The test-retest reliability of physiological and perceptual responses during treadmill load carriage.

PURPOSE: Understanding the test-retest reliability of physiological responses to load carriage influences the interpretation of those results. The aim of this study was to determine the test-retest reliability of physiological measures during loaded treadmill walking at 5.5 km h-1 using the MetaMax 3B. METHODS: Fifteen Australian Army soldiers (9 male, 6 female) repeated two 12-min bouts of treadmill walking at 5.5 km h-1 in both a 7.2 kg Control condition (MetaMax 3B, replica rifle) and a 23.2 kg Patrol condition (Control condition plus vest) across three sessions, separated by one week. Expired respiratory gases and heart rate were continuously collected, with the final 3 min of data analysed. Ratings of Perceived Exertion and Omnibus-Resistance Exercise Scale were taken following each trial. Reliability was quantified by coefficient of variation (CV), intra-class correlation coefficients (ICC), smallest worthwhile change (SWC), and standard error of the measurement. RESULTS: Metabolic and cardiovascular variables were highly reliable (≤ 5% CV; excellent-moderate ICC), while the respiratory variables demonstrated moderate reliability (< 8% CV; good-moderate ICC) across both conditions. Perceptual ratings had poorer reliability during the Control condition (12-45% CV; poor ICC) than the Patrol condition (7-16% CV; good ICC). CONCLUSIONS: The test-retest reliability of metabolic and cardiovascular variables was high and relatively consistent during load carriage. Respiratory responses demonstrated moderate test-retest reliability; however, as the SWC differed with load carriage tasks, such data should be interpreted independently across loads. Perceptual measures demonstrated poor to moderate reliability during load carriage, and it is recommended that they only be employed as secondary measures.

One genome, multiple phenotypes: decoding the evolution and mechanisms of environmentally induced developmental plasticity in insects.

Plasticity in developmental processes gives rise to remarkable environmentally induced phenotypes. Some of the most striking and well-studied examples of developmental plasticity are seen in insects. For example, beetle horn size responds to nutritional state, butterfly eyespots are enlarged in response to temperature and humidity, and environmental cues also give rise to the queen and worker castes of eusocial insects. These phenotypes arise from essentially identical genomes in response to an environmental cue during development. Developmental plasticity is taxonomically widespread, affects individual fitness, and may act as a rapid-response mechanism allowing individuals to adapt to changing environments. Despite the importance and prevalence of developmental plasticity, there remains scant mechanistic understanding of how it works or evolves. In this review, we use key examples to discuss what is known about developmental plasticity in insects and identify fundamental gaps in the current knowledge. We highlight the importance of working towards a fully integrated understanding of developmental plasticity in a diverse range of species. Furthermore, we advocate for the use of comparative studies in an evo-devo framework to address how developmental plasticity works and how it evolves.

Number of trials necessary to achieve a representative performance of accuracy and timing during combat shooting.

Acquisition evaluations are expensive, have a high time liability, and tend to prioritize engineering requirements over human factors and good experimental design. Shooting serials usually consist of static prone shooting to minimize movement variability, increase reliability of accuracy and timing data or use a single data point to make acquisition decisions. To better understand the number of trials required to achieve representative performance of accuracy and timing, 60 shots from the standing unsupported position while cyclically moving the weapon from the low ready to shoot was utilized. Intra-class correlations, standard error of measurement, minimal detectable change, and sequential averaging analysis (SAA) were used to evaluate the variables of radial error, shot interval, x-bias and y-bias over the 60 shots. The number of trials required to achieve an intraclass correlation of greater than 0.8 ranged from 2 (shot interval) to 58 (y-bias), whereas SAA varied between 3 (x-bias) and 43 (shot interval) trials. When averaging 10 shots at a time, the moving intraclass correlation remained above 0.8 for radial error and y-bias between 7 and 15 shots, shot interval from the second shot, but x-bias never reached 0.8. The number of trials required to satisfy each reliability method was inconsistent, in line with previous literature. Given the limitations identified in the literature as well as practical considerations such as the preference for prioritizing radial error reasonable performance stability can be achieved after 15 shots, and using the moving intraclass correlation results it is recommended that the first six shots are discarded with the following nine shots used for analysis.

