243 research outputs found

    Mindestlöhne – Zur Mikroökonomik des Arbeitsangebots

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    Mindestlohn, Niedriglohn, Arbeitsplatz, Beschäftigungseffekt, Schwarzarbeit, Schattenwirtschaft, Ordnungspolitik, Arbeitslosigkeit, Arbeitsmarkt, Reform, Dumping, Arbeitnehmer, Armut, Humankapital, Arbeitsangebot, Sozialstaat, Deutschland

    Die Methode der Gleichgewichtsbewegung als Approximationsverfahren

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    (Approximation by Moving Equilibrium). The analysis of multivariate dynamical models can sometimes be considerably simplified by the assumption that one or several variables move infinitely fast to their equilibrium values. The method is known as the 'moving equilibrium method'. Various dynamical theories that build on equilibrated markets presuppose the validity of this method. The method is discussed and a theorem -- the moving equilibrium theorem -- is provided that establishes the validity of the approximation in the linear case

    Evidenz und Tradition am Beispiel der Phytopharmaka

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    Summary Herbal medicinal products - Evidence and tradition from a historical perspective Background: Aside from the fully licensed herbal medicines there are products on the European pharmaceutical market which are registered by virtue of their longstanding traditional use. The normal registration procedure does not apply to them because presently they do not meet the legal requirements for a full license as set out in the relevant European Union Directive. One of these requirements, proof of tradition, has so far been dealt with in different ways and fails to meet the criteria of good practice. Method: This analysis is based on a selective literature search in PubMed and in databases of medical and pharmaceutical history, interviews with licensing experts, a consensus meeting attended by researchers with a background in general medicine, phytotherapy, medical and pharmaceutical history, biometry, ethnopharmacology, pharmacognosy and the pharmaceutical industry. Results and discussion: The 2004 EU Directive, which governs the registration of Traditional Herbal Medicinal Products and demands proof of tradition, is a regulatory construct and, above all, the outcome of a political process that has ended in a pragmatic compromise. The concept of tradition applied in the Directive does not sufficiently reflect the semantic breadth of the term. The only condition defined is that a specific commercial preparation needs to have been on the market for 30 years (15 of them inside the EU). Such an approach does not make full scientific use of the evidence available because the information excerpted from historical sources, if adequately processed, may yield valuable insights. This applies to indications, modes of application, efficacy and product safety (innocuousness). Such criteria should enter in full into the benefit-risk-analysis of applied preparations, in the registration process as well as in the therapeutic practice. Conclusion: When registering Traditional Herbal Medicinal Products the criterion of evidence-based medicine will only be met if all the facts available are assessed and evaluated, over and above the formally stipulated regulatory provisions (30 years, product reference). To this end, the scientific methods (from among the natural, life or cultural sciences), which are recognized as authoritative in each case, must be applied

    Eugenia jambolana Lam. Berry Extract Inhibits Growth and Induces Apoptosis of Human Breast Cancer but Not Non-Tumorigenic Breast Cells

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    The ripe purple berries of the native Indian plant Eugenia jambolana Lam., known as Jamun, are popularly consumed and available in the United States in Florida and Hawaii. Despite the growing body of data on the chemopreventive potential of edible berry extracts, there is paucity of such data for Jamun fruit. Therefore our laboratory initiated the current study with the following objectives: (1) to prepare a standardized Jamun fruit extract (JFE) for biological studies and (2) to investigate the antiproliferative and pro-apoptotic effects of JFE in estrogen dependent/aromatase positive (MCF-7aro), and estrogen independent (MDA-MB-231) breast cancer cells, and in a normal/nontumorigenic (MCF-10A) breast cell line. JFE was standardized to anthocyanin content using the pH differential method, and individual anthocyanins were identified by high performance liquid chromatography with ultraviolet (HPLC−UV) and tandem mass spectrometry (LC−MS/MS) methods. JFE contained 3.5% anthocyanins (as cyanidin-3-glucoside equivalents) which occur as diglucosides of five anthocyanidins/aglycons: delphinidin, cyanidin, petunidin, peonidin and malvidin. In the proliferation assay, JFE was most effective against MCF-7aro (IC50 = 27 μg/mL), followed by MDA-MB-231 (IC50 = 40 μg/mL) breast cancer cells. Importantly, JFE exhibited only mild antiproliferative effects against the normal MCF-10A (IC50 \u3e 100 μg/mL) breast cells. Similarly, JFE (at 200 μg/mL) exhibited pro-apoptotic effects against the MCF-7aro (p ≤ 0.05) and the MDA-MB-231 (p ≤ 0.01) breast cancer cells, but not toward the normal MCF-10A breast cells. These studies suggest that JFE may have potential beneficial effects against breast cancer

    The FERM protein EPB41L5 regulates actomyosin contractility and focal adhesion formation to maintain the kidney filtration barrier

