...to Jamie, frequent commenter, mother of five, who successfully defended her dissertation today...
10 March 2010 in Science (General), Something different | Permalink | Comments (1) | TrackBack (0)
Since I'm in losing-the-baby-weight mode, I decided to add a few new cookbooks to the kitchen, all with healthful overtones. Having some new books around, and new recipes, always helps motivate me. I thought I'd post a brief review of the books I checked out from the library and decided to buy. Two are nutrition/diet books with a recipe section, one is a cookbook through and through.
The Flexitarian Diet, by Dawn Jackson Blatner.
I've been eating "flexitarian" for a couple of years now, without knowing it. The term "flexitarian" is variously defined. Some say it means "flexible vegetarian," i.e., you're basically a vegetarian but you're flexible enough to graciously accept a meat dish when it's offered to you. Others say it simply means a reduced-meat lifestyle: vegetarian most of the time, meat some of the time. At our house, we love meat and eat it frequently; but we have learned to use it in smaller quantities. I generally serve it either as a flavoring, or as a dish served in modest portions as part of a meal.
Blatner's cookbook/diet book offers five full weeks of controlled-calorie menus, plus recipes. The recipes are all given for single-serving portions, use a lot of convenience food, and come together quickly. Canned beans feature prominently. This book is especially good for those who are looking for some new ideas for quick and simple, healthful meals; those who'd like a lot of one-person recipes; and those who would like a pre-written meal plan. Like most diet books these days, it stresses low-fat eating more than I like, but that's easily fixed.
One that doesn't stress low-fat eating at all, and so suits me very well, is Eat, Drink, and Weigh Less by Mollie Katzen and Walter Willett, M.D. Yes, that Mollie Katzen, of Moosewood Cookbook fame. I have had Walter Willett's book Eat, Drink, and Be Healthy on my shelf for a long time -- his nutrition work comes from the comprehensive Nurses' Health Study. The writing is very compelling and common-sense, and earned my respect because he was not afraid to write "We don't know" where necessary. Anyway, when I discovered recently that he had collaborated with uber-food-writer Mollie Katzen on a diet book with recipes and meal plans, I snagged it. And I'm very glad I did.
Mollie fesses up: she is not a vegetarian after all! Here we have recipes by Mollie with meat in them. (not very many -- most are vegetarian...) And not just recipes, but meal plans. There are three weeks of controlled-calorie meal plans, plus one week's worth of a "portable plan" that can be eaten on the go or prepared with minimal kitchen equipment.
The nutrition advice is sound. There are nine "turning points" (things like "eat lots of vegetables" and "stay hydrated"); a new-and-improved food pyramid with veggies on the bottom where they belong and a special slot partway up that's just for dark chocolate; and a score card for ranking how your habits are improving with time. I wholeheartedly recommend this one. It's one of the best diet books I've read. Oh, I should add that many of the recipes are of the sort that are easily adapted for allergies and food intolerances -- swap one grain for another, that sort of thing.
Finally, a pure cookbook: How to Cook Everything Vegetarian, by Mark Bittman. I hesitated before buying this because I already have How to Cook Everything. I thought there'd be so much overlap that it would be a waste of money.
It's true that there is some overlap: the pizza sections in the two books, for example, are very similar, and both books contain lengthy discourses on cooking basics (which makes sense, given the title). But there is enough new material in here to make it worth buying the new book, I think. There are several techniques that are new to me in this book -- have you ever heard of "stuck-pot rice?" I hadn't -- think a sort of stovetop paella with a crispy crust -- and lots of new recipes, even in sections that you might think would just overlap, like desserts. And there is plenty of new material of the sort that Bittman does best: lists of variations on a theme, menu suggestions, charts that show you how to put together combinations of ingredients. Plus there's lots of good technique instruction, and introduction to some more exotic things like making your own seitan (that's mock duck) or cooking with sea vegetables.
What all three books have in common is this: they will help you cook and eat with less meat, while refraining from moralizing about it. And that is something I really appreciate.
Popular Mechanics remembers five banned toys of yore, including the "Atomic Energy Lab."
Called "the most elaborate Atomic Energy educational set ever produced" by the Oak Ridge Associated Universities, this sophisticated science kit contained four types of uranium ore, its very own Geiger counter and a comic book called Learn How Dagwood Splits the Atom. A form on the back of the instruction manual allowed a burgeoning Ernest Rutherford to send a note to New Haven, Conn., bearing the message, "Gentlemen: I need replacements for the following radioactive sources, (check which): ALPHA____, BETA _____, GAMMA ______ or CLOUD CHAMBER SOURCE____."
