515 research outputs found

    Navigating chemical reaction space with a steering wheel

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    Autonomous reaction network exploration algorithms offer a systematic approach to explore mechanisms of complex chemical processes. However, the resulting reaction networks are so vast that an exploration of all potentially accessible intermediates is computationally too demanding. This renders brute-force explorations unfeasible, while explorations with completely pre-defined intermediates or hard-wired chemical constraints, such as element-specific coordination numbers, are not flexible enough for complex chemical systems. Here, we introduce a Steering Wheel to guide an otherwise unbiased automated exploration. The Steering Wheel algorithm is intuitive, generally applicable, and enables one to focus on specific regions of an emerging network. It also allows for guiding automated data generation in the context of mechanism exploration, catalyst design, and other chemical optimization challenges. The algorithm is demonstrated for reaction mechanism elucidation of transition metal catalysts. We highlight how to explore catalytic cycles in a systematic and reproducible way. The exploration objectives are fully adjustable, allowing one to harness the Steering Wheel for both structure-specific (accurate) calculations as well as for broad high-throughput screening of possible reaction intermediates.Comment: 40 pages, 10 figures, 1 tabl

    Padrões de acúmulo de proteínas e carboidratos durante a embriogênese somática de Acca sellowiana

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    The aim of this work was to quantify the protein, starch and total sugars levels during histodifferentiation and development of somatic embryos of Acca sellowiana Berg. For histological observations, the samples were dehydrated in a battery of ethanol, embedded in historesin and stained with toluidine blue (morphology), coomassie blue (protein bodies) and periodic acid-Schiff (starch). Proteins were extracted using a buffer solution, precipitated using ethanol and quantified using the Bradford reagent. Total sugars were extracted using a methanol-chloroform-water (12:5:3) solution and quantified by a reaction with anthrone at 0.2%. Starch was extracted using a 30% perchloric acid solution and quantified by a reaction with anthrone at 0.2%. During the somatic embryogenesis' in vitro morphogenesis and differentiation processes, the total protein levels decreased and the soluble sugars levels increased during the first 30 days in culture and remained stable until the 120th day. On the other hand, total protein levels increased according to the progression in the developmental stages of the somatic embryos. The levels of total sugars and starch increased in the heart and cotyledonary stages, and decreased in the torpedo and pre-cotyledonary stages. These compounds play a central role in the development of somatic embryos of Acca sellowiana. © 2009 Embrapa Informação Tecnológica.O objetivo deste trabalho foi quantificar os teores de proteína, amido e açúcares totais durante a histodiferenciação e desenvolvimento dos embriões somáticos em Acca sellowiana Berg. Para as observações histológicas, as amostras foram desidratadas em uma bateria de etanol, emblocadas em historesina e coradas com azul de toluidina (morfologia), azul de coomassie (corpos proteicos) e reativo ácido periódico de Schiff (amido). As proteínas foram extraídas usando uma solução tampão, precipitadas usando etanol e quantificadas por meio do reativo de Bradford. Os açúcares totais foram extraídos usando uma solução metanol-clorofórmioágua (12:5:3) e quantificados pela reação com antrona a 0,2%. O amido foi extraído usando uma solução de ácido perclórico a 30% e quantificado pela reação com antrona a 0,2%. Durante a diferenciação e morfogênese in vitro da embriogênese somática, os teores de proteínas totais decresceram e os açúcares solúveis aumentaram durante os 30 primeiros dias em cultura e permaneceram constantes até os 120 dias. Por outro lado, os teores das proteínas totais apresentaram incremento de acordo com a progressão nos estádios de desenvolvimento dos embriões somáticos. Os teores de açúcares totais e de amido aumentaram nos estádios cordiforme e cotiledonar e diminuíram nos estádios torpedo e pré-cotiledonar. Esses compostos exercem papel central no desenvolvimento de embriões somáticos de Acca sellowiana.Fil: Cangahuala-Inocente, Gabriela Claudia. Universidade Federal de Santa Catarina; BrasilFil: Steiner, Neusa. Universidade Federal de Santa Catarina; BrasilFil: Maldonado, Sara Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Guerra, Miguel Pedro. Universidade Federal de Santa Catarina; Brasi

    uncertainty and complexity in the context of COVID-19

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    Although the first coronavirus disease 2019 (COVID-19) wave has peaked with the second wave underway, the world is still struggling to manage potential systemic risks and unpredictability of the pandemic. A particular challenge is the “superspreading” of the virus, which starts abruptly, is difficult to predict, and can quickly escalate into medical and socio-economic emergencies that contribute to long-lasting crises challenging our current ways of life. In these uncertain times, organizations and societies worldwide are faced with the need to develop appropriate strategies and intervention portfolios that require fast understanding of the complex interdependencies in our world and rapid, flexible action to contain the spread of the virus as quickly as possible, thus preventing further disastrous consequences of the pandemic. We integrate perspectives from systems sciences, epidemiology, biology, social networks, and organizational research in the context of the superspreading phenomenon to understand the complex system of COVID-19 pandemic and develop suggestions for interventions aimed at rapid responses.publishersversionpublishe

