Archive for category Science

High Bad, Low Good

Hormesis. Sounds kind of odd, but it’s the idea that high doses of a compound are a poison, low doses are a tonic. Dr. Edward Calabrese advances the theory of Hormesis based on thousands of studies performed on all kinds of organisms. The proposed mechanism is that the low doses stimulates the body and the response is beneficial – for instance, a low dose of radiation causes a small amount of DNA damage which stimulates the body to repair it – if the dose is low enough, the repair exceeds the damage do to the radiation. Too high, and you die. It’s hard to build a therapy around, but it does mean we might not have to sweat the small stuff – for instance, there is a point past which cleaning up certain pollutants is actually counter productive, let alone pointless. And the EPA’s linear dose models would need to be changed. Still, it’s not widely accepted.

This passage caught my eye in the article:

In one session of the conference, veterinarian Dennis Jones, of the Agency for Toxic Substances and Disease Registry in Atlanta, presented recent findings on low-dose mercury exposure. Jones analyzed data from a study at the Centers for Disease Control that tracked more than 100,000 infants. The infants were given thimerosal, an organic compound of mercury used as a preservative in vaccines. The researchers worried that giving the infants too many vaccines might harm them. But Jones found that limited exposure to mercury actually lessened the children’s chances of developing neurological tics, delayed speech, and other pathologies. Jones’s analysis is preliminary, so he declined to give concrete numbers. But he called the study “exquisite” and said that it “really amazed” him. Calabrese was not amazed. “In our most recent database search,” he said softly into the microphone, “mercury is perhaps the most studied element showing a hormetic effect.” 

So while there’s no scientific evidence so far that mercury in vaccines cause autism, if hormesis is accurate, then there might actually be a benefit to mercury in vaccines. I can see why it’s hard to accept.

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The Tomato: Good Internally and Externally

OK, we already knew that lycopenes in tomatoes are good for your prostate and your cardiovascular system, but now another compound from the tomato makes a great insect repellent too. It’s as good as DEET but lasts longer.

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All You Need Is Bacteria

Apparently we do need germs. Without bacteria in the gut, your intestines won’t develop properly. A researcher at our own Washington University has discovered that without bacteria colonizing an infant’s gut after birth, blood vessels don’t properly develop and proliferate in the intestines. Maybe you really do need to eat a pound of dirt to grow up right, as my father-in-law says.

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Dogs Dogs Dogs

I’m a dog person. I like them, and they like me. I have never been able to make any of them understand the concept of pointing though, not one. They invariably stare at my hand – they know it must be important, but they can’t figure out how. Even my current dog, a Welsh Corgi, which according to the sign at Pass Pets is “highly intelligent” (another sign claimed a different breed was “very intelligent”, but we didn’t have time to ask the attendent whether highly beat very), can’t figure it out. This fine article in Science News claims that not only can dogs do this, but they have an innate, evolved in ability to do so. In fact, according to the research in the article, dogs are better than chimpanzees in figuring out what people’s gestures mean. The test was to put food in one sealed bowl and let them find it. The researchers would then look at or point at the correct bowl and let the animal use this gesture as a way to find it. This makes me feel better, because I talk to my dogs. They don’t let on they understand my pointing; maybe there just not letting on they understand my talking either. I don’t just praise mind you, but on walks we have whole discussions (pretty much one sided, I have to admit). I ask them what they’re smelling, what they’re hearing, and a perennial favorite, are you ever going to take a dump on this walk so we can go home? 

While I can’t get dogs to understand pointing, they’ve always understood the steps needed to take a walk. Now when it gets dark outside, my dog gets excited, and likes to be close – he doesn’t want you slipping out without him noticing. Certain sounds bring the dog running any time — the sound of the closet door where his leash is kept and the sound of the front door being unlocked. When you put on a coat, he does a little dance of joy. I know just how he feels – no seriously, I do. Freshman year in college, my dorm room overlooked a bike shelter. I was sweet on a particular girl, and in no time at all I could recognize the sound of her bike security chain from all the others. I’d hear the sound of the chain, I’d go look out the window. After I let slip my conditioning to my buddy Carl Drews, good scientist that he is, one afternoon he shook a chain at random and then waited, repeated this procedure a few times, and then shook her chain. I looked out the window, and instead of seeing her, I saw Carl grinning up at me – giving new meaning to the phrase pulling my chain.

The latest research indicates that dogs come from East Asia. When the first Americans came over the land bridge from Asia, they brought their dogs with them, just like the second Americans when they came over from Europe. And three dog night is the correct expression – it seems that 95% of dogs are descended from three lineages. They don’t mention Carolina dogs; it would be interesting to see how they fit in. Since the DNA was mainly collected at dog shows, I doubt they collected any.

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Worm Attacks: Invading earthworms threaten rare U.S. fern

That’s the title of an article in Science News. Apparently our homeland (yech, what an un-American word) is under attack by more than al-Qaida. I had no idea until I read the article, but America north of line between Massachusetts to Iowa has no native earthworms (no word on what happens west of there). When I read that, it reminded me of when I went off to school in California and discovered they had no lightning bugs. How can you not have worms? How can you not have lightning bugs? Anyway, some rare fern that requires a lot of leaf litter is being threatened by a particular European earthworm that does an otherwise admirable job of recycling leaf litter. I guess as an exotic European colonist myself, I can’t complain too loudly about the worms. What did the early bird eat in Minnesota before the European worms showed up?

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The Science of Humor

How do neuroscientists study the brain’s response to humor in a natural setting? They have monitor the brain activity of subjects while watching Seinfeld. They use the laugh track to synch up the jokes with the brain’s response. Then to evaluate the effect of the laugh track, they have the subjects watch the Simpsons since it has no laugh track. The laugh track had no effect on the brain’s response (they didn’t address whether it makes a show funnier).

They discovered that humor is a two step process in the brain – first regions associated with resolving ambiguities (the posterior temporal cortex and inferior frontal cortex) are active, and then within seconds regions associated with emotion and memory are active (insula and amygdala). In other words, scientists have conclusively proven that you have to get the joke before you think it’s funny. Unless, of course, it contains the word duck.

Titan Has Clouds

Astronomers in Hawaii have spotted clouds on Titan, Saturn’s largest moon. Cool.

Smallpox Vaccine: Good News and Bad News

The St. Louis Post-Dispatch reports good news and bad news about the results of a pilot study on the Smallpox vaccine carried out right here at St. Louis University. The good news is that it would appear diluted vaccine does confer an immune response in people who were vaccinated previously (the general public hasn’t been vaccinated since 1972 in the US). Since there are only 15 million vaccine doses and more than 280 million Americans, that’s good news. Some scientists worried that the old vaccination would not confer enough of a response to require an even larger dose of the vaccine, let alone not allow a smaller dose to work. The bad news is that the old vaccination doesn’t appear to provide an immune response after more than 30 years – 10 years is apparently the accepted length of time, so for all of us who were once routinely inoculated and have that weird looking scar to prove it, we have no increased immunity to smallpox. A larger study is now being started to determine just how diluted the vaccine should be. If you’re worried and were once vaccinated, then call the Center for Vaccine Development at 314-977-6333 and see if you can sign up – although I warn you that people do have adverse responses to the vaccine (beyond the two weeks of a pus filled sore at the vaccination site).

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