114 research outputs found

    RDF Querying

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    Reactive Web systems, Web services, and Web-based publish/ subscribe systems communicate events as XML messages, and in many cases require composite event detection: it is not sufficient to react to single event messages, but events have to be considered in relation to other events that are received over time. Emphasizing language design and formal semantics, we describe the rule-based query language XChangeEQ for detecting composite events. XChangeEQ is designed to completely cover and integrate the four complementary querying dimensions: event data, event composition, temporal relationships, and event accumulation. Semantics are provided as model and fixpoint theories; while this is an established approach for rule languages, it has not been applied for event queries before

    Dating Business Cycles in a Historical Perspective: Evidence for Switzerland

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    In this study we suggest a chronology of the classical business cycle in Switzerland. To this end we use two approaches: the approach of Artis et al. (2004) and an approach based on Markov-switching models (Hamilton, 1989). Our results show that similar conclusions can be reached by applying the two methodologies. Another result is that the chronology obtained displays high concordance with the chronology derived for the Euro Area by the CEPR Business Cycle Dating Committee. A further contribution of our study is that we determine the sensitivity of the chronology obtained with respect to a particular GDP vintage used. For this purpose we employ the real-time database that contains 53 vintages of GDP data starting from 1997Q4 until 2010Q4. The main result of this robustness exercise is that the chronology obtained is stable across different vintages, although some minor differences across vintages can be detected

    Stimulation of MAP kinase pathways after maternal IL-1β exposure induces fetal lung fluid absorption in guinea pigs

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    BACKGROUND: We tested the hypothesis that maternal interleukin-1β (IL-1β) pretreatment and induction of fetal cortisol synthesis activates MAP kinases and thereby affects lung fluid absorption in preterm guinea pigs. METHODS: IL-1β was administered subcutaneously daily to timed-pregnant guinea pigs for three days. Fetuses were obtained by abdominal hysterotomy and instilled with isosmolar 5% albumin into the lungs and lung fluid movement was measured over 1 h by mass balance. MAP kinase expression was measured by western blot. RESULTS: Lung fluid absorption was induced at 61 days (D) gestation and stimulated at 68D gestation by IL-1β. Maternal IL-1β pretreatment upregulated ERK and upstream MEK expression at both 61 and 68D gestation, albeit being much more pronounced at 61D gestation. U0126 instillation completely blocked IL-1β-induced lung fluid absorption as well as IL-1β-induced/stimulated ERK expression. Cortisol synthesis inhibition by metyrapone attenuated ERK expression and lung fluid absorption in IL-1β-pretreated fetal lungs. JNK expression after maternal IL-1β pretreatment remained unaffected at either gestation age. CONCLUSION: These data implicate the ERK MAP kinase pathway as being important for IL-1β induction/stimulation of lung fluid absorption in fetal guinea pigs

    Myocardial infarction stabilization by cell-based expression of controlled Vascular Endothelial Growth Factor levels

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    Vascular Endothelial Growth Factor (VEGF) can induce normal or aberrant angiogenesis depending on the amount secreted in the microenvironment around each cell. Towards a possible clinical translation, we developed a Fluorescence Activated Cell Sorting (FACS)‐based technique to rapidly purify transduced progenitors that homogeneously express a desired specific VEGF level from heterogeneous primary populations. Here, we sought to induce safe and functional angiogenesis in ischaemic myocardium by cell‐based expression of controlled VEGF levels. Human adipose stromal cells (ASC) were transduced with retroviral vectors and FACS purified to generate two populations producing similar total VEGF doses, but with different distributions: one with cells homogeneously producing a specific VEGF level (SPEC), and one with cells heterogeneously producing widespread VEGF levels (ALL), but with an average similar to that of the SPEC population. A total of 70 nude rats underwent myocardial infarction by coronary artery ligation and 2 weeks later VEGF‐expressing or control cells, or saline were injected at the infarction border. Four weeks later, ventricular ejection fraction was significantly worsened with all treatments except for SPEC cells. Further, only SPEC cells significantly increased the density of homogeneously normal and mature microvascular networks. This was accompanied by a positive remodelling effect, with significantly reduced fibrosis in the infarcted area. We conclude that controlled homogeneous VEGF delivery by FACS‐ purified transduced ASC is a promising strategy to achieve safe and functional angiogenesis in myocardial ischaemia

    Secretor Genotype (FUT2 gene) Is Strongly Associated with the Composition of Bifidobacteria in the Human Intestine

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    Intestinal microbiota plays an important role in human health, and its composition is determined by several factors, such as diet and host genotype. However, thus far it has remained unknown which host genes are determinants for the microbiota composition. We studied the diversity and abundance of dominant bacteria and bifidobacteria from the faecal samples of 71 healthy individuals. In this cohort, 14 were non-secretor individuals and the remainders were secretors. The secretor status is defined by the expression of the ABH and Lewis histo-blood group antigens in the intestinal mucus and other secretions. It is determined by fucosyltransferase 2 enzyme, encoded by the FUT2 gene. Non-functional enzyme resulting from a nonsense mutation in the FUT2 gene leads to the non-secretor phenotype. PCR-DGGE and qPCR methods were applied for the intestinal microbiota analysis. Principal component analysis of bifidobacterial DGGE profiles showed that the samples of non-secretor individuals formed a separate cluster within the secretor samples. Moreover, bifidobacterial diversity (p<0.0001), richness (p<0.0003), and abundance (p<0.05) were significantly reduced in the samples from the non-secretor individuals as compared with those from the secretor individuals. The non-secretor individuals lacked, or were rarely colonized by, several genotypes related to B. bifidum, B. adolescentis and B. catenulatum/pseudocatenulatum. In contrast to bifidobacteria, several bacterial genotypes were more common and the richness (p<0.04) of dominant bacteria as detected by PCR-DGGE was higher in the non-secretor individuals than in the secretor individuals. We showed that the diversity and composition of the human bifidobacterial population is strongly associated with the histo-blood group ABH secretor/non-secretor status, which consequently appears to be one of the host genetic determinants for the composition of the intestinal microbiota. This association can be explained by the difference between the secretor and non-secretor individuals in their expression of ABH and Lewis glycan epitopes in the mucosa

