50 research outputs found
Evaluation of a Full-Fat Soybean Ration for Channel Catfish Production in Cages
An experimental ration consisting of 50% full-fat soybeans, heated 170°C, was compared to a commercial trout chow in a 120-day feeding trial using two stocks of channel catfish, Ictalurus punctatus Rafinesque. Catfish were reared in 0.9 m³ floating cages, with 200 fish per cage, anchored in a 1.5 hectare farm pond. A Central Arkansas stock significantly outperformed a Southeast Arkansas stock for comparisons of net production and food conversion efficiency (FCE), with 92% greater production and 41% better FCE, respectively. Survival was 90% or greater for all fish. There was no significant difference in dress-out weight between the stocks. However, the catfish fed the trout ration had significantly lower amounts of body fat. The commercial trout chow overall was significantly better for fish production than the full-fat soybean ration. Production with trout chow was 84% greater than with the full-fat soybean ration. Food conversion efficiency was nearly 41% better with the trout ration, while percent body fat was 11% less. There were no differences in percent survival and percent dress-out weight between the rations. The Central Arkansas stock fed the commercial trout ration had the lowest production cost of 0.47¢ per 0.45 kg live weight, while the Southeastern stock had a higher production cost with either feed
Growth, Mortality, Food Habits, and Fecundity of the Buffalo River Smallmouth Bass
Total length-scale radius, and length-weight relationships were determined for smallmouth bass from the Buffalo River. The back calculated lengths were used in analyzing the age-length data by the Bertalanffy growth formula. Asymptotic length and weight were estimated as 58.3 cm and 4.6 lbs, respectively. Annual mortality of 36 percent was estimated by the catch curve method. Insects (54%), fishes (16%), and crayfish (14%) were the abundant food organisms by frequency of occurrence; while fishes (64%) and crayfish (29%) were the dominant food items by the gravimetric method. Based on the gonosomatic indices and frequency distribution of ovum diameter measurements, smallmouth bass spawn during April-June. All ova greater than or equal to 1.1 mm were considered mature and the relationships between total length, weight, and age to fecundity were estimated as: log F =5.05 logL-8.89301 ;F =18.56 W -1680.4; log F =3.84 log A +1.51560, respectively
Upper limits on the strength of periodic gravitational waves from PSR J1939+2134
The first science run of the LIGO and GEO gravitational wave detectors
presented the opportunity to test methods of searching for gravitational waves
from known pulsars. Here we present new direct upper limits on the strength of
waves from the pulsar PSR J1939+2134 using two independent analysis methods,
one in the frequency domain using frequentist statistics and one in the time
domain using Bayesian inference. Both methods show that the strain amplitude at
Earth from this pulsar is less than a few times .Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo
Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July
200
Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers
We study frequency dependent (FD) input-output schemes for signal-recycling
interferometers, the baseline design of Advanced LIGO and the current
configuration of GEO 600. Complementary to a recent proposal by Harms et al. to
use FD input squeezing and ordinary homodyne detection, we explore a scheme
which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are
sub-optimal among all possible input-output schemes, provide a global noise
suppression by the power squeeze factor, while being realizable by using
detuned Fabry-Perot cavities as input/output filters. At high frequencies, the
two schemes are shown to be equivalent, while at low frequencies our scheme
gives better performance than that of Harms et al., and is nearly fully
optimal. We then study the sensitivity improvement achievable by these schemes
in Advanced LIGO era (with 30-m filter cavities and current estimates of
filter-mirror losses and thermal noise), for neutron star binary inspirals, and
for narrowband GW sources such as low-mass X-ray binaries and known radio
pulsars. Optical losses are shown to be a major obstacle for the actual
implementation of these techniques in Advanced LIGO. On time scales of
third-generation interferometers, like EURO/LIGO-III (~2012), with
kilometer-scale filter cavities, a signal-recycling interferometer with the FD
readout scheme explored in this paper can have performances comparable to
existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi
ASEAN's unchanged melody? The theory and practice of 'non-interference' in Southeast Asia
This is an Author's Accepted Manuscript of an article published as Jones, Lee. (2010). ASEAN's unchanged melody? The theory and practice of 'non-interference' in Southeast Asia. Pacific Review 23:4, 479-502 as published in PACIFIC REVIEW 2010 © Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/09512748.2010.49599