Cardiac resynchronization therapy is not commonly used in the early postoperative period in pati ents undergoing cardiac surgery who have left ventricular (LV) dysfunction and a history of heart failure. We performed a prospective randomized clinical trial to compare atrial synchronous right ventricular (DDD RV) and biventricular (DDD BIV) pacing within 72 hours after cardiac surgery in patients with an EF ≤ 35 %, a QRS interval longer than 120 msec and who had LV dyssynchrony detected by real-time three-dimensional echocardiography (RT3DE). Epicardial pacing was provided by a modified Medtronic INSYNC III pacemaker. An LV epicardial pacing lead was implanted on the latest activated segment of the LV based on RT3DE. The study included 18 patients with ischemic heart diseas e, with or without valvular heart disease (14 men, 4 women, average age 71 years). Patients undergoing DDD BIV pacing had a statistically significant greater CO and CI (CO 6.7±1.8 l/min, CI 3.4±0.7 l/min/m²) than patients undergoing DDD RV pacing (CO 5.5±1.4 l/min, CI 2.8±0.7 l/min/m²), p<0.001. DDD BIV paci ng in the early postoperative period after cardiac surgery corrects LV dyssynchrony and has better hemodynamic results than DDD RV pacing., F. Straka ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Halting and reversing declines of black grouse populations in Britain represents a major conservation challenge. Programmes of dedicated management aiming to benefit black grouse have been introduced on several sites and areas across the species’ British range. These initiatives generally employ various managements, most aimed at improving habitat conditions, but some at reducing direct sources of mortality. Black grouse populations appear to respond to such conservation initiatives, with increases in numbers following the introduction of management in all six cases examined. However, these increases were not always sustained, and the frequent lack of control sites and baseline data means that there is limited ability to assess the full impact of management, and to distinguish management effects from the effects of coincident environmental variation. Similarly, it is difficult to identify the specific managements critical to producing black grouse response. Evidence exists for benefits of reducing large herbivore densities and of reducing generalist predator abundance, although these may be temporary in the case of herbivore reductions. Variation in annual productivity appeared to be a major determinant of population trends at two sites where productivity estimates were available, suggesting that responses to management may often arise via effects on productivity.
Tomato and pepper leaves were clipped with black leaf clips for dark adaptation under solar radiation in the late spring or early summer 2010 in southern Italy. The leaves showed highly variable maximum PSII quantum yield (Fv/Fm = 0.026-0.802) using a continuous-excitation fluorometer Pocket PEA. These results were confirmed using the modulated fluorometer FMS1 on tomato leaves in mid summer, with Fv/Fm as low as 0.222 ± 0.277 due to nearly equal minimum (F0) and maximum (Fm) fluorescence emission. A significant clip effect on Fv/Fm occurred after only 12 (tomato) or 25 (pepper) min. Increasing the leaf temperature from 25 to 50°C reportedly induced an F0 increase and Fm decrease so that Fv/Fm approached zero. The hypothesis that black leaf clips overheated under intense solar irradiance was verified by shrouding the clipped leaves with aluminum foil. In clipped leaves of pepper, Fv/Fm with the black clip/Pocket-PEA was 0.769 ± 0.025 (shrouded) and as low as 0.271 ± 0.163 (nonshrouded), the latter showing a double F0 and 32% lower Fm. An 8% clip effect on Fv/Fm was observed with the white clip/FMS1. To avoid the clip effect in high irradiance environments, Fv/Fm measurements with black clip/Pocket PEA system required leaf dark adaptation with
radiation-reflecting shrouds. It would be useful if manufacturing companies could develop better radiation-reflecting leaf clips for the Pocket PEA fluorometer. and P. Giorio.