2,302 research outputs found
Recommended from our members
Investigations into insect vectoring of Fusarium poae in bluegrass seed crops
Recommended from our members
Grass mealy bug as vector of Fusariium poae (silver top) in Kentucky blue grass 2003-2004
Recommended from our members
Combining quantitative and qualitative survey work. Methodological framework, practical issues, and case studies
This document is an output of the DFID funded research project R7033 "Methodological Framework for Integrating Qualitative and Quantitative Approaches for Socio-Economic Survey Work". The project's main objective was to improve survey methodologies used in the natural resources sector, leading in turn to improved quality of information required for decision-making at the various stages of natural resources programmes and projects. The project, which was jointly implemented by the Natural Resources Institute and the Statistical Services Centre, attempted to bridge the gap between informal I qualitative methods on the one hand and formal I quantitative ones on the other. The document is presented in the form of a manual, allowing the user to read each of its parts and sections independently of each other. Nevertheless, cross references indicate links to other parts of the document where appropriate. Part I provides a methodological framework, which will also be available as a Best-Practice Guideline published by the Natural Resources Systems Programme of DFID. Part 11, which contains six theme papers, looks into a number of practical issues encountered when combining quantitative and qualitative survey techniques. And finally, in Part III case studies are used to demonstrate how the two approaches can be integrated in survey work and experiments related to the natural resources sector. The framework document, theme papers and case studies have been produced between 1998 and 2000
On the Lack of Correlation Between [OIII]/[OII] and Lyman-Continuum Escape Fraction
We present the first results of our pilot study of 8 photometrically selected
Lyman continuum (LyC) emitting galaxy candidates from the COSMOS field and
focus on their optical emission line ratios. Observations were performed in the
H and K bands using the Multi-Object Spectrometer for Infra-Red Exploration
(MOSFIRE) instrument at the Keck Observatory, targeting the [OII], H,
and [OIII] emission lines. We find that photometrically selected LyC emitting
galaxy candidates have high ionization parameters, based on their high
[OIII]/[OII] ratios (O32), with an average ratio for our sample of 2.50.2.
Preliminary results of our companion Low Resolution Imaging Spectrometer (LRIS)
observations, targeting LyC and Ly, show that those galaxies with the
largest O32 are typically found to also be Ly emitters. High O32
galaxies are also found to have tentative non-zero LyC escape fractions
() based on band photometric detections. These results are
consistent with samples of highly ionized galaxies, including confirmed LyC
emitting galaxies from the literature. We also perform a detailed comparison
between the observed emission line ratios and simulated line ratios from
density bounded H regions modeled using the photoionization
code MAPPINGS V. Estimates of for our sample fall in the range
from 0.0-0.23 and suggest possible tension with published correlations between
O32 and , adding weight to dichotomy of arguments in the
literature. We highlight the possible effects of clumpy geometry and mergers
that may account for such tension.Comment: 21 pages, 11 figures, 3 tables, accepted for publication in MNRA
Evidence for CP Violation in B0 -> D+D- Decays
We report measurements of the branching fraction and CP violation parameters
in B0 -> D+D- decays. The results are based on a data sample that contains 535
x 10^6 BBbar pairs collected at the Upsilon(4S) resonance, with the Belle
detector at the KEKB asymmetric-energy e+e- collider. We obtain [1.97 +- 0.20
(stat) +- 0.20 (syst)] x 10^(-4) for the branching fraction of B0 -> D+D-. The
measured values of the CP violation parameters are: S = -1.13 +- 0.37 +- 0.09,
A = 0.91 +- 0.23 +- 0.06, where the first error is statistical and the second
is systematic. We find evidence of CP violation in B0 -> D+D- at the 4.1 sigma
confidence level. While the value of S is consistent with expectations from
other measurements, the value of the parameter A favors large direct CP
violation at the 3.2 sigma confidence level, in contradiction to Standard Model
expectations.Comment: 12 pages, 3 figures, submitted to PR
Averages of -hadron, -hadron, and -lepton properties as of summer 2014
This article reports world averages of measurements of -hadron,
-hadron, and -lepton properties obtained by the Heavy Flavor Averaging
Group (HFAG) using results available through summer 2014. For the averaging,
common input parameters used in the various analyses are adjusted (rescaled) to
common values, and known correlations are taken into account. The averages
include branching fractions, lifetimes, neutral meson mixing parameters,
violation parameters, parameters of semileptonic decays and CKM matrix
elements.Comment: 436 pages, many figures and tables. Online updates available at
http://www.slac.stanford.edu/xorg/hfag
Observation of Bs->Ds(*)+Ds(*)- using e+e- collisions and a determination of the Bs-Bsbar width difference \Delta\Gamma_s
We have made the first observation of Bs->Ds(*)+Ds(*)- decays using 23.6 fb-1
of data recorded by the Belle experiment running on the Upsilon(5S) resonance.
The branching fractions are measured to be B(B^0_s\ra D^+_s D^-_s) =
(1.0\,^{+0.4}_{-0.3}\,^{+0.3}_{-0.2})%, B(B^0_s\ra D^{*\pm}_s D^{\mp}_s) =
(2.8\,^{+0.8}_{-0.7}\,\pm 0.7)%, and B(B^0_s\ra D^{*+}_s D^{*-}_s) =
(3.1\,^{+1.2}_{-1.0}\,\pm 0.8)%; the sum is B(B^0_s\ra D^{(*)+}_s D^{(*)-}_s) =
(6.9\,^{+1.5}_{-1.3}\,\pm 1.9)%. Assuming Bs->Ds(*)+Ds(*)- saturates decays to
CP-even final states, the branching fraction determines the ratio
\Delta\Gamma_s/cos(\phi), where \Delta\Gamma_s is the difference in widths
between the two Bs-Bsbar mass eigenstates, and \phi is a CP-violating weak
phase. Taking CP violation to be negligibly small, we obtain
\Delta\Gamma_s/\Gamma_s =
0.147^{+0.036}_{-0.030}(stat.)^{+0.044}_{-0.042}(syst.), where \Gamma_s is the
mean decay width.Comment: 13 pages, 2 figures, 2 tables. v2: text added for clarification,
version published in Phys. Rev. Letter
- …