1,190 research outputs found
Individual and Population Level Resource Selection Patterns of Mountain Lions Preying on Mule Deer along an Urban-Wildland Gradient
Understanding population and individual-level behavioral responses of large carnivores to human disturbance is important for conserving top predators in fragmented landscapes. However, previous research has not investigated resource selection at predation sites of mountain lions in highly urbanized areas. We quantified selection of natural and anthropogenic landscape features by mountain lions at sites where they consumed their primary prey, mule deer (Odocoileus hemionus), in and adjacent to urban, suburban, and rural areas in greater Los Angeles. We documented intersexual and individual-level variation in the environmental conditions present at mule deer feeding sites relative to their availability across home ranges. Males selected riparian woodlands and areas closer to water more than females, whereas females selected developed areas marginally more than males. Females fed on mule deer closer to developed areas and farther from riparian woodlands than expected based on the availability of these features across their home ranges.We suggest that mortality risk for females and their offspring associated with encounters with males may have influenced the different resource selection patterns between sexes. Males appeared to select mule deer feeding sites mainly in response to natural landscape features, while females may have made kills closer to developed areas in part because these are alternative sites where deer are abundant. Individual mountain lions of both sexes selected developed areas more strongly within home ranges where development occurred less frequently. Thus, areas near development may represent a trade-off for mountain lions such that they may benefit from foraging near development because of abundant prey, but as the landscape becomes highly urbanized these benefits may be outweighed by human disturbance
Use of Anticoagulant Rodenticides in Single-Family Neighborhoods Along an Urban-Wildland Interface in California
Urbanization poses many threats for many wildlife species. In addition to habitat loss and fragmentation, non-target wildlife species are vulnerable to poisoning by rodenticides, especially acutely toxic second generation anticoagulant rodenticides (SGARs). Although such poisonings are well documented for birds and mammals worldwide, the pathways by which these widely available compounds reach non-target wildlife have not been adequately studied, particularly in urban landscapes. Long-term studies of wild carnivores in and around Santa Monica Mountains National Recreation Area, a national park north of Los Angeles, have documented \u3e85% exposure to anticoagulant rodenticides among bobcats, coyotes, and mountain lions. To investigate potential mechanisms of transfer of chemicals from residential users of rodenticides to non-target wildlife in the Santa Monica Mountains in Los Angeles County, California, we distributed surveys to residents in two study areas on the north (San Fernando Valley) and south (Bel Air-Hollywood Hills) slopes of these mountains. We assessed knowledge of residents about the environmental effects of rodenticides, and for information about individual application of chemicals. We asked for the same information from pest control operators (PCOs) in both study areas. Forty residents completed the survey in the San Fernando Valley area, and 20 residents completed the survey in Bel Air-Hollywood Hills. Despite the small number of total responses, we documented a number of important findings. Homeowners (as opposed to gardeners or PCOs) were the primary applicators of rodenticides, predominantly SGARs, and awareness of the hazards of secondary poisoning to wildlife was not consistent. Some residents reported improperly applying rodenticides (e.g., exceeding prescribed distances from structures), and in one instance a respondent reported observing dead animals outside after placing poison inside a structure. Improper application of SGARs that ignores label guidelines occurs in neighborhoods along the urban–wildland interface, thereby providing a transmission pathway for chemical rodenticides to reach native wildlife. Moreover, the responses suggest that even on-label use (e.g. placing poisons inside) can create risk for non-target wildlife
Studies of the decays D^0 \rightarrow K_S^0K^-\pi^+ and D^0 \rightarrow K_S^0K^+\pi^-
The first measurements of the coherence factor R_{K_S^0K\pi} and the average
strong--phase difference \delta^{K_S^0K\pi} in D^0 \to K_S^0 K^\mp\pi^\pm
decays are reported. These parameters can be used to improve the determination
of the unitary triangle angle \gamma\ in B^- \rightarrow
decays, where is either a D^0 or a D^0-bar meson decaying to
the same final state, and also in studies of charm mixing. The measurements of
the coherence factor and strong-phase difference are made using
quantum-correlated, fully-reconstructed D^0D^0-bar pairs produced in e^+e^-
collisions at the \psi(3770) resonance. The measured values are R_{K_S^0K\pi} =
0.70 \pm 0.08 and \delta^{K_S^0K\pi} = (0.1 \pm 15.7) for an
unrestricted kinematic region and R_{K*K} = 0.94 \pm 0.12 and \delta^{K*K} =
(-16.6 \pm 18.4) for a region where the combined K_S^0 \pi^\pm
invariant mass is within 100 MeV/c^2 of the K^{*}(892)^\pm mass. These results
indicate a significant level of coherence in the decay. In addition, isobar
models are presented for the two decays, which show the dominance of the
K^*(892)^\pm resonance. The branching ratio {B}(D^0 \rightarrow
K_S^0K^+\pi^-)/{B}(D^0 \rightarrow K_S^0K^-\pi^+) is determined to be 0.592 \pm
0.044 (stat.) \pm 0.018 (syst.), which is more precise than previous
measurements.Comment: 38 pages. Version 3 updated to include the erratum information.
