This week was slightly truncated because of the Bank Holiday, and allowed some catching up in Swindon. I went to listen to the first speech by Dr Vince Cable (who has a PhD in economics and used to teach the subject at Glasgow) on the priorities for economic growth. Notwithstanding the present rather gloomy economic position, statements such as “BIS is the Ministry for science, and science is a vital public good” give one grounds for optimism.
I have blogged before about the fact that many things we learned when young (in science and elsewhere) are not in fact true (or may subsequently have been shown not to be). One such myth is that after adolescence one has a fixed number of brain cells and they are not regenerated in adulthood (indeed, alcohol was said to kill them by the thousand). While the very existence of brain tumours shows that adult CNS cells can divide, it does not tell us whether they normally do so. Happily, using methods such as bromodeoxyuridine (ChEBI) labelling and immunocytochemistry, it is now recognized that there is in fact considerable turnover (neurogenesis) in adults – see e.g. reviews by Gould, by Zhao et al., and by Imayoshi et al. This has many beneficial implications for healthy ageing.
Changes in both wealth and weight are determined by the difference between one’s income and expenditure of money or calories. Unlike Mr Micawber, for whom an excess of income over expenditure resulted in happiness, for those seeking to lose weight the opposite must be the case. Clearly one can beneficially attack both sides of the equation (eat less, exercise more), albeit we all know people who can eat as much as they like and do not put on weight. Regarding the burning of energy, I had always understood that this was mainly determined by variation in the basal (or resting) metabolic rate, with even quite severe exercise burning calories (or body mass) in comparatively small amounts. A visit to Sport, Health and Exercise Science at the University of Bath (among many other interesting projects I saw there) told me that this is essentially not the case. While there is considerable uncertainty regarding how much exercise is good for you, and even what that means, modern methods of non-invasive in vivo monitoring of energy expenditure show that sustained physical activity – whether by formal exercise or otherwise – does undoubtedly account for much of the variance in energy expenditure between individuals.
Other papers that I enjoyed reading this week included one on the identification of a genuine male pheromone (in mice), two on the role of roots in improving soil structure and on improving hydrology, and two articles on the chemical genetics of (growth inhibition of) the malaria parasite Plasmodium falciparum, with all data being made available openly. A nice piece of crowdsourcing, and rich pickings for chemoinformaticians!
- Brage S, Brage N, Franks PW, Ekelund U, Wareham NJ: Reliability and validity of the combined heart rate and movement sensor Actiheart. Eur J Clin Nutr 2005; 59:561-570
- Gamo FJ et mult al.: Thousands of chemical starting points for antimalarial lead identification. Nature 2010; 465:305-310
- Gould E: How widespread is adult neurogenesis in mammals? Nat Rev Neurosci 2007; 8:481-488
- Gregory AS, Webster CP, Watts CW, Whalley WR, Macleod CJA, Joynes A, Papadopoulos A, Haygarth PM, Binley A, Humphreys MW, Turner LB, Skøt L, Matthews GP: Soil management and grass species effects on the hydraulic properties of shrinking soils. Soil Science Society of America Journal 2010; 74:753-761
- Guiguemde WA et mult al.: Chemical genetics of Plasmodium falciparum. Nature 2010; 465:311-315
- Imayoshi I, Sakamoto M, Ohtsuka T, Kageyama R: Continuous neurogenesis in the adult brain. Dev Growth Differ 2009; 51:379-386
- Levine JA: Non-exercise activity thermogenesis. Proc Nutr Soc 2003; 62:667-679
- Macleod CJA, Binley A, Hawkins SL, Humphreys MW, Turner LB, Whalley WR, Haygarth PM: Genetically modified hydrographs: what can grass genetics do for temperate catchment hydrology? Hydrological Processes 2007; 21:2217-2221
- Thompson D, Batterham AM, Bock S, Robson C, Stokes K: Assessment of low-to-moderate intensity physical activity thermogenesis in young adults using synchronized heart rate and accelerometry with branched-equation modeling. J Nutr 2006; 136:1037-1042
- Roberts SA, Simpson DM, Armstrong SD, Davidson AJ, Robertson DH, McLean L, Beynon RJ, Hurst JL: Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male’s odour. BMC Biology 2010; Free full text
- Thompson D, Batterham AM, Markovitch D, Dixon NC, Lund AJ, Walhin JP: Confusion and conflict in assessing the physical activity status of middle-aged men. PLoS One 2009; 4:e4337. Free full text
- Zhao C, Deng W, Gage FH: Mechanisms and functional implications of adult neurogenesis. Cell 2008; 132:645-660