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Abstract We sought to determine the repeatability of EFL in healthy adults during incremental cycle exercise. We hypothesized that the repeatability of EFL would be “strong” when assessed as a binary variable (i.e., absent or present) but “poor” when assessed as a continuous variable (i.e., % tidal volume overlap). Thirty‐two healthy adults performed spirometry and an incremental cycle exercise test to exhaustion on two occasions. Standard cardiorespiratory variables were measured at rest and throughout exercise, and EFL was assessed by overlaying tidal expiratory flow‐volume and maximal expiratory flow‐volume curves. The repeatability of EFL was determined using Cohen's κ for binary assessments of EFL and intraclass correlation (ICC) for continuous measures of EFL. During exercise, n = 12 participants (38%) experienced EFL. At peak exercise, the repeatability of EFL was “minimal” (κ = 0.337, p = 0.145) when assessed as a binary variable and “poor” when measured as a continuous variable (ICC = 0.338, p = 0.025). At matched levels of minute ventilation during high‐intensity exercise (i.e., >75% of peak oxygen uptake), the repeatability of EFL was “weak” when measured as a binary variable (κ = 0.474, p = 0.001) and “moderate” when measured as a continuous variable (ICC = 0.603, p

Abstract Repeatability involves the assessment of the agreement among repeated measurements from the same cluster of subjects, and this concept has been widely used in different scientific fields when data is structured in clusters. In the context of spatial trajectories, a degree of repeatability implies that individual trips can be distinguished from those of other individuals. Repeatability is usually assessed by the intraclass correlation coefficient (ICC), which is defined as the proportion of the total variance accounted for by among‐subject variability. However, where data are spatial trajectories the common approach to estimate the ICC does not apply because data involves sets of ordered spatial locations rather than single values. In this work, a novel approach based on spatial distances is proposed to estimate the ICC to assess the repeatability of spatial trajectories. The methodology is illustrated with a real case example of the flight trajectories of 36 Audouin's gulls (Ichthyaetus audouinii) moving through a heterogeneous landscape over a period of 18 days. Additionally, simulations were used to evaluate the performance of the approach under various scenarios. I demonstrate that ICC can be estimated on complex, spatially ordered data such as spatial trajectories, when using the appropriate spatial distance.

Abstract Background Lung ultrasound (LUS) is a noninvasive tool for examining respiratory distress patients. The lung ultrasound score (LUSS) can be used to quantify and monitor lung aeration loss with good reliability. Hypothesis/Objectives Assess the reliability of a new LUSS among raters with different levels of experience and determine how well the same raters agree on identifying patterns of LUS abnormalities. Animals Forty LUS examinations of dogs and cats and 320 videos were reviewed from a digital database. Methods Retrospective reliability study with post hoc analysis. Protocolized LUS were randomly selected; intrarater and interrater reliability of the LUSS and pattern recognition agreement among 4 raters with different levels of experience in LUS were tested. Results The intrarater intraclass correlation coefficient (ICC) single measurement, absolute agreement, and 2‐way mixed effects model was 0.967 for the high‐experience rater (H‐Exp), 0.963 and 0.952 for the medium‐experience raters (M‐Exp‐1; M‐Exp‐2), and 0.950 for the low‐experience rater (L‐Exp). The interrater ICC average measurement, absolute agreement, and 2‐way random effects model among the observers was 0.980. The Fleiss' kappa (k) values showed almost perfect agreement (k = 1) among raters in identifying pleural effusion and translobar tissue‐like pattern, strong agreement for A‐lines (k = 0.881) and B‐lines (k = 0.806), moderate agreement (k = 0.693) for subpleural loss of aeration, and weak agreement (k = 0.474) for irregularities of the pleural line. Conclusions and Clinical Importance Our results indicate excellent intra‐ and interrater reliability for LUS scoring and pattern identification, providing a foundation for the use of the LUSS in emergency medicine and intensive care.

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.

Abstract Contrast‐enhanced ultrasound (CEUS) can be used to directly assess skeletal muscle perfusion. However, its repeatability over time has not yet been validated and therefore its use in longitudinal measures (i.e., exploring the impact of a chronic intervention or disease progression) is limited. This study aimed to determine the repeatability of CEUS for the measurement of skeletal muscle microvascular blood flow (MBF) at baseline and in response to exercise, across independent assessment sessions. Ten healthy volunteers (five female; 30 ± 6 years) had CEUS of the right vastus lateralis recorded in two separate sessions, 14 days apart. Measurements were taken at baseline, during an isometric leg extension and during recovery. Acoustic intensity data from a region of interest were plotted as a replenishment curve to obtain blood volume (A) and flow velocity (β) values from a one‐phase association non‐linear regression of mean tissue echogenicity. Linear regression and Bland–Altman analyses of A and β values were performed, with significance assumed as P

Abstract DLCO/NO, the combined single‐breath measurement of the diffusing capacity to carbon monoxide (DLCO) and nitric oxide (DLNO) measured either during exercise or in the resting supine position may be a useful physiological measure of alveolar–capillary reserve. In the present study, we investigated the between‐day test–retest reliability of DLCO/NO‐based metrics. Twenty healthy volunteers (10 males, 10 females; mean age 25 (SD 2) years) were randomized to repeated DLCO/NO measurements during upright rest followed by either exercise (n = 11) or resting in the supine position (n = 9). The measurements were repeated within 7 days. The smallest real difference (SRD), defined as the 95% confidence limit of the standard error of measurement (SEM), the coefficient of variance (CV), and intraclass correlation coefficients were used to assess test–retest reliability. SRD for DLNO was higher during upright rest (5.4 (95% CI: 4.1, 7.5) mmol/(min kPa)) than during exercise (2.7 (95% CI: 2.0, 3.9) mmol/(min kPa)) and in the supine position (3.0 (95% CI: 2.1, 4.8) mmol/(min kPa)). SRD for DLCOc was similar between conditions. CV values for DLNO were slightly lower than for DLCOc both during exercise (1.5 (95% CI: 1.2, 1.7) vs. 3.8 (95% CI: 3.2, 4.3)%) and in the supine position (2.2 (95% CI: 1.8, 2.5) vs. 4.8 (95% CI: 3.8, 5.4)%). DLNO increased by 12.3 (95% CI: 11.1, 13.4) and DLCOc by 3.3 (95% CI: 2.9, 3.7) mmol/(min kPa) from upright rest to exercise. The DLCO/NO technique provides reliable indices of alveolar–capillary reserve, both during exercise and in the supine position.

Abstract Aggressive behaviour is thought to have significant consequences for fitness, sexual selection and the evolution of social interactions, but studies measuring its expression across successive encounters—both intra‐ and intersexual—are limited. We used the field cricket Teleogryllus oceanicus to evaluate factors affecting repeatability of male aggression and its association with mating success. We quantified focal male aggression expressed towards partners and received from partners in three successive, paired trials, each involving a different male partner. We then measured a proxy of focal male fitness in mating trials with females. The likelihood and extent of aggressive behaviour varied across trials, but repeatability was negligible, and we found no evidence that patterns of focal aggression resulted from interacting partner identity or prior experience. Males who consistently experienced aggression in previous trials showed decreased male mating ‘efficiency’—determined by the number of females a male encountered before successfully mating, but the effect was weak and we found no other evidence that intrasexual aggression was associated with later mating success. During mating trials, however, we observed unexpected male aggression towards females, and this was associated with markedly decreased male mating efficiency and success. Our findings suggest that nonadaptive aggressive spillover in intersexual mating contexts could be an important but underappreciated factor influencing the evolution of intrasexual aggression.

