Analysis of Sleep, Nocturnal Physiology, and Physical Demands of NCAA Women's Ice Hockey Across a Championship Season.

ABSTRACT: Merrigan, JJ, Stone, JD, Kraemer, WJ, Friend, C, Lennon, K, Vatne, EA, and Hagen, JA. Analysis of sleep, nocturnal physiology, and physical demands of NCAA women's ice hockey across a championship season. J Strength Cond Res 38(4): 694-703, 2024-The aims of this study were to evaluate the (a) relationships between daily physical demands and nighttime sleep, heart rate (HR), and heart rate variability (HRV); (b) weekly changes in physical demands and sleep; and (c) differences among positions and between training and competition during a competitive season in National Collegiate Athletic Association (NCAA) women's ice hockey. Twenty-five NCAA Division I women's ice hockey athletes wore a sensor at night to monitor sleep quantity or quality (e.g., time asleep and sleep efficiency) and physiology (e.g., HR and HRV). During training and competitions (31 regular season and 7 postseason), athletes wore performance monitoring systems to assess workload demands (e.g., training impulse and TRIMP). As internal workload (TRIMP, Time >80% of HRmax, Average HR) during training or competition increased, nocturnal HRV decreased, HR increased, and Sleep Duration, Sleep Score, and Readiness Score decreased that night. Across the season, athletes experienced lower HRV, but exhibited longer sleep durations. Training Distance, Duration, Time >80% HRmax, Average HR, and TRIMP decreased, whereas competition Total Distance, Duration, and TRIMP increased across weeks throughout the season. There were differences across positions and season blocks when evaluating these data at the mesocycle level. Athletes slept longer before competition compared with training, but physiological data did not differ. Competitions had greater physiological demands than training. We speculate that the increased focus on sleep hygiene, as evidenced by the increase in sleep over the season, may have served as a recovery aid to combat physiological stress of accumulated demands of competitions that increased over time into postseason tournaments.

Female National Collegiate Athletic Association Division-I Athlete Injury Prediction by Vertical Countermovement Jump Force-Time Metrics.

ABSTRACT: Merrigan, JJ, Stone, JD, Kraemer, WJ, Vatne, EA, Onate, J, and Hagen, JA. Female National Collegiate Athletic Association Division-I athlete injury prediction by vertical countermovement jump force-time metrics. J Strength Cond Res 38(4): 783-786, 2024-Vertical countermovement jump (CMJ) assessments on force plates have been purported to screen for musculoskeletal injury risk (MSKI) but with little scientific support. Thus, this study aimed to identify associations and noncontact lower-body injury predictability with CMJ force-time metrics in female athletes. The study entailed a retrospective analysis of routine injury and performance monitoring from 155 female National Collegiate Athletics Association Division I athletes. Noncontact lower-body injuries included in analysis were confirmed by medical staff, occurred during competition or training, resulted in time loss from training, and occurred within 3 months following CMJ testing (2 maximal effort, no arm swing, jumps on dual force plates). A total of 44 injuries occurred within 3 months following CMJ baseline testing and resulted in an average of 24.5 missed days from training. Those who sustained an injury were more likely to sustain another injury (15 of 44 injuries [33.1%]; odds ratio = 3.05 [95% CI = 1.31-6.99]). For every 1-unit increase from the mean in eccentric mean power and minimum eccentric force, there was a decrease in odds of sustaining a MSKI. Despite high overall model accuracy (85.6%), the receiving operating characteristic area under the curve (65.9%) was unacceptable and the true positive rate (recall) was 0.0%. Thus, no injuries in the testing data set were correctly classified by the logistic regression model with CMJ force-time metrics as predictors. Baseline CMJ assessment may not be useful for noncontact lower-body musculoskeletal injury screening or predictability in National Collegiate Athletics Association female athletes.

Distinct mesenchymal cell states mediate prostate cancer progression.