    The Nature of Financial and Real Business Cycles: The Great Moderation and Banking Sector Pro-Cyclicality

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    This paper takes a fresh look at the nature of financial and real business cycles in OECD countries using annual data series and shorter quarterly and monthly economic indicators. It first analyses the main characteristics of the cycle, including the length, amplitude, asymmetry and changes of these parameters during expansions and contractions. It then studies the degree of economic and financial cycle synchronisation between OECD countries but also of economic and financial variables within a given country, and gauges the extent to which cycle synchronisation changed over time. Finally, the paper provides some new evidence on the drivers of the great moderation and analyses the banking sector's pro-cyclicality by using aggregate and bank-level data. The main findings show that the amplitude of the real business cycle was becoming smaller during the great moderation, but asset price cycles were becoming more volatile. In part this was linked to developments in the banking sector which tended to accentuate pro-cyclical behaviour

    Expression of the blood-group-related glycosyltransferase B4galnt2 influences the intestinal microbiota in mice

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    Glycans on mucosal surfaces have an important role in host–microbe interactions. The locus encoding the blood-group-related glycosyltransferase β-1,4-N-acetylgalactosaminyltransferase 2 (B4galnt2) is subject to strong selective forces in natural house-mouse populations that contain a common allelic variant that confers loss of B4galnt2 gene expression in the gastrointestinal (GI) tract. We reasoned that altered glycan-dependent intestinal host–microbe interactions may underlie these signatures of selection. To determine whether B4galnt2 influences the intestinal microbial ecology, we profiled the microbiota of wild-type and B4galnt2-deficient siblings throughout the GI tract using 16S rRNA gene pyrosequencing. This revealed both distinct communities at different anatomic sites and significant changes in composition with respect to genotype, indicating a previously unappreciated role of B4galnt2 in host–microbial homeostasis. Among the numerous B4galnt2-dependent differences identified in the abundance of specific bacterial taxa, we unexpectedly detected a difference in the pathogenic genus, Helicobacter, suggesting Helicobacter spp. also interact with B4galnt2 glycans. In contrast to other glycosyltransferases, we found that the host intestinal B4galnt2 expression is not dependent on presence of the microbiota. Given the long-term maintenance of alleles influencing B4galnt2 expression by natural selection and the GI phenotypes presented here, we suggest that variation in B4galnt2 GI expression may alter susceptibility to GI diseases such as infectious gastroenteritis

    BAAV Mediated GJB2 Gene Transfer Restores Gap Junction Coupling in Cochlear Organotypic Cultures from Deaf Cx26Sox10Cre Mice

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    The deafness locus DFNB1 contains GJB2, the gene encoding connexin26 and GJB6, encoding connexin30, which appear to be coordinately regulated in the inner ear. In this work, we investigated the expression and function of connexin26 and connexin30 from postnatal day 5 to adult age in double transgenic Cx26Sox10Cre mice, which we obtained by crossing connexin26 floxed mice with a deleter Sox10–Cre line. Cx26Sox10Cre mice presented with complete connexin26 ablation in the epithelial gap junction network of the cochlea, whereas connexin30 expression was developmentally delayed; immunolabeling patterns for both connexins were normal in the cochlear lateral wall. In vivo electrophysiological measurements in Cx26Sox10Cre mice revealed profound hearing loss accompanied by reduction of endocochlear potential, and functional experiments performed in postnatal cochlear organotypic cultures showed impaired gap junction coupling. Transduction of these cultures with a bovine adeno associated virus vector restored connexin26 protein expression and rescued gap junction coupling. These results suggest that restoration of normal connexin levels by gene delivery via recombinant adeno associated virus could be a way to rescue hearing function in DFNB1 mouse models and, in future, lead to the development of therapeutic interventions in humans

    Todas as criaturas do mundo: a arte dos mapas como elemento de orientação geográfica

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    Vague in the outlines and abounding in figures of real or fabulous creatures, the iconography of medieval maps played a significant role in helping users to recognize lands that were virtually unknown to Christendom. In a world with no reliable latitudes and longitudes, the land contours, inhabitants and even certain elements of fauna and flora could become variables of utmost importance for geographic orientation. Notwithstanding the higher levels of precision achieved in their efforts to represent geographic space, the considerable advancements made in latitude determination, and their continuous pursuit of a practical method for the establishment of longitudes, the cartographers of the Age of Discoveries still went to the trouble of depicting notable elements - whether real or imaginary - to help travelers get their bearings around different regions of the globe. As the presence of Europeans continued to expand and an authentic scientific revolution took place in the 17th century, the lengthy notes and eye¿catching representations of nature and local inhabitants soon lost their utility as points of reference on 17th-century maps to become mere accessories of aesthetic and commercial value. The advent of the 18th century consolidated, once and for all, the transformation of such illustrations into essentially decorative elements with no other relevant role to play in mapmaking. In addition to decreasing in number, the figures became more stylized and moved to the borders of the maps as ornamental motifs. Although they often maintained some sort of relation with the geographic space depicted on the map, the motifs chosen could also constitute a rather independent element. In fact, allegories, compositions with a variety of mythological figures, and historical representations were often used to underscore the power of certain political agents
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