Skewness in Financial Returns: Evidence from the Portuguese Stock Market (in English)

This paper addresses the issue of symmetry in financial returns. The return distributions of the major stocks traded on the Portuguese market and included in the PSI-20 Index are examined for periods from four to nine years. The results show that the symmetry of the returns is rejected against several alternative distributions. Statistically significant differences between returns below and above the mean are detected, which provides additional evidence of skewness in the return distributions. In addition, as observed in other studies, it is interesting to note that such results are similar to other low-capitalization and low-volume markets, which also exhibit asymmetric return distributions.stock markets, skewness, financial returns

A abordagem de ligaçao química numa perspectiva de ensino por situação-problema

Esta investigação retrata um estudo realizado junto a estudantes do primeiro período do Curso de Licenciatura Plena em Química da Universidade Federal Rural de Pernambuco. Foi realizada uma intervenção didática utilizando uma situação-problema vinculada a instrumentos didáticos sobre ligação iônica e metálica. Ficou evidenciado que a utilização da situação-problema e dos instrumentos didáticos contribuiu para aprendizagem dos estudantes em relação aos aspectos conceituais relativos às ligações químicas

Arte e Saúde – Humanizando o Cuidado

Falar sobre a inter-relação entre Arte e Saúde é um desafio para mim enquanto docente e enfermeira envolvida com o cuidado em situações de ensino e em experiências pessoais enquanto filha, mãe, irmã, esposa e amiga de pessoas que vivenciam ou vivenciaram cotidianamente problemas de saúde e doença.Organização, execução e patrocínio: UNILA e Itaipu-Paraguay - Parceria: NELOOL/UFSC & Universidad de VIG

Are Price Limits on Futures Markets That Cool? Evidence from the Brazilian Mercantile and Futures Exchange

This paper investigates the impact of price limits on the Brazilian futures markets using high frequency data. The aim is to identify whether there is a cool-off or a magnet effect. For that purpose, we examine a tick-by-tick data set that includes all contracts on the S�o Paulo stock index futures traded on the Brazilian Mercantile and Futures Exchange from January 1997 to December 1999. The results indicate that the conditional mean features a floor cool-off effect, whereas the conditional variance significantly increases as the price approaches the upper limit. We then build a trading strategy that accounts for the cool-off effect in the conditional mean so as to demonstrate that the latter has not only statistical, but also economic significance. The in-sample Sharpe ratio indeed is way superior to the buy-and-hold benchmarks we consider, whereas out-of-sample results evince similar performances.Cool-off effect, Futures markets, Magnet effect, Price limits, Transactions data

Quality, Success, Communication and Contribution in Open Source Software

Free and open source software projects are often perceived to be of high quality. To a great extend the success of open source software seems to be due to an implicit but effective connection between communication and contributions in its development process. In this paper, we present a snapshot of the state the art on quality and success of Open Source Software (OSS) based on a review of the literature. For each of these concepts, we describe various measures considered in the literature and a number of methods by which they are obtained. Contributions to an Open Source Software (OSS) project are made through communication among developers and users. We elaborate on the concrete notions of communication and contribution in Open Source Software (OSS) and their links