Field of Science


Keep Your Brain Healthy (a quiz)

Happy Friday! Have some sludge.

1. In honor of the Oscars this weekend, we'll start with a still from a very cool video. What is this?
a. a bioluminescent squid
b. fungus farmed in an ant colony
c. the inside of a mouse embryo
d. a model of new galaxies forming in space

(If you like videos that zoom through mysterious objects, also check out these fruit-and-vegetable MRIs.)

2. According to new research, climate change is having what effect on your allergies?
a. Allergy season has lengthened by two to four weeks in some parts of North America.
b. The ragweed population is declining due to mass die-offs of one of its major pollinators.
c. Allergy sufferers' symptoms have decreased by up to 12%, since heat represses histamine activity.
d. There's no such thing as climate change. We should keep burning fossil fuels, because carbon dioxide is good for plants.

3. Using video and chemical sampling of the ocean floor in the Gulf of Mexico, oceanographer Samantha Joye found:
a. almost no oil, hooray!
b. blankets of oil several inches thick
c. healthy populations of sea creatures
d. bacterial spit

4. Speaking of sludge, Indonesia could spend the next 20 to 90 years dealing with constant flow from its:
a. mud volcano
b. tar geyser
c. oil pipeline rupture
d. sewage river

5. Finally, good news (for some people). Apparently, being bilingual can:
a. reduce stress
b. make your brian bigger
c. delay the onset of Alzheimer's disease
d. prevent brain tumors

Answers are in the comments.

 Image: Ian Smyth, Monash University.

Woo Hoo, Witchy Woman

The latest piece by reporter John Tierney has been flying up the New York Times most-emailed list today. You may remember Tierney from his previous appearances on this site, where he argued that men are inherently better than women at math and science. Today's article, though, is about evolutionary psychology, a field that involves blessedly little in the way of numbers--perfect for my analytically impaired brain!

The article is about a new study by Florida State University graduate student Saul Miller and his advisor, John Maner. In the Journal of Experimental Social Psychology, Miller and Maner argue that women put out sexy signals while they're ovulating. While single men respond by seeing ovulating women as more attractive, men in committed relationships rate ovulating women as less attractive. The authors call this phenomenon "relationship maintenance." That is, men in relationships insist that the most fertile women aren't attractive, in order to preserve their relationships.

I should say woman, not women. The study involved 38 male college students and one (1) (ONE) female college student. But don't worry, the authors made sure to choose a woman who was "approximately average in attractiveness." (Hope she didn't read their paper.)

Over the course of three months, each man spent one 20-minute session with the woman, working on "several cooperative tasks" that apparently involved Legos. After his session, each man rated the woman's intelligence, outgoingness, flirtatiousness, and attractiveness on a scale from 1 to 5. He also indicated whether he considered himself to be in a "committed relationship."

To make sure the woman didn't botch the results by employing any agency in her own attractiveness, Miller had her go without makeup, keep her hair in a ponytail, forego scented products such as perfume or deodorant, and wear jeans and a t-shirt. She "underwent extensive training on how to remain expressively neutral"--in other words, how to not flirt. Thus prepared, the female student presumably had no way of influencing how men perceived her, and was rendered a sweaty, regularly-cycling robot. (I'm surprised they didn't add glasses.)

The men's ratings were plotted against the woman's menstrual cycle. Single men, Miller reports, rated the woman as marginally more attractive during ovulation, though this result was not statistically significant. But men in relationships rated the woman as significantly less attractive when she was ovulating, confirming the authors' hypothesis about "relationship maintenance." Attached men perceive a woman's fertility signals and, in an act of self-protection, tell themselves she's not so hot.

Tierney writes,
It's possible that some of the men in Florida were just trying to look virtuous by downgrading the woman's attractiveness, the way a husband will instantly dismiss any woman pointed out by his wife. (That Victoria's Secret model? Ugh! A skeleton with silicon.)
But paper co-author Jon Maner insists, "It seems the men were truly trying to ward off any temptation they felt toward the ovulating woman."

As unimaginative as his Victoria's Secret joke is, Tierney's lack of criticism toward this paper distresses me more. He fails to point out to his Times readers the dubiousness of a study that relies on one female subject--and that creates an entire 28-day curve out of 12 data points (only 12 of the 38 men were actually in relationships). He doesn't make note of the arbitrariness of "statistical significance" when all your results are on a subjective 5-point scale. Nor does he mention the paper's control: the authors had two other women watch videos of the female subject and rate her on various days, in order to provide "objective ratings of attractiveness."

