate the environmental impacts of military activities.

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Chimp genetic history stranger than humans'

Great Apes
© Ian BickerstaffResearchers have sequenced the first full set of great ape genomes. Shown here: chimpanzees and gorillas.
The most comprehensive catalog of great-ape genome diversity to date offers insight into primate evolution, revealing chimpanzees have a much more complex genetic history than humans.

In a new study, researchers sequenced a total of 79 great apes, including chimpanzees, bonobos, eastern and western gorillas, orangutans and humans, as well as seven ape subspecies. The animals were wild- and captive-born individuals from populations in Africa and Southeast Asia.

Much attention has been focused on studying the diversity among human genomes, said study researcher Tomas Marques-Bonet, a geneticist at the Institut de Biologia Evolutiva in Spain. "If we want to understand the genetic diversity of humans, we need to measure the genetic diversity of our nearest relatives," Marques-Bonet said.

As part of the study, Marques-Bonet and his colleagues were looking for genetic markers corresponding to changes in a single letter in the genetic code that define a subspecies. The researchers identified millions of such markers, which are important for conservation efforts.

For instance, these markers allow people who manage wild-ape populations to identify different kinds of ape. Most of these animals are captured from illegal trade, so scientists don't know how they're related, Marques-Bonet told LiveScience.

Surprisingly, Marques-Bonet said, the genetic history of chimpanzees turned out to be much more complex than that of humans. Compared with chimps, "it looks like our [humans'] history has been really simple," Marques-Bonet said. Human populations encountered a bottleneck when they left Africa, and have since expanded to colonize the whole planet. By contrast, chimpanzee populations have undergone at least two to three bottlenecks and expansions, Marques-Bonet said.

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Neuroscientist claims human head transplants will soon be possible

Image
The idea of transplanting the human head has (so far) been left in the (fictitious) realm of the rich and crazy - see the incredibly strange 1971 horror movie The Incredible 2-Headed Transplant or its apparent 'followup' the year after The Thing with Two Heads or The Simpsons: Treehouse of Horror II in 1991 - but now an Italian neuroscientist believes that it may actually be possible.

There have been stories over the years of scientists transplanting the heads of dogs and monkeys - btw, that's between two dogs (by Vladimir Demikhov in the 1950s) and between two monkeys (by R.J. White in the 1970s), not between a dog and a monkey - with a fair amount of hype, but apparently, according to Steven Novella, from his Neurologica Blog, those weren't true transplants. For it to be a true transplant, the head has to be able to control its new body, and in those cases, it was simply that the body supplied blood to the head. In order to have control over the new body, there has to be a successful connection of the spinal cord. Without that, it's no dice.

Now, in the fictitious examples I mentioned above, Manuel Cass (the 'maniacal killer' from The Incredible 2-Headed Transplant) was an actual transplant, as he had some control over the body, but for Dr. Maxwell Kirshner in The Thing with Two Heads and Mr. Burns in Treehouse of Horror II, they were just grafted on.

However, although I've been using examples from horror movies and cartoons, there actually is some real promise for this idea, apparently.

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Commercial quantum computer actually works, according to new testing

Quantum Computer
© D-Wave
Since the Canadian company D-Wave began selling so-called quantum processors, experts have debated whether they're truly quantum. Now, according to an analysis by academic physicists they really do show quantum effects, making them the world's first commercial quantum processors.

In general, it's been difficult to confirm how D-Wave machines work because quantum states are so sensitive, measuring them may perturb them. Besides this new test, performed at the University of Southern California, a few different recent tests have gathered evidence that D-Wave processors work as advertised.

Quantum processors have quantum bits instead of the usual binary bits that traditional processors have. You know normal bits store information by taking on one of two states, often named "0" and "1." Quantum bits, also called qubits, have another capability. They are able to take on both the 0 and 1 states at the same time.

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Cluster spacecraft detects elusive space wind

SpaceWind
© ESA/ATG medialabPlasma outflow from plasmasphere to magnetosphere.
A new study provides the first conclusive proof of the existence of a space wind first proposed theoretically over 20 years ago.

By analyzing data from the European Space Agency's Cluster spacecraft, researcher Iannis Dandouras detected this plasmaspheric wind, so-called because it contributes to the loss of material from the plasmasphere, a donut-shaped region extending above the Earth's atmosphere. The results are published today in Annales Geophysicae, a journal of the European Geosciences Union (EGU).

