Your viral infection history in a single drop of blood

 

From a single drop of blood, researchers can now simultaneously test for more than 1,000 different strains of viruses that currently or have previously infected a person. New technology developed by Howard Hughes Medical Institute (HHMI) researchers makes it possible to test for current and past infections with any known human virus by analyzing a single drop of a person's blood. The method, called VirScan, is an efficient alternative to existing diagnostics that test for specific viruses one at a time. With VirScan, scientists can run a single test to determine which viruses have infected an individual, rather than limiting their analysis to particular viruses. That unbiased approach could uncover unexpected factors affecting individual patients' health, and also expands opportunities to analyze and compare viral infections in large populations. The comprehensive analysis can be performed for about $25 per blood sample. Stephen Elledge, an HHMI investigator at Brigham and Women's Hospital, led the development of VirScan. "We've developed a screening methodology to basically look back in time in people's [blood] sera and see what viruses they have experienced," he says. "Instead of testing for one individual virus at a time, which is labor intensive, we can assay all of these at once. It's one-stop shopping." Elledge and his colleagues have already used VirScan to screen the blood of 569 people in the United States, South Africa, Thailand, and Peru. The scientists described the new technology and reported their findings in the June 5, 2015, issue of the journal Science. VirScan works by screening the blood for antibodies against any of the 206 species of viruses known to infect humans. The immune system ramps up production of pathogen-specific antibodies when it encounters a virus for the first time, and it can continue to produce those antibodies for years or decades after it clears an infection. That means VirScan not only identifies viral infections that the immune system is actively fighting, but also provides a history of an individual's past infections. To develop the new test, Elledge and his colleagues synthesized more than 93,000 short pieces of DNA encoding different segments of viral proteins. They introduced those pieces of DNA into bacteria-infecting viruses called bacteriophage. Each bacteriophage manufactured one of the protein segments -- known as a peptide -- and displayed the peptide on its surface. As a group, the bacteriophage displayed all of the protein sequences found in the more than 1,000 known strains of human viruses. Antibodies in the blood find their viral targets by recognizing unique features known as epitopes that are embedded in proteins on the virus surface. To perform the VirScan analysis, all of the peptide-displaying bacteriophage are allowed to mingle with a blood sample. Antiviral antibodies in the blood find and bind to their target epitopes within the displayed peptides. The scientists then retrieve the antibodies and wash away everything except for the few bacteriophage that cling to them. By sequencing the DNA of those bacteriophage, they can identify which viral protein pieces were grabbed onto by antibodies in the blood sample. That tells the scientists which viruses a person's immune system has previously encountered, either through infection or through vaccination. Elledge estimates it would take about 2-3 days to process 100 samples, assuming sequencing is working optimally. He is optimistic the speed of the assay will increase with further development. To test the method, the team used it to analyze blood samples from patients known to be infected with particular viruses, including HIV and hepatitis C. "It turns out that it works really well," Elledge says. "We were in the sensitivity range of 95 to 100 percent for those, and the specificity was good -- we didn't falsely identify people who were negative. That gave us confidence that we could detect other viruses, and when we did see them we would know they were real." Elledge and his colleagues used VirScan to analyze the antibodies in 569 people from four countries, examining about 100 million potential antibody/epitope interactions. They found that on average, each person had antibodies to ten different species of viruses. As expected, antibodies against certain viruses were common among adults but not in children, suggesting that children had not yet been exposed to those viruses. Individuals residing South Africa, Peru, and Thailand, tended to have antibodies against more viruses than people in the United States. The researchers also found that people infected with HIV had antibodies against many more viruses than did people without HIV. Elledge says the team was surprised to find that antibody responses against specific viruses were surprisingly similar between individuals, with different people's antibodies recognizing identical amino acids in the viral peptides. "In this paper alone we identified more antibody/peptide interactions to viral proteins than had been identified in the previous history of all viral exploration," he says. The surprising reproducibility of those interactions allowed the team to refine their analysis and improve the sensitivity of VirScan, and Elledge says the method will continue to improve as his team analyzes more samples. Their findings on viral epitopes may also have important implications for vaccine design. Elledge says the approach his team has developed is not limited to antiviral antibodies. His own lab is also using it to look for antibodies that attack a body's own tissue in certain autoimmune diseases that are associated with cancer. A similar approach could also be used to screen for antibodies against other types of pathogens. Story Source: The above story is based on materials provided by Howard Hughes Medical Institute (HHMI). Note: Materials may be edited for content and length. Journal Reference: G. J. Xu, T. Kula, Q. Xu, M. Z. Li, S. D. Vernon, T. Ndung'u, K. Ruxrungtham, J. Sanchez, C. Brander, R. T. Chung, K. C. O'Connor, B. Walker, H. B. Larman, S. J. Elledge. Comprehensive serological profiling of human populations using a synthetic human virome. Science, 2015; 348 (6239): aaa0698 DOI: 10.1126/science.aaa0698

World's first digitally-encoded synthetic polymers

 

DNA rendering. Credit: © abhijith3747 / Fotolia Researchers have for the first time succeeded in recording a binary code on a synthetic polymer. Inspired by the capacity of DNA to retain an enormous amount of genetic information, a team from the Institut Charles Sadron de Strasbourg (CNRS) and the Institut de chimie radicalaire (CNRS/Aix Marseille Université) synthesized and read a multi-bit message on an artificial polymer. The results were published in Nature Communications on May 26, 2015. With its 3.4 billion base pairs, human DNA can compile a tremendous amount of information in a tiny space. All of the information stored is expressed using four nitrogenous bases: A, T, G and C. Researchers had previously been able to use the sequencing of these veritable molecular building blocks to reproduce a binary code. However, the technical limits of DNA made it necessary to develop the first synthetic polymer -- cheaper, more malleable and able to store binary information. This has now been achieved for the first time by a team of French scientists from the CNRS and Aix-Marseille Université. Instead of using the four nitrogenous bases of DNA, in this study the researchers used three monomers . Two of these monomers represent the binary code numbers 0 and 1, and can be used interchangeably during synthesis. A third nitroxide monomer was inserted between the bits in order to facilitate the writing and reading of the coded sequence. A short binary message is synthesized by hand, monomer by monomer on a growing chain. The operation takes approximately a day, but should be quicker once automated. Decoding is done by sequencing, in the same way that DNA has been decoded for decades. A mass spectrometer thus takes less than five minutes to decipher the information -- a duration also destined to be reduced in the short term. While sequencing systematically destroys the polymer, it is also possible to erase the code at any time and without reading it, by exposure to temperatures above 60ºC or to a laser. Researchers showed that at room temperature, the polymer can be conserved for a number of months, and could even last several years given the molecule's stability. The team hopes to store messages of a few kilobytes or even megabytes within 3 to 5 years. This technique, patented by the CNRS, also makes it possible to develop molecular barcodes in the short term. Sequences could provide labeling that would be extremely difficult to falsify, ideal for high value-added products such as luxury goods and medicine. The use of monomers and secret codes, known only to the laboratory and the industrial partner, would make it very difficult to produce counterfeits. Story Source: The above story is based on materials provided by CNRS. Note: Materials may be edited for content and length. Journal Reference: Raj Kumar Roy, Anna Meszynska, Chloé Laure, Laurence Charles, Claire Verchin, Jean-François Lutz. Design and synthesis of digitally encoded polymers that can be decoded and erased. Nature Communications, 2015; 6: 7237 DOI: 10.1038/ncomms8237

How feedback from cortex helps mammals make fine distinctions about odors

 

