Saturday, June 23, 2012
மரக்கரியில் இயங்கிய பஸ்
கோவை: தமிழகத்தில் பஸ் பயணம் அவ்வளவு அறிமுகமில்லாத காலத்தில் கோவையிலிருந்து உடுமலை வழியாக பழனிக்கு மரக்கரியை பயன்படுத்தி இயக்கப்படும் பஸ் ஒன்றை கோவையைச் சேர்ந்த பிரபல விஞ்ஞானி ஜி.டி.நாயுடு இயக்கியுள்ளார். ஒருவர் வண்டியை ஓட்ட மற்றொருவர் பின்புறம் அமைந்துள்ள பாய்லரில் மரக்கரியை போட்டு எரித்துக் கொண்டே செல்ல வேண்டும். அந்த காலத்தில் இந்த பஸ்சில் பயணம் செய்ய வேண்டும் என்ற ஆவலில் பலர் மாட்டு வண்டி பூட்டி கோவை வந்து பயணிப்பார்களாம். கோவை அவினாசி ரோட்டில் உள்ள ஜிடி நாயுடு நினைவு இல்லத்தில் இந்த பஸ் இன்றும் கூட இயங்கும் நிலையில் பராமரிக்கப்பட்டு வருகிறது.
first bus
அதுபோக நாடு சுதந்திரம் அடைவதற்கு முன்னதாகவே தானியங்கி டிக்கெட், ரேடியேட்டர் அதிர்வு கருவி, பேருந்து வழித்தட கருவி என அதிசய இயந்திரங்களை கண்டறிந்து மாடர்னாக பஸ்ஸை அறிமுகப்படுத்தி பெருமை சேர்த்தவர் கோவையை சேர்ந்த அறிவியல் மாமேதை ஜி.டி. நாயுடு.
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ஆனால் இனியாவது ஒரு தமிழ் விஞ்ஞானியை மக்களுக்கு காட்டுவோம்...மறக்காமல் SHARE செய்யவும்
Friday, June 22, 2012
Highways of the brain: High-cost and high-capacity
A new study proposes a communication routing strategy for the brain that mimics the American highway system, with the bulk of the traffic leaving the local and feeder neural pathways to spend as much time as possible on the longer, higher-capacity passages through an influential network of hubs, the so-called rich club.
The study, published this week online in the Early Edition of the Proceedings of the National Academy of Sciences, involves researchers from Indiana University and the University Medical Center Utrecht in the Netherlands and advances their earlier findings that showed how select hubs in the brain not only are powerful in their own right but have numerous and strong connections between each other.
The current study characterizes the influential network within the rich club as the "backbone" for global brain communication. A costly network in terms of the energy and space consumed, said Olaf Sporns, professor in the Department of Psychological and Brain Sciences at IU Bloomington, but one with a big pay-off: providing quick and effective communication between billions and billions of brain cells.
"Until now, no one knew how central the brain's rich club really was," Sporns said. "It turns out the rich club is always right in the middle when it comes to how brain regions talk to each other. It absorbs, transforms and disseminates information. This underscores its importance for brain communication."
In earlier work, using diffusion imaging, the researchers found a group of 12 strongly interconnected bihemispheric hub regions, comprising the precuneus, superior frontal and superior parietal cortex, as well as the subcortical hippocampus, putamen and thalamus. Together, these regions form the brain's "rich club." Most of these areas are engaged in a wide range of complex behavioral and cognitive tasks, rather than more specialized processing such as vision and motor control.
For the current study, Martijn van den Heuvel, a professor at the Rudolf Magnus Institute of Neuroscience at University Medical Center Utrecht, used diffusion tensor imaging data for two sets of 40 healthy subjects to map the large-scale connectivity structure of the brain. The cortical sheet was divided into 1,170 regions, and then pathways between the regions were reconstructed and measured. As in the previous study, the rich club nodes were widely distributed and had up to 40 percent more connectivity compared to other areas.
