127 research outputs found

    Monitoring neuromuscular fatigue in high performance athletes

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    With improving professionalism of sports around the world, the volume and frequency of training required for competitive performances at the elite level has increased concurrently. With this amplification in training load comes an increased need to closely monitor the associated fatigue responses, since maximising the adaptive response to training is also reliant on avoiding the negative consequences of excessive fatigue. The rationale for the experimental chapters in this thesis was established after considering survey responses regarding current best practice for monitoring fatigue in high performance sporting environments (Chapter 3). On the basis of the results, vertical jump assessments were selected for further investigation regarding their utility in determining neuromuscular fatigue responses. Outcomes from the subsequent series of studies aimed to provide practitioners working in high performance sport with guidelines for using vertical jumps to monitor athletic fatigue. The results from Chapter 4 indicate using the mean value of at least six jumps enhances the ability to detect small but practically important changes in performance from week to week. This study also highlighted large differences (4-6%) in morning and afternoon performance, indicating that the time of day performance is assessed needs to be accounted for when monitoring changes in jump performance. Chapter 5 explored the theory that the time of day effect observed in Chapter 4 can be explained by internal temperature differences. This theory was supported by demonstrating that an extended warm-up period can negate differences in jump performance in the morning and the afternoon. Researchers who are unable to standardise the time of day that assessment occurs are able, therefore, to control for performance differences by manipulating the warm-up protocols. The third study examined changes in vertical jump performance over a three month training period and produced several novel outcomes. A major finding was that unloaded jumps were more sensitive to neuromuscular fatigue during intensive training than loaded jumps (Chapter 6). Furthermore, this set of results showed that all subjects changed their jump technique via a reduction in the amplitude of the countermovement when they were highly fatigued. Using the same data, an analysis was performed to quantify individual differences in within-subject variation (Chapter 7) during normal and intensive training. These results provided the first indication that within-subject variability in vertical jump performance is substantially different between individuals and between different training phases, an important consideration for interpreting the practical importance of performance changes. In Chapter 8 the relationship between vertical jump performance and electrically elicited force of the knee extensors was examined to better understand the mechanism(s) of changes in jump performance associated with neuromuscular fatigue during intensive overload training. The results showed that the fatigue assessed by vertical jump performance was likely not only peripheral in origin as previously suggested by other authors. Further research is required to further understand the mechanisms of reduced performance during overload training, although the preliminary evidence presented implicates central mechanisms. To conclude the thesis, the findings presented in the experimental chapters are summarised, with a series of practical recommendations for using vertical jumps to monitor athletic fatigue presented

    Economic Impacts of Removing Federal Grazing Used by Cattle Ranches in Idaho, Oregon, and Wyoming

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    Lands managed by the Bureau of Land Management (BLM) and the U.S. Forest Service (USFS) are an important source of livestock grazing for many ranching operations in the Western United States. There are currently more than 22,000 authorized federal grazing permits representing 15.7 million animal unit months (AUMs) of grazing. Idaho, Oregon and Wyoming are examples of western states where many ranches are dependent on federal grazing. The combined total for the three states is 5,389 federal grazing permits, representing 5.6 million AUMs of grazing. In recent years, the use of federal lands for livestock grazing has become increasingly controversial with some organizations calling for the complete removal of all livestock grazing from public lands. The purpose of this analysis is to estimate the economic impact of removal of federal grazing by cattle on the combined Idaho, Oregon and Wyoming economy. The net effect of removal of federal cattle grazing in the three-state area is estimated to be a loss of 186.2millionindirecteconomicimpact,andareductionof186.2 million in direct economic impact, and a reduction of 560.5 million in total economic impact. These impacts equate to a loss of more than 4,000 jobs and decreased labor income of $205.4 million annually. Due to the cumulative nature of the impact, these negative effects are expected to continue for many years into the future if federal grazing is removed. The analysis indicates that removing federal cattle grazing would have significant negative economic impact on the three-state area, particularly on many rural counties that have sensitive economies due to their dependency on agricultural production and limited alternative employment opportunities