"After long scrutiny of the data, there it was, a slow but steady wind, releasing about 1 kg of plasma every second into the outer magnetosphere: this corresponds to almost 90 tonnes every day. It was definitely one of the nicest surprises I've ever had!" said Dandouras of the Research Institute in Astrophysics and Planetology in Toulouse, France.

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How the moon affects the nocturnal world

Moon
© David Acosta Allely/ShutterstockWhile the solar cycle's effects on animal behavior are heavily studied, far less has been researched about the lunar cycle's effects.
Plenty of myths and fables have tried to explain the loony effects the moon seems to have on animals, but far fewer scientific reports have formally addressed the issue. Now, in a comprehensive review, scientists have found the indirect, and sometimes direct, ways the lunar cycle drives animal behaviors.

The review also suggests light pollution, which can block out some of the moon's glow, may disrupt natural patterns associated with Earth's only satellite.

Those who believe in true lunacy - the craziness stirred in animals by the lunar cycle - will be disappointed to learn that many animals simply adjust their behaviors in response to changes in light levels and tides, rather than to anything supernatural.

Still, other behaviors do follow more mysterious circadian clocks controlled by the lunar cycle, the team reports today (July 2) in the journal the Proceedings of the Royal Society B.

"The moon may act as a synchronizing cue between individuals, as a cue for other environmental parameters - spring tides, food availability - or simply allow animals to use vision," said Noga Kronfeld-Schor, a biologist at Tel Aviv University and co-author on the report. "The behaviors it affects are wide and diverse, ranging from long-term processes such as timing reproduction and migration to direct response to light levels."

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Pluto's moons get official names, Star Trek be damned

Pluto's Moons
© SETI Institute
A few months ago, when William Shatner, the actor who played Star Trek's Captain Kirk, heard that scientists were asking people to vote on names for Pluto's fourth and fifth moons, he lobbied that one satellite be called Vulcan, the home planet of Mr. Spock - and the name came out on top, far surpassing all others in the voting.

Today, however, scientists announced that the moons will instead bear names that better reflect Pluto's role in mythology as the god of the underworld. One satellite will be christened Kerberos, for Pluto's three-headed dog, and the other Styx, for the river dividing the world of the living from the underworld.

Kerberos is the Greek name for Cerberus, which placed number two in the voting, while Styx came in third. Why not Vulcan? Astronomers once used that name for what turned out to be a nonexistent planet inside Mercury's orbit, and its connection to the mythological Pluto was tenuous; so rejecting the name was - as Mr. Spock might say - the logical thing to do.

Comet

Comet ISON: The timelapse Hubble movie

Comet ISON
© NASA, ESA, and the Hubble Heritage Team (STScI/AURA)A false-color, visible-light image of Comet ISON taken with Hubble’s Wide Field Camera 3.
The Hubble Space Telescope team has released a video of Comet ISON is tearing toward its encounter with the Sun, zooming at 77,250 km/h (48,000 miles per hour). The comet's motion is captured in a timelapse movie, below, made from a sequence of pictures taken May 8, 2013. On that date, the comet was 650 million km (403 million miles) from Earth, between the orbits of Mars and Jupiter.

This sungrazing comet will comes closest to the Sun in November 2013, and the debate is on whether it will dazzle the skies and be visible in the daytime or fizzle out due to its close proximity to the Sun.

The movie shows a sequence of Hubble observations taken over a 43-minute span, compressed into five seconds. In that 43 minutes, the comet traveled about 55,000 km (34,000 miles). ISON streaks silently against the background stars.

Source: HubbleSite

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'Facial expression recognition' cameras to monitor emotional states of students

happy children
© unknown
Even a good teacher may not always be able to tell, at a glance, which students are quietly struggling and which need more of a challenge. Fortunately, laptops may soon come with enough emotional intelligence built in to do the job for them.

A recent study from North Carolina State University shows how this might work. Researchers there used video cameras to monitor the faces of college students participating in computer tutoring sessions. Using software that had been trained to match facial expressions with different levels of engagement or frustration, the researchers were able to recognize when students were experiencing difficulty and when they were finding the work too easy.