    The Global Campaign (GC) to Reduce the Burden of Headache Worldwide. The International Team for Specialist Education (ITSE).

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    The social perception of headache, everywhere at low levels in industrialised countries, becomes totally absent in developing ones. Headache disorders came into the World Health Organization\u27s strategic priorities after publication of the 2001 World Health Report. Among the leading causes of disability, migraine was ranked 19th for adults of both sexes together and 12th for females. The Global Campaign (GC) to Reduce the Burden of Headache Worldwide was planned by the major international headache organizations together with WHO in order to identify and remove those cultural, social and educational barriers recognised as responsible factors for the inadequate treatment of headache disorders worldwide. Within the GC activities, the education of the medical body will represents a central pillar. An International Team for Specialist Education (ITSE) has been created to train physicians from all over the world through the acquisition of a university level Master Degree in Headache Medicine. Once trained as headache specialists, physicians will become trainers, offering education in this field to other health care providers in their own countries. In this way they will give life to a cultural chain raising awareness locally of headache, its burden and its medical control

    Forage potential of native ecotypes of Paspalum notatum and P. guenoarum

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    The Paspalum genus includes several species that are important for livestock in Rio Grande do Sul, such as P. notatum and P. guenoarum, typical of native pastures of the Pampa biome. The aim of this study was to investigate forage production and chemical composition of four ecotypes of these species in relation to the cv. ‘Pensacola’ (P. notatum). Ecotypes of P. guenoarum (Azulão and Baio) and P. notatum (André da Rocha and Bagual) and the cv. ‘Pensacola’ were evaluated for two years, during which four cuts/year were made. The work was carried out under field conditions at the Agronomic Experimental Station of the Federal University of Rio Grande do Sul (30°05’S; 51°39’W), in a completely randomized design. P. guenoarum stood out for higher productivity and greater tolerance to cold; the Azulão ecotype showed more autumn production in relation to the other ecotypes. Crude protein content ranged from 14 (Baio) to 15% (‘Pensacola’); for neutral detergent fiber, the variation was 68 (Azulão) to 71% (‘Pensacola’) and for acid detergent fiber there was a variation of 38 (‘Pensacola’) to 43% (Baio). The data demonstrates the potential of native genotypes for use as cattle feeding in southern Brazil

    Padrões de acúmulo de proteínas e carboidratos durante a embriogênese somática de Acca sellowiana

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    The aim of this work was to quantify the protein, starch and total sugars levels during histodifferentiation and development of somatic embryos of Acca sellowiana Berg. For histological observations, the samples were dehydrated in a battery of ethanol, embedded in historesin and stained with toluidine blue (morphology), coomassie blue (protein bodies) and periodic acid–Schiff (starch). Proteins were extracted using a buffer solution, precipitated using ethanol and quantified using the Bradford reagent. Total sugars were extracted using a methanol-chloroform-water (12:5:3) solution and quantified by a reaction with anthrone at 0.2%. Starch was extracted using a 30% perchloric acid solution and quantified by a reaction with anthrone at 0.2%. During the somatic embryogenesis’ in vitro morphogenesis and differentiation processes, the total protein levels decreased and the soluble sugars levels increased during the first 30 days in culture and remained stable until the 120th day. On the other hand, total protein levels increased according to the progression in the developmental stages of the somatic embryos. The levels of total sugars and starch increased in the heart and cotyledonary stages, and decreased in the torpedo and pre-cotyledonary stages. These compounds play a central role in the development of somatic embryos of Acca sellowiana.O objetivo deste trabalho foi quantificar os teores de proteína, amido e açúcares totais durante a histodiferenciação e desenvolvimento dos embriões somáticos em Acca sellowiana Berg. Para as observações histológicas, as amostras foram desidratadas em uma bateria de etanol, emblocadas em historesina e coradas com azul de toluidina (morfologia), azul de coomassie (corpos proteicos) e reativo ácido periódico de Schiff (amido). As proteínas foram extraídas usando uma solução tampão, precipitadas usando etanol e quantificadas por meio do reativo de Bradford. Os açúcares totais foram extraídos usando uma solução metanol-clorofórmio-água (12:5:3) e quantificados pela reação com antrona a 0,2%. O amido foi extraído usando uma solução de ácido perclórico a 30% e quantificado pela reação com antrona a 0,2%. Durante a diferenciação e morfogênese in vitro da embriogênese somática, os teores de proteínas totais decresceram e os açúcares solúveis aumentaram durante os 30 primeiros dias em cultura e permaneceram constantes até os 120 dias. Por outro lado, os teores das proteínas totais apresentaram incremento de acordo com a progressão nos estádios de desenvolvimento dos embriões somáticos. Os teores de açúcares totais e de amido aumentaram nos estádios cordiforme e cotiledonar e diminuíram nos estádios torpedo e pré‑cotiledonar. Esses compostos exercem papel central no desenvolvimento de embriões somáticos de Acca sellowiana

