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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.

We report an efficient sample preparation method (freezing) for onsite fat and meat analysis via a specially designed thermoelectric cooling and temperature-controlling system. This investigation also focused on the effect of phase change on the sensitivity and reproducibility of LIBS emission signals and plasma parameters. The plasma emissions of animal fats (lard) were recorded when the sample was frozen (−2 °C), fluid (15 °C), and in a liquid state (37 °C) with a thermoelectric cooling system. At each temperature, the plasma emissions were acquired at laser pulse energy from 50 to 300 mJ and detector gate delay (DGD) from 0.5 to 5 μs. With increasing sample temperature, the DGD, where the optical emission intensity reached a maximum, decreased. At a laser pulse energy of 200 mJ and a sample temperature of −2 °C, the emission signals increased fourfold, the signal-to-noise ratio (SNR) improved tenfold, and the self-absorption in the emission lines decreased significantly. The repeatability of the emission signals and plasma parameters of frozen and liquid fat samples was determined using the relative standard deviation (RSD) of Se I (473.08 nm) and K I (766.48 nm) emission lines. The RSDs of the emission signals improved from 40 to 18 % and 37 to 16 %, whereas the shot-to-shot RSDs of the electron temperature and electron number density get improved from 11 to 6 % and 12 to 6.8 %, respectively.

Feed utilization efficiency is an important trait in dairy production playing a significant role in reducing feed costs and lowering methane emission. One of the metrics used to measure feed efficiency in dairy cows is residual feed intake (RFI). This metric requires routine measurement of feed intake. Since there is a positive high correlation between heat production and carbon dioxide (CO2) production on the one hand and heat production and efficiency on the other hand, residual carbon dioxide (RCO2) might be a useful metric to improve feed efficiency. The objectives of this study were to model the trajectories of RCO2 and RFI as well as to estimate their repeatabilities and correlations at different stages of lactation. Daily CO2 output and feed intake were recorded from 46 primiparous Nordic Red dairy cows using two Greenfeed Emissions Monitoring™ systems from 2 to 305 days in milk (DIM). Edited data comprised 5 995 daily averages. To calculate predicted values of CO2 and DM intake (DMI), prediction models were developed by fitting multiple regression models to observations. Subsequently, RCO2 and RFI were calculated by subtracting predicted values of CO2 and DMI from their corresponding actual observations. A random regression bivariate model was fitted to estimate repeatabilities and animal correlations within lactation at different DIMs between RCO2 and RFI traits. The model fitted included fixed effects of year-month of recording, lactation month, fixed regressions as well as random regressions for the animal effect. The residual variance was considered to be heterogeneous. Repeatabilities and animal correlations of RCO2 and RFI between selected DIM (for every 30 DIM i.e., 6, 36,…, 246 and 276) were calculated. Repeatability of RCO2 was high at the beginning of lactation (0.72 at DIM 6) and decreased around the peak of milk production (0.27 at DIM 96) and again increased gradually toward the end of lactation. Similarly, RFI also had high repeatability at the beginning (0.86 at DIM 6); however, it decreased in mid-lactation (0.37 at DIM 156) and then increased toward the end of lactation. Animal correlations between RCO2 and RFI were moderate to high on the same DIM and ranged from 0.37 to 0.88. Overall, we found that animals with higher CO2 production than expected also consume more DMI than expected, but the moderate correlation between RCO2 and RFI found in this study calls for more research to assess the potential of RCO2 to become a new feed efficiency metric.

ABSTRACT: In this study a 3-dimensional (3D) camera system was set up to measure individual feed intake of dairy cows in a commercial in-house setting. The system was developed to identify the cows while eating, predict body weight based on the curvature of the back of the cow, and quantify the amount of feed eaten by the cow at each visit of eating. The identification of the cow was based on recognizing the patterns, colors, and curvatures of the back from a reference database obtained in a corridor after milking, where images were taken of all cows with a simultaneous reading of the electronic ear tag. Body weight is predicted using the curvatures of the back of the cow. Feed intake is quantified as the difference in surface of the feed a cow can reach before and after a visit is initiated. This estimate is in liters but converted to kilograms, using the density of the feed in the specific herd. A total of 9,142 cows were measured in 19 herds across 3 breeds: Jersey (2,513 cows), Red Dairy Cattle (2,813 cows), and Holstein (3,816 cows). Mean daily feed intake was higher for Red Dairy Cattle (61.72 kg) and Holstein (64.59 kg) than for Jersey (55.74 kg). Repeatability estimates for daily feed intake as a weekly average was 0.62, 0.65, and 0.63 for Jersey, Red Dairy, and Holstein cattle, respectively. Mean body weight was higher for Red Dairy (647.9 kg) and Holstein (683.8 kg) than for Jersey (469.6 kg). Repeatability estimates for body weight as a weekly average was 0.83, 0.85, and 0.88 for Jersey, Red Dairy, and Holstein, respectively. The perspectives in having such records available is huge both for the farmer and for the dairy industry. The records can both be used for improving management in farms on an individual cow level and herd level, but also for genetic evaluation and selection as well as testing feeding regimens. Feed intake can be measured on an individual level using a 3D camera system.

Spherical silver nanoparticles (AgNps) show high scientific, economic, and biotechnological interest related to their photonic properties associated to the fascinating plasmonic absorption and antimicrobial activity, however, their synthesis using wet-chemical methods remains a challenge, in terms of control, repeatability, and reproducibility. Herein, we investigated two adapted strategies to produce water-suspended spheroidal and homogeneous AgNps by using sodium citrate (CT) and ascorbic acid (AA) as stabilizing and reducing agents, respectively. We also show the impact of experimental parameters such as reactional time, temperature, and precursor concentration, as well as their order/method of addition on the morphology and optical properties of AgNps that were intrinsically correlated through extinction spectra and transmission electron microscopy (TEM), additionally the activity of prepared AgNPs colloidal suspensions were tested against Staphylococcus aureus bacterium. The most controllable synthesis condition was achieved by methodology in which the silver precursor is added dropwise (one drop per second) to a solution at 70 °C containing CT and AA keeping the stirring for 20 min. The proposed methodology presented a high repeatability of the syntheses generating AgNps with regular size and shape (between 22 and 30 nm), being stable in water up to one year with slight changes in its plasmonic and morphological properties. A scale-up trial was also performed and the dropwise methodology allowed the obtention of spheroidal-AgNps suspensions five times more concentrated with the same morphological and optical control, which saves time and energy in the synthesis process. The AgNPs demonstrated a good antibacterial potential when the samples are freshly prepared, losing their activity as the samples age.

The reliability of the result significantly affects the use of the Coefficient of Variation (within the test variation), which reflects the variability of the concrete properties rather than the standard deviation. For the estimation of reliability and precision, comprehensive statistical analysis (within test variation) is conducted on 534 test samples using a rebound hammer. Different standards, like BIS, EN, ACI, and ASTM, are used in this study to compare the test results. Empirical research revealed that there are contradictions in literature as well as the standards used in many countries. The present paper focuses on detailed investigations of uncertainty measurements of the surface hardness test by statistical parameters (range of rebound index, standard deviation, and Coefficient of Variation). The unbiased estimate of the variability parameters from the published results has been verified concerning to the European standard. Concrete parameters namely cement type, water to cement ratio, compaction deficiency, curing condition, and elevated temperature have an impact on the output of the rebound hardness in terms of the variability of the compressive strength. Based on the results, the authors are willing to propose amendments to the Indian code graciously in compliance with the variability of the rebound hammer.

Sagittal knee laxity is often quantified using arthrometers. Adding rotational laxity and compliance measurements is relatively new and could bring new information for anterior cruciate ligament (ACL) injury diagnosis. The DYNEELAX® is a new knee arthrometer able to evaluate simultaneously tibial translation and rotation. The purpose is to assess the sensitivity, reproducibility and repeatability of the DYNEELAX® with a prototype leg to provide accurate instructions before using it in clinical practice. Sensitivity is studied by varying 7 parameters (positioning and sensors), and reproducibility by repeating measurement series with a group of two experienced operators and a group of two non-experienced operators. Repeatability is assessed throughout the study. The results showed that DYNEELAX® is poorly sensitive to the angle and the position of the displacement sensor, and the angle of the rotation sensor. It is a bit sensitive to positioning of patella and ankle supports. It is very sensitive to the tightening of the patella and ankle supports. It exists a significant difference only between groups (p ​ ​0.215), or between the two non-experienced operators (p ​> ​0.229). Variation coefficients for intra-series are on average inferior to 5% for translation and rotation tests. Then, the DYNEELAX® presented encouraging results with a good accuracy and a good reliability but operators must be careful about positioning.

