Trivial Differences Research Articles

The validity and reliability of a novel app for the measurement of change of direction performance

ABSTRACT The aim of the present investigation was to analyze the validity and reliability of a novel iPhone app (CODTimer) for the measurement of total time and interlimb asymmetry in the 5 + 5 change of direction test (COD). To do so, twenty physically active adolescent athletes (age = 13.85 ± 1.34 years) performed six repetitions in the COD test while being measured with a pair of timing gates and CODTimer. A total of 120 COD times measured both with the timing gates and the app were then compared for validity and reliability purposes. There was an almost perfect correlation between the timing gates and the CODTimer app for the measurement of total time (r = 0.964; 95% Confidence interval (CI) = 0.95–1.00; Standard error of the estimate = 0.03 s.; p < 0.001). Moreover, non-significant, trivial differences were observed between devices for the measurement of total time and interlimb asymmetry (Effect size < 0.2, p > 0.05). Similar levels of reliability were observed between the timing gates and the app for the measurement of the 6 different trials of each participant (Timing gates: Intraclass correlation coefficient (ICC) = 0.651–0.747, Coefficient of variation (CV) = 2.6–3.5%; CODTimer: ICC = 0.671–0.840, CV = 2.2–3.2%). The results of the present study show that change of direction performance can be measured in a valid, reliable way using a novel iPhone app.

Measurement Invariance Across Age Groups and Over 20 Years’ Time of the Negative and Positive Affect Scale (NAPAS)

Abstract. The factor structure and measurement invariance across gender of Mroczek’s and Kolarz’s scales of positive affect (PA) and negative affect (NA) have been examined in past studies; however, little is known about the measurement invariance across age groups and over time, which are important psychometric properties for developmental research. The current study sought to fill this gap using the data from the National Survey of Midlife Development in the United States (MIDUS). Multi-group confirmatory factor analysis (CFA) was used to examine increasing levels of measurement invariance across gender and age groups. Longitudinal CFA was also used to test measurement invariance over three time points using the data from MIDUS 1 ( N = 3,748), MIDUS 2 ( N = 2,257), and MIDUS 3 ( N = 1,414). Results supported full scalar invariance across gender, age groups, and over time. The latent means for NA were significantly different between men and women at time 1 and 2, but not at time 3; the latent means for both PA and NA were also different across age groups. There were no significant differences for PA and only trivial differences for NA over time within individuals. Implications of these results for longitudinal research are discussed.

Spinal Manipulative Therapy Effects in Autonomic Regulation and Exercise Performance in Recreational Healthy Athletes: A Randomized Controlled Trial.

A randomized, double blind, parallel groups, sham-controlled trial. The aim of this study was to analyze the acute effects of spinal manipulative therapy (SMT) on performance and autonomic modulation. The use of SMT is progressively spreading from the clinical to the sporting context owing to its purported ergogenic effects. However, its effects remain unclear. Thirty-seven male recreational athletes (aged 37 ± 9 years) who had never received SMT were assigned to a sham (n = 19) or actual SMT group (n = 18). Study endpoints included autonomic modulation (heart rate variability), handgrip strength, jumping ability, and cycling performance [8-minute time trial (TT)]. Differences in custom effects between interventions were determined using magnitude-based inferences. A significant and very likely lower value of a marker of sympathetic modulation, the stress score, was observed in response to actual compared with sham SMT [P = 0.007; effect size (ES) = -0.97]. A trend toward a significant and likely lower sympathetic:parasympathetic ratio (P = 0.055; ES = -0.96) and a likely higher natural logarithm of the root-mean-square differences of successive heartbeat intervals [(LnRMSSD), P = 0.12; ES = 0.36] was also found with actual SMT. Moreover, a significantly lower mean power output was observed during the TT with actual compared with sham SMT (P = 0.035; ES = -0.28). Nonsignificant (P > 0.05) and unclear or likely trivial differences (ES < 0.2) were found for the rest of endpoints, including handgrip strength, heart rate during the TT, and jump loss thereafter. A single pre-exercise SMT session induced an acute shift toward parasympathetic dominance and slightly impaired performance in recreational healthy athletes. 2.

