Poisson Rates Research Articles

Lower extremity injury and return to sports of elite taekwondo athletes

Abstract Objective We attempted to analyze the characteristics of lower-extremity injuries that occur during training based on the sex and weight class of elite taekwondo (TKD) athletes and the effect of pain scores on the return to sports periods (RTSP). Methods and Methods: We included 198 elite TKD athletes who participated in January–December 2023 and were trained in Korea. Injury incidence rates (IIR) were expressed as Poisson rates with 95% confidence intervals per 1,000 h of training. One-way analysis of variance was conducted to determine the pain score and RTSP according to sex, weight, and injury type. In addition, we performed simple linear regression to determine the effects of pain score on the RTSP. Results The lower-extremities IIR was 2.45 injuries per 1000 training hours, including 0.77 contact and 1.68 non-contact injuries. The IIR was lower in male than in female athletes (p<0.001), the most common injuries occurred in the ankle (0.78) and knee(0.53). In addition, the ligament (0.99) and muscle (0.70) were the most common injury types. All athletes demonstrated significant differences in pain scores (p<0.001) and RTSP (p<0.001) based on the injury type. In addition, we observed a significant difference between the pain score (p<0.001) and RTSP (p=0.004) based on sex. For every 1-point increase in pain score, all athletes had a 1.43-day increase in RTSP. Conclusion These results can be used as data to develop injury prevention programs for TKD athletes and to determine their RTSP.

Duty Cycle Scheduling in Wireless Sensor Networks Using an Exploratory Strategy-Directed MADDPG Algorithm

This paper presents an in-depth study of the application of Multi-Agent Deep Deterministic Policy Gradient (MADDPG) algorithms with an exploratory strategy for duty cycle scheduling (DCS) in the wireless sensor networks (WSNs). The focus is on optimizing the performance of sensor nodes in terms of energy efficiency and event detection rates under varying environmental conditions. Through a series of simulations, we investigate the impact of key parameters such as the sensor specificity constant α and the Poisson rate of events on the learning and operational efficacy of sensor nodes. Our results demonstrate that the MADDPG algorithm with an exploratory strategy outperforms traditional reinforcement learning algorithms, particularly in environments characterized by high event rates and the need for precise energy management. The exploratory strategy enables a more effective balance between exploration and exploitation, leading to improved policy learning and adaptation in dynamic and uncertain environments. Furthermore, we explore the sensitivity of different algorithms to the tuning of the sensor specificity constant α, revealing that lower values generally yield better performance by reducing energy consumption without significantly compromising event detection. The study also examines the algorithms' robustness against the variability introduced by different event Poisson rates, emphasizing the importance of algorithm selection and parameter tuning in practical WSN applications. The insights gained from this research provide valuable guidelines for the deployment of sensor networks in real-world scenarios, where the trade-off between energy consumption and event detection is critical. Our findings suggest that the integration of exploratory strategies in MADDPG algorithms can significantly enhance the performance and reliability of sensor nodes in WSNs.

An Adaptive and Scalable Multi-Object Tracker Based on the Non-Homogeneous Poisson Process

This paper proposes a new adaptive framework for tracking multiple objects in the presence of data association uncertainty and heavy clutter, either with or without knowledge of the measurement rates and/or target shapes. Built upon an online Gibbs sequential Markov chain Monte Carlo sampling scheme, the adaptive tracker is Bayesian optimal and robust, requiring no additional approximations or measurement partition steps. With a non-homogeneous Poisson process measurement model, our tracker can tackle the data association task with linear computational complexity. Meanwhile, we study generalised inverse Gaussian and inverse Wishart distributions for modelling Poisson rates and object shapes, respectively; these prior models ensure closed-form full conditionals in our online Gibbs sampling steps, under which object states and shapes can be jointly estimated with associations and Poisson rates in a parallel fashion. Furthermore, a fast Rao-Blackwellisation scheme for linear Gaussian dynamics is designed and demonstrated to significantly improve both tracking efficiency and accuracy. We validate the efficacy of our method on real and simulated data.

