Technical Variables Research Articles

PATH-46. DETECTION OF CDKN2A/B HOMOZYGOUS DELETION BY DNA METHYLATION AND DNA NEXT GENERATION SEQUENCING: A COMPARISON

Abstract CDKN2A/B homozygous deletion status is critical for grading of several central nervous system (CNS) tumors, including IDH mutant astrocytoma, pleomorphic xanthoastrocytoma, and meningioma. CDKN2A/B status can be assed using variety of methods, but the accuracy varies due to technical and analytical variables. Here we sought to compare sensitivity of CDKN2A/B homozygous deletion detection by NGS and DNA methylation array derived copy number analysis. We retrospectively analyzed 100 CNS tumors diagnosed at NYU Langone Health between 2020 and 2023. All tumors were profiled by whole genome DNA methylation profiling using the Illumina EPIC array. Copy numbers were analyzed using the ‘conumee’ R package and visual inspection. Next-generation sequencing (NGS) analysis was performed by NYU Langone Genome PACT, a 510(k) FDA cleared (K202304) matched tumor-normal 607 gene panel. Variant allele frequency of canonical driver mutations was used to molecularly estimate tumor cell content. Discrepant cases were assed using targeted qPCR. Our cohort of 100 CNS tumors included glioblastoma (N=75), IDH mutant astrocytoma (N=14), oligodendroglioma (N=4), pleomorphic xanthoastrocytoma (N=2), meningioma (N=1), infantile hemispheric glioma (N=1), central neurocytoma (N=1), diffuse midline glioma K27-altered (N=1), and anaplastic pilocytic astrocytoma (N=1). By DNA methylation, CDKN2A/B homozygous deletion was detected in 54 cases, hemizygous deletion was detected in 13 cases, and no deletion was detected in 33 cases. By NGS, CDKN2A/B homozygous deletion was detected in 31 cases, hemizygous deletion was detected in 28, and no deletion was detected in 41 cases. DNA methylation detected a homozygous deletion in 23 cases that were not detected by NGS. All cases of homozygous deletion detected by NGS were also detected by DNA methylation. DNA methylation derived copy number assessment is more sensitive for CDKN2A/B homozygous deletion than next generation sequencing.

Value networks, consolidation, and risks of an agricultural territory

Objective: Producer and marketer value networks in an agricultural land in Veracruz, Mexico were identified and characterized, to determine its consolidation level (primary, emergent, potential, or combined), as well as to detect risks and to establish an improvement proposal. Design/Methodology/Approach: An area of the Altas Montañas Veracruz, Mexico was used for the experiment. Surveys were conducted with producers (n=131) and marketers (n=42) of agricultural produce. Socioeconomic, environmental, technical, commercial, and chain link variables were analyzed to detect risks, opportunities, and revaluations. The study was carried out with the RStudio v. 4.3.3 software. Results: Six producer value networks and three marketer value networks were identified. Socioeconomic, environmental, commercial, and technological risks were detected. However, public health risks were different depending on the application of raw manure. Chayote and avocado have displaced other crops. The revaluation proposals for emergent and potential producer and marketer networks were focused on technical support (i.e., commercialization and generational change).

Effects of brain microRNAs in cognitive trajectory and Alzheimer’s disease

microRNAs (miRNAs) have a broad influence on gene expression; however, we have limited insights into their contribution to rate of cognitive decline over time or Alzheimer’s disease (AD). Given this, we tested associations of 528 miRNAs with cognitive trajectory, AD hallmark pathologies, and AD clinical diagnosis using small RNA sequencing from the dorsolateral prefrontal cortex of 641 community-based donors. We found 311 miRNAs differentially expressed in AD or its endophenotypes after adjusting for technical and sociodemographic variables. Among these, 137 miRNAs remained differentially expressed after additionally adjusting for several co-occurring age-related cerebral pathologies, suggesting that some miRNAs are associated with the traits through co-occurring pathologies while others through mechanisms independent from pathologies. Pathway enrichment analysis of downstream targets of these differentially expressed miRNAs found enrichment in transcription, postsynaptic signalling, cellular senescence, and lipoproteins. In sex-stratified analyses, five miRNAs showed sex-biased differential expression for one or more AD endophenotypes, highlighting the role that sex has in AD. Lastly, we used Mendelian randomization to test whether the identified differentially expressed miRNAs contribute to the cause or are the consequence of the traits. Remarkably, 15 differentially expressed miRNAs had evidence consistent with a causal role, laying the groundwork for future mechanistic studies of miRNAs in AD and its endophenotypes.

