Discrete fractional order system vibrations

A theory of free vibrations of discrete fractional order (FO) systems with a finite number of degrees of freedom (dof) is developed. A FO system with a finite number of dof is defined by means of three matrices: mass inertia, system rigidity and FO elements. By adopting a matrix formulation, a mathematical description of FO discrete system free vibrations is determined in the form of coupled fractional order differential equations (FODE). The corresponding solutions in analytical form, for the special case of the matrix of FO properties elements, are determined and expressed as a polynomial series along time. For the eigen characteristic numbers, the system eigen main coordinates and the independent eigen FO modes are determined. A generalized function of visoelastic creep FO dissipation of energy and generalized forces of system with no ideal visoelastic creep FO dissipation of energy for generalized coordinates are formulated. Extended Lagrange FODE of second kind, for FO system dynamics, are also introduced. Two examples of FO chain systems are analyzed and the corresponding eigen characteristic numbers determined. It is shown that the oscillatory phenomena of a FO mechanical chain have analogies to electrical FO circuits. A FO electrical resistor is introduced and its constitutive voltage–current is formulated. Also a function of thermal energy FO dissipation of a FO electrical relation is discussed.

Deixem que eu me (re)encontre

O presente relatório reflete um projeto de investigação no âmbito do Mestrado em Educação e Intervenção Social, que assume como metodologia a Investigação Ação-Participativa, e que é desenvolvido e construído com um grupo de pessoas desempregadas. Assim, e contando com os participantes como co-construtores de todo o processo, foi necessário elaborar uma análise e caracterização da realidade da qual surgiram alguns problemas. É com base neles que o projeto começa a ser delineado, tendo por base a educação não-formal de adultos, e recorrendo a ações e atividades para se alcançarem os objetivos definidos e, desta forma, ser possível compreender qual o impacto que ele teve na vida dos participantes. Denominado por “Deixem que eu me (Re)Encontre”, este projeto de investigação pretendeu proporcionar momentos de desenvolvimento da autoestima, de redescoberta de capacidades e competências, e de criação de uma rede de suporte afetivo, estimulando nos participantes a apropriação de um poder de intervenção, gerador de mudança nas suas vidas, que há muito se tinha perdido.

Stochastic model of transcription initiation of closely spaced promoters in escherichia coli

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Introducing numerical analysis tools in engineering: a Scilab user case in electronics course

Software tools in education became popular since the widespread of personal computers. Engineering courses lead the way in this development and these tools became almost a standard. Engineering graduates are familiar with numerical analysis tools but also with simulators (e.g. electronic circuits), computer assisted design tools and others, depending on the degree. One of the main problems with these tools is when and how to start use them so that they can be beneficial to students and not mere substitutes for potentially difficult calculations or design. In this paper a software tool to be used by first year students in electronics/electricity courses is presented. The growing acknowledgement and acceptance of open source software lead to the choice of an open source software tool – Scilab, which is a numerical analysis tool – to develop a toolbox. The toolbox was developed to be used as standalone or integrated in an e-learning platform. The e-learning platform used was Moodle. The first approach was to assess the mathematical skills necessary to solve all the problems related to electronics and electricity courses. Analysing the existing circuit simulators software tools, it is clear that even though they are very helpful by showing the end result they are not so effective in the process of the students studying and self learning since they show results but not intermediate steps which are crucial in problems that involve derivatives or integrals. Also, they are not very effective in obtaining graphical results that could be used to elaborate reports and for an overall better comprehension of the results. The developed tool was based on the numerical analysis software Scilab and is a toolbox that gives their users the opportunity to obtain the end results of a circuit analysis but also the expressions obtained when derivative and integrals calculations, plot signals, obtain vector diagrams, etc. The toolbox runs entirely in the Moodle web platform and provides the same results as the standalone application. The students can use the toolbox through the web platform (in computers where they don't have installation privileges) or in their personal computers by installing both the Scilab software and the toolbox. This approach was designed for first year students from all engineering degrees that have electronics/electricity courses in their curricula.

