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1.
J Fish Biol ; 81(4): 1315-26, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22957872

RESUMEN

This study provides the first detailed information on the reproductive biology of the smooth butterfly ray Gymnura micrura. A total of 905 individuals were sampled, 377 of which were used for the reproductive study. Juveniles accounted for 75% of the sample, but all life cycle stages were present in the study area. The disc width at which 50% were mature (W(D50))was estimated at 269 and 405 mm for males and females, respectively. The W(D50V) (based on the onset of vitellogenesis) was estimated at 359 mm. Uterine fecundity (mean ±s.d. = 3·8 ± 1·3; range: 1-6) was positively correlated with female size. A 3564% gain in mean wet mass was observed from egg to full-term embryo in utero. Size at birth ranged from 135 to 175 mm W(D) (19·5 to 55·0 g), with a mean of 165·1 mm W(D) (43·3 g). The embryo sex ratio was not significantly different from 1:1. The ovaries of pregnant females were undergoing vitellogenesis during gestation, with females ready to ovulate soon after parturition. Gymnura micrura may have an asynchronous reproductive cycle, with females reproducing continuously throughout the year.


Asunto(s)
Reproducción/fisiología , Rajidae/fisiología , Animales , Tamaño Corporal/fisiología , Embrión no Mamífero/anatomía & histología , Femenino , Gónadas/anatomía & histología , Masculino , Razón de Masculinidad , Maduración Sexual/fisiología , Rajidae/anatomía & histología
2.
Food Chem Toxicol ; 46(11): 3493-500, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18804142

RESUMEN

Saccharomyces cerevisiae extract (SCE) is used in cosmetics since it can act in oxidative stress and improve skin conditions. This study investigated dermatological effects of cosmetic formulations containing SCE and/or vitamins A, C and E. The formulation studied was supplemented or not (F1: vehicle) with vitamins A, C and E esters (F2) or with SCE (F3) or with the combination of vitamins and SCE (F4). Formulations were patch tested on back skin of volunteers. For efficacy studies, formulations were applied on volunteers and transepidermal water loss (TEWL), skin moisture (SM), skin microrelief (SMR) and free radicals protection were analysed after 3h, 15 and 30 days of application. Volunteers were also asked about efficacy perception. It was observed that F4 provoked a slight erythema in one volunteer. All formulations enhanced forearm SM. Only F3 and F4 presented long term effects on SMR and showed higher texture values; F3 had the highest brightness values. Our results suggest that vitamins and SCE showed effects in SM and SMR. Only formulations containing SC had long term effects in the improvement of SMR. Thus, these kinds of evaluations are very important in cosmetics development to evaluate the best risk and benefit correlation.


Asunto(s)
Agua Corporal/metabolismo , Cosméticos/farmacología , Saccharomyces cerevisiae/química , Piel/efectos de los fármacos , Vitaminas/farmacología , Administración Cutánea , Adulto , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/farmacología , Cosméticos/administración & dosificación , Cosméticos/química , Relación Dosis-Respuesta a Droga , Combinación de Medicamentos , Cara , Femenino , Antebrazo , Humanos , Persona de Mediana Edad , Piel/metabolismo , Factores de Tiempo , Vitamina A/administración & dosificación , Vitamina A/farmacología , Vitamina E/administración & dosificación , Vitamina E/farmacología , Vitaminas/administración & dosificación
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