Evidence-based Medicine?

By: | January 12, 2011

Scientists know a lot about infectious diseases. But a new study in the Archives of Internal Medicine finds that the treatment guidelines created by the Infectious Diseases Society of America (IDSA) are based on imperfect evidence. Only one in seven treatment recommendations relied on evidence from a randomized controlled trial, the gold standard in medicine.

In a randomized trial, participants are randomly assigned to one of two groups—the “treatment” group or the control group. The control group receives the standard of care, say ibuprofen for a headache. The treatment group receives whatever new-fangled drug or intervention the researchers want to test, say meditation or Valium.

At first blush, this apparent lack of high-quality evidence may seem like cause for outrage. But ask any medical researcher, and they will tell you that clinical trials are crazy expensive. In some cases, they aren’t even possible. And in other cases, they’re just plain stupid: We don’t need a clinical trial, the authors point out, to tell us that staying far away from ticks cuts our risk of contracting Lyme disease, nor do we need a clinical trial to tell us that nurses and doctors should wash their hands to prevent the spread of infections. Continue reading →

Science Metaphors (cont.): Mantle Drag

By: | January 11, 2011

The older I get, the more people I know who have lost what they could not afford to lose.  I’ll repeat:  lost means gone, unrecoverable, not coming back; and what these people lost, they still need and want.  The problem is nearly universal and has no obvious solution, or rather, the solution is idiosyncratic and not necessarily found by looking.  Somehow it just, more or less, sorts itself out.  Meanwhile, daily life must be slogged through as gracefully as possible, looking as normal as possible, staying on the surface.  Otherwise you won’t get invited to dinner parties.  Geophysicists have an inelegant phrase, “mantle drag.” Continue reading →

Where Did All the Universe Go?

By: | January 10, 2011

One of our favorite science writers has just published a terrific new book, The 4% Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality. So I nabbed author Richard Panek, who just happens to be an LWON blogger, for a Q and A session.

Q:  Your book’s really provocative. What first drew you to the subject?

A:   The central idea—that what we’ve always thought was the universe in its entirety, for thousands of years, is only 4% of what’s actually out there—is absolutely wild. When I first heard about this idea at astronomy conferences about ten years ago, I thought it was too wild to be true.

Continue reading →

Battles So Fierce, They Could Almost Be Human

By: | January 7, 2011

We lost one of the grand patrons of the nerdy childhood this past week. Milton Levine—Uncle Milton to you—sold his first Ant Farm in 1956, launching a mail-order formicarium empire and inspiring, for a time at least, millions of junior entomologists. I made do with older ant-watching techniques, spending countless childhood summer hours belly-down on the sidewalk behind our garage, nose-to-mandible with the red ant colonies that thrived there.

I was fascinated by their busy digging, and both alarmed and thrilled by occasional gruesome spectacles. I remember thinking how like Paleolithic mammoth-hunters the scores of ants subduing and dismembering a vastly larger caterpillar seemed, unable to look away as the creature writhed and squirmed under the ants’ devastating, coordinated attack.

The more advanced ant observer will eventually encounter all manner of human-like behaviors, from weaving (nests, in trees) to farming (fungi, underground) to herding and “milking” other animals (aphids, disgusting). But by far ants’ most anthropomorphous characteristic is the facility with which they go to war with their neighbors. Continue reading →

The economics of extinction, one tuna at a time

By: | January 7, 2011

There are many ways to celebrate a new year—for me, it’s by becoming a “person of LWON” and joining some of my favorite science writers at this commodious corner of the web.

For fishmongers at the massive Tsukiji market in central Tokyo, however, there’s no more festive way to ring in the New Year than with the first bluefin tuna auction of the season. That happened on Wednesday this year, with the first fish selling for an unprecedented $396,000. Some are calling the record price auspicious—surely $1000-per-kilo fish must be a sign of recovering luxury markets in Japan and China.

At 324 kilograms, this tuna was a relative welterweight—the largest Pacific bluefin can weigh 450 kilos. But the first sale of the year is considered especially lucky, and delivers a guaranteed PR boost for the winning bidders, in this case owners of upscale restaurants in Tokyo and Hong Kong. But there’s a distinct rummy whiff to this kind of luck. Continue reading →

A New Year’s Diet: Mind Control

By: | January 6, 2011

First week of January. Like everybody else in America, I’m on a diet.

I’ve tried lots of diets over the years, and no matter how simple the particular rules — Fat is bad: stick to salads, whole grains and fruit! No no no, fat is good: lay off carbs, and eat lots of meat. Count calories. Count carbs. Are you getting enough fiber? Eat cookies all day! — following them is never easy.

Eating is what neuroscientists call a complex behavior. It’s not reflexive, like a knee jerk or sneeze, but rather depends on lots of brain systems. Real, painful hunger, of course, triggers eating. But so can the smell of bacon, even if you’ve already had breakfast. If you’re starving on a lettuce diet, good old willpower can (I’ve heard) override your urges to eat. And this complexity isn’t just a human thing. For lots of animals, feeding motivations can change with body temperature, sleep cycles and mating opportunities. Dozens of brain regions and hundreds of different kinds of brain cells have been tied to eating.

Which is why this study I’m about to gush about is so (mind the pun) startling. Scott Sternson‘s team from Janelia Farm compelled mice to voraciously eat by switching on just one type of neuron in their brains. Perhaps more provocative, the researchers got mice to completely stop eating by activating a different type of neuron.
Continue reading →

A Pox on Your Hand

By: | January 4, 2011

On a crisp fall day in November 2008, a wildlife biologist killed a deer in Eastern Virginia. He slit the carcass open from breast to tail and removed the animal’s internal organs. Hunting knives are very sharp. And, in the process of field dressing the deer, he nicked his knuckle. I imagine he didn’t think much of it at the time. But the cut did not heal. Two weeks later he had a painful bump where the wound had been. By mid-December, the bump had become an angry purple nodule. Not surprisingly, he sought medical attention. Continue reading →

A Long Vanished Waterworld

By: | January 3, 2011

A few years ago, a colleague and I hired a cab to journey across the Sahara Desert, from a tiny oasis town to Luxor in the Nile Valley. Before we could head out, however, the driver insisted that we anoint ourselves with perfume he brought for the occasion–a ritual cleansing to protect us from evil spirits and the perils of our journey, the most likely of which was engine trouble. When we finally pulled into Luxor 12 hours later, the three of us were parched and coated head to toe in dust.  As I rehydrated in a hotel bathtub, I felt like Lazarus rising from the dead.

Even today, in the age of the internal combustion engine, a Sahara crossing is not to be taken lightly. So it’s no wonder that archaeologists have long dismissed the possibility that our ancient ancestors–early modern humans–ventured successfully across the Sahara more than 100,000 years ago, as they journeyed out of their southern homeland. The Nile Valley seemed a much easier route.

But new research strongly suggests that the Sahara would have been a land of earthly delights for early Homo sapiens. Continue reading →