Linearized Growth Curve,Proper Age and Age at Menarche

A mathematical model of the linearized growth curve and its physiological interpretation by the introduction of proper age, which is proportional to the chronological age, are presented here. In the second phase, but not in the first phase, this constant of proportionality is highly correlated with the age at menarche.     

Race Differences in Accuracy of Self‐Reported Childhood Body Size Among White and Black Women

Objective: To assess the relation of self‐reported current and recalled preadolescent body size to measured BMI (kilograms per meter squared) and interviewer's assessment of body size. Research Methods and Procedures: This was a prospective cohort study of 1890 white and black women who were 9 to 10 years old at time of enrollment and were followed up 10 to 13 years later. At baseline, subjects had their weight and height measured and were asked to indicate their current body size from a series of nine pictograms. A sample of the subjects also had their body size evaluated by interviewers. At the young‐adult follow‐up visit, subjects were asked to recall their body size at 9 and 10 years old and to indicate their current weight, height, body size, and level of concern with weight. Results: Among the women with interviewer assessments, 84% of the white women and 67% of black women recalled a body size that was within one body size of the interviewer's assessment. Independent of weight status in childhood or at follow‐up, black women were 3 times more likely than white women to recall a body figure that was more than one figure leaner than the shape they reported at baseline (odds ratio = 3.5, 95% confidence interval 2.8 to 4.5) or than the interviewer's rating at baseline (odds ratio = 3.4, 95% confidence interval 2.4 to 4.9). Discussion: The results suggest that the use of body figures to recall childhood size are best suited for ranking subjects in terms of BMI. The higher rate of underestimation of size by black women suggests that body figure ratings work best for white women.     

The “Good Enough” Body Size as Judged by People of Varying Age and Weight

Objective: To examine the concept of the “good enough” body size acceptability across a wide range of ages and weight status. Research Methods and Procedures: Subjects were 303 children, 427 adolescents, 261 young adults, and 326 middle‐age adults who selected acceptable body sizes from an array of drawings representing their own age and gender. They also selected body sizes representing their own actual and ideal size. Results: A large majority (87%) of subjects considered their own body size socially acceptable. This finding applied to both genders in all age groups and to underweight, normal weight, and overweight subjects. Even among obese subjects, 48% considered their own body size socially acceptable. For the large percentage of subjects who reported a discrepancy between their actual and ideal body sizes, most considered their own body size acceptable. This finding also applied to both genders in all age groups and to underweight, normal weight, and overweight subjects. Discussion: Most male and female subjects across a wide range of ages and status considered their own body size to be within the range of socially acceptable body sizes even though, for many, it did not match their ideal. The implications of expanding body size research to include the conceptual framework of body size acceptability is discussed in terms of contributing to a paradigm of positive psychology.     

A Comparison of Body Size Evaluations of Obesity Surgery Patients and General Population Adults

RAND, COLLEEN S. W., JAQUELYN LISS RESNIK, AND ALEX M. C. MACGREGOR. A comparison of body size evaluations of obesity surgery patients and general population adults. Obes Res. Objective: To compare post-operative obesity surgery patients and general population adults in their assessments of a wide range of body sizes. Research Methods and Procedures: Obesity surgery patients (n = 274) and general population adults (n = 326) rated ideal and socially acceptable body sizes in separate arrays of babies, children, young adults, and middle-aged and older adults. Nine line figure drawings ranging from very thin to very obese were rated for each array. Results: Both groups selected the same ideal body size for all arrays except for babies. Both groups rejected obese and very thin body sizes as socially acceptable. However, the obesity surgery patients were more restrictive than general population adults in their ratings of socially acceptable body sizes. Current obesity status did not impact ratings for the patient or general population subjects. In the patient sample, time since surgery did not influence body size evaluations. Discussion: The study of body size ratings limited only to the “ideal” size may be misleading because it may mask subtle but meaningful differences between groups. The consistent difference in more restrictive ratings of obesity surgery patients compared to general population adults may be due to patients' greater psychological investment in endorsing the societal ideal body size. It may also be due to patients' status as peripheral group members of the normal weight community. The inability of some patients to maintain their post-operative weight loss may be particularly problematic for those who have defined “socially acceptable” body size most narrowly.     

