Search

Environmental heat stress can negatively impact health, work capacity, and athletic performance and potentially to lead to life-threatening consequences if not mitigated. With the upcoming Toyko Olympic games to be held during anticipated warm ambient temperatures (up to 29°C), and with spectators potentially spending long durations of time outdoors, certain populations of persons with impaired thermoregulatory capacity will be at higher risk of heat-related illness from passive heat stress. Persons with spinal cord injury (SCI) are one of these groups as a result of a decentralized sympathetic nervous system, which leaves them with impairment in convective and evaporative cooling via vasodilation and sweating, respectively. This review summarizes (1) thermoregulatory physiological responses of persons with SCI under passive heat stress: the effect of level and completeness of injury; (2) the impact of passive heat stress on quality of life (QOL), outdoor participation, behavioral thermoregulation, and cognition; (3) recommendations and education for clinicians providing health care for persons with SCI; and (4) suggestions of future directions for exploring the gaps in the literature on passive heat stress in persons with SCI. This article aims to equip consumers with SCI and health-care professionals with the most up-to-date knowledge on passive heat stress responses in persons with SCI, so that their attendance at the Olympic games can be done with maximal safety and enjoyment.

The aim of this study was to determine the physiological demands of epee fencing performance. Eight elite male epee fencers competed in a competition consisting of 7 Poule and 7 Direct Elimination ...

The purpose of this study was to assess the association between muscle thickness and echo intensity of the knee extensors and ankle plantarflexors with postural sway, mobility and physical function in older adults. Twenty-one older men and women (age; 69.9 ± 4.3 years) were assessed for postural sway (centre of pressure movement), mobility (i.e. Timed-Up and-Go-test [TUG]), physical function (i.e. 5 times sit-to-stand [STS]), and ultrasound derived measures of muscle thickness and echo intensity of the vastus lateralis (VL) and gastrocnemius medialis (GM). Significant inverse correlations were observed between VL and GM thickness with TUG (r = −0.432 to −0.492) and STS (r = −0.473 to −0.596). Significant positive correlations were observed between VL and GM echo intensity with TUG (r = 0.459 to 0.518) and STS (r = 0.481 to 0.635). Significant positive correlations were also detected between GM echo intensity and anteroposterior sway (r = 0.451 to 0.534). Two key findings emerged from the present experiment. First, this study provides novel evidence that ankle plantarflexor echo intensity, but not thickness, was associated with anteroposterior postural sway among older adults. Second, we provide new evidence that muscle thickness and echo intensity of the knee extensors and uniquely, the ankle plantarflexors, presented with similar magnitude associations with TUG and STS performance in older adults.

Transient symptoms of muscle damage emanating from unaccustomed eccentric exercise can adversely affect muscle function and potentially increase the risk of falling for several days. Therefore, the aims of the present study were to investigate the shorter- and longer-lasting temporal characteristics of muscle fatigue and damage induced by level (i.e., concentrically biased contractions) or downhill (i.e., eccentrically biased contractions) walking on postural, physical, and muscular functions in older people. Nineteen participants were matched in pairs for sex, age and self-selected walking speed and allocated to a level (n = 10, age = 72.3 ± 2.9 years) or downhill (n = 9, age = 72.1 ± 2.2 years) walking group. Postural sway, muscle torque and power, physical function (5× and 60 s sit-to-stand; STS), and mobility (Timed-Up-and-Go; TUG) were evaluated at baseline (pre-exercise), 1 min, 15 min, 30 min, 24 h, and 48 h after 30 min of level (0% gradient) or downhill (−10% gradient) walking on a treadmill. Following downhill walking, postural sway (+66 to 256%), TUG (+29%), 60 s STS (+29%), five times STS (−25%) and concentric power (−33%) did not change at 1–30 min post exercise, but were significantly different (p < 0.05) at 24 and48 h post-exercise when compared to baseline (p < 0.05). Muscle torque decreased immediately after downhill walking and remained impaired at 48 h post-exercise (−27 to −38%). Immediately following level walking there was an increase in postural sway (+52 to +98%), slower TUG performance (+29%), fewer STS cycles in 60 s (−23%), slower time to reach five STS cycles (+20%) and impaired muscle torque (−23%) and power (−19%) which returned to baseline 30-min after exercise cessation (p > 0.05). These findings have established for the first time distinct impairment profiles between concentric and eccentric exercise. Muscle damage emanating from eccentrically biased exercise can lead to muscle weakness, postural instability and impaired physical function persisting for several days, possibly endangering older adult’s safety during activities of daily living by increasing the risk of falls.

This study examined postural sway in children in eyes open (EO) and eyes closed (EC) conditions, controlling for body mass index (BMI) and physical activity (PA). Sixty two children (aged 8–11years) underwent sway assessment using computerized posturography from which 95% ellipse sway area, anterior/posterior (AP) sway, medial/lateral (ML) sway displacement and sway velocity were assessed. Six trials were performed alternatively in EO and EC. BMI (kg/m2) was determined from height and mass. PA was determined using sealed pedometry. AP amplitude (p = .038), ML amplitude (p = .001), 95% ellipse (p = .0001), and sway velocity (p = .012) were higher in EC compared with EO conditions. BMI and PA were not significant as covariates. None of the sway variables were significantly related to PA. However, sway velocity during EO (p = .0001) and EC (p = .0001) was significantly related to BMI. These results indicate that sway is poorer when vision is removed, that BMI influences sway velocity, but that pedometer-assessed PA was not associated with postural sway.

