868 resultados para Ast-8782


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The Dry Valleys of Antarctica are one of the coldest and driest environments on Earth with paleosols in selected areas that date to the emplacement of tills by warm-based ice during the Early Miocene. Cited as an analogue to the martian surface, the ability of the Antarctic environment to support microbial life-forms is a matter of special interest, particularly with the upcoming NASA/ESA 2018 ExoMars mission. Lipid biomarkers were extracted and analyzed by gas chromatography-mass spectrometry to assess sources of organic carbon and evaluate the contribution of microbial species to the organic matter of the paleosols. Paleosol samples from the ice-free Dry Valleys were also subsampled and cultivated in a growth medium from which DNA was extracted with the explicit purpose of the positive identification of bacteria. Several species of bacteria were grown in solution and the genus identified. A similar match of the data to sequenced DNA showed that Alphaproteobacteria, Gamma-proteobacteria, Bacteriodetes, and Actinobacteridae species were cultivated. The results confirm the presence of bacteria within some paleosols, but no assumptions have been made with regard to in situ activity at present. These results underscore the need not only to further investigate Dry Valley cryosols but also to develop reconnaissance strategies to determine whether such likely Earth-like environments on the Red Planet also contain life.

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We prospectively measured serum alkaline phosphatase (ALP), aspartate and alanine transaminase (AST/ALT), and tested sera for antinuclear, smooth-muscle, and antimitochondrial antibodies (ANA, SMA, AMA) in our patients with celiac sprue to determine the prevalence of associated liver abnormalities and its relevance to clinical management. Of 129 patients, ALP was the only elevated enzyme in 12 (9%) and in most cases was not thought to reflect significant liver disease. Seventeen (13%) had elevated AST and/or ALT with normal ALP. Levels normalized in 15 patients after dietary gluten exclusion and remained elevated in 2 noncompliers. Two patients (2%) with elevated AST, ALT, and ALP underwent further investigation: one had negative autoantibodies, liver biopsy, and endoscopic retrograde cholangiography and the other had ANA-positive chronic active hepatitis; enzymes in both cases improved with a gluten-free diet. There was no significant association between elevated AST/ALT and positive ANA/SMA; no patient had AMA. Abnormalities in liver enzymes are common in celiac sprue, but usually respond to dietary gluten exclusion. We propose that there is no need for invasive liver investigation in these patients unless there is more specific evidence of primary liver disease or failure of dietary response.

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Aims. To examine the antioxidant and anti-inflammatory effects of pomegranate polyphenols in obese patients with type 2 diabetes (T2DM) (n = 8) and in healthy nondiabetic controls (n = 9). Methods. Participants received 2 capsules of pomegranate polyphenols (POMx, 1 capsule = 753?mg polyphenols) daily for 4 weeks. Blood draws and anthropometrics were performed at baseline and at 4 weeks of the study. Results. Pomegranate polyphenols in healthy controls and in T2DM patients did not significantly affect body weight and blood pressure, glucose and lipids. Among clinical safety profiles, serum electrolytes, renal function tests, and hematological profiles were not significantly affected by POMx supplementation. However, aspartate aminotransferase (AST) showed a significant increase in healthy controls, while alanine aminotransferase (ALT) was significantly decreased in T2DM patients at 4 weeks (P <0.05), though values remained within the normal ranges. Among the biomarkers of lipid oxidation and inflammation, oxidized LDL and serum C-reactive protein (CRP) did not differ at 4 weeks in either group, while pomegranate polyphenols significantly decreased malondialdehyde (MDA) and hydroxynonenal (HNE) only in the diabetic group versus baseline (P <0.05). Conclusions. POMx reduces lipid peroxidation in patients with T2DM, but with no effects in healthy controls, and specifically modulates liver enzymes in diabetic and nondiabetic subjects. Larger clinical trials are merited.

