March 12, 2008, 9:38 PM CT

The impending coastal crisis

Coastlines are the most dynamic feature on the planet. In the March issue, Geotimes magazine looks into the risks of increased development along our coastlines and what that means for erosion, flooding and future development.

As coastal communities grow, so does the call for human-made structures to prevent local beach erosion. But what do these structures mean for the overall health of surrounding coastal areas?

Geotimes follows the erosion patterns of the southern shore of Long Island, starting with its recovery from the 1938 Long Island New England Hurricane. The noticeable change in landscape after the Category-3 hurricane caused a demand for structures that would stabilize the remaining inlets. While the structures did help the situation locally, erosion increased elsewhere, creating a need for more engineered structures.

What happens to the land when normal erosional patterns are altered? Geotimes studies the effects noreasters that struck Long Island in the early part of 1990s, decades after bulkheads and jetties were put in place. Did the residents learn from past mistakes when rebuilding after the storms of the 90s?........ Posted by: Beverly      Read more         Source

March 12, 2008, 9:33 PM CT

Rivers Play Part In Removing Nitrogen

Tiny organisms play a powerful role in removing nitrate, a form of nitrogen pollution caused by human activity, in streams, as per a research studyby a team led by Oak Ridge National Laboratory and published in Nature.

In the first phase of the study, which involved 31 aquatic researchers from across the United States, scientists added small amounts of an uncommon non-radioactive isotope of nitrogen to 72 streams across the U.S. and Puerto Rico. Using this tracer, the team's objective was to measure how far downstream the nitrate traveled and how it was removed from water.

"We observed that the nitrate was filtered from stream water by tiny organisms such as algae, fungi and bacteria," said Patrick Mulholland, lead author of the study and a member of Oak Ridge National Laboratory's Environmental Sciences Division. Mulholland has a joint appointment at the University of Tennessee.

The scientists also observed that a considerable amount of nitrate was removed from streams by a bacterially mediated process known as denitrification, which converts nitrate to nitrogen gas. That gas then escapes harmlessly to the atmosphere, Mulholland said.

In the second phase of the study, the researchers developed a model to study nitrate removal from water within river networks. These networks develop as small streams flow into larger streams and rivers......... Posted by: Beverly      Read more         Source

March 9, 2008, 4:52 PM CT

GLAST Spacecraft Arrives in Florida

NASA's Gamma-ray Large Area Space Telescope, or GLAST, arrived Tuesday at the Astrotech payload processing facility near the Kennedy Space Center to begin final preparations for launch. Liftoff of GLAST aboard a Delta II rocket is currently targeted for 11:45 a.m. EDT on May 16.

GLAST is a collaborative mission with the U.S. Department of Energy, international partners from France, Germany, Italy, Japan and Sweden, and numerous academic institutions from the U.S. and abroad. The spacecraft will explore the most extreme environments in the universe, and answer questions about supermassive black hole systems, pulsars and the origin of cosmic rays. It also will study the mystery of powerful explosions known as gamma-ray bursts.

The milestones to be accomplished over the next two months include attaching the Ku-band communications antenna and the two sets of solar arrays, a complete checkout of GLAST's scientific instruments, installing the spacecraft's battery, and loading aboard the observatory's propellant. These activities will be performed by General Dynamics, builder of the spacecraft for NASA. GLAST currently is scheduled to be transported to Pad 17-B at Cape Canaveral Air Force Station on May 1.

The rocket that will launch GLAST is a Delta II 7920-H, manufactured and prepared for launch by United Launch Alliance. It is a heavier-lift model of the standard Delta II that uses larger solid rocket boosters. The first stage is scheduled to be erected on Pad 17-B the week of March 17......... Posted by: Beverly      Read more         Source

March 5, 2008, 7:48 PM CT

Containing Carbon Dioxide

Injecting CO2, the most troublesome greenhouse gas, into porous rock formations beneath the earth might be the best short-term option for slowing global warming. Los Alamos researchers are in the process of developing a comprehensive risk assessment program to ensure safe and effective CO2 containment. This program includes a unique computer model, named "CO2-PENS," to guide the choice and development of the best sites; laboratory experiments to understand the geochemistry of sequestration systems; and field studies to quantify natural CO2 flux in the ecosystem. Los Alamos has advanced its geologic sequestration research by partnering with the Enhanced Oil Recovery Industry, which has injected CO2 underground for 30 years.