In the complex tumor microenvironment (TME), mesenchymal cells are key players, yet their specific roles in prostate cancer (PCa) progression remain to be fully deciphered. This study employs single-cell RNA sequencing to delineate molecular changes in tumor stroma that influence PCa progression and metastasis. Analyzing mesenchymal cells from four genetically engineered mouse models (GEMMs) and correlating these findings with human tumors, we identify eight stromal cell populations with distinct transcriptional identities consistent across both species. Notably, stromal signatures in advanced mouse disease reflect those in human bone metastases, highlighting periostin's role in invasion and differentiation. From these insights, we derive a gene signature that predicts metastatic progression in localized disease beyond traditional Gleason scores. Our results illuminate the critical influence of stromal dynamics on PCa progression, suggesting new prognostic tools and therapeutic targets.

Whole-body photobiomodulation improves post-exercise recovery but does not affect performance or physiological response during maximal anaerobic cycling.

This study aims to examine the effects of acute whole-body photobiomodulation (wbPBM), applied pre-exercise, on bouts of anaerobic cycling (Wingate) performances. Forty-eight healthy, active males and females participated in this single-blind, randomized, crossover study. Participants visited the laboratory three times to complete repeat (4 ×) Wingate testing, with one week between each visit. All participants completed baseline testing during their first visit and randomly received either the wbPBM or placebo condition before testing on the second visit, followed by the opposite condition on the third visit. There were no significant condition × time interactions for any variable (peak power, average power, power decrement, lactate, heart rate, ratings of perceived exertion, heart rate variability (HRV), root-mean square of differences between R-R intervals (rMSSD), power in the high-frequency range (HF) average, power in the low-frequency range (LF) average, total power, LF/HF, or power in the very-low-frequency range average). A main condition effect was only noted for heart rate, where peak heart rate was significantly higher for wbPBM (145, 141-148 bpm) than placebo (143, 139-146 bpm; p = 0.006) and baseline testing (143, 140-146; p = 0.049) throughout the entire testing session (i.e., collapsed across all timepoints). Furthermore, HRV (rMSSD) the following morning after testing was significantly higher for the wbPBM session compared to placebo (p = 0.043). There were no differences in perceived recovery (p = 0.713) or stress (p = 0.978) scores between wbPBM and placebo. Implementing 20 min of wbPBM immediately prior to maximal bouts of anaerobic cycling did not improve performance (i.e., power output) or physiological responses (e.g., lactate). However, wbPBM elicited the ability to work at a higher heart rate throughout testing and seemed to enhance recovery through improved HRV the following morning.

Analyzing Force-Time Curves: Comparison of Commercially Available Automated Software and Custom MATLAB Analyses.

ABSTRACT: Merrigan, JJ, Stone, JD, Galster, SM, and Hagen, JA. Analyzing force-time curves: Comparison of commercially available automated software and custom MATLAB analyses. J Strength Cond Res 36(9): 2387-2402, 2022-With the growing prevalence of commercial force plate solutions providing automated force-time curve analysis, it is critical to understand the level of agreement across techniques. Thus, this study directly compared commercial and custom software analyses across force-time curves. Twenty-four male and female subjects completed 6 trials of countermovement, squat, and drop jumps, and isometric mid-thigh pulls on the same force plate. Vertical ground reaction forces were analyzed by automated software from Vald Performance, Hawkin Dynamics, and custom MATLAB scripts. Trials were visually assessed to verify proper landmark identifications. Systematic and proportional bias among analyses were compared via least products regressions, Bland-Altman plots, and percent error. Hawkin Dynamics had subtle differences in analysis procedures and demonstrated low percent errors across all tests (<3% error), despite demonstrating systematic and proportional bias for several metrics. ForceDecks demonstrated larger percent differences and greater biases for several metrics. These errors likely result from different identification of movement initiation, system weight, and integration techniques, which causes error to subsequent landmark identifications (e.g., braking/propulsive phases) and respective force-time metrics. Many metrics were in agreement between devices, such as isometric mid-thigh pull peak force consistently within 1 N across analyses, but some metrics are difficult and incomparable across software analyses (i.e., rate of force development). Overall, many metrics were in agreement across each commercial software and custom MATLAB analyses after visually confirming landmarks. However, because of inconsistencies, it is important to only compare metrics that are in agreement across software analyses when absolutely necessary.