A First Look at Estimating Body Size in Dentally Conservative Marsupials

The relationship between body size and tooth size has been documented for recent primates and insectivores and resulting predictive equations used to estimate body size in fossil species. This relationship is an important one, as body size is related to a host of physiological and ecological factors. In this study, the relationship between body size and molar size in recent dentally conservative marsupials is examined and body size in Cretaceous marsupials is estimated. Body weight information and basic length, width, and area measurements were taken from the molars of individuals from 22 species of Didelphidae and Dasyuridae. Least squares regression analysis shows that, as in previous studies on eutherians, the first molar is generally the most highly correlated with body size. In fact, there is a strong relationship between body size and tooth size throughout the molar series, suggesting that a fairly accurate body size estimate could be obtained from molars other than the first molar. The inclusion of species that are morphologically divergent from the average morphotype may affect the analysis. Body mass estimated in Cretaceous marsupials indicates a range of sizes similar to that seen in Recent dentally primitive marsupials.     

体重、年龄和应激刺激对菲牛蛭繁殖性能的影响

采用单因素方差分析等方法探讨人工养殖条件下体重、年龄和环境应激对菲牛蛭繁殖性能的影响。结果表明,体重对卵茧大小和湿质量及幼蛭体长、体宽和湿体质量无显著影响(P>0.05),而亲蛭性腺系数、平均产茧数、孵化率和平均孵化数在各组间差异显著(P<0.05),其中体重10～15g组明显高于其他组(P<0.05);年龄对亲蛭平均产茧数、孵化率、平均孵化数和卵茧大小影响显著(P<0.05),其中2～3年龄亲本具有最高的平均产茧数、孵化率和平均孵化数,8月龄亲本所产卵茧个体明显大于其他年龄组(P<0.05),而卵茧湿质量及幼蛭体长、体宽和湿体质量在各年龄组间均无显著差异(P>0.05)。环境应激对亲蛭的平均产茧数、孵化率和平均孵化数影响显著(P<0.01),其中1～2次操作应激下的平均产茧数和孵化数最高,无操作刺激下的孵化率略高于1～2次操作刺激(P>0.05),而卵茧大小和湿质量及幼蛭体长、体宽和湿体质量在各应激处理组间无显著差异(P>0.05)。本研究获得了菲牛蛭繁殖的最佳体重和年龄,建议繁育生产中挑选10～15g和2～3年龄的个体作为亲本,期间进行1～2次操作刺激可提高其繁殖性能。     

Age at menarche: the influence of environmental conditions

Age at menarche was studied by the recollection method in two groups of Causasian Jewish high school girls, inhabitants of two towns in Israel, Safad and Elat. The two towns differ mainly in climatic conditions. The age at menarche was found to be significantly lower (P<0.02) in the hot town of Elat than in the temperate town of Safad: 13.30±1.21 and 13.58±0.9 years, respectively (mean ±SD). A significant association was found between the age at menarche and the town in which the girls lived. Accordingly, in the hot town of Elat, the percentage of girls who had their first menstrual cycle by the age of 12 years and earlier, was more than double that of the girls in Safad (17.9% and 7.1%, respectively). It is concluded that the environmental temperature, with or without any possible interaction of humidity, is probably responsible for the tendency for an earlier onset of menarche in girls living in the hot town of Elat.     