The use of physically constraining tools for grip-specific skill development in racket, stick and club sports: A scoping review.

Coaches use physically constraining tools to supplement their coaching when developing sport-specific skills, however, their effectiveness is unknown. This scoping review aimed to understand the efficacy of physically constraining tools used in racket, stick, and club sports for grip-specific skill development. This scoping review followed the Joanna Briggs Institute methodology and PRISMA guidelines. Peer-reviewed research, including quasi-experimental, true-experimental, case studies, and grey literature were considered. Peer-reviewed sources were searched on Web of Science, Medline, and SPORTDiscus until October 6th, 2022. Exclusion criteria were (1) not original peer-reviewed research; (2) disabled participants or used for rehabilitation; or (3) not available in English. Data extracted were the type of tool, research foci, measures, and outcomes of the tool's efficacy. Zero peer-reviewed sources were identified on the efficacy of using physically constraining tools for grip-specific skill development. Common trends identified from the excluded sources were explored to provide a basis for the importance of using physically constraining tools for grip-specific skill development. Many tools are used in coaching despite their unclear efficacy, however, the current results can guide future work to assess the acute and longitudinal effects of using these tools, specifically within the development and performance of sport-specific skills.

Association Between Position-Specific Impact and Movement Characteristics of Professional Rugby Union Players During Game Play.

ABSTRACT: Peek, RJ, Carey, DL, Middleton, KJ, Gastin, PB, and Clarke, AC. Association between position-specific impact and movement characteristics of professional rugby union players during game play. J Strength Cond Res 37(1): 161-166, 2023-The aim of this study was to understand the association between impact and movement characteristics during whole game and peak 1- to 10-minute rolling windows in professional rugby union. Maximal impact (impacts·min-1) and corresponding running (m·min-1) characteristics as well as maximal running (m·min-1) and corresponding impact (impacts·min-1) characteristics were obtained for 160 athletes from 4 teams across the 2018 and 2019 Super Rugby seasons. A linear mixed-effects model reported a positive association between whole-game running and impacts, where greater impact characteristics corresponded with greater running characteristics. The average 1-minute peak running characteristics (150-160 m·min-1) typically occurred when no impacts occurred. The average 1-minute peak impact characteristics (4-6 impacts·min-1) corresponded with an average relative distance of 90-100 m·min-1. Worst case scenario observed impact characteristics as large as 15 impacts·min-1 with a corresponding relative distance of 140 m·min-1. When training for peak period characteristics, running may be completed in isolation; however, peak impacts often occur in conjunction with moderate to high running movements. Given running and impact characteristics can appear concurrently within game play, this highlights the need to train them accordingly. As such, when prescribing training drills to replicate the peak characteristics in rugby union, consideration should be taken for both running and impact characteristics.

Positional and temporal differences in peak match running demands of elite football.

Temporal changes in the total running demands of professional football competition have been well documented, with absolute running demands decreasing in the second half. However, it is unclear whether the peak match running demands demonstrate a similar decline. A total of 508 GPS files were collected from 44 players, across 68 matches of the Australian A-League. GPS files were split into the 1st and 2nd half, with the peak running demands of each half quantified across 10 moving average durations (1-10 min) for three measures of running performance (total distance, high-speed distance [> 19.8 km · h-1] and average acceleration). Players were categorised based on positional groups: attacking midfielder (AM), central defender (CD), defensive midfielder (DM), striker (STR), wide defender (WD) and winger (WNG). Linear mixed models and effect sizes were used to identify differences between positional groups and halves. Peak running demands were lower in the second half for STR across all three reported metrics (ES = 0.60-0.84), with peak average acceleration lower in the second half for DM, WD and WNG (ES = 0.60-0.70). Irrespective of match half, AM covered greater peak total distances than CD, STR, WD and WIN (ES = 0.60-2.08). Peak high-speed distances were greater across both halves for WIN than CD, DM and STR (ES = 0.78-1.61). Finally, STR had lower peak average acceleration than all positional groups across both halves (ES = 0.60-1.12). These results may help evaluate implemented strategies that attempt to mitigate reductions in second half running performance and inform position specific training practices.

