Embedded model discrepancy: A case study of Zika modeling

Mathematical models of epidemiological systems enable investigation of and predictions about potential disease outbreaks. However, commonly used models are often highly simplified representations of incredibly complex systems. Because of these simplifications, the model output, of say new cases of a disease over time, or when an epidemic will occur, may be inconsistent with available data. In this case, we must improve the model, especially if we plan to make decisions based on it that could affect human health and safety, but direct improvements are often beyond our reach. In this work, we explore this problem through a case study of the Zika outbreak in Brazil in 2016. We propose an embedded discrepancy operator---a modification to the model equations that requires modest information about the system and is calibrated by all relevant data. We show that the new enriched model demonstrates greatly increased consistency with real data. Moreover, the method is general enough to easily apply to many other mathematical models in epidemiology.Comment: 9 pages, 7 figure

Problemas inversos para identificação de parâmetros em sistemas dinâmicos

International audienc

Stock selection based on cluster analysis

We put forward a technique based on cluster analysis to group stocks in spot markets according to a risk-return criterion. We show how an informed investor will make money using the cluster analysis to select stocks of major companies from North and South America.

A data-driven approach for inference of the evolution equation of a Duffing oscillator

International audienceAs more and more data is available on a daily basis, it is natural to seek to infer relevant information embedded in these datasets. In the context of dynamical systems, this idea translates into the use of observations (data) to infer the evolution law. I this sense, machine learning techniques are getting more space in the analysis and synthesis of dynamical systems. This paper uses regularized data-driven regression algorithm to infer the evolution law of a Duffing oscillator, using a library of mathematical functions obtained from a dataset generated from the underlying physical system

Growth cycles in Latin America and developed countries

The Minskyan approach to financial instability and its effects on the real economy have recently been revived in order to explain the exchange rate crises undergone by the so-called emergent economies. Economies of this type are characterized by repeated scarcity of foreign currency, which can be explained by using Neo-Schumpeterian theory. Based on the Minskyan approach and on the Neo-Schumpeterian literature, this study seeks to demonstrate that there is a cyclic recurrence of exchange rate crises in Latin-American (peripheral) economies. By using data on international liquidity, the balance of payments and the increase in production in the G7 economies and in thirteen Latin-American economies, it was found that the Latin-American economies mirror the cycles of international liquidity.financial instability, national innovation system, cycles

Sensitivity Analysis in Zika Virus Dynamics and a Model Discrepancy Approach

International audienc

An interleukin-33/ST2 signaling deficiency reduces overt pain-like behaviors in mice

Interleukin (IL)-33, the most recent member of the IL family of cytokines, signals through the ST2 receptor. IL-33/ST2 signaling mediates antigen challenge-induced mechanical hyperalgesia in the joints and cutaneous tissues of immunized mice. The present study asked whether IL-33/ST2 signaling is relevant to overt pain-like behaviors in mice. Acetic acid and phenyl-p-benzoquinone induced significant writhing responses in wild-type (WT) mice; this overt nociceptive behavior was reduced in ST2-deficient mice. In an antigen-challenge model, ST2-deficient immunized mice had reduced induced flinch and licking overt pain-like behaviors. In the formalin test, ST2-deficient mice also presented reduced flinch and licking responses, compared with WT mice. Naive WT and ST2-deficient mice presented similar responses in the rota-rod, hot plate, and electronic von Frey tests, indicating no impairment of motor function or alteration in basal nociceptive responses. The results demonstrate that IL-33/ST2 signaling is important in the development of overt pain-like behaviors