Simplifying External Load Data in NCAA Division-I Men's Basketball Competitions: A Principal Component Analysis.

The primary purpose was to simplify external load data obtained during Division-I (DI) basketball competitions via principal component analysis (PCA). A secondary purpose was to determine if the PCA results were sensitive to load demands of different positional groups (POS). Data comprised 229 observations obtained from 10 men's basketball athletes participating in NCAA DI competitions. Each athlete donned an inertial measurement unit that was affixed to the same location on their shorts prior to competition. The PCA revealed two factors that possessed eigenvalues >1.0 and explained 81.42% of the total variance. The first factor comprised total decelerations (totDEC, 0.94), average speed (avgSPD, 0.90), total accelerations (totACC, 0.85), total mechanical load (totMECH, 0.84), and total jump load (totJUMP, 0.78). Maximum speed (maxSPD, 0.94) was the lone contributor to the second factor. Based on the PCA, external load variables were included in a multinomial logistic regression that predicted POS (Overall model, p < 0.0001; AUCcenters = 0.93, AUCguards = 0.88, AUCforwards = 0.80), but only maxSPD, totDEC, totJUMP, and totMECH were significant contributors to the model's success (p < 0.0001 for each). Even with the high significance, the model still had some issues differentiating between guards and forwards, as in-game demands often overlap between the two positions. Nevertheless, the PCA was effective at simplifying a large external load dataset collected on NCAA DI men's basketball athletes. These data revealed that maxSPD, totDEC, totJUMP, and totMECH were the most sensitive to positional differences during competitions. To best characterize competition demands, such variables may be used to individualize training and recovery regimens most effectively.

Comparisons of Countermovement Jump Force-Time Characteristics Among National Collegiate Athletic Association Division I American Football Athletes: Use of Principal Component Analysis.

ABSTRACT: Merrigan, JJ, Rentz, LE, Hornsby, WG, Wagle, JP, Stone, JD, Smith, HT, Galster, SM, Joseph, M, and Hagen, JA. Comparisons of countermovement jump force-time characteristics among NCAA Division I American football athletes: use of principal component analysis. J Strength Cond Res 36(2): 411-419, 2022-This study aimed to reduce the dimensionality of countermovement jump (CMJ) force-time characteristics and evaluate differences among positional groups (skills, hybrid, linemen, and specialists) within National Collegiate Athletic Association (NCAA) division I American football. Eighty-two football athletes performed 2 maximal effort, no arm-swing, CMJs on force plates. The average absolute and relative (e.g., power/body mass) metrics were analyzed using analysis of variance and principal component analysis procedures (p < 0.05). Linemen had the heaviest body mass and produced greater absolute forces than hybrid and skills but had lower propulsive abilities demonstrated by longer propulsive phase durations and greater eccentric to concentric mean force ratios. Skills and hybrid produced the most relative concentric and eccentric forces and power, as well as modified reactive strength indexes (RSIMOD). Skills (46.7 ± 4.6 cm) achieved the highest jump height compared with hybrid (42.8 ± 5.5 cm), specialists (38.7 ± 4.0 cm), and linemen (34.1 ± 5.3 cm). Four principal components explained 89.5% of the variance in force-time metrics. Dimensions were described as the (a) explosive transferability to concentric power (RSIMOD, concentric power, and eccentric to concentric forces) (b) powerful eccentric loading (eccentric power and velocity), (c) countermovement strategy (depth and duration), and (d) jump height and power. The many positional differences in CMJ force-time characteristics may inform strength and conditioning program designs tailored to each position and identify important explanatory metrics to routinely monitor by position. The overwhelming number of force-time metrics to select from may be reduced using principal component analysis methods, although practitioners should still consider the various metric's applicability and reliability.

