6,989 results on '"repeatability"'
Search Results
2. Microwave-assisted laser-induced breakdown spectroscopy on aluminum alloy for improved quantitation
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Khan, M. Rashad, Haq, S.U., Abbas, Qamar, Khan, Riaz, and Nadeem, Ali
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- 2025
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3. Laser-induced breakdown spectroscopy (LIBS) of animal fat (lard): Efficient sample preparation for onsite analysis and influence of sample temperature on the signal intensity and plasma parameters
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Khan, M. Rashad, Ibrahim, R.K. Raja, Duralim, M., Omer, M.F., and Haq, S.U.
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- 2024
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4. Test–retest repeatability and software reproducibility of myocardial flow measurements using rest/adenosine stress Rubidium-82 PET/CT with and without motion correction in healthy young volunteers
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Byrne, Christina, Kjaer, Andreas, Olsen, Naja Enevold, Forman, Julie Lyng, and Hasbak, Philip
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- 2021
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5. Cardiac SPECT radiomic features repeatability and reproducibility: A multi-scanner phantom study
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Edalat-Javid, Mohammad, Shiri, Isaac, Hajianfar, Ghasem, Abdollahi, Hamid, Arabi, Hossein, Oveisi, Niki, Javadian, Mohammad, Shamsaei Zafarghandi, Mojtaba, Malek, Hadi, Bitarafan-Rajabi, Ahmad, Oveisi, Mehrdad, and Zaidi, Habib
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- 2021
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6. Identifying personality traits and behavioural syndromes in a threatened freshwater fish (Nannoperca vittata) through comparative analysis with a model species (Poecilia reticulata): Implications for conservation.
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Pathirana, Nuwandi U. K., Gleiss, Adrian, Beatty, Stephen J., and Lymbery, Alan J.
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Animal personalities are differences in behaviour among individuals of the same species that are consistent over time and contexts. The integration of animal personality into conservation actions is hampered by limited understanding of personality traits in non‐model organisms. We estimated repeatabilities and correlations between behaviours in Nannoperca vittata (western pygmy perch), a threatened freshwater fish species endemic to south‐western Australia, and, for comparative purposes, in Poecilia reticulata (guppy), a species frequently used in personality research. Each fish was measured four times for each of seven behavioural variables, presumed to reflect five underlying personality traits. Track length (TL) was used as a measure of activity; time spent in a risky zone (RZ) and time to emergence (ET) for boldness; latency to approach a novel object (LA) and time spent close to the object (TS) for exploration; time spent close to a mirror (CV) for sociability and number of attacks at the mirror (AT) for aggression. Four behavioural variables (TL, RZ, ET and CV) were significantly repeatable in N. vittata and also in P. reticulata. There was a lack of concordance in phenotypic and among‐individual correlations between variables in both species, emphasising the importance of partitioning trait covariances to infer behavioural syndromes. Significant among‐individual correlations were found between activity, boldness and sociability variables in N. vittata, consistent with a proactive‐reactive personality axis, but not in P. reticulata. Personality variation should be considered in conservation actions for N. vittata, particularly with respect to unintended consequences of domestication selection in captive breeding and release. [ABSTRACT FROM AUTHOR]
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- 2025
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7. Graphene Oxide Humidity Sensor: Effect of Substrates: Graphene Oxide Humidity Sensor: P. Tiwary et al.
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Tiwary, Punam, Chakraborty, Amit K., Edwards, Holly J., Dhanak, Vinod R., and Mahapatra, Rajat
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A graphene oxide (GO)-based humidity sensor is reported in this work wherein the influence of the substrate on its humidity-sensing properties is compared by depositing a GO film on two different substrates: glass and wearable fabric. While the GO film exhibits sensitivity to humidity for both substrates, its response varies from 35% for the glass substrate to 74% for wearable fabric at 60% relative humidity (RH), clearly indicating the superiority of the wearable fabric over glass. The sensors (on both substrates) show almost no sensitivity to several common volatile organic compounds (VOCs) and gases, suggesting their high selectivity towards humidity. In both cases, the sensor can detect humidity with high repeatability over several cycles and exhibits fast response and recovery times of 6 s/10 s and 7 s/12 s for glass and wearable fabric, respectively. The sensing mechanism is explained in terms of pre-adsorbed surface oxygen ions, as measured by the change in water signal upon exposure of the GO film to humidity using Fourier transform infrared (FTIR) spectroscopy. Thus, we demonstrate that the developed GO film on wearable fabric can act as a low-cost, flexible, and wearable humidity sensor with good sensitivity, reproducibility, and selectivity. [ABSTRACT FROM AUTHOR]
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- 2025
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8. A comprehensive guide to study the agreement and reliability of multi-observer ordinal data.
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Vanbelle, Sophie, Engelhart, Christina Hernandez, and Blix, Ellen
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OPEN source software , *MEASUREMENT errors , *RESEARCH personnel , *SAMPLING (Process) , *CONFIDENCE intervals - Abstract
Background: A recent systematic review revealed issues in regard to performing and reporting agreement and reliability studies for ordinal scales, especially in the presence of more than two observers. This paper therefore aims to provide all necessary information in regard to the choice among the most meaningful and most used measures and the planning of agreement and reliability studies for ordinal outcomes. Methods: This paper considers the generalisation of the proportion of (dis)agreement, the mean absolute deviation, the mean squared deviation and weighted kappa coefficients to more than two observers in the presence of an ordinal outcome. Results: After highlighting the difference between the concepts of agreement and reliability, a clear and simple interpretation of the agreement and reliability coefficients is provided. The large sample variance of the various coefficients with the delta method is presented or derived if not available in the literature to construct Wald confidence intervals. Finally, a procedure to determine the minimum number of raters and patients needed to limit the uncertainty associated with the sampling process is provided. All the methods are available in an R package and a Shiny application to circumvent the limitations of current software. Conclusions: The present paper completes existing guidelines, such as the Guidelines for Reporting Reliability and Agreement Studies (GRRAS), to improve the quality of reliability and agreement studies of clinical tests. Furthermore, we provide open source software to researchers with minimum programming skills. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Toward improving reproducibility in neuroimaging deep learning studies.
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Del Pup, Federico and Atzori, Manfredo
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ARTIFICIAL neural networks ,FUNCTIONAL magnetic resonance imaging ,DIGITAL Object Identifiers ,SCIENTIFIC method ,COMPUTER vision - Abstract
The article discusses the challenges of reproducibility in neuroimaging deep learning studies, emphasizing the importance of sharing source code and datasets to ensure methodological robustness and result trustworthiness. It highlights the lack of reproducibility in many deep learning studies, particularly in neuroimaging, and provides a checklist of 30 key elements necessary for achieving reproducibility. The paper suggests specific locations for presenting these elements without hindering readability and calls for actions from publishers to encourage code and data sharing. The authors stress the need to prioritize reproducibility and generalizability in deep learning studies, especially in sensitive applications like medical research. [Extracted from the article]
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- 2024
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10. Assessing the repeatability, reliability, and precision of right ventricular outflow tract and mid-pulmonary artery diameters, velocity time integrals, and agreement between site-specific stroke volumes.
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Mohseni-Badalabadi, Reza, Hosseininejad, Leila, Hali, Reza, Fallah, Flora, and Hosseinsabet, Ali
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DOPPLER echocardiography ,INTRACLASS correlation ,PULMONARY artery ,PEARSON correlation (Statistics) ,HEART beat - Abstract
Background: Right ventricular (RV) stroke volume (SV) can be calculated via Doppler echocardiography at multiple sites in the right chambers. However, the agreement between the calculated SVs at these sites is unknown. We aimed to assess the repeatability, reliability, and precision of the distal right ventricular outflow tract diameter (RVOTD), the mid-pulmonary artery diameter (MPAD), the right ventricular outflow tract velocity time integral (VTI), and the mid-pulmonary artery velocity time integral (MPAVTI). Additionally, we evaluated the agreement between RVOTSV and MPASV. Methods: Four observers each evaluated approximately 100 patients (n = 406). Basic measurements were made over three cardiac cycles, and the repeatability, reliability, and precision of the measurements were calculated. The agreement between the two methods was presented as intraclass correlation coefficients. Results: The repeatability coefficient ranges for RVOTD, MPAD, RVOTVTI, and MPAVTI were 2–3 mm, 2–4 mm, 2.1–2.8 cm, and 2.4–4.1 cm, respectively. The minimal detectable change ranges for these variables were 2–4 mm, 2–5 mm, 2.2–3.0 cm, and 2.6–4.3 cm, respectively. The respective precision ranges for RVOTD, MPAD, RVOTVTI, and MPAVTI were 2.7–4.7%, 2.4–5.4%, 5.0–7.4%, and 5.4–9.2%. There were significant correlations and agreements between MPASV and RVOTSV, with the Pearson correlation coefficient ranging from 0.63 to 0.89 (P < 0.001). The intraclass correlation coefficient ranged from 0.56 to 0.89 (P < 0.001), although there was a significant bias of 1.9–11.3 mL (P < 0.001). Conclusions: The RVOTD, MPAD, RVOTVTI, and MPAVTI measurements were repeatable, reliable, and precise. The agreement between RVOTSV and MPASV ranged from fair to excellent, although significant bias, along with a wide limit of agreement, was observed. Consequently, these methods cannot be used interchangeably. [ABSTRACT FROM AUTHOR]
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- 2024
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11. Personality expression is shaped by the early experienced social context in predatory mites.
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Chiara, Violette
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PREDATORY mite , *ANIMAL behavior , *SOCIAL isolation , *ANIMAL ecology , *PERSONALITY - Abstract
Research Highlights: Schausberger, P., & Nguyen, T. H. (2024). Early social isolation disrupts adult personality expression in group‐living mites. Journal of Animal Ecology. https://doi.org/10.1111/1365‐2656.14169. Personality traits in animals have been of great interest in the last decades. The number of studies demonstrating the existence of personality in a wide range of taxa is growing rapidly. Although the effect of early experience on later average values of behavioural traits is well documented, very few articles demonstrate the effects of those factors on personality expression itself. One factor in particular received very little, if not no, attention: social isolation. Although social isolation is known to have major impacts on later animal behaviour, it is still unknown whether it may favour or inhibit personality expression. In a recent study, Schausberger and Nguyen (2024) demonstrated that early‐life social isolation had strong effects on adults of the predatory mite Phytoseiulus persimilis. They show for the first time that early social isolation decreased the expression of personality in the activity of adults when tested in a social context. Interestingly, they observed the opposite effect when the same mites were tested alone: previously isolated mites were highly repeatable but group‐reared mites were not. Finally, they also show an indirect effect of early social isolation through mating: mating with a male who experienced social isolation increased the behavioural repeatability of females. This study not only reinforces the established understanding of personality but also paves the way for future research in the field. [ABSTRACT FROM AUTHOR]
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- 2024
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12. Reliability of Sensorimotor Control Tests in Individuals with Adolescent Idiopathic Scoliosis.
