The Allen Telescope Array Twenty-centimeter Survey - A 690-Square-Degree, 12-Epoch Radio Dataset - I: Catalog and Long-Duration Transient Statistics

We present the Allen Telescope Array Twenty-centimeter Survey (ATATS), a multi-epoch (12 visits), 690 square degree radio image and catalog at 1.4GHz. The survey is designed to detect rare, very bright transients as well as to verify the capabilities of the ATA to form large mosaics. The combined image using data from all 12 ATATS epochs has RMS noise sigma = 3.94mJy / beam and dynamic range 180, with a circular beam of 150 arcsec FWHM. It contains 4408 sources to a limiting sensitivity of S = 20 mJy / beam. We compare the catalog generated from this 12-epoch combined image to the NRAO VLA Sky Survey (NVSS), a legacy survey at the same frequency, and find that we can measure source positions to better than ~20 arcsec. For sources above the ATATS completeness limit, the median flux density is 97% of the median value for matched NVSS sources, indicative of an accurate overall flux calibration. We examine the effects of source confusion due to the effects of differing resolution between ATATS and NVSS on our ability to compare flux densities. We detect no transients at flux densities greater than 40 mJy in comparison with NVSS, and place a 2-sigma upper limit on the transient rate for such sources of 0.004 per square degree. These results suggest that the > 1 Jy transients reported by Matsumura et al. (2009) may not be true transients, but rather variable sources at their flux density threshold.Comment: 41 pages, 19 figures, ApJ accepted; corrected minor typo in Table

The Grizzly, September 21, 1993

Israel and PLO Reach Peace Agreement • The Quilt: To Remember, To Educate, To Celebrate • Russian TV Crew Filming at Ursinus • New Reimert Policies for \u2793-\u2794 • Jurassic Park: It\u27s Only a Movie • Bernie Bernie Headflap Wins the Battle Again! • The Newly Roomie Game • A Unique Affair Awaits Us: Javapalooza \u2793 to Entertain Ursinus • Ursinus Needs AIDS Policy • More Than a Number • The New Wismer? Or a Police State? • Field Hockey Struggles Early • Men\u27s X-Country Starts off 2-0 • Lady Bears Search for Consistencyhttps://digitalcommons.ursinus.edu/grizzlynews/1318/thumbnail.jp

Phase I Randomised Clinical Trial of an HIV-1CN54, Clade C, Trimeric Envelope Vaccine Candidate Delivered Vaginally

We conducted a phase 1 double-blind randomised controlled trial (RCT) of a HIV-1 envelope protein (CN54 gp140) candidate vaccine delivered vaginally to assess immunogenicity and safety. It was hypothesised that repeated delivery of gp140 may facilitate antigen uptake and presentation at this mucosal surface. Twenty two healthy female volunteers aged 18–45 years were entered into the trial, the first receiving open-label active product. Subsequently, 16 women were randomised to receive 9 doses of 100 µg of gp140 in 3 ml of a Carbopol 974P based gel, 5 were randomised to placebo solution in the same gel, delivered vaginally via an applicator. Participants delivered the vaccine three times a week over three weeks during one menstrual cycle, and were followed up for two further months. There were no serious adverse events, and the vaccine was well tolerated. No sustained systemic or local IgG, IgA, or T cell responses to the gp140 were detected following vaginal immunisations. Repeated vaginal immunisation with a HIV-1 envelope protein alone formulated in Carbopol gel was safe, but did not induce local or systemic immune responses in healthy women

Stability Analysis of a Model for the Defect Structure of YBa2Cu3Ox

Unusual microstructures of YBa2Cu3Ox (123) crystals have been observed. These structures have been shown to pass very high transport currents. A model of the solidification of 123 from a melt with Y2BaCuO5 (211) inclusions indicates that the stability of the 123 interface can depend on the sizes of the 211 inclusions. The observed formations are interpreted in the light of this instability

Stability of Growing Front of YBa(2)Cu(3)O(x) Superconductor in the Presence of Pt and CeO(2) Additions

Distinctive microstructures of textured YBa2Cu3Ox (123) superconductors were examined by scanning electron microscopy and metallurgical microscopy. The samples were synthesized under a residual thermal gradient by using a modified melt textured growth on a Y2BaCuO5 (211) substrate. Also, the unidirectional solidification by a zone‐melting method was performed to fabricate 123 superconducting bars up to 12 cm long placed on the 211 substrate in the horizontal arrangement, with a growth rate R=0.5 mm/h and a temperature gradient of G=20 °C/cm (G/R=400 °C h/cm2). A ramping temperature of 1 °C/h (GR) was applied in both syntheses. Typical defects running parallel to (001) planes associated with 211 trapped particles were observed (so‐called platelet structure). Besides these, unusual defects were observed running parallel to (100) and (010) planes in textured 123+Pt superconductors, and interpreted as the result of an instability of the planar front in the presence of fine 211 particles. A theoretical model of planar interface stability confirms a strong dependence of stability region on the size of 211 particles in the melt

Stability of Growing Front of YBa(2)Cu(3)O(x) Superconductor in the Presence of Pt and CeO(2) Additions

Distinctive microstructures of textured YBa2Cu3Ox (123) superconductors were examined by scanning electron microscopy and metallurgical microscopy. The samples were synthesized under a residual thermal gradient by using a modified melt textured growth on a Y2BaCuO5 (211) substrate. Also, the unidirectional solidification by a zone‐melting method was performed to fabricate 123 superconducting bars up to 12 cm long placed on the 211 substrate in the horizontal arrangement, with a growth rate R=0.5 mm/h and a temperature gradient of G=20 °C/cm (G/R=400 °C h/cm2). A ramping temperature of 1 °C/h (GR) was applied in both syntheses. Typical defects running parallel to (001) planes associated with 211 trapped particles were observed (so‐called platelet structure). Besides these, unusual defects were observed running parallel to (100) and (010) planes in textured 123+Pt superconductors, and interpreted as the result of an instability of the planar front in the presence of fine 211 particles. A theoretical model of planar interface stability confirms a strong dependence of stability region on the size of 211 particles in the melt

Stability Analysis of a Model for the Defect Structure of YBa2Cu3Ox

Unusual microstructures of YBa2Cu3Ox (123) crystals have been observed. These structures have been shown to pass very high transport currents. A model of the solidification of 123 from a melt with Y2BaCuO5 (211) inclusions indicates that the stability of the 123 interface can depend on the sizes of the 211 inclusions. The observed formations are interpreted in the light of this instability

Evaluation of cardiac +31P magnetic resonance spectroscopy : Reviewing NMR principles

NRC publication: Ye