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Research Article, Anatomy, Mathematics, Prefrontal Cortex, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Head, Functional Electrical Stimulation, Physical Sciences, Psychology, Analysis of Variance, Sensory Perception, Heart Rate, Surgical and Invasive Medical Procedures, Biology and Life Sciences, Cognition, Neuroscience, Research and Analysis Methods, Medicine, Brain, Cardiology, Ears, Time Measurement, Social Sciences, Science, Medicine and Health Sciences, Statistical Methods, Cognitive Science, and Statistics

The present study investigated the effects of transcutaneous vagus nerve stimulation on cardiac vagal activity, the activity of the vagus nerve regulating cardiac functioning. We applied stimulation on the left cymba conchae and tested the effects of different stimulation intensities on a vagally-mediated heart rate variability pagerameter (i.e., the root mean square of successive differences) as well as on subjective ratings of strength of perceived stimulation intensity and unpleasantness due to the stimulation. Three experiments (within-subject designs, M = 61 healthy participants each) were carried out: In Experiment 1, to choose one fixed stimulation intensity for the subsequent studies, we compared three preset stimulation intensities (i.e., 0.5, 1.0 and 1.5 mA) with each other. In Experiment 2, we compared the set stimulation method with the free stimulation method, in which the participants were instructed to freely choose an intensity. In Experiment 3, to control for placebo effects, we compared both methods (i.e., set stimulation vs. free stimulation) with their respective sham stimulations. In the three experiments, an increase of cardiac vagal activity was found from resting to the stimulation phases. However, this increase in cardiac vagal activity was not dependent on stimulation intensity (Experiment 1), the method used to stimulate (i.e., set vs. free; Experiment 2), or whether stimulation was active or sham (Experiment 3). This pattern of results was solidly supported by Bayesian estimations. On the subjective level, higher stimulation intensities were perceived as significantly stronger and a stronger stimulation was generally also perceived as more unpleasant. The results suggest that cardiac vagal activity may be similarly influenced by afferent vagal stimuli triggered by active and sham stimulation with different stimulation intensities. Potential explanations for these findings and its implications for future research with tVNS are discussed.

Research Article, Cognitive Psychology, Computing Methods, Mathematics, Thermodynamics, Geographical Locations, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Physical Sciences, Entropy, Psychology, Distance Measurement, People and Places, Physics, Biology and Life Sciences, Cognition, Computer and Information Sciences, Neuroscience, Fuzzy Logic, Asia, Research and Analysis Methods, Equipment, Medicine, Factor Analysis, Korea, Social Sciences, Decision Making, Science, Statistical Methods, Cognitive Science, Number Theory, and Statistics

As the airline industry has become ever-more competitive and profitability more tenuous, airline service quality management has grown more important to airlines. Although many studies have focused on the evaluation of airline service quality, some common limitations need to be noted. First, traditional fuzzy logics were utilized to present linguistic variables as fuzzy numbers. However, precise quantification of lower and upper bounds with a single number is often difficult; thus, interval-valued fuzzy sets that represent the lower and upper bounds in the fuzzy number as an interval form should be applied instead. Second, while some studies have applied various multiple-criteria decision-making method [MCDM] and the service quality (SERVQUAL) method for evaluation of airline service quality, few have utilized grey relational analysis (GRA, a simple and data-driven MCDM method applicable to environments with incomplete information) and the service performance (SERVPERF), a performance-based measure that can resolve the ambiguity issue of the expectations construct in SERVQUAL. Third, extant studies dealing with the issue of weighting criteria in the evaluation of airline service quality have focused only on either subjective or objective weights, though weighting criteria based on a combined objective/subjective approach would be much better than those just considering the subjective approach. The present study endeavored to fill these literature gaps by developing, for evaluation of airline service quality, interval-valued fuzzy GRA with SERVPERF based on both subjective and objective weights. It contributes to the field by incorporating the 22 criteria from SERVPERF to effectively account for the various characteristics of airline service. Additionally, it is the first study to utilize interval-valued fuzzy GRA together with a novel technique that combines a subjective/objective weighting method for integration of objective decision-matrix-derived information with subjective decision-maker preferences. The supplemental empirical case study of airline service evaluation, further, provides researchers and practitioners with a means of better understanding the proposed approach in the practical perspectives.

