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Thursday, December 15, 2011

The Most Dangerous English Letter.....!!!!!

The Most Dangerous English Letter
 
Which is the most Dangerous
Letter in English ??
The Answer is  "W"...as in Wrong
"W" is  a tension generator...
  because all the worries and troubles get begins with "W"...
What ? When ?  
Which ? Whom??
  Where ?
  War...
Wine...Whisky... Women...  
Wealth
And finally .......
 
  You have to accept this :
WHETHER YOU LIKE IT OR NOT.......
 
  WIFE.....

Researchers supply major results for understanding the thalamus, the 'relay center' of the brain




Toward a therapy to healing strokeThe findings obtained from studies of the zebrafish can be transferred to the human brain. Credit: Graphics: ITG, KIT The thalamus is the central translator in the brain: Specialized nerve cells (neurons) receive information from the sensory organs, process it, and transmit it deep into the brain. Researchers from the Institute of Toxicology and Genetics of KIT have now identified the genetic factors Lhx2 and Lhx9 responsible for the development of these neurons. Their results contribute to understanding the development of the thalamus. In the long term, they are to help healing thalamic strokes.
With 100 billion nerve cells, the brain is the most complex organ in the human body. "We want to understand the development program behind," says Dr. Steffen Scholpp from the ITG. "We want to find out how individual parts of the brain develop, this means, what makes precursor cells build a specialized area such as the thalamus." Scholpp's group at ITG studies the development of the thalamus. "It is the central interface between the brain and the outer world: Everything that is perceived via eyes, ears or the tactile sense has to pass the thalamus before it is routed to the cerebral cortex for further processing."
In the long term, the scientists want to be able to heal damaged brain parts by a tissue replacement therapy. If, for example, brain tissue is damaged after an infarct, is the body is not able to regenerate this tissue. "Today, stroke is the most frequent cause of disability acquired at adult age and due to its central role, damage of the thalamus is very serious," emphasizes Steffen Scholpp. "For this reason, we have to find a strategy to activate stem cells such that the damaged tissue can be replaced." Recently, an important step was made by the scientists: By studying zebrafish, they identified Lhx2 and Lhx9, the factors controlling the development of neurons in the thalamus. "Without these factors, the thalamus would accommodate undifferentiated nerve cells only – this means, the precursory cells lack the information required for specialization," explains the biologist. Analysis of brain development in zebrafish allows conclusions to be drawn with respect to the development in all vertebrates, including human. The results of the group are published in the current issue of the PLoS Biology journal.
In the same study, Scholpp and his team identified another factor that acts as "adhesive" in the thalamus: The cell adhesion molecule Pcdh10b ensures development of the thalamus without mixing with the surrounding brain areas. If this factor is lacking, the neurons differentiate, but do not find their target destination. It is now the objective of the researchers to activate these factors in the cultivating dish (in vitro) in undifferentiated cells first for new thalamus tissue to form. In close cooperation with engineers, the biologists are already developing 2-dimensional cell culture systems. In January, they will start a 3D cell cultivation project. "KIT offers excellent opportunities: Parallel to our research, materials researchers work on the development of various biomaterials (biopolymers) which will be tested in the cultivation experiments", says Scholpp.
Dr. Steffen Scholpp thinks that it will be possible to heal stroke patients in the future. "Of course, this will take some years. But it is our ultimate goal to take out quiescent stem cells from a stroke patient and to switch on the specific development biology program in these cells outside of the body. Finally, we plan to bring them back to the position of the damaged tissue. This would be real healing."
Under the Emmy Noether program, the German Research Foundation (DFG) has granted funding in the amount of EUR 1.3 million to Dr. Steffen Scholpp for a duration of five years. The Emmy Noether program is designed to support young scientists in establishing an own working group. The team of Dr. Steffen Scholpp presently comprises one postdoctoral research fellow, three doctoral students, a technical employee, and two master students.
Provided by Helmholtz Association of German Research Centres
"Researchers supply major results for understanding the thalamus, the 'relay center' of the brain." December 14th, 2011. http://medicalxpress.com/news/2011-12-major-results-thalamus-relay-center.html
Posted by
Robert Karl Stonjek

New vaccine targets Alzheimer’s


The University of Sydney   

IvelinRadkov_-_alzheimers
The vaccine prevents the ongoing formation of neurofibrillary tangles in the brain of a mouse with Alzheimer's disease.
Image: IvelinRadkov/iStockphoto
A vaccine that slows the progression of Alzheimer's disease and other types of dementia has been developed by researchers at the University of Sydney's Brain and Mind Research Institute (BMRI).

The vaccine, which targets a protein known as tau, prevents the ongoing formation of neurofibrillary tangles in the brain of a mouse with Alzheimer's disease.

This progressive neurodegenerative disease affects more than 35 million people worldwide. The tau protein is also involved in front temporal dementia, the second most common form of dementia in people younger than 65 years.

The results of the study which led to the production of the vaccine have been published in the scientific journal PLoS ONE.

Lead author on the study, Associate Professor Lars Ittner, from the Alzheimer's and Parkinson's Disease Laboratory says:

"Our study is the first to show that a vaccine targeting the tau protein can be effective once the disease has already set in.

"The vaccine appears to have a preventative effect: slowing the development of further tangles, rather than clearing existing ones, but the exact mechanism involved is not yet understood," he said.

According to Associate Professor Ittner, scientists have been working on vaccines targeting the amyloid plaques seen in Alzheimer's for many years with a few currently in clinical trials.

"Most of the other vaccines targeting tau were tested only before or around the onset of the disease in animal models, but the vast majority of people with Alzheimer's disease are only diagnosed after the symptoms have appeared.

"We are already collaborating with the US pharmaceutical industry to develop this new vaccine for humans.

"Although we have a long way to go before the vaccine might be available for human use, these early results are very promising and a great reward for the countless hours spent in the lab by me and my team!"
Editor's Note: Original news release can be found here.

Low carbon transport ‘healthy’



The University of Auckland   
olaser_-_bicyclePost Options
The report noted A 20-30 percent lower average risk of premature death among cyclists in some major cities, even after injury risks were considered.
Image: olaser/iStockphoto
Low carbon transport systems do more than help create a healthy planet. They can help improve the health of people according to a new World Health Organisation report, involving a University of Auckland researcher as a lead author.

The WHO report, released in Durban, shows that cycling, walking and rapid-transit systems bring a wide range of health benefits. It suggests climate experts need to take these into account in assessing and planning low-carbon transport systems.

More than 300 studies on different land transport systems were reviewed to find transport factors most closely associated with health risks or benefits. The review found a large body of evidence linking rapid-transit and non-motorised transport systems with reduced environmental health risks and increased health benefits.

Dr Jamie Hosking, lead author and Public Health Consultant from the University’s School of Population Health, saystook part in the study. “Due to the health gains, well-designed low-carbon transport systems can provide a ’win-win‘ for both developed and developing countries, and for an economic sector with a large carbon footprint,” he says. “Transport accounts for nearly one-quarter of all direct CO2 emissions worldwide.

“More compact cities, with mixed-use developments that place homes and businesses near each other, along with improved amenities for walking and cycling, are also strongly associated with better health. These benefits are most important of all for people who lack access to a car,” says Dr Hosking.

While increased physical activity from walking and cycling is well-established as a means of preventing heart disease, some cancers and type 2 diabetes, this report focuses on health outcomes in specific settings and transport systems.

The report noted, for instance, a 20-30 percent lower average risk of premature death among cyclists in some major cities, even after injury risks were considered.