Using Random Forest Regression to Determine Influential Force-Time Metrics for Countermovement Jump Height: A Technical Report.

ABSTRACT: Merrigan, JJ, Stone, JD, Wagle, JP, Hornsby, WG, Ramadan, J, Joseph, M, and Hagen, JA. Using random forest regression to determine influential force-time metrics for countermovement jump height: a technical report. J Strength Cond Res 36(1): 277-283, 2022-The purpose of this study was to indicate the most influential force-time metrics on countermovement jump (CMJ) height using multiple statistical procedures. Eighty-two National Collegiate Athletic Association Division I American football players performed 2 maximal-effort, no arm-swing, CMJs on force plates. The average absolute and relative (i.e., power/body mass) metrics were included as predictor variables, whereas jump height was the dependent variable within regression models (p < 0.05). Best subsets regression (8 metrics, R2 = 0.95) included less metrics compared with stepwise regression (18 metrics, R2 = 0.96), while explaining similar overall variance in jump height (p = 0.083). Random forest regression (RFR) models included 8 metrics, explained ∼93% of jump height variance, and were not significantly different than best subsets regression models (p > 0.05). Players achieved higher CMJs by attaining a deeper, faster, and more forceful countermovement with lower eccentric-to-concentric force ratios. An additional RFR was conducted on metrics scaled to body mass and revealed relative mean and peak concentric power to be the most influential. For exploratory purposes, additional RFR were run for each positional group and suggested that the most influential variables may differ across positions. Thus, developing power output capabilities and providing coaching to improve technique during the countermovement may maximize jump height capabilities. Scientists and practitioners may use best subsets or RFR analyses to help identify which force-time metrics are of interest to reduce the selectable number of multicollinear force-time metrics to monitor. These results may inform their training programs to maximize individual performance capabilities.

Utilization of Chest Pain Decision Aids in a Community Hospital Emergency Department: A Mixed-methods Implementation Study.

INTRODUCTION: Chest pain is a common reason for emergency department (ED) visits. Evidence-based decision aids assessing risk for an adverse cardiac event are underused in community hospital emergency care. This study explored the acceptability, barriers, facilitators, and potential strategies for implementation of the HEART Score risk stratification tool, accelerated diagnostic pathway, and shared decision-making visual aid with physicians and chest pain patients ages >45 in a community hospital ED. METHODS: Single center, mixed-methods study. (1) Physician semistructured interviews using The Consolidated Framework for Implementation Research for systematic analysis. (2) Patient and physician surveys. (3) 16-week intervention of physician training and pilot testing of decision aids with ED patients. RESULTS: Physician interviews (n = 19); key facilitators: electronic medical record decision support, ease of use, risk stratification and disposition support, and shared decision-making training. Key barriers: time constraints, patient ability, and/or willingness to participate in shared decision-making, lack of integration with medical record and change in practice workflow. Patient study participants (n = 184) with a survey response rate of 92% (n = 170). Most patients (85%) were satisfied with the shared decision-making visual aid. Physicians surveyed (n = 84) with a response rate of 50% (n = 42). Most physicians, 95% (n = 40), support use of the HEART Score, with limited acceptance of the shared decision-making visual aid of 57% (n = 24). CONCLUSIONS: Using evidence-based chest pain decision aids in a community hospital ED is feasible and acceptable. Key barriers and facilitators for implementation were identified. Further research in community hospitals is needed to verify findings, examine generalizability, and test implementation strategies.

The effect of omega-3 fatty acids on a biomarker of head trauma in NCAA football athletes: a multi-site, non-randomized study.

