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A Delgado

Publications and source records attributed to A Delgado.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Using phosphorus concentration in the soil solution to predict phosphorus desorption to water.

The growing concerns about water eutrophication have made it urgent to restrict losses of phosphorus (P) from agricultural soils and to develop methods for predicting such losses. In this work, we used the paradigm of P sorption-desorption curves to confirm the hypothesis that the amount of dissolved reactive phosphorus (DRP) released to a dilute electrolyte tends to be proportional to the concentration of DRP in the soil solution raised to a power that decreases with increasing solution to soil ratio (W). The hypothesis was tested for a group of 12 widely ranging European agricultural soils fertilized with P in excess of crop needs. Phosphorus desorption was studied under near-static and turbulent conditions in laboratory experiments. The concentration of DRP in the 1:1 soil to water extract (P1:1) was used as a proxy for the DRP concentration in the soil solution. The amount of desorbed P was found to be correlated with P1:1 raised to a power that decreased from 0.7 to 0.9 at W=100 to 0.2 to 0.4 at W=10 000. Correlation was not improved by introducing additional variables related to P sorption-desorption properties. Olsen P was found to be of lower predictive value than P1:1. Also, the index of degree of soil saturation with phosphorus (DSSP) based on oxalate extraction failed to predict P desorption. The fact that P1:1 seemingly predicts P desorption accurately for a wide range of soils makes it potentially useful in areas of high soil diversity.

Absorption↗
PubMedDate not supplied

Influence of cycle ergometer characteristics on the adolescents' anaerobic abilities testing.

The present study examined whether the reported lower values of anaerobic abilities in children and adolescents, both in absolute and related to bodyweight values, as compared to adults can be explained, partially at least, by a non-optimal testing apparatus. So, they cannot express their anaerobic abilities. Specifically, we examined the force-velocity (F-V) relationship on a mechanical cycle ergometer, in 23 adolescents and 11 adults, with two wheels of very different weights: 6.3 kg (Wh6) and 18 kg (Wh18). A higher wheel inertia might explain a late reach or no reach of the true peak velocity and the maximal anaerobic power (PmaxAn). The adolescent group showed higher Vo (V for zero braking force) values with Wh6 (238 +/- 14 vs 223 +/- 16 rpm) (P < 0.001) than with Wh18. The absolute or relative PmaxAn values for this group were slightly higher, but not significantly, with Wh6 (10.6 +/- 2.2 vs 10.2 +/- 1.9 W/kg). The delay to reach peak velocity was higher with Wh18 than with Wh6 (P < 0.001) in the two groups. In addition, the delay was always higher (P < 0.001) in the adolescent group compared to the adult group for both wheels. This suggests that the fatigue related to the observed late reach and the rapid decrease of power over time could lead to an underestimation of the PmaxAn peak in children.

Adolescent↗
PubMedDate not supplied

[Ultrasonic diagnosis of prostatic adenocarcinoma. Prospective study of a sample of 159 patients].

We studied the value of transrectal echography as the diagnostic means of prostate pathology. We carried out a prospective analysis of a sample of 159 patients, on whom we have anatomopathological documentation which we use as the reliability control for the clinical exploration by means of rectal touch and ultrasonography with transrectal transducer. We have obtained 137 prostate fibromuscular hyperplasias, 3 inflammatory pathologies and 19 adenocarcinomas. A 100% sensitivity in the echographic diagnosis of prostate adenocarcinoma was achieved for this sample.

Adenocarcinoma↗