Active control of spacecraft charging on ATS-5 and ATS-6

Effects on spacecraft ground potential of active emission of charged particles are being investigated through experiments using the ATS-5 and ATS-6 spacecraft. Each spacecraft is equipped with ion engine neutralizers which emit low energy charged particles. Despite great differences in design between the two spacecraft, they attain similar potentials in similar environments. Therefore, effects on spacecraft potential of neutralizer operations can be used to compare the effects of operating the two different neutralizers (hot wire filament and plasma bridge). The neutralizers on both spacecraft were operated in eclipse. Results of these operations are presented and spacecraft responses compared

On Immunity From Infectious Disease.

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Clann: investigating phylogenetic information through supertree analyses

Summary: Clann has been developed in order to provide methods of investigating phylogenetic information through the application of supertrees. Availability: Clann has been precompiled for Linux, Apple Macintosh and Windows operating systems and is available from http://bioinf.may.ie/software/clann. Source code is available on request from the authors. Supplementary information: Clann has been written in the C programming language. Source code is available on request

A Behavioral Change Intervention System to Support the Hydration Habits of Nurses in Hospital Wards

Copyright © 2020 by the authors. This paper reports on the design and development of a Behavior Change Intervention (BCI) device and service provision aimed at supporting the personal hydration habits of NHS ward based nurses. A conceptual solution is proposed that has been developed using an iterative design process, following an adapted version of the double-diamond approach, over a seven-month time period from 11 October 2019 – 13 May 2020. The research was completed in collaboration with the Guy’s and St Thomas’ NHS Foundation Trust, United Kingdom. A thematic review of related literature was completed to identify key research questions. Consultation with a senior long-serving NHS nurse and a real-time observation study was completed in an NHS ward to answer these questions within the research scope. Collected data was analyzed and insights into the behaviors of nurses and the contextual factors influencing them, were provided. Re-usable BCI devices and a habit formation program, incorporating a smart fob watch and water station, is proposed inside of a cradle-to-cradle system. Finally, the parameters of the developed solution are defined, and the device and user experience are visualized using computer renders and storyboards. Aspects of the device functionality and feasibility have been proven and visualized using graphic devices, and their use for data collection to inform healthcare management and improvements is discussed

Radiation transport and scaling of optical depth in Nd:YAG laser-produced microdroplet-tin plasma

Experimental scaling relations of the optical depth are presented for the emission spectra of a tin-droplet-based, 1-μm-laser-produced plasma source of extreme-ultraviolet (EUV) light. The observed changes in the complex spectral emission of the plasma over a wide range of droplet diameters (16-65 μm) and laser pulse durations (5-25 ns) are accurately captured in a scaling relation featuring the optical depth of the plasma as a single, pertinent parameter. The scans were performed at a constant laser intensity of 1.4 × 1011 W/cm2, which maximizes the emission in a 2% bandwidth around 13.5 nm relative to the total spectral energy, the bandwidth relevant for industrial EUV lithography. Using a one-dimensional radiation transport model, the relative optical depth of the plasma is found to linearly increase with the droplet size with a slope that increases with the laser pulse duration. For small droplets and short laser pulses, the fraction of light emitted in the 2% bandwidth around 13.5 nm relative to the total spectral energy is shown to reach high values of more than 14%, which may enable conversion efficiencies of Nd:YAG laser light into - industrially - useful EUV radiation rivaling those of current state-of-the-art CO2-laser-driven sources

Cohesive properties of alkali halides

We calculate cohesive properties of LiF, NaF, KF, LiCl, NaCl, and KCl with ab-initio quantum chemical methods. The coupled-cluster approach is used to correct the Hartree-Fock crystal results for correlations and to systematically improve cohesive energies, lattice constants and bulk moduli. After inclusion of correlations, we recover 95-98 % of the total cohesive energies. The lattice constants deviate from experiment by at most 1.1 %, bulk moduli by at most 8 %. We also find good agreement for spectroscopic properties of the corresponding diatomic molecules.Comment: LaTeX, 10 pages, 1 figure, accepted by Phys. Rev.

Transfer Functions for Protein Signal Transduction: Application to a Model of Striatal Neural Plasticity

We present a novel formulation for biochemical reaction networks in the context of signal transduction. The model consists of input-output transfer functions, which are derived from differential equations, using stable equilibria. We select a set of 'source' species, which receive input signals. Signals are transmitted to all other species in the system (the 'target' species) with a specific delay and transmission strength. The delay is computed as the maximal reaction time until a stable equilibrium for the target species is reached, in the context of all other reactions in the system. The transmission strength is the concentration change of the target species. The computed input-output transfer functions can be stored in a matrix, fitted with parameters, and recalled to build discrete dynamical models. By separating reaction time and concentration we can greatly simplify the model, circumventing typical problems of complex dynamical systems. The transfer function transformation can be applied to mass-action kinetic models of signal transduction. The paper shows that this approach yields significant insight, while remaining an executable dynamical model for signal transduction. In particular we can deconstruct the complex system into local transfer functions between individual species. As an example, we examine modularity and signal integration using a published model of striatal neural plasticity. The modules that emerge correspond to a known biological distinction between calcium-dependent and cAMP-dependent pathways. We also found that overall interconnectedness depends on the magnitude of input, with high connectivity at low input and less connectivity at moderate to high input. This general result, which directly follows from the properties of individual transfer functions, contradicts notions of ubiquitous complexity by showing input-dependent signal transmission inactivation.Comment: 13 pages, 5 tables, 15 figure

Correlation effects in MgO and CaO: Cohesive energies and lattice constants

A recently proposed computational scheme based on local increments has been applied to the calculation of correlation contributions to the cohesive energy of the CaO crystal. Using ab-initio quantum chemical methods for evaluating individual increments, we obtain 80% of the difference between the experimental and Hartree-Fock cohesive energies. Lattice constants corrected for correlation effects deviate by less than 1% from experimental values, in the case of MgO and CaO.Comment: LaTeX, 4 figure