Variance For Measures Research Articles

Informing factors and outcomes of self-assessment practices in medical education: a systematic review

Background Self-assessment (SA) is increasingly recognized not only as an assessment method but also as a vital learning activity that enables learners to identify their strengths and limitations, fostering a crucial skill for lifelong learning. Despite its acknowledged significance, there remains a gap in understanding SA for and as learning, rather than merely of learning. This review, therefore, explores two primary questions: (1) What factors inform the implementation of medical students’ SA practices? (2) How does SA practices contribute to various educational outcomes? Methods A systematic review was conducted across five databases, employing a combination of keywords pertinent to SA and medical education. Our selection criteria deliberately excluded articles that solely focused on the accuracy of SA or used SA exclusively as a measure for other outcome variables. As a result, 39 studies met our inclusion criteria and were analyzed for this review. Qualitative narrative synthesis was used to summarize the informing factors. Furthermore, Kirkpatrick’s model was employed to categorize and summarize the effects of SA activities across various educational outcome levels, including reactions, learning, and behavioral changes. Results Our review reveals that key factors influencing students’ SA includes feedback from various stakeholders, peer assessment, the format of SA, and both learner and teacher training. Among the 39 studies examined, the majority demonstrated positive effects of SA on aspects such as attitudes and skills. However, a minority found no significant associations, with these outcomes frequently linked to contextual variables and how SA was implemented. Conclusions Our review does not focus on SA accuracy or its role as an assessment method; instead it delves into the role of SA as an integral learning practice. We explored its influencing factors and its impact across various outcomes. The findings indicate that for SA to effectively enhance student learning outcomes, it must be implemented with ample support, clear guidelines, and within contexts that encourage feedback and reflection.

An Inconvenient Truth: A Comprehensive Examination of the Added Value (or Lack Thereof) of Leadership Measures

AbstractThe leadership literature encompasses a bewildering array of leadership styles, with most studies focussing on the nature and consequences of a single leadership style in isolation. This isolationist approach has led researchers to mostly ignore the similarities between supposedly different leadership styles, and few studies have examined these overlaps empirically. To understand the extent of this problem, we use bifactor exploratory structural equation modelling to examine whether 12 dominant leadership measures capture shared variance and whether any variance unique to a particular style is related to theoretically and empirically established covariates. Moreover, we explore what the shared variance of these leadership measures may represent. Across seven samples, five countries, multiple organizational contexts, and 4000 respondents, the 12 leadership measures shared significant amounts of variance and did not systematically capture unique leadership‐related variance. Further analyses indicated this shared variance mainly represented the affective quality of the leader–follower relationship. The results reveal an inconvenient truth for leadership researchers who wish to differentiate styles, as the styles have much more in common than differences. Contrasting with previous recommendations to refine styles, we argue that a taxonomic leadership behaviour categories approach to leadership research is the most parsimonious way forward.

Enhancing Hyperspectral Anomaly Detection Algorithm Comparisons: Leveraging Dataset and Algorithm Characteristics

Validating the contributions of new algorithms is a critical step in hyperspectral anomaly detection (HAD) research. Typically, validation involves comparing the performance of a proposed algorithm against other algorithms using a series of benchmark datasets. Despite the longstanding use of this comparison process, little attention has been paid to the characteristics of datasets and algorithms that ensure each algorithm has an equal opportunity of performing well. Characteristics of datasets and algorithms that inadvertently favor one algorithm can skew results, leading to misleading conclusions. To address this issue, this study introduces a feature-centric framework designed to assist in ensuring an unbiased comparison of HAD algorithms. The framework identifies significant correlations between datasets and algorithms by extracting distribution-related features from the datasets and statistically testing them against the algorithmic outcomes. The identified trends are then compared across datasets to ensure that all relevant trends are equally represented, thereby ensuring diversity and validating that no singular algorithm is afforded an inherent advantage. The framework was tested on five algorithms across 14 datasets. The results indicate that multiple measures of variance within the datasets are key drivers of diversity, and these measures accurately predicted algorithmic outcomes for 12 of the 14 datasets. This suggests that the identified trends effectively explain the algorithmic outcomes and highlights the importance of incorporating datasets with a diverse range of variances in comparisons of HAD algorithms.

