3,576 research outputs found

    Polarization of Multi-Agent Gradient Flows Over Manifolds With Application to Opinion Dynamics

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    peer reviewedMulti-agent systems are known to exhibit stable emergent behaviors, including polarization, over Rn\mathbb {R}^{n} or highly symmetric nonlinear spaces. In this article, we eschew linearity and symmetry of the underlying spaces, and study the stability of polarized equilibria of multi-agent gradient flows evolving on general hypermanifolds. The agents attract or repel each other according to the partition of the communication graph that is connected but otherwise arbitrary. The manifolds are outfitted with geometric features styled “dimples” and “pimples” that characterize the absence of flatness. The signs of inter-agent couplings together with these geometric features give rise to stable polarization under various sufficient conditions. We propose tangible interpretation of the system in the context of opinion dynamics, and highlight throughout the text its versatility in modeling diverse aspects of the polarization phenomenon

    Caracterização morfobiológica, morfométrica e ultraestrutural de isolados silvestres de Trypanosoma cruzi do estado do Rio de Janeiro, Brasil

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    Triatoma vitticeps is a triatomine with geographic distribution restrict to Brazil, which exhibits high prevalence of Trypanosoma cruzi natural infection. Of special epidemiologic concern, this species often invades households in the states of Rio de Janeiro, Minas Gerais and Espirito Santo. The objective of this study was to evaluate morphological and ultrastructural parameters on three T. cruzi isolates obtained from wild T. vitticeps specimens. The growth and cell differentiation of the parasite was evaluated through epimastigote and trypomastigote forms obtained in the growth curves for three distinct isolates. The maximum growth showed differences at the 20th day of the curve. Our in vitro results show a heterogeneity, regarding these features for samples cultivated under the same conditions. Morphometric analyzes based on the shape of epimastigotes and trypomastigotes corroborated such differentiation. These results highlight the need of better understanding the meaning of this diversity under an eco-epidemiological perspective792294303COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO CARLOS CHAGAS FILHO DE AMPARO À PESQUISA DO ESTADO DO RIO DE JANEIRO - FAPERJTriatoma vitticeps Ă© um triatomĂ­neo com distribuição geogrĂĄfica restrita ao territĂłrio brasileiro, apresentando alta prevalĂȘncia de infecção natural pelo Trypanosoma cruzi. Esta espĂ©cie Ă© relevante sob o ponto de vista epidemiolĂłgico por invadir domicĂ­lios com frequĂȘncia nos estados do Rio de Janeiro, Minas Gerais e EspĂ­rito Santo. O objetivo deste estudo foi avaliar parĂąmetros morfolĂłgicos e ultraestruturais, em trĂȘs isolados de T. cruzi obtidos a partir de triatomĂ­neos silvestres. O crescimento e a diferenciação celular do parasita foi avaliado atravĂ©s das formas epimastigotas e tripomastigotas obtidas nas curvas de crescimento para os trĂȘs isolados. O crescimento mĂĄximo mostrou diferenças no 20Âș dia da curva. Nossos resultados in vitro mostram uma heterogeneidade, em relação a essas caracterĂ­sticas para amostras cultivadas nas mesmas condiçÔes. As anĂĄlises morfomĂ©tricas baseadas na conformação de epimastigotas e trypomastigotes corroboraram essa diferenciação. Estes resultados ressaltam a necessidade de uma melhor compreensĂŁo do significado desta diversidade sob uma perspectiva eco-epidemiolĂłgicaThe authors thank “Fundação Carlos Chagas Filho de Amparo Ă  Pesquisa do Estado do Rio de Janeiro (FAPERJ); Coordenação de Aperfeiçoamento de Pessoal de NĂ­vel Superior (CAPES); Instituto Oswaldo Cruz, Fundação Oswaldo Cruz (IOC-FIOCRUZ), Brasi

    Evidence for an intermediate line region in AGN's inner torus region and its evolution from narrow to broad line Seyfert I galaxies

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    A two-components model for Broad Line Region (BLR) of Active Galactic Nuclei (AGN) has been suggested for many years but not widely accepted (e.g., Hu et al. 2008; Sulentic et al. 2000; Brotherton et al. 1996; Mason et al. 1996). This model indicates that the broad line can be described with superposition of two Gaussian components (Very Broad Gaussian Component (VBGC) and InterMediate Gaussian Component (IMGC)) which are from two physically distinct regions; i.e., Very Broad Line Region (VBLR) and InterMediate Line Region (IMLR). We select a SDSS sample to further confirm this model and give detailed analysis to the geometry, density and evolution of these two regions. Micro-lensing result of BLR in J1131-1231 and some unexplained phenomena in Reverberation Mapping (RM) experiment provide supportive evidence for this model. Our results indicate that the radius obtained from the emission line RM normally corresponds to the radius of the VBLR, and the existence of the IMGC may affect the measurement of the black hole masses in AGNs. The deviation of NLS1s from the M-sigma relation and the Type II AGN fraction as a function of luminosity can be explained in this model in a coherent way. The evolution of the two emission regions may be related to the evolutionary stages of the broad line regions of AGNs from NLS1s to BLS1s. Based on the results presented here, a unified picture of hierarchical evolution of black hole, dust torus and galaxy is proposed.Comment: 58 pages, 19 figures, 1 table. Matches the published versio