Objectives: Athletes with high level spinal cord injuries (tetraplegia) are under greater thermal strain during exercise than the able-bodied. The purpose of this study was to investigate the effectiveness of pre-cooling using an ice vest and the combination of pre-cooling and cooling during play using water sprays in athletes with tetraplegia.\ud \ud Design: Counter-balanced, cross-over design.\ud \ud Methods: Eight wheelchair rugby players with tetraplegia completed a 60 min intermittent sprint protocol (ISP) on a wheelchair ergometer in 20.2 °C ± 0.2 °C and 33.0% ± 3.1% relative humidity. The ISP was conducted on three occasions; no cooling (NC), pre-cooling with an ice vest (P) and pre-cooling with an ice vest and water sprays between quarters (PW). Gastrointestinal (Tgi) temperature, mean skin temperature (Tsk) and perceptual responses were measured throughout.\ud \ud Results: At the end of pre-cooling, the change in Tgi was not significantly different between conditions (P > 0.05) but the change in Tsk was significantly greater in P and PW compared to NC (P < 0.001). The change in Tgi over the ISP was significantly lower in PW and P compared to NC (P < 0.05), whilst the change in Tsk was lower in PW compared to P and NC (P < 0.05). Cooling had no effect on performance or perceptual responses (P > 0.05).\ud \ud Conclusions: Water spraying between quarters combined with pre-cooling using an ice vest lowers thermal strain to a greater degree than pre-cooling only in athletes with tetraplegia, but has no effect on simulated wheelchair rugby performance or perceptual responses.

Presented in this infographic is a summary of studies investigating the thermoregulatory impairment of athletes with a spinal cord injury during real-world sporting scenarios. The infographic depicts the heightened thermal strain experienced by athletes with tetraplegia (high level lesions), both compared to athletes with paraplegia (low level lesions) and within the sport of wheelchair rugby. In addition to the cooling interventions presented, the infographic highlights the significant need for appropriate interventions to reduce the risk of overheating and potential performance decrements. This infographic was field tested with those who work within a wheelchair sports environment, ranging from practitioners, researchers, athletes with an SCI and sports clinicians. The experimental studies were also designed in consultation with the wheelchair rugby coaches and players.

The aim of the study was to determine whether climatic limits for achieving heat balance at rest are affected by spinal cord injury (SCI). Twenty-three men [8 able-bodied (AB), 8 with paraplegia (PP), and 7 with tetraplegia (TP)] rested in 37°C and 20% relative humidity (RH) for 20 min. With the ambient temperature held constant, RH was increased by 5% every 7 min, until gastrointestinal temperature (Tgi) showed a clear inflection or increased by >1°C. Tgi, skin temperatures, perceptual responses, and metabolic energy expenditure were measured throughout. Metabolic heat production [AB: 123 (21) W, PP: 111 (15) W, TP: 103 (29) W; means (SD)] and required rate of evaporative cooling for heat balance [Ereq; AB: 113 (20) W, PP: 107 (17) W, TP: 106 (29) W] were similar between groups ( P = 0.22 and P = 0.79). Compared with AB, greater increases in Tgi were observed in TP ( P = 0.01), with notable increases in mean skin temperature (Tsk) for TP and PP ( P = 0.01). A Tgi inflection point was demonstrated by seven AB, only three of eight PP, and no TP. Despite metabolic heat production (and Ereq) being similar between groups, evaporative heat loss was not large enough to obtain heat balance in TP, linked to a shortfall in evaporative cooling potential. Although PP possess a greater sweating capacity, the continual increase in Tgi and Tsk in most PP, although lower than for TP, implies that latent heat loss for PP is also insufficient to attain heat balance. NEW & NOTEWORTHY In the absence of convective heat loss, at temperatures around 37°C evaporative heat loss is insufficient to attain heat balance at rest in individuals with paraplegia and tetraplegia. This finding was directly linked to a shortfall in evaporative cooling potential compared with required evaporative cooling. In this environment, individuals with both paraplegia and tetraplegia cannot subjectively determine the magnitude of their thermal strain; thus perceptual responses should not be relied upon for this population group.

International sporting competitions, including the Paralympic Games, are increasingly being held in hot and/or humid environmental conditions. Thus, a greater emphasis is being placed on preparing athletes for the potentially challenging environmental conditions of the host cities, such as the upcoming Games in Tokyo in 2020. However, evidence-based practices are limited for the impairment groups that are eligible to compete in Paralympic sport. This review aims to provide an overview of heat-related issues for Paralympic athletes alongside current recommendations to reduce thermal strain and technological advancements in the lead up to the Tokyo 2020 Paralympic Games. When competing in challenging environmental conditions, a number of factors may contribute to an athlete's predisposition to heightened thermal strain. These include the characteristics of the sport itself (type, intensity, duration, modality, and environmental conditions), the complexity and severity of the impairment and classification of the athlete. For heat vulnerable Paralympic athletes, strategies such as the implementation of cooling methods and heat acclimation can be used to combat the increase in heat strain. At an organizational level, regulations and specific heat policies should be considered for several Paralympic sports. Both the utilization of individual strategies and specific heat health policies should be employed to ensure that Paralympics athletes' health and sporting performance are not negatively affected during the competition in the heat at the Tokyo 2020 Paralympic Games.

