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1.
The impact of certain exogenous factor (socio-economic, ecological) has been investigated with special attention paid to the parents' living standard, and number of family members on some anthropometric parameters like: body height, body mass, chest circumference, upper leg circumference, upper arm circumference, sitting height, arm length, leg length, pelvis width, shoulders width, lenght of head and with of head on the sample of 698 boys aged 11 to 16 (17) years in the Tuzla region (the northeastern Bosnia, Western Balkan peninsula). Anthropometric measurements have been carried out using methodology proposed by the International Biological program (IBP). The results of these investigations have shown that there is a certain impact of the socio-economic conditions on the growth and development of boys. Children from families that have better living standard are, as a rule, taller, which is indicated by the statistical significant differences (P > 0.01). This trend indicates also value of Body Mass Index (BMI), which is in younger children from the families with lower living standard 16, while in the same category in the children from the families with better living standard it has value 18.5. The real impact of living conditions on the dynamics of development could be the best seen in the period of puberty. The number of children in the family has negative relationship with anthropometric features. Statistically significant differences (P > 0.001) have been detected in numerous analysed features in families with one or two children in comparison with families with three, four, or five children. Therefore, BMI has been significantly lower (16) in children from families with several children, while in the families with one child in the same growth class (11 years) it was significantly higher (17.4). Similar value of BMI (17.9) have children from the families with five children and which are 17 years old. Besides socio-economic conditions, high level of environmental pollution which is typical for Tuzla region for a long time, has also significant impact on the growth and development of children.  相似文献   

2.
Data from the 1974 Korean National Fertility Survey were analyzed to learn more about the main determinants of infant and child mortality in the course of mortality decline and how they change. In the Korean survey, about 5000 eligible women were selected for the individual survey and the sample design aimed at a self-weighting nationally representative and probability sample. Preliminary analysis showed clear mortality differentials between different socioeconomic levels and between demographic subgroups in infant and child mortality during the period 1955-73 in Korea. To examine the net effect of each variable on mortality, the logit-linear model was used. A table shows the probability level of 4 variables -- maternal age, birth order, mother's education, and number of rooms used by household -- in Korea, when the effects of others were controlled. In the urban areas, only the socioeconomic factors were the main determinants of infant mortality on all the birth cohorts. Mother's education and number of rooms used strongly affected infant mortality in the 1955-59 and 1960-64 birth cohorts, but the effects became weaker in the 1965-69 and 1970-73 birth cohorts, and their statistical significance was reduced. In the rural areas, the effects of 3 variables -- the exception being number of rooms used -- on infant mortality were statistically significant. It is concluded that the main determinants of infant mortality in urban areas were socioeconomic factors. The main determinants of infant mortality in the rural areas were demographic in the earlier birth cohorts, but in the recent birth cohorts mother's education, a socioeconomic factor, became the main determinant while the effects of demographic variables became weaker and finally disappeared. The change in the determinants of child mortality appears to be the reverse of that for infant mortality. Prior to the introduction of the national development program, in the rural areas mother's education was the main determinant of child mortality (rural 1955-59 cohort), but with the socioeconomic development the determinants changed to give dominance to demographic factors (urban 1955-59) cohort and, in the recent period, even the effects of demographic factors on child mortality became weaker (urban 1960-69 cohort). When the differences in living status by maternal age were weaker and the competition among siblings less because of small family size, only the socioeconomic variables remained as main determinants affecting child mortality.  相似文献   

