886 research outputs found
Co-transport-induced instability of membrane voltage in tip-growing cells
A salient feature of stationary patterns in tip-growing cells is the key role
played by the symports and antiports, membrane proteins that translocate two
ionic species at the same time. It is shown that these co-transporters
destabilize generically the membrane voltage if the two translocated ions
diffuse differently and carry a charge of opposite (same) sign for symports
(antiports). Orders of magnitude obtained for the time and lengthscale are in
agreement with experiments. A weakly nonlinear analysis characterizes the
bifurcation
Muscling selection in swine and its effect on carcass traits
We are attempting to develop a well-muscled line of Durocs by selecting for minimum back fat and maximum loin eye area as estimated by the Anscan and to form a control line by randomly selecting from the same base population. The lines will be compared for performance and carcass traits, including incidence of pale soft exudative carcasses. Expected and realized heritability estimates for carcass traits will be calculated.; Swine Day, Manhattan, KS, November 2, 197
Selection for muscling in swine and its effect on carcass traits
Line differences in weight, litter size at different ages, and in age, loin eye area, and backfat thickness of pigs (adjusted to 200 pounds live weight) were not significant. Sex differences in weight and backfat thickness were significant. Dam groups of progeny differed significantly (P\u3c.0l) in-weights at birth and at 14 and 28 days old and in age, loin eye area, and backfat thickness adjusted to 220 pounds live weight. Hams produced by barrows in the select line were significantly (P\u3c.0l) darker and firmer than those from barrows in the control line.; Swine Day, Manhattan, KS, November 14, 197
Muscling selection in swine and its effect on carcass traits
Pigs farrowed in May, 1972, were the first born in the select and control lines. Performances of animals in the two lines were essentially the same. However, ham firmness and color differed significantly (P\u3c0.0l) between lines, with those in the select line firmer and darker than those from the control line.; Swine Day, Manhattan, KS, November, 197
Effects of adding saturated fat to diets with sorghum-based dried distillers grains with solubles on growth performance and carcass characteristics in finishing pigs
Two experiments were conducted to determine the effects of adding sources of saturated fat to diets with sorghum-based dried distillers grains with solubles (DDGS). For Exp. 1, 112 barrows (initially 140 lb) were used in a 69-d growth assay with 7 pigs per pen and 4 pens per treatment. Treatments were a corn-soybean meal-based control and diets having 40% sorghum-based DDGS (U.S. En-ergy Partners, Russell, KS) without and with 5% added tallow or palm oil. Feed and water were consumed on an ad libitum basis until pigs were slaughtered (average BW 283 lb) to allow collection of carcass data and jowl samples. Fatty acid composition of jowl samples was used to calculate iodine value (IV) as an indicator of carcass fat firmness. Overall (d 0 to 69), the corn-soybean control supported greater ADG and ADFI (P 0.9) compared with the DDGS treatments. Adding 5% beef tallow and palm oil to diets with DDGS improved overall F/G (P 0.14). Changes in IV indicated softer fat in pigs fed DDGS (P 0.14) compared with DDGS treatments. Adding fat sources to diets with DDGS tended to improve (P < 0.06) overall F/G, and coconut oil improved F/G compared with stearic acid (P < 0.001). Pigs fed the control diet had greater (P < 0.05) HCW than pigs fed the DDGS treatments. Pigs fed the control diet had lower IV and greater firmness score than pigs fed diets with added DDGS (P < 0.02). Adding fat sources to diets with DDGS improved these estimates of carcass firmness and tip to tip distance for suspended bellies (P < 0.001); coconut oil had a much greater effect than stearic acid (P < 0.001). In conclusion, adding beef tallow, palm oil, and coconut oil to diets with 40% DDGS improved efficiency of gain in finishing pigs. However, only coconut oil restored carcass firmness to levels at or above a corn-soybean diet without DDGS
Influence of duration of dietary vitamin E supplementation on swine growth performance and carcass quality
Supplementing medium-lean genotype pigs with supranutritional concentrations of dietary vitamin E (91 IU d-a-tocopheryl acetate/lb of feed) for as long as 70 d during the finishing phase was not effective in improving swine performance, feeding characteristics, and 24 h loin muscle quality. However, lower carcass temperatures obtained by spray chilling pork sides at O°C versus 4.4°C had a beneficial effect on 24 h carcass quality by improving marbling and lean firmness scores and reducing loin muscle moisture exudate. Overall, 24 h pork carcass quality was impacted more by chill rate than dietary vitamin E supplementation.; Swine Day, Manhattan, KS, November 19, 199
Influence of dietary lysine on growth performance of high-lean growth gilts fed from 160 to 300 lb
One-hundred eight high-lean growth gilts (159.6 lb) were used to determine the
dietary lysine requirement to optimize
growth performance from 160 to 300 lb.
The experiment was designed as a randomized
complete block, with initial weight serving as the blocking factor. Six dietary treatments were used, ranging from .44 to
.94% digestible lysine (.59 to 1.16% total
lysine). Pigs were housed in pens of three,
with six replicate pens/treatment. Pig
weights and feed disappearance were collected
weekly to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (F/G). Average daily gain increased from 160 to 230 lb, from 230 to 300 lb, and from 160 to 300 lb. Average daily feed intake was not influenced by dietary treatment. The gilts consumed 6.47, 6.65, and 6.56 lb/day from 160 to 230, from 230 to 300, and from 160 to 300 lb, respectively. Thus, F/G improved linearly from 160 to 230 lb and quadratically from 230 to 300 and from 160 to 300 lb as a function of increased ADG. Lysine intake was increased linearly for all three weight periods as digestible lysine increased in the diet. The data from this experiment suggest that high-lean growth gilts requires at least 26 g/d of lysine from 160 to 230 and from 230 to 300 lb. Thus, matching nutrition with genetics is essential to optimize both rate and efficiency of gain
Nonparametric relevance-shifted multiple testing procedures for the analysis of high-dimensional multivariate data with small sample sizes
<p>Abstract</p> <p>Background</p> <p>In many research areas it is necessary to find differences between treatment groups with several variables. For example, studies of microarray data seek to find a significant difference in location parameters from zero or one for ratios thereof for each variable. However, in some studies a significant deviation of the difference in locations from zero (or 1 in terms of the ratio) is biologically meaningless. A relevant difference or ratio is sought in such cases.</p> <p>Results</p> <p>This article addresses the use of relevance-shifted tests on ratios for a multivariate parallel two-sample group design. Two empirical procedures are proposed which embed the relevance-shifted test on ratios. As both procedures test a hypothesis for each variable, the resulting multiple testing problem has to be considered. Hence, the procedures include a multiplicity correction. Both procedures are extensions of available procedures for point null hypotheses achieving exact control of the familywise error rate. Whereas the shift of the null hypothesis alone would give straight-forward solutions, the problems that are the reason for the empirical considerations discussed here arise by the fact that the shift is considered in both directions and the whole parameter space in between these two limits has to be accepted as null hypothesis.</p> <p>Conclusion</p> <p>The first algorithm to be discussed uses a permutation algorithm, and is appropriate for designs with a moderately large number of observations. However, many experiments have limited sample sizes. Then the second procedure might be more appropriate, where multiplicity is corrected according to a concept of data-driven order of hypotheses.</p
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