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A Design of Experiments (DoE) analysis was undertaken to generate a list of configurations for CFD numerical simulation of an aircraft crown compartment. Fitted regression models were built to predict the convective heat transfer coefficients of thermally sensitive dissipating elements located inside this compartment. These are namely the SEPDC and the Route G. Currently they are positioned close to the fuselage and it is of interest to optimise the heat transfer for reliability and performance purposes. Their locations and the external fuselage surface temperature were selected as input variables for the DoE. The models fit the CFD data with values ranging from 0.878 to 0.978, and predict that the optimum locations in terms of heat transfer are when the elements are positioned as close to the crown floor as possible ( and ?min. limits), where they come in direct contact with the air flow from the cabin ventilation system, and when they are positioned close to the centreline ( and ?CL). The methodology employed allows aircraft thermal designers to optimise equipment placement in confined areas of an aircraft during the design phase. The determined models should be incorporated into global aircraft numerical models to improve accuracy and reduce model size and computational time. © 2012 Elsevier Masson SAS. All rights reserved.

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The plug nozzle is one of the advanced expansion devices proposed to improve the overall performance of launcher liquid rocket engines. The present work investigates the three-dimensional flow field generated on this kind of nozzle by partitioning the primary nozzle into modules. A linear plug nozzle has been designed together with modules having two different geometries: a rectangular cross section and round-to-square module. Numerical simulations have been carried out considering the case where all modules of the primary nozzle are active and the case where one module is turned off. The solutions are compared and specific three-dimensional flow structures taking place inside the modules and on the plug are identified. The relationship between these structures and the skin friction distribution within the module and along the plug surface is investigated. Finally, the effect on performance of these three-dimensional flow features is emphasized. © 2006 Elsevier Masson SAS. All rights reserved.

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A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where terrestrial organisms might replicate (per the COSPAR Planetary Protection Policy). This review and update was conducted by an international team (SR-SAG2) drawn from both the biological science and Mars exploration communities, focused on understanding when and where Special Regions could occur. The study applied recently available data about martian environments and about terrestrial organisms, building on a previous analysis of Mars Special Regions (2006) undertaken by a similar team. Since then, a new body of highly relevant information has been generated from the Mars Reconnaissance Orbiter (launched in 2005) and Phoenix (2007) and data from Mars Express and the twin Mars Exploration Rovers (all 2003). Results have also been gleaned from the Mars Science Laboratory (launched in 2011). In addition to Mars data, there is a considerable body of new data regarding the known environmental limits to life on Earth—including the potential for terrestrial microbial life to survive and replicate under martian environmental conditions. The SR-SAG2 analysis has included an examination of new Mars models relevant to natural environmental variation in water activity and temperature; a review and reconsideration of the current parameters used to define Special Regions; and updated maps and descriptions of the martian environments recommended for treatment as “Uncertain” or “Special” as natural features or those potentially formed by the influence of future landed spacecraft. Significant changes in our knowledge of the capabilities of terrestrial organisms and the existence of possibly habitable martian environments have led to a new appreciation of where Mars Special Regions may be identified and protected. The SR-SAG also considered the impact of Special Regions on potential future human missions to Mars, both as locations of potential resources and as places that should not be inadvertently contaminated by human activity. Key Words: Martian environments—Mars astrobiology—Extreme environment microbiology—Planetary protection—Exploration resources. Astrobiology 14, 887–968.

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This letter proposes several relay selection policies for secure communication in cognitive decode-and-forward (DF) relay networks, where a pair of cognitive relays are opportunistically selected for security protection against eavesdropping. The first relay transmits the secrecy information to the destination,
and the second relay, as a friendly jammer, transmits the jamming signal to confound the eavesdropper. We present new exact closed-form expressions for the secrecy outage probability. Our analysis and simulation results strongly support our conclusion that the proposed relay selection policies can enhance the performance of secure cognitive radio. We also confirm that the error floor phenomenon is created in the absence of jamming.

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The objective was to identify determinants of uptake and maintenance of active school travel (AST) over 4 years in children aged 9 at baseline. Data from wave 1 (n=8502) and 2 (n=7479) of the Growing Up in Ireland study were analysed. At 9- and 13-years 25% and 20% engaged in AST. Children were more likely to maintain or take-up AST if they lived in an urban area. Change in distance to school influenced both maintenance and adoption of AST, with a negative impact seen for increased distance between 9 and 13 years and a positive impact seen for decreased distance. Some factors which predict uptake and maintenance of AST are modifiable and can inform intervention development.