Sweet.
Mechanical engineer and inveterate tinkerer Bill Gurstelle fondly recalls the Atomic Energy Lab, saying, "everybody wanted that kit." Nowadays, he adds, "science kits are just sugar and salt." This kit appeared 21 years too soon—the as-yet-nonexistent CPSC never got a chance to ban it.
Ah, those were the days.
28 February 2010 in Gadgets, Pop Culture, Risks & benefits, Science (General) | Permalink | Comments (0) | TrackBack (0)
I just learned that MathSciNet has a "collaboration distance finder" with a button for Paul Erdos, enabling anyone to figure out his or her Erdos Number (think "six degrees of Kevin Bacon," only for scientists and mathematicians collaborating on papers rather than actors appearing in movies together.).
I don't appear in MathSciNet's database, but my late academic advisor does, and I have appeared as co-author with him on a paper, so I was able to figure mine out. At most, it's 5.
As far as I know I don't have a finite Bacon Number.
09 January 2010 in Mathematics, Science (General), Something different | Permalink | Comments (3) | TrackBack (0)
OK, so now that we know that much of the global-warming raw data was thrown out, supposedly back in the 80's, so that none of the models relying on that data can be checked, I have a question.
What exactly does the citation tree look like?
Who cites that data that can't now be reviewed? Who cites the models built on that data? Who cites the people who cite the models built on that data?
It's probably relatively easy to build a straightforward citation tree, since those links are all documented and hyperlinked in places like the Science Citation Index (SCIFINDER). Harder would be to exclude the citations that are made merely as a nod to predecessors or for completeness in the review of the relevant literature, because to be fair what we're interested in is not hat-tips, but documentation of work building on previous work, taking it for granted that said previous work was rigorous.
Look, I've written a literature review, done it a couple of times in fact. I've written a model (not a very GOOD one), making assumptions which I supported by arguing from other people's data. I'd be pretty pissed off if I found out that those other people didn't actually, y'know, HAVE the data they said they had, especially if they knew it for 20-plus years and sat on that truth while other people decided it was a good idea to trust them and base their graduate theses or maybe even entire research programs upon that trust.
01 December 2009 in Science (General) | Permalink | Comments (1) | TrackBack (0)
I continue to follow the so-called Climategate stories with great interest. This morning the most interesting comment thread appears to be at the NYT dotearth blog, with many comments from a variety of people including the apparently technically trained and from both "sides" of the AGW debate, if it can be said to have clean sides.
Let's talk a little bit about the "consensus," the one that supposedly includes
thousands and thousands of the well-informed. Here is a little Venn diagram for you:
PEOPLE WHO HAVE AN OPINION ABOUT AGW (anthropogenic global warming)
Here we have some nested groups. General public is on the outside. Within that, laypeople with enough technical education -- they paid attention in high school or college science classes, they may have an amateur interest in science, etc. -- to understand the arguments about it that appear in newspapers, magazines, or the popular literature.
Within that, technically trained scientists, engineers, statisticians, and the like. I am a member of this group. We know how research is supposed to work and maybe we know a bit about how it really works. We might at some point have attended a seminar or taken a class on climate change, for instance, and at any case we know quite a bit of physics, mathematics, statistics and the like, and are used to reading and evaluating papers. The key feature of this group: We are all pretty sure that if we wanted to take the time to read the climate-change literature, take a look at the code, we could make an educated and independent judgment about it.
A bit farther in, climatologists and oceanographers and geologists, perhaps a few biologists who specialize in species affected by climate change, earth scientists in general: the sort of people who are expected to be familiar with the literature on AGW. They know the research intimately.
And then in the middle, a much much smaller group: those climatologists, oceanographers, geologists who actually produce the research, write the papers, design the models, manage and manipulate the data.
I have no doubt whatsoever that, as you move inward from circle to circle, you see that a greater and greater fraction of the people are convinced that (a) the globe is warming, (b) it's caused by human activity, (c) there's something we could do about it. That's what you call a "consensus."
What's not clear to me as a member of the third group from the center: How much of that conviction rests heavily on the integrity and good judgment of the people farther in, and on the soundness and objectivity of the peer-review process? This is especially important when you consider the interface between the two centermost circles -- because those second-ring people know enough and are familiar enough with the literature to critique the research of the inner-ring people, and then have the authority to add their voices to the "consensus" that is supposed to carry so much weight.
