148 research outputs found

    The Potential of Community-Oriented Policing: A Report to the MidNorth Public Safety Committee

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    This report assesses the academic literature on community-oriented policing (COP) in regard to three shared goals of the Indianapolis Metropolitan Police Department (IMPD) and the MidNorth Public Safety Committee (MPSC): decreasing crime rates, limiting fear of crime, and increasing community empowerment. The report recommends specific strategies that can be integrated into IMPD’s community policing efforts. It also identifies the appropriate role for MPSC to play

    The Influence of Maturity Status on Dynamic Balance Following 6 Weeks of Eccentric Hamstring Training in Youth Male Handball Players

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    Information about when to apply an appropriate eccentric hamstring strength training stimulus during long-term athlete development is essential for effective programming and improving balance performance. This study examined the effects of six-week eccentric hamstring training on dynamic balance performance in youth handball players of different maturity statuses (pre- or post-peak height velocity (PHV)). A randomized controlled design with 45 young male handball players (14.6 ± 0.3 years) from a local national handball club were randomly allocated to a 6 week, twice weekly eccentric hamstring training in two experimental groups: a pre-PHV (maturation offset: −2.13 ± 0.63, n = 10) and post-PHV (maturation offset: 0.79 ± 0.34, n = 12) group and two control groups: maturation offset: −2.09 ± 0.61, n = 10 and maturation offset: 0.55 ± 0.67, n = 13. Dynamic balance performance was evaluated by using the composite score during the lower quarter Y-balance test from pre- and post-intervention. A significant effect on balance scores was found from pre to post (F = 11.4; p = 0.002; η(2)(p) = 0.22), intervention (F = 5.4; p = 0.025; η(2)(p) = 0.12), and maturation (F = 369; p < 0.001; η(2)(p) = 0.9), but no significant interaction effects were found (F ≥ 3.3; p ≥ 0.077; η(2)(p) ≤ 0.07). Post hoc analysis revealed that the post-PHV group had a higher score than the pre-PHV group. Furthermore, that dynamic balance increased in the post-PHV group after intervention much more in the control post-PHV group. It was concluded that somatic maturation influences dynamic balance performance and that eccentric hamstring training results in greater improvement in balance performance in young male handball players for the post-pubertal group

    Aging and Recovery After Resistance-Exercise-Induced Muscle Damage: Current Evidence and Implications for Future Research

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    Accepted author manuscript version reprinted, by permission, from Journal of Aging and Physical Activity, 2021, 29(3): 544-551, https://doi.org/10.1123/japa.2020-0201. © Human Kinetics, Inc.Aging is anecdotally associated with a prolonged recovery from resistance training, though current literature remains equivocal. This brief review considers the effects of resistance training on indirect markers of muscle damage and recovery (i.e., muscle soreness, blood markers, and muscle strength) in older males. With no date restrictions, four databases were searched for articles relating to aging, muscle damage, and recovery. Data from 11 studies were extracted for review. Of these, four reported worse symptoms in older compared with younger populations, while two have observed the opposite, and the remaining studies (n = 6) proposed no differences between age groups. It appears that resistance training can be practiced in older populations without concern for impaired recovery. To improve current knowledge, researchers are urged to utilize more ecologically valid muscle-damaging bouts and investigate the mechanisms which underpin the recovery of muscle soreness and strength after exercise in older populations

    The effects of a sled push at different loads on 20 metre sprint time in well-trained soccer players

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    This study determined the effects of a single sled push at different loads on sprint performance in competitive male soccer players. Twenty male competitive outfield soccer players (age 19.6±1.3y, body mass 73.6±8.2kg) were split into experimental (n=10) and control groups. In the experimental group, 20m linear sprint time was measured immediately before and 5, 6 and 7minutes after the sled push with either 50 or 100% body mass. The control group performed the 20m sprints only. A repeated measures ANOVA comparing control and experimental groups revealed no effects of time, group or time by group interaction for either experimental condition (all P&gt;0.05). The repeated measures ANOVA compared the experimental conditions revealed effects of time (P=0.034) and group (P=0.002), but not time by group (P&gt;0.05). The effects sizes demonstrated within group effects on sprint time that were small to moderate (-0.26 to 0.71) and trivial to small (-0.31 to 0.09) for the 50% and 100% body mass condition, respectively. These findings demonstrate that a sled push has no significant effect on 20 m sprint time in competitive footballers. If coaches continue to prescribed a sled push before sprinting, a single 15 m push with 50% body mass could have positive benefits

