718 research outputs found

    Classical Simulation of Quantum Fields II

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    We consider the classical time evolution of a real scalar field in 2 dimensional Minkowski space with a λϕ4\lambda \phi^4 interaction. We compute the spatial and temporal two-point correlation functions and extract the renormalized mass of the interacting theory. We find our results are consistent with the one- and two-loop quantum computation. We also perform Monte Carlo simulations of the quantum theory and conclude that the classical scheme is able to produce more accurate results with a fraction of the CPU time.Comment: 16 pages, 8 figures, now matches published versio

    Avaliação da depleção linfóide folicular da Bursa de Fabricius: uma metodologia alternativa utilizando análise digital de imagem e redes neurais artificiais

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    Fifty Bursa of Fabricius (BF) were examined by conventional optical microscopy and digital images were acquired and processed using Matlab® 6.5 software. The Artificial Neuronal Network (ANN) was generated using Neuroshell® Classifier software and the optical and digital data were compared. The ANN was able to make a comparable classification of digital and optical scores. The use of ANN was able to classify correctly the majority of the follicles, reaching sensibility and specificity of 89% and 96%, respectively. When the follicles were scored and grouped in a binary fashion the sensibility increased to 90% and obtained the maximum value for the specificity of 92%. These results demonstrate that the use of digital image analysis and ANN is a useful tool for the pathological classification of the BF lymphoid depletion. In addition it provides objective results that allow measuring the dimension of the error in the diagnosis and classification therefore making comparison between databases feasible.Cinquenta Bursa de Fabrícius (BF) foram examinadas através de microscopia óptica convencional e imagens digitais foram obtidas e processadas através do software Matlab® 6.5. Redes Neurais Artificiais (ANN) foram geradas com a utilização do software Neuroshell® Classifier, e os dados das análises óptica e digital foram comparados. A ANN classificou corretamente a maioria dos folículos, atingindo sensibilidade e especificidade de 89% e 96%, respectivamente. Quando os folículos foram agrupados de forma binária houve um aumento da sensibilidade para 90% e obteve-se um valor máximo para a especificidade de 92%. Estes resultados demonstram que o uso da análise digital de imagem associada à ANNé uma ferramenta bastante útil para a classificação patológica da depleção linfóide da BF. Além disso, fornece resultados objetivos que permitem medir a dimensão do erro classificatório, tornando possível a comparação entre distintos bancos de dados

    Etude de l’effet d’une source d’inoculum externe sur la propagation du CABMV (Cowpea aphid – borne mosaic virus) selon la proximité des parcelles voisines et la variété de niébé

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    Un champ ensemencé avec des semences de qualité peut se retrouver voisin avec un autre ensemencé avec des semences infectées par le virus de la mosaïque du niébé. Ce virus est transmis par les semences à des taux de 0 à 40% selon les variétés. Ces semences infectées donnent des jeunes plantes virosées à partir desquelles les pucerons vont propager la maladie. Ce travail a été effectué pour déterminer la distance minimale permettant d’éviter des contaminations à partir d’inoculum externe suivant la sensibilité de la variété. Ainsi, deux parcelles centrales de 300 m2 ont été semées avec des graines de Gorom local contaminées à 0,5% par le virus. Autour de la première parcelle centrale, 4 parcelles de 200 m2 chacune ont été semées avec des graines de Gorom local indemnes de virus aux distances respectives de 10 m, 15 m, 20 m et 25 m. Autour de la deuxième parcelle centrale, des semences indemnes de virus de Kvx61-1 ont été utilisées. Un dispositif similaire a été constitué pour les parcelles témoins avec des semences indemnes de virus. La propagation de la maladie a montré qu’elle est liée à la variété, aux pucerons et à la distance avec la source d’inoculum.© 2015 International Formulae Group. All rights reserved.Mots clés: Semences indemnes de virus, semences contaminées, distance minimale, puceronsEnglish Title: Study of the effect of external inoculum source on CABMV (Cowpea aphid – borne mosaic virus) spread in relation to the proximity of neighboring plots and the cowpea varietyEnglish AbstractA field sown with quality seeds can be closed to another one sown with seeds infected by cowpea mosaic virus which is seed transmitted at rates ranging from 0 to 40% depending on cowpea varieties. Infected seeds germinate and grow into virus-infected seedlings from which aphids will spread the disease. This  research was carried out in order to determine the minimum distance needed for avoiding contaminations from external virus inoculum sources, in relation with the susceptibility of cowpea varieties. Thus, two central plots of 300 m² have been sown with contaminated seeds at 0.5% by CABMV of cowpea variety Gorom local. Around the first central plot, four plots of 200 m² each were sown with virus-free seeds of Gorom local at respective distances of 10 m, 15 m, 20 m and 25 m. Around the second central plot, virus-free seeds of Kvx61- 1 have been used. A similar layout was done for the control plots with virus-free seeds. It was found that the spread of the disease was related to the cowpea variety, the aphids and the distance from the inoculum source.© 2015 International Formulae Group. All rights reserved.Keywords: Virus-free seeds, contaminated seeds, minimum distance, aphid

