2,138 research outputs found

    In vitro determination of extracellular proteins from xylella fastidiosa

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The phytopathogen Xylella fastidiosa causes economic losses in important agricultural crops. Xylem vessel occlusion caused by biofilm formation is the major mechanism underlying the pathogenicity of distinct strains of X. fastidiosa. Here, we provide a detailed in vitro characterization of the extracellular proteins of X. fastidiosa. Based on the results, we performed a comparison with a strain J1a12, which cannot induce citrus variegated chlorosis symptoms when inoculated into citrus plants. We then extend this approach to analyze the extracellular proteins of X. fastidiosa in media supplemented with calcium. We verified increases in extracellular proteins concomitant with the days of growth and, consequently, biofilm development (330 days). Outer membrane vesicles carrying toxins were identified beginning at 10 days of growth in the 9a5c strain. In addition, a decrease in extracellular proteins in media supplemented with calcium was observed in both strains. Using mass spectrometry, 71 different proteins were identified during 30 days of X. fastidiosa biofilm development, including proteases, quorum-sensing proteins, biofilm formation proteins, hypothetical proteins, phage-related proteins, chaperones, toxins, antitoxins, and extracellular vesicle membrane components.The phytopathogen Xylella fastidiosa causes economic losses in important agricultural crops. Xylem vessel occlusion caused by biofilm formation is the major mechanism underlying the pathogenicity of distinct strains of X. fastidiosa. Here, we provide a de7Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [2001/07533-7, 2012/51580-4]Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES, Computational Biology Program)CAPESFAPESP [2011/50268-4]CAPES (Computational Biology Program)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Text and Interaction: A Performance Analysis Written in Present Evaluations of Pedagogy Students in the Distance Mode

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    This study aims to verify the use and mastery of linguistic knowledge in the writing process of Pedagogy students, in the form of Distance Education. The methodology was based on an exploratory analysis of texts produced in the face-to-face assessments that occurred in the first half of 2017. In the analysis of the answers, a descriptive graph of the errors and inadequacies observed was presented. The results show the commitment of writing to the meaning of the text, since this is a result of it. With this study, it was noticed that the university students have presented difficulties in expressing, in writing, their thoughts, their understandings and their opinions in an adequate and coherent way. Therefore, in order to minimize the anxiety experienced by these students at the time of writing, it is suggested that through the Instrumental Portuguese class, which part of the curriculum is, the linguistic aspects responsible for the production of meaning in texts and the interaction of the interlocutors. In order to meet the needs of undergraduate students, in the specific case of Pedagogy, since it concerns the training of teachers, professionals who will work in the literacy of children and young people and need to prioritize knowledge about language, reading and writing of these students

    Effects of consumption of galactooligosaccharides obtained through whey enzymatically modified on the faecal flora and nutritional parameters of hamsters

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    The aim of this research was to evaluate the influence of wheyenzymatically modified rich in galactooligosaccharides in thenutritional characteristics and effects in the microflora of cecumcontents by the study with Golden Syrian hamsters (Mesocricetusauratus) for 28 days (controlled conditions). Three isoproteic dietswere prepared (20% w/w): C (casein), W (whey) and G (wheymodified). The groups studied differed positively from the C regardingfeed and protein efficiency ratio. The relationships (w/w) oforgan/body were found proportional in all diets. The counts ofprobiotics from the cecum contents the groups showed no difference.The pHs of studied groups were lower than C, this acidity can atimpairs the ability of pathogens to grow in the intestine. Resultssuggest that using whey enzymatically modified rich ingalactooligosaccharides could replace the standard diet withnutritional efficiency and possible inhibit the microorganismspathogenic without induce damage in health.Fil: Dos Santos Da Fonseca, Renata Aline. Universidade Federal Do Rio Grande; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Rodrigues Machado, Adriana. Universidade Federal Do Rio Grande; BrasilFil: Muniz Moreira, Lidiane. Universidade Federal Do Rio Grande; BrasilFil: Rodrigues, Rosane S.. Universidade Federal de Pelotas; BrasilFil: Machado, Mirian. Universidade Federal de Pelotas; BrasilFil: Souza Soares, Leonor A.. Universidade Federal Do Rio Grande; BrasilFil: Burkert, Carlos André V.. Universidade Federal Do Rio Grande; BrasilFil: Burkert, Janaína Fernandes de Medeiros. Universidade Federal Do Rio Grande; Brasi

