Global localization with non-quantized local image features

In the field of appearance-based robot localization, the mainstream approach uses a quantized representation of local image features. An alternative strategy is the exploitation of raw feature descriptors, thus avoiding approximations due to quantization. In this work, the quantized and non-quantized representations are compared with respect to their discriminativity, in the context of the robot global localization problem. Having demonstrated the advantages of the non-quantized representation, the paper proposes mechanisms to reduce the computational burden this approach would carry, when applied in its simplest form. This reduction is achieved through a hierarchical strategy which gradually discards candidate locations and by exploring two simplifying assumptions about the training data. The potential of the non-quantized representation is exploited by resorting to the entropy-discriminativity relation. The idea behind this approach is that the non-quantized representation facilitates the assessment of the distinctiveness of features, through the entropy measure. Building on this finding, the robustness of the localization system is enhanced by modulating the importance of features according to the entropy measure. Experimental results support the effectiveness of this approach, as well as the validity of the proposed computation reduction methods.

A qualitative assessment of modularity in CaesarJ components based on implementations of design patterns

Tese de Mestrado em Engenharia Informática

Comparison of serum hepatitis B virus replication markers in patients with chronic hepatitis B: studies on HBeAg/Anti-HBe system, viral dna polymerase and HBV-DNA

The detection of HBV-DNA in serum by molecular hybridization is the most sensitive and specific marker of replication and infectivity of hepatitis B virus and currently is proposed as a routine diagnostic technique in the follow-up of HBV - related diseases. Comparing different techniques already described, we found that direct spotting of serum samples on nitrocellulose membranes under vacuum filtration, followed by denaturing and neutralizing washes is more practical, simple, sensible and reproducible. DNA polymerase assay using phosphonoformic acid as specific viral inhibitor has shown 86.8% of concordance with HBV-DNA detection, and so, it is an useful alternative in the follow-up of hepatitis B chronic patients. We found 19.2% HBeAg positive samples with no other markers of viral replication and no anti-HBe positive sample had detectable HBV-DNA. Discordance between the 2 systems have been extensively described, and we confirm this for the first time in our country. Molecular biological techniques are essential to determine the replication status of chronic hepatitis B patients.

ECG wave detector and delineation with wavelets

Proceedings of the International Conference on Computational Intelligence in Medicine Healthcare, CIMED 2005, Costa da Caparica, June 29 - July 1, 2005

Damage detection in structures using a transmissibility-based Mahalanobis distance

In this paper, a damage-detection approach using the Mahalanobis distance with structural forced dynamic response data, in the form of transmissibility, is proposed. Transmissibility, as a damage-sensitive feature, varies in accordance with the damage level. Besides, Mahalanobis distance can distinguish the damaged structural state condition from the undamaged one by condensing the baseline data. For comparison reasons, the Mahalanobis distance results using transmissibility are compared with those using frequency response functions. The experiment results reveal quite a significant capacity for damage detection, and the comparison between the use of transmissibility and frequency response functions shows that, in both cases, the different damage scenarios could be well detected. Copyright (c) 2015 John Wiley & Sons, Ltd.

The development of the N1 and N2 components in auditory oddball paradigms: a systematic review with narrative analysis and suggested normative values

