Search

Objective To critically assess the literature focused on sex-specific trajectories in physical characteristics associated with anterior cruciate ligament (ACL) injury risk by age and maturational stage. Data Sources PubMed, CINAHL, Scopus, and SPORTDiscus databases were searched through December 2021. Study Selection Longitudinal and cross-sectional studies of healthy 8- to 18-year-olds, stratified by sex and age or maturation on ≥1 measure of body composition, lower extremity strength, ACL size, joint laxity, knee-joint geometry, lower extremity alignment, balance, or lower extremity biomechanics were included. Data Extraction Extracted data included study design, participant characteristics, maturational metrics, and outcome measures. We used random-effects meta-analyses to examine sex differences in trajectory over time. For each variable, standardized differences in means between sexes were calculated. Data Synthesis The search yielded 216 primary and 22 secondary articles. Less fat-free mass, leg strength, and power and greater general joint laxity were evident in girls by 8 to 10 years of age and Tanner stage I. Sex differences in body composition, strength, power, general joint laxity, and balance were more evident by 11 to 13 years of age and when transitioning from the prepubertal to pubertal stages. Sex differences in ACL size (smaller in girls), anterior knee laxity and tibiofemoral angle (greater in girls), and higher-risk biomechanics (in girls) were observed at later ages and when transitioning from the pubertal to postpubertal stages. Inconsistent study designs and data reporting limited the number of included studies. Conclusions Critical gaps remain in our knowledge and highlight the need to improve our understanding of the relative timing and tempo of ACL risk factor development.

Purpose The fused filament fabrication (FFF) process is an additive manufacturing technique used in engineering design. The mechanical properties of parts manufactured by FFF are influenced by the printing parameters. The mechanical properties of rigid thermoplastics for FFF are well defined, while thermoplastic elastomers (TPE) are uncommonly investigated. The purpose of this paper is to investigate the influence of extruder temperature, bed temperature and printing speed on the mechanical properties of a thermoplastic elastomer. Design/methodology/approach Regression models predicting mechanical properties as a function of extruder temperature, bed temperature and printing speed were developed. Tensile specimens were tested according to ASTM D638. A 3×3 full factorial analysis, consisting of 81 experiments and 27 printing conditions was performed, and models were developed in Minitab. Tensile tests verifying the models were conducted at two selected printing conditions to assess predictive capability. Findings Each mechanical property was significantly affected by at least two of the investigated FFF parameters, where printing speed and extruder temperature terms influenced all mechanical properties (p < 0.05). Notably, tensile modulus could be increased by 21%, from 200 to 244 MPa. Verification prints exhibited properties within 10% of the predictions. Not all properties could be maximized together, emphasizing the importance of understanding FFF parameter effects on mechanical properties when making design decisions. Originality/value This work developed a model to assess FFF parameter influence on mechanical properties of a previously unstudied thermoplastic elastomer and made property predictions within 10% accuracy.

Contemporary research indicates that Black American men encounter multiple obstacles in higher education settings. Understanding the complexities of how Black men perceive and make sense of academic environments requires addressing a number of elements that influence their academic success. The purpose of this study is to investigate the academic advising challenges faced in virtual environments by Black men during the COVID-19 pandemic. This qualitative case study provides detailed accounts of ten Black men navigating academic advising practices in a virtual setting at large research one historically white institution using focus groups as a method of data collection. Implications and suggestions for future research highlight the significance of supporting Black men in virtual academic advising spaces to create equitable and sustainable practices.