Precise discrimination of olfactory signals from the environment is nothing less than a survival skill, more so for mice, our mammalian cousins, than for us. Mice have relatively poor vision, and it is only thanks to their other senses, notably their incredible ability to identify and discriminate odors, that they can successfully hunt for food or choose a mate. Understanding how they do this, in turn, sheds light on the workings of our much more complex, but structurally related, brains. Led by CSHL Assistant Professor Florin Albeanu, the team explored a function in the mouse brain that scientists still don't know much about. After a mouse samples a smell by sniffing, and signals from that activity are gathered and subjected to preliminary processing in the animal's olfactory bulb, the bulb sends "output" signals to the brain's higher processing center, the cerebral cortex. Albeanu's team focused on "feedback" -- the signal that the olfactory cortex, in turn, sends back to the olfactory bulb. While there are theories aplenty about the nature and purpose of this feedback signal, very little is known about it. Even in the mouse brain, the feedback loop is a good deal more complex than just described. The olfactory bulb sends output to and receives feedback from multiple parts of the brain. Albeanu's team focused on one such feedback loop: signals sent from two principal cell types in the bulb, called mitral cells and tufted cells. These signals travel over long-distance axons to various parts of the brain, but most prominently to the piriform cortex. That's the brain's primary center for higher olfactory processing. Some theorists have speculated that the piriform cortex works as a pattern-recognition device that compares incoming sensory inputs with representations of previously experienced odors, stored up in memory. Not only is the piriform cortex thought to do this job; it is also involved in the integration of this information with contextual information (ranging from other data about the environment to whether the animal is hungry, amorous, afraid, etc.). Further, it is theorized that based on this data, the piriform cortex sends signals back to the olfactory bulb -- feedback -- that is essentially predictive, helping the animal to make decisions based on all available information. Albeanu's team, which included co-first authors Drs. Gonzalo Otazu and Hongggo Chae, as well as technician Martin Davis, made a series of discoveries in two related sets of experiments that support some of these theories. In one set, as they exposed awake mice to a panel of about 30 odorants, one by one, they traced the axons projecting back to the olfactory bulb from the piriform cortex -- the "wires," in effect, that carry the feedback signal -- and measured the responses of tiny button-like structures called synaptic boutons, the sites where these cortical feedback axons form connections, or synapses, in the bulb with local receiving neurons. These so-called interneurons are inhibitory. "The idea was to image the responses of the boutons in the olfactory bulb to a set of odorants," explains Albeanu. "It's very hard to physically access the piriform cortex for optical imaging, so we used these boutons as a proxy to indicate the nature of the signal that the cortex is feeding back to the bulb." The results were "striking," says Albeanu. First, it was clear that any given bouton responded only to a small fraction of the 30 odorants -- perhaps two or three, on average. This is what neuroscientists call a "sparse" response, and it indicates specificity. This immediately cast doubt on an existing theory suggesting that the feedback to the bulb is non-specific and acts like the volume, or "gain," control on an audio system. Rather, the response was specific and highly selective. Not only did a given bouton respond to very few odors; if it responded to one by amplifying the feedback signal (above the background level, since there is always activity in the circuit), it tended to perform that same function, amplification, on all of the odors it responded to. Conversely, those boutons that tamped down the signal coming back from the cortex tended to do that for all of the odors they responded to. A second set of experiments enabled Albeanu's team to offer a new hypothesis of the purpose of this particular cortical feedback. By injecting mice with a drug that inactivates the piriform cortex, they were able to examine the activity of the output cells in the olfactory bulb that normally integrate the cortical feedback via inhibitory interneurons. Again a striking result: as compared with their activity profiles when receiving feedback, mitral cells in the olfactory bulb tended to have overlapping responses when the feedback was cut off. In other words, their activity profiles started to look quite similar. This suggests that without feedback from the cortex, mitral cells are no longer to supply the animal with information that can sharply distinguish odors, particularly odors that are chemically similar. Taken together, the results lead Albeanu to propose that feedback from the cortex is highly specific, and likely used to create a useful representation of the animal's environment, "in a very specific and selective fashion that, in turn, is used to extract the identity of a given odor and to separate it from other odors," Albeanu says. The research continues now in experiments featuring animals that are actively engaged in odor discrimination in their environment, in order to obtain behavioral evidence to correlate with the results of the experiments published today.

Why are 95% of people who live to 110 women? You're as old as your stem cells

 

"As the search continues for ways to ameliorate the aging process and maintain the regenerative capacity of stem cells, let us not forget one of the most effective aging modifiers: sex," authors write. Human supercentenarians share at least one thing in common--over 95 percent are women. Scientists have long observed differences between the sexes when it comes to aging, but there is no clear explanation for why females live longer. In a discussion of what we know about stem cell behavior and sex, Stanford University researchers Ben Dulken and Anne Brunet argue that it's time to look at differences in regenerative decline between men and women. This line of research could open up new explanations for how the sex hormones estrogen and testosterone, or other factors, modify lifespan. It's known that estrogen has direct effects on stem cell populations in female mice, from increasing the number of blood stem cells (which is very helpful during pregnancy) to enhancing the regenerative capacity of brain stem cells at the height of estrus. Whether these changes have a direct impact on lifespan is what's yet to be explored. Recent studies have already found that estrogen supplements increase the lifespan of male mice, and that human eunuchs live about 14 years longer than non-castrated males. More work is also needed to understand how genetics impacts stem cell aging between the sexes. Scientists have seen that knocking out different genes in mice can add longevity benefits to one sex but not the other, and that males in twin studies have shorter telomeres--a sign of shorter cellular lifespan--compared to females. "It is likely that sex plays a role in defining both lifespan and healthspan, and the effects of sex may not be identical for these two variables," the authors write. "As the search continues for ways to ameliorate the aging process and maintain the regenerative capacity of stem cells, let us not forget one of the most effective aging modifiers: sex." Story Source: The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length. Journal Reference: Ben Dulken, Anne Brunet. Stem Cell Aging and Sex: Are We Missing Something? Cell Stem Cell, 2015; 16 (6): 588 DOI: 10.1016/j.stem.2015.05.006

Intravenous nutrition source could reduce side effects of chemotherapy

 

Jun 03, 2015 A single dose of an FDA-approved intravenous nutrition source may be able to significantly reduce the toxicity and increase the bioavailability of platinum-based cancer drugs, according to a study by Carnegie Mellon University biologists published in Scientific Reports. Platinum-based drugs, including cisplatin, carboplatin and oxyplatin, have been used to treat cancer for more than 35 years. While they remain among the most prescribed and most potent chemotherapy drugs, they also cause serious side effects, including kidney damage. Many of the side effects of these drugs occur when the drug settles in healthy tissue. To deliver these drugs in a more targeted way, researchers have created nanoscale delivery systems engineered to make the drug reach and accumulate at the tumor site. However, tests of these nanodrugs show that only between one and 10 percent of the drugs are delivered to the tumor site, with the majority of the remainder being diverted to the liver and spleen. 'The body's immune system, especially the liver and spleen, has been one of the biggest stumbling blocks in developing nanoscale chemotherapy drug delivery systems,' said Chien Ho, the alumni rofessor of biological sciences at Carnegie Mellon. 'When the drugs collect in those organs, they become less available to treat the cancer, and can also cause toxicity.' In the past few years, Ho and his colleagues were developing cellular nanotags to help detect organ rejection, when Ho noticed that Intralipid, a fat emulsion that is FDA-approved for use as an intravenous nutrition source, reduced the amount of nanoparticles that were being cleared by the liver and spleen by about 50 percent. As a result, the nanoparticles remained in the blood stream for longer periods of time. Ho and his colleagues decided to see if Intralipid had the same effect on platinum-based anti-cancer nanodrugs. In the newly published study, the researchers administered a single, clinical dose of Intralipid to a rat model. One hour later, they administered a dose of a platinum-based chemotherapy drug that had been incorporated into a nanoparticle. Twenty-four hours after the drug was administered, the researchers found that pre-treatment with Intralipid reduced the accumulation of the platinum-based drug by 20.4 percent in the liver, 42.5 percent in the spleen and 31.2 percent in the kidney. Consequently, in these organs, the toxic side effects of the nanodrug decreased significantly. Furthermore, the researchers found that Intralipid pre-treatment allowed more of the drug to remain available and active in the body for longer periods of time. After five hours, availability of the drug was increased by 18.7 percent, and after 24 hours it was increased by 9.4 percent. The researchers believe that this increased availability will allow more of the drug to reach the tumor site, and could perhaps also allow clinicians to reduce the dosage needed to treat a patient. The researchers are currently investigating the possibility of bringing this research to a clinical trial. Explore further: Study identifies possible new combination chemotherapy for patients with advanced prostate cancer

Friboi, campeã nacional em acidentes de trabalho

 