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As alterações climáticas emergentes têm um grande impacto no crescimento e desenvolvimento de espécies florestais, nomeadamente em espécies de valor industrial e medicinal, como é o caso do eucalipto (Eucalyptus globulus) e da moringa (Moringa oleifera). Assim, é urgente conhecer as respostas fisiológicas e entender as variações que ocorrem nos perfis metabólicos de espécies vegetais. Neste trabalho, plantas jovens de Eucalyptus globulus foram expostas a radiação UVB (12kJ/m2) e foram avaliadas as respostas fisiológicas e o perfil metabólico, um e onze dias após a aplicação da radiação. A dose de UVB usada não afetou as reações fotoquímicas nem as trocas gasosas, contudo ao nível do metabolismo do carbono (AST e amido) e do conteúdo de pigmentos verificaram-se pequenas alterações (AST e pigmentos). Através da análise do perfil metabólico de E. globulus foram encontrados compostos voláteis e semi-voláteis pertencentes às famílias dos terpenos, sesquiterpenos e aldeídos. Em geral, os sesquiterpenos e os álcoois monoterpénicos apresentaram uma tendência para manter e, em alguns casos, diminuir com o stress, enquanto que o grupos dos aldeídos aumentou e os monoterpenos apresentaram um comportamento mais heterogéneo. O E. globulus mostrou ser uma espécie tolerante à aplicação da dose de UVB usada neste trabalho. Por outro lado, plantas jovens de M. oleifera foram expostas a défice hídrico (DH). Um grupo de plantas foi recolhido um dia após o final da exposição e o outro grupo após onze dias do final da exposição. Foi avaliado o perfil metabólico desta espécie através de GC/MS. Os dados cromatográficos indicaram que em condições de stress (DH(1) e DH(11)), as quantidades de compostos associados a vias primárias e secundárias de defesa (como os alcanos, álcoois, ácidos carboxílicos, esteróis, aminoácidos e açucares) sofreram algumas alterações. As plantas analisadas 11 dias após a remoção do stress mostraram maiores variações do perfil de metabolitos. No entanto, tanto um como onze dias após a remoção do stress, as plantas apresentaram a formação de novos rebentos. Apesar do perfil de metabolitos ter sofrido algumas alterações, por não se registarem casos de morte, conclui-se que as plantas de moringa mostraram ser tolerantes aos tratamentos aplicados.

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Os ácidos gordos desempenham um papel fisiológico importante como componentes indispensáveis na estrutura celular, bem como fontes de energia. Nas últimas décadas, tem havido um aumento notável do interesse público nos ácidos gordos polinsaturados ómegas 3 e 6 e no seu impacto sobre a saúde humana, especialmente em doenças metabólicas e cardiovasculares. Estes ácidos gordos específicos podem prevenir e/ou tratar várias patologias metabólicas, atuando nomeadamente como compostos anti-inflamatórios. A menopausa é um fator de risco para doença cardiovascular, a diminuição de estrogénio, que ocorre neste estado fisiológico, provoca disfunção endotelial e stresse oxidativo. Consequentemente há uma redução dos níveis de ácidos gordos polinsaturados ómegas 3, o que contribui para o aparecimento de aterosclerose e doença cardiovascular. Neste contexto, o objetivo deste estudo foi avaliar e caracterizar o perfil lipídico de ácidos gordos de uma amostra de mulheres pós-menopausa e com este, estudar as associações entre o perfil lipídico determinado e parâmetros metabólicos de risco (parâmetros clínicos e bioquímicos). Inicialmente, os ácidos gordos foram extraídos da matriz plasmática através da derivatização destes e a sua composição percentual no plasma foi determinada com recurso a cromatografia gasosa com deteção de ionização de chama. De seguida, através do software IBM SPSS Statistics 21, foram estabelecidas associações entre os parâmetros clínicos e bioquímicos e o perfil lipídico determinado. A população em estudo foi divida em dois grupos consoante o período de entrada na menopausa (há menos de 7 anos e há 7 anos ou mais). Não há conhecimento de estudos semelhantes ao apresentado, que relacionem todo o perfil de ácidos gordos com parâmetros metabólicos de risco considerando o estado menopausal. Os resultados obtidos mostram que o perfil lipídico influencia vários marcadores metabólicos / endócrinos com relevância clínica que devem ser explorados em futuros ensaios clínicos. Para as mulheres na menopausa há menos de 7 anos foram estabelecidas as seguintes relações: i) entre os ácidos gordos saturados e insaturados cis e os níveis de ALP; ii) entre os ácidos gordos mono e polinsaturados cis e os níveis de GGT, IL10 e estradiol; iii) entre os ácidos gordos polinsaturados trans e o IMC e os níveis de IL6; iv) entre os ómegas 3 e os níveis de IL10 e ácido úrico; v) entre os ómegas 6 e os níveis de estradiol, ALP e GGT; vi) entre os ómegas 9 e os níveis de estradiol e GGT; vi) entre os ácidos gordos de curta cadeia e os níveis de colesterol total, LDL, triglicerídeos e IL10; vii) entre os ácidos gordos saturados de cadeia longa e o ΣÁcido láurico, mirístico, palmítico e esteárico e os níveis de triglicerídeos, ALP e GGT; viii) os níveis de IL10 podem ser simultaneamente associados com os ácidos gordos de curta cadeia e os ómegas 3. Para as mulheres na menopausa há 7 anos ou mais foram estabelecidas relações: i) entre os ómegas 3 e o IMC e os níveis de triglicerídeos; ii) entre os ácidos gordos monoinsaturados cis e os ómegas 9 com os níveis de ALT. Relações independentes do estado menopausal também foram estabelecidas, nomeadamente: i) entre os ácidos gordos polinsaturados cis e ómegas 6 e os níveis de ALT, triglicerídeos e AST; ii) entre os níveis de ácidos gordos monoinsaturados cis e ómegas 9 e os níveis de AST e triglicerídeos. O perfil lipídico de ácidos gordos pode ser considerado um biomarcador para a condição de saúde da mulher na menopausa.

