Three-dimensional echocardiography and 2D-3D speckle tracking imaging in chronic pulmonary hypertension. diagnostic accuracy in detecting hemodynamic signs of RV failure

Background and objective. Our aim was to compare three-dimensional (3D) and 2D and 3D speckle tracking (2D-STE, 3D-STE) echocardiographic parameters with conventional right ventricular (RV) indexes in patients with chronic pulmonary hypertension (PH), and investigate whether these techniques could result in better correlation with hemodynamic variables indicative of heart failure. Methods. Seventy-three adult patients (mean age, 53±13 years; 44% male) with chronic PH of different etiologies were studied by echocardiography and cardiac catheterization (25 precapillary PH from pulmonary arterial hypertension, 23 obstructive pulmonary heart disease, and 23 postcapillary PH from mitral regurgitation). Thirty healthy subjects (mean age, 54±15 years; 43% male) served as controls. Standard 2D measurements (RV-FAC -fractional area change-, TAPSE -tricuspid annular plane systolic excursion-) and mitral and tricuspid tissue Doppler annular velocities were obtained. RV 3D volumes, and global and regional ejection fraction (3D-RVEF) were determined. RV strains were calculated by 2D-STE and 3D-STE. Results. RV 3D global-free-wall longitudinal strain (3DGFW-RVLS), 2D global-free-wall longitudinal strain (GFW-RVLS), apical-free-wall longitudinal strain (AFW-RVLS), basal-free-wall longitudinal strain (BFW-RVLS), and 3D-RVEF were lower in patients with pre-capillary PH (p<0.0001) and post-capillary PH (p<0.01) compared to controls. 3DGFW-RVLS (HR 4.6, 95% CI 2.79-8.38, p=0.004) and 3D-RVEF (HR 5.3, 95% CI 2.85-9.89, p=0.002) were independent predictors of mortality. ROC curves showed that the thresholds offering an adequate compromise between sensitivity and specificity for detecting hemodynamic signs of RV failure were 39% for 3D-RVEF (AUC 0.89), -17% for 3DGFW-RVLS (AUC 0.88), -18% for GFW-RVLS (AUC 0.88), -16% for AFW-RVLS (AUC 0.85), 16mm for TAPSE (AUC 0.67), and 38% for RV-FAC (AUC 0.62). Conclusions. In chronic PH, 3D, 2D-STE and 3D-STE parameters indicate global and regional RV dysfunction that is associated with RV failure hemodynamics better than conventional echo indices

Oyster Aquaculture Site Selection Using Landsat 8-derived Sea Surface Temperature, Turbidity, and Chlorophyll a.

Remote sensing data is useful for selection of aquaculture sites because it can provide water-quality products mapped with no cost to users. However, the spatial resolution of most ocean color satellites is too coarse to provide usable data within many estuaries. The more recently launched Landsat 8 satellite has both the spatial resolution and the necessary signal to noise ratio to provide temperature, as well as ocean color derived products along complex coastlines. The state of Maine (USA) has an abundance of estuarine indentations (~3,500 miles of tidal shoreline within 220 miles of coast), and an expanding aquaculture industry, which makes it a prime case-study for using Landsat 8 data to provide products suitable for aquaculture site selection. We collected the Landsat 8 scenes over coastal Maine, flagged clouds, atmospherically corrected the top-of-the-atmosphere radiances, and derived time varying fields (repeat time of Landsat 8 is 16 days) of temperature (100 m resolution), turbidity (30 m resolution), and chlorophyll-a (30 m resolution). We validated the remote-sensing-based products at several in situ locations along the Maine coast where monitoring buoys and programs are in place. Initial analysis of the validated fields revealed promising areas for oyster aquaculture. The approach used and the data collected to date show potential for other applications in marine coastal environments, including water quality monitoring and ecosystem management

Old Times in Saco

Opening Paragraph: The history of Saco practically begins with the discovery of the Saco River in 1603. Some few adventurers had cruised along the coast of New England previous to that year, and since it is probable that fishermen visited the inlets of southwestern Maine before those waters were generally known to explorers, it is not unreasonable to suppose that white men set foot upon the shores of Saco Bay prior to the beginning of the XVIIth century. There is, however, no satisfactory evidence in support of such a conjecture and history must be said to begin with the date above given.https://digicom.bpl.lib.me.us/books_pubs/1017/thumbnail.jp

Efeitos do indutor ressonante não linear sobre o comportamento dos conversores quase-ressonantes com comutação sob tensão nula