The report also documents a wide range of other health benefits from prioritising transit and non-motorised networks. These include reduced noise stress, fewer road traffic injuries and lower air pollution exposures in areas where there is a strong emphasis on traffic calming, traffic diversion, and non-motorised transport.

Dr Carlos Dora, of WHO's Department of Public Health and Environment, initiated the study as part of WHO's Health in the Green Economy initiative on health co-benefits of key climate change mitigation measures. Dora is also a co-author of the series along with Dr Pierpaolo Mudu of WHO's Regional Office for Europe.

Speaking at a press briefing during COP-17 in Durban, Dr Dora noted that until now, too much emphasis had been placed on alternative vehicles and fuels in climate assessment work so far, while not enough attention had been given to strategies such as transit, walking and cycling, which can address a wide range of health risks, from pollution to safety and physical activity.

"Many kinds of climate and transport measures can yield large, immediate, benefits for health, but some climate measures may be very bad for health, for example diesel," Dr Dora noted.

"At the local level, more reliance on diesel can increase relative risks of respiratory and heart disease. Also, better fuels don’t do anything for noise, for physical activity and for safety risks. Public transport and safe cycling and walking do help reduce these risks, too."
Editor's Note: Original news release can be found here.

Kyu Aate Nahi Baba Mere Angna Mein- Shailabh Bansal Bhajan

Yoga Under Duress


Prahlada thrown off a cliff“If one is engaged in the advancement of spiritual knowledge, there will be so many insults and much dishonor from others. This is expected because material nature is so constituted. Even a boy like Prahlada, who, only five years old, was engaged in the cultivation of spiritual knowledge, was endangered when his father became antagonistic to his devotion.” (Shrila Prabhupada, Bhagavad-gita, 13.8-12 Purport)
Question: “How do I concentrate on devotional activities when I have so many pressures to maintain a family?”
Answer: In a particular episode of the famous American television sitcom, Everybody Loves Raymond, a doctor on the show compares the mind to a donkey. He says that there is only so much weight you can put on the mind before it decides to just sit down and stop moving. Though the analogy is meant to be humorous, it has merit. If we are bearing an excruciatingly large weight on our shoulders, how are we supposed to concentrate on anything else? For the fruitive worker entangled in so many responsibilities, the panacea of a life devoted to spirituality seems far, far away. But as was seen with one particular devotee a long time back, even under the most trying circumstances, if there is sincerity of purpose, the beneficiary of that service will make sure that the devotion can not only continue, but flourish.
The first instruction of the Vedas to aspiring transcendentalists is aham brahmasmi, which means “I am Brahman.” “You are not the body, don’t you see? The body is just temporary, like a lump of clay that can be molded and shaped at any second. In the larger scheme, the all-devouring agent for change known as time is responsible for the shifts, but this doesn’t mean that you are completely helpless with respect to your body’s transformation. Your actions have an influence on the rate of the change and its nature, but nevertheless, throughout the passage of time you are still pure spirit. Detach from the bodily influence and remain spiritually aware. Brahman is bliss. Brahman is truth. Brahman is eternal life.”
These truths are well and good to learn about when you are sober and able to concentrate on hearing and understanding the complex information, but what if you don’t have the time to study Brahman? For the adult family man living in the modern world, the average day is filled with pressures. Though time is continuous and days are only slices taken from that timeline for analytical purposes, let’s start with the morning period to see just how many pressures the family man faces and how they increase in number throughout the day. The first pressure relates to waking up at a certain time. In the winter months this is most difficult, for as soon as you emerge from underneath the warm covers, you are welcomed with colder air. As the sleeping man is in a vulnerable condition, with the vitality of the living spirit having rested for the previous eight or so hours, the sudden burst of cold is rather uncomfortable. As over time the difference in climatic conditions comes to be expected, the waking man knows what he will face should he arise, so just getting out of bed becomes a chore.
winterEmerging from bed is the start of the day. Now you have to do your routine in the bathroom, change clothes, preferably eat something, and make it out the door within a short amount of time so that you can arrive at work on time. In some cases, there may be the added step of checking email. If something went wrong overnight at work, you’ll have to fix it before you leave the house. Fixing the problem will only make you later, and thus cause you to get behind on the day’s work.
Then there is the pressure of the travel. If you take mass transit, you want to make the train or bus that you prefer to take. The public transportation vehicle must arrive on time as well; otherwise the delicate balance of time management is thrown off. For the person who drives to work, you just hope that there is no traffic on the roads. By the way, since you’re taking an automobile to work every day, you are now responsible for its maintenance. This means always keeping in mind how much gasoline is in the car and whether or not you need to bring the vehicle in for servicing. The service centers are typically only open during the weekdays, those days where you have the aforementioned morning pressures relating to work. Should the car require maintenance, you have to rearrange your schedule and hope that the repairs don’t cost too much.
If you do arrive at work on time, other kinds of pressures only begin. The difficulty of the job is what enables you to earn a living off of what you do. As in the modern age most of society doesn’t live off of farming, income is earned by being of some value to an organization that sells a good or service to others. As the profit/loss game is volatile, there is no telling whether or not the company will survive going forward. It is funny to think that those who farm for a living are now considered poor and stuck in a “third world” life, while the society filled with daily pressures and uncertainty is considered advanced.
If you manage to work your eight hours, which is actually a lot of time, you now want to get home and relax. Your work day is over, but you know that you’ll have to repeat it again the next day. This actually introduces a new pressure, one which is again based on time. You have a limited window for enjoyment, so you want to make sure that nothing gets in the way of that. Ah, but the responsibilities at home never go away, even if you leave for your job. The spouse at home may want you to pick up something after you leave work. There are so many errands to run and things to do that you’re fortunate if you can ever just travel straight home.
The family members at home may not live the same life that you do. All the work you put in, all the pressure you deal with, is for their benefit, and yet they just keep asking for things. They want money for this and that, and they want to make sure that you’re always there. This adds another pressure. If somehow you were unable to provide for them, what would they do? In this way your focus shifts towards defense, protecting what you have now, though your present lifestyle is filled with constant pressure. Rather than look for a way out of the hectic struggle, you think of ways to maintain it, thus taxing your brain constantly. Even going to bed at night is stressful, for you know that if you don’t fall asleep at a specific time, you will have difficulty waking up and preparing for work in the morning.
With such stress on the mind, how is one supposed to learn about Brahman and realize that they are not spirit? Where does the devotional aspect of life fit into all of this? The stressed worker is one scenario, but what about the person suffering from a debilitating disease? Sure, we are not our body, but tell that to someone dying of cancer. If my body is filled with pain, how am I not supposed to think about it? Fortunately, there is one method of spiritual practice that can be implemented under any condition. Success through this avenue is not dependent on extenuating circumstances, though peace of mind is always helpful.
“One who is not in transcendental consciousness can have neither a controlled mind nor steady intelligence, without which there is no possibility of peace. And how can there be any happiness without peace?” (Lord Krishna, Bhagavad-gita, 2.66)
Lord KrishnaHow can any person find happiness without peace? This cogent rhetorical question is posed by Lord Krishna in the Bhagavad-gita, the most concise and complete treatise on spirituality known in the world. It is the only book that need be read, for within it are pearls of wisdom that form the most valuable necklace of knowledge. From the Gita we learn that knowing Brahman is just the beginning. As pure spirit, we have a constitutional position, one where we are intimately tied to the Supreme Spirit, who is none other than Shri Krishna.
Studying Brahman, practicing austerity, performing sacrifices and giving in charity are meant to culminate in Krishna consciousness. Bhakti-yoga, or devotional service, is the set of activities that seek that divine consciousness right from the start. In other methods, one first starts with fruitive activity, mental speculation, or meditation and then hopefully reaches the platform of devotion to God. With bhakti-yoga, the transcendentalist immediately touches Krishna, and though their behavior may be tainted in the beginning, simply through the sincere desire to connect with Krishna, success is assured, even under trying circumstances.
There are many historical examples to show evidence of the fact, but likely the most cherished and remembered is the story of Prahlada Maharaja. The family man has a ton of pressure to deal with, but imagine if your father kept harassing you, trying to kill you day after day. As an adult, maybe this wouldn’t be so difficult, but what if you were just five years old and your father the most feared king in the world? This is precisely what Prahlada Maharaja faced, who, as a five year old boy, was stubborn in his insistence on practicing bhakti. On the other hand, his father, Hiranyakashipu, was against any type of devotional practice. He was warm to the idea of his son getting an education, but only on those topics that would allow him to follow in the father’s footsteps. The ruthless king wanted Prahlada to be just as feared, to carry on the tradition of power and strength. Thus Prahlada was sent to school to learn the art of administration.
Yet the boy had no interest in these topics. He only wanted to hear about devotion to Vishnu, which is another name for God. The father would ask the son what he learned in school, and to his chagrin Prahlada would only speak of Vishnu. Hiranyakashipu hated this so much that he finally decided Prahlada had to be killed. One slight problem though. Prahlada was unbreakable. Throwing him in a pit of snakes, setting him on fire, tossing him off the cliff of a mountain, and even attacking him with deadly weapons could not kill him. Throughout these attacks, Prahlada just remembered Vishnu, vishno-smaranam.
“Prahlada Maharaja said: Hearing and chanting about the transcendental holy name, form, qualities, paraphernalia and pastimes of Lord Vishnu, remembering them, serving the lotus feet of the Lord, offering the Lord respectful worship with sixteen types of paraphernalia, offering prayers to the Lord, becoming His servant, considering the Lord one's best friend, and surrendering everything unto Him (in other words, serving Him with the body, mind and words) — these nine processes are accepted as pure devotional service.” (Shrimad Bhagavatam, 7.5.23-24)
Prahlada MaharajaFrom the interactions between the famous father-and-son pair we get the definition of bhakti-yoga. Divine love can consist of nine different activities, with the most important being hearing and chanting. From hearing about Krishna one gets the seed of the creeper of devotion implanted within them. Through continuous hearing that seed can start to grow. With chanting one can make sure that the connection to God remains intact. Just by regularly chanting, “Hare Krishna Hare Krishna, Krishna Krishna, Hare Hare, Hare Rama Hare Rama, Rama Rama, Hare Hare”, all that one desires in spiritual life will arrive in the palm of the hand. No other method need be attempted. No austerity, penance, meditation, study, or sacrifice can bring the same benefit as that which comes through dedication in chanting.
From this sacred sequence of words, which is known as the maha-mantra, we get the solution to the problem of how to find spiritual life while supporting a family. Surely there are many pressures facing the dedicated worker supporting so many dependents, but if there is a sincere desire to connect with Krishna, the Lord will provide the necessary help. In spite of so many responsibilities, if one can make the chanting of the holy names a priority that is attended to each day, God will take care of the rest.
The routine recommended by the Vaishnava acharyas, those who follow in the mood of devotion of Prahlada Maharaja, is that one chant the maha-mantra for sixteen rounds a day on a set of japa beads. This will take quite a bit of time each day, even after one becomes familiar with the pronunciation of the words and gains some speed in their chanting. At the same time, this recommendation doesn’t mean that one who only chants a single round each day isn’t spiritually benefitted. Rather, just one pure recitation of the holy name of Krishna is enough to bring immeasurable pious credits. The struggling worker can find time to chant at least one round per day. If a steady routine is made to support that dedication, then additional rounds can slowly be added on.
With Prahlada Maharaja there was full sincerity, and since he was only five years old what could he really do to influence his circumstances? Vishnu finally arrived on the scene as Narasimhadeva and took care of Hiranyakashipu. This means that for the sincere devotee, whatever impediments are there will be taken away. Prahlada didn’t give up being a king and then move to the forest. Instead, he lived within his environment and still remained always connected with Krishna. While waking up in the morning, driving to work, or even taking care of our tasks each day, there is nothing to stop vishno-smaranam. That remembrance of God is best strengthened through regular chanting, which is our ticket out of the hectic world lacking any semblance of peace.
In Closing:
Constant requests from family member each,
Leave constant pressures, peace out of reach.
Mind like donkey facing steady attack,
Can only handle so much load on back.
But devotion to flourish in any circumstance,
Every second to chant holy names brings chance.
Prahlada of his conditions had no control,
Yet to memory of Vishnu did he hold.
Krishna takes care of those who are sincere,
Through bhakti practice to God become dear.

