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“Tourist Madeira Wine Perception: A Structural Equation Modeling Approach”

Sampaio, Ana
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Aula
ENG
Relevância na Pesquisa
36.14%
The field of wine tourism is emerging at international level as a new product with significant economic potentialities and characteristics that may locate it in the paradigm of sustainable development. This paper analyzes a specific wine tourism segment, Madeira Wine tourism, in the global context of tourist consumer behavior, through perception‟s examination of wineries‟ visitors. Specifically, it is investigated the indirect influence of destination image construct on global tourist satisfaction with the travel, mediated by tourist wine involvement dimension. A Structural Equation Modeling (SEM) approach is used to develop and to test conceptualized relationships between one exogenous and two endogenous constructs: tourist perceptions about Madeira Island attractiveness (destination image), tourist Madeira wine involvement and global satisfaction constructs. The findings indicate that global tourist satisfaction is directly influenced by the level of tourist wine involvement and indirectly by tourist Madeira Island image. The police implications of the results must be integrated in the international context of wine tourism market segment in order to explore additional exchange profits from this economic activity...

Extending Object-Oriented Frameworks with Aspects for Enabling Automatic Support for Domain-Specic Modeling

Santos, André L.; Koskimies, Kai; Lopes, Antónia
Fonte: Department of Informatics, University of Lisbon Publicador: Department of Informatics, University of Lisbon
Tipo: Relatório
Publicado em /10/2007 POR
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In the context of framework-based development, Domain-Specic Modeling (DSM) is a paradigm that raises the level of abstraction of application engineering. Using a Domain-Specic Modeling Language (DSML), applications are described by domain concepts in a model from which the application code is generated. This paper presents an approach for automating the construction of a DSM infrastructure for an object-oriented framework, where a DSML and a code generator for building applications are automatically derived. The approach is able to signicantly reduce the cost of adopting and evolving a DSM infrastructure. The high degree of automation is possible by enhancing frameworks with an additional layer of specialization modules, relying on our previous work on framework specialization aspects. The approach was implemented in our ALFAMA tool, and validated by a case study on the Eclipse RCP

Predictive analytical and numerical modeling for orthogonal cutting

Praça, André Simões
Fonte: Universidade Nova de Lisboa Publicador: Universidade Nova de Lisboa
Tipo: Dissertação de Mestrado
Publicado em /09/2014 ENG
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In this thesis, a predictive analytical and numerical modeling approach for the orthogonal cutting process is proposed to calculate temperature distributions and subsequently, forces and stress distributions. The models proposed include a constitutive model for the material being cut based on the work of Weber, a model for the shear plane based on Merchants model, a model describing the contribution of friction based on Zorev’s approach, a model for the effect of wear on the tool based on the work of Waldorf, and a thermal model based on the works of Komanduri and Hou, with a fraction heat partition for a non-uniform distribution of the heat in the interfaces, but extended to encompass a set of contributions to the global temperature rise of chip, tool and work piece. The models proposed in this work, try to avoid from experimental based values or expressions, and simplifying assumptions or suppositions, as much as possible. On a thermo-physical point of view, the results were affected not only by the mechanical or cutting parameters chosen, but also by their coupling effects, instead of the simplifying way of modeling which is to contemplate only the direct effect of the variation of a parameter. The implementation of these models was performed using the MATLAB environment. Since it was possible to find in the literature all the parameters for AISI 1045 and AISI O2...

Past and current sediment dispersion pattern estimates through numerical modeling of wave climate: an example of the Holocene delta of the Doce River, Espírito Santo, Brazil

Bittencourt,Abílio C.S.P.; Dominguez,José M.L.; Martin,Louis; Silva,Iracema R.; de-Medeiros,Karla O.P.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2007 EN
Relevância na Pesquisa
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This paper presents a numerical modeling estimation of the sediment dispersion patterns caused by waves inciding through four distinct coastline contours of the delta plain of the Doce River during the Late Holocene. For this, a wave climate model based on the construction of wave refraction diagrams, as a function of current boundary conditions, was defined and was assumed to be valid for the four coastlines. The numerical modeling was carried out on basis of the refraction diagrams, taking into account the angle of approximation and the wave height along the coastline. The results are shown to be comparable with existing data regarding the directions of net longshore drift of sediments estimated from the integration of sediment cores, interpretation of aerial photographs and C14 datings. This fact apparently suggests that, on average, current boundary conditions appear to have remained with the same general characteristics since 5600 cal yr BP to the present. The used approach may prove useful to evaluate the sediment dispersion patterns during the Late Holocene in the Brazilian east-northeast coastal region.

