226 research outputs found

    Improving techniques for the WaxTagÂź possum (Trichosurus vulpecula) monitoring index

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    To manage brushtail possums (Trichosurus vulpecula) accurate estimates of abundance are essential. Direct counts are not feasible for large populations and index techniques are normally employed. A new index technique for estimating possum abundance is the WaxTag¼. They are potentially more effective than traps because they are small, easier to use, very lightweight and, therefore, higher numbers can be set out in the field. Whilst a national monitoring protocol for WaxTag¼s has been developed, it is important to determine whether improvements can be made. This study investigated firstly whether luminescent-coloured WaxTag¼s were more attractive than the WaxTag¼ with a ‘flour blaze’ and, secondly, whether raising the WaxTag¼s 700 mm above the ground reduced detectability. Possums significantly preferred the flour blaze over luminescence and raising WaxTag¼s did not significantly reduce detectability. Accordingly, WaxTag¼s could be raised up above ground-dwelling non-target species without reducing statistical precision

    Hydrodynamical Non-radiative Accretion Flows in Two-Dimensions

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    Two-dimensional (axially symmetric) numerical hydrodynamical calculations of accretion flows which cannot cool through emission of radiation are presented. The calculations begin from an equilibrium configuration consisting of a thick torus with constant specific angular momentum. Accretion is induced by the addition of a small anomalous azimuthal shear stress which is characterized by a function \nu. We study the flows generated as the amplitude and form of \nu are varied. A spherical polar grid which spans more than two orders of magnitude in radius is used to resolve the flow over a wide range of spatial scales. We find that convection in the inner regions produces significant outward mass motions that carry away both the energy liberated by, and a large fraction of the mass participating in, the accretion flow. Although the instantaneous structure of the flow is complex and dominated by convective eddies, long time averages of the dynamical variables show remarkable correspondence to certain steady-state solutions. Near the equatorial plane, the radial profiles of the time-averaged variables are power-laws with an index that depends on the radial scaling of the shear stress. We find that regardless of the adiabatic index of the gas, or the form or magnitude of the shear stress, the mass inflow rate is a strongly increasing function of radius, and is everywhere nearly exactly balanced by mass outflow. The net mass accretion rate through the disc is only a fraction of the rate at which mass is supplied to the inflow at large radii, and is given by the local, viscous accretion rate associated with the flow properties near the central object.Comment: 33 pages, 12 figures, accepted by MNRA

    Pinpointing needles in giant haystacks: use of text mining to reduce impractical screening workload in extremely large scoping reviews.

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    In scoping reviews, boundaries of relevant evidence may be initially fuzzy, with refined conceptual understanding of interventions and their proposed mechanisms of action an intended output of the scoping process rather than its starting point. Electronic searches are therefore sensitive, often retrieving very large record sets that are impractical to screen in their entirety. This paper describes methods for applying and evaluating the use of text mining (TM) technologies to reduce impractical screening workload in reviews, using examples of two extremely large-scale scoping reviews of public health evidence (choice architecture (CA) and economic environment (EE)). Electronic searches retrieved >800,000 (CA) and >1 million (EE) records. TM technologies were used to prioritise records for manual screening. TM performance was measured prospectively. TM reduced manual screening workload by 90% (CA) and 88% (EE) compared with conventional screening (absolute reductions of ≈430 000 (CA) and ≈378 000 (EE) records). This study expands an emerging corpus of empirical evidence for the use of TM to expedite study selection in reviews. By reducing screening workload to manageable levels, TM made it possible to assemble and configure large, complex evidence bases that crossed research discipline boundaries. These methods are transferable to other scoping and systematic reviews incorporating conceptual development or explanatory dimensions