Reproduction of Leishmania (Leishmania ) infantum chagasi in conditioned cell culture growth medium

Leishmanias can be produced by inoculation in conditioned McCoy cell culture growth medium (CGM). Leishmania (Leishmania) infantum chagasi (100 parasites) grown in NNN medium was inoculated in 2.5 mL CGM, kept in plates (24 wells) and its multiplication was observed for five days (120 hours). After day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes). The reproduction of the leishmanias was observed every 24 hours and the number of parasites was calculated by counting the parasites in a drop of 10 µ L and photomicrographied. So the number of Leishmanias was adjusted to 1 mL volume. The advantage of the technique by isolation of Leishmania in CGM demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (10² promastigotes) used as inoculum. Additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times) as observed by growth kinetics, within a shorter time. These results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of Leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias) or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.

Geomecânica aplicada à estabilidade de explorações mineiras bench and fill: o caso do jazigo de Feitais, Minas de Aljustrel

Este trabalho pretende abordar a importância de um estudo geomecânico no apoio à otimização e estabilidade de explorações subterrâneas por subníveis, com criação de bancadas e posterior enchimento. O presente envolveu um estudo geológico-geotécnico em quinze galerias situadas a muro, teto e corpo da mineralização com o levantamento das características mais relevantes do maciço rochoso para aplicação das classificações geomecânicas, englobando uma amostragem de mais de 1780 descontinuidades, obtendo um modelo cartográfico subterrâneo com um panorama geral da qualidade do maciço rochoso intercetado pelas escavações nas diferentes zonas. Os dados dos levantamentos de campo levaram à criação de uma base de dados com a aplicação das classificações geomecânicas Q-System, RMR e GSI, por galeria e, em seguida, por zona, com proposta de classe de sustimento a aplicar em cada local, pelo ábaco de Barton, em conjunto com a determinação de parâmetros geomecânicos fundamentais ao refinamento do conhecimento geológico-geotécnico das unidades litológicas em estudo. Na parte final, focando a localização da massa mineralizada de Feitais é efetuada uma abordagem relativa à estabilidade das cavidades geradas pelo desmonte em bancada entre subníveis, com respetivo dimensionamento das larguras admissíveis, em condições de segurança, através da relação entre o número de estabilidade e raio hidráulico, pelo método do gráfico de estabilidade. Com esta metodologia de caracterização geológico geotécnica, é pretendido efetuar um ponto de partida à criação de um modelo geomecânico comportamental do jazigo de Feitais, Mina de Aljustrel, contando com um processo inicial de apoio ao planeamento mineiro aplicado ao método de desmonte em bancada e posterior enchimento por subníveis, atuando nos parâmetros de estabilidade e apoio à extração, favorecendo assim a segurança das operações de trabalho em conjunto com um apoio de otimização da extração.

Role of iron in the nitric oxide-mediated fungicidal mechanism of IFN-gamma-activated murine macrophages against Paracoccidioides brasiliensis conidia

Iron is an essential growth element of virtually all microorganisms and its restriction is one of the mechanisms used by macrophages to control microbial multiplication. Paracoccidioides brasiliensis, the agent of paracoccidioidomycosis, an important systemic mycosis in Latin America, is inhibited in its conidia-to-yeast conversion in the absence of iron. We studied the participation of iron in the nitric oxide (NO)-mediated fungicidal mechanism against conidia. Peritoneal murine macrophages activated with 50U/mL of IFN-gamma or treated with 35 µM Deferoxamine (DEX) and infected with P. brasiliensis conidia, were co-cultured and incubated for 96 h in the presence of different concentrations of holotransferrin (HOLO) and FeS0(4). The supernatants were withdrawn in order to assess NO2 production by the Griess method. The monolayers were fixed, stained and observed microscopically. The percentage of the conidia-to-yeast transition was estimated by counting 200 intracellular propagules. IFN-gamma-activated or DEX-treated Mthetas presented marked inhibition of the conidia-to-yeast conversion (19 and 56%, respectively) in comparison with non-activated or untreated Mthetas (80%). IFN-gamma-activated macrophages produced high NO levels in comparison with the controls. Additionally, when the activated or treated-macrophages were supplemented with iron donors (HOLO or FeSO4), the inhibitory action was reversed, although NO production remained intact. These results suggest that the NO-mediated fungicidal mechanism exerted by IFN-gamma-activated macrophages against P. brasiliensis conidia, is dependent of an iron interaction.

