Eficacia académica percibida, crianza, uso de internet y comportamiento en la adolescencia / Achievement perceived, parenting, internet use and adolescent behavior

Resumen El uso intensivo de internet puede contribuir a desarrollar disfunciones psicosociales graves en la adolescencia. El objetivo de esta investigación es analizar las relaciones de la percepción de eficacia académica con el uso de internet para ocio, los estilos de crianza y los problemas exteriorizados e interiorizados en la adolescencia (agresividad proactiva, reactiva, física y verbal, afiliación a pares rebeldes e inestabilidad emocional). Han participado 762 adolescentes de 12 a 17 años (M = 13.69; DT = 1.40; varones 52.8%). Utilizan internet en tiempo de ocio entre cero y 98 horas semanales, de ahí que la población se haya distribuido en cuartiles. Las variables se han obtenido a través de pruebas estandarizadas. Los análisis estadísticos se basan en metodología descriptiva y predictiva. Los resultados han permitido obtener tres conclusiones. Primera, el número de horas de internet para fines recreativos se relaciona con una peor eficacia académica percibida. Segunda, los adolescentes que usan Internet intensamente perciben más permisividad de los padres y menos apoyo y comunicación por parte de los padres. Estos adolescentes presentan más riesgo de conectarse con pares rebeldes y tienen índices más altos de inestabilidad emocional y agresividad (reactiva, proactiva, física y verbal). Tercera, la paternidad más punitiva, la agresividad y la afiliación a pares rebeldes aumentan el uso intensivo de Internet. Esta investigación corrobora la necesidad de una formación adecuada, dirigida a fomentar el apoyo y la comunicación paterno-filial para educar el uso racional y responsable de internet de ambos, padres y adolescentes.

Abstract The intensive use of the Internet can contribute to the development of serious psychosocial dysfunctions in adolescents. The purpose of this research is to analyze the relationships between achievement perceived with the leisure use of the internet, parenting, and externalized and internalized problems during adolescence (aggressiveness reactive, proactive, physical and verbal, affiliation with deviant peers and emotional instability). The sample is made of 762 adolescents from 12 to 17 years old (M = 13.69, SD = 1.40), with 52.8% of males and 47.2% of females. The use of internet in leisure time is between 0-98 hours per week. Hence the population has been distributed in quartiles. The variables have been obtained through standardized tests. Statistical analyzes are descriptive and predictive methodology. The analyses carried out have allowed us to obtain three conclusions. First, the number of hours of internet for recreational purposes is related to worse achievement perceived of the adolescent. Second, it has been found that adolescents who use Internet intensively greater perceived permissiveness of the parents and a lower support and communication with them. These adolescents present an increased risk of joining deviant peers and have higher rates of emotional instability and aggressiveness (reactive, proactive, and physical and verbal). Third, more punitive parenting, aggressiveness and affiliation with deviant peers boost the intensive use of the internet. This empirical research corroborates the need for adequate training aimed at fostering parental-child support and communication to educate the rational and responsible use of the Internet by both parents and adolescents.

Heat identification by 17beta-estradiol and progesterone quantification in individual raw milk samples by enzyme immunoassay

Background: There is a substantial decline in first-service-pregnancy-rate in dairy cows. In this regard, future prospects are to measure milk hormones on-farm and progesterone levels in milk are not enough to precise ovulation unless connected to other data. The objectives of this study were to investigate whether 17beta-estradiol could be measured from individual cow milk samples using a commercially available non-radiolabelled enzyme immunoassay kit (EIA) with no previously reported milk application, and whether those detections could precisely illustrate 17beta-estradiol pre-ovulation peak in spite of its limited concentration and short manifestation in milk. Results: Milk sample treatments for progesterone and 17beta-estradiol EIA measurements are described. Hormonal profiles from daily milk samples of six different cows were reported and 17beta-estradiol pre-ovulation peak was visualized in all cases. Heat detection was possible by EIA using one every 2 days milking samples in almost all studied cases. Only in one case, morning and afternoon milking samples were required to visualize the 17beta-estradiol pre-ovulation peak. Conclusions: 17beta-estradiol EIA quantification in raw milk is a reliable, rapid, economic and a precise method to describe cow heat along with EIA progesterone determination.