Steam energy from the sun: New spongelike structure converts solar energy into steam

A new material structure developed at MIT generates steam by soaking up the sun. The structure — a layer of graphite flakes and an underlying carbon foam — is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam. The brighter the light, the more steam is generated.The new material is able to convert 85 percent of incoming solar energy into steam — a significant improvement over recent approaches to solar-powered steam generation. What’s more, the setup loses very little heat in the process, and can produce steam at relatively low solar intensity. This would mean that, if scaled up, the setup would likely not require complex, costly systems to highly concentrate sunlight.Hadi Ghasemi, a postdoc in MIT’s Department of Mechanical Engineering, says the spongelike structure can be made from relatively inexpensive materials — a particular advantage for a variety of compact, steam-powered applications.”Steam is important for desalination, hygiene systems, and sterilization,” says Ghasemi, who led the development of the structure. “Especially in remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful.”Ghasemi and mechanical engineering department head Gang Chen, along with five others at MIT, report on the details of the new steam-generating structure in the journal Nature Communications.Cutting the optical concentrationToday, solar-powered steam generation involves vast fields of mirrors or lenses that concentrate incoming sunlight, heating large volumes of liquid to high enough temperatures to produce steam. However, these complex systems can experience significant heat loss, leading to inefficient steam generation.Recently, scientists have explored ways to improve the efficiency of solar-thermal harvesting by developing new solar receivers and by working with nanofluids. The latter approach involves mixing water with nanoparticles that heat up quickly when exposed to sunlight, vaporizing the surrounding water molecules as steam. But initiating this reaction requires very intense solar energy — about 1,000 times that of an average sunny day.By contrast, the MIT approach generates steam at a solar intensity about 10 times that of a sunny day — the lowest optical concentration reported thus far. …

Read more

Understanding eczema: How to avoid the itch

Learn more about Herbalife – Follow @Herbalife on Twitter- Like Herbalife on Facebook- What is Herbalife? More fitness advice – Watch ‘Fit Tips’ Videos on YouTube- Straightforward exercise advice- Get fit = be happy. Positivity advice Nutrition advice for you – Watch ‘Healthy Living’ on YouTube- Dieting advice you might like- Interesting weight loss articles Copyright © 2013 Herbalife International of America, Inc.

Read more

Solar-induced hybrid fuel cell produces electricity directly from biomass

Although low temperature fuel cells powered by methanol or hydrogen have been well studied, existing low temperature fuel cell technologies cannot directly use biomass as a fuel because of the lack of an effective catalyst system for polymeric materials.Now, researchers at the Georgia Institute of Technology have developed a new type of low-temperature fuel cell that directly converts biomass to electricity with assistance from a catalyst activated by solar or thermal energy. The hybrid fuel cell can use a wide variety of biomass sources, including starch, cellulose, lignin — and even switchgrass, powdered wood, algae and waste from poultry processing.The device could be used in small-scale units to provide electricity for developing nations, as well as for larger facilities to provide power where significant quantities of biomass are available.”We have developed a new method that can handle the biomass at room temperature, and the type of biomass that can be used is not restricted — the process can handle nearly any type of biomass,” said Yulin Deng, a professor in Georgia Tech’s School of Chemical and Biomolecular Engineering and the Institute of Paper Science and Technology (IPST). “This is a very generic approach to utilizing many kinds of biomass and organic waste to produce electrical power without the need for purification of the starting materials.”The new solar-induced direct biomass-to-electricity hybrid fuel cell was described February 7, 2014, in the journal Nature Communications.The challenge for biomass fuel cells is that the carbon-carbon bonds of the biomass — a natural polymer — cannot be easily broken down by conventional catalysts, including expensive precious metals, Deng noted. To overcome that challenge, scientists have developed microbial fuel cells in which microbes or enzymes break down the biomass. But that process has many drawbacks: power output from such cells is limited, microbes or enzymes can only selectively break down certain types of biomass, and the microbial system can be deactivated by many factors.Deng and his research team got around those challenges by altering the chemistry to allow an outside energy source to activate the fuel cell’s oxidation-reduction reaction.In the new system, the biomass is ground up and mixed with a polyoxometalate (POM) catalyst in solution and then exposed to light from the sun — or heat. A photochemical and thermochemical catalyst, POM functions as both an oxidation agent and a charge carrier. POM oxidizes the biomass under photo or thermal irradiation, and delivers the charges from the biomass to the fuel cell’s anode. The electrons are then transported to the cathode, where they are finally oxidized by oxygen through an external circuit to produce electricity.”If you mix the biomass and catalyst at room temperature, they will not react,” said Deng. “But when you expose them to light or heat, the reaction begins. The POM introduces an intermediate step because biomass cannot be directly accessed by oxygen.”The system provides major advantages, including combining the photochemical and solar-thermal biomass degradation in a single chemical process, leading to high solar conversion and effective biomass degradation. …

