The role of sanctioning in the evolutionary dynamics of collective action

Tese de mestrado em Física, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2012Preventing global warming requires overall cooperation. Contributions will depend on the risk of future losses, which plays a key role in decision making. Here, I discuss an evolutionary game theoretical model in which decisions within small groups under high risk and stringent requirements toward success significantly raise the chances of coordinating to save the planet’s climate, thus escaping the tragedy of the commons. I analyze both deterministic dynamics in infinite populations, and stochastic dynamics in finite populations. I also study the impact of different types of sanctioning mechanisms in deterring non-cooperative behavior in climate negotiations, towards the mitigation of the effects of climate change. To this end, I introduce punishment in the collective-risk dilemma and study the dynamics of collective action in finite populations. I show that a significant increase in cooperation is attained whenever individuals have the opportunity to contribute (or not) to institutions that punish free riders. I investigate the impact of having local instead of global sanctioning institutions, showing that the former – which are expected to require less financial resources and which involve agreements between a smaller number of individuals – are more conducive to the prevalence of an overall cooperative behavior. In the optics of evolutionary game theory, the system dynamics is solved by means of a multidimensional stochastic Markov process. The interaction between individuals is not pairwise but it occurs in n-person games; the individuals have perception of the risk and are allowed to explore unpopulated strategies.A prevenção do aquecimento global requer cooperação global. As atuais contribuições dependerão do risco das perdas futuras, desempenhando assim um papel fundamental na tomada de decisões. Nesta tese discuto um modelo teórico para um jogo evolutivo, no qual a tomada de decisões envolvendo grupos pequenos, com alto risco e requisitos rigorosos em direção ao sucesso aumenta significativamente as hipóteses de coordenação para a salvação do clima do planeta, evitando assim a tragédia dos comuns. Tanto a dinâmica determinística em populações infinitas como a dinâmica estocástica em populações finitas são analisadas. Além disto, estudo ainda o impacto de diferentes tipos de mecanismos de sanção para desencorajar o comportamento não cooperativo nas negociações climáticas, de forma a mitigar os efeitos das alterações climáticas. Para este fim, introduzo punição no jogo evolutivo e estudo a dinâmica da ação coletiva em populações finitas. Mostro que um aumento significativo na cooperação ´e alcançado quando os indivíduos têm a oportunidade de contribuir (ou não) para as instituições que punem os chamados “free riders”. Investigo o impacto da conceção de instituições fiscalizadoras locais em vez de instituições globais, mostrando que as primeiras – das quais se espera que exijam menos recursos financeiros e que envolvam acordos entre um número menor de indivíduos – são mais favoráveis para a prevalência de um comportamento global cooperativo. Na ótica da teoria dos jogos evolutiva, a dinâmica do sistema é resolvida por meio de um processo estocástico de Markov multidimensional. A interação entre indivíduos não é entre pares, mas ocorre em jogos de n pessoas, os indivíduos têm perceção do risco e têm a capacidade de explorar estratégias despovoadas

Toxicity assessment of crude and partially purified extracts of marine Synechocystis and Synechococcus cyanobacterial strains in marine invertebrates

Among the Cyanoprokaryota, the genera Synechocystis and Synechococcus have rarely been studied with respect to potential toxicity. This is particularly true with marine environments where studies about the toxicity of cyanobacteria are restricted to filamentous forms at the warmer temperate and tropical regions and also to filamentous forms at cold seas such as the Baltic Sea. In this study, we describe the effects of cyanobacterial strains of the Synechocystis and Synechococcus genera isolated from the marine coast of Portugal, on marine invertebrates. Crude and partially purified extracts at a concentration of 100 mg/ml of freeze-dried material of the marine strains were tested for acute toxicity in nauplii of the brine shrimp Artemia salina, in the rotifer Brachionus plicatillis and in embryos of the sea urchin Paracentrotus lividus and the mussel Mytilus galloprovincialis. The cyanobacterial extracts, especially the crude extract, had an impact on A. salina nauplii. No significant toxic effects were registered against the rotifer. A negative impact of all strains was recorded on the embryonic development of the sea urchin, with toxic effects resulting in an inhibition of embryogenesis or development of smaller larvae. To the mussel embryos, the effects of cyanobacterial extracts resulted in a complete inhibition of embryogenesis. The results of all assays indicate that Synechocystis and Synechococcus marine strains contained toxic compounds to marine invertebrates

A comparison of mass parameters determination using capacitive and optical sensors

