Category Archives: Science

Life in a bubble

Hundreds of insect species spend much of their time underwater, where food may be more plentiful. MIT mathematicians have now figured out exactly how those insects breathe underwater.

By virtue of their rough, water-repellent coat, when submerged these insects trap a thin layer of air on their bodies. These bubbles not only serve as a finite oxygen store, but also allow the insects to absorb oxygen from the surrounding water.

“Some insects have adapted to life underwater by using this bubble as an external lung,” said John Bush, associate professor of applied mathematics, a co-author of the recent study.

Thanks to those air bubbles, insects can stay below the surface indefinitely and dive as deep as about 30 meters, according to the study co-authored by Bush and Morris Flynn, former applied mathematics instructor. Some species, such as Neoplea striola, which are native to New England, hibernate underwater all winter long.

Autism and the MMR vaccine

Science Tuesday: Back into the hornets nest is a thoughtful follow-up post on the decision of a scientist to vaccinate his child.

Autism isn’t like tuberculosis, there’s not a bacteria that causes the disease. In fact,most researchers believe that “autism” is not a discrete disorder, rather “autism is a clinically defined pervasive developmental disorder with phenotypically diverse neuropsychiatric symptoms and characteristics. These manifest as a spectrum of social and communicative deficits, stereotypical patterns and disturbances of behaviour.”Â¹
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If a particular trait’s heritability is 100% then the trait is due entirely to genetic variation, if the heritability is 0% then the trait is due entirely to environmental variation. By some estimates, heritability of autism spectrum disorders exceeds 90%
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repeated studies have found that autism diagnoses continue to rise even after the removal of thimerosal from the vaccine.
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Finally, when thinking about the environmental influences on autism, it’s important to explore the role of the environment on genetics. Many of the types of genetic changes that have been identified as causative in autism are indicative of some sort of DNA damage – DNA damage that may result from exposure to an environmental toxin. Many scientists, and I count myself in their number, feel that the recent autism ‘epidemic’ is due primarily to improved screening and diagnosis. In other words, prior to the 1980’s, many people suffering from autism were diagnosed as “slow” or misdiagnosed with another type of mental retardation. Unfortunately, there is no way to quantify this hypothesis.

This is one of the examples of what is so good about blogs. Great content that probably would not be available but through a blog.

Huge Ant Nest

[Google broke the original link when they trashed Google Video in poor way, which has become their habit. There history now shows they create very unreliable web services that are an embarrassment to any engineer. Still YouTube is difficult to avoid, Vimeo while not suffering from being a Google product and therefore unreliable based on Google’s history, Vimeo offers only a small fraction of the content found on YouTube.]

Very cool webcast. The ant nest goes 8 meters into the earth. The nest is engineered with vents to promote the flow of air, bringing in fresh air and expelling carbon dioxide created by the large fungus gardens. The scientists filled the ant next with concrete to excavate it: 10 tons of concrete were needed.

Science Sortof Explains: Hiccups

photo of Red Hot Pepper by John Hunter

I love spicy food (Indian food is my favorite food). In my garden, this year, I am growing some spicy peppers (which honestly I don’t really like on their own – I have discovered). Still I eat them some and I get the hiccups almost every time. So I finally used Google to find out why. That lead to – MayoClinic on Hiccups:

A hiccup is an unintentional contraction of your diaphragm – the muscle that separates your chest from your abdomen and plays an important role in breathing. This contraction makes your vocal cords close very briefly, which produces the sound of a hiccup.

Although there’s often no clear cause for a bout of hiccups, some factors that can trigger acute or transient hiccups include: Eating spicy food. Spicy food may cause irritation to the nerves that control normal contractions of your diaphragm.

I must say the internet is great. Still that is hardly a great explanation for me. I almost never get the hickups eating spicy meals but every time I eat a hot pepper on its own I seem to (which happens very quickly and then ends pretty quickly – under 5 seconds). I guess somehow the other food in my mouth disrupts the potential nerve irritation so that it doesn’t cause a hiccup? It doesn’t seem like the raw pepper is hotter (higher Scoville Heat Unit) than the food, so I don’t think it is just a matter of more “heat” causing the hiccups.

Photo by John Hunter, Creative Commons Attribution-Share Alike (see requirements for use).

Dolphin Kick Gives Swimmers Edge

photo of Michael Phelps diving

Dolphin Kick Gives Swimmers Edge

Rajat Mittal, a professor of mechanical and aerospace engineering at the George Washington University, was studying dolphins for the U.S. Navy five years ago. “We were asked to understand how fish swim so efficiently,” Mittal says, “and it seemed like a natural extension to apply this to human swimming.”
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They decided to “essentially compare these swimmers to the dolphin, assuming that the dolphin is the ultimate swimmer,” Mittal says. “And the thing that we found is that Michael [Phelps] is able to use his body in a way that is very, very different from the other athletes, and also seems to be much closer to dolphins than we have seen for any other swimmer.”