3.
Age at menarche is regarded as a sensitive indicator of physical, biological, and psychosocial environment. The aim of this study was to determine the age at menarche and its association with biological and socioeconomic factors in girls from Santa Rosa (La Pampa, Argentina). An observational cross-sectional study was carried out on 1,221 schoolgirls aged 9-15 years. Menarche data were obtained by the status-quo method. Height, sitting height, weight, arm circumference, tricipital and subscapular skinfolds were measured. We also calculated body mass index, measures of body composition and proportions, and fat distribution. To assess socioeconomic factors, parents completed a self-administered questionnaire about their occupation and education, family size, household, and other family characteristics. The median age at menarche - estimated by the logit method--was 12.84 years (95% CI: 12.71, 12.97). Compared with their premenarcheal age peers, postmenarcheal girls had greater anthropometric dimensions through age 12. After this age, only height was higher in the latter group. Data were processed by fitting two logistic regressions, both including age. The first model included anthropometric variables and birth weight, while the second model included the socioeconomic variables. The significant variables derived from each model were incorporated into a new regression: height, sitting height ratio (first model), and maternal education (second model). These three variables remained significantly associated with menarche. The results suggest a relationship between linear growth and menarche and agree with those found in other populations where the advancement of menarche is associated with improved living conditions. In relatively uniform urban contexts, maternal education may be a good proxy for the standard of living.  相似文献   

4.
This study investigated the impact of some socioeconomic, demographic and health and community factors on chronic malnutrition or stunting in Bangladeshi children aged less than 5 years. The analysis revealed that the overall prevalence of stunting was 44%, of which 18% of children were severely stunted, and the demographic characteristics appeared to be the most significant factors for chronic malnutrition. Multinomial logistic regression analysis showed that parents' education, household economic status, media exposure, number of under-5 children, place of delivery, child's age, birth order, months of breast-feeding, birth size, mother's BMI, mother's height, age of household head, measles vaccine, supplementation of diet with liquids and regional differentials were significantly associated with severe as well as moderate stunting.  相似文献   

5.
甘肃省经济增长与环境压力关系动态变化的结构分解分析   总被引:1,自引:0,他引:1  
基于宏观环境经济学思想,建立了以污染物排放为表征的环境压力函数,并运用结构分解分析(SDA)模型,结合“修正后的Laspeyres方法”,构建了用于分析和解释“经济增长-环境压力”关系动态变化的驱动因子及其影响程度的方法,并分析了1990-2005年甘肃省经济增长与环境压力之间时序关系的变化趋势以及各驱动因素对时序关系变化的影响程度.结果表明:研究期间,甘肃省由污染物排放所产生的环境压力主要是由经济增长过程中产生的废气和工业固体废弃物所致,且环境压力在后期呈现出较快的增长趋势;人口因素对甘肃省环境压力变化的影响不大,经济增长因素对环境压力增大具有明显的正向效应,而技术因素则相对表现出抑制效应,但不足以抵消经济增长带来的正向效应,且经济增长和技术因素对环境压力的影响程度视不同类型污染物而有所差异.  相似文献   

6.
The influence of cigarette smoking during pregnancy and other familial factors on size at birth and gestation length is investigated among 458 births to 227 mothers living in a suburban community in the U.S. In this sample, 56% of the births were to mothers who reported not smoking during the pregnancy and 35% were to mothers who reported smoking 20 cigarettes or less. Multiple stepwise regression analysis was employed to examine the influence of cigarette smoking after statistical adjustment for such social and biological characteristics of the family as parents' sizes, education, income, and aspects of mother's reproductive history. After correction for significant social and biological characteristics, smoking status was a significant contributor to birth weight variation. In fact, cigarette smoking had the next-largest partial correlation coefficient (r = -0.26) second to gestation length. Birth length is also negatively associated with cigarette smoking, though not so strongly as is birth weight. The reduction in birth lengths can be attributed to the reduction in birth weights. Gestation length was not associated with cigarette smoking in this sample. The analysis of collinearity between smoking status and the other independent variables indicates that the effect of smoking appears to be independent of interrelationships among the independent variables.  相似文献   

