Improved corporate governance: market reaction and liquidity implications

We study the market price reaction and liquidity impact that firms experience when they are incorporated into the differentiated corporate governance listing segments of the Sao Paulo Stock Exchange. The Brazilian market is of special interest since it allows us to analyze the effect of improved governance while keeping the market microstructure unchanged. The market price reaction is positive and significant when a firm announces its decision to commit to greater transparency and minority shareholder protection. We also find that shares with voting rights experience a stronger price reaction than non-voting shares.Corporate governance, Emerging markets, Event study, Liquidity costs, Special segments

Molecular analysis of anterior endoderm during Xenopus development: a funtional and genomic approach

Tese de doutoramento em Biologia (Biologia do Desenvolvimento), apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2008Fundação para a Ciência e Tecnologia (FCT), (SFHR/BD/10035/2002

Cerberus is a feedback inhibitor of Nodal asymmetric signaling in the chick embryo

The TGF-beta-related molecule Nodal plays an essential and conserved role in left-right patterning of the vertebrate embryo. Previous reports have shown that the zebrafish and mouse Cerberus-related proteins Charon and Cerberus-like-2 (Cerl-2), respectively, act in the node region to prevent the Nodal signal from crossing to the right side, whereas chick Cerberus (cCer) has an unclear function in the left-side mesoderm. In this study, we investigate the transcriptional regulation and function of cCer in left-right development. By analyzing the enhancer activity of cCer 5' genomic sequences in electroporated chick embryos, we identified a cCer left-side enhancer that contains two FoxH1 and one SMAD binding site. We show that these Nodal-responsive elements are necessary and sufficient for the activation of transcription in the left-side mesoderm. In transgenic mouse embryos, cCer regulatory sequences behave as in chick embryos, suggesting that the cis-regulatory sequences of Cerberus-related genes have diverged during vertebrate evolution. Moreover, our findings from cCer overexpression and knockdown experiments indicate that cCer is a negative-feedback regulator of Nodal asymmetric signaling. We propose that cCer and mouse Cerl-2 have evolved distinct regulatory mechanisms but retained a conserved function in left-right development, which is to restrict Nodal activity to the left side of the embryo.info:eu-repo/semantics/publishedVersio

Computational model of the LGMD neuron for automatic collision detection

In many animal species it is essential to recognize approach predators from complex, dynamic visual scenes and timely initiate escape behavior. Such sophisticated behaviours are often achieved with low neuronal complexity, such as in locusts, suggesting that emulating these biological models in artificial systems would enable the generation of similar complex behaviours with low computational overhead. On the other hand, artificial collision detection is a complex task that requires both real time data acquisition and important features extraction from a captured image. In order to accomplish this task, the algorithms used need to be fast to process the captured data and then perform real time decisions. Taking into account the previous considerations, neurorobotic models may provide a foundation for the development of more effective and autonomous devices/robots, based on an improved understanding of the biological basis of adaptive behavior. In this paper, we make a comparative analysis between the new computational model of a locust looming-detecting pathway and the model previously proposed by us. The obtained results proved the improvement provided by the pixel remapping in the model performance

Avaliação de desempenho de fundos de obrigações com base em modelos não condicionais versus modelos condicionais : evidência para o mercado Norte Americano

Dissertação de mestrado em FinançasOs métodos de avaliação do desempenho de fundos de investimento têm sido alvo de bastante discussão na literatura financeira, que advém da incerteza que caracteriza os mercados financeiros e da necessidade de estes incorporem essa incerteza, de forma a obter estimativas de desempenho o mais fiáveis possível. Ao longo desta tese proponho-me avaliar o desempenho de fundos de obrigações “Corporate” Norte Americanos, confrontando os resultados obtidos através das metodologias tradicionais (não condicionais) com aqueles obtidos com a aplicação de metodologias condicionais de avaliação de desempenho. Proponho-me ainda apresentar e discutir as metodologias de avaliação de desempenho, desde a mais tradicional com base num modelo de um fator (medida de Jensen, 1968), a metodologias condicionais que incorporam variáveis de informação pública com o objectivo de captar a variabilidade do risco. Aplicando a medida de Jensen (1968) bem como o modelo de Ferson e Schadt (1996), à amostra de fundos para o período de janeiro de 1999 a junho de 2009, observamos resultados semelhantes aos já anteriormente obtidos noutros estudos, na medida em que os gestores dos fundos de investimento não conseguem superar o desempenho de mercado, obtendo maioritariamente desempenhos neutros ou negativos. Com a aplicação da metodologia condicional de avaliação de desempenho, observa-se uma diminuição da penalização do desempenho negativo dos gestores dos fundos de investimento. O modelo condicional apresenta ainda um maior poder explicativo do desempenho dos fundos. Foi observada evidência de risco variável ao longo do tempo, em particular em função da variável taxa de crescimento dos dividendos do índice de mercado.Performance evaluation of investment funds has been the subject of an intense debate in the financial literature. The uncertainty surrounding financial markets and the need to incorporate this uncertainty in the performance evaluation models, in order to obtain the most reliable performance estimates possible, has been pointed out as a major issue in this area. The purpose of this thesis is to evaluate the performance of "Corporate" North American bond funds, comparing the results obtained through unconditional models and conditional models of performance evaluation. We propose present and discuss performance evaluation methodologies, from traditional models based on a single factor (Jensen’s alpha), conditional models that incorporates public information variables in order to account for time-varying risk. Applying both measures to the sample of bond funds over the period from january 1999 to june 2009, we found evidence that is in line with previous studies, in the sense that mutual funds do not outperform the market, showing mostly neutral and negative performance. When the conditional model is applied, there is light reduction of the negative performance. Also the conditional model has greater explanatory power. Finally, there seems that risk is time-varying and dependent on the dividend yield of the market index

Modeling disinhibition within a layered structure of the LGMD neuron

Due to their relatively simple nervous system, insects are an excellent way through which we can investigate how visual information is acquired and processed in order to trigger specific behaviours, as flight stabilization, flying speed adaptation, collision avoidance responses, among others. From the behaviours previously mentioned, we are particularly interested in visually evoked collision avoidance responses. These behaviors are, by necessity, fast and robust, making them excellent systems to study the neural basis of behavior. On the other hand, artificial collision avoidance is a complex task, in which the algorithms used need to be fast to process the captured data and then perform real time decisions. Consequently, neurorobotic models may provide a foundation for the development of more effective and autonomous devices

Synthesis and biological evaluation of novel anti-cancer agents

Cancer is still one of the deadliest diseases worldwide despite the deep understanding of its etiology and efforts toward an early detection and the development of personalized therapeutic approaches. Thus, the development of novel molecules that maybe selectively inhibit the growth of cancer cells, avoid side effects and/or acquired resistance has long been the focus in chemotherapy. One such compounds, AM130 with the spiro[pyrrolidine-3, 3´-oxindole] moiety has shown antiproliferative and antimalarial activity. Here, we report the synthesis and the biological anitproliferative potential of this compound, as well as its mechanism of action in cancer cells. Viability assays were performed in ovarian, colorectal and breast carcinoma cell lines and normal human fibroblasts, allowing the characterization of the antiproliferative potential of AM130. Results showed that AM130 has a higher cytotoxic effect as well as higher selectivity for the ovarian carcinoma cell line. The observed antiproliferative activity was due to the induction of cell death by mitochondria-mediated apoptotic pathway and autophagy. DNA interaction studies demonstrated that AM130 interacts with DNA by groove-binding, however without causing genotoxicity or cell cycle arrest. In addition, AM130 showed a strong affinity to bovine serum albumin. Proteomics analysis revealed that the majority of the identified proteins are involved in apoptosis and stress response regulation, corroborating the previous results about ovarian carcinoma cells death

LGMD based neural network for automatic collision detection

Real-time collision detection in dynamic scenarios is a hard task if the algorithms used are based on conventional techniques of computer vision, since these are computationally complex and, consequently, time-consuming. On the other hand, bio-inspired visual sensors are suitable candidates for mobile robot navigation in unknown environments, due to their computational simplicity. The Lobula Giant Movement Detector (LGMD) neuron, located in the locust optic lobe, responds selectively to approaching objects. This neuron has been used to develop bio-inspired neural networks for collision avoidance. In this work, we propose a new LGMD model based on two previous models, in order to improve over them by incorporating other algorithms. To assess the real-time properties of the proposed model, it was applied to a real robot. Results shown that the LGMD neuron model can robustly support collision avoidance in complex visual scenarios.(undefined

Application of a Costing Methodology to Estimate Capital Costs of Solar Thermal Systems in Residential Portuguese Context

The concerns regarding the environmental damage require changes not only on how the energy is consumed but also how it is produced. The close relationship between energy use and the economic growth exposes the need for continuous monitoring of energy consumption, which cannot be achieved without assessing capital and operational costs from its conversion to end-use. Solar thermal systems offer few advantages over other renewable resources to meet the energy demand in the small-scale building sector. Solar-thermal technologies can play a leading role in meeting the decarbonisation targets set in Europe. The reports from the International Energy Agency (IEA) shows that solar heating has the potential to cover more than 16% of the low-temperature heat use in energy mix scenario. In Europe, this share might translate into 45% growth of the installed solar thermal capacity by 2020, setting a challenging target of 1 m2 of collector area installed per capita by 2020 and of 1.3 m2 by 2050. The main objective of the present work is to define a costing methodology able to estimate the capital cost of solar-thermal systems according to the system size and energy requirements of a specific residential building. The costing methodology consists of the derivation of a cost expression for each component by integrating thermodynamic and cost coefficients, adjusted for this kind of technology, and also taking into account real market data. The model was validated for a reference dwelling in Lisbon, with an occupation of 4 people with an estimated energy need of 2 037 kWh/year in terms of DHW. Results of the reference scenario show that is required at least 4 m2 of solar collector and the system cost ranges from 703.2€ per m2 to 763.2€ per m2, depending on the acceptable storage tank capacity

Phytoestrogens as Bioactive Compounds with Beneficial Effects for Human Health

Phytoestrogens, also called estrogens, are bioactive compounds original from plants. They are similar in structure and functionality to the estrogenic hormones in animals. It has been documented that these compounds have several effects on the human body, namely in terms of carbohydrate, protein, lipid and mineral metabolism. Some of the most known effects of these substances are related to their roles in the women’s reproductive system. The dietary phytoestrogens are present in vegetable sources, like some herbs, grains or fruits. Their structure is similar to that of estradiol, which can act in the body both as estrogenic or antiestrogenic. They are classified into the following categories: i) isoflavones, which are essentially present in legume beans, and particularly soy beans and soy products; ii) lignans, which are part of foods rich in dietary fibre, like cereal brans, beans, legumes or oilseeds; iii) coumestans, found in various beans sucg as plit peas, pinto beanso r lima beans, and also in alfafa and clover sprouts; iv) mycoestrogens, which are produced by moulds. Phytoestrogens can be used as human health enhancers, and have many documented beneficial effects on the human body. They are reported to diminish the incidence of some types of cancer, as well as to minimize menopausal symptoms and prevent osteoporosis. Also some benefits have been associated with the ingestion of these bioactive compounds and protection against cardiovascular diseases. Hence, this chapter aims at reviewing the scientific literature about the structure of PEs, as well as their natural sources and health effects.info:eu-repo/semantics/publishedVersio