Quantitative Susceptibility Mapping (QSM) is a recent MRI-technique able to quantify the bulk magnetic susceptibility of myelin, iron, and calcium in the brain. Its variability across different acquisition parameters has prompted the need for standardisation across multiple centres and MRI vendors. However, a high level of agreement between repeated imaging acquisitions is equally important. With this study we aimed to assess the inter-scan repeatability of an optimised multi-echo GRE sequence in 28 healthy volunteers. We extracted and compared the susceptibility measures from the scan and rescan acquisitions across 7 bilateral brain regions (i.e., 14 regions of interest (ROIs)) relevant for neurodegeneration. Repeatability was first assessed while reconstructing QSM with a fixed number of echo times (i.e., 8). Excellent inter-scan repeatability was found for putamen, globus pallidus and caudate nucleus, while good performance characterised the remaining structures. An increased variability was instead noted for small ROIs like red nucleus and substantia nigra. Secondly, we assessed the impact exerted on repeatability by the number of echoes used to derive QSM maps. Results were impacted by this parameter, especially in smaller regions. Larger brain structures, on the other hand, showed more consistent performance. Nevertheless, with either 8 or 7 echoes we managed to obtain good inter-scan repeatability on almost all ROIs. These findings indicate that the designed acquisition/reconstruction protocol has wide applicability, particularly in clinical or research settings involving longitudinal acquisitions (e.g. rehabilitation studies).

Background: The effort-independent tidal breathing test used by oscillometry presents a viable alternative for following up patients whose condition is stable while they are receiving biologic therapy. Objective: We aimed to determine intrasession and intersession repeatability values for airwave oscillometry (AOS) and spirometry in patients who were already taking benralizumab. Methods: In all, 21 patients with severe eosinophilic asthma attended the Scottish Centre for Respiratory Research as part of a clinical trial (EudraCT identification number 2019-003763-22). Paired AOS and spirometry values were obtained at 3 separate visits (baseline and days 28 and 56) with no change in asthma therapy. Results: Intrasession agreement between repeated measurements for AOS and spirometry was excellent (intraclass correlation coefficient ≥ 0.90) at all 3 visits. Intersession agreement was also excellent (intraclass correlation coefficient ≥ 0.80). Conclusion: In this study we report medium-term intrasession and intersession repeatability values for airwave oscillometry and spirometry in a cohort of severely asthmatic patients receiving benralizumab therapy. Oscillometry can be used to follow up patients with asthma who are taking biologics.

Photoacoustic mesoscopy visualises vascular architecture at high-resolution up to ~3 mm depth. Despite promise in preclinical and clinical imaging studies, with applications in oncology and dermatology, the accuracy and precision of photoacoustic mesoscopy is not well established. Here, we evaluate a commercial photoacoustic mesoscopy system for imaging vascular structures. Typical artefact types are first highlighted and limitations due to non-isotropic illumination and detection are evaluated with respect to rotation, angularity, and depth of the target. Then, using tailored phantoms and mouse models, we investigate system precision, showing coefficients of variation (COV) between repeated scans [short term (1 h): COV= 1.2%; long term (25 days): COV= 9.6%], from target repositioning (without: COV=1.2%, with: COV=4.1%), or from varying in vivo user experience (experienced: COV=15.9%, unexperienced: COV=20.2%). Our findings show robustness of the technique, but also underscore general challenges of limited-view photoacoustic systems in accurately imaging vessel-like structures, thereby guiding users when interpreting biologically-relevant information.

Purpose: To assess the intrasession repeatability of macular OCT angiography (OCTA) parameters in Alzheimer's disease (AD), mild cognitive impairment (MCI), Parkinson's disease (PD), and normal cognition (NC). Design: Cross sectional study. Subjects: Patients with a clinical diagnosis of AD, PD, MCI, or NC were imaged. Images with poor quality and of those with diabetes mellitus, glaucoma, or vitreoretinal disease were excluded from analysis. Methods, Intervention or Testing: All participants were imaged using the Zeiss Cirrus HD-5000 with AngioPlex (Carl Zeiss Meditec, Software Version 11.0.0.29946) and repeat OCTA images were obtained for both eyes. Perfusion density (PFD), vessel density (VD), and Foveal avascular zone (FAZ) area were measured from 3 × 3 mm and 6 × 6 mm OCTA images centered on the fovea using an ETDRS grid overlay. Main Outcome Measures: Intraclass correlation coefficients were used to quantify repeatability of PFD, VD, and FAZ area measurements obtained from imaging. Results: 3 × 3 mm scans of 22 AD, 40 MCI, 21 PD, and 26 NC participants and 6 × 6 mm scans of 29 AD, 44 MCI, 29 PD, and 30 NC participants were analyzed. Repeatability values ranged from 0.64 (0.49–0.82) for 6 × 6 mm PFD in AD participants to 0.87 (0.67–0.92) for 3 × 3 mm PFD in AD participants. No significant differences were observed in repeatability between NC participants and those with neurodegenerative disease. Conclusions: Overall, similar OCTA repeatability was observed between NC participants and those with neurodegeneration. Regardless of diagnostic group, macular OCTA metrics demonstrated moderate to good repeatability. Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article.

Background and purpose: Glioblastoma (GBM) patients have a dismal prognosis. Tumours typically recur within months of surgical resection and post-operative chemoradiation. Multiparametric magnetic resonance imaging (mpMRI) biomarkers promise to improve GBM outcomes by identifying likely regions of infiltrative tumour in tumour probability (TP) maps. These regions could be treated with escalated dose via dose-painting radiotherapy to achieve higher rates of tumour control. Crucial to the technical validation of dose-painting using imaging biomarkers is the repeatability of the derived dose prescriptions. Here, we quantify repeatability of dose-painting prescriptions derived from mpMRI. Materials and methods: TP maps were calculated with a clinically validated model that linearly combined apparent diffusion coefficient (ADC) and relative cerebral blood volume (rBV) or ADC and relative cerebral blood flow (rBF) data. Maps were developed for 11 GBM patients who received two mpMRI scans separated by a short interval prior to chemoradiation treatment. A linear dose mapping function was applied to obtain dose-painting prescription (DP) maps for each session. Voxel-wise and group-wise repeatability metrics were calculated for parametric, TP and DP maps within radiotherapy margins. Results: DP maps derived from mpMRI were repeatable between imaging sessions (ICC > 0.85). ADC maps showed higher repeatability than rBV and rBF maps (Wilcoxon test, p = 0.001). TP maps obtained from the combination of ADC and rBF were the most stable (median ICC: 0.89). Conclusions: Dose-painting prescriptions derived from a mpMRI model of tumour infiltration have a good level of repeatability and can be used to generate reliable dose-painting plans for GBM patients.

There exists a variety of specialized fire dynamics routines, zone fire models, and field fire models. Many of these heuristics and correlations rely on experimental data from fires fueled by gas burners or liquid pool fires and have had minimal, if any, validation against data from fires with solid, more complex fuels, such as upholstered furniture. One hundred and twenty fire experiments were conducted inside a compartment that contained a single ventilation opening in the form of a doorway that was either open or closed for the entirety of each experiment. The fires were fueled by natural gas burners and upholstered furniture items. The compartment was instrumented throughout with thermocouples, oxygen sampling probes, heat flux gauges (total and radiative), pressure transducers, and bi-directional probes. Additionally, heat release rate data were collected during open door experiments with fires larger than 100 kW. This experimental series was designed to better quantify the repeatability of and differences between natural gas burner and upholstered furniture fuels and to provide new validation cases for the fire modeling community.

