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Search Results: 1 - 10 of 221206 matches for " Marisa C.; "
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Desenvolvimento de referencial teórico para um sistema de informa??es gerenciais (SIG) para parlamentares e assessores na Camara Legislativa do Distrito Federal: em busca de um modelo conceitual
Rocha, Marisa P. C.;
Ciência da Informa??o , 2003, DOI: 10.1590/S0100-19652003000300010
Abstract: we seek to develop a referential theoretical for a conceptual model by a support information system to the decision, social-technique-structured-analysis-based. so that, we have analyzed the internal and external factors to act on representatives' and assessors' performances in the legislative process. as result, we got the relations between organization, environment and data, represented graphically, in a conceptual model.
Ontologias, Taxonomia e Tesauros em Teoria de Sistemas e Sistemática Ontologías, Taxonomía e Tesauros em Teoria de Sistemas e Sistemática
Marisa Luvizutti C. Martinez
Informa??o & Informa??o , 2011, DOI: 10.5433/1981-8920.2011v16n2p202-206
Abstract:
Correla??o entre os níveis séricos de DDT e os títulos de anticorpos antidiftéricos em meninas
Costa,Marisa C. Lobo da;
Revista de Saúde Pública , 1979, DOI: 10.1590/S0034-89101979000100005
Abstract: diphtheric antibody titer and blood levels of ddt were determined in 28 female children in order to establish some possible correlation between the two. to measure the ddt level in the blood, the gas chromatographic method was employed; to titrate the antibodies, passive hemagglatination-inhition was performed. the presence of op'ddt and the amount of pp'ddt were statistically correlated to the titer, and a positive correlation was established by non-parametric statistical methods. the possible influence of ddt on the cyclic amp system of immune-active cells is discussed explaining these results.
Influence of Calcification Solution on in vitro Chitosan Mineralization
Beppu, Marisa M.;Santana, Cesar C.;
Materials Research , 2002, DOI: 10.1590/S1516-14392002000100008
Abstract: the influence of the calcification solution on the mineralization of chitosan membranes was analysed. two factors were studied: ph and chemical composition (excess of calcium or phosphate ions) of solutions. substrates (membranes) of chitosan underwent mineralization by soaking in calcification solutions for 7 days at 36.5 °c. as expected, sem-eds analyses demonstrated that higher ph and concentration of ions increases deposition, however, the morphology and composition of these deposits varies depending on which ion (phosphate or calcium) is in excess. larger spherical deposits are observed when a calcium-rich solution is used instead of a phosphate-rich one. in the latter, the interconnectivity of the inorganic and organic (matrix) phases is very different, suggesting a different mechanism of deposition for each situation.
O papel dos pais na execu??o de planos de carreira no Ensino Secundário: Perspectivas de pais e de estudantes
Carvalho,Marisa; Taveira,Maria Céu;
Análise Psicológica , 2010,
Abstract: the goals of this study are to assess parents’ role in the career choice implementation of children in high school, in the perspective of children and parents, and to conceptualize the vocational counselling in high school. this study continues a previous investigation on models of vocational interventions in portuguese secondary schools (pinto, taveira, & fernandes, 2003). through the method of grounded theory (cf. strauss & corbin, 1994, 1998) were investigated the perspectives of a total of 62 participants, by using a open question questionnaire (pinto, 2000). the results evidenced that parents may influence their children’s vocational development by the direct relation with them and by the indirect relation with others in the context. the participants recognize the parents’ role on their children career decision making and development through parental attitudes more or less directed, specific and intentional and concreteness of activities. the results show the need of expanding vocational interventions, taking into consideration the contexts of life and its role in the decision making and career development.
Influence of Calcification Solution on in vitro Chitosan Mineralization
Beppu Marisa M.,Santana Cesar C.
Materials Research , 2002,
Abstract: The influence of the calcification solution on the mineralization of chitosan membranes was analysed. Two factors were studied: pH and chemical composition (excess of calcium or phosphate ions) of solutions. Substrates (membranes) of chitosan underwent mineralization by soaking in calcification solutions for 7 days at 36.5 °C. As expected, SEM-EDS analyses demonstrated that higher pH and concentration of ions increases deposition, however, the morphology and composition of these deposits varies depending on which ion (phosphate or calcium) is in excess. Larger spherical deposits are observed when a calcium-rich solution is used instead of a phosphate-rich one. In the latter, the interconnectivity of the inorganic and organic (matrix) phases is very different, suggesting a different mechanism of deposition for each situation.
