Smithsonian.com

When you think about it, American money is kind of boring. It’s fairly drab in color, and rarely have people other than U.S. presidents been found on our dollars or coins. Other countries put more interesting people, like scientists, on their money, often using a rainbow of colors. Even more daring, though, is to not put any people at all on a country’s banknote. The image above is the 2000 Lei note (now obsolete) from Romania. It commemorates an August 1999 solar eclipse that was visible from Romania to India.

What event or person would you like to honor on a banknote or coin? Tell us in the comments below.

And check out the entire collection of Pictures of the Week on our Facebook fan page.

Shoes or no shoes? That is the question these days. Photo courtesy of flickr user joshuahoffmanphoto.

My husband’s favorite story to tell about his first marathon is that a woman in stocking feet beat him.

“And it was in Vermont…in October…on gravel roads,” he always adds, still amazed at the freakish phenom.

That was in 2006, and now just over three years later, barefoot running, though clearly not the norm, is becoming more common. (Or nearly-barefoot running is, at least.) Just this past weekend, while running on the National Mall, I saw a runner ahead of me wearing Vibram FiveFingers, the lightweight, glove-like shoes now being sold at sporting goods stores.

Runner’s World, Wired, Popular Science, Popular Mechanics and the New York Times have all joined in on the “shoes or no shoes” debate. The barefoot contingent argues that running shoes that promise to provide the needed stability or correct pronation issues negatively affect a runner’s form and may also lead to injuries. “We’re being fleeced,” writer and barefoot enthusiast Christopher McDougall told U.S. News & World Report.

In his bestselling book Born to Run, McDougall writes about the Tarahumara Indians of Mexico’s Copper Canyon who run extraordinary distances (we’re talking up to hundreds of miles) in simple sandals without experiencing the injuries that plague most runners. He uses the Tarahumara to prove that, as humans, we are built for this type of running. Running barefoot, people have a more upright body position and shorter strides, landing first on the middle or ball of the foot, rather than the heel, as is often the case when wearing cushy shoes.

Having run track in college and a marathon since then, I’ve had my share of muscle pulls and stress fractures. So my ears perk with this news of a possible remedy. But it takes more than recommendations from “Barefoot Larry” and “Last Place Jason” on a Runner’s World forum to convince me to lose my shoes. What’s tempted me as of late is the release of two new studies—in the December 2009 issue of PM&R: The journal of injury, function and rehabilitation and another in this week’s edition of Nature—that come down hard on shoes. One found a 36 to 54 percent increase in knee and hip torques in runners wearing shoes versus those who did not.

Experts advise barefoot beginners to ease into it and run barefoot only ten percent of the time. This way, they can toughen up their feet and ankles.

Living in Washington, D.C., I fear the shards of glass on the city’s sidewalks—nothing a pair of Vibrams can’t protect me from, I guess. Then, there are the stares from baffled onlookers. But maybe I’ll get up the nerve to give barefoot running a try…

A spider shown with a maturing larva attached to his abdomen. (Courtesy of William Eberhard)

It hasn’t taken much research (aside, I guess, from trial-and-error) to know humans under the influence of anything, from martinis to marijuana, tend to function less efficiently .

But that doesn’t seem true for certain spiders, according to research done by William Eberhard, an entomologist at the Smithsonian Tropical Research Institute, and his team in Costa Rica. They found that orb-weaving Allocyclosa bifurca spiders “under the influence” of chemicals from parasitic wasps spun stronger webs.

The relationship begins when the female wasp traps the spider on its own web (how humiliating) and lays an egg on the spider’s abdomen. The egg grows into a larva that makes small holes in the spider’s skin so it can drink vital juices from the spider to survive.

After about a week, the larva matures—and having no apparent need for the spider any longer, kills it and drinks the rest of the spider’s internal fluids until only a husk of the former spider remains. (Sorry for those of you who are squeamish). The larva builds itself into a cocoon on the spider’s web, and emerges as a mature wasp a few weeks later.

A spider's typical resting web, which it spins without the influence of the parasite. (Courtesy of William Eberhard)

How parasites affect their hosts’ nervous system is a poorly understood area of research. Eberhard allowed wasps to lay the eggs on the spiders and watched as the larvae grew. He noted how the behavior of the spiders, and the shape of the webs, changed as the larvae matured, but removed the larvae right before they killed the spiders.