Purpose: To evaluate the repeatability and agreement in dry eye measurements using Oculus Keratograph 5M (K5M) and SBM Sistemi IDRA (IDRA)., Methods: A total of 108 participants were enrolled and 108 eyes were evaluated. Tear meniscus height (TMH) and first and average non-invasive break-up time (NIBUT) were measured using the K5M and IDRA (order randomly assigned). TMH was measured using the built-in caliper tool while NIBUT was computed by the automatic algorithm of the instruments., Results: The Bland Altman plots analysis showed a good agreement between the two instruments for TMH (95 % Limits of Agreement (LoA), -0.17 to 0.16), but not the first NIBUT (95 % LoA, -8.13 to 14.79) and average NIBUT (95 % LoA, -7.89 to 10.32). The values of the first and average NIBUT measured using IDRA were significantly shorter than in K5M (difference = median (IQR) -2.75 (-6.48- -0.28)s, p < 0.001 and difference = median (IQR) -1.65 (-3.97-1.89)s, p = 0.008 respectively). The TMH (p = 0.037) and NIBUT average (p = 0.033) measured by K5M, as well as the TMH (p = 0.040) measured by IDRA, exhibited unstable measurements across the three measurement times. The remaining parameters exhibited stability with three repeated measurements., Conclusion: The NIBUT measurements are not interchangeable between IDRA and K5M, while the TMH was little difference between the two instruments. It is important to exercise caution when using different ocular surface analyzers to minimize errors in comparing multiple measurements., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Purpose: To examine intrasession repeatability and interobserver reproducibility of tear meniscus height (TMH) and non-invasive tear breakup time (NIBUT) measurements provided by ICP Tearscope, and their agreement with Keratograph 5 M measurements in persons with and without dry eye., Methods: Participants were 48 individuals with dry eye disease (DED) and 44 healthy controls. To determine intrasession repeatability, two consecutive TMH and NIBUT measurements were carried out by a single experienced examiner using ICP Tearscope. For interobserver reproducibility, a second masked investigator measured TMH and NIBUT on the first image and video captured by the examiner. Keratograph 5 M measurements of both variables were carried out by the same examiner. Repeatability and reproducibility were evaluated through within-subject standard deviation (Sw), coefficient of variation (CoV), intraclass correlation coefficient (ICC) and Bland-Altman plots (bias and limits of agreement (LoA))., Results: The TMH measurement with ICP Tearscope showed both, a moderate intrasession repeatability (Sw = 0.045, CoV < 19.82 %, ICC > 0.684) and interobserver reproducibility (Sw = 0.032, CoV < 14.09 %, ICC > 0.926). The NIBUT measurement showed worse intrasession repeatability in the DED group (CoV = 27.53 %) than in the Control group (CoV = 13.31 %). Even though similar Sw, LoA and ICC values were observed in both groups (Sw = 2.55 s and 2.34 s; LoA = -6.60 to 5.18 s and -4.82 to 6.51 s, Control and DED respectively, ICCs > 0.95). Interobserver reproducibility indicated a moderate amount of variability with CoV ≤ 15.01 % recorded in both groups. Agreement between the two devices was poor. Limits of agreement were not clinically acceptable for TMH (LoA = -0.19 to 0.14 mm and -0.16 to 0.13 mm, Control and DED, respectively) and for NIBUT (LoA = -12.74 to 14.08 s and -12.19 to 12.87 s, Control and DED, respectively)., Conclusions: ICP Tearscope provides TMH and NIBUT measurements that show weak repeatability and moderate interobserver reproducibility. This device is not interchangeable with the Keratograph 5 M., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Hot smoke test is a key method for fire studies in metro systems. But most hot smoke test scenarios are conducted only once, which ignores the experiment uncertainties and errors. To quantify the uncertainty and repeatability of hot smoke tests in subway stations, seven experiments are repeated on a station platform. 120 thermistors are deployed among the platform to acquire the temperature curves in the experimental area. The concept of statistical analysis and functional analysis is adopted to study the error and turbulence caused by random effects. The results indicate that: (1) According to the fluctuation properties, the experiment area is divided into fire plume area and ceiling jet area. The data uncertainty of the fire plume area is significantly higher than the ceiling jet area. (2) The repeatability of temperature data in the fire plume area is poor. The difference between single experiment curve and average curve might reach 23%–24%. (3) The repeatability of the data in the ceiling jet area is much better with a deviation smaller than 7.8%. The validated experiment data presented in this work could be used for simulation model verification. The repeatability analysis method presented is applicable for other fire studies.

AmpC β-lactamase genes are clinically important because they often confer resistance to most β-lactams other than 4th-generation cephalosporins and carbapenems. However, traditional and existing detection methods are expensive, labor-intensive and range-limited. We established an efficient multiplex PCR method to simultaneously identify six families of ampC β-lactamase genes, ACC, EBC, CIT, DHA, MOX and FOX, and evaluated the sensitivity and specificity of this assay. The multiplex method could accurately identify ACC, EBC, CIT, DHA, MOX and FOX variants among a total of 175 ampC β-lactamase genes. The minimum concentration of genomic DNA that could be detected was 1.0×103 copies/μL. We subsequently used this method to analyze 2 Salmonella spp. with carrying CMY-2 and DHA-1, and 167 Enterobacteriaceae isolates in blinded PCR testing. Positive isolates produced bright bands that corresponded with their genotype. Results were in concordance with those of the traditional method but showed increased sensitivity and accuracy. This indicates that the newly developed multiplex PCR system could be used as a diagnostic tool to accurately distinguish the six families of ampC β-lactamase genes with high efficiency, wide range, easy operation and good discrimination.

MR fingerprinting (MRF) is a promising method for quantitative characterization of tissues. Often, voxel-wise measurements are made, assuming a single tissue-type per voxel. Alternatively, the Sparsity Promoting Iterative Joint Non-negative least squares Multi-Component MRF method (SPIJN-MRF) facilitates tissue parameter estimation for identified components as well as partial volume segmentations. The aim of this paper was to evaluate the accuracy and repeatability of the SPIJN-MRF parameter estimations and partial volume segmentations. This was done (1) through numerical simulations based on the BrainWeb phantoms and (2) using in vivo acquired MRF data from 5 subjects that were scanned on the same week-day for 8 consecutive weeks. The partial volume segmentations of the SPIJN-MRF method were compared to those obtained by two conventional methods: SPM12 and FSL. SPIJN-MRF showed higher accuracy in simulations in comparison to FSL- and SPM12-based segmentations: Fuzzy Tanimoto Coefficients (FTC) comparing these segmentations and Brainweb references were higher than 0.95 for SPIJN-MRF in all the tissues and between 0.6 and 0.7 for SPM12 and FSL in white and gray matter and between 0.5 and 0.6 in CSF. For the in vivo MRF data, the estimated relaxation times were in line with literature and minimal variation was observed. Furthermore, the coefficient of variation (CoV) for estimated tissue volumes with SPIJN-MRF were 10.5% for the myelin water, 6.0% for the white matter, 5.6% for the gray matter, 4.6% for the CSF and 1.1% for the total brain volume. CoVs for CSF and total brain volume measured on the scanned data for SPIJN-MRF were in line with those obtained with SPM12 and FSL. The CoVs for white and gray matter volumes were distinctively higher for SPIJN-MRF than those measured with SPM12 and FSL. In conclusion, the use of SPIJN-MRF provides accurate and precise tissue relaxation parameter estimations taking into account intrinsic partial volume effects. It facilitates obtaining tissue fraction maps of prevalent tissues including myelin water which can be relevant for evaluating diseases affecting the white matter.

Abstract Objective: To determine the test‐retest repeatability of a self‐completed survey with items capturing skin cancer risk factors. Methods: We invited 238 randomly selected participants of the QSkin II cohort to complete the baseline survey a second time. Responses were compared using kappa statistics and intraclass correlation coefficients to quantify agreement for categorical and continuous variables, respectively. We compared the performance of key items with that observed in an earlier repeatability study using the same survey instrument in an independent cohort. Results: Measures of phenotypic characteristics had moderate to almost‐perfect test‐retest repeatability (e.g. eye colour weighted kappa (κw) = 0.87, 95% confidence interval [CI]: 0.81, 0.92). Items measuring sun exposure showed lower agreement (κw range 0.36‐0.54) compared with phenotypic characteristics (κw range 0.59‐0.87). Items relating to treatment of skin cancers demonstrated almost‐perfect test‐retest repeatability (e.g. excisions for skin cancers κw 0.85, 95%CI: 0.80, 0.89). In aggregate, the repeatability of key items was very similar across the two independent repeatability samples. Conclusion: Fair to almost‐perfect repeatability for self‐reported skin cancer risk factors was robust across independent and temporally distant cohorts. Implications for public health: These self‐assessed risk factors for skin cancer are repeatable and suitable for use in clinical practice and research.