Physiological responses to arm and leg-cycling are different, which may influence psychological and biological mechanisms that influence post-exercise cognitive performance. The aim of this study was to determine the effects of maximal and submaximal (absolute and relative intensity matched) arm and leg-cycling on executive function. Thirteen males (age, 24.7 ± 5.0 years) initially undertook two incremental exercise tests to volitional exhaustion for arm-cycling (82 ± 18 W) and leg-cycling (243 ± 52 W) for the determination of maximal power output. Participants subsequently performed three 20-min constant load exercise trials: (1) arm-cycling at 50% of the ergometer-specific maximal power output (41 ± 9 W), (2) leg-cycling at 50% of the ergometer-specific maximal power output (122 ± 26 W), and (3) leg-cycling at the same absolute power output as the submaximal arm-cycling trial (41 ± 9 W). An executive function task was completed before, immediately after and 15-min after each exercise test. Exhaustive leg-cycling increased reaction time (p < 0.05, d = 1.17), while reaction time reduced following exhaustive arm-cycling (p < 0.05, d = -0.62). Improvements in reaction time were found after acute relative intensity arm (p < 0.05, d = -0.76) and leg-cycling (p < 0.05, d = -0.73), but not following leg-cycling at the same absolute intensity as arm-cycling (p > 0.05). Improvements in reaction time following arm-cycling were maintained for at least 15-min post exercise (p = 0.008, d = -0.73). Arm and leg-cycling performed at the same relative intensity elicit comparable improvements in cognitive performance. These findings suggest that individuals restricted to arm exercise possess a similar capacity to elicit an exercise-induced cognitive performance benefit.

© 2016 Informa UK Limited, trading as Taylor & Francis Group The purpose of this study was to compare arm–leg coordination and kinematics during 100 m breaststroke in 26 (8 female; 18 male) specialist breaststroke swimmers. Laps were recorded using three 50-Hz underwater cameras. Heart rate and blood lactate were measured pre- and post-swim. Arm–leg coordination was defined using coordination phases describing continuity between recovery and propulsive phases of upper and lower limbs: coordination phase 1 (time between end of leg kick and start of the arm pull phases); and coordination phase 2 (time between end of arm pull and start of leg kick phases). Duration of stroke phases, coordination phases, swim velocity, stroke length (SL), stroke rate (SR) and stroke index (SI) were analysed during the last three strokes of each lap that were unaffected by turning or finishing. Significant changes in velocity, SI and SL (P

The purpose of this study was to investigate whether high-intensity cycling training leads to adapted responses of balance performance in response to exercise-induced muscle fatigue. Eighteen healthy adults were assigned to either 3-weeks (n = 8, age 20.1 ± 2.6 years, height 177 ± 5 cm, mass 73.6 ± 5.1 kg) or 6-weeks (n = 10, age 24.3 ± 5.8 years, height 179 ± 6 cm, mass 81.0 ± 15.8 kg) of high-intensity training (HIT) on a cycle ergometer. The centre of pressure (COP) displacement in the anteroposterior (COPAP) direction and COP path length (COPL) were measured before and after the first and final high-intensity training sessions. Pre-training, exercise-induced fatigue elicited an increase in COPAP (3-weeks; p = 0.001, 6-weeks; p = 0.001) and COPL (3-weeks; p = 0.002, 6-weeks; p = 0.001) returning to pre-exercise levels within 10-min of recovery. Following 3-weeks of training, significant increases in COPAP (p = 0.001) and COPL (p = 0.002) were observed post-fatigue, returning to pre-exercise levels after 15-min of recovery. After 6-weeks of training no significant increases in sway (COPAP; p = 0.212, COPL; p = 0.998) were observed following exercise-induced fatigue. In summary, 3 weeks of HIT resulted in longer recovery times following fatigue compared to pre-training assessments. After 6 weeks of HIT, postural sway following fatigue was attenuated. These results indicate that HIT could be included in injury prevention programmes, however, caution should be taken during early stages of the overreaching process.

This study evaluated the effects of ingesting sodium bicarbonate (NaHCO3) or caffeine individually or in combination on high-intensity cycling capacity. In a counterbalanced, crossover design, 13 healthy, noncycling trained males (age: 21 ± 3 years, height: 178 ± 6 cm, body mass: 76 ± 12 kg, peak power output (Wpeak): 230 ± 34 W, peak oxygen uptake: 46 ± 8 mL·kg−1·min−1) performed a graded incremental exercise test, 2 familiarisation trials, and 4 experimental trials. Trials consisted of cycling to volitional exhaustion at 100% Wpeak (TLIM) 60 min after ingesting a solution containing either (i) 0.3 g·kg−1 body mass sodium bicarbonate (BIC), (ii) 5 mg·kg−1 body mass caffeine plus 0.1 g·kg−1 body mass sodium chloride (CAF), (iii) 0.3 g·kg−1 body mass sodium bicarbonate plus 5 mg·kg−1 body mass caffeine (BIC-CAF), or (iv) 0.1 g·kg−1 body mass sodium chloride (PLA). Experimental solutions were administered double-blind. Pre-exercise, at the end of exercise, and 5-min postexercise blood pH, base excess, and bicarbonate ion concentration ([HCO3−]) were significantly elevated for BIC and BIC-CAF compared with CAF and PLA. TLIM (median; interquartile range) was significantly greater for CAF (399; 350–415 s; P = 0.039; r = 0.6) and BIC-CAF (367; 333–402 s; P = 0.028; r = 0.6) compared with BIC (313: 284–448 s) although not compared with PLA (358; 290–433 s; P = 0.249, r = 0.3 and P = 0.099 and r = 0.5, respectively). There were no differences between PLA and BIC (P = 0.196; r = 0.4) or between CAF and BIC-CAF (P = 0.753; r = 0.1). Relatively large inter- and intra-individual variation was observed when comparing treatments and therefore an individual approach to supplementation appears warranted.

