Dynamics of Dengue epidemics using optimal control

We present an application of optimal control theory to Dengue epidemics. This epidemiologic disease is an important theme in tropical countries due to the growing number of infected individuals. The dynamic model is described by a set of nonlinear ordinary differential equations, that depend on the dynamic of the Dengue mosquito, the number of infected individuals, and the people's motivation to combat the mosquito. The cost functional depends not only on the costs of medical treatment of the infected people but also on the costs related to educational and sanitary campaigns. Two approaches to solve the problem are considered: one using optimal control theory, another one by discretizing first the problem and then solving it with nonlinear programming. The results obtained with OC-ODE and IPOPT solvers are given and discussed. We observe that with current computational tools it is easy to obtain, in an efficient way, better solutions to Dengue problems, leading to a decrease of infected mosquitoes and individuals in less time and with lower costs.Comment: Submitted to Mathematical and Computer Modelling 25/Oct/2009; accepted for publication, after revision, 22/June/201

Numerical analysis of a nonlocal parabolic problem resulting from thermistor problem

We analyze the spatially semidiscrete piecewise linear finite element method for a nonlocal parabolic equation resulting from thermistor problem. Our approach is based on the properties of the elliptic projection defined by the bilinear form associated with the variational formulation of the finite element method. We assume minimal regularity of the exact solution that yields optimal order error estimate. The full discrete backward Euler method and the Crank-Nicolson-Galerkin scheme are also considered. Finally, a simple algorithm for solving the fully discrete problem is proposed

The Thirring interaction in the two-dimensional axial-current-pseudoscalar derivative coupling model

The authors reexamine the two-dimensional model of massive fermions interacting with a massless pseudoscalar field via axial-current-pseudoscalar derivative coupling. Performing a canonical field transformation on the Bose field algebra the model is mapped into the Thirring model with an additional vector-current-scalar-derivative interaction (Schroer-Thirring model). The complete bosonized version of the model is presented. The bosonized composite operators of the quantum Hamiltonian are obtained as the leading operators in the Wilson short distance expansion.Comment: 13 page

Videogames, gamification e ensino de línguas no Pibid: teoria e prática

Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014O uso de tecnologias como ferramenta auxiliadora em diversas práticas sociais tem sido cada vez mais recorrente. Neste contexto, os videogames e a teoria de Gamification têm sido constantemente mencionados. Assim objetivamos apresentar os pressupostos teórico-metodológicos da teoria de Gamification e do uso de Massive Multiplayer Online Games (MMOs) e discutir como esses pressupostos podem apresentar contribuições para o ensino de línguas, apresentando uma lista de critérios sobre esses pressupostos teórico-metodológicos para a produção de videogames no ensino de línguas (uma das propostas do PIBID de Letras-Inglês). Esta discussão embasa as propostas em andamento com o uso de videogames para o ensino de línguas do subprojeto do PIBID de Letras- Inglê

Bs∗BKB_s^* B K vertex from QCD sum rules

The form factors and the coupling constant of the $B_s^* B K$ vertex are calculated using the QCD sum rules method. Three point correlation functions are computed considering both $K$ and $B$ mesons off-shell and, after an extrapolation of the QCDSR results, we obtain the coupling constant of the vertex. We study the uncertainties in our result by calculating a third form factor obtained when the $B^*_s$ is the off-shell meson, considering other acceptable structures and computing the variations of the sum rules' parameters. The form factors obtained have different behaviors but their simultaneous extrapolations reach to the same value of the coupling constant $g_{B_s^* B K}=10.6 \pm 1.7$. We compare our result with other theoretical estimates.Comment: 11 pages, 11 figure

Growth performance, in vitro antioxidant properties and chemical composition of the halophyte Limonium algarvense Erben are strongly influenced by the irrigation salinity

