Control and readout electronics for miniaturized temperature sensors integrated with an organ-on-a-chip

Dissertação de mestrado em Engenharia Eletrónica Industrial e ComputadoresDe acordo com um estudo realizado pelo instituto de biomateriais e engenharia biomédica da Universidade de Toronto nos Estados Unidos da América, 4 em cada 1000 pacientes sofreram de efeitos adversos provocados por fármacos. Este problema surge devido ao facto de o teste de fármacos serem realizados em animais e, posteriormente em humanos. A utilização dos organ-on-a-chip aumentam a eficácia quando se inicia os testes em humanos porque são mais representiativos do que os testes em animais. A tecnologia organ-on-a-chip (OOC) surgiu com o objetivo de ser possível replicar aspetos importantes da fisiologia humana e deste modo poder superar as limitações dos procedimentos tradicionais, aumentando assim a segurança e eficácia de quem os toma. Apesar da tecnologia OOC fornecer uma série de vantagens comparativamente com as técnicas convencionais, esta ainda carece de sistemas para monitorização de multiparâmetros capazes de fornecer informações à microescala durante os testes de cultura de células bem como na testagem de novos fármacos. Neste sentido, torna-se muito importante o desenvolvimento de microssensores integrados em sistemas microfluídicos para monitorizar os diversos parâmetros celulares de modo a perceber que efeitos os fármacos provocam nas células. Parâmetros como temperatura, oxigénio, pH, nível de nutrientes, entre outros, são variáveis de interesse para a perceção global do metabolismo criado pela combinação de fármacos com células de múltiplos órgãos. Assim, o trabalho desenvolvido nesta dissertação tem como objetivo estudar e desenvolver a eletrónica de leitura e atuação de um microssensor de temperatura, baseado em resistance temperature detector (RTD), que será integrado na tecnologia OOC. O sistema desenvolvido para além de fornecer portabilidade e baixo custo, permite realizar leitura de vários microssensores com uma sensibilidade de 15mV/0.1°C. Foi também implementada uma componente gráfica que permite ao utilizador selecionar o sensor e acompanhar os resultados em tempo real.According to a study conducted by the Institute of Biomaterials and Biomedical Engineering at the University of Toronto in the United States of America, 4 out of every 1,000 patients suffered from drug-related adverse effects. This problem arises because the drug test mostly performed on animals and, therefore, does not faithfully question the phenomena that occur at the level of the human being. Thus, the use of these drugs can lead to complications for humans as well as damage to the pharmaceutical industry. Organ-on-a-chip (OOC) technology has emerged with the aim of replicating important aspects of human physiology and thus being able to overcome the limitations of traditional procedures, thereby increasing the safety and efficacy of those who take them. Although OOC technology provides several advantages compared to conventional techniques, it still lacks multiparameter monitoring systems capable of providing microscale information during cell culture testing as well as testing for new drugs. In this sense, it is very important to develop microsensors integrated in microfluidic systems to monitor the various cellular parameters in order to understand what effects the drugs have on cells. Parameters such as temperature, oxygen, pH, number of nutrients, among others, are variables of interest for the overall perception of metabolism created by the combination of drugs with multiple organ cells. Thus, the work developed this dissertation aims to study and develop the electronic reading and actuation of a micro temperature sensor, based on resistance temperature detector (RTD), which will be integrated into OOC technology. The system developed in addition to providing portability and low cost, allows to perform reading of several micro sensors with a sensitivity of 15mV/0.1°C. A graphical component has also been implemented that allows the user to select the sensor and track the results in real time.This work results partially of the project NORTE-01-0145-FEDER-029394, RTChip4Theranostics, supported by Programa Operacional Regional do Norte - Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and by Fundação para a Ciência e Tecnologia (FCT), IP, project reference PTDC/EMD-EMD/29394/2017

Ontological conversion: The place of self-knowledge, the contemplative tradition and contemporary mindfulness in education

In this paper, we will try to show how philosophy, psychology and education can still dwell on common issues, namely ontological transformation while using similar insights approaches. This is the case, for instance when we compare Epictetus’ spiritual exercises and the current contemplative knowledge stream to which Mindfulness is inserted. By essaying to look for the connection between the stated approaches perhaps we can bring forth some mutual enriching ideas in the mentioned fields

Multiscale streamflow forecasts for the Brazilian hydropower system using bayesian model averaging (BMA)

