布氏田鼠种群趋势预报指标的研究

布氏田鼠种群季节消长为单峰型,年际动态没有周期性。通过分析该鼠繁殖特征、生活史特征及种群结构,提出了5个对预测种群数量动态趋势有价值的指标,即:4月下半月越冬田鼠的怀孕率;4月下半月越冬鼠平均胴体重:越冬鼠春季(4～5月)平均胎仔数:5月下半月当年生鼠占种群的比例;当年生鼠开始繁殖的时间。同时对该鼠种群数量波动机制进行讨论。     

越冬布氏田鼠生长和繁殖状况分析

通过对１９９２～１９９４年４月下旬越冬布氏田鼠生长和繁殖状况的分析，揭示布氏田鼠在数量低潮期生长状况欠佳，随种群数量回升而逐年变好。与此相应越冬雌体的怀孕率和平均胎仔数也由０逐年上升。通过与１９８７和１９８８两年资料的综合分析，揭示了布氏田鼠种群数量变动的周期规律。     

田鼠亚科鼠类年龄划分探讨

通过分析布氏田鼠的生活史特征证明,在划分田鼠亚科鼠类年龄组时,考虑生理学年龄十分必要。运用胴体重分布区分出越冬田鼠与当年生田鼠颇为重要,但应用形态学或时间学年龄指标来划分年龄组似无必要。作者认为,刘于当年生田鼠,只需划分为性成熟和性不成熟两组即可。     

布氏田鼠综合防制的研究

综合防制布氏田鼠是一项复杂的牧业生态工程。退化草原是布氏田鼠生存的最适宜环境,已经退化的草原应在短期内禁牧,或采用围栏、补播、浅耕翻等措施,使草原尽快恢复生产力,造成不适宜布氏田鼠栖息的环境;平时应对主要害鼠种群数量和群落演替情况进行监测,为防制提供依据;一旦发生鼠害,及时用抗凝血杀鼠剂灭鼠,把鼠密度控制在不足为害的程度;并保护和招引鼠类天敌,禁止对天敌滥捕滥杀。     

板齿鼠肥满度季节变化的特征分析

目的阐明不同性别、年龄组板齿鼠肥满度的变化以及季节差异。方法计算肥满度和差异性检验。结果板齿鼠的平均肥满度为(2.96±0.60)g/cm3,两性间肥满度差异极显著。结论对板齿鼠肥满度进行研究,可揭示其种群生态学方面的规律。     

大沙鼠肥满度的研究

目的：阐明不同性别，不同年龄组大沙鼠肥满度的变化以及年度，季节差异。方法：计算肥满度和差异性检验。结果：大沙鼠肥满度，性别间差异无显著性；各年龄组差异无显著性；季节间差异有显著性。肥满度与种群密度呈不显著的负相关。结论：利用统计学方法对大沙鼠肥满度进行多层次研究。可揭示其种群生态学方面的规律。     

当涂县农区灭鼠后鼠类种群数量变动调查

灭鼠后调查鼠的种群数量变动,在生产实践中具有重要意义,且可掌握当地一年内最佳灭鼠时机和次数。国内曾见有草原灭鼠后布氏田鼠数量消长、农村居民区灭鼠后家鼠数量变动的报道。但对农田和农村居民区同时灭鼠后鼠类种群组成及数量变     

布氏田鼠的实验动物化饲育和主要脏器系数测定

目的:建立布氏田鼠实验动物化的饲育方法。方法:我们引入布氏田鼠后,采用药物净化法控制其体内外的微生物和寄生虫进行实验动物化,确定了在屏障环境中针对该动物的饲养、配种、麻醉以及输精管结扎的技术流程;并检测了布氏田鼠的主要脏器系数指标。结果:初步建立了布氏田鼠人工饲养的清洁级封闭群。群体内成年雄性布氏田鼠的肝脏、肾脏和脾脏的器官系数与雌性的差异达到显著性水平(P0.05)。结论:本实验确定的饲育方法为同类鼠种的实验动物化工作提供了参考。     

