35 research outputs found

    Enhanced granular medium-based tube press hardening

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    Active and passive control strategies of internal pressure for hot forming of tubes and profiles with granular media are described. Force transmission and plastic deformation of granular medium is experimentally investigated. Friction between tube, granular medium and die as also the external stress field are shown to be essential for the process understanding. Wrinkling, thinning and insufficient forming of the tube establishes the process window for the active pressure process. By improving the punch geometry and controlling tribological conditions, the process limits are extended. Examples for the passive pressure process reveal new opportunities for hot forming of tubes and profiles.Comment: 4 pages, 11 figure

    Nitrogen deprivation strongly affects Photosystem II but not phycoerythrin level in the divinyl-chlorophyll b-containing cyanobacterium Prochlorococcus marinus

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    AbstractEffects of nitrogen limitation on Photosystem II (PSII) activities and on phycoerythrin were studied in batch cultures of the marine oxyphotobacterium Prochlorococcus marinus. Dramatic decreases in photochemical quantum yields (FV/FM), the amplitude of thermoluminescence (TL) B-band, and the rate of QA reoxidation were observed within 12 h of growth in nitrogen-limited conditions. The decline in FV/FM paralleled changes in the TL B-band amplitude, indicative of losses in PSII activities and formation of non-functional PSII centers. These changes were accompanied by a continuous reduction in D1 protein content. In contrast, nitrogen deprivation did not cause any significant reduction in phycoerythrin content. Our results refute phycoerythrin as a nitrogen storage complex in Prochlorococcus. Regulation of phycoerythrin gene expression in Prochlorococcus is different from that in typical phycobilisome-containing cyanobacteria and eukaryotic algae investigated so far

    Facial expressions depicting compassionate and critical emotions: the development and validation of a new emotional face stimulus set

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    Attachment with altruistic others requires the ability to appropriately process affiliative and kind facial cues. Yet there is no stimulus set available to investigate such processes. Here, we developed a stimulus set depicting compassionate and critical facial expressions, and validated its effectiveness using well-established visual-probe methodology. In Study 1, 62 participants rated photographs of actors displaying compassionate/kind and critical faces on strength of emotion type. This produced a new stimulus set based on N = 31 actors, whose facial expressions were reliably distinguished as compassionate, critical and neutral. In Study 2, 70 participants completed a visual-probe task measuring attentional orientation to critical and compassionate/kind faces. This revealed that participants lower in self-criticism demonstrated enhanced attention to compassionate/kind faces whereas those higher in self-criticism showed no bias. To sum, the new stimulus set produced interpretable findings using visual-probe methodology and is the first to include higher order, complex positive affect displays

    Polygenic overlap between C-reactive protein, plasma lipids, and Alzheimer disease

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    Background—Epidemiological findings suggest a relationship between Alzheimer disease (AD), inflammation, and dyslipidemia, although the nature of this relationship is not well understood. We investigated whether this phenotypic association arises from a shared genetic basis. Methods and Results—Using summary statistics (P values and odds ratios) from genome-wide association studies of >200 000 individuals, we investigated overlap in single-nucleotide polymorphisms associated with clinically diagnosed AD and C-reactive protein (CRP), triglycerides, and high- and low-density lipoprotein levels. We found up to 50-fold enrichment of AD single-nucleotide polymorphisms for different levels of association with C-reactive protein, low-density lipoprotein, high-density lipoprotein, and triglyceride single-nucleotide polymorphisms using a false discovery rate threshold <0.05. By conditioning on polymorphisms associated with the 4 phenotypes, we identified 55 loci associated with increased AD risk. We then conducted a meta-analysis of these 55 variants across 4 independent AD cohorts (total: n=29 054 AD cases and 114 824 healthy controls) and discovered 2 genome-wide significant variants on chromosome 4 (rs13113697; closest gene, HS3ST1; odds ratio=1.07; 95% confidence interval=1.05–1.11; P=2.86×10−8) and chromosome 10 (rs7920721; closest gene, ECHDC3; odds ratio=1.07; 95% confidence interval=1.04–1.11; P=3.38×10−8). We also found that gene expression of HS3ST1 and ECHDC3 was altered in AD brains compared with control brains. Conclusions—We demonstrate genetic overlap between AD, C-reactive protein, and plasma lipids. By conditioning on the genetic association with the cardiovascular phenotypes, we identify novel AD susceptibility loci, including 2 genome-wide significant variants conferring increased risk for AD.acceptedVersio

    Methodologische Untersuchungen zur VerĂ€nderung sahelischer Überschwemmungsgebiete mittels Fernerkundung - Fallbeispiel Nigerbinnendelta (Mali) -

