2,556 research outputs found

    The effectiveness of progressive and traditional coaching strategies to improve sprint and jump performance across varying levels of maturation within a general youth population

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    Literature pertaining to youth development has identified the importance of understanding the physical, intellectual and emotional needs of adolescents prior to, during, and after their peak height velocity (PHV) period. The purpose of this study was to compare the use of a ‘traditional’ and ‘progressive’ coaching style to train a general male youth population to improve sprint and jump performances whilst assessing enjoyment to comment on long-term application. Maximal sprint times, sprint kinematics, unilateral jump distances and repetitive tuck jump scores were measured alongside anthropometric variables to characterise performance. The results revealed significant (p < 0.05) pre/post differences in anthropometric variables across all maturation groups, and each of the maturational levels displayed a tendency to favor a particular coaching or control condition. Pre-PHV groups responded most effectively to the progressive style of coaching, displaying improvements in horizontal jump performances, and −0.7% to −2.7% improvements in all sprint times, despite also showing the largest increase in tuck jump scores (25.8%). The circa-PHV group produced their greatest improvements in the traditional intervention, as displayed through significant improvements (p < 0.05) in 20-m sprint times and dominant-leg horizontal jump performance, whilst also revealing the greatest deterioration in tuck jump scores (14.2%). Post-PHV displayed the greatest improvements in the control setting, suggesting that the natural benefits gained through adolescent development were greater than the influence of the training interventions. In conclusion, the results suggest that matching coaching strategies and delivery techniques to the period of biological maturation may have implications for both performance and athlete safety

    The effectiveness of progressive and traditional coaching strategies to improve iprint and jump performance across varying levels of maturation within a general youth population

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    Literature pertaining to youth development has identified the importance of understanding the physical, intellectual and emotional needs of adolescent youth. The purpose of this study was to compare the use of a ‘traditional’ and ‘progressive’ coaching style to train a general male youth population to improve sprint and jump performances, whilst assessing enjoyment to comment on long term application. Maximal sprint times, sprint kinematics, unilateral jump distances and repetitive tuck jump scores were measured alongside anthropometric variables to characterise performance. Results revealed significant (p>0.05) pre/post differences in anthropometric variables across all maturation groups, and each of the maturational levels displayed a tendency to favour a particular coaching or control condition. Pre-PHV groups responded most effectively to the progressive style of coaching, displaying improvements in horizontal jump performances, and -0.7 to -2.7% improvements in all sprint times, despite also showing the largest increase in tuck jump scores (25.8%). The circa-PHV group produced their greatest improvements in the traditional intervention, as displayed through significant improvements (p<0.05) in 20m sprint times and dominant-leg horizontal jump performance, whilst also revealing the greatest deterioration in tuck jump scores (14.2%). Post-PHV displayed the greatest improvements in the control setting, suggesting the natural benefits gained through adolescent development were greater than the influence of the training interventions. In conclusion, it is suggested that matching coaching strategies and delivery techniques to the period of biological maturation may have implications for both performance and athlete safety

    An investigation into the impact of coaching strategies with respect to physical and performance characteristics of male youth of varying biological maturation

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    This thesis will be presented as two standalone experimental chapters which will culminate in a thesis discussion linking the two papers under the overarching concept of maturation in male youth. Chapter 2 is currently under review in ‘Cogent Medicine’, and the intention of Chapter 2 is to identify physical, injury and performance-based differences between maturational groups within a general school-based population of 8 youth. These observed differences within Chapter 2 will then inform the methodology and coaching strategies utilised within Chapter 3, which will investigate the effectiveness of various coaching methods in order to maximise adaptation, motor ability and injury prevention within each maturational group. The outcome of this thesis hopes to inform practitioners as to how they can best implement their training programmes to maximise learning and adaptation across a range of biological maturation levels. Rather than just knowing when training should occur which has been investigated previously, it is hoped this thesis will provide insight into how coaching should occur to maximise learning within this diverse adolescent population. Due to the layout of this thesis with the individual papers, there is an element of content repetition throughout Chapters 1,2,3 and 4 which needs to be acknowledged, although the various contexts provides uniqueness throughout

    Generation of spin-motion entanglement in a trapped ion using long-wavelength radiation

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    Applying a magnetic-field gradient to a trapped ion allows long-wavelength radiation to produce a mechanical force on the ion's motion when internal transitions are driven. We demonstrate such a coupling using a single trapped Yb+171 ion and use it to produce entanglement between the spin and motional state, an essential step toward using such a field gradient to implement multiqubit operations

    Does maturation influence functional performance in youth males?

