Search results for "Categorical variable"

Categorical versus geometric morphometric approaches to characterizing the evolution of morphological disparity in Osteostraci (Vertebrata, stem Gnat…

2020

Morphological variation (disparity) tends to be evaluated through two non-mutually exclusive approaches: (i) quantitatively, through geometric morphometrics, and (ii) in terms of discrete, ‘cladistic’, or categorical characters. Uncertainty over the comparability of these approaches diminishes the potential to obtain nomothetic insights into the evolution of morphological disparity, and the few benchmarking studies conducted so far show contrasting results. Here, we apply both approaches to characterising morphology in the stem-gnathostome vertebrate clade Osteostraci, in order to assess congruence between these alternative methods as well as to explore the evolutionary patterns of the grou…

‘Communication breakdown’: the evolution of signal unreliability and deception

2014

For a signalling system to be stable, signals must confer net fitness benefits to senders and receivers, which means that some aspect of their design must correlate with a quality that receivers benefit from knowing about. However, examples abound where this correlation is complicated by phenomena commonly referred to as deception and/or signal unreliability. We argue here that unreliability and deception are notions marred with conceptual ambiguities, often used as equivalent or as catch-all terms for qualitatively different processes. Signal unreliability refers to a pattern of design–information dissociation that can arise through different processes, some deceptive and some not, with di…

2018

Genome-Wide-Association-Studies have become a powerful method to link point mutations (e.g. single nucleotide polymorphisms (SNPs)) to a certain phenotype or a disease. However, their power to detect SNPs associated to polygenic diseases such as Alzheimer's Disease (AD) is limited, since they can only infer the pairwise relation of single SNPs to the phenotype and ignore possible effects of various SNP combinations. The common method to probe these possible complex genetic patterns is to compute a measure called linkage disequilibrium (LD). Despite the fact that several predictive patterns found with LD could successfully be applied to medical diagnosis, this measure still holds several dra…

Toward a direct and scalable identification of reduced models for categorical processes.

2017

The applicability of many computational approaches is dwelling on the identification of reduced models defined on a small set of collective variables (colvars). A methodology for scalable probability-preserving identification of reduced models and colvars directly from the data is derived—not relying on the availability of the full relation matrices at any stage of the resulting algorithm, allowing for a robust quantification of reduced model uncertainty and allowing us to impose a priori available physical information. We show two applications of the methodology: (i) to obtain a reduced dynamical model for a polypeptide dynamics in water and (ii) to identify diagnostic rules from a standar…

SLFTD: A Subjective Logic Based Framework for Truth Discovery

2019

Finding truth from various conflicting candidate values provided by different data sources is called truth discovery, which is of vital importance in data integration. Several algorithms have been proposed in this area, which usually have similar procedure: iteratively inferring the truth and provider’s reliability on providing truth until converge. Therefore, an accurate provider’s reliability evaluation is essential. However, no work pays attention to “how reliable this provider continuously providing truth”. Therefore, we introduce subjective logic, which can record both (1) the provider’s reliability of generating truth, and (2) reliability of provider continuously doing so. Our propose…

Validity of a questionnaire developed to measure the impact of a high‐fidelity simulation intervention: A feasibility study

2019

To evaluate the validity and responsiveness of a questionnaire developed to measure the impact of a high-fidelity simulation intervention.A pre- and postintervention design.In August 2017, 107 participants completed a questionnaire measuring knowledge and perceived self-confidence pre- and postintervention. Validity of the questionnaire was determined by expert reviews, individual interviews and estimates of the changes in knowledge and perceived self-confidence. The changes were estimated by the differences between paired proportions of participants. The responsiveness of the ordered categorical item scores on self-confidence was evaluated by the measure of systematic group change and indi…

Test-retest reliability of a new questionnaire on the diet and eating behavior of one year old children

2015

Background As part of a sub-study in the ongoing Norwegian RCT ‘Fit for Delivery’, a new questionnaire, using a combination of food frequency, scale, and categorical questions to gather data on the diets and eating patterns of one year olds, was developed and tested for reliability by test-retest. Results Of 102 parents recruited to the study, 94 completed both test and retest. Correlation coefficients (Spearman’s r, and/or Cohen’s kappa, where applicable) were high for all categories of question, with a mean value of 0.72 for Spearman’s r for food frequency variables, and a mean value of 0.75 for Cohen’s kappa for non-numeric variables such as breast feeding status, showing very high test-…

Facial emotion space in schizophrenia

2007

Introduction. Previous studies show that patients with schizophrenia have a deficit in facial emotion recognition. In the framework of emotion categorisation theories, the purpose of the present study was to test if this impairment could result from abnormal boundaries between emotions (whether these boundaries are shifted along continuums or are less sharpened). Method. Twenty-six schizophrenic patients and the same number of healthy participants were required to perform a facial emotion recognition task and an emotion categorisation task with different emotion intensities obtained using morphing techniques. Results. The main results indicate that schizophrenic patients exhibited an emotio…

Fibred Categories and the Six Functors Formalism

2019

In Section 1, we introduce the basic language used in this book, the so-called premotivic categories and their functoriality. This is an extension of the classical notion of fibered categories. They appear with different categorical structures. In Section2, the language of premotivic categories is specialized to that of triangulated categories and to algebraic geometry. We introduce several axioms of such categories which ultimately will lead to the full six functors formalism. An emphasis is given on the study of the main axioms, with a special care about the so-called localization axiom. Then in Section 3, the general theory of descent is formulated in the language of premotivic model cat…

Making Every "Point" Count: Identifying the Key Determinants of Team Success in Elite Men’s Wheelchair Basketball

2019

Wheelchair basketball coaches and researchers have typically relied on box score data and the Comprehensive Basketball Grading System to inform practice, however, these data do not acknowledge how the dynamic perspectives of teams change, vary and adapt during possessions in relation to the outcome of a game. Therefore, this study aimed to identify the key dynamic variables associated with team success in elite men’s wheelchair basketball and explore the impact of each key dynamic variable upon the outcome of performance through the use of binary logistic regression modelling. The valid and reliable template developed by Francis, Owen and Peters (2019) was used to analyse video footage in S…