We use the Pasyanos and Chiang (2022) data set to calculate the seismic moment M0 for each explosion and use the measured explosive yield W to validate the W∼M0 relationship in Denny and Johnson (1991; hereafter, DJ91). The M0 is corrected by transforming to a potency tensor and applying more appropriate near-source geophysical parameter values in the moment estimate. The mean residual between observed and predicted yield is near zero; however, the standard deviation of the residuals results in an F-value (a 95% confidence factor) of about 5. We re-estimate the coefficients in the DJ91 model and find similar values and only a slight improvement in the F-value. Next, we embark on a similar model selection process as DJ91, allowing for non-cube-root yield scaling and other plausible near-source elastic moduli. As was found by DJ91, the yield dependence is not significantly different from unity, and a cube root assumption is valid. Therefore, we yield scale the seismic moment and test the significance of all plausible explanatory variables. Isotropic moment performs better in the response variable than total moment. The preference for isotropic moment could be due to its relationship to volume change, which would be more directly affected by explosive yield. Surprisingly, we find that the overburden pressure, which is a function of depth, is not a significant parameter in the model. We hypothesize that this is due to the competing depth effects on source asymmetry and the incorporation of depth in the Green’s functions used to calculate the seismic moment tensors. Importantly, this emphasizes that only seismic moment tensor-derived moments should be used in these models. After removing insignificant model parameters, we are left with a simple model to predict explosive yield W^ in kt from isotropic moment MI in N·m, W^=κ−1.4132 100.035626GPMI, in which κ and GP are the near-source bulk modulus and gas porosity in Pa and %, respectively. The F-value for this model is approximately 3.

As a chemical explosion is buried, the mechanism for acoustic wave generation transitions from fully gas-generated at the surface to completely spall-induced at full containment depth. The fully gas-generated and completely spall-induced signals in the acoustic waveform are well described; however, the transition between these two end-members eludes numerical modeling because of the complex phenomena that are involved. The phenomena of crater formation and explosive cloud evolution are simulated using an Eulerian hydrocode that incorporates geomaterials with strength and porosity. Having accurately modeled these phenomena, we can confidently predict the propagation and relative strength of the gas-generated and spall-induced pulses in the recorded acoustic waveform. The numerical predictions agree with observations from the historical Stagecoach experiment as well as modern recordings from the Source Physics Experiment. In particular, the peak pressure p generated by an explosion is initially due to the gas-generated mechanism and decays with scaled depth of burial ds (depth d scaled by the cube-root of explosive yield w1/3) as exp(−ds) but then transitions near a scaled depth of 6 m/ton1/3 to the spall-generated mechanism in which the decay is ds−7/4. This decay form is related to the strong ground-motion attenuation relationship that affects spall strength. These results can improve seismoacoustic inverse models for the explosive source that need to account for the gas-generated and spall-induced signals and their effect on peak pressures and other acoustic signal features.

Motor vehicle collisions (MVCs) are the leading cause of unintentional death among children and adolescents; however, public awareness and use of appropriate restraint recommendations are perceived as deficient. We aimed to investigate the use of child safety restraints and examine outcomes in our community.We retrospectively queried a level 1 trauma registry for pediatric (0-18 y) MVC patients from October 2013 to December 2018. Demographic and clinical variables were recorded. Data regarding appropriate restraint use by age group were examined.Four hundred thirty-four cases of pediatric MVC were identified. Overall, 53% were improperly restrained or unrestrained. Sixty-two percent of car seat age and 51% of booster age children were improperly restrained or unrestrained altogether. Fifty-nine percent of back seat riding, seatbelt age were improperly restrained/unrestrained, with 26% riding in the front. Fifty-one percent of seatbelt-only adolescents were not belted. Black, non-Hispanic children were more often improperly restrained/unrestrained compared to Hispanics (63% versus 48%, P = 0.001). Improperly restrained/unrestrained children had higher injury severity (10% versus 4% Injury Severity Score25, P = 0.021), require operative/interventional radiology (33% versus 19%, P = 0.001), and be discharged to rehabilitation or skilled nursing facility (5.2% versus 1.5%, P = 0.033). Mortality in adolescents was higher among those unrestrained (5.2% versus 0.8%, P = 0.034).Although efforts to improve adherence to restraint regulations have greatly increased in the last decade, more than half of children in MVC are still improperly restrained. Injury prevention services and community outreach is essential to educate the most vulnerable populations, especially those with infants and toddlers, on adequate motor vehicle safety measures in our community.

