2,699 research outputs found

    The reliability, validity and trainability of running economy in trained distance runners

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    Running economy is well established as a primary determinant of endurance running performance. However, there is a lack of clarity about the preferred measurement of running economy, its primary limiting factors and the most robust methods enhance running economy in highly trained athletes. Therefore, this thesis investigated the running economy of highly trained runners, exploring the reliability and validity of measures of running economy to deduce its most appropriate quantification, the application of innovative methods to enhance our understanding of an athlete s running economy, and a novel training method to enhance running economy. Chapter 3 revealed that energy cost and oxygen cost were shown to provide similarly high levels of reliability (typical error of measurement ~3%) for highly trained endurance runners when assessed using a short-duration incremental submaximal exercise protocol. In chapter 4, the analysis of a large cohort of highly trained endurance runners revealed that energy cost increased in a stepwise manner with increments in running speed (P<0.001), however oxygen cost remained consistent (P=0.54) across running speed; indicating that oxygen cost might not be an appropriate measure of running economy. Chapter 5 demonstrated that the inter-individual variation in the magnitude of changes in energy cost between different gradients (i.e. from flat running to uphill/downhill running) in highly trained runners was low. However, a disparity between the energy saving of running on a -5% gradient (-17%) and the additional energy cost of running on a +5% gradient (+32%) was evident. The cross-sectional and longitudinal analysis of a large cohort of highly trained runners in chapter 6 revealed a small (r=0.25) and moderate (r=0.35) association between energy cost and maximal oxygen uptake, respectively. Finally, chapter 7 demonstrated that eight weeks of supplementary downhill run training at vLTP in existing training programmes does not enhance running economy in already well trained runners (1.22 vs 1.20 kcal kg-1 km-1; P=0.41), despite a significant increase (+2.4%) in the velocity at lactate turnpoint. In conclusion, this thesis demonstrates that energy cost, expressed as kcal kg-1 km-1, provides a reliable and valid method to quantify running economy in trained distance runners. However, further investigation is required to identify robust training methods to enhance running economy in this already highly trained population

    The First World War Centenary in the UK: ‘A Truly National Commemoration’?

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    Prime Minister David Cameron has called for ‘a truly national commemoration of the First World War’. This article shows this to be problematic, politicised and contested. This is in part due to the elision of English and British histories. Scottish, Welsh and Irish responses are noted, and the role and commemorations of ‘our friends in the Commonwealth’. There are tensions around interpretations of empire and race. There has been a failure to appreciate that the debates about the legacies of the First World War are deeply entangled with those of colonialism

    Accuracy and feasibility of an android-based digital assessment tool for post stroke visual disorders - The StrokeVision App

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    Background: Visual impairment affects up to 70% of stroke survivors. We designed an app (StrokeVision) to facilitate screening for common post stroke visual issues (acuity, visual fields and visual inattention). We sought to describe the test-time, feasibility, acceptability and accuracy of our app based digital visual assessments against a) current methods used for bedside screening, and b) gold standard measures. Methods: Patients were prospectively recruited from acute stroke settings. Index tests were app based assessments of fields and inattention performed by a trained researcher. We compared against usual clinical screening practice of visual fields to confrontation including inattention assessment (simultaneous stimuli). We also compared app to gold standard assessments of formal kinetic perimetry (Goldman or Octopus Visual Field Assessment); and pencil and paper based tests of inattention (Albert’s, Star Cancellation, and Line Bisection). Results of inattention and field tests were adjudicated by a specialist Neuro-Ophthalmologist. All assessors were masked to each other’s results. Participants and assessors graded acceptability using a bespoke scale that ranged from 0 (completely unacceptable) to 10 (perfect acceptability). Results: Of 48 stroke survivors recruited, the complete battery of index and reference tests for fields was successfully completed in 45. Similar acceptability scores were observed for app-based (assessor median score 10 [IQR:9-10]; patient 9 [IQR:8-10]) and traditional bedside testing (assessor 10 [IQR:9-10; patient 10 [IQR:9-10]). Median test time was longer for app-based testing (combined time-to-completion of all digital tests 420 seconds [IQR:390-588]) when compared with conventional bedside testing (70 seconds, [IQR:40-70]) but shorter than gold standard testing (1260 seconds, [IQR:1005-1620]). Compared with gold standard assessments, usual screening practice demonstrated 79% sensitivity and 82% specificity for detection of a stroke-related field defect. This compares with 79% sensitivity and 88% specificity for StrokeVision digital assessment. Conclusion: StrokeVision shows promise as a screening tool for visual complications in the acute phase of stroke. The app is at least as good as usual screening and offers other functionality that may make it attractive for use in acute stroke

    Saturated gain spectrum of VECSELs determined by transient measurement of lasing onset

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    We describe time-resolved measurements of the evolution of the spectrum of radiation emitted by an optically-pumped continuous-wave InGaAs-GaAs quantum well laser, recorded as lasing builds up from noise to steady state. We extract a fitting parameter corresponding to the gain dispersion of the parabolic spectrum equal to ?79 ± 30 fs2 and ?36 ± 6 fs2 for a resonant and anti-resonant structure, respectively. Furthermore the recorded evolution of the spectrum allows for the calculation of an effective FWHM gain bandwidth for each structure, of 11 nm and 18 nm, respectively

    Additively manufacturable micro-mechanical logic gates.

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    Early examples of computers were almost exclusively based on mechanical devices. Although electronic computers became dominant in the past 60 years, recent advancements in three-dimensional micro-additive manufacturing technology provide new fabrication techniques for complex microstructures which have rekindled research interest in mechanical computations. Here we propose a new digital mechanical computation approach based on additively-manufacturable micro-mechanical logic gates. The proposed mechanical logic gates (i.e., NOT, AND, OR, NAND, and NOR gates) utilize multi-stable micro-flexures that buckle to perform Boolean computations based purely on mechanical forces and displacements with no electronic components. A key benefit of the proposed approach is that such systems can be additively fabricated as embedded parts of microarchitected metamaterials that are capable of interacting mechanically with their surrounding environment while processing and storing digital data internally without requiring electric power

    Fundamental properties of the mammalian innate immune system revealed by multispecies comparison of type I interferon responses

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    The host innate immune response mediated by type I interferon (IFN) and the resulting up-regulation of hundreds of interferon-stimulated genes (ISGs) provide an immediate barrier to virus infection. Studies of the type I ‘interferome’ have mainly been carried out at a single species level, often lacking the power necessary to understand key evolutionary features of this pathway. Here, using a single experimental platform, we determined the properties of the interferomes of multiple vertebrate species and developed a webserver to mine the dataset. This approach revealed a conserved ‘core’ of 62 ISGs, including genes not previously associated with IFN, underscoring the ancestral functions associated with this antiviral host response. We show that gene expansion contributes to the evolution of the IFN system and that interferomes are shaped by lineage-specific pressures. Consequently, each mammal possesses a unique repertoire of ISGs, including genes common to all mammals and others unique to their specific species or phylogenetic lineages. An analysis of genes commonly down-regulated by IFN suggests that epigenetic regulation of transcription is a fundamental aspect of the IFN response. Our study provides a resource for the scientific community highlighting key paradigms of the type I IFN response

    Comparative analysis of the mammalian WNT4 promoter

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    BACKGROUND: WNT4 is a critical signalling molecule in embryogenesis and homeostasis, but the elements that control its transcriptional regulation are largely unknown. This study uses comparative cross species sequence and functional analyses between humans and a marsupial (the tammar wallaby,Macropus eugenii) to refine the mammalian Wnt4 promoter. RESULTS: We have defined a highly conserved 89 bp minimal promoter region in human WNT4 by comparative analysis with the tammar wallaby. There are many conserved transcription factor binding sites in the proximal promoter region, including SP1, MyoD, NFkappaB and AP2, as well as highly conserved CpG islands within the human, mouse and marsupial promoters, suggesting that DNA methylation may play an important role in WNT4 transcriptional regulation. CONCLUSION: Using a marsupial model, we have been able to provide new information on the transcriptional regulators in the promoter of this essential mammalian developmental gene, WNT4. These transcription factor binding sites and CpG islands are highly conserved in two disparate mammals, and are likely key controlling elements in the regulation of this essential developmental gene

    The efficacy of downhill running as a method to enhance running economy in trained distance runners

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    © 2018 European College of Sport Science Running downhill, in comparison to running on the flat, appears to involve an exaggerated stretch-shortening cycle (SSC) due to greater impact loads and higher vertical velocity on landing, whilst also incurring a lower metabolic cost. Therefore, downhill running could facilitate higher volumes of training at higher speeds whilst performing an exaggerated SSC, potentially inducing favourable adaptations in running mechanics and running economy (RE). This investigation assessed the efficacy of a supplementary 8-week programme of downhill running as a means of enhancing RE in well-trained distance runners. Nineteen athletes completed supplementary downhill (−5% gradient; n = 10) or flat (n = 9) run training twice a week for 8 weeks within their habitual training. Participants trained at a standardised intensity based on the velocity of lactate turnpoint (vLTP), with training volume increased incrementally between weeks. Changes in energy cost of running (E C ) and vLTP were assessed on both flat and downhill gradients, in addition to maximal oxygen uptake (⩒O 2max). No changes in E C were observed during flat running following downhill (1.22 ± 0.09 vs 1.20 ± 0.07 Kcal kg −1  km −1 , P = .41) or flat run training (1.21 ± 0.13 vs 1.19 ± 0.12 Kcal kg −1  km −1 ). Moreover, no changes in E C during downhill running were observed in either condition (P  >  .23). vLTP increased following both downhill (16.5 ± 0.7 vs 16.9 ± 0.6 km h −1 ,P = .05) and flat run training (16.9 ± 0.7 vs 17.2 ± 1.0 km h −1 , P = .05), though no differences in responses were observed between groups (P = .53). Therefore, a short programme of supplementary downhill run training does not appear to enhance RE in already well-trained individuals

    Releasing latent compassion through an innovative compassion curriculum for Specialist Community Public Health Nurses

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    Aims: To evaluate the impact of a curriculum based on the Compassionate Mind Model designed to facilitate the expression of compassion in Specialist Community Public Health Nurses. Background: The Compassionate Mind Model identifies that fear of compassion creates a barrier to the flow of compassion. There is some evidence linking self-compassion to compassionate care but no previous research has explored this potential with post registration specialist community public health nursing students. Design: Prospective, longitudinal design using focus group interviews. Methods: 26 students (81% of cohort) agreed to participate in a wider evaluation (2014-2015). For this study, two groups were drawn from those participants (total 13 students) who attended audio-taped group interviews at the course mid- and end-points to explore their perceptions on compassion and compassionate care. Transcripts were analysed thematically. Findings: A number of sub-themes were identified. ‘Cultural change in the NHS’, ‘Workload and meeting targets’ and ‘Lack of time were barriers to compassionate care, as was negative ‘Role modelling’. These were collated under a macro-theme of ‘A culture lacking in compassion’. Secondly, the sub-themes ‘Actualisation of compassion’ and ‘Transformation’ were collated within a macro-theme: ‘Realisation of compassion’. This theme identified realisation of latent compassion from their previous roles that in some transferred into students’ personal lives suggesting a transformation beyond professional attitude. Conclusion: The curriculum facilitated a realisation of compassion in students over the period of the course by enhancing their capacity to be self-compassionate and by actualisation of compassion that had previously been suppressed
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