Coefficient Of Variation Scores Research Articles

Association between mealtime distribution of macronutrient and mental health in apparently healthy Iranian adults: a cross-sectional study

ABSTRACT Mental health (MH) disorders are one of the most prevalent global public health issues for a significant portion of the population. The aim of this study was to investigate the relationship between the mealtime distribution of macronutrients and MH in Iranian adults. We used a convenience sampling technique to perform this cross-sectional study. The Depression, Anxiety, and Stress Scale (DASS-21) was used to assess the MH outcome. Dietary consumption was assessed using multiple 24-hour dietary recalls. The coefficient of variation (CV) was then used to compute the macronutrient distribution at mealtime. In all, 54.6%, 53.9%, and 56.6% were classified as having anxiety, depression, and stress symptoms, respectively. The CV scores for carbohydrate were relatively evenly distributed across all meal times, with a mean of 0.38, 0.38, and 0.39 for breakfast, lunch, and dinner, respectively. We observed no significant association between the mealtime distribution of carbohydrates and mental health indices in any of the analyzed models. However, a more skewed distribution of protein intake towards dinner (i.e. a higher protein CV value) was positively associated with anxiety (OR: 1.69; CI: 1.02-2.78) and stress symptoms (OR: 1.93; CI: 1.17-3.16). We also observed a significant association between fat distribution and depression symptoms, with subjects in tertile 2 having higher odds of depression compared to T1 (OR: 1.63; CI: 1.00-2.63). In conclusion, a skewed distribution of protein and fat intake may be associated with mental health problems. Future studies are warranted to validate these findings and gain a better understanding of the underlying mechanisms.

Spatial analysis with unoccupied aircraft systems data in wheat breeding yield trials

AbstractAn important aspect of reliable cultivar development is good field trial evaluations. Unoccupied aircraft systems (UAS also known as drones or UAVs) are a popular high‐throughput phenotyping tool that has been used to successfully evaluate plant stress and other canopy characteristics in a field. In precision agriculture applications, UAS imagery has been used to identify spatial variability in field settings. Here, we use UAS spectral imagery to improve field trial spatial analysis, better control spatial variability, and reduce errors for more reliable selections. UAS imagery data were collected across 47 breeding trials planted in an augmented complete block design (ACBD) or alpha‐lattice replicated designs from 2020 through 2023. Trials were evaluated using three spatial analysis strategies: linear models incorporating block effect, row‐column effect, or 2D splines. UAS‐derived spectral reflectance indices (SRI) were combined with each model as covariates. Modeling strategies were used across all trials and evaluated for autocorrelation, model fitness, and coefficient of variation (CV). Akaike information criterion (AIC) was used to assess model fitness. For spatial analysis trials, SRIs significantly lowered model AIC by an average of 38.4 for alpha‐lattice trials and 69.1 for ACBD trials. CV scores were also lowered when SRIs were utilized, with average CV values being 2.6 lower for alpha‐lattice and 2.1 for ACBD trials. This study highlights the potential for SRIs to improve the analyses of field breeding trials despite extreme environmental variables and climate conditions, improving experiment reliability and changing the way breeders plan and implement breeding experiments.

Intrasubject variability of sustained attention is associated with elevated self-reported attention deficits in women with a fragile X premutation allele.

Women with a fragile X premutation (PM) self-report higher rates of attention difficulties than women without a PM; however, results of studies using objective measures of attention are inconsistent. The present study assessed whether intrasubject variability during a sustained attention task better predicted functional outcomes in women with a PM than the previously published standard reaction time and accuracy variables. We analyzed continuous performance test, a computerized measure of sustained attention, and the Conners' Adult Attention-Deficit/Hyperactivity Disorder Rating Scale Report (CAARS) data from 273 women with a PM and 175 women without a PM aged 18-50 years. Separate analyses using Pearson correlations and independent t tests were performed on the full range of coefficient of variation (CV) of reaction time scores and the subset of scores that showed higher variability. Performance variability of sustained attention measured by the continuous performance test was associated with functional outcomes measured by the CAARS in women with a PM but not women without a PM. Specifically, the CV in those with higher variability was correlated with two CAARS subscale scores (p = .006). Independent t tests showed significant differences in CV between CAARS scores dichotomized for the presence of subclinical symptoms for two subscales (p ≤ .001-.007). Correlation between the full range of CV scores and the CAARS Inattention/Memory Problems subscale approached significance (p = .012). Findings highlight the importance of including intrasubject variability in analyzing attention in clinical populations as a more sensitive objective measure associated with reported symptoms and to assist in predicting functional outcomes. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Eye Movement Latency Coefficient of Variation as a Predictor of Cognitive Impairment: An Eye Tracking Study of Cognitive Impairment.

