145 research outputs found
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Comparing and Integrating Fish Surveys in the San Francisco Estuary: Why Diverse Long-Term Monitoring Programs are Important
Many fishes in the San Francisco Estuary have suffered declines in recent decades, as shown by numerous long-term monitoring programs. A long-term monitoring program, such as the Interagency Ecological Program, comprises a suite of surveys, each conducted by a state or federal agency or academic institution. These types of programs have produced rich data sets that are useful for tracking species trends over time. Problems arise from drawing conclusions based on one or few surveys because each survey samples a different subset of species or reflects different spatial or temporal trends in abundance. The challenges in using data sets from these surveys for comparative purposes stem from methodological differences, magnitude of data, incompatible data formats, and end-user preference for familiar surveys. To improve the utility of these data sets and encourage multi-survey analyses, we quantitatively rate these surveys based on their ability to represent species trends, present a methodology for integrating long-term data sets, and provide examples that highlight the importance of expanded analyses. We identify areas and species that are under-sampled, and compare fish salvage data from large water export facilities with survey data. Our analysis indicates that while surveys are redundant for some species, no two surveys are completely duplicative. Differing trends become evident when considering individual and aggregate survey data, because they imply spatial, seasonal, or gear-dependent catch. Our quantitative ratings and integrated data set allow for improved and better-informed comparisons of species trends across surveys, while highlighting the importance of the current array of sampling methodologies
Measurement of Exclusive B Decays to Final States Containing a Charmed Baryon
Using data collected by the CLEO detector in the Upsilon(4S) region, we
report new measurements of the exclusive decays of B mesons into final states
of the type Lambda_c^+ p-bar n(pi), where n=0,1,2,3. We find signals in modes
with one, two and three pions and an upper limit for the two body decay
Lambda_c^+ pbar. We also make the first measurements of exclusive decays of B
mesons to Sigma_c p-bar n(pi), where n=0,1,2. We find signals in modes with one
and two pions and an upper limit for the two body decay Sigma_c p-bar.
Measurements of these modes shed light on the mechanisms involved in B decays
to baryons.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Measurement of the Masses and Widths of the Sigma_c^++ and Sigma_c^0 Charmed Baryons
Using data recorded by the CLEO II and CLEO II.V detector configurations at
CESR, we report new measurements of the masses of the Sigma_c^{++} and
Sigma_c^0 charmed baryons, and the first measurements of their intrinsic
widths. We find M(Sigma_c^{++}) - M(Lambda_c^+) = 167.4 +- 0.1 +- 0.2 MeV,
Gamma(Sigma_c^{++}) = 2.3 +- 0.2 +- 0.3 MeV, and M(Sigma_c^0) - M(Lambda_c^+) =
167.2 +- 0.1 +- 0.2 MeV, Gamma(Sigma_c^0) = 2.5 +- 0.2 +- 0.3 MeV, where the
uncertainties are statistical and systematic, respectively.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PRD, Rapid
Communications. Reference [13] correcte
Evidence for the Decay
We present a search for the ``wrong-sign'' decay D0 -> K+ pi- pi+ pi- using 9
fb-1 of e+e- collisions on and just below the Upsilon(4S) resonance. This decay
can occur either through a doubly Cabibbo-suppressed process or through mixing
to a D0bar followed by a Cabibbo-favored process. Our result for the
time-integrated wrong-sign rate relative to the decay D0 -> K- pi+ pi- pi+ is
(0.0041 +0.0012-0.0011(stat.) +-0.0004(syst.))x(1.07 +-0.10)(phase space),
which has a statistical significance of 3.9 standard deviations.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Observation of Exclusive barB --> D(*) K*- Decays
We report the first observation of the exclusive decays \bar B\to
D^{(*)}K^{*-}, using 9.66 x 10^{6} B\bar{B} pairs collected at the \Upsilon(4S)
with the CLEO detector. We measure the following branching fractions: {\cal
B}(B^- -> D^0 K^{*-})=(6.1 +- 1.6 +-1.7)x10^{-4}, {\cal B}(\bar{B^0} ->
D^+K^{*-})=(3.7 +- 1.5 +- 1.0) x 10^{-4}, {\cal B}(\bar{B^0} ->
