A Compact Handheld Sensor Package with Sensor Fusion for Comprehensive and Robust 3D Mapping.

This paper introduces an innovative approach to 3D environmental mapping through the integration of a compact, handheld sensor package with a two-stage sensor fusion pipeline. The sensor package, incorporating LiDAR, IMU, RGB, and thermal cameras, enables comprehensive and robust 3D mapping of various environments. By leveraging Simultaneous Localization and Mapping (SLAM) and thermal imaging, our solution offers good performance in conditions where global positioning is unavailable and in visually degraded environments. The sensor package runs a real-time LiDAR-Inertial SLAM algorithm, generating a dense point cloud map that accurately reconstructs the geometric features of the environment. Following the acquisition of that point cloud, we post-process these data by fusing them with images from the RGB and thermal cameras and produce a detailed, color-enriched 3D map that is useful and adaptable to different mission requirements. We demonstrated our system in a variety of scenarios, from indoor to outdoor conditions, and the results showcased the effectiveness and applicability of our sensor package and fusion pipeline. This system can be applied in a wide range of applications, ranging from autonomous navigation to smart agriculture, and has the potential to make a substantial benefit across diverse fields.

A framework of transient hypercapnia to achieve an increased cerebral blood flow induced by nasal breathing during aerobic exercise.

During exercise, cerebral blood flow (CBF) is expected to only increase to a maximal volume up to a moderate intensity aerobic effort, suggesting that CBF is expected to decline past 70 % of a maximal aerobic effort. Increasing CBF during exercise permits an increased cerebral metabolic activity that stimulates neuroplasticity and other key processes of cerebral adaptations that ultimately improve cognitive health. Recent work has focused on utilizing gas-induced exposure to intermittent hypoxia during aerobic exercise to maximize the improvements in cognitive function compared to those seen under normoxic conditions. However, it is postulated that exercising by isolating breathing only to the nasal route may provide a similar effect by stimulating a transient hypercapnic condition that is non-gas dependent. Because nasal breathing prevents hyperventilation during exercise, it promotes an increase in the partial arterial pressure of CO2. The rise in systemic CO2 stimulates hypercapnia and permits the upregulation of hypoxia-related genes. In addition, the rise in systemic CO2 stimulates cerebral vasodilation, promoting a greater increase in CBF than seen during normoxic conditions. While more research is warranted, nasal breathing might also promote benefits related to improved sleep, greater immunity, and body fat loss. Altogether, this narrative review presents a theoretical framework by which exercise-induced hypercapnia by utilizing nasal breathing during moderate-intensity aerobic exercise may promote greater health adaptations and cognitive improvements than utilizing oronasal breathing.

Supramolecular Assembly of His-Tagged Fluorescent Protein Guests within Coiled-Coil Peptide Crystal Hosts: Three-Dimensional Ordering and Protein Thermal Stability.

The use of biomaterials for the inclusion and stabilization of biopolymers is an ongoing challenge. Herein, we disclose three-dimensional (3D) coiled-coil peptide crystals with metal ions that include and overgrow His-tagged fluorescent proteins within the crystal. The protein guests are found within two symmetry-related growth sectors of the crystalline host that are associated with faces of the growing crystal that display ligands for metal ions. The fluorescent proteins are included within this "hourglass" region of the crystals at a notably high level, display order within the crystal hosts, and demonstrate sufficiently tight packing to enable energy transfer between a donor-acceptor pair. His-tagged fluorescent proteins display remarkable thermal stability to denaturation over extended periods of time (days) at high temperatures when within the crystals. Ultimately, this strategy may prove useful for the prolonged storage of thermally sensitive biopolymer guests within a 3D crystalline matrix.

Factors Associated With Noncontact Injury in Collegiate Soccer: A 12-Team Prospective Study of NCAA Division I Men's and Women's Soccer.

