Magnetic stimulation to improve visual perception

(Medical Xpress) -- Using transcranial magnetic stimulation (TMS), an international team led by French researchers from the Centre de Recherche de l'Institut du Cerveau (CNRS) has succeeded in enhancing the visual abilities of a group of healthy subjects. Following stimulation of an area of the brain's right hemisphere involved in perceptual awareness and in orienting spatial attention, the subjects appeared more likely to perceive a target appearing on a screen. This work, published in the journal PLoS ONE, could lead to the development of novel rehabilitation techniques for certain visual disorders. In addition, it could help improve the performance of individuals whose tasks require very high precision.

TMS is a non-invasive technique that consists in sending a magnetic pulse into a given area of the brain. This results in an activation of the cortical neurons located within the range of the magnetic field, which modifies their activity in a painless and temporary manner. For several years, scientists have been looking at the possibility of using this technique to enhance certain brain functions in healthy subjects.

In this respect, the team led by Antoni Valero-Cabré has carried out research involving the stimulation of a region of the right cerebral hemisphere known as the frontal eye field. Strictly speaking, this is not a primary visual area but it participates in the planning of ocular movements and the orientation of each individual's attention in the visual space. In a first experiment, a group of healthy subjects tried to distinguish a very low contrast target appearing on a screen for just 30 ms. In some of the tests, the subjects received a magnetic pulse lasting between 80 and 140 ms on this frontal region before the target appeared. The researchers found that the success rate was higher when using TMS. The visual sensitivity of healthy subjects was temporarily increased by around 12%. In a second experiment, the subjects were shown a fleeting visual cue indicating the spot where the target could appear. In this configuration, the enhancement of visual sensitivity, which remained of the same order, was only apparent when the cue indicated the correct location of the target.

Although cerebral functions such as conscious vision are highly optimized in healthy adults, these results show that there is a significant margin for improvement, which can be “enhanced” by TMS. This technique could be tested for the rehabilitation of patients suffering from cortical damage, due for example to a cardiovascular accident, and for that of patients with retinal disorders. The second experiment suggests that rehabilitation based on both TMS and visual cues could be more selective than the use of stimulation alone. The researchers want to further explore this possibility using repetitive TMS, which, in this case, could make it possible to obtain long-lasting modification of cerebral activity.

Furthermore, according to the researchers, TMS could be used in the near future to increase the attentional abilities of individuals performing tasks that require good visual skills.

More information: Manipulation of pre-target activity on the right Frontal Eye Field enhances conscious visual perception in humans. Lorena Chanes, Ana B. Chica, Romain Quentin, Antoni Valero-Cabré. PLoS ONE. 15 May 2012.

Provided by CNRS

"Magnetic stimulation to improve visual perception." June 5th, 2012. http://medicalxpress.com/news/2012-06-magnetic-visual-perception.html

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Robert Karl Stonjek

Telephone therapy retains more patients than face-to-face sessions and improves depression

Phoning it in is more effective than the therapist's couch when it comes to keeping patients in psychotherapy. New Northwestern Medicine research shows patients who had therapy sessions provided over the phone were more likely to complete 18 weeks of treatment than those who had face-to-face sessions.

The study, published in the June 6 issue of the Journal of the American Medical Association, is the first large trial to compare the benefits of face-to-face and telephone therapy. Phone therapy is a rapidly growing trend among therapists. About 85 percent of psychologists now deliver some of their services over the phone because competing demands, transportation time and other problems make it difficult for many patients to get to their offices.

"Now therapists can make house calls," said David Mohr, the lead author and a professor of preventive medicine at Northwestern University Feinberg School of Medicine.

"Our study found psychotherapy conveniently provided by telephone to patients wherever they are is effective and reduces dropout. This suggests these services now should be covered by insurance."

While telephone therapy was as effective as face-to-face sessions in reducing depression during treatment, the improvement ebbed slightly six months after treatment ended compared to face-to-face therapy.

The randomized control trial included 325 primary care patients with major depressive disorder. The results showed 20.9 percent of patients who had cognitive behavioral therapy over the phone dropped out compared to 32.7 percent for face-to-face therapy. Patients in both therapies showed equally good improvement in their depression when treatment ended. Six months after treatment ended, all patients remained much improved. However, patients who had the telephone therapy scored three points higher on a depression scale than those who had face-to-face sessions.

"The three point difference is of questionable clinical significance but it raises the question whether some individuals are at risk of worsening after treatment with telephone therapy compared to face-to-face," Mohr said.

It may be that the slight worsening seen in the telephone therapy after the end of treatment was because patients who had more mental health difficulties and who would have dropped out of face-to-face sessions were retained in telephone therapy, Mohr noted. Thus, this may not be a real finding.

"But we can't rule out the possibility that it may be true and there is something about face-to-face treatment that creates better results for some people," Mohr said. "The physical presence of the therapist may be therapeutic in a way that helps some patients maintain their improvement in mood. There may be a unique quality about the human contact that increases resilience and maintains the skills learned to manage depression after treatment has ended."

Mohr said he hopes the study results will encourage insurance providers including Medicare to reimburse telephone therapy sessions, which many companies currently don't cover.

"There is good reason to reimburse these sessions," Mohr said. "Many people can't get to a therapist's office, but they want to talk to someone. Telephone therapy is highly effective and offers a solution to people with depression who otherwise would be left out." This is particularly true for disabled people or those who live where care is unavailable, such as in rural areas, he noted.

Research shows people prefer talk therapy to antidepressant medication, but many quickly drop out of treatment or don't follow up on a referral from their primary care physicians, likely the result of obstacles that prevent them from getting to the therapist's office.

More information: JAMA. 2012;307[21]:2278-2285. 

Provided by Northwestern University

"Telephone therapy retains more patients than face-to-face sessions and improves depression." June 5th, 2012.http://medicalxpress.com/news/2012-06-therapy-retains-patients-face-to-face-sessions.html

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Robert Karl Stonjek

Restricted food intake a predictor of increased suicide attempts in Body Dysmorphic Disorder patients

Rhode Island Hospital and Auburn University researchers found a link between restrictive food intake, or excessive dieting, and an increase in suicide attempts in people with Body Dysmorphic Disorder (BDD). The study focused on the acquired capability of suicide, which is one component of Joiner's (2005) interpersonal-psychological theory of suicide and is comprised of physical pain tolerance and lowered fear of death. The paper is published in the journal Suicide and Life-Threatening Behavior, and is now available online in advance of print.