    Joint Effect of MCP-1 Genotype GG and MMP-1 Genotype 2G/2G Increases the Likelihood of Developing Pulmonary Tuberculosis in BCG-Vaccinated Individuals

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    We previously reported that the – 2518 MCP-1 genotype GG increases the likelihood of developing tuberculosis (TB) in non-BCG-vaccinated Mexicans and Koreans. Here, we tested the hypothesis that this genotype, alone or together with the – 1607 MMP-1 functional polymorphism, increases the likelihood of developing TB in BCG-vaccinated individuals. We conducted population-based case-control studies of BCG-vaccinated individuals in Mexico and Peru that included 193 TB cases and 243 healthy tuberculin-positive controls from Mexico and 701 TB cases and 796 controls from Peru. We also performed immunohistochemistry (IHC) analysis of lymph nodes from carriers of relevant two-locus genotypes and in vitro studies to determine how these variants may operate to increase the risk of developing active disease. We report that a joint effect between the – 2518 MCP-1 genotype GG and the – 1607 MMP-1 genotype 2G/2G consistently increases the odds of developing TB 3.59-fold in Mexicans and 3.9-fold in Peruvians. IHC analysis of lymph nodes indicated that carriers of the two-locus genotype MCP-1 GG MMP-1 2G/2G express the highest levels of both MCP-1 and MMP-1. Carriers of these susceptibility genotypes might be at increased risk of developing TB because they produce high levels of MCP-1, which enhances the induction of MMP-1 production by M. tuberculosis-sonicate antigens to higher levels than in carriers of the other two-locus MCP-1 MMP-1 genotypes studied. This notion was supported by in vitro experiments and luciferase based promoter activity assay. MMP-1 may destabilize granuloma formation and promote tissue damage and disease progression early in the infection. Our findings may foster the development of new and personalized therapeutic approaches targeting MCP-1 and/or MMP-1

    Prevalence of Peripheral Arterial Disease and Associated Vascular Risk Factors in 65-Years-Old People of Northern Barcelona

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    Asintomático; Factores de riesgo cardiovascular; PrevalenciaAsimptomàtic; Factors de risc cardiovascular; PrevalençaAsymptomatic; Cardiovascular risk factors; PrevalenceObjective: To determine the prevalence and risk factors associated with peripheral arterial disease (PAD) in Northern Barcelona at 65 years of age. Methods: A single-center, cross-sectional study, including males and females 65 years of age, health care cardholders of Barcelona Nord. PAD was defined as an ankle–brachial index (ABI) < 0.9. Attending subjects were evaluated for a history of common cardiovascular risk factors. A REGICOR score was obtained, as well as a physical examination and anthropometric measurements. Results: From November 2017 to December 2018, 1174 subjects were included: 479 (40.8%) female and 695 (59.2%) male. Overall prevalence of PAD was 6.2% (95% CI: 4.8–7.6%), being 7.9% (95% CI: 5.9–9.9%) in males and 3.8% (95% CI: 2.1–5.5%) in females. An independent strong association was seen in male smokers and diabetes, with ORs pf 7.2 (95% CI: 2.8–18.6) and 1.8 (95% CI: 1.0–3.3), respectively, and in female smokers and hypertension, with ORs of 5.2 (95% CI: 1.6–17.3) and 3.3 (95% CI: 1.2–9.0). Male subjects presented with higher REGICOR scores (p < 0.001). Conclusion: Higher-risk groups are seen in male subjects with a history of smoking and diabetes and female smokers and arterial hypertension, becoming important subgroups for our primary healthcare centers and should be considered for ABI screening programs.This work was logistically supported by the PERIS 2016–2020 medical research grant from Generalitat de Catalunya (Spain). Expedient Number SLT002/16/00441

    New species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus shows an ortholog of the E. canis major immunogenic glycoprotein gp36 with a new sequence of tandem repeats

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    Background: Ehrlichia species are the etiological agents of emerging and life-threatening tick-borne human zoonoses that inflict serious and fatal infections in companion animals and livestock. The aim of this paper was to phylogeneticaly characterise a new species of Ehrlichia isolated from Rhipicephalus (Boophilus) microplus from Minas Gerais, Brazil. Methods: The agent was isolated from the hemolymph of Rhipicephalus (B.) microplus engorged females that had been collected from naturally infested cattle in a farm in the state of Minas Gerais, Brazil. This agent was then established and cultured in IDE8 tick cells. The molecular and phylogenetic analysis was based on 16S rRNA, groEL, dsb, gltA and gp36 genes. We used the maximum likelihood method to construct the phylogenetic trees. Results: The phylogenetic trees based on 16S rRNA, groEL, dsb and gltA showed that the Ehrlichia spp isolated in this study falls in a clade separated from any previously reported Ehrlichia spp. The molecular analysis of the ortholog of gp36, the major immunoreactive glycoproteins in E. canis and ortholog of the E. chaffeensis gp47, showed a unique tandem repeat of 9 amino acids (VPAASGDAQ) when compared with those reported for E. canis, E. chaffeensis and the related mucin-like protein in E. ruminantium. Conclusions: Based on the molecular and phylogenetic analysis of the 16S rRNA, groEL, dsb and gltA genes we concluded that this tick-derived microorganism isolated in Brazil is a new species, named E. mineirensis (UFMG-EV), with predicted novel antigenic properties in the gp36 ortholog glycoprotein. Further studies on this new Ehrlichia spp should address questions about its transmissibility by ticks and its pathogenicity for mammalian hosts