BACKGROUND: Multiteam, multi-institution prospective studies of both women's and men's sports are essential for collectively investigating injury and primary to the generalization and individualization of injury prevention strategies. HYPOTHESIS: Characteristics of workload, sleep, and contextual factors will be associated with injury risk in collegiate soccer athletes. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Injuries, workload, and sleep characteristics were recorded daily throughout a complete season for 256 athletes from 12 separate National Collegiate Athletic Association Division I men's and women's soccer teams. Workload and contextual factors were assessed via multilevel Poisson regression to capture differences in injury incidence rate ratio (IRR). Paired t test and multilevel logistic regressions were used to assess the relationship between sleep behavior and injury. RESULTS: Collegiate soccer athletes had lower rates of noncontact injury in the in-season (IRR, 0.42) and postseason (IRR, 0.48) compared with preseason, lower rates of injury in training (IRR, 0.64) compared with matches, and higher injury rates with only 1 day of rest in the previous week (IRR, 1.58) compared with >1 day. Injury rates peaked when training occurred 4 days before a match (IRR, 2.24) compared with a match. Injury rate increased exponentially with increases in the number of noncontact injuries incurred throughout the season (IRR, 2.23). Lower chronic loading, higher training monotony, and acute spikes and lulls in workload were associated with higher noncontact injury rates. Alterations in previous week sleep quality were associated with injury, while chronic sleep behavior and acute alterations (<7 days) in sleep behavior were not (P > .05). CONCLUSION: Athlete and schedule-specific contextual factors, combined with characteristics of workload and weekly sleep behavior, are significantly associated with injury in collegiate soccer. Multiteam prospective cohort studies involving objective and subjective monitoring allow for the identification of multiple injury risk factors in sports, which can be used to guide injury prevention strategies. Maintaining higher chronic workloads, lowering training monotony, minimizing acute spikes or lulls in workloads, managing workloads during preseason and for athletes with previous injury, integrating more rest and recovery during congested periods, and optimizing sleep quality are all practical considerations for reducing injury risk in collegiate soccer.

Comparing the Sensitivity of a Low Frequency Versus a High Frequency Probe in the Detection of Pneumothorax in a Swine Model.

BACKGROUND: Correct diagnosis of pneumothorax in trauma patients is essential. Under-diagnosis can lead to development of life-threatening tension pneumothorax, but overdiagnosis leads to placement of unnecessary chest tubes with potential related morbidity and pain. It is unclear from previous work if there is a benefit to switching from the phased array (low frequency) probe to the linear (high frequency) probe. Is the improvement in image quality worth the time lost changing probes? METHODS: We compared the sensitivity and specificity of a low frequency and high frequency ultrasound probe for the detection of pneumothorax. Images were obtained using swine models and were interpreted by Emergency Medicine residents, attendings, and physician assistants. RESULTS: We found a specificity of 89% and sensitivity of 99% for the low frequency probe and specificity of 96% and sensitivity of 99% for the high frequency probe. There was a statistically different specificity between the two probes, suggesting that the linear probe may be the superior probe for confirming the presence of pneumothorax. CONCLUSION: We conclude switching to the linear probe for the thoracic portion of the Extended-Focused Assessment in Trauma will lead to more accurate diagnosis of pneumothorax and decreased false-positive exams.

Formation of Microcages from a Collagen Mimetic Peptide via Metal-Ligand Interactions.

Here, the hierarchical assembly of a collagen mimetic peptide (CMP) displaying four bipyridine moieties is described. The CMP was capable of forming triple helices followed by self-assembly into disks and domes. Treatment of these disks and domes with metal ions such as Fe(II), Cu(II), Zn(II), Co(II), and Ru(III) triggered the formation of microcages, and micron-sized cup-like structures. Mechanistic studies suggest that the formation of the microcages proceeds from the disks and domes in a metal-dependent fashion. Fluorescently-labeled dextrans were encapsulated within the cages and displayed a time-dependent release using thermal conditions.