    Sources of Variability in Iso-inertial Jump Assessments

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    Purpose: This investigation aimed to quantify the typical variation for kinetic and kinematic variables measured during loaded jump squats. Methods: Thirteen professional athletes performed six maximal effort countermovement jumps on fouroccasions. Testing occurred over 2 d, twice per day (8 AM and 2 PM) separated by 7 d, with the same procedures replicated on each occasion. Jump height, peak power (PP), relative peak power (RPP), mean power (MP), peak velocity (PV), peak force (PF), mean force (MF), and peak rate of force development (RFD) measurements were obtained from a linear optical encoder attached to a 40 kg barbell. Results: A diurnal variation in performance was observed with afternoon values displaying an average increase of 1.5-5.6% for PP, RPP, MP, PV, PF, and MF when compared with morning values (effect sizes ranging from 0.2-0.5). Day to day reliability was estimated by comparing the morning trials (AM reliability) and the afternoon trials (PM reliability). In both AM and PM conditions, all variables except RFD demonstrated coefficients of variations ranging between 0.8-6.2%. However, for a number of variables (RPP, MP, PV and height), AM reliability was substantially better than PM. PF and MF were the only variables to exhibit a coefficient of variation less than the smallest worthwhile change in both conditions. Discussion: Results suggest that power output and associated variables exhibit a diurnal rhythm, with improved performance in the afternoon. Morning testing may be preferable when practitioners are seeking to conduct regular monitoring of an athlete\u27s performance due to smaller variabilit

    Measurement and Design in Surveys of Teachers’ Mental Health Literacy: A Scoping Review

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    Mental health literacy (MHL) was introduced four decades ago as a term referring to knowledge and beliefs about mental disorders that aid in their recognition, management, or prevention. This scoping review mapped the peer-reviewed literature to understand how MHL is defined, conceptualized, and measured in studies involving those becoming teachers (pre-service teachers) and working teachers (in-service teachers). The search was performed following the method for scoping reviews by the Joanna Briggs Institute (JBI). Searches were conducted in four scientific databases with no time limit, although all sources had to be written in English or French. Primary studies (N = 35) that measured MHL for pre- and in-service teachers provided a global snapshot of MHL conceptualization and measurement across five continents. Global conceptualizations of MHL were largely driven by the definition and measures developed by Jorm, though the definition by Kutcher et al. was used in one fourth of the papers. Few studies explicitly stated a theoretical framework. Most studies used closed-ended scales, or a combination of closed-ended scales and vignettes to measure MHL. From a closer examination of the results, Canada emerged as a major leader in teacher MHL. Future research in this area should aim to include vignette measures, especially for pre-service teachers, and explicit theoretical frameworks, including socio-ecological and social or structural determinants of health-related frameworks that take an intersectional approach to MHL

    Measurement and Design in Surveys of Teachers’ Mental Health Literacy: A Scoping Review

    Get PDF
    Mental health literacy (MHL) was introduced four decades ago as a term referring to knowledge and beliefs about mental disorders that aid in their recognition, management, or prevention. This scoping review mapped the peer-reviewed literature to understand how MHL is defined, conceptualized, and measured in studies involving those becoming teachers (pre-service teachers) and working teachers (in-service teachers). The search was performed following the method for scoping reviews by the Joanna Briggs Institute (JBI). Searches were conducted in four scientific databases with no time limit, although all sources had to be written in English or French. Primary studies (N = 35) that measured MHL for pre- and in-service teachers provided a global snapshot of MHL conceptualization and measurement across five continents. Global conceptualizations of MHL were largely driven by the definition and measures developed by Jorm, though the definition by Kutcher et al. was used in one fourth of the papers. Few studies explicitly stated a theoretical framework. Most studies used closed-ended scales, or a combination of closed-ended scales and vignettes to measure MHL. From a closer examination of the results, Canada emerged as a major leader in teacher MHL. Future research in this area should aim to include vignette measures, especially for pre-service teachers, and explicit theoretical frameworks, including socio-ecological and social or structural determinants of health-related frameworks that take an intersectional approach to MHL

    SPARK Linking Ready Kids to Ready Schools: A Report on Policy Insights from the Governors' Forum Series

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    Each year too many children start kindergarten unprepared to learn. Many will never catch up. The reasons for this are complex, but this much is clear: The multiple systems – from family to schools to government – that should be supporting young children too often are failing to do so. The W.K. Kellogg Foundation seeks to change that, and to permanently improve systems that affect children's learning.As policymakers look for ways to improve student outcomes by creating "seamless" systems of education starting at preschool, communities have been getting it done. SPARK (Supporting Partnerships to Assure Ready Kids) — a fiveyear initiative funded by the Kellogg Foundation — has contributed a unique, community-based perspective to the national conversation on what it takes to effectively link learning systems. In particular, SPARK examines what it takes at the beginning of the education pipeline to link early learning to the early grades. The goal is to make sure that children are ready for school and that schools are ready for them — a formula critical for a lifetime of successful learning.SPARK efforts are deeply anchored in the community and are designed to assure that children are successful both before and after they enter school. The strategy of working with schools, early care and education providers, families and community partners has yielded a set of proven ways to align local systems of education — approaches that have been tested in diverse rural and urban communities in Florida, Georgia, Hawaii, Mississippi, New Mexico, North Carolina, Ohio and Washington, D.C. What SPARK community-based sites have done to create connections across local systems of learning stands to influence larger school reform issues and state policy discussions about what is needed to create a more holistic learning experience for children — one that results in academic success at grade three and beyond

