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News Article | December 1, 2016
Site: www.eurekalert.org

Researchers from the University of São Paulo have produced a tool for reference labs to assist epidemiological surveillance by analyzing clinical samples from patients with suspected infection by dengue, Zika, chikungunya and many other viral agent Researchers from the University of São Paulo (USP) at Ribeirão Preto in Brazil have developed a platform that analyzes clinical samples from patients to diagnose infection by 416 viruses found in the world's tropical regions. According to its creators, the tool can be used by reference laboratories such as Adolfo Lutz Institute, Oswaldo Cruz Foundation (Fiocruz) and Evandro Chagas Institute in Brazil to assist epidemiological surveillance by detecting pathogens with the potential to cause epidemics in humans. Results of the research project, which was coordinated by Victor Hugo Aquino, a professor at the University of São Paulo's Ribeirão Preto Pharmaceutical School (FCFRP-USP), and supported by FAPESP, have been published in PLoS Neglected Tropical Diseases. "The number of patients with suspected dengue, Zika or chikungunya infection will increase when summer arrives," said Aquino, lead author of the article. "Conventional methods are frequently unable to confirm diagnosis of these diseases, so we don't know which viruses are circulating." In his view, if a tool like this had been available when Zika began circulating in Brazil, it might have been possible to restrict its spread to the initial outbreak location. "We took a long time to realize an epidemic was under way because no one was thinking of Zika at the time," he said. In addition to the pathogens, the platform detects others that as yet have been identified only sporadically but could become epidemics. Examples include Mayaro, an alphavirus related to chikungunya that is transmitted by wild mosquitoes such as Haemagogus janthinomys, and Oropouche, which to date has caused epidemics confined to riverine communities in the Amazon region and is transmitted mainly by midges of the species Culicoides paraensis. "There are several other viruses that haven't yet caused problems in humans but may do so one day," Aquino said. "They're evolving all the time, and with the degradation of natural environments infectious agents once confined to natural niches could spread farther afield." Although the platform is designed above all to detect pathogens transmitted by arthropods such as mosquitoes and ticks, it can also diagnose infectious agents transmitted by small mammals, like hantavirus. Aquino explained that the selection encompasses all viruses occurring in tropical regions with DNA sequences deposited in GenBank, a public database maintained by the National Center for Biotechnology Information (NCBI), which is part of the United States National Library of Medicine (NLM). The platform consists of a DNA microarray slide with eight identical sub-arrays containing viral probes replicated at least three times to complete the array with 15,000 probes. Each probe contains the sequences for 60 nucleotides that are complementary to the genomes of the viruses to be detected. According to Aquino, the sequences were mounted on the basis of information from GenBank using bioinformatics. "If a blood sample contains one of the 416 viruses included on the microchip, the pathogen's genome will bind with one of the probes to produce a marker that can be detected by a scanner," Aquino said. The device that reads the results is the same as that used in microarray assays for the analysis of gene expression. "Initially, the test will not be for the entire population because of high cost," Aquino said. "It will be used on patients with suspected dengue, Zika or other febrile diseases whose diagnosis isn't confirmed by conventional methods." The methodology was validated using 20 viruses available at FCFRP-USP's Virology Laboratory. The validation tests did not point to cross-hybridization, which produces a positive result for more than one infectious agent and hinders correct identification of single viruses. Nevertheless, the method proved effective to diagnose cases of co-infection, such as when the same patient has been infected by both Zika and dengue.


