Neuroscientists link brain-wave pattern to energy consumption

Emery Brown, an MIT professor of brain and cognitive sciences and health sciences and technology, left, and ShiNung Ching, a postdoc in Brown’s lab. Photo: M. Scott Brauer

Different brain states produce different waves of electrical activity, with the alert brain, relaxed brain and sleeping brain producing easily distinguishable electroencephalogram (EEG) patterns. These patterns change even more dramatically when the brain goes into certain deeply quiescent states during general anesthesia or a coma. 

MIT and Harvard University researchers have now figured out how one such quiescent state, known as burst suppression, arises. The finding, reported in the online edition of the Proceedings of the National Academy of Sciences the week of Feb. 6, could help researchers better monitor other states in which burst suppression occurs. For example, it is also seen in the brains of heart attack victims who are cooled to prevent brain damage due to oxygen deprivation, and in the brains of patients deliberately placed into a medical coma to treat a traumatic brain injury or intractable seizures.

During burst suppression, the brain is quiet for up to several seconds at a time, punctuated by short bursts of activity. Emery Brown, an MIT professor of brain and cognitive sciences and health sciences and technology and an anesthesiologist at Massachusetts General Hospital, set out to study burst suppression in the anesthetized brain and other brain states in hopes of discovering a fundamental mechanism for how the pattern arises. Such knowledge could help scientists figure out how much burst suppression is needed for optimal brain protection during induced hypothermia, when this state is created deliberately. 

“You might be able to develop a much more principled way to guide therapy for using burst suppression in cases of medical coma,” says Brown, senior author of the PNAS paper. “The question is, how do you know that patients are sufficiently brain-protected? Should they have one burst every second? Or one every five seconds?”

Modeling electrical activity

ShiNung Ching, a postdoc in Brown’s lab and lead author of the PNAS paper, developed a model to describe how burst suppression arises, based on the behavior of neurons in the brain. Neuron firing is controlled by the activity of channels that allow ions such as potassium and sodium to flow in and out of the cell, altering its voltage.

For each neuron, “we’re able to mathematically model the flow of ions into and out of the cell body, through the membrane,” Ching says. In this study, the team combined many neurons to create a model of a large brain network. By showing how both cooling and certain anesthetic drugs reduce the brain’s use of ATP (the cell’s energy currency), the researchers were able to generate burst-suppression patterns consistent with those actually seen in human patients. 

This is the first time that reductions in metabolic activity at the neuron level have been linked to burst suppression, and suggests that the brain likely uses burst suppression to conserve vital energy during times of trauma.

“What’s really exciting about this is the idea that the metabolic regulation of cell energy stores plays a role in the observed dynamics of EEG. That’s a different way to think about the determinants of EEG,” says Nicholas Schiff, a professor of neurology and neuroscience at Weill Cornell Medical College who was not involved in this research. 

The developing brain

Burst suppression is also seen in babies born prematurely. As these babies get older, their brain patterns move into the normal continuous pattern. Brown speculates that in premature infants, the brain may be protecting itself by conserving energy.

“When you’re looking at these kids develop, we can easily start to suggest ways of tracking their improvement quantitatively. So the same algorithms we use to track burst suppression in the operating room could be used to track the disappearance of burst suppression in these kids,” Brown says.

Such tracking could help doctors determine whether premature infants are moving toward normal development or have an underlying brain disorder that might otherwise go undiagnosed, Ching says. 

In future studies, the researchers plan to study premature infants as well as patients whose brains are cooled and those in induced comas. Such studies could reveal just how much burst suppression is enough to protect the brain in those vulnerable situations.

Provided by Massachusetts Institute of Technology

This story is republished courtesy of MIT News (http://web.mit.edu/newsoffice/

 

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"Neuroscientists link brain-wave pattern to energy consumption." February 8th, 2012. http://medicalxpress.com/news/2012-02-neuroscientists-link-brain-wave-pattern-energy.html

 

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'Explorers,' who embrace the uncertainty of choices, use specific part of cortex

"Explorers," whose decision-making style embraces the possibilities of uncertainty, use specific parts (red) of the right rostrolateral prefrontal cortex to make calculations based on relative uncertainty. Credit: Badre-Frank Lab/Brown University

Life shrouds most choices in mystery. Some people inch toward a comfortable enough spot and stick close to that rewarding status quo. Out to dinner, they order the usual. Others consider their options systematically or randomly. But many choose to grapple with the uncertainty head on. "Explorers" order the special because they aren't sure they'll like it. It's a strategy of maximizing rewards by discovering whether as yet unexplored options might yield better returns. In a new study, Brown University researchers show that such explorers use a specific part of their brain to calculate the relative uncertainty of their choices, while non-explorers do not.

The study, published in the journal Neuron, newly exposes an aspect of the brain's architecture for producing decisions and learning, said co-author David Badre, assistant professor of cognitive, linguistic, and psychological sciences at Brown. There was no consensus that a precise area of the prefrontal cortex, in this case the right rostrolateral prefrontal cortex, would be so clearly associated with a specific operation, such as performing the requisite uncertainty comparison for supporting a decision-making strategy.

