Trilobite tridents demonstrate sexual combat at 400 Mya.

The Devonian trilobite Walliserops carries a remarkable anterior cephalic trident posing a challenge to functional interpretation. A unique teratological specimen of Walliserops trifurcatus showing four, rather than three tines, is inconsistent with possible hypotheses connecting the trident to feeding techniques and suggests a sexually selected function. Malformations in a variety of living organisms support this conclusion. Morphometric comparisons to similar structures used for intraspecific combat in dynastine beetles show that the trident occupies a comparable shape space consistent with the hypothesis that it was a sexual combat weapon, the oldest reported example of its kind. This lends further credibility to the idea that some trilobites may have been strongly sexually dimorphic.

Overcoming the impacts of two-step batch effect correction on gene expression estimation and inference.

Nonignorable technical variation is commonly observed across data from multiple experimental runs, platforms, or studies. These so-called batch effects can lead to difficulty in merging data from multiple sources, as they can severely bias the outcome of the analysis. Many groups have developed approaches for removing batch effects from data, usually by accommodating batch variables into the analysis (one-step correction) or by preprocessing the data prior to the formal or final analysis (two-step correction). One-step correction is often desirable due it its simplicity, but its flexibility is limited and it can be difficult to include batch variables uniformly when an analysis has multiple stages. Two-step correction allows for richer models of batch mean and variance. However, prior investigation has indicated that two-step correction can lead to incorrect statistical inference in downstream analysis. Generally speaking, two-step approaches introduce a correlation structure in the corrected data, which, if ignored, may lead to either exaggerated or diminished significance in downstream applications such as differential expression analysis. Here, we provide more intuitive and more formal evaluations of the impacts of two-step batch correction compared to existing literature. We demonstrate that the undesired impacts of two-step correction (exaggerated or diminished significance) depend on both the nature of the study design and the batch effects. We also provide strategies for overcoming these negative impacts in downstream analyses using the estimated correlation matrix of the corrected data. We compare the results of our proposed workflow with the results from other published one-step and two-step methods and show that our methods lead to more consistent false discovery controls and power of detection across a variety of batch effect scenarios. Software for our method is available through GitHub (https://github.com/jtleek/sva-devel) and will be available in future versions of the $\texttt{sva}$ R package in the Bioconductor project (https://bioconductor.org/packages/release/bioc/html/sva.html).

Sexually selected weapons can wear out, decreasing their effectiveness in combat.

Sexual selection has resulted in some of the most elaborate traits seen in animals, many of which are used as weapons. These weapons can be incredibly diverse, even within species. Such morphological variation has largely been attributed to the environment in which individuals are reared and their genetics. However, variation in weapon form could also be the result of a weapon wearing out from usage. This mechanism has received relatively little attention. In this study, we demonstrate that sexually selected weapons can wear out from repeated use, providing experimental evidence that weapon usage can contribute to the diversity of weapon shapes observed within species. In a second experiment, we demonstrate that having a worn-out weapon decreases an individual's fighting ability. This finding illustrates that the shape of a weapon can have an important role in determining contest outcomes. Overall, these results suggest that individuals are limited in the number of times they can effectively use their weapons, which may be one factor (among others) influencing how frequently an animal engages in a fight.

The military gear microbiome: risk factors surrounding the warfighter.

Combat extremity wounds are highly susceptible to contamination from surrounding environmental material. This bioburden could be partially transferred from materials in immediate proximity to the wound, including fragments of the uniform and gear. However, the assessment of the microbial bioburden present on military gear during operational conditions of deployment or training is relatively unexplored. Opportunistic pathogens that can survive on gear represent risk factors for infection following injury, especially following combat blasts, where fibers and other materials are embedded in wounded tissue. We utilized 16S rRNA sequencing to assess the microbiome composition of different military gear types (boot, trouser, coat, and canteen) from two operational environments (training in Hawai'i and deployed in Indonesia) across time (days 0 and 14). We found that microbiome diversity, stability, and composition were dependent on gear type, training location, and sampling timepoint. At day 14, species diversity was significantly higher in Hawai'i samples compared to Indonesia samples for boot, coat, and trouser swabs. In addition, we observed the presence of potential microbial risk factors, as opportunistic pathogenic species, such as Acinetobacter, Pseudomonas, and Staphylococcus, were found to be present in all sample types and in both study sites. These study outcomes will be used to guide the design of antimicrobial materials and uniforms and for infection control efforts following combat blasts and other injuries, thereby improving treatment guidance during military training and deployment.IMPORTANCECombat extremity wounds are vulnerable to contamination from environments of proximity to the warfighter, leading to potential detrimental outcomes such as infection and delayed wound healing. Therefore, microbial surveillance of such environments is necessary to aid the advancement of military safety and preparedness through clinical diagnostics, treatment protocols, and uniform material design.

