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S Parent

Publications and source records attributed to S Parent.

21 records · Page 2Linked to original sources

The French connection: some contributions of French-language research in the post-Piagetian era.

This article presents French-speaking researchers' contribution to the field of differential developmental psychology. Following a brief review of key Piagetian ideas pertaining to his conceptualization of individual differences, the core of the article traces methodological and theoretical transformations that were necessary for understanding individual differences within a general theory of cognitive development. On a methodological level, French-speaking researchers went from standardizing Piaget's clinical method to constructing developmental scales and operational tests. On a theoretical level, Reuchlin's writings guided Longeot, and several other French (Lautrey and Bideaud) and Genevan (de Ribaupierre and Rieben) researchers into a scientific quest for a genuine integration of differential and developmental psychology. We present an overview of the pluralistic and multidimensional model of cognitive functioning and development that emerged from the work of the French-Swiss team of researchers. Concluding remarks focus on the actual research agendas of researchers interested in resolving the challenging issue of understanding relationships between inter- and intraindividual differences and general tendencies in cognitive development.

Child↗

Cryopreservation alters the levels of the bull sperm surface protein P25b.

Fertility of frozen-thawed bull sperm is reduced by cryopreservation. Freezing-thawing procedures can result in as much as a sevenfold fertility decrease. Sperm mortality and loss of motility do not fully explain the reduced fertility of cryopreserved semen; they may be partially explained by the loss of sperm surface proteins, which are necessary for fertilization. We have previously identified P25b, a sperm surface protein, which is associated with the fertility index of bulls used for artificial insemination. Using Western blotting techniques, we have evaluated P25b levels before and after cryopreservation of bull spermatozoa in extenders based on either egg yolk or milk. Long storage periods (28 days) in liquid nitrogen results in a threefold decrease of P25b levels associated with cryopreserved versus fresh spermatozoa. Over a short storage period (3-7 days), a stable P25b level was observed on spermatozoa cryopreserved in extender containing either egg yolk or milk. A decrease in P25b levels associated with spermatozoa was observed after 5 days of storage in egg yolk extender, whereas a significant decrease was observed after 14 days of sperm storage in milk extender (P < .05). Therefore, the loss of P25b may be responsible, at least in part, for the decrease in fertility following the freezing-thawing procedure of bull semen. Moreover, the cryopreservation extender used may have different effects on the loss of sperm surface proteins after even brief storage periods in liquid nitrogen. Considering that a sperm protein similar to P25b exists in humans (P34H), these results may have significant clinical applications in which frozen semen is used.

Animals↗

What are the small bowel obstructions to operate and how to do it?

Small bowel obstruction is one of the main surgical emergencies. CT scan is today the best exam to detect occlusions requiring an urgent surgical procedure. It also specify the cause of the obstruction. Post-operative adhesions are the first etiology and justify 3.5%-5% of laparotomies in Western Countries. Recently, small bowel obstructions due to adhesions could be treated by a laparoscopic procedure. The authors report a series of 35 patients presenting an acute small bowel obstruction treated by laparoscopy. The laparoscopic procedure was successful in 70% of cases when occlusion was due to acute adhesions. Compared with open procedure, coelioscopy had an immediate benefit on intestinal mobility re-establishment and hospital stay. The morbidity was 4.5% with no mortality. CT has to be part of pre-operative check-up in front of a small bowel obstruction in order to propose a laparoscopic procedure when postoperative adhesions are suspected.

Adolescent↗