Differences in accuracy and consistency in elite lawn bowlers.

The aim of this study was to determine whether there are differences in the accuracy and consistency of repeated lawn bowl deliveries between different bowling conditions and to describe the bias of bowls that missed the target (jack). Twenty-seven elite lawn bowl athletes were recruited to partake in the study. Participants delivered 16 bowls in four conditions: (i) forehand and (ii) backhand towards a target 23 metres away and (iii) forehand and (iv) backhand towards a target 27 metres away. The resting position of each bowl relative to the jack was described in terms of absolute displacement, width displacement and length displacement. For each participant and each condition, the average absolute displacement of deliveries was calculated as a measure of accuracy; the average width and length displacement was used to describe the bias of deliveries; and the bivariate variable error of absolute displacement was calculated as a measure of consistency. The forehand towards a target 23 metres away was significantly less accurate and consistent when compared with other conditions. There was a bias for greater width displacement of both forehand deliveries (p < 0.001). Analysing lawn bowls in this detail provides specific areas for coaching to improve lawn bowling performance.

Objective assessment of fast bowling delivery intensity in amateur male cricketers.

Wearable microtechnology is effective in detecting fast deliveries in cricket, however methods to quantify delivery intensity have not been established. This study aimed to investigate the utility of wearable sensors in quantifying cricket fast bowling intensity.Fifteen sub-elite male fast bowlers performed deliveries at warm-up, match, and maximal intensities. A principal component analysis resulted in the selection of perceived exertion and seven variables of bowling exertion derived from trunk- (PlayerLoad™, trunk flexion velocity, trunk forward rotation velocity) and tibia-mounted (tibial acceleration at back foot contact, front foot contact, back foot re-contact and front foot re-contact) inertial measurement units for further analysis. Repeated measures ANOVAs were used to investigate the effect of intensity on outcome variables. Significant main effects of intensity and large effect sizes were identified for all variables (p < .05, np2 > 0.14). Measures from the match and maximal conditions were significantly larger compared with the warm-up condition (Pholm < .05). No differences were observed between the match and maximal conditions (p > .05). Inertial measurement metrics can distinguish between a warm-up effort and both match and maximal fast bowling delivery intensity. These devices provide a unique, time-efficient approach to cricket fast bowling exertion quantification.

Peak movement and impact characteristics of different training methods in professional rugby union.

The purpose of this study was to compare the peak periods (1- to 6-minute epochs) for three different training methods (game-based training - GBT; small-sided games - SSG; and conditioning training - CT) in elite male rugby union (RU) players. The peak movement (m·min-1) and impact (impact·min-1) characteristics of 42 players during in-season training were assessed. When comparing between training methods, SSG drills produced the greatest peak movement characteristics for all time epochs (1-minute average peak periods - SSG 195 m·min-1, GBT 160 m·min-1, and CT 144 m·min-1). The peak impact characteristics performed during training were 1-2 impact·min-1 for a 1-minute period and then decreased as the time period increased for all training methods. The greatest distribution of training time occurred at 30-39% (SSG and CT) and 40-49% (GBT) of peak movement intensity, with less than 5% of training performed at or above 80% peak intensity across all drill types. Findings from the current study show that the peak movement periods (m·min-1) in RU training from all three training methods match or exceed those which are previously reported in peak gameplay, yet their ability to replicate peak impact characteristics is questionable.

Load Centralization Does Not Affect the Kinetic and Kinematic Output of Countermovement Jumps.