"There has long been a debate about the functional organization of the frontal cortex," Badre said. "There has been a notion that the frontal lobe lacks specialization when exercising cognitive control, that it's undifferentiated. This study provides evidence that there is a kind of organization. This is an example of how higher-order functions such as decision-making may relate to the frontal lobe's more general functional architecture."

Stop the clock

To spot explorer behavior among their 15 participants, Badre and Michael Frank, associate professor of cognitive, linguistic, and psychological sciences, slid them into an MRI scanner and presented them with a game to play. Participants had to stop the sweeping hand of a virtual clock to win points in different rounds. They were told that they could maximize their rewards by responding quickly in some rounds, and slowly in others. The trick is they did not know round-to-round which response prevailed, and the number of points they could win was highly variable. They therefore had to employ a strategy to discover how to maximize their rewards among uncertain options, keeping track of the current expected value of fast and slow responses in each round.

While the MRI scanner tracked the blood flow in the brains of the subjects — a proxy for neural activity — the game's software tracked their response times in each round. The computer then fed the game's data into mathematical models devised to determine whether participants adapted their response times by taking relative uncertainty into account or adapted in another manner.

Over dozens of rounds a clear pattern emerged. Regardless of which version of the model they used, the researchers found that about half the subjects were engaging in exploratory behavior based on uncertainty: Their choices of response times correlated strongly with the choices that had the greatest outcome uncertainty.

Badre, Frank, and their team then looked at the MRI scans, reasoning that if decision-making is based on relative uncertainty, then the subjects' brains must somehow represent this uncertainty. Sure enough, as relative uncertainty between choice options increased, so did activation in the right rostrolateral prefrontal cortex. This effect was substantially stronger in the explorers than the nonexplorers.

The result is the first to show that this region of the brain keeps track of relative uncertainty to guide exploration, but is consistent with previous studies that have shown an association between the right rostrolateral prefrontal cortex and relative comparisons. It also provides a potential explanation for Frank's previous findings that explorers were more likely to have a variation in a gene called COMT that affects dopamine levels in the prefrontal cortex.

From cortex to choice

Frank said researchers still don't know why some people employ the explorer strategy while others do not, but they might not be so different. According to one hypothesis, they all have an aversion to uncertainty and ambiguity.

"The difference could be that some people are averse to ambiguity in the time point where they make a single decision and other people are averse to ambiguity about their strategy over the long run," Frank said.

In other words, explorers may seek to reduce uncertainty by confronting it, rather than avoiding it.

Badre said that while the study has no direct clinical implications, the findings may still inform efforts to understand a broad set of disorders that affect frontal lobe function.

"There are a lot of diseases and disorders that affect the frontal lobes," Badre said. "They affect the ability to live independently, to carry out the day and make good decisions that get you where you want to go. The more we know about the specificity of these systems, the better that you can diagnose and suggest treatments."

Provided by Brown University

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Unusual alliances enable movement

 

Some unusual alliances are necessary for you to wiggle your fingers, researchers report. Understanding those relationships should enable better treatment of neuromuscular diseases, such as myasthenia gravis, which prevent muscles from taking orders from your brain, said Dr. Lin Mei, director of the Institute of Molecular Medicine and Genetics at Georgia Health Sciences University. Credit: Phil Jones, GHSU Photographer

Some unusual alliances are necessary for you to wiggle your fingers, researchers report.

Understanding those relationships should enable better treatment of neuromuscular diseases, such as myasthenia gravis, which prevent muscles from taking orders from your brain, said Dr. Lin Mei, Director of the Institute of Molecular Medicine and Genetics at Georgia Health Sciences University.

During development, neurons in the spinal cord reach out to muscle fibres to form a direct line of communication called the neuromuscular junction. Once complete, motor neurons send chemical messengers, called acetylcholine, via that junction so you can text, walk, or breathe.

As a first step in laying down the junction, motor neurons release the protein again, which reaches out to LRP4, a protein on the muscle cell surface. This activates MuSK, an enzyme that supports the clustering of receptors on the muscle cell surface that will enable communication between the brain and muscle. The precise alignment between the neuron and muscle cell that occurs during development ensures there is no confusion about what the brain is telling the muscle to do.

A missing piece was how agrin and LRP4 get together.

A study published in the journal Genes & Development shows that in the space between the neuron and its muscle cell, agrin and LRP4 first form two diverse work teams: each team has one agrin and one LRP4. The two teams then merge to form a four-molecule complex essential to MuSK activation and to the clustering of receptors that will receive the chemical messenger acetylcholine on the muscle cell.

It was expected that the two agrins would get together first then prompt the LRP4s to merge. "This is very novel," said Mei, and an important finding in efforts to intervene in diseases that attack the neuromuscular junction.

Mei and Dr. Rongsheng Jin, neuroscientist and structural biologist in the Del E. Webb Neuroscience, Aging and Stem Cell Research Center at Sanford-Burnham Medical Research Institute in La Jolla, Calif., are co-corresponding authors of the study.

