The Postural Tachycardia Syndrome (POTS): Pathophysiology, Diagnosis & Management

Postural tachycardia syndrome (POTS), characterized by orthostatic tachycardia in the absence of orthostatic hypotension, has been the focus of increasing clinical interest over the last 15 years 1. Patients with POTS complain of symptoms of tachycardia, exercise intolerance, lightheadedness, extreme fatigue, headache and mental clouding. Patients with POTS demonstrate a heart rate increase of ≥30 bpm with prolonged standing (5-30 minutes), often have high levels of upright plasma norepinephrine (reflecting sympathetic nervous system activation), and many patients have a low blood volume. POTS can be associated with a high degree of functional disability. Therapies aimed at correcting the hypovolemia and the autonomic imbalance may help relieve the severity of the symptoms. This review outlines the present understanding of the pathophysiology, diagnosis, and management of POTS

Dynamic Demand Analysis of India Domestic Coffee Market

Coffee, although an important commodity in India agricultural exports, has faced fluctuating international prices and decreasing unit value realisation, especially in the post-reform period. Hence, domestic market for coffee cannot be neglected altogether. In fact, Coffee Board has proposed a promotional campaign to increase domestic demand for coffee. In this context, it becomes necessary to understand weather the emphasis should be on price incentives or nonprice factors. We estimate coffee demand for the Indian domestic market using the dynamic error-correction methodology (ECM). Results show that while demand for coffee is inelastic in the long-run, it is highly inelastic in the short-run. This suggests that Coffee Board may focus efforts on non-price factors rather than price incentives in their generic coffee promotional campaign.

Amplification of localized body forces in channel flows of viscoelastic fluids

The study of nonmodal amplification of distributed body forces in channel flows of viscoelastic fluids has provided useful insights into the mechanisms that may govern the initial stages of transition to elastic turbulence. However, distributed body forces are not easy to implement in experiments and so there is a need to examine amplification of localized body forces. In this work, we use the linearized governing equations to examine such amplification in Poiseuille flow of FENE-CR fluids. We first identify the wall-normal location at which the impulsive excitations experience the largest amplification and then analyze the kinetic energy of the fluctuations and the resulting flow structures. For both a Newtonian fluid at high Reynolds numbers and a viscoelastic fluid at low Reynolds numbers, the largest amplification occurs for disturbances that are located near the channel wall. Our analysis of the energy evolution shows that a localized body force in the spanwise direction has the largest impact and that the streamwise velocity component is most affected. For viscoelastic fluids we observe the development of vortical structures away from the source of impulsive excitation. This feature is less prominent in Newtonian fluids and it may provide a mechanism for triggering the initial stages of transition to elastic turbulence.Comment: 25 pages; 9 figure

Gene tree reconciliation: new developments in Bayesian concordance analysis with BUCKy

When phylogenetic trees inferred from different genes are incongruent, several methods are available to reconcile gene trees and extract the shared phylogenetic information from the sequence data. Bayesian Concordance Analysis, implemented in BUCKy, aims to extract the vertical signal and to infer clusters of genes that share the same tree topology. The new version of BUCKy includes a quartet-based estimate of the species tree with branch lengths in coalescent units

MULTILATERAL GOVERNANCE OF FISHERIES: MANAGEMENT AND COOPERATION IN THE WESTERN AND CENTRAL PACIFIC TUNA FISHERIES

The tuna resources of the Western and Central Pacific are the world's largest and most valuable fisheries of their type and are of significant economic importance to the Pacific island countries through whose waters they migrate. Two major concerns exist with the current governance of this fishery. First, Pacific island countries receive only a small share of the resource rents from the tuna fisheries. Second, the current management structure of the fisheries will not ensure the long-term sustainability of the resources. This paper derives a model to show that the sustainability of the resource can be improved when a single policymaker acts as Stackelberg leader and sets a tax, or an equivalent quantity instrument, to maximize rents from the resource. A practical institutional mechanism is presented that mimics the model's rent maximization outcome and that offers substantial benefits to both Pacific island countries and distant water fishing nations.Resource /Energy Economics and Policy,