    Effects of small-sided games vs. conventional endurance training on endurance performance in male youth soccer players: A meta-analytical comparison

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    Background: Small-sided games have been suggested as a viable alternative to conventional endurance training to enhance endurance performance in youth soccer players. This has important implications for long-term athlete development because it suggests that players can increase aerobic endurance through activities that closely resemble their sport of choice. Objectives: The objectives of this meta-analysis were to compare male youth soccer players’ adaptability to small-sided games vs. conventional endurance training and to establish exercise prescription guidelines for this population. Data Sources: The data sources utilised were Google Scholar, PubMed and Microsoft Academic. Study Eligibility Criteria: Studies were eligible for inclusion if interventions were carried out in male soccer players (aged 3 min. Study Appraisal and Synthesis Methods: The inverse-variance random-effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis whilst accounting for heterogeneity across studies. Effect sizes were represented by the standardised mean difference and presented alongside 95% confidence intervals. Results: Seven studies were included in this meta-analysis. Both modes of training were effective in increasing endurance performance. Within-mode effect sizes were both of moderate magnitude [small-sided games: 0.82 (95% confidence interval 0.05, 1.60), Z = 2.07 (p = 0.04); conventional endurance training: 0.89 (95% confidence interval 0.06, 1.72), Z = 2.10 (p = 0.04)]. There were only trivial differences [0.04 (95% confidence interval − 0.36, 0.43), Z = 0.18 (p = 0.86)] between the effects on aerobic endurance performance of small-sided games and conventional endurance training. Subgroup analyses showed mostly trivial differences between the training methods across key programming variables such as set duration (≥ or < 4 min) and recovery period between sets (≥ or < 3 min). Programmes that were longer than 8 weeks favoured small-sided games [effect size = 0.45 (95% confidence interval − 0.12, 1.02), Z = 1.54 (p = 0.12)], with the opposite being true for conventional endurance training [effect size = − 0.33 (95% confidence interval − 0.79, 0.14), Z = 1.39 (p = 0.16)]. Programmes with more than 4 sets per session favoured small-sided games [effect size = 0.53 (95% confidence interval − 0.52, 1.58), Z = 0.98 (p = 0.33)] with only a trivial difference between those with 4, or fewer, sets [effect size = − 0.13 (95% confidence interval − 0.52, 0.26), Z = 0.65 (p = 0.52)]. Conclusions: Small-sided games are as effective as conventional endurance training for increasing aerobic endurance performance in male youth soccer players. This is important for practitioners as it means that small-sided games can allow both endurance and skills training to be carried out simultaneously, thus providing a more efficient training stimulus. Small-sided games offer the same benefits as conventional endurance training with two sessions per week, with ≥ 4 sets of 4 min of activity, interspersed with recovery periods of 3 min, recommended in this population

    Group versus Individualised Minimum Velocity Thresholds in the Prediction of Maximal Strength in Trained Female Athletes

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    This study examined the accuracy of di erent velocity-based methods in the prediction of bench press and squat one-repetition maximum (1RM) in female athletes. Seventeen trained females (age 17.8 1.3 years) performed an incremental loading test to 1RM on bench press and squat with the mean velocity being recorded. The 1RM was estimated from the load–velocity relationship using the multiple- (8 loads) and two-point (2 loads) methods and group and individual minimum velocity thresholds (MVT). No significant e ect of method, MVT or interaction was observed for the two exercises (p > 0.05). For bench press and squat, all prediction methods demonstrated very large to nearly perfect correlations with respect to the actual 1RM (r range = 0.76 to 0.97). The absolute error (range = 2.1 to 3.8 kg) for bench press demonstrated low errors that were independent of the method and MVT used. For squat, the favorable group MVT errors for the multiple- and two-point methods (absolute error = 7.8 and 9.7 kg, respectively) were greater than the individual MVT errors (absolute error = 4.9 and 6.3 kg, respectively). The 1RM can be accurately predicted from the load–velocity relationship in trained females, with the two-point method o ering a quick and less fatiguing alternative to the multiple-point method

