1,175 research outputs found

    Sensitivity of the Oceanic Turbulent Boundary Layer to Cyclic Insolation Change with Response Periods of 23 to 2.5 Ky: an Equatorial Atlantic Record for the Last 200 Ka

    Get PDF
    Time series of sea-surface temperature in cores sited beneath the region of maximum divergence centered on 10 degrees W are characterized by two sets of periodic signals. The dominant signal is centered on a period of 23 Ky and is coherent with and lags, approx. 2.5 Ky, the precessional component of orbitally controlled insolation. The subdominant periods occur between 4.0 and 2.5 Ky. Both sets of signals record variation in the seasonal intensity of oceanic divergence modulated by variation in tropical easterly intensity. The longer periods are a response to precessional forcing. The forcing responsible for the shorter periods is unknown

    Holomorphic factorization of determinants of Laplacians using quasi-Fuchsian uniformization

    Full text link
    For a quasi-Fuchsian group \Ga with ordinary set Ω\Omega, and Δn\Delta_{n} the Laplacian on \n differentials on \Ga\bk\Omega, we define a notion of a Bers dual basis ϕ1,...c,ϕ2d\phi_{1},...c,\phi_{2d} for kerΔn\ker\Delta_{n}. We prove that detΔn/det\det\Delta_{n}/\det , is, up to an anomaly computed by Takhtajan and the second author in \cite{TT1}, the modulus squared of a holomorphic function F(n), where F(n) is a quasi-Fuchsian analogue of the Selberg zeta Z(n). This generalizes the D'Hoker-Phong formula detΔn=cg,nZ(n)\det\Delta_{n}=c_{g,n}Z(n), and is a quasi-Fuchsian counterpart of the result for Schottky groups proved by Takhtajan and the first author in \cite{MT}.Comment: 15 page

    The BECOME=CAUSE hypothesis and the polysemy of get

    Get PDF
    This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.I propose a variant of the hypothesis that expressions often formalized with the inchoative operator become are really causative constructions without Causers. I test the claims in a detailed semantic and syntactic analysis of most uses of English get. This verb is of interest because, in most of its uses, it can be analyzed as a spellout of become (cause[−agentive] in my system), sometimes enriched with other (e.g., possessive, agentive, benefactive) predications.Claims include (i) that agentive structures like I got ready involve morpho-logically unmarked reflexivization/middle voice, (ii) that the semantic compo-sitionality of get-passives has been underestimated, (iii) that get sheds impor-tant light on the nature of directional PPs, (iv) that ditransitive get enriches our understanding of English double object constructions, (v) that voice heads may or may not introduce a Causer argument predetermined by the embedded predicate, (vi) that becomeandcause-type verbs can impose arbitrary selection restrictions on the secondary predicates with which they appear. The semantic analyses are expressed in abstract syntax, but can be translated into other frameworks.Peer Reviewe

    Behavioral responses of sub-adult Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus) to electromagnetic and magnetic fields under laboratory conditions

    Get PDF
    Electromagnetic fields (EMF) produced by high voltage (HV), submarine transmission cables leading from offshore wind energy generation facilities could affect foraging or migratory behaviors of electro-receptive fishes, including endangered Atlantic Sturgeon. However, no published studies have quantitatively evaluated the possible behavioral effects of EMF exposure on sturgeon during residence in coastal waters. This study evaluated behavioral responses by sub-adult Atlantic Sturgeon to electromagnetic and magnetic fields under controlled laboratory conditions. Fabricated EMF generators were used to emulate a range of field EMF conditions that migratory fishes could encounter in proximity to submarine HV sources. Sensor arrays and digital video recorders synoptically quantified EMF conditions and fish behaviors during experimental trials. This thesis will describe the unique, experimental EMF generator/sensor array, present results of the behavior study, and suggest implications of the findings for Atlantic Sturgeon management and conservation. 45 trials were conducted over the course of the study. Study fish were subjected to 3 different field strengths (5µT, 100 µT, 1000 µT), generated using both AC and DC current. Time spent in generated field area, number of passes through the field area, and swimming speed were used to quantify behavioral changes in test subjects. From the data collected and analyzed there was no evidence indicating a change in fish behavior due to the influence of field strengths, field orientations, or field types used during the study

    The cost-effectiveness of Antiretroviral Treatment in Khayelitsha, South Africa – a primary data analysis

    Get PDF
    BACKGROUND: Given the size of the HIV epidemic in South Africa and other developing countries, scaling up antiretroviral treatment (ART) represents one of the key public health challenges of the next decade. Appropriate priority setting and budgeting can be assisted by economic data on the costs and cost-effectiveness of ART. The objectives of this research were therefore to estimate HIV healthcare utilisation, the unit costs of HIV services and the cost per life year (LY) and quality adjusted life year (QALY) gained of HIV treatment interventions from a provider's perspective. METHODS: Data on service utilisation, outcomes and costs were collected in the Western Cape Province of South Africa. Utilisation of a full range of HIV healthcare services was estimated from 1,729 patients in the Khayelitsha cohort (1,146 No-ART patient-years, 2,229 ART patient-years) using a before and after study design. Full economic costs of HIV-related services were calculated and were complemented by appropriate secondary data. ART effects (deaths, therapy discontinuation and switching to second-line) were from the same 1,729 patients followed for a maximum of 4 years on ART. No-ART outcomes were estimated from a local natural history cohort. Health-related quality of life was assessed on a sub-sample of 95 patients. Markov modelling was used to calculate lifetime costs, LYs and QALYs and uncertainty was assessed through probabilistic sensitivity analysis on all utilisation and outcome variables. An alternative scenario was constructed to enhance generalizability. RESULTS: Discounted lifetime costs for No-ART and ART were US2,743andUS2,743 and US9,435 over 2 and 8 QALYs respectively. The incremental cost-effectiveness ratio through the use of ART versus No-ART was US1,102(951,102 (95% CI 1,043-1,210) per QALY and US984 (95% CI 913-1,078) per life year gained. In an alternative scenario where adjustments were made across cost, outcome and utilisation parameters, costs and outcomes were lower, but the ICER was similar. CONCLUSION: Decisions to scale-up ART across sub-Saharan Africa have been made in the absence of incremental lifetime cost and cost-effectiveness data which seriously limits attempts to secure funds at the global level for HIV treatment or to set priorities at the country level. This article presents baseline cost-effectiveness data from one of the longest running public healthcare antiretroviral treatment programmes in Africa that could assist in enhancing efficient resource allocation and equitable access to HIV treatment
    corecore