3,138 research outputs found

    A comparison between single sided friction stir welded and submerged arc welded DH36 steel thin plate

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    The adoption of the friction stir welding (FSW) process into the shipbuilding industry is being considered as a medium term issue. Currently the data on friction stir welded mild steels tends to be fragmented, with critical areas being short on specific data e.g. toughness. The work described has been put in place to directly compare friction stir welded and submerged arc welded thin plate. The plate thicknesses used were 4, 6 and 8mm thick DH36 grade steel, which are commonly used in the construction of vessels such and destroyers, frigates corvettes and offshore patrol vessels. Friction stir welding was carried out using the currently best established parameters for a single sided process and this was compared against Submerged Arc Welding (SAW) over the same thickness range. Distortion was found to be lower in friction stir welded steel, but the 4mm thick was still showing significant distortion. No issues were identified with weld metal strength, and toughness at -20OC was found to be comparable but more uniform across the weld area than with the submerged arc welded material. Microstructural observations have been linked to hardness, toughness and fatigue test data. The fatigue data includes the observation of preferential crack initiation relative to the trailing/leading side of the welding process. An assessment on the feasibility of the process in a shipbuilding environment will be included based on the data presented

    Influence of Pacing Strategy on Oxygen Uptake During Treadmill Middle-Distance Running

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    The oxygen uptake (V·O2) attained during a constant speed 800-m pace trial on a treadmill is less than the maximal V·O2 (V·O2max) in male middle-distance runners with a high V·O2max (i.e., > 65 ml · kg-1 · min-1). We therefore investigated whether the V·O2 attained was influenced by the pacing strategy adopted. Eight male middle-distance runners (age 25.8 ± 3.3 years; height 1.78 ± 0.10 m; mass 67.8 ± 4.7 kg) with a personal best 800-m time of 112.0 ± 3.3 s volunteered to participate. Subjects undertook a speed ramped progressive test to determine V·O2max and three 800-m pace runs to exhaustion all in a randomised order. The three 800-m pace runs included constant speed, acceleration, and race simulation runs. Oxygen uptake was determined throughout each test using 15-s Douglas bag collections. Following the application of a 30-s rolling average, the highest V·O2 during the progressive test (i.e., V·O2max) and the highest V·O2 during the 800-m pace runs (i.e., V·O2peak) were compared. For the eight runners, V·O2max was 67.2 ± 4.3 ml · kg-1 · min-1. V·O2peak was 60.1 ± 5.1 ml · kg-1 · min-1, 61.1 ± 5.2 ml · kg-1 · min-1, and 62.2 ± 4.9 ml · kg-1 · min-1, yielding values of 89.3 ± 2.4 %, 90.8 ± 2.8 %, and 92.5 ± 3.1 % V·O2max for the constant speed, acceleration and race simulation runs, respectively. Across runs, repeated measures ANOVA revealed a significant effect (p = 0.048). Trend analysis identified a significant linear trend (p = 0.025) with the % V·O2max attained being higher for the acceleration run than the constant speed run, and higher still for the race simulation run. These results demonstrate that in middle-distance runners a) pacing strategy influences the V·O2 attained, with a race simulation run elevating the V·O2 attained compared with other pacing strategies, and b) regardless of pacing strategy the V·O2 attained in an 800-m pace run on a treadmill is less than V·O2max

    Influence of Pacing Strategy on Oxygen Uptake During Treadmill Middle-Distance Running