Blood consumption in the Role 2 setting: A Department of Defense Trauma Registry analysis.

BACKGROUND: The Role 2 setting represents the most far-forward military treatment facility with limited surgical and holding capabilities. There are limited data to guide recommendations on blood product utilization at the Role 2. We describe the consumption of blood products in this setting. STUDY DESIGN AND METHODS: We analyzed data from 2007 to 2023 from the Department of Defense Trauma Registry (DODTR) that received care at a Role 2. We used descriptive and inferential statistics to characterize the volumes of blood products consumed in this setting. We also performed a secondary analysis of US military, Coalition, and US contractor personnel. RESULTS: Within our initial cohort analysis of 15,581 encounters, 17% (2636) received at least one unit of PRBCs or whole blood, of which 11% received a submassive transfusion, 4% received a massive transfusion, and 1% received a supermassive transfusion. There were 6402 encounters that met inclusion for our secondary analysis. With this group, 5% received a submassive transfusion, 2% received a massive transfusion, and 1% received a supermassive transfusion. CONCLUSIONS: We described volumes of blood products consumed at the Role 2 during recent conflicts. The maximum number of units consumed among survivors exceeds currently recommended available blood supply. Our findings suggest that rapid resupply and cold-stored chain demands may be higher than anticipated in future conflicts.

The employment of resuscitative endovascular balloon occlusion of the aorta in deployed settings.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been often used in place of open aortic occlusion for management of hemorrhagic shock in trauma. There is a paucity of data evaluating REBOA usage in military settings. STUDY DESIGN AND METHODS: We queried the Department of Defense Trauma Registry (DODTR) for all cases with at least one intervention or assessment available within the first 72 h after injury between 2007 and 2023. We used relevant procedural codes to identify the use of REBOA within the DODTR, and we used descriptive statistics to characterize its use. RESULTS: We identified 17 cases of REBOA placed in combat settings from 2017 to 2019. The majority of these were placed in the operating room (76%) and in civilian patients (70%). A penetrating mechanism caused the injury in 94% of cases with predominantly the abdomen and extremities having serious injuries. All patients subsequently underwent an exploratory laparotomy after REBOA placement, with moderate numbers of patients having spleen, liver, and small bowel injuries. The majority (82%) of included patients survived to hospital discharge. DISCUSSION: We describe 17 cases of REBOA within the DODTR from 2007 to 2023, adding to the limited documentation of patients undergoing REBOA in military settings. We identified patterns of injury in line with previous studies of patients undergoing REBOA in military settings. In this small sample of military casualties, we observed a high survival rate.

A prospective, pragmatic non-inferiority study of emergency intubation success with the single-use i-view versus standard reusable video laryngoscope.

INTRODUCTION: Video laryngoscope (VL) technology improves first-pass success. The novel i-view VL device is inexpensive and disposable. We sought to determine the first-pass intubation success with the i-view VL device versus the standard reusable VL systems in routine use at each site. METHODS: We performed a prospective, pragmatic study at two major emergency departments (EDs) when VL was used. We rotated i-view versus reusable VL as the preferred device of the month based on an a priori schedule. An investigator-initiated interim analysis was performed. Our primary outcome was a first-pass success with a non-inferiority margin of 10% based on the per-protocol analysis. RESULTS: There were 93 intubations using the reusable VL devices and 81 intubations using the i-view. Our study was stopped early due to futility in reaching our predetermined non-inferiority margin. Operator and patient characteristics were similar between the two groups. The first-pass success rate for the i-view group was 69.1% compared to 84.3% for the reusable VL group. A non-inferiority analysis indicated that the difference (-15.1%) and corresponding 90% confidence limits (-25.3% to -5.0%) did not fall within the predetermined 10% non-inferiority margin. CONCLUSIONS: The i-view device failed to meet our predetermined non-inferiority margin when compared to the reusable VL systems with the study stopping early due to futility. Significant crossover occurred at the discretion of the intubating operator during the i-view month.

