United States Marine Corps

Abstract Post-Traumatic Stress Disorder (PTSD) is prevalent among both the civilian and military populace, causes significant burden to the healthcare system, and diminishes the quality of life of those afflicted by it. Secondary pharmacologic prevention strategies with glucocorticoids have been studied in ICU patients and those who have experienced traumatic events with some effect. This case report follows one Active-Duty Marine who was exposed to a traumatic event during an emergency medical technician shift. Following this event, he was diagnosed with Acute Stress Reaction and treated with a 10-day course and follow-on taper of oral hydrocortisone. During follow up appointments the patient symptomatically improved, returned to work without limitations, and never met criteria for PTSD. This case report provides further support for the use of hydrocortisone as secondary pharmacologic prevention of PTSD in select cases and highlights the need for increased research into the topic, especially in the military population.

Abstract A better understanding of recruitment mechanisms in fishes is a high priority for operational management, as it can improve both stock assessment models and impact assessments, given that early life stages are particularly sensitive to changes in the environment. The impacts from anthropogenic pressures, including climate change, can be especially severe in extreme environments, where fish are already living close to their physiological limits. In the brackish Baltic Sea, Atlantic cod (Gadus morhua L.) exhibits unique adaptations to the low salinity, but suffers from long-term overexploitation and a loss of spawning areas due to climate change and eutrophication. At the northern edge of its distribution range, in the Åland Sea (ICES subdivision (SD) 29N), a healthy stock component continues to thrive, despite living in an extreme low-salinity environment. Here, we study recruitment mechanisms of this stock component, to understand where cod in the area reproduces. Cod collected by commercial gillnet fishers at 220-250 m depth in May-June 2019 had a mean weight of 2.6 kg and were all in spawning condition. Laboratory experiments showed that fertilisation and egg development was not successful at a salinity corresponding to the Åland Sea (7.5 psu), but to some extent at 9 and 10 psu. Hydrographical modelling suggests that, in addition to known spawning areas further south, conditions in the northern Baltic Proper (SD 27, 29S and 32) may occasionally be suitable for reproduction. Larval drift models show that these areas are highly connected to the Åland Sea and may be important for recruitment, although larvae can also drift in from known spawning areas in the Gdansk and Gotland Basins (SD 26 and 28). To fully understand the recruitment mechanisms, further studies on the migratory behaviour, genetic population structure, and occurrence of eggs and larvae are needed.

This study explores the factors that influence the cohesion of military groups and develops a scale for measuring the current state of group cohesion in the military. The importance of military unity has always been a significant factor in victory in war, and group cohesion plays a pivotal role in the success or failure of military operations. The research is divided into two phases: the first phase includes a literature review, in-depth interviews, and focus group discussions to gather information about the connotations of military group cohesion. The interviews revealed that the elements of military group cohesion encompass five dimensions: cooperation, communication, leadership, commitment, and the external environment. In the second phase, based on data obtained from the interviews, a military group cohesion questionnaire was developed, and 214 personnel from grassroots units were tested to assess the reliability and validity of the scale. The results indicate that better performance correlates with higher group cohesion. The findings of this study can serve as a reference for relevant units when formulating policies.

Elasmobranchs often exhibit nocturnal or crepuscular activity, with shark diel patterns being better understood than ray diel patterns. We used accelerometry and hidden Markov models (HMMs) to classify female southern stingray ( Hypanus americanus Hildebrand & Schroeder, 1928) activity states across diel periods and environmental conditions in Belize. Three state (low, medium, and high activity) HMMs were constructed for all individuals together and separately ( N = 9). Combined, stingrays were most likely to be highly active at night and in low and medium activity states in the morning. However, there was individual variation in diel activity. In contrast, all stingrays consistently used shallow water (<4 m) during periods of high activity. Temperature had less influence on activity patterns, although three individuals exhibited high activity in cooler water. Generally, high stingray activity was driven by diel cycles and depth. Future research should link activity states to specific behaviours, include a larger sample size, extend tag deployment durations, and explore the impact of predator and prey dynamics on stingray activity.

