The Controversial Role of HCY and Vitamin B Deficiency in Cardiovascular Diseases

Plasma homocysteine (HCY) is an established risk factor for cardiovascular disease CVD and stroke. However, more than two decades of intensive research activities has failed to demonstrate that Hcy lowering through B-vitamin supplementation results in a reduction in CVD risk. Therefore, doubts about a causal involvement of hyperhomocysteinemia (HHcy) and B-vitamin deficiencies in atherosclerosis persist. Existing evidence indicates that HHcy increases oxidative stress, causes endoplasmatic reticulum (ER) stress, alters DNA methylation and, thus, modulates the expression of numerous pathogenic and protective genes. Moreover, Hcy can bind directly to proteins, which can change protein function and impact the intracellular redox state. As most mechanistic evidence is derived from experimental studies with rather artificial settings, the relevance of these results in humans remains a matter of debate. Recently, it has also been proposed that HHcy and B-vitamin deficiencies may promote CVD through accelerated telomere shortening and telomere dysfunction. This review provides a critical overview of the existing literature regarding the role of HHcy and B-vitamin deficiencies in CVD. At present, the CVD risk associated with HHcy and B vitamins is not effectively actionable. Therefore, routine screening for HHcy in CVD patients is of limited value. However, B-vitamin depletion is rather common among the elderly, and in such cases existing deficiencies should be corrected. While Hcy-lowering with high doses of B vitamins has no beneficial effects in secondary CVD prevention, the role of Hcy in primary disease prevention is insufficiently studied. Therefore, more intervention and experimental studies are needed to address existing gaps in knowledge

Linguosomatische Sprachdidaktik : Wissenschaftstheoretische Grundlegung

Die Theorie des sprachlichen Lernens und Lehrens ist bis in die siebziger Jahre des 20. Jahrhunderts hinein eine "Meisterlehre" (Müller-Michaels 1980) gewesen. Große Vorbilder eines Volkes (z.B. Mose), Leiter philosophischer Schulen (z.B. Platon) oder Äbte von Klöstern (z.B. Augustinus) und schließlich staatlich geprüfte Oberstudiendirektoren (z.B. Ulshöfer) beschrieben den jüngeren Kollegen, was sich beim Lehren der Sprache über Jahrzehnte bewährt habe: wie man am besten den Sprachunterricht erteile (Müller 1922, Seidemann 1973, Ulshöfer 1968, Essen 1968). Mit der Etablierung der Sprachdidaktiken an den Universitäten ist das Konzept der "norm-setzenden Handlungswissenschaften" Müller-Michaels 1980, Ivo 1975) entwickelt worden. Der Forscher (nicht mehr als Meister der Praxis ausgewiesen) untersucht die Prozesse des sprachlichen Lehrens und Lernens, indem er im "Feld" des Praktikers Erhebungen anstellt, um anschließend die erhobenen Daten einer Hypothesenprüfung zu unterziehen. Als Handlungsfeld wird besonders die Schule berücksichtigt. Die Methoden der Forschung sind vorwiegend "quasi-experimentell". In der Nachfolge der Sprachtheorie Chomsky´s (Chomsky 1965) sind die experimentellen Ansätze zur Untersuchung des Spracherwerbs, der Spracherwerbsstörung und der betreffenden Interventionen entwickelt worden (de Villiers/ de Villiers 1970, Hörmann 1978). Ort der Untersuchung ist das Labor. Das Design dieser Sprachdidaktik (bzw. Psycholinguistik, Kognitionswissenschaften etc.) ist experimentell (z.B. Herrmann 2004). Alle drei Konzepte stehen sich in vielerlei Hinsicht antagonistisch gegenüber. Sie auseinander zu halten - und andererseits mit Gewinn aufeinander zu beziehen -, gehört zu den Basis-Fähigkeiten der linguosomatischen Berufe und ihrer zugrundeliegenden Theorie (Beispiel Sprachlehrberufe, Phoniatrie, Sprachheil-Sonderpädagogik, psychosomatische Sprachtherapien). Daher sind die signifikanten Gegensätze der drei Konzepte herauszuarbeiten und ihre widerstrebenden Konsequenzen aufeinander zu beziehen