JBS lidera registros de acidentes de trabalho em frigoríficos, segundo Ministério da Previdência Nos comerciais da Friboi na TV, o roteiro se repete. O ator Tony Ramos faz uma visita-surpresa à casa de um consumidor, para perguntar qual carne costuma comprar, e encontra um produto da marca na geladeira. “Carne confiável tem nome”, diz o artista. Quando fiscais aparecem repentinamente nas unidades da JBS, dona da Friboi, o resultado tende a ser previsível como a propaganda. Irregularidades e violações de direitos trabalhistas são tão frequentes que deixaram 7.822 funcionários da empresa doentes ou incapacitados para o trabalho nos últimos quatro anos. Isso equivale a cinco acidentes por dia durante todo o período. Dados inéditos obtidos pela Pública com o Ministério da Previdência Social, por meio da Lei de Acesso à Informação, mostram que a JBS foi a campeã em comunicados de acidentes de trabalho, de 2011 a 2014, somando-se os setores de abate de gado e de fabricação de produtos de carne. No setor de abate de aves – em que começou a se expandir nos últimos dois anos, com a compra da Seara e de outros frigoríficos –, a empresa já subiu para o segundo lugar em 2014 e ficou quase empatada com a BRF (antiga Brasil Foods). Linha de produção da unidade de Rolândia (PR), interditada após fiscalização. / MPT/PR Com lucro líquido de 2,04 bilhões de dólares em 2014, a JBS é hoje o maior grupo privado do país em faturamento e a maior processadora de carnes do mundo. No ano passado, as vendas somaram 120 bilhões de reais. Esse gigantismo foi conseguido com a ajuda de dinheiro público. O Banco Nacional de Desenvolvimento Econômico e Social (BNDES), por meio da BNDES Participações (BNDESPar), fez aportes de 8,1 bilhões de reais para favorecer aquisições, tornando-se seu maior sócio. A BNDESPar chegou a deter um terço do grupo. Em 2012, repassou uma cota equivalente a 10% de participação para a Caixa Econômica Federal e manteve-se com 24,5%. O grupo foi, também, o maior doador na campanha eleitoral do ano passado e destinou 366,8 milhões de reais a candidatos e partidos políticos. A maioria dos acidentes da JBS no país ocorreu no setor de abate de bovinos, uma área historicamente perigosa para os trabalhadores. Foram registrados 4.867 comunicados no total: 1.294 em 2011, 1.225 em 2012, 1.261 em 2013 e 1.087 em 2014. Nesse setor, a empresa foi responsável por um em cada quatro acidentes informados ao Instituto Nacional do Seguro Social (INSS) entre 2011 e 2013 – cerca de 25% ao ano. Houve redução de 14% nos comunicados da JBS de 2013 para 2014, mas a empresa ainda concentrou um em cada cinco acidentes reportados no último ano (21%) e ficou atrás apenas da Marfrig. Na área de fabricação de produtos de carne, foram 506 acidentes reportados em 2011, 262 em 2012, 327 em 2013 e 369 em 2014 (incluindo a Seara, comprada em 2013). Nos quatro anos, a JBS foi a empresa com maior quantidade de casos. Já no setor de abate de aves, os incidentes começaram a aparecer em 2012, com a criação da divisão JBS Aves a partir do arrendamento da Doux Frangosul. Foram 49 comunicados naquele ano. Em 2013, a quantidade subiu para 289. Em 2014, depois da aquisição da Seara, houve um salto para 1.153 casos. Ao todo, 3.110 acidentes da JBS de 2011 a 2014 (39%) ocorreram na Amazônia Legal, principalmente no Mato Grosso. O estado tem o maior rebanho bovino do país, com 28,3 milhões de cabeças, segundo a pesquisa Produção da Pecuária Municipal de 2013, do Instituto Brasileiro de Geografia e Estatística (IBGE). O grupo mantém unidades também no Acre, no Maranhão, no Pará e em Rondônia. Foram registrados 713 incidentes na Amazônia Legal em 2011. O número passou para 821 em 2012, 840 em 2013 e 736 em 2014. Apesar das flutuações, foram dois por dia, em média, a cada ano. Infrações deliberadas Os dados fornecidos pelo Ministério da Previdência Social confirmam a percepção dos procuradores do Ministério Público do Trabalho que fiscalizam de perto esses setores. “A JBS tem uma política deliberada de precarização dos direitos fundamentais dos trabalhadores”, afirma o procurador Sandro Eduardo Sardá, gerente nacional do Programa de Adequação das Condições de Trabalho nos Frigoríficos. “Isso vem gerando uma legião de trabalhadores amputados e mortos em razão de acidentes de trabalho.” O grupo foi criado em 2010 por causa do elevado número de problemas registrados nesse tipo de empresa. De acordo com Sardá, a JBS mantém condições ruins de trabalho para obter o máximo de lucro. Isso é feito de várias maneiras. Em uma das mais comuns, adota-se um ritmo excessivo – e, portanto, ilegal – na jornada dos funcionários. “É um ritmo de trabalho incompatível com a proteção à saúde dos trabalhadores”, diz o procurador. Nos frigoríficos de aves, isso leva muitos dos funcionários a adquirir doenças ocupacionais. Nos frigoríficos de bovinos, tem como resultado uma grande quantidade de amputações. Uma amostra da extensão do problema pôde ser vista recentemente. No dia 13 de maio, uma força-tarefa formada pelo Ministério Público do Trabalho, pelo Ministério do Trabalho e Emprego, pelo INSS, pela Receita Federal e pela Advocacia-Geral da União interditou 45 máquinas que apresentavam riscos à saúde dos trabalhadores em uma unidade de abate de frangos da empresa em Rolândia, no Paraná. Com 4.000 funcionários, a fábrica pertence à Big Frango, adquirida pela JBS no ano passado, e abate 400.000 frangos por dia. Entrevistas feitas com 400 trabalhadores durante a operação mostram as consequências de uma jornada excessiva. Uma parcela de 52,9% dos funcionários ouvidos – ou seja, mais da metade – admitiu ter tomado algum tipo de remédio, aplicado emplastros ou feito compressas para poder trabalhar nos 12 meses anteriores. Além disso, 38% deles disseram sentir uma dor forte durante a realização de suas atividades. Terminado o dia de trabalho, 75,4% afirmaram ficar cansados (35,1%), muito cansados (23%) ou exaustos (17,3%). A força-tarefa escolheu essa unidade, entre tantas outras, por meio de cruzamentos de dados públicos e privados. Os procuradores identificaram uma enorme quantidade de consultas médicas relacionadas ao trabalho no ano passado. Foram 2.033, além de 70.279 atendimentos de enfermagem, equivalentes a 225 por dia nessa fábrica. Já os afastamentos por doenças osteomusculares ou traumas somaram 6 mil horas em 2014. Tipos de acidentes de trabalho na JBS (2011-2014) Muitos dos problemas vêm da gestão anterior, mas os resultados da operação indicam que não houve mudanças significativas. “Algumas empresas já tinham condições ruins de trabalho, em razão de má administração. Eles vieram, adquiriram essas indústrias e a situação dos trabalhadores piorou, envolvendo a questão salarial e a questão de saúde”, diz Ernane Garcia Ferreira, presidente da Federação dos Trabalhadores nas Indústrias da Alimentação do Estado do Paraná (FTIAPR). “Lucro, lucro, lucro. Essa é a visão da empresa.” Mais rápidos que máquinas Uma fiscalização na unidade de Montenegro (RS), no início do ano passado, resultou na interdição de máquinas e atividades. Foram aplicados 33 autos de infração após a visita. Entre as irregularidades, uma das que mais chamaram a atenção dos fiscais foi a situação dos funcionários responsáveis por embalar frangos do tipo griller – um galeto pequeno, exportado principalmente para o Oriente Médio. Para colocar a ave dentro de um saco plástico, é necessário passá-la dentro de um funil. Os funcionários escalados para a tarefa realizavam nada menos de 90 movimentos por minuto com os braços. Com isso, os trabalhadores conseguiam embalar 30 frangos por minuto, ou um frango a cada dois segundos, aproximadamente, com três movimentos. Não existem máquinas capazes de atingir tamanha produtividade. As mais rápidas embalavam 15 frangos por minuto, metade da velocidade de um funcionário da JBS. “Se uma máquina consegue dar conta apenas dessa produção, imagine o nível de exigência dos músculos, dos tendões, dos braços do trabalhador nesse posto”, afirma Mauro Müller, auditor fiscal do Ministério do Trabalho e Emprego no Rio Grande do Sul. Ao todo, 93% dos empregados entrevistados no setor disseram ter sentido dor na semana anterior à visita. A mesma operação verificou as condições na unidade de Passo Fundo (RS) e encontrou funcionários lidando com uma quantidade de peso acima do normal. No setor de descarregamento de frango vivo, havia pessoas manuseando 50 toneladas por dia. O máximo permitido pela legislação, no entanto, são 10 toneladas diárias. A fábrica também usa empilhadeiras e paleteiras elétricas movidas a bateria, que pesam 1,1 tonelada cada. A troca dessas baterias, feita a cada turno, era manual. Os funcionários usavam o corpo para fazer a substituição, empurrando ou puxando as peças. A fiscalização dos relógios de ponto na unidade de Passo