6,731 research outputs found

    Detecting the traders' strategies in Minority-Majority games and real stock-prices

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    Price dynamics is analyzed in terms of a model which includes the possibility of effective forces due to trend followers or trend adverse strategies. The method is tested on the data of a minority-majority model and indeed it is capable of reconstructing the prevailing traders' strategies in a given time interval. Then we also analyze real (NYSE) stock-prices dynamics and it is possible to derive an indication for the the ``sentiment'' of the market for time intervals of at least one day.Comment: 13 pages, 10 figure

    Ankylosing Spondylitis: a trade Off of HLA-B27, ERAP, and pathogen interconnections? Focus on Sardinia

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    The frequency of HLA-B27 in patients with Ankylosing Spondylitis (AS) is over 85%. There are more than 170 recognized HLA-B27 alleles but the majority of them is not sufficiently represented for genetic association studies. So far only two alleles, the HLA-B*2706 in Asia and the HLA-B*2709 in Sardinia, have not been found to be associated with AS. The highly homogenous genetic structure of the Sardinian population has favored the search of relevant variants for disease-association studies. Moreover, malaria, once endemic in the island, has been shown to have contributed to shape the native population genome affecting the relative allele frequency of relevant genes. In Sardinia, the prevalence of HLA-B*2709, which differs from the strongly AS-associated B*2705 prototype for one amino acid (His/Asp116) in the F pocket of the peptide binding groove, is around 20% of all HLA-B27 alleles. We have previously hypothesized that malaria could have contributed to the establishment of this allele in Sardinia. Based on our recent findings, in this perspective article we speculate that the Endoplasmic Reticulum Amino Peptidases, ERAP1 and 2, associated with AS and involved in antigen presentation, underwent co-selection by malaria. These genes, besides shaping the immunopeptidome of HLA-class I molecules, have other biological functions that could also be involved in the immunosurveillance against malaria

    An allelic variant in the intergenic region between ERAP1 and ERAP2 correlates with an inverse expression of the two genes

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    The Endoplasmatic Reticulum Aminopeptidases ERAP1 and ERAP2 are implicated in a variety of immune and non-immune functions. Most studies however have focused on their role in shaping the HLA class I peptidome by trimming peptides to the optimal size. Genome Wide Association Studies highlighted non-synonymous polymorphisms in their coding regions as associated with several immune mediated diseases. The two genes lie contiguous and oppositely oriented on the 5q15 chromosomal region. Very little is known about the transcriptional regulation and the quantitative variations of these enzymes. Here, we correlated the level of transcripts and proteins of the two aminopeptidases in B-lymphoblastoid cell lines from 44 donors harbouring allelic variants in the intergenic region between ERAP1 and ERAP2. We found that the presence of a G instead of an A at SNP rs75862629 in the ERAP2 gene promoter strongly influences the expression of the two ERAPs with a down-modulation of ERAP2 coupled with a significant higher expression of ERAP1. We therefore show here for the first time a coordinated quantitative regulation of the two ERAP genes, which can be relevant for the setting of specific therapeutic approaches

    Port Authorities as cluster managers: the case of the Ligurian ports

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    The paper analyses the role of Port Authorities as cluster managers able to generate resources for investments with benefits for the intermodal transport chain as a whole. Assessment is made of Port Authority initiatives to foster the development of intermodality and the creation of dry ports. The framework proposed is then applied to the case of the Ligurian ports, which compete less as individual structures than as nodal points within integrated logistic chains. We argue that the integration of the land logistic interface may prove beneficial to the Ligurian ports, and that this can be achieved only if the Port Authorities act as cluster managers

    Generalized minority games with adaptive trend-followers and contrarians

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    We introduce a simple extension of the minority game in which the market rewards contrarian (resp. trend-following) strategies when it is far from (resp. close to) efficiency. The model displays a smooth crossover from a regime where contrarians dominate to one where trend-followers dominate. In the intermediate phase, the stationary state is characterized by non-Gaussian features as well as by the formation of sustained trends and bubbles.Comment: 4 pages, 6 figure

    Human-technology integration with industrial conversational agents: A conceptual architecture and a taxonomy for manufacturing