Femoral Pulse Ultrasound Assessment Accuracy by Emergency Medicine Trainees on a Porcine Model.

of care ultrasound (POCUS) is increasingly used in emergency medicine (EM), including EM physician residents and EM physician assistant (EMPA) residents. Scant literature assesses accuracy and duration of POCUS pulse assessment by this group during cardiac resuscitation given recommendations for minimal pauses in chest compressions. Evaluation is needed for accuracy and duration of pulse interpretation in EM trainees utilizing POCUS. METHODS: We conducted a double-blind observational study of EM clinician trainee POCUS assessment of pulses using porcine models. Volunteers were blinded to the cardiac status of 5 porcine models randomized as deceased or living and performed femoral artery evaluation using color power Doppler POCUS. The primary outcome was accuracy of pulse assessment. Secondary outcomes included time to verbalization and differences based on reported duration of EM training, experience with ultrasound, and cardiac arrest resuscitation experience. RESULTS: 17 EM and EMPA trainees completed 85 total POCUS pulse assessments with 98.82% accuracy (n=84). Mean verbalization time was 6.95 seconds, and most verbalized interpretations were within 10-seconds (82.4%, n=70). This was grossly consistent between living and deceased models. Subgroup analysis found no significant differences of accuracy or verbalization time based on reported demographics. CONCLUSION: EM clinician trainees demonstrate a high degree of accuracy and low average time for verbalized interpretation of femoral artery pulse assessment, most within recommended time guidelines. Further study is needed to correlate these findings in human patients.

The Relationships Between Perceived Wellness, Sleep, and Acute: Chronic Training Load in National Collegiate Athletics Association Division I Male Soccer Players.

ABSTRACT: Sekiguchi, Y, Curtis, RM, Huggins, RA, Benjamin, CL, Walker, AJ, Arent, SM, Adams, WM, Anderson, T, and Casa, DJ. The relationships between perceived wellness of, sleep of, and acute: chronic training load on National Collegiate Athletics Association division I male soccer players. J Strength Cond Res 35(5): 1326-1330, 2021-The purpose of this study was to investigate relationships between perceived wellness, sleep, and acute: chronic workload ratio (ACWR) throughout a collegiate men's soccer season. Sixty male collegiate soccer players (mean[M] ± SD; age, 21±2 year; body mass, 77.6 ± 6.5 kg; height, 180.1 ± 6.4 cm; body fat%, 9.9 ± 3.9% ; and V̇o2max, 53.1 ± 5.0 ml·kg-1·min-1) participated in this study. During each session, players used a heart rate and global positioning satellite-enabled chest strap to measure training impulse and ACWR. The ACWR values were trichotomized at the individual level giving an equal number of observations within each ACWR category of low, moderate, and high ACWR (M ± SD; low, 0.658 ± 0.23; moderate, 0.92 ± 0.15; and high, 1.17 ± 0.16). Stress, fatigue, and soreness levels were collected using 1-10 Likert scales and sleep duration, and sleep quality were measured by the Karolinska Sleep Diary. Stress, fatigue, soreness levels, and sleep quality were transformed to corresponding z-scores at the individual level. Fatigue levels were significantly higher when ACWR was high compared with low (mean difference [95% confidence intervals], effect size, p-value; 0.31 [0.21, 0.42], 0.29, p < 0.001) and moderate (0.14 [0.03, 0.24], 0.13, p = 0.01). Fatigue levels were also significantly higher when the ACWR was moderate compared with low (0.18 [0.07, 0.28], 0.16, p = 0.001). Soreness levels were significantly higher when the ACWR was high compared with low (0.25 [0.14, 0.36], 0.23, p < 0.001). Stress levels were significantly greater when the ACWR was high compared with low (0.19, [0.08, 0.29], 0.18, p < 0.001) and compared with moderate (0.15, [0.05, 0.25], 0.14, p = 0.004). There were no differences in sleep duration or sleep quality in different ACWR. The ACWR may be a useful tool to achieve an appropriate balance between training and recovery to manage daily fatigue and soreness levels in athletes.

Relationship Between Heart Rate Variability and Acute:Chronic Load Ratio Throughout a Season in NCAA D1 Men's Soccer Players.

