263 research outputs found

    Assessment of total retinal blood flow using Doppler Fourier Domain Optical Coherence Tomography during systemic hypercapnia and hypocapnia.

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    The purpose of this study was to investigate changes in total retinal blood flow (RBF) using Doppler Fourier Domain Optical Coherence Tomography (Doppler FD-OCT) in response to the manipulation of systemic partial pressure of CO2 (PETCO2). Double circular Doppler blood flow scans were captured in nine healthy individuals (mean age ± standard deviation: 27.1 ± 4.1, six males) using the RTVue(™) FD-OCT (Optovue). PETCO2 was manipulated using a custom-designed computer-controlled gas blender (RespirAct(™)) connected to a sequential gas delivery rebreathing circuit. Doppler FD-OCT measurements were captured at baseline, during stages of hypercapnia (+5/+10/+15 mmHg PETCO2), return to baseline and during stages of hypocapnia (-5/-10/-15 mmHg PETCO2). Repeated measures analysis of variance (reANOVA) and Tukeys post hoc analysis were used to compare Doppler FD-OCT measurements between the various PETCO2 levels relative to baseline. The effect of PETCO2 on TRBF was also investigated using linear regression models. The average RBF significantly increased by 15% (P < 0.0001) with an increase in PETCO2 and decreased significantly by 10% with a decrease in PETCO2 (P = 0.001). Venous velocity significantly increased by 3.11% from baseline to extreme hypercapnia (P < 0.001) and reduced significantly by 2.01% at extreme hypocapnia (P = 0.012). No significant changes were found in the average venous area measurements under hypercapnia (P = 0.36) or hypocapnia (P = 0.40). Overall, increased and decreased PETCO2 values had a significant effect on RBF outcomes (P < 0.002). In healthy individuals, altered end-tidal CO2 levels significantly changed RBF as measured by Doppler FD-OCT

    Leadership and Change in Asia-Pacific: Where Does Political Will Come From?

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    We introduce this thematic issue by exploring the role of leadership in social and political change. In current times, the importance of leadership and choice has proved as important as ever. Leadership is often the critical variable separating success or failure, legitimacy and sustainability or collapse. This thematic issue explores a range of in-depth case studies across the Asia-Pacific region that help illustrate the critical elements of leadership. Collectively they demonstrate that leadership is best understood as a collective process involving motivated agents overcoming barriers to cooperation to form coalitions that have enough power, legitimacy and influence to transform institutions. Five themes emerge from the thematic issue as a whole: leadership is political; the centrality of gender relations; the need for a more critical localism; scalar politics; and the importance of understanding informal processes of leadership and social change

    Antimicrobial use practices and opinions of beef farmers in England and Wales

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    © British Veterinary Association. Background Limited research exists on antimicrobial use practices of beef farmers. This study aimed to investigate antimicrobial practices and perceptions of beef farmers in England and Wales, and identify drivers of higher antimicrobial use for treatment of bovine pneumonia. Methods A survey was sent out in 2017 to beef farmers in England and Wales who supply to two abattoirs. Descriptive statistics were used to summarise the data. A logistic regression model was built to determine factors associated with treating greater than 5 per cent of the predominant group in the herd with antimicrobials for pneumonia. Results There were a total of 171 useable responses. Most farmers reported using antimicrobials in less than 5 per cent of their herd for the treatment of common diseases. Most farmers (90 per cent) reported that they understood what antimicrobial resistance means, but only 55 per cent were aware of critically important antimicrobials and 9 per cent could name at least one critically important antimicrobial. Having a calf-rearing enterprise and not considering Johne's disease when buying in cattle were associated with using antimicrobials to treat pneumonia in greater than 5 per cent of the predominant group in the herd. Conclusion Self-reported antimicrobial use appears to be low in beef farms. However, some gaps in understanding aspects of antimicrobial stewardship by farmers were identified

    Finding the optimal background subtraction algorithm for EuroHockey 2015 video

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    Background subtraction is a classic step in a vision-based localization and tracking workflow. Previous studies have compared background subtraction algorithms on publicly available datasets; however comparisons were made only with manually optimized parameters. The aim of this research was to identify the optimal background subtraction algorithm for a set of field hockey videos captured at EuroHockey 2015. Particle Swarm Optimization was applied to find the optimal background subtraction algorithm. The objective function was the F-score, i.e. the harmonic mean of precision and recall. The precision and recall were calculated using the output of the background subtraction algorithm and gold standard labeled images. The training dataset consisted of 15 x 13 second field hockey video segments. The test data consisted of 5 x 13 second field hockey video segments. The video segments were chosen to be representative of the teams present at the tournament, the times of day the matches were played and the weather conditions experienced. Each segment was 960 pixels x 540 pixels and had 10 ground truth labeled frames. Eight commonly used background subtraction algorithms were considered. Results suggest that a background subtraction algorithm must use optimized parameters for a valid comparison of performance. Particle Swarm Optimization is an appropriate method to undertake this optimization. The optimal algorithm, Temporal Median, achieved an F-score of 0.791 on the test dataset, suggesting it generalizes to the rest of the video footage captured at EuroHockey 2015

