November 13, 2007, 9:21 PM CT

River Restoration Poorly Coordinated

The process of river restoration in the U.S. is uncoordinated at almost every level. Project scales are rarely associated with goals, and evaluation is rarely reported or used to assess whether these goals are achieved. A new study published in Restoration Ecology is the first attempt to systematically determine the motivations behind river restoration throughout the U.S., and to assess the ways in which projects are being reviewed.

Despite considerable optimism from restoration project managers, two-thirds of whom felt that their restorations had been "completely successful," the study finds that the process of river restoration is poorly coordinated. Project goals, design, implementation and evaluation are disconnected. Evaluations are uncommon and are rarely reported or used to assess whether goals have been met. The study also finds little coordination between separate projects, something that is essential for successfully addressing watershed degradation.

River restoration is a popular approach to watershed management in the U.S., where over one-third of all rivers are degraded due to alterations in the shape of river channels, chemistry of the waters and the timing and amount of water they receive. Each year more than $1 billion is spent on these projects......... Posted by: Tyler      Read more         Source

November 13, 2007, 9:17 PM CT

Supplemental Math Programs As Holiday Gift

Parents of school-aged children might want to think of giving their children an enduring holiday gift this year: enrollment in a supplemental mathematics program. While it can cost anywhere from $80 to $110 a month, the results of practicing mathematics nearly daily is rewarding to both students and parents. In fact, parents might be even bigger recipients of this gift than their children. While their children gain self-esteem and confidence, the parents very likely will feel a sense of relief and pride in their children's accomplishment.

Singapore, Saxon and Kumon are three popular such programs. A number of home-school practitioners use the first two, and Kumon, which involves daily practice and some tutoring, is popular with parents who feel their schools might be letting them down.

Dan Kimura, Ph.D., a senior professor of computer science and engineering at Washington University in St. Louis, opened St. Louis' first Kumon center in 1984, in large part because of his disappointment in the math education that his sons were getting. Mathematics is a major foundation of computer science, and Kimura, whose specialty is software programming, took action.

Begun in Kimura's hometown, Moriguchi, Japan, in 1958 by the late Toru Kumon, a math teacher who invented it to help his sons, Kumon math has more than four million students enrolled worldwide in 43 countries, nearly 180,000 in the United States. The method stresses repetition, speed, accuracy, individual pace, hard work and goal orientation in teaching mathematics......... Posted by: Jaison      Read more         Source

November 12, 2007, 9:49 PM CT

Human ancestors: more gatherers than hunters?

Chimpanzees crave roots and tubers even when food is plentiful above ground, as per a new study that raises questions about the relative importance of meat for brain evolution.

Appearing online the week of Nov. 12 in the early edition of the Proceedings of the National Academy of Sciences, the study documents a novel use of tools by chimps to dig for tubers and roots in the savanna woodlands of western Tanzania.

The chimps eagerness for buried treats offers new insights in an ongoing debate about the role of meat versus potato-like foods in the diet of our hominid ancestors, said first author Adriana Hernandez-Aguilar, who collected the field data for her doctoral research at the University of Southern California.

The debate centers on the diet followed by early hominids as their brain and body size slowly increased towards a human level. Was it meat-and-potatoes, or potatoes-and-meat".

Some scientists have suggested that what made us human was actually the tubers, Hernandez-Aguilar said.

Anthropologists had speculated that roots and tubers were mere fallback foods for hominids trying to survive the harsh dry season in the savanna 3.5 million years ago and later (hominids are known to have consumed meat at least as early as 2.5 million years ago)......... Posted by: William      Read more         Source

November 12, 2007, 9:02 PM CT

Smart dust, gassy antennas, and warp speed calculations

Tiny probes packed with instrumentation have been turned loose in a laboratory in France. The marble-sized devices are an important step on the road to long-anticipated miniaturized machines known as smart dust (picture the artificial swarm in Michael Creighton's "Prey," only without the bloodlust). The small and simple machines are being developed to be released in large numbers to collect data about the motion of fluid systems such as ocean currents and atmospheric winds.

The two centimeter probes are on the large side for smart dust (typically, miniature machines must fill a volume of a cubic centimeter or less to make the cut), still the probes' abilities are impressive for their size. They float freely underwater, measure local temperatures down to a millionth of a degree Kelvin, and send it all back wirelessly. Prior devices used for similar measurements had to remain above water or stay in one place.

