1,251 research outputs found

    Virtual patients design and its effect on clinical reasoning and student experience : a protocol for a randomised factorial multi-centre study

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    Background Virtual Patients (VPs) are web-based representations of realistic clinical cases. They are proposed as being an optimal method for teaching clinical reasoning skills. International standards exist which define precisely what constitutes a VP. There are multiple design possibilities for VPs, however there is little formal evidence to support individual design features. The purpose of this trial is to explore the effect of two different potentially important design features on clinical reasoning skills and the student experience. These are the branching case pathways (present or absent) and structured clinical reasoning feedback (present or absent). Methods/Design This is a multi-centre randomised 2x2 factorial design study evaluating two independent variables of VP design, branching (present or absent), and structured clinical reasoning feedback (present or absent).The study will be carried out in medical student volunteers in one year group from three university medical schools in the United Kingdom, Warwick, Keele and Birmingham. There are four core musculoskeletal topics. Each case can be designed in four different ways, equating to 16 VPs required for the research. Students will be randomised to four groups, completing the four VP topics in the same order, but with each group exposed to a different VP design sequentially. All students will be exposed to the four designs. Primary outcomes are performance for each case design in a standardized fifteen item clinical reasoning assessment, integrated into each VP, which is identical for each topic. Additionally a 15-item self-reported evaluation is completed for each VP, based on a widely used EViP tool. Student patterns of use of the VPs will be recorded. In one centre, formative clinical and examination performance will be recorded, along with a self reported pre and post-intervention reasoning score, the DTI. Our power calculations indicate a sample size of 112 is required for both primary outcomes

    Aspectos genéticos em estrabismo

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    Purpose: To evaluate the genetic aspects of strabismus. Methods: Ophthalmic and orthoptic evaluations were performed prospectively on 110 strabismic probands and 478 relatives. We used 3 different criteria in the diagnosis of strabismus: primary diagnosis (dx1) defined as any manifest horizontal or vertical deviation, a secondary diagnosis (dx2) including esophoria (>7 prism diopters) or exophoria (>9 prism diopters), and a tertiary diagnosis (dx3) including abnormal fusional amplitudes, accommodative convergence/accommodation (AC/A) ratio, and/or stereopsis; monofixation syndrome; 4 prism diopters base out; and/or abnormal Maddox test responses. Analyses were carried out within mating types. Results: Hypotheses of autosomal dominant or recessive inheritance with no sporadics were rejected. Based on the dx1, 25% of the families had more than one individual affected and there was vertical transmission in 13%; adding dx2 there were 36% of the families with more than one affected and 21% had vertical transmission; and adding dx3, there were 73% with more than one affected and 51% with vertical transmission. Conclusions: There is evidence for a pattern consistent with an autosomal dominant form of strabismus in most families.Objetivo: Avaliar aspectos genéticos em estrabismo. Métodos: Foram realizados exames oftalmológicos e ortópticos prospectivamente em 110 propósitos estrábicos e 478 familiares. Foram usados 3 diferentes critérios no diagnóstico de estrabismo: diagnóstico primário (dx1) foi definido como qualquer desvio horizontal ou vertical manifesto, diagnóstico secundário (dx2) incluiu esoforias (> 7 dioptrias prismáticas) ou exoforia (< 9 dioptrias prismáticas) e diagnóstico terciário (dx3), que incluiu amplitudes de fusão anormal, relação convergência acomodativa/acomodação (CA/A) elevada, estereopsia anormal, síndrome de monofixação, e teste das 4 dioptrias prismáticas e teste de Maddox anormais. A análise dos resultados foi por meio da avaliação dos pedigrees segundo o tipo de união. Resultados: As hipóteses de herança autossômicas dominantes ou recessivas sem casos esporádicos foram rejeitadas. Baseado no dx1, 25% das famílias tiveram mais de um indivíduo afetado e houve transmissão vertical em 13%; adicionando o dx2, foi encontrado que 36% das famílias tinham mais de um membro afetado e houve transmissão vertical em 21%; e adicionando dx3, 73% das famílias tinham mais de um membro afetado e houve transmissão vertical em 51% delas. Conclusão: Existem evidências que apontam para um padrão compatível com herança autossômica dominante na maioria das famílias.Federal University of São Paulo Department of OphthalmologyUCLA Jules Stein Eye Institute Department of OphthalmologyUniversity of Colorado The Children's Hospital Rocky Mountain Lions Eye InstituteUNIFESP, Department of OphthalmologySciEL