ABSTRACT: Sekiguchi, Y, Huggins, RA, Curtis, RM, Benjamin, CL, Adams, WM, Looney, DP, West, CA, and Casa, DJ. Relationship between heart rate variability and acute:chronic load ratio throughout a season in NCAA D1 men's soccer players. J Strength Cond Res 35(4): 1103-1109, 2021-The purpose of this study was twofold: (a) to examine the relationship between heart rate variability (HRV) and acute:chronic workload ratio (ACWR)-based training load (TL) metrics and (b) to examine relationships across various A:C ratio-based TL metrics. Heart rate variability in 23 male college soccer players (mean ± SD; age, 21 ± 1 years; body mass, 80.3 ± 5.8 kg; height, 181.9 ± 6.5 cm; %body fat, 11.9 ± 2.0%; and V̇o2max, 51.9 ± 5.0 ml·kg-1·min-1) was measured at 5 time points: week(W)1, W3, W7, W12, and W14 during the 2015 NCAA men's soccer season. Heart rate variability was calculated from beat to beat intervals using a heart rate monitor. Players donned a global position satellite-enabled device that measured the following TL metrics: session time (ST), Player Load (PL), PL·min-1, and total distance (TD). Acute:chronic workload ratio was calculated for each TL metric: ACWR-based ST (ACWRST), ACWR-based PL (ACWRPL), ACWR-based PL·min-1 (ACWRPLM), and ACWR-based TD (ACWRTD): ACWR = week average TLs/mo average (30 ± 1 days) TLs. Relationships between HRV and ACWR-based each TL metric were evaluated using mixed effects models. Tukey pairwise comparisons were used to examine differences between types of ACWR-based TL metrics. An increase in ACWRST significantly reduced HRV throughout a season (-7.4 ± 3.6 m·s-1; p = 0.04). There were significant differences between ACWRPLM and ACWRST, ACWRPL and ACWRTD at W1, ACWRPLM and ACWRST at W3 (p < 0.05). In conclusion, ACWRST, ACWRPL, and ACWRTD were significantly different from ACWRPLM. ACWRST was found to significantly predict HRV; higher ACWRST was significantly associated with lower HRV. Therefore, tracking of the ACWR using ST may help to optimize athlete's physiological state throughout a season.

Seasonal Accumulated Workloads in Collegiate Men's Soccer: A Comparison of Starters and Reserves.

ABSTRACT: Curtis, RM, Huggins, RA, Benjamin, CL, Sekiguchi, Y, Arent, S, Armwald, B, Pullara, JM, West, CA, and Casa, DJ. Seasonal accumulated workloads in collegiate men's soccer: a comparison of starters and reserves. J Strength Cond Res 35(11): 3184-3189, 2021-The purpose of this investigation was to quantify and compare player's season total-, match-, and training-accumulated workload by player status characteristics (i.e., starter vs. reserve) in American collegiate men's soccer. Global positioning system (GPS) and heart rate (HR)-derived workloads were analyzed from 82 collegiate male soccer athletes from 5 separate teams over the 2016 and 2017 seasons. Differences in total physical and physiological workloads (i.e., total distance, accelerations, and weighted HR-zone training impulse [TRIMP] score) as well as workloads over a range of intensity zones were examined using multilevel mixed models, with mean difference (MD) and effect size (ES) reported. Starters accumulated substantially more total distance (MD = 82 km, ES = 1.23), TRIMP (MD = 2,210 au, ES = 0.63), and total accelerations (MD = 6,324 n, ES = 0.66) over the season. Total accumulated distance in all velocity zones (ES [range] = 0.87-1.08), all accelerations zones (ES [range] = 0.54-0.74), and time spent at 70-90% HRmax (ES [range] = 0.60-1.12) was also greater for starters. Reserves accumulated substantially more total distance (MD = 20 km, ES = 0.43) and TRIMP (MD = 1,683 au, ES = 0.79) during training. Although reserves show elevated physical and physiological loads during training compared with starters, there is an imbalance in overall workloads between player roles, with starters incurring substantially more match and total seasonal workloads. These results indicate managing player workloads in soccer requires attention to potential imbalances between players receiving variable match times. Coaches and practitioners in collegiate men's soccer may consider implementing strategies to reduce discrepancies in loading between starters and reserves. Individualized monitoring of training and match workloads may assist in the implementation of more balanced load management programs.

The Validity and Reliability of Global Positioning System Units for Measuring Distance and Velocity During Linear and Team Sport Simulated Movements.