Drawing and storing blood using a 3D printed bottle cap and a disinfected 500 mL drinking bottle: A proof-of-concept study.

BACKGROUND: Today, with wars raging in Ukraine and the Middle East, the demand for blood is high. Despite this, few companies produce the necessary equipment to draw, store, and transfuse whole blood. This study evaluated the safety and performance of a 3D printed bottle cap in conjunction with a water bottle and some available consumables to draw and store fresh whole blood. STUDY DESIGN AND METHODS: Bags of saline, and freshly donated whole blood, was transferred to the water bottle through a 3D printed bottle cap and stored for 72 h. An identical setup, transferring saline to a Terumo blood collection bag was used as control. Performance and safety were evaluated by calculating infusion rate and observing for backflow, respectively. The blood was also tested for hemolysis and bacterial growth at four sampling points. RESULTS: The cap-and-bottle setup was faster than control in terms of flow rate when transferring saline (1.53 vs. 1.81 mL/s, p < .001), and non-inferior to saline control when transfusing blood (1.53 vs. 1.49 mL/s, p = .641). We did not observe any risks of causing the donor iatrogenic harm, and there was no evidence of increased hemolysis. However, there were traces of bacterial contamination in three of six bottles. CONCLUSION: This study indicates that drawing blood is both feasible and safe, utilizing a 3D printed cap and bottle setup. Flow rate was faster than control, and mechanical properties of the blood were not affected. We were unable to determine the source of bacterial contamination in the blood.

Effectiveness of Mobile Applications for Trauma Care in Combat Casualty Simulations Throughout the Continuum.

INTRODUCTION: The U.S. Military uses handwritten documentation throughout the continuum of combat casualty care to document from point-of-injury, during transport and at facilities that provide damage control resuscitation and surgery. Proven impractical due to lack of durability and legibility in arduous tactical environments, we hypothesized that mobile applications would increase accuracy and completeness of documentation in combat casualty simulations. METHODS: We conducted simulations across this continuum utilizing 10 two-person teams consisting of a Medic and an Emergency or Critical Care Nurse. Participants were randomized to either the paper group or BATDOK and T6 Health Systems mobile application group. Simulations were completed in both the classroom and simulated field environments. All documentation was assessed for speed, completeness, and accuracy. RESULTS: Participant demographics averaged 10.8 ± 5.2 y of military service and 3.9 ± 0.6 h of training on both platforms. Classroom testing showed a significant increase in completeness (84.2 ± 8.1% versus 77.2 ± 6.9%; P = 0.02) and accuracy (77.6 ± 8.1% versus 68.9 ± 7.5%; P = 0.01) for mobile applications versus paper with no significant difference in overall time to completion (P = 0.19). Field testing again showed a significant increase in completeness (91.6 ± 5.8 % versus 70.0 ± 14.1%; P < 0.01) and accuracy (87.7 ± 7.6% versus 64.1 ± 14.4%; P < 0.01) with no significant difference in overall time to completion (P = 0.44). CONCLUSIONS: In deployed environments, mobile applications have the potential to improve casualty care documentation completeness and accuracy with minimal additional training. These efforts will assist in meeting an urgent operational need to enable our providers.

Impact of the 4th of August Beirut explosion mass casualty incident on a university hospital microbial Flora.