7.
Biodiversity conservation, as an environmental goal, is increasingly recognized to be connected to the socioeconomic well-being of local communities. The development of a widespread community-based natural resource management (CBNRM) program in Namibia makes it an ideal location to analyze the connection between conservation and socioeconomic well-being of local communities. Namibia’s CBNRM program involves the formation of communal conservancies within rural communities and previous studies have found it to be successful on both ecological and economic fronts. In order to broaden the understanding of the program’s impact to include social factors, we have conducted a comparative analysis to determine the effects of this program on household welfare outcomes. Data from two rounds of the Namibia Demographic and Health Surveys (2000 and 2006/07) and quasi-experimental statistical methods were used to evaluate changes in various health, education and wealth outcomes of those living in conservancies, relative to non-conservancy comparison groups. Regression results indicate mixed effects of the conservancy program at the household level. The program had positive effects on some health outcome variables, including bednet ownership, which was twice as likely to increase over time in conservancy compared to non-conservancy households. Program impacts were negative for education outcomes, with the proportion of school attendance of conservancy children being 45% less likely to increase over time than non-conservancy children. Wealth outcome results were inconclusive. Our findings highlight the importance of analyzing community conservation programs at a variety of scales when evaluating overall impact, as community-level benefits may not necessarily extend down to the household level (and vice versa).  相似文献   

8.
Malnutrition among children is prevalent in almost all the states in India. This study assesses the extent and causes of malnutrition in two eastern Indian states with similar climates, namely West Bengal and Assam, using data from the National Family Health Survey 1998-99 (NFHS-2). The three indices of malnutrition taken for analysis are weight-for-height (WHZ), height-for-age (HAZ) and weight-for-age (WAZ). These are assumed to depend on birth order, preceding birth interval, parent's educational status, working status of the mother, mother's age at delivery of the children, source of drinking water, toilet facilities and standard of living of the household. Logistic regression was carried out separately for each of the three indices on the explanatory variables for both the states. It was found that not all variables are equally important in determining whether a baby is underweight, or suffering from acute or chronic malnutrition. Also, the importance of variables is not the same in the two states. It was observed that the coefficients associated with the variables in determining weight-for-height are not significant compared with those for weight-for-age and height-for-age.  相似文献   

9.
Early growth in male and female fallow deer fawns   总被引:5,自引:1,他引:4  
In this paper we present data from a long-term study on earlygrowth and related variables in fallow deer fawns living inlarge enclosures. Pre-winter body mass was constantly higherand more strongly correlated to subadult body mass in malesthan in females. To find out the mechanism for this higher pre-wintermass in males, we analyzed the variation in pre-winter massin relation to sex, year, mother's body mass, age and parityof mother, birth date, birth mass, growth rate, suckling behavior,and other behaviors. Birth mass was higher for male fawns, andgestation length, birth date, and weaning date did not differbetween the sexes. Consequently, both pre- and postnatal growthwere faster in males than in females. No behavioral differenceswere found between the sexes that could explain the differencein postnatal growth. Pre-winter mass was positively relatedto mother's body mass. Heavy mothers gave birth earlier andto larger offspring who grew at a higher rate, independent ofoffspring sex. However, male fawns born to primiparous mothershad relatively lower growth than male fawns born to multiparousmothers. This was not the case for female fawns. Suckling timeafter the first 2 weeks was positively related to mother's bodymass and growth of offspring. However, no measurements of sucklingbehavior differed between male and female fawns. Our results,except for the effect of parity on male and female growth, indicatethat selection has not acted on mothers to promote faster earlygrowth in males.  相似文献   

10.
The differential impact of diarrhea, respiratory infections, and protozoan parasitism on growth is investigated among children under five years of age living in periurban Kathmandu, Nepal. The children's parents are all carpet-making workers who live in an environment with crowded living conditions, poor sanitation, and contaminated water. Anthropometric data, both cross-sectional and longitudinal, were collected over a 9-month period. Morbidity data were gathered from maternal reports, and a subsample of children's stools were examined for gastrointestinal parasites. In a comparison of current growth status and growth velocity for children with and without diarrhea and respiratory infections, it is found that body weight is most affected by infections, particularly for children under 24 months of age. For a subsample of children whose stools were tested for parasites, there is a statistically significant association between stunting (low height-for-age) and the presence of a protozoan gastrointestinal parasite. It is concluded that although growth faltering is associated with diarrhea and respiratory infections, the impact of these infections is of less importance for long-term linear growth retardation than is infection by protozoan gastrointestinal parasites.  相似文献   