Limonium algarvense Erben (sea lavender) is a halophyte species with potential to provide natural ingredients with in vitro antioxidant, anti-inflammatory, neuroprotective and antidiabetic properties. This study reports for the first time the 1) cultivation of sea lavender in greenhouse conditions under irrigation with freshwater (approx. 0 mM NaCl) and saline aquaculture wastewater (300 and 600 mM NaCl), and 2) the influence of the irrigation salinity on the plant performance (e.g growth, number of produced leaves and flowers), in vitro antioxidant properties [radical scavenging activity (DPPH and ABTS), ferric reducing antioxidant power (FRAP), metal chelating properties on copper (CCA) and iron (ICA)], toxicity (in vitro on three mammalian cell lines) and chemical composition (determined by LC-ESI-HRMS/MS). The freshwater-irrigated plants had better growth performance than those irrigated with saltwater. Extracts from wild plants, had the highest antioxidant activity, but those from cultivated ones kept high in vitro antioxidant properties and interesting chemical profile. The flowers' extracts of plants irrigated with 300 mM NaCl had the highest antioxidant activities against DPPH, whereas those from freshwater-irrigated plants were more active on ABTS, CCA and FRAP. Most of the extracts showed nil toxicity. The flowers' extracts displayed the highest diversity of compounds, mainly quercetin, apigenin, luteolin, naringenin and their glycoside derivatives. Moreover, their abundance varied with the irrigation salinity. These data indicate that sea lavender plants can be successfully cultivated in greenhouse conditions under fresh- and saltwater irrigation, maintaining interesting biological and chemical properties.Funding Agency Portuguese Foundation for Science and Technology Portuguese National Budget CCMAR/Multi/04326/2019 GreenVet project ALG-01-0145-FEDER-028876 XtrerneAquaCrops FA-05-2017-028 Lisboa-01-0145-FEDER-022125-RNEM-IST ID/QUI/00100/201 Portuguese Foundation for Science and Technology SFRH/BD/116604/2016 CEECIND/00425/2017info:eu-repo/semantics/publishedVersio

Stability of methylphenidate under various ph conditions in the presence or absence of gut microbiota

Methylphenidate is one of the most widely used oral treatments for attention-deficit/hyperactivity disorder (ADHD). The drug is mainly absorbed in the small intestine and has low bioavailability. Accordingly, a high interindividual variability in terms of response to the treatment is known among ADHD patients treated with methylphenidate. Nonetheless, very little is known about the factors that influence the drug’s absorption and bioavailability. Gut microbiota has been shown to reduce the bioavailability of a wide variety of orally administered drugs. Here, we tested the ability of small intestinal bacteria to metabolize methylphenidate. In silico analysis identified several small intestinal bacteria to harbor homologues of the human carboxylesterase 1 enzyme responsible for the hydrolysis of methylphenidate in the liver into the inactive form, ritalinic acid. Despite our initial results hinting towards possible bacterial hydrolysis of the drug, up to 60% of methylphenidate is spontaneously hydrolyzed in the absence of bacteria and this hydrolysis is pH-dependent. Overall, our results indicate that the stability of methylphenidate is compromised under certain pH conditions in the presence or absence of gut microbiota

Avaliação de genótipos de feijão-caupi, de porte semi prostrado e prostrado, na Região Norte.

Vinte genótipos de feijão-caupi de porte prostrado e semi prostrado, sendo seis cultivares e 14 linhagens, provenientes do Programa de Melhoramento da Embrapa Meio Norte, utilizados nos ensaios avançados de porte prostrado e semi prostrado (EAP) foram avaliados no período de maio a agosto de 2010, 2011 e 2012 nos municípios de Bragança, Traquateua, Paragominas e Salvaterra, no Estado do Pará, e Carutapera, no Estado do Maranhão. O objetivo do trabalho foi identificar genótipos com potencial de cultivo para essas regiões. O ensaio foi conduzido no delineamento experimental de blocos ao acaso, com 20 tratamentos e quatro repetições. Os genótipos MNCO2-701F-2, BRS PINGO DE OURO-1-2 e MNCO3-736F-6 foram os que apresentaram as maiores produtividades de grãos, com 1699,0 kg ha-1, 1612,6 kg ha-1 e 1606,0 kgha-1, respectivamente, diferindo estatisticamente do genótipo BRS Juruá, com produtividade de 1228,7 kg ha-1. Os genótipos testados expressaram o mesmo potencial produtivo nos cinco ambientes testados. Todos os genótipos de feijão-caupi avaliados apresentaram potencial para cultivo na região Nort

Piecewise-linear controller synthesis with applications to inventory control of switched production systems

This paper focuses on the problem of inventory control of production systems. The main contribution of the paper is that production systems are modeled as constrained switched linear systems and the inventory control problem is formulated as a constrained switched H∞ problem with a piecewise-affine (PWA) control law. The switching variable for the production systems modeled in this paper is the stock level. When the stock level is positive, some of the perishable produced parts are being stored and will deteriorate with time at a given rate. When the stock level is negative it leads to backorders, which means that orders for production of parts are coming in and there are no stocked parts to immediately meet the demand. A state feedback controller that forces the stock level to be kept close to zero (sometimes called a just-in-time policy), even when there are fluctuations in the demand, will be designed in this paper using H∞ control theory. The synthesis of the state feedback controller that quadratically stabilizes the production dynamics and at the same time rejects the external demand fluctuation (treated as a disturbance) is cast as a set of linear matrix inequalities (LMIs). Two numerical examples are provided to show the effectiveness of the proposed metho