D^{*+}K^{*-})=(3.8 +- 1.3 +- 0.8) x 10^{-4} and {\cal B}(B^- --> D^{*0}
K^{*-})=(7.7 +- 2.2 +- 2.6) x 10^{-4}. The \bar B ->D^*K^{*-} branching ratios
are the averages of those corresponding to the 00 and 11 helicity states. The
errors shown are statistical and systematic, respectively.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, Published in
Phys.Rev.Lett.88:101803,200
Search for the Decay
We report on a search for the radiative decay U(1S) -> gamma + eta' in 61.3
pb^-1 of data taken with the CLEO II detector at the Cornell Electron Storage
Ring. Three decay chains were investigated, all involving eta' -> pi+ pi- +
eta, followed by eta -> gamma + gamma, eta -> pi0 + pi0 + pi0, or eta -> pi+ +
pi- + pi0. We find no candidate events in any of the three cases and set a
combined upper limit of 1.6 x 10^-5 at 90% C.L., significantly smaller than the
previous limit. We compare our result to other radiative U(1S) decays, to
radiative J/psi decays, and to theoretical predictions.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Cultural distance, mindfulness and passive xenophobia: Using Integrated Threat Theory to explore home higher education students' perspectives on 'internationalisation at home'
This paper addresses the question of interaction between home and international students using qualitative data from 100 home students at two 'teaching intensive' universities in the southwest of England. Stephan and Stephan's Integrated Threat Theory is used to analyse the data, finding evidence for all four types of threat that they predict when outgroups interact. It is found that home students perceive threats to their academic success and group identity from the presence of international students on the campus and in the classroom. These are linked to anxieties around 'mindful' forms of interaction and a taboo around the discussion of difference, leading to a 'passive xenophobia' for the majority. The paper concludes that Integrated Threat Theory is a useful tool in critiquing the 'internationalisation at home' agenda, making suggestions for policies and practices that may alleviate perceived threats, thereby improving the quality and outcomes of intercultural interaction. © 2010 British Educational Research Association
Measurement of Gamma(ee)(J/psi), Gamma(tot)(J/psi), and Gamma(ee)[psi(2S)]/Gamma(ee)(J/psi)
Using data acquired with the CLEO detector at the CESR e(+)e(-) collider at root s=3.773 GeV, we measure the cross section for the radiative return process e(+)e(-)-\u3egamma J/psi, J/psi -\u3emu(+)mu(-), resulting in B(J/psi -\u3emu(+)mu(-))x Gamma(ee)(J/psi)=0.3384 +/- 0.0058 +/- 0.0071 keV, Gamma(ee)(J/psi)=5.68 +/- 0.11 +/- 0.13 keV, and Gamma(tot)(J/psi)=95.5 +/- 2.4 +/- 2.4 keV, in which the errors are statistical and systematic, respectively. We also determine the ratio Gamma(ee)[psi(2S)]/Gamma(ee)(J/psi)=0.45 +/- 0.01 +/- 0.02
Measurement of the D+ --> K*0bar l+ nu_l Branching Fraction
Using 13.53/fb of CLEO data, we have measured the ratios of the branching
fractions R+(e) = BF(D+ --> K*0bar e+ nu_e) / BF(D+ --> K- pi+ pi+), R+(mu) =
BF(D+ --> K*0bar mu+ nu_mu) / BF(D+ --> K- pi+ pi+) and the combined branching
fraction ratio R+(l) = BF(D+ --> K*0bar l+ nu_l) / BF(D+ --> K- pi+ pi+). We
find R+(e) = 0.74 +- 0.04 +- 0.05, R+(mu) = 0.72 +- 0.10 +- 0.06 and R+(l) =
0.74 +- 0.04 +- 0.05, where the first and second errors are statistical and
systematic respectively. The known branching fraction BF(D+ --> K- pi+ pi+)
leads to: BF(D+ --> K*0bar e+ nu_e) = (6.7 +- 0.4 +- 0.5 +- 0.4)%, BF(D+ -->
K*0bar mu+ \nu_mu) = (6.5 +- 0.9 +- 0.5 +- 0.4)% and BF(D+ --> K*0bar l+ nu_l)
= (6.7 +- 0.4 +- 0.5 +- 0.4)%, where the third error is due to the uncertainty
in BF(D+ --> K- pi+ pi+).Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, Submitted to PR
Photon transitions in psi(2S) decays to chi(cJ)(1P) and eta(c)(1S)
We have studied the inclusive photon spectrum in psi(2S) decays using the CLEO III detector. We present the most precise measurements of electric dipole (E1) photon transition rates for psi(2S)--\u3egammachi(cJ)(1P) (J=0,1,2). We also confirm the hindered magnetic dipole (M1) transition, psi(2S)--\u3egammaeta(c)(1S). However, the direct M1 transition psi(2S)--\u3egammaeta(c)(2S) observed by the Crystal Ball as a narrow peak at a photon energy of 91 MeV is not found in our data
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