Deriva nictemeral de macroinvertebrados en el rio Llobregat (Barcelona)

A study on the qualitative and quantitative coniposition of macroinvertebrate drift in the Llobregat river ( N E Spain) is put fonvard. Samples were taken hourly during a 24 hour period in august 1982. The samples were taken with a net of 625 cm. of filtering surface and an opening mesh size of 500 microns, which íiltered 72,1 m3 /h. and collected 75.719 individuals during the sampling period. That means a drift rate of 1.224 indiv./h. and a drift density of 17 indi/m3 . 8 I0/o of the organismes collected were exuviae, mainly pupal chironomid skins (54%) and nimphal ephemeroptera moults (27(Ynj. The remainder percentage of living organisms represents a drift rate of 227 indiv./h. and a drift density of 3.14 indiv./m3. These are intermediate values ifwe compare them with the data published. Sixty per cent of the living drift were chiroiiomids. 17.5 '1 ephemeroptera and 10 (%1 trichoptera; these being the niost iniportant groups. Ofthe 87 species identified in those groups 23 were common in al1 the (7 1 ) samples (Table 1)

Características clínicas y evolución de los pacientes con hipertensión arterial refractaria

Un 5-10% de hipertensos no controlan las cifras de TA a pesar de tomar 3 o más fármacos (uno de ellos un diurético), definiendo la HTA refractaria. Estos pacientes presentan un riesgo cardiovascular más elevado. Se trata de un estudio descriptivo y observacional de 101 casos con TA sistólica por MAPA &140 mmHg. El 75% presenta patrón nictemeral alterado. El 54% presentó algún nuevo evento cardiovascular. La HVI es un factor predictor de mortalidad cardiovascular. La causa principal de HTA refractaria es la esencial, siendo la IRC la etiología más prevalente de HTA secundaria.