594 research outputs found

    Analysis of IgE turnover in non-sensitized and sensitized rats.

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    BACKGROUND: Although the levels of immunoglobulin E (IgE) in the circulating blood are often elevated in patients with allergic diseases, such levels cannot always be considered as pathognomonic signs of allergy. The induction of allergic reactions in the tissue was inferred to be related to the amount of IgE passing through the vascular wall. AIMS: We attempted to clarify which compartment, the intravascular or extravascular, plays an important role in the regulation of the turnover of rat IgE. METHODS: The level of DNP-specific rat IgE in the serum was estimated by IgE-capture enzyme-linked immunosorbent assay, and the turnover of IgE was analyzed from its pharmacokinetic parameters. RESULTS: The transfer rate constants from the central to tissue compartment (Kct) were larger than those from the tissue to central compartment (Ktc) irrespective of the sensitized state. The value of the distribution volume of the tissue compartment (Vt) was larger than that of the distribution volume of the central compartment (Vc) irrespective of the sensitized state. CONCLUSIONS: These Findings suggest that the short half-life of rat IgE in the circulation could be attributable to the distribution of IgE from the intravascular to the extravascular compartment

    Proximity to Fermi-surface topological change in superconducting LaO0.54F0.46BiS2

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    The electronic structure of nearly optimally-doped novel superconductor LaO1−x_{1-x}Fx_xBiS2_2 (x{\it x} = 0.46) was investigated using angle-resolved photoemission spectroscopy (ARPES). We clearly observed band dispersions from 2 to 6 eV binding energy and near the Fermi level (EF{\it E}_{\rm F}), which are well reproduced by first principles calculations when the spin-orbit coupling is taken into account. The ARPES intensity map near EF{\it E}_{\rm F} shows a square-like distribution around the Γ\Gamma(Z) point in addition to electronlike Fermi surface (FS) sheets around the X(R) point, indicating that FS of LaO0.54_{0.54}F0.46_{0.46}BiS2_2 is in close proximity to the theoretically-predicted topological change.Comment: 6 pages, 3 figures, + supplemental materia

    Origins of thermal spin depolarization in half-metallic ferromagnet CrO2_2

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    Using high-resolution spin-resolved photoemission spectroscopy, we observed a thermal spin depolarization to which all spin-polarized electrons contribute. Furthermore we observed a distinct minority spin state near the Fermi level and a corresponding depolarization that seldom contributes to demagnetization. The origin of this depolarization has been identified as the many-body effect characteristics of half-metallic ferromagnets. Our investigation opens an experimental field of itinerant ferromagnetic physics focusing on phenomena with sub-meV energy scale.Comment: 19 pages, 10 figure

    Species-level functional profiling of metagenomes and metatranscriptomes.

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    Functional profiles of microbial communities are typically generated using comprehensive metagenomic or metatranscriptomic sequence read searches, which are time-consuming, prone to spurious mapping, and often limited to community-level quantification. We developed HUMAnN2, a tiered search strategy that enables fast, accurate, and species-resolved functional profiling of host-associated and environmental communities. HUMAnN2 identifies a community's known species, aligns reads to their pangenomes, performs translated search on unclassified reads, and finally quantifies gene families and pathways. Relative to pure translated search, HUMAnN2 is faster and produces more accurate gene family profiles. We applied HUMAnN2 to study clinal variation in marine metabolism, ecological contribution patterns among human microbiome pathways, variation in species' genomic versus transcriptional contributions, and strain profiling. Further, we introduce 'contributional diversity' to explain patterns of ecological assembly across different microbial community types

    Rapid Evolution of Coral Proteins Responsible for Interaction with the Environment