BDD is a common, often severe, and under-recognized body image disorder. People with BDD experience distressing or impairing preoccupations with perceived flaws in their appearance and are obsessed with the belief that something is wrong with how they look, when in reality they look normal. More than 75 percent of people with BDD feel life is not worth living or think about suicide in their lifetime, and approximately 25 percent have a history of a suicide attempt.

Authors Tracy K. Witte, Ph.D., of Auburn University, Elizabeth R. Didie, Ph.D., a psychologist in the department of psychiatry at Rhode Island Hospital, and Katharine A. Phillips, M.D., director of the Body Dysmorphic Disorder Program at Rhode Island Hospital examined the association of suicide attempts with physically painful BDD-related behaviors, including restrictive food intake, excessive exercise, BDD-related cosmetic surgery, compulsive skin picking, and physical self-mutilation.

The study found that BDD-related restrictive food intake was associated with more than double the number of suicide attempts, but was not associated with suicide ideation; and that those with a history of BDD-related excessive exercise had less than half the number of suicide attempts as those without such a history. The study also found that none of the other variables indicating exposure to painful and provocative experiences, such as BDD-related cosmetic surgery and compulsive skin picking, were significant predictors of suicide attempts.

Because restriction of food intake can be physically painful, the researchers theorize that a person who is capable of enduring the physical discomfort of caloric restriction may be more capable of enduring the physical discomfort required in order to inflict self-harm. They theorize that severe restriction of food intake that results in long-standing physical discomfort would predict capability for suicide, whereas more moderate dieting behaviors would have less of a relationship (if any).

"Significantly limiting food intake can be physically painful," Phillips said. "It goes against our natural instincts to feed our bodies and respond to the physical pain that comes with extreme hunger. The results of this study suggest the importance of assessing individuals with BDD for restrictive eating behaviors to identify suicide risk, even if they have not previously been diagnosed with an eating disorder."

The study included interviews with 200 individuals (68.5 percent women) between the ages of 14 and 64 who had a lifetime diagnosis of BDD. The main criterion variable was the participants' number of past suicide attempts, which ranged from 0 to 25 in the study group. Additionally, 78 percent of the study group had a history of suicide-related ideation. The study only included examination of suicide attempts, not deaths by suicide.

"While some of the other BDD-related behaviors may seem outwardly more painful – such as undergoing repeated cosmetic procedures, or compulsive skin picking, the level of pain associated with excessive dieting could significantly increase a person's pain tolerance," Didie said. "This study suggests that those who are capable of enduring such physical discomfort and pain from restrictive eating also may be capable of enduring the physical discomfort required to inflict self harm."

Provided by Lifespan

"Restricted food intake a predictor of increased suicide attempts in Body Dysmorphic Disorder patients." June 5th, 2012.http://medicalxpress.com/news/2012-06-restricted-food-intake-predictor-suicide.html

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Anxious girls' brains work harder

This electrode cap was worn by participants in a Michigan State University psychology study that suggests anxious girls' brains work harder than boys'. Credit: Michigan State University

In a discovery that could help in the identification and treatment of anxiety disorders, Michigan State University scientists say the brains of anxious girls work much harder than those of boys.

The finding stems from an experiment in which college students performed a relatively simple task while their brain activity was measured by an electrode cap. Only girls who identified themselves as particularly anxious or big worriers recorded high brain activity when they made mistakes during the task.

Jason Moser, lead investigator on the project, said the findings may ultimately help mental health professionals determine which girls may be prone to anxiety problems such as obsessive compulsive disorder or generalized anxiety disorder.

"This may help predict the development of anxiety issues later in life for girls," said Moser, assistant professor of psychology. "It's one more piece of the puzzle for us to figure out why women in general have more anxiety disorders."

The study, reported in the International Journal of Psychophysiology, is the first to measure the correlation between worrying and error-related brain responses in the sexes using a scientifically viable sample (79 female students, 70 males).

Participants were asked to identify the middle letter in a series of five-letter groups on a computer screen. Sometimes the middle letter was the same as the other four ("FFFFF") while sometimes it was different ("EEFEE"). Afterward they filled out questionnaires about how much they worry.

Although the worrisome female subjects performed about the same as the males on simple portions of the task, their brains had to work harder at it. Then, as the test became more difficult, the anxious females performed worse, suggesting worrying got in the way of completing the task, Moser said.

"Anxious girls' brains have to work harder to perform tasks because they have distracting thoughts and worries," Moser said. "As a result their brains are being kind of burned out by thinking so much, which might set them up for difficulties in school. We already know that anxious kids – and especially anxious girls – have a harder time in some academic subjects such as math."

Currently Moser and other MSU researchers are investigating whether estrogen, a hormone more common in women, may be to blame for the increased brain response. Estrogen is known to affect the release of dopamine, a neurotransmitter that plays a key role in learning and processing mistakes in the front part of the brain.

"This may end up reflecting hormone differences between men and women," Moser said.

In addition to traditional therapies for anxiety, Moser said other ways to potentially reduce worry and improve focus include journaling – or "writing your worries down in a journal rather than letting them stick in your head" – and doing "brain games" designed to improve memory and concentration.