BACKGROUND: Following the Beirut explosion, our university hospital received at least 350 casualties. Subsequently, infection control standard practices were compromised. Concerns for Multi-Drug Resistant Organisms (MDROs) infections in injured patients and a resulting hospital outbreak were raised. The objectives of the study were to compare the rate of hospital growing MDROs 6 months before and 6 months after the Beirut explosion, to identify emerging microorganisms and to evaluate the change in surgical infection prevention practices. METHODS: This is a retrospective chart review of patients with hospital acquired infections (HAI) admitted to the hospital before and after the Beirut explosion. The study was conducted between February 4, 2020 and January 4, 2021. Excluded patients were those transferred from other hospitals and those with community acquired infections. The primary outcome was to identify the rate of growing MDROs post explosion. The secondary outcomes were identifying antibiotics used for surgical prophylaxis in patients requiring surgeries and patients diagnosed with a HAI. Therefore, patients were divided in three groups. Control group included patients admitted with explosion-related injuries on that same day. Patients admitted and between February 4 and August 4 and diagnosed with HAI were compared to those admitted post August 4 with explosion-related HAI and to patients diagnosed with non-explosion-related HAI between August 4 and January 4, 2021. An estimated rate of 18-22% MDRO was needed to achieve a statistical significance with 80% power and 0.05 α. Pearson Chi square test was used to analyze the primary outcome. RESULTS: A total of 82 patients with 150 cultures were included in this study. Data showed an increase in the rate of MDRO after the explosion with 37.1% of the cultures taken before the explosion and 53.1% after the explosion (p = 0.05). When comparing the types of HAI in both groups, culture sites were significantly different between pre- and post-explosion patients (p = 0.013). However, both groups had similar types of microbes (p = 0.996) with an increase in candida related infections. CONCLUSION: These findings confirmed that the Beirut explosion impact on antimicrobial resistance was similar to combat zone incidence, where an increase in MDROs rate such as Escherichia coli (E.Coli) and Stenotrophomonas maltophilia, in addition to the increase in candida related infections.

The effect of combat deployments on veteran opioid abuse.

Grim national statistics about the U.S. opioid crisis are increasingly well known to the American public. Far less well known is that U.S. servicemembers are at ground zero of the epidemic, with veterans facing an overdose death rate of up to twice that of civilians. Exploiting a quasi-experiment in overseas deployment assignment, this study estimates the causal impact of combat exposure among the deployed in the Global War on Terrorism on opioid abuse. We find that exposure to war theater substantially increased the risk of prescription painkiller abuse and illicit heroin use among active duty servicemen. The magnitudes of our estimates imply lower-bound combat exposure-induced healthcare costs of $1.04 billion per year for prescription painkiller abuse and $470 million per year for heroin use.

The impact of the combat method on radiomics feature compensation and analysis of scanners from different manufacturers.

BACKGROUND: This study investigated whether the Combat compensation method can remove the variability of radiomic features extracted from different scanners, while also examining its impact on the subsequent predictive performance of machine learning models. MATERIALS AND METHODS: 135 CT images of Credence Cartridge Radiomic phantoms were collected and screened from three scanners manufactured by Siemens, Philips, and GE. 100 radiomic features were extracted and 20 radiomic features were screened according to the Lasso regression method. The radiomic features extracted from the rubber and resin-filled regions in the cartridges were labeled into different categories for evaluating the performance of the machine learning model. Radiomics features were divided into three groups based on the different scanner manufacturers. The radiomic features were randomly divided into training and test sets with a ratio of 8:2. Five machine learning models (lasso, logistic regression, random forest, support vector machine, neural network) were employed to evaluate the impact of Combat on radiomic features. The variability among radiomic features were assessed using analysis of variance (ANOVA) and principal component analysis (PCA). Accuracy, precision, recall, and area under the receiver curve (AUC) were used as evaluation metrics for model classification. RESULTS: The principal component and ANOVA analysis results show that the variability of different scanner manufacturers in radiomic features was removed (P˃0.05). After harmonization with the Combat algorithm, the distributions of radiomic features were aligned in terms of location and scale. The performance of machine learning models for classification improved, with the Random Forest model showing the most significant enhancement. The AUC value increased from 0.88 to 0.92. CONCLUSIONS: The Combat algorithm has reduced variability in radiomic features from different scanners. In the phantom CT dataset, it appears that the machine learning model's classification performance may have improved after Combat harmonization. However, further investigation and validation are required to fully comprehend Combat's impact on radiomic features in medical imaging.

Interventions associated with survival after prehospital intubation in the deployed combat setting.