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    Christian R. Voolstra is with King Abdullah University of Science and Technology, Shinichi Sunagawa is with the European Molecular Biology Laboratory, Mikhail V. Matz is with UT Austin, Till Bayer is with King Abdullah University of Science and Technology, Manuel Aranda is with King Abdullah University of Science and Technology, Emmanuel Buschiazzo is with University of California Merced, Michael K. DeSalvo is with University of California San Francisco, Erika Lindquist is with the Department of Energy Joint Genome Institute, Alina M. Szmant is with University of North Carolina Wilmington, Mary Alice Coffroth is with State University of New York at Buffalo, Mónica Medina is with University of California Merced.Background -- Corals worldwide are in decline due to climate change effects (e.g., rising seawater temperatures), pollution, and exploitation. The ability of corals to cope with these stressors in the long run depends on the evolvability of the underlying genetic networks and proteins, which remain largely unknown. A genome-wide scan for positively selected genes between related coral species can help to narrow down the search space considerably. Methodology/Principal Findings -- We screened a set of 2,604 putative orthologs from EST-based sequence datasets of the coral species Acropora millepora and Acropora palmata to determine the fraction and identity of proteins that may experience adaptive evolution. 7% of the orthologs show elevated rates of evolution. Taxonomically-restricted (i.e. lineage-specific) genes show a positive selection signature more frequently than genes that are found across many animal phyla. The class of proteins that displayed elevated evolutionary rates was significantly enriched for proteins involved in immunity and defense, reproduction, and sensory perception. We also found elevated rates of evolution in several other functional groups such as management of membrane vesicles, transmembrane transport of ions and organic molecules, cell adhesion, and oxidative stress response. Proteins in these processes might be related to the endosymbiotic relationship corals maintain with dinoflagellates in the genus Symbiodinium. Conclusion/Relevance -- This study provides a birds-eye view of the processes potentially underlying coral adaptation, which will serve as a foundation for future work to elucidate the rates, patterns, and mechanisms of corals' evolutionary response to global climate change.This work was supported by DEB-1054766 to M.V.M. and National Science Foundation grants IOS-0644438 and OCE-0313708 to M.M., and by a Collaborative Travel Fund to C.R.V. made by King Abdullah University of Science and Technology (KAUST). The work conducted by the U.S. Department of Energy Joint Genome Institute is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Biological Sciences, School o

    Surface Modification and Planar Defects of Calcium Carbonates by Magnetic Water Treatment

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    Powdery calcium carbonates, predominantly calcite and aragonite, with planar defects and cation–anion mixed surfaces as deposited on low-carbon steel by magnetic water treatment (MWT) were characterized by X-ray diffraction, electron microscopy, and vibration spectroscopy. Calcite were found to form faceted nanoparticles having 3x () commensurate superstructure and with well-developed {} and {} surfaces to exhibit preferred orientations. Aragonite occurred as laths having 3x () commensurate superstructure and with well-developed () surface extending along [100] direction up to micrometers in length. The (hkil)-specific coalescence of calcite and rapid lath growth of aragonite under the combined effects of Lorentz force and a precondensation event account for a beneficial larger particulate/colony size for the removal of the carbonate scale from the steel substrate. The coexisting magnetite particles have well-developed {011} surfaces regardless of MWT

    Diversity and dynamics of bacterial communities in early life stages of the Caribbean coral Porites astreoides

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    In this study, we examine microbial communities of early developmental stages of the coral Porites astreoides by sequence analysis of cloned 16S rRNA genes, terminal restriction fragment length polymorphism (TRFLP), and fluorescence in situ hybridization (FISH) imaging. Bacteria are associated with the ectoderm layer in newly released planula larvae, in 4-day-old planulae, and on the newly forming mesenteries surrounding developing septa in juvenile polyps after settlement. Roseobacter clade-associated (RCA) bacteria and Marinobacter sp. are consistently detected in specimens of P. astreoides spanning three early developmental stages, two locations in the Caribbean and 3 years of collection. Multi-response permutation procedures analysis on the TRFLP results do not support significant variation in the bacterial communities associated with P. astreoides larvae across collection location, collection year or developmental stage. The results are the first evidence of vertical transmission (from parent to offspring) of bacteria in corals. The results also show that at least two groups of bacterial taxa, the RCA bacteria and Marinobacter, are consistently associated with juvenile P. astreoides against a complex background of microbial associations, indicating that some components of the microbial community are long-term associates of the corals and may impact host health and survival
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