Wednesday, December 14, 2011

Tireless research reveals secrets of the 'sleep hormone'



A team from the Research Institute of the McGill University Health Centre (RI-MUHC) and McGill University has made a major breakthrough by unraveling the inner workings of melatonin, also known as the "sleep hormone." The research, conducted in collaboration with scientists in Italy, reveals the key role played by the melatonin receptor in the brain that promotes deep, restorative sleep. This discovery led the researchers to develop a novel drug called UCM765, which selectively activates this receptor. The results, published in The Journal of Neuroscience, may pave the way for the development of new and promising treatments for insomnia, a common public health problem that affects millions of people worldwide.
"We've spent many years develop medications that act selectively on a single melatonin receptor to specifically promote deep sleep, which we believe is the key to curing insomnia," says Dr. Gabriella Gobbi, a researcher in psychiatry at the RI-MUHC and the study's principal investigator. "Deep sleep has significant restorative effects, as well as the ability to increase memory and boost metabolism, while lowering blood pressure and slowing the heart rate." To date most treatments for insomnia, such as benzodiazepines, have not been selective for deep sleep, and can lead to dependence and cognitive impairment.
The researchers became interested in melatonin because of its effect on cerebral activity, and its involvement in sleep, depression and anxiety. Melatonin is a critical hormone produced by the pineal gland (located in the brain) in the absence of light stimulation. This hormone, present throughout the animal kingdom, is responsible for regulating sleep and circadian rhythms.
The research team discovered that two principal melatonin receptors, known as MT1 and MT2, played opposite roles in sleep regulation. "We discovered that MT1 receptors act on rapid eye movement (REM) sleep and block non-REM sleep, while MT2 receptors favour non-REM sleep, also known as deep sleep," explains Dr. Gobbi, who is also an associate professor of psychiatry in the Faculty of Medicine at McGill. "Specifying the role of MT2 receptors in melatonin represent a major scientific breakthrough that may designate them as a promising novel target for future treatments of insomnia. This discovery also explains the modest hypnotic effect of the over-the-counter melatonin pills, which act on both conflicting receptors."
Using a drug called UCM765, developed in collaboration with a group of chemists, under the leadership of Professor Tarzia in Urbino and Professor Mor in Parma, Italy which selectively binds to the MT2 receptor, the researchers observed an increase in the phases of deep sleep in rats and mice. Most importantly, UCM765 acts in a brain area called the reticular thalamus, which is the main driver of deep sleep. "This new molecule, contrary to traditional treatments for insomnia, increases deep sleep without destroying the "architecture" of sleep. In other words, it increases the duration of deep sleep while keeping the REM sleep episodes the same," says Dr. Gobbi.
"The development of this pharmacology by means of targeting deep sleep receptors to treat insomnia represents a major advancement in our ability to deal with this common health problem that affects people worldwide," concludes Dr. Vassilios Papadopoulos, Director of the Research Institute of the MUHC.
More information: The Journal of Neuroscience: http://www.jneurosci.org/
Provided by McGill University Health Centre
"Tireless research reveals secrets of the 'sleep hormone'." December 13th, 2011. http://medicalxpress.com/news/2011-12-tireless-reveals-secrets-hormone.html
Posted by
Robert Karl Stonjek

