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Introduction Blast overpressure and accelerative impact can produce concussive-like symptoms in service members serving both garrison and deployed environments. In an effort to measure, document, and improve the response to these overpressure and impact events, the U.S. Army Medical Material Development Activity is evaluating body-worn sensors for use by the Joint Conventional Force. In support, the WRAIR completed a qualitative end-user evaluation with service members from high-risk mission occupational specialties to determine the potential needs, benefits, and challenges associated with adopting body-worn sensors into their job duties. Materials and Methods WRAIR staff led hour-long semi-structured focus groups with 156 Army, Navy, and Marine Corps participants, primarily representing infantry, combat engineer, explosive ordnance disposal, artillery, mortar, and armor job specialties. Topics included their sensor needs, concepts of operations, and recommended design features for implementing sensors into the force. Dialogue from each focus group was audio recorded and resulting transcripts were coded for thematic qualitative analysis using NVivo software. Results Users recommended a single, unobtrusive, rugged, multi-directional sensor that could be securely mounted to the helmet and powered by a battery type (such as rechargeable lithium or disposable alkaline batteries) that was best suited for their garrison and field/deployed environments. The sensors should accurately measure low-level (∼1.0 pounds per square inch) blasts and maintain a record of cumulative exposures for each service member. Discussions supported the need for immediate, actionable feedback from the sensor with the option to view detailed blast or impact data on a computer. There were, however, divergent opinions on security issues regarding wireless versus wired data transfer methods. Participants also expressed a need for the exposure data to integrate with their medical records and were also willing to have their data shared with leadership, although opinions differed on the level of echelon and if the data should be identifiable. Regarding accountability, users did not want to be held fiscally liable for the sensors and recommended having the unit be responsible for maintenance and distribution. Concerns about being held fiscally liable, being overly burdened, and having one's career negatively impacted were listed as factors that could decrease usage. Finally, participants highlighted the importance of understanding the purpose and function of the sensors and supported a corresponding training module. Conclusions Participating service members were generally willing to adopt body-worn sensors into their garrison and deployed activities. To maximize adoption of the devices, they should be convenient to use and should not interfere with service members' job tasks. Providing a clear understanding of the benefits (such as incorporating exposure data into medical records) and the function of sensors will be critical for encouraging buy-in among users and leaders. Incorporating end-user requirements and considering the benefits and challenges highlighted by end users are important for the design and implementation of body-worn sensors to mitigate the risks of blast overpressure and accelerative impact on service members' health. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic disrupted the daily life and routines of Americans across the United States (U.S.), including those of our active-duty service members (ADSMs). Limited movement orders enacted during this time to promote social distancing prohibited access to fitness and dining facilities for ADSMs. This study aims to expand on previous work identifying changes in body mass index (BMI) among U.S. Army service members by identifying changes in body mass index (BMI) among active-duty service members from both the Navy and Marine Corps during the same time period. Methods: We conducted a retrospective cohort study of active-duty service members from the Navy and Marine Corps using data from the Military Health System Data Repository. BMI was calculated and categorized according to CDC guidelines both before (February 2019 - January 2020) and during the pandemic (September 2020 - June 2021). Women who were pregnant or delivered during and one year prior to the study periods were excluded. Statistical analyses included paired t-tests evaluating mean BMI, percent change, and the Stuart-Maxwell test for marginal homogeneity. Results: We identified 98,330 active-duty Sailors and 55,298 active-duty Marines for inclusion in this study. During the pandemic period the percentage of Sailors with Underweight decreased by 11%, Healthy weight decreased by 11.1%, Overweight increased by 2.1%, and the percentage of Sailors with Obesity increased by 16.5%. During this same time period, Marines with Underweight decreased by 1%, Healthy weight decreased by 16%, Overweight increased by 3.0%, and Marines with Obesity increased by 51%. The largest increases in service members with overweight and obesity observed among both cohorts were among female service members, service members under age 20, and service members with a Junior Enlisted rank. Conclusions: Significant increases in obesity were observed amongst active-duty United States Navy and Marine Corps service members during DoD pandemic mitigation efforts. Increased rates of obesity likely effected fitness and force readiness. Future interventions should be targeted at younger, Junior-Enlisted Marines and Sailors to promote healthy lifestyles and provide education on nutrition, appropriate exercise, sleep hygiene, and stress management. [ABSTRACT FROM AUTHOR]

