1,156 research outputs found

    The effects of ageing and nutritional status on voluntary muscle function tests using human adductor pollicis muscle

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    Maximum voluntary force and cross-sectional area (CSA) of adductor pollicis muscle have been measured to examine the weakness associated with ageing and that associated with subnutrition, in six groups of subjects: 1) fit young, 2) fit elderly, 3) subnourished young, 4) elderly hip fracture patients, 5) post-menopausal women not receiving hormone replacement therapy, 6) post-menopausal women on hormone replacement therapy. In normally nourished young adults no sex difference was found in the force produced for a given cross-sectional area of adductor pollicis muscle. Likewise subnourished young adults produced the same force/CSA as their normally nourished counterparts. Pre-menopausal women and the subnourished produced lower forces but this was because they had smaller muscles. In contrast the elderly had a lower force/CSA. This reduction was particularly marked in those with osteoporotic fractures. As women are more prone to these fractures we predicted that a sex difference might be found with ageing and we have demonstrated this to be in the time-course of the decline in force/CSA. In women the decline was clearly related to the menopause. In men it was more gradual and its onset later. Possible causes for a low force/CSA are: 1) incomplete muscle activation - the force is not maximal. This was excluded in our weak elderly subjects using twitch interpolation. 2) replacement of the muscle with non-contractile tissue - the CSA is artefactually large. This was excluded by showing that the force obtained during stretch of the actively contracting adductor pollicis muscle is greater as a proportion of the isometric force in weak post-menopausal women than in young adults. This therefore suggests that the low force/CSA in these subjects is due to: 3) a change in cross-bridge function. Finally we found that the force/CSA in post-menopausal women is maintained by oestrogen replacement therapy suggesting that the change in cross-bridge function is hormonally mediated

    Evaluation of the cutaneous microbiome in psoriasis

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    Psoriasis, a highly prevalent disease of humans of unknown cause, is a chronic inflammatory disorder primarily involving skin, with distinctive clinical characteristics. With the newly developed tools that facilitate microbiome research, it now is possible to assess whether the cutaneous microbiome plays a role in the pathogenesis of this disorder. Preliminary data from our studies suggest that the cutaneous microbiome in psoriasis is complex and possibly different from normal. To deal with this complexity, we propose to examine the cutaneous microbiome in relation to psoriasis with explorations at several taxonomic and informatic levels. Our overall objective is to examine how changes in the normal cutaneous microbiome contributes to the pathogenesis of psoriasis. Since causality is complex and often difficult to prove, our overall hypothesis is that there are alterations in the cutaneous microbiome in areas of skin affected by psoriasis in comparison with the range observed in clinically unaffected areas, or in healthy persons. We also hypothesize that the characteristics of the microbiome may affect clinical responses to the immunomodulatory agents used to treat psoriasis. An alternative hypothesis is that effective treatment of psoriasis with systemic immunomodulatory agents will not substantially affect the disordered microbial ecosystem. Such observations would provide evidence for the roles of the microbiota in this disorder. Since an important consideration in microbiome research is the optimal level (e.g. phylum, genus, species, strain, gene) at which to examine a scientific question, and we are not yet certain what are the optimal levels for psoriasis, this also will be examined. Our studies of psoriasis should allow development of both approaches and tools that will have general utility for microbiome research. To test our hypothesis, we propose the following specific aims: 1. To understand the cutaneous microbiome species composition overlaying psoriatic lesions; 2. To investigate differences in metagenome content for psoriatic lesions compared to normal skin; 3. To identify differences in the transcriptional profiles of the microbiome and the host between normal skin and psoriatic lesions using high-throughput sequencing; and 4. To estimate the effects of systemic immunomodulatory therapy for psoriasis on microbiome composition. In total, these studies should help us understand the role of the microbiome in psoriasis pathogenesis

    GenMAPP 2: New features and resources for pathway analysis

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    BACKGROUND: Microarray technologies have evolved rapidly, enabling biologists to quantify genome-wide levels of gene expression, alternative splicing, and sequence variations for a variety of species. Analyzing and displaying these data present a significant challenge. Pathway-based approaches for analyzing microarray data have proven useful for presenting data and for generating testable hypotheses. RESULTS: To address the growing needs of the microarray community we have released version 2 of Gene Map Annotator and Pathway Profiler (GenMAPP), a new GenMAPP database schema, and integrated resources for pathway analysis. We have redesigned the GenMAPP database to support multiple gene annotations and species as well as custom species database creation for a potentially unlimited number of species. We have expanded our pathway resources by utilizing homology information to translate pathway content between species and extending existing pathways with data derived from conserved protein interactions and coexpression. We have implemented a new mode of data visualization to support analysis of complex data, including time-course, single nucleotide polymorphism (SNP), and splicing. GenMAPP version 2 also offers innovative ways to display and share data by incorporating HTML export of analyses for entire sets of pathways as organized web pages. CONCLUSION: GenMAPP version 2 provides a means to rapidly interrogate complex experimental data for pathway-level changes in a diverse range of organisms

    A Phase I Trial of Aminolevulinic Acid-Photodynamic Therapy for Treatment of Oral Leukoplakia