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Kastrinis, Alexandros, Strimpakos, Nikolaos, Koumantakis, George A., Tzatzaliaris, Dionysios, Oikonomaki, Marianna, Theodosopoulos, Evangelos, Skaftourou, Evangelia, Tsekoura, Maria, Kanellopoulos, Asimakis K., Nomikou, Eleni, and Dimitriadis, Zacharias
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Background: The presence of sensorimotor control deficits in adolescent idiopathic scoliosis compared to typically developed adolescents is supported by the literature but lacks reliability studies for assessment in this population. This study aimed to assess the reliability of eight sensorimotor control tests, in terms of static and dynamic balance, joint position sense (JPS) tests of the extremities and the spine, and a functional upper extremity proprioceptive test in adolescent idiopathic scoliosis subjects. Methods: Sixty adolescent idiopathic scoliosis subjects were divided into four groups. Each group underwent two tests by the same examiner, repeated at 15 min intervals. Reliability was measured using the intraclass correlation coefficient (ICC), standard error of measurement (SEM), and smallest detectable difference (SDD). Results: The results showed high reliability for the upper extremity functional proprioception test, for the dynamic and static balance test, and for the spinal lateral flexion joint position sense test in both directions. On the other hand, the shoulder external rotation, knee extension, elbow flexion, and spinal flexion joint position sense tests demonstrated poor reliability in adolescent idiopathic scoliosis subjects. Conclusions: Therapists are recommended to use the functional upper extremity proprioception test, the Fukuda test, the static balance test using a force footplate, and the spinal lateral flexion joint position sense test for assessing treatment progress in this population. [ABSTRACT FROM AUTHOR]
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- 2024
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13. The Influence of Accommodative Demand on Ocular Aberrations: A Study of Zernike Coefficients Repeatability and Variability.
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Mechó-García, María, Arcas-Carbonell, María, Orduna-Hospital, Elvira, Sánchez-Cano, Ana, and González-Méijome, José Manuel
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INTRACLASS correlation , *ABERROMETRY , *STATISTICAL reliability , *MONOCULARS , *VOLUNTEERS - Abstract
Purpose: To evaluate the repeatability of the Zernike coefficients in healthy eyes when monocular accommodation was stimulated at different vergences demands. Methods: A total of 36 right eyes from healthy volunteers were prospectively and consecutively recruited for this study. Wavefront aberrometry was conducted to objectively characterize the ocular optical quality during accommodation, from the individual's far point to a 5 D accommodation demand in steps of 0.5 D. The repeatability of Zernike coefficients up to the fourth order was assessed by calculating the within-eye repeatability (Sw), the coefficient of repeatability (CR), the coefficient of variation (CV), and the intraclass correlation coefficient (ICC) as an indicator of measurement reliability. Results: Correlation among repeated measurements showed high reliability (ICC > 0.513) for all parameters measured except some fourth-order Zernike coefficients, C(4, −4) (ICC < 0.766), C(4, −2) (ICC < 0.875), C(4, 2) (ICC < 0.778) and C(4, 4) (ICC < 0.811). Greater repeatability and less variability were obtained for high-order Zernike coefficients (CR < 0.154), although an increase in CR in the coefficients analyzed was observed with increasing accommodative demand. No clear trend was evident in CV; however, it was observed that the low-order Zernike coefficients exhibit lower CV (CV < 1.93) compared to the high-order Zernike coefficients (CV > 0). Conclusions: The reliability of Zernike coefficients up to the fourth order in healthy young individuals demonstrated a strong consistency in measuring terms up to the fourth order, with more variability observed for high-order terms. The Zernike coefficients up to the third order exhibited the highest level of repeatability. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Repeatability of ultrasonographic measurement of cross‐sectional area of the multifidus muscle in the horse.
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Symonds, Nicolle E., Dart, Andrew J., Perkins, Nigel R., Burns, Gillian, Young, Alex C., Bell, Robin J. W., and Jeffcott, Leo B.
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INTRACLASS correlation , *AREA measurement , *BACK muscles , *ULTRASONIC imaging , *BACKACHE - Abstract
Summary: Background: Recent studies have described techniques to acquire ultrasound measurements of the cross‐sectional area of the multifidus muscle to investigate back pain in horses and monitor the response to rehabilitation. These techniques have been extrapolated from human research but have not been clinically validated in the horse. Objective: The objective of the study was to investigate whether measuring the cross‐sectional area of the multifidus muscle in horses using ultrasound is a repeatable technique. Study design: Cross‐sectional. Methods: Ultrasound images of the articular process view and interspinous view of the multifidus muscle were acquired at T15, T18, L2 and L5 on the left and right sides. Three images were acquired at each location and each image was measured three times to give an average cross‐sectional area. Study 1 investigated the repeatability of acquiring images in a single session, and then on two separate days. Study 2 compared measurements of images acquired with a console (Philips EpiQ) and a portable (MyLab™Alpha) ultrasound machine. Study 3 investigated the repeatability of measuring the cross‐sectional area using external software, OsiriX. Intraclass correlation coefficients (ICC) were calculated for each study. Results: Repeatability varied from good to excellent for images taken in a single session. The repeatability for measuring the images using external software was good to excellent. There was poor‐to‐moderate repeatability for images taken on two different days and poor‐to‐good repeatability when using the two different machines. Main limitations: Population size, study population limited to a single breed, only one operator. Conclusions: The measurement of the multifidus muscle in horses has poor repeatability and may have limited application. [ABSTRACT FROM AUTHOR]
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- 2024
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15. Metabolic rate and saliva cortisol concentrations in socially housed adolescent guinea pigs.
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Nemeth, Matthias, Fritscher, Susanna, Füreder, Klara, Wallner, Bernard, and Millesi, Eva
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GUINEA pigs , *SALIVA analysis , *AGE differences , *SWINE , *OXYGEN consumption - Abstract
An individual's energetic demands and hence metabolic rate can strongly change during adolescence, a phase characterized by profound morphological, physiological, and endocrine changes. Glucocorticoid hormones (e.g. cortisol) are released in response to hypothalamic–pituitary–adrenal–axis activity, modulate several metabolic processes, and can also be linked to increased metabolic rate. In domestic guinea pigs (Cavia aperea f. porcellus) housed in same-sex groups, cortisol concentrations increase during adolescence in males but remain stable in females, which was suggested to be related to different energetic demands by age. We therefore measured metabolic rate through oxygen (O2) consumption over 2.5 h in male and female guinea pigs housed in same-sex groups during adolescence at ages of 60, 120, and 180 days, which was paralleled by analyses of saliva cortisol concentrations before and after the measurement. The statistical analyses involved whole body metabolic rate (ml O2/h), body mass-corrected metabolic rate (ml O2/h/kg), and body mass-independent metabolic rate (ml O2/h statistically corrected for body mass). We found increasing cortisol concentrations with age in males only, but none of the three metabolic rate analyses revealed a sex difference by age. On the individual level, repeatability across ages was found in metabolic rate as well as in body mass and cortisol concentrations after the measurement, but not in "basal" cortisol concentrations. Our results suggest no sex-specific changes in metabolic rate and hence equal energetic demands in male and female guinea pigs during adolescence. Moreover, metabolic rate clearly represents a highly stable physiological trait already early in a guinea pig's life irrespective of rather fluctuating cortisol concentrations. [ABSTRACT FROM AUTHOR]
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- 2024
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16. The quantification of bone mineral density using photon counting computed tomography and its implications for detecting bone remodeling.
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Quintiens, Jilmen, Coudyzer, Walter, Bevers, Melissa, Vereecke, Evie, Bergh, Joop P van den, Manske, Sarah L, and Lenthe, G Harry van
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HR-pQCT has become standard practice when quantifying volumetric BMD (vBMD) in vivo. Yet, it is only accessible to peripheral sites, with small fields of view and lengthy scanning times. This limits general applicability in clinical workflows. The goal of this study was to assess the potential of photon counting CT (PCCT) in quantitative bone imaging. Using the European Forearm Phantom, PCCT was calibrated to hydroxyapatite (HA) density. Eight cadaveric forearms were scanned twice with PCCT and once with HR-pQCT. The dominant forearm of two volunteers was scanned twice with PCCT. In each scan, the carpals were delineated. At bone level, accuracy was assessed with a paired measurement of total vBMD (Tt.vBMD) calculated with PCCT and HR-pQCT. At voxel-level, repeatability was assessed by image registration and voxel-wise subtraction of the ex vivo PCCT scans. In an ideal scenario, this difference would be zero; any deviation was interpreted as falsely detected remodeling. For clinical usage, the least detectable remodeling was determined by finding a threshold in the PCCT difference image that resulted in a classification of bone formation and resorption below acceptable noise levels (<0.5%). The paired measurement of Tt.vBMD had a Pearson correlation of 0.986. Compared to HR-pQCT, PCCT showed a bias of 7.46 mgHA/cm
3 . At voxel-level, the repeated PCCT scans showed a bias of 17.66 mgHA/cm3 and a standard error of 96.23 mgHA/cm3 . Least detectable remodeling was found to be 250 mgHA/cm3 , for which 0.37% of the voxels was incorrectly classified as newly added or resorbed bone. In vivo , this volume increased to 0.97%. Based on the cadaver data, we conclude that PCCT can be used to quantify vBMD and bone turnover. We provided proof of principle that this technique is also accurate in vivo , hence, that it has high potential for clinical applications. [ABSTRACT FROM AUTHOR]- Published
- 2024
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17. Repeatability of different mobile phone applications for color measurement in dentistry.
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Dang, Anh Duong, Belles, Donald M., Gonzalez, Maria D., Aponte‐Wesson, Ruth A., and Paravina, Rade D.
