11,156 research outputs found

    Late Miocene to early Pliocene stratigraphic record in northern Taranaki Basin: Condensed sedimentation ahead of Northern Graben extension and progradation of the modern continental margin

    Get PDF
    The middle Pliocene-Pleistocene progradation of the Giant Foresets Formation in Taranaki Basin built up the modern continental margin offshore from western North Island. The late Miocene to early Pliocene interval preceding this progradation was characterised in northern Taranaki Basin by the accumulation of hemipelagic mudstone (Manganui Formation), volcaniclastic sediments (Mohakatino Formation), and marl (Ariki Formation), all at bathyal depths. The Manganui Formation has generally featureless wireline log signatures and moderate to low amplitude seismic reflection characteristics. Mohakatino Formation is characterised by a sharp decrease in the GR log value at its base, a blocky GR log motif reflecting sandstone packets, and erratic resistivity logs. Seismic profiles show bold laterally continuous reflectors. The Ariki Formation has a distinctive barrel-shaped to blocky GR log motif. This signature is mirrored by the SP log and often by an increase in resistivity values through this interval. The Ariki Formation comprises (calcareous) marl made up of abundant planktic foraminifera, is 109 m thick in Ariki-1, and accumulated over parts of the Western Stable Platform and beneath the fill of the Northern Graben. It indicates condensed sedimentation reflecting the distance of the northern region from the contemporary continental margin to the south

    (13)C NMR investigation of the superconductor MgCNi_3 up to 800K

    Full text link
    We report (13)C NMR characterization of the new superconductor MgCNi_3 (He et al., Nature (411), 54 (2001)). We found that both the uniform spin susceptibility and the spin fluctuations show a strong enhancement with decreasing temperature, and saturate below ~50K and ~20K respectively. The nuclear spin-lattice relaxation rate 1/(13)T_1T exhibits typical behaviour for isotropic s-wave superconductivity with a coherence peak below Tc=7.0K that grows with decreasing magnetic field.Comment: Accepted for publication in Physical Review Letter

    Corticosteroids for the common cold

    Get PDF
    BACKGROUND: The common cold is a frequent illness, which, although benign and self limiting, results in many consultations to primary care and considerable loss of school or work days. Current symptomatic treatments have limited benefit. Corticosteroids are an effective treatment in other upper respiratory tract infections and their anti‐inflammatory effects may also be beneficial in the common cold. This updated review has included one additional study. OBJECTIVES: To compare corticosteroids versus usual care for the common cold on measures of symptom resolution and improvement in children and adults. SEARCH METHODS: We searched Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 4), which includes the Acute Respiratory Infections (ARI) Group's Specialised Register, the Database of Reviews of Effects (DARE) (2015, Issue 2), NHS Health Economics Database (2015, Issue 2), MEDLINE (1948 to May week 3, 2015) and EMBASE (January 2010 to May 2015). SELECTION CRITERIA: Randomised, double‐blind, controlled trials comparing corticosteroids to placebo or to standard clinical management. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed trial quality. We were unable to perform meta‐analysis and instead present a narrative description of the available evidence. MAIN RESULTS: We included three trials (353 participants). Two trials compared intranasal corticosteroids to placebo and one trial compared intranasal corticosteroids to usual care; no trials studied oral corticosteroids. In the two placebo‐controlled trials, no benefit of intranasal corticosteroids was demonstrated for duration or severity of symptoms. The risk of bias overall was low or unclear in these two trials. In a trial of 54 participants, the mean number of symptomatic days was 10.3 in the placebo group, compared to 10.7 in those using intranasal corticosteroids (P value = 0.72). A second trial of 199 participants reported no significant differences in the duration of symptoms. The single‐blind trial in children aged two to 14 years, who were also receiving oral antibiotics, had inadequate reporting of outcome measures regarding symptom resolution. The overall risk of bias was high for this trial. Mean symptom severity scores were significantly lower in the group receiving intranasal steroids in addition to oral amoxicillin. One placebo‐controlled trial reported the presence of rhinovirus in nasal aspirates and found no differences. Only one of the three trials reported on adverse events; no differences were found. Two trials reported secondary bacterial infections (one case of sinusitis, one case of acute otitis media; both in the corticosteroid groups). A lack of comparable outcome measures meant that we were unable to combine the data. AUTHORS' CONCLUSIONS: Current evidence does not support the use of intranasal corticosteroids for symptomatic relief from the common cold. However, there were only three trials, one of which was very poor quality, and there was limited statistical power overall. Further large, randomised, double‐blind, placebo‐controlled trials in adults and children are required to answer this question

