137 research outputs found

    Participation of the Melanocortin-1 Receptor in the UV Control of Pigmentation

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    The cloning of the melanocortin-1 receptor (MC1R) gene from human melanocytes and the demonstration that these cells respond to the melanocortins α-melanocyte stimulating hormone (α-MSH) and adrenocorticotropic hormone (ACTH) with increased proliferation and melanogenesis have renewed the interest in investigation the physiological role of these hormones in regulating human pigmentation. α-Melanocyte stimulating hormone and ACTH are both synthesized in the human epidermis, and their synthesis is upregulated by exposure to ultraviolet radiation (UVR). Activation of the MC1R by ligand binding results in stimulation of cAMP formation, which is a principal mechanism for inducing melanogenesis. The increase in cAMP is required for the pigmentary response of human melanocytes to UVR, and for allowing them to overcome the UVR-induced G1 arrest. Treatment of human melanocytes with α-MSH increases eumelanin synthesis, an effect that is expected to enhance photoprotection of the skin. Population studies have revealed more than 20 allelic variants of the MC1R gene. Some of these variants are overexpressed in individuals with skin type I or II, red hair, and poor tanning ability. Future studies will aim at further exploration of the role of these variants in MC1R function, and in determining constitutive human pigmentation, the response to sun exposure, and possibly the susceptibility to skin cancer

    Carotid artery intima-media thickness in polycystic ovary syndrome: a systematic review and meta-analysis

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    Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder associated with cardiovascular disease (CVD) risk factors and metabolic disturbances. This systematic review and meta-analysis was conducted to determine whether carotid intima-media thickness (CIMT), a marker of subclinical atherosclerosis, is higher in women with PCOS compared with women without PCOS

    Developing a community facilitator-led participatory learning and action women's group intervention to improve infant feeding, care and dental hygiene practices in South Asian infants: NEON programme

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    INTRODUCTION: The Nurture Early for Optimal Nutrition (NEON) study is a multiphase project that aims to optimize feeding, care and dental hygiene practices in South Asian children <2 years in East London, United Kingdom. The multiphase project uses a participatory learning and action (PLA) approach facilitated by a multilingual community facilitator. In this paper, we elaborate on the process and results of the Intervention Development Phase in the context of the wider NEON programme. METHODS: Qualitative community-based participatory intervention codevelopment and adaptation. SETTING: Community centres in East London and online (Zoom) meetings and workshops. PARTICIPANTS: In total, 32 participants registered to participate in the Intervention Development Phase. Four Intervention Development workshops were held, attended by 25, 17, 20 and 20 participants, respectively. RESULTS: Collaboratively, a culturally sensitive NEON intervention package was developed consisting of (1) PLA group facilitator manual, (2) picture cards detailing recommended and nonrecommended feeding, care and dental hygiene practices with facilitators/barriers to uptake as well as solutions to address these, (3) healthy infant cultural recipes, (4) participatory Community Asset Maps and (5) list of resources and services supporting infant feeding, care and dental hygiene practices. CONCLUSION: The Intervention Development Phase of the NEON programme demonstrates the value of a collaborative approach between researchers, community facilitators and the target population when developing public health interventions. We recommend that interventions to promote infant feeding, care and dental hygiene practices should be codeveloped with communities. Recognizing and taking into account both social and cultural norms may be of particular value for infants from ethnically diverse communities to develop interventions that are both effective in and accepted by these communities. PATIENT AND PUBLIC INVOLVEMENT AND ENGAGEMENT: Considerable efforts were placed on Patient/Participant and Public Involvement and Engagement. Five community facilitators were identified, each of which represented one ethnic/language group: (i) Bangladeshi/Bengali and Sylheti, (ii) Pakistani/Urdu, (iii) Indian/Gujrati, (iv) Indian/Punjabi and (v) Sri Lankan/Tamil. The community facilitators were engaged in every step of the study, from the initial drafting of the protocol and study design to the Intervention Development and refinement of the NEON toolkit, as well as the publication and dissemination of the study findings. More specifically, their role in the Intervention Development Phase of the NEON programme was to: 1. Support the development of the study protocol, information sheets and ethics application. 2. Ensure any documents intended for community members are clear, appropriate and sensitively worded. 3. Develop strategies to troubleshoot any logistical challenges of project delivery, for example, recruitment shortfalls. 4. Contribute to the writing of academic papers, in particular reviewing and revising drafts. 5. Develop plain language summaries and assist in dissemination activities, for example, updates on relevant websites. 6. Contribute to the development of the NEON intervention toolkit and recruitment of the community members. 7. Attend and contribute to Intervention Development workshops, ensuring the participant's voices were the focus of the discussion and workshop outcomes

    Software engineering for self-adaptive systems:research challenges in the provision of assurances

