A Non-Disordered Glassy Model with a Tunable Interaction Range

We introduce a non-disordered lattice spin model, based on the principle of minimizing spin-spin correlations up to a (tunable) distance R. The model can be defined in any spatial dimension D, but already for D=1 and small values of R (e.g. R=5) the model shows the properties of a glassy system: deep and well separated energy minima, very slow relaxation dynamics, aging and non-trivial fluctuation-dissipation ratio.Comment: 4 pages, 5 figure

Ryanodine Receptor Activation Induces Long-Term Plasticity of Spine Calcium Dynamics

A key feature of signalling in dendritic spines is the synapse-specific transduction of short electrical signals into biochemical responses. Ca2+ is a major upstream effector in this transduction cascade, serving both as a depolarising electrical charge carrier at the membrane and an intracellular second messenger. Upon action potential firing, the majority of spines are subject to global back-propagating action potential (bAP) Ca2+ transients. These transients translate neuronal suprathreshold activation into intracellular biochemical events. Using a combination of electrophysiology, two-photon Ca2+ imaging, and modelling, we demonstrate that bAPs are electrochemically coupled to Ca2+ release from intracellular stores via ryanodine receptors (RyRs). We describe a new function mediated by spine RyRs: the activity-dependent long-term enhancement of the bAP-Ca2+ transient. Spines regulate bAP Ca2+ influx independent of each other, as bAP-Ca2+ transient enhancement is compartmentalized and independent of the dendritic Ca2+ transient. Furthermore, this functional state change depends exclusively on bAPs travelling antidromically into dendrites and spines. Induction, but not expression, of bAP-Ca2+ transient enhancement is a spine-specific function of the RyR. We demonstrate that RyRs can form specific Ca2+ signalling nanodomains within single spines. Functionally, RyR mediated Ca2+ release in these nanodomains induces a new form of Ca2+ transient plasticity that constitutes a spine specific storage mechanism of neuronal suprathreshold activity patterns

Die Normalisierungsprozesstheorie als Ausgangspunkt für die Gestaltung von Lehre? Strategien für das gemeinsame Lernen heterogener Professionen

Wie kann multiprofessionelles Lehren und Lernen an Hochschulen normalisiert werden? Diese Frage wurde im Rahmen des Forschungsprojekts NorMultität untersucht. Die Normalisierungsprozesstheorie wurde als Ausgangspunkt für die Gestaltung von Lehre genommen. Die Theorie beschreibt vier Stufen, die durchlaufen werden müssen, um eine neue Praxis in die alltägliche Arbeit zu integrieren. Kohärenz, kognitive Partizipation, kollektives Handeln und reflexives Monitoring sind die Schlüsselbegriffe der Theorie. Die Ergebnisse des Projekts zeigen, dass multiprofessionelles Lehren und Lernen eine gemeinsame Wissensbasis erfordert, die durch Perspektivwechsel und Perspektivabgleich hergestellt werden kann. Die Handlungsstrategien der Lehrenden und Lernenden sollten darauf abzielen, ein gemeinsames Verständnis zu schaffen und den Austausch zu initiieren. Reflexives Monitoring ist notwendig, um die Konsequenzen des multiprofessionellen Lehrens und Lernens zu bewerten. (Herausgeber)How can multiprofessional teaching and learning be normalized at universities? This question was investigated in the research project NorMultität. The normalization process theory was taken as a starting point for the design of teaching. The theory describes four stages that must be passed through in order to integrate a new practice into everyday work. Coherence, cognitive participation, collective action, and reflexive monitoring are key concepts in the theory. The results of the project show that multiprofessional teaching and learning requires a common knowledge base, which can be established by changing and aligning perspectives. The action strategies of teachers and learners should aim at creating a common understanding and initiating exchange. Reflective monitoring is necessary to assess the consequences of multiprofessional teaching and learning. (Editor

Repeated lipoprotein apheresis and immune response: Effects on different immune cell populations

BACKGROUND Atherosclerosis is considered a chronic inflammation of arterial vessels with the involvement of several immune cells causing severe cardiovascular diseases. Lipoprotein apheresis (LA) improves cardiovascular conditions of patients with severely disturbed lipid metabolism. In this context, little is known about the impact of LA on various immune cell populations, especially over time. METHODS Immune cells of 18 LA-naïve patients starting weekly LA treatment were analyzed before and after four apheresis cycles over the course of 24 weeks by flow cytometry. RESULTS AND CONCLUSIONS An acute lowering effect of LA on T cell and natural killer (NK) cell subpopulations expressing CD69 was observed. The non-classical and intermediate monocyte subsets as well as HLA-DR$^{+}$ 6-sulfo LacNAc$^{+}$ monocytes were significantly reduced during the apheresis procedure. We conclude that LA has the capacity to alter various immune cell subsets. However, LA has mainly short-term effects than long-term consequences on proportions of immune cells

