999 resultados para Code Reuse


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Real-space grids are a powerful alternative for the simulation of electronic systems. One of the main advantages of the approach is the flexibility and simplicity of working directly in real space where the different fields are discretized on a grid, combined with competitive numerical performance and great potential for parallelization. These properties constitute a great advantage at the time of implementing and testing new physical models. Based on our experience with the Octopus code, in this article we discuss how the real-space approach has allowed for the recent development of new ideas for the simulation of electronic systems. Among these applications are approaches to calculate response properties, modeling of photoemission, optimal control of quantum systems, simulation of plasmonic systems, and the exact solution of the Schrödinger equation for low-dimensionality systems.

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The genetic code establishes the rules that govern gene translation into proteins. It was established more than 3.5 billion years ago and it is one of the most conserved features of life. Despite this, several alterations to the standard genetic code have been discovered in both prokaryotes and eukaryotes, namely in the fungal CTG clade where a unique seryl transfer RNA (tRNACAG Ser) decodes leucine CUG codons as serine. This tRNACAG Ser appeared 272±25 million years ago through insertion of an adenosine in the middle position of the anticodon of a tRNACGA Ser gene, which changed its anticodon from 5´-CGA-3´ to 5´-CAG-3´. This most dramatic genetic event restructured the proteome of the CTG clade species, but it is not yet clear how and why such deleterious genetic event was selected and became fixed in those fungal genomes. In this study we have attempted to shed new light on the evolution of this fungal genetic code alteration by reconstructing its evolutionary pathway in vivo in the yeast Saccharomyces cerevisiae. For this, we have expressed wild type and mutant versions of the C. albicans tRNACGA Ser gene into S. cerevisiae and evaluated the impact of the mutant tRNACGA Ser on fitness, tRNA stability, translation efficiency and aminoacylation kinetics. Our data demonstrate that these mutants are expressed and misincorporate Ser at CUGs, but their expression is repressed through an unknown molecular mechanism. We further demonstrate, using in vivo forced evolution methodologies, that the tRNACAG Ser can be easily inactivated through natural mutations that prevent its recognition by the seryl-tRNA synthetase. The overall data show that repression of expression of the mistranslating tRNACAG Ser played a critical role on the evolution of CUG reassignment from Leu to Ser. In order to better understand the evolution of natural genetic code alterations, we have also engineered partial reassignment of various codons in yeast. The data confirmed that genetic code ambiguity affects fitness, induces protein aggregation, interferes with the cell cycle and results in nuclear and morphologic alterations, genome instability and gene expression deregulation. Interestingly, it also generates phenotypic variability and phenotypes that confer growth advantages in certain environmental conditions. This study provides strong evidence for direct and critical roles of the environment on the evolution of genetic code alterations.

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The genetic code is not universal. Alterations to its standard form have been discovered in both prokaryotes and eukaryotes and demolished the dogma of an immutable code. For instance, several Candida species translate the standard leucine CUG codon as serine. In the case of the human pathogen Candida albicans, a serine tRNA (tRNACAGSer) incorporates in vivo 97% of serine and 3% of leucine in proteins at CUG sites. Such ambiguity is flexible and the level of leucine incorporation increases significantly in response to environmental stress. To elucidate the function of such ambiguity and clarify whether the identity of the CUG codon could be reverted from serine back to leucine, we have developed a forced evolution strategy to increase leucine incorporation at CUGs and a fluorescent reporter system to monitor such incorporation in vivo. Leucine misincorporation increased from 3% up to nearly 100%, reverting CUG identity from serine back to leucine. Growth assays showed that increasing leucine incorporation produced impressive arrays of phenotypes of high adaptive potential. In particular, strains with high levels of leucine misincorporation exhibited novel phenotypes and high level of tolerance to antifungals. Whole genome re-sequencing revealed that increasing levels of leucine incorporation were associated with accumulation of single nucleotide polymorphisms (SNPs) and loss of heterozygozity (LOH) in the higher misincorporating strains. SNPs accumulated preferentially in genes involved in cell adhesion, filamentous growth and biofilm formation, indicating that C. albicans uses its natural CUG ambiguity to increase genetic diversity in pathogenesis and drug resistance related processes. The overall data provided evidence for unantecipated flexibility of the C. albicans genetic code and highlighted new roles of codon ambiguity on the evolution of genetic and phenotypic diversity.