EPIDEMIOLOGIA DAS LESÕES ESPORTIVAS EM ATLETAS COREANAS DE ESGRIMA DE ELITE: UM ESTUDO PROSPECTIVO DE COORTE

ABSTRACT Objectives: We aimed to assess the risk of injury associated with training activities of Korean elite female fencing athletes by weapon category. Methods: We prospectively collected 2021 data on 80 elite female fencing athletes at the Korean Training Center. Injury incidence rates were expressed as Poisson rates with a 95% confidence interval. We used χ2 tests to compare injury locations and recovery times by weapon category. Results: A total of 233 injuries were recorded, averaging 3.27 (95% CI, 2.86–3.72) injuries per 1,000 training hours. The sabre had the highest injury incidence rate, followed by the epee and the foil. Injuries to fencing athletes were the most common in the lower extremities (46.35%), followed by the upper extremities (24.03%), trunk (20.17%), and head and neck area (9.44%). The weapon category did not affect the body regions (p=0.425). However, recovery time differed significantly by body region (p=0.021). Conclusions: The weapon category was found to affect the injury incidence rate. In addition, recovery time varied depending on body region. Further research is needed to clarify these results. Level of evidence II; Therapeutic studies - investigation of treatment results.

Hypothesis Testing of Poisson Rates in COVID-19 Offspring Distributions

Hypothesis Testing of Poisson Rates in COVID-19 Offspring Distributions

Unequal allocation of sample/event sizes with considerations of sampling cost for testing equality, non-inferiority/superiority, and equivalence of two Poisson rates.

For non-inferiority/superiority and equivalence tests of two Poisson rates, the determination of the required number of sample sizes has been studied but the studies for the number of events to be observed are very limited. To fill the gap, the present study first is aimed toward determining the number of events to be observed for testing non-inferiority/superiority and equivalence of two Poisson rates, respectively. Also, considering the cost for each event, the second purpose is to apply an exhaustive search to find the unequal but optimal allocation of events for each group such that the budget is minimal for a user-specified power level, or the statistical power is maximal for a user-specified budget. Four R Shiny apps were developed to obtain the number of events needed for each group. A simulation study showed the proposed approach to be valid in terms of Type I error and statistical power. A comparison of the proposed approach with extant methods from various disciplines was performed, and an illustrative example of comparing the adverse reactions to the COVID-19 vaccines was demonstrated. By applying the proposed approach, researchers also can estimate the most economical number of subjects or time intervals after determining the number of events.

Evaluation of "Care Plus," A Multidisciplinary Program to Improve Population Health for Patients With High Utilization.

With rising health care costs, health systems have adopted alternative care models targeting high-need, high-cost patients to improve chronic disease management and population health. Intensive primary care teams may reduce health care utilization by tackling medical and psychosocial needs specific to this patient population. This study presents health care utilization trends from a high-intensity primary care program that employs a multidisciplinary team (including clinicians, psychologists, pharmacists, chaplaincy, and community health workers) and community partnerships. Using descriptive statistics and Poisson rates of differences, this study evaluates patient and utilization characteristics of those enrolled (n = 341) versus declined (n = 54) program participation from 2013 to 2020. Both enrolled and declined patients experienced significant reduction in emergency department and inpatient utilization, but differences between enrolled and declined patients were not statistically significant. Programs aimed at decreasing health care utilization for high-need, high-cost, medically complex patients may be best supported by interventions that simultaneously address social and behavioral health needs.

Extreme Compressed Sensing of Poisson Rates from Multiple Measurements.

Compressed sensing (CS) is a signal processing technique that enables the efficient recovery of a sparse high-dimensional signal from low-dimensional measurements. In the multiple measurement vector (MMV) framework, a set of signals with the same support must be recovered from their corresponding measurements. Here, we present the first exploration of the MMV problem where signals are independently drawn from a sparse, multivariate Poisson distribution. We are primarily motivated by a suite of biosensing applications of microfluidics where analytes (such as whole cells or biomarkers) are captured in small volume partitions according to a Poisson distribution. We recover the sparse parameter vector of Poisson rates through maximum likelihood estimation with our novel Sparse Poisson Recovery (SPoRe) algorithm. SPoRe uses batch stochastic gradient ascent enabled by Monte Carlo approximations of otherwise intractable gradients. By uniquely leveraging the Poisson structure, SPoRe substantially outperforms a comprehensive set of existing and custom baseline CS algorithms. Notably, SPoRe can exhibit high performance even with one-dimensional measurements and high noise levels. This resource efficiency is not only unprecedented in the field of CS but is also particularly potent for applications in microfluidics in which the number of resolvable measurements per partition is often severely limited. We prove the identifiability property of the Poisson model under such lax conditions, analytically develop insights into system performance, and confirm these insights in simulated experiments. Our findings encourage a new approach to biosensing and are generalizable to other applications featuring spatial and temporal Poisson signals.