Study provides potential explanation for mechanisms of associative memory



Researchers from the University of Bristol have discovered that a chemical compound in the brain can weaken the synaptic connections between neurons in a region of the brain important for the formation of long-term memories. The findings, published today in the Journal of Neuroscience, may also provide a potential explanation for the loss of memory associated with Alzheimer's.
Acetylcholine, a neurotransmitter, is released in the brain and is known to play an important role in normal brain functions such as sleep, attention, and learning and memory. Until now the mechanisms by which this transmitter controls such processes were not well understood.
The findings, led by researchers from the University's MRC Centre for Synaptic Plasticity in the School of Physiology and Pharmacology, highlight the mechanisms by which acetylcholine controls communication between neurons located in the prefrontal cortex and may help in understanding how higher cognitive processing is controlled in this important brain area.
Professor of Cellular Neuroscience, Zafar Bashir and his team have demonstrated how electrical stimulation of the prefrontal cortex leads to the release of acetylcholine from synaptic terminals and the subsequent weakening of synaptic connections between neurons.
When acetylcholine is released it binds to specific receptors and starts a molecular cascade which triggers physiological alterations in how prefrontal cortical neurons are 'wired' together. The findings suggest that the persistent weakening of synaptic connections between neurons induced by the endogenous release of acetylcholine in the prefrontal cortex may underlie the formation of new associative memories.
The authors speculate that the memory impairments associated with Alzheimer's dementia may result, in part, from a loss of synaptic plasticity in the prefrontal cortex related to the depletion of brain acetylcholine that occurs in the disease.
Dr Douglas Caruana, who carried out the experiments, said: "Disruptions in cholinergic signaling in the prefrontal cortex are known to affect how the brain encodes lasting associations between objects and places, and a depletion of brain acetylcholine levels in the cortex is a classic hallmark of Alzheimer's dementia'."
Professor Bashir added: "Acetylcholinesterase inhibitors are the most widely used medication to treat individuals with Alzheimer's dementia and the enhancement of synaptic plasticity by acetylcholinesterase inhibition that we now demonstrate may be a way in which these drugs provide clinical efficacy."
More information: The research, entitled 'Induction of activity-dependent LTD requires muscarinic receptor activation in medial prefrontal cortex' by Professor Zafar Bashir, Dr Clea Warburton and Dr Douglas Caruana is published in the Journal of Neuroscience.
Provided by University of Bristol
"Study provides potential explanation for mechanisms of associative memory." December 13th, 2011. http://medicalxpress.com/news/2011-12-potential-explanation-mechanisms-associative-memory.html
Posted by
Robert Karl Stonjek

Novel mechanism regulating stress identified





Neuroscience researchers from Tufts have demonstrated, for the first time, that the physiological response to stress depends on neurosteroids acting on specific receptors in the brain, and they have been able to block that response in mice. This breakthrough suggests that these critical receptors may be drug therapy targets for control of the stress-response pathway. This finding may pave the way for new approaches to manage a wide range of neurological disorders involving stress.
The stress-control pathway, more technically known as the Hypothalamus-Pituitary-Adrenal (HPA) axis, determines the levels of cortisol and other stress hormones in the human body. In addition to being implicated in the types of emotional and psychological stress that can lead to major depression, disorders of the stress-control pathway are also associated with obesity, premenstrual syndrome, postpartum depression, Cushing's syndrome (hypercortisolism) and diseases including epilepsy and osteoporosis.
"We have identified a novel mechanism regulating the body's response to stress by determining that neurosteroids are required to mount the physiological response to stress. Moreover, we were able to completely block the physiological response to stress as well as prevent stress-induced anxiety," said author Jamie Maguire, PhD, assistant professor in the department of neuroscience at Tufts University School of Medicine and a member of the Neuroscience and Pharmacology & Experimental Therapeutics program faculties at the Sackler School of Graduate Biomedical Sciences at Tufts.
Using the brain tissues of adult mice, the research team identified mechanisms controlling the activity of Corticotrophin Releasing Hormone (CRH) neurons involved in the control of the stress pathway. By monitoring the activity of CRH neurons following stress and measuring levels of corticosterone in the blood, they found that the production of stress hormones required the action of neurosteroids on specific receptors on CRH neurons.
Apart from the finding that stress causes a neurosteroid-induced increase in blood corticosterone levels, the researchers also found that blocking the synthesis of neurosteroids is sufficient to block the stress-induced elevations in corticosterone and prevent stress-induced, anxiety-like behavior in mice. Previous research had identified the presence of specialized CRH-nerve-cell receptors in the HPA axis, but the findings had been controversial because of limited studies showing any connection between these receptors and the regulation of the CRH nerve cells.
"We have found a definite role of neurosteroids on the receptors regulating CRH nerve cells and the stress response. The data suggest that these receptors may be novel targets for control of the stress-control pathway. Our next work will focus on modulating these receptors to treat disorders associated with stress, including epilepsy and depression-like behaviors," said Maguire.
The first author on the study is Jhimly Sarkar, PhD, formerly a postdoctoral associate in the neuroscience department at TUSM. Additional authors are Seth Wakefield, BS, a neuroscience graduate student at the Sackler School; Georgina MacKenzie, PhD, a postdoctoral associate in neuroscience at TUSM; and Stephen Moss, PhD, professor of neuroscience at TUSM and a member of the neuroscience program faculty at the Sackler School.
More information: Sarkar J, Wakefield S, MacKenzie G, Moss SJ, Maguire J. The Journal of Neuroscience. "Neurosteroidogenesis is required for the physiological response to stress: role of neurosteroid-sensitive GABAA receptors." Published December 14, 2011, doi:10.1523/JNEUROSCI.2560-11.2011
Provided by Tufts University
"Novel mechanism regulating stress identified." December 13th, 2011. http://medicalxpress.com/news/2011-12-mechanism-stress.html
Posted by
Robert Karl Stonjek