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Although the genetic code is generally viewed as immutable, alterations to its standard form occur in the three domains of life. A remarkable alteration to the standard genetic code occurs in many fungi of the Saccharomycotina CTG clade where the Leucine CUG codon has been reassigned to Serine by a novel transfer RNA (Ser-tRNACAG). The host laboratory made a major breakthrough by reversing this atypical genetic code alteration in the human pathogen Candida albicans using a combination of tRNA engineering, gene recombination and forced evolution. These results raised the hypothesis that synthetic codon ambiguities combined with experimental evolution may release codons from their frozen state. In this thesis we tested this hypothesis using S. cerevisiae as a model system. We generated ambiguity at specific codons in a two-step approach, involving deletion of tRNA genes followed by expression of non-cognate tRNAs that are able to compensate the deleted tRNA. Driven by the notion that rare codons are more susceptible to reassignment than those that are frequently used, we used two deletion strains where there is no cognate tRNA to decode the rare CUC-Leu codon and AGG-Arg codon. We exploited the vulnerability of the latter by engineering mutant tRNAs that misincorporate Ser at these sites. These recombinant strains were evolved over time using experimental evolution. Although there was a strong negative impact on the growth rate of strains expressing mutant tRNAs at high level, such expression at low level had little effect on cell fitness. We found that not only codon ambiguity, but also destabilization of the endogenous tRNA pool has a strong negative impact in growth rate. After evolution, strains expressing the mutant tRNA at high level recovered significantly in several growth parameters, showing that these strains adapt and exhibit higher tolerance to codon ambiguity. A fluorescent reporter system allowing the monitoring of Ser misincorporation showed that serine was indeed incorporated and possibly codon reassignment was achieved. Beside the overall negative consequences of codon ambiguity, we demonstrated that codons that tolerate the loss of their cognate tRNA can also tolerate high Ser misincorporation. This raises the hypothesis that these codons can be reassigned to standard and eventually to new amino acids for the production of proteins with novel properties, contributing to the field of synthetic biology and biotechnology.

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When the scribes of ancient Mesopotamia rewrote the Epic of Gilgamesh over a period of over two thousand years, the modifications made reflected the social transformations occurring during the same era. The dethroning of the goddess Inanna-Ishtar and the devaluation of other female characters in the evolving Epic of Gilgamesh coincided with the declining status of women in society. Since the 1960s, translations into modern languages have been readily available. The Mesopotamian myth has been reused in a wide variety of mythic and mythological texts by Quebecois, Canadian and American authors. Our analysis of the first group of mythic texts, written in the 1960s and 1970s, shows a reversal of the tendency of the Mesopotamian texts. Written at a time when the feminist movement was transforming North American society, these retellings feature a goddess with her high status restored and her ancient attributes re-established. Another group of writers, publishing in the 1980s and 1990s, makes a radical shift away from these feminist tendencies while still basically rewriting the Epic. In this group of mythic texts, the goddess and other female characters find their roles reduced while the male gods and characters have expanded and glorified roles. The third group of texts analysed does not rewrite the Epic. The Epic is reused here intertextually to give depth to mythological works set in the twentieth century or later. The dialogue created between the contemporary text and the Epic emphasises the role that the individual has in society. A large-scale comparative mythotextual study of texts that share a common hypotext can, especially when socio-historical factors are considered, provide a window onto the relationship between text and society. A comparative study of how the Epic of Gilgamesh is rewritten and referred to intertextually through time can help us relativize the understanding of our own time and culture.

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La Bibliothèque du Code civil de Charles-Chamilly de Lorimier et Charles-Albert Vilbon, parue au cours de la seconde moitié du XIXe siècle, demeure un des ouvrages de référence marquants de la production juridique québécoise. Les artisans de cet ouvrage présentent le droit civil comme un héritage du passé. L’oeuvre, par sa valorisation des anciens auteurs, propose une lecture du Code civil qui s’inscrit dans la tradition. En même temps, elle se révèle un outil adapté à la transformation que connaît alors la pratique du droit. La Bibliothèque constitue un témoin éloquent de l’évolution de la culture juridique québécoise.

