413 research outputs found
Index Selection in Terminal Sires Improves Early Lamb Growth
The use of terminal sires (TS) for crossbreeding is integral to the UK sheep industry where approximately 71% of market lambs are sired by TS rams. Early growth of these crossbred lambs affects profitability. The objectives of this study were i) to evaluate the effectiveness of index selection among TS on BW and ADG of their crossbred offspring; and ii) to compare the efficacy of that selection within TS breeds. The most widely used TS breeds in the United Kingdom are Charollais, Suffolk, and Texel. These participated in sire referencing schemes in which they were evaluated on a lean growth index designed to increase carcass lean weight at a given age. From 1999 to 2002, approximately 15 high and 15 low lean growth index rams per breed (93 in total, differing in index on average by 4.6 SD) were selected from within their sire referencing schemes and mated to Welsh and Scottish Mule ewes. Their crossbred offspring were reared commercially on 3 experimental farms in England, Scotland, and Wales. A total of 6,515 lambs were born between 2000 and 2003. Lambs were weighed at birth (BWT), 5 wk (5WT), and 10 wk (10WT), and their ADG from birth to 10 wk was calculated. Lambs sired by high index rams were on average, across breeds, heavier at all ages (P \u3c 0.01) with 0.07 ± 0.03, 0.3 ± 0.1, and 0.4 ± 0.1 kg greater BWT, 5WT, and 10WT, respectively. Their ADG was 5.1 ± 1.9 g/d greater than low-index-sired lambs (P \u3c 0.01). Suffolk-sired lambs were on average heavier at all ages, with greater ADG, whereas Charollais-sired lambs were lightest with smallest ADG. Overall, there was no significant interaction between sire index and sire breed (P \u3e 0.10). Within Suffolk-sired lambs, there was little difference between high and low index sires for the traits studied (P \u3e 0.3). High and low index Charollais-sired lambs differed in BWT (0.09 ± 0.04 kg) and 5WT (0.3 ± 0.1 kg), and Texel-sired lambs differed in 5WT (0.5 ± 0.1 kg), 10WT (0.9 ± 0.2 kg), and ADG (10.2 ± 3.3 g/d; P \u3c 0.01). Lambs from Scottish Mule dams were heavier, with greater ADG, than lambs born to Welsh Mules (P \u3c 0.01). Lambs reared in Scotland were heavier at all ages (P \u3c 0.01). The results suggest that using index selection in TS can improve the growth of their commercial offspring reared on grass
Index Selection in Terminal Sires Improves Lamb Performance at Finishing
Lamb meat is often perceived by consumers as fatty, and consumption has decreased in recent decades. A lean growth index was developed in the UK for terminal sire breeds to increase carcass lean content and constrain fat content at a constant age end point. The purposes of this study were 1) to evaluate the effects of index selection of terminal sires on their crossbred offspring at finishing and 2) to evaluate its effectiveness within terminal sire breeds. Approximately 70% of lambs marketed in the UK have been sired by rams of breeds typically thought of as specialized terminal sires. The most widely used are Charollais, Suffolk, and Texel. These breeds participated in sire referencing schemes from the early 1990s by sharing rams among flocks selected on the lean growth index. From 1999 to 2002 approximately 15 “high” and 15 “low” lean growth index score rams were selected from within their sire referencing schemes and mated to Welsh and Scottish Mule ewes. Their crossbred offspring were commercially reared on 3 farms in the UK. Lambs were finished to an estimated 11% subcutaneous fat by visual evaluation. At finishing, lambs were weighed, ultrasonically scanned, and assessed for condition score and conformation. Records were obtained for 6,356 lambs on finishing BW (FWT), ultrasonic muscle depth (UMD), ultrasonic fat depth, overall condition score (OCS), and conformation of gigot, loin, and shoulder. Ultrasonic fat depth was log transformed (logUFD) to approach normality. High-index-sired