INTRODUCTION: Airway compromise is the second leading cause of potentially preventable death on the battlefield. Prehospital airway management is often unavoidable in a kinetic combat environment and expected to increase in future wars where timely evacuation will be unreliable and air superiority not guaranteed. We compared characteristics of survivors to non-survivors among combat casualties undergoing prehospital airway intubation. MATERIALS AND METHODS: We requested all Department of Defense Trauma Registry (DODTR) encounters during 2007-2023 with documentation of any airway intervention or assessment within the first 72-h after injury. We conducted a retrospective cohort study of all casualties with intubation documented in the prehospital setting. We used descriptive and inferential statistical analysis to compare survivors through 7 days post injury versus non-survivors. We constructed 3 multivariable logistic regression models to test for associations between interventions and 7-day survival after adjusting for injury severity score, mechanism of injury, and receipt of sedatives, paralytics, and blood products. RESULTS: There were 1377 of 48,301 patients with documentation of prehospital intubation in a combat setting. Of these, 1028 (75%) survived through 7 days post injury. Higher proportions of survivors received ketamine, paralytic agents, parenteral opioids, and parenteral benzodiazepines; there was no difference in the proportions of survivors versus non-survivors receiving etomidate. The multivariable models consistently demonstrated positive associations between 7-day survival and receipt of non-depolarizing paralytics and opioid analgesics. CONCLUSIONS: We found an association between non-depolarizing paralytic and opioid receipt with 7-day survival among patients undergoing prehospital intubation. The literature would benefit from future multi-center randomized controlled trials to establish optimal pharmacologic strategies for trauma patients undergoing prehospital intubation.

Methemoglobinemia screening and treatment in tank warfare survivors.

INTRODUCTION: Methemoglobinemia, characterized by the conversion of functional hemoglobin to methemoglobin, can significantly impede tissue oxygenation. Prompt diagnosis and treatment of methemoglobinemia are critical to optimizing clinical outcomes. Although the underlying etiology of methemoglobinemia is often attributed to a medication reaction or chemical exposure, its association with battlefield trauma remains underexplored. This case series explores the presence of methemoglobinemia in nine soldiers evacuated from tanks targeted by explosives, shedding new light on screening needs and treatment strategies. CASES DESCRIPTION: Nine combat trauma patients with methemoglobinemia were admitted to Soroka Medical Center over a two-month period. Detailed case descriptions illustrate the diverse presentations and treatment responses. Notably, the administration of methylene blue resulted in rapid methemoglobin reductions and an improvement in oxygenation without any observed side effects. DISCUSSION: This series highlights an unexpected consequence of an explosion within an armored fighting vehicle and the challenges related to standard pulse oximetry interpretation and accuracy in the presence of methemoglobinemia, emphasizing the need for vigilant monitoring and co-oximetry utilization. Additionally, the coexistence of carboxyhemoglobin further warrants attention due to its synergistic and deleterious effects on oxygen delivery. Collaborative efforts with military authorities should aim to explore the underlying mechanisms associated with trauma and methemoglobinemia and optimize battlefield care. CONCLUSION: This case series underscores the significance of methemoglobinemia screening in combat trauma patients, and advocates for systematic co-oximetry utilization and methylene blue availability in combat zones. Early detection and intervention of methemoglobinemia in combat soldiers are often difficult in the context of battlefield injuries but are necessary to mitigate the potentially fatal consequences of this condition.

Association of second-hand smoking with sleep quality among adults in Ibadan, Nigeria: a cross-sectional evaluation of data from the COMBAT-CVDs study.

PURPOSE: Sleep quality (SQ) is essential in the overall well-being and quality of life, but little is known about the association of secondhand smoking (SHS) with SQ. This study assessed the relationship between SHS and SQ among adults who had never smoked in Ibadan, Nigeria. METHODS: We identified 3193 respondents who had never smoked or used any form of tobacco product in the Community-based Investigation of the Risk Factors for Cardiovascular Diseases in the Ibadan and suburbs (COMBAT-CVDs) study. SHS was self-reported, SQ assessed using a sleep quality scale, and SQ scores were classified by the quartile distributions of SQ scores in this sample as good (< 7), moderate (7-13), fair (14-20), and poor (≥ 21), and logistic regression models were used to estimate the multivariable-adjusted odds ratio and 95% confidence interval (CI) of the association between SHS and SQ in a two-sided test at P < 0.05. RESULTS: The mean (SD) of age in this sample was 34.8 ± 15.1 years; 1621 (50.8%) were females, and 848 (26.6%) experienced SHS. The multivariable-adjusted odds by categories of SQ scores (using good SQ as reference) in the light of SHS were OR: 1.64 (95%CI 1.28, 2.12) for moderate SQ, OR: 1.88 (95%CI 1.46, 2.42) for fair SQ and OR: 2.14 (95%CI 1.66, 2.75) for poor SQ; P < 0.0001 after adjusting for relevant covariates. The sex- and age groups- stratified analyses revealed similar trends. CONCLUSION: SHS is associated with higher odds of poor SQ in this study. Culturally relevant interventions for mitigating exposure to SHS might improve SQ and overall quality of life, particularly among vulnerable populations.