Efficacy of racemic ketamine or esketamine monotherapy for reducing suicidal ideation in uni- or bipolar depression: a systematic review and meta-analysis.

The current systematic review and meta-analysis examined the effect of racemic ketamine or esketamine on suicidal ideation in individuals with uni- or bipolar depression. We searched the MEDLINE, Embase, Central, PsycINFO, and Web of Science databases to identify randomized controlled trials that examined the effect of racemic ketamine or esketamine monotherapy on suicidal ideation (SI) in individuals with uni- or bipolar depression. The two monotherapies were compared; the primary outcome was the rate of remission of SI, and the secondary outcome was the SI score. The risk ratio was used as an effect size measure for binary variables, while the standardized mean difference was used as an effect size measure for continuous variables. Our meta-analysis included 13 randomized controlled trials involving 1,1109 individuals with uni- or bipolar depression. Patients receiving racemic ketamine monotherapy had a significantly higher acute SI remission rate than those receiving placebo or midazolam (RR = 2.06, 95% CI 1.47 to 2.91, P < 0.0001). Racemic ketamine also led to significantly lower SI scores than placebo or midazolam (SMD = -0.36, 95% CI -0.71 to -0.01, P = 0.04). The evidence for the treatment of SI with esketamine was inconsistent. The pooled effect sizes for long-term anti-SI effects did not reveal significant differences between therapies. Our study indicated the efficacy of racemic ketamine monotherapy for rapidly and transiently reducing SI in individuals with uni- or bipolar depression, but the efficacy of racemic ketamine monotherapy against long-term suicidal ideation remains unclear. There is not -sufficient evidence to support the anti-suicidal effects of esketamine monotherapy.Protocol registration: Prospero registration number: CRD42023434380.

Analysing the effects of feeding black soldier fly on broiler growth performance: a meta-analysis

Context The black soldier fly has been found to be a rich protein source, containing high amounts of protein and lipids, making them a valuable and sustainable alternative to conventional protein sources, such as fish and soybean meals, for broilers, which has also been demonstrated by multiple studies. Aims A meta-analysis was conducted using peer-reviewed published research on the use of black soldier flies in poultry diets to test the hypothesis that it enhances growth performance as a sustainable alternative to plant-based protein sources. Methods To this end, we used publicly available databases (Google Scholar, PubMed, Science Direct, Embase) to identify peer-reviewed papers. Retrieved articles were screened for relevance and quality using established criteria. The studies were largely rejected due to non-reporting of variance measures or reporting pooled measures of variance that could not be used. As a result, eight studies were used to extract data for growth performance, including body weight gain. Key results The meta-analysis showed that the effect of feeding black soldier fly meals on body weight gain was non-significant. However, the subgroup analysis showed that utilisation of the frozen form of the black soldier fly lowers body weight gain compared with the birds fed basal diets. Furthermore, the feed intake was significantly (P &lt; 0.05) reduced when the broilers were fed with diets containing black soldier fly meals. The feed conversion ratio showed non-significant (P &gt; 0.05) differences with the supplementation. Conclusions The inclusion level of black soldier fly larvae meal in any form was seen to be safe up to 10%, and the effective duration of the supplementation was ≤35 days. Implications The utilisation of black soldier fly as a sustainable protein source should be encouraged to facilitate farmers in terms of being less dependent on soybean meal, as well as to reduce the competition between humans and animals for plant protein sources.