    The AMS-RICH velocity and charge reconstruction

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    The AMS detector, to be installed on the International Space Station, includes a Ring Imaging Cerenkov detector with two different radiators, silica aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to provide very precise measurements of velocity and electric charge in a wide range of cosmic nuclei energies and atomic numbers. The detector geometry, in particular the presence of a reflector for acceptance purposes, leads to complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The results of different reconstruction methods applied to test beam data as well as to simulated samples are presented. To ensure nominal performances throughout the flight, several detector parameters have to be carefully monitored. The algorithms developed to fulfill these requirements are presented. The velocity and charge measurements provided by the RICH detector endow the AMS spectrometer with precise particle identification capabilities in a wide energy range. The expected performances on light isotope separation are discussed.Comment: Contribution to the ICRC07, Merida, Mexico (2007); Presenter: F. Bara

    The RICH detector of the AMS-02 experiment: status and physics prospects

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    The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV. It is equipped with several subsystems, one of which is a proximity focusing RICH detector with a dual radiator (aerogel+NaF) that provides reliable measurements for particle velocity and charge. The assembly and testing of the AMS RICH is currently being finished and the full AMS detector is expected to be ready by the end of 2008. The RICH detector of AMS-02 is presented. Physics prospects are briefly discussed.Comment: 5 pages. Contribution to the 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications (Como 2007). Presenter: Rui Pereir

    Textile waste reduction through fashion product design

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    O presente artigo traz reflexĂ”es sobre como o projeto de moda pode ser pensado com o viĂ©s da sustentabilidade ambiental, contemplando alguns conceitos e açÔes do setor tĂȘxtil e de confecção. Foi realizada uma simulação de produção de um modelo de blusa feminina levando em consideração os conceitos de redução de resĂ­duo na fonte por meio de modificaçÔes simples no produto. Desta forma, foram elaborados os desenhos, modelagens, encaixes e cĂĄlculos de tecidos e mĂŁo de obra para que fossem comparados os custos de produção e de geração de resĂ­duos tĂȘxteis em cada um dos modelos. Os resultados mostram que as modificaçÔes reduziram consideravelmente a quantidade de resĂ­duos na etapa de corte de tecidos, embora tenham acarretado no aumento dos custos com mĂŁo de obra.This article discusses some concepts and actions of the textile and clothing sectors. It was made a simulation for the production of a female blouse model taking into account the PmaisL concepts with intervention in the waste generation which include changes in the product. This way, the drawings, modeling, fabrics fittings and calculations and workmanship were elaborated to compare the production costs and textile waste generation in each of the models

    Maturity of the myenteric plexus is decreased in the gastroschisis rat model

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    Background: Amniotic fluid ( AF) and its components, such as fetal urine and meconium, may lead to intestinal alterations in gastroschisis, which cause immaturity of the myenteric plexus and consequent intestinal hypomotility and malabsorption. In this study we identified morphological and histological alterations of the intestine and the myenteric plexus with two different times of exposure to AF. Methods: The experimental gastroschisis was achieved at two different gestational ages, on day 18.5 ( E18.5) and day 19.5 (E19.5) of gestation, in fetal rats which were divided into 3 subgroups: control, sham and gastroschisis. We measured fetal body weight ( BW), intestinal weight ( IW) and intestinal length ( IL). The layers of intestinal wall and myenteric plexus were evaluated by hematoxylin and eosin staining ( HE staining) and immunofluorescence (alpha-internexin), respectively. Results: BW was not significantly different among the control, sham and gastroschisis groups at both ages. IW and IL were larger and shorter, respectively, in the gastroschisis fetuses (p<0.001) at both ages. Intestinal diameters and wall layers presented significant differences among control, sham and gastroschisis fetuses at both ages (p<0.001), but the time of exposure to AF compromised the serous membrane, D-II ( diameter II, p<0.001) and IL (p = 0.001). alpha-Internexin presented more intensive immunoreactivity in gastroschisis fetuses at E18.5. Conclusions: In gastroschisis, the longer the time of exposure to AF, the more severe bowel impairment will be, especially with regard to IL and the serous layer, and the more immature the myenteric plexus will be. Copyright (C) 2007 S. Karger AG, Basel.231606
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