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ANALYSIS of colors ,COLORIMETRY ,DENTAL materials ,CELL phones ,MOBILE apps - Abstract
Purpose: To assess the repeatability of various color‐measuring mobile phone applications (MPAs) on dental materials in clinically relevant shades in 1‐mm thickness. Materials and Methods: A benchtop spectrophotometer was used as a reference instrument. Seven MPAs were used: Color Analysis, Color Analyzer—Iro Shirabe, Color Grab, and Colorimeter from Android, and Color Analyzer—Iro Shirabe, ColorMeter RGB, and Optishade from iOS. Color measurements were performed on 1‐mm thickness slices of CAD‐CAM materials, Vita Enamic shades 1M2, 2M2, 3M2, 4M2, and Vitablocs Mark II shades A1C, A2C, A3C, A4C (n = 10, for a total 80 specimens). The specimens were measured at three time periods, Day 0, Day 1, and Day 7, and three measurements were made on each day, to mimic short‐, medium‐, and long‐term repeatability. The color differences were analyzed using the CIEDE2000 formula, with the corresponding color difference (ΔE00), and mean color difference from the mean (MCDM00). One‐way ANOVA, Repeated measures ANOVA, and Paired sample t‐tests were used for statistical analysis. Results: Optishade from iOS showed the lowest mean color difference among the MPAs (ΔE00 = 0.2 (SD 0.1), 0.3 (SD 0.2), and 0.2 (SD 0.1) at Day 0, 1, and 7, respectively, and ΔE00 = 0.5 (SD 0.3) for all three periods Days 0–1, 0–7, and 1–7). Material‐dependent variations in the repeatability of color measurements were observed. Conclusion: There was a statistically significant difference among color measurements using MPAs and a spectrophotometer, among the MPAs, and materials. The spectrophotometer exhibited the highest repeatability across the tested time periods. The iOS Optishade showed the highest repeatability among the MPAs. [ABSTRACT FROM AUTHOR]
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- 2024
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18. Signal drift in diffusion MRI of the brain: effects on intravoxel incoherent motion parameter estimates.
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Jalnefjord, Oscar, Rosenqvist, Louise, Warsame, Amina, and Björkman-Burtscher, Isabella M.
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DIFFUSION magnetic resonance imaging ,ACCOUNTING methods ,STATISTICAL reliability ,MAGNETIC resonance imaging ,POLYNOMIALS - Abstract
Objectives: Signal drift has been put forward as one of the fundamental confounding factors in diffusion MRI (dMRI) of the brain. This study characterizes signal drift in dMRI of the brain, evaluates correction methods, and exemplifies its impact on parameter estimation for three intravoxel incoherent motion (IVIM) protocols. Materials and methods: dMRI of the brain was acquired in ten healthy subjects using protocols designed to enable retrospective characterization and correction of signal drift. All scans were acquired twice for repeatability analysis. Three temporal polynomial correction methods were evaluated: (1) global, (2) voxelwise, and (3) spatiotemporal. Effects of acquisition order were simulated using estimated drift fields. Results: Signal drift was around 2% per 5 min in the brain as a whole, but reached above 5% per 5 min in the frontal regions. Only correction methods taking spatially varying signal drift into account could achieve effective corrections. Altered acquisition order introduced both systematic changes and differences in repeatability in the presence of signal drift. Discussion: Signal drift in dMRI of the brain was found to be spatially varying, calling for correction methods taking this into account. Without proper corrections, choice of protocol can affect dMRI parameter estimates and their repeatability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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19. Repeatability of alkaline inorganic phosphate quantification in the skeletal muscle using 31P‐magnetic resonance spectroscopy at 3 T.
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Matias, Alexs A., Serviente, Corinna F., Decker, Stephen T., Erol, Muhammet Enes, Giuriato, Gaia, Le Fur, Yann, Nagarajan, Rajakumar, Bendahan, David, and Layec, Gwenael
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NUCLEAR magnetic resonance spectroscopy ,QUADRICEPS muscle ,SKELETAL muscle ,STATISTICAL reliability ,STATISTICAL correlation - Abstract
The detection of a secondary inorganic phosphate (Pi) resonance, a possible marker of mitochondrial content in vivo, using phosphorus magnetic resonance spectroscopy (31P‐MRS), poses technical challenges at 3 Tesla (T). Overcoming these challenges is imperative for the integration of this biomarker into clinical research. To evaluate the repeatability and reliability of measuring resting skeletal muscle alkaline Pi (Pialk) using with 31P‐MRS at 3 T. After an initial set of experiments on five subjects to optimize the sequence, resting 31P‐MRS of the quadriceps muscles were acquired on two visits (~4 days apart) using an intra‐subjects design, from 13 sedentary to moderately active young male and female adults (22 ± 3 years old) within a whole‐body 3 T MR system. Measurement variability attributed to changes in coil position, shimming procedure, and spectral analysis were quantified. 31P‐MRS data were acquired with a 31P/‐proton (1H) dual‐tuned surface coil positioned on the quadriceps using a pulse‐acquire sequence. Test–retest absolute and relative repeatability was analyzed using the coefficient of variation (CV) and intra‐class correlation coefficients (ICC), respectively. After sequence parameter optimization, Pialk demonstrated high intra‐subject repeatability (CV: 10.6 ± 5.4%, ICC: 0.80). Proximo‐distal change in coil position along the length of the quadriceps introduced Pialk quantitation variability (CV: 28 ± 5%), due to magnetic field inhomogeneity with more distal coil locations. In contrast, Pialk measurement variability due to repeated shims from the same muscle volume (0.40 ± 0.09mM; CV: 6.6%), and automated spectral processing (0.37 ± 0.01mM; CV: 2.3%), was minor. The quantification of Pialk in skeletal muscle via surface coil 31P‐MRS at 3 T demonstrated excellent reproducibility. However, caution is advised against placing the coil at the distal part of the quadriceps to mitigate shimming inhomogeneity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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20. Slice‐specific B1+ shimming improves the repeatability of multishot DWI at 7 T.
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Ding, Belinda, Williams, Sydney Nicole, Dragonu, Iulius, Liebig, Patrick, Allwood‐Spiers, Sarah, McElhinney, Paul, Gunamony, Shajan, Fullerton, Natasha, and Porter, David Andrew
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IMAGE transmission ,STATISTICAL reliability ,HOMOGENEITY ,UNIFORMITY ,MAGNETIC resonance imaging - Abstract
Purpose: Compared with lower field strengths, DWI at 7 T faces the combined challenges of increased distortion and blurring due to B0 inhomogeneity, and increased signal dropouts due to B1+ inhomogeneity. This study addresses the B1+ limitations using slice‐specific static parallel transmission (pTx) in a multi‐shot, readout‐segmented EPI diffusion imaging sequence. Methods: DWI was performed in 7 healthy subjects using MRI at 7 T and readout‐segmented EPI. Data were acquired with non‐pTx circular‐polarized (CP) pulses (CP‐DWI) and static pTx pulses (pTx‐DWI) using slice‐specific B1+ shim coefficients. Each volunteer underwent two scan sessions on the same day, with two runs of each sequence in the first session and one run in the second. The sequences were evaluated by assessing image quality, flip‐angle homogeneity, and intrasession and intersession repeatability in ADC estimates. Results: pTx‐DWI significantly reduced signal voids compared with CP‐DWI, particularly in inferior brain regions. The use of pTx also improved RF uniformity and symmetry across the brain. These effects translated into improved intrasession and intersession repeatability for pTx‐DWI. Additionally, re‐optimizing the pTx pulse between repeat scans did not have a negative effect on ADC repeatability. Conclusion: The study demonstrates that pTx provides a reproducible image‐quality increase in multishot DWI at 7 T. The benefits of pTx also extend to quantitative ADC estimation with regard to the improvement in intrasession and intersession repeatability. Overall, the combination of multishot imaging and pTx can support the development of reliable, high‐resolution DWI for clinical studies at 7 T. [ABSTRACT FROM AUTHOR]
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- 2024
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21. Machine learning in laser-induced breakdown spectroscopy: A review.
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Hao, Zhongqi, Liu, Ke, Lian, Qianlin, Song, Weiran, Hou, Zongyu, Zhang, Rui, Wang, Qianqian, Sun, Chen, Li, Xiangyou, and Wang, Zhe
- Abstract
Laser-induced breakdown spectroscopy (LIBS) is a spectroscopic analytic technique with great application potential because of its unique advantages for online/in-situ detection. However, due to the spatially inhomogeneity and drastically temporal varying nature of its emission source, the laser-induced plasma, it is difficult to find or hard to generate an appropriate spatiotemporal window for high repeatable signal collection with lower matrix effects. The quantification results of traditional physical principle based calibration model are unsatisfactory since these models were not able to compensate for complicate matrix effects as well as signal fluctuation. Machine learning is an emerging approach, which can intelligently correlated the complex LIBS spectral data with its qualitative or/and quantitative composition by establishing multivariate regression models with greater potential to reduce the impacts of signal fluctuation and matrix effects, therefore achieving relatively better qualitative and quantitative performance. In this review, the progress of machine learning application in LIBS is summarized from two main aspects: i) Pre-processing data for machine learning model, including spectral selection, variable reconstruction, and denoising to improve qualitative/quantitative performance; ii) Machine learning methods for better quantification performance with reduction of the impact of matrix effect as well as LIBS spectra fluctuations. The review also points out the issues that researchers need to address in their future research on improving the performance of LIBS analysis using machine learning algorithms, such as restrictions on training data, the disconnect between physical principles and algorithms, the low generalization ability and massive data processing ability of the model. [ABSTRACT FROM AUTHOR]
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- 2024
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22. Scan strategy optimization and repeatability testing during laser powder bed fusion additive manufacturing of AlSi10Mg.
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Mishra, Ashish Kumar and Kumar, Arvind
- Abstract
Scan strategy plays a key role in the densification of laser powder bed fusion (LPBF) processed materials. Still, it garnered less attention from researchers worldwide doing parameter optimization who focus more on quantitative parameters like laser power and scan speed. The repeatability of the LPBF process is also not studied widely, despite being a vital factor in furthering its industrial application. Keeping these gaps in mind, this study investigates the effects of various scan strategies on the densification behavior during LPBF processing of AlSi10Mg. Multiple cubic samples are manufactured using different scan strategies and their relative density analyzed. For each scan strategy, the values of laser power, scan speed and scan spacing were changed as well to provide a comprehensive picture. It was observed that the relative density of the samples increased as more lateral motion was added to the laser path, increasing the lateral overlapping of the tracks. The optical microscopic studies were conducted as well on the polished samples to understand the pore characteristics and microstructural effects of scan strategy variation, which showed that increased lateral motion not only reduced the porosity but altered pore geometry and other characteristics as well. Finally, using the optimized process parameters and scan strategy, multiple samples are manufactured and relative density was calculated to check the repeatability of the process. It was seen that the LPBF process is a highly non-repeatable process as the mean density observed was 99.5126% with mean absolute deviation of 0.1946% and standard deviation of 0.2376%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. A Comparative Study of Three Systems for Liver Magnetic Resonance Elastography.
- Author
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Wang, Runke, Wang, Yikun, Qiu, Suhao, Ma, Shengyuan, Yan, Fuhua, Yang, Guang‐Zhong, Li, Ruokun, and Feng, Yuan
- Subjects
INTRACLASS correlation ,MAGNETIC resonance ,MULTIPLE comparisons (Statistics) ,STATISTICAL reliability ,LIVER diseases - Abstract
Background: Different MR elastography (MRE) systems may produce different stiffness measurements, making direct comparison difficult in multi‐center investigations. Purpose: To assess the repeatability and reproducibility of liver stiffness measured by three typical MRE systems. Study Type: Prospective. Population/Phantoms: Thirty volunteers without liver disease history (20 males, aged 21–28)/5 gel phantoms. Field Strength/Sequence: 3.0 T United Imaging Healthcare (UIH), 1.5 T Siemens Healthcare, 3.0 T General Electric Healthcare (GE)/Echo planar imaging‐based MRE sequence. Assessment: Wave images of volunteers and phantoms were acquired by three MRE systems. Tissue stiffness was evaluated by two observers, while phantom stiffness was assessed automatically by code. The reproducibility across three MRE systems was quantified based on the mean stiffness of each volunteer and phantom. Statistical Tests: Intraclass correlation coefficients (ICC), coefficients of variation (CV), and Bland–Altman analyses were used to assess the interobserver reproducibility, the interscan repeatability, and the intersystem reproducibility. Paired t‐tests were performed to assess the interobserver and interscan variation. Friedman tests with Dunn's multiple comparison correction were performed to assess the intersystem variation. P values less than 0.05 indicated significant difference. Results: The reproducibility of stiffness measured by the two observers demonstrated consistency with ICC > 0.92, CV < 4.32%, Mean bias < 2.23%, and P > 0.06. The repeatability of measurements obtained using the electromagnetic system for the liver revealed ICC > 0.96, CV < 3.86%, Mean bias < 0.19%, P > 0.90. When considering the range of reproducibility across the three systems for liver evaluations, results ranged with ICCs from 0.70 to 0.87, CVs from 6.46% to 10.99%, and Mean biases between 1.89% and 6.30%. Phantom studies showed similar results. The values of measured stiffness differed across all three systems significantly. Data Conclusion: Liver stiffness values measured from different MRE systems can be different, but the measurements across the three MRE systems produced consistent results with excellent reproducibility. Evidence Level: 1 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. 31P MR Spectroscopy in the Pancreas: Repeatability, Comparison With Liver, and Pilot Pancreatic Cancer Data.
- Author
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Seelen, Leonard W.F., van den Wildenberg, Lieke, Gursan, Ayhan, Froeling, Martijn, Gosselink, Mark W.J.M., van der Kemp, Wybe J.M., Haj Mohammad, Nadia, Molenaar, I. Quintus, van Santvoort, Hjalmar C., Klomp, Dennis W.J., and Prompers, Jeanine J.
- Subjects
PANCREATIC duct ,SPECTROSCOPIC imaging ,PANCREATIC cancer ,PANCREAS ,MAGNETIC resonance imaging - Abstract
Background: Non‐invasive evaluation of phosphomonoesters (PMEs) and phosphodiesters (PDEs) by 31‐phosphorus MR spectroscopy (31P MRS) may have potential for early therapy (non‐)response assessment in cancer. However, 31P MRS has not yet been applied to investigate the human pancreas in vivo. Purpose: To assess the technical feasibility and repeatability of 31P MR spectroscopic imaging (MRSI) of the pancreas, compare 31P metabolite levels between pancreas and liver, and determine the feasibility of 31P MRSI in pancreatic cancer. Study Type: Prospective cohort study. Population: 10 healthy subjects (age 34 ± 12 years, four females) and one patient (73‐year‐old female) with pancreatic ductal adenocarcinoma. Field Strength/Sequence: 7‐T, 31P FID‐MRSI, 1H gradient‐echo MRI. Assessment: 31P FID‐MRSI of the abdomen (including the pancreas and liver) was performed with a nominal voxel size of 20 mm (isotropic). For repeatability measurements, healthy subjects were scanned twice on the same day. The patient was only scanned once. Test–retest 31P MRSI data of pancreas and liver voxels (segmented on 1H MRI) of healthy subjects were quantified by fitting in the time domain and signal amplitudes were normalized to γ‐adenosine triphosphate. In addition, the PME/PDE ratio was calculated. Metabolite levels were averaged over all voxels within the pancreas, right liver lobe and left liver lobe, respectively. Statistical Tests: Repeatability of test–retest data from healthy pancreas was assessed by paired t‐tests, Bland–Altman analyses, and calculation of the intrasubject coefficients of variation (CoVs). Significant differences between healthy pancreas and right and left liver lobes were assessed with a two‐way analysis of variance (ANOVA) for repeated measures. A P‐value <0.05 was considered statistically significant. Results: The intrasubject CoVs for PME, PDE, and PME/PDE in healthy pancreas were below 20%. Furthermore, PME and PME/PDE were significantly higher in pancreas compared to liver. In the patient with pancreatic cancer, qualitatively, elevated relative PME signals were observed in comparison with healthy pancreas. Data Conclusion: In vivo31P MRSI of the human healthy pancreas and in pancreatic cancer may be feasible at 7 T. Evidence Level: 3 Technical Efficacy: Stage 2 [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Pilot Study on Postoperative Toric Intraocular Lens Alignment: Comparing Casia2 and Photoshop Imaging Techniques.
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Yang, Baodi, Lai, Chunxin, Qin, Yongjie, Lin, Hongliang, Wang, Sheng, Liao, Hailan, Zhang, Hongyang, and Benito, Antonio
- Subjects
- *
CORNEA diseases , *PROSTHETICS , *RESEARCH funding , *CATARACT surgery , *INTRAOCULAR lenses , *PILOT projects , *OPTICAL coherence tomography , *ARTIFICIAL implants , *TREATMENT effectiveness , *RETROSPECTIVE studies , *PHOTOGRAPHY , *INTRACLASS correlation , *SLIT lamp microscopy , *POSTOPERATIVE period , *PUPIL (Eye) , *CONFIDENCE intervals , *REGRESSION analysis - Abstract
Purpose: Assess the comparative accuracy and reliability of postoperative toric intraocular lens (TIOL) alignment measurement methods: Casia2 and Adobe Photoshop with digital slit lamp images (PS method). Methods: In a study of 41 subjects with 58 eyes postimplantation of TIOL, we independently measured TIOL alignment with Casia2 and PS methods. The intraclass correlation coefficient (ICC1,1) was employed to assess the repeatability of the Casia2 method. While ICC2,1 for absolute agreement and Bland–Altman analysis were utilized to determine the interdevice agreement between the two methods, the regression analysis was conducted to identify any proportional bias. Results: Casia2 demonstrated excellent intradevice repeatability with an ICC1,1 of 0.998. The absolute agreement between Casia2 and PS was very high with an ICC2,1 of 0.999. The average discrepancy between the two measurement methods was −0.828°, with a 95% confidence interval (CI) ranging from −1.623° to −0.032°. The 95% limits of agreement (LoA) were between −6.761° and 5.105°, indicating a strong concordance in TIOL alignment measurements. Casia2 was capable of accurately measuring the TIOL axis alignment under conditions of pupil diameters (PDs) of 4 mm or greater. Conclusion: Casia2 and PS demonstrated significant concordance in measuring postoperative TIOL alignment, with Casia2 offering a more straightforward and accessible alternative, particularly beneficial for patients with suboptimal pupil dilation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. The repeatability of behavioural laterality during nest building in zebra finches.
- Author
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Camacho-Alpízar, Andrés, Hewitt, Jessica, Poole, Cailyn, Eckersley, Tristan, Whittaker, Benjamin A., Self, Julia L., and Guillette, Lauren M.
- Subjects
- *
ZEBRA finch , *MATE selection , *NEST building , *LATERAL dominance , *STATISTICAL reliability - Abstract
Cerebral laterality is a widespread phenomenon across animals and refers to the specialization of the left and right hemispheres of the brain for perceptual, cognitive and behavioural tasks. Behavioural laterality occurs in several contexts, including foraging, mate selection, predator detection and tool manufacture. Behavioural laterality during nest building, however, has rarely been addressed. We conducted two experiments to examine (1) whether behavioural laterality occurs during nest building, (2) whether laterality correlates with nest-building speed, (3) whether laterality during nest building is repeatable, and (4) whether nest-building experience influences laterality. In Experiment 1, we scored individual laterality indices for 58 zebra finch (Taeniopygia guttata) males, the nest-building sex in this species, based on which eye he used to view then select the first 25 pieces of nest material. We calculated correlations between laterality strength and nest-building duration. In Experiment 2, to test the repeatability of laterality during nest building, we measured laterality for 20 males across five nests built by each male. Individuals varied both in the direction and the strength of behavioural laterality of material selection during nest building. Overall, however, males were not consistent in their laterality across the five nests. We found no correlation between laterality strength and nest-building duration in either experiment. Finally, we found evidence for building experience influencing the behavioural laterality of individuals: more building experience results in more predictable behavioural laterality during nest-material selection. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Repeatability and agreement of multispectral refraction topography in school children before and after cycloplegia.
- Author
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Xu, Xiaoli, Zang, Wansheng, Wang, Anken, and Yang, Chenhao
- Subjects
- *
INTRACLASS correlation , *CHILD patients , *SCHOOL children , *REFRACTIVE errors , *STATISTICAL reliability - Abstract
Background: The purpose of this study was to evaluate the repeatability and agreement of multispectral refraction topography (MRT) in measuring retinal refraction before and after cycloplegia in children. The results of this study will provide valuable insights into the accuracy and reliability of MRT as a tool for assessing retinal refraction in pediatric patients. Methods: Children aged 7 to 18 years old were recruited for this prospective research. The central and peripheral retinal refraction was measured three times using multispectral refraction topography (MRT) before and after cycloplegia. The retinal deviation value (RDV) was used to describe the average peripheral refractive error of the retina. In addition, objective refraction (OR) and subjective refraction (SR) measurements were also performed. Results: A total of 60 children with a mean age of 10.50 ± 1.81 years were enrolled. Before cycloplegia, all the central and peripheral retinal refraction parameters showed good repeatability with the lowest intraclass correlation coefficient (ICC) being 0.78 in the retinal deviation value from 45° eccentricity to 53° of the retina (RDV 45–53). After cycloplegia, the repeatability of MRT was significantly enhanced (lowest ICC = 0.91 in RDV-I). The 95% limits of agreement (LoA) of the central refraction and OR ranged from − 2.1 to 1.8 D before cycloplegia, and from − 1.69 to 0.27 D after cycloplegia. The 95% LoA of the central refraction and SR ranged from − 1.57 to 0.36 D after cycloplegia. All the 95% LoA demonstrated high agreement. Conclusions: The MRT shows high agreement with autorefractometry and experienced optometrist in measuring central refraction. Additionally, the MRT provides good repeatable measurements of retinal peripheral refraction before and after cycloplegia in schoolchildren. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. A visual guide for the Brabant index to score dental macrowear quantity and direction.
- Author
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Olszewski, Judyta, Hemingway, Jason, and Gibbon, Victoria E.
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- *
TOOTH abrasion , *PHYSICAL anthropology , *HOLOCENE Epoch , *ARCHAEOLOGICAL human remains , *STATISTICS , *DENTAL anthropology - Abstract
This study aimed to reduce subjectivity bias in scoring dental macrowear quantity and direction using the Brabant index, which previously relied solely on written descriptions. To achieve this, we present a new, optimized visual guide incorporating buccal and lingual scores. The optimization process involved conceptualizing and illustrating a visual guide using Holocene southern African hunter‐gatherer and herder teeth, featuring both buccal and lingual scores for multicuspid teeth. The guide was hand‐drawn using a stippling technique and digitized to depict surface details for each wear stage and tooth type. We conducted intra‐ and inter‐observer assessments to evaluate the optimized method using both the original and optimized Brabant indices. Statistical analysis was performed in R using Cohen's kappa for direction and Cohen's weighted kappa for quantity. Intra‐observer results for the original method yielded kappa values of 0.84 for direction and 0.94 for quantity, while the optimized version both resulted in improved values of 0.99. Inter‐observer results revealed some differences between an inexperienced and an experienced observer. The inexperienced observer achieved kappa scores of 0.20 for direction and 0.86 for quantity with the original method, and 0.17 and 0.80, respectively, with the optimized version. The experienced observer's results using the original index were 0.66 for direction and 0.89 for quantity, and 0.75 and 0.96, respectively, with the optimized version. These findings demonstrate that the optimized method enhances data reliability for experienced observers, highlighting the value of a published visual guide and multicuspid scoring adjustments. However, reduced or unappreciable changes in accuracies for the inexperienced observer illustrate the need for dental expertise when scoring for dental wear, even with a modified method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Enhancing the Reliability of NO 2 Monitoring Using Low-Cost Sensors by Compensating for Temperature and Humidity Effects.
- Author
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Alejo Sánchez, Daniellys, Schalm, Olivier, Álvarez Cruz, Arianna, Hernández Rodríguez, Erik, Martínez Laguardia, Alain, Kairuz Cabrera, David, and Morales Pérez, Mayra C.
- Subjects
- *
AIR pollutants , *ELECTROCHEMICAL sensors , *HUMIDITY , *TEMPERATURE effect , *PLASTIC containers - Abstract
The study investigates methods to enhance the reliability of NO2 monitoring using low-cost electrochemical sensors to measure gaseous pollutants in air by addressing the impacts of temperature and relative humidity. The temperature within a plastic container was controlled using an internal mica heater, an external hot air blower, or cooling packs, while relative humidity was adjusted using glycerine solutions. Findings indicated that the auxiliary electrode signal is susceptible to temperature and moderately affected by relative humidity. In contrast, the working electrode signal is less affected by temperature and relative humidity; however, adjustments are still required to determine gas concentrations accurately. Tests involving on/off cycles showed that the auxiliary electrode signal experiences exponential decay before stabilizing, requiring the exclusion of initial readings during monitoring activities. Additionally, calibration experiments in zero air allowed the determination of the compensation factor nT across different temperatures and humidity levels. These results highlight the importance of compensating for temperature and humidity effects to improve the accuracy and reliability of NO2 measurements using low-cost electrochemical sensors. This refinement makes the calibration applicable across a broader range of environmental conditions. However, the experiments also show a lack of repeatability in the zero air calibration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Variability of flow-mediated dilation across lower and upper limb conduit arteries.
- Author
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Daniele, Alessio, Lucas, Samuel J. E., and Rendeiro, Catarina
- Subjects
- *
BRACHIAL artery , *PERIPHERAL vascular diseases , *FEMORAL artery , *INTRACLASS correlation , *ENDOTHELIUM diseases - Abstract
Endothelial dysfunction is an early predictor of atherosclerosis and cardiovascular disease. Flow-mediated dilation (FMD) is the gold standard to assess endothelial function in humans. FMD reproducibility has been mainly assessed in the brachial artery (BA) with limited research in lower limb arteries. The purpose of this study was to compare FMD reproducibility in the upper limb BA and lower limb superficial femoral artery (SFA) in young healthy adults. Fifteen young healthy adults (nine males; six females) underwent FMD, resting diameter, velocity, and shear rate measurements on three occasions to determine intra-and inter-day reproducibility in both BA and SFA, assessed by coefficient of variation (CV), intraclass correlation coefficient (ICC), and Bland–Altman plots. BA FMD CVs (intra-day: 4.2%; inter-day: 8.7%) and ICCs (intra-day: 0.967; inter-day: 0.903) indicated excellent reproducibility and reliability, while for SFA FMD, both CVs (intra-day: 11.6%; inter-day: 26.7%) and ICCs (intra-day: 0.898; inter-day: 0.651) showed good/moderate reproducibility and reliability. BA FMD was significantly more reproducible than SFA FMD (p < 0.05). Diameter reproducibility was excellent and similar between arteries, while resting velocity and shear rate have lower reproducibility in the BA compared to SFA. Bland–Altman plots displayed no proportional and fixed bias between measurements. In summary, SFA FMD is less reproducible than BA FMD, with identical volume of ultrasound training. Given the increasing interest in using SFA FMD to test the efficacy of interventions targeting lower limb's vascular health and as a potential biomarker for peripheral arterial disease risk, future studies should ensure higher levels of training for adequate reproducibility. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. The Development and Reliability of a Surface Electromyography-Based Index for Quantifying Knee Muscle Coactivation During the Lower Quarter Y-Balance Test.
- Author
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Daszkiewicz, Maciej, Prill, Robert, Reichert, Paweł, Becker, Roland, Oleksy, Łukasz, Kuźniecow, Mateusz, Lech, Marcin, Kułakowski, Michał, Kentel, Monika, Kentel, Maciej, Kowal, Mateusz, Dejnek, Maciej, and Królikowska, Aleksandra
- Subjects
KNEE muscles ,BICEPS femoris ,VASTUS lateralis ,VASTUS medialis ,REPEATED measures design ,KNEE - Abstract
This study aimed to develop and evaluate the reliability of a surface electromyography-based (sEMG) index to quantify knee muscle coactivation in healthy recreational athletes during the Lower Quarter Y-Balance Test (YBT-LQ). A prospective observational repeated measures design was used to assess both intra- and inter-rater reliability. Forty males completed three trials, with two raters independently conducting assessments. sEMG signals from the vastus medialis, vastus lateralis, biceps femoris, and semitendinosus muscles were collected to calculate four coactivation indices (CoAIs) for different muscle pairs. The reliability evaluation of these CoAIs was based on intraclass correlation coefficients. The results revealed that the reliability of the CoAIs varied depending on the muscle pair, direction, and limb examined. The highest intra- and inter-rater reliability was noted for the left lower limb in the posterolateral direction. The lowest reliability was found for the right lower limb in the anterior direction. Statistical analyses indicated significant differences in specific CoAIs across different YBT-LQ directions. These findings highlight the potential of sEMG-based CoAIs for assessing knee muscle activity during the YBT-LQ in healthy male recreational athletes. However, choosing CoAIs is critical for reliable clinical and research assessments of knee stability and neuromuscular control. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Bayesian approach for assessment of co-variances and genetic parameters of production and reproduction traits in Sahiwal cattle.
- Author
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Ratwan, Poonam, Kumar, Manoj, and Chakravarty, A. K.
- Abstract
Precise as well as unbiased estimates of genetic parameters of economically important traits is important for framing breeding programmes meant for genetic progress of dairy animals. Present work was carried out to assess the co-variances along with genetic parameters of production and reproduction traits in Sahiwal cattle with Bayesian approach. Records of Sahiwal cattle kept at ICAR-National Dairy Research Institute, Karnal, Haryana for the period 1988–2016 were used. Heritability estimates ± posterior standard deviation for 305 days’ milk yield (305DMY), lactation milk yield (LMY), lactation length (LL), peak yield (PY), days to attain peak yield (DPY), dry period (DP), gestation period (GP), calving to first insemination interval (CFI), days open (DO) and calving interval (CI) as obtained were 0.23 ± 0.03, 0.26 ± 0.03, 0.18 ± 0.03, 0.18 ± 0.03, 0.07 ± 0.02, 0.08 ± 0.02, 0.08 ± 0.02, 0.07 ± 0.02, 0.09 ± 0.02 and 0.02 ± 0.02, respectively and estimates of repeatability for the corresponding traits were 0.23 ± 0.03, 0.26 ± 0.03, 0.21 ± 0.03, 0.21 ± 0.03, 0.12 ± 0.02, 0.14 ± 0.03, 0.16 ± 0.03, 0.16 ± 0.03, 0.17 ± 0.03 and 0.17 ± 0.03. Moderate heritability values for 305DMY and LMY implies that sufficient additive genetic variability is available to obtain selection response. Repeatability estimates for 305DMY, LMY and PY were moderate, pointing towards the possibility of early appraisal of Sahiwal cattle for selection. Antagonistic genetic associations were observed between reproduction and production traits suggesting that reproduction traits need due attention while selecting high producing Sahiwal animals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