A diachronic view of the net longshore sediment drift during the Late Holocene at the Jequitinhonha River delta, Brazil, using numerical modeling

Bittencourt,Abilio C.S.P.; Dominguez,José M.L.; Tanajura,Clemente A.S.; Silva,Iracema R.; Martin,Louis
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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Using numerical modeling, this work estimates sediment dispersion patterns caused by the incidence of waves in five distinct coastline contours of the Jequitinhonha River delta plain during the Late Holocene. For this study, a wave cliate odel based on the construction of ave refraction diagras relative to the current boundary conditions as defined and assumed to be valid for the five coastlines. Numerical modeling from the refraction diagrams was carried out considering the angle of incidence and wave height along the coastline. This work has allowed us to reproduce past and current patterns of net longshore sediment drift defined by a conceptual model developed from the integration of sediment cores, aerial photograph interpretation, C14 datings and geomorphic indicators of longshore drift. These results show that, on average, current wave conditions in the east-northeastern Brazilian region seem to have remained characteristically the same from approximately 5100 years BP until the present time. This type of information can be important when attempting to simulate possible future situations in terms of the long-term general behavior of the east-northeastern Brazilian coastal region.

Scavenging processes of atmospheric particulate matter: a numerical modeling of case studies

Gonçalves,Fábio Luiz Teixeira; Beheng,Klaus Dieter; Massambani,Oswaldo; Vautz,Wolfgang; Klockow,Dieter
Fonte: Sociedade Brasileira de Meteorologia Publicador: Sociedade Brasileira de Meteorologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 EN
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Below cloud scavenging processes have been investigated considering a numerical simulation, local atmospheric conditions and particulate matter (PM) concentrations, at different sites in Germany. The below cloud scavenging model has been coupled with bulk particulate matter counter TSI (Trust Portacounter dataset, consisting of the variability prediction of the particulate air concentrations during chosen rain events. The TSI samples and meteorological parameters were obtained during three winter Campaigns: at Deuselbach, March 1994, consisting in three different events; Sylt, April 1994 and; Freiburg, March 1995. The results show a good agreement between modeled and observed air concentrations, emphasizing the quality of the conceptual model used in the below cloud scavenging numerical modeling. The results between modeled and observed data have also presented high square Pearson coefficient correlations over 0.7 and significant, except the Freiburg Campaign event. The differences between numerical simulations and observed dataset are explained by the wind direction changes and, perhaps, the absence of advection mass terms inside the modeling. These results validate previous works based on the same conceptual model.

Principles of crop modelling and simulation: III. modeling of root growth and other belowground processes, limitations of the models, and the future of modeling in agriculture

DOURADO-NETO,D.; TERUEL,D. A.; REICHARDT,K.; NIELSEN,D.R.; FRIZZONE,J. A.; BACCHI,O.O.S.
Fonte: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz" Publicador: São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1998 EN
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36.14%
The first models of temporal variation of root systems appeared over 20 years ago. The complex architectural geometry of root systems; the wide range in size and diameter and the rapid growth and decomposition of finest roots; the different physiological activity of roots of different ages; the complex microbial processes occurring at the root-soil interface; the symbiotic relationships in the rhizosphere; the variable soil environment (physical, chemical and biological) in which roots develop are the challenges of quantifying the root growth. The models are not simple mechanisms to archive information in order to produce forecasts. Modeling represents a better way of synthesizing knowledge about different components of a system, summarizing data, and transferring research results to users.