Provided by Michigan State University

"Anxious girls' brains work harder." June 5th, 2012. http://medicalxpress.com/news/2012-06-anxious-girls-brains-harder.html

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Robert Karl Stonjek

‎#### BABASAHEB DR. AMBEDKAR on Gandhi and Jinnah ####

‎#### BABASAHEB DR. AMBEDKAR on Gandhi and Jinnah #### I can give only my impressions of them, for what they are worth. The first thing that strikes me is that it would be difficult to find two persons who would rival them for their colossal egotism, to whom personal ascendancy is everything and the cause of the country a mere counter on the table. They have made Indian politics a matter of personal feud. Consequences have no terror for them ; indeed they do not occur to them until they happen. When they do happen they either forget the cause, or if they remember it, they overlook it with a complacency which saves them from any remorse. They choose to stand on a pedestal of splendid isolation. They wall themselves off from their equals. They prefer to open themselves to their inferiors. They are very unhappy at and impatient of criticism, but are very happy to be fawned upon by flunkeys. Both have developed a wonderful stagecraft and arrange things in such a way that they are always in the limelight wherever they go. Each of course claims to be supreme. If supremacy was their only claim, it would be a small wonder. In addition to supremacy each claims infallibility for himself. Pius IX during whose sacred regime as Pope the issue of infallibility was raging said— ” Before I was Pope I believed in Papal infallibility, now I feel it.” This is exactly the attitude of the two leaders whom Providence—may I say in his unguarded moments—has appointed to lead us. source: SECTION VIII, Ranade, Gandhi and Jinnah. Vol-I, Dr. Babasaheb Ambedkar Writing and Speeches

Chinese Beauty Art Paintings

Though Chinese painting has much in common with western painting from an aesthetic point of view, it still possesses its unique character. Chinese traditional painting seldom follows the convention of central focus perspective or realistic portrayal, but gives the painter freedom on artistic conception, structural composition and method of expression so as to better express his subjective feelings. Chinese painting has absorbed the best of many forms of art, like poetry, calligraphy, and seal engraving.

Take Mr. Qi Baishi (1863-1957), a great painter for example. Mr. Qi was a skillful poet, calligrapher and seal-cutter. Qi, a native of Hunan Province, injected his ink painting with typical Chinese farmers' tastes -- simple, pure, and humorous. All this made him an artistic giant of the 20th Century.

Chinese often consider a good painting a good poem, and vice versa. Hence we often say there is painting in poetry and poetry in painting. In the past, many great artists were also great poets and the calligraphers. The inscriptions and seal on the paintings not only can help us to understand the painter's ideas and emotions, but also provide decorative beauty to the painting.

Pines, bamboo and plum blossoms are 'bosom friends in winter.' The three plants are upright and show rectitude. They become favorite objects for Chinese painters. Chinese painting is a combination in the same picture of the arts of poetry, calligraphy, painting and seal engraving. They were indispensable elements, which supplement and enrich each other in contributing to the beauty of the whole picture.

Chinese paintings can be divided into four categories according to its format: murals, screens, scrolls, and albums and fans. In addition, they are frequently mounted against exquisite backgrounds to enhance their aesthetic effect.

In terms of technique, Chinese painting can be divided into two broad categories: paintings minutely executed in a realistic style and those that employ freehand brushwork.

Classified according to subject matter, they can be divided into paintings of figures, landscapes, buildings, flowers, birds, animals, insects and fish. The brush techniques so much emphasized in Chinese painting include line and texture (cunfa), the dotting method (dianfa) and the application of color (ranfa).

It is very difficult, if not impossible, to appreciate Chinese paintings without a profound knowledge about different styles characteristic of the different historical periods.

During the Tang Dynasty (618-907 AD), the culture flourished with the economic development. Painting was elegant in style, reflecting the general prosperity of the golden age of Chinese feudal society. The paintings of Song Dynasty (960-1279AD), however, favored abstract, implied meanings rather than direct expressions, painting skills matured considerably, and the realistic style was in full blossom. The Yuan Dynasty (1271-1368 AD) witnessed the flourish of the expressionist school and many painters indulged in painting solely for personal pleasure. The painters of Ming (1368-1644) and Qing (1644-1911) took painting as a vehicle to express their interests and feelings. They painted with a vigorous boldness, caring little for meticulous refinement. Gradually, Chinese painting became artistically 'perfect' during the Qing Dynasty.

However, 'perfection' sometimes causes stagnation or even retrogression in art creation. That was why vigorous Chinese painting almost became stereotyped for a long period in the 19th century.

At the beginning of the 20th century, some painters from Shanghai, Hangzhou, Nanjing, Guangzhou and Beijing started to challenge the old tradition of Chinese painting by introducing new art concepts from the West and establishing art school to train artists. The joint efforts were paid off. Most of these pioneer painters later became the backbone of New China's Art after 1949. And some are still active even today.

The ink painting has conducted certain reforms earlier this century, which may fall into two types. One reform was to get rid of the morbid psychology of self-admiration that some scholar painters in feudal China harbored, and establishes a healthy style. In this respect, Qi Baishi, whose name we mentioned previously, stood high above his contemporaries.

Qi's favorite subjects included flowers, insects, birds, landscapes and human figures. He not only studied the skills of these forerunners such as Xu Wei, Zhu Da, Yuan Ji and Wu Changshuo but also carefully observed the objects that he sketched. Outwardly he seemed to be very casual, but the flowers and birds that blossomed and flew from his brush all possessed the kind of characteristics they should have. With fluent lines and bright colors, he created a world full of life and rhythm.

The second type of reform was to accept Western art concepts and techniques and combine them with good tradition of Chinese painting. The pioneers tried to create a brand new national painting form on the basis of the existing form. One of the representatives in this bold experiment was Xu Beihong (1895-1953), who served in his lifetime as president of the Central Fine Arts Institute and chairman of the Chinese Artists Association.

Xu was most famous for his painting of horses. With a solid foundation in Chinese painting, he borrowed the best techniques from Western painting. In his paintings of human figures or animals, he was most accurate in the depiction of both spirit and form. Xu's works demonstrated not only his strong personality and creative spirit but also his patriotism, his sympathy with the working class, and his deep hatred for all evils.

Good paintings require good materials. The materials used in Chinese painting are writing brushes, ink sticks and slabs, and paper and silk, you can find all these materials in most of the souvenir shops.

Written by our column writer Hao Zhuo.

தாழி..!

 

தமிழன் தெரிந்துகொள்ளவேண்டிய தன் இனத்தின் பெருமை..!

அதை உலகிற்கே உரக்க சொல்லவேண்டியது ஒவ்வோர் தமிழனின் கடமை..!

உலகின் தொல் நாகரீகமே தமிழர்களுடையது அகழ்வாராய்ச்சி முடிவுகளை இந்திய மத்திய அரசு மூடிமறைப்பு.

