Recent H-alpha results on pulsar B2224+65's bow-shock nebula, the "Guitar"

We used the 4 m Discovery Channel Telescope (DCT) at Lowell observatory in 2014 to observe the Guitar Nebula, an Hα bow-shock nebula around the high-velocity radio pulsar B2224+65. Since the nebula`s discovery in 1992, the structure of the bow-shock has undergone significant dynamical changes. We have observed the limb structure, targeting the "body" and "neck" of the guitar. Comparing the DCT observations to 1995 observations with the Palomar 200-inch Hale telescope, we found changes in both spatial structure and surface brightness in the tip, head, and body of the nebula

Synthesis and structure of sterically overloaded tetra-coordinated yttrium and lanthanum disiloxides

The NSF is thanked for purchase of a JEOL ECS-400 NMR Spectrometer (CRIF-MU CHE-1048553).The synthesis, structures and reactivity of the spirocyclic yttrium and lanthanum disiloxides {[(CH2R2SiO)2]2M}H [M = Ln, Y; R = SiMe(SiMe3)2] 3 and 4 are reported. Compounds 3 and 4 were prepared from reactions of two equivalents of [CH2(R)2SiOH]2 [R = Si(SiMe3)2Me] ( 1 ) with one equivalent of M[N(SiMe3)2]2 (M = Y, La), respectively.PostprintPeer reviewe

Black Hole Condensation and the Unification of String Vacua

It is argued that black hole condensation can occur at conifold singularities in the moduli space of type II Calabi--Yau string vacua. The condensate signals a smooth transition to a new Calabi--Yau space with different Euler characteristic and Hodge numbers. In this manner string theory unifies the moduli spaces of many or possibly all Calabi--Yau vacua. Elementary string states and black holes are smoothly interchanged under the transitions, and therefore cannot be invariantly distinguished. Furthermore, the transitions establish the existence of mirror symmetry for many or possibly all Calabi--Yau manifolds.Comment: 15 pages, harvma

MBX-102/JNJ39659100, a Novel Non-TZD Selective Partial PPAR-γ Agonist Lowers Triglyceride Independently of PPAR-α Activation

MBX-102/JNJ-39659100 (MBX-102) is a selective, partial PPAR-γ agonist that lowers glucose in the absence of some of the side effects, such as weight gain and edema, that are observed with the TZDs. Interestingly MBX-102 also displays pronounced triglyceride lowering in preclinical rodent models and in humans. Although in vitro reporter gene studies indicated that MBX-102 acid is a highly selective PPAR-γ agonist that lacks PPAR-α activity, we sought to determine if PPAR-α activation in vivo could possibly contribute to the triglyceride lowering abilities of MBX-102. In vivo studies using ZDF and ZF rats demonstrated that MBX-102 lowered plasma triglycerides. However in ZF rats, MBX-102 had no effect on liver weight or on hepatic expression levels of PPAR-α target genes. Further in vitro studies in primary human hepatocytes supported these findings. Finally, the ability of MBX-102 to lower triglycerides was maintained in PPAR-α knockout mice, unambiguously establishing that the triglyceride lowering effect of MBX-102 is PPAR-α independent. The in vivo lipid lowering abilities of MBX-102 are therefore mediated by an alternate mechanism which is yet to be determined

The Grizzly, October 19, 1979

Ursinus - Tohoku Make Exchange • Campus Life Committee • Faculty Makes Recommendations About College Curriculum • Women\u27s Financial Workshop Offered • Letters to the Editor • Ursinus News In Brief: Student teachers assigned; Generous alumni gifts; Alternate weekend • 1979 Homecoming Candidates • The Who - An Interesting Saga • The Long Run - Always Sincere • ProTheatre To Open • Knack Review • Music News: Disco, Tom Petty • C.S. Lewis Forum • Super Sundae • USGA Notes • Fearless Friday Forecast • Young Artists Series Resume • Life In Your Nasal Passage: Frat War Is Hell!!! • Sports Profile: Jim Birchmeier • Harriers Undefeated • Danworth Graduate Fellowships Open • Booters Lose In O.T. • Volleyball Team Aims For .500 Season Record • Gridders Downed In Closing Seconds • Hockey\u27s 3 & 4 Win In Squeakerhttps://digitalcommons.ursinus.edu/grizzlynews/1024/thumbnail.jp

Fluorine substitutions in an antigenic peptide selectively modulate T cell receptor binding in a minimally perturbing manner

