Mostrando recursos 1 - 20 de 55

  1. Entrando no Interior da Escola: etnografia e entrevistas etnográficas

    Vieira, Ricardo; Vieira, Ana
    Neste texto, depois de procurarem desconstruir a falsa oposição binária qualitativo-quantitativo, propondo um politeísmo metodológico, os autores centram-se nos paradigmas hermenêuticos e fenomenológicos, onde inscrevem a etnografia como abordagem que pode recorrer a diversas técnicas no sentido de compreender os sentidos que os atores sociais atribuem às suas práticas. Num segundo momento, mostram como a etnografia e a particularidade das entrevistas etnográficas são uma forma de aceder compreensivamente à dimensão interior da escola, buscando e construindo com os sujeitos sentidos e significados que as abordagens sistémicas têm descurado e transformado na caixa negra da instituição escolar.

  2. Stress responses of the sea cucumber Holothuria forskali during aquaculture handling and transportation

    Tonn, Nina; Novais, Sara C.; Silva, Cátia S. E.; Morais, Hugo A.; Correia, João P. S.; Lemos, Marco F. L.
    Animal welfare during handling and transportation to aquaculture facilities or public aquaria is commonly estimated by addressing injury and mortality levels. Although these procedures have been optimized for different species, data on individual species’ cellular capabilities to tolerate stress are still scarce. In the present study, several biomarkers related with oxidative stress and energy metabolism were assessed in Holothuria forskali during animal acclimation, pre-transport, transport and quarantine. Combined analyses confirmed that sea cucumbers experienced high oxidative stress during transport, but had the capability to deal with it using a complex of cellular defence mechanisms, which enabled recovery from oxidative stress...

  3. Using biomarkers to address the impacts of pollution on limpets ( Patella depressa ) and their mechanisms to cope with stress

    Silva, Cátia S. E.; Novais, Sara C.; Simões, Tiago; Caramalho, Márcia; Gravato, Carlos; Rodrigues, Maria J.; Maranhão, Paulo; Lemos, Marco F. L.
    Contaminant discharges, derived from human activities, are major concerns as they exert a continuous ecological pressure on aquatic systems, causing in fact cascading community effects. Although with associated ecological and fitness costs, physiological and biochemical defense mechanisms may restore the organism’s internal balance. Several studies have pointed biomarkers as tools to assess contamination levels, and also to understand potential mechanisms to cope with stress. In the present study, the fitness costs of limpets Patella depressa located in two different contaminated sites and when transplanted into a different common environment – with no known historical contamination – were assessed through the...

  4. Reproductive trade-offs in a temperate reef fish under high pCO2 levels

    Faria, A. M.; Lopes, A. F.; Silva, C. S. E.; Novais, S. C.; Lemos, M. F. L.; Gonçalves, E. J.
    Fishes are currently facing novel types of anthropogenic stressors that have never experienced in their evolutionary history, such as ocean acidification. Under these stressful conditions, energetically costly processes, such as reproduction, may be sacrificed for increased chances of survival. This trade-off does not only affect the organism itself but may result in reduced offspring fitness. In the present study, the effects of exposure to high pCO2 levels were tested on the reproductive performance of a temperate species, the two-spotted goby, Gobiusculus flavescens. Breeding pairs were kept under control (∼600 μatm, pH∼ 8.05) and high pCO2 levels (∼2300 μatm, pH∼ 7.60) conditions for...

  5. Polyphenols for an increased ability to cope with environmental toxicants

    Lagoa, Ricardo; Marques-da-Silva, Dorinda; Ribeiro, Vânia
    info:eu-repo/semantics/publishedVersion

  6. Light field image Coding using high-order intrablock prediction

    Monteiro, Ricardo J. S.; Nunes, Paulo J. L.; Rodrigues, Nuno M. M.; Faria, Sergio M. M. de
    This paper proposes a two-stage high-order intrablock prediction method for light field image coding. This method exploits the spatial redundancy in lenslet light field images by predicting each image block, through a geometric transformation applied to a region of the causal encoded area. Light field images comprise an array of microimages that are related by complex geometric transformations that cannot be efficiently compensated by state-of-the-art image coding techniques, which are usually based on low-order translational prediction models. The two-stage nature of the proposed method allows us to choose the order of the prediction model most suitable for each block, ranging...