Research Article, Mathematics, Anatomy, Classical Mechanics, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Physical Sciences, Distance Measurement, Analysis of Variance, Research Assessment, Physics, Software Engineering, Software Tools, Instrumentation, Biology and Life Sciences, Computer and Information Sciences, Research and Analysis Methods, Musculoskeletal System, Computer Software, Kinematics, Medicine, Research Validity, Science, Medicine and Health Sciences, Statistical Methods, and Statistics

An objective analysis of the human movement can help both clinical assessment and sports performance. Kinovea is a free 2D motion analysis software that can be used to measure kinematic parameters. This low-cost technology has been used in sports sciences, as well as in the clinical and research fields. One interesting tool is that it can measure an object (or person) passing in front of the camera, taking into account the perspective between the camera and the recorded object. Although it has been validated as a tool to assess time-related variables, few studies assessed its validity compared to a Gold Standard; furthermore, its reliability in different perspectives has not been previously assessed. The main objective of this study is to determine the validity of the Kinovea software compared to AutoCAD, and its intra and inter-rater reliability in obtaining coordinates data; a second objective is to compare their results at 4 different perspectives (90°, 75°, 60° and 45°) and to assess the inter and intra rater reliability at each perspective. For this purpose, a wire structure figure in the shape of a human lower limb was designed and measured in AutoCAD; it was then recorded during a pendular motion with a video-camera placed at distance of 5 m and analyzed with Kinovea in the 4 perspectives (90°, 75°, 60° and 45°). Each frame was examined by three observers who made two attempts. A multiple approach was applied involving the analysis of the systematic error, with a two-way ANOVA 2x4; the relative reliability with Intraclass Correlation Coefficient (ICC) and the Coefficient of Variance (CV) (95% confidence interval); and the absolute reliability with the Standard Error (SE). The results indicate that the Kinovea software is a valid and reliable tool that is able to measure accurately at distances up to 5 m from the object and at an angle range of 90°–45°. Nevertheless, for optimum results an angle of 90° is suggested.

MULTIVARIATE ANALYSES, Applied Mathematics, Algorithms, Probability Theory, Research Article, Mathematics, Statistical Dispersion, Ecology and Environmental Sciences, Engineering and Technology, Mathematical and statistical techniques, Microbial Ecology, Statistical Distributions, Measurement, Simulation and Modeling, Monte Carlo method, Ecology, Genetics, Physical sciences, Mathematics and Statistics, Distance Measurement, Genomics, LATENT VARIABLE MODELS, Data Visualization, Biology and Life Sciences, Computer and Information Sciences, Research and analysis methods, Microbiology, Medicine, Microbiome, Microbial Genomics, Medical Microbiology, Science, Statistical methods, and Statistics

Explorative visualization techniques provide a first summary of microbiome read count datasets through dimension reduction. A plethora of dimension reduction methods exists, but many of them focus primarily on sample ordination, failing to elucidate the role of the bacterial species. Moreover, implicit but often unrealistic assumptions underlying these methods fail to account for overdispersion and differences in sequencing depth, which are two typical characteristics of sequencing data. We combine log-linear models with a dispersion estimation algorithm and flexible response function modelling into a framework for unconstrained and constrained ordination. The method is able to cope with differences in dispersion between taxa and varying sequencing depths, to yield meaningful biological patterns. Moreover, it can correct for observed technical confounders, whereas other methods are adversely affected by these artefacts. Unlike distance-based ordination methods, the assumptions underlying our method are stated explicitly and can be verified using simple diagnostics. The combination of unconstrained and constrained ordination in the same framework is unique in the field and facilitates microbiome data exploration. We illustrate the advantages of our method on simulated and real datasets, while pointing out flaws in existing methods. The algorithms for fitting and plotting are available in the R-package RCM.

Research Article, Mathematics, Sociology, Regression Analysis, Professions, Geographical Locations, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Population Groupings, Physical Sciences, Distance Measurement, People and Places, Labor Economics, Oceania, Pharmacology, Heroin, Criminology, Research and Analysis Methods, Equipment, Medicine, Australia, Employment, Behavioral Pharmacology, Economics, Police, Social Sciences, Science, Recreational Drug Use, Medicine and Health Sciences, Linear Regression Analysis, Statistical Methods, and Statistics

Distance to health services is known to be negatively associated with usage and needle and syringe programs (NSPs) for people who inject drugs (PWID) are no different. Australia has a mixture of NSP modalities (primary or secondary fixed-site NSPs), which may present unique barriers to access. In this study, we explore 1) the effect of distance to NSPs on individual-level needle and syringe coverage, and 2) differences in coverage dependent on NSP modality. Using data from 219 PWID in an ongoing cohort study in Melbourne, Australia, we measured the straight-line distance from participants' residence to their nearest primary or secondary fixed-site NSP. We analysed the relationship between geographical distance and coverage via regression analysis. The median distance to any type of NSP was 1872 metres. Regardless of service type, 52% of participants lived within 2 kms of a fixed-site NSP and 87% lived within 5 kms. We found no association between distance to NSPs and syringe coverage or a significant difference in coverage by nearest service type. Our findings suggest that the number and distribution of NSPs in Melbourne, Australia caters adequately for the population of PWID.