T cell receptor (TCR) recognition of antigenic peptides bound and presented by major histocompatibility complex (MHC) molecules forms the basis of the cellular immune response to pathogens and cancer. TCRs bind peptide/MHC molecules weakly and with fast kinetics, features which have hindered detailed biophysical studies of these interactions. Modified peptides resulting in enhanced TCR binding could help overcome these challenges. Further, there is considerable interest in using modified peptides with enhanced TCR binding as the basis for clinical vaccines. Here, we studied how fluorine substitutions in an antigenic peptide can selectively impact TCR recognition. Using a structure-guided design approach, we found that fluorination of the HTLV-1 Tax11-19 peptide (Tax) enhanced binding by the Tax-specific TCR A6, yet weakened binding by the Tax-specific TCR B7. The changes in affinity were consistent with crystallographic structures and fluorine chemistry, and with A6, independent of other substitutions in the interface. Peptide fluorination thus provides a means to selectively modulate TCR binding affinity without significantly perturbing peptide composition or structure. Lastly, in probing the mechanism of fluorine’s effect on TCR binding, our data were most consistent with fluorine’s unique “polar hydrophobicity,” a finding which should impact other attempts to alter molecular recognition with fluorine

SDSS J161033.64-010223.3: A second Cataclysmic Variable with a Non-radially Pulsating Primary

We find from high speed photometry of the Sloan Digital Survey cataclysmic variable candidate SDSS J161033.64-010223.3 that it has a double humped modulation, which is probably orbital, with a period of 80.52 minutes, and shows strong ZZ Cet type pulsations. The largest amplitude oscillations have periods near 607, 345, 304 and 221 s. The amplitudes of some of the oscillations are seen to vary on time scales of hours, indicating modes with unresolved multiplets in which the splittings are ~1 d^-1. This is only the second dwarf nova found to have non-radial pulsations of its white dwarf primary.Comment: 4 pages, 5 figures; Accepted for publication in MNRA

GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy

GLIMPSE (Galactic Legacy Infrared Mid-Plane Survey Extraordinaire), a SIRTF Legacy Science Program, will be a fully sampled, confusion-limited infrared survey of the inner two-thirds of the Galactic disk with a pixel resolution of \~1.2" using the Infrared Array Camera (IRAC) at 3.6, 4.5, 5.8, and 8.0 microns. The survey will cover Galactic latitudes |b| <1 degree and longitudes |l|=10 to 65 degrees (both sides of the Galactic center). The survey area contains the outer ends of the Galactic bar, the Galactic molecular ring, and the inner spiral arms. The GLIMPSE team will process these data to produce a point source catalog, a point source data archive, and a set of mosaicked images. We summarize our observing strategy, give details of our data products, and summarize some of the principal science questions that will be addressed using GLIMPSE data. Up-to-date documentation, survey progress, and information on complementary datasets are available on the GLIMPSE web site: www.astro.wisc.edu/glimpse.Comment: Description of GLIMPSE, a SIRTF Legacy project (Aug 2003 PASP, in press). Paper with full res.color figures at http://www.astro.wisc.edu/glimpse/glimpsepubs.htm

Activin Receptor Type 2A (ACVR2A) Functions Directly in Osteoblasts as a Negative Regulator of Bone Mass

Bone and skeletal muscle mass are highly correlated in mammals, suggesting the existence of common anabolic signaling networks that coordinate the development of these two anatomically adjacent tissues. The activin signaling pathway is an attractive candidate to fulfill such a role. Here, we generated mice with conditional deletion of activin receptor (ACVR) type 2A, ACVR2B, or both, in osteoblasts, to determine the contribution of activin receptor signaling in regulating bone mass. Immunohistochemistry localized ACVR2A and ACVR2B to osteoblasts and osteocytes. Primary osteoblasts expressed activin signaling components, including ACVR2A, ACVR2B, and ACVR1B (ALK4) and demonstrated increased levels of phosphorylated Smad2/3 upon exposure to activin ligands. Osteoblasts lacking ACVR2B did not show significant changes in vitro. However, osteoblasts deficient in ACVR2A exhibited enhanced differentiation indicated by alkaline phosphatase activity, mineral deposition, and transcriptional expression of osterix, osteocalcin, and dentin matrix acidic phosphoprotein 1. To investigate activin signaling in osteoblasts in vivo, we analyzed the skeletal phenotypes of mice lacking these receptors in osteoblasts and osteocytes (osteocalcin-Cre). Similar to the lack of effect in vitro, ACVR2B-deficient mice demonstrated no significant change in any bone parameter. By contrast, mice lacking ACVR2A had significantly increased femoral trabecular bone volume at 6 weeks of age. Moreover, mutant mice lacking both ACVR2A and ACVR2B demonstrated sustained increases in trabecular bone volume, similar to those in ACVR2A single mutants, at 6 and 12 weeks of age. Taken together, these results indicate that activin receptor signaling, predominantly through ACVR2A, directly and negatively regulates bone mass in osteoblasts