The average American family of four puts about three tons of garbage per year by the curb, but because we burn fossil fuels for electricity, heat, and transportation, that same family is annually responsible for dumping about 80 tons of carbon dioxide (CO2) into the atmosphere-CO2 that contributes to global climate change.

Some believe we should just stop using fossil fuels, but that won't happen in the near future unless we're willing to cripple our economy and keep the developing world in poverty. Eighty-six percent of the world's energy comes from fossil fuels, and projections show energy demand and fossil fuel use rising dramatically. China, India, and the United States are planning to add 850 new coal-fired power plants to the 2,100 worldwide that currently chug out one-third of the world's human-generated CO2 emissions......... Posted by: Beverly      Read more         Source

March 4, 2008, 5:50 PM CT

Nuclear cannibals

Nuclear energy production must increase by more than 10 percent each year from 2010 to 2050 to meet all future energy demands and replace fossil fuels, but this is an unsustainable prospect. As per a report published in Inderscience's International Journal of Nuclear Governance, Economy and Ecology such a large growth rate will require a major improvement in nuclear power efficiency otherwise each new power plant will simply cannibalize the energy produced by earlier nuclear power plants.

Physicist Joshua Pearce of Clarion University of Pennsylvania has attempted to balance the nuclear books and finds the bottom line simply does not add up. There are several problems that he says cannot be overcome if the nuclear power option is taken in preference to renewable energy sources.

For example, the energy input mandatory from mining and processing uranium ore to its use in a power plant that costs huge amounts of energy to build and operate cannot be offset by power production in a high growth scenario. There are also growth limits set by the grade of uranium ore. "The limit of uranium ore grade to offset greenhouse gas emissions is significantly higher than the purely thermodynamic limit set by the energy payback time," he explains.

In addition, nuclear power produces a lot of heat as a byproduct and this directly heats the Earth. This is only a relatively small effect, but as energy consumption grows it must be taken into consideration when balancing the energy equation......... Posted by: Beverly      Read more         Source

March 2, 2008, 9:00 PM CT

A screening strategy using zebrafish targets

A small striped fish is helping researchers understand what makes people susceptible to a common form of hearing loss, although, in this case, its not the fishs ears that are of interest. As per a research findings published on February 29 in the open-access journal PLoS Genetics, scientists at the University of Washington have developed a research method that relies on a zebrafishs lateral linethe faint line running down each side of a fish that enables it to sense its surroundingsto quickly screen for genes and chemical compounds that protect against hearing loss from some medications. The study was funded in part by the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health.

The fishs lateral line contains sensory cells that are functionally similar to those found in the inner ear, except these are on the surface of the fishs body, making them more easily accessible, said James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. This means that researchers can very efficiently analyze the sensory structures under different conditions to find out what is likely to cause damage to these structures and, on the other hand, what can protect them from damage.

When people are exposed to some antibiotics and chemotherapy agents, the sensory structures in the inner ear, called hair cells, can be irreversibly damaged, resulting in hearing loss and balance problems. These are known as ototoxic medications. People vary widely in their susceptibility to these agents as well as to damage caused by other chemical agents, loud sounds and aging......... Posted by: Beverly      Read more         Source

February 28, 2008, 10:41 PM CT

Is Your Drinking Water Safe?

Lake Bloomington is a major source of drinking water for residents of Bloomington, IL, and has a history of nitrate concentrations that exceed safe levels. Because Lake Bloomington has a record of elevated nitrate levels, local residents are concerned over their drinking water quality.

Kenneth Smiciklas, Associate Professor of Agronomy, Illinois State University, along with a team of colleagues, present an article about the nitrate levels in Central Illinois in the 2008 Journal of Natural Resources and Life Sciences Education.

As per Smiciklas, "Drinking water contaminated with nitrate concentrations exceeding the maximum contaminant level established by the USEPA can cause health effects in humans and animals".

