New Compact Microspectrometer Design Achieves High Resolution and Wide Bandwidth

A new microspectrometer architecture that uses compact disc-shaped resonators could address the challenges of integrated lab-on-chip sensing systems that now require a large off-chip spectrometer to achieve high resolution. Spectrometers have conventionally been expensive and bulky bench-top instruments used to detect and identify the molecules inside a sample by shining light on it and measuring different wavelengths of the emitted or absorbed light. Previous efforts toward miniaturizing spectrometers have reduced their size and cost, but these reductions have typically resulted in lower-resolution instruments.

"For spectrometers, it is better to be small and cheap than big and bulky -- provided that the optical performance targets are met," said Ali Adibi, a professor in the School of Electrical and Computer Engineering at the Georgia Institute of Technology. "We were able to achieve high resolution and wide bandwidth with a compact single-mode on-chip spectrometer through the use of an array of microdonut resonators, each with an outer radius of two microns."

The 81-channel on-chip spectrometer designed by Georgia Tech engineers achieved 0.6-nanometer resolution over a spectral range of more than 50 nanometers with a footprint less than one square millimeter. The simple instrument -- with its ultra-small footprint -- can be integrated with other devices, including sensors, optoelectronics, microelectronics and microfluidic channels for use in biological, chemical, medical and pharmaceutical applications.

The microspectrometer architecture was described in a paper published on June 20 in the journal Optics Express. The research was supported by the Air Force Office of Scientific Research and the Defense Advanced Research Projects Agency.

"This architecture is promising because the quality-factor of the microdonut resonators is higher than that of microrings of the same size," said Richard Soref, a research scientist in the U.S. Air Force Research Laboratory at Hanscom Air Force Base who was not directly involved in the research. "Having such small resonators is also an advantage because they can be densely packed on a chip, enabling a large spectrum to be sampled."

Adibi's group is currently developing the next generation of these spectrometers, which are being designed to contain up to 1000 resonators and achieve 0.15-nanomater resolution with a spectral range of 150 nanometers and footprint of 200 micrometers squared.

Adibi, current graduate student Zhixuan Xia and research engineer Ali A. Eftekhar, and former research engineers Babak Momeni and Siva Yegnanarayanan designed and implemented the microspectrometer using CMOS-compatible fabrication processes. The key building element they used to construct the device was an array of miniaturized microdonut resonators, which were essentially microdiscs perforated in their centers. This research built on former Georgia Tech graduate student Mohammad Soltani's work to develop miniature microresonators, which was published in the Sept. 13, 2010 issue of the journal Optics Express.

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Lowa State Hybrid Lab Combines Technologies To Make Biorenewable Fuels and Products

Laura Jarboe pointed to a collection of test tubes in her Iowa State University laboratory. Some of the tubes looked like they were holding very weak coffee. That meant microorganisms – in this case, Shewanella bacteria – were growing and biochemically converting sugars into hydrocarbons, said Jarboe, an Iowa State assistant professor of chemical and biological engineering.

Some of the sugars in those test tubes were produced by the fast pyrolysis of biomass. That's a thermochemical process that quickly heats biomass (such as corn stalks and leaves) in the absence of oxygen to produce a liquid product known as bio-oil and a solid product called biochar. The bio-oil can be used to manufacture fuels and chemicals; the biochar can be used to enrich soil and remove greenhouse gases from the atmosphere.

Iowa State's Hybrid Processing Laboratory on the first floor of the new, state-built Biorenewables Research Laboratory is all about encouraging that unique mix of biochemical and thermochemical technologies. The goal is for biologists and engineers to use the lab's incubators, reactors, gas chromatography instruments and anaerobic chambers to find new and better ways to produce biorenewable fuels and chemicals.

"Biological processes occur well below the boiling point of water, while thermal processes are usually performed hundreds of degrees higher, which makes it hard to imagine how these processes can be combined," said Robert C. Brown, an Anson Marston Distinguished Professor in Engineering, the Gary and Donna Hoover Chair in Mechanical Engineering, and the Iowa Farm Bureau Director of Iowa State's Bioeconomy Institute.

"In fact, these differences in operating regimes represent one of the major advantages of hybrid processing," Brown said. "High temperatures readily break down biomass to substrates that can be fermented to desirable products."

Jarboe's research is one example. She's trying to develop bacteria that can grow and thrive in the chemicals and compounds that make up bio-oil. That way, they can ferment the sugars from bio-oil with greater efficiency and produce more biorenewable fuels or chemicals.

Another example of mixing the biochemical with the thermochemical is the work of Zhiyou Wen, an associate professor of food science and human nutrition, and Yanwen Shen, a doctoral student in his research group.

They're working to break down a bottleneck in the fermentation of synthesis gas – a mixture of carbon monoxide and hydrogen that's produced by the partial combustion of biomass in a gasifier. The fermentation process slows when researchers dissolve the gas into a liquid that can be used by microorganisms to produce biofuels. They're looking for bioreactor technologies that boost the mass transfer of the synthesis gas without adding energy costs.

A third example is the work of DongWon Choi, a former doctoral student and post-doctoral research associate at Iowa State who's now an assistant professor of biological and environmental sciences at Texas A&M University Commerce. He continues to collaborate in the hybrid lab by working with microalgae that convert carbon dioxide into oil that can be used to produce biofuels.

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Discovery Of Parathyroid Glow Promises To Reduce Endocrine Surgery Risk

The parathyroid glands – four small organs the size of grains of rice located at the back of the throat – glow with a natural fluorescence in the near infrared region of the spectrum. This unique fluorescent signature was discovered by a team of biomedical engineers and endocrine surgeons at Vanderbilt University, who have used it as the basis of a simple and reliable optical detector that can positively identify the parathyroid glands during endocrine surgery.

The report of the discovery of parathyroid fluorescence and the design of the optical detector was published in the June issue of the Journal of Biomedical Optics.

Damage to these tiny organs can have deleterious, life-long effects on patients' health because they produce a hormone that controls critical calcium concentrations in bones, intestines and kidneys. However, the parathyroid glands are very difficult to identify with the naked eye. Not only are they small, but their location also varies widely from person to person and it takes a microscope to reliably tell the difference between parathyroid tissue and the thyroid and lymph tissue that surrounds it.

In 2004, more than 80,000 endocrine surgeries were performed in the United States and this number is projected to grow to more than 100,000 by 2020. Today, when a surgeon cuts into a patient's neck to remove a diseased thyroid, somewhere between 8 to 19 percent of the time the patient's parathyroid glands are also damaged or removed.

Parathyroid glow is surprisingly strong

"We have discovered that the parathyroid glands are two to 10 times more fluorescent in the near infrared than any other tissues found in the neck," said Professor of Biomedical Engineering Anita Mahadevan-Jansen, who directed the study. "We have taken measurements with more than 50 patients now and we have found this effect 100 percent of the time, even when the tissue is diseased. That is amazing. You almost never get 100 percent results in biological studies."

The fluorescence is so strong that it doesn't take expensive or sophisticated instruments to detect. The Vanderbilt researchers have assembled a detector from off-the-shelf hardware. It consists of a low-powered infrared laser connected to an optical fiber probe. As the fiber connected to the laser illuminates the tissue with invisible near infrared light, other fibers in the probe are connected to a detector that measures the strength of the fluorescence that the laser excites. The university has applied for an international patent that covers this application.

"I was certainly impressed with how accurate this method seems to be," said John Phay, an endocrine surgeon at the Ohio State University Medical Center, who collaborated in the study when he was at Vanderbilt. "The ability to detect the parathyroids would be a big help: The major problem in parathyroid surgery is finding them and it is very hard to avoid them in thyroid cancer surgery when you need to clear out lymph nodes."

Using the first generation of the device was "a bit burdensome, because you have to dim the lights," Phay commented. This will not be a problem with the next version, because it will include a filter that will block out visible light. According to the surgeon, the system will be the most useful with the planned addition of a camera that displays the fluorescence of all the tissues in the throat on a single display.

Project begins with curiosity of first-year surgery resident

The story of discovery began in 2007 when Lisa White, a first-year resident in the Vanderbilt surgery department, participated in her first neck surgery. "It was a very difficult case," White said. "We were looking for the parathyroid glands and they were very hard to find, although we finally did find them. After the surgery was over, I decided that we really need a better way of identifying parathyroid tissue."

This conclusion led White to conduct a literature search of the research that has been conducted on the basic physiology and biochemistry of the parathyroid. In the process she came across a paper written by Mahadevan-Jansen with another intern that described an optical technique that can detect liver cancer.

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Fastest Sea-level Rise İn 2 Millennia Linked To İncreasing Global TemperaturesThe rate of sea level rise along the U.S. Atlantic coast is greater now

The rate of sea level rise along the U.S. Atlantic coast is greater now than at any time in the past 2,000 years--and has shown a consistent link between changes in global mean surface temperature and sea level. The findings are published this week in the journal Proceedings of the National Academy of Sciences (PNAS).

The research, funded by the National Science Foundation (NSF), was conducted by Andrew Kemp, Yale University; Benjamin Horton, University of Pennsylvania; Jeffrey Donnelly, Woods Hole Oceanographic Institution; Michael Mann, Pennsylvania State University; Martin Vermeer, Aalto University School of Engineering, Finland; and Stefan Rahmstorf, Potsdam Institute for Climate Impact Research, Germany.

"Having a detailed picture of rates of sea level change over the past two millennia provides an important context for understanding current and potential future changes," says Paul Cutler, program director in NSF's Division of Earth Sciences.

"It's especially valuable for anticipating the evolution of coastal systems," he says, "in which more than half the world's population now lives."

Adds Kemp, "Scenarios of future rise are dependent on understanding the response of sea level to climate changes. Accurate estimates of past sea-level variability provide a context for such projections."

Kemp and colleagues developed the first continuous sea-level reconstruction for the past 2,000 years, and compared variations in global temperature to changes in sea level over that time period.

