Cox process representation and inference for stochastic reaction-diffusion processes

Complex behaviour in many systems arises from the stochastic interactions of spatially distributed particles or agents. Stochastic reaction-diffusion processes are widely used to model such behaviour in disciplines ranging from biology to the social sciences, yet they are notoriously difficult to simulate and calibrate to observational data. Here we use ideas from statistical physics and machine learning to provide a solution to the inverse problem of learning a stochastic reaction-diffusion process from data. Our solution relies on a non-trivial connection between stochastic reaction-diffusion processes and spatio-temporal Cox processes, a well-studied class of models from computational statistics. This connection leads to an efficient and flexible algorithm for parameter inference and model selection. Our approach shows excellent accuracy on numeric and real data examples from systems biology and epidemiology. Our work provides both insights into spatio-temporal stochastic systems, and a practical solution to a long-standing problem in computational modelling

Anais do V Encontro Brasileiro de Educomunicação: Educação midiática e políticas públicas

A presente coletânea, que chega ao público através de um suporte digital, tem como objetivo disponibilizar os papers, bem como os relatos de experiências educomunicativas apresentados durante o V ENCONTRO BRASILEIRO DE EDUCOMUNICAÇÃO, que teve como tema central: “Educação Midiática e Políticas Públicas”. O evento foi realizado em São Paulo, entre 19 e 21 de setembro de 2013, a partir de uma parceria entre o NCE/USP - Núcleo de Comunicação e Educação da USP, a Licenciatura em Educomunicação da ECA/USP, a ABPEducom – Associação Brasileira de Pesquisadores e Profissionais da Educomunicação e a FAPCOM – Faculdade Paulus de Tecnologia e Comunicação, que ofereceu seu campus, na Vila Mariana, para os atos do evento. Os presentes anais disponibilizam o texto de abertura, de autoria do coordenador geral do evento, denominado “Educação midiática e políticas públicas: vertentes históricas da emergência da Educomunicação na América Latina”. Na sequência, apresentam 61 papers sobre aspectos específicos da temática geral, resultantes de pesquisas na área, seguidos de 27 relatos de práticas educomunicativas, em nível nacional

Nonlinear reactive processes in constrained media

In this thesis we show how reactive processes can be affected by the presence of different types of spatial constraints, so much so that their nonlinear dynamics can be qualitatively altered or that new and unexpected behaviors can be produced. To understand how this interplay can occur in general terms, we theoretically investigate four very different examples of this situation. The first system we study is a reversible trimolecular chemical reaction which is taking place in closed one-dimensional lattices. We show that the low dimensionality may or may not prevent the reaction from reaching its equilibrium state, depending on the microscopic properties of the molecular reactive mechanism. The second reactive process we consider is a network of biological interactions between pigment cells on the skin of zebrafish. We show that the combination of short-range and long-range contact-mediated feedbacks can promote a Turing instability which gives rise to stationary patterns in space with intrinsic wavelength, without the need of any kind of motion.Then we investigate the behavior of a typical chemical oscillator (the Brusselator) when it is constrained in a finite space. We show that molecular crowding can in such cases promote new nonlinear dynamical behaviors, affect the usual ones or even destroy them. Finally we look at the situation where the constraint is given by the presence of a solid porous matrix that can react with a perfect gas in an exothermic way. We show on one hand that the interplay between reaction, heat flux and mass transport can give rise to the propagation of adsorption waves, and on the other hand that the coupling between the chemical reaction and the changes in the structural properties of the matrix can produce sustained chemomechanical oscillations. These results show that spatial constraints can affect the kinetics of reactions, and are able to produce otherwise absent nonlinear dynamical behaviors. As a consequence of this, the usual understanding of the nonlinear dynamics of reactive systems can be put into question or even disproved. In order to have a better understanding of these systems we must acknowledge that mechanical and structural feedbacks can be important components of many reactive systems, and that they can be the very source of complex and fascinating phenomena.Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Pigment cell movement is not required for generation of Turing patterns in zebrafish skin

© 2015 Macmillan Publishers Limited. The zebrafish is a model organism for pattern formation in vertebrates. Understanding what drives the formation of its coloured skin motifs could reveal pivotal to comprehend the mechanisms behind morphogenesis. The motifs look and behave like reaction-diffusion Turing patterns, but the nature of the underlying physico-chemical processes is very different, and the origin of the patterns is still unclear. Here we propose a minimal model for such pattern formation based on a regulatory mechanism deduced from experimental observations. This model is able to produce patterns with intrinsic wavelength, closely resembling the experimental ones. We mathematically prove that their origin is a Turing bifurcation occurring despite the absence of cell motion, through an effect that we call differential growth. This mechanism is qualitatively different from the reaction-diffusion originally proposed by Turing, although they both generate the short-range activation and the long-range inhibition required to form Turing patterns.We acknowledge financial support by the Fonds David et Alice Van Buuren.Peer Reviewe

