Bacterial susceptibility and resistance to modelin-5.

Modelin-5 (M5-NH ) killed with a minimum lethal concentration (MLC) of 5.86 μM and strongly bound its cytoplasmic membrane (CM) with a of 23.5 μM. The peptide adopted high levels of amphiphilic α-helical structure (75.0%) and penetrated the CM hydrophobic core (8.0 mN m ). This insertion destabilised CM structure increased lipid packing and decreased fluidity (Δ 0) and promoted only low levels of lysis (24.3%). The insertion and lysis of the CM by M5-NH showed a strong negative correlation with its lysyl phosphatidylglycerol (Lys-PG) content ( > 0.98). In combination, these data suggested that Lys-PG mediated mechanisms inhibited the membranolytic action of M5-NH against , thereby rendering the organism resistant to the peptide. These results are discussed in relation to structure/function relationships of M5-NH and CM lipids that underpin bacterial susceptibility and resistance to the peptide

The determination of the melting point, the vapor pressure, and the decomposition temperature of yttrium tri-iodide

Yttrium iodide was prepared by reacting yttrium metal turnings with ammonium iodide. The resulting salt was distilled into a melting point assembly and t he melting point and vapor pressure were determined by conventional techniques . Little decomposition of the iodide on a hot surface was observed under conditions that gave 100% decomposition of zirconium iodide

Entanglement, avoided crossings and quantum chaos in an Ising model with a tilted magnetic field

We study a one-dimensional Ising model with a magnetic field and show that tilting the field induces a transition to quantum chaos. We explore the stationary states of this Hamiltonian to show the intimate connection between entanglement and avoided crossings. In general entanglement gets exchanged between the states undergoing an avoided crossing with an overall enhancement of multipartite entanglement at the closest point of approach, simultaneously accompanied by diminishing two-body entanglement as measured by concurrence. We find that both for stationary as well as nonstationary states, nonintegrability leads to a destruction of two-body correlations and distributes entanglement more globally.Comment: Corrections in two figure captions and one new reference. To appear in Phys. Rev.

Gravitational Couplings of Intrinsic Spin

The gravitational couplings of intrinsic spin are briefly reviewed. A consequence of the Dirac equation in the exterior gravitational field of a rotating mass is considered in detail, namely, the difference in the energy of a spin-1/2 particle polarized vertically up and down near the surface of a rotating body is $\hbar\Omega\sin\theta$. Here $\theta$ is the latitude and $\Omega = 2GJ/(c^2 R^3)$, where $J$ and $R$ are, respectively, the angular momentum and radius of the body. It seems that this relativistic quantum gravitational effect could be measurable in the foreseeable future.Comment: LaTeX file, no figures, 16 page

Parallel transport in an entangled ring

This paper defines a notion of parallel transport in a lattice of quantum particles, such that the transformation associated with each link of the lattice is determined by the quantum state of the two particles joined by that link. We focus particularly on a one-dimensional lattice--a ring--of entangled rebits, which are binary quantum objects confined to a real state space. We consider states of the ring that maximize the correlation between nearest neighbors, and show that some correlation must be sacrificed in order to have non-trivial parallel transport around the ring. An analogy is made with lattice gauge theory, in which non-trivial parallel transport around closed loops is associated with a reduction in the probability of the field configuration. We discuss the possibility of extending our result to qubits and to higher dimensional lattices.Comment: 31 pages, no figures; v2 includes a new example of a qubit rin

Modelling the Galactic distribution of free electrons

In this paper we test 8 models of the free electron distribution in the Milky Way that have been published previously, and we introduce 4 additional models that explore the parameter space of possible models further. These new models consist of a simple exponential thick disk model, and updated versions of the models by Taylor & Cordes and Cordes & Lazio with more extended thick disks. The final model we introduce uses the observed H-alpha intensity as a proxy for the total electron column density, also known as the dispersion measure (DM). We use the latest available data sets of pulsars with accurate distances (through parallax measurements or association with globular clusters) to optimise the parameters in these models. In the process of fitting a new scale height for the thick disk in the model by Cordes & Lazio we discuss why this thick disk cannot be replaced by the thick disk that Gaensler et al. advocated in a recent paper. In the second part of our paper we test how well the different models can predict the DMs of these pulsars at known distances. Almost all models perform well, in that they predict DMs within a factor of 1.5-2 of the observed DMs for about 75% of the lines of sight. This is somewhat surprising since the models we tested range from very simple models that only contain a single exponential thick disk to very complex models like the model by Cordes & Lazio. We show that the model by Taylor & Cordes that we updated with a more extended thick disk consistently performs better than the other models we tested. Finally, we analyse which sightlines have DMs that prove difficult to predict by most models, which indicates the presence of local features in the ISM between us and the pulsar. (abridged)Comment: 16 pages, 10 figures, 5 tables. Accepted for publication in the Monthly Notices of the RAS by the Royal Astronomical Society and Blackwell Publishin