布氏田鼠种群动态预测初报

本文对布氏田鼠种群数量的年际动态和季节动态作了初步分析,并根据雌鼠怀孕率、雌鼠亚成比和性比三项种群特征,提出预测布氏田鼠种群动态的三个短期(2～4个月)方程式。     

布氏田鼠日食量研究

目的室内条件下测定不同年龄和性别布氏田鼠的日食量。方法参照《动物生态学原理》用布氏田鼠喜食植物喂养24h后，计算供食量与残渣的差值。结果（1）布氏田鼠平均日食量（干重）为（9．9361±0．2383）g。成体组平均日食量略高于亚成体组和老体组，且不同年龄组田鼠日食量差异有统计学意义（P〈0．05）。其中亚成体组平均日食指数较高。（2）3个年龄组中不同性别平均日食指数差异均无统计学意义，即性别对布氏田鼠取食无显著影响。（3）亚成体布氏田鼠体重与日食量呈正相关性，y=0．2882w＋2．099（R^2=0．8191）；老体鼠体重与日食量呈负相关，y=0．1565w＋19．034（R^2=0．5652），成体鼠体重与日食量无显著相关。结论不同年龄组体重与日食量之间存在不同的相关关系，如果根据体重来估算布氏田鼠的危害，必须先掌握该季节布氏田鼠的年龄结构和相应的种群密度，且还应考虑季节性特点和繁殖期生理特点。     

Body fatness and frame size: the Caerphilly study

The effect of adjusting height-weight indices for frame size on the prediction of body fatness was investigated in a community sample of 2512 men aged 45-59 years. Body fatness was assessed from skinfold thickness measurements at four sites: triceps, biceps, subscapular and supra-iliac. Body diameters (biacromial, bi-iliocristal, wrist or knee) were used as estimates of frame size. Body diameters were not independent of body fatness, wrist diameter showing the lowest association with skinfold thickness measurements. Adjustment of weight/height2 (W/H2) for frame size had little effect on the prediction of body fatness, the correlation coefficient for body fatness with W/H2 (r = 0.76) being almost identical to that for W/H2 adjusted for wrist diameter (r = 0.74).     

Adolescent skinfold thickness is a better predictor of high body fatness in adults than is body mass index: the Amsterdam Growth and Health Longitudinal Study

BACKGROUND: Body mass index (BMI) during adolescence is predictive of BMI at adult age. However, BMI cannot distinguish between lean and fat body mass. Skinfold thickness may be a better predictor of body fatness. OBJECTIVE: The objective of this study was to evaluate the relations between BMI and skinfold thickness during adolescence and body fatness during adulthood. DESIGN: We included 168 men and 182 women from the Amsterdam Growth and Health Longitudinal Study, a prospective study that conducted 8 measurements of BMI and skinfold thickness between 1976 and 2000. BMI and skinfold thickness during adolescence were analyzed in relation to adult body fatness measured at a mean age of 37 y with dual-energy X-ray absorptiometry. RESULTS: None of the boys and 1.7% of the girls were overweight at baseline, whereas the prevalence of high body fatness during adulthood was 29% in men and 32% in women. At the ages of 12-16 y, skinfold thickness was more strongly associated with adult body fatness than was BMI. Age-specific relative risks for a high level of adult body fatness varied between 2.3 and 4.0 in boys and between 2.1 and 4.3 in girls in the highest versus the lowest tertile of the sum of 4 skinfold thicknesses. For the highest tertile of BMI, the relative risk varied between 0.8 and 2.1 in boys and between 1.3 and 1.8 in girls. CONCLUSION: Skinfold thickness during adolescence is a better predictor of high body fatness during adulthood than is BMI during adolescence.     

褐家鼠的生长发育

目的 :观察、分析从出生至 10 0日龄褐家鼠的生长和发育情况 ,并通过野外调查 ,分析研究褐家鼠的肥满度。方法 :在室内饲养条件下 ,每隔 5d对幼鼠进行称重、测量 ;肥满度研究则是对野外褐家鼠进行称量、解剖、分析。结果 :10 0日龄前褐家鼠体重增长与日龄成直线关系 :W =6.85 5± 1.135t (r =0 .9930 >t0 .0 1) ;体长与日龄关系为指数增长关系 :L =44 .12 112 .772 5 - 13.0 586/t;尾长、后足长、耳长与日龄关系均为指数增长关系 ,其方程分别为 :M =14 .92 111.0 189- 13.0 586/t、F =8.39 2 8.6915 - 10 .5778/t、E =1.5 8 16.5 813- 8.8681/t。体重与体长关系为 :W =3.5 88× 10 - 4L2 .4 82 。结论 :根据对野外种群的研究表明 ,褐家鼠肥满度随年龄组增长而增加 ,种群肥满度秋季大于冬季。     

Seasonality of growth in Shanghai infants (n=4128) born in 11 consecutive years

OBJECTIVE: To describe the seasonal growth patterns in Shanghai infants, to explore seasonal time lag between weight gain and length gain, and to investigate the long-term effect of birth season on early postnatal growth. DESIGN: Community-based longitudinal study. SETTING: Shanghai, People's Republic of China. METHOD: Children were followed up monthly from 1 to 6 months, 3 monthly from 6 to 12 months, and 6 monthly from 12 to 24 months. SUBJECTS: A total of 6018 children born between 1 January 1980 and 31 December 1990. MAIN OUTCOME MEASURES: Weight gain, length gain and change in body mass index (BMI) over the seasons of the year. RESULTS: The infants tended to grow faster in height in spring and summer, and faster in weight and BMI in autumn and winter. The seasonal effect on weight gain and length gain is largely independent. The mean length value at 1 month of age was about 2.0 cm higher in infants born in May to July than in those born in November to February. At 24 months of age this difference was reduced to about 0.7 cm. CONCLUSIONS: There is a clear and consistent seasonality in growth in Shanghai infants. The seasonality seems to act independently on weight and length. Birth month has some association with attained size, but this is reduced during the first 2 y of life.     

Relationship of body composition to body-fatness estimation in Japanese university students

OBJECTIVE: To examine the relationship between self-estimated whole body size and fatness and whole body and regional composition, and the relationship between self-estimated whole body fatness and self-estimated regional fatness in Japanese university students. RESEARCH METHODS AND PROCEDURES: This was a cross-sectional study using Japanese university students (110 men and 79 women). The percentage of body fat, fat mass (FM), and fat-free mass (FFM) were measured by underwater weighing and used as body composition variables. Subcutaneous fat thicknesses were determined at seven sites by ultrasonography to estimate regional body composition, and six circumferences and four breadths to estimate regional size. Relative body size and fatness were self-estimated using a questionnaire. RESULTS: Only women tended to estimate themselves as being fatter than they actually were. Self-estimated body fatness moderately correlated with the percentage of body fat (men, r = 0.41; women, r = 0.40) FM (men, r = 0.50; women, r = 0.51), and body mass index (r = 0.56 for men and 0.56 for women). After adjusting for the percentages of body fat and FM, self-estimated fatness correlated with body mass index (r = 0.31 for men and r = 0.37 for women). Among self-estimated regional fatness, self-estimated abdominal fatness had the strongest correlation with self-estimated whole body fatness in both genders. DISCUSSION: The low correlation between estimated and actual body fatness in both genders indicates that Japanese university students, especially women, inaccurately estimate their percentage of body fat. In fact, both men and women primarily estimate their whole body fatness by body weight relative to height.     

Obesity prognosis: a longitudinal study of children from the age of 6 months to 9 years

The development of body fatness and leanness is examined in an ongoing prospective nutrition and growth study. Individual skinfold thicknesses, relative weights, weight gains, activity levels, and caloric intakes were examined at seven ages between 6 months and 9 years. Changes in body fatness in this group of children provide evidence that the obese infant usually does not become the obese child. Weight gain in infancy is also a poor predictor of 9-year old obesity. Changes from obese to non-obese or lean are often not linear. There is evidence that impending or actual obesity begins at ages 6 to 9 years with some predictability provided as early as age 2 years for girls, age 3 years for boys.     