Fundo, de 16 de maio a 15 de dezembro do ano passado, identificou cerca de 27.000 jornadas além do limite permitido. “É muita coisa. É praticamente o setor produtivo todo trabalhando uma média diária de 9h40”, diz Müller. “A partir do momento em que você prorroga a jornada além das oito horas, estaria aumentando em 50% o risco de adoecimento por LER/Dort [lesões por esforços repetitivos/distúrbios osteomusculares relacionados ao trabalho]. É muito grave. Há o aumento da jornada, o aumento da fadiga e o aumento do risco de adoecimento num ambiente que tem vários outros fatores de risco.” No Mato Grosso, estado que concentra a maior quantidade de acidentes da JBS, uma das linhas de atuação do Ministério Público do Trabalho tem sido impedir as horas extras em ambientes insalubres. “A atividade do frigorífico tem ritmo intenso, com um grande número de movimentos na unidade do tempo, atuando em baixas temperaturas. Então, há uma porção de riscos”, explica Leomar Daroncho, procurador do Ministério Público do Trabalho do Mato Grosso. “Tem uma série de condenações com fundamento da insalubridade. Nessas condições, não é razoável que os trabalhadores fiquem expostos além do número de horas que a legislação permite.” Desobedecer à jornada de trabalho máxima permitida, no entanto, não é exclusividade da JBS. Isso vale para outras transgressões à legislação cometidas em frigoríficos. “Os problemas que o setor tem, a JBS também tem. Sob o ponto de vista trabalhista, não é muito diferente do que ocorre com as demais empresas. Como é a maior, é claro que tem mais problemas”, diz Daroncho. “No Mato Grosso, o setor de frigoríficos é o que mais tem mais acidentes de trabalho e está bem à frente do segundo lugar.” Ele estima que de 30% a 35% das ações na Justiça do Trabalho no estado envolvam essas empresas. Salários baixos são comuns, principalmente porque muitos frigoríficos estão instalados em cidades pequenas, com poucas opções de inserção no mercado de trabalho. Isso estimula a prestação de horas extras. “O trabalhador acaba buscando na jornada excedente uma forma de sobreviver, de custear a sua vida. E com isso ele produz a médio prazo sérios problemas em relação à integridade física dele mesmo”, ressalta Daroncho. Também falta muitas vezes uma estrutura física adequada para o trabalho. Funcionários da JBS da área fria na unidade de Pontes e Lacerda (MT), por exemplo, não tinham um lugar adequado para descansar. Depois de trabalharem a quase zero grau, ficavam em ambiente externo, cuja temperatura às vezes beirava 40 graus. Uma decisão judicial de novembro do ano passado obrigou a empresa a construir um espaço refrigerado para as pausas. Determinações como essa trazem multas pesadas se forem descumpridas. Realidade oculta Os dados de acidentes de trabalho da JBS e de outras empresas podem esconder um cenário muito pior. Isso porque o setor de frigoríficos é conhecido por não comunicar muitas das ocorrências. Com medo de perder o emprego ou as bonificações que melhoram os baixos salários, funcionários costumam trabalhar adoentados. “Há os casos que vão para a mídia e também aqueles que não aparecem. O trabalhador corta o dedo, recebe quatro, cinco pontos e vai trabalhar, porque é o encarregado daquele dia. Se faltar, perde prêmio de abate, de couro, de desossa. Então prefere trabalhar acidentado a ficar afastado”, diz Vilson Gimenes Gregório, presidente do Sindicato dos Trabalhadores nas Indústrias de Carne e Derivados de Campo Grande, no Mato Grosso do Sul. Acidentes de trabalho na JBS por tipo de atividade econômica (2011-2014) O assédio moral na linha de produção, segundo Gregório, também é comum. “O trabalhador está ali, fazendo o serviço. Os supervisores querem que faça mais rápido e gritam. As mulheres querem ir ao banheiro e não podem ir antes do intervalo. Se forem, são preguiçosas, não querem trabalhar. Esse é o tratamento deles”, afirma o sindicalista. Benefícios acertados em convenção coletiva, como cesta básica, às vezes são cortados pela empresa se o funcionário faltar, o que é ilegal. “Eles não respeitam os acordos coletivos. Passam por cima de tudo e fazem do jeito deles”, diz Gregório. Até mesmo atestados de saúde que determinam afastamentos têm o tempo reduzido sem a devida justificativa. O índice de subnotificação de acidentes de trabalho no setor pode passar de 90% a 95%, calcula o procurador Heiler Ivens de Souza Natali, coordenador nacional do Programa de Adequação das Condições de Trabalho nos Frigoríficos. De acordo com Natali, o problema acaba sendo evidenciado com a atuação das forças-tarefa que fazem inspeções nas unidades. Quando os fiscais descobrem afastamentos que podem ter ocorrido devido à natureza da atividade e não foram comunicados, isso pode resultar em uma ação judicial, por exemplo. Por isso, os dados de comunicados de acidentes de trabalho segundo a Classificação Nacional de Atividades Econômicas (CNAE), divulgados pelo Ministério da Previdência Social, são apenas uma amostra do que ocorre de fato. Diante do enorme número de problemas, Natali afirma que a JBS tem feito algumas mudanças para diminuir a quantidade de acidentes de trabalho nos seus frigoríficos. “A JBS tem uma política de segurança que está tentando implementar. Isso é verdade”, afirma. “Só que há uma outra discussão: se essa política está adequada e se ela está em vigor nas unidades do Brasil inteiro. E, para os dois questionamentos, a resposta, em princípio, não é afirmativa.” A realidade não corresponde às imagens mostradas na publicidade. Máquina de limpar moela que continuava em operação sem as proteções necessárias em unidade da JBS Friboi. / MTE / Repórter Brasil A situação torna-se ainda mais complicada por causa do modo como o grupo se expande no país. Em vez de comprar empresas saudáveis e lucrativas, a JBS prefere adquirir frigoríficos altamente endividados. “Considerada a política de aquisições da JBS, que não parece levar em consideração as condições de trabalho oferecidas pela empresa que está sendo adquirida, imaginamos que o reflexo disso seja a existência de um número de unidades com elevado nível de violações de direitos trabalhistas”, afirma Natali. Segundo o procurador, isso resultará, mais tarde, em um cenário litigioso. A Pública procurou a JBS para saber por que o número de acidentes de trabalho nas unidades da empresa é tão elevado. Perguntamos também que tipos de medidas vêm sendo tomadas para diminuir esse tipo de ocorrência e quanto do faturamento tem sido investido em programas de prevenção e redução de acidentes nos últimos anos. Questionamos ainda por que interdições de máquinas e condenações judiciais são tão frequentes nas unidades do grupo. A JBS não se manifestou até a publicação desta reportagem. Um vídeo incômodo Um dos atritos mais recentes entre os sindicatos e a JBS é a questão do plano de saúde. Nas unidades de Forquilhinha (SC) e Nova Veneza (PR), a empresa reajustou o valor do plano individual e tentou cobrar uma taxa adicional de 104 reais para cada dependente. Isso aumentaria o impacto no contracheque dos funcionários. Como os salários giram em torno de 1.000 reais, abatimentos extras poderiam inviabilizar a adoção do benefício. Em outros locais, como os frigoríficos de abate de bovinos, os trabalhadores não têm plano e a empresa não queria concedê-lo. Como o grupo se recusava a negociar, a Confederação Nacional dos Trabalhadores na Alimentação (Contac/CUT) produziu um vídeo em que denunciava o problema e publicou o conteúdo no YouTube, em fevereiro deste ano. O filme, de pouco mais de um minuto, foi inspirado nas propagandas da JBS e recebeu legendas em inglês. Uma consumidora chega ao açougue e pede a carne "daquele ator famoso". O atendente, então, fala sobre o reajuste do plano de saúde. Assustada, a cliente decide adquirir outro produto. A Contac também convocou uma manifestação na Avenida Paulista, em São Paulo, para denunciar as más condições de trabalho nos frigoríficos do grupo. Foi o que bastou para a JBS criar uma mesa de negociações com os sindicalistas. A primeira reunião ocorreu em 12 de março, dia do protesto, que acabou desmarcado. "A empresa passou a dialogar com a gente", afirma Wagner do Nascimento Rodrigues, secretário-geral da FTIAPR. "Infelizmente o diálogo ainda não gerou como fruto a solução de problemas." Os encontros com os sindicalistas têm ocorrido uma vez por mês, em média, desde março. Outras questões trabalhistas também são debatidas com Wesley Batista, presidente executivo da JBS, como a adoção de um piso salarial unificado para os funcionários em todo o país. "Iniciamos uma pauta nacional", diz Siderlei de Oliveira, presidente da Contac. "Já começamos a discutir o plano de saúde. Vamos ver se avançamos mais aí. Pelo menos mudou esse aspecto de relação sindical, que nós não tínhamos há anos."