This paper presents a comparison study between the use of 1mmresolution capacitive and optical sensors for the determination of yarn mass parameters. A parallel plate capacitive sensor to determine yarn mass variations and a yarn diameter and hairiness determination solution using optical sensors and integrating optical signal processing based on Fourier analysis are described. As there is a high correlation between yarn diameter and yarn mass, it is possible to determine yarn mass and infer variations in yarn diameter and vice versa. Moreover, by optically detecting the degree of yarn hairiness, one can quantify its influence on the capacitive sensor mass variation measurements. Here we present the results of a signal processing analysis and statistical description of measurements carried out in two 100% cotton yarns with a linear mass of 59 and 295 g/km performed in yarn system quality (YSQ) machine. We conclude that an accurate yarn characterization can be carried out using optical sensors alone, reducing system’s cost and complexity and increasing efficiency.Fundação para a Ciência e a Tecnologia (FCT) - BD/19028/200

Yarn diameter and linear mass correlation

This paper focuses on the determination of the statistical correlation between yarn diameter and yarn linear mass. The experimental methods employed are based on optical analysis and on image processing techniques applied to electron microscope image. several different cotton yarns were examined over a wide range of yarn linear masses. the results indicate that diameter predicted by the relationship commonly quatode in literature can be as much as 62% smaller than those experimentally observed

Contributions of TOXICROP project for the assessment of the impacts of toxic cyanobacteria in agriculture †

Water contaminated with microcystins (MCs) or other cyanotoxins is recurrently used in agriculture and for crop irrigation. Several deleterious effects of MCs in plants that may impair crop productivity, including a decrease in growth and tissue necrosis, as well as an inhibition of photosynthesis and metabolic changes, have been reported. Studies also revealed a significant accumulation of MCs in edible tissues and plant organs, which raise concerns related to food safety. The European project TOXICROP precisely tackles this environmental problem. The main aims of the project are to map agricultural risk areas of cyanotoxin occurrence, to assess the fate of cyanotoxins in crops, and evaluate the impacts of using low-quality water for crop irrigation. The project also develops research on water remediation, exploring nature-based technologies. Here, we review part of the research carried out in the project, concerning the toxicity of cyanotoxins in crops. The research from TOXICROP Consortium has revealed for instance that adult strawberry or faba bean plants are susceptible to moderate concentrations of MCs (10 to 20 µg MCs/L). Furthermore, experiments with faba bean and common wheat grown in sterile (microorganism-free) and non-sterile (microorganism-rich) soil, watered with 100 μg MCs/L, revealed that native rhizospheric microbiota play an important role in the mitigation of the phytotoxic impact of MCs on plant growth, reducing toxin accumulation in both soils and plant tissues. Our studies also revealed that leaf vegetables, such as lettuce and spinach, growing in hydroponics are more susceptible to MCs than to the toxin, cylindrospermopsin (CYN). The lowest toxin concentrations affecting spinach and lettuce growth were 5 + 5 and 25 + 25 µg/L CYN/MC mixtures, respectively. The results also reveal that the accumulation of MCs and CYN in plants depends on the conditions in which plants grow and concentrations of toxins in the irrigation water. In some cases, MCs are accumulated in plant tissues and exceed the tolerable daily intake proposed by the World Health Organization. We highlight the importance and contributions of this research to the definition and implementation of regulatory limits for cyanotoxins in irrigation waters.info:eu-repo/semantics/publishedVersio

As inteligências múltiplas em contexto de aconselhamento de carreira : tradução portuguesa do Multiple Intelligences Developmental Assessment Scales (MIDAS)