  7. Sand smelt ability to cope and recover from ocean's elevated CO 2 levels

    Silva, Cátia S. E.; Lemos, Marco F. L.; Faria, Ana M.; Lopes, Ana F.; Mendes, Susana; Gonçalves, Emanuel J.; Novais, Sara C.
    Considered a major environmental concern, ocean acidification has induced a recent research boost into effects on marine biodiversity and possible ecological, physiological, and behavioural impacts. Although the majority of literature indicate negative effects of future acidification scenarios, most studies are conducted for just a few days or weeks, which may be insufficient to detect the capacity of an organism to adjust to environmental changes through phenotypic plasticity. Here, the effects and the capacity of sand smelt larvae Atherina presbyter to cope and recover (through a treatment combination strategy) from short (15 days) and long-term exposure (45 days) to increasing pCO2...

  8. Effects of ocean acidification on the swimming ability, development and biochemical responses of sand smelt larvae

    Silva, Cátia S. E.; Novais, Sara C.; Lemos, Marco F. L.; Mendes, Susana; Oliveira, Ana P.; Gonçalves, Emanuel J.; Faria, Ana M.
    Ocean acidification, recognized as a major threat to marine ecosystems, has developed into one of the fastest growing fields of research in marine sciences. Several studies on fish larval stages point to abnormal behaviours, malformations and increased mortality rates as a result of exposure to increased levels of CO2. However, other studies fail to recognize any consequence, suggesting species-specific sensitivity to increased levels of CO2, highlighting the need of further research. In this study we investigated the effects of exposure to elevated pCO2 on behaviour, development, oxidative stress and energy metabolism of sand smelt larvae, Atherina presbyter. Larvae were caught...

  9. Ownership structure and performance: evidence from Portugal

    Lisboa, Inês; Esperança, José Paulo
    This paper provides new evidence on the impact of ownership over performance in small dimension markets. Analyzing the Portuguese firms we confirm the monitoring effect. Unlike previous studies, we also confirm the expropriation effect to low levels of ownership concentration. These results suggest that the free rider problem between the manager and the principal is significant in countries with small financial markets.

  10. Empresa familiar y bolsa: análisis de rentabilidad y estrategias de inversión

    Miralles-Marcelo, José Luís; Miralles-Quirós, Maria del Mar; Lisboa, Inês
    The objective of this study is to analyze return differences between family and non-family firms quoted on the Spanish stock market over the 1999-2008 period. Furthermore, we compare risk exposure for these kinds of firms; the abnormal profits that may be obtained with a zero cost trading strategy based on being long in family firms and short in non-family firms; and the founder and size effects on performance. Our main results indicate the possibility of gaining abnormal profits trading on small family firms and selling non-family firms. We also observe a significant higher beta risk for family businesses directly managed...

  11. The stock performance of family firms in the Portuguese market

    Miralles-Marcelo, José Luís; Miralles-Quirós, Maria del Mar; Lisboa, Inês
    The aim of this study is to analyse the stock performance of family firms from 1999 to 2008 in the Portuguese stock market, where these kinds of firms are frequently found. Consistent with previous research, we employ a methodology based on a portfolio formation approach. Furthermore, we study the performance of individual stocks using a panel data analysis. Our findings show that family firms outperform nonfamily ones, especially those family firms of smaller size. These results are relevant for investors, academics and the professional managers of these companies.

  12. The impact of family control on firm performance: evidence from Portugal and Spain

    Miralles-Marcelo, José Luís; Miralles-Quirós, Maria del Mar; Lisboa, Inês
    This study aims to assess performance differences between family and non-family firms, taking into account the Portuguese and the Spanish stock markets. We provide new evidence for this field since we take into account the heterogeneity among family firms. Our thesis is that the leadership of family firms, and the firm's size and age are moderators of the relationship between family control and firm performance. Using a panel data methodology, our main results show that family firms, especially the smaller and older, exhibit at least the same performance as non-family firms. Based on the results of the study, who manages...

  13. Family impact on capital structure: does financial crisis matter?

    Lisboa, Inês
    This study analyses whether family control impacts the firm’s capital structure and if results are influenced by financial turbulences. Using a sample of Portuguese listed firms during fourteen years, results show that family and-non family firms have different debt levels in periods of expansion. Moreover, the higher concentration of family ownership leads to reduction in the firm’s leverage, especially in recession periods. These results confirm the behavioural-agency theory: the family looks to socio-emotional wealth but assuring the firm presence for future generations.