Huggins, RA, Giersch, GEW, Belval, LN, Benjamin, CL, Curtis, RM, Sekiguchi, Y, Peltonen, J, and Casa, DJ. The validity and reliability of GPS units for measuring distance and velocity during linear and team sport simulated movements. J Strength Cond Res 34(11): 3070-3077, 2020-This experimental study aimed to assess the validity and reliability of shirt-mounted 10-Hz global positioning system (GPS) units (Polar Team Pro) for measuring total distance (TD), constant velocity (VelC), and instantaneous velocity (VelI) during linear running and a team sport simulation circuit (TSSC). Fifteen male soccer athletes completed linear tasks (40 and 100 m) at various velocities: walk (W) (4.8-7.9 km·h), jog (J) (8.0-12.7 km·h), run (R) (12.9-19.9 km·h), and sprint (S) (>20.0 km·h) and a 120-m TSSC. Global positioning system validity and reliability for TD, VelC, and VelI were compared with criterion measures using 2 methods (a and b) of GPS raw data extraction. When measuring TD for the Polar Team Pro device, validity and reliability measures were <5% error at all velocities during the 40-m (with the exception of the S [%CV = 8.03]) and 100-m linear trial (both extraction methods) and TSSC. The GPS mean difference (±SD) for TD during the TSSC using extraction methods (a) and (b) was 0.2 ± 1.2 and 2.2 ± 2.2 m, respectively. The validity of the device in measuring VelC was significantly different (p < 0.05) at all velocities during the 40 m (exception W) and the 100 m, with effect sizes ranging from trivial to small (exception of 100 m S). VelI was similar (p > 0.05) at all velocities, except for the W (p = 0.001). The reliability of the device when measuring VelC during the 40 and 100 m was <5% CV; however, during the 100 m, VelI ranged from 1.4 to 12.9%. Despite trivial to large effect sizes for validity of TD, this device demonstrated good reliability <5% CV during linear and TSSC movements. Similarly, effect sizes ranged from trivial to large for VelC, and yet VelI reliability was good for VelC, but good to poor for VelI.

Sleep Dysfunction and Mood in Collegiate Soccer Athletes.

BACKGROUND: Sleep and mood are critical factors that contribute to health and wellness and are of particular interest to collegiate athletes who are juggling high physical, academic, and social demands. The aim of this study was to examine how psychological measures, player status, and sex-related factors were associated with perceived sleep quality. HYPOTHESIS: Higher levels of global sleep dysfunction will be related to poor mood and increased anxiety, and there will be differences in sleep dysfunction in male compared with female athletes as well as regarding playing status. STUDY DESIGN: Prospective cohort study. LEVEL OF EVIDENCE: Level 4. METHODS: During the 2016 through 2018 National Collegiate Athletic Association (NCAA) seasons, the Pittsburgh Sleep Quality Index (PSQI), Profile of Mood States, and Sports Anxiety Scale-2 questionnaires were administered to 230 soccer athletes at 6 separate time points throughout each season. RESULTS: PSQI results yielded scores ≥5 in 54% of observations. Increased sleep dysfunction was significantly related to decreased vigor and increased tension, depression, anger, fatigue, somatic anxiety, worry, and concentration disruption, although effect sizes (ES) were trivial (ES, -0.03 to 0.15). The odds ratio (OR) of reporting global sleep dysfunction increased by 8%, 9%, and 25% for every 1-unit increase in tension (OR, 1.08; 95% CI, 1.02-1.16; P = 0.015), fatigue (OR, 1.09; 95% CI, 1.03-1.16; P = 0.002), and concentration disruption (OR, 1.25; 95% CI, 1.09-1.45; P = 0.002), respectively. The odds of reporting global sleep dysfunction were 55% lower for males than females (OR, 0.45; 95% CI, 0.25-0.79; P = 0.006). CONCLUSION: Global sleep dysfunction was prevalent in NCAA soccer players and was related to negative mental health outcomes. Female participants experienced increased odds of reporting global sleep dysfunction. CLINICAL RELEVANCE: Regular monitoring allows for a greater understanding of the interrelatedness between sleep and mental health in athletes.

