Entropy diversity in multi-objective particle swarm optimization

Multi-objective particle swarm optimization (MOPSO) is a search algorithm based on social behavior. Most of the existing multi-objective particle swarm optimization schemes are based on Pareto optimality and aim to obtain a representative non-dominated Pareto front for a given problem. Several approaches have been proposed to study the convergence and performance of the algorithm, particularly by accessing the final results. In the present paper, a different approach is proposed, by using Shannon entropy to analyzethe MOPSO dynamics along the algorithm execution. The results indicate that Shannon entropy can be used as an indicator of diversity and convergence for MOPSO problems.

From here to diversity: globalization and intercultural dialogues

From Here to Diversity: Globalization and Intercultural Dialogues sees interculturalism as movement, transit, travel, the dynamics between cultures. Contemporary intercultural travel is a global journey, a circumnavigation at the speed of light that underwrites all the comings and goings, the departures and arrivals, the transmissions and receptions that are implicit in this title. Hence, From Here to Diversity examines the motivations, characteristics and implications of cultural interactions in their perpetual movement, devoid of spatial or temporal borders, in a dangerous but stimulating indefinition of limits. In the contemporary intercultural dialogue, new voices are making themselves heard, as valuable sources of study: the voices of women; non-occidentals; the non-powerful; forgotten narratives of a past that was as intercultural as the present (after all, what is colonialism other than a perverse form of interculturality?); global entertainment; tourism; oral literature; diaries; mythical narratives; the cinema; ethnography; new teachings, among so many others. Because this project is also intercultural at its source and subject, From Here to Diversity: Globalization and Intercultural Dialogues adds to the coherence of the project by including contributions from the most wide-ranging backgrounds and nationalities, without fear of the alterity that, after all, we propose to study.

Demand response in future power systems management – a conceptual framework and simulation tool

Mestrado em Engenharia Electrotécnica – Sistemas Eléctricos de Energia

Diversity and characterisation of coagulasenegative staphylococci isolated from healthy individuals in Portugal

In the past few years the interest in coagulase-negative staphylococci (CoNS) has significantly increased in human medicine. CoNS are common commensal colonisers of the human skin, although now also recognised as major nosocomial pathogens. Over the last decades, several studies have been carried out in order to understand the pathogenicity mechanisms of CoNS. The well known determinants in the pathogenesis of CoNS infections are their ability to form biofilms and an exceptional resistance to several antibiotics. Nevertheless, there is a lack of studies regarding the commensal lifestyle of these microorganisms. Additionally, it is now hypothesised that commensal bacteria might be a reservoir of pathogenic determinants. Therefore, the work described throughout this thesis was aimed to perform a phenotypic and genotypic characterisation of different CoNS species isolated from healthy Portuguese individuals. A total of 61 CoNS isolates, comprising 7 different species, were obtained and characterised at the level of biofilm formation and antibiotic susceptibility profiles. According to the results, biofilm formation ability and presence of biofilm-associated genes were commonly found features, highlighting their pivotal role in the colonising lifestyle of CoNS. This study also addressed the correlation between phenotypic and genotypic characteristics of biofilm formation, corroborating and raising questions about the importance of some genes in this process. Moreover, it was observed a great proportion of isolates with decreased susceptibility and multiple resistances to some important antibiotics. A significant association between antibiotic resistance and biofilm formation was also demonstrated, and some hypotheses about the nature of such association were provided. Lastly, the expression patterns of two biofilm-associated genes at two distinct biofilm developmental stages were determined, confirming their importance in the accumulative stage of biofilm formation. Overall, the results presented in this thesis indicate that staphylococcal skin flora might be an important reservoir of potentially pathogenic bacteria and, simultaneously, bring to light new perceptions about the molecular basis of staphylococcal biofilm formation, and the nature of the association between antibiotic resistance and biofilm formation.

Quantification of endocrine disruptors and pesticides in water by gas chromatography–tandem mass spectrometry. Method validation using weighted linear regression schemes

Amulti-residue methodology based on a solid phase extraction followed by gas chromatography–tandem mass spectrometry was developed for trace analysis of 32 compounds in water matrices, including estrogens and several pesticides from different chemical families, some of them with endocrine disrupting properties. Matrix standard calibration solutions were prepared by adding known amounts of the analytes to a residue-free sample to compensate matrix-induced chromatographic response enhancement observed for certain pesticides. Validation was done mainly according to the International Conference on Harmonisation recommendations, as well as some European and American validation guidelines with specifications for pesticides analysis and/or GC–MS methodology. As the assumption of homoscedasticity was not met for analytical data, weighted least squares linear regression procedure was applied as a simple and effective way to counteract the greater influence of the greater concentrations on the fitted regression line, improving accuracy at the lower end of the calibration curve. The method was considered validated for 31 compounds after consistent evaluation of the key analytical parameters: specificity, linearity, limit of detection and quantification, range, precision, accuracy, extraction efficiency, stability and robustness.

