Which functional processes control the short-term effect of grazing on net primary production in grasslands?

Grazing has traditionally been viewed as detrimental to plant growth, but it has been proposed that under certain conditions, grazing may lead to compensatory or overcompensatory growth. However, comprehensive information on the relative role of the main functional processes controlling the response of net primary production (NPP) to grazing is still lacking. In this study, a modelling approach was used to quantify the relative importance of key functional processes in the response of annual canopy NPP to grazing for a West African humid grassland.

[Percutaneous closure of patent ductus arteriosus: results and costs compared to surgical closure].

The comparison of the clinical results and costs of the two methods of closure of patient ductus arteriosus was undertaken in two comparable groups of 40 patients treated in the same period in the same hospital. After transcatheter closure there was a 9% residual shunt rate at 3 years, the 2 patients with a residual continuous murmur being operated secondarily. The only complication was severe haemolysis which regressed after transcatheter ablation of the prosthesis.

[Double-chamber right ventricle, aortic subvalvular stenosis and interventricular septal defect. Apropos of 12 cases].

The authors report 12 cases of double-chamber right ventricle associated with discrete subaortic stenosis and ventricle septal defect. The statistics derived from 3,292 surgical reports of congenital heart diseases operated on at the Marie-Lannelongue Surgical Center over an 8 years period show that this association is 7 times more frequent than the law of chance. Twenty-two per cent of double-chamber right ventricles had an associated discrete subaortic stenosis and, in 9% of cases of subaortic stenosis a double-chamber right ventricle was observed.

[Percutaneous mitral valvulotomy: comparison of 2 techniques in 100 matched-pair patients].

The results of percutaneous mitral valvulotomy by the Double Balloon and the Inoue Balloon were compared in 100 patients referred to Marie-Lannelongue Hospital between 7/11/86 and 8/3/91, paired for age, sex and echocardiographic features of the mitral valve. The transvalvular diastolic pressure gradient at catheterisation or Doppler echocardiography decreased significantly and similarly with the two techniques: -65 +/- 19% versus -64 +/- 15% (p = 0.10) and -66 +/- 22% versus -58 +/- 23% (p = 0.