366 resultados para Kaufmann, IsidorKaufmann, IsidorIsidorKaufmann


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To track down potential sites of material failure in the tile–mortar–substrate systems, locations and intensities of stress concentrations owing to drying-induced shrinkage are investigated. For this purpose, mechanical properties were measured on real systems and used as input parameters for numerical modeling of the effect of shrinkage of substrate and/or mortar using the finite element code Abaqus. On the base of different geometrical set-ups we demonstrate that stress concentrations in the mortar can become critical when (i) substantial mortar shrinkage occurs, (ii) substrate shrinkage can accumulate over considerable spatial distances, particularly (iii) in situations where the mortar layer is not separated from the substrate by a flexible waterproofing membrane. Hence material failure in the system tile–mortar–substrate can be prevented (or reduced) by (i) an application of the tiles after the major stages of substrate shrinkage, (ii) the use of elasto-plastic deformable tile adhesives which can react elastically on local stress concentrations, (iii) the implementation of flexible membranes, and (iv) a reduction of the field size by the installation of flexible joints.

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We report on the EPICA Dronning Maud Land (East Antarctica) deep drilling operation. Starting with the scientific questions that led to the outline of the EPICA project, we introduce the setting of sister drillings at NorthGRIP and EPICA Dome C within the European ice-coring community. The progress of the drilling operation is described within the context of three parallel, deep-drilling operations, the problems that occurred and the solutions we developed. Modified procedures are described, such as the monitoring of penetration rate via cable weight rather than motor torque, and modifications to the system (e.g. closing the openings at the lower end of the outer barrel to reduce the risk of immersing the drill in highly concentrated chip suspension). Parameters of the drilling (e.g. core-break force, cutter pitch, chips balance, liquid level, core production rate and piece number) are discussed. We also review the operational mode, particularly in the context of achieved core length and piece length, which have to be optimized for drilling efficiency and core quality respectively. We conclude with recommendations addressing the design of the chip-collection openings and strictly limiting the cable-load drop with respect to the load at the start of the run.

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Globalized interurban competition is affecting cities of various sizes and locations. Small and medium-sized cities have to find ways to position themselves in global markets by formulating locational policies. This paper outlines an analytical framework of locational policies that cities adopt in order to increase their competitiveness. By comparing two European small and mediumsized cities (Lucerne and Ulm), we examine manifestations of locational policies and compare if these policies are being diverse or resemble each other. We found that strategies of both cities are sharing the intentions to be competitive, but their policy choices differ because the economic and political context is enabling or restricting certain kinds of locational policies. Furthermore, the findings point to the high explanatory power of municipal tax autonomy when studying locational policies.

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Autophagy has been demonstrated to have an essential function in several cellular hematopoietic differentiation processes, for example, the differentiation of reticulocytes. To investigate the role of autophagy in neutrophil granulopoiesis, we studied neutrophils lacking autophagy-related (Atg) 5, a gene encoding a protein essential for autophagosome formation. Using Cre-recombinase mediated gene deletion, Atg5-deficient neutrophils showed no evidence of abnormalities in morphology, granule protein content, apoptosis regulation, migration, or effector functions. In such mice, however, we observed an increased proliferation rate in the neutrophil precursor cells of the bone marrow as well as an accelerated process of neutrophil differentiation, resulting in an accumulation of mature neutrophils in the bone marrow, blood, spleen, and lymph nodes. To directly study the role of autophagy in neutrophils, we employed an in vitro model of differentiating neutrophils that allowed modulating the levels of ATG5 expression, or, alternatively, intervening pharmacologically with autophagy-regulating drugs. We could show that autophagic activity correlated inversely with the rate of neutrophil differentiation. Moreover, pharmacological inhibition of p38 MAPK or mTORC1 induced autophagy in neutrophilic precursor cells and blocked their differentiation, suggesting that autophagy is negatively controlled by the p38 MAPK-mTORC1 signaling pathway. On the other hand, we obtained no evidence for an involvement of the PI3K-AKT or ERK1/2 signaling pathways in the regulation of neutrophil differentiation. Taken together, these findings show that, in contrast to erythropoiesis, autophagy is not essential for neutrophil granulopoiesis, having instead a negative impact on the generation of neutrophils. Thus, autophagy and differentiation exhibit a reciprocal regulation by the p38-mTORC1 axis.

