524 research outputs found
Hypothetical answers to continuous queries over data streams
Continuous queries over data streams may suffer from blocking operations
and/or unbound wait, which may delay answers until some relevant input arrives
through the data stream. These delays may turn answers, when they arrive,
obsolete to users who sometimes have to make decisions with no help whatsoever.
Therefore, it can be useful to provide hypothetical answers - "given the
current information, it is possible that X will become true at time t" -
instead of no information at all.
In this paper we present a semantics for queries and corresponding answers
that covers such hypothetical answers, together with an online algorithm for
updating the set of facts that are consistent with the currently available
information
Raciocínio adaptativo de base emocional em agentes inteligentes
O projecto e implementação de agentes inteligentes capazes de comportamento eficaz em ambientes reais, onde a incerteza e o dinamismo são generalizados e onde tempo e recursos são limitados, levanta problemas importantes, relacionados quer com a capacidade adaptativa dos agentes, quer com a complexidade computacional dos processos cognitivos envolvidos, em particular de processos de raciocínio e planeamento. Neste artigo são apresentados mecanismos de base emocional que tornam possível a adaptação a ambientes dinâmicos e um uso controlado de recursos, através da focagem dos processos cognitivos. No sentido de avaliar a abordagem proposta são apresentados resultados experimentais em comparação com resultados de outras abordagens de referência.info:eu-repo/semantics/publishedVersio
A Multimodal Approach to Image Sentiment Analysis
Multimodal sentiment analysis is a process for the classi-
cation of the content of composite comments in social media at the
sentiment level that takes into consideration not just the textual content
but also the accompanying images. A composite comment is normally
represented by the union of text and image. Multimodal sentiment analysis
has a great dependency on text to obtain its classi cation, because
image analysis can be very subjective according to the context where
the image is inserted. In this paper we propose a method that reduces
the text analysis dependency on this kind of classi cation giving more
importance to the image content. Our method is divided into three main
parts: a text analysis method that was adapted to the task, an image
classi er tuned with the dataset that we use, and a method that analyses
the class content of an image and checks the probability that it belongs
to one of the possible classes. Finally a weighted sum takes the results of
these methods into account to classify content according to its sentiment
class. We improved the accuracy on the dataset used by more than 9%.info:eu-repo/semantics/publishedVersio
Utilização de assinaturas lipídicas do músculo de polvo comum (Octopus vulgaris) para rastrear a sua origem geográfica
In recent decades, the common octopus (Octopus vulgaris) has become
one of the most important cephalopods in international fisheries due to
its high commercial and gastronomic value. In Mediterranean culture,
the octopus is a symbol of traditional cuisine for its exquisite flavor and
high nutritional value, namely its richness in long-chain polyunsaturated
omega-3 fatty acids. Most consumers consider that knowing the origin of
seafood is extremely important, encouraging the development of reliable
methods to trace the geographical origin of these highly-value products.
Recently, the use of lipidomic tools has opened new opportunities in the
traceability of the geographic origin of seafood products. Lipids, as the
main constituents of biological membranes and energy reserves, reflect
organisms' biochemical composition, which in turn is influenced by their
diet and habitat conditions. This study aimed to determine the lipidomic
fingerprints in the muscle of O. vulgaris captured along the Iberian
Atlantic coast and use these profiles to determine their origin place.
Samples of O. vulgaris were acquired in commercially relevant ports for
fishing for common octopus on the Atlantic coast of the Iberian
Peninsula (Ria de Arousa, Ria de Pontevedra, Peniche, Sesimbra and
Santa Luzia). The recorded results allowed to determine that there are no
significant differences in total lipid extracts. However, on what concerns
phospholipid content, samples from Peniche exhibited significantly
lower values. The analysis of the octopus lipidome allowed the
identification of more than 300 molecular lipid species and 13 different
lipid classes, evidencing that this cephalopod is a rich source of
plasmalogens phospholipids, ceramides and long chain polyunsaturated
fatty acids. The statistical tools employed allowed to successfully
discriminate all five locations. The major contribution to this
discrimination is associated to minority molecular lipid species, some of
which are characterized by a high degree of unsaturation in their
composition. This study opens new perspectives for the use of lipidomic
analyses as a tool for the traceability of seafood products.Nas últimas décadas, o polvo comum (Octopus vulgaris) tem-se tornado
um dos cefalópodes mais importantes nas pescarias internacionais
devido ao seu elevado valor comercial e gastronómico. Na cultura
Mediterrânica, o polvo é um símbolo da cozinha tradicional pelo seu
requintado sabor e elevado valor nutricional, nomeadamente a sua
riqueza em ácidos gordos ómega-3 polinsaturados de cadeia longa. A
maioria dos consumidores considera que conhecer a proveniência dos
produtos do mar é de extrema importância, encorajando ao
desenvolvimento de métodos de confiança para permitir rastrear a
origem geográfica destes produtos de elevado valor económico.
Recentemente, o uso de ferramentas lipidómicas têm aberto novas
oportunidades na rastreabilidade da origem geográfica de produtos de
origem marinha. Os lípidos, como principais constituintes das
membranas biológicas e das reservas energéticas, refletem a composição
bioquímica dos organismos, que pela sua vez é influenciada diretamente
pela sua dieta e pelas condições do habitat. Este estudo pretende
determinar as impressões digitais lipidómicas no músculo de O. vulgaris
capturado ao longo da costa Ibérica Atlântica e usar estes perfis para
rastrear o seu local de origem.