    Roles of the Nuclear Lamina in Stable Nuclear Association and Assembly of a Herpesviral Transactivator Complex on Viral Immediate-Early Genes

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    Little is known about the mechanisms of gene targeting within the nucleus and its effect on gene expression, but most studies have concluded that genes located near the nuclear periphery are silenced by heterochromatin. In contrast, we found that early herpes simplex virus (HSV) genome complexes localize near the nuclear lamina and that this localization is associated with reduced heterochromatin on the viral genome and increased viral immediate-early (IE) gene transcription. In this study, we examined the mechanism of this effect and found that input virion transactivator protein, virion protein 16 (VP16), targets sites adjacent to the nuclear lamina and is required for targeting of the HSV genome to the nuclear lamina, exclusion of heterochromatin from viral replication compartments, and reduction of heterochromatin on the viral genome. Because cells infected with the VP16 mutant virus in1814 showed a phenotype similar to that of lamin A/C−/− cells infected with wild-type virus, we hypothesized that the nuclear lamina is required for VP16 activator complex formation. In lamin A/C−/− mouse embryo fibroblasts, VP16 and Oct-1 showed reduced association with the viral IE gene promoters, the levels of VP16 and HCF-1 stably associated with the nucleus were lower than in wild-type cells, and the association of VP16 with HCF-1 was also greatly reduced. These results show that the nuclear lamina is required for stable nuclear localization and formation of the VP16 activator complex and provide evidence for the nuclear lamina being the site of assembly of the VP16 activator complex

    A novel intervention combining supplementary food and infection control measures to improve birth outcomes in undernourished pregnant women in Sierra Leone: A randomized, controlled clinical effectiveness trial

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    BACKGROUND: Innovations for undernourished pregnant women that improve newborn survival and anthropometry are needed to achieve the Sustainable Development Goals 1 and 3. This study tested the hypothesis that a combination of a nutritious supplementary food and several proven chemotherapeutic interventions to control common infections would increase newborn weight and length in undernourished pregnant women. METHODS AND FINDINGS: This was a prospective, randomized, controlled clinical effectiveness trial of a ready-to-use supplementary food (RUSF) plus anti-infective therapies compared to standard therapy in undernourished pregnant women in rural Sierra Leone. Women with a mid-upper arm circumference (MUAC) ≤23.0 cm presenting for antenatal care at one of 43 government health clinics in Western Rural Area and Pujehun districts were eligible for participation. Standard of care included a blended corn/soy flour and intermittent preventive treatment for malaria in pregnancy (IPTp). The intervention replaced the blended flour with RUSF and added azithromycin and testing and treatment for vaginal dysbiosis. Since the study involved different foods and testing procedures for the intervention and control groups, no one except the authors conducting the data analyses were blinded. The primary outcome was birth length. Secondary outcomes included maternal weight gain, birth weight, and neonatal survival. Follow-up continued until 6 months postpartum. Modified intention to treat analyses was undertaken. Participants were enrolled and followed up from February 2017 until February 2020. Of the 1,489 women enrolled, 752 were allocated to the intervention and 737 to the standard of care. The median age of these women was 19.5 years, of which 42% were primigravid. Twenty-nine women receiving the intervention and 42 women receiving the standard of care were lost to follow-up before pregnancy outcomes were obtained. There were 687 singleton live births in the intervention group and 657 in the standard of care group. Newborns receiving the intervention were 0.3 cm longer (95% confidence interval (CI) 0.09 to 0.6; p = 0.007) and weighed 70 g more (95% CI 20 to 120; p = 0.005) than those receiving the standard of care. Those women receiving the intervention had greater weekly weight gain (mean difference 40 g; 95% CI 9.70 to 71.0, p = 0.010) than those receiving the standard of care. There were fewer neonatal deaths in the intervention (n = 13; 1.9%) than in the standard of care (n = 28; 4.3%) group (difference 2.4%; 95% CI 0.3 to 4.4), (HR 0.62 95% CI 0.41 to 0.94, p = 0.026). No differences in adverse events or symptoms between the groups was found, and no serious adverse events occurred. Key limitations of the study are lack of gestational age estimates and unblinded administration of the intervention. CONCLUSIONS: In this study, we observed that the addition of RUSF, azithromycin, more frequent IPTp, and testing/treatment for vaginal dysbiosis in undernourished pregnant women resulted in modest improvements in anthropometric status of mother and child at birth, and a reduction in neonatal death. Implementation of this combined intervention in rural, equatorial Africa may well be an important, practical measure to reduce infant mortality in this context. TRIAL REGISTRATION: ClinicalTrials.gov NCT03079388