Effects of Acute Autonomic Modulation on Atrial Conduction Delay and Local Electrograms Duration in Paroxysmal Atrial Fibrillation

Slowed atrial conduction may contribute to reentry circuits and vulnerability for atrial fibrillation (AF). The autonomic nervous system (ANS) has modulating effects on electrophysiological properties. However, complex interactions of the ANS with the arrhythmogenic substrate make it difficult to understand the mechanisms underlying induction and maintenance of AF. AIM: To determine the effect of acute ANS modulation in atrial activation times in patients (P) with paroxysmal AF (PAF). METHODS AND RESULTS: 16P (9 men; 59±14years) with PAF, who underwent electrophysiological study before AF ablation, and 15P (7 men; 58±11years) with atrioventricular nodal reentry tachycardia, without documentation or induction of AF (control group). Each group included 7P with arterial hypertension but without underlying structural heart disease. The study was performed while off drugs. Multipolar catheters were placed at the high right atrium (HRA), right atrial appendage (RAA), coronary sinus (CS) and His bundle area (His). At baseline and with HRA pacing (600ms, shortest propagated S2) we measured: i) intra-atrial conduction time (IACT, between RAA and atrial deflection in the distal His), ii) inter-atrial conduction time (interACT, between RAA and distal CS), iii) left atrial activation time (LAAT, between atrial deflection in the distal His and distal CS), iv) bipolar electrogram duration at four atrial sites (RAA, His, proximal and distal CS). In the PAF group, measurements were also determined during handgrip and carotid sinus massage (CSM), and after pharmacological blockade of the ANS (ANSB). AF was induced by HRA programmed stimulation in 56% (self-limited - 6; sustained - 3), 68.8% (self-limited - 6; sustained - 5), and 50% (self-limited - 5; sustained - 3) of the P, in basal, during ANS maneuvers, and after ANSB, respectively (p=NS). IACT, interACT and LAAT significantly lengthened during HRA pacing in both groups (600ms, S2). P with PAF have longer IACT (p<0.05), a higher increase in both IACT, interACT (p<0.01) and electrograms duration (p<0.05) with S2, and more fragmented activity, compared with the control group. Atrial conduction times and electrograms duration were not significantly changed during ANS stimulation. Nevertheless, ANS maneuvers increased heterogeneity of the local electrograms duration. Also, P with sustained AF showed longer interACT and LAAT during CSM. CONCLUSION: Atrial conduction times, electrograms duration and fractionated activity are increased in PAF, suggesting a role for conduction delays in the arrhythmogenic substrate. Acute vagal stimulation is associated with prolonged interACT and LAAT in P with inducible sustained AF and ANS modulation may influence the heterogeneity of atrial electrograms duration.

