Archive for the ‘University of Cambridge’ Category

Chronic cocaine use may speed up brain aging, a new study suggests.

British researchers scanned the brains of 60 people with cocaine dependence and 60 people with no history of substance abuse, and found that those with cocaine dependence had greater levels of age-related loss of brain gray matter.

The cocaine users lost about 3.08 milliliters (ml) of brain volume a year, nearly twice the rate of about 1.69 ml per year seen in the healthy people, the University of Cambridge researchers said.

The increased decline in brain volume in the cocaine users was most noticeable in the prefrontal and temporal cortex, regions associated with attention, decision-making, self-regulation and memory, the investigators noted in a university news release.

“As we age, we all lose gray matter. However, what we have seen is that chronic cocaine users lose gray matter at a significantly faster rate, which could be a sign of premature aging. Our findings therefore provide new insight into why the [mental] deficits typically seen in old age have frequently been observed in middle-aged chronic users of cocaine,” Dr. Karen Ersche, of the Behavioral and Clinical Neuroscience Institute at University of Cambridge, said in the news release.

The study is published in the April 25 issue of the journal Molecular Psychiatry.

Cocaine is used by as many as 21 million people worldwide, and about 1 percent of these people become dependent on the drug, according to the United Nations Office on Drugs and Crime.

While the study doesn’t conclusively prove cocaine causes brain atrophy and other symptoms of aging, the association is cause for concern, the researchers said.

“Our findings clearly highlight the need for preventative strategies to address the risk of premature aging associated with cocaine abuse. Young people taking cocaine today need to be educated about the long-term risk of aging prematurely,” Ersche said.

However, accelerated aging also affects older adults who have abused cocaine and other drugs since early adulthood.

“Our findings shed light on the largely neglected problem of the growing number of older drug users, whose needs are not so well catered for in drug treatment services. It is timely for health care providers to understand and recognize the needs of older drug users in order to design and administer age-appropriate treatments,” Ersche said.

http://health.usnews.com/health-news/news/articles/2012/04/24/cocaine-habit-might-speed-brain-aging

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mechanical gear 2

mechanical gear 1

With two diminutive legs locked into a leap-ready position, the tiny jumper bends its body taut like an archer drawing a bow. At the top of its legs, a minuscule pair of gears engage—their strange, shark-fin teeth interlocking cleanly like a zipper. And then, faster than you can blink, think, or see with the naked eye, the entire thing is gone. In 2 milliseconds it has bulleted skyward, accelerating at nearly 400 g’s—a rate more than 20 times what a human body can withstand. At top speed the jumper breaks 8 mph—quite a feat considering its body is less than one-tenth of an inch long.

This miniature marvel is an adolescent issus, a kind of planthopper insect and one of the fastest accelerators in the animal kingdom. As a duo of researchers in the U.K. reported recently in the journal Science, the issus also the first living creature ever discovered to sport a functioning gear. “Jumping is one of the most rapid and powerful things an animal can do,” says Malcolm Burrows, a zoologist at the University of Cambridge and the lead author of the paper, “and that leads to all sorts of crazy specializations.”

The researchers believe that the issus—which lives chiefly on European climbing ivy—evolved its acrobatic prowess because it needs to flee dangerous situations. Although they’re not exactly sure if the rapid jump evolved to escape hungry birds, parasitizing wasps, or the careless mouths of large grazing animals, “there’s been enormous evolutionary pressure to become faster and faster, and jump further and further away,” Burrows says. But gaining this high acceleration has put incredible demands on the reaction time of insect’s body parts, and that’s where the gears—which “you can imagine being at the top of the thigh bone in a human,” Burrows says—come in.

“As the legs unfurl to power the jump,” Burrows says, “both have to move at exactly the same time. If they didn’t, the animal would start to spiral out of control.” Larger animals, whether kangaroos or NBA players, rely on their nervous system to keep their legs in sync when pushing off to jump—using a constant loop of adjustment and feedback. But for the issus, their legs outpace their nervous system. By the time the insect has sent a signal from its legs to its brain and back again, roughly 5 or 6 milliseconds, the launch has long since happened. Instead, the gears, which engage before the jump, let the issus lock its legs together—synchronizing their movements to a precision of 1/300,000 of a second.

The gears themselves are an oddity. With gear teeth shaped like cresting waves, they look nothing like what you’d find in your car or in a fancy watch. (The style that you’re most likely familiar with is called an involute gear, and it was designed by the Swiss mathematician Leonhard Euler in the 18th century.) There could be two reasons for this. Through a mathematical oddity, there is a limitless number of ways to design intermeshing gears. So, either nature evolved one solution at random, or, as Gregory Sutton, coauthor of the paper and insect researcher at the University of Bristol, suspects, the shape of the issus’s gear is particularly apt for the job it does. It’s built for “high precision and speed in one direction,” he says. “It’s a prototype for a new type of gear.”