I rather suspect it's a lot. I'll raise my hand right now and tell you that I am a trained scientist who has generally assumed the peer review process regarding AGW to work the way it's supposed to, and has assumed good faith and rigorous adherence to professional values on the part of the global-warming researchers (I don't assume they are unbiased -- who is?). We're seeing a crack in that facade. It's clear that the values are compromised at major research facilities. That there's been an attempt to compromise the peer review process -- whether it has been compromised isn't clear, we haven't heard from the journals as far as I know. My assumption wasn't valid. Is my part in the "consensus" (such as my part was) back to square one? Maybe so.
28 November 2009 in Current Affairs, Science (General) | Permalink | Comments (0) | TrackBack (0)
Interesting discussion at Althouse about the human interchanges revealed in the so-called "climate-gate" email leak. Actually, interesting discussion in a lot of places, but I'll just pick Althouse to start.
I write this at a time before the emails are confirmed to be completely genuine, and I write as a global-warming agnostic. It is reasonable to take prudent steps to alleviate the problem as long as there is a significant consensus among climatologists that there's a problem and there's something we can do about it, as seems plausible; it is also reasonable to continue to take data, to publicize raw data, and to keep objectively re-evaluating the data we have in preparation for revising those steps if necessary. Really, that's the sort of thing I would say about any kind of research that seems to demand Action Be Taken -- look at the health recommendations of heart-disease researchers, for example.
But there's nothing terribly shocking to me about how the climatologists are apparently behaving in these e-mails. And I am not saying this because I believe climatologists to be peculiarly biased or peculiarly political-minded.
Having got out of the academic research business immediately after receiving my doctorate, my experience with the writing and submission of scientific papers is limited. I have served as peer reviewer exactly once. My name appears on a couple of papers that I didn't write (and didn't ask to have my name attached to). I chose not to put in the work to finish or to submit the papers that were based on my thesis research.
That's a long caveat for this observation: Scientists and engineers are subject to human nature just like everybody else.
Because "objectivity" and "adherence to the data" are explicit values of our profession, I think the human tendency to let our feelings about people influence our beliefs about their competence, or to ignore data we don't like, or to nudge our conclusions in the direction of our own ideologies, are probably mitigated relative to many other professions. (Which is why "Show me the data" is a demand that will always have teeth.)
But those tendencies don't go away, and they never quite let go their sway over people.
Every once in a while you hear someone sniff, "We're scientists, we make recommendations based on objective observations" -- as if the mere fact of "being a scientist" is a guarantee that he or she will behave like scientists are supposed to. (What would you think of a sitting congressman who stated, "I'm an elected official, therefore you can be sure that I always act in the interest of my constituents and the good of the country?") It would be better for scientists and engineers to acknowledge that they must have biases, being human, and that those biases always exert a pull on their work, and then do their best to overrule them with the rational mind, to root them out in the service of the values of the profession.
One way to root them out is to show your data to someone who disagrees with you, of course, and let him or her have their say. That's one of the things which peer review is supposed to accomplish, but it's also the sort of thing that one could do in private, as a preliminary exercise or test of one's own conclusions. How solid are they, really? Can you really say "incontrovertible?" That's almost like saying your theories are "untestable." Which is treading close to saying that they are not scientific statements at all.
Anyway, my point is just that there's nothing special about climatology, or about other lines of research with policy implications, that make the scientists and engineers who are involved in it peculiarly subject to the whims of human nature. You see it everywhere you look hard enough. Maybe that's just another way of saying that everything is fraught with politics, and it doesn't matter how petty the politics is -- we could merely be talking about intradepartmental politics, or hunger for power within one single research group in one department in one corner of one university in the middle of nowhere -- it still gets deep into people and makes them forget the higher values of their profession.
23 November 2009 in Politics, Science (General), What's Wrong with the World | Permalink | Comments (0) | TrackBack (0)
I just finished reading a book that's been out for several years but that I ignored until recently, when I thought I might need a corrective to all the diet books I read last year while I was losing weight: The Obesity Myth by Paul Campos. It's been a while since I deliberately read something that I expected to disagree with -- a practice I recommend heartily!
I was surprised to find that the book was in more than one way a wake-up call for me.
The basic thesis of the book is that our public policy towards obesity, and the amount we spend in public and private dollars to combat obesity, doesn't make sense for three reasons.
Number one: there's no credible evidence that obesity in and of itself (except at the extremes) causes health problems.
Number two: there's no credible evidence that losing weight in and of itself makes obese people healthier.
Number three: We're not getting much bang for our buck anyway, since the money and effort we've poured into the goal of getting people to lose weight is not resulting in weight loss.
