30 Oct 2009
How Terahertz Waves Tear Apart DNA

We never seem to learn, do we? We are monkeying about with forces that we just barely understand, and are bound to pay a price. I wonder who'll will be the next group of radium girls?

Great things are expected of terahertz waves, the radiation in the electromagnetic spectrum between microwaves and the infrared. Terahertz waves pass through non-conducting materials such as clothes, paper, wood and brick and so cameras sensitive to them can peer inside envelopes, into living rooms and 'frisk' people at distance. That's not to mention the great potential they have in medical imaging. Because terahertz photons are not energetic enough to break chemical bonds or ionize electrons, it's easy to dismiss fears over their health effects. And yet the evidence is mixed: some studies have reported significant genetic damage while others, although similar, have reported none. Now a team led by Los Alamos National Labs thinks it knows why. They say that although the forces that terahertz waves exert on double-stranded DNA are tiny, in certain circumstances resonant effects can unzip the DNA strands, tearing them apart. This creates bubbles in the strands that can significantly interfere with processes such as gene expression and DNA replication. With terahertz scanners already appearing in airports and hospitals, the question that now urgently needs answering is what level of exposure is safe.

(link) [Slashdot]

19:42 /Technology | 0 comments | permanent link

How dangerous are coyotes?

In the humble opinion of this heathen farm boy, the article is both right and wrong. Right in the sense that coyotes are naturally human avoiders, and we (humans) are certainly in more danger from pit bulls and other feral dog breeds. My sheep are in danger of both.

It's wrong in that feral domestic dogs, which are dumped in the country with amazing frequency, can and do breed with coyotes. "Coy-dogs", they're called around here, and they can and have attacked people and livestock. That's the real danger. Packs of these half-breed critters have cut and brought down grown bulls as well as kids on bicycles.

The problem would be solved if only city folks would stop driving out to the country and dumping litters of unwanted puppies. But that, of course, would mean wholesale reform of our animal welfare system.

I'm not holding my breath, but I am buying more ammo.

Coyote populations are growing, in the wild as well as in populated areas where they hunt for pets and garbage. But attacks are rare and, statistically speaking, coyotes are far less of a threat than pit bulls.

(link) [Christian Science Monitor]

19:36 /Home | 0 comments | permanent link