410 research outputs found

    Mobilidade, acessibilidade e produtividade: nota sobre a valoração econômica do tempo de viagem na Região Metropolitana de São Paulo

    Get PDF
    O objetivo deste artigo é introduzir no debate sobre valoração do tempo de viagem dos trabalhadores urbanos uma visão alternativa sobre a integração de alguns de seus canais de transmissão para a economia. A relação entre tempo de deslocamento, mobilidade e produtividade é explorada, juntamente com a possibilidade de se capturar seus efeitos de equilíbrio geral em um sistema econômico espacial. O método proposto é aplicado para o caso da RMSP. Além de oferecermos parâmetros adicionais para avaliação econômica de projetos de mobilidade urbana na RMSP, efetuamos o cálculo das perdas econômicas associadas às fricções de mobilidade excessivas na região.

    Avaliação de redes neurais aplicadas à previsão de índices de mercados de ações

    Get PDF
    Artificial neural networks have been utilized in modeling solutions for time series forecasting problems arisen in different financial area segments such as financial statements analysis, macro-economic indicators, currency market, stock quotations and market indexes. When dealing with such problems, the forecasting model quality is usually appraised in terms of the difference between the actual value and the network forecasted value. But financial area applications also require that related financial goals such as profitability and low risk exposure be considered. The commonly used mean square error generally does not grant those needs are met. It seems then to be necessary to establish additional criteria considering specific financial goals. The current paper shows the results obtained in experiments carried on to compare different neural network architectures to forecast the São Paulo Stock Exchange Ibovespa index using different training criteria and performance evaluation strategies based on business and financial goalsAs redes neurais artificiais vêm sendo utilizadas na modelagem da solução de problemas de previsão de séries temporais em diferentes segmentos da área financeira, como por exemplo, análise de balanços, indicadores macroeconômicos, mercado de câmbio, cotação de ações e índices de mercados. Nesses problemas, é usual mensurar a qualidade do modelo de previsão através do uso de alguma medida de erro entre o valor real e o valor previsto pela rede. Contudo, aplicações na área financeira demandam o atendimento a objetivos financeiros subjacentes, tais como nível de lucratividade ou exposição ao risco. A obtenção de medidas de erro com magnitude pouco significativa não é garantia de atendimento a esses objetivos: há necessidade do estabelecimento de critérios adicionais, de forma a possibilitar a aferição da qualidade dos resultados obtidos à luz de objetivos financeiros específicos. Este artigo apresenta resultados de alguns experimentos realizados com vistas a comparar diferentes arquiteturas de redes neurais para a previsão do índice Ibovespa, da Bolsa de Valores de São Paulo, envolvendo diferentes critérios de treinamento e estratégias de avaliação do desempenho com base em objetivos financeiros e de negócio

    Multi-pathology detection and lesion localization in WCE videos by using the instance segmentation approach

    Get PDF
    The majority of current systems for automatic diagnosis considers the detection of a unique and previously known pathology. Considering specifically the diagnosis of lesions in the small bowel using endoscopic capsule images, very few consider the possible existence of more than one pathology and when they do, they are mainly detection based systems therefore unable to localize the suspected lesions. Such systems do not fully satisfy the medical community, that in fact needs a system that detects any pathology and eventually more than one, when they coexist. In addition, besides the diagnostic capability of these systems, localizing the lesions in the image has been of great interest to the medical community, mainly for training medical personnel purposes. So, nowadays, the inclusion of the lesion location in automatic diagnostic systems is practically mandatory. Multi-pathology detection can be seen as a multi-object detection task and as each frame can contain different instances of the same lesion, instance segmentation seems to be appropriate for the purpose. Consequently, we argue that a multi-pathology system benefits from using the instance segmentation approach, since classification and segmentation modules are both required complementing each other in lesion detection and localization. According to our best knowledge such a system does not yet exist for the detection of WCE pathologies. This paper proposes a multi-pathology system that can be applied to WCE images, which uses the Mask Improved RCNN (MI-RCNN), a new mask subnet scheme which has shown to significantly improve mask predictions of the high performing state-of-the-art Mask-RCNN and PANet systems. A novel training strategy based on the second momentum is also proposed for the first time for training Mask-RCNN and PANet based systems. These approaches were tested using the public database KID, and the included pathologies were bleeding, angioectasias, polyps and inflammatory lesions. Experimental results show significant improvements for the prFCT national funds, under the national support to R&D units grant, through the reference project UIDB/04436/2020 and UIDP/04436/2020 and through the PhD Grants with the references SFRH/BD/92143/2013 and SFRH/BD/139061/201

