Thursday, August 5, 2010


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We know 'icy' Neptune is partially comprised of water molecules but until now we have had little means to test how water behaves in the extreme conditions that Neptune presents.

This is about to change as an international group of physicists draw up plans to use the new Facility for Antiprotons and Ion Research (FAIR) in Germany, which will be ready in 2015, to expose water molecules to heavy ion beams and thereby generate the same level of pressure on the water molecules that they experience within the very inhospitable core of Neptune.

The new plans being published in New Journal of Physics (co-owned by the Institute of Physics and German Physical Society) Thursday 22 July, explain how using high energy uranium beams in the future German facility is going to enable researchers to create conditions that push water molecules into a 'superionic' state and thereby observe water in conditions never before replicated.

The predicted 'superionic' state is an exotic hybrid phase of water composed of an oxygen lattice and a hydrogen liquid which under ambient conditions form stable H2O molecules in an ice lattice or in a liquid.

A total of 15 European, Russian and Chinese researchers from GSI Helmholzzentrun für Schwerionenforschung, Universität Rostock, Universidad de Castilla-La Mancha, Universite Paris-Sud, the Russian Academy of Sciences, and the Chinese Academy of Science explain how the use of the new heavy ion beams can simulate pressures up to several million times greater than anything on the surface of the Earth.

The researchers suggest that research into this 'superionic' state could be of paramount importance for the understanding of the magnetic field of Neptune and Uranus, which are very different from that of the Earth's.

The researchers cite the past decade's progress in the technology of strongly bunched, well focused, high quality intense heavy ion beams as the enabling force for this experiment - such beams will be made available when construction of FAIR is complete.

The heavy ion beams, which will be generated by the new particle accelerator at FAIR, will have advantages over other methods of exposing particles to high pressure, such as high explosives, gas guns, lasers, or pulsed power, because they will be able to apply a more uniform and more targeted pressure on the water molecules.

The researchers write, "The FAIR accelerator facilities will provide very powerful high quality heavy ion beams with unprecedented intensities. Extensive theoretical work on beam matter heating over the past decade has shown that the ion beams that will be generated at FAIR will be a very unique and very efficient tool to study High Energy Density Particles in those regions of the parameter space that are not so easy to access with the traditional method."

Institute of Physics


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A new study in the Journal of Consumer Research unlocks the key to making the price of a product seem less expensive to consumers.

Consumers tend to perceive products as more expensive when they are grouped with expensive item—and less expensive when grouped with inexpensive ones, according to authors Marcus Cunha, Jr. and Jeffrey D. Shulman (both University of Washington, Seattle). But the researchers found that marketers can help consumers form more accurate perceptions of prices by helping them create a "discriminating" mindset.

"In three experiments, we examine how perceptions of a price depend on other prices in the set and on whether consumers want to discriminate items or make a general inference about the prices in a product category," the authors write.

Advertisements or displays that elicit a "generalization mindset" can lead consumers to perceive a product price to be closely related to other products in the vicinity. "The opposite price perceptions will occur if a marketer's action encourages consumers to think about the uniqueness of a product in the set," the authors explain. In this case, when the consumer is being discriminating, a given price will be perceived as less expensive if it is viewed in the presence of other high-priced projects and more expensive when viewed in the context of less-expensive products.

As an example, the authors propose a strategy for an in-store display for a new MP3 player that emphasizes how the player is different from its competitors. "Our research shows that this puts consumers in a discrimination mindset," the authors explain. "As a consequence, when examining prices, consumers will focus on the relative differences of the prices leading to a lower-price perception for this MP3 player when it is in a set with more expensive players but to a higher-price perception when it is in a set with less-expensive players.

Marketers should note the way these situational factors affect consumers' judgments, the authors conclude.

University of Chicago


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A new form of paper with the built-in ability to fight disease-causing bacteria could have applications that range from anti-bacterial bandages to food packaging that keeps food fresher longer to shoes that ward off foot odor. A report about the new material, which consists of the thinnest possible sheets of carbon, appears in ACS Nano, a monthly journal.