Metrics of Astrometric Variability in the International Celestial Reference Frame. I. Statistical Analysis and Selection of the Most Variable Sources

Using very long baseline interferometry data for the sources that comprise the third International Celestial Reference Frame (ICRF3), we examine the quality of the formal source-position uncertainties of ICRF3 by determining the excess astrometric variability (unexplained variance) for each source as a function of time. We also quantify multiple qualitatively distinct aspects of astrometric variability seen in the data, using a variety of metrics. Average position offsets, statistical dispersion measures, and coherent trends over time as explored by smoothing the data are combined to characterize the most and least positionally stable ICRF3 sources. We find a notable dependence of the excess variance and statistical variability measures on decl., as is expected for unmodeled ionospheric delay errors and the Northern Hemisphere–dominated network geometries of most astrometric and geodetic observing campaigns.

Choosing of Telecommunications Equipment Suppliers Based on the Choquet Integral and Fuzzy Measure Variance Minimization

Telecommunications equipment suppliers play an important role in the functioning of corporations with large-scale distributed computer networks such as system integrators, Internet service providers and others. An important condition of sustainable development for these companies is effective and reasonable decision making concerning the choice of suppliers. At the same time, the amount of information to be considered in many industries for making decisions has grown several times. In accordance with the above, decision making support systems for the reliable choice of suppliers started to be developed. At the same time, the approaches to designing such systems possess some disadvantages. In order to overcome these disadvantages this article suggests an approach to decision making support for choosing telecommunication equipment suppliers based on the Choquet Integral and minimization of fuzzy measure variance. It deals with the task of criteria normalization, fuzzy measure identification, gives examples of expert estimations for criteria and also the results of supplier assessments based on which the decision is made.

Study of body measurements and components of variance for various body measurements of goats found in Southern Punjab

Variance components are estimated to further compute genetic parameters, and these components reflect variation of traits as well as their transferability to the next generation. This study was conducted to estimate variance components for different body measurements in Teddy goats in the southern Punjab. Data were subjected to mixed model analysis using ASReml software where restricted maximum likely hood procedure was adopted. These body measurements included diagonal body length, withers height, head length, neck length, ear length, ear width, tail length, distance between ears, and canon circumference. Body measurements were recorded using tailor tape and live weight will be measured by spring balance. The following form of animal model was applied; Yijklm= YOBi+ SOBj + Sexk + TOBl + A +Ԑijklm.. The estimates for variance components were used to compute genetic parameters.

Variance partitioning of nest provisioning rates in blue tits: individual repeatability, heritability, and partner interactions.

In many animal species, including most birds, parental care is performed by both parents, which has important implications for mate choice (good parent hypothesis) and parental investment strategies. Partitioning the variance in measures of parental care into heritable and nonheritable components is important to understand the evolvability of parental investment and its potential role in mate choice. We employed an automated system to monitor provisioning behavior at 817 blue tit nests over 10 years (totaling ~3 million visits). Daily provisioning rates of males and females were moderately repeatable between years (Radj = 0.16 and 0.15, respectively), which was almost entirely explained by additive genetic effects. While this degree of heritability is sufficient for parental investment to respond to selection, we argue that the modest level of repeatability provides limited potential for a "provisioning phenotype" to be used as a criterion in mate choice. Daily visit rates were positively correlated between pair members, but after accounting for shared environmental factors, this relationship became clearly negative, thereby providing support for models of partial compensation. Visit rates also differed substantially between years, and between days within a year. Thus, it is important to account for these variables when comparing the parental investment between individuals. Our results highlight the interplay between genetic, social, and environmental influences on provisioning behavior.