தாமிரபரணி ஆற்றின் கரையில் ஆதிச்சநல்லூர் என்ற ஊர் உள்ளது. இது ஓர் இடுகாடு. இறந்தவர்களைப் புதைத்த இடம். இதன் பரப்பளவு 114 ஏக்கர். இங்கு 4 அடிக்கு ஒருவர் வீதம் தாழிகளில் இறந்தவர்களை வைத்துப் புதைத்துள்ளனர். தாழி என்றால் பானை என்பது பொருள். இவ்வாறு புதைக்கப்பட்ட பானைகளை முதுமக்கள் தாழி என்றும் ஈமத்தாழி என்றும் கூறுவர்.

தென்பாண்டி நாட்டில் இத்தாழிகள் ஏராளம் உண்டு. ஆதிச்ச நல்லூரில் ஆயிரக்கணக்கான தாழிகள் வரிசை வரிசையாகக் கிடைக்கின்றன. இதுதான் உலகிலேயே மிகப்பெரிய இடுகாடாகும். அது மட்டுமல்ல பத்தாயிரம் ஆண்டுகளுக்கு முன்னர் இவர்கள் புதைக்கப்பட்டுள்ளனர் என்பதும் இங்கே குறிப்பிடத்தக்கது.

இந்த ஆதிச்ச நல்லூர்… ஏறத்தாழ பத்தாயிரம் ஆண்டுகளுக்கு முன்பாக நமது மக்கள் நாகரீகத்தோடு வாழ்ந்த ஊர். ஆச்சரியமாக இருக்கிறதா?..ஆம் அதுதான் உண்மை. இந்த இடுகாடு[?]. கி.மு பத்தாம் நூற்ராண்டுக்கும் முந்தையது. இன்றைய ஆய்வுகள் மேலும் ஒரு ஆயிரம் வருடங்களை பின்னுக்குத் தள்ளலாம் என்று தெரிவிக்கின்றன. நாம் அறிந்த எந்த இந்திய சரித்திர காலகட்டத்துக்கும் முந்தைய காலகட்ட மக்களின் இடுகாடு இது.

தமிழ்க்குடியின் தொன்மைக்கான முதற்பெரும் தொல்பொருட் சான்றும் இதுவே. ஏறக்குறைய கிருஸ்து பிறப்பதற்கு எண்ணூறு வருடங்கள் முன்பே இங்கு நாகரீகம் மிகுந்த மக்கள் வாழ்ந்திருக்கிறார்கள். இதனை முதன் முதலில் கண்டுபிடித்தவர் ஜெர்மனி நாட்டைச் சேர்ந்த டாக்டர். ஜாகர் என்பவர்தான்.

1876 -ஆம் ஆண்டு இந்த பகுதியில் ஆராய்ச்சிக்காக வந்த அவர் கண்டுபிடித்ததுதான் இந்தத் தொல் தமிழர்களது நாகரீகம். அந்த ஜாகர் தான் கண்டுபிடித்தவற்றில் பலவற்றை ஆதாரத்துக்காக ஜெர்மனுக்கே எடுத்துச் சென்றுவிட்டார். அப்பொருட்கள் இன்னமும் ஜெர்மனியில் உள்ள பெர்லின் அருங்காட்சியகத்தில் இருக்கிறது.

பிரஞ்சு நாட்டைச் சார்ந்த லூயி வேப்பிக்கியூ என்ற அறிஞர் 1903 ஆம் ஆண்டு ஆதிச்ச நல்லூர் வந்து சில தாழிகளைத் தோண்டி எடுத்தார். அப்போது மண்வெட்டி, கொழு முதலியன கிடைத்தன. ஆதிச்ச நல்லூரில் அகழ்வாய்வில் கிடைத்த அந்தப் பொருள்களை அவர் பாரிசுக்கு எடுத்துப்போய்விட்டார்.

இவ்வாறு ஆதிச்ச நல்லூரில் கிடைத்த மிகத்தொன்மை வாய்ந்த பொருள்கள் மேல் நாட்டிற்கு எடுத்துச் செல்லப்பட்டன. அந்த புதைபொருள் சின்னங்கள் கிடைத்தால் ஆதிச்சநல்லூரின் தொன்மையான வரலாறு நமக்குத் மேலும் தெரியும்.

1905 ஆம் ஆண்டு சென்னை அருங்காட்சியக மதிப்புறு துணைக் கண்காணிப்பாளர் அலெக்சாந்தர் ரீயா அவர்கள் ஆதிச்சநல்லூர் வந்து மிகவும் நுணுக்கமாக அகழ்வாய்வு செய்து ஒரு பட்டியல் தயாரித்துக் கொடுத்ததோடு அகழ்ந்தெடுத்த பொருள்கள் அனைத்தையும் சென்னை அருங்காட்சியகத்தில் இடம்பெறச் செய்தார்.

இவரும் இங்குள்ள மக்கள் பயன்படுத்திய முதுமக்கள் தாழி, ஆபரணங்கள், எழுத்துக்கள் போன்றவற்றை அகழ்வாராய்ச்சி மூலம் ஆராய்ந்து பார்த்து விட்டு அதிர்ச்சியில் உறைந்து போனார்.

இதிலென்ன அதிர்ச்சி இருக்கிறது? என நினைக்கிறீர்களா? அந்த அதிர்ச்சிக்கு காரணம் அந்த அகழ்வாராய்ச்சியில் கண்டுபிடிக்கப்பட்ட அன்றைய மக்கள் பயன்படுத்திய இரும்பால் ஆன கருவிகள்தான். "மூவாயிரம் ஆண்டுகளுக்கு முன்பே இங்கு வாழ்ந்த தமிழர்கள் இரும்பைப் பயன்படுத்தி இருக்கிறார்கள் என்றால், அதை உருக்குவதற்கான உலைகளை எங்கு வைத்திருந்தார்கள், அதை செதுக்குவதற்கும் சீராக்குவதற்கும் எத்தகைய தொழில் நுட்பங்களைக் கையாண்டார்கள், அப்படியாயின் இவர்களது நாகரீகம்தான் மற்ற அனைத்து நாகரீகங்களுக்கும் முற்பட்ட நாகரீகமாக இருந்திருக்க வேண்டும் அல்லவா?.