Applied Mathematics, Algorithms, Research Article, Memory, Cognitive Psychology, Mathematics, Engineering and Technology, Mathematical and Statistical Techniques, Measurement, Simulation and Modeling, Physical Sciences, Psychology, Distance Measurement, Memory Recall, Biology and Life Sciences, Cognition, Computer and Information Sciences, Neuroscience, Computer Networks, Forecasting, Research and Analysis Methods, Medicine, Similarity Measures, Learning and Memory, Social Sciences, Science, Decision Making, Computing Systems, Internet, Statistical Methods, Cognitive Science, and Statistics

This paper describes an approach for improving the accuracy of memory-based collaborative filtering, based on the technique for order of preference by similarity to ideal solution (TOPSIS) method. Recommender systems are used to filter the huge amount of data available online based on user-defined preferences. Collaborative filtering (CF) is a commonly used recommendation approach that generates recommendations based on correlations among user preferences. Although several enhancements have increased the accuracy of memory-based CF through the development of improved similarity measures for finding successful neighbors, there has been less investigation into prediction score methods, in which rating/preference scores are assigned to items that have not yet been selected by a user. A TOPSIS solution for evaluating multiple alternatives based on more than one criterion is proposed as an alternative to prediction score methods for evaluating and ranking items based on the results from similar users. The recommendation accuracy of the proposed TOPSIS technique is evaluated by applying it to various common CF baseline methods, which are then used to analyze the MovieLens 100K and 1M benchmark datasets. The results show that CF based on the TOPSIS method is more accurate than baseline CF methods across a number of common evaluation metrics.

Research Article, Mathematics, Anatomy, Anthropometry, Regression Analysis, Engineering and Technology, Mathematical and Statistical Techniques, Optical Equipment, Measurement, Cameras, Physical Sciences, Distance Measurement, Statistics (Mathematics), Biology and Life Sciences, Research and Analysis Methods, Musculoskeletal System, Equipment, Medicine, Ellipses, Malnutrition, Nutrition, Science, Geometry, Arms, Linear Regression Analysis, Medicine and Health Sciences, Limbs (Anatomy), and Statistical Methods

Background Manually measured anthropometric quantities are used in many applications including human malnutrition assessment. Training is required to collect anthropometric measurements manually, which is not ideal in resource-constrained environments. Photogrammetric methods have been gaining attention in recent years, due to the availability and affordability of digital cameras. Objective The primary goal is to demonstrate that height and mid-upper arm circumference (MUAC)–indicators of malnutrition–can be accurately estimated by applying linear regression to distance measurements from photographs of participants taken from five views, and determine the optimal view combinations. A secondary goal is to observe the effect on estimate error of two approaches which reduce complexity of the setup, computational requirements and the expertise required of the observer. Methods Thirty-one participants (11 female, 20 male; 18–37 years) were photographed from five views. Distances were computed using both camera calibration and reference object techniques from manually annotated photos. To estimate height, linear regression was applied to the distances between the top of the participants head and the floor, as well as the height of a bounding box enclosing the participant’s silhouette which eliminates the need to identify the floor. To estimate MUAC, linear regression was applied to the mid-upper arm width. Estimates were computed for all view combinations and performance was compared to other photogrammetric methods from the literature—linear distance method for height, and shape models for MUAC. Results The mean absolute difference (MAD) between the linear regression estimates and manual measurements were smaller compared to other methods. For the optimal view combinations (smallest MAD), the technical error of measurement and coefficient of reliability also indicate the linear regression methods are more reliable. The optimal view combination was the front and side views. When estimating height by linear regression of the distance from the head to the floor, the mean MAD was 10.51 mm ± 6.52 mm SD, and when estimating height from the bounding box using the reference object, the mean MAD per participant was 11.53 mm ± 6.43 mm SD. When estimating MUAC from the mid-upper arm radius using the reference object, the mean MAD was 7.24 mm ± 4.79 mm SD. The mean MAD for all methods when using camera calibration was 2–3 mm smaller. Conclusions Applying linear regression to distance measurements from photos of adults taken from multiple view angles has been shown to accurately estimate height and MUAC to within the accuracy required for nutrition assessment. Future work will focus on automating the landmark detection, and validating the methods on populations that include undernourished adults and children of all nutrition statuses. These future works will improve the practicality of this method as a potential tool for nutrition assessment by novice users.