BACKGROUND: American-style football (ASF) athletes are at risk for cardiovascular disease (CVD) and exhibit elevated levels of serum neurofilament light (Nf-L), a biomarker of axonal injury that is associated with repetitive head impact exposure over the course of a season of competition. Supplementation with the w-3 fatty acid (FA) docosahexaenoic acid (DHA) attenuates serum Nf-L elevations and improves aspects of CVD, such as the omega-3 index (O3I). However, the effect of combining the w-3 FA eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA) with DHA on, specifically, serum Nf-L in ASF athletes is unknown. Therefore, this study assessed the effect of supplemental w-3 FA (EPA+DPA+DHA) on serum Nf-L, plasma w-3 FAs, the O3I, and surrogate markers of inflammation over the course of a season. METHODS: A multi-site, non-randomized design, utilizing two American football teams was employed. One team (n = 3 1) received supplementation with a highly bioavailablew-3 FA formulation (2000mg DHA, 560mg EPA, 320mg DPA, Mindset®, Struct Nutrition, Missoula, MT) during pre-season and throughout the regular season, while the second team served as the control (n = 35) and did not undergo supplementation. Blood was sampled at specific times throughout pre- and regular season coincident w ith changes in intensity, physical contact, and changes in the incidence and severity of head impacts. Group differences were determined via a mixed-model between-within subjects ANOVA. Effect sizes were calculated using Cohen's dfor all between-group differences. Significance was set a priori at p< .05. RESULTS: Compared to the control group, ASF athletes in the treatment group experienced large increases in plasma EPA (p < .001, d = 1.71) and DHA (p < .001, d = 2.10) which contributed to increases in the O3I (p < .001, d = 2.16) and the EPA:AA ratio (p = .001, d = 0.83) and a reduction in the w-6: w-3 ratio (p < .001, d = 1.80). w-3 FA supplementation attenuated elevations in Nf-L (p = .024). The control group experienced a significant increase in Nf-L compared to baseline at several measurement time points (T2, T3, and T4 [p range < .001 - .005, drange = 0.59-0.85]). CONCLUSIONS: These findings suggest a cardio- and neuroprotective effect of combined EPA+DPA+DHA w-3 FA supplementation in American-style football athletes. TRIAL REGISTRATION: This trial was registered with the ISRCTN registry ( ISRCTN90306741 ).

Applying Heart Rate Variability to Monitor Health and Performance in Tactical Personnel: A Narrative Review.

Human performance optimization of tactical personnel requires accurate, meticulous, and effective monitoring of biological adaptations and systemic recovery. Due to an increased understanding of its importance and the commercial availability of assessment tools, the use of heart rate variability (HRV) to address this need is becoming more common in the tactical community. Measuring HRV is a non-invasive, practical method for objectively assessing a performer's readiness, workload, and recovery status; when combined with additional data sources and practitioner input, it provides an affordable and scalable solution for gaining actionable information to support the facilitation and maintenance of operational performance. This narrative review discusses the non-clinical use of HRV for assessing, monitoring, and interpreting autonomic nervous system resource availability, modulation, effectiveness, and efficiency in tactical populations. Broadly, HRV metrics represent a complex series of interactions resulting from internal and external stimuli; therefore, a general overview of HRV applications in tactical personnel is discussed, including the influence of occupational specific demands, interactions between cognitive and physical domains, and recommendations on implementing HRV for training and recovery insights into critical health and performance outcomes.

Escherichia coli O121 outbreak associated with raw milk Gouda-like cheese in British Columbia, Canada, 2018.