DWI lesions after intracranial aneurysm treatment with contour or WEB-does the device matter?

In this study, we report our experience with the occurrence of diffusion-weighted imaging (DWI) lesions following aneurysm treatment with Woven EndoBridge (WEB) device and Contour Neurovascular System in elective settings. We compared both techniques in a retrospective single-center analysis, to investigate whether there are significant differences in the incidence of microemboli depending on the device used. Sixty-two cases treated with Contour were retrospectively compared with 84 WEB cases. Postinterventional MRI was performed in all patients within five days after the angiographic procedure. Only DWI lesions in the dependent vascular territory of the treated aneurysm were considered. Data on occurrence of DWI lesions, device implantation times as well as device change or repositions maneuvers were compared. A total of 146 patients were included in this study. Postinterventional DWI lesions were detected in 33 of the 62 (53.2%) Contour cases and in 36 of the 84 (42.8%) WEB cases with an average lesion number of 1.70 ± 3.45 in our WEB group and 1.68 ± 2.53 in our Contour cohort. Neither periinterventional device changes nor device reposition maneuvers had a significant impact on the occurrence of DWI lesions. Although four patients experienced transient neurological deterioration, the DWI lesions were not clinically relevant at the time of discharge, as the patients' NIHSS remained stable compared to the preintervention NIHSS in the entire cohort. There was no statistically significant difference between the implantation times of WEB and Contour, although Contour could be implanted slightly faster. Aneurysm treatment with WEB or Contour results in a comparable numbers of procedure-related DWI lesions. This effect was consistent after adjustment for other demographic or technical variables.

Participation in organised sports and longitudinal development of physical activity in Swiss youth: the population-based SOPHYA cohort

BACKGROUND: Maintaining physical activity throughout life is crucial for overall health and wellbeing. Yet the age-related decline in average physical activity, a natural phenomenon also observed in animals, poses a challenge. This study aimed to investigate whether participation in organised sports supported by the Swiss Youth+Sports (Y+S) programme is associated with sustaining or enhancing physical activity among children and adolescents during 5 years of follow-up. METHODS: The longitudinal study was nested in the population-based SOPHYA (Swiss children’s Objectively measured PHYsical Activity) cohort. Participants aged 6–16 years at SOPHYA1 (2014) with complete accelerometer data from baseline and follow-up assessment (SOPHYA2, 2019) were included. The primary exposure was participation in organised sport during the follow-up period, calculated by linkage with the Y+S database as the number of days with at least one activity in Y+S-offered programmes for ages 5 to 20 years. The primary outcome was the categorisation of participants into physical activity “improvers” or “worseners”. Improvers in the respective physical activity categories – total activity counts per minute (CPM), minutes in moderate-to-vigorous activity (MVPA), minutes in light activity (LPA) and minutes in sedentary behaviour (SB) – increased or maintained their active physical activity during the 5 follow-up years. Information on confounders and effect modifiers (sex, age, body mass index (BMI), language region, household income, education) was obtained by self-report at baseline. Logistic regressions examined the relationship between organised sport participation and the probability of being a physical activity improver in each physical activity intensity category separately. Covariates for the final models were selected through a stepwise procedure based on the Bayesian information criterion from a maximal model containing all covariates as well as all two-way interactions with organised sport and between them. All models were a priori adjusted for technical variables (season of measurement; wear time; duration of follow-up). RESULTS: The analysis included 432 participants. There was a strong CPM, MVPA and LPA decline from 2014 to 2019, but an increase in SB. Nevertheless, the prevalence of improvers was 22.5% for CPM, 9.5% for MVPA, 26.9% for LPA and 9.7% for SB. Engagement in organised sport between 2014 and 2019 was positively associated with CPM, MVPA and SB, but not with LPA improver status. For 30 additional days of participation in organised sport over the five years of the study, the odds of being an improver vs being a worsener increased by 4.0% for CPM (95% CI: 0.13–7.69), 6.2% for MVPA (95% CI: 0.82–11.54) and 6.0% for SB (95% CI:−1.49–13.97). CONCLUSION: The results provide supporting evidence that organised sport in the context of the Swiss Y+S programme may empower the young to maintain an active lifestyle and even offset the age-related decline in physical activity.