33. VERIFICATION OF THE PROPERTIES OF AN INDUSTRIAL ROBOT FOR THE NUCLEAR INDUSTRY.
- Author
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SEMJON, JAN, VARGA, JOZEF, PILAT, PATRIK, MARCINKO, PETER, and JANOS, RUDOLF
- Subjects
INDUSTRIAL robots ,ROBOT design & construction ,ROBOT industry ,NUCLEAR industry ,IONIZING radiation - Abstract
The article deals with the issue of verification of selected geometric characteristics of a special robot intended for the nuclear industry. The design of the robot is specific in that the robot works in both semi-automatic and manual mode. This leads to frequent collisions of some parts of the robot with fragmented equipment. Therefore, it was necessary to ensure the accuracy and repeatability of the robot after its production and during its operation. Verification of the parameters of the robot after one year of operation was carried out in the controlled zone of the nuclear power plant, which was specific due to the presence of ionizing radiation. The methodology, technique and method of verification had to be adapted to this. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. Assessing the repeatability, reliability, and precision of right ventricular outflow tract and mid-pulmonary artery diameters, velocity time integrals, and agreement between site-specific stroke volumes
- Author
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Reza Mohseni-Badalabadi, Leila Hosseininejad, Reza Hali, Flora Fallah, and Ali Hosseinsabet
- Subjects
Right ventricular outflow tract ,Pulmonary artery ,Echocardiography ,Stroke volume ,Agreement ,Repeatability ,Diseases of the circulatory (Cardiovascular) system ,RC666-701 - Abstract
Abstract Background Right ventricular (RV) stroke volume (SV) can be calculated via Doppler echocardiography at multiple sites in the right chambers. However, the agreement between the calculated SVs at these sites is unknown. We aimed to assess the repeatability, reliability, and precision of the distal right ventricular outflow tract diameter (RVOTD), the mid-pulmonary artery diameter (MPAD), the right ventricular outflow tract velocity time integral (VTI), and the mid-pulmonary artery velocity time integral (MPAVTI). Additionally, we evaluated the agreement between RVOTSV and MPASV. Methods Four observers each evaluated approximately 100 patients (n = 406). Basic measurements were made over three cardiac cycles, and the repeatability, reliability, and precision of the measurements were calculated. The agreement between the two methods was presented as intraclass correlation coefficients. Results The repeatability coefficient ranges for RVOTD, MPAD, RVOTVTI, and MPAVTI were 2–3 mm, 2–4 mm, 2.1–2.8 cm, and 2.4–4.1 cm, respectively. The minimal detectable change ranges for these variables were 2–4 mm, 2–5 mm, 2.2–3.0 cm, and 2.6–4.3 cm, respectively. The respective precision ranges for RVOTD, MPAD, RVOTVTI, and MPAVTI were 2.7–4.7%, 2.4–5.4%, 5.0–7.4%, and 5.4–9.2%. There were significant correlations and agreements between MPASV and RVOTSV, with the Pearson correlation coefficient ranging from 0.63 to 0.89 (P
- Published
- 2024
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- View/download PDF
35. Determination of ash content of rubber by thermogravimetric analysis
- Author
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LI Xiao-yin, SONG Jie-rui, JIA Hui-qing, YANG Fang
- Subjects
thermogravimetric analysis ,rubber ,ash content ,precision ,interlaboratory test program ,repeatability ,reproducibility ,Organic chemistry ,QD241-441 ,Chemical engineering ,TP155-156 ,Chemicals: Manufacture, use, etc. ,TP200-248 - Abstract
The ash content of rubber was determined by thermogravimetric analysis (TGA) and the effects of sample amount, sample representativeness, heating rate, combustion temperature and combustion atmosphere on the test results were studied and the repeatability and reproducibility of the method were determined. The results showed that the optimal conditions of TGA were sample mass between 10 mg and 20 mg, heating rate of 20 ℃/min or 30 ℃/min, combustion temperature for raw rubber and compounded rubber (or vulcanized rubber) of 550 ℃ and 650 ℃, respectively. The repeatability and reproducibility of TGA were all good. When ash mass fraction of 4 types of different rubbers were from 0.29% to 5.12%, the repeatability within laboratory was from 0.110% to 0.303%, and the reproducibility between laboratories was from 0.283% to 0.676%.
- Published
- 2024
- Full Text
- View/download PDF
36. Repeatability and agreement of multispectral refraction topography in school children before and after cycloplegia
- Author
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Xiaoli Xu, Wansheng Zang, Anken Wang, and Chenhao Yang
- Subjects
Agreement ,Repeatability ,Retinal peripheral refraction ,Medical technology ,R855-855.5 - Abstract
Abstract Background The purpose of this study was to evaluate the repeatability and agreement of multispectral refraction topography (MRT) in measuring retinal refraction before and after cycloplegia in children. The results of this study will provide valuable insights into the accuracy and reliability of MRT as a tool for assessing retinal refraction in pediatric patients. Methods Children aged 7 to 18 years old were recruited for this prospective research. The central and peripheral retinal refraction was measured three times using multispectral refraction topography (MRT) before and after cycloplegia. The retinal deviation value (RDV) was used to describe the average peripheral refractive error of the retina. In addition, objective refraction (OR) and subjective refraction (SR) measurements were also performed. Results A total of 60 children with a mean age of 10.50 ± 1.81 years were enrolled. Before cycloplegia, all the central and peripheral retinal refraction parameters showed good repeatability with the lowest intraclass correlation coefficient (ICC) being 0.78 in the retinal deviation value from 45° eccentricity to 53° of the retina (RDV 45–53). After cycloplegia, the repeatability of MRT was significantly enhanced (lowest ICC = 0.91 in RDV-I). The 95% limits of agreement (LoA) of the central refraction and OR ranged from − 2.1 to 1.8 D before cycloplegia, and from − 1.69 to 0.27 D after cycloplegia. The 95% LoA of the central refraction and SR ranged from − 1.57 to 0.36 D after cycloplegia. All the 95% LoA demonstrated high agreement. Conclusions The MRT shows high agreement with autorefractometry and experienced optometrist in measuring central refraction. Additionally, the MRT provides good repeatable measurements of retinal peripheral refraction before and after cycloplegia in schoolchildren.
- Published
- 2024
- Full Text
- View/download PDF
37. Time-specific convergence and divergence in individual differences in behavior: Theory, protocols and analyzes.
- Author
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Biro, Peter and Stamps, Judy
- Subjects
emergence of individual differences ,emergence of personality ,fanning in ,fanning out ,repeatability ,residual variance ,temporal reaction norms - Abstract
Over the years, theoreticians and empiricists working in a wide range of disciplines, including physiology, ethology, psychology, and behavioral ecology, have suggested a variety of reasons why individual differences in behavior might change over time, such that different individuals become more similar (convergence) or less similar (divergence) to one another. Virtually none of these investigators have suggested that convergence or divergence will continue forever, instead proposing that these patterns will be restricted to particular periods over the course of a longer study. However, to date, few empiricists have documented time-specific convergence or divergence, in part because the experimental designs and statistical methods suitable for describing these patterns are not widely known. Here, we begin by reviewing an array of influential hypotheses that predict convergence or divergence in individual differences over timescales ranging from minutes to years, and that suggest how and why such patterns are likely to change over time (e.g., divergence followed by maintenance). Then, we describe experimental designs and statistical methods that can be used to determine if (and when) individual differences converged, diverged, or were maintained at the same level at specific periods during a longitudinal study. Finally, we describe why the concepts described herein help explain the discrepancy between what theoreticians and empiricists mean when they describe the emergence of individual differences or personality, how they might be used to study situations in which convergence and divergence patterns alternate over time, and how they might be used to study time-specific changes in other attributes of behavior, including individual differences in intraindividual variability (predictability), or genotypic differences in behavior.
- Published
- 2023
38. Repeatability of diffusion kurtosis tensor parameters in muscles of the lower legs.
- Author
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Mathew, Ethan, Dortch, Richard, Damon, Bruce, Ragunathan, Sudarshan, and Quarles, C. Chad
- Abstract
Purpose: The aim of this study was to provide measurements from and investigate the repeatability of diffusion kurtosis tensor parameters in the muscles of the lower legs. Methods: Test–retest acquisition of a kurtosis tensor sequence was performed in 13 healthy volunteers. Quantitative kurtosis tensor parameters were derived, and repeatability of each parameter was evaluated by muscle group and over the whole muscle through intraclass correlation coefficient (ICC) and within‐subject coefficient of variation (wsCV). Bland–Altman analysis was also conducted. Differences in parameter values by muscle group were investigated through an analysis of variance. Results: Axial kurtosis and radial kurtosis values from the test data were 0.63 ± 0.04 and 0.70 ± 0.05, respectively. Kurtosis tensor parameters from all muscle groups and over the whole muscle had wsCV below 15%. ICC for the parameters from most muscle groups was above 85%, with the lowest ICC over the whole muscle being 88.39%. The medial gastrocnemius and extensor digitorum longus showed highest repeatability. Mean, axial, and radial diffusivity had higher wsCV despite being lower‐order terms than kurtosis. Conclusion: This study sought to examine the repeatability of diffusion kurtosis tensor–derived parameters in the legs and verify that they could potentially be used as longitudinal imaging metrics. wsCV values from test–retest data indicated high repeatability throughout all examined muscle groups. There were minimal differences in kurtosis and diffusivity parameters between muscle groups in this healthy volunteer cohort. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
39. Using high-repeatable radiomic features improves the cross-institutional generalization of prognostic model in esophageal squamous cell cancer receiving definitive chemoradiotherapy
- Author
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Jie Gong, Qifeng Wang, Jie Li, Zhi Yang, Jiang Zhang, Xinzhi Teng, Hongfei Sun, Jing Cai, and Lina Zhao
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Esophageal cancer ,Radiomics ,Repeatability ,Local recurrence-free survival ,Overall survival ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
Abstract Objectives Repeatability is crucial for ensuring the generalizability and clinical utility of radiomics-based prognostic models. This study aims to investigate the repeatability of radiomic feature (RF) and its impact on the cross-institutional generalizability of the prognostic model for predicting local recurrence-free survival (LRFS) and overall survival (OS) in esophageal squamous cell cancer (ESCC) receiving definitive (chemo) radiotherapy (dCRT). Methods Nine hundred and twelve patients from two hospitals were included as training and external validation sets, respectively. Image perturbations were applied to contrast-enhanced computed tomography to generate perturbed images. Six thousand five hundred ten RFs from different feature types, bin widths, and filters were extracted from the original and perturbed images separately to evaluate RF repeatability by intraclass correlation coefficient (ICC). The high-repeatable and low-repeatable RF groups grouped by the median ICC were further analyzed separately by feature selection and multivariate Cox proportional hazards regression model for predicting LRFS and OS. Results First-order statistical features were more repeatable than texture features (median ICC: 0.70 vs 0.42–0.62). RFs from LoG had better repeatability than that of wavelet (median ICC: 0.70–0.84 vs 0.14–0.64). Features with smaller bin widths had higher repeatability (median ICC of 8–128: 0.65–0.47). For both LRFS and OS, the performance of the models based on high- and low-repeatable RFs remained stable in the training set with similar C-index (LRFS: 0.65 vs 0.67, p = 0.958; OS: 0.64 vs 0.65, p = 0.651), while the performance of the model based on the low-repeatable group was significantly lower than that based on the high-repeatable group in the external validation set (LRFS: 0.61 vs 0.67, p = 0.013; OS: 0.56 vs 0.63, p = 0.013). Conclusions Applying high-repeatable RFs in modeling could safeguard the cross-institutional generalizability of the prognostic model in ESCC. Critical relevance statement The exploration of repeatable RFs in different diseases and different types of imaging is conducive to promoting the proper use of radiomics in clinical research. Key Points The repeatability of RFs impacts the generalizability of the radiomic model. The high-repeatable RFs safeguard the cross-institutional generalizability of the model. Smaller bin width helps improve the repeatability of RFs. Graphical Abstract
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- 2024
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40. Evaluation of repeatability and agreement of two optical biometers for intraocular lens power calculation
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Irene Martinez Alberquilla, Saga Svensson, Javier Ruiz-Alcocer, David Madrid-Costa, Alberto Dominguez-Vicent, and Abinaya Priya Venkataraman
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Repeatability ,Agreement ,IOL power calculation ,Lenstar ,Eyestar ,Medicine ,Science - Abstract
Abstract The repeatability of two biometers (Lenstar-LS900 and Eyestar-900) to measure ocular parameters and intraocular lens (IOL) power calculation, and their agreement were evaluated. 134 eyes of 134 participants were measured thrice with each biometer. Axial length (AL), anterior chamber depth (ACD), lens thickness (LT) and keratometry (K) were evaluated. The IOL power was calculated using different formulas. The repeatability limit (RLimit), the mean differences (MD) and the limits of agreement (LoA) were calculated. The RLimits for all parameters were higher with Lenstar compared to Eyestar. RLimits were lower than 0.50 D except for Barrett Universal II (0.54 D) and Haigis (0.51 D) formulas with the Lenstar. Mean differences were lower than 0.01 mm for AL, ACD and LT, and lower than 0.03 D for K. MD ranged from 0 to 0.02 D for all formulas except for Barrett and Hill. When dividing the sample into subgroups (short, normal and long eyes), the MDs were similar for the IOL power and were lower than 0.03 D, except for the Barrett and Hill formulas. Both biometers provide repeatable biometry and IOL power calculations. The LoA interval for the IOL power calculation was between 0.75 and 1.50D, which was similar among the subgroups.