Good eyes but poor vision: An indistinct world for one in 20

 

Extremely poor vision can be caused by strabismus in early childhood or by a displaced optical axis. Amblyopia is caused not by organic damage to the eyes but by the brain incorrectly fitting together the images the eyes provide. As a result, the ability to see an object in sharp focus is severely limited. This occurs in more than one in 20 of the German population, as Heike M. Elflein et al. show in a recent original article in Deutsches Ärzteblatt International. The authors' study analyzed the visual acuity of over 3200 individuals aged between 35 and 44 years and determined the frequency and causes of amblyopia. Study participants were examined by ophthalmologists; over 180 participants presented evidence of amblyopia. In half of those affected, lack of visual acuity was caused by differences in refraction between the two eyes (anisometropia); in almost one in four it was caused by strabismus. Because the eyes are actually intact, standard eye examinations do not detect this disease. In everyday life too, the symptoms are almost never detected in children. This has profound consequences, as vision problems caused by amblyopia have to be treated early: the older the child, the lower the chance of successful treatment. The authors therefore indicate that primary care physicians and pediatricians, as well as ophthalmologists, must be vigilant for amblyopia. Story Source: The above story is based on materials provided by Deutsches Aerzteblatt International. Note: Materials may be edited for content and length. Journal Reference: Elflein HM, Fresenius S, Lamparter J, Pitz S, Pfeiffer N, Binder H, Wild P, Mirshahi A. The prevalence of amblyopia in Germany—data from the prospective, population-based Gutenberg Health Study. Dtsch Arztebl Int, June 2015 DOI: 10.3238/arztebl.2015.0338

Why good people do bad things

 

Honest behavior is much like sticking to a diet. When facing an ethical dilemma, being aware of the temptation before it happens and thinking about the long-term consequences of misbehaving could help more people do the right thing, according to a new study. The study, "Anticipating and Resisting the Temptation to Behave Unethically," by University of Chicago Booth School of Business Behavioral Science and Marketing Professor Ayelet Fishbach and Rutgers Business School Assistant Professor Oliver J. Sheldon, was recently published in the Personality and Social Psychology Bulletin. It is the first study to test how the two separate factors of identifying an ethical conflict and preemptively exercising self-control interact in shaping ethical decision-making. In a series of experiments that included common ethical dilemmas, such as calling in sick to work and negotiating a home sale, the researchers found that two factors together promoted ethical behavior: Participants who identified a potential ethical dilemma as connected to other similar incidents and who also anticipated the temptation to act unethically were more likely to behave honestly than participants who did not. "Unethical behavior is rampant across various domains ranging from business and politics to education and sports," said Fishbach. "Organizations seeking to improve ethical behavior can do so by helping people recognize the cumulative impact of unethical acts and by providing warning cues for upcoming temptation." In one experiment, business school students were divided into pairs as brokers for the buyer and seller of a historic New York brownstone. The dilemma: The seller wanted to preserve the property while the buyer wanted to demolish it and build a hotel. The brokers for the seller were told to only sell to a buyer who would save the brownstone, while the brokers for the buyer were told to conceal the buyer's plan to develop a hotel. Before the negotiations began, half of the students were asked to recall a time when they cheated or bent the rules to get ahead. Only 45 percent of those students thinking about their ethics ahead of time behaved unethically in the negotiations, while more than two-thirds, or 67 percent, of the students who weren't reminded of an ethical temptation in advance, lied in the negotiations in order to close the deal. In another experiment involving workplace scenarios, participants were less likely to say it is okay to steal office supplies, call into work sick when they aren't really ill, or intentionally work slowly to avoid additional tasks, if they anticipated an ethical dilemma through a writing exercise in advance and if they considered a series of six ethical dilemmas all at once. In other words, people are more likely to engage in unethical behavior if they believe the act is an isolated incident and if they don't think about it ahead of time. The results of the experiments have the potential to help policy makers, educators and employers devise strategies to encourage people to behave ethically. For example, a manager could control costs by emailing employees before a work trip to warn them against the temptation to inflate expenses. The notice could be even more effective if the manager reminded employees that the urge to exaggerate expenses is a temptation they will encounter repeatedly in the future. Story Source: The above story is based on materials provided by University of Chicago Booth School of Business. Note: Materials may be edited for content and length. Journal Reference: O. J. Sheldon, A. Fishbach. Anticipating and Resisting the Temptation to Behave Unethically. Personality and Social Psychology Bulletin, 2015; DOI: 10.1177/0146167215586196

Autologous stem cell therapy helpful in traumatic brain injury

 

The use of cell therapy after traumatic brain injury (TBI) in children can reduce the amount of therapeutic interventions needed to treat the patient, as well as the amount of time the child spends in neurointensive care, according to research by The University of Texas Health Science Center at Houston (UTHealth) Medical School. The study appeared in the most recent issue of Pediatric Critical Care Medicine. TBI patients at Children's Memorial Hermann Hospital from 2000 to 2008 were divided into two groups: those who received autologous bone marrow stem cells as part of a pilot study and those who did not. Researchers used the Pediatric Intensity Level of Therapy score to determine the degree of therapeutic intensity that was done to reduce the cranial pressure below the danger zone. For those who received the stem cells, researchers noted a significant reduction in the score beginning at 24 hours post-treatment through the first week. Patients who did not receive the stem cells spent nearly twice as much time in neurointensive care -- 15.6 days compared to 8.2. "Everything we do to treat traumatic brain injury is aimed at reducing the pressure in the brain," said Charles S. Cox, Jr., M.D., principal investigator, professor and the George and Cynthia Mitchell Distinguished Chair in Neurosciences at UTHealth and co-director of the Texas Trauma Institute at Memorial Hermann-Texas Medical Center. "We can measure the pressure and there are medications to reduce the water in the brain but all of those have risks associated with them, such as renal failure and kidney problems. Our study showed that with stem cell therapy, we need to do less intervention for a shorter period of time for the patient." Story Source: The above story is based on materials provided by University of Texas Health Science Center at Houston. The original article was written by Deborah Mann Lake. Note: Materials may be edited for content and length. Journal Reference: George P. Liao, Matthew T. Harting, Robert A. Hetz, Peter A. Walker, Shinil K. Shah, Christopher J. Corkins, Travis G. Hughes, Fernando Jimenez, Steven C. Kosmach, Mary-Clare Day, KuoJen Tsao, Dean A. Lee, Laura L. Worth, James E. Baumgartner, Charles S. Cox. Autologous Bone Marrow Mononuclear Cells Reduce Therapeutic Intensity for Severe Traumatic Brain Injury in Children*. Pediatric Critical Care Medicine, 2015; 16 (3): 245 DOI: 10.1097/PCC.0000000000000324