Myasthenia gravis, which paralyzes previously healthy individuals, targets these protein workers. The condition, which can run in families, likely results from a process called mimicry in which the immune system starts making antibodies to the workers, which it confuses with a previous viral or bacterial infection. The majority of patients have antibodies to acetylcholine receptors, and a smaller percentage have antibodies to MuSK. Most recently, GHSU researchers also helped identify LRP4 as an antibody target.

The scientists already are looking at the impact of the antibodies on the LRP4 complex. Understanding its unique structure is essential to designing drugs that could one day block such attacks. "Prior to this we had no idea how they interacted," Mei said.

In addition to providing new information on muscle diseases, this study might also have a far-reaching ripple effect in the field of neuroscience.

"This is just the beginning," says Jin. "Now that we know more about how signals are transferred during the formation of neuromuscular junctions, we can start looking at how a similar system might work in brain synapses and how it malfunctions in neurodegenerative conditions like Alzheimer's and Parkinson's diseases. If we can figure out how to trigger the formation of new brain synapses, maintain old synapses, or simply slow their disappearance, we'd be much better equipped to prevent or treat these diseases."

To reveal the novel mechanism, researchers used a technique known as X-ray crystallography, which produces 3-D "pictures" of protein at the atomic level using powerful X-ray beams.

Provided by Georgia Health Sciences University

"Unusual alliances enable movement." February 8th, 2012. http://medicalxpress.com/news/2012-02-unusual-alliances-enable-movement.html

 

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Shirdi Songs - Nee Kanule - Krishna - Manasa

Scientists strengthen memory by stimulating key site in brain

 

This undated image provided by the Fried Lab/UCLA shows a brain MRI with an arrow showing where researchers applied deep-brain stimulation during tests on learning. A painless bit of electrical current applied to the brain helped some people play a video game, and someday it might help Alzheimer's disease patients remember what they've learned, a small study suggests. The game-players had to learn where particular stores were in a virtual city. They recalled the locations better if they'd learned them while current was supplied by tiny electrodes buried in their brains. That strategy may someday help people with early Alzheimer's hang on to many kinds of memory, suggested Dr. Itzhak Fried, a neurosurgeon at the University of California, Los Angeles. But "this is obviously a preliminary result,'' he cautioned. (UCLA, Fried Lab)

Ever gone to the movies and forgotten where you parked the car? New UCLA research may one day help you improve your memory.

UCLA neuroscientists have demonstrated that they can strengthen memory in human patients by stimulating a critical junction in the brain. Published in the Feb. 9 edition of the New England Journal of Medicine, the finding could lead to a new method for boosting memory in patients with early Alzheimer's disease.

The UCLA team focused on a brain site called the entorhinal cortex. Considered the doorway to the hippocampus, which helps form and store memories, the entorhinal cortex plays a crucial role in transforming daily experience into lasting memories.

"The entorhinal cortex is the golden gate to the brain's memory mainframe," explained senior author Dr. Itzhak Fried, professor of neurosurgery at the David Geffen School of Medicine at UCLA. "Every visual and sensory experience that we eventually commit to memory funnels through that doorway to the hippocampus. Our brain cells must send signals through this hub in order to form memories that we can later consciously recall."

Fried and his colleagues followed seven epilepsy patients who already had electrodes implanted in their brains to pinpoint the origin of their seizures. The researchers monitored the electrodes to record neuron activity as memories were being formed.

Using a video game featuring a taxi cab, virtual passengers and a cyber city, the researchers tested whether deep-brain stimulation of the entorhinal cortex or the hippocampus altered recall. Patients played the role of cab drivers who picked up passengers and traveled across town to deliver them to one of six requested shops.

"When we stimulated the nerve fibers in the patients' entorhinal cortex during learning, they later recognized landmarks and navigated the routes more quickly," said Fried. "They even learned to take shortcuts, reflecting improved spatial memory.

"Critically, it was the stimulation at the gateway into the hippocampus – and not the hippocampus itself – that proved effective," he added.

The use of stimulation only during the learning phase suggests that patients need not undergo continuous stimulation to boost their memory, but only when they are trying to learn important information, Fried noted. This may lead the way to neuro-prosthetic devices that can switch on during specific stages of information processing or daily tasks.

Six million Americans and 30 million people worldwide are newly diagnosed with Alzheimer's disease each year. The progressive disorder is the sixth leading cause of death in the United States and the fifth leading cause of death for those aged 65 and older.

"Losing our ability to remember recent events and form new memories is one of the most dreaded afflictions of the human condition," said Fried. "Our preliminary results provide evidence supporting a possible mechanism for enhancing memory, particularly as people age or suffer from early dementia. At the same time, we studied a small sample of patients, so our results should be interpreted with caution."

Future studies will determine whether deep-brain stimulation can enhance other types of recall, such as verbal and autobiographical memories. No adverse effects of the stimulation were reported by the seven patients.

Fried's coauthors included first author Nanthia Suthana, as well as Dr. Zulfi Haneef, Dr. John Stern, Roy Mukamel, Eric Behnke and Barbara Knowlton, all of UCLA. The research was supported by grants from the National Institute of Neurological Disorders and Stroke and the Dana Foundation.

