Distributed Global Debris Thickness Estimates Reveal Debris Significantly Impacts Glacier Mass Balance.

Supraglacial debris affects glacier mass balance as a thin layer enhances surface melting, while a thick layer reduces it. While many glaciers are debris-covered, global glacier models do not account for debris because its thickness is unknown. We provide the first globally distributed debris thickness estimates using a novel approach combining sub-debris melt and surface temperature inversion methods. Results are evaluated against observations from 22 glaciers. We find the median global debris thickness is ∼0.15 ± 0.06 m. In all regions, the net effect of accounting for debris is a reduction in sub-debris melt, on average, by 37%, which can impact regional mass balance by up to 0.40 m water equivalent (w.e.) yr-1. We also find recent observations of similar thinning rates over debris-covered and clean ice glacier tongues is primarily due to differences in ice dynamics. Our results demonstrate the importance of accounting for debris in glacier modeling efforts.

Kinetic and metabolic aspects of enalapril action.

Enalapril is a long-acting, sulphydryl-free, ACE inhibitor whose humoral and hypotensive effects are maximal at 4-8 h and remain detectable at 24 h after a single dose. Serum profiles after chronic dosing of enalapril show little accumulation of the active diacid metabolite, enalaprilat. Comparison between the observed and predicted steady-state urinary recoveries of enalaprilat yields an effective accumulation half-life of approximately 11 h. In normotensive subjects, enalapril increases renal blood flow whilst leaving glomerular filtration unchanged irrespective of the state of sodium balance. Similarly under conditions of salt loading and salt depletion, a biphasic saluretic response is seen which parallels the excretory maxima for unchanged enalapril (1-2 h) and enalaprilat (4-8 h) suggesting direct interference by the drug moieties with tubular NaCl reabsorption. During the period of maximal enalapril action, uricosuria and phosphaturia are seen, supporting a direct action of enalaprilat on proximal tubular handling of these anions. Detailed documentation of the chronic metabolic effects of enalapril remains incomplete. A small rise in plasma potassium concentrations can occur but overt hyperkalaemia is unlikely in the absence of gross renal failure. Continued dosing is associated with a fall in plasma uric acid concentrations; plasma prolactin concentrations remain unaltered.