    Headache yesterday in Europe

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    BACKGROUND: Surveys enquiring about burden of headache over a prior period of time (eg, 3 months) are subject to recall bias. To eliminate this as far as possible, we focused on presence and impact of headache on the preceding day (“headache yesterday”). METHODS: Adults (18-65 years) were surveyed from the general populations of Germany, Italy, Lithuania, Luxembourg and the Netherlands, from a work-force population in Spain and from mostly non-headache patient populations of Austria, France and UK. A study of non-responders in some countries allowed detection of potential participation bias where initial participation rates were low. RESULTS: Participation rates varied between 11% and 59% (mean 27%). Non-responder studies suggested that, because of participation bias, headache prevalence might be overestimated in initial responders by up to 2% (absolute). Across all countries, 1,422 of 8,271 participants (15-17%, depending on correction for participation bias) had headache yesterday lasting on average for 6 hours. It was bad or very bad in 56% of cases and caused absence from work or school in 6%. Among those who worked despite headache, 20% reported productivity reduced by >50%. Social activities were lost by 24%. Women (21%) were more likely than men (12%) to have headache yesterday, but impact was similar in the two genders. CONCLUSIONS: With recall biases avoided, our findings indicate that headache costs at least 0.7% of working capacity in Europe. This calculation takes into account that most of those who missed work could make up for this later, which, however, means that leisure and social activities are even more influenced by headache

    Genomic Resources Notes Accepted 1 August 2014–30 September 2014

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    This article documents the public availability of (i) transcriptome sequence data, assembly and annotation, and single nucleotide polymorphisms ( SNP s) for the cone snail Conus miliaris ; (ii) a set of SNP markers for two biotypes from the Culex pipiens mosquito complex; (iii) transcriptome sequence data, assembly and annotation for the mountain fly Drosophila nigrosparsa ; (iv) transcriptome sequence data, assembly and annotation and SNP s for the Neotropical toads Rhinella marina and R. schneideri ; and (v) partial genomic sequence assembly and annotation for 35 spiny lizard species (Genus Sceloporus ).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110107/1/men12340-sup-0004-AppendixS4.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/110107/2/men12340-sup-0003-AppendixS3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/110107/3/men12340-sup-0002-AppendixS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/110107/4/men12340-sup-0005-AppendixS5.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/110107/5/men12340.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/110107/6/men12340-sup-0001-AppendixS1.pd

    Evaluation of a Small, In-field Runoff Collector

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    Proceedings of the 1999 Georgia Water Resources Conference, March 30 and 31, Athens, Georgia.Increased environmental concern about surface water pollution has heightened the need for small, in-field runoff collectors to assess the impact of land management practices without altering the landscape. We modified a surface flow sampler designed for sheet flow in Coastal Plain soils. Modifications were made to accommodate steep slopes (3 to 15% ), large flow rates, and channelized flow which are common in the Southern Piedmont. The runoff collector consists of two sample splitters (10x and 100x) and two sample collectors. Runoff collector performance was evaluated in the laboratory to determine percent flow captured by 10x and 100x splitters relative to flow rate and slope. Average flow captured on a 5% slope was 10.3% for 10x and 1.8% for the l00x. When the slope was increased to 12% the percent flow capture also increased slightly, 10.4% for l0x and 2.3% for l00x. It was determined that the small, in-field runoff collector captures runoff volumes at specific rates at fairly consistent ratios.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202 with partial funding provided by the U.S. Department of Interior, geological Survey, through the Georgia Water Research Insttitute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors
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