Studies have found no or minimal differences in running kinematics between flexible and inflexible adult runners. The interaction between hamstring flexibility and running kinematics has not been reported in adolescent long-distance runners.Does hamstring flexibility influence running kinematics in adolescent long-distance runners?Adolescent long-distance runners (n = 140, ages 9-19) were enrolled in our cross-sectional study. Hamstring flexibility was assessed with the forward bending Beighton task. Runners were categorized if they tested positive or negative on the forward bending task. Participants ran at a comfortable self-selected speed on a treadmill. Runners who tested positive on the forward bending task (n = 17) were matched with runners who tested negative on the task (n = 17) according to sex, physical maturation, and running speed. Statistical parametric mapping compared trunk, pelvis, hip, and knee kinematic waveforms throughout the gait cycle and independent sample t tests compared temporal-spatial parameters between the groups.Runners who tested positive on the forward bending task demonstrated significantly greater anterior pelvic tilt during stance (average difference = 4.8° ± 0.4°, p .001) and swing (average difference = 4.3° ± 0.2°, p .01) compared to runners who tested negative on the forward bending task. No significant differences were found between groups for the remaining kinematic waveforms or for any temporal-spatial parameters (p .05).This is the first study to report the interaction between hamstring flexibility and running kinematics in adolescent long-distance runners. The greater anterior pelvic tilt demonstrated by runners with greater hamstring flexibility may place more eccentric demands on the hamstring musculature. However, as there were no other differences in joint kinematics or temporal-spatial parameters between groups, greater hamstring flexibility does not appear to have a significant interaction with running kinematics when running at sub-maximal speeds. Our results suggest hamstring flexibility does not predispose adolescent long-distance runners to sub-optimal segment positions associated with running-related injuries.

Taylor, JB, Barnes, HC, Gombatto, SP, Greenwood, D, and Ford, KR. Quantifying external load and injury occurrence in women's collegiate volleyball players across a competitive season. J Strength Cond Res 36(3): 805-812, 2022-Volleyball demands repetitive jumping, with high loads linked to risk of injury. The purpose of this study was to examine jumping demands and injury patterns throughout a women's volleyball season. Sixteen Division-I female volleyball players wore an accelerometer to record jump count (JC) and jump height during every practice and match throughout the season. Physical health was documented using a weekly modified Oslo Sports Trauma Research Center Overuse Injury Questionnaire (OSLO) and time-loss injuries were recorded. Multivariate analyses of variance were used to compare measures across phases of the season, between types of session (practice vs. match), and between injured and noninjured players (α = 0.05). Results showed the greatest training demands in the preseason with larger jump counts than during the nonconference, conference schedule, and postseason schedules (p0.001). Performance increased throughout the season with greater jump heights in the nonconference and conference schedule than in the preseason (p = 0.01). There were no significant differences in JC between practices (65.5 ± 30.5) and matches (67.5 ± 46.4). An injury incidence of 5.49 injures per 1,000 athletic exposures was identified, with injuries accounting for 31 days lost, or 2.1% of total exposures. Injuries affected performance throughout the season, as noted by an average weekly OSLO score of 15.1 ± 13.9%. Injured players had significantly lower jump counts per exposure (p = 0.03) and a larger variation in training load than uninjured players (coefficient of variation: injured = 54%, uninjured = 41%; p = 0.006). These data help provide coaches and clinicians for training and rehabilitation program designs.

We examined whether practice activities adopted by professional youth soccer coaches are modulated through the implementation of and engagement with cocreative evidence-based programs. Across two experiments, we used systematic observation to identify the practice activities of seven coaches across 134 sessions. In Experiment A, drill-based and games-based activities were recorded and quantified. To encourage behaviour change across the study, the systematic observation data were compared with skill acquisition literature to provide coaches with quantitative feedback and recommendations during workshops. Postworkshop systematic observation data indicated that practice activities used by coaches changed in accordance with the evidenced-based information (increase in games-based activities) delivered within the workshop. Interview data indicated that coaches typically stated that the workshop was a key reason for behaviour change. In a follow-up Experiment B, feedback and recommendations were delivered using an interactive video-based workshop. The systematic observation data indicated that coaches increased the use of soccer activities that contained active decision making with coaches citing the workshop as a key reason for behaviour change. These findings indicate that coaching practice activities can be supported and shaped through the implementation of cocreated workshops wherein coaches collaborate with sport scientists and researchers to bridge the gap between science and application.