Another odd thing about this discovery is that although there are many jumping insects like the issus—including ones that are even faster and better jumpers—the issus is apparently the only one with natural gears. Most other bugs synchronize the quick jolt of their leaping legs through friction, using bumpy or grippy surfaces to press the top of their legs together, says Duke University biomechanics expert Steve Vogel, who was not involved in this study. Like gears, this ensures the legs move at the same rate, but without requiring a complicated interlocking mechanism. “There are a lot of friction pads around, and they accomplish pretty much of the same thing,” he says. “So I wonder what extra capacity these gears confer. They’re rather specialized, and there are lots of other jumpers that don’t have them, so there must be some kind of advantage.”

Even stranger is that the issus doesn’t keep these gears throughout its life cycle. As the adolescent insect grows, it molts half a dozen times, upgrading its exoskeleton (gears included) for larger and larger versions. But after its final molt into adulthood—poof, the gears are gone. The adult syncs its legs by friction like all the other planthoppers. “I’m gobsmacked,” says Sutton. “We have a hypothesis as to why this is the case, but we can’t tell you for sure.”

Their idea: If one of the gear teeth were to slip and break in an adult (the researchers observed this in adolescent bugs), its jumping ability would be hindered forever. With no more molts, it would have no chance to grow more gears. And with every bound, “the whole system might slip, accelerating damage to the rest of the gear teeth,” Sutton says. “Just like if your car has a gear train missing a tooth. Every time you get to that missing tooth, the gear train jerks.”

Read more: http://www.popularmechanics.com/science/environment/the-first-gear-discovered-in-nature-15916433?click=pm_latest

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

fossil

Christopher Cameron of the University of Montreal’s Department of Biological Sciences and his colleagues have unearthed a major scientific discovery — a strange phallus-shaped creature they found in Canada’s Burgess Shale fossil beds, located in Yoho National Park. The fossils were found in an area of shale beds that are 505 million years old.

Their study, published online in the journal Nature on March 13, 2013, confirms Spartobranchus tenuis is a member of the acorn worms group which are seldom-seen animals that thrive today in the fine sands and mud of shallow and deeper waters. Acorn worms are themselves part of the hemichordates, a group of marine animals closely related to today’s sea stars and sea urchins. “Unlike animals with hard parts including teeth, scales and bones, these worms were soft-bodied, so their fossil record is extremely rare,” said author Dr. Chris Cameron of the University of Montreal. “Our description of Spartobranchus tenuis, a creature previously unknown to science, pushes the fossil record of the enteropneusts back 200 million years to the Cambrian period, fundamentally changing our understanding of biodiversity from this period.”

Since their discovery in the 19th-century, some of the biggest questions in hemichordate evolution have focused on the group’s origins and the relationship between its two main branches: the enteropneusts and the pterobranchs, including graptolites. “One of the big punchlines from my graduate work, was molecular evidence that enteropneusts and pterobranchs are closely related” said Cameron, a specialist on the taxonomy, evolution and biogeography of hemichordates.

“It’s astonishing how similar Spartobranchus tenuis fossils are to modern day acorn worms, except that they also formed fibrous tubes.” The tubes provide a key missing link that connects the two main hemichordate groups. “The explosive radiation of graptolites in the Paleozoic planktonic ecosystems is known only from the diversity of their tubes. Our findings suggest that the tubes were lost in the lineage leading to modern day enteropneusts, but elaborated on in graptolites and retained to the present day in pterobranchs” added Cameron.

Hemichordates also share many of the same characteristics as chordates — a group of animals that includes humans — with the name hemichordate roughly translating to ‘half a chordate.’

“Work from my lab has shown that enteropneusts filter feed using a pharynx perforated with gill slits, just like the invertebrate chordates” added Cameron. Spartobranchus tenuisprobably fed on small particles of matter filtered from the seawater. “There are thousands of specimens at the Walcott Quarry in Yoho National Park, so it’s possible Spartobranchus tenuis may have played an important role in moving carbon from the water column to the sediment in the early Burgess Shale environment” said Cameron.

Detailed analysis suggests Spartobranchus tenuis had a flexible body consisting of a short proboscis, collar and narrow elongate trunk terminating in a bulbous structure, which may have served as an anchor. The largest complete specimens examined were 10 centimetres long with the proboscis accounting for about half a centimetre. A large proportion of these worms was preserved in tubes, of which some were branched, suggesting the tubes were used as a dwelling structure.

Other members of the Spartobranchus tenuis research team are lead author Jean-Bernard Caron of the Royal Ontario Museum and Simon Conway Morris of the University of Cambridge.

http://www.sciencedaily.com/releases/2013/03/130313141450.htm

sn-traits
Research shows a strong association between liking “curly fries” on Facebook and having high IQ.

