When scientists talk up learning about transportation networks from nature, it’s often ants that get the praise for being so much more organized and efficient than we humans with our silly gridlock. But a team of Japanese researchers found, for a new study in Science, that you don’t even need a brain to be to a traffic genius. Single-celled slime molds, they found, can build networks as complex as the Tokyo subway system.

The yellow slime mold Physarum polycephalum grows as a single cell that is big enough to be seen with the naked eye. When it encounters numerous food sources separated in space, the slime mold cell surrounds the food and creates tunnels to distribute the nutrients [Science News]. To test how efficient the mold could be, Toshiyuki Nakagaki’s team duplicated the layout of the area around Tokyo: They placed the slime mold in the position of the city, and dispersed bits of oat around the “map” in the locations of 36 surrounding towns.

The mold explored slowly at first, but like any good transportation engineer it began to figure out traffic patterns. To continue growing and exploring, the slime mold transforms its Byzantine pattern of thin tendrils into a simpler, more-efficient network of tubes: Those carrying a high volume of nutrients gradually expand, while those that are little used slowly contract and eventually disappear [ScienceNOW Daily News]. When the mold got its system settled, researchers say, it looked rather similar to the actual Tokyo subway system, as you can see in the illustration.

The scientists didn’t just marvel at the slime mold’s mapped-out network; they also tried to capture its technique in math, Wolfgang Marwan added in an accompanying piece in Science. Marwan called the mathematical model “beautifully useful.” He added that: “It quantitatively mimics phenomena that can be neither captured nor quantified by verbal description alone” [Scientific American]. But will slime mold subways start to show us how we ought to be building our transport systems or other networks? Perhaps not so fast, says Portland State University’s Melanie Mitchell. “This paper uses only one relatively simple example,” she cautions. “It’s not obvious that similar experiments would work as well for matching other transport networks” [ScienceNOW Daily News].

Related Content:
Discoblog: Ant Intelligence Could Help Us Steer Clear of Traffic Jams
DISCOVER: Slime Molds Show Surprising Degree of Intelligence
DISCOVER: The Truth About Traffic

Image: Science/AAAS

This is the second in a series of guest posts by Joel Barkan, a previous contributor to “The Intersection” and a graduate student at the Scripps Institution of Oceanography. The renowned Scripps marine biologist Jeremy Jackson is teaching his famed “Marine Science, Economics, and Policy” course for what may be the last time this year (along with Jennifer Jacquet), and Joel will be reporting each week on the contents of the course.

Here in Southern California, we’re enduring an extended period of heavy rains and high winds, or as Floridians would call it, “July.” People from harsher climates may laugh at our predicament, but the truth is that San Diego and its residents are ill-equipped to deal with rain. Streets flood almost immediately because drainage is almost non-existent. Traffic slows to the kind of crawl I experienced during white-out blizzards while growing up in Maine.

Most San Diegans know not to swim in the ocean during and after a storm. The rain washes an assortment of chemicals, fertilizers, oil, and garbage straight down the hills and into the sea. How would you feel knowing the fish you ate for dinner came from a farm that similarly inundated the surrounding waters with bacteria? The discharge of waste is just one of many controversial issues concerning aquaculture, our most recent class topic here at Scripps.

Globally, aquaculture is the fastest-growing food production system, increasing by 8.8% per year since 1985, according to a 2007 report by the FAO. Aquaculture already accounts for around one-third of global fish production and may soon rival wild-caught fisheries as our primary source for fish. A shift to reliance on farmed fish could also lessen the burden on over-exploited wild stocks. It’s difficult to talk about aquaculture without mentioning the growing human population: simply put, we’re going to need more protein to feed an estimated 9.2 billion people by 2050. Proponents of aquaculture call it a possible solution to our potential food crisis.

Unfortunately, aquaculture is not the silver bullet that will magically save us from overfishing and global food shortages. Unless the farms are a closed system, effluent from fish pens will pollute the surrounding waters. Escapees can transmit diseases to wild stocks—they become parasite-bearing fish on the lamb, terrorizing the innocent locals. Plus, we need to catch millions of tons of wild fish, like the Peruvian anchoveta, to grind into fish meal to feed the farmed fish. It’s like hunting seagulls off the coast of Africa and using the gull meat to feed chickens on a farm in Arkansas. Despite these problems, we’re going to have to find ways to lessen the environmental impact of aquaculture as the industry continues to grow.