The larva manipulates the resting web of the spider so it better protects its own cocoon (which can be seen in the center of the web) as it matures into a wasp. (Courtesy of William Eberhard)

Eberhard found as the larvae matured, the chemicals began to “affect the spiders at higher levels of behavioral decisions that determined the overall design of the webs,” so that the web protects the parasite, and not the spider, as it matures. So, when the larvae are young, they simply trigger the spiders to begin building a resting web, as if the spiders were building the webs for themselves. When the larvae are more mature, they induce the spider to manipulate the web’s actual design so it better protects a cocoon instead of the spiders themselves.

By removing the larvae before they killed the spiders, Eberhard also allowed the spiders to “sober up” and resume their normal behavior (which they did, oddly enough, in the reverse of the order in which the changes occurred).

Experiments like these are helpful for studying future animal behavior because the manipulations parasites make in their hosts’ behavior have “been honed by natural selection over long periods of time,” Eberhard told the blog Smithsonian Science, “Understanding how these mechanisms work promises new, exciting and potentially powerful access into determining how animal behavior is controlled.”

So if you see a spider that looks a little off (or who spins a web that looks like the one to the left) you should feel bad for the poor guy—the larva may have already taken over.

Will these girls learn to fear math from their teacher? (courtesy of flickr user woodleywonderworks)

We know that girls can do math, and be very good at it. But a new study published this week in PNAS shows that some girls in elementary school aren’t learning just how to add one plus one—they are learning that girls should be scared of those numbers. Just like their teachers.

University of Chicago researchers assessed the math anxiety of 17 first- and second-grade teachers in a large Midwestern urban school district. (When someone has math anxiety, they can master mathematical concepts but tend to avoid the subject and perform more poorly than their abilities allow.) They also assessed the math performance levels of the teachers’ students at the beginning and end of the school year as well as whether or not the students believed the stereotype that girls do better in reading and boys do better in math.

The researchers discovered that in classes with teachers that have math anxiety, math achievement at the end of the school year was worse for girls but not for boys. Girl with such teachers were also more likely to endorse the stereotype that boys are better in math and girls are better in reading. What’s going on? The teachers in question were not worse at teaching math, the scientists say, but they were somehow passing on the idea to the young girls in their classrooms that math is scary. The researchers write:

We speculate that having a highly math-anxious female teacher pushes girls to conform to the stereotype that they are not as good as boys at math, which, in turn, affects girls’ math achievement. If so, it follows that girls who confirm traditional gender ability beliefs at the end of the school year should have lower math achievement than girls who do not and than boys more generally. This is exactly what we found. …

In addition, children do not blindly imitate adults of the same gender. Instead, they model behaviors they believe to be gender-typical and appropriate. Thus, it may be that first- and second-grade girls are more likely to be influenced by their teachers’ anxieties than their male classmates, because most early elementary school teachers are female and the high levels of math anxiety in this teacher population confirm a societal stereotype about girls’ math ability.

The problem really starts in college, where the elementary education major requires little math. This appears to be attracting math-phobes, and, not shockingly, there is a higher incidence of math anxiety among elementary education majors than individuals in any other college major. So our college education system is churning out a disturbing number of role models for little girls who find math harder and scarier than Barbie ever did. And they’re teaching their charges—if unintentionally—to follow their lead.

What should be done? My impulse is to say that we should raise the math requirements for elementary education majors beyond basic algebra and geometry and weed out some of the math-phobes. And if you’re thinking of becoming an elementary school teacher and are scared of math, perhaps you should find another profession.

I’ve been reading all the news about the Large Hadron Collider for months, but apparently I missed the most important bit about the LHC: the project has its very own rapper, ATLAS e-News science writer Katherine McAlpine, a.k.a. “AlpineKat.” Her Large Hadron Rap went viral, with more than 5.5 million views as I write this. Her latest creation, above, is the Black Hole Rap and addresses concerns that the HLC will create a black hole that will consume the Earth and everything—and everyone—on it.

Now I just hope that someone here at Smithsonian doesn’t get the idea that all science writers—such as me—are as talented in this area as AlpineKat.