Given diverse symptom expression and high rates of comorbid conditions, the present study explored underlying commonalities among OCD-affected children and adolescents to better conceptualize disorder presentation and associated features. Data from 830 OCD-affected participants presenting to OCD specialty centers was aggregated. Dependent mixture modeling was used to examine latent clusters based on their age- and gender adjusted symptom severity (as measured by the Children's Yale-Brown Obsessive-Compulsive Scale; CY-BOCS), symptom type (as measured by factor scores calculated from the CY-BOCS symptom checklist), and comorbid diagnoses (as assessed via diagnostic interviews). Fit statistics favored a four-cluster model with groups distinguished primarily by symptom expression and comorbidity type. Fit indices for 3-7 cluster models were only marginally different and characteristics of the clusters remained largely stable between solutions with small clusters of distinct presentations added in more complex models. Rather than identifying a single classification system, the findings support the utility of integrating dimensional, developmental, and transdiagnostic information in the conceptualization of OCD-affected children and adolescents. Identified clusters point to the centrality of contamination concerns to OCD, relationships between broader symptom expression and higher levels of comorbidity, and the potential for complex/neurodevelopmental presentations.

The average day-to-day nursing profession is a stressful one. The job often requires dealing with patients enduring some of the worst times of their lives, as well as contending with patients' emotional family members. This stressful environment is heightened even more for nurses employed in critical access hospitals (CAHs) due to the limited resources usually associated with these smaller facilities. Methods: Research and Evidence-Based Practice Council members at one CAH explored how to help nurses deal with the elevated work stress level. Aromatherapy tabs were used as an intervention to reduce nurses' stress. The nurses who participated in this pilot study took a short survey before starting their shifts, indicating their stress levels. Following the survey, scented aromatherapy tabs were attached to the nurses' uniforms and worn for the entirety of their shifts. At the end of their shifts, the participating nurses completed the same stress survey. Results: Twenty-five nurses participated in the pilot study. Nurses who did not wear the aromatherapy tab reported higher stress levels at the end of the shift than at the start, with a 3% overall average increase. Nurses who wore the aromatherapy tab reported lower stress levels at the end of the shift with a 12% overall average decrease. Discussion: Using aromatherapy tabs positively impacted nurses' reported stress levels, indicating that aromatherapy tabs can be a tool for nurses to utilize within the workplace, supporting the need for further research.

Previous research has identified significant performance gaps between Marine Raider Operators (MRO) and Combat Support Personnel (CSP), often recommending additional training to improve performance, such as running. Running is a common mechanism for injury; therefore, it is important to examine mechanics and loading patterns during running in order to improve program efficacy while reducing the risk of injury. PURPOSE: Compare performance and impact patterns between MRO and CSP during a rapid maximal effort running assessment. METHODS: 81 MROs and 73 CSP performed a maximal effort 5-minute run on a non-motorized treadmill. Impacts were measured using inertial measurement units placed bilaterally on the tibia. Independent sample t-tests (α = 0.05) were used to compare group means for total distance and impact variables (Table 1). Pearson correlation coefficients were used to examine the relationships between distance and impact variables. RESULTS: MRO ran a significantly greater Distance (p < 0.001) and had a greater Step Count (p = 0.001) compared to CSP. There were no differences in the impact variables (p > 0.05). There was a moderate correlation between Distance and Total Step Count (r = 0.409, p < 0.01). Table 1. Descriptive statistics of performance and impact variables. * = significant difference, p < 0.05 - Distance (yd)* Impact Load Total (L + R) Average Intensity (L + R) Impact Asymmetry Absolute Value Step Count Total (L + R)* Step Count Total by Intensity - Low 1 g-5 g (L + R) Step Count Total by Intensity - Medium 6 g-20 g (L + R) Step Count Total by Intensity - High 21 g-200 g + (L + R) Operators (MRO) 875.89 ± 78.96 7912.85 ± 2704.37 9.31 ± 3.03 7.42 ± 5.99 846.57 ± 41.78 185.57 ± 194.22 647.52 ± 207.09 13.48 ± 53.52 Support (CSP) 783.14 ± 88.87 7694.80 ± 2561.97 9.31 ± 3.07 7.95 ± 6.08 825.18 ± 34.02 194.58 ± 176.95 610.71 ± 185.74 19.89 ± 60.79 CONCLUSION: During a 5-minute run, MRO ran further by taking more steps, not by increasing the intensity of each step. These results may be influenced by a combination of aerobic capacity, muscle endurance, strength, and running mechanics. Training these aspects of performance may help CSP improve their running distance by increasing their step rate. Monitoring any corresponding changes to impacts or mechanics using wearable technology may help minimize injury risk. DISCLAIMER: This research was supported by the Office of Naval Research N00014-18-C-2025. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Office of Naval Research or the US Navy.