BACKGROUND The purpose of this study was to determine the cardiorespiratory demands of standing and wheelchair (seated) fencing in a group of able-bodied fencers during simulated competitive bouts. METHODS Participants were ten male able-bodied fencers of regional level with previous training experience in wheelchair fencing. After a standardized warm-up, participants performed two series of simulated competitive epee bouts (5 and 15 touches) in a random order, either while standing or while sitting in a wheelchair. Expired gas was analyzed for oxygen consumption (VO2) and respiratory exchange ratio (RER) and heart rate were continually monitored. Energy expenditure (EE) was subsequently calculated. RESULTS VO2, HR and EE peak responses were greater during standing than seated fencing (P

Nevin, JP, Smith, P, Waldron, M, Patterson, S, Price, M, Hunt, A, and Blagrove, R. Efficacy of an 8-week concurrent strength and endurance training program on hand cycling performance. J Strength Cond Res 32(7): 1861-1868, 2018-The aim of this study was to investigate the effects of an 8-week concurrent strength and endurance training program in comparison with endurance training only on several key determinants of hand cycling performance. Five H4 and 5 H3 classified hand cyclists with at least 1 year's hand cycling training history consented to participate in the study. Subjects underwent a battery of tests to establish body mass, body composition, V[Combining Dot Above]O2peak, maximum aerobic power, gross mechanical efficiency (GME), maximal upper-body strength, and 30-km time-trial performance. Subjects were matched into pairs based on 30-km time-trial performance and randomly allocated to either a concurrent strength and endurance or endurance training only, intervention group. After an 8-week training program based on a conjugated block periodization model, subjects completed a second battery of tests. A mixed model, 2-way analysis of variance revealed no significant changes between groups. However, the calculation of effect sizes (ESs) revealed that both groups demonstrated a positive improvement in most physiological and performance measures with subjects in the concurrent group demonstrating a greater magnitude of improvement in body composition (ES -0.80 vs. -0.22), maximal aerobic power (ES 0.97 vs. 0.28), GME (ES 0.87 vs. 0.63), bench press 1 repetition maximum (1RM) (ES 0.53 vs. 0.33), seated row 1RM (ES 1.42 vs. 0.43), and 30-km time-trial performance (ES -0.66 vs. -0.30). In comparison with endurance training only, an 8-week concurrent training intervention based on a conjugated block periodization model seems to be a more effective training regime for improving the performance capabilities of hand cyclists.

The purpose of this study was to investigate the effects of holding external loads on postural sway during upright stance across age decades. Sixty-five healthy adults (females, n = 35), aged 18-80 years were assessed in four conditions; (1) standing without holding a load, holding a load corresponding to 5% body mass in the (2) left hand, (3) right hand and (4) both hands. The centre of pressure (COP) path length and anteroposterior and mediolateral COP displacement were used to indirectly assess postural sway. External loading elicited reductions in COP measures of postural sway in older age groups only (P 0.05). No changes were observed in younger or intermediate aged adults (P 0.05). Holding external loads during standing is relevant to many activities of daily living (i.e. holding groceries). The reduction in postural sway may suggest this type of loading has a stabilising effect during quiet standing among older adults.

The purpose of this study was to determine whether a player’s physical impairment or activity profile was related to the amount of thermal strain experienced during wheelchair rugby match play. 17 elite wheelchair rugby players played a competitive match, whilst activity profiles, measures of core and skin temperature, heart rate and perceptual responses were taken. Players were divided into 2 groups depending on their physical impairment: players with a cervical spinal cord injury, (n=10) or non-spinal related physical impairment (n=7). Total distance was lower (4 842±324 vs. 5 541±316 m, p

SUMMARYPelvic inflammatory disease (PID) and more specifically salpingitis (visually confirmed inflammation) is the primary cause of tubal factor infertility and is an important risk factor for ectopic pregnancy. The risk of these outcomes increases following repeated episodes of PID. We developed a homogenous discrete-time Markov model for the distribution of PID history in the UK. We used a Bayesian framework to fully propagate parameter uncertainty into the model outputs. We estimated the model parameters from routine data, prospective studies, and other sources. We estimated that for women aged 35–44 years, 33·6% and 16·1% have experienced at least one episode of PID and salpingitis, respectively (diagnosed or not) and 10·7% have experienced one salpingitis and no further PID episodes, 3·7% one salpingitis and one further PID episode, and 1·7% one salpingitis and ⩾2 further PID episodes. Results are consistent with numerous external data sources, but not all. Studies of the proportion of PID that is diagnosed, and the proportion of PIDs that are salpingitis together with the severity distribution in different diagnostic settings and of overlap between routine data sources of PID would be valuable.