Effect of Exercise Intensity on Biathlon Standing Shooting Performance and Rifle Movement during Outdoor Roller Skiing.

To investigate the effect of exercise intensity on standing shooting performance and related technical variables in elite biathletes performing roller skiing and live shooting outdoors. Nineteen male biathletes performed two 5-shot series in the following order of exercise intensity: rest, low (%heart rate max 73 ± 4; blood lactate 1.5 ± 0.3 mmol·L-1), moderate (84 ± 3; 2.4 ± 0.6), 'race-pace' (90 ± 2; 4.5 ± 0.8), and 'final-lap' (i.e., near-maximal effort: 93 ± 3; 8.7 ± 1.4). Except for rest, each shooting series was preceded by 1 km roller ski skating on a competition track. Rifle movements and triggering were determined from marker-based motion capture and accelerometer data. The primary variables were shooting outcome (hit/miss) and distance from center (dC), determined from an electronic target, and barrel velocity. Mediation analyses for shooting outcome and dC were conducted with barrel velocity (mean over last 0.25 s before triggering) as mediator and intensity as predictor. Exercise intensity increased the likelihood of miss at 'race' (odds ratio (OR) 2.2, 95% CI 1.0-4.7) and 'final-lap' (OR 2.8, 95% CI 1.4-5.8) intensities compared to rest, with no meaningful differences between rest, low, and moderate intensities. Further, intensity affected dC (~32 ± 15 mm at rest, low, and moderate, 36 ± 20 mm at 'race', and 40 ± 23 mm at 'final-lap'; p < 0.001). Barrel velocity was a partial mediator of both shooting outcome and dC, explaining some, but not all, of the effect of intensity. Exercise intensity seems to have a clear negative effect on standing shooting performance in biathlon, which is partially explained by an increase in barrel velocity. Deteriorating effects were mainly seen at the two highest (race-like) intensities. Accordingly, for specificity reasons, more shooting practice should perhaps be performed at higher, competition-like exercise intensities than what is currently the norm.

A Hybrid 2D-to-3D in vitro Differentiation Platform Improves Outcomes of Cerebral Cortical Organoid Generation in hiPSCs.

Three-dimensional (3D) cerebral cortical organoids are popular in vitro cellular model systems widely used to study human brain development and disease, compared to traditional stem cell-derived methods that use two-dimensional (2D) monolayer cultures. Despite the advancements made in protocol development for cerebral cortical organoid derivation over the past decade, limitations due to biological, mechanistic, and technical variables remain in generating these complex 3D cellular systems. Building from our previously established differentiation system, we have made modifications to our existing 3D cerebral cortical organoid protocol that resolve several of these technical and biological challenges when working with diverse groups of human induced pluripotent stem cell (hiPSC) lines. This improved protocol blends a 2D monolayer culture format for the specification of neural stem cells and expansion of neuroepithelial progenitor cells with a 3D system for improved self-aggregation and subsequent organoid development. Furthermore, this "hybrid" approach is amenable to both an accelerated cerebral cortical organoid protocol as well as an alternative long-term differentiation protocol. In addition to establishing a hybrid technical format, this protocol also offers phenotypic and morphological characterization of stage-specific cellular profiles using antibodies and fluorescent-based dyes for live cell imaging. © 2024 Wiley Periodicals LLC. Basic Protocol 1: hiPSC-based 2D monolayer specification into neural stem cells (NSCs) Basic Protocol 2: Serial passaging and 2D monolayer expansion of neuroepithelial progenitor cells (NPCs) Support Protocol 1: Direct cryopreservation and rapid thawing of NSCs and NPCs Basic Protocol 3: Bulk aggregation of 3D neurospheres and accelerated cerebral cortical organoid differentiation Alternate Protocol 1: Bulk aggregation of 3D neurospheres and long-term cerebral cortical organoid differentiation Support Protocol 2: High-throughput 3D neurosphere formation and 2D neurosphere migration assay Support Protocol 3: LIVE/DEAD stain cell imaging assay of 3D neurospheres Support Protocol 4: NeuroFluor NeuO live cell dye for 3D cerebral cortical organoids.