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- 2024
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41. Development of a Capacitive Pressure Sensor Based on Nanoporous Anodic Aluminium Oxide
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Trishna Moni Das, Devabrata Sarmah, Sankar Moni Borah, and Sunandan Baruah
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capacitive pressure sensor ,anodic aluminium oxide (aao) ,anodization ,sensitivity ,response time ,repeatability ,Physics ,QC1-999 - Abstract
Capacitive pressure sensors make pressure sensing technology more accessible to a wider range of applications and industries, including consumer electronics, automotive, healthcare etc. However, developing a capacitive pressure sensor with brilliant performance using a lowcost technique remains a difficulty. In this work, the development of a capacitive pressure sensor based on nanoporous AAO fabricated by a two-step anodization approach which offers a promising solution for precise pressure measurement is fabricated by a two-step anodization approach. A parallel plate capacitive sensor was fabricated by placing two AAO deposited sheets are placed face to face, with the non-anodized aluminum component at the base functioning as the top and bottom electrodes. A variation in the capacitance value of the as fabricated sensor was observed over an applied pressure range (100 Pa-100 kPa). This change in capacitance can be attributed to the decrease in the distance between the two plates and the non-homogenous distribution of contact stress and strain due to the presence of nanoporous AAO structure. In this pressure range the sensor showed high sensitivity, short response time and excellent repeatability which indicates a promising future of the fabricated sensor in consumer electronics, intelligent robotics etc.
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- 2024
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42. Genetic parameters for udder conformation traits derived from Cartesian coordinates generated by robotic milking systems in North American Holstein cattle
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Gabriel C. Medeiros, Jose Bento S. Ferraz, Victor B. Pedrosa, Shi-Yi Chen, Jarrod S. Doucette, Jacquelyn P. Boerman, and Luiz F. Brito
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genetic correlation ,heritability ,milking robots ,repeatability ,udder conformation ,Dairy processing. Dairy products ,SF250.5-275 ,Dairying ,SF221-250 - Abstract
ABSTRACT: Udder conformation is directly related to milk yield, cow health, workability, and welfare. Automatic milking systems (AMS, also known as milking robots) have become popular worldwide, and the number of dairy farms adopting these systems has increased considerably over the past years. In each milking visit, AMS record the location of the 4 teats as Cartesian coordinates in an xyz plan, which can then be used to derive udder conformation traits. Because AMS generate a large amount of data for individual cows per milking visit, they can contribute to an accurate assessment of important traits such as udder conformation without the addition of human classifier errors (in subjective scoring systems). Therefore, the primary objectives of this study were to estimate genomic-based genetic parameters for udder conformation traits derived from AMS records in North American Holstein cattle and to assess the genetic correlation between the derived traits for evaluating the feasibility of multitrait genomic selection for breeding cows that are more suitable for milking in AMS. The Cartesian teat coordinates measured during each milking visit were collected by 36 milking robots in 4,480 Holstein cows from 2017 to 2021, resulting in 5,317,488 records. A total of 4,118 of these Holstein cows were also genotyped for 57,600 SNPs. Five udder conformation traits were derived: udder balance (UB, mm), udder depth (UD, mm), front teat distance (FTD, mm), rear teat distance (RTD, mm), and distance front–rear (DFR, mm). In addition, 2 traits directly related to cow productivity in the system were added to the study: daily milk yield (DY) and milk electroconductivity (EC; as an indicator of mastitis). Variance components and genetic parameters for UB, UD, FTD, RTD, DFR, DY, and EC were estimated based on repeatability animal models. The estimates of heritability (± SE) for UB, UD, FTD, RTD, DFR, DY, and EC were 0.41 ± 0.02, 0.79 ± 0.01, 0.53 ± 0.02, 0.40 ± 0.02, 0.65 ± 0.02, 0.20 ± 0.02, and 0.46 ± 0.02, respectively. The repeatability estimates (± SE) for UB, UD, FTD, RTD, and DFR were 0.82 ± 0.01, 0.93 ± 0.01, 0.87 ± 0.01, 0.83 ± 0.01, and 0.88 ± 0.01, respectively. The strongest genetic correlations were observed between FTD and RTD (0.54 ± 0.03), UD and DFR (−0.47 ± 0.03), DFR and FTD (0.32 ± 0.03), and UD and FTD (−0.31 ± 0.03). These results suggest that udder conformation traits derived from Cartesian coordinates from AMS are moderately to highly heritable. Furthermore, the moderate genetic correlations between these traits should be considered when developing selection subindexes. The most relevant genetic correlations between traits related to cow milk productivity and udder conformation traits were between UD and EC (−0.25 ± 0.03) and between DFR and DY (0.30 ± 0.04), in which both genetic correlations are favorable. These findings will contribute to the design of genomic selection schemes for improving udder conformation in North American Holstein cattle, especially in precision dairy farms.
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- 2024
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43. Repeatability and reproducibility of a new method for centration analysis via optical zone tangent points after corneal refractive surgery
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Xuejuan Wu, Jing Wu, Chuanwei Zhang, Yan Xu, Qian Chen, Qing Chen, and Kai Li
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Centration analysis ,Decentration ,Corneal refractive surgery ,Repeatability ,Reproducibility ,Ophthalmology ,RE1-994 - Abstract
Abstract Purpose To investigate the repeatability and reproducibility of a new method for centration analysis after small incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK). Methods This study comprised 29 eyes treated with SMILE and 24 with FS-LASIK. Decentrations were analyzed using tangential and pachymetry difference maps respectively. Both difference maps were generated with a Scheimpflug tomographer (Pentacam) for each eye, using preoperative and 3-month postoperative scans. Repeatability and reproducibility were evaluated by calculating the intraclass correlation coefficient (ICC), within-subject standard deviation (Sw), and coefficient of repeatability (CR). Results ICC, Sw, and CR showed good to excellent repeatability in locating the coordinates of the optical zone (OZ) center on both maps, with values ranging from 0.84 to 0.96, 0.03 to 0.13, and 0.08 to 0.36 respectively. The repeatability of the total decentration from the preoperative corneal vertex on the tangential curvature difference maps( $$d_{TC}$$ d TC ) and the pachymetry difference maps( $$d_{PC}$$ d PC ) were moderate and good, respectively. The ICC, Sw, and CR of $$d_{TC}$$ d TC were 0.63, 0.09, and 0.25, respectively. The ICC, Sw, and CR of $$d_{PC}$$ d PC were 0.77, 0.10, and 0.28, respectively. The reproducibility of the OZ center measurements was excellent for the tangential difference maps (ICC $$\ge 0.97$$ ≥ 0.97 ) and good for the pachymetry difference maps (ICC $$\ge$$ ≥ 0.86). ICC, Sw, and CR showed excellent reproducibility of $$d_{TC}$$ d TC , with values of 0.95, 0.03, and 0.08, respectively. ICC, Sw, and CR showed good reproducibility of $$d_{PC}$$ d PC , with values of 0.89, 0.06, and 0.17, respectively. Conclusion The centration analysis method used in this study showed good to excellent repeatability and reproducibility in locating the coordinates of the center of the OZ on the tangential and pachymetry difference maps.
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- 2024
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44. The effect of cycloplegia in the accuracy of autorefraction, keratometry and axial length using the Myopia Master
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Agustin Peñaranda, Oscar Torrado, Ana Márquez, António M. Baptista, and Pedro Miguel Serra
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Refractive error ,Biometry ,Repeatability ,Agreement ,Axial length ,Cycloplegia ,Ophthalmology ,RE1-994 - Abstract
Abstract Background Assessing refractive errors under cycloplegia is recommended for paediatric patients; however, this may not always be feasible. In these situations, refraction has to rely on measurements made under active accommodation which may increase measurements variability and error. Therefore, evaluating the accuracy and precision of non-cycloplegic refraction and biometric measurements is clinically relevant. The Myopia Master, a novel instrument combining autorefraction and biometry, is designed for monitoring refractive error and ocular biometry in myopia management. This study assessed its repeatability and agreement for autorefraction and biometric measurements pre- and post-cycloplegia. Methods A prospective cross-sectional study evaluated a cohort of 96 paediatric patients that underwent ophthalmologic examination. An optometrist performed two repeated measurements of autorefraction and biometry pre- and post-cycloplegia. Test-retest repeatability (TRT) was assessed as differences between consecutive measurements and agreement as differences between post- and pre-cycloplegia measurements, for spherical equivalent (SE), refractive and keratometric J0/J45 astigmatic components, mean keratometry (Km) and axial length (AL). Results Cycloplegia significantly improved the SE repeatability (TRT, pre-cyclo: 0.65 D, post-cyclo: 0.31 D). SE measurements were more repeatable in myopes and emmetropes compared to hyperopes. Keratometry (Km) repeatability did not change with cycloplegia (TRT, pre-cyclo: 0.25 D, post-cyclo:0.27 D) and AL repeatability improved marginally (TRT, pre-cyclo: 0.14 mm, post-cyclo: 0.09 mm). Regarding pre- and post-cycloplegia agreement, SE became more positive by + 0.79 D, varying with refractive error. Myopic eyes showed a mean difference of + 0.31 D, while hyperopes differed by + 1.57 D. Mean keratometry, refractive and keratometric J0/J45 and AL showed no clinically significant differences. Conclusions Refractive error measurements, using the Myopia Master were 2.5x less precise pre-cycloplegia than post-cycloplegia. Accuracy of pre-cycloplegic refractive error measurements was often larger than the clinically significant threshold (0.25 D) and was refractive error dependent. The higher precision compared to autorefraction measurements, pre- and post-cycloplegia agreement and refractive error independence of AL measurements emphasize the superiority of AL in refractive error monitoring.
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- 2024
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45. The repeatability of stride time variability, regularity, and long-range correlations.
