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Knuckle-cracking observed using MRI

Team observes cavity forming inside cracking joints for first time

A cavity forming rapidly inside our finger joints may cause the popping sound heard when cracking knuckles, according to a real-time, MRI based study published April 15, 2015 in the open-access journal PLOS ONE by Gregory Kawchuk from University of Alberta, Canada and colleagues.

Scientists have debated the cause of joint cracking for decades and to get to the root of what happens, the authors of this study used MRI video to observe for the first time what happens inside a joint when it cracks. The authors visualized ten finger joints from one participant by inserting them one at a time into a tube connected to a cable that was slowly pulled until the knuckle joint cracked.

MRI video captured each crack in real time - occurring in less than 310 milliseconds.

In every instance, the cracking and joint separation were associated with rapid creation of a gas-filled cavity within the synovial fluid, a slippery substance that lubricates the joints. "It's a little bit like forming a vacuum," Kawchuk said. "As the joint surfaces suddenly separate, there is no more fluid available to fill the increasing joint volume, so a cavity is created and that event is what's associated with the sound."

The team also observed the presence of a white flash that appears just before cracking. "No one has observed it before," says Kawchuk, an occurrence he believes is water suddenly being drawn together just before the joint cracks. Kawchuk said he'd like to use even more advanced MRI technology to understand what happens in the joint after the pop, and what it all could mean for health. The authors suggest the findings may pave the way for new research into the potential therapeutic benefits or harms of joint cracking.

High rate of healthcare visits before suicide attempts

Most people who attempt suicide make some type of healthcare visit in the weeks or months before the attempt, reports a study in the May issue of Medical Care, published by Wolters Kluwer.

The study also identifies racial/ethnic differences that may help to target suicide prevention efforts in the doctor's office and other health care settings. The lead author was Brian K. Ahmedani, PhD, LMSW, of Henry Ford Health System, Detroit, Mich.

Health Visits May Provide Chances for Suicide Prevention

Using data from the NIMH-funded Mental Health Research Network, the researchers identified nearly 22,400 individuals who made suicide attempts between 2009 and 2011. They analyzed healthcare visits before the attempt, with an eye on the possibilities for identifying people at risk for suicide.

The study focused on racial/ethnic differences in the types and timing of visits, including any documented mental health issues or substance abuse. Information on race/ethnicity was available for 78 percent of patients.

Overall, 38 percent of patients made some type of healthcare visit within a week before attempting suicide. The visit came within a month before the suicide attempt in 64 percent of patients, and within a year in nearly 95 percent. The percentage of visits with mental health or substance abuse diagnoses was about 25 percent within a week, 44 percent within a month, and 73 percent within a year before the attempt.

The study found significant racial/ethnic differences: 41 percent of white patients made any type of health visit within a week before the suicide attempt, compared to 35 percent for those in other groups. Nearly 27 percent of white patients made a mental health visit in the preceding week, compared to less than 20 percent for most other racial/ethnic groups.

Asian-Americans were the least likely to make any type of visit within a year before attempting suicide. Hawaiian/Pacific Islanders had the highest rate of hospital admissions and emergency department visits before a suicide attempt, but the lowest rate of mental health or substance abuse diagnoses.

"Overall, visits were most common in primary care and outpatient general medical settings," Dr. Ahmedani and coauthors write. Rates of visits for mental health specialty care ranged from nearly 60 percent for white to 40 percent for Asian patients.

More than one million people attempt suicide each year in the United States. The recently published National Strategy for Suicide Prevention concluded that healthcare is one of the best places to prevent suicide.

"This research provides essential information to aid suicide prevention efforts in health care systems," according to Dr. Ahmedani and coauthors. They discuss the implications for targeting suicide prevention efforts by race/ethnicity - including the need for "culturally competent mental illness detection and treatment" in minority groups.

Most previous prevention efforts have focused on emergency and mental health settings, rather than doctor's offices and other primary care settings, the researchers note. They conclude, "This study supports the promotion of suicide prevention within general outpatient settings, where most people visit before suicide attempt."

Article: "Racial/Ethnic Differences in Health Care Visits Made Before Suicide Attempt Across the United States" (doi: 10.1097/MLR.0000000000000335)

Cobalt film a clean-fuel find

Rice University discovery is efficient, robust at drawing hydrogen and oxygen from water

HOUSTON - A cobalt-based thin film serves double duty as a new catalyst that produces both hydrogen and oxygen from water to feed fuel cells, according to scientists at Rice University.

