Fetal cardiac responding: a correlate of birth weight and neonatal behavior

Certain intrapartum fetal heart-rate (FHR) patterns are associated with low Apgar scores and other neonatal risks. Intrapartum FHR has been the subject of extensive clinical investigation, but only occasional reference is made to the possible behavioral correlates of this phenomenon. The current investigation found that neonates classified as FHR decelerators had lower birth weights and shorter gestational ages than FHR accelerators. Decelerators exhibited higher baseline heart rate and experienced more frequent uterine contractions than accelerators. Neurobehavioral assessment of these neonates indicated that decelerators had more abnormal reflex ratings and were less behaviorally organized than heart-rate accelerators. The results indicate that FHR responses are associated with prenatal growth, maturity, and possibly stress tolerance, and that intrapartum FHR responses be related to nonoptimal neonatal behavior.     

Maternal employment, work schedules, and children's body mass index

Previous work has shown that mothers' employment is associated with increases in children's body mass index (BMI), a measure of weight for height. Nonstandard work (working evenings or nights, weekends, or an irregular shift) may also be associated with children's BMI. This article examines the association between maternal work and children's BMI and considers the influence of mothers' nonstandard work schedules. Using data from school-age children (approximately 8 to 12 years) in the NICHD's Study of Early Child Care and Youth Development (N = 990), this study found that an increase in the total time a mother is employed is associated with an increase in her child's BMI; additionally, the association between maternal employment and children's weight is much stronger at 6th grade relative to younger ages. There was no evidence that maternal or home characteristics or children's time use mediated these associations, nor was there any evidence that nonstandard work was associated with children's BMI. Implications for policy and future research are discussed.     

Sleep and the body mass index and overweight status of children and adolescents

Associations between sleep and the body mass index (BMI) and overweight status of children and adolescents were estimated using longitudinal data from a nationally representative sample of 2,281 children aged 3–12 years at baseline. Controlling for baseline BMI, children who slept less, went to bed later, or got up earlier at the time of the first assessment had higher BMIs 5 years later and were more likely to be overweight. Child age moderated the relationship between bedtime and BMI. In addition, the study reports nationally representative data on the sleep habits of American children aged 3–18 years. This study underscores the likely importance of sleep on children's physical health and suggests that sleep is important for understanding childhood weight problems.     

Effects of acute shock on body weight are mediated by changes in food intake

We examined the causal role of decreased food intake in the body weight pattern observed after exposure to intermittent footshock. In Experiment 1, relative to controls, shocked animals decreased food intake and lost weight in the 24-h test. An unshocked group whose food intake was yoked to the shocked group (food-yoked group) for the poststress period revealed that food intake was a sufficient cause of the body weight loss. In Experiment 2, after the first 24 h, the shock group recovered food intake and body weight gain but did not compensate for the initial losses. Body weights of food-yoked animals again indicated that food intake was a sufficient cause of these effects. The lowered body weight of shocked animals at the end of testing was due to a transient hypoingestion and a failure to subsequently show a compensatory hyperingestion. Dess’s (1991) regulatory shift hypothesis is refined in the light of these findings.     

Effects of body mass index on the outcomes of in vitro fertilization in Chinese patients with polycystic ovary syndrome: a retrospective cohort study

Objective

To investigate the effects of body mass index (BMI) on the outcomes of in vitro fertilization (IVF) in Chinese patients with polycystic ovary syndrome (PCOS).

Methods

In the retrospective cohort study, a total of 1074 patients with PCOS undergoing IVF between April 2010 and May 2017 in two reproductive medicine centers, respectively in eastern China (Women’s Hospital, School of Medicine, Zhejiang University, Zhejiang Province) and in southern China (Maternal and Child Health Care Hospital of Liuzhou, Guangxi Province), were included. The patients were divided into four groups according to the recommended Chinese BMI cut-off points: underweight (BMI< 18.5 kg/m²), normal weight (18.5 kg/m²≤BMI<24.0 kg/m²), overweight (24.0 kg/m²≤BMI<28.0 kg/m²), and obese (BMI≥ 28.0 kg/m²). The basic characteristics of the PCOS patients, the details of IVF treatment, and the pregnancy outcomes were collected.

Main results

There were no significant differences among the normal weight, overweight, and obese PCOS patients undergoing IVF on the biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate, live birth rate, or term delivery rate (P>0.05), although the overweight and obese PCOS patients required more gonadotropin (Gn) (P<0.001) as well as longer stimulation period (P<0.001), and got less retrieved oocytes (P<0.05) and fertilized oocytes (P<0.05). The underweight PCOS patients required less Gn (P<0.05) and achieved higher live birth rate and term delivery rate (P<0.05), compared with the normal weight PCOS patients.

Conclusions

High BMI had no negative effects on the outcomes of IVF in Chinese patients with PCOS; however, the conclusion may seem a little limited due to the retrospective design and the potential bias.

