Label-free detection of biomolecules with Ta2O5-based field effect devices

Dissertação para obtenção do Grau de Doutor em Nanotecnologias e Nanociências

Pro poor tourism for community development on Atauro Island, Timor-Leste

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

A CSR communication strategy for Continente: Improving brand image and reinforcing local community bonds

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Time series morphological analysis applied to biomedical signals events detection

Dissertation submitted in the fufillment of the requirements for the Degree of Master in Biomedical Engineering

The impact of online brand community on electronic word-of-mouth communications

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Gold nanoprobes for the detection of mutations associated with antibiotic resistance in Mycobacterium tuberculosis complex

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

The impact of Ireland’s current Mental Health Policy on the profile of community mental Health Services

RESUMO: Em 2006, foi aprovada uma nova política governamental para a saúde mental intitulada “Uma Visão para a Mudança”, a qual está neste momento no sétimo ano de implementação. A política descreve um enquadramento para o desenvolvimento e promoção da saúde mental positiva para toda a Comunidade e para a prestação de serviços acessíveis, baseados na comunidade, serviços especializados para pessoas com doença mental. A implementação da política e o tornar a “Vision for Change” uma realidade têm sido problemáticos, com críticas consideráveis por parte dos intervenientes, relativas à lenta e desconexa implementação. Este estudo fornece informação sobre as características dos serviços de três importantes tipos de instituições de saúde mental comunitária a nível nacional, nomeadamente Hospitais de Dia, Centros de Dia e residências comunitárias operantes 24 horas. A pesquisa analisa objetivos e funções, perfis dos pacientes, atividades terapêuticas, a eficácia das redes de comunicação e beneficia da perspectiva dos funcionários sobre o que mudou no terreno ao longo dos últimos sete anos. As questões identificadas a partir das características dos três serviços dizem respeito a todos. Os participantes indicaram que o ethos da recuperação parece ter alcançado um papel mais central no tratamento do paciente na comunidade mas reconheceram que o desafio de integrar os princípios de recuperação na prática clínica se mantém presente. Parece ser reconhecida a importância da planificação do cuidado individual nos serviços comunitários e os entrevistados indicaram que existe um empenho para garantir o envolvimento do usuário do serviço. Há diferenças entre os „pontos de vista do pessoal‟ e os „pontos de vista dos representantes‟ sobre uma série de aspetos da prestação de serviços. Este é o primeiro estudo irlandês deste género a examinar a prestação de serviços das três principais instituições comunitárias de saúde mental num só estudo. Estes serviços representam um enorme investimento em recursos, quer a nível monetário, quer humano. O estudo examinou os desafios e as questões fundamentais que lhe são aplicáveis e que têm impacto nestes três tipos de prestação de serviços. Também forneceu informações sobre os elementos de mudança positiva, os quais se começam a focar lentamente na prestação do serviço, assim como na importância da centralidade do utilizador do serviço e na promoção de um ethos da recuperação.----------ABSTRACT: In 2006, a new Government policy for mental health “A Vision for Change” was endorsed and is currently in the seventh year of implementation. The policy describes a comprehensive framework for building and fostering positive mental health across the entire community and for providing accessible, community based, specialist services for people with mental illness. The implementation of the policy and turning “Vision for Change” into reality has been problematic with considerable criticism from stakeholders concerning slow and disjointed implementation. This study provides information on three key community mental health service settings, namely Day Hospitals, Day Centres and 24 Hour Community Residences at a national level. The research looks at aims and functions, patient profiles, therapeutic activities, effectiveness of key communication networks and gains an insight from staff on what has changed on the ground over the past seven years. Issues identified from the three service settings pertain to all. Participants indicated that the recovery ethos appears to have moved to a more central role in patient care in the community but acknowledged that the challenge of integrating recovery principles in clinical practice remains present. The importance of individual care planning appears to be recognised in community services and respondents indicated that efforts are being made to ensure service user involvement. There were differences between „staff views‟ and „advocate views‟ on a number of aspects of service provision. This is the first Irish study of its kind to examine service provision across the three main community mental health settings in one study. These services represent a huge investment in resources both on a monetary and human level. This study has examined the challenges and key issues which are applicable and impacting on all three types of service provision. It has also provided information on the elements of positive change, which are slowly embedding themselves in service provision such as the importance of the centricity of the service user and the promotion of a recovery ethos.