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Tese de doutoramento, Bioquimica, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2015

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Wir beschreiben und belegen anhand eines Pilotprojekts in einer zweiten Grundschulklasse, dass Informatik in der Grundschule das Potential hat, fächerübergreifend Kompetenzen in fast allen Fächern des Grundschulkanons zu fördern. Wir erläutern mehrere Unterrichtseinheiten eines ScratchJr-Einsatzes und dokumentieren positive Wirkungen auf vielfältige Kompetenzen, die Kinder im Grundschulalter erwerben sollen. Der Beitrag stellt einen Erfahrungsbericht und qualitative Ergebnisse zur Verfügung. Eingesetzte Arbeitsmaterialien werden online zur Verfügung gestellt. Die bisherigen positiven Erfahrungen haben uns veranlasst, die Arbeit mit ScratchJr in der Pilotklasse auf mehrere Monate auszudehnen.

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The Nursing and Midwifery Council, the United Kingdom regulator of nursing and midwifery has recently revised its professional code of practice. This paper begins by arguing that a professional code must be capable of sustaining close reading and of action guidance. Using four exemplar clauses it is argued that the new revised code does not met this purpose. First, I show that in setting out requirements for consent and documentation, the meaning of the relevant clause has changed significantly during the editing process so that a literal reading of the final document bears little relation to established professional practice. Second, I argue that the clause concerning the nature of professional relationships has also been altered during the editing process so that it is inconsistent with other professional groups and established accounts of the professional nurse-patient relationship. Third, I argue that the clause concerning disclosure of confidential information, which survived revision and editing with its meaning intact is nevertheless factually incorrect and inconsistent with UK law and authoritative guidance. Finally, fourth, I argue that use of the word ‘inappropriate’ is inappropriate as it amounts to meaningless circularity, discussed in relation to a clause on expressing personal beliefs. Taken together, these examples demonstrate that the Code is seriously flawed and does not fulfil its purpose. One way that simple prescriptive clauses in the Code can be usefully understood is through the provision of detailed guidance. I argue that the NMC has changed its position on its view of the value of guidance and has significantly reduced the amount of written guidance and advice is provides. The paper concludes by arguing that in order to meet its action directing function, further clarifying revision and the provision of detailed guidance is required.

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The Grid Execution Management for Legacy Code Architecture (GEMLCA) enables exposing legacy applications as Grid services without re-engineering the code, or even requiring access to the source files. The integration of current GT3 and GT4 based GEMLCA implementations with the P-GRADE Grid portal allows the creation, execution and visualisation of complex Grid workflows composed of legacy and nonlegacy components. However, the deployment of legacy codes and mapping their execution to Grid resources is currently done manually. This paper outlines how GEMLCA can be extended with automatic service deployment, brokering, and information system support. A conceptual architecture for an Automatic Deployment Service (ADS) and for an x-Service Interoperability Layer (XSILA) are introduced explaining how these mechanisms support desired features in future releases of GEMLCA.

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Orientador: Mestre Alberto Couto

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A CIF é uma ferramenta universal desenvolvida pela OMS que permite a classificação de funcionalidade e incapacidade, através de uma visualização global do que condiciona o desempenho do indivíduo na concretização de atividades e na participação em ocupações. A ideologia da CIF e os seus componentes interrelacionam-se com a essência da TO, indo ao encontro dos modelos da profissão. As UCCI constituem uma atualidade em Portugal e o terapeuta ocupacional é um dos profissionais obrigatórios na equipa multidisciplinar destas unidades. Atendendo à relevância internacional da CIF, à sua ligação com a TO e à necessidade de tornar a CIF operacional na prática clínica diária dado que é uma ferramenta complexa e extensa, é objetivo deste estudo contribuir para a construção de um code set da CIF para terapeutas ocupacionais que exercem funções em UCCI, especificamente em UC, UMDR e ULDM. Para a concretização desta investigação, utilizou-se a técnica de Delphi, que envolveu duas rondas. Na primeira ronda foi possível contar com a participação de 37 terapeutas ocupacionais experientes na área, uma vez que exercem funções em UCCI, e na segunda ronda contou-se com a participação de 20 elementos. Obtiveram consenso na última ronda de Delphi um total de 96 categorias, constituindo esta listagem uma proposta de code set para UCCI. No que se refere às tipologias de unidades, 69 categorias obtiveram consenso em UC, 91 em UMDR e 41 em ULDM. Concluiu-se que a criação de code sets poderá constituir uma mais-valia em contexto de equipa multidisciplinar das UCCI, sendo uma forma de tornar a CIF operacional na prática clínica diária.

