Spin-dependent correlations and the semi-exclusive ^{16}O(e,e'p) reaction

The effect of central, tensor and spin-isospin nucleon-nucleon correlations upon semi-exclusive ^{16}O(e,e'p) reactions is studied for Q^2 and Bjorken x values in the range $0.2 \lesssim Q^2 \lesssim 1.1 (GeV/c)^2$ and 0.15 $\lesssim$ x $\lesssim$ 2. The fully unfactorized calculations are performed in a framework that accounts not only for the dynamical coupling of virtual photons to correlated nucleon pairs but also for meson-exchange and $\Delta_{33}$-isobar currents. Tensor correlations are observed to produce substantially larger amounts of semi-exclusive ^{16}O(e,e'p) strength than central correlations do and are predominantly manifest in the proton-neutron knockout channel. With the exception of the $x \approx 2$ case, in all kinematical situations studied the meson-exchange and isobar currents are a strong source of A(e,e'p) strength at deep missing energies. This feature gives the A(e,e'p) strength at deep missing energies a pronounced transverse character.Comment: 14 pages, 6 figure

The role of alcohol specific socialization in adolescents’ drinking behavior.

ABSTRACT Aims To determine which alcohol-specific socialization practices are related to adolescents' alcohol use, and to investigate whether parents differ in their alcohol-specific socialization towards their children. Design In a sample of 428 families, both parents and two adolescents (aged 13-16 years) completed a questionnaire at home about alcohol-specific parenting and their own alcohol use. Based on the reports of each family member, three different models of alcohol-specific socialization were formulated: from the perspective of the siblings, the mother and the father. Findings Results of structural equation modelling generally showed the same associations between alcohol-specific socialization and drinking of younger and older adolescents. The strongest association was found for providing alcoholspecific rules. Applying strict rules about alcohol use was negatively related to adolescents' alcohol use; this was also the case for having confidence in the effectiveness of alcohol-specific socialization. Unexpectedly, frequency of communication about alcohol issues was positively associated with alcohol consumption of adolescents. Conclusions This study is one of the first to examine associations between alcohol-specific socialization and adolescents' drinking using a between-and a within-family design. Results showed strong associations between alcoholspecific socialization (particularly of enforcing rules) and adolescent alcohol use. Although parents strongly differentiated their socialization practices between children, no differences in associations between alcohol-specific socialization and drinking were found between older and younger adolescents

Reading literacy intervention with fifth graders in Lima

Se estudian los efectos del programa Lectura sobre la comprensión de lectura y motivación para leer en niños de quinto grado de los niveles socioeconómicos medio y bajo de Lima. El programa enfatizó las estrategias para leer y las dimensiones de motivación para leer. Mediante el análisis de varianza se calcularon los efectos de tiempo de medición, grupo, nivel socioeconómico y género sobre la comprensión de lectura y la motivación para leer. Los resultados mostraron que el nivel de comprensión de lectura se incrementó más en el grupo de intervención. Los alumnos del nivel socioeconómico bajo se beneficiaron más del programa que los niños del nivel socioeconómico medio. El programa también tuvo un efecto significativo sobre la motivación para leer

Reading literacy intervention with fifth graders in Lima

This study examined the effects of the reading comprehension program <em>Lectura </em>for fifth graders of middle-class and low-class social economic backgrounds in Lima (Peru) on read­ing literacy and reading motivation. The intervention emphasized reading strategies and dimensions of reading motivation. ANOVA was used in order to calculate the effects of measurement point, group, social economic status and gender on reading comprehension and reading motivation. Results showed that reading literacy increased more in the interven­tion group than in the control group. Children from the low social economic background benefited more from the intervention than children with a middle social economic back­ground. The program had also a significant impact on children’s reading motivation