Level of perceived social support, and associated factors, in combat-exposed (ex-)military personnel: a systematic review and meta-analysis.

PURPOSE: Combat deployment increases exposure to potentially traumatic events. Perceived social support (PSS) may promote health and recovery from combat trauma. This systematic review and meta-analysis aimed to synthesize studies investigating the level of PSS and associated factors among (ex-)military personnel who served in the Iraq/Afghanistan conflicts. METHODS: Five electronic databases were searched in August 2023 and searches were restricted to the beginning of the Iraq/Afghanistan conflicts in 2001. The search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A quality assessment was carried out, and a meta-analysis and narrative synthesis were performed. RESULTS: In total, 35 papers consisting of 19,073 participants were included. Of these, 31 studies were conducted in the United States (US) and 23 were cross-sectional. The pooled mean PSS score was 54.40 (95% CI: 51.78 to 57.01). Samples with probable post-traumatic stress disorder had a lower mean PSS score (44.40, 95% CI: 39.10 to 49.70). Approximately half of the included studies (n = 19) investigated mental health in relation to PSS, whilst only four explored physical health. The most frequently reported risk factors for low PSS included post-traumatic stress disorder, depression and anxiety, whilst post-traumatic growth and unit support were protective factors. CONCLUSION: Higher levels of PSS were generally associated with more positive psychosocial and mental health-related outcomes following deployment. PSS should be targeted in psychosocial interventions and education programmes. Future research should investigate PSS in (ex-)military personnel across other countries and cultures, based on the lack of studies that focused on PSS in countries outside of the US.

Drivers of vulnerability to medicine smuggling and combat strategies: a qualitative study based on online news media analysis in Iran.

BACKGROUND: Medicine smuggling poses a serious public health threat, limiting patients' safe and timely access to this essential resource. Thus, this study aims to identify the factors contributing to the vulnerability to medicine smuggling and propose effective strategies to combat this issue in Iran. METHODS: An analysis of news media was conducted using qualitative content analysis. News text items related to medicine smuggling were retrieved from various online news sources between March 21, 2017, and May 21, 2023. To select health-oriented and general online news stations, news agencies, and newspapers, the purposeful sampling method with a maximum variation strategy was used. The selected sources included Mehr News Agency, Khabar Online, Islamic Consultative Assembly News Agency (ICANA), Islamic Republic News Agency (IRNA), Iranian Students News Agency (ISNA), Hamshahri, Donya-e-Eqtesad newspapers, Webda, Sepid Online, and Iran's Food and Drug Administration News Agency (IFDANA). All data coding was manually done using Microsoft Excel software version 2016. RESULTS: A total of 277 news articles were found to meet the established criteria for inclusion. The analysis revealed four main themes, each with several sub-themes, that shed light on the factors that drive vulnerability and the strategies to combat medicine smuggling. These themes are the economic environment, government and stewardship, information technology systems, and socio-cultural factors. The economic environment emerged as the most significant theme, encompassing medicine selection, reimbursement, and procurement, all of which affect the smuggling of pharmaceuticals in Iran. CONCLUSION: To combat medicine smuggling, it is important to adjust policies based on the identified vulnerabilities. Effective strategies to reverse pharmaceutical smuggling include capacity building of pharmaceutical manufacturing companies, implementing regulated and enhanced supervisory and rulemaking policies, strengthening health insurance, improving e-infrastructure, and increasing public awareness through collaborative approaches involving various stakeholders within and outside the health system.