Application and interpretation of the yo-yo intermittent recovery test to the long-term physical development of girls association football players

ABSTRACTWe aimed to evaluate short- and long-term yo-yo intermittent recovery test, level 1 (YYIRL1) performance in girls football players. Mixed-linear modelling was used to determine within-season changes in YYIRL1 performance and between- and within-player variation over four years, at four time points (July, September, December and May) in 86 players (459 observations), mean age 13 ± standard deviation 1.8 years, 0.9 ± 1.5 years from peak height velocity. Twenty-three players, tested over three consecutive years were retained for further analysis. Magnitude-based inferences were used to quantify annual change in performance on a group and individual level. Within-player correlations were used to determine the association between YYIRL1 and maturation. ‘Very likely’ small (14, ±90% confidence interval 8.1–20%) improvements were observed between July and September and ‘possibly’ trivial (5.5, 0.41–11%) differences between September and May. Within-player variation throughout the in-season period, representing the typical error of the estimate was 23%, 22–25% and between-player, 38, 33–44%. We observed ‘most likely’ moderate improvements (32, 17–49%) over three years that were moderately associated with changes in maturation (r = 0.46, 0.13 to 0.70). A minimum change of ≥44% is required to detect ‘likely’ improvements in YYIRL1 performance on an individual basis.

Effects of Small-Sided Games vs. Conventional Endurance Training on Endurance Performance in Male Youth Soccer Players: A Meta-Analytical Comparison

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. 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. The data sources utilised were Google Scholar, PubMed and Microsoft Academic. Studies were eligible for inclusion if interventions were carried out in male soccer players (aged < 18years) and compared the effects of small-sided games and conventional endurance training on aerobic endurance performance. We defined small-sided games as "modified [soccer] games played on reduced pitch areas, often using adapted rules and involving a smaller number of players than traditional games". We defined conventional endurance training as continuous running or extensive interval training consisting of work durations > 3min. 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. 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 < 4min) and recovery period between sets (≥ or < 3min). Programmes that were longer than 8weeks 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)]. 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 4min of activity, interspersed with recovery periods of 3min, recommended in this population.

Evaluation of Submillimeter Diffusion Imaging of the Macaque Brain Using Readout-Segmented EPI at 7T.

The purpose of the present study was to achieve submillimeter-level diffusion tensor imaging (DTI) of the macaque brain by using diffusion weighted (DW) readout-segmented echo planar imaging (rsEPI) with an optimized protocol at 7T MRI. Three anesthetized macaques were included in this study. Under different scan settings, we compared the signal-to-noise ratio (SNR) and geometric distortion of DW images, implemented an optimized protocol for submillimeter-level DTI acquisition, and evaluated its performance. The parallel-imaging-enabled (in GRAPPA mode) monopolar or monopolar+ diffusion scheme has higher SNR versus bipolar scheme, whereas trivial differences in SNR and image geometric distortion occurred when using increased readout segments with monopolar and monopolar+ that did not reach statistical significance. Submillimeter-level (0.8 mm isotropic) DTI data provide a sharper delineation of white matter contour than the 1 mm level. The rsEPI technique with parallel imaging enabled, and with the shortest readout segments in conjunction with monopolar/monopolar+ diffusion encoding scheme, may be optimal for submillimeter-level diffusion imaging over macaque brains in vivo. rsEPI could effectively merit high-resolution DTI for in vivo macaque brain submillimeter structural architecture investigations at ultrahigh fields.

Effects of Intracyclic Velocity Variations on the Drag Exerted by Different Swimming Parachutes.