Auditory event-related potentials (AERPs) are widely used in diverse fields of today’s neuroscience, concerning auditory processing, speech perception, language acquisition, neurodevelopment, attention and cognition in normal aging, gender, developmental, neurologic and psychiatric disorders. However, its transposition to clinical practice has remained minimal. Mainly due to scarce literature on normative data across age, wide spectrumof results, variety of auditory stimuli used and to different neuropsychological meanings of AERPs components between authors. One of the most prominent AERP components studied in last decades was N1, which reflects auditory detection and discrimination. Subsequently, N2 indicates attention allocation and phonological analysis. The simultaneous analysis of N1 and N2 elicited by feasible novelty experimental paradigms, such as auditory oddball, seems an objective method to assess central auditory processing. The aim of this systematic review was to bring forward normative values for auditory oddball N1 and N2 components across age. EBSCO, PubMed, Web of Knowledge and Google Scholarwere systematically searched for studies that elicited N1 and/or N2 by auditory oddball paradigm. A total of 2,764 papers were initially identified in the database, of which 19 resulted from hand search and additional references, between 1988 and 2013, last 25 years. A final total of 68 studiesmet the eligibility criteria with a total of 2,406 participants from control groups for N1 (age range 6.6–85 years; mean 34.42) and 1,507 for N2 (age range 9–85 years; mean 36.13). Polynomial regression analysis revealed thatN1latency decreases with aging at Fz and Cz,N1 amplitude at Cz decreases from childhood to adolescence and stabilizes after 30–40 years and at Fz the decrement finishes by 60 years and highly increases after this age. Regarding N2, latency did not covary with age but amplitude showed a significant decrement for both Cz and Fz. Results suggested reliable normative values for Cz and Fz electrode locations; however, changes in brain development and components topography over age should be considered in clinical practice.

Design and performance evaluation of turbo FDE receivers

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

DNA nanoprobes for molecular detection

Dissertação apresentada para obtenção do Grau de Doutor em Engenharia Biológica – especialidade Engenharia Genética, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Depressão : detecção, diagnóstico e tratamento. Estudo de prevalência e despite das perturbações depressivas e tratamento

