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A 6-month feeding trial was conducted to compare the effects of extruded pellet (EP) andmoist pellet (MP) feed on the growth performance, non-specific immunity, and intestinal microbiota of olive flounder. A total of 60,000 fish with an average weight of 70.8 ± 6.4 g were divided into two groups and fed with one of two experimental diets. At the end of a 6-month feeding trial, the weight gain and specific growth rate of the fish fed with the MP diets were significantly higher than those of fish fed with EP (P < 0.05). However, the EP group exhibited a lower feed conversion rate than the MP group, meaning that the EP diet was more cost-effective. Whole-body proximate compositions and non-specific immune responses (superoxide dismutase, myeloperoxidase, and lysozyme activity) were not significantly different between the two groups. There were no significant differences in the α-diversity of the intestinal bacterial community of the two groups. However, the composition of microorganisms at the phylum to genus level was different between the groups. The EP group was rich in Actinobacteria, Corynebacterium, Bacillus, and Lactobacillus, whereas the MP group was dominated by Proteobacteria, Vibrio, and Edwardsiella. Collectively, the MP diet increased growth performance and pathogen concentration in the gut; whereas EP improved feed conversion and beneficial Bacillus and Lactobacillus proportion in the intestinal microbial community. [ABSTRACT FROM AUTHOR]

This study examines the differences in effects of private tutoring and parenting behaviors on children's academic achievement between low- and high-income groups in Korea, using data from the Korean Welfare Panel Study. The results show that parenting behaviors have a significant positive effect on academic achievement for both income groups. However, we find different patterns of private tutoring across income groups. Private tutoring expenditures have a significant positive effect on academic achievement for the low-income group, but only a marginal effect for the high-income group. The findings imply that the value of financial investment in private tutoring is somewhat doubtful, especially for high-income groups. However, the results indicate that parenting behaviors are more important for children's academic achievement. Our results show that the effect of parenting behaviors on children's academic achievement is greater than that of private tutoring expenditures. [ABSTRACT FROM AUTHOR]