Tese de mestrado, Psicologia (Secção de Psicologia da Educação e da Orientação), Universidade de Lisboa, Faculdade de Psicologia, 2013Este estudo tem natureza exploratória e constitui a primeira fase da adaptação Portuguesa do Multiple Intelligences Developmental Assessment Scales (MIDAS), instrumento fundamentado na Teoria da Inteligências Múltiplas de Howard Gardner, numa amostra (N = 85) de estudantes do 1º ano do ensino superior de Dança, Psicologia e Economia. Apesar das limitações interpretativas devido às dimensões da amostra, o conjunto dos dados revela evidências que apoiam a precisão e a validade da medida. Os coeficientes Alfa possuem a amplitude entre .46 e .79, com mediana .75 e os coeficientes teste-reteste oscilam entre .30 e .79, com mediana .66, destacando-se os fracos indicadores da Escala Intrapessoal, cujos conteúdos necessitam de revisão. Nos resultados do MIDAS há alguns índices que tendem a discriminar congruentemente os estudantes pelos cursos. Na comparação múltipla das diferenças entre as médias, os resultados médios são superiores dos alunos de Dança na Escala Corporal-Quinestésica e os resultados são superiores dos alunos de Economia na Escala Intrapessoal. De referir ainda que os resultados do MIDAS tendem a diferenciar os estudantes em função do nível de escolaridade dos pais, cuja tendência vai no sentido dos participantes com família de nível superior apresentarem médias superiores nas Escalas Espacial, Lógico-Matemática e Intrapessoal, comparativamente ao grupo com escolaridade mais baixa. Estes dados são encorajadores da continuação da validação da medida MIDAS e do respectivo aperfeiçoamento, pelas possibilidades que esta medida representa em aconselhamento da carreira, com estudantes do ensino superior.This exploratory study represents the first phase of the Portuguese adaptation of the Multiple Intelligences Developmental Assessment Scales (MIDAS), instrument which is based in Howard Gardner’s Theory of Multiple Intelligences, in a sample (N=80) of first year college students of Dance, Psychology and Economy. Despite the interpretive limitations due to the sample size, the data supports the measure’s reliability and validity. The Alfa coefficients vary from .46 to .79, with a median of .75, and the test-retest coefficients vary from .30 to .79, with a median of .66, from which the Intrapersonal Scale stands out with both low coefficients, suggesting that its contents should be revised. In the MIDAS results there are some pointers that tend to show differentiated results according to course. The data from the means multiple comparisons show higher results in the Dance students Bodily-Quinestetic Scale, and in the Economy students Intrapersonal Scale. The MIDAS results also tend to differentiate the students according to their parents level of education, in which the students whose families have college education show higher mean results in the Spatial, Logical-Mathematical and Intrapersonal Scales, when compared to the group of lower education. These encouraging results point out the need to continue the validation process and perfecting of MIDAS, due to the potential this instrument represents to the career counseling of college students

Trauma ocular

Esta webaula contempla as principais informações sobre o trauma ocular: Avaliação, tratamento e prognósticos

Consensus and polarization in competing complex contagion processes

Vasconcelos, V. V., Levin, S. A., & Pinheiro, F. L. (2019). Consensus and polarization in competing complex contagion processes. Journal of The Royal Society Interface, 16(155), [20190196]. https://doi.org/10.1098/rsif.2019.0196The rate of adoption of new information depends on reinforcement from multiple sources in a way that often cannot be described by simple contagion processes. In such cases, contagion is said to be complex. Complex contagion happens in the diffusion of human behaviours, innovations and knowledge. Based on that evidence, we propose a model that considers multiple, potentially asymmetric and competing contagion processes and analyse its respective population-wide dynamics, bringing together ideas from complex contagion, opinion dynamics, evolutionary game theory and language competition by shifting the focus from individuals to the properties of the diffusing processes. We show that our model spans a dynamical space in which the population exhibits patterns of consensus, dominance, and, importantly, different types of polarization, a more diverse dynamical environment that contrasts with single simple contagion processes. We show how these patterns emerge and how different population structures modify them through a natural development of spatial correlations: structured interactions increase the range of the dominance regime by reducing that of dynamic polarization, tight modular structures can generate structural polarization, depending on the interplay between fundamental properties of the processes and the modularity of the interaction network.authorsversionpublishersversionpublishe

Yarn hairiness characterization using two orthogonal directions

We demonstrate that one can adequately characterize Yarn hairiness by imaging the yarn along a single projection direction using coherent optical processing. A system that simultaneously characterizes the yarn hairiness along two orthogonal projection directions was constructed. Provided that a sufficiently high number of yarn segments are sampled, a strong statistical correlation is obtained between the results in each direction. The resulting images are generated using coherent optical signal processing with a Fourier high-pass spatial filter. This filter blocks the yarn core and produces a signal that highlights the sharp transitions in the transmission of the yarn. Essentially, only the small fibres responsible for the hairiness and the yarn core contours are present. Experimental results are presented for a 62-g/km yarn possessing a high degree of hairiness. Index Terms—Electronic instrumentation, optical sensors, orthogonal directions, signal processing, yarn hairiness.Fundação para a Ciência e a Tecnologia (FCT) - BD/19028/2004

Yarn parameterization and fabrics prediction using image processing

This paper presents the main characteristics and functionalities of a system based on image processing techniques applied to quality assessment of yarns. In Textile Industry we used image processing to determine yarn mass parameters as well as yarn production characteristics. A low cost solution based on a web-pc camera plus the optics of a low cost analogue microscope and a software tool based on IMAQ Vision from LabVIEW was designed. Several tests were performed and compared with other methodologies of yarn parameterization validating the proposed solution. With the results one can support that this can be an alternative solution to the traditional yarn testers, with several advantages (among others, low cost, weight, volume, easy maintenance and reduced hardware). Moreover, this yarn parameterization can be used to assess the quality of the fabrics resultant