     

Exposure to violence in childhood is associated with higher body mass index in adolescence

To determine whether different types of childhood adversity are associated with body mass index (BMI) in adolescence, we studied 147 adolescents aged 13–17 years, 41% of whom reported exposure to at least one adversity (maltreatment, abuse, peer victimization, or witness to community or domestic violence). We examined associations between adversity type and age- and sex-specific BMI z-scores using linear regression and overweight and obese status using logistic regression. We adjusted for potential socio-demographic, behavioral, and psychological confounders and tested for effect modification by gender. Adolescents with a history of sexual abuse, emotional abuse, or peer victimization did not have significantly different BMI z-scores than those without exposure (p > 0.05 for all comparisons). BMI z-scores were higher in adolescents who had experienced physical abuse (β = 0.50, 95% CI 0.12–0.91) or witnessed domestic violence (β = 0.85, 95% CI 0.30–1.40). Participants who witnessed domestic violence had almost 6 times the odds of being overweight or obese (95% CI: 1.09–30.7), even after adjustment for potential confounders. No gender-by-adversity interactions were found. Exposure to violence in childhood is associated with higher adolescent BMI. This finding highlights the importance of screening for violence in pediatric practice and providing obesity prevention counseling for youth.     

Schedule-induced wood-chewing in rats and its dependence on body weight

In Experiment 1, 12 rats were exposed to an FT 60 schedule of food reinforcement, followed either by extinction or by a massed-food control condition, in the presence of a wood block. In 9 rats, wood-chewing behavior increased systematically during the FT 60 condition and declined again during extinction or massed food, while the other 3 rats showed virtually no chewing behavior at any stage of the experiment. In Experiment 2, frequency and bout duration of wood-chewing under an FT 60 schedule of food reinforcement declined as body weight increased, in 7 rats. We conclude that wood-chewing qualifies as a schedule-induced behavior, and that it resembles schedule-induced drinking in its dependence on body weight. Unlike drinking, however, induced chewing occupied the middle region of the 60-sec interreinforcement interval, declined markedly within the session, and showed considerable within- and between-subject variability.     

Sociocultural and individual influences on muscle gain and weight loss strategies among adolescent boys and girls

The study examined the role of body dissatisfaction, body image importance, sociocultural influences (media and parent and peer encouragement), self‐esteem and negative affect on body change strategies to decrease weight and increase muscles in adolescent boys and girls. Surveys were administered to 587 boys and 598 girls aged between 11 and 15 years. For both genders, parent and peer encouragement and negative affect were the primary predictors of body dissatisfaction, body image importance and strategies to decrease weight and increase muscles. In addition, body image importance was a significant factor in the development of both types of body change strategies, while the media only predicted strategies to decrease weight. Lastly, the effects of self‐esteem were mediated by body dissatisfaction. For boys, a stronger focus on body importance occurred among the boys who were generally satisfied with their bodies while the reverse was the case for girls. © 2003 Wiley Periodicals, Inc. Psychol Schs 40: 209–224, 2003.     

建鲤苗种体长与体重关系数学模型的构建

利用建鲤实测体长和体重数据,应用统计分析方法进行体长一体重线性回归分析.结果表明:建鲤体长和体重之间呈曲线相关关系,其相关公式为:W=0.011L3.077(相关系数R=0.992 1),其中W为体重,L为体长.     

Effects of a prenatal care intervention for adolescent mothers on birth weight, repeat pregnancy, and educational outcomes at one year postpartum

About one-third of adolescent mothers receive inadequate prenatal care, and babies born to young mothers are more likely to be of low birth weight. The objective of this study is to evaluate a peer-centered prenatal care program for adolescent mothers. Pregnant adolescents were randomly assigned to an experimental or control group in a mastery modeling peer-support intervention designed to improve long- and short-term perinatal outcomes. A sample of 282 urban pregnant adolescents (94% African American, 4% Caucasian, 2% other) participated in the study. Participants were recruited from five clinics located mainly in Detroit, Michigan. Participants in the experimental group received care in a small group setting and learned to perform critical measurements with a peer partner during prenatal visits. Participants in the control group received individual prenatal care in the same clinics. Outcome measures included birth weight, years of schooling completed at one year postpartum, planned and unplanned pregnancy at one year postpartum, and employment and school attendance at one year postpartum. Mothers in the experimental group had a lower rate of low birth weight (6.6% vs. 12.5%, p=0.08). The rate of unplanned pregnancy was also lower for adolescents in the experimental group (13.4% vs. 15.9%), although this difference was not statistically significant. Adolescents who participated in the intervention were more likely to have continued their education during the pregnancy and the postpartum year. The mastery modeling, peer-centered, prenatal care program produced some positive pregnancy outcomes for adolescent mothers.     

