Assembly of RNPs: help needed

This extract was created in the absence of an abstract: In 1968 the Nomura lab in Madison made an astonishing observation: when ribosomal proteins were mixed under appropriate conditions with 16S rRNA, fully functional ribosomal 30S subunits were formed. Along with the subsequent total reconstitution of 50S subunits, it was established that even entire ribosomes could be assembled in vitro from their constituents. Neither energy in the form of nucleoside triphosphates, nor other “helping factors,” were required for this reaction. It was thus concluded that the structural information required for the formation of even complex macromolecules lies within its individual components itself and hence allows “self assembly.” This notion was soon supported by many other labs, which managed to assemble macromolecular RNPs in spontaneous reactions, including the signal recognition particle (SRP), spliceosomal subcomplexes (U snRNPs) and nucleolar RNPs (snoRNPs), to name just a few. These findings were in full accordance with the observations of the Anfinsen lab in the 1950s

Optimization of nanostructured permalloy electrodes for a lateral hybrid spin-valve structure

Ferromagnetic electrodes of a lateral semiconductor-based spin-valve structure are designed to provide a maximum of spin-polarized injection current. A single-domain state in remanence is a prerequisite obtained by nanostructuring Permalloy thin film electrodes. Three regimes of aspect ratios $m$ are identified by room temperature magnetic force microscopy: (i) high-aspect ratios of $m \ge 20$ provide the favored remanent single-domain magnetization states, (ii) medium-aspect ratios $m \sim 3$ to $m \sim 20$ yield highly remanent states with closure domains and (iii) low-aspect ratios of $m \le 3$ lead to multi-domain structures. Lateral kinks, introduced to bridge the gap between micro- and macroscale, disturb the uniform magnetization of electrodes with high- and medium-aspect ratios. However, vertical flanks help to maintain a uniformly magnetized state at the ferromagnet-semiconcuctor contact by domain wall pinning.Comment: revised version, major structural changes, figures reorganized,6 pages, 8 figures, revte

Nährstoffsalden und Nitratgehalte des Sickerwassers in ökologisch und konventionell bewirtschafteter Ackerflächen

Die Nährstoffsalden ökologisch bewirtschafteter Betriebe lagen bei den Hauptnährstoffen Stickstoff, Phosphat und Kali deutlich unter den Salden konventionell bewirtschafteter Betriebe. Bei Phosphat und Kali wurden negative Salden festgestellt. Bei mittel- und langfristiger Betrachtung werden die pflanzenverfügbaren Bodengehalte sinken. Unter 10 mg/100 g Boden muss im Rahmen der zugelassenen Möglichkeiten eine Erhaltungsdüngung durchgeführt werden, wenn das mögliche Ertragspotential ausgeschöpft werden soll. Die dargestellten Unterschiede der Stickstoffsalden bei konventioneller und ökologischer Bewirtschaftung werden durch Untersuchungsergebnisse hinsichtlich der Nitratkonzentration im Sickerwasser bestätigt. Nach unseren Untersuchungen lag die Nitratkonzentration unterhalb des durchwurzelbaren Raumes unter ökologisch bewirtschafteten Flächen deutlich unter den Gehalten konventionell bewirtschafteter Flächen. Sie lagen aber im Mittel über dem Richtwert für Trinkwasser von 25mg/l

Analysis of induced gamma activation by D-T neutrons in selected fusion reactor relevant materials with EAF-2010

Samples of lanthanum, erbium and titanium which are constituents of structural materials, insulating coatings and tritium breeder for blankets of fusion reactor designs have been irradiated in a fusion peak neutron field. The induced gamma activities were measured and the results were used to check calculations with the European activation system EASY-2010. Good agreement for the prediction of major contributors to the contact dose rate of the materials was found, but for minor contributors the calculation deviated up to 50%

Condensate fragmentation as a sensitive measure of the quantum many-body behavior of bosons with long-range interactions

The occupation of more than one single-particle state and hence the emergence of fragmentation is a many-body phenomenon universal to systems of spatially confined interacting bosons. In the present study, we investigate the effect of the range of the interparticle interactions on the fragmentation degree of one- and two-dimensional systems. We solve the full many-body Schr\"odinger equation of the system using the recursive implementation of the multiconfigurational time-dependent Hartree for bosons method, R-MCTDHB. The dependence of the degree of fragmentation on dimensionality, particle number, areal or line density and interaction strength is assessed. It is found that for contact interactions, the fragmentation is essentially density independent in two dimensions. However, fragmentation increasingly depends on density the more long-ranged the interactions become. The degree of fragmentation is increasing, keeping the particle number $N$ fixed, when the density is decreasing as expected in one spatial dimension. We demonstrate that this remains, nontrivially, true also for long-range interactions in two spatial dimensions. We, finally, find that within our fully self-consistent approach, the fragmentation degree, to a good approximation, decreases universally as $N^{-1/2}$ when only $N$ is varied.Comment: 8 pages of RevTex4-1, 5 figure