711 research outputs found

    Indeterminate thyroid cytology: Detecting malignancy using analysis of nuclear images

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    Background: Thyroid nodules diagnosed as 'atypia of undetermined significance/ follicular lesion of undetermined significance' (AUS/FLUS) or 'follicular neoplasm/ suspected follicular neoplasm' (FN/SFN), according to Bethesda’s classification, represena challenge in clinical practice. Computerized analysis of nuclear images (CANI) could be a useful tool for these cases. Our aim was to evaluate the ability of CANI to correctly classify AUS/FLUS and FN/SFN thyroid nodules for malignancy. Methods: We studied 101 nodules cytologically classified as AUS/FLUS (n = 68) or FN/SFN (n = 33) from 97 thyroidectomy patients. Slides with cytological material were submitted for manual selection and analysis of the follicular cell nuclei for morphometric and texture parameters using ImageJ software. The histologically benign and malignant lesions were compared for such parameters which were then evaluated for the capacity to predict malignancy using the classification and regression trees gini model. The intraclass coefficient of correlation was used to evaluate method reproducibility. Results: In AUS/FLUS nodule analysis, the benign and malignant nodules differed for entropy (P < 0.05), while the FN/SFN nodules differed for fractal analysis, coefficient of variation (CV) of roughness, and CV-entropy (P < 0.05). Considering the AUS/FLUS and FN/SFN nodules separately, it correctly classified 90.0 and 100.0% malignant nodules, with a correct global classification of 94.1 and 97%, respectively. We observed that reproducibility was substantially or nearly complete (0.61–0.93) in 10 of the 12 nuclear parameters evaluated. Conclusion: CANI demonstrated a high capacity for correctly classifying AUS/FLUS and FN/SFN thyroid nodules for malignancy. This could be a useful method to help increase diagnostic accuracy in the indeterminate thyroid cytology.This study received financial support from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP; processes number 2016/14987-0 and number 2016/14988-6). Further funding through 'Fundação para a Ciência e Tecnologi' – FCT and FEDER 'Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020'; by Operacional Programme for Competitiveness and Internationalization 'POCI' (Grant no. POCI-01-0145-FEDER-007274); by the 'Advancing cancer research: from basic knowledge to application' (grant no. NORTE-01-0145-FEDER-000029); and by the 'Projetos Estruturados de I & D & I', funded by Norte 2020 – Programa Operacional Regional do Norte

    A discrete time neural network model with spiking neurons II. Dynamics with noise

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    We provide rigorous and exact results characterizing the statistics of spike trains in a network of leaky integrate and fire neurons, where time is discrete and where neurons are submitted to noise, without restriction on the synaptic weights. We show the existence and uniqueness of an invariant measure of Gibbs type and discuss its properties. We also discuss Markovian approximations and relate them to the approaches currently used in computational neuroscience to analyse experimental spike trains statistics.Comment: 43 pages - revised version - to appear il Journal of Mathematical Biolog

    A Statistical Model for Estimating Maternal-Zygotic Interactions and Parent-of-Origin Effects of QTLs for Seed Development

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    Proper development of a seed requires coordinated exchanges of signals among the three components that develop side by side in the seed. One of these is the maternal integument that encloses the other two zygotic components, i.e., the diploid embryo and its nurturing annex, the triploid endosperm. Although the formation of the embryo and endosperm contains the contributions of both maternal and paternal parents, maternally and paternally derived alleles may be expressed differently, leading to a so-called parent-of-origin or imprinting effect. Currently, the nature of how genes from the maternal and zygotic genomes interact to affect seed development remains largely unknown. Here, we present a novel statistical model for estimating the main and interaction effects of quantitative trait loci (QTLs) that are derived from different genomes and further testing the imprinting effects of these QTLs on seed development. The experimental design used is based on reciprocal backcrosses toward both parents, so that the inheritance of parent-specific alleles could be traced. The computing model and algorithm were implemented with the maximum likelihood approach. The new strategy presented was applied to study the mode of inheritance for QTLs that control endoreduplication traits in maize endosperm. Monte Carlo simulation studies were performed to investigate the statistical properties of the new model with the data simulated under different imprinting degrees. The false positive rate of imprinting QTL discovery by the model was examined by analyzing the simulated data that contain no imprinting QTL. The reciprocal design and a series of analytical and testing strategies proposed provide a standard procedure for genomic mapping of QTLs involved in the genetic control of complex seed development traits in flowering plants

    Response of Benthic Foraminifera to organic matter quantity and quality and bioavailable concentrations of metals in Aveiro Lagoon (Portugal)

