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Using Web services, the authors have been able to increase the amount of data accessible through the Naval Research Laboratory’s Geospatial Information Database (GIDB) portal. They created a Web crawler for Web Mapping Services (WMS) that harvests and adds data to the portal index and a translator that provides access to non-WMS data through the WMS interface. The Integrated Web Services Broker, using traditional Web services standards, provides automated access to meteorological and oceanographic data.  相似文献   
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The metabolic ratios lactate/pyruvate and β-hydroxybutyrate/acetoacetate are considered valuable tools to evaluate the in vivo redox cellular state by estimating the free NAD+/NADH in cytoplasm and mitochondria, respectively. The aim of the current study was to validate a gas-chromatography mass spectrometry method for simultaneous determination of the four metabolites in plasma and liver tissue. The procedure included an o-phenylenediamine microwave-assisted derivatization, followed by liquid-liquid extraction with ethyl acetate and silylation with bis(trimethylsilyl)trifluoroacetamide:trimethylchlorosilane 99:1. The calibration curves presented acceptable linearity, with a limit of quantification of 0.001 mM for pyruvate, β-hydroxybutyrate and acetoacetate and of 0.01 mM for lactate. The intra-day and inter-day accuracy and precision were within the European Medicines Agency’s Guideline specifications. No significant differences were observed in the slope coefficient of three-point standard metabolite-spiked curves in plasma or liver and water, and acceptable recoveries were obtained in the metabolite-spiked samples. Applicability of the method was tested in precision-cut liver rat slices and also in HepG2 cells incubated under different experimental conditions challenging the redox state. In conclusion, the validated method presented good sensitivity, specificity and reproducibility in the quantification of lactate/pyruvate and β-hydroxybutyrate/acetate metabolites and may be useful in the evaluation of in vivo redox states.  相似文献   
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All standard methods of hernia repair involve suturing together tissues which are not normally in apposition. This violates the basic surgical principle that tissue must never be approximated under tension and accounts for an unacceptable number of failures. Total reinforcement of the inguinal floor with a sheet of suitable biomaterial and employment of a "tension-free" technique is a more effective approach. Since June 1984, 3250 primary inguinal hernias have been repaired at the Lichtenstein Hernia Institute by the open tension-free technique using Marlex mesh. All operations were performed under local anesthesia. Patients were discharged from the hospital within two or four hours after the operation. The patients were followed from one to 8 years by physician examination. The follow-up rate was 87%. There were four recurrences. The causes of recurrence and how to avoid them are discussed.  相似文献   
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This paper presents a simple model of an AI (artificial intelligence) arms race, where several development teams race to build the first AI. Under the assumption that the first AI will be very powerful and transformative, each team is incentivised to finish first—by skimping on safety precautions if need be. This paper presents the Nash equilibrium of this process, where each team takes the correct amount of safety precautions in the arms race. Having extra development teams and extra enmity between teams can increase the danger of an AI disaster, especially if risk-taking is more important than skill in developing the AI. Surprisingly, information also increases the risks: the more teams know about each others’ capabilities (and about their own), the more the danger increases. Should these results persist in more realistic models and analysis, it points the way to methods of increasing the chance of the safe development of AI.  相似文献   
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This research explores the relationship between campus political norms and student political participation. This study conceptualizes norms as a group‐level construct by collecting data at several universities (k = 32 universities, n = 1,389 students) where norms vary without campaign intervention. Multilevel modeling reveals that perceptions of political norms converge within universities. Further, frequency of political communication at the group‐ and individual‐level explains increases in normative perceptions. This increase is meaningful because norms at the group level were predictive of political behaviors at the individual level. This research documents the existence of political norms beyond the individual level of analysis and highlights the important role of political norms, political communication, and social context in understanding political participation.  相似文献   
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