84,012 research outputs found
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
Full text linkFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
John Ferguson, Socrates. A Source Book compiled and by J. F. Londres, Macmillan
No full textBastaits M. John Ferguson, Socrates. A Source Book compiled and by J. F. Londres, Macmillan. In: L'antiquité classique, Tome 40, fasc. 2, 1971. pp. 778-780
A study of hereditary and nutritionally-induced muscular dystrophy in chicks and turkeys
No full textThe effects of Vitamin E, santoquin, methionine, arginine and unsaturated fat on the development of muscular dystrophy in avian species were studied. Attention was focused upon possible differences between hereditary and nutritionally-induced types of muscular dystrophy. In experiment 1, breast muscle from White Leghorn chocks fed a diet deficient in Vitamin E and containing 1% added arginine displayed the highest activity of succinic dehydrogenase, cytochrome c oxidase and was associated with high activity of glutamic-oxalacetic transaminase (GOT) and glycogen content. Feeding santoquin resulted in depressing the breast muscle succinic dehydrogenase activity at 2 weeks and the glycogen content at 5 weeks. Adequate vitamin E in the diet was related to the lowest heart rate at 2 weeks of age. In experiment 2, breast muscles from New Hampshire muscular dystrophy strain chicks fed diets deficient in both vitamin E and methionine with or without 1% added arginine displayed macroscopic evidence of muscular dystrophy, and had lower activity succinic dehydrogenase and GOT. However, leg muscle succinic dehydrogenase activity and glycogen content were higher on the same diet. Chicks maintained on a diet deficient in both vitamin E and methionine and containing 1% added arginine for 6 weeks, then fed the same diet but adequate in vitamin E for an additional 2 weeks, showed an elevation in the activity of succinic dehydrogenase and GOT in the breast muscle. In experiment 3, Broad Breasted Bronze turkey male poults fed a diet deficient in both vitamin E and methionine showed a decrease in the activity of succinic dehydrogenase, cytochrome c oxidase, GOT and glycogen content in the breast muscle. The activity of cytochrome c oxidase and GOT and glycogen level in the liver and serum aldolase were depressed in birds fed a diet deficient in vitamin E and methionine compared to those on a diet adequate in vitamin E and methionine. Serum GOT and liver succinic dehydrogenase activities were elevated in birds fed a diet deficient in vitamin E and methionine. The highest heart rate occurred in birds fed a diet deficient in vitamin E and methionine.
Role of immunocompetence, immunosuppression and social stress in susceptibility of chickens to Rous sarcoma
No full textVita.A series of six experiments involving a total of 1627 birds from four genetic lines known to differ in their resistance to Rous sarcoma virus (RSV) were conducted. In experiment one, the relationship between transplantation and tumor immunity was studied. Five day-old male chicks of the RSV-susceptible incross line (IC) were given random skin allografts which were scored for survival and feather growth at weekly intervals. Birds which showed either rapid graft rejection by four weeks postgrafting or profusely feathered accepted grafts by seven weeks postgrafting, were challenged with RSV when they reached eight weeks of age. Resulting tumors were scored at weekly intervals through 12 weeks postchallenge and a daily record of mortality was maintained. Mortality and mean survival time (MST) in birds accepting skin allografts were 94.92% and 41.58 �� 8.08 days compared to 66.67% and 24.49 �� 4.415 days for birds rejecting skin allografts, respectively. These differences in mortality and MST were highly significant (P (less than or equal to sign) 0.01). Also, mean tumor scores were consistently higher in birds accepting skin allografts than those rejecting their grafts. This similarity in the pattern of response of birds to skin allografting and to subsequent RSV challenge strongly suggests a relationship between transplantation and tumor immunity. Additionally, these results indicate that the response of birds to skin allografting may provide an useful measure of bird's immunocompetence to Rous sarcoma.
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Design and Analysis of Double Spin Qubits Integrated on Ultra-thin Silicon-on-insulator
No full textThis paper presents the design and analysis of a Sibased integrated spin qubit system on ultrathin silicon-oninsulator. A new design layout is proposed for the double spin qubits co-integrated with a single electron electrometer, a ?-ESR and a nanomagnet. Three dimensional FEM simulations are performed to calculate the capacitance parameters among quantum dots and other building blocks for the proposed structure. Monte Carlo based single electron circuit simulation is then performed to demonstrate single electron transfer operation. The single electron transfer characteristics are analyzed and used to optimize the system structural parameters and layout
The relation of lysine level during the growing period to sexual maturity and subsequent performance of broiler-breeders
No full textTwo studies were carried out to determine the effects of varying the lysine level and the feeding regimes of broiler-breeder replacement pullets during the growing season on body weights, delay in sexual maturity and subsequent reproductive performance of the pullets. The feeding of .32 to .64% lysine rations to broiler-breeder pullets from the beginning of the 7th through the 22nd or 26th week resulted in pullets that were improved in performance over pullets that were fed rations containing .70 or .75% lysine for the same periods of time (full-fed). The pullets fed the low-lysine rations weighed less, were delayed in sexual maturity, were increased in egg production and were decreased in the number of small eggs laid at the beginning of the laying season when compared to the full-fed pullets. ..
Measurement of the time-dependent CP asymmetry in B0 -> J/ψ KS0 decays
Full text linkThis Letter reports a measurement of the CP violation observables SJ/ψK0S and CJ/ψK0S in the decay channel B0→J/ψK0S performed with 1.0 fb−1 of pp collisions at s√=7 TeV collected by the LHCb experiment. The fit to the data yields SJ/ψK0S=0.73±0.07(stat)±0.04(syst) and CJ/ψK0S=0.03±0.09(stat)±0.01(syst). Both values are consistent with the current world averages and within
expectations from the Standard Model
Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis
Full text linkMultiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
Full text linkThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
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