Tese (doutorado) - Universidade Federal de Santa Catarina. Centro TecnologicoEste trabalho apresenta uma técnica para reduzir a sobretensão, aumentar a faixa de carga e reduzir a faixa de freqüência de chaveamento, nos Conversores Quase-Ressonantes, com comutação sob tensão nula. Esta técnica também é aplicada ao conversor em ponte completa modulado por largura de pulso, com comutação sob tensão nula, para aumentar sua faixa de carga. Esta técnica consiste na substituição do indutor ressonante linear por um indutor ressonante não linear. Inicialmente, esta técnica é aplicada ao Conversor BUCK quase-ressonante, com comutação sob tensão nula. É demonstrado, que com a substituição, do indutor ressonante linear pelo não linear, os objetivos propostos são alcançados. Um estudo da influência do indutor ressonante não linear, nos valores médios e eficazes, de tensão e corrente, é realizado. O comportamento da recuperação reversa, do diodo de roda livre, na presença do indutor ressonante não linear, é considerado. O estudo de outros conversores quase-ressonantes, com comutação sob tensão nula, com indutor ressonante não linear, é feito nos capítulos seguintes. A tentativa de trabalhar com o indutor ressonante não linear, com freqüência de chaveamento em 1MHz, é realizada com o Conversor em Meia Ponte quase-ressonante, com comutação sob tensão nula. O conversor em Ponte Completa modulado por largura de pulso, com comutação sobtensão nula, com indutor não linear, é analizado

Effect of a home based, low intensity, physical exercise program in older adults dialysis patients: A secondary analysis of the EXCITE trial

Background: Older adults dialysis patients represent the frailest subgroup of the End Stage Renal Disease (ESRD) population and physical exercise program may mitigate the age-related decline in muscle mass and function. Methods: Dialysis patients of the EXCITE trial aged > 65 years (n = 115, active arm, n = 53; control arm, n = 62) were submitted in random order to a home based, low intensity physical exercise program. At baseline and 6 months after exercise training 6-min walking distance (6MWD) and 5-time sit-to-stand test (5STS) were performed, and quality of life (QoL) was tested. Results: The training program improved both the 6MWD (6-months: 327 \ub1 86 m versus baseline: 294 \ub1 74 m; P < 0.001) and the 5STS time (6-months: 19.8 \ub1 5.6 s versus baseline: 22.5 \ub1 5.1 s; P < 0.001) in the exercise group whereas they did not change in the control group (P = 0.98 and 0.25, respectively). The between-arms differences (6 months-baseline) in the 6MWD (+ 34.0 m, 95% CI: 14.4 to 53.5 m) and in the 5STS time changes (- 1.9 s, 95% CI: -3.6 to - 0.3 s) were both statistically significant (P = 0.001 and P = 0.024, respectively). The cognitive function dimension of QoL significantly reduced in the control arm (P = 0.04) while it remained unchanged in the active arm (P = 0.78) (between groups difference P = 0.05). No patient died during the trial and the training program was well tolerated. Conclusions: This secondary analysis of the EXCITE trial shows that a home-based, exercise program improves physical performance and is well tolerated in elderly ESRD patients. Trial registration: The trial was registered in ClinicalTrials.Gov (Clinicaltrials.gov identifier: NCT01255969) on December 8, 2010

Les "Radisson" de l'historiographie revus et corrigés

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Fitness for entering a simple exercise program and mortality: A study corollary to the exercise introduction to enhance performance in dialysis (Excite) trial EXCITE working group

Background/Aims: In this corollary analysis of the EXCITE study, we looked at possible differences in baseline risk factors and mortality between subjects excluded from the trial because non-eligible (n=216) or because eligible but refusing to participate (n=116). Methods: Baseline characteristics and mortality data were recorded. Survival and independent predictors of mortality were assessed by Kaplan-Meier and Cox regression analyses. Results: The incidence rate of mortality was higher in non-eligible vs. eligible non-randomized patients (21.0 vs. 10.9 deaths/100 persons-year; P<0.001). The crude excess risk of death in non-eligible patients (HR 1.96; 95% CI 1.36 to 2.77; P<0.001) was reduced after adjustment for risk factors which differed in the two cohorts including age, blood pressure, phosphate, CRP, smoking, diabetes, triglycerides, cardiovascular comorbidities and history of neoplasia (HR 1.60; 95% CI 1.10 to 2.35; P=0.017) and almost nullified after including in the same model also information on deambulation impairment (HR 1.16; 95% CI 0.75 to 1.80; P=0.513). Conclusions: Deambulation ability mostly explains the difference in survival rate in non-eligible and eligible non-randomized patients in the EXCITE trial. Extending data analyses and outcome reporting also to subjects not taking part in a trial may be helpful to assess the representability of the study population