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Three-dimensional echocardiography (3DE) is the most accurate cardiac ultrasound technique to assess cardiac structure. 3DE has shown close correlation with cardiac magnetic resonance imaging (CMR) in various populations. There is limited data on the accuracy of 3DE in athletes and its value in detecting alterations during follow-up. Indexed left and right ventricular end-diastolic volume (LVEDVi, RVEDVi), end-systolic volume, ejection fraction (LVEF, RVEF) and left ventricular mass (LVMi) were assessed by 3DE and CMR in two-hundred and one competitive endurance athletes (79% male) from the Pro@Heart trial. Sixty-four athletes were assessed at 2 year follow-up. Linear regression and Bland–Altman analyses compared 3DE and CMR at baseline and follow-up. Interquartile analysis evaluated the agreement as cardiac volumes and mass increase. 3DE showed strong correlation with CMR (LVEDVi r = 0.91, LVEF r = 0.85, LVMi r = 0.84, RVEDVi r = 0.84, RVEF r = 0.86 p < 0.001). At follow up, the percentage change by 3DE and CMR were similar (∆LVEDVi r = 0.96 bias − 0.3%, ∆LVEF r = 0.94, bias 0.7%, ∆LVMi r = 0.94 bias 0.8%, ∆RVESVi r = 0.93, bias 1.2%, ∆RVEF r = 0.87 bias 0.4%). 3DE underestimated volumes (LVEDVi bias − 18.5 mL/m2, RVEDVi bias − 25.5 mL/m2) and the degree of underestimation increased with larger dimensions (Q1vsQ4 LVEDVi relative bias − 14.5 versus − 17.4%, p = 0.016; Q1vsQ4 RVEDVi relative bias − 17 versus − 21.9%, p = 0.005). Measurements of cardiac volumes, mass and function by 3DE correlate well with CMR and 3DE accurately detects changes over time. 3DE underestimates volumes and the relative bias increases with larger cardiac size. [ABSTRACT FROM AUTHOR]

To support the development of protective water resources management strategies, a 3D hydrodynamic model was applied to the Little Manatee River (LMR) to evaluate the effects of reducing river flow and drought on the Estuarine Residence Time (ERT). ERT is an important indicator for estuarine environmental quality. The Little Manatee River is a small tidal river estuary with a yearly mean gaged freshwater inflow of 4.8 m/s. The hydrodynamic model was calibrated and verified by using two continuous data sets for a six month period. Model simulations were conducted for 17 river inflow scenarios. Among the flow scenarios, 13 scenarios were within a flow range from 0.26 m/s to 10 m/s total freshwater inflow. A regression equation ( R = 0.98) fitted by a power-law function was derived from analysis of the hydrodynamic modeling results to correlate model predicted ERT to total river inflow, though ERT can be predicted from gaged freshwater inflow as well. The study indicates that the estuarine residence time reaches 53.3 days under an extreme drought condition of 0.26 m/s total inflow. When river inflow falls below the critical flow (4 m/s or less), further flow reductions can cause the substantial increases of ERT by a factor of 2 to 10 times. This suggests that the management of flow reductions is particularly critical when total river flows are 4 m/s or less if adverse impacts to the water quality and ecological characteristics of the Little Manatee River are to be avoided. [ABSTRACT FROM AUTHOR]

The water age in a tidal river in Florida, Little Manatee River, has been investigated in this study by the application of a three-dimensional hydrodynamic model. In response to a pulse dye release in the upper end of the river boundary, the hydrodynamic model determines the water age for a given location by recording the time for the dye to reach the given river location. The hydrodynamic model uses horizontal curvilinear orthogonal grids to represent the complex river system that includes several bayous and tributaries. The model has was calibrated and verified in previous study by using two continuous data sets for a 6 month period. Satisfactory model verifications indicate that the hydrodynamic model is capable of quantifying the mixing and transport process for calculating the water age in the tidal river. For 17 freshwater inflow scenarios in the Little Manatee River, the hydrodynamic model was applied to simulate water ages along the main channel of the river at 2-km interval. Flow rates in the 17 scenarios varying from 0.26 to 76.56 m3/s cover the range of the observed flows in the Little Manatee River. Water ages from model predictions range from the minimum 1.2 days under the maximum 76.56 m3/s inflow condition to the 50 days under the minimum 0.26 m3/s inflow condition. Empirical regression equations at three selected stations, with the correlation coefficient R2 above 0.96, were derived from numerical model simulations to correlate water ages to freshwater inflows. The empirical water-age equation derived from hydrodynamic model simulations can be used to provide quick and low-cost estimations of water ages in response to various inflow scenarios for studying physical–chemical and biological processes in the river. [ABSTRACT FROM AUTHOR]