Background and Purpose: Although quantitative image biomarkers (radiomics) show promising value for cancer diagnosis, prognosis, and treatment assessment, these biomarkers still lack reproducibility. In this systematic review, we aimed to assess the progress in radiomics reproducibility and repeatability in the recent years. Methods and materials: Four hundred fifty-one abstracts were retrieved according to our search pattern criteria, with the publication dates ranging from 2017/05/01 to 2020/12/01. Each abstract including the keywords was independently screened by four observers. Forty-two full-text articles were selected for further analysis. Patient population data, radiomic feature classes, feature extraction software, image preprocessing, and reproducibility results were extracted from each article. To support the community with a standardized reporting strategy, we propose a specific reporting checklist to evaluate the feasibility to reproduce each study. Results: Many studies continue to under-report essential reproducibility information: all but one clinical and all but two phantom studies missed to report at least one important item reporting image acquisition. The studies included in this review indicate that all radiomic features are sensitive to image acquisition, reconstruction, tumor segmentation, and interpolation. However, the amount of sensitivity is feature dependent, for instance, textural features were, in general, less robust than statistical features. Conclusions: Radiomics repeatability, reproducibility, and reporting quality can substantially be improved regarding feature extraction software and settings, image preprocessing and acquisition, cutoff values for stable feature selection. Our proposed radiomics reporting checklist can serve to simplify and improve the reporting and, eventually, guarantee the possibility to fully replicate and validate radiomic studies.

Quantitative imaging biomarkers (QIBs) can be defined as objective measures that are sensitive and specific to changes in tissue physiology. Provided the acquired QIBs are not affected by scanner changes, they could play an important role in disease diagnosis, prognosis, management, and treatment monitoring. The precision of selected QIBs was assessed from data collected on a 3-T scanner in four healthy participants over a 5-year period. Inevitable scanner changes and acquisition protocol revisions occurred during this time. Standard and custom processing pipelines were used to calculate regional brain volume, cortical thickness, T2, T2*, quantitative susceptibility, cerebral blood flow, axial, radial and mean diffusivity, peak width of skeletonized mean diffusivity, and fractional anisotropy from the acquired images. Coefficient of variation (CoV) and intra-class correlation (ICC) indices were determined in the short-term (i.e., repeatable over three acquisitions within 4 weeks) and in the long-term (i.e., reproducible over four acquisition sessions in 5 years). Precision indices varied based on acquisition technique, processing pipeline, and anatomical region. Good repeatability (average CoV=2.40% and ICC=0.78) and reproducibility (average CoV=8.86 % and ICC=0.72) were found over all QIBs. The best performance indices were obtained for diffusion derived biomarkers (CoV∼0.96% and ICCs=0.87); conversely, the poorest indices were found for the cerebral blood flow biomarker (CoV>10% and ICC

In the current economic and environmental context, the selection of livestock phenotypes combining high feed efficiency (FE) and low greenhouse gas emissions is interesting. This study aimed to quantify methane (CH4) emissions and other gas flows (carbon dioxide (CO2) and dihydrogen (H2) emissions, oxygen (O2) consumption) in growing bulls fed with two contrasting diets in order to (i) evaluate the persistence of individual variability in gas flows through time, and (ii) assess the inter-individual relationship between gas flows and FE across diets. Charolais bulls were fattened for 6 months during two consecutive years in two independent batches (50–51 per year). In each batch, half of the animals received a total mixed ad libitum ration either based on maize silage (62% dietary DM) or high-starch concentrate (MS-S), and half based on grass silage (59% dietary DM) and high-fibre concentrate (GS-F). The absolute gas flows (g/d) were individually measured with 2 GreenFeed systems during 88 days (group 1) and 64 days (group 2). All gas flows were also expressed in g/kg DM intake (gas yield), in g/kg average daily gain (CH4 intensity) and residual of daily emissions for CH4 (R CH4). Different FE metrics (residual feed intake (RFI), residual gain (RG) and feed conversion efficiency (FCE)) were investigated during the same period. The relationships between gas flows and FE metrics were tested by linear regression with the diet as fixed effect. For both diets, we observed a consistent individual variability over the measurement period for absolutes values (g/d) of CH4, CO2, and O2 (repeatability >0.7 for GS-F and >0.6 for MS-S). Gas flows (g/d) were positively correlated with RFI with both diets: animals that ingested food in excess of their theoretical maintenance and growth requirements emitted more CH4, CO2 and consumed more O2. The positive relationship between absolute CH4 emissions and RFI highlighted the interest for low-CH4 emitters and efficient growing bulls when fed with high-energy diets rich in starch or fibre. For both diets, RCH4, CH4 yield and CH4 intensity were not related to RFI whereas a significant negative relationship was reported between CH4 intensity and RG, and FCE. These data suggest that intake is the main driver of the phenotypic relationships between CH4 traits and RFI. Further studies including larger numbers of animals on highly contrasting energy diets are needed to investigate the underlying biological regulatory mechanisms of the methanogenic potential of an animal in relation to production traits.

Improving feed efficiency has become an important target for dairy farmers to produce more milk with fewer feed resources. With decreasing availability of arable land to produce feeds that are edible for human consumption, it will be important to increase the proportion of feeds in the diets for dairy cattle that are less edible for human consumption. The current research analyzed the ability of lactating dairy cows to maintain their feed efficiency when switching between a high starch diet (HS diet: 27% starch, 29% NDF, 47.1% forages on a DM basis) and a low starch diet (LS diet: 13% starch, 37% NDF, 66.4% forages on a DM basis). Sixty-two lactating Holstein cows (137 ± 23 days in milk (DIM) at the start of experiment), of which 29 were primiparous cows, were utilized in a crossover design with two 70-d experimental periods, including a 14-d adaption period for each. Feed efficiency was estimated as the individual deviation from the population average intercept in a mixed model predicting DM intake (DMI) with net energy in milk, maintenance and BW gain and loss. Repeatability was estimated within each diet by comparing feed efficiency estimated over the first 28-day period and the second 28-day period within each diet, using Pearson’s and intraclass correlations, and the estimation of error of repeatability. Similarly, reproducibility was estimated by comparing the second 28-day period of one diet with the first 28-day period of the other diet. Feed efficiency was less reproducible across diets than repeatable within the same diet. This was shown by lower intraclass correlations (0.399) across diets compared to that in the HS diet (0.587) and LS diet (0.806), as well as a lower Pearson’s correlation coefficient (0.418) across diets compared to that in the HS diet (0.630) and LS diet (0.809). In addition, the estimation of error of repeatability was higher (0.830 kg DM/d) across diets compared to that in the HS diet (0.761 kg DM/d) and LS diet (0.504 kg DM/d). This means that the feed efficiency of dairy cows is more likely to change after a diet change than over subsequent lactation stages. Other determinants, such as digestive processes, need to be further investigated to determine its effects on estimating feed efficiency.

During the germination of legumes, raffinose family oligosaccharides (RFOs) are decomposed into mono- and disaccharides. As legumes are a traditional part of the human nutrition, storage carbohydrates are generally incorporated in the daily meals and can cause flatulence or even abdominal pain. However, their decomposition products can be metabolized without any difficulty. To date, no validated method is available to quantify the main decomposition products, glucose, and galactose simultaneously with the RFOs and the starch decomposition product maltose in a single measurement without derivatization. To provide a suitable method and fill the existing knowledge gap, a highly sensitive ion chromatography method was established. By using an optimized gradient, the separation of the RFOs, namely raffinose, stachyose, and verbascose, from their decomposition products, including glucose, galactose, fructose, and saccharose was accomplished. An advanced repeatability study proved that the method could be used for up to 4 days until the sample or eluent degradation made further measurement unfeasible. To improve the repeatability while avoiding to overload the chromatogram with several internal standards, a mathematical approach was presented to cope with different decomposition characteristics of the analytes and the internal standard. This study presents a modified and validated method allowing the measurement of all relevant carbohydrates in the germination of legumes. By using only a single method, a high number of samples can be processed. Therefore, a deeper and more detailed insight into the changes in the carbohydrate spectrum during the germination of legumes becomes feasible.

Purpose: This review aimed to synthesize previous findings on the test–retest reliability of the 30–15 Intermittent Fitness Test (IFT). Methods: The literature searches were performed in 8 databases. Studies that examined the test–retest reliability of the 30–15 IFT and presented the intraclass correlation coefficient (ICC) and/or the coefficient of variation (CV) for maximal velocity and/or peak heart rate were included. The consensus-based standards for the selection of health measurement instruments (COSMIN) checklist was used for the assessment of the methodological quality of the included studies. Results: Seven studies, with a total of 10 study groups, explored reliability of maximal velocity assessed by the 30–15 IFT. ICCs ranged from 0.80 to 0.99, where 70% of ICCs were ≥0.90. CVs for maximal velocity ranged from 1.5% to 6.0%. Six studies, with a total of 7 study groups, explored reliability of peak heart rate as assessed by the 30–15 IFT. ICCs ranged from 0.90 to 0.97 (i.e., all ICCs were ≥0.90). CVs ranged from 0.6% to 4.8%. All included studies were of excellent methodological quality. Conclusion: From the results of this systematic review, it can be concluded that the 30–15 IFT has excellent test–retest reliability for both maximal velocity and peak heart rate. The test may, therefore, be used as a reliable measure of fitness in research and sports practice.