பத்தாயிரம் ஆண்டுகளுக்கு முன்பே தமிழர்கள் இரும்பைக் கண்டுபிடித்து தேன் இரும்பு, வார்ப்பு இரும்பு, எஃகு இரும்பு ஆகியவற்றை உருவாக்கி இருக்கின்றனர் . பயிர்த்தொழில், சட்டிப்பானை வனையும் தொழில், நெசவுத் தொழில், கப்பல் கட்டும் தொழில் போன்றவற்றை இரும்புக் கருவிகள் மூலம் திறம்பட வளர்த்து கடல் வாணிபம் செய்து உலகப் புகழ்பெற்றவர்கள் தமிழர்கள் என ஆதிச்சநல்லூரில் கிடைத்த அகழ்வாய்வுச் சின்னங்கள் உறுதிப்படுத்துகின்றன. திராவிடர்கள் குறிப்பாக தமிழர்கள் வெளிநாட்டிலிருந்து இங்கு வந்தார்கள் என்ற கருத்துக்கு இந்த அகழ்வாய்வுச் சின்னங்கள் முடிவு கட்டியது குறிப்பிடத்தக்கதாகும்.

மிகத் தொன்மையான காலத்திலிருந்தே இரும்பைப் பிரித்தெடுத்து அதை பல பொருள்களாகச் செய்து பயன்படுத்துவதில் தமிழர்கள் கைதேர்ந்தவர்கள் என்று அறியமுடிகிறது. சங்க இலக்கியத்தில் இரும்பினால் செய்யப்பட்ட பொருள்கள் உவமையாகக் கூறப்பட்டுள்ளன.

மிகத் தொன்மையான காலத்திலேயே தமிழர்கள் எகிப்து, ஆப்பிரிக்கா, சுமேரியா, கிரீஸ், மெக்சிகோ முதலிய நாடுகளுக்கு இரும்புப் பொருள்கள் ஏற்றுமதி செய்து வந்தனர். எகிப்தியர்களும், கிரேக்கர்களும் இந்திய நாட்டில் இருந்துதான் இரும்பை உருக்கி பயன்படுத்தும் முறைகளை அறிந்தனர் என்று கூறப்படுகிறது.

1837ஆம் ஆண்டு இராயல் ஏஷியாட்டிக் சொசைட்டியில் சமர்ப்பித்த ஆய்வுக்கட்டுரை ஒன்றில் அறிஞர் ஹீத் என்பவர் தென் இந்தியாவில் செய்யப்பட்ட எஃகுப் பொருள்களே எகிப்துக்கும், ஐரோப்பா கண்டத்திற்கும் ஏற்றுமதி செய்யப்பட்டன என்று எடுத்துக்காட்டியுள்ளார்.

மெக்சிகோ நாட்டிலுள்ள பிரமிடுகளில் தமிழனின் கைவினைக் கலைகளைக் காணலாம். அண்மையில் எகிப்தில் கிடைத்த தமிழ் பிராமி கல்வெட்டிலிருந்து சாத்தன், கண்ணன் என்ற இரண்டு தமிழர்கள் கடல் பயணம் செய்து எகிப்து நாடு சென்று அங்கே கொல்லன் பட்டறை ஒன்று நிறுவி, பணி செய்ததாக கல்வெட்டு அறிஞர் ஐராவதம் மகாதேவன் குறிப்பிட்டுள்ளார். பிரமிடுகள் கட்டப் பயன்படுத்திய கற்களை செதுக்குவதற்குரிய உளிகள் இந்த கொல்லன் பட்டறையில் உருவாகி இருக்க வேண்டும். தமிழனின் இரும்பு நாகரிகத்தை வெளிப்படுத்தியது இந்த ஆதிச்ச நல்லூர்தான்.

அதனைத் தொடர்ந்து சகர்மேன் என்ற அறிஞர் ஆதிச்சநல்லூரில் கிடைத்த மண்டைஓடுகள் பற்றி ஒரு நூல் வெளியிட்டார். ஆதிச்ச நல்லூரில் அகழ்ந்து எடுக்கப்பட்ட மண்டை ஓடுகள் திராவிடர்களின் மண்டை ஓடுகள் என்றும், ஒன்று மட்டும் ஆஸ்திரேலிய பழங்குடி மக்களின் மண்டை ஓடு என்றும் அவர் கூறியுள்ளார்.

எனவே திராவிடர்களின் முன்னோர்கள் ஆஸ்திரேலிய நாட்டு பழங்குடி மக்களோடு தொடர்பு கொண்டிருந்தனர் என்று தெரியவருகிறது. அங்குள்ள பழங்குடி மக்கள் பேசும் மொழியில் தமிழ்ச் சொற்கள் இடம் பெற்றுள்ளமை இங்கே குறிப்பிடத்தக்கது. ஆஸ்திரேலியா தென் இந்தியாவோடு இணைந்திருந்தது என்ற கருத்தை மட்டுமல்ல குமரிக் கண்ட கோட்பாட்டையும் இது உறுதி செய்கிறது என்றும் கூறலாம். ஆஸ்திரேலிய பழங்குடி மக்கள் பயன்படுத்திய பூமராங் என்னும் ஒருவகை ஆயுதம் தமிழகத்தில் கிடைத்துள்ளதும் இங்கே குறிப்பிடத்தக்கது. பகைவர் மீது எறிந்தால் அவர்களைத் தாக்கிவிட்டு வீசியவர்கள் கைக்கு திரும்ப வரும் ஒருவகை ஆயுதம்தான் பூமராங்.

ஆதிச்சநல்லூரில் கிடைத்த தாழிகளில் மண்வெட்டி, கொழு, நெல், உமி, பழைய இற்றுப்போன பஞ்சாடை ஆகியவை கிடைத்துள்ளன என்பது குறிப்பிடத்தக்கது. ஆதிச்ச நல்லூரில் புதைக்கப்பட்டவர்கள் தாமிரபரணி கரையில் நெல், பருத்தி ஆகியவற்றை விவசாயம் செய்தது மட்டுமல்ல நெசவுத் தொழிலும் செய்து வந்தனர் என்று அறியமுடிகிறது.

ஆதிச்சநல்லூரில் அகழ்வாய்வு செய்ததில் டாக்டர் கால்டுவெல்லுக்கும் முக்கியமான பங்கு உண்டு. தாழியில் சில அரிய பொருட்களை அவரே கண்டெடுத்து அவற்றைப் பற்றிய செய்திகளை வெளியிட்டுள்ளார். ஆதிச்சநல்லூரில் வாழ்ந்த மக்கள் நாகரிகம் மிக்கவர்கள் என்ற கருத்தை டாக்டர் கால்டுவெல் வெளியிட்டார்.