ABSTRACT: Tredrea, MSJ, Middleton, KJ, Bourne, MN, Carey, DL, Scanlan, AT, and Dascombe, BJ. Load centralization does not affect the kinetic and kinematic output of countermovement jumps. J Strength Cond Res 36(4): 1084-1089, 2022-This study aimed to compare the kinetics, kinematics, and performance of countermovement jumps (CMJs) when completed with 2 different loading conditions (centralized or peripheral) across increasing loads. Seventeen subjects (12 men and 5 women) randomly completed 2 series of CMJs with increasing loads separated by a 30-minute rest period between conditions. Subjects were loaded with either a weighted vest (centralized) or straight barbell (peripheral). A randomized, counterbalanced crossover design was used with incremental loads of 10, 20, 30, 40, and 50% of body mass added to the vest or barbell. Measures of peak force, acceleration, velocity, and power were calculated across each subphase of the CMJs. No significant differences were observed in kinetic or kinematic variables between loading conditions. Within each condition there were significant reductions (p < 0.05) in peak concentric velocity and acceleration, as well as significant increases (p < 0.05) in peak force when the external load increased. Furthermore, braking and propulsive phase duration significantly increased (p < 0.05) and jump height significantly decreased (p < 0.05) as the external load increased. Countermovement jump performance was similar in both central and peripheral loading, whereas increasing load significantly affected jump height, force, velocity, and acceleration variables irrespective of load position. The training stimulus from an external load placed centrally or peripherally is similar regardless of where it is positioned; however, from a practical perspective, a weighted vest may provide a more mobile and safer alternative than a barbell.

Temporal distribution of peak running demands relative to match minutes in elite football.

The peak match running demands of football (soccer) have been quantified across time durations of 1-10 min, however, little is known as to when the peak match running demands occur within match play. Data were collected from 44 elite footballers, across 68 fixtures (Files = 413, mean ± SD; 11 ± 8 observations per player, range; 1-33), with peak match running demands quantified for each playing half at ten incremental rolling average durations (1 min rolling averages, 2 min rolling averages, etc.). Data were assessed if players completed the full match. Three measures of running performance were assessed total distance (TD), high-speed distance (> 19.8 km · h-1) (HSD) and average acceleration (AveAcc)], with the in-game commencement time of the peak running demands recorded. Descriptive statistics and normality were calculated for each rolling average duration, with the self-containment of shorter rolling average epochs within longer epochs also assessed (e.g. Do the 1 min peak running demands occur within the 10 min peak running demands). Peak TD and AveAcc demands occurred early in each half (median time = 7-17 min and 6-16 min, respectively). Conversely, peak HSD covered was uniformly distributed (Skewness = 0-0.5, Kurtosis = 1.7-2.0). There were low-moderate levels of self-containment for each peak match running period (10-51%), dependent upon metric. Peak match running demands for TD and AveAcc occurred at similar stages of a match where TD and acceleration volumes are typically greatest, whereas peak HSD demands appeared more unpredictable. These timings may help inform training prescriptions in preparation of athletes for competition.

Between-match variation of peak match running intensities in elite football.

Peak match running intensities have recently been introduced to quantify the peak running demands of football competition, across incremental time intervals, to inform training practices. However, their between-match variation is yet to be comprehensively reported, limiting the ability to determine meaningful changes in peak match running intensities. The current study aimed to quantify the between-match variability in peak match running intensities across discrete moving average durations (1-10 min). GPS data were collected from 44 elite football players across 68 matches (mean ± SD; 13 ± 10 observations per player). For inclusion players must have completed 70mins of a match across a minimum of two matches. Performance metrics included total and high-speed (> 19.8 km · h-1) running distances and average acceleration (m · s-2), expressed relative to time. For each metric, the coefficient of variation and smallest worthwhile difference were calculated. The peak match running intensity data was similar to previously reported data from various football competitions. The between-match CV of relative total distance ranged between 6.8-7.3%, with the CV for average acceleration and relative high-speed running being 5.4-5.8% and 20.6-29.8%, respectively. The greater variability observed for relative high-speed running is likely reflective of the varying constraints and contextual factors that differ between matches. The reported between-match variability helps to provide context when interpreting match performance and prescribing training drills using peak match running intensity data.

Cardiac 123I-MIBG normal uptake values are population-specific: Results from a cohort of controls over 60 years of age.

