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May 3, 2006, 0:46 AM CT

World-Leading Microscope Shows More Detail

World-Leading Microscope Shows More Detail The new microscope in action
unique 3-dimensional microscope that works in a new way is giving unprecedented insight into microscopic internal structure and chemical composition. It is revealing how materials are affected, over time, by changes in temperature, humidity, weight load and other conditions.

The device could lead to advances in a range of areas, such as healthcare (in furthering, for instance, the understanding of conditions such as osteoporosis), the development of better construction materials, improved oil extraction methods and even the study of fossils.

Like a number of other microscopes, the new microscope harnesses X-rays to provide information about an object's internal structure down to micron scale. (A micron is a millionth of a metre.) What makes it unique, however, is its innovative use of a technique called 'time delay integration', which enables it to generate much better images of larger objects than any other device. This means that microscopic structure can be studied with greater accuracy.

With EPSRC funding, a multi-disciplinary team drawn from six UK universities has been developing and utilising the microscope, which, although similar to the CT scanners used in healthcare, can view things in much greater detail.

X-ray microscopes can produce 3-d internal pictures of an object by taking a large number of 2-d images from different angles - this is known as X-ray microtomography. However, the new microscope's combining of this technique with time delay integration is completely unique. Through averaging out imperfections in the image across all pixels, this approach enables the microscope to produce clearer and bigger pictures than previously possible (see 'Notes for Editors').........

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May 1, 2006, 0:00 AM CT

Secrets Of Fossil Galaxy Clusters

Secrets Of Fossil Galaxy Clusters

Taking advantage of the high sensitivity of ESA's XMM-Newton and the sharp vision of NASA's Chandra X-Ray space observatories, astronomers have studied the behaviour of massive fossil galaxy clusters, trying to find out how they find the time to form.

Many galaxies reside in galaxy groups, where they experience close encounters with their neighbours and interact gravitationally with the dark matter - mass which permeates the whole intergalactic space but is not directly visible because it doesn't emit radiation.

These interactions cause large galaxies to spiral slowly towards the centre of the group, where they can merge to form a single giant central galaxy, which progressively swallows all its neighbours.

If this process runs to completion, and no new galaxies fall into the group, then the result is an object dubbed a 'fossil group', in which almost all the stars are collected into a single giant galaxy, which sits at the centre of a group-sized dark matter halo. The presence of this halo can be inferred from the presence of extensive hot gas, which fills the gravitational potential wells of many groups and emits X-rays.

A group of international astronomers studied in detail the physical features of the most massive and hot known fossil group, with the main aim to solve a puzzle and understand the formation of massive fossils. In fact, according to simple theoretical models, they simply could not have formed in the time available to them!........

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April 30, 2006, 11:50 PM CT

A Biosensor Layered Like Lasagna

A Biosensor Layered Like Lasagna A polymer, here labeled PDDA, clings to a carbon nanotube of opposite charge, and an enzyme, GOX, does the same with the polymer. The steps can be repeated to build up a biosensor's layers, enzyme count and sensitivity. Credit: DOE/Pacific Northwest National Laboratory
In a mixing of pasta metaphors, Pacific Northwest National Laboratory researchers have used electrostatic attraction to layer reactive biological molecules lasagna-like around spaghetti-like carbon nanotubes.

This configuration can accommodate a wide range of applications, from ultra-precise blood-sugar monitoring to infectious-agent detection, said Yuehe Lin, who led the research at the Department of Energy campus' W.R. Wiley Environmental Molecular Sciences Laboratory.

The technique, described in the current (April) Journal of Nanoscience and Nanotechnology, enables enzymes, with the help of a long, noodle-like polymer molecule, to self-assemble layer-by-layer on a single carbon nanotube.

Lin and co-author Guodong Liu, a postdoctoral fellow in Lin's group, coaxed electrostatic clinginess in a polymer and an oppositely charged protein-enzyme, in this case glucose oxidase, which reacts in the presence of blood sugar. The catalyzed products from the reaction ping the carbon nanotube; if the tube is connected to an electrode, the tube will carry a signal that corresponds precisely with the amount of glucose detected. The first polymer binds to the carbon nanotube. Enzymes are attracted to the polymer, leaving an outer layer for the next polymer of opposite charge to cling to, and so on.........

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April 29, 2006, 9:33 AM CT

Use Of Information Technology In Hospitals

Use Of Information Technology In Hospitals
Although information technology is now common in many hospitals and biomedical laboratories, in the 1950s only a small number of researchers imagined its enormous potential. In 1967, supported by NCRR, doctor Homer Warner led a seminal effort that created one of the first bioinformatics systems. This work has influenced patient care, increased safety, and produced cost-effective service in hospitals around the nation. Today, NCRR continues its support of clinical bioinformatics as an integral component of the new Clinical and Translational Science Awards.

Clinical application of bioinformatics began in earnest when the University of Utah installed a state-of-the-art computer in the early 1960s. Back then, Warner became intrigued by the possibility of using this new technology with patients at the Latter-day Saints (LDS) Hospital. It wasn't long before he gained access to the giant machine and began writing programs to study coronary blood flow. Because the computer was only available at night, he set a cot beside it to sleep on while the computer slowly crunched numbers.

One of the central questions in his mind was how to obtain around-the-clock physiological information from post-operative cardiac patients. Warner resolved this problem by inserting catheters into patients' arteries. When connected through a computer, the apparatus calculated stroke volume, heart rate, cardiac output, and blood pressure on demand. Resulting data were displayed on the screen of an oscilloscope, and three small lights alerted nurses of abnormal vital signs that could lead to complications. This was one of the first uses of computers for preemptive patient monitoring, a concept now propagated through nearly every intensive care unit.........

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April 28, 2006, 0:08 AM CT

Software Allows Neighbors To Improve Internet Access

Software Allows Neighbors To Improve Internet Access
Computer researchers at the University of Illinois at Urbana-Champaign have developed software that enables the sharing of high-speed wireless connections without compromising security or privacy. The software can improve Internet connectivity in residential areas at no additional cost.

"Significantly improved speed and the 'always on' feature of wireless routers have been driving the rapid spread of broadband Internet access in a number of residential areas," said Haiyun Luo, a professor of computer science at the University of Illinois at Urbana-Champaign. "More than 56 percent of homes in the United States already have Internet access, and more than half of those homes are using Wi-Fi wireless home networks."

A typical residential user accesses his broadband home connection about 12 to 15 hours per week, Luo said. "So, while the Internet connection is always on, most of the time it sits idle." Luo would like to see that idleness put to good use by benefiting other users, and he and graduate student Nathanael Thompson came up with a way to do it.

Luo and Thompson have developed a software framework called PERM (Practical End-host collaborative Residential Multihoming) that allows neighbors to pool their Internet access and thereby improve both performance and resilience.........

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April 28, 2006, 0:04 AM CT

Software For The Next Generation Of Net Surfers

Software For The Next Generation Of Net Surfers
With an estimated 12 billion websites online, it's not always easy finding the exact site you want. However, University of Alberta computer researchers have developed software they believe will make surfing the Web faster and easier.

The software uses machine learning technology to predict the information needs of web surfers by refining search engine queries and filtering out irrelevant search results based on surfers' past surfing results.

WebIC is a "complete Web recommendation system" says one of its creators, Tingshao Zhu, a doctoral student in the U of A Department of Computing Science. "Surfing the Web can be time-consuming and frustrating, but this product can simplify things a lot".

The software can be incorporated with search engines (e.g. Google) or be downloaded directly onto to individual computers. It works by anticipating users' info needs; users can click on an icon that leads to suggested sites the user may be looking for, which is a step beyond the usual search engine index retrievals. It can also be used to filter emails and find specific articles online (not simply direct you to related sites).

"On most search engines the order of the keyed words is very important as the associations are made sequentially," Zhu said. "But our software uses machine learning to transfer human inquiries into the type of inquiries a computer can fully understand. Our system can point you directly to the sites that you want and not just to sites that are correlation to your keyed words".........

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April 27, 2006, 11:57 PM CT

Spectacular View Of Ongoing Comet Breakup

Spectacular View Of Ongoing Comet Breakup
Hubble Space Telescope is providing astronomers with extraordinary views of comet 73P/Schwassmann-Wachmann 3 as it disintegrates before our eyes. Recent Hubble images have uncovered many more fragments than have been reported by ground-based observers. These observations provide an unprecedented opportunity to study the demise of a comet nucleus.

Amateur and professional astronomers around the world have been tracking the spectacular disintegration of 73P/Schwassmann-Wachmann 3 for years. As it plummets towards a close encounter with the Sun, swinging round the Sun on 7 June and heading away to begin another loop round the Solar System, the comet will pass the Earth on 12 May, at a distance of 11.7 million kilometres, or 30 times the distance between Earth and the Moon.

The comet currently comprises a chain of over 33 separate fragments, named alphabetically, and stretching across several degrees on the sky (the Sun and Moon each have an apparent diameter of about 1/2 a degree). Ground-based observers have noted dramatic brightening events associated with some of the fragments indicating that they are continuing to break up and that some may disappear altogether.

Hubble caught two of the fragments, B and G, shortly after major outbursts in activity. The resulting images reveal that an amazing process of hierarchical destruction is taking place, in which the larger fragments are continuing to break up into smaller chunks. Several dozen "mini-fragments" are to be found trailing behind each main fragment, probably associated with the ejection of house-sized chunks of surface material that can only be detected in these very high-resolution Hubble images.........

Posted by: Edwin      Permalink         Source


April 27, 2006, 11:55 PM CT

Unexpected Plasmonic Discovery

Unexpected Plasmonic Discovery
Frequently, the unexpected results in science are the most exciting. That's the case with the latest findings from the lab of Rice University's electrical engineer Daniel Mittleman, who was trying to find new ways to use terahertz energy, or T-rays, for chemical sensing when he noticed a strange tendency of the signals to travel slower if they were sent down smaller metal wires.

Mittleman and graduate student Kanglin Wang reported their findings in the April 21 issue of Physical Review Letters. Their explanation for the odd phenomenon arises from the unique way that T-rays interact with the sea of electrons flowing across the surface of the metal wire.

"A similar variation in wave velocity is well-documented for higher frequency radiation in the visible portion of the spectrum, but this was a real puzzle because no one had predicted it for such low frequencies," said Mittleman, associate professor of electrical and computer engineering.

Mittleman and Wang discovered the phenomenon during follow-up experiments to last year's groundbreaking development of the first T-ray wire waveguides. Their discovery that T-rays propogate down bare metal wires has allowed them to make T-ray endoscopes that can carry T-rays around corners and into tight places - like pipes and metal containers - where it hasn't been feasible to place a T-ray generator. Mittleman hopes to use the technique to design a new class of chemical sensors that port security officers can use to quickly determine whether explosives are hidden inside shipping containers.........

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April 26, 2006, 8:09 PM CT

The Art of Asteroid Avoidance

The Art of Asteroid Avoidance Just what can a little spacecraft do to deflect an asteroid - a lot say some scientists. Credit: SpaceDaily
Col. Gen. Vladimir Popovkin, commander of the Russian Military Space Forces, told a news conference Friday that the national satellite network lacked a spacecraft capable of preventing an asteroid strike.

He also said chances of such a collision were infinitely small, and it was inexpedient to spend huge sums on neutralizing this unlikely threat. Still, the general might be underestimating the scale of the asteroid threat.

Over the last few decades there has been a great deal of debate about the level of danger posed by impacts from asteroids and comets. It appears the world needs to take the threat of asteroid strikes a lot more seriously.

Astronomers have already spotted about 800 asteroids, solid rocky celestial bodies, with a diameter of over 1,000 meters (3,250 feet) moving along circumsolar elliptical orbits. However, there may be as a number of as 2,000 large asteroids, and some 135,000 rocks with a diameter of 100 meters (325 feet) and more.

It should be noted that asteroid orbits are unstable and tend to change under the influence of gravitational fields of the terrestrial planets - Mercury, Venus, Earth and Mars.

An asteroid, which flashed past our planet at a distance of 5 million kilometers (3.1 million miles) in November 1996, returned in September 2004 and flew by just 1.5 million kilometers (930,000 miles) from Earth's surface. In March 1989, a 300 meter (975 foot) asteroid crossed the terrestrial orbit and missed the Earth by just six hours. Astronomers spotted the rock only when it was receding into space.........

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April 26, 2006, 8:03 PM CT

Micro-pump Is Cool Idea For Future Computer Chips

Micro-pump Is Cool Idea For Future Computer Chips
Engineers at Purdue University have developed a tiny "micro-pump" cooling device small enough to fit on a computer chip that circulates coolant through channels etched into the chip.

Innovative cooling systems will be needed for future computer chips that will generate more heat than current technology, and this extra heating could damage electronic devices or hinder performance, said Suresh Garimella, a professor of mechanical engineering.

The new device has been integrated onto a silicon chip that is about 1 centimeter square, or roughly one-sixth of a square inch. The technology is an example of a microelectromechanical system, or MEMS, a tiny mechanical device fabricated using methods generally associated with microelectronics.

"Because it's a MEMS pump, we were able to integrate the entire cooling system right onto a chip," Garimella said. "The most innovative part of the technology is the micro-pump".

An article about the cooling device will appear in the recent issue of Electronics Cooling magazine. The article was written by doctoral student Brian D. Iverson, Garimella and former doctoral student Vishal Singhal, who recently graduated and co-founded Thorrn Micro Technologies Inc., in Redwood City, Calif.

Chips in today's computers are cooled primarily with an assembly containing conventional fans and "heat sinks," or metal plates containing fins to dissipate heat. But because chips a decade from now will likely contain upwards of 100 times more transistors and other devices, they will generate far more heat than chips currently in use, Garimella said.........

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