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Thursday, July 28, 2011

Older people find it harder to see the wood for the trees


 Psychology & Psychiatry 
When looking at a picture of many trees, young people will tend to say: "This is a forest". However, the older we get, the more likely we are to notice a single tree before seeing the forest. This suggests that the speed at which the brain processes the bigger picture is slower in older people. In a new study published in the July-August issue of Elsevier´s Cortex, researchers have found that these age-related changes are correlated with a specific aspect of visual perception, known as Gestalt perception.
Markus Staudinger, together with Gereon R. Fink, Clare E. Mackey, and Silke Lux, investigated the brain's ability to focus on the local and global aspects of visual stimuli, in a group of young and elderly healthy subjects. They also studied how this ability is related to Gestalt perception, which is the mind's tendency to perceive many similar smaller objects as being part of a bigger entity. As expected, older people found it more difficult to concentrate on the global picture, but they also had trouble with the Gestalt principle of Good Continuation – the mind's preference for continuous shapes.
Participants in the study were shown groups of letters which were arranged in a pattern so that they formed a larger letter (see below), and asked whether a letter appeared on the local or global level. Importantly, the number of small letters forming the pattern was then varied. Usually, the smaller the letters are in the pattern, the easier it is to perceive the larger letter, and this was indeed true for the younger participants in the study. However, varying the number of letters did not help the older people, who remained slower to notice the global figure.
These findings provide the first evidence that changes in attention - meaning, the ability to concentrate on one thing, while ignoring others - and in Gestalt perception are correlated to healthy aging. More generally, they show that there may be age-related changes in different cognitive domains which interact. Furthermore, the results help us understand which specific aspects of visual perception become impaired in healthy aging.
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More information: The article is "Gestalt perception and the decline of global precedence in older subjects" by Markus R. Staudinger, Gereon R. Fink, Clare E. Mackay, and Silke Lux, and appears in Cortex, Volume 47, Issue 7 (July 2010)
Provided by Elsevier
"Older people find it harder to see the wood for the trees." July 25th, 2011. http://medicalxpress.com/news/2011-07-older-people-harder-wood-trees.html
Posted by
Robert Karl Stonjek

எங்கே போகிறது மனிதம்?


 
images2.jpg
கண்முன்னே கொலை நடந்தாலும்
தட்டிக் கேட்க முடியாத அல்லது
மனமில்லாத மனிதம்

நமக்கென்ன ஆனது என்ற எண்ணமோ
தலையிட்டால் தனக்கும் கொலைதான்  
என்ற அச்சமோ தடுக்க வாய் மூடி 
அநியாயத்தை கடந்து செல்லும் மனிதம்

அண்டை வீட்டிலே இடி  விழுந்தாலும்
நம் வீட்டுக்கு வராதவரை நன்மை 
என்றே நினைக்கும்  மனிதம்

பெண் என்றால் போதும் என
பச்சிளம் குழந்தையை கூட பலியாக்கும் 
காம வெறி கொண்ட மனிதம் 

உயிரற்ற பொருட்களை கொள்ளை அடிக்க
உயிரை விலையாய் பிடுங்கும் மனிதம்.

வறியவனை ஏய்த்து பிடுங்கும்
வலியவனின் மனிதம்

எங்கே போகிறது மனிதம்?
ஒருவரை ஒருவர் கொன்று தின்னும் 
காலமும் வந்து விடுமோ?

என்றும் அன்புடன் 
ஸ்ரீ
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Fields of Gold