Nitrate-nitrogen is a form of nitrogen that is naturally occurring in most soils. Nitrogen fertilizers added to the soil for crop production can also add to the soil nitrate concentration. If these amounts become extreme, drinking water quality can be affected.

More than 90% of the area in the Lake Bloomington watershed is used for agriculture. The application of nitrate fertilizers (both synthetic and organic) in the growing food crops can result in relatively high levels of nitrate in the surrounding waters. Non-agricultural sources of nitrate can include natural mineralization occurring primarily in the spring due to organic matter breakdown and also from septic emissions......... Posted by: Beverly      Read more         Source

February 26, 2008, 10:08 PM CT

Engineering first system of human nerve-cell tissue

Scientists at the University of Pennsylvania School of Medicine have demonstrated that living human nerve cells can be engineered into a network that could one day be used for transplants to repair damaged to the nervous system. They report their findings in the recent issue of the Journal of Neurosurgery.

We have created a three-dimensional neural network, a mini nervous system in culture, which can be transplanted en masse, explains senior author Douglas H. Smith, MD, Professor, Department of Neurosurgery and Director of the Center for Brain Injury and Repair at Penn.

Eventhough neuron transplantation to repair the nervous system has shown promise in animal models, there are few sources of viable neurons for use in the clinic and insufficient approaches to bridge extensive nerve damage in patients.

The Stretch Test.

In prior work, Smiths group showed that they could induce tracts of nerve fibers called axons to grow in response to mechanical tension. They placed neurons from rat dorsal root ganglia (clusters of nerves just outside the spinal cord) on nutrient-filled plastic plates. Axons sprouted from the neurons on each plate and connected with neurons on the other plate. The plates were then slowly pulled apart over a series of days, aided by a precise computer-controlled motor system, creating long tracts of living axons......... Posted by: Beverly      Read more         Source

Wed, 13 Feb 2008 01:38:11 GMT

Hulsea algida

A new contributor today! Thank you to mdv_graupe@Flickr for sharing today''s photograph with us (original via the BPotD Flickr Group Pool). It''s very appreciated.

Common names for Hulsea algida include alpine hulsea, Pacific hulsea, alpine gold hulsea. The names tend to suggest a high-elevation grower, and indeed it is: this photograph was taken at 4000m (or 13 300 ft.). It is generally found in the western USA: California, Nevada, Oregon, Idaho, Montana and Wyoming (Utah is intriguingly absent).

The Jepson Manual provides its usual excellent description of the species: Hulsea algida. Frequent BPotD contributor Michael Charters has a page about it as well, with links to the meaning of the names (e.g., algida means “golden cold” – see comments below): alpine gold hulsea. More photographs are available via CalPhotos. Posted by: Daniel Mosquin      Read more     Source

February 10, 2008, 10:23 PM CT

Low-calorie sweeteners are helpful in weight control

A recent review of the scientific literature concluded that low-calorie (or no-calorie) sweeteners may be of help in resolving the obesity problem. Eventhough they are not magic bullets, low-calorie sweeteners in beverages and foods can help people reduce their calorie (energy) intakes. Low-calorie sweeteners reduce the energy of most beverages to zero and lower the energy density of a number of foods, said co-author of study, Dr. Adam Drewnowski, Director, Center for Public Health Nutrition at the University of Washington. Every dietary guideline these days tells us to bulk up, hydrate, and consume foods with fewer calories but more volume.

The study by Bellisle and Drewnowski, reported in the European Journal of Clinical Nutrition, reviewed a variety of laboratory, clinical and epidemiological studies on low-calorie sweeteners, energy density and satiety. Their findings, based on extensive studies with humans, are completely at odds with a new study on 27 Sprague-Dawley rats eating yogurt, reported in the recent issue of Behavioral Neuroscience.

The February study, A Role for Sweet Taste: Caloric Predictive Relations in Energy Regulation by Rats, alleges a link between low-calorie sweeteners and weight gain. However, prior studies in humans have shown that low-calorie sweeteners can be helpful in weight control. Everything old is new again: similar studies on the uncoupling of sweetness and calories in humans were conducted back in 1989 and to no great effect, noted Drewnowski. Among criticisms of the study identified by nutrition experts were:........ Posted by: Beverly      Read more         Source