836 research outputs found

    The Northern Bob-White\u27s winter territory

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    This bulletin attempts to bring up to date our knowledge o[ individual covey ranges or wintering territories of the bobwhite quail [Colinus virginianus virginianus (Linn.)] (Fig. 1.) It is based upon all of the pertinent and reliable data upon the subject at hand, of whatever origin and whatever degree of previous publication. Pertinence and reliability constitute the sole criteria by which we have attempted to judge the eligibility of data used, whether the data support our principal conclusions or not

    The great horned owl and its prey in north-central United States

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    Along with other predatory species, the great horned owl has been studied in north-central United States, particularly in Iowa and southern Wisconsin localities in which ecological research upon certain prey types has been carried on contemporaneously. After investigation by field and laboratory methods involving experimentation with captive horned owls and observation in nature, it became obvious that the mass data on feeding trends required by the program could be best obtained through pellet studies supplemented by whatever additional techniques would yield information. The horned owl food habits data upon which this bulletin is partly based were gathered largely between 1930 and 1935 and were the product of experience with 84 horned owl nests, examination of 4,815 pellets and 23 food-containing stomachs and records of direct predation. The prey types studied were chiefly upland game birds, waterfowl and fur-bearers, though many other forms were observed incidentally. The general procedure was to continue, so far as feasible, work on predation and population year after year on specific areas and to correlate the data from both; in this way, not only have some of the reasons for pronounced changes in food habits of predators become evident, but a superior background for evaluating effects of predation upon population levels of prey species has also resulted

    Analysing The Role of Virtualisation and Visualisation on Interdisciplinary Knowledge Exchange in Stem Cell Research Processes

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    Interdisciplinary work is an increasingly frequent and important aspect of scientific research. However, successful knowledge exchange and collaboration between experts is itself a challenging activity with both technical and social components that require consideration. Here, this article analyses the cultural factors involved in interdisciplinary research, specifically in the context of a software programme designed to improve knowledge exchange. The authors undertook an ethnographic study to understand the impact of virtualisation and visualisation on an interdisciplinary research team, working together to develop novel imaging technologies for investigating stem cells. In this discovery-research environment the challenge was to determine the socio-technical effect of an in-house software tool called ProtocolNavigator, which provided a virtual laboratory environment for the team to simulate and map their ‘real-life laboratory’ activities. This display, together with activity icons and a timeline, could be visually analysed and transferred between multiinstitutional researchers in a non-narrative approach. The aim of the work reported here is to provide the first detailed analysis of how software of this type is used in practice, and to analyse this through a robust social science-based perspective. Subsequently this study examines the effectiveness of this virtual laboratory environment on enhancing communication and understanding using a theoretical framework drawing upon three insights from the Sociology of Expertise and Experience: (i) interactional and contributory expertise, (ii) knowledge exchange and interpretative flexibility, and (iii) trading zones. The framework was extended by introducing the notion of material, concept and practice trade at these trading zones with a demonstration of how interactive visualisation of interconnected trading routes can empower interdisciplinary work. The addition of Foucault’s classic account of power found evidence of a panoptical effect due to the augmented visibility of each other’s work. In summary, the article offers a theoretical framework together with novel analysis to determine the influence of introducing tools and approaches designed to enhance interdisciplinary working—particularly in the context of knowledge sharing and trust

    Animations to communicate public health prevention messages: a realist review protocol

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    \ua9 Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. INTRODUCTION: With digital and social media advances, animated health communications (health animations) are highly prevalent globally, yet the evidence base underpinning them remains unclear and limited. While individual studies have attempted to explore the effectiveness, acceptability and usability of specific features of health animations, there is substantial heterogeneity in study design, comparators and the animation design and content. Consequently, there is a need to synthesise evidence of health animations using an approach that recognises this contextual complexity, which may affect their impact. METHODS AND ANALYSIS: This project aims to understand why, how, for whom, to what extent and in which contexts health animations are expected to promote preventive health behaviours. We will conduct a realist review following Pawson\u27s five iterative stages to (1) define the review scope and locate existing theories; (2) search for evidence; (3) select and appraise evidence; (4) extract data and (5) synthesise data and refine theory. Engagement with stakeholders involved in developing, testing, implementing or commissioning health communications, including animations, will allow the initial programme theory to be tested and refined. The findings will be reported in accordance with Realist and Meta-narrative Evidence Syntheses: Evolving Standards. ETHICS AND DISSEMINATION: Ethical approval for the public stakeholder work was provided by the Northumbria University Research Ethics Committee. We will disseminate the findings widely through outputs tailored to target specific professional, public and patient audiences. Dissemination will occur through stakeholder engagement as part of the research, a peer-reviewed publication and conference presentations. PROSPERO REGISTRATION NUMBER: CRD42023447127