Read more

Love at the office? When relationships go from platonic to romantic

There are three key factors that contribute to how coworkers respond to a workplace romance including how they learn about the romance, their personal views of those participating in the romance and the company culture, suggests Sean Horan, assistant professor of relational communication in DePaul University’s College of Communication.Horan is coauthor of a new study, “Love at the Office? Understanding Workplace Romance Disclosures and Reactions from the Coworker Perspective,” which was published online Feb. 5 in the Western Journal of Communication and will be printed in the March issue. The research explores the effect of workplace romances on coworkers and whether responses are primarily influenced by how the relationship is disclosed to them.”I was interested in studying workplace romances because they are incredibly common yet, across social science, there is little research in the area,” said Horan.Horan, along with coauthor Renee Cowan, assistant professor at the University of Texas at San Antonio, discovered that if coworkers found out from the couple personally, there tended to be a more positive reaction than if they found out via office gossip or catching them “in the act.””Individuals had much different reactions based on how they learned of the romance,” explained Horan. “Being honest and upfront was better received than, let’s say, walking in on your coworkers kissing in the parking garage or hearing it via office gossip.”How people personally perceived individuals in the relationship also plays a key role in their reaction. The titles of those in the workplace romance also affected their reaction, Horan said.For example, in Horan’s previous research in this area, he found that when a coworker dates a superior, they are likely to be lied to more, trusted less and viewed as less credible. One participant in the current study noted, “I was just taken aback because I knew he was pretty high up with the company and she not so much.”Additionally, the study found that company culture contributes to how coworkers view workplace romances. The authors propose that, often, more relaxed office environments don’t have official policies on interoffice relationships, making them more acceptable, while more formal offices have strict policies in place, which distinguish them as inappropriate and unprofessional.”It (the organization environment) kind of seemed like a college so it didn’t seem too unprofessional,” said another participant.This is the fourth study in an ongoing series by Horan on workplace romance.”I’ve concluded a couple of my studies the same way by saying ‘date at your own risk,'” he said.”Employees need to be aware that their peers will communicate with them differently if they have a workplace romance. Importantly, such differences can influence productivity and performance,” Horan explained.”It’s always awkward seeing your ex. Now imagine having to see them all day, every day at work.”Story Source:The above story is based on materials provided by DePaul University. …

Read more

Unique new dataset CLIMBER: Climatic niche characteristics of the butterflies in Europe

Scientists from the Helmholtz Centre for Environmental Research — UFZ present CLIMBER: Climatic niche characteristics of the butterflies in Europe -a unique dataset on the climatic niche characteristics of 397 European butterflies representing impressive 91% of the European species. The information provided in this dataset is of great relevance for basic and applied ecology and provides a combination of high quality standards and open access, data ready to use for a broad range of applications. The data paper describing the characteristics of the compilation was published in the open access journal ZooKeys.Global change seriously threatens biodiversity at all organisational levels ranging from properties of single species, through communities and species assemblages to whole ecosystems including the provision of ecosystem services for human well-being. Detailed information on species’ ecological niche characteristics is indispensable for a better understanding of the relationship between the occurrence and performance of wild species and their environment and, moreover, for an improved assessment of the impacts of global change.Knowledge on species characteristics such as habitat requirements is already available in the ecological literature for butterflies, but information about their climatic requirements is still lacking. The new CLIMBER dataset attempts to fill this gap by providing unique information on the climatic niche characteristics of 397 European butterflies. These characteristics are obtained by combining detailed information on butterfly distributions in Europe, which also led to the ‘Distribution Atlas of European Butterflies’ (Kudrna 2002), the ‘Climatic Risk Atlas of European Butterflies (Settele et al. 2008) and the ‘Distribution Atlas of Butterflies in Europe’ (Kudrna et al. 2011).The application potential of this database ranges from theoretical aspects such as assessments of past niche evolution or analyses of trait interdependencies to the very applied aspects of measuring, monitoring and projecting historical, ongoing and potential future responses to climate change using butterflies as an indicator. Good knowledge of the ecological characteristics relevant for the reaction of species and communities to particular drivers of global change is needed, which can then be utilised as powerful indicators for conservation planning and action.”By combining a comprehensive database on the distribution of European butterflies with publicly available climatic data in combination with a constantly high level of quality control at crucial steps of the data generation, CLIMBER represents a unique and ready-to-use dataset for a broad variety of potential applications, “comments Dr. Oliver Schweiger, Helmholtz Centre for Environmental Research — UFZ.”By providing public access to this dataset, we hope to contribute to improvements of the scientific understanding of how climate change affects species and communities and to improve monitoring and conservation actions for climate change mitigation,” he adds on the choice of open access for the dataset.Story Source:The above story is based on materials provided by Pensoft Publishers. …

