171 research outputs found

    Deeply Virtual Compton Scattering in Improved Holographic QCD

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    We present our current progress in the holographic computation of the scattering amplitude for Deeply Virtual Compton Scattering (DVCS) processe, as a function of the Mandelstam invariant tt. We show that it is possible to describe simultaneously the differential cross-section and total cross-section of DVCS data with a single holographic model for the pomeron. Using data from H1-ZEUS we obtained a χdof21.5\chi^2_{dof} \sim 1.5 for the best fit to the data.Comment: 12 pages, 5 figures, accepted in Physics Letters

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

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    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

    A estação arqueológica das Boucinhas, Regueira, Vitorino de Piães, Ponte de Lima (Norte de Portugal)

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    Publicam-se os resultados das sondagens arqueológicas realizadas no povoado da Idade do Bronze da Boucinha, em Vitorino de Piães, Ponte de Lima.Projeto FCT: The Entre-Douro-e-Minho landscape since middle of 3rd to the end of 2nd millenia BC.info:eu-repo/semantics/publishedVersio

    Performance clínica de um novo software para detetar automaticamente angiectasias na endoscopia por cápsula

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    Background: Video capsule endoscopy (VCE) revolutionized the diagnosis and management of obscure gastrointestinal bleeding, though the rate of detection of small bowel lesions by the physician is still disappointing. Our group developed a novel algorithm (CMEMS-Uminho) to automatically detect angioectasias which display greater accuracy in VCE static frames than other methods previously published. We aimed to evaluate the algorithm overall performance and assess its diagnostic yield and usability in clinical practice. Methods: Algorithm overall performance was determined using 54 full-length VCE recordings. To assess its diagnostic yield and usability in clinical practice, 38 VCE examinations with the clinical diagnosis of angioectasias consecutively performed (2017-2018) were evaluated by three physicians with different experiences. The CMEMS-Uminho algorithm was also applied. The performance of the CMEMS-Uminho algorithm was defined by a positive concordance between a frame automatically selected by the software and a study independent capsule endoscopist. Results: Overall performance in complete VCE recordings was 77.7%, and diagnostic yield was 94.7%. There were significant differences between physicians in regard to global detection rate (p < 0.001), detection rate per capsule (p < 0.001), diagnostic yield (p = 0.007), true positive rate (p < 0.001), time (p < 0.001), and speed viewing (p < 0.001). The application of CMEMS-Uminho algorithm significantly enhanced all readers' global detection rate (p < 0.001) and the differences between them were no longer observed. Conclusion: The CMEMS-Uminho algorithm detained a good overall performance and was able to enhance physicians' performance, suggesting a potential usability of this tool in clinical practice.(undefined

    Weighted Betweenness for Multipath Networks

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    International audienceTypical betweenness centrality metrics neglect thepotential contribution of nodes that are near but not exactlyon shortest paths. The idea of this paper is to give morevalue to these nodes. We propose a weighted betweennesscentrality, a novel metric that assigns weights to nodes basedon the stretch of the paths they intermediate against theshortest paths. We compare the proposed metric with thetraditional and the distance-scaled betweenness metrics usingfour different network datasets. Results show that the weightedbetweenness centrality pinpoints and promotes nodes that areunderestimated by typical metrics, which can help to avoidnetwork disconnections and better exploit multipath protocols

    The Power of Quasi-Shortest Paths: ρ-Geodesic Betweenness Centrality

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    International audienceBetweenness centrality metrics usually underestimate the importance of nodes that are close to shortest paths but do not exactly fall on them. In this paper, we reevaluate the importance of such nodes and propose the ρ-geodesic betweenness centrality, a novel metric that assigns weights to paths (and, consequently, to nodes on these paths) according to how close they are to shortest paths. The paths that are just slightly longer than the shortest one are defined as quasi-shortest paths, and they are able to increase or to decrease the importance of a node according to how often the node falls on them. We compare the proposed metric with the traditional, distance-scaled, and random walk betweenness centralities using four network datasets with distinct characteristics. The results show that the proposed metric, besides better assessing the topological role of a node, is also able to maintain the rank position of nodes overtime compared to the other metrics; this means that network dynamics affect less our metric than others. Such a property could help avoid, for instance, the waste of resources caused when data follow only the shortest paths and reduce associated costs