Foot and Ankle Injuries in Elite Taekwondo Athletes: A 4-Year Descriptive Analysis.

Background:Foot and ankle injuries are a common but underestimated problem in taekwondo. Detailed data on injury incidence rates (IIRs), patterns, and injury mechanism are missing.Purpose:The primary aims were to evaluate the prevalence of foot and ankle injuries and the exposure-adjusted IIR of elite taekwondo athletes during matches while training (ie, sparring) and in competitions. The secondary aims were to evaluate injury site, type, sport-specific mechanism, and time loss.Study Design:Descriptive epidemiology study.Methods:Athletes from a single national Olympic taekwondo training center were assessed prospectively for foot and ankle injuries over 4 years (between January 1, 2016, and December 31, 2019). Data were collected regarding number and type of injuries, anatomic location, and total exposure time during training and competition for each athlete. Injury mechanism and dominant foot were assessed via personal interview. Time loss from sport was analyzed retrospectively. The injury prevalence and IIR were calculated. Correlation between mechanism and injury type, location, and dominant foot was evaluated. Time loss according to location and injury type was assessed. The chi-square test and Fisher exact test were used to test for differences in sex, age, and taekwondo experience and for comparison of injury location and type, injury mechanism, and side dominance, respectively. Training and competition IIRs and prevalence were calculated with 95% CIs (for Poisson rates).Results:From an initial 107 athletes, 79 (73.8%) were included in the final data set. Of these athletes, 38 were injured (n = 112 injuries) for a prevalence of 48.1% (95% CI, 43%-52%). The overall IIR of the ankle joint was 13.14 injuries per 1000 athletes (95% CI, 1.5-25.9) and was significantly higher during competition versus training (P < .001). Ankle joint injuries were most common (n = 71; 63%). Significantly more noncontact versus contact ankle ligament injuries (n = 46; 83%) occurred (P < .001). The forefoot (n = 18; 66%) was mainly affected by contact injuries (P < .001). Time loss was the highest for midfoot fractures (mean ± SD, 23.0 ± 0.6 days; range, 23-24 days).Conclusion:Noncontact ligamentous ankle injuries were most common, with a higher incidence during competition. Improvement of strength, endurance, and postural stability under strain is recommended for prevention.

Type of injury and recovery time in elite adolescent Korean judo athletes: An epidemiological study

We aimed to assess the risk of injury associated with training activities in a population of elite adolescent judo athletes, expected to represent South Korea. From 2019, we prospectively collected data on elite adolescent judo athletes at the Korean Training Center. The athletes were assessed by sports medicine doctors, and data were stratified according to sex, weight class, and injury location. We used χ2 tests to compare groups. Injury rates were expressed as Poisson rates with 95% confidence intervals. One-way analysis of variance was used to investigate the pain score and recovery time due to type of injury. The study included 240 elite adolescent judo athletes whose 617 injuries (annual average, 2.57 injuries/athlete) were recorded. When all athletes were considered, most injuries occurred in the lower extremities (39.71%), followed by the upper extremities (36.63%), trunk (16.69%), and head and neck area (6.97%). Recovery time significantly differed according to the body regions in the weight classes. The pain score and recovery time according to the type of injury were significantly different. When the pain score decreased by 1, the recovery time decreased by about 1.47 days. In all weight classes, female athletes had a higher injury rate than male athletes; both male and female athletes had different recovery time depending on their weight class. The type of injury influenced the pain score and recovery time, with pain score being associated with recovery time.

Injuries and time loss in elite judo athletes: a Korean prospective cohort study.

