30 research outputs found

    The effects of vertical vs. horizontal plyometric training on sprinting kinetics in post peak height female student athletes

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    Plyometric training is a form of jump training that is a useful method to improve sprinting speed due to its propensity to improve neural efficiency, increase joint stiffness and contraction speed. While research has shown that plyometrics can improve jumping and sprinting performance, no studies have compared the effects of different types of plyometric training on sprinting speed in young females. Therefore, the aim of the study was to compare different forms of plyometric training (horizontal and vertical) on sprinting performance in young females. Thirty young females from a private girls college were randomly divided into two groups and trained for seven weeks, twice a week; vertical plyometric (n=11, age 13.50 ± 0.96, peak heigh velocity-PHV: 1.60 ± 1.14), horizontal plyometric training (n=10, 13.40 ± 0.92, PHV:1.60 ± 0.93), and a physical education class as a control (n=15, age, 15.60 ± 0.31, PHV: 2.90 ± 0.55). Participants were tested for sprinting kinetics i.e. force (Fo), maximum power (Pmax), theoretical velocity (Vo), maximal velocity (Vmax), 10, 20 and 30 m split times using a radar gun over 30 m, isometric strength, vertical jump height and horizontal jump distance before and after the intervention. Both the intervention groups significantly improved all performance variables (g= 0.32- 1.30; p<0.05). The vertical group improved all kinetic variables except Fo and Pmax whereas the horizontal group improved all kinetic variables with a greater effect size g= 0.40-1.30. In comparison to the control group, the vertical group significantly improved Vo, Vmax, vertical and broad jump scores whereas the horizontal group significantly improved broad jump and 20 m split time scores (p<0.05). The findings of this study suggest that horizontal plyometric training is more effective in improving sprinting kinetics

    HEAD IMPACTS DURING SPARRING: DIFFERENCES AND SIMILARITIES BETWEEN MOUTHGUARD, SKIN, AND HEADGEAR SENSORS

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    The timely identification of concussions is essential to ensuring athlete safety. In contact sports, many devices are available to measure head impacts, but concerns remain regarding their ability to accurately estimate the number and magnitude of those impacts. This study measured head impacts during boxing sparring simultaneously with three sensors – a mouthguard, a skin patch and a headgear patch – and video analysis. The objective was to assess and compare the number, quality, and magnitude of impact events across sensor types. All sensors had issues related to decoupling from the skull, although the mouthguard appeared to generate better estimates than the patches of the number of impacts and impact-induced head kinematics

    Efficacy of a compulsory homework programme for increasing physical activity and improving nutrition in children: A cluster randomised controlled trial

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    Background: Most physical activity interventions in children focus on the school setting; however, children typically engage in more sedentary activities and spend more time eating when at home. The primary aim of this cluster randomised controlled trial was to investigate the effects of a compulsory, health-related homework programme on physical activity, dietary patterns, and body size in primary school-aged children. Methods: A total of 675 children aged 7-10 years from 16 New Zealand primary schools participated in the Healthy Homework study. Schools were randomised into intervention and control groups (1:1 allocation). Intervention schools implemented an 8-week applied homework and in-class teaching module designed to increase physical activity and improve dietary patterns. Physical activity was the primary outcome measure, and was assessed using two sealed pedometers that monitored school- and home-based activity separately. Secondary outcome measures included screen-based sedentary time and selected dietary patterns assessed via parental proxy questionnaire. In addition, height, weight, and waist circumference were measured to obtain body mass index (BMI) and waist-to-height ratio (WHtR). All measurements were taken at baseline (T0), immediately post-intervention (T1), and 6-months post-intervention (T2). Changes in outcome measures over time were estimated using generalised linear mixed models (GLMMs) that adjusted for fixed (group, age, sex, group x time) and random (subjects nested within schools) effects. Intervention effects were also quantified using GLMMs adjusted for baseline values. Results: Significant intervention effects were observed for weekday physical activity at home (T1 [P < 0.001] and T2 [P = 0.019]), weekend physical activity (T1 [P < 0.001] and T2 [P < 0.001]), BMI (T2 only [P = 0.020]) and fruit consumption (T1 only [P = 0.036]). Additional analyses revealed that the greatest improvements in physical activity occurred in children from the most socioeconomically deprived schools. No consistent effects on sedentary time, WHtR, or other dietary patterns were observed. Conclusions: A compulsory health-related homework programme resulted in substantial and consistent increases in children's physical activity - particularly outside of school and on weekends - with limited effects on body size and fruit consumption. Overall, our findings support the integration of compulsory home-focused strategies for improving health behaviours into primary education curricula. Trial registration: Australian New Zealand Clinical Trials Registry, ACTRN12618000590268. Registered 17 April 2018. © 2019 The Author(s)

