8,373 research outputs found

    The Impact of Strategic Trajectory Optimization on Illusory Target Biases During Goal-Directed Aiming

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    During rapid aiming, movements are planned and executed to avoid worst-case outcomes that require time and energy to correct. As such, downward movements initially undershoot the target to avoid corrections against gravity. Illusory target context can also impact aiming bias. Here, the authors sought to determine how strategic biases mediate illusory biases. Participants aimed to MĂŒller-Lyer figures in different directions (forward, backward, up, down). Downward biases emerged late in the movement and illusory biases emerged from peak velocity. The illusory effects were greater for downward movements at terminal endpoint. These results indicate that strategic biases interact with the limb-target control processes associated with illusory biases. Thus, multiple control processes during rapid aiming may combine and later affect endpoint accuracy (D. Elliott et al., 2010)

    Supporting early family life: the importance of public health programmes

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    Globally, women are generally offered maternity-specific care during their pregnancy through obstetricians, gynaecologists, nurses and/or midwives. While this care extends into the postpartum period, guidelines currently do not recommend visits to the mother beyond 6 weeks (World Health Organisation, 2014). However, in the Fair Society, Healthy Lives report, it is emphasised that the two first years of life represent a critical time point in which the obstacles to healthy brain development can lead to long-term disadvantages, and that interventions are required to prevent the emergence of health inequalities and to improve children’s life-chances (Marmot et al, 2010). In attempts to prevent ill health in infants, a number of countries provide services that traverse both the antenatal period and the early years of life. Examples of such services include the Healthy Child Programme in the UK, the Maternal and Child Health Service in Australia, and the Comprehensive Child Development Service in Hong Kong. While these services differ, they are structurally similar in that they provide a universal preventative service with a programme of care that encompasses screening, immunisation, health and development reviews, supplemented by advice around health, wellbeing and parenting. In accordance with the principle of ‘proportionate universalism’, the scale and intensity of intervention is proportionate to the level of disadvantage to ensure more vulnerable families receive increased care and that safeguarding takes place for children at increased risk (Marmot et al, 2010)

    The Multiple Process Model of Goal-Directed Reaching Revisited

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    Recently our group forwarded a model of speed-accuracy relations in goal-directed reaching. A fundamental feature of our multiple process model was the distinction between two types of online regulation: impulse control and limb-target control. Impulse control begins during the initial stages of the movement trajectory and involves a comparison of actual limb velocity and direction to an internal representation of expectations about the limb trajectory. Limb-target control involves discrete error-reduction based on the relative positions of the limb and the target late in the movement. Our model also considers the role of eye movements, practice, energy optimization and strategic behavior in limb control. Here, we review recent work conducted to test specific aspects of our model. As well, we consider research not fully incorporated into our earlier contribution. We conclude that a slightly modified and expanded version of our model, that includes crosstalk between the two forms of online regulation, does an excellent job of explaining speed, accuracy, and energy optimization in goal-directed reaching

    The Lippmann–Schwinger Formula and One Dimensional Models with Dirac Delta Interactions

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    We show how a proper use of the Lippmann–Schwinger equation simplifies the calculations to obtain scattering states for one dimensional systems perturbed by N Dirac delta equations. Here, we consider two situations. In the former, attractive Dirac deltas perturbed the free one dimensional Schrödinger Hamiltonian. We obtain explicit expressions for scattering and Gamow states. For completeness, we show that the method to obtain bound states use comparable formulas, although not based on the Lippmann–Schwinger equation. Then, the attractive N deltas perturbed the one dimensional Salpeter equation. We also obtain explicit expressions for the scattering wave functions. Here, we need regularisation techniques that we implement via heat kernel regularisation

    Facility-based stillbirth review processes used in different countries across the world: a systematic review

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    Background: Facility-based stillbirth review provides opportunities to estimate incidence, evaluate causes and risk factors for stillbirths, and identify any issues related to the quality of pregnancy and childbirth care which require improvement. Our aim was to systematically review all types and methods of facility-based stillbirth review processes used in different countries across the world, to examine how stillbirth reviews in facility settings are being conducted worldwide and to identify the outcomes of implementing the reviews. Moreover, to identify facilitators and barriers influencing the implementation of the identified facility-based stillbirth reviews processes by conducting subgroup analyses. Methods: A systematic review of published literature was conducted by searching MEDLINE (OvidSP) [1946-present], EMBASE (OvidSP) [1974-present], WHO Global Index Medicus (globalindexmedicus.net), Global Health (OvidSP) [1973–2022 Week 8] and CINAHL (EBSCOHost) [1982-present] from their inception until 11 January, 2023. For unpublished or grey literature, the WHO databases, Google Scholar and ProQuest Dissertations & Theses Global were searched, as well as hand searching the reference lists of included studies. MESH terms encompassing “∗Clinical Audit”, “∗Perinatal Mortality”, “Pregnancy Complications”, and “Stillbirth” were used with Boolean operators. Studies that used a facility-based review process or any approach to evaluate care prior to stillbirth, and explained the methods used were included. Reviews and editorials were excluded. Three authors (YYB, UGA, and DBT) independently screened and extracted data, and assessed the risk of bias using an adapted JBI's Checklist for Case Series. A logic model was used to inform the narrative synthesis. The review protocol was registered with PROSPERO, CRD42022304239. Findings: A total of 68 studies from 17 high-income (HICs) and 22 low-and-middle-income countries (LMICs) met the inclusion criteria from a total of 7258 identified records. These were stillbirth reviews conducted at different levels: district, state, national, and international. Three types were identified: audit, review, and confidential enquiry, but not all desired components were included in most processes, which led to a mismatch between the description of the type and the actual method used. Routine data from hospital records was the most common data source for identifying stillbirths, and case assessment was based on stillbirth definition in 48 out of 68 studies. Hospital notes were the most common source of information about care received and causes/risk factors for stillbirth. Short-term and medium-term outcomes were reported in 14 studies, but impact of the review process on reducing stillbirth, which is more difficult to establish, was not reported in any study. Facilitators and barriers in implementing a successful stillbirth review process identified from 14 studies focused on three main themes: resources, expertise, and commitment. Interpretation: This systematic review's findings identified that there is a need for clear guidelines on how to measure the impact of implementation of changes based on outputs of stillbirth reviews and methods to enable effective dissemination of learning points in the future and promoting them through training platforms. In addition, there is a need to develop and adopt a universal definition of stillbirth to facilitate meaningful comparison of stillbirth rates between regions. The key limitation of this review is that while using a logic model for narrative synthesis was deemed most appropriate for this study, sequence of implementing a stillbirth review in the real world is not linear, and assumptions are often not met. Therefore, the logic model proposed in this study should be interpreted with flexibility when designing a stillbirth review process. The generated learnings from the stillbirth review processes inform the action plans and allow facilities to consider where the changes should happen to improve the quality of care in the facilities, enabling positive short-term and medium-term outcomes. Funding: Kellogg College, University of Oxford, Clarendon Fund, University of Oxford, Nuffield Department of Population Health, University of Oxford and Medical Research Council (MRC)

    Seasonal and interannual variability in wind field and commercial catch rates of austroglossus pectoralis (soleidae)

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    The impact of deviations in the direction and strength of the wind field on the spatial, seasonal and interannual variability in catch rates of Agulhas sole Austroglossus pectoralis was investigated. Temporal variabilityin the wind cycle on the Agulhas Bank during the period 1981–1996 was deduced mainly from trends in the pressure gradient, measured from south of Cape Agulhas (35°S) to the region of westwind drift (40°S).Because interannual deviations in the catch rates differed between seasons, catch rates were assessed by season. Coastal catch rates of Agulhas sole between Cape Agulhas and Cape Infanta were high in autumn and winter, when offshore north-westerly winds prevailed, and low in spring and late summer, when onshore south-easterly winds dominated. There was often a secondary peak in catch rates in November–December,coincident with a midsummer change in the pressure gradient. Between the period 1982 and 1996, catch rates in autumn and early winter (April–July) were highest during years when the winter north-westerly winds were strongest (r2 = 0.62, p < 0.01). Catch rates usually peaked in May–June. This pattern changed in some years, depending on the timing and rate of change to winter wind conditions. Seasonal and interannual fluctuations in catch rate are associated with deviations in the wind field, but the  mechanism whereby this  effect is mediated remains unknown

    Automatic estimation of harmonic tension by distributed representation of chords

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    The buildup and release of a sense of tension is one of the most essential aspects of the process of listening to music. A veridical computational model of perceived musical tension would be an important ingredient for many music informatics applications. The present paper presents a new approach to modelling harmonic tension based on a distributed representation of chords. The starting hypothesis is that harmonic tension as perceived by human listeners is related, among other things, to the expectedness of harmonic units (chords) in their local harmonic context. We train a word2vec-type neural network to learn a vector space that captures contextual similarity and expectedness, and define a quantitative measure of harmonic tension on top of this. To assess the veridicality of the model, we compare its outputs on a number of well-defined chord classes and cadential contexts to results from pertinent empirical studies in music psychology. Statistical analysis shows that the model's predictions conform very well with empirical evidence obtained from human listeners.Comment: 12 pages, 4 figures. To appear in Proceedings of the 13th International Symposium on Computer Music Multidisciplinary Research (CMMR), Porto, Portuga

    Microbial catabolic activities are naturally selected by metabolic energy harvest rate

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    The fundamental trade-off between yield and rate of energy harvest per unit of substrate has been largely discussed as a main characteristic for microbial established cooperation or competition. In this study, this point is addressed by developing a generalized model that simulates competition between existing and not experimentally reported microbial catabolic activities defined only based on well-known biochemical pathways. No specific microbial physiological adaptations are considered, growth yield is calculated coupled to catabolism energetics and a common maximum biomass-specific catabolism rate (expressed as electron transfer rate) is assumed for all microbial groups. Under this approach, successful microbial metabolisms are predicted in line with experimental observations under the hypothesis of maximum energy harvest rate. Two microbial ecosystems, typically found in wastewater treatment plants, are simulated, namely: (i) the anaerobic fermentation of glucose and (ii) the oxidation and reduction of nitrogen under aerobic autotrophic (nitrification) and anoxic heterotrophic and autotrophic (denitrification) conditions. The experimentally observed cross feeding in glucose fermentation, through multiple intermediate fermentation pathways, towards ultimately methane and carbon dioxide is predicted. Analogously, two-stage nitrification (by ammonium and nitrite oxidizers) is predicted as prevailing over nitrification in one stage. Conversely, denitrification is predicted in one stage (by denitrifiers) as well as anammox (anaerobic ammonium oxidation). The model results suggest that these observations are a direct consequence of the different energy yields per electron transferred at the different steps of the pathways. Overall, our results theoretically support the hypothesis that successful microbial catabolic activities are selected by an overall maximum energy harvest rate
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