Studies demonstrated impairment in the control of saccadic eye movements in Alzheimer's disease (AD) and people with mild cognitive impairment (MCI) when conducting the pro-saccade and antisaccade tasks. Research showed that changes in the pro and antisaccade latencies may be particularly sensitive to dementia and general executive functioning. These tasks show potential for diagnostic use, as they provide a rich set of potential eye tracking markers. One such marker, the coefficient of variation (CV), is so far overlooked. For biological markers to be reliable, they must be able to detect abnormalities in preclinical stages. MCI is often viewed as a predecessor to AD, with certain classifications of MCI more likely than others to progress to AD. The current study examined the potential of CV scores on pro and antisaccade tasks to distinguish participants with AD, amnestic MCI (aMCI), non-amnesiac MCI (naMCI), and older controls. The analyses revealed no significant differences in CV scores across the groups using the pro or antisaccade task. Antisaccade mean latencies were able to distinguish participants with AD and the MCI subgroups. Future research is needed on CV measures and attentional fluctuations in AD and MCI individuals to fully assess this measure's potential to robustly distinguish clinical groups with high sensitivity and specificity.

Testing the Validity of CV for Single-Plant Yield in the Absence of Competition as a Homeostasis Index

The coefficient of variation (CV) of yield may functionally be related to the mean. The expected exponential CV decline with increasing mean, i.e., the Taylor’s power law (TPL), is not always valid. Removal of this scale dependency allows for a scale-independent assessment of stability. The objective of this study was to interpret the validity of the homeostasis index (HI), i.e., the inverse CV value, suggested in breeding under nil competition as a selection criterion for progeny lines that oppose the acquired interplant variation. Data concerning the single-plant yield of various crops under a nil-competition regime were studies against the theoretical background of the above hypothesis. Simple correlations between logarithms of variances and respective means were used to assess the reliability of CV as a stability statistic in breeding trials under nil competition. A total of 8 of the 24 case analyses revealed a systematic variance dependence on the mean. The impact was more prevalent in experiments with extensive spatial heterogeneity and high CV scores. Conversion of variance to remove systematic dependence did not validate the CV~mean negative relationship. Because of variance dependence, caution is needed when interpreting the HI as a stability index. Misuse of the HI may entail the risk of bias, upgrading or downgrading a progeny line in its ability to withstand acquired dissimilarity between plants. Testing the validity of the variance seems necessary, and the calculation of HI on a converted variance may enhance the accuracy of identifying the most promising progeny lines.

Exploring Force Production Reliability across Different Levels of Clinical Experience during a Simulated One-handed Instrument-Assisted Soft Tissue Mobilization Treatment: A Pilot Study.

BackgroundInstrument-assisted soft tissue mobilization (IASTM) is a commonly utilized intervention for musculoskeletal pain and dysfunction. However, little is known regarding the reliability of forces applied by clinicians of different experience levels during an IASTM intervention.PurposeThe purpose of this pilot study was to assess intra-clinician reliability of IASTM force (i.e., mean normal force) during a simulated, one-handed stroke IASTM intervention across different levels of IASTM clinical experience.DesignDescriptive laboratory study.MethodsThe researchers conducted a repeated measures trial in a laboratory setting with a convenience sample of ten participants who had previously completed professional IASTM training. Participants performed 15 one-handed sweeping strokes with an IASTM instrument on a skin simulant attached to a force plate for a standardized hypothetical treatment scenario. The participants performed the treatment on two separate days, 24-48 hours apart. The researchers examined the intra-rater reliability for average (mean) normal forces using Bland-Altman (BA) plots and Coefficient of Variation (CV) values.ResultsThe BA plot results indicated all participants (professional athletic training students = 4, athletic trainers = 6; males = 5, females = 5; age = 32.60 ± 8.71 y; IASTM experience = 3.78 ± 4.10 y), except participant D (1.9N, 190g), were consistently reliable within 1N (100g) or less of force for mean differences and within the maximum limits of agreement around 3.7N (370g). Most participants’ CV scores ranged between 8 to 20% supporting reliable force application within each treatment session.ConclusionThe data indicated that IASTM trained clinicians could produce consistent forces within and across treatment sessions irrespective of clinical experience.Level of Evidence3

Using Thermal Imaging to Monitor Body Temperature of Koalas (Phascolarctos cinereus) in A Zoo Setting.