Modeling heat and mass transfer in the heat treatment step of yerba maté processing

Peralta,J. M.; Schmalko,M. E.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2007 EN
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The aim of this research was to estimate the leaf and twig temperature and moisture content of yerba maté branches (Ilex paraguariensis Saint Hilaire) during heat treatment, carried out in a rotary kiln dryer. These variables had to be estimated (modeling the heat and mass transfer) due to the difficulty of experimental measurement in the dryer. For modeling, the equipment was divided into two zones: the flame or heat treatment zone and the drying zone. The model developed fit well with the experimental data when water loss took place only in leaves. In the first zone, leaf temperature increased until it reached 135°C and then it slowly decreased to 88°C at the exit, despite the gas temperature, which varied in this zone from 460°C to 120°C. Twig temperature increased in the two zones from its inlet temperature (25°C) up to 75°C. A model error of about 3% was estimated based on theoretical and experimental data on leaf moisture content.

A vibroacoustic application of modeling and control of linear parameter-varying systems

De Caigny,Jan; Camino,Juan F.; Oliveira,Ricardo C. L. F.; Peres,Pedro L. D.; Swevers,Jan
Fonte: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM Publicador: Associação Brasileira de Engenharia e Ciências Mecânicas - ABCM
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2010 EN
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36.14%
This paper applies recent advances in both modeling and control of Linear Parameter-Varying (LPV) systems to a vibroacoustic setup whose dynamics is highly sensitive to variations in the temperature. Based on experimental data, an LPV model is derived for this system using the State-space Model Interpolation of Local Estimates (SMILE) technique. This modeling technique interpolates linear time-invariant models estimated at distinct operating conditions of the system (in this case, different temperatures). Using the obtained LPV model, gain-scheduled and robust multiobjective H2/H∞ state feedback controllers are designed such that can consider a priori known bounds on the rate of parameter variation. Numerical simulations using the closed-loop systems are performed to validate the controllers and to show the advantages and versatility of the proposed techniques.

The Use of Matrix Methods in the Modeling of Spectroscopic Data Sets

Henry, Eric R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/1997 EN
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36.14%
We describe a general approach to the model-based analysis of sets of spectroscopic data that is built upon the techniques of matrix analysis. A model hypothesis may often be expressed by writing a matrix of measured spectra as the product of a matrix of spectra of individual molecular species and a matrix of corresponding species populations as a function of experimental conditions. The modeling procedure then requires the simultaneous determination of a set of species spectra and a set of model parameters (from which the populations are derived), such that this product yields an optimal description of the measured spectra. This procedure may be implemented as an optimization problem in the space of the (possibly nonlinear) model parameters alone, coupled with the efficient solution of a corollary linear optimization problem using matrix decomposition methods to obtain a set of species spectra corresponding to any set of model parameters. Known species spectra, as well as other information and assumptions about spectral shapes, may be incorporated into this general framework, using parametrized analytical functional forms and basis-set techniques. The method by which assumed relationships between global features (e.g., peak positions) of different species spectra may be enforced in the modeling without otherwise specifying the shapes of the spectra will be shown. We also consider the effect of measurement errors on this approach and suggest extensions of the matrix-based least-squares procedures applicable to situations in which measurement errors may not be assumed to be normally distributed. A generalized analysis procedure is introduced for cases in which the species spectra vary with experimental conditions.

Structural Modeling Extends QSAR Analysis of Antibody-Lysozyme Interactions to 3D-QSAR

Freyhult, Eva K.; Andersson, Karl; Gustafsson, Mats G.
Fonte: Biophysical Society Publicador: Biophysical Society
Tipo: Artigo de Revista Científica
Publicado em /04/2003 EN
Relevância na Pesquisa
36.14%
This work shows that quantitative multivariate modeling is an emerging possibility for unraveling protein-protein interactions using a combination of designed mutations with sequence and structure information. Using this approach, it is possible to stereochemically determine which residue properties contribute most to the interaction. This is illustrated by results from modeling of the interaction of the wild-type and 17 single and double mutants of a camel antibody specific for lysozyme. Linear multivariate models describing association and dissociation rates as well as affinity were developed. Sequence information in the form of amino acid property scales was combined with 3D structure information (obtained using molecular mechanics calculations) in the form of coordinates of the α-carbons and the center of the side chains. The results show that in addition to the amino acid properties of the mutated residues 101 and 105, the dissociation rate is controlled by the side-chain coordinate of residue 105, whereas the association is determined by the coordinates of residues 99, 100, 105 (side chain), 111, and 112. The great difference between the models for association and dissociation rates illustrates that the event of molecular recognition and the property of binding stability rely on different physical processes.