Lord Rama“Devotion to Shri Rama is like the rainy season, the wonderful devotees the paddy fields, and the two syllables in Rama’s name the months of Sawan and Bhadon [rainy season], says Tulsi.” (Dohavali, 25)
baraṣā ritu raghupati bhagati tulasī sāli sudāsa | 
rāmanāma bara barana juga sāvana bhādava māsa ||
The name of Lord – who is the jewel of the Raghu dynasty, the husband of Sita, the elder brother of Lakshmana, and the object of worship for Hanuman – completes the devotee; it defines their very existence. Without this sacred sound vibration they would be left to die with no savior, for without remembrance of the Supreme Personality of Godhead, of what use is there to advanced intelligence, the ability to speak, and the ability to ponder over the difficult questions in life? The devotees adore their beloved Lord so much that they will never run out of ways to glorify Him and make comparisons using their surroundings to accurately convey the beauty and wonder of devotion to Him. In this way the neti neti statements of the Vedas serve as the most wonderful boon for the poet-like bhakta, as the Supreme Absolute Truth’s indescribability allows for an eternal engagement aimed at glorifying Him in an infinite number of ways, each of which is guaranteed to fall short of perfection but still keeps the mind ever engaged.
Rama DarbarWhat does neti neti mean exactly? The Supreme Absolute Truth, that one entity who is beyond the dualities of heat and cold, gain and loss, and birth and death, remains impossible for the mind to fathom properly. Without expert guidance from one who is intimately acquainted with the true nature of the Truth, the best the mind can reach is a fuzzy conception of a beam of light or a void. Since everything around them is visibly manifest, the inquisitive transcendentalist may conjure up the image of the Lord as invisible, or alakshyam. But without the vision provided by Vedic wisdom heard from an authorized source, the true nature of this “invisible man” will remain unknown. The Vedas therefore describe the Absolute Truth as being neti neti, or “not this, not that”. We can look all around us, leave no stone unturned, but we’ll still never find the Absolute Truth. After studying every aspect of the creation, we can accurately conclude that the Supreme Truth must not be of this world.
According to the Vedas, the system of spirituality so ancient that no one can accurately date its inception, the person we refer to as God is indeed a person, but His potencies and attributes are inconceivable to the mind. The devotees, those who understand that God has a form and a personality, consider this limitation a blessing. Their mindset follows something like this: “Oh, so I can never fully describe the beauty and wonder of my beloved Lord, the owner of my life breath, the reason for my very existence? Wonderful. This means that I can spend the rest of this and many other lifetimes engaged in describing His glories and never reach the end. As such, I can always remain in the devotional mindset and never have to worry about exhausting my efforts.”
Hanuman chantingThe devotional attitude is one where the original Personality is acknowledged and worshiped on a daily basis. Inward worship can at best lead to the understanding of the Supreme Lord as an invisible force, and outward worship can at best bring one to worship within a temple or in the direct audience of the Supreme Person. But in both instances the outpouring of emotion is limited, because the Supreme Lord is actually both within and without. He is invisible while residing within the heart but ever visible through His energies that pervade the existence. Therefore the devotee takes to chanting the name of the Lord more than any other practice. This name is the very sound vibration representation of the Absolute Truth. The immature transcendentalist is eager to always see God, but hearing is just as important a sense as seeing. The sound vibrations found within the sacred mantra, “Hare Krishna Hare Krishna, Krishna Krishna, Hare Hare, Hare Rama Hare Rama, Rama Rama, Hare Hare”, allow for God to be heard. This kind of hearing is the most effective at altering consciousness, which in turn keeps the divine vision permanently within the mind.
The impersonalist philosopher and the dedicated servant of the invisible aspect of the Supreme Truth will view the chanting process and the outward worship offered in temples as being reserved for the neophyte level, akin to the training wheels portion of learning to ride a bike. The dedicated servant at the temple, who regularly views the deity, will have a better understanding of the Supreme Lord’s personal features and His grand nature, but they may not understand that the deity also lives outside of the temple, within the hearts of every living being and also within every atom. The holy name, however, is so powerful that it automatically brings about recognition to man’s best ability of the Supreme Lord’s wonderful nature and His supreme power.
For the devotee who has given their life over to chanting the holy name, devotion to God can be likened to a life-giving herb to the dying man, the essence of existence. Without this dedicated service, the humble sage would be left to ponder over what God might be, what He might look like, and whether or not He is even a person. Through these doubts the loving energy of the soul would go untapped. On the flip side, those who do practice bhakti-yoga, ordevotional service, can never run out of ways to describe the transcendental features of their beloved.
rain cloudIn the above quoted verse from the Dohavali, Goswami Tulsidas compares devotion to Rama - a name for the Supreme Person that describes His ability to provide transcendental pleasure- to be like the rainy season. This comparison shows the acute awareness of his surroundings that Tulsidas, who lived in the medieval period in India, had. In India there is an annual monsoon season that can be taken in different ways depending on your angle of vision. Obviously if it’s raining all the time there will be inconveniences in life, especially relating to travel. As far as food production goes, though, the rainy season is the most important time of the year. Without sufficient water, grains could not grow, and life on earth could not continue. Therefore the rain completes the cycle of life; it is vital for man’s existence.