Fluorescent Probes for Monitoring Serine Ubiquitination.

In a radical departure from the classical E1-E2-E3 three-enzyme mediated ubiquitination of eukaryotes, the recently described bacterial enzymes of the SidE family of Legionella pneumophila effectors utilize NAD+ to ligate ubiquitin onto target substrate proteins. This outcome is achieved via a two-step mechanism involving (1) ADP ribosylation of ubiquitin followed by (2) phosphotransfer to a target serine residue. Here, using fluorescent NAD+ analogues as well as synthetic substrate mimics, we have developed continuous assays enabling real-time monitoring of both steps of this mechanism. These assays are amenable to biochemical studies and high-throughput screening of inhibitors of these effectors, and the discovery and characterization of putative enzymes similar to members of the SidE family in other organisms. We also show their utility in studying enzymes that can reverse and inhibit this post-translational modification.

Environmental Conditions, Preseason Fitness Levels, and Game Workload: Analysis of a Female NCAA DI National Championship Soccer Season.

Benjamin, CL, Hosokawa, Y, Curtis, RM, Schaefer, DA, Bergin, RT, Abegg, MR, and Casa, DJ. Environmental conditions, preseason fitness levels, and game workload: Analysis of a female NCAA DI National Championship Soccer Season. J Strength Cond Res 34(4): 988-994, 2020-The purpose of this study was to determine the independent and combined moderating effect of aerobic fitness and environmental conditions on physical workloads during collegiate female soccer matches. Nineteen National Collegiate Athletic Association female soccer athletes were included in this study (mean ± SD: age, 20.6 ± 1.4 years; height, 169 ± 6.1 cm; body mass 64.7 ± 5.3 kg). Maximal oxygen consumption (V[Combining Dot Above]O2max) was estimated from the yo-yo intermittent recovery test before preseason training and wet-bulb globe temperature (WBGT) was recorded onsite for home matches and at the nearest weather station for away matches. Relative distance (TD), relative high-speed running distance (%HSD), and relative high metabolic load (%HML) performance were collected during each match using a global positioning system unit (Viper Pod; STATSports, Chicago, IL). Statistically significant differences were observed in TD between LOW WBGT and MOD WBGT (mean difference [MD] = 7.08 m·min; effect size [ES] = 0.54; p < 0.001), in %HSD between LOW WBGT and MOD WBGT (MD = 1.97%; ES = 0.64; p = 0.01) and between LOW WBGT and HIGH WBGT (MD = 2.71%; ES = 1.01; p < 0.001), and in %HML between LOW WBGT and MOD WBGT (MD = 1.24%; ES = 0.56; p < 0.001) and between LOW WBGT and HIGH WBGT (MD = 1.55%; ES = 0.78; p = 0.01). There was a significant interaction between WBGT and V[Combining Dot Above]O2max for %HSD (p = 0.03). These findings demonstrate that physical performance metrics were affected by increased WBGT. In addition, aerobic fitness seemed to moderate the effect of increasing WBGT on %HSD, meaning maximizing aerobic capacity is important for optimizing running performance in the heat. Coaches and sports medicine staff could alter training time and session length based on environmental conditions as well as potentially use aggressive cooling strategies to mitigate the imposed heat stress and decrements in physical performance.

Contextual Factors Influencing External and Internal Training Loads in Collegiate Men's Soccer.