    Análise de sentimento dos usuários do Ministério de Infraestrutura no twitter

    Get PDF
    Projeto final Análise de sentimento dos usuários do Ministério de Infraestrutura no Twitter, do curso Bootcamp Machine Learning, turma 1/21.10 páginasAnálise e Ciência de Dado

    Transvaginal electrical stimulation in the treatment of urinary incontinence

    Get PDF
    Apresentamos uma revisão atualizada da literatura científica sobre a utilização da eletroestimulação pélvica no tratamento das formas mais freqüentes de incontinência urinária feminina. Em 2001, no Ambulatório de Ginecologia do Hospital de Clínicas de Porto Alegre (HCPA), realizamos um ensaio clínico controlado comparando a estimulação elétrica transvaginal com placebo no tratamento da incontinência urinária de esforço, de urgência e mista. Nossos resultados foram semelhantes aos de estudos científicos disponíveis, demonstrando que a estimulação elétrica é uma opção terapêutica efetiva para o tratamento da incontinência urinária feminina.This paper presents a literature review on pelvic floor stimulation in the treatment of female urinary incontinence. During 2001, we performed a controlled clinical trial comparing transvaginal electrical stimulation and placebo in the treatment of stress, urgency and mixed incontinence. The results were similar to those from reported trials showing that electrical stimulation may be an ef fective therapeutic option in the treatment of female urinary incontinence

    Can the evolution of music be analyzed in a quantitative manner?

    Full text link
    We propose a methodology to study music development by applying multivariate statistics on composers characteristics. Seven representative composers were considered in terms of eight main musical features. Grades were assigned to each characteristic and their correlations were analyzed. A bootstrap method was applied to simulate hundreds of artificial composers influenced by the seven representatives chosen. Afterwards we quantify non-numeric relations like dialectics, opposition and innovation. Composers differences on style and technique were represented as geometrical distances in the feature space, making it possible to quantify, for example, how much Bach and Stockhausen differ from other composers or how much Beethoven influenced Brahms. In addition, we compared the results with a prior investigation on philosophy. Opposition, strong on philosophy, was not remarkable on music. Supporting an observation already considered by music theorists, strong influences were identified between composers by the quantification of dialectics, implying inheritance and suggesting a stronger master-disciple evolution when compared to the philosophy analysis.Comment: 8 pages, 6 figures, added references for sections 1 and 4.C, better mathematical description on section 2. New values and interpretation, now considering a bootstrap metho

    Liposomal formulations loaded with a eugenol derivative for application as insecticides: encapsulation studies and In silico identification of protein targets

    Get PDF
    Supplementary Materials can be downloaded at: https://www.mdpi.com/article/10.3390/nano12203583/s1,A recently synthesized new eugenol derivative, ethyl 4-(2-methoxy-4-(oxiran-2-ylmethyl)phenoxy)butanoate, with a high insecticidal activity against Sf9 (Spodoptera frugiperda) insect cells, was encapsulated in the liposomal formulations of egg-phosphatidylcholine/cholesterol (Egg-PC:Ch) 70:30 and 100% dioleoylphosphatidylglycerol (DOPG), aiming at the future application as insecticides. Compound-loaded DOPG liposomes have sizes of 274 ± 12 nm, while Egg-PC:Ch liposomes exhibit smaller hydrodynamic diameters (69.5 ± 7 nm), high encapsulation efficiency (88.8% ± 2.7%), higher stability, and a more efficient compound release, thus, they were chosen for assays in Sf9 insect cells. The compound elicited a loss of cell viability up to 80% after 72 h of incubation. Relevantly, nanoencapsulation maintained the toxicity of the compound toward insect cells while lowering the toxicity toward human cells, thus showing the selectivity of the system. Structure-based inverted virtual screening was used to predict the most likely targets and molecular dynamics simulations and free energy calculations were used to demonstrate that this molecule can form a stable complex with insect odorant binding proteins and/or acetylcholinesterase. The results are promising for the future application of compound-loaded nanoliposome formulations as crop insecticides.This research was funded by project PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER 030154) of the COMPETE2020 program, co-financed by the FEDER and the European Union. The authors also acknowledge the Foundation for Science and Technology (FCT, Portugal) and FEDERCOMPETE QREN-EU for financial support to the research centers CQUM (UID/QUI/00686/2021), CF-UM-UP (UIDB/04650/2020) and REQUIMTE (UIDB/50006/2020). Renato B. Pereira acknowledges PRIMA Foundation (H2020-PRIMA 2018—Section 2, Project MILKQUA) and FCT (PTDC/QUI-QFI/2870/2020) for additional funding. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and FCT