The two months that make up the rainy season serve as the most auspicious and anticipated time for the crops on the field. Similarly, the two syllables in Rama’s name serve as the greatest boon to the grains that are the devotees. This wonderful comparison is very intricate and can be studied and appreciated on so many levels. The first requirement in bhakti is that one turn their back on material attachment. Under the animalistic mindset inherited at the time of birth, man takes himself to be the enjoyer of activities; therefore life becomes a frantic chase to hoard as many resources and delights as possible. Since every other living entity has an equal right to God’s property and the pursuit of sense gratification, collisions will surely result. Moreover, since man is limited in his capabilities, he will not be able to succeed in every venture, with the guaranteed delivery of death serving as the most obvious indication of his fallibility. Even the strongest person who has every amenity available to him, who has never suffered defeat, must succumb to the forces of nature at the time of death.
The devotee realizes that life is about realizing the Absolute Truth, for the lower potential for intelligence in the animal species doesn’t allow for a proper inquiry into spiritual matters. Indeed, even the mid-life crisis endured by adult aged human beings gives an indication of the flawed nature of sense gratification and the need to find a higher taste. The crisis towards the middle of life relates totally to the lack of enjoyment resulting from activities which have been chewed over and over again. “Is this all there is to life? Why can’t I find any more happiness? Maybe I’ll try to drastically alter my daily routine or find something brand new to break out of the doldrums.”
Fortunately for the bhakta, this disenchantment has already come, where they have abandoned the desire to repeatedly take part in activities that provide only flickering happiness. The bhakta identifies as a servant more than anything else, for there is service in every activity. Even the most independent and honored person, like the leader of a nation or the owner of a successful business, must take to serving someone else in order to feel pleasure. The leader of the country ensures that the citizens are always happy, and the leader of the company takes stock of their profit margin and the health of the company, seeing to it that the customers are satisfied and willing to part with their hard earned money.
Lord RamaThe bhakta wants their time spent serving the Supreme Lord, and since God may not be physically present before them, other methods of yoga are implemented. Hearing, remembering, worshiping, offering prayers, carrying out orders and other aspects of devotional life keep the bhakta’s mind fixed on the transcendental world. But more than any other tool, reciting the holy name is what keeps the devotees alive. Lord Rama is the Supreme Person in the form of a warrior prince, one who is kind and sweet in every possible way. Rama is an eternal figure, though according to our time calculations He appeared on this earth many thousands of years ago during the Treta Yuga. Tulsidas is especially fond of Shri Rama, for he doesn’t worship God in any other form. Rama is also Vishnu and He is also Krishna, so there is no difference between one who worships these other two forms and one who takes the delight of Queen Kausalya and Maharaja Dasharatha to be the ultimate reservoir of pleasure and strength.
During most of the year the paddy field just lays there in a dormant state. The crops anticipate that time of the year when they will be fed by the rain. And when the rain does pour down, it is all the more appreciated because of the long gap in between feeding times. Similarly, the bhakta has spent many lifetimes on earth in various species forgetting their beloved Lord. Yet the horrors previously endured, the defeats that left them wondering what the point to life was, get forgotten immediately once the downpour of transcendental nectar in the form of Rama’s name comes raining down.
The rain nourishes the field and ensures that the crops will mature to the point that they can meet their life’s destiny, that of serving as food to the hungry. Similarly, the name of Rama, chanted regularly and with pure love and devotion, allows the bhakta to mature to the point that they become completely enveloped in God consciousness. As is so nicely stated in the Bhagavad-gita, anyone who remembers the Supreme Personality of Godhead at the time of death no longer has to suffer through the miseries of material existence. No longer will they have to ponder over what God looks like and why He put us on earth. No longer will there be temporary gains that bear no relation to the dharma of the soul, or its utmost characteristic. No more will the dried up field that is the devotee have to suffer through many months of the year anticipating the steady rain to come down at the proper time to give life. The God conscious soul is transferred immediately to the spiritual sky after death, a place where time and space have no influence.
Lord RamaJust as Rama’s name acts as the life-giving rain to the dried up field, the personal presence of the Supreme Lord, His wonderful vision, and the display of His tremendously blissful sportive exploits keep the devotees in the spiritual sky always infused with transcendental loving emotions, desires to continue their service without interruption and without motivation. How can there be a lack of motivation when there is a fervent desire to serve? In the transcendental realm, there is no such thing as a personal hankering, for the service mentality takes on its true form when the intended beneficiary is Shri Rama. Hanuman proved through his exploits that the servant of Rama becomes the most exalted person in the world. With Rama’s name also come His wife Sita Devi, His younger brother Lakshmana, and His most exalted servant, the powerful and divine Vanara named Hanuman. With this group always residing in the heart, how could the devotee ever perish from starvation? The holy name irrigates the field of devotion, allowing for grains that sustain the entire world full of devotees to mature and take on their full use. Just as the rain completes the cycle of food production, the name of Rama completes the maturation of the devotees into full blown bhava, or transcendental ecstasy.