The connections measured -- almost 700,000 in total -- were classified in one of three ways: as rich club connections if they connected nodes within the rich club; as feeder connections if they connected a non-rich club node to a rich club node; and as local connections if they connected non-rich club nodes. Rich club connections made up the majority of all long-distance neural pathways. The study also found that connections classified as rich club connections were used more heavily for communication than other feeder and local connections. A path analysis showed that when a minimally short path is traced from one area of the brain to another, it travels through the rich club network 69 percent of the time, even though the network accounts for only 10 percent of the brain.
A common pattern in communication paths spanning long distances, Sporns said, was that such paths involved sequences of steps leading across local, feeder, rich club, feeder and back to local connections. In other words, he said, many communication paths first traveled toward the rich club before reaching their destinations.
"It is as if the rich club acts as an attractor for signal traffic in the brain," Sporns said. "It soaks up information which is then integrated and sent back out to the rest of the brain."
Van den Heuvel agreed.
"It's like a big 'neuronal magnet' for communication and information integration in our brains," he said. "Seeking out the rich club may offer a strategy for neurons and brain regions to find short communication paths across the brain, and might provide insight into how our brain manages to be so highly efficient."
From an evolutionary standpoint, it was important for the brain to minimise energy consumption and wiring volume. Still, if these were the only factors, there would be no rich club because of the extra resources it requires, Sporns said. The rich club is expensive, at least in terms of wiring volume, and perhaps also in terms of metabolic cost. The trade-off for higher cost, Sporns said, is higher performance -- the integration of diverse signals and the ability to select short paths across the network.
"Brain neurons don't have maps; how do they find paths to get in touch? The rich club may help with this, offering the brain's neurons and regions a way to communicate efficiently based on a routing strategy that involves the rich club.
People use related strategies to navigate social networks.
"Strangely, neurons may solve their communication problems just like the people they belong to," Sporns said.
More information: "High-cost, high-capacity backbone for global brain communication" PNAS, 2012.
Provided by Indiana University
"Highways of the brain: High-cost and high-capacity." June 18th, 2012. http://medicalxpress.com/news/2012-06-highways-brain-high-cost-high-capacity.html
Posted by
Robert Karl Stonjek
Children, brain development and the criminal law
The legal system needs to take greater account of new discoveries in neuroscience that show how a difficult childhood can affect the development of a young person's brain which can increase the risk adolescent crimes, according to researchers. The research will be presented as part of an Economic and Social Research Council seminar series in conjunction with the Parliamentary Office of Science and Technology.
Neuroscientists have recently shown that early adversity – such as a very chaotic and frightening home life – can result in a young child becoming hyper vigilant to potential threats in their environment. This appears to influence the development of brain connectivity and functions.
Such children may come to adolescence with brain systems that are set differently, and this may increase their likelihood of taking impulsive risks. For many young offenders such early adversity is a common experience, and it may increase both their vulnerability to mental health problems and also their risk of problem behaviours.
These insights, from a team led by Dr Eamon McCrory, University College London, are part of a wave of neuroscientific research questions that have potential implications for the legal system.
Other research by Dr Seena Fazel of Oxford University has shown that while social disadvantage is a major risk factor for offending, a Traumatic Brain Injury (TBI) - from an accident or assault – significantly increases the risk of involvement in violent crime. Professor Huw Williams, at University of Exeter, has similarly shown that around 45 per cent of young offenders have TBI histories, and more injuries are associated with greater violence.
Professor Williams said: "The latest message from neuroscience is that young people who suffer troubled childhoods may experience a kind of 'triple whammy'. A difficult social background may put them at greater risk of offending and influence their brain development early on in childhood in a way that increases risky behaviour. This can then increase their chances of experiencing an injury to their brains that would compromise their ability to stay in school or contribute to society still further."
Professor Williams wants to see better communication between neuroscientists, clinicians and lawyers so that research findings like these lead to changes in the legal system. "There is a big gap between research conducted by neuroscientists and the realities of the day to day work of the justice system," he said. "Although criminal behaviour results from a complex interplay of a host of factors, neuroscientists and clinicians are identifying key risk factors that – if addressed – could reduce crime. Investment in earlier, focussed interventions may offset the costs of years of custody and social violence".
