Wednesday, April 16, 2014

Lithium-sulfur batteries last longer with nanomaterial-packed cathode


Electric vehicles could travel farther and more renewable energy could be stored with lithium-sulfur batteries that use a unique powdery nanomaterial.
Pacific Northwest National Laboratory developed
a nickel-based metal organic framework, shown here
in an illustration, to hold onto polysulfide molecules
in the cathodes of lithium-sulfur batteries and extend
the batteries' lifespans. The colored spheres in this i
mage represent the 3D material's tiny pores into with
the polysulfides become trapped.
Credit: Pacific Northwest National Laboratory
Researchers added the powder, a kind of nanomaterial called a metal organic framework, to the battery's cathode to capture problematic polysulfides that usually cause lithium-sulfur batteries to fail after a few charges. A paper describing the material and its performance was published online April 4 in the American Chemical Society journal Nano Letters.

"Lithium-sulfur batteries have the potential to power tomorrow's electric vehicles, but they need to last longer after each charge and be able to be repeatedly recharged," said materials chemist Jie Xiao of the Department of Energy's Pacific Northwest National Laboratory. "Our metal organic framework may offer a new way to make that happen."

Today's electric vehicles are typically powered by lithium-ion batteries. But the chemistry of lithium-ion batteries limits how much energy they can store. As a result, electric vehicle drivers are often anxious about how far they can go before needing to charge. One promising solution is the lithium-sulfur battery, which can hold as much as four times more energy per mass than lithium-ion batteries. This would enable electric vehicles to drive farther on a single charge, as well as help store more renewable energy. The down side of lithium-sulfur batteries, however, is they have a much shorter lifespan because they can't currently be charged as many times as lithium-ion batteries.

Energy Storage 101

The reason can be found in how batteries work. Most batteries have two electrodes: one is positively charged and called a cathode, while the second is negative and called an anode. Electricity is generated when electrons flow through a wire that connects the two. To control the electrons, positively charged atoms shuffle from one electrode to the other through another path: the electrolyte solution in which the electrodes sit.

The lithium-sulfur battery's main obstacles are unwanted side reactions that cut the battery's life short. The undesirable action starts on the battery's sulfur-containing cathode, which slowly disintegrates and forms molecules called polysulfides that dissolve into the liquid electrolyte. Some of the sulfur—an essential part of the battery's chemical reactions—never returns to the cathode. As a result, the cathode has less material to keep the reactions going and the battery quickly dies.

New materials for better batteries

Researchers worldwide are trying to improve materials for each battery component to increase the lifespan and mainstream use of lithium-sulfur batteries. For this research, Xiao and her colleagues honed in on the cathode to stop polysulfides from moving through the electrolyte.

Many materials with tiny holes have been examined to physically trap polysulfides inside the cathode. Metal organic frameworks are porous, but the added strength of PNNL's material is its ability to strongly attract the polysulfide molecules.

The framework's positively charged nickel center tightly binds the polysulfide molecules to the cathodes. The result is a coordinate covalent bond that, when combined with the framework's porous structure, causes the polysulfides to stay put.

"The MOF's highly porous structure is a plus that further holds the polysulfide tight and makes it stay within the cathode," said PNNL electrochemist Jianming Zheng.

Nanomaterial is key

Metal organic frameworks—also called MOFs—are crystal-like compounds made of metal clusters connected to organic molecules, or linkers. Together, the clusters and linkers assemble into porous 3-D structures. MOFs can contain a number of different elements. PNNL researchers chose the transition metal nickel as the central element for this particular MOF because of its strong ability to interact with sulfur.

During lab tests, a lithium-sulfur battery with PNNL's MOF cathode maintained 89 percent of its initial power capacity after 100 charge-and discharge cycles. Having shown the effectiveness of their MOF cathode, PNNL researchers now plan to further improve the cathode's mixture of materials so it can hold more energy. The team also needs to develop a larger prototype and test it for longer periods of time to evaluate the cathode's performance for real-world, large-scale applications.

PNNL is also using MOFs in energy-efficient adsorption chillers and to develop new catalysts to speed up chemical reactions.

"MOFs are probably best known for capturing gases such as carbon dioxide," Xiao said. "This study opens up lithium-sulfur batteries as a new and promising field for the nanomaterial."

This research was funded by the Department of Energy's Office of Energy Efficiency and Renewable Energy. Researchers analyzed chemical interactions on the MOF cathode with instruments at EMSL, DOE's Environmental Molecular Sciences Laboratory at PNNL.

In January, a Nature Communications paper by Xiao and some of her PNNL colleagues described another possible solution for lithium-sulfur batteries: developing a hybrid anode that uses a graphite shield to block polysulfides.

Source: http://phys.org/news/2014-04-lithium-sulfur-batteries-longer-nanomaterial-packed-cathode.html


Monday, March 31, 2014

Aging Successfully Reversed in Mice; Human Trials to Begin Next


Scientists have successfully reversed the aging process in mice according to a new study just released. Human trials are to begin next, possibly before the year is over. The study was published in the peer reviewed science journal Cell after researchers from both the U.S and Australia made the breakthrough discovery. Lead researcher David Sinclair of the University of New South Wales says he is hopeful that the outcome can be reproduced in human trials. A successful result in people would mean not just a slowing down of aging but a measurable reversal.

Scientists have successfully reversed the aging process in mice according to a new study just released. Human trials are to begin next, possibly before the year is over.

The study showed that after administering a certain compound to the mice, muscle degeneration and diseases caused by aging were reversed. Sinclair says the study results exceeded his expectations, explaining:

I’ve been studying aging at the molecular level now for nearly 20 years and I didn’t think I’d see a day when ageing could be reversed. I thought we’d be lucky to slow it down a little bit. The mice had more energy, their muscles were as though they’d be exercising and it was able to mimic the benefits of diet and exercise just within a week. We think that should be able to keep people healthier for longer and keep them from getting diseases of ageing.
The compound the mice ate resulted in their muscles becoming very toned, as if they’d been exercising. Inflammation, a key factor in many disease processes, was drastically reduced. Insulin resistance also declined dramatically and the mice had much more energy overall. Researchers say that what happened to the mice could be compared to a 60 year old person suddenly having the muscle tone and energy of someone in his or her 20s.

What’s more, say the researchers, these stunning results were realized within just one week’s time. The compound raises the level of a naturally occurring substance in the human body called nicotinamide adenine dinucleotide. This substance decreases as people age, although those who follow a healthy diet and get plenty of exercise do not suffer the same level of reduction in the substance as do people who do not exercise. This may explain why people who remain fit into their senior years often enjoy better health than others.

Scientists who participated in the study say that poor communication between mitochondria and the cell nucleus is to blame for the aging process. The compound the researchers have developed cause the cells to be able to “talk” to each other again. They compared the relationship between the nucleus and the mitochondria to a married couple; by the time the couple has been married for 20 years, “communication breaks down” and they don’t talk to each other as much. Just like a marriage, this relationship and communication within it can be repaired, say the researchers.

Aging has successfully been reversed in mice, but Sinclair says he needs to raise more money before he can commit to a date when trials may begin in humans. The results of this initial study in mice are very promising and may pave the way for similar results in humans.

Sources: ABC News , Science Direct , Huffington Post


Friday, December 13, 2013

Instagram Direct messaging arrives to challenge Snapchat and Whatsapp


HIPSTER PHOTO SHARING SERVICE Instagram announced a messaging service called Instagram Direct on Thursday, as it looks to challenge Snapchat and Whatsapp.