News Article | December 7, 2016
Site: www.eurekalert.org

Ayahuasca is a beverage that has been used for centuries by Native South-Americans. Studies suggest that it exhibits anxiolytic and antidepressant effects in humans. One of the main substances present in the beverage is harmine, a beta-carboline which potential therapeutic effects for depression has been recently described in mice. "It has been shown in rodents that antidepressant medication acts by inducing neurogenesis. So we decided to test if harmine, an alkaloid with the highest concentration in the psychotropic plant decoction ayahuasca, would trigger neurogenesis in human neural cells", said Vanja Dakic, PhD student and one of the authors in the study. In order to elucidate these effects, researchers from the D'Or Institute for Research and Education (IDOR) and the Institute of Biomedical Sciences at the Federal University of Rio de Janeiro (ICB-UFRJ) exposed human neural progenitors to this beta-carboline. After four days, harmine led to a 70% increase in proliferation of human neural progenitor cells. Researchers were also able to identify how the human neural cells respond to harmine. The described effect involves the inhibition of DYRK1A, which is located on chromosome 21 and is over activated in patients with Down syndrome and Alzheimer's Disease. "Our results demonstrate that harmine is able to generate new human neural cells, similarly to the effects of classical antidepressant drugs, which frequently are followed by diverse side effects. Moreover, the observation that harmine inhibits DYRK1A in neural cells allows us to speculate about future studies to test its potential therapeutic role over cognitive deficits observed in Down syndrome and neurodegenerative diseases", suggests Stevens Rehen, researcher from IDOR and ICB-UFRJ. This study, published Dec. 6 in PeerJ, was funded by Brazilian funding agencies FAPERJ, CNPq, CAPES, FINEP, BNDES e FAPESP.


News Article | October 26, 2016
Site: phys.org

New species of dragonfly named Erythrodiplax ana has brown spots on its wingtips and a waxy body coating. Credit: Rhainer Guillermo Ferreira A new species of dragonfly with a brown spot on each of its four wingtips and a bluish waxy body coating has been described by Brazilian researchers in an article published in the scientific journal Zootaxa. Found in 2011 near a spring on the Itororó Ecological Reserve in Uberlândia, Minas Gerais State, Brazil, it has been named Erythrodiplax ana. The new species was identified during the PhD research of Rhainer Guillermo Ferreira, that was supported by a scholarship from FAPESP during his postdoctoral research. "The discovery is important above all because of the site where the species was found," said Ferreira, first author of the article and assistant professor at the Federal University of São Carlos's Center for Biological & Health Sciences (CCBS-UFSCar). "The nature reserve contains a vereda, a palm swamp wetland that provides part of Uberlândia's water supply. The discovery of a new species in an urban area and with a habitat linked to a spring used to draw off water shows how little we know of Brazil's biodiversity," he told. He added that dragonflies are natural predators of flies and important environmental indicators. "When you find these insects in the wild near a watercourse, it means the water's good," he said. Between 2011 and 2014, the researchers compared the blue dragonfly's morphology with those of 57 other species in the same genus. At the end of the period, they confirmed its status as a new species and began working on a description. A combination of two traits distinguishes E. ana from other species in the genus. Particularly important is that the male's body is covered with bluish wax. The female does not produce wax and is ochraceous (yellowish-orange). "Males of several species in this genus produce wax," Ferreira said. "Some have wax only on their wings, which are bright blue." Another key trait of E. ana is the brown spot on each wingtip, which is rare in this genus. Ferreira is investigating whether the wax serves as a kind of sunscreen to protect the male's body from solar radiation since the insect is exposed to sunlight for many hours every day. Previous studies evaluated the properties of the wax found in other species and concluded that the blue coloring serves to reflect the sun's ultraviolet rays, he noted. The researchers believe E. ana is characteristic of wetlands in the Cerrado (savanna) biome. Besides the Uberlândia reserve, it was also found by the group in Chapada dos Guimarães National Park, Mato Grosso State. Explore further: New blind and rare planthopper species and genus dwells exclusively in a Brazilian cave


