Histological and compositional responses of bone to immobilization and other experimental conditions

Histological techniques were utilized for evaluating progressive changes in tibial compact bone in adult male monkeys during chronic studies of immobilization-associated osteopenia. The animals were restrained in a semirecumbent position which reduces normally occurring stresses in the lower extremities and results in bone mass loss. The longest immobilization studies were of seven months duration. Losses of haversian bone tended to occur predominatly in the proximal tibia and were characterized by increased activation with excessive depth of penetration of osteoclastic activity. There was no apparent regulation of the size and orientation of resorption cavities. Rapid bone loss seen during 10 weeks of immobilization appeared to be due to unrestrained osteoclastic activity without controls and regulation which are characteristic of adaptive systems. The general pattern of loss persisted throughout 7 months of immobilization. Clear cut evidence of a formation phase in haversian bone was seen only after two months of reambulation

Besteht ein Zusammenhang von Alkoholkonsum und sexuellem Risikoverhalten? Eine Diskussion konzeptioneller Aspekte am Beispiel HIV-infizierter Männer mit homosexuellem Verhalten

Zusammenfassung: Besteht ein Zusammenhang zwischen Alkoholkonsum und sexuellen Risikokontakten? Führt Alkohol zu Risikokontakten? Es lassen sich zahlreiche Studien finden, die diese Frage bejaht haben. Ebenso lassen sich Studien finden, die mit modifizierten Forschungskonzepten diese Befunde nicht bestätigen konnten. Unter Verwendung von ereignisunspezifischen und situationsspezifischen Konzepten wurden diese Fragen bei einer Stichprobe von 64 HIV-infizierten Männern mit homosexuellem Verhalten untersucht. Einen signifikanten Zusammenhang von Alkoholkonsum und sexuellem Risikoverhalten konnten wir mit dem ereignisun-spezifischen Ansatz nicht feststellen. Auch Personen, die sexuelle Kontakte unter Alkoholeinfluss eingegangen waren (situationsspezifisches Konzept), gingen nicht überdurchschnittlich häufiger Risikokontakte ein. Die Personen hingegen, die unter Alkoholkonsum riskante sexuelle Praktiken eingegangen waren, erreichen sowohl hinsichtlich des Alkoholkonsums als auch des allgemein erfassten Schutz- und Risikoverhaltens lediglich Durchschnittswerte. Erst konkrete Zusatzfragen machen es möglich, sie als Personen mit Risikoverhalten zu identifizieren. Für Untersuchungen zum sexuellen Schutz- und Risikoverhalten erscheint die Kombination sich ergänzender Forschungskonzepte zweckmässi

Parasitic small-moment-antiferromagnetism and non-linear coupling of hidden order and antiferromagnetism in URu2Si2 observed by Larmor diffraction

We report simultaneous measurements of the distribution of lattice constants and the antiferromagnetic moment in high-purity URu2Si2, using both Larmor and conventional neutron diffraction, as a function of temperature and pressure up to 18 kbar. We establish that the tiny moment in the hidden order (HO) state is purely parasitic and quantitatively originates from the distribution of lattice constants. Moreover, the HO and large-moment antiferromagnetism (LMAF) at high pressure are separated by a line of first-order phase transitions, which ends in a bicritical point. Thus the HO and LMAF are coupled non-linearly and must have different symmetry, as expected of the HO being, e.g., incommensurate orbital currents, helicity order, or multipolar order.Comment: 4 pages, 4 figure

Pädagogische Antworten auf Gewalt in der Schule und auf Schulwegen : Präventions- und Interventionskonzepte mit einer exemplarischen Analyse der Wirkmechanismen, Reichweite und Nachhaltigkeit des Coolnesstrainings (CT) und der Schulbusbegleiterprogramme (SBB)

Kontrastiver Vergleich zweier Präventions- und Interventionsprogramme gegen Gewalt in der Schule und auf den Schulwegen mit einer exemplarischen Analyse der Wirkmechanismen, Reichweite und Nachhaltigkeit.Comparison two prevention and intervention programs against force in school and on the ways to school with an exemplary analysis of the working mechanisms, reach and sustainability

Effects of Ubiquinol-10 on MicroRNA-146a Expression In Vitro and In Vivo

MicroRNAs (miRs) are involved in key biological processes via suppression of gene expression at posttranscriptional levels. According to their superior functions, subtle modulation of miR expression by certain compounds or nutrients is desirable under particular conditions. Bacterial lipopolysaccharide (LPS) induces a reactive oxygen species-/NF-κB-dependent pathway which increases the expression of the anti-inflammatory miR-146a. We hypothesized that this induction could be modulated by the antioxidant ubiquinol-10. Preincubation of human monocytic THP-1 cells with ubiquinol-10 reduced the LPS-induced expression level of miR-146a to 78.9 ± 13.22%. In liver samples of mice injected with LPS, supplementation with ubiquinol-10 leads to a reduction of LPS-induced miR-146a expression to 78.12 ± 21.25%. From these consistent in vitro and in vivo data, we conclude that ubiquinol-10 may fine-tune the inflammatory response via moderate reduction of miR-146a expression

Bose-Einstein condensation and entanglement in magnetic systems

We present a study of magnetic field induced quantum phase transitions in insulating systems. A generalized scaling theory is used to obtain the temperature dependence of several physical quantities along the quantum critical trajectory ($H=H_{C}$, $T\to0$) where $H$ is a longitudinal external magnetic field and $H_{C}$ the critical value at which the transition occurs. We consider transitions from a spin liquid at a critical field $H_{C1}$ and from a fully polarized paramagnet, at $H_{C2}$, into phases with long range order in the transverse components. The transitions at $H_{C1}$ and $H_{C2}$ can be viewed as Bose-Einstein condensations of magnons which however belong to different universality classes since they have different values of the dynamic critical exponent $z$. Finally, we use that the magnetic susceptibility is an entanglement witness to discuss how this type of correlation sets in as the system approaches the quantum critical point along the critical trajectory, $H=H_{C2}$, $T\to0$.Comment: 7 pages, 1 Table; accepted version; changes in text and new reference

High pressure study of BaFe2As2 - role of hydrostaticity and uniaxial stress

We investigate the evolution of the electrical resistivity of BaFe2As2 single crystals with pressure. The samples used were from the same batch grown from self flux and showed properties that were highly reproducible. Samples were pressurised using three different pressure media: pentane-isopentane (in a piston cylinder cell), Daphne oil (in an alumina anvil cell) and steatite (in a Bridgman cell). Each pressure medium has its own intrinsic level of hydrostaticity, which dramatically affects the phase diagram. An increasing uniaxial pressure component in this system quickly reduces spin density wave order and favours the appearance of superconductivity, similar to what is seen in SrFe2As2.Comment: 11 page