ஆதிச்சநல்லூரின் மண்ணுக்குள் புதையுண்டு கிடக்கும் பூமியில் ஒரு பரபரப்பான நகரமே இயங்கிக் கொண்டிருந்திருக்கிறது. அங்கு வாழ்ந்த மனிதர்கள் வெள்ளி, செம்பு, தங்கத்தால் ஆன ஆபரணங்களைப் பயன்படுத்தி இருக்கிறார்கள். அழகிய மதிற்சுவர்கள் இருந்திருக்கின்றன. ஆனால் இன்றைக்கு அது யாரும் கேள்வி கேட்பாரற்ற பொட்டல்காடு.

ஏனிந்த நிலைமை என்று பார்த்தோமானால். "எல்லாம் அந்த பாழாய்ப்போன அரசியல்தான்" எல்லாம் இந்த வடக்கத்தியர்களுக்கு தமிழன் மேல் உள்ள காழ்ப்புணர்ச்சிதான். இதுதான் இன்றைய ராமேஸ்வரம் மீனவன் முதற்கொண்டு ஈழம் வரை நடந்து கொண்டிருக்கிறது.

இந்த ஆய்வுகளை ஒப்புக் கொண்டால் உலகின் தொல் நாகரீகமே தமிழர்களுடையது என்றாகிவிடுகிறது. அப்படியாயின் வெள்ளையர்களும் வடக்கத்தியர்களும் கண்டுபிடித்தவை எல்லாம் இதற்குப் பிந்தைய நாகரீகங்கள்தான் என்பதை ஒப்புக்கொண்டதாகி விடும். இதுதான் பிரச்னை.

இப்போது இங்குள்ள 150 ஏக்கர் நிலத்தை மத்திய அரசின் தொல்லியல் துறை சுற்றி வளைத்து கையகப்படுத்தி வைத்திருக்கிறது. 2005 ஆம் ஆண்டு அத்துறை செய்த ஆய்வுகளின் முடிவுகளைக் கூட இன்னமும் வெளிவிடாமல் வைத்திருக்கிறது. வேறு யாரும் இங்கு ஆய்வுகளை மேற்கொள்ளக் கூடாது என்று ஓர் உத்தரவையும் போட்டிருக்கிறது. இதுதான் இன்றைய சோகம்.
இதைச் உலகறியச் செய்யவேண்டியது மத்திய அரசு, செய்ய வலியுறுத்த வேண்டியது தமிழக அரசு.

நன்றி: தமிழ்ச்சாரல்

 

Shirdi vale sai baba

Left brain may also be emotional

NEUROSCIENCE RESEARCH AUSTRALIA

Share on print New Australian research is challenging the widely-held view that emotions and feelings are the domain of the right side of the brain only.  Image: chrysh/iStockphoto Ever been stuck in traffic when a feel-good song comes on the radio and suddenly your mood lightens? Our emotions and feelings are typically associated with the right side of the brain. For example, processing the emotion in human facial expressions is done in the right hemisphere. However, new Australian research is challenging the widely-held view that emotions and feelings are the domain of the right hemisphere only. Dr Sharpley Hsieh and colleagues from Neuroscience Research Australia (NeuRA) found that people with semantic dementia, a disease where parts of the left hemisphere are severely affected, have difficulty recognising emotion in music. These findings have exciting implications for our understanding of how music, language and emotions are handled by the brain. “It’s known that processing whether a face is happy or sad is impaired in people who lose key regions of the right hemisphere, as happens in people with Alzheimer’s and semantic dementia”, says Dr Hsieh. “What we have now learnt from looking at people with semantic dementia is that understanding emotions in music involves key parts of the other side of the brain as well”, she says. “Ours is the first study from patients with dementia to show that language-based areas of the brain, primarily on the left, are important for extracting emotional meaning from music. Our findings suggest that the brain considers melodies and speech to be similar and that overlapping parts of the brain are required for both”, says Hsieh. This paper is published in the journal Neuropsychologia. How was this study done? People with Alzheimer’s disease lose episodic memory (‘What did I do yesterday?’); people with semantic dementia lose semantic memory (‘What is a zebra?’). Dr Hsieh studied people with Alzheimer’s disease, semantic dementia and healthy people without either disease. Participants were played new pieces of music and had to indicate whether the song was happy, sad, peaceful or scary. Images were then taken of the patients’ brains using MRI so that diseased parts of the brain could be compared statistically to the answers provided in the musical test. Patients with Alzheimer’s and semantic dementia have problems deciding whether a human face looks happy or sad because the amygdala in the right hemisphere is diseased. Patients with semantic dementia have additional problems labelling whether a piece of music is happy or sad because the anterior temporal lobe in the left hemisphere is diseased. Editor's Note: Original news release can be found here.

