A post-Newtonian diagnosis of quasiequilibrium configurations of neutron star-neutron star and neutron star-black hole binaries

We use a post-Newtonian diagnostic tool to examine numerically generated quasiequilibrium initial data sets for non-spinning double neutron star and neutron star-black hole binary systems. The PN equations include the effects of tidal interactions, parametrized by the compactness of the neutron stars and by suitable values of ``apsidal'' constants, which measure the degree of distortion of stars subjected to tidal forces. We find that the post-Newtonian diagnostic agrees well with the double neutron star initial data, typically to better than half a percent except where tidal distortions are becoming extreme. We show that the differences could be interpreted as representing small residual eccentricity in the initial orbits. In comparing the diagnostic with preliminary numerical data on neutron star-black hole binaries, we find less agreement.Comment: 17 pages, 6 tables, 8 figure

Supporting Primary Health Care Providers in Western Sydney areas of socioeconomic disadvantage

General Practitioners working with socially disadvantaged populations face challenges in trying to solve complex health issues and social problems, often in time pressured visits. Western Sydney includes some of the most disadvantaged postcodes in Australia and has some of the highest rates of disease prevalence as well as lowest GP to population ratios. This project is describing the needs of primary health care providers (PHCPs) in these areas, to develop a support model and to evaluate early implementation of this model in order to inform funding bids for ongoing research and support. The longer term aim is to build sustainability of the primary care workforce in order to improve health outcomes and inform the Australian health reform agenda particularly regarding workforce shortages in outer urban disadvantaged areas.The research reported in this paper is a project of the Australian Primary Health Care Research Institute which is supported by a grant from the Australian Government Department of Health and Ageing under the Primary Health Care Research Evaluation and Development Strategy

Anisotropic Susceptibility of La_2-xSr_xCoO_4 related to the Spin States of Cobalt

We present a study of the magnetic susceptibility of La_2-xSr_xCoO_4 single crystals in a doping range 0.3<=x<=0.8. Our data shows a pronounced magnetic anisotropy for all compounds. This anisotropy is in agreement with a low-spin ground state (S=0) of Co^3+ for x>=0.4 and a high-spin ground state (S=3/2) of Co^2+. We compare our data with a crystal-field model calculation assuming local moments and find a good description of the magnetic behavior for x>=0.5. This includes the pronounced kinks observed in the inverse magnetic susceptibility, which result from the anisotropy and low-energy excited states of Co^2+ and are not related to magnetic ordering or temperature-dependent spin-state transitions

Synthetic soil crusts against green-desert transitions : a spatial model

Altres ajuts: Botin Foundation (Banco Santander through its Santander Universities Global Division) i CERCA Programme/Generalitat de CatalunyaSemiarid ecosystems are threatened by global warming due to longer dehydration times and increasing soil degradation. Mounting evidence indicates that, given the current trends, drylands are likely to expand and possibly experience catastrophic shifts from vegetated to desert states. Here, we explore a recent suggestion based on the concept of ecosystem terraformation, where a synthetic organism is used to counterbalance some of the nonlinear effects causing the presence of such tipping points. Using an explicit spatial model incorporating facilitation and considering a simplification of states found in semiarid ecosystems including vegetation, fertile and desert soil, we investigate how engineered microorganisms can shape the fate of these ecosystems. Specifically, two different, but complementary, terraformation strategies are proposed: Cooperation -based: C -terraformation; and Dispersion -based: D -terraformation. The first strategy involves the use of soil synthetic microorganisms to introduce cooperative loops (facilitation) with the vegetation. The second one involves the introduction of engineered microorganisms improving their dispersal capacity, thus facilitating the transition from desert to fertile soil. We show that small modifications enhancing cooperative loops can effectively modify the aridity level of the critical transition found at increasing soil degradation rates, also identifying a stronger protection against soil degradation by using the D -terraformation strategy. The same results are found in a mean-field model providing insights into the transitions and dynamics tied to these terraformation strategies. The potential consequences and extensions of these models are discussed

The person, interactions and environment programme to improve care of people with dementia in hospital: a multisite study

