Impact of sorbic acid on germinant receptor-dependent and -independent germination pathways in Bacillus cereus

Amino acid- and inosine-induced germination of Bacillus cereus ATCC 14579 spores was reversibly inhibited in the presence of 3 mM undissociated sorbic acid. Exposure to high hydrostatic pressure, Ca-dipicolinic acid (DPA), and bryostatin, an activator of PrkC kinase, negated this inhibition, pointing to specific blockage of signal transduction in germinant receptor-mediated germination

Phase-resolved spectroscopy of the helium dwarf nova 'SN 2003aw' in quiescence

High time resolution spectroscopic observations of the ultracompact helium dwarf nova 'SN 2003aw' in its quiescent state at V similar to 20.5 reveal its orbital period at 2027.8 +/- 0.5 s or 33.80 min. Together with the photometric 'superhump' period of 2041.5 +/- 0.5 s, this implies a mass ratio q approximate to 0.036. We compare both the average and time-resolved spectra of 'SN 2003aw' and Sloan Digital Sky Survey (SDSS) J124058.03-015919.2. Both show a DB white dwarf spectrum plus an optically thin, helium-dominated accretion disc. 'SN 2003aw' distinguishes itself from the SDSS source by its strong calcium H & K emission lines, suggesting higher abundances of heavy metals than the SDSS source. The silicon and iron emission lines observed in the SDSS source are about twice as strong in 'SN 2003aw'. The peculiar 'double bright spot' accretion disc feature seen in the SDSS source is also present in time-resolved spectra of 'SN 2003aw', albeit much weaker

Asymmetric gate induced drain leakage and body leakage in vertical MOSFETs with reduced parasitic capacitance

Vertical MOSFETs, unlike conventional planar MOSFETs, do not have identical structures at the source and drain, but have very different gate overlaps and geometric configurations. This paper investigates the effect of the asymmetric source and drain geometries of surround-gate vertical MOSFETs on the drain leakage currents in the OFF-state region of operation. Measurements of gate-induced drain leakage (GIDL) and body leakage are carried out as a function of temperature for transistors connected in the drain-on-top and drain-on-bottom configurations. Asymmetric leakage currents are seen when the source and drain terminals are interchanged, with the GIDL being higher in the drain-on-bottom configuration and the body leakage being higher in the drain-on-top configuration. Band-to-band tunneling is identified as the dominant leakage mechanism for both the GIDL and body leakage from electrical measurements at temperatures ranging from ?50 to 200?C. The asymmetric body leakage is explained by a difference in body doping concentration at the top and bottom drain–body junctions due to the use of a p-well ion implantation. The asymmetric GIDL is explained by the difference in gate oxide thickness on the vertical (110) pillar sidewalls and the horizontal (100) wafer surface

Construction and analysis of anomaly-free supersymmetric SO(2N)/U(N) sigma-models

This paper discusses a procedure for the consistent coupling of gauge- and matter superfields to supersymmetric sigma-models on symmetric coset spaces of Kaehler type. We exhibit the finite isometry transformations and the corresponding Kaehler transformations. These lead to the construction of a generalized type of Killing potentials. In certain cases a charge quantization condition needs to be imposed to guarantee the global existence of a line bundle on a coset space. The results are applied to the explicit construction of sigma-models on cosets SO(2N)/U(N). Only a finite number of these models can consistently incorporate matter in representations descending from the spinorial representations of SO(2N). We investigate in detail some aspects of the vacuum structure of the gauged SO(10)/U(5) theory, with surprising results: the fully gauged minimal anomaly-free model is shown be singular, as the kinetic terms of the quasi-Goldstone fermions vanish in the vacuum. Gauging only the linear isometry group SU(5)xU(1), or one of its subgroups, can give a physically well-behaved theory. With gauged U(1) this requires the Fayet-Iliopoulos term to take values in a specific limited range.Comment: 40 pages, LaTeX, no figure

Second order equation of motion for electromagnetic radiation back-reaction

We take the viewpoint that the physically acceptable solutions of the Lorentz--Dirac equation for radiation back-reaction are actually determined by a second order equation of motion, the self-force being given as a function of spacetime location and velocity. We propose three different methods to obtain this self-force function. For two example systems, we determine the second order equation of motion exactly in the nonrelativistic regime via each of these three methods, the three methods leading to the same result. We reveal that, for both systems considered, back-reaction induces a damping proportional to velocity and, in addition, it decreases the effect of the external force.Comment: 13 page

Analysis of magnetoresistance in arrays of connected nano-rings

We study the anisotropic magnetoresistance (AME) of a 2D periodic square array of connected permalloy rings with periodicity of 1m combining experimental and computational techniques. The computational models consists of two parts: 1) the computation of the magnetization and 2) the computation of the current density. For 1), we use standard micromagnetic methods. For 2), we start from a potential difference applied across the sample, compute the resulting electric potential , and subsequently the corresponding current density based on a uniform conductiviy. We take into account the backreaction of the magnetoresistive effects onto the current density by self-consistently computing the current density and conductivity until they converge. We compare the experimentally measured AMR insight into the characteristics of the AMR data. Finally, we demonstrate the importance of taking into account the spatial variation of the current density when computing the AMR