Space bacteria

Bacteria (Salmonella typhimurium) flown in space on the shuttle were shown to be more virulent than the control strains held on Earth.

What I found pretty neat was something that one of the researchers said: "Wherever humans go, microbes go; you can't sterilise humans. Wherever we go, under the oceans or orbiting the Earth, the microbes go with us, and it's important that we understand... how they're going to change."

This is a good reminder that microbes, the prokaryotes but also the protists, play extremely important ecological roles in the environment and within other organisms, that we frequently overlook because of their small size. Concepts which seem 'exotic', such as parasitism, 'alternative' metabolisms, and even perhaps the ecology of soil bacteria, are actually more commonplace than we think.

In terms of sheer number and biomass, the microbes are the rule, not the exception, and they're everywhere. Even in space flight, the pinnacle of human technological achievement, we've still not figured out how to deal with the 'problem' of microbial hitch-hikers.

Perhaps we shouldn't think of them as problems to be eliminated. After all, they've been with us since the beginning and have had a hand in our own evolution (for example vitamins produced by gut bacteria which our own metabolisms cannot produce). They've pretty much become part of us, and attempting to eliminate them would be a sign of hubris and only put our own selves in the way of illness.

PNAS article link.

Slime Mould

A 15kg lump of slime mould found in Jiangsu province, dug up from 10m underground. Called "太岁"(Tai Sui) by the Chinese, Slime mould has been found from all over China, from Inner Mongolia to Gansu or Guangdong in the South.
The strange life form, neither animal or vegetable has confounded the Chinese over the millenium and they had recorded information about slime mould in ancient Chinese medical texts.

Advice for alpha-female Hilary Clinton

Frans de Waal, primate ethologist and author of “Our Inner Ape” (2006) decides to weigh in with some recommendations for Hilary Clinton in "Alpha Females I Have Known" (The Huffington Post, 06 Sep 2007). Its based on primate behaviour which may just be what it takes to unravel politics in Washington.

His sugggestions:

1. It'll only get better with age. So far, the typical alpha female is post-reproductive, e.g. Golda Meir, Indira Gandhi, Margaret Thatcher, Angela Merkel. Younger females will distract the process by arousing competition among males.

2. Since males respect power more than age and personality, lead a large coalition by promoting female solidarity. So the earlier point, being sexually non-threatening helps, and be a champion of female causes.

3. Dismiss any inclination to be extremely loyal to friends; reach out beyond the inner circle to build bridges and even groom rivals. Impartiality is tough but sorely needed since the men don't get it (a reference to Bush).

4. Don't listen to clueless designers - don;t emphasise attractiveness or femininity - that's a hat tip to sexual power which won't build a broad coalition (again point 1). Since you have high status, the men are turned off anyway.

Read "Alpha Females I Have Known."

Technorati Tags: behaviour

Counteracting [phosphorus-induced] phytoplankton blooms with filter-feeding fish

Yang, S.L., 1982. Fish culture and reservoir management in the Republic of Singapore. In: Soewardi, K.Mahar, C. (eds.), Proceedings of the Seminar on Production and Exploitation of Open waters (with special emphasis on reservoirs), Bogor, 15-17 June, 1982. SEAMEO-BIOTROP, Bogor (Indonesia), 1987. Biotrop Special Publication (Indonesia) (ISSN 0125-975X), No. 27. Pp. 89-101.

Abstract - The primary function of impounding reservoirs in the Republic of Singapore is the collection and storage of rain water for the nation's water supply. The quality of reservoir water is a prime concern and the Public Utilities Board of the Republic has a responsibility to ensure that any activity in these reservoirs does not lead to deterioration of water supply. The objective of fish culture and reservoir management, apart from protection, is therefore to improve the quality of the raw water in these reservoirs.

A Biology Unit was established toward the end of 1970 to undertake these biological activities. The project on fish culture in reservoirs was initiated in 1972 at Seletar Reservoir. The feasibility of rearing the bighead carp (Aristichthys nobilis) in floating net-cages without supplemental feed was studied and the growth rates of the carp at different stocking rates were compared.

The stocking rate of 300 carp per net-cage of 6 m (length) x 4 m (width) x 5 m (depth) was found to have an optimum yield of about 680 kilograms at Seletar Reservoir. At this stocking rate, the carp attained an average weight of 2.0-3.0 kilograms during a grouping period of 12 months. A pilot project of 48 net-cages introduced at Seletar Reservoir in 1973 resulted in a harvest of 20.000 kilograms of carp in 1974. The project was then expanded at Seletar Reservoir and extended to other reservoirs. By the end of 1981, a total of 342 net-cages were operated in 4 reservoirs with a total harvest of 88.000 kilograms of carp.

The bighead carp which feeds solely on planktonic organisms in the reservoirs acts as a natural biological filter and thus helps to remove the excessive nutrients in the reservoirs. The carps, after growing big, are sold. Proceeds from the sales help to defray the cost of operating the Biology Unit.

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I thought this was a pretty neat exercise. We used to gaze out to cages in Kranji Reservoir and hear about it and later tell students, so its nice to see this abstract; the NUS Science Library is digging this up and there might be a couple more papers that I hope to get. Now that I'm using it in class, I'd like to cite a paper, since its possible, rather then my memory!

It was not the only measure exercised to reduce eutrophication in our reservoirs, of course. Besides relocation of farms near rivers, the government even discouraged phosphorus-rich residential soap water runoff into drains as that eventually led to the catchment water. So I remember them removing backyard tap heads in the 1970's! The backyards of residential area were where pre-washing machine clothes were laundered, and the spent soap water was poured into drains. By removing the tap heads in backyards, families redesigned their backyard areas. From then on, waste soap water was directed into the sewage system instead.

Nowadays you can find biodegradable, phosphorus-free soap powder for sale.

Links

• "Historical perspective of the phosphate detergent conflict," by Chris Knud-Hansen.
  Working Paper 94-54, February 1994.
• "Shoreline Stewardship for Landowners." NSLandsCo.com. Has a nice illustration.
• "Province's dish-soap step too timid, critics charge," by Mary Agnes Welch. Winnnipeg Free Press, 05 Sep 2007.
• FAO: Cultured Aquatic Species Information Programme: Aristichthys nobilis

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