Effects of fiscal policy: measurement issues and structural change

Doutoramento em EconomiaConsiderable uncertainty surrounds the macroeconomic effects of fiscal policy. The re-search presented in this dissertation firstly aims at improving on the methods used to measure such effects - which feature vector autoregressions (VARs) as the basic tool. The investigation is partly carried out using structural VARs. The methodological innova¬tions in that part concern the joint identification of fiscal shocks vis-a-vis monetary policy shocks and the estimation of a model with time-varying parameters using a non-recursive identification scheme. I also use reduced-form VARs to assess the effects of a novel shock measure, derived from budget forecasts, that is arguably free of anticipatory movements. The second aim of the dissertation is to present empirical results for the US, focusing on the way the impacts of the government budget on the economy have changed over time. The thesis is divided into three essays. In the first one, I present evidence that taxes and transfers were the most important force attenuating the severity of recessions up to the eighties, surpassing the role of monetary policy. Fiscal policy has, however, become less effective in stimulating output in the course of the last decades. The findings in the second and the third essays corroborate this conclusion. Such a change in effectiveness is particularly marked for the shock measure that is relatively unaffected by anticipation, which features multipliers with non-conventional signs in the recent period. In general, these findings call for more research on the factors that intervene in the transmission mechanism of fiscal policy and can bring about important variation in its impacts

Implicações das atividades de enriquecimento curricular (AEC) na organização do trabalho docente e nas práticas de monodocência - representações dos atores organizacionais

Dissertação apresentada à Escola Superior de Educação de Lisboa para obtenção de grau de mestre em Administração EscolarNo âmbito da Escola a Tempo Inteiro (ETI), a introdução das Atividades de Enriquecimento Curricular (AEC) veio alterar a organização das escolas do 1.º Ciclo do Ensino Básico (1.º CEB) de uma forma muito significativa, com repercussões na estrutura, nos processos, nos modos de organização do trabalho dos professores, nas relações e interações e nos tempos e dos espaços escolares de educação formal e não formal. Com o presente estudo no âmbito da administração educacional, pretende-se dar a conhecer, a partir das representações dos atores organizacionais, as influências e implicações do programa de generalização das AEC, nas lógicas organizacionais das escolas públicas ao nível do conceito e das práticas de monodocência no 1.º ciclo do ensino básico. Realizado em três Agrupamentos de Escolas da zona de Lisboa, o estudo visou: conhecer e analisar as representações dos gestores de topo e intermédios sobre o modelo de implementação da política de ETI e as suas implicações nas dimensões organizacionais dos agrupamentos de escolas; e analisar as implicações das AEC no regime de monodocência, ao nível da organização do trabalho dos professores do 1.º ciclo do ensino básico, dos processos de articulação entre docentes e nos processos de transição para o 2.º ciclo do ensino básico. As conclusões apontam para a existência de divergências entre as representações dos Diretores e as dos Coordenadores do 1.º ciclo em relação ao modelo de implementação da política; e para a importância do trabalho de parceria e articulação que é realizado entre os professores das AEC e os do 1.º ciclo, reconhecendo-se: a emergência de uma “monodocência coadjuvada”; a existência de relações profissionais de cooperação e articulação; e a existência de mais-valias para as escolas trazidas pelos professores das AEC, por serem portadores de outras valências de conhecimento e contribuírem para facilitar a transição entre ciclos.ABSTRACT In the scope of full-time school (FTS), the introduction of extra academic activities (EAA), has come to alter the organization of elementary schools in a manner of most significance, with repercussions in the structure, procedures, in the ways of management of the educators’ work, in the relations and interactions and the school times and spaces of formal and non-formal education. With the following study in the scope of educational administration, it aims to make known, from the representations of the organizational players, the influences and implications of EAA’s generalization program, in the organizational logics of public schools at the concept level and the single educator practices in the elementary school. Accomplished in three school groupings in the Lisbon area, the study aimed: To acknowledge and analyze the representations of top and medium managers over the model of FTS’ political implementation and its implications on the schools’ groupings organizational dimensions; and analyze the EAA’s implication on the single educators’ regime, on the level of organization of the elementary school’s lecturers’ work, of the articulation processes between lecturers and the transitional processes to the middle school level. The conclusions point to the existence of divergences between the representations of the Principals and the Coordinators of the elementary school in relation to the model of political implementation; and to the importance of a partnership’s work and articulation which is accomplished between the EAA’s lecturers and those from the elementary school, acknowledging that: the appearance of a “single lecturer’s cooperation”; the existence of professional relations of cooperation and articulation; and the existence of gains to the schools brought by the EAA’s lecturers, for being carriers of other knowledge advantages and for contributing to facilitate the transition between cycles.N/

