7,709 research outputs found

    A Killing Disease Epidemic Among Displaced Sudanese Population Identified as Visceral Leishmaniasis.

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    A fatal disease epidemic affected the Bentiu area in southern Sudan and led to a mass migration of the Nuer tribe searching for treatment. The initially available information revealed a high mortality rate due to a possible occurrence of tuberculosis, malaria, enteric fever or visceral leishmaniasis (VL). Serological screening of 53 of the most severely affected patients in an enzyme-linked immunosorbent assay (ELISA) or an improved direct agglutination test (DAT) revealed positivity for VL. In 39 of those patients, diagnosis was confirmed by identification of Leishmania donovani amastigotes in lymph node or bone-marrow aspirates. In a total of 2714 patients observed, 1195 (44.0%) had clinical symptoms suggesting VL: DAT positive titers (1:3200-greater than or equal to 1:12800) were obtained in 654 (24.1%), of whom 325 were confirmed parasitologically. Forty-two VL cases died before or during treatment, giving a mortality rate of 6.4%. Among the intercurrent infections diagnosed in the VL population (654), respiratory involvements (31.7%) and malaria (10.7%) were most prevalent. With the exception of four (0.6%), all other VL patients (509) responded readily to sodium stibogluconate. The factors initiating the outbreak are discussed. Malnutrition and nomadic movements to potential VL endemic areas appeared to be the most important. HIV infection as a possible predisposition seemed remote considering the clinical and epidemiological similarity to VL occurring in East Africa, adequate humoral response in DAT, and immediate positive response to specific anti-Leishmania chemotherapy

    Sicherheitsbeurteilung von Tragwerken mit Fuzzy-Modellen

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    Die Sicherheit von Tragwerken hängt von der zuverlässigen Modellierung sämtlicher Tragwerksparameter ab. Üblicherweise werden diese Parameter als deterministische oder stochastische Größen beschrieben. Stochastische Größen sind Zufallsgrößen, die unscharfe Informationen über Tragwerksparameter mit Hilfe von Dichtefunktionen erfassen. Nicht alle unscharfen Tragwerksparameter lassen sich als Zufallsgrößen darstellen. Sie können jedoch als Fuzzy-Größen modelliert werden. Fuzzy-Größen beschreiben unscharfe Tragwerksparameter als unscharfe Menge mit Bewertungsfunktion (Zugehörigkeitsfunktion). Die Fuzzy-Modellierung im Bauingenieurwesen umfaßt die Fuzzifizierung, die Fuzzy-Analyse, die Defuzzifizierung und die Sicherheitsbeurteilung. Sie erlaubt es, Tragwerke mit nicht-stochastischen unscharfen Eingangsinformationen zu untersuchen. Nicht-stochastische Eingangsinformationen treten sowohl bei bestehenden als auch bei neuen Tragwerken auf. Die unscharfen Ergebnisse der Fuzzy-Modellierung gestatten es, das Systemverhalten zutreffender zu beurteilen; sie sind die Ausgangspunkte für eine neue Sicherheitsbeurteilung auf der Grundlage der Möglichkeitstheorie. Bei der Fuzzy-Analyse ist die alpha-Diskretisierung vorteilhaft einsetzbar. Bei fehlender Monotonie der deterministischen Berechnungen und unter Berücksichtigung der Nichtlinearität wird die Fuzzy-Analyse mit Optimierungsalgorithmen durchgeführt. Zwei Beispiele werden diskutiert: die Lösung eines transzendenten Eigenwertproblems und eines linearen Gleichungssystems. Die Systemantworten der Fuzzy-Analyse werden der Sicherheitsbeurteilung zugrunde gelegt. Für ausgewählte physikalische Größen werden Versagensfunktionen definiert. Diese bewerten die Möglichkeit des Versagens. Mit Hilfe von Min-max-Operationen der Fuzzy-Set-Theorie erhält man aus Versagensfunktion und Fuzzy-Antwort die Versagensmöglichkeit bzw. die Überlebensmöglichkeit. Die ermittelte Versagensmöglichkeit repräsentiert die subjektive Beurteilung der Möglichkeit, daß das Ereignis &qout;Versagen&qout; eintritt. Beispiele zeigen die Unterschiede zwischen der Sicherheitsbeurteilung mittels Fuzzy-Modells und mittels deterministischen Modells

    Big data and diabetes: the applications of big data for diabetes care now and in the future

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    Aims: Review the current applications of Big Data in diabetes care and consider the future potential. Methods: Scoping study of the academic literature on Big Data and diabetes care. Results: Healthcare data are being produced at ever-increasing rates, and this information has the potential to transform the provision of diabetes care. Big Data is beginning to have an impact on diabetes care through data research. The use of Big Data for routine clinical care is still a future application. Conclusions: Vast amounts of healthcare data are already being produced, and the key is harnessing these to produce actionable insights. Considerable development work is required to achieve these goals

    Stress anisotropy in polymer brushes and its effects on wetting

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    Polymer brushes, coatings consisting of densely grafted macromolecules, have been known to experience an intrinsic lateral compressive stress, originating from chain elasticity and excluded volume interactions. This lateral stress complicates a proper definition of the interface and, thereby, of the interfacial tension. Moreover, its effect on wettability has remained unclear. Here, we study the link between grafting-induced compressive lateral stress in polymer brushes, interfacial tension, and brush wettability using coarse-grained molecular dynamics simulations. A central result is that the liquid contact angle is independent of grafting density, which implies that the strength of the compressive stress inside brush has no influence on the wettability. Interestingly, though the interfacial tensions lack a proper definition, the difference in interfacial tension between wet and dry brushes is perfectly well-defined. We confirm explicitly from Young's law that this difference offers an accurate description of the brush wettability. It is demonstrated how these results can be explained from the fact that the compressive stress appears "symmetrically" in wet and dry brushes. We discuss our findings in the light of autophobic dewetting and point out the connection to the Shuttleworth effect for wetting on elastomers

    Mechanisms of transient nitric oxide and nitrous oxide production in a complex biofilm

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    Nitric oxide (NO) and nitrous oxide (N2O) are formed during N-cycling in complex microbial communities in response to fluctuating molecular oxygen (O2) and nitrite (NO2−) concentrations. Until now, the formation of NO and N2O in microbial communities has been measured with low spatial and temporal resolution, which hampered elucidation of the turnover pathways and their regulation. In this study, we combined microsensor measurements with metabolic modeling to investigate the functional response of a complex biofilm with nitrifying and denitrifying activity to variations in O2 and NO2−. In steady state, NO and N2O formation was detected if ammonium (NH4+) was present under oxic conditions and if NO2− was present under anoxic conditions. Thus, NO and N2O are produced by ammonia-oxidizing bacteria (AOB) under oxic conditions and by heterotrophic denitrifiers under anoxic conditions. NO and N2O formation by AOB occurred at fully oxic conditions if NO2− concentrations were high. Modeling showed that steady-state NO concentrations are controlled by the affinity of NO-consuming processes to NO. Transient accumulation of NO and N2O occurred upon O2 removal from, or NO2− addition to, the medium only if NH4+ was present under oxic conditions or if NO2− was already present under anoxic conditions. This showed that AOB and heterotrophic denitrifiers need to be metabolically active to respond with instantaneous NO and N2O production upon perturbations. Transiently accumulated NO and N2O decreased rapidly after their formation, indicating a direct effect of NO on the metabolism. By fitting model results to measurements, the kinetic relationships in the model were extended with dynamic parameters to predict transient NO release from perturbed ecosystems

    Condensation of microturbulence-generated shear flows into global modes

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    In full flux-surface computer studies of tokamak edge turbulence, a spectrum of shear flows is found to control the turbulence level and not just the conventional (0,0)-mode flows. Flux tube domains too small for the large poloidal scale lengths of the continuous spectrum tend to overestimate the flows, and thus underestimate the transport. It is shown analytically and numerically that under certain conditions dominant (0,0)-mode flows independent of the domain size develop, essentially through Bose-Einstein condensation of the shear flows.Comment: 5 pages, 4 figure
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