Cortesi, M, Di Michele, R, and Gatta, G. Effects of intracyclic velocity variations on the drag exerted by different swimming parachutes. J Strength Cond Res 33(2): 531-537, 2019-Swimming parachutes are often used as a tool for resisted swimming training. However, little is known on their behavior in terms of exerted drag as a consequence of intracyclic velocity fluctuations. This study aimed to assess the drag provided by 2 swimming parachutes of different shape, also characterized by different volumes and cross-sectional areas, under conditions of velocity variations in the range of those occurring in swimming. A flat square-shaped parachute (FLAT, cross-sectional area and volume: 400 cm; 0.12 L) and a truncated cone-shaped parachute (CONE, 380 cm; 7.15 L) were passively towed: (a) at constant velocities ranging from 1.0 to 2.2 m·s, and (b) with velocity fluctuations from 10 to 40% around a mean of 1.6 m·s. At constant velocities, FLAT showed 0.1 N (at 1.0 m·s) to 10.8 N (at 2.2 m·s) higher drag than CONE. For both parachutes, the average drag showed trivial differences between constant and any fluctuating velocity. Conversely, the maximum drag values were higher under conditions of velocity fluctuations than the respective values estimated under stationary instantaneous velocity, although this was observed in CONE only. These findings suggest that swimmers and coaches can select the parachute characteristics based on whether the focus is on increasing/decreasing the average drag or regulating the maximum resistance provided.

High tempo music prolongs high intensity exercise.

Music has been shown to reduce rating of perceived exertion, increase exercise enjoyment and enhance exercise performance, mainly in low-moderate intensity exercises. However, the effects of music are less conclusive with high-intensity activities. The purpose of this with-participant design study was to compare the effects of high tempo music (130 bpm) to a no-music condition during repeated high intensity cycling bouts (80% of peak power output (PPO)) on the following measures: time to exercise end-point, rating of perceived exertion (RPE), heart rate (HR), breathing frequency, ventilatory kinetics and blood lactate (BL). Under the music condition, participants exercised 10.7% longer (p = 0.035; Effect size (ES) = 0.28) (increase of 1 min) and had higher HR (4%; p = 0.043; ES = 0.25), breathing frequency (11.6%; p < 0.001; ES = 0.57), and RER (7% at TTF; p = 0.021; ES = 1.1) during exercise, as measured at the exercise end-point. Trivial differences were observed between conditions in RPE and other ventilatory kinetics during exercise. Interestingly, 5 min post-exercise termination, HR recovery was 13.0% faster following the music condition (p < 0.05) despite that music was not played during this period. These results strengthen the notion that music can alter the association between central motor drive, central cardiovascular command and perceived exertion, and contribute to prolonged exercise durations at higher intensities along with a quicken HR recovery.

Relationships Between Model-Predicted and Actual Match-Play Exercise-Intensity Performance in Professional Australian Footballers During a Preseason Training Macrocycle.

To assess and compare the validity of internal and external Australian football (AF) training-load measures for predicting preseason variation of match-play exercise intensity (MEI sim/min) using a variable dose-response model. A total of 21 professional male AF players completed an 18-wk preseason macrocycle. Preseason internal training load was quntified using the session rating-of-perceived-exertion method (sRPE) and external load from satellite (as distance [Dist] and high-speed distance [HS Dist]) and accelerometer (Player Load [PL]) data. Using a training-impulse (TRIMPs) calculation, external load expressed in arbitrary units was represented as TRIMPsDist, TRIMPsHSDist, and TRIMPsPL. Preseason training load and MEI sim/min data were applied to a variable dose-response model, which provided estimates of MEI sim/min. Model estimates of MEI sim/min were correlated with actual measures from each match-play drill performed during the preseason macrocycle. Magnitude-based inferences (effect size [90% confidence interval]) were calculated to determine practical differences in the precision of MEI sim/min estimates using each of the internal- and external-load inputs. Estimates of MEI sim/min demonstrated very large and large associations with actual MEI sim/min with models constructed from external and internal training inputs (r [90% confidence interval]; TRIMPsDist .73 [.72-.74], TRIMPsPL .72 [.71-.73], and sRPESkills .67 [.56-.78]). There were trivial differences in the precision of MEI sim/min estimates between models constructed from TRIMPsDist and TRIMPsPL and between internal input methods. Variable dose-response models from multiple training-load inputs can predict the within-individual variation of MEI sim/min across an entire preseason macrocycle. Models informed by external training inputs (TRIMPsDist and TRIMPsPL) exhibited predictive power comparable to those of sRPESkills models.

