Proposta de um modelo gráfico e navegacional básico para interfaces de aplicações educacionais baseado em validação experimental

O desenvolvimento de projetos de interfaces gráficas está apoiado em guias de recomendações. Estes guias apresentam regras genéricas aos projetos de Interfaces Homem Computador–IHC. Entretanto, aplicações particulares, como as educacionais, não encontram regras específicas que atendam as necessidades do usuário-alvo. Ainda, a análise comparativa entre guias disponíveis aponta contradições entre as recomendações genéricas com aquelas específicas aplicadas a um determinado ambiente. A necessidade de um modelo de referência para a construção de interfaces gráficas amigáveis ao usuário e a escassez e contradições de recomendações específicas às aplicações educacionais motivaram o trabalho de pesquisa prática junto aos usuáriosalvo. Para a identificação das recomendações sobre aspectos gráficos básicos e elementos de navegação necessários a uma efetiva interação com interfaces dedicadas a aplicações educacionais, foi desenvolvido um instrumento de pesquisa que permitiu a investigação das preferências relativas aos aspectos pesquisados junto ao público-alvo. Os dados coletados foram tratados estatisticamente e os resultados obtidos contrariam tanto critérios adotados em interfaces de sistemas de ensino disponíveis na Internet como algumas recomendações sobre os mesmos disponíveis na literatura. Os resultados obtidos apontam, também, para a preferência dos usuários por elementos de navegação que não são referidos nos guias de recomendações consultados. A análise dos resultados possibilitou a geração de um modelo básico que recomenda preferências sobre aspectos gráficos básicos, como aplicação de cores em fontes e fundos de tela, tipologia de fontes para textos e paginação, e também, sobre componentes de navegação, como posicionamento e preferência por tipo de recurso de navegação. O modelo proposto está fundamentado nas recomendações de Nielsen [NIE 00], o qual recomenda que as necessidades dos usuários na interatividade com a interface sejam identificadas junto a estes usuários. As recomendações apresentadas neste trabalho foram utilizadas, inicialmente, nos ambientes educacionais desenvolvidos dentro dos projetos Tapejara [TAP 00] e LaVia [LAV 00].

Informational synergies in consumer credit

Lenders can tap into multiple sources of private information to assess consumer credit risk but little is known about the informational synergies between these sources. Using unique panel data on checking accounts and credit card accounts from the same customers during 2007-2014, we find that activity measures from both account types contain information beyond credit scores and other controls. Checking accounts display warning indications earlier and more accurately than credit card accounts. We also investigate the consistency of information, the reasons for defaults, and selection effects. The evidence highlights sizeable informational synergies that lenders can use to manage credit relationships.

Pode um grupo de teatro escolar ser uma comunidade de prática, conducente a inovação pedagógica?

O presente estudo, no âmbito do Mestrado em Ciências de Educação – Inovação Pedagógica tem como objetivo analisar o modo como uma comunidade (principal objeto de estudo), constituida por um grupo de teatro escolar, neste caso concreto “O Moniz”, constrói aprendizagens significativas, decorrentes de práticas sócioconstrutivistas, relembrando os princípios básicos sobre a influência e importância do teatro junto das comunidades educativas. O termo comunidade de prática, referida por Jeane Lave e Ettiene Wenger, que consideram a aprendizagem como um fenómeno situado, é utilizado para análise e discussão das aprendizagens emergentes desses alunos que, através de atividades práticas e metodologias informais, de trabalho colaborativo e cooperativo, entre eles, poderão favorecer e potenciar as diferentes dimensões humanas, sobretudo numa educação socializadora, para além das dimensões dos valores e da afetividade que ficam muitas vezes fora do currículo, sendo importantes para a formação integral das pessoas e indispensáveis para uma vida feliz. Este estudo de caso tem em vista utilizar uma metodologia qualitativa, usando técnicas de cariz etnográfico, no ambiente natural dos sujeitos, com o intuito de relevar e confrontar subjetividades, atendendo às percepções de cada participante. Concluimos que este grupo de teatro reúne os principais elementos de uma Comunidade de Prática (Domínio, Comunidade e Prática), designados por Wenger (1991). Além disso, são visíveis caraterísticas que permitem relacioná-lo com as CdP, tais como: o compromisso mútuo, o empreendimento múto e o reportório partilhado.

