Chemical and physical pretreatments of microalgal biomass

Non-axenic microalga Chlorella sorokiniana was cultivated in batch cultures, and its total sugar composition was determined. The microalga under study showed a total sugar concentration of 21.44 ± 0.46% (w/w). The effects of freeze-drying, oven-drying, freezing and thawing, chemical and the combination of hydrothermal and chemical pretreatments were evaluated. In the combined pretreatment different concentrations of H2SO4 and reaction times were also optimized. It was possible to determine that the sugar extraction yields more significant were 59.5% for the lyophilization, 6.2% with 6 cycles of freeze and thawing and around 100% for 2 and 4% (v/v) of H2SO4 at 121 °C for 30 min. Some of the methods that were described in this study are interesting to facilitate cost-efficient conversion of microalgal biomass into biofuels.info:eu-repo/semantics/publishedVersio

As expressões artísticas na valorização dos costumes e tradições açorianas : uma reflexão no âmbito do Estágio Pedagógico na Educação Pré-Escolar e no 1º Ciclo do Ensino Básico

Mestrado (Relatório de Estágio), Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico, 17 de setembro de 2019, Universidade dos Açores.O presente Relatório de Estágio, realizado no âmbito do Mestrado em Educação Pré-Escolar e Ensino do 1.º Ciclo do Ensino Básico, tem como temática As Expressões Artísticas na valorização dos costumes e tradições açorianas: uma reflexão no âmbito do Estágio Pedagógico em Educação Pré-Escolar e Ensino do Primeiro Ciclo do Ensino Básico, e como finalidade relatar e aprofundar o que foi vivenciado pela estagiária, no contexto dos seus estágios pedagógicos, assumindo uma atitude reflexiva e construtiva sobre o papel que estes tiveram na sua aprendizagem profissional. Para além de funcionar como um espaço de reflexão sobre a ação educativa que desenvolvemos, este trabalho visa um aprofundamento, devidamente fundamentado, da área curricular das Expressões, mais propriamente, no que respeita ao seu papel como veículos de transmissão da nossa cultura e das nossas tradições. Conscientes do papel e do lugar que estas áreas têm vindo a ocupar no currículo, nacional e regional, nem sempre exploradas e valorizadas pelos profissionais do ensino, entendemos ser essencial uma reflexão mais aprofundada sobre esta matéria, até pelas suas naturais relações com o tema que decidimos aprofundar no presente Relatório. Para além disso, não sendo este um tema muito debatido em trabalhos desta natureza, carece de uma pesquisa da nossa parte no que toca às potencialidades e cumplicidades pedagógicas das conexões que se podem explorar a partir dele. Apresentaremos ainda os resultados de um estudo empírico que realizámos, que convocou as opiniões e representações de Educadores de Infância e Professores do 1.º Ciclo do Ensino Básico, acerca das conexões em causa, na tentativa de compreendermos de que forma é que a exploração das Expressões pode contribuir para um maior e melhor conhecimento e valorização dos costumes e tradições açorianas por parte das gerações vindouras. Foram entrevistadas, no total, 10 docentes (5 Educadoras de Infância e 5 Professoras do 1.º Ciclo do Ensino Básico), de diversas ilhas do arquipélago e em diferentes fases da sua carreira profissional, que nos deram conta de atividades por elas desenvolvidas neste contexto, bem como das suas potencialidades educativas, que entenderam ser muito benéficas, quer no contexto da sua ação educativa diária, quer pelas competências que promovem nas crianças que lhes são confiadas.ABSTRACT: This report, elaborated under the guidelines of the Masters Degree in Pre-school and Elementary Education, supports the theme The Artistic Expressions in the valuation of the Azorean traditions and lifestyle: a reflection under the scope of the Internship in Pre-school and Elementary Education, and has a goal to report and analyze what was experienced by the intern, within the educational guidelines, interpreting and reflecting upon the impact of these in her professional development. Even though this study works as a reflection on how education is part of our development, it also brings a focus point to the curricular area of Expressions as a vehicle to the streaming of our traditions and customs. Aware of how important these areas are in the national and regional curriculum - not always explored and valued correctly - we have concluded that it was necessary to have a more broadening and deepening exploration of the subject in question. Considering that this is not a popular topic amongst these reports we found that it required the attention it deserved in the present report. In this report you can also find a study conducted amongst some Pre-School and Elementary school teachers, focusing on how the Expressions topic can be of value for a better understanding and valuation of the Azorean customs and traditions and the streaming to future generations. In the study, we interviewed 10 educators (5 pre-school teachers and 5 Elementary school teachers) from different islands of the archipelago and in different stages of their careers, that provided us with their experiences about this topic as well as valuing its spot in the children's development and its educational potential

