1,456 research outputs found
The QUEST large area CCD camera
We have designed, constructed, and put into operation a very large area CCD camera that covers the field of view of the 1.2 m Samuel Oschin Schmidt Telescope at the Palomar Observatory. The camera consists of 112 CCDs arranged in a mosaic of four rows with 28 CCDs each. The CCDs are 600 x 2400 pixel Sarnoff thinned, back-illuminated devices with 13 ”m x 13 ”m pixels. The camera covers an area of 4.6° x 3.6° on the sky with an active area of 9.6 deg_2. This camera has been installed at the prime focus of the telescope and commissioned, and scientific-quality observations on the Palomar-QUEST Variability Sky Survey were started in 2003 September. The design considerations, construction features, and performance parameters of this camera are described in this paper
Time Domain Explorations With Digital Sky Surveys
One of the new frontiers of astronomical research is the exploration of time
variability on the sky at different wavelengths and flux levels. We have
carried out a pilot project using DPOSS data to study strong variables and
transients, and are now extending it to the new Palomar-QUEST synoptic sky
survey. We report on our early findings and outline the methodology to be
implemented in preparation for a real-time transient detection pipeline. In
addition to large numbers of known types of highly variable sources (e.g., SNe,
CVs, OVV QSOs, etc.), we expect to find numerous transients whose nature may be
established by a rapid follow-up. Whereas we will make all detected variables
publicly available through the web, we anticipate that email alerts would be
issued in the real time for a subset of events deemed to be the most
interesting. This real-time process entails many challenges, in an effort to
maintain a high completeness while keeping the contamination low. We will
utilize distributed Grid services developed by the GRIST project, and implement
a variety of advanced statistical and machine learning techniques.Comment: 5 pages, 2 postscript figures, uses adassconf.sty. To be published
in: "ADASS XIV (2004)", Eds. Patrick Shopbell, Matthew Britton and Rick
Ebert, ASP Conference Serie
An evaluation of several diet acidifiers commonly utilized in pig starter diets to improve growth performance
Early-weaned pigs (weaned at 14 d of age) that are managed in a conventional one-site production system and fed a complex segregated early-weaning diet will benefit from the inclusion of a diet acidifier during the first week. However, the data indicate no benefit from including a diet acidifier in semicomplex diets fed during subsequent growth phases.; Swine Day, Manhattan, KS, November 21, 199
The effects of increasing dietary energy density on growing-finishing pig growth performance and carcass characteristics
Eighty crossbred gilts were used in a growth trial to evaluate the effects of increasing dietary energy density on growing-finishing pig growth performance and carcass characteristics. In this trial, adding fat to corn-soybean meal diets with a constant calorie: lysine ratio to increase the energy density during the growing phase (98 to 160 lb) improved feed efficiency with no influence on growth rate. However, increasing the energy content of the diet by adding fat had no benefit during the finishing phase (160 to 233 lb).; Swine Day, Manhattan, KS, November 16, 199
The effects of increasing dietary energy density on growing-finishing pig growth performance and carcass characteristics
Eighty crossbred gilts were used in a growth trial to evaluate the effects of increasing dietary energy density on growing-finishing pig growth performance and carcass characteristics. In this trial, adding fat to corn-soybean meal diets with a constant calorie: lysine ratio to increase the energy density during the growing phase (98 to 160 lb) improved feed efficiency with no influence on growth rate. However, increasing the energy content of the diet by adding fat had no benefit during the finishing phase (160 to 233 lb).; Swine Day, Manhattan, KS, November 16, 199
Determining the optimal threonine:lysine ratio for the 25 to 50 lb pig
A 21-day growth trial was conducted to determine the threonine: lysine ratio necessary to optimize growth performance of the 25 to 50 Ib pig reared in a high-health, segregated early-weaning (SEW) system. Ten experimental diets, including two levels of lysine (.75% and 1.10% apparent digestible lysine) and five apparent digestible threonine:lysine ratios (40, 47.5, 55, 62.5, and 70%), were used in a 2 x 5 factorial arrangement. Growth performance was improved by feeding 1.10% rather than.75% digestible lysine. Also, results indicated that the apparent digestible threonine requirement for the SEW:-reared, 25 to 50 lb pig is approximately 55% of digestible lysine.; Swine Day, Manhattan, KS, November 21, 199
Commensal Rats and Humans: : Integrating Rodent Phylogeography and Zooarchaeology to Highlight Connections between Human Societies
Phylogeography and zooarchaeology are largely separate disciplines, yet each interrogates relationships between humans and commensal species. Knowledge gained about human history from studies of four commensal rats (Rattus rattus, R. tanezumi, R. exulans, and R. norvegicus) is outlined, and open questions about their spread alongside humans are identified. Limitations of phylogeographic and zooarchaeological studies are highlighted, then how integration would increase understanding of speciesâ demographic histories and resultant inferences about human societies is discussed. How rat expansions have informed the understanding of human migration, urban settlements, trade networks, and intra- and interspecific competition is reviewed. Since each rat species is associated with different human societies, they identify unique ecological and historical/cultural conditions that influenced their expansion. Finally, priority research areas including nuclear genome based phylogeographies are identified using archaeological evidence to understand R. norvegicus expansion across China, multi-wave colonization of R. rattus across Europe, and competition between R. rattus and R. norvegicus
The QUEST RR Lyrae Survey: Confirmation of the Clump at 50 kpc and Other Over-Densities in the Outer Halo
We have measured the periods and light curves of 148 RR Lyrae variables from
V=13.5 to 19.7 from the first 100 sq. degrees of the QUEST RR Lyrae survey.
Approximately 55% of these stars belong to the clump of stars detected earlier
by the Sloan Digital Sky Survey. According to our measurements, this feature
has ~10 times the background density of halo stars, spans at least 37.5 deg by
3.5 deg in right ascension and declination (>=30 by >=3 kpc), lies ~50 kpc from
the Sun, and has a depth along the line of sight of ~5 kpc (1 sigma). These
properties are consistent with the recent models that suggest it is a tidal
stream from the Sgr dSph galaxy. The mean period of the type ab variables, 0.58
d, is also consistent. In addition, we have found two smaller over-densities in
the halo, one of which may be related to the globular cluster Pal 5.Comment: 12 pages (including 4 figures). Accepted for publication in the ApJ
Letter
The effects of experimental potato protein on starter pig growth performance
This study suggested that experimental potato protein can be an effective replacement for a portion of spray-dried animal plasma in starter diets. Pigs fed combinations of experimental potato protein and spray-dried plasma had greater ADG than those fed either protein source alone. In phase II diets, pigs fed experimental potato protein had similar ADG and FIG compared with those fed spray-dried blood meal and select menhaden fish meal.; Swine Day, Manhattan, KS, November 21, 199
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