Rumours surfaced at the end of November claiming that Instagram was plotting a messaging service to rival send-and-delete photo service Snapchat, and the firm put an end to the speculation on Thursday by announcing Instagram Direct.

The service does what it says on the tin, allowing Instagram users to send images and videos in direct messages to one another.

Instagram Direct lets users of the service send messages to up to 15 friends at once, much like Whatsapp, and allows groups to talk in real-time chats. Only people you follow can send you images and videos, Instagram said on Thursday, so you shouldn't have to worry about your inbox filling up with spam.

There's now an inbox logo on the top right hand corner of the app to access Instagram Direct, replacing the previous refresh button, which has been replaced with a pull to refresh function.

Instagram said, "There are moments in our lives that we want to share, but that will be the most relevant only to a smaller group of people - an inside joke between friends captured on the go, a special family moment or even just one more photo of your new puppy. Instagram Direct helps you share these moments.

"From how you capture photos and videos to the way you start conversations through likes and comments, we built Instagram Direct to feel natural to the Instagram experience you already know." Instagram Direct arrives in an update to the existing Instagram app, which is available to download for free from the iTunes App Store and Google Play store. The feature is not available yet for Windows Phone devices.


Thursday, December 12, 2013

Bangkok designers draw attention for air-purifying bike idea


Some observers are calling it "the photosynthesis bike." The bike of interest is only a concept, not even a prototype yet, from designers in Bangkok. Nonetheless, in concept alone, it has captured a lot if imaginations, press coverage, and even picked up an award in the 2013 Red Dot competition for design concept. Dubbed "Air Purifier Bike," from Bangkok-based Lightfog Creative and Design, the bicycle presents a next-level functionality to bicycles as environmentally sound vehicles—to the point where the rider not only uses a clean mode of transport but also helps to purify the air along with the ride. (The Red Dot Award for design concept is part of a professional design competition for design concepts and prototypes worldwide.)
Silawat Virakul, Torsakul Kosaikul, and Suvaroj Poosrivongvanid are the designers behind the award-winning idea. They said their Air-Purifier Bike incorporates an air filter that screens dust and pollutants from the air, a photosynthesis system (including a water tank) that produces oxygen, an electric motor, and a battery. "While it is being ridden, air passes through the filter at the front of the bike, where it is cleaned before being released toward cyclist. The bike frame houses the photosynthesis system. When the bike is parked, the air-purifying functions can continue under battery power."

According to a report on the bicycle and the designers behind it on the Fast Company Co.Exist site, the designers presently have mock-ups, but they have not yet built a prototype; they plan to build one soon.

"We want to design products which can reduce the air pollution in the city. So we decided to design a bike because we thought that bicycles are environmentally friendly vehicles for transportation," said creative director Silawat Virakul in an email to Co.Exist.


"Riding a bicycle can reduce traffic jam[s] in a city," said Virakul. "Moreover, we wanted to add more value to a bicycle by adding its ability to reduce the pollution."


If they were to advance their concept, they would be responding to many urban dwellers who are growing increasingly aware that bicycles ease pollution and are taking to bicycles for short-distance transportation. Earlier this year, Lucintel, a consulting and market research firm, analyzed the global bicycle industry in "Global Bicycle Industry 2013-2018: Trends, Profit, and Forecast Analysis." They noted that government initiatives to promote cycling to reduce carbon emissions and noise pollution are a strong growth driver. In addition, bicycles' energy efficiency, coupled with cycling as a fitness activity, will help propel demand during the forecast period.


Tuesday, October 15, 2013

New Device Harnesses Sun and Sewage to Produce Hydrogen Fuel


A novel device that uses only sunlight and wastewater to produce hydrogen gas could provide a sustainable energy source while improving the efficiency of wastewater treatment.

The new hybrid solar-microbial device is self-driven and self-sustained, because the combined energy from the organic matter (harvested by the MFC) and sunlight (captured by the PEC) is sufficient to drive electrolysis of water.
The new hybrid solar-microbial device is self-driven 
and self-sustained, because the combined energy from 
the organic matter (harvested by the MFC) and sunlight 
(captured by the PEC) is sufficient to drive electrolysis 
of water. (Credit: Image courtesy of University 
of California - Santa Cruz)
A research team led by Yat Li, associate professor of chemistry at the University of California, Santa Cruz, developed the solar-microbial device and reported their results in a paper published in the American Chemical Society journal ACS Nano. The hybrid device combines a microbial fuel cell (MFC) and a type of solar cell called a photoelectrochemical cell (PEC). In the MFC component, bacteria degrade organic matter in the wastewater, generating electricity in the process. The biologically generated electricity is delivered to the PEC component to assist the solar-powered splitting of water (electrolysis) that generates hydrogen and oxygen.

Either a PEC or MFC device can be used alone to produce hydrogen gas. Both, however, require a small additional voltage (an "external bias") to overcome the thermodynamic energy barrier for proton reduction into hydrogen gas. The need to incorporate an additional electric power element adds significantly to the cost and complication of these types of energy conversion devices, especially at large scales. In comparison, Li's hybrid solar-microbial device is self-driven and self-sustained, because the combined energy from the organic matter (harvested by the MFC) and sunlight (captured by the PEC) is sufficient to drive electrolysis of water.

In effect, the MFC component can be regarded as a self-sustained "bio-battery" that provides extra voltage and energy to the PEC for hydrogen gas generation. "The only energy sources are wastewater and sunlight," Li said. "The successful demonstration of such a self-biased, sustainable microbial device for hydrogen generation could provide a new solution that can simultaneously address the need for wastewater treatment and the increasing demand for clean energy."

Microbial fuel cells rely on unusual bacteria, known as electrogenic bacteria, that are able to generate electricity by transferring metabolically-generated electrons across their cell membranes to an external electrode. Li's group collaborated with researchers at Lawrence Livermore National Laboratory (LLNL) who have been studying electrogenic bacteria and working to enhance MFC performance. Initial "proof-of-concept" tests of the solar-microbial (PEC-MFC) device used a well-studied strain of electrogenic bacteria grown in the lab on artificial growth medium. Subsequent tests used untreated municipal wastewater from the Livermore Water Reclamation Plant. The wastewater contained both rich organic nutrients and a diverse mix of microbes that feed on those nutrients, including naturally occurring strains of electrogenic bacteria.

When fed with wastewater and illuminated in a solar simulator, the PEC-MFC device showed continuous production of hydrogen gas at an average rate of 0.05 m3/day, according to LLNL researcher and coauthor Fang Qian. At the same time, the turbid black wastewater became clearer. The soluble chemical oxygen demand--a measure of the amount of organic compounds in water, widely used as a water quality test--declined by 67 percent over 48 hours.

The researchers also noted that hydrogen generation declined over time as the bacteria used up the organic matter in the wastewater. Replenishment of the wastewater in each feeding cycle led to complete restoration of electric current generation and hydrogen gas production.

Qian said the researchers are optimistic about the commercial potential for their invention. Currently they are planning to scale up the small laboratory device to make a larger 40-liter prototype continuously fed with municipal wastewater. If results from the 40-liter prototype are promising, they will test the device on site at the wastewater treatment plant.

"The MFC will be integrated with the existing pipelines of the plant for continuous wastewater feeding, and the PEC will be set up outdoors to receive natural solar illumination," Qian said.

