59,247 research outputs found
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe 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
The Inheritance of Reading Disability : Evidence from a Twin Study
No full textviii, 21 p.Reading disability is a major educational concern to students, parents, and educators. Because it may affect up to 10-15% of school-age children with average IQ and ample educational opportunity (Defries, Fulker, & LaBuda, 1987), research on the etiology of the disorder is clearly warranted. Results of the present study provide evidence for a genetic etiology of reading disability. Seventy-five identical twin pairs and fifty-nine fraternal twin pairs in which at least one member had evidence of reading problems in school were administered a battery of school achievement and psychometric tests. Scores from the Reading Recognition, Reading Comprehension, and Spelling subtests of the Peabody Individual Achievement Test were subjected to principal component analysis and used to create individual composite reading scores. The more severely affected pair member with evidence of reading problems at school was the proband, while his/her twin was designated the cotwin. It was hypothesized that the identical and fraternal cotwins' composite scores would regress differentially toward the mean of the unselected population to the extent that reading disability is heritable. Multiple regression analyses of the twin data (Defries & Fulker, 1985) provided evidence for a significant genetic etiology of reading disability. Approximately 50% of the reading deficit of probands may be due to heritable influences. Application of extended multiple regression models could give improved risk estimates, facilitate early diagnosis, and provide validity tests for suggested subtypes of reading disability.
Multivariate Parent-Offspring Analyses of Specific Cognitive Abilities:Nature, Nurture, and the Transition to Early Adolescence
No full textDuring the last few decades, family, twin, and adoption designs havebeen used to assess the genetic and environmental etiologies of specificcognitive abilities (SCA). The largest family study of SCA was the HawaiiFamily Study of Cognition, which included test data from 1,816 intactnuclear families. Measures of parent-offspring resemblance can only beconsidered via upper-bound estimates of heritability. Thus, family studiescan provide conclusive evidence for the familiarity of a trait, but not forits genetic etiology. In contrast, results obtained from twin studies canprovide estimates of heritability. This chapter discusses the results ofmultivariate genetic analyses of Colorado Adoption Project (CAP) parent-offspringdata at seven and twelve years of age, and compares them tothose obtained by Rice et al. (1989) when the CAP children were onlyfour years of age. The etiologies of individual differences for each of thefour measures — verbal, spatial, perceptual speed, and memory — andtheir covariation were assessed by fitting a parent-offspring multivariateconditional path model to CAP specific cognitive abilities data
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst 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)
Measurement of the time-dependent CP asymmetry in B0 -> J/ψ KS0 decays
No full textThis 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
Letter from J. E. Gavin to Louis C. Cramton regarding Sale of Bright Angel Trail
No full textLetter from J. E. Gavin to Louis C. Cramton regarding the Bright Angel Trail controversy, including newspaper clipping
Acute Ethanol Administration Rapidly Increases Phosphorylation of Conventional Protein Kinase C in Specific Mammalian Brain Regions in Vivo
No full textBackground
Protein kinase C (PKC) is a family of isoenzymes that regulate a variety of functions in the central nervous system including neurotransmitter release, ion channel activity, and cell differentiation. Growing evidence suggests that specific isoforms of PKC influence a variety of behavioral, biochemical, and physiological effects of ethanol in mammals. The purpose of this study was to determine whether acute ethanol exposure alters phosphorylation of conventional PKC isoforms at a threonine 674 (p-cPKC) site in the hydrophobic domain of the kinase, which is required for its catalytic activity.
Methods
Male rats were administered a dose range of ethanol (0, 0.5, 1, or 2 g/kg, intragastric) and brain tissue was removed 10 minutes later for evaluation of changes in p-cPKC expression using immunohistochemistry and Western blot methods.
Results
Immunohistochemical data show that the highest dose of ethanol (2 g/kg) rapidly increases p-cPKC immunoreactivity specifically in the nucleus accumbens (core and shell), lateral septum, and hippocampus (CA3 and dentate gyrus). Western blot analysis further showed that ethanol (2 g/kg) increased p-cPKC expression in the P2 membrane fraction of tissue from the nucleus accumbens and hippocampus. Although p-cPKC was expressed in numerous other brain regions, including the caudate nucleus, amygdala, and cortex, no changes were observed in response to acute ethanol. Total PKC? immunoreactivity was surveyed throughout the brain and showed no change following acute ethanol injection
Measurement of the branching fraction
No full textThe B
0
s
→ J/ψK
0
S
branching fraction is measured in a data sample corresponding to 0.41 fb−1
of integrated luminosity collected with the LHCb detector at the LHC. This channel is sensitive to
the penguin contributions affecting the sin 2β measurement from B
0
→ J/ψK
0
S
. The time-integrated
branching fraction is measured to be B(B
0
s
→ J/ψK
0
S
) = (1.83±0.28)×10−5
. This is the most precise
measurement to date
Letter from J. R. Eakin to Arthur G. Ringland
No full textLetter (copy) from J. R. Eakin to Arthur C. Ringland about the alignment of 40 acres near the Buggeln ranch
Diary of C. J. Sanders
No full textDiary - This document is the personal diary of Constance Jukes Sanders, daughter of Gilbert E. Sanders, Superintendent of the Northwest Mounted Police 1905-1908. The diary begins on August 27, 1910, and ends April 6, 1911. Diary entries include daily activities of C. J. Sanders during her nineteenth and twentieth years, while living in Athabasca Landing with her parents. C. J. spent her days doing housework at the family's home, and often taught Sunday School at the local church. A favourite pastime was having friends over to play bridge in the evening, or riding ponies during the daytime. Church was a big part of the family's week. The women also spent a lot of time cooking, cleaning and sewing. C. J. took a boat over to Europe with her mother and father just before Christmas in 1910. She was very seasick during the trip. While in Europe they visited family and friends in England, Ireland and France (45 pages
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