257 research outputs found

    Sistema de classificação de sinais de electroencefalograma

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    Mestrado em Engenharia Electrónica e TelecomunicaçõesEste trabalho apresenta um método para detectar actividade epiléptica em sinais de Electroencefalograma (EEG). O sistema é constituído por dois blocos, o primeiro trata da extracção de características do sinal EEG e o segundo procede á classificação do sinal em 2 classes. As características são medidas (como energia média, máximo do sinal, entre outras) extraídas a partir das saídas da decomposição discreta em wavelet do sinal. A classificação será tratada como um problema binário, assumindo-se que os dois tipos de classes (Classe não epiléptica e Classe epiléptica), são lin- earmente separáveis. O classificador utilizado é do tipo Support Vector Machine (SVM). O desempenho do sistema é também apresentado segundo um método ex- perimental, onde diferentes estratégias para a organização do conjunto de treino são debatidas. Para avaliar a performance deste sistema, comparativamente a outros, utilizou-se uma base de dados publicada [1]. Os resultados obtidos usando um classificador linear apresentaram-se prometedores, com uma precisão situada entre 89,74% - 99.87%.This work presents a method for detecting epileptic activity in Electroencephalogram (EEG) signals. The system is divided into two blocks, the first dealing with feature extraction from the EEG and the second with the classification problem. The features are measures (like energy, maximum and so on) taken into the outputs of the discrete wavelet decomposition of the signal. To perform the classification the support vector machine was chosen. This binary classifier was designed assuming that the two classes (epileptic and non-epileptic activity) are linearly separable. The performance of the system is also presented using an experimental study where diferent strategies to organize the training data sets are also discussed. The accuracy of the system is in range of 89,74% - 99,87% in a publicly available data set used by other works

    Mediterranean mesocarnivores in spatially structured managed landscapes : community organisation in time and space

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    During the final stage of the study GCS was funded by a doctoral grant from FCT (PD/BD/114037/2015). TAM thanks support by CEAUL (funded by FCT project – UID/MAT/00006/2013).In the multi-functional and biodiverse cork oak landscapes of Iberia (Montado), agro-silvo-pastoral practices promote landscape heterogeneity and create intricate habitat and resource availability patterns. We used camera-traps to investigate the temporal and spatial organisation of a mesocarnivore community in a Montado landscape in central Portugal. The target carnivore assemblage was largely dominated by three generalist species – the red fox Vulpes vulpes, the European badger Meles meles and the Egyptian mongoose Herpestes ichneumon – while remaining community members – the common genet Genetta genetta and the feral cat Felis silvestris spp. – exhibited restricted distributions. Interspecific differences in activity rhythms and habitat use were particularly marked among widespread species. Low temporal overlap was reported between the diurnal mongoose and predominantly nocturnal red fox and badger. For the latter two species, contrasting differences in habitat use were associated with anthropogenic-induced environmental heterogeneity. Whereas the red fox used more intensively Montado areas preserving dense shrubby understory and avoided semi-disturbed mosaics of sparse shrubs, the badgers displayed the opposite pattern. Our findings add to previous evidence suggesting that the spatial structure created in highly managed landscapes, particularly the diversity of resulting understory structures, promotes the abundance and spread of generalist mesocarnivore species. These may benefit from the surplus of resource amount (e.g. prey) and the creation of different human-made habitats conditions that provide particular combinations of ecological resources favourable to each species requirements. We concur the common view that maintaining understory heterogeneity in Montado landscapes, menaced by current intensification and extensification trends, is important where carnivore persistence is a relevant conservation goal, but alert for potential effects on carnivore assemblages structuring and impacts for specialist species less tolerant to disturbance.PostprintPeer reviewe

    Dynamic processes of an airport's system. A value network analysis

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    The performance of an airport and its efficiency has been measured generally from its operational and financial data, and on that basis, classified its relative position in the set of airports. But this methodology, by itself, is insufficient to determine relationships between a given position in the ranking of an airport and the generated value associated with that position, either within the entire business system of the airport or along the inter-relationships that it establishes with the surrounding community. We argue that networks are fundamental instruments for the development of the business system of airport’s landside areas. Applying the Value Network Analysis (VNA) to the Air Cargo we concluded that this approach provided a network ecosystem perspective into how processes and people create value within the Cargo Network

    Accounting for detection unveils the intricacy of wild boar and rabbit co-occurrence patterns in a Mediterranean landscape

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    This study was conducted at a research and monitoring station of the LTsER Montado platform (http://www.ltsermontado.pt/) through a research protocol established between Companhia das Lezírias S.A. (CL) and Faculdade de Ciências da Universidade de Lisboa (FCUL), under the strategic plan of the Centre for Ecology, Evolution and Environmental Changes (cE3c) and with the support of the Foundation for Science and Technology (FCT, UID/BIA/00329/2019). T.A.M. thanks partial support by CEAUL (funded by FCT through the project UID/MAT/00006/2019). G.C.S. was funded by a doctoral grant from FCT (PD/BD/114037/2015).The patterns of species co-occurrence have long served as a primary approach to explore concepts of interspecific interaction. However, the interpretation of such patterns is difficult as they can result from several complex ecological processes, in a scale-dependent manner. Here, we aim to investigate the co-occurrence pattern between European rabbit and wild boar in an estate in Central Portugal, using two-species occupancy modelling. With this framework, we tested species interaction for occupancy and detection, but also the interdependencies between both parameters. According to our results, the wild boar and European rabbit occurred independently in the study area. However, model averaging of the detection parameters revealed a potential positive effect of wild boar’s presence on rabbit’s detection probability. Upon further analysis of the parameter interdependencies, our results suggested that failing to account for a positive effect on rabbit’s detection could lead to potentially biased interpretations of the co-occurrence pattern. Our study, in spite of preliminary, highlights the need to understand these different pathways of species interaction to avoid erroneous inferences.Publisher PDFPeer reviewe