The team of physicists that made the smart particles at the Université de Lyon used them to track the paths of tiny heat packets that travel through fluids, showing that the packets follow a regular pattern. The scientists are hopeful that the device will teach them more about the motion of particles in turbulent systems, including hurricanes and mixtures of reactive chemicals. - CC......... Posted by: Kevin      Read more         Source

November 8, 2007, 10:05 PM CT

Smile, protons, you're on camera

Radioactivity, discovered more than 100 years ago and studied by physicists ever since, would seem to be a relatively closed subject in science. However, since the 1960s, the pursuit of at least one open question about how nuclei spontaneously eject various particles has continued to nag experimentalists, largely because of an inability to make precise measurements of fleeting, exotic nuclei.

In a paper published this week in Physical Review Letters, an international collaboration of researchers, led by Marek Pfutzner, a physicist from Warsaw University in Poland, takes several steps toward an answer. The researchers describe a first-ever success in peering closely at radioactive decay of a rare iron isotope at the ragged edge of the known nuclear map. The tools used to achieve this result include a novel combination of advanced physics equipment and imaging technology that is found in most off-the-shelf digital cameras.

"We have proved in a direct and clear way that this extremely neutron-deficient nucleus disintegrates by the simultaneous emission of two protons," write the authors.

Pfutzner and his collaborators set out to better understand an exotic form of radioactivity -- two-proton emissions from iron-45, a nucleus with 26 protons and 19 neutrons. The stable form of iron that is most abundant on Earth has 26 protons and 30 neutrons. One possibility was that the iron-45 isotope might occasionally release an energetically linked two-proton pair, known as a diproton. Other possibilities were that the protons, whether emitted in quick succession or simultaneously, were unlinked......... Posted by: Sarah      Read more         Source

November 8, 2007, 10:02 PM CT

Mini Magnetic Sensor May Have Biomedical Applications

A tiny sensor that can detect magnetic field changes as small as 70 femtoteslas-equivalent to the brain waves of a person daydreaming-has been demonstrated at the National Institute of Standards and Technology (NIST). The sensor could be battery-operated and could reduce the costs of noninvasive biomagnetic measurements such as fetal heart monitoring. The device also may have applications in homeland security screening for explosives.

Described in the recent issue of Nature Photonics,* the prototype device is almost 1,000 times more sensitive than NIST's original chip-scale magnetometer demonstrated in 2004 ("Tiny, Atom-based Detector Senses Weak Magnetic Fields") and is based on a different operating principle. Its performance puts it within reach of matching the current gold standard for magnetic sensors, so-called superconducting quantum interference devices or SQUIDs. These devices can sense changes in the 3- to 40-femtotesla range but must be cooled to very low (cryogenic) temperatures, making them much larger, power hungry, and more expensive.

The NIST prototype consists of a single low-power (milliwatt) infrared laser and a rice-grain-sized container with dimensions of 3 by 2 by 1 millimeters. The container holds about 100 billion rubidium atoms in gas form. As the laser beam passes through the atomic vapor, researchers measure the transmitted optical power while varying the strength of a magnetic field applied perpendicular to the beam. The amount of laser light absorbed by the atoms varies predictably with the magnetic field, providing a reference scale for measuring the field. The stronger the magnetic field, the more light is absorbed......... Posted by: Kevin      Read more         Source

November 8, 2007, 10:00 PM CT

Micro Microwave Does Pinpoint Cooking

Scientists at the National Institute of Standards and Technology (NIST) and George Mason University have demonstrated what is probably the world's smallest microwave oven, a tiny mechanism that can heat a pinhead-sized drop of liquid inside a container slightly shorter than an ant and half as wide as a single hair. The micro microwave is intended for lab-on-a-chip devices that perform rapid, complex chemical analyses on tiny samples.

In a paper in the November 2007 Journal of Micromechanics and Microengineering*, the research team led by NIST engineer Michael Gaitan describes for the first time how a tiny dielectric microwave heater can be successfully integrated with a microfluidic channel to control selectively and precisely the temperature of fluid volumes ranging from a few microliters (millionth of a liter) to sub-nanoliters (less than a billionth of a liter). Sample heating is an essential step in a wide range of analytic techniques that could be built into microfluidic devices, including the high-efficiency polymerase chain reaction (PCR) process that rapidly amplifies tiny samples of DNA for forensic work, and methods to break cells open to release their contents for study.

