41,039 research outputs found
Measurement of the branching fractions for B--> D(*)+pi(-)l(-)(nu)over-bar(l) and (B)over-bar(0)-> D-(*)0 pi(+)l(-)(nu)over-bar(l)
No full textWe report on a measurement of the branching fractions for B- --> D(*)+ pi(-)l(-)(nu) over bar (l) and (B) over bar (0) --> D-(*)0 pi(+)l(-)(nu) over bar (l) with 275 x 10(6) B (B) over bar events collected at the Y(4S) resonance with the Belle detector at KEKB. Events are tagged by fully reconstructing one of the B mesons in hadronic modes. We obtain B(B- --> D(+)pi(-)l(-)(nu) over bar (l)) = (0.54 +/- 0.07 (stat) +/- 0.07(syst) +/- 0.06(BR)) x 10(-2), B(B- --> D*+pi(-) l(-) (nu) over bar (l)) (0.67 +/- 0.11 (stat) +/- 0.09(syst) +/- 0.03(BR)) x 10(-2), B((B) over bar (0) --> D(0)pi(+)l(-) (nu) over bar (l)) = (0.33 +/- 0.06(stat) +/- 0.06(syst) +/- 0.03(BR)) x 10(-2), B((B) over bar (0) -->D(*0)pi(+)l(-)(nu) over bar (l)) = (0.65 +/- 0.12(stat) +/- 0.08(syst) +/- 0.05(BR)) x 10(-2), where the third error comes from the error on (B) over bar --> D((*))l(-)(nu) over bar (l) decays. Contributions from B-0 --> D(*+)l(-)(nu) over bar (l) decays are excluded in the measurement of (B) over bar (0) --> D(0)pi(+)l-(nu) over bar (l).Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)0ARTICLE5null7
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
D-Spaces and L-Special Trees
No full textThis dissertation concerns D-spaces and set-theoretic trees. A topological space, X, is a D-space if for every neighbornet of the space there is a closed, discrete set from X whose images in the neighbornet are a cover for X. A set-theoretic tree is a poset where for any element the set of its predecessors is well-ordered.
In this dissertation it is shown that certain L-special trees are D-spaces and some of them are hereditarily so.In particular, let L=[0,1]α with α a countable ordinal be given the lexicographic order. For α \u3c ω+1, the author shows that any L-special tree is hereditarily a D-space. For certain α with ω \u3c α \u3c ω1 the author shows that any L-special tree is a D-space. For the remaining countable ordinals α, the current progress is shown
Lipid-soluble Vitamins A, D, and E in HIV-Infected Pregnant women in Tanzania.
No full textThere is limited published research examining lipid-soluble vitamins in human immunodeficiency virus (HIV)-infected pregnant women, particularly in resource-limited settings. This is an observational analysis of 1078 HIV-infected pregnant women enrolled in a trial of vitamin supplementation in Tanzania. Baseline data on sociodemographic and anthropometric characteristics, clinical signs and symptoms, and laboratory parameters were used to identify correlates of low plasma vitamin A (<0.7 micromol/l), vitamin D (<80 nmol/l) and vitamin E (<9.7 micromol/l) status. Binomial regression was used to estimate risk ratios and 95% confidence intervals. Approximately 35, 39 and 51% of the women had low levels of vitamins A, D and E, respectively. Severe anemia (hemoglobin <85 g/l; P<0.01), plasma vitamin E (P=0.02), selenium (P=0.01) and vitamin D (P=0.02) concentrations were significant correlates of low vitamin A status in multivariate models. Erythrocyte Sedimentation Rate (ESR) was independently related to low vitamin A status in a nonlinear manner (P=0.01). The correlates of low vitamin D status were CD8 cell count (P=0.01), high ESR (ESR >81 mm/h; P<0.01), gestational age at enrollment (nonlinear; P=0.03) and plasma vitamins A (P=0.02) and E (P=0.01). For low vitamin E status, the correlates were money spent on food per household per day (P<0.01), plasma vitamin A concentration (nonlinear; P<0.01) and a gestational age <16 weeks at enrollment (P<0.01). Low concentrations of lipid-soluble vitamins are widely prevalent among HIV-infected women in Tanzania and are correlated with other nutritional insufficiencies. Identifying HIV-infected persons at greater risk of poor nutritional status and infections may help inform design and implementation of appropriate interventions
Inherent radioresistance of head and neck squamous cell carcinoma cells: principal component analysis identifies cellular senescence as a crucial driver
No full textInherent radioresistance of head and neck squamous cell carcinoma cells: principal component analysis identifies cellular senescence as a crucial driver
No full textSpontaneous-search method and short-time dynamics: applications to the Domany-Kinzel cellular automaton
No full textThe one-dimensional Domany-Kinzel cellular automaton is investigated by two numerical approaches: (i) the spontaneous-search method, which is a method appropriated for a search of criticality; (ii) short-time dynamics. Both critical frontiers of the system are investigated, namely, the one separating the frozen and active phases, as well as the critical line determined by damage spreading between two cellular automata, that splits the active phase into the nonchaotic and chaotic phases. The efficiency of the spontaneous-search method is established herein through a precise estimate of both critical frontiers, and in addition to that, it is shown that this method may also be used in the determination of the critical exponent ν ⊥ . Using the critical frontiers obtained, other exponents are estimated through short-time dynamics. It is verified that the critical exponents of both critical frontiers fall in the universality class of directed percolation. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 200805.70.Ln Nonequilibrium and irreversible thermodynamics, 64.60.Ht Dynamic critical phenomena, 64.60.-i General studies of phase transitions,
- …