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    ZUSAMMENFASSUNG Langzeitbeobachtungsstudien zur Landschaftsdynamik inSahellĂ€ndern stehen generell einem defizitĂ€ren Angebot anquantitativen Rauminformationen gegenĂŒber. Der in Malivorgefundene lokal- bis regionalrĂ€umliche DatenmangelfĂŒhrte zu einer methodologischen Studie, die die Entwicklungvon Verfahren zur multi-temporalen Erfassung und Analyse vonLandschaftsverĂ€nderungsdaten beinhaltet. FĂŒr den RaumWestafrika existiert in großer FlĂ€chenĂŒberdeckunghistorisches Fernerkundungsmaterial in Form hochauflösenderLuftbilder ab den 50er Jahren und erste erdbeobachtendeSatellitendaten von Landsat-MSS ab den 70er Jahren.Multitemporale Langzeitanalysen verlangen zur digitalenReproduzierbarkeit, zur Datenvergleich- undObjekterfaßbarkeit die a priori-Betrachtung derDatenbeschaffenheit und -qualitĂ€t. Zwei, ohne verfĂŒgbare, noch rekonstruierbareBodenkontrolldaten entwickelte MethodenansĂ€tze zeigen nichtnur die Möglichkeiten, sondern auch die Grenzen eindeutigerradiometrischer und morphometrischerBildinformationsgewinnung. Innerhalb desÜberschwemmungsgunstraums des Nigerbinnendeltas im ZentrumMalis stellen sich zwei Teilstudien zur Extraktion vonquantitativen Sahelvegetationsdaten den radiometrischen undatmosphĂ€rischen Problemen:1. PrĂ€prozessierende Homogenisierung von multitemporalenMSS-Archivdaten mit Simulationen zur WirksamkeitatmosphĂ€rischer und sensorbedingter Effekte2. Entwicklung einer Methode zur semi-automatischenErfassung und Quantifizierung der Dynamik derGehölzbedeckungsdichte auf panchromatischenArchiv-Luftbildern Die erste Teilstudie stellt historischeLandsat-MSS-Satellitenbilddaten fĂŒr multi-temporale Analysender Landschaftsdynamik als unbrauchbar heraus. In derzweiten Teilstudie wird der eigens, mittelsmorphomathematischer Filteroperationen fĂŒr die automatischeMusterkennung und Quantifizierung von Sahelgehölzobjektenentwickelte Methodenansatz prĂ€sentiert. Abschließend wird die Forderung nach kosten- undzeiteffizienten Methodenstandards hinsichtlich ihrerReprĂ€sentativitĂ€t fĂŒr die Langzeitbeobachtung desRessourceninventars semi-arider RĂ€ume sowie deroperationellen Transferierbarkeit auf Datenmaterial modernerFernerkundungssensoren diskutiert.ABSTRACT Long-time monitoring of landscape dynamics in Sahelcountries are confronted to a lack of quantitative spatialinformation in general. This lack of local to regional leveldata has induced to a methodological study, dealing with thedevelopment of methods for acquisition and analysis ofmulti-temporal data to landscape changes. Historical remotesensing data are covering with huge sheets the region ofWestafrica. There are high resolution aerial photographsfrom up to the 50ies so as some first earth observationsatellite data of Landsat MSS from up to the 70ies. Multitemporal long-time monitoring requires respective toditital data reproductivity, data comparability and objectextraction the a-priori consideration of data property andquality. Two methods, developed without available, nor reproduciblesoil control data are showing not only the potential, butalso the limits of radiometric and morphometric informationgain of image data. Within the favoured inonndation area ofthe Internal Niger Delta of central Mali two partial studiesare treating the radiometric and atmospheric problemsrelated to the extraction of quantitative data of Sahelianwood objects : 1. Preprocessing homogenization of multitemporal MSSarchive data with simulations of the impact of atmosphericand sensor-induced effects 2. Development of a method to semi-automatic recognitionand quantification of dynamics of wood cover density onpanchromatic historical aerial photographs The first partial study exposes Landsat MSS historicalsatellite data as unsuitable for multi-temporal analyses oflandscape dynamis. The second partial study presents thedevelopment of a special method to automated wood coverrecognition and quantification by the use ofmorpho-mathematic filter operations. Finally, the postulation of cost- and time efficient methodstandards is discussed in view of a representativity tolong-time monitoring of reource inventories in semi-aridregions, so as of the operational transferability betweenhistorical remote sensing data and such data of modernsensors

    Job satisfaction of primary care physicians in Switzerland: an observational study

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    BACKGROUND: Job satisfaction of physicians is an important issue for performance of a health care system. The aim of the study was to evaluate the job satisfaction of primary care physicians in Switzerland and to explore associations between overall job satisfaction, individual characteristics and satisfaction with aspects of work within the practice separated by gender. METHODS: This cross-sectional study was based on a job satisfaction survey. Data were collected from 176 primary care physicians working in 91 primary care practices. Job satisfaction was measured with the 10-item Warr-Cook-Wall job satisfaction scale. Stepwise linear regression analysis was performed for physicians separated by gender. RESULTS: The response rate was 92.6%. Primary care physicians reported the highest level of satisfaction with 'freedom of working method' (mean = 6.45) and the lowest satisfaction for 'hours of work' (mean = 5.38) and 'income' (mean = 5.49). Moreover, some aspects of job satisfaction were rated higher by female physicians than male physicians. Within the stepwise regression analysis, the aspect 'opportunity to use abilities' (ÎČ = 0.644) showed the highest association to overall job satisfaction for male physicians while for female physicians it was income (ÎČ = 0.733). CONCLUSIONS: The presented results contribute to an understanding of factors that influence levels of satisfaction of female and male physicians. Therefore, research and intervention about job satisfaction should consider gender as well as the stereotypes that come along with these social roles
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