1,389 research outputs found

    Fingernail Cortisol: A Biological Signal of Lifetime Major Depressive Disorder

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    Introduction: Elevated levels of the hypothalamic-pituitary-adrenal axis hormone cortisol are a frequently replicated finding in major depressive disorder (MDD). However, the current state of research is inconclusive as to whether hypercortisolism represents a trait- or state-like biological signal of MDD. The aim of the present study was to investigate, for the first time, whether cortisol in fingernails, a highly accessible tissue, could distinguish currently remitted individuals with MDD from healthy controls. A further aim was to identify potential confounders of nail cortisol. Methods: A total of N = 100 individuals from the general population were recruited. A structured clinical interview was administered, which resulted in two groups: n = 48 with lifetime MDD and n = 52 healthy controls. All participants answered questions on sociodemographic, lifestyle, and psychosocial characteristics. They also grew their nails for 14 days and cut them for the subsequent determination of cortisol. Results: The groups differed in their nail cortisol concentrations, such that the individuals with lifetime MDD had significantly higher concentrations than the healthy controls (p = 0.041). Within the group of individuals with lifetime MDD, the number of experienced episodes was significantly correlated with cortisol (p = 0.011). Income emerged as the only significant confounder of cortisol (p = 0.008). Conclusion: Elevated fingernail cortisol appears to be a biological signal of MDD, even in the absence of a current major depressive episode. Its high accessibility and robustness render it a promising methodology for remote research as well as for the integration of biomarkers into clinical research and practice

    Das Prinzip des rechtsstaatlichen Verwaltungsverfahrens

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    Die Arbeit analysiert zunächst die Judikatur und Literatur zum Themenkomplex "rechtsstaatliches Verwaltungsverfahren" bis Oktober 2006. Auf Grundlage dieser Analyse wird der Beweis erbracht, dass in der österreichischen Rechtsordnung eine ungeschriebene Rechtswegegarantie identifiziert werden kann, die als "Prinzip des rechtsstaatlichen Verwaltungsverfahrens" bezeichnet wird. Dieses Prinzip in seiner Geltung zu beweisen und in seinem Inhalt zu erklären, bildet den Schwerpunkt der Arbeit. Vor dem Hintergrund moderner Rechts- und Kommunikationstheorien wird der Nachweis erbracht, dass das Prinzip des rechtsstaatlichen Verwaltungsverfahrens auf der Ebene des einfachen Verfassungsrechts angesiedelt ist und die Grundsätze der Richtigkeit, Fairness und Effektivität zum Inhalt hat

    Goal Oriented Provision of Design Principles for Additive Manufacturing to Support Conceptual Design

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    Additive Manufacturing (AM) offers a new degree in design freedom. However, in order to exploit AM's potentials in end-use products a methodical approach and suitable tools especially during conceptual design are needed. This paper presents a methodology for application in industrial practice, which should support the component conception for additively manufactured products. The approach focuses on a benefit-oriented preparation and provision of knowledge. In addition to general design methods for abstraction and promotion of creativity, AM-specific tools are introduced which support the provision of solution principles and process-specific restrictions. A broad applicability of the solution principles is ensured by an expansion of the solution space through abstraction. Consequently, product developers are sensitised to the new design possibilities of AM, on the one hand. On the other hand, they are supported in a holistic exploitation of design potentials in ideation in order to foster innovative solution ideas. Finally, the methodological procedure and the developed tools will be demonstrated in a workshop by using an example from industrial practice of the automotive sector

    Combined particle image velocimetry and thermometry of turbulent superstructures in thermal convection

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    Turbulent superstructures in horizontally extended three-dimensional Rayleigh-B\'enard convection flows are investigated in controlled laboratory experiments in water at Prandtl number Pr=7Pr = 7. A Rayleigh-B\'enard cell with square cross-section, aspect ratio Γ=l/h=25\Gamma = l/h = 25, side length ll and height hh is used. Three different Rayleigh numbers in the range 105<Ra<10610^5 < Ra < 10^6 are considered. The cell is accessible optically, such that thermochromic liquid crystals can be seeded as tracer particles to monitor simultaneously temperature and velocity fields in a large section of the horizontal mid-plane for long time periods of up to 6 h, corresponding to approximately 10410^4 convective free-fall time units. The joint application of stereoscopic particle image velocimetry and thermometry opens the possibility to assess the local convective heat flux fields in the bulk of the convection cell and thus to analyse the characteristic large-scale transport patterns in the flow. A direct comparison with existing direct numerical simulation data in the same parameter range of Pr,RaPr, Ra and Γ\Gamma reveals the same superstructure patterns and global turbulent heat transfer scaling Nu(Ra)Nu(Ra). Slight quantitative differences can be traced back to violations of the isothermal boundary condition at the extended water-cooled glass plate at the top. The characteristic scales of the patterns fall into the same size range, but are systematically larger. It is confirmed experimentally that the superstructure patterns are an important backbone of the heat transfer. The present experiments enable, furthermore, the study of the gradual evolution of the large-scale patterns in time, which is challenging in simulations of large-aspect-ratio turbulent convection.Comment: 25 pages, 11 figure

    Expensive multi-objective optimization of electromagnetic mixing in a liquid metal

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    This paper presents a novel trust-region method for the optimization of multiple expensive functions. We apply this method to a biobjective optimization problem in fluid mechanics, the optimal mixing of particles in a flow in a closed container. The three-dimensional time-dependent flows are driven by Lorentz forces that are generated by an oscillating permanent magnet located underneath the rectangular vessel. The rectangular magnet provides a spatially non-uniform magnetic field that is known analytically. The magnet oscillation creates a steady mean flow (steady streaming) similar to those observed from oscillating rigid bodies. In the optimization problem, randomly distributed mass-less particles are advected by the flow to achieve a homogeneous distribution (objective function 1) while keeping the work done to move the permanent magnet minimal (objective function 2). A single evaluation of these two objective functions may take more than two hours. For that reason, to save computational time, the proposed method uses interpolation models on trust-regions for finding descent directions. We show that, even for our significantly simplified model problem, the mixing patterns vary significantly with the control parameters, which justifies the use of improved optimization techniques and their further development
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