不同生境间龟鳖类体型的差异

体型是动物重要的形态特征,影响动物的生境利用。为揭示龟鳖类体型与生境之间的关系,通过文献收集331种龟鳖(龟鳖目Tesudines总物种数的98.8%)的最大背甲长及其生境信息,将生境分为海洋、淡水、岛屿性陆地和大陆性陆地4种类型,再将淡水生境分为大静水、大流水、小静水、小流水和所有水域5种亚类型,大陆性陆地生境分为高地、平地和荒漠3种亚类型,从而比较不同生境类型或亚类型之间龟鳖类体型的差异。广义线性混合模型分析结果显示:1)海龟体型最大,岛屿性陆龟次之,淡水龟鳖和大陆性陆龟体型最小,且后两者差异无统计学意义。2)淡水龟鳖类的体型在5种亚类型生境间存在差异,大静水和大流水水域的体型均显著大于小静水和小流水水域,而体型在大静水与大流水水域、小静水与小流水水域之间的差异均无统计学意义,表明淡水龟鳖类体型与水域面积有关,而与水域是静水或流水无关。广布所有水域的淡水龟鳖类体型趋于中间型,且与其他4种亚类型生境中的体型之间的差异均无统计学意义。3)大陆性陆龟的体型从高地到平地再到荒漠有逐渐变大的趋势,但差异无统计学意义。本研究揭示龟鳖类的保护对策需要考虑其体型和生境面积的相关性。     

Biracial Differences in Physical Activity and Body Composition Among Women

Overweight among black females is almost two times as frequent as among white females. Genetics, caloric intake, and physical activity have been identified as possible explanatory factors. This study assessed the differences in physical activity and body composition in 76 white and 66 black adult females. Black women had significantly higher (p=.0001) percent body fat (32.2 ± 7.1) than white women (27.7 ± 6.5) with a similar difference in weight (4.4 kg) approaching significance (p=.055). Physical activity was assessed using a structured 24-hour recall instrument. A purposive sampling design was implemented to control for age, education and occupation. A summary physical activity value unit for the 24-hour period revealed a significantly greater mean value for white females (41.93 + 4.7) than for black females (40.01 ± 3.9) suggesting white females were more physically active (p=.02) although this was not a function of biracial differences in play/recreation and exercise/sport type of activities. Although both black and white females were found to be sedentary (MET value ± 2) over 90 percent of the time, black women were significantly more sedentary (p=.03). Biracial differences in discretionary non-exercise oriented activities may contribute to different rates of overweight observed between black and white women.     

Body Size and Reproductive Tactics in Varanid lizards

Body size and female reproduction in the water adult females larger than 500 mm SVL and 32 adult males Ledong, Hainan under permit to our laboratory in Hainan monitor lizard （Varanus salvator） were studied. Forty-two larger than 400 mm SVL were donated by local people in in 2013 and 2014. The largest male and female measured 745 and 755 mm SVL, respectively. The mean SVL was greater in adult females than in adult males. Males had larger heads （head width） than females of the same SVL. The smallest reproductive female in our sample was 565 mm SVL. Females produced a single clutch of 17.1 （10-23） pliable-shelled eggs per breeding season stretching from mid-June and mid-September. Clutch size and clutch mass were all positively related to female SVL. However, there was no significant linear relationship between egg mass and female SVL. Larger females generally produced more eggs, and thus heavier clutches than did smaller ones. There was no significant linear relationship between relative clutch mass and female SVL. Phylogenetic generalized least squares （PGLS） analysis, accounting for phylogenetic relationships, showed that clutch size was positively correlated with mean maternal SVL in varanid lizards. PGLS analysis showed that phylogenetic relationships did not affect clutch （or/and egg） mass and the SVL although there were significant linear relationship between clutch （or/and egg） mass and mean maternal SVL. Therefore, we could draw some general conclusions about the body size and reproductive tactics in varanid lizards that larger females generally produced more eggs, larger eggs and thus heavier clutches than did smaller ones.     