311 Effect of feeding butyric acid on growth performance and metabolic indicators of dairy calves before weaning: A meta-analysis

Abstract This meta-analysis aimed to evaluate the effect of feeding butyric acid (BA) on growth performance and metabolic indicators in dairy calves. A literature search was conducted to identify in vivo research studies carried out on BA supplementation in dairy calves. Inclusion criteria were in vivo studies, dairy calves, weaning, BA, and inclusion doses of BA. Twenty-three papers with 80 data and 1,132 calves were selected. Data extracted included the number of calves in control and treatment groups and measures of variance of responses (standard error or standard deviation). The response variables were production performance including body weight (BW), average daily gain (ADG) feed efficiency (FE), and metabolic indicators including blood glucose and beta-hydroxybutyrate (BHB) concentrations. A random effect of model was used to examine the raw mean difference and standardized mean difference between BA supplementation and the control group. The analysis was conducted using the metafor package of Rstudio. Butyric acid moderately improved the growth performance and metabolic indicators responses of calves with substantial heterogeneity (59 &amp;lt; I2 &amp;lt; 73%, P &amp;lt; 0.01). Final BW and ADG were increased by 2.7 kg and 48.1 g/day, or &amp;gt; 0.6 and &amp;gt; 0.4 standard deviation units (P &amp;lt; 0.05), respectively. However, FE was increased by BA supplementation but not significantly different. For metabolic indicators, glucose concentration was greater with BA supplementation with &amp;gt; 0.4 standard deviation unit, (P &amp;lt; 0.05). However, BA supplementation did not affect the blood concentration of BHB (P &amp;gt; 0.05). In conclusion, the meta-analysis results demonstrated that BA constitutes an important energy source for dairy calves. Butyric acid is effective in promoting growth performance and intestinal health and, yet, increasing production profits.

Clinical effect of XEN gel stent implantation or combined with phacoemusification and intraocular lens implantation on glaucoma

Objective: To evaluate the efficacy and safety of internal XEN gel stent implantation or combined with phacoemusification and intraocular lens (IOL) implantation in the treatment of glaucoma. Methods: It was a retrospective case series study. Forty-five patients (28 males and 17 females; 52 eyes) who had different types of glaucoma treated at the Shenzhen Eye Hospital from December 2021 to June 2023 were included. XEN gel stent implantation (the XEN group) or XEN implantation combined with phacoemusification and IOL implantation (the combined group) were performed in these patients. The postoperative follow-up was 18 months. The observational indexes included the best corrected visual acuity (recorded as the logarithm of the minimum angle of resolution), intraocular pressure (IOP), XEN implantation quadrant, number of IOP-lowering medications, corneal endothelial cell count, operation success rate and surgical complications. The one-way repeated measures of variance, LSD-t test, and rank sum test were used for statistical analysis. Results: There were 28 patients (33 eyes) in the XEN group and 17 patients (19 eyes) in the combined group. The postoperative best corrected visual acuity had no significant change in the XEN group, but improved significantly (0.21±0.30 at 6 months; P<0.05) in the combined group, compared with the preoperative value. The IOP of the two groups at 18 months after surgery [(12.2±3.1) and (11.9±3.9) mmHg (1 mmHg=0.133 kPa)] was significantly lower than that before surgery [(22.1±8.5) and (19.4±10.2) mmHg; P<0.05]. The average number of IOP-lowering medications in all patients was 3 (2, 3) before surgery and 0 (0, 0) at 18 months after surgery. The difference was statistically significant (P<0.05). In the XEN group, the corneal endothelial cell count was (2 387.37±478.22) cells/mm² preoperatively and (2 193.89±311.96) cells/mm² at 12 months. The decrease showed no statistical significance. The XEN gel stent was implanted in the supranasal quadrant in 8 eyes (15.4%), in the inferonasal quadrant in 36 eyes (69.2%), and in the infratemporal quadrant in 8 eyes (15.4%). The operation success rate [complete success rate, 86.5% (45/52); conditional success rate, 9.6% (5/52)] was 96.2% (50/52). The filtering bleb scarring occurred in 9.6% (5/52) of eyes. A small amount of hyphema, postoperative shallow anterior chamber, transient hypertension, and intraoperative drain breakage were found in 7.7% (4/52) of eyes, respectively. A small amount of subconjunctival bleeding was observed in 5.8%(3/52) of eyes. Re-implantation of an XEN gel stent was performed in 5.8% (3/52) of eyes. The intraoperative conjunctival tissue rupture, hypotony macular edema, and drain exposure were observed in 1.9% (1/52) of eyes, respectively. Conclusion: The XEN gel stent implantation or combined with phacoemusification and IOL implantation was effective and safe in treating different types of glaucoma, but its long-term clinical efficacy needs further follow-up observations in multi-center, larger-scale research.

Age-related differences in human cortical microstructure depend on the distance to the nearest vein

Abstract Age-related differences in cortical microstructure are used to understand the neuronal mechanisms that underlie human brain ageing. The cerebral vasculature contributes to cortical ageing, but its precise interaction with cortical microstructure is poorly understood. In a cross-sectional study, we combine venous imaging with vessel distance mapping to investigate the interaction between venous distances and age-related differences in the microstructural architecture of the primary somatosensory cortex, the primary motor cortex and additional areas in the frontal cortex as non-sensorimotor control regions. We scanned 18 younger adults and 17 older adults using 7 Tesla MRI to measure age-related changes in longitudinal relaxation time (T1) and quantitative susceptibility mapping (QSM) values at 0.5 mm isotropic resolution. We modelled different cortical depths using an equi-volume approach and assessed the distance of each voxel to its nearest vein using vessel distance mapping. Our data reveal a dependence of cortical quantitative T1 values and positive QSM values on venous distance. In addition, there is an interaction between venous distance and age on quantitative T1 values, driven by lower quantitative T1 values in older compared to younger adults in voxels that are closer to a vein. Together, our data show that the local venous architecture explains a significant amount of variance in standard measures of cortical microstructure and should be considered in neurobiological models of human brain organisation and cortical ageing.

Measurement Invariance Testing Works.

Psychometricians have argued that measurement invariance (MI) testing is needed to know if the same psychological constructs are measured in different groups. Data from five experiments allowed that position to be tested. In the first, participants answered questionnaires on belief in free will and either the meaning of life or the meaning of a nonsense concept called "gavagai." Since the meaning of life and the meaning of gavagai conceptually differ, MI should have been violated when groups were treated like their measurements were identical. MI was severely violated, indicating the questionnaires were interpreted differently. In the second and third experiments, participants were randomized to watch treatment videos explaining figural matrices rules or task-irrelevant control videos. Participants then took intelligence and figural matrices tests. The intervention worked and the experimental group had an additional influence on figural matrix performance in the form of knowing matrix rules, so their performance on the matrices tests violated MI and was anomalously high for their intelligence levels. In both experiments, MI was severely violated. In the fourth and fifth experiments, individuals were exposed to growth mindset interventions that a twin study revealed changed the amount of genetic variance in the target mindset measure without affecting other variables. When comparing treatment and control groups, MI was attainable before but not after treatment. Moreover, the control group showed longitudinal invariance, but the same was untrue for the treatment group. MI testing is likely able to show if the same things are measured in different groups.

Health and Well-Being Among College Students in the United States During the COVID-19 Pandemic: Daily Diary Study.