Abstract Receiving the same results from repeated analysis of the same sample is a basic principle in science. The inability to reproduce previously published results has led to discussions of a reproducibility crisis within science. For studies of microbial communities, the problem of reproducibility is more pronounced and has, in some fields, led to a discussion on the very existence of a constantly present microbiota. In this study, DNA from 44 bovine milk samples were extracted twice and the V3–V4 region of the 16S rRNA gene was sequenced in two separate runs. The FASTQ files from the two data sets were run through the same bioinformatics pipeline using the same settings and results from the two data sets were compared. Milk samples collected maximally 2 h apart were used as replicates and permitted comparisons to be made within the same run. Results show a significant difference in species richness between the two sequencing runs although Shannon and Simpson's diversity was the same. Multivariate analyses of all samples demonstrate that the sequencing run was a driver for variation. Direct comparison of similarity between samples and sequencing run showed an average similarity of 42%–45% depending on whether binary or abundance‐based similarity indices were used. Within‐run comparisons of milk samples collected maximally 2 h apart showed an average similarity of 39%–47% depending on the similarity index used and that similarity differed significantly between runs. We conclude that repeated DNA extraction and sequencing significantly can affect the results of a low microbial biomass microbiota study.

Abstract Calibrated digital photography is frequently used in studies focusing on avian eggshell appearance to measure colour and pattern features. Photographs are often taken in natural light conditions, yet little is known to what extent the normalisation process is able to control for varied light. Here, we photographed 36 blown eggs of the Japanese quail Coturnix japonica at five different elevation angles of the sun on both sunny and uniformly overcast days alongside grey standards. We normalised and processed the photographs in the MICA Toolbox software and checked how much noise was introduced by different natural light conditions to the colour and pattern measurements of the same set of eggs. Our results indicate that natural variation of light conditions affects eggshell colour and pattern measurements obtained by means of calibrated digital photography. Depending on a trait, the elevation angle of the sun had similar or even greater effect on the measurement than the presence of the cloud cover. Furthermore, measurements taken in cloudy conditions were more repeatable than those taken in sunny conditions. Based on the results, we propose practical guidelines regarding measuring colour and pattern of eggshells using calibrated digital photography in outdoor conditions.

Birds that repeatedly visit distinct places along their migratory routes in consecutive years must be able to navigate to these places and respond appropriately to unfavourable wind conditions. This study analysed the migratory routes, repeatedly‐visited areas and responses to sidewinds of 15 GPS‐tracked adult ospreys Pandion haliaetus from northeast Germany migrating to their wintering sites in Africa and back. We determined stopovers and intermediate goal areas and performed repeatability estimations on timing and migratory paths in four regions. The orientation behaviour of the ospreys was analysed with regard to perpendicular wind components at each GPS point during autumn and spring migrations. Generalised linear mixed models were used to test the dependence of orientation behaviour on region and the distance to the next goal. The findings showed that ospreys demonstrate high fidelity to migratory paths in autumn and spring, as well as to the timing of migration in autumn; and sidewinds are predominantly compensated, especially when sidewinds are strong. Furthermore, during autumn migration, the proportion of compensation increases in most regions with decreasing distances to the next goal; however, during spring migration, drift behaviour was detected more often at smaller distances to the next goal than at higher distances in the regions Mediterranean and central Europe. In general, ospreys compensate for unfavourable sidewinds and utilise supporting tailwinds on their journeys to the wintering sites in Africa and back to central Europe.

The detection of a secondary inorganic phosphate (Pi) resonance, a possible marker of mitochondrial content in vivo, using phosphorus magnetic resonance spectroscopy ( 31 P-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 (Pi alk ) using with 31 P-MRS at 3 T. After an initial set of experiments on five subjects to optimize the sequence, resting 31 P-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. 31 P-MRS data were acquired with a 31 P/-proton ( 1 H) 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, Pi alk 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 Pi alk quantitation variability (CV: 28 ± 5%), due to magnetic field inhomogeneity with more distal coil locations. In contrast, Pi alk 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 Pi alk 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., (© 2024 The Author(s). NMR in Biomedicine published by John Wiley & Sons Ltd.)

Purpose: Compared with lower field strengths, DWI at 7 T faces the combined challenges of increased distortion and blurring due to B 0 inhomogeneity, and increased signal dropouts due to B 1 + inhomogeneity. This study addresses the B 1 + 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 B 1 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.+ 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., (© 2024 International Society for Magnetic Resonance in Medicine.)

Abstract Background There is currently a lack of reference intervals (RIs) for the novel measures like 3‐dimensional (3D) echocardiography or speckle‐tracking strain for assessment of right ventricular (RV) structure and function. Objectives To generate RIs and to determine the influence of age, heart rate, and body weight (BW) on various RV function indices using a dedicated RV software for 3D RV end‐diastolic volume (EDV), end‐systolic volume (ESV), ejection fraction (EF), global and free wall RV longitudinal strain (RVLS), end‐diastolic area (RVEDA), end‐systolic area (RVESA), fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and tissue Doppler imaging (TVI)‐derived systolic myocardial velocity of the lateral tricuspid annulus (S′). Animals Healthy adult client‐owned dogs (n = 211) of various breeds and ages. Methods Prospective study. Reference intervals were estimated as statistical prediction intervals using allometric scaling for BW‐dependent variables. Right‐sided (upper limit) or left‐sided (lower limit) 95% RIs were calculated for every variable. Inter‐ and intraobserver variability was determined. Results Most variables showed clinically acceptable repeatability with coefficient of variation less than 10. Upper or respectively lower RI after allometric scaling to normalize for different BWs were: EDVn ≤ 2.5 mL/kg0.942, ESVn ≤ 1.2 mL/kg0.962, TAPSEn ≥ 4.5 mm0.285, RVEDAn ≤ 1.4 cm2/kg0.665, RVESAn ≤ 0.8 cm2/kg0.695, and TVI S′n ≥ 5.6 cm/s/kg0.186. The calculated limits for indices without allometric normalization were: EF > 42.1%, FAC > 30.0%, free wall RVLS

Abstract Animal personality has received increasing interest and acknowledgment within ecological research over the past two decades. However, some areas are still poorly studied and need to be developed. For instance, field studies focused on invertebrates are currently highly underrepresented in the literature. More studies including a wider variety of traits measured and species tested are needed to improve our understanding of trait‐correlation patterns and generalities. We studied nine behavioral traits, in the damselfly Calopteryx splendens, from an array of three experiments: (i) courtship, (ii) aggressiveness, and (iii) boldness, and calculated their repeatability. The behaviors were measured twice in two different contexts: (i) undisturbed territory and (ii) partially deteriorated territory. Traits related to courtship and boldness were all repeatable across the two contexts. Among aggressive behaviors, only one trait (number of hits) was repeatable. This work demonstrates, for the first time, the presence of within‐population personality differences in an adult damselfly in the wild. We further propose C. splendens as a promising model species for testing personality in the wild under highly controlled environmental conditions.