Analysis of the impact of different intensities and time periods on the physical and technical performance of professional soccer players

Soccer match simulations provide valuable information on player performance and training methods but how intensity during a game affects a player's physical/technical performance has yet to be explored. The objective of the study was to analyse the impact of variable intensity intervals during the first block of the Copenhagen Soccer Test. A repeated measures study was designed to compare three intensity levels, three time periods and their effects on sprint speed, perceived effort, goal shooting accuracy, dribbling, and long pass accuracy in professional soccer players. The comparison analysis between different phases showed a significant decrease in sprint speed (p &lt; 0.001) and an increase in perceived effort (p &lt; 0.001), however, the technical variables did not change (p &gt; 0.05). When comparing the data based on intensity, significant decreases were observed in all variables (p &lt; 0.001). The combined analysis of the results indicates that the speed decreases and the rate of perceived exertion increases as the simulation progresses. Meanwhile, the accuracy of goal kicks, dribbling, and long passes are negatively affected by high-intensity efforts, but demonstrate recovery over the course of the simulation. The increase in intensity affects the speed more than the accuracy of shots on goal, dribbling and passing. Keywords: Performance, Soccer, Intensity, Physical performance, Technical performance.

Abstract A031: Methylomic Biomarkers Associated with Prostate Cancer in Black Men

Abstract Introduction: The prostate cancer (PCa) disparity remains the highest cancer disparity in the US, with Black men facing an estimated 78% higher incidence and 230% higher mortality than White men. However, current understanding of risk factors for PCa such as socioeconomic status (SES), diet, and genetics cannot fully explain these disparities. Our objective is to examine DNA methylation (DNAm) markers in a cohort of Black men and assess their associations with PCa status. Methods: We randomly selected 100 Black men for DNAm profiling (50 cases diagnosed with clinically significant (Gleason Grade 3+) prostate cancer and 50 age-matched controls) from two larger cohorts. The cohorts recruited 400 Black men who were newly diagnosed with sporadic PCa as well as 400 controls matched on age and race. All men were 40-79 at recruitment and were enrolled from urology clinics at five Chicago-area medical institutions. All PCa cases underwent a transrectal prostate biopsy for abnormal prostate-specific antigen (PSA) or digital rectal exam and had a histologically confirmed prostate cancer and were not previously diagnosed with PCa. All men in the control group had been recruited from community prostate cancer screening events or were referred to participating urology clinics and had a negative prostate biopsy for a PSA &amp;lt;10ng/ml and were not diagnosed with PCa for 2 years of follow-up. Men with prior PCa diagnosis or conditions known to affect PSA levels were excluded. After enrollment and informed consent, all men provided demographic and lifestyle data via three questionnaires, followed by venipuncture for DNA collection. These specimens were obtained using buffy coat extraction after red blood cell lysis, centrifugation, and pipetting off the overlying plasma and buffy coat for freezing followed by Illumina EPIC arrays for DNAm assays. We examined DNAm markers in gene promoter regions associated with PCa using logistic regression and adjusted for multiple testing using Bonferroni correction. All models controlled for age, BMI, smoking status, first degree family history of PCa, blood cell types, and technical control variables. Results: We found 2,180 CpG sites in gene promoter regions associated with any PCa in this population. The top ten strongest associations identified in our models include loci on genes that have already been associated with prostate cancer progression (MAFG, FAM65B, OSM, PRKAG2), risk (SLC11A1, LAT), and metastasis (S1PR4) as well as immune system functioning (RAP1GAP2). Conclusions: Our initial findings suggest that DNAm markers may be useful predictors of clinically significant PCa status among Black men. Additional research is currently ongoing to expand the sample size of the DNAm profiling and to explore links between these loci and social determinants of health, as well as associations with more advanced (i.e., higher Gleason Grade) PCa. Citation Format: Brian T. Joyce, Yishu Qu, Jun Wang, Kai Zhang, Zequn Sun, Lifang Hou, Adam B. Murphy. Methylomic Biomarkers Associated with Prostate Cancer in Black Men [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr A031.