Errors corrected in Eqs (25), (26), 28). Fit results updated accordingly, and
external inputs updated to latest best known values. Typo corrected in Eq(3)-
no other consequence
Updated Measurement of the Strong Phase in D0 --> K+pi- Decay Using Quantum Correlations in e+e- --> D0 D0bar at CLEO
We analyze a sample of 3 million quantum-correlated D0 D0bar pairs from 818
pb^-1 of e+e- collision data collected with the CLEO-c detector at E_cm = 3.77
GeV, to give an updated measurement of \cos\delta and a first determination of
\sin\delta, where \delta is the relative strong phase between doubly
Cabibbo-suppressed D0 --> K+pi- and Cabibbo-favored D0bar --> K+pi- decay
amplitudes. With no inputs from other experiments, we find \cos\delta = 0.81
+0.22+0.07 -0.18-0.05, \sin\delta = -0.01 +- 0.41 +- 0.04, and |\delta| = 10
+28+13 -53-0 degrees. By including external measurements of mixing parameters,
we find alternative values of \cos\delta = 1.15 +0.19+0.00 -0.17-0.08,
\sin\delta = 0.56 +0.32+0.21 -0.31-0.20, and \delta = (18 +11-17) degrees. Our
results can be used to improve the world average uncertainty on the mixing
parameter y by approximately 10%.Comment: Minor revisions, version accepted by PR
Three Pathogens in Sympatric Populations of Pumas, Bobcats, and Domestic Cats: Implications for Infectious Disease Transmission
Anthropogenic landscape change can lead to increased opportunities for pathogen transmission between domestic and non-domestic animals. Pumas, bobcats, and domestic cats are sympatric in many areas of North America and share many of the same pathogens, some of which are zoonotic. We analyzed bobcat, puma, and feral domestic cat samples collected from targeted geographic areas. We examined exposure to three pathogens that are taxonomically diverse (bacterial, protozoal, viral), that incorporate multiple transmission strategies (vector-borne, environmental exposure/ ingestion, and direct contact), and that vary in species-specificity. Bartonella spp., Feline Immunodeficiency Virus (FIV), and Toxoplasma gondii IgG were detected in all three species with mean respective prevalence as follows: puma 16%, 41% and 75%; bobcat 31%, 22% and 43%; domestic cat 45%, 10% and 1%. Bartonella spp. were highly prevalent among domestic cats in Southern California compared to other cohort groups. Feline Immunodeficiency Virus exposure was primarily associated with species and age, and was not influenced by geographic location. Pumas were more likely to be infected with FIV than bobcats, with domestic cats having the lowest infection rate. Toxoplasma gondii seroprevalence was high in both pumas and bobcats across all sites; in contrast, few domestic cats were seropositive, despite the fact that feral, free ranging domestic cats were targeted in this study. Interestingly, a directly transmitted species-specific disease (FIV) was not associated with geographic location, while exposure to indirectly transmitted diseases – vectorborne for Bartonella spp. and ingestion of oocysts via infected prey or environmental exposure for T. gondii – varied significantly by site. Pathogens transmitted by direct contact may be more dependent upon individual behaviors and intra-specific encounters. Future studies will integrate host density, as well as landscape features, to better understand the mechanisms driving disease exposure and to predict zones of cross-species pathogen transmission among wild and domestic felids