    Hamiltonians for Reduced Gravity

    Get PDF
    A generalised canonical formulation of gravity is devised for foliations of spacetime with codimension n1n\ge1. The new formalism retains n-dimensional covariance and is especially suited to 2+2 decompositions of spacetime. It is also possible to use the generalised formalism to obtain boundary contributions to the 3+1 Hamiltonian.Comment: 18 pages, revtex, 3 postscript figures include

    The Magnetization of Cu_2(C_5H_{12}N_2)_2Cl_4 : A Heisenberg Spin Ladder System

    Full text link
    We study the magnetization of a Heisenberg spin ladder using exact diagonalization techniques, finding three distinct magnetic phases. We consider the results in relation to the experimental behaviour of the new copper compound Cu_2(C_5H_{12}N_2)_2Cl_4 and deduce that the compound is well described by such a model with a ratio of `chain' to `rung' bond strengths (J/J^\prime) of the order of 0.2, consistent with results from the magnetic susceptibility. The effects of temperature, spin impurities and additional diagonal bonds are presented and we give evidence that these diagonal bonds are indeed of a ferromagnetic nature.Comment: Latex file (4 pages), related figures (encapsulated postscript) appende

    Quasi-spherical approximation for rotating black holes

    Get PDF
    We numerically implement a quasi-spherical approximation scheme for computing gravitational waveforms for coalescing black holes, testing it against angular momentum by applying it to Kerr black holes. As error measures, we take the conformal strain and specific energy due to spurious gravitational radiation. The strain is found to be monotonic rather than wavelike. The specific energy is found to be at least an order of magnitude smaller than the 1% level expected from typical black-hole collisions, for angular momentum up to at least 70% of the maximum, for an initial surface as close as r=3mr=3m.Comment: revised version, 8 pages, RevTeX, 8 figures, epsf.sty, psfrag.sty, graphicx.st

    Construction and enlargement of traversable wormholes from Schwarzschild black holes

    Full text link
    Analytic solutions are presented which describe the construction of a traversable wormhole from a Schwarzschild black hole, and the enlargement of such a wormhole, in Einstein gravity. The matter model is pure radiation which may have negative energy density (phantom or ghost radiation) and the idealization of impulsive radiation (infinitesimally thin null shells) is employed.Comment: 22 pages, 7 figure

    Screening and diagnostic assessment of neurodevelopmental disorders in a male prison

    Get PDF
    Purpose The purpose of this paper is to identify neurodevelopmental disorders and difficulties (NDD) in a male prison. The study used standardised tools to carry out screening and diagnostic assessment of the attention deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD) and intellectual disability (ID). Design/methodology/approach The ADHD self-report scale, 20-item autism quotient and the Learning Disability Screening Questionnaire were used to screen 240 male prisoners. Prisoners who screened positive on one or more of these scales or self-reported a diagnosis of ADHD, ASD or ID were further assessed using the diagnostic interview for ADHD in adults, adapted Autism Diagnostic Observation Schedule and the Quick Test. Findings Of the 87 prisoners who screened positive for NDD and were further assessed, 70 met the study’s diagnostic criteria for ADHD, ASD or ID. Most of those with NDD (51 per cent) had previously gone unrecognised and a high proportion (51 per cent) were identified through staff- or self-referral to the study. Originality/value The study demonstrated that improving awareness and providing access to skilled, standardised assessment within a male prison can result in increased recognition and identification of NDD

    Production and decay of evolving horizons

    Full text link
    We consider a simple physical model for an evolving horizon that is strongly interacting with its environment, exchanging arbitrarily large quantities of matter with its environment in the form of both infalling material and outgoing Hawking radiation. We permit fluxes of both lightlike and timelike particles to cross the horizon, and ask how the horizon grows and shrinks in response to such flows. We place a premium on providing a clear and straightforward exposition with simple formulae. To be able to handle such a highly dynamical situation in a simple manner we make one significant physical restriction, that of spherical symmetry, and two technical mathematical restrictions: (1) We choose to slice the spacetime in such a way that the space-time foliations (and hence the horizons) are always spherically symmetric. (2) Furthermore we adopt Painleve-Gullstrand coordinates (which are well suited to the problem because they are nonsingular at the horizon) in order to simplify the relevant calculations. We find particularly simple forms for surface gravity, and for the first and second law of black hole thermodynamics, in this general evolving horizon situation. Furthermore we relate our results to Hawking's apparent horizon, Ashtekar et al's isolated and dynamical horizons, and Hayward's trapping horizons. The evolving black hole model discussed here will be of interest, both from an astrophysical viewpoint in terms of discussing growing black holes, and from a purely theoretical viewpoint in discussing black hole evaporation via Hawking radiation.Comment: 25 pages, uses iopart.cls V2: 5 references added; minor typos; V3: some additional clarifications, additional references, additional appendix on the Viadya spacetime. This version published in Classical and Quiantum Gravit
    corecore