News Article | October 26, 2016
Site: www.eurekalert.org

A new species of dragonfly with a brown spot on each of its four wingtips and a bluish waxy body coating has been described by Brazilian researchers in an article published in the scientific journal Zootaxa. Found in 2011 near a spring on the Itororó Ecological Reserve in Uberlândia, Minas Gerais State, Brazil, it has been named Erythrodiplax ana. The new species was identified during the PhD research of Rhainer Guillermo Ferreira, that was supported by a scholarship from FAPESP during his postdoctoral research. "The discovery is important above all because of the site where the species was found," said Ferreira, first author of the article and assistant professor at the Federal University of São Carlos's Center for Biological & Health Sciences (CCBS-UFSCar). "The nature reserve contains a vereda, a palm swamp wetland that provides part of Uberlândia's water supply. The discovery of a new species in an urban area and with a habitat linked to a spring used to draw off water shows how little we know of Brazil's biodiversity," he told. He added that dragonflies are natural predators of flies and important environmental indicators. "When you find these insects in the wild near a watercourse, it means the water's good," he said. Between 2011 and 2014, the researchers compared the blue dragonfly's morphology with those of 57 other species in the same genus. At the end of the period, they confirmed its status as a new species and began working on a description. A combination of two traits distinguishes E. ana from other species in the genus. Particularly important is that the male's body is covered with bluish wax. The female does not produce wax and is ochraceous (yellowish-orange). "Males of several species in this genus produce wax," Ferreira said. "Some have wax only on their wings, which are bright blue." Another key trait of E. ana is the brown spot on each wingtip, which is rare in this genus. Ferreira is investigating whether the wax serves as a kind of sunscreen to protect the male's body from solar radiation since the insect is exposed to sunlight for many hours every day. Previous studies evaluated the properties of the wax found in other species and concluded that the blue coloring serves to reflect the sun's ultraviolet rays, he noted. The researchers believe E. ana is characteristic of wetlands in the Cerrado (savanna) biome. Besides the Uberlândia reserve, it was also found by the group in Chapada dos Guimarães National Park, Mato Grosso State. In addition to Ferreira, the co-authors of the article are Ferreira's PhD supervisor, Pitágoras C. Bispo, a researcher at São Paulo State University (UNESP) at Assis; Diogo S. Vilela, affiliated with the University of São Paulo (USP) at Ribeirão Preto; and Kleber Del-Claro, affiliated with the Federal University of Uberlândia (UFU).


