Two nonlinear systems from mathematical physics

The dissertation is divided into two chapters. In the first one, we consider the 2-Vortex problem for two point vortices in a complex domain. The Hamiltonian of the system contains the regular part of a hydrodynamic Green’s function, the Robin function h and two coefficinets which are the strengths of the point vortices. We prove the existence of infinitely many periodic solutions with minimal period T which are a superposition of a slow motion of the center of vorticity along a level line of h and of a fast rotation of the two vortices around their center of vorticity. These vortices move in a prescribed subset of the domain that has to satisfy a geometric condition. The minimal period can be any T in a certain interval. Subsets to which our results apply can be found in any generic bounded domain. The proofs are based on a recent higher dimensional version of the Poincaré-Birkhoff theorem due to Fonda and Ureña. In the second part, we study bifurcations of a multi-component Schrödinger system. We construct a solution branch synchronized to a positive solution of a simpler system. From this branch, we find a sequence of local bifurcation values in the one dimensional case and also in the general case provided that the positive solution is nondegenerate

Effectiveness of Automatic Formative Assessment for learning Mathematics in Higher Education

[EN] The health emergency due to COVID-19 has highlighted the need of new and flexible digital methodologies for learning and teaching Mathematics, which can support the individual student’s needs and help shape education. In this paper, we propose to use Automatic Formative Assessment (AFA) activities designed according to an innovative model, framed on the theories of formative assessment and feedback. The model includes: availability of the activities and multiple attempts; algorithmic questions; open mathematical answers; contextualized tasks; immediate and interactive feedback. We analyzed an experience using AFA in a blended module in Mathematics for 96 first-year students in Biotechnology. We collected data from the platform on grades and attempts of AFA activities and cross-checked them with the final exam grades. The results show that the feedback gained from AFA helped students improve their performance and supported them in the exam preparation. In light of these results, we can conclude that similar activities can be an effective solution to support students’ self-study during and after the pandemic.Barana, A.; Marchisio, M.; Sacchet, M. (2021). Effectiveness of Automatic Formative Assessment for learning Mathematics in Higher Education. En 7th International Conference on Higher Education Advances (HEAd'21). Editorial Universitat Politècnica de València. 1-8. https://doi.org/10.4995/HEAd21.2021.13030OCS1

As múltiplas genealogias de clownear-palhaçar

Este artigo apresenta as múltiplas genealogias clownescas como sendo imprescindíveis para a intensidade e a sobrevivência da arte de clownear-palhaçar. A partir da recusa da ideia de uma "única e verdadeira" origem, abre-se à possibilidade de conceber vários começos para os clowns-palhaços. O conceito de rizoma de Deleuze e Guattari permite a concepção de um tecido vivo de relações entre tempos, espaços e culturas que serve como nutriente de artistas e suas figuras cômicas através dos tempos

Os efeitos da licença maternidade sobre o salário e o emprego da mulher no Brasil

This paper aims to estimate the effects of maternity leave legislation in women’s wages and employment in Brazil. We analyze the impact of an increase in the leave period, which was raised from 12 weeks to 120 days, as prescribed by the Federal Constitution of 1998. According to the theoretical literature, the effect of the legislation is ambiguous. One should expect that the leave would have negative effects on labor demand to the extent that it raises labor costs. On the other hand, the legislation is expected to increase labor supply and can have positive effects on wages if it avoids that women leave the labor market each time they have a child, therefore increasing the firm-specific human capital of these workers. We use a simple difference-indifferences methodology applied to data from Pesquisa Mensal de Emprego between 1986 and 1991. We compare the changes in wages and employment between the periods before and after the 1988 Constitution of women in fertile ages (our treatment group) with those of two control groups: men at the same ages and women in non-fertile ages. The results show that the leave increase had no significant impact on wages. We also find no signs that the leave increase raised women’s retention in the labor market, even in the case of the more educated female workers. The results also show insignificant impact in women’s employment.licença maternidade, salário da mulher, emprego da mulher