6,921 research outputs found
Effects of breed type, silage harvest date and pattern of offering concentrates on intake, performance and carcass traits of finishing steers
peer-reviewedThe objective of this experiment was to investigate the effects and interactions of breed type, silage harvest date and pattern of offering concentrates on intake, performance and carcass traits of finishing steers. Seventy-two steers (36 Friesian and 36 beef cross) were blocked on weight within breed type and assigned to a pre-experimental slaughter group or to one of 4 dietary treatments in a 2 (breed type) 2 (early- or late- cut silage) 2 (flat rate or varied pattern of offering concentrates) factorial arrangement of treatments. The flat-rate feeding pattern was silage ad libitum plus 5 kg concentrates per head daily to slaughter. The varied feeding pattern was silage only for 79 days followed by concentrates ad libitum to slaughter. All animals were slaughtered together after 164 days when the groups on the two feeding patterns had consumed the same total quantity of concentrates. Friesians had a higher (P < 0.001) silage dry matter (DM) intake and a higher (P < 0.01) total DM intake than the beef crosses. Live-weight gain was similar for both breed types but the beef-cross animals had a higher (P < 0.001) kill-out proportion, higher (P < 0.01) carcass gain, and better (P < 0.001) carcass conformation than the Friesians. The beef-cross type also had a higher (P < 0.001) proportion of muscle and a lower (P < 0.001) proportion of bone in the carcass. Silage harvest date had no effect on silage or total DM intakes but the early-cut silage did result in higher (P < 0.01) carcass gain. Animals on the varied feeding pattern consumed less (P < 0.01) silage DM and less (P < 0.001) total DM than those on the flat rate feeding pattern. Live-weight gain and carcass gain were similar for the two feeding patterns. It is concluded that Friesians had a higher intake, but had lower carcass gain than the beef-cross type. Animals on the early-cut silage had higher carcass gain than those on the late-cut silage. The varied feeding pattern resulted in lower DM intake but efficiency of feed energy utilisation was similar for both feeding patterns. Interactions were generally not statistically significant
Feed intake pattern, behaviour, rumen characteristics and blood metabolites of finishing beef steers offered total mixed rations constituted at feeding or ensiling
peer-reviewedTwo experiments were undertaken. In Experiment 1, behaviour, intake pattern and
blood metabolites, were recorded for steers offered total mixed rations (TMR) based
on grass silage and concentrates, and constituted either at ensiling (E-TMR) or feedout
(F-TMR). Fourteen continental crossbred steers (mean starting weight 505 (s.d.
41.5) kg) were assigned to each of the following eight treatments: grass silage offered
ad libitum (SO), E-TMR diets constituted in approximate dry matter (DM) ratios of
grass:concentrates of 75:25 (EL), 50:50 (EM) and 25:75 (EH), F-TMR diets constituted
in approximate DM ratios of grass silage:concentrates of 75:25 (FL), 50:50 (FM)
and 25:75 (FH), and finally concentrates ad libitum (AL). Total DM intake increased
linearly (P < 0.001) and the time spent eating and ruminating decreased linearly
(P < 0.001) with increasing concentrate proportion. Animals on the F-TMR diets had
higher total DM intakes (P < 0.05) and plasma glucose (P < 0.05) and urea (P < 0.001)
concentrations than animals on the corresponding E-TMR diets. No effect of method
of feed preparation on intake pattern or behaviour was recorded. In Experiment 2,
four ruminally cannulated Holstein-Friesian steers of mean initial live weight 630 (s.d.
23.2) kg were used to evaluate rumen characteristics for four of the above diets (FL,
EL, FH and EH) in a 4 × 4 latin square design. Higher concentrate diets resulted in
lower rumen pH (P < 0.05), higher lactic acid (P < 0.001) and ammonia (P < 0.05)
concentrations and lower acetate:propionate (P < 0.05). F-TMR was associated with
a higher (P < 0.05) rumen volatile fatty acid concentration but no difference in other
rumen fermentation characteristics compared to E-TMR. Concentrate proportion and method of feed preparation had no effect (P > 0.05) on rumen pool sizes but animals
consuming the high concentrate diet had a faster (P < 0.05) rumen passage rate of
NDF than animals on the low concentrate diet.B. Cummins was in receipt of a Teagasc Walsh Fellowship
Who Does R&D and Who Patents?