Tuesday, December 13, 2011

The perils of drunken walking



(Medical Xpress) -- Drinking and driving is a much-publicized, dangerous combination, but is walking after drinking any safer?
"No, alcohol impairs your physical ability, period," said trauma surgeon Dr. Thomas Esposito at Loyola University Health System in Maywood, Ill.
"Every movement ranging from driving a car to simply walking to the bathroom is compromised," Esposito said. "Alcohol impairs your judgment, reflexes and coordination. Alcohol is nothing more than a socially acceptable, over-the-counter stimulant/depressant and, especially during the holidays, alcohol is frequently abused."
A trauma surgeon for more than 25 years, Esposito has witnessed the tragic aftermath of drunken walking in his own work many times. "From July 2009 to June 2010, 105 people were treated at Loyola after being struck by cars. Fifty-five had their blood-alcohol content checked. Of those, 16 individuals, or 29 percent, were found to have had some level of alcohol in their system,” said Esposito, who is chief of the division of trauma, surgical critical care and burns in the Department of Surgery, Loyola University Chicago Stritch School of Medicine. “Thirteen individuals, or 24 percent, had blood-alcohol concentrations at or above .08 percent, the accepted level for intoxication."
In 2005, the journal Injury Prevention reported that New Year's Day is more deadly for pedestrians than any other day of the year. From 1986 to 2002, 410 pedestrians were killed on New Year's Day. Fifty-eight percent of those killed had high blood-alcohol concentrations (BAC).
Alcohol also plays a significant role in the deaths of pedestrians throughout the year, according to the Insurance Institute for Highway Safety. In 2008, 38 percent of fatally injured pedestrians 16 and older had blood-alcohol concentrations at or above 0.08 percent, which is the legal definition for impaired driving in Illinois. The percentage rose to 53 percent for deaths occurring between 9 p.m. and 6 a.m. Fourteen percent of pedestrian deaths involved drivers with blood-alcohol content at or above .08 percent.
"If they had been driving and were stopped by police, they would have been arrested for driving under the influence," Esposito said.
He added that those statistics don't take into account the people who suffer injuries in their homes from unintentional causes and violence after drinking.
"It's not just walking outside. We often see people who have been drinking that have fallen down the stairs or tripped at home and injured themselves. Others have unwisely chosen to 'get into it' with guns, knives, bottles and fists," Esposito said.
Loyola University Health System's hospital is the only Level 1 Trauma Center in Illinois – and one of a select group nationwide – to be verified by the American College of Surgeons. A complete array of medical, surgical and ancillary services is available through an interdisciplinary program that serves the total needs of injured adult or pediatric patients from prevention through rehabilitation, 24 hours a day. These services include hospital transport, emergency medicine, general surgery and its subspecialties — such as orthopaedics, neurosurgery and others — critical care, nursing and a multitude of others including social work, rehabilitation and nutrition.
The Burn & Shock Trauma Institute serves as the research arm of Loyola’s Burn and Trauma Centers investigating problems in post-injury immunosuppression, wound healing and nutritional support.  The multidisciplinary institute also supports an injury prevention program, which conducts community outreach activities.
If you drink and plan to walk on New Year's Eve, or any other day of the year, you have to take special care, Esposito said. Some tips:
Like Rudolph, be a beacon of light. "If planning on walking at night, don't wear dark clothing that can make it difficult for drivers to see you."
Stay out of the road. "Walk solely on the sidewalks and cross at designated crosswalks."
Enforce the buddy system. "It's a good idea to walk in a group, which is easier for drivers to spot, and try to walk with at least one person who has not been drinking, a designated chaperone or escort."
Give pedestrians a brake. "Drivers need to take extra care when in restaurant or bar districts, since intoxicated pedestrians have slower reflexes and can be unpredictable."
Be a good host. "People hosting parties in which alcohol is consumed have as much of an obligation to watch over their guests who are walking home as they do with those who may be driving."
Grab a Pillow, Not a Cab
"You have to be able to assess someone's perceived ability to safely get from one place to the other," Esposito said. "If their mode of transportation is a car, you do things to prevent them from driving, such as calling them a cab or finding them an unimpaired chauffeur. If that mode of transportation is their legs, then you either drive them – assuming you’re not impaired – or make them stay at home with you."
Even if a guest stays at your home, you should be aware that they could trip and fall down the stairs, Esposito said. "So you don’t want to send them up to the second-story bedroom or down to the basement sofa."
Provided by Loyola University Health System
"The perils of drunken walking." December 9th, 2011. http://medicalxpress.com/news/2011-12-perils-drunken.html
Posted by
Robert Karl Stonjek

Survival of the fittest: Linguistic evolution in practice



A new study of how compound word formation is influenced by subtle forms of linguistic pressure demonstrates that words which "sound better" to the speakers of a language have a higher chance of being created, suggesting that, like biological organisms, words are subject to selection pressures that play a role in deciding which words become part of a language over time.
The study, "Grammars leak: Modeling how phonotactic generalizations interact within the grammar," to be published in the December 2011 issue of the scholarly journal Language, is authored by Andrew Martin, of the Laboratory for Language Development at the RIKEN Brain Science Center in Wako, Japan.
Different languages are marked by the different restrictions they place on which sounds are permitted to occur in words. In English, for example, long consonants are not allowed within single morphemes (units of meaning), but they are permitted in compound words like bookcase, where two identical consonants are located next to each other across the boundary between the two morphemes. Compare the pronunciation of the /p/ in car pool versus carp pool—the two compound words differ only in the length with which the /p/ is held.
Before now, the rules in English that govern long consonants have been stated simply: they are forbidden within morphemes, but if a long consonant is created by combining two words to form a compound, then it's allowed. "In my paper, however, I present evidence from a corpus of written English that things are not so neat—in fact, when English speakers create compounds, they tend to avoid creating compounds like bookcase that contain long consonants, even though these words are permitted by the rules of English" Dr. Martin commented. One implication of these findings is that the sounds in a word can subtly bias the choices people make about whether or not to create that word, or use it once created, ultimately influencing which words "catch on" and which die out.
This research also tells us something about how the rules within a language are interrelated. It would be simple to build a computer, for example, that could learn that long consonants are forbidden in one context, and completely acceptable in another context. Humans don't seem to work this way, though—when they learn that something is forbidden in one context, they can't help but think that the same thing doesn't sound very good even in a completely different context. This connectivity must be taken into account when building models of how people learn and store the rules of their language.
More information: A preprint version is available on line at: http://lsadc.org/info/documents/2011/press-releases/martin.pdf
Provided by Linguistic Society of America
"Survival of the fittest: Linguistic evolution in practice." December 9th, 2011. http://www.physorg.com/news/2011-12-survival-fittest-linguistic-evolution.html
Posted by
Robert Karl Stonjek

Matters of Taste continued


Compounds we perceive as sweet or bitter in the mouth trigger similar receptors and signaling pathways elsewhere in the body, helping to regulate digestion, respiration, and other systems.

By Thomas E. Finger and Sue C. Kinnamon | 
Shift Foto / CorbisShift Foto / Corbis
In the choice of what to ingest, the sense of taste is both a guardian and a guide. The sensations of bitter and sour keep us from eating potentially toxic substances and strong acids, while the preferred qualities of sweet, umami (the “savory” taste of glutamate), and salty drive intake of carbohydrates, amino acids, and sodium, respectively. Taste sensations are mediated by taste buds—small clusters of specialized epithelial cells on the tongue, soft palate, and larynx. Over the last two decades, as scientists have uncovered the array of G protein–coupled receptor (GPCR) cascades and ion channels that underlie taste signaling, they have also discovered, to their surprise, that the expression of these receptors and channels is not limited to taste buds. Indeed, elements of the taste transduction cascade occur in many chemoresponsive epithelial cells scattered throughout the stomach, the intestines, and even the airways. Despite the similarities in receptor molecules and signaling cascades, however, only the chemoreceptive systems in the mouth evoke a sensation of taste. The others, researchers are learning, serve different functions depending on their location.