Observation of the Dalitz Decay
Using 586 of collision data acquired at
GeV with the CLEO-c detector at the Cornell Electron Storage
Ring, we report the first observation of
with a significance of . The ratio of branching fractions
\calB(D_{s}^{*+} \to D_{s}^{+} e^{+} e^{-}) / \calB(D_{s}^{*+} \to D_{s}^{+}
\gamma) is measured to be , which is consistent with theoretical expectations
Search for rare and forbidden decays of charm and charmed-strange mesons to final states h^+- e^-+ e^+
We have searched for flavor-changing neutral current decays and
lepton-number-violating decays of D^+ and D^+_s mesons to final states of the
form h^+- e^-+ e^+, where h is either \pi or K. We use the complete samples of
CLEO-c open-charm data, corresponding to integrated luminosities of 818 pb^-1
at the center-of-mass energy E_CM = 3.774 GeV containing 2.4 x 10^6 D^+D^-
pairs and 602 pb^-1 at E_CM = 4.170 GeV containing 0.6 x 10^6 D^*+-_s D^-+_s
pairs. No signal is observed in any channel, and we obtain 90% confidence level
upper limits on branching fractions B(D^+ --> \pi^+ e^+ e^-) < 5.9 x 10^-6,
B(D^+ --> \pi^- e^+ e^+) K^+ e^+ e^-) < 3.0 x 10^-6,
B(D^+ --> K^- e^+ e^+) \pi^+ e^+ e^-) < 2.2 x 10^-5,
B(D^+_s --> \pi^- e^+ e^+) K^+ e^+ e^-) < 5.2 x
10^-5, and B(D^+_s --> K^- e^+ e^+) < 1.7 x 10^-5.Comment: 9 pages, available through http://www.lns.cornell.edu/public/CLNS
Branching fractions for Y(3S) -> pi^0 h_b and psi(2S) -> pi^0 h_c
Using e^+e^- collision data corresponding to 5.88M Y(3S) [25.9M psi(2S)]
decays and acquired by the CLEO III [CLEO-c] detectors operating at CESR, we
study the single-pion transitions from Y(3S) [psi(2S)] to the respective
spin-singlet states h_{b[c]}. Utilizing only the momentum of suitably selected
transition-pi^0 candidates, we obtain the upper limit B(Y(3S) -> pi^0 h_b) <
1.2\times 10^{-3} at 90% confidence level, and measure B(psi(2S) -> pi^0 h_c) =
(9.0+-1.5+-1.3)\times 10^{-4}. Signal sensitivities are enhanced by excluding
very asymmetric pi^0 -> gamma gamma candidates.Comment: 12 pages 4 figures, version published in Physical Review
Measurement of the eta-Meson Mass using psi(2S) --> eta J/psi
We measure the mass of the eta meson using psi(2S) --> eta J/psi events
acquired with the CLEO-c detector operating at the CESR e+e- collider. Using
the four decay modes eta --> gamma gamma, 3pi0, pi+pi-pi0, and pi+pi-gamma, we
find M(eta)=547.785 +- 0.017 +- 0.057 MeV, in which the first uncertainty is
statistical and the second systematic. This result has an uncertainty
comparable to the two most precise previous measurements and is consistent with
that of NA48, but is inconsistent at the level of 6.5sigma with the much
smaller mass obtained by GEM.Comment: 10 pages postscript,also available through
http://www.lns.cornell.edu/public/CLNS/2007/, Submitted to PR
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