    Temporal patterns of picoplankton abundance and metabolism on the western coast of the equatorial Atlantic Ocean

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    Picoplankton are central global carbon (C) cycling players and often dominate the ocean plankton communities, especially in low latitudes. Therefore, evaluating picoplankton temporal dynamics is critical to understanding microbial stocks and C fluxes in tropical oceans. However, the lack of studies on low-latitude picoplankton communities translates into a common conception that there is an absence of seasonality. Herein, we studied the temporal variation in abundance (measured by flow cytometry), and carbon flux (taking bacterial production and respiration as proxies) of the picoplanktonic community for the first time, as well as their environmental drivers in a low-latitude (05° 59’ 20.7″S 035° 05’ 14.6″W) Atlantic coastal station. We performed monthly samplings between February 2013 and August 2016 in a novel microbial observatory – hereafter called the Equatorial Atlantic Microbial Observatory – established on the northeastern Brazilian Atlantic coast. Our results revealed stability in temporal dynamics of picoplankton, despite a considerable inter-annual variation, with some related to the El Niño (ENSO) event in 2015. However, weak environmental relationships found were not enough to explain the variation in picoplankton’s abundance, which suggests that other factors such as biological interactions may lead to picoplankton abundance variation over time. Heterotrophic bacteria dominated picoplankton during the entire study period and between photosynthetic counterparts, and Synechococcus showed greater relative importance than picoeukaryotes. These results bring a novel perspective that picoplankton may exhibit more pronounced fluctuations in the tropical region when considering inter-annual intervals, and is increasing prokaryotic contribution to carbon cycling towards the equator.Fil: Menezes, Maiara. Universidade Federal do Rio Grande do Norte; BrasilFil: Junger, Pedro C.. Universidade Federal do São Carlos; BrasilFil: Kavagutti, Vinicius S.. Universidade Federal do São Carlos; BrasilFil: Wanderley, Bruno. Universidade Federal do Rio Grande do Norte; BrasilFil: Cabral, Anderson de Souza. Universidade Federal do Rio de Janeiro; BrasilFil: Paranhos, Rodolfo. Universidade Federal do Rio de Janeiro; BrasilFil: Unrein, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de San Martin. Instituto Tecnologico de Chascomus. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - la Plata. Instituto Tecnologico de Chascomus.; ArgentinaFil: Amado, André M.. Universidade Federal do Rio Grande do Norte; Brasil. Universidade Federal de Juiz de Fora; BrasilFil: Sarmento, Hugo. Universidade Federal do São Carlos; Brasi

    Vapd In Xylella Fastidiosa Is A Thermostable Protein With Ribonuclease Activity.

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    Xylella fastidiosa strain 9a5c is a gram-negative phytopathogen that is the causal agent of citrus variegated chlorosis (CVC), a disease that is responsible for economic losses in Brazilian agriculture. The most well-known mechanism of pathogenicity for this bacterial pathogen is xylem vessel occlusion, which results from bacterial movement and the formation of biofilms. The molecular mechanisms underlying the virulence caused by biofilm formation are unknown. Here, we provide evidence showing that virulence-associated protein D in X. fastidiosa (Xf-VapD) is a thermostable protein with ribonuclease activity. Moreover, protein expression analyses in two X. fastidiosa strains, including virulent (Xf9a5c) and nonpathogenic (XfJ1a12) strains, showed that Xf-VapD was expressed during all phases of development in both strains and that increased expression was observed in Xf9a5c during biofilm growth. This study is an important step toward characterizing and improving our understanding of the biological significance of Xf-VapD and its potential functions in the CVC pathosystem.10e014576