    Cross-cultural validation of the stroke riskometer using generalizability theory.

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    The Stroke Riskometer mobile application is a novel, validated way to provide personalized stroke risk assessment for individuals and motivate them to reduce their risks. Although this app is being used worldwide, its reliability across different countries has not yet been rigorously investigated using appropriate methodology. The Generalizability Theory (G-Theory) is an advanced statistical method suitable for examining reliability and generalizability of assessment scores across different samples, cultural and other contexts and for evaluating sources of measurement errors. G-Theory was applied to the Stroke Riskometer data sampled from 1300 participants in 13 countries using two-facet nested observational design (person by item nested in the country). The Stroke Riskometer demonstrated strong reliability in measuring stroke risks across the countries with coefficients G relative and absolute of 0.84, 95%CI [0.79; 0.89] and 0.82, 95%CI [0.76; 0.88] respectively. D-study analyses revealed that the Stroke Riskometer has optimal reliability in its current form in measuring stroke risk for each country and no modifications are required. These results suggest that the Stroke Riskometer's scores are generalizable across sample population and countries permitting cross-cultural comparisons. Further studies investigating reliability of the Stroke Riskometer over time in longitudinal study design are warranted

    High-Intensity Interval Training Is Equivalent to Moderate-Intensity Continuous Training for Short- and Medium-Term Outcomes of Glucose Control, Cardiometabolic Risk, and Microvascular Complication Markers in Men With Type 2 Diabetes

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    We sought to determine the efficacy of 12 weeks high-intensity interval training (HIIT), compared to moderate-intensity continuous training (MICT) on glucose control, cardiometabolic risk and microvascular complication markers in men living with type 2 diabetes (T2D). Both modalities were combined with resistance training (RT). Additionally, the study aimed to determine the medium-term durability of effects. After a 12-week, thrice weekly, training intervention incorporating either MICT+RT (n = 11) or HIIT+RT (n = 12), the study concluded with a 6-month follow-up analysis. The middle-aged study participants were obese, had moderate duration T2D and were taking multiple medications including insulin, statins and beta-blockers. Participants, randomized via the method of minimization, performed MICT (progressing to 26-min at 55% maximum estimated workload [eWLmax]) or HIIT (progressing to two variations in which twelve 1-min bouts at 95% eWLmax interspersed with 1-min recovery bouts, alternated with eight 30-s bouts at 120% eWLmax interspersed with 2:15 min recovery bouts) under supervision at an exercise physiology facility. To account for fixed and random effects within the study sample, mixed-effect models were used to determine the significance of change following the intervention and follow-up phases and to evaluate group*time interactions. Beyond improvements in aerobic capacity (P < 0.001) for both groups, both training modalities elicited similar group*time interactions (P > 0.05) while experiencing benefits for glycated hemoglobin (HbA1c; P = 0.01), subcutaneous adiposity (P < 0.001), and heart rate variability (P = 0.02) during the 12-week intervention. Adiposity (P < 0.001) and aerobic capacity (P < 0.001) were significantly maintained in both groups at the 6-month follow-up. In addition, during the intervention, participants in both MICT+RT and HIIT+RT experienced favorable reductions in their medication usage. The study reported the inter-individual variability of change within both groups, the exaggerated acute physiological responses (using exercise termination indicators) that occurred during the interventions as well as the incidence of precautionary respite afforded in such a study sample. To reduce hyperglycaemia, and prevent further deterioration of cardiometabolic risk and microvascular complication markers (in both the short- and medium-term), future strategies that integrate the adoption and maintenance of physical activity as a cornerstone in the treatment of T2M for men should (cognisant of appropriate supervision) include either structured MICT+RT, or HIIT+RT.Clinical Trials Registration Number: ACTRN12617000582358 http://www.anzctr.org.au/default.asp