RESUMO:A depressão clínica é uma patologia do humor, dimensional e de natureza crónica, evoluindo por episódios heterogéneos remitentes e recorrentes, de gravidade variável, correspondendo a categorias nosológicas porventura artificiais mas clinicamente úteis, de elevada prevalência e responsável por morbilidade importante e custos sociais crescentes, calculando-se que em 2020 os episódios de depressão major constituirão, em todo o mundo, a segunda causa de anos de vida com saúde perdidos. Como desejável, na maioria dos países os cuidados de saúde primários são a porta de entrada para o acesso à recepção de cuidados de saúde. Cerca de 50% de todas as pessoas sofrendo de depressão acedem aos cuidados de saúde primários mas apenas uma pequena proporção é correctamente diagnosticada e tratada pelos médicos prestadores de cuidados primários apesar dos tratamentos disponíveis serem muito efectivos e de fácil aplicabilidade. A existência de dificuldades e barreiras a vários níveis – doença, doentes, médicos, organizações de saúde, cultura e sociedade – contribuem para esta generalizada ineficiência de que resulta uma manutenção do peso da depressão que não tem sido possível reduzir através das estratégias tradicionais de organização de serviços. A equipa comunitária de saúde mental e a psiquiatria de ligação são duas estratégias de intervenção com desenvolvimento conceptual e organizacional respectivamente na Psiquiatria Social e na Psicossomática. A primeira tem demonstrado sucesso na abordagem clínica das doenças mentais graves na comunidade e a segunda na abordagem das patologias não psicóticas no hospital geral. Todavia, a efectividade destas estratégias não se tem revelado transferível para o tratamento das perturbações depressivas e outras patologias mentais comuns nos cuidados de saúde primários. Novos modelos de ligação e de trabalho em equipa multidisciplinar têm sido demonstrados como mais eficazes e custo-efectivos na redução do peso da depressão, ao nível da prestação dos cuidados de saúde primários, quando são atinentes com os seguintes princípios estratégicos e organizacionais: detecção sistemática e abordagem da depressão segundo o modelo médico, gestão integrada de doença crónica incluindo a continuidade de cuidados mediante colaboração e partilha de responsabilidades intersectorial, e a aposta na melhoria contínua da qualidade. Em Portugal, não existem dados fiáveis sobre a frequência da depressão, seu reconhecimento e a adequação do tratamento ao nível dos cuidados de saúde primários nem se encontra validada uma metodologia de diagnóstico simples e fiável passível de implementação generalizada. Foi realizado um estudo descritivo transversal com os objectivos de estabelecer a prevalência pontual de depressão entre os utentes dos cuidados de saúde primários e as taxas de reconhecimento e tratamento pelos médicos de família e testar metodologias de despiste, com base num questionário de preenchimento rápido – o WHO-5 – associado a uma breve entrevista estruturada – o IED. Foram seleccionados aleatoriamente 31 médicos de família e avaliados 544 utentes consecutivos, dos 16 aos 90 anos, em quatro regiões de saúde e oito centros de saúde dotados com 219 clínicos gerais. Os doentes foram entrevistados por psiquiatras, utilizando um método padronizado, o SCAN, para diagnóstico de perturbação depressiva segundo os critérios da 10ª edição da Classificação Internacional de Doenças. Apurou-se que 24.8% dos utentes apresentava depressão. No melhor dos cenários, menos de metade destes doentes, 43%, foi correctamente identificada como deprimida pelo seu médico de família e menos de 13% dos doentes com depressão estavam bem medicados com antidepressivo em dose adequada. A aplicação seriada dos dois instrumentos não revelou dificuldades tendo permitido a identificação de pelo menos 8 em cada 10 doentes deprimidos e a exclusão de 9 em cada 10 doentes não deprimidos. Confirma-se a elevada prevalência da patologia depressiva ao nível dos cuidados primários em Portugal e a necessidade de melhorar a capacidade diagnóstica e terapêutica dos médicos de família. A intervenção de despiste, que foi validada, parece adequada para ser aplicada de modo sistemático em Centros de Saúde que disponham de recursos técnicos e organizacionais para o tratamento efectivo dos doentes com depressão. A obtenção da linha de base de indicadores de prevalência, reconhecimento e tratamento das perturbações depressivas nos cuidados de saúde primários, bem como a validação de instrumentos de uso clínico, viabiliza a capacitação do sistema para a produção de uma campanha nacional de educação de grande amplitude como a proposta no Plano Nacional de Saúde 2004-2010.------- ABSTRACT: Clinical depression is a dimensional and chronic affective disorder, evolving through remitting and recurring heterogeneous episodes with variable severity corresponding to clinically useful artificial diagnostic categories, highly prevalent and producing vast morbidity and growing social costs, being estimated that in 2020 unipolar major depression will be the second cause of healthy life years lost all over the world. In most countries, primary care are the entry point for access to health care. About 50% of all individuals suffering from depression within the community reach primary health care but a smaller proportion is correctly diagnosed and treated by primary care physicians though available treatments are effective and easily manageable. Barriers at various levels – pertaining to the illness itself, to patients, doctors, health care organizations, culture and society – contribute to the inefficiency of depression management and pervasiveness of depression burden, which has not been possible to reduce through classical service strategies. Community mental health teams and consultation-liaison psychiatry, two conceptual and organizational intervention strategies originating respectively within social psychiatry and psychosomatics, have succeeded in treating severe mental illness in community and managing non-psychotic disorders in the general hospital. However, these strategies effectiveness has not been replicated and transferable for the primary health care setting treatment of depressive disorders and other common mental pathology. New modified liaison and multidisciplinary team work models have been shown as more efficacious and cost-effective reducing depression burden at the primary care level namely when in agreement with principles such as: systematic detection of depression and approach accordingly to the medical model, chronic llness comprehensive management including continuity of care through collaboration and shared responsibilities between primary and specialized care, and continuous quality improvement. There are no well-founded data available in Portugal for depression prevalence, recognition and treatment adequacy in the primary care setting neither is validated a simple, teachable and implementable recognition and diagnostic methodology for primary care. With these objectives in mind, a cross-sectional descriptive study was performed involving 544 consecutive patients, aged 16-90 years, recruited from the ambulatory of 31 family doctors randomized within the 219 physicians working in eight health centres from four health regions. Screening strategies were tested based on the WHO-5 questionnaire in association with a short structured interview based on ICD-10 criteria. Depression ICD-10 diagnosis was reached according to the gold standard SCAN interview performed by trained psychiatrists. Any depressive disorder ICD-10 diagnosis was present in 24.8% of patients. Through the use of favourable recognition criteria, 43% of the patients were correctly identified as depressed by their family doctor and about 13% of the depressed patients were prescribed antidepressants at an adequate dosage. The serial administration of both instruments – WHO-5 and short structured interview – was feasible, allowing the detection of eight in ten positive cases and the exclusion of nine in ten non-cases. In Portugal, at the primary care level, high depressive disorder prevalence is confirmed as well as the need to improve depression diagnostic and treatment competencies of family doctors. A two-stage screening strategy has been validated and seems adequate for systematic use in health centres where technical and organizational resources for the effective management of depression are made available. These results can be viewed as primary care depressive disorders baseline indicators of prevalence, detection and treatment and, along with clinical useful instruments, the health system is more capacitated for the establishment of a national level large education campaign on depression such as proposed in the National Health Plan 2004-2010.