The dolphin kick first hit Olympic swimming big-time 20 years ago, after Harvard backstroker David Berkoff figured out something fundamental. “It seemed pretty obvious to me that kicking underwater seemed to be a lot faster than swimming on the surface,” Berkoff says.

That’s because there’s turbulence and air on the surface of the water, and they create resistance. The “Berkoff Blastoff,” as it was called, was used at the start and after turns, with long stretches of that underwater undulating kick.

Follow the link for a video of Michael Phelps demonstrating the technique and more interesting details. Photo by A. Dawson shows Michael Phelps diving into the water at the 2008 U.S. Olympic Swimming Trials.

The PI lacks the experience with the proposed methodology…

A nice post from ScienceWoman: The PI lacks the experience with the proposed methodology…

Well, no kidding. I’m 3000 miles from my old stomping grounds. I’m trying to start an independent research program in a place where the geology/climate are not at all the same. I’m applying for $ for that are specific to Mystery State. Damn straight I’m going to need to learn a few new techniques. (And we’re not talking rocket science here.) But was there nothing in the proposal to suggest that I didn’t understand the techniques or wasn’t properly applying them. Just a lack of a publication record that explicitly used those techniques or occurred in this part of the country.

I suspect that this is a criticism that I’m going to see a few more times before tenure. And I suspect that it’s a criticism that’s not uniquely being leveled at me.
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In this case, this criticism isn’t the reason the proposal wasn’t funded. But it’s the one reviewer critique that I can’t surmount on the resubmission. It’s like that itch I can’t scratch. So I guess the resubmitted proposal is just going to have to be so kick-ass in all other respects that there’s no way they can deny me these funds. Better get to work.

How Humans Got So Smart

Cooking and Cognition: How Humans Got So Smart

For a long time, we were pretty dumb. Humans did little but make “the same very boring stone tools for almost 2 million years,” he said. Then, only about 150,000 years ago, a different type of spurt happened — our big brains suddenly got smart. We started innovating. We tried different materials, such as bone, and invented many new tools, including needles for beadwork. Responding to, presumably, our first abstract thoughts, we started creating art and maybe even religion.

To understand what caused the cognitive spurt, Khaitovich and colleagues examined chemical brain processes known to have changed in the past 200,000 years. Comparing apes and humans, they found the most robust differences were for processes involved in energy metabolism.

The finding suggests that increased access to calories spurred our cognitive advances, said Khaitovich, carefully adding that definitive claims of causation are premature.

Nice example of scientific discovery in action. The direct link from cooking to brain development is far from proven but it is interesting. I also like “the same very boring stone tools for almost 2 million years” – maybe that is because I am too cynical (but while evolution is amazing – sometimes it is amazing how slow progress is).

The Most Trusted Sources in Science

PBS: The Most Trusted Source in Science?

When Americans were asked in 2005 about their views on the credibility of information sources about biotechnology, a clear hierarchy of trust emerged starting at the top with scientific journals (almost 60% of respondents said they trusted journals as credible information ), followed by university scientists who are funded by government (50%), public television (50%), government scientists (40%), the WHO (40%), university scientists funded by industry (35%), biotechnology company scientists (30%), religious leaders (20%), TV networks (18%), biotechnology executives (15%), print media (15%), and political leaders (10%)

The data is from a survey by NSF in 2005. I predict PBS’ influence will grow as they provide valuable, open access, content online (the way the public will get most of their news).

Lighting in Slow Motion

Video deleted

The videos provides a super slow motion lighting strike. A separate lighting related item, from NASA: Gigantic Jets:

They are extremely rare but tremendously powerful. Gigantic jets are a newly discovered type of lightning discharge between some thunderstorms and the Earth’s ionosphere high above them. Pictured above is one such jet caught by accident by a meteor camera in Oklahoma, USA. The gigantic jet, at the lower left, traversed perhaps 70 kilometers in just under one second.

Invisibility Cloak Closer

Invisibility shields one step closer with new metamaterials that bend light backwards

Applications for a metamaterial entail altering how light normally behaves. In the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock. For optical microscopes to discern individual, living viruses or DNA molecules, the resolution of the microscope must be smaller than the wavelength of light.

The common thread in such metamaterials is negative refraction. In contrast, all materials found in nature have a positive refractive index, a measure of how much electromagnetic waves are bent when moving from one medium to another.

In a classic illustration of how refraction works, the submerged part of a pole inserted into water will appear as if it is bent up towards the water’s surface. If water exhibited negative refraction, the submerged portion of the pole would instead appear to jut out from the water’s surface.
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For a metamaterial to achieve negative refraction, its structural array must be smaller than the electromagnetic wavelength being used. Not surprisingly, there has been more success in manipulating wavelengths in the longer microwave band, which can measure 1 millimeter up to 30 centimeters long.