Sensors based on inorganic nanomaterials for the detection of human body fluids show great potential in real-time detection and treatment of human health due to their advantages of small size and easy to wear. Nevertheless, most of the existing sensors have the disadvantage of detecting relatively simple substances and suffer from low sensitivity, which undermines their practical applicability in body fluids detection. In this study, based on the transition metal carbide (Ti 3 C 2 T x , MXene)/αFe 2 O 3 grid composite structure, a highly sensitive flexible sensor is proposed, which can realize accurate and simultaneous detection of glucose and uric acid (UA) concentration. The sensor exhibits outstanding durability, enabling it to withstand prolonged immersion in water and exposure to high flow velocities. More importantly, the sensor has extremely high sensitivity for both glucose (2.14 mA mM -1  cm -2 , 5.5 times the mean value) and UA (2.56 μA μM -1  cm -2 , 3.5 times the mean value). It also has the advantage of low detection limits (0.27 μM for glucose and 0.31 μM for UA) and a wide linear detection range (1 mM-40 mM for glucose and 10 μM-900 μM for UA) compared to existing sensors for body fluids detection. In addition, the sensor has excellent repeatability, long shelf life (over 40 days) and excellent immunity to interference (accurate detection of glucose and UA in the presence of multiple metal ions as well as organics in human body fluids). This study establishes the groundwork for developing a production-ready and highly sensitive blood detection sensor capable of real-time monitoring., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Raw data, simulated and acquired phantom images, and quantitative longitudinal and transverse relaxation times (T1/T2) maps from two open-source Magnetic Resonance Imaging (MRI) pulse sequences are presented in this dataset along with corresponding “.seq” files, sequence implementation scripts, and reconstruction/analysis scripts [1]. Real MRI data were collected from a 3T Siemens Prisma Fit and a 1.5T Siemens Aera via the Pulseq open-source MR sequence platform, and corresponding in silico data were generated using the simulation module of Virtual Scanner [2]. This dataset and its associated code can be used to validate the pipeline for using the same pulse sequences at other research sites using Pulseq, to provide guidelines for documenting and sharing open-source pulse sequences in general, and to demonstrate practical, customizable acquisition scripts using the PyPulseq library.

Abstract Background The T 1 Mapping and Extracellular volume (ECV) Standardization (T1MES) program explored T 1 mapping quality assurance using a purpose-developed phantom with Food and Drug Administration (FDA) and Conformité Européenne (CE) regulatory clearance. We report T 1 measurement repeatability across centers describing sequence, magnet, and vendor performance. Methods Phantoms batch-manufactured in August 2015 underwent 2 years of structural imaging, B 0 and B 1, and “reference” slow T 1 testing. Temperature dependency was evaluated by the United States National Institute of Standards and Technology and by the German Physikalisch-Technische Bundesanstalt. Center-specific T 1 mapping repeatability (maximum one scan per week to minimum one per quarter year) was assessed over mean 358 (maximum 1161) days on 34 1.5 T and 22 3 T magnets using multiple T 1 mapping sequences. Image and temperature data were analyzed semi-automatically. Repeatability of serial T 1 was evaluated in terms of coefficient of variation (CoV), and linear mixed models were constructed to study the interplay of some of the known sources of T 1 variation. Results Over 2 years, phantom gel integrity remained intact (no rips/tears), B 0 and B 1 homogenous, and “reference” T 1 stable compared to baseline (% change at 1.5 T, 1.95 ± 1.39%; 3 T, 2.22 ± 1.44%). Per degrees Celsius, 1.5 T, T 1 (MOLLI 5s(3s)3s) increased by 11.4 ms in long native blood tubes and decreased by 1.2 ms in short post-contrast myocardium tubes. Agreement of estimated T 1 times with “reference” T 1 was similar across Siemens and Philips CMR systems at both field strengths (adjusted R 2 ranges for both field strengths, 0.99–1.00). Over 1 year, many 1.5 T and 3 T sequences/magnets were repeatable with mean CoVs

Purpose: To assess the repeatability of measures for dry eye disease (DED) symptoms and signs in the DREAM study., Methods: At screening and baseline visits approximately 2 weeks apart, participants were assessed for symptoms by Ocular Surface Disease Index (OSDI) and Brief Ocular Discomfort Index (BODI), and signs by the same physician in the same order: tear break-up time (TBUT), corneal staining, conjunctival staining, Meibomian gland evaluation, and the Schirmer test. The repeatability of DED symptoms and signs was assessed by interclass correlation coefficient (ICC), 95 % limits of agreement, and the percent of eyes with inter-visit difference above the clinically significant threshold., Results: Among 1046 eyes (523 participants), ICC for signs ranged from 0.53 (TBUT) to 0.73 (corneal staining). A substantial percentage of eyes showed clinically significant inter-visit differences: ≥2 points in 17.8 % of eyes for conjunctival staining; ≥3 points in 18.8 % for corneal staining; >2 s in 14.1 % for TBUT; ≥5 mm/5 min in 29.9 % for the Schirmer test, and ≥ 2 points in 27.5 % for Meibomian gland plugging and lid secretion. The OSDI and BODI had ICC of 0.64 and 0.63 respectively, and nearly 40 % of participants had inter-visit score differences ≥ 10 points., Conclusion: In DREAM participants with moderate-to-severe DED, DED signs and symptoms had moderate repeatability, with ocular surface staining scores being the most repeatable and TBUT the least repeatable. A notable percentage of participants had inter-visit differences above the clinically meaningful threshold. These test-retest variabilities in DED signs and symptoms should be considered for designing clinical trials and monitoring disease progression., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Single-point standard addition, along with internal standard calibration (SSA-IS), is investigated as a new protocol in cadmium quantification by square wave anodic stripping voltammetry (SWASV) and using bismuth film/glassy carbon electrode (Bi/GCE). The bismuth oxidation signal used as an in situ internal standard compensates for random variations between measurements. Moreover, the SSA-IS calibration method is proposed as a practical solution to the passivation of the working electrode. SSA-IS improves the results (RSD = 6.77 %, bias = 5.16 %), compared to the multi-point external standard calibration without internal standard (ESC), (RSD = 29.71 %, bias = 58.80 %) and with internal standard (ESC-IS), (RSD = 6.88 %, bias = 29.23 %). Also, the uncertainty and trueness of the proposed method were estimated and compared with the NIST 3108 reference material. An average concentration of 9.77 ± 0.96 mg g−1 was obtained, which statistically agrees with the certified value of the NIST reference material, 10.007 ± 0.027 mg g−1. Using the SSA-IS method improves the metrological qualities of the analytical technique, making the methodology ready to be tested in real samples such as cocoa.

Additive manufacturing has entered the phase of industrial adoption, for which its quality repeatability is of vital importance to industries where functional parts with consistent mechanical properties are desired. This concern will manifest with large scale implementation of such technology, affecting not only the reliability of products but the reputation and profitability of a business. The root cause to this problem is obscure demanding a systematic approach to identify potential influencing parameters for better process control. In this article, the quality repeatability of laser powder bed fusion (L-PBF) technology, in terms of static mechanical properties of printed parts, was quantified using relative standard deviation, and a machine learning approach for root cause analysis was demonstrated. While most of the prior work focused on the effect of laser-related process parameters to part properties, this research emphasises on the downstream production parameters while keeping laser-related parameters fixed. It was found that the combinational effect of part location and post-chamber pressure drop heavily influences the quality of printed parts. A follow-up experiment with the new process control was able to produce parts with improved quality repeatability. This proves the effectiveness of the proposed approach for process control of L-PBF at large scale implementation.