PURPOSE: Cardiac 123I-MIBG image interpretation is affected by population differences and technical factors. We recruited older adults without cognitive decline and compared their cardiac MIBG uptake with results from the literature. METHODS: Phantom calibration confirmed that cardiac uptake results from Japan could be applied to our center. We recruited 31 controls, 17 individuals with dementia with Lewy bodies (DLB) and 15 with Alzheimer's disease (AD). Images were acquired 20 minutes and four hours after injection using Siemens cameras with medium-energy low-penetration (MELP) collimators. Local normal heart-to-mediastinum (HMR) ratios were compared to Japanese results. RESULTS: Siemens gamma cameras with MELP collimators should give HMRs very close to the calibrated values used in Japan. However, our cut-offs with controls were lower at 2.07 for early and 1.86 for delayed images. Applying our lower cut-off to the dementia patients may increase the specificity of cardiac MIBG imaging for DLB diagnosis in a UK population without reducing sensitivity. CONCLUSIONS: Our local HMR cut-off values are lower than in Japan, higher than in a large US study but similar to those found in another UK center. UK centers using other cameras and collimators may need to use different cut-offs to apply our results.

Can target effects or discomfort ratings discriminate between small-arms weapon configurations?

Defence acquisitions use accuracy measures as a discriminating factor in weapon purchases, but assessments are generally completed in static, supported postures at static targets with few differences being seen between configurations. The aim of this study was to investigate whether an assessment requiring repositioning between shots could reveal differences. Participants shot at a static target under four conditions: an unweighted rifle and the addition of a mass fixed at three different positions. Accuracy and timing as well as discomfort measures were captured and compared. Hit percentage, consistency and timing varied over time, and timing increased with the addition of mass in two out of the three conditions. There was an increase in discomfort with the addition of mass further from the participant. The results showed that relying on accuracy and consistency measures alone to make acquisition decisions could have the consequence of purchasing equipment not fit for the human. Practitioner Summary: This research shows that relying on accuracy and consistency measures alone to make weapon-system acquisition decisions could have the consequence of purchasing equipment not fit for the user. Further research should focus on 'upstream' issues such as muscle fatigue and aim point stability in order to better understand human-weapon-system interactions.

Treadmill load carriage overestimates energy expenditure of overground load carriage.

This study compared physiological and biomechanical responses between treadmill and overground load carriage. Thirty adults completed six 10-minute walking trials across three loads (0, 20, and 40% body mass) and two surfaces (treadmill and overground). Relative oxygen consumption was significantly greater on the treadmill for 20% (1.54 ± 0.20 mL⋅kg-1⋅min-1) and 40% loads (1.08 ± 0.20 mL⋅kg-1⋅min-1). All other physiological and perceptual responses were significantly higher in the treadmill condition and with increases in load. Stance time was longer (0%: 0.05 s; 20%: 0.02 s, 40%: 0.05 s, p < 0.001) and cadence was lower (0%: 1 step·min-1; 20%: 2 steps·min-1; 40%: 3 steps·min-1, p < 0.05) on the treadmill. Peak lower limb joint angles were similar between surfaces except for ankle plantar flexion, which was 8˚ greater on the treadmill. The physiological responses to treadmill-based load carriage are generally not transferable to overground load carriage and caution must be taken when conducting treadmill-based load carriage research to inform operational-based scenarios. Practitioner Summary: Literature is limited when comparing the physiological and biomechanical responses to treadmill and overground load carriage. Using a repeated measures design, it was shown that although walking kinematics are generally similar between surfaces, there was a greater physiological demand while carrying a load on a treadmill when compared with overground. Abbreviations: BM: body mass; e.g: for example; HR: heart rate; HRmax: heart rate maximum; Hz: hertz; kg: kilograms; km·h-1: kilometres per hour; L⋅min-1: litres per minute; m: metres; MD: mean difference; mL·kg-1·min-1: millilitres per kilogram per minute; mL⋅min-1: millilitres per minute; η2p: partial-eta squared; OG: overground; RPE: rating of perceived exertion; s: seconds; SD: standard deviation; SE: standard error; steps·min-1: steps per minute; TM: treadmill; V̇CO2: volume of carbon dioxide; V̇E: ventilation; V̇O2: volume of oxygen; V̇O2max: maximum volume of oxygen; y: years.

