979 resultados para systemic multi-contextual mode


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Schistosoma mansoni infection induces in their hosts a marked and sustained eosinophilia, which is influenced or modulated by complex mechanisms, that vary according to the phase of infection. To address this phenomenon, we used the air pouch (AP) model in control and infected Swiss webster mice, analyzing the cellular, tissue response and local expression of adhesion molecules [CD18 (beta 2-chain), CD44, ICAM-1 (CD54), L-selectin (CD62L), CD49d (alpha 4-chain), LFA1 (CD11a)]. Infected animals were studied at 3 (pre-oviposition phase), 7 (acute phase), and 14 (chronic phase) weeks after infection (5-6 mice/period of infection). Normal mice were age-matched. Results showed that after egg stimulation, compared with matched controls, the infected mice, at each point of infection, showed a lower eosinophil response in the acute (7 weeks) and chronic phase (14 weeks) of infection. However, when the infected mice were in pre-oviposition phase (3 weeks) their eosinophil response surpassed the control ones. In the AP wall of infected mice, a significant decrease in the expression of ICAM-1 and CD44 in fibroblastic-like cells and a reduction in the number of CD18 and CD11a in migratory cells were observed. The other adhesion molecules were negative or weakly expressed. The results indicated that in the air pouch model, in S. mansoni-infected mice: (1) eosinophil response is strikingly down-regulated, during the acute ovular phase; (2) in the pre-oviposition phase, in contrast, it occurs an up-regulatory modulation of eosinophil response, in which the mechanisms are completely unknown; (3) in the chronic phase of the infection, the down modulation of eosinophil response is less pronounced; 4) Down-regulation of adhesion molecules, specially of ICAM-1 appear to be associated with the lower eosinophil response.

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This paper presents the Juste-Neige system for predicting the snow height on the ski runs of a resort using a multi-agent simulation software. Its aim is to facilitate snow cover management in order to i) reduce the production cost of artificial snow and to improve the profit margin for the companies managing the ski resorts; and ii) to reduce the water and energy consumption, and thus to reduce the environmental impact, by producing only the snow needed for a good skiing experience. The software provides maps with the predicted snow heights for up to 13 days. On these maps, the areas most exposed to snow erosion are highlighted. The software proceeds in three steps: i) interpolation of snow height measurements with a neural network; ii) local meteorological forecasts for every ski resort; iii) simulation of the impact caused by skiers using a multi-agent system. The software has been evaluated in the Swiss ski resort of Verbier and provides useful predictions.

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Depuis quelques années, la spectrométrie de masse en tandem (MS/MS) ne cesse de gagner du terrain comme méthode d'analyse en toxicologie forensique, notamment pour le dosage des cannabinoïdes. Couplée à la chromatographie liquide (LC) ou gazeuse (GC), elle permet l'identification fiable et le dosage rapide du THC, de son précurseur acide, et de ses principaux métabolites, y compris les glucuronides. Au cours de ces dix dernières années, un nombre significatif de publications sont parues sur ce sujet. L'objectif de cet article est de passer en revue les analyses par spectrométrie de masse en tandem des cannabinoïdes dans diverses matrices biologiques. In recent years, tandem mass spectrometry (MS/MS) is gaining ground as a reference method of analysis in clinical and forensic toxicology, especially for the determination of cannabinoids. Coupled to liquid chromatography (LC) or gas chromatography (GC), it allows the definitive identification and rapid determination of THC, its acid precursor, and its major metabolites, including the glucuronides. During the past decade, several methods of analysis of cannabinoids in different matrices have appeared on this subject. The aim of this paper is to review the analysis of cannabinoids by tandem mass spectrometry methods in various biological matrices

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A total of 116 isolates from patients attending the out-patient department at the All India Institute of Medical Sciences, New Delhi and the New Delhi Tuberculosis Centre, New Delhi, India were collected. They were analyzed for resistance to drugs prescribed in the treatment for tuberculosis. The drug resistance was initially determined by microbiological techniques. The Bactec 460TB system was employed to determine the type and level of resistance in each isolate. The isolates were further characterized at molecular level. The multi-drug loci corresponding to rpo b, gyr A, kat G were studied for mutation(s) by the polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) technique. The SSCP positive samples were sequenced to characterize the mutations in rpo b, and gyr A loci. While previously reported mutations in the gyr A and rpo b loci were found to be present, several novel mutations were also scored in the rpo b locus. Interestingly, analysis of the gyr A locus showed the presence of point mutation(s) that could not be detected by PCR-SSCP. Furthermore, rifampicin resistance was found to be an important marker for checking multi-drug resistance (MDR) in clinical isolates of Mycobacterium tuberculosis. This is the first report on molecular genetic analysis of MDR tuberculosis one from India, highlights the increasing incidence of MDR in the Indian isolates of M. tuberculosis.

