Nonhydrostatic effects in numerical modeling of mesoscale convective systems and baroclinic waves

The present investigation is concerned with the role of convection upon mesoscale modeling results, particularly when the grid resolution becomes small enough that there is not a clear scale separation between the explicitly resolved circulations and the parameterized clouds. In those situations, the vertical accelerations in explicitly resolved circulations become strong enough that the hydrostatic assumption may no longer be valid. These concerns arise from interests in improving mesoscale modeling per se and in improving the subgrid-scale parameterizations in global models. The hydrostatic and the nonhydrostatic options of the Colorado State University Regional Atmospheric Modeling System were used to simulate dry gravity currents in two dimensions, using several different horizontal grid sizes. With horizontal grid intervals of 10 km or less, nonhydrostatic simulations produce wider and colder heads and weaker but wider forced updrafts than do the hydrostatic simulations. Comparing the hydrostatic and nonhydrostatic models show that the difference between the vertical mass fluxes is much less than the difference between the vertical velocities. When the grid is fine enough to resolve the head of the gravity current, horizontal convergence at the gust front extends upwards almost to the head of the cold air. Vertical mass flux in the forced updraft at the front varies with horizontal grid size mainly as a function of the height of the simulated head. For coarser grids, which do not resolve the head, vertical mass flux at all heights decreases with increasing horizontal grid size. A comparison on nonhydrostatic simulations with horizontal grid intervals of 1 km and 2 km illustrates how decreasing the grid size does not necessarily increase the intensity of the resolved circulation. The smaller grid enables the simulated gravity current to entrain a bubble of warm air behind the head, which results in a weaker circulation with a shorter head and weaker updraft

Information theory and representation in associative word learning

A significant portion of early language learning can be viewed as an associative learning problem. We investigate the use of associative language learning based on the principle that words convey Shannon information about the environment. We discuss the shortcomings in representation used by previous associative word learners and propose a functional representation that not only denotes environmental categories, but serves as the basis for activities and interaction with the environment. We present experimental results with an autonomous agent acquiring language

Carnival Bingo

Photo of big cityhttps://scholarsjunction.msstate.edu/cht-sheet-music/3889/thumbnail.jp

Prognostic Markers and Management Strategies in Systemic Amyloidosis

BACKGROUND: Systemic amyloidosis is increasing in prevalence but remains a rare, potentially fatal disorder characterised by the misfolding of autologous proteins into an abnormal fibrillar form. Outcomes are dependent on amyloid subtype. AIMS: To improve diagnosis, management and understanding of prognosis of patients with amyloidosis. In terms of diagnosis, I will evaluate the diagnostic sensitivity of screening biopsies in AL and ATTR amyloidosis. I will also assess prognostic markers at baseline, and following treatment, in a large UK cohort of uniformly treated patients with a view to developing a new staging system for AL amyloidosis incorporating novel prognostic markers. I will focus on functional markers of prognosis such as longitudinal strain on echocardiogram and the 6-minute walk test. I shall also explore treatment outcomes with novel therapies (ixazomib-lenalidomidedexamethasone and daratumumab) in AL amyloidosis and the impact of chemotherapy on quality of life in patients with AL amyloidosis at a variety of timepoints. Finally, I will assess the value and outcomes of organ transplantation in patients with AL amyloidosis and apolipoprotein A-I amyloidosis. RESULTS AND CONCLUSION: Screening biopsies are valuable, particularly in AL amyloidosis, to avoid higher-risk target organ biopsies. Longitudinal strain, measured via echocardiogram, is prognostic at baseline and following chemotherapy in AL amyloidosis. It is independent of Mayo criteria and can be incorporated into a new prognostic staging system alongside cardiac biomarkers both at baseline and in evaluating response to treatment. The 6-minute walk test distance is also prognostic at baseline, whilst improvement in walk test at 12 months predicts survival. Health-related quality of life improves in patients achieving a complete haematological response or cardiac organ response and is an important marker in the holistic characterisation of treatment response. Ixazomib-lenalidomide-dexamethasone and Daratumumab monotherapy are both effective treatment options in AL amyloidosis. Renal transplantation is associated with very encouraging outcomes in carefully selected patients with AL amyloidosis. In Apolipoprotein A-I amyloidosis, renal, hepatic and cardiac transplantations all have a role and are associated with good long term outcomes

On Sojourn Times in the Finite Capacity M/M/1M/M/1 Queue with Processor Sharing

We consider a processor shared $M/M/1$ queue that can accommodate at most a finite number $K$ of customers. We give an exact expression for the sojourn time distribution in the finite capacity model, in terms of a Laplace transform. We then give the tail behavior, for the limit $K\to\infty$, by locating the dominant singularity of the Laplace transform.Comment: 10 page

A Quantitative Investigation of Entrainment and Detrainment in Numerically Simulated Convective Clouds

A method is developed which uses numerical tracers to make accurate diagnoses of entraimnent and detrainment rates and of the properties of the entrained and detrained air in numerically simulated clouds. The numerical advection scheme is modified to make it nondispersive, as required by the use of the tracers. Tests of the new method are made, and an appropriate definition of clouds is selected. Distributions of mixing fractions in the model consistently show maximums at the end points, for nearly undilute environmental air or nearly undilute cloud air, with a uniform distribution between. The cumulonimbus clouds simulated here entrain air that had been substantially changed by the clouds, and detrained air that is not necessarily representative of the cloud air at the same level