9,311 research outputs found

    ESTIMATING THE BENEFITS OF REGIONALIZING EMERGENCY MEDICAL SERVICE PROVISION

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    Local area governments have experienced increasingly stringent budget constraints in recent years. Innovations in service delivery provide one avenue for increasing the effectiveness of resource allocations. This paper explores the potential savings available from regionalizing emergency medical service provision. A mixed integer programming model incorporating peak demand considerations is used to minimize service cost given a desired maximum response time. Changes in the weighted average response time measure the quality degradation required to attain the savings from cooperative provision. The results indicate that the benefits are substantial but that distribution of these gains is a possible barrier to implementation.Health Economics and Policy, Public Economics,

    Inhibitory control as a mediator of bidirectional effects between early oppositional behavior and maternal depression.

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    Maternal depression is an established risk factor for child conduct problems, but relatively few studies have tested whether children's behavioral problems exacerbate mothers' depression or whether other child behavioral characteristics (e.g., self-regulation) may mediate bidirectional effects between maternal depression and child disruptive behavior. This longitudinal study examined the parallel growth of maternal depressive symptoms and child oppositional behavior from ages 2 to 5; the magnitude and timing of their bidirectional effects; and whether child inhibitory control, a temperament-based self-regulatory mechanism, mediated effects between maternal depression and child oppositionality. A randomized control trial of 731 at-risk families assessed children annually from ages 2 to 5. Transactional models demonstrated positive and bidirectional associations between mothers' depressive symptoms and children's oppositional behavior from ages 2 to 3, with a less consistent pattern of reciprocal relations up to age 5. Mediation of indirect mother-child effects and child evocative effects depended on the rater of children's inhibitory control. Findings are discussed in regard to how child evocative effects and self-regulatory mechanisms may clarify the transmission of psychopathology within families

    β-diketonate versus β-ketoiminate:the importance of a ferrocenyl moiety on improving the anticancer potency

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    Herein we present a library of fully characterized beta-diketonate and beta-ketoiminate compounds that are functionalized with a ferrocenyl moiety. Their cytotoxic potential has been determined by screening against human breast adenocarcinomas (MCF-7 and MDA-MB-231), human colorectal carcinoma p53 wild type (HCT116 p53(+/+)) and normal human prostate (PNT2) cell lines. The ferrocenyl beta-diketonate compounds are more than 18 times more cytotoxic than the ferrocenyl beta-ketoiminate analogues. Against MCF-7, compounds functionalized at the meta position are up to nine times more cytotoxic than when functionalized at the para position. The ferrocenyl beta-diketonate compounds have increased selectivity towards MCF-7 and MDA-MB-231, with several complexes having selectivity index (SI) values that are more than nine times (MCF-7) and more than six times (MDA-MB-231) that of carboplatin. The stability of these compounds in dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) has been assessed by NMR spectroscopy and mass spectrometry studies, and the compounds show no oxidation of the iron center from Fe-II to Fe-III. Cytotoxicity screening was performed in both DMSO and DMF, with no significant differences observedin their potency

    Spatial Models to Account for Variation in Observer Effort in Bird Atlases

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    To assess the importance of variation in observer effort between and within bird atlas projects and demonstrate the use of relatively simple conditional autoregressive (CAR) models for analyzing grid-based atlas data with varying effort. Pennsylvania and West Virginia, United States of America. We used varying proportions of randomly selected training data to assess whether variations in observer effort can be accounted for using CAR models and whether such models would still be useful for atlases with incomplete data. We then evaluated whether the application of these models influenced our assessment of distribution change between two atlas projects separated by twenty years (Pennsylvania), and tested our modeling methodology on a state bird atlas with incomplete coverage (West Virginia). Conditional Autoregressive models which included observer effort and landscape covariates were able to make robust predictions of species distributions in cases of sparse data coverage. Further, we found that CAR models without landscape covariates performed favorably. These models also account for variation in observer effort between atlas projects and can have a profound effect on the overall assessment of distribution change. Accounting for variation in observer effort in atlas projects is critically important. CAR models provide a useful modeling framework for accounting for variation in observer effort in bird atlas data because they are relatively simple to apply, and quick to run

    Generation of graph-state streams

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    We propose a protocol to generate a stream of mobile qubits in a graph state through a single stationary parent qubit and discuss two types of its physical implementation, namely, the generation of photonic graph states through an atom-like qubit and those of flying atoms through a cavity-mode photonic qubit. The generated graph states fall into an important class that can hugely reduce the resource requirement of fault-tolerant linear optics quantum computation, which was previously known to be far from realistic. In regard to the flying atoms, we also propose a heralded generation scheme, which allows for high-fidelity graph states even under the photon loss.Comment: Accepted for publication at PRA Rapid Communication

    On Gauge Invariance and Ward Identities for the Wilsonian Renormalisation Group

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    We investigate non-Abelian gauge theories within a Wilsonian Renormalisation Group approach. The cut-off term inherent in this approach leads to a modified Ward identity (mWI). It is shown that this mWI is compatible with the flow and that the full effective action satisfies the usual Ward identity (WI). The universal 1-loop beta-function is derived within this approach and the extension to the 2-loop level is briefly outlined.Comment: 4 pages, latex, talk presented by J. M. Pawlowski at QCD 98, Montpellier, July 2-8, 1998; to be published in Nucl. Phys. B (Proc. Suppl.), reference update

    On General Axial Gauges for QCD

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    General Axial Gauges within a perturbative approach to QCD are plagued by 'spurious' propagator singularities. Their regularisation has to face major conceptual and technical problems. We show that this obstacle is naturally absent within a Wilsonian or 'Exact' Renormalisation Group approach and explain why this is so. The axial gauge turns out to be a fixed point under the flow, and the universal 1-loop running of the gauge coupling is computed.Comment: 4 pages, latex, talk presented by DFL at QCD'98, Montpellier, July 2-8, 1998; to be published in Nucl. Phys. B (Proc. Suppl.

    Thermodynamic Studies of [H_(2)Rh(diphosphine)_2]^+ and [HRh(diphosphine)_(2)(CH_(3)CN)]^(2+) Complexes in Acetonitrile

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    Thermodynamic studies of a series of [H_(2)Rh(PP)_2]^+ and [HRh(PP)_(2)(CH_(3)CN)]^(2+) complexes have been carried out in acetonitrile. Seven different diphosphine (PP) ligands were selected to allow variation of the electronic properties of the ligand substituents, the cone angles, and the natural bite angles (NBAs). Oxidative addition of H_2 to [Rh(PP)_2]^+ complexes is favored by diphosphine ligands with large NBAs, small cone angles, and electron donating substituents, with the NBA being the dominant factor. Large pK_a values for [HRh(PP)_(2)(CH_(3)CN)]^(2+) complexes are favored by small ligand cone angles, small NBAs, and electron donating substituents with the cone angles playing a major role. The hydride donor abilities of [H_(2)Rh(PP)_2]^+ complexes increase as the NBAs decrease, the cone angles decrease, and the electron donor abilities of the substituents increase. These results indicate that if solvent coordination is involved in hydride transfer or proton transfer reactions, the observed trends can be understood in terms of a combination of two different steric effects, NBAs and cone angles, and electron-donor effects of the ligand substituents
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