Chunhai Fan, Qing Huang, and colleagues explained that scientists in the United Kingdom first discovered the material, known as graphene, in 2004. Since then, the race has been on to find commercial and industrial uses for graphene. Scientists have tried to use graphene in solar cells, computer chips, and sensors. Fan and Huang decided to see how graphene affects living cells.

So they made sheets of paper from graphene oxide, and then tried to grow bacteria and human cells on top. Bacteria were unable to grow on the paper, and it had little adverse effect on human cells. "Given the superior antibacterial effect of graphene oxide and the fact that it can be mass-produced and easily processed to make freestanding and flexible paper with low-cost, we expect this new carbon nanomaterial may find important environmental and clinical applications," the reports states.

(Photo: ACS Nano)

American Chemical Society


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Segmentation, the repetition of identical anatomical units, seems to be the secret behind the diversity and longevity of the largest and most common animal groups on Earth. Researchers from CNRS and Université Paris Diderot have shown that this characteristic was inherited from a common segmented ancestor thought to have lived 600 million years ago and whose presence “changed the face of the world”. This discovery is published in Science on 16 July 2010.

What do centipedes, earthworms and humans have in common? They all feature the repetition of anatomically identical units along the axis running from the front to the rear of their bodies. This characteristic, which researchers call segmentation, is shared by three large groups of animals. It may not be obvious at first glance though, as the repeated segments can be hidden by a shell or be partially fused. The segments are nevertheless present, laid out along the bilateral axis in the trunk, abdomen or thorax.

The first of these animal groups is the arthropods, which include centipedes but also insects, spiders, scorpions and crustaceans, representing by far the largest group of animals on the planet. With the highest number of species and individuals, it makes up nearly 40% of animal biomass. Apart from centipedes, whose segmentation is impossible to miss, arthropods also include grasshoppers, crickets and shrimps. Vertebrates, another highly diverse group, come next. They comprise most familiar animals, including humans, and they represent an evolutionary success. In this group, segmentation is found in the vertebrae of the backbone and, at a finer anatomical scale, in the muscles and nerves that spread from the spinal cord. The final group is the annelid worms, whose body is almost entirely formed of identical segments, such as sea and earthworms. They are also very numerous in terms of species, though much less conspicuous.

These three groups are not closely related to one another. So, where does their segmentation come from? Is it possible that they all inherited this feature from a very distant common ancestor that lived 600 million years ago, before the Cambrian explosion, which produced most of the large animal groups that exist today? Or has segmentation occurred several times during the history of evolution? This is the question addressed by the researchers of CNRS and Université Paris Diderot at the Institut Jacques Monod, because segments seem to offer a significant advantage to the groups that have them, in terms of diversity, longevity and overall evolutionary success.

The researchers found that the genes controlling segment formation during embryo development are almost the same in drosophila (an arthropod) and in annelid marine worms, on which they concentrated their studies. These similarities led them to conclude that the genes had been inherited from a common ancestor, which was itself segmented. It also appears that vertebrates inherited this characteristic from an ancestor they share with the arthopods and the annelids. This is what the researchers are now seeking to confirm.

This work supports the idea that segmentation only appeared once in the history of evolution and that it led to the broad diversity of animal groups possessing it. This old and controversial idea among zoologists, had never been proved until now. But why should segmentation be so advantageous? Over millions of years, and exposure to changing environmental constraints, it is easier for an animal to specialize a segment into a specific tool in response to a need, than to create a whole new organ from scratch. By chance, evolution may have played a winning card with segmentation, which profoundly marked the history of life on Earth. If one day we could play God and create artificial animals or even biomimetic robots, perhaps we too should think about it. But this is still within the realm of science fiction.

(Photo: © CNRS Photothèque / DEHARVENG Louis)



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A delicate wine glass shatters on the floor. A rock is thrown through a window. A child smashes his piggy bank. Dramatic moments like these in an animated movie or video game or some future virtual reality won't seem realistic unless the sound matches the action.

Cornell computer scientists are developing technology to synthesize the sounds that go with computer-animated images of brittle materials being smashed. Their methods look at the computer graphic model that underlies the animation, figure out how a corresponding real object would vibrate when fractured, and how that vibration would create sound.

For years, filmmakers have dubbed in recorded sound, but it is difficult to get it to match the action. And in a game or virtual reality, programmers can't know in advance just how hard or far a wine glass will fall.

"We'll compute motion and appearance and sound in an integrated way," explained Doug James, associate professor of computer science. "We won't just compute motion and appearance and have the sound as something you bolt on afterward."

James and graduate student Changxi Zheng presented their work at the SIGGRAPH 2010 conference in Los Angeles July 25-29. It follows previous work in which James and his students created sounds of dripping and splashing water and the clattering falls of such thin-walled objects as garbage cans and plastic bottles.

When a rigid object is struck or hits the floor, it can be deformed until the stress exceeds its strength, and then it shatters, releasing the energy stored by the deformation. Research shows that the sound comes mainly from the way all the little pieces vibrate just after the break, rather than from the whole object in the instant of fracture.

The computer calculates how each shard will vibrate when given the amount of energy stored by the deformation. The calculation takes into account how far the object was dropped or how hard it was thrown to determine the amount of energy available. It assumes that more fracture will occur in areas that have been strained the most, creating more, smaller pieces.

In most cases, the initial smash is followed by the scattering of debris on the floor. To accelerate computation of those sounds, the sound synthesis program can treat each irregularly shaped shard as an ellipsoid of similar size and shape. Then it draws on preloaded "soundbanks" -- not recorded sounds, but computer routines for calculating the vibration of ellipsoids of various sizes and materials.

To refine their procedures, the researchers smashed real objects and photographed them with high-speed, slow-motion cameras and recorded the sounds, then compared the actual sounds with their computed simulations. To demonstrate the results, they created videos of the smashing of a wine glass, a dinner plate, a glass table filled with dinnerware and a piggy bank full of coins. See for examples.

All of this is still an approximation of the real thing, James admitted, but it's a start, he said, and one that needs to be done now to make ready for the coming of new, more powerful systems.

"This is the first time anybody's ever built computer-synthesized models of these events with sound," he said. "Everything after this will be better. The future's going to be very different. Computers will be a thousand times as fast. It will be insane."

(Photo: Doug James Lab.)



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A new vaccine-delivery patch based on hundreds of microscopic needles that dissolve into the skin could allow persons without medical training to painlessly administer vaccines -- while providing improved immunization against diseases such as influenza.

Patches containing micron-scale needles that carry vaccine with them as they dissolve into the skin could simplify immunization programs by eliminating the use of hypodermic needles -- and their "sharps" disposal and re-use concerns. Applied easily to the skin, the microneedle patches could allow self-administration of vaccine during pandemics and simplify large-scale immunization programs in developing nations.

Details of the dissolving microneedle patches and immunization benefits observed in experimental mice were reported July 18th in the advance online publication of the journal Nature Medicine. Conducted by researchers from Emory University and the Georgia Institute of Technology, the study is believed to be the first to evaluate the immunization benefits of dissolving microneedles. The research was supported by the National Institutes of Health (NIH).

"In this study, we have shown that a dissolving microneedle patch can vaccinate against influenza at least as well, and probably better than, a traditional hypodermic needle," said Mark Prausnitz, a professor in the Georgia Tech School of Chemical and Biomolecular Engineering.

Just 650 microns in length and assembled into an array of 100 needles for the mouse study, the dissolving microneedles penetrate the outer layers of skin. Beyond their other advantages, the dissolving microneedles appear to provide improved immunity to influenza when compared to vaccination with hypodermic needles.

"The skin is a particularly attractive site for immunization because it contains an abundance of the types of cells that are important in generating immune responses to vaccines," said Richard Compans, professor of microbiology and immunology at Emory University School of Medicine.

In the study, one group of mice received the influenza vaccine using traditional hypodermic needles injecting into muscle; another group received the vaccine through dissolving microneedles applied to the skin, while a control group had microneedle patches containing no vaccine applied to their skin. When infected with influenza virus 30 days later, both groups that had received the vaccine remained healthy while mice in the control group contracted the disease and died.

