The Electric Microbe

Revista Time (The Best Inventions)

Bacteria have always gotten a bad rap. But we should be thankful for one especially talented microbe, Geobacter, which has tiny hairlike extensions called pili that it uses to generate electricity from mud and wastewater. Professor Derek Lovley and his team of researchers at the University of Massachusetts at Amherst have engineered a strain of Geobacter that's eight times as efficient as other strains at producing power. The next step: creating Geobacter-based fuel cells that can generate cheap, clean electricity.

http://www.time.com/time/specials/packages/article/0,28804,1934027_1934003_1933965,00.html

NATURE REVIEWS - MICROBIOLOGY

In situ to in silico and back: elucidating  the physiology and ecology of Geobacter spp. using genome-scale modelling.

Radhakrishnan Mahadevan, Bernhard Ø. Palsson and Derek R. Lovley

There is a wide diversity of unexploredmetabolismencoded in the genomes of  microorganisms that have an important environmentalrole.Genome-scalemetabolic  modelling enablesthe individualreactionsthat are encoded in annotated genomesto be organized into a coherent whole, which can then be used to predictmetabolic fluxesthat will  optimize cell function under a range of conditions. In this Review, we summarize a series of studiesin which genome-scalemetabolicmodelling ofGeobacterspp. hasresulted in an in-depth understanding oftheir centralmetabolismand ecology.Asimilariterative modelling and experimental approach could accelerate elucidation ofthe physiology and ecology of othermicroorganismsinhabiting a diversity of environments, and could guide optimization ofthe practical applications ofthese species.
Acceso a review: http://www.geobacter.org/publication-files/Nature%20Reviews%20Microbiology%202011.pdf

Metal-like microbial nanowires

Physicstoday (August 22, 2011). Protein filaments made by some bacteria may bridge the gap between solid-state electronics and biological systems.

http://www.physicstoday.org/daily_edition/physics_update/metal-like_microbial_nanowires

Using Microbes to Generate Electricity

ScienceDaily (May 23, 2011) — Using bacteria to generate energy is a significant step closer following a breakthrough discovery by scientists at the University of East Anglia (UEA).
http://www.sciencedaily.com/releases/2011/05/110523152337.htm

Fossilized Feathers

Not long ago, extinct dinosaurs were considered by most as scaly and dull. All the known fossils of primitive birds (stem avians) could easily fit on a desk and our only look at Mesozoic [250 to 65 million years ago (Ma)] feathers (except for a few isolated plumes) was Archaeopteryx, a theropod dinosaur considered by most to be the most primitive bird.


Descargar artículo completo http://ifile.it/ei8umhs

Selection for positive illusions

Everybody knows that overconfidence can be foolhardy. But a study reveals that having an overly positive self-image might  confer an evolutionary advantage if the rewards outweigh the risks


descargar artículo http://ifile.it/c9bf7iw

Growth of Cities Endangers Global Environment, According to New Analysis

ScienceDaily (Aug. 19, 2011) — The explosive growth of cities worldwide over the next two decades poses significant risks to people and the global environment, according to a meta-analysis published August 19 in PLoS ONE.

Researchers from Yale, Arizona State, Texas A&M and Stanford predict that by 2030 urban areas will expand by 590,000 square miles -- nearly the size of Mongolia -- to accommodate the needs of 1.47 billion more people living in urban areas.
Urban areas, they found, have been expanding more rapidly along coasts. "Of all the places for cities to grow, coasts are the most vulnerable. People and infrastructure are at risk to flooding, tsunamis, hurricanes and other environmental disasters," said Seto.

"It is likely that these cities are going to be developed in places that are the most biologically diverse," said Karen Seto, the study's lead author and associate professor in the urban environment at the Yale School of Forestry & Environmental Studies. "They're going to be growing and expanding into forests, biological hotspots, savannas, coastlines -- sensitive and vulnerable places."

The study provides the first estimate of how fast urban areas globally are growing and how fast they may grow in the future. "We know a lot about global patterns of urban population growth, but we know significantly less about how urban areas are changing," she said. "Changes in land cover associated with urbanization drive many environmental changes, from habitat loss and agricultural land conversion to changes in local and regional climate."

The researchers examined peer-reviewed studies that used satellite data to map urban growth and found that from 1970 to 2000 the world's urban footprint had grown by at least 22,400 square miles -- half the size of Ohio.

"This number is enormous, but, in actuality, urban land expansion has been far greater than what our analysis shows because we only looked at published studies that used satellite data," said Seto. "We found that 48 of the most populated urban areas have been studied using satellite data, with findings in peer-reviewed journals. This means that we're not tracking the physical expansion of more than half of the world's largest cities."

Half of urban land expansion in China is driven by a rising middle class, whereas the size of cities in India and Africa is driven primarily by population growth. "Rising incomes translate into rising demand for bigger homes and more land for urban development, which has big implications for biodiversity conservation, loss of carbon sinks and energy use.

http://www.sciencedaily.com/releases/2011/08/110819155428.htm