Monthly Archives: April 2009

Swine flu: a purebred after all?

Contrary to initial reports, some experts think that swine flu may be purely of swine origins. Thanks to revere for the pointer.


Tenure is as tenure does, part 2

Blogger excimer at Carbon-Based Curiosities had some things to say after he read Columbia religion professor Mark C. Taylor’s recent piece in the New York Times. Taylor’s op-ed, like Francis Fukuyama’s before it, call for the abolition of tenure.

I’ve written before that abolition seems a bit heavy-handed to me. Unlike Fukuyama, Taylor proposes an explicit policy to put in tenure’s place:

Impose mandatory retirement and abolish tenure. […] Tenure should be replaced with seven-year contracts, which, like the programs in which faculty teach, can be terminated or renewed. This policy would enable colleges and universities to reward researchers, scholars and teachers who continue to evolve and remain productive while also making room for young people with new ideas and skills.

My instinct is that Taylor’s proposed changes could well have the effect he says: universities could turn over their faculties faster and reward the effective sooner and more often as a result.

However, I fear that seven-year contract system Taylor advocates might insufficiently protect academic freedom. And academic freedom is (supposedly) the whole reason tenure exists in the first place. Sometimes people question the need for science and engineering faculty to have academic freedom (see discussion here, for example). The argument is usually that nothing a scientist or engineer says could be so politically controversial as to incite calls for their dismissal. But that is short-sighted. Academic freedom also means being able to assign a poor student the grade he deserves, without having to worry about whether the student’s father is a major donor to the university. Academic freedom might mean being able to pare down the number of funded grants a professor has for a short time, maybe to spend a year focusing on service work, or to focus on seeking funding in a totally new research area. Academic freedom might mean insisting on researching “unfundable” research areas with little or no funding, all the while being sure that eventually your results will speak for themselves and that everyone else’s view will come around.

So I am not convinced that a 7-year contract would be the best replacement for today’s tenure system. But nonetheless, I am happy to see Taylor’s op-ed, unlike Fukuyama’s, understand that the problem is not tenure per se, but the link between tenure, retirement, and hiring policies.

But, of course, since I am in the hunt for a tenure-track academic position myself, I suppose I might be biased.

Happy days!

I usually need some extra encouragement to get moving on Monday. These two TED videos, from Steven Pinker in 2007, and from Alex Tabarrok in 2009, did the trick for me. Happy days!

A non-metallic catalyst for CO2 reduction

Last week I saw a neat paper from Siti Nurhanna Riduan and her co-workers at Singapore’s Institute of Bioengineering and Nanotechnology. Ms. Riduan managed to reduce CO2 to a silylmethoxide (and, after aqueous work-up, methanol), at room temperature and moderate pressures, with an inexpensive, non-metallic catalyst. The catalyst was a carbene, meaning an organic molecule containing a carbon atom with two nonbonding electrons. The reducing agent was a hydrosilane. This relatively exotic critter provides hydrogen equivalents in a solvent-miscible, liquid form.

The reaction even worked using dry air as the source of carbon dioxide! The carbene catalyst is way cheaper than exotic metals like ruthenium usually used for this reaction, which bodes well for future applications of this reaction. To be viable at really large scales, the reaction must be adapted to a different reducing agent, or else someone will have to engineer and demonstrate an effective, energy-efficient cycle for regenerating the hydrosilane.

Blood Falls

Jill Mikucki’s work on the geobiology of Blood Falls was published in Science last week, and since then, her article has received attention from the lay press as well. And rightly so, I think, because her work is fascinating stuff. A bacterial community thrives in a salty, iron-rich, anaerobic, ice-cold subglacial lake that is apparently completely isolated from Earth’s atmosphere! Waters in the lake do occasionally reach the surface through poorly understood subglacial fluid flows, and when they do, the iron-rich waters rapidly oxidize on exposure to air, forming blood-red mineral deposits. This outflow thus provides at least two things to this ecosystem: a cool name — Blood Falls — as well as a means for Mikucki to sample the otherwise inaccessible, isolated subglacial waters.

I am no chemical oceanographer, but if I understand her paper correctly, she and her co-workers are saying that the sulfate in the subglacial lake catalytically mediates the microbial reduction of triply-charged iron ions to doubly-charged iron ions.  Mikucki and her co-workers think that the sulfate is reduced to sulfite or other intermediate-oxidation-state sulfur compounds, after which it gets re-oxidized back to sulfate, by transferring its newly acquired electrons to triply charged iron.  This recycle keeps sulfate levels in the ecosystem constant, and its a very new idea; usually in anaerobic ecosystems, sulfate reduction goes all the way to hydrogen sulfide; sulfate is not regenerated.

The take-away is not just that life exists down there underneath the glaciers.  The discovery of an extant, non-sulfidic, iron-rich microbial ecosystem based on sulfate cycling lends support to the idea that such conditions may have prevailed during Earth’s past, especially during proposed (and still controversial) Snowball Earth scenarios.

The big remaining question is, what’s the electron donor to the ecosystem?  Mikucki’s earlier articles on the Blood Falls site contain some possible clues. First, the most prevalent microbes at the site are very closely related to Thiomicrospira arctica, a known CO2-eating “autotroph”. So it is likely that not all of the reducing power feeding this ecosystem is in the form of organic carbon. Dissolved organic carbon would be eventually be depleted anyway, if, as is believed, no new sources of DOC have ever fed in fresh carbon to the subglacial lake. Reduced sulfur compounds might be electron donors, but sulfides seemed impossible to detect in the Blood Falls waters. Karsten Pedersen and others have proposed that hydrogen gas drives a microbial ecosystem in the pore waters of hot subterranean granitic rocks. Perhaps hydrogen may turn out to be important in cold subglacial lakes too.

Molecule of note

20090423-dicyanoacetylene It’s a liquid at ambient conditions, it’s an organic compound without any hydrogens, it can cycloadd itself to unreactive aromatic rings, and it has the hottest adiabatic flame temperature of any known material, at 5260 K. Did I mention is is found on Titan?

Baby steps

Last week’s C&EN profiled some business ventures focused on non-fuel applications for biomass.

This shift away from petroleum and toward renewable feedstocks is accelerating. The world market for biobased chemicals—excluding biofuels but including bioplastics and chemical building blocks—was $1.6 billion in 2008, according to market research firm Frost & Sullivan. As oil prices fluctuate and technology improves, increased production of these and other chemicals should boost the annual market to about $5 billion in 2015.

If industrial reliance on petroleum is to be reduced, and if usage of biomass as a feedstock is to be increased, at all, the only way that has made sense to me was to proceed by baby steps: very high-value, very small markets first, high-value, small markets next, and so on until the scales are big enough and the risks are low enough to try making fuels.