1,166 research outputs found

    Estuarine research report 41

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    A review of management documents and peer reviewed literature was undertaken to evaluate the level of protection intertidal shellfish are given from vehicle and horse users on sand beaches. Database searches were conducted to find policies that related to vehicle and/or horse management on sand beaches. Using findings from peer reviewed literature, policies were assessed for how shellfish populations could be impacted. For example, policies that concentrate vehicle traffic into specific areas which contain shellfish were considered to have negative impacts because literature has shown heavy traffic has detrimental effects. Internationally, policies controlling vehicle and horse users utilise five common options: complete bans, seasonal closures, permits, area-based and zone-based designation. These management options usually focus on erosion prevention and ensuring safety of users with little consideration of ecological impacts. When ecology is considered, this concentrates on protecting the more visible species (e.g. nesting birds) rather than infaunal biota. Shellfish were not directly mentioned in any management policies that control vehicle and horse users. Shellfish in New Zealand are protected similarly to the rest of the world, and no policies designed to directly benefit these types of animals. Vehicle and horse users on sand beaches are controlled with bylaws; the creation and implementation of which depends on each local authority. Management of these users therefore does not occur uniformly over New Zealand regions. Where bylaws are in place, these generally confine vehicle and horse users to the intertidal zone; areas that shellfish, such as tuatua (Paphies donacina) and toheroa (P. ventricosa), are abundant. Seasonal beach restrictions are also generally rare, with the amount or type of traffic used on the beach unregulated. In order to successfully protect intertidal species such as tuatua, scientific information which identifies and describes the distribution, vulnerable life-stages and the relationship between beach traffic and shellfish vulnerability is needed

    A versatile, high through-put, bead-based phagocytosis assay for Plasmodium falciparum

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    Abstract Antibody-mediated phagocytosis is an important immune effector mechanism against Plasmodium falciparum-infected erythrocytes (IE); however, current phagocytosis assays use IE collected from infected individuals or from in vitro cultures of P. falciparum, making them prone to high variation. A simple, high-throughput flow cytometric assay was developed that uses THP-1 cells and fluorescent beads covalently-coupled with the malarial antigen VAR2CSA. The assay is highly repeatable, provides both the overall percent phagocytosis and semi-quantitates the number of antigen-coupled beads internalized

    Carvedilol alone or in combination with digoxin for the management of atrial fibrillation in patients with heart failure?

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    AbstractObjectivesThis study examined the relative merits of digoxin, carvedilol, and their combination for the management of patients with atrial fibrillation (AF) and heart failure (HF).BackgroundIn patients with AF and HF, both digoxin and beta-blockers reduce the ventricular rate, and both may improve symptoms, but only beta-blockers have been shown to improve prognosis. If combined therapy is not superior to beta-blockers alone, treatment of patients with HF and AF could be simplified by stopping digoxin.MethodsWe enrolled 47 patients (29 males; mean age 68 years) with persistent AF and HF (mean left ventricular ejection fraction [LVEF] 24%) in a randomized, double-blinded, placebo-controlled study. In the first phase of the study, digoxin was compared with the combination of digoxin and carvedilol (four months). In the second phase, digoxin was withdrawn in a double-blinded manner in the carvedilol-treated arm, thus allowing a comparison between digoxin and carvedilol (six months). Investigations were undertaken at baseline and at the end of each phase.ResultsCompared with digoxin alone, combination therapy lowered the ventricular rate on 24-h ambulatory electrocardiographic monitoring (p < 0.0001) and during submaximal exercise (p < 0.05), whereas LVEF (p < 0.05) and symptom score (p < 0.05) improved. In phase 2, there was no significant difference between digoxin alone and carvedilol alone in any variable. The mean ventricular rate rose and LVEF fell when patients switched from combination therapy to carvedilol alone. Six-minute walk distance was not significantly influenced by any therapy.ConclusionsThe combination of carvedilol and digoxin appears generally superior to either carvedilol or digoxin alone in the management of AF in patients with HF