Few epidemiological studies have investigated pain and time loss due to sports injury. We analyzed the specific patterns of injury among Korean elite judo athletes and examined the effects of pain on time loss. We also assessed the association between the type of injury and time loss. We prospectively collected data on elite judo athletes at the Korean Training Center for the year 2019. The athletes were assessed by sports medicine doctors, and data were stratified according to sex, weight class, and injury location. We used χ2 tests to compare groups. Injury rates were expressed as Poisson rates with 95% confidence intervals. One-way analysis of variance was used to investigate the pain scores and time losses due to sports injury. The study included 232 athletes whose 606 injuries (annual average, 2.61 injuries/athlete) were recorded. Female athletes had higher injury rates than male athletes. Overall, most injuries occurred in the lower extremities (38.12%), followed by the upper extremities (36.80%), trunk (17.66%), and head and neck area (7.43%). Injury severity significantly differed according to the body regions in the weight classes. The pain score and time loss differed significantly according to the type of injury. When the pain score increased by 1, the time loss increased by approximately 1.47 days. Among all weight classes, female athletes had a higher injury rate than male athletes. The pain score and time loss varied depending on the type of injury, with pain score being associated with time loss.

Injuries in female and male elite Korean rowing athletes: anepidemiological study.

This study aimed to determine the patterns of injury associated with training activities in elite South Korean rowing athletes training for the Olympic Games. Data were prospectively collected between 2010 and 2019 at the Korea National Training Center in South Korea. Three sports medicine doctors assessed athletes, and the data were stratified according to sex, rowing style, weight class, site of injury, and severity of injury. The groups were compared using the c 2 test. The 95 % confidence interval with Poisson rates and exact Poisson test were used for comparison of rates. In total 514 injuries were recorded during the study period, with an average of 2.86 injuries per athlete annually; among these, over half (57.8 %) were mild injuries. Most injuries occurred in the lower extremities (42.0 %), followed by the trunk (30.2 %), the upper extremities (24.9 %), and the head and neck area (2.9 %). Weight class was significantly associated with severity of injury in all rowing athletes (p < 0.001), for both male and female rowing athletes (p = 0.006 and p = 0.014, respectively). Lightweight male athletes demonstrated higher incidence rate of injury than open-weight male athletes (p < 0.001). On the contrary, lightweight female athletes demonstrated lower incidence rates of injury than open-weight female athletes (p < 0.001). These findings on the incidence of training injuries and patterns based on rowing styles, sexes, and weight classes may elucidate the circumstances leading to injuries in elite Korean rowing athletes. Furthermore, these findings may contribute to the development of programs to enhance athletic performance and reduce the incidence of sports injuries.

Injuries and Rapid Weight Loss in Elite Adolescent Taekwondo Athletes: A Korean Prospective Cohort Study

Abstract Objectives To report injury patterns associated with training activities of elite adolescent Taekwondo athletes who are expected to represent South Korea in the future. Methods Beginning in 2019, we prospectively collected data on elite adolescent Taekwondo athletes at the Korean Training Center. The athletes were assessed by sports medicine doctors, and data were stratified according to sex, weight class, injury location, injuries during the weight loss period, and weight loss method. We used χ2 tests were used to compare groups. Injury rates were expressed as Poisson rates with 95% confidence intervals. Results There were 117 male and 102 female elite adolescent Taekwondo athletes. The mean weight loss among athletes was 3.37 (±1.23) kg, and the mean duration of weight loss was 7.53 (±3.40) days. In general, all athletes used similar weight loss methods. We recorded 846 injuries (annual average, 3.98 injuries/athlete). In general, female athletes had higher injury rates than their male counterparts. Additionally, the athletes had significantly higher injury rates during weight loss periods than during other periods of training. When all athletes were considered, most injuries occurred in the lower extremities (63.2%), followed by the trunk (14.2%), upper extremities (16.3%), and the head and neck area (6.3%). The injury severity significantly influenced the body regions in weight categories. Conclusion Rapid weight loss is related to the incidence of sports damage in athletes. Most injuries occur during weight loss periods in South Korean elite adolescent Taekwondo athletes. Moreover, the injury rate and injury severity depends on weight class.

