2,995 research outputs found

    A physical model describing the interaction of nuclear transport receptors with FG nucleoporin domain assemblies

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    The permeability barrier of nuclear pore complexes (NPCs) controls bulk nucleocytoplasmic exchange. It consists of nucleoporin domains rich in phenylalanine-glycine motifs (FG domains). As a bottom-up nanoscale model for the permeability barrier, we have used planar films produced with three different end-grafted FG domains, and quantitatively analyzed the binding of two different nuclear transport receptors (NTRs), NTF2 and Importin b, together with the concomitant film thickness changes. NTR binding caused only moderate changes in film thickness; the binding isotherms showed negative cooperativity and could all be mapped onto a single master curve. This universal NTR binding behavior –a key element for the transport selectivity of the NPC –was quantitatively reproduced by a physical model that treats FG domains as regular, flexible polymers, and NTRs as spherical colloids with a homogeneous surface, ignoring the detailed arrangement of interaction sites along FG domains and on the NTR surface

    Development and initial psychometric properties of the Warwick–Edinburgh Mental Wellbeing Scale-Intellectual Disability version

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    Background: The Warwick–Edinburgh Mental Wellbeing Scale (WEMWBS; Tennant et al., 2007) is yet to be validated in the intellectual disability (ID) population. The aim of this study was to report the development process and assess the psychometric properties of a newly adapted version of the WEMWBS and the Short WEMWBS for individuals with mild to moderate IDs (WEMWBS-ID/SWEMWBS-ID). / Method: The WEMWBS item wordings and response options were revised by clinicians and researchers expert in the field of ID, and a visual aid was added to the scale. The adapted version was reviewed by 10 individuals with IDs. The measure was administered by researchers online using screenshare, to individuals aged 16+ years with mild to moderate IDs. Data from three UK samples were collated to evaluate the WEMWBS-ID (n = 96). A subsample (n = 22) completed the measure again 1 to 2 weeks later to assess test–retest reliability, and 95 participants additionally completed an adapted version of the adapted Rosenberg Self-Esteem Scale to examine convergent validity. Additional data from a Canadian sample (n = 27) were used to evaluate the SWEMWBS-ID (n = 123). / Results: The WEMWBS-ID demonstrated good internal consistency (ω = 0.77–0.87), excellent test–retest reliability [intraclass correlation coefficient (ICC) =.88] and good convergent validity with the self-esteem scale (r =.48–.60) across samples. A confirmatory factor analysis for a single factor model demonstrated an adequate fit. The SWEMWBS-ID showed poor to good internal consistency (ω = 0.36–0.74), moderate test–retest reliability (ICC =.67) and good convergent validity (r =.48–.60) across samples, and a confirmatory factor analysis indicated good model fit for a single factor structure. / Conclusions: The WEMWBS-ID and short version demonstrated promising psychometric properties, when administered virtually by a researcher. Further exploration of the scales with larger, representative samples is warranted

    A comparison of course-related stressors in undergraduate problem-based learning (PBL) versus non-PBL medical programmes

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    Background: Medical students report high levels of stress related to their medical training as well as to other personal and financial factors. The aim of this study is to investigate whether there are differences in course-related stressors reported by medical students on undergraduate problem-based learning (PBL) and non-PBL programmes in the UK. Method: A cross-sectional study of second-year medical students in two UK medical schools (one PBL and one non-PBL programme) was conducted. A 16-question self-report questionnaire, derived from the Perceived Medical Student Stress Scale and the Higher Education Stress Inventory, was used to measure course-related stressors. Following univariate analysis of each stressor between groups, multivariate logistic regression was used to determine which stressors were the best predictors of each course type, while controlling for socio-demographic differences between the groups. Results: A total of 280 students responded. Compared to the non-PBL students (N = 197), the PBL students (N = 83) were significantly more likely to agree that: they did not know what the faculty expected of them (Odds Ratio (OR) = 0.38, p = 0.03); there were too many small group sessions facilitated only by students resulting in an unclear curriculum (OR = 0.04, p < 0.0001); and that there was a lack of opportunity to explore academic subjects of interest (OR = 0.40, p = 0.02). They were significantly more likely to disagree that: there was a lack of encouragement from teachers (OR = 3.11, p = 0.02); and that the medical course fostered a sense of anonymity and feelings of isolation amongst students (OR = 3.42, p = 0.008). Conclusion: There are significant differences in the perceived course-related stressors affecting medical students on PBL and non-PBL programmes. Course designers and student support services should therefore tailor their work to minimise, or help students cope with, the specific stressors on each course type to ensure optimum learning and wellbeing among our future doctors