The inexpensive, highly porous material invented by the Rice lab of chemist James Tour may have advantages as a catalyst for the production of hydrogen via water electrolysis. A single film far thinner than a hair can be used as both the anode and cathode in an electrolysis device.

The researchers led by Rice postdoctoral researcher Yang Yang reported their discovery today in Advanced Materials.

They determined their cobalt film is much better at producing hydrogen than most state-of-the-art materials and is competitive with (and much cheaper than) commercial platinum catalysts. They reported the catalyst also produced an oxygen evolution reaction comparable to current materials.

"It is amazing that in water-splitting, the same material can make both hydrogen and oxygen," Tour said. "Usually materials make one or the other, but not both."

The researchers suggested applying alternating current from wind or solar energy sources to cobalt-based electrolysis could be an environmentally friendly source of hydrogen and oxygen.

"Here we can just alternate the current from positive to negative and back again, and hydrogen and oxygen are made with the same material," Tour said. "And the material itself is very easy to make." He said manufacturing the film is inexpensive and scalable.

The lab fabricated the 500-nanometer films by anodyzing a cobalt film electrodeposited on a substrate. The assembly was then baked for two hours in a phosphorus vapor that converted it to a cobalt/phosphide/phosphate thin film without damaging its porous structure. The material proved to be robust in both durability tests and in acidic and alkaline conditions, Tour said.

Graduate students Huilong Fei and Gedeng Ruan are co-authors of the paper.

Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of materials science and nanoengineering and of computer science and a member of Rice's Richard E. Smalley Institute for Nanoscale Science and Technology.

The Air Force Office of Scientific Research and its Multidisciplinary University Research Initiative supported the research.

Read the abstract at

This news release can be found online at

Neanderthal chefs may have spiced up menus with wild herbs

THE image of a Stone-Age man grasping the bony end of a bloody mammoth leg and chomping down on it with powerful gnashers is taking a bit of a battering.

15 April 2015 by Catherine Brahic

We already know that Neanderthals were partial to delicacies such as fish and small birds, with a healthy helping of plants. Now some are saying they might have flavoured their meaty feasts with wild herbs, too. Without a time machine to take us back 40,000 to 50,000 years, the suggestion remains highly speculative. But our long-lost cousins were clearly not the carnivorous beasts we once assumed them to be.

The idea that they were partial to a handful of herbs comes from the hardened plaque – or dental calculus – chipped off the teeth of a 50,000-year-old Neanderthal from El Sidrón in Spain.

A few years ago, Karen Hardy of the University of Barcelona and colleagues found traces of camomile and yarrow in the calculus – both plants with strong flavours but no nutritional value (Naturwissenschaften, They argued that the plants were eaten for medicinal purposes. Self-medication is common in the animal world, says Hardy, and it's very likely Neanderthals did the same.

Sabrina Krief of the French natural history museum in Paris, thinks differently, based on her observations of wild chimpanzees in Kibale National Park in Uganda. After a hunt, these chimps can eat up to three different types of leaf with their prey (Antiquity, Chimps are thought to self-medicate with leaves, but Krief says some scoff leaves to spice up their food.

Her rationale is that all the chimps in a group ate them at the same time, and it's unlikely that every chimp needed the same remedy. Also, different chimp tribes opt for different leaves. If chimps flavour their food, why not Neanderthals?

The palaeontologists contacted by New Scientist say this is possible but highly theoretical. What is clear is that Neanderthals were not simple carnivores. All hominins must eat carbohydrates to survive, says Hardy. Meat just doesn't provide enough energy. There's also a limit to the amount of animal protein we should have in our diet – too much meat is not good for us, says Hardy.

So at the very least, we know that Neanderthals liked some veg with their steak – though what kind of veg is still up for debate. Remains at a site in Gibraltar suggest they also liked nuts and wild olives.

And they clearly liked a variety of meats. Geoff Smith of the Monrepos archaeological research centre in Germany says they were more likely to eat bovids, horses and deer than larger game – mammoth and rhino were occasional treats. Signs that they broke up the bones of their game suggest that they sucked out the rich, fatty marrow, says Smith, who presented evidence for this at the Paleoanthropology Society meeting in San Francisco this week.

And what of their cooking techniques? Some Neanderthal sites have hearths, and Hardy's study showed signs of smoke from a wood fire and desiccated starches. They were probably well versed in the art of roasting.