11.
Background and aimsThe placenta is a remarkable organ which provides critical transport functions between the maternal and fetal circulations during pregnancy. The demand for mineral components increases during the gestational period, therefore, an appropriate intake of minerals, such as calcium, phosphorus, potassium, magnesium, iron, zinc, copper, and manganese, determines the correct growth and development of a fetus. The aim of the study was to assess the concentration of selected elements in the placenta, and to assess the impact of their concentrations on the birth weight and birth length of newborns. The second aim of the study was to assess the influence of selected sociodemographic factors on the concentration of elements in the placenta.ResultsThe study demonstrated that the age of mothers affected the concentration of Ca and Mn in the placenta, and their habit of tobacco smoking during the gestational period was associated with higher concentrations of Ca, P, K, Mg, Fe, Cu, and Cd in the placental tissue. The results also showed that concentrations of K, Fe, Zn, and Mn in the placental tissue affected birth length. Furthermore, the association was demonstrated between a higher Cd concentration in the placenta (≥ 0.0503 μg/g) and the birth anthropometric parameters of neonates.ConclusionsSmoking during pregnancy and environment pollution are the factors that affects the concentration of elements in the placenta and contributes to their high accumulation in the placenta. Smoking during pregnancy causes an increased concentration of cadmium in the placenta which has negative health effects for the newborn. Women living in a big city or village had a higher concentration of cadmium in their placentas compared to women living in smaller cities. The significant influence of some elements (K, Fe, Zn, Cu and Cd) on the newborn’s birth parameters was also demonstrated. The results of our research indicate the importance of the mother’s lifestyle in providing the placenta with elements, which affects the growth of the fetus.
  • •The placenta is an organ that is responsible for the proper course of pregnancy and fetal development.
  • •The demand for mineral components increases during the gestational period, therefore, an appropriate intake of minerals determines the correct growth and development of a fetus
  • •Increased exposure to arsenic, cadmium and lead during the gestational period can induce miscarriage, premature delivery, risk of fetal death, inhibition of intrauterine growth and development of the fetus, and low birth parameters.
  相似文献   

12.
主要部门和重点行业的二氧化碳排放是区域碳排放的主要来源。厘清行业碳排放影响因素,分析其与区域经济增长相互关系及程度,从而推动部门和行业碳减排对于落实区域碳排放总量控制具有重要意义。本研究运用对数平均迪式指数分解法(LMDI)和Tapio脱钩模型对福建省1997—2017年13个主要碳排放行业进行碳排放驱动因素分解和脱钩分析。结果表明: 电力、热力的生产和供应业是福建省主要的碳排放行业,1997—2017年,其碳排放总量由18.89 Mt上升到120.63 Mt,增长量为101.74 Mt。有色金属冶炼及压延加工业、纺织业、黑色金属冶炼及压延加工业的碳排放增长速度最快,其年均增长率分别为18.1%、12.1%、12.1%。13个主要行业碳排放变动的驱动因素中,经济增长效应和人口规模效应是主要的正向驱动因素,能源结构效应、能源强度效应和产业结构效应的抑制作用在不断增强。从脱钩关系来看,13个主要碳排放行业的脱钩指数整体呈下降趋势。从“十一五”时期开始,部分行业开始出现不同程度的强脱钩。而在“十三五”时期,农、林、牧、渔、水利业表现为扩张负脱钩,电力、热力的生产和供应业表现为弱负脱钩。能源结构效应和能源强度效应对各行业实现脱钩的影响较大,产业结构效应的脱钩努力较小,人口规模效应未做出脱钩努力。  相似文献   