Experimental Investigation of the Secondary and Backscatter Electron Emission From New Spacecraft Surface Materials

The emission of secondary and backscattered electrons influences spacecraft surface potentials and the surrounding plasma. Modern spacecraft use new materials for which secondary emission properties have been unavailable. In this work, the total electron yield (i.e., the sum of secondary and backscattered electron yields) was measured for niobium-C103 alloy, molybdenum Titanium, Zirconium, Molybdenum (TZM) alloy, tantalum-tungsten alloy, Elgiloy®, graphite lubricant (DAG 213®), and titanium nitride. The surface properties of tungsten were also measured for comparison with past test data. The materials were readied as spacecraft flight materials and temperature-treated ( annealed ) to predicted peak flight temperatures. The yield properties for 10 eV-5 keV incident electron energies for all samples were measured. Both unannealed and annealed states were tested, except DAG 213, which was only tested annealed. Three-parameter and four-parameter models were used to fit the secondary and backscattered electron yield data, respectively. The emitted electron energy distributions are also obtained and fit with a Chung-Everhart model for secondary electrons and a Gaussian function for backscattered electrons. The secondary and backscattered electrons\u27 current densities were calculated for different ambient plasma conditions. For ready reference, the normalized primary electron, secondary electron, and backscattered electron current densities versus ambient electron temperature were computed and plotted from 1 eV to 8 keV

Monogamy of entanglement and other correlations

It has been observed by numerous authors that a quantum system being entangled with another one limits its possible entanglement with a third system: this has been dubbed the "monogamous nature of entanglement". In this paper we present a simple identity which captures the trade-off between entanglement and classical correlation, which can be used to derive rigorous monogamy relations. We also prove various other trade-offs of a monogamy nature for other entanglement measures and secret and total correlation measures.Comment: 7 pages, revtex

Effect of rejection on electrophysiologic function of canine intestinal grafts: Correlation with histopathology and na-k-ATPase activity

To investigate whether electrophysiologic changes can detect the early onset and progress of intestinal rejection, changes in in vitro electrophysiologic function, intestinal histopathology, and Na-K-ATPase activity were studied in dogs. Adult mongrel dogs of both sexes, weighing 18-24 kg, were used for auto and allo small bowel transplantation. The entire small bowels, except for short segments at the proximal and distal ends, were snitched between a pair of dogs (allograft). Animals receiving intestinal autotransplantation were used as controls. AIIograji recipients were sacrificed 3, 4, 5, 7, or 9 days after transplantation, and autograft recipients were sacrificed 3, 7, or 14 days afier transplantation. Immunosuppression was not used. Electrophysiologic measurements were done with an Ussing chamber. Histological analysis was performed blindly using whole thickness sections. Na-K-ATPase activity in the mucosal tissue, which is said to regulate the potential difference, was also measured. Potential difference, resistance, and Na-K-ATPase activity of the allografi intestine decreased with time and were significantly lower 7 and 9 days after transplantation compared to host intestine, normul intestine, and graft intestine of controls (autograft). Potential difference, resistance, and Na-K-ATPase activity of the native intestinal tissue and the autografts did not decrease with time. Detection of histologically mild rejection of the intestine, which is important for appropriate immunosup-pressive treatment in clinical cases, could not be achieved based on electrophysiology or Na-K-ATPase activity. Deterioration of electrophysiologic function during rejection correlated with the histological rejection process and Na-K-ATPase activity; however, electrophysiology my not be a reliable tool for monitoring grafrs, since it cannot detect early intestinal rejection. © 1995 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted