Measuring complexity in a business cycle

The purpose of this paper is to study the dynamical behavior of a family of two- dimensional nonlinear maps associated to an economic model. Our objective is to measure the complexity of the system using techniques of symbolic dynamics in order to compute the topological entropy. The analysis of the variation of this im- portant topological invariant with the parameters of the system, allows us to distin- guish different chaotic scenarios. Finally, we use a another topological invariant to distinguish isentropic dynamics and we exhibit numerical results about maps with the same topological entropy. This work provides an illustration of how our under- standing of higher dimensional economic models can be enhanced by the theory of dynamical systems

Rheology of fractal networks

We model the cytoskeleton as a fractal network by identifying each segment with a simple Kelvin-Voigt element, with a well defined equilibrium length. The final structure retains the elastic characteristics of a solid or a gel, which may support stress, without relaxing. By considering a very simple regular self-similar structure of segments in series and in parallel, in 1, 2 or 3 dimensions, we are able to express the viscoelasticity of the network as an effective generalised Kelvin-Voigt model with a power law spectrum of retardation times, $\cal L\sim\tau^{\alpha}$. We relate the parameter $\alpha$ with the fractal dimension of the gel. In some regimes ($0<\alpha<1$), we recover the weak power law behaviours of the elastic and viscous moduli with the angular frequencies, $G'\sim G''\sim w^\alpha$, that occur in a variety of soft materials, including living cells. In other regimes, we find different power laws for $G'$ and $G''$.Comment: 5 pages, 3 figure

Chaotic behavior in an economic model

The purpose of this work is to study a discrete-time nonlinear business cycle model of the Kaldor-type. The model is an extended Kaldor model and it is described by a two-dimensional dynamical system with income and capital as variables. We check the orbits of the system, their changes related to changes of the system parameters and their basins of attraction in order to understand the dynamic features of the model

Curriculum materials as a learning tool for the teacher teaching mathematics.

Materiais curriculares configuram-se como instrumentos que (re)contextualizam as pr?ticas pedag?gicas, incidindo sobre os modos de ensinar e aprender Matem?tica. A pesquisa com foco na intera??o que ocorre entre professores e materiais curriculares tem chamando a aten??o para quest?es sobre como os profissionais utilizam os materiais de Matem?tica e se, e como, esses materiais podem influenciar as pr?ticas docentes. Nesse contexto, nos propomos a discutir sobre aspectos desses materiais que podem ajudar os professores a ampliar seus conhecimentos em rela??o ? Matem?tica para o ensino. Perpassando ?s ideias de affordance e ag?ncia, concentramos a discuss?o em torno de caracter?sticas nos materiais que podem promover as aprendizagens dos professores. Nesse sentido, tal discuss?o ser? feita na perspectiva de estudo te?rico, de abordagem qualitativa. Nossas reflex?es mostram que materiais curriculares, considerados como agentes de possibilidades para a pr?tica pedag?gica, podem apresentar recursos tais como transpar?ncia, antecipa??o das respostas dos estudantes, tipos de tarefas, bem como organiza??o e sequenciamento das situa??es de aprendizagem que podem contribuir para a mobiliza??o do conhecimento matem?tico para o ensino, por meio de uma an?lise cr?tica, podendo a rela??o e esta an?lise ser, inclusive, objetos da forma??o.Curriculum materials are instruments that (re)contextualize pedagogical practices, focusing on the ways of teaching and learning Mathematics. Research focusing on the interaction between teachers and curriculum materials has drawn attention to questions about how professional use Mathematics materials and whether, and how, these materials can influence teaching practices. In this context, we propose to discuss aspects of these materials that can help teachers broaden their knowledge of Mathematics for teaching. Going beyond the ideas of affordance and agency, we focused the discussion around characteristics in the materials that, in addition to promoting student learning, are designed to promote teacher learning. In this sense, such discussion will be made from the perspective of theoretical study, of qualitative approach. Our reflections show that curriculum materials considered as agents of possibilities for pedagogical practice can present resources such as transparency, anticipation of student responses, types of tasks, as well as organization and sequencing of learning situations that can contribute to the mobilization of knowledge mathematical for teaching, through a critical analysis, the relationship and this analysis being even objects of formation

Experiência parental frente ao diagnóstico do câncer infantil: uma compreensão à luz de Betty Neuman/ Parental experience in front of childhood cancer diagnosis: an understanding in the light of Betty Neuman

O estudo objetiva compreender as experiências de pais e mães de crianças diagnosticadas com câncer. Trata-se de um estudo de abordagem qualitativa e compreensiva na qual participaram 14 pais e mães de crianças em tratamento quimioterápico. Os dados coletados, por meio de grupo focal, aconteceram entre 10/01/2018 a 07/02/2018 e foram submetidos à análise de conteúdo proposta por Bardin. Os resultados apontaram para a criação três categorias: 1. Os estressores: em busca por resposta e a peregrinação pelos serviços de saúde; 2. Reação aos estressores:  Sentimentos frente ao diagnóstico do câncer; 3. A interação com o ambiente: Dogmas e estigmas sociais. Conclui-se que a falta de um diagnóstico precoce do câncer infantil leva os pais a uma árdua peregrinação pelos serviços de saúde e que com a confirmação diagnóstica os pais passam por intenso abalo psicológico, emocional e social

A Influência dos Aspectos Sociais na Competitividade das Redes Interorganizacionais: a Experiência da Rede dos Exportadores de Frango Halal Brasileiro

Inter-organizational networks are groups of legally independent organizations working together to achieve both their individual goals to the collective goals of the group. The focus of this research is the influence of social aspects on the competitiveness of inter-organizational networks, and the aim is to identify the contribution of the social aspects (strategy group, trust, commitment and cooperation) to the competitiveness of the network. It is about a qualitative, exploratory and descriptive study, through the case study of a single network of Brazilian poultry exporters of Halal. Primary data were collected through semi-structured interviews, in addition, the information obtained from these interviews were checked with information from other secondary sources such as reports and institutional materials. The results indicated that these social aspects are complementary and collaborate for a more competitive network. The contribution of this research indicates the existence of complementarities of the categories, wherein a positively reinforces the presence of another network.Redes interorganizacionais são grupos de organizações legalmente independentes que atuam em conjunto para alcançar seus objetivos individuais simultaneamente aos objetivos coletivos do grupo. O objeto de estudo desta pesquisa é a influência dos aspectos sociais na competitividade de redes interorganizacionais, e o objetivo é a identificação da contribuição dos aspectos sociais (estratégia de grupo, confiança, comprometimento e cooperação) para a competitividade da rede. Trata-se de uma pesquisa qualitativa, de natureza exploratória e descritiva, realizada por meio do estudo de caso único da rede dos exportadores de frango Halal brasileiro. Os dados primários foram coletados por meio de entrevistas semiestruturadas, além disso, as informações obtidas por meio dessas entrevistas foram checadas com informações de outras fontes secundárias, como relatórios e materiais institucionais. Os resultados indicaram que esses aspectos sociais são complementares e colaboram para uma maior competitividade da rede. A contribuição desta pesquisa aponta a existência da complementaridade das categorias, em que uma reforça positivamente a presença da outra na rede

Analysis of Parkinson disease patients from Portugal for mutations in SNCA, PRKN, PINK1 and LRRK2

Background: Mutations in the genes PRKN and LRRK2 are the most frequent known genetic lesions among Parkinson's disease patients. We have previously reported that in the Portuguese population the LRRK2 c.6055G > A; p.G2019S mutation has one of the highest frequencies in Europe.Methods: Here, we follow up on those results, screening not only LRRK2, but also PRKN, SNCA and PINK1 in a cohort of early-onset and late-onset familial Portuguese Parkinson disease patients. This series comprises 66 patients selected from a consecutive series of 132 patients. This selection was made in order to include only early onset patients (age at onset below 50 years) or late-onset patients with a positive family history (at least one affected relative). All genes were sequenced bi-directionally, and, additionally, SNCA, PRKN and PINK1 were subjected to gene dosage analysis.Results: We found mutations both in LRRK2 and PRKN, while the remaining genes yielded no mutations. Seven of the studied patients showed pathogenic mutations, in homozygosity or compound heterozygosity for PRKN, and heterozygosity for LRRK2.Conclusion: Mutations are common in Portuguese patients with Parkinson's disease, and these results clearly have implications not only for the genetic diagnosis, but also for the genetic counseling of these patients

Association of HFE common mutations with Parkinson's disease, Alzheimer's disease and mild cognitive impairment in a Portuguese cohort

Background: Pathological brain iron deposition has been implicated as a source of neurotoxic reactive oxygen species in Alzheimer (AD) and Parkinson diseases (PD). Iron metabolism is associated with the gene hemochromatosis (HFE Human genome nomenclature committee ID: 4886), and mutations in HFE are a cause of the iron mismetabolism disease, hemochromatosis. Several reports have tested the association of HFE variants with neurodegenerative diseases, such as AD and PD with conflicting results.Methods: Genotypes were analysed for the two most common variants of HFE in a series of 130 AD, 55 Mild Cognitive Impairment (MCI) and 132 PD patients. Additionally, a series of 115 healthy age-matched controls was also screened.Results: A statistically significant association was found in the PD group when compared to controls, showing that the presence of the C282Y variant allele may confer higher risk for developing the disease.Conclusion: Taken together these results suggest that the common variants in HFE may be a risk factor for PD, but not for AD in the Portuguese population

A Detailed Analysis of Oculomotor Function in 16 Patients with Spinocerebellar Ataxia Type 3 (SCA 3) (.pdf)

Oculomotor abnormalities in SCA 3 patients include the presence of square wave jerks (SWJ), saccade dysmetria, gaze-evoked nystagmus (GEN), positional nystagmus (pN), and caloric hyporreflexia. However, eye movement static and dynamic disconjugacy and high acceleration vestibular responses have been scarcely studied

Processos de ensino e aprendizagem matemática para a EJA mediados por materiais didáticos

Em nossa prática pedagógica, a Educação de Jovens e Adultos vem despertando nossas atenções, especialmente ao concebermos processos de ensino/mediação de aprendizagem matemática a partir de metodologias diferenciadas. Ao identificarmos nesses jovens e adultos alunos com particularidades e expectativas de aprendizagens significativas e que, por vezes, apresentam dificuldades para se apropriarem dos conceitos matemáticos, emergiu o desejo de estudarmos os materiais didáticos objetivando, para esses alunos, a construção do significado das técnicas “vai um” e “empresta” ao operarem os números naturais. Este artigo procura evidenciar nossas reflexões sobre as contribuições do material dourado nesse processo. Dentre os autores que sustentam nossas discussões destacam-se Lellis e Imenes (1994), Lorenzato (2006) e Januario (2008a, 2008b) – ao evidenciarem  as potencialidades dos materiais didáticos – e Ausubel (1976, 2003) – ao contribuir  com a teoria da Aprendizagem Significativa. Esperamos que, ao final da leitura, este texto possa conduzir o leitor à reflexão quanto à autonomia de cada aluno e à postura do professor ao propor situações de aulas diferenciadas