Noise and Silence in Rwanda’s Postgenocide Religious Soundscape

AbstractThis article explores conflicts around noise and silence in Rwanda’s postgenocide religious soundscape. After the genocide, new Pentecostal (or abarokore) churches grew rapidly in the country and offered up noise and a specific understanding of praise and worship music (guhimbaza Imana) as important ways to enact healing. However, Catholics emphasised silence and viewed the new Pentecostal churches as distracting interlopers. Far from being trivial differences, I argue that these conflicts around sound hint at wider divides in Rwandan society and a worrying new convergence between religious and ethnic identity. Focusing on aural conflicts between Christian denominations can therefore help us gain a better sense of the limits of Pentecostal conversion. Instead of assuming that Pentecostals are necessarily ‘noisy’, I suggest we pay closer attention to the ways in which they may also cultivate silence, and how this relates to wider power structures.

Force-velocity profiling of sprinting athletes: single-run vs. multiple-run methods.

This study explored the agreement between a single-run and a multiple-run method for force-velocity (Fv) profiling of sprinting athletes; we evaluated both absolute values and changes over time caused by sprint training. Seventeen female handball players (23 ± 3years, 177 ± 7cm, 73 ± 6kg) performed 30m un-resisted and resisted sprints (50, 80 and 110N resistance) before and after an 8-week sprint training intervention. Two approaches were used to calculate theoretical maximal velocity (v0), horizontal force (F0), power (Pmax), and the force-velocity slope (SFv): (1) the single-run method, based on inverse dynamics applied to the centre-of-mass movement, was calculated from anthropometric and sprint split time data; and (2) the multiple-run method, where peak velocity from un-resisted and resisted sprints were plotted against the horizontal resistances. Trivial differences in v0 (0.7%) were observed between the two calculation methods. Corresponding differences for F0, Pmax and SFv were 16.4, 15.6 and 17.6%, respectively (most likely; very large effect size). F0 showed poor agreement between the methods (r = 0.26 and 0.16 before and after the intervention). No substantial correlation between the changes (from pre- to post-training tests) in SFV calculated with the single-run and the multiple-run methods were observed (r = 0.03) [corrected]. This study revealed poor agreement between the Fv relationships of the investigated calculation methods. In practice, both methods may have a purpose, but the single-run and the multiple-run methods appear to measure somewhat different sprint properties and cannot be used interchangeably.

Different structures of berberine and five other protoberberine alkaloids that affect P-glycoprotein-mediated efflux capacity.

Berberine, berberrubine, thalifendine, demethyleneberberine, jatrorrhizine, and columbamine are six natural protoberberine alkaloid (PA) compounds that display extensive pharmacological properties and share the same protoberberine molecular skeleton with only slight substitution differences. The oral delivery of most PAs is hindered by their poor bioavailability, which is largely caused by P-glycoprotein (P-gp)-mediated drug efflux. Meanwhile, P-gp undergoes large-scale conformational changes (from an inward-facing to an outward-facing state) when transporting substrates, and these changes might strongly affect the P-gp-binding specificity. To confirm whether these six compounds are substrates of P-gp, to investigate the differences in efflux capacity caused by their trivial structural differences and to reveal the key to increasing their binding affinity to P-gp, we conducted a series of in vivo, in vitro, and in silico assays. Here, we first confirmed that all six compounds were substrates of P-gp by comparing the drug concentrations in wild-type and P-gp-knockout mice in vivo. The efflux capacity (net efflux) ranked as berberrubine > berberine > columbamine ~ jatrorrhizine > thalifendine > demethyleneberberine based on in vitro transport studies in Caco-2 monolayers. Using molecular dynamics simulation and molecular docking techniques, we determined the transport pathways of the six compounds and their binding affinities to P-gp. The results suggested that at the early binding stage, different hydrophobic and electrostatic interactions collectively differentiate the binding affinities of the compounds to P-gp, whereas electrostatic interactions are the main determinant at the late release stage. In addition to hydrophobic interactions, hydrogen bonds play an important role in discriminating the binding affinities.