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    Understanding the role biological maturity has on athletic motor skills may have implications for age based sporting selection. During adolescence, peak height velocity provides an indication of biological maturity and the physiological adaptations that occur during this period, which can have varying implications on motor skill acquisition and functional performance. With rapid physical changes and a loss of neuromuscular control during stages of biological maturation, the risk of muscular and/or structural injury is increased. The purpose of this study was to identify the influence maturation has on functional performance in youth males. A cross sectional sample of 97 youth males were allocated into maturation groups which were assessed using non-invasive predictive methods. Participants performed three maximal 20m sprints, unilateral horizontal jumps and a 10s bilateral tuck jump (TJ) assessment. A one way ANOVA was utilized to assess between and within group differences. Pearson’s correlations between maturity offset and performance variables were also calculated. Anthropometric data revealed significant differences (p<0.05) in all measured variables between maturation groups. Significant group differences (p<0.01) revealed increased maturation status positively influenced speed performances (ES = 0.64 to 1.03) but not jump performances. TJ scores identified no significant differences between group means. Data suggests physiological improvements in strength and power post PHV will likely have positive implications on force application and technical efficiency within sprint events. Investigations into the relationships between step length, step frequency and contact time between maturation groups are recommended for future studies, with emphasis on utilising neuromuscular training to decrease the risk of injury throughout the PHV period

    Does maturation influence functional performance in youth males?

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    Introduction: Understanding the role biological maturity has on athletic motor skills may have implications for athlete development programmes. The purpose of this study was to identify the influence maturation has on functional performance in youth males. Methods: A cross sectional sample of 97 youth males (Age range 13.2 to 15.7 years old with a maturity offset of -1.0 to 2.6 years) were allocated into either pre, circa, or post PHV maturation groups. Participants performed 20m sprint, unilateral horizontal jump, and a 10s bilateral tuck jump (TJ) assessments. Results: Significant group differences (p<0.01) revealed increased maturation status positively influenced speed performances (ES = 0.64 to 1.03) but not jump performances. Associations between speed performances and horizontal jump performances were large to very large (r=-0.67 to -0.74). Discussion: Maturation status appears to influence speed especially over 10m and 20m but not initial acceleration or jump capability, despite the strong associations between speed and horizontal jump performances. Take home message: It appears there is a need to consider biological maturity when determining speed characteristics in male youths

    Ground-state cooling of a trapped ion Using long-wavelength radiation

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    We demonstrate ground-state cooling of a trapped ion using radio-frequency (rf) radiation. This is a powerful tool for the implementation of quantum operations, where rf or microwave radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of n¯=0.13(4) after sideband cooling, corresponding to a ground-state occupation probability of 88(7)%. After preparing in the vibrational ground state, we demonstrate motional state engineering by driving Rabi oscillations between the |n=0⟩ and |n=1⟩ Fock states. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost 2 orders of magnitude compared with our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system

    Investigating soil-water retention characteristics at high suctions using Relative Humidity control

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    A technique for controlling relative humidity (RH) is presented, which involves supplying a sealed chamber with a continuous flow of air at a computer-regulated RH. The desired value of RH is achieved by mixing dry and wet air at appropriate volumes and is measured for servo-control at three locations in the chamber with capacitive RH sensors and checked with a sensitive VAISALA sensor. The setup is capable of controlling RH steadily and continuously with a deviation of less than 0.2% RH. The technique was adopted to determine wetting soil-water retention curves (SWRC) of statically compacted London Clay, under both free-swelling and constant volume conditions. The RH within the chamber was increased in a step-wise fashion, with each step maintained until vapour equilibrium between the chamber atmosphere and the soil samples was established. Independent filter paper measurements further validate the method, while the obtained retention curves complement those available in the literature for lower ranges of suction

    Grassroots responses to violence against women and girls in post-earthquake Nepal: lessons from the field

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    Violence against women and girls (VAWG), including sexual violence, can increase after natural disasters. This article provides evidence from Nepal, a country where progress has been made on gender equality but VAWG remains an endemic problem. Research since the earthquakes involving women activists and non-government organisations indicates the continuing challenges facing disaster response efforts to prevent VAWG and protect women. Women and girls in camps and temporary shelters feel threatened and insecure due to the risk of violence and lack of privacy. Humanitarian aid, health care, and disaster responses can challenge VAWG, and offer safe spaces for women and girls to be established. This article draws on the views of grassroots women’s activists in Nepal and shares lessons for development and humanitarian workers about steps to be taken to challenge and minimise VAWG in emergency situations. © 2016 Oxfam GB
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