"Fortunately, the Golden State is blessed with abundant sunlight that can be used for the field test," Li added.

Qian and Hanyu Wang, a graduate student in Li's lab at UC Santa Cruz, are co-first authors of the ACS Nano paper. The other coauthors include UCSC graduate student Gongming Wang; LLNL researcher Yongqin Jiao; and Zhen He of Virginia Polytechnic Institute & State University. This research was supported by the National Science Foundation and Department of Energy.
 

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Tuesday, August 27, 2013

How the Brain Remembers Pleasure: Implications for Addiction


Key details of the way nerve cells in the brain remember pleasure are revealed in a study by University of Alabama at Birmingham (UAB) researchers published today in the journal Nature Neuroscience. The molecular events that form such "reward memories" appear to differ from those created by drug addiction, despite the popular theory that addiction hijacks normal reward pathways.

Brain activity (artist's rendering). 
(Credit: © James Steidl / Fotolia)
Brain circuits have evolved to encourage behaviors proven to help our species survive by attaching pleasure to them. Eating rich food tastes good because it delivers energy and sex is desirable because it creates offspring. The same systems also connect in our mind's environmental cues with actual pleasures to form reward memories.

This study in rats supports the idea that the mammalian brain features several memory types, each using different circuits, with memories accessed and integrated as needed. Ancient memory types include those that remind us what to fear, what to seek out (reward), how to move (motor memory) and navigate (place memory). More recent developments enable us to remember the year Columbus sailed and our wedding day.

"We believe reward memory may serve as a good model for understanding the molecular mechanisms behind many types of learning and memory," said David Sweatt, Ph.D., chair of the UAB Department of Neurobiology, director of the Evelyn F. McKnight Brain Institute at UAB and corresponding author for the study. "Our results provide a leap in the field's understanding of reward-learning mechanisms and promise to guide future attempts to solve related problems such as addiction and criminal behavior."

The study is the first to illustrate that reward memories are created by chemical changes that influence known memory-related genes in nerve cells within a brain region called the ventral tegmental area, or VTA. Experiments that blocked those chemical changes -- a mix of DNA methylation and demethylation -- in the VTA prevented rats from forming new reward memories.

Methylation is the attachment of a methyl group (one carbon and three hydrogens) to a DNA chain at certain spots (cytosine bases). When methylation occurs near a gene or inside a gene sequence, it generally is thought to turn the gene off and its removal is thought to turn the gene on. This back-and-forth change affects gene expression without changing the code we inherit from our parents. Operating outside the genetic machinery proper, epigenetic changes enable each cell type to do its unique job and to react to its environment.

Furthermore, a stem cell in the womb that becomes bone or liver cells must "remember" its specialized nature and pass that identity to its descendants as they divide and multiply to form organs. This process requires genetic memory, which largely is driven by methylation. Note, most nerve cells do not divide and multiply as do other cells. They can't, according to one theory, because they put their epigenetic mechanisms to work making actual memories.

Natural pleasure versus addiction

The brain's pleasure center is known to proceed through nerve cells that signal using the neurochemical dopamine and generally is located in the VTA. Dopaminergic neurons exhibit a "remarkable capacity" to pass on pleasure signals. Unfortunately, the evolutionary processes that attached pleasure to advantageous behaviors also accidentally reinforced bad ones.

Addiction to all four major classes of abused drugs -- psychostimulants, opiates, ethanol and nicotine -- has been linked to increased dopamine transmission in the same parts of the brain associated with normal reward processing. Cues that predict both normal reward and effects of cocaine or alcohol also make dopamine nerve cells fire as do the experiences they recall. That had led to idea that drug addiction must take over normal reward-memory nerve pathways.

Along those lines, past research has argued that dopamine-producing neurons in the VTA -- and in a region that receives downstream dopamine signals from the VTA called the nucleus accumbens (NAC) -- both were involved in natural reward and drug-addiction-based memory formation. While that may true to some extent, this study revealed that blocking methylation in the VTA with a drug stopped the ability of rats to attach rewarding experiences to remembered cues but doing so in the NAC did not.

"We observed an important distinction, not in circuitry, but instead in the epigenetic regulation of that circuitry between natural reward responses and those that occur downstream with drugs of abuse or psychiatric illness," said Jeremy Day, Ph.D., a post-doctoral scholar in Sweatt's lab and first author for this study. "Although drug experiences may co-opt normal reward mechanisms to some extent, our results suggest they also may engage entirely separate epigenetic mechanisms that contribute only to addiction and that may explain its strength."

To investigate the molecular and epigenetic changes in the VTA, researchers took their cue from 19th century Russian physiologist Ivan Pavlov, who was the first to study the phenomenon of conditioning. By ringing a bell each day before giving his dogs food, Pavlov soon found that the dogs would salivate at the sound of the bell.

In this study, rats were trained to associate a sound tone with the availability of sugar pellets in their feed ports. This same animal model has been used to make most discoveries about how human dopamine neurons work since the 1990s, and most approved drugs that affect the dopamine system (e.g. L-Dopa for Parkinson's) were tested in it before being cleared for human trials.

To separate the effects of memory-related brain changes from those arising from the pleasure of the eating itself, the rats were separated into three groups. Rats in the "CS+" rats got sugar pellets each time they heard a sound cue. The "CS-" group heard the sound the same number of times and received as many sugar pellets -- but never together. A third tone-only group heard the sounds but never received sugar rewards.

Rats that always received sugar with the sound cue were found to poke their feed ports with their noses at least twice as often during this cue as control rats after three, 25-sound-cue sessions. Nose pokes are an established measure of the degree to which a rat has come to associate a cue with the memory of a tasty treat.

The team found that those CS+ rats (sugar paired with sound) that were better at forming reward memories had significantly higher expression of the genes Egr1 and Fos than control rats These genes are known to regulate memory in other brain regions by fine-tuning the signaling capacity of the connections between nerve cells. In a series of experiments, the team next revealed the methylation and demethylation pattern that drove the changes in gene expression seen as memories formed.

The study demonstrated that reward-related experiences caused both types of DNA methylation known to regulate gene expression.

One type involves attaching methyl groups to pieces of DNA called promoters, which reside immediately upstream of individual gene sequences (between genes), that tell the machinery that follows genetic instructions to "start reading here." The attachment of a methyl group to a promoter generally interferes with this and silences a nearby gene. However, ancient organisms such as plants and insects have less methylation between their genes, and more of it within the coding regions of the genes themselves (within gene bodies). Such gene-body methylation has been shown to encourage rather than silence gene expression.

Specifically, the team reported that two sites in the promoter for Egr1 gene were demethylated during reward experiences and, to a greater degree, in rats that associated the sugar with the sound cue. Conversely, spots within the gene body of both Egr1 and Fos underwent methylation as reward memories formed.

"When designing therapeutic treatments for psychiatric illness, addictions or memory disorders, you must profoundly understand the function of the biological systems you're working with," Day said. "Our field has learned from experience that attempts to treat addiction with something that globally impairs normal reward perception or reward memories do not succeed. Our study suggests the possibility that future treatments could dial down drug addiction or mental illness without affecting normal rewards."