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PURPOSE: This randomized phase II trial evaluated two docetaxel-based regimens to see which would be most promising according to overall response rate (ORR) for comparison in a phase III trial with epirubicin-cisplatin-fluorouracil (ECF) as first-line advanced gastric cancer therapy. PATIENTS AND METHODS: Chemotherapy-naïve patients with measurable unresectable and/or metastatic gastric carcinoma, a performance status <or= 1, and adequate hematologic, hepatic, and renal function randomly received <or= eight 3-weekly cycles of ECF (epirubicin 50 mg/m(2) on day 1, cisplatin 60 mg/m(2) on day 1, and fluorouracil [FU] 200 mg/m(2)/d on days 1 to 21), TC (docetaxel initially 85 mg/m(2) on day 1 [later reduced to 75 mg/m(2) as a result of toxicity] and cisplatin 75 mg/m(2) on day 1), or TCF (TC plus FU 300 mg/m(2)/d on days 1 to 14). Study objectives included response (primary), survival, toxicity, and quality of life (QOL). RESULTS: ORR was 25.0% (95% CI, 13% to 41%) for ECF, 18.5% (95% CI, 9% to 34%) for TC, and 36.6% (95% CI, 23% to 53%) for TCF (n = 119). Median overall survival times were 8.3, 11.0, and 10.4 months for ECF, TC, and TCF, respectively. Toxicity was acceptable, with one toxic death (TC arm). Grade 3 or 4 neutropenia occurred in more treatment cycles with docetaxel (TC, 49%; TCF, 57%; ECF, 34%). Global health status/QOL substantially improved with ECF and remained similar to baseline with both docetaxel regimens. CONCLUSION: Time to response and ORR favor TCF over TC for further evaluation, particularly in the neoadjuvant setting. A trend towards increased myelosuppression and infectious complications with TCF versus TC or ECF was observed.

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This study aimed to investigate the influence of ankle osteoarthritis (AOA) treatments, i.e., ankle arthrodesis (AA) and total ankle replacement (TAR), on the kinematics of multi-segment foot and ankle complex during relatively long-distance gait. Forty-five subjects in four groups (AOA, AA, TAR, and control) were equipped with a wearable system consisting of inertial sensors installed on the tibia, calcaneus, and medial metatarsals. The subjects walked 50-m twice while the system measured the kinematic parameters of their multi-segment foot: the range of motion of joints between tibia, calcaneus, and medial metatarsals in three anatomical planes, and the peaks of angular velocity of these segments in the sagittal plane. These parameters were then compared among the four groups. It was observed that the range of motion and peak of angular velocities generally improved after TAR and were similar to the control subjects. However, unlike AOA and TAR, AA imposed impairments in the range of motion in the coronal plane for both the tibia-calcaneus and tibia-metatarsals joints. In general, the kinematic parameters showed significant correlation with established clinical scales (FFI and AOFAS), which shows their convergent validity. Based on the kinematic parameters of multi-segment foot during 50-m gait, this study showed significant improvements in foot mobility after TAR, but several significant impairments remained after AA.

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Circulating levels of adiponectin, a hormone produced predominantly by adipocytes, are highly heritable and are inversely associated with type 2 diabetes mellitus (T2D) and other metabolic traits. We conducted a meta-analysis of genome-wide association studies in 39,883 individuals of European ancestry to identify genes associated with metabolic disease. We identified 8 novel loci associated with adiponectin levels and confirmed 2 previously reported loci (P = 4.5×10(-8)-1.2×10(-43)). Using a novel method to combine data across ethnicities (N = 4,232 African Americans, N = 1,776 Asians, and N = 29,347 Europeans), we identified two additional novel loci. Expression analyses of 436 human adipocyte samples revealed that mRNA levels of 18 genes at candidate regions were associated with adiponectin concentrations after accounting for multiple testing (p<3×10(-4)). We next developed a multi-SNP genotypic risk score to test the association of adiponectin decreasing risk alleles on metabolic traits and diseases using consortia-level meta-analytic data. This risk score was associated with increased risk of T2D (p = 4.3×10(-3), n = 22,044), increased triglycerides (p = 2.6×10(-14), n = 93,440), increased waist-to-hip ratio (p = 1.8×10(-5), n = 77,167), increased glucose two hours post oral glucose tolerance testing (p = 4.4×10(-3), n = 15,234), increased fasting insulin (p = 0.015, n = 48,238), but with lower in HDL-cholesterol concentrations (p = 4.5×10(-13), n = 96,748) and decreased BMI (p = 1.4×10(-4), n = 121,335). These findings identify novel genetic determinants of adiponectin levels, which, taken together, influence risk of T2D and markers of insulin resistance.