Read more

Babies know when you’re faking, psychology researchers show

Oct. 16, 2013 — If you’re happy and you know it, clap your hands! That’s easy enough for children to figure out because the emotion matches the movement. But when feelings and reactions don’t align, can kids tell there’s something wrong? New research from Concordia University demonstrates that they can — as early as 18 months.In a study recently published in Infancy: The Official Journal of the International Society on Infant Studies, psychology researchers Sabrina Chiarella and Diane Poulin-Dubois demonstrate that infants can detect whether a person’s emotions are justifiable given a particular context. They show that babies understand how the meaning of an experience is directly linked to the expressions that follow.The implications are significant, especially for caregivers. “Our research shows that babies cannot be fooled into believing something that causes pain results in pleasure. Adults often try to shield infants from distress by putting on a happy face following a negative experience. But babies know the truth: as early as 18 months, they can implicitly understand which emotions go with which events,” says psychology professor Poulin-Dubois.To perform the research, she and PhD candidate Sabrina Chiarella recruited 92 infants at the 15 and 18-month mark. In a lab setting, the babies watched as an actor went through several scenarios in which emotional reactions went with or against pantomimed experiences. …

Read more

Motorized microscopic matchsticks move in water with sense of direction

Sep. 10, 2013 — Chemists, physicists and computer scientists at the University of Warwick have come together to devise a new powerful and very versatile way of controlling the speed and direction of motion of microscopic structures in water using what they have dubbed chemically ‘motorised microscopic matchsticks’.Before now most research seeking to influence the direction of motion of microscopic components have had to use outside influences such as a magnetic field or the application of light. The University of Warwick team have now found a way to do it by simply adding a chemical in a specific spot and then watching the microscopic matchstick particles move towards it, a phenomenon known as chemotaxis.The research published in the journal Materials Horizons (RSC) in a paper entitled “Chemotaxis of catalytic silica-manganese oxide “matchstick” particles” found that by adding a small amount of a catalyst to the head of a set microscopic rods, they could then cause the rods to be propelled towards the location of an appropriate ‘chemical fuel’ that was then added to a mixture.For the purposes of this experiment the researchers placed silica-manganese oxide ‘heads’ on the matchstick material and introduced hydrogen peroxide as the chemical fuel in one particular place.They placed the ‘matchsticks’ in a mixture alongside ordinary polymer microspheres.When the hydrogen peroxide was added the microspheres continued to move in the direction of convection currents or under Brownian motion but the matchsticks were clearly rapidly propelled towards the chemical gradient where the hydrogen peroxide could be found.The reaction was so strong that more than half of the matchstick particles did not reverse their orientation once over their 90 seconds of travel towards the hydrogen peroxide — even though they were contending with significant convection and Brownian rotation.University of Warwick research chemical engineer Dr Stefan Bon who led the research said:”We choose high aspect ratio rod-like particles as they are a favourable geometry for chemotactic swimmers, as seen for example in nature in the shapes of certain motile organisms””We placed the ‘engine’ that drives the self-propulsion as a matchstick head on the rods because having the engine in the ‘head’ of the rod helps us align the rod along the direction of travel, would also show the asymmetry perpendicular to the direction of self-propulsion, and at the same time it maintains rotational symmetry parallel to the plane of motion.”Our approach is very versatile and should allow for future fabrication of micro-components of added complexity.”The ability to direct motion of these colloidal structures can form a platform for advances in supracolloidal science, the self-assembly of small objects.”It may even provide some insight into how rod shapes were selected for self-propelled microscopic shapes in the natural world.”

Read more

How do consumers compare prices? It depends on how powerful they feel

Sep. 10, 2013 — Your reaction to the price on a bottle of wine or another product is partly a response to how powerful you feel, according to a new study in the Journal of Consumer Research.”The degree to which one feels powerful influences which type of price comparison threatens their sense of self-importance and, in turn, affects the perception of price unfairness,” write authors Liyin Jin, Yanqun He (both Fudan University), and Ying Zhang (University of Texas, Austin).Variations in price are common in today’s market, the authors explain, but companies risk consumers’ wrath when those customers perceive unfairness. According to the authors, consumers have two main ways of evaluating the fairness of a price: they compare with what they’ve paid for the same item in the past (self-comparison) or they ask how the price compares with what other customers are paying (other-comparison). The authors looked at the ways consumers’ self-perceptions affected their reactions to the two kinds of comparisons.In one study, the authors found that participants who felt powerful experienced more unfairness when it appeared that they were paying more than others. But people who did not feel powerful experienced more unfairness when they used self-comparisons. The study also revealed that “high-power” participants were more likely to get angry about unfairness and indicated they were more likely to complain about the perceived unfairness. Meanwhile the “low-power” individuals were more likely to feel sad and to use tactics to avoid thinking about the unfair price.”Our findings suggest important ways that marketing professionals can engage customers of different power statuses,” the authors write. “For example, when marketing to high-power customers, one can better elicit preference by highlighting the special treatment that they are receiving in relation to other customers. Conversely, when the target customers are relatively low in power, loyalty may be better cultivated by highlighting the consistency in service or the level of commitment to these customers.”