The taste transduction story

The sensations of taste are divisible into five distinct qualities: salty, sour, bitter, sweet, and umami. Salty and sour sensory perceptions rely on ion channels, which are expressed in a variety of tissues, such as kidney, as well as in taste buds. Bitter, sweet, and umami qualities rely predominantly on two distinct families of GPCRs, Tas1R and Tas2R (T1R and T2R), first identified in taste tissues in 1999, but subsequently identified in other tissues, including gut and airway epithelia. Despite the difference in the qualities detected by the two families of taste receptors, both utilize similar, if not identical, downstream signaling effectors, including the taste receptor-associated G protein α-gustducin, one of the first identified proteins of a GPCR taste transduction cascade.
In 1996, researchers at the University of Würzburg reported that α-gustducin is expressed by brush cells of the stomach and intestine.1 Brush cells are tall, columnar epithelial cells that display a distinctive tuft of stiff microvilli at their apex. Based on morphological features, researchers had suspected that these cells were chemosensory, but the findings of gustducin, taste receptors,2 and the ion channel TrpM5, another taste transduction element,3 confirmed this early speculation, and suggested that brush cells detect nutrients in the gut. In the last 15 years, researchers have uncovered more and more taste cascade elements throughout the digestive tract, and even in the airways, suggesting a widespread distribution of complete taste transduction cascades—from taste receptor to transduction channel.
These seemingly misplaced taste-like pathways do not, however, give rise to sensations of taste, though they appear to detect compounds known to elicit a taste response in the mouth. Instead, these compounds initiate the taste transduction cascade with the end result of inducing particular physiological changes. For example, the pancreatic release of insulin in response to glucose is partially mediated by the binding of glucose to sweet-taste receptors on cells of the intestine and subsequent activation of the signaling cascade.4 Similarly, accidental inhalation of a beverage into the airways triggers taste receptors there, but rather than evoking a sensation of taste, the substance is irritating and provokes choking or coughing. (Although we use the phrases “taste transduction” and “taste receptors” below, we do not mean to imply that these equate to a perception of taste.)
Indeed, for every taste transduction cascade discovered outside the oral cavity, researchers seek to uncover the functional significance of the chemoresponsive cells in those areas. Taken together, the findings suggest that the taste transduction cascade is not restricted to the sensation of taste per se, or even to systems regulating food intake. In fact, the receptors mediating taste transduction appear to have evolved early in the vertebrate lineage, and to have since been widely adopted as a chemodetection system in a variety of organ systems.

“Taste” in the gut

In taste buds, receptors of the T1R family combine to form either a sweet receptor (T1R2 + T1R3) or an umami receptor (T1R1 + T1R3), and signal the presence of macronutrients necessary for survival: a carbohydrate energy source or amino acids, respectively. In the gut, the presence of sweet substances is detected by hormone-producing cells known as enteroendocrine cells that respond by secreting the glucagon-like peptide GLP-1, which in turn stimulates the release of insulin from pancreatic β-cells. The presence of circulating insulin results in the uptake of glucose from the bloodstream by diverse tissues. In addition, activation of the sweet receptors in the gut drives the insertion of the glucose transporters SGLT-1 and GLUT2 into the membranes of cells lining the intestines, thereby facilitating uptake of glucose.5,6
While the presence of T1R-class receptors for macronutrients in the gut is an obvious means to regulate digestive functions, the function of widespread T2R bitter receptors throughout the GI tract is less clear. Researchers have shown in vitro that activation of T2R receptors in an enteroendocrine cell line results in release of the peptide hormone cholecystokinin (CCK), which can reduce gut motility. Thus, intake of a potential toxin that activates the T2R pathway should decrease the rate at which food passes through the stomach and lower the drive for continued eating.7 Nonetheless, a recent study suggests that the lowered gut motility following intake of bitter substances is not dependent on T2R signaling, nor on CCK, leading researchers to reconsider the function of the receptors in this context.8
One possibility is that the CCK-secreting enteroendocrine cells are involved in a local epithelial signaling system that reduces transfer of toxic substances from gut into circulation. The CCK released from T2R-expressing enteroendocrine cells in response to stimulation by some bitter-tasting ligands may act on CCK2 receptors located on nearby intestinal epithelial cells, called enterocytes, which regulate the absorption of molecules from the intestinal lumen into the bloodstream.9 In vitro studies show that activating CCK2 receptors on these cells increases expression of the transporter ABCB1, which pumps out toxins or unwanted substances from the cytoplasm, allowing the toxins to be excreted rather than absorbed into the blood. Thus, activation of T2R signaling in the intestines indirectly results in increased elimination of absorbed toxins from gut epithelium before the toxins can enter circulation.
Lower in the gut, activation of T2R receptors similarly appears to combat toxins, though via a different mechanism. When some bitter-tasting ligands bind to epithelial cells in the colon, they induce the secretion of anions, which leads to fluid secretion into the intestine.10 This induced efflux of fluids is likely to flush out any noxious irritant from the colon, resulting in diarrhea.

“Taste” in the airways

Three years after taste-related signaling components were discovered in the gut, Zancanaro and colleagues at the University of Verona described the presence of gustducin-expressing cells in the airway. Specifically, the researchers examined mice and identified gustducin-expressing cells scattered in the epithelium lining the incoming ducts of the vomeronasal organ, a specialized part of the olfactory system found in many vertebrates, but not in adult humans. Such cells were also identified in the nasal respiratory epithelium. The morphology of these cells is similar to chemosensory cells scattered within the epidermis of fishes, first described by Mary Whitear in the 1970s. In a series of elegant ultrastructural studies, she identified a distinctive type of epithelial cell that extends through the height of the epithelium with microvillous extensions at its apical end. Since these cells also form extensive synapses at their base with local nerve fibers, Whitear suggested they must be a sensory cell type. Furthermore, since the apical specializations were not rigid, she deduced that the cells could not be mechanosensory, and therefore were likely chemosensory elements. Later, two physiological studies on fish with specialized appendages rich in solitary chemosensory cells confirmed the chemoresponsiveness of this system, although the identity of the natural stimulus remains controversial.
Subsequently, we and others showed that morphologically and molecularly similar solitary chemosensory cells (SCCs) are present throughout the upper respiratory systems of alligators, mice, and rats; and in the rodents, the cells express the entire panoply of taste-related signaling molecules, including T2R receptors, gustducin, PLCb2, and the transduction channel TrpM5.3,11 In 2003, we confirmed that the taste signaling cascade is necessary for activation of the SCCs of the nasal cavity.11 These SCCs synapse onto polymodal pain fibers of the trigeminal nerve, which produce a sensation of irritation and pain when activated. In addition, activation of these fibers evokes protective airway reflexes such as apnea (to prevent further inhalation) and sneezing (to remove the irritant). Thus, inhalation of a toxin that activates T2R receptors will be irritating and will provoke changes in respiration,12 but will not, of course, produce the sensation of a bitter taste.
More recently, we showed that even some bacterial metabolites and signal molecules can activate the nasal SCCs and the trigeminal nerve.12 Upon activation, the trigeminal nerve fibers not only transmit the information towards the brain, but also release peptide modulators (such as substance P and calcitonin gene-related peptide) into the local tissue, including around nearby blood vessels. These modulators bind to receptors on mast cells and blood vessels, causing a local, neurally mediated inflammation of the airway lining. In this way, SCCs not only act as sentinels warning against inhalation of irritants, but also serve as guardians capable of activating the innate immune system to respond to the presence of potentially damaging toxins or pathogens.
In all of the examples described so far, the taste signaling cascade is used to detect molecules in the lumen of an organ (oral cavity, gut, respiratory passages), and to generate an intracellular cascade to effect release of a neurotransmitter or hormone to signal to other cells in the body. Two recent reports on the expression of taste receptors in the airways indicate that taste-receptor signaling may directly affect the function of the cell that actually detects the stimulus (i.e., a cell-autonomous effect). Last year, Deshpande and colleagues reported that human airway smooth muscle cells express T2R (bitter) taste receptors along with α-gustducin and some components of the taste-associated phospholipase C (PLC) arm of the signaling cascade.13 Application of various bitter-tasting substances to cultured human airway smooth muscle cells shows the same PLC-dependent increases in intracellular Ca2+ typical of taste cells or solitary chemosensory cells. Surprisingly, however, these increases in intracellular Ca2+ caused relaxation, rather than contraction, of the muscle cells. This paradoxical effect is attributed to the proximity of the T2R receptor complex to calcium-activated potassium channels (BKCa channels), which open in response to increased intracellular Ca2+, causing the hyperpolarization and subsequent relaxation of the muscle cells. In contrast, in taste cells of the mouth and solitary chemosensory cells of the upper airways, the increase in intracellular Ca2+ as a result of T2R activation triggers the transduction channel TrpM5 to depolarize the cell and evoke transmitter release to stimulate other cells. Thus, in different signaling contexts, activation of the same receptor can produce opposite cellular-level effects. However, two recent letters to the editor call Deshpande’s results into question, so the resolution of this remains controversial.
T2R activation has also been reported to have a cell-autonomous effect in ciliated cells of human lower airways.14 Cultured human airway epithelium expresses some T2Rs along with associated downstream elements. Curiously, these are the first cells with motile cilia known to express sensory signaling elements. In these cells, the T2Rs are present on the cilia, while PLCb2 is associated with the cell membrane where the cilia insert into the cell body. Binding of the T2R receptor by a bitter ligand initiates a transduction cascade to activate PLCb2 at the base of the cilium, generating a Ca2+ response. The resulting T2R-mediated increase in intracellular Ca2+ causes an increase in ciliary beat frequency, which the researchers suggest could serve to sweep irritants away from the surface of the cell. But while T2Rs can be detected in cultured human airway cells, they are not detected in the lower airways of mice.12 Whether this represents a species difference or the difference between in vivo and in vitro states remains to be determined.