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Solving multi-stage oligopoly models by backward induction can easily become a com- plex task when rms are multi-product and demands are derived from a nested logit frame- work. This paper shows that under the assumption that within-segment rm shares are equal across segments, the analytical expression for equilibrium pro ts can be substantially simpli ed. The size of the error arising when this condition does not hold perfectly is also computed. Through numerical examples, it is shown that the error is rather small in general. Therefore, using this assumption allows to gain analytical tractability in a class of models that has been used to approach relevant policy questions, such as for example rm entry in an industry or the relation between competition and location. The simplifying approach proposed in this paper is aimed at helping improving these type of models for reaching more accurate recommendations.

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Bacteria active against dipteran larvae (mosquitoes and black flies) include a wide variety of Bacillus thuringiensis and B. sphaericus strains, as well as isolates of Brevibacillus laterosporus and Clostridium bifermentans. All display different spectra and levels of activity correlated with the nature of the toxins, mainly produced during the sporulation process. This paper describes the structure and mode of action of the main mosquitocidal toxins, in relationship with their potential use in mosquito and/or black fly larvae control. Investigations with laboratory and field colonies of mosquitoes that have become highly resistant to the B. sphaericus Bin toxin have shown that several mechanisms of resistance are involved, some affecting the toxin/receptor binding step, others unknown.

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This article studies how product introduction decisions relate to profitability and uncertainty in the context of multi-product firms and product differentiation. These two features, common to many modern industries, have not received much attention in the literature as compared to the classical problem of firm entry, even if the determinants of firm and product entry are quite different. The theoretical predictions about the sign of the impact of uncertainty on product entry are not conclusive. Therefore, an econometric model relating firms’ product introduction decisions with profitability and profit uncertainty is proposed. Firm’s estimated profits are obtained from a structural model of product demand and supply, and uncertainty is proxied by profits’ variance. The empirical analysis is carried out using data on the Spanish car industry for the period 1990-2000. The results show a positive relationship between product introduction and profitability, and a negative one with respect to profit variability. Interestingly, the degree of uncertainty appears to be a driving force of entry stronger than profitability, suggesting that the product proliferation process in the Spanish car market may have been mainly a consequence of lower uncertainty rather than the result of having a more profitable market. Keywords: Product introduction, entry, uncertainty, multiproduct firms, automobile JEL codes: L11, L13

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Introduction: Systemic inflammation in sepsis is initiated by interactions between pathogen molecular motifs and specific host receptors, especially toll-like receptors (TLRs). Flagellin is the main flagellar protein of motile microorganisms and is the ligand of TLR5. The distribution of TLR5 and the actions of flagellin at the systemic level have not been established. Therefore, we determined TLR5 expression and the ability of flagellin to trigger prototypical innate immune responses and apoptosis in major organs from mice. Methods: Male Balb/C mice (n = 80) were injected intravenously with 1-5 mu g recombinant Salmonella flagellin. Plasma and organ samples were obtained after 0.5 to 6 h, for molecular investigations. The expression of TLR5, the activation state of nuclear factor kappa B (NF kappa B) and mitogen-activated protein kinases (MAPKs) [extracellular related kinase (ERK) and c-jun-NH2 terminal kinase (JNK)], the production of cytokines [tumor necrosis alpha (TNF alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), macrophage inhibitory protein-2 (MIP-2) and soluble triggering receptor expressed on myeloid cells (TREM-1)], and the apoptotic cleavage of caspase-3 and its substrate Poly(ADP-ribose) polymerase (PARP) were determined in lung, liver, gut and kidney at different time-points. The time-course of plasma cytokines was evaluated up to 6 h after flagellin. Results: TLR5 mRNA and protein were constitutively expressed in all organs. In these organs, flagellin elicited a robust activation of NF kappa B and MAPKs, and induced significant production of the different cytokines evaluated, with slight interorgan variations. Plasma TNF alpha, IL-6 and MIP-2 disclosed a transient peak, whereas IL-1 beta and soluble TREM-1 steadily increased over 6 h. Flagellin also triggered a marked cleavage of caspase-3 and PARP in the intestine, pointing to its ability to promote significant apoptosis in this organ. Conclusions: Bacterial flagellin elicits prototypical innate immune responses in mice, leading to the release of multiple pro-inflammatory cytokines in the lung, small intestine, liver and kidney, and also activates apoptotic signalling in the gut. Therefore, this bacterial protein may represent a critical mediator of systemic inflammation and intestinal barrier failure in sepsis due to flagellated micro-organisms