Correlates of age at first birth among the slum dwellers in Sylhet,Bangladesh

The first birth marks a transition of a woman into motherhood. It contributes substantially to overall fertility of each individual woman. The age at which childbearing begins influences the number of children a woman bears throughout her whole reproductive life span. Thus, the mother’s age at first birth influences the total number of births that she might have in her life, which impacts the size, composition, and future growth of the population. Child-bearing at very young ages is common among the poor in Bangladesh. The objective of the present study is to examine the factors associated with age at first birth among slum dwellers of five selected slums (locally, colony) in Sylhet city corporation area, Bangladesh. The data of this study was collected from 520 women aged 14–50 years. The study found that almost 93% of women were married by the ages of 18 years and about 56% of the women have had their first child by the age of 18 years. The Ordinary Least Squares (OLS) regression model was used to analyze the factors correlated with women’s age at first birth. The regression model is significant with an F-value of 49.48 and can explain 40.4% of the variation in the dependent variable as it is indicated by the R-square.     

Direct and Indirect Effects of Socioeconomic Factors on Age at First Marriage in Slum Areas,Bangladesh

This article attempts to examine the influence of some selected predictor variables on female age at first marriage in slum areas of Bangladesh. A path and multiple classification analysis (MCA) approach have been adopted. Authors thought that respondent’s educational level and the mass media such as watching television have a significant direct impact on age at marriage, while the types of family and occupational status have an indirect effect on age at marriage.     

Direct and Indirect Effects of Socioeconomic Factors on Age at First Marriage in Slum Areas,Bangladesh

This article attempts to examine the influence of some selected predictor variables on female age at first marriage in slum areas of Bangladesh. A path and multiple classification analysis （MCA） approach have been adopted. Authors thought that respondent＇s educational level and the mass media such as watching television have a significant direct impact on age at marriage, while the types of family and occupational status have an indirect effect on age at marriage.     

Male fertility following occupational exposure to dichlorodiphenyltrichloroethane (DDT)

BackgroundThe inconsistent epidemiological results of the endocrine disrupting effects of DDT fuel a harsh debate on its global ban.ObjectivesWe tested the hypothesis that occupational exposure to dichloro-diphenyl-trichloroethane (DDT) causes impairment in male fertility in a cohort of DDT exposed workers, in Sardinia, Italy.MethodsWe accessed official records on date of marriage and date of birth of the first child to estimate time to pregnancy (TTP) in the spouses of 1223 workers employed in a 1946–1950 anti-malarial campaign. The TTP calculation was censored at the 13th month after date of marriage. We used a modified Cox's proportional hazard model to calculate the fecundability ratio (FR) by job, by cumulative exposure to DDT, and by time window in relation to the anti-malarial operations, adjusting by paternal age at marriage.ResultsAmong the spouses of DDT applicators, fecundability did not vary during DDT use (FR = 1.22, 95% CI 0.84–1.77) nor in the following decade (FR = 1.01, 95% CI 0.67–1.50) with reference to the prior years. A significant increase occurred among the unexposed and the less exposed sub-cohorts, which generated a non-significantly reduced FR among the DDT applicator sub-cohort with reference to the unexposed following exposure.ConclusionWe did not find evidence of an impairment in male fertility following heavy occupational exposure to DDT. However, although fecundability was highest among the spouses of the DDT applicators in the years prior to the anti-malarial campaign, we cannot exclude that DDT exposure prevented an increase parallel to that observed among the unexposed and the less exposed sub-cohorts.     

Assessment of the Age Structure of Sable Samples Using Three Methods of Age Determination

The age structure of sable samples has been analyzed on the basis of parameters obtained by three methods of age determination: by annual cementum layers (Klevezal, 1988), canine root canal width (Smirnov, 1960), and the degree of development of the mastication muscles and sagittal crest on the skull (Timofeev and Nadeev, 1955). It has been found that the first two methods produce similar results (r = 0.95) that are suitable for use in the practice of monitoring and commercial game management. The third method is simpler but less accurate and can be recommended only for the preliminary assessment of age ratios in populations. The results of such assessment by the method proposed by Klevezal are sufficiently accurate for a detailed analysis of population structure and dynamics of its reproductive core, but this method is laborious and involves a complicated histological procedure. When large samples are studied for the purposes of monitoring and management planning, the method proposed by Smirnov is preferable.     