    Platelet FcγRIIA-induced serotonin release exacerbates the severity of Transfusion-Related Acute Lung Injury in mice

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    Transfusion-related acute lung injury (TRALI) remains a major cause of transfusion-related fatalities. The mechanism of human antibody-mediated TRALI, especially the involvement of the Fcγ receptors, is not clearly established. Contrary to mice, human platelets are unique in their expression of the FcγRIIA/CD32A receptor, suggesting that our understanding of the pathogenesis of antibody-mediated TRALI is partial, as the current murine models incompletely recapitulate the human immunology. We evaluated the role of FcγRIIA/CD32A in TRALI using a humanized mouse model expressing the FcγRIIA/CD32A receptor. When challenged with a recombinant chimeric human immunoglobulin G1/mouse anti–major histocompatibility complex class I monoclonal antibody, these mice exhibited exacerbated alveolar edema and higher mortality compared with wild-type (WT) mice. Unlike in WT mice, monocytes/macrophages in CD32A(+) mice were accessory for TRALI initiation, indicating the decisive contribution of another cell type. Platelet activation was dramatically increased in CD32A(+) animals, resulting in their increased consumption and massive release of their granule contents. Platelet depletion prevented the exacerbation of TRALI in CD32A(+) mice but did not affect TRALI in WT animals. By blocking platelet serotonin uptake with fluoxetine, we showed that the severity of TRALI in CD32A(+) mice resulted from the serotonin released by the activated platelets. Furthermore, inhibition of 5-hydroxytryptamine 2A serotonin receptor with sarpogrelate, before or after the induction of TRALI, abolished the aggravation of lung edema in CD32A(+) mice. Our findings show that platelet FcγRIIA/CD32A activation exacerbates antibody-mediated TRALI and provide a rationale for designing prophylactic and therapeutic strategies targeting the serotonin pathway to attenuate TRALI in patients

    Vital and functional outcomes of the first-ever hemispheric stroke, epidemiological comparative study between Kunming (China) and Limoges (France)

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    AbstractBackgroundClinical outcomes and socioeconomic consequences after a stroke may differ between regions.MethodsOne cohort was established prospectively in Kunming (China) to compare with a cohort of 156 stroke patients included in Limoges (France). During 1 year, patients hospitalized within 48hours for a first-ever hemispheric stroke were included. Demographic data and neurocardiovascular risk factors were registered. Hemiplegia was evaluated. Functional outcome was assessed using the Barthel Index (BI) after 3 months.ResultsOne hundred and eighteen patients were included in Kunming. Patients of Kunming were younger (61.4±13.4 vs 72.3±14.6 years in Limoges, P<0.0001), more involved in professional activity (36.4% vs 12.8%, P<0.0001). Survival analysis indicated that mortality did not differ between cohorts, but independently predicted by coma at the 2nd day (HR=9.33, 95% CI [4.39, 19.78]) and age>70 years (HR=6.29, 95% CI [2.36, 16.59]). Despite a better baseline BI for patients of Kunming (50.0±34.9 vs 37.4±34.2, P=0.0031), after adjustment for confusing, patients in Limoges had a 2.11 OR 95% CI [1.03, 4.31]) to reach a BI>80 at 3 months.ConclusionsFunctional recovery for patients of Kunming was not as good as expected. The socioeconomic consequences of stroke in Kunming are significant as they involved younger subjects who were still in work

    Exercise-Induced Interleukin-6 and Metabolic Responses in Hot, Temperate, and Cold Conditions

