GMO corn: a scientific study

A recent study from France (paper is here but not free) showed that genetically-modified corn negatively affected the health of rats. The press is reporting on this in a variety of ways, and I think there is a lot of bad information in the articles I am seeing. Science is messy, so it is impossible to have a straightforward take-away (like "GMO's are bad") from this study. I'll try to clarify what I can...

1. What is this GMO corn? Why does it exist?

   This corn is a genetically modified organism (GMO) that was made in a laboratory to be immune from Roundup, a weed control chemical. If a farmer plants a field with this corn the entire field can be sprayed with Roundup to control weeds. Normal corn would be hurt by Roundup.

2. What experiment was done?

   Scientists in France fed rats different food for 2 years. The different groups were:

   • Normal water and non-GMO corn (not treated with Roundup)
   • Normal water and a mix of normal and GMO corn in 3 different fractions (not treated with Roundup)
   • Normal water and a mix of normal and GMO corn in 3 different fractions (Treated with Roundup)
   • Water with different levels of Roundup in it and non-GMO corn (not treated with Roundup)
   This means that the researchers should be able to see if the presence of Roundup is having an effect and separately they should be able to see if the GMO corn alone has an effect.

   The researchers took blood samples from the rats periodically to study their health and studied the rats' organs after the rats died.

3. Did the GMO corn have an effect?

This is where science is hard. The answer isn't a clear yes or no - it has lots of caveats and statistics. Female rats died earlier from GMO corn (with or without Roundup) and earlier from Roundup alone. Male rats don't show as strong of an effect. Tumors usually developed earlier in female rats, especially when drinking roundup directly.

But not all of the data make sense. For instance, blood chemicals were used to look for evidence of kidney failure. The results look bad for GMO corn only and Roundup only, but the GMO corn with roundup doesn't show a measurable effect.

Bottom Line: The data presented in the paper cannot exclude a hypothesis that Roundup and GMO corn does not affect the health female rats.

What about the criticisms and responses? Many of the responses particularly frustrated me:

1. Each group was only 10 rats. That isn't big enough to see anything!

Biology is really hard, and it is super expensive to take care of and monitor 200 rats for 2 years. This is a HUGE study compared to what I see in pre-clinical cancer research. This study could be used to get funding for a much bigger study, but studies don't get much bigger than this.

2. These were a special type of rat that gets cancer easily. Of course they got cancer!

These are the epitome of white lab rats. It made perfect sense to use these.

3. The health problems didn't increase with increasing dose. So this is just random variation, not causality.

It could be a threshold effect - there is a dose window where it increases, but above that there is no change. This is relatively common and makes sense - after all, taking 10 times a normal dose of medicine won't make you 10 times better...

4. Other studies have shown that GMO's are safe

This is true. But, this study has gone longer and looked at more variables than some other studies have. Additionally, you should ask how many of the "other studies" were funded by Monsanto or other groups that want to show GMO's are safe. I'm not saying the other studies are all bad, but each study needs to be evaluated individually rather than counting the number results that say "effect" versus "no effect".

Apparently the French Prime Minister has released a statement saying "I have demanded a fast procedure, about a few weeks, to verify the scientific value of the study". Unfortunately, the best way to verify scientific value is to repeat the study. That will take more than 2 years! It is possible for other scientists to review the data from the study. Also, further statistical analysis could be done on the data.

These types of GMO crops are relatively new and it is possible there could be health effects we don't yet understand. This study shouldn't cause you to panic and not eat corn, but more study is warranted.

Teaching Lesson: Getting Students to Talk

There are many challenging situations as an instructor - some of which I have already encountered - and learning to correctly and competently address them will improve my teaching. One that I have encountered is quiet students. Typically physics isn't a very discussion-oriented class, but we do a lot of small group work. There are bright students who don't seem to fully join the group. Their silence leads to the group excluding them.

I tried to address this problem with minimal success. I'm sure I will have many more chances to try different solutions. I read a very interesting piece in the Chronicle of Higher Education (subscription required) about getting quiet students to talk. The author had a been a silent student due to her Appalachian upbringing and tried to find a way to get bright, quiet students to speak up in class.

Here is a excerpt from the article

"Is the problem," I asked, "that you don't know where your comments will fall on a scale of one to smart?" She nodded. "Let's fake it," I suggested, and, for the first time, she looked mildly hopeful. I e-mailed her a few questions before the next class discussion and told her to try out an answer on me before the class met. She duly, if tentatively, offered her electronic answer, and I responded with (justified) reassurance.

The scheme worked. She turned bright pink when I asked the question, but she put up her hand, and I called on her. She was barely audible, but she delivered her answer, to which I was able to say honestly, "Right. Great response, and here's why it's important." I e-mailed her that evening to say how pleased I was, and how proud of her—and that we would do it again next week. We did.

The week after that, she stuck up her hand without prompting and delivered one of the smarter student comments of the whole term. She was thrilled. Again I wrote to reassure her, and in several of the remaining classes she had something to say. This technique has worked for a number of nonspeaking students since then, mostly female but occasionally male as well.

(Source Talk to Me by Ashley Marshall) I look forward to trying something similar to this in my classroom in the future.

Crazy Medical Science: Dragon Blood!

I am subscribed to a fairly large number of RSS feeds for journals. This means I get to scan many article titles and abstracts. Some of the journals I am subscribed to are medical journals - their articles tend to report on clinical trials and drugs I have never heard of. They are not particularly useful to me.

One of the journals that seems most relevant to me is the Journal of the Radiation Research Society. There are many articles in the journal that are closely related to what I am working on, or what I hope to someday be working on.

Today an article caught my eye, but not because I thought it would be relevant to me. "Dragon's Blood May Have Radioprotective Effects in Radiation-Induced Rat Brain Injury" (subscription required). What? The cure for cancer is dragon's blood? Obviously I should get my sword ready and go on a quest!

The first sentence of the abstract explains what Dragon's Blood is. I was a bit disappointed:

Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis. It is a traditional medicinal that is used for wound healing and to stop bleeding.

I suppose that I can believe that Dracaena cochinchinensis is the Latin name for a dragon. I refuse to look it up and be disappointed...

Are you out there news media? You've recently given me headlines about the zombie apocalypse. Now I demand headlines about Dragon's blood curing cancer!

Professor vs Doctor

When I was an undergraduate I worked with someone who wasn't technically a "professor", but who had a permanent position. It caused me great anxiety - I had no idea what to call him. As a young undergraduate, I didn't feel ready to call a faculty-type by the first name. I think I went with Dr. Lastname.

I've been surprised to hear undergraduates refer to faculty as Dr. Lastname. I realized that in my mind, Prof > Dr. I hadn't understood why undergraduates would only use the PhD title, and not the Professor title - in my mind, postdocs are Dr. Lastname.

Recently I realized that my viewpoint is skewed from (1) physics and (2) not attending college with many adjunct faculty. At places where some faculty-types only have a master's degree, Dr > Prof. As an undergraduate I did have some classes (in humanities) that were taught by "lecturers", rather than faculty. I didn't understand the distinction and called them Prof anyways. But in physics, all faculty (at MIT) had PhD's and I knew plenty of people with PhD's who weren't faculty.

Now I know better. Right now, I could be adjuncting as a "professor" at a local college. The set of "people with PhD's" does not fully enclose the set of "people who are faculty" so it is problematic to say/assume "prof > dr". It truly boils down to institutional culture: some places most undergrads use Prof, other places Dr is normal, and some are even comfortable with first-names. I'm glad I learned this before I was faculty and become highly offended of an undergraduate calling me Dr. Ackerman (-:

Publication Goal #2

After my paper was accepted I knew I still hadn't cleared the "real" scientist bar... the paper needed to actually be cited. I hope that I someday have enough papers/citations to not know/worry/care when they get cited; but right now I only have one paper. So I am going to know how many times it has been cited.

And it has been cited once! This is the bar I wanted to clear. Shortly after my paper came out, another paper was published in a "better" journal (by some standards) that had some similar results. I was somewhat nervous that the other paper would be cited and that my paper would disappear into obscurity. Now that my paper has been cited in a review paper, I can be optimistic that it might be cited in future papers - when the appropriate results are being discussed.

Citations are - in a way - proof that one has contributed to the overall progress of science. Or, that is how I choose to think about them. It is not that every important paper has many citations or that every paper that has many citations is important. But if I want my work to matter - to be medically or otherwise relevant - the only way to know it is happening is through evidence that other researchers are reading and using it. That is what citations are (in my naive mind).

Secret Skill Training at Stanford

I remember all of the things I was "forced" to do in high school because they were good for me: create outlines, write multiple drafts of papers, wear a helmet. High school me (and her friends) thought most of that stuff is lame - I'm so smart/talented/safe I shouldn't have to do any of it.

Frustratingly, all of that training was useful. It would have been more useful had I taken it more seriously. Interestingly, much of it still exists at the graduate school level. There are these people out there (call them "faculty") who are more experienced/smarter/older than me and they are telling me (and my classmates) to do certain things that seem unnecessary. Now they explain *why* we are doing them and we are supposed to understand, but it still felt a bit like high school: the students groaning and mumbling about the stuff we were supposed to do "for our own good".

Finals Exams

I hated taking tests as a student. I would get terrible test anxiety and forget everything I knew. Sometimes new "knowledge" invaded my brain and I would end up doing all of my cross-products on an electromagnetism test wrong. Fine. At a certain point, I accepted it. I needed to do well on the homework and study - but I wasn't going to get an amazing test score. It isn't so bad when you accept it.

Now I know there is something worse - giving an exam to students. In a class of 40, I can identify/name about 30 of the students. Close to 15 have consistently come to my section. I told them on the first day of section - my goal was for them all to get an A on the exam.

I tried to find great activities for section. I posted notes and clarifications and alternative solutions. I wrote a practice exam for the final and wrote 15 pages of solutions - explaining the approach, as well as ways to get partial credit. I prepared a 2 hour review session where I focused on conceptual material, with 8 clicker questions and some other example problems.

And then I saw the final exam.