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    Conversational agents are systems with great potential to enhance human-computer interaction in industrial settings. Although the number of applications of conversational agents in many fields is growing, there is no shared view of the elements to design and implement for chatbots in the industrial field. The paper presents the combination of many research contributions into an integrated conceptual architecture, for developing industrial conversational agents using Nickerson's methodology. The conceptual architecture consists of five core modules; every module consists of specific elements and approaches. Furthermore, the paper defines a taxonomy from the study of empirical applications of manufacturing conversational agents. Indeed, some applications of chatbots in manufacturing are available but those have never been collected in single research. The paper fills this gap by analyzing the empirical cases and presenting a qualitative analysis, with verification of the proposed taxonomy. The contribution of the article is mainly to illustrate the elements needed for the development of a conversational agent in manufacturing: researchers and practitioners can use the proposed conceptual architecture and taxonomy to more easily investigate, define, and develop all the elements for chatbot implementation

    Strangers and Foreigners: Trust and Attitudes toward Citizenship

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    We analyze the relationship between natives' attitudes towards citizenship acquisition for foreigners and trust. Our hypothesis is that, in sub-Saharan Africa, the slave trade represents the deep factor behind contemporary attitudes toward citi zenship, with more intense exposure to historical slave exports for an individual's ethnic group being associated with contemporary distrust for strangers, and in turn opposition to citizenship laws that favor the inclusion of foreigners. We nd that individuals who are more trusting do show more positive attitudes towards the acquisition of citizenship at birth for children of foreigners, that these attitudes are also negatively related to the intensity of the slave trade, and that the underlying link between trust and the slave trade is confirmed. Alternative factors - conflict,, kinship, and witchcraft beliefs- that, through trust, may affect attitudes toward citizenship, are not generating the same distinctive pattern of linkages emerging from the slave trade

    Strangers and Foreigners: Trust and Attitudes toward Citizenship

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    We analyze the relationship between natives’ attitudes towards citizenship acquisition for foreigners and trust. Our hypothesis is that, in sub-Saharan Africa, the slave trade represents the deep factor behind contemporary attitudes toward citizenship, with more intense exposure to historical slave exports for an individual’s ethnic group being associated with contemporary distrust for strangers, and in turn opposition to citizenship laws that favor the inclusion of foreigners. We find that individuals who are more trusting do show more positive attitudes towards the acquisition of citizenship at birth for children of foreigners, that these attitudes are also negatively related to the intensity of the slave trade, and that the underlying link between trust and the slave trade is confirmed. Alternative factors—conflict, kinship, and witchcraft beliefs—that, through trust, may affect attitudes toward citizenship, are not generating the same distinctive pattern of linkages emerging from the slave trade

    Expression analysis of HLA-E and NKG2A and NKG2C receptors points at a role for natural killer function in ankylosing spondylitis

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    Background. Ankylosing Spondylitis (AS) is a complex chronic inflammatory disease strongly associated with the majority of HLA-B27 alleles. HLA-E are non-classical MHC class I molecules that specifically interact with the natural killer receptors NKG2A (inhibitory) and NKG2C (activating), and have been recently proposed to be involved in AS pathogenesis. Objectives: To analyze the expression of HLA-E and the CD94/NKG2 pair of receptors in HLA-B27 positive AS patients and healthy controls (HC) bearing the AS-associated, B*2705 and the non-AS-associated, B*2709 allele. Methods: The level of surface expression of HLA-E molecules on CD14 positive peripheral blood mononuclear cell was evaluated in 21 HLA-B*2705 patients with AS, 12 HLA-B*2705 HC, 12 HLA-B*2709 HC and 6 HLA-B27 negative HC, using the monoclonal antibody MEM-E/08 by quantitative cytofluorimetric analysis. The percentage and density of expression of HLA-E ligands NKG2A and NKG2C were also measured on CD3-CD56+ NK cells. Results. HLA-E expression in CD14 positive cells was significantly higher in AS patients (587.0 IQR 424-830) compared to B*2705 HC (389 IQR 251.3-440.5, p=0.0007), B*2709 HC (294.5 IQR 209.5-422, p=0.0004) and HLA-B27 negative HC (380 IQR 197.3-515.0, p=0.01). A higher number of NK cells expressing NKG2A compared to NKG2C was found in all cohort analysed as well as a higher cell surface density. Conclusion: The higher surface level of HLA-E molecules in AS patients compared to HC, concurrently with a prevalent expression of NKG2A, suggests that the crosstalk between these two molecules might play a role in AS pathogenesis accounting for the previously reported association between HLA-E and AS
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