Dr Eileen Vizard, a prominent adolescent forensic psychiatrist, will talk at the event Neuroscience, Children and the Law, about how the criminal justice system needs to be changed to age appropriate sentencing for children as young as ten years old, whilst also providing for the welfare needs of these deprived children. Laura Hoyano – a leading expert on vulnerable people in criminal courts – will discuss the problems children face when testifying in criminal courts.
Provided by Economic & Social Research Council
"Children, brain development and the criminal law." June 18th, 2012. http://medicalxpress.com/news/2012-06-children-brain-criminal-law.html
Posted by
Robert Karl Stonjek
Robert Karl Stonjek
Don’t Break The Oath
 “Understanding that Rama’s beauty, patience, age and ancestry were completely perfect, the king remembered his own oath and thus started to lament.” (Janaki Mangala, 48)
rūpa sīla baya baṃsa rāma parisurana |
samujhi kaṭhina pana āpana lāga bisūrana ||
You think long and hard about a difficult decision. You don’t want to mess up because the stakes are high. Rather than make an impulse move, you get advice from the people you trust. This way you gather all sorts of opinions and viewpoints that you may not have considered yourself due to the attachment you have to the particular situation. Finally, you settle upon something, a move that will hopefully satisfy your wishes and alleviate your concerns. If you are a man of honor, this decision represents your vow, something you can’t break. But then later on, after the decision is made, a wildcard enters the equation. If you knew about this beforehand, you never would have made your vow. So now you are in trouble. What to do?
This was the situation faced by a famous king many thousands of years ago. He was childless when he found a beautiful baby girl in the ground one day while ploughing a field for a sacrifice. What an odd place to find a young child? How was she still alive? Who had placed her there? These things didn’t matter to King Janaka once he picked her up. Though he was above the influence of the senses, he couldn’t help but harbor affection for this innocent girl, wiping the dust off her face. He wanted to bring her home immediately, but he knew that he shouldn’t take someone else’s property. Then a voice from the sky told the king that the girl was his daughter in all righteousness, or dharma.
 Dharma was important to Janaka. A king who doesn’t follow dharma isn’t much of a king. To be a good protector, one must be able to govern the citizens in such a way that they all stay happy, regardless of their situation. The only way to make this a reality is to follow the established law codes of scripture, which are presented nicely in the Vedas. If you go on your own whim, others will then have license to do so as well. As desires for personal satisfaction are sure to clash, the result is stiff competition. Man’s actions are then guided by the motto of “win at all costs”. In fact, this is the situation at present, where government leaders operate on the mentality that whoever will provide them the most votes should gain the most favor from government. Never mind that every person is equally a citizen and that the leader should be impartial. Send money to a candidate and you will get a seat at the table of power should they get elected.
Janaka’s guiding principle was to defer to dharma, so he was thrilled to hear that this girl was actually his daughter. The higher powers decided he should raise her as his own daughter, that he was worthy of having her and that she would bestow good fortune upon him. The baby girl was Lakshmi Devi appearing on earth to grace the line of Videha kings with the greatest fortune of all, the appearance of the Supreme Lord in their kingdom. Janaka, of course, did not know these things. He had a spontaneous and loving attachment to his daughter.
This attachment made arranging for her marriage quite difficult. As Janaka belonged to the royal order, he typically would find a suitable match based on strength. The ability of the prince to protect his daughter would be the overriding factor in determining his eligibility for marriage. The suitable match would also be determined off personal characteristics calculated from the alignment of stars at the time of birth. The problem was that Janaka didn’t know his daughter Sita’s exact date of birth or who her parents were. How then was he going to find a suitable match? Comparing horoscopes using Vedic science takes the guesswork out of these arrangements.