    Reviews

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    The following publications have been reviewed by the mentioned authors;Supporting Science, Design and Technology in the Early Years - reviewed by Alan CrossDazzle Plus - reviewed by David FosterDesign and Bake - Wheat and Other Cereals - reviewed by Marion RutlandDesign and Technology and the Historic Environment - reviewed by Michael LawrenceThe Millennium Train - reviewed by Chris SnellGCSE Food Technology for OCR: Pupil Book and Teacher's Resource File - reviewed by Roy BallamRaising Achievement in Design and Technology: Resistant Materials - reviewed by Roman M. GawelThe Possibilities Schools - A Blueprint for Education - reviewed by Andy BreckonKites Resource Pack: Key Stage 3 Design and Technology - reviewed by Mark HudsonICT and the Learning Revolution - reviewed by Les Porte

    Graphene Oxide Reduces the Hydrolytic Degradation in Polyamide-11

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    Graphene oxide (GO) was incorporated into polyamide-11 (PA11) via in-situ polymerization. The GO-PA11 nano-composite had elevated resistance to hydrolytic degradation. At a loading of 1 mg/g, GO to PA11, the accelerated aging equilibrium molecular weight of GO-PA11 was higher (33 and 34 kg/mol at 100 and 120 C, respectively) compared to neat PA11 (23 and 24 kg/mol at 100 and 120 C, respectively). Neat PA11 had hydrolysis rate constants (kH) of 2.8 and 12 ( 10(exp -2) day(exp -1)) when aged at 100 and 120 C, respectively, and re-polymerization rate constants (kP) of 5.0 and 23 ( 10(exp -5) day(exp -1)), respectively. The higher equilibrium molecular weight for GO-PA11 loaded at 1 mg/g was the result of a decreased kH, 1.8 and 4.5 ( 10(exp -2) day(exp -1)), and an increased kP, 10 and 17 ( 10(exp -5) day(exp -1)) compared with neat PA11 at 100 and 120 C, respectively. The decreased rate of degradation and resulting 40% increased equilibrium molecular weight of GO-PA11 was attributed to the highly asymmetric planar GO nano-sheets that inhibited the molecular mobility of water and the polymer chain. The crystallinity of the polymer matrix was similarly affected by a reduction in chain mobility during annealing due to the GO nanoparticles' chemistry and highly asymmetric nano-planar sheet structure

    Characteristics of effective collaborative care for treatment of depression: a systematic review and meta-regression of 74 randomised controlled trials

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    This is a freely-available open access publication. Please cite the published version which is available via the DOI link in this record.BACKGROUND: Collaborative care is a complex intervention based on chronic disease management models and is effective in the management of depression. However, there is still uncertainty about which components of collaborative care are effective. We used meta-regression to identify factors in collaborative care associated with improvement in patient outcomes (depressive symptoms) and the process of care (use of anti-depressant medication). METHODS AND FINDINGS: Systematic review with meta-regression. The Cochrane Collaboration Depression, Anxiety and Neurosis Group trials registers were searched from inception to 9th February 2012. An update was run in the CENTRAL trials database on 29th December 2013. Inclusion criteria were: randomised controlled trials of collaborative care for adults ≥18 years with a primary diagnosis of depression or mixed anxiety and depressive disorder. Random effects meta-regression was used to estimate regression coefficients with 95% confidence intervals (CIs) between study level covariates and depressive symptoms and relative risk (95% CI) and anti-depressant use. The association between anti-depressant use and improvement in depression was also explored. Seventy four trials were identified (85 comparisons, across 21,345 participants). Collaborative care that included psychological interventions predicted improvement in depression (β coefficient -0.11, 95% CI -0.20 to -0.01, p = 0.03). Systematic identification of patients (relative risk 1.43, 95% CI 1.12 to 1.81, p = 0.004) and the presence of a chronic physical condition (relative risk 1.32, 95% CI 1.05 to 1.65, p = 0.02) predicted use of anti-depressant medication. CONCLUSION: Trials of collaborative care that included psychological treatment, with or without anti-depressant medication, appeared to improve depression more than those without psychological treatment. Trials that used systematic methods to identify patients with depression and also trials that included patients with a chronic physical condition reported improved use of anti-depressant medication. However, these findings are limited by the observational nature of meta-regression, incomplete data reporting, and the use of study aggregates.NIH

    Interleukin-33 regulates metabolic reprogramming of the retinal pigment epithelium in response to immune stressors

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    It remains unresolved how retinal pigment epithelial cell metabolism is regulated following immune activation to maintain retinal homeostasis and retinal function. We exposed retinal pigment epithelium (RPE) to several stress signals, particularly Toll-like receptor stimulation, and uncovered an ability of RPE to adapt their metabolic preference on aerobic glycolysis or oxidative glucose metabolism in response to different immune stimuli. We have identified interleukin-33 (IL-33) as a key metabolic checkpoint that antagonizes the Warburg effect to ensure the functional stability of the RPE. The identification of IL-33 as a key regulator of mitochondrial metabolism suggests roles for the cytokine that go beyond its extracellular “alarmin” activities. IL-33 exerts control over mitochondrial respiration in RPE by facilitating oxidative pyruvate catabolism. We have also revealed that in the absence of IL-33, mitochondrial function declined and resultant bioenergetic switching was aligned with altered mitochondrial morphology. Our data not only shed new light on the molecular pathway of activation of mitochondrial respiration in RPE in response to immune stressors but also uncover a potentially novel role of nuclear intrinsic IL-33 as a metabolic checkpoint regulator

    Optimising breast cancer screening reading: blinding the second reader to the first reader's decisions.

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    OBJECTIVES: In breast cancer screening, two readers separately examine each woman's mammograms for signs of cancer. We examined whether preventing the two readers from seeing each other's decisions (blinding) affects behaviour and outcomes. METHODS: This cohort study used data from the CO-OPS breast-screening trial (1,119,191 women from 43 screening centres in England) where all discrepant readings were arbitrated. Multilevel models were fitted using Markov chain Monte Carlo to measure whether reader 2 conformed to the decisions of reader 1 when they were not blinded, and the effect of blinding on overall rates of recall for further tests and cancer detection. Differences in positive predictive value (PPV) were assessed using Pearson's chi-squared test. RESULTS: When reader 1 recalls, the probability of reader 2 also recalling was higher when not blinded than when blinded, suggesting readers may be influenced by the other's decision. Overall, women were less likely to be recalled when reader 2 was blinded (OR 0.923; 95% credible interval 0.864, 0.986), with no clear pattern in cancer detection rate (OR 1.029; 95% credible interval 0.970, 1.089; Bayesian p value 0.832). PPV was 22.1% for blinded versus 20.6% for not blinded (p < 0.001). CONCLUSIONS: Our results suggest that when not blinded, reader 2 is influenced by reader 1's decisions to recall (alliterative bias) which would result in bypassing arbitration and negate some of the benefits of double-reading. We found a relationship between blinding the second reader and slightly higher PPV of breast cancer screening, although this analysis may be confounded by other centre characteristics. KEY POINTS: • In Europe, it is recommended that breast screening mammograms are analysed by two readers but there is little evidence on the effect of 'blinding' the readers so they cannot see each other's decisions. • We found evidence that when the second reader is not blinded, they are more likely to agree with a recall decision from the first reader and less likely to make an independent judgement (alliterative error). This may reduce overall accuracy through bypassing arbitration. • This observational study suggests an association between blinding the second reader and higher positive predictive value of screening, but this may be confounded by centre characteristics

    Association of lameness and mastitis with return-to-service oestrus detection in the dairy cow

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    © British Veterinary Association 2019. No commercial re-use. See rights and permissions. Published by BMJ. Oestrus detection is an important part of maintaining efficient reproductive performance in dairy herds. Both lameness and mastitis are common diseases of dairy cows that may impact oestrus detection. A set of data from 28 herds identified as having good recording of clinical mastitis and lameness incidents was used for the study. Logistic regression was used to identify associations between disease episodes within 100 days of insemination and changes in the probability of reinsemination at either 18-24 or 19-26 days after an unsuccessful insemination. Population attributable risk was calculated to understand the impact these diseases may have at a herd level. Lameness 0-28 days after the first insemination of the interval decreased the odds of a reinsemination at an appropriate time by approximately 20 per cent. Clinical mastitis 1-28 days prior to the first insemination of the interval increased the odds of reinsemination at the expected time by approximately 20 per cent. The associations were similar for either interservice interval outcome. Population attributable risk suggested that the effect of these diseases on the probability of reinsemination at the expected time at a population level would likely be extremely small
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