This paper describes the construction of a large panel data set covering about 2600 firms in the U.S. manufacturing sector for up to twenty years which contains annual data on financial variables, employment, research and development expenditures, and aggregate patent applications. This data set is to be used in a larger study of R&D, inventive output and technological change. In the present paper we present preliminary results on the R&D and patenting behavior of the 1976 cross section of these firms. We find an elasticity of R&D with respect to sales of close to unity, with both very small and very large firms being slightly more R&D intensive than average. Because only 60% of the firms report R&D expenditures, we attempt to correct for selectivity bias and find that though the correction is small, it increases the estimated complementarity between capital intensity and R&D intensity. In exploring the relationship of the patenting activity of these firms to their contemporaneous R&D expenditures, we look with some care at the choice of econometric specifications since the discrete nature of the patents variable for our smaller firms may cause difficulties with the conventional log linear model. The choice of specification does indeed make a difference, and the negative binomial model, which is a Poisson-type model with a disturbance, is preferred. Substantively, we find a much larger output of patents per R&D dollar for the small firms, with a decreasing propensity to patent with size of R&D programs throughout the sample. However, this conclusion is highly tentative both because of its sensitivity to specification and choice of sample and also because we expect that errors in variables bias due to our focus on R&D and patent applications in a single year is far worse for the small firms.
Lie Superalgebras and the Multiplet Structure of the Genetic Code II: Branching Schemes
Continuing our attempt to explain the degeneracy of the genetic code using
basic classical Lie superalgebras, we present the branching schemes for the
typical codon representations (typical 64-dimensional irreducible
representations) of basic classical Lie superalgebras and find three schemes
that do reproduce the degeneracies of the standard code, based on the
orthosymplectic algebra osp(5|2) and differing only in details of the symmetry
breaking pattern during the last step.Comment: 34 pages, 9 tables, LaTe
Conservation characteristics of grass and dry sugar beet pulp co-ensiled after different degrees of mixing
peer-reviewedThe objective of this experiment was to quantify the effects of the degree of mixing of dry molassed sugar beet pulp (BP) with grass on silage conservation characteristics.
Herbage from a timothy (Phleum pratense) sward was precision chopped and treated with a formic acid based additive (3 l/t grass). Units of 50 kg grass, without or with 2.5kg BP were randomly allocated among four replicates on each of seven treatments. The treatments were (1) no BP (NONE), (2) BP evenly mixed through the grass (EVEN),
(3) BP evenly mixed through the lower 25 kg grass (LOWH), (4) BP evenly mixed through the lower 12.5 kg grass (LOWQ), (5) 0.625 kg BP mixed through the top 25 kg grass and 1.875 kg SBP mixed through the lower 25 kg grass (25/75), (6) BP placed in 0.5 kg layers beneath each 10 kg grass (LAYR), and (7) BP placed in a single layer under all of the grass (BOTM). Laboratory silos were filled and sealed, and stored at 15 °C for 163 days. Effluent was collected and weighed from each silo throughout the ensilage period.