And although he discusses other current research in evolutionary psychology--for example, studies saying that ovulating lap-dancers get higher tips and that fertile women dress better--Tierney doesn't question the central idea of the paper.

Other research, as Tierney mentions, has suggested that women are programmed to consider cheating, so that they can sneak a child with more desirable genes into their monogamous relationships. Being in a committed relationship is a plus, evolutionarily speaking, but more so for women than for men. The more surviving kids you create, the more evolutionarily successful you are by definition. So while it probably benefited the cavewomen to keep a provider nearby, it benefits males of most species to spread their offspring around as much as possible. The idea of male "relationship maintenance," while a nice story, goes against the rest of evolutionary biology.

But the idea of women as crafty temptresses whom men must actively resist was, apparently, too tempting for John Tierney. He must really hate ponytails.

Name That Cross Section!

Scroll down through this sequence of pictures. What do you see?

If you said "an artichoke as seen by an MRI machine," you're right! (And this guy would like to talk to you.) 

Andy Ellison is an MRI technician at the Boston University School of Medicine. He first put an orange through the machine one day to make sure it was working correctly. "A problem with the scanner would show itself with most fruits and veggies," he explained to Science. But it turned out that the inside of an orange was pretty cool in its own right. So Ellison started scanning all kids of produce and posting the videos online.

You should definitely go to Ellison's blog, Inside Insides, and watch a few of the videos. Following the scanner through its vegetable odysseys is a little bit like traveling through black hole, or maybe being digested by a squid.

In the meantime, see if you can identify these produce items. Bonus points if you spot any ligament tears.

Answers are in the comments. 

All images from Andy Ellison,

Like Sputnik, but Colder

Nearly four kilometers under the surface of the Antarctic ice is Lake Vostok, a giant freshwater lake that's the world's third-largest by volume. It's existed for 35 million years, and it's been sealed off from the air for the past 15 million of those. No human has peeked under that ice. The water could hold ancient forms of life that we've never seen before.

Knowing it's there, do do you leave a pristine time capsule alone? Or do you fire up your giant drill, grab a few thousand gallons of antifreeze, and hack your way in there? A team of Russian scientists, knowing their answer (and apparently never having seen this episode of The X-Files), has been trying their hardest to get through the ice. Last week they were within 30 meters of the ancient lake when they had to quit.

The Russians have been trying to crack the surface of Lake Vostok since the 1990s, with many delays. After finally coming up with a plan to tap into the lake that was deemed scientifically acceptable, they began their last push (they thought) in January. As the end of the Antarctic summer approached, the team ran their drill 24 hours a day. But on February 6, they had to stop and high-tail it off the continent before dropping temperatures stranded them there. If they stayed in Antarctica any longer, their airplane's hydraulic fluid might have frozen. They'll return in the next Antarctic summer to finish what they started.

What might they find in Lake Vostok? There could be nothing living there; the lake is under total darkness and high pressure from the ice above it. If nothing else, there could be interesting microscopic fossils on the bottom of the lake. But if there are living microorganisms in the water, they could tell us what life looked like tens of millions of years ago, or what previously unknown tricks life uses to adapt to extreme conditions.

There are some concerns, though, that the Russian team's plan is unsafe. The chemicals they're using to lubricate their drill and keep the surrounding ice from refreezing could contaminate the lake, for one. Getting into the lake and finding out that you killed the world's oldest organisms would sure be a blow to morale. The Russians say their plan prevents that: they'll stop drilling just short of the water's surface, then retract their drill, letting the higher pressure of the lake push fresh water up into the hole. The water will refreeze, and the team will extract it as an ice core, never having to dip their instruments into the unpolluted water.

At least one scientist has a different concern. Montana State University ecologist John Priscu, who will soon be part of an American team drilling into other Antarctic lakes, says the waters of Lake Vostok are full of gases. Once the Russians break through the surface, Priscu thinks lake water could come shooting back at them like celebratory champagne. "You'd geyser out the top, and you'd drain the lake into the atmosphere," he says.

Next winter (in northern-hemisphere seasons, that is), we'll find out whether Lake Vostok is a hotbed of new life forms or a huge geyser-involving catastrophe. It could also be kind of a letdown. But don't worry, the Antarctic excitement won't end there: In a couple more years, the Russians plan to send down a swimming robot.

Time to Move On

There's a new House of Representatives in town--and that means new discussions about climate change. Or, more likely, the same old discussions.

Yesterday, ScienceInsider published an interview with new Republican representative Mo Brooks, who will be chairing a House subcommittee on science research. One of Brooks's priorities is to hold public hearings on climate change.
Q: There have been lots of hearings over the years by Congress, including the science committee...
MB: But I haven't been on those committees.
If only someone had recorded what happened!