Simple SummaryBody temperature regulation is integral for the health and well-being of animals, especially in Zoo settings. Endothermic vertebrates such as small mammals are able to maintain a constant internal body temperature; however, extreme variation in body temperature may be reflective of underlying injuries or health issues. Thus, new technology that can enable the measurement of body temperature of small mammals without need for capture and handling can be very useful for the monitoring of animals in Zoos. In this study, we report the application of an IR thermal imaging camera for monitoring the body temperature of koalas. We found that the eye and abdomen were the most consistent body features to record body temperature. This tool will have useful application for welfare evaluation of small mammals, such as koalas in Zoos.Non-invasive techniques can be applied for monitoring the physiology and behaviour of wildlife in Zoos to improve management and welfare. Thermal imaging technology has been used as a non-invasive technique to measure the body temperature of various domesticated and wildlife species. In this study, we evaluated the application of thermal imaging to measure the body temperature of koalas (Phascolarctos cinereus) in a Zoo environment. The aim of the study was to determine the body feature most suitable for recording a koala’s body temperature (using coefficient of variation scores). We used a FLIR530TM IR thermal imaging camera to take images of each individual koala across three days in autumn 2018 at the Wildlife Sydney Zoo, Australia. Our results demonstrated that koalas had more than one reliable body feature for recording body temperature using the thermal imaging tool—the most reliable features were eyes and abdomen. This study provides first reported application of thermal imaging on an Australian native species in a Zoo and demonstrates its potential applicability as a humane/non-invasive technique for assessing the body temperature as an index of stress.

Force and Directional Force Modulation Effects on Accuracy and Variability in Low-Level Pinch Force Tracking

ABSTRACTThe authors investigated how varying the required low-level forces and the direction of force change affect accuracy and variability of force production in a cyclic isometric pinch force tracking task. Eighteen healthy right-handed adult volunteers performed the tracking task over 3 different force ranges. Root mean square error and coefficient of variation were higher at lower force levels and during minimum reversals compared with maximum reversals. Overall, the thumb showed greater root mean square error and coefficient of variation scores than did the index finger during maximum reversals, but not during minimum reversals. The observed impaired performance during minimum reversals might originate from history-dependent mechanisms of force production and highly coupled 2-digit performance.

Using a Delphi process to determine optimal care for patients with pancreatic cancer.

Overall 5-year survival for pancreatic cancer is ∼5%. Optimizing the care that pancreatic cancer patients receive may be one way of improving outcomes. The objective of this study was to establish components of care which Australian health professionals believe important to optimally manage patients with pancreatic cancer. Using a Delphi process, a multidisciplinary panel of 250 health professionals were invited to provide a list of factors they considered important for optimal care of pancreatic cancer patients. They were then asked to score and then rescore (from one [no importance/disagree] to 10 [very important/agree]) the factors. The mean and coefficient of variation scores were calculated and categorized into three levels of importance. Overall, 63 (66% of those sent the final questionnaire; 25% of those initially invited) health professionals from nine disciplines completed the final scoring of 55 statements/factors encompassing themes of presentation/staging, surgery and biliary obstruction, multidisciplinary team details and oncology. Mean scores ranged from 3.7 to 9.7 with the highest related to communication and patient assessment. There was substantial intra- and interdisciplinary variation in views about MDT membership and roles. Overall, the opinions of Australian health professionals reflect international guideline recommended care; however, they identified a number of additional factors focusing on where patients should be treated, the importance of clear communication and the need for multidisciplinary care which were not included in current clinical practice guidelines. Differences in priorities between specialty groups were also identified.