    Community structure of shallow rocky shore fish in a tropical bay of the southwestern Atlantic

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    Os costões rochosos do Atlântico Sul Ocidental sustentam ricas comunidades de peixes recifais. Apesar disso, o conhecimento sobre essas comunidades em zonas tropicais continua escasso, especialmente no Brasil. No presente trabalho avaliamos parâmetros das comunidades de peixes recifais, tais como composição e estrutura trófica, além de sua interação com variáveis físicas e bióticas, em quatro costões rochosos tropicais na Baía de Todos os Santos, costa leste do Brasil. Durante seis meses 80 censos visuais foram realizados, nos quais 3.582 peixes pertencentes a 76 espécies foram registrados. Os peixes herbívoros territoriais e as algas filamentosas dominaram em todos os costões. A variação espacial na estrutura da comunidade de peixes esteve relacionada com a composição bêntica e profundidade. A elevada abundância observada de peixes herbívoros territoriais e invertívoros móveis pode ser devido à alta cobertura de algas filamentosas e à baixa profundidade e exposição às ondas. Além disso, esse padrão também pode ser explicado pela baixa densidade de herbívoros errantes e grandes carnívoros, provavelmente devido à intensa pressão da atividade pesqueira. Assim, novos estudos são necessários para avaliar o real estado de conservação destes ambientes, uma vez que estão localizados em posição singular na Baía de Todos os Santos, conectando recifes internos e externos da área.Southwestern Atlantic Ocean rocky shores sustain important reef fish communities. However, those communities in tropical regions are not well understood, especially in Brazil. In this present article we assess community parameters of reef fishes such as composition, trophic organization and their relationships with physical and biological factors on four tropical rocky shores in Todos os Santos Bay, southwestern Atlantic. During six months, a total of 80 visual censuses were performed, in which 3,582 fish belonging to 76 species were recorded. Territorial herbivorous fish and turf algae were dominant at all the sites. The spatial variability of fish community structure was related to the benthic cover composition and depth. The high abundance of territorial herbivores and mobile invertebrate feeders could be associated with high levels of turf cover, low wave exposure and shallow waters. Moreover, this fact could be a consequence of the low density of roving herbivores and large carnivores probably due to the pressure of intense fishing activity. Thus complementary studies are needed to evaluate the actual conservation status of these rocky shore reefs, singularly located habitats connecting inner and outer reefs in Todos os Santos Bay

    Oxidative precipitation synthesis of calcium-doped manganese ferrite nanoparticles for magnetic hyperthermia

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    Superparamagnetic nanoparticles are of high interest for therapeutic applications. In this work, nanoparticles of calcium-doped manganese ferrites (CaxMn1−xFe2O4) functionalized with citrate were synthesized through thermally assisted oxidative precipitation in aqueous media. The method provided well dispersed aqueous suspensions of nanoparticles through a one-pot synthesis, in which the temperature and Ca/Mn ratio were found to influence the particles microstructure and morphology. Consequently, changes were obtained in the optical and magnetic properties that were studied through UV-Vis absorption and SQUID, respectively. XRD and Raman spectroscopy studies were carried out to assess the microstructural changes associated with stoichiometry of the particles, and the stability in physiological pH was studied through DLS. The nanoparticles displayed high values of magnetization and heating efficiency for several alternating magnetic field conditions, compatible with biological applications. Hereby, the employed method provides a promising strategy for the development of particles with adequate properties for magnetic hyperthermia applications, such as drug delivery and cancer therapy.This work was funded by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CF-UM-UP (UIDB/04650/2020, UIDP/04650/2020), CQUM (UIDB/00686/2020), CICECO Aveiro Institute of Materials (UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020) and by Ministerio de Economía y Competitividad de España (PID2020-113704RB-I00 and PID2020-119242RB-I00), Xunta de Galicia (Centro Singular de Investigación de Galicia—Accreditation 2019-2022 ED431G 2019/06 and IN607A 2018/5 and project ED431C 2020-06), and European Union (EU-ERDF Interreg V-A—Spain-Portugal 0245_IBEROS_1_E, 0712_ACUINANO_1_E, and 0624_2IQBIONEURO_6_E, and Interreg Atlantic Area NANOCULTURE 1.102.531), and the European Union H2020-MSCA-RISE-2019 PEPSA-MATE project. S.R.S. (872233) Veloso acknowledges FCT for a PhD grant (SFRH/BD/144017/2019). Support from MAP-Fis Doctoral Programme is also acknowledged