Provided by University of California - Los Angeles

"Scientists strengthen memory by stimulating key site in brain." February 8th, 2012. http://medicalxpress.com/news/2012-02-scientists-memory-key-site-brain.html

 

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UK researchers rank best online advice for postnatal depression

(Medical Xpress) -- Researchers at the University of Sussex have identified the top five internet sites offering support for women struggling with postnatal mental illness such as depression or anxiety. Around 10-15 per cent of new mothers are diagnosed with postnatal mental illnesses, while around one in four women may have significant post-birth distress without meeting the criteria for a disorder. Many women turn to the internet to seek advice and reassurance over these conditions.
Health psychologists Donna Moore and Dr. Susan Ayers sorted through thousands of web sites and whittled down their selection to the top five sites for new mothers seeking information about postnatal depression and anxiety and the top five for healthcare professionals looking for ways to support patients.



For mums they are:
www.panda.org.au
www.hapis.org.uk
www.postpartumhealthalliance.org
www.postpartum.net
www.pndsa.co.za
And for health professionals:
www.postpartum.net
www.postpartumhealthalliance.org
 www.babybluesconnection.org
www.postpartumsupport.com
www.postpartumeducationandsupport.com
The research, published in the journal Archives of Women’s Mental Health, offers the latest systematic survey of web advice for postnatal psychological problems and serves as an authoritative guide to most reliable sites.
Women can suffer from various psychological problems after having a baby that range from mild baby blues to more severe depression, anxiety and psychosis. The researchers found that although there were thousands of sites devoted to postnatal depression (typing “postnatal depression” into Google returned more than a million results), the quality was extremely variable, with very few sites offering the full spectrum of easily accessed support, advice, information and reassurance about the different psychological problems women might encounter.
Many sites were hard to navigate, suffered from poorly edited content or had information that was out of date or just plain wrong.  Information focused on symptoms rather than risk factors or the potential negative impact of not dealing with the illness on children and families as well as the sufferer. There was some information on treatment, but it was generally superficial.
Most websites rarely had prominent information on what the users should do if they have thoughts of harming themselves or their infant.
Donna Moore says: “Most web sites did encourage women to seek medical help. However, information tended to be about depressive symptoms and largely ignored other forms of postnatal illness,namely anxiety, post traumatic stress disorder and puerperal psychosis. This could reinforce the common misconception that postnatal mental illness is solely depression or simply an extension of the ‘baby blues’.  Mothers need to know what the signs of the illness are and treatment options and health professionals need to know all the facts for effective screening. It is essential that web sites provide accurate and comprehensive information and advice for mothers and their families. Mothers need to be informed that if they get help they will get better.”
Dr. Ayers says:”The internet is often the first port of call for people worried about health issues. This is particularly the case for women suffering from depressive illness following the birth of a baby because they many find it difficult to leave the house with a young infant and, like all mental health issues, there is the fear of being stigmatised. Using the internet, therefore, provides a way of seeking reassurance, information and advice anonymously from home. Effective web sites are therefore important in directing women to the professional help they need while giving them the confidence to ask for it.”
To identify the best sites, the researchers searched for sites using the four main search engines using the terms “postnatal depression”, “postnatal illness”, “postpartum depression” and “postpartum illness”. The first 25 web sites for each key term were selected for review.
Each site had to be exclusively dedicated to postnatal mental health or have substantial information on postnatal mental illness. They were evaluated for accuracy of information, available resources and quality. A total of 114 sites were eventually surveyed.
It is hoped that through this systematic review, the top web sites will be used by healthcare professionals and help with the creation of new online resources, based on knowledge of how sufferers use web resources. Donna Moore and Susan Ayers are currently investigating how women with postnatal distress use and benefit from resources on the internet.

Accurate information on all symptoms is essential for healthcare professionals screening for postnatal mental illness and sufferers and their families deciding whether to get help.

More information: A review of postnatal mental health websites: help for healthcare professionals and patients, Archives of Women’s Mental Health.
Provided by University of Sussex
"UK researchers rank best online advice for postnatal depression." February 7th, 2012. http://medicalxpress.com/news/2012-02-uk-online-advice-postnatal-depression.html
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Robert Karl Stonjek

மனைவியைப் புரிந்து கொள்ளுங்கள்

ஒரு மனைவி, தன் கணவனிடம் அப்படி என்னதான் எதிர்பார்க்கிறாள்….? விதவிதமான பட்டுப்புடவைகளா? தங்கம், வைரம் என்று நகைக் குவியலா? பெரிய பங்களா, ஏ.சி.கார் என்று ஆடம்பர விஷயங்களா….? நிறைய சம்பளமும், ஏகப்பட்ட பேங்க் பேலன்ஸும் வேண்டுமென்றா? அல்லது தன் கணவன் மன்மதன் போல் அழகாக இருக்க வேண்டுமென்றா?

இல்லவே இல்லை…! மனைவியின் எதிர்பார்ப்பே வேறு விதமானது. அவள் அப்படி என்னதான் எதிர்பார்க்கிறாள் என்று கணவன் தெரிந்து கொண்டாலே அவர்களுடைய இல்லற வாழ்க்கை இன்னும் அன்னியோன்யம் கூடியதாக அமையும்!

