1,091 research outputs found

    Immunoproteasome Overexpression Underlies the Pathogenesis of Thyroid Oncocytes and Primary Hypothyroidism: Studies in Humans and Mice

    Get PDF
    BACKGROUND:Oncocytes of the thyroid gland (Hürthle cells) are found in tumors and autoimmune diseases. They have a unique appearance characterized by abundant granular eosinophilic cytoplasm and hyperchromatic nucleus. Their pathogenesis has remained, thus far, unknown. METHODOLOGY/PRINCIPAL FINDINGS:Using transgenic mice chronically expressing IFNgamma in thyroid gland, we showed changes in the thyroid follicular epithelium reminiscent of the human oncocyte. Transcriptome analysis comparing transgenic to wild type thyrocytes revealed increased levels of immunoproteasome subunits like LMP2 in transgenics, suggesting an important role of the immunoproteasome in oncocyte pathogenesis. Pharmacologic blockade of the proteasome, in fact, ameliorated the oncocytic phenotype. Genetic deletion of LMP2 subunit prevented the development of the oncocytic phenotype and primary hypothyroidism. LMP2 was also found expressed in oncocytes from patients with Hashimoto thyroiditis and Hürthle cell tumors. CONCLUSIONS/SIGNIFICANCE:In summary, we report that oncocytes are the result of an increased immunoproteasome expression secondary to a chronic inflammatory milieu, and suggest LMP2 as a novel therapeutic target for the treatment of oncocytic lesions and autoimmune hypothyroidism

    In everlasting fight against academic procrastination: The roles of classroom engagement and internal locus of control

    Get PDF
    This study aims to test the hypothesis that classroom engagement mediates the relationship between students’ internal locus of control and academic procrastination. As many as 302 students from a private university between 18 to 26 years of age were recruited to respond to Internal-External Locus of control Scale, Classroom Engagement Inventory, and Academic Procrastination scale. Bootstrapping analyses were conducted by utilizing PROCESS Macro model 4 in SPSS software, and the results showed that the mediator variable fully mediates the link between the predictor and outcome variables. In other words, the direct effect of internal locus of control on academic procrastination was no longer significant when controlling for classroom engagement. Further discussion, implications and suggestions were presented at the end of the article

    Standardized Neon Organismal Data for Biodiversity Research

    Get PDF
    Understanding patterns and drivers of species distribution and abundance, and thus biodiversity, is a core goal of ecology. Despite advances in recent decades, research into these patterns and processes is currently limited by a lack of standardized, high-quality, empirical data that span large spatial scales and long time periods. The NEON fills this gap by providing freely available observational data that are generated during robust and consistent organismal sampling of several sentinel taxonomic groups within 81 sites distributed across the United States and will be collected for at least 30 years. The breadth and scope of these data provide a unique resource for advancing biodiversity research. To maximize the potential of this opportunity, however, it is critical that NEON data be maximally accessible and easily integrated into investigators\u27 workflows and analyses. To facilitate its use for biodiversity research and synthesis, we created a workflow to process and format NEON organismal data into the ecocomDP (ecological community data design pattern) format that were available through the ecocomDP R package; we then provided the standardized data as an R data package (neonDivData). We briefly summarize sampling designs and data wrangling decisions for the major taxonomic groups included in this effort. Our workflows are open-source so the biodiversity community may: add additional taxonomic groups; modify the workflow to produce datasets appropriate for their own analytical needs; and regularly update the data packages as more observations become available. Finally, we provide two simple examples of how the standardized data may be used for biodiversity research. By providing a standardized data package, we hope to enhance the utility of NEON organismal data in advancing biodiversity research and encourage the use of the harmonized ecocomDP data design pattern for community ecology data from other ecological observatory networks

    Hubble Space Telescope and Ground-Based Observations of the Type Iax Supernovae SN 2005hk and SN 2008A

    Full text link
    We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [Fe II] and [Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n_e >~ 10^9 cm^-3. Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected "infrared catastrophe," a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a "complete deflagration" that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.Comment: 20 pages, 15 figure

    LSQ13ddu: a rapidly evolving stripped-envelope supernova with early circumstellar interaction signatures

    Get PDF
    This paper describes the rapidly evolving and unusual supernova LSQ13ddu, discovered by the La Silla-QUEST survey. LSQ13ddu displayed a rapid rise of just 4.8 ± 0.9 d to reach a peak brightness of −19.70 ± 0.02 mag in the LSQgr band. Early spectra of LSQ13ddu showed the presence of weak and narrow HeI features arising from interaction with circumstellar material (CSM). These interaction signatures weakened quickly, with broad features consistent with those seen in stripped-envelope SNe becoming dominant around two weeks after maximum. The narrow HeI velocities are consistent with the wind velocities of luminous blue variables but its spectra lack the typically seen hydrogen features. The fast and bright early light curve is inconsistent with radioactive ⁵⁶Ni powering but can be explained through a combination of CSM interaction and an underlying ⁵⁶Ni decay component that dominates the later time behaviour of LSQ13ddu. Based on the strength of the underlying broad features, LSQ13ddu appears deficient in He compared to standard SNe Ib
    corecore