209 research outputs found

    Cytometric analysis, genetic manipulation and antibiotic selection of the snail embryonic cell line Bge from Biomphalaria glabrata, the intermediate host of Schistosoma mansoni.

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    The invertebrate cell line, Bge, from embryos of the snail Biomphalaria glabrata, remains to date the only established cell line from any species of the Phylum Mollusca. Since its establishment in 1976 by Eder Hansen, few studies have focused on profiling its cytometrics, growth characteristics or sensitivity to xenobiotics. Bge cells are reputed to be challenging to propagate and maintain. Therefore, even though this cell line is a noteworthy resource, it has not been studied widely. With growing interest in functional genomics, including genetic transformation, to elucidate molecular aspects of the snail intermediate hosts responsible for transmission of schistosomiasis, and aiming to enhance the convenience of maintenance of this molluscan cell line, we deployed the xCELLigene real time approach to study Bge cells. Doubling times for three isolates of Bge, termed CB, SL and UK, were longer than for mammalian cell lines - longer than 40 h in complete Bge medium supplemented with 7% fetal bovine serum at 25 °C, ranging from ∼42 h to ∼157 h when 40,000 cells were seeded. To assess the potential of the cells for genetic transformation, antibiotic selection was explored. Bge cells were sensitive to the aminonucleoside antibiotic puromycin (from Streptomyces alboniger) from 5 μg/ml to 200 ng/ml, displaying a half maximal inhibitory concentration (IC50) of ∼1.91 μg/ml. Sensitivity to puromycin, and a relatively quick kill time (<48 h in 5 μg/ml) facilitated use of this antibiotic, together with the cognate resistance gene (puromycin N-acetyl-transferase) for selection of Bge cells transformed with the PAC gene (puroR). Bge cells transfected with a plasmid encoding puroR were partially rescued when cultured in the presence of 5 μg/ml of puromycin. These findings pave the way for the development of functional genomic tools applied to the host-parasite interaction during schistosomiasis and neglected tropical trematodiases at large

    Gradients from GOCE reveal gravity changes before Pisagua Mw = 8.2 and Iquique Mw = 7.7 large megathrust earthquakes

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    Considerable improvements in the measurement of the Earth gravity field from GOCE satellite mission have provided global gravity field models with homogeneous coverage, high precision and good spatial resolution. In particular, the vertical gravity gradient (Tzz), in comparison to the classic Bouguer anomaly, defines more accurately superficial mass heterogeneities. Moreover, the correction of these satellitederived data from the effect of Earth topographic masses by means of new techniques taking into account the Earth curvature, improves results in regional analyses. In a recent work we found a correlation between Tzz and slip distribution for the 2010 Maule Mw= 8.8 earthquake. In the present work, we derive the vertical gravity gradient from the last GOCE only model, corrected by the topographic effect and also by the sediments on depocenters of the offshore region at the PerueChile margin, in order to study a spatial relationship between different lobes of the gravity derived signal and the seismic sources of large megathrust earthquakes. In particular, we analyze this relation for the slip models of the 1996 Mw = 7.7 Nazca, 2001 Mw = 8.4 Arequipa, 2007 Mw = 8.0 Pisco events and for the slip models of the 2014 Mw = 8.2 Pisagua and Mw = 7.7 Iquique earthquakes from Schurr et al. (2014), including the previously analyzed 2010 Mw = 8.8 Maule event. Then we find a good correlation between vertical gravity gradients and main rupture zones, correlation that becomes even stronger as the event magnitude increases. Besides this, a gravity fall in the gravity gradient was noticed over the area of the main slip patches at least for the two years before 2014 Mw = 8.2 Pisagua and Mw = 7.7 Iquique earthquakes. Additionally, we found temporal variations of the gravity field after 2010 Mw = 8.8 Maule event, related to the main patches of the slip distribution, and coseismic deformation. Therefore, we analyzed vertical gravity gradient field variations as an indirect measure of the variable seismic coupling finding a potential relationship between Tzz and the seismic b-value. These relationships exemplify the strong potential of the satellite only derived models as a predictive tool to determine potential seismic energy released in a subduction segment, determining the potential size of a potential rupture zone, and in particular internal slip distribution that allows inferring coseismic displacement field at surface

    Estimativa do potencial erosivo das chuvas em municípios no entorno a Flona Tapajós, Amazônia.