Background: Improving care of people with dementia on acute hospital wards is a policy priority. Person-centred care is a marker of care quality; delivering such care is a goal for service improvement. Objectives: PIE (Person: Interaction; Environment) comprises an observation tool and systematic approach to implement and embed a person-centred approach in routine care for hospitalised patients with dementia. The study aims were to: evaluate PIE as a method to improve the care of older people with dementia on acute hospital wards; and develop insight into what person-centred care might look like in practice in this setting. Methods: We performed a longitudinal comparative case study design in ten purposively selected wards in five Trusts in three English regions; alongside an embedded process evaluation. Data was collected from multiple sources: staff, patients, relatives, organisational aggregate information and documents. Mixed methods were employed: ethnographic observation; interviews and questionnaires; patient case studies (patient observation and conversations ‘in the moment’, interviews with relatives and case records), patient and ward aggregate data. Data was synthesised to create individual case studies of PIE implementation and outcomes in context of ward structure, organisation, patient profile and process of care delivery. Cross case comparison facilitated a descriptive and explanatory account of PIE implementation in context, the pattern of variation, what shaped it and the consequences flowing from it. Quantitative data was analysed using simple descriptive statistics. Qualitative data analysis employed grounded theory methods. Results: The study furthered understanding of dimensions of care quality for older people with dementia on acute hospital wards and the environmental, organisational and cultural factors that shaped delivery. Only two wards fully implemented PIE, sustaining and embedding change over 18 months. The remaining wards either did not install PIE (‘non-implementers’); or were ‘partial implementers’. The interaction between micro-level contextual factors (aspects of leadership (drivers, facilitators, team, networks), fit with strategic initiatives and salience with valued goals) and miso and macro level organisational factors, were the main barriers to PIE adoption. Where implemented, evidence suggests that the programme directly affected improvement in ward practice with positive impact on the experience of patients and caregivers, although the heterogeneity of need and severity of impairment meant that some of the more visible changes did not affect everyone equally. Limitations: Although PIE has potential to improve the care of people with dementia when implemented, findings are indicative only: data on clinical outcomes was not systematically collected; and PIE was not adopted on most study wards. Research implications: Further research is required to identify more precisely the skill-mix and resources necessary to provide person-focused care to hospitalised people with dementia, across the spectrum of need, including those with moderate and severe impairment. Implementing innovations to change practices in complex organisations requires more in-depth understanding of contextual factors that impact the capacity of organisations to absorb and embed new practices

Discrete organic phosphorus signatures are evident in pollutant sources within a Lake Erie tributary

Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Environmental Science and Technology 52 (2018): 6771-6779, doi:10.1021/acs.est.7b05703.Phosphorus loads are strongly associated with the severity of harmful algal blooms in Lake Erie, a Great Lake situated between the United States and Canada. Inorganic and total phosphorus measurements have historically been used to estimate nonpoint and point source contributions, from contributing watersheds with organic phosphorus often neglected. Here, we used ultrahigh resolution mass spectrometry to characterize the dissolved organic matter and specifically dissolved organic phosphorus composition of several nutrient pollutant source materials and aqueous samples in a Lake Erie tributary. We detected between 23-313 organic phosphorus formulae across our samples, with manure samples having greater abundance of phosphorus- and nitrogen containing compounds compared to other samples. Manures also were enriched in lipids and protein-like compounds. The greatest similarities were observed between the Sandusky River and wastewater treatment plant effluent (WWTP), or the Sandusky River and agricultural edge of field samples. These sample pairs shared 84% of organic compounds and 59 to 73% of P-containing organic compounds, respectively. This similarity suggests that agricultural and/or WWTP sources dominate the supply of organic phosphorus compounds to the river. We identify formulae shared between the river and pollutant sources that could serve as possible markers of source contamination in the tributary.This research was supported by an Ohio State University Field to Faucet Institute award to P.J.M and by a Harmful Algal Bloom Research Initiative grant from the Ohio Department of Higher Education

Atom laser dynamics in a tight-waveguide

We study the transient dynamics that arise during the formation of an atom laser beam in a tight waveguide. During the time evolution the density profile develops a series of wiggles which are related to the diffraction in time phenomenon. The apodization of matter waves, which relies on the use of smooth aperture functions, allows to suppress such oscillations in a time interval, after which there is a revival of the diffraction in time. The revival time scale is directly related to the inverse of the harmonic trap frequency for the atom reservoir.Comment: 6 pages, 5 figures, to be published in the Proceedings of the 395th WE-Heraeus Seminar on "Time Dependent Phenomena in Quantum Mechanics ", organized by T. Kramer and M. Kleber (Blaubeuren, Germany, September 2007