There is evidence that anxiety and stress increased among college students during the COVID-19 pandemic. However, less is known about daily experiences of affect, worry, substance use behaviors, experiences of pleasure, concern over food security, experiences of bias or discrimination, feelings of belongingness, and other indicators of well-being and how they vary across days in this population. This study surveyed a wide range of indicators of health and well-being in daily life over 21 days with a sample of college students in a large university system in the United States during the pandemic. The overall variance in each daily measure was partitioned to reflect the proportion due to (1) between-person differences versus (2) within-person, day-to-day variability. This is important because measures that vary primarily due to between-person differences may be more amenable to interventions that target particular students, whereas measures that vary more due to day-to-day variability may be more amenable to interventions that target day-level contextual factors. A sample of 2068 young adult college students (aged 18-24, mean 19.8, SD 1.3 years; 66.6% women) completed a baseline survey; 97.3% (n=2012) then completed up to 21 consecutive daily surveys that assessed a comprehensive set of daily markers of health, behavior, and well-being. The daily diary study produced a total of 33,722 person-days. Among all person-days, a minority were substance use days (eg, 14.5% of days involved alcohol use, 5.6% vaping, and 5.5% cannabis). Experiences of pleasure were reported on most (73.5%) days. Between-person differences explained more than 50% of the variance in numerous indicators of health and well-being, including daily vaping, cannabis use, other illicit substance use, experiences of bias or discrimination, positive affect, negative affect, worry, food insecurity, and feelings of belonging at the university. In contrast, within-person differences explained more than 50% of the variance in daily alcohol use, cigarette use, stress, experiences of pleasure, where the student slept last night, and physical activity. College student health and well-being are multifaceted, with some aspects likely driven by person-level characteristics and experiences and other aspects by more dynamic, contextual risk factors that occur in daily life. These findings implicate services and interventions that should target individual students versus those that should target days on which students are at high risk for poor experiences or behaviors.

Foreign language enjoyment overcomes anxiety and boredom to boost oral proficiency in the first year of English foreign language learning

AbstractThe current study investigates the effect of three foreign language learner emotions on the amount of gain in oral proficiency over one school year of 159 eleven‐year‐old pupils starting English foreign language classes in France. Previous cross‐sectional studies have shown positive relationships between foreign language enjoyment (FLE) and various performance and achievement measures, as well as negative relationships between foreign language classroom anxiety (FLCA), foreign language classroom boredom (FLCB), and FL performance and achievement measures. A common finding is that negative emotions explain more variance in Foreign Language (FL) performance and achievement measures at a single point in time than positive emotions. Correlation analyses revealed that the amount of gain was positively linked to FLE and negatively linked FLCA and FLCB. A first multiple regression analysis showed that, surprisingly, FLE was the only (positive) predictor of gain in oral proficiency. A second multiple regression analysis revealed that the FLE teacher dimension was the only predictor of gain in oral proficiency. This suggests that positive emotions, and especially the ability of teachers to meet the psychological needs of their students, have a stronger long‐term effect while negative emotions are more likely to disrupt performance in the moment. Pedagogical implications are presented.

How anatomy influences measurements of snakes.

Anatomy compromises the precision and accuracy of measurements made of the body length and head size of live snakes. Body measures (snout-vent length, SVL) incorporate many synovial intervertebral joints, each allowing flexion and limited extension and compression. Radiographs of the trunk in 14 phylogenetically diverse species in resting and stretched conditions combined with dissections and histological analysis of intervertebral joints show that the synovial nature of these joints underlies the variance in SVL measures. Similarly, the ubiquity and variety of viscoelastic tissues connecting mobile snout and jaw elements of alethinophidian snakes underlie variances in length and width measures of the head. For the overall size of the head and jaw apparatus, the part that can be most easily and relatively precisely measured for many snakes is the mandible because it has only one mobile joint. As to accuracy, the anatomy of intervertebral and cranial joints supports the hypothesis that in living snakes, the head and trunk have no exact size.

A framework for simulating genotype-by-environment interaction using multiplicative models