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    O objetivo deste trabalho foi estimar o potencial erosivo das chuvas em municípios no entorno da Floresta Nacional do Tapajós, no estado do Pará para avaliar anos com maior ameaça a erosão dos solos. Foram utilizados dados de precipitação pluvial disponibilizados por órgãos de monitoramento meteorológico na região. Para garantir as avaliações de uma série longa de dados fez-se o cálculo do fator (R) considerando-se o maior período (1972 a 2012) em Belterra, período intermediário (1979 a 2009) em Santarém e na série homogênea, entre 1983 a 2002. Os dados evidenciaram que nos três municípios a distribuição anual do potencial erosivo das chuvas tem comportamentos semelhantes, sendo em Rurópolis as maiores flutuações. O ano de 1995 foi o que apresentou maior erosividade das chuvas anuais, no período de maior pluviosidade com 14.328,3 MJ mm ha-1 ano -1 em Santarém, 14.620,2 MJ mm ha-1 ano -1 em Belterra e 15.251,3 MJ mm ha-1 ano -1 em Ruropolis. Chuvas anuais com menores valores foram estimados em 1992, com 5.543,4 MJ mm ha-1ano-1 (Santarém), 5.830,9 MJ mm ha-1 ano-1 (Belterra) e 7.710,5 MJ mm ha-1ano-1 (Ruroplois). Esses dados evidenciam que as áreas cultivadas com grãos ou pastagens mal manejadas mais próximas ao município de Rurópolis são mais vulneráveis à erosão hídrica em relação a Belterra e Santarém. Práticas conservacionais devem ser adotadas para manter a capacidade produtiva dos solos nessa região

    The westward lithospheric drift, its role on the subduction and transform zones surrounding Americas. Andean to cordilleran orogenic types cyclicity

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    We investigate the effect of the westerly rotation of the lithosphere on the active margins that surround the Americas and find good correlations between the inferred easterly-directed mantle counterflow and the main structural grain and kinematics of the Andes and Sandwich arc slabs. In the Andes, the subduction zone is shallow and with low dip, because the mantle flow sustains the slab; the subduction hinge converges relative to the upper plate and generates an uplifting doubly verging orogen. The Sandwich Arc is generated by a westerly-directed SAM (South American) plate subduction where the eastward mantle flow is steepening and retreating the subduction zone. In this context, the slab hinge is retreating relative to the upper plate, generating the backarc basin and a low bathymetry single-verging accretionary prism. In Central America, the Caribbean plate presents a more complex scenario: a) To the East, the Antilles Arc is generated by westerly directed subduction of the SAM plate, where the eastward mantle flow is steepening and retreating the subduction zone. b) To the West, the Middle America Trench and Arc are generated by the easterly-directed subduction of the Cocos plate, where the shallow subduction caused by eastward mantle flow in its northern segment gradually steepens to the southern segment as it is infered by the preexisting westerly-directed subduction of the Caribbean Plateau. In the frame of the westerly lithospheric flow, the subduction of a divergent active ridge plays the role of introducing a change in the oceanic/continental plate's convergence angle, such as in NAM (North American) plate with the collision with the Pacific/Farallon active ridge in the Neogene (Cordilleran orogenic type scenario). The easterly mantle drift sustains strong plate coupling along NAM, showing at Juan de Fuca easterly subducting microplate that the subduction hinge advances relative to the upper plate. This lower/upper plate convergence coupling also applies along strike to the neighbor continental strike slip fault systems where subduction was terminated (San Andreas and Queen Charlotte). The lower/upper plate convergence coupling enables the capture of the continental plate ribbons of Baja California and Yakutat terrane by the Pacific oceanic plate, transporting them along the strike slip fault systems as para-autochthonous terranes. This Cordilleran orogenic type scenario, is also recorded in SAM following the collision with the Aluk/Farallon active ridge in the Paleogene, segmenting SAM margin into the eastwardly subducting Tupac Amaru microplate intercalated between the proto-Liquiñe-Ofqui and Atacama strike slip fault systems, where subduction was terminated and para-autochthonous terranes transported. In the Neogene, the convergence of Nazca plate with respect to SAM reinstalls subduction and the present Andean orogenic type scenario

    Condições agrometeorológicas e fenológicas do cafeeiro arábica nas regiões sul e alto Paranaíba do Estado de Minas Gerais no período de 2002-2004.