Along with Sweatt and Day, authors for the study were Daniel Childs, Mikael Guzman-Karlsson, Mercy Kibe, Jerome Moulden, Esther Song and Absar Tahir within the Department of Neurobiology and the Evelyn F. McKnight Brain Institute at University of Alabama at Birmingham. This work is supported by the National Institute on Drug Abuse (DA029419), the National Institute on Mental Health (MH091122 and MH057014), and the Evelyn F. McKnight Brain Research Foundation.


Friday, August 23, 2013

Researchers use mobile phones to measure happiness


Researchers at Princeton University are developing ways to use mobile phones to explore how one's environment influences one's sense of well-being.

Locations of study subjects on world map. Credit: Demography
In a study involving volunteers who agreed to provide information about their feelings and locations, the researchers found that cell phones can efficiently capture information that is otherwise difficult to record, given today's on-the-go lifestyle. This is important, according to the researchers, because feelings recorded "in the moment" are likely to be more accurate than feelings jotted down after the fact.

To conduct the study, the team created an application for the Android operating system that documented each person's location and periodically sent the question, "How happy are you?"

The investigators invited people to download the app, and over a three-week period, collected information from 270 volunteers in 13 countries who were asked to rate their happiness on a scale of 0 to 5. From the information collected, the researchers created and fine-tuned methods that could lead to a better understanding of how our environments influence emotional well-being. The study was published in the June issue of Demography.

The mobile phone method could help overcome some of the limitations that come with surveys conducted at people's homes, according to the researchers. Census measurements tie people to specific areas—the census tracts in which they live—that are usually not the only areas that people actually frequent.

"People spend a significant amount of time outside their census tracks," said John Palmer, a graduate student in the Woodrow Wilson School of Public and International Affairs and the paper's lead author. "If we want to get more precise findings of contextual measurements we need to use techniques like this."

Palmer teamed up with Thomas Espenshade, professor of sociology emeritus, and Frederic Bartumeus, a specialist in movement ecology at the Center for Advanced Studies of Blanes in Spain, along with Princeton's Chang Chung, a statistical programmer and data archivist in the Office of Population Research; Necati Ozgencil, a former Professional Specialist at Princeton; and Kathleen Li, who earned her undergraduate degree in computer science from Princeton in 2010, to design the free, open source application for the Android platform that would record participants' locations at various intervals based on either GPS satellites or cellular tower signals.

Though many of the volunteers lived in the United States, some were in Australia, Canada, China, France, Germany, Israel, Japan, Norway, South Korea, Spain, Sweden and the United Kingdom.

Palmer noted that the team's focus at this stage was not on generalizable conclusions about the link between environment and happiness, but rather on learning more about the mobile phone's capabilities for data collection. "I'd be hesitant to try to extend our substantive findings beyond those people who volunteered." he said.

However, the team did obtain some preliminary results regarding happiness: for example, male subjects tended to describe themselves as less happy when they were further from their homes, whereas females did not demonstrate a particular trend with regards to emotions and distance.

"One of the limitations of the study is that it is not representative of all people," Palmer said. Participants had to have smartphones and be Internet users. It is also possible that people who were happy were more likely to respond to the survey. However, Palmer said, the study demonstrates the potential for mobile phone research to reach groups of people that may be less accessible by paper surveys or interviews.

Palmer's doctoral dissertation will expand on this research, and his adviser Marta Tienda, the Maurice P. During Professor in Demographic Studies, said she was excited to see how it will impact the academic community. "His applied research promises to redefine how social scientists understand intergroup relations on many levels," she said.


This study involved contributions from the Center for Information Technology Policy at Princeton University, with institutional support from the National Institutes of Health Training Grant T32HD07163 and Infrastructure Grant R24HD047879.


Saturday, August 10, 2013

Report:A Semi-Floating Gate Transistor for Low-Voltage Ultrafast Memory and Sensing Operation


Researchers at Fudan University in China have discovered a way to speed up traditional computer transistors by embedding tunneling field-effect transistors (TFETs) in them. In their paper published in the journal Science, the team describes how embedding TFETs in such transistors allows for them to be run with less power, which in turn causes them to run faster.

Researchers at Fudan University in China have discovered a way to speed up traditional computer transistors by embedding tunneling field-effect transistors (TFETs) in them. In their paper published in the journal Science, the team describes how embedding TFETs in such transistors allows for them to be run with less power, which in turn causes them to run faster.
Schematic view of an SFG memory cell. A pn junction diode between the FG and D makes the FG semi-floating. The device’s symbolic representation is also shown. Credit: Science 9 August 2013: Vol. 341 no. 6146 pp. 640-643 DOI: 10.1126/science.1240961

Most modern computers are run with either metal-oxide-semiconductor field-effect transistors (MOSFETs) or a variation of them called floating-gate (FG) MOSFETs. Such transistors are now reaching their physical limit as far as how thin they can be—just a few atoms thick. For that reason, researchers have been looking for other ways to get more bang for their buck. In this new effort, the researchers turned to TFETs, which use quantum tunneling to move electrons through very thin material.

TFETs have traditionally been used in very low power devices. In this endeavor, they researchers created a TFET that could be used to control the electrodes that monitor the flow of electricity into a MOSFET—in this case, the floating-gate variety (it has an additional electrode gate that allows a charge to be retained). The idea is that if the gate could be made to open and close faster, the transistor as a whole would operate faster. Current chips require a build-up of charge before the gate can be opened or closed—which requires time. TFETs, because they require less power, don't take as long to do their work, thus embedding one in a floating gate-MOSFET would alleviate the necessity of power buildup prior to gate changes, allowing for quicker opening and closing. That's exactly what the team in China has done. Testing thus far has shown MOSFETs with embedded TFETs have improved transistor speeds as well as reduced power requirements.

The team reports that because of the way their TFETs are constructed, embedding them in current model MOSFETs should not require reconfiguration or the use of any new materials. This means that the new TFET technology could be put into use almost immediately, bumping up the speed of computers and hand held devices while lessening the amount of energy used, resulting in longer battery life.

More information: A Semi-Floating Gate Transistor for Low-Voltage Ultrafast Memory and Sensing Operation, Science 9 August 2013: Vol. 341 no. 6146 pp. 640-643 DOI: 10.1126/science.1240961

ABSTRACT

As the semiconductor devices of integrated circuits approach the physical limitations of scaling, alternative transistor and memory designs are needed to achieve improvements in speed, density, and power consumption. We report on a transistor that uses an embedded tunneling field-effect transistor for charging and discharging the semi-floating gate. This transistor operates at low voltages (?2.0 volts), with a large threshold voltage window of 3.1 volts, and can achieve ultra–high-speed writing operations (on time scales of ~1 nanosecond). A linear dependence of drain current on light intensity was observed when the transistor was exposed to light, so possible applications include image sensing with high density and performance.


Friday, July 26, 2013

Bad Night's Sleep? The Moon Could Be to Blame


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Many people complain about poor sleep around the full moon, and now a report appearing in Current Biology, a Cell Press publication, on July 25 offers some of the first convincing scientific evidence to suggest that this really is true. The findings add to evidence that humans -- despite the comforts of our civilized world -- still respond to the geophysical rhythms of the moon, driven by a circalunar clock.

Many people complain about poor sleep around the full moon, and now a report appearing in Current Biology, a Cell Press publication, on July 25 offers some of the first convincing scientific evidence to suggest that this really is true. The findings add to evidence that humans -- despite the comforts of our civilized world -- still respond to the geophysical rhythms of the moon, driven by a circalunar clock.
Many people complain about poor sleep around the full moon, and now a report appearing in Current Biology, a Cell Press publication, on July 25 offers some of the first convincing scientific evidence to suggest that this really is true. The findings add to evidence that humans -- despite the comforts of our civilized world -- still respond to the geophysical rhythms of the moon, driven by a circalunar clock. (Credit: Current Biology, Cajochen et al.)