Brooks is a self-described skeptic when it comes to global warming. "I haven't seen anything that convinces me," he says. When asked if he thinks we should try to slow down our greenhouse gas emissions, he answered,
I'm very much the outdoorsman. But having said that, with respect to carbon dioxide emissions, there's some good associated with that, to the extent that we have higher levels of carbon dioxide. That means that plant life grows better, because it is an essential gas for all forms of plant life. Does that mean I want more of it? I don't know about the adverse effects of carbon dioxide on human beings. I'm not familiar with any, at present levels.
Oh my.

I've already addressed the standard arguments of climate change deniers, such as "Climate is cyclical," "There's no evidence for global warming," and "I hate the cold." The argument that burning fossil fuels helps plants was new to me. But it turns out to be a central argument of the Center for the Study of Carbon Dioxide and Global Change, a nonprofit partially funded by ExxonMobil.

That group was also the author of an open letter to Congress published on Tuesday. The letter's 68 signatories urge members of Congress to "make up your own minds about the matter."
Don't be intimidated by false claims of "scientific consensus" or "overwhelming proof." These are not scientific arguments and they are simply not true.
In addition to various conservative websites and climate skeptic blogs, the letter was published on the website for the Heartland Institute. This nonprofit has received hundreds of thousands in funding from (again) ExxonMobil. They've also gotten plenty of funding from Philip Morris, and one of their long-term projects has been to argue that second-hand smoke doesn't cause cancer.

All this was triggered by another open letter to Congress on February 1. This one was signed by 18 scientists and starts, "As you begin your deliberations in the new 112th Congress, we urge you to take a fresh look at climate change." The letter asks for hearings that address the "likely costs and benefits of action and inaction" on climate change, and not hearings that "attempt to intimidate scientists."
Congress needs to understand that scientists have concluded, based on a systematic review of all the evidence, that climate change caused by human activities raises serious risks to our national and economic security and our health both here and around the world. It's time for Congress to move on to the policy debate.
It remains to be seen whether Congress will, in fact, accept the science and move on. If we could block out the voices of oil companies and science deniers, maybe we could stop treading water and figure out what to do about this rising ocean.

Got a Weird Disease?

"How does this picture make you feel?" I asked Doug.

He thought for a moment. "Squishy?"

"Crunchy" would be more accurate, since this x-ray shows calcification inside someone's artery. (It gives me the willies, but that's not important.) The crunchiness comes from a rare genetic disease that was recently discovered by the National Institutes of Health's Undiagnosed Diseases Program.

The NIH launched their Undiagnosed Diseases Program in 2008 with the goal of understanding mysterious, House-worthy medical disorders. Since then, they've received more than 1200 referrals from physicians, and accepted closer to 200 of those cases for study. Out of all those cases, this is the first with a diagnosis.

NIH researchers studied the DNA of several family members who shared strange symptoms. They had calcification in the arteries of their lower bodies and hands and feet, along with, unsurprisingly, joint pain. Eventually, the researchers were able to pinpoint the problem: a mutation in the gene that codes for a protein called CD73. When this protein is functioning normally, it helps prevent calcium buildup. The scientists named their discovery "arterial calcification due to CD73 deficiency," or ACDC. (Cute.)

On the surface, it might seem inefficient for the government to put large amounts of money and manpower into a program that, in three years, has diagnosed one disease affecting nine people. But the reality is that scientists don't understand the function of most of our genes, and the genome's freak accidents can give us information about how things are supposed to work. The field of neuroscience was a big gray unknown before people like that guy with the spike through his head (or all of Oliver Sack's patients) came along and showed us, with their one-in-a-million problems, what the rest of our brains are doing right. The Undiagnosed Diseases Program, by focusing on minutiae, might unlock some of the secrets of the normally functioning human genome.

If you are at least six months old, are able to travel, and have a bizarre, undiagnosed disease of your own, you can apply to join the program. The NIH might fly you to Bethesda--but they make no promise to treat you.


Paging Doctor Dog

Marine is an 8-year-old female black lab. She is substantially more cuddly than a colonoscopy. But she's just about as good at detecting colon cancer.

The dog's Japanese owner and trainer, Yugi Satoh, has been teaching her to sniff out cancer cells since 2005. Marine is trained to sniff at bags containing breath samples from humans, then sit down in front of the sample that smells like cancer. No one knows exactly what chemical signature the dog is smelling, but Satoh says Marine has detected diseases as diverse as lung, breast, prostate, pancreatic and ovarian cancer.