The switch from an outcrossing mode of mating enforced by self-incompatibility to self-fertility in the Arabidopsis thaliana lineage was associated with mutations that inactivated one or both of the two genes that comprise the self-incompatibility (SI) specificity-determining S-locus haplotype, the S-locus receptor kinase (SRK) and the S-locus cysteine-rich (SCR) genes, as well as unlinked modifier loci required for SI. All analyzed A. thaliana S-locus haplotypes belong to the SA, SB, or SC haplotypic groups. Of these three, the SC haplotype is the least well characterized. Its SRKC gene can encode a complete open-reading frame, although no functional data are available, while its SCRC sequences have not been isolated. As a result, it is not known what mutations were associated with inactivation of this haplotype. Here, we report on our analysis of the Lz-0 accession and the characterization of its highly rearranged SC haplotype. We describe the isolation of its SCRC gene as well as the subsequent isolation of SCRC sequences from other SC-containing accessions and from the A. lyrata S36 haplotype, which is the functional equivalent of the A. thaliana SC haplotype. By performing transformation experiments using chimeric SRK and SCR genes constructed with SC- and S36-derived sequences, we show that the SRKC and SCRC genes of Lz-0 and at least a few other SC-containing accessions are nonfunctional, despite SCRC encoding a functional full-length protein. We identify the probable mutations that caused the inactivation of these genes and discuss our results in the context of mechanisms of S-locus inactivation in A. thaliana.

High ambient temperature and relative humidity (rh) are of great importance when considering athletic performance. Such factors are of particular interest when considering that the majority of Paralympic Games have been hosted at locations with potentially challenging environmental conditions (e.g., Atlanta, Sydney, Athens, Beijing) and a range of Paralympic athletes exhibit conditions manifesting thermal dysfunction. Prior to the Atlanta Games in 1996, Nielsen (1996) considered the “fight against physics” with respect to high ambient temperature (30–38°C) and relative humidity (rh; 40–80%) on endurance performance for able-bodied athletes. It was noted that with such potentially severe conditions outdoor endurance based performances could be severely reduced, especially in spells of high humidity. Strategies to prevent heat illness were recommended including events being scheduled at times of lower thermal stress or re-scheduled if temperatures were above 35°C. However, how these conditions may affect Paralympic athletes has not yet been reported. This article will consider what is known regarding enhancing (or maintaining) performance in the heat in athletes with motor disabilities in preparation for Rio 2016.

Introduction Asynchronous arm-cranking performed at high cadences elicits greater cardiorespiratory responses compared to low cadences. This has been attributed to increased postural demand and locomotor–respiratory coupling (LRC), and yet, this has not been empirically tested. This study aimed to assess the effects of cadence on cardiorespiratory responses and LRC during upper-body exercise. Methods Eight recreationally-active men performed arm-cranking exercise at moderate and severe intensities that were separated by 10 min of rest. At each intensity, participants exercised for 4 min at each of three cadences (50, 70, and 90 rev min−1) in a random order, with 4 min rest-periods applied in-between cadences. Exercise measures included LRC via whole- and half-integer ratios, cardiorespiratory function, perceptions of effort (RPE and dyspnoea), and diaphragm EMG using an oesophageal catheter. Results The prevalence of LRC during moderate exercise was highest at 70 vs. 50 rev min−1 (27 ± 10 vs. 13 ± 9%, p = 0.000) and during severe exercise at 90 vs. 50 rev min−1 (24 ± 7 vs. 18 ± 5%, p = 0.034), with a shorter inspiratory time and higher mean inspiratory flow (p

During upper body exercise the vascular adaptations of the leg have been reported to play an important thermoregulatory role. This study examined the effect of exercise intensity on thermoregulation during upper body exercise. Nine healthy male participants undertook an incremental exercise test on an arm crank ergometer to determine peak power (W peak ). The participants performed four experimental trials involving 5 minutes of arm exercise at either 45, 60, 75, or 90% Wpeak (70 rev.min -1 ) followed by 30 minutes of passive recovery. Aural and skin temperatures, upper arm and calf heat fl ow were recorded. Calf volume was measured during exercise using plethysmography. During exercise at 45, 60, 75 and 90% W peak calf volume decreased (P

It may be possible to use a single device to measure the in vivo dose delivered during radiotherapy, as well as to localize the target volume. This potential, as well as the detectors' ability to relate dosimetry and localization, were evaluated using two implantable MOSFET dosimeters placed inside an acrylic pelvic phantom. A wedged‐field photon plan and an eight‐field prostate treatment plan were developed. For each plan, conditions were simulated so that detectors were in their correct positions or slightly displaced to represent patient setup error and/or organ motion. Doses measured by the two detectors after irradiation were compared to those calculated by the treatment planning software. Additionally, using localization software and kilovoltage images of each setup, the displacement of the detectors from their correct locations was calculated and compared to the induced physical displacement. For all alignments and detector positions, measured and calculated doses showed an average disagreement of 2.7%. The detectors were easily visualized radiographically and the induced detector displacements were typically recognized by the localization software to within 0.1 cm. The implantable detector functioned well as both an internal dosimeter and as an internal fiducial marker, and thus may be useful as a clinical tool to localize the target volume and verify dose delivery in vivo. PACS numbers: 87.53.‐j 87.55.‐x