lambs were heavier at finishing (1.2 ± 0.2 kg) with thicker UMD (0.7 ± 0.2 mm) and less logUFD (0.08 ± 0.01 mm; P \u3c 0.05). There were no differences in OCS or conformation based on the sire index or breed (P \u3e 0.08). Suffolk-sired lambs were heavier than Charollais (1.0 ± 0.3 kg), which were heavier than Texel (0.9 ± 0.3 kg; P \u3c 0.001). Texel-sired lambs had thicker UMD than Charollais (0.7 ± 0.2 mm; P \u3c 0.001) but were not different than Suffolk. Charollais-sired lambs had greater logUFD than both Texel (0.098 ± 0.016 mm) and Suffolk (0.061 ± 0.017 mm) sired lambs (P \u3c 0.001). Within a breed, high- and low-index-sired lambs differed in performance with the exceptions of FWT and UMD in Suffolks. Index selection produced heavier and leaner lambs at finishing. Producers have flexibility in choosing the terminal sire that best fits their production system
Stabilization of d-Band Ferromagnetism by Hybridization with Uncorrelated Bands
We investigate the influence of s-d or p-d hybridization to d-band
ferromagnetism to estimate the importance of hybridization for the magnetic
properties of transition metals. To focus our attention to the interplay
between hybridization and correlation we investigate a simple model system
consisting of two non-degenerated hybridized bands, one strongly correlated,
the other one quasi-free. To solve this extended Hubbard model, we apply simple
approximations, namely SDA and MAA, that, concerning ferromagnetism in the
single-band model, are known to give qualitatively satisfactory results. This
approach allows us to discuss the underlying mechanism, by which d-band
ferromagnetism is influenced by the hybridization on the basis of analytical
expressions. The latter clearly display the order and the functional
dependencies of the important effects. It is found, that spin-dependent
inter-band particle fluctuations cause a spin-dependent band shift and a
spin-dependent band broadening of the Hubbard bands. The shift stabilizes, the
broadening tends to destabilize ferromagnetism. Stabilization requires
relatively high band distances and small hybridization matrix elements.
Super-exchange and RKKY coupling are of minor importance.Comment: 9 pages, 7 figures, accepted for PR
3-Year follow-up of a single magnetically controlled growing rod with contralateral gliding system and apical control for early onset scoliosis
STUDY DESIGN: Two-center retrospective cohort study. OBJECTIVE: The aim of this study is to investigate the clinical effectiveness and safety of the MCGR hybrid in terms of spinal growth, 3D correction, balance, and complications. The magnetic-controlled growing-rod (MCGR) growth instrumentation method has gained popularity for early onset scoliosis (EOS) treatment in the past years due to the non-invasiveness of the subsequent interval elongation procedures. To improve 3D correction and reduce the costs, we combined a single concave MCGR with a sliding rod on the convex side to control the apex. METHODS: A retrospective cohort study of 18 EOS children with an average 3-year follow-up (range 2.0-3.7) from two European spine centers treated with the single MCGR hybrid concept; 14 primary and 4 conversion cases. The primary and conversion cases were both evaluated preoperatively, postoperatively, 1 year, 2 years, and last follow-up. RESULTS: Mean age was 9.9 (SD ± 2.9 years). The average frontal Cobb angle was reduced from mean 65° to 30° postoperatively, and had increased to 37° at latest follow-up. Rotation of the apical vertebra improved from mean 27° to 20° postoperatively which was partially lost to 23°. Kyphosis and lordosis both increased by an average of 5° during the time of follow-up. Spinal balance was improved. The post-implantation T1-S1 spine growth rate averaged 10 mm/year at last follow-up. There were 13 implant-related complications in 6 out of 18 patients. No screw pull-outs and nor surgical site infections were registered. CONCLUSIONS: This is the first medium-term results of a single MCGR hybrid construct. Maintenance of correction and growth are reasonable, and the complication rate is relatively low as compared to bilateral MCGR application. LEVEL OF EVIDENCE: III