Read more

Tattoos reduce chances of getting a job

Sep. 4, 2013 — Having a tattoo can reduce your chance of getting a job, but it depends on where the tattoo is, what it depicts and if the job involves dealing with customers, new research says.Dr Andrew R. Timming told the British Sociological Association conference on work, employment and society in Warwick today that employers were prone to view tattoos negatively. Dr Timming, of the School of Management at the University of St Andrews, said he had spoken to 15 managers involved in hiring staff about their reaction to interview candidates with visible tattoos. The managers worked for organisations including a hotel, bank, city council, prison, university and bookseller.”Most respondents agreed that visible tattoos are a stigma,” Dr Timming told the conference. One woman manager told him that “they make a person look dirty.” Another male manager told him “subconsciously that would stop me from employing them.” Another male manager said “tattoos are the first thing they [fellow recruiters] talk about when the person has gone out of the door.”The managers were concerned about what their organisations’ customers might think, said Dr Timming. “Hiring managers realise that, ultimately, it does not matter what they think of tattoos — what really matters, instead, is how customers might perceive employees with visible tattoos.”Respondents expressed concern that visibly tattooed workers may be perceived by customers to be ‘abhorrent’, ‘repugnant’, ‘unsavoury’ and ‘untidy’. It was surmised that customers might project a negative service experience based on stereotypes that tattooed people are thugs and druggies.”One woman manager told him: “We all judge people on first impressions and what we sum up is quite quick. When they [customers] walk in the door and see that there’s a receptionist with guns or knives tattooed, or ‘hate’ tattooed, I think that is something that would be uncomfortable.”Dr Timming said: “The one qualification to this argument is there are certain industries in which tattoos may be a desirable characteristic in a job interview. For example, an HR manager at a prison noted that tattoos on guards can be ‘something to talk about’ and ‘an in’ that you need to make a connection with the prisoners.”The negative attitude to tattoos did not extend to ones that could be easily concealed by clothing. …

Read more

Unexpected use of former cancer drug

Aug. 29, 2013 — Researchers at Lund University have unexpectedly discovered that an old cancer drug can be used to prevent rejection of transplanted tissue. The researchers now have high hopes that their discovery could lead to new treatments for both transplant patients and patients with autoimmune diseases.The researchers behind the study, which has been published in the scientific journal PLOS ONE, work at the Rausing Laboratory, Lund University, where they have conducted research on brain tumours over many years.”Our group were studying the effects of the old tumour drug Zebularine, developed in the USA in the 1960s, and by chance we discovered that it had completely unexpected effects on the immune system,” says Leif Salford, Senior Professor of Neurosurgery.”It turned out that Zebularine has the ability to subdue the reaction of the body’s immune system. This could be important in situations where tissue or organs are transplanted. We also think it could be used to curb the body’s attacks on its own tissue in autoimmune diseases, for instance type 1 diabetes or rheumatoid arthritis,” says Dr Nittby.In studies on animals, the researchers used rats that were made diabetic. The researchers transplanted the islets of Langerhans — cell groups in the pancreas producing insulin — from healthy rats from another kind of rat into those with diabetes. The diabetic rats were divided into two groups; one group were treated with Zebularine and the other, the control group, did not receive any treatment. The diabetic rats that were treated with Zebularine survived for a significantly longer period than the untreated rats.”It is very interesting that we only treated them with Zebularine for two weeks, but the effects of the treatment could be observed throughout the 90-day follow-up period.”The findings are very exciting and are a sign that the immune system was not just generally suppressed, but that the treatment was more targeted. Neither did we see any signs of side-effects,” said Dr Nittby.The researchers are now working intensively to further refine the treatment. The next step is to teach certain cells in the immune system — the dendritic cells — to accept certain specific proteins using the Zebularine treatment. …

Read more

Scientists analyze the effects of ocean acidification on marine species

Aug. 25, 2013 — Ocean acidification could change the ecosystems of our seas even by the end of this century. Biologists at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have therefore assessed the extent of this ominous change for the first time. In a new study they compiled and analysed all available data on the reaction of marine animals to ocean acidification. The scientists found that whilst the majority of animal species investigated are affected by ocean acidification, the respective impacts are very specific.The AWI-researchers present their results as an Advance Online Publication on Sunday 25 August 2013 in Nature Climate Change.The oceans absorb more than a quarter of anthropogenic carbon dioxide emitted to the atmosphere. They form a natural store without which Earth would now be a good deal warmer. But their storage capacities are limited and the absorption of carbon dioxide is not without consequence. Carbon dioxide dissolves in water, forms carbonic acid and causes the pH value of the oceans to drop — which affects many sea dwellers. In recent years much research has therefore been conducted on how individual species react to the carbon dioxide enrichment and the acidifying water. So far the overall extent of these changes on marine animals has been largely unknown.In order to gain an initial overview, Dr. …

Read more

Pass the salt: Common condiment could enable new high-tech industry — silicon nanostructures