I will begin with several significant caveats. I am not entirely convinced by Mr. Campos's review of medical data. There is not that much of it; I would like to see a much more thorough and detailed cataloguing than is present in this book, one much more like Gary Taubes' analysis in Good Calories, Bad Calories. I am also certain that some of Campos's data points raise questions that require answers before one can come to a conclusion. (One example: he writes that, excluding extreme thinness and fatness, life expectancy increases as you go from lower to higher BMIs. I thought: Now wait a minute -- life expectancy also increases as you get older, and people gain weight as they age, so shouldn't there be a correlation there anyway?) Third, he seems to sort of selectively criticize and praise the practice of controlling for confounding variables. I agree that this statistical tool can be used judiciously or maliciously, but Campos does not explain why he says it's justified here and not there. Has he proven that "there's no credible evidence" that obesity causes illness? I don't think so.
However, I think he does succeed in showing something a bit less ambitious: that the evidence is not nearly as strong as most people assume it is based on media reports and public policy recommendations. Five arguments he made struck me as very persuasive, if they are true, of this less-ambitious thesis. I feel I have to add that caveat because I think Campos needs more evidence to demonstrate that they are true. But if they are true, I agree with him that they call into question the obesity-health connection.
(1) To demonstrate that obesity causes health problems, most of the studies had to exclude smokers. (He says this isn't legitimate; I say it is; but regardless, the following point still stands.) After you exclude smokers and maybe a few other classes of people, the number of deaths in the studies are small. Nonsmokers in one study had a less than 1-in-600 chance of dying of cardiovascular disease; thinner nonsmokers were less likely to die than fatter nonsmokers, but the number of excess deaths attributable to obesity alone is perhaps not high enough to justify the effort we're putting into combating obesity. At the very least, the harm of obesity is likely dwarfed by the harm of smoking. Which do you suppose our country spends more on: attempting to lose weight and get people to lose weight, or attempting to quit smoking and get people to quit smoking?
(2) Public policy advisory boards have an astonishing level of conflict of interest. It goes beyond the level of "this study was funded by that industry which has a stake in the findings." For example, he says that a claim of a strong international consensus that BMI>25 was based largely on the report of a World Health Organization panel that "consisted entirely of physicians who run weight loss clinics." Even if you assume a good-faith effort, could such a group really be objective?
(3) Campos says that studies that purport to show a connection between weight loss and improved health have not adequately controlled for the effect of improved nutrition and increased physical activity; and news reports fail to distinguish this effect too. Campos gives an example of a study where participants significantly increased their physical activity and as a result both lost a few pounds and improved some measures of their physical health: the media reported it as "losing a few pounds can improve your health." It is now very well established that, independent of your weight, physical activity makes people healthier. (I wrote about this in my post about reasons to exercise.) Because of that, it's obvious that a study purporting to show that obesity causes poor health must control for physical activity. Campos says that many of the studies don't have that control.
(4) Taking all the methods together, the act of losing weight introduces significant health risks that have not been adequately compared to the risk of not losing weight. For instance, he claims that bariatric surgery is shockingly dangerous (the risk of death within a month of the surgery is somewhere between one in 20o and one in 50!). Is it really proportionally dangerous not to have bariatric surgery, especially at the lower-BMI end of the market? He says there are health risks associated with traditional methods of weight loss as well.
(5) Being "BMI-normal" or less appears to cause some serious diseases that obesity protects you from. Osteoporosis, which can lead to deadly hip fractures, is one such disease; there are others. When you include these "diseases of mild thinness," does the relative danger of mild obesity start not looking so bad?
Since it's true that physical exercise really is well established as something that improves health, it's apparent to me that it's dangerous to suggest "You should exercise to lose weight, because the weight loss makes you healthy." Physical exercise is not actually that good at bringing about weight loss. If someone starts exercising to lose weight for their health, they could really be improving their health and yet not see a weight loss; and will they then conclude that it's not doing any good, and so quit? Or will thin people dismiss exercise because they don't think they need to exercise to be thin?
* * *
Not all of the book is about the medical research. A large part of it is about the social pressure to be thin. This is the part of the book that, for me, was a wake up call. Because I've probably been contributing to it a bit over the past year, as I chronicled my own struggles with weight loss. I hope on the whole my writing has been positive, because I firmly believe that physical activity and well-balanced, not-excessive nutrition are worthy goals in and of themselves, even if they don't result in thinness, and I want my writing to have reflected that. Still, I measured my success last year largely in the pounds that came off the scale, and I'm a bit more aware that I emphasized the number too much.
Even in my personal experience, Campos's points ring true. I've been telling people that I've never felt better since I lost the weight -- but maybe I feel better because I'm so much more physically active, and the weight loss is just a side effect.