Chaos and variance in galaxy formation

The evolution of galaxies is governed by equations with chaotic solutions: gravity and compressible hydrodynamics. While this micro-scale chaos and stochasticity has been well studied, it is poorly understood how it couples to macro-scale properties examined in simulations of galaxy formation. In this paper, we show how perturbations introduced by floating-point roundoff, random number generators, and seemingly trivial differences in algorithmic behaviour can produce non-trivial differences in star formation histories, circumgalactic medium (CGM) properties, and the distribution of stellar mass. We examine the importance of stochasticity due to discreteness noise, variations in merger timings and how self-regulation moderates the effects of this stochasticity. We show that chaotic variations in stellar mass can grow until halted by feedback-driven self-regulation or gas exhaustion. We also find that galaxy mergers are critical points from which large (as much as a factor of 2) variations in quantities such as the galaxy stellar mass can grow. These variations can grow and persist for more than a Gyr before regressing towards the mean. These results show that detailed comparisons of simulations require serious consideration of the magnitude of effects compared to run-to-run chaotic variation, and may significantly complicate interpreting the impact of different physical models. Understanding the results of simulations requires us to understand that the process of simulation is not a mapping of an infinitesimal point in configuration space to another, final infinitesimal point. Instead, simulations map a point in a space of possible initial conditions points to a volume of possible final states.

The impact of chronic carbohydrate manipulation on mucosal immunity in elite endurance athletes

ABSTRACTCarbohydrate (CHO) availability could alter mucosal immune responses to exercise. This study compared the effect of three dietary approaches to CHO availability on resting and post-exercise s-IgA levels. Elite race walkers (n = 26) adhered to a high CHO diet (HCHO), periodised CHO availability (PCHO) or a low CHO/high fat diet (LCHF) for 3 weeks while completing an intensified training program. HCHO and PCHO groups consumed 8.0–8.5 g.kg−1 CHO daily, with timing of ingestion manipulated to alter CHO availability around key training sessions. The LCHF diet comprised 80% fat and restricted CHO to < 50 g.day−1. A race walk test protocol (19 km females, 25 km males) was completed at baseline, after adaptation, and following CHO restoration. On each occasion, saliva samples were obtained pre- and post-exercise to quantify s-IgA levels. Resting s-IgA secretion rate substantially increased ~ two-fold post-intervention in all groups (HCHO: 2.2 ± 2.2, PCHO: 2.8 ± 3.2, LCHF: 1.6 ± 1.6; fold-change± 95% confidence limits), however, no substantial differences between dietary treatments were evident. Post-exercise, substantial 20–130% increases in s-IgA concentration and 43–64% reductions in flow rate occurred in all dietary treatments, with trivial differences evident between groups. It appears that high volume training overrides any effect of manipulating CHO availability on mucosal immunity in elite athletes.

Average of trial peaks versus peak of average profile: impact on change of direction biomechanics

ABSTRACT The aims of this study were twofold: firstly, to compare lower limb kinematic and kinetic variables during a sprint and 90° cutting task between two averaging methods of obtaining discrete data (peak of average profile vs. average of individual trial peaks); secondly, to determine the effect of averaging methods on participant ranking of each variable within a group. Twenty-two participants, from multiple sports, performed a 90° cut, whereby lower limb kinematics and kinetics were assessed via 3D motion and ground reaction force (GRF) analysis. Six of the eight dependent variables (vertical and horizontal GRF; hip flexor, knee flexor, and knee abduction moments, and knee abduction angle) were significantly greater (p ≤ 0.001, g = 0.10–0.37, 2.74–10.40%) when expressed as an average of trial peaks compared to peak of average profiles. Trivial (g ≤ 0.04) and minimal differences (≤ 0.94%) were observed in peak hip and knee flexion angle between averaging methods. Very strong correlations (ρ ≥ 0.901, p < 0.001) were observed for rankings of participants between averaging methods for all variables. Practitioners and researchers should obtain discrete data based on the average of trial peaks because it is not influenced by misalignments and variations in trial peak locations, in contrast to the peak from average profile.