Introduction Musculoskeletal injuries (MSIs) occur frequently in military personnel. U.S. Marine Corps (USMC) recruits participate in an intense 13-week training program designed to transform civilians into basically trained Marines, during which they are susceptible to MSIs. Previous injury epidemiology research with USMC recruits was conducted in a non-gender-integrated training. Data for the current study were derived from a larger study, the USMC Gender-Integrated Recruit Training study, that was initiated to provide data-driven recommendations for gender integration during USMC recruit training. The purpose of the current analysis was to describe the unique profile of MSIs during USMC recruit training and compare MSIs between female and male recruits in gender-integrated training. Materials and Methods Medical record–reviewed MSI data were obtained for recruits in three models of USMC recruit training: two models of gender-integrated recruit training at Marine Corps Recruit Depot (MCRD) Parris Island—the older Series Track (ST) model and the newer Integrated Company (IC) model, and a Male-Only (MO) cohort at MCRD San Diego. Incidence, anatomic region and subregion, event at the time of MSI, MSI type and onset, and disposition following MSI were described for each model. Group comparisons were conducted using Fisher's exact tests or independent samples t tests, as appropriate. Results MSI data were available for 584 recruits (ST: 98 female recruits, 95 male recruits; IC: 85 female recruits, 106 male recruits; MO: 200 male recruits). The cumulative incidence of MSIs was significantly higher among female compared to male recruits in the ST (59.2% vs. 29.5%, P  < .001) and in the IC (25.9% vs. 12.3%, P = .023) cohorts. The most frequent anatomic location for MSIs was the lower extremity (female recruits: ST: 76.5% of MSIs, IC: 88.6%; male recruits: ST: 81.1%, IC: 80.0%, MO: 83.8%). The most frequent body part affected was the hip among female recruits (ST: 26.5% of MSIs, IC: 37.1%). The most frequent body part affected by MSIs among the male recruits was the knee in the ST (32.4%) and IC (53.3%) cohorts and the lower leg (27.0%) in the MO cohort. A significantly greater percentage of female compared to male recruits sustained a hip MSI in the ST (23.5% vs. 2.1%, P  < .001) and IC (12.9% vs. 0.0%, P  < .001) cohorts. There was no significant difference in knee MSI incidence between sexes in the ST (P  = .323) or IC (P  = .757) cohorts. A large percentage of MSIs resulted in light duty (female recruits: ST: 69.4% of MSIs, IC: 74.3%; male recruits: ST: 64.9%, IC: 73.3%, MO: 94.6%). Conclusions This was the first study to assess the burden of MSIs concurrently among female and male USMC recruits in gender-integrated training. MSIs, especially those affecting the lower extremity, continue to occur frequently in this population. Female recruits are more susceptible to MSIs during USMC recruit training compared to male recruits and are especially prone to hip MSIs. Future research should focus on identifying modifiable risk factors for MSIs in this population, with a focus on reducing lower-extremity MSIs in all recruits and hip MSIs in female recruits. [ABSTRACT FROM AUTHOR]

Introduction Recruit training is designed to transform civilians into physically fit military service members, who embody their service's core values and possess military discipline and skills. At the time this research began, the U.S. Marine Corps (USMC) remained the only service that segregated recruits by gender at the lowest unit level (e.g. platoon) and employed gender-segregated drill instructor teams. USMC's Marine Corps Recruit Depots (MCRD) must comply with a 2020 Congressional Mandate to not segregate training by gender in Parris Island by 2025 and San Diego by 2028. In turn, USMC requested an independent scientific study to analyze current approaches to gender integration at recruit training to propose alternate models and other policy recommendations that increase gender integration while maintaining current USMC standards. The Marine Corps is currently evaluating alternate models and recommendations to optimize entry-level training. This article outlines considerations for choosing the optimal research study design, research methods, and types of data collected in a study intended to provide policy recommendations on gender-integrated recruit training for the USMC. Materials and Methods Research data were collected during visits to the MCRDs and selected recruit training locations for the Army, Air Force, Navy, and Coast Guard. Data collection on USMC recruits from three cohorts involved social science assessments (focus groups and surveys) and human performance testing (countermovement jumps and isometric mid-thigh pulls, sleep and activity wearables, and cortisol data) at multiple points in the training cycle. Data on recruits from the sister services were limited to social science assessments. Approximately 600 recruits between the two MCRDs and 160 recruits from the sister services participated in the study during a 7-month timeframe in 2021. The research team conducted extensive ethnographic observations of recruit training at all selected research sites and interviewed training cadre, drill instructors, and service leadership responsible for recruit training (∼90 interviews). Additionally, the research team interviewed 20 experts on gender integration or recruit training who possessed alternate viewpoints from the current USMC practice. Results The mixed methods study was designed to assess the current gender integration practices at recruit training across the services to generate alternative models of gender integration for USMC. The research team developed a set of multidisciplinary objectives and research questions serving as the foundation of the research study design and data collection process. The study was designed to collect qualitative, quantitative, and administrative data informed by social science and human performance disciplines. To ensure that all aspects and implications relevant to gender integration were considered, select data were collected across services and with stakeholders at all levels. Conclusions This multidisciplinary research approach provided a comprehensive picture of the current USMC recruit training models. The research team captured multiple perspectives and data points for analysis through an expansive view on gender integration across all services, by interacting with participants at all levels of the institutions in varied ways. The information and data gathered enabled the research team to establish objective, data-driven alternate models, and recommendations for enhancing gender integration at recruit training for the USMC. [ABSTRACT FROM AUTHOR]

