29 research outputs found
UBVRI Light Curves of 44 Type Ia Supernovae
We present UBVRI photometry of 44 type-Ia supernovae (SN Ia) observed from
1997 to 2001 as part of a continuing monitoring campaign at the Fred Lawrence
Whipple Observatory of the Harvard-Smithsonian Center for Astrophysics. The
data set comprises 2190 observations and is the largest homogeneously observed
and reduced sample of SN Ia to date, nearly doubling the number of
well-observed, nearby SN Ia with published multicolor CCD light curves. The
large sample of U-band photometry is a unique addition, with important
connections to SN Ia observed at high redshift. The decline rate of SN Ia
U-band light curves correlates well with the decline rate in other bands, as
does the U-B color at maximum light. However, the U-band peak magnitudes show
an increased dispersion relative to other bands even after accounting for
extinction and decline rate, amounting to an additional ~40% intrinsic scatter
compared to B-band.Comment: 84 authors, 71 pages, 51 tables, 10 figures. Accepted for publication
in the Astronomical Journal. Version with high-res figures and electronic
data at http://astron.berkeley.edu/~saurabh/cfa2snIa
C. L. Downing, Salvation from Cinema: The Medium is the Message. New York and Abingdon: Routledge, 2016. Pp. viii, 196. Pb. ÂŁ33.99. ISBN 978-1-138-91394-3
Review of this book on theology and film for Modern Believing
Evolution of a Human Immunodeficiency Virus Type 1 Variant with Enhanced Replication in Pig-Tailed Macaque Cells by DNA Shuffling
DNA shuffling facilitated the evolution of a human immunodeficiency virus type 1 (HIV-1) variant with enhanced replication in pig-tailed macaque peripheral blood mononuclear cells (pt mPBMC). This variant consists exclusively of HIV-1-derived sequences with the exception of simian immunodeficiency virus (SIV) nef. Sequences spanning the gag-protease-reverse transcriptase (gag-pro-RT) region from several HIV-1 isolates were shuffled and cloned into a parental HIV-1 backbone containing SIV nef. Neither this full-length parent nor any of the unshuffled HIV-1 isolates replicated appreciably or sustainably in pt mPBMC. Upon selection of the shuffled viral libraries by serial passaging in pt mPBMC, a species emerged which replicated at substantially higher levels (50 to 100 ng/ml p24) than any of the HIV-1 parents and most importantly, could be continuously passaged in pt mPBMC. The parental HIV-1 isolates, when selected similarly, became extinct. Analyses of full-length improved proviral clones indicate that multiple recombination events in the shuffled region and adaptive changes in the rest of the genome contributed synergistically to the improved phenotype. This improved variant may prove useful in establishing a pig-tailed macaque model of HIV-1 infection
A glycosidase antibody elicited against a chair-like transition state analog by in vitro immunization
A limit on the number density of bright zâ 7 galaxies
We present a survey of bright optical dropout sources in two deep, multiwavelength surveys comprising 11 widely separated fields, aimed at constraining the galaxy luminosity function at zâ 7 for sources at 5â10 L* (z= 6). Our combined survey area is 225 arcmin2 to a depth of JAB= 24.2 (3Ï) and 135 arcmin2 to J= 25.3 (4Ï). We find that infrared data longwards of 2 ÎŒm are essential for classifying optical dropout sources, and in particular for identifying cool Galactic star contaminants. Our limits on the number density of high-redshift sources are consistent with current estimates of the Lyman break galaxy luminosity function at z= 6