Arabidopsis uses molecular decoy to trick pathogens

 

Arabidopsis plants inoculated via the roots with a strain of Ralstonia solanacearum producing effector PopP2.Right, a plant lacking the decoy receptor is unable to recognize the presence of the bacterium that thus succeeds in killing its host.Left, a plant with the decoy receptor is able to detect the presence of the PopP2 effector injected by the bacteria and thus to establish an immune response that blocks the invasion.© Laurent Deslandes - Laboratoire des interactions plantes micro-organismes. Credit: CNRS / INRA In the animal kingdom, predators use a full range of strategies, such as camouflage, speed and optical illusions, to catch their prey. Meanwhile, prey species resort to the same tactics to escape from their predators. Such tricks are also used at the molecular level, as discovered by researchers from the CNRS, INRA, CEA and INSERM[1] in one of the most devastating bacterial plant pathogens in the world, which bypasses plant cell defenses by preventing an immune signaling from being triggered. Even more surprising is the fact that plant cells have developed a receptor incorporating a decoy intended to catch the invader in its own trap. This work, which has a wealth of applications, was published May 21, 2015 in the journal Cell. As in humans, interception of pathogens by the immune system is essential for plants, allowing them to ensure their survival, growth and productivity. Their defense responses rely entirely on genetic resistance (innate immunity) conferred by a family of receptors expressed in individual cells. These receptors are inactive until they are activated following recognition of specific pathogenic molecules, called effectors, whose objective is often to block immune pathways. The speed at which microbial pathogens can produce new effectors that promote infection puts considerable pressure on plants, forcing them to constantly acquire new detection capabilities. In this article, published in the journal Cell, the researchers describe a particularly ingenious defense mechanism in the model plant Arabidopsis. This mechanism enables the plant to convert the virulence activity of a bacterial effector into a trigger for a rapid immune response. Ralstonia solanacearum, a bacterium responsible for bacterial wilt of many plant species, including tomato and tobacco, has developed a particularly effective invasion strategy. Among the many effectors that the bacterium injects into host cells to block the immune defenses is the protein PopP2, whose mode of action was brought to light in the present study. PopP2 was examined within the cell nucleus, where DNA regions are capped with proteins (transcription factors) responsible for regulating the expression of defense-related genes. Once inside the nucleus, PopP2 uses its enzymatic activity to inhibit the binding of some transcription factors in relation to their target sequences. Thus dislodged and neutralized, these proteins are unable to activate the defenses, allowing the invader to "clean-up." From this discovery in Arabidopsis thaliana, which is one of the "preys" of the bacterium Ralstonia solanacearum, the researchers identified a defense mechanism just as radical as that deployed by the bacterium. Among the proteins that PopP2 interferes with, one was found to be a decoy directly integrated into an immune receptor. By attacking this decoy, PopP2 accidentally triggers the plant's alarm signal as this receptor, once separated from the DNA, becomes able to orchestrate the defense response. The integration of a "decoy" into the studied receptor has a distinct advantage: such a "monitoring system" is difficult for the pathogen to overcome since it is the intrinsic activity of the effector that activates the immune response. Bypassing the usual process of evolution, in which each party improves its arsenal in turn, gives the plant cell the upper hand. As a result, even if PopP2 evolves but as long as its activity remains unchanged, it will inevitably activate the cell's defense mechanisms. This molecular strategy of "integrated decoys" may be more widespread than it seems, which raises the question of whether the areas of unknown function in the immune receptors of many plant species could be related to decoys. This discovery is more than a step forward in the understanding of an original mechanism as it paves the way for the development of new immune receptors that could very efficiently intercept the virulence factors of the pathogens responsible for significant agricultural losses every year. Story Source: The above story is based on materials provided by CNRS (Délégation Paris Michel-Ange). Note: Materials may be edited for content and length. Journal Reference: Clémentine Le Roux, Gaëlle Huet, Alain Jauneau, Laurent Camborde, Dominique Trémousaygue, Alexandra Kraut, Binbin Zhou, Marie Levaillant, Hiroaki Adachi, Hirofumi Yoshioka, Sylvain Raffaele, Richard Berthomé, Yohann Couté, Jane E. Parker, Laurent Deslandes. A Receptor Pair with an Integrated Decoy Converts Pathogen Disabling of Transcription Factors to Immunity. Cell, 2015; 161 (5): 1074 DOI: 10.1016/j.cell.2015.04.025

Top salads with eggs to better absorb vegetables' carotenoids

 

Research led by Wayne Campbell, a Purdue University professor of nutrition science, found that adding eggs to a salad mixed with a variety of raw vegetables is an effective method to improve nutrient absorption. The research is published in the American Journal of Clinical Nutrition. Credit: Purdue University photo/John Underwood Adding eggs to a salad with a variety of raw vegetables is an effective method to improve the absorption of carotenoids, which are fat-soluble nutrients that help reduce inflammation and oxidative stress, according to research from Purdue University. "Eating a salad with a variety of colorful vegetables provides several unique types of carotenoids, including beta-carotene, lutein, zeaxanthin and lycopene," said Wayne Campbell, a professor of nutrition science. "The lipid contained in whole eggs enhances the absorption of all these carotenoids." This research is published online in the American Journal of Clinical Nutrition and is funded by the American Egg Board-Egg Nutrition Center, National Institutes of Health and Purdue Ingestive Behavior Research Center. "Most people do not eat enough vegetables in their diets, and at the same time, people are consuming salad dressings that have less fat or are fat-free," said Jung Eun Kim, a postdoctoral researcher in Purdue's Department of Nutrition Science. "Our research findings support that people obtained more of the health-promoting carotenoids from raw vegetables when cooked whole eggs were also consumed. Eggs, a nutrient-rich food containing essential amino acids, unsaturated fatty acids and B vitamins, may be used to increase the nutritive value of vegetables, which are under consumed by the majority of people living in the United States." In the study, 16 participants consumed a raw mixed-vegetable salad with no eggs, a salad with one and a half eggs, and a salad with three eggs at different times. All salads were served with three grams of canola oil. The second salad had 75 grams of scrambled whole eggs and the third 150 grams of scrambled whole eggs. The absorption of carotenoids was 3.8-fold higher when the salad included three eggs compared to no eggs. The study used scrambled eggs to make sure the participants consumed both the yolk and egg whites. "While other egg forms were not tested, we believe the results would be comparable as long as the egg yolk is consumed," said Campbell, whose research also has looked at salads with different amounts of soybean oil, canola oil and butter. "The lipids in salad dressings also increase the absorption of carotenoids but it is easy to overuse salad dressings and consume excess calories. Many salad dressings contain about 140-160 calories per serving, about two tablespoons. One large whole egg is about 70 calories and provides 6 grams of protein. People are at a greater risk of putting too many calories on a salad because they don't always know proper portion sizes for salad dressings, but you do know the portion size of an egg." Story Source: The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length. Journal Reference: J. E. Kim, S. L. Gordon, M. G. Ferruzzi, W. W. Campbell. Effects of egg consumption on carotenoid absorption from co-consumed, raw vegetables. American Journal of Clinical Nutrition, 2015; DOI: 10.3945/ajcn.115.111062

How 'perfect' materials begin to fail

 

