Expression profile of genes involved in hydrogen sulphide liberation by _Saccharomyces cerevisiae_ grown under different nitrogen concentrations

The present work aims to elucidate molecular mechanisms underlying hydrogen sulphide production in _S. cerevisiae_ associated to nitrogen deficiency. To assess, at a genome-wide level, how the yeast strain adapted to the progressive nitrogen depletion and to nitrogen re-feeding, gene expression profiles were evaluated during fermentation at different nitrogen concentrations, using the DNA array technology. The results showed that most MET genes displayed higher expression values at the beginning of both control and N-limiting fermentation, just before the time at which the release of sulphide was observed. MET genes were downregulated when yeast stopped growing which could associate MET gene expression levels with cell growth. The over expression of MET genes after nitrogen addition was confirmed by a new release of H2S during the new set of fermentation experiments. In addition, to confirm gene expression profiles observed from macroarray results, real time RT-PCR was performed on 6 genes using additional sets of biological replicates. These genes were selected based on the assumption that differences in sulphide production observed among strains are due to genetic variations of the expression of genes involved in the Sulphate Reduction Pathway. An integration of expression data of genes involved in sulphur assimilation and sulphur amino acid biosynthesis with hydrogen sulphide production is presented

The imported english textbook and the teaching of writing

O texto analisa como a série Interchange, terceira edição, conceitua escrita e seu ensino e se a abordagem de ensino dessa habilidade muda ao longo da série. Os exercícios do livro foram classificados em cinco categorias e concluiu-se que a escrita, de modo geral, foi concebida como demonstração de conhecimento gramatical e de vocabulário, como uma prática mecânica de uso da língua descontextualizada, padronizada e prescindível de modelos ou amostras. O ensino da escrita assumido pelo material adota uma abordagem inferior à tradicional e o material procura uma atualização teórica e mercadológica com a inserção de técnicas da abordagem processual e com a etiquetagem de textos com termos referentes aos gêneros textuais.The paper analyses how the textbook series Interchange, third edition, conceptualizes writing, writing instruction and if the latter changes as the series moves along. The exercises of the book were classified into five categories and it was possible to conclude that overall writing was conceived as a mere opportunity for grammar and vocabulary practice, as a mechanical decontextualized practice of language, not based on models or samples. The writing instruction adopts a worse procedure than the traditional perspective and the material seeks theoretical and market update through the insertion of process writing techniques and through labeling texts with genre names

Polyflow: a Polystore-compliant mechanism to provide interoperability to heterogeneous provenance graphs

Many scientific experiments are modeled as workflows. Workflows usually output massive amounts of data. To guarantee the reproducibility of workflows, they are usually orchestrated by Workflow Management Systems (WfMS), that capture provenance data. Provenance represents the lineage of a data fragment throughout its transformations by activities in a workflow. Provenance traces are usually represented as graphs. These graphs allows scientists to analyze and evaluate results produced by a workflow. However, each WfMS has a proprietary format for provenance and do it in different granularity levels. Therefore, in more complex scenarios in which the scientist needs to interpret provenance graphs generated by multiple WfMSs and workflows, a challenge arises. To first understand the research landscape, we conduct a Systematic Literature Mapping, assessing existing solutions under several different lenses. With a clearer understanding of the state of the art, we propose a tool called Polyflow, which is based on the concept of Polystore systems, integrating several databases of heterogeneous origin by adopting a global ProvONE schema. Polyflow allows scientists to query multiple provenance graphs in an integrated way. Polyflow was evaluated by experts using provenance data collected from real experiments that generate phylogenetic trees through workflows. The experiment results suggest that Polyflow is a viable solution for interoperating heterogeneous provenance data generated by different WfMSs, from both a usability and performance standpoint.Muitos experimentos científicos são modelados como workflows (fluxos de trabalho). Workflows produzem comumente um grande volume de dados. De forma a garantir a reprodutibilidade desses workflows, estes geralmente são orquestrados por Sistemas de Gerência de Workflows (SGWfs), garantindo que dados de proveniência sejam capturados. Dados de proveniência representam o histórico de derivação de um dado ao longo da execução do workflow. Assim, o histórico de derivação dos dados pode ser representado por meio de um grafo de proveniência. Este grafo possibilita aos cientistas analisarem e avaliarem resultados produzidos por um workflow. Todavia, cada SGWf tem seu formato proprietário de representação para dados de proveniência, e os armazenam em diferentes granularidades. Consequentemente, em cenários mais complexos em que um cientista precisa analisar de forma integrada grafos de proveniência gerados por múltiplos workflows, isso se torna desafiador. Primeiramente, para entender o campo de pesquisa, realizamos um Mapeamento Sistemático da Literatura, avaliando soluções existentes sob diferentes lentes. Com uma compreensão mais clara do atual estado da arte, propomos uma ferramenta chamada Polyflow, inspirada em conceitos de sistemas Polystore, possibilitando a integração de várias bases de dados heterogêneas por meio de uma interface de consulta única que utiliza o ProvONE como schema global. Polyflow permite que cientistas submetam consultas em múltiplos grafos de proveniência de maneira integrada. Polyflow foi avaliado em conjunto com especialistas usando dados de proveniência coletados de workflows reais que apoiam o estudo de geração de árvores filogenéticas. O resultado da avaliação mostrou a viabilidade do Polyflow para interoperar semanticamente dados de proveniência gerado por distintos SGWfs, tanto do ponto de vista de desempenho quanto de usabilidade