Studies on the wine spoilage yeast Brettanomyces bruxellensis: 4-ethylphenol production and improved detection

Dissertação para obtenção do Grau de Mestre em Biotecnologia

A low-voltage RF-CMOS receiver front-end for a wireless fall detection microsystem

Dissertação para obtenção do Grau de Mestre em Engenharia Eletrotécnica e de Computadores, pela Universidade Nova de Ciências e Tecnologia

A nanopore-based stochastic detection method: Single molecule characterisation of nanoparticles using ()- hemolysin

Dissertation presented to obtain the Ph.D degree in Chemistry.

A volumetric hybrid representation for obstacle detection in all-terrain robots

This dissertation presents an approach aimed at three-dimensional perception’s obstacle detection on all-terrain robots. Given the huge amount of acquired information, the adversities such environments present to an autonomous system and the swiftness, thus required, from each of its navigation decisions, it becomes imperative that the 3-D perceptional system to be able to map obstacles and passageways in the most swift and detailed manner. In this document, a hybrid approach is presented bringing the best of several methods together, combining the lightness of lesser meticulous analyses with the detail brought by more thorough ones. Realizing the former, a terrain’s slope mapping system upon a low resolute volumetric representation of the surrounding occupancy. For the latter’s detailed evaluation, two novel metrics were conceived to discriminate the little depth discrepancies found in between range scanner’s beam distance measurements. The hybrid solution resulting from the conjunction of these two representations provides a reliable answer to traversability mapping and a robust discrimination of penetrable vegetation from that constituting real obstructions. Two distinct robotic platforms offered the possibility to test the hybrid approach on very different applications: a boat, under an European project, the ECHORD Riverwatch, and a terrestrial four-wheeled robot for a national project, the Introsys Robot.

A semi-automatic approach to code smells detection

Eradication of code smells is often pointed out as a way to improve readability, extensibility and design in existing software. However, code smell detection remains time consuming and error-prone, partly due to the inherent subjectivity of the detection processes presently available. In view of mitigating the subjectivity problem, this dissertation presents a tool that automates a technique for the detection and assessment of code smells in Java source code, developed as an Eclipse plugin. The technique is based upon a Binary Logistic Regression model that uses complexity metrics as independent variables and is calibrated by expert‟s knowledge. An overview of the technique is provided, the tool is described and validated by an example case study.

Transimpedance amplifier for early detection of breast cancer

Breast cancer is the most common type of cancer worldwide. The effectiveness of its treatment depends on early stage detection, as well as on the accuracy of its diagnosis. Recently, diagnosis techniques have been submitted to relevant breakthroughs with the upcoming of Magnetic Resonance Imaging, Ultrasound Sonograms and Positron Emission Tomography (PET) scans, among others. The work presented here is focused on studying the application of a PET system to a Positron Emission Mammography (PEM) system. A PET/PEM system works under the principle that a scintillating crystal will detect a gamma-ray pulse, originated at the cancerous cells, converting it into a correspondent visible light pulse. The latter must then be converted into an electrical current pulse by means of a Photo- -Sensitive Device (PSD). After the PSD there must be a Transimpedance Amplifier (TIA) in order to convert the current pulse into a suitable output voltage, in a time period lower than 40 ns. In this Thesis, the PSD considered is a Silicon Photo-Multiplier (SiPM). The usage of this recently developed type of PSD is impracticable with the conventional TIA topologies, as it will be proven. Therefore, the usage of the Regulated Common-Gate (RCG) topology will be studied in the design of the amplifier. There will be also presented two RCG variations, comprising a noise response improvement and differential operation of the circuit. The mentioned topology will also be tested in a Radio-Frequency front-end, showing the versatility of the RCG. A study comprising a low-voltage self-biasing feedback TIA will also be shown. The proposed circuits will be simulated with standard CMOS technology (UMC 130 nm), using a 1.2 V power supply. A power consumption of 0.34 mW with a signal-to-noise ratio of 43 dB was achieved.