The peak duration-specific locomotor demands and concurrent collision frequencies of European Super League rugby

ABSTRACTUnderstanding the most demanding passages of European Super League competition can optimise training prescription. We established positional and match half differences in peak relative distances (m·min−1) across durations, and the number of collisions, high-speed- and very-high-speed-distance completed in the peak 10 min period. Moving-averages (10 s, 30 s, 1 min, 5 min, 10 min) of instantaneous speed (m·s−1) were calculated from 25 professional rugby league players during 25 matches via microtechnology. Maximal m·min−1 was taken for each duration for each half. Concurrently, collisions (n), high-speed- (5 to 7 m·s−1; m) and very-high-speed-distance (> 7 m·s−1; m) were coded during each peak 10 min. Mixed-effects models determined differences between positions and halves. Aside from peak 10 s, trivial differences were observed in peak m·min−1 between positions or halves across durations. During peak 10 min periods, adjustables, full- and outside-backs ran more at high-speed and very-high-speed whilst middle- and edge-forwards completed more collisions. Peak m·min−1 is similar between positional groups across a range of durations and are maintained between halves of the match. Practitioners should consider that whilst the overall peak locomotor “intensity” is similar, how they achieve this differs between positions with forwards also exposed to additional collision bouts.

Statistically significant survival benefits in randomized clinical trials in oncology: are they potentially clinically relevant?

We aimed at studying how often “statistically significant” improvements in survival in oncological randomized clinical trials (RCTs) are compatible with trivial (clinically non-significant) differences. We selected meta-analyses on the impact of oncology treatments that included phase 3 RCTs with overall survival as primary or secondary outcome. Our source was the Cochrane Review database. We only selected meta-analyses that included studies with point estimate and confidence interval that indicated a statistically significant benefit for overall survival. For each of the selected meta-analysis, we then recorded the individual studies point estimate and confidence interval when they were statistically significant. The point estimate and the upper confidence limit were categorized to determine what proportion of significant point estimates were compatible with trivial differences according to the upper confidence limit (close to 1). Categories were < 0.5, 0.5–0.59, 0.6–0.69, 0.7–0.79, 0.8–0.89, and 0.9–0.99. A total of 109 point estimates corresponding to hazard ratios were extracted. The 109 point estimates were distributed as follows: 0 above 0.9, 11 (10%) between 0.8 and 0.89, 26 between 0.7 and 0.79 (24%), 37 between 0.6 and 0.69 (34%), 14 between 0.5 and 0.59 (13%) and 21 below 0.5 (19%). More than 2 out of 3 studies (72/109, 66%) had a point estimate below 0.7 indicating a gain in overall survival and clinically significant efficacy of the treatment. In contrast, the upper limits of the confidence intervals were frequently compatible with clinically trivial benefits. For 41 studies (38%), this upper limit was ≥ 0.95, for 25 (23%) studies it was between 0.90 and 0.94, for 28 (26%) it was between 0.80 and 0.89 and for only 15 (14%) it was below 0.80. Such contrast was most compelling for studies with a main point estimate between 0.6 and 0.69 for which 22 out of 37 (59%) had an upper confidence limit of 0.9 or above. The survival benefits described in “statistically significant” phase 3 oncology trials were often clinically impressive, as relative reductions in mortality exceeded 30% in two thirds of the studies. However upper confidence limits of these estimates were frequently in the vicinity of 1, and were compatible with a clinically negligible benefit: for 61% of the trials the upper limit suggested a relative reduction in mortality below 10%. Clinicians should consider not only if a treatment benefit is statistically significant and if the point estimate is sufficiently clinically convincing, but should also consider the uncertainty of the benefit, reflected by the width of the confidence interval, and in particular the confidence bound nearest the null hypothesis of no benefit. Trialists should design trials with a sufficient power not only to detect a given survival benefit, but also to exclude small survival benefits of little clinical relevance.