Pattern of birth in early-onset anorexia nervosa: an equatorial study

OBJECTIVE: Patients with anorexia nervosa (AN) born in the northern and southern hemispheres are more likely to be born during spring months than at any other time of the year. It has been hypothesized that environmental temperature at the time of conception may have a significant role in this pattern of findings. The current study aims to investigate the pattern of birth of early-onset AN patients in an equatorial region (Singapore), where there is little difference in environmental temperature throughout the year. METHOD: Dates of birth were collected for 102 patients who were born in Singapore and diagnosed with early-onset AN. The patterns of birth were analyzed using chi-square analysis. RESULTS: There was no difference across the year in the birth patterns of patients with early-onset AN in Singapore, nor were there any differences between patients with restrictive and binge/purge AN. DISCUSSION: This lack of seasonal variation in the equator adds support to the "temperature at conception" hypothesis.     

Fitness and fatness as predictors of mortality from all causes and from cardiovascular disease in men and women in the lipid research clinics study

The relative size of the effects of fitness and fatness on longevity has been studied in only one cohort. The authors examined this issue using data from 2,506 women and 2,860 men in the Lipid Research Clinics Study. The mean age was 46.6 years in women and 45.1 years in men at baseline (1972-1976). Fitness was assessed using a treadmill test, and fatness was assessed as body mass index calculated from measured height and weight. Participants were followed for vital status through 1998. Hazard ratios were calculated using proportional hazard models that included covariates for age, education, smoking, alcohol intake, and the dietary Keys score. Fitness and fatness were both associated with mortality from all causes and from cardiovascular disease. For mortality from all causes, the adjusted hazard ratios were 1.32 among the fit-fat, 1.30 among the unfit-not fat, and 1.57 among the unfit-fat women compared with fit-not fat women. Among men the same hazard ratios were 1.25, 1.44, and 1.49 [corrected]. There were no significant interactions between fitness and fatness in either men or women. The authors conclude that both fitness and fatness are risk factors for mortality, and that being fit does not completely reverse the increased risk associated with excess adiposity.     

The growth of young children in a Gambian village

A detailed study of the growth and health of 215 children under 5 years in the village of Keneba (Gambia) during 1962-1963 was conducted. At the same time, outline information was collected in 3 adjacent villages--Jali, Manduar, and Kantongkunda. There were 99 live births during 1962-1963. It became obvious during the 1st year of the study that season exercised a marked effect on trends in body weight, and it became necessary to define the seasons. Data from children who died during the survey period were excluded. Of the 99 liveborn babies, 93 were measured within 3 days of birth. The data suggested that birth weights were on average lower during the wet than the dry months, but the differences between the quarter years were not statistically significantly. There was no indication that the weight gains in the 1st 6 months of small babies differed from those of large babies. The seasonal effect was slight during the early months of life but became obvious at later ages. Children born in the early part of the year gained very well until nearly the end of their 1st rainy season, when there was a short setback. Children born during the wet months grew well until the onset of the rains in the following year. Those born during the earlier part of the dry season received a marked check to growth soon after entering the wet months. Both season of birth and age dictated the average pattern of gain in weight during the 1st year of life. Until about 6 months of age, season made little difference to rates of gain in Keneba, but thereafter increments were about zero or slightly negative during the wet months with some catch up during the dry months. The Keneba babies grew much faster than American babies during the first 3 months of life, but much more slowly during the 2nd half of the 1st year. By the end of the 2nd year the average rate of growth in height had practically caught up with the American standard. The data confirmed the previous finding that, in general, the growth of children who die is not very different from that of children who survive, and that the events which precede death cause effects on body weight which are of relatively short duration.