Key messageThe simulation of genotype-by-environment interaction using multiplicative models provides a general and scalable framework to generate realistic multi-environment datasets and model plant breeding programmes.Plant breeding has been historically shaped by genotype-by-environment interaction (GEI). Despite its importance, however, many current simulations do not adequately capture the complexity of GEI inherent to plant breeding. The framework developed in this paper simulates GEI with desirable structure using multiplicative models. The framework can be used to simulate a hypothetical target population of environments (TPE), from which many different multi-environment trial (MET) datasets can be sampled. Measures of variance explained and expected accuracy are developed to tune the simulation of non-crossover and crossover GEI and quantify the MET-TPE alignment. The framework has been implemented within the R package FieldSimR, and is demonstrated here using two working examples supported by R code. The first example embeds the framework into a linear mixed model to generate MET datasets with low, moderate and high GEI, which are used to compare several popular statistical models applied to plant breeding. The prediction accuracy generally increases as the level of GEI decreases or the number of environments sampled in the MET increases. The second example integrates the framework into a breeding programme simulation to compare genomic and phenotypic selection strategies over time. Genomic selection outperforms phenotypic selection by ∼\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim $$\\end{document}50–70% in the TPE, depending on the level of GEI. These examples demonstrate how the new framework can be used to generate realistic MET datasets and model plant breeding programmes that better reflect the complexity of real-world settings, making it a valuable tool for optimising a wide range of breeding methodologies.

Kinetic Predictors of Weightlifting Performance in Young Weightlifters.

Morris, SJ, Oliver, JL, Pedley, JS, Radnor, JM, Haff, GG, Cooper, S-M, and Lloyd, RS. Kinetic predictors of weightlifting performance in young weightlifters. J Strength Cond Res 38(9): 1551-1560, 2024-Relationships between force-generating capabilities and weightlifting performance ( e.g ., snatch, clean and jerk [C&J], and combined total) have previously been explored in adult weightlifters; however, associations in young athletes are unknown. The purpose of this study was twofold: (a) to examine the relationships between countermovement jump (CMJ) and isometric midthigh pull (IMTP) kinetics and weightlifting performance in young weightlifters and (b) to determine the proportion of weightlifting performance that could be accounted for by CMJ and IMTP kinetics using principal component analysis (PCA). Thirty-seven young weightlifters (12-18 years of age) completed 3 trials of CMJ and 2 trials of the IMTP assessments on dual force plates. Recent competition maximum loads, obtained within 2 weeks of the data collection, for the C&J and snatch were also recorded. Pearson's zero-order correlation coefficients demonstrated moderate to very high correlations ( r = 0.359-0.801; all p ≤ Benjamini-Hochberg critical values [ B-Hα ]) between CMJ kinetic variables, including jump height, average braking force, average braking velocity, absolute and relative braking net impulse, absolute and relative force at minimum displacement, absolute and relative propulsive force, absolute and relative propulsive net impulse and average propulsive velocity, and weightlifting performance. High to very high correlations were evident between IMTP peak force and relative peak force and all weightlifting performance metrics (snatch, C&J, combined total, combined total [kg]/body mass [kg -0.67 ], and Sinclair's total; r = 0.538-0.796; p ≤ B-Hα ). Components from the PCA were used to conduct stepwise, multiple, linear regression analyses. Moderate (45.8-52.9%) and large percentages (79.1-81.3%) of variance in absolute measures of weightlifting performance were explained by IMTP peak force variables and CMJ propulsive variables, respectively. These novel findings indicate that IMTP peak force variables and CMJ propulsive variables could provide valuable insight for talent identification and long-term athletic development in junior weightlifting pathways.

Extended High-Frequency Thresholds: Associations With Demographic and Risk Factors, Cognitive Ability, and Hearing Outcomes in Middle-Aged and Older Adults.