Technologies that motivates healthy toothbrushing: practices through social translucence

Fifty percent of the European Union’s population suffers from an oral disease. Studies have repeatedly shown that while acquiring healthy toothbrushing practices early on in one’s life is of significance, children and adults often fail to adhere to those. In this thesis we attempt to design and prototype interactive technologies that motivate healthy tooth brushing habits on individuals. Rather than focusing on the technologies’ persuasive power over individuals, we tap on the social mechanisms employed by families. In this sense, we think of these technologies as social translucent rather than persuasive, whose goal is to raise awareness within the family on each other’s habits and that aim at leveraging families’ existing social mechanisms for behavior change, rather than replacing them. More specifically, we aim to gain insights with respect to the following questions: a) What are the drivers and barriers towards adhering to healthy tooth brushing behaviors? b) Can we effectively measure toothbrushing behaviors? c) How can technologies leverage family communication practices in motivating proper toothbrushing behaviors? First, we present two studies about children and adults’ tooth brushing behaviors and how these are influenced by social interactions within the family. Secondly, we present the design and prototyping of two systems that sense toothbrushing practices and provide feedback, using the Social Translucence Framework as a design lens. We conclude with an overview of lessons learnt from the prototyping of these systems supported by an analysis of the strengths and pitfalls of the developed technologies.

Estudo clínico-laboratorial e histopatológico de cães naturalmente infectados por Leishmania chagasi com diferentes graus de manifestação física

Canine Visceral Leishmania (CVL) is an important zoonotic disease that has a world wide distribution and has a large impact on public health on the American Continent, especially in Brazil, where the nature of endemic diseases in humans affects a large part of the nation. The influence of the prevalence of CVL in the increased rate of human cases in endemic areas and in the unleashing of epidemic outbreaks shows the need for a more profound understanding, that would generate significant advances in the current measures used to control the reservoirs of sickness that are practiced by the Programa Nacional de Vigilância e Controle da Leishmaniose Visceral. The present work describes and compares the clinical-laboratorial and histopathological findings of twenty-three dogs that were naturally infected by Leishmania chagasi, from endemic areas in metropolitan Natal, Rio Grande do Norte, Brazil. These animals, that were selected and given physical and serological exams (IFI and ELISA rK-39), were classified according to the degree of clinical severity and had blood samples drawn (whole blood and serum) for a complete hemogram and a coagulogram to be done as well as biochemical tests for kidney and liver function. The confirmation of infection by L. chagasi was done after the euthanasia of the animals, through the direct demonstration of the parasite in the impression of the spleen and liver crowned with GIEMSA and through a cultivation by means of NNN/Schneider. According to the clinical evaluation, the animals were classified as asymptomatic (7), oligosymptomatic (7) and polysymptomatic (9). Among the animals that were chosen to be autopsied, there were 2 asymptomatic, 3 oligosymptomatic and 3 polysymptomatic, for the purpose of studying their histopathology, having collected fragments of the spleen, liver, kidneys and skin and were fixed in 10% tamponed formol. The comparison between the average parameters of the clinical-laboratory tested animals in the groups was done through the Student t test (a<0.05). The main clinical signals observed were lymphadenomegaly, alopecy, dermatitis, exfoliation, cutaneous ulcers, onicogriphosis and emaciation. The main clinical-laboratorial alterations established, mainly in the polysymptomatic group, were anemia, hyperproteinemia, hyperglobulinemia, alterations in the albumin/globulin ratio and increased ALT activity. Renal alterations were not verified (urea and creatinine levels were normal). Thrombocytopenia was observed in three clinical groups. However, the other indicators of coagulation function (TAP and TTPA) did not have abnormal variations. There were inflammatory infiltrations and leishmania amastigotes in the skin of polysymptomatic dogs, however, they were not found in the skin of asymptomatic animals. Hypertrophy and hyperplasia of the phagocyte mononuclear system, leishmania amastigote parasites were found in the macrophages, extramedullary hematopoiesis and degenerative alterations were detected in the spleen and liver of 8 of the animals submitted to histopathological exams. In accord with these results, it was demonstrated that the expected alterations in the hematological and biochemical parameters in function of their viscerotropic nature of CVL are mainly observed in the more advanced stages of the disease. The absence of inflammatory infiltration and parasite load in the skin suggest that infected animals without symptoms may have an importance irrelevant to the infectiousness of the vector

Aproveitamento de resíduos minerais na formulação de argamassas para a construção civil