Immigrants’ Experiences of Everyday Discrimination in Canada: Unpacking the Contributions of Assimilation, Race, and Early Socialization

We examined perceptions of everyday discrimination among immigrants in Canada and in comparison to native-born Canadians using data from the 2013 Canadian Community Health Survey. We find that recent immigrants report less discrimination than native-born Canadians, ceteris paribus. Recent immigrants also report less discrimination than their fellow immigrants who had been residing in Canada for much longer durations. There were trivial differences in perceptions of everyday discrimination between native-born Canadians and midway and established immigrants, all else being equal. Additional analysis suggests that differences in age at arrival and associated early socialization experiences might explain variations in immigrants’ perceived discrimination.

Upper and lower body responses to repeated cyclical sprints

Purpose: To compare the physiological and perceptual responses of the upper and lower body to all-out cyclical sprints with short or long rest periods between sprints.Methods: Ten recreationally trained males completed four 10 × 10 s sprint protocols in a randomized order: upper body with 30 s and 180 s of rest between sprints, and lower body with 30 s and 180 s of rest between sprints. Additionally, maximum voluntary contractions (MVC) were measured at pre-sprint and post-sprints 5 and 10. Normalized (% of first sprint) peak power, MVC, heart rate (HR) and rating of perceived exertion (RPE) were compared between upper and lower body within the same recovery period, and absolute values (Watts, bpm, RPE scores) were compared within the same body part and between recovery periods.Results: Trivial differences were identified in normalized peak power, HR and RPE values between the upper and lower body in both recovery conditions (<2%, d ≤ 0.1), but MVC forces were better maintained with the upper body (∼9.5%, d = 1.0) in both recovery conditions. Absolute peak power was lower (∼147 Watts, d = 1.3), and HR was higher (∼10 bpm, d = 0.73) in the 30 s compared to 180 s condition in both the upper and lower body whereas RPE scores were similar (<0.6 RPE units, d ≤ 0.1). Despite the reductions in peak power, MVC forces were better maintained in the 30 s condition in both upper (2.5 kg, d = 0.4) and lower (7.5 kg, d = 0.7) body.Conclusions: Completing a commonly used repeated sprint protocol with the upper and lower body results in comparable normalized physiological and perceptual responses.

Effect of Low-Pass Filtering on Isometric Midthigh Pull Kinetics.

Dos'Santos, T, Lake, J, Jones, PA, and Comfort, P. Effect of low-pass filtering on isometric midthigh pull kinetics. J Strength Cond Res 32(4): 983-989, 2018-The purpose of this study was to investigate the effect of low-pass filtering on isometric midthigh pull (IMTP) kinetics, including body weight (BW), onset threshold force, time-specific force values (50, 100, 150, and 200 ms), and peak force (PF). Forty IMTP trials from 24 collegiate athletes (age: 21.2 ± 1.8 years, height: 1.72 ± 0.09 m, mass: 79.4 ± 8.2 kg) were analyzed and compared using unfiltered (UF) and low-pass filtered (LPF) (fourth-order Butterworth) with cutoff frequencies of 10 (LPF10) and 100 (LPF100) Hz. Significantly lower (p < 0.001, g = -0.43 to -0.99) onset threshold forces were produced when force data were LPF. This led to significant (p < 0.001, g = 0.05-0.21) underestimations of time-specific force values when LPF10 compared with UF, displaying unacceptable percentage differences (1.2-3.3%) and unacceptable limits of agreement (LOA) (-25.4 to 100.3 N). Although significantly different (p ≤ 0.049), trivial (g ≤ 0.04) and acceptable percentage differences (≤0.8%) and acceptable LOA (-28.0 to 46.2 N) in time-specific force values were observed between UF and LPF100. Statistically significant (p < 0.001), yet trivial (g ≤ 0.03), and acceptable percentage differences (≤0.7%) and acceptable LOA (-4.7 to 33.9 N) were demonstrated in PF between filtering conditions. No significant differences (p = 1.000) and identical BW values were observed between filtering conditions. Low-pass filtering results in underestimations in IMTP kinetics; however, these differences are acceptable between LPF100 and UF but unacceptable between LPF10 and UF (excluding PF). Filtering procedures should be standardized when longitudinally monitoring changes in IMTP force-time characteristics to allow valid comparisons, with analysis of UF data recommended.