Abstract Repeatability is the cornerstone of science, and it is particularly important for systematic reviews. However, little is known on how researchers’ choice of database, and search platform influence the repeatability of systematic reviews. Here, we aim to unveil how the computer environment and the location where the search was initiated from influence hit results. We present a comparative analysis of time‐synchronized searches at different institutional locations in the world and evaluate the consistency of hits obtained within each of the search terms using different search platforms. We revealed a large variation among search platforms and showed that PubMed and Scopus returned consistent results to identical search strings from different locations. Google Scholar and Web of Science's Core Collection varied substantially both in the number of returned hits and in the list of individual articles depending on the search location and computing environment. Inconsistency in Web of Science results has most likely emerged from the different licensing packages at different institutions. To maintain scientific integrity and consistency, especially in systematic reviews, action is needed from both the scientific community and scientific search platforms to increase search consistency. Researchers are encouraged to report the search location and the databases used for systematic reviews, and database providers should make search algorithms transparent and revise access rules to titles behind paywalls. Additional options for increasing the repeatability and transparency of systematic reviews are storing both search metadata and hit results in open repositories and using Application Programming Interfaces (APIs) to retrieve standardized, machine‐readable search metadata.

Abstract Field ecology has been included in a ‘replication crisis’ that extends across many scientific disciplines. However, the underlying concepts of replication, reproducibility and replicability are not always clearly distinguished, and complicate the identification of best practices. Furthermore, conducting experiments under the high variability of natural field conditions reduces the capacity for replication relative to other biological disciplines working under controlled conditions. Field ecologists are therefore facing a significant challenge in assessing the replicability of their research with implications for overall confidence in study outcomes. Through a review of the literature, we discuss several related aspects of experimental design that can enhance confidence in scientific outcomes. Specifically, we describe sample replication (repeat sample), within‐study replication (repeat experiment) and between‐study replication (repeat study) and how each can be used within field ecology. Since perfect between‐study replication (i.e. direct replication) is generally not possible in field ecology, we suggest more explicit use of conceptual replication would enhance confidence in scientific outcomes. However, such changes require cultural shifts in practice among all participants in the scientific enterprise. We suggest several tangible steps could be taken to improve confidence in ecological research: (a) increase the use of within‐study replication before publication, (b) increase replicability for aspects that we can control (e.g. pre‐register experiments, open data, publish code), (c) divest from novelty as the primary criterion for publication in leading ecological journals and invest in experimental design, (d) be sceptical of contradictory findings from studies testing similar research questions and (e) create a publishing environment that encourages more conceptual replication studies. We believe adopting these practices will increase the confidence in results for field ecology. There are critical obstacles that could prevent some scientists from increasing within‐study or between‐study replication, including short‐term funding mechanisms and the prospect of fewer publications. We suggest strategies to mitigate negative impacts to researchers, such as leading journals piloting new article categories and explicit mention of experimentally linked studies. We acknowledge that adopting greater replication in field ecology will require significant changes to cultural practices, but there are clear benefits for improving our confidence in science.

Abstract Evolutionary biologists have long sought to understand what factors affect the repeatability of adaptive outcomes. To better understand the role of temperature in determining the repeatability of adaptive trajectories, we evolved populations of different genotypes of the ciliate Tetrahymena thermophila at low and high temperatures and followed changes in growth rate over 6,500 generations. As expected, growth rate increased with a decelerating rate for all populations; however, there were differences in the patterns of evolution at the two temperatures. The growth rates of the different genotypes tended to converge as evolution proceeded at both temperatures, but this convergence was quicker and more pronounced at the higher temperature. Additionally, over the first 4,000 generations we found greater repeatability of evolution, in terms of change in growth rate, among replicates of the same genotype at the higher temperature. Finally, we found limited evidence of trade‐offs in fitness between temperatures, and an asymmetry in the correlated responses, whereby evolution in a high temperature increases growth rate at the lower temperature significantly more than the reverse. These results demonstrate the importance of temperature in determining the repeatability of evolutionary trajectories for the eukaryotic microbe Tetrahymena thermophila and may provide clues to how temperature affects evolution more generally.

Abstract The obesity epidemic is concerning as obesity appears to negatively impact cognition and behavior. Furthermore, some studies suggest that this negative effect could be carried across generations from both mothers and fathers although evidence is not consistent. Here, we attempt to address how obesogenic diets in the parental generation (F0) can impact offspring's cognition and anxiety intergenerationally (F1) in a zebrafish model. We compare both mean trait values and their variances. Using a multifactorial design, we created a total of four groups: F1T (treatment mothers × treatment fathers); F1M (treatment mothers × control fathers); F1P (treatment fathers × control mothers); and F1C (control mothers × control fathers, F1C); and subjected them to anxiety tank tests and aversive learning assays. When both parents were exposed, offspring (F1T) displayed the poorest aversive learning, while offspring that only had one parent exposed (F1P and F1M) learnt the aversive learning task the best. Zebrafish in all groups displayed no statistically significant differences in anxiety‐associated behaviors. Males and females also performed similarly in both anxiety and aversive learning assays. While all F1 groups had similar levels of fasting blood glucose, variance in glucose levels were reduced in F1P and F1T indicating the importance of investigating heteroskedasticity between groups. Furthermore, anxiety behaviors of these two groups appeared to be less repeatable. To our knowledge, this is the first study to test the intergenerational effects of an obesogenic diet on zebrafish cognition. Our multifactorial design as well as repeated tests also allowed us to disentangle maternal and paternal effects (as well as combined effects) and accurately detect subtle information such as between‐individual variation.

Abstract Parasites can impact the behavior of animals and alter the interplay with ecological factors in their environment. Studying the effects that parasites have on animals thus requires accurate estimates of infections in individuals. However, quantifying parasites can be challenging due to several factors. Laboratory techniques, physiological fluctuations, methodological constraints, and environmental influences can introduce measurement errors, in particular when screening individuals in the wild. These issues are pervasive in ecological studies where it is common to sample study subjects only once. Such factors should be carefully considered when choosing a sampling strategy, yet presently there is little guidance covering the major sources of error. In this study, we estimate the reliability and sensitivity of different sampling practices at detecting two internal parasites—Serratospiculoides amaculata and Isospora sp.—in a model organism, the great tit Parus major. We combine field and captive sampling to assess whether individual parasite infection status and load can be estimated from single field samples, using different laboratory techniques—McMaster and mini‐FLOTAC. We test whether they vary in their performance, and quantify how sample processing affects parasite detection rates. We found that single field samples had elevated rates of false negatives. By contrast, samples collected from captivity over 24 h were highly reliable (few false negatives) and accurate (repeatable in the intensity of infection). In terms of methods, we found that the McMaster technique provided more repeatable estimates than the mini‐FLOTAC for S. amaculata eggs, and both techniques were largely equally suitable for Isospora oocysts. Our study shows that field samples are likely to be unreliable in accurately detecting the presence of parasites and, in particular, for estimating parasite loads in songbirds. We highlight important considerations for those designing host–parasite studies in captive or wild systems giving guidance that can help select suitable methods, minimize biases, and acknowledge possible limitations.

