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

Morphology and divisional morphogenesis of brackish water ciliate Novistrombidium rufinoi sp. nov. (Ciliophora: Oligotrichia) from Brazil

The strombidiid ciliate Novistrombidium rufinoi sp. nov. is described from observations on live and protargol-impregnated specimens. The organisms were isolated from samples of slightly brackish water from Cabiúnas Lagoon, located in Parque Nacional da Restinga de Jurubatiba, an environment conservation area in the northern region of the state of Rio de Janeiro, Brazil. The new species measures ~40 x 35 μm in vivo and differs from congeners by having a 7?11 μm long, adherent, non-retractile tail that lacks cilia and a conspicuously spring-shaped adoral zone which has two thigmotactic membranelles. Stomatogenesis in the opisthe is hypoapokinetal and parental oral apparatus is retained in the proter.Fil: Da Silva Paiva, Thiago. Universidade de Sao Paulo; BrasilFil: Kuppers, Gabriela Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Domingos da Silva Neto, Inácio. Universidade de Sao Paulo; Brasi

Bridging Science to Economy: The Role of Science and Technologic Parks in Innovation Strategies in “Follower” Regions

The concept of Regional Innovation System (RIS) builds upon an integrated perspective of innovation, acknowledging the contribution of knowledge production subsystem, regulatory context and enterprises to a region’s innovative performance. Science and Technology parks can act as a platform to the production of knowledge and its transfer to the economy in the form of spin-offs or simple knowledge spillovers, enhanced by the co-location of R&D university centers and high technology enterprises on site. Although reflecting mainly a science push perspective, they may constitute central nodes in an infrastructural system of competitiveness that articulates other entrepreneurial location sites and bridges Universities to the economy in a more efficient and effective way, being crucial to increasing technology transfer and interchange speed, promoting the technological upgrading of the regional economy. In this paper we discuss the importance of Science and Technology Parks in the building up of a Regional Innovation System, promoting the technological intensification of the economy, a more effective knowledge transfer and sharing and the construction of competitive advantages, with particular importance in follower regions facing structural deficiencies. We oppose to the predominant closed paradigm, which understands science parks’ role in a narrow and “enclavist”, arguing in favor of an open and “integrative” paradigm where the interconnection to other infrastructures and agents boosts the park’s performance and upgrades the regional economies competitiveness infra-structures and innovation capability. We further stress the importance of science parks in signaling capabilities and hence attracting R&D external initiatives, namely, R&D FDI.Science Parks, New technology-based firms, Innovation, Regional Policy

Training of industrial assembly processes: an immersive approach

This article reports about an Immersive Training System, integrated in a national R&D program,has been developed by CCG for the specific case of the wire twist assembly. It is based on real workplaces from specific industrial partners

A methodological approach to evaluate elderly-robot interactions

The relevance in the study of interaction between elderly and robots may depend on the choice of activities that robots can be developed to perform and the assessment of their impact and importance for older people. This research requires coordinated research between computer engineers and specialists in the humanities and social sciences. Being a recent research area, it is particularly relevant to carefully select the behavioural variables to be analyzed, the methodology adopted and the instruments that allow for a rigorous evaluation. Based on these assumptions, the present study aims to develop Innovative Initiatives for the Promotion of Active Aging in the EUROACE Region. The authors propose an appropriate methodology and instruments to evaluate the impact of the human-robot interaction in the promotion of a more active aging in a group of elderly in a nursing home. The analyzed variables focus on the involvement of the elderly in the activities, their capacity for initiative and to establish social interactions, indicators of well-being and a proactive attitude. The methodology of the study is mixed (qualitative and quantitative), organized as an exploratory case study. Data collection is based on naturalistic observation but variables are quantitatively assessed in a pre/post-test design. The research design identified the narratives of the elderly and the staff of the institution regarding the needs and interests of each elderly person, classified the participants according to the levels of prevailing social interactions, involvement and initiative in activities, considered important variables for an active ageing and, in this sense, demonstrated its adequacy to be used to evaluate the results of the intervention using social assistive robots.info:eu-repo/semantics/publishedVersio

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

A leitura digital – perceções de professores em formação

A proliferação de suportes tecnológicos em que a leitura é, hoje em dia, feita torna incontornável a sua utilização, reconhecendo-se o valor dos conteúdos digitais encerram face à leitura no tradicional suporte papel. Conscientes do papel que os professores dos primeiros anos de escolaridade desempenham na formação de hábitos de leitura, procurámos saber deque forma estes encaram a leitura em suporte digital (enquanto leitores e futuros docentes com responsabilidades na promoção desta competência junto dos seus alunos), atendendo à importância queesta assume no espaço educativo. Neste sentido, auscultámos estudantes dos mestradosem formação de professores de uma Escola Superior de Educação do norte de Portugal. Foi selecionada uma amostra por conveniência de 15 estudantes, os quais responderam a um inquérito por questionário estruturado em 20 questões visando recolher dados sobre: i) Caracterização dos inquiridos (Perfil de leitor e de utilizador de TIC); ii) Auto-perceção quanto a hábitos e valoração da leitura em suporte digital e impresso; Os inquiridos declaram atribuir muita importância à leitura, reconhecendo-se maioritariamente como leitores entusiastas. Apesar de se identificarem como utilizadores intensivos de notebooke tablet, privilegiam a leitura em suporte impresso em detrimento do suporte digital, quer em termos de frequência absoluta, quer quando discriminados os vários géneros textuai