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The straightforward anatomical organisation of the developing and mature rat spinal cord was used to determine and interpret the time of appearance and expression patterns of microtubule-associated proteins (MAP) 1b and 2. Immunoblots revealed the presence of MAP1b and 2 in the early embryonic rat spinal cord and confirmed the specificity of the used anti-MAP mouse monoclonal antibodies. The immunocytochemical data demonstrated a rostral-to-caudal and ventral-to-dorsal gradient in the expression of MAP1b/2 within the developing spinal cord. In the matrix layer, MAP1b was found in a distinct radial pattern distributed between the membrana limitans interna and externa between embryonal day (E)12 and E15. Immunostaining for vimentin revealed that this MAP1b pattern was morphologically and topographically different from the radial glial pattern which was present in the matrix layer between E13 and E19. The ventral-to-dorsal developmental gradient of the MAP1b staining in the spinal cord matrix layer indicates a close involvement of MAP1b either in the organisation of the microtubules in the cytoplasmatic extensions of the proliferating neuroblasts or neuroblast mitosis. MAP2 could not be detected in the developing matrix layer. In the mantle and marginal layer, MAP1b was abundantly present between E12 and postnatal day (P)0. After birth, the staining intensity for MAP1b gradually decreased in both layers towards a faint appearance at maturity. The distribution patterns suggest an involvement of MAP1b in the maturation of the motor neurons, the contralaterally and ipsilaterally projecting axons and the ascending and descending long axons of the rat spinal cord. MAP2 was present in the spinal cord grey matter between E12 and maturity, which reflects a role for MAP2 in the development as well as in the maintenance of microtubules. The present description of the expression patterns of MAP1b and 2 in the developing spinal cord suggests important roles of the two proteins in various morphogenetic events. The findings may serve as the basis for future studies on the function of MAP1b and 2 in the development of the central nervous system.

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0-meridiaani : Helsinki

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1908/06/30 (Numéro 8782).

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Contient : « Ci commencent les rebriches des establissemens le roy de France, selonc l'usage de Paris et d'Orliens et de court de baronnie » ; « En l'an de grace M.CC.LXX. li bons rois Loeys fist et ordena ces establissemenz... » ; « ... nostre sires li rois deffent les armes et les chevauchiées en ses establissemenz. — Ci fenissent les establissemenz le roy de France, selone l'usage de Paris et d'Orliens et de cort de baronnie. Si a .II.C. et treze chapistres »