Abstract Marine reserves can protect fish populations by increasing abundance and body size, but less is known about the effect of protection on fish behaviour. We looked for individual consistency in movement behaviours of sea trout in the marine habitat using acoustic telemetry to investigate whether they represent personality traits and if so, do they affect survival in relation to protection offered by a marine reserve. Home range size had a repeatability of 0.21, suggesting that it represents a personality trait, while mean swimming depth, activity and diurnal vertical migration were not repeatable movement behaviours. The effect of home range size on survival differed depending on the proportion of time fish spent in the reserve, where individuals spending more time in the reserve experienced a decrease in survival with larger home ranges while individuals spending little time in the reserve experienced an increase in survival with larger home ranges. We suggest that the diversity of fish home range sizes could be preserved by establishing networks of marine reserves encompassing different habitat types, ensuring both a heterogeneity in environmental conditions and fishing pressure.

Abstract Hormones are extensively known to be physiological mediators of energy mobilization and allow animals to adjust behavioral performance in response to their environment, especially within a foraging context. Few studies, however, have narrowed focus toward the consistency of hormonal patterns and their impact on individual foraging behavior. Describing these relationships can further our understanding of how individuals cope with heterogeneous environments and exploit different ecological niches. To address this, we measured between‐ and within‐individual variation of basal cortisol (CORT), thyroid hormone T3, and testosterone (TEST) levels in wild adult female Galápagos sea lions (Zalophus wollebaeki) and analyzed how these hormones may be associated with foraging strategies. In this marine predator, females exhibit one of three spatially and temporally distinct foraging patterns (i.e., “benthic,” “pelagic,” and “night” divers) within diverse habitat types. Night divers differentiated from other strategies by having lower T3 levels. Considering metabolic costs, night divers may represent an energetically conservative strategy with shorter dive durations, depths, and descent rates to exploit prey which migrate up the water column based on vertical diel patterns. Intriguingly, CORT and TEST levels were highest in benthic divers, a strategy characterized by congregating around limited, shallow seafloors to specialize on confined yet reliable prey. This pattern may reflect hormone‐mediated behavioral responses to specific risks in these habitats, such as high competition with conspecifics, prey predictability, or greater risks of predation. Overall, our study highlights the collective effects of hormonal and ecological variation on marine foraging. In doing so, we provide insights into how mechanistic constraints and environmental pressures may facilitate individual specialization in adaptive behavior in wild populations.

Abstract Substantial variation in foraging strategies can exist within populations, even those typically regarded as generalists. Specializations arise from the consistent exploitation of a narrow behavioral, spatial or dietary niche over time, which may reduce intraspecific competition and influence adaptability to environmental change. However, few studies have investigated whether behavioral consistency confers benefits at the individual and/or population level. While still recovering from commercial sealing overexploitation, Australian fur seals (AUFS; Arctocephalus pusillus doriferus) represent the largest marine predator biomass in south‐eastern Australia. During lactation, female AUFS adopt a central‐place foraging strategy and are, thus, vulnerable to changes in prey availability. The present study investigated the population‐level repeatability and individual consistency in foraging behavior of 34 lactating female AUFS at a south‐east Australian breeding colony between 2006 and 2019. Additionally, the influence of individual‐level behavioral consistency on indices of foraging success and efficiency during benthic diving was determined. Low to moderate population‐level repeatability was observed across foraging behaviors, with the greatest repeatability in the mean bearing and modal dive depth. Individual‐level consistency was greatest for the proportion of benthic diving, total distance travelled, and trip duration. Indices of benthic foraging success and efficiency were positively influenced by consistency in the proportion of benthic diving, trip duration and dive rate but not influenced by consistency in bearing to most distal point, dive depth or foraging site fidelity. The results of the present study provide evidence of the benefits of consistency for individuals, which may have flow‐on effects at the population level.

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., (© 2024 International Society for Magnetic Resonance in Medicine.)

Abstract Measurement repeatability is often reported in morphometric studies as an index of the contribution of measurement error to trait measurements. However, the common method of remeasuring a mounted specimen fails to capture some components of measurement error and could therefore yield inflated repeatability estimates. Remounting specimens between successive measurements is likely to provide more realistic estimates of repeatability, particularly for structures that are difficult to measure. Using measurements of 22 somatic and genitalic traits of the neriid fly Telostylinus angusticollis, we compared repeatability estimates obtained via remeasurement of a specimen that is mounted once (single‐mounted method) versus remeasurement of a specimen that is remounted between measurements (remounted method). We also asked whether the difference in repeatability estimates obtained via the two methods depends on trait size, trait type (somatic vs. genitalic), sclerotization, or sex. Repeatability estimates obtained via the remounted method were lower than estimates obtained via the single‐mounted method for each of the 22 traits, and the difference between estimates obtained via the two methods was generally greater for small structures (such as genitalic traits) than for large structures (such as legs and wings). However, the difference between estimates obtained via the two methods did not depend on trait type (genitalic or somatic), tissue type (soft or sclerotized) or sex. Remounting specimens between successive measurements can provide more accurate estimates of measurement repeatability than remeasuring from a single mount, especially for small structures that are difficult to measure.

Abstract Morphometric research is being applied to a growing number and variety of organisms. Discoveries achieved via morphometric approaches are often considered highly transferable, in contrast to the tacit and idiosyncratic interpretation of discrete character states. The reliability of morphometric workflows in insect systematics has never been a subject of focused research, but such studies are sorely needed. In this paper, we assess the reproducibility of morphometric studies of ants where the mode of data collection is a shared routine. We compared datasets generated by eleven independent gaugers, that is, collaborators, who measured 21 continuous morphometric traits on the same pool of individuals according to the same protocol. The gaugers possessed a wide range of morphometric skills, had varying expertise among insect groups, and differed in their facility with measuring equipment. We used intraclass correlation coefficients (ICC) to calculate repeatability and reproducibility values (i.e., intra‐ and intergauger agreements), and we performed a multivariate permutational multivariate analysis of variance (PERMANOVA) using the Morosita index of dissimilarity with 9,999 iterations. The calculated average measure of intraclass correlation coefficients of different gaugers ranged from R = 0.784 to R = 0.9897 and a significant correlation was found between the repeatability and the morphometric skills of gaugers (p = 0.016). There was no significant association with the magnification of the equipment in the case of these rather small ants. The intergauger agreement, that is the reproducibility, varied between R = 0.872 and R = 0.471 (mean R = 0.690), but all gaugers arrived at the same two‐species conclusion. A PERMANOVA test revealed no significant gauger effect on species identity (R2 = 0.69, p = 0.58). Our findings show that morphometric studies are reproducible when observers follow the standard protocol; hence, morphometric findings are widely transferable and will remain a valuable data source for alpha taxonomy.

