740 research outputs found

    A Reminiscence of ”Mastermind”: Iris/Periocular Biometrics by ”In-Set” CNN Iterative Analysis

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    Convolutional neural networks (CNNs) have emerged as the most popular classification models in biometrics research. Under the discriminative paradigm of pattern recognition, CNNs are used typically in one of two ways: 1) verification mode (”are samples from the same person?”), where pairs of images are provided to the network to distinguish between genuine and impostor instances; and 2) identification mode (”whom is this sample from?”), where appropriate feature representations that map images to identities are found. This paper postulates a novel mode for using CNNs in biometric identification, by learning models that answer to the question ”is the query’s identity among this set?”. The insight is a reminiscence of the classical Mastermind game: by iteratively analysing the network responses when multiple random samples of k gallery elements are compared to the query, we obtain weakly correlated matching scores that - altogether - provide solid cues to infer the most likely identity. In this setting, identification is regarded as a variable selection and regularization problem, with sparse linear regression techniques being used to infer the matching probability with respect to each gallery identity. As main strength, this strategy is highly robust to outlier matching scores, which are known to be a primary error source in biometric recognition. Our experiments were carried out in full versions of two well known irises near-infrared (CASIA-IrisV4-Thousand) and periocular visible wavelength (UBIRIS.v2) datasets, and confirm that recognition performance can be solidly boosted-up by the proposed algorithm, when compared to the traditional working modes of CNNs in biometrics.info:eu-repo/semantics/publishedVersio

    Immigration and intra-industry trade : the relevance of language, qualification and economic integration

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    This paper analyses the immigration into Portugal between 2000 and 2005, estimating the effect of the increasing stock of immigrants and some of its characteristics on Portugal’s bilateral intra-industry trade with 37 countries. These comprise all the partner-states of the European Union (EU-27). Using panel data and the pseudo-likelihood logit estimator the results suggest that an increase of the immigrant stock will produce an increment in the intra-industry trade indexes. Our findings also suggest that immigrant qualifications and common language have a positive impact on intra-industry trade

    Effects of Immigration on Intra-Industry Trade: A logit analysis

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    This study estimates the effects of the immigration stock, as well as those of immigrants’ characteristics, such as having the same language as that of the host country and the level of qualification or entrepreneurship, on Portuguese intra-industry trade (IIT) by types, controlling for the effects of other socio-economic factors, like economic dimensions, price indexes and distance. In addition to the member-countries of the EU-27, the group of countries studied includes five African countries with Portuguese as their official language, known as the PALOPs, and the BRIC countries. Since indexes are fractional variables, the pseudo-likelihood Logit estimator was used on the panel data to obtain the empirical results. The study found that an increase of the immigrant stock will produce an increment in the trade indexes considered and this effect is enhanced if immigrants originate from a country where Portuguese is the official language, or if they are highly qualified, whereas immigrant entrepreneurs have no significant effec

    Modelling bilateral intra-industry trade indexes with panel data: a semiparametric approach

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    This paper focuses on the modelling of bilateral intra-industry trade indexes with panel data, applying a semiparametric approach. This extends the work of Papke and Wooldridge (J Econom 145: 121–133, 2008) for fractional responses, by introducing a nonparametric component to control for unobserved heterogeneity associated with the regressors. The proposed approach is based on the semi-mixed effects gen eralised linear model of Lombardía and Sperlich (Comput Stat Data Anal 56:2903– 2917, 2012), introduced in the context of small area statistics, and the semiparametric gravity model of Proença et al. (Empir Econ doi:10.1007/s00181-014-0891-x, 2014). The resulting nonlinear semiparametric model serves to explain the bilateral intra industry trade indexes between Portugal and the European Union, the BRIC emerging economies, and the five Portuguese-speaking African countries.info:eu-repo/semantics/publishedVersio

    Commensal-to-pathogen transition: One-single transposon insertion results in two pathoadaptive traits in Escherichia coli -macrophage interaction