Hormonal Contraception Effects on Pulmonary Function in Adolescents with Cystic Fibrosis.

Estrogens are suspected to have a negative effect on pulmonary function in women with cystic fibrosis (CF). The aim of our study was to investigate, in a CF adolescent population, the effect of hormonal contraception (HC) on lung function by assessing the forced expiratory volume in 1second (FEV1), the number of exacerbations of pulmonary condition, and antibiotic use. DESIGN, SETTING, PARTICIPANTS, INTERVENTIONS, AND MAIN OUTCOME MEASURES: We conducted a cohort retrospective chart review of girls from age 13 to 18years old who were followed in the CF clinic of a university hospital center. Wilcoxon rank sum test with continuity correction, 2-sample t test, conditional test of Poisson rates, and χ2 test were conducted to identify differences in results between adolescents with or without use of HC for the following outcomes: FEV1, use of antibiotics by nebulizer, and hospital admission for exacerbations of pulmonary condition. Among 127 adolescents, 64/127 (50.4%)took HC; 12/127 (9%) continuously had been taking HC over 3years. For girls taking HC for more than 3years, FEV1 at 18years old was significantly higher than for girls who had never taken HC (85.17% vs 71.05%; P=.043). However, there was no difference in the number of hospital admissions for exacerbation of pulmonary condition between these 2 groups (P=.057). There was no difference between HC vs non-HC users in the percent of patients taking antibiotics by nebulizer over the 6years of follow-up. Our study suggests that in adolescents with CF, HC has no deleterious effects on the FEV1. Further prospective studies could be done to confirm these results.

Measuring vaccine effectiveness against persistent HPV infections: a comparison of different statistical approaches

BackgroundPersistent high-risk human papillomavirus (HPV) infection is endorsed by the World Health Organization as an intermediate endpoint for evaluating HPV vaccine effectiveness/efficacy. There are different approaches to estimate the vaccine effectiveness/efficacy against persistent HPV infections.MethodsWe performed a systematic literature search in Pubmed to identify statistical approaches that have been used to estimate the vaccine effectiveness/efficacy against persistent HPV infections. We applied these methods to data of a longitudinal observational study to assess their performance and compare the obtained vaccine effectiveness (VE) estimates.ResultsOur literature search identified four approaches: the conditional exact test for comparing two independent Poisson rates using a binomial distribution, Generalized Estimating Equations for Poisson regression, Prentice Williams and Peterson total time (PWP-TT) and Cox proportional hazards regression. These approaches differ regarding underlying assumptions and provide different effect measures. However, they provided similar effectiveness estimates against HPV16/18 and HPV31/33/45 persistent infections in a cohort of young women eligible for routine HPV vaccination (range VE 93.7–95.1% and 60.4–67.7%, respectively) and seemed robust to violations of underlying assumptions.ConclusionsAs the rate of subsequent infections increased in our observational cohort, we recommend PWP-TT as the optimal approach to estimate the vaccine effectiveness against persistent HPV infections in young women. Confirmation of our findings should be undertaken by applying these methods after longer follow-up in our study, as well as in different populations.

Stochastic thermodynamics of all-to-all interacting many-body systems

We provide a stochastic thermodynamic description across scales for N identical units with all-to-all interactions that are driven away from equilibrium by different reservoirs and external forces. We start at the microscopic level with Poisson rates describing transitions between many-body states. We then identify an exact coarse graining leading to a mesoscopic description in terms of Poisson transitions between system occupations. We proceed studying macroscopic fluctuations using the Martin–Siggia–Rose formalism and large deviation theory. In the macroscopic limit (N → ∞), we derive the exact nonlinear (mean-field) rate equation describing the deterministic dynamics of the most likely occupations. We identify the scaling of the energetics and kinetics ensuring thermodynamic consistency (including the detailed fluctuation theorem) across microscopic, mesoscopic and macroscopic scales. The conceptually different nature of the ‘Shannon entropy’ (and of the ensuing stochastic thermodynamics) at different scales is also outlined. Macroscopic fluctuations are calculated semi-analytically in an out-of-equilibrium Ising model. Our work provides a powerful framework to study thermodynamics of nonequilibrium phase transitions.