Reference Growth Curves for Cypriot Children 6 to 17 Years of Age

Objective: The purpose of the study was to present smoothed percentiles for body weight and height, waist circumference, and body mass index (BMI) in Cypriot children and to compare their BMI 85th and 95th percentiles with those of children in other countries. Research Methods and Procedures: The study was a cross‐sectional study, including a representative sample of 2472 healthy children (49.1% boys) in Cyprus ages 6 to 17 years, who were evaluated during the 1999–2000 school year. Body weight and height and waist circumference were measured using standard procedures. BMI was calculated as weight in kilograms per height in square meters. Smoothed, sex‐specific percentiles for these variables were calculated using polynomial regression models. Crude weight, height, waist, and BMI percentile values are presented in sex‐specific tables and smoothed percentile curves are presented in charts. The 85th and 95th percentiles for BMI were compared with measurements from other countries, because of the concern of the upper limits of BMI in respect to the evaluation of obesity. Results: The 85th and 95th BMI percentile values are higher in Cypriot boys than in Swedish and Iranian boys through all ages and in girls ages 6 to 15 years, whereas after the age of 15 years, both Swedish and Iranian girls’ percentiles are equalized with their Cypriot peers. Discussion: Weight, height, waist circumference, and BMI values and charts are presented for the first time for Cypriot children and adolescents. Much concern should be addressed to the observation that for the majority of the Cypriot sample, the upper BMI limits are higher than the peers of developing and developed countries.     

棘胸蛙求偶鸣声与温度有关但与体大小无关

鸣声被认为是鉴别蛙类物种最有效的特征之一,但受许多因素影响。为了研究环境因素和身体大小与雄性棘胸蛙鸣声特征的关系,在人工仿生态养殖条件下测量环境温度和体温以及蛙体的大小(体重、体长),并通过个体定位,录制繁殖期中雄性棘胸蛙的求偶鸣声,分析鸣叫参数。结果表明,棘胸蛙雄性鸣声特征测量参数与体重、体长无相关性,而鸣声特征中的鸣叫时长、音节时长与环境温度、水温、体温、泄殖腔温度存在负相关性。研究结果提示在开展棘胸蛙鸣声学研究时应注意温度对其的影响。     

Realistic Weight Perception and Body Size Assessment in a Racially Diverse Community Sample of Dieters

Recently, a shift in obesity treatment away from emphasizing ideal weight loss goals to establishing realistic weight loss goals has been proposed; yet, what constitutes “realistic” weight loss for different populations is not clear. This study examined notions of realistic shape and weight as well as body size assessment in a large community-based sample of African-American, Asian, Hispanic, and white men and women. Participants were 1893 survey respondents who were all dieters and primarily overweight. Groups were compared on various variables of body image assessment using silhouette ratings. No significant race differences were found in silhouette ratings, nor in perceptions of realistic shape or reasonable weight loss. Realistic shape and weight ratings by both women and men were smaller than current shape and weight but larger than ideal shape and weight ratings. Compared with male dieters, female dieters considered greater weight loss to be realistic. Implications of the findings for the treatment of obesity are discussed.     

Birth Weight and Its Relationship to Size Attained and Relative Fat Distribution at 7 to 12 Years of Age

The relationship between birth weight and relative subcutaneous fat distribution at school age was considered in 131 boys and 106 girls 7 to 12 years of age. Relative fat distribution at school age was estimated with the ratio of the subscapular to triceps skinfolds (S/T) for the total sample, and with the ratio of the sum of two trunk (subscapular, midaxillary) to the sum of two extremity (triceps, medial calf) skinfolds (T/E) for subsamples of 102 boys and 63 girls. There were no sex differences in the S/T ratio (mm/mm), boys 0.62 ± 0.15, girls 0.63 ± 0.18; T/E ratio (mm/mm), boys 0.58 ± 0.13, girls 0.59 ± 0.16; and BMI (kg/m²), boys 17.1 ± 2.4, girls 16.9 ± 2.2. Second order partial correlations, controlling for age and the BMI or age and sum of skinfolds, between birth weight and the skinfold ratios are, respectively, ?0.22 and ?0.20 (p<0.01) for S/T and ?0.29 and ?032 (p<0.01) for T/E in girls, and ?0.18 and ?0.17 (p<0.05) for S/T and ?0.06 and ?0.6 for T/E in boys. Though low, the correlations suggest that as birth weight decreases proportionally more subcutaneous fat is accumulated on the trunk than on the extremities, more so in females than in males. Results of stepwise multiple regression analyses indicate that birth weight accounts for from 2% to 8% of the variance in relative subcutaneous fat distribution at school age.     