The Southwest Florida Water Management District has implemented a management approach for unimpounded rivers that limits withdrawals to a percentage of streamflow at the time of withdrawal. The natural flow regime of the contributing river is considered to he the baseline for assessing the effects of withdrawals. Development of the percent-of-flow approach has emphasized the interaction of freshwater inflow with the overlap of stationary and dynamic habitat components in tidal river zones of larger estuarine systems. Since the responses of key estuarine characteristics (e.g.. isohaline locations, residence times) to freshwater inflow are frequently nonlinear, the approach is designed to prevent impacts to estuarine resources during sensitive low-inflow, periods and to allow water supplies to become gradually more available as inflow increases, A high sensitivity to variation at low inflow extends to many invertebrates and fishes that move upstream and downstream in synchrony with inflow. Total numbers of estuarine-resident and estuarine-dependent organisms have hero found to decrease during low-inflow periods. including mysids, grass shrimp, and juveniles of the hay anchovy and sand seatrout. The interaction of freshwater inflow with seasonal processes, such as phytoplankton production and the recruitment of fishes to the tidal-river nursery', indicates that withdrawal percentages during the springtime should be most restrictive. Ongoing efforts are oriented toward refining percentage withdrawal limits among seasons and floss ranges to account fur shifts in the responsiveness of estuarine processes to reductions in freshwater inflow. [ABSTRACT FROM AUTHOR]

The role of the telephone in medical practice is important, but often problematic. Mistakes in telephone diagnosis and triage can have severe consequences. An effective office system can reduce liability risks, and in some cases telephone contact can substitute for office visits. Internists feel unprepared to provide telephone care. Therefore, residency education needs to focus on documentation, consultant availability, and performance feedback. Research should focus on improving outcomes, reimbursement issues, and technologic advances. This article describes internists' telephone interactions with ambulatory patients, preparation for telephone medicine, and aspects of office telephone systems and makes comparisons with other primary care fields. [ABSTRACT FROM AUTHOR]

The Lower Hillsborough River, Florida is a short (16 km) riverine estuary which has a dam located at its upstream end. Salinity below thedam is influenced by freshwater that flows over or through the structure. Depending on location in the estuary, the response of salinity to changes in upstream freshwater inflows is normally not instantaneous, but lags behind the freshwater release. An analytical approach and a laterally averaged two-dimensional hydrodynamic model were used to examine the response time of salinity in the Lower Hillsborough River to changes in freshwater inflows from the upstream reservoir. A series of case studies were conducted using the model to determine how salinity in the river within one kilometer below the dam would respond to changes in freshwater inflows. The model results suggest that the time lag of salinity in the river depends on whether the upstream freshwater inflows are increasing or decreasing, as well as their magnitude. While the time lag for salinity is about six to eight days fordecreasing inflows, it is much shorter for increasing inflows depending on the magnitude of the flow release. [ABSTRACT FROM AUTHOR]

This paper pursues the lead of Bart K. Holland in utilizing classic literature as a guide to the pharmacologic potentialities of natural products. Instead of focusing on European texts, how ever, American medicinal plants are examined through the work of the influential naturalist Constantine S. Rafinesque (1783--1840). Rafinesque is discussed with special attention to his activities as a medical botanist. In particular, the plant species monographed in the main section of his Medical Flora of the United States (1828--1830) are studied for theirhistorical and current use as medicinal agents. The results are tabulated and presented in a bar graph. The study concludes that Rafinesque was a progressive therapist whose Medical Flora is a promising guide for phytopharmacuetical prospecting with North American plants. [ABSTRACT FROM AUTHOR]