    Parent and teacher-reported child outcomes seven years after mild traumatic brain Injury: A nested case control study

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    Background: Increasing evidence suggests potential lifetime effects following mild traumatic brain injury (TBI) in childhood. Few studies have examined medium-term outcomes among hospitalized and non-hospitalized samples. Study aims were to describe children's behavioral and emotional adjustment, executive function (EF), quality of life, and participation at 7-years following mild TBI using parents' and teachers' reports. Methods: Nested case control study of 86 children (68% male, mean age at assessment = 11.27 years; range 7–17 years) who sustained a mild TBI 7-years previously, identified from a prospective, population-based study. They were compared to 69 children free from TBI (61% male, mean age at assessment = 11.12 years; range 5–17 years). In addition to parent-reported socio-demographic details, parents (mild TBI n = 86, non-TBI n = 69) completed age-appropriate standardized questionnaires about children's health-related quality of life, behavioral and emotional adjustment, EF, and social participation. Parents own mood was assessed using the Hospital Anxiety and Depression Scale. Teachers (mild TBI n = 53, non-TBI n = 42) completed questionnaires about children's behavioral and emotional adjustment, and EF. Results: Parent reports showed median group-level scores for cases were statistically significantly greater than controls for emotional symptoms, conduct problems, hyperactivity/inattention, total behavioral difficulties, inhibitory control, shifting, planning/organizing, and Global Executive Composite (total) EF difficulties (p-values 0.001–0.029). Parent reports of child quality of life and social participation were similar, as were teacher reports of child behavioral and emotional adjustment, and EF (p > 0.05). When examining clinical cut-offs, compared to controls, cases had a higher risk of parent-reported total EF difficulties (odds ratio = 3.00) and, to a lesser extent, total behavior problems (odds ratio = 2.51). Conclusions: As a group, children with a history of mild TBI may be at elevated risk for clinically significant everyday EF difficulties in the medium-term compared to non-TBI controls, as judged by their parents. Further multi-informant longitudinal research is required, following larger samples. Aspects requiring particular attention include pre-injury characteristics, such as sleep disturbances and comorbidities (e.g., headaches), that may act as potential confounders influencing the association between mild TBI and child behavioral problems

    ON THE USE AND FUTURE OF ALTERNATIVE TESTING STRATEGIES IN REGULATORY TOXICOLOGY

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    Regulatory toxicology has emerged as a necessary discipline to ensure that chemicals introduced into commerce are safe. Contemporary history has taught us the hard way that while many chemicals are not harmful to human health, there too are many chemicals that were found after introduction into commerce to cause harm. This is a serious public health concern. Regulatory toxicologists inform decisions in part based on alternative test methods in addition to traditional in vivo studies. This is in part due to legal constraints placed on regulators, and it has not been articulated in research what these constraints and data are, or how these considerations inform regulatory decisions. The findings of this body of research reveal that alternative test methods primarily inform decisions of the US Environmental Protection Agency’s New Chemicals Program, which administers the Toxic Substances Control Act. This research also finds that there exist data gaps that need to be filled so that the New Chemicals Program can be able to make more informed decisions. Various studies have blossomed in recent years on the potential of alternative test methods to inform decisions, which includes the work of the ToxCast program. ToxCast has been productive in research, but has yet to have a method validated and implemented by regulators. This study finds that there are ToxCast parameters that may be predictive of hepatocarcinogenesis, but further research is warranted. Finally, the US National Academies of Sciences has promoted the use of alternative test methods, specifically putting forward the notion that the perturbation of network motifs may be a means to fill information gaps. The literature on motifs to date is limited to basic research, but recurring motifs across species that were identified in this body of research can be applicable within toxicity testing moving forward