Estado da Arte da Computação Evolutiva Aplicada à Eletrónica

A Computação Evolutiva enquadra-se na área da Inteligência Artificial e é um ramo das ciências da computação que tem vindo a ser aplicado na resolução de problemas em diversas áreas da Engenharia. Este trabalho apresenta o estado da arte da Computação Evolutiva, assim como algumas das suas aplicações no ramo da eletrónica, denominada Eletrónica Evolutiva (ou Hardware Evolutivo), enfatizando a síntese de circuitos digitais combinatórios. Em primeiro lugar apresenta-se a Inteligência Artificial, passando à Computação Evolutiva, nas suas principais vertentes: os Algoritmos Evolutivos baseados no processo da evolução das espécies de Charles Darwin e a Inteligência dos Enxames baseada no comportamento coletivo de alguns animais. No que diz respeito aos Algoritmos Evolutivos, descrevem-se as estratégias evolutivas, a programação genética, a programação evolutiva e com maior ênfase, os Algoritmos Genéticos. Em relação à Inteligência dos Enxames, descreve-se a otimização por colônia de formigas e a otimização por enxame de partículas. Em simultâneo realizou-se também um estudo da Eletrónica Evolutiva, explicando sucintamente algumas das áreas de aplicação, entre elas: a robótica, as FPGA, o roteamento de placas de circuito impresso, a síntese de circuitos digitais e analógicos, as telecomunicações e os controladores. A título de concretizar o estudo efetuado, apresenta-se um caso de estudo da aplicação dos algoritmos genéticos na síntese de circuitos digitais combinatórios, com base na análise e comparação de três referências de autores distintos. Com este estudo foi possível comparar, não só os resultados obtidos por cada um dos autores, mas também a forma como os algoritmos genéticos foram implementados, nomeadamente no que diz respeito aos parâmetros, operadores genéticos utilizados, função de avaliação, implementação em hardware e tipo de codificação do circuito.

Transgenerational Inheritance of Paternal Neurobehavioral Phenotypes: Stress, Addiction, Ageing and Metabolism

Epigenetic modulation is found to get involved in multiple neurobehavioral processes. It is believed that different types of environmental stimuli could alter the epigenome of the whole brain or related neural circuits, subsequently contributing to the long-lasting neural plasticity of certain behavioral phenotypes. While the maternal influence on the health of offsprings has been long recognized, recent findings highlight an alternative way for neurobehavioral phenotypes to be passed on to the next generation, i.e., through the male germ line. In this review, we focus specifically on the transgenerational modulation induced by environmental stress, drugs of abuse, and other physical or mental changes (e.g., ageing, metabolism, fear) in fathers, and recapitulate the underlying mechanisms potentially mediating the alterations in epigenome or gene expression of offsprings. Together, these findings suggest that the inheritance of phenotypic traits through male germ-line epigenome may represent the unique manner of adaptation during evolution. Hence, more attention should be paid to the paternal health, given its equivalently important role in affecting neurobehaviors of descendants.

Quantification and viability analyses of Pseudokirchneriella subcapitata algal cells using image-based cytometry

This work aims to evaluate the feasibility of using image-based cytometry (IBC) in the analysis of algal cell quantification and viability, using Pseudokirchneriella subcapitata as a cell model. Cell concentration was determined by IBC to be in a linear range between 1 × 105 and 8 × 106 cells mL−1. Algal viability was defined on the basis that the intact membrane of viable cells excludes the SYTOX Green (SG) probe. The disruption of membrane integrity represents irreversible damage and consequently results in cell death. Using IBC, we were able to successfully discriminate between live (SG-negative cells) and dead algal cells (heat-treated at 65 °C for 60 min; SG-positive cells). The observed viability of algal populations containing different proportions of killed cells was well correlated (R 2 = 0.994) with the theoretical viability. The validation of the use of this technology was carried out by exposing algal cells of P. subcapitata to a copper stress test for 96 h. IBC allowed us to follow the evolution of cell concentration and the viability of copper-exposed algal populations. This technology overcomes several main drawbacks usually associated with microscopy counting, such as labour-intensive experiments, tedious work and lack of the representativeness of the cell counting. In conclusion, IBC allowed a fast and automated determination of the total number of algal cells and allowed us to analyse viability. This technology can provide a useful tool for a wide variety of fields that utilise microalgae, such as the aquatic toxicology and biotechnology fields.