The team found that sea level was relatively stable from 200 BC to 1,000 AD.

Then in the 11th century, sea level rose by about half a millimeter each year for 400 years, linked with a warm climate period known as the Medieval Climate Anomaly.

Then there was a second period of stable sea level during a cooler period called the Little Ice Age. It persisted until the late 19th century.

Since the late 19th century, sea level has risen by more than 2 millimeters per year on average, the steepest rate for more than 2,100 years.

"Sea-level rise is a potentially disastrous outcome of climate change," says Horton, "as rising temperatures melt land-based ice, and warm ocean waters."

To reconstruct sea level, the scientists used microfossils called foraminifera preserved in sediment cores extracted from coastal salt marshes in North Carolina. The age of the cores was estimated using radiocarbon dating and other techniques.

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Nanoparticles Disguised As Red Blood Cells Will Deliver Cancer-fighting Drugs

Researchers at the University of California, San Diego have developed a novel method of disguising nanoparticles as red blood cells, which will enable them to evade the body's immune system and deliver cancer-fighting drugs straight to a tumor. Their research will be published next week in the online Early Edition of the Proceedings of the National Academy of Sciences. The method involves collecting the membrane from a red blood cell and wrapping it like a powerful camouflaging cloak around a biodegradable polymer nanoparticle stuffed with a cocktail of small molecule drugs. Nanoparticles are less than 100 nanometers in size, about the same size as a virus.

"This is the first work that combines the natural cell membrane with a synthetic nanoparticle for drug delivery applications." said Liangfang Zhang, a nanoeningeering professor at the UC San Diego Jacobs School of Engineering and Moores UCSD Cancer Center. "This nanoparticle platform will have little risk of immune response".

Researchers have been working for years on developing drug delivery systems that mimic the body's natural behavior for more effective drug delivery. That means creating vehicles such as nanoparticles that can live and circulate in the body for extended periods without being attacked by the immune system. Red blood cells live in the body for up to 180 days and, as such, are "nature's long-circulation delivery vehicle," said Zhang's student Che-Ming Hu, a UCSD Ph.D. candidate in bioengineering, and first author on the paper.

Stealth nanoparticles are already used successfully in clinical cancer treatment to deliver chemotherapy drugs. They are coated in a synthetic material such as polyethylene glycol that creates a protection layer to suppress the immune system so that the nanoparticle has time to deliver its payload. Zhang said today's stealth nanoparticle drug delivery vehicles can circulate in the body for hours compared to the minutes a nanoparticle might survive without this special coating.

But in Zhang's study, nanoparticles coated in the membranes of red blood cells circulated in the bodies of lab mice for nearly two days. The study was funded through a grant from the National Institute of Health.

A shift towards personalized medicine

Using the body's own red blood cells marks a significant shift in focus and a major breakthrough in the field of personalized drug delivery research. Trying to mimic the most important properties of a red blood cell in a synthetic coating requires an in-depth biological understanding of how all the proteins and lipids function on the surface of a cell so that you know you are mimicking the right properties. Instead, Zhang's team is just taking the whole surface membrane from an actual red blood cell.

"We approached this problem from an engineering point of view and bypassed all of this fundamental biology," said Zhang. "If the red blood cell has such a feature and we know that it has something to do with the membrane -- although we don't fully understand exactly what is going on at the protein level -- we just take the whole membrane. You put the cloak on the nanoparticle, and the nanoparticle looks like a red blood cell."

Using nanoparticles to deliver drugs also reduces the hours it takes to slowly drip chemotherapy drug solutions through an intravenous line to just a few minutes for a single injection of nanoparticle drugs. This significantly improves the patient's experience and compliance with the therapeutic plan. The breakthrough could lead to more personalized drug delivery wherein a small sample of a patient's own blood could produce enough of the essential membrane to disguise the nanoparticle, reducing the risk of immune response to almost nothing.

Zhang said one of the next steps is to develop an approach for large-scale manufacturing of these biomimetic nanoparticles for clinical use, which will be done through funding from the National Science Foundation. Researchers will also add a targeting molecule to the membrane that will enable the particle to seek and bind to cancer cells, and integrate the team's technology for loading drugs into the nanoparticle core so that multiple drugs can be delivered at the same time.

Zhang said being able to deliver multiple drugs in a single nanoparticle is important because cancer cells can develop a resistance to drugs delivered individually. By combining them, and giving the nanoparticle the ability to target cancer cells, the whole cocktail can be dropped like a bomb from within the cancer cell.

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University of Minnesota Engineering Researchers Discover Source For Generating 'Green' Electricity

University of Minnesota engineering researchers in the College of Science and Engineering have recently discovered a new alloy material that converts heat directly into electricity. This revolutionary energy conversion method is in the early stages of development, but it could have wide-sweeping impact on creating environmentally friendly electricity from waste heat sources. Researchers say the material could potentially be used to capture waste heat from a car's exhaust that would heat the material and produce electricity for charging the battery in a hybrid car. Other possible future uses include capturing rejected heat from industrial and power plants or temperature differences in the ocean to create electricity. The research team is looking into possible commercialization of the technology.

"This research is very promising because it presents an entirely new method for energy conversion that's never been done before," said University of Minnesota aerospace engineering and mechanics professor Richard James, who led the research team."It's also the ultimate 'green' way to create electricity because it uses waste heat to create electricity with no carbon dioxide."

To create the material, the research team combined elements at the atomic level to create a new multiferroic alloy, Ni45Co5Mn40Sn10. Multiferroic materials combine unusual elastic, magnetic and electric properties. The alloy Ni45Co5Mn40Sn10 achieves multiferroism by undergoing a highly reversible phase transformation where one solid turns into another solid. During this phase transformation the alloy undergoes changes in its magnetic properties that are exploited in the energy conversion device.

During a small-scale demonstration in a University of Minnesota lab, the new material created by the researchers begins as a non-magnetic material, then suddenly becomes strongly magnetic when the temperature is raised a small amount. When this happens, the material absorbs heat and spontaneously produces electricity in a surrounding coil. Some of this heat energy is lost in a process called hysteresis. A critical discovery of the team is a systematic way to minimize hysteresis in phase transformations. The team's research was recently published in the first issue of the new scientific journal Advanced Energy Materials.

Watch a short research video of the new material suddenly become magnetic when heated: http://z.umn.edu/conversionvideo.

In addition to Professor James, other members of the research team include University of Minnesota aerospace engineering and mechanics post-doctoral researchers Vijay Srivastava and Kanwal Bhatti, and Ph.D. student Yintao Song. The team is also working with University of Minnesota chemical engineering and materials science professor Christopher Leighton to create a thin film of the material that could be used, for example, to convert some of the waste heat from computers into electricity.

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Chemists Create Molecular Flasks

Chemical reactions happen all of the time: some things burn or rust, others react to light exposure--even batteries use chemical reactions to supply electricity. One of the big challenges chemists continually face is finding new ways to control these reactions or create conditions that promote desirable reactions and limit undesirable ones. Recently, researchers at New York University demonstrated an ability to make new materials with empty space on the inside, which could potentially control desired and unwanted chemical reactions.

Mike Ward, of NYU's Department of Chemistry and a team of researchers, essentially created a "molecular flask," self-assembling cages capable of housing other compounds inside of them. These "flasks" may eventually allow researchers to isolate certain chemical reactions within or outside the cage.

The research is published in the July 22, 2011 issue of the journal Science.

"We wanted to create frameworks to serve as the 'hotel' for 'guest' molecules, which can deliver the function independent of framework design," said Ward. "This makes it possible to separate chemicals based on size or perform reactions inside well-defined cages, which could potentially give you more control over chemical reactivity and reaction products. Moreover, these frameworks may prove ideal for encapsulating a wide range of guest molecules, producing materials with new optical or magnetic properties."

The molecular "hotels" described by Ward and his collaborators take the shape of a truncated octahedron, one of 13 shapes described as an Archimedean solid, discovered by the Greek mathematician Archimedes. Archimedean solids are characterized by a specific number of sides that meet at corners which are all identical. The regularity of these shapes often means they are of particular interest to chemists and materials researchers looking to create complex materials that assemble themselves.

The extraordinary aspect of this work, supported by the National Science Foundation (NSF), is the self-assembly of the molecular tiles into a polyhedron, a well-defined, three-dimensional, geometric solid. The individual polyhedra assemble themselves using the attractive interactions associated with hydrogen bonds. They then further organize into a crystal lattice that resembles a porous structure called zeolite, an absorbent material with many industrial uses.

The new material differs from zeolite because it is constructed from organic building blocks rather than inorganic ones, which make it more versatile and easier to engineer. In general, inorganic compounds are considered mineral in origin, while organic compounds are considered biological in origin.

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Researchers Target, Switch Off Serotonin-producing Neurons İn Mice

Researchers have developed a toolkit that enables them to turn off targeted cell populations while leaving others unaffected. Led by Susan Dymecki, a professor of genetics at Harvard Medical School, the group focused on serotonin-producing neurons, observing how mice behave in a normal environment when suddenly their serotonin neurons are turned down. While their findings affirm earlier studies, the researchers used a technique that is non-invasive and does not require anesthesia, surgeries, or knocking out a gene—each of which can cause problems when interpreting results.

"By selectively and abruptly switching off the serotonin-producing cells, we can get a definite idea of what bodily functions the serotonin cells specifically control," said Dymecki. "These findings and the new tools in neuroscience that it brings to the table will help us understand the role of serotonergic neurons in many human disorders."

One such disorder particularly relevant to these findings is Sudden Infant Death Syndrome, or SIDS.

These findings will appear in the July 29 edition of the journal Science.

The mammalian brain contains multiple chemical messengers, called neurotransmitters, which transfer information between nerve cells in order to regulate basic behaviors and functions like walking, eating, and sleeping. Serotonin is a major brain neurotransmitter produced solely by cells in the lower brain, or brainstem. Cells that make serotonin can convey information to large numbers of neurons distributed throughout the brain and can affect behavior as complex as mood.

In order to better understand how these serotonin-producing cells in the brain relate to basic physiology, Russell Ray and Rachael Brust, a postdoctoral researcher and a graduate student in Dymecki's lab, along with Jun Chul Kim, a prior postdoctoral fellow in Dymecki's lab who is now at the University of Toronto, and Andrea Corcoran, a postdoctoral researcher in the lab of Eugene Nattie at Dartmouth Medical School along with George Richerson, a professor of neurology at the University of Iowa, developed and characterized a method for selectively silencing neurons that produce serotonin.

The group began with a molecule genetically engineered by Bryan Roth and his colleagues at the University of North Carolina School of Medicine. Using a method that Dymecki's group had developed and optimized over the years called "intersectional genetics," they incorporated this molecule, a receptor, into the serotonin-producing brain cells in mice. As a result, the mice naturally generated this "unnatural" receptor on the surface of their serotoninergic neurons.

Receptors are key players in cellular communications, the initial recipients of chemical signals sent by other cells. Here, the researchers injected the mice with clozapine-N-oxide, a chemical compound designed to bind to and trigger the engineered receptor. Within minutes, the chemical and the foreign receptor acted together as a kind of dimmer switch, dampening the action of serotonin networks in the brains of these mice.

"This gave us the ability to selectively shut down serotonergic neuron function in the mouse brain," said Ray. "The mice remained awake, thus we could study their behavior in a normal environment."

When serotonergic neuron activity was diminished, the mice lost their capacity to maintain body temperature, and their temperatures plummeted to that of their surrounding environment.

Also, the ability of the mice to physiologically respond to elevations in carbon dioxide levels—typically in the form of heavy, rapid breathing to rid the body of excessive carbon dioxide buildup before it might reach dangerous levels—was roughly half that of normal mice when serotonergic neuron activity was low.

"What is particularly powerful to note is that we were able to study the mice both before and after we switched off the serotonergic neurons," said Ray. "We were able to demonstrate that prior to activating this foreign receptor switch—that is prior to silencing the serotonin neurons—the mice responded normally to temperature and carbon dioxide challenges."

The researchers believe this work may help us better understand the mechanisms underlying SIDS in humans.

Recent findings from the lab of Hannah Kinney at Children's Hospital Boston suggest that SIDS babies may have a deficiency of serotonin in circuits in the brainstem. Such deficiencies may lead directly to abnormal responses to elevated levels of carbon dioxide, such as when a baby rebreathes exhaled stale gases with high carbon dioxide levels while lying facedown.

"These infants may be vulnerable to sudden death due to impaired serotonin function in brainstem circuits important for protective responses to life threatening challenges, such as increased levels of carbon dioxide," said Dymecki. "What's more, a SIDS-vulnerable infant may be less equipped to maintain a normal body temperature."

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UC Riverside Chemists Transform Acids İnto Bases

Chemists at the University of California, Riverside have accomplished in the lab what until now was considered impossible: transform a family of compounds which are acids into bases. As our chemistry lab sessions have taught us, acids are substances that taste sour and react with metals and bases (bases are the chemical opposite of acids). For example, compounds of the element boron are acidic while nitrogen and phosphorus compounds are basic.

The research, reported in the July 29 issue of Science, makes possible a vast array of chemical reactions – such as those used in the pharmaceutical and biotechnology industries, manufacturing new materials, and research academic institutions.

"The result is totally counterintuitive," said Guy Bertrand, a distinguished professor of chemistry, who led the research. "When I presented preliminary results from this research at a conference recently, the audience was incredulous, saying this was simply unachievable. But we have achieved it. We have transformed boron compounds into nitrogen-like compounds. In other words, we have made acids behave like bases."

Bertrand's lab at UC Riverside specializes on catalysts. A catalyst is a substance – usually a metal to which ions or compounds are bound – that facilitates or allows a chemical reaction, but is neither consumed nor altered by the reaction itself. Crucial to the reaction's success, a catalyst is like the car engine enabling an uphill drive. While only about 30 metals are used to form catalysts, the binding ions or molecules, called ligands, can number in the millions, allowing for numerous catalysts. Currently, the majority of these ligands are nitrogen- or phosphorus-based.

"The trouble with using phosphorus-based catalysts is that phosphorus is toxic and it can contaminate the end products," Bertrand said. "Our work shows that it is now possible to replace phosphorus ligands in catalysts with boron ligands. And boron is not toxic. Catalysis research has advanced in small, incremental steps since the first catalytic reaction took place in 1902 in France. Our work is a quantum leap in catalysis research because a vast family of new catalysts can now be added to the mix. What kind of reactions these new boron-based catalysts are capable of facilitating is as yet unknown. What is known, though, is that they are potentially numerous."

Bertrand explained that acids cannot be used as ligands to form a catalyst. Instead, bases must be used. While all boron compounds are acids, his lab has succeeded in making these compounds behave like bases. His lab achieved the result by modifying the number of electrons in boron, with no change to the atom's nucleus.

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Rice Scientists Build Battery İn A Nanowire

The world at large runs on lithium ion batteries. New research at Rice University shows that tiny worlds may soon do the same. The Rice lab of Professor Pulickel Ajayan has packed an entire lithium ion energy storage device into a single nanowire, as reported this month in the American Chemical Society journal Nano Letters. The researchers believe their creation is as small as such devices can possibly get, and could be valuable as a rechargeable power source for new generations of nanoelectronics.

In their paper, researchers described testing two versions of their battery/supercapacitor hybrid. The first is a sandwich with nickel/tin anode, polyethylene oxide (PEO) electrolyte and polyaniline cathode layers; it was built as proof that lithium ions would move efficiently through the anode to the electrolyte and then to the supercapacitor-like cathode, which stores the ions in bulk and gives the device the ability to charge and discharge quickly.

The second packs the same capabilities into a single nanowire. The researchers built centimeter-scale arrays containing thousands of nanowire devices, each about 150 nanometers wide. A nanometer is a billionth of a meter, thousands of times smaller than a human hair.

Ajayan's team has been inching toward single-nanowire devices for years. The researchers first reported the creation of three-dimensional nanobatteries last December. In that project, they encased vertical arrays of nickel-tin nanowires in PMMA, a widely used polymer best known as Plexiglas, which served as an electrolyte and insulator. They grew the nanowires via electrodeposition in an anodized alumina template atop a copper substrate. They widened the template's pores with a simple chemical etching technique that created a gap between the wires and the alumina, and then drop-coated PMMA to encase the wires in a smooth, consistent sheath. A chemical wash removed the template and left a forest of electrolyte-encased nanowires.

In that battery, the encased nickel-tin was the anode, but the cathode had to be attached on the outside.

The new process tucks the cathode inside the nanowires, said Ajayan, a professor of mechanical engineering and materials science. In this feat of nanoengineering, the researchers used PEO as the gel-like electrolyte that stores lithium ions and also serves as an electrical insulator between nanowires in an array.

After much trial and error, they settled on an easily synthesized polymer known as polyaniline (PANI) as their cathode. Drop-coating the widened alumina pores with PEO coats the insides, encases the anodes and leaves tubes at the top into which PANI cathodes could also be drop-coated. An aluminum current collector placed on top of the array completes the circuit.

"The idea here is to fabricate nanowire energy storage devices with ultrathin separation between the electrodes," said Arava Leela Mohana Reddy, a research scientist at Rice and co-author of the paper. "This affects the electrochemical behavior of the device. Our devices could be a very useful tool to probe nanoscale phenomenon."

The team's experimental batteries are about 50 microns tall -- about the diameter of a human hair and almost invisible when viewed edge-on, Reddy said. Theoretically, the nanowire energy storage devices can be as long and wide as the templates allow, which makes them scalable.

The nanowire devices show good capacity; the researchers are fine-tuning the materials to increase their ability to repeatedly charge and discharge, which now drops off after a about 20 cycles.

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Silver Pen Has The Write Stuff For Flexible Electronics

The pen may have bested the sword long ago, but now it's challenging wires and soldering irons. University of Illinois engineers have developed a silver-inked rollerball pen capable of writing electrical circuits and interconnects on paper, wood and other surfaces. The pen is writing whole new chapters in low-cost, flexible and disposable electronics.

Led by Jennifer Lewis, the Hans Thurnauer professor of materials science and engineering at the U. of I., and Jennifer Bernhard, a professor of electrical and computer engineering, the team published its work in the journal Advanced Materials.

"Pen-based printing allows one to construct electronic devices 'on-the-fly,' " said Lewis, the director of the Frederick Seitz Materials Research Laboratory at the U. of I. "This is an important step toward enabling desktop manufacturing (or personal fabrication) using very low cost, ubiquitous printing tools."

While it looks like a typical silver-colored rollerball pen, this pen's ink is a solution of real silver. After writing, the liquid in the ink dries to leave conductive silver pathways – in essence, paper-mounted wires. The ink maintains its conductivity through multiple bends and folds of the paper, enabling devices with great flexibility and conformability.

Metallic inks have been used in approaches using inkjet printers to fabricate electronic devices, but the pen offers freedom and flexibility to apply ink directly to paper or other rough surfaces instantly, at low cost and without programming.

"The key advantage of the pen is that the costly printers and printheads typically required for inkjet or other printing approaches are replaced with an inexpensive, hand-held writing tool," said Lewis, who is also affiliated with the Beckman Institute for Advanced Science and Technology.

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Southampton Engineers Fly The World's First 'Printed' Aircraft

Engineers at the University of Southampton have designed and flown the world's first 'printed' aircraft, which could revolutionise the economics of aircraft design. The SULSA (Southampton University Laser Sintered Aircraft) plane is an unmanned air vehicle (UAV) whose entire structure has been printed, including wings, integral control surfaces and access hatches. It was printed on an EOS EOSINT P730 nylon laser sintering machine, which fabricates plastic or metal objects, building up the item layer by layer.