Antibody Responses Elicited by Immunization with BG505 Trimer Immune Complexes.

Immune complex (IC) vaccines have been successfully used to increase immune responses against various pathogens, including HIV-1. Additionally, IC vaccines can induce qualitatively different antibody responses, with distinct antigenic specificities compared to the same antigens used alone. Here we measured the HIV-1-specific antibody responses in female New Zealand White rabbits after immunization with ICs made from BG505 SOSIP.664 trimers (BG505 trimers) and three rabbit monoclonal antibodies (MAbs) with different neutralization profiles. Two of the MAbs were specific for a hole in the glycan shield of the BG505 trimer, while the third, which bound less avidly, was specific for determinants at the gp41-gp120 interface. We found that immunization with one of the glycan-hole-specific ICs resulted in lower levels of trimer-binding antibodies compared to vaccination with the uncomplexed trimer, and that ICs made using either of the glycan-hole-specific MAbs resulted in lower rates of anti-trimer antibody decay. We concluded that ICs based on MAbs that bound to the immunodominant glycan hole epitope likely diverted antibody responses, to some extent, away from this site and to other regions of the trimer. However, this outcome was not accompanied by a widening of the breadth or an increase in the potency of neutralizing antibody responses compared with uncomplexed trimers.IMPORTANCE Immunodominant epitopes may suppress immune responses to more desirable determinants, such as those that elicit potentially protective neutralizing antibody responses. To overcome this problem, we attempted to mask immunodominant glycan holes by immunizing rabbits with ICs consisting of the BG505 SOSIP.664 gp140 trimer and MAbs that targeted the glycan holes. We found that IC vaccination likely diverted antibody responses, to some extent, away from the glycan holes and toward other regions of the trimer. IC vaccination resulted in slower decay of HIV-1-specific antibodies than did immunization with uncomplexed trimer. We did not observe a widening of the breadth or an increase in the potency of neutralizing antibody responses compared to uncomplexed trimers. Our results suggest that selective epitope dampening of BG505 trimers by ICs is rather ineffective. However, IC vaccination may represent a novel means of increasing the duration of vaccine-induced antibody responses.

How and when to use clozapine.

OBJECTIVE: Clozapine is the only approved strategy for treatment-resistant schizophrenia, although it is highly underutilized. We aim to generate practical and actionable evidence-based recommendations for the use of this drug considering prescription barriers. METHOD: Narrative review. RESULTS: A consistent body of evidence supports the efficacy of clozapine reducing morbidity and mortality in schizophrenia. The main obstacles to its use are the lack of experience by prescribers and perceived treatment burden. Systematic screening of eligibility, utilization of available resources for consultation, developing a professional network with other stakeholders, as well as optimizing how clozapine is presented to patients is discussed. Furthermore, specific evidence-based recommendations for initiation, maintenance, and safety monitoring with clozapine are provided. CONCLUSION: Clozapine prescription is one of the areas in psychiatry with the greatest mismatch between efficacy and utilization in clinical practice. Although multiple barriers to the use of clozapine exist, some of these may be overcome by updates of routine clinical practice.

No physiological or biomechanical sex-by-load interactions during treadmill-based load carriage.

This study investigated whether physiological demand or gait mechanics differ between sexes during treadmill load carriage. Female (n = 15) and male (n = 15) military recruit-type participants with no load carriage experience completed three 10-minute walking trials at a self-selected speed with increasing relative body-borne loads (0%, 20%, and 40% body weight). A range of cardiorespiratory, perceptual and biomechanical variables were measured. Self-selected walking speed was similar between sexes (4.6-4.8 km·h-1, p > .05) and there were no significant sex-by-load interactions for any variables. Absolute VO2 and VCO2 were greater in males (difference 175-178 mL·min-1, p < .001), however, when relative to body mass, VO2 was similar between sexes (p > .05). Across all loads, cadence was 7 ± 2 steps·min-1 faster (p = .004) and stance time was 0.06 ± 0.02 s shorter (p = .013) in females. Increasing load resulted in greater physiological demand, cadence, % stance time, and step length (p < .05). Practitioner summary: Literature comparing physiological and biomechanical variables between sexes during load carriage is scarce. Physiological and biomechanical sex differences were limited to relative measures associated with physical size (height and mass). Future research may pool male and female participants when conducting trials up to ten minutes in length. Abbreviations: BW: body weight; COM: centre of mass; HR: heart rate; HRmax: maximum heart rate; RER: respiratory exchange ratio; RPE: rating of perceived exertion; VCO2: volume of carbon dioxide; VE: ventilation; VO2: volume of oxygen; VO2max: maximum volume of oxygen.