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Slattery, Patrick, Wheat, Jon, Lizama, L. Eduardo Cofré, Gastin, Paul, Dascombe, Ben, Huynh, Minh, and Middleton, Kane
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GAIT in humans , *MECHANICAL loads , *MILITARY medicine , *STATISTICAL correlation , *STANDARD deviations - Abstract
Detrended fluctuation analysis (DFA) and sample entropy (SE) measure the long-term correlations and regularity of gait patterns, respectively, having previously been used to identify participants at risk of falling, previous history of injury, or patients with motor diseases. Since these measures are more sensitive to gait impairment than linear measures (e.g., the standard deviation [SD] of stride time), they can be potentially used in military medicine to identify soldiers at risk of injury. However, clinometric properties are yet to be established. What is the repeatability of DFA, SE, and traditional linear measures of stride time variability (SD and coefficient of variation [CV]) under various load and speed constraints? Fourteen Australian Army trainee soldiers (age: 25.6 ± 5.9 y, height: 1.74 ± 0.08 m, body mass: 77.2 ± 15.1 kg, service: 1.5 ± 1.8 y) attended three sessions over two weeks, completing four 12-minute walking trials on an instrumented treadmill in each session. Participants walked with a combination of 0 kg or 23 kg loads at a self-selected or 5.5 km/h speed. Heel contacts from the right foot were identified using treadmill-embedded force plates. From 512 stride time intervals, linear (SD and CV), and non-linear (DFA and SE) measures were obtained. To assess the between-session repeatability, intraclass correlations (ICC 2,1) were employed. There was poor-to-moderate repeatability for the SD (ICC: 0.357–0.545) and CV (ICC: 0.371–0.529). DFA showed poor-to-moderate repeatability (ICC: 0.013–0.504), while SE had poor repeatability (ICC: 0.133–0.226). Previous studies have shown that differences of > 0.19 in DFA and > 0.66 in SE can differentiate between healthy and pathological gait. These values are greater than this study's reported standard error of measurement, indicating that clinically meaningful changes may still be detectable despite low repeatability. • The repeatability of stride time measures during loaded marching were established • Linear and non-linear measures demonstrated poor-to-moderate repeatability • Non-linear measures had a variation of less than 10 % between sessions • Meaningful changes in stride time measures can be detected during marching [ABSTRACT FROM AUTHOR]
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- 2024
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46. Using high-repeatable radiomic features improves the cross-institutional generalization of prognostic model in esophageal squamous cell cancer receiving definitive chemoradiotherapy.
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Gong, Jie, Wang, Qifeng, Li, Jie, Yang, Zhi, Zhang, Jiang, Teng, Xinzhi, Sun, Hongfei, Cai, Jing, and Zhao, Lina
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SQUAMOUS cell carcinoma , *PROPORTIONAL hazards models , *INTRACLASS correlation , *COMPUTED tomography , *ESOPHAGEAL cancer , *PROGNOSTIC models - Abstract
Objectives: Repeatability is crucial for ensuring the generalizability and clinical utility of radiomics-based prognostic models. This study aims to investigate the repeatability of radiomic feature (RF) and its impact on the cross-institutional generalizability of the prognostic model for predicting local recurrence-free survival (LRFS) and overall survival (OS) in esophageal squamous cell cancer (ESCC) receiving definitive (chemo) radiotherapy (dCRT). Methods: Nine hundred and twelve patients from two hospitals were included as training and external validation sets, respectively. Image perturbations were applied to contrast-enhanced computed tomography to generate perturbed images. Six thousand five hundred ten RFs from different feature types, bin widths, and filters were extracted from the original and perturbed images separately to evaluate RF repeatability by intraclass correlation coefficient (ICC). The high-repeatable and low-repeatable RF groups grouped by the median ICC were further analyzed separately by feature selection and multivariate Cox proportional hazards regression model for predicting LRFS and OS. Results: First-order statistical features were more repeatable than texture features (median ICC: 0.70 vs 0.42–0.62). RFs from LoG had better repeatability than that of wavelet (median ICC: 0.70–0.84 vs 0.14–0.64). Features with smaller bin widths had higher repeatability (median ICC of 8–128: 0.65–0.47). For both LRFS and OS, the performance of the models based on high- and low-repeatable RFs remained stable in the training set with similar C-index (LRFS: 0.65 vs 0.67, p = 0.958; OS: 0.64 vs 0.65, p = 0.651), while the performance of the model based on the low-repeatable group was significantly lower than that based on the high-repeatable group in the external validation set (LRFS: 0.61 vs 0.67, p = 0.013; OS: 0.56 vs 0.63, p = 0.013). Conclusions: Applying high-repeatable RFs in modeling could safeguard the cross-institutional generalizability of the prognostic model in ESCC. Critical relevance statement: The exploration of repeatable RFs in different diseases and different types of imaging is conducive to promoting the proper use of radiomics in clinical research. Key Points: The repeatability of RFs impacts the generalizability of the radiomic model. The high-repeatable RFs safeguard the cross-institutional generalizability of the model. Smaller bin width helps improve the repeatability of RFs. [ABSTRACT FROM AUTHOR]
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- 2024
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47. Development of an equine endometrial histology scoring system to complement the Kenney–Doig scale.
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Martínez‐Bartolomé, I., Masot, J., and Serres, C.
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PATHOLOGISTS , *MARES , *BIOPSY , *INFLAMMATION , *HISTOLOGY - Abstract
Kenney–Doig scale is considered the international standard method for classifying uterine biopsies in mares; however, its objectivity has been questioned by various studies. In the present study, we analysed the degree of agreement between two pathologists when assessing the same set of 201 uterine biopsies, obtaining a slight to moderate level of agreement (κ =.34/κw =.57). Subsequently, we developed a numerical scale based on the evaluation of histological parameters, including inflammation, fibrosis, glandular density and lymphatic lacunae. Partial scores were summed to obtain a fifth parameter called Summation. The correlation between both scales was demonstrated (p <.0001), and their combined use resulted in a notable increase in the degree of agreement between the two pathologists (κ =.53/κw =.67). [ABSTRACT FROM AUTHOR]
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- 2024
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48. Daily variation and repeatability of advertisement calls in an austral temperate forest frog under controlled conditions.
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Moreno‐Gómez, Felipe N., Bidart‐Enríquez, Gabriel, Cossio‐Rodríguez, Romina, Muñoz, Matías I., Quispe, Maricel, and Penna, Mario
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TEMPERATE forests , *SEXUAL selection , *STATISTICAL reliability , *SOCIAL history , *FROGS - Abstract
Estimating repeatability allows a first approximation that may indicate a potential response to selection of sexual traits. Acoustic sexual signals comprise spectral and temporal variables, where the former generally have lower intra‐individual variation and higher repeatability values. Studies of repeatability in anurans have been conducted mainly in natural conditions, but the stability of laboratory settings allows extended recording intervals, favoring measurement accuracy. We conducted a study of variation and repeatability of the calls of males of Batrachyla taeniata, a frog from the South American temperate forest to evaluate under homogeneous environmental and social conditions: (i) the extent of variation in acoustic properties of calls within and among days, (ii) the extent of temporal variation in the repeatability of call properties, and (iii) differences in repeatability among call variables. Variation of acoustic properties differed within and across days of recording, call rate generally increased within and throughout days, suggesting sensitization processes. Call duration decreased during these time spans, yielding constant calling effort. In contrast, the dominant frequency decreased within days but increased across days. Overall repeatability differs significantly among variables: dominant frequency, call rate, and call duration having the highest, intermediate, and lowest values, respectively. The high repeatability of call rate relative to call duration contrasts with an opposing general tendency in previous studies in anurans. The repeatability of the three variables analyzed increases within days, and the repeatability of call rate also increases throughout days, highlighting the relevance of this variable for individual identity over different time ranges. [ABSTRACT FROM AUTHOR]
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- 2024
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49. 变压器油色谱分析检测能力评价方法.
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石荣雪, 刘克成, 郁金星, 周慧波, 韩鹤松, and 刘思琦
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Four kinds of methods were selected to evaluate the chromatography detection results of gas chromatograph from each company, then the application results of each evaluation methods in the evaluation of transformer oil chromatographic detection capability were researched・ The result showed that the iterative robust statistical method combined with the repeatability requirements in GB/T 17623--2017 has higher reliability・ The Z-score classical statistical method is stricter than the Z-score robust statistical method, but both of them have the risk of over deleted・ It is suggested to set the "dissatisfied, evaluation criteria for both of them as IZI m3 and apply them in combination w让h the repeatability requirement in GB/T 17623--2017. The iterative robust statistical method has a high agreement with the boxplot outlier removal results in the Z-score classical statistical method・ Besides, only one gas detection parameter of one instrument is removed by the boxplot outlier but not by the 让erative robust statistical method, and other removal results are all included in the removal results of the iterative robust statistical method・ The result showed that the iterative robust statistical method has high credibility in removing outliers, and the boxplot can be used directly to remove outliers for evaluation when the Z-score classical statistical method is applied. [ABSTRACT FROM AUTHOR]
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- 2024
50. Validity and reliability of trunk and lower-limb kinematics during squatting, hopping, jumping and side-stepping using OpenCap markerless motion capture application.
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Lima, Yuri Lopes, Collings, Tyler, Hall, Michelle, Bourne, Matthew N., and Diamond, Laura E.
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LEG physiology , *TORSO physiology , *T-test (Statistics) , *THREE-dimensional imaging , *RESEARCH funding , *KINEMATICS , *PARAMETERS (Statistics) , *DESCRIPTIVE statistics , *ODDS ratio , *MATHEMATICAL statistics , *DIGITAL video , *STATISTICAL reliability , *INTRACLASS correlation , *BODY movement , *JUMPING , *COMPARATIVE studies , *ATHLETIC ability , *DATA analysis software , *CONFIDENCE intervals , *MOTION capture (Human mechanics) , *VIDEO recording ,RESEARCH evaluation - Abstract
OpenCap is a web-based markerless motion capture platform that estimates 3D kinematics from videos recorded from at least two iOS devices. This study aimed to determine the concurrent validity and inter-session reliability of OpenCap for measuring trunk and lower-limb kinematics during squatting, hopping, countermovement jumping, and cutting. Nineteen participants (10 males, 9 females; age 27.7 ± 4.1 years) were included. Countermovement jump, single-leg triple vertical hop, single-leg squat, sidestep cutting and side hop tasks were assessed. For validity, OpenCap was compared to a marker-based motion capture system using root-mean-square error. Test–retest reliability of OpenCap was determined using intraclass correlations and minimum detectable change (MDC) from two testing sessions. The squat had the lowest RMSE across joint angles (mean = 7.0°, range = 2.9° to 13.6°). For peak angles, the countermovement jump (jump phase) (ICC = 0.62–0.93) and the squat (ICC = 0.60–0.92) had the best reliability across all joints. For initial contact, the side hop had the best inter-session reliability (ICC = 0.70–0.94) across all joint angles. As such, OpenCap validity and reliability are joint and task specific. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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