"The lunar cycle seems to influence human sleep, even when one does not 'see' the moon and is not aware of the actual moon phase," says Christian Cajochen of the Psychiatric Hospital of the University of Basel.

In the new study, the researchers studied 33 volunteers in two age groups in the lab while they slept. Their brain patterns were monitored while sleeping, along with eye movements and hormone secretions.

The data show that around the full moon, brain activity related to deep sleep dropped by 30 percent. People also took five minutes longer to fall asleep, and they slept for twenty minutes less time overall. Study participants felt as though their sleep was poorer when the moon was full, and they showed diminished levels of melatonin, a hormone known to regulate sleep and wake cycles.

"This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues," the researchers say.

Cajochen adds that this circalunar rhythm might be a relic from a past in which the moon could have synchronized human behaviors for reproductive or other purposes, much as it does in other animals. Today, the moon's hold over us is usually masked by the influence of electrical lighting and other aspects of modern life.

The researchers say it would be interesting to look more deeply into the anatomical location of the circalunar clock and its molecular and neuronal underpinnings. And, they say, it could turn out that the moon has power over other aspects of our behavior as well, such as our cognitive performance and our moods.


Tuesday, July 16, 2013

Computer as Smart as a 4-Year-Old? Researchers IQ Test New Artificial Intelligence System


Artificial and natural knowledge researchers at the University of Illinois at Chicago have IQ-tested one of the best available artificial intelligence systems to see how intelligent it really is.

Artificial and natural knowledge researchers at the University of Illinois at Chicago have IQ-tested one of the best available artificial intelligence systems to see how intelligent it really is.
Artificial and natural knowledge researchers IQ-tested 
one of the best available artificial intelligence systems 
and learned that it's about as smart as the average 
4-year-old. (Credit: © Spofi / Fotolia)
Turns out it's about as smart as the average 4-year-old, they will report July 17 at the U.S. Artificial Intelligence Conference in Bellevue, Wash.

The UIC team put ConceptNet 4, an artificial intelligence system developed at M.I.T., through the verbal portions of the Weschsler Preschool and Primary Scale of Intelligence Test, a standard IQ assessment for young children.

They found ConceptNet 4 has the average IQ of a young child. But unlike most children, the machine's scores were very uneven across different portions of the test.

"If a child had scores that varied this much, it might be a symptom that something was wrong," said Robert Sloan, professor and head of computer science at UIC, and lead author on the study.

Sloan said ConceptNet 4 did very well on a test of vocabulary and on a test of its ability to recognize similarities.

"But ConceptNet 4 did dramatically worse than average on comprehension­the 'why' questions," he said.

One of the hardest problems in building an artificial intelligence, Sloan said, is devising a computer program that can make sound and prudent judgment based on a simple perception of the situation or facts-the dictionary definition of commonsense.

Commonsense has eluded AI engineers because it requires both a very large collection of facts and what Sloan calls implicit facts-things so obvious that we don't know we know them. A computer may know the temperature at which water freezes, but we know that ice is cold.

"All of us know a huge number of things," said Sloan. "As babies, we crawled around and yanked on things and learned that things fall. We yanked on other things and learned that dogs and cats don't appreciate having their tails pulled." Life is a rich learning environment.

"We're still very far from programs with commonsense-AI that can answer comprehension questions with the skill of a child of 8," said Sloan. He and his colleagues hope the study will help to focus attention on the "hard spots" in AI research.

Study coauthors are UIC professors Stellan Ohlsson of psychology and Gyorgy Turan of mathematics, statistics and computer science; and UIC mathematical computer science undergraduate student Aaron Urasky.

The study was supported by award N00014-09-1-0125 from the Office of Naval Research and grant CCF-0916708 from the National Science Foundation.


Friday, July 5, 2013

For better batteries, just add water


A new type of lithium-ion battery that uses aqueous iodide ions in an aqueous cathode configuration provides twice the energy density of conventional lithium-ion batteries.

A new type of lithium-ion battery that uses aqueous iodide ions
in an aqueous cathode configuration provides twice the energy
density of conventional lithium-ion batteries.
Lithium-ion batteries are now found everywhere in devices such as cellular phones and laptop computers, where they perform well. In automotive applications, however, engineers face the challenge of squeezing enough lithium-ion batteries onto a vehicle to provide the desired power and range without introducing storage and weight issues. Hye Ryung Byon, Yu Zhao and Lina Wang from the RIKEN Byon Initiative Research Unit have now developed a lithium-iodine battery system with twice the energy density of conventional lithium-ion batteries.

Byon's team is involved in alternative energy research and, specifically, improving the performance of lithium-based battery technologies. In their research they turned to an 'aqueous' system in which the organic electrolyte in conventional lithium-ion cells is replaced with water. Such aqueous lithium battery technologies have gained attention among alternative energy researchers because of their greatly reduced fire risk and environmental hazard. Aqueous solutions also have other advantages, which include an inherently high ionic conductivity.

For their battery system, the researchers investigated an 'aqueous cathode' configuration (Fig. 1), which accelerates reduction and oxidation reactions to improve battery performance. Finding suitable reagents for the aqueous cathode, however, proved to be a tricky proposition. According to Byon, water solubility is the most important criterion for screening new materials, since this parameter determines the battery's energy density. Furthermore, the redox reaction has to take place in a restricted voltage range in order to avoid water electrolysis. An extensive search led the researchers to produce the first-ever lithium battery involving aqueous iodine—an element with high water solubility and a pair of ions, known as the triiodide/iodide redox couple, that readily undergo aqueous electrochemical reactions.

The team constructed a prototype aqueous cathode device and found the energy density to be nearly double that of a conventional lithium-ion battery, thanks to the high solubility of the triiodide/iodide ions. Their battery had high and near-ideal power storage capacities and could be successfully recharged hundreds of times, avoiding a problem that plagues other alternative high-energy-density lithium-ion batteries. Microscopy analysis revealed that the cathode collector remained untouched after 100 charge/discharge cycles with no observable corrosion or precipitate formation.

Byon and colleagues now plan to develop a three-dimensional, microstructured current collector that could enhance the diffusion-controlled triiodide/iodide process and accelerate charge and discharge. They are also seeking to raise energy densities even further by using a flowing-electrode configuration that stores aqueous 'fuel' in an external reservoir—a modification that should make this low-cost, heavy metal-free design more amenable to electric vehicle specifications.

More information: 1.Zhao, Y., Wang, L. & Byon, H. R. High-performance rechargeable lithium-iodine batteries using triiodide/iodide redox couples in an aqueous cathode. Nature Communications 4, 1896 (2013). dx.doi.org/10.1038/ncomms2907


Wednesday, July 3, 2013

Microsoft creates mood sensing software for smartphones


Microsoft Research Asia has been working on creating software called MoodScope that notes how a user uses his or her phone, and then uses that information to guess that user's mood. Initial testing of the device has shown it to be 66 percent accurate; when tailored to an individual user, the team reports that the accuracy rate jumped to 93 percent. The research team includes Nicholas Lane and Robert LiKamWa of Rice University, and Lin Zhong and Yunxin Liu from Microsoft Research Asia. They built a prototype and posted their test study results on Microsoft's website.
The circumplex mood model.
The circumplex mood model. Credit: Robert LiKamWa et al.

