6,369 research outputs found
Effect Of Lighter (273 Kg) and Heavier (356 Kg) Initial Weight on Growth Performance of Single-Source, Pre-Conditioned Beef Steers Fed A Single Growing-Finishing Diet
The objective of the study was to determine the influence that initial BW has on growth performance responses, efficiency of dietary net energy (NE) utilization, and carcass traits in feedlot steers. Light- and heavy-weight Charolais×Red Angus steers (n = 70) selected from a larger single-source group were used in a 209-d growing-finishing feedlot experiment at the Ruminant Nutrition Center, in Brookings, SD. On d-0 and d-1 weight and hip height (HH) measurements were collected for allotment purposes; the initial experimental weight was the average between d 0 and d 1 BW. Steers were assigned to two groups based on initial BW (light initial weight, LIW = 273kg; heavy initial weight, HIW = 356kg) and allotted into 10 pens (n = 7 steers per pen; 5 pens per experimental group). Steers were fed a common diet containing 16% roughage (13.1% CP and 23.4% NDF, DM basis) once daily. Diet included liquid supplement containing vitamins and minerals to meet or exceed 2016 NASEM requirements with monensin included at 30 g/ton. Experimental data were analyzed as a randomized complete block design with pen as the experimental unit. Treatment was included as a fixed effect and block (location) was considered a random effect in the statistical model. Observed NEm (P = 0.17) and NEg (P = 0.17) for LIW and HIW did not differ. LIW steers had a greater cumulative HH change (P = 0.04). A treatment day interaction (P = 0.05) was observed for HH with HIW steers having a greater HH at all time points. Final BW and carcass-adjusted (HCW/0.625) BW were greater for HIW steers by 13.1% and 13.4% respectively (P ≤ 0.01). HIW steers had a greater DMI (P = 0.01) compared to LIW. Cumulative ADG was greater for HIW by 3% (P = 0.04). LIW steers had improved feed conversion (P = 0.01; 5.95 and 6.62, respectively). HIW steers had greater (P 0.05) HCW, marbling scores, and yield grade (YG), with decreased REA/HCW (P = 0.01) compared to LIW. The distribution of USDA Yield Grade was altered by initial BW (P = 0.04). No differences were detected (P 0.22) for the distribution of Quality grade nor liver abscess prevalence and severity. In conclusion, HIW steers had greater growth, but poorer feed efficiency compared to LIW steers. Steers with a HIW produced fatter carcasses with a greater degree of marbling
An 8-DPSK TCM modem for MSAT-X
This paper describes the real-time digital implementation of an 8-differentiated phase-shift keying (DPSK) trellis-coded modulation (TCM) modem for operation on an L-band, 5 kHz wide, land mobile satellite (LMS) channel. The modem architecture as well as some of the signal processing techniques employed in the modem to combat the LMS channel impairments are described, and the modem performance over the fading channel is presented
Impaired osteoblast differentiation in annexin A2- and -A5-deficient cells.
Annexins are a class of calcium-binding proteins with diverse functions in the regulation of lipid rafts, inflammation, fibrinolysis, transcriptional programming and ion transport. Within bone, they are well-characterized as components of mineralizing matrix vesicles, although little else is known as to their function during osteogenesis. We employed shRNA to generate annexin A2 (AnxA2)- or annexin A5 (AnxA5)-knockdown pre-osteoblasts, and determined whether proliferation or osteogenic differentiation was altered in knockdown cells, compared to pSiren (Si) controls. We report that DNA content, a marker of proliferation, was significantly reduced in both AnxA2 and AnxA5 knockdown cells. Alkaline phosphatase expression and activity were also suppressed in AnxA2- or AnxA5-knockdown after 14 days of culture. The pattern of osteogenic gene expression was altered in knockdown cells, with Col1a1 expressed more rapidly in knock-down cells, compared to pSiren. In contrast, Runx2, Ibsp, and Bglap all revealed decreased expression after 14 days of culture. In both AnxA2- and AnxA5-knockdown, interleukin-induced STAT6 signaling was markedly attenuated compared to pSiren controls. These data suggest that AnxA2 and AnxA5 can influence bone formation via regulation of osteoprogenitor proliferation, differentiation, and responsiveness to cytokines in addition to their well-studied function in matrix vesicles
Fundamental Energy Processes of the Human Body
Within the hand that holds this sheet of paper there throb thousands of engines; each with its own fuel requirements; each yielding varying amounts of work, heat, and waste output. Each is a cell in your body.
Of course, these cells are not completely independent. They share in a society, but especially in an economy, of the whole organism. This economy does not trade dollars of differing currencies; rather, its commerce is in energy of differing forms.
A particularly important asset is thermal energy. It is the natural by-product of the various energy conversion processes, the biochemical reactions within the body. But, additionally, its average level of distribution throughout the body (i.e., the body\u27s temperature) is significant in the maintenance of the proper rate of these same biochemical reactions.
The purpose of this module is to characterize and evaluate the energy management of the body, with special emphasis on relating the physical processes of thermal energy transport (i.e., heat flow) to the body·s temperature regulation process
Star formation in galaxy mergers with realistic models of stellar feedback and the interstellar medium
We use hydrodynamic simulations with detailed, explicit models for stellar feedback to study galaxy mergers. These high-resolution (∼1 pc) simulations follow the formation and destruction of individual giant molecular clouds (GMC) and star clusters. We find that the final starburst is dominated by in situ star formation, fuelled by gas which flows inwards due to global torques. The resulting high gas density results in rapid star formation. The gas is self-gravitating, and forms massive (≲10¹⁰ M_⊙) GMC and subsequently super star clusters (with masses up to 10⁸ M_⊙). However, in contrast to some recent simulations, the bulk of new stars which eventually form the central bulge are not born in super-clusters which then sink to the centre of the galaxy. This is because feedback efficiently disperses GMC after they turn several per cent of their mass into stars. In other words, most of the mass that reaches the nucleus does so in the form of gas. The Kennicutt–Schmidt law emerges naturally as a consequence of feedback balancing gravitational collapse, independent of the small-scale star formation microphysics. The same mechanisms that drive this relation in isolated galaxies, in particular radiation pressure from infrared photons, extend, with no fine-tuning, over seven decades in star formation rate (SFR) to regulate star formation in the most extreme starburst systems with densities ≳10⁴ M_⊙ pc⁻². This feedback also drives super-winds with large mass-loss rates; however, a significant fraction of the wind material falls back on to the discs at later times, leading to higher post-starburst SFRs in the presence of stellar feedback. This suggests that strong active galactic nucleus feedback may be required to explain the sharp cut-offs in SFR that are observed in post-merger galaxies.
We compare the results to those from simulations with no explicit resolution of GMC or feedback [‘effective equation-of-state’ (EOS) models]. We find that global galaxy properties are similar between EOS and resolved-feedback models. The relic structure and mass profile, and the total mass of stars formed in the nuclear starburst are quite similar, as is the morphological structure during and after mergers (tails, bridges, etc.). Disc survival in sufficiently gas rich mergers is similar in the two cases, and the new models follow the same scalings as derived for the efficiency of disc re-formation after a merger as derived from previous work with the simplified EOS models. While the global galaxy properties are similar between EOS and feedback models, subgalaxy-scale properties and the SFRs can be quite different: the more detailed models exhibit significantly higher star formation in tails and bridges (especially in shocks), and allow us to resolve the formation of super star clusters. In the new models, the star formation is more strongly time-variable and drops more sharply between close passages. The instantaneous burst enhancement can be higher or lower, depending on the details of the orbit and initial structural properties of the galaxies; first-passage bursts are more sensitive to these details than those at the final coalescence
Computer program applying Fourier transforms to the analysis of gamma spectral data
"August 1968.""MIT-3944-2."Includes bibliographical references (pages 86-87)GAMANL, a computer code for automatically identifying the peaks in a complex spectra and determining their centers and areas, is described. The principal feature of the method is a data smoothing technique employing Fourier transforms. The smoothing eliminates most of the random fluctuations without effecting the spectral resolution and makes identification of maxima using a zero slope criterion possible. Using the same Fourier transform with different constants it is possible with a second transformation to improve the spectral resolution. The computer program has been written in FORTRAN IV for the M.IT. IBM 360 model 65 computer and also for the Toshiba Electric Company G.E. 635 computer. The complete analysis of a 4096 channel spectrum containing one hundred twenty peaks requires about 75 seconds of computation time.United States Atomic Energy Commission contract AT(30-1)-394
The Development of the Angled-Deck Aircraft Carrier—Innovation and Adaptation
In the years immediately after World War II, three British innovations—the angled flight deck, steam catapult, and optical landing aid—enabled the modern aircraft carrier. How did the U.S. Navy take such quick advantage of them, and why were they not American innovations in the first place
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