47 research outputs found

    Common priors under endogenous uncertainty

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    For a fixed game and a type structure that admits a common prior, Action Independence states that the conditional beliefs induced by the common prior do not depend on the players' own strategies. It has been conjectured that Action Independence can be behaviorally characterized by means of a suitable no-betting condition (Dekel and Siniscalchi, 2015), but whether this is indeed the case remains an open problem. In this paper, we prove this conjecture true by focusing on strategy-invariant bets, which are bets that cannot be manipulated by the players. In particular, first, we show that at least one of the common priors satisfies Action Independence if and only if there exists no mutually acceptable strategy-invariant bet among the players. Second, we show that, all common priors satisfy Action Independence if and only if there exists no mutually acceptable strategy-invariant bet among the players and an outside observer. These results give us a deeper understanding of existing foundations of solution concepts using only epistemic conditions that are expressed in terms of type structures and are therefore elicitable

    Thoracic trident pigmentation in Drosophila melanogaster: Differentiation of geographical populations

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    A phenotypic classification of trident pigmentation allowed the characterization ol any natural population by a pigmentation score, ranging from 0 to 3. After some training, independent observers could produce very similar score values. Growth temperature influences pigmentation intensity and the response curves exhibit a U-shape, with a minimum at about 25 "C. For the description of natural populations, 2 different growth temperatures, 17 °C and 25 °C were chosen. Crosses between a dark French strain and a light Afrotropical strain produced intermediate offspring, but a clear maternal effect differentiated the reciprocal Fl’s. Numerous populations from various part of the world were investigated and results arranged according to the latitude. For temperate populations collected between 34 and 48 ° of latitude a steep cline was observed (pigmentation being much more darker in high latitude) suggesting an adaptive pressure on this phenotype: environmental factors which may explain this cline being temperature, insolation and desiccation. In tropical populations on the other hand a large variability was observed but without any relation to latitude

    Urinary Transforming Growth Factor-beta 1 as a marker of response to immunosuppressive treatment, in patients with crescentic nephritis

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    BACKGROUND: Crescentic nephritis is characterized by formation of cellular crescents that soon become fibrotic and result in irreversible damage, unless an effective immunosuppressive therapy is rapidly commenced. TGF-β(1 )is involved in the development of crescents through various pathways. The aim of this study was to identify whether the determination of urinary TGF-β(1 )levels in patients with crescentic nephritis could be used as a marker of response to treatment. METHODS: Fifteen patients with crescentic nephritis were included in the study. The renal expression of TGF-β(1 )was estimated in biopsy sections by immunohistochemistry and urinary TGF-β(1 )levels were determined by quantitative sandwich enzyme immunoassay (EIA). TGF-β(1 )levels were determined at the time of renal biopsy, before the initiation of immunosuppressive treatment (corticosteroids, cyclophosphamide and plasma exchange). Twelve patients with other types of proliferative glomerulonephritis and ten healthy subjects were used as controls. RESULTS: Improvement of renal function with immunosuppressive therapy was observed in 6 and stabilization in 4 patients (serum creatinine from 3.2 ± 1.5 to 1.4 ± 0.1 mg/dl and from 4.4 ± 1.2 to 4.1 ± 0.6 mg/dl, respectively). In 5 patients, with severe impairment of renal function who started on dialysis, no improvement was noted. The main histological feature differentiating these 5 patients from others with improved or stabilized renal function was the percentage patients with poor response to treatment were the percentage of glomeruli with crescents and the presence of ruptured Bowman's capsule and glomerular necrosis. Urinary TGF-β(1 )levels were significantly higher in patients who showed no improvement of renal function with immunosuppressive therapy (930 ± 126 ng/24 h vs. 376 ± 84 ng/24 h, p < 0.01). TGF-β(1 )was identified in crescents and tubular epithelial cells, whereas a significant correlation of TGF-β(1 )immunostaining with the presence of fibrocellular cresents was observed (r = 0.531, p < 0,05). CONCLUSION: Increased TGF-β(1 )renal expression and urinary excretion that is related to the response to immunosuppressive therapy was observed in patients with crescentic nephritis. Evaluation of urinary TGF-β(1 )levels may be proved a useful marker of clinical outcome in patients with crescentic nephritis