Spatial Distribution of Sables in the Middle Ob Region

Results of stationary studies on the spatial location of sables (Martes zibellinaL.) belonging to different age and sex groups are summarized. Mapping the sites where 388 animals were taken, it was found that young animals tended to live near floodplains; adult animals, on watersheds. Analysis of sables taken by commercial hunters (n= 1833) made it possible to estimate the age composition and the degree and spatial distribution of the hunting pressure on sable populations in three areas of the Ob region. The spatial separation of young and reproductive animals is interpreted as a group adaptive response to the specific distribution pattern of different habitats typical of this species and to the pattern of animal elimination. It is proposed to use the specific pattern of animal distribution for maintaining the size of the population that is subject to hunting. Specifically, reserve (reproductive) territories should be organized in watershed areas.     

Welfare effects of rural-urban land conversion on different aged land-lost farmers: exemplified in Wuhan city

Rural-urban land conversion is a universal phenomenon in the rapid process of economic development and urban growth. The welfare of farmers who lost their farmland attracted a widespread concern within the society and academia. However, further research about differentiated policies according to the characteristics of different farmer groups is still need to be conducted. This article divides the land-lost farmers into three age groups: younger than 45, 45–65, and more than 65. It proposes a welfare index system including eight functional areas based on different age groups of affected farmers, taking four districts of Wuhan City as case study area. Fuzzy mathematics method is used to derive the aggregated welfare effect index. Our analysis show that the overall welfare levels of land-lost farmers of all age groups declined, but with a varying degree, with the level of welfare in those farmers who are 45–65 years old, younger than 45 years old, and older than 65 years old decreased by 18.7%, 16.6%, and 12.7%, respectively. The direction and degree of effects on the functional activity index varies among different groups. Economic conditions, living environment, health, and social participation of all age groups decrease while social security and housing conditions increase. On the other hand, development opportunities, social communication, and leisure have different changing directions in different age stages. These results call for differentiated and tailor-made compensation policies for land-lost farmers, towards improving the welfare levels of all farmers and reduce the disparity among them.     

Sea Otters (Enhydra lutris L.) of Bering Island, the Commander Islands: Age and Sex Composition of Dead Animals and Spatial Distribution

Animal censuses and assessment of mortality in the sea otter subpopulation of Bering Island (the Commander Islands) have shown that indices of seasonal mortality may be used as a criterion for estimating well-being of this animal group. In 1999, the subpopulation of Bering Island entered a phase of stabilization of its spatial, age, and sex structure, with the stabilization process proper taking approximately three years after a peak of mortality. Mortality in the course of this process proved to be relatively high in age groups older than eight years but insignificant among middle-aged reproductive animals. As the age and sex structure of the insular group varies during the year and in different coastal areas, the data obtained by collecting dead animals cannot be used for estimating the structure of the whole population.     

Assessment of the Immune Status of Women Working in the Potassium Salt Industry and Their Children

The state of the immune system was studied in the women working at the OAO Uralkalii (Berezniki) and OAO Sil'vinit (Solikamsk), where they were permanently exposed to salts and halite waste, and their children born after at least three years of such exposure. The control group consisted of women who had no occupational contact with salts and halite wastes and of their children. No significant differences between the differential leukocyte counts and immunograms of the women working at the OAO Uralkalii and OAO Sil'vinit and their children were found. The main parameters of the immune system of women and their children both in the first and second groups were within the norm.     

Dietary and sociodemographic determinants of bisphenol A urine concentrations in pregnant women and children

Bisphenol A (BPA) exposure during early life may have endocrine-disrupting effects, but the dietary and sociodemographic predictors of BPA exposure during pregnancy and childhood remain unclear. Our aim was to evaluate the correlations between, and sociodemographic and dietary predictors of, serial urinary BPA concentrations measured during pregnancy and childhood in a Spanish birth cohort study. BPA was measured in two spot urine samples collected from 479 women during the first and third trimester of pregnancy and in one urine sample from their 4-year old children (n = 130). Average dietary intakes were reported in food frequency questionnaires during the first and third pregnancy trimester and at age 4 years. Multivariate mixed models and linear regression models were used to estimate associations between sociodemographic and dietary factors and BPA concentrations. A small, but statistically significant correlation was found between serial maternal BPA concentrations measured during pregnancy (r = 0.17). Pregnant women who were younger, less-educated, smoked, and who were exposed to second-hand tobacco smoke (SHS) had higher BPA concentrations than others. BPA concentrations were also higher in children exposed to SHS. High consumption of canned fish during pregnancy was associated with 21% [GM ratio = 1.21; 95%CI 1.02, 1.44] and 25% [GM ratio = 1.25; 95%CI 1.05, 1.49] higher urinary BPA concentrations in the first and third pregnancy trimester, respectively, compared to the lowest consumption group. This study suggests that canned fish may be a major source of BPA during pregnancy in Spain, a country of high canned fish consumption. Further evaluation of specific BPA exposure sources in the sociodemographic group of younger women who smoke, are exposed to SHS, and have a low educational level is needed. Studies identifying sources of exposure would benefit from repeat BPA measurements and questionnaires specifically focused on dietary and packaging sources.     

