1,505 research outputs found

    Dem Jubilar Prof. (em.) Dr. Rudolf Hohl

    Get PDF
    Das Hallesche Jahrbuch ist in Mitteldeutschland das Journal für die Geowissenschaften. Es ist mit einem Band pro Jahr und diversen Beiheften ideal für die Publikation lokaler und überregionaler Beiträge und zugleich ein ideales Medium, um Promotionen und hochqualifizierte Abschlussarbeiten der Öffentlichkeit zugänglich zu machen. So ist das Hallesche Jahrbuch durch sein regelmäßiges Erscheinen und eine zügige Bearbeitung die ideale Plattform für Ihre Publikationen. Solche können in deutscher oder englischer Sprache angenommen werden

    Association of exposure to manganese and iron with relaxation rates R1 and R2*- magnetic resonance imaging results from the WELDOX II study

    Get PDF
    Objective Magnetic resonance imaging is a non-invasive method that allows the indirect quantification of manganese (Mn) and iron (Fe) accumulation in the brain due to their paramagnetic features. The WELDOX II study aimed to explore the influence of airborne and systemic exposure to Mn and Fe on the brain deposition using the relaxation rates R1 and R2* as biomarkers of metal accumulation in regions of interest in 161 men, including active and former welders. Material and methods We obtained data on the relaxation rates R1 and R2* in regions that included structures within the globus pallidus (GP), substantia nigra (SN), and white matter of the frontal lobe (FL) of both hemispheres, as well as Mn in whole blood (MnB), and serum ferritin (SF). The study subjects, all male, included 48 active and 20 former welders, 41 patients with Parkinson's disease (PD), 13 patients with hemochromatosis (HC), and 39 controls. Respirable Mn and Fe were measured during a working shift for welders. Mixed regression models were applied to estimate the effects of MnB and SF on R1 and R2*. Furthermore, we estimated the influence of airborne Mn and Fe on the relaxation rates in active welders. Results MnB and SF were significant predictors of R1 but not of R2* in the GP, and were marginally associated with R1 in the SN (SF) and FL (MnB). Being a welder or suffering from PD or HC elicited no additional group effect on R1 or R2* beyond the effects of MnB and SF. In active welders, shift concentrations of respirable Mn > 100 μg/m3 were associated with stronger R1 signals in the GP. In addition to the effects of MnB and SF, the welding technique had no further influence on R1. Conclusions MnB and SF were significant predictors of R1 but not of R2*, indicative of metal accumulation, especially in the GP. Also, high airborne Mn concentration was associated with higher R1 signals in this brain region. The negative results obtained for being a welder or for the techniques with higher exposure to ultrafine particles when the blood-borne concentration was included into the models indicate that airborne exposure to Mn may act mainly through MnB

    Association of exposure to manganese and iron with striatal and thalamic GABA and other neurometabolites - Neuroimaging results from the WELDOX II study

    Get PDF
    OBJECTIVE: Magnetic resonance spectroscopy (MRS) is a non-invasive method to quantify neurometabolite concentrations in the brain. Within the framework of the WELDOX II study, we investigated the association of exposure to manganese (Mn) and iron (Fe) with γ-aminobutyric acid (GABA) and other neurometabolites in the striatum and thalamus of 154 men. MATERIAL AND METHODS: GABA-edited and short echo-time MRS at 3T was used to assess brain levels of GABA, glutamate, total creatine (tCr) and other neurometabolites. Volumes of interest (VOIs) were placed into the striatum and thalamus of both hemispheres of 47 active welders, 20 former welders, 36 men with Parkinson's disease (PD), 12 men with hemochromatosis (HC), and 39 male controls. Linear mixed models were used to estimate the influence of Mn and Fe exposure on neurometabolites while simultaneously adjusting for cerebrospinal fluid (CSF) content, age and other factors. Exposure to Mn and Fe was assessed by study group, blood concentrations, relaxation rates R1 and R2* in the globus pallidus (GP), and airborne exposure (active welders only). RESULTS: The median shift exposure to respirable Mn and Fe in active welders was 23μg/m3 and 110μg/m3, respectively. Airborne exposure was not associated with any other neurometabolite concentration. Mn in blood and serum ferritin were highest in active and former welders. GABA concentrations were not associated with any measure of exposure to Mn or Fe. In comparison to controls, tCr in these VOIs was lower in welders and patients with PD or HC. Serum concentrations of ferritin and Fe were associated with N-acetylaspartate, but in opposed directions. Higher R1 values in the GP correlated with lower neurometabolite concentrations, in particular tCr (exp(β)=0.87, p<0.01) and choline (exp(β)=0.84, p=0.04). R2* was positively associated with glutamate-glutamine and negatively with myo-inositol. CONCLUSIONS: Our results do not provide evidence that striatal and thalamic GABA differ between Mn-exposed workers, PD or HC patients, and controls. This may be due to the low exposure levels of the Mn-exposed workers and the challenges to detect small changes in GABA. Whereas Mn in blood was not associated with any neurometabolite content in these VOIs, a higher metal accumulation in the GP assessed with R1 correlated with generally lower neurometabolite concentrations

    A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

    Get PDF
    In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio

    Kompass für agrarökonomische Zeitschriften: das GEWISOLA-ÖGA-Publikationsranking

    Get PDF
    Dieser Artikel ist nur in deutscher Sprache verfügbar. The article is only available in German language