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    Background Photodynamic therapy with aminolevulinic acid (ALA PDT) for oral leukoplakia has shown promising effects in regression of oral leukoplakia. Although ALA has been extensively studied and is an ideal photosensitizer, the optimal light dose for treatment of oral leukoplakia has not been determined. We conducted a phase I study to determine MTD and DLT of PDT in patients treated with ALA for leukoplakia. Methods Patients with histologically confirmed oral leukoplakia received a single treatment of ALA PDT in cohorts with escalating doses of light (585 nm). Clinical, histologic, and biologic markers were assessed. Results Analysis of 11 participants is reported. No significant toxicity from ALA PDT was observed in patients who received ALA with a light dose of up to 4 J/cm2. One participant experienced transient grade 3 transaminase elevation due to ALA. One participant had a partial clinical response 3 months after treatment. Biologic mucosal risk markers showed no significant associations. Determination of MTD could not be accomplished within a feasible timeframe for completion of the study. Conclusions ALA PDT could be safely administered with a light dose up to 4 J/cm2 and demonstrated activity. Larger studies are needed to fully elucidate the MTD and efficacy of ALA-PDT

    Sustainable intensification for a larger global rice bowl

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    Future rice systems must produce more grain while minimizing the negative environmental impacts. A key question is how to orient agricultural research & development (R&D) programs at national to global scales to maximize the return on investment. Here we assess yield gap and resource-use efficiency (including water, pesticides, nitrogen, labor, energy, and associated global warming potential) across 32 rice cropping systems covering half of global rice harvested area. We show that achieving high yields and high resource-use efficiencies are not conflicting goals. Most cropping systems have room for increasing yield, resource-use efficiency, or both. In aggregate, current total rice production could be increased by 32%, and excess nitrogen almost eliminated, by focusing on a relatively small number of cropping systems with either large yield gaps or poor resource-use efficiencies. This study provides essential strategic insight on yield gap and resource-use efficiency for prioritizing national and global agricultural R&D investments to ensure adequate rice supply while minimizing negative environmental impact in coming decades

    Efficiency and safety of varying the frequency of whole blood donation (INTERVAL): a randomised trial of 45 000 donors

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    Background: Limits on the frequency of whole blood donation exist primarily to safeguard donor health. However, there is substantial variation across blood services in the maximum frequency of donations allowed. We compared standard practice in the UK with shorter inter-donation intervals used in other countries. Methods: In this parallel group, pragmatic, randomised trial, we recruited whole blood donors aged 18 years or older from 25 centres across England, UK. By use of a computer-based algorithm, men were randomly assigned (1:1:1) to 12-week (standard) versus 10-week versus 8-week inter-donation intervals, and women were randomly assigned (1:1:1) to 16-week (standard) versus 14-week versus 12-week intervals. Participants were not masked to their allocated intervention group. The primary outcome was the number of donations over 2 years. Secondary outcomes related to safety were quality of life, symptoms potentially related to donation, physical activity, cognitive function, haemoglobin and ferritin concentrations, and deferrals because of low haemoglobin. This trial is registered with ISRCTN, number ISRCTN24760606, and is ongoing but no longer recruiting participants. Findings: 45 263 whole blood donors (22 466 men, 22 797 women) were recruited between June 11, 2012, and June 15, 2014. Data were analysed for 45 042 (99·5%) participants. Men were randomly assigned to the 12-week (n=7452) versus 10-week (n=7449) versus 8-week (n=7456) groups; and women to the 16-week (n=7550) versus 14-week (n=7567) versus 12-week (n=7568) groups. In men, compared with the 12-week group, the mean amount of blood collected per donor over 2 years increased by 1·69 units (95% CI 1·59–1·80; approximately 795 mL) in the 8-week group and by 0·79 units (0·69–0·88; approximately 370 mL) in the 10-week group (p<0·0001 for both). In women, compared with the 16-week group, it increased by 0·84 units (95% CI 0·76–0·91; approximately 395 mL) in the 12-week group and by 0·46 units (0·39–0·53; approximately 215 mL) in the 14-week group (p<0·0001 for both). No significant differences were observed in quality of life, physical activity, or cognitive function across randomised groups. However, more frequent donation resulted in more donation-related symptoms (eg, tiredness, breathlessness, feeling faint, dizziness, and restless legs, especially among men [for all listed symptoms]), lower mean haemoglobin and ferritin concentrations, and more deferrals for low haemoglobin (p<0·0001 for each) than those observed in the standard frequency groups. Interpretation: Over 2 years, more frequent donation than is standard practice in the UK collected substantially more blood without having a major effect on donors' quality of life, physical activity, or cognitive function, but resulted in more donation-related symptoms, deferrals, and iron deficiency. Funding: NHS Blood and Transplant, National Institute for Health Research, UK Medical Research Council, and British Heart Foundation

    Introductory programming: a systematic literature review

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    As computing becomes a mainstream discipline embedded in the school curriculum and acts as an enabler for an increasing range of academic disciplines in higher education, the literature on introductory programming is growing. Although there have been several reviews that focus on specific aspects of introductory programming, there has been no broad overview of the literature exploring recent trends across the breadth of introductory programming. This paper is the report of an ITiCSE working group that conducted a systematic review in order to gain an overview of the introductory programming literature. Partitioning the literature into papers addressing the student, teaching, the curriculum, and assessment, we explore trends, highlight advances in knowledge over the past 15 years, and indicate possible directions for future research
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