The commonly used thermoluminescent dosimeter TLD‐100 (Harshaw Chemical Company, Solon, OH) responds not only to photons and electrons, but also to neutrons that are produced during high‐energy therapies. As a result, TLD‐100 measurements outside of the treatment field are suspect when high‐energy radiation is used. Although alternatives such as TLD‐700 do not respond to neutrons, specialty dosimeters of this kind are expensive and are not routinely used in most clinics. In the current study, we examined the accuracy of TLD‐100 in measuring the out‐of‐field photon dose as a function of treatment energy. To determine the accuracy of TLD‐100 as compared with TLD‐700, TLD‐100 was irradiated outside of the treatment field by medical accelerators operated at 6, 10, 15, and 18 MV. In an effort to eliminate the response of TLD‐100 to neutrons, TLD capsules were encased in varying thicknesses of cadmium foil (0.25 – 0.75 mm) before being irradiated at 18 MV. The out‐of‐field TLD‐100 was found to be accurate at 6 MV and 10 MV, but to be substantially over‐responsive at 15 MV and 18 MV (by up to 1063% relative to TLD‐700). By wrapping the TLD‐100 in up to 0.75 mm of cadmium, it was possible to drastically reduce (down to 39% on average) the over‐response of the TLD‐100; however, total removal of the over‐responsiveness was not possible. Although TLD‐100 is well suited for measuring out‐of‐field dose at energies as high as 10 MV, at higher energies (15 MV or greater), this dosimeter over‐responds substantially and should not be used. Although encasing the TLD in cadmium minimized over‐response to a degree, the reduction was not sufficient to make TLD‐100 viable for measuring out‐of‐field dose at high treatment energies. PACS numbers: 87.52.‐g, 87.53.‐j, 87.53.‐Dq

Purpose:Individuals with a spinal-cord injury have impaired thermoregulatory control due to a loss of sudomotor and vasomotor effectors below the lesion level. Thus, individuals with high-level lesions (tetraplegia) possess greater thermoregulatory impairment than individuals with lower-level lesions (paraplegia). Previous research has not reflected the intermittent nature and modality of wheelchair court sports or replicated typical environmental temperatures. Hence, the purpose of this study was to investigate the thermoregulatory responses of athletes with tetraplegia and paraplegia during an intermittent-sprint protocol (ISP) and recovery in cool conditions.Methods:Sixteen wheelchair athletes, 8 with tetraplegia (TP, body mass 65.2 ± 4.4 kg) and 8 with paraplegia (body mass 68.1 ± 12.3 kg), completed a 60-min ISP in 20.6°C ± 0.1°C, 39.6% ± 0.8% relative humidity on a wheelchair ergometer, followed by 15 min of passive recovery. Core temperature (Tcore) and mean (Tsk) and individual skin temperatures were measured throughout.Results:Similar external work (P = .70, ES = 0.20) yet a greater Tcore (P < .05, ES = 2.27) and Tsk (P < .05, ES = 1.50) response was demonstrated by TP during the ISP.Conclusions:Despite similar external work, a marked increase in Tcore in TP during exercise and recovery signifies that thermoregulatory differences between the groups were predominantly due to differences in heat loss. Further increases in thermal strain were not prevented by the active and passive recovery between maximal-effort bouts of the ISP, as Tcore continually increased throughout the protocol in TP.

Ice vest pre-cooling has been show to lower rectal tem- perature during intermittent exercise in hot conditions but only after 40 min of exercise [1]. The authors sug- gested that the ice vest may have initiated a strong local cutaneous vasoconstrictor response reducing skin blood flow [2] and thus the cooling potential, until increases in body temperature and skin blood flow occurred later in exercise. Therefore, the purpose of this study was to determine whether ice vest pre-cooling reduces skin blood flow during intermittent exercise in the heat com- pared to a no cooling control.

Athletes with tetraplegia (spinal cord injury at the cervical region of the spinal cord) are at a greater risk of heat illness than their able-bodied counterparts, due to the loss of sweating capacity and vasomotor control below the lesion level. Commercially available ice vests worn prior to exercise (pre-cooling) have received considerable interest in the able-bodied athletic population eliciting varying results in performance, and physiological and thermoregulatory responses. However, limited research has been conducted in thermoregulatory impaired athletes with tetraplegia. Anecdotally water spraying the face and torso is commonly used by these athletes during breaks in play, though the effectiveness of this method has not been established. The purpose of this study was to investigate the effects of pre-cooling using an ice vest and the combination of pre-cooling and cooling during play using water sprays on simulated wheelchair rugby performance in athletes with tetraplegia.