Introduction Injury epidemiology research with military populations typically utilizes data obtained through medical chart review (MCR) or injury self-reports (ISRs). MCR data will not capture musculoskeletal injury (MSKI) data for which medical care was not sought, which is common during military recruit training. Injury self-report is affected by issues with recall, especially for MSKIs perceived as less severe. U.S. Marine Corps (USMC) recruits participate in an intense 13-week recruit training program during which they are susceptible to MSKIs. The purpose of the current analysis was to utilize a novel statistical method, the capture-recapture (CRC) technique, to account for the undercounting inherent in MSKI data sources and estimate the ascertainment-corrected cumulative incidence of MSKIs during USMC recruit training. Materials and Methods Data for the current study were derived from a larger study, the USMC Gender-Integrated Recruit Training Study, which was initiated to provide data-driven recommendations to increase gender integration in USMC recruit training. The estimated cumulative incidence of MSKIs during 13-weeks of USMC recruit training was calculated from the 2 sources of MSKI data (MCR, ISR) and using CRC analysis. Medical charts were reviewed to extract data about MSKIs that occurred during recruit training. Self-reported MSKI data for the same period were obtained from recruits at the end of recruit training. MSKIs were classified according to their anatomical location and type. The Chapman modification of the Lincoln-Peterson estimator was utilized to conduct the CRC analysis. Results Medical chart review and ISR MSKI data were available for 464 USMC recruits (age: 19.1 ± 1.9 years; gender: men 70.0%). The observed 13-week cumulative incidence of MSKI in the sample was 21.8% in the MCR and 28.4% in the ISR, while the CRC incidence was much higher (62.0%). The MCR and ISR ascertainment were 35.1% and 45.9%, respectively, while the overall ascertainment or completeness of MSKI data when 2 sources were used was moderate (65.0%). When stratified by MSKI anatomical location, the overall ascertainment varied by anatomical location of the MSKI. It was highest for lower extremity MSKIs (64.8%), but lower for upper extremity (38.9%) and spine (33.3%) MSKIs. The overall ascertainment also varied by MSKI type; it was highest for sprain (55.1%), followed by strain (54.8%), and the pain/spasm/ache (43.3%). Conclusions This was the first study to utilize the CRC technique to access the ascertainment-corrected incidence of MSKIs among USMC recruits. There was significant undercounting in both sources of the data analyzed, and the extent of undercounting varied by both MSKI anatomical location and type. When 2 sources of data were utilized simultaneously, the percent of CRC-estimated MSKIs observed from 2 sources of data was more complete. There is a need for further application of the CRC technique to MSKI data in military populations to provide a more complete assessment of MSKIs. Identification of modifiable factors that influence completeness of MSKI data obtained during military recruit training is also warranted. [ABSTRACT FROM AUTHOR]

Introduction Elevated rates of musculoskeletal injuries (MSIs) and attrition are documented in military recruit training. By identifying and addressing modifiable risk factors, the rate of successful training completion and military readiness can be enhanced. Despite their impact, the causes of MSIs and attrition among U.S. Marine Corps (USMC) recruits remain underexplored. This study investigates demographic, psychological, and physiological predictors of MSIs and attrition among USMC recruits. Materials and Methods In this prospective cohort study, we evaluated USMC recruits at Marine Corps Recruit Depot, Parris Island and San Diego. Recruits were briefed and invited to volunteer. All recruits who were medically cleared to participate in recruit training were eligible to participate in the study. We gathered baseline data on potential predictors at the start of training, with follow-up data on MSIs and attrition collected post-training. Analyzed predictors encompassed dynamic and static strength measures from countermovement jumps, isometric mid-thigh pulls; and participant surveys. We employed multiple logistic regression to discern risk factors for MSI and attrition. Results Our study comprised 584 USMC recruits (183 female recruits, 19.49 ± 1.88 years, 160.10 ± 7.17 cm, 61.19 ± 8.05 kg; 401 males, 18.94 ± 1.92 years, 172.97 ± 7.26 cm, 73.86 ± 11.04 kg). We observed 193 MSIs in 135 recruits, with 80.31% affecting the lower extremity (LE). Notably, lower relative peak power (odds ratio [OR] 0.91 [0.89, 0.94], P  < .001) and shorter eccentric deceleration duration (OR 0.99 [0.99, 1.00], P  = .005) were significant predictors of MSIs. Specifically, for LE MSIs, similar trends were noted for relative peak power and eccentric deceleration duration, with additional risks associated with lower body mass index (OR 0.93 [0.86, 0.99], P  = .036) and previous LE MSIs (OR 2.25 [1.18, 4.27], P  = .013). Attrition was more likely with a reduced eccentric deceleration impulse (OR 0.98 [0.97, 0.99], P  < .001) and prolonged time to peak force (OR 1.36 [1.17, 1.59], P  < .001) and cigarette use (OR 2.12 [1.01, 4.43], P  = .046). Conclusions MSIs and attrition during USMC recruit training significantly undermine force readiness and escalate costs. Our research has pinpointed several modifiable risk factors, chiefly reduced muscular power and cigarette smoking. We advocate for neuromuscular training programs to bolster strength and power, integrated nutrition and exercise strategies for optimal body composition, and support for smoking cessation to alleviate the incidence of MSIs and curtail attrition. Initiating training with a gradual increase in activity intensity can provide a critical window to correct pre-existing neuromuscular imbalances and weaknesses, particularly those stemming from prior MSIs. Effectively addressing these risk factors is pivotal for diminishing the rates of MSIs and attrition among recruits, thereby enhancing overall military readiness and operational efficiency. [ABSTRACT FROM AUTHOR]

