David Souter has famously described the Supreme Court term from October to June as a period during which he undergoes an “intellectual lobotomy.” I had hoped that entering grad school and being surrounded constantly with the bloody edge of science would stimulate my curiosity. Unfortunately, after nine to ten hours a day of reading and thinking about science, I come home to find the well dry.

It’s not that I don’t want to write, it’s just that I don’t have nearly as much to say as I did before. In contrast, I now find a desire to come home and read fiction or watch good shows like Arrested Development.

These findings lead me to surmise that I have a limited capacity for thinking about science, be it focused or unfocused (how I see this blog) thought. When I was teaching science, actually, I rarely thought about it. Instead I thought more about grading, making exams, setting up labs. And during the summer, I wasn’t really forced to think about anything.

Perhaps (and I hope) this is an adjustment period, that my brain is undergoing a large intellectual transformation, akin to the burn of working out hard when out of shape, and that over time, my most powerful muscle (to use the term loosely) will strengthen and begin to desire the outlet of curiosity that this blog has been.

I’m stepping away because I have no obligation to stay, and writing as an “assignment” can sometimes produce a resentment that I do not wish to have. I will certainly keep the blog up, writing whenever the thought strikes me.

So thanks for reading. The purpose of my writing (other than simply a selfish exercise) is to try to convey the power, excitement, and controversy that science brings to our lives. All of these are important and need to be acknowledged. I hope I’ve succeeded at one time or another in getting that message across.

Remember, in the words of good old Descartes, “de omnibus dubitandum.”

I came across an interesting article in Nature News about the controversy surrounding a paper published in PNAS (Proceedings in the National Academy of Sciences, a big deal journal) about genetically modified (GM) corn and its toxicity in streams. The article in Nature News discusses the controversy this PNAS paper ignited among other scientists in the GM field (those who tend to support its use and development). The “attackers” wrote an open letter rebutting the methods used in the original study, and the study’s author said she received a large amount of inflammatory (negative) feedback, more than the usual objective disagreement.

While I always think controversy and rebuttal letters are valuable to the scientific project of distilling true principles out of our otherwise vague world, I was interested to hear about the more emotional aspect of some of this response against the original author’s methods (and thus validity of the paper). What I see in these “pro-GM” scientists are people fighting for their field. They know that all it takes is one or two papers elucidating the negative effects of GM-crops to sway public support away from them, and away from their research (cf. monarch butterflies, Europe)

Scientific research mainly benefits but also suffers from the fact that when something is published in a respectable, peer-reviewed journal, people believe it. Scientists read a lot of papers within their field (or subfield). Each paper is usually not a definitive statement on something, it’s a bit of evidence for or against something. Just because one paper is published claiming X does not mean a scientist believes X. It takes a number of papers claiming X in a variety of different angles through a variety of different methods. For sure, a paper, especially one in a well known journal, lends a good deal of credence to claim X but by no means proves it.

And yet, the public, which includes scientists outside of their own subfields, gives so much more credence to individual papers. All it takes is one paper to influence important policy decisions that affect that field. The public does not read Methods sections, where most of the internal debate often stems.

I have been guilty myself, many times probably on this blog, of drawing conclusions from science-news headlines without thoroughly scouring the papers with the skepticism perhaps they deserve. After all, it’s impossibly to be an expert in every field. What’s important for us all to remember is that each paper is just a small bit (however convincing) of evidence for or against something. Very few papers can single-handedly take down or erect a scientific belief.

So the next time you find yourself citing a paper (from reading it directly or indirectly through the news) as evidence for something, remember to take it with a grain of salt. The world could do with a bit more scientific skepticism.

in vitro meat

September 3, 2009

This is where most of us get our ground beef from. (credit: www.marlerblog.com)

This is where most of us get our ground beef. (credit: http://www.marlerblog.com)

Seed Magazine (my favorite science publication), has an interview with Jason Matheny of New Harvest, a non-profit organization aimed developing scalable and tasty meat grown on a petri dish (basically). Growing meat in a controlled environment like a petri dish is more environmentally efficient, in energy, in water, in land usage. As developing nations like China and India become wealthier, the demand for meat only increases.

Of course, the best scenario is that we all become vegetarians, both because it’s healthier and more environmentally friendly. However, I’m not quite there yet myself (my mind can’t quite overpower my evolved lust for high-protein, high-energy flesh) and so can’t demand that the rest of the world must be as well. If we assume that people are going to eat meat, why not have it come from a controlled environment, where fat content and every other chemical can be controlled?

Interestingly, the technology used to grow little bits of meat is hijacked from the field of tissue engineering, which aims to grow everything from skin to muscle to organ tissue. The limiting factor for tissue (be it for eating or healing) is getting the blood vessels built so the tissue can be sufficiently large. Vascularization of artificial tissue is very tricky thing that we haven’t quite mastered yet.