Three-Dimensional Photonic Crystals Shine



Crystal filling: This illustration shows gallium arsenide (blue) growing around a template to create a three-dimensional photonic crystal.
Credit: NPG/Nature Materials

COMPUTING

Three-Dimensional Photonic Crystals Shine

In work that could improve solar cells and LEDs, researchers have, for the first time, made practical working devices out of three-dimensional photonic crystals.
  • BY KATHERINE BOURZAC
For the first time, researchers have made high-quality three-dimensional photonic crystals and used them to make a highly efficient light-emitting diode (LED). Three-dimensional photonic crystals promise to boost the performance of just about any optical device, be it a display, a solar cell, or an efficient lightbulb—but until now, no one had been able to make them using commercially viable methods or workable materials. Researchers at the University of Illinois at Urbana-Champaign are now working on solar cells based on the structures.
Photonic crystals can control the absorption, emission, and movement of light in a very precise way based on their structure. They've been a hot area of research since the late 1980s. So far, it's only been practical to make flat, two-dimensional photonic crystals. These control the movement of light very well in two dimensions, but not perfectly in the third. Still, they've been very successful. A company called Luxtera, for example, has developed ways of building photonic-crystal-based optical interconnects directly onto computer chips. Bringing optical signals closer to computer processors helps speed data transmission, and using photonic crystals helps keep the size of these links compact. Luminus has focused on LEDs, for which the crystals help improve light output, making these devices brighter and more power-efficient.
However, three-dimensional photonic crystals would make even better optical devices. "The key advantage is, you can really control the propagation of light in all dimensions," says Paul Braun, professor of materials science and engineering at the University of Illinois. Braun is leading the work on three-dimensional photonic crystals, and his group is also working on making solar cells from the crystals.
Making these structures is tricky. Photonic crystal structures vary, but they're often made by drilling nanoscale holes, rods, and other features into a material. Patterning a flat slab of material with the necessary nanoscale structures to make a two-dimensional photonic crystal is a relatively simple process. It's far more difficult to get that kind of patterning into a thick chunk of material to make a three-dimensional structure without degrading the material. And the kinds of photonic crystals that are most useful—those that can actively convert between electrical signals and optical ones, in addition to precisely manipulating the flow of light—are the hardest to make because material flaws are introduced during the process. This light-to-electricity and back conversion is critical in LEDs, solar cells, and optical data interconnects for computing.
The University of Illinois group made high-quality three-dimensional photonic crystals by growing them on a template, from the bottom up, rather than by trying to introduce the nanoscale patterns into hunks of material. The researchers start by making the template, stacks of packed nanoscale spheres. They then put the template inside a vapor-deposition chamber and flow in a series of gases containing gallium and arsenide. The materials get deposited onto the template and grow around it. It's like filling up a box of ping-pong balls with water: the material that's flowed in fills the spaces between the spheres. Then they chemically remove the spheres, leaving behind a three-dimensional photonic crystal—a hunk of crystalline gallium arsenide that's riddled with nanoscale holes.
Gallium arsenide is used to make optical devices such as photodetectors, but making it into three-dimensional photonic crystals has not been possible before. Not only were the Illinois researchers able to make a three-dimensional photonic crystal out of the material, they were also able to use it to make an LED that's driven by an electrical current.
"I've been waiting a long time for someone to accomplish what [the Illinois group] has accomplished," says Eli Yablanovitch, a professor of electrical engineering and computer science at the University of California, Berkeley. In the late 1980s, Yablanovitch did some of the foundational work on photonic crystals, advancing the idea that certain designs can emit light in a very controlled way that's useful for LEDs.
Yablanovitch says it's difficult to predict what will result from this work, and when, because no one has made practical three-dimensional photonic crystals before. "Some of the most compelling applications are already being filled by two-dimensional photonic crystals," he says. If it becomes as easy to make three-dimensional photonic crystals as it is to make their flat counterparts already in products, they would always be the first choice, says Yablanovitch.
The technology is probably still several years away from commercialization, says Braun

