Introduction: Supervised physical exercise has been shown to benefit patients with heart failure with preserved/mildly reduced ejection fraction (HFpEF/HfmrEF) by improving symptoms and diastolic function. This study aimed to investigate the correlation between unsupervised daily physical activity and changes in daily pulmonary artery pressure (PAP) in patients with stable NYHA class III heart failure (HF) and left ventricular ejection fraction (LVEF) of 45% or higher.
Methods: Daily physical activity was monitored over a 3-month period using a Holter-ECG with an accelerometer that calculated an activity-associated, heart rate-derived metabolic equivalent of task (MET) score.
J Comput Graph Stat
December 2023
For measuring the strength of visually-observed subpopulation differences, the Population Difference Criterion is proposed to assess the statistical significance of visually observed subpopulation differences. It addresses the following challenges: in high-dimensional contexts, distributional models can be dubious; in high-signal contexts, conventional permutation tests give poor pairwise comparisons. We also make two other contributions: Based on a careful analysis we find that a balanced permutation approach is more powerful in high-signal contexts than conventional permutations.
View Article and Find Full Text PDFSteed . () illustrates the crucial impact that the quality of official statistical data products may exert on the accuracy, stability, and equity of policy decisions on which they are based. The authors remind us that data, however responsibly curated, can be fallible.
View Article and Find Full Text PDFBackground: Perfect hearing is crucial to the practice of various professions, such as instrument makers, musicians, sound engineers, and other professions not related to music, such as sonar technicians. For people of these occupational groups, we propose the term "professional ear user" (PEU) in analogy to "professional voice user". PEUs have special requirements for their hearing health, as they have well-known above-average auditory perceptual abilities on which they are professionally dependent.
View Article and Find Full Text PDFThe paper describes a mathematical model of the molecular switches of cell survival, apoptosis, and necroptosis in cellular signaling pathways initiated by tumor necrosis factor 1. Based on experimental findings in the literature, we constructed a Petri net model based on detailed molecular reactions of the molecular players, protein complexes, post-translational modifications, and cross talk. The model comprises 118 biochemical entities, 130 reactions, and 299 edges.
View Article and Find Full Text PDFThe two main approaches in the study of breast cancer are histopathology (analyzing visual characteristics of tumors) and genomics. While both histopathology and genomics are fundamental to cancer research, the connections between these fields have been relatively superficial. We bridge this gap by investigating the Carolina Breast Cancer Study through the development of an integrative, exploratory analysis framework.
View Article and Find Full Text PDFThe specification and application of policies and guidelines for public health, medical education and training, and screening programmes for preventative medicine are all predicated on trust relationships between medical authorities, health practitioners and patients. These relationships are in turn predicated on a verbal contract that is over two thousand years old. The impact of information and communication technology (ICT), underpinning Health 4.
View Article and Find Full Text PDFElectrocardiography (ECG) is a quick and easily accessible method for diagnosis and screening of cardiovascular diseases including heart failure (HF). Artificial intelligence (AI) can be used for semi-automated ECG analysis. The aim of this evaluation was to provide an overview of AI use in HF detection from ECG signals and to perform a meta-analysis of available studies.
View Article and Find Full Text PDFEngagement in cognitively demanding activities is beneficial to preserving cognitive health. Our goal was to demonstrate the utility of frequentist, Bayesian, and fiducial statistical methods for evaluating the robustness of effects in identifying factors that contribute to cognitive engagement for older adults experiencing cognitive decline. We collected a total of 504 observations across two longitudinal waves of data from 28 cognitively impaired older adults.
View Article and Find Full Text PDFAs a classical problem, covariance estimation has drawn much attention from the statistical community for decades. Much work has been done under the frequentist and the Bayesian frameworks. Aiming to quantify the uncertainty of the estimators without having to choose a prior, we have developed a fiducial approach to the estimation of covariance matrix.
View Article and Find Full Text PDFIschaemic heart disease is among the most frequent causes of death. Early detection of myocardial pathologies can increase the benefit of therapy and reduce the number of lethal cases. Presence of myocardial scar is an indicator for developing ischaemic heart disease and can be detected with high diagnostic precision by magnetic resonance imaging.
View Article and Find Full Text PDFIn pathology, tissue images are evaluated using a light microscope, relying on the expertise and experience of pathologists. There is a great need for computational methods to quantify and standardize histological observations. Computational quantification methods become more and more essential to evaluate tissue images.
View Article and Find Full Text PDFJ Gerontol B Psychol Sci Soc Sci
January 2020
Objectives: We apply new statistical models to daily diary data to advance both methodological and conceptual goals. We examine age effects in within-person slopes in daily diary data and introduce Generalized Fiducial Inference (GFI), which provides a compromise between frequentist and Bayesian inference. We use daily stressor exposure data across six domains to generate within-person emotional reactivity slopes with daily negative affect.
View Article and Find Full Text PDFIn applications of item response theory (IRT), it is often of interest to compute confidence intervals (CIs) for person parameters with prescribed frequentist coverage. The ubiquitous use of short tests in social science research and practices calls for a refinement of standard interval estimation procedures based on asymptotic normality, such as the Wald and Bayesian CIs, which only maintain desirable coverage when the test is sufficiently long. In the current paper, we propose a simple construction of second-order probability matching priors for the person parameter in unidimensional IRT models, which in turn yields CIs with accurate coverage even when the test is composed of a few items.
View Article and Find Full Text PDFTwo classical multivariate statistical problems, testing of multivariate normality and the k-sample problem, are explored by a novel analysis on several resolutions simultaneously. The presented methods do not invert any estimated covariance matrix. Thereby, the methods work in the High Dimension Low Sample Size situation, i.
View Article and Find Full Text PDFSummary: isiKnock is a new software that automatically conducts in silico knockouts for mathematical models of signaling pathways. The software allows for the prediction of the behavior of biological systems after single or multiple knockout. The implemented algorithm applies transition invariants and the novel concept of Manatee invariants.
View Article and Find Full Text PDFSamejima's graded response model (GRM) has gained popularity in the analyses of ordinal response data in psychological, educational, and health-related assessment. Obtaining high-quality point and interval estimates for GRM parameters attracts a great deal of attention in the literature. In the current work, we derive generalized fiducial inference (GFI) for a family of multidimensional graded response model, implement a Gibbs sampler to perform fiducial estimation, and compare its finite-sample performance with several commonly used likelihood-based and Bayesian approaches via three simulation studies.
View Article and Find Full Text PDFGeneralized fiducial inference (GFI) has been proposed as an alternative to likelihood-based and Bayesian inference in mainstream statistics. Confidence intervals (CIs) can be constructed from a fiducial distribution on the parameter space in a fashion similar to those used with a Bayesian posterior distribution. However, no prior distribution needs to be specified, which renders GFI more suitable when no a priori information about model parameters is available.
View Article and Find Full Text PDFThe current European system governed by the three EC directives 93/42/EEC (Medical Device Directive), 98/79/EC (In-Vitro Diagnostic Directive) and 90/385/EEC (Active Implantable Medical Device Directive) regulates marketing and post-market surveillance of medical devices in the European Economic Area (EEA). In cases of incidents raising the field safety corrective actions (FSCA), manufacturers have to inform the responsible Competent Authority (CA; in Germany this is the Federal Institute for Drugs and Medical Devices, BfArM) and the public by field safety notices (FSN). In this study we analyzed FSN of respirators and consumables directly required for their function, whereas devices for anesthesia and gas delivery were excluded.
View Article and Find Full Text PDFAdv Exp Med Biol
October 2015
The current European system for medical devices is governed by three EC directives: the Medical Device Directive 93/42/EEC, the In-Vitro Diagnostic Directive 98/79/EC and the Active Implantable Medical Device Directive 90/385/EEC and regulates marketing and post-market surveillance of medical devices in the European Economic Area. In cases of incidents and field safety corrective actions (FSCA) manufacturers have to inform the responsible Competent Authority, which is the Federal Institute for Drugs and Medical Devices (BfArM) and the public by field safety notices (FSN). In this study we analyzed FSN of medical devices exclusively serving for diagnostics or treatment in pulmonology (e.
View Article and Find Full Text PDFThe European Directive 98/79/EC on in vitro diagnostics (IVD) regulates marketing and post market surveillance of IVD in the European Economic Area. In cases of incidents and field safety corrective actions (FSCA) manufacturers have to inform responsible competent authority (CA) and public by field safety notices (FSN). We analyzed FSCA and FSN of IVD for infection testing (culture media, reagents, kits, control materials, as well as culture-based analyzers and their general consumables) published by the Federal Institute for Drugs and Medical Devices (BfArM) in Bonn, Germany in 2005-2012 in regard to the European Regulatory Framework of Medical Devices (MEDDEV).
View Article and Find Full Text PDFMultivariate Behav Res
March 2016
Objective: The purpose of this study was to determine resident satisfaction with an acute care psychiatric clinic designed in collaboration with a nearby community mental health center. We also sought to demonstrate that this rotation helps meet program requirements for emergency psychiatry training, provides direct assessments of resident interviewing skills and clinical knowledge in the postgraduate year-1, and provides exposure to public sector systems of care.
Methods: We developed a resident satisfaction questionnaire and fielded it to each of the residents who participated in the clinic over the first 3 years.
Acute cellular necrosis occurring minutes to hours after massive ionizing radiation exposure (IR) results from rapid membrane lipid peroxidation, blebbing and membrane breakdown. We have shown, previously, that certain polymer surfactants can restore structural integrity and transport barrier function of cell membranes following high-dose IR. We now investigate, specifically, the efficacy of the amphiphilic surfactant Poloxamer 188 (P188) in preventing acute necrosis of adult rat skeletal muscle cells after high-dose IR.
View Article and Find Full Text PDFP188, a triblock copolymer of the form poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) helps seal electroporated cell membranes, arresting the leakage of intracellular materials from the damaged cells. To explore the nature of the interaction between P188 and cell membranes, we have constructed a model system that assesses the ability of P188 to insert into lipid monolayers. Using concurrent Langmuir isotherm and fluorescence microscopy measurements, we find that P188 changes the phase behavior and morphology of the monolayers.
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