Markov Chain Modeling of Pyelonephritis-Associated Pili Expression in Uropathogenic Escherichia coli

Zhou, Baiyu; Beckwith, David; Jarboe, Laura R.; Liao, James C.
Fonte: Biophysical Society Publicador: Biophysical Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.14%
Pyelonephritis-associated pili (Pap) expression in uropathogenic Escherichia coli is regulated by a complex phase variation mechanism involving the competition between leucine-responsive regulatory protein (Lrp) and DNA adenine methylase (Dam). Population dynamics of pap gene expression has been studied extensively and the detailed molecular mechanism has been largely elucidated, providing sufficient information for mathematical modeling. Although the Gillespie algorithm is suited for modeling of stochastic systems such as the pap operon, it becomes computationally expensive when detailed molecular steps are explicitly modeled in a population. Here we developed a Markov Chain model to simplify the computation. Our model is analytically derived from the molecular mechanism. The model presented here is able to reproduce results presented using the Gillespie method, but since the regulatory information is incorporated before simulation, our model runs more efficiently and allows investigation of additional regulatory features. The model predictions are consistent with experimental data obtained in this work and in the literature. The results show that pap expression in uropathogenic E. coli is initial-state-dependent, as previously reported. However...

Modeling of the Role of a Bax-Activation Switch in the Mitochondrial Apoptosis Decision

Chen, Chun; Cui, Jun; Lu, Haizhu; Wang, Rui; Zhang, Shuai; Shen, Pingping
Fonte: Biophysical Society Publicador: Biophysical Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.14%
We performed in silico modeling of the regulatory network of mitochondrial apoptosis through which we examined the role of a Bax-activation switch in governing the mitochondrial apoptosis decision. Two distinct modeling methods were used in this article. One is continuous and deterministic, comprised of a set of ordinary differential equations. The other, carried out in a discrete manner, is based on a cellular automaton, which takes stochastic fluctuations into consideration. We focused on dynamic properties of the mitochondrial apoptosis regulatory network. The roles of Bcl-2 family proteins in cellular responses to apoptotic stimuli were examined. In our simulations, a self-amplification process of Bax-activation is indicated. Further analysis suggests that the core module of Bax-activation is bistable in both deterministic and stochastic models, and this feature is robust to noise and wide ranges of parameter variation. When coupling with Bax-polymerization, it forms a one-way-switch, which governs irreversible behaviors of Bax-activation even with attenuation of apoptotic stimulus. Together with the growing biochemical evidence, we propose a novel molecular switch mechanism embedded in the mitochondrial apoptosis regulatory network and give a plausible explanation for the all-or-none...

A Top-Down Approach to Mechanistic Biological Modeling: Application to the Single-Chain Antibody Folding Pathway

Hildebrandt, Scott; Raden, David; Petzold, Linda; Robinson, Anne Skaja; Doyle, Francis J.
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.14%
A top-down approach to mechanistic modeling of biological systems is presented and exemplified with the development of a hypothesis-driven mathematical model for single-chain antibody fragment (scFv) folding in Saccharomyces cerevisiae by mediators BiP and PDI. In this approach, model development starts with construction of the most basic mathematical model—typically consisting of predetermined or newly-elucidated biological behavior motifs—capable of reproducing desired biological behaviors. From this point, mechanistic detail is added incrementally and systematically, and the effects of each addition are evaluated. This approach follows the typical progression of experimental data availability in that higher-order, lumped measurements are often more prevalent initially than specific, mechanistic ones. It also necessarily provides the modeler with insight into the structural requirements and performance capabilities of the resulting detailed mechanistic model, which facilitates further analysis. The top-down approach to mechanistic modeling identified three such requirements and a branched dependency-degradation competition motif critical for the scFv folding model to reproduce experimentally observed scFv folding dependencies on BiP and PDI and increased production when both species are overexpressed and promoted straightforward prediction of parameter dependencies. It also prescribed modification of the guiding hypothesis to capture BiP and PDI synergy.