Introduction United States Marine Corps' (USMC) recruit training is a 13-week program designed to maximize physical and mental performance adaptations. The purpose of this study was to evaluate the training demands and characteristics that are associated with performance outcomes during USMC recruit training. Materials and Methods A total of 196 recruits (M = 97 and W = 99) were monitored and tested throughout training. Laboratory-based performance testing occurred at the start of weeks 2 and 11 and consisted of body mass assessments, countermovement vertical jump, and isometric mid-thigh pull. Military-specific performance testing occurred twice within the first 8 weeks of training and included the physical fitness test (PFT) and combat fitness test (CFT) implemented by the USMC. Resilience data were collected at week 2 using the Connor-Davidson Resilience Scale. Workload, sleep, and stress responses were monitored at weeks 2, 7, and 11. Recruits were provided with a wearable tracking device which utilized heart rate and accelerometry-based technology to determine energy expenditure (EE), distances (DIS), and sleep metrics. Data were averaged over a 3-day period. Salivary cortisol testing occurred at the start of each monitoring week. Change scores were calculated for performance tests, and body mass was calculated from data obtained at week 2 to week 11. Area under the curve was calculated for the workload, sleep metrics, and cortisol responses using the trapezoidal method. Pearson product–moment correlations (r) were used to assess the relationships between training demands and performance. An α level of 0.05 was used to establish significance. Results A moderate positive correlation was found between changes in body mass and peak power (P  < .001; r  = 0.43). Weak positive correlations were found between changes in body mass and peak force (P  = .002; r  = 0.28), as well as body mass and resilience (P  = .03; r  = 0.19). A moderate negative correlation was observed between changes in body mass and PFT (P  < .001; r  = −0.49). A weak negative correlation was found between changes in body mass and EE (P  = .003; r  = −0.24). A weak negative correlation was found between changes in peak power and EE (P  = .001; r  = −0.29). A weak positive correlation was found between changes in peak power and changes in CFT (P  = .05; r  = 0.19) A weak negative correlation was found between changes in sleep continuity and CFT (P  = .02; r  = −0.20). A weak negative correlation was found between cortisol and changes in PFT (P  = .05; r  = −0.20). A weak negative correlation was found between cortisol and both EE (P  = .001; r  = −0.27) and DIS (P  = .045; r  = −0.16). A weak negative correlation was found between EE and sleep continuity (P  < .001; r  = −0.34). Weak negative correlations were found between sleep duration and both DIS (P  = .01; r  = −0.18) and steps (P  = .003; r  = −0.21). Conclusions Increases in body mass throughout training were positively associated with strength and power changes, but negatively related to PFT scores. Changes in peak power related to improvements in CFT scores; however, higher workloads (i.e. EE) were negatively associated with peak power. The identification of the USMC physical and physiological training demands that are associated with performance outcomes may be a valuable resource to guide conditioning efforts to boost military readiness. [ABSTRACT FROM AUTHOR]

