No description available.

No description available.

No description available.

No description available.

No description available.

Numerical experiments are used to study the wind- and buoyancy-modulated along-shore circulation over the Texas-Louisiana continental shelf inshore of 50-m water depth. Most attention is given to circulation in the non-summer flow regime. A major focus of this study is on a unique along-shore flow phenomenon – convergent along- shore flows, which is controlled jointly by wind forcing and buoyancy fluxes from the Mississippi-Atchafalaya river plume. The second problem addresses the forcing effect of buoyancy on the general along-shore circulation pattern over the shelf in non-summer. The convergent along-shore flows are characterized by down-coast flow from the northern shelf encountering up-coast flow from the southern shelf. This phenomenon is explored for both weather band and seasonal timescales. For the weather band, investigations are focused on non-summer convergent events. The formation of convergent flows is primarily caused by along-coast variation in the along-shore component of wind forcing, which in turn is due to the curvature of the Texas-Louisiana coastline. In general, along-shore currents are well correlated with along-shore winds. However, the points of convergence of currents and winds are not co-located; but rather, points of convergence of currents typically occur down-coast of points of convergence of wind. This offset is mainly caused by buoyancy forcing that forces down-coast currents and drives the point of convergence of currents further down-coast. No specific temporal shift pattern is found for the weather-band convergence, whereas monthly

No description available.

Chronic obstructive pulmonary disease (COPD) is characterized by an expiratory flow limitation, as well as an evident reduced exercise capacity compared to that of healthy age-matched individuals. Clearly, the expiratory flow limitation plays a significant role in this exercise intolerance; however, the extent of the contributions of other systemic factors remains unclear. More specifically, there is little data thus far on the role of blood flow delivery as a possible exercise limitation in COPD, especially in light of the potential interactions between cardiac output (Qc) and pulmonary hyperinflation. Thus, the purpose of this study was to compare the slope of the Qc versus oxygen uptake (VO 2) response through several submaximal cycling loads in patients with moderately severe COPD with that of age-matched healthy control subjects (CTRL). Also examined was the possibility that ventilatory constraints such as dynamic hyperinflation contribute to an abnormal Qc response. Cardiac output was measured using the CO2-rebreathing equilibrium technique during baseline conditions and cycling at 20, 40 and 65% of peak power in 17 COPD (Age: 64 +/- 8 yrs; FEV1/FVC: 37 +/- 11%; FEV1: 41 +/- 15% predicted) and 10 age-matched CTRL subjects. Inspiratory capacity (IC) was also measured for the determination of dynamic hyperinflation during the steady state exercise bouts. The results indicate that while the absolute Qc values are lower in COPD than in CTRL during moderately intense (65% peak power) cycling (11.30 +/- 2.38 vs. 15.63 +/- 2.15 L⋅min -1, p < 0.01), likely due to their lower exercise metabolic demand, the Qc/VO2 response to increasing levels of exercise intensity is normal or hyperdynamic in COPD. Indeed, the majority of patients with COPD exhibited Qc/VO2 slopes greater than 7.0, which may be indicative of a peripheral muscle bioenergetic disturbance that may drive the need for greater oxygen delivery, and thus result in an exaggerated ce

No description available.

No description available.