Aug. 8, 2013 — Chemists at Oregon State University have identified a compound that could significantly reduce the cost and potentially enable the mass commercial production of silicon nanostructures — materials that have huge potential in everything from electronics to biomedicine and energy storage.This extraordinary compound is called table salt.Simple sodium chloride, most frequently found in a salt shaker, has the ability to solve a key problem in the production of silicon nanostructures, researchers just announced in Scientific Reports, a professional journal.By melting and absorbing heat at a critical moment during a “magnesiothermic reaction,” the salt prevents the collapse of the valuable nanostructures that researchers are trying to create. The molten salt can then be washed away by dissolving it in water, and it can be recycled and used again.The concept, surprising in its simplicity, should open the door to wider use of these remarkable materials that have stimulated scientific research all over the world.”This could be what it takes to open up an important new industry,” said David Xiulei Ji, an assistant professor of chemistry in the OSU College of Science. “There are methods now to create silicon nanostructures, but they are very costly and can only produce tiny amounts.”The use of salt as a heat scavenger in this process should allow the production of high-quality silicon nanostructures in large quantities at low cost,” he said. “If we can get the cost low enough many new applications may emerge.”Silicon, the second most abundant element in Earth’s crust, has already created a revolution in electronics. But silicon nanostructures, which are complex structures much smaller than a speck of dust, have potential that goes far beyond the element itself.Uses are envisioned in photonics, biological imaging, sensors, drug delivery, thermoelectric materials that can convert heat into electricity, and energy storage.Batteries are one of the most obvious and possibly first applications that may emerge from this field, Ji said. It should be possible with silicon nanostructures to create batteries — for anything from a cell phone to an electric car — that last nearly twice as long before they need recharging.Existing technologies to make silicon nanostructures are costly, and simpler technologies in the past would not work because they required such high temperatures. Ji developed a methodology that mixed sodium chloride and magnesium with diatomaceous earth, a cheap and abundant form of silicon.When the temperature reached 801 degrees centigrade, the salt melted and absorbed heat in the process. This basic chemical concept — a solid melting into a liquid absorbs heat — kept the nanostructure from collapsing.The sodium chloride did not contaminate or otherwise affect the reaction, researchers said. Scaling reactions such as this up to larger commercial levels should be feasible, they said.The study also created, for the first time with this process, nanoporous composite materials of silicon and germanium. …

Read more

New target identified for food allergy therapy

Aug. 1, 2013 — Researchers at National Jewish Health have identified an enzyme that is essential to the allergic reaction to peanuts. Blocking the enzyme’s activity in sensitized mice prevented diarrhea and inflammation, and reduced levels of several proteins associated with allergies. The findings, published online in the Journal of Allergy and Clinical Immunology, identify the enzyme, known as Cyp11a1, as a potential target for treatment of increasingly common and potentially deadly food allergy.”Right now, we have no therapy for food allergy other than to avoid the allergenic food,” said senior author, Erwin Gelfand, MD, chair of Pediatrics at National Jewish Health. “In Cyp11a1, we have found an essential enzyme and signaling pathway in the intestinal allergic reaction, which are potential targets for intervention.”Food allergy has become more common in recent decades, now affecting about 8 percent of the American population. Among children, peanuts are the most common food allergy and can provoke severe, even life threatening, allergic reactions. Antihistamines and epinephrine are used in response to allergic reactions, but there is no approved therapy for the prevention of allergic reactions to food.Cyp11a1 promotes the first and rate-limiting step in the production of corticosteroids. These steroids have long been used to treat allergic diseases because they inhibit inflammation associated with the allergic reaction. Evidence in recent years, however, has indicated that corticosteroids may also activate immune cells associated with allergic reactions.The researchers sensitized mice to peanuts so that they became allergic to the legume. When subsequently fed peanut protein, the mice experienced diarrhea and inflammation in the small intestine. …

Read more

Robots strike fear in the hearts of fish: Anxious zebrafish help researchers understand how alcohol affects fear