13.
Aim The use of ecological niche models (ENMs) to predict potential distributions of species is steadily increasing. A necessary assumption is that climatic niches are conservative, but recent findings of niche shifts during biological invasion indicate that this assumption is not always valid. Selection of predictor variables may be one reason for the observed shifts. In this paper we assess differences in climatic niches in the native and invaded ranges of the Mediterranean house gecko (Hemidactylus turcicus) in terms of commonly applied climate variables in ENMs. We analyse which variables are more conserved versus relaxed (i.e. subject to niche shift). Furthermore, we study the predictive power of different sets of climate variables. Location The Mediterranean region and North America. Methods We developed models using Maxent and various subsets of variables out of 19 bioclimatic layers including: (1) two subsets comprising almost all variables excluding only highly collinear ones; (2) two subsets with minimalistic variable sets of water availability and energy measures; (3) two subsets focused on temperature‐related parameters; (4) two subsets with precipitation‐related parameters; and (5) one subset comprising variables combining temperature and precipitation characteristics. Occurrence data from the native Mediterranean range were used to predict the potential introduced range in North America and vice versa. Degrees of niche similarity and conservatism were assessed using both Schoener's index and Hellinger distances. The significance of the results was tested using null models. Results The degree of niche similarity and conservatism varied greatly among the predictors and variable sets applied. Shifts observed in some variables could be attributed to active habitat selection while others apparently reflected background effects. Main conclusions The study was based on comprehensive occurrence data from all regions where Hemidactylus turcicus is present in Europe and North America, providing a robust foundation. Our results clearly indicate that the degree of conservatism of niches in H. turcicus largely varies among predictors and variable sets applied. Therefore, the extent of niche conservatism of variables applied should always be tested in ENMs. This has an important impact on studies of biological invasion, impacts of climate change and niche evolution.  相似文献   

14.
Survival rate and growth parameters of Atlantic salmon fry and sea trout fry were determined after stocking in the wild. Before release (22 May 2009) into the wild the larvae were reared for 10 weeks in the hatchery in three groups: (i) fry fed on live zooplankton , (ii) fry fed on larvae of live nekton, and (iii) fry fed on prepared pellet food. In autumn (15 September 2010) the fish were caught in the wild; the survival rate and growth parameters of both Atlantic salmon and sea trout were the highest in the zooplankton‐fed group, whilst the pellet‐fed group had the lowest survival rate and growth value parameters. Most effective food for hatchery‐reared fishes to be used as stock was the natural living zooplankton. The general conclusion is that the live diet supplied in the rearing period has a positively impact on fish survival in the wild.  相似文献   

15.
利用西双版纳热带植物园的热带植物物候观测资料和气候资料,通过对热带植物株高生长偏差、生长抽梢期和气候因子的分析,探讨了三者的关系。结果表明,热带植物生长抽梢期变长不一定影响株高生长,而且与株高生长偏差的关系也小于气候因子与株高生长偏差的关系。同时,热带植物生长抽梢期对气候因子和株高生长偏差之间关系的贡献很小。因此,可以认为热带植物的生长期对植被生产力的促进作用较弱。  相似文献   

16.
Pure stochastic birth process models are used to establish the connection between the traditional food microbiology concept of bacterial lag period, before the exponential growth, and the distribution of the lag times of individual cells. In a parallel way, similar study is carried out on the connection between the "shoulder" period, before the exponential decay, and the distribution of the survival times of individual cells. Formulae are derived to calculate the parameters of the growth/survival curves from the distributions of the respective parameters of individual cells. It is shown that, in some aspects, analogy, in some aspects fundamental difference exists between growth and survival modelling.  相似文献   

17.
Track census is a widely used method for rapid faunal assessments, which assumes that differences in track count numbers mainly reflect differences in species abundance due to some biological factors. However, some methodological and climatic variables might affect results of track censuses. Here, we tested the effect of climatic variables, such as maximum temperature, humidity, wind speed or days since last rain, and methodological factors such as censusing day period, distance from transect to vegetation edge, substrate condition or observer, on the number of tracks of mammal carnivores and some of their potential prey detected in sandy substrates. We sampled 2?×?2 km2 located within the scrubland area of Doñana National Park (southwestern Spain) for carnivore and several potential prey tracks. Our results showed differences in the number of tracks detected between observers and a significant interaction between observers and the day period when censuses were carried out. Moreover, the variables increasing the quality of the substrate (higher environmental humidity, lower wind speed and days since last rain) not only led to a greater detection of carnivore tracks but, depending on the size of the species sampled other variables such as distance from transects to the vegetation border, also affected results. We recommend restricting sampling to certain fixed weather conditions when planning to monitor relative animal abundance from track censuses. When not possible, climatic or methodological variables should be included as covariates in analyses that try to test for the biological factors affecting wildlife abundance, taking into account that these variables, which affect the number of tracks detected could vary between years.  相似文献   

