Submit a link Features Reviews Podcasts Video Forums More ▾

TV, video games, or Internet: Which activity makes teenagers fat?

I talk a lot about the importance of context in understanding science. The results of one, single research paper do not tell you everything you need to know on a given subject. Instead, you have to look at how those results fit into the big picture. How do they compare to the results of other studies on the same subject? Have the results been independently verified? How do the specific experiments being done influence what you can and cannot say about the results? What questions aren't answered by the study, and what new questions does it bring up?

You should be thinking about that every time you see anybody talk about the results of a single, new study. Without context, you get situations like this one, described by Travis Saunders on the Obesity Panacea blog:

Earlier this year my friend and colleague Valerie Carson published an interesting paper examining the health impact of various types of sedentary behaviour in a sample of 2500 children and adolescents. They created a clustered risk score (CRS) which took into account a child’s waist circumference, blood pressure, cholesterol, and inflammation, and then examined whether it was associated with 3 different measures of sedentary behaviour – accelerometry (an objective measure of movement), self-reported TV watching, and self-reported computer use.

Here is what they found (emphasis mine): For types of sedentary behavior, high TV use, but not high computer use, was a predictor of high CRS after adjustment for MVPA and other confounders. Here is what the Daily Mail had to say: Watching TV most damaging pastime for inactive children, increasing risk of heart disease.

Last month, our group in Ottawa published another paper (led by Dr Gary Goldfield) looking at different types of sedentary behaviour and heart disease risk factors in a cohort of overweight and obese teens (in contrast, the earlier study was on a sample of nationally representative youth). Interestingly, we found that neither TV time nor computer time was associated with increased risk in this group - in our dataset it was video games that were by far the most important sedentary behaviour.

Why is this a problem? Put yourself in the shoes of someone who just read the Daily Mail article, and who now believes that TV viewing is the single most damaging sedentary behaviour for kids to engage in. What reaction are you going to have when you read a similar article about our new study, suggesting that TV viewing and computer use aren’t important at all, but that video games are actually “the most damaging activity an inactive child can indulge in”?

As the source of this problem, Saunders rightly calls out journalists for pushing every individual study as a "GROUNDBREAKING NEW FINDING". It is, unfortunately, rare to find TV and newspaper coverage that treats new studies in context, rather than as the final word. But to that, I'd add university PR people. The sad truth is, with newspaper layoffs, many of the people writing about science aren't specialists. They cover city council one day, school board the next, and a new research finding after that. The press releases they get (and I know, because I get those press releases, too) push GROUNDBREAKING NEW FINDINGS not research that fits into a larger context. It's the journalists job to know better. But it's also the university's job to not manipulate journalists.

Scientists: How do ethics and culture shape your work?

Recoding Innovation is a National Science Foundation-funded documentary that's basically about the anthropology of science and engineering.

If you're a scientist or an engineer, you can participate. How does your culture, values, and beliefs make your work happen? The idea here is that ethics aren't something that hold science back. Instead, applying ethics helps scientists and engineers be innovative. It's a cool idea, and I'm looking forward to watching the finished documentary. The video above includes a short example of the kind of stories the editors are looking for.

Submit your story by January 1.

Video Link

The trouble with lab mice

You've probably seen this caveat pretty often: Just because a study that uses mice as subjects produces a specific result, doesn't mean you'd get the same result using human subjects. Mice are handy research animals, but they aren't perfect analogues to humans. A mouse study is a stepping stone towards better evidence. It is something we do because there are potentially useful ideas that we should not try out on humans first. But mouse studies should not count as incontrovertible proof of anything.

Usually, when that caveat comes up, the person giving it is talking about fundamental differences between mouse biology and human biology. For instance, a mouse might only need one copy of a genetic factor to grow normally. Meanwhile, a human needs to have both copies or risk altered sexual development.

But there are other problems with mice, problems that have more to do with how we select, breed, and raise mouse models. In a fascinating three-part series on, Daniel Engber looks at how we undermine the usefulness of our own lab mice, and the risks we take when we do so.

