110 research outputs found
Gathering Computational Genomics and Proteomics to Unravel Adaptive Evolution
A recent editorial in PLoS Biology by MacCallum and Hill (2006) pointed out the inappropriateness of studies evaluating signatures of positive selection based solely in single-site analyses. Therefore the rising number of articles claiming positive selection that have been recently published urges the question of how to improve the bioinformatics standards for reliably unravel positive selection? Deeper integrative efforts using state-of-the-art methodologies at the gene-level and protein-level are improving positive selection studies. Here we provide some computational guidelines to thoroughly document molecular adaptation
Impactos das Distorções Tributárias sobre a Determinação da Oferta de Trabalho
Usando um modelo de crescimento neoclássico, Prescott (2004) e Ohanian et alii (2008) explicam com sucesso as diferenças de horas trabalhadas entre países da OCDE. Aplicamos este mesmo modelo para o caso brasileiro entre 1988 e 1998. Nossa principal conclusão é que esta metodologia falha em explicar a experiência brasileira. O modelo prevê, como consequência do aumento de impostos verificado no período, uma queda substancial no número de horas trabalhadas. Entretanto, os dados mostram apenas uma leve queda. Utilizamos, ainda, especificações alternativas para a preferência do agente representativo, as quais tornam a oferta de trabalho menos sensível a impostos. Entretanto, o ajuste aos dados é satisfatório apenas para parâmetros bastante distantes daqueles utilizados pela literatura internacional. Sugerimos que a presença significativa de um setor informal pode explicar a especificidade brasileira.Oferta de trabalho, Tributação
Barriers and incentives to territory-based innovation processes: from technology to interaction among actors
The context of territory-based innovation processes includes both barriers and incentives. This chapter presents and discusses the research and findings of a study conducted with two sets of five community-led initiatives, one composed of small-sized initiatives and another composed of larger-sized initiatives, with a view to identify barriers and incentives to territory-based innovation. Following a mixed-coding approach, data was analysed to identify barriers and incentives to territory-based innovation prompted by the use of digital tools, by the interaction among actors, and by contextual factors. Results from both small- and larger-sized initiatives show significant technology weariness, still initiatives praise the effectiveness of some digital tools, namely social media, in reaching their audience. Both types of initiatives, especially small-sized ones, evidence disappointment towards cultural traits and bureaucracy, being these factors experienced as a disheartening barrier. Yet, initiatives also commend the know-how and flexibility of specific actors, e.g. civil parishes, with whom initiatives interact with closely when performing their day-to-day activities.publishe
Coordinated waves of actomyosin flow and apical cell constriction immediately after wounding
We are grateful for funding from Fundacao para a Ciencia e a Tecnologia (SFRH/BD/41884/2007), Human Frontier Science Program (RGP/2007), and European Research Council (2007-StG-208631).Epithelial wound healing relies on tissue movements and cell shape changes. Our work shows that, immediately after wounding, there was a dramatic cytoskeleton remodeling consisting of a pulse of actomyosin filaments that assembled in cells around the wound edge and flowed from cell to cell toward the margin of the wound. We show that this actomyosin flow was regulated by Diaphanous and ROCK and that it elicited a wave of apical cell constriction that culminated in the formation of the leading edge actomyosin cable, a structure that is essential for wound closure. Calcium signaling played an important role in this process, as its intracellular concentration increased dramatically immediately after wounding, and down-regulation of transient receptor potential channel M, a stress-activated calcium channel, also impaired solin, protein, also impaired the wound response, indicating that cleaving the existing actin filament network is an important part of the cytoskeleton remodeling process.publishersversionpublishe
Developing a digital platform for community-led initiatives: from local agents′ needs to interface design
To identify how digital media are being used by community-led initiatives of the Centro Region of Portugal, and to identify the requirements that a digital platform for mediation between agents in the territory should have, two focus groups were conducted, involving six small-sized community-led initiatives and six larger-sized community-led initiatives. This article details the results of these focus groups, according to the following main categories: use of existing communication and mediation tools; the purpose of use of digital tools; type of experiences prompted by digital tools and attributes and features desired in a digital platform to support community-led initiatives. The results show differences between the use and needs of digital tools by small- and larger-sized initiatives and offer interesting insights to prototype an innovative digital solution, to enhance the actions of community-led initiatives. A reference framework for digital mediation strategies and a mobile app prototype were developed, based on these surveys. The article contributes with an analytical view about the development of digital solutions, which aim to strengthen the relationship among agents of local communities and promote mediation mechanisms among all stakeholders in territorial-based innovation.Programa Operacional Regional do Centro (CENTRO 2020), PT2020publishe
Digital platforms audiovisual culture and memory: the case of film festivals in the North and Northeast of Brazil