Introduction: Breast cancer survivorship guidelines from the American Cancer Society (ACS) and American Society of Clinical Oncologists (ASCO) contain recommendations for health promotion, specifically obesity, nutrition, and physical activity. Breast cancer treatment is often cardiotoxic because of anthracycline- based drugs, radiation therapy, and use of monoclonal antibodies. Many African American (AA) BCS have preexisting conditions such as hypertension, obesity, and diabetes when diagnosed with breast cancer. Evidence suggests that breast cancer survivors (BCS) with sedentary lifestyles, obesity, and lack of physical activity have poorer outcomes among survivors. Research indicates AA BCS are less likely to be encouraged to lose weight or participate in physical activity by healthcare providers. Hypotheses: 1) Physical inactivity, smoking, and suboptimal dietary patterns adversely affect cardiovascular health and survival of AA female BCS; and 2) Socioeconomic, cultural, and environmental factors serve as barriers or facilitators to adopting heart healthy behaviors and health outcomes. Methods: The sample consisted of 14 participants in three focus groups. Because these women had been discharged from acute oncology care, they were recruited from the AA community in Greensboro and Durham, NC. The organizations included cancer survivor organizations, religious and community organizations, and by referral from participants. Focus groups were held in locations that provided privacy for participants to verbally express themselves and interact with others freely. Anthropometric and biomarker data were collected from each participant and are reported elsewhere. Results: Using thematic analysis, verbatim transcripts were analyzed using word processing software. We familiarized ourselves with the focus group data, and continued with coding, theme generation, review and naming. The overarching themes identified were eating habits, thoughts about exercise, thoughts about weight, physician advice, and the importance of regular exercise. Conclusions: In conclusion, because many BCS are at risk for late and long-term cardiac effects of cancer treatment therapies, it is advisable to promote cardiovascular health behaviors that connect other health recommendations as suggested by the American Heart Association’s Life’s Simple 7. Accordingly, it is necessary to assess socioeconomic, cultural, and environmental factors that may influence heart healthy behaviors and health outcomes before creating culturally relevant interventions.

Global environmental change is identified as a driver of physical transformation of coral reef islands over the past half-century, and next 100 years, posing major adaptation challenges to island nations. Here we resolve whether these recent documented changes in islands are unprecedented compared with the pre-industrial era. We utilise radiometric dating, geological, and remote sensing techniques to document the dynamics of a Maldivian reef island at millennial to decadal timescales. Results show the magnitude of island change over the past half-century (±40 m movement) is not unprecedented compared with paleo-dynamic evidence that reveals large-scale changes in island dimension, shape, beach levels, as well as positional changes of ±200 m since island formation ~1,500 years ago. Results highlight the value of a multi-temporal methodological approach to gain a deeper understanding of the dynamic trajectories of reef islands, to support development of adaptation strategies at timeframes relevant to human security.

Small/er soccer nations rely strongly on developing youth athletes into experts in adulthood due to financial, logistical, and\ud coach education constraints. One factor that contributes to this expertise is activities engaged in during childhood.\ud Researchers have described these activities by focusing on larger, well-developed countries that often have larger participation rates and higher competition levels than their smaller counterparts. Therefore, to provide more specific information to support talent development in smaller soccer nations, a survey of the youth development system of a small\ud soccer nation was conducted, alongside recording the developmental activities of skilled and less-skilled soccer players\ud within this system. Key stakeholders (e.g., technical director) completed a youth development system survey. Skilled soccer players (n = 12) who were representing their country at U17 level and less-skilled players (n = 13) that had never\ud played for their country completed a Participation History Questionnaire. Skilled players engaged in significantly higher\ud amounts of individual practice in both childhood and early adolescence compared to less-skilled players. Survey data indicated that the greater amounts of individual practice for the skilled players stemmed from a lack of finances, playing facilities, and a formal coach education program. Results from this study may inform future practices and processes in the\ud youth development systems of small/er soccer nations and their national associations.