BACKGROUND: In 2018, a Shiga toxin-producing Escherichia coli O121 outbreak that affected seven individuals was associated with raw milk Gouda-like cheese produced in British Columbia, Canada. OBJECTIVES: To describe the E. coli O121 outbreak investigation and recommend greater control measures for raw milk Gouda-like cheese. METHODS: Cases of E. coli O121 were identified through laboratory testing results and epidemiologic surveillance data. The cases were interviewed on exposures of interest, which were analyzed against Foodbook Report values for British Columbia. Environmental inspection of the dairy plant and the cheese products was conducted to ascertain a source of contamination. Whole genome multi-locus sequence typing (wgMLST) was performed on all positive E. coli O121 clinical and food isolates at the provincial laboratory. RESULTS: Four out of the seven cases consumed the same raw milk Gouda-like cheese between August and October 2018. The implicated cheese was aged longer than the required minimum of 60 days, and no production deficiencies were noted. One sample of the implicated cheese tested positive for E. coli O121. The seven clinical isolates and one cheese isolate matched by wgMLST within 6.5 alleles. CONCLUSION: Raw milk Gouda and Gouda-like cheese has been implicated in three previous Shiga toxin-producing E. coli outbreaks in North America. It was recommended product labelling to increase consumer awareness and thermization of milk to decrease the risk of illness associated with raw milk Gouda and Gouda-like cheese.

Assessing the Accuracy of Popular Commercial Technologies That Measure Resting Heart Rate and Heart Rate Variability.

Commercial off-the shelf (COTS) wearable devices continue development at unprecedented rates. An unfortunate consequence of their rapid commercialization is the lack of independent, third-party accuracy verification for reported physiological metrics of interest, such as heart rate (HR) and heart rate variability (HRV). To address these shortcomings, the present study examined the accuracy of seven COTS devices in assessing resting-state HR and root mean square of successive differences (rMSSD). Five healthy young adults generated 148 total trials, each of which compared COTS devices against a validation standard, multi-lead electrocardiogram (mECG). All devices accurately reported mean HR, according to absolute percent error summary statistics, although the highest mean absolute percent error (MAPE) was observed for CameraHRV (17.26%). The next highest MAPE for HR was nearly 15% less (HRV4Training, 2.34%). When measuring rMSSD, MAPE was again the highest for CameraHRV [112.36%, concordance correlation coefficient (CCC): 0.04], while the lowest MAPEs observed were from HRV4Training (4.10%; CCC: 0.98) and OURA (6.84%; CCC: 0.91). Our findings support extant literature that exposes varying degrees of veracity among COTS devices. To thoroughly address questionable claims from manufacturers, elucidate the accuracy of data parameters, and maximize the real-world applicative value of emerging devices, future research must continually evaluate COTS devices.

Changes in Maximal Strength and Home Run Performance in NCAA Division I Baseball Players Across 3 Competitive Seasons: A Descriptive Study.

The purpose of this longitudinal, descriptive study was to observe changes in maximal strength measured via isometric clean grip mid-thigh pull and home runs (total and home runs per game) across three years of training and three competitive seasons for four National Collegiate Athletic Association (NCAA) Division 1 baseball players. A one-way repeated measures analysis of variance (ANOVA) was performed, revealing significant univariate effects of time for peak force (PF) (p = 0.003) and peak force allometrically scaled (PFa) (p = 0.002). Increases in PF were noted from season 1 to season 2 (p = 0.031) and season 3 (p = 0.004), but season 2 was not significantly different than season 3 (p = 0.232). Additionally, increases in PFa were noted from season 1 to season 2 (p = 0.010) and season 3 (p < 0.001), but season 2 was not significantly different than season 3 (p = 0.052). Home runs per game rose from the 2009 (0.32) to 2010 season (1.35) and dropped during the 2011 season (1.07). A unique aspect of the study involves 2010 being the season in which ball-bat coefficient of restitution (BBCOR) bats were introduced to the NCAA competition.

Monitoring Neuromuscular Performance in Military Personnel.

