630 research outputs found

    Análise quantitativa de rna mensageiros, proteínas e atividades enzimáticas no estudo da rede de regulação controlada pelo gene Opaco-2

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    The Opaque-2 (O2) gene encodes a transcriptional activator specifically expressed for grain development of maize. o2 mutants have an opaque and chalky kernel, with a decrease in zein storage protein content, and an increase in the proportions of lysine and tryptophan. In this review, we present recent results investigating genetic properties of the O2 network, using transcriptome and proteome approaches, associated with measurements of activities of enzymes of the aspartate pathway and lysine degradation. The structural polymorphism at the O2 locus was investigated by RFLP in a collection of 51 maize inbred lines. Most polymorphic sites were found outside the coding regions. We then searched for relationships between RFLP polymorphism and (i) mRNA abundance of O2 and of known or suspected target genes, (ii) activity of SDH and (iii) amount of zein isoforms. Polymorphic restriction sites in the 5' upstream regions of the O2 gene were found associated with O2 mRNA abundance (three sites) and the amount of two 19 kDa alpha-zein isoforms (two sites). One restriction site on the 3' side of the O2 gene was found associated with Lor/Sdh mRNA abundance. Our results indicate relationships between polymorphism at the O2 locus and the expression of some of its target genes. Evidence of these associations has to be confirmed on larger samples, and the analysis of the O2 gene sequence should allow more precise testing of the actual involvement of O2 polymorphism in its own transcriptional expression, and in the expression of its target genes.O gene Opaco-2 (O2), expresso especificamente no grão de milho, transcreve para um fator de transcrição da família "leucine-zipper". Mutantes o2 apresentam grãos opacos, redução na quantidade de zeínas e aumento na proporção de lisina e triptofano. Genes cuja expressão é controlada diretamente pelo O2 são conhecidos (alfa-zeínas de 22 kDa, beta-zeínas de 14 kDa, b-32 e cyPpdk1). Nesta revisão, nós apresentamos resultados da caracterização genética de genes relacionados com o O2, através de abordagens de transcritoma, proteoma e de atividades enzimáticas da via metabólica do aspartato e da degradação da lisina. O polimorfismo do locus O2 foi avaliado utilisando-se a técnica de RFLP em 51 linhagens de milho. A maioria dos polimorfismos foi observada nas regiões não codificadoras da proteína. Análises de correlação foram realizadas entre os polimorfismos de RFLP e (i) quantidade de RNAm do O2, cyPpdk, Lor/Sdh e Ahas (ii) quantidade de isoformas de zeínas e (iii) atividade da enzima SDH. Sítios polimórficos foram correlacionados com a quantidade de RNAm do próprio O2, do gene Lor/Sdh e com a quantidade de duas isoformas de a-zeinas de 19 kDa. Nossos resultados indicam a presença de relações entre o polimorfismo do locus O2 e o nível de expressão de genes sob o seu controle. A utilização de um maior número de linhagens e o uso de dados de seqüência do O2 permitirá uma análise precisa da conseqüência do polimorfismo deste fator de transcrição sobre o controle do seu próprio nível de expressão e dos genes por ele controlados

    A solution for funding the development of technology in oilwell drilling

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    This article proposes a novel methodology to solve an existing gap in benchmark definition by the adoption of statistically defined benchmarks as references to test products or technical procedures. In a win–win partnership, remuneration is made upon realistic bases of comparison being proportional to existing risks. However, establishing values for benchmarks is rarely unanimous if asked to different persons involved in drilling analysis. Conventional benchmarking, which enhances few results and leaves aside poor operational performances, produces references that do not properly represent the geological environment. Nonetheless, when testing new products, it serves as reference to remunerate suppliers. The review of an optimization program, which resulted in a world record of drilling rate of penetration, reveals the financial magnitude of the savings produced, proposing the method discussed as a reliable solution to the development of technology.publishedVersio

    Exfoliative Toxins of Staphylococcus aureus

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    Virulent strains of Staphylococcus aureus secrete exfoliative toxins (ETs) that cause the loss of cell‐cell adhesion in the superficial epidermis. S. aureus ETs are serine proteases, which exhibit exquisite substrate specificity, and their mechanisms of action are extremely complex. To date, four different serotypes of ETs have been identified and three of them (ETA, ETB and ETD) are associated with toxin‐mediated staphylococcal syndromes related to human infections leading to diseases of medical and veterinary importance

    A big data approach to identify the loss of coastal cultural ecosystem services caused by the 2019 Brazilian oil spill disaster

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    In August 2019, the Northeast coast of Brazil was impacted by an extensive oil spill, with immediate effects on marine and coastal ecosystems and significant impacts on tourism and food security. The human dimension of those impacts also includes the loss of cultural ecosystem services (CES); the non-material benefits stemming from strongly rooted cultural practices and relationships with nature. CES are of great importance for local residents and visitors that flock to Brazilian iconic beaches, however, they are difficult to measure using traditional assessment methods due to their subjective and non-tangible nature. Here, we use a big data approach to assess and map the loss of CES in the Northeast coast of Brazil caused by the recent oil spill. We analysed 2,880 digital images (published on the image sharing platform Flickr) taken before and during the disaster in affected locations, using a combination of automated techniques. Results showed a sharp decline in the number of users posting photos of locations affected by oil spill, and a decline in photos representing landscape and cultural appreciation. Our big data approach provides a fast and automated way to assess CES at large spatial scales that can be used to monitor the social impacts of environmental disasters.Peer reviewe

    Public awareness and engagement in relation to the coastal oil spill in northeast Brazil

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    Social media data is a rich source of information to assess human activities in catastrophic events. Here, we use social media data to understand how the 2019 Brazilian oil spill influenced social attitudes. Data were collected from the globally popular Instagram platform between August 1, 2019 and March 1, 2020. First, we manually identified the 5 most popular (portuguese language) hashtags related to the oil spill #oleonononordeste;#desastreambiental;#ma rsemoleo;#sosnordeste;#ma rsempetroleo. In the sequence, we collected information on captions, post metadata and users associated with posts retrieved using the selected hashtags. We identified a total of 7,413 posts. These posts were grouped in topics: government (47.76%), protest (24.37%), volunteers (24.45%), biodiversity (0.003%), origin (0.006%), tourism (0.008%) and others (0.016%). All topics had the peak of posts in October and November 2019. Nevertheless, interest in the oil spill was temporary, with most posts appearing in the 2-4 months after the beginning of the disaster. Our findings illustrate the enormous potential of using social media data for understanding and monitoring human engagement with environmental disasters, but also suggest that conservationists and environmental groups may only have a limited 'window of opportunity' to engage and mobilize public support for remediation and restoration efforts.Peer reviewe
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