    Patient perspectives on the Tailored intervention for Anxiety and Depression Management in COPD (TANDEM):a qualitative evaluation

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    Background: Chronic obstructive pulmonary disease (COPD) is commonly associated with anxiety/depression which can affect self-management and quality of life. The TANDEM trial evaluated a cognitive behavioural approach intervention targeting COPD-related symptoms of anxiety and/or depression, comprising up to eight one-to-one sessions delivered by respiratory healthcare professionals prior to pulmonary rehabilitation (PR). The intervention showed no improvement in anxiety/depression or uptake/completion of PR. We present patient perspectives of the intervention to help understand these results. Method: Semi-structured individual interviews, using a semi-structured topic guide informed by Sekhon’s Theoretical Framework of Acceptability, were conducted with 19 patients between September 2019 and April 2020. The interviews were audio-recorded, transcribed verbatim and analysed thematically. Results: The following could have limited the impact of the intervention: (1) The lives of patients were complex and commonly affected by competing comorbidities or other external stressors which they managed through previously adopted long-standing coping strategies. (2) Some patients were reluctant to talk about their mood despite the Facilitators' training and person centred-skills which aimed to enable patients to talk freely about mood. (3) The intervention handouts and ‘home-practice’ were perceived as helpful for some, but not suitable for all. (4) Many patients perceived improvements in their physical and mental health, but this was not sustained due to a mix of personal and external factors, and some did not perceive any benefits. (5) PR non-attendance/non-completion was a result of personal and PR service-related reasons. (6) Discussing COPD and mental health with the Facilitator was a novel experience. Many patients felt that TANDEM could be of benefit if it was offered earlier on/at different time points in the COPD illness journey. Conclusion: We found the delivery of TANDEM prior to PR was not helpful for patients with advanced COPD often experiencing other comorbidities, and/or difficult personal/external events. These patients already utilised long-standing coping strategies to manage their COPD. Holistic interventions, that address the impact of COPD in relation to wider aspects of a patients’ life, may be more beneficial. Trial registration: ISRCTN Registry 59,537,391. Registration date 20 March 2017

    Warm protons at comet 67P/Churyumov–Gerasimenko – implications for the infant bow shock

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    The plasma around comet 67P/Churyumov–Gerasimenko showed remarkable variability throughout the entire Rosetta mission. Plasma boundaries such as the diamagnetic cavity, solar wind ion cavity and infant bow shock separate regions with distinct plasma parameters from each other. Here, we focus on a particular feature in the plasma: warm, slow solar wind protons. We investigate this particular proton population further by focusing on the proton behaviour and surveying all of the Rosetta comet phase data. We find over 300 events where Rosetta transited from a region with fast, cold protons into a region with warm, slow protons. We investigate the properties of the plasma and magnetic field at this boundary and the location where it can be found. We find that the protons are preferentially detected at intermediate gas production rates with a slight trend towards larger cometocentric distances for higher gas production rates. The events can mostly be found in the positive convective electric field hemisphere. These results agree well with simulations of the infant bow shock (IBS), an asymmetric structure in the plasma environment previously detected on only 2 d during the comet phase. The properties of the plasma on both sides of this structure are harder to constrain, but there is a trend towards higher electron flux, lower magnetic field, higher magnetic field power spectral density and higher density in the region that contains the warm protons. This is in partial agreement with the previous IBS definitions; however, it also indicates that the plasma and this structure are highly non-stationary. For future research, Comet Interceptor, with its multi-point measurements, can help to disentangle the spatial and temporal effects and give more clarity on the influence of changing upstream conditions on the movement of boundaries in this unusual environment
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