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    Podocytes form the outer part of the glomerular filter, where they have to withstand enormous transcapillary filtration forces driving glomerular filtration. Detachment of podocytes from the glomerular basement membrane precedes most glomerular diseases. However, little is known about the regulation of podocyte adhesion in vivo. Thus, we systematically screened for podocyte-specific focal adhesome (FA) components, using genetic reporter models in combination with iTRAQ-based mass spectrometry. This approach led to the identification of FERM domain protein EPB41L5 as a highly enriched podocyte-specific FA component in vivo. Genetic deletion of Epb41l5 resulted in severe proteinuria, detachment of podocytes, and development of focal segmental glomerulosclerosis. Remarkably, by binding and recruiting the RhoGEF ARGHEF18 to the leading edge, EPB41L5 directly controls actomyosin contractility and subsequent maturation of focal adhesions, cell spreading, and migration. Furthermore, EPB41L5 controls matrix-dependent outside-in signaling by regulating the focal adhesome composition. Thus, by linking extracellular matrix sensing and signaling, focal adhesion maturation, and actomyosin activation EPB41L5 ensures the mechanical stability required for podocytes at the kidney filtration barrier. Finally, a diminution of EPB41L5-dependent signaling programs appears to be a common theme of podocyte disease, and therefore offers unexpected interventional therapeutic strategies to prevent podocyte loss and kidney disease progression

    Selective endocytosis controls slit diaphragm maintenance and dynamics in Drosophila nephrocytes

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    The kidneys generate about 180 liters of primary urine per day by filtration of plasma. An essential part of the filtration barrier is the slit diaphragm, a multiprotein complex containing nephrin as major component. Filter dysfunction typically manifests with proteinuria and mutations in endocytosis regulating genes were discovered as causes of proteinuria. However, it is unclear how endocytosis regulates the slit diaphragm and how the filtration barrier is maintained without either protein leakage or filter clogging. Here we study nephrin dynamics in podocyte-like nephrocytes of Drosophila and show that selective endocytosis either by dynamin- or flotillin-mediated pathways regulates a stable yet highly dynamic architecture. Short-term manipulation of endocytic functions indicates that dynamin-mediated endocytosis of ectopic nephrin restricts slit diaphragm formation spatially while flotillin-mediated turnover of nephrin within the slit diaphragm is needed to maintain filter permeability by shedding of molecules bound to nephrin in endosomes. Since slit diaphragms cannot be studied in vitro and are poorly accessible in mouse models, this is the first analysis of their dynamics within the slit diaphragm multiprotein complex. Identification of the mechanisms of slit diaphragm maintenance will help to develop novel therapies for proteinuric renal diseases that are frequently limited to symptomatic treatment

    Biallelic loss of function variants in PPP1R21 cause a neurodevelopmental syndrome with impaired endocytic function

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    Next‐generation sequencing (NGS) has been instrumental in solving the genetic basis of rare inherited diseases, especially neurodevelopmental syndromes. However, functional workup is essential for precise phenotype definition and to understand the underlying disease mechanisms. Using whole exome (WES) and whole genome sequencing (WGS) in four independent families with hypotonia, neurodevelopmental delay, facial dysmorphism, loss of white matter, and thinning of the corpus callosum, we identified four previously unreported homozygous truncating PPP1R21 alleles: c.347delT p.(Ile116Lysfs*25), c.2170_2171insGGTA p.(Ile724Argfs*8), c.1607dupT p.(Leu536Phefs*7), c.2063delA p.(Lys688Serfs*26) and found that PPP1R21 was absent in fibroblasts of an affected individual, supporting the allele's loss of function effect. PPP1R21 function had not been studied except that a large scale affinity proteomics approach suggested an interaction with PIBF1 defective in Joubert syndrome. Our co‐immunoprecipitation studies did not confirm this but in contrast defined the localization of PPP1R21 to the early endosome. Consistent with the subcellular expression pattern and the clinical phenotype exhibiting features of storage diseases, we found patient fibroblasts exhibited a delay in clearance of transferrin‐488 while uptake was normal. In summary, we delineate a novel neurodevelopmental syndrome caused by biallelic PPP1R21 loss of function variants, and suggest a role of PPP1R21 within the endosomal sorting process or endosome maturation pathway

    Transcranial direct current stimulation over multiple days improves learning and maintenance of a novel vocabulary

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    Introduction: Recently, growing interest emerged in the enhancement of human potential by means of non-invasive brain stimulation. In particular, anodal transcranial direct current stimulation (atDCS) has been shown to exert beneficial effects on motor and higher cognitive functions. However, the majority of transcranial direct current stimulation (tDCS) studies have assessed effects of single stimulation sessions that are mediated by transient neural modulation. Studies assessing the impact of multiple stimulation sessions on learning that may induce long-lasting behavioural and neural changes are scarce and have not yet been accomplished in the language domain in healthy individuals
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