Abstract Consistent individual differences in behavior have been demonstrated for many animals, but there are few studies of consequences of such repeated behavior in the wild. We tested consistency in migration timing to and from the sea among anadromous Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta), using data from a study period of about 25 years, including more than 27,000 uniquely Carlin‐tagged individuals that migrated to sea for feeding in the spring and returned to the river in late summer for up to 13 successive years. Consistency was found between individuals across time in timing of the seaward migration. Individuals migrating early during their first migration tended to migrate early the following years, and late migrants tended to migrate late. The same pattern was found also at ascent to freshwater. Hence, this study demonstrated that individual fish in nature can differ in behavior related to migration timing and that these differences can be consistent during their lifetime. Early migrants increased their mass more than late migrants and had a higher specific growth rate. Early migrating Arctic char, but not brown trout, experienced a longer life after the first migration to sea than late migrants. In both species, maturity occurred earlier in individuals that migrated early. For brown trout, but not for Arctic char, fecundity was significantly correlated to the timing of smolt migration. Hence, the repeatable individual variation in migration timing seemed to have ecological and fitness consequences in terms of growth, longevity, timing of maturity, and lifetime fecundity.

Abstract Recent large‐scale projects in other disciplines have shown that results often fail to replicate when studies are repeated. The conditions contributing to this problem are also present in ecology, but there have not been any equivalent replication projects. Here, we survey ecologists' understanding of and opinions about replication studies. The majority of ecologists in our sample considered replication studies to be important (97%), not prevalent enough (91%), worth funding even given limited resources (61%), and suitable for publication in all journals (62%). However, there is a disconnect between this enthusiasm and the prevalence of direct replication studies in the literature which is much lower (0.023%: Kelly 2019) than our participants' median estimate of 10%. This may be explained by the obstacles our participants identified including the difficulty of conducting replication studies and of funding and publishing them. We conclude by offering suggestions for how replications could be better integrated into ecological research.

Abstract Investigating the drivers of diet quality is a key issue in wildlife ecology and conservation. Fecal near infrared reflectance spectroscopy (f‐NIRS) is widely used to assess dietary quality since it allows for noninvasive, rapid, and low‐cost analysis of nutrients. Samples for f‐NIRS can be collected and analyzed with or without knowledge of animal identities. While anonymous sampling allows to reduce the costs of individual identification, as it neither requires physical captures nor DNA genotyping, it neglects the potential effects of individual variation. As a consequence, regression models fitted to investigate the drivers of dietary quality may suffer severe issues of pseudoreplication. I investigated the relationship between crude protein and ecological predictors at different time periods to assess the level of individual heterogeneity in diet quality of 22 marked chamois Rupicapra rupicapra monitored over 2 years. Models with and without individual grouping effect were fitted to simulate identifiable and anonymous fecal sampling, and model estimates were compared to evaluate the consequences of anonymizing data collection and analysis. The variance explained by the individual random effect and the value of diet repeatability varied with seasons and peaked in winter. Despite the occurrence of individual variation in dietary quality, ecological parameter estimates under identifiable or anonymous sampling were consistently similar. This study suggests that anonymous fecal sampling may provide robust estimates of the relationship between dietary quality and ecological correlates. However, since the level of individual heterogeneity in dietary quality may vary with species‐ or study‐specific features, inconsequential pseudoreplication should not be assumed in other taxa. When individual differences are known to be inconsequential, anonymous sampling allows to optimize the trade‐off between sampling intensity and representativeness. When pseudoreplication is consequential, however, no conclusive remedy exists to effectively resolve nonindependence.

Purpose: To develop an open-source prototype of myocardial T1 mapping (Open-MOLLI) to improve accessibility to cardiac T1 mapping and evaluate its repeatability. With Open-MOLLI, we aim to enable faster implementation and testing of sequence modifications and to facilitate inter-scanner and cross-vendor reproducibility studies., Methods: Open-MOLLI is an inversion-recovery sequence using a balanced SSFP (bSSFP) readout, with inversion and triggering schemes based on the 5(3)3 MOLLI sequence, developed in Pulseq. Open-MOLLI and MOLLI sequences were acquired in the ISMRM/NIST phantom and 21 healthy volunteers. In 18 of those subjects, Open-MOLLI and MOLLI were repeated in the same session (test-retest)., Results: Phantom T1 values were comparable between methods, specifically for the vial with reference T1 value most similar to healthy myocardium T1 (T1 vial3  = 1027 ms): T1 MOLLI  = 1011 ± 24 ms versus T1 Open-MOLLI  = 1009 ± 20 ms. In vivo T1 estimates were similar between Open-MOLLI and MOLLI (T1 MOLLI  = 1004 ± 33 ms vs. T1 Open-MOLLI  = 998 ± 52 ms), with a mean difference of -17 ms (p = 0.20), despite noisier Open-MOLLI weighted images and maps. Repeatability measures were slightly higher for Open-MOLLI (RC MOLLI  = 3.0% vs. RC Open-MOLLI  = 4.4%)., Conclusion: The open-source sequence Open-MOLLI can be used for T1 mapping in vivo with similar mean T1 values to the MOLLI method. Open-MOLLI increases the accessibility to cardiac T1 mapping, providing also a base sequence to which further improvements can easily be added and tested., (© 2024 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Abstract Background Multi‐segment foot models (MFMs) for assessing three‐dimensional segmental foot motions are calculated via various analytical methods. Although validation studies have already been conducted, we cannot compare their results because the experimental environments in previous studies were different from each other. This study aims to compare the kinematics, repeatability, and reproducibility of five MFMs in the same experimental conditions. Methods Eleven healthy males with a mean age of 26.5 years participated in this study. We created a merged 29‐marker set including five MFMs: Oxford (OFM), modified Rizzoli (mRFM), DuPont (DFM), Milwaukee (MiFM), and modified Shriners Hospital for Children Greenville (mSHCG). Two operators applied the merged model to participants twice, and then we analysed two relative angles of three segments: shank‐hindfoot (HF) and hindfoot‐forefoot (FF). Coefficients of multiple correlation (CMC) and mean standard errors were used to assess repeatability and reproducibility, and statistical parametric mapping (SPM) of the t‐value was employed to compare kinematics. Results HF varus/valgus of the MiFM and mSHCG models, which rotated the segment according to radiographic or goniometric measurements during the reference frame construction, were significantly more repeatable and reproducible, compared to other models. They showed significantly more dorsiflexed HF and plantarflexed FF due to their static offset angles. DFM and mSHCG showed a greater range of motion (ROM), and some models had significantly different FF points of peak angle. Conclusions Under the same conditions, rotating the segment according to the appropriate offset angle obtained from radiographic or goniometric measurement increased reliability, but all MFMs had clinically acceptable reliability compared to previous studies. Moreover, in some models, especially HF varus/valgus, there were differences in ROM and points of peak angle even with no statistical difference in SPM curves. Therefore, based on the results of this study, clinicians and researchers involved in the evaluation of foot and ankle dysfunction need an understanding of the specific features of each MFM to make accurate decisions.