Physical and technical attributes associated with on-water rowing performance in junior and elite rowers

ABSTRACT On-water rowing performance consists of the integration of physical and technical attributes. This exploratory study aimed to describe key physical and technical variables for elite and junior rowers and examine the associations and predictive capacity of these variables with on-water rowing performance outcomes. Twenty-eight junior (16 females, 16 ± 0.8 years and 12 males, 17 ± 0.7 years) and 24 elite rowers (12 females, 24 ± 2.7 years and 12 males, 27 ± 2.6 years) completed an on-water, single sculling biomechanics assessment combined with a series of physical, strength and power tests. Elite men and women were superior in mean gate force, distance per stroke and recovery distance compared to junior groups as determined by independent t-tests and effect size appraisal (p < 0.017, d > 1.2). Large associations (p < 0.01) were evident between anthropometry, strength and power assessments with the on-water measures of catch angle, mean gate force, recovery distance and boat speed. Differences in ROM and flexibility attributes did not distinguish between elite and junior rowers. Linear discriminant analysis revealed that individual rowers can be appropriately categorised by sex and performance level based on their physical and technical attributes. This battery of testing with world-class athletes represents an excellent level of ecological validity for the assessment of rowers pertinent to on-water performance.

Methodological Planning to Determine the Technological Expansion of Smart Metering Systems for Utilities

This research uses data analysis and mining techniques to determine the technological expansion of measurement systems in a public service company. It integrates technical, economic, geographic, and social variables into the analysis using machine learning techniques to discover patterns and relationships in large data sets. The fuzzy logic methodology is applied using the MATLAB programming tool “Fuzzy Logic” to build algorithms that allow for the correct selection of measurement, achieving greater efficiency and precision in the assignment of meter types. The results show that 98% of the metering systems in the significant part are electronic meters, with the “Residential BT” rate being the most extensive data set. Implementing the “fuzzy logic” technique recognizes that more than 60% of the meters are electronic, with the registration of active energy, reactive energy, and demand, allowing for greater control over the marketing variables of the distribution system operator. This research suggests that a future restructuring of electrical metering systems benefits the company and its users. By applying the analysis, a portfolio of viable projects for the replacement of measurement systems is obtained, and they are grouped into two clusters based on the total cost of the technological change.

Effects of the number of ball touches among elite youth players during small-sided soccer games.

This study investigates the effects of manipulating the number of ball touches (free play vs. two touches) on the physical and technical actions of elite male youth soccer players during 5v5 + 2 goalkeepers (GKs) small-sided games (SSGs). Players played in two different SSGs: 1) free play, where the number of touches per possession was not restricted; and 2) two touches, where players were limited to a maximum of two touches per ball possession. A total of 24 male elite youth soccer players (age: 14.79±0.71 years; body mass: 56.02±1.41 kg; body height: 164±2.12 cm) participated in the study. Players' physical metric and technical performance data were captured using a global positioning system and video camera, respectively. A paired-samples t-test or Wilcoxon Signed-Rank Test was employed to examine differences in players' technical performance variables depending on SSGs' ball-touch rules. The results show significantly more unsuccessful passes (t=-3.48; P=0.04; d=1.92) when players were limited to two touches than when there were no pass limits. The physical metrics indicate that total distance covered (Z=-2.90; P=0.001; d=0.07), meters per minute (Z=-3.44; P=0.001; d=0.11), low-speed running (Z=-2.25; P=0.02; d=0.04) and high acceleration (Z=-1.90; P=0.05; d=0.28) were significantly higher when touches were unlimited than when they were not. Soccer coaches should decide the number of touches per ball possession they allow depending on their tactical and/or physical objectives in training.