At opening, silage composition and aerobic stability measurements were made. Total outflow of effluent was reduced (P<0.001) by the addition of BP; LAYR had a greater effect (P<0.001) than any of the other treatments. Effluent dry matter (DM) concentration was highest (P<0.05) for BOTM and lowest (P<0.01) for NONE. All treatments underwent similar lactic-acid dominant fermentations. Incorporation of BP with grass increased silage DM concentration (P<0.001), in vitro DM digestibility (P<0.05) and water soluble carbohydrate (P<0.001) concentration and reduced acid detergent fibre (P<0.001) concentration. Aerobic stability was similar across treatments and aerobic deterioration at 192 h was higher (P<0.05) for LOWQ, 25/75, LAYR and BOTM than for NONE. In conclusion, the incorporation of BP increased silage DM digestibility but had relatively little effect on fermentation or aerobic stability. Placing BP in layers gave the largest and most sustained restriction in effluent output.B. Cummins acknowledges receipt of a Walsh Fellowship provided by Teagasc
Generating-function method for tensor products
This is the first of two articles devoted to a exposition of the
generating-function method for computing fusion rules in affine Lie algebras.
The present paper is entirely devoted to the study of the tensor-product
(infinite-level) limit of fusions rules.
We start by reviewing Sharp's character method. An alternative approach to
the construction of tensor-product generating functions is then presented which
overcomes most of the technical difficulties associated with the character
method. It is based on the reformulation of the problem of calculating tensor
products in terms of the solution of a set of linear and homogeneous
Diophantine equations whose elementary solutions represent ``elementary
couplings''. Grobner bases provide a tool for generating the complete set of
relations between elementary couplings and, most importantly, as an algorithm
for specifying a complete, compatible set of ``forbidden couplings''.Comment: Harvmac (b mode : 39 p) and Pictex; this is a substantially reduced
version of hep-th/9811113 (with new title); to appear in J. Math. Phy
The effect of moving to East Village, the former London 2012 Olympic and Paralympic Games Athletes' Village, on mode of travel (ENABLE London study, a natural experiment)
Background
Interventions to encourage active modes of travel (walking, cycling) may improve physical activity levels, but longitudinal evidence is limited and major change in the built environment / travel infrastructure may be needed. East Village (the former London 2012 Olympic Games Athletes Village) has been repurposed on active design principles with improved walkability, open space and public transport and restrictions on residential car parking. We examined the effect of moving to East Village on adult travel patterns.
Methods
One thousand two hundred seventy-eight adults (16+ years) seeking to move into social, intermediate, and market-rent East Village accommodation were recruited in 2013–2015, and followed up after 2 years. Individual objective measures of physical activity using accelerometry (ActiGraph GT3X+) and geographic location using GPS travel recorders (QStarz) were time-matched and a validated algorithm assigned four travel modes (walking, cycling, motorised vehicle, train). We examined change in time spent in different travel modes, using multilevel linear regresssion models adjusting for sex, age group, ethnicity, housing group (fixed effects) and household (random effect), comparing those who had moved to East Village at follow-up with those who did not.
Results
Of 877 adults (69%) followed-up, 578 (66%) provided valid accelerometry and GPS data for at least 1 day (≥540 min) at both time points; half had moved to East Village. Despite no overall effects on physical activity levels, sizeable improvements in walkability and access to public transport in East Village resulted in decreased daily vehicle travel (8.3 mins, 95%CI 2.5,14.0), particularly in the intermediate housing group (9.6 mins, 95%CI 2.2,16.9), and increased underground travel (3.9 mins, 95%CI 1.2,6.5), more so in the market-rent group (11.5 mins, 95%CI 4.4,18.6). However, there were no effects on time spent walking or cycling
An investigation into CLIL-related sections of EFL coursebooks : issues of CLIL inclusion in the publishing market
The current ELT global coursebook market has embraced CLIL as a weak form of bilingual education and an innovative component to include in General English coursebooks for EFL contexts. In this paper I investigate how CLIL is included in ELT coursebooks aimed at
teenaged learners, available to teachers in Argentina. My study is based on the content analysis of four series which include a section advertised as CLIL-oriented. Results suggest that such sections are characterised by (1) little correlation between featured subject specific content and school curricula in L1, (2) oversimplification of contents, and (3) dominance of reading skills development and lower-order thinking tasks. Through this study, I argue that
CLIL components become superficial supplements rather than a meaningful attempt to promote weak forms of bilingual education
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