A baroclinic western boundary current over a continental slope

Baroclinic flow over a western continental slope is investigated using a simple model in which inertia is completely neglected and the temperature of the ocean depends only on horizontal position. Solutions of this model are also solutions of the three-dimensional equations without inertia. This model is arguably the simplest model in which the Joint Effect of Baroclinicity and Relief (JEBAR) can affect the mass transport on the slope. Offshore, we suppose that a classical double-gyre circulation exists, in which the subpolar gyre is colder than the subtropical gyre. Using asymptotic expansions based on small viscosity and small thermal diffusivity, we show analytically that a thin baroclinic current, or front, forms on the slope. The baroclinic current flows across the slope from south to north and shallow to deep. Recirculating gyres are formed on both flanks of the current, and the extent to which both the baroclinic current and the gyres resemble the observed flow in the Western North Atlantic is discussed

A simple model of the ‘joint effect of baroclinicity and relief’ on ocean circulation

We offer a simple model for studying the joint effect of baroclinicity and relief (jebar) on large-scale ocean circulation, based upon the planetary geostrophic equations. Applying a Galerkin approximation to the buoyancy equation, and asssuming that the temperature diffusion and vertical stratification are weak, we obtain a simple relation between the ocean temperature and the streamfunction ψ for the vertically-averaged horizontal transport. Substituting this relation back into the vertically-averaged vorticity equation yields a single, generally nonlinear equation for ψ, in which jebar corresponds to a clockwise ‘advection’ of ψ along the continental slope (for the realistic case of temperature increasing with ψ). Numerical solutions resemble those obtained by Salmon (1994) using a more accurate model, and provide a physically transparent explanation for the northward excursion of the Gulf Stream along the western continental slope observed in the previous study

Weed Control in Rice.

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Weed Control in Rice.

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Three-dimensional acoustic scattering by vortical flows. II. Axisymmetric scattering by Hill’s spherical vortex

The general theory of Part I is applied to the the specific case of scattering of a wave incident along the axis of Hill’s spherical vortex. The full asymptotic solution to the initial-value problem is calculated. Results agree with the general approach, showing that the conditions required for the latter to hold apply in the case of Hill’s spherical vortex

Health Care Inflation and It\u27s Implications for Monetary Policy

Motivated by recent findings on the cyclical movement of both health and health spending, we construct a general equilibrium model that distinguishes health care demand from the demand for other goods. Using this model, we are able to generate inflation dynamics and cyclicality of health that match the US data. When the model is subjected to an expansionary monetary policy shock, it yields different output and inflation responses compared with a two-sector model with homogeneous demand. We show that the trade-off between leisure and health spending plays an important role in model dynamics. The model further predicts different degrees of inflation stabilization across sectors when a shift in the monetary policy occurs

Blood Pressure Changes Following Antihypertensive Medication Reduction, by Drug Class and Dose Chosen for Withdrawal: Exploratory Analysis of Data From the OPTiMISE Trial

Aims: Deprescribing of antihypertensive drugs is recommended for some older patients with polypharmacy, but there is little evidence to inform which drug (or dose) should be withdrawn. This study used data from the OPTiMISE trial to examine whether short-term outcomes of deprescribing vary by drug class and dose of medication withdrawn. Methods: The OPTiMISE trial included patients aged ≥80 years with controlled systolic blood pressure (SBP; <150 mmHg), receiving ≥2 antihypertensive medications. This study compared SBP control, mean change in SBP and frequency of adverse events after 12 weeks in participants stopping one medication vs. usual care, by drug class and equivalent dose of medication withdrawn. Equivalent dose was determined according to the defined daily dose (DDD) of each medication type. Drugs prescribed below the DDD were classed as low dose and those prescribed at ≥DDD were described as higher dose. Outcomes were examined by generalized linear mixed effects models. Results: A total of 569 participants were randomized, aged 85 ± 3 years with controlled blood pressure (mean 130/69 mmHg). Within patients prescribed calcium channel blockers, higher dose medications were more commonly selected for withdrawal (90 vs. 10%). In those prescribed beta-blockers, low dose medications were more commonly chosen (87 vs. 13%). Withdrawal of calcium channel blockers was associated with an increase in SBP (5 mmHg, 95%CI 0–10 mmHg) and reduced SBP control (adjusted RR 0.89, 95%CI 0.80–0.998) compared to usual care. In contrast, withdrawal of beta-blockers was associated with no change in SBP (−4 mmHg, 95%CI −10 to 2 mmHg) and no difference in SBP control (adjusted RR 1.15, 95%CI 0.96–1.37). Similarly, withdrawal of higher dose medications was associated with an increase in SBP but no change in BP control. Withdrawal of lower dose medications was not associated with a difference in SBP or SBP control. There was no association between withdrawal of specific drug classes and adverse events. Conclusion: These exploratory data suggest withdrawal of higher dose calcium channel blockers should be avoided if the goal is to maintain BP control. However, low dose beta-blockers may be removed with little impact on blood pressure over 12-weeks of follow-up. Larger studies are needed to confirm these associations