Zero-inflated Poisson factor model with application to microbiome read counts.

Dimension reduction of high-dimensional microbiome data facilitates subsequent analysis such as regression and clustering. Most existing reduction methods cannot fully accommodate the special features of the data such as count-valued and excessive zero reads. We propose a zero-inflated Poisson factor analysis model in this paper. The model assumes that microbiome read counts follow zero-inflated Poisson distributions with library size as offset and Poisson rates negatively related to the inflated zero occurrences. The latent parameters of the model form a low-rank matrix consisting of interpretable loadings and low-dimensional scores that can be used for further analyses. We develop an efficient and robust expectation-maximization algorithm for parameter estimation. We demonstrate the efficacy of the proposed method using comprehensive simulation studies. The application to the Oral Infections, Glucose Intolerance, and Insulin Resistance Study provides valuable insights into the relation between subgingival microbiome and periodontaldisease.

Confidence intervals for the ratio of two independent Poisson rates: Parametric bootstrap, modified asymptotic, and approximate-estimate approaches.

We propose four confidence intervals for the ratio of two independent Poisson rates. We apply a parametric bootstrap approach, two modified asymptotic results, and we propose an ad-hoc approximate-estimate method to construct confidence intervals. We justify the correctness of the proposed methods asymptotically in the case of non-rare events (when the Poisson rates are large). We also compare the proposed confidence intervals with some recommended ones in the case of rare events (when the Poisson rates are small) via an extensive simulation study. The results show that the proposed modified asymptotic and the approximate-estimate confidence intervals perform reasonably well in terms of coverage probability and average length.

Control charts for monitoring the ratio of two Poisson rates

AbstractIn this paper, we are concerning in monitoring the ratio ρ of two Poisson rates by control charts. Let X and Y be two independent Poisson random variables with means λ1 and λ2=λ1/ρ, respectively. The study considers that only individual observations Xi and Yi are available at each sampling time i. The performance in detecting shifts on the ratio ρ using several statistics, some based on normalized transformations, is evaluated by an extensive simulation study. Two types of control charts, Shewhart and exponentially weighted moving average (EWMA), are considered. The one‐sided control chart with upper control limit (UCL) is applied so that we are focusing on detecting when the ratio ρ shifted to higher rate in this paper. The results pointed out that EWMA control chart is a better alternative. Some guidelines indicating which statistics yield best performance are proposed for the practitioners.

Gauging the influence of increased search effort on reporting rates of bottlenose dolphin (Tursiops truncatus) strandings following the deepwater horizon oil spill.

The co-occurrence of the Deepwater Horizon oil spill and the northern Gulf of Mexico cetacean Unusual Mortality Event have raised questions about the stability of inshore bottlenose dolphin (Tursiops truncatus) populations throughout the region. Several factors could have contributed to the ongoing event, but little attention has been paid to the potential effects of increased search effort and reporting of strandings associated with oil spill response activities, which were widespread for an extended period. This study quantified the influence of increased search effort by estimating the number of bottlenose dolphin strandings reported by oil spill responders and comparing monthly stranding rates with and without response-related records. Results showed that response teams reported an estimated 58% of strandings during the Active Response period within the study area. Comparison of Poisson rates tests showed that when responder-influenced stranding records were removed, the monthly stranding rates from the Active Response period (May 2010 –April 2014) were similar to the Post-Removal Actions Deemed Complete period (May 2013 –March 2015) (e.g., p = 0.83 for remote areas in Louisiana). Further, analyses using the Getis-Ord Gi* spatial statistic showed that when response-related stranding reports were removed from the Active Response period, significant spatial clustering of strandings (p < 0.05) was reduced by 48% in coastal Louisiana. Collectively, these results suggest that increased search effort resulting from the Deepwater Horizon oil spill response throughout remote portions of the Unusual Mortality Event geographic region had the capacity to increase reporting and recovery of marine mammal strandings to unusually high levels. To better understand how stranding data relates to actual mortality, more work is needed to quantify dolphin population size, population trends, and carcass detection rates including the role of search effort. This is vital for understanding the status of a protected species within the northern Gulf of Mexico.