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    Neste trabalho é apresentada uma comparação entre os balanços hídricos seqüenciais decendiais dos municípios de Guaxupé e Monte Carmelo, MG, referentes ao período de 20022004. Além disso, é apresentada uma análise das condições agrometeorológicas ocorridas nas diferentes fases de desenvolvimento do cafeeiro arábica durante o período mencionado, em ambos os municípios. Pode-se verificar que o monitoramento agrometeorológico associado às fases fenológicas do cafeeiro arábica é uma ferramenta muito importante que poderá contribuir para a redução dos possíveis prejuízos provenientes de condições meteorológicas adversas, tais como, deficiências hídricas prolongadas e ocorrência de extremos de temperaturas do ar

    Fenologia do cafeeiro: condições agrometeorológicas e balanço hídrico - ano agrícola 2002-2003.

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    Características fenológicas e agrometeorológicas do cafeeiro; Fenoliogia do cafeeiro; Exigências térmicas do cafeeiro; Exigências hídricas; Resenha agrometeorológica do ano agrícola 2002-2003; Monitoramento agrometeorológicas e informações climatológicas médias; Região sul; guaxupé; Região do Triângulo mineiro e Alto Paranaíba; Rio Paranaíba; Monte Carmelo; Estado de São Paulo; Região Mogiana; Campinas; Região Nordeste; Franca; Mococa; Rejgião da Paulista; Marília; Estado do Paraná; Região Norte; Londrina.bitstream/item/32753/1/Fenologia-do-cafeeiro-2002-2003.pd

    Liver biopsy may facilitate pancreatic graft evaluation: Positive association between liver steatosis and pancreatic graft adipose infiltration

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    OBJECTIVES: The number of pancreatic transplants has decreased in recent years. Pancreatic grafts have been underutilized compared to other solid grafts. One cause of discard is the macroscopic appearance of the pancreas, especially the presence of fatty infiltration. The current research is aimed at understanding any graft-related association between fatty tissue infiltration of the pancreas and liver steatosis. METHODS: From August 2013 to August 2014, a prospective cross-sectional clinical study using data from 54 multiple deceased donor organs was performed. RESULTS: Micro- and macroscopic liver steatosis were significantly correlated with the donor body mass index ([BMI]; p=0.029 and p=0.006, respectively). Positive gamma associations between pancreatic and liver macroscopic and microscopic findings (0.98; confidence interval [CI]: 0.95-1 and 0.52; CI 0.04-1, respectively) were observed. Furthermore, comparisons of liver microscopy findings showed significant differences between severe versus absent (

    Pegada hídrica como indicador de sustentabilidade em polo de grãos na Amazônia.

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    O objetivo do trabalho foi avaliar a pegada hídrica das principais cultivares de soja como indicador de eficiência de uso da água em cultivos de grãos no município de Paragominas. Foi realizado trabalho de campo para acompanhar experimentos com soja visando obtenção de dados durante a safra agrícola 2013/2014. Considerou-se nas estimativas de pegada hídrica cinza o valor de 22 kg ha-1 de nitrogênio, com base na literatura nacional. As cultivares de soja BRS Candeia; BRS Sambaíba; BRS Tracajá; BRS Seridó RCH; BRS Babaçu foram consideradas nas avaliações da pegada hídrica de acordo com o ciclo médio, disponível na literatura. Considerou-se os padrões limites de lançamento de fertilizante nitrogenado em corpos hídricos, adotando-se valores conforme a legislação nº 357/2005 do Conselho Nacional de Meio Ambiente (CONAMA). Os resultados apontaram que a maior pegada hídrica foi na BRS Babaçu correspondendo a 1.306 m³ ton-1 e a menor foi na BRS Candeia com 1.015 m³ ton-1. Conclui-se que a pegada hídrica verde é um excelente indicador de eficiência de uso da água pela cultivar de soja utilizada em cada ano safra. Também, a quantidade de fertilizantes nitrogenados e o rendimento das cultivares são fatores determinantes na contabilidade de uso eficiente de água em polos grãos na Amazônia
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