Frequency of TERT promoter mutations in human cancers

Reactivation of telomerase has been implicated in human tumorigenesis, but the underlying mechanisms remain poorly understood. Here we report the presence of recurrent somatic mutations in the TERT promoter in cancers of the central nervous system (43%), bladder (59%), thyroid (follicular cell-derived, 10%) and skin (melanoma, 29%). In thyroid cancers, the presence of TERT promoter mutations (when occurring together with BRAF mutations) is significantly associated with higher TERT mRNA expression, and in glioblastoma we find a trend for increased telomerase expression in cases harbouring TERT promoter mutations. Both in thyroid cancers and glioblastoma, TERT promoter mutations are significantly associated with older age of the patients. Our results show that TERT promoter mutations are relatively frequent in specific types of human cancers, where they lead to enhanced expression of telomerase.

Levantamento, reparação e beneficiação do simulador TERCO PST 2200 do Laboratório de Sistemas de Energia do ISEP

Este trabalho é baseado no simulador de redes PST2200 do Laboratório de Sistemas de Energia (LSE) pois está avariado com vários problemas conhecidos, designadamente: - Defeito de isolamento (disparo de diferencial), - Desregulação da velocidade da máquina primária (motor DC), - Circuito de excitação da máquina síncrona inoperacional, - Inexistência de esquemas elétricos dos circuitos do simulador, - Medidas desreguladas e com canais de medida com circuito impresso queimado. O trabalho executado foi: - O levantamento e desenho de raiz (não existe qualquer manual) dos esquemas dos 10 módulos do simulador, designadamente naqueles com avaria ou com desempenho problemático a fim de que se possa ter uma visão mais pormenorizada dos circuitos e seus problemas, por forma a intervir para os minimizar e resolver, - Foi realizado o diagnóstico de avaria do simulador e foram propostas soluções para os mesmos, - Realizaram-se as intervenções propostas e aprovadas. Nas intervenções realizadas, os princípios orientadores foram: - Aumentar a robustez do equipamento por forma a garantir a sua integridade a utilizações menos apropriados e manobras 'exóticas' próprias de alunos, que pela sua condição, estão em fase de aprendizagem, - Atualizar o equipamento, colocando-o em sintonia com o 'estado da arte', - Como fator de valorização suplementar, foi concebida e aplicada a supervisão remota do funcionamento do simulador através da rede informática. Foram detetados inúmeros erros: - Má ligação do motor de corrente continua ao variador, resultando a falta de controlo da frequência da rede do sistema, - Ligações entre painéis trocadas resultando em avarias diversas das fontes de alimentação, - Cartas eletrónicas de medidas avariadas e que além de se reparar, foram também calibradas. Devido ao mecenato da empresa Schnitt + Sohn participando monetariamente, fez-se o projeto de alteração e respetiva execução de grande parte do simulador aumentando a fiabilidade do mesmo, diminuindo assim a frequência das avarias naturais mais as que acontecem involuntariamente devido a este ser um instrumento didático. Além do trabalho elétrico, foi feito muito trabalho de chaparia para alteração de estrutura e suporte do material com diferenças de posicionamento. Neste trabalho dá-se também alguns exemplos de cálculo e simulação das redes de transporte que se pode efetuar no simulador como estudo e simulação de avarias num sistema produtivo real. Realizou-se a monitorização de dois aparelhos indicadores de parâmetros de energia (Janitza UMG96S) através duma rede com dois protocolos ethernet e profibus utilizando o plc (Omron CJ2M) como valorização do trabalho.

Utilization of different encryption schemes for securing SCADA component communication

A vital role is being played by SCADA Communication for Supervisory Control and Data acquisition (SCADA) Monitoring Ststems. Devices that are designed to operate in safety-critical environments are usually designed to failsafe, but security vulnerabilities could be exploited by an attacker to disable the fail-safe mechanisms. Thus these devices must not onlybe designed for safety but also for security. This paper presents a study of the comparison of different Encryption schemes for securing SCADA Component Communication. The encryption schemes such as Symetric Key Encrypton in Wireless SCADA Environment, Assymmetric-key Encryption to Internet SCADA, and the Cross Crypto Scheme Cipher to secure communication for SCADA are analysed and the outcome is evaluated.

A sensor classification strategy for robotic manipulators

In practice the robotic manipulators present some degree of unwanted vibrations. The advent of lightweight arm manipulators, mainly in the aerospace industry, where weight is an important issue, leads to the problem of intense vibrations. On the other hand, robots interacting with the environment often generate impacts that propagate through the mechanical structure and produce also vibrations. In order to analyze these phenomena a robot signal acquisition system was developed. The manipulator motion produces vibrations, either from the structural modes or from endeffector impacts. The instrumentation system acquires signals from several sensors that capture the joint positions, mass accelerations, forces and moments, and electrical currents in the motors. Afterwards, an analysis package, running off-line, reads the data recorded by the acquisition system and extracts the signal characteristics. Due to the multiplicity of sensors, the data obtained can be redundant because the same type of information may be seen by two or more sensors. Because of the price of the sensors, this aspect can be considered in order to reduce the cost of the system. On the other hand, the placement of the sensors is an important issue in order to obtain the suitable signals of the vibration phenomenon. Moreover, the study of these issues can help in the design optimization of the acquisition system. In this line of thought a sensor classification scheme is presented. Several authors have addressed the subject of the sensor classification scheme. White (White, 1987) presents a flexible and comprehensive categorizing scheme that is useful for describing and comparing sensors. The author organizes the sensors according to several aspects: measurands, technological aspects, detection means, conversion phenomena, sensor materials and fields of application. Michahelles and Schiele (Michahelles & Schiele, 2003) systematize the use of sensor technology. They identified several dimensions of sensing that represent the sensing goals for physical interaction. A conceptual framework is introduced that allows categorizing existing sensors and evaluates their utility in various applications. This framework not only guides application designers for choosing meaningful sensor subsets, but also can inspire new systems and leads to the evaluation of existing applications. Today’s technology offers a wide variety of sensors. In order to use all the data from the diversity of sensors a framework of integration is needed. Sensor fusion, fuzzy logic, and neural networks are often mentioned when dealing with problem of combing information from several sensors to get a more general picture of a given situation. The study of data fusion has been receiving considerable attention (Esteban et al., 2005; Luo & Kay, 1990). A survey of the state of the art in sensor fusion for robotics can be found in (Hackett & Shah, 1990). Henderson and Shilcrat (Henderson & Shilcrat, 1984) introduced the concept of logic sensor that defines an abstract specification of the sensors to integrate in a multisensor system. The recent developments of micro electro mechanical sensors (MEMS) with unwired communication capabilities allow a sensor network with interesting capacity. This technology was applied in several applications (Arampatzis & Manesis, 2005), including robotics. Cheekiralla and Engels (Cheekiralla & Engels, 2005) propose a classification of the unwired sensor networks according to its functionalities and properties. This paper presents a development of a sensor classification scheme based on the frequency spectrum of the signals and on a statistical metrics. Bearing these ideas in mind, this paper is organized as follows. Section 2 describes briefly the robotic system enhanced with the instrumentation setup. Section 3 presents the experimental results. Finally, section 4 draws the main conclusions and points out future work.

Fractional derivatives: probability interpretation and frequency response of rational approximations

The theory of fractional calculus (FC) is a useful mathematical tool in many applied sciences. Nevertheless, only in the last decades researchers were motivated for the adoption of the FC concepts. There are several reasons for this state of affairs, namely the co-existence of different definitions and interpretations, and the necessity of approximation methods for the real time calculation of fractional derivatives (FDs). In a first part, this paper introduces a probabilistic interpretation of the fractional derivative based on the Grünwald-Letnikov definition. In a second part, the calculation of fractional derivatives through Padé fraction approximations is analyzed. It is observed that the probabilistic interpretation and the frequency response of fraction approximations of FDs reveal a clear correlation between both concepts.

Analysis of the Van der Pol oscillator containing derivatives of fractional order

In this paper a modified version of the classical Van der Pol oscillator is proposed, introducing fractional-order time derivatives into the state-space model. The resulting fractional-order Van der Pol oscillator is analyzed in the time and frequency domains, using phase portraits, spectral analysis and bifurcation diagrams. The fractional-order dynamics is illustrated through numerical simulations of the proposed schemes using approximations to fractional-order operators. Finally, the analysis is extended to the forced Van der Pol oscillator.