Combat stress in a small-scale society suggests divergent evolutionary roots for posttraumatic stress disorder symptoms.

Military personnel in industrialized societies often develop posttraumatic stress disorder (PTSD) during combat. It is unclear whether combat-related PTSD is a universal evolutionary response to danger or a culture-specific syndrome of industrialized societies. We interviewed 218 Turkana pastoralist warriors in Kenya, who engage in lethal cattle raids, about their combat experiences and PTSD symptoms. Turkana in our sample had a high prevalence of PTSD symptoms, but Turkana with high symptom severity had lower prevalence of depression-like symptoms than American service members with high symptom severity. Symptoms that facilitate responding to danger were better predicted by combat exposure, whereas depressive symptoms were better predicted by exposure to combat-related moral violations. The findings suggest that some PTSD symptoms stem from an evolved response to danger, while depressive PTSD symptoms may be caused by culturally specific moral norm violations.

Acute and Chronic Weight-Making Practice in Professional Mixed Martial Arts Athletes: An Analysis of 33 Athletes Across 80 Fights.

Mixed martial arts' popularity has increased in recent years, alongside descriptive research and evidence-based performance recommendations. Guidelines for (both chronic and acute) weight making exist; however, how these translate in real-life scenarios and detailed investigations on practices in larger groups deserve attention. The present study examined the body mass (BM) and composition of 33 professional mixed martial arts athletes preparing for 80 fights. Athletes were supported by on-site dietitians, who encouraged evidence-based practices. Fasted BM was measured throughout the last ∼10 days before all bouts (acute weight management phase). A subset of athletes had body composition assessed before and after the chronic weight loss phase for 40 fights. Most athletes engaged in chronic BM loss, and all engaged in acute weight loss. Many lost fat-free mass (FFM) during the chronic phase, with rates of BM loss <0.5% best preserving FFM. Regardless of losses, the present athletes possessed greater FFM than other combat sport athletes and engaged in greater acute weight loss. Dehydration in the 24-48 hr before the weigh-in was not reflective of weight regain after the weigh-in, rather BM 7-10 days before the weigh-in was most reflective. These findings suggest that many mixed martial arts athletes could increase FFM at the time of competition by maintaining leaner physiques outside of competition and/or allowing increased time to reduce BM chronically. Acutely, athletes can utilize evidence-based protocols, eliminating carbohydrates, fiber, sodium, and finally fluid in a staged approach, before the weigh-in, reducing the amount of sweating required, thus theoretically better protecting health and preserving performance.

COMBAT-C: COntrol of Major Bleeding by Application of Tourniquets over Clothing.

INTRODUCTION: External bleeding is the leading cause of preventable trauma-related death. In certain circumstances, tourniquet application over clothing may be necessary. Therefore, the aim of this study was to assess the effectiveness of tourniquets over different clothing setups. METHODS: Three windlass tourniquets (CAT, SAMXT, SOFTT-W) were applied over nine different clothing setups and without clothing on the Hapmed™ Tourniquet Trainer. We compared each tourniquet in each clothing setup to the tourniquet trainer that was not dressed, and we compared the three tourniquets within each clothing setup concerning blood loss, applied pressure and application time. Regression analysis of the effect of thickness, mean weight, mean deformation, application time, and applied pressure on blood loss was performed. RESULTS: Although blood loss was significantly greater in the CAT and SAMXT tourniquets when they were applied over leather motorcycle trousers, the overall findings showed that the clothing setups significantly reduced or did not affect blood loss. The mean blood loss was the lowest with CAT and the highest with SOFTT-W. The measured mean pressures were lower than 180 mmHg in four out of nine clothing setups with SOFTT-W, but CAT and SAMXT always exceeded this threshold. CAT had the fastest application time. Blood loss was significantly influenced by applied pressure and application time but was influenced to a far lesser degree by clothing parameters. CONCLUSION: The effects of the clothing setups were of little clinical relevance, except for leather motorcycle trousers. The effects of rugged protective equipment, e.g., hazard suits, are conceivable and need to be tested for specific garments with the tourniquet intended for use. No clothing parameter for predicting tourniquet effectiveness could be identified.