Current environmental concerns include the excessive consumption and inefficient use of non-renewable natural resources. The construction industry is considered one of the largest consumers of natural raw materials, significantly contributing to the environmental degradation of the planet. The use of calcareous quarry (RPPC) and porcelain tile polishing residues (RPP) as partial replacements of the cement in mortars is an interesting alternative to minimize the exploration of considerably large amounts of natural resources. The present study aimed at investigating the properties of fresh and hardened mortars produced using residues to replace cement. The residues used were fully characterized to determine their specific mass, unitary mass, particle size distribution and morphology, and composition. The performance of the mortars was compared to that of reference compositions, prepared without residues. A total of 18 compositions were prepared, 16 using residues and 2 reference ones. The mortars were prepared using Portland CP II F 32 cement, CH I hydrated lime, river sand and tap water. The compositions of the mortars were 1:1:6 and 1:0.5:4.5 (vol%), and water to cement ratios of 1.87 and 1.45 were used, respectively. The mortars in the fresh state were evaluated by consistency index, water retention, density of mass and incorporated air content tests. In their hardened state, the mortars were evaluated by apparent mass density, modulus of elasticity, flexural tensile strength, compressive strength and water absorption by capillarity. The mortars were also analyzed by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and fluorescence. Finally, they were classified according to NBR 13281 standards. The mortars prepared using residues partially replacing the cement exhibited lower modulus of elasticity compared to the reference compositions, thus improving the performance in their intended use. On the downside, the water absorption by capillarity was affected by the presence of residues and both the tensile and compressive strength were reduced. However, from the overall standpoint, the replacement of cement by calcareous quarry or porcelain tile polishing residues did not result in significant changes in the properties of the mortars. Therefore, compositions containing these residues can be used in the construction industry

Qualidade fisiológica de sementes de Psidium cattleianum sabine acondicionadas e armazenadas em diferentes condições

Sementes de Psidium cattleianum foram acondicionadas em embalagens permeável, semipermeável e impermeável e armazenadas em ambiente não controlado, câmara seca e câmara fria por 1.107 dias, com o objetivo de avaliar a qualidade fisiológica. Desde o início do armazenamento das sementes, e após cada período de 123 dias, foram avaliados o teor de água, a porcentagem e o índice de velocidade de germinação e a condutividade elétrica da solução de embebição. Nos testes de germinação e de condutividade elétrica, as sementes foram previamente imersas em ácido sulfúrico durante 25 minutos, depois lavadas em água corrente e em água destilada. As sementes foram colocadas para germinar, entre vermiculita, na temperatura alternada de 20-30 ºC, sob lâmpadas fluorescentes brancas, com fotoperíodo de 8 horas. O acondicionamento das sementes em embalagem impermeável e o armazenamento em ambiente natural de laboratório ou em câmara seca, bem como o acondicionamento em embalagem semipermeável e armazenamento em câmara fria, são adequados para a conservação das sementes durante 1.107 dias.

Otimização do fresamento de roscas internas com a técnica de interpolação helicoidal

In machining of internal threads, dedicated tools, known as taps, are needed for each profile type, diameter, and low cutting speed values are used when compared to main machining processes. This restriction in the cutting speed is associated with the difficulty of synchronizing the tool s rotation speed and feed velocity in the process. This fact restricts the flexibility and makes machining lead times longer when manufacturing of components with threads is required. An alternative to the constraints imposed by the tap is the thread milling with helical interpolation technique. The technique is the fusion of two movements: rotation and helical interpolation. The tools may have different configurations: a single edge or multiple edges (axial, radial or both). However, thread milling with helical interpolation technique is relatively new and there are limited studies on the subject, a fact which promotes challenges to its wide application in the manufacturing shop floor. The objective of this research is determine the performance of different types of tools in the thread milling with helical interpolation technique using hardened steel workpieces. In this sense, four tool configurations were used for threading milling in AISI 4340 quenched and tempered steel (40 HRC). The results showed that climb cut promoted a greater number of machined threads, regardless of tool configuration. The upcut milling causes chippings in cutting edge, while the climb cutting promotes abrasive wear. Another important point is that increase in hole diameter by tool diameter ratio increases tool lifetime

Exploiting Distinct Molecular Architectures of Ultrathin Films Made with Iron Phthalocyanine for Sensing

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Occurrence of fungi in water used at a haemodialysis centre

Aims: The aim of this study was to identify and determine the diversity, occurrence and distribution of fungi in water used at a haemodialysis centre.Methods and Results: Samples in the hydraulic circuit for the distribution of the water, dialysate samples and samples of sterilization solution from dialysers were collected over a 3-month period, and 500 ml of each sample was filtered through membranes. All together 116 isolates of fungi were recovered from 89% of all water samples collected inside the haemodialysis unit, with prevalence of moulds in tap water samples and of yeasts in dialysate samples. Fusarium spp. was the most abundant genus found, whereas Candida parapsilosis was the predominant yeast species.Conclusions: This study demonstrated that various fungi were present in the water system. These data suggest the inclusion of the detection and quantification of fungi in the water of haemodialysis.Significance and Impact of the Study: The recovery of fungi from aqueous haemodialysis environments implies a potential risk for haemodialysis patients and indicates the need for continuous maintenance and monitoring. Further studies on fungi in haemodialysis water systems are required to investigate the organism ability to persist, their role in biofilm formation and their clinical significance.