Perhaps Neanderthals even boiled their food, boiling bones to extract the juices and nutrients, a bit like making a stew. "They may have done," says Wil Roebroeks of Leiden University in the Netherlands."Who knows?" The trouble, says Hardy, is we've never found a Neanderthal pot.

Palaeo toothpicks and grassy floss

CANDY floss it's not, but the Neanderthals' starchy, vegetable-rich diet was not quite what the palaeo dentist ordered. It came with a healthy helping of glucose – a fabulous source of energy to power both your brain and the bacteria that live in your mouth.

Dental plaque has always been a nuisance for hominins, says Karen Hardy of the University of Barcelona in Spain. That plaque is now allowing Hardy and other researchers to study the diets of early humans in some detail. What might Neanderthal dental hygiene have been like?

It turns out early humans were probably no strangers to the toothpick. Chimps, bonobos, orangutans, long-tailed macaques and Japanese macaques have all been seen using twigs for this purpose.

And in 2013, a team wrote that grooves in the teeth of a 1.77 million year old hominin found in Georgia were probably made by a lifetime of wielding toothpicks (PNAS,

Hardy says early humans are thought to have used bits of wood, bone, sinew and grass to pick and even floss between their teeth.

Their risk of tooth decay might also have been offset by a diet of wild plants. Farmed cereal grains tend to stick to the teeth more easily than wild foods, which can be very abrasive, says Amanda Henry of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. This suggests the palaeo diet came with its very own in-built toothbrush.

Smart drones that think and learn like us to launch this year

Mini drones with neural hardware that works like a brain could be in the skies within months – and carry out door-to-door deliveries or monitor crops

15 April 2015 by David Hambling

THAT drone buzzing round your head might be smarter than you think. Small drones with neural hardware resembling brains will soon share airspace with other aircraft, seeing and avoiding potential hazards autonomously. The ability will help drones take on a host of new roles.

Big firms like Amazon, DHL and Google are developing their own drone fleets for rapid delivery of consumer goods, fast food and pharmaceuticals. However, current rules restrict drones to flying within visual range of a human operator because of the risk of collision. Drones need an automatic "sense-and-avoid" capacity before they will be able to make deliveries on their own.

Computers capable of recognising objects in video and responding in real time are too big and too power-hungry for small drones. That means drones have to rely on short-range sensors like radar, which may not give enough warning to avoid a collision.

The key may be to mimic how animal brains work; our brains are poor at number-crunching but can process complex sensory input faster than digital systems.

Bio Inspired Technologies of Boise, Idaho, is doing just that. It is building a sense-and-avoid system using a memristor, a resistor with a memory. Like the synapse in a biological brain, the memristor changes when impulses pass through it. Crucially, it is able to remember the impulse after it has stopped.

This capability forms the basis of a learning system that mimics neurons and the connections between them. A chip-sized neural system linked to the drone's existing camera can be trained to recognise aircraft and other hazards at long range. Bio Inspired's drone should be ready for its first flight later this year.

The system can also recognise objects like clouds, birds, buildings and radio towers, and uses visual cues to estimate how far away the objects are.

"Objects like other aircraft can be catalogued in a vague sense, meaning 'I see an aircraft', or in an exact sense: 'I see another drone'," says Terry Gafron, CEO of Bio Inspired.

Equipped with this information, the drone plots a new flight path to avoid a hazard, updating it in real time as the threat moves.

"Nature seems to use this approach very effectively," says David Warne of Queensland University of Technology in Australia, who has worked with artificial neural networks that let drones recognise vegetation.

Like others in this area, much of Bio Inspired's research has been funded by the military. But it is likely that it will benefit the wider market. Sense-and-avoid will make it possible for fleets of small drones to criss-cross cities delivering packages. Like a bird or insect, a neural-enabled drone could fly to the trickiest landing place – even balconies.

Being able to recognise objects autonomously will enable a range of applications for small drones. Some of these are in the area of precision agriculture.

"The crop drone is on everyone's short list," says Gafron. Drones could survey a farm, recognise areas where crops aren't thriving and move in for a closer view to establish whether the field needs water, fertiliser or fungicide.

In the industrial field, neural drones could patrol pipelines looking for leaks, or identify electrical faults on power lines.

Closer to home, smart drones could clean windows, pick up litter, clear gutters or weed your garden, or send information to your car about which parking spaces are open. "It simply flies around town monitoring parking spaces," says Gafron.

Smart drones could even track animal populations, flying along livestock boundaries to track wolf populations for example. "Not only could the system fly autonomously, but it could conceivably tell the difference between a deer and a wolf from the air," Gafron says.