Janaka met with his counselors, and they settled upon a compromise. The king would hold a contest. Whoever could lift Lord Shiva’s bow would win Sita’s hand in marriage. First come, first serve. No round robins or heats. Whoever could lift it first would win the contest. The idea was that the bow was too heavy for anyone to lift. Just as Sita had amazingly appeared from the ground, her future husband would have to appear on the scene and miraculously lift the bow.
 There was another side to this contest that Janaka didn’t immediately realize. If someone should attempt to lift the bow and fail, they would be automatically disqualified from marrying Sita. The focus was on finding someone who could lift the bow, which meant the elimination factor was ignored. But what if someone showed up to Janaka’s city who was perfect in every way? What if their beauty was unmatched and their ancestry sparkling? What if they had tremendous patience and dedication to chivalry? What if they were quite strong and had a charming visage? Then what could the king do?
Wouldn’t you know it, this is precisely the predicament that arose. Though princes from around the world came to participate in the contest, two notable warriors didn’t get the invitation. They were away from home at the time, protecting the sadhus from the enemies of the demigods. A sura is known as a demigod or devotee in Sanskrit. Their enemies are the asuras, the negation of the word “sura”. “How can someone be an enemy of a sadhu, a person who has no possessions and who hardly bothers anyone? A demigod is adeity in charge of a particular aspect of creation. Why should they have enemies?”
As we know, sometimes the workings of the criminal mind are impossible to figure out. There are bad guys out there, whether we like it or not. Since they do horrible things, someone needs to be there to punish them, to protect the innocent from their influence. Rama and Lakshmana, though very young, were quite able to protect a notable sadhu named Vishvamitra. He was being harassed by night-rangers who fought dirty. In conventional warfare, the participants wear identifiable uniforms and engage in conflict once the other party is ready. It seems strange, but warriors usually follow some sort of standard procedure when engaging in armed conflict.
Oh, but not these night-rangers. They would not announce their presence until the moment of attack. Should they be spotted, they could use illusion to disappear from the vision. They would take on another shape to mask their appearance as well. Rama’s first test was to fight against and kill a very wicked female night-ranger named Tataka. Rama was very hesitant to kill her since she was a female. Vishvamitra had to insist a few times to Rama to fight with as much force as possible. The night-ranger would use illusion quite often to try to escape, but no one can live when the Supreme Lord decides that they shouldn’t.
 Rama was the Supreme Lord appearing on earth in the guise of a human being. The purpose given for His descents is to annihilate the miscreants and defend the pious, but in reality there needn’t be a specific purpose. Whatever makes the Supreme Lord happy, He does. He finally killed Tataka, and Vishvamitra was pleased with Him. He then gave both Rama and Lakshmana secret mantras to be used in fighting.
The group subsequently went to Janaka’s kingdom while the contest was going on. The king welcomed them hospitably, and was enamored by the vision of Rama and Lakshmana. As Rama was the elder brother, Janaka wondered if He should maybe participate in the contest. Seeing that Rama was perfect in every way, Janaka became lost in transcendental bliss. He had previously felt brahmasukha, or the pleasure of merging into the impersonal effulgence of the Lord, but this new happiness defeated that many times over.
After that initial happiness, Janaka remembered his vow. “Oh no! What if Rama tries to lift the bow and fails? Then He can’t marry Sita, though He is perfect for her.” In this way Janaka felt a kind of fear in devotional ecstasy. This emotion is described in more detail in Shrila Rupa Gosvami’s Bhakti-rasamrita-sindhu, which is nicely translated and commented on in the book known as The Nectar of Devotion, authored by His Divine Grace A.C. Bhaktivedanta Swami Prabhupada.
In devotional service, or bhakti-yoga, there are different tastes that are available to the devotee. Sometimes fear is an enhancer of delight, as through that trepidation one thinks even more about God. Thus Janaka’s worrying over the contest was on par with his happiness over first seeing Rama. There needn’t be any worry, though. Lord Rama was meant to arrive in Janaka’s kingdom and marry Sita. Only He would be able to lift Mahadeva’s bow and thus prove to the world that Sita could only be His wife. Janaka’s regret would soon disappear, as his vow would further glorify both Sita and Rama, the divine couple who bestow good fortune upon the surrendered souls.