It was pointed out in class that a variety of U.S. government agencies regulate aquaculture, depending on where you are and why you’re doing it. A good start to better management of aquaculture in our country would be to streamline the regulatory power to a single agency. Then we can shift our focus to the rest of the world: to China, to India, to Chile, and every other country hoping to feed its people with farmed fish.

In the aftermath of Haiti’s devastating earthquake, nervous citizens can be forgiven for wondering where the next Big One will hit. Major quakes strike with alarming regularity: Earthquakes of magnitude 7 or greater occur approximately 18 times a year worldwide. They usually originate near faults where tectonic plates —tremendous fragments of the earth’s crust—collide or push above or below each other.

Geologists suspect that Haiti’s destructive quake resulted from 250 years of seismic stress that has been building up between the North American and Caribbean tectonic plates. In fact, a group of U.S. geologists presented a study in the Dominican Republic (which shares the island of Hispaniola with Haiti) in 2008 saying that the region was at risk of an earthquake potentially even bigger than last week’s magnitude 7.0 quake. Part of their presentation is particularly chilling in light of what would happen less than two years later: “This means that the level of built-up stress and energy in the earth could one day be released resulting in an earthquake measuring 7.2 or more on the Richter Scale. This would be an event of catastrophic proportions in a city [Port-au-Prince] with loose building codes, and an abundance of shanty-towns built in ravines and other undesirable locations.”

Earthquakes are still impossible to predict with precision; in the words of one of the geologists who predicted the Haiti quake, “It could have been the next day, it could have been 10 years, it could have been 100… This is not an exact science.” But researchers have identified a handful of seismic zones around the globe that are storing up especial amounts of stress and are particularly hazardous. Browse through the gallery for a world tour of the planet’s most seismically vulnerable regions.

By Aline Reynolds

Image: USGS

You’ve seen this ad before.

Weight loss program Jenny Craig’s spokeswoman, actress Valerie Bertinelli, is hanging out in a gleaming white “lab,” surrounded by guys in thick-framed glasses and lab coats. She gleefully announces that people on the Jenny diet lost two times as much weight as those who were on the other big diet program (read: Weight Watchers). She also claims that the results were an outcome of a “major clinical trial run by serious lab geeks.”

Now, Weight Watchers has lashed back, dragging Jenny to court–alleging that the ad campaign makes “deceptive claims” about its success rate.

The complaint was filed in the U.S. District Court for the Southern District of New York, according to AdWeek, and it said in part:

“The trials cited by Jenny Craig (available on its Web site) are, in fact, two separate studies, conducted 10 years apart for entirely different purposes than comparing the efficacy of the Jenny Craig and Weight Watchers weight-loss programs … The Jenny Craig ‘trials’ do not relate to WW’s current offerings.”

So a New York court has now granted Weight Watchers International a temporary restraining order and has prohibited Jenny Craig from using these comparative claims of superiority in its current ads.

In the ad, Bertinelli cheerfully declares, “I love science.” We might suggest she say instead, “I love putting a patina of scientific authority on whatever flimsy claim our marketing people are peddling today.”

Related Content:
Discoblog: Fast Food Joints Lie About Calories (Denny’s, We’re Looking at You)
Discoblog: Heart-Stopping Cinematic Excitement: Guess How Much Fat Is in Movie Popcorn?
80beats: Diet and Exercise in a Pill: Experimental Anti-Obesity Drug Could “Trick” the Body
80beats: A Victory for the Atkin’s Diet? Not so Fast.

Video: Jenny Craig

[Kari, Grant, and Tory from The Mythbusters will be on The Late Late Show with Craig Ferguson tonight, so it seems like a good time to post this.]

In case anyone was wondering if I would succumb to the bright lights of Hollywood, the answer is, of course: duh.

Last week I attended a wonderful party in Pasadena, thrown by the Discovery Channel for their 25th anniversary (my pictures from the party are on Flickr). My friend Katherine Nelson secured an invite for me; she does PR for the channel and we met at Comic Con in 2008 when I was tagging along with My Close Personal Friend Adam Savage™. Last week I happened to be in LA working on my sooper sekrit project, and that timing happily coincided with the party.

I’m not used to high-end parties, so I wasn’t sure what to expect. I decided to go all out and wear a tie. Go me.

I got to the hotel, located somewhere down twisty passages in Pasadena all of which look alike, and started wending my way to the party itself. As I randomly walked, I wondered to myself what celebs might be here, and at that very moment happened to see Ed Begley, Jr.

