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Researchers discover second light-sensing system in human eye
2007-12-18 15:57:00
New research on blind subjects has bolstered evidence that the human eye has two separate light-sensing systems — one that perceives the familiar visual signals that allow us to see and a second, separate system that tells our body when it is day or night.Researchers have long known that the eye performed both functions but until recent years it had been thought that both vision and the management of the circadian rhythm that tells us when to be sleepy and when to be alert had been done all at once through the retina’s rods and cones that enable us to see. Beginning in the 1990s, however, research in animals and in healthy human subjects indicated that though vision was handled by the rods and cones, the signals that synchronize our body clock with the sun’s rising and setting are handled through a second system of light-sensitive cells, located at the back of the retina. These cells extend from the back of the eye into the brain’s hypothalamus region, which manages o...
More About: System , Human , Light , Discover

Evolution balances childbearing women
2007-12-18 14:50:00
More flexible spines have developed to change center of gravity By Amy Lavoie FAS Communications When a pregnant woman leans back, and shifts her weight to stand more comfortably, she is performing a motion that for millions of years has helped to compensate for the strain and weight of childbearing on the body. According to a new study from researchers at Harvard University and the University of Texas, Austin, women’s lower spines evolved to be more flexible and supportive than men’s to increase comfort and mobility during pregnancy, and to accommodate the special biology of carrying a baby for nine months while standing on two feet. The study, published in the Dec. 13 issue of Nature, was led by Katherine Whitcome, a postdoctoral researcher in the Department of Anthropology in Harvard’s Faculty of Arts and Sciences, with Daniel Lieberman, professor of anthropology at Harvard, and Liza Shapiro, associate professor of anthropology at the University of Texas, Aus...
More About: Women , Evolution

Nanoscience: Weak Force. Strong Effect.
2007-12-18 14:41:00
he van der Waals force, a weak attractive force, is solely responsible for binding certain organic molecules to metallic surfaces. In a model for organic devices, it is this force alone that binds an organic film to a metallic substrate. This data, recently published in Physical Review Letters, represents the latest findings from a National Research Network (NRN) supported by the Austrian Science Fund FWF. These findings mean that numerous calculation models for the physical interactions between thin films and their carrier materials will need to be revised. Although they fulfil complex functions when used, for example, as computer chips, inorganic semiconductors have a simple construction that greatly limits their application. The same does not apply to semiconductors made of organic materials. Because organic molecules are extremely flexible, they can be used in a whole new range of applications. However, before this advantage can be exploited to the full, scientists need to have ...
More About: Force , Effect , Strong

Protons - Everything Revolves Around Spin
2007-12-18 14:39:00
Current understanding of the spin structure of protons has been summarised in a single book for the first time. The book examines attempts to solve one of the greatest puzzles of physics. Models and experiments to date have been unable to properly explain a fundamental property of protons spin. Published by Dr. Steven Bass as part of an Austrian Science Fund FWF project, the book summarises over 1,000 publications and the results of a global research programme on this phenomenon. Many particles rotate around their own axis like spinning tops. However, unlike spinning tops, this spin has a fundamental influence on the properties of the particle - and therefore on our world. Quantum physical interactions mean that spin is responsible for the magnetic moment of protons, and therefore also the stability of the universe. It is a truly fundamental force. This makes it all the more sur...
More About: Spin , Proto

Guiding the Light
2007-12-18 14:35:00
Pioneering research is shining new light on our understanding of the way we see the world. Optical fibres have now been found to exist in vertebrate eyes, channelling light down their length and delivering it without distortion straight to the cells that 'see'. Incredibly sophisticated in structure and function, the construction of the retina has puzzled researchers ever since the finer structures of the eye were first resolved over 150 years ago: the retina is built the 'wrong' way around. The cells responsible for light sensing are sited at the back of the eye, furthest from the incoming light. An advanced understanding of the 'inverted retina' has now been revealed by Dr Jochen Guck, newly arrived at the Cavendish Laboratory, while working with a team of scientists at the University of Leipzig, Germany. The results of this study have recently been published in PNAS (Franze et al., Müller cells are Living Optical Fibers in the Vertebrate Retina. Proc. Natl. Acad. Sci. ...
More About: Light

Z-shaped incision enhances minimally invasive surgery
2007-12-18 13:43:00
A novel surgical technique allowing doctors to operate on patients by making a Z-shaped incision inside the stomach could potentially replace certain types of conventional surgery in humans, according to Penn State medical researchers who have successfully demonstrated the procedure in pigs.If the technique ultimately proves successful in human trials, researchers say it could circumvent the long painful recovery times and medical complications associated with surgery.The new approach, known as NOTES (natural orifice transluminal endoscopic surgery), involves using a natural opening in the body, in this case the mouth, to advance a flexible video endoscope into the stomach. Using this tube, and the instruments contained within it, doctors currently make a small straight incision in the stomach to gain access to the abdominal cavity and the organs requiring attention."Theoretically, by eliminating body wall wounds with their associated complications and allowing some procedures to be...
More About: Surgery , Urge