O uso de sistemas eficientes de previsão de afluências nas diversas escalas temporais permite otimizar a operação do conjunto de reservatórios hidrelétricos brasileiros, elevando o grau de segurança no fornecimento de energia elétrica e minimizando os custos operacionais. Entretanto, os modelos atuais de previsão utilizados pelo Operador Nacional do Sistema Elétrico (ONS) tendem a ser limitados no horizonte de previsão e na modelagem da dependência existente entre as diversas escalas de tempo, reduzindo a qualidade das previsões. Neste trabalho é proposta uma nova contribuição para os modelos de previsão de afluências em uso pelo ONS a partir do conceito de ponderação bayesiana de modelos (BMA), que permite integrar previsões mensais e semanais de vazões com objetivo de melhorar o desempenho das previsões semanais. As previsões mensais são obtidas por meio de um modelo periódico auto-regressivo exógeno (PARX), que busca captar a persistência das vazões na parte auto-regressiva e a contribuição do escoamento superficial na parcela exógena por meio do uso de informações climáticas de larga escala. Previsões semanais de afluência com até seis semanas de antecedência são obtidas a partir das informações disponibilizadas pelo ONS nos relatórios do Programa Mensal de Operação (PMO). A metodologia proposta é aplicada em séries de afluências semanais aos 28 principais reservatórios hidroelétricos brasileiros. Os resultados de previsão semanal de afluências obtidos com a ponderação das saídas dos modelos de previsão semanal e mensal indicam uma melhoria significativa em indicadores de desempenho de previsões (NS, MAPE e DM) quando comparados com os resultados de previsão oriundos do modelo semanal isolado. Os ganhos obtidos nos indicadores de desempenho são mais significativos a partir da segunda semana de antecedência. A abordagem proposta é flexível em termos de implementação, permitindo integrar outras escalas de previsão assim como diferentes modelos preditivos (por exemplo, modelos de base física).The use of efficient streamflow forecast systems at different time scales allows the operational optimization of the Brazilian interconnected hydropower reservoirs, raising the security level of electricity supply and minimizing operating costs. However, current forecasting models used by the National Electric System Operator (ONS) tend to be limited over the forecast horizon and in the modeling of the dependence structure across the various time scales, thus reducing the quality of forecasts. This paper proposes a new contribution to the streamflow forecast models by exploring the concept of Bayesian Model Averaging (BMA), which allows integrating weekly and monthly forecasts in order to improve the skill of weekly predictions. The monthly forecasts are obtained from a periodic auto-regressive exogenous model (PARX), which attempts to capture the persistence of flow in the auto-regressive part and the runoff contribution in the exogenous portion through the use of climate information. Weekly streamflow forecasts with up to six weeks lead time are obtained from information made available by ONS in the Monthly Operational Program (PMO) reports. The proposed methodology is tested using weekly inflow series from the 28 major Brazilian hydropower reservoirs. The weekly streamflow forecasts results obtained from the weighting of the outputs from the weekly and monthly models indicate a significant improvement in skill based on common performance indicators (NS, MAPE and DM) when compared with forecasts derived from the isolated weekly model. The gains in performance indicators are more significant for lead times beyond two weeks. The proposed approach is flexible in terms of implementation, allowing the incorporation of the other forecast scales as well as different forecast models (e.g. physical models)

USINAS DE BIODIESEL E FALHAS NO MERCADO DE LEILÕES

O trabalho tem por objetivo descrever e analisar as falhas de mercado no sistema de produção agroindustrial do biodiesel constituído por todos os participantes envolvidos na produção da matéria-prima agrícola, no processamento e na distribuição do produto. Incluem o suprimento dos produtores de matéria-prima, os produtores de matérias-primas, operações de estocagens, processamento, atacado e varejo. Incluem as instituições que afetam e coordenam os estágios sucessivos do fluxo do produto, tais como governo, associações e mercado de leilões. As relações contratuais são apontadas como importantes mecanismos de coordenação nos sistemas de mercadorias. No caso do sistema de produção do biodiesel brasileiro, o mecanismo de coordenação observado é o mercado de leilões, que estabelece a quase-integração mediante contratos entre as usinas e os distribuidores. O mercado de leilões de biodiesel é o mercado em que os produtos das usinas são vendidos e comprados por meio de processos formais de licitação. Esse mecanismo de coordenação tem apresentado as mesmas características dos mercados com problemas de informações assimétricas. Nessa situação, o comprador e o vendedor possuem informações diferentes sobre uma transação. Tendo como conseqüência a ineficiência de mercado. Uma forma de falha de mercado decorrente de informações assimétricas observado no mercado de leilões de biodiesel tem sido a seleção adversa e o risco moral. Isto significa que contratos que foram firmados com usinas de biodiesel que participaram de processos de licitações não estão sendo honrados de forma generalizada.--------------------------------------------------The present study aims at describing and analyzing the biodiesel agroindustrial productive chain built up with all components involved in the production, processing and the good marketing. It includes the supplying of the raw-material producers, stocking operations, processing system, the whole and retail market of the product. Institutions that affect and coordinate the successive stages of the product flow such as government, associations and the auctions market are also included. Contractual relations are referred to important coordination structures in the commodity system. In the particular case of the Brazilian biodiesel, the structure of coordination that is observed is the auctions market. Auctions are that marketplace in which the products are bought and sold through formal processes of licitation. Such mechanism presents the same characteristics of the markets with unequal information. In such situation, the buyer and the seller have different information about a transaction; as a result, there is a deviation in the market efficiency level. A kind of a market failure which results from unequal information seen in the auctions market has been the adverse selection. It means that contracts had been signed with biodiesel plants which took part in the licitation processes are not being fulfilled.Biodiesel, cadeia produtiva, mecanismo de coordenação e falhas de mercado, Biodiesel, productive chain, coordination structure and market failures, Agribusiness, Resource /Energy Economics and Policy,

