Shocked H2 and Fe+ Dynamics in the Orion Bullets

Observations of H2 velocity profiles in the two most clearly defined Orion bullets are extremely difficult to reconcile with existing steady-state shock models. We have observed [FeII] 1.644um velocity profiles of selected bullets and H2 1-0 S(1) 2.122um velocity profiles for a series of positions along and across the corresponding bow-shaped shock fronts driven into the surrounding molecular cloud. Integrated [FeII] velocity profiles of the brightest bullets are consistent with theoretical bow shock predictions. However, observations of broad, singly-peaked H2 1-0 S(1) profiles at a range of positions within the most clearly resolved bullet wakes are not consistent with molecular shock modelling. A uniform, collisionally broadened background component which pervades the region in both tracers is inconsistent with fluorescence due to the ionizing radiation of the Trapezium stars alone.Comment: 20 pages including 18 figures, published in MNRA

USE OF ALTERNATIVE DEPRECIATION METHODS TO ESTIMATE FARM TRACTOR VALUES

Six depreciation methods were used to simulate the value of farm tractors with indexed and expected prices. Accuracy of simulated values was evaluated using paired t-tests of mean absolute percentage errors and forecast accuracy regression models. Results varied with age and use. Some depreciation methods were more accurate than others.Farm Management, Financial Economics,

Nonlinear stabilitty for steady vortex pairs

In this article, we prove nonlinear orbital stability for steadily translating vortex pairs, a family of nonlinear waves that are exact solutions of the incompressible, two-dimensional Euler equations. We use an adaptation of Kelvin's variational principle, maximizing kinetic energy penalised by a multiple of momentum among mirror-symmetric isovortical rearrangements. This formulation has the advantage that the functional to be maximized and the constraint set are both invariant under the flow of the time-dependent Euler equations, and this observation is used strongly in the analysis. Previous work on existence yields a wide class of examples to which our result applies.Comment: 25 page

Marketers’ Use Of Alternative Front-Of-Package Nutrition Symbols: An Examination Of Effects On Product Evaluations

How front-of-package (FOP) nutrition icon systems affect product evaluations for more and less healthful objective nutrition profiles is a critical question facing food marketers, consumers, and the public health community. We propose a conceptually-based hierarchical continuum to guide predictions regarding the effectiveness of several FOP systems currently used in the marketplace. In Studies 1a and 1b, we compare the effects of a broad set of FOP icons on nutrition evaluations linked to health, accuracy of evaluations, and purchase intentions for a single product. Based on these findings, Studies 2 and 3 test the effects of two conceptually-different FOP icon systems in a retail laboratory in which consumers make comparative evaluations of multiple products at the retail shelf. While there are favorable effects of each system beyond control conditions with no FOP icons, results show that icons with an evaluative component that aid consumers’ interpretations generally provide greater benefits (particularly in product comparison contexts). We offer implications for consumer packaged goods marketers, retailers, and the public policy and consumer health communities

Screening for mood disorders after stroke: a systematic review of psychometric properties and clinical utility

BackgroundRoutine mood screening is recommended after stroke. However, clinicians report difficulty selecting appropriate tools from the wide range available. We aimed to systematically review the psychometric properties and clinical utility of mood screening tools for stroke survivors.MethodElectronic databases (AMED, EMBASE, CINAHL, Medline and PsycINFO) were searched to identify studies assessing the sensitivity and specificity of mood screening tools. Tools that demonstrated at least 80% sensitivity and 60% specificity with stroke survivors with identifiable cut-off scores indicating major and/or any mood disorder in at least one study were selected and clinical utility was assessed. Those with high clinical utility (against predefined criteria) were selected for recommendation.ResultsThirty papers examining 27 screening tools were identified and 16 tools met the psychometric and clinical utility criteria: 10 were verbal self-report tools, four were observational and two incorporated visual prompts for those with communication problems. Only the Stroke Aphasic Depression Questionnaire –Hospital version (SADQ-H) met all the psychometric and utility criteria. The nine-item Patient Health Questionnaire (PHQ-9) can detect major depression and the 15-item Geriatric Depression Scale (GDS-15) can identify milder symptoms; both are feasible to use in clinical practice. The Hospital Anxiety and Depression Scale (HADS) was the only tool able to identify anxiety accurately, but clinical utility was mixed.ConclusionsValid and clinically feasible mood screening tools for stroke have been identified but methodological inconsistency prevented recommendations about the optimal cut-off scores.</jats:sec

Electrically driven magnetism on a Pd thin film

Using first-principles density functional calculations we demonstrate that ferromagnetism can be induced and modulated on an otherwise paramagnetic Pd metal thin-film surface through application of an external electric field. As free charges are either accumulated or depleted at the Pd surface to screen the applied electric field there is a corresponding change in the surface density of states. This change can be made sufficient for the Fermi-level density of states to satisfy the Stoner criterion, driving a transition locally at the surface from a paramagnetic state to an itinerant ferromagnetic state above a critical applied electric field, Ec. Furthermore, due to the second-order nature of this transition, the surface magnetization of the ferromagnetic state just above the transition exhibits a substantial dependence on electric field, as the result of an enhanced magnetoelectric susceptibility. Using a linearized Stoner model we explain the occurrence of the itinerant ferromagnetism and demonstrate that the magnetic moment on the Pd surface follows a square-root variation with electric field consistent with our first-principles calculations.Comment: 8 pages, 7 figure

The placenta: a multifaceted, transient organ.