Memristor-inspired drones are not the only approach. Last year, US agency DARPA unveiled the TrueNorth neural chip developed in conjunction with IBM. This is a simulation of a neural network using digital hardware with enough neurons to match agile flyers like bees.

Survey shows half of older adults in US now taking aspirin

Over half of older adults in the United States are now taking a daily aspirin

CORVALLIS, Ore. - A national survey suggests that slightly more than half of the older adults in the United States are now taking a daily dose of aspirin, even though its use is not recommended by the Food and Drug Administration for most people who have not yet had a heart attack or stroke.

The analysis was published today in the American Journal of Preventive Medicine. It observed that aspirin use is continuing to surge, especially among adults who are using it for "primary prevention," meaning in order to prevent an initial cardiovascular event, and in some cases to prevent cancer.

In this survey of more than 2,500 respondents aged 45-75, 52 percent reported current aspirin use, and another 21 percent had used it at some point in the past. The average age of respondents in the survey was 60. A different report found that aspirin use increased 57 percent between 2005 and 2010.

Aspirin is a blood thinner and can cause bleeding events, which is a primary reason some medical experts recommend caution in its use, even at the "baby aspirin" dose of 81 milligrams often used for disease prevention. The FDA has determined that in primary use to prevent a first heart attack or stroke, for every such event that's prevented, there's approximately one major bleeding event that's caused, such as gastrointestinal bleeding.

Largely on that basis, they have concluded physicians should routinely recommend its use only to patients that have already had a heart attack or stroke. But this study found that 81 percent of older adults who are now using aspirin have not had a heart attack or stroke, and are taking it for primary prevention.

"The use of aspirin is still a very contentious issue among medical experts," said Craig Williams, a pharmacotherapy specialist with the College of Pharmacy at Oregon State University, and lead author of the new report.

"There's no doubt that aspirin use can have value for people who have experienced a first heart attack, stroke or angina," said Williams, a professor in the Oregon State University/Oregon Health & Science University College of Pharmacy. "The data to support that is very strong. The support of its use in primary prevention is more of a mixed bag.

"But this survey clearly shows that more and more people who have not experienced those events and are not technically considered at high risk by the FDA are also deciding to use aspirin, usually in consultation with their doctors."

Aside from cardiovascular events, some studies have suggested a role for aspirin in preventing cancer, Williams said, especially colon cancer. That has further increased interest in its use, he said.

While the FDA takes a more cautious stance, Williams said, some other professional organizations, such as the U.S. Preventative Services Task Force, says aspirin use may be appropriate for primary prevention in people with serious risk factors for cardiovascular disease, such as high blood pressure, high cholesterol, smoking or diabetes. Objective criteria for aspirin use in those patients are based on the number of the risk factors, the age and gender of the patient.

Surveys such as this are needed to help determine how people are managing their own health, Williams said, since aspirin is an over-the-counter medication and its use cannot be determined solely by medical records. And the findings suggest that tens of millions of Americans have reviewed the issues involved, often discussed it with their doctors, say they know what they are doing - and decided to use aspirin.

Among the findings of the report:

Several markers of healthy lifestyle choices were also associated with aspirin use.

The strongest predictor of regular aspirin use was a patient having discussed aspirin therapy with a health care provider.

About 35 percent of people who don't objectively have risk factors that might merit aspirin therapy still use it.

About 20 percent of people who have already had a heart attack or stroke, and should be on aspirin therapy, do not use it.

A majority of both current and previous aspirin users rated themselves as being somewhat or very knowledgeable about it.

Among aspirin users, the reasons cited for its use by respondents was for heart attack prevention, 84 percent; stroke prevention, 66 percent; cancer prevention, 18 percent; and prevention of Alzheimer's disease, 11 percent.

Significant predictors of aspirin use included people who were physically active, ate healthy foods, had achieved a healthy weight, managed their stress, tried to quit smoking, and/or had undergone health screenings.

This study was sponsored by the Partnership for Prevention and the Council on Aspirin for Health and Prevention. This council receives financial support from Bayer HealthCare, which has no influence over its programs or activities, and played no role in the decision to conduct this research or publish the results.

Collaborators with Oregon State University on the research were from Harvard/Brigham and Women's Hospital; the Partnership for Prevention; The Ohio State University; the University of North Carolina; and Stanford University.

A sniff of happiness: Chemicals in sweat may convey positive emotion

Humans may be able to communicate positive emotions like happiness through the smell of our sweat

Humans may be able to communicate positive emotions like happiness through the smell of our sweat, according to new research published in Psychological Science, a journal of the Association for Psychological Science.

