Showing posts from October, 2007

Virus more powerful than a car

Relative to its size, a molecular motor used by viruses is twice as powerful as an automobile engine. That's why even very large viruses can self-assemble so rapidly. Researchers used laser tweezers to measure forces generated by the nanoscale motor that packs DNA into a virus during the assembly of an infectious virus particle. This power allows the virus to reel in its long genome with remarkable speed. “The genome is about 1,000 times longer than the diameter of the virus,” explained Douglas Smith, an assistant professor of physics at UCSD and co-author of the study . “It is the equivalent of reeling in and packing 100 yards of fishing line into a coffee cup, but the virus is able to package its DNA in under five minutes.” The researchers say that their work could ultimately lead to better ways of designing antiviral medications. Drugs that target the DNA-packaging process could block the infection cycle by preventing viral assembly. Such drugs could also interfere with the abi

Where's the bathroom?

"¿Donde esta el baño?" "Ou sont les toilettes?" "Ein ahmer-hathe min fathe-lick?" Some answers to that question can panic a traveler. Perhaps no answer is as disturbing as, "Bathroom? What bathroom?", particularly when delivered with a sweeping gesture toward an endless, featureless landscape. The toilet habits of Americans are based, thanks to largely urban and suburban upbringing, on high expectations. Indeed, discussions about the relative advantages of one-ply or two, quilted or not, folded or bunched, can go on at length, in certain odd social circumstances, without second thought to the availability of toilet tissue, nevermind an appropriate place to use it . In privyless generations an outhouse would have been a step up. Pioneers in covered wagons, no doubt, dreamed of a two-holer for the relative comfort afforded as protection from Nature's vagaries. Add pages torn from a Sears catalog and the next thing to luxury was at hand when com

An appendix is a good thing

No not a book appendix, silly. The one in your belly. It's been dissed all these years—everyone says it's superfluous, has no function, tits on a boar, that kinda thing—but it's actually useful, it turns out. And not just the way Alfred Sherwood Romer and Thomas S. Parsons suggest in The Vertebrate Body (1986), p. 389: "Its major importance would appear to be financial support of the surgical profession.” Docs at Duke University Medical School published a report this week that say it produces and protects good germs for your gut. But it can kill ya. In fact, over 300,000 were hospitalized in the U.S. with appendicitis in 2005, and about 300 to 400 Americans die of appendicitis each year. Remember , there are more bacteria cells than human cells in your body—10 to 1, actually. (Ewww.) But what happens if the bacteria in your intestines die or are, to use a delicate word, purged? Diseases such as cholera or amoebic dysentery clear your guts of useful bacteria (oh yeah,