கணவனிடம் ஒரு மனைவி எதிர்பார்க்கும் விசயங்கள் இவை தான்

ஆண்களே… உங்கள் மனைவியைப் புரிந்துகொள்ள இதைப் படியுங்கள்….

• அன்பாகப் பிரியமாக இருங்கள்… அதுவே ஆயிரக்கணக்கான மதிப்புள்ள புடவைகள் தராத மகிழ்ச்சியைத் தரும்!.
• மனது புண்படும்படி பேசாதீர்கள். அது உங்கள் மனைவிக்கு உங்கள் மேல் உள்ள பிரியத்தைக் கூடச் சில சமயங்களில் குறைத்துவிடக் கூடும். அது போல அடிக்கடி கோபப்படவும் செய்யாதீர்கள்.
• சாப்பாட்டில் குறை சொல்லக்கூடாது. பல கணவன்மார்கள் இதைத்தான் பெரிய கடமையாகச் செய்து கொண்டிருக்கிறார்கள். உப்பு அதிகமாக இருக்கிறது என்று நீங்கள் நினைத்தீர்கள் என்றால், இன்னிக்கி சமையல் சூப்பரா இருக்கு என்று முதலில் பாராட்டிவிடுங்கள். அப்புறம் மெதுவாக கொஞ்சம் உப்பைக் குறைச்சு போட்டிருக்கலாம் என்று சொல்லிப் பாருங்கள். உங்கள் மனைவி விஷயத்தைப் புரிந்து கொண்டு அடுத்த முறை இன்னும் சூப்பராக சமைப்பார்!
• எந்த இடத்திலும் மனைவியை விட்டுக்கொடுக்கக் கூடாது. பலர் முன்னிலையில் திட்டவோ, மரியாதைக் குறைவாகவோ பேசாதீர்கள். இது உங்கள் அன்யோன்யத்தைக் குறைத்துவிடும்.
• உறவினர் வீட்டு விசேஷங்களுக்கு மனைவியுடன் செல்லுங்கள். அது மனைவிக்கு நீங்கள் மரியாதை கொடுப்பதாகத் தோன்றச் செய்யும்.
• எந்த ஒரு விஷயத்தையும் மனைவியுடன் கலந்து ஆலோசிக்க வேண்டும்.
• மனைவி சொல்வதைக் காது கொடுத்துக் கேளுங்கள். காதுக்கு வைரத்தோடு வாங்கித் தருவதைவிட சந்தோஷம் தரும் விஷயம் இது.
• மனைவியிடம் மனம்விட்டுப் பேசுங்கள். நிறைய விஷயங்களுக்கு நல்ல தீர்வு கிடைக்கும்.
• மனைவி வித்தியாசமாக ஏதாவது செய்தால் ரசித்துப் பாராட்டுங்கள்.
• மாதம் ஒரு முறையாவது வெளியில் கூட்டிக் கொண்டு போங்கள். உங்கள் பேரிலுள்ள கோபம்கூட ஓடி விடும்.
• பிள்ளைகள் படிப்பில் அக்கறை கொண்டு உதவி செய்யுங்கள். அப்படிச் செய்தால் மனைவிக்கு இன்னும் உங்கள் மீதுள்ள காதலை அதிகப்படுத்தும்.
• இரவு விழித்து அழும் குழந்தையைப் பார்ப்பதில் உங்களுக்கு இருக்கும் அதே கஷ்டம் போலத்தான் உங்கள் மனைவிக்கும் இருக்கும். எல்லா விஷயங்களுக்கும் இது பொருந்தும்.
• மனைவி உடல்நலம் இல்லாமல் இருக்கும் பொழுது அக்கறையுடன் உடன் இருந்து கவனியுங்கள். அவளுடைய சின்னச்சின்ன தேவைகளைப் பூர்த்தி செய்து சிறு சிறு உதவிகள் செய்தாலே அவளுக்கு மிகுந்த மகிழ்ச்சி ஏற்படும்.
• அம்மாவிடம் காட்டும் பாசத்தை மனைவியிடமும் காட்டுங்கள். தாயளவுக்கு தாரமும் வாழ்க்கையில் முக்கியத்துவம் வாய்ந்தவர்தான்!
• எங்கு சென்றாலும் மனைவியிடம் சொல்லி விட்டே கிளம்புங்கள். குடும்பத்தில் பல குழப்பங்களைத் தடுக்க இது உதவும்.
• மனைவியின் பிறந்த நாளை அவரைக் கேட்காமலேயே தெரிந்து வைத்துக் கொண்டு கட்டாயம் ஏதாவது சிறு பரிசாவது வாங்கிக் கொடுங்கள். அல்லது அவளுக்கு எது பிடிக்கும் என்று தெரிந்துகொண்டு அதை இன்ப அதிர்ச்சி ஏற்படுத்தும் பரிசாகக் கொடுக்கலாம்.
• ரொம்ப முக்கியமான விஷயம் இது… மனைவியிடம் பொய் பேசாமல் இருங்கள்.
• கடைசியாக… கெட்ட பழக்கங்கள் எதுவும் இல்லாமல் இருக்கும் கணவனையே மனைவி கடவுள் தனக்குத் தந்த பெரும் வரமாக நினைப்பாள்.