News Article | October 26, 2016
Site: www.eurekalert.org

UPTON, NY - Understanding how tiny particles emitted by cars and factories affect Earth's climate requires accurate climate modeling and the ability to quantify the effects of these pollutant particles vs. particles naturally present in the atmosphere. One large uncertainty is what Earth was like before these industrial-era emissions began. In a paper just published in Nature, scientists collaborating on the GoAmazon study describe how they tracked particles in the largely pristine atmosphere over the Amazon rainforest, which has given them a way to effectively turn back the clock a few hundred years. The scientists, sponsored in part by the U.S. Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and DOE's Atmospheric System Research Program, collected and analyzed data over the Amazon during 2014-15. By scanning the skies at different altitudes and measuring the changes in particle population over time, the scientists figured out the source of the tiny particles that trigger cloud formation under "pre-industrial" conditions. The analysis described in the Nature paper, led by scientists from DOE's Brookhaven National Laboratory, reveals that in the skies above the Amazon, large numbers of small aerosol particles that form naturally in the upper atmosphere are carried to the lower atmosphere, known as the "boundary layer," by rapid downdrafts associated with rainfall. Then, in the boundary layer, where volatile organic compounds emitted by trees react with oxidants, the oxidation products condense on these small particles and make them grow into the "nuclei" around which clouds form. "In many other places we know that these cloud-forming particles are coming directly from emissions from cars and factories, or formed as industrial gas molecules condense to form new particles," said Brookhaven Lab atmospheric chemist Jian Wang, one of the leaders of the study. "But in the Amazon, there are clean conditions-no cars, no factories-which means we can study this pristine environment to see what Earth was like before the industrial era in order to quantify what the change is. Our measurements will improve how these key atmospheric processes are represented in climate models." Most clouds-the ones that produce shade and high reflectivity and have the biggest potential impact on climate-form near Earth's surface. In the Amazon, the process starts with particles measuring about 20 to 40 nanometers in diameter. At ground level, these small particles grow by condensation of oxidized organics to the size needed to seed the formation of clouds as they rise in the atmosphere, Wang explained. "Studies show that no new particle formation happens in the boundary layer, the lowest part of the atmosphere," Wang said. "Plus, it rains a lot in the Amazon, and rain washes lots of particles out of the boundary layer." In the absence of the industrial sources, and with all the rain, where are the small particles in the Amazon boundary layer coming from? The GoAmazon scientists hypothesized that the particles might be coming from higher up in the atmosphere, where cold temperatures make it much easier for vapor molecules to condense and form tiny particles. But how do they get down to the boundary layer? To find out, the scientists measured the numbers and sizes of particles at various altitudes above a pristine region of the Amazon rainforest using a DOE ARM Climate Research Facility research aircraft operated by Pacific Northwest National Laboratory. The aircraft was outfitted with aerosol sampling equipment and instruments for tracking key meteorological variables. These tools included a Fast Integrated Mobility Spectrometer designed and built at Brookhaven that could make aerosol measurements rapidly, which was absolutely essential given the speed of the aircraft. "We conducted several flights, starting in the boundary layer to altitudes of 2,000 to 3,000 meters, climbing level by level into the 'lower free troposphere'-5 to 6 kilometers above the surface," Wang said. The instruments measured a high concentration of small, 20-40 nanometer diameter particles in the lower free troposphere. At lower altitudes the size distribution flipped, with a higher concentration of larger particles measuring at least 100 nanometers in diameter found closer to Earth. The scientists also gathered data from ground instruments set up and maintained by collaborators from Germany and Brazil, and cloud radar measurements from an ARM mobile facility. These data allowed them to monitor how the particles at ground level changed after rainfall, and measure how air masses move as a storm passes by. Before a rainstorm, Wang said, the ground instruments measured a lot of big particles and few small. "After the rain, we have the opposite: The big particles were 'rained out'-but at the same time we see a lot of small particles appear at ground level, just like those the G-1 had measured in the lower free troposphere." These observations were backed up by estimates based on the radar data of how much air (and how many particles) should move from layer to layer in the downdrafts associated with the rain. Additional detailed statistical analyses confirmed that rapid, sporadic downdrafts associated with precipitation carried sufficient numbers of small particles from the lower free troposphere to the boundary layer to create a fresh population of the particles that would eventually seed the formation of new clouds after each rainstorm. "This sounds like a simple story, but you could not get to these conclusions with just a single measurement," said Wang. "We needed all the collaborators conducting these simultaneous measurements in all these places-the layers of the atmosphere, the radar, and on the ground-to fit it all together." The implications, he added, may go beyond the tropics and relate to many continental sites 200-300 years ago, in the pre-industrial era. "We have plenty of experiments making measurements of the atmosphere today. That's much better understood compared to what we know about how things were 300 years ago. But with this study, we now have measurements we can use as a baseline that will help us understand the effects of industrialization." The GoAmazon field campaign was led in the U.S. by Harvard University and in Brazil by a consortium of Brazilian and German research groups. Scientists from Finland and Sweden also participated in the study. The ARM Climate Research Facility is a DOE Office of Science User Facility. The research was funded by the DOE Office of Science; the Amazonas State Research Foundation (FAPEAM); the São Paulo Research Foundation (FAPESP); the Brazil Scientific Mobility Program; the German Max Planck Society; and the German Federal Ministry of Education and Research. The ARM Facility is operated by nine Department of Energy national laboratories including Brookhaven Lab and the Pacific Northwest National Laboratory. Brookhaven National Laboratory is supported by the Office of Science of the U.S. Department of Energy. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov. One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit applied science and technology organization.