    Get PDF
    The oxygen uptake (V·O2) attained during a constant speed 800-m pace trial on a treadmill is less than the maximal V·O2 (V·O2max) in male middle-distance runners with a high V·O2max (i.e., > 65 ml · kg-1 · min-1). We therefore investigated whether the V·O2 attained was influenced by the pacing strategy adopted. Eight male middle-distance runners (age 25.8 ± 3.3 years; height 1.78 ± 0.10 m; mass 67.8 ± 4.7 kg) with a personal best 800-m time of 112.0 ± 3.3 s volunteered to participate. Subjects undertook a speed ramped progressive test to determine V·O2max and three 800-m pace runs to exhaustion all in a randomised order. The three 800-m pace runs included constant speed, acceleration, and race simulation runs. Oxygen uptake was determined throughout each test using 15-s Douglas bag collections. Following the application of a 30-s rolling average, the highest V·O2 during the progressive test (i.e., V·O2max) and the highest V·O2 during the 800-m pace runs (i.e., V·O2peak) were compared. For the eight runners, V·O2max was 67.2 ± 4.3 ml · kg-1 · min-1. V·O2peak was 60.1 ± 5.1 ml · kg-1 · min-1, 61.1 ± 5.2 ml · kg-1 · min-1, and 62.2 ± 4.9 ml · kg-1 · min-1, yielding values of 89.3 ± 2.4 %, 90.8 ± 2.8 %, and 92.5 ± 3.1 % V·O2max for the constant speed, acceleration and race simulation runs, respectively. Across runs, repeated measures ANOVA revealed a significant effect (p = 0.048). Trend analysis identified a significant linear trend (p = 0.025) with the % V·O2max attained being higher for the acceleration run than the constant speed run, and higher still for the race simulation run. These results demonstrate that in middle-distance runners a) pacing strategy influences the V·O2 attained, with a race simulation run elevating the V·O2 attained compared with other pacing strategies, and b) regardless of pacing strategy the V·O2 attained in an 800-m pace run on a treadmill is less than V·O2max

    Lateral entorhinal cortex lesions impair odor-context associative memory in male rats

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    This work was supported by the Biotechnology and Biological Sciences Research Council (BBSRC) [grant number BB/M010996/1].Lateral entorhinal cortex (LEC) has been hypothesized to process nonspatial, item information that is combined with spatial information from medial entorhinal cortex to form episodic memories within the hippocampus. Recent studies, however, have demonstrated that LEC has a role in integrating features of episodic memory prior to the hippocampus. While the precise role of LEC is still unclear, anatomical studies show that LEC is ideally placed to be a hub integrating multisensory information. The current study tests whether the role of LEC in integrating information extends to long-term multimodal item-context associations. In Experiment 1, male rats were trained on a context-dependent odor discrimination task, where two different contexts served as the cue to the correct odor. Rats were pretrained on the task and then received either bilateral excitotoxic LEC or sham lesions. Following surgery, rats were tested on the previously learned odor-context associations. Control rats showed good memory for the previously learned association but rats with LEC lesions showed significantly impaired performance relative to both their own presurgery performance and to control rats. Experiment 2 went on to test whether impairments in Experiment 1 were the result of LEC lesions impairing either odor or context memory retention alone. Male rats were trained on simple odor and context discrimination tasks that did not require integration of features to solve. Following surgery, both LEC and control rats showed good memory for previously learned odors and contexts. These data show that LEC is critical for long-term odor-context associative memory.Publisher PDFPeer reviewe

    VO2 Attained During Treadmill Running: The Influence of a Specialist (400-m or 800-m) Event

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    Purpose: Previously it has been observed that, in well-trained 800-m athletes, VO(2)max is not attained during middle-distance running events on a treadmill, even when a race-type pacing strategy is adopted. Therefore, the authors investigated whether specialization in a particular running distance (400-m or 800-m) influences the VO(2) attained during running on a treadmill. Methods: Six 400-m and six 800-m running specialists participated in the study. A 400-m trial and a progressive test to determine VO(2)max were completed in a counterbalanced order. Oxygen uptakes attained during the 400-m trial were compared to examine the influence of specialist event. Results: A VO(2) plateau was observed in all participants for the progressive test, demonstrating the attainment of VO(2)max. The VO(2)max values were 56.2 +/- 4.7 and 69.3 +/- 4.5 mL . kg(-1) min(-1) for the 400-m- and 800-m-event specialists, respectively (P = .0003). Durations for the 400-m trial were 55.1 +/- 4.2 s and 55.8 +/- 2.3 s for the 400-m- and 800-m-event specialists, respectively. The VO(2) responses achieved were 93.1% +/- 2.0% and 85.7% +/- 3.0% VO(2)max for the 400-m- and 800-m-event specialists, respectively (P = .001). Conclusions: These results demonstrate that specialist running events do appear to influence the percentage of VO(2)max achieved in the 400-m trial, with the 800-m specialists attaining a lower percentage of VO(2)max than the 400-m specialists. The 400-m specialists appear to compensate for a lower VO(2)max by attaining a higher percentage VO(2)max during a 400-m trial

