Tag Archives: mechanism

Unique sense of ‘touch’ gives a prolific bacterium its ability to infect anything

New research has found that one of the world’s most prolific bacteria manages to afflict humans, animals and even plants by way of a mechanism not before seen in any infectious microorganism — a sense of touch. This unique ability helps make the bacteria Pseudomonas aeruginosa ubiquitous, but it also might leave these antibiotic-resistant organisms vulnerable to a new form of treatment. (more…)

Read More

Hydrologists Find Mississippi River’s Buffering System for Nitrates is Overwhelmed

AUSTIN, Texas — A new method of measuring the interaction of surface water and groundwater along the length of the Mississippi River network adds fresh evidence that the network’s natural ability to chemically filter out nitrates is being overwhelmed.

The research by hydrogeologists at The University of Texas at Austin, which appears in the May 11 edition of the journal Nature Geoscience, shows for the first time that virtually every drop of water coursing through 311,000 miles (500,000 kilometers) of waterways in the Mississippi River network goes through a natural filtering process as it flows to the Gulf of Mexico. (more…)

Read More

Tiny acts of microbe justice help reveal how nature fights freeloaders

The idea of everyone in a community pitching in is so universal that even bacteria have a system to prevent the layabouts of their kind from enjoying the fruit of others’ hard work, Princeton University researchers have discovered.

Groups of the bacteria Vibrio cholerae deny loafers their unjust desserts by keeping the food generated by the community’s productive members away from V. cholerae that attempt to live on others’ leftover nutrients, the researchers report in the journal Current Biology. The researchers found that individual bacteria produce a thick coating around themselves to prevent nutrients from drifting over to the undeserving. Alternatively, the natural flow of fluids over the surface of bacterial communities can wash away excess food before the freeloaders can indulge. (more…)

Read More

First Step to Reduce Plant Need for Nitrogen Fertilizer Uncovered in Science Study

MU scientists say discovery could save farmers billions and protect the environment.

COLUMBIA, Mo. — Nitrogen fertilizer costs U.S. farmers approximately $8 billion each year, and excess fertilizer can find its way into rivers and streams, damaging the delicate water systems. Now, a discovery by a team of University of Missouri researchers could be the first step toward helping crops use less nitrogen, benefitting both farmers’ bottom lines and the environment. The journal Science published the research this month.

Gary Stacey, an investigator in the MU Bond Life Sciences Center and professor of plant sciences in the College of Agriculture, Food and Natural Resources, found that crops, such as corn, are “confused” when confronted with an invasive, but beneficial, bacteria known as rhizobia bacteria. When the bacteria interact correctly with a crop, the bacteria receive some food from the plant and, simultaneously, produce nitrogen that most plants need. In his study, Stacey found that many other crops recognize the bacteria, but do not attempt to interact closely with them. (more…)

Read More

How Neurons Get Wired

Two different versions of the same signaling protein tell a nerve cell which end is which, UA researchers have discovered. The findings could help improve therapies for spinal injuries and neurodegenerative diseases.

University of Arizona scientists have discovered an unknown mechanism that establishes polarity in developing nerve cells. Understanding how nerve cells make connections is an important step in developing cures for nerve damage resulting from spinal cord injuries or neurodegenerative diseases such as Alzheimer’s.

In a study published on Aug. 12 in the journal Proceedings of the National Academy of Sciences, UA doctoral studentSara Parker and her adviser, assistant professor of cellular and molecular medicine Sourav Ghosh, report that the decision which will be the “plus” and the “minus” end in a newborn nerve cell is made by a long and a short version of the same signaling molecule. (more…)

Read More

Berkeley Lab Confirms Thirdhand Smoke Causes DNA Damage

A study led by researchers from Lawrence Berkeley National Laboratory has found for the first time that thirdhand smoke—the noxious residue that clings to virtually all surfaces long after the secondhand smoke from a cigarette has cleared out—causes significant genetic damage in human cells.

Furthermore, the study also found that chronic exposure is worse than acute exposure, with the chemical compounds in samples exposed to chronic thirdhand smoke existing in higher concentrations and causing more DNA damage than samples exposed to acute thirdhand smoke, suggesting that the residue becomes more harmful over time. (more…)

Read More

Exercise reorganizes the brain to be more resilient to stress

Physical activity reorganizes the brain so that its response to stress is reduced and anxiety is less likely to interfere with normal brain function, according to a research team based at Princeton University.

The researchers report in the Journal of Neuroscience that when mice allowed to exercise regularly experienced a stressor — exposure to cold water — their brains exhibited a spike in the activity of neurons that shut off excitement in the ventral hippocampus, a brain region shown to regulate anxiety. (more…)

Read More

Lack of Protein Sp2 Disrupts Neuron Creation in Brain

A protein known as Sp2 is key to the proper creation of neurons from stem cells, according to researchers at North Carolina State University. Understanding how this protein works could enable scientists to “program” stem cells for regeneration, which has implications for neural therapies.

Troy Ghashghaei and Jon Horowitz, both faculty in NC State’s Department of Molecular Biomedical Sciences and researchers in the Center for Comparative Medicine and Translational Research, wanted to know more about the function of Sp2, a cell cycle regulator that helps control how cells divide. Previous research from Horowitz had shown that too much Sp2 in skin-producing stem cells resulted in tumors in experimental mice. Excessive amounts of Sp2 prevented the stem cells from creating normal cell “offspring,” or skin cells. Instead, the stem cells just kept producing more stem cells, which led to tumor formation. (more…)

Read More