    Training evaluation in male age-group swimmers

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    Monitoring the training process represents an important task during sports preparation. However, not always the applied protocols help to address the coaches’ concerns, namely regarding its complexity and difficulty to be used in large samples. Therefore, the aim of this study was to apply a simple protocol to control the training process in a group of male age-group swimmer

    Obsessive–compulsive disorder as a visual processing impairment

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    OCD has been hypothesized to involve the failures in both cognitive and behavioral inhibitory processes. There is evidence that the hyperactivation of cortical–subcortical pathways may be involved in the failure of these inhibitory systems associated with OCD. Despite this consensus on the role of frontal–subcortical pathways in OCD, recent studies have been showing that brain regions other than the frontal–subcortical loops may be needed to understand the different cognitive and emotional deficits in OCD. Some studies have been finding evidence for decreased metabolic activity in areas such as left inferior parietal and parieto- occipital junction suggesting the possible existence of visual processing deficits. While there has been inconsistent data regarding visual processing in OCD, recent studies have been claiming that these patients have abnormal patterns of visual processing social rich stimuli, particularly emotional arousing stimuli. Thus, in this article, we hypothesize that the fronto-subcortical activation consistently found in OCD may be due to a deactivation of occipital/parietal regions associated with visual-perceptual processing of incoming social rich stimuli. Additionally, this dissociation may be more evident as the emotional intensity of the social stimulus increases

    Reduced mu opioid receptor availability in schizophrenia revealed with [11C]-carfentanil positron emission tomographic Imaging.

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    Negative symptoms, such as amotivation and anhedonia, are a major cause of functional impairment in schizophrenia. There are currently no licensed treatments for negative symptoms, highlighting the need to understand the molecular mechanisms underlying them. Mu-opioid receptors (MOR) in the striatum play a key role in hedonic processing and reward function and are reduced post-mortem in schizophrenia. However, it is unknown if mu-opioid receptor availability is altered in-vivo or related to negative symptoms in schizophrenia. Using [11 C]-carfentanil positron emission tomography (PET) scans in 19 schizophrenia patients and 20 age-matched healthy controls, here we show a significantly lower MOR availability in patients with schizophrenia in the striatum (Cohen's d = 0.7), and the hedonic network. In addition, we report a marked global increase in inter-regional covariance of MOR availability in schizophrenia, largely due to increased cortical-subcortical covariance

    Chondrosia reniformis marine-sponge collagen membranes for skin re-epithelialization

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    Chondrosia reniformis collagen has been identified as mainly of type IV. Being collagen IV the main component of the epidermal basal layer [1], C. reniformis represents a valuable source to be explored in the skin regeneration field. This work envisaged the production of C. reniformis collagen membranes for the selection of rapidly adherent epidermal cells, like the commercial collagen coatings, and for their subsequent culture. This approach would permit a single system for culturing and carrying basal epidermal cells aimed at re-epithelialize skin wounds. Materials and Methods The collagen of C. reniformis marine-sponge was extracted with 100mM Tris-HCl, 10mM EDTA, 8M urea and 100mM 2-mercaptoethanol. To define the best re-solubilization conditions, the obtained precipitate was dissolved in five different solutions: Solution A: 100mM Tris-HCl+8M Urea+10mM EDTA (pH 9.5); Solution B: 50mM Tris-HCl+1M NaCl (pH 7.4); Solution C: 100mM Tris-HCl (pH 7.4); Solution D: 0.5% H2O2 (v/v) (pH 11) and Solution E: 100mM Tris-HCl (pH 9.5). Solutions of 1% collagen were prepared and cross-linking was performed with HMDI, genipin and EDC/NHS at different concentrations. The membranes were obtained by solvent-casting and/or freeze-drying, and their stability was tested both in PBS and culture medium, for at least 7 days. Morphological characterization of the membranes was carried out by scanning electron microscopy (SEM). Cytotoxicity, based on metabolic activity (MTS assay) and cell proliferation (DNA quantification) analysis of the 100mM Tris-HCl (pH 9.5) and 8mM EDC/NHS cross-linked collagen membranes, was assessed with L929 cells. Results were analyzed by IBM SPSS Statistics Version 20 using one-way ANOVA and Kruskall-Wallis test. Significance was set for

    Evaluation of the potential of collagen from codfish skin as a biomaterial for biomedical applications

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    Collagen is one of the most widely used biomaterials, not only due its biocompatibility, biodegradability and weak antigenic potential, but also due to its role in the structure and function of tissues. Searching for alternative collagen sources, the aim of this study was to extract collagen from the skin of codfish, previously obtained as a by-product of fish industrial plants, and characterize it regarding its use as a biomaterial for biomedical application, according to American Society for Testing and Materials (ASTM) Guidelines. Collagen type I with a high degree of purity was obtained through acid-extraction, as confirmed by colorimetric assays, SDS-PAGE and amino acid composition. Thermal analysis revealed a denaturing temperature around 16 C. Moreover, collagen showed a concentration-dependent effect in metabolism and on cell adhesion of lung fibroblast MRC-5 cells. In conclusion, this study shows that collagen can be obtained from marine-origin sources, while preserving its bioactivity, supporting its use in biomedical applications.European Research Council grant agreement ERC-2012-ADG 20120216-321266 for the project ComplexiTEinfo:eu-repo/semantics/publishedVersio
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