Why are migrant students better off in certain types of educational systems or schools than in others?

The main research question of this paper is the combined estimation of the effects of educational systems, school composition, track level, and country of origin on the educational achievement of 15-year-old migrant students. We focus specifically on the effects of socioeconomic and ethnic background on achievement scores and the extent to which these effects are affected by characteristics of the school, track, or educational system in which these students are enrolled. In doing so, we examine the ‘sorting’ mechanisms of schools and tracks in highly stratified, moderately stratified, and comprehensive education systems. We use data from the 2006 Programme for International Student Assessment (PISA) wave. Compared with previous research in this area, the paper’s main contribution is that we explicitly include the tracks-within-school level as a separate unit of analyses, which leads to less biased results concerning the effects of educational system characteristics. The results highlight the importance of including factors of track level and school composition in the debate surrounding educational inequality of opportunity for students in different education contexts. The findings clearly indicate that the effects of educational system characteristics are flawed if the analysis only uses a country- and a student level and ignores the tracks-within-school level characteristics. From a policy perspective, the most important finding is that educational systems are neither uniformly ‘good’ nor ‘bad’, but they can result in different consequences for different migrant groups. Some migrant groups are better off in comprehensive systems, while others are better off in moderately stratified systems

The effect of dietary zinc level and source on yearling bull growth and fertility

To study the effect of dietary zinc level and source on bull growth and fertility, 325 yearling Angus bulls were allotted by weight into six pens (three pens of heavy and three pens of lightweight bulls). The three supplemental zinc (Zn) treatments were 1) 40 ppm inorganic Zn all supplied by Zn sulfate (ZnI); 2) 40 ppm Zn with 1/3 supplied by Zn proteinate and 2/3 supplied by Zn sulfate (ZnPI); and 3) 60 ppm ZnI all supplied by Zn sulfate (ZnHi). Initial and final liver biopsies (10 per pen) were collected and analyzed for zinc concentration. Individual weights and scrotal circumferences also were recorded at the start and conclusion of the trial. Bull s intended for public sale (n=167) had their semen collected and evaluated for motility and morphological abnormalities. Bulls with percent normal sperm cell counts of less than 70% or with motility scores less than fair (motility scores = poor, fair, good, very good) were considered classification deferred (CD). Following 126 days of treatment, ZnHi bulls had a greater (P=.058) percent change in liver Zn concentration than ZnI, but similar increases to ZnPI. No difference s in bull ADG or percent change in scrotal circumference were detected. ZnPI and ZnHi bulls had a higher (P<.05) percent of normal sperm cells than ZnI bulls. ZnPI and ZnHi treatments had fewer (P<.05) CD bulls than ZnI. In all fertility measures observed , bulls receiving the Zn proteinate/Zn sulfate combination at 40 ppm had improved semen quality when compared to bulls supplemented with 40 ppm Zn sulfate

Parental choice and education policy

SIGLEAvailable from British Library Document Supply Centre-DSC:3120.2475(12) / BLDSC - British Library Document Supply CentreGBUnited Kingdo