Most people realize that their smartphone has a lot of embedded technology in it that interacts with the world at large—GPS hardware, accelerometers, etc. all monitor activity and use that data to provide useful functions, such as automatically switching from landscape to portrait mode when a phone is rotated. In this new effort, the researchers sought to discover whether software that monitors phone activities could reveal the users' moods.

To find out, the team wrote code that monitored email, texting, app usage, phone calls, location information, and browsing history, then added algorithms to guess mood based on that data. Next, they enlisted the assistance of 32 volunteers to help them test the accuracy of their code. The volunteers were asked to use the system for two months while also completing mood assessments to provide data for comparison. With no training or tweaking, the software was found to provide answers of happy, tense, calm, upset, excited, stressed, or bored that matched the actual mood reported by the volunteers, on average 66 percent of the time. After optimizing the system for the individual habits of each of the volunteers, the rate increased to 93 percent.

The researchers suggest third party hooks could be added to the software to allow for automatically transmitting user moods to applications like Facebook. They also acknowledge that privacy concerns could arise if the software were to be delivered to the public, but suggest the benefits of such software would likely outweigh such concerns. They note that sites like Netflix or Spotify could use data from MoodScope to offer movies or other content based on specific users' moods.


video

The team presented their findings at MobiSys 2013 held in Taiwan last month.

 

More information: MoodScope Building a Mood Sensor from Smartphone Usage Patterns: research.microsoft.com/apps/pubs/default.aspx?id=194498
 

Research paper: www.ruf.rice.edu/~mobile/publications/likamwa2013mobisys2.pdf


Sunday, June 30, 2013

Imagination Can Change What We Hear and See


A study from Karolinska Institut in Sweden shows, that our imagination may affect how we experience the world more than we perhaps think. What we imagine hearing or seeing "in our head" can change our actual perception. The study, which is published in the scientific journal Current Biology, sheds new light on a classic question in psychology and neuroscience -- about how our brains combine information from the different senses.

Illusion of colliding objects.
Illusion of colliding objects. (Credit: Image courtesy of Karolinska Institutet)

"We often think about the things we imagine and the things we perceive as being clearly dissociable," says Christopher Berger, doctoral student at the Department of Neuroscience and lead author of the study. "However, what this study shows is that our imagination of a sound or a shape changes how we perceive the world around us in the same way actually hearing that sound or seeing that shape does. Specifically, we found that what we imagine hearing can change what we actually see, and what we imagine seeing can change what we actually hear."

The study consists of a series of experiments that make use of illusions in which sensory information from one sense changes or distorts one's perception of another sense. Ninety-six healthy volunteers participated in total.

In the first experiment, participants experienced the illusion that two passing objects collided rather than passed by one-another when they imagined a sound at the moment the two objects met. In a second experiment, the participants' spatial perception of a sound was biased towards a location where they imagined seeing the brief appearance of a white circle. In the third experiment, the participants' perception of what a person was saying was changed by their imagination of a particular sound.

According to the scientists, the results of the current study may be useful in understanding the mechanisms by which the brain fails to distinguish between thought and reality in certain psychiatric disorders such as schizophrenia. Another area of use could be research on brain computer interfaces, where paralyzed individuals' imagination is used to control virtual and artificial devices.

"This is the first set of experiments to definitively establish that the sensory signals generated by one's imagination are strong enough to change one's real-world perception of a different sensory modality" says Professor Henrik Ehrsson, the principle investigator behind the study.


Saturday, June 29, 2013

A Telescope for Your Eye: New Contact Lens Design May Improve Sight of Patients With Macular Degeneration


Contact lenses correct many people's eyesight but do nothing to improve the blurry vision of those suffering from age-related macular degeneration (AMD), the leading cause of blindness among older adults in the western world. That's because simply correcting the eye's focus cannot restore the central vision lost from a retina damaged by AMD. Now a team of researchers from the United States and Switzerland led by University of California San Diego Professor Joseph Ford has created a slim, telescopic contact lens that can switch between normal and magnified vision. With refinements, the system could offer AMD patients a relatively unobtrusive way to enhance their vision.

This image shows five views of the switchable telescopic contact lens. a) From front. b) From back. c) On the mechanical model eye. d) With liquid crystal glasses. Here, the glasses block the unmagnified central portion of the lens. e) With liquid crystal glasses. Here, the central portion is not blocked.
This image shows five views of the switchable telescopic contact lens. a) From front. b) From back. c) On the mechanical model eye. d) With liquid crystal glasses. Here, the glasses block the unmagnified central portion of the lens. e) With liquid crystal glasses. Here, the central portion is not blocked. (Credit: Optics Express)

The team reports its work in the Optical Society's (OSA) open-access journal Optics Express.

Visual aids that magnify incoming light help AMD patients see by spreading light around to undamaged parts of the retina. These optical magnifiers can assist patients with a variety of important everyday tasks such as reading, identification of faces, and self-care. But these aids have not gained widespread acceptance because they either use bulky spectacle-mounted telescopes that interfere with social interactions, or micro-telescopes that require surgery to implant into the patient's eye.

"For a visual aid to be accepted it needs to be highly convenient and unobtrusive," says co-author Eric Tremblay of the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland. A contact lens is an "attractive compromise" between the head-mounted telescopes and surgically implanted micro-telescopes, Tremblay says.

The new lens system developed by Ford's team uses tightly fitting mirror surfaces to make a telescope that has been integrated into a contact lens just over a millimeter thick. The lens has a dual modality: the center of the lens provides unmagnified vision, while the ring-shaped telescope located at the periphery of the regular contact lens magnifies the view 2.8 times.

To switch back and forth between the magnified view and normal vision, users would wear a pair of liquid crystal glasses originally made for viewing 3-D televisions. These glasses selectively block either the magnifying portion of the contact lens or its unmagnified center. The liquid crystals in the glasses electrically change the orientation of polarized light, allowing light with one orientation or the other to pass through the glasses to the contact lens.

The team tested their design both with computer modeling and by fabricating the lens. They also created a life-sized model eye that they used to capture images through their contact lens-eyeglasses system. In constructing the lens, researchers relied on a robust material commonly used in early contact lenses called polymethyl methacrylate (PMMA). The team needed that robustness because they had to place tiny grooves in the lens to correct for aberrant color caused by the lens' shape, which is designed to conform to the human eye.

Tests showed that the magnified image quality through the contact lens was clear and provided a much larger field of view than other magnification approaches, but refinements are necessary before this proof-of-concept system could be used by consumers. The researchers report that the grooves used to correct color had the side effect of degrading image quality and contrast. These grooves also made the lens unwearable unless it is surrounded by a smooth, soft "skirt," something commonly used with rigid contact lenses today. Finally, the robust material they used, PMMA, is not ideal for contact lenses because it is gas-impermeable and limits wear to short periods of time.

The team is currently pursuing a similar design that will still be switchable from normal to telescopic vision, but that will use gas-permeable materials and will correct aberrant color without the need for grooves to bend the light. They say they hope their design will offer improved performance and better sight for people with macular degeneration, at least until a more permanent remedy for AMD is available.