    Effect of time at temperature on wild poliovirus titers in stool specimens

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    AbstractBackgroundThe effect of transport temperature on the viability of poliovirus in stool specimens from paralyzed cases has not been tested. Quality assurance of programmatic indicators will be necessary in the final phase of polio eradication.ObjectiveTo estimate the effect of time at elevated temperatures on wild poliovirus titers in stool specimens.MethodsWe exposed aliquots of pooled wild poliovirus type 1 specimens to elevated temperatures (27°C, 31°C, and 35°C) for varying time periods up to 14 days. We determined the virus titer of these aliquots and created decay curves at each temperature to estimate the relationship between time at temperature and virus titer.ResultsWe found significantly different slopes of decay at each temperature. The negative slopes increased as the temperature increased.ConclusionsWhile poliovirus in stool remains relatively stable at moderately elevated temperature, transport at higher temperatures could impact sample integrity and virus isolation results

    Gravitational dipole radiations from binary systems

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    We investigate the possibility of generating sizeable dipole radiations in relativistic theories of gravity. Optimal parameters to observe their effects through the orbital period decay of binary star systems are discussed. Constraints on gravitational couplings beyond general relativity are derived.Comment: One comment added, accepted for publication in Phys. Rev.

    Alternative approach to b>sγb->s \gamma in the uMSSM

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    The gluino contributions to the C7,8C'_{7,8} Wilson coefficients for b>sγb->s \gamma are calculated within the unconstrained MSSM. New stringent bounds on the δ23RL\delta^{RL}_{23} and δ23RR\delta^{RR}_{23} mass insertion parameters are obtained in the limit in which the SM and SUSY contributions to C7,8C_{7,8} approximately cancel. Such a cancellation can plausibly appear within several classes of SUSY breaking models in which the trilinear couplings exhibit a factorized structure proportional to the Yukawa matrices. Assuming this cancellation takes place, we perform an analysis of the b>sγb->s \gamma decay. We show that in a supersymmetric world such an alternative is reasonable and it is possible to saturate the b>sγb->s \gamma branching ratio and produce a CP asymmetry of up to 20%, from only the gluino contribution to C7,8C'_{7,8} coefficients. Using photon polarization a LR asymmetry can be defined that in principle allows for the C7,8C_{7,8} and C7,8C'_{7,8} contributions to the b>sγb->s \gamma decay to be disentangled. In this scenario no constraints on the ``sign of μ\mu'' can be derived.Comment: LaTeX2e, 23 pages, 7 ps figure, needs package epsfi

    A Generalized Fluctuation-Dissipation Theorem for Nonlinear Response Functions

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    A nonlinear generalization of the Fluctuation-Dissipation Theorem (FDT) for the n-point Green functions and the amputated 1PI vertex functions at finite temperature is derived in the framework of the Closed Time Path formalism. We verify that this generalized FDT coincides with known results for n=2 and 3. New explicit relations among the 4-point nonlinear response and correlation (fluctuation) functions are presented.Comment: 34 pages, Revte

    Softening the Supersymmetric Flavor Problem in Orbifold GUTs

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    The infra-red attractive force of the bulk gauge interactions is applied to soften the supersymmetric flavor problem in the orbifold SU(5) GUT of Kawamura. Then this force aligns in the infra-red regime the soft supersymmetry breaking terms out of their anarchical disorder at a fundamental scale, in such a way that flavor-changing neutral currents as well as dangerous CP-violating phases are suppressed at low energies. It is found that this dynamical alignment is sufficiently good compared with the current experimental bounds, as long as the diagonalization matrices of the Yukawa couplings are CKM-like.Comment: 15 pages,4 figure

    Large Scale Structure Formation with Global Topological Defects. A new Formalism and its implementation by numerical simulations

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    We investigate cosmological structure formation seeded by topological defects which may form during a phase transition in the early universe. First we derive a partially new, local and gauge invariant system of perturbation equations to treat microwave background and dark matter fluctuations induced by topological defects or any other type of seeds. We then show that this system is well suited for numerical analysis of structure formation by applying it to seeds induced by fluctuations of a global scalar field. Our numerical results are complementary to previous investigations since we use substantially different methods. The resulting microwave background fluctuations are compatible with older simulations. We also obtain a scale invariant spectrum of fluctuations with about the same amplitude. However, our dark matter results yield a smaller bias parameter compatible with b2b\sim 2 on a scale of 20Mpc20 Mpc in contrast to previous work which yielded to large bias factors. Our conclusions are thus more positive. According to the aspects analyzed in this work, global topological defect induced fluctuations yield viable scenarios of structure formation and do better than standard CDM on large scales.Comment: uuencoded, compressed tar-file containing the text in LaTeX and 12 Postscript Figures, 41 page
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