Three months after vaccination, the researchers also exposed a different group of immunized mice to flu virus and found that animals vaccinated with microneedles appeared to have a better "recall" response to the virus and thus were able to clear the virus from their lungs more effectively than those that received vaccine with hypodermic needles.

"Another advantage of these microneedles is that the vaccine is present as a dry formulation, which will enhance its stability during distribution and storage," said Ioanna Skountzou, an Emory University assistant professor.

Pressed into the skin, the microneedles quickly dissolve in bodily fluids, leaving only the water-soluble backing. The backing can be discarded because it no longer contains any sharps.

"We envision people getting the patch in the mail or at a pharmacy and then self administering it at home," said Sean Sullivan, the study’s lead author from Georgia Tech. "Because the microneedles on the patch dissolve away into the skin, there would be no dangerous sharp needles left over."

The microneedle arrays were made from a polymer material, poly-vinyl pyrrolidone, that has been shown to be safe for use in the body. Freeze-dried vaccine was mixed with the vinyl-pyrrolidone monomer before being placed into microneedle molds and polymerized at room temperature using ultraviolet light.

In many parts of the world, poor medical infrastructure leads to the re-use of hypodermic needles, contributing to the spread of diseases such as HIV and hepatitis B. Dissolving microneedle patches would eliminate re-use while allowing vaccination to be done by personnel with minimal training.

Though the study examined only the administration of flu vaccine with the dissolving microneedles, the technique should be useful for other immunizations. If mass-produced, the microneedle patches are expected to cost about the same as conventional needle-and-syringe techniques, and may lower the overall cost of immunization programs by reducing personnel costs and waste disposal requirements, Prausnitz said.

Before dissolving microneedles can be made widely available, however, clinical studies will have to be done to assure safety and effectiveness. Other vaccine formulation techniques may also be studied, and researchers will want to better understand why vaccine delivery with dissolving microneedles has been shown to provide better protection.

Beyond those already mentioned, the study involved Jeong-Woo Lee, Vladimir Zarnitsyn, Seong-O Choi and Niren Murthy from Georgia Tech, and Dimitrios Koutsonanos and Maria del Pilar Martin from Emory University.

"The dissolving microneedle patch could open up many new doors for immunization programs by eliminating the need for trained personnel to carry out the vaccination," Prausnitz said. "This approach could make a significant impact because it could enable self-administration as well as simplify vaccination programs in schools and assisted living facilities."

(Photo: GIT)

Georgia Institute of Technology


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Your facial expression may tell the world what you are thinking or feeling. But it also affects your ability to understand written language related to emotions, according to research published in the July issue of Psychological Science, a journal of the Association for Psychological Science.

The new study reported on 40 people who were treated with botulinum toxin, or Botox. Tiny applications of this powerful nerve poison were used to deactivate muscles in the forehead that cause frowning.

The interactions of facial expression, thoughts, and emotions have intrigued scientists for more than a century, says the study's first author, University of Wisconsin-Madison psychology Ph.D. candidate David Havas.

Scientists have found that blocking the ability to move the body causes changes in cognition and emotion, but there were always questions. (One of the test treatments caused widespread, if temporary, paralysis.) In contrast, Havas was studying people after a pinpoint treatment to paralyze a single pair of "corrugator" muscles, which cause brow-wrinkling frowns.

To test how blocking a frown might affect comprehension of language related to emotions, Havas asked the patients to read written statements, before and then two weeks after the Botox treatment. The statements were angry ("The pushy telemarketer won't let you return to your dinner"), sad ("You open your e-mail in-box on your birthday to find no new e-mails") or happy ("The water park is refreshing on the hot summer day.").

Havas gauged the ability to understand these sentences according to how quickly the subject pressed a button to indicate they had finished reading it. "We periodically checked that the readers were understanding the sentences, not just pressing the button," says Havas.

The results showed no change in the time needed to understand the happy sentences. But after Botox treatment, the subjects took more time to read the angry and sad sentences. Although the time difference was small, it was significant, he adds. Moreover, the changes in reading time couldn't be attributed to changes in participants' mood.

The use of Botox to test how making facial expressions affect emotional centers in the brain was pioneered by Andreas Hennenlotter of the Max Planck Institute in Leipzig, Germany.

"There is a long-standing idea in psychology called the facial feedback hypothesis," says Havas. "Essentially, it says, when you're smiling, the whole world smiles with you. It's an old song, but it's right. Actually, this study suggests the opposite: When you're not frowning, the world seems less angry and less sad."

The Havas study broke new ground by linking the expression of emotion to the ability to understand language, says Havas' adviser, UW-Madison professor emeritus of psychology Arthur Glenberg. "Normally, the brain would be sending signals to the periphery to frown, and the extent of the frown would be sent back to the brain. But here, that loop is disrupted, and the intensity of the emotion and of our ability to understand it when embodied in language is disrupted."

Practically, the study "may have profound implications for the cosmetic-surgery," says Glenberg. "Even though it's a small effect, in conversation, people respond to fast, subtle cues about each other's understanding, intention and empathy. If you are slightly slower reacting as I tell you about something made me really angry, that could signal to me that you did not pick up my message."

Such an effect could snowball, Havas says, but the outcome could also be positive: "Maybe if I am not picking up sad, angry cues in the environment that will make me happier."

In theoretical terms, the finding supports a psychological hypothesis called "embodied cognition," says Glenberg, now a professor of psychology at Arizona State University. "The idea of embodied cognition is that all our cognitive processes, even those that have been thought of as very abstract, are actually rooted in basic bodily processes of perception, action and emotion."

With some roots in evolutionary theory, the embodied cognition hypothesis suggests that our thought processes, like our emotions, are refined through evolution to support survival and reproduction.

Embodied cognition links two seemingly separate mental functions, Glenberg says. "It's been speculated at least since Darwin that the peripheral expression of emotion is a part of the emotion. An important role of emotion is social: It communicates 'I love you' or 'I hate you,' and it makes sense that there would be this very tight connection between peripheral expression and brain mechanism."

"Language has traditionally been seen as a very high-level, abstract process that is divorced from more primitive processes like action, perception and emotion," Havas says. "This study shows that far from being divorced from emotion, language understanding can be hindered when those peripheral bodily mechanism are interrupted."

Association for Psychological Science


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In the battle between insect predators and their prey, chemical signals called kairomones serve as an early-warning system. Pervasively emitted by the predators, the compounds are detected by their prey, and can even trigger adaptations, such a change in body size or armor, that help protect the prey. But as widespread as kairomones are in the insect world, their chemical identity has remained largely unknown.

New research by Rockefeller University’s Joel E. Cohen and colleagues at the University of Haifa in Israel has identified two compounds emitted by mosquito predators that make the mosquitoes less inclined to lay eggs in pools of water. The findings, published in the July issue of Ecology Letters, may provide new environmentally friendly tactics for repelling and controlling disease-carrying insects.

Many animals use chemicals to communicate with each other. Pheromones, which influence social and reproductive behaviors within a particular species, are probably the best known and studied. Kairomones are produced by an individual of one species and received by an individual of a different species, with the receiving species often benefiting at the expense of the donor.

Cohen and his Israeli colleagues focused on the interaction between two insect species found in temporary pools of the Mediterranean and the Middle East: larvae of the mosquito C. longiareolata and its predator, the backswimmer N. maculata. When the arriving female mosquitoes detect a chemical emitted by the backswimmer, they are less likely to lay eggs in that pool.

To reproduce conditions of temporary pools in the field, the researchers used aged tap water with fish food added as a source of nutrients. Individual backswimmers were then placed in vials containing samples of the temporary pools, and air samples were collected from the headspace within the vials. The researchers used gas chromatography-mass spectrometry to analyze the chemicals emitted by the backswimmers.

Cohen and his colleagues identified two chemicals, hydrocarbons called n-heneicosane and n-tricosane, which repelled egg-laying by mosquitoes at the concentrations of those compounds found in nature. Together, the two chemicals had an additive effect.