Every day, millions of people click on Facebook “Like” buttons, boldly declaring their preferences for a variety of things, such as books, movies, and cat videos. But those “likes” may reveal more than they intend, such as sexual orientation, drug use, and religious affiliation, according to a study that analyzed the online behavior of thousands of volunteers.

Your preferences define you. Researchers have known for decades that people’s personal attributes—gender, age, religion, sexual orientation, and personality type—correlate with their choice of products, concepts, and activities. Just consider the different populations at an opera and a NASCAR race. This is why companies are so eager to gather personal information about their consumers: Advertising is far more effective when it is targeted to groups of people who are more likely to be interested in a product. The only aspect that has changed is the increasing proportion of personal information that is available as digital data on the Internet. And Facebook has become a major hub for such data through its like button. A team led by Michal Kosinski, a psychologist at the University of Cambridge in the United Kingdom as well as at Microsoft Research, wondered just how much people’s likes reveal about them.

The Likes data are public information. The hard part was getting the data on intelligence and other such attributes to compare with the likes. For that, Kosinski and his Cambridge colleague David Stillwell created a Facebook app called myPersonality. After agreeing to volunteer as a research subject, users of the myPersonality app answer survey questions and take a series of psychological tests that measure things such as intelligence, competitiveness, extraversion versus introversion, and general satisfaction with life. Kosinski and Stillwell not only get those data but also data from the user’s Facebook profile and friends network. In return, users get a peek at their own information. More than 4 million people have volunteered already.

The researchers used data from 58,000 U.S.-based myPersonality volunteers to build a statistical model. Then, they used a sample of myPersonality volunteers to test how well the model could predict personal attributes from likes.

Facebook likes are an amazingly good predictor of personal attributes, the team reports online today in the Proceedings of the National Academy of Sciences. The most accurate predictions were for gender (93%) and race (95%), as limited to Caucasian versus African American. But people’s likes also predicted far more sensitive personal attributes such as homosexuality (88% for men, 75% for women), religion (82%), political party membership (85%), and even use of cigarettes, alcohol, and drugs (73%, 70%, and 65%, respectively). Many of the likes that had the strongest prediction power make intuitive sense, such as “Jesus” for Christians and “Glee” for gay men. But others were harder to explain, such as the strong association between liking “curly fries” and having high IQ.

“What was traditionally laboriously assessed on an individual basis can be automatically inferred for millions of people without them even noticing,” Kosinski says, “which is both amazing and a bit scary.”

Science NOW contacted Facebook’s in-house social scientists about the work. The study’s results are “hardly surprising,” the company contends in their official response. “On Facebook, people can share the things they like—like bands, brands, sports teams, public figures, etc. By using Login with Facebook on third party sites, people can take their Likes and interests with them around the web—to have more personalized experiences.”

“I am glad that Facebook is aware that likes allow predicting individual traits,” Kosinski says. “I am afraid, however, that users [of Facebook and other online environments] do not realize that by ‘carrying around’ their likes, songs they listen to, Web sites they visit, and other kinds of online behavior, they are exposed to a degree potentially well beyond what they expect or would find comfortable.”

Whether people are comfortable, advertisers are sure to start paying attention to what they like, now that a Rosetta stone exists for translating it into personal data.

http://news.sciencemag.org/sciencenow/2013/03/facebook-preferences-predict-per.html

pitcher

An insect-trapping pitcher plant in Venezuela uses its downward pointing hairs to create a ‘water slide’ on which insects slip to their death, new research reveals. The research was published December 19, in the journal Proceedings of the Royal Society B.

Hairs on plants, called trichomes, are typically used to repel water. However, the Cambridge researchers observed that the hairs on the inside of Heliamphora nutans pitcher plants were highly wettable, prompting them to test whether this phenomenon is related to the trapping of insects.

They found that wetting strongly enhanced the slipperiness of the trap and increased the capture rate for ants almost three-fold — from 29 per cent when dry to 88 per cent when wet. Upon further examination, they found that the wetting affected the insects’ adhesive pads while the directional arrangement of the hairs was effective against the claws.

Dr Ulrike Bauer, lead author of the paper from the University of Cambridge, said: “When the hairs of the plant are wet, the ants’ adhesive pads essentially aquaplane on the surface, making the insects lose grip and slip into the bowl of the pitcher. This is the first time that we have observed hairs being used by plants in this way, as they are typically used to make leaves water repellent.”

They also found that the plant used a wicking method during dryer times to pull moisture from the bowl of the pitcher up to the hairy trapping surface, enabling them to capitalise on this aquaplaning effect even when there is no rain.

Dr Bauer added: “This very neat adaptation might help the plants to maximise their nutrient acquisition.”

The Heliamphora nutans pitcher plant lives on the spectacular table mountains of the Guyana Highlands in Southern Venezuela, between altitudes of 2000-2700m. The pitchers can grow up to 18 cm tall and 7 cm wide and trap mainly ants.

http://www.sciencedaily.com/releases/2012/12/121218203513.htm