11 research outputs found

    Avarietyofalu-mediated copy number variations can underlie il-12rβ1 deficiency

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    Purpose Inborn errors of IFN-γ immunity underlie Mendelian susceptibility to mycobacterial disease (MSMD). Autosomal recessive complete IL-12Rβ1 deficiency is the most frequent genetic etiology of MSMD. Only two of the 84 known mutations are copy number variations (CNVs), identified in two of the 213 IL-12Rβ1-deficient patients and two of the 164 kindreds reported. These two CNVs are large deletions found in the heterozygous or homozygous state. We searched for novel families with IL-12Rβ1 deficiency due to CNVs. Methods We studied six MSMD patients from five unrelated kindreds displaying adverse reactions to BCG vaccination. Three of the patients also presented systemic salmonellosis, two had mucocutaneous candidiasis, and one had disseminated histoplasmosis. We searched for CNVs and other variations by IL12RB1-targeted next-generation sequencing (NGS). Results We identified six new IL-12Rβ1-deficient patients with a complete loss of IL-12Rβ1 expression on phytohemagglutinin-activated T cells and/or EBV-transformed B cells. The cells of these patients did not respond to IL-12 and IL-23. Five different CNVs encompassing IL12RB1 (four deletions and one duplication) were identified in these patients by NGS coverage analysis, either in the homozygous state (n =1)orintrans (n = 4) with a single-nucleotide variation (n = 3) or a small indel (n = 1). Seven of the nine mutations are novel. Interestingly, four of the five CNVs were predicted to be driven by nearby Alu elements, as well as the two previously reported large deletions. The IL12RB1 locus is actually enriched in Alu elements (44.7%), when compared with the rest of the genome (10.5%). Conclusion The IL12RB1 locus is Alu-enriched and therefore prone to rearrangements at various positions. CNVs should be considered in the genetic diagnosis of IL-12Rβ1 deficiency. © �Springer Science+Business Media, LLC, part of Springer Nature 2018

    Improving sightings-derived residency estimation for whale shark aggregations: A novel metric applied to a global data set

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    The world’s largest extant fish, the whale shark Rhincodon typus, is one of the most-studied species of sharks globally. The discovery of predictable aggregation sites where these animals gather seasonally or are sighted year-round – most of which are coastal and juvenile-dominated – has allowed for a rapid expansion of research on this species. The most common method for studying whale sharks at these sites is photographic identification (photo-ID). This technique allows for long-term individual-based data to be collected which can, in turn, be used to evaluate population structure, build population models, identify long-distance movements, and assess philopatry and other population dynamics. Lagged identification rate (LIR) models have fewer underlying assumptions than more traditional capture mark recapture approaches, making them more broadly applicable to marine taxa, especially far-ranging megafauna species like whale sharks. However, the increased flexibility comes at a cost. Parameter estimations based on LIR can be difficult to interpret and may not be comparable between areas with different sampling regimes. Using a unique data-set from the Philippines with ~8 years of nearly continuous survey effort, we were able to derive a metric for converting LIR residency estimates into more intuitive days-per-year units. We applied this metric to 25 different sites allowing for the first quantitatively-meaningful comparison of sightings-derived residence among the world’s whale shark aggregations. We validated these results against the only three published acoustic residence metrics (falling within the ranges established by these earlier works in all cases). The results were then used to understand residency behaviours exhibited by the sharks at each site. The adjusted residency metric is an improvement to LIR-based population modelling, already one of the most widely used tools for describing whale shark aggregations. The standardised methods presented here can serve as a valuable tool for assessing residency patterns of whale sharks, which is crucial for tailored conservation action, and can cautiously be tested in other taxa

    Atomic force microscopy for surface imaging and characterization of supported nanostructures

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    This chapter presents an overview of Atomic Force Microscopy (AFM) principles followed by details on AFM instrumentation. In particular, the frequency modulation method of the non-contact AFM (NC-AFM) used in ultra-high vacuum conditions is explained in detail. Then, applications of NC-AFM for an atomic-scale range characterization of semiconductor and isolator surfaces as well as supported nanostructures are introduced
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