July 31, 2013 — The latest in a series of experiments testing the ability of robots to influence live animals shows that bio-inspired robots can not only elicit fear in zebrafish, but that this reaction can be modulated by alcohol. These findings may pave the way for new methodologies for understanding anxiety and other emotions, as well as substances that alter them.Maurizio Porfiri, associate professor of mechanical and aerospace engineering at the Polytechnic Institute of New York University (NYU-Poly) and Simone Macrì, a collaborator at the Istituto Superiore di Sanità in Rome, Italy, published their findings in PLOS ONE, an international, peer-reviewed, open-access, online publication.This latest study expands Porfiri and Macrì’s efforts to determine how bio-inspired robots can be employed as reliable stimuli to elicit reactions from live zebrafish. Previous studies have established that zebrafish show a strong affinity for robotic members designed to swim and appear as one of their own and that this preference can be abolished by exposing the fish to ethanol.Porfiri and Macri, along with students Valentina Cianca and Tiziana Bartolini, hypothesized that robots could be used to induce fear as well as affinity and designed a robot mimicking the morphology and locomotion pattern of the Indian leaf fish, a natural predator of the zebrafish. In the lab, they simulated a harmless predatory scenario, placing the zebrafish and the robotic Indian leaf fish in separate compartments of a three-section tank. The other compartment was left empty. The control group uniformly avoided the robotic predator, showing a preference for the empty section.To determine whether alcohol would affect fear responses, the researchers exposed separate groups of fish to different doses of ethanol in water. Ethanol has been shown to influence anxiety-related responses in humans, rodents and some species of fish. The zebrafish exposed to the highest concentrations of ethanol showed remarkable changes in behavior, failing to avoid the predatory robot. Acute administration of ethanol causes no harm and has no lasting effect on zebrafish.”These results are further evidence that robots may represent an exciting new approach in evaluating and understanding emotional responses and behavior,” said Porfiri. “Robots are ideal replacements as independent variables in tests involving social stimuli — they are fully controllable, stimuli can be reproduced precisely each time, and robots can never be influenced by the behavior of the test subjects.”To validate their findings and ensure that the zebrafish behavior being modulated was, in fact, a fear-based response, Porfiri and his collaborators conducted two traditional anxiety tests and evaluated whether the results obtained therein were sensitive to ethanol administration.They placed test subjects in a two-chamber tank with one well-lit side and one darkened side, to establish which conditions were preferable. …

Read more

Chemical reaction could streamline manufacture of pharmaceuticals and other compounds

July 22, 2013 — Researchers at The University of Texas at Austin have discovered a new chemical reaction that has the potential to lower the cost and streamline the manufacture of compounds ranging from agricultural chemicals to pharmaceutical drugs.The reaction resolves a long-standing challenge in organic chemistry in creating phenolic compounds from aromatic hydrocarbons quickly and cheaply.Phenolic compounds, or phenols, are broadly used as disinfectants, fungicides and drugs to treat many ailments such as Parkinson’s disease. Creating a phenol seems deceptively simple. All it requires is replacing a hydrogen molecule on an aromatic hydrocarbon with an oxygen molecule.”This is a chemical transformation that is underdeveloped and at the same time pivotal in the production of many chemicals important to life as we know it,” said Dionicio Siegel, an assistant professor of chemistry in the College of Natural Sciences at The University of Texas at Austin.The secret that Siegel and his colleagues discovered is a substance called phthaloyl peroxide. This chemical was studied in the late 1950s and early 1960s, but it has been largely ignored during the intervening years.The scientists were conducting basic studies on phthaloyl peroxide, building on previous research, and decided to use it to tackle the age-old problem of transforming aromatic hydrocarbons into phenols.The advantage to using phthaloyl peroxide is that the reaction does not require the use of acids or catalysts to work, and it can add oxygen to a wide variety of starting materials.”There are no special conditions,” said Siegel. “You just combine the reagents, mix them and go. It’s very simple and straight forward.”The paper describing this discovery was published last week in Nature.The new process can be applied to other problems in organic chemistry. One particular area of interest is creating metabolites to drugs. Metabolites are the products left after the body finishes breaking down, or metabolizing, a substance. When testing drugs, scientists need to take into account not just how the drug itself reacts in the body, but also how the metabolites react.”We’ve had a long-standing interest in accessing metabolites of drugs or compounds that are used in biological systems,” said Siegel. “Just as it’s important that the drug doesn’t have deleterious side effects, it’s equally important that the metabolite doesn’t have an effect. …

Read more

‘Impossible’ material made with record-breaking surface area and water adsorption abilities

July 17, 2013 — A novel material with world record-breaking surface area and water adsorption abilities has been synthesized by researchers from Uppsala University, Sweden.The results are published today in PLOS ONE.The magnesium carbonate material that has been given the name Upsalite is foreseen to reduce the amount of energy needed to control environmental moisture in the electronics and drug formulation industry as well as in hockey rinks and ware houses. It can also be used for collection of toxic waste, chemicals or oil spill and in drug delivery systems, for odor control and sanitation after fire.”In contrast to what has been claimed for more than 100 years in the scientific literature, we have found that amorphous magnesium carbonate can be made in a very simple, low-temperature process,” says Johan Goméz de la Torre, researcher at the Nanotechnology and Functional Materials Division.While ordered forms of magnesium carbonate, both with and without water in the structure, are abundant in nature, water-free disordered forms have been proven extremely difficult to make. In 1908, German researchers claimed that the material could indeed not be made in the same way as other disordered carbonates, by bubbling CO2 through an alcoholic suspension. Subsequent studies in 1926 and 1961 came to the same conclusion.”A Thursday afternoon in 2011, we slightly changed the synthesis parameters of the earlier employed unsuccessful attempts, and by mistake left the material in the reaction chamber over the weekend. Back at work on Monday morning we discovered that a rigid gel had formed and after drying this gel we started to get excited,” says Johan Goméz de la Torre.A year of detailed materials analysis and fine tuning of the experiment followed. One of the researchers got to take advantage of his Russian skill since some of the chemistry details necessary for understanding the reaction mechanism was only available in an old Russian PhD thesis.”After having gone through a number of state of the art materials characterization techniques it became clear that we had indeed synthesized the material that previously had been claimed impossible to make,” says Maria Strømme, professor of nanotechnology and head of the nanotechnology and functional materials division.The most striking discovery was, however, not that they had produced a new material but it was instead the striking properties they found that this novel material possessed. It turned out that Upsalite had the highest surface area measured for an alkali earth metal carbonate; 800 square meters per gram.”This places the new material in the exclusive class of porous, high surface area materials including mesoporous silica, zeolites, metal organic frameworks, and carbon nanotubes,” says Strømme.In addition we found that the material was filled with empty pores all having a diameter smaller than 10 nano meters. This pore structure gives the material a totally unique way of interacting with the environment leading to a number of properties important for application of the material. Upsalite is for example found to absorb more water at low relative humidities than the best materials presently available; the hydroscopic zeolites, a property that can be regenerated with less energy consumption than is used in similar processes today.”This, together with other unique properties of the discovered impossible material is expected to pave the way for new sustainable products in a number of industrial applications,” says Maria Strømme.The discovery will be commercialized though the University spin-out company Disruptive Materials (www.Disruptivematerials.com) that has been formed by the researchers together with the holding company of Uppsala University

