Better Vision, With a Telescope Inside the Eye

A TINY glass telescope, the size of a pea, has been successfully implanted in the eyes of people with severely damaged retinas, helping them to read, watch television and better see familiar faces.

The new device is for people with an irreversible, advanced form of macular degeneration in which a blind spot develops in the central vision of both eyes.

In a brief, outpatient procedure, a corneal specialist implants the mini-telescope in one eye in place of its natural lens. The telescope magnifies images on the retina, extending them so they fall on healthy cells outside the damaged macula, said Allen W. Hill, chief executive of VisionCare Ophthalmic Technologies in Saratoga, Calif., the implant’s maker.

In March, an advisory panel to the Food and Drug Administration unanimously recommended approval of the device. VisionCare says it expects the F.D.A. to give its O.K. later this year. The device has already been approved for use in Europe.

The implanted telescope holds much promise for patients, typically elderly, who suffer from end-stage, age-related macular degeneration, or A.M.D., said Janet P. Szlyk, a member of the advisory panel. Dr. Szlyk is executive director of the Chicago Lighthouse for People Who Are Blind or Visually Impaired, a social services agency.

The device does not cure the disease, but it does improve visual acuity, she said. For example, a person who might usually see a blur when looking at a friend’s face might, with the help of the magnified image, see a blur only in the area of the person’s nose or mouth.

“People can use it to recognize faces in a social setting,” she said. ‘That’s a huge advance.”

The telescope is implanted in one eye for jobs like reading and facial recognition. The other eye, unaltered, is used for peripheral vision during other activities like walking. After implantation, extensive therapy is crucial, she said, to learn to deal with the different abilities of the eyes.

Ruth A. Boocks, 86, of Alpharetta, Ga., who received an implant of the device in March 2003 during clinical trials, said her brain learned to adapt quickly. Mrs. Boocks uses her new visual abilities in various ways — for instance, to read e-mail and the messages that scroll across the bottom of the screen when she’s watching television. “My goal was to read to the bottom of the eye charts,” she said. “But I didn’t quite make it.” (She has gotten to the third line from the bottom.)

“I feel like a young woman,” she added. “It’s opened a lot of opportunities for me.”

Henry L. Hudson, a retina specialist in Tucson, Ariz., and lead author of two papers on the telescope published in peer-reviewed journals, said the device was not for everyone with A.M.D. “Maybe only 20 out of every 100 candidates will get the telescope,” he said. “They may not be eligible because of the shape of their eyes,” or they may have another problem, like maintaining balance, that precludes their selection, he added.

After F.D.A. approval, VisionCare will apply to Medicare to cover the device, Mr. Hill said. “We anticipate that it will be seen as a covered benefit for the improvement of visual acuity,” he said.

The price of the device has not been set. Current tools for ameliorating low-vision problems, like glasses fitted with telescopes or reading machines, are typically not covered by insurance.

Dr. Bruce P. Rosenthal is chief of low-vision programs at Lighthouse International in New York City, where telescopes mounted on eyeglass frames, for instance, might be prescribed for people with A.M.D. to help them watch a sports event. He said that patients might be as well served by these glasses as by the new implants, and that he hoped long-term studies would compare the benefits of the two approaches.

“Even though studies on the implants have reported minimal complications, there can be complications when you are inserting anything in the eye,” he said. “Even routine cataract surgery can lead to loss of vision.”

Dr. Rosenthal said the implanted telescope might be beneficial for some patients, “especially if they don’t want other people to know they are visually impaired.” Telescopes mounted on eyeglasses bulge outward, often extending an inch or so beyond the frames.

But he is concerned that people using implants might have trouble with balance. “There is a potential for falling when a person has a big image from one eye and a normal-sized image from the other,” he said.

DURING trials of the device, there was no increase in the incidence of falls among participants, Dr. Hudson said. More than 200 patients received implants in the study, and the effects have been tracked in the group for the past five years.

“The vast majority of the patients have been able to adapt to the new state,” using one eye for ambulating and the other for reading, facial recognition and similar chores, he said. “The average patient goes from legally blind to being able to read large-print books.”

For fish, it’s the more the merrier

Study: Single and pairs of fish in aquariums are more stressed than groups

Watching a fish or two swim around a tank can be relaxing for you — but surprisingly stressful for the fish.

A new study found that common aquarium fish fight more and act less like themselves when they're lonely. Just as people choose to squeeze into a crowded nightclub rather than roam around an empty bar, it seems, certain fish prefer to have lots of companions.