If you put a rat on a limited feeding schedule—depriving it of food every other day—and then blocked off one of its cerebral arteries to induce a stroke, its brain damage would be greatly reduced. The same held for mice that had been engineered to develop something like Parkinson's disease: Take away their food, and their brains stayed healthier.

But Mattson wasn't so quick to prescribe his stern feeding schedule to the crowd in Atlanta. He had faith in his research on diet and the brain but was beginning to realize that it suffered from a major complication. It might well be the case that a mouse can be starved into good health—that a deprived and skinny brain is more robust than one that's well-fed. But there was another way to look at the data. Maybe it's not that limiting a mouse's food intake makes it healthy, he thought; it could be that not limiting a mouse's food makes it sick. Mattson's control animals—the rodents that were supposed to yield a normal response to stroke and Parkinson's—might have been overweight, and that would mean his baseline data were skewed.

Part 1: The unhealthy lives of industrialized lab mice
Part 2: The trouble with focusing so much research on one single mouse species
Part 3: Why the naked mole rat (and the Burmese python) can help

Faster-than-light neutrino update: What's going on behind the scenes?

The publication process for a research paper about physics works a little differently than other subjects. That’s because of arXiv.

Read the rest

How do we know that the moon isn't cheese?

Sean Carrol explains why there are some ideas science doesn't have to test in order to know that they're ridiculous. (Via Bora Zivkovic.) Maggie

Space dust: Your tax dollars at work

Your tax dollars build bridges. They pay the salaries of teachers and firefighters. Tax dollars help put people through college, provide a safety net for the elderly and the disabled, and pay for fighter jets and nuclear bombs.

Read the rest

Meet Science: How clinical trials work

Did you know that, with a properly conducted series of clinical trials, it can take upwards of 20 years before a medical discovery makes it from the lab to the hospital?

Judy Stone, an infectious disease specialist who does clinical research, has a guest post on the Scientific American blog network today, explaining the basics of clinical trials—where they came from, and how they can go wrong.

She's going to be publishing a series of posts on this topic, and is looking for input on what you want to know about clinical trials. Disclaimer: As a clinical researcher, Stone has a goal here. She'd like to see more people volunteering for clinical research, and part of what she's interested in is the gaps in knowledge that make people wary of participating, or leave them unaware that they can participate. Your input would be helpful.

Image: Pills Phial, a Creative Commons Attribution Share-Alike (2.0) image from luca_volpi's photostream

Clinical trials seek to learn whether a drug (or device) works as expected—it’s unknown, until tested in people. That’s why early phase trials use only a few people, and more are added as experience is gained. Sometimes unexpected discoveries are made along the way. For example, Rogaine was discovered by an astute clinician researcher during a clinical trial studying high blood pressure. The drug, minoxidil, originally under study as an anti-hypertensive medication, was serendipitously found to have the unexpected side effect of stimulating hair growth, prompting a whole new line of products for baldness.

Similarly, Viagra was discovered by accident. Sildenafil, the generic form, was being studied as a treatment for angina, as it dilates blood vessels by blocking an enzyme, phosphodiesterase (PDE). While not very effective for angina, it was found to prolong erections, stimulating the whole “life-style drug” industry. Fortunately, PDE inhibitors are now being found useful for a host of important medical conditions, ranging from pulmonary hypertension to asthma and muscular dystrophy.

Of course, not all inadvertent discoveries have such rosy outcomes.

For example, Diethylstilbesterol (DES), a synthetic estrogen, was commonly prescribed in the US 1938-1971, to help prevent miscarriages. It was only after many years that DES was found to cause a rare type of vaginal cancer in daughters of exposed women. Later, other types of cancers showed up as well, in small numbers.

Via Aaron Rowe

Caffeine hallucinations: Why "Letters to the Editor" matter in science

Letters to the Editor are an interesting feature of peer-reviewed scientific journals. The function of this section varies from journal to journal, but, in general, this is where you’ll find things like critiques of research published in previous issues, and short write-ups on findings that don’t yet warrant their own big, formal research paper.

Read the rest

Meet a paleontologist

What does a scientist do all day? The Smithsonian's Matthew Carrano explains his job as a paleontologist, what he hopes to discover, and why he made a career out of dinosaurs.