Towards rigorous micro-macro transitions: The microscopic oscillator motion

The atomic chain whose dynamics evolve according to Newton's equations of motion serves as a simple microscopic many-particle system for an analysis of the macroscopic or thermodynamic limit. If the interaction potential has a sufficient strong repulsive part, it is possible to create a special microscopic motion, that we call oscillator motion, which is simpler as the classical thermal motion. However, also the oscillator motion leads to temperature, a Gibbs equation and an entropy. In the current paper we derive the thermodynamics for the oscillator motion without the subtle replacement of the many-particle sytem by a single equation of motion as it is done in [4]. Furthermore we introduce a different mathematical setting for micro-macro transitions as in [4], which is better suited for a rigorous treatment

A simple but rigorous micro-macro transition

This paper is devoted to a case study of micro-macro transitions. The main objective is the mathematically rigorous description of the macroscopic behavior of highly oscillating microscopic variables. In particular, we show that the theory of Young measures provides an elegant approach to this problem. A nontrivial application of the results is given in WIAS-Preprint 724

On the approximation of periodic traveling waves for the nonlinear atomic chain

We study a scheme from \cite{FV99}, which allows to approximate periodic traveling waves in the nonlinear atomic chain with nearest neighbour interactions. We prove a compactness result for this scheme, and derive some generalizations. Moreover, we discuss the thermodynamic properties of traveling waves

Numerical experiments on the modulation theory for the nonlinear atomic chain

Modulation theory with periodic traveling waves is a powerful, but not rigorous tool to derive a thermodynamic description for the atomic chain. We investigate the validity of this theory by means of several numerical experiments

Relation between homocysteine and biochemical bone turnover markers and bone mineral density in peri- and post-menopausal women

Background: Recently, increased plasma homocysteine (Hcy) has been suggested as an independent risk factor for osteoporotic fractures. Therefore, it is tempting to speculate that Hcy adversely affects bone metabolism. This study aimed to analyze the relation between Hcy and biochemical markers of bone metabolism and bone mineral density (BMD). Materials and methods: We investigated 143 peri- and post-menopausal women [median age (25th-75th percentile), 67 (57-75) years]. All subjects underwent a detailed medical examination, measurement of bone mineral density at lumbar spine (BMD-LS) and total hip (BMD-HIP), and fasting venous blood and urine sampling. Osteocalcin (OC), serum calcium (Ca), urinary desoxypyridinoline cross-links (DPD), osteoprotegerin (OPG) and soluble receptor activator of NF-κB ligand (sRANKL) were studied. Results: According to BMD subjects were classified as normal (n=24), osteopenic (n=51) or osteoporotic (n=68). Median Hcy did not differ between normal, osteopenic and osteoporotic subjects (p=0.647). Partial correlation analysis, controlling for the major confounders, age, creatinine, menopause and previous fractures, revealed significant correlations between Hcy and DPD (r=0.193, p=0.022), as well as between Hcy and Ca (r=0.170, p=0.045). After adjustment for the same confounders, subsequent regression analysis confirmed significant associations of Hcy with DPD and Ca. No significant relations could be observed between Hcy and BMD-LS, BMD-HIP, OC, OPG or sRANKL. Conclusion: Our results demonstrate weak, but significant, relations between Hcy and markers of organic and inorganic bone resorption, suggesting a mechanistic role of Hcy in bone metabolism. The relation between Hcy and bone resorption was not dependent on OPG or sRANK

Divertor Heat Load in ASDEX Upgrade L-Mode in Presence of External Magnetic Perturbation

Power exhaust is one of the major challenges for a future fusion device. Applying a non-axisymmetric external magnetic perturbation is one technique that is studied in order to mitigate or suppress large edge localized modes which accompany the high confinement regime in tokamaks. The external magnetic perturbation brakes the axisymmetry of a tokamak and leads to a 2D heat flux pattern on the divertor target. The 2D heat flux pattern at the outer divertor target is studied on ASDEX Upgrade in stationary L-Mode discharges. The amplitude of the 2D characteristic of the heat flux depends on the alignment between the field lines at the edge and the vacuum response of the applied magnetic perturbation spectrum. The 2D characteristic reduces with increasing density. The increasing divertor broadening $S$ with increasing density is proposed as the main actuator. This is supported by a generic model using field line tracing and the vacuum field approach that is in quantitative agreement with the measured heat flux. The perturbed heat flux, averaged over a full toroidal rotation of the magnetic perturbation, is identical to the non-perturbed heat flux without magnetic perturbation. The transport qualifiers, power fall-off length $\lambda_q$ and divertor broadening $S$, are the same within the uncertainty compared to the unperturbed reference. No additional cross field transport is observed.Comment: 23 pages, 28 figures. This is an author-created, un-copyedited version of an article submitted for publication in Plasma Physics and Controlled Fusion. IoP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i