No fasteners were used and all equipment was attached using 'snap fit' techniques so that the entire aircraft can be put together without tools in minutes.

The electric-powered aircraft, with a 2-metres wingspan, has a top speed of nearly 100 miles per hour, but when in cruise mode is almost silent. The aircraft is also equipped with a miniature autopilot developed by Dr Matt Bennett, one of the members of the team.

Laser sintering allows the designer to create shapes and structures that would normally involve costly traditional manufacturing techniques. This technology allows a highly-tailored aircraft to be developed from concept to first flight in days. Using conventional materials and manufacturing techniques, such as composites, this would normally take months. Furthermore, because no tooling is required for manufacture, radical changes to the shape and scale of the aircraft can be made with no extra cost.

This project has been led by Professors Andy Keane and Jim Scanlan from the University's Computational Engineering and Design Research group.

Professor Scanlon says: "The flexibility of the laser sintering process allows the design team to re-visit historical techniques and ideas that would have been prohibitively expensive using conventional manufacturing. One of these ideas involves the use of a Geodetic structure. This type of structure was initially developed by Barnes Wallis and famously used on the Vickers Wellington bomber which first flew in 1936. This form of structure is very stiff and lightweight, but very complex. If it was manufactured conventionally it would require a large number of individually tailored parts that would have to be bonded or fastened at great expense."

Professor Keane adds: "Another design benefit that laser sintering provides is the use of an elliptical wing planform. Aerodynamicists have, for decades, known that elliptical wings offer drag benefits. The Spitfire wing was recognised as an extremely efficient design but it was notoriously difficult and expensive to manufacture. Again laser sintering removes the manufacturing constraint associated with shape complexity and in the SULSA aircraft there is no cost penalty in using an elliptical shape."

SULSA is part of the EPSRC-funded DECODE project, which is employing the use of leading edge manufacturing techniques, such as laser sintering, to demonstrate their use in the design of UAVs.

The University of Southampton has been at the forefront of UAV development since the early 1990s, when work began on the Autosub programme at its waterfront campus at the National Oceanography Centre, Southampton. A battery powered submarine travelled under sea ice in more than 300 voyages to map the North Sea, and assess herring stocks.

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An Unexpected Clue To Thermopower Efficiency

Scientists at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and their colleagues have discovered a new relation among electric and magnetic fields and differences in temperature, which may lead to more efficient thermoelectric devices that convert heat into electricity or electricity into heat. "In the search for new sources of energy, thermopower – the ability to convert temperature differences directly into electricity without wasteful intervening steps – is tremendously promising," says Junqiao Wu of Berkeley Lab's Materials Sciences Division (MSD), who led the research team. Wu is also a professor of materials science and engineering at the University of California at Berkeley. "But the new effect we've discovered has been overlooked by the thermopower community, and can greatly affect the efficiency of thermopower and other devices."

Wu and his colleagues found that temperature gradients in semiconductors, when one side of the device is hotter than the opposite side, can produce electronic vortices – whirlpools of electric current – and can, at the same time, create magnetic fields at right angles to both the plane of the swirling electric currents and the direction of the heat gradient. The researchers report their results in Physical Review B.

Wu says, "There are four well-known effects that relate thermal, electric, and magnetic fields" – for example, the familiar Hall effect, which describes the voltage difference across an electric conductor in a perpendicular magnetic field – "but in all these effects the magnetic field is an input, not an outcome. We asked, 'Why not use the electric field and the heat gradient as inputs and try to generate a magnetic field?'"

To test the possibilities, the researchers modeled a practical device made of two layers of silicon: a thin, negatively doped layer (N-type) with an excess of electrons and a thicker, positively doped layer (P-type) with an excess of holes, which are electron absences that behave as positively charged particles.

At the junction where the oppositely doped silicon layers meet, a third kind of layer called a P-N junction forms, not physical but electronic: electrons from the N-type layer diffuse across the physical boundary into the P-type layer while holes move in the opposite direction, forming a depletion layer where charges are "dried out".

Given the high density of mobile electrons at the surface of the N-type layer and the high density of mobile holes at the surface of the P-type layer, but few mobile charges in the depletion layer, the electric field is strongest near the junction. This deep layer has profound effects, when a heat gradient is applied to the joined silicon layers.

Wake up and smell the champagne

"There are three ways charges can move – three kinds of currents," says Wu. "One is the diffusion current, in which particles move from denser areas to less dense areas. This has nothing to do with charge. Think of a bottle of champagne. I pop the cork, and a little while later you can smell the champagne, because the molecules diffuse from their dense concentration in the bottle into the air."

The second kind of current is called drift current. "If there's a draft in the room moving toward you, you may smell the champagne a little earlier, or if it's moving away from you, a little later," Wu explains. "In an electronic device, a drift current is caused by the voltage bias, the electric field."

Says Wu, "So in an electronic device we have diffusion current away from the dense charge areas, and drift current due to the electric field, and now we add a third, the thermoelectric current, which is another form of drift current in which charge carriers move from the hotter end of the device to the cooler end."

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New Study Outlines Economic and Environmental Benefits To Reducing Nitrogen Pollution

A new study co-authored by Columbia Engineering professor Kartik Chandran and recently published in the journal, Environmental Science & Technology, shows that reducing nitrogen pollution generated by wastewater treatment plants can come with "sizable" economic benefits, as well as the expected benefits for the environment. Chandran was one of five scientists from around the U.S. who worked on the study, along with James Wang of NOAA's Air Resources Laboratory and formerly of Environmental Defense Fund (EDF); Steve Hamburg, Chief Scientist for EDF; Donald Pryor of Brown University; and Glen Daigger of CH2M Hill, a global environmental engineering firm based in Englewood, Colorado.

The study found that adding available technology to the existing infrastructure at a common type of wastewater treatment plant could create a trifecta of reductions in aquatic nitrogen pollution, greenhouse gas pollution, and energy usage. It also found that creating an emissions crediting system for the wastewater treatment sector could make the addition of new technologies much more affordable.

"As wastewater permits on wastewater treatment plants become more and more restrictive, the resultant increased capital and operating costs can pose quite a burden to utilities and municipalities," said Chandran, associate professor of earth and environmental engineering. "Our study shows that, if the reduced emissions associated with well-designed and operated biological nitrogen removal operations can be used to earn CO2 credits, then this could be a big benefit both for the utilities from a cost perspective and for the environment from water quality and air quality perspectives."

The majority of wastewater treatment plants already have systems to reduce ammonia levels in effluent, but pay relatively little attention to overall nitrogen pollution reduction, especially in the form of nitrous oxide (N2O), a potent greenhouse gas. Using emissions credits to address the problem could create an economic incentive of up to $600 million per year for U.S. plants to reduce nitrogen pollution, with the added benefit of up to $100 million per year in electricity savings if they do so.

"Recent N2O monitoring studies conducted by Columbia Engineering and research groups across the globe have found that meeting wastewater treatment objectives actually decreases biogenic N2O emissions," added Chandran. "So designing and adopting better process technologies for improving water quality could actually have a significant impact on reduced N2O emissions."

"Our study shows that there's a win-win-win situation out there waiting to be realized," said James Wang, the chief author of the paper. "The creation of an emissions trading market could provide the needed incentive for wastewater treatment plants to adopt technologies that would reduce climate pollution, help clean up our waterways, and even save energy and money."

Chandran's research focuses primarily on biological nitrogen removal from wastewater, sustainable water sanitation and hygiene (WASH), and developing new technologies for resource recovery and reuse from waste. His team recently created the first protocol to measure nitrous oxide (a greenhouse gas 300 times more potent than CO2). Using the protocol, his Columbia Engineering group developed the first nationwide database of N2O emissions from wastewater treatment plants. The database has now been adopted by the U.S. Environmental Protection Agency as the standard to estimate N2O emissions from wastewater treatment plants. Chandran is also working towards developing and implementing "energy-positive" wastewater treatment technologies that will produce energy rather than consume it at some of the largest wastewater utilities in the U.S.

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Put The Brakes On Using Your Brain Power

German researchers have used drivers' brain signals, for the first time, to assist in braking, providing much quicker reaction times and a potential solution to the thousands of car accidents that are caused by human error. Using electroencephalography (EEG) – a technique that attaches electrodes to the scalp –, the researchers demonstrated that the mind-reading system, accompanied with modern traffic sensors, could detect a driver's intention to break 130 milliseconds faster than a normal brake pedal response.

Driving at 100km/h, this amounts to reducing the braking distance by 3.66 meters - the full length of a compact car or the potential margin between causing and avoiding accidents.

The study, published today, 29 July 2011, in IOP Publishing's Journal of Neural Engineering, identified the parts of the brain that are most active when braking and used a driving simulator to demonstrate the viability of mind-reading assisted driving.

A detailed video of one of the subjects driving the simulator can be seen here.

As well as EEG, the researchers, from the Berlin Institute for Technology, also chose to examine myoelectric (EMG) activity which is caused by muscle tension in the lower leg and can be used to detect leg motion before it actually moves to the brake pedal.

Whilst sat among conventional driving controls, the study's 18 participants were asked to drive a car that was displayed on a screen in front of them whilst a series of electrodes were attached to their scalp to measure brain activity.

They were asked to stay within a 20 metre distance of a computer-controlled lead vehicle along a road that contained sharp curves and dense oncoming traffic, to recreate real driving conditions, whilst maintaining a speed of 100km/h.

At random intervals, emergency braking situations were triggered by the rapid braking of the lead vehicle in front, accompanied by the flashing of its braking lights.