The placenta is arguably the most important organ of the body, but paradoxically the most poorly understood. During its transient existence, it performs actions that are later taken on by diverse separate organs, including the lungs, liver, gut, kidneys and endocrine glands. Its principal function is to supply the fetus, and in particular, the fetal brain, with oxygen and nutrients. The placenta is structurally adapted to achieve this, possessing a large surface area for exchange and a thin interhaemal membrane separating the maternal and fetal circulations. In addition, it adopts other strategies that are key to facilitating transfer, including remodelling of the maternal uterine arteries that supply the placenta to ensure optimal perfusion. Furthermore, placental hormones have profound effects on maternal metabolism, initially building up her energy reserves and then releasing these to support fetal growth in later pregnancy and lactation post-natally. Bipedalism has posed unique haemodynamic challenges to the placental circulation, as pressure applied to the vena cava by the pregnant uterus may compromise venous return to the heart. These challenges, along with the immune interactions involved in maternal arterial remodelling, may explain complications of pregnancy that are almost unique to the human, including pre-eclampsia. Such complications may represent a trade-off against the provision for a large fetal brain.This is the accepted manuscript. It's currently embargoed until 19/01/2016. the final version is available from Royal Society Publishing at http://rstb.royalsocietypublishing.org/content/370/1663/2014006

Mapping warm molecular hydrogen with Spitzer's Infrared Array Camera (IRAC)

Photometric maps, obtained with Spitzer's Infrared Array Camera (IRAC), can provide a valuable probe of warm molecular hydrogen within the interstellar medium. IRAC maps of the supernova remnant IC443, extracted from the Spitzer archive, are strikingly similar to spectral line maps of the H2 pure rotational transitions that we obtained with the Infrared Spectrograph (IRS) instrument on Spitzer. IRS spectroscopy indicates that IRAC Bands 3 and 4 are indeed dominated by the H2 v=0-0 S(5) and S(7) transitions, respectively. Modeling of the H2 excitation suggests that Bands 1 and 2 are dominated by H2 v=1-0 O(5) and v=0-0 S(9). Large maps of the H2 emission in IC433, obtained with IRAC, show band ratios that are inconsistent with the presence of gas at a single temperature. The relative strengths of IRAC Bands 2, 3, and 4 are consistent with pure H2 emission from shocked material with a power-law distribution of gas temperatures. CO vibrational emissions do not contribute significantly to the observed Band 2 intensity. Assuming that the column density of H2 at temperatures T to T+dT is proportional to T raised to the power -b for temperatures up to 4000 K, we obtained a typical estimate of 4.5 for b. The power-law index, b, shows variations over the range 3 to 6 within the set of different sight-lines probed by the maps, with the majority of sight-lines showing b in the range 4 to 5. The observed power-law index is consistent with the predictions of simple models for paraboloidal bow shocks.Comment: 27 pages, including 11 figures. Accepted for publication in Ap

Master agreement task order 2 - Analyses and limited evaluations of payload and landing system structures for the survivable soft landing of instrument payloads

Computer programs for analysis and evaluation of payload and landing system structures for soft landing of instrument package

Making authentic: exploring boundary objects and bricolage in knowledge mobilisation through National Health Service-university partnerships

Background: In healthcare, bridging the research-to-practice gap is a top priority. Knowledge mobilisation scholars suggest that this gap can be closed through collaboration between knowledge users and producers. The concept of boundary objects – shared things and ideas that enable communication – has gained popularity across various collaborative work practices, but their potential within knowledge mobilisation in health care is understudied. An ongoing challenge for designers of boundary objects is how to create objects that are valued and shared both in principle and in practice. Aims and objectives: This paper reports on a study of boundary objects used during knowledge mobilisation through NHS-university partnerships called Collaborations for Leadership in Applied Health Research and Care (CLAHRCs). The distinction is investigated between boundary objects-in-theory and boundary objects-in-use, considering whether the latter possess specific characteristics which make them more effective during knowledge mobilisation. Methods: A qualitative case study of three CLAHRCs was conducted. Twenty-one people employed as ‘boundary spanners’ were interviewed to explore whether boundary objects played a role in knowledge mobilisation. Findings: The most effective boundary objects-in-use were co-produced through a process of bricolage. These possessed high levels of meaningfulness and resonance, and reconciled multiple user perspectives. Together these properties contributed to the overall authenticity of boundary objects-in-use. Discussion and conclusion: This paper helps to explain why designated boundary objects frequently fail in practice, and why there is a need to focus on understanding boundary objects based on symbolic, rather than structural, dimensions