509 research outputs found

    Retrotransposons and germ cells: reproduction, death, and diversity

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    The evolutionary success of retrotransposable elements is reflected by their abundance in mammalian genomes. To restrict their further advance, a number of defence mechanisms have been put in place by the host. These seem to be particularly effective in the germ line while somatic lineages might be more permissive to new insertions, as recent work by Kano and colleagues suggests

    Permanent Hydrothermal Exposure on Load-bearing Adhesives in Glass Constructions

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    The German research team FABIG develops a bioenergy building skin including modules of glass which contain a liquid medium processing biomass. Inside the facade modules, load-bearing adhesives were applied that are subject to permanent water exposure. Water is known as a major hazard for adhesives because water molecules diffuse into the adhesive polymer matrix and into the interface between adhesive and substrate. As a result, material characteristics as well as the adhesion properties may change significantly. Additionally, the adhesive is exposed to conventional aging in building skin as the temperature ranges between -20°C and +80°C. This paper focuses on the effect of water on load-bearing adhesives in a bioenergy facade. It evaluates potential adhesives for permanent hydrothermal application.  The paper introduces water as a key aging medium. Furthermore, it describes the construction of an innovative flat plate photobioreactor as an example for load-bearing adhesives under permanent hydrothermal treatment. The conditions inside the photobioreactor, which lead to particular mechanical, physical and chemical loads for constructive elements in comparison with conventional facade systems are presented. The main part describes the results of experimental tensile tests on the adhesive short-term behavior considering temperature conditioning and chemical treatment with substances emerging from bio-processing like storing in acid, base and hydrogen peroxide solution. The paper concludes with an outlook on future research work of the team including ARUP Deutschland GmbH (Berlin, Germany), ADCO Technik GmbH (Rostock, Germany), SSC GmbH (Hamburg, Germany) and Technische Universität Dresden (Dresden, Germany)

    Graph Partitioning with Acyclicity Constraints

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    Graphs are widely used to model execution dependencies in applications. In particular, the NP-complete problem of partitioning a graph under constraints receives enormous attention by researchers because of its applicability in multiprocessor scheduling. We identified the additional constraint of acyclic dependencies between blocks when mapping streaming applications to a heterogeneous embedded multiprocessor. Existing algorithms and heuristics do not address this requirement and deliver results that are not applicable for our use-case. In this work, we show that this more constrained version of the graph partitioning problem is NP-complete and present heuristics that achieve a close approximation of the optimal solution found by an exhaustive search for small problem instances and much better scalability for larger instances. In addition, we can show a positive impact on the schedule of a real imaging application that improves communication volume and execution time

    Labor Relations at a Major Airline: Exploring Employee Performance Strategies

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    Globally, the aviation industry supports 58.1 million jobs in related industries and U.S. airlines alone generated 11.8 million jobs. Airline performance, productivity, and profitability depend on employees. The purpose of this single case study was to explore the strategies that U.S. airline leaders use to improve employee performance. The study was grounded with the Harvard model of human resource management. A stratified purposeful sample of 14 managers and 10 frontline staff from a Florida airline participated in semistructured individual interviews and a focus group, respectively. The data from these interviews were analyzed using Moustakas\u27s modified van Kaam method. The themes that emerged from analysis included: an emphasis on the individual interaction and verbal affirmations between managers and frontline staff, additional career development opportunities for employees, not only for performing in their role but improving performance and level of commitment to the organization. Furthermore, managers and employees arrived at the same conclusion about organization culture and commitment-individuals have to feel they are contributing to the overall mission and feel valued in doing so. For the latter to occur, leaders need to engage employees in continuous dialogue and be completely transparent, and employees need to be open to feedback and share their motivations and goals. Social change implications include improved management and labor relationships within the U.S. airline industry, which ultimately benefits the flying public through greater stability and better service

    Erhöht Expertise die Kapazität des visuellen Arbeitsgedächnisses durch effizientere neuronale Kodierung?

