Analytical and numerical investigation of mixed-type functional differential equations

NOTICE: this is the author’s version of a work that was accepted for publication in Journal of computational and applied mathematics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of computational and applied mathematics, 234 (2010), doi: 10.1016/j.cam.2010.01.028This journal article is concerned with the approximate solution of a linear non-autonomous functional differential equation, with both advanced and delayed arguments

COVID-19 infection and risk analysis: a short introduction

This work is part of a study about COVID-19 pandemic in Mozambique. Here we reproduce the first part of such study where a general introduction about the background and motivational aspects of COVID-19 in the world is made. Also, the relevance of mathematical and statistical modeling, the concepts of risk, risk analysis and spatial epidemiology are detailed. An introductory briefing on risk measures in epidemiology is performed. In the present work, we deal with risk assessment in epidemiology, we address aspects such as uncertainty and variability, types of risk assessment and its steps, methods, and relevant conditions for the quality of risk assessment. At the moment, the considered data set is still incomplete, only preliminary estimated models and preliminary results were obtained. A continuation of this manuscript will illustrate the models estimated and applied to the modeling of infectious diseases, presenting those with a mathematical and statistical approach to COVID-19 infection. Also, we will present the mapping of diseases. The preliminary results obtained with the provisional data set agree with similar performed studies.This work was supported by Portuguese funds through the Center of Naval Research (CINAV), Portuguese Naval Academy, Portugal and The Portuguese Foundation for Science and Technology (FCT), through the Center for Computational and Stochastic Mathematics (CEMAT), University of Lisbon, Portugal, project UID/Multi/04621/2019. Also, this research was partially funded by FCT—Fundação para a Ciência e a Tecnologia under the project— UIBD/00006/2020”info:eu-repo/semantics/publishedVersio

The numerical solution of forward–backward differential equations: Decomposition and related issues

NOTICE: this is the author’s version of a work that was accepted for publication in Journal of computational and applied mathematics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of computational and applied mathematics, 234,(2010), doi: 10.1016/j.cam.2010.01.039This journal article discusses the decomposition, by numerical methods, of solutions to mixed-type functional differential equations (MFDEs) into sums of “forward” solutions and “backward” solutions

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Numerical Solution of a Forward-Backward Equation From Physiology

The aim of this paper is to determine the numerical solution of an equation which models the nerve conduction in a myelinated axon. An appropriate stimulus begins a propagate action potential which travels down the axon. It can be understood as a traveling wave of voltage. It is proposed a computational approximation for the solution of a forward-backward differential equation that models nerve conduction. We look for a solution of an equation defined in R, which tends to known values at ±¥. Extending the approach introduced in [13, 29, 14] for linear case, a numerical method for the solution of problem, adapted to non linear case, is described. Numerical results using a test problem and a continuation method are computed and analyzed

Comparing Childhood Hypertension Prevalence in Several Regions in Portugal

The pediatric high blood pressure has severe the risk factors and it’s prevention is mandatory. To evaluate the pediatric arterial hypertension caregivers Knowledge, in [1, 2] was done a preliminary study of an experimental and simple questionnaire with 5 questions previously introduced in [3]. The analysis of an improved questionnaire applied to children caregivers and filled online was completed in [4, 5]. In the present work, we obtain estimates about the childhood hypertension prevalence in several regions of Portugal. As preliminary approach, we perform an analysis of variance. The results evidences significant differences of high blood pressure prevalence between girls and boys; also the children’s age is a significant issue to take into consideration.info:eu-repo/semantics/publishedVersio

Evaluating the Static Relative Positioning Accuracy of a GPS Equipment by Linear Models

The processing of baselines with considerable length may not be successful due several problems, for example, the ionospheric and tropospheric delays estimates are not adequate. To reduce this problem, there exists some models to minimize the biases. The first-order ionospheric biases can be reduced by 98% 98% taking the combination of L 1 L1 and L 2 L2 carrier-phase. The equipment under evaluation uses this solution to the most baselines considered in our work. Still is necessary to reduce the tropospheric bias. An improved and advanced tropospheric bias mitigation strategy is used as alternative to a simpler one. The reduction of bias is verified and quantified using the rate of successful baselines processed by the GPS equipment which uses an improved strategy with a zenith tropospheric scale factor per station. We have built some models by general linear models to evaluate the performance of the equipment. We are aware that 1D and 2D present different behaviors, we analyzed both cases individually with each strategy. In this article, we present partially such analysis for 2D case.info:eu-repo/semantics/publishedVersio