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Measurement of B(B-->X_s {\gamma}), the B-->X_s {\gamma} photon energy spectrum, and the direct CP asymmetry in B-->X_{s+d} {\gamma} decays
The photon spectrum in B --> X_s {\gamma} decay, where X_s is any strange
hadronic state, is studied using a data sample of (382.8\pm 4.2) \times 10^6
e^+ e^- --> \Upsilon(4S) --> BBbar events collected by the BABAR experiment at
the PEP-II collider. The spectrum is used to measure the branching fraction B(B
--> X_s \gamma) = (3.21 \pm 0.15 \pm 0.29 \pm 0.08)\times 10^{-4} and the
first, second, and third moments = 2.267 \pm 0.019 \pm 0.032 \pm
0.003 GeV,, )^2> = 0.0484 \pm 0.0053 \pm 0.0077 \pm
0.0005 GeV^2, and )^3> = -0.0048 \pm 0.0011 \pm 0.0011
\pm 0.0004 GeV^3, for the range E_\gamma > 1.8 GeV, where E_{\gamma} is the
photon energy in the B-meson rest frame. Results are also presented for
narrower E_{\gamma} ranges. In addition, the direct CP asymmetry A_{CP}(B -->
X_{s+d} \gamma) is measured to be 0.057 \pm 0.063. The spectrum itself is also
unfolded to the B-meson rest frame; that is the frame in which theoretical
predictions for its shape are made.Comment: 37 pages, 19 postscript figures, submitted to Phys. Rev. D. No
analysis or results have changed from previous version. Some changes to
improve clarity based on interactions with Phys. Rev. D referees, including
one new Figure (Fig. 13), and some minor wording/punctuation/spelling
mistakes fixe
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Precise Measurement of the e+ e- --> pi+ pi- (gamma) Cross Section with the Initial-State Radiation Method at BABAR
A precise measurement of the cross section of the process
from threshold to an energy of 3GeV is obtained
with the initial-state radiation (ISR) method using 232fb of data
collected with the BaBar detector at center-of-mass energies near
10.6GeV. The ISR luminosity is determined from a study of the leptonic process
, which is found to agree with the
next-to-leading-order QED prediction to within 1.1%. The cross section for the
process is obtained with a systematic uncertainty
of 0.5% in the dominant resonance region. The leading-order hadronic
contribution to the muon magnetic anomaly calculated using the measured
cross section from threshold to 1.8GeV is .Comment: 58 pages, 56 figures, to be submitted to Phys. Rev.
Cross Sections for the Reactions e+e- --> K+ K- pi+pi-, K+ K- pi0pi0, and K+ K- K+ K- Measured Using Initial-State Radiation Events
We study the processes e+e- --> K+ K- pi+pi-gamma, K+ K- pi0pi0gamma, and K+
K- K+ K-gamma, where the photon is radiated from the initial state. About
84000, 8000, and 4200 fully reconstructed events, respectively, are selected
from 454 fb-1 of BaBar data. The invariant mass of the hadronic final state
defines the \epem center-of-mass energy, so that the K+ K- pi+pi- data can be
compared with direct measurements of the e+e- --> K+ K- pi+pi- reaction. No
direct measurements exist for the e+e- --> K+ K-pi0pi0 or e+e- --> K+ K-K+ K-
reactions, and we present an update of our previous result with doubled
statistics. Studying the structure of these events, we find contributions from
a number of intermediate states, and extract their cross sections. In
particular, we perform a more detailed study of the e+e- --> phi(1020)pipigamma
reaction, and confirm the presence of the Y(2175) resonance in the phi(1020)
f0(980) and K+K-f0(980) modes. In the charmonium region, we observe the J/psi
in all three final states and in several intermediate states, as well as the
psi(2S) in some modes, and measure the corresponding product of branching
fraction and electron width.Comment: 35 pages, 42 figure
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