Tuesday, August 30, 2011

A New Way of Understanding What Might Kill Us

It has been more than half a century since the discovery of penicillin revolutionized our ability to control communicable disease. Since that time a lot of progress has been made on all kinds of diseases, although the emphasis has been more on degenerative diseases--treatments for cardiovascular conditions, cancer, and other issues that are associated especially with an aging population. But, a story in today's New York Times puts the control of bacteria and viruses back in the spotlight. The story focuses on the work of Dr. James M. Musser, chairman of pathology and genomic medicine at the Methodist Hospital System in Houston.
It is the start of a new age in microbiology, Dr. Musser and others say. And the sort of molecular epidemiology he and his colleagues wanted to do is only a small part of it. New methods of quickly sequencing entire microbial genomes are revolutionizing the field.
The first bacterial genome was sequenced in 1995 — a triumph at the time, requiring 13 months of work. Today researchers can sequence the DNA that constitutes a micro-organism’s genome in a few days or even, with the latest equipment, a day. (Analyzing it takes a bit longer, though.) They can simultaneously get sequences of all the microbes on a tooth or in saliva or in a sample of sewage. And the cost has dropped to about $1,000 per genome, from more than $1 million.

Monday, August 29, 2011

Federal Judge Blocks Alabama Immigration Law--For the Moment

A Federal District Judge in Alabama has temporarily blocked the implementation of the new anti-immigrant legislation that was scheduled to take effect this week in Alabama. She blocked it only to give herself more time to study the law, so both sides apparently took comfort in that fact:


The ruling was cheered both by Republican leaders who were pleased the judge didn't gut the law and by opponents who compare it to old Jim Crow-era statutes against racial integration.
Blackburn didn't address whether the law is constitutional, and she could still let all or parts of the law take effect later. Instead, she said she needed more time to consider lawsuits filed by the Justice Department, private groups and individuals that claim the state is overstepping its bounds.
The judge said she will issue a longer ruling by Sept. 28, and her temporary order will remain in effect until the day after. She heard arguments from the Justice Department and others during a daylong hearing last week.

Sunday, August 28, 2011

Urbanization is a Major Source of Environmental Degradation

An important new study has just been published in the academic journal PLoS One summarizing our knowledge of what growing urban populations mean for the environment. The authors--Karen Seto, Michail Fragkias, Burag Guneralp, and Michael Reilly--drew the following major conclusions:
The conversion of Earth's land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It drives the loss of farmland, affects local climate, fragments habitats, and threatens biodiversity. Here we present a meta-analysis of 326 studies that have used remotely sensed images to map urban land conversion. We report a worldwide observed increase in urban land area of 58,000 km2 from 1970 to 2000. India, China, and Africa have experienced the highest rates of urban land expansion, and the largest change in total urban extent has occurred in North America. Across all regions and for all three decades, urban land expansion rates are higher than or equal to urban population growth rates, suggesting that urban growth is becoming more expansive than compact.