    The future of ambulatory health care : a risk-informed model

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    Health care provided in ambulatory settings, is complex, with intricate processes, involving the deliberate coordination of many people, often across multiple organizational boundaries. With the ever expanding scope of ambulatory care, it is increasingly important to remove or mediate potential risks and harms to patients before they occur. While the use of adverse event reports and chart review identifies risks and harms retrospectively, it is important to also look forward and eliminate or reduce potential risks to patients before they occur. The framework laid out in this paper, which is grounded in risk analysis, is an emerging model to improve patient safety and reduce the probability that harmful events will occur. Each aspect of the model is critically important. Risk analyses identify aspects of the care process with greater potential likelihood and significance of harm. Diverse teams of professionals come together to evaluate and troubleshoot potential and actual hazards. Critically important is consistent, leadership backing. Boundary maintenance provides a means for ambulatory centers to maintain their identity and work effectively with other organizations. Finally, quality improvement interventions need to be engineered into ambulatory care where possible, so that quality of care and prevention of patient harm are normal parts of the work day. The U.S. Agency for Healthcare Research and Quality's (AHRQ's) Risk-Informed Intervention program is an important step forward in demonstrating the value of this model. Geographically distributed throughout the United States, these AHRQ teams conduct risk assessments and are now implementing important and potentially self-sustaining interventions that cross multiple organizational boundaries.7 page(s

    Network motifs that recur across species, including gene regulatory and protein-protein interaction networks

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    Cellular molecules interact in complex ways, giving rise to a cell's functional outcomes. Conscientious efforts have been made in recent years to better characterize these patterns of interactions. It has been learned that many of these interactions can be represented abstractly as a network and within a network there in many instances are network motifs. Network motifs are subgraphs that are statistically overrepresented within networks. To date, specific network motifs have been experimentally identified across various species and also within specific, intracellular networks; however, motifs that recur across species and major network types have not been systematically characterized. We reason that recurring network motifs could potentially have important implications and applications for toxicology and, in particular, toxicity testing. Therefore, the goal of this study was to determine the set of intracellular, network motifs found to recur across species of both gene regulatory and protein–protein interaction networks. We report the recurrence of 13 intracellular, network motifs across species. Ten recurring motifs were found across both protein–protein interaction networks and gene regulatory networks. The significant pair motif was found to recur only in gene regulatory networks. The diamond and one-way cycle reversible step motifs were found to recur only in protein–protein interaction networks. This study is the first formal review of recurring, intracellular network motifs across species. Within toxicology, combining our understanding of recurring motifs with mechanism and mode of action knowledge could result in more robust and efficient toxicity testing models. We are sure that our results will support research in applying network motifs to toxicity testing.11 page(s

    EPAs methodology to inform TSCA pre-manufacturing notification decision-making : a critical analysis based on chemicals regulated by consent order

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    Regulatory toxicology has emerged as a necessary discipline to ensure chemicals introduced into commerce are safe. The New Chemicals program is a regulatory toxicology program required under the Toxic Substances Control Act (TSCA) where the US Environmental Protection Agency (EPA) evaluates new or significant new uses of existing chemicals. Submitters are not required to include human or environmental effects data, or undertake toxicity testing and so constrain the EPA and the basic data available to make informed decisions. We therefore sought to determine the methodology used by this program to inform regulatory, consent order decisions. We found that the EPA applied analogue analyses, or in silico methods to inform two-thirds of the decisions evaluated. No new tests were carried out. This study’s findings are important for other regulators in the potential adoption of alternative testing methods to inform regulatory decisions going forward.14 page(s
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