Amorphous silicon e 3D sensors applied to object detection

Nowadays, existing 3D scanning cameras and microscopes in the market use digital or discrete sensors, such as CCDs or CMOS for object detection applications. However, these combined systems are not fast enough for some application scenarios since they require large data processing resources and can be cumbersome. Thereby, there is a clear interest in exploring the possibilities and performances of analogue sensors such as arrays of position sensitive detectors with the final goal of integrating them in 3D scanning cameras or microscopes for object detection purposes. The work performed in this thesis deals with the implementation of prototype systems in order to explore the application of object detection using amorphous silicon position sensors of 32 and 128 lines which were produced in the clean room at CENIMAT-CEMOP. During the first phase of this work, the fabrication and the study of the static and dynamic specifications of the sensors as well as their conditioning in relation to the existing scientific and technological knowledge became a starting point. Subsequently, relevant data acquisition and suitable signal processing electronics were assembled. Various prototypes were developed for the 32 and 128 array PSD sensors. Appropriate optical solutions were integrated to work together with the constructed prototypes, allowing the required experiments to be carried out and allowing the achievement of the results presented in this thesis. All control, data acquisition and 3D rendering platform software was implemented for the existing systems. All these components were combined together to form several integrated systems for the 32 and 128 line PSD 3D sensors. The performance of the 32 PSD array sensor and system was evaluated for machine vision applications such as for example 3D object rendering as well as for microscopy applications such as for example micro object movement detection. Trials were also performed involving the 128 array PSD sensor systems. Sensor channel non-linearities of approximately 4 to 7% were obtained. Overall results obtained show the possibility of using a linear array of 32/128 1D line sensors based on the amorphous silicon technology to render 3D profiles of objects. The system and setup presented allows 3D rendering at high speeds and at high frame rates. The minimum detail or gap that can be detected by the sensor system is approximately 350 μm when using this current setup. It is also possible to render an object in 3D within a scanning angle range of 15º to 85º and identify its real height as a function of the scanning angle and the image displacement distance on the sensor. Simple and not so simple objects, such as a rubber and a plastic fork, can be rendered in 3D properly and accurately also at high resolution, using this sensor and system platform. The nip structure sensor system can detect primary and even derived colors of objects by a proper adjustment of the integration time of the system and by combining white, red, green and blue (RGB) light sources. A mean colorimetric error of 25.7 was obtained. It is also possible to detect the movement of micrometer objects using the 32 PSD sensor system. This kind of setup offers the possibility to detect if a micro object is moving, what are its dimensions and what is its position in two dimensions, even at high speeds. Results show a non-linearity of about 3% and a spatial resolution of < 2µm.

Enrichment of a PHA producing microbial community in a continuous bioreactor setup

Polyhydroxyalkanoates (PHAs) are biosynthetic polyesters, biodegradable and biocompatible making them of great interest for industrial purposes. The use of low value substrates with mixed microbial communities (MMC) is a strategy currently used to decrease the elevated PHA production costs. PHA production process requires an important step for selection and enrichment of PHA-storing microorganisms which is usually carried out in a Sequencing Batch Reactor (SBR). The aim of this study was to optimize the PHA accumulating culture selection stage using a 2-stage Continuous Stirrer Tank Reactor (CSTR) system. The system was composed by two separate feast and famine bioreactors operated continuously, mimicking the feast and famine phases in a SBR system. Acetate was used as carbon source and biomass seed was highly enriched in Plasticicumulans acidivorans obtained from activated sludge. The system was operated under two different sets of conditions (setup 1 and 2), maintaining a system total retention time of 12 hours and an OLR of 2.25 Cmmol/L.h-1. An average PHB-content of 3.3 % wt was obtained in setup 1 and 4.8% wt in setup 2. Several other experiments were performed in order to better understand the continuous system behaviour, using biomass from the continuous system. With the fed-batch experiment a maximum of 8.1% PHB was stored and the maximum substrate uptake and specific growth rates obtained in the growth experiment (1.15 Cmol Cmol-1.h-1 and 0.53 Cmol Cmol-1.h-1) were close to the ones from continuous system (1.12 Cmol Cmol-1.h-1 and 0.59 Cmol Cmol-1.h-1). The microbial community was characterized trough microscopic visualization, Denaturing Gradient Gel Electrophoresis (DGGE) analysis and Fluorescent in situ hybridization (FISH). The last studied performed mimicked the continuous system by building up a SBR system with all the same operational conditions while adding an extra acetate dosage during the 12 h cycle, simulating the substrate passing from the feast to the famine reactors under continuous operation. It was shown that possibly the continuous system was not able to efficiently select for PHB storing organisms under the operational conditions imposed, although the selected culture was capable of consuming the substrate and grow fast. This main conclusion might have resulted from two major factors affecting the system performance: the ammonium concentration in the Feast reactor and the amount of substrate leaching from the Feast to the Famine reactor.