Atomic Simulation Interface (ASI) : application programming interface for electronic structure codes

The Atomic Simulation Interface (ASI) is a native C-style API for density functional theory (DFT) codes. ASI provides an efficient way to import and export large arrays that describe electronic structure (e.g. Hamiltonian, overlap, and density matrices) from DFT codes that are typically monolithic. The ASI API is designed to be implemented and used with minimal performance penalty, avoiding, where possible, unnecessary data copying. It provides direct access to the internal data structures of a code, and reuses existing data distribution over MPI nodes. The ASI API also defines a set of functions that support classical, AIMD (ab initio molecular dynamics), and hybrid QM/MM simulations: exporting potential energy, forces, atomic charges, and electrostatic potential at user defined points, as well as importing nuclear coordinates and arbitrary external electrostatic potentials. The ASI API is implemented in the DFTB+ (Hourahine et al., 2020) and FHI-aims (Blum et al., 2009) codes. A Python wrapper for easy access to ASI functions is also freely available (asi4py). We hope that the ASI API will be widely adopted and used for development of universal and interoperable DFT codes without sacrificing efficiency for portability

Performance Assessment of Bi-Directional Knotless Tissue-Closure Device in Juvenile Chinook Salmon Surgically Implanted with Acoustic Transmitters, 2010 - Final Report

In 2010, researchers at Pacific Northwest National Laboratory (PNNL) and the University of Washington (UW) conducted a compliance monitoring study—the Lower Columbia River Acoustic Transmitter Investigations of Dam Passage Survival and Associated Metrics 2010 (Carlson et al. in preparation)—for the U.S. Army Corps of Engineers (USACE), Portland District. The purpose of the compliance study was to evaluate juvenile Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss) passage routes and survival through the lower three Columbia River hydroelectric facilities as stipulated by the 2008 Federal Columbia River Power System (FCRPS) Biological Opinion (BiOp; NOAA Fisheries 2008) and the Columbia Basin Fish Accords (Fish Accords; 3 Treaty Tribes and Action Agencies 2008)

The M33 Globular Cluster System with PAndAS Data: The Last Outer Halo Cluster?

We use CFHT/MegaCam data to search for outer halo star clusters in M33 as part of the Pan-Andromeda Archaeological Survey (PAndAS). This work extends previous studies out to a projected radius of 50 kpc and covers over 40 square degrees. We find only one new unambiguous star cluster in addition to the five previously known in the M33 outer halo (10 kpc <= r <= 50 kpc). Although we identify 2440 cluster candidates of various degrees of confidence from our objective image search procedure, almost all of these are likely background contaminants, mostly faint unresolved galaxies. We measure the luminosity, color and structural parameters of the new cluster in addition to the five previously-known outer halo clusters. At a projected radius of 22 kpc, the new cluster is slightly smaller, fainter and redder than all but one of the other outer halo clusters, and has g' ~ 19.9, (g'-i') ~ 0.6, concentration parameter c ~ 1.0, a core radius r_c ~ 3.5 pc, and a half-light radius r_h ~ 5.5 pc. For M33 to have so few outer halo clusters compared to M31 suggests either tidal stripping of M33's outer halo clusters by M31, or a very different, much calmer accretion history of M33.Comment: 37 pages, 9 figures. Accepted by the Astrophysical Journa

Real and virtual polymorphism of titanium selenide with robust interatomic potentials

The first successful pairwise potential for a layered material, TiSe2, has been parameterised to fit the experimental data, using a genetic algorithm as the optimisation tool for the parameters of the interatomic potential. This potential has been tested on a wide range of hypothetical isomorphous AX2 metastable phases using ab initio derived data. From the initial survey, the ground state 1T–TiSe2 structure remains the lowest enthalpy phase in a wide range of pressures (0 to 25 GPa), which leaves open questions about the nature of a reported unknown high-pressure phase

Multiscale QM/MM modelling of catalytic systems with ChemShell

Hybrid quantum mechanical/molecular mechanical (QM/MM) methods are a powerful computational tool for the investigation of all forms of catalysis, as they allow for an accurate description of reactions occurring at catalytic sites in the context of a complicated electrostatic environment. The scriptable computational chemistry environment ChemShell is a leading software package for QM/MM calculations, providing a flexible, high performance framework for modelling both biomolecular and materials catalysis. We present an overview of recent applications of ChemShell to problems in catalysis and review new functionality introduced into the redeveloped Python-based version of ChemShell to support catalytic modelling. These include a fully guided workflow for biomolecular QM/MM modelling, starting from an experimental structure, a periodic QM/MM embedding scheme to support modelling of metallic materials, and a comprehensive set of tutorials for biomolecular and materials modelling

The Changing Profile of Full-Time Faculty at Canadian Universities

Canadian universities underwent a remarkable expansion from the late sixties until the mid-seventies. However, they are entering the eighties on an uncertain note, due to financial restraints imposed by governments, the sudden growth in university enrolment and the shift to professionally oriented programs. These developments have had an impact on the socio-economic characteristics of the 33,000 full-time university teachers: their age, sex, academic rank, salary, citizenship, and qualifications. Especially uncertain is the demand for new faculty in this decade and the implications for the health of Canadian universities. This statistical series documents the changes which are occurring in the demand and supply patterns of doctoral recipients from Canadian universities with the purpose of providing a statistical base from which policy analyses could be developed.Les universités canadiennes ont subi au cours des années 1960/mi-1970 un épanouissement remarquable. Cependant, elles se voient entrer dans une période d'incertitude au début des années 1980 due aux contraintes financières imposées par les gouvernements, l'accroissement soudain de l'inscription au niveau univer-sitaire, et au déplacement vers les programmes de métier. Ces développements ont eu un impact sur les caractéristiques socio-économiques des quelques 33,000 professeurs engagés à plein temps soit l'âge, le sexe, le rang académique, le salaire, la citoyenneté et les qualifications. Comme la demande de professeurs est res-treinte dans cette décade, le fonctionnement des universités canadiennes en est affecté. Les différentes statistiques présentent les changements qui surviennent face aux modèles d'offre et de demande chez les détenteurs de doctorats d'univer-sités canadiennes. Cette documentation a pour but de fournir une ligne de con-duite qui servira au développement de nouvelles politiques

