Archive for March, 2010

Gaps between coaches and professors

March 31, 2010

Joshua Kim asks:

Have you ever taught or taken a class where the instructor acted more like a coach than a lecturer and grader? How do you explain the gap between coaches and professors?

A very thought provoking question! And, the entire post (a very short one at that) is worthwhile too!

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Mathematisation of …

March 30, 2010

Sexual attraction; here is the abstract:

Pollen tubes follow attractants secreted by the ovules. In a recent paper in BMC Plant Biology, Stewman and colleagues have quantified the parameters of this attraction and used them to calibrate a mathematical model that reproduces the process and enables predictions on the nature of the female attractant and the mechanisms of the male response.

Here is the last paragraph of the piece:

As with many other mathematical approaches to complex biological behavior, this new model from Stewman et al. [3] raises more questions than answers. But the fact that new approaches are contributing to a precise experimental description of the system [2,11,12] may make mathematical modeling an important tool for testing and selecting candidate molecules that may fit the in vivo biological profile of the final step of plant sexual attraction.

Here are the references in question:

[2] Dresselhaus T, Márton ML: Micropylar pollen tube guidance and burst: adapted from defense mechanisms? Curr Opin Plant Biol 2009, 12:773-780.

[3] Stewman SF, Jones-Rhoades M, Bhimalapuram P, Tchernookov M, Preuss D, Dinner AR: Mechanistic insights from a quantitative analysis of pollen tube guidance.

BMC Plant Biol 2010, 10:32.

[11] Márton M, Dresselhaus T: A comparison of early molecular fertilization mechanisms in animals and flowering plants. Sex Plant Reprod 2008, 21:37-52.

[12] Okuda S, Tsutsui H, Shiina K, Sprunck S, Takeuchi H, Yui R, Kasahara RD, Hamamura Y, Mizukami A, Susaki D, Kawano N, Sakakibara T, Namiki S, Itoh K, Otsuka K, Matsuzaki M, Nozaki H, Kuroiwa T, Nakano A, Kanaoka MM, Dresselhaus T, Sasaki N, Higashiyama T: Defensin-like polypeptide LUREs are pollen tube attractants secreted from synergid cells.

Nature 2009, 458:357-361.

Here is Reference 3. Have fun!

Why are there few negative reviews than positive ones

March 23, 2010

Jo Walton gives several reasons — here are two:

Lots of magazines only publish positive reviews. They don’t say “You must love everything.” It’s much more insidious. They’ll send a reviewer a pile of books and say “Here’s a pile of books. Write reviews of the ones that are worth it, get them to us by Friday and we’ll pay you $50 (or $100, or $25…) per review.” The corrolary is that they pay nothing for the ones you don’t review because they’re not worth it. The reviewer is then in the unenviable position of having a pile of books they have to spend time reading before Friday, knowing they’ll only be paid if they produce a positive review. Lots of people can find something nice to say about anything if it means the difference between being paid and not being paid, eating and not eating. I was sometimes in this position when I reviewed for the old British RPG magazine Arcane. I tried hard to be ethical and often succeeded. Only publishing positive reviews is as terrible an idea as it was when Orwell wrote against it.

Beyond that, there’s an extra layer if you are a writer reviewing—and this is why I stopped writing about everything I read. If you are a writer, there’s a way in which all the other writers are your competition. This is quite different from them being your friends. You’re competing: for awards, for review space, for attention, for sales. I don’t think it’s a zero sum game like this so that if someone buys my book they don’t buy someone else’s. But some people do. In this worldview, if I trash someone’s current book, not only am I hurting their potential sales, but they imagine I am doing it on purpose to put down a rival. The fact that this never occurred to me before someone accused me of doing it—on my livejournal ages ago, not here—is irrelevant. That was their perception. And I can only deny intentionality. I’m a midlist writer. I’m also a reader. From my point of view, I was a reader warning other readers to avoid a bad book. From that author’s point of view, I was one midlist writer putting down another midlist writer to my own potential advantage. This is so repulsive a thing to have thought about one that I’ve been extremely careful ever since.

And, there is more in Walton’s piece; take a look.

Link via Jenny.

A paradigm for research domains that combine models and mathematics

March 23, 2010

During the opening lecture of the 16th IFAC World Congress in Prague on July 4, 2005, Rudy Kalman articulated a principle that resonated very well with me. He put forward the following paradigm for research domains that combine models and mathematics:
1) Get the physics right.
2) The rest is mathematics.

From this piece of Jen C Willems (pdf); link via John Baez.

Difficilior lectio potior

March 22, 2010

Classical scholars have, I believe, a general principle, difficilior lectio potior–the more difficult reading is to be preferred–in textual criticism. If the Archbishop of Canterburry tells one man that he believes in God, and another that he does not, then it is probably the second assertion which is true, since otherwise it is very difficult to understand why he should have made it, while there are many excellent reasons for his making the first whether it be true or false.

