1,979 research outputs found

    Maximum Power Efficiency and Criticality in Random Boolean Networks

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    Random Boolean networks are models of disordered causal systems that can occur in cells and the biosphere. These are open thermodynamic systems exhibiting a flow of energy that is dissipated at a finite rate. Life does work to acquire more energy, then uses the available energy it has gained to perform more work. It is plausible that natural selection has optimized many biological systems for power efficiency: useful power generated per unit fuel. In this letter we begin to investigate these questions for random Boolean networks using Landauer's erasure principle, which defines a minimum entropy cost for bit erasure. We show that critical Boolean networks maximize available power efficiency, which requires that the system have a finite displacement from equilibrium. Our initial results may extend to more realistic models for cells and ecosystems.Comment: 4 pages RevTeX, 1 figure in .eps format. Comments welcome, v2: minor clarifications added, conclusions unchanged. v3: paper rewritten to clarify it; conclusions unchange

    Validation of the individualised neuromuscular quality of life for the USA with comparison of the impact of muscle disease on those living in USA versus UK

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    <p>Abstract</p> <p>Background</p> <p>The Individualised Neuromuscular Quality of Life (INQoL) questionnaire is a published muscle disease specific measure of QoL that has been validated using both qualitative and quantitative methods in a United Kingdom population of adults with muscle disease. If INQoL is to be used in other countries it needs to be linguistically and culturally validated for those countries. It may be important to understand any cultural differences in how patients rate their QoL when applying QoL measures in multi-national clinical trials.</p> <p>Methods</p> <p>We conducted a postal survey of QoL issues in US adults with muscle disease using an agreed translation, from UK to US English, of the same questionnaire as was used in the original construction of INQoL. This questionnaire included an opportunity for free text comments on any aspects of QoL that might not have been covered by the questionnaire. We examined the responses using both quantitative and qualitative approaches. The frequency of the responses in US versus UK populations was compared using appropriate correlation tests and Rasch analysis. A phenomenological approach was used to guide the qualitative analysis and facilitate the exploration of patients' perceptions and experiences.</p> <p>Results</p> <p>The US survey received 333 responses which were compared with 251 UK survey responses.</p> <p>We found that INQoL domains covered all the issues raised by US subjects with no additional domains required. The experiences of those with muscle disease were remarkably similar in the US and UK but there were differences related to the impact of muscle disease on relationships and on employment which was greater for those living in the United States. The greater impact on employment was associated with a higher importance rating given to employment in the US. This may reflect the lower level of financial support for those who are unemployed, and the loss of employment related health benefits.</p> <p>Conclusions</p> <p>INQoL is appropriate for use in US population but there may be differences in the importance that US subject attach to certain aspects of QoL that could be the basis for further study.</p> <p>If these differences are confirmed then this may have implications for the interpretation of QoL outcomes in multi-national trials.</p

    Endomicroscopic and transcriptomic analysis of impaired barrier function and malabsorption in environmental enteropathy

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    Introduction: Environmental enteropathy (EE) is associated with growth failure, micronutrient malabsorption and impaired responses to oral vaccines. We set out to define cellular mechanisms of impaired barrier function in EE and explore protective mechanisms. Methods: We studied 49 adults with environmental enteropathy in Lusaka, Zambia using confocal laser endomicroscopy (CLE); histology, immunohistochemistry and mRNA sequencing of small intestinal biopsies; and correlated these with plasma lipopolysaccharide (LPS) and a zinc uptake test. Results: CLE images (median 134 for each study) showed virtually ubiquitous small intestinal damage. Epithelial defects, imaged by histology and claudin 4 immunostaining, were predominantly seen at the tips of villi and corresponded with leakage imaged in vivo by CLE. In multivariate analysis, circulating log-transformed LPS was correlated with cell shedding events (β = 0.83; P = 0.035) and with serum glucagon-like peptide-2 (β = -0.13; P = 0.007). Zinc uptake from a test dose of 25mg was attenuated in 30/47 (64%) individuals and in multivariate analysis was reduced by HIV, but positively correlated with GLP-2 (β = 2.72; P = 0.03). There was a U-shaped relationship between circulating LPS and villus surface area. Transcriptomic analysis identified 23 differentially expressed genes in severe enteropathy, including protective peptides and proteins. Conclusions: Confocal endomicroscopy, claudin 4 immunostaining and histology identify epithelial defects which are probably sites of bacterial translocation, in the presence of which increased epithelial surface area increases the burden of translocation. GLP 2 and other protective peptides may play an important role in mucosal protection in EE

    North: Volume Two

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    North Volume Two reflects our belief in photography as a relevant tool for exploring our ever-changing world. Whether in Preston, Liverpool, Berlin or Guangzhou the image-makers create a conversation with contemporary life as they endeavour to make their surroundings legible. In this second edition we continue North in the streets and spaces of the city. From contested sites of demolition, to new imaginaries formulated in the studio and in domestic, digital and social space, the volume is testament to how the urban endures as one of photography’s perennial objects of study. Like the first edition, We aim to highlight our commitment to everyday life as a meaningful arena for research and cultural production

    Art therapy, arts-based research and transitional stories of domestic violence and abuse

