Tag Archives: nutrient

Ecological forces structure your body’s personal mix of microbes

Environmental conditions have a much stronger influence on the mix of microbes living in various parts of your body than does competition between species. Instead of excluding each other, microbes that fiercely compete for similar resources are more likely to cohabit in the same individual.

This phenomenon was discovered in a recent study of the human microbiome – the vast collection of our resident bacteria, fungi, and other tiny organisms. (more…)

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NASA Maps How Nutrients Affect Plant Productivity

PASADENA, Calif. – A new analysis led by NASA’s Jet Propulsion Laboratory, Pasadena, Calif., has estimated how much the growth of plants worldwide is limited by the amount of nutrients available in their soil. The maps produced from the research will be particularly useful in evaluating how much carbon dioxide Earth’s ecosystems may be able to soak up as greenhouse gas levels increase.

A research team led by JPL research scientist Josh Fisher used 19 years of data from NASA, National Oceanic and Atmospheric Administration and international satellites to assess the maximum possible growth of vegetation all over the world based upon available water and light conditions. The scientists then cross-compared that potential maximum with observed vegetation productivity as measured by satellites. This is the first time such an analysis has been conducted. (more…)

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Why Are Coastal Salt Marshes Falling Apart?

Too many nutrients can cause extensive loss of marshes

Salt marshes have been disintegrating and dying over the past two decades along the U.S. Eastern Seaboard and other highly developed coastlines without anyone fully understanding why.

This week in the journal Nature, scientist Linda Deegan of the Marine Biological Laboratory (MBL) in Woods Hole, Mass., and colleagues report that nutrients–such as nitrogen and phosphorus from septic and sewer systems and lawn fertilizers–can cause salt marsh loss.

“Salt marshes are a critical interface between the land and sea,” Deegan says. “They provide habitat for fish, birds and shellfish, protect coastal cities from storms and take nutrients out of the water from upland areas, which protect coastal bays from over-pollution.” (more…)

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Global Warming Refuge Discovered Near At-Risk Pacific Island Nation of Kiribati

Ocean currents may mitigate warming near handful of equatorial islands

Scientists predict ocean temperatures will rise in the equatorial Pacific by the end of the century, wreaking havoc on coral reef ecosystems.

But a new study shows that climate change could cause ocean currents to operate in a way that mitigates warming near a handful of islands right on the equator.

Those islands include some of the 33 coral atolls that form the nation of Kiribati. This low-lying country is at risk from sea-level rise caused by global warming. (more…)

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Sediment Chemicals in Coastal Rivers Overall Lower in U.S. than Worldwide Averages

Almost all the sediment-associated chemical concentrations found in 131 of the nation’s rivers that drain to the Atlantic, Pacific and Gulf Coasts are lower than worldwide averages, according to a new study by the USGS. These coastal rivers are a significant pathway for the delivery of sediment-associated chemicals to the world’s coastal zones and oceans.

“I hope that the results of this new study will remind everyone that it is not only river water that can transport chemicals and pollutants, but also the associated sediment load,” said USGS Director Marcia McNutt. “Our citizens expect high environmental quality as compared with worldwide averages, but clean water alone will not suffice if river sediments are host to toxic heavy metals and concentrated organics that can produce dead zones.” (more…)

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Moonlighting Enzyme Works Double Shift 24/7

EAST LANSING, Mich. — A team of researchers led by Michigan State University has discovered an overachieving plant enzyme that works both the day and night shifts.

The discovery, featured in the current issue of Proceedings of the National Academies of Science, shows that plants evolved a new function for this enzyme by changing merely one of its protein building blocks. (more…)

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What Bacteria Don’t Know Can Hurt Them

Many infections, even those caused by antibiotic-sensitive bacteria, resist treatment.  This paradox has vexed physicians for decades, and makes some infections impossible to cure.

A key cause of this resistance is that bacteria become starved for nutrients during infection.  Starved bacteria resist killing by nearly every type of antibiotic, even ones they have never been exposed to before. (more…)

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Solving The Mystery of An Old Drug That May Reduce Cancer Risk

In 2005, news first broke that researchers in Scotland found unexpectedly low rates of cancer among diabetics taking metformin, a drug commonly prescribed to patients with Type II diabetes. Many follow-up studies reported similar findings, some suggesting as much as a 50-per-cent reduction in risk. How could this anti-diabetic drug reduce the risk of developing cancer and what were the mechanisms involved?

In a paper published today in the journal Cancer Prevention Research, researchers from McGill University and the University of Montreal reported an unexpected finding: they learned that exposure to metformin reduces the cellular mutation rate and the accumulation of DNA damage. It is well known that such mutations are directly involved in carcinogenesis, but lowering cancer risk by inhibiting the mutation rate has never been shown to be feasible. (more…)

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