    Internal construct validity of the Warwick-Edinburgh Mental Well-being Scale (WEMWBS): a Rasch analysis using data from the Scottish Health Education Population Survey

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    Background: The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) was developed to meet demand for instruments to measure mental well-being. It comprises 14 positively phrased Likert-style items and fulfils classic criteria for scale development. We report here the internal construct validity of WEMWBS from the perspective of the Rasch measurement model. Methods: The model was applied to data collected from 779 respondents in Wave 12 (Autumn 2006) of the Scottish Health Education Population Survey. Respondents were aged 16–74 (average 41.9) yrs. Results: Initial fit to model expectations was poor. The items 'I've been feeling good about myself', 'I've been interested in new things' and 'I've been feeling cheerful' all showed significant misfit to model expectations, and were deleted. This led to a marginal improvement in fit to the model. After further analysis, more items were deleted and a strict unidimensional seven item scale (the Short Warwick Edinburgh Mental Well-Being Scale (SWEMWBS)) was resolved. Many items deleted because of misfit with model expectations showed considerable bias for gender. Two retained items also demonstrated bias for gender but, at the scale level, cancelled out. One further retained item 'I've been feeling optimistic about the future' showed bias for age. The correlation between the 14 item and 7 item versions was 0.954. Given fit to the Rasch model, and strict unidimensionality, SWEMWBS provides an interval scale estimate of mental well-being. Conclusion: A short 7 item version of WEMWBS was found to satisfy the strict unidimensionality expectations of the Rasch model, and be largely free of bias. This scale, SWEMWBS, provides a raw score-interval scale transformation for use in parametric procedures. In terms of face validity, SWEMWBS presents a more restricted view of mental well-being than the 14 item WEMWBS, with most items representing aspects of psychological and eudemonic well-being, and few covering hedonic well-being or affect. However, robust measurement properties combined with brevity make SWEMWBS preferable to WEMWBS at present for monitoring mental well-being in populations. Where face validity is an issue there remain arguments for continuing to collect data on the full 14 item WEMWBS

    Substance abuse and intimate partner violence: treatment considerations

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    Given the increased use of marital- and family-based treatments as part of treatment for alcoholism and other drug disorders, providers are increasingly faced with the challenge of addressing intimate partner violence among their patients and their intimate partners. Yet, effective options for clinicians who confront this issue are extremely limited. While the typical response of providers is to refer these cases to some form of batterers' treatment, three fundamental concerns make this strategy problematic: (1) most of the agencies that provide batterers' treatment only accept individuals who are legally mandated to complete their programs; (2) among programs that do accept nonmandated patients, most substance-abusing patients do not accept such referrals or drop out early in the treatment process; and (3) available evidence suggests these programs may not be effective in reducing intimate partner violence. Given these very significant concerns with the current referral approach, coupled with the high incidence of IPV among individuals entering substance abuse treatment, providers need to develop strategies for addressing IPV that can be incorporated and integrated into their base intervention packages

    The Impact of Histological Subtype on the Incidence, Timing, and Patterns of Recurrence in Patients with Renal Cell Carcinoma After Surgery-Results from RECUR Consortium