Remaining taste mysteries

It is evident that taste receptors and their associated downstream signaling components are widely dispersed in diverse organ systems, and in many cases serve to help with digestion or to protect cells from potential toxins. But taste receptors have also been identified in other organs and tissues, such as the bile ducts, where their functions are still unclear. The composition of the fluid in the bile ducts is dictated by secretions of the pancreas, liver, and gall bladder. Why should it be necessary to diligently monitor the composition of biliary fluids as they move from gall bladder to intestine?
Similarly enigmatic are the reported effects of T2R (bitter receptor) agonists on contractile elements of both the airway and the gut. In the trachea, T2R agonists cause muscle relaxation (see above), but it is not clear how a bitter substance would have access to the smooth muscle cells of the trachea under normal conditions. The smooth muscle of the trachea is buried beneath a relatively tight airway epithelium, and so it seems unlikely that an inhaled bitter substance would penetrate the epithelium to access T2R receptors on the muscle. Similarly, the inhibition of smooth muscle contractility by T2R agonists in the stomach is not mediated by any of the peptides released by dispersed endocrine (enteroendocrine) cells of the gut, and may not even be mediated by T2R receptors. These and other nonspecific effects of bitter ligands emphasize the need to utilize either well-defined pharmacological agents or, better still, knockout animals to establish the specificity of receptors and transduction pathways and the consequences of their activation. Though they may not be for tasting per se, the taste-family receptors are surely doing something to affect the physiology of the organs in which they reside.
Thomas E. Finger is a professor of Cellular & Developmental Biology at the University of Colorado Medical School and codirector of the Rocky Mountain Taste & Smell Center. Sue C. Kinnamon is a professor of Otolaryngology at the University of Colorado Medical School and a core director of the Rocky Mountain Taste & Smell Center. 

 

 

 

 

References

  1. D. Höfer et al., “Taste receptor-like cells in the rat gut identified by expression of alpha-gustducin,” PNAS, 93:6631-34, 1996.
  2. S.V. Wu et al., “Expression of bitter taste receptors of the T2R family in the gastrointestinal tract and enteroendocrine STC-1 cells,” PNAS, 99:2392-97, 2002.
  3. S. Kaske et al., “TRPM5, a taste-signaling transient receptor potential ion-channel, is a ubiquitous signaling component in chemosensory cells,” BMC Neurosci, 8:49, 2007.
  4. H.J. Jang et al., “Gut-expressed gustducin and taste receptors regulate secretion of glucagon-like peptide-1,” PNAS, 104:15069-74, 2007.
  5. O.J. Mace et al., “Sweet taste receptors in rat small intestine stimulate glucose absorption through apical GLUT2,” J Physiol, 582:379-92, 2007.
  6. R.F. Margolskee et al., “T1R3 and gustducin in gut sense sugars to regulate expression of Na+-glucose cotransporter 1,” PNAS, 104:15075-80, 2007.
  7. J.I. Glendinning et al., “Intragastric infusion of denatonium conditions flavor aversions and delays gastric emptying in rodents,” Physiol Behav, 93:757-65, 2008.
  8. S. Janssen et al., “Bitter taste receptors and α-gustducin regulate the secretion of ghrelin with functional effects on food intake and gastric emptying,” PNAS, 108:2094-99, 2011.
  9. T.I. Jeon et al., “Gut bitter taste receptor signaling induces ABCB1 through a mechanism involving CCK,” Biochem J, 438:33-37, 2011.
  10. I. Kaji et al. “Secretory effects of a luminal bitter tastant and expressions of bitter taste receptors, T2Rs, in the human and rat large intestine,” Am J Physiol Gastrointest Liver Physiol, 296:G971-81, 2009.
  11. T. E. Finger et al., “Solitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration,” PNAS, 100:8981-86, 2003.
  12. M. Tizzano et al., “Nasal chemosensory cells use bitter taste signaling to detect irritants and bacterial signals,” PNAS, 107:3210-15, 2010.
  13. D.A. Deshpande et al., “Bitter taste receptors on airway smooth muscle bronchodilate by localized calcium signaling and reverse obstruction,” Nat Med, 16:1299-304, 2010.
  14. A. S. Shah et al., “Motile cilia of human airway epithelia are chemosensory,” Science, 325:1131-34, 2009.
 
Posted by
Robert Karl Stonjek

Human Hearts Beat Together

ScienceShot: Human Hearts Beat Together

by Meghan Rosen 
 
sn-humanhearts.jpgCredit: Benjamin Rosen

It's not always easy to follow your heart. But for human babies and their mothers, following each other's hearts may be as simple as sharing a smile. A new study shows that 3-month-old infants and their mothers can synchronize their heartbeats to mere milliseconds. Researchers sat 40 pairs of mothers and infants face-to-face, equipped with sticky skin electrodes on either side of their hearts. Beat for beat, mother-and-child hearts thumped together almost instantly as they shared loving looks or contented coos. This cardiac coupling worked only for moms with their own babies, and only when the duos synchronized smiles and other cheerful social behaviors, researchers report in this month's issue of Infant Behavior and Development. When humans mirror each other's facial expressions, they may switch on specific areas in the brain that tell the heart when to thump, the researchers suspect. Melding with mom lasts longer than just a few beats, however. Babies who don't tune in with their mothers are less empathetic as teenagers, according to previous work from the same lab. Premature infants or those whose mothers have postpartum depression may be most at risk for losing this social skill because they miss out on early opportunities to interact with mom.
Comment:
I would have thought that the baby's heart beats much faster than the mother's?
Posted by
Robert Karl Stonjek