Prevalence of Trypanosoma cruzi and Leishmania chagasi infection and risk factors in a Colombian indigenous population

This study was carried out in order to obtain base-line data concerning the epidemiology of American Visceral Leishmaniasis and Chagas’ Disease in an indigenous population with whom the government is starting a dwelling improvement programme. Information was collected from 242 dwellings (1,440 people), by means of house to house interviews about socio-economic and environmental factors associated with Leishmania chagasi and Trypanosoma cruzi transmission risk. A leishmanin skin test was applied to 385 people and 454 blood samples were collected on filter paper in order to detect L. chagasi antibodies by ELISA and IFAT and T. cruzi antibodies by ELISA. T. cruzi seroprevalence was 8.7% by ELISA, L. chagasi was 4.6% and 5.1% by IFAT and ELISA, respectively. ELISA sensitivity and specificity for L. chagasi antibodies were 57% and 97.5% respectively, as compared to the IFAT. Leishmanin skin test positivity was 19%. L. chagasi infection prevalence, being defined as a positive result in the three-immunodiagnostic tests, was 17.1%. Additionally, 2.7% of the population studied was positive to both L. chagasi and T. cruzi, showing a possible cross-reaction. L. chagasi and T. cruzi seropositivity increased with age, while no association with gender was observed. Age (p<0.007), number of inhabitants (p<0.05), floor material (p<0.03) and recognition of vector (p<0.01) were associated with T. cruzi infection, whilst age ( p<0.007) and dwelling improvement (p<0.02) were associated with L. chagasi infection. It is necessary to evaluate the long-term impact of the dwelling improvement programme on these parasitic infections in this community.

Relationship between ISO 9001 certification maturity and EFQM business excellence model results

Purpose: This exploratory research evaluates if there is a relationship between the number of years since an organization has achieved ISO 9001 certification and the highest level of recognition received by the same organization with the EFQM Business Excellence Model. Methodology/Approach: After state of the art review a detailed comparison between both models was made. Fifty two Portuguese organizations were considered and Correlation coefficient Spearman Rho was used to investigate the possible relationships. Findings: Conclusion is that there is indeed a moderate positive correlation between these two variables, the higher the number of years of ISO 9001 certification, the higher the results of the organization EFQM model evaluation and recognition. This supports the assumption that ISO 9001 International Standard by incorporating many of the principles present in the EFQM Business Excellence Model is consistent with this model and can be considered as a step towards that direction. Research Limitation/implication: Due to the dynamic nature of these models that might change over time and the possible time delays between implementation and results, more in-depth studies like experimental design or a longitudinal quasi-experimental design could be used to confirm the results of this investigation. Originality/Value of paper: This research gives additional insights on conjunct studies of both models. The use of external evaluation results carried out by the independent EFQM assessors minimizes the possible bias of previous studies accessing the value of ISO 9001 certification.

Radar Based Collision detection developments on USV ROAZ II

This work presents the integration of obstacle detection and analysis capabilities in a coherent and advanced C&C framework allowing mixed-mode control in unmanned surface systems. The collision avoidance work has been successfully integrated in an operational autonomous surface vehicle and demonstrated in real operational conditions. We present the collision avoidance system, the ROAZ autonomous surface vehicle and the results obtained at sea tests. Limitations of current COTS radar systems are also discussed and further research directions are proposed towards the development and integration of advanced collision avoidance systems taking in account the different requirements in unmanned surface vehicles.

