3,591 research outputs found

    08/22/1948 Letter from the Boston Herald Traveler Corporation

    Get PDF
    Letter from Charles F. Collins, Herald Staff of the Boston Herald Traveler Corporation, to Louis-Philippe Gagné.https://digitalcommons.usm.maine.edu/fac-lpg-letters-1948-07-12/1011/thumbnail.jp

    Dispersion Relations and Rescattering Effects in B Nonleptonic Decays

    Get PDF
    Recently, the final state strong interactions in nonleptonic B decays were investigated in a formalism based on hadronic unitarity and dispersion relations in terms of the off-shell mass squared of the BB meson. We consider an heuristic derivation of the dispersion relations in the mass variables using the reduction LSZ formalism and find a discrepancy between the spectral function and the dispersive variable used in the recent works. The part of the unitarity sum which describes final state interactions is shown to appear as spectral function in a dispersion relation based on the analytic continuation in the mass squared of one final particles. As an application, by combining this formalism with Regge theory and SU(3) flavour symmetry we obtain constraints on the tree and the penguin amplitudes of the decay B0π+πB^0\to \pi^+\pi^-.Comment: 17 pages, Latex, 2 figure

    Genetic relatedness of infecting and reinfecting respiratory syncytial virus strains identified in a birth cohort from rural Kenya

    Get PDF
    Background: Respiratory syncytial virus (RSV) reinfects individuals repeatedly. The extent to which this is a consequence of RSV antigenic diversity is unclear. Methods: Six-hundred thirty-five children from rural Kenya were closely monitored for RSV infection from birth through 3 consecutive RSV epidemics. RSV infections were identified by immunofluorescence testing of nasal washing samples collected during acute respiratory illnesses, typed into group A and B, and sequenced in the attachment (G) protein. A positive sample separated from a previous positive by ≥14 days was defined as a reinfection a priori. Results: Phylogenetic analysis was undertaken for 325 (80%) of 409 identified infections, including 53 (64%) of 83 reinfections. Heterologous group reinfections were observed in 28 episodes, and homologous group reinfections were observed in 25 episodes; 10 involved homologous genotypes, 5 showed no amino acid changes, and 3 were separated by 21–24 days and were potentially persistent infections. The temporal distribution of genotypes among reinfections did not differ from that of single infections. Conclusions: The vast majority of infection and reinfection pairs differed by group, genotype, or G amino acid sequence (ie, comprised distinct viruses). The extent to which this is a consequence of immune memory of infection history or prevalent diversity remains unclear

    Results of the Cooperative Uniform Soybean Tests, 1947 Part I. North Central States

    Get PDF
    United States Department of Agriculture, Agricultural Research Administration; Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forage Crops and Diseases Cooperating with State Agricultural Experiment Station

    Religious Identity, Religious Attendance, and Parental Control

    Full text link
    Using a national sample of adolescents aged 10–18 years and their parents (N = 5,117), this article examines whether parental religious identity and religious participation are associated with the ways in which parents control their children. We hypothesize that both religious orthodoxy and weekly religious attendance are related to heightened levels of three elements of parental control: monitoring activities, normative regulations, and network closure. Results indicate that an orthodox religious identity for Catholic and Protestant parents and higher levels of religious attendance for parents as a whole are associated with increases in monitoring activities and normative regulations of American adolescents

    Results of the Cooperative Uniform Soybean Tests, 1948 Part I. North Central States

    Get PDF
    United States Department of Agriculture, Agricultural Research Administration; Bureau of Plant Industry, Soils, and Agricultural Engineering, Division of Forage Crops and Diseases Cooperating with State Agricultural Experiment Station

    SNP Genotyping Defines Complex Gene-Flow Boundaries Among African Malaria Vector Mosquitoes

    Get PDF
    Mosquitoes in the Anopheles gambiae complex show rapid ecological and behavioral diversification, traits that promote malaria transmission and complicate vector control efforts. A high-density, genome-wide mosquito SNP-genotyping array allowed mapping of genomic differentiation between populations and species that exhibit varying levels of reproductive isolation. Regions near centromeres or within polymorphic inversions exhibited the greatest genetic divergence, but divergence was also observed elsewhere in the genomes. Signals of natural selection within populations were overrepresented among genomic regions that are differentiated between populations, implying that differentiation is often driven by population-specific selective events. Complex genomic differentiation among speciating vector mosquito populations implies that tools for genome-wide monitoring of population structure will prove useful for the advancement of malaria eradication

    Andromeda XXV -- a dwarf galaxy with a low central dark matter density

    Get PDF
    Andromeda (And) XXV has previously been reported as a dwarf spheroidal galaxy (dSph) with little-to-no dark matter. However, the uncertainties on this result were significant. In this study, we double the number of member stars and re-derive the kinematics and mass of And XXV. We find that And XXV has a systemic velocity of νr=107.7±1.0 kms1\nu_\mathrm{r}=-107.7\pm1.0 \mathrm{~km s}^{-1} and a velocity dispersion of σν=4.5±1.0 kms1\sigma_\nu=4.5\pm1.0\mathrm{~km s}^{-1}. With this better constrained velocity dispersion, we derive a mass contained within the half-light radius of M(r<rh)=6.92.8+3.2×106 MM(r< r_\mathrm{h})=6.9^{+3.2}_{-2.8}\times10^6\mathrm{~M}_\odot. This mass corresponds to a mass-to-light ratio of [M/L]rh=3715+17 M/L\mathrm{[M/L]}_\mathrm{r_\mathrm{h}}=37^{+17}_{-15}\mathrm{~M}_\odot/\mathrm{L}_\odot, demonstrating, for the first time, that And XXV has an unambiguous dark matter component. We also measure the metallicity of And XXV to be [Fe/H]=1.9±0.1\mathrm{[Fe/H]}=-1.9\pm0.1 \mathrm{~}dex, which is in agreement with previous results. Finally, we extend the analysis of And XXV to include mass modelling using GravSphere. We find that And XXV has a low central dark matter density, ρDM(150pc)=2.71.6+1.8×107 Mkpc3\rho_\mathrm{DM}(150\mathrm{pc})= 2.7^{+1.8}_{-1.6}\times10^7\mathrm{~M}_\odot\mathrm{kpc}^{-3}, making And XXV a clear outlier when compared to other Local Group (LG) dSphs of the similar stellar mass. In a companion paper, we will explore whether some combination of dark matter cusp-core transformations and/or tides can explain And XXV's low density.Comment: 13 pages, 8 figures (7 main, 1 appendix). Submitted to MNRA
    corecore