Amounts served and consumed of school lunch differed by gender in Japanese elementary schools

School lunches serve to improve nutritional status and to promote the health of children. The purpose of this study was to investigate the portion sizes of school lunches served and consumed in Japanese elementary schools. In addition, gender difference in servings and consumption were also studied. A cross-sectional study was undertaken between October 2007 and February 2008 in schools located in Tokyo and Okayama, Japan. A total of 192 fifth-grade children attending four elementary schools participated in this study. Weighed plate waste methods and observation were used to collect dietary data for two non-consecutive days. The proportion of children who chose staple foods along with main dishes and/or side dishes for at least one day was higher in boys than in girls (respectively, for staple food: 42.1% vs. 9.3%, for main dish and/or side dish: 68.4% vs. 44.3%, P < 0.001). The ratio of initial amount served to amount offered was 0.88 ± 0.11 for boys and 0.84 ± 0.10 for girls (P < 0.05). The ratio of amount consumed to amount offered was 1.04 ± 0.19 for boys and 0.88 ± 0.12 for girls (P < 0.001). Weight was related to amount consumed both in boys (r = 0.222, P < 0.05) and in girls (r = 0.201, P < 0.05). These findings suggest that the nutritional standards of school lunch programs should take into account gender differences. Clearly, boys were more likely to consume more than the initial amounts served due to their higher propensity to take second helpings. Boys feel few reservations about taking second helpings to adjust their total intake. However, school lunch plans should take into consideration girls' reluctance to do so, by serving appropriate initial portion sizes

A High-Speed Congenic Strategy Using First-Wave Male Germ Cells

BACKGROUND: In laboratory mice and rats, congenic breeding is essential for analyzing the genes of interest on specific genetic backgrounds and for analyzing quantitative trait loci. However, in theory it takes about 3-4 years to achieve a strain carrying about 99% of the recipient genome at the tenth backcrossing (N10). Even with marker-assisted selection, the so-called 'speed congenic strategy', it takes more than a year at N4 or N5. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe a new high-speed congenic system using round spermatids retrieved from immature males (22-25 days of age). We applied the technique to three genetically modified strains of mice: transgenic (TG), knockin (KI) and N-ethyl-N-nitrosourea (ENU)-induced mutants. The donor mice had mixed genetic backgrounds of C57BL/6 (B6):DBA/2 or B6:129 strains. At each generation, males used for backcrossing were selected based on polymorphic marker analysis and their round spermatids were injected into B6 strain oocytes. Backcrossing was repeated until N4 or N5. For the TG and ENU-mutant strains, the N5 generation was achieved on days 188 and 190 and the proportion of B6-homozygous loci was 100% (74 markers) and 97.7% (172/176 markers), respectively. For the KI strain, N4 was achieved on day 151, all the 86 markers being B6-homozygous as early as on day 106 at N3. The carrier males at the final generation were all fertile and propagated the modified genes. Thus, three congenic strains were established through rapid generation turnover between 41 and 44 days. CONCLUSIONS/SIGNIFICANCE: This new high-speed breeding strategy enables us to produce congenic strains within about half a year. It should provide the fastest protocol for precise definition of the phenotypic effects of genes of interest on desired genetic backgrounds

ショウニ ヒマン ハッショウ シンテン ニ ジリツ シンケイ ガ ハタス ヤクワリ

京都大学0048新制・課程博士博士(人間・環境学)甲第10940号人博第227号15||182(吉田南総合図書館)新制||人||57(附属図書館)UT51-2004-G787京都大学大学院人間・環境学研究科文化・地域環境学専攻(主査)教授 森谷 敏夫, 教授 津田 謹輔, 助教授 小田 伸午学位規則第4条第1項該当Doctor of Human and Environmental StudiesKyoto UniversityDA