New auto-immune treatment hope

THE UNIVERSITY OF NEW SOUTH WALES

Share on print Australian researchers have uncovered a potential new way to regulate the body’s natural immune response, offering hope of a simple and effective treatment for auto-immune diseases. Auto-immune diseases result from an overactive immune response that causes the body to attack itself. The new approach involves increasing good regulating cells in the body, unlike most current research focusing on stopping “bad” or “effector” cells, says lead researcher Dr Suzanne Hodgkinson from UNSW’s Faculty of Medicine and Liverpool Hospital. The researchers induced the body’s T-cell front-line defences by injecting cell-signalling proteins called cytokines, particularly Interleukin-5 (II-5 cytokine). When T-regulatory cells are grown in a way that makes them specific to a particular protein, they develop receptors for the Il-5 cytokine. The Il-5 cytokine boost allows the body’s immune system to better regulate its response to disease without going into overdrive. The team cloned II-5 cytokine and injected it into rats with the neurological condition Guillain–Barré syndrome. These rats recovered much quicker and did not fall ill if treated as a precaution. The method has also shown promise in animals with multiple sclerosis, kidney disease, nephritis and trying to overcome organ transplantation rejection. “One of the nice things about this discovery is that it is one of the few treatments in the auto-immune world and in the transplantation world that works not by attacking the effector cells but by increasing the good regulating cells. So it works very differently from almost every other treatment we’ve got available,” Dr Hodgkinson says. The researchers say that il-5 injections could be more palatable than inoculation by parasitic worms – another approach in regulating auto-immune conditions. International research shows swallowing helminth parasites can regulate the immune system and boost T-cell production to combat illnesses such as celiac disease and multiple sclerosis. The absence of worms in guts in the developed world has been cited as a possible cause for the sharp rise in auto-immune diseases in Western nations. “The process we’ve developed may be the same process that the helminths kick off. When you get a helminths infestation, one of the changes in your immune response is an increase in cells called eosinophils and these cells make the cytokine Interleukin-5,” Dr Hodgkinson says. “In this new treatment, it’s a matter of injecting the interleukin-5 and the body does the rest. It’s both safe and effective and we think inducing the immune response by injection may be more attractive to people than swallowing parasitic worms.” The next step is to take the treatment to human trials, which could be underway within two to five years, says Dr Hodgkinson, whose paper outlining the study has been published in the journalBlood. The research was supported by grants from Bob and Jack Ingham, Liverpool Australia; Multiple Sclerosis Research Australia; the Australian National Health and Medical Research Council; the Juvenile Diabetes Research Foundation; Novatis; and funds from UNSW. Lead researcher was UNSW research fellow Dr Giang Tran. Dr Hodgkinson and co-author Professor Bruce Hall hold US patents related to the treatment. Editor's Note: Original news release can be found here.

Magnets to direct cancer drugs

THE UNIVERSITY OF SYDNEY

Share on print For more than three decades scientists have been investigating magnetic nanoparticles as a method of drug delivery. Now by combining three metals - iron, gold and platinum - pharmacists at the University of Sydney believe they have discovered a method for magnetically directing drugs through the body. The discovery has been published online today in the international journal Inorganica Chimica Acta. Led by Dr Nial Wheate, a team of scientists from the Faculty of Pharmacy, along with collaborators in Scotland, have developed a new anticancer drug that has an iron oxide core as small as 5 nanometres in size (1/1000th the width of a human hair). "We coated this iron oxide core in a protective layer of gold before cisplatin, a platinum drug that revolutionised the treatment of testicular cancer, was attached to the gold coating using spaghetti-like strings of polymer." The important thing about this new drug, says Dr Wheate, is the ability of its iron core to move under the influence of a magnet; similar to the iron filing experiments many people have performed in science classes. "When we take regular medication it is difficult to manage where it goes. But this discovery means we can potentially direct exactly where in the human body a drug goes. We can move it to the desired cancer tumour site using powerful magnetic fields. Otherwise, a strong magnet could be implanted into a tumour, and draw the drug into the cancer cells that way." The technology was demonstrated when the team grew cancer cells in plates in the lab. When they placed a magnet under the plates, the drug affected and killed only those cells growing near the magnet, leaving the others unharmed, says Dr Wheate. "Many of the side-effects associated with chemotherapy occur because the drugs spread throughout the body, killing healthy organs as well as cancers. "Ultimately, this technology could greatly reduce or even eliminate the severe side-effects that people associate with chemotherapy such as hair loss, nausea, vomiting, low red blood cells and an increased risk of infection." This new drug technology could also be used to treat a range of cancers that have not been treatable with conventional platinum drugs, like prostate cancer. Platinum drugs are one of the most regularly used family of agents in chemotherapy and include cisplatin, carboplatin and oxaliplatin. Editor's Note: Original news release can be found here.

A different drummer: Neural rhythms drive physical movement

The 19th century mathematician Joseph Fourier showed that two rhythms could be summed to produce a third rhythm. Researchers at Stanford have shown that this principle is behind the brain activity that produces arm movements. Credit: Mark Churchland, Stanford School of Engineering

Unlike their visual cousins, the neurons that control movement are not a predictable bunch. Scientists working to decode how such neurons convey information to muscles have been stymied when trying to establish a one-to-one relationship between a neuron's behavior and external factors such as muscle activity or movement velocity.

In an article published online June 3rd by the journal Nature, a team of electrical engineers and neuroscientists working at Stanford University propose a new theory of the brain activity behind arm movements. Their theory is a significant departure from existing understanding and helps to explain, in relatively simple and elegant terms, some of the more perplexing aspects of the activity of neurons in motor cortex.

In their paper, electrical engineering Associate Professor Krishna Shenoy and post-doctoral researchers Mark Churchland, now a professor at Columbia, and John Cunningham of Cambridge University, now a professor at Washington University in Saint Louis, have shown that the brain activity controlling arm movement does not encode external spatial information—such as direction, distance and speed—but is instead rhythmic in nature.

Understanding the brain

Neuroscientists have long known that the neurons responsible for vision encode specific, external-world information—the parameters of sight. It had been theorized and widely suggested that motor cortex neurons function similarly, conveying specifics of movement such as direction, distance and speed, in the same way the visual cortex records color, intensity and form.

"Visual neurons encode things in the world. They are a map, a representation," said Churchland, who is first author of the paper. "It's not a leap to imagine that neurons in the motor cortex should behave like neurons in the visual cortex, relating in a faithful way to external parameters, but things aren't so concrete for movement."

Scientists have disagreed about which movement parameters are being represented by individual neurons. They could not look at a particular neuron firing in the motor cortex and determine with confidence what information it was encoding.

"Many experiments have sought such lawfulness and yet none have found it. Our findings indicate an alternative principle is at play," said co-first author Cunningham.

"Our main finding is that the motor cortex is a flexible pattern generator, and sends rhythmic signals down the spinal cord," said Churchland.

Engine of movement

To employ an automotive analogy, the motor cortex is not the steering wheel, odometer or speedometer representing real-world information. It is more like an engine, comprised of parts whose activities appear complicated in isolation, but which cooperate in a lawful way as a whole to generate motion.

"If you saw a piston or a spark plug by itself, would you be able to explain how it makes a car move?" asked Cunningham rhetorically. "Motor-cortex neurons are like that, too, understandable only in the context of the whole."

In a series of striking graphs, the Stanford team plotted the signals from individual neurons in the motor-cortex as monkeys completed a series of reaches. The reaching motions are shown by the starburst patterns at the top left of each graph. The neuronal patterns are then plotted atop one another for the entire series of reaches, clearly establishing the rhythmic nature of the brain activity. Credit: Mark Churchland, Stanford School of Engineering

In monitoring electrical brain activity of motor-cortex neurons, researchers found that they typically exhibit a brief oscillatory response. These responses are not independent from neuron to neuron. Instead, the entire neural population oscillates as one in a beautiful and lawfully coordinated way.