FecB基因在9个绵羊品种中的多态性及其与产羔数和羔羊生长发育的相关性

以绵羊BMPR-IB基因为候选基因,应用PCR-RFLP方法通过分析湖羊、夏洛来、陶赛特、萨福克、罗米丽、中国美利奴羊、中国美利奴肉用多胎品系以及陶赛特×中国美利奴羊和萨福克×中国美利奴羊杂交后代共615只个体的FecB基因多态性,以及BMPR-IB基因多态性对产羔数、体尺和体重的影响.结果表明,BMPR-IB基因在不同品种(系)绵羊中共有3种基因型(BB、B+和++),但基因型频率分布在各品种(系)间差异极显著(P<0.01).在湖羊中仅有BB基因型;在中国美利奴肉用多胎品系中BB、B+和++基因型频率分别为51%、30%和19%;而其他品种(系)羊中则仅有++基因型.对中国美利奴羊肉用多胎品系研究,发现BB和B+基因型群体平均产羔数分别为2.8和2.3,显著高于++基因型群体(1.2,P<0.01).在90日龄时,BB和B+基因型群体的体重分别为18.6±3.70 kg和18.0±3.31 kg,显著高于++基因型群体(15.6±2.22kg,P<0.05);此外,90日龄时,BB和B+基因型群体比++基因型群体胸围、胸宽较大(P<0.05);但这些差异在120日龄时消失.另外,我们还发现不同地区群体的第一胎产羔数存在明显差别.这些结果表明,BMPR-IB基因为影响绵羊产羔数的主效基因,并首次证明该基因对后代羔羊出生后生长发育具有加性效应.     

Associations of Body Mass and Body Fat Distribution with Parity Among African-American and Caucasian Women: The CARDIA Study

Associations of parity with body fat and its distribution are poorly understood; therefore, we examined the relationships between parity and obesity in young adult women. Body mass index (BMI), skin folds, and waist-hip ratio were compared in 1452 African-American and 1268 Caucasian nonpregnant women aged 18 to 30, adjusting for age (where no age-parity interactions were present), education, physical activity (assessed by questionnaire) and fitness (assessed by graded exercise test), dietary fat intake, alcohol and smoking. Adjusted mean BMI was significantly higher in African-American women aged 25–30 years with three or more children (28.5 kg/m²) than in those with two (27.0 kg/m²), one (26.2 kg/m²), or no children (26.3 kg/m²). Similar trends were found in Caucasians (BMI = 23.3, 23.4, 23.7, 25.0 kg/m² for parity = 0,1, 2, ≥ 3, respectively), but the mean BMI was significantly higher in African Americans in each parity group. The association between BMI and parity was not present among women 18–24 years of age. Skinfolds were directly associated with parity in African Americans only. Waist-hip ratios were generally lower among nulliparous than parous women in both ethnic groups; race differences were present only among nulliparas. In conclusion, parity was associated with BMI in women aged 25 to 30 years but did not explain ethnicity-related differences in body mass.     

