Search results for "modelling."
showing 10 items of 1269 documents
gllvm : Fast analysis of multivariate abundance data with generalized linear latent variable models in R
2019
1.There has been rapid development in tools for multivariate analysis based on fully specified statistical models or “joint models”. One approach attracting a lot of attention is generalized linear latent variable models (GLLVMs). However, software for fitting these models is typically slow and not practical for large datsets. 2.The R package gllvm offers relatively fast methods to fit GLLVMs via maximum likelihood, along with tools for model checking, visualization and inference. 3.The main advantage of the package over other implementations is speed e.g. being two orders of magnitude faster, and capable of handling thousands of response variables. These advances come from using variationa…
EXPERIMENTAL SEISMIC ANALYSIS OF MONUMENTS FOR RISK MITIGATION
2008
An experimental investigation, at the moment in progress, for the evaluation of the seismic vulnerability of a monumental structure and the effects of some reinforcement devices are presented. Referring to this monumental structure, that is a church, the authors obtained the dynamically identified analytical model and recognized that the drum-dome system was one of the macro-elements with highest risk. This result was obtained by analyzing the linear behaviour. In order to study the nonlinear behaviour, tests on reduced scale models were necessary. The models, with and without risk mitigation reinforcements, were subjected to seismic input with rising intensity in order to know the effects …
Teachers' attitudes and self-efficacy on implementing inclusive education in Japan and Finland : A comparative study using multi-group structural equ…
2018
This study aims to explore relationships between teachers' attitudes, self-efficacy, and background variables regarding inclusive education by using a sample of 359 Japanese and 872 Finnish teachers. A multi-group structural equation modelling was conducted to find similarities and differences in how the background variables predict teachers' attitudes and self-efficacy. Experience in teaching students with disabilities had a positive effect on teachers' attitudes and self-efficacy in both countries. However, teachers' teaching career and the amount of inclusive education training affected them differently in Japan and Finland. The findings could be used to improve inclusive education train…
Data from: Transparency reduces predator detection in mimetic clearwing butterflies
2019
1. Predation is an important selective pressure and some prey have evolved conspicuous warning signals that advertise unpalatability (i.e. aposematism) as an antipredator defence. Conspicuous colour patterns have been shown effective as warning signals, by promoting predator learning and memory. Unexpectedly, some butterfly species from the unpalatable tribe Ithomiini possess transparent wings, a feature rare on land but common in water, known to reduce predator detection. 2. We tested if transparency of butterfly wings was associated with decreased detectability by predators, by comparing four butterfly species exhibiting different degrees of transparency, ranging from fully opaque to larg…
Data from: A mechanistic underpinning for sigmoid dose-dependent infection
2016
Theoretical models of environmentally transmitted diseases often assume that transmission is a constant process, which scales linearly with pathogen dose. Here we question the applicability of such an assumption and propose a sigmoidal form for the pathogens infectivity response. In our formulation, this response arises under two assumptions: 1) multiple invasion events are required for a successful pathogen infection and 2) the host invasion state is reversible. The first assumption reduces pathogen infection rates at low pathogen doses, while the second assumption, due to host immune function, leads to a saturating infection rate at high doses. The derived pathogen dose:infection rate -re…
Translating cross-lagged effects into incidence rates and risk ratios: The case of psychosocial safety climate and depression
2017
Longitudinal studies are the gold standard of empirical work and stress research whenever experiments are not plausible. Frequently, scales are used to assess risk factors and their consequences, and cross-lagged effects are estimated to determine possible risks. Methods to translate cross-lagged effects into risk ratios to facilitate risk assessment do not yet exist, which creates a divide between psychological and epidemiological work stress research. The aim of the present paper is to demonstrate how cross-lagged effects can be used to assess the risk ratio of different levels of psychosocial safety climate (PSC) in organisations, an important psychosocial risk for the development of dep…
A mathematical model of cardiovascular dynamics for the diagnosis and prognosis of hemorrhagic shock
2020
Abstract A variety of mathematical models of the cardiovascular system have been suggested over several years in order to describe the time-course of a series of physiological variables (i.e. heart rate, cardiac output, arterial pressure) relevant for the compensation mechanisms to perturbations, such as severe haemorrhage. The current study provides a simple but realistic mathematical description of cardiovascular dynamics that may be useful in the assessment and prognosis of hemorrhagic shock. The present work proposes a first version of a differential-algebraic equations model, the model dynamical ODE model for haemorrhage (dODEg). The model consists of 10 differential and 14 algebraic e…
A Multivariate Age-Structured Stochastic Model with Immunization Strategies to Describe Bronchiolitis Dynamics
2021
Bronchiolitis has a high morbidity in children under 2 years old. Respiratory syncytial virus (RSV) is the most common pathogen causing the disease. At present, there is only a costly humanized monoclonal RSV-specific antibody to prevent RSV. However, different immunization strategies are being developed. Hence, evaluation and comparison of their impact is important for policymakers. The analysis of the disease with a Bayesian stochastic compartmental model provided an improved and more natural description of its dynamics. However, the consideration of different age groups is still needed, since disease transmission greatly varies with age. In this work, we propose a multivariate age-struct…
Transcatheter indirect mitral annuloplasty induces annular and left atrial remodelling in secondary mitral regurgitation
2020
Abstract Aims Mitral annuloplasty using the Carillon Mitral Contour System (CMCS) reduces secondary mitral regurgitation (SMR) and leads to reverse left ventricular remodelling. The aim of this study was to evaluate the effect of the CMCS on the mitral valve annulus (MA) and left atrial volume (LAV). Methods and results We retrospectively evaluated the data of all patients treated with the CMCS at our centre. Using transthoracic echocardiography, MA diameters were assessed by measuring the anterolateral to posteromedial extend (ALPM) and the anterior to posterior (AP) dimensions, respectively. Also, LAV and left ventricular end‐diastolic volume (LVEDV) were assessed. Patients were examined …
Modelling of mercury emissions from large solid fuel combustion and biomonitoring in Cz-Pl border region
2016
Tightening of norms for air protection leads to a development of new and significantly more effective techniques for removing particulate matter, SOx and NOx from flue gas which originates from large solid fuel combustion. Recently, it has been found that combinations of these environmental technologies can also lead to the reduction of mercury emissions from coal power plants. Now the greatest attention is paid especially to the coal power plant in Opatovice nad Labem, close to Hradec Kralove. Its system for flue gas dedusting was replaced by a modern type of cloth fabric filter with the highest particle separation efficiency which belongs to the category of BAT. Using this technology, tog…