The research indicates that we produce chemical compounds, or chemosignals, when we experience happiness that are detectable by others who smell our sweat.

While previous research has shown that negative emotions related to fear and disgust are communicated via detectable regularities in the chemical composition of sweat, few studies have examined whether the same communicative function holds for positive emotions.

"Our study shows that being exposed to sweat produced under happiness induces a simulacrum of happiness in receivers, and induces a contagion of the emotional state," explains psychological scientist Gün Semin of Utrecht University in the Netherlands, senior researcher on the study. "This suggests that somebody who is happy will infuse others in their vicinity with happiness. In a way, happiness sweat is somewhat like smiling - it is infectious."

To determine whether this emotional chemosignaling extends to positive emotions, Semin and colleagues examined whether sweat taken from people in a happy state would influence the behavior, perception, and emotional state of people exposed to the sweat.

The researchers recruited 12 Caucasian males to provide the sweat samples for the study. The participants did not smoke or take any medications, and had no diagnosed psychological disorders. They were prohibited from engaging in alcohol use, sexual activity, consumption of smelly food, or excessive exercise during the study.

The sweat donors came to the lab, rinsed and dried their armpits, and had absorbent pads attached to each armpit. They donned a prewashed T-shirt and sat down to complete the study tasks

They watched a video clip intended to induce a particular emotional state (fear, happiness, neutral) and they also completed a measure of implicit emotion, in which they were asked to view Chinese symbols and rate how pleasant or unpleasant each one was. The sweat pads were then removed and stored in vials.

For the second part of the study, the researchers recruited 36 Caucasian females, with no psychological disorder, respiratory disease, or other illness.

The researchers note that only females were included in this part of the study as women generally have both a better sense of smell and a greater sensitivity to emotional signals than men do.

The study was double-blind, such that neither the researcher nor the participant knew which sweat sample the participant would be exposed to at the time of the experiment.

The women were seated in a chair and placed their chins on a chin rest. The vial containing the sweat sample was placed in a holder attached to the chin rest and was opened immediately prior to the target task. The women were exposed to a sweat sample of each type (fear, happiness, neutral), with a 5-minute break in between samples.

Initial data analyses confirmed that the videos did influence the emotional states of the male participants - men who watched the fear video showed predominantly negative emotion afterward and men who watched the happiness video showed predominantly positive emotion. But were these emotions conveyed to the female participants? Some behavioral results suggest the answer is 'yes.'

Facial expression data revealed that women who were exposed to "fear sweat" showed greater activity in the medial frontalis muscle, a common feature of fear expressions. And women who were exposed to "happy sweat" showed more facial muscle activity indicative of a Duchenne smile, a common component of happiness expressions. There was no observable association, however, between the women's facial responses and their explicit ratings of how pleasant and intense the sweat was.

These findings, the researchers say, suggest a "behavioral synchronization" between the sender (the sweat donor) and receiver (the sweat smeller).

Additional data indicated that women exposed to happy sweat showed a more global focus in perceptual processing tasks, in line with previous research showing that participants induced to experience positive mood tended to show more global processing styles. But the sweat samples did not seem to impact the women's ratings on the Chinese symbols task, suggesting that the sweat-based chemosignals did not bias their implicit emotional states.

These findings, while preliminary, suggest that we communicate our positive and negative emotional states via distinct chemosignals, such that the receiver produces a simulacrum of the sender's emotional state.

The researchers note that the fact that some measures indicated emotional contagion, while others did not, may highlight the difference between measures of emotion that draw on language versus those that don't.

The findings have broad relevance - emotion and sweat are two core features of the human experience, after all. But the fact that happiness may be communicated chemically could be of particular interest to the "odor industry," says Semin, due to its potential commercial applications.

"This is another step in our general model on the communicative function of human sweat, and we are continuing to refine it to understand the neurological effects that human sweat has on recipients of these chemical compounds," Semin concludes.

Study co-authors include Jasper H.B. de Groot of Utrecht University; Monique A.M. Smeets of Utrecht University and Unilever Research and Development; and Matt J. Rowson, Patricia Bulsin, Cor G. Blonk, and Joy E. Wilkinson of Unilever Research and Development.

The research was supported by Unilever Research & Development (AGR 01049/OIV120260).

For a copy of the article "A Sniff of Happiness" and access to other Psychological Science research findings, please contact Anna Mikulak at 202-293-9300 or

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