The authors study the stability of a barotropic sinusoidal meridional flow on a b plane. Because of bottom drag and lateral viscosity, the system is dissipative and forcing maintains a basic-state velocity that carries fluid across the planetary vorticity contours; this is a simple model of forced potential vorticity mixing. When the Reynolds number is… (More)

We show that the geophysical β-effect strongly affects the linear stability of a sinusoidal Kolmogorov flow. If α denotes the angle between the flow direction and the planetary vorticity gradient then the critical Reynolds’ number, Rc(α, β), is zero for β = 0, provided that sin 2α = 0. In particular, the small β limit is discontinuous: limβ→0 Rc(α, β) = 0,… (More)

Empirical treatment is indicated for young children with febrile urinary tract infection (UTI). In this clinical setting, oral antibiotics are as safe and effective as intravenous therapy. The aim of this study was to investigate in children with febrile UTI whether there were longitudinal changes in the prevalence of bacteria and in the pattern of… (More)

We s h o w that the geophysical {eeect strongly aaects the linear stability of a sinu-soidal Kolmogorov ow. If denotes the angle between the ow direction and the planetary vorticity gradient then the critical Reynolds' number,R c (), is zero for 6 = 0, provided that sin 2 6 = 0. In particular, the small-limit is discontinuous: lim !0 R c () = 0, rather than… (More)