    Investigating the Cosmic-Ray Ionization Rate Near the Supernova Remnant IC 443 Through H3+ Observations

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    Observational and theoretical evidence suggests that high-energy Galactic cosmic rays are primarily accelerated by supernova remnants. If also true for low-energy cosmic rays, the ionization rate near a supernova remnant should be higher than in the general Galactic interstellar medium (ISM). We have searched for H3+ absorption features in 6 sight lines which pass through molecular material near IC 443---a well-studied case of a supernova remnant interacting with its surrounding molecular material---for the purpose of inferring the cosmic-ray ionization rate in the region. In 2 of the sight lines (toward ALS 8828 and HD 254577) we find large H3+ column densities, N(H3+)~3*10^14 cm^-2, and deduce ionization rates of zeta_2~2*10^-15 s^-1, about 5 times larger than inferred toward average diffuse molecular cloud sight lines. However, the 3 sigma upper limits found for the other 4 sight lines are consistent with typical Galactic values. This wide range of ionization rates is likely the result of particle acceleration and propagation effects, which predict that the cosmic-ray spectrum and thus ionization rate should vary in and around the remnant. While we cannot determine if the H3+ absorption arises in post-shock (interior) or pre-shock (exterior) gas, the large inferred ionization rates suggest that IC 443 is in fact accelerating a large population of low-energy cosmic rays. Still, it is unclear whether this population can propagate far enough into the ISM to account for the ionization rate inferred in diffuse Galactic sight lines.Comment: 14 pages, 3 figures, 4 table

    A Meta-Analysis of Resistance Training in Female Youth: Its Effect on Muscular Strength, and Shortcomings in the Literature

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    Background Resistance training is an effective way to enhance strength in female youth but, to date, no researcher has meta-analysed its effect on muscular strength in that population. Objectives This meta-analysis characterised female youths’ adaptability to resistance training (RT). A second objective was to highlight the limitations of the body of literature with a view to informing future research. Data Sources Google Scholar, PubMed, Web of Science. Study Eligibility Criteria Resistance training interventions in healthy females with a mean age between 8 and 18 years. Programmes of between 4 and 16 weeks’ duration that included a control group. Study Appraisal and Synthesis Methods The inverse-variance random effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis whilst accounting for heterogeneity across studies. Effect sizes, calculated from a measure of muscular strength, are represented by the standardised mean difference and are presented alongside 95% confidence intervals. Results The magnitude of the main effect was ‘small’ (0.54, 95% confidence interval: 0.23–0.85). Effect sizes were larger in older (> 15 years; ES = 0.72 [0.23–1.21] vs. 0.38 [− 0.02–0.79]), taller (> 163 cm; ES = 0.67 [0.20–1.13] vs. 0.55 [0.08–1.02]) and heavier (< 54 kg; ES = 0.67 [0.30–1.03] vs. 0.53 [− 0.00–1.06]) participants. Conclusions and Implications of Key Findings Resistance training is effective in female youth. These findings can be used to inform the prescription of RT in female youth

    Scattering of energetic particles by anisotropic magnetohydrodynamic turbulence with a Goldreich-Sridhar power spectrum

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    Scattering rates for a Goldreich-Sridhar (GS) spectrum of anisotropic, incompressible, magnetohydrodynamic turbulence are calculated in the quasilinear approximation. Because the small-scale fluctuations are constrained to have wave vectors nearly perpendicular to the background magnetic field, scattering is too weak to provide either the mean free paths commonly used in Galactic cosmic-ray propagation models or the mean free paths required for acceleration of cosmic rays at quasi-parallel shocks. Where strong pitch-angle scattering occurs, it is due to fluctuations not described by the GS spectrum, such as fluctuations generated by streaming cosmic rays.Comment: 5 pages, 1 figure, to appear in Physical Review Letters. Minor changes in wording and grammar from version 2. Like version 2, this version discusses relevance of magnetic-moment conservation to non-resonant scattering. All equations are the same as in version
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