Mosaic: A Satellite Constellation to Enable Groundbreaking Mars Climate System Science and Prepare for Human Exploration

The Martian climate system has been revealed to rival the complexity of Earth\u27s. Over the last 20 yr, a fragmented and incomplete picture has emerged of its structure and variability; we remain largely ignorant of many of the physical processes driving matter and energy flow between and within Mars\u27 diverse climate domains. Mars Orbiters for Surface, Atmosphere, and Ionosphere Connections (MOSAIC) is a constellation of ten platforms focused on understanding these climate connections, with orbits and instruments tailored to observe the Martian climate system from three complementary perspectives. First, low-circular near-polar Sun-synchronous orbits (a large mothership and three smallsats spaced in local time) enable vertical profiling of wind, aerosols, water, and temperature, as well as mapping of surface and subsurface ice. Second, elliptical orbits sampling all of Mars\u27 plasma regions enable multipoint measurements necessary to understand mass/energy transport and ion-driven escape, also enabling, with the polar orbiters, dense radio occultation coverage. Last, longitudinally spaced areostationary orbits enable synoptic views of the lower atmosphere necessary to understand global and mesoscale dynamics, global views of the hydrogen and oxygen exospheres, and upstream measurements of space weather conditions. MOSAIC will characterize climate system variability diurnally and seasonally, on meso-, regional, and global scales, targeting the shallow subsurface all the way out to the solar wind, making many first-of-their-kind measurements. Importantly, these measurements will also prepare for human exploration and habitation of Mars by providing water resource prospecting, operational forecasting of dust and radiation hazards, and ionospheric communication/positioning disruptions

The SLUGGS survey: probing the supermassive blackhole connection with bulges and haloes using red and blue globular cluster systems

Understanding whether the bulge or the halo provides the primary link to the growth of supermassive black holes has strong implications for galaxy evolution and supermassive black hole formation itself. In this paper, we approach this issue by investigating extragalactic globular cluster (GC) systems, which can be used to probe the physics of both the bulge and the halo of the host galaxy. We study the relation between the supermassive black hole masses (MBH) and the GC system velocity dispersions (σGC) using an updated and improved sample of 21 galaxies. We exploit the dichotomy of GC system colours, to test if the blue and red GCs correlate differently with black hole mass. This may be expected if they trace the potentially different formation history of the halo and of the bulge of the host galaxy, respectively. We find that MBH correlates with the total GC system velocity dispersion, although not as strongly as claimed by recent work of Sadoun & Colin. We also examine the MBH-σGC relation for barred/barless and core/non-core galaxies, finding no significant difference, and for the first time we quantify the impact of radial gradients in the GC system velocity dispersion profile on the MBH-σGC relation. We additionally predict MBH in 13 galaxies, including dwarf elliptical galaxies and the cD galaxy NGC 3311. We conclude that our current results cannot discriminate between the bulge/halo scenarios. Although there is a hint that the red GC velocity dispersion might correlate better with MBH than the blue GC velocity dispersion, the number statistics are still too low to be certain

Efficacy of customised foot orthoses in the treatment of achilles tendinopathy : study protocol for a randomised trial

BACKGROUND: Achilles tendinopathy is a common condition that can cause marked pain and disability. Numerous non-surgical treatments have been proposed for the treatment of this condition, but many of these treatments have a poor or non-existent evidence base. The exception to this is eccentric calf muscle exercises, which have become a standard non-surgical intervention for Achilles tendinopathy. Foot orthoses have also been advocated as a treatment for Achilles tendinopathy, but the long-term efficacy of foot orthoses for this condition is unknown. This manuscript describes the design of a randomised trial to evaluate the efficacy of customised foot orthoses to reduce pain and improve function in people with Achilles tendinopathy. METHODS: One hundred and forty community-dwelling men and women aged 18 to 55 years with Achilles tendinopathy (who satisfy inclusion and exclusion criteria) will be recruited. Participants will be randomised, using a computer-generated random number sequence, to either a control group (sham foot orthoses made from compressible ethylene vinyl acetate foam) or an experimental group (customised foot orthoses made from semi-rigid polypropylene). Both groups will be prescribed a calf muscle eccentric exercise program, however, the primary difference between the groups will be that the experimental group receive customised foot orthoses, while the control group receive sham foot orthoses. The participants will be instructed to perform eccentric exercises 2 times per day, 7 days per week, for 12 weeks. The primary outcome measure will be the total score of the Victorian Institute of Sport Assessment - Achilles (VISA-A) questionnaire. The secondary outcome measures will be participant perception of treatment effect, comfort of the foot orthoses, use of co-interventions, frequency and severity of adverse events, level of physical activity and health-related quality of life (assessed using the Short-Form-36 questionnaire - Version two). Data will be collected at baseline, then at 1, 3, 6 and 12 months. Data will be analysed using the intention to treat principle. DISCUSSION: This study is the first randomised trial to evaluate the long-term efficacy of customised foot orthoses for the treatment of Achilles tendinopathy. The study has been pragmatically designed to ensure that the study findings are generalisable to clinical practice. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry Number: ACTRN12609000829213