Since the mosquitoes can detect the backswimmer’s kairomones from above the water’s surface, predator-released kairomones can reduce the mosquito’s immediate risk of predation, says Cohen. But they also increase the female mosquito’s chance of dying from other causes before she finds a pool safe for her to lay her eggs in. “That’s why we think these chemicals could be a useful part of a strategy to control the population size of mosquitoes,” says Cohen, who is the Abby Mauzé Rockefeller Professor and head of the Laboratory of Populations.“We started this work from very basic curiosity about how food webs and predator-prey interactions work, but we now see unexpected practical applications.”

“These newly identified compounds, and others that remain to be discovered, might be effective in controlling populations of disease-carrying insects. It’s far too soon to say, but there’s the possibility of an advance in the battle against infectious disease.”

(Photo: Rockefeller U.)

Rockefeller University


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New research indicates that the interactions of microscopic organisms around a particular organic material may alter the chemical properties of the ocean--influencing global climate by affecting cloud formation in the atmosphere.

Justin Seymour, a research fellow at the University of Technology Sydney, is the lead author of a paper reporting the results, published in this week's issue of the journal Science.

The paper describes how a relative of the chemical that seabirds and seals use to locate prey, dimethylsulfide (DMS), may serve a similar purpose at the microbial scale, helping marine microorganisms find food and cycle chemicals that are important to climate.

"These scientists have used impressive technology to study interactions between organisms and their chemical environment at the scales they actually take place," said David Garrison, director of the National Science Foundation (NSF)'s biological oceanography program, which funded the research.

"The research will give us new insights on the workings of microbial assemblages in nature."

Seymour agrees. "We found that ecological interactions and behavioral responses taking place within volumes of a fraction of a drop of seawater can ultimately influence important ocean chemical cycling processes."

Using microfluidic technology, the team of researchers, led by Roman Stocker of the Massachusetts Institute of Technology, recorded microbes swimming toward the chemical dimethylsulfoniopropionate (DMSP) as it was released into a tiny channel occupied by the microbes.

The fact that the microbes actively moved toward the DMSP indicates that the tiny organisms play a role in ocean sulphur and carbon cycles, which exert a powerful influence on Earth's climate.

How fast the microorganisms consume DMSP--rather than converting it into DMS--is important because DMS is involved in the formation of clouds in the atmosphere.

This in turn affects the heat balance of the atmosphere.

Seymour, Stocker, Rafel Simó of the Institute for Marine Sciences in Barcelona, and MIT graduate student Tanvir Ahmed carried out the research in Stocker's MIT laboratory.

The study is the first to make a visual record of microbial behaviour in the presence of DMSP.

"It's important to be able to directly look at an environment in order to understand its ecology," Stocker said.

"We can now visualize the behavior of marine microorganisms much like ecologists have done with macro-organisms for a long time."

To accomplish this, the team recreated a microcosm of the ocean environment using a microfluidic device about the size of a flash drive with minuscule channels engraved in a clear rubbery material.

The scientists injected DMSP into the channel in a way that mimics the bursting of an algal cell after viral infection--a common event in the ocean--then, using a camera attached to a microscope, they recorded whether and how microbes swam toward the chemical.

The researchers found that some marine microbes, including bacteria, are attracted to DMSP because they feed on it, whereas others are drawn to the chemical because it signals the presence of prey.

This challenges previous theories that this chemical might be a deterrent against predators.

"Our observations clearly show that, for some plankton, DMSP acts as an attractant towards prey rather than a deterrent," said Simó.

"By simulating the microscale patches of the chemical cue and directly monitoring the swimming responses of the predators towards these patches, we get a much more accurate perception of these important ecological interactions than can be obtained from traditional bulk approaches."

The research also indicates that marine microorganisms have at least one behavioral characteristic in common with larger sea and land animals: we're all drawn to food.

In next steps, the team plans to extend the research from the laboratory to the ocean environment.

The scientists are working on an experimental system that can be used on oeanographic ships working with bacteria collected directly from the ocean.

The research was also funded by the Australian Research Council, the Spanish Ministry of Science and Innovation, La Cambra de Barcelona, and the Hayashi Fund at MIT.

(Photo: Roman Stocker and Tanvir Ahmed)

National Science Foundation




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