18.
With the aim of determining the connection between the indicators of body posture and latent structure of morphological variables in children aged 7 and 8 years, first and second grade of primary school, a set of 17 morphological measures and 12 body posture indicators were longitudinally applied to a sample of 110 boys and 114 girls. The latent structure of morphological variables in both sexes was defined by three factors but at a different order of significance: in boys, the order was longitudinal dimensionality, voluminosity, mass and subcutaneous fat tissue and transverse dimensionality, whereas in girls the order was voluminosity, mass and subcutaneous fat tissue, longitudinal dimensionality and transverse dimensionality. The latent structure of torax body posture indicator was defined by two factors, the status of body posture of the rear part of the thorax, and status of the body posture of the front part of the thorax. The results obtained by canonical correlation analysis between predictive variables, morphological latent structure and criterion variables, latent structure of thorax body posture indicators with two posture indicators of the chest and one of the foot status, showed two important pairs of canonical roots on each measurement, suggesting a significant association between these two sets of parameters.  相似文献   

19.
This study estimated the genetic and environmental determinants of plasma leptin and insulin levels and of obesity‐related phenotypes. Included in this analysis were family members from 80 families living in kibbutz settlements, who participated in two examinations 8–10 years apart. We estimated that polygenes explained 30–50% of the adjusted leptin and insulin levels and 30–70% of the anthropometric phenotypes. This study demonstrated a significant genetic influence on longitudinal changes in leptin and BMI (h2 = 0.45) and small‐to‐moderate heritability estimates for changes in insulin and other obesity‐related phenotypes. In bivariate genetic analyses, we observed positive genetic correlations between leptin and anthropometric phenotypes, suggesting that shared effects of the same sets of loci account for 20–30% of the additive genetic variance in these pairs of variables. Shared genetic factors also account for 20–25% of the additive genetic variance in insulin—anthropometric pairs of variables.  相似文献   

20.
半干旱沙地封育草场的植被变化及其与土壤因子间的关系   总被引:14,自引:3,他引:14  
杨晓晖  张克斌  侯瑞萍  慈龙骏 《生态学报》2005,25(12):3212-3219
封育措施是一种主要的草场恢复和重建的措施。通过对半干旱沙地完全封育、季节封育和未封育地的比较分析,量化了不同封育措施下植被变化及其与土壤因子的关系。对3种封育措施群落组成和生物多样性的多响应置换过程(M RPP)分析结果表明,封育改变了群落的组成成分并增加了生物多样性,群落的指示种分析及样方相似性指数计算结果则显示,完全封育(>10a)的群落逐渐向旱生化发展,各植物种分布的空间异质性显著提高,放牧价值开始降低,而季节性封育则明显处于一种非平衡的稳定状态。对不同措施下植物种与土壤因子间关系除趋势对应分析(DCA)和除趋势典范对应分析(DCCA)排序结果表明,土壤水分状况是限制3种措施中植物种组成的决定性因子,生物结皮盖度、土壤有机质和土壤容重等因子均在一定的程度上对水分产生影响,其中最为突出的因子是生物结皮盖度,由于长期缺少牲畜的践踏,完全封育区内结皮发育较好,这也是导致群落向旱生化发展的原因之一,同时一些重要因子诸如降水的时空变化或由此而引发的土壤水分的时空变化在本研究中可能被忽略。相关分析表明3种措施的生物多样性除了受土壤水分状况(土壤含水量和结皮盖度)的影响外,还与土壤速效氮呈正相关,与速效磷呈负相关。  相似文献   

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