Thus, the applications for this technology would only be (for the present) in ground meat, where the small amounts grown in vitro (meaning in the lab, not in a real animal) could be put together like we’re used to. But still, ground meat comprises a very large part (Matheny claims roughly half, but I don’t have an independent number) of the world’s meat consumption and so could still have a significant impact.

You might react to this idea of eating meat grown in a test tube as just another part of our over-commercialized, over-scientificized (my own word), over-supply-chain-ized agricultural industry. We should be eating our meat from local, grass-based, holistic farms. I agree that the nice local farm alternative feels better (and IS better at the moment), but if we can produce meat that’s healthier, cheaper, significantly more environmentally friendly, and perhaps even tastier than our local farm, how long are you going hold out just on principle?

Imagine this scenario: you’re coming back through customs from a business trip, and the official suddenly asks if he can have your briefcase, which you give up, expecting the routine open…rifle through…close, only to have someone (perhaps a higher up) explain that the Department of Homeland Security needs to take your briefcase and thoroughly examine its contents. The official is probably fairly polite about it, but firm. He explains that if you just write down your address here, they’ll be sure to mail it back to within 30 days. Sound strange, or vaguely illegal? Well, get used to it, because DHS can now do that, except just not with paper documents.

From PC World:

The U.S. Department of Homeland Security has released new rules for border agents searching travelers’ laptops and other electronic devices, but the revised guidelines won’t quiet complaints from the American Civil Liberties Union.

The new guidelines, unveiled Thursday, continue to allow U.S. Customs and Border Protection (CBP) and U.S. Immigration and Customs Enforcement (ICE) to search electronic devices during border crossings without suspicion of wrongdoing. Both CBP and ICE are part of DHS.

Note the part about “without suspicion of wrongdoing.” I think many of us are at least used to (if not totally in agreement with) the idea that officials can search your car, your bag, your briefcase given probable cause. But introducing a certain level of arbitrariness seems beyond our (or at least my) civic understanding of what’s reasonable.

DHS has lots of language in their statement about protecting civil liberties and such, but merely saying that you’re going to do something in a directive doesn’t actually mean you’re going to do it.

The new directive came a day after the ACLU filed an Freedom of Information Act for more information regarding the policy, so it seems that they at least are sensitive to public concerns.

And to that extent, I’d really like to hear more information about why DHS thinks it necessary to search people’s documents without probable cause.

unpacking a statistic

September 1, 2009

A new study in the Archives of General Psychiatry reports that the percentage of Americans on antidepressants almost doubled from 5.84% in 1996 to 10.12% in 2005. The first thing that probably hits you after reading that is, “Wow, that’s a big jump in ten years.” The next thing might be something like, “I wonder what caused that big of a jump?”

To an educated (but generally ignorant in psychiatry) observer, a few initial explanations seem plausible:
1) The number of depressed people has simply increased, bringing with it the number of people on medication.
2) Cultural acceptance of depression as a legitimate physiological illness has grown, allowing more people to come out into the open and seek treatment they had previously avoided.
3) Our ability to diagnose the illness has improved, allowing us to catch and treat more cases.
4) Our acceptance of (and desire for) drugs to address our problems has increased (to, what many would say — although I’ll withhold judgment — is an unhealthy level).

The authors of the study mainly think it’s 1). In 91/92, the rate of depression in the US was 3.3% and rose to 7.1% in 01/02. This increase in depression itself is an interesting nugget. If fundamentally we think of depression as a physiological disorder, I find it hard to believe that our brain chemistry has really changed that much in ten years. Another explanation is that people are seeking out their doctors more for mental health problems, but then we start spilling into hypothesis 2) and possibly 4).

The authors also suggest an additional hypothesis:

5) Between 1996 and 2005, four new antidepressants (mirtazapine, citalopram, fluvoxamine, and escitalopram) were approved by the FDA for treating depression and anxiety. Furthermore, while the total promotional spending stayed the same, the percentage of that aimed directly at consumers (rather than physicians) increased from 3.3% to 12.0%. So, another explanation of the increase is simply that there are more, and more aggressively marketed drugs out there.

The point I’m trying to make here is that statistics like, “The percentage of Americans using antidepressants doubled between 1996 and 2005.” (from SciAm) and their handling in casual print or conversation often confuse or obfuscate all the issues really at work. Most of us, myself included, don’t put a lot of (or enough) thought into everything going on behind a statistic when we hear or read about them. We’re not critical, skeptical observers, and that’s dangerous.

It’s nice to get out the magnifying glass and do a little digging every once in a while to really understand what all these numbers actually mean.