Modeling Transmembrane Transport through Cell Membrane Wounds Created by Acoustic Cavitation

Zarnitsyn, Vladimir; Rostad, Christina A.; Prausnitz, Mark R.
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.14%
Cells exposed to acoustic cavitation and other mechanical stresses can be transiently permeabilized to permit intracellular uptake of molecules, including drugs, proteins, and genes. Microscopic imaging and other studies suggest that intracellular loading occurs through plasma membrane wounds of submicrometer radius that reseal over time through the aggregation and fusion of lipid vesicles trafficked to the wound site. The goal of this study was to 1), determine the size of membrane wounds as a function of time after in vitro sonication of DU145 prostate cancer cells under conditions that caused extensive acoustic cavitation; and 2), theoretically model transport processes leading to intracellular loading. Our overall hypothesis was that intracellular loading is governed by passive diffusion through porous membrane wounds of up to 300-nm radius containing pores that permit entry of molecules up to at least 28-nm radius over a timescale of minutes. Experimental measurements showed intracellular loading of molecules with radii from 0.6 to 28 nm, where most loading occurred after sonication over a timescale up to minutes and where smaller molecules were taken up to a greater extent and over a longer timescale than larger molecules. Theoretical modeling predicted that membrane wounds would have a 300-nm radius initially and then would shrink...

Delivery of Monoclonal Antibodies Through the Lymphatics: Characterization by Compartmental Modeling

Covell, David G.; Steller, Michael A.; Parker, Robert J.; Weinstein, John N.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 13/11/1985 EN
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36.14%
To investigate the effectiveness of subcutaneous administration for targeting antibody to lymph nodes we have used data on the kinetics of anti-H-2Kk antibody in Kk-positive and Kk-negative mice to construct a compartmental model of antibody biodistribution. Modeling analysis revealed that antibody injected subcutaneously into negative mice leaves the injection site via convection of material in newly formed lymph, rapidly enters the nodes of the lymphatic chain and finally enters the bloodstream, presumably by the thoracic duct. A small fraction of lymph is shunted around the popliteal nodes (25%) and around the lumbar nodes (15%). The kinetics of antibody injected subcutaneously into positive mice are defined largely by the binding of antibody to nearby cells. As a result of such binding, antibody is retained in the foot and the popliteal and lumbar nodes. The modeling analysis predicts dose-dependent kinetics: increasing dose results in increased uptake in the nodes. Doses that saturate the nodes can be expected to appear in the blood, thus increasing systemic toxicity and reducing signal to noise ratio.

Biophysically Based Mathematical Modeling of Interstitial Cells of Cajal Slow Wave Activity Generated from a Discrete Unitary Potential Basis

Faville, R.A.; Pullan, A.J.; Sanders, K.M.; Koh, S.D.; Lloyd, C.M.; Smith, N.P.
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: Artigo de Revista Científica
Publicado em 17/06/2009 EN
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36.14%
Spontaneously rhythmic pacemaker activity produced by interstitial cells of Cajal (ICC) is the result of the entrainment of unitary potential depolarizations generated at intracellular sites termed pacemaker units. In this study, we present a mathematical modeling framework that quantitatively represents the transmembrane ion flows and intracellular Ca2+ dynamics from a single ICC operating over the physiological membrane potential range. The mathematical model presented here extends our recently developed biophysically based pacemaker unit modeling framework by including mechanisms necessary for coordinating unitary potential events, such as a T-Type Ca2+ current, Vm-dependent K+ currents, and global Ca2+ diffusion. Model simulations produce spontaneously rhythmic slow wave depolarizations with an amplitude of 65 mV at a frequency of 17.4 cpm. Our model predicts that activity at the spatial scale of the pacemaker unit is fundamental for ICC slow wave generation, and Ca2+ influx from activation of the T-Type Ca2+ current is required for unitary potential entrainment. These results suggest that intracellular Ca2+ levels, particularly in the region local to the mitochondria and endoplasmic reticulum, significantly influence pacing frequency and synchronization of pacemaker unit discharge. Moreover...