    The relationship between web enjoyment and student perceptions and learning using a web-based tutorial

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    Web enjoyment has been regarded as a component of system experience. However, there has been little targeted research considering the role of web enjoyment alone in student learning using web-based systems. To address this gap, this study aims to examine the influence of web enjoyment on learning performance and perceptions by controlling system experience as a variable in the study. 74 students participated in the study, using a web-based tutorial covering subject matter in the area of 'Computation and algorithms'. Their learning performance was assessed with a pre-test and a post-test and their learning perceptions were evaluated with a questionnaire. The results indicated that there are positive relationships between the levels of web enjoyment and perceived usefulness and non-linear navigation for users with similar, significant levels of system experience. The implications of these findings in relation to web-based learning are explored and ways in which the needs of students who report different levels of web enjoyment might be met are discussed

    Lime stabilisation for earthworks: a UK perspective

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    Lime stabilisation is a versatile technique applied during earthworks operations. Modern soil recycling units are much more efficient at pulverising fill material and intermixing the added binder/water than machinery available 20 years ago. While supplier innovation adds flexibility to the site working method, specifications have not been sufficiently updated to permit optimal application. This review paper details the physico-chemical changes instigated through the lime-clay soil reaction, updating previous reviews. It aims to assist scientific debate, current practitioners and future specification changes. For example, the application of the minimum 24 h mellowing periods (mandatory to UK specifications) with high reactivity, quicklime powders is concluded to cause increased air voids in the compacted fill. Increased air voids are associated with reduced long-term strength and potential volume change from water ingress, which is of particular concern for sulfate swelling. Shorter mellowing periods and/or use of hydrated lime may lesson this issue; however, a 'one size fits all' approach is discouraged in preference to site-specific methodologies refined to suit the fill material and project requirements. The discussion also summarises working methods which may lower the risk of sulfate swell and defines areas requiring further practical research

    Roy-Steiner equations for pion-nucleon scattering

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    Starting from hyperbolic dispersion relations, we derive a closed system of Roy-Steiner equations for pion-nucleon scattering that respects analyticity, unitarity, and crossing symmetry. We work out analytically all kernel functions and unitarity relations required for the lowest partial waves. In order to suppress the dependence on the high-energy regime we also consider once- and twice-subtracted versions of the equations, where we identify the subtraction constants with subthreshold parameters. Assuming Mandelstam analyticity we determine the maximal range of validity of these equations. As a first step towards the solution of the full system we cast the equations for the ππNˉN\pi\pi\to\bar NN partial waves into the form of a Muskhelishvili-Omn\`es problem with finite matching point, which we solve numerically in the single-channel approximation. We investigate in detail the role of individual contributions to our solutions and discuss some consequences for the spectral functions of the nucleon electromagnetic form factors.Comment: 106 pages, 18 figures; version published in JHE

    Dynamical chiral symmetry breaking by a magnetic field and multi-quark interactions

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    Catalysis of dynamical symmetry breaking by a constant magnetic field in (3+1) dimensions is considered. We use the three flavour Nambu -- Jona-Lasinio type model with 't Hooft and eight-quark interaction terms. It is shown that the multi-quark interactions introduce new additional features to this phenomenon: (a) the local minimum of the effective potential catalyzed by the constant magnetic field is smoothed out with increasing strength of the field at the characteristic scale H~10^{19} G, (b) the multi-quark forces generate independently another local minimum associated with a larger dynamical fermion mass. This state may exist even for multi-quark interactions with a subcritical set of couplings, and is globally stable with respect to a further increase of the magnetic field.Comment: 6 pages, 3 figures, added discussion and references, version to appear in Phys.Lett.