News Article | November 16, 2016
Site: phys.org

The images enabled the astronomers to observe unexpected new structures in the binary system, including a region between the two stars in which extremely high-velocity stellar winds are colliding. "With these observations, we were able to map the zone in which the two stellar winds collide and make sure we genuinely understand the basic parameters of the binary system," said Augusto Damineli, Full Professor at the University of São Paulo's Institute of Astronomy, Geophysics & Atmospheric Sciences (IAG-USP) in Brazil. Damineli has studied mysterious phenomena involving Eta Carinae for more than 20 years with FAPESP's support and is one of the three Brazilian authors of the paper published by Astronomy & Astrophysics. The other two are Mairan Macedo Teodoro, a researcher at NASA's Goddard Space Flight Center, and José Henrique Groh de Castro Moura, a professor at Trinity College Dublin in Ireland. According to the researchers, the Eta Carinae binary pair are so massive and bright that the radiation they produce rips atoms off their surfaces and spews them into space. This expulsion of atomic material is referred to as stellar wind. The raging winds from Eta Carinae are much faster and denser than the solar wind streaming off our own Sun. They collide violently in the zone between the two stars at speeds that can reach 10 million km per hour. The combined effect of the two stellar winds as they smash into each other at extreme speeds is to create temperatures of millions of degrees and intense deluges of X-ray radiation. The central area where the raging winds collide is so comparatively tiny that telescopes in space and on the ground have not been able to image them in detail - until now. Utilizing an advanced new imaging technique called infrared long baseline interferometry, which combines light beams collected from the same astronomic object by several telescopes to analyze it in great detail, the researchers were able to observe the turbulent collision zone for the first time. They did this with the Astronomical Multi-Beam Recombiner known as AMBER, an instrument currently installed on the Very Large Telescope Interferometer (VLTI) at the European Southern Observatory's Paranal Facility in Chile's Atacama Desert. They used three of the VLT's four auxiliary telescopes, each with a diameter of 1.8 m and mounted on tracks so that they can move up to 200 m apart. Image sharpness increases with telescope separation, so the astronomers were able to achieve a tenfold increase in resolving power compared with one of the VLT array's main telescopes, delivering for the first time direct images 50,000 times finer than human vision of both the wind that swirls around Eta Carinae's primary star and the wind collision zone between the two stars. Using the Doppler effect, which enables astronomers to calculate precisely how fast stars and other astronomical objects are moving toward or away from Earth, they obtained images of the stellar winds at different velocities, measuring velocities and densities to compare them with a computer model of the collision. "The images we obtained via the Doppler effect show the stellar winds colliding at different velocities," Damineli said. "So we were able to use them to reconstruct the shape of the walls of the cavity formed by the collision shockwave from its apex to the most distant regions." The researchers also observed in the images an unexpected fan-shaped structure where the raging wind from the smaller, hotter star crashes into the denser wind from the larger of the pair. The wind from the secondary star is less dense but much fiercer than the wind from the primary star, reaching velocities of 3,000 km per second, they estimated. On the basis of these stellar wind velocities, they hope to be able to create more accurate computer models of Eta Carinae's internal structure and increase their understanding of how extremely massive stars lose mass as they evolve. "Because light from the secondary star is 200-300 times weaker than light from the primary, we couldn't see it directly with AMBER," Damineli said. "We should be able to do so with GRAVITY, a new VLTI instrument due to come on stream soon." GRAVITY is an interferometric instrument operating in the K band and combining four telescope beams. Its higher resolution will enable the astronomers to obtain interferometric images of astronomic objects with even greater precision and over a wider range of wavelengths. According to Damineli, they may succeed in tracking Eta Carinae's secondary star from point to point along its 5.5-year orbit and plotting its ellipse. "When we've done that we'll at last be able to 'weigh' the secondary star. Mass is a star's most fundamental parameter," he said. Explore further: Deep-space images show violent wind collision in one of the heaviest stars in our galaxy