Effects of weight on children's educational achievement

In this paper, we investigate the association between weight and children's educational achievement, as measured by scores on Peabody Individual Achievement Tests in math and reading, and grade attainment. Data for the study came from the 1979 cohort of the National Longitudinal Survey of Youth (NLSY), which contains a large, national sample of children between the ages of 5 and 12 between 1986 and 2004. We obtained estimates of the association between weight and achievement using several regression model specifications that controlled for a variety of observed characteristics of the child and his or her mother, and time-invariant characteristics of the child. Our results suggest that, in general, children who are overweight or obese have achievement test scores that are about the same as children with average weight.     

Factors underlying the association of body mass index with serum ALT in Chinese hypertensive adults without known hepatic diseases

Objective:High body mass index (BMI) is considered as the most important risk factor for elevated serum alanine aminotransferase (ALT) concentration. This study examined an array of factors, including waist circumference (WC) and folate deficiency, which may mediate the association of BMI with serum ALT concentration in Chinese hypertensive adults without known hepatic diseases. Methods:A multicenter, cross-sectional study was carried out. A total of 378 patients with mild or moderate hypertension and without known hepatic diseases were recruited from five hospitals in Harbin, Shanghai, Beijing, Xi’an, and Nanjing. Results:Of the 360 hypertensive patients with complete data in our final analysis, 13.6% had high ALT concentrations (>40 IU/L). Factors including BMI, WC, triglyceride level, and folate concentration were associated with ALT concentration in univariate analysis. Consistently higher prevalence rates of elevated ALT were observed in subjects with lower folate concentrations (≥12 vs. <12 nmol/L, 9.9% vs. 17.8%, P=0.03), with higher BMI (≥28 vs. <28 kg/m2, 21.5% vs. 11.4%, P=0.02) or higher WC (≥90 vs. <90 cm, 18.5% vs. 10.0%, P=0.02). However, in multivariate analysis, the association between BMI and ALT concentration disappeared (P=0.802 in males and 0.369 in females), while WC in females (P<0.001) and folate concentration (P=0.036 in males and 0.044 in females) remained as significant predictors for ALT concentration. Conclusions:This multicenter study demonstrated that WC and low folate concentration were important factors underlying the association between BMI and ALT concentrations in Chinese hypertensive adults without known hepatic diseases.     

基于样本权重的数字资源评价指标体系研究

本文通过分析当前数字资源评估的常用方法和一般过程,给出基于样本权重的数字资源评价指标体系构建方法,并根据层次分析法和功效系数法两种不同的评估统计模型,对同一数字资源的指标体系,给出了单一指标以及总体的定量评价。     

Concurrent schedule responding as a function of body weight

Five pigeons pecked for food reinforcement on several concurrent schedules. Their body weights were varied from 80% to 110% of their free-feeding weights. A number of predictions of the equations proposed by Herrnstein (1970) were tested. As predicted, the relative rate of responding equalled the relative rate of reinforcement for all subjects, on all schedules, at all body weights. And, as predicted, the overall rates of responding on the components of a concurrent schedule were slower than the local rates of responding on the components of an identical multiple schedule. Contrary to prediction, the total rate of responding generated by the concurrent schedules did not increase with increases in the total rate of reinforcement they provided. And, contrary to prediction, the k parameter did not remain constant, and the R₀ parameter did not increase with increases in body weight. It was concluded that Herrnstein’s matching law and his interpretation of the m parameter are correct but that the interpretations of k and R₀ require further investigation.     

草药牛蒡子对运动大鼠体重及力竭时间的影响

牛蒡子为常用中药在医药,食品业中的应用十分广泛.目前国内外对牛蒡子与运动关系的研究少见报道,所以我们建立运动动物模型,研究目的在于探计补充牛蒡子对运动大鼠运动能力和防御体系的影响,为将其用于运动员的食品中提供参考.     

The relations among body image, physical attractiveness, and body mass in adolescence

Body dissatisfaction, a measure of body image, physical attractiveness, and body mass index were assessed in the same 115 participants at ages 13, 15, and 18 years. Sex differences in body dissatisfaction emerged between 13 and 15 years of age and were maintained at 18. Over adolescence, girls increased, while boys decreased, their body dissatisfaction. Body dissatisfaction was weakly related to others' ratings of the adolescents' physical attractiveness and their body mass index. The results support the idea that, overall, adolescents' body image has little to do with how others perceive them, but once developed remains constant through much of adolescence.     

基于AHP的高校多媒体教学有效性指标的权重确定

多媒体教学有效性指标权重赋值关乎多媒体教学有效性的评价。通过问卷调查和统计获得多媒体教学有效性指标的权重,然后在此基础上运用层次分析法计算出多媒体教学有效性指标的最终权重,经检验具有相当的一致性,在实践中为评价多媒体教学有效性提供一种科学手段。