Background: The forskolin-induced swelling (FIS) assay measures CFTR function on patient-derived intestinal organoids (PDIOs) and may guide treatment selection for individuals with Cystic Fibrosis (CF). The aim of this study is to demonstrate the repeatability and reproducibility of the FIS assay following a detailed Standard Operating Procedure (SOP), thus advancing the validation of the assay for precision medicine (theranostic) applications., Methods: Over a 2-year period, FIS responses to CFTR modulators were measured in four European labs. PDIOs from six subjects with CF carrying different CFTR genotypes were used to assess the repeatability and reproducibility across the dynamic range of the assay., Results: Technical, intra-assay repeatability was high (Lin's concordance correlation coefficient (CCC) 0.95-0.98). Experimental, within-subject repeatability was also high within each lab (CCCs all >0.9). Longer-term repeatability (>1 year) showed more variability (CCCs from 0.67 to 0.95). The reproducibility between labs was also high (CCC ranging from 0.92 to 0.97). Exploratory analysis also found that between-lab percentage of agreement of dichotomized CFTR modulator outcomes for predefined FIS thresholds ranged between 78 and 100 %., Conclusions: The observed repeatability and reproducibility of the FIS assay within and across different labs is high and support the use of FIS as biomarker of CFTR function in the presence or absence of CFTR modulators., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Diffusion weighted imaging (DWI) with optimized motion-compensated gradient waveforms reduces signal dropouts in the liver and pancreas caused by cardiovascular-associated motion, however its precision is unknown. We hypothesized that DWI with motion-compensated DW gradient waveforms would improve apparent diffusion coefficient (ADC)-repeatability and inter-reader reproducibility compared to conventional DWI in these organs., Methods: In this IRB-approved, prospective, single center study, subjects recruited between October 2019 and March 2020 were scanned twice on a 3 T scanner, with repositioning between test and retest. Each scan included two respiratory-triggered DWI series with comparable acquisition time: 1) conventional (monopolar) 2) motion- compensated diffusion gradients. Three readers measured ADC values. One-way ANOVA, Bland-Altman analysis were used for statistical analysis., Results: Eight healthy participants (4 male/4 female), with a mean age of 29 ± 4 years, underwent the liver and pancreas MRI protocol. Four patients with liver metastases (2 male/2 female) with a mean age of 58 ± 5 years underwent the liver MRI protocol. In healthy participants, motion-compensated DWI outperformed conventional DWI with mean repeatability coefficient of 0.14 × 10 -3 (CI:0.12-0.17) vs. 0.31 × 10 -3 (CI:0.27-0.37) mm 2 /s for liver, and 0.11 × 10 -3 (CI:0.08-0.15) vs. 0.34 × 10 -3 (CI:0.27-0.49) mm 2 /s for pancreas; and with mean reproducibility coefficient of 0.20 × 10 -3 (CI:0.18-0.23) vs. 0.51 × 10 -3 (CI:0.46-0.58) mm 2 /s for liver, and 0.16 × 10 -3 (CI:0.13-0.20) vs. 0.42 × 10 -3 (CI:0.34-0.52) mm 2 /s for pancreas. In patients, improved repeatability was observed for motion-compensated DWI in comparison to conventional with repeatability coefficient of 0.51 × 10 - 3  mm 2 /s (CI:0.35-0.89) vs. 0.70 × 10 -3  mm 2 /s (CI:0.49-1.20)., Conclusion: Motion-compensated DWI enhances the precision of ADC measurements in the liver and pancreas compared to conventional DWI., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Manufacturers and diagnostic companies often recommend on-site verification of analytical performance in the clinical laboratory. The validation process used by manufacturers is rarely described in detail, and certain information on analytical performance is missing from the product sheet, especially for immunoanalytical methods. We describe an approach to the detailed validation of an ELISA method for the measurement of proprotein convertase subtilisin/kexin type 9 (PCSK9) plasma concentrations. We compared manufacturers' claims of analytical performance with data obtained in the field laboratory using several approaches., Methods: We used the Human Proprotein Convertase 9/PCSK9 Quantikine ELISA diagnostic kit (R&D systems, Bio-Techne Ltd., Abingdon Science Park, Abingdon, UK) and three levels of quality control solution Quantikine Immunoassay Control Group 235 (R&D systems, Bio-Techne Ltd., Abingdon Science Park, Abingdon, UK) to verify precision. We measured the concentration of PCSK9 using the DS2 ELISA Reader (Dynex Technologies GmbH, Denkendorf, Germany). We used analysis of variance (ANOVA) and the R statistical package (R core team, version 1.4.5). Statistical analysis and terminology were performed according to protocol CLSI EP15-A3, and the reference interval was checked according to CLSI/IFCC C28-A3c., Results: We found a significant difference between the manufacturer's claims of analytical performance and real data measured in the routine clinical laboratory. The calculated CV (%) for repeatability (calculated by simple estimation of the mean and SD, as used by the manufacturer) was between 5.5% and 7.4%, but the manufacturer's claim was between 4.1% and 6.5%. Using ANOVA, the true repeatability was between 5.0% and 6.9%. Similarly, ANOVA revealed values of CV (%) for within-laboratory imprecision between 6.5% and 9.1%, while the manufacturer's claims were between 4.1% and 5.9%. The recovery ranged from 105.5% to 121.8%. The manufacturer's recommended reference interval was checked and we didn't find any significant difference between men and women., Conclusions: We describe a comprehensive approach to verify the analytical performance of an ELISA method using the measurement of PCSK9 plasma concentration as an example. We found differences between the results of this approach based on the CLSI EP15-A3 protocol and data provided by the manufacturer. We recommend the verification of analytical performance by more complex statistical tools in laboratory practice., (Copyright © 2023. Published by Elsevier B.V.)

The sensitivity and repeatability are crucial for the practical application of electrochemical sensors. Many studies have focused on sensing materials and electrode structure to enhance sensitivity and repeatability rather than insulating layers. In this paper, polyaniline (PANI) microelectrode arrays were prepared to explore the influence of the insulating layer on sensitivity and repeatability of electrochemical sensors. The effects of different types of insulating layers, the sizes of the electrodes, and the thicknesses of the insulating layers were studied by experiment and simulation. The research findings indicated that the kind of organic insulating layers (Polyimide (PI) and SU-8) did not have a significant effect on the performance of the sensors. However, as the electrode area increased, the PANI film deposited on the electrode exhibited improved uniformity and density, leading to significant improvements in sensitivity and repeatability of the sensors. Additionally, the thickness of the insulating layer also had a significant impact on the performance of the device. The microelectrode with thinner insulating layers exhibited improved performance in sensitivity, repeatability and signal-to-noise ratio. The research findings indicated that increasing the electrode size and reducing the thickness of the insulating layer led to a more uniform and dense PANI film, resulting in an array electrode that exhibits excellent performance and remarkable repeatability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Feed utilization efficiency is an important trait in dairy production playing a significant role in reducing feed costs and lowering methane emission. One of the metrics used to measure feed efficiency in dairy cows is residual feed intake (RFI). This metric requires routine measurement of feed intake. Since there is a positive high correlation between heat production and carbon dioxide (CO 2 ) production on the one hand and heat production and efficiency on the other hand, residual carbon dioxide (RCO 2 ) might be a useful metric to improve feed efficiency. The objectives of this study were to model the trajectories of RCO 2 and RFI as well as to estimate their repeatabilities and correlations at different stages of lactation. Daily CO 2 output and feed intake were recorded from 46 primiparous Nordic Red dairy cows using two Greenfeed Emissions Monitoring™ systems from 2 to 305 days in milk (DIM). Edited data comprised 5 995 daily averages. To calculate predicted values of CO 2 and DM intake (DMI), prediction models were developed by fitting multiple regression models to observations. Subsequently, RCO 2 and RFI were calculated by subtracting predicted values of CO 2 and DMI from their corresponding actual observations. A random regression bivariate model was fitted to estimate repeatabilities and animal correlations within lactation at different DIMs between RCO 2 and RFI traits. The model fitted included fixed effects of year-month of recording, lactation month, fixed regressions as well as random regressions for the animal effect. The residual variance was considered to be heterogeneous. Repeatabilities and animal correlations of RCO 2 and RFI between selected DIM (for every 30 DIM i.e., 6, 36,…, 246 and 276) were calculated. Repeatability of RCO 2 was high at the beginning of lactation (0.72 at DIM 6) and decreased around the peak of milk production (0.27 at DIM 96) and again increased gradually toward the end of lactation. Similarly, RFI also had high repeatability at the beginning (0.86 at DIM 6); however, it decreased in mid-lactation (0.37 at DIM 156) and then increased toward the end of lactation. Animal correlations between RCO 2 and RFI were moderate to high on the same DIM and ranged from 0.37 to 0.88. Overall, we found that animals with higher CO 2 production than expected also consume more DMI than expected, but the moderate correlation between RCO 2 and RFI found in this study calls for more research to assess the potential of RCO 2 to become a new feed efficiency metric., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The contamination of natural systems with plastic debris has become one of the most pressing global environmental issues. Microplastics (MPs) are of particular concern because their ubiquity and small size make them available for ingestion by a range of aquatic biota. MP exposure studies are hence proliferating rapidly but are typically limited to the analyses of population-level responses in toxicity endpoints across treatments. Potential contaminant-induced alterations in behavioural patterns, however, could manifest on numerous levels of variation: at the population-level, between individuals and within individuals. Here, we used repeated measures on startle response durations – a risk-avoidance mechanism – in European hermit crabs, Pagurus bernhardus, to measure behavioural responses to MP exposure across multiple levels of variation. We found that MP exposure led to a significant decrease of startle duration at the population-level as well as a reduction of intra-individual variation. In other words, crabs became less risk averse on average and their behaviour became more predictable with increasing MP concentrations. Collectively, our findings indicate that MP pollution might increase susceptibility to predation in hermit crabs.