Read more

Brain sets prices with emotional value

July 3, 2013 — You might be falling in love with that new car, but you probably wouldn’t pay as much for it if you could resist the feeling. Researchers at Duke University who study how the brain values things — a field called neuroeconomics — have found that your feelings about something and the value you put on it are calculated similarly in a specific area of the brain.The region is small area right between the eyes at the front of the brain. It’s called the ventromedial prefrontal cortex, or vmPFC for short. Scott Huettel, director of Duke’s Center for Interdisciplinary Decision Science, said scientists studying emotion and neuroeconomics had independently singled out this area of the brain in their research but neither group recognized that the other’s research was focused on it too.Now, after a series of experiments in which subjects were asked to modify how they felt about something either positively or negatively, the Duke group is arguing that emotional and economic calculations are more closely related than brain scientists had realized. The study appears July 3 in the Journal of Neuroscience.Earlier research by other groups had shown the vmPFC participates in calculating the value of rewards and that it is engaged by positive stimuli that aren’t really rewards, like a happy memory or a picture of a happy face. A separate line of studies had shown that this brain region also set values on little things like snacks.The vmPFC handles value tradeoffs such as ‘is that product worth parting with my hard-earned money?’ “This says that your emotions would enter into that tradeoff,” Huettel said.”The neuroscience fits with your intuitive understanding,” said Amy Winecoff, a graduate student in psychology and neuroscience who led the research. “Emotions appear to be relying on the same value system.”In the Duke study, experimental subjects were first trained to do “reappraisal,” in which they could change their emotional response to a situation. “In reappraisal you reassess the meaning of an emotional stimulus, rather than trying to avoid the emotional stimulus or suppress your reaction to it,” Winecoff said.While the subjects’ brains were being scanned using functional MRI, they were shown images of evocative scenes and faces. After each image the subjects were told to either let their feelings flow or to practice reappraisal to change their thoughts. Then they were asked to rate how positive or negative they felt.In the case of “an unregulated positive affect” — letting the good feelings flow — the vmPFC was shown to be working harder, which the researchers say could be used to predict how much value a person is putting on something. …

Read more

A 20-minute bout of yoga stimulates brain function immediately after

June 5, 2013 — Researchers report that a single, 20-minute session of Hatha yoga significantly improved participants’ speed and accuracy on tests of working memory and inhibitory control, two measures of brain function associated with the ability to maintain focus and take in, retain and use new information. Participants performed significantly better immediately after the yoga practice than after moderate to vigorous aerobic exercise for the same amount of time.The 30 study subjects were young, female, undergraduate students. The new findings appear in the Journal of Physical Activity and Health.”Yoga is an ancient Indian science and way of life that includes not only physical movements and postures but also regulated breathing and meditation,” said Neha Gothe, who led the study while a graduate student at the University of Illinois at Urbana-Champaign. Gothe now is a professor of kinesiology, health and sport studies at Wayne State University in Detroit. “The practice involves an active attentional or mindfulness component but its potential benefits have not been thoroughly explored.””Yoga is becoming an increasingly popular form of exercise in the U.S. and it is imperative to systematically examine its health benefits, especially the mental health benefits that this unique mind-body form of activity may offer,” said Illinois kinesiology and community health professor Edward McAuley, who directs the Exercise Psychology Laboratory where the study was conducted.The yoga intervention involved a 20-minute progression of seated, standing and supine yoga postures that included isometric contraction and relaxation of different muscle groups and regulated breathing. The session concluded with a meditative posture and deep breathing.Participants also completed an aerobic exercise session where they walked or jogged on a treadmill for 20 minutes. Each subject worked out at a suitable speed and incline of the treadmill, with the goal of maintaining 60 to 70 percent of her maximum heart rate throughout the exercise session.”This range was chosen to replicate previous findings that have shown improved cognitive performance in response to this intensity,” the researchers reported.Gothe and her colleagues were surprised to see that participants showed more improvement in their reaction times and accuracy on cognitive tasks after yoga practice than after the aerobic exercise session, which showed no significant improvements on the working memory and inhibitory control scores.”It appears that following yoga practice, the participants were better able to focus their mental resources, process information quickly, more accurately and also learn, hold and update pieces of information more effectively than after performing an aerobic exercise bout,” Gothe said. “The breathing and meditative exercises aim at calming the mind and body and keeping distracting thoughts away while you focus on your body, posture or breath. Maybe these processes translate beyond yoga practice when you try to perform mental tasks or day-to-day activities.”Many factors could explain the results, Gothe said. …

