RESUMEN
Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Here, using reanalysis data and the outputs of a regional climate model, we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean, was responsible for a poleward shift of runoff, albedo and surface temperature records over the Greenland during the summer of 2015. New records of monthly mean zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5,700±50 m isohypse over the Arctic were associated with the formation and persistency of a cutoff high. The unprecedented (1948-2015) and sustained atmospheric conditions promoted enhanced runoff, increased the surface temperatures and decreased the albedo in northern Greenland, while inhibiting melting in the south, where new melting records were set over the past decade.
RESUMEN
Spasticity may result in part from segmental spinal disinhibition. We determined the content and specific activity of glycine (the putative neurotransmitter thought to mediate spinal postsynaptic inhibition) and serine (the probable precursor of glycine) in feline spastic spinal cord following the intra-aortic administration of two labelled precursors of glycine--14C-D-glucose and 14C-L-serine. The specific activities of both glycine and serine were significantly reduced in the ventromedial, central, and dorsal spinal gray matter in spastic animals. Glycine content remained at control values but serine content increased in spastic spinal cord. This study suggests that glycine turnover decreases in spasticity, owing to its diminished release, and supports neurophysiologic evidence of a decrement in postsynaptic inhibition.