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    This work analyses the distribution of living benthic foraminiferal assemblages of surface sediments in different intertidal areas of Ria de Aveiro (Portugal), a polihaline and anthropized coastal lagoon. The relationships among foraminiferal assemblages in association with environmental parameters (temperature, salinity, Eh and pH), grain size, the quantity and quality of organic matter (enrichment in carbohydrates, proteins and lipids), pollution caused by metals, and mineralogical data are studied in an attempt to identify indicators of adaptability to environmental stress. In particular, concentrations of selected metals in the surficial sediment are investigated to assess environmental pollution levels that are further synthetically parameterised by the Pollution Load Index (PLI). The PLI variations allowed the identification of five main polluted areas. Concentrations of metals were also analysed in three extracted phases to evaluate their possible mobility, bioavailability and toxicity in the surficial sediment. Polluted sediment in the form of both organic matter and metals can be found in the most confined zones. Whereas enrichment in organic matter and related biopolymers causes an increase in foraminifera density, pollution by metals leads to a decline in foraminiferal abundance and diversity in those zones. The first situation may be justified by the existence of opportunistic species (with high reproduction rate) that can live in low oxic conditions. The second is explained by the sensitivity of some species to pressure caused by metals. The quality of the organic matter found in these places and the option of a different food source should also explain the tolerance of several species to pollution caused by metals, despite their low reproductive rate in the most polluted areas. In this study, species that are sensitive and tolerant to organic matter and metal enrichment are identified, as is the differential sensitivity/tolerance of some species to metals enrichment.CNPq [401803/2010-4]; [PEst-OE/CTE/UI4035/2014]info:eu-repo/semantics/publishedVersio

    Early Secreted Antigen ESAT-6 of Mycobacterium tuberculosis Promotes Protective T Helper 17 Cell Responses in a Toll-Like Receptor-2-dependent Manner

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    Despite its relatively poor efficacy, Bacillus Calmette-Guérin (BCG) has been used as a tuberculosis (TB) vaccine since its development in 1921. BCG induces robust T helper 1 (Th1) immune responses but, for many individuals, this is not sufficient for host resistance against Mycobacterium tuberculosis (M. tb) infection. Here we provide evidence that early secreted antigenic target protein 6 (ESAT-6), expressed by the virulent M. tb strain H37Rv but not by BCG, promotes vaccine-enhancing Th17 cell responses. These activities of ESAT-6 were dependent on TLR-2/MyD88 signalling and involved IL-6 and TGF-β production by dendritic cells. Thus, animals that were previously infected with H37Rv or recombinant BCG containing the RD1 region (BCG::RD1) exhibited improved protection upon re-challenge with virulent H37Rv compared with mice previously infected with BCG or RD1-deficient H37Rv (H37RvΔRD1). However, TLR-2 knockout (TLR-2-/-) animals neither showed Th17 responses nor exhibited improved protection in response to immunization with H37Rv. Furthermore, H37Rv and BCG::RD1 infection had little effect on the expression of the anti-inflammatory microRNA-146a (miR146a) in dendritic cells (DCs), whereas BCG and H37RvΔRD1 profoundly induced its expression in DCs. Consistent with these findings, ESAT-6 had no effect on miR146a expression in uninfected DCs, but dramatically inhibited its upregulation in BCG-infected or LPS-treated DCs. Collectively, our findings indicate that, in addition to Th1 immunity induced by BCG, RD1/ESAT-6-induced Th17 immune responses are essential for optimal vaccine efficacy

    Advanced impact integration platform for cooperative road use

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    In order to improve networks efficiency, a considerable number of studies has been addressing the potential of eco-friendly assignment solutions as alternative approaches to reduce emissions and/or fuel use. So far the majority of studies generally assumes that the most eco-friendly solutions are the ones that minimize the absolute amount of emissions produced along a certain trip. In this work a platform based on both empirical GPS data and microscopic simulation models of traffic, emissions, noise, and road safety was developed to examine in depth 4 routes of an origin-destination pair over a Portuguese city. In addition to the integrated externalities assessment based on state of the art techniques, a novelty of this work was the preliminary inclusion of social criteria in defining sustainable assignment solutions. This paper provides new insights about sustainable traffic management issues and addresses multiple novel route choice indicators. Specifically we found that the relative variation of the individual costs and total pollution produced among 4 routes varies to a factor of 1.4 while the variation of the potentially exposed population ranges up to a factor of 10. The main results confirm the need to take into account real-time urban activity patterns in order to effectively implement sustainable traffic management measures
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