    Synthesis, computational and nanoencapsulation studies on eugenol-derived insecticides

    Get PDF
    A new set of alkoxy alcohols were synthesised by reaction of eugenol oxirane with aliphatic and aromatic alcohols. These eugenol derivatives were evaluated against their effect upon the viability of the insect cell line Sf9 (Spodoptera frugiperda). The most promising compounds, 4-(3-(tert-butoxy)-2-hydroxypropyl)-2-methoxyphenol and 4-(2-((4-fluorobenzyl)oxy)-3-hydroxypropyl)-2-methoxyphenol were submitted to in silico assays to predict possible targets. Throught an Inverted Virtual Screening approach, 23 common pesticide targets were screened and the top 2 targets predicted were further analyzed through molecular dynamics simulations and free energy calculations. In addition, these eugenol derivatives were subjected to encapsulation and release assays using liposome-based nanosystems of egg phosphatidylcholine/cholesterol (7:3), with encapsulation efficiencies higher than 90% and release profiles well described by both Korsmeyer-Peppas and Weibull models.This research was funded by the project PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154) of the COMPETE 2020 program, co-financed by the FEDER and the European Union. The authors also acknowledge the Foundation for Science and Technology (FCT, Portugal) and FEDERCOMPETE-QREN-EU for financial support to the research centers CQ-UM (UID/QUI/00686/2021), CF-UM-UP (UIDB/04650/2021) and REQUIMTE (UIDB/50006/2020). Renato B. Pereira acknowledges the PRIMA Foundation (H2020-PRIMA 2018-Section 2, Project MILKQUA) and FCT (PTDC/QUI-QFI/2870/2020) for the funding. The NMR spectrometer Bruker Avance III 400 was a part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT

    Selection and validation of reference genes by RT-qPCR under photoperiodic induction of flowering in sugarcane ( Saccharum spp.)

    Get PDF
    Although reference genes have previously been used in the expression analysis of genes involved in sugarcane flowering they had not been experimentally validated for stability and consistency of expression between different samples over a wide range of experimental conditions. Here we report the analysis of candidate reference genes in different tissue types, at different temporal time-points, in both short and long day photoperiodic treatments. The stability of the candidate reference genes in all conditions was evaluated with NormFinder, BestKeeper, and RefFinder algorithms that complement each other for a more robust analysis. As the Normfinder algorithm was more appropriate for our experimental conditions, greater emphasis was placed on Normfinder when choosing the most stable genes. UBQ1 and TUB were shown to be the most stable reference genes to use for normalizing RT-qPCR gene expression data during floral induction, whilst 25SrRNA1 and GAPDH were the least stable. Their use as a reference gene pair was validated by analyzing the expression of two differentially expressed target genes (PIL5 and LHP1). The UBQ1/TUB reference genes combination was able to reveal small significant differences in gene expression of the two target genes that were not detectable when using the least stable reference gene combination. These results can be used to inform the choice of reference genes to use in the study of the sugarcane floral induction pathway. Our work also demonstrates that both PIL5 and LHP1 are significantly up-regulated in the initial stages of photoperiodic induction of flowering in sugarcane
    • …
    corecore