The distribution of strengths observed at different temperatures. Credit: Image courtesy of University of Pennsylvania Crystalline materials have atoms that are neatly lined up in a repeating pattern. When they break, that failure tends to start at a defect, or a place where the pattern is disrupted. But how do defect-free materials break? Until recently, the question was purely theoretical; making a defect-free material was impossible. Now that nanotechnological advances have made such materials a reality, however, researchers at the University of Pennsylvania and Germany's Max Planck Institute for Intelligent Systems have shown how these defects first form on the road to failure. In a new study, published in Nature Materials, they stretched defect-free palladium nanowires, each a thousand times thinner than a human hair, under tightly controlled conditions. Contrary to conventional wisdom, they found that the stretching force at which these wires failed was unpredictable, occurring in a range of values that were more strongly influenced by the ambient temperature than was previously believed. This thermal uncertainty in the failure limit suggests that the point where a failure-inducing defect first appears is on the nanowire's surface, where atoms behave in a more liquid-like way. Their increased mobility makes it more likely they will rearrange themselves into the beginnings of a "line defect," which cuts across the nanowire, causing it to break. The study was led by graduate student Lisa Chen and associate professor Daniel Gianola of the Department of Materials Science and Engineering in Penn's School of Engineering and Applied Science. Other members of Gianola's lab, postdoctoral researcher Mo-Rigen He and graduate student Jungho Shin, contributed to the study. They collaborated with Gunther Richter of the Max Planck Institute for Intelligent Systems. "Nanotechnology is not just about making things smaller," Chen said, "it's also about different properties that arise in materials at the nanoscale." "When you make these really small structures," Gianola said, "they're often grown from the bottom up, in an atom-by-atom, layer-by-layer process, and that can give you a much more pristine structure than if you were to take a big block of metal and whittle it down. In addition, the atoms on the surface comprise a much larger proportion of the total and can control the properties of the nanoscale material." The researchers grew palladium nanowires through a vapor deposition method at high temperature, which provided each atom with the time and energy to move around until it found its preferred spot in the metal's crystalline structure. Sprouting from a substrate like blades of grass, the team used a microscopic robotic manipulator to painstakingly pluck the wires and attach them to their testing platform inside an electron microscope. This platform, developed in conjunction with Sandia National Laboratory, functions like an industrial mechanical testing machine at the nanoscale. Welding a nanowire to a grip attached to a series of slanted bars that expand when heated by an electric current, the researchers could then stretch the nanowire in a controlled way. By repeatedly ramping up the voltage to a different maximum and bringing it down at the same rate, the researchers could pinpoint when the first irreversible deformation in the wire occurred. "Just pulling it until it fails doesn't tell you exactly where and how that failure began," Gianola said. "Our goal was to deduce the point where the first of the nanowire's atoms begin to shift out of their original positions and form a mobile defect." Computational studies suggested this point could be revealed by studying the temperature dependence of failure. Absent defect-free nanowires to run physical experiments upon, earlier theories and analyses suggested that the relationship between temperature and strength was deterministic; knowing the temperature would allow one to estimate a nanowire's failure limit. By conducting their stretching experiments at various temperatures, the researchers were able to chart these failure points. Surprisingly, they found the wires' strengths scattered over a range of values, even when stretched at the same temperature. "We've been able to verify," Chen said, "through experiment, and not just theory, that this process is thermally activated, and that there's a large randomness to the process. Normally you can say a bulk material has certain strength at a certain temperature, but you have to take a different approach to specify the strength of the nanowire. Depending on the temperature you're concerned with, even the distribution of strengths can vary drastically." That this distribution occurred over a relatively large range of values meant that the thermal activation barrier, the amount of energy necessary to jump-start the nucleation of the first defect, was relatively low. Comparing the size of this thermal activation barrier to other atomistic mechanisms gave the researchers some insight into what was driving this process. "Diffusion of atoms on a surface," Gianola said, "is the only mechanism that has this low thermal activation barrier. Surface diffusion is atoms hopping around, site to site, somewhat chaotically, almost like a fluid. A palladium atom sitting inside the bulk of the wire has 12 neighbors, and has to break most of those bonds to move around. But one on the surface might have only three or four to break." Understanding the origin of the distribution of strengths in nanostructures will allow for more rational design of devices. "Until recently," Gianola said, "it's been very difficult to make defect-free nanowires. But now that we can, there's a reason to care about how they fail. Their strengths are nearly a thousand times what you would get from the bulk material with defects -- in this experiment, we observed, to our knowledge, the highest strengths ever measured in that crystal structure of metal -- so they're going to be attractive to use in all sorts of devices." Story Source: The above story is based on materials provided by University of Pennsylvania. Note: Materials may be edited for content and length. Journal Reference: Lisa Y. Chen, Mo-rigen He, Jungho Shin, Gunther Richter, Daniel S. Gianola. Measuring surface dislocation nucleation in defect-scarce nanostructures. Nature Materials, 2015; DOI: 10.1038/nmat4288

Clean streets: Innovative hybrid-electric powertrain for road sweepers

 

The natural  gas-electric hybrid project vehicle, for which Empa, the ETH Zürich University and the road sweeper manufacturer Bucher Municipal developed a pioneering electric hybrid drive in a joint CTI project. Credit: Image courtesy of Empa Sweepers keep our pavements, paths and roads clean. For this purpose they are equipped with a powertrain for moving the vehicle, a blower for sucking up the dirt and debris and brushes for cleaning the ground. The energy for the operation of all the components is currently provided by a diesel engine; a sophisticated hydraulic distribution system guides the relevant share of the energy to the various components. Such vehicles have long operating times of six to eight hours per day. With a consumption of more than five litres of diesel per hour, the annual consumption per vehicle amounts to around 10,000 litres. This is about ten times more than the typical consumption of a passenger car. A German study has estimated that the contribution of such working vehicles, e.g. road sweepers, municipal vehicles, dustbin lorries, etc., to the energy consumption of all road traffic is as high as 15 percent, despite the actual number of such vehicles being relatively small. Natural gas and electricity instead of diesel and hydraulics Bucher Municipal is based in Niederweningen in Switzerland and is the European market leader in compact sweeping vehicles. Empa and ETH Zürich carry out research on future powertrain technologies. As part of a project supported by CTI, Commission for Technology and Innovation, the partners have developed an innovative powertrain for road sweepers. The project goals were ambitious: the energy consumption compared with today's diesel vehicles was to be reduced by 45 percent and the total costs of the vehicle (purchase, interest, operating costs) were not allowed to exceed the costs of the current technology. To achieve this, the researchers and engineers have replaced today's conventional hydraulic power distribution with more efficient electric drive systems. Instead of a diesel engine with a hydraulic pump, a small gas engine with a power generator now acts as the drive source. In addition, a modern energy management system controls the interaction between the components. The results are now available: compared to a conventional diesel-powered road sweeper, the electric hybrid sweeper driven by natural gas consumes less than half as much energy during the standard cycle for sweeping vehicles. Thanks to the lower carbon content in natural gas, the CO2 emissions have decreased by as much as 60 percent, and with biogas blending this effect is even higher. The significantly lower consumption, in combination with lower fuel prices for natural gas, result in a significant reduction in operating costs, which more than compensates for the higher initial purchasing cost. Implementation project in the pipeline The hybrid drive system has a modular design. This means that a petrol, liquefied petroleum gas or diesel engine could be installed instead of a natural gas engine. If a hydrogen-powered fuel cell or a significantly larger battery is used instead of an internal combustion engine with power generator, purely electrical operation would also be possible. This modular drive concept will allow Bucher Municipal to cater for a wide range of different customer needs in the future. The management of Bucher Municipal is therefore planning to further develop the electric hybrid drive's modular platform and has already launched an internal concept study to this end. In this context, further work on reducing costs, optimising operation and packaging must be carried out in the areas of the power battery, the onboard power generator and the overall vehicle. In parallel to this, the production processes in Niederweningen will be analysed with regard to vehicle electrification. The aim is to bring an innovative sweeping machine onto the market in the foreseeable future. Story Source: The above story is based on materials provided by Empa. Note: Materials may be edited for content and length.