    Reciprocal Tripartite Interactions between the Aedes aegypti Midgut Microbiota, Innate Immune System and Dengue Virus Influences Vector Competence

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    Dengue virus is one of the most important arboviral pathogens and the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It is transmitted between humans by the mosquitoes Aedes aegypti and Aedes albopictus, and at least 2.5 billion people are at daily risk of infection. During their lifecycle, mosquitoes are exposed to a variety of microbes, some of which are needed for their successful development into adulthood. However, recent studies have suggested that the adult mosquito's midgut microflora is critical in influencing the transmission of human pathogens. In this study we assessed the reciprocal interactions between the mosquito's midgut microbiota and dengue virus infection that are, to a large extent, mediated by the mosquito's innate immune system. We observed a marked decrease in susceptibility to dengue virus infection when mosquitoes harbored certain field-derived bacterial isolates in their midgut. Transcript abundance analysis of selected antimicrobial peptide genes suggested that the mosquito's microbiota elicits a basal immune activity that appears to act against dengue virus infection. Conversely, the elicitation of the mosquito immune response by dengue virus infection itself influences the microbial load of the mosquito midgut. In sum, we show that the mosquito's microbiota influences dengue virus infection of the mosquito, which in turn activates its antibacterial responses

    Proteases of haematophagous arthropod vectors are involved in blood-feeding, yolk formation and immunity : a review

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    Ticks, triatomines, mosquitoes and sand flies comprise a large number of haematophagous arthropods considered vectors of human infectious diseases. While consuming blood to obtain the nutrients necessary to carry on life functions, these insects can transmit pathogenic microorganisms to the vertebrate host. Among the molecules related to the blood-feeding habit, proteases play an essential role. In this review, we provide a panorama of proteases from arthropod vectors involved in haematophagy, in digestion, in egg development and in immunity. As these molecules act in central biological processes, proteases from haematophagous vectors of infectious diseases may influence vector competence to transmit pathogens to their prey, and thus could be valuable targets for vectorial control

    Proteases of haematophagous arthropod vectors are involved in blood-feeding, yolk formation and immunity - a review

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    Urinary interleukin-6 (IL-6) and transforming growth factor (TGF-β) levels in corticosteroidtreated patients with IgA nephropathy

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    Background: Interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) are implicated in the progression of IgA nephropathy, which is usually treated with corticosteroids. Patients and methods: Urinary IL-6 and TGF-β were measured in 21 proteinuric patients with IgA nephropathy, before and after treatment with corticosteroids, to estimate the activity of the disease after remission of proteinuria. Results: Urinary IL-6 and TGF-β levels at diagnosis were significantly higher in patients with IgA nephropathy compared to healthy subjects. TGF-β levels, were significantly higher in patients with proteinuria &gt; 1 g/24 h and/or severe mesangial proliferation. Although a significant reduction of proteinuria was observed with corticosteroid treatment, urinary IL-6 and TGF-β levels remained elevated. Deterioration of renal function over a period of 5 years was observed in 3 patients. High urinary IL-6 levels at diagnosis represent a significant parameter distinguishing patients with progressive course in comparison to those with favorable clinical outcome (p = 0.01). Conclusion: Treatment of patients with IgA nephropathy with corticosteroids is followed by remission of proteinuria but still increased urinary IL-6 and TGF-β excretion. This may be related to an ongoing inflammatory process within the kidney, and further research is required to estimate the value of urinary IL-6 and TGF-β as markers of activity of the disease. © 2011 Dustri-Verlag Dr. K. Feistle
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