    Calculation of surface tension via area sampling

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    We examine the performance of several molecular simulation techniques aimed at evaluation of the surface tension through its thermodynamic definition. For all methods explored, the surface tension is calculated by approximating the change in Helmholtz free energy associated with a change in interfacial area through simulation of a liquid slab at constant particle number, volume, and temperature. The methods explored fall within three general classes: free-energy perturbation, the Bennett acceptance-ratio scheme, and the expanded ensemble technique. Calculations are performed for both the truncated Lennard-Jones and square-well fluids at select temperatures spaced along their respective liquid-vapor saturation lines. Overall, we find that Bennett and expanded ensemble approaches provide the best combination of accuracy and precision. All of the methods, when applied using sufficiently small area perturbation, generate equivalent results for the Lennard-Jones fluid. However, single-stage free-energy-perturbation methods and the closely related test-area technique recently introduced by Gloor et al. [J. Chem. Phys. 123, 134703 (2005)], generate surface tension values for the square-well fluid that are not consistent with those obtained from the more robust expanded ensemble and Bennett approaches, regardless of the size of the area perturbation. Single-stage perturbation methods fail also for the Lennard-Jones system when applied using large area perturbations. Here an analysis of phase-space overlap produces a quantitative explanation of the observed inaccuracy, and shows that the satisfactory results obtained in these cases from the test-area method arise from a cancellation of errors that cannot be expected in general.Comment: 28 pages, 7 figures, to appear in J. Chem. Phys. (07 Nov 2007 issue

    Accurate simulation estimates of phase behaviour in ternary mixtures with prescribed composition

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    This paper describes an isobaric semi-grand canonical ensemble Monte Carlo scheme for the accurate study of phase behaviour in ternary fluid mixtures under the experimentally relevant conditions of prescribed pressure, temperature and overall composition. It is shown how to tune the relative chemical potentials of the individual components to target some requisite overall composition and how, in regions of phase coexistence, to extract accurate estimates for the compositions and phase fractions of individual coexisting phases. The method is illustrated by tracking a path through the composition space of a model ternary Lennard-Jones mixture.Comment: 6 pages, 3 figure

    Ultrasensitivity of the Bacillus subtilis sporulation decision

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    Starving Bacillus subtilis cells execute a gene expression program resulting in the formation of stress-resistant spores. Sporulation master regulator, Spo0A, is activated by a phosphorelay and controls the expression of a multitude of genes, including the forespore- specific sigma factor σF and the mother cell-specific sigma factor σE. Identification of the system-level mechanism of the sporulation decision is hindered by a lack of direct control over Spo0A activity. This limitation can be overcome by using a synthetic system in which Spo0A activation is controlled by inducing expression of phosphorelay kinase KinA. This induction results in a switch-like increase in the number of sporulating cells at a threshold of KinA. Using a combination of mathematical modeling and single-cell microscopy, we investigate the origin and physiological significance of this ultrasensitive threshold. The results indicate that the phosphorelay is unable to achieve a sufficiently fast and ultrasensitive response via its positive feedback architecture, suggesting that the sporulation decision is made downstream. In contrast, activation of σF in the forespore and of σE in the mother cell compartments occurs via a cascade of coherent feed-forward loops, and thereby can produce fast and ultrasensitive responses as a result of KinA induction. Unlike σF activation, σE activation in the mother cell compartment only occurs above the KinA threshold, resulting in completion of sporulation. Thus, ultrasensitive σE activation explains the KinA threshold for sporulation induction. We therefore infer that under uncertain conditions, cells initiate sporulation but postpone making the sporulation decision to average stochastic fluctuations and to achieve a robust population response
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