四眼斑水龟个体大小和体形的两性异形

研究龟鳖的两性异形对理解形态适应具有重要意义。通过测量41只(21♀,20♂)成体四眼斑水龟(Sacalia quadriocellata)的20个形态特征指标,研究四眼斑水龟个体大小和体形的两性异形。结果表明:除头长、头宽、尾长和尾长肛前段长外,四眼斑水龟其他的形态特征均与背甲长呈正相关。雌性的背甲长、腹甲长、腹甲中线长、腹甲曲线长显著大于雄性;雄性的头长、头宽、后肢长、尾长和尾长肛前段长显著大于雌性;雌雄两性的体重、体周长、前肢长、腹甲宽、肛盾切口长、肛盾切口宽以及除背甲长外的所有背甲形态特征指标均无显著差异。研究结果表明,四眼斑水龟存在个体大小和体形两性异形。     

Test of the Optimal Body Size Model for Strepsirhines

We determined if data on strepsirhine body and home range sizes support an optimal body size (OBS) model of 100 g, as predicted from studies of energetics in terrestrial mammals. We also tested the following predictions of the OBS model: 1) relationships between body and home range sizes will change slope and sign above and below the OBS threshold of 100 g and 2) best-fit lines for OBS regression models (above and below the 100-g threshold) will intersect at ca. 100 g (range of 80–250 g). We collected data on body mass, home range size, and vertical ranging behavior for 37 strepsirhines from the literature. Linear regression analyses and phylogenetic independent contrasts methods revealed that body size is a significant determinant of both 2-dimensional (ha) and 3-dimensional (km³) home range sizes only in taxa weighing >100 g. There were consistent changes in the sign of the slopes above and below the OBS threshold. The intersections of the best-fit lines were within the OBS range for the body size to 3-dimensional home range comparisons. Thus, the data provide some support for the OBS model in strepsirhines. However, no regression model was statistically significant for the taxa below the OBS threshold, which may reflect small sample sizes. Also, no slope differed significantly between taxa above and below the OBS. Significant correlations between body and home range sizes for the complete data sets refute the √-shaped constraint space predicted via the OBS model.     

Effect of Regain of Body Weight on Regional Body Fat Distribution: Comparison Between Pre- and Postmenopausal Obese Women

The aim of our study was to determine if regain of body weight increases visceral fat in obese women and if regain of weight has a different effect upon pre- and postmenopausal women. Twenty obese women (11 pre- and 9 postmenopausal) underwent a very low energy diet (VLED) for 2 weeks to lose weight. They then regained body weight in spite of the recommended hypocaloric diet. No significant modifications in body fat distribution indexes were found by computed tomography between VLED and after regain of weight. No significant changes were found in metabolic variables. No interactions between menopausal status and regain of body weight were observed. In conclusion, regain of weight does not seem to cause an increase in visceral fat; both pre- and postmenopausal women showed the same body fat distribution before weight loss and after regain of weight.     

Genetic and Environmental Influences on the Tracking of Body Size from Birth to Early Adulthood

Objective: This study identified genetic and environmental influences on the tracking of body size from birth to 16 to 18.5 years of age. Research Methods and Procedures: Longitudinal information was collected from a nationally representative sample of Finnish twin adolescents (birth cohorts 1975 to 1979) and their parents through questionnaires mailed when the twins were ages 16 and 18.5 years old. The sample included 702 monozygotic, 724 same‐sex dizygotic, and 762 opposite‐sex dizygotic sets of twins. The measures used were length, weight, ponderal index (kilograms per cubic meters), and gestational age at birth, and height, weight, and body mass index (kilograms per square meters) at 16 to 18.5 years of age. The changes in genetic and environmental influences on body size from birth to early adulthood were analyzed by quantitative genetic modeling. Results: The twins who had a higher weight or ponderal index at birth were taller and heavier in early adulthood, whereas those who were longer at birth were taller, but not heavier, later in life. Adult height was affected more by the birth size than body mass index. In the genetic modeling analyses, the genetic factors accounting for the variation of body size became more apparent with age, and both genetic and environmental influences on stature had a sizable carry‐over effect from birth to late adolescence, whereas for relative weight, the influences were more age‐specific. Discussion: The genetic and environmental architecture of body size changes from birth to adulthood. Even in monozygotic twins who share their genetic background, the initially larger twin tended to remain larger, demonstrating the long‐lasting effects of fetal environment on final body size.