Curtis, RM, Huggins, RA, Benjamin, CL, Sekiguchi, Y, Adams, WM, Arent, SM, Jain, R, Miller, SJ, Walker, AJ, and Casa, DJ. Contextual factors influencing external and internal training loads in collegiate men's soccer. J Strength Cond Res 34(2): 374-381, 2020-This study investigated factors influencing training loads (TL) in collegiate men's soccer. Total distance, high-speed running distance (>14.4 km·h), high-intensity heart-rate zone duration (HI HRZ, >70% heart rate relative to maximum), and session rating of perceived exertion were assessed daily from 107 male soccer players competing for 5 National Collegiate Athletics Association Division I teams. Differences between athlete role (starter and reserve), position (defender, midfielder, and forward), season phase (preseason, in-season, and postseason), days relative to match (MD-1 to MD-5+), days between matches (<4, 4-5, >5 days), previous match outcome (win, loss, and draw), and upcoming opponent relative ranking (weaker, trivial, and stronger) were examined. Mean differences (MD) and effect sizes (ESs) with 90% confidence intervals were reported. There were trivial and insignificant differences by player role, position, or upcoming opponent strength, and small-moderate increases in preseason TL compared with in-season (ES [range] = 0.4-0.9). TLs were lower for MD-1 and higher for MD-5+ (ES [range] = 0.4-1.3) when compared with MD-2-4. External loads (ES = -0.40 ± 0.20) were less after wins compared with losses. TLs are increased in the preseason, when training sessions occur greater than 5 days from a match and after losses. Contextualizing factors affecting TLs has implications for developing workload prescription and recovery strategies.

A Comparison of the Laryngeal Handshake Method Versus the Traditional Index Finger Palpation Method in Identifying the Cricothyroid Membrane, When Performed by Combat Medic Trainees.

BACKGROUND: The laryngeal handshake method (LHM) may be a reliable standardized method to quickly and accurately identify the cricothyroid membrane (CTM) when performing an emergency surgical airway (ESA). However, there is currently minimal available literature evaluating the method. Furthermore, no previous CTM localization studies have focused on success rates of military prehospital providers. This study was conducted with the goal of answering the question: Which method is superior, the LHM or the traditional method (TM), for identifying anatomical landmarks in a timely manner when performed by US Army combat medic trainees? METHODS: This prospective randomized crossover study was conducted at Ft Sam Houston, TX, in September 2018. Two Army medic trainees with similar body habitus volunteered as subjects, and the upper and lower borders and midline of their CTMs were identified by ultrasound (US). The participants were also recruited from the medic trainee population. After receiving initial training on the LHM and refresher training on the TM, participants were asked to localize the CTMs of each subject with one method per subject. Success was defined as a marking within the borders and 5mm of midline within 2 minutes. RESULTS: Thirty-two combat medic trainees participated; 78% (n = 25) successfully localized the CTM using the TM versus 41% (n = 13) using the LHM (p = .002). CONCLUSION: Findings of this study support that at present the TM is a superior method for successful localization of the CTM when performed by Army combat medic trainees.

Relationships between resting heart rate, heart rate variability and sleep characteristics among female collegiate cross-country athletes.

Even though sleep has been shown to be influenced by athletes' training status, the association with resting heart rate and heart rate variability remains unclear. The purpose of this study was to compare the changes in and relationships between resting heart rate, heart rate variability and sleep characteristics across a female collegiate cross-country season. Ten NCAA Division I collegiate female cross-country athletes (mean ± SD; age, 19 ± 1 year; height, 167.6 ± 7.6 cm; body mass, 57.7 ± 10.2 kg; VO2max , 53.3 ± 5.9 ml kg-1  min-1 ) participated in this study. Resting heart rate, heart rate variability and the percentage of time in slow wave sleep were captured using a wrist-worn multisensor sleep device throughout the 2016 competitive cross-country season (12 weeks). Linear mixed-effects models and magnitude-based inferences were used to assess differences between each week. Pearson product moment correlations were used to investigate relationships between variables. Resting heart rate at the end of the season, specifically during weeks 10-12 (mean ± SE; week 10, 48 ± 2; week 11, 48 ± 3; week 12, 48 ± 3), showed a practically meaningful increase compared to the beginning of the season, weeks 2-4 (week 2, 44 ± 2; week 3, 45 ± 2; week 4, 44 ± 2). Higher resting heart rate (r = 0.55) and lower heart rate variability (r = -0.62) were largely associated with an increase in percentage of time spent in slow wave sleep. These data suggest that when physiological state was impaired, meaning the physiological restorative demand was higher, the percentage of time in slow wave sleep was increased to ensure recovery. Thus, it is important to implement sleep hygiene strategies to promote adequate slow wave sleep when the body needs physiological restoration.

Monitoring Blood Biomarkers and Training Load Throughout a Collegiate Soccer Season.