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    There are no funders and sponsors indicated explicitly in the document. This deposit is composed by the main article plus the supplementary materials of the publication.Escherichia coli is both a harmless commensal in the intestines of many mammals, as well as a dangerous pathogen. The evolutionary paths taken by strains of this species in the commensal-to-pathogen transition are complex and can involve changes both in the core genome, as well in the pan-genome. One way to understand the likely paths that a commensal strain of E. coli takes when evolving pathogenicity is through experimentally evolving the strain under the selective pressures that it will have to withstand as a pathogen. Here, we report that a commensal strain, under continuous pressure from macrophages, recurrently acquired a transposable element insertion, which resulted in two key phenotypic changes: increased intracellular survival, through the delay of phagosome maturation and increased ability to escape macrophages. We further show that the acquisition of the pathoadaptive traits was accompanied by small but significant changes in the transcriptome of macrophages upon infection. These results show that under constant pressures from a key component of the host immune system, namely macrophage phagocytosis, commensal E. coli rapidly acquires pathoadaptive mutations that cause transcriptome changes associated to the host-microbe duet.There are no funders and sponsors indicated explicitly in the document.info:eu-repo/semantics/publishedVersio

    Human case of West Nile neuroinvasive disease in Portugal, summer 2015

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    A case of West Nile virus (WNV) infection was reported in the Algarve region, Portugal, in the first week of September 2015. WNV is known to circulate in Portugal, with occasional reports in horses and birds (2004 to 2011) and very sporadically human cases (in 2004 and in 2010). Here we present the clinical and laboratory aspects related to the first human case of West Nile neuroinvasive disease reported in Portugal

    Depth of cure of bulk-fill light cured composite resins with different initiators

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    Poster presented at the 3rd International Congress of CiiEM - Research and Innovation in Human and Health Sciences, Monte da Caparica, Portugal, 20-22 June 2018N/

    Direct Percutaneous Endoscopic Jejunostomy Using Single-Balloon Enteroscopy without Fluoroscopy: a Case Series

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    BACKGROUND: Direct percutaneous endoscopic jejunostomy (DPEJ) is a useful method to provide enteral nutrition to individuals when gastric feeding is not possible or contraindicated. The aim of this study was to analyze the efficacy and safety of DPEJ tube placement with the Gauderer-Ponsky technique by the pull method, using single-balloon enteroscopy (SBE) without fluoroscopy. METHODS: This is a retrospective analysis of patients undergoing SBE for DPEJ placement in a referral hospital between January 2010 and March 2016. Technical success, clinical success and procedure related complications were recorded. RESULTS: Twenty-three patients were included (17 males, median age 71 years, range 37-93 years). The most frequent indications for DPEJ were gastroesophageal cancer (n = 10) and neurological disease (n = 8). Eighty-seven percent of the patients had a contraindication to percutaneous endoscopic gastrostomy (PEG) and PEG was unsuccessful in the remaining patients. The technical success rate was 83% (19/23), transillumination was not possible in three patients and an accidental exteriorization of the bumper resulting in a jejunal perforation occurred in one patient. The clinical success was 100% (19/19). The median follow-up was five months (range 1-35 months). Apart from the case of jejunal perforation and the two cases of accidental exteriorization, there were no other complications during follow-up. The 6-month survival was 65.8% and the 1-year survival was 49.3%. CONCLUSION: DPEJ can be carried out successfully via SBE without fluoroscopy with a low rate of significant adverse events. Although, leaving the overtube in place during the bumper pulling can be useful for distal jejunal loops, it can be safely removed in proximal loops to minimize complications.info:eu-repo/semantics/publishedVersio