Detection of microscopic traces of explosive residues on textile fabrics by Raman spectroscopy

Direct or cross‐contamination of explosive residues on clothing is of high occurrence when handling explosive materials, leading to physically trapped particles between the fibres. In this work, the detection and identification of trace amounts of organic explosives, inorganic explosives, and oxidizing salts trapped between the fibres of dyed and undyed synthetic and natural textile clothing fabrics were studied using two (desktop and portable) confocal Raman microscopes. The results show that, despite the contribution of the textile fabric in terms of fluorescence and vibrational bands coming from the fibres and dyes, detection and identification of the explosive/oxidizing salt particles trapped on highly interfering surfaces was possible. Limits of detection were estimated in the nanogram/picogram range depending on the explosive and fabric. However, problems involving the burning of either some explosive particles or dark cloth textiles were verified, which can cause a destruction of the sample. Also, the analysis of improvised homemade explosives (potassium nitrate mixed with 10 different fuel substances) was studied to evaluate possible interferences

Estudo das variáveis preditivas da indisciplina escolar percecionada por alunos

O objetivo geral, explorar as relações existentes entre determinantes de contexto sociodemográfico, religioso, sociofamiliar, psicossocial e de clima escolar e a indisciplina escolar percepcionada pelos alunos. Recorrendo a um estudo de natureza quantitativa, do tipo transversal com características descritivo-correlacionais, inquirimos 772 alunos adolescentes portugueses

Capability of Copper Hydroxy Nitrate (Cu2(OH)3NO3) as an Additive to Develop Antibacterial Polymer Contact Surfaces: Potential for Food Packaging Applications

The globalization of the market, as well as the increasing world population, which require a higher demand for food products, pose a great challenge to ensure food safety and prevent food loss and waste. In this sense, active materials with antibacterial properties are an important alternative in the prolongation of shelf life and ensuring food safety. In this work, the ability of copper(II) hydroxy nitrate (CuHS) to obtain antibacterial films based on low density polyethylene (LDPE) and polylactic acid (PLA), was evaluated. The thermal properties of the composites, evaluated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), showed that the concentrations of added CuHS do not particularly change these characteristics with respect to the neat polymer matrix films. The mechanical properties, determined using dynamic mechanical analysis (DMTA), indicate a small increase in the brittleness of the material in PLA-based composites. The antibacterial properties against Listeria monocytogenes and Salmonella enterica were evaluated using a surface contact test, and a bacterial reduction of at least 8 to 9 logarithmic units for the composites with 0.3% CuHS, both in LDPE and PLA and against both bacteria, were achieved. The reusability of the composite films after their first use demonstrated a higher stability against Listeria monocytogenes. The migration and cytotoxicity of the composites loaded with 0.3% CuHS was evaluated, demonstrating the safety of these materials, which reinforces their potential use in food packaging applications.Ministerio de Ciencia e InnovaciónUniversidad de AlcaláEuropean Commissio

Construção e validação da escala indisciplina escolar percecionada por alunos (EIEPA)

Escala Indisciplina Escolar Percecionada por Alunos (EIEPA). O Projeto de pesquisa é transversal, a pesquisa não-experimental, com características descritivas, estudos de correlação e com técnicas explicativas. Os resultados são muito significativos e é possível constatar que o índice alpha de Cronbach (0,960) apresenta muito boa consistência interna. O valor encontrado para o coeficiente de Spearman-Brown (0,911) e este revela-se bastante bom e no que diz respeito ao coeficiente de correlação de Split-half, (0,939) que revela ser igualmente revelador de uma boa consistência interna. A Escala revelou-se multifatorial e foram encontrados quatro factores

A sustentabilidade da política orçamental em Portugal : uma abordagem econométrica