Abstract Objective Standardised quantitative analysis of the humoral immune response to SARS‐CoV‐2 antigens may be useful for estimating the extent and duration of immunity. The aim was to develop enzyme‐linked immunosorbent assays (ELISAs) for the quantification of human IgG antibodies against SARS‐CoV‐2 antigens. Methods Enzyme‐linked immunosorbent assays were developed based on monoclonal antibodies against human IgG and recombinant SARS‐CoV‐2 antigens (Spike‐S1 and Nucleocapsid). The WHO 67/086 immunoglobulin and WHO 20/136 SARS‐CoV‐2 references were used for standardisation. Sera of a study group of COVID‐19‐positive subjects (n = 144), pre‐pandemic controls (n = 135) and individuals vaccinated with BioNTech–Pfizer BNT162b2 vaccine (n = 48) were analysed. The study group sera were also tested using EuroImmun SARS‐CoV‐2‐ELISAs and a quantitative S1‐specific fluorescence enzyme immunoassay (FEIA) from Thermo Fisher. Results The ELISA results were repeatable and traceable to international units because of their parallelism to both WHO references. In the study group, median anti‐S1‐IgG concentrations were 102 BAU mL−1, compared to 100 and 1457 BAU mL−1 in the vaccination group after first and second vaccination, respectively. The ELISAs achieved an area under the curve (AUC) of 0.965 (S1) and 0.955 (Nucleocapsid) in receiver operating characteristic (ROC) analysis, and a specificity of 1 (S1) and 0.963 (Nucleocapsid) and sensitivity of 0.903 (S1) and 0.833 (Nucleocapsid) at the maximum Youden index. In comparison, the commercial assays (S1‐FEIA, S1 and Nucleocapsid ELISA EuroImmun) achieved sensitivities of 0.764, 0.875 and 0.882 in the study group, respectively. Conclusions The quantitative ELISAs to measure IgG binding to SARS‐CoV‐2 antigens have good analytical and clinical performance characteristics and units traceable to international standards.

Abstract Background Foot and ankle joint kinematics are measured during clinical gait analyses with marker‐based multi‐segment foot models. To improve on existing models, measurement errors due to soft tissue artifacts (STAs) and marker misplacements should be reduced. Therefore, the aim of this study is to define a clinically informed, universally applicable multi‐segment foot model, which is developed to minimize these measurement errors. Methods The Amsterdam foot model (AFM) is a follow‐up of existing multi‐segment foot models. It was developed by consulting a clinical expert panel and optimizing marker locations and segment definitions to minimize measurement errors. Evaluation of the model was performed in three steps. First, kinematic errors due to STAs were evaluated and compared to two frequently used foot models, i.e. the Oxford and Rizzoli foot models (OFM, RFM). Previously collected computed tomography data was used of 15 asymptomatic feet with markers attached, to determine the joint angles with and without STAs taken into account. Second, the sensitivity to marker misplacements was determined for AFM and compared to OFM and RFM using static standing trials of 19 asymptomatic subjects in which each marker was virtually replaced in multiple directions. Third, a preliminary inter‐ and intra‐tester repeatability analysis was performed by acquiring 3D gait analysis data of 15 healthy subjects, who were equipped by two testers for two sessions. Repeatability of all kinematic parameters was assessed through analysis of the standard deviation (σ) and standard error of measurement (SEM). Results The AFM was defined and all calculation methods were provided. Errors in joint angles due to STAs were in general similar or smaller in AFM (≤2.9°) compared to OFM (≤4.0°) and RFM (≤6.7°). AFM was also more robust to marker misplacement than OFM and RFM, as a large sensitivity of kinematic parameters to marker misplacement (i.e. > 1.0°/mm) was found only two times for AFM as opposed to six times for OFM and five times for RFM. The average intra‐tester repeatability of AFM angles was σ:2.2[0.9°], SEM:3.3 ± 0.9° and the inter‐tester repeatability was σ:3.1[2.1°], SEM:5.2 ± 2.3°. Conclusions Measurement errors of AFM are smaller compared to two widely‐used multi‐segment foot models. This qualifies AFM as a follow‐up to existing foot models, which should be evaluated further in a range of clinical application areas.

Abstract Background The ankle brachial index (ABI) is widely used in clinical practice as a non-invasive method to detect the presence and severity of peripheral arterial disease (PAD). Current guidelines suggest that it should be used to monitor potential progression of PAD in affected individuals. As such, it is important that the test is reliable when used for repeated measurements, by the same or different health practitioners. This systematic review aims to examine the literature to evaluate the inter- and intra-rater reliability of the ABI. Methods A systematic search of MEDLINE, EMBASE and CINAHL Complete was conducted to 20 January 2019. Two authors independently reviewed and selected relevant studies and extracted the data. Methodological quality was determined using the Quality Appraisal of Reliability (QAREL) Checklist. Results Fifteen studies of ABI reliability in a range of patient populations were identified as suitable for inclusion in the review: seven considered inter-rater reliability, four intra-rater reliability, and four studies evaluated both inter- and intra-rater reliability. Inter-rater reliability was found to be highly variable, with intraclass correlation coefficients (ICC’s) ranging from poor to excellent (ICC 0.42–1.00), while intra-rater also demonstrated considerable variation, with ICCs from 0.42–0.98. Meta-analysis was not possible due to the lack of statistical information reported. Conclusions Results of included studies suggest the inter- and intra-tester reliability of the ABI is acceptable. However, inconsistencies in obtaining systolic pressure measurements, calculating ABI values, and incomplete reporting of methodologies and statistical analysis make it difficult to determine the validity of the results of included studies. Further research, with more consistent reliability methodology, statistical analysis and reporting conducted in populations at risk of PAD is needed to conclusively determine the ABI reliability.

ABSTRACT We compared methods commonly used in the field of river otter (Lontra canadensis) ecology to estimate visitation rates. We evaluated visitation rates estimated from 2 survey protocols based on video detection—individual visitation rate (IVR) and recording visitation rate (RVR)—and one indirect method based on scat detection—scat visitation rate (SVR). From August 2011 through August 2012, overall scat detection and cumulative video data from 403 camera‐days in 2 latrine sites (River and Pond, at a study site adjacent to the Salt Fork of the Vermilion River near Fairmount, Illinois, USA) located

Abstract Background Electrocardiographic left ventricular hypertrophy (ECG‐LVH) represents preclinical cardiovascular disease and predicts cardiovascular disease morbidity and mortality. While the newly developed Peguero‐Lo Presti ECG‐LVH criteria have greater sensitivity for LVH than the Cornell voltage and Sokolow–Lyon criteria, its short‐term repeatability is unknown. Therefore, we characterized the short‐term repeatability of Peguero‐Lo Presti ECG‐LVH criteria and evaluate its agreement with Cornell voltage and Sokolow–Lyon ECG‐LVH criteria. Methods Participants underwent two resting, standard, 12‐lead ECGs at each of two visits one week apart (n = 63). We defined a Peguero‐Lo Presti index as a sum of the deepest S wave amplitude in any single lead and lead V4 (i.e., SD + SV4) and defined Peguero‐Lo Presti LVH index as ≥ 2,300 µV among women and ≥ 2,800 µV among men. We estimated repeatability as an intraclass correlation coefficient (ICC), agreement as a prevalence‐adjusted bias‐adjusted kappa coefficient (κ), and precision using 95% confidence intervals (CIs). Results The Peguero‐Lo Presti index was repeatable: ICC (95% CI) = 0.94 (0.91–0.97). Within‐visit agreement of Peguero‐Lo Presti LVH was high at the first and second visits: κ (95% CI) = 0.97 (0.91–1.00) and 1.00 (1.00–1.00). Between‐visit agreement of the first and second measurements at each visit was comparable: κ (95% CI) = 0.90 (0.80–1.00) and 0.93 (0.85–1.00). Agreement of Peguero‐Lo Presti and Cornell or Sokolow–Lyon LVH on any one of the four ECGs was slightly lower: κ (95% CI) = 0.71 (0.54–0.89). Conclusion The Peguero‐Lo Presti index and LVH have excellent repeatability and agreement, which support their use in clinical and epidemiological studies.