And then there is the lengthy discussion of why we criticize obesity so much. We say it's about health, but is it really? Particularly if the medical evidence against it turns out not to be so damning? Campos makes a strong case that it's about the need for us to have some kind of social pariahs among us, a need to feel superior to others. (Hoo boy, that hit home. Consider this post. And consider that it was after I started to lose weight that I started to write that I was "conquering gluttony." Look, I'm getting thinner! It proves I'm becoming a better person!)
A point I found especially interesting: Campos, a Mexican-American, argues that the freedom to look down one's nose at fat people has functionally created a way for elite, highly-educated white people to continue to sneer at low-income black and Hispanic people, without having to feel guilty about it:
Precisely because Americans are so repressed about class issues, the disgust the (relatively) poor engender in the (relatively) rich must be projected onto some other distinguishing characteristic... In 2003, any upper-class white American liberal would be horrified to imagine that the sight of, say, a lower-class Mexican-American woman going into a Wal-Mart migt somehow elicit feelings of disgust in his otherwise properly sensitized soul. But the sight of a fat woman -- make that an "obese"-- better yet a 'morbidly obese' woman going into Wal-Mart ... ah, that is something else again.
He has got a real point (made only clearer by the fact that some upper-class white people would be disgusted merely by the mention of the Wal-Mart, without any reference to obesity at all).
Race intersects with obesity culture in another way I wasn't aware of. According to Campos, girls and young women in the U. S. who are black or Hispanic are much more likely to have a positive appreciation of their own bodies than are white girls. They are more likely to evaluate their self-worth independently of their appearance. They are also likely to have a higher BMI. And (this is the kicker) at least for African-American women, the denonstrated connection between obesity and poor health is even weaker than it is for white women. Campos seems to suggest that public health authorities are actively promoting educational campaigns that will sensitize young black and Hispanic women to the dangers of obesity. If this is true, it is really hard not to come away with the impression that some public health policy amounts to "Let's make black and Hispanic girls feel bad about their weight."
So here's my final word on the book. It's not perfect. It's flawed. It raises questions that go unanswered. I'm not convinced of Campos's thesis. But I think I'm convinced that he raises good points, points that people like me -- who tend toward the weight-obsessed, and who like to tell ourselves that it's "about our health" -- need to read and take to heart. Some of this seeking after thinness is not necessarily healthy, and it's not necessarily virtuous.
Over the months after I reached my goal weight, it took constant vigilance to keep my weight at 108 instead of, say, 112. Is it reasonable for me to fear those four pounds? OK, the truth is I'm really afraid that if I let myself gain 4 pounds, I'll let myself gain 40. Is that a reasonable fear? All my clothes still fit at 112. If I relaxed my diet slightly and became stable at 112, would I be happier or sadder? And does it make any sense at all to be "proud" of my weight loss? Even if it's true that gluttony was a big problem before, am I better off if I replace it with vanity and pride?
I think I came away very convinced of one sentence in the book, one of the principles of the "health at every size" movement: A healthy weight is the weight a person maintains while living a healthy life. To me, that means while being physically active and eating a well-balanced diet in response to real hunger signals. Campos derides the traditional approach, but I disagree. I think traditional "diet and exercise" can help a person create that healthy life; you may have to exercise on purpose in order to get enough physical activity, and you may have to control your eating in order to balance your diet and learn to eat in response to hunger. I did. But it does suggest that the number on the scale ought to have less sway on our decisions, personal and public, and especially on our compassion towards others, than it currently does.
In a previous post I wrote about my philosophy for teaching nature study to elementary-school kids, and promised to mention the book I'm going to use next year with Oscar. Here it is: Messing Around with Baking Chemistry by Bernie Zubrowski, from the Children's Museum Activity Book series. (Little, Brown, and Co., 1981; ISBN 0-316-98878-2)
Question: What makes things fizzy?
In this experiment, you will produce different combinations of mixtures that react to form fizzy solutions. You'll start with a baking soda/vinegar mixture and then move on to produce your own safe-to-drink, though not particularly tasty, lemon soda.
Science concept: Certain materials, when brought into contact with other materials, react in a way that forms bubbles. Acids and bases often combine to form carbon dioxide, which, as a gas, is what makes carbonated soda fizzy. You'll be experimenting with several common ingredients to determine which react in this way.
04 June 2009 in Books, Engineering, Food, clothing, and/or shelter, Mathematics, Science (Chemistry), Science (General) | Permalink | Comments (2) | TrackBack (0)
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