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Those blinded by brain injury may still ‘see’
Prof Yash
Pal Prof Yash Pal When milk boils it comes out of the vessel, but when water boils, it never comes out. Why? Is there any other liquid that behaves like milk on boiling?
Trends |
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Computer helps search ancient texts
Researchers in Israel say they have developed a computer programme that can decipher previously unreadable ancient texts and possibly lead the way to a Google-like search engine for historical documents.
The programme uses a pattern recognition algorithm similar to those law enforcement agencies have adopted to identify and compare fingerprints. But in this case, the programme identifies letters, words and even handwriting styles, saving historians and liturgists hours of sitting and studying each manuscript. By recognising such patterns, the computer can recreate with high accuracy portions of texts that faded over time or those written over by later scribes, said Itay Bar-Yosef, one of the researchers from Ben-Gurion University of the Negev. “The more texts the programme analyses, the smarter and more accurate it gets,” Bar-Yosef said. The computer works with digital copies of the texts, assigning number values to each pixel of writing depending on how dark it is. It separates the writing from the background and then identifies individual lines, letters and words. It also analyses the handwriting and writing style, so it can “fill in the blanks” of smeared or faded characters that are otherwise indiscernible, Bar-Yosef said. The team has focused their work on ancient Hebrew texts, but they say it can be used with other languages, as well. The team published its work, which is being further developed, most recently in the academic journal Pattern Recognition due out in December but already available online. A programme for all academics could be ready in two years, Bar-Yosef said. And as libraries across the world move to digitise their collections, they say the programme can drive an engine to search instantaneously any digital database of handwritten documents. Uri Ehrlich, an expert in ancient prayer texts who works with Bar-Yosef’s team of computer scientists, said that with the help of the programme, years of research could be done within a matter of minutes. “When enough texts have been digitised, it will manage to combine fragments of books that have been scattered all over the world,” Ehrlich said.
— Reuters
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Those blinded by brain injury may still ‘see’
We rarely knock over a plateful of food or glass of orange juice as we reach for our morning cup of coffee.
A new study by the University of Western Ontario (UWO) has helped unlock the mystery of how our brain allows us to avoid these undesired objects. The study was led by Mel Goodale, professor in visual neuroscience, Chris Striemer and colleagues in UWO psychology department. “We automatically choose a path for our hand that avoids hitting any obstacles that may be in the way,” says
Goodale. “Every day, we perform hundreds of actions of this sort without giving a moment’s thought as to how we accomplish these deceptively simple tasks.” In the study, a patient who had become completely blind on his left side following a stroke to the main visual area of the brain was asked to avoid obstacles as he reached out to touch a target in his right - or ‘good’ - visual field. Not surprisingly, he was able to avoid them as any normal-sighted individual would. However, when obstacles were placed on his blind side, he was still able to avoid them - even though he never reported having seen them. “The patient’s behaviour shows he is sensitive to the location of obstacles he is completely unaware of,” Striemer says. “The patient seemed to be as surprised as we were that he could respond to these ‘unseen’ obstacles,” Goodale adds. These findings provide compelling evidence for the idea that obstacle avoidance depends on ancient visual pathways in the brain that appear to bypass the main visual areas that allow us to perceive the world. Thus, even when the part of the brain that gives us our visual experience is damaged, other parts of the brain still maintain a limited ability to use visual information from the eyes to control skilled movements of the limbs. Additional experiments in Goodale’s lab at the world-renowned Centre for Brain & Mind have shown that these primitive visual pathways work only in real-time and do not have access to memories, even of the short-term variety. As an example, they provided an obstacle in the patient’s blind field but delayed his reach by two seconds. With this short delay, he no longer showed any sensitivity to the object’s location, said an UWO release. These results have been published in the current issue of the Proceedings of the National Academy of Sciences.
—Indo-Asian News Service |
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This Universe
When milk boils it comes out of the vessel, but when water boils, it never comes out. Why? Is there any other liquid that behaves like milk on boiling?
I had earlier answered such a question. What is additional in your question is the query whether there is another liquid I know which behaves the same way upon heating. My answer is that I do not know.
Part of the reason is that milk is not a pure liquid. It is a suspension of several colloidal substances in water. The question I received five years ago and the answer given is copied below: When we boil milk on direct flame in a vessel it tends to rise fast and spills out when boiling begins. But milk can also be heated in a pot that is placed in another vessel in which water is being heated to boiling point. It is found in this case milk can be boiled but it does not rise up and overflow. Please explain the reason for this difference. Milk is not a simple liquid. It contains lot of things. It contains tiny globules of fat and casein (stuff that is found in cheese). They are not dissolved in water —they are suspended. On heating there is separation of constituents. Some of the stuff, such as cream, floats up. Some of it on the surface sticks to the sides of the vessel. After a while a membrane-like film begins to form on the surface, containing cream and casein. When the boiling starts all the energy of the burner is used in converting water into steam. The pressure below the membranes suddenly increases and the rising bubbles of steam make the milk overflow and spill out. In the interesting alternative of heating milk that you have suggested there is no extra input of heat for causing vigorous conversion of water into steam after the milk has reached the point of boiling; the temperature around the vessel is the same even when the water in the outer vessel is boiling.
This must be the reason for the graceful residence of milk close to boiling point.
Readers wanting to ask Prof Yash Pal a question can e-mail him at
palyash.pal@gmail.com |
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Trends
CANBERRA: Australia’s Great Barrier Reef, the world’s largest living organism, is under grave threat from climate warming and coastal development, and its prospects of survival are “poor,” a major new report found on Wednesday.
While the World Heritage-protected site, which sprawls for more than 3,45,000 square km off Australia’s east coast, is in a better position than most other reefs globally, the risk of its destruction was mounting.
CAPE CANAVERAL, Florida: Getting humans to Mars will require medical research
on the International Space Station through at least 2020, said the programme’s
lead scientist, presenting a time frame five years beyond NASA’s current budget forecast. Extending the life of the station, a $100 billion project of 16 nations that is nearing completion after more than a decade of construction, was a surprise finding of the presidential panel reviewing the US human space
programme.
Workers checking the Kepler spacecraft as it is lifted for weighing at the Hazardous Processing Facility at Astrotech in Titusville, Florida. —AFP U.N. chief calls for urgent action on climate
LONGYEARBYEN, Svalbard: United Nations Secretary-General Ban Ki-moon called on world leaders on Monday to take urgent action to combat climate change for the sake of “the future of humanity.” Ban, on a tour of Svalbard, the remote Norwegian-controlled Arctic Archipelago, said the region might have no ice within 30 years if present climate trends persisted.
Edwards completes enrolment in valve study
CHICAGO: Edwards Lifesciences Corp said on Monday it has finished enrolling patients in a study of its Sapien aortic heart valve that is threaded into place with a catheter without the need for open-heart surgery. Enrolment has been completed in both arms of the 1,040-patient Partner clinical Indonesian satellite misses orbit
BEIJING: An Indonesian communications satellite launched from China failed to enter a preset orbit, state media reported, in another setback in China’s efforts to market its space launch capability. China is rapidly expanding its own space capability and plans to land a vehicle on the moon in 2012.
— Reuters
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Extending space station key to