At this point, when the subjects reacted, the data was collected from the EEG and EMG. For comparison, the researchers also recorded information on the time it took to release the gas pedal and press the brake pedal, the deceleration of both vehicles and the distance between the two vehicles.

Using the initial EEG recordings, the researchers were able to determine what parts of the brain are most sensitive in a braking scenario and therefore tweak the detection system accordingly.

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Researchers Target,Switch Off Serotonin-producing Neurons İn Mice

Researchers have developed a toolkit that enables them to turn off targeted cell populations while leaving others unaffected. Led by Susan Dymecki, a professor of genetics at Harvard Medical School, the group focused on serotonin-producing neurons, observing how mice behave in a normal environment when suddenly their serotonin neurons are turned down. While their findings affirm earlier studies, the researchers used a technique that is non-invasive and does not require anesthesia, surgeries, or knocking out a gene—each of which can cause problems when interpreting results.

"By selectively and abruptly switching off the serotonin-producing cells, we can get a definite idea of what bodily functions the serotonin cells specifically control," said Dymecki. "These findings and the new tools in neuroscience that it brings to the table will help us understand the role of serotonergic neurons in many human disorders."

One such disorder particularly relevant to these findings is Sudden Infant Death Syndrome, or SIDS.

These findings will appear in the July 29 edition of the journal Science.

The mammalian brain contains multiple chemical messengers, called neurotransmitters, which transfer information between nerve cells in order to regulate basic behaviors and functions like walking, eating, and sleeping. Serotonin is a major brain neurotransmitter produced solely by cells in the lower brain, or brainstem. Cells that make serotonin can convey information to large numbers of neurons distributed throughout the brain and can affect behavior as complex as mood.

In order to better understand how these serotonin-producing cells in the brain relate to basic physiology, Russell Ray and Rachael Brust, a postdoctoral researcher and a graduate student in Dymecki's lab, along with Jun Chul Kim, a prior postdoctoral fellow in Dymecki's lab who is now at the University of Toronto, and Andrea Corcoran, a postdoctoral researcher in the lab of Eugene Nattie at Dartmouth Medical School along with George Richerson, a professor of neurology at the University of Iowa, developed and characterized a method for selectively silencing neurons that produce serotonin.

The group began with a molecule genetically engineered by Bryan Roth and his colleagues at the University of North Carolina School of Medicine. Using a method that Dymecki's group had developed and optimized over the years called "intersectional genetics," they incorporated this molecule, a receptor, into the serotonin-producing brain cells in mice. As a result, the mice naturally generated this "unnatural" receptor on the surface of their serotoninergic neurons.

Receptors are key players in cellular communications, the initial recipients of chemical signals sent by other cells. Here, the researchers injected the mice with clozapine-N-oxide, a chemical compound designed to bind to and trigger the engineered receptor. Within minutes, the chemical and the foreign receptor acted together as a kind of dimmer switch, dampening the action of serotonin networks in the brains of these mice.

"This gave us the ability to selectively shut down serotonergic neuron function in the mouse brain," said Ray. "The mice remained awake, thus we could study their behavior in a normal environment."

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TPS Carries Out The Architectural Design For New Air Traffic Control Tower At Muscat International Airport in Oman

It is expected that the new air traffic control tower at Muscat International Airport, Sultanate of Oman, will become an international symbol for Oman. Standing at just less than 100 metres in height, it will be the tallest occupied building in the country’s capital, Muscat, when it opens. It is located to the south of the new passenger terminal west pier and linked to the terminal building by a glazed bridge link.

The project - 11 new buildings in total with associated external works - is procured under a design & build contract and is part of a wider redevelopment scheduled for completion in 2014, which will allow the airport to handle 12 million visitors per year.

TPS has started work on the new development , which will include an iconic air traffic control tower, an air transport management complex, a contingency and training centre, plus fire and sea rescue facilities.

The slenderness of the structure subjected to variable wind forces will cause it to sway. TPS, the principal consultant to the project, is carrying out all the architectural design and, for the ATC, has brought in Mott Macdonald and RWDI as part of the team to analyse the structural characteristics of the tower, and also to re-evaluate the wind tunnel test data that was previously undertaken. This is to enable detailed design for all the structural elements and also determine the optimum performance parameters for a suitable damping mechanism.

Working with the Oman-based construction company Carillion Alawi, TPS and its sub-consultants are overseeing their design being implemented during the construction process which will include the installation of a Tuned Mass Damper, or a suitable alternative, to harmonise the predicted oscillations with the structure’s natural frequency, allowing the air traffic controllers to work normally at this height. The tower will provide the essential air traffic control services and has been designed to satisfy all the operational and regulatory requirements with a permanent height dispensation.

The Air Transport Management Complex (ATM) is, in reality, three buildings linked by a central hub housing the three-storey entrance foyer with lifts and stairs to all three levels. The main function of the ATM is the Area Control Centre which is accommodated in the northernmost wing, in a voluminous, extensively serviced, double-storey space, highly insulated from external visual and audible distractions. An obscured glazed gallery provides visiting parties of dignitaries, students, etc with the opportunity to observe operations without distracting the air traffic controllers. The East and West wings accommodate a variety of supporting functions including offices, laboratories, classrooms, studios, workshops, and staff welfare facilities including pantries, gymnasia, dining area, and prayer rooms, plus a meteorological department with a studio from which national weather forecasts are intended to be broadcast.

The Contingency and Training Centre is located adjacent to the ATM Complex and accommodates the operational and technical training facilities comprising classrooms, offices, meeting rooms, simulators
and other airport related support functions. A 100-person capacity auditorium forms a key facility to the C&T Centre and visual hub.

The Crash Fire Rescue facility is located on the south side of the northern runway to facilitate the required rapid emergency incident response times. The building design and fire fighting equipment will help to ensure that the current ICAO standards for fire safety are achieved and maintained.

The airport development, funded by the country’s Ministry of Transport and Communication on behalf of the Government of the Sultanate of Oman, is part of a long term strategy to diversify Oman’s economy away from oil, boosting business, leisure tourism and supporting the national airline Oman Air.

Piling and earthworks for the project started this April, with all buildings in this part of the scheme scheduled to be finished by the end of October 2012.

Regional Director of TPS, Hanif Macci, said: “The key challenges for us are to develop designs in parallel, whilst meeting the different project objectives to a tight timescale. We also have to manage design interfaces for the timely flow of information with designers of other contracts for the airport development.”

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My House Online Resource Offers A Comprehensive Reference Point For Anyone Looking To Use Marley Eternit's Cladding and Roofing Products

Marley Eternit is a provider of cladding and roofing solutions to the construction industry. Products include all types of concrete and clay tiles, double and single lap slates, decorative cladding, profiled sheeting and a range of building boards. ‘My House’ is a new self build and home improvement section on Marley Eternit's main website, which provides both informative and practical information about a range of cladding and roofing solutions.

The dedicated area features a range of products most frequently chosen by self builders and home improvers, such as Cedral Weatherboard, Clay Roof Tiles and Fibre Cement Slates, along with Profiled Sheeting.

Designed around customer needs, the user-friendly site includes product benefits, easy to follow step by step installation guides, case studies and brochure downloads - offering self builders and home improvers all the information they need to select the best cladding and roofing solution for their project.

Case studies shown on the site provide real examples of the benefits of selecting Marley Eternit products. The projects showcased range from a beautiful self build house in the Scottish highlands to a stunning beach front refurbishment property on the South coast, all using cladding and roofing solutions from Marley Eternit.

Innovative features on ‘My House’ include a new calculation tool that quickly calculates the quantity of Cedral Weatherboard required for a project and a magnifying glass tool that allows visitors to ‘Take a Closer Look’ at the colours and finishes available.

Completing the customer-driven approach is an easy-to-use sample request facility and stockist and contractor information, providing a complete no-hassle solution.

“My House’ offers a comprehensive reference point for anyone looking to use our cladding and roofing products, to create a durable, sustainable and visually engaging property,” said Diana Bullock, Campaign Manager at Marley Eternit. “My House’ includes information for self builders and home improvers, in a clear and easy-to-use format, and also includes details on installation and specific case study examples – to help them create their ideal home.”

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TCHG Uses H+H Aircrete Blocks For Low Carbon Prototype Home İn Kent

Town & Country Housing Group (TCHG) have constructed a low carbon prototype home in Kent. This prototype will act as a test bed for building to level 5 of the Code for Sustainable Homes.

The home is designed to fit in with others in the area and cost £205,000 to build (including the renewable energy technology that was being trialled), on land already owned by the housing group. Residents Joanna and Thomas Clarke and their son Finley have been living in the home since July last year.

In the process they used the H+H Thin Joint system with large format Jumbo Bloks. The house is designed to be as energy efficient as possible, resulting in low running costs for the occupants. Essential to this is a ‘fabric first’ approach whereby the building structure is constructed to be extremely airtight and thermally efficient to reduce heat loss to a minimum. Using Thin Jointed aircrete significantly contributed to this way of building.

Paul White, TCHG Design & Quality Manager commented: “We used H+H aircrete blocks for the project for their high recycled content as well as their inherently high insulative qualities. This allowed us to construct thinner external walls than alternatives on a tight site whilst still achieving a low U-value.”

He added: “Using the Thin Joint system with the Rå Build method is a good option because speed of construction means the inner shell can be made weather tight extremely quickly, faster than using traditional masonry techniques thus preventing the structure becoming damp in wet weather and allowing other trades to start internal work earlier. Furthermore, the system offers some thermal mass (to help regulate the temperature in hot weather) over and above standard timber frame options.”

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Tensartech TW3 Blocks Used To Construct Earth Retaining Wall İn SheffieldTensartech TW3 Blocks Used To Construct Earth Retaining Wall İn Sheffield

The Spital Hill location in Sheffield had originally been cut into by Victorian engineers who left a massive, buttressed and arched masonry retaining wall. Sheffield City Council was reluctant to allow main contractor Bowman & Kirkland (East Midlands) to disturb the wall, both for preservation and because there were no records of what lay behind it.