Post-fire succession indices performance in a Mediterranean ecosystem

We sought to quantify early species succession (covering a 9 year period) after a natural wildfire in an unmanaged Mediterranean-type ecosystem across three different soil types. We examined different indices that are frequently used in literature as for their sensitivity and ability in tracing vegetation changes during a post-fire succession. Field data from a forest in Sithonia peninsula, northern Greece, during a period of 10 years after a fire event were used as a case study. In order to detect the best model fit of diversity and evenness indices we used pseudovalues generated with the jackknife method. The index of evenness and diversity with the lowest coefficient of variation scores were selected as the ones with the best model fit. In order to select the abundance model with the best model fit we compared the difference of the observed abundances data from the jackknife-predicted ones using the Akaike information criterion. According to our results, in rich and medium soil types, the best diversity ecosystem index from the ones examined was the (inverse) Berger–Parker one, while in poor soil types the Simpson or Brillouin diversity index. According to our results, in rich and medium soil type Mediterranean ecosystems, a good biodiversity ecosystem descriptor is based on how abundant is the most abundant species. In poor soil types where there are fewer species, and the percentage of cover is lower, indices that account for the relative representation of species within the community structure are better biodiversity ecosystem descriptors. All evenness indices examined but the Smith–Wilson were good ecosystem descriptors. The abundance model that showed the best model fit was the log series one. The poor fit of the Smith–Wilson’s index suggests that in species poor ecosystems the number of species is more important than species variance.

Reproducibility of the time to peak torque and the joint angle at peak torque on knee of young sportsmen on the isokinetic dynamometer

BackgroundAlthough peak torque has shown acceptable reproducibility, this may not be the case with two other often used parameters: time to peak torque (TPT) and the angle of peak torque (APT). Those two parameters should be used for the characterization of muscular adaptations in athletes. MethodsThe isokinetic performance of the knee extensors and flexors in both limbs was measured in 29 male athletes. The experimental protocol consisted of three consecutive identical paradigms separated by 45min breaks. Each test consisted of four maximal concentric efforts performed at 60 and 180°/s. Reproducibility was quantified by the standard error measurement (SEM), the coefficient of variation (CV) and by means of intra-class correlation coefficients (ICCs) with the calculation of 6 forms of ICCs. ResultsUsing ICC as the indicator of reproducibility, the correlations for TPT of both limbs showed a range of 0.51–0.65 in extension and 0.50–0.63 in flexion. For APT, the values were 0.46–0.60 and 0.51–0.81, respectively. In addition, the calculated standard error of measurement (SEM) and CV scores confirmed the low level of absolute reproducibility. ConclusionsDue to their low reproducibility, neither TPT nor APT can serve as independent isokinetic parameters of knee flexor and extensor performance. So, given its reproducibility level, TPT and APT should not be used for the characterization of muscular adaptations in athletes.

Measurement variability and sincerity of effort: clinical utility of isokinetic strength coefficient of variation scores

Although the use of measures of strength variability as a means of judging sincerity of effort is becoming common practice, the accuracy of doing so has been questioned. Coefficient of variation (CV) cut-off points, indicating the upper limit of variability for repeated maximal efforts, are routinely used to identify workers providing submaximal efforts during various strength tests. However, the stability of the CV itself has not been considered when comparing an individual's observed CV score to these cut-off points. The purpose of the present study was to examine the day-to-day variability of the CV calculated from maximal isokinetic knee extension efforts, and to describe how this measurement error affects the accuracy of the CV as a distinguishing criterion between maximal and submaximal efforts. Thirty-one healthy males (mean age 25±4.5 years) completed three maximal and three submaximal isokinetic knee extension efforts on two separate occasions. Although submaximal CVs were significantly greater than maximal CVs (15.6 versus 3.7% ; p< 0.01), there was considerable overlap between submaximal and maximal CV frequency distributions. More importantly, an individual observed CV could vary 3.1% as a result of day-to-day variation or measurement error. This range in possible CV scores should be considered when comparing an individual's score to proposed cut-off points. Since individual CVs vary considerably from day-to-day, and since precise cut-off values distinguishing between maximal and submaximal conditions cannot be identified, CV scores must be interpreted cautiously, and the potential errors in relying extensively on this approach to identifying insincere efforts should be recognised.