  14. Family firm’s heterogeneity and firm risk

    Lisboa, Inês; Miralles-Quirós, Maria del Mar
    The behavioral agency theory suggests that family firms present less risk than non-family firms to protect their socioemotional wealth. Most studies analyzing this field focus on the bank sector or the US economy. This study aims to examine whether there are differences in risk between family and non-family firms using Portuguese listed firms during fourteen years. Moreover we provide new evidence taking into account firms’ heterogeneities. Family and non-family firms are not homogeneous groups and the firm’s growth opportunities, age and size can be moderators of the relationship between family control and firm risk. We also analyze the effect on...

  15. Does family control reduce firm risk?

    Miralles-Marcelo, José Luís; Miralles-Quirós, Maria del Mar; Lisboa, Inês
    In the current context of instability and financial crisis, understanding firm risk is crucial. In this study we aim to assess firm risk differences between family and non-family firms. Furthermore we analyze the family control impact, measured by both the family ownership and the F-PEC scale, in firm risk. We provide new evidence from family firm studies since we not only analyze the risk topic, almost unexplored, but we also introduce the F-PEC scale, an alternative way to measure the family influence. Using Portuguese quoted firms during the 1999-2012 period, we find that family influence and control do not impact...

  16. Financial crisis and capital structure determinants: a study of Portuguese listed firms

    Lisboa, Inês
    Firm’s capital structure is not a new theme but is still relevant in financial literature. This work aims to go a step further, not only because the impact of financial crisis is analyzed, but also because stock repurchase is taken into account. First, the evolution of total, long-term, and short-term debt and loans is analyzed. Then capital structure is regressed against crisis, asset structure, non-debt tax shields, profitability, size, growth, liquidity, cash flow, age, debt serving capacity, own shares, and tax rate. Using an unbalance panel of 53 Portuguese firms from 2003 until 2015, and estimating the models with fixed...

  17. Does financial crisis impact earnings management evidence from Portuguese and UK

    Lisboa, Inês; Kacharava, Aleksandre
    Purpose: The main aim of this work is to analyse if 2008 financial crisis had impact on earnings management. We compare two countries with different legal forces in terms of quality of accounting to see the differences in firm’s involvement in earnings management. Finally we analyse which determinants impact management of results. Design/methodology/approach: This study focus on Portuguese and UK listed firms from a large period, 2004 till 2014. We first use the Kothari, Leone & Wasley model (2005) to calculate the discretionary accruals, a proxy of earnings management. Then we analyse the impact of six determinants on earnings management. Findings: Findings...

  18. Conceptualization of sustainable higher education institutions, roles, barriers, and challenges for sustainability: an exploratory study in Portugal

    Aleixo, Ana Marta; Leal, Susana; Azeiteiro, Ulisses
    Higher Education Institutions play an important role in the promotion of sustainability and an increasing number of stakeholders expect them to be sustainable organizations. However, this can only be achieved when barriers are faced and challenges overcome. This exploratory study aims to investigate how the main stakeholders (leaders, faculty, staff, students, and external stakeholders) of Portuguese Public Higher Education Institutions perceive: the concepts of sustainability and sustainable higher education institutions, the role of higher education for sustainable development, and the barriers, challenges and obstacles to implementing sustainable initiatives in Portuguese Public Higher Education Institutions. Through a qualitative approach, using semi-structured interviews and content analysis procedures, this article explore...

  19. The implementation of sustainability practices in Portuguese higher education institutions

    Aleixo, Ana Marta; Azeiteiro, Ulisses; Leal, Susana
    The purpose of this work is to analyze the current state of implementation of sustainability development (SD) in Portuguese higher education institutions (HEIs).

  20. Team practices in fall prevention in institutionalized elderly people: scale design and validation

    Baixinho, Cristina Rosa Soares Lavareda; Dixe, Maria dos Anjos
    Objective: determine and elaborate the psychometric characteristics of nursing team practices and develop a behavior scale for fall risk management in institutionalized elderly people. Method: the scale was designed based on a literature review and observation of the work of the teams in a long-term care institution for the elderly. The content of the scale was analyzed and the concordance index of the 14 initial items was checked by nine experts. The scale was applied to a sample of 152 caregivers from six long-term care institutions for the elderly. The research conformed to ethical principles. The anonymity of the participants and the confidentiality of the...

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