222 research outputs found

    \u3ci\u3eOligacanthorhynchus lamasi\u3c/i\u3e (Freitas and Costa, 1964) comb. n. from Domestic Cats of Brazil

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    Freitas and Costa (1964, Arq. Esc. Vet. Univ. Fed. Minas Gerais 16:231-234) described a new species, Echinopardalis lamasi, from two acanthocephalans (1 male, 1 female) of a cat, Felis domestica (=F. catus), captured in Belo Horizonte, Minas Gerais. These specimens have been lost (Freitas, 1975, personal communication). Until two of 127 domestic cats, F. catus, from Porto Alegre, Rio Grande do SuI, captured between October 1973 and July 1976, were found to harbor respectively two and nine acanthocephalans conspecific with those described by Freitas and Costa, no additional specimens of this species were available for study. These new specimens assist in clarifying the generic affinities of E. lamasi and permit additions to the species description

    \u3ci\u3eOligacanthorhynchus lamasi\u3c/i\u3e (Freitas and Costa, 1964) comb. n. from Domestic Cats of Brazil

    Get PDF
    Freitas and Costa (1964, Arq. Esc. Vet. Univ. Fed. Minas Gerais 16:231-234) described a new species, Echinopardalis lamasi, from two acanthocephalans (1 male, 1 female) of a cat, Felis domestica (=F. catus), captured in Belo Horizonte, Minas Gerais. These specimens have been lost (Freitas, 1975, personal communication). Until two of 127 domestic cats, F. catus, from Porto Alegre, Rio Grande do SuI, captured between October 1973 and July 1976, were found to harbor respectively two and nine acanthocephalans conspecific with those described by Freitas and Costa, no additional specimens of this species were available for study. These new specimens assist in clarifying the generic affinities of E. lamasi and permit additions to the species description

    Search for composite and exotic fermions at LEP 2

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    A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

    Search for charginos in e+e- interactions at sqrt(s) = 189 GeV

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    An update of the searches for charginos and gravitinos is presented, based on a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector in 1998, at a centre-of-mass energy of 189 GeV. No evidence for a signal was found. The lower mass limits are 4-5 GeV/c^2 higher than those obtained at a centre-of-mass energy of 183 GeV. The (\mu,M_2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 31.0 GeV/c^2 for tan(beta) \geq 1.Comment: 22 pages, 8 figure

    Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP

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    Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of the production of these particles is found. Hence, lower mass limits for both kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is found to be greater than 71.5 GeV/c^2. In the search for long-lived stau, masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10 to 150 \eVcc . Combining this search with the searches for stable heavy leptons and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc may be set for the stau mas

    Updated precision measurement of the average lifetime of B hadrons

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    The measurement of the average lifetime of B hadrons using inclusively reconstructed secondary vertices has been updated using both an improved processing of previous data and additional statistics from new data. This has reduced the statistical and systematic uncertainties and gives \tau_{\mathrm{B}} = 1.582 \pm 0.011\ \mathrm{(stat.)} \pm 0.027\ \mathrm{(syst.)}\ \mathrm{ps.} Combining this result with the previous result based on charged particle impact parameter distributions yields \tau_{\mathrm{B}} = 1.575 \pm 0.010\ \mathrm{(stat.)} \pm 0.026\ \mathrm{(syst.)}\ \mathrm{ps.

    Factors influencing terrestriality in primates of the Americas and Madagascar

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    Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (body mass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use

    Sensitivity of the Cherenkov Telescope Array to TeV photon emission from the Large Magellanic Cloud

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    A deep survey of the Large Magellanic Cloud at ~0.1-100 TeV photon energies with the Cherenkov Telescope Array is planned. We assess the detection prospects based on a model for the emission of the galaxy, comprising the four known TeV emitters, mock populations of sources, and interstellar emission on galactic scales. We also assess the detectability of 30 Doradus and SN 1987A, and the constraints that can be derived on the nature of dark matter. The survey will allow for fine spectral studies of N 157B, N 132D, LMC P3, and 30 Doradus C, and half a dozen other sources should be revealed, mainly pulsar-powered objects. The remnant from SN 1987A could be detected if it produces cosmic-ray nuclei with a flat power-law spectrum at high energies, or with a steeper index 2.3-2.4 pending a flux increase by a factor of >3-4 over ~2015-2035. Large-scale interstellar emission remains mostly out of reach of the survey if its >10 GeV spectrum has a soft photon index ~2.7, but degree-scale 0.1-10 TeV pion-decay emission could be detected if the cosmic-ray spectrum hardens above >100 GeV. The 30 Doradus star-forming region is detectable if acceleration efficiency is on the order of 1-10 per cent of the mechanical luminosity and diffusion is suppressed by two orders of magnitude within <100 pc. Finally, the survey could probe the canonical velocity-averaged cross-section for self-annihilation of weakly interacting massive particles for cuspy Navarro-Frenk-White profiles
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