MICROBIOLOGICAL CONTAMINATION of A HEMODIALYSIS CENTER WATER DISTRIBUTION SYSTEM

The microbiological monitoring of the water used for hemodialysis is extremely important, especially because of the debilitated immune system of patients suffering from chronic renal insufficiency. To investigate the occurrence and species diversity of bacteria in waters, water samples were collected monthly from a hemodialysis center in upstate São Paulo and tap water samples at the terminal sites of the distribution system was sampled repeatedly (22 times) at each of five points in the distribution system; a further 36 samples were taken from cannulae in 19 hemodialysis machines that were ready for the next patient, four samples from the reuse system and 13 from the water storage system. To identify bacteria, samples were filtered through 0.22 mu m-pore membranes; for mycobacteria, 0.45 mu m pores were used. Conventional microbiological and molecular methods were used in the analysis. Bacteria were isolated from the distribution system (128 isolates), kidney machine water (43) and reuse system (3). Among these isolates, 32 were Gram-positive rods, 120 Gram-negative rods, 20 Gram-positive cocci and 11 mycobacteria. We propose the continual monitoring of the water supplies in hemodialysis centers and the adoption of effective prophylactic measures that minimize the exposure of these immunodeficient patients to contaminated sources of water.

Xylan from corn cobs, a promising polymer for drug delivery: Production and characterization

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A modified Primal-Dual Logarithmic-Barrier Method for solving the Optimal Power Flow problem with discrete and continuous control variables

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Parameterized fast decoupled power flow methods for obtaining the maximum loading point of power systems. Part I. Mathematical modeling

The conventional Newton and fast decoupled power flow (FDPF) methods have been considered inadequate to obtain the maximum loading point of power systems due to ill-conditioning problems at and near this critical point. It is well known that the PV and Q-theta decoupling assumptions of the fast decoupled power flow formulation no longer hold in the vicinity of the critical point. Moreover, the Jacobian matrix of the Newton method becomes singular at this point. However, the maximum loading point can be efficiently computed through parameterization techniques of continuation methods. In this paper it is shown that by using either theta or V as a parameter, the new fast decoupled power flow versions (XB and BX) become adequate for the computation of the maximum loading point only with a few small modifications. The possible use of reactive power injection in a selected PV bus (Q(PV)) as continuation parameter (mu) for the computation of the maximum loading point is also shown. A trivial secant predictor, the modified zero-order polynomial which uses the current solution and a fixed increment in the parameter (V, theta, or mu) as an estimate for the next solution, is used in predictor step. These new versions are compared to each other with the purpose of pointing out their features, as well as the influence of reactive power and transformer tap limits. The results obtained with the new approach for the IEEE test systems (14, 30, 57 and 118 buses) are presented and discussed in the companion paper. The results show that the characteristics of the conventional method are enhanced and the region of convergence around the singular solution is enlarged. In addition, it is shown that parameters can be switched during the tracing process in order to efficiently determine all the PV curve points with few iterations. (C) 2003 Elsevier B.V. All rights reserved.

Parameterized fast decoupled power flow methods for obtaining the maximum loading point of power systems. Part II. Performance evaluation

The parameterized fast decoupled power flow (PFDPF), versions XB and BX, using either theta or V as a parameter have been proposed by the authors in Part I of this paper. The use of reactive power injection of a selected PVbus (Q(PV)) as the continuation parameter for the computation of the maximum loading point (MLP) was also investigated. In this paper, the proposed versions obtained only with small modifications of the conventional one are used for the computation of the MLP of IEEE test systems (14, 30, 57 and 118 buses). These new versions are compared to each other with the purpose of pointing out their features, as well as the influence of reactive power and transformer tap limits. The results obtained with the new approaches are presented and discussed. The results show that the characteristics of the conventional FDPF method are enhanced and the region of convergence around the singular solution is enlarged. In addition, it is shown that these versions can be switched during the tracing process in order to efficiently determine all the PV curve points with few iterations. A trivial secant predictor, the modified zero-order polynomial, which uses the current solution and a fixed increment in the parameter (V, theta, or mu) as an estimate for the next solution, is used for the predictor step. (C) 2003 Elsevier B.V. All rights reserved.