Accelerated Growth Plate Mineralization and Foreshortened Proximal Limb Bones in Fetuin-A Knockout Mice

PMCID: PMC3473050This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Multi-device study of temporal characteristics of magnetohydrodynamic modes initiating disruptions

Disruptions in tokamaks are often preceded by magnetohydrodynamic (MHD) instabilities that can rotate or become locked to the wall. Measurements from magnetic diagnostics in the presence of MHD mode precursors to disruptions can yield potentially valuable input to the plasma control system, with a view to disruption avoidance, prediction and mitigation. This paper presents an exploratory analysis of the growth of MHD modes and corresponding time scales on the basis of magnetic measurements in multiple tokamaks. To this end, a database was compiled using disruptive discharges from COMPASS, ASDEX Upgrade, DIII-D and JET, manually classified according to disruption root cause, and characterized by a great diversity of operational conditions and mode dynamics. The typical time during which a mode can be detected using saddle coils and the duration of the locked mode phase in the database both extend over several orders of magnitude, but generally the time scales increase with plasma size. Several additional factors are discussed that can influence these durations, including the disruption root cause. A scaling law for the locked phase duration was estimated, yielding predictions toward ITER of the order of hundreds of milliseconds or even seconds. In addition, a scaling law for the mode amplitude at the disruption onset, proposed earlier by de Vries et al. (2016), is applied to the database, and its predictive capabilities are assessed. Despite significant uncertainty on the predictions from both scaling laws, encouraging trends are observed of the fraction of disruptions that may be detected with sufficient warning time to allow mitigation or even avoidance, based solely on observations of MHD mode dynamics. When combined with similar analysis of measurements from diagnostics that are sensitive to other disruption precursors, our analysis methods and results may contribute to the reliability, robustness and generalization of disruption warning schemes for ITER

Bee vectoring of biologicals in sunflowers as a crop protection tool

An inoculum dispenser system developed by Bee Vectoring Technology Inc. (BVT) fits inside commercial bumble bee hives and another system attaches to honey bee hives. Each system is one-way so that bees acquire inoculum powder when exiting the hive but not when returning to the hive. BVT’s dispensers are filled with VectoriteTM, which is a specially formulated and patented powder prepared from all natural materials mixed with one or more beneficial microorganisms. BVT’s own proprietary fungus, Clonostachys rosea strain CR-7, which is effective in controlling a number of devastating diseases such as Sclerotinia Head Rot (SHR). VectoriteTM adheres to bees, aiding in the transport of added active ingredients to flowers in the crop. Bumble bees can be universally used in greenhouse operations, and some countries approve their use in open field crops, whereas honey bees are exclusively used in open field conditions. The effectiveness of the BVT plant protection biocontrols combined with the pollination effi ciency of both insects, make the BVT system a solution that harnesses the power of nature’s best workers and microbials

XY models with disorder and symmetry-breaking fields in two dimensions

The combined effect of disorder and symmetry-breaking fields on the two-dimensional XY model is examined. The study includes disorder in the interaction among spins in the form of random phase shifts as well as disorder in the local orientation of the field. The phase diagrams are determined and the properties of the various phases and phase transitions are calculated. We use a renormalization group approach in the Coulomb gas representation of the model. Our results differ from those obtained for special cases in previous works. In particular, we find a changed topology of the phase diagram that is composed of phases with long-range order, quasi-long-range order, and short-range order. The discrepancies can be ascribed to a breakdown of the fugacity expansion in the Coulomb gas representation. Implications for physical systems such as planar Josephson junctions and the faceting of crystal surfaces are discussed.Comment: 17 pages Latex with 5 eps figures, change: acknowledgment extende

Feilke revisited : 60 Stellenbesuche

Weitere Hrsg.: Thorsten Pohl, Sara Rezat, Torsten Steinhoff, Martin SteinseiferAnlässlich des 60. Geburtstags des Linguisten und Sprachdidaktikers Helmuth Feilke wurden Wegbegleiterinnen und Wegbegleiter gebeten, einzelne Stellen in seinen wissenschaftlichen Schriften erneut zu besuchen. Entstanden sind pointierte Kommentare, kurze wissenschaftliche Abhandlungen und Analysen, Varianten auch des kritischen und kontroversen Nach- und Weiterdenkens und Ansätze zur Neu- oder Re-Kontextualisierung. Je nach wissenschaftlicher Vita der Autorinnen und Autoren kann es sich um Stellen handeln, deren Rezeption zeitlich weit zurückliegt, oder um Passagen, die ganz aktuelle Fragen der eigenen Forschungsarbeit tangieren. Abgesehen davon, dass ein kurzes Format für die Beiträge gewählt und die Autorinnen und Autoren gebeten wurden, die ausgewählte Stelle knapp zu verorten und zu erläutern, war die Bearbeitungsform gänzlich freigestellt. So sind Texte in einer Bandbreite von pointierten Kommentaren, kurzen wissenschaftlichen Abhandlungen und Analysen, Varianten des Nach- und Weiterdenkens, Ansätze zur Neu- oder Re-Kontextualisierung bis hin zu Formen des kritischen Hinterfragens und der kontroversen Auseinandersetzung entstanden

Untersuchungen der Plasmarandschichtstruktur im Tokamak TEXTOR-94 mittels der Heliumdiagnostik

The investigation of plasma-surface-interaction plays a significant role in high temperatureplasma research. The problem of energy and particle exhaust is of great importancefor a future fusion reactor. The knowledge about the plasma edge parameter is fundamentalfor the understanding of the relevant physical processes.The aim of the present work is to analyse the plasma edge structure in the tokamakTEXTOR-94 and to give a correlation between the edge parameters and the predefineddischarge parameters as well as to investigate the transport mechanisms in the plasmaedge. A comparison of the experimental findings with a one-dimensional analytic modeland the results of two-dimensional numerical calculations using the fluid-code TECXYshows the importance of drift motions and particle sources for the spatial distribution ofthe plasma edge parameters.Radial profiles of the electron density and temperature in the edge are obtained byspectroscopic observation of a thermal Helium beam injected at three different poloidalpositions: at both sides of the toroidal belt limiter, i.e. at the outer side and at thebottom of the circular plasma in TEXTOR-94, as well as on the inner side. Additionallya measurement of the poloidal ion velocity and temperature has been possible with thehelium beam diagnostic at the outer position by the use of charge exchange processes.The drift motions due to electrical fields and pressure gradients in the plasma edgehave strong influence on the radial and poloidal density distribution. Radial drifts lead toan increase respectively a decrease of the density gradients, depending on the drift orientation. Poloidal drifts change in a complex manner the parallel transport and thus lead toan asymmetric density distribution along the field lines. An increase of the heating poweror a decrease of the pitch angle of the magnetic field lines causes a higher asymmetry. Theexistance of two poloidal counter-rotating layers is proven by the velocity measurementsof C$^{6+}$. An inversion of the magnetic fields leads to an inversion of the drift motions andis therefore a tool to investigate the effects caused by the drifts. The measurements show,that the particle source distribution in the plasma edge has strong influence on the radialdensity profiles. In high density discharges a local maximum of the density is observed inthe vicinity of the main limiter due to the ionisation of neutral particles. The outboarddensity in such a discharge is twice as high as at the inner position. The measurementsof the radial decay length indicate, that the plasma edge of TEXTOR-94 is a region ofsignificant ionisation in high density discharges.The investigations presented here show, that drift motions and particle sources mustnot be neglected in the description of the plasma edge. This is especially true for theestimation of transport coefficients or the observation of local processes nearby the wallsurface