This study had two objectives: to examine associations between extended high-frequency (EHF) thresholds, demographic factors (age, sex, race/ethnicity), risk factors (cardiovascular, smoking, noise exposure, occupation), and cognitive abilities; and to determine variance explained by EHF thresholds for speech perception in noise, self-rated workload/effort, and self-reported hearing difficulties. This study was a retrospective analysis of a data set from the MUSC Longitudinal Cohort Study of Age-related Hearing Loss. Data from 347 middle-aged adults (45 to 64 years) and 694 older adults (≥ 65 years) were analyzed for this study. Speech perception was quantified using low-context Speech Perception In Noise (SPIN) sentences. Self-rated workload/effort was measured using the effort prompt from the National Aeronautics and Space Administration-Task Load Index. Self-reported hearing difficulty was assessed using the Hearing Handicap Inventory for the Elderly/Adults. The Wisconsin Card Sorting Task and the Stroop Neuropsychological Screening Test were used to assess selected cognitive abilities. Pure-tone averages representing conventional and EHF thresholds between 9 and 12 kHz (PTA (9 - 12 kHz) ) were utilized in simple linear regression analyses to examine relationships between thresholds and demographic and risk factors or in linear regression models to assess the contributions of PTA (9 - 12 kHz) to the variance among the three outcomes of interest. Further analyses were performed on a subset of individuals with thresholds ≤ 25 dB HL at all conventional frequencies to control for the influence of hearing loss on the association between PTA (9 - 12 kHz) and outcome measures. PTA (9 - 12 kHz) was higher in males than females, and was higher in White participants than in racial Minority participants. Linear regression models showed the associations between cardiovascular risk factors and PTA (9 - 12 kHz) were not statistically significant. Older adults who reported a history of noise exposure had higher PTA (9 - 12 kHz) than those without a history, while associations between noise history and PTA (9 - 12 kHz) did not reach statistical significance for middle-aged participants. Linear models adjusting for age, sex, race and noise history showed that higher PTA (9 - 12 kHz) was associated with greater self-perceived hearing difficulty and poorer speech recognition scores in noise for both middle-aged and older participants. Workload/effort was significantly related to PTA (9 - 12 kHz) for middle-aged, but not older, participants, while cognitive task performance was correlated with PTA (9 - 12 kHz) only for older participants. In general, PTA (9 - 12 kHz) did not account for additional variance in outcome measures as compared to conventional pure-tone thresholds, with the exception of self-reported hearing difficulties in older participants. Linear models adjusting for age and accounting for subject-level correlations in the subset analyses revealed no association between PTA (9 - 12 kHz) and outcomes of interest. EHF thresholds show age-, sex-, and race-related patterns of elevation that are similar to what is observed for conventional thresholds. The current results support the need for more research to determine the utility of adding EHF thresholds to routine audiometric assessment with middle-aged and older adults.

Exploring the Influence of Extended High-Frequency Hearing on Cochlear Functioning at Lower Frequencies.

Diminished basal cochlear function, as indicated by elevated hearing thresholds in the extended high frequencies (EHFs), has been associated with lower levels of click-evoked and distortion-product otoacoustic emissions measured at lower frequencies. However, stimulus-frequency otoacoustic emissions (SFOAEs) at low-probe levels are reflection-source emissions that do not share the same generation mechanism as distortion-source emissions. The primary objective of the present study was to examine the influence of hearing thresholds in the EHFs on SFOAEs measured at lower frequencies. SFOAEs were recorded from both ears in 45 individuals with normal hearing thresholds in the conventional audiometric frequencies (0.25-8 kHz). Hearing thresholds were also measured at EHFs (10, 12.5, and 16 kHz). SFOAE magnitudes and signal-to-noise ratios (SNRs) were averaged across 1, 2, and 4 kHz probe frequencies and also averaged for high-probe frequencies (2 and 4 kHz). SFOAE magnitudes and SNRs were significantly higher for ears with better EHF hearing relative to poorer EHF hearing, categorized based on the median split. In addition, hearing in the EHFs significantly contributed to the variance in all SFOAE measures, except for the high-frequency SFOAE magnitudes model. However, hearing thresholds at the probe frequencies did not significantly contribute to the variance in SFOAEs. The study findings suggest that alterations in the basal cochlea, as revealed by EHF hearing thresholds, could be associated with diminished cochlear functioning in relatively apical regions, shown by SFOAEs at lower frequencies, in individuals with normal audiograms. These findings underscore the significance of considering EHF thresholds in audiological evaluations, as alterations in these frequencies may reflect broader cochlear health status.