In a new study, Marine sniffed human stool samples in addition to breath samples. She was first given samples from patients with colon cancer and told to find a match. Sniffing breath samples from 306 people, 48 of whom had colon cancer (as diagnosed by a colonoscopy), the dog correctly identified 91% of the cancer patients. With stool samples, she picked out 97% of the cancer patients. And she correctly ignored 99% of the samples from healthy patients.

It may seem incredible, but disease-sniffing dogs aren't new to science. A British charity called Cancer and Bio-detection Dogs trains dogs of various breeds to sniff out bladder cancer, and they've published the research to back up their claims. They also train dogs to live with diabetics; when a dog smells that its owner is having a hypoglycemic crisis, it runs to fetch the insulin kit. Marine, though, may have drawn the best disease detecting assignment--what do dogs love more than sniffing poop?

Author Hideto Sonoda says Marine was also able to pick out samples from patients with stomach, breast and prostate cancer when told to search for the colon cancer smell, though these data aren't included in the paper. This implies that various cancers share the same smell. To find out whether the cancerous smell comes from the presence of a new odor or the absence of a healthy odor, the researchers mixed together stool samples from healthy subjects and cancer patients. The dog still identified the mixed samples as cancerous, suggesting that cancer does have a signature scent.

It would be impractical to bring in dogs and their trainers for routine medical tests, the authors say. But they hope that further research will help them find the exact molecule that causes the cancer smell. Tests for this molecule could then detect cancer in its early stages.

This isn't Marine's first time in the news, by the way. In 2008, when she was already proving her prowess at sniffing out cancer cells, Yugi Satoh decided to have the dog cloned by a South Korean firm called RNL Bio. The firm had previously been hired by a California woman who paid them $150,000 to clone her beloved dead pit pull, Booger.

Four cloned puppies came from Marine's cells. RNL Bio named them Marine-R, Marine-N, Marine-L, and Marine-S (the S stands for...South Korea?) Two of the puppies were to be given to labs, and the other two would be sold.

All dogs are excellent sniffers, so it seems likely that a dog's training is more relevant to its disease-detecting abilities than whether it has the exact genome of another disease-sniffing dog. But wherever those puppies are now--hunting diseases or not--odds are, they're happily sniffing poop.

Clarification: A person having a hypoglycemic attack needs sugar, not insulin. The dog in the diabetes example would fetch its owner's insulin kit so the owner could check her blood sugar levels. (Thanks, Brenna!)

Killer Plant Turns Cute

The children's magazine I edit has a science news feature in every issue, with six or seven quirky stories. It's hard to say exactly how I choose these stories out of all the science news I read each month. But if I had to quantify the process, I'd say I give one point to any item about robots or dinosaurs, two points for cute animals, an extra half-point for anything miniature, and about eleven points for poop. So this story emerged as a clear winner.

In the appealing-sounding "peat swamp forest" of Borneo, a team led by ecologist Ulmar Grafe studied the carnivorous pitcher plant Nepenthes rafflesiana elongata. Compared to the typical variety of its species, the elongata variety is lousy at catching insects for food--seven times worse, in fact. So how does it survive? A clue came when the team discovered tiny bats roosting inside some of the pitchers.

N. rafflesiana elongata has extra-long pitchers that the tiny bats (a subspecies called Hardwicke's woolly bats, with a body just an inch and a half long) can comfortably fit inside. Grafe suspected that the plant and bat had evolved a mutualistic relationship: the bats dozed safely inside the pitchers, and the plants digested the poop their guests left behind. To test this, he glued tiny transmitters onto the bats' backs and tracked which plants they visited. Then he analyzed the nitrogen composition of the pitcher plant leaves.

As Grafe had guessed, the pitchers that housed bats (about a quarter of the elongata pitchers observed during the experiment) had significantly higher nitrogen levels than those that were bat free. The plant hasn't gone totally vegetarian, but supplementing its insect diet with bat droppings seems to have been a successful evolutionary strategy.

The pitchers grow with a tapered shape that bats can wedge their heads down into, so they don't have to cling to the slippery pitcher walls with their feet. The pitchers also have a reduced amount of fluid stored inside; after all, it's hard to convince guests to stay the night when they'll be sleeping with their heads next to a pool of digestive juices. The plant has apparently renovated itself to become a convenient bat hotel. The researchers even found a couple of mother bats roosting with their babies.

No one's ever found a relationship like this before, where a carnivorous plant and a mammal work together. It's almost a heartwarming story--if you can forget about the poop.