    Influence of test duration on oxygen uptake attained during treadmill running

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    Previous investigations have revealed that in well-trained middle-distance runners, oxygen uptake (VO2) does not attain maximal values (VO2max) in exhaustive treadmill trials where the VO2 demand exceeds VO2max. To date, this shortfall in the VO2 attained has been demonstrated in trials as short as 2 min in duration. In this study, we investigated whether a reduction in exhaustive test duration influences the VO2 attained during running on a treadmill. Six middle-distance runners participated in the study, completing an exhaustive 400 m and 800 m trial. These trials, together with a progressive test to determine VO2max, were completed in a counterbalanced order. Oxygen uptakes attained during the 400 m and 800 m trials were compared to examine the influence of exhaustive test duration. A plateau in VO2 was observed in all participants for the progressive test, demonstrating the attainment of VO2max. The mean speed, duration, and resulting distance in the constant-speed exhaustive trials were 25.8 km h(-1) (s=1.2), 55.8 s (s=2.3), and 400.2 m (s=20.2) for the 400 m trial, and 24.3 km h(-1) (s=0.8), 108.4 s (s=21.2), and 730.1 m (s=129.1) for the 800 m trial, respectively. A paired-samples t-test revealed a significantly different (P=0.018)%VO2max was attained for the 400 m (85.7%, s=3.0) and 800 m (89.1%, s=5.0) trials. In conclusion, VO2 did not reach VO2max during the exhaustive constant-speed 400 m and 800 m trials, but the test duration does influence the%VO2max achieved. Specifically, the VO2 attained becomes progressively further below VO2max as trial duration is reduced, such that 89% and 86% VO2max is achieved in exhaustive 800 m and 400 m constant-speed trials, respectively

    Standardisation of delivery and assessment of research training for specialty trainees based on curriculum requirements : recommendations based on a scoping review

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    OBJECTIVES: (1) To conduct a scoping review of postgraduate specialty training (ST) curricula for doctors within Health Education England in order to identify common themes and variations in requirements for training and assessment of research competencies. (2) To make recommendations on standardisation of training for clinical research across ST programmes. SETTING: Health Education England North East and National Institute for Health Research Clinical Research Network (CRN)-North East and North Cumbria. METHODS: Annual Review of Competence Progression (ARCP); Certificate of Completion of Training (CCT) checklists and curricula for ST were obtained from Health Education England North East and reviewed between June and September 2015. Research competence requirements based on knowledge, skills or behaviour-based domains were identified and entered onto a spreadsheet for analysis. Common themes with levels of competence required were identified. This information was used to construct and propose a model for delivery of training in clinical research across ST programmes. RESULTS: Sixty-two ST curricula were reviewed and seven common themes for research training were found in up to 97% of the curricula. Requirement for good clinical practice (GCP) in research training was included in 15% of curricula. One of the common themes involved knowledge-based competency, and three each of the remaining seven involved skills or behaviour-based competencies. There was less clarity and larger variation between specialties in how research competencies were assessed; and what evidence was required for ARCP and CCT to assure competence. 63% (19/30) of curricula from medical specialties had no mention of research requirements within their ARCP guidelines. CONCLUSIONS: Given that the majority of specialty curricula contain consistent themes around core research knowledge, consideration should be given to standardising the delivery and assessment of generic research competencies within ST. Our recommendations from this review could form the basis for developing structured research training for specialty trainees involving: (1) a taught course for knowledge-based competencies; (2) clinical placements with CRN teams for practical workplace-based experience and (3) developing research tutors to help support placements and assessment of these competencies

    Antiretroviral Treatment Cohort Analysis Using Time-Updated CD4 Counts: Assessment of Bias with Different Analytic Methods