Influence of variables on centrifuge-flotation technique for recovery of Toxocara canis eggs from soil

The purpose of this study was to evaluate the influence of variables in a flotation technique for the recovery of Toxocara canis eggs from soil. The trials were done under standardized conditions on one gram of previously sterilized soil samples contaminated with 200 eggs of T. canis. The following variables were evaluated in serial steps: sieving; type of wash; time of stirring; resuspension of sediment; solution flotation. Centrifuge-flotation in sodium nitrate (d = 1.20 g/cm³) was adopted as an initial technique, using Tween 80 (0.2%) and decinormal sodium hydroxide as solutions for washing the samples. Ten tests were done to compare the variables, using counting in triplicate. The sieving of the material reduced significantly the recovery of eggs (p < 0.001) and the number of eggs recovered was higher when the sediment was resuspended (p < 0.05). After standardization, flotation solutions sodium chloride, zinc sulfate, sodium dichromate, magnesium sulfate, and sodium nitrate (d = 1.20g/cm³) were compared. The best results were obtained by using zinc sulfate solution. In conclusion, the chances of recovering T. canis eggs from samples using flotation solutions can be increased by washing of soil twice using distilled water, and resuspension of sediment. On the other hand, the sieving procedure can drastically reduce the number of eggs.

HOOKWORM AND THREADWORM INFECTIONS AND THEIR ASSOCIATION WITH HEMOGLOBIN AND EOSINOPHIL CONCENTRATIONS IN RESIDENTS OF SALVADOR-BAHIA, BRAZIL

SUMMARY Parasitic infections are responsible for substantial mortality and morbidity worldwide. In most healthy individuals, little overt pathology is observed during infection with S. stercoralis. However, the symptoms in advanced cases may include gastrointestinal bleeding. Anemia is most commonly associated with hookworm infection, especially when several hundred worms are present. Our study evaluates the relationship between the hookworm or S. stercoralis infection status and the hemoglobin concentration of individuals examined by a private network of laboratories in Salvador, Bahia, Brazil. We examined 374,120 samples from middle-class individuals living in Salvador City from January 2004 to April 2008. The stool samples were analyzed by the Lutz and Baermann-Moraes methods, and the blood samples were analyzed for hemoglobin concentration and eosinophil counting. The prevalence of hookworm and S. stercoralis were 0.27% (1,027) and 0.34% (1,286), respectively. The prevalence of hookworm and S. stercoralis infection was significantly higher in males than in females and increased with age. Eosinophilia was a common laboratorial finding in individuals infected with hookworm and S. stercoralis. The hemoglobin concentration was lower in the hookworm-infected individuals than in non-infected ones, but none of the examined patients were anemic. Lack of anemia could be a consequence of the socioeconomic status of these patients.

Estudo da qualidade de processos na fabricação de semicondutores

A indústria de semicondutores é um sector em permanente evolução tecnológica. A tendência de miniaturização e de otimização do espaço, a necessidade de produzir circuitos cada vez mais complexos, a tendência para o incremento do número de camadas em cada circuito integrado, são as condições necessárias para que a evolução tecnológica nesta área seja uma constante. Os processos ligados à produção de semicondutores estão também em permanente evolução, dada a pressão efetuada pelas necessidades acima expostas. Os equipamentos necessitam de uma crescente precisão, a qual tem que ser acompanhada de procedimentos rigorosos para que a qualidade atingida tenha sempre o patamar desejado. No entanto, a constante evolução nem sempre permite um adequado levantamento de todas as causas que estão na origem de alguns problemas detetados na fabricação de semicondutores. Este trabalho teve por objetivo efetuar um levantamento dos processos ligados ao fabrico de semicondutores a partir de uma pastilha de silício (wafer) previamente realizada, identificando para cada processo os possíveis defeitos introduzidos pelo mesmo, procurando inventariar as causas possíveis que possam estar na origem desse defeito e realizar procedimentos que permitam criar regras e procedimentos perfeitamente estabelecidos que permitam aprender com os erros e evitar que os mesmos problemas se possam vir a repetir em situações análogas em outros produtos de uma mesma família.

Design of switched-capacitor filters using low gain amplifiers

Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores