Mass, angular-momentum, and charge inequalities for axisymmetric initial data

We present the key elements of the proof of an upper bound for angular-momentum and charge in terms of the mass for electro-vacuum asymptotically flat axisymmetric initial data sets with simply connected orbit space

A Dain Inequality with charge

We prove an upper bound for angular-momentum and charge in terms of the mass for electro-vacuum asymptotically flat axisymmetric initial data sets with simply connected orbit space

Acesso à informação e participação pública : planeamento de recursos hídricos e desenvolvimento sustentável nos Açores

O acesso à informação e participação pública são dois dos mais significativos desafios que o actual quadro de planeamento ambiental coloca a nível nacional. Nesse sentido, a presente comunicação foca-se nos trabalhos conducentes à elaboração do Plano Regional da Água e nos Estudos de Base do Plano Regional de Desenvolvimento Sustentável, ambos levados a efeito na Região Autónoma dos Açores. Concretizando-se objectivos operacionais e graus de envolvimento da comunidade diferenciados nestes dois projectos, apresentam-se as principais linhas de trabalho e discutem-se as diferentes metodologias em ambos adoptadas com vista a um exercício integrado de cidadania

Membrane selectivity versus sensor response in hydrogenated amorphous silicon CHEMFETs using a semi-empirical model

Toxic amides, such as acrylamide, are potentially harmful to Human health, so there is great interest in the fabrication of compact and economical devices to measure their concentration in food products and effluents. The CHEmically Modified Field Effect Transistor (CHEMFET) based onamorphous silicon technology is a candidate for this type of application due to its low fabrication cost. In this article we have used a semi-empirical modelof the device to predict its performance in a solution of interfering ions. The actual semiconductor unit of the sensor was fabricated by the PECVD technique in the top gate configuration. The CHEMFET simulation was performed based on the experimental current voltage curves of the semiconductor unit and on an empirical model of the polymeric membrane. Results presented here are useful for selection and design of CHEMFET membranes and provide an idea of the limitations of the amorphous CHEMFET device. In addition to the economical advantage, the small size of this prototype means it is appropriate for in situ operation and integration in a sensor array

Avaliar para aprender: um processo reflexivo e colaborativo potenciador da aprendizagem em biologia

Relatório de estágio de mestrado em Ensino de Biologia e Geologia no 3º Ciclo do Ensino Básio e no Ensino SecundárioO reconhecimento da importância da promoção da construção de uma visão da avaliação como um processo inerente à própria aprendizagem, que implica o aluno numa ação de reflexão, de interdependência positiva, de compromisso e de corresponsabilidade, e do desenvolvimento de práticas letivas em consonância com esta perspetiva, conduziu à idealização, conceção, implementação e avaliação de uma estratégia de intervenção pedagógica assente, fundamentalmente, em processos de auto e heteroavaliação num contexto colaborativo. A intervenção pedagógica desenvolveu-se na temática Fotossíntese da disciplina de Biologia e Geologia do 10º ano de escolaridade do Curso Científico-Humanístico de Ciências e Tecnologias. A consecução dos processos de auto e heteroavaliação efetuou-se através da sua operacionalização conjunta em quatro atividades de coavaliação, concebidas segundo uma estrutura dialógica, orientada para a resolução de um problema/situação problemática e, consequentemente, para a compreensão do respetivo conhecimento substantivo. A avaliação da intervenção pedagógica centrou-se na compreensão da natureza do processo de coavaliação das aprendizagens desenvolvido pelos alunos, na identificação do valor educativo atribuído pelos alunos ao papel da heteroavaliação da aprendizagem após terem experienciado este processo e na identificação de fatores de facilitação e de constrangimento na implementação de atividades de coavaliação. Os alunos desenvolveram o processo de coavaliação assumindo um posicionamento crítico sobre a sua aprendizagem e a dos colegas, tendo incidido não só na qualidade científica das explicações às situações problemáticas mas, também, na deteção das causas subjacentes a possíveis falhas e na capacidade de perspetivar ações passiveis de contribuir para o desenvolvimento da aprendizagem. A heteroavaliação é visualizada pelos alunos como um processo positivo para a aprendizagem. A sua utilidade na promoção da aprendizagem e o posicionamento ético assumido pelos alunos na construção de um discurso avaliativo, justo e coerente são apontados como fatores facilitadores da implementação de atividades de coavaliação. O receio em cometer erros na avaliação do trabalho dos colegas e a falta de conhecimentos necessários para efetuar essa mesma avaliação são os principais constrangimentos sentidos pelos alunos.The recognition of the importance of promoting the construction of a vision of evaluation as a process inherent to learning, which involves students in an action of reflection, positive interdependence, commitment and co-responsibility, and the need to develop practices in this perspective, led to the idealization, design, implementation and evaluation of an pedagogical strategy based primarily on processes of peer and self-assessment in a collaborative context. The pedagogical intervention was developed in the thematic Photosynthesis in the field of Biology and Geology of the 10th grade on the course of Scientific-Humanistic of Sciences and Technologies. The attainment of the peer and self-assessment processes was made up through its joint operational in four co-assessment activities, designed according to a dialogical structure, oriented to the resolution of an question/problem and, consequently, for understanding of the respective scientific knowledge. The evaluation of pedagogical intervention focused on understanding the nature of the peer and self-assessment process developed by students, in identifying the educational value attributed by the students to the role of peer-evaluation of their learnings after they experienced this process and to identify facilitating factors and constraints to the implementation of peer and self-assessment activities. Students developed the peer and self-assessment process assuming a critical position, about their learning and the learnings of their colleagues, which covered not only the quality of scientific explanations to problematic situations, but also the detection of possible underlying causes of failures and the ability to perspective actions that contribute to the development of learning. Students showed a vision of peer-assessment as a positive process for learning. As factors that facilitate the implementation of peer and self-assessment activities students indicated their usefulness in the development of learning and the ethical position they made in building a fair and consistent evaluative discourse. As constraints were indicated the fears about making mistakes when evaluating the work of colleagues and lack of knowledge necessary to make that evaluations

Macroscopic Electromagnetic Response of Arbitrarily Shaped Spatially Dispersive Bodies formed by Metallic Wires

In media with strong spatial dispersion the electric displacement vector and the electric field are typically linked by a partial differential equation in the bulk region. The objective of this work is to highlight that in the vicinity of an interface the relation between the macroscopic fields cannot be univocally determined from the bulk response of the involved materials, but requires instead the knowledge of internal degrees of freedom of the materials. We derive such relation for the particular case of "wire media", and describe a numerical formalism that enables characterizing the electromagnetic response of arbitrarily shaped spatially dispersive bodies formed by arrays of crossed wires. The possibility of concentrating the electromagnetic field in a narrow spot by tapering a metamaterial waveguide is discussed.Comment: 34 pages, 10 figure

Response of key stress-related genes of the seagrass Posidonia oceanica in the vicinity of submarine volcanic vents

Submarine volcanic vents are being used as natural laboratories to assess the effects of increased ocean acidity and carbon dioxide (CO2) concentration on marine organisms and communities. However, in the vicinity of volcanic vents other factors in addition to CO2, which is the main gaseous component of the emissions, may directly or indirectly confound the biota responses to high CO2. Here we used for the first time the expression of antioxidant and stress-related genes of the seagrass Posidonia oceanica to assess the stress levels of the species. Our hypothesis is that unknown factors are causing metabolic stress that may confound the putative effects attributed to CO2 enrichment only. We analyzed the expression of 35 antioxidant and stress-related genes of P. oceanica in the vicinity of submerged volcanic vents located in the islands of Ischia and Panarea, Italy, and compared them with those from control sites away from the influence of vents. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was used to characterize gene expression patterns. Fifty-one percent of genes analyzed showed significant expression changes. Metal detoxification genes were mostly down-regulated in relation to controls at both Ischia and Panarea, indicating that P. oceanica does not increase the synthesis of heavy metal detoxification proteins in response to the environmental conditions present at the two vents. The up-regulation of genes involved in the free radical detoxification response (e.g., CAPX, SODCP and GR) indicates that, in contrast with Ischia, P. oceanica at the Panarea site faces stressors that result in the production of reactive oxygen species, triggering antioxidant responses. In addition, heat shock proteins were also activated at Panarea and not at Ischia. These proteins are activated to adjust stress-accumulated misfolded proteins and prevent their aggregation as a response to some stressors, not necessarily high temperature. This is the first study analyzing the expression of target genes in marine plants living near natural CO2 vents. Our results call for contention to the general claim of seagrasses as "winners" in a high-CO2 world, based on observations near volcanic vents. Careful consideration of factors that are at play in natural vents sites other than CO2 and acidification is required. This study also constitutes a first step for using stress-related genes as indicators of environmental pressures in a changing ocean.project HighGrass "High-CO2 effects on seagrass photosynthetic ecophysiology" [PTDC/MAREST/3687/2012]; MIUR Italian flagship project RITMARE; ESF COST Action "Seagrass Productivity: from genes to ecosystem management

A Deformation Quantization Theory for Non-Commutative Quantum Mechanics

We show that the deformation quantization of non-commutative quantum mechanics previously considered by Dias and Prata can be expressed as a Weyl calculus on a double phase space. We study the properties of the star-product thus defined, and prove a spectral theorem for the star-genvalue equation using an extension of the methods recently initiated by de Gosson and Luef.Comment: Submitted for publicatio

A thiophene-based dicyanovinyl as an anion chemosensor

In recent years, push-pull dicyanovinyl derivatives have been reported for several optical applications, including as fluorescent probes for cyanide ion detection. In presence of cyanide ions, this type of compound exhibits an ICT mechanism associated with the addition of the cyanide ion to the β-position of the dicyanovinyl group, due to the strong electron-withdrawing effect of the cyano groups. These structural changes caused by the addition reaction are accompanied by changes in the probe’s absorption and emission. In this work, we report a thiophene-based dicyanovinyl derivative and its prospective application as an anion chemosensor. The photophysical characterization was carried out in acetonitrile and aqueous acetonitrile solutions. Preliminary sensing assays in the presence of various anions of biological, medicinal and environmental relevance were conducted and the interaction with CN- was further explored through spectrophotometric titrations