1,948 research outputs found

    The Tolman Surface Brightness Test for the Reality of the Expansion. III. HST Profile and Surface Brightness Data for Early-Type Galaxies in Three High-Redshift Clusters

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    Photometric data for 34 early-type galaxies in the three high-redshift clusters Cl 1324+3011 (z = 0.76), Cl 1604+4304 (z = 0.90), and Cl 1604+4321 (z = 0.92), observed with the Hubble Space Telescope (HST) and with the Keck 10-meter telescopes by Oke, Postman & Lubin, are analyzed to obtain the photometric parameters of mean surface brightness, magnitudes for the growth curves, and angular radii at various Petrosian eta radii. The angular radii at eta = 1.3 mag for the program galaxies are all larger than 0.24". All of the galaxies are well resolved at this angular size using HST whose point-spread function is 0.05", half width at half maximum. The data for each of the program galaxies are listed at eta = 1.0, 1.3, 1.5, 1.7, and 2.0 mag. They are corrected by color equations and K terms for the effects of redshift to the rest-frame Cape/Cousins I for Cl 1324+3011 and Cl 1604+4304 and R for Cl 1604+4321. The K corrections are calculated from synthetic spectral energy distributions derived from evolving stellar population models of Bruzual & Charlot which have been fitted to the observed broad-band (BVRI) AB magnitudes of each program galaxy. The listed photometric data are independent of all cosmological parameters. They are the source data for the Tolman surface brightness test made in Paper IV.Comment: 17 pages, 7 figures; accepted for publication in the Astronomical Journa

    Response to Intervention in Middle School: A Case Story

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    Response to Intervention (RTI) is a framework that may lead to better teaching and learning through its integration of instruction, intervention, and assessment. An increasing number of states are moving forward with RTI initiatives across grades K-12. The research base for RTI, however, is currently limited to elementary settings. Although this research can inform implementation in the middle grades, the differences in school structure and operations at these levels mean RTI at the middle level will probably look different than it does at the elementary level. This article provides an overview of RTI, focusing, particularly, on how RTI is consistent with many of the characteristics of successful middle schools (National Middle School Association, 2010), and describes in detail the experience and outcomes of RTI implementation in one middle school where the second author serves as principal. The article concludes with a discussion of lessons learned and implications for other middle schools considering RTI implementation

    Expression of neurogenin3 reveals an islet cell precursor population in the pancreas

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    Differentiation of early gut endoderm cells into the endocrine cells forming the pancreatic islets of Langerhans depends on a cascade of gene activation events controlled by transcription factors including the basic helix-loop-helix (bHLH) proteins. To delineate this cascade, we began by establishing the position of neurogenin3, a bHLH factor found in the pancreas during fetal development. We detect neurogenin3 immunoreactivity transiently in scattered ductal cells in the fetal mouse pancreas, peaking at embryonic day 15.5. Although not detected in cells expressing islet hormones or the islet transcription factors Isl1, Brn4, Pax6 or PDX1, neurogenin3 is detected along with early islet differentiation factors Nkx6.1 and Nkx2.2, establishing that it is expressed in immature cells in the islet lineage. Analysis of transcription factor-deficient mice demonstrates that neurogenin3 expression is not dependent on neuroD1/BETA2, Mash1, Nkx2.2, Nkx6.1, or Pax6. Furthermore, early expression of neurogenin3 under control of the Pdx1 promoter is alone sufficient to drive early and ectopic differentiation of islet cells, a capability shared by the pancreatic bHLH factor, neuroD1/BETA2, but not by the muscle bHLH factor, MyoD. However, the islet cells produced in these transgenic experiments are overwhelmingly α cells, suggesting that factors other than the bHLH factors are required to deviate from a default α cell fate. These data support a model in which neurogenin3 acts upstream of other islet differentiation factors, initiating the differentiation of endocrine cells, but switching off prior to final differentiation. The ability to uniquely identify islet cell precursors by neurogenin3 expression allows us to determine the position of other islet transcription factors in the differentiation cascade and to propose a map for the islet cell differentiation pathway

    Mind Your Meds: Safe Opioid Disposal Awareness

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    Driven by the effects of the opioid epidemic on friends, family members, students, and patients, members of the 2019 GEHLI Team “Mission Possible” are dedicated to bolstering educational awareness of safe leftover opioid disposal methods to decrease the supply of opioids in our community. On average, over 2/3 of opioid prescription medications are leftover and lead to later misuse or abuse (JAMA Survey). Despite a decrease in prescription writing for pain medication over the years, the mortality rate from overdose, and the rate of infants born to mothers with opioid abuse continues to steadily increase in Virginia (VDH). Team Mission Possible seeks to promote awareness of both the need and resources available for safe opioid disposal by educating prescribers in the VCU Health system and spreading knowledge to VCU patients, students, faculty, staff, and members of the surrounding community through: educational events on the Monroe Park and Medical campuses; teaming up with Miss Virginia’s “Mind your Meds campaign”; live Facebook interviews; and educational flyers

    Functional plasticity in the type IV secretion system of Helicobacter pylori.

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    Helicobacter pylori causes clinical disease primarily in those individuals infected with a strain that carries the cytotoxin associated gene pathogenicity island (cagPAI). The cagPAI encodes a type IV secretion system (T4SS) that injects the CagA oncoprotein into epithelial cells and is required for induction of the pro-inflammatory cytokine, interleukin-8 (IL-8). CagY is an essential component of the H. pylori T4SS that has an unusual sequence structure, in which an extraordinary number of direct DNA repeats is predicted to cause rearrangements that invariably yield in-frame insertions or deletions. Here we demonstrate in murine and non-human primate models that immune-driven host selection of rearrangements in CagY is sufficient to cause gain or loss of function in the H. pylori T4SS. We propose that CagY functions as a sort of molecular switch or perhaps a rheostat that alters the function of the T4SS and "tunes" the host inflammatory response so as to maximize persistent infection
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