Stochastic Modeling of Calcium in 3D Geometry

Mazel, Tomáš; Raymond, Rebecca; Raymond-Stintz, Mary; Jett, Stephen; Wilson, Bridget S.
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: Artigo de Revista Científica
Publicado em 04/03/2009 EN
Relevância na Pesquisa
36.14%
Release of inflammatory mediators by mast cells in type 1 immediate-hypersensitivity allergic reactions relies on antigen-dependent increases in cytosolic calcium. Here, we used a series of electron microscopy images to build a 3D reconstruction representing a slice through a rat tumor mast cell, which then served as a basis for stochastic modeling of inositol-trisphosphate-mediated calcium responses. The stochastic approach was verified by reaction-diffusion modeling within the same geometry. Local proximity of the endoplasmic reticulum to either the plasma membrane or mitochondria is predicted to differentially impact local inositol trisphosphate receptor transport. The explicit consideration of organelle spatial relationships represents an important step toward building a comprehensive, realistic model of cellular calcium dynamics.

Dealing with Diversity in Computational Cancer Modeling

Johnson, David; McKeever, Steve; Stamatakos, Georgios; Dionysiou, Dimitra; Graf, Norbert; Sakkalis, Vangelis; Marias, Konstantinos; Wang, Zhihui; Deisboeck, Thomas Steve
Fonte: Libertas Academica Publicador: Libertas Academica
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.14%
This paper discusses the need for interconnecting computational cancer models from different sources and scales within clinically relevant scenarios to increase the accuracy of the models and speed up their clinical adaptation, validation, and eventual translation. We briefly review current interoperability efforts drawing upon our experiences with the development of in silico models for predictive oncology within a number of European Commission Virtual Physiological Human initiative projects on cancer. A clinically relevant scenario, addressing brain tumor modeling that illustrates the need for coupling models from different sources and levels of complexity, is described. General approaches to enabling interoperability using XML-based markup languages for biological modeling are reviewed, concluding with a discussion on efforts towards developing cancer-specific XML markup to couple multiple component models for predictive in silico oncology.

Predicting the Impact of Vaccination on the Transmission Dynamics of Typhoid in South Asia: A Mathematical Modeling Study

Pitzer, Virginia E.; Bowles, Cayley C.; Baker, Stephen; Kang, Gagandeep; Balaji, Veeraraghavan; Farrar, Jeremy J.; Grenfell, Bryan T.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.14%
Background: Modeling of the transmission dynamics of typhoid allows for an evaluation of the potential direct and indirect effects of vaccination; however, relevant typhoid models rooted in data have rarely been deployed. Methodology/Principal Findings We developed a parsimonious age-structured model describing the natural history and immunity to typhoid infection. The model was fit to data on culture-confirmed cases of typhoid fever presenting to Christian Medical College hospital in Vellore, India from 2000–2012. The model was then used to evaluate the potential impact of school-based vaccination strategies using live oral, Vi-polysaccharide, and Vi-conjugate vaccines. The model was able to reproduce the incidence and age distribution of typhoid cases in Vellore. The basic reproductive number (R0) of typhoid was estimated to be 2.8 in this setting. Vaccination was predicted to confer substantial indirect protection leading to a decrease in the incidence of typhoid in the short term, but (intuitively) typhoid incidence was predicted to rebound 5–15 years following a one-time campaign. Conclusions/Significance: We found that model predictions for the overall and indirect effects of vaccination depend strongly on the role of chronic carriers in transmission. Carrier transmissibility was tentatively estimated to be low...