Are the determinants of young SMEs profitability different?: empirical evidence using dynamic estimators

Based in two sub-samples of Portuguese SMEs: 1) 495 young SMEs; and 2) 1350 old SMEs, we conclude that age is a determinant factor in the relationships formed between determinants and profitability. Age, size, liquidity and long-term debt are of greater relative importance for the increased profitability of young SMEs, while risk is of greater relative importance for the diminished profitability of this type of SME, compared to the case of old SMEs. R&D expenditure is of greater relative importance for increased profitability in old SMEs, this type of SME having more persistent profitability, compared to the case of young SMEs

O papel da trimetilação da histona H3 na transcrição

Tese de mestrado. Biologia (Biologia Molecular e Genética). Universidade de Lisboa, Faculdade de Ciências, 2011Os nucleossomas, unidades básicas da cromatina, formados por um octâmero de histonas em associação com um fragmento de DNA, possuem um papel de extrema importância na regulação de processos biológicos que requerem o acesso ao DNA. Estas estruturas controlam eventos chave durante processos tão distintos como a transcrição, replicação e reparação do DNA. As histonas constituintes dos nucleossomas podem sofrer modificações pós-traducionais, entre as quais se salienta neste estudo a trimetilação da lisina 36 da histona H3 (H3K36me3). Esta modificação está presente nas regiões intragénicas de genes activamente transcritos, sendo a sua presença mais significativa na extremidade 3’ e também nos exões relativamente aos intrões. Tais propriedades demonstram uma relação entre a H3K36me3 e a transcrição, embora o seu papel ainda não seja claro. Neste estudo utilizaram-se metodologias bioquímicas tais como imunoprecipitação da cromatina, western blot e digestão com nucleases para investigar qual o papel exacto desta marca na transcrição em células humanas. Os resultados demonstraram que células com níveis diminuídos de H3K36me3 têm iniciação de transcrição em regiões intragénicas distintas do promotor, o que sugere uma alteração da conformação da cromatina que permite uma maior acessibilidade ao DNA. De facto, experiências adicionais mostraram que perante uma depleção de H3K36me3 a densidade de nucleossomas presentes ao longo dos genes diminui. Por último, verificou-se que a presença desta modificação na histona H3 é necessária para o recrutamento da Spt16, uma proteína envolvida na remontagem dos nucleossomas após a passagem da RNA Polimerase II (RNAPII) na transcrição. Em conjunto, os resultados permitem desenhar um modelo em que a H3K36me3 exerce uma função determinante na manutenção da cromatina numa conformação capaz de suprimir a iniciação da transcrição em regiões intragénicas. Esta função envolve o recrutamento da Spt16 que promove a remontagem dos dímeros H2A-H2B que haviam sido perdidos durante a passagem da RNAPII.Nucleosomes are the basic units of chromatin and consist of a histone octamer in association with a DNA segment. Nucleosomes have an important role in regulating biological processes that require DNA access. These structures influence key events during transcription, replication and DNA repair. Histones present in nucleosomes can have a number of different post-translational modifications. Herein we focus on a specific histone methylation: trimethylation of lysine 36 of histone H3 (H3K36me3). This histone modification is present on intragenic regions of active genes and its levels rise towards the 3’ end of active genes. This modification is also more abundant over exons relative to introns. These properties disclose a link between H3K36me3 and transcription, although the precise role of this mark is not yet understood. Using a biochemical approach, which includes techniques such as chromatin immunoprecipitation, western blot and nuclease digestion assays I aimed at evaluating the role of H3K36me3 during transcription in human cells. The results of these experiments revealed that decreased H3K36me3 levels correlate with increased transcription initiation on intragenic regions. Additional data suggested that this histone mark impacts on chromatin structure promoting a more compact and less accessible conformation. In support of this hypothesis, nuclease digestion assays revealed a decreased density of nucleosomes along the genes in the absence of H3K36me3. Finally, we verified that the presence of this histone mark shepherds Spt16 recruitment to the transcriptional units after RNAPII passage. Spt16 then promotes the deposition of histone H2A-H2B dimmers onto the DNA to reassemble a complete nucleosome and maintain the chromatin integrity. Together, these data allow us to envisage a model in which H3K36me3 suppresses transcription initiation on intragenic regions by signaling the recruitment of Spt16 and the reassembly of histone H2A-H2B ejected during RNAPII elongation