Fractional Dynamics in Forest Fires

Every year forest fires consume large areas, being a major concern in many countries like Australia, United States and Mediterranean Basin European Countries (e.g., Portugal, Spain, Italy and Greece). Understanding patterns of such events, in terms of size and spatiotemporal distributions, may help to take measures beforehand in view of possible hazards and decide strategies of fire prevention, detection and suppression. Traditional statistical tools have been used to study forest fires. Nevertheless, those tools might not be able to capture the main features of fires complex dynamics and to model fire behaviour [1]. Forest fires size-frequency distributions unveil long range correlations and long memory characteristics, which are typical of fractional order systems [2]. Those complex correlations are characterized by self-similarity and absence of characteristic length-scale, meaning that forest fires exhibit power-law (PL) behaviour. Forest fires have also been proved to exhibit time-clustering phenomena, with timescales of the order of few days [3]. In this paper, we study forest fires in the perspective of dynamical systems and fractional calculus (FC). Public domain forest fires catalogues, containing data of events occurred in Portugal, in the period 1980 up to 2011, are considered. The data is analysed in an annual basis, modelling the occurrences as sequences of Dirac impulses. The frequency spectra of such signals are determined using Fourier transforms, and approximated through PL trendlines. The PL parameters are then used to unveil the fractional-order dynamics characteristics of the data. To complement the analysis, correlation indices are used to compare and find possible relationships among the data. It is shown that the used approach can be useful to expose hidden patterns not captured by traditional tools.

Detection of the peanut allergen Ara h 6 in foodstuffs using a voltammetric biosensing approach

A voltammetric biosensor for Ara h 6 (a peanut allergen) detection in food samples was developed. Gold nanoparticle-modified screen-printed carbon electrodes were used to develop a sandwich-type immunoassay using two-monoclonal antibodies. The antibody-antigen interaction was detected through the electrochemical detection of enzymatically deposited silver. The immunosensor presented a linear range between 1 and 100 ng/ml, as well as high precision (inter-day RSD ≤9.8 %) and accuracy (recoveries ≥96.7 %). The detection and quantification limits were 0.27 and 0.88 ng/ml, respectively. It was possible to detect small levels of Ara h 6 in complex food matrices.

New approach for vitamin E extraction in rainbow trout flesh: Application in fish fed commercial and red seaweed-supplemented diets

A vitamin E extraction method for rainbow trout flesh was optimized, validated, and applied in fish fed commercial and Gracilaria vermiculophylla-supplemented diets. Five extraction methods were compared. Vitamers were analyzed by HPLC/DAD/fluorescence. A solid-liquid extraction with n-hexane, which showed the best performance, was optimized and validated. Among the eight vitamers, only α- and γ-tocopherol were detected in muscle samples. The final method showed good linearity (>0.999), intra- (<3.1%) and inter-day precision (<2.6%), and recoveries (>96%). Detection and quantification limits were 39.9 and 121.0 ng/g of muscle, for α-tocopherol, and 111.4 ng/g and 337.6 ng/g, for γ-tocopherol, respectively. Compared to the control group, the dietary inclusion of 5% G. vermiculophylla resulted in a slight reduction of lipids in muscle and, consequently, of α- and γ-tocopherol. Nevertheless, vitamin E profile in lipids was maintained. In general, the results may be explained by the lower vitamin E level in seaweed-containing diet. Practical Applications: Based on the validation results and the low solvent consumption, the developed method can be used to analyze vitamin E in rainbow trout. The results of this work are also a valuable information source for fish feed industries and aquaculture producers, which can focus on improving seaweed inclusion in feeds as a source of vitamin E in fish muscle and, therefore, take full advantage of all bioactive components with an important role in fish health and flesh quality.