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Tuesday, December 8, 2009

Breakthrough Flu Drug Might Already Exist

Fragments of known drugs could lead to a more robust antiviral for H1N1 and other flu variants.

The flu virus is a wily target, constantly mutating to avoid attack from the immune system and from antiviral drugs like Tamiflu. But in research presented Sunday at the annual meeting of the American Society for Cell Biology (ASCB) in San Diego, scientists announced a new method for fighting pandemic influenzas such as H1N1 (swine) and H5N1 (avian).

Structurally sound: The neuraminidase protein of the H1N1 virus is particularly adept at mutating to avoid attack. In this crystal structure, the mutations that allow it to resist Tamiflu and other antiviral drugs are visible as multicolored stick structures.
Credit: Daniel Dadon and Jacob Durrant
The approach involves using massive amount of computer power to simulate never-before-seen conformations of a virus. Using the method, researchers at the University of California at San Diego have not only identified a new molecular target for influenza drugs, they have also found drugs already approved by the U.S. Food and Drug Administration that just might hit the target perfectly.
The target in question is a single, large protein called neuraminidase--one of two major proteins present on the surface of the influenza virus--that allows newly replicated viruses to be released into their host. Because most pandemic versions share the same neuraminidase subtype, N1, the protein is an ideal drug target.
Most molecular imaging or modeling focuses on determining the arrangement of atoms in a molecule's crystal structure--a lengthy, energy-intensive process that provides a precise way to capture the molecule's shape but only in one conformation, frozen at a single moment in time. In contrast, the new "relaxed complex" method models the virus protein molecule in a state that provides a better understanding of how the protein behaves and even revealing conformations that rarely occur.

Wednesday, November 18, 2009

Using CO2 to Extract Geothermal Energy



Carbon dioxide captured from power plants could make geothermal energy more practical.
Carbon dioxide generated by power plants may find a second life as a working fluid to help recover geothermal heat from kilometers underground. Such a system would not only capture the carbon dioxide and keep it out of the atmosphere, it would also be a cost-effective way to use the greenhouse gas to generate new power.

Backers of this as-yet-unproven concept secured a big endorsement and much-needed cash with the U.S. Department of Energy's recent award of $338 million in federal stimulus funds for geothermal energy research. Some $16 million of the funds will be shared by nine carbon dioxide-related projects led by Lawrence Berkeley National Laboratory and other national labs, Sunnyvale, CA-based combinatorial chemistry firm Symyx Technologies, and several U.S. universities.
The idea: Carbon dioxide that's cycled through hot regions kilometers underground can efficiently bring heat to the surface, where it can be used to generate electricity. The likelihood is that the process would leave lots of carbon dioxide underground, and thus out of the atmosphere, according to Symyx project leader and materials scientist Miroslav Petro. "You're sequestering CO₂ and at the same time generating power from it."

Making 3D Maps on the Move

A vehicle uses off-the-shelf components to build 3D maps of an area.





At a robotics conference last week, a vehicle called ROAMS demonstrated a cheap approach to mobile map-making. 

ROAMS (Remotely Operated and Autonomous Mapping System) was created by researchers at the Stevens Institute of Technology in Hoboken, NJ, with funding from the U.S. Army. It uses several existing mapping technologies to build 3D color maps of its surroundings, and it was demonstrated at the 2009 IEEE conference on Technologies for Practical Robot Applications in Woburn, MA last week.
The system uses LIDAR (Light Detection and Ranging), which involves bouncing a laser off a rapidly rotating mirror and measuring how the light bounces back from surrounding surfaces and objects. The same technology is already used to guide autonomous vehicles, to make aerial maps, and in spacecraft landing systems.

An Electronic Clue In The Mystery of DNA Repair



DNA repair machines may home in on the electrical signals created by mutations
Here's a curious puzzle involving DNA molecules. DNA is regularly damaged by ordinary wear and tear and the constant buffeting of ionising radiation. However, cells possess an extraordinary collection of molecular machines such as repair enzymes that rapidly identify the defects and repair them.
The puzzle is how they do it. One idea is that repair enzymes simply float about for long enough and eventually find damaged regions. But the numbers just don't stack up. Genes are usually between 1000 and 1,000,000 base pairs long. By contrast, a typical mutation usually involves just a handful of base pairs. That's just too small to find using a random walk with any reliability. Some other form of active location finding must be going on.
One theory is that mutations change the electrical characteristics of a stretch of DNA and that this creates a signal that repair enzymes can home in on, like electricians locating a break in a circuit. The trouble is that DNA doesn't conduct electricity like a power cable and so it isn't clear how this would work.
Now Arkady Krokhin at the University of North Texas and few buddies have worked out how DNA may do it. The key turns out to be that different regions of DNA have different electrical characteristics. The group has calculated from first principles the way in which charge flows in different regions. They say that in exons--the information carrying parts of genes--the energy spectrum of the molecule allows delocalised electrons to exist. In these areas, charge can flow.

Monday, November 16, 2009

Staying Connected on the Road

Fortunately, mobile connectivity has improved dramatically in the last several years. Whether you are using Wi-Fi or Ethernet, you have many options to choose from.
Hotel Internet
Where hotels used to offer only "data ports" into which you plugged your modem, it's common today for there to be high speed internet or Wi-Fi for no additional charge.
When the internet works, it's a great thing, but sometimes it can be quite spotty. Problems include authentication and wireless access points which are too far away to reach your room. Probably the worst, however, are those systems that intercept all outgoing mail, route it through their server and then restrict the number of outgoing messages you can send in a day. For email driven or business lifestyles, this is unacceptable.
Wi-Fi Hotspots
Hotspots which offer Wi-Fi are everywhere if you have a wireless-capable device. If you have an account with AT&T, for example, you have access to thousands of hotspots across the country, usually in a Starbucks. The convenient thing with these accounts is that you may not have to sign up for a plan; you can usually pay for a day or week's worth of access. Of course, if you plan on using these networks regularly, the plans are more cost effective. If you just have a "connectivity emergency" though, a 24 hours pass can really save the day.
Hotspots are not limited to Starbucks, however. You can quite often find them at libraries, sometimes shopping malls, government facilities and more. Online resources are available to help you find free hotspots. Just search for "free hotspot directory" to find several. Don't limit yourself though; many times these directories are out of date, so continue to check for new hotspots.
Cellular
For the seriously addicted or just serious internet user, cellular technology has recently gotten to the point of being usable and may prove to provide the most flexible option of all. Most major carriers now have high-speed internet options that have much improved coverage and connectivity.
A very popular option is the USB cellular modem. These devices plug into your laptop and provide a high-speed cellular broadband connection, often at speeds approaching home DSL, depending on the cellular coverage.
Unfortunately the cellular approach has a cost. It's best to think of this as signing up with a second ISP - your cellular provider - costing about as much or more than your wired connection at home. There are sometimes less expensive plans or even day passes with severe restrictions on the amount of data you're allowed to transfer before extra costs kick in.
Check the internet - it's not uncommon for cellular sales staff to not have (or be unable to share) details that might get you a less expensive solution. Your peers, on the other hand, are often very willing to share their solutions.
Satellite
Satellite may be the only answer for you, if you are out of the range of hotspots, Starbucks and Cellular phone towers. There are, however, a couple of issues that might affect you.
In the fine print of a provider's agreement, it may state that your bandwidth may be throttled if you use too much. In other words, if you are doing a lot of large downloads or other high-bandwidth operations, the satellite company may slow you down - often to slower than dial-up speeds. Simple reason: the bandwidth on a satellite is limited and providers don't want people hogging it.
The delay you can notice from a satellite can be significant. The signal travels up to the satellite, sometimes over 22,000 miles, comes back down and the response is repeated. You may not notice the delay, but your computer will. Certain internet protocols can slow to a crawl because they can't handle the transmission delay due to the satellite.
But, when all else fails, it's certainly better to have satellite than no internet at all.
Today, the ability to stay connected while traveling is much easier than in days past. You just have to pick the best option for you in your needs, situation and location.
Get more free tech help and advice from Leo Notenboom by visiting http://ask-leo.com With over 30 years of industry experience, including an 18 year career as a software engineer with Microsoft, Leo gives real answers to real questions from ordinary computer users at Ask Leo! Subscribe to Leo's weekly newsletter now and receive a free ebook: "Internet Safety - Keeping Your Computer Safe on the Internet", a collection of steps, tools and concepts you need to know to keep your computer and your information safe.
By Leo Notenboom

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