Research Errors, Research Article, Cognitive Psychology, Theory of Mind, Mathematics, Anatomy, Sociology, Engineering and Technology, Mathematical and Statistical Techniques, Eyes, Measurement, Pervasive Developmental Disorders, Head, Physical Sciences, Psychology, Analysis of Variance, Developmental Psychology, Research Assessment, Autism Spectrum Disorder, Statistics (Mathematics), Biology and Life Sciences, Social Research, Neuroscience, Research and Analysis Methods, Medicine, Ocular System, Social Sciences, Time Measurement, Science, Attention, Medicine and Health Sciences, Statistical Methods, and Cognitive Science

Considerable debate has focused on whether adults possess an implicit system for representing others’ mental states. Some argue that people automatically represent the perspective of others using evidence from altercentric interference—cases in which another agent’s perspective affects the speed with which one can report one’s own perspective. Others have argued that altercentric interference is not always specific to social stimuli and thus may represent a simpler process such as submentalizing. To distinguish between these positions, Study 1 developed a novel measure of altercentric interference—a “sandbox” measure—that allowed us to more sensitively assess altercentric interference across social and non-social conditions. We replicated previous findings showing that participants experience both egocentric and altercentric interference, but we found that these effects emerge equally in social and non-social conditions. To further test whether altercentric interference emerges in social perspective-taking situations, Study 2 conducted a conceptual replication of a study which used a novel “goggle” paradigm to assess whether individuals implicitly represent others’ perspectives. Although we failed to find evidence of altercentric interference in response times, participants’ accuracy reflected the possibility of interference from others’ perspectives. We argue that these findings provide support for the idea that altercentric interference in response to social stimuli (an avatar) is driven by perspective-taking mechanisms, while such interference in response to non-social stimuli (an arrow) is driven by attention-cuing mechanisms.

Phenols, Probability Theory, Research Article, Medição, Mathematics, Covariance, Plant Breeding, Crops, Mathematical and Statistical Techniques, Phakopsora, Multivariate Analysis, Chemical Compounds, Measurement, Soybeans, Agriculture, Plant Physiology, Physical Sciences, Analysis of Variance, Leaves, Plants, Crop Science, Plant Science, Agronomy, Soybean, Chemistry, Statistics (Mathematics), Biology and Life Sciences, Soja, Research and Analysis Methods, Random Variables, Plant Anatomy, Physiology, Medicine, Ferrugem, Effects, Atividade Enzimática, Science, Soybean rust, Statistical Methods, and Principal Component Analysis

Submitted by Marcilene Souza (marcilenesouza86@yahoo.com.br) on 2018-04-16T17:44:43Z No. of bitstreams: 1 artigo.pdf: 3077866 bytes, checksum: 6b325a61b3f8865c33688416ce5a7e71 (MD5) Approved for entry into archive by Nathália Faria da Silva (nathaliafsilva.ufv@gmail.com) on 2018-04-18T12:09:46Z (GMT) No. of bitstreams: 1 artigo.pdf: 3077866 bytes, checksum: 6b325a61b3f8865c33688416ce5a7e71 (MD5) Made available in DSpace on 2018-04-18T12:09:46Z (GMT). No. of bitstreams: 1 artigo.pdf: 3077866 bytes, checksum: 6b325a61b3f8865c33688416ce5a7e71 (MD5) Previous issue date: 2018-01-19 Asian rust affects the physiology of soybean plants and causes losses in yield. Repeatability coefficients may help breeders to know how many measurements are needed to obtain a suitable reliability for a target trait. Therefore, the objectives of this study were to determine the repeatability coefficients of 14 traits in soybean plants inoculated with Phakopsora pachyrhizi and to establish the minimum number of measurements needed to predict the breeding value with high accuracy. Experiments were performed in a 3x2 factorial arrange- ment with three treatments and two inoculations in a random block design. Repeatability coefficients, coefficients of determination and number of measurements needed to obtain a certain reliability were estimated using ANOVA, principal component analysis based on the covariance matrix and the correlation matrix, structural analysis and mixed model. It was observed that the principal component analysis based on the covariance matrix out-per- formed other methods for almost all traits. Significant differences were observed for all traits except internal CO2 concentration for the treatment effects. For the measurement effects, all traits were significantly different. In addition, significant differences were found for all Treatment x Measurement interaction traits except coumestrol, chitinase and chlorophyll content. Six measurements were suitable to obtain a coefficient of determination higher than 0.7 for all traits based on principal component analysis. The information obtained from this research will help breeders and physiologists determine exactly how many measure- ments are needed to evaluate each trait in soybean plants infected by P. pachyrhizi with a desirable reliability.