Synaptic Remodeling in the Dentate Gyrus, CA3, CA1, Subiculum, and Entorhinal Cortex of Mice: Effects of Deprived Rearing and Voluntary Running

Hippocampal cell proliferation is strongly increased and synaptic turnover decreased after rearing under social and physical deprivation in gerbils (Meriones unguiculatus). We examined if a similar epigenetic effect of rearing environment on adult neuroplastic responses can be found in mice (Mus musculus). We examined synaptic turnover rates in the dentate gyrus, CA3, CA1, subiculum, and entorhinal cortex. No direct effects of deprived rearing on rates of synaptic turnover were found in any of the studied regions. However, adult wheel running had the effect of leveling layer-specific differences in synaptic remodeling in the dentate gyrus, CA3, and CA1, but not in the entorhinal cortex and subiculum of animals of both rearing treatments. Epigenetic effects during juvenile development affected adult neural plasticity in mice, but seemed to be less pronounced than in gerbils

Zur selbsttätig sicheren Begrenzung von nuklearer Leistung und Brennstofftemperatur in innovativen Kernreaktoren

Nuclear energy probably will not contribute significantly to the future worldwide energysupply until it can be made catastrophefree. Therefore it has to be shown, that theconsequences of even largest accidents will have no major impact to the environmentof a power plant.In this paper one of the basic conditions for such a nuclear technology is discussed.Using mainly the modular pebble-bed high-temperature reactor as an example, thedesign principles, analytical methods and the level of knowledge as given today incontrolling reactivity accidents by inherent safety features of innovative nuclear reactorsare described. Complementary possibilities are shown to reach this goal with systems ofdifferent types of construction . Questions open today and resulting requirements forfuture activities are discussed .Today's knowledge credibly supports the possibility of a catastrophefree nucleartechnology with respect to reactivity event

Inhibition of Lassa Virus Glycoprotein Cleavage and Multicycle Replication by Site 1 Protease-Adapted α1-Antitrypsin Variants

The virus family Arenaviridae includes several hemorrhagic fever causing agents such as Lassa, Guanarito, Junin, Machupo, and Sabia virus that pose a major public health concern to the human population in West African and South American countries. Current treatment options to control fatal outcome of disease are limited to the ribonucleoside analogue ribavirin, although its use has some significant limitations. The lack of effective treatment alternatives emphasizes the need for novel antiviral therapeutics to counteract these life-threatening infections. Maturation cleavage of the viral envelope glycoprotein by the host cell proprotein convertase site 1 protease (S1P) is critical for infectious virion production of several pathogenic arenaviruses. This finding makes this protease an attractive target for the development of novel anti-arenaviral therapeutics. We demonstrate here that highly selective S1P-adapted α1-antitrypsins have the potential to efficiently inhibit glycoprotein processing, which resulted in reduced Lassa virus replication. Our findings suggest that S1P should be considered as an antiviral target and that further optimization of modified α1-antitrypsins could lead to potent and specific S1P inhibitors with the potential for treatment of certain viral hemorrhagic fevers

Physikalische Untersuchungen zum D2_{2}O-moderierten Thoriumreaktor

Es werden die Ergebnisse einer detaillierten Untersuchung für einen D$_{2}$0-Th-Konverter vorgelegt. Dabei liegt die Auslegung eines Druckkesselreaktors zugrunde mit einer Brennelementanordnung in offenem Gitter. Die Ergebnisse sollen eine breite Grundlage zur Beurteilung dieses Konzeptes bilden. Die Studie wurde im Rahmen eines Arbeitsvertrages zwischen der Siemens AG und der Kernforschungsanlage Jülich durchgeführt. Im Vordergrund der Untersuchung steht eine Parameterstudie, bei der die Auslegungsdaten des Reaktor-Core variiert werden. Dazu simulieren Rechenprogramme das neutronenphysikalische Geschehen beim Abbrennvorgang und die Umsetz-, Beladungs- und Aufarbeitungsschemata. Es bildet sich nach dem Durchrechnen einer längeren Betriebszeit ein "Gleichgewichtscore" heraus, bei dem sich der Abbrandzyklus einer Beladungsperiode jeweils annähernd reproduziert. Die Gleichgewichtszyklen zu verschiedenen Coredaten-Parametersätzen sind die Grundlage einer Brennstoffzyklus-Kostenstudie, die durch eine Optimalisierung hinsichtlich der Konversionseigenschaftenergänzt wird. Ferner werden detaillierte Rechnungen vorgelegt für eine 300 MWe-Anlage, deren Auslegung so beschaffen ist, daß sie sich zum Bau als Prototyp-Anlage eignet. Im Rahmen der Arbeit wird eingehend auf die Erläuterung des physikalischen Hintergrundes eingegangen. Dieses trägt zum Verständnis der Vielfältigen Tendenzen bei und ermöglicht eine Einschätzung von Fällen, die nicht explizit behandelt werden. Die Rechnungen werden innerhalb des Programmzyklus V.S.O.P. durchgeführt, der in einer flexiblen Zusammengliederung der erforderlichen Rechenprogramme besteht. Um darzulegen, in welchem Maße die Studie dem tatsächlichen physikalischen Geschehen im Reaktor Rechnung trägt, wird in Abschnitt II ilber die Leistung dieses Zyklus berichtet

V. S. O. P. - Computer Code System for Reactor Physics and Fuel Cycle Simulation

V .S .O .P . (Very Superior Old Programs) is a system of codes linked together for the simulation of reactor life histories. It comprisesneutron cross section libraries and processing routines, repeated neutron spectrum evaluation, 2-D diffusion calculation based onneutron flux synthesis with depletion and shut-down features, incore and out-of-pile fuel management, fuel cycle cost analysis, and thermal hydraulics (at present restricted to Pebble Bed HTRs). Various techniques have been employed to accelerate the iterativeprocesses and to optimize the internal data transfer. A limitation of the storage requirement to 360 K-bites is achieved by an overlaystructure. The code system has been used extensively for comparison studies of reactors, their fuel cycles, and related detailed features. Beside its use in research and development work for the High Temperature Reactor the system has been applied successfully to Light Water and Heavy Water Reactors

Demonstration of dopamine-immunoreactive cells in the proximal convoluted tubule of gerbil (Meriones unguiculatus) kidney.

Dawirs RR, Teuchert-Noodt G. Demonstration of dopamine-immunoreactive cells in the proximal convoluted tubule of gerbil (Meriones unguiculatus) kidney. J Histochem Cytochem. 1992;40(8):1197-1201.We investigated dopamine immunoreactivity in the kidney of gerbils (Meriones unguiculatus). For that purpose a sensitive and selective antibody against glutaraldehyde-conjugated dopamine was applied. Dopamine-immunoreactive cells were found in the epithelium of the proximal convoluted tubule, where these cells revealed a typical segment-like distribution pattern. Dopamine-immunoreactive precipitates were small and concentrated at the apical pole of the labeled cells. This study has directly identified dopamine as a constituent of certain cells of the proximal convoluted tubule in gerbils. The functional significance of dopamine in these cells is discussed in relation to the present view of renal dopaminergic actions