Este artigo tem como objetivo discutir o papel das plataformas digitais na preservação da memória e no registro de informação ligada aos festivais de cinema para os utilizadores. O estudo baseia-se na sistematização de festivais de cinema realizados regularmente nas regiões Norte e Nordeste do Brasil e analisa as plataformas digitais integradas (sites, páginas do Facebook, blogs etc.) a cada festival. Os dados analisados foram extraídos da Agência Nacional de Cinema (ANCINE) e do Guia Kinoforum. A amostra final mapeou 66 festivais ou exposições de filmes em todos os nove estados da região Nordeste e 12 eventos em seis estados da região Norte. A netnografia foi utilizada como método para analisar ambientes digitais que hospedam informações sobre os festivais de cinema, considerando para esse fim quatro categorias de análise: atualização de conteúdo, mecanismos de busca, tipos de interação e elementos de memória. O fornecimento de informações on-line demonstrou que a mídia digital ainda é subutilizada por festivais e promotores de cinema, principalmente devido ao uso elementar dos recursos das plataformas digitais.This paper aims at discussing the role of digital platforms in preserving memory and in recording
information related to film festivals to users. The study is based on the systematization of film festivals
that are held on a regular basis in the North and Northeast regions of Brazil and reviews the integrated
digital platforms (websites, Facebook pages, blogs etc.) of each festival. Data analyzed was retrieved
from the National Film Agency (ANCINE) and the Kinoforum Guide. Final sample mapped 66 film
festivals or exhibitions in all nine states of the Northeast region and 12 events in six states of the North
region. Netnography was used as a method to analyze digital environments that host information about
the film festivals, considering for that purpose, four categories of analysis: updating content, search
resources, types of interaction and elements of memory. The provision of online information
demonstrated that digital media is still underutilized by festivals and cinema promoters, mainly due to
an elementary use of digital platforms resources.publishe
The adaptive evolution of the mammalian mitochondrial genome
<p>Abstract</p> <p>Background</p> <p>The mitochondria produce up to 95% of a eukaryotic cell's energy through oxidative phosphorylation. The proteins involved in this vital process are under high functional constraints. However, metabolic requirements vary across species, potentially modifying selective pressures. We evaluate the adaptive evolution of 12 protein-coding mitochondrial genes in 41 placental mammalian species by assessing amino acid sequence variation and exploring the functional implications of observed variation in secondary and tertiary protein structures.</p> <p>Results</p> <p>Wide variation in the properties of amino acids were observed at functionally important regions of cytochrome <it>b </it>in species with more-specialized metabolic requirements (such as adaptation to low energy diet <it>or </it>large body size, such as in elephant, dugong, sloth, and pangolin, and adaptation to unusual oxygen requirements, for example diving in cetaceans, flying in bats, and living at high altitudes in alpacas). Signatures of adaptive variation in the NADH dehydrogenase complex were restricted to the loop regions of the transmembrane units which likely function as protons pumps. Evidence of adaptive variation in the cytochrome <it>c </it>oxidase complex was observed mostly at the interface between the mitochondrial and nuclear-encoded subunits, perhaps evidence of co-evolution. The ATP8 subunit, which has an important role in the assembly of F<sub>0</sub>, exhibited the highest signal of adaptive variation. ATP6, which has an essential role in rotor performance, showed a high adaptive variation in predicted loop areas.</p> <p>Conclusion</p> <p>Our study provides insight into the adaptive evolution of the mtDNA genome in mammals and its implications for the molecular mechanism of oxidative phosphorylation. We present a framework for future experimental characterization of the impact of specific mutations in the function, physiology, and interactions of the mtDNA encoded proteins involved in oxidative phosphorylation.</p
Promoting community-based networks through digital media
Digital media can provide an essential contribution to the development of local communities by creating digital environments that facilitate the sharing of information, dissemination of knowledge, and construction of organizational learning. Digital media can also promote interaction and collaboration processes among different regional agents, fostering a continuous flow of territorial-based innovation. The study reported in this paper was carried out within the research activities of the CeNTER project, aiming to deepen the knowledge about the conditions that influence the dynamics of community-led territorial-based innovation in the Centro Region of Portugal, focusing on the areas of Tourism, Health, and Wellbeing. As part of this project, a mobile application is being designed, aiming to strengthen the relationship among agents of local communities/entities and to promote mediation mechanisms among all stakeholders in the process of territorial-based innovation. This paper presents the main concepts underlying the development of the CeNTER application and the outcomes from a usability evaluation of the mobile app prototype. The first section discusses the most relevant topics that this paper covers. In the second section, an overview of the theoretical background in digital media used to promote territory-based innovation is presented. The third section describes the concept of the CeNTER application and the main features of the prototype/mobile app. The fourth section addresses the methodology adopted for evaluating the prototype and the fifth presents the main outcomes of this process. Finally, the sixth and final section presents the main conclusions about the potential of the CeNTER application, and current and future research activities.publishe
Compositional trends in tourmalines from granites and quartz-tourmaline rocks from the Penamacor-Monsanto pluton (Eastern Central Portugal)
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