Read more

Water-rock reaction may provide enough hydrogen ‘food’ to sustain life in ocean’s crust or on Mars

May 30, 2013 — A chemical reaction between iron-containing minerals and water may produce enough hydrogen “food” to sustain microbial communities living in pores and cracks within the enormous volume of rock below the ocean floor and parts of the continents, according to a new study led by the University of Colorado Boulder.

The findings, published in the journal Nature Geoscience, also hint at the possibility that hydrogen-dependent life could have existed where iron-rich igneous rocks on Mars were once in contact with water.

Scientists have thoroughly investigated how rock-water reactions can produce hydrogen in places where the temperatures are far too hot for living things to survive, such as in the rocks that underlie hydrothermal vent systems on the floor of the Atlantic Ocean. The hydrogen gases produced in those rocks do eventually feed microbial life, but the communities are located only in small, cooler oases where the vent fluids mix with seawater.

The new study, led by CU-Boulder Research Associate Lisa Mayhew, set out to investigate whether hydrogen-producing reactions also could take place in the much more abundant rocks that are infiltrated with water at temperatures cool enough for life to survive.

“Water-rock reactions that produce hydrogen gas are thought to have been one of the earliest sources of energy for life on Earth,” said Mayhew, who worked on the study as a doctoral student in CU-Boulder Associate Professor Alexis Templeton’s lab in the Department of Geological Sciences.

“However, we know very little about the possibility that hydrogen will be produced from these reactions when the temperatures are low enough that life can survive. If these reactions could make enough hydrogen at these low temperatures, then microorganisms might be able to live in the rocks where this reaction occurs, which could potentially be a huge subsurface microbial habitat for hydrogen-utilizing life.”

When igneous rocks, which form when magma slowly cools deep within Earth, are infiltrated by ocean water, some of the minerals release unstable atoms of iron into the water. At high temperatures — warmer than 392 degrees Fahrenheit (200 degrees Celsius) — scientists know that the unstable atoms, known as reduced iron, can rapidly split water molecules and produce hydrogen gas, as well as new minerals containing iron in the more stable, oxidized form.

Mayhew and her co-authors, including Templeton, submerged rocks in water in the absence of oxygen to determine if a similar reaction would take place at much lower temperatures, between 122 and 212 degrees Fahrenheit (50 to 100 degrees Celsius). The researchers found that the rocks did create hydrogen — potentially enough hydrogen to support life.

To understand in more detail the chemical reactions that produced the hydrogen in the lab experiments, the researchers used “synchrotron radiation” — which is created by electrons orbiting in a humanmade storage ring — to determine the type and location of iron in the rocks on a microscale.

The researchers expected to find that the reduced iron in minerals like olivine had converted to the more stable oxidized state, just as occurs at higher temperatures. But when they conducted their analyses at the Stanford Synchrotron Radiation Lightsource at Stanford University, they were surprised to find newly formed oxidized iron on “spinel” minerals found in the rocks. Spinels are minerals with a cubic structure that are highly conductive.

Finding oxidized iron on the spinels led the team to hypothesize that, at low temperatures, the conductive spinels were helping facilitate the exchange of electrons between reduced iron and water, a process that is necessary for the iron to split the water molecules and create the hydrogen gas.

“After observing the formation of oxidized iron on spinels, we realized there was a strong correlation between the amount of hydrogen produced and the volume percent of spinel phases in the reaction materials,” Mayhew said. “Generally, the more spinels, the more hydrogen.”

Not only is there a potentially large volume of rock on Earth that may undergo these low temperature reactions, but the same types of rocks also are prevalent on Mars, Mayhew said. Minerals that form as a result of the water-rock reactions on Earth have been detected on Mars as well, which means that the process described in the new study may have implications for potential Martian microbial habitats.

Mayhew and Templeton are already building on this study with their co-authors, including Thomas McCollom at CU-Boulder’s Laboratory for Atmospheric and Space Physics, to see if the hydrogen-producing reactions can actually sustain microbes in the lab.

This study was funded by the David and Lucille Packard Foundation and with a U.S. Department of Energy Early Career grant to Templeton.

Read more

Utilizzando il sito, accetti l'utilizzo dei cookie da parte nostra. maggiori informazioni

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close