    First-Line First? Trends in Thiazide Prescribing for Hypertensive Seniors

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    BACKGROUND: Evidence of reduced cardiovascular morbidity and mortality as well as cost support thiazide diuretics as the first-line choice for treatment of hypertension. The purpose of this study was to determine the proportion of senior hypertensives that received thiazide diuretics as first-line treatment, and to determine if cardiovascular and other potentially relevant comorbidities predict the choice of first-line therapy. METHODS AND FINDINGS: British Columbia PharmaCare data were used to determine the cohort of seniors (residents aged 65 or older) who received their first reimbursed hypertension drug during the period 1993 to 2000. These individual records were linked to medical and hospital claims data using the British Columbia Linked Health Database to find the subset that had diagnoses indicating the presence of hypertension as well as cardiovascular and other relevant comorbidities. Rates of first-line thiazide prescribing as proportion of all first-line treatment were analysed, accounting for patient age, sex, overall clinical complexity, and potentially relevant comorbidities. For the period 1993 to 2000, 82,824 seniors who had diagnoses of hypertension were identified as new users of hypertension drugs. The overall rate at which thiazides were used as first-line treatment varied from 38% among senior hypertensives without any potentially relevant comorbidity to 9% among hypertensives with previous acute myocardial infarction. The rate of first-line thiazide diuretic prescribing for patients with and without potentially relevant comorbidities increased over the study period. Women were more likely than men, and older patients were more likely than younger, to receive first-line thiazide therapy. CONCLUSIONS: Findings indicate that first-line prescribing practices for hypertension are not consistent with the evidence from randomized control trials measuring morbidity and mortality. The health and financial cost of not selecting the most effective and least costly therapeutic options are significant

    Accretion of Planetary Material onto Host Stars

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    Accretion of planetary material onto host stars may occur throughout a star's life. Especially prone to accretion, extrasolar planets in short-period orbits, while relatively rare, constitute a significant fraction of the known population, and these planets are subject to dynamical and atmospheric influences that can drive significant mass loss. Theoretical models frame expectations regarding the rates and extent of this planetary accretion. For instance, tidal interactions between planets and stars may drive complete orbital decay during the main sequence. Many planets that survive their stars' main sequence lifetime will still be engulfed when the host stars become red giant stars. There is some observational evidence supporting these predictions, such as a dearth of close-in planets around fast stellar rotators, which is consistent with tidal spin-up and planet accretion. There remains no clear chemical evidence for pollution of the atmospheres of main sequence or red giant stars by planetary materials, but a wealth of evidence points to active accretion by white dwarfs. In this article, we review the current understanding of accretion of planetary material, from the pre- to the post-main sequence and beyond. The review begins with the astrophysical framework for that process and then considers accretion during various phases of a host star's life, during which the details of accretion vary, and the observational evidence for accretion during these phases.Comment: 18 pages, 5 figures (with some redacted), invited revie

    Ion kinetic properties in Mercury's pre-midnight plasma sheet

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    With data from the Fast Imaging Plasma Spectrometer sensor on the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft, we demonstrate that the average distributions for both solar wind and planetary ions in Mercury’s pre-midnight plasma sheet are well-described by hot Maxwell-Boltzmann distributions. Temperatures and densities of the H+ ranges ~1–10 cm3 and ~5–30 MK, respectively, maintain thermal pressures of ~1 nPa. The dominant planetary ion, Na+ abundances with respect to H+ and exhibit mass-proportional ion temperatures, indicative of a reconnection-dominated heating in the magnetosphere. Conversely, planetary ion species are accelerated to similar average energies greater by a factor of ~1.5 than that of H+ acceleration in an electric potential, consistent with the presence of a strong centrifugal acceleration process in Mercury’s magnetosphere

    Is there a role for workplaces in reducing employees' driving to work? Findings from a cross-sectional survey from inner-west Sydney, Australia