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    The important concern for modern software systems is to become more cost-effective, while being versatile, flexible, resilient, dependable, energy-efficient, customisable, configurable and self-optimising when reacting to run-time changes that may occur within the system itself, its environment or requirements. One of the most promising approaches to achieving such properties is to equip software systems with self-managing capabilities using self-adaptation mechanisms. Despite recent advances in this area, one key aspect of self-adaptive systems that remains to be tackled in depth is the provision of assurances, i.e., the collection, analysis and synthesis of evidence that the system satisfies its stated functional and non-functional requirements during its operation in the presence of self-adaptation. The provision of assurances for self-adaptive systems is challenging since run-time changes introduce a high degree of uncertainty. This paper on research challenges complements previous roadmap papers on software engineering for self-adaptive systems covering a different set of topics, which are related to assurances, namely, perpetual assurances, composition and decomposition of assurances, and assurances obtained from control theory. This research challenges paper is one of the many results of the Dagstuhl Seminar 13511 on Software Engineering for Self-Adaptive Systems: Assurances which took place in December 2013

    Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at √s=8 TeV

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    The top-antitop quark (t (t) over bar) production cross section is measured in proton-proton collisions at root s = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 fb(-1). The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model

    Software Engineering for Self-Adaptive Systems: A second Research Roadmap

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    The goal of this roadmap paper is to summarize the state of-the-art and identify research challenges when developing, deploying and managing self-adaptive software systems. Instead of dealing with a wide range of topics associated with the field, we focus on four essential topics of self-adaptation: design space for adaptive solutions, processes, from centralized to decentralized control, and practical run-time verification and validation. For each topic, we present an overview, suggest future directions, and focus on selected challenges. This paper complements and extends a previous roadmap on software engineering for self-adaptive systems published in 2009 covering a different set of topics, and reflecting in part on the previous paper. This roadmap is one of the many results of the Dagstuhl Seminar 10431 on Software Engineering for Self-Adaptive Systems, which took place in October 2010

    The p53 Inhibitor MDM2 Facilitates Sonic Hedgehog-Mediated Tumorigenesis and Influences Cerebellar Foliation

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    Disruption of cerebellar granular neuronal precursor (GNP) maturation can result in defects in motor coordination and learning, or in medulloblastoma, the most common childhood brain tumor. The Sonic Hedgehog (Shh) pathway is important for GNP proliferation; however, the factors regulating the extent and timing of GNP proliferation, as well as GNP differentiation and migration are poorly understood. The p53 tumor suppressor has been shown to negatively regulate the activity of the Shh effector, Gli1, in neural stem cells; however, the contribution of p53 to the regulation of Shh signaling in GNPs during cerebellar development has not been determined. Here, we exploited a hypomorphic allele of Mdm2 (Mdm2puro), which encodes a critical negative regulator of p53, to alter the level of wild-type MDM2 and p53 in vivo. We report that mice with reduced levels of MDM2 and increased levels of p53 have small cerebella with shortened folia, reminiscent of deficient Shh signaling. Indeed, Shh signaling in Mdm2-deficient GNPs is attenuated, concomitant with decreased expression of the Shh transducers, Gli1 and Gli2. We also find that Shh stimulation of GNPs promotes MDM2 accumulation and enhances phosphorylation at serine 166, a modification known to increase MDM2-p53 binding. Significantly, loss of MDM2 in Ptch1+/− mice, a model for Shh-mediated human medulloblastoma, impedes cerebellar tumorigenesis. Together, these results place MDM2 at a major nexus between the p53 and Shh signaling pathways in GNPs, with key roles in cerebellar development, GNP survival, cerebellar foliation, and MB tumorigenesis

    Patients' experience of shoulder disorders

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    Objectives: To describe the experiences (including symptoms and perceived impacts on daily living) of people with a shoulder disorder. Methods: Systematic review of qualitative studies. We searched for eligible qualitative studies indexed in Ovid MEDLINE, Ovid Embase, CINAHL (EBSCO), SportDiscus (EBSCO) and Ovid PsycINFO up until November 2017. Two authors independently screened studies for inclusion, appraised their methodological quality using the Critical Appraisal Skills Programme checklist, used thematic synthesis methods to generate themes describing the experiences reported by participants and assessed the confidence in the findings using the Grading of Recommendations Assessment, Development and Evaluation Confidence in Evidence fro

    Design and implementation of the international genetics and translational research in transplantation network

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    Sex differences in dementia risk and risk factors: Individual‐participant data analysis using 21 cohorts across six continents from the COSMIC consortium

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    Introduction: Sex differences in dementia risk, and risk factor (RF) associations with dementia, remain uncertain across diverse ethno‐regional groups. Methods: A total of 29,850 participants (58% women) from 21 cohorts across six continents were included in an individual participant data meta‐analysis. Sex‐specific hazard ratios (HRs), and women‐to‐men ratio of hazard ratios (RHRs) for associations between RFs and all‐cause dementia were derived from mixed‐effect Cox models. Results: Incident dementia occurred in 2089 (66% women) participants over 4.6 years (median). Women had higher dementia risk (HR, 1.12 [1.02, 1.23]) than men, particularly in low‐ and lower‐middle‐income economies. Associations between longer education and former alcohol use with dementia risk (RHR, 1.01 [1.00, 1.03] per year, and 0.55 [0.38, 0.79], respectively) were stronger for men than women; otherwise, there were no discernible sex differences in other RFs. Discussion: Dementia risk was higher in women than men, with possible variations by country‐level income settings, but most RFs appear to work similarly in women and men
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