The store is constructed around a steel frame, with the first floor and main shopping area at the upper ground level, and the basement, car park and store front entrance below. The ground conditions at the low level comprise weak alluvium deposited by the River Don, variable in consistency and up to 18 metres deep in places.

To build up the site in front of the original wall, without loading it, a new, 160 metres long retaining wall was required, up to ten metres high, over a six to ten metres wide platform. The platform also supports an access road and the store front entrance.

Construction of the basement car park and foundations for a superstore, on the steep site in Sheffield, meant building over and in front of an existing Victorian wall which could not be structurally loaded. Tensar International designed an innovative Tensartech wall solution over a TriAx® foundation mattress to overcome poor load bearing soil conditions, which also helped to reduce the project’s CO2 footprint.

A standard reinforced concrete wall and base, requiring extensive formwork, would have imposed a high carbon footprint on the project, especially with the number concrete deliveries required to site.

Instead, the Tensar Technical Department’s design used a ground improvement solution founded on stone trenches cut into the alluvium and filled with compacted crushed concrete slabs sourced from the site. To distribute the imposed structural loads, the trenches were overlaid with a reinforced soil mattress constructed from layers of compacted crushed stone interlocked with TriAx® geogrid. The resultant stiff, mechanically stabilised platform mitigates against the potential effects of differential settlement.

On the platform and adjacent to the masonry wall, a Tensartech TW3 retaining wall was constructed. This technique comprises uniaxial geogrids layered within locally sourced 6I IBAA Incinerator Bottom Ash Aggregate granular fill and fastened to a split face, TW3 concrete modular blocks with Tensar’s unique polymer connector.

The result is a self supporting reinforced soil structure, which imparts no lateral thrust on the old wall behind. The split face concrete blocks provide an aesthetically attractive masonry appearance to the new wall.

Tensar geogrid solutions can be installed with minimal heavy plant, are rapid to install and are immediately load bearing, without requiring curing time. Tensartech wall and slope technology is BBA certificated.

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Stamping Out Low Cost Nanodevices

A simple technique for stamping patterns invisible to the human eye onto a special class of nanomaterials provides a new, cost-effective way to produce novel devices in areas ranging from drug delivery to solar cells. The technique was developed by Vanderbilt University engineers and described in the cover article of the May issue of the journal Nano Letters.

The new method works with materials that are riddled with tiny voids that give them unique optical, electrical, chemical and mechanical properties. Imagine a stiff, sponge-like material filled with holes that are too small to see without a special microscope.

For a number of years, scientists have been investigating the use of these materials – called porous nanomaterials – for a wide range of applications including drug delivery, chemical and biological sensors, solar cells and battery electrodes. There are nanoporous forms of gold, silicon, alumina, and titanium oxide, among others.

Simple stamping

A major obstacle to using the materials has been the complexity and expense of the processing required to make them into devices.

Now, Associate Professor of Electrical Engineering Sharon M. Weiss and her colleagues have developed a rapid, low-cost imprinting process that can stamp out a variety of nanodevices from these intriguing materials.

"It's amazing how easy it is. We made our first imprint using a regular tabletop vise," Weiss said. "And the resolution is surprisingly good."

The traditional strategies used for making devices out of nanoporous materials are based on the process used to make computer chips. This must be done in a special clean room and involves painting the surface with a special material called a resist, exposing it to ultraviolet light or scanning the surface with an electron beam to create the desired pattern and then applying a series of chemical treatments to either engrave the surface or lay down new material. The more complicated the pattern, the longer it takes to make.

About two years ago, Weiss got the idea of creating pre-mastered stamps using the complex process and then using the stamps to create the devices. Weiss calls the new approach direct imprinting of porous substrates (DIPS). DIPS can create a device in less than a minute, regardless of its complexity. So far, her group reports that it has used master stamps more than 20 times without any signs of deterioration.

Process can produce nanoscale patterns

The smallest pattern that Weiss and her colleagues have made to date has features of only a few tens of nanometers, which is about the size of a single fatty acid molecule. They have also succeeded in imprinting the smallest pattern yet reported in nanoporous gold, one with 70-nanometer features.

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Nanoscale Waveguide For Future Photonics

The creation of a new quasiparticle called the "hybrid plasmon polariton" may throw open the doors to integrated photonic circuits and optical computing for the 21st century. Researchers with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) have demonstrated the first true nanoscale waveguides for next generation on-chip optical communication systems. "We have directly demonstrated the nanoscale waveguiding of light at visible and near infrared frequencies in a metal-insulator-semiconductor device featuring low loss and broadband operation," says Xiang Zhang, the leader of this research. "The novel mode design of our nanoscale waveguide holds great potential for nanoscale photonic applications, such as intra-chip optical communication, signal modulation, nanoscale lasers and bio-medical sensing."

Zhang, a principal investigator with Berkeley Lab's Materials Sciences Division and director of the University of California at Berkeley's Nano-scale Science and Engineering Center (SINAM), is the corresponding author of a paper published by Nature Communications that describes this work titled "Experimental Demonstration of Low-Loss Optical Waveguiding at Deep Sub-wavelength Scales." Co-authoring the paper with Zhang were Volker Sorger, Ziliang Ye, Rupert Oulton, Yuan Wang, Guy Bartal and Xiaobo Yin.

In this paper, Zhang and his co-authors describe the use of the hybrid plasmon polariton, a quasi-particle they conceptualized and created, in a nanoscale waveguide system that is capable of shepherding light waves along a metal-dielectric nanostructure interface over sufficient distances for the routing of optical communication signals in photonic devices. The key is the insertion of a thin low-dielectric layer between the metal and a semiconductor strip.

"We reveal mode sizes down to 50-by-60 square nanometers using Near-field scanning optical microscopy (NSOM) at optical wavelengths," says Volker Sorger a graduate student in Zhang's research group and one of the two lead authors on the Nature Communications paper. "The propagation lengths were 10 times the vacuum wavelength of visible light and 20 times that of near infrared."

The high-technology world is eagerly anticipating the replacement of today's electronic circuits in microprocessors and other devices with circuits based on the transmission of light and other forms of electromagnetic waves. Photonic technology, or "photonics," promises to be superfast and ultrasensitive in comparison to electronic technology.

"To meet the ever-growing demand for higher data bandwidth and lower power consumption, we need to reduce the energy required to create, transmit and detect each bit of information," says Sorger. "This requires reducing physical photonic component sizes down beyond the diffraction limit of light while still providing integrated functionality."

Until recently, the size and performance of photonic devices was constrained by the interference that arises between closely spaced light waves. This diffraction limit results in weak photonic-electronic interactions that can only be avoided through the use of devices much larger in size than today's electronic circuits. A breakthrough came with the discovery that it is possible to couple photons with electrons by squeezing light waves through the interface between a metal/dielectric nanostructure whose dimensions are smaller than half the wavelengths of the incident photons in free space.

Directing waves of light across the surface of a metal nanostructure generates electronic surface waves – called plasmons - that roll through the metal's conduction electrons (those loosely attached to molecules and atoms). The resulting interaction between plasmons and photons creates a quasi-particle called a surface plasmon polariton(SPP) that can serve as a carrier of information. Hopes were high for SPPs in nanoscale photonic devices because their wavelengths can be scaled down below the diffraction limit, but problems arose because any light signal loses strength as it passes through the metal portion of a metal-dielectric interface.

"Until now, the direct experimental demonstration of low-loss propagation of deep sub-wavelength optical modes was not realized due to the huge propagation loss in the optical mode that resulted from the electromagnetic field being pushed into the metal," Zhang says. "With this trade-off between optical confinement and metallic losses, the use of plasmonics for integrated photonics, in particular for optical interconnects, has remained uncertain."

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Randomness Rules İn Turbulent Flows

It seems perfectly natural to expect that two motorists who depart from the same location and follow the same directions will end up at the same destination. But according to a Johns Hopkins University mathematical physicist, this is not true when the "directions" are provided by a turbulent fluid flow, such as you find in a churning river or stream. Verifying earlier theoretical predictions, Gregory Eyink's computer experiments reveal that, in principle, two identical small beads dropped into the same turbulent flow at precisely the same starting location will end up at different – and entirely random – destinations. "This result is as astonishing and unexpected as if I told you that I fired a gun aimed at precisely the same point on a target but the bullet went in a completely different direction each and every time. It's surprising because, even though the beads are exactly the same and the flow of water is exactly the same, the result is different," said Eyink, professor of applied mathematics and statistics at The Whiting School of Engineering. "It is crucial here that the flow is turbulent — as in whitewater rapids or a roiling volcanic plume — and not smooth, regular flow as in a quiet-running stream."

An article about the phenomenon appears in a recent issue of Physical Review E and is available online here http://link.aps.org/doi/10.1103/PhysRevE.83.056405

To conduct his study, Eyink used a virtual "stream" that is part of an online public database of turbulent flow created with Whiting School colleagues Charles Meneveau and Randal Burns, as well as with physicist Alexander Szalay of the Krieger School of Arts and Sciences. Into this "stream" Eyink tossed virtual "particles" at precisely the same point and let them drift within the fluid. The researcher then randomly "kicked" each of the particles as they moved along, with different "kicks" at different points along the way. The particles, as one would expect when subjected to different "kicks," followed different paths.

"But here's the surprising thing," Eyink explained. "As the kicks got weaker and weaker, the particles still followed random – and different – paths. In the end, the computer experiment seemed to show that the particles would follow different paths even if the kicks vanished completely."

This phenomenon is called "spontaneous stochasticity," which basically means that objects placed in a turbulent flow – even objects that are identical and which are dropped into the same spot – will end up in different places.

"Thus, we know that 'God plays dice' not only with subatomic particles, but also with everyday particles like soot or dust carried by a turbulent fluid," Eyink said.