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In this study, efforts were made in order to put forward an integrated recycling approach for the thermoset based glass fibre reinforced polymer (GPRP) rejects derived from the pultrusion manufacturing industry. Both the recycling process and the development of a new cost-effective end-use application for the recyclates were considered. For this purpose, i) among the several available recycling techniques for thermoset based composite materials, the most suitable one for the envisaged application was selected (mechanical recycling); and ii) an experimental work was carried out in order to assess the added-value of the obtained recyclates as aggregates and reinforcement replacements into concrete-polymer composite materials. Potential recycling solution was assessed by mechanical behaviour of resultant GFRP waste modified concrete-polymer composites with regard to unmodified materials. In the mix design process of the new GFRP waste based composite material, the recyclate content and size grade, and the effect of the incorporation of an adhesion promoter were considered as material factors and systematically tested between reasonable ranges. The optimization process of the modified formulations was supported by the Fuzzy Boolean Nets methodology, which allowed finding the best balance between material parameters that maximizes both flexural and compressive strengths of final composite. Comparing to related end-use applications of GFRP wastes in cementitious based concrete materials, the proposed solution overcome some of the problems found, namely the possible incompatibilities arisen from alkalis-silica reaction and the decrease in the mechanical properties due to high water-cement ratio required to achieve the desirable workability. Obtained results were very promising towards a global cost-effective waste management solution for GFRP industrial wastes and end-of-life products that will lead to a more sustainable composite materials industry.

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Compreender a funcionalidade de uma criança é um desafio persistente em contextos de saúde e educação. Na tentativa de superar esse desafio, em 2007, a Organização Mundial de Saúde desenvolveu a Classificação Internacional de Funcionalidade, Incapacidade e Saúde para Crianças e Jovens (CIF-CJ) como o primeiro sistema de classificação universal para documentar a saúde e funcionalidade da criança. Apesar de a CIF-CJ não ser um instrumento de avaliação e intervenção, tem, no entanto, a capacidade de servir de enquadramento para o desenvolvimento de ferramentas adaptadas às necessidades dos seus utilizadores. Considerando que no contexto escolar, a escrita manual encontra-se entre as atividades mais requeridas para a participação plena de uma criança, parece ser pertinente a definição de um conjunto de códigos destinados a caracterizar o perfil de funcionalidade de uma criança, no que se refere à escrita manual. O objetivo deste estudo foi, pois, o desenvolvimento de um conjunto preliminar de códigos baseado na CIF-CJ que possa vir a constituir um code set para a escrita manual. Dada a complexidade do tema e atendendo a que se pretende alcançar consenso entre os especialistas sobre quais as categorias da CIF-CJ que devem ser consideradas, optou-se pela utilização da técnica de Delphi. A escolha da metodologia seguiu a orientação dos procedimentos adotados pelo projeto Core Set CIF. De dezoito profissionais contactados, obtiveram-se respostas de sete terapeutas ocupacionais com experiência em pediatria, que participaram em todas as rondas. No total, três rondas de questionários foram realizadas para atingir um consenso, com um nível de concordância, previamente definido, de 70%. Deste estudo resultou um conjunto preliminar de códigos com 54 categorias da CIF-CJ (16 categorias de segundo nível, 14 categorias de terceiro nível e uma categoria de quarto nível), das quais 31 são categorias das funções do corpo, uma categoria das estruturas do corpo, 12 categorias de atividades e participação e 10 categorias de fatores ambientais. Este estudo é um primeiro passo para o desenvolvimento de um code set para a escrita manual baseado na CIF-CJ , sendo claramente necessário a realização de mais pesquisas no contexto do desenvolvimento e da validação deste code set.