News Article | December 20, 2016
Site: www.eurekalert.org

Researchers develop a novel route to synthesize melanin, the primary pigment in mammals, and to facilitate its use in sensors and other applications Bioelectronics, sometimes called the next medical frontier, is a research field that combines electronics and biology to develop miniaturized implantable devices capable of altering and controlling electrical signals in the human body. Large corporations are increasingly interested: a joint venture in the field has recently been announced by Alphabet, Google's parent company, and pharmaceutical giant GlaxoSmithKline (GSK). One of the challenges that scientists face in developing bioelectronic devices is identifying and finding ways to use materials that conduct not only electrons but also ions, as most communication and other processes in the human organism use ionic biosignals (e.g., neurotransmitters). In addition, the materials must be biocompatible. Resolving this challenge is one of the motivations for researchers at São Paulo State University's School of Sciences (FC-UNESP) at Bauru in Brazil. They have succeeded in developing a novel route to more rapidly synthesize and to enable the use of melanin, a polymeric compound that pigments the skin, eyes and hair of mammals and is considered one of the most promising materials for use in miniaturized implantable devices such as biosensors. "All the materials that have been tested to date for applications in bioelectronics are entirely synthetic," said Carlos Frederico de Oliveira Graeff, a professor at UNESP Bauru and principal investigator for the project. "One of the great advantages of melanin is that it's a totally natural compound and biocompatible with the human body: hence its potential use in electronic devices that interface with brain neurons, for example." According to Graeff, the challenges of using melanin as a material for the development of bioelectronic devices include the fact that like other carbon-based materials, such as graphene, melanin is not easily dispersible in an aqueous medium, a characteristic that hinders its application in thin-film production. Furthermore, the conventional process for synthesizing melanin is complex: several steps are hard to control, it can last up to 56 days, and it can result in disorderly structures. In a series of studies performed in recent years at the Center for Research and Development of Functional Materials (CDFM), where Graeff is a leading researcher and which is one of the Research, Innovation and Dissemination Centers (RIDCs) funded by FAPESP, he and his collaborators managed to obtain biosynthetic melanin with good dispersion in water and a strong resemblance to natural melanin using a novel synthesis route. The process developed by the group at CDMF takes only a few hours and is based on changes in parameters such as temperature and the application of oxygen pressure to promote oxidation of the material. By applying oxygen pressure, the researchers were able to increase the density of carboxyl groups, which are organic functional groups consisting of a carbon atom double bonded to an oxygen atom and single bonded to a hydroxyl group (oxygen + hydrogen). This enhances solubility and facilitates the suspension of biosynthetic melanin in water. "The production of thin films of melanin with high homogeneity and quality is made far easier by these characteristics," Graeff said. By increasing the density of carboxyl groups, the researchers were also able to make biosynthetic melanin more similar to the biological compound. In living organisms, an enzyme that participates in the synthesis of melanin facilitates the production of carboxylic acids. The new melanin synthesis route enabled the researchers to mimic the role of this enzyme chemically while increasing carboxyl group density. "We've succeeded in obtaining a material that's very close to biological melanin by chemical synthesis and in producing high-quality film for use in bioelectronic devices," Graeff said. Through collaboration with colleagues at research institutions in Canada, the Brazilian researchers have begun using the material in a series of applications, including electrical contacts, pH sensors and photovoltaic cells. More recently, they have embarked on an attempt to develop a transistor, a semiconductor device used to amplify or switch electronic signals and electrical power. "Above all, we aim to produce transistors precisely in order to enhance this coupling of electronics with biological systems," Graeff said.