Mestrado em Matemática Aplicada à Economia e à GestãoNos últimos anos, têm surgido diversos estudos com o objectivo de determinor a consistência da trajectória das receitas, despesas e dívida pública com a restrição orçamental intertemporal do governo, como condição de sustentabilidade da política orçamental. Neste texto são apresentados os principais resultados teóricos que têm sido obtidos neste campo e é feita a sua aplicação a Portugal. Conclui-se que no período em análise, 1947-93, e também para um período mais curto com início em 1970, a política orçamental foi compatível com a restrição intertemporal. Verifica-se ainda que a relação de equilíbrio entre receitas e despesas estimada, implicaria a divergência do rácio da è dívida pública em relação ao produto. Contudo, foi detectada instabilidade nas estimativas do vector de cointegração entre receitas e despesas e, em particular, uma alteração de estrutura a partir de meados da década de oitenta. Deste modo, com base na estrutura estimada considerando todo o período amostrai, não é possível concluir que o rácio da dívida esteja divergir.In recent years, several studies have attempted to assess the consistency of the time palh of govemment expenditures, revenues and debt with the assumption of intertemporal budget balance, as a condition for the sustainability of fiscal policy. This text presents the main theoretical results in this field and its application to Portugal. It was found that the intertemporal budget constraint has been satisfied over the whole sample period, 1947-93, and also over a shorter period, started in 1970. Moreover,. the estimated long-run relationship between revenue and expenditure would imply a diverging debt-GDP ratio. However, has been detected parameter instability in the cointegration relationship between revenue and expenditure and, particularly, the evidence suggests that, after the mid eighties, there has been a regime break. Thus, it is not possible, using the structure estimated for the whole sample period, to conclude that the debt-GDP ratio is diverging.info:eu-repo/semantics/publishedVersio

Vectors to ore in replacive volcanogenic massive sulfide (VMS) deposits of the northern Iberian Pyrite Belt: Mineral zoning, whole rock geochemistry, and application of portable X-ray fluorescence

In this work we have performed a detailed study of vectors to ore to a representative volcanic-rock-hosted replacive volcanogenic massive sulfide (VMS) deposit located in the northern Iberian Pyrite Belt (Spain), the Aguas Teñidas deposit. The investigated vectors include the following: (1) mineralogical zoning, (2) host sequence characterization and mineralized unit identification based on whole rock geochemistry discrimination diagrams, (3) study of the characteristics and behaviour of whole rock geochemical anomalies around the ore (e.g. alteration-related compositional changes, characteristics and extent of geochemical halos of indicative elements such as Cu, Zn, Pb, Sb, Tl, and Ba around the deposit), and (4) application of portable X-ray fluorescence (p-XRF) analysis to the detection of the previous vectors

A comprehensive study of protein-mesoporous-macroporous silica interactions by extended canonical variate analysis of Raman spectra

Understanding the protein-support interactions is of major importance when manufacturing bionanomaterials to a certain application. These interactions can be the cause for enhanced properties or denaturation phenomena in the target protein. Raman spectroscopy was applied to a bionanomaterial comprehending the protein beta-galactosidase immobilized by physical adsorption into a mesoporous-macroporous silica material, with a nanoporous network consisting of 9-nm mesopores and 200-nm macropores. Raman spectra of the bionanomaterial evidenced a complex amount of differences related to the Raman shifts, intensities, band enlargement, appearance of new bands, and overlapping, in comparison with the silica support and the protein spectra. To help in the analysis of the Raman spectra and in the inspection of possible protein-support interactions, ECVA (extended canonical variate analysis) was used as a chemometric complementary tool, dividing the spectra into four segments: 1 (3,100 to 2,800 cm(-1)), 2 (1,800 to 1,500 cm(-1)), 3 (1,500 to 1,200 cm(-1)), and 4 (1,200 to 900 cm(-1)). Major alterations in the Amide I band (1,800 to 1,500 cm(-1)) and the amino acid band regions demonstrated possible structure alterations to a non-native form of the protein beta-galactosidase. Also, other minor alterations were observed in other spectral regions (3,100 to 2,800 cm(-1),1,500 to 1,200 cm(-1), and 1,200 to 900 cm(-1)) also representative of protein structure alteration due to protein-support interactions

Detecting and monitoring the development stages of wild flowers and plants using computer vision: approaches, challenges and opportunities

Wild flowers and plants play an important role in protecting biodiversity and providing various ecosystem services. However, some of them are endangered or threatened and are entitled to preservation and protection. This study represents a first step to develop a computer vision system and a supporting mobile app for detecting and monitoring the development stages of wild flowers and plants, aiming to contribute to their preservation. It first introduces the related concepts. Then, surveys related work and categorizes existing solutions presenting their key features, strengths, and limitations. The most promising solutions and techniques are identified. Insights on open issues and research directions in the topic are also provided. This paper paves the way to a wider adoption of recent results in computer vision techniques in this field and for the proposal of a mobile application that uses YOLO convolutional neural networks to detect the stages of development of wild flowers and plants