    Corioamnionite e Morbilidade Neonatal

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    CHORIOAMNIONITIS AND NEONATAL MORBIDITY Introduction - Several studies highlight the association between perinatal infection/ inflammation and neonatal morbidity, mainly bronchopulmonary dysplasia and periventricular leukomalacia. Aim – To evaluate the role of histological chorioamnionitis on the overall morbidity of preterm newborns. Methods – A retrospective study on preterm newborns less than 34 weeks gestational age at birth, and respective mothers, at three tertiary medical centers (Hospital de São João, Maternidade Júlio Dinis and Centro Hospitalar de Vila Nova de Gaia) in the north of Portugal, between January 2001 and December 2002. We evaluated the association between histological chorioamnionitis and the overall neonatal morbidity. The association between histological chorioamnionitis and acute (respiratory distress syndrome) and chronic (bronchopulmonary dysplasia) lung damage was also evaluated in the subgroup of less than 1000 g birthweight preterm neonates. Results – 452 [ M 253 / F 217; birthweight 1440 (515 – 2620) g; gestational age 31 (23 – 33) weeks] preterm newborns were included. The association between histological chorioamnionitis and the overall neonatal morbidity was: respiratory distress syndrome OR 1,5 (95% CI 0,94 – 2,31); bronchopulmonary dysplasia OR 2,6 (95% CI 1,16 – 6,03); patent ductus arteriosus OR 2,5 (95% CI 1,17 – 5,44); sepsis OR 1,2 (95% CI 0,9 – 2,13); necrotizing enterocolitis OR 1,4 (95% CI 0,9 – 1,76); intraventricular hemorrhage grades III-IV OR 2,5 (1,20 – 5,11); cystic periventricular leukomalacia OR 3,0 (1,5 – 6,07); retinopathy of prematurity OR 1,4 (95% CI 0,8 – 1,35). The association adjusted to birthweight and gestational age was: bronchopulmonary dysplasia OR 1,2 (95% CI 0,51 – 2,95); patent ductus arteriosus OR 0,9 (95% CI 0,4 – 2,35); intraventricular hemorrhage grades III-IV OR 0,9 (95% CI 0,39 – 2,28); cystic periventricular leukomalacia OR 2,2 (95% CI 1,03 – 4,61). The association between histological chorioamnionitis and lung damage in the subgroup of less than 1000 g birthweight preterm neonates was: respiratory distress syndrome OR 0,23 (95% CI 0,01 – 2,51); bronchopulmonary dysplasia OR 1,61 (95% CI 0,38 – 6,97). Conclusion – This study confirms the association between histological chorioamnionitis and cystic periventricular leukomalacia of the preterm newborn

    Direct Percutaneous Endoscopic Jejunostomy Using Single-Balloon Enteroscopy without Fluoroscopy: a Case Series

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    BACKGROUND: Direct percutaneous endoscopic jejunostomy (DPEJ) is a useful method to provide enteral nutrition to individuals when gastric feeding is not possible or contraindicated. The aim of this study was to analyze the efficacy and safety of DPEJ tube placement with the Gauderer-Ponsky technique by the pull method, using single-balloon enteroscopy (SBE) without fluoroscopy. METHODS: This is a retrospective analysis of patients undergoing SBE for DPEJ placement in a referral hospital between January 2010 and March 2016. Technical success, clinical success and procedure related complications were recorded. RESULTS: Twenty-three patients were included (17 males, median age 71 years, range 37-93 years). The most frequent indications for DPEJ were gastroesophageal cancer (n = 10) and neurological disease (n = 8). Eighty-seven percent of the patients had a contraindication to percutaneous endoscopic gastrostomy (PEG) and PEG was unsuccessful in the remaining patients. The technical success rate was 83% (19/23), transillumination was not possible in three patients and an accidental exteriorization of the bumper resulting in a jejunal perforation occurred in one patient. The clinical success was 100% (19/19). The median follow-up was five months (range 1-35 months). Apart from the case of jejunal perforation and the two cases of accidental exteriorization, there were no other complications during follow-up. The 6-month survival was 65.8% and the 1-year survival was 49.3%. CONCLUSION: DPEJ can be carried out successfully via SBE without fluoroscopy with a low rate of significant adverse events. Although, leaving the overtube in place during the bumper pulling can be useful for distal jejunal loops, it can be safely removed in proximal loops to minimize complications.info:eu-repo/semantics/publishedVersio
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