Email from Kyle Bass at Hayman to Michael DuVally Re Fortune Letter

Series of emails from 3/11/2008 to 4/3/2008

Near-Infrared Photometry of the Type IIn SN 2005ip: The Case for Dust Condensation

Near-infrared photometric observations of the Type IIn SN 2005ip in NGC 2906 reveal large fluxes (>1.3 mJy) in the K_s-band over more than 900 days. While warm dust can explain the late-time K_s-band emission of SN 2005ip, the nature of the dust heating source is ambiguous. Shock heating of pre-existing dust by post-shocked gas is unlikely because the forward shock is moving too slowly to have traversed the expected dust-free cavity by the time observations first reveal the K_s emission. While an infrared light echo model correctly predicts a near-infrared luminosity plateau, heating dust to the observed temperatures of ~1400-1600 K at a relatively large distance from the supernova (> 10^{18} cm) requires an extraordinarily high early supernova luminosity (~1 X 10^{11} L_solar). The evidence instead favors condensing dust in the cool, dense shell between the forward and reverse shocks. Both the initial dust temperature and the evolutionary trend towards lower temperatures are consistent with this scenario. We infer that radiation from the circumstellar interaction heats the dust. While this paper includes no spectroscopic confirmation, the photometry is comparable to other SNe that do show spectroscopic evidence for dust formation. Observations of dust formation in SNe are sparse, so these results provide a rare opportunity to consider SNe Type IIn as dust sources.Comment: 11 pages, 6 figures, 3 tables, Accepted for Publication to ApJ: January 20, 200

STRUCTURE OF THE LARGE MOLECULE DISTRIBUTION IN THE TAURUS MOLECULAR CLOUD

Author Institution: National Radio Astronomy Observatory, Green Bank, WV 24915We present observations of the distribution of long carbon chain molecules in TMC-1. The molecular line intensities for three cyanopolyyne molecules $HC_5N$, $HC_7N$ and $HC_9N$\ were observed in a 25' diameter region. The four molecular line transitions were observed towards TMC-1 using the Robert C. Byrd Green Bank Telescope (GBT). These observations were made simultaneously in the frequency range 12780 to 13540 MHz. The images show the emission is primarily in along a narrow ridge. We present images of the molecular line intensity as a function of position, and compare the locations of peak molecular emission. Near the location of peak line intensity, the emission is well fit by a Gaussian profile. We present the ratio of molecular line intensities for the three species. The angular distribution of the molecules is very similar. We interpret the similarity of structure in terms of the chemical age of regions of the cloud. In addition, if all goes well, we will also present first results form the GBT 18 to 26 GHz Focal Plane Array receiver

Diagnosis and Treatment of a Cervical Vertebral Fracture in a Sulcata Tortoise (Centrochelys sulcata)

info:eu-repo/semantics/publishe

VEGFA Family Isoforms Regulate Spermatogonial Stem Cell Homeostasis in Vivo

The objective of the present study was to investigate vascular endothelial growth factor A (VEGFA) isoform regulation of cell fate decisions of spermatogonial stem cells (SSC) in vivo. The expression pattern and cell-specific distribution of VEGF isoforms, receptors, and coreceptors during testis development postnatal d 1–180 suggest a nonvascular function for VEGF regulation of early germ cell homeostasis. Populations of undifferentiated spermatogonia present shortly after birth were positive for VEGF receptor activation as demonstrated by immunohistochemical analysis. Thus, we hypothesized that proangiogenic isoforms of VEGF (VEGFA(164)) stimulate SSC self-renewal, whereas antiangiogenic isoforms of VEGF (VEGFA(165)b) induce differentiation of SSC. To test this hypothesis, we used transplantation to assay the stem cell activity of SSC obtained from neonatal mice treated daily from postnatal d 3–5 with 1) vehicle, 2) VEGFA(164), 3) VEGFA(165)b, 4) IgG control, 5) anti-VEGFA(164), and 6) anti-VEGFA(165)b. SSC transplantation analysis demonstrated that VEGFA(164) supports self-renewal, whereas VEGFA(165)b stimulates differentiation of mouse SSC in vivo. Gene expression analysis of SSC-associated factors and morphometric analysis of germ cell populations confirmed the effects of treatment on modulating the biological activity of SSC. These findings indicate a nonvascular role for VEGF in testis development and suggest that a delicate balance between VEGFA(164) and VEGFA(165)b isoforms orchestrates the cell fate decisions of SSC. Future in vivo and in vitro experimentation will focus on elucidating the mechanisms by which VEGFA isoforms regulate SSC homeostasis