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SBR759 is a novel polynuclear iron(III) oxide–hydroxide starch·sucrose·carbonate complex being developed for oral use in chronic kidney disease (CKD) patients with hyperphosphatemia on hemodialysis. SBR759 binds inorganic phosphate released by food uptake and digestion in the gastro-intestinal tract increasing the fecal excretion of phosphate with concomitant reduction of serum phosphate concentrations. Considering the high content of ∼20% w/w covalently bound iron in SBR759 and expected chronic administration to patients, absorption of small amounts of iron released from the drug substance could result in potential iron overload and toxicity. In a mechanistic iron uptake study, 12 healthy male subjects (receiving comparable low phosphorus-containing meal typical for CKD patients: ≤1000 mg phosphate per day) were treated with 12 g (divided in 3 × 4 g) of stable 58Fe isotope-labeled SBR759. The ferrokinetics of [58Fe]SBR759-related total iron was followed in blood (over 3 weeks) and in plasma (over 26 hours) by analyzing with high precision the isotope ratios of the natural iron isotopes 58Fe, 57Fe, 56Fe and 54Fe by multi-collector inductively coupled mass spectrometry (MC-ICP-MS). Three weeks following dosing, the subjects cumulatively absorbed on average 7.8 ± 3.2 mg (3.8–13.9 mg) iron corresponding to 0.30 ± 0.12% (0.15–0.54%) SBR759-related iron which amounts to approx. 5-fold the basal daily iron absorption of 1–2 mg in humans. SBR759 was well-tolerated and there was no serious adverse event and no clinically significant changes in the iron indices hemoglobin, hematocrit, ferritin concentration and transferrin saturation.

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We present precise iron stable isotope ratios measured by multicollector-ICP mass spectrometry (MC-ICP-MS) of human red blood cells (erythrocytes) and blood plasma from 12 healthy male adults taken during a clinical study. The accurate determination of stable isotope ratios in plasma first required substantial method development work, as minor iron amounts in plasma had to be separated from a large organic matrix prior to mass-spectrometric analysis to avoid spectroscopic interferences and shifts in the mass spectrometer's mass-bias. The 56Fe/54Fe ratio in erythrocytes, expressed as permil difference from the “IRMM-014” iron reference standard (δ56/54Fe), ranges from −3.1‰ to −2.2‰, a range typical for male Caucasian adults. The individual subject erythrocyte iron isotope composition can be regarded as uniform over the 21 days investigated, as variations (±0.059 to ±0.15‰) are mostly within the analytical precision of reference materials. In plasma, δ56/54Fe values measured in two different laboratories range from −3.0‰ to −2.0‰, and are on average 0.24‰ higher than those in erythrocytes. However, this difference is barely resolvable within one standard deviation of the differences (0.22‰). Taking into account the possible contamination due to hemolysis (iron concentrations are only 0.4 to 2 ppm in plasma compared to approx. 480 ppm in erythrocytes), we model the pure plasma δ56/54Fe to be on average 0.4‰ higher than that in erythrocytes. Hence, the plasma iron isotope signature lies between that of the liver and that of erythrocytes. This difference can be explained by redox processes involved during cycling of iron between transferrin and ferritin.

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In the framework of the European Research Area for Agricultural Research for Development (ERA-ARD) project, a survey of innovative approaches in capacity development (CD) was undertaken. All Consortium members were asked to describe innovative approaches and best practices of CD mechanisms within their ARD programmes. A tabular overview of all the programmes or mechanisms can be found on page 4. Abstracts of the programmes or mechanisms are compiled in alphabetic order of the consortium members in this document. The intention of this catalogue of mechanisms is to give an overview of different approaches and practices and not to provide a comprehensive mapping of all the ongoing CD activities of the Consortium members. Thus, the programmes described represent only a fraction of all the ongoing CD programmes on the national level.

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The aim of the present paper is: 1. To provide definitions and outline trends in capacity development in Agricultural Research for Development (ARD) 2. to summarize the findings and recommendations of recent documents on planning and conducting capacity development activities in ARD 3. to present a summary and a compilation of best practices and innovative capacity development approaches among ERA-ARD consortium members 4. to derive basic principles for capacity development in ARD and to define entry points for joint and/or transnational activities to strengthen capacity development in ARD.