80 research outputs found

    Multilocus Sequence Typing Reveals Extensive Genetic Diversity of the Emerging Fungal Pathogen Scedosporium aurantiacum

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    Scedosporium spp. are the second most prevalent filamentous fungi after Aspergillus spp. recovered from cystic fibrosis (CF) patients in various regions of the world. Although invasive infection is uncommon prior to lung transplantation, fungal colonization may be a risk factor for invasive disease with attendant high mortality post-transplantation. Abundant in the environment, Scedosporium aurantiacum has emerged as an important fungal pathogen in a range of clinical settings. To investigate the population genetic structure of S. aurantiacum, a MultiLocus Sequence Typing (MLST) scheme was developed, screening 24 genetic loci for polymorphisms on a tester strain set. The six most polymorphic loci were selected to form the S. aurantiacum MLST scheme: actin (ACT), calmodulin (CAL), elongation factor-1α (EF1α), RNA polymerase subunit II (RPB2), manganese superoxide dismutase (SOD2), and β-tubulin (TUB). Among 188 global clinical, veterinary, and environmental strains, 5 to 18 variable sites per locus were revealed, resulting in 8 to 23 alleles per locus. MLST analysis observed a markedly high genetic diversity, reflected by 159 unique sequence types. Network analysis revealed a separation between Australian and non-Australian strains. Phylogenetic analysis showed two major clusters, indicating correlation with geographic origin. Linkage disequilibrium analysis revealed evidence of recombination. There was no clustering according to the source of the strains: clinical, veterinary, or environmental. The high diversity, especially amongst the Australian strains, suggests that S. aurantiacum may have originated within the Australian continent and was subsequently dispersed to other regions, as shown by the close phylogenetic relationships between some of the Australian sequence types and those found in other parts of the world. The MLST data are accessible at http://mlst.mycologylab.org. This is a joined publication of the ISHAM/ECMM working groups on “Scedosporium/Pseudallescheria Infections” and “Fungal Respiratory Infections in Cystic Fibrosis”.Peer Reviewe

    Proposed nomenclature for Pseudallescheria, Scedosporium and related genera

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    As a result of fundamental changes in the International Code of Nomenclature on the use of separate names for sexual and asexual stages of fungi, generic names of many groups should be reconsidered. Members of the ECMM/ISHAM working group on Pseudallescheria/Scedosporium infections herein advocate a novel nomenclature for genera and species in Pseudallescheria, Scedosporium and allied taxa. The generic names Parascedosporium, Lomentospora, Petriella, Petriellopsis, and Scedosporium are proposed for a lineage within Microascaceae with mostly Scedosporium anamorphs producing slimy, annellidic conidia. Considering that Scedosporium has priority over Pseudallescheria and that Scedosporium prolificans is phylogenetically distinct from the other Scedosporium species, some name changes are proposed. Pseudallescheria minutispora and Petriellidium desertorum are renamed as Scedosporium minutisporum and S. desertorum, respectively. Scedosporium prolificans is renamed as Lomentospora prolificans

    Cryptococcal meningitis: epidemiology, immunology, diagnosis and therapy.

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    HIV-associated cryptococcal meningitis is by far the most common cause of adult meningitis in many areas of the world that have high HIV seroprevalence. In most areas in Sub-Saharan Africa, the incidence of cryptococcal meningitis is not decreasing despite availability of antiretroviral therapy, because of issues of adherence and retention in HIV care. In addition, cryptococcal meningitis in HIV-seronegative individuals is a substantial problem: the risk of cryptococcal infection is increased in transplant recipients and other individuals with defects in cell-mediated immunity, and cryptococcosis is also reported in the apparently immunocompetent. Despite therapy, mortality rates in these groups are high. Over the past 5 years, advances have been made in rapid point-of-care diagnosis and early detection of cryptococcal antigen in the blood. These advances have enabled development of screening and pre-emptive treatment strategies aimed at preventing the development of clinical infection in patients with late-stage HIV infection. Progress in optimizing antifungal combinations has been aided by evaluation of the clearance rate of infection by using serial quantitative cultures of cerebrospinal fluid (CSF). Measurement and management of raised CSF pressure, a common complication, is a vital component of care. In addition, we now better understand protective immune responses in HIV-associated cases, immunogenetic predisposition to infection, and the role of immune-mediated pathology in patients with non-HIV associated infection and in the context of HIV-associated immune reconstitution reactions

    Replication package for Endogenous Production Networks with Fixed Costs

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    Replication files for "Endogenous Production Networks with Fixed Costs" by Emmanuel Dhyne, Ken Kikkawa, Xianglong Kong, Magne Mogstad, Felix TintelnotTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

    What Drives Home Market Advantage?

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    In the automobile industry, as in many tradable goods markets, firms earn their highest market share within their domestic market. This home market advantage persists despite substantial integration of international markets during the past several decades. The goal of this paper is to quantify the supply- and demand-driven sources of the home market advantage and to understand their implications for international trade and investment. Building on the random coefficients demand model developed by Berry, Levinsohn, and Pakes (1995), we estimate demand and supply in the automobile industry for nine countries across three continents, allowing for unobserved taste and cost variation at the car model and market levels. While trade and foreign production costs as well as taste heterogeneity matter for market outcomes, we find that preference for domestic brands is the single most important driver of home market advantage - even after controlling for brand histories and dealer networks

    What Drives Home Market Advantage?

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    In the automobile industry, as in many tradable goods markets, firms usually earn their highest market share within their domestic market. The goal of this paper is to disentangle the supply- and demand-driven sources of the home market advantage. While trade costs, foreign production costs, and taste heterogeneity all matter for market outcomes, we find that a preference for home brands is the single most important driver of home market advantage—even after controlling for brand histories and dealer networks. Furthermore, we also find that consumers favor domestically producing brands even if these brands originated from a foreign country. Therefore, our results suggest a novel demand effect of FDI: Establishing local production increases demand for the brand even in the absence of any cost savings
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