Race influences survival in glioblastoma patients with KPS ≥ 80 and associates with genetic markers of retinoic acid metabolism.

PURPOSE: To study whether the clinical outcome and molecular biology of gliomas in African-American patients fundamentally differ from those occurring in Whites. METHODS: The clinical information and molecular profiles (including gene expression array, non-silent somatic mutation, DNA methylation and protein expression) were downloaded from The Cancer genome atlas (TCGA). Electronic medical records were abstracted from Northwestern Medicine Enterprise Data Warehouse (NMEDW) for analysis as well. Grade II-IV Glioma patients were all included. RESULTS: 931 Whites and 64 African-American glioma patients from TCGA were analyzed. African-American with Karnofsky performance score (KPS) ≥ 80 have significantly lower risk of death than similar white Grade IV Glioblastoma (GBM) patients [HR (95% CI) = 0.47 (0.23, 0.98), P = 0.0444, C-index = 0.68]. Therefore, we further compared gene expression profiles between African-American GBM patients and Whites with KPS ≥ 80. Extrapolation of genes significantly associated with increased African-American patient survival revealed a set of 13 genes with a possible role in this association, including elevated expression of genes previously identified as increased in African-American breast and colon cancer patients (e.g. CRYBB2). Furthermore, gene set enrichment analysis revealed retinoic acid (RA) metabolism as a pathway significantly upregulated in African-American GBM patients who survive longer than Whites (Z-score = - 2.10, Adjusted P-value = 0.0449). CONCLUSIONS: African Americans have prolonged survival with glioma which is influenced only by initial KPS score. Genes previously associated with both racial disparities in cancer and pathways associated with RA metabolism may play an important role in glioma etiology. In the future exploration of these genes and pathways may inform novel therapies for this incurable disease.

Understanding Anthropometric Characteristics Associated With Performance in Manual Lifting Tasks.

Beck, B, Middleton, KJ, Billing, DC, Caldwell, JN, and Carstairs, GL. Understanding anthropometric characteristics associated with performance in manual lifting tasks. J Strength Cond Res 33(3): 755-761, 2019-Manual lifting is an essential military job task and is commonly linked to occupational injury. Methods to reduce injury risk focus on ensuring that employees have the requisite physical capacity to safely conduct critical job tasks. The aim of this study was to investigate which anthropometric characteristics are associated with lifting performance to inform targeted training programs for job-critical lifting tasks. Sixty-three (42 men and 21 women) participants conducted 3 maximal lifts to a platform (pack lift to 1.5 m, box lift to 1.3 m and box lift to 1.5 m). A dual-energy x-ray absorptiometry scan was used to quantify anthropometric characteristics (body region-specific lean mass and fat mass). Although anthropometric measures were strongly associated with each other, multivariable linear regression revealed that a significant proportion of the total variation in lifting performance in each of the 3 tasks was explained by upper-arm lean mass (pack lift: ß = 5.42, p < 0.001; box lift 1.3 m: ß = 5.64, p < 0.001; box lift 1.5 m: ß = 7.00, p < 0.001). Leg lean mass also significantly contributed to the variation of pack lift performance (ß = 0.93, p = 0.01). When controlling for key anthropometric characteristics in these 3 tasks, separate analyses showed no significant effect of sex or stature on lift performance. These results suggest that the perceived limitations of stature and sex may be overcome by targeted training programs to improve specific physical characteristics associated with lifting performance.