Interaction Network and Niche Analysis of Natural Enemy Communities and their Host Bees (Hymenoptera: Apoidea) in fragments of Cerrado and Atlantic Forest

Natural enemies are important components of solitary bee communities that nest in preexisting cavities because they act as a relevant mortality factor and can regulate population growth. Despite this, the natural enemy-host interaction remains poorly investigated. This research aimed to determine the composition of the community, the structure of the interaction network, and niche overlap and breadth of natural enemy species in areas of Cerrado (Brazilian savanna) and Semideciduous seasonal forest (Atlantic Forest) in the state of São Paulo, Brazil. Trap-nests made of black cardboard and bamboo canes were provided in the field and inspected monthly in each area, from August 2001 to July 2003 at Cerrado and from June 2006 to May 2008 at the Semideciduous seasonal forest.  A modular structure in the interaction network was observed for both areas with the populations of natural enemies showing high degrees of specialization. This structure confers higher stability against disturbances than less specialized webs since these adversities must spread more slowly through the network. The niche analysis showed low degrees of overlap for both, trophic and temporal, among the natural enemy populations

A cidade capitalista e o progresso gentrificador: o processo de remodelação do Anhangabaú (1877-1917)

O artigo visa discutir de que maneira os processos de urbanização em curso na São Paulo da virada do séc. XIX - XX podem ter sido utilizados para engendrar discursos “gentrificadores” sobre regiões centrais específicas da cidade – pobres, encortiçadas, de meretrício e comércio simples. Nessas regiões, que constituíam um campo imobiliário fértil para a expansão e remodelação da cidade, existia uma preocupação moralizante da elite (principalmente no que tange a questão do meretrício) e um projeto de cidade espacialmente incompatível com as camadas baixas. Dentro desse espectro, elege-se como foco o processo de remodelação do Anhangabaú, iniciado com o anúncio do projeto de construção do primeiro Viaduto do Chá (1877) até a finalização das obras do Parque Anhangabaú (1917)

Perspectives on The Teaching Career Beginning in Basic Education: A Case Study

This article presents an analysis of the teaching career beginning in Basic Education using the beginning teacher as a reference. The study is based on the theoretical discussions of Gonçalves (2000), Huberman (2000), Guarnieri (2005), Tardif (2008), Darling-Hammond (2014), among others. For methodological development, we used qualitative research (BRASILEIRO, 2013), type case study (MEKSENAS, 2011) with input in ethnomethodology (COULON, 1995). The research was carried out in a public school and had as participants a teacher whose teaching time is less than two years, a principal and a pedagogical coordinator. The data collection techniques were observation, questionnaire, interview and field diary. Data analysis was performed based on Bardin (1977), and interpretation in accordance with Hermeneutics-Dialectics also discussed through Minayo\u27s reflections (1998). The results indicate elements that facilitate the beginning of the teaching profession, such as commitment, respect, profile, self-confidence, among other principles. They also point out difficult elements, such as shyness and practical fragility. They also show the different challenges encountered by the teacher, especially the process of overcoming the dichotomy between training (theory) and professional practice. In general, the research findings show that the entry of the beginner teacher into the school results from a university education based on teaching and research. And, that the beginning of the teaching career explains a context of learning knowledge, characterized by the availability and proactivity inherent in pedagogical work, by the experiences of social relations between students and school professionals that converge to the construction of the teaching professional identity. Therefore, the study expands the reflection on the teaching profession from the perspective of the beginning teacher collaborating to expand this field of knowledge

On Separating Environmental and Speaker Adaptation

This paper presents a maximum likelihood (ML) approach, concerned to the background model estimation, in noisy acoustic non-stationary environments. The external noise source is characterised by a time constant convolutional and a time varying additive components. The HMM composition technique, provides a mechanism for integrating parametric models of acoustic background with the signal model, so that noise compensation is tightly coupled with the background model estimation. However, the existing continuous adaptation algorithms usually do not take advantage of this approach, being essentially based on the MLLR algorithm. Consequently, a model for environmental mismatch is not available and, even under constrained conditions a significant number of model parameters have to be updated. From a theoretical point of view only the noise model parameters need to be updated, being the clean speech ones unchanged by the environment. So, it can be advantageous to have a model for environmental mismatch. Additionally separating the additive and convolutional components means a separation between the environmental mismatch and speaker mismatch when the channel does not change for long periods. This approach was followed in the development of the algorithm proposed in this paper. One drawback sometimes attributed to the continuous adaptation approach is that recognition failures originate poor background estimates. This paper also proposes a MAP-like method to deal with this situation

DOSSIÊ: RELIGIÃO E POLÍTICA

Apresentação do v. 5, n. 9, jan./jun. 2014, Dossiê Religião e Política