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    BACKGROUND: Survival analysis using time-updated CD4+ counts during antiretroviral therapy is frequently employed to determine risk of clinical events. The time-point when the CD4+ count is assumed to change potentially biases effect estimates but methods used to estimate this are infrequently reported. METHODS: This study examined the effect of three different estimation methods: assuming i) a constant CD4+ count from date of measurement until the date of next measurement, ii) a constant CD4+ count from the midpoint of the preceding interval until the midpoint of the subsequent interval and iii) a linear interpolation between consecutive CD4+ measurements to provide additional midpoint measurements. Person-time, tuberculosis rates and hazard ratios by CD4+ stratum were compared using all available CD4+ counts (measurement frequency 1-3 months) and 6 monthly measurements from a clinical cohort. Simulated data were used to compare the extent of bias introduced by these methods. RESULTS: The midpoint method gave the closest fit to person-time spent with low CD4+ counts and for hazard ratios for outcomes both in the clinical dataset and the simulated data. CONCLUSION: The midpoint method presents a simple option to reduce bias in time-updated CD4+ analysis, particularly at low CD4 cell counts and rapidly increasing counts after ART initiation

    The clinically led worforcE and activity redesign (CLEAR) programme: a novel data-driven healthcare improvement methodology

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    Background: The NHS is facing substantial pressures to recover from the COVID-19 pandemic. Optimising workforce modelling is a fundamental component of the recovery plan. The Clinically Lead workforcE and Activity Redesign (CLEAR) programme is a unique methodology that trains clinicians to redesign services, building intrinsic capacity and capability, optimising patient care and minimising the need for costly external consultancy. This paper describes the CLEAR methodology and the evaluation of previous CLEAR projects, including the return on investment. Methods: CLEAR is a work-based learning programme that combines qualitative techniques with data analytics to build innovations and new models of care. It has four unique stages: (1) Clinical engagement- used to gather rich insights from stakeholders and clinicians. (2) Data interrogation- utilising clinical and workforce data for cohort analysis. (3) Innovation- using structured innovation methods to develop new models of care. (4) Recommendations- report writing, impact assessment and presentation of key findings to executive boards. A mixed-methods formative evaluation was carried out on completed projects, which included semi-structured interviews and surveys with CLEAR associates and stakeholders, and a health economic logic model that was developed to link the inputs, processes, outputs and the outcome of CLEAR as well as the potential impacts of the changes identified from the projects. Results: CLEAR provides a more cost-effective delivery of complex change programmes than the alternatives – resulting in a cost saving of £1.90 for every £1 spent independent of implementation success. Results suggest that CLEAR recommendations are more likely to be implemented compared to other complex healthcare interventions because of the levels of clinical engagement and have a potential return on investment of up to £14 over 5 years for every £1 invested. CLEAR appears to have a positive impact on staff retention and wellbeing, the cost of a CLEAR project is covered if one medical consultant remains in post for a year. Conclusions: The unique CLEAR methodology is a clinically effective and cost-effective complex healthcare innovation that optimises workforce and activity design, as well as improving staff retention. Embedding CLEAR methodology in the NHS could have substantial impact on patient care, staff well-being and service provision

    Homeworking, Well-Being and the COVID-19 Pandemic: A Diary Study

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    From MDPI via Jisc Publications RouterHistory: accepted 2021-06-29, pub-electronic 2021-07-16Publication status: PublishedFunder: Economic and Social Research Council; Grant(s): xxxxxAs a response to the COVID-19 pandemic, many governments encouraged or mandated homeworking wherever possible. This study examines the impact of this public health initiative on homeworkers’ well-being. It explores if the general factors such as job autonomy, demands, social support and work–nonwork conflict, which under normal circumstances are crucial for employees’ well-being, are outweighed by factors specific to homeworking and the pandemic as predictors of well-being. Using data from four-week diary studies conducted at two time periods in 2020 involving university employees in the UK, we assessed five factors that may be associated with their well-being: job characteristics, the work–home interface, home location, the enforced nature of the homeworking, and the pandemic context. Multi-level analysis confirms the relationship between four of the five factors and variability in within-person well-being, the exception being variables connected to the enforced homeworking. The results are very similar in both waves. A smaller set of variables explained between-person variability: psychological detachment, loneliness and job insecurity in both periods. Well-being was lower in the second than the first wave, as loneliness increased and the ability to detach from work declined. The findings highlight downsides of homeworking, will be relevant for employees’ and employers’ decisions about working arrangements post-pandemic, and contribute to the debate about the limits of employee well-being models centred on job characteristics
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