Effects of spermidine supplementation on cognition and biomarkers in older adults with subjective cognitive decline (SmartAge)—study protocol for a randomized controlled trial

Background: Given the global increase in the aging population and age-related diseases, the promotion of healthy aging is one of the most crucial public health issues. This trial aims to contribute to the establishment of effective approaches to promote cognitive and brain health in older individuals with subjective cognitive decline (SCD). Presence of SCD is known to increase the risk of objective cognitive decline and progression to dementia due to Alzheimer’s disease. Therefore, it is our primary goal to determine whether spermidine supplementation has a positive impact on memory performance in this at-risk group, as compared with placebo. The secondary goal is to examine the effects of spermidine intake on other neuropsychological, behavioral, and physiological parameters. Methods: The SmartAge trial is a monocentric, randomized, double-blind, placebo-controlled phase IIb trial. The study will investigate 12 months of intervention with spermidine-based nutritional supplementation (target intervention) compared with 12months of placebo intake (control intervention). We plan to recruit 100 cognitively normal older individuals with SCD from memory clinics, neurologists and general practitioners in private practice, and the general population. Participants will be allocated to one of the two study arms using blockwise randomization stratified by age and sex with a 1:1 allocation ratio. The primary outcome is the change in memory performance between baseline and post-intervention visits (12 months after baseline). Secondary outcomes include the change in memory performance from baseline to follow-up assessment (18months after baseline), as well as changes in neurocognitive, behavioral, and physiological parameters (including blood and neuroimaging biomarkers), assessed at baseline and post-intervention. Discussion: The SmartAge trial aims to provide evidence of the impact of spermidine supplementation on memory performance in older individuals with SCD. In addition, we will identify possible neurophysiological mechanisms of action underlying the anticipated cognitive benefits. Overall, this trial will contribute to the establishment of nutrition intervention in the prevention of Alzheimer’s disease

Use of a special bioreactor for the cultivation of a new flexible polyurethane scaffold for aortic valve tissue engineering

Background: Tissue engineering represents a promising new method for treating heart valve diseases. The aim of this study was evaluate the importance of conditioning procedures of tissue engineered polyurethane heart valve prostheses by the comparison of static and dynamic cultivation methods. Methods: Human vascular endothelial cells (ECs) and fibroblasts (FBs) were obtained from saphenous vein segments. Polyurethane scaffolds (n = 10) were primarily seeded with FBs and subsequently with ECs, followed by different cultivation methods of cell layers (A: static, B: dynamic). Group A was statically cultivated for 6 days. Group B was exposed to low flow conditions (t(1)=3 days at 750 ml/min, t(2)=2 days at 1100 ml/min) in a newly developed conditioning bioreactor. Samples were taken after static and dynamic cultivation and were analyzed by scanning electron microscopy (SEM), immunohistochemistry (IHC), and real time polymerase chain reaction (RT-PCR). Results: SEM results showed a high density of adherent cells on the surface valves from both groups. However, better cell distribution and cell behavior was detected in Group B. IHC staining against CD31 and TE-7 revealed a positive reaction in both groups. Higher expression of extracellular matrix (ICAM, Collagen IV) was observed in Group B. RT-PCR demonstrated a higher expression of inflammatory Cytokines in Group B. Conclusion: While conventional cultivation method can be used for the development of tissue engineered heart valves. Better results can be obtained by performing a conditioning step that may improve the tolerance of cells to shear stress. The novel pulsatile bioreactor offers an adequate tool for in vitro improvement of mechanical properties of tissue engineered cardiovascular prostheses

Handwerkliches Lackieren mit Virtual Reality (HandLeVR)

Kompetenzentwicklung in der beruflichen Aus- und Weiterbildung beinhaltet den Erwerb von Wissen, Fertigkeiten und Einstellungen, häufig mit einem Schwerpunkt auf psychomotorischer Koordination. Der Kompetenzerwerb in der Ausbildung zum Fahrzeuglackierer bzw. zur Fahrzeuglackiererin wird durch soziale, wirtschaftliche und ökologische Faktoren behindert. Um diese Hürden zu überwinden, entwickelt das Forschungsprojekt HandLeVR (Handlungsorientiertes Lernen in der VR-Lackierwerkstatt) ein Virtual-Reality-Training auf der Grundlage des empirisch validierten 4C/ID-Modells. Der Artikel stellt das Vorgehen und die Resultate des Projekts vor und präsentiert Ergebnisse einer ersten Evaluierungsstudie (z. B. zu Akzeptanz und Präsenzerleben)