News Article | November 16, 2016
Site: www.eurekalert.org

An international team of researchers has imaged the giant binary star system in the greatest detail ever, observing unexpected new structures An international team of astronomers has imaged the Eta Carinae star system in the greatest detail ever. Eta Carinae is a colossal binary system that consists of two massive stars orbiting each other. It is found almost 8,000 light years from Earth within the Carina Nebula, a giant star-forming region in the Carina-Sagittarius Arm of the Milky Way. The images enabled the astronomers to observe unexpected new structures in the binary system, including a region between the two stars in which extremely high-velocity stellar winds are colliding. "With these observations, we were able to map the zone in which the two stellar winds collide and make sure we genuinely understand the basic parameters of the binary system," said Augusto Damineli, Full Professor at the University of São Paulo's Institute of Astronomy, Geophysics & Atmospheric Sciences (IAG-USP) in Brazil. Damineli has studied mysterious phenomena involving Eta Carinae for more than 20 years with FAPESP's support and is one of the three Brazilian authors of the paper published by Astronomy & Astrophysics. The other two are Mairan Macedo Teodoro, a researcher at NASA's Goddard Space Flight Center, and José Henrique Groh de Castro Moura, a professor at Trinity College Dublin in Ireland. According to the researchers, the Eta Carinae binary pair are so massive and bright that the radiation they produce rips atoms off their surfaces and spews them into space. This expulsion of atomic material is referred to as stellar wind. The raging winds from Eta Carinae are much faster and denser than the solar wind streaming off our own Sun. They collide violently in the zone between the two stars at speeds that can reach 10 million km per hour. The combined effect of the two stellar winds as they smash into each other at extreme speeds is to create temperatures of millions of degrees and intense deluges of X-ray radiation. The central area where the raging winds collide is so comparatively tiny that telescopes in space and on the ground have not been able to image them in detail - until now. Utilizing an advanced new imaging technique called infrared long baseline interferometry, which combines light beams collected from the same astronomic object by several telescopes to analyze it in great detail, the researchers were able to observe the turbulent collision zone for the first time. They did this with the Astronomical Multi-Beam Recombiner known as AMBER, an instrument currently installed on the Very Large Telescope Interferometer (VLTI) at the European Southern Observatory's Paranal Facility in Chile's Atacama Desert. They used three of the VLT's four auxiliary telescopes, each with a diameter of 1.8 m and mounted on tracks so that they can move up to 200 m apart. Image sharpness increases with telescope separation, so the astronomers were able to achieve a tenfold increase in resolving power compared with one of the VLT array's main telescopes, delivering for the first time direct images 50,000 times finer than human vision of both the wind that swirls around Eta Carinae's primary star and the wind collision zone between the two stars. Using the Doppler effect, which enables astronomers to calculate precisely how fast stars and other astronomical objects are moving toward or away from Earth, they obtained images of the stellar winds at different velocities, measuring velocities and densities to compare them with a computer model of the collision. "The images we obtained via the Doppler effect show the stellar winds colliding at different velocities," Damineli said. "So we were able to use them to reconstruct the shape of the walls of the cavity formed by the collision shockwave from its apex to the most distant regions." The researchers also observed in the images an unexpected fan-shaped structure where the raging wind from the smaller, hotter star crashes into the denser wind from the larger of the pair. The wind from the secondary star is less dense but much fiercer than the wind from the primary star, reaching velocities of 3,000 km per second, they estimated. On the basis of these stellar wind velocities, they hope to be able to create more accurate computer models of Eta Carinae's internal structure and increase their understanding of how extremely massive stars lose mass as they evolve. "Because light from the secondary star is 200-300 times weaker than light from the primary, we couldn't see it directly with AMBER," Damineli said. "We should be able to do so with GRAVITY, a new VLTI instrument due to come on stream soon." GRAVITY is an interferometric instrument operating in the K band and combining four telescope beams. Its higher resolution will enable the astronomers to obtain interferometric images of astronomic objects with even greater precision and over a wider range of wavelengths. According to Damineli, they may succeed in tracking Eta Carinae's secondary star from point to point along its 5.5-year orbit and plotting its ellipse. "When we've done that we'll at last be able to 'weigh' the secondary star. Mass is a star's most fundamental parameter," he said.


News Article | March 1, 2017
Site: www.eurekalert.org

Chocolate lovers could soon have a harder time satisfying their sweet tooth. Worldwide demand for this mouth-watering treat is outstripping the production of cocoa beans, its primary ingredient. But in a study published in the Journal of Agricultural and Food Chemistry, scientists report that compounds found in jackfruit seeds produce many of the same aromas as processed cocoa beans and are a potentially cheap, abundant substitute for use in chocolate manufacturing. Globally, farmers produce about 3.7 million tons of cocoa annually. This yield is not expected to increase significantly in the next decade, but estimates suggest that worldwide demand for these beans will grow to 4.5 million tons by 2020. To meet growing expectations, scientists are investigating alternative sources that can mimic chocolate's distinct aroma and flavor. One of these possibilities is jackfruit, a large tropical fruit found in South America, Asia, Africa and Australia. In some countries, its sweet-smelling seeds are boiled, steamed and roasted before eating, providing a cheap source of fiber, protein and minerals. But in Brazil, the largest cocoa producer in the Americas, jackfruit seeds are considered waste. Looking to put these waste seeds to better use, Fernanda Papa Spada, Jane K. Parker, Solange Guidolin, Canniatti Brazaca and colleagues sought to determine if any of the compounds within them could be used to produce chocolate aromas. The researchers made 27 jackfruit seed flours by acidifying or fermenting the seeds prior to drying. They roasted these flours for various times and temperatures using processes similar to those used to enhance the chocolaty flavor of cocoa beans. Using gas chromatography-mass spectrometry, the team identified several compounds from the jackfruit flours that are associated with chocolate aromas, including 3-methylbutanal, 2,3-diethyl-5-methylprazine and 2-phenylethyl acetate. They also asked volunteers to smell the jackfruit seed flours and describe the aromas. In contrast to the acidified flours, the fermented ones were described as having more positive attributes, such as caramel, hazelnut or fruity aromas. The researchers conclude that jackfruit seeds are capable of producing chocolate aromas and are a potential replacement for the aroma of cocoa powder or chocolate. The authors acknowledge funding from the National Council of Technological and Scientific and Research Foundation (FAPESP). The abstract that accompanies this study is available here. The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With nearly 157,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. ACS does not conduct research, but publishes and publicizes peer-reviewed scientific studies. Its main offices are in Washington, D.C., and Columbus, Ohio. To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.