    Clinicobiological, immunophenotypic, and molecular characteristics of monoclonal CD56‐/+dim chronic natural killer cell large granular lymphocytosis.

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    Am J Pathol. 2004 Oct;165(4):1117-27. Clinicobiological, immunophenotypic, and molecular characteristics of monoclonal CD56-/+dim chronic natural killer cell large granular lymphocytosis. Lima M, Almeida J, Montero AG, Teixeira Mdos A, Queirós ML, Santos AH, Balanzategui A, Estevinho A, Algueró Mdel C, Barcena P, Fonseca S, Amorim ML, Cabeda JM, Pinho L, Gonzalez M, San Miguel J, Justiça B, Orfão A. Serviço de Hematologia, Unidade de Citometria, Hospital Geral de Santo António, Rua D Manuel II, s/n, 4099-001 Porto, Portugal. [email protected]. Abstract Indolent natural killer (NK) cell lymphoproliferative disorders include a heterogeneous group of patients in whom persistent expansions of mature, typically CD56(+), NK cells in the absence of any clonal marker are present in the peripheral blood. In the present study we report on the clinical, hematological, immunophenotypic, serological, and molecular features of a series of 26 patients with chronic large granular NK cell lymphocytosis, whose NK cells were either CD56(-) or expressed very low levels of CD56 (CD56(-/+dim) NK cells), in the context of an aberrant activation-related mature phenotype and proved to be monoclonal using the human androgen receptor gene polymerase chain reaction-based assay. As normal CD56(+) NK cells, CD56(-/+dim) NK cells were granzyme B(+), CD3(-), TCRalphabeta/gammadelta(-), CD5(-), CD28(-), CD11a(+bright), CD45RA(+bright), CD122(+), and CD25(-) and they showed variable and heterogeneous expression of both CD8 and CD57. Nevertheless, they displayed several unusual immunophenotypic features. Accordingly, besides being CD56(-/+dim), they were CD11b(-/+dim) (heterogeneous), CD7(-/+dim) (heterogeneous), CD2(+) (homogeneous), CD11c(+bright) (homogeneous), and CD38(-/+dim) (heterogeneous). Moreover, CD56(-/+dim) NK cells heterogeneously expressed HLA-DR. In that concerning the expression of killer receptors, CD56(-/+dim) NK cells showed bright and homogeneous CD94 expression, and dim and heterogeneous reactivity for CD161, whereas CD158a and NKB1 expression was variable. From the functional point of view, CD56(-/+dim) showed a typical Th1 pattern of cytokine production (interferon-gamma(+), tumor necrosis factor-alpha(+)). From the clinical point of view, these patients usually had an indolent clinical course, progression into a massive lymphocytosis with lung infiltration leading to death being observed in only one case. Despite this, they frequently had associated cytopenias as well as neoplastic diseases and/or viral infections. In summary, we describe a unique and homogeneous group of monoclonal chronic large granular NK cell lymphocytosis with an aberrant activation-related CD56(-/+dim)/CD11b(-/+dim) phenotype and an indolent clinical course, whose main clinical features are related to concomitant diseases. PMID: 15466379 [PubMed - indexed for MEDLINE]PMCID: PMC161863
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