As amostras biológicas de O. vulgaris analisadas foram adquiridas em
portos comercialmente relevantes para a pesca de polvo comum na costa
Atlântica da Península Ibérica (Ria de Arousa, Ria de Pontevedra,
Peniche, Sesimbra e Santa Luzia). Os resultados obtidos revelaram que
não existem diferenças significativas nos extratos totais de lípidos
analisados. Contudo, no que diz respeito ao conteúdo de fosfolípidos, as
amostras de Peniche exibiram valores significativamente inferiores. A
análise do lipidoma do músculo de polvo permitiu a identificação de
mais de 300 espécies moleculares lipídicas e de 13 classes diferentes
destes compostos, mostrando ser uma fonte rica em fosfolípidos
plasmalogénios, ceramidas e ácidos gordos de cadeia longa. As
ferramentas estatísticas utilizadas permitiram discriminar com sucesso as
cinco localidades de origem das amostras de polvo analisadas. A maior
contribuição para esta discriminação está associada a espécies
moleculares minoritárias, sendo algumas delas caracterizadas por um
elevado grau de insaturação na sua composição molecular. Este estudo
abre novas perspetivas para o uso das análises lipidómicas como
ferramenta para a rastreabilidade de produtos de origem marinha.Mestrado em Biologia Marinha Aplicad
Image Sentiment Analysis: Experimental Evaluation of Several Deep Learning Architectures
Image sentiment analysis is an important topic nowadays. It is possible
to use it to classify an image at sentiment level, as negative, neutral or
positive. However, to classify an image at this level is a hard challenge
because its semantic meaning can represent many scenarios. In this paper,
we present an analysis of several image classification methods that we
evaluate to improve the state of the art in a large tweet data set.info:eu-repo/semantics/publishedVersio
Previsão eleitoral para a Assembleia da República Portuguesa
Em trabalho anterior utilizaram-se técnicas de Data Mining para predizer resultados eleitorais, sem utilizar sondagens, recorrendo a variáveis socioeconómicas, disponíveis publicamente sobre Portugal, no período abrangido pelas treze eleições para a Assembleia da República, entre 1974 e 2009. No entanto, o espectro político considerado nesse trabalho não abrange os 100% dos votos expressos, mas apenas os quatro partidos com assento parlamentar regular desde 1975 cuja votação atinge cerca de 84%. Na abordagem anteriormente adoptada, cada um dos quatro partidos tradicionais foi tratado separadamente, resultando em previsões independentes. Neste artigo analisa-se a extensão desse trabalho à previsão do intervalo restante dos resultados eleitorais e a sua utilização para garantir a restrição de que a percentagem total de votos expressos soma 100%. Os resultados mostraram que os métodos anteriormente aplicados permitem obter previsões com resultados de qualidade similar para o conjunto das forças partidárias complementares.In earlier work, Data Mining techniques using a large number of public available socioeconomic variables about Portugal were used to predict election results between 1974 and 2009 (thirteen elections) for the Parliament of the Portuguese Republic. However, the political spectrum considered in that work does not cover 100% of the votes cast, but only the four parties with regular parliamentary seat since 1975, whose voting reaches about 84%. In the approach previously adopted, each of the four traditional parties was treated separately resulting in independent forecasts. In this paper we analyse the extension of that work to the forecasting of the remaining interval of the election results and its use to ensure the restriction that the total percentage of votes cast adds up to 100%. The results showed that the methods previously applied allow making predictions with similar quality for the remaining partisan forces
Assessment of Lactobacillus crispatus´ role in vaginal infections: friend or foe?
Lactobacillus spp. are the most prevalent microorganisms in the vaginal milleu. Several probiotic mechanisms have been associated with Lactobacillus, but the most relevant one is lactate production – resulting in a low pH value, typical of the healthy vagina. However, its pathogenic state is still unknown. We aim to elucidate the role of a commensal vaginal microorganism, Lactobacillus crispatus, in vaginal infections. Twenty-four vaginal washes have been collected from women attending a gynaecology consultation of a private clinic. The samples were categorized according with clinical diagnosis at the time of sampling. The distribution of bacterial species, and their prevalence was assessed by Next-Generation Sequencing of the 16S rRNA V4 region. In addition, L- and D-lactate concentration, and LDH enzymatic activity was quantified in all washes by a commercial kit. Detection of Candida spp. was performed by PCR. L. crispatus was dominant (>70%) in 11 out of 24 samples – diagnosed for vaginal atrophy (VA, 3), cytolytic vaginosis (CV, 2) and lactobacillosis (LB, 2). Lactate was increased in CV, LB and VA cases only. The remaining samples, diagnosed for vulvovaginal candidosis in its majority, had lower prevalence of L. crispatus; and lower to moderate lactate metabolite. There was not a direct relationship between LDH enzymatic activity and clinical diagnosis. L. crispatus dominance, associated with increased lactate production, was observed in CV, LB and VA cases. These results indicate that this microorganism might have a role in dysbiosis of the vagina associated with these specific pathologies.info:eu-repo/semantics/publishedVersio
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