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    Religiöse Kleidung ohne Religionsfreiheit?

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    Das Bistum Halberstadt 1. Das Stift St. Nikolaus in Stendal

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    Christian Popp, Das Bistum Halberstadt 1: Das Stift St. Nikolaus in Stendal (Germania Sacra N. F. 49), Berlin/New York 2007

    Rapid Raman spectroscopic analysis of stress induced degradation of the pharmaceutical drug tetracycline

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    Stress factors caused by inadequate storage can induce the unwanted degradation of active compounds in pharmaceutical formulations. Resonance Raman spectroscopy is presented as an analytical tool for rapid monitoring of small concentration changes of tetracycline and the metabolite 4-epianhydrotetracycline. These degradation processes were experimentally induced by changes in temperature, humidity, and irradiation with visible light over a time period of up to 23 days. The excitation wavelength ?exc = 413 nm was proven to provide short acquisition times for the simultaneous Raman spectroscopic detection of the degradation of tetracycline and production of its impurity in small sample volumes. Small concentration changes could be detected (down to 1.4% for tetracycline and 0.3% for 4-epianhydrotetracycline), which shows the potential of resonance Raman spectroscopy for analyzing the decomposition of pharmaceutical products. © 2020 by the authors

    Antinociceptive activity of the S1P-receptor agonist FTY720

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    FTY720 is a novel immunosuppressive drug that inhibits the egress of lymphocytes from secondary lymphoid tissues and thymus. In its phosphorylated form FTY720 is a potent S1P receptor agonist. Recently it was also shown that FTY720 can reduce prostaglandin synthesis through the direct inhibition of the cytosolic phospholipase A2 (cPLA2). Since prostaglandins are important mediators of nociception, we studied the effects of FTY720 in different models of nociception. We found that intraperitoneal administration of FTY720 reduced dose-dependently the nociceptive behaviour of rats in the formalin assay. Although the antinociceptive doses of FTY720 were too low to alter the lymphocyte count, prostanoid concentrations in the plasma were dramatically reduced. Surprisingly, intrathecally administered FTY720 reduced the nociceptive behaviour in the formalin assay without altering spinal prostaglandin synthesis, indicating that additional antinociceptive mechanisms beside the inhibition of prostaglandin synthesis are involved. Accordingly, FTY720 reduced also the nociceptive behaviour in the spared nerve injury model for neuropathic pain which does not depend on prostaglandin synthesis. In this model the antinociceptive effect of FTY720 was similar to gabapentin, a commonly used drug to treat neuropathic pain. Taken together we show for the first time that FTY720 possesses antinociceptive properties and that FTY720 reduces nociceptive behaviour during neuropathic pain

    Consequences of altered eicosanoid patterns for nociceptive processing in mPGES-1-deficient mice

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    Cyclooxygenase-2 (COX-2)-dependent prostaglandin (PG) E2 synthesis in the spinal cord plays a major role in the development of inflammatory hyperalgesia and allodynia. Microsomal PGE2 synthase-1 (mPGES-1) isomerizes COX-2-derived PGH2 to PGE2. Here, we evaluated the effect of mPGES-1-deficiency on the noci-ceptive behavior in various models of nociception that depend on PGE2 synthesis. Surprisingly, in the COX-2-dependent zymosan-evoked hyperalgesia model, the nociceptive behavior was not reduced in mPGES-1-deficient mice despite a marked decrease of the spinal PGE2 synthesis. Similarly, the nociceptive behavior was unaltered in mPGES-1-deficient mice in the formalin test. Importantly, spinal cords and primary spinal cord cells derived from mPGES-1-deficient mice showed a redirection of the PGE2 synthesis to PGD2, PGF2α and 6-keto-PGF1α (stable metabolite of PGI2). Since the latter prostaglandins serve also as mediators of noci-ception they may compensate the loss of PGE2 synthesis in mPGES-1-deficient mice
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