Introduction Drill instructors (DIs) are responsible for executing their Services' recruit training programs and for training recruits. DIs assume a variety of roles, including teaching and developing practical skills and knowledge, mentoring, modeling appropriate behavior and attitudes, motivating recruits for success during and after recruit training, applying and instilling discipline, and ensuring the safety and welfare of recruits. This article examines two major research questions at the intersection of gender, gender-integrated training, and the DI role: (1) What differences exist in how DIs experience their role by gender? and (2) how does gender-integrated recruit training affect DIs' approach to training? Materials and Methods This article draws from 87 semistructured interviews conducted with Service leaders, training cadre, and DIs in service of a broader Marine Corps interdisciplinary study on gender integration at recruit training. Interviews were conducted virtually and in-person with Marine Corps, Army, Navy, Air Force, and Coast Guard personnel from June to November 2021. Each interview was coded with initial and secondary codes developed through a flexible coding approach. Data were analyzed across and within relevant categories such as gender and Service to identify themes and patterns. Results Although the DI role was universally described as demanding and difficult, unique challenges for women consistently emerged from the data. The top reported challenges faced by female DIs were personnel shortages, work and family conflict, culture-driven sexism in the training environment from male peers and recruits, and pressure to excel above and beyond their male peers. In recruit training, DIs are responsible for executing gender-integrated practices. Service leaders, training cadre, and DIs described how gender integration practices affect their approach to the role and implementation of training, including addressing and dismantling sexism, shutting down recruit romantic relationships, training all recruits in an equal manner, knowing gender-specific grooming standards, increasing communication among DIs, and working with mixed-gender DI teams. Conclusions Female DIs face additional challenges in and outside the role compared with their male peers, and some of these challenges are preventable. Staffing and personnel issues plague the female DI population and are a persistent and pervasive challenge to gender integration efforts. Women are a necessary and highly desirable population to fill the DI role, particularly as Services aim to expose recruits to leaders of both genders during their critical first training experience. DIs play an important role in ensuring the successful completion of recruit training, ultimately helping to build the future leaders of the military. The success of gender integration efforts depends on DIs' intentional approach to the process. Future research can build on this work by expanding the scope to other military training environments (beyond recruit training) and examining how DIs' own sociodemographic positions (e.g. gender, race, ethnicity, and sexual orientation) inform their perspective on and approach to equity in the training environment. [ABSTRACT FROM AUTHOR]

Introduction The U.S. Marine Corps (USMC) recruit training is a 13-week preparatory period for military service men and women. Differences in absolute performance capabilities between sexes may impact physical and physiological responses to the demands of recruit training. The purpose of this study was to monitor U.S. Marine Corps recruits throughout recruit training to comparatively assess workload, sleep, stress, and performance responses in men and women. Materials and Methods A total of 281 recruits (men = 182 and women = 99; age = 19 ± 2 years) were monitored and tested. Workload, sleep, and stress assessments occurred at week 2, week 7/8, and week 11 of training. Workload (energy expenditure per kg body mass [EEREL], distance [DIS], steps) and sleep (continuity and duration) were tracked over 72-hour periods using wearable accelerometry and heart rate technology. Stress responses were determined through salivary cortisol analyses. Performance testing, consisting of countermovement vertical jump (CMJ) and isometric mid-thigh pull (IMTP) performance relative to body mass, occurred at weeks 2 and 11. Linear mixed models were used to test for sex, time, and sex-by-time interactions (α < .05). Results On average, recruits covered 13.0 ± 2.7 km/day, expended 3,762 ± 765 calories/day, and slept 6.2 ± 1.1 hours/night. Sex-by-time interactions were found for DIS, steps, sleep duration, cortisol, and CMJREL performance (P  < .05). Planned contrasts revealed that men covered more DIS than women at week 7/8 (P  < .001). Women experienced greater step counts compared to men at week 11 (P  = .004). Women experienced no significant change in sleep duration (P  > .05), whereas men increased sleep duration from week 2 to week 7/8 (P  = .03). Women experienced greater sleep duration at week 2 (P  = .03) and week 11 (P  = .02) compared to men. Women exhibited higher cortisol levels than men at week 2 (P  < .001) and week 11 (P  < .001). Women experienced declines in cortisol at week 7 compared to week 2 (P  < .001). Men experienced no changes in cortisol response at any timepoint (P  > .05). Both sexes experienced declines in CMJREL from week 2 to week 11 (P  > .001). Sex main effects were observed for EEREL, DIS, CMJREL, and IMTPREL (P  < .05) with men experiencing greater overall workloads and producing greater strength and power metrics. Sex main effects were also found for sleep continuity and cortisol (P  < .05), for which men experienced lower values compared to women. Time main effects were observed for EEREL, DIS, steps, cortisol, CMJREL, and IMTPREL (P  < .05). Conclusions This study not only highlights the known sex differences between men and women but also sheds light on the different physical and physiological responses of each sex to military training. Interestingly, the greatest physical demands incurred earlier in the training cycle. Despite declining workloads, the stress response was maintained throughout the training, which may have implications for adaptation and performance. In addition, average sleep duration fell notably below recommendations for optimizing health and recovery. Effectively monitoring the demands and performance outcomes during recruit training is essential for determining individual fitness capabilities, as well as establishing the effectiveness of a training program. Individual performance assessments and adequately periodized workloads may help to optimize recruit training for both men and women. [ABSTRACT FROM AUTHOR]

