Sinus-node function was characterized in 13 patients during cardiac catheterization by the introduction of progressively premature atrial depolarizations. Curves relating the extent of sinus-node depression following these premature depolarizations and their degree of prematurity were constructed. The maximum extent of sinus-node depression following premature depolarizations and A-V-nodal and ...

In X-rays, the Galactic Centre (GC) Region appears as a complex of diffuse thermal and non-thermal X-ray emission intermixed with a population of luminous discrete sources. Here we present some new findings from the XMM-Newton GC survey, focusing particularly on Sgr A, Sgr A East, the Radio Arc region, and a newly discovered X-ray non-thermal filament.

In this work we describe the results obtained with S3590-06 and ion-implanted diodes for alpha particle spectrometry. Satellite peaks were also investigated in order to identify not only the origin of these phenomena, but also the importance of the guard ring region on their relative intensities. The preliminary results indicate that the true cause of the spurious satellite peaks might be assoc...

The uptake of pyruvate by yeast was studied under a variety of conditions of temperature, extracellular concentration, O(2) pressure, and pH. It was shown that physical diffusion adequately explains the permeation of undissociated pyruvic acid into the outer and inner regions of the cell. The entrance of pyruvate ion into the outer region appears to take place by the same process. The passage o...

heat and mass transfer, in this paper, is considered in one-row heat exchanger, that fins are hotter than air flow and water is added to fins. related governing equations are derived by analyzing a two-dimension model in a unique cell of a heat exchange. these equations are numerically solved by finite difference method. heat transfer and efficiency under partially wet surface are calculated by...

Nesting cavities are often a limited resource that multiple species use. There is an ongoing discussion on whether invasive cavity nesting birds restrict the availability of this key limited resource. While the answer to this question has important conservation implications, little experimental work has been done to examine it. Here, we aimed to experimentally test whether alien cavity nesting ...

The main objective of this study was to assess factors affecting early entrance and later exit of herders from summer rangelands. The study population consisted of heads of Nomads in Kouhdasht region, Lorestan province, Iran. According to Cochran formula among 1038 Nomadic families, 310 families were selected with stratified random sampling in 2015. In order to assess validity, expert's opinion...

Stingless bees (Meliponini) construct their own species-specific nest entrance. The size of this entrance is under conflicting selective pressures. Smaller entrances are easier to defend; however, a larger entrance accommodates heavier forager traffic. Using a comparative approach with 26 species of stingless bees, we show that species with greater foraging traffic have significantly larger ent...