Cooling strategies that help prevent a reduction in exercise capacity whilst exercising in the heat have received considerable research interest over the past 3 decades, especially in the lead up to a relatively hot Olympic and Paralympic Games. Progressing into the next Olympic/Paralympic cycle, the host, Rio de Janeiro, could again present an environmental challenge for competing athletes. Despite the interest and vast array of research into cooling strategies for the able-bodied athlete, less is known regarding the application of these cooling strategies in the thermoregulatory impaired spinal cord injured (SCI) athletic population. Individuals with a spinal cord injury (SCI) have a reduced afferent input to the thermoregulatory centre and a loss of both sweating capacity and vasomotor control below the level of the spinal cord lesion. The magnitude of this thermoregulatory impairment is proportional to the level of the lesion. For instance, individuals with high-level lesions (tetraplegia) are at a greater risk of heat illness than individuals with lower-level lesions (paraplegia) at a given exercise intensity. Therefore, cooling strategies may be highly beneficial in this population group, even in moderate ambient conditions (~21 °C). This review was undertaken to examine the scientific literature that addresses the application of cooling strategies in individuals with an SCI. Each method is discussed in regards to the practical issues associated with the method and the potential underlying mechanism. For instance, site-specific cooling would be more suitable for an athlete with an SCI than whole body water immersion, due to the practical difficulties of administering this method in this population group. From the studies reviewed, wearing an ice vest during intermittent sprint exercise has been shown to decrease thermal strain and improve performance. These garments have also been shown to be effective during exercise in the able-bodied. Drawing on additional findings from the able-bodied literature, the combination of methods used prior to and during exercise and/or during rest periods/half-time may increase the effectiveness of a strategy. However, due to the paucity of research involving athletes with an SCI, it is difficult to establish an optimal cooling strategy. Future studies are needed to ensure that research outcomes can be translated into meaningful performance enhancements by investigating cooling strategies under the constraints of actual competition. Cooling strategies that meet the demands of intermittent wheelchair sports need to be identified, with particular attention to the logistics of the sport.

STUDY DESIGN Single trial, two factor repeated measures design. SETTING England, Cheshire. OBJECTIVES To examine the thermoregulatory responses of able-bodied (AB) athletes, paraplegic (PA) athletes and a tetraplegic (TP) athlete at rest, during prolonged upper body exercise and recovery. METHODS Exercise was performed on a Monark cycle ergometer (Ergomedic 814E) adapted for arm exercise at 60% VO2 peak for 60 min in cool conditions ('normal' laboratory temperature; 21.5+/-1.7 degrees C and 47+/-7.8% relative humidity). Aural and skin temperatures were continually monitored. RESULTS Mean (+/-S.D.) peak oxygen uptake values were greater (P

Purpose: The smaller muscle mass of the upper body compared to the lower body may elicit a smaller thermoregulatory stimulus during exercise and thus produce novel training induced thermoregulatory adaptations. Therefore, the principal aim of the study was to examine the effect of arm training on thermoregulatory responses during submaximal exercise. Methods: Thirteen healthy male participants (Mean ±SD age 27.8 ±5.0yrs, body mass 74.8 ±9.5kg) took part in 8 weeks of arm crank ergometry training. Thermoregulatory and calf blood flow responses were measured during 30 minutes of arm cranking at 60% peak power (Wpeak) pre, and post training and post training at the same absolute intensity as pre training. Core temperature and skin temperatures were measured, along with heat flow at the calf, thigh, upper arm and chest. Calf blood flow using venous occlusion plethysmography was performed pre and post exercise and calf volume was determined during exercise. Results: The upper body training reduced aural temperature (0.1 ±0.3oC) and heat storage (0.3 ±0.2 J.g-1) at a given power output as a result of increased whole body sweating and heat flow. Arm crank training produced a smaller change in calf volume post training at the same absolute exercise intensity (-1.2 ±0.8% compared to -2.2 ±0.9% pre training; P

The adoption of Total Quality Management has produced many success stories, but discussions of how to adopt TQM often overlook the special needs of small, hightechnology companies. This oversight has led many managers of these companies to conclude that TQM is too cumbersome, bureaucratic, expensive, and complex for them to use. TQM is essential to the long-term viability of small companies but must be adopted in a manner consistent with their special needs. This article discusses these needs and presents specific suggestions about how to successfully adopt TQM in small, high-technology companies.

PRICE, M., P. MOSS, and S. RANCE. Effects of Sodium Bicarbonate Ingestion on Prolonged Intermittent Exercise. Med. Sci. Sports Exerc., Vol. 35, No. 8, pp. 1303–1308, 2003. Purpose: The aim of this study was to determine the effects of sodium bicarbonate ingestion on prolonged intermittent exercise and performance. Methods: Eight healthy male subjects (mean SD: age 25.4 6.4 yr, mass 70.9 5.1 kg, height 179 7 cm, V u O2max 4.21 0.51 L·min 1 ) volunteered for the study, which had received ethical approval. Subjects undertook two 30-min intermittent cycling trials (repeated 3-min blocks; 90 s at 40% V u O2max ,6 0 sa t 60% Vu O2max, 14-s maximal sprint, 16-s rest) after ingestion of either sodium bicarbonate (NaHCO3; 0.3 g·kg 1 ) or sodium chloride (NaCl; 0.045 g·kg 1 ). Expired air, blood lactate (BLa), bicarbonate (HCO3 ), and pH were measured at rest, 30 and 60 min postingestion, and during the 40% V u O2max component of exercise (4, 10, 16, and 29 min). Results: After ingestion, pH increased from rest to 7.46 0.03 and 7.40 0.01 for NaHCO3 and NaCl, respectively (main effect for time and trial; P 0.05). Values decreased at 15 min of exercise to 7.30 0.07 and 7.21 0.06, respectively, remaining at similar levels until the end of exercise. BLa peaked at 15 min (12.03 4.31 and 10.00 2.58 mmol·L 1 , for NaHCO3 and NaCl, respectively; P 0.05) remaining elevated until the end of exercise (P 0.05). Peak power expressed relative to sprint 1 demonstrated a significant main effect between trials ( P 0.05). Sprint 2 increased by 11.5 5% and 1.8 9.5% for NaHCO3 and NaCl, respectively. During NaHCO3, sprint 8 remained similar to sprint 1 (0.2 17%), whereas a decrease was observed during NaCl (10.0 16.0%). Conclusion: The results of this study suggest that ingestion of NaHCO3 improves sprint performance during prolonged intermittent cycling. Key Words: BLOOD LACTATE, PH, ALKALOSIS, PEAK POWER, PERFORMANCE, RPE