Eco-energy Smart Card”: A human-interactive all paper based, mechanical energy harvester

Nowadays, it is imperative that modern society finds sustainable ways to harvest energy. This means society is forced to look to new ways to generate and store energy, while reducing, simultaneously, the stress on raw materials demand and the amount of waste generated. Our research tackles these two points by making close to zero e-waste clean energy harvesting devices. The core idea behind it is based on the mechano-responsive charge-transfer mechanism and energy-transfer process in π-conjugated polymer at the organic-metal interface layer. A localized forced deformation of the interface has been applied against the polymer surface, allowing charge transfer between material interfaces. The experimental results demonstrated that during contacting force, the conjugated polymer film shows electrical output through the charge transfer mechanism within metal/polymer interfaces. Flexible and low-cost energy harvesting devices built have an active layer constituted by a PANi/cellulose composite which was tapped together to a charge collector layer, that was made from a paper based metallic electrode. These devices have a total maximum power density and maximum current density of 1.75 Wm-2 and 33.5 mA m-2 , respectively. Towards the practical applicability, these devices are able to light up to 40 blue LEDs as well as a commercial humidity sensor

Gazelle Entrepreneurs

Mestrado em FinançasAs empresas gazela são empresas jovens de alto crescimento. Estas têm menos de cinco anos de idade, empregam mais de dez trabalhadores e o seu crescimento anualizado é maior do que vinte por cento por ano, durante um período de três anos. Dada a importância destas empresas na economia, alguns estudos anteriores avaliaram os principais determinantes para crescimento destas empresas a curto prazo. Este estudo tem uma abordagem nova e avalia o desempenho a longo prazo das gazelas, em termos de criação de emprego e sobrevivência. Mais especificamente, analisamos se as empresas gazela continuam a superar as outras start-ups em fase de arranque, a longo prazo ou se o seu crescimento é temporário. Para proporcionar uma nova visão, foi utilizado uma base de dados empregador-empregado (QP- "Quadros de Pessoal"). Os nossos dados permitem identificar as empresas gazela e seus fundadores. Nós selecionamos todas as start-ups estabelecidas entre 2000 e 2005 e seguimo-las por um período de sete anos. Identificamos 175 empresas gazela e 37.700 empresas não-gazela. Os nossos resultados sugerem que as empresas gazelas têm um melhor desempenho a longo prazo. O tamanho das empresas gazela aumentou em 144, 130, 86, 69, 52, 37 e 19 porcento entre os anos 4 e 10, respetivamente, em comparação com as empresas não-gazela. No entanto, não há evidência estatística que permita concluir que as empresas gazela têm uma maior taxa de sobrevivência no longo prazo.Gazelle firms are young high growth ventures. They have less than five years old, employ more than ten workers and their annualized growth is greater than twenty percent per year over a three-year period. Given their importance in the economy, previous studies have evaluated the main determinants for their short-term growth. This study takes a novel approach and evaluates gazelles? long-term performance, in terms of job creation and survival. More specifically, we analyze if gazelle firms continue to outperform the other start-ups in the long run or if their growth is temporary. To provide new insights, we used a matched employer-employee dataset (QP- ?Quadros de Pessoal?). Our data enable us to identify gazelle start-ups and their founders. We select all start-ups established between 2000 and 2005 and we track them for a seven-year period. We identify 175 gazelle start-ups and 37,700 non-gazelle start-ups. Our results suggest that gazelle firms perform better on the long run. In comparison with the non-gazelle start-ups, their size increased by 144, 130, 86, 69, 52, 37 and 19 percent in years 4 to 10, respectively. However, we have not found statistical evidence of gazelle firms being more likely to survive on the long run, thus we cannot conclude that gazelle firms are less likely to survive on the long run

Massive MIMO transmission techniques

Next generation of mobile communication systems must support astounding data traffic increases, higher data rates and lower latency, among other requirements. These requirements should be met while assuring energy efficiency for mobile devices and base stations. Several technologies are being proposed for 5G, but a consensus begins to emerge. Most likely, the future core 5G technologies will include massive MIMO (Multiple Input Multiple Output) and beamforming schemes operating in the millimeter wave spectrum. As soon as the millimeter wave propagation difficulties are overcome, the full potential of massive MIMO structures can be tapped. The present work proposes a new transmission system with bi-dimensional antenna arrays working at millimeter wave frequencies, where the multiple antenna configurations can be used to obtain very high gain and directive transmission in point to point communications. A combination of beamforming with a constellation shaping scheme is proposed, that enables good user isolation and protection against eavesdropping, while simultaneously assuring power efficient amplification of multi-level constellations

The internationalization of higher education in Brazil and its linguistic demands: a petition for English (additional languages) learning institutionalization

The present essay aims to reflect on the internationalization of Higher Education which is the background of the articles published in this special issue Academic literacy in English: pedagogical practices in times of internationalization.  This discussion will explore the linguistic (English) demands imposed by the internationalization of Higher Education and advocate for the institutionalization of English/additional languages learning and teaching support by the universities. The thesis defended in this piece is that without proper provision and learning of these languages for academic purposes by the universities, internationalization initiatives will be ineffective