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Researchers Cut Machinery Fuel Consumption By Half

Researchers at Aalto University in Finland have found a way to cut the amount of fuel consumed by non-road mobile machinery by half. This new technology captures energy, which up to now has been lost by the machinery when working, and uses it instead of fuel. The fuel consumption of construction and mining machines, agricultural machines and material handling machines is reduced significantly. − These heavy duty machines are operated for long periods of time, so by the end of the day emissions and fuel consumption have added up. Being able to target them is a significant improvement, says Professor Jussi Suomela, who is in charge of the project at Aalto University's HybLab research network in Finland.

The researchers have added an electric power transmission system into the machines. The machines then become hybrids with both combustion and electric engines. Similar technology has already proven successful in personal cars; however, hybrid cars only capture energy from wheels during deceleration, whereas work machines create most of the extra energy during work tasks. This energy has not been captured until now.

The researchers at the Finnish Aalto University are now analyzing the work cycles of different types of machinery in order to find out which work tasks allow energy to be captured. Deceleration and lowering a load are typical examples. This technology enables short-term energy storage, making it possible to store energy for later use during a peak in power demand. The electric transmission generates other side benefits such as better controllability, operator comfort, efficiency and more freedom in the machine structure.

The goal is to reduce fuel consumption and carbon dioxide emissions. Another benefit of hybridization is that it leads to lower operation costs as well. With electric power transmission, the machines may even be connected to normal wall sockets.

− Electricity from the power grid is very cost-efficient and creates no local emissions. If the machine can be plugged in, that is usually the best option. The future is likely to make fuel cells available, too, says Suomela. And the benefits do not stop here: the machines are even able to release stored electrical energy back into the grid.

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Study Finds Fire Stations Contaminated With MRSA

MRSA transmission may be occurring in fire stations, according to a study published in the June issue of the American Journal of Infection Control, the official publication of APIC – the Association for Professionals in Infection Control and Epidemiology. The purpose of the study, conducted by investigators from the University of Washington School of Public Health, was to determine potential areas within the fire stations that were contaminated with methicillin-resistant Staphylococcus aureus (MRSA) and characterize the isolates to determine if they were related to hospital (HA-MRSA) and/or community (CA-MRSA) strains.

"This is the first study to molecularly characterize MRSA isolates from fire station environmental surfaces and the first study to sample both fire station surfaces and personnel as well as one of the first studies to characterize non-health care environmental MRSA," commented lead investigator Marilyn C. Roberts, PhD, University of Washington School of Public Health.

Researchers assessed nine different areas in two fire stations that included 1) medic trucks; 2) fire trucks and fire engines; 3) outer fire gear; 4) garages; 5) kitchens; 6) bathrooms; 7) bedrooms; 8) gyms; and 9) other areas. After the first sampling, an educational program was conducted at each station, and hand sanitizers were installed. A second set of samples was collected 7-9 months later at the same two stations. During the second sampling, nasal samples were obtained from 40 healthy fire personnel from 13 stations to evaluate MRSA carriage.

A total of 1,064 samples were collected, 600 in the first sampling and 464 in the second. Each sample was analyzed for MRSA, staphylococci that were not S. aureus but were resistant to methicillin (labeled methicillin-resistant coagulase negative Staphylococcus spp. [MRCoNS]), and staphylococci that were not methicillin resistant (labeled as coagulase negative Staphylococcus spp. [CoNS]).

At the first sampling, 26 (4.3%) of the 600 surface samples were MRSA positive, with MRSA positive samples found in all nine areas sampled. The most common area for MRSA contamination was the medic trucks with 13 (50%), the kitchens with 3 (11.5%) and other areas such as computer keyboards and computer desks with 2 (7.7%).

At the second sampling, 18 (3.9%) of the 464 surface samples were MRSA positive, with MRSA positive samples again found in all nine areas sampled. The kitchen and outer gear both had 4 (22%) MRSA positive samples, while the medic truck had 3 (16.6%), other areas had 1-2 MRSA positive samples each. Two samples contained a strain of MRSA (MRSA SCCmec type II), which is commonly found in hospitals, and were isolated from the fire truck/engine and garage areas.

Thirty percent of the nasal cultures were positive for MRSA (9 samples) or S. aureus (3 samples). The majority (58%) of the nasal MRSA and S. aureus were genetically related to environmental surface isolates suggesting transmission between personnel and the environmental surfaces may be occurring.

Investigators conclude that "Fire personnel interact with both hospital and community population as part of their job and thus have the potential for exposure to MRSA from both sources…MRSA SCCmec type II isolates, commonly found in the hospital, were also identified in the study, demonstrated that both community- and hospital-like MRSA can contaminate the fire station surfaces. The isolation of the same strain in the fire apparatuses and garage as well as the living quarters suggests that the transmission of MRSA may be occurring between these two areas…Clearly more research is needed to determine if the current findings are representative of fire stations surfaces and personnel throughout the country."

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Material Created At Purdue Lets Electrons 'Dance' and Form New State

A team of Purdue University researchers is among a small group in the world that has successfully created ultrapure material that captures new states of matter and could have applications in high-speed quantum computing. The material, gallium arsenide, is used to observe states in which electrons no longer obey the laws of single-particle physics, but instead are governed by their mutual interactions.

Michael Manfra, the William F. and Patty J. Miller Associate Professor of Physics who leads the group, said the work provides new insights into fundamental physics.

"These exotic states are beyond the standard models of solid-state physics and are at the frontier of what we understand and what we don't understand," said Manfra, who also is an associate professor of both materials engineering and electrical and computer engineering. "They don't exist in most standard materials, but only under special conditions in ultrapure gallium arsenide semiconductor crystals."

Quantum computing is based on using the quantum mechanical behavior of electrons to create a new way to store and process information that is faster, more powerful and more efficient than classical computing. It taps into the ability of these particles to be put into a correlated state in which a change applied to one particle is instantly reflected by the others. If these processes can be controlled, they could be used to create parallel processing to perform calculations that are impossible on classical computers.

"If we could harness this electron behavior in a semiconductor, it may be a viable approach to building a quantum computer," Manfra said. "Of course this work is just in its very early stages, and although it is very relevant to quantum computation, we are a long way off from that. Foremost at this point is the chance to glimpse unexplained physical phenomena and new particles."

Manfra and his research team designed and built equipment called a high-mobility gallium-arsenide molecular beam epitaxy system, or MBE, that is housed at Purdue's Birck Nanotechnology Center. The equipment makes ultrapure semiconductor materials with atomic-layer precision. The material is a perfectly aligned lattice of gallium and arsenic atoms that can capture electrons on a two-dimensional plane, eliminating their ability to move up and down and limiting their movement to front-to-back and side-to-side.

"We are basically capturing the electrons within microscopic wells and forcing them to interact only with each other," he said. "The material must be very pure to accomplish this. Any impurities that made their way in would cause the electrons to scatter and ruin the fragile correlated state."

The electrons also need to be cooled to extremely low temperatures and a magnetic field is applied to achieve the desired conditions to reach the correlated state.

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Women Who Leave The Workplace: Opting Out Or Overlooking Discrimination?

For the first time in history, the majority of Americans believe that women's job opportunities are equal to men's. For example, a 2005 Gallup poll indicated that 53 percent of Americans endorse the view that opportunities are equal, despite the fact that women still earn less than men, are underrepresented at the highest levels of many fields, and face other gender barriers such as bias against working mothers and inflexible workplaces. New research from the Kellogg School of Management at Northwestern University helps to explain why many Americans fail to see these persistent gender barriers. The research demonstrates that the common American assumption that behavior is a product of personal choice fosters the belief that opportunities are equal and that gender barriers no longer exist in today's workplace.

The study, "Opting Out or Denying Discrimination? How the Framework of Free Choice in American Society Influences Perceptions of Gender Inequality," suggests that the assumption that women "opt out" of the workforce, or have the choice between career or family, promotes the belief that individuals are in control of their fates and are unconstrained by the environment.

The study was co-authored by Nicole M. Stephens, assistant professor of management and organizations at the Kellogg School of Management, and Cynthia S. Levine, a doctoral student in the psychology department at Stanford University. It will be published in a forthcoming issue of Psychological Science, a journal of the Association for Psychological Science.

"Although we've made great strides toward gender equality in American society, significant obstacles still do, in fact, hold many women back from reaching the upper levels of their organizations," said Stephens. "In our research, we sought to determine how the very idea of 'opting out,' or making a choice to leave the workplace, may be maintaining these social and structural barriers by making it more difficult to recognize gender discrimination."

In one study, a group of stay-at-home mothers answered survey questions about how much choice they had in taking time off from their career and about their feelings of empowerment in making life plans and controlling their environment.

The participants then reviewed a set of real statistics about gender inequality in four fields – business, politics, law and science/engineering – and were asked to evaluate whether these barriers were due to bias against women or societal and workplace factors that make it difficult for women to hold these positions.

As predicted, most women explained their workplace departure as a matter of personal choice – which is reflective of the cultural understanding of choice in American society and underscores how the prevalence of choice influences behavior. These same women experienced a greater sense of personal well-being, but less often recognized the examples of discrimination and structural barriers presented in the statistics.

In a follow-up experiment, the researchers examined the consequences of the common cultural representation of women's workplace departure as a choice. Specifically, they examined how exposure to a choice message influenced Americans' beliefs about equality and the existence of discrimination. First, undergraduate students were subtly exposed to one of two posters on a wall about women leaving the workforce: either a poster with a choice message ("Choosing to Leave: Women's Experiences Away from the Workforce") or one in a control condition that simply said "Women at Home: Experiences Away from the Workforce."

Then, the participants were asked to take a survey about social issues. The participants exposed to the first poster with the choice message more strongly endorsed the belief that opportunities are equal and that gender discrimination is nonexistent, versus the control group who more clearly recognized discrimination. Interestingly, those participants who considered themselves to be feminists were more likely than other participants to identify discrimination.