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    <p>Abstract</p> <p>Background</p> <p>The role of workplaces in promoting active travel (walking, cycling or using public transport) is relatively unexplored. This study explores the potential for workplaces to reduce employees' driving to work in order to inform the development of workplace interventions for promoting active travel.</p> <p>Methods</p> <p>An analysis of a cross-sectional survey was conducted using data from parents/guardians whose children participated in the Central Sydney Walk to School Program in inner-west Sydney, Australia. A total of 888 parents/guardians who were employed and worked outside home were included in this analysis. The role of the workplace in regards to active travel was assessed by asking the respondents' level of agreement to eight statements including workplace encouragement of active travel, flexible working hours, public transport availability, convenient parking, shower and change rooms for employees and whether they lived or worked in a safe place. Self-reported main mode of journey to work and demographic data were collected through a self-administrated survey. Binary logistic regression modelling was used to ascertain independent predictors of driving to work.</p> <p>Results</p> <p>Sixty nine per cent of respondents travelled to work by car, and 19% agreed with the statement, "My workplace encourages its employees to go to and from work by public transport, cycling and/or walking (active travel)." The survey respondents with a workplace encouraging active travel to work were significantly less likely to drive to work (49%) than those without this encouragement (73%) with an adjusted odds ratio (AOR) of 0.41 (95% CI 0.23-0.73, P = 0.002). Having convenient public transport close to the workplace or home was also an important factor that could discourage employees from driving to work with AOR 0.17 (95% CI 0.09-0.31, P < 0.0001) and AOR 0.50 (95% CI 0.28-0.90, P = 0.02) respectively. In contrast, convenient parking near the workplace significantly increased the likelihood of respondents driving to work (AOR 4.6, 95% CI 2.8-7.4, P < 0.0001).</p> <p>Conclusions</p> <p>There is a significant inverse association between the perception of workplace encouragement for active travel and driving to work. Increases in the number of workplaces that encourage their employees to commute to work via active travel could potentially lead to fewer employees driving to work. In order to make active travel more appealing than driving to work, workplace interventions should consider developing supportive workplace policies and environments.</p

    Can Systemic Interventions Designed to Reduce Reoffending by Youth also Reduce their Victimization?

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    Previous research indicates considerable overlap between populations of boys who are victimized and boys who victimize others. This study was concerned with whether a systems-focused treatment program designed to address individual and systemic risk factors associated with the perpetration of sexual and violent crimes might also be successful in reducing boys’ victimization by others. Boys adjudicated for sexual offences who received ‘treatment as usual’ (TAU; n = 335) were compared with similarly adjudicated boys who completed the treatment program (n = 200) on their histories of contact with police either as offenders or victims. Despite their higher rates of pre-intervention victimization, the treatment group were victimized less frequently post-intervention than the TAU group. Continued offending was the strongest predictor of victimization post-intervention. These findings suggest that offending and victimization share common risk factors that may be addressed simultaneously within offence-focused treatment

    Does the history of food energy units suggest a solution to "Calorie confusion"?

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    The Calorie (kcal) of present U.S. food labels is similar to the original French definition of 1825. The original published source (now available on the internet) defined the Calorie as the quantity of heat needed to raise the temperature of 1 kg of water from 0 to 1°C. The Calorie originated in studies concerning fuel efficiency for the steam engine and had entered dictionaries by 1840. It was the only energy unit in English dictionaries available to W.O. Atwater in 1887 for his popular articles on food and tables of food composition. Therefore, the Calorie became the preferred unit of potential energy in nutrition science and dietetics, but was displaced when the joule, g-calorie and kcal were introduced. This article will explain the context in which Nicolas Clément-Desormes defined the original Calorie and the depth of his collaboration with Sadi Carnot. It will review the history of other energy units and show how the original Calorie was usurped during the period of international standardization. As a result, no form of the Calorie is recognized as an SI unit. It is untenable to continue to use the same word for different thermal units (g-calorie and kg-calorie) and to use different words for the same unit (Calorie and kcal). The only valid use of the Calorie is in common speech and public nutrition education. To avoid ongoing confusion, scientists should complete the transition to the joule and cease using kcal in any context
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