Summary: Objective: Meniscal damage is one of risk factors for the development of knee osteoarthritis (KOA). Medial meniscal extrusion (MME) is associated with the progression of cartilage loss in the medial compartment. The objective of this study was to determine the intra-rater repeatability of our method of three-dimensionally analyzing MME in patients with KOA. Design: Eight knees with medial KOA were examined in participants aged between fifty and eighty years old. We created three-dimensional models of the tibia and medial meniscus using a 0.4 Tesla MRI scanner and embedded a local coordinate system into the tibia. Repeatability of measurements of the MME volume and width were tested using intraclass correlation coefficient (ICC). Results: The ICC for measuring the MME volume was 0.998 [95% confidence interval, 0.992, 1.000]. Measurement error for the MME volume was 0.5–7.0%. The ICC for measuring the MME width was 0.983 [0.924, 0.996]. Measurement error for the MME width was 0.0–11.4%. There was no correlation between the MME volume and width (r = 0.565, p = 0.145). Conclusions: This study concluded that three-dimensional volume and width measurements of the MME by a single rater using MRI images had high repeatability even in the limited image quality. The result of non-significant correlation between the MME width and volume suggests that MME width measured using a low-magnet MRI scanner not considered reliable. Further studies are needed to determine the association between the MME volume and disease progression of KOA.

Multi-sire mating of a mob of ewes is commonly used in commercial sheep production systems. However, ram mating success (defined as the number of lambs sired by an individual) can vary between rams in the mating group. If this trait was repeatable and heritable, selection of rams capable of siring larger numbers of lambs could reduce the number of rams required for mating and ultimately lead to increased genetic gain. However, genetic correlations with other productive traits, such as growth and female fertility, could influence the potential for ram mating success to be used as a selection trait. In order to investigate this trait, parentage records (including accuracy of sire assignment) from 15 commercial ram breeding flocks of various breeds were utilised to examine the repeatability and heritability of ram mating success in multi-sire mating groups. In addition, genetic and phenotypic correlations with growth and female fertility traits were estimated using ASReml. The final model used for the ram mating success traits included age of the ram and mating group as fixed effects. Older rams (3+years old) had 15% to 20% greater mating success than younger rams (1 or 2 years of age). Increasing the stringency of the criteria for inclusion of both an individual lamb, based on accuracy of sire assignment, or a whole mating group, based on how many lambs had an assigned sire, increased repeatability and heritability estimates of the ram mating success traits examined. With the most stringent criteria employed, where assignment of sire accuracy was >0.95 and the total number of lambs in the progeny group that failed to have a sire assigned was

Abstract Background Quantification and visualisation of left ventricular (LV) blood flow is afforded by three-dimensional, time resolved phase contrast cardiovascular magnetic resonance (CMR 4D flow). However, few data exist upon the repeatability and variability of these parameters in a healthy population. We aimed to assess the repeatability and variability over time of LV 4D CMR flow measurements. Methods Forty five controls underwent CMR 4D flow data acquisition. Of these, 10 underwent a second scan within the same visit (scan-rescan), 25 returned for a second visit (interval scan; median interval 52 days, IQR 28–57 days). The LV-end diastolic volume (EDV) was divided into four flow components: 1) Direct flow: inflow that passes directly to ejection; 2) Retained inflow: inflow that enters and resides within the LV; 3) Delayed ejection flow: starts within the LV and is ejected and 4) Residual volume: blood that resides within the LV for > 2 cardiac cycles. Each flow components’ volume was related to the EDV (volume-ratio). The kinetic energy at end-diastole (ED) was measured and divided by the components’ volume. Results The dominant flow component in all 45 controls was the direct flow (volume ratio 38 ± 4%) followed by the residual volume (30 ± 4%), then delayed ejection flow (16 ± 3%) and retained inflow (16 ± 4%). The kinetic energy at ED for each component was direct flow (7.8 ± 3.0 microJ/ml), retained inflow (4.1 ± 2.0 microJ/ml), delayed ejection flow (6.3 ± 2.3 microJ/ml) and the residual volume (1.2 ± 0.5 microJ/ml). The coefficients of variation for the scan-rescan ranged from 2.5%–9.2% for the flow components’ volume ratio and between 13.5%–17.7% for the kinetic energy. The interval scan results showed higher coefficients of variation with values from 6.2–16.1% for the flow components’ volume ratio and 16.9–29.0% for the kinetic energy of the flow components. Conclusion LV flow components’ volume and their associated kinetic energy values are repeatable and stable within a population over time. However, the variability of these measurements in individuals over time is greater than can be attributed to sources of error in the data acquisition and analysis, suggesting that additional physiological factors may influence LV flow measurements.

Background: IgG concentrations in cerebrospinal fluid generally range from 20 to 45 mg/L. In multiple sclerosis immune reactions lead to intrathecal synthesis of specific IgGs that can be detected in biological fluid samples both quantitatively and qualitatively by isoelectric focusing of supplementary oligoclonal IgG bands. Method: A simple tool, using the MATLAB application, to facilitate and improve isoelectric focusing profile analysis is presented and evaluated in terms of its sensitivity, repeatability and reproducibility. A comparison between human readers and semi-automatic method has also been performed. Results: Results from the semi-automatic method were found to be equivalent or superior to generally employed laboratory methods. Repeatability analysis for semi-automatic processing yielded coefficients of variation (CVs) in the 3–7% range, and using a sample with an estimated IgG concentration of 200 mg/L, four bands were still visible after dilution to 5 mg/L, corresponding to band concentrations of 1.1–1.6 mg/L. Discordances between visual inspection and automatic analysis only appear at threshold levels for interpretation (the gray zone). Conclusion: The semi-automatic method has acceptable performance for routine implementation.

Purpose: To establish a relationship between the diameter and depth position of vessels in the superior and inferior corneo-scleral limbus using ultra-high resolution optical coherence tomography (UHR-OCT). Methods: Volumetric OCT images of the superior and inferior limbus were acquired from 14 healthy subjects with a research-grade UHR-OCT system. Differences in vessel diameter and depth between superior and inferior limbus were analyzed using repeated measured ANOVA in SPSS and R. Results: The mean (± SD) superior and inferior diameters were 29 ± 18 μm and 24 ± 18 μm respectively, and the mean (± SD) superior and inferior depths were 177 ± 109 μm and 207 ± 132 μm respectively. The superior limbal vessels were larger than the inferior ones (RM-ANOVA, p = 0.004), and the inferior limbal vessels were deeper than the superior vessels (RM-ANOVA, p = 0.041). There was a positive linear association between limbal vessel depth and size within the superior and inferior limbus with Pearson correlation coefficients of 0.803 and 0.754, respectively. Conclusion: This study demonstrated that the UHR-OCT was capable of imaging morphometric characteristics such as the size and depth of vessels in the limbus. The results of this study suggest a difference in the size and depth of vessels across different positions of the limbus, which may be indicative of adaptations to chronic hypoxia caused by the covering of the superior limbus by the upper eyelid. UHR-OCT may be a useful tool to evaluate the effect of contact lenses on the microvascular properties within the limbus.

