Friday, March 23, 2007
Tuesday, March 20, 2007
Chinese scientists publishing in this week's Proceedings of the National Academy of Sciences have sequenced and characterized the genome and partial proteome of Geobacillus thermodenitrificans NG80-2, a heat-tolerant bacterium isolated from a deep oil reservoir in
Bo-ring. Why should we care? Well, the bacteria can subsist entirely on crude oil, able to break down oil's long-chain alkanes into smaller molecules that they then use as food. This isn't news—scientists previously knew that this strain of bacteria could break down long-chain alkanes—but what these scientists discovered by studying their genome is that they should be able to survive well in, say, oil-contaminated environments, which are frequently warm, starved of oxygen, and contain high levels of toxic hydrocarbons, antimicrobial agents and heavy metals. G. thermodenitrificans appear to have excellent systems to deal with these potential problems, including good nutrient uptake and detoxification systems, tolerance to heat, and the ability to utilize both aerobic and anerobic respiration. They should be more than happy to veg out in oil reservoirs and environments contaminated by oil spills, breaking down and digesting the nasty stuff.
The scientists also isolated and characterized the enzyme that breaks down long-chain alkanes, naming it ladA. This introduces the possibility of being able to manipulate or utilize the single protein—rather than the whole bacterium— for oil clean-up. And since these bacteria are heat-stable, they could also someday be the source of other useful heat-stable enzymes. Lord knows Taq changed our lives.
Tuesday, March 13, 2007
Lynn Margulis makes jaws drop
Just what we need: more arsenic
Modeling arsenic intake for the U.S. population based on this survey shows that for certain groups (namely Hispanics, Asians, sufferers of Celiac disease, and infants) dietary exposure to inorganic As [which is considered the most toxic form of arsenic] from elevated levels in rice potentially exceeds the maximum intake of As from drinking water (based on consumption of 1 L of 0.01 mg L-1 In. As) and Californian state exposure limit.In other words, people who regularly eat rice and also happen to drink water occasionally could be ingesting a lot more arsenic than the EPA says is acceptable— and even the EPA's limits are a bit lax, as I've written before:
The bottom line is, the last thing we need is to be ingesting more arsenic. Who knows where else the carcinogen is seeping into our diets. Water, chicken, rice—what's next?
Any increase in Americans’ levels of arsenic exposure is of great concern: The Environmental Protection Agency, which regulates drinking water, considers arsenic a class A carcinogen, meaning that data have definitively shown it to cause cancer. Other health effects from chronic low-level exposure include partial paralysis, blindness and diabetes. Although the EPA tightened its regulations for arsenic levels in drinking water this past January , lowering it from a maximum of 50 parts per billion (ppb) to 10 ppb, this new level still exceeds the agency’s recommendations for exposure to a carcinogen by a factor of 50.
The EPA typically recommends that the amount of a carcinogen in drinking water should not cause more than one person in 100,000 to develop cancer as a result of drinking that water daily. But Americans who are regularly drinking water containing 10 ppb of arsenic are at a 50-fold higher cancer risk than this: in other words, one out of every 2,000 of those Americans is likely to develop cancer because of the arsenic in their tap water. And the EPA estimates that 12 million Americans are currently drinking water containing more than 10 ppb of arsenic—making their cancer risk even higher.
The EPA isn’t meeting its own safety standard for arsenic because the recommended amounts “are set at a level which water systems cannot meet,” according to agency press officer Dale Kemery. After preparing a cost / benefit analysis, the EPA set its arsenic limits at a level that maximized risk reduction while minimizing cost to the consumer, he says.
Monday, March 12, 2007
Personality and musical taste
Here are the findings, in a nutshell. I found them more than a little amusing:
In short, people who listen to jazz are smart, liberal, adventurous, and poor; people who listen to heavy metal are smart, liberal, adventurous, athletic, and prone to social dominance; people who listen to Madonna or the "Dancing With Wolves" soundtrack are agreeable, conscientious, conservative, rich, happy, dumb, emotionally unstable, and hot; and people who listen to hip hop are extraverted, agreeable, liberal, athletic, and hot. Well, those are the tendencies at least (I've known some smart Madonna fans, though I have to say that they were pretty emotionally unstable).You can read his entire post here.
I notice they didn't comment on country music fans.... Perhaps better left unsaid?
As someone with not one, not two, but THREE jars of peanut butter in her cupboard, I am feeling a bit queasy (heh) about the recent news from the FDA.
The agency first announced on Valentine's Day that consumers who had bought Peter Pan or Great Value brand peanut butters since May 2006 should discard them because they could be contaminated with salmonella. As if that weren't bad enough, the FDA updated its warning two days ago. Now, anyone who's bought jars of this peanut butter since October 2004 could be at risk.
Who knew Peter Pan had it in him? Jerk.
Sunday, March 11, 2007
Nerves use sound?
There doesn't seem to be a study associated with this story, nor were the researchers interviewed, so who knows. Still kinda interesting though...