The Influence of Strategic Procurement on the Performance of the European Naval Defense Industry

ABSTRACT The naval defense industry plays a crucial role in national security, particularly in the context of global rearmament and shared threats. However, the industry’s performance in Europe has been hindered by factors such as decreased fleets, shrinking industry capabilities, and increasing production costs. This study of 102 large surface vessels (frigates and destroyers) from eight European countries found that production time is positively correlated with technical variables such as weight and speed. A small but significant learning effect also existed, with a 1.5-month decrease for each marginal increase of one unit in the batch. Regarding strategic sourcing, the study found no effect of the share of US subsystems on production time. However, European cooperation led to an increase in production time, likely due to higher coordination costs. Conversely, importing subsystems from a European ally tended to reduce production time. The study’s findings highlight the challenges facing the naval defense industry in Europe and suggest that strategies such as increasing batch size and cooperation with European allies can help to improve performance.

Towards benchmarking VR sickness: A novel methodological framework for assessing contributing factors and mitigation strategies through rapid VR sickness induction and recovery

Virtual Reality (VR) sickness remains a significant challenge in the widespread adoption of VR technologies. The absence of a standardized benchmark system hinders progress in understanding and effectively countering VR sickness. This paper proposes an initial step towards a benchmark system, utilizing a novel methodological framework to serve as a common platform for evaluating contributing VR sickness factors and mitigation strategies. Our benchmark, grounded in established theories and leveraging existing research, features both small and large environments. In two research studies, we validated our system by demonstrating its capability to (1) quickly, reliably, and controllably induce VR sickness in both environments, followed by a rapid decline post-stimulus, facilitating cost and time-effective within-subject studies and increased statistical power, (2) integrate and evaluate established VR sickness mitigation methods — static and dynamic field of view reduction, blur, and virtual nose — demonstrating their effectiveness in reducing symptoms in the benchmark and their direct comparison within a standardized setting. Our proposed benchmark also enables broader, more comparative research into different technical, setup, and participant variables influencing VR sickness and overall user experience, ultimately paving the way for building a comprehensive database to identify the most effective strategies for specific VR applications.

Alcohol Use Disorder–Associated DNA Methylation in the Nucleus Accumbens and Dorsolateral Prefrontal Cortex

BackgroundAlcohol use disorder (AUD) has a profound public health impact. However, understanding of the molecular mechanisms that underlie the development and progression of AUD remains limited. Here, we investigated AUD-associated DNA methylation changes within and across 2 addiction-relevant brain regions, the nucleus accumbens and dorsolateral prefrontal cortex. MethodsIllumina HumanMethylation EPIC array data from 119 decedents (61 cases, 58 controls) were analyzed using robust linear regression with adjustment for technical and biological variables. Associations were characterized using integrative analyses of public annotation data and published genetic and epigenetic studies. We also tested for brain region–shared and brain region–specific associations using mixed-effects modeling and assessed implications of these results using public gene expression data from human brain. ResultsAt a false discovery rate of ≤.05, we identified 105 unique AUD-associated CpGs (annotated to 120 genes) within and across brain regions. AUD-associated CpGs were enriched in histone marks that tag active promoters, and our strongest signals were specific to a single brain region. Some concordance was found between our results and those of earlier published alcohol use or dependence methylation studies. Of the 120 genes, 23 overlapped with previous genetic associations for substance use behaviors, some of which also overlapped with previous addiction-related methylation studies. ConclusionsOur findings identify AUD-associated methylation signals and provide evidence of overlap with previous genetic and methylation studies. These signals may constitute predisposing genetic differences or robust methylation changes associated with AUD, although more work is needed to further disentangle the mechanisms that underlie these associations and their implications for AUD.

Comparative study of the initiation flute methods in Galicia

The initiation to the study of the transverse flute involves the acquisition of a basic technique which is learned through different methods of initiation, but: do they adjust to the technical variables of the legislative framework? What are the most significant technical parameters for the teachers of the Xunta de Galicia? The main objective of this research is to know which methodological proposal works the contents established in the regulatory framework more effectively. To do this, a methodology consisting of an analysis of the methods and the design and validation of a questionnaire for the teachers in Galician conservatories has been used. The conclusions are revealing in the sense that the teaching of flute in this Autonomous Community is carried out through three methods, and none of them fully satisfy neither the concerns of teachers nor the demands of Galician legislation.