Brilliant Painting From National Gallery Of London!!

Green tea found to reduce disability in the elderly

Green tea. Credit: Wikimedia Commons

(Medical Xpress) -- A lot of research has been done over the past several years looking into the health benefits of green tea. As a result, scientists have found that regular consumption of the beverage leads to a reduction in several maladies often associated with aging, such as osteoporosis, stroke and cognitive impairment. But until now, according to the authors of a new study on its benefits, no such studies have been undertaken to determine if regular tea drinking provides other benefits, such as a reduction in functional disabilities. Because of this, a research project was undertaken by a team from Tokyo’s Graduate School of Medicine, and they have found that older people who drink more green tea tend to have less functional disabilities than do those who don’t. They have published their findings in The American Journal of Clinical Nutrition.

The team describes functional disabilities as those that interfere with living a normal life, such as being able to dress or bathe without assistance, or to perform household chores, or go for a walk. To find out if drinking green tea regularly helps people ward off such disabilities as they age, the team surveyed 13,998 adults age 65 and over and followed their eating, drinking and health habits over a three year period. They also accessed Japan’s Long-term Care Insurance database to help in gathering statistics.

After compiling all the data, the team found that people who drank more of the green tea, tended to have the least number of functional disabilities. Put into numbers, they found that approximately 13% of those tested that drank one cup or less of the tea every day wound up with a functional disability, whereas only 7% of those who drank five cups or more each day became so.

The research team isn’t claiming they’ve found absolute proof that drinking a lot of green tea every day will ward of functional disabilities, but that instead their research suggests that it seems likely. They say that those who drank more green tea every day also tended to live healthier lifestyles, such as eating more fish, fruits and vegetables, staying more active and maintaining a more well-rounded social life that included family. However, they note, even after discounting such factors, those that drank more tea still did better than did those who did not.

Researchers in general aren’t really clear about why green tea has health benefits, but suspect it has something to do with a compound in it called EGCG, an antioxidant that appears to ward off cell damage that can lead to disease.

More information: Green tea consumption and the risk of incident functional disability in elderly Japanese: the Ohsaki Cohort 2006 Study, Am J Clin Nutr, First published January 25, 2012, doi: 10.3945/​ajcn.111.023200

Abstract 
Background: Previous studies have reported that green tea consumption is associated with a lower risk of diseases that cause functional disability, such as stroke, cognitive impairment, and osteoporosis. Although it is expected that green tea consumption would lower the risk of incident functional disability, this has never been investigated directly. 
Objective: The objective was to determine the association between green tea consumption and incident functional disability in elderly individuals. 
Design: We conducted a prospective cohort study in 13,988 Japanese individuals aged ≥65 y. Information on daily green tea consumption and other lifestyle factors was collected via questionnaire in 2006. Data on functional disability were retrieved from the public Long-term Care Insurance database, in which subjects were followed up for 3 y. We used Cox proportional hazards regression analysis to investigate the association between green tea consumption and functional disability. 
Results: The 3-y incidence of functional disability was 9.4% (1316 cases). The multiple-adjusted HR (95% CI) of incident functional disability was 0.90 (0.77, 1.06) among respondents who consumed 1–2 cups green tea/d, 0.75 (0.64, 0.88) for those who consumed 3–4 cups/d, and 0.67 (0.57, 0.79) for those who consumed ≥5 cups/d in comparison with those who consumed <1 cup/d (P-trend < 0.001). 
Conclusion: Green tea consumption is significantly associated with a lower risk of incident functional disability, even after adjustment for possible confounding factors.

© 2011 Medical Xpress

"Green tea found to reduce disability in the elderly." February 7th, 2012. http://medicalxpress.com/news/2012-02-green-tea-disability-elderly.html

 

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Robert Karl Stonjek

Materials for First Optical Fibers With High-Speed Electronic Function Are Developed

                                                 For the first time, researchers have developed crystalline materials that allow an optical fiber to have integrated, high-speed electronic functions. The potential applications of such optical fibers include improved telecommunications and other hybrid optical and electronic technologies, improved laser technology, and more-accurate remote-sensing devices. The international team, led by John Badding, a professor of chemistry at Penn State, will publish its findings in the journal Nature Photonics. The team built an optical fiber with a high-speed electronic junction -- the active boundary where all the electronic action takes place -- integrated adjacent to the light-guiding fiber core. Light pulses (white spheres) traveling down the fiber can be converted to electrical signals (square wave) inside the fiber by the junction. The potential applications of such optical fibers include improved telecommunications and other hybrid optical and electronic technologies and improved laser technology. (Credit: John Badding lab, Penn State University)

Science Daily — For the first time, a group of chemists, physicists, and engineers has developed crystalline materials that allow an optical fiber to have integrated, high-speed electronic functions. The potential applications of such optical fibers include improved telecommunications and other hybrid optical and electronic technologies, improved laser technology, and more-accurate remote-sensing devices. The research was initiated by Rongrui He, a postdoctoral researcher in the Department of Chemistry at Penn State University.

