The end of Drosophila as a model organism?

Looks like the days of Drosophila melanogaster as a model organism are numbered. It’s likely to be displaced by Sophophora melanogaster. Want to know why? Check out Catalogue of Organisms.

(Looks like the genus Drosophila is paraphyletic, which means that it has to be split…and D. melanogaster ends up on the wrong side of the tracks, so to speak).

H/T Sandwalk.

Insecticidal compounds in plants

Several members of three plants families – the Rubiaceae, Violaceae and Cucurbitaceae- produce cyclotides, cyclic mini-peptides made up of 28-37 amino acids arranged in a circular configuration. These compounds are very stable and have attracted the attention of pharmaceutical companies. Because these peptides lack free amino and carboxyl ends, they cannot be broken down by proteases. The compounds appear to act primarily as insecticides. In an article published in the January 29 issue of PNAS, Barbara Barbeta and colleagues investigated the role of these compounds on the larvae of lepidopterans (butterflies and moths). The compounds damaged the cells of the midgut of Helicoverpa armigera larvae, which severely stunted their growth (image from Wikipedia; see license details).

Barbeta, B.L., Marshall, A.T., Gillon, A.D., Craik, D.J., and Anderson, M.A. 2008. Plant cyclotides disrupt epithelial cells in the midgut of lepidopteran larvae. Proceedings of the National Academy of Sciences USA 105(4):1221-1225 DOI:10.1073/pnas.0710338104

Why big ideas matter – Rosenau on Obama

I’m not one to trust “my gut” without stopping to wonder why I react the way I do.  My reaction to Obama’s victory speech in Iowa was pure gut feeling, pure emotion.  Without figuring out whether I was right or wrong to feel that way, I had to ask myself why I found him so inspiring.  “Idealism” is the easy answer – after all this time, I’m still a dreamy idealist.  But there was more to it than that – there’s a sense of intellectual depth that I am drawn to.  It’s nice to see those “senses” and “feelings” substantiated with opinions based on the analysis of data.

Josh Rosenau talks about his meeting with Obama in 2006 and his thoughts about him since then.  It’s definitely worth reading.

Orac on CAM

Since it isn’t medicine, and “Quackademic medicine” is too snarky, what should we call alternative therapies? It’s definitely a must-read.

Orac:Reclaiming the linguistic high ground: Renaming “complementary and alternative” medicine and the power of language

Skipping Bill

Bill Clinton is speaking on campus today.  I’ve been thinking about whether I want to go and see him or not, but I think I have finally decided not to go.  While he has never been my favourite politician (I think he wasted too many opportunities when he was in office), I love to hear him speak.  But right now, I’m annoyed with the stuff he has said on the campaign trail.  So while I’d love the chance to hear Clinton speak again, I don’t think I’m going to go.

Edwards dropping out

The AP is reporting that John Edwards is dropping out of the Democratic presidential primary race.  It’s a shame, I really like Edwards, but his campaign was going nowhere fast.  So does he endorse one or the other, or does he try to keep his options open by not picking a side?

Source: dKos

Do red leaves photosynthesise?

In Temperate regions, two distinct processes are involved when leaves change colour in the Fall. Yellow and orange colours reflect carotenoid pigments that are already present in the leaves. Reds reflect something different – anthocyanins that are produced as part of the process of senescence.

The red colours produced by pointsettias represent something different. In this case, leaves change colour in order to advertise the (relatively inconspicuous) flowers to pollinators. Pomar and Ros Barceló asked the question of whether these leaves are photosynthetically active – after all, that’s a lot of leaf area to sacrifice just for reproduction. Their findings?

Both red and green poinsettia leaves are able to use photons efficiently to perform photosynthesis in the range of irradiances common on the Earth’s surface.

At lower light levels green leaves are better at photosynthesis than red ones, but at the level of sunlight you’d expect to see on a sunny day, the differences were very small. However, red leaves aren’t very good at dissipating excess energy. However, they compensate for this by having the red anthocyanins which absorb some of the incoming radiation.

Pomar, F., Ros Barceló, A. (2007). Are red leaves photosynthetically active?. Biologia Plantarum, 51(4), 799-800. DOI: 10.1007/s10535-007-0164-z