The effect of session order on the physiological, neuromuscular, and endocrine responses to maximal speed and weight training sessions over a 24-h period

Objectives: Athletes are often required to undertake multiple training sessions on the same day with these sessions needing to be sequenced correctly to allow the athlete to maximize the responses of each session. We examined the acute effect of strength and speed training sequence on neuromuscular, endocrine, and physiological responses over 24 hours. Design: 15 academy rugby union players completed this randomized crossover study. Method: Players performed a weight traiing session followed 2 hours later by a speed training session (WS) and on a separate day reversed the order (SW). Countermovement jumps (CMJ), perceived muscle soreness (MS), and blood samples were collected immediately prior, immediately post, and 24 hours post sessions one and two respectively. Jumps were analyzed for power, jump height, rate of force development, and velocity. Blood was analyzed for testosterone (T), cortisol (C), lactate and creatine kinase (CK). Results: There were no differences between CMJ variables at any of the post training time points (p > 0.05). Likewise, CK, T, C , and MS were unaffected by session order (p > 0.05). However, 10 meter sprint time was significantly faster (Mean ± SD; SW 1.80s ± 0.11 vs. WS 1.76 ± 0.08s; p > 0.05) when speed was sequenced second. Lactate levels were significantly higher immediately post speed sessions versus weight training sessions at both time points (p < 0.05). Conclusions: The sequencing of strength and speed training does not affect the neuromuscular, endocrine, and physiological recovery over 24 hours. However, speed may be enhanced when performed as the second session

The application of noble gases and carbon stable isotopes in tracing the fate, migration and storage of CO2

The noble gases (He, Ne, Ar, Kr and Xe) are present in trace quantities in all natural and engineered CO2. They have proved to be extremely powerful tracers of both the CO2 source, and when combined with carbon stable isotopes, the subsurface processes that control the fate of CO2. Here we present a summary of the progress made over the past decade in using noble gases and stable carbon isotope tracing techniques in CO2 storage studies. We outline the initial lessons which were learnt from the study of natural CO2 reservoirs, then show the recent progress that has been made in tracing CO2 injected into a CO2-EOR field. We show the application of noble gases in determining natural CO2 leakage to the shallow groundwater and their use in successfully refuting the allegations of CO2 leakage made at the Weyburn CO2-EOR project. Our results illustrate that good progress has been made in using noble gases to determine both the short-term and long-term fate of CO2 in the subsurface and in the determination of the extent of groundwater interaction that the injected CO2 has undergone. However, there are still outstanding questions, particularly regarding the exact behaviour of the noble gases compared to CO2 and we show preliminary results from a laboratory study to investigate how noble gas transport through real rock compares to that of CO2

The effectiveness of injury prevention programs to modify risk factors for non-contact anterior cruciate ligament and hamstring injuries in uninjured team sports athletes: A systematic review

Background Hamstring strain and anterior cruciate ligament injuries are, respectively, the most prevalent and serious non-contact occurring injuries in team sports. Specific biomechanical and neuromuscular variables have been used to estimate the risk of incurring a non-contact injury in athletes. Objective The aim of this study was to systematically review the evidences for the effectiveness of injury prevention protocols to modify biomechanical and neuromuscular anterior cruciate and/or hamstring injuries associated risk factors in uninjured team sport athletes. Data Sources PubMed, Science Direct, Web of Science, Cochrane Libraries, U.S. National Institutes of Health clinicaltrials.gov, Sport Discuss and Google Scholar databases were searched for relevant journal articles published until March 2015. A manual review of relevant articles, authors, and journals, including bibliographies was performed from identified articles. Main Results Nineteen studies were included in this review. Four assessment categories: i) landing, ii) side cutting, iii) stop-jump, and iv) muscle strength outcomes, were used to analyze the effectiveness of the preventive protocols. Eight studies using multifaceted interventions supported by video and/or technical feedback showed improvement in landing and/or stop-jump biomechanics, while no effects were observed on side-cutting maneuver. Additionally, multifaceted programs including hamstring eccentric exercises increased hamstring strength, hamstring to quadriceps functional ratio and/or promoted a shift of optimal knee flexion peak torque toward a more open angle position. Conclusions Multifaceted programs, supported by proper video and/or technical feedback, including eccentric hamstring exercises would positively modify the biomechanical and or neuromuscular anterior cruciate and/or hamstring injury risk factors