In Closing:
Daughter Sita to Janaka is very dear,
That wrong husband chosen is underlying fear.
With announced contest of bow matter considered rectified,
Priests, counselors, friends and even king now satisfied.
Contest rules simple, first come first serve,
Lifting Shiva’s bow meant Sita they did deserve.
But if perfect match arrived Janaka did not consider,
The case with Rama, but on vow the king must deliver.
Thus there was worry that with vow he made a grave mistake,
But king relieved when Shiva’s bow in His hand Rama did take.
|
'Hallucinating' robots arrange objects for human use
A robot populates a room with imaginary human stick figures in order to decide where objects should go to suit the needs of humans.
(Phys.org) -- If you hire a robot to help you move into your new apartment, you won't have to send out for pizza. But you will have to give the robot a system for figuring out where things go. The best approach, according to Cornell researchers, is to ask "How will humans use this?"
Researchers in the Personal Robotics Lab of Ashutosh Saxena, assistant professor of computer science, have already taught robots to identify common objects, pick them up and place them stably in appropriate locations. Now they've added the human element by teaching robots to "hallucinate" where and how humans might stand, sit or work in a room, and place objects in their usual relationship to those imaginary people.
Their work will be reported at the International Symposium on Experimental Robotics, June 21 in Quebec, and the International Conference of Machine Learning, June 29 in Edinburgh, Scotland.
Previous work on robotic placement, the researchers note, has relied on modeling relationships between objects. A keyboard goes in front of a monitor, and a mouse goes next to the keyboard. But that doesn't help if the robot puts the monitor, keyboard and mouse at the back of the desk, facing the wall.
Above left, random placing of objects in a scene puts food on the floor, shoes on the desk and a laptop teetering on the top of the fridge. Considering the relationships between objects (upper right) is better, but he laptop is facing away from a potential user and the food higher than most humans would like. Adding human context (lower left) makes things more accessible. Lower right: how an actual robot carried it out. (Personal Robotics Lab)
Eventually it learns commonalities: There are lots of imaginary people sitting on the sofa facing the TV, and the TV is always facing them. The remote is usually near a human's reaching arm, seldom near a standing person's feet. "It is more important for a robot to figure out how an object is to be used by humans, rather than what the object is. One key achievement in this work is using unlabeled data to figure out how humans use a space," Saxena said.
In a new situation the a robot places human figures in a 3-D image of a room, locating them in relation to objects and furniture already there. "It puts a sample of human poses in the environment, then figures out which ones are relevant and ignores the others," Saxena explained. It decides where new objects should be placed in relation to the human figures, and carries out the action.
The researchers tested their method using images of living rooms, kitchens and offices from the Google 3-D Warehouse, and later, images of local offices and apartments. Finally, they programmed a robot to carry out the predicted placements in local settings. Volunteers who were not associated with the project rated the placement of each object for correctness on a scale of 1 to 5.
Comparing various algorithms, the researchers found that placements based on human context were more accurate than those based solely in relationships between objects, but the best results of all came from combining human context with object-to-object relationships, with an average score of 4.3. Some tests were done in rooms with furniture and some objects, others in rooms where only a major piece of furniture was present. The object-only method performed significantly worse in the latter case because there was no context to use. "The difference between previous works and our [human to object] method was significantly higher in the case of empty rooms," Saxena reported.
The research was supported by a Microsoft Faculty Fellowship and a gift from Google. Marcus Lin, M.Eng. '12, received an Academic Excellence Award from the Department of Computer Science in part for his work on this project.
Provided by Cornell University
"'Hallucinating' robots arrange objects for human use." June 18th, 2012. http://phys.org/news/2012-06-hallucinating-robots-human.html
Posted by
Robert Karl Stonjek
Robert Karl Stonjek
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