Background: Social, behavioural, and administrative sciences are among the Accreditation Council of Pharmacy Education (ACPE) mandated foundational knowledge requirements for pharmacy school curricula. However, they are often taught in isolation, whereby students lose sight of their meaning and significance in the Pharmacists’ Patient Care Process (PPCP). Objective: The objective was to assess performance and critical thinking skills and explore student perceptions of a Longitudinal Patient Case assignment that integrates knowledge from multiple domains into a learning experience exploring how patients and pharmacists navigate the complexities of the US healthcare system. Methods: Student pharmacists developed their case throughout the term by incorporating course concepts, then submitted a narrated PowerPoint presentation. Quantitative data sources included overall scores, scores for each domain, midterm and final examination scores, and final course grades, analysed using descriptive statistics and Pearson’s correlation. Student reflections encouraged self-discovery and professional identity development and served as the qualitative data source. Thematic analysis occurred through a multi-phase approach. Results: All first-year student pharmacists (n = 153) participated. Scores on the narrated PowerPoint were significantly correlated with midterm and final exams and were moderately correlated with overall course grades. Themes that evolved from students’ self-reflections focused on project execution and learning/knowledge. Conclusions: Synthesising and applying content across a course in this manner enables students to make connections, think critically, and be creative.

Development and performance of an endpoint-constrained (EPC) extended Kalman filter (EKF) was published by Haug and Ford, where the EPC EKF was shown to outperform similar non-EPC EKFs against highly maneuverable anti-ship cruise missile (ASCM) trajectories. The purpose of this paper is to resolve two issues identified during the original study. The first issue is that EKFs may not offer superior performance when the target's motion is highly nonlinear. The second issue is that the EPC EKF performs poorly against the high diver trajectory, where the target does not satisfy the EPC until the dive begins. This paper presents a new filter which uses a modified version of the EPC and a multiple model algorithm to achieve superior performance against a larger set of ASCM trajectories than the EPC EKF.

This presentation describes the progress in the development of two domain specific languages for weather and climate applications, PSyclone and gt4py (formerly dusk/dawn). Several models ofESiWACE-2 have been ported and adapted to use the DSLs: NEMO, ICON, LFric and IFS.&nbsp

Objectives: This study focuses on identifying variations in selected CYP genes related to treatment responses in patients with HIV in African populations by investigating variant characteristics and effects in African cohorts. Design: Cytochrome P450 (CYP) 2A6, 2B6, and Uridine 5’-diphospho-glucuronosyltransferase (UGT) 2B7 allele frequencies were studied using public-domain datasets obtained from the 1000 Genomes Phase 3 project, the African Genome Variation Project (AGVP), and the South African Human Genome Programme (SAHGP). Methods: Variant annotations were performed using self-identified ethnicities to conduct allele frequency analysis in a population-stratification-sensitive manner. The NCBI DB-SNP database was used to identify documented variants and standard frequencies, and the E! Ensembl Variant Effect Predictor tool was used to perform the prediction of possible deleterious variants. Results: A total of 4468 variants were identified across 3676 individuals following pre-filtering. Seventy-one variants were identified at an allelic frequency (1% or more in at least one population), which were predicted to be linked to existing disease associations and, in some cases, linked to drug metabolisms. This list was further studied to identify 23 alleles with disease considerations found at significantly different frequencies in one or more populations. Conclusions: This study describes allele frequencies observed in African populations at significantly different frequencies relative to at least one other reference population and identifies a subset of variants of clinical interest. Despite the inclusion of mixed sequence coverage datasets, the variants identified pose notable avenues for future inquiries. A subset of variants of clinical interest with statistically significant inter-population frequency differences was identified for further inspection, which provides evidence of an African population-specific variant frequency profile. This study highlights the need for additional research and African genetics data given the presence of this unique frequency profile to better facilitate the genetic pre-screening of patients as a standard of practice in HIV care, particularly on the African continent where HIV is highly prevalent.