A necessarily high standard for physical readiness in tactical environments is often accompanied by high incidences of injury due to overaccumulations of neuromuscular fatigue (NMF). To account for instances of overtraining stimulated by NMF, close monitoring of neuromuscular performance is warranted. Previously validated tests, such as the countermovement jump, are useful means for monitoring performance adaptations, resiliency to fatigue, and risk for injury. Performing such tests on force plates provides an understanding of the movement strategy used to obtain the resulting outcome (e.g., jump height). Further, force plates afford numerous objective tests that are valid and reliable for monitoring upper and lower extremity muscular strength and power (thus sensitive to NMF) with less fatiguing and safer methods than traditional one-repetition maximum assessments. Force plates provide numerous software and testing application options that can be applied to military's training but, to be effective, requires the practitioners to have sufficient knowledge of their functions. Therefore, this review aims to explain the functions of force plate testing as well as current best practices for utilizing force plates in military settings and disseminate protocols for valid and reliable testing to collect key variables that translate to physical performance capacities.

Evaluations of Commercial Sleep Technologies for Objective Monitoring During Routine Sleeping Conditions.

PURPOSE: The commercial market is saturated with technologies that claim to collect proficient, free-living sleep measurements despite a severe lack of independent third-party evaluations. Therefore, the present study evaluated the accuracy of various commercial sleep technologies during in-home sleeping conditions. MATERIALS AND METHODS: Data collection spanned 98 separate nights of ad libitum sleep from five healthy adults. Prior to bedtime, participants utilized nine popular sleep devices while concurrently wearing a previously validated electroencephalography (EEG)-based device. Data collected from the commercial devices were extracted for later comparison against EEG to determine degrees of accuracy. Sleep and wake summary outcomes as well as sleep staging metrics were evaluated, where available, for each device. RESULTS: Total sleep time (TST), total wake time (TWT), and sleep efficiency (SE) were measured with greater accuracy (lower percent errors) and limited bias by Fitbit Ionic [mean absolute percent error, bias (95% confidence interval); TST: 9.90%, 0.25 (-0.11, 0.61); TWT: 25.64%, -0.17 (-0.28, -0.06); SE: 3.49%, 0.65 (-0.82, 2.12)] and Oura smart ring [TST: 7.39%, 0.19 (0.04, 0.35); TWT: 36.29%, -0.18 (-0.31, -0.04); SE: 5.42%, 1.66 (0.17, 3.15)], whereas all other devices demonstrated a propensity to over or underestimate at least one if not all of the aforementioned sleep metrics. No commercial sleep technology appeared to accurately quantify sleep stages. CONCLUSION: Generally speaking, commercial sleep technologies displayed lower error and bias values when quantifying sleep/wake states as compared to sleep staging durations. Still, these findings revealed that there is a remarkably high degree of variability in the accuracy of commercial sleep technologies, which further emphasizes that continuous evaluations of newly developed sleep technologies are vital. End-users may then be able to determine more accurately which sleep device is most suited for their desired application(s).

Spontaneous Regression and Resolution of Breast Implant-Associated Anaplastic Large Cell Lymphoma: Implications for Research, Diagnosis and Clinical Management.