"In the future, it will hopefully be possible to go after the core of the problem with effective treatments or retinal prosthetics," Tremblay says. "The ideal is really for magnifiers to become unnecessary. Until we get there, however, contact lenses may provide a way to make AMD a little less debilitating."


Friday, June 28, 2013

Breaking habits before they start


Our daily routines can become so ingrained that we perform them automatically, such as taking the same route to work every day. Some behaviors, such as smoking or biting your fingernails, become so habitual that we can't stop even if we want to.


Although breaking habits can be hard, MIT neuroscientists have now shown that they can prevent them from taking root in the first place, in rats learning to run a maze to earn a reward. The researchers first demonstrated that activity in two distinct brain regions is necessary in order for habits to crystallize. Then, they were able to block habits from forming by interfering with activity in one of the brain regions—the infralimbic (IL) cortex, which is located in the prefrontal cortex.

The MIT researchers, led by Institute Professor Ann Graybiel, used a technique called optogenetics to block activity in the IL cortex. This allowed them to control cells of the IL cortex using light. When the cells were turned off during every maze training run, the rats still learned to run the maze correctly, but when the reward was made to taste bad, they stopped, showing that a habit had not formed. If it had, they would keep going back by habit.

"It's usually so difficult to break a habit," Graybiel says. "It's also difficult to have a habit not form when you get a reward for what you're doing. But with this manipulation, it's absolutely easy. You just turn the light on, and bingo."

Graybiel, a member of MIT's McGovern Institute for Brain Research, is the senior author of a paper describing the findings in the June 27 issue of the journal Neuron. Kyle Smith, a former MIT postdoc who is now an assistant professor at Dartmouth College, is the paper's lead author.

Patterns of habitual behavior

Previous studies of how habits are formed and controlled have implicated the IL cortex as well as the striatum, a part of the brain related to addiction and repetitive behavioral problems, as well as normal functions such as decision-making, planning and response to reward. It is believed that the motor patterns needed to execute a habitual behavior are stored in the striatum and its circuits.

Recent studies from Graybiel's lab have shown that disrupting activity in the IL cortex can block the expression of habits that have already been learned and stored in the striatum. Last year, Smith and Graybiel found that the IL cortex appears to decide which of two previously learned habits will be expressed.

"We have evidence that these two areas are important for habits, but they're not connected at all, and no one has much of an idea of what the cells are doing as a habit is formed, as the habit is lost, and as a new habit takes over," Smith says.

To investigate that, Smith recorded activity in cells of the IL cortex as rats learned to run a maze. He found activity patterns very similar to those that appear in the striatum during habit formation. Several years ago, Graybiel found that a distinctive "task-bracketing" pattern develops when habits are formed. This means that the cells are very active when the animal begins its run through the maze, are quiet during the run, and then fire up again when the task is finished.

This kind of pattern "chunks" habits into a large unit that the brain can simply turn on when the habitual behavior is triggered, without having to think about each individual action that goes into the habitual behavior.

The researchers found that this pattern took longer to appear in the IL cortex than in the striatum, and it was also less permanent. Unlike the pattern in the striatum, which remains stored even when a habit is broken, the IL cortex pattern appears and disappears as habits are formed and broken. This was the clue that the IL cortex, not the striatum, was tracking the development of the habit.

Multiple layers of control


The researchers' ability to optogenetically block the formation of new habits suggests that the IL cortex not only exerts real-time control over habits and compulsions, but is also needed for habits to form in the first place.

"The previous idea was that the habits were stored in the sensorimotor system and this cortical area was just selecting the habit to be expressed. Now we think it's a more fundamental contribution to habits, that the IL cortex is more actively making this happen," Smith says.

This arrangement offers multiple layers of control over habitual behavior, which could be advantageous in reining in automatic behavior, Graybiel says. It is also possible that the IL cortex is contributing specific pieces of the habitual behavior, in addition to exerting control over whether it occurs, according to the researchers. They are now trying to determine whether the IL cortex and the striatum are communicating with and influencing each other, or simply acting in parallel.

The study suggests a new way to look for abnormal activity that might cause disorders of repetitive behavior, Smith says. Now that the researchers have identified the neural signature of a normal habit, they can look for signs of habitual behavior that is learned too quickly or becomes too rigid. Finding such a signature could allow scientists to develop new ways to treat disorders of repetitive behavior by using deep brain stimulation, which uses electronic impulses delivered by a pacemaker to suppress abnormal brain activity.

Journal reference: Neuron

Provided by Massachusetts Institute of Technolog


Wednesday, June 26, 2013

Video Game Tech Used to Steer Cockroaches On Autopilot


North Carolina State University researchers are using video game technology to remotely control cockroaches on autopilot, with a computer steering the cockroach through a controlled environment. The researchers are using the technology to track how roaches respond to the remote control, with the goal of developing ways that roaches on autopilot can be used to map dynamic environments -- such as collapsed buildings.

North Carolina State University researchers are using video game technology to remotely control cockroaches on autopilot, with a computer steering the cockroach through a controlled environment.
North Carolina State University researchers are using video game technology to remotely control cockroaches on autopilot, with a computer steering the cockroach through a controlled environment. (Credit: Alper Bozkurt)

The researchers have incorporated Microsoft's motion-sensing Kinect system into an electronic interface developed at NC State that can remotely control cockroaches. The researchers plug in a digitally plotted path for the roach, and use Kinect to identify and track the insect's progress. The program then uses the Kinect tracking data to automatically steer the roach along the desired path.

The program also uses Kinect to collect data on how the roaches respond to the electrical impulses from the remote-control interface. This data will help the researchers fine-tune the steering parameters needed to control the roaches more precisely.

"Our goal is to be able to guide these roaches as efficiently as possible, and our work with Kinect is helping us do that," says Dr. Alper Bozkurt, an assistant professor of electrical and computer engineering at NC State and co-author of a paper on the work.

"We want to build on this program, incorporating mapping and radio frequency techniques that will allow us to use a small group of cockroaches to explore and map disaster sites," Bozkurt says. "The autopilot program would control the roaches, sending them on the most efficient routes to provide rescuers with a comprehensive view of the situation."

The roaches would also be equipped with sensors, such as microphones, to detect survivors in collapsed buildings or other disaster areas. "We may even be able to attach small speakers, which would allow rescuers to communicate with anyone who is trapped," Bozkurt says.

Bozkurt's team had previously developed the technology that would allow users to steer cockroaches remotely, but the use of Kinect to develop an autopilot program and track the precise response of roaches to electrical impulses is new.

The interface that controls the roach is wired to the roach's antennae and cerci. The cerci are sensory organs on the roach's abdomen, which are normally used to detect movement in the air that could indicate a predator is approaching -- causing the roach to scurry away. But the researchers use the wires attached to the cerci to spur the roach into motion. The wires attached to the antennae send small charges that trick the roach into thinking the antennae are in contact with a barrier and steering them in the opposite direction.

The paper, "Kinect-based System for Automated Control of Terrestrial Insect Biobots," will be presented at the Remote Controlled Insect Biobots Minisymposium at the 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society July 4 in Osaka, Japan. Lead author of the paper is NC State undergraduate Eric Whitmire. Co-authors are Bozkurt and NC State graduate student Tahmid Latif. The research was supported by the National Science Foundation.


Tuesday, June 25, 2013

Action needed to help tobacco users quit across the globe


More than half of the countries who signed the WHO 2005 Framework Convention on Tobacco Control have not formed plans to help tobacco users quit.


