331 research outputs found

    The Coral reef fishes of Broward County Florida, species and abundance: a work in progress

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    The inshore environment of Broward County, FL consists of three coral reef/hard bottom reef tracts, separated by sand substrate, running parallel to the coast in sequentially deeper water. At quarter nautical mile intervals, for a five mile coastline section, fishes were censused at western, eastern and crest sites of each of the three reef tracts. On SCUBA and using the Bohnsack/Bannerot point-count method, we recorded: fish abundance, species richness, size, and general habitat of an imaginary cylinder 15 m in diameter. The position of each site was recorded by DGPS after census. One hundred and eighty-one sites were censused during a 10 month period (August 1998 to May 1999). A total of 16,746 fish belonging to 139 species of 39 families were recorded. There were significant differences (p \u3c 0.05, ANOVA) in the species richness and the total abundance of fishes among the three reef tracts. There were significantly fewer total fish (p \u3c 0.001) and fewer fish species (p \u3c 0.001) on the inshore reef tract as compared to either the middle or offshore reef tracts. The middle and offshore reefs tracts did not differ (p \u3e 0.05, SNK). Differences were also found based on the location (edges or crest) on the reef. With all data from the three reef tracts combined, the eastern edge showed significantly fewer total fish (p \u3c 0.001) than either the crest of the reef or the western edge, which did not differ significantly (p\u3e 0.05). Species richness also varied with the western edges of the tracts having significantly more species (p \u3c 0.01) than the crests or the eastern edges, again there was no significant difference between these two (p \u3e 0.05). Statistical analysis of a subjective complexity rating taken at each site mirrored the results of fish abundance and species richness. This supports the hypothesis that topographical complexity is, at least in part, a determinant in the differences in fish assemblages among the three reef tracts

    Two-hole bound states in modified t-J model

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    We consider modified t−Jt-J model with minimum of single-hole dispersion at the points (0,±π)(0,\pm \pi), (±π,0)(\pm \pi,0). It is shown that two holes on antiferromagnetic background produce a bound state which properties strongly differs from the states known in the unmodified t−Jt-J model. The bound state is d-wave, it has four nodes on the face of the magnetic Brillouin zone. However, in the coordinate representation it looks like as usual s-wave.Comment: LaTeX 9 page

    Nip1p associates with 40 S ribosomes and the Prt1p subunit of eukaryotic initiation factor 3 and is required for efficient translation initiation

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    Nip1p is an essential Saccharomyces cerevisiae protein that was identified in a screen for temperature conditional (ts) mutants exhibiting defects in nuclear transport. New results indicate that Nip1p has a primary role in translation initiation. Polysome profiles indicate that cells depleted of Nip1p and nip1-1 cells are defective in translation initiation, a conclusion that is supported by a reduced rate of protein synthesis in Nip1p- depleted cells. Nip1p cosediments with free 40 S ribosomal subunits and polysomal preinitiation complexes, but not with free or elongating 80 S ribosomes or 60 S subunits. Nip1p can be isolated in an about 670-kDa complex containing polyhistidine-tagged Prt1p, a subunit of translation initiation factor 3, by binding to Ni2+NTA-agarose beads in a manner completely dependent on the tagged form of Prt1p. The nip1-1 ts growth defect was suppressed by the deletion of the ribosomal protein, RPL46. Also, nip1-1 mutant cells are hypersensitive to paromomycin. These results suggest that Nip1p is a subunit of eukaryotic initiation factor 3 required for efficient translation initiation

    Towards a Criminology of the Domestic

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    Criminology has paid insufficient attention to the ‘domestic’ arena, as a locale that is being reconfigured through technological and social developments in ways that require us to reconsider offending and victimisation. This article addresses this lacuna. We take up Campbell's (2016) challenge that criminology needs to develop more sophisticated models of place and space, particularly in relation to changing patterns of consumption and leisure activity and the opportunities to offend in relation to these from within the domestic arena

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

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    We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

    Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

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    This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio
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