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    Background: Current follow-up strategies for patients with renal cell carcinoma (RCC) after curative surgery rely mainly on risk models and the treatment delivered, regardless of the histological subtype. Objective: To determine the impact of RCC histological subtype on recurrence and to examine the incidence, pattern, and timing of recurrences to improve follow-up recommendations. Design, setting, and participants: This study included consecutive patients treated surgically with curative intention (ie, radical and partial nephrectomy) for non-metastatic RCC (cT1-4, M0) between January 2006 and December 2011 across 15 centres from 10 countries, as part of the euRopEan association of urology renal cell carcinoma guidelines panel Collaborative multicenter consortium for the studies of follow-Up and recurrence patterns in Radically treated renal cell carcinoma patients (RECUR) database project. Outcome measurements and statistical analysis: The impact of histological subtype (ie, clear cell RCC [ccRCC], papillary RCC [pRCC], and chromophobe RCC [chRCC]) on recurrence-free survival (RFS) was assessed via univariate and multivariate analyses, adjusting for potential interactions with important variables (stage, grade, risk score, etc.) Patterns of recurrence for all histological subtypes were compared according to recurrence site and risk criteria. Results and limitations: Of the 3331 patients, 62.2% underwent radical nephrectomy and 37.8% partial nephrectomy. A total of 2565 patients (77.0%) had ccRCC, 535 (16.1%) had pRCC, and 231 (6.9%) had chRCC. The median postoperative follow-up period was 61.7 (interquartile range: 47-83) mo. Patients with ccRCC had significantly poorer 5-yr RFS than patients with pRCC and chRCC (78% vs 86% vs 91%, p = 0.001). The most common sites of recurrence for ccRCC were the lung and bone. Intermediate-/high-risk pRCC patients had an increased rate of lymphatic recurrence, both mediastinal and retroperitoneal, while recurrence in chRCC was rare (8.2%), associated with higher stage and positive margins, and predominantly in the liver and bone. Limitations include the retrospective nature of the study. Conclusions: The main histological subtypes of RCC exhibit a distinct pattern and dynamics of recurrence. Results suggest that intermediate- to high-risk pRCC may benefit from cross-sectional abdominal imaging every 6 mo until 2 yr after surgery, while routine imaging might be abandoned for chRCC except for abdominal computed tomography in patients with advanced tumour stage or positive margins. Patient summary: In this analysis of a large database from 15 countries around Europe, we found that the main histological subtypes of renal cell carcinoma have a distinct pattern and dynamics of recurrence. Patients should be followed differently according to subtype and risk score. (C) 2020 Published by Elsevier B.V. on behalf of European Association of Urology.Peer reviewe

    An effective theory for jet propagation in dense QCD matter: jet broadening and medium-induced bremsstrahlung

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    Two effects, jet broadening and gluon bremsstrahlung induced by the propagation of a highly energetic quark in dense QCD matter, are reconsidered from effective theory point of view. We modify the standard Soft Collinear Effective Theory (SCET) Lagrangian to include Glauber modes, which are needed to implement the interactions between the medium and the collinear fields. We derive the Feynman rules for this Lagrangian and show that it is invariant under soft and collinear gauge transformations. We find that the newly constructed theory SCETG_{\rm G} recovers exactly the general result for the transverse momentum broadening of jets. In the limit where the radiated gluons are significantly less energetic than the parent quark, we obtain a jet energy-loss kernel identical to the one discussed in the reaction operator approach to parton propagation in matter. In the framework of SCETG_{\rm G} we present results for the fully-differential bremsstrahlung spectrum for both the incoherent and the Landau-Pomeranchunk-Migdal suppressed regimes beyond the soft-gluon approximation. Gauge invariance of the physics results is demonstrated explicitly by performing the calculations in both the light-cone and covariant RξR_{\xi} gauges. We also show how the process-dependent medium-induced radiative corrections factorize from the jet production cross section on the example of the quark jets considered here.Comment: 52 pages, 15 pdf figures, as published in JHE

    Novel gene expression responses in the ovine abomasal mucosa to infection with the gastric nematode Teladorsagia circumcincta

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    Infection of sheep with the gastric nematode Teladorsagia circumcincta results in distinct Th2-type changes in the mucosa, including mucous neck cell and mast cell hyperplasia, eosinophilia, recruitment of IgA/IgE producing cells and neutrophils, altered T-cell subsets and mucosal hypertrophy. To address the protective mechanisms generated in animals on previous exposure to this parasite, gene expression profiling was carried out using samples of abomasal mucosa collected pre- and post- challenge from animals of differing immune status, using an experimental model of T. circumcincta infection. Recently developed ovine cDNA arrays were used to compare the abomasal responses of sheep immunised by trickle infection with worm-naïve sheep, following a single oral challenge of 50 000 T. circumcincta L3. Key changes were validated using qRT-PCR techniques. Immune animals demonstrated highly significant increases in levels of transcripts normally associated with cytotoxicity such as granulysin and granzymes A, B and H, as well as mucous-cell derived transcripts, predominantly calcium-activated chloride channel 1 (CLCA1). Challenge infection also induced up-regulation of transcripts potentially involved in initiating or modulating the immune response, such as heat shock proteins, complement factors and the chemokine CCL2. In contrast, there was marked infection-associated down-regulation of gene expression of members of the gastric lysozyme family. The changes in gene expression levels described here may reflect roles in direct anti-parasitic effects, immuno-modulation or tissue repair. (Funding; DEFRA/SHEFC (VT0102) and the BBSRC (BB/E01867X/1))
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