    Estudo da partição de fitase produzida por Aspergillus niger var. phoenicis utilizando bioconversão extrativa em sistemas de duas fases aquosas PEG/citrato

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    Existem diversos métodos tradicionais que são utilizados para extratir biomoléculas produzidas por fermentação convencional. Um método alternativo é o sistema de duas fases aquosas, o qual foi desenvolvido para a extração de bioprodutos. A bioconversão extrativa trata-se de um sistema de duas fases aquosas que integra cultivo microbiológico à produção e recuperação do bioproduto. Fitases são fosfatases específicas que estão envolvidas na catálise do ácido fitico. O objetivo deste trabalho foi estudar a partição da fitase produzida por A. niger var. phoenicis por bioconversão extrativa utilizando PEG/citrato. Realizou-se um planejamento fatorial completo 25, estudando as seguintes variáveis: massa molar do PEG, concentração do PEG, concentração de citrato, pH e agitação, onde obteve-se como variável-resposta o coeficiente de partição em atividade (KATIV). Neste trabalho conseguiu-se um coeficiente de partição de 25,77 utilizando MPEG (8000 g/mol), CPEG, (26,0% m/m), CCIT (20,0% m/m), pH (6,0) e agitação (100 rpm). Através dos resultados obtivos, pode-se concluir que a fitase utilizada no presente estudo apresenta uma tendência de particionar para a fase superior do sistema (K>1). A técnica de fermentação extrativa utilizando SDFA PEG/citrato demonstrou ser promissora para extração de fitase produzida por A. niger var. phoenicis, podendo ser aplicada na composição de rações comerciais

    LaMMos - Latching Mechanism based on Motorized-screw for Reconfigurable Robots and Exoskeleton Suits

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    Reconfigurable robots refer to a category of robots that their components (individual joints and links) can be assembled in multiple configurations and geometries. Most of existing latching mechanisms are based on physical tools such as hooks, cages or magnets, which limit the payload capacity. Therefore, robots re- quire a latching mechanism which can help to reconfigure itself without sacrificing the payload capability. This paper presents a latching mechanism based on the flexible screw attaching principle. In which, actuators are used to move the robot links and joints while connecting them with a motorized-screw and dis- connecting them by unfastening the screw. The brackets used in our mechanism configuration helps to hold maximum force up to 5000N. The LaMMos - Latching Mechanism based on Motorized- screw has been applied to the DeWaLoP - Developing Water Loss Prevention in-pipe robot. It helps the robot to shrink its body to crawl into the pipe with minimum diameter, by recon- figuring the leg positions. And it helps to recover the legs positions to original status once the robot is inside the pipe. Also, LaMMos add stiffness to the robot legs by dynamically integrate them to the structure. Additionally, we present an application of the LaMMos mechanism to exoskeleton suits, for easing the mo- tors from the joints when carrying heavy weights for long periods of time. This mechanism offers many interesting opportunities for robotics research in terms of functionality, pay- load and size.Comment: 14 pages, 15 figure

    Lessons from the terra preta de índios of the amazon region for the utilisation of charcoal for soil amendment

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    peer-reviewedThe potential of charcoal and of partially combusted organic waste to mimic the soil organic matter of the Terras Pretas de Índios (Amazonian Dark Earths) from the Amazon Region is discussed. These materials serve as soil conditioners and as sequesterers of carbon in recalcitrant and in reactive forms. Studies carried out by Brazilian and by international groups have contributed to the emergence of an awareness of the compositions and of the uses of these materials. In this contribution we report on chemical studies that are leading to the development of a scientific and technological awareness, and of innovations that will have value in finding novel uses in applications to soil of chars from organic wastes such as those from the biofuel industry, and from metallurgical and various coal plant residues
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