"This second experiment demonstrates that even subtle exposure to the choice framework promotes the belief that discrimination no longer exists," said Levine. "One single brief encounter – such as a message in a poster – influenced the ability to recognize discrimination. Regular exposure to such messages could intensify over time, creating a vicious cycle that keeps women from reaching the top of high-status fields."

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UMD Brain Cap Technology Turns Thought İnto Motion

"Brain cap" technology being developed at the University of Maryland allows users to turn their thoughts into motion. Associate Professor of Kinesiology José 'Pepe' L. Contreras-Vidal and his team have created a non-invasive, sensor-lined cap with neural interface software that soon could be used to control computers, robotic prosthetic limbs, motorized wheelchairs and even digital avatars. "We are on track to develop, test and make available to the public—within the next few years—a safe, reliable, noninvasive brain computer interface that can bring life-changing technology to millions of people whose ability to move has been diminished due to paralysis, stroke or other injury or illness," said Contreras-Vidal of the university's School of Public Health.

The potential and rapid progression of the UMD brain cap technology can be seen in a host of recent developments, including a just published study in the Journal of Neurophysiology, new grants from the National Science Foundation (NSF) and National Institutes of Health (NIH), and a growing list of partners that includes the University of Maryland School of Medicine, the Veterans Affairs Maryland Health Care System, the Johns Hopkins University Applied Physics Laboratory, Rice University and Walter Reed Army Medical Center's Integrated Department of Orthopaedics & Rehabilitation.

"We are doing something that few previously thought was possible," said Contreras-Vidal, who is also an affiliate professor in Maryland's Fischell Department of Bioengineering and the university's Neuroscience and Cognitive Science Program. "We use EEG [electroencephalography] to non-invasively read brain waves and translate them into movement commands for computers and other devices.

Peer Reviewed

Contreras-Vidal and his team have published three major papers on their technology over the past 18 months, the latest a just released study in the Journal of Neurophysiology in which they successfully used EEG brain signals to reconstruct the complex 3-D movements of the ankle, knee and hip joints during human treadmill walking. In two earlier studies they showed (1) similar results for 3-D hand movement and (2) that subjects wearing the brain cap could control a computer cursor with their thoughts.

Alessandro Presacco, a second-year doctoral student in Contreras-Vidal's Neural Engineering and Smart Prosthetics Lab, Contreras-Vidal and co-authors write that their Journal of Neurophysiology study indicated "that EEG signals can be used to study the cortical dynamics of walking and to develop brain-machine interfaces aimed at restoring human gait function."

There are other brain computer interface technologies under development, but Contreras-Vidal notes that these competing technologies are either very invasive, requiring electrodes to be implanted directly in the brain, or, if noninvasive, require much more training to use than does UMD's EEG-based, brain cap technology.

Partnering to Help Sufferers of Injury and Stroke

Contreras-Vidal and his team are collaborating on a rapidly growing cadre of projects with researchers at other institutions to develop thought-controlled robotic prosthetics that can assist victims of injury and stroke.

Their latest partnership is supported by a new $1.2 million NSF grant. Under this grant, Contreras-Vidal's Maryland team is embarking on a four-year project with researchers at Rice University, the University of Michigan and Drexel University to design a prosthetic arm that amputees can control directly with their brains, and which will allow users to feel what their robotic arm touches.

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Gene Gives Clues To Self-injurious Behavior İn Rare Disorder

In humans, inherited mutations in a gene called HPRT1 lead to very specific self-destructive behavior. Boys with Lesch-Nyhan disease experience uncontrollable urges to bite their fingers, slam their arms into doorways and otherwise harm themselves. Puzzlingly, mice with mutations in the same gene don't behave differently than normal mice. Researchers at Emory University School of Medicine have identified a gene related to HPRT1, present in humans but not in mice that helps explain this discrepancy.

The results were published this week by the journal PLoS One.

Mice missing HPRT1 and engineered with a copy of the related human gene, called PRTFDC1, are more aggressive and, under the influence of amphetamines, display repetitive behavior resembling nail biting.

"Other strains of mice don't do this, even under the influence of amphetamines," says first author Alaine Keebaugh, an Emory postdoctoral fellow. "It's not exactly the same as the finger-biting seen in Lesch-Nyhan patients, but they're close enough that we think it provides some insight into the biology. It suggests that PRTFDC1 could be a target for treating the disease."

Keebaugh began researching HPRT1 and PRTFDC1 while a graduate student in the laboratory of James Thomas, PhD, former assistant professor of human genetics at Emory University School of Medicine. The co-first author is Emory postdoctoral fellow Heather Mitchell.

HPRT1 was the first gene to be "knocked out" when scientists were first developing the technique in the 1980s, an accomplishment that earned Mario Capecchi and Oliver Smithies the Nobel Prize in Medicine.

"HPRT1 has a special place in the history of genetics because of this," Keebaugh says. "It also shows that knockout mice don't always exactly parallel human disease."

The HPRT1 gene is located on the X chromosome. Males are vulnerable to Lesch-Nyhan disease (and other X-linked disorders) because they have only one X chromosome. HPRT1 encodes an enzyme that recycles purines, which are building blocks of DNA.

The PRTFDC1 gene looks like HPRT1, and apparently comes from a duplication of an ancestor gene millions of years ago. All mammals Keebaugh examined except mice have working copies of PRTFDC1. It's not clear whether the protein encoded by PRTFDC1 also recycles purines, she says.

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Tight Trading and Lending Conditions Are Hindering Expansion İn The Construction İndustry

The UK Gross Domestic Product (GDP) has increased by only 0.2 per cent in the second quarter of 2011, following an increase of 0.5 per cent in the first quarter of 2011.

Construction output increased by 0.5 per cent in the second quarter, compared with a decrease of 3.4 per cent in the previous quarter. Government and other services showed zero growth, compared with a 1.1 per cent increase in the previous quarter.

Julia Evans, Chief Executive of NFB, said: “While any growth, however small, is to be welcomed at this time, it is still of concern to our members that tight trading and lending conditions have hindered expansion in the construction industry. Add to that the fact that public spending cuts are now biting, and lending has not appeared to have kept up with private sector demand, we are left with a significant gap in order books. It is not just about keeping turnovers ticking over – these companies need profits in order to survive.

We hope that the Government’s Construction Strategy will help to provide some glimmer of certainty in the form of longer term pipelines of work, in what is increasingly becoming a very worrying time for the industry. Particularly affected are the small and medium sized businesses which make up 90 per cent of the sector and contribute much to the economy. It is imperative therefore that public sector procurers do not lose sight of the ‘whole life’ value of projects in favour of ‘lowest cost’ in the drive for efficiency savings. That is a fallacy that could well have longer term impacts that could be damaging to the industry, as well as the economy.”

On a more encouraging note, looked at over the longer term, construction was one of the sectors that suffered the most in the recession and so has the most scope to grow in the recovery.

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Child-size Mannequin: Hands-on Training Spares Real Patients

Rice University bioengineering students have modified a child-size training mannequin to give medical students hands-on pediatric experience so that real patients can be spared further stress and pain. The students created Ped.IT, short for Pediatric Evaluation Device Intended for Training, as their senior design project at the request of doctors at Texas Children's Hospital (TCH) who have long recognized the need for students to get hands-on experience in pediatrics without having to subject young patients to additional probing and exams.

"I've been trying since 2003 to develop a mannequin, but I didn't have the bioengineering skills," said Amy Middleman, a pediatrician at TCH and associate professor at Baylor College of Medicine (BCM), which funded the project. "For a long time I've wanted to be able to teach medical students physical exam skills without having to use patients who are not feeling well and whose parents really aren't comfortable with medical students coming in to examine them."

Having tried and failed to work with medical device manufacturers, Middleman found her way to Rice's Oshman Engineering Design Kitchen (OEDK) and its director, Maria Oden, a professor in the practice of engineering education.

Oden pitched the idea to student teams at the start of the fall semester. The four students who stepped up -- Kshitij Manchanda, Zachary Henderson, Minsuk Kwak and Michelle Thorson -- succeeded in modifying a stock medical training mannequin to TCH's specs, with help from their Rice adviser, Renata Ramos, a lecturer in bioengineering.

Ped.IT (which students have dubbed the "MiddleMannequin" in honor of their mentor) began as a hard-shell mannequin donated by a manufacturer, Laerdal. The team replaced the neck and midriff areas of the plastic with simulated skin and added the simulated liver and spleen, that TCH requested. The students went beyond the call of duty by adding simulated lymph nodes, and they left room for more organs to be added by future OEDK teams.

"There are a lot of conditions our mentors at Texas Children's would like to see in a future version of the mannequin, including an enlarged thyroid and tonsils," Henderson said. "They would also like joints that could be popped out of place and put back in."

Computer-controlled actuators in the 4-foot-long mannequin allow medical students to change the organs from normal to enlarged states.

To create the effect, team members spent time at TCH feeling the livers and spleens of patients willing to help. Rice and Texas Children's are in close proximity in Houston's Texas Medical Center.

"We were completely confused about how a liver actually felt," Manchanda said. "Is it as hard as a rock? As soft as a pillow? I didn't know what the middle ground was. So when I felt them, I thought, 'Oh, this feels like Tempur-Pedic.' You could squeeze and it will come back to its shape."

Tempur-Pedic, best known as material for mattresses, was the right stuff for simulating organs. Another material, Dermasol, was used to simulate skin. "I feel like we've set a good groundwork for materials and the way to make a mannequin that is useful for the physical exam," Thorson said.

"We don't have anything like this in pediatrics," said Jennifer Arnold, medical director of the TCH Pediatric Simulation Center and a BCM assistant professor of pediatrics. "In fact, there's nothing quite like this in the adult world, either. I think there are huge possibilities for commercialization."

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