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    The purpose of this study was to determine the effects of exercise in hot, cold, and temperate environments on plasma interleukin-6 (IL-6). Eleven recreationally trained males (age = 25 ± 4 years, height = 178 ± 5 cm, weight = 79.4 ± 13.5 kg, body fat = 14.7 ± 3.6%, VO2 peak = 54.6 ± 11.5 ml kg-1 min-1) performed a 1 hr cycling bout in hot (33 °C), cold (7 °C), and temperate (20 °C) environments at 60% of Wmax followed by 3 hr of supine recovery in temperate conditions. Expired gases were measured every 15 min during exercise and once every hour during recovery. Heart rate was continuously measured throughout the trials. Blood samples were obtained from the antecubital vein pre-exercise, immediately post-exercise, and 3 hr post-exercise. Blood samples were analyzed for plasma concentrations of IL-6 using a commercial ELISA kit. Plasma IL-6 concentrations were significantly higher immediately post-exercise (14.8 ± 1.6 pg ml-1, p = 0.008) and 3 hr post-exercise (14.8 ± 0.9 pg ml-1, p = 0.018) compared to pre-exercise (11.4 ± 2.4 pg ml-1), across all trials. There were no differences in plasma IL-6 concentrations (p = 0.207) between temperature conditions.Oxygen consumption and heart rate were higher and respiratory exchange ratio was lower in the hot compared to other conditions (p \u3c 0.05). These data indicate that the temperature in which exercise occurs does not affect acute plasma IL-6 response despite differences in metabolic state

    The ATP-gated P2X1 ion channel contributes to the severity of antibody-mediated Transfusion-Related Acute Lung Injury in mice

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    The biological responses that control the development of Transfusion-Related Acute Lung Injury (TRALI), a serious post-transfusion respiratory syndrome, still need to be clarified. Since extracellular nucleotides and their P2 receptors participate in inflammatory processes as well as in cellular responses to stress, we investigated the role of the ATP-gated P2X1 cation channel in antibody-mediated TRALI. The effects of NF449, a selective P2X1 receptor (P2RX1) antagonist, were analyzed in a mouse two-hit model of TRALI. Mice were primed with lipopolysaccharide (LPS) and 24 h later challenged by administrating an anti-MHC I antibody. The selective P2RX1 antagonist NF449 was administrated before the administration of LPS and/or the anti-MHC I antibody. When given before antibody administration, NF449 improved survival while maximal protection was achieved when NF449 was also administrated before the sensitization step. Under this later condition, protein contents in bronchoalveolar lavages were dramatically reduced. Cell depletion experiments indicated that monocytes/macrophages, but not neutrophils, contribute to this effect. In addition, the reduced lung periarteriolar interstitial edemas in NF449-treated mice suggested that P2RX1 from arteriolar smooth muscle cells could represent a target of NF449. Accordingly, inhibition of TRPC6, another cation channel expressed by smooth muscle cells, also reduced TRALI-associated pulmonary interstitial and alveolar edemas. These data strongly suggest that cation channels like P2RX1 or TRPC6 participate to TRALI pathological responses

    Determining the best sectioning method and intestinal segment for morphometric analysis in broilers

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    Brazilian poultry production is very efficient and demands maximum broiler performance. Therefore, digestive system pathologies have a relevant role. Considering it is difficult to obtain consistent information on intestinal morphometric analysis, this study aimed at establishing essential and clear criteria for the collection of intestinal segments for morphometric analysis. Fifteen 13-d-old broilers were sacrificed and three intestinal segments were collected per bird. Two 3-cm long sections were obtained from each of the intestinal segments. Samples were collected open or closed. The closed samples were transversely, hemicylindrically, or longitudinally sectioned. Samples were processed and stained with hematoxylin and eosin. The number of microscopic fields in each section was counted. Villi presenting the base clearly embedded in the submucosa, no damage or folds, and simple columnar epithelium at the tip were considered adequate for measurements. These villi were counted in each sample. The results shows that hemicylindrical sections presented the highest number of observation fields, with an average of 9.76 fields. Jejunum samples were among the three highest average villi counts, with 18.23 in longitudinal sections and 15.61 in hemicylindrical sections. The results of the present study indicate that hemicylindrical sectioning and jejunal samples were, respectively, the best sectioning method and the best intestinal segment for the morphometric analysis of the intestines of broilers
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