Nonlinear reactive processes in constrained media

In this thesis we show how reactive processes can be affected by the presence of different types of spatial constraints, so much so that their nonlinear dynamics can be qualitatively altered or that new and unexpected behaviors can be produced. To understand how this interplay can occur in general terms, we theoretically investigate four very different examples of this situation. The first system we study is a reversible trimolecular chemical reaction which is taking place in closed one-dimensional lattices. We show that the low dimensionality may or may not prevent the reaction from reaching its equilibrium state, depending on the microscopic properties of the molecular reactive mechanism. The second reactive process we consider is a network of biological interactions between pigment cells on the skin of zebrafish. We show that the combination of short-range and long-range contact-mediated feedbacks can promote a Turing instability which gives rise to stationary patterns in space with intrinsic wavelength, without the need of any kind of motion.Then we investigate the behavior of a typical chemical oscillator (the Brusselator) when it is constrained in a finite space. We show that molecular crowding can in such cases promote new nonlinear dynamical behaviors, affect the usual ones or even destroy them. Finally we look at the situation where the constraint is given by the presence of a solid porous matrix that can react with a perfect gas in an exothermic way. We show on one hand that the interplay between reaction, heat flux and mass transport can give rise to the propagation of adsorption waves, and on the other hand that the coupling between the chemical reaction and the changes in the structural properties of the matrix can produce sustained chemomechanical oscillations. These results show that spatial constraints can affect the kinetics of reactions, and are able to produce otherwise absent nonlinear dynamical behaviors. As a consequence of this, the usual understanding of the nonlinear dynamics of reactive systems can be put into question or even disproved. In order to have a better understanding of these systems we must acknowledge that mechanical and structural feedbacks can be important components of many reactive systems, and that they can be the very source of complex and fascinating phenomena.Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

LUCIFERIAN PROTO-INDIVIDUALISM IN TWO ADAPTATIONS OF THE FAUST LEGEND

(Statement of Responsibility) by Jasmine Johnson-Bullara(Thesis) Thesis (B.A.) -- New College of Florida, 2019RESTRICTED TO NCF STUDENTS, STAFF, FACULTY, AND ON-CAMPUS USE(Bibliography) Includes bibliographical references.This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.Faculty Sponsor: Sutherland, Wend

Nonlinear storage of solar energy

info:eu-repo/semantics/nonPublishe

La formazione continua come elemento moderatore tra le diverse e mutevoli esigenze della societ\ue0, delle imprese e degli individui

La formazione continua in Alto Adige e i luoghi della formazione - Misure di finanziamento e modelli integrati per l'occupabilit\ue

Estudo sobre a utilização das metodologias ativas na formação de jovens no ensino profissionalizante

As Metodologias Ativas de ensino e aprendizagem representam aumento das possibilidades para que o estudante atue de forma ativa na construção de seu conhecimento. A presente pesquisa exploratória e descritiva identificou e avaliou o uso delas sob a ótica dos professores atuantes do ensino profissionalizante em algumas unidades de uma instituição educacional de grande porte. Utilizou, para isso, a abordagem qualitativa com a aplicação de questionários aos docentes para a coleta de dados. Esse estudo assume relevância na medida em que essas práticas têm sido cada vez mais utilizadas nas últimas décadas nos cursos profissionalizantes como propulsor da formação do trabalhador frente às exigências do mercado de trabalho. Os resultados obtidos indicam a importância da utilização das metodologias ativas no ensino profissional para o desenvolvimento do aluno sob alguns aspectos, entre eles: desenvolvimento do processo reflexivo da aprendizagem, estímulo ao senso crítico, aproximação entre teoria e prática, motivação para a aprendizagem, instauração de bom clima afetivo, estimulando as interações aluno-aluno e aluno-professor, ampliação da autonomia do aluno frente a situações diversas que exigem tomada de decisão. Destaca-se a gameficação como a estratégia mais utilizada pelos professores entrevistados no emprego das Metodologias Ativas. Os resultados apontaram, por outro lado, que a utilização delas exige a necessária capacitação dos docentes e revelaram a existência de algumas dificuldades na implementação das metodologias ativas no processo de ensino e aprendizagem, tais como: o gap da formação acadêmica, a resistência para a quebra de paradigma de aluno espectador para aluno protagonista, a insuficiência das ações de treinamento e a inadequação ocasional da infraestrutura de trabalho. Considera-se que a investigação contribuirá significativamente para a melhoria das atividades de ensino, tanto para o educador ao aperfeiçoar suas técnicas de ensino, como para as unidades educacionais que colherão bons frutos pela sólida e perene formação de seus alunos.Active Teaching and Learning Methodologies represent an increase in the possibilities for students to act actively in the construction of their knowledge. This exploratory and descriptive research identified and evaluated their use from the perspective of teachers working in vocational education in some units of a large educational institution. For this, it used the qualitative approach with the application of questionnaires to teachers for data collection. This study assumes relevance to the extent that these practices have been increasingly used in the last decades in vocational courses as a driver of worker training in the face of the demands of the labor market. The results obtained indicate the importance of using active methodologies in professional education for the development of the student under some aspects, among them: development of the reflective learning process, stimulation of critical sense, approximation between theory and practice, motivation for learning, establishment of a good affective atmosphere, stimulating the student-student and student- interactions teacher, expansion of student autonomy in the face of diverse situations that require decision making. Gamification is highlighted as the strategy most used by teachers interviewed when using Learning Methodologies. The results showed, on the other hand, that the use of them requires the necessary training of teachers and revealed the existence of some difficulties in the implementation of active methodologies in the teaching and learning process, such as: the gap in academic training, the resistance to the paradigm break from a spectator student to a protagonist student, the insufficiency of training actions and the occasional inadequacy of the work infrastructure. It is considered that the investigation will contribute significantly to the improvement of teaching activities, both for the educator to improve his teaching techniques, and for the educational units that will reap good results for the solid and permanent training of their students