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The international team, led by John Badding, a professor of chemistry at Penn State, will publish its findings in the journal Nature Photonics.

Badding explained that one of the greatest current technological challenges is exchanging information between optics and electronics rapidly and efficiently. Existing technology has resulted in sometimes-clumsy ways of merging optical fibers with electronic chips -- silicon-based integrated circuits that serve as the building blocks for most semiconductor electronic devices such as solar cells, light-emitting diodes (LEDs), computers, and cell phones. "The optical fiber is usually a passive medium that simply transports light, while the chip is the piece that performs the electrical part of the equation," Badding said. "For example, light is transmitted from London to New York via fiber-optic cables when two people set up a video call on their computers. But the computer screens and associated electronic devices have to take that light and convert it to an image, which is an electrical process. Light and electricity are working in concert in a process called an OEO conversion, or an optical-electrical-optical conversion." Badding said that, ideally, rather than coupling the optical fiber to the chip, as is routine in existing technology, a "smart fiber" would have the electronic functions already built in.

The integration of optical fibers and chips is difficult for many reasons. First, fibers are round and cylindrical, while chips are flat, so simply shaping the connection between the two is a challenge. Another challenge is the alignment of pieces that are so small. "An optical fiber is 10 times smaller than the width of a human hair. On top of that, there are light-guiding pathways that are built onto chips that are even smaller than the fibers by as much as 100 times," Badding said. "So imagine just trying to line those two devices up. That feat is a big challenge for today's technology."

To address these challenges, the team members took a different approach. Rather than merge a flat chip with a round optical fiber, they found a way to build a new kind of optical fiber with its own integrated electronic component, thereby bypassing the need to integrate fiber-optics onto a chip. To do this, they used high-pressure chemistry techniques to deposit semiconducting materials directly, layer by layer, into tiny holes in optical fibers. "The big breakthrough here is that we don't need the whole chip as part of the finished product. We have managed to build the junction -- the active boundary where all the electronic action takes place -- right into the fiber," said Pier J. A. Sazio of the University of Southampton in the United Kingdom and one of the team's leaders. "Moreover, while conventional chip fabrication requires multimillion-dollar clean-room facilities, our process can be performed with simple equipment that costs much less."

Sazio added that one of the key goals of research in this field is to create a fast, all-fiber network. "If the signal never leaves the fiber, then it is a faster, cheaper, and more efficient technology," said Sazio. "Moving technology off the chip and directly onto the fiber, which is the more-natural place for light, opens up the potential for embedded semiconductors to carry optoelectronic applications to the next level. At present, you still have electrical switching at both ends of the optical fiber. If we can actually generate signals inside a fiber, a whole range of optoelectronic applications becomes possible."

The research also has many potential non-telecommunications applications. "For example, our work also represents a very different approach to fabricating semiconductor junctions that we are investigating for solar-cell applications," said Badding.

Preference for Fatty Foods May Have Genetic Roots

A preference for fatty foods has a genetic basis, according to researchers, who discovered that people with certain forms of the CD36 gene may like high-fat foods more than those who have other forms of this gene. (Credit: National Cancer Institute)                                                                                       Science Daily — A preference for fatty foods has a genetic basis, according to researchers, who discovered that people with certain forms of the CD36 gene may like high-fat foods more than those who have other forms of this gene.

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The results help explain why some people struggle when placed on a low-fat diet and may one day assist people in selecting diets that are easier for them to follow. The results also may help food developers create new low-fat foods that taste better.

"Fat is universally palatable to humans," said Kathleen Keller, assistant professor of nutritional sciences, Penn State. "Yet we have demonstrated for the first time that people who have particular forms of the CD36 gene tend to like higher fat foods more and may be at greater risk for obesity compared to those who do not have this form of the gene. In animals, CD36 is a necessary gene for the ability to both detect and develop preferences for fat. Our study is one of the first to show this relationship in humans."

Keller and a team of scientists from Penn State, Columbia University, Cornell University and Rutgers University examined 317 African-American males and females because individuals in this ethnic group are highly vulnerable to obesity and thus are at greatest risk for obesity-related diseases.

The team gave the participants Italian salad dressings prepared with varying amounts of canola oil, which is rich in long-chain fatty acids. The participants were then asked to rate their perceptions of the dressings' oiliness, fat content and creaminess on a scale anchored on the ends with "extremely low" and "extremely high."

The team also gave participants questionnaires aimed at understanding their food preferences. Participants rated how much they liked each food on a scale anchored with "dislike extremely" and "like extremely." Foods included on the questionnaire were associated with poor dietary intake and health outcomes, such as half-and-half, sour cream, mayonnaise, bacon, fried chicken, hot dogs, French fries, cheese, chips, cake, cookies and doughnuts.

The researchers collected saliva samples from the participants to determine which forms of CD36 they had. From the saliva samples, they extracted DNA fragments and examined differences in the CD36 gene contained within the fragments.