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    Visual imagery within qualitative research is an established method of gathering data that has parallels to the way in which images are used within art therapy. This paper explores how visual imagery was used to investigate women’s responses to domestic violence and abuse and examines how art therapy principles shaped the development and conducting of that research. Through the use of collage, participants created visual representations of their responses to experiences of domestic violence and abuse. The visual representations were, when combined with spoken words, created stories that reference the past, present and future. The stories created have been termed transitional stories of domestic violence. These stories show that the home has special significance for women as they transition away from domestic violence and plan for their future. The home becomes both a metaphorical and physical manifestation and container of hopes for a harmonious future that often incorporates the desire for the return to the idea of a complete family. This paper will present the findings of the arts-based research conducted, and consider the implications upon art therapy practice of those findings.N

    Bicycle Friendly Community Assessment Spring 2015

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    Completed by Cal Poly, San Luis Obispo City & Regional Planning students enrolled in a bicycle and pedestrian planning course (CRP 425), under the direction of Dr. William Riggs this report was designed to gather data in advance of the City of San Luis Obispo\u27s application to be a Bicycle Friendly Community. The report focuses on the key certification areas of Engineering, Education, Encouragement, Evaluation/Planning and Enforcement providing documentation for the City\u27s eventual application

    Initial recommendations for performing, benchmarking, and reporting single-cell proteomics experiments

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    Analyzing proteins from single cells by tandem mass spectrometry (MS) has become technically feasible. While such analysis has the potential to accurately quantify thousands of proteins across thousands of single cells, the accuracy and reproducibility of the results may be undermined by numerous factors affecting experimental design, sample preparation, data acquisition, and data analysis. Broadly accepted community guidelines and standardized metrics will enhance rigor, data quality, and alignment between laboratories. Here we propose best practices, quality controls, and data reporting recommendations to assist in the broad adoption of reliable quantitative workflows for single-cell proteomics.Comment: Supporting website: https://single-cell.net/guideline

    Rethinking Industrial Relations revisited

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    This article traces the origins and consequences of the book Rethinking Industrial Relations and then explores some of the conceptual and empirical issues raised since its publication

    Folic acid fortification and public health: Report on threshold doses above which unmetabolised folic acid appear in serum

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    BACKGROUND: All flour in the USA is fortified with folic acid at a level of 140 μg/100 g which is estimated to supply an extra 100 μg daily to the average diet. Some researchers have advocated that this be increased to double and even four times this amount. Based on previous research these higher levels are likely to lead to the appearance of unmetabolised vitamin in the circulation, which may have safety implications for sub-groups of the population. The UK and the Republic of Ireland will likely introduce mandatory fortification also in the next year or so. The aim of this study was to capture the short-term effect of folic acid fortification on unmetabolised folic acid in serum after chronic consumption of folic acid. METHODS: After pre-saturation with 400 μg folic acid supplements daily for 14-weeks, healthy folate replete adults (n = 20) consumed folic acid fortified bread, at three different levels (400 μg, 200 μg, 100 μg) over a period of one week each. The dose was administered in two-equal sized slices consumed at 09.00 hrs and 13.00 hrs. Serum samples for total folate and folic acid were collected at baseline, after 14-weeks of supplementation, and pre and post (at 1, 2, 3 and 4 hours) each dose tested. RESULTS: Unmetabolised folic acid was detected after the 14-week supplementation period. Folic acid was not detected in either the 200 μg or 100 μg (current US regime) doses tested but was present at the highest level (400 μg) tested. CONCLUSION: Our findings suggest that persons exposed to the current US fortification programme supplying an average of 100 μg per day or less are unlikely to have unmetabolised folic acid in serum. It also seems that daily consumption of the higher level of 200 μg or less is unlikely to be problematic. Increasing the level however to 400 μg on the other hand is likely to lead to unmetabolised folic acid appearance

    Optimized immunosuppression to prevent graft failure in renal transplant recipients with HLA antibodies (OuTSMART): a randomised controlled trial

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    Background: 3% of kidney transplant recipients return to dialysis annually upon allograft failure. Development of antibodies (Ab) against human leukocyte antigens (HLA) is a validated prognostic biomarker of allograft failure. We tested whether screening for HLA Ab, combined with an intervention to improve adherence and optimization of immunosuppression could prevent allograft failure. Methods: Prospective, open-labelled randomised biomarker-based strategy (hybrid) trial in 13 UK transplant centres [EudraCT (2012-004308-36) and ISRCTN (46157828)]. Patients were randomly allocated (1:1) to unblinded or double-blinded arms and screened every 8 months. Unblinded HLA Ab+ patients were interviewed to encourage medication adherence and had tailored optimisation of Tacrolimus, Mycophenolate mofetil and Prednisolone. The primary outcome was time to graft failure in an intention to treat analysis. The trial had 80% power to detect a hazard ratio of 0.49 in donor specific antibody (DSA)+ patients. Findings: From 11/9/13 to 27/10/16, 5519 were screened for eligibility and 2037 randomised (1028 to unblinded care and 1009 to double blinded care). We identified 198 with DSA and 818 with non-DSA. Development of DSA, but not non-DSA was predictive of graft failure. HRs for graft failure in unblinded DSA+ and non-DSA+ groups were 1.54 (95% CI: 0.72 to 3.30) and 0.97 (0.54–1.74) respectively, providing no evidence of an intervention effect. Non-inferiority for the overall unblinded versus blinded comparison was not demonstrated as the upper confidence limit of the HR for graft failure exceeded 1.4 (1.02, 95% CI: 0.72 to 1.44). The only secondary endpoint reduced in the unblinded arm was biopsy-proven rejection. Interpretation: Intervention to improve adherence and optimize immunosuppression does not delay failure of renal transplants after development of DSA. Whilst DSA predicts increased risk of allograft failure, novel interventions are needed before screening can be used to direct therapy
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