This study examined the effects of the level of spinal cord injury upon the thermoregulatory responses of wheelchair athletes during prolonged wheelchair exercise in warm conditions.Eight tetraplegic (TP), 10 high-level paraplegic (HP), and 10 low-level paraplegic (LP) athletes exercised for 60 min at 60% [OV0312]O(2peak) in a warm environment (31.5 +/- 1.7 degrees C, 42.9 +/- 8.0% relative humidity). Skin temperature and aural temperature were monitored.Aural temperature increased gradually during the exercise period by 1.1 +/- 0.3 and 1.4 +/- 0.5 degrees C for the HP and LP groups, with a more marked increase observed for the TP group (2.1 +/- 0.5 degrees C; P0.05). Upper-arm skin temperature was higher for the TP when compared with the HP and LP between 30 and 60 min (P0.05). Back skin temperature was higher for the TP when compared with the HP and LP between 45 and 60 min (P0.05). No differences were noted between groups for the thigh or calf skin temperatures. During recovery, skin temperature remained elevated for the TP group when compared with the HP and LP groups (P0.05). Heat storage was greatest for the TP athletes at the end of exercise and remained elevated throughout recovery (P0.05).All athletes completed the exercise task even though the gradual increase in aural temperature observed for the HP and LP groups suggests a degree of thermal imbalance. However, this was much less than observed for TP athletes, who demonstrated a much greater imbalance in temperature regulation. Increasing the exercise or environmental strain may result in the thermoregulatory responses of athletes with a spinal cord injury being compromised.

INTRODUCTION: Previous research has indicated that carrying a backpack elicits an increase in postural sway during quiet standing (Heller et al. 2009) and stride-to-stride gait variability during walking (Qu and Yeo, 2011). Despite these initial enquires into the effects of carrying external loads on postural stability, little research has examined the effects of anterior load carriage. This gap in the literature is important because many daily (e.g. carrying a laundry basket) and occupational (e.g. courier delivery) activities require loads to be carried in front of the body. Within this context, to further develop the external load-postural stability database we examined the effects of increasing loads carried anteriorly on postural sway and gait parameters in healthy adults. METHODS: Twenty-nine subjects (19 males, 10 females, age = 33.8 ± 12.7 years, height = 1.73 ± 0.07 m, mass = 75.1 ± 13.7 kg) were assessed in four conditions; (1) carrying no load (CON), (2) carrying a load with no added weight (i.e. empty box), (3) carrying a load with 5% body mass, and (4) carrying a load with 10% body mass. Anteroposterior and mediolateral centre of pressure (COP) displacement (cm) and the mean COP velocity (cm·s-1) were used to characterise postural sway. Coefficient of variation of the stride length, stride time and double support time were calculated from 1 min of treadmill walking at a preferred pace for gait assessment. RESULTS: When compared to CON, anteroposterior COP displacement increased with the addition of a 5% (P < 0.001, d = 0.74) and 10% (P < 0.001, d = 1.59) load. The anteroposterior COP displacement also increased from the 5% to the 10% load (P < 0.001, d = 0.75). The addition of the 10% load increased stride time (d = 1.71) and stride length (d = 1.20) variability when compared to CON (P < 0.001). Additionally, stride length variability was significantly greater during 10% compared to 0% (P = 0.004, d = 1.08) and 5% (P = 0.001, d = 1.01) conditions. CONCLUSION: In summary, the increase in postural sway and gait variability with added weight is dependent on the magnitude of the load, where the greater the load, the greater the effect on static and dynamic stability. Changes in the mass-inertia characteristics of the body is one of several mechanisms that have been offered to explain the increased postural sway and gait variability when holding an external load. Given that increased postural sway (Johansson et al. 2017) and gait variability (Verghese et al. 2009) are indicators of increased fall-risk, it can be inferred from the present findings that carrying heavy loads in front of the body increases the likelihood of fall-related incidents.

Intensity variation across Uranus disk during limb darkening-brightening cycles observations to test cloud absence theory, predicting limb brightening in methane bands

Reliable data defining the photometric function of the Saturn ring system at visual (V) wavelengths are interpreted in terms of a simple scattering model. To facilitate the analysis, new photographic photometry of the ring has been carried out utilizing the Lowell observatory plate collection. Homogeneous measurements of the mean surface brightness (rings A and B together), covering almost the complete range in planetocentric solar declination angle, are presented. The ring model adopted is a plane-parallel slab of isotropically scattering particles; the single scattering albedo and the perpendicular optical thickness are both arbitrary. Results indicate that primary scattering is inadequate to describe the photometric properties of the ring; multiple scattering predominates for all angles of tilt with respect to the Sun and Earth.