They found that participants who had the "AA" form of the gene -- present in 21 percent of the population -- rated the salad dressings as creamier than individuals who had other forms of the gene. These individuals reported that the salad dressings were creamier regardless of how much fat was actually in them. The researchers also found that "AA" individuals liked salad dressings, half-and-half, olive oil and other cooking oils more than those who had other forms of the gene. The results are published in a recent issue of the journal Obesity.

"It is possible that the CD36 gene is associated with fat intake and therefore obesity through a mechanism of oral fat perception and preference," said Keller. "In other words, our results suggest that people with certain forms of the CD36 gene may find fat creamier and more enjoyable than others. This may increase their risk for obesity and other health problems."

According to Keller, having certain forms of a gene that help in the perception and enjoyment of fats in foods might once have been an advantage.

"Fats are essential in our diets," she said. "In our evolutionary history, people who were better able to recognize fats in foods were more likely to survive. Such forms of the gene, however, are less useful to us today as most of us no longer have to worry about getting enough fats in our diets."

In fact, she added, having such forms of a gene can be detrimental in today's world of fat-laden convenience foods.

"Our results may help explain why some people have more difficulty adhering to a low-fat diet than other people and why these same people often do better when they adopt high-fat, low-carbohydrate diets such as the Atkins diet," said Keller. "We hope these results will one day help people select diets that are easier for them to follow. We also think the results could help food developers create better tasting low-fat foods that appeal to a broader range of the population."

In the future, the team plans to expand the population they examine to include children.

"By the time we are adults it is very hard for us to change our eating behaviors," said Keller. "So if we can determine which children have forms of the CD36 gene, as well as other genes that are associated with greater liking of fats, we can help them develop healthier eating behaviors at a young age."

Keller also plans to incorporate novel techniques, such as functional magnetic resonance imaging (fMRI), to better understand why certain forms of the CD36 gene are linked to higher fat preferences.

"We plan to scan children while they are tasting high-fat foods and beverages so that we can see how their brains react to fats," she said. "By doing this, we may be able to develop foods that are perceived by the brain as palatable high-fat treats, even though in reality, they are low-fat and healthy."

Kathleen Keller was an assistant professor and research associate at Columbia University and the New York Nutrition Obesity Research Center when she conducted the research. Other authors on the paper include Columbia University graduate students Lisa Liang, Johannah Sakimura, Daniel May and Christopher van Belle; Cornell University undergraduate students Cameron Breen and Elissa Driggin; and Beverly Tepper, professor, Rutgers University. Also at Columbia were Patricia Lanzano, research coordinator; Liyong Deng, research technician; and Wendy Chung, assistant professor.

The National Institutes of Health funded this research.

Placebos and Distraction: New Study Shows How to Boost the Power of Pain Relief, Without Drugs

Placebos reduce pain by creating an expectation of relief. Distraction -- say, doing a puzzle -- relieves it by keeping the brain busy. But do they use the same brain processes? Neuromaging suggests they do. (Credit: © psdesign1 / Fotolia)

Science Daily — Placebos reduce pain by creating an expectation of relief. Distraction -- say, doing a puzzle -- relieves it by keeping the brain busy. But do they use the same brain processes? Neuromaging suggests they do. When applying a placebo, scientists see activity in the dorsolateral prefrontal cortex. That's the part of the brain that controls high-level cognitive functions like working memory and attention -- which is what you use to do that distracting puzzle.

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Now a new study challenges the theory that the placebo effect is a high-level cognitive function. The authors -- Jason T. Buhle, Bradford L. Stevens, and Jonathan J. Friedman of Columbia University and Tor D. Wager of the University of Colorado Boulder -- reduced pain in two ways -- either by giving them a placebo, or a difficult memory task. lacebo. But when they put the two together, "the level of pain reduction that people experienced added up. There was no interference between them," says Buhle. "That suggests they rely on separate mechanisms." The findings, published inPsychological Science, a journal of the Association for Psychological Science, could help clinicians maximize pain relief without drugs.

In the study, 33 participants came in for three separate sessions. In the first, experimenters applied heat to the skin with a little metal plate and calibrated each individual's pain perceptions. In the second session, some of the people applied an ordinary skin cream they were told was a powerful but safe analgesic. The others put on what they were told was a regular hand cream. In the placebo-only trials, participants stared at a cross on the screen and rated the pain of numerous applications of heat -- the same level, though they were told it varied. For other trials they performed a tough memory task -- distraction and placebo simultaneously. For the third session, those who'd had the plain cream got the "analgesic" and vice versa. The procedure was the same.

The results: With either the memory task or the placebo alone, participants felt less pain than during the trials when they just stared at the cross. Together, the two effects added up; they didn't interact or interfere with each other. The data suggest that the placebo effect does not require executive attention or working memory.

So what about that neuroimaging? "Neuroimaging is great," says Buhle, "but because each brain region does many things, when you see activation in a particular area, you don't know what cognitive process is driving it." This study tested the theory about how placebos work with direct behavioral observation.

The findings are promising for pain relief. Clinicians use both placebos and distraction -- for instance, virtual reality in burn units. But they weren't sure if one might diminish the other's efficacy. "This study shows you can use them together," says Buhle, "and get the maximum bang for your buck without medications."