The World Health Organization Framework Convention on Tobacco Control (WHO FCTC) is a treaty developed to tackle the global tobacco epidemic that is killing 5 million people each year. It came into force in 2005 and is legally binding in 175 countries. The FCTC requires each country to develop plans to help tobacco users in their population to stop -- plans that should be based on strong scientific evidence for what works.

Two surveys of 121 countries just published in the scientific journal Addiction reveal that more than half of those countries have yet to develop these plans.

Just 53 of the 121 countries surveyed (44%) report having treatment guidelines: 75% of the high-income countries; 42% of upper-middle-income countries, 30% of lower-middle-income countries and only 11% of low-income countries.

Only one-fifth of the countries surveyed had a dedicated budget for treating tobacco dependence.

Commenting on the findings, Professor Robert West, Editor-in-Chief of Addiction, said: "Tobacco dependence treatment is a very inexpensive way of saving lives, much cheaper and more effective than many of the clinical services routinely provided by health systems worldwide. These reports map out for the first time the work that needs to be done to make this treatment accessible to those who could benefit from it. I hope they will be a spur to action."


Monday, June 24, 2013

Consider a Text for Teen Suicide Prevention and Intervention, Research Suggests


Adolescents Commonly Use Social Media to Reach Out When They are Depressed

"Obviously this is a place where adolescents are expressing their feelings. It leads me to believe that we need to think about using social media as an intervention and as a way to connect with people."

Teens and young adults are making use of social networking sites and mobile technology to express suicidal thoughts and intentions as well as to reach out for help, two studies suggest.

An analysis of about one month of public posts on MySpace revealed 64 comments in which adolescents expressed a wish to die. Researchers conducted a follow-up survey of young adults and found that text messages were the second-most common way for respondents to seek help when they felt depressed. Talking to a friend or family member ranked first.

These young adults also said they would be least likely to use suicide hotlines or online suicide support groups – the most prevalent strategy among existing suicide-prevention initiatives.

The findings of the two studies suggest that suicide prevention and intervention efforts geared at teens and young adults should employ social networking and other types of technology, researchers say.

“Obviously this is a place where adolescents are expressing their feelings,” said Scottye Cash, associate professor of social work at The Ohio State University and lead author of the studies. “It leads me to believe that we need to think about using social media as an intervention and as a way to connect with people.”

The research team is in the process conducting a study similar to the MySpace analysis by examining young people’s Twitter messages for suicidal content. The researchers would like to analyze Facebook, but too few of the profiles are public, Cash said.

Suicide is the third leading cause of death among youths between the ages of 10 and 24 years, according to the Centers for Disease Control and Prevention (CDC).

Cash and colleagues published the MySpace research in a recent issue of the journal Cyberpsychology, Behavior and Social Networking. They presented the survey findings at a meeting of the American Academy of Child and Adolescent Psychiatry.

Cash’s interest in this phenomenon was sparked in part by media reports about teenagers using social media to express suicidal thoughts and behaviors.

“We wanted to know: Is that accurate, or are these isolated incidents? We found that in a short period of time, there were dozens of examples of teens with suicidal thoughts using MySpace to talk to their friends,” she said.

The researchers performed a content analysis of public profiles on MySpace. They downloaded profile pages of a 41,000-member sample of 13- to 24-year-olds from March 3-4, 2008, and again in December 2008, this time with comments included. By developing a list of phrases to identify potential suicidal thoughts or behaviors, the researchers narrowed 2 million downloaded comments to 1,083 that contained suggestions of suicidality, and used a manual process to eventually arrive at 64 posts that were clear discussions of suicide.

“There’s a lot of drama and angst in teenagers so in a lot of cases, they might say something ‘will kill them’ but not really mean it. Teasing out that hyperbole was an intense process,” Cash said. Song lyrics also made up a surprising number of references to suicide, she added.

The three most common phrases within the final sample were “kill myself” (51.6 percent), “want to die” (15.6 percent) and “suicide” (14.1 percent). Though in more than half of the posts the context was unknown, Cash and colleagues determined that 42 percent of the posts referred to problems with family or other relationships – including 15.6 percent that were about break-ups – and 6.3 percent were attributable to mental health problems or substance abuse.

Very few of the posts identified the method the adolescents would consider in a suicide attempt, but 3 percent mentioned guns, 1.6 percent referred to a knife and 1.6 percent combined being hit by a car and a knife.

With this information in hand, Cash and co-investigator Jeffrey Bridge of the Research Institute at Nationwide Children’s Hospital surveyed young people to learn more about how they convey their depression and suicidal thoughts. Bridge also co-authored the MySpace paper.

Collaborating with Research Now, a social marketing firm, the researchers obtained a sample of survey participants through a company that collects consumer opinions. The final sample included 1,089 participants age 18-24 with an average age of almost 21, half male and half female, and 70.6 percent white.

They were asked about their history of suicidal thoughts and attempts, general Internet and technology use, social networking activity and whether they had symptoms of depression.

More than a third reported they have had suicidal thoughts; of those, 37.5 percent had attempted suicide, resulting in a 13 percent rate of suicide attempts among the entire sample. That figure compares to the 8 percent of U.S. high-school students who reported in a 2011 CDC national survey that they had attempted suicide at least once in the previous year. According to that survey, almost 16 percent of youths had seriously considered suicide and almost 13 percent had made a suicide plan in the previous 12 months.

Results of Cash’s survey showed that respondents would favor talking to a friend or family member when they were depressed, followed by sending texts, talking on the phone, using instant messaging and posting to a social networking site. Less common responses included talking to a health-care provider, posting to a blog, calling a suicide prevention hotline and posting to an online suicide support group.

Response trends suggested, though, that participants with suicidal thoughts or attempts were more willing to use technology – specifically the phone, instant messaging, texting and social networking – to reach out compared to those with no suicidal history. In light of this trend, the fact that the participants were active online consumers might have contributed to the relatively high percentage of suicide attempts among the study sample. In addition, the survey also asked about lifetime suicide history, not just recent history, Cash noted.

The survey also showed that this age group looks to the Internet for information on sensitive topics, and again suggested that young adults of both sexes with a history of suicidal thoughts or attempts consulted the Internet for information about topics that are difficult to discuss – specifically drug use, sex, depression, eating disorders or other mental health concerns. Females with past suicide attempts used social networking the most, according to the results.

“It appears that our methods of reaching out to adolescents and young adults is not actually meeting them where they are. If, as adults, we’re saying, ‘this is what we think you need’ and they tell us they’re not going to use it, should we keep pumping resources into suicide hotlines?” Cash said. “We need to find new ways to connect with them and help them with whatever they’re struggling with, or, in other words, meet them where they are in ways that make sense to them.”

A notable resource already available is www.reachout.com, a website geared toward adolescents who are struggling through a tough time. Some Internet-based resources exist that could serve as models for new suicide prevention interventions, she noted. They include teen.smokefree.gov and www.thatsnotcool.com

The survey research was supported by an Ohio State University College of Social Work Seed Grant.

Additional co-authors of the MySpace paper include Michael Thelwall of the University of Wolverhampton in the United Kingdom, Sydney Peck of Elmira College and Jared Ferrell of the University of Akron.

#

Contact: Scottye Cash, Cash.33@osu.edu (Email is the best way to reach Cash.)

Written by Emily Caldwell, (614) 292-8310; Caldwell.151@osu.edu


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