A hot species for cool structures: complex proteins in 3D, thanks to simple heat-loving fungus



A fungus that lives at extremely high temperatures could help understand structures within our own cells.
Scientists at the European Molecular Biology Laboratory (EMBL) and Heidelberg University, both in Heidelberg, Germany, were the first to sequence and analyse the genome of a heat-loving fungus, and used that information to determine the long sought 3-dimensional structure of the inner ring of the nuclear pore. The study was published today in Cell.
Model of the inner ring (green) of the nuclear pore, showing its components. Credit: Heidelberg University Center of Biochemistry.
The fungus Chaetomium thermophilum lives in soil, dung and compost heaps, at temperatures up to 60ºC. This means its proteins – including some which are very similar to our own – have to be very stable, and the Heidelberg scientists saw this stability as an advantage.
“There are a number of structures that we couldn’t study before, because they are too unstable in organisms that live at more moderate temperatures,” explains Peer Bork, who led the genome analysis at EMBL. “Now with this heat-loving fungus, we can.”
The scientists compared the fungus’ genome and proteome to those of other eukaryotes – organisms whose cells have a nucleus – and identified the proteins that make up the innermost ring of the nuclear pore, a channel that controls what enters and exits a cell’s nucleus. Having identified the relevant building blocks, the scientists determined the complex 3D structure of that inner ring for the first time.
“This work shows the power of interdisciplinary collaborations,” says Ed Hurt, who led the structural and biochemical analyses at Heidelberg University: “the nuclear pore is an intricate biological puzzle, but by combining bioinformatics with biochemistry and structural biology, we were able to solve this piece of it for the first time.”
The scientists have made C. thermophilum’s genome and proteome publicly available, and are confident that these will prove valuable for studying other eukaryotic structures and their interactions, as well as general adaptations to life in hot places. Such knowledge could potentially lead to new biotechnology applications.
Reference
Amlacher, S., Sarges, P., Flemming, D., van Noort, V., Kunze, R., Devos, D.P., Arumugam, M., Bork, P. & Hurt, E. Insight into Structure and Assembly of the Nuclear Pore Complex by Utilizing the Genome of a Eukaryotic Thermophile. Cell, 22 July 2011.