Huggins, RA, Fortunati, AR, Curtis, RM, Looney, DP, West, CA, Lee, EC, Fragala, MS, Hall, ML, and Casa, DJ. Monitoring blood biomarkers and training load throughout a collegiate soccer season. J Strength Cond Res 33(11): 3065-3077, 2019-This observational study aimed to characterize the responses of a comprehensive panel of biomarkers, observed ranges, training load (TL) metrics, and performance throughout the collegiate soccer season (August-November). Biomarkers (n = 92) were collected before the start of pre-season (PS), in-season weeks (W)1, W4, W8, and W12 in NCAA Division I male soccer players (n = 20, mean ± SD; age = 21 ± 1 years, height = 180 ± 6 cm, body mass = 78.19 ± 6.3 kg, body fat = 12.0 ± 2.6%, VO2max 51.5 ± 5.1 ml·kg·min). Fitness tests were measured at PS, and W12 and TL was monitored daily. Changes in biomarkers and performance were calculated via separate repeated-measures analysis of variance. Despite similar fitness (p > 0.05), endocrine, muscle, inflammatory, and immune markers changed over time (p < 0.05). Total and free testosterone was lower in W1 vs. PS, whereas free cortisol remained unchanged at PS, W1, and W4 (>0.94 mg·dL). Oxygen transport and iron metabolism markers remained unchanged except for HCT (W1 vs. PS) and total iron binding capacity (W8-W12 vs. W1). Hepatic markers albumin, globulin, albumin:globulin, and total protein levels were elevated (p < 0.05) at W12 vs. W1, whereas aspartate aminotransferase and alanine aminotransferase levels were elevated at W1-W12 and W8-W12 vs. PS, respectively. Vitamin E, zinc, selenium, and calcium levels were elevated (p < 0.05) at W12 vs. W1, whereas Vitamin D was decreased (p < 0.05). Fatty acids and cardiovascular markers (omega-3 index, cholesterol:high-density lipoprotein [HDL], docosahexenoic acid, low-density lipoprotein [LDL], direct LDL, non-HDL, ApoB) were reduced at W1 vs. PS (p ≤ 0.05). Immune, lipid, and muscle damage biomarkers were frequently outside clinical reference ranges. Routine biomarker monitoring revealed subclinical and clinical changes, suggesting soccer-specific reference ranges. Biomarker monitoring may augment positive adaptation and reduce injuries from stressors incurred during soccer.

Factors influencing hydration status during a National Collegiate Athletics Association division 1 soccer preseason.

OBJECTIVES: To investigate the roles that training load and environmental conditions have on fluid balance during a collegiate men's soccer preseason. DESIGN: Observational study. METHODS: Twenty-eight male collegiate soccer players (mean±SD; age, 20±1.7y; body mass (BM), 79.9±7.3kg; height, 180.9±6.8cm; body fat, 12.7±3.1%; VO2max, 50.7±4.3ml·kg-1·min-1) participated in this study. Prior to (PRE) and following (POST) each team session, BM, percent BM loss (%BML) and hydration status was measured. Participants donned a heart rate and GPS enabled monitor to measure training load. For all team activities, ambient temperature (TAMB) and relative humidity (RH) were obtained from the nearest local weather station. Participants consumed 500mL of water as part of the team-based hydration strategy before and after training session. Stepwise linear regression was used to identify the variables that predicted %BML. Significance was set a-priori p<0.05. RESULTS: Total distance covered predicted %BML during all preseason activities (r2=0.253, p<0.001), with TAMB and RH further adding to the model (r2=0.302, p<0.001). %BML never exceeded 2% of BM during any one session and daily variation in BM was <1% from baseline measures. Urine specific gravity was greater than 1.020 on 12/15days and UCOL was above 4 on 13/15days, indicating a state of hypohydration. CONCLUSIONS: Total distance covered was the best predictor for the extent of body water losses during a collegiate preseason. While the team-based hydration strategy during preseason was successful in minimizing fluid losses during activity, participants arrived hypohydrated 80% of the time, necessitating a greater focus on daily fluid needs.