Introduction Recruit training is the initial entry for enlisted personnel in the military. The Services execute gender-integrated recruit training differently. The U.S. Marine Corps (USMC) maintains same-gender platoons led by same-gender drill instructors in integrated companies; further integration occurs at select training events. The other Services train recruits in gender-integrated units with mixed-gender drill instructor teams. We examine recruits' experiences and perceptions of gender integration at recruit training, their desired level of integration, and preferences for increasing gender integration, comparing by Service and gender. Materials and Methods Recruit perspectives and experiences were captured in a 19-question survey (n = 632) and 90-min focus groups (n  = 260) near graduation from recruit training. Data were collected from June to November 2021. Because of the Coronavirus disease (COVID-19) pandemic restrictions, the Navy and Air Force were not conducting gender-integrated recruit training during data collection. Outcome variables were compared cross-Service by gender and within Service by gender using chi-squared tests or Fisher's exact tests, as appropriate; focus group data were analyzed using initial and secondary coding schemes. Three USMC training models, varied by level of integration, were also analyzed (Male-Only, Series Track, and Integrated Company). Results Significant gender differences across and within Service emerged in recruits' experience being trained by an opposite-gender instructor. Male recruits had significant differences by Service (P  < .001), and USMC female recruits reported being trained by male instructors more than their male peers by female instructors (Series Track P  = .002; Integrated Company P  < .001). In the focus groups, recruits described common differences with how men and women embodied being a drill instructor. Significant gender differences across (both male and female P  < .001) and within Service were reported for closeness of training with opposite-gender peers (Air Force P  = .028; U.S. Marine Corps (USMC) Integrated Company P  = .010; Army P  = .048), an expected finding given varied integration during data collection. Male and female recruits had significant differences by Service in their preference for integration at the lowest unit level (both male and female P  < .001), with those who experienced integrated training showing higher levels of endorsement. In the focus groups, recruits articulated benefits and challenges of gender-integrated recruit training. Significant gender differences across Service emerged in preferences for more integration in specific training activities. Within Service, female USMC Integrated Company recruits wanted more integration in tactical/field, physical fitness, and classroom training than their male peers (P  < .001 for all). In the focus groups, USMC recruits of both genders desired more integrated training events, particularly those involving combat and tactical skill development. Conclusions This study provided an opportunity to examine recruit perspectives on gender-integrated training. Services valuing opposite-gender instructor exposure in recruit training must ensure that male recruits are being taught and led by female instructors given disproportionate demographics. Recruits who experienced integrated training were more supportive of integration, indicating that this experience may increase their support for gender-integrated training units and environments. Today's recruits understand that they are entering gender-integrated working environments, and our results indicate that they expect recruit training to mirror that reality. [ABSTRACT FROM AUTHOR]

Introduction This article describes alternate models and policy recommendations created by an interdisciplinary team of researchers to increase gender integration at U.S. Marine Corps (USMC) recruit training. The USMC requested a study to analyze current approaches to gender integration at recruit training and provide alternate models that maximize integration, while continuing to train marines to established standards. USMC remains the only service that segregates recruits by gender at the lowest unit level (e.g. platoon) in recruit training and maintains gender-segregated drill instructor teams (i.e. same-gender teams train platoons of same-gender recruits). Materials and Methods A mixed-method, interdisciplinary approach was used to capture multiple perspectives and informed recommendations and alternate models for gender integration. The team studied select USMC, army, navy, air force, and coast guard recruit training locations, between June and November 2021. At each site, the team collected qualitative, quantitative, and administrative data as well as physical performance metrics and human performance outcomes. Study participants included recruits, drill instructors, training cadre, service leaders, and subject matter experts on gender integration in military services. Each alternate model was designed to maximize the feasibility of implementation within current USMC training conditions. Results The research team developed three alternate models and several policy recommendations. Alternate model 1 proposed a methodology for mixed-gender drill instructor teams within the Integrated Company model, USMC's current integrated training model. Alternate model 2 proposed an Integrated Company Plus model which increases the number and types of gender-integrated training events at or below the platoon level within the Integrated Company model. Alternate model 3 outlined an integrated platoon model where recruits fall out into integrated training platoons after their morning routine, with two options of varying integration based on USMC priorities for integration. The team also proposed a set of policy recommendations independent of the three alternate models to support current and future gender integration efforts at the Marine Corps Recruit Depots. Conclusions Gender-integrated military training has been shown to positively alter perceptions and evaluations of women in military settings over detrimental aspects developed by gender-segregated training. The study team recommended USMC train recruits in the Integrated Company model with mixed-gender drill instructor teams (alternate model 1) and integrate more training events following the priority tiers outlined in the Integrated Company plus model (alternate model 2). The combined execution of these two alternate models would provide USMC recruits increased exposure to direct, sustained training from opposite-gender drill instructors and deliver intentional training opportunities for male and female recruits to work together and interact in meaningful ways. The integrated platoon model (alternate model 3) would offer USMC recruits the most direct exposure to training and working with members of the opposite gender, but it requires substantial changes to current logistics, accountability, and training procedures. [ABSTRACT FROM AUTHOR]

Introduction Several challenges face the U.S. Marine Corps (USMC) and other services in their efforts to design recruit training to augment warfighter mobility and resilience in both male and female recruits as part of an integrated model. Strength and power underpin many of the physical competencies required to meet the occupational demands one might face in military. As the military considers adopting force plate technology to assess indices of strength and power, an opportunity presents itself for the use of machine learning on large datasets to deduce the relevance of variables related to performance and injury risk. The primary aim of this study was to determine whether cluster analysis on baseline strength and power data derived from countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) adequately partitions men and women entering recruit training into distinct performance clusters. The secondary aim of this study is then to assess the between-cluster frequencies of musculoskeletal injury (MSKI). Materials and Methods Five hundred and sixty-five males (n  = 386) and females (n  = 179) at the Marine Corps Recruit Depots located at Parris Island and San Diego were enrolled in the study. Recruits performed CMJ and IMTP tests at the onset of training. Injury data were collected via medical chart review. Combat fitness test (CFT) and physical fitness test (PFT) results were provided to the study team by the USMC. A k -means cluster analysis was performed on CMJ relative peak power, IMTP relative peak force, and dynamic strength index. Independent sample t -tests and Cohen's d effect sizes assessed between-cluster differences in CFT and PFT performance. Differences in cumulative incidence of lower extremity %MSKIs were analyzed using Fisher's exact test. Relative risk and 95% confidence intervals (CIs) were also calculated. Results The overall effects of cluster designation on CMJ and IMTP outcomes ranged from moderate (relative peak power: d  = −0.68, 95% CI, −0.85 to −0.51) to large (relative peak force: d  = −1.69, 95% CI, −1.88 to −1.49; dynamic strength index: d  = 1.20, 95% CI, 1.02-1.38), indicating acceptable k -means cluster partitioning. Independent sample t -tests revealed that both men and women in cluster 2 (C2) significantly outperformed those in cluster 1 (C1) in all events of the CFT and PFT (P  < .05). The overall and within-gender effect of cluster designation on both CFT and PFT performance ranged from small (d  > 0.2) to moderate (d  > 0.5). Men in C2, the high-performing cluster, demonstrated a significantly lower incidence of ankle MSKI (P  = .04, RR = 0.2, 95% CI, 0.1-1.0). No other between-cluster differences in MSKI were statistically significant. Conclusions Our results indicate that strength and power metrics derived from force plate tests effectively partition USMC male and female recruits into distinct performance clusters with relevance to tactical and physical fitness using k -means clustering. These data support the potential for expanded use of force plates in assessing readiness in a cohort of men and women entering USMC recruit training. The ability to pre-emptively identify high and low performers in the CFT and PFT can aid in leadership developing frameworks for tailoring training to enhance combat and physical fitness with benchmark values of strength and power. [ABSTRACT FROM AUTHOR]

Glass fiber-reinforced plastics (GFRPs) have been widely used in marine structures, recently. In this paper, the water absorption and compressive behaviour of pultruded fiber-reinforced plastic pipes (GFRPs) after immersion in Caspian sea water and distilled water for 1, 7, 14, 21, 28, 35, and 40 days is experimentally investigated. In this respect, the specimens are submerged in Caspian seawater and distilled water and then their water absorption rate, length, and their compressive strength were measured every day. The compressive mechanical properties of the specimens in the as-received and water-aged states are obtained using quasi-static compression tests. The amount of water absorption and length change due to immersion in these two cases have also been investigated. After 40 days, the average relative humidity absorption of the samples in Caspian Sea water and distilled water were 2.88% and 2.89%, respectively. It was observed that after immersion in both Caspian Sea water and distilled water, the final compressive strength and absorbed energy of the pultruded pipes increased. [ABSTRACT FROM AUTHOR]