BACKGROUND: First described in 1997, breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) was recognised by the World Health Organisation in 2016 as a specific disease. It typically presents as a late seromacontaining atypical, monoclonal T cells which are CD30+ and anaplastic lymphoma kinase negative. Until recently, it was thought that the disease was very rare. However, it is being diagnosed increasingly frequently with 56 cases confirmed in Australia by September 2017 and the estimated incidence revised from 1 in 300,000 to between 1 in 1000 and 1 in 10,000 patients with bilateral implants. There is debate about the spectrum of BIA-ALCL. According to the current WHO classification, BIA-ALCL is a cancer in all cases. Treatment guidelines require that it is treated urgently with a minimum of bilateral removal of implants and capsulectomies. Whilst acknowledging the disease has been under diagnosed in the past, with some notable exceptions the BIA-ALCL literature has given scant attention to the epidemiological evidence. Now that it is known that the disease may occur in up to 1 in 1000 patients with a median of 7.5 years from implantation to diagnosis, understanding it in its epidemiological context is imperative. The epidemiology of cancer and lymphoma in women with breast implants strongly suggests that most patients do not have a cancer that will inevitably progress without treatment but instead a self-limiting lympho-proliferative disorder. Although the possibility of spontaneous regression has been raised and the observation made that treatment delay did not seem to increase the risk of spread, the main objection to the lympho-proliferative hypothesis has been the lack of documented cases of spontaneous regression or resolution. Because all cases currently are considered malignant and treated urgently, only case report evidence, interpreted in the proper epidemiological context, is likely to be available to challenge this thinking. METHODS AND RESULTS: New observations and interpretation of the epidemiology of BIA-ALCL are made. These are supported by the presentation of two cases, which to the best of our knowledge comprise the first documented evidence of spontaneous regression and spontaneous resolution of confirmed BIA-ALCL. CONCLUSIONS: The epidemiology of the disease strongly suggests that the vast majority of cases are not a cancer that will inevitably progress without treatment. The findings presented in the manuscript provide supportive clinical evidence. Consequently, an alternative view of BIA-ALCL with implications for research, diagnosis and clinical management needs to be considered. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

An analysis of antibiotic prescribing practices for enteric bacterial infections within FoodNet Canada sentinel sites.

OBJECTIVES: Understanding the current state of antibiotic treatment guidelines and prescribing practices for bacterial enteric infections is critical to inform antibiotic stewardship initiatives. This study aims to add to the current understanding through three objectives: (i) to identify and summarize published treatment guidelines for bacterial enteric infections; (ii) to describe observed antibiotic prescribing practices for bacterial enteric infections across three sentinel sites in Canada; and (iii) to assess concordance between observed antibiotic prescribing and treatment guidelines. METHODS: An environmental scan of treatment guidelines for bacterial enteric infections was conducted and recommendations were collated. A descriptive analysis of cases of bacterial enteric illnesses captured in FoodNet Canada's sentinel site surveillance system between 2010 and 2018 was performed. Antibiotic-use data were self-reported by cases via an enhanced questionnaire. RESULTS: Ten treatment guidelines were identified in the environmental scan. There was substantial variation between guidelines for both when to prescribe antibiotics and which antibiotics were recommended. Of the 5877 cases of laboratory-confirmed bacterial enteric illness in the three sites, 49% of cases reported having received an antibiotic prescription. Of particular significance was the finding that 21% of verotoxigenic Escherichia coli cases received a prescription. Of the 17 antibiotics recommended in the guidelines, 14 were used in practice. In addition to these, 18 other antibiotics not included in any of the guidelines reviewed were also prescribed. CONCLUSIONS: Our study suggests that a substantial proportion of enteric bacterial infections in Canada are prescribed antibiotics. These findings highlight the need to standardize treatment guidelines for enteric illnesses and could be used to inform future stewardship programme development.

Test and Evaluation of Heart Rate Derived Core Temperature Algorithms for Use in NCAA Division I Football Athletes.

The purpose of this study was to assess the validity of utilizing heart rate to derive an estimate of core body temperature in American Football athletes. This was evaluated by combining commercially available Zephyr Bioharness devices, which includes an embedded estimated core temperature (ECT) algorithm, and an ingestible radio frequency core temperature pill during the highest heat injury risk timepoint of the season, summer training camp. Results showed a concordance of 0.643 and 78% of all data points fell within +/-1.0 °F. When the athletes were split into Upper (>/=6.0%) and Lower (<6.0%) body composition groups, there was a statistical improvement in accuracy with the Upper Body Fat% reaching 0.834 concordance and 93% of all values falling within +/-1.0 °F of the Gold Standard. Results suggest that heart rate derived core temperature assessments are a viable tool for heat stress monitoring in American football, but more work is required to improve on accuracy based on body composition.