The Green Energy Procurement Policy and its Consequences: A Green Light to make Business Turn Smarter

Este trabalho de investigação foi produzido com o apoio do CIGEST - Centro de Investigação em Gestão, dentro da linha de investigação de Ambiente e Sustentabilidade.Concepts such as Sustainable Development and Green Procurement are increasingly present today. Green Procurement has a great overall importance in reducing environmental impacts regarding consumer goods and services and, consequently, the way of living in society as well as the whole world, in a Sustainable Development perspective. The general framework of the study focuses on the United Nations and the European Union‘s Green Procurement policy that has consequences on the Portuguese Energy Policy and affects purchases and businesses. The main concepts to develop are the Sustainability, the Sustainable Development and the Green Procurement. Green Procurement must be, implemented in a holistic way organizations and be in consumers concerns, by including environmental and social considerations into its acquisition practices. Lacroix (2011) defines Green Procurement by the following way: Green procurement is the purchasing of products or services which have a lower impact on the environment over their whole life cycle than the standard equivalent. (P. 2) The main objective of the study is to identify the current policies of green procurement policies in the UN, EU and in Portugal and, consequently, in organizations, and to explore the issues that may affect the people‘s behavior and business and activity

Tax havens or tax hells? A discussion of the historical roots and present consequences of tax havens

Tax havens are not recent phenomena. However, in contrast to historical precedents, tax havens in the age of mobile capital allow for non-consensual transfers and are not profitable for every citizen. We discuss the four main groups of tax havens (former Western possessions, sovereign nations, countries controlled by cartels, and emerging economies). This article also synthesizes the history of tax havens and describes their current heterogeneity, discussing the main methods available to regulate tax haven flows. Some of the most efficient methods involve unilateral measures (such as the Fiscal Transparency of Outland Societies) but also encompass multilateral measures (such as Tax Harmonization and the Request for Information)

Corporate taxes and high-quality entrepreneurship

We examine the impact of corporate taxation on entrepreneurship, using a quasi-natural experiment, which substantially reduced the corporate tax rate for start-ups located in inland municipalities in Portugal. Using a difference-in-differences approach and IV regression, we find that the tax reform increased firm entry and new firm job creation. The entrepreneurs who took advantage of this tax reform are relatively older, and are better-educated individuals. Their start-ups are relatively larger, more productive, and are more likely to survive the first 3 years. These findings suggest that corporate taxation is an imperative constraint for entrepreneurship, particularly for high-quality entrepreneurs. These better-educated individuals find it easier to overcome the hurdles of tax legislation and to make use of the opportunities created by a specific tax reform.info:eu-repo/semantics/publishedVersio

SOME MATRIX MODELS

In this paper we present three matrix models that express the relevance of studying Linear Algebra, trying to answer the question Why study Linear Algebra?, often asked by students. Linear Algebra is fundamental within the mathematical modelling of phenomena, so we explore examples of models in which it is applied, in a simple manner as possible appropriated to the students’ knowledge. The models presented are Leontief Economic Model, Leslie Population Growth Model and Rating Web Pages Model

WHY CASTING OUT NINES?

In this paper our purpose is to answer questions like: Why casting out nines works? Why it fails? Why casting out nines and not, for example, ―casting out elevens‖? The casting out nines method was used to ―check‖ the results of operations on positive integers. Although not currently taught in elementary school it hides mathematical concepts that will help to understand important current applications such as internet security. We present the mathematical concepts behind the casting out nines method: some tests for computing remainders and the congruence relation modulo n and its properties