    Ovine pedomics : the first study of the ovine foot 16S rRNA-based microbiome

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    We report the first study of the bacterial microbiome of ovine interdigital skin based on 16S rRNA by pyrosequencing and conventional cloning with Sanger-sequencing. Three flocks were selected, one a flock with no signs of footrot or interdigital dermatitis, a second flock with interdigital dermatitis alone and a third flock with both interdigital dermatitis and footrot. The sheep were classified as having either healthy interdigital skin (H), interdigital dermatitis (ID) or virulent footrot (VFR). The ovine interdigital skin bacterial community varied significantly by flock and clinical condition. The diversity and richness of operational taxonomic units was greater in tissue from sheep with ID than H or VFR affected sheep. Actinobacteria, Bacteriodetes, Firmicutes and Proteobacteria were the most abundant phyla comprising 25 genera. Peptostreptococcus, Corynebacterium and Staphylococcus were associated with H, ID and VFR respectively. Sequences of Dichelobacter nodosus, the causal agent of ovine footrot, were not amplified due to mismatches in the 16S rRNA universal forward primer (27F). A specific real time PCR assay was used to demonstrate the presence of D. nodosus which was detected in all samples including the flock with no signs of ID or VFR. Sheep with ID had significantly higher numbers of D. nodosus (104-109 cells/g tissue) than those with H or VFR feet

    Postcopulatory sexual selection

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    The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to generate a startling diversity of morphological, behavioural and physiological adaptations. We identify three main issues that should be resolved to advance our understanding of postcopulatory sexual selection. We need to determine the genetic basis of different male fertility traits and female traits that mediate sperm selection; identify the genes or genomic regions that control these traits; and establish the coevolutionary trajectory of sexes

    Disposition of Federally Owned Surpluses

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    PDZ domains are scaffolding modules in protein-protein interactions that mediate numerous physiological functions by interacting canonically with the C-terminus or non-canonically with an internal motif of protein ligands. A conserved carboxylate-binding site in the PDZ domain facilitates binding via backbone hydrogen bonds; however, little is known about the role of these hydrogen bonds due to experimental challenges with backbone mutations. Here we address this interaction by generating semisynthetic PDZ domains containing backbone amide-to-ester mutations and evaluating the importance of individual hydrogen bonds for ligand binding. We observe substantial and differential effects upon amide-to-ester mutation in PDZ2 of postsynaptic density protein 95 and other PDZ domains, suggesting that hydrogen bonding at the carboxylate-binding site contributes to both affinity and selectivity. In particular, the hydrogen-bonding pattern is surprisingly different between the non-canonical and canonical interaction. Our data provide a detailed understanding of the role of hydrogen bonds in protein-protein interactions

    Using stated preference methods to assess environmental impacts of forest biomass power plants in Portugal

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    As a renewable energy source, the use of forest biomass for electricity generation is advantageous in comparison with fossil fuels, however the activity of forest biomass power plants causes adverse impacts, affecting particularly neighbouring communities. The main objective of this study is to estimate the effects of the activity of forest biomass power plants on the welfare of two groups of stakeholders, namely local residents and the general population and we apply two stated preference methods: contingent valuation and discrete choice experiments, respectively. The former method was applied to estimate the minimum compensation residents of neighbouring communities of two forest biomass power plants in Portugal would be willing to accept. The latter method was applied among the general population to estimate their willingness to pay to avoid specific environmental impacts. The results show that the presence of the selected facilities affects individuals’ well-being. On the other hand, in the discrete choice experiments conducted among the general population all impacts considered were significant determinants of respondents’ welfare levels. The results of this study stress the importance of performing an equity analysis of the welfare effects on different groups of stakeholders from the installation of forest biomass power plants, as their effects on welfare are location and impact specific. Policy makers should take into account the views of all stakeholders either directly or indirectly involved when deciding crucial issues regarding the sitting of new forest biomass power plants, in order to achieve an efficient and equitable outcome
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