Student Self-Efficacy, Classroom Engagement, and Academic Achievement: Comparing Three Theoretical Frameworks.

Student self-efficacy, behavioral engagement, and emotional engagement are key factors for academic achievement. Research has yet to identify the developmental cascades linking these four constructs. Three theoretical frameworks, i.e., Self-Efficacy Theory, the Self-System Model of Motivational Development, and Expectancy-Value Theory, suggest different nexus. Following 671 students (51.8% girls) from their 4th to 6th grade, this study aims to assess competing hypotheses from these three frameworks in math. Three cross-lag models were tested to test each theoretical framework. A fourth and final model was tested to include the significant paths from the previous models. Mediation paths were also tested. Results mainly support assumptions from Self-Efficacy Theory, that is student self-efficacy and academic achievement are mutually associated from 4th to 6th grades. Some of the propositions of Expectancy-Value Theory were also supported. Self-efficacy was associated with later emotional engagement and academic achievement. However, emotional engagement in 5th grade was negatively associated with achievement in 6th grade and was not associated with behavioral engagement. Assumptions from the Self-System Model were not supported by the data. Testing the fourth model revealed an unexpected developmental cascade: 5th-grade self-efficacy mediated the association between 4th-grade achievement and 6th-grade emotional engagement. This last finding may have great implications for young adolescents as emotional engagement is an indicator of student well-being and intrinsic value of learning. Implications for theory validation and intervention targets for adolescents are discussed.

[Fetal blood sampling for karyotype using echoguided puncture of the cord. Study of 103 pregnancies]. / Prélèvement de sang foetal pour caryotype par ponction échoguidée du cordon. 103 grossesses étudiées.

Subcutaneous ultrasound guided puncture of the umbilical cord was carried out in order to obtain samples of blood in 103 fetuses. This was done to get the result of the karyotype quickly, i.e. in 72 hours. The indications were for diagnosis, particularly of malformations (63 cases) or intra-uterine growth retardation (24 cases). A small proportion of the indications were those for failures to carry out amniocentesis early or for checking on mosaics that were obtained after the culture of amniotic fluid cells. In 88% of the cases it was possible to obtain a karyotype and the results were checked with the sex of the fetus and the karyotype that had been obtained from amniocentesis. There were 11 abnormalities diagnosed. The chief indication of chromosome abnormality is fetal malformation. Because the result are obtained so quickly cordocentesis should replace late amniocentesis, at present when looking for fetal abnormalities.

[A colonic structure in the placenta: a simple teratoma coaetans or ectopic differentiation?]. / Une structure colique à localisation placentaire: teratome coaetans simplifié ou différenciation ectopique?

A cylindrical structure which was closed on either side and covered by the amnion was found in a placenta. Histological examination showed well differentiated wall of large intestine with sympathetic plexus. Several hypothesis are discussed: teratoma, fetus acardiacus amorphus, anomalous differentiation of the yolk sac.

[Principle and practice of in vitro fertilization. Role in the treatment of female sterility]. / Principe et réalisation de la fécondation in vitro. Place dans le traitement de la stérilité féminine.

In vitro fertilization (IVF) and embryo transfer (ET) appear to constitute a revolution in the reproductive sciences rather than merely a new technique in the treatment of sterility. Principle of IVF: IVF accomplishes in vitro the process than normally occurs in the oviduct between the ovulation of oocyte II and embryo implantation in the endometrium. This 4 day period (under normal conditions in the woman) involves 4 steps: recovery, fertilization, segmentation and transport. Performance of IVF: Recovery of the oocytes: The oocytes are recovered under celioscopic or echographic observation when they have completed cytoplasmic maturation and their first meiosis. A precise monitoring of ovulation (spontaneous or induced) should be performed using estrogen and LH assays. IVF provides an opportunity for evaluating the methods of ovulation induction and monitoring, as a function of the maturation of the oocytes recovered. Fertilization: When the oocyte has achieved maturing after several hours of incubation, fertilization is obtained 15 h contact with washed and capacitated spermatozoa (100 000/ml). This step is highly dependent on gametocyte quality: oocyte maturity and fecundity of spermatozoa, which can be estimated from the percentage of survival in the insemination medium. Segmentation occurs in culture at pH 7.28 in the presence of 5 per cent CO2 at 37 degrees C (pronucleus 15th, 2 blastomeres 26 h, 4-8 blastomeres 52 h). Embryo transfer is carried out when an embryo is present at 52 h. Only 1/10 of the embryo transfers result in successful implantation, which depends on the quality of the embryo; the quality can only be indirect criteria.(ABSTRACT TRUNCATED AT 250 WORDS)