Low frequency of TERT promoter mutations in gastrointestinal stromal tumors (GISTs)

Somatic mutations in the promoter region of telomerase reverse transcriptase (TERT) gene, mainly at positions c.-124 and c.-146 bp, are frequent in several human cancers; yet its presence in gastrointestinal stromal tumor (GIST) has not been reported to date. Herein, we searched for the presence and clinicopathological association of TERT promoter mutations in genomic DNA from 130 bona fide GISTs. We found TERT promoter mutations in 3.8% (5/130) of GISTs. The c.-124C>T mutation was the most common event, present in 2.3% (3/130), and the c.-146C>T mutation in 1.5% (2/130) of GISTs. No significant association was observed between TERT promoter mutation and patient's clinicopathological features. The present study establishes the low frequency (4%) of TERT promoter mutations in GISTs. Further studies are required to confirm our findings and to elucidate the hypothetical biological and clinical impact of TERT promoter mutation in GIST pathogenesis.

Utilização de PAM's e Medicamentos e/ou Produtos à base de Plantas pela População do Concelho de Bragança

Introdução: Entende-se por fitoterapia a terapêutica caracterizada pelo uso de plantas medicinais nas diferentes formas farmacêuticas com finalidade terapêutica, usada assim para prevenir, atenuar ou curar um estado patológico. Objetivos: Caracterizar a utilização de plantas aromáticas e medicinais (PAM´s), medicamentos e produtos à base de plantas pela população do concelho de Bragança, conhecer a fonte de indicação deste tipo de produtos, apurar a relação entre a fonte de indicação e o estado de saúde após a utilização, verificar a sua correta utilização relativa à indicação terapêutica, modo e frequência de utilização, identificar potenciais interacções medicamentosas, averiguar se os utentes informam o médico do seu uso, investigar a ocorrência de efeitos adversos e apurar a relação entre os efeitos adversos ocorridos e o género dos inquiridos. Métodos: Trata-se de um estudo observacional analítico-transversal. Nele participaram 404 indivíduos de ambos os géneros e com idades compreendidas entre os 18 e os 89 anos. A recolha de dados foi realizada entre os meses de abril e junho de 2014, através de um questionário estruturado de autopreenchimento, formado por 30 perguntas. Após a recolha dos dados procedeu-se à leitura óptica dos questionários, sendo os dados posteriormente exportados para SPSS permitindo assim o tratamento dos mesmos. Para análise estatística utilizou-se o teste do qui-quadrado considerando o nível de significância p <0,05. Resultados: Verificou-se que 53,7% dos inquiridos recorre terapeuticamente a PAM´s que inclui principalmente o uso de cidreira e camomila enquanto 33,8% faz uso de medicamentos e/ou produtos àbase de plantas nomeadamente Valdispert e Daflon. A utilização de PAM,s é motivada por autoconhecimento e indicação de familiares, amigos e vizinhos. Já os medicamentos e/ou produtos à base de plantas são utilizados maioritariamente por prescrição médica e indicação na farmácia. A ocorrência de efeitos indesejáveis foi sentida unicamente com a utilização de PAM´s e em pequena escala. Conclusão: O recurso a este tipo de produtos é uma prática bastante comum entre os moradores do concelho de Bragança, que utilizam uma grande diversidade de plantas e produtos à base de plantas para um variado leque de indicações terapêuticas, apontando a percentagem de respostas para um conhecimento dos seus efeitos terapêuticos.

Culture-dependent characterization of cyanobacterial diversity in the intertidal zones of the Portuguese coast: A polyphasic study

Cyanobacteria are important primary producers, and many are able to fix atmospheric nitrogen playing a key role in the marine environment. However, not much is known about the diversity of cyanobacteria in Portuguese marine waters. This paper describes the diversity of 60 strains isolated from benthic habitats in 9 sites (intertidal zones) on the Portuguese South and West coasts. The strains were characterized by a morphological study (light and electron microscopy) and by a molecular characterization (partial 16S rRNA, nifH, nifK, mcyA, mcyE/ndaF, sxtI genes). The morphological analyses revealed 35 morphotypes (15 genera and 16 species) belonging to 4 cyanobacterial Orders/Subsections. The dominant groups among the isolates were the Oscillatoriales. There is a broad congruence between morphological and molecular assignments. The 16S rRNA gene sequences of 9 strains have less than 97% similarity compared to the sequences in the databases, revealing novel cyanobacterial diversity. Phylogenetic analysis, based on partial 16S rRNA gene sequences showed at least 12 clusters. One-third of the isolates are potential N2-fixers, as they exhibit heterocysts or the presence of nif genes was demonstrated by PCR. Additionally, no conventional freshwater toxins genes were detected by PCR screening.

A Random Access Protocol incorporating Multi-Packet Reception, Retransmission Diversity and Successive Interference Cancellation

8th International Workshop on Multiple Access Communications (MACOM2015), Helsinki, Finland.