News Article | December 20, 2016
Site: phys.org

One of the challenges that scientists face in developing bioelectronic devices is identifying and finding ways to use materials that conduct not only electrons but also ions, as most communication and other processes in the human organism use ionic biosignals (e.g., neurotransmitters). In addition, the materials must be biocompatible. Resolving this challenge is one of the motivations for researchers at São Paulo State University's School of Sciences (FC-UNESP) at Bauru in Brazil. They have succeeded in developing a novel route to more rapidly synthesize and to enable the use of melanin, a polymeric compound that pigments the skin, eyes and hair of mammals and is considered one of the most promising materials for use in miniaturized implantable devices such as biosensors. "All the materials that have been tested to date for applications in bioelectronics are entirely synthetic," said Carlos Frederico de Oliveira Graeff, a professor at UNESP Bauru and principal investigator for the project. "One of the great advantages of melanin is that it's a totally natural compound and biocompatible with the human body: hence its potential use in electronic devices that interface with brain neurons, for example." According to Graeff, the challenges of using melanin as a material for the development of bioelectronic devices include the fact that like other carbon-based materials, such as graphene, melanin is not easily dispersible in an aqueous medium, a characteristic that hinders its application in thin-film production. Furthermore, the conventional process for synthesizing melanin is complex: several steps are hard to control, it can last up to 56 days, and it can result in disorderly structures. In a series of studies performed in recent years at the Center for Research and Development of Functional Materials (CDFM), where Graeff is a leading researcher and which is one of the Research, Innovation and Dissemination Centers (RIDCs) funded by FAPESP, he and his collaborators managed to obtain biosynthetic melanin with good dispersion in water and a strong resemblance to natural melanin using a novel synthesis route. The process developed by the group at CDMF takes only a few hours and is based on changes in parameters such as temperature and the application of oxygen pressure to promote oxidation of the material. By applying oxygen pressure, the researchers were able to increase the density of carboxyl groups, which are organic functional groups consisting of a carbon atom double bonded to an oxygen atom and single bonded to a hydroxyl group (oxygen + hydrogen). This enhances solubility and facilitates the suspension of biosynthetic melanin in water. "The production of thin films of melanin with high homogeneity and quality is made far easier by these characteristics," Graeff said. By increasing the density of carboxyl groups, the researchers were also able to make biosynthetic melanin more similar to the biological compound. In living organisms, an enzyme that participates in the synthesis of melanin facilitates the production of carboxylic acids. The new melanin synthesis route enabled the researchers to mimic the role of this enzyme chemically while increasing carboxyl group density. "We've succeeded in obtaining a material that's very close to biological melanin by chemical synthesis and in producing high-quality film for use in bioelectronic devices," Graeff said. Through collaboration with colleagues at research institutions in Canada, the Brazilian researchers have begun using the material in a series of applications, including electrical contacts, pH sensors and photovoltaic cells. More recently, they have embarked on an attempt to develop a transistor, a semiconductor device used to amplify or switch electronic signals and electrical power. "Above all, we aim to produce transistors precisely in order to enhance this coupling of electronics with biological systems," Graeff said. Explore further: Skin pigment could help strengthen foams and fabrics

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