OK then.

When I finally reached the actual party location, I was happy to see Katherine taking pictures of Kari Byron, Grant Imahara, and Tory Belecci from Mythbusters! I hadn’t seen Kari in a couple of years (I moderated a panel with three of them in Canada), but I saw Grant and Tory at Comic Con last year. It was nice to see them again. I hung out a bit with them, and, as always, found them to be fun and charming and pretty much what you see on TV. At least, they’re nice enough to a dork like me.

There were lots of Discovery Network celebs there (as well as a giraffe). I was completely unashamed to horn in on Stacey and Clinton from "What Not to Wear" and chat for a second. I was thrilled to get a chance to talk with Annabelle Gurwitch, who is on Planet Green now, but I know her from watching "Dinner and a Movie" on TBS a few years ago, and she was exactly as I had hoped: funny and sassy and totally approachable. Also? A doll. There, I said it.

I also dorked a bit when I got a chance to say hi to Kat von D from "L.A. Ink", since she wasn’t in the shop the day I got my tattoo. It was totally cool to show her my tattoo (patience; my show is supposed to air next month) and thank her for the experience. We swapped a couple of stories, and I found she was like everyone else I met at the party: approachable, open, and interesting.

In fact, if there was any disappointment with the party (besides not being allowed to actually eat the cakes made by the bakery from "Cake Boss" and realizing after I had gotten back to my hotel that the Meteorite Men were there and I missed them) it was of the snarky variety; that is, no one was a jerk. I mean, c’mon! This was a Hollywood party! No cocaine? No obnoxious divas?

Could it be that the portrayal of Hollywood in Hollywood films has been Hollywooded? Hmmm.

So all in all it was a fabulous event with a lot of people having lots of fun. It makes me wonder… could it be that because there is a science bent to the networks (not all the shows, but many) the party was more about the fun and less about the personalities? Hmmm again.

Maybe not. But still. Science is cool.

As a parent, I spend a lot of time worrying about my daughter. That’s part of the job description. But what they don’t tell you is exactly how to figure out what to worry about.

I suspect that in Fluvanna County, Virginia, that’s a problem too. It’s there, you see, that a bunch of parents are upset about an abstinence-only sex education class. Now, I’d certainly be upset if they offered such nonsense in my daughter’s school, since it has been shown repeatedly that sexual education based on abstinence only doesn’t work at all.

But that’s not what has Fluvanna County parents unhappy. Instead, it’s that students in the class were asked to fill out a survey without first notifying the parents. That’s against the school district rules, not surprisingly. And, to be fair, I’d want to be notified as well so I could look at the survey.

But really, that’s a minor, minor point compared to the fact that their children are not only not getting a real sexual education, but by taking an abstinence-only class they will be more open to STDs and teen pregnancies.

The program in question is called Worth Your Wait. I looked over their website, and will readily admit that a lot of the advice they give is fine: self-control is important, it’s best to wait until you’re ready, and so on. But that hardly matters, since the very basis of what they’re saying is known not to work. It’s like having a website saying drinking a glass a water a day will cure AIDS, and it’ll also hydrate you. Sure, the latter is true, but the overall message is bunk.

It’s too bad, because it’s an enticing idea: teach your kids to not have sex, and like magic, they won’t! But it’s a crock. It’s worse than that, really, because study after study show this very clearly: kids still get pregnant, kids still get STDs, and in fact with abstinence-only education they tend not to get educated on how to practice safe sex, so pregnancies and incidents of STDs actually go up for AO educated children.

But why let research and reality get in the way of dogma?

Tip o’ the chastity belt to Nicole Gluggerflurnaven.

“A 45-year-old man was referred for investigation of an undescended right testis by computed tomography (CT). An ultra-sound scan showed a normal testis and epididymis on the left side. The right testis was not visualized in the scrotal sac or in the right inguinal region. On CT scanning of the abdomen and pelvis, the right testis was not identified but the left side of the scrotum seemed to be occupied by a screaming ghost-like apparition (Figure 1). By chance, the distribution of normal anatomical structures within the left side of the scrotum had combined to produce this image. What of the undescended right testis? None was found. If you were a right testis, would you want to share the scrotum with that?”

And for your enjoyment, Figure 1 (the free PDF is available here):

Thanks to Tom for today’s ROFL!