Technical and fundamental analysis of insurance stock prices on the Indonesian Stock Exchange (2018–2022)

Purpose: This study was conducted to determine the influence of fundamental (ROA, TATO, DER, NPM, and EPS) and technical (past share price, share volume, and past share volume) variables on share prices. in insurance companies listed on the IDX. Method: This study uses secondary data in the form of panel data, namely a combination of time series data for quarterly periods for five years, namely 2018-2022 and cross-sectional data from 11 insurance companies on the Indonesia Stock Exchange. The relationship between the research variables was tested using a panel data regression analysis. Results: The t-test results from the fixed effects model show that TATO and DER have a positive and significant influence on stock prices. ROA, NPM, and EPS do not significantly influence share prices. Past share prices and share volume have a significant positive influence on stock prices, whereas past share volume has a significant negative influence on share prices. The F-test results from the fixed effects model show that there is a significant influence of the independent variables, namely fundamental and technical variables, on stock prices. Limitations: This study only analyzes insurance companies (other than reinsurance) listed on the IDX from to 2018-2022, issue quarterly financial reports continuously from to 2018-2022, and have never been delisted during that period. Contribution: The contribution of this research is that it considers investors in making investment decisions, especially in selecting insurance company shares.

Unveiling the nonlinear dynamics of player performance in China’s super league as a function of age

To explore the dynamics in physical and technical performance of professional football players and changes across age groups. Match statistics were collected from 1900 games across ten seasons (2012–2021) in the Chinese Super League. Generalized additive models visualized age-related trends in 12 key performance indicators including technical and physical variables. Revealed nonlinear trajectories characterized by rapid early declines, stable peak periods and accelerated late decreases. Physical indicators decreased progressively from the early 20 s before stabilizing briefly then declining further after 30. Conversely, technical metrics gradually improved into the late 20 s and early 30 s prior to decreasing again. This study provides novel evidence that football performance changes nonlinearly across age. Targeted training and development strategies should be tailored to the specific needs of different career stages.

Technical and Physical Load Variables at Different Positions in U18 Semi-Professional Soccer Players: Differences between the First and Second Half

Among the many factors that can affect men’s soccer performance, technical and tactical actions can obscure relevant game data, even affecting specialists in both the programming and design of training tasks. We aimed to evaluate the technical and physical load variables of different positions in U18 semi-professional soccer players and observe the differences between the first and second halves during 10 matches of the 2021/2022 Spanish Football U18 National League Championship. A total of 246 match records (10 matches) were collected from the 2021/2022 Spanish Football U18 National League Championship. Two teams participated, with a total of 49 athletes. Our study’s results indicate that, concerning technical performance, no significant differences between halves were found for goalkeepers, wingers, and forwards. However, significant declines were observed in the number of ball contacts, different actions per time, and possessions per time among central defenders, lateral defenders, and central midfielders. Regarding the observed physical load demands, it was noted that in outfield players, there was a significant decline in total distances covered at different speed thresholds, as well as a decrease in the number and distance of acceleration measures, most of which were lower in the second halves compared to the first, irrespective of playing positions. This study contributes to enhancing our understanding of the multifaceted dynamics of soccer performance and provides valuable insights for coaches, players, and researchers aiming to optimize player performance.

Steadiness of technical variables as a determinant factor of performance in a virtual simulated regatta

ABSTRACT The aim of this investigation is to explore the relationship between Optimist sailing performance with boat steadiness as well as the steadiness of cyclic variables related to sailors’ technique, in the upwind leg of a regatta. Thirty-two sailors from the optimist class (16 bottom level and 16 top level) performed a regatta in a semi-immersive simulator which measures the instantaneous velocity, heading, boom, heel, and rudder angle and hiking effort. It was calculated the mean values as well as the short-term steadiness and long-term steadiness throughout the test. Top level and bottom level sailors were compared and the correlation between these variables and mean velocity were analysed. Significant differences were found between groups on mean values, STS values and LTS values as well as significant correlations ranging r values between 0.385 and 0.768. If the steadiness of sailing variables is considered, they appear as determinants of performance in Optimist class while this is not observed when analysing mean values.