George Diacont was the first Director of Registration and Inspections for the Public Company Accounting Oversight Board (PCAOB). Diacont joined the PCAOB in March 2003, shortly after it commenced operations. His approach was to build a team of highly skilled professionals and encourage them to contribute their best ideas. His leadership style was to support his team, listen to their ideas, and make the best decisions possible without concern for praise or recognition. He also worked to instill a "regulatory attitude" in the former auditors who had become inspectors. This paper describes Diacont's long and distinguished career in government service beginning with his military service in the U.S. Marine Corps. He spent 24 years at the Securities and Exchange Commission and five years in the Listing Investigation group at the NASDAQ stock market. He served nearly eight years at the PCAOB before he retired in 2011. JEL Classifications: M4. [ABSTRACT FROM AUTHOR]

When a US Marine Corps training facility decided to add a second aquifer to its existing groundwater supply, it designed a treatment plant that would successfully blend the two source waters and meet strict water quality goals. [ABSTRACT FROM AUTHOR]

The study examines specific aspects of organizational performance within the Indonesian Navy (TNI AL), with a particular focus on the Marine Corps, essential for safeguarding Indonesia's maritime sovereignty. Utilizing quantitative methods and a survey approach, data was gathered from middle officers serving across 11 Marine Corps units over the past 5 years. Findings indicate that strategic leadership style, career development, and strategic competence of human resources significantly influence organizational performance within the Marine Corps. These factors, alongside organizational culture, are pivotal in shaping and sustaining performance levels. Importantly, the research underscores the importance of understanding these dynamics for Marine Corps management to enhance performance and achieve long-term objectives, particularly in navigating the complexities of globalization. Additionally, while rooted in the context of the Indonesian Navy, the implications of these findings extend to broader organizational settings, highlighting their potential applicability beyond the specific context of the TNI AL and Marine Corps. [ABSTRACT FROM AUTHOR]

Introduction Since the start of the Global War on Terrorism, exponential demands have been put on military personnel, their families, and the military health care system. In response to a Department of Defense Task Force on Mental Health, the U.S. military began developing and fielding programs to promote the psychological health of its personnel. As part of these initiatives, the Navy and Marine Corps developed the Stress Continuum model. The Stress Continuum is a stress classification system ("ready," "reacting," "injured," and "ill") that provides a common language for identifying, engaging, and intervening when stress reactions or stress injuries are present in military personnel. It is the foundation for resilience and prevention efforts across the Navy and Marine Corps. Although the Stress Continuum has strong face validity, is consistent with current theory, and has been agreed up by expert consensus, it has yet to be empirically validated. The goal of the current article is to begin to empirically validate the Stress Continuum using validated measures of psychological stress. Materials and Methods We conducted a retrospective analysis of Stress Continuum data (n  = 2,049) collected as part of a program evaluation of two Navy operational stress control programs. Receiver operating characteristic (ROC) curves and analyses were conducted to determine the classification quality of the Stress Continuum using a validated measure of stress (a brief version of the Perceived Stress Scale [PSS-4]). Results For the first ROC curve, we used the "ill" category (vs. the other three categories) to identify the cut point on the PSS-4. PSS-4 cut point values of 9 and 10, respectively, maximized sensitivity and 1-specificity values. Using the chi-square test, we further found that a more accurate prediction for those in the "ill" category was using the cut point of 9 (79%) relative to 10 (71.8%). For the second and the third ROC curves, we used the "ill" and "injured" categories (vs. the other two categories) and "ill," "injured," and "reacting" categories (vs. the "ready" category), respectively. No optimal cut points on the PSS-4 were identified for these models, indicating that the PSS-4 could not reliably differentiate true-positive and false-positive rates. Conclusions We found that the "ill" category of the Stress Continuum was predictive of higher levels of stress on the validated measure of perceived stress. Thus, our findings strongly suggest that the individuals in the "ill" zone likely warrant some type of intervention by a trained professional. Future Research The Navy has recently leveraged the Stress Continuum to create the Stress-o-Meter to support the fundamental principles of early recognition, peer intervention, and connection to services at the unit level. The Stress-o-Meter serves as a prevention tool that has the capability to collect information about stress levels throughout the entire unit at any time. Continued work on validating the Stress Continuum model and making it easily accessible to military units will ensure service members get the support they need and leaders are able to address the psychological health of their units. [ABSTRACT FROM AUTHOR]

This article discusses the life and contributions of Earl "Pete" Hancock Ellis, a Marine Corps officer who played a significant role in shaping the Marine Corps' mission and doctrine in the early 20th century. Ellis advocated for advanced base operations and amphibious assault missions, which were eventually embraced by the Navy and Marine Corps. His ideas were outlined in a document called "Advanced Base Operations in Micronesia," and he emphasized the need for specialized training in water and jungle warfare. While Ellis's contributions are acknowledged, the article emphasizes the collective effort and the role of other influential figures in shaping the Marine Corps' mission. [Extracted from the article]