Objective: The purpose of this investigation was to compare the repeatability of an intraoral scanner (3Shape TRIOS) with the traditional visual method for dental shade matching in patients and to assess the influence of ambient lighting and the observer's sex and experience on visual shade matching. An additional aim was to determine the color dimension for which repeatability is greater with both the visual method and intraoral scanner. Methods: Thirty observers (15 men and 15 women), grouped by professional experience, selected the shade of the right maxillary central incisor in 10 patients on three different occasions under different ambient lighting conditions (twice under studio clinic lighting and once under natural light). The same procedure was repeated using an intraoral scanner. All shades were selected based on the VITA Toothguide 3D-MASTER. The repeatability of each observer and the intraoral scanner were recorded for each color dimension (hue, chroma, and value). Results: The TRIOS intraoral scanner obtained a mean repeatability of 86.66% in dental shade matching compared to 75.22% achieved by the visual method. Ambient lighting had a direct effect on the repeatability of the shade selection for the visual method, whereas the observer's sex and clinical experience did not. For the visual method, the repeatability in dental shade matching depended on the dimension studied, with the best results in value, followed by hue and chroma; however, such dependence was not detected for the intraoral scanner. Conclusions: The TRIOS intraoral scanner ensured better repeatability than the visual method in dental shade matching.

Background: Magnetic resonance imaging (MRI) has many different alterable parameters that affect how an image appears. This is relevant in radiomics which produces quantitative features through analysis of medical images. One significant acknowledged limitation of radiomics is repeatability. This phantom study aims to further investigate the repeatability of radiomic features (RaF), within MRI, across a range of different echo (TE) and repetition times (TR)., Methods: A phantom was scanned 10 times under identical conditions on a 3T scanner using head coil over 4 months. The TE ranged from 80 to 110 ms while the TR from 3000 to 5000 ms. Radiomics analysis was performed on the same segmented section of the phantom across all TE and TR combinations. Intraclass Correlation Coefficient (ICC) was calculated across the different TE and TR ranges to investigate the repeatability of RaF., Results: Of 1596 features calculated, 187 features had ICC >0.9 across the range of TE, while 82 features had an ICC >0.9 across a range of TR. 664 had ICC >0.75 across the range of TEs, with 541 across the range of TR values. There was an overlap of 51 features with ICC >0.9., Conclusion: Repeatability of RaF in MRI is dependent on imaging parameters and careful consideration of these, in combination with variable selection, is required when applying radiomics to MRI., (Copyright © 2023. Published by Elsevier Inc.)

Attempts to lower the environmental footprint of milk production needs a sound understanding of the genetic and nutritional basis of methane (CH4) emissions from the dairy production systems. This in turn requires accurate and reliable techniques for the measurement of CH4 output from individual cows. Many of the available measurement techniques so far are either slow, expensive, labor intensive and are unsuitable for large-scale individual animal measurements. The main objectives of this study were to examine and validate a non-invasive individual cow CH4 measurement system that is based on photoacoustic IR spectroscopy (PAS) technique implemented in a portable gas analysis equipment (F10), referred to as PAS-F10 method and to estimate the magnitude of between-animal variations in CH4 output traits. Data were collected from 115 Nordic Red cows of the Minkiö experimental dairy farm, at the Natural Resources Institute Finland (Luke). Records on continuous daily measurements of CH4, milk yield, feed intake and BW measurements over 2 years period were compiled for data analysis. The daily CH4 output was calculated using carbon dioxide as a tracer method. Estimates from the non-invasive PAS-F10 technique were then tested against open-circuit indirect respiration calorimetric chamber measurements and against estimates from other widely used prediction models. Concordance analysis was used to establish agreement between the chamber and PAS-F10 methods. A linear mixed model was used for the analysis of the large continuous data. The daily CH4 output of cows was 555 l/day and ranged from 330 to 800 l/day. Dry matter intake, level of milk production, lactation stage and diurnal variation had significant effects on daily CH4 output. Estimates of the daily CH4 output from PAS-F10 technique compared relatively well with the other techniques. The concordance correlation coefficient between combined weekly CH4 output estimates of PAS-F10 and chamber was 0.84 with lower and upper confidence limits of 0.65 and 0.93, respectively. Similarly, when chamber CH4 measurements were predicted from PAS-F10 measurements, the mean of two separate weekly PAS-F10 measurements gave the lowest prediction error variance than either of the separate weekly PAS-F10 measurements alone. This suggests that every other week PAS-F10 measurements when combined would improve the estimation of CH4 output with PAS-F10 technique. The repeatability of daily CH4 output from PAS-F10 technique ranged from 0.40 to 0.46 indicating that some between-animal variation exist in CH4 output traits.

Purpose: To analyze single session, intrauser reliability of a Scheimpflug device for anterior chamber (AC) and corneal parameters. Methods: In this observational study, 100 normal candidates underwent Scheimpflug analysis with Sirius 3D Rotating Scheimpflug Camera and Topography System (Costruzione Strumenti Oftalmici, Italy). Two scans in dark room conditions were performed by the same experienced user. The candidates were asked to keep both eyes closed for 5 min before the scans. Exclusion criteria were previous ocular surgery, corneal scarring and anterior segment/posterior segment anomalies. Only the right eyes were used for the analysis. Both corneal (central, minimum, and apical thickness, volume, horizontal visible iris diameter, and apical curvature) and anterior chamber (volume, depth, angle, horizontal diameter) measurements were evaluated. Results: There was no difference in the means of repeated measurements (p > 0.05, ANOVA). Intraclass correlations between the measures were high and ranged from 0.995–0.997 for corneal to 0.964–0.997 for anterior chamber (AC) parameters. The precision of repeatability measures (1.96 × Sw) was approximately 5 μ for the central and minimum corneal thickness, 8 μ for the apical corneal thickness, 0.06 mm for AC (anterior chamber) depth and less than 2° for the AC angle. Conclusions: Sirius Scheimpflug system has high repeatability for both corneal and AC parameters in normal eyes.

Purpose: To evaluate the repeatability of power profiles measured on NIMO TR1504 (Lambda-X, Belgium) and investigate the effects of lens decentration on the power profiles for single vision (SV), bifocal (BF) and multifocal (MF) contact lenses. Methods: Accuracy of the sphere power was evaluated using single vision BK-7 calibration glass lenses of six minus and six plus powers. Three SV and four BF/MF contact lenses – three lenses each, were measured five times to calculate the coefficients of repeatability (COR) of the instrument. The COR was computed for each chord position, lens design, prescription power and operator. One lens from each type was measured with a deliberate decentration up to ±0.5 mm in 0.1 mm steps. Results: For all lenses, the COR varied across different regions of the half-chord position. In general, SV lenses showed lower COR compared to the BF/MF group lenses. There were no noticeable trends of COR between prescription powers for SV and BF/MF lenses. The shape of the power profiles was not affected when lenses were deliberately decentered for all SV and PureVision MF lenses. However, for Acuvue BF lenses, the peak to trough amplitude of the power profiles flattened up to 1.00 D. Conclusion: The COR across the half-chord of the optic zone diameter was mostly within clinical relevance except for the central 0.5 mm half-chord position. COR were dependent on the lens type, whereby BF/MF group produced higher COR than SV lenses. The effects of deliberate decentration on the shape of power profiles were pronounced for lenses where the profiles had sharp transitions of power.

The Corpus Callosum (CC) is an important structure connecting the two brain hemispheres. As several neurodegenerative diseases are known to alter its shape, it is an interesting structure to assess as biomarker. Yet, currently, the CC-segmentation is often performed manually and is consequently an error prone and time-demanding procedure. In this paper, we present an accurate and automated method for corpus callosum segmentation based on T1-weighted MRI images. After the initial construction of a CC atlas based on healthy controls, a new image is subjected to a mid-sagittal plane (MSP) detection algorithm and a 3D affine registration in order to initialise the CC within the extracted MSP. Next, an active shape model is run to extract the CC. We calculated the reliability of most popular CC features (area, circularity, corpus callosum index and thickness profile) in healthy controls, Alzheimer's Disease patients and Multiple Sclerosis patients. Importantly, we also provide inter-scanner reliability estimates. We obtained an intra-class correlation coefficient (ICC) of over 0.95 for most features and most datasets. The inter-scanner reliability assessed on the MS patients was remarkably well and ranged from 0.77 to 0.97. In summary, we have constructed an algorithm that reliably detects the CC in 3D T1 images in a fully automated way in healthy controls and different neurodegenerative diseases. Although the CC area and the circularity are the most reliable features (ICC > 0.97); the reliability of the thickness profile (ICC > 0.90; excluding the tip) is sufficient to warrant its inclusion in future clinical studies.