It was the first study to look at the well-being of fish in home aquariums, and the results suggest that we may owe more to our fish than just keeping them from going belly-up.

India plans hot chilli grenades

Indian defence scientists are planning to put one of the world's hottest chilli powders into hand grenades.

They say the devices will be used to control rioters and in counter-insurgency operations.

Researchers say the idea is to replace explosives in small hand grenades with a certain variety of red chilli to immobilise people without killing them.

The chilli, known as Bhut Jolokia, is said to be 1,000 times hotter than commonly used kitchen chilli.

Scientists at India's Defence Research and Development Organisation (DRDO) are quoted as saying the potent chilli will be used as a food additive for troops operating in cold conditions.

And the powder will also be spread on the fences around army barracks in the hope the strong smell will keep out animals.

Other forms of pepper spray are commonly used for crowd control in many parts of the world.

Bacteria in Air So Numerous They Form Clouds

To read the article click here

Some theories of Genitics

Vapour and Fluid Theories of Genetics
Early Greek philosophers speculated that the hereditary informations of parents existed in the form of vapours of fluids. Pythagoras (500 B. C.) speculated that a moist "vapour" descended from the brain, nerves and other body organs of the male during the coitus and from these vapours an embryo was formed in the uterus of the female. According to him, the male transmitted all the characters of the embryo and the female does not. However, another Greek philosopher of the same age, Empedocles thought that both parents contributed equally to the embryo and each parent produces a "semen" which arises directly from various body parts.
After 200 years, another Greek philosopher Aristotle forwarded a highly imaginative speculation that the seman of the male had certain 'vitalizing' or "dynamic" effect and it was supposed to be highly purified blood. According to him, the female furnished the inert building material, while the male gives the motion and new life to the material.


Particulate inheritance theory
The theory of particulate inheritance is an idea that originated with Mendelian theorists (or by Mendel himself) stating that characteristics can be passed from generation to generation through "discrete particles" (which meant genes). These particles can keep their ability to be expressed while not always appearing in descending generation.
Early in the 19th century, scientists had already recognized that Earth has been inhabited by living creatures for a very long time. On the other hand, they did not understand what mechanisms actually drove biological diversity. They also did not understand how physical traits are inherited from one generation to the next. Blending inheritance was the common ideal at the time, but was later discredited by the experiments of Gregor Mendel. Mendel proposed the theory of particulate inheritance by using pea plants (Pisum sativum) to explain how variation can be inherited and maintained over time.


Preformation theory
The Preformation theory states that "knowledge is possible only because God has endowed humans with certain innate ideas along with dispositions or aptitudes in certain ways." This was recognized by Immanuel Kant as an alternative to his theory regarding the categories of understanding and their source.
According to Kant's view the aptitudes are both innate and a priori not given by a creator. Contrary to Kant's position, the preformation theory avoids skepticism about the nature of the noumenal world (Kant believed that the real world is unknowable). It does so by claiming that the rational structures of the human mind are similar to the rational order of the real world because both are created by God to work together, and this similarity makes the attaining of accurate knowledge about the real world possible.


Germ plasm theory
Germ plasm or polar plasm is a zone found in the cytoplasm of the egg cells of some model organisms (such as Caenorhabditis elegans, Drosophila melanogaster, Xenopus laevis), which contains determinants that will give rise to the germ cell lineage. As the zygote undergoes mitotic divisions the germ plasm is ultimately restricted to a few cells of the embryo, these germ cells then migrate to the gonads.
The germ plasm theory is a hypothesis concerning the ability to become germ cells, which is now proven wrong. The term germ plasm was first used by the German biologist August Weismann (b.1834-d.1914) to describe a component of germ cells that he proposed were responsible for heredity, roughly equatable to our modern understanding of DNA. August Weismann formulated the now defunct germ plasm theory in 1893, in which he stated that the germ plasm was the essential nuclear part of germ cells, that it remained qualitatively unchanged from the zygote (in contrast with somatic cells) and was responsible for heredity. In other words it states that a gene's determination was sealed as it, and each of its offspring received fewer and fewer genes from what he called the "germ plasm." (That there is only a set "amount" of "germ plasm" (what we know as genes) and that it was gradually divided amongst the offspring). Cases such as Dolly (the famous cloned ewe) which, via somatic cell nuclear transfer, proved that adult cells retain a complete--as opposed to Weissman's increasingly determined gradual loss of genetic information--set of information; finally putting Weismann's theory to rest.