Effects of adaptive protective behavior on the dynamics of sexually transmitted infections
Michael A. L. Hayashi,Marisa C. Eisenberg
Quantitative Biology , 2015,
Abstract: Sexually transmitted infections (STIs) continue to present a complex and costly challenge to public health programs. The preferences and social dynamics of a population can have a large impact on the course of an outbreak as well as the effectiveness of interventions intended to influence individual behavior. In addition, individuals may alter their sexual behavior in response to the presence of STIs, creating a feedback loop between transmission and behavior. We investigate the consequences of modeling the interaction between STI transmission and prophylactic use with a model that links a Susceptible-Infectious-Susceptible (SIS) system to evolutionary game dynamics that determine the effective contact rate. The combined model framework allows us to address protective behavior by both infected and susceptible individuals. Feedback between behavioral adaptation and prevalence creates a wide range of dynamic behaviors in the combined model, including damped and sustained oscillations as well as bistability, depending on the behavioral parameters and disease growth rate. We found that disease extinction is possible for multiple regions where R0 > 1, due to behavior adaptation driving the epidemic downward, although conversely endemic prevalence for arbitrarily low R0 is also possible if contact rates are sufficiently high. We also tested how model misspecification might affect disease forecasting and estimation of the model parameters and R0. We found that alternative models that neglect the behavioral feedback or only consider behavior adaptation by susceptible individuals can potentially yield misleading parameter estimates or omit significant features of the disease trajectory.
Parameter identifiability and identifiable combinations in generalized Hodgkin-Huxley models
Olivia J. Walch,Marisa C. Eisenberg
Quantitative Biology , 2015,
Abstract: The use of Hodgkin-Huxley (HH) equations abounds in the literature, but the identifiability of the HH model parameters has not been broadly considered. Identifiability analysis addresses the question of whether it is possible to estimate the model parameters for a given choice of measurement data and experimental inputs. Here we explore the structural identifiability properties of a generalized form of HH from voltage clamp data. Through a scaling argument, we conclude that the steady-state gating variables are not identifiable from voltage clamp data, and then further show that their product together with the conductance term forms an identifiable combination. We additionally show that these parameters become identifiable when the initial conditions for each of the gating variables are known. The time constants for each gating variable are shown to be identifiable, and a novel method for estimating them is presented. Finally, the exponents of the gating variables are shown to be identifiable in the two-gate case, and we conjecture these to be identifiable in the general case. These results are broadly applicable to models using HH-like formalisms, and show in general which parameters and combinations of parameters are possible to estimate from voltage clamp data.
Determining Structurally Identifiable Parameter Combinations Using Subset Profiling
Marisa C. Eisenberg,Michael A. L. Hayashi
Quantitative Biology , 2013,
Abstract: Identifiability is a necessary condition for successful parameter estimation of dynamic system models. A major component of identifiability analysis is determining the identifiable parameter combinations, the functional forms for the dependencies between unidentifiable parameters. Identifiable combinations can help in model reparameterization and also in determining which parameters may be experimentally measured to recover model identifiability. Several numerical approaches to determining identifiability of differential equation models have been developed, however the question of determining identifiable combinations remains incompletely addressed. In this paper, we present a new approach which uses parameter subset selection methods based on the Fisher Information Matrix, together with the profile likelihood, to effectively estimate identifiable combinations. We demonstrate this approach on several example models in pharmacokinetics, cellular biology, and physiology.
Modeling spatial transmission of Ebola in West Africa
Jeremy P D'Silva,Marisa C. Eisenberg
Quantitative Biology , 2015,
Abstract: The current epidemic of Ebola Virus Disease (EVD) in West Africa is the largest ever recorded, a fundamental shift in the epidemiology of Ebola with unprecedented spatiotemporal complexity. In this study, we used a spatial transmission model to understand spatiotemporal dynamics of EVD in West Africa, and to compare effectiveness of local interventions (e.g. case isolation, hospitalization) and long-range interventions (e.g. border closures). A compartmental spatial model was fitted to case and death incidence in each country. We evaluated the balance between local (within-country) and long-range (between-country) transmission, dependent on population sizes and distance between regions, using a gravity model. We also examined transmission dynamics between countries and the relative benefits of different interventions. We demonstrate that spatial spread patterns provide an explanation for dynamic patterns observed in early data from the epidemic, at both country and regional levels. In particular, the gravity model successfully captures the multiple waves of epidemic growth in Guinea by incorporating spatial interactions. The model simulations suggest that local transmission reductions were most effective in Liberia, while long-range transmission was dominant in Sierra Leone. The model is successfully able to simultaneously forecast cases and deaths one month ahead in all three countries. To conclude, the gravity model approach accurately captures and forecasts the patterns of spatial spread of EVD between countries in West Africa. The model structure and intervention analysis presented here provide information that can be used by policymakers and public health officials to help guide planning and response efforts for this and future epidemics.
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