G H Hardy, The Indian Mathematician Ramanujan, American mathematical monthly, Vol. 44, 137-155, 1937.

On being creative as a theorist

March 22, 2010

Thus, the theorist is required to abandon tried and true procedures and to exercise taste and judgment; he is driven out of his comfortable, well-trodden ways, and is forced to be creative, a skill that is neither taught in courses nor rewarded very reliably by the National Science Foundation and other funding agencies.

P W Anderson — here.

Seat preferences in aircrafts

March 22, 2010

Can be influenced by so many strange things; here is Dermot O’Brien:

I think I shall always sit in seat 31C.

A must-read piece!

Physics education research

March 19, 2010

I just found that Phys. Rev. family has a journal for education (Thanks to ZapperZ). Some of the papers there seem to be very interesting too — like this one for example:

We report a detailed study of the implementation of Tutorials in Introductory Physics at a large-scale research institution. Based on two successive semesters of evaluation, we observe students’ improved conceptual mastery (force and motion concept evaluation median normalized gain 0.77, N=336), albeit with some student discontent. We replicate the results of original studies of tutorial effectiveness and document how and why these results occur. Additionally, using the Colorado Learning Attitudes about Science Survey we measure the support of students’ expertlike beliefs about learning physics in our environment. We examine this implementation from a viewpoint that emphasizes varying contextual levels of this implementation, from students’ engagement in individual tasks, to the situations in which these tasks are embedded, to the broader classroom, departmental, and educational structures. We document both obvious and subtle features that help ensure the successful implementation of these reforms.

One of the key things that I found in the paper is the report that as there are students who enjoy these sessions, and, there are also students who would rather not do tutorials. It would be worthwhile to study the group that does not enjoy the tutorials and figure out ways of catering to their needs!

Surprises from a book of oracles

March 19, 2010

… it gives us a rare glimpse – as Jerry Toner stresses in Popular Culture in Ancient Rome – into the day-to-day anxieties of the ordinary inhabitants of the Roman Empire. For (never mind the publicity yarn about Alexander the Great) this is not elite literature, or certainly not literature aimed exclusively at the elite; in fact, the question about “being sold” implies that slaves were among the intended clientele. Here we have a long list of the kinds of problems that made ordinary Roman men (and they do seem to be exclusively male questions) anxious enough to resort to fortune-tellers. Some of these are the perennial issues of sex, illness and success (“Will I split up from my girlfriend?” “Will the one who is sick survive?” “Will I be prosperous?”). But other questions reflect much more specifically Graeco-Roman concerns about life’s fortunes and misfortunes. Alongside worries about the wife’s pregnancy, we find questions about whether or not to rear the expected offspring: a vivid reminder that infanticide was one orthodox method of family planning in the ancient world, as well as being a convenient way of disposing of those who emerged from the womb weak, sickly or deformed. Debt and inheritance also bulk large among the topics of concern, accounting for at least twelve of the ninety-two questions (“Will I pay back what I owe?” “Will I inherit from a friend?”). So do the dangers of travel (“Will I sail safely?”) and the potential menace of the legal system (“Am I safe from prosecution?” “Will I be safe if informed against?”). Even illness may be thought to be the result of crime or malevolence, as the question “Have I been poisoned?” shows.

Toner is excellent at squeezing the social and cultural implications out of this material. As well as reflecting on the perilous, debtridden, short and painful human lives that the oracle book reveals, he notes some surprising absences. There is nothing here (poisoning apart) to suggest a fear of violent crime, despite the fact that we often imagine that the Roman Empire was full of highwaymen, pirates and muggers. Nor is there anything on the institution of patronage. Modern historians have written volumes on the dependence of the poor on their elite patrons – for everything from jobs, to loans or food. Toner speculates that the intended users of these oracles were so far down the Roman social hierarchy that they were below the reach of the patronage system (which only extended so far as “the respectable poor”). Maybe. Or maybe the whole system of patronage was far less important in the life of the non-elite, than the Roman elite writers, on whom we mostly rely, liked to imagine. Or, at least, maybe it was far less important in whatever corner of the Roman Empire this strange little book originated.

Pushing the evidence a little further, Toner suggests that we might see in these oracles a rudimentary system of risk-assessment.

From this must-read review by Mary Beard at TLS; link via Jenny.

Open review!

March 18, 2010

I feel all reviews — favourable and unfavourable — given to a paper should be available online — the only thing that I agree should be redacted (if the reviewers feel so) is the name and affiliations of the reviewers. For rejected papers, the authors should be given the option to upload the reviews online — in their pages — provided they are willing to also upload their paper — without any modifications after the review. When such a open review process is implemented, along with double blind reviews, many of the ills that afflict the current peer reviewing culture will be drastically reduced. In any case, with that being my opinion on peer reviewing, I am very glad to see this post of Coturnix (via Dr. Free-Ride).