Wear behavior of glass-ceramic and polymer-infiltrated ceramic materials for dental applications

Dissertação de mestrado integrado em Engenharia Biomédica (área de especialidade em Biomateriais, Reabilitação e Biomecânica)Wear of teeth and restorative materials has been often reported by general dental practitioners and researchers. Wear can occur at tooth-tooth, restoration-tooth, or restoration-restoration contacting surfaces, depending on the properties of the related synthetic and natural materials. All-ceramic restorations are the most popular type of dental restorations due to their optical and mechanical properties. However, the abrasiveness of ceramic materials results in progressive wear of contacting surfaces such as resin composite or tooth enamel. Concerning aaesthetics, strength, and wear, new glass ceramics and composites have been commercially introduced in the field of dentistry. The objective of the present work is to study the tribological behavior of a zirconia-reinforced lithium silicate glass-ceramic and a polymer-infiltrated ceramic. Samples were tested on a reciprocating ball-on-plate tribometer at 30 N applied load, 1 Hz and stroke length of 2 mm. The wear sliding tests were carried out against an alumina ball in artificial saliva at 37 ºC. Additionally, micro-scale abrasion tests were also performed in the presence of abrasive particles to simulate three-body abrasion conditions. The micro-scale abrasion tests were performed at 60 rpm with a normal load of 0.8 N for 600 revolutions of a stainless-steel ball in contact with a suspension of hydrated silica particles. After wear tests, the worn surfaces were inspected by scanning electron microscopy (SEM) and Energy-Dispersive Spectroscopy (EDS). The main wear mechanism found during the tests was abrasion. However, the hybrid ceramic, during the reciprocating tests, presented an unstable adhesive tribo-layer, associated with a delamination process. Congruently, the wear volume obtained during the micro-abrasion tests were higher for the polymer infiltrated ceramic than for the glass-ceramic, 1.44x10-1 mm3, and 9.89x10-2 mm3, respectively. The same happened to the specific wear rate for sliding tests where the hybrid ceramic obtained 5.33x10-5 mm3/N.m and the glass-ceramic 3.17x10-5 mm3/N.m. For all test conditions, zirconia reinforced glass-ceramic, presented higher wear resistance than hybrid ceramic, combined with lower friction coefficient against alumina, which indicates the potential of this reinforced glass-ceramic for application in dental restorations.O desgaste dos dentes e materiais de restauro, tem sido referenciado muitas vezes por médicos dentistas e investigadores. O desgaste pode ocorrer na interação de superfícies em contacto, dente-dente, restauro-dente, ou mesmo restauro-restauro, dependendo das propriedades dos materiais sintéticos e naturais. Os restauros totalmente cerâmicos são o tipo mais popular de restauros dentários, devido às suas propriedades óticas e mecânicas. No entanto, a abrasividade dos materiais cerâmicos resulta no desgaste progressivo das superfícies em contacto como resinas compósitas ou esmalte dentário. Tendo em conta a estética, resistência e desgaste, novos vitrocerâmicos e compósitos têm sido introduzidos no campo da dentária. O objetivo do presente trabalho é o estudo do comportamento tribológico de um vitrocerâmico de silicato de lítio reforçado com zircónia e de uma cerâmica infiltrada com polímero. As amostras foram testadas num tribómetro esfera-placa em deslizamento linear alternativo, com uma carga aplicada de 30 N, 1 Hz e 2 mm de amplitude. Estes testes foram realizados contra uma esfera de alumina em saliva artificial a 37 ºC. Além disso, foram realizados testes de abrasão em micro-escala, na presença de partículas abrasivas para simular condições de abrasão a três corpos. Os testes de micro-abrasão foram realizados a 60 rpm e com uma carga normal fixa de 0,8 N para 600 rotações da esfera em aço, usando uma suspensão de sílica hidratada. Após os testes tribológicos, as superfícies desgastadas foram inspecionadas por microscopia eletrónica de varrimento (SEM) e por espetroscopia de energia dispersiva (EDS). O principal mecanismo de desgaste encontrado durante os ensaios foi a abrasão. Porém, o cerâmico hibrido, apresentou uma tribo-camada adesiva e instável, associada a um processo de delaminação. Congruentemente, o volume de desgaste obtido durante os testes de microabrasão foi maior para o cerâmico infiltrado com polímero do que para o vitrocerâmico, 1,44x10-1 mm3 e 9,89x10-2 mm3, respetivamente. O mesmo aconteceu com a taxa de desgaste específica para testes de deslizamento em que a cerâmica híbrida resultou em 5,33x10-5 mm3/N.m e a vitrocerâmica 3,17x10-5 mm3/N.m. Para todas as condições de teste, o vitrocerâmico reforçado com zircónia apresentou maior resistência ao desgaste do que o cerâmico híbrido, combinando com menor coeficiente de atrito contra a alumina, o que indica o potencial de aplicação deste vitrocerâmico reforçado em restaurações dentárias.This work was supported by the Portuguese Foundation of Science and Technology through the projects: POCI-01-0145-FEDER-006941 and UID/EEA/04436/201