    Optics and Quantum Electronics

    Get PDF
    Contains table of contents on Section 3 and reports on nineteen research projects.Defense Advanced Research Projects Agency Grant F49620-96-0126Joint Services Electronics Program Grant DAAH04-95-1-0038National Science Foundation Grant ECS 94-23737U.S. Air Force - Office of Scientific Research Contract F49620-95-1-0221U.S. Navy - Office of Naval Research Grant N00014-95-1-0715Defense Advanced Research Projects Agency/National Center for Integrated Photonics TechnologyMultidisciplinary Research InitiativeU.S. Air Force - Office of Scientific ResearchNational Science Foundation/MRSECU.S. Navy - Office of Naval Research (MFEL) Contract N00014-91-J-1956National Institutes of Health Grant R01-EY11289U.S. Navy - Office of Naval Research (MFEL) Contract N00014-94-0717Defense Advanced Research Projects Agency Contract N66001-96-C-863

    Wissenschaftsforschung Jahrbuch 1996/97

    Get PDF
    Seit längerer Zeit werden Konzepte entworfen, Instrumentarien entwickelt und Maßnahmen ergriffen, deren Ziel es ist, die Strukturen einer Wissenschaftslandschaft zu gestalten, in denen die Gewinnung wissenschaftlicher Erkenntnisse in universitären und außeruniversitärer Forschungsstätten mit der materiellen Potenz und Tatkraft innovativer Wirtschaft zusammengeführt werden kann. Untersuchungen über diesen grundlegenden Vorgang neuerer Wissenschaftsentwicklung sind ein wichtiges Anliegen von Wissenschaftsforschung. Die Gesellschaft für Wissenschaftsforschung hat sich dieser Fragestellungen angenommen und sie im Rahmen ihrer Jahrestagungen 1996 und 1997 unter dem Thema „Wissenschaft – Innovation – Unternehmertum“ analysiert und diskutiert. Dabei ist es gelungen, theoretische überlegungen mit historischen und aktuellen Fakten zu verbinden. Die Ergebnisse werden hiermit – in Fortführung der Publikationsreihe – als Jahrbuch 1996/97 der Gesellschaft für Wissenschaftsforschung dem interessierten Leser vorgestellt.Peer Reviewe

    Applying the effort-reward imbalance model to household and family work: a population-based study of German mothers

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>This paper reports on results of a newly developed questionnaire for the assessment of effort-reward imbalance (ERI) in unpaid household and family work. Methods: Using a cross-sectional population-based survey of German mothers (n = 3129) the dimensional structure of the theoretical ERI model was validated by means of Confirmatory Factor Analysis (CFA). Analyses of Variance were computed to examine relationships between ERI and social factors and health outcomes.</p> <p>Results</p> <p>CFA revealed good psychometric properties indicating that the subscale 'effort' is based on one latent factor and the subscale 'reward' is composed of four dimensions: 'intrinsic value of family and household work', 'societal esteem', 'recognition from the partner', and 'affection from the child(ren)'. About 19.3% of mothers perceived lack of reciprocity and 23.8% showed high rates of overcommitment in terms of inability to withdraw from household and family obligations. Socially disadvantaged mothers were at higher risk of ERI, in particular with respect to the perception of low societal esteem. Gender inequality in the division of household and family work and work-family conflict accounted most for ERI in household and family work. Analogous to ERI in paid work we could demonstrate that ERI affects self-rated health, somatic complaints, mental health and, to some extent, hypertension.</p> <p>Conclusions</p> <p>The newly developed questionnaire demonstrates satisfied validity and promising results for extending the ERI model to household and family work.</p

    Climate change and possible challenges for crop protection – Yesterday, today, tomorrow

    Get PDF
    Das Klima und die Witterung sind prägende Faktoren für den Pflanzenschutz. Bereits vor 100 Jahren haben sich Wissenschaftler im Nachrichtenblatt für den Deutschen Pflanzenschutzdienst dieser Thematik gewidmet. Die Auswirkungen des Klimawandels sind ambivalent und es wird insgesamt zu einer Veränderung des Schaderregerspektrums kommen. Tendenziell werden Schäden durch Insekten, Krankheitserreger und wärmetolerante Unkräu­ter begünstigt. Das Risiko der Etablierung invasiver Arten nimmt zu. Ebenso kann die Wirksamkeit des biologischen Pflanzenschutzes beeinträchtigt und neue Verfahren erforderlich werden. Beim chemischen Pflanzenschutz wird sich das Wirkstoffspektrum verschieben und die Anforderungen an Applikationstechnik und -termin steigen. Starkregen kann das Risiko des Austrags von Pflanzenschutzmitteln in die Umwelt steigern. Auch in Mitteleuropa kann es verstärkt zu Befall mit Vorratsschädlingen bereits im Feld kommen und die Qualität und Lagerstabilität der Ernteprodukte abnehmen. Ins­gesamt wird die Bedeutung präventiver Pflanzenschutzmaßnahmen zunehmen. Die Folgen des Klimawandels erhöhen die betriebs- und volkswirtschaftlichen Risiken und stellen alle Akteursebenen vor erhebliche Heraus­forderungen.Climate and weather are decisive factors for plant protection. Already 100 years ago, scientists dedicated themselves to this topic in the newsletter of the German Plant Protection Service. The effects of climate change are ambi­valent and there will be an overall change in the pest spectrum. Damage caused by insects, pathogens and heat-tolerant weeds will tend to be favoured. The risk of invasive species becoming established increases. Simi­larly, the effectiveness of biological crop protection may be compromised and new methods may be required. In the case of chemical pesticides, the spectrum of active substances will shift and the demands on application technology and timing will increase. Heavy rains can increase the risk of pesticide run-off into the environment. There may be increased infestation with storage pests already in the field in Central Europe too, and the quality and storage stability of harvested products may decline. Overall, the importance of preventive plant protection measures will increase. The consequences of climate change increase operational and economic risks and pose considerable challenges for all levels of stakeholders
    corecore