Purpose: Quantitative MRI techniques such as MR fingerprinting (MRF) promise more objective and comparable measurements of tissue properties at the point-of-care than weighted imaging. However, few direct cross-modal comparisons of MRF's repeatability and reproducibility versus weighted acquisitions have been performed. This work proposes a novel fully automated pipeline for quantitatively comparing cross-modal imaging performance in vivo via atlas-based sampling., Methods: We acquire whole-brain 3D-MRF, turbo spin echo, and MPRAGE sequences three times each on two scanners across 10 subjects, for a total of 60 multimodal datasets. The proposed automated registration and analysis pipeline uses linear and nonlinear registration to align all qualitative and quantitative DICOM stacks to Montreal Neurological Institute (MNI) 152 space, then samples each dataset's native space through transformation inversion to compare performance within atlas regions across subjects, scanners, and repetitions., Results: Voxel values within MRF-derived maps were found to be more repeatable (σ T1  = 1.90, σ T2  = 3.20) across sessions than vendor-reconstructed MPRAGE (σ T1w  = 6.04) or turbo spin echo (σ T2w  = 5.66) images. Additionally, MRF was found to be more reproducible across scanners (σ T1  = 2.21, σ T2  = 3.89) than either qualitative modality (σ T1w  = 7.84, σ T2w  = 7.76). Notably, differences between repeatability and reproducibility of in vivo MRF were insignificant, unlike the weighted images., Conclusion: MRF data from many sessions and scanners can potentially be treated as a single dataset for harmonized analysis or longitudinal comparisons without the additional regularization steps needed for qualitative modalities., (© 2024 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Abstract Learning ecology requires training in data management and analysis. Because of its transparent and flexible nature, R is increasingly used for data management and analysis in the field of ecology. Consequently, job postings targeting candidates with a bachelor's degree and a required knowledge of R have increased over the past ten years. In this paper, we begin by presenting data from the last ten years demonstrating the increase in the use of R, an open‐source programming environment, in ecology and its prevalence as a required skill in job descriptions. We then discuss our experiences teaching undergraduates R in two advanced ecology classes using different approaches. One approach, in a course with a field laboratory, focused on collecting, cleaning, and preparing data for analysis. The other approach, in a course without a field laboratory, focused on analyzing existing datasets and applying the results to content discussed in the lecture portion of the course. Our experiences determined that each approach had strengths and weaknesses. We recommend that above all, instructors of ecology and related subjects should be encouraged to include R in their coursework. Furthermore, instructors should be aware of the following: Learning R is a separate skill from learning statistics; writing R assignments is a significant time commitment for course preparation; and there is a tradeoff between teaching R and teaching content. Determining how one's course fits into the curriculum and identifying resources outside of the classroom for students’ continued practice will ensure that R training is successful and will extend beyond a one‐semester course.

Abstract Background Changes in muscle fat composition as for example observed in sarcopenia or muscular dystrophy affect physical performance and muscular function, like strength and power. The purpose of the present study is to measure the repeatability of Dixon magnetic resonance imaging (MRI) for assessing muscle volume and fat in the thigh. Furthermore, repeatability of magnetic resonance spectroscopy (MRS) for assessing muscle fat is determined. Methods A prototype 6‐point Dixon MRI method was used to measure muscle volume and muscle proton density fat fraction (PDFF) in the left thigh. PDFF was measured in musculus semitendinosus of the left thigh with a T2‐corrected multi‐echo MRS method. For the determination of short‐term repeatability (consecutive examinations), the root mean square coefficients of variation of Dixon MRI and MRS data of 23 young and healthy (29 ± 5 years) and 24 elderly men with sarcopenia (78 ± 5 years) were calculated. For the estimation of the long‐term repeatability (13 weeks between examinations), the root mean square coefficients of variation of MRI data of seven young and healthy (31 ± 7 years) and 23 elderly sarcopenic men (76 ± 5 years) were calculated. Long‐term repeatability of MRS was not determined. Results Short‐term errors of Dixon MRI volume measurement were between 1.2% and 1.5%, between 2.1% and 1.6% for Dixon MRI PDFF measurement, and between 9.0% and 15.3% for MRS. Because of the high short‐term repeatability errors of MRS, long‐term errors were not determined. Long‐term errors of MRI volume measurement were between 1.9% and 4.0% and of Dixon MRI PDFF measurement between 2.1% and 4.2%. Conclusions The high degree of repeatability of volume and PDFF Dixon MRI supports its use to predict future mobility impairment and measures the success of therapeutic interventions, for example, in sarcopenia in aging populations and muscular dystrophy. Because of possible inhomogeneity of fat infiltration in muscle tissue, the application of MRS for PDFF measurements in muscle is more problematic because this may result in high repeatability errors. In addition, the tissue composition within the MRS voxel may not be representative for the whole muscle.

Abstract In the animal kingdom, behavioral variation among individuals has often been reported. However, stable among‐individual differences along a behavioral continuum—reflective of personality variation—have only recently become a key target of research. While a vast body of descriptive literature exists on animal personality, hypothesis‐driven quantitative studies are largely deficient. One of the main constraints to advance the field is the lack of suitable model organisms. Here, we explore whether N. furzeri could be a valuable model to bridge descriptive and hypothesis‐driven research to further unravel the causes, function and evolution of animal personality. As a first step toward this end, we perform a common garden laboratory experiment to examine if behavioral variation in the turquoise killifish Nothobranchius furzeri reflects personality divergence. Furthermore, we explore if multiple behavioral traits are correlated. We deliver “proof of principle” of personality variation among N. furzeri individuals in multiple behavioral traits. Because of the vast body of available genomic and physiological information, the well‐characterized ecological background and an exceptionally short life cycle, N. furzeri is an excellent model organism to further elucidate the causes and implications of behavioral variation in an eco‐evolutionary context.

Abstract Background The Footscan® platform system is one of the most commonly used clinical tools for the measurement of the foot pressure. The present study was designed to assess the repeatability of the system and identify the range of loading parameters observed in the normal foot. Methods Measurements were collected from 32 healthy participants, 15 females and 17 males, twice at an interval of 1 week. Peak pressure (PP), contact time (CT), contact area (CA), pressure-time integral (PTI), and maximum force (MaF) were recorded; these parameters were investigated in 10 areas of the foot: medial heel, lateral heel, midfoot, first to fifth metatarsals, hallux, and toes 2–5. The intra-session repeatability was evaluated by calculating the intraclass correlation coefficients (ICCs) and coefficients of variation (CVs) across the three repeated trials within the same session. The inter-session repeatability was assessed using the average of the three trials in each session to determine the ICCs and CVs. Results The ICCs showed moderate to good repeatability for every variable of interest, and the CVs were all