'Vocal Fry' Creeping Into U.S. Speech


by Marissa Fessenden
 
sn-vocalfry.jpgFry and fry again. College-age women end sentences in the lowest vocal register, a creaky vibration called vocal fry, possibly to broadcast themselves as part of a social group.
Credit: Yaymicro.com/MonkeyBusiness
A curious vocal pattern has crept into the speech of young adult women who speak American English: low, creaky vibrations, also called vocal fry. Pop singers, such as Britney Spears, slip vocal fry into their music as a way to reach low notes and add style. Now, a new study of young women in New York state shows that the same guttural vibration—once considered a speech disorder—has become a language fad.
Vocal fry, or glottalization, is a low, staccato vibration during speech, produced by a slow fluttering of the vocal cords (listen here). Since the 1960s, vocal fry has been recognized as the lowest of the three vocal registers, which also include falsetto and modal—the usual speaking register. Speakers creak differently according to their gender, although whether it is more common in males or females varies among languages. In American English, anecdotal reports suggest that the behavior is much more common in women. (In British English, the pattern is the opposite.) Historically, continual use of vocal fry was classified as part of a voice disorder that was believed to lead to vocal cord damage. However, in recent years, researchers have noted occasional use of the creak in speakers with normal voice quality.
In the new study, scientists at Long Island University (LIU) in Brookville, New York, investigated the prevalence of vocal fry in college-age women. The team recorded sentences read by 34 female speakers. Two speech-language pathologists trained to identify voice disorders evaluated the speech samples. They marked the presence or absence of vocal fry by listening to each speaker's pitch and two qualities called jitter and shimmer—variation in pitch and volume, respectively.
More than two-thirds of the research subjects used vocal fry during their readings, the researchers will report in a future issue of the Journal of Voice. The distinct vibrations weren't continuous. Rather, they arose most often at the ends of sentences. The patterns were "normal" variations, says co-author and speech scientist Nassima Abdelli-Beruh of LIU, because the women rarely slipped into vocal fry during sustained vowel tests—prolonged holding of vowels such as 'aaa' and 'ooo'—a classic way to assess voice quality and probe for possible disorders. Abdelli-Beruh says the creak is unlikely to damage vocal cords because speakers didn't creak continuously or even at the end of every sentence.
The study is the first to quantify the prevalence of vocal fry in normal speech, although other researchers have noted the pattern. The group is also the first to verify that American women are much more likely to exhibit the behavior than men, as its yet-unpublished data show that male college-age students don't use the creaky voice. The team's next steps will attempt to find out when this habit started—and if it is indeed a budding trend.
The researchers also plan to test students in high schools and middle schools to learn why young women creak when they speak. "Young students tend to use it when they get together," Abdelli-Beruh says. "Maybe this is a social link between members of a group."
Abdelli-Beruh also wants to compare the prevalence of vocal fry on radio stations. For example, she says that the popular-music station on her teenage son's dial features creaky announcers, but she does not hear vocal fry on National Public Radio, which targets an older audience.
Linguist Patricia Keating of the University of California, Los Angeles, agrees with Abdelli-Beruh's statement that creaking at the end of a sentence is normal for many speakers. "There are languages that use creak as part of the phonemic system," she says. "The chances of it leading to vocal damage are very minimal."
The small number of subjects and the limited geographic focus of the study make these findings very specific, Keating says. But she notes that speech researchers suspect the vibrational trend is widespread in the United States. "I think there are generational differences," she says. "But it is common to mark the end of sentences [with vocal fry]. If the pitch falls, you get creak."
Source: Science
http://news.sciencemag.org/sciencenow/2011/12/vocal-fry-creeping-into-us-speec.html?ref=em&elq=4aedbf9ce7b94cb9b342caea1436ed28
Posted by
Robert Karl Stonjek

SAI SAI - SHIRDI SAI BABA

Should developing countries shift from focusing on improving schools to improving parents?




I travel to many developing countries in the context of my work for The World Bank. I visit schools that receive financial support and technical assistance from the Bank to improve the learning experiences and outcomes of students. Each time, I ask teachers in these schools what they think would make the biggest difference in the learning outcomes of their students. The most common answer is “better parents.” I often wonder if this response is, in some conscious or unconscious way, an excuse to help teachers explain the poor outcomes of their students (especially those from the poorest households) and their low expectations of what their students can achieve. However, both common sense and solid research indicate that parents matter.

A new OECD study using PISA data highlights the important role of parents in the learning outcomes of students, and it has received broad attention from opinion makers (see Friedman's editorial in the Sunday edition of the NYT).  The researchers look into more than the widely documented impact of parental (especially mother's) education level and explore specific parental behaviors. They find that some types of parental involvement are more conducive to stronger learning outcomes in high school – for example, reading to young children and asking them about their school day, is related to higher learning outcomes (as measured by PISA test scores), but volunteering at school or participating in the PTA are not.

But what does this mean for policy makers? What does this imply for World Bank staff and others advising policy makers around the world? In my view, we need to do more from the school-side to counterbalance the role of parents. Because children do not choose their parental quality, in most societies the most disadvantaged children in terms of the households in which they live (poverty, low parental education, low parental involvement) also end up in the most under- resourced (both in material and human terms) schools.

Schools around the world continue to be life changing institutions. But in most countries, more needs to be done to attract the best into the teaching profession, prepare them with useful training and experience, monitor and support their work, and motivate them by rewarding excellent teachers. At the Bank, in the SABER-Teachers project, we are working hard to build new knowledge on what are the most effective policies to ensure that all children have access to great teachers. We are collecting data on the policies of a majority of education systems across the globe, and assessing their progress towards achieving 8 core teacher policy goals (setting clear expectations, attracting the best into teaching, preparing teachers with useful training and experience, matching teachers’ skills with students’ needs, leading teachers with strong principals, monitoring teaching and learning, supporting teachers to improve, and motivating teachers to perform).

We know that few societies do this particularly well, and children around the world continue to have unequal opportunities to learn and succeed in life. Affecting the quality of parents is important and is a much more difficult task than to achieve large scale improvement in the quality of teaching and learning in schools. While the latter is also unquestionably very challenging, countries like Finland, South Korea, Singapore and Poland have shown that it is feasible to achieve this within a generation.

Females choose sexier friends to avoid harassment


Scientists have observed a strategy for females to avoid unwanted male attention: choosing more attractive friends. Published 7 December in the journal Proceedings of the Royal Society B, the study is the first to show females spending time with those more sexually attractive than themselves to reduce harassment from males.
Carried out by the Universities of Exeter and Copenhagen, the study focuses on the Trinidadian guppy, a species of small freshwater fish. It shows that the females choose companions that are relatively more attractive than themselves and in this way reduce harassment from males. The research shows that the tactic is successful and by ensuring they are less attractive than other group members, the fish experience less harassment and fewer mating attempts from males.
Male guppies are well known for frequent and sometimes constant harassment of females. This puts a significant burden on females, sometimes preventing them finding food and escaping from predators.

Tropical disease experts report missed opportunity to transform global HIV/AIDS fight


Global HIV/AIDS prevention and treatment efforts are missing a major opportunity to significantly improve health conditions in poor countries by simply adding low-cost care for the many other chronic and disabling diseases routinely afflicting and often killing these same patients, according to a panel of disease experts who spoke at the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH). “People want better health; they do not understand why we silo diseases,” said Judd Walson, a global health and infectious disease expert at the University of Washington. “If you die from malaria, you don’t care that your HIV was treated. Communities want us to leverage the resources we have to treat and prevent disease as effectively as possible.”
Walson and his colleagues on the panel noted that many victims of HIV/AIDS also typically suffer from one or more of about 17 neglected, but burdensome, tropical diseases often called “diseases of poverty” because they prey on the “bottom billion”—the world’s poorest people. They include ailments such as trachoma, schistosomiasis, lymphatic filariasis, leishmaniasis, Chagas disease and onchocerciasis, all of which are either insect-borne disease, bacterial infections, or caused by parasitic worms. Continue reading below…