ABSTRACT
Within the oak woodlands of California there is often a distinct shift in the botanical composition between the open grassland and the herbaceous understory beneath oak canopy. Botanical sampling at two woodland sites indicated that the annual grass Bromus diandrus was dominant under deciduous blue oak canopy, while a congener, Bromus hordeaceus, was dominant in open grassland. We examined the relative importance of congeneric competition and edaphic factors in creating these differences in species distribution in two separate field experiments that manipulated both congeneric and intraspecific competition, as well as soil type. We used the demographic measure of relative reproductive rate as an index of population growth. In general, demographic performance correctly predicted the distribution of the two annual grasses in the field. Our results indicate that reduced abundance of B. hordeaceus under canopy reflects the negative effects of competition with B. diandrus. In contrast, B. diandrus is little affected by competition from B. hordeaceus. The reduced abundance of B. diandrus in open grassland may result, in part, from its inability to adapt as well as B. hordeaceus to lower nutrient availability in soils of the open grassland.
ABSTRACT
Computer aided data processing of the results of surgery in 504 patients with mitral (and mitral + aortic + tricuspid) valvular disease, operated on by the Szeged cardiosurgery group between 1966-1983 are discussed. Late results after valve surgery are investigated from the point of view of survival time, functional state and social rehabilitation. Statistical evaluation of postoperative complications and the functional life-time of the Cross-Jones prosthesis are reported. The functional rehabilitation following the operation is mathematically assessed.
Subject(s)
Heart Valve Prosthesis , Mitral Valve Insufficiency/surgery , Mitral Valve Stenosis/surgery , Follow-Up Studies , Humans , Life Expectancy , Mitral Valve , Mitral Valve Insufficiency/mortality , Mitral Valve Stenosis/mortality , Postoperative Complications/mortality , Quality of LifeABSTRACT
The author have carried out scintigraphic measurements of the heart in order to diagnose the presence of an exudative pericarditis 50 times in 26 dialyzed uremic patients. Within the one year's observation 13 patients had an exudative pericarditis from the beginning on. In 8 cases a regression of the exudation could be observed. The examination has a low risk for the patient and is suitable to demonstrate clinically relevant pericardial liquid accumulation.
Subject(s)
Pericardial Effusion/diagnosis , Radionuclide Imaging , Uremia/complications , Humans , Pericardial Effusion/etiologyABSTRACT
Two dialyzed uraemic patients were subjected to partial pericardiectomy because of haemorrhagic pericarditis and pericardial tamponade. Seventeen and nine months, respectively, after the operation the patients have still been under intermittent home haemodialysis.