Geochemical tracers for monitoring offshore CO2 stores

Chemical tracers are proposed as an effective means of detecting, attributing and quantifying any CO2 leaks to surface from geological CO2 storage sites, a key component of Carbon Capture and Storage (CCS) technology. A significant proportion of global CO2 storage capacity is located offshore, with some regions of the world having no onshore stores. To assure regulatory bodies and the public of CO2 storage integrity it is important to demonstrate that robust offshore monitoring systems are in place. A range of chemical tracers for leakage have been tested at onshore pilot CCS projects worldwide, but to date they have not been trialled at injection projects or CO2 release experiments located offshore. Here, for the first time, we critically review the current issues surrounding commercial scale use of tracers for offshore CCS projects, and examine the constraints and cost implications posed by the marine environment. These constraints include the logistics of sampling for tracers offshore, the fate of tracers in marine environments, tracer background levels, marine toxicity and legislative barriers – with particular focus on the Europe and the UK. It is clear that chemicals that form a natural component of the CO2 stream are preferable tracers for ease of permitting and avoiding cost and risks of procuring and artificially adding a tracer. However, added tracers offer more reliability in terms of their unique composition and the ability to control and regulate concentrations. We identify helium and xenon isotopes (particularly 124,129Xe), and artificial tracers such as PFCs and deuterated methane as the most suitable added tracers. This is due to their conservative behaviour, low environmental impact and relative inexpense. Importantly, we also find that SF6 and C14 are not viable tracers for CCS due to environmental concerns, and many other potential tracers can be ruled out on the basis of cost. Further, we identify key challenges that are unique to using tracers for offshore monitoring, and highlight critical uncertainties that future work should address. These include possible adsorption or dispersion of tracer compounds during ascent through the overburden, longevity of tracers over the timeframes relevant for CCS monitoring, the permissible environmental effects of tracer leakage, and tracer behaviour in seabed CO2 bubble streams and in dissolved CO2. These uncertainties directly affect the selection of appropriate tracers, the injection programme and concentrations necessary for their reliable detection, and appropriate sampling approaches. Hence offshore tracer selection and associated expense are currently poorly constrained. Further, there is limited experience of sampling for tracers in the marine environment; current approaches are expensive and must be streamlined to enable affordable monitoring strategies. Further work is necessary to address these unknowns so as to evaluate the performance of potential tracers for CO2 leak quantitation and provide more accurate costings for effective offshore tracer monitoring programmes

Contested control : an ethnographic study of policing a metropolis

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

The effect of session order on the physiological, neuromuscular, and endocrine responses to maximal speed and weight training sessions over a 24-h period

Objectives: Athletes are often required to undertake multiple training sessions on the same day with these sessions needing to be sequenced correctly to allow the athlete to maximize the responses of each session. We examined the acute effect of strength and speed training sequence on neuromuscular, endocrine, and physiological responses over 24 h. Design: 15 academy rugby union players completed this randomized crossover study. Methods: Players performed a weight training session followed 2 h later by a speed training session (weights speed) and on a separate day reversed the order (speed weights). Countermovement jumps, perceived muscle soreness, and blood samples were collected immediately prior, immediately post, and 24 h post-sessions one and two respectively. Jumps were analyzed for power, jump height, rate of force development, and velocity. Blood was analyzed for testosterone, cortisol, lactate and creatine kinase. Results: There were no differences between countermovement jump variables at any of the post-training time points (p &gt; 0.05). Likewise, creatine kinase, testosterone, cortisol, and muscle soreness were unaffected by session order ( 0.05). Likewise, creatine kinase, testosterone, cortisol, and muscle soreness were unaffected by session order (p &gt; 0.05). However, 10 m sprint time was significantly faster (mean ± standard deviation; speed weights 1.80 ± 0.11 s versus weights speed 1.76 ± 0.08 s; 0.05). However, 10 m sprint time was significantly faster (mean ± standard deviation; speed weights 1.80 ± 0.11 s versus weights speed 1.76 ± 0.08 s; p &gt; 0.05) when speed was sequenced second. Lactate levels were significantly higher immediately post-speed sessions versus weight training sessions at both time points ( 0.05) when speed was sequenced second. Lactate levels were significantly higher immediately post-speed sessions versus weight training sessions at both time points (p Conclusions: The sequencing of strength and speed training does not affect the neuromuscular, endocrine, and physiological recovery over 24 h. However, speed may be enhanced when performed as the second session