Abstract Background Forefoot structure is important to understand some foot problems such as hallux valgus and metatarsalgia. Ultrasonography (US) is a highly portable, noninvasive, low cost, and fast imaging method, especially when compared to magnetic resonance imaging (MRI), computed tomography (CT), and radiography. As the use of US for evaluating forefoot bony structure has not been validated, except for the presence of synovitis, erosions and bursitis within the forefoot in people with inflammatory arthritis, the purpose of this study was to determine whether US is a reliable method for evaluating forefoot structure. Methods Sixty feet (30 women, age = 40.1 ± 11.8 years) were examined by US and CT to assess agreement with CT and repeatability of US evaluation of the 2nd metatarsal head height, length between the medial sesamoid bone and 5th metatarsal head, transverse arch height, transverse arch index, sesamoid rotation angle, and area under the transverse arch. The measurement data were evaluated for agreement with CT using the intra-class correlation coefficient (ICC)3, 1, Pearson correlation coefficient, and Bland-Altman plot, and with ICC1, 1 for repeatability. Results The ICC3, 1 values of 0.78–0.89, Pearson correlation coefficient of 0.78–0.90, and Bland-Altman plots showed almost perfect agreements between the US and CT method for all parameters, except the area under the transverse arch (AUTA). The ICC1, 1 also showed perfect agreements (0.84–0.92) between two sets of US measurements in all parameters. Conclusions The US evaluation of forefoot structure in the coronal plane showed good agreement with CT and repeatability of two ultrasonograms in adult women. This reliable evaluation method of forefoot structure can contribute to a quick clinical assessment screening for risk factors of foot problems such as hallux valgus and metatarsalgia. However, because of some limitations such as a lack of inter-observer reliability, more research is needed to validate US evaluation of forefoot structure. Trial registration The current study (trial registration number: R0297) was approved by the Ethical Committee for Human Experiments of Kyoto University ( http://www.ec.med.kyoto-u.ac.jp ) on December 3, 2015. The first participant in this study was enrolled on November 17, 2015 and retrospectively registered.

The expanding field of extracellular vesicle (EV) research needs reproducible and accurate methods to characterize single EVs. Nanoparticle Tracking Analysis (NTA) is commonly used to determine EV concentration and diameter. As the EV field is lacking methods to easily confirm and validate NTA data, questioning the reliability of measurements remains highly important. In this regard, a comparison addressing measurement quality between different NTA devices such as Malvern’s NanoSight NS300 or Particle Metrix’ ZetaView has not yet been conducted. To evaluate the accuracy and repeatability of size and concentration determinations of both devices, we employed comparative methods including transmission electron microscopy (TEM) and single particle interferometric reflectance imaging sensing (SP-IRIS) by ExoView. Multiple test measurements with nanospheres, liposomes and ultracentrifuged EVs from human serum and cell culture supernatant were performed. Additionally, serial dilutions and freeze-thaw cycle-dependent EV decrease were measured to determine the robustness of each system. Strikingly, NanoSight NS300 exhibited a 2.0–2.1-fold overestimation of polystyrene and silica nanosphere concentration. By measuring serial dilutions of EV samples, we demonstrated higher accuracy in concentration determination by ZetaView (% BIAS range: 2.7–8.5) in comparison with NanoSight NS300 (% BIAS range: 32.9–36.8). The concentration measurements by ZetaView were also more precise (% CV range: 0.0–4.7) than measurements by NanoSight NS300 (% CV range: 5.4–10.7). On the contrary, quantitative TEM imaging indicated more accurate EV sizing by NanoSight NS300 (% DTEM range: 79.5–134.3) compared to ZetaView (% DTEM range: 111.8–205.7), while being equally repeatable (NanoSight NS300% CV range: 0.8–6.7; ZetaView: 1.4–7.8). However, both devices failed to report a peak EV diameter below 60 nm compared to TEM and SP-IRIS. Taken together, NTA devices differ strongly in their hardware and software affecting measuring results. ZetaView provided a more accurate and repeatable depiction of EV concentration, whereas NanoSight NS300 supplied size measurements of higher resolution.

Purpose: Dynamic lung oxygen-enhanced MRI (OE-MRI) is challenging due to the presence of confounding signals and poor signal-to-noise ratio, particularly at 3 T. We have created a robust pipeline utilizing independent component analysis (ICA) to automatically extract the oxygen-induced signal change from confounding factors to improve the accuracy and sensitivity of lung OE-MRI., Methods: Dynamic OE-MRI was performed on healthy participants using a dual-echo multi-slice spoiled gradient echo sequence at 3 T and cyclical gas delivery. ICA was applied to each echo within a thoracic mask. The ICA component relating to the oxygen-enhancement signal was automatically identified using correlation analysis. The oxygen-enhancement component was reconstructed, and the percentage signal enhancement (PSE) was calculated. The lung PSE of current smokers was compared with nonsmokers; scan-rescan repeatability, ICA pipeline repeatability, and reproducibility between two vendors were assessed., Results: ICA successfully extracted a consistent oxygen-enhancement component for all participants. Lung tissue and oxygenated blood displayed the opposite oxygen-induced signal enhancements. A significant difference in PSE was observed between the lungs of current smokers and nonsmokers. The scan-rescan repeatability and the ICA pipeline repeatability were good., Conclusion: The developed pipeline demonstrated sensitivity to the signal enhancements of the lung tissue and oxygenated blood at 3 T. The difference in lung PSE between current smokers and nonsmokers indicates a likely sensitivity to lung function alterations that may be seen in mild pathology, supporting future use of our methods in patient studies., (© 2023 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Purpose: To demonstrate proof-of-concept of a T 2 *-sensitized oxygen-enhanced MRI (OE-MRI) method at 3T by assessing signal characteristics, repeatability, and reproducibility of dynamic lung OE-MRI metrics in healthy volunteers., Methods: We performed sequence-specific simulations for protocol optimisation and acquired free-breathing OE-MRI data from 16 healthy subjects using a dual-echo RF-spoiled gradient echo approach at 3T across two institutions. Non-linear registration and tissue density correction were applied. Derived metrics included percent signal enhancement (PSE), ∆R 2 * and wash-in time normalized for breathing rate (τ-nBR). Inter-scanner reproducibility and intra-scanner repeatability were evaluated using intra-class correlation coefficient (ICC), repeatability coefficient, reproducibility coefficient, and Bland-Altman analysis., Results: Simulations and experimental data show negative contrast upon oxygen inhalation, due to substantial dominance of ∆R 2 * at TE > 0.2 ms. Density correction improved signal fluctuations. Density-corrected mean PSE values, aligned with simulations, display TE-dependence, and an anterior-to-posterior PSE reduction trend at TE 1 . ∆R 2 * maps exhibit spatial heterogeneity in oxygen delivery, featuring anterior-to-posterior R 2 * increase. Mean T 2 * values across 32 scans were 0.68 and 0.62 ms for pre- and post-O 2 inhalation, respectively. Excellent or good agreement emerged from all intra-, inter-scanner and inter-rater variability tests for PSE and ∆R 2 *. However, ICC values for τ-nBR demonstrated limited agreement between repeated measures., Conclusion: Our results demonstrate the feasibility of a T 2 *-weighted method utilizing a dual-echo RF-spoiled gradient echo approach, simultaneously capturing PSE, ∆R 2 * changes, and oxygen wash-in during free-breathing. The excellent or good repeatability and reproducibility on intra- and inter-scanner PSE and ∆R 2 * suggest potential utility in multi-center clinical applications., (© 2023 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)