The team embedded a thin-film microwave transmission line between a glass substrate and a polymer block to create its micro microwave oven. A trapezoidal-shaped cut in the polymer block only 7 micrometers across at its narrowest-the diameter of a red blood cell-and nearly 4 millimeters long (approximately the length of an ant) serves as the chamber for the fluid to be heated......... Posted by: Kevin      Read more         Source

November 7, 2007, 8:42 PM CT

Higher levels of pollutants found in fish

Emissions from coal-fired power plants may be an important source of water pollution and fish contamination, say scientists at the University of Pittsburgh Graduate School of Public Health in a study being presented at the annual meeting of the American Public Health Association in Washington, D.C. The study, abstract number 157770, found higher-than-Environmental Protection Agency (EPA)-recommended levels of mercury and elevated levels of selenium in channel catfish caught in a rural area upstream of Pittsburgh and downwind from a coal-fired power plant. Both mercury and selenium are well-known contaminants of coal burning for power generation. The results will be presented at a special session on Contaminants in Freshwater Fish: Toxicity, Sources and Risk Communication, at 8:30 a.m., Wednesday, Nov. 7.

To complete the study, scientists recruited local anglers to catch channel catfish from the three rivers area of Pittsburgh and from Kittanning, Pa., an area 40 miles upstream of Pittsburgh. The three rivers area includes the Allegheny, Monongahela and Ohio rivers. Based on testing of 63 fish, they observed that Kittanning and three rivers area fish had 19 and 3.1 times more mercury, respectively, than store-bought fish. They also found significantly higher levels of mercury and selenium in the Kittanning-caught fish than in the fish caught in the three rivers area......... Posted by: Sean      Read more         Source

November 7, 2007, 6:59 PM CT

LHC completes the circle

At a brief ceremony deep under the French countryside today, CERN1 Director General Robert Aymar sealed the last interconnect in the world's largest cryogenic system, the Large Hadron Collider (LHC). This is the latest milestone in commissioning the LHC, the world's most powerful particle accelerator.

The LHC's cryogenic system has the task of cooling some 36 800 tonnes of material to a temperature of just 1.9 degrees above absolute zero (-271.3 degree C), colder than outer space. To do this, over 10 000 tonnes of liquid nitrogen and 130 tonnes of liquid helium will be deployed through a cryogenic system including over 40 000 leak-tight welds. Today's ceremony marks the end of a two year programme of work to connect all the main dipole and quadrupole magnets in the LHC. This complex task included both electrical and fluid connections.

"This is a huge accomplishment," said Lyn Evans, LHC project leader. "Now that it is done, we can concentrate on getting the machine cold and ready for physics."

The LHC is a circular machine, 27 kilometres around and divided into eight sectors, each of which can be cooled down to its operating temperature of 1.9 degrees above absolute zero and powered-up individually. One sector was cooled down, powered and warmed up in the first half of 2007. This was an important learning process, allowing subsequent sectors to be tested more quickly......... Posted by: Sarah      Read more         Source

November 7, 2007, 4:54 AM CT

Climate Change Could Diminish Drinking Water

As sea levels rise, coastal communities could lose up to 50 percent more of their fresh water supplies than previously thought, as per a new study from Ohio State University.

Hydrologists here have simulated how saltwater will intrude into fresh water aquifers, given the sea level rise predicted by the Intergovernmental Panel on Climate Change (IPCC). The IPCC has concluded that within the next 100 years, sea level could rise as much as 23 inches, flooding coasts worldwide.

Researchers previously assumed that, as saltwater moved inland, it would penetrate underground only as far as it did above ground.

But this new research shows that when saltwater and fresh water meet, they mix in complex ways, depending on the texture of the sand along the coastline. In some cases, a zone of mixed, or brackish, water can extend 50 percent further inland underground than it does above ground.

Like saltwater, brackish water is not safe to drink because it causes dehydration. Water that contains less than 250 milligrams of salt per liter is considered fresh water and safe to drink.

Motomu Ibaraki, associate professor of earth sciences at Ohio State, led the study. Graduate student Jun Mizuno presented the results Tuesday, October 30, 2007, at the Geological Society of America meeting in Denver......... Posted by: Tyler      Read more         Source