The electrical signal that drives a given movement is therefore an amalgam – a summation – of the rhythms of all the motor neurons firing at a given moment.

"Under this new way of looking at things, the inscrutable becomes predictable," said Churchland. "Each neuron behaves like a player in a band. When the rhythms of all the players are summed over the whole band, a cascade of fluid and accurate motion results."

Dr. Daofen Chen, Program Director, Systems and Cognitive Neuroscience at the National Institute of Neurological Disorders and Stroke at the National Institutes of Health, said Shenoy and team are working at the cutting edge of the field. "In trying to find the basic response properties of the motor cortex, Dr. Shenoy and his colleagues are searching for the holy grail of neuroscience," said Dr. Chen. "His team has been consistent in tackling important but tough questions, often in thought-provoking ways and in ambitious proposals. NIH is proud to support this kind of pioneering and transformative research."

Precedents in nature

In the new model, a few relatively simple rhythms explain neural features that had confounded science earlier.

"Many of the most-baffling aspects of motor-cortex neurons seem natural and straightforward in light of this model," said Cunnigham.

The team studied non-rhythmic reaching movements, which made the presence of rhythmic neural activity a surprise even though, the team notes, rhythmic neural activity has a long precedence in nature. Such rhythms are present in the swimming motion of leeches and the gait of a walking monkey, for instance.

"The brain has had an evolutionary goal to drive movements that help us survive. The primary motor cortex is key to these functions. The patterns of activity it displays presumably derive from evolutionarily older rhythmic motions such as swimming and walking. Rhythm is a basic building block of movement," explained Churchland.

Reaching for the grail

To test their hypothesis, the engineers studied the brain activity of monkeys reaching to touch a target. According to the researchers, experiments show this 'underlying rhythm' strategy works very well to explain both brain and muscle activity. In their reaching studies, the pattern of shoulder-muscle behavior could always be described by the sum of two underlying rhythms.

"Say you're throwing a ball. Beneath it all is a pattern. Maybe your shoulder muscle contracts, relaxes slightly, contracts again, and then relaxes completely, all in short order," explained Churchland. "That activity may not be exactly rhythmic, but it can be created by adding together two or three other rhythms. Our data argue that this may be how the brain solves the problem of creating the pattern of movement."

"Finding these brain rhythms surprised us a bit, as the reaches themselves were not rhythmic. In fact, they were decidedly arrhythmic, and yet underlying it all were these unmistakable patterns," said Churchland.

"This research builds on a strong theoretical framework and adds to growing evidence that rhythmic activity is important for many fundamental brain functions," said Yuan Liu of the National Institute of Neurological Disorders and Stroke, NIH. "Further research in this area may help us devise more effective technology for controlling prosthetic limbs." Liu is the co-lead of the NIH-NSF Collaborative Research in Computational Neuroscience program.

"In this model, the seemingly complex system that is the motor cortex can now be at least partially understood in more straightforward terms. The motor cortex is an engine of movement that obeys lawful dynamics," said Shenoy.

Stanford post-doctoral fellow Matthew Kaufman, bioengineering PhD student and medical science training program student Paul Nuyujukian, electrical engineering graduate student Justin Foster, and electrical engineering consulting assistant professor and Palo Alto Medical Foundation neurosurgeon Stephen Ryu were also authors on this paper.

Provided by Stanford University

"A different drummer: Neural rhythms drive physical movement." June 3rd, 2012.http://medicalxpress.com/news/2012-06-drummer-neural-rhythms-physical-movement.html

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Robert Karl Stonjek

Brain scans prove Freud right: Guilt plays key role in depression

Scientists have shown that the brains of people with depression respond differently to feelings of guilt – even after their symptoms have subsided.

University of Manchester researchers found that the brain scans of people with a history of depression differed in the regions associated with guilt and knowledge of socially acceptable behaviour from individuals who never get depressed.

The study – published in the journal Archives of General Psychiatry – provides the first evidence of brain mechanisms to explain Freud's classical observation that exaggerated guilt and self-blame are key to understanding depression.

Lead researcher Dr Roland Zahn, from the University's School of Psychological Sciences, said: "Our research provides the first brain mechanism that could explain the classical observation by Freud that depression is distinguished from normal sadness by proneness to exaggerated feelings of guilt or self-blame.

"For the first time, we chart the regions of the brain that interact to link detailed knowledge about socially appropriate behaviour – the anterior temporal lobe – with feelings of guilt – the subgenual region of the brain – in people who are prone to depression."

The study used functional magnetic resonance imaging (fMRI) to scan the brains of a group of people after remission from major depression for more than a year, and a control group who have never had depression. Both groups were asked to imagine acting badly, for example being 'stingy' or 'bossy' towards their best friends. They then reported their feelings to the research team.

"The scans revealed that the people with a history of depression did not 'couple' the brain regions associated with guilt and knowledge of appropriate behaviour together as strongly as the never depressed control group do," said Dr Zahn, a MRC Clinician Scientist Fellow.

"Interestingly, this 'decoupling' only occurs when people prone to depression feel guilty or blame themselves, but not when they feel angry or blame others. This could reflect a lack of access to details about what exactly was inappropriate about their behaviour when feeling guilty, thereby extending guilt to things they are not responsible for and feeling guilty for everything."

The research, part-funded by the Medical Research Council (MRC), is important because it reveals brain mechanisms underlying specific symptoms of depression that may explain why some people react to stress with depression rather than aggression.

The team is now investigating whether the results from the study can be used to predict depression risk after remission of a previous episode. If successful, this could provide the first fMRI marker of risk of future depression.

More information: 'Guilt-Selective Functional Disconnection of Anterior Temporal and Subgenual Cortices in Major Depressive Disorder,' by Sophie Green et al., Archives of General Psychiatry, 2012.

Provided by University of Manchester

"Brain scans prove Freud right: Guilt plays key role in depression." June 4th, 2012.http://medicalxpress.com/news/2012-06-brain-scans-freud-guilt-key.html

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Robert Karl Stonjek