Tin follows zinc: Stretchable ceramics made by flame technology

 

Yogendra Kumar Mishra presents the stretchable ceramic made from tin oxide. Credit: Photo/Copyright: Claudia Eulitz, CAU Synthesizing nanoscale materials takes place within high-tech laboratories, where scientists in full-body suits keep every grain of dust away from their sensitive innovations. However, scientists at Kiel University proved that this is not always necessary. They have successfully been able to transfer the experience from furnace to laboratory while synthesizing nanoscale materials using simple and highly efficient flame technology. This "baking" of nanostructures has already been a great success using zinc oxide. The recent findings concentrate on tin oxide, which opens up a wide field of possible new applications. The material scientists published their latest research data in the scientific journal Advanced Electronic Materials. Metal oxides in bulk form are generally brittle, which limits their desired utilizations. Their one-dimensional (1D) structures, such as belt-like nanostructures, exhibit much more application potential because of their high surface to volume ratio. This ratio induces extraordinary physical and chemical properties, including a high degree of bendability. "However, 1D nanostructures are still difficult to use, because integrating them in real devices is a challenging task. To overcome this issue, we have developed three-dimensional (3D) macroscopic material from 1D tin oxide belt-like nanostructures. The resulting ceramic networks exhibit most of the nanoscale properties, including flexibility. It can therefore be freely utilized for any desired application. We are very pleased that our recently introduced flame transport synthesis method on the basis of zinc oxide now enables the simple synthesis of interconnected 3D networks from tin oxide," says Dr Yogendra Kumar Mishra, group leader of the working group "Functional Nanomaterials" at Kiel University, and main author of the study. "The fascinating part is the structure of the single belt-like nanostructures delivered by this synthesis on the basis of tin oxide crystal structure. In contrast to ceramic produced with zinc oxide, which leads to very short tetrapod structures, tin oxide gives long, flat structures. They are just like fettucine," compares Professor Rainer Adelung, Chairperson of the Functional Nanomaterials group. "And these long flat noodles grow together in a very specific way: In the oven used for the synthesis, temperatures stay just below the melting point of tin oxide. Thus, the noodles find specific interconnection points by kinetics instead of thermodynamics. Each junction is forced into a well-defined angle following strict geometric principles, which are based on so-called twinning defects, as further confirmed by simulation studies," adds Professor Lorenz Kienle, Chairperson of the Synthesis and Real Structure group. The structural design of the tin oxide 3D network, meaning the grown-together noodles, was investigated in detail using transmission electron microscopy. "The 3D networks from tin oxide exhibit interesting features, such as electrically conducting, high temperature stable, very soft and stretchable architecture, and could thus be interesting for several technological applications," says Dr Mishra. For example, a portable electronic sensing device has already been fabricated. And, according to Mishra, it demonstrates significant potential for UV light or gas sensing applications. "Until now, we have tested sensing applications. Further potential applications could also be flexible and stretchable electronic devices, luminescent actuators, batteries, smart cloths or sacrificial templates for the growth of new materials." This work has been performed in co-operation with Professor Ion Tiginyanu and his team members from the Technical University of Moldova, Moldova. The three Kiel scientists know: "Development of such 3D network materials from tin oxide, with geometry determining defects made by flame transport synthesis at Kiel University is a very interesting step forward into the future of nanostructure growth and applications." Story Source: The above story is based on materials provided by Christian-Albrechts-Universitaet zu Kiel. Note: Materials may be edited for content and length. Journal Reference: Ingo Paulowicz, Viktor Hrkac, Sören Kaps, Vasilii Cretu, Oleg Lupan, Tudor Braniste, Viola Duppel, Ion Tiginyanu, Lorenz Kienle, Rainer Adelung, Yogendra Kumar Mishra. Three dimensional SnO2 nanowire networks for multifunctional applications: From high temperature stretchable ceramics to ultraresponsive sensors. Advanced Electronic Materials, June 2015 DOI: 10.1002/ aelm.201500081

Photo Essay : Stunning Seaside Towns on Italy’s Mediterranean

When I think of the tiny towns nestled along Italy’s Mediterranean coast, I think of the multi-hued sherbet cubes tucked into cliffsides, varying shades of aquamarine water with colorful boats bobbing up and down, gray pebbly beaches with lounge chairs and colorful umbrellas, steep craggy coastlines that abruptly drop into the forcefully churning surf and ports where fishmongers row in their catch of the day. And though many of them possess these same characteristics, each one has its own history, charm, and reasons to visit.  Enjoy this photo essay of some of the best seaside towns along the Mediterranean in Italy. Sanremo Sanremo is one of the westernmost town, so very close to the French border.  It’s home to a casino, palm trees and a luxurious looking Marina! Genoa Genoa is one of the largest cities on the Northern Italy Coast.  It’s a large industrial port city and actually was Italy’s first. Lerici Lerici is in the province of Liguria.  It’s considered part of the Italian Riviera. And in case you can’t tell from the photo…it’s a port town. Manarola Cinque Terre means five towns. It is literally made up of five tiny villages, all connected by ancient paths.  This photo is of Manarola, one of the most recognizable in the Cinque Terre. Portofino Another hugely popular town on the Italian Riviera is Portofino.  The small fishing village was supposedly discovered by Romans and named for dolphins.  The stunning half-moon shape of the harbor is best viewed from above, as in this photo. Livorno Livorno is an ancient tangle of canals and walls.  It’s also known as Leghorn, and there is a breed of chicken named after the city.  Rumor has it that it’s how Foghorn Leghorn got his name. Monterosso al Mare Another tiny town included in the Cinque Terre.  I love how the little beach is anchored on either side by the huge rocks.  And check out the walkway just clinging to that cliff face on the right. Vernazza This unique town of the Cinque Terre wraps completely around the coast, offering spectacular views. The Doria Castle, which was erected to protect against pirates and the church’s octagonal bell tower are two notable sights. Camogli amogli, which means houses close together in Italian, is a tiny fishing village on the coast.  If this picture is any indication, it looks adorable. Riomaggiore The southernmost town in the Cinque Terre group.  It sits on the Gulf of Genoa and is known for its wine and aquariums. Portovenere This tiny fishing village is a UNESCO World Heritage Site.  Its name is said to come from a temple to the goddess Venus. I know I’d feel like a goddess if I spent any time there. Piombino Piombino is an ancient Etruscan port.  The area attracts snorkelers and divers from all over the world.  There is also a Marine Biology Center and aquarium. Nettuno Nettuno, named for the Roman god Neptune, is located in the Lazio region.  It’s a popular spot for sunbathers since it’s a stop on the local train out of Rome. Gaeta Gaeta has had a turbulent history, but is currently an important seaport for both fishing and oil.  You can also get tiella here, which is a unique combination of a pizza and calzone. I can imagine eating one on that stretch of golden sand. Sorrento Sorrento is a tourist destination in the Campania region, which overlooks the beautiful Bay of Naples.  Other than delicious views and luxury resorts, Sorrento is known for its Limoncello.  How ’bout a chilled sip while drooling over this view? Positano Made famous by the scenes shot here in Under the Tuscan Sun, this gem had been frequented by celebs long before that. Located on the Amalfi coast,  Positano was a medieval port and boasts two separate beaches- both equally beautiful. Atrani Atrani, located a few minutes drive from Amalfi, is one of the most romantic towns of them all.  The location is stunning,even dramatic, and looking at this photo it’s clear why.   Their abundance of fish is evident in the Sagre del Pesce Azzurro, the celebratory fish festival. Praiano Praiano, located between Positano and Amalfi, is home to the famed Grotto Esmerela, or Green Grotto.  Not quite as talked about as the famous Blue Grotto on Capri, but with views like this, how could it not be beautiful? Cetara Once used by pirates as a naval base and later destroyed by Turkish pirates in the 16th century, this tiny gem is known for its anchovy and tuna production.  Oh, and it looks dreamy at dusk, wouldn’t you agree? Tropea Tropea is situated on a reef in the toe of the boot, the Calabria region.  From the photo, we can tell it’s a favorite spot of beach-goers.  The people seem ant-like in relation to the giant sandstone cliffs. Amalfi Located at the mouth of a ravine called Monte Cerrato, Amalfi is certainly one of the most well-known towns.  An entire section of Italy’s southern coast is named after it.  Amalfi is home to a Duomo, campanile (bell tower) and hosts an ancient regatta once every four years. Note : Though many of these little villages are set in more specific areas of Italy’s coastline, such as the Ligurian and Tyrrhenian Seas, I have grouped these bodies of water all together as part of the larger Mediterranean Sea for the pupose of this piece. Photo Credits : Mike Flemming / Perrimoon / Alex Scarcella / Rob Inh00d / Extravigator / Conormac / LeeMcarthur / Tylerc083 / RoSSella Rebonato / [MP] / Nick’s Pics /  Raffaelesergi1977 / Sunshinecity / Michaelwm25 / S J Pickney / Robin Locker / Allerina & Glen MacLarty / MHJohnston / Ale Bovini / Simo0082 / Paul and Jill   Traveling to Italy?  Click here to find out how I can help plan your trip!