Ecological factors influencing frequency of Norway spruce butt rot in mature stands in Lithuania

We assess the influence of edaphic, climatic, stand structure and individual tree (stump diameter) factors on incidence of Norway spruce (Picea abies (L.) H. Karst.) butt rot. The data used in the study come from 97 stands, originated from natural regeneration, which were clear-cut. The age of the stands varied between 71 and 130 years old. The climate continentality, site fertility, hydrotop (site humidity index), part of Norway spruce in the stand, stand stocking level (density index) and stump diameter were selected as the factors related with frequency of decay. The study material revealed that selected variables explain 34% of Norway spruce butt rot incidence in Lithuanian forests. Site fertility and stand age influence on butt rot incidence was weak. Higher incidence was related with low stand density, low site humidity (dry sites) and higher part of Norway spruce in stand. More frequent damages were recorded on higher diameter stumps. Our results showed longitudinal distribution of decay incidence in Lithuania—the frequency of decay increasing from West (coast) to East (continent).     

Early wheezing phenotypes and severity of respiratory illness in very early childhood: Study on intrauterine exposure to fine particle matter

The main goal of the paper was to assess the pattern of risk factors having an impact on the onset of early wheezing phenotypes in the birth cohort of 468 two-year olds and to investigate the severity of respiratory illness in the two-year olds in relation to both wheezing phenotypes, environmental tobacco smoke (ETS) and personal PM_2.5 exposure over pregnancy period (fine particulate matter). The secondary goal of the paper was to assess possible association of early persistent wheezing with the length of the baby at birth. Pregnant women were recruited from ambulatory prenatal clinics in the first and second trimester of pregnancy. Only women 18–35 years of age, who claimed to be non-smokers, with singleton pregnancies, without illicit drug use and HIV infection, free from chronic diseases were eligible for the study. In the statistical analysis of respiratory health of children multinomial logistic regression and zero-inflated Poisson regression models were used. Approximately one third of the children in the study sample experienced wheezing in the first 2 years of life and in about two third of cases (67%) the symptom developed already in the first year of life. The early wheezing was easily reversible and in about 70% of infants with wheezing the symptom receded in the second year of life. The adjusted relative risk ratio (RRR) of persistent wheezing increased with maternal atopy (RRR = 3.05; 95%CI: 1.30–7.15), older siblings (RRR = 3.05; 95%CI: 1.67–5.58) and prenatal ETS exposure (RRR = 1.13; 95%CI: 1.04–1.23), but was inversely associated with the length of baby at birth (RRR = 0.88; 95%CI: 0.76–1.01). The adjusted incidence risk ratios (IRR) of coughing, difficult breathing, runny/stuffy nose and pharyngitis/tonsillitis in wheezers were much higher than that observed among non-wheezers and significantly depended on prenatal PM_2.5 exposure, older siblings and maternal atopy. The study shows a clear inverse association between maternal age or maternal education and respiratory illnesses and calls for more research efforts aiming at the explanation of factors hidden behind proxy measures of quality of maternal care of babies. The data support the hypothesis that burden of respiratory symptoms in early childhood and possibly in later life may be programmed already in prenatal period when the respiratory system is completing its growth and maturation.     

Population Ageing and Sustainable Development Research in China

According to the United Nations population projections, the population of the elderly is expected to roughly triple in China from 2000 to 2050, particularly when the generations who were born between the 1950s and 1970s move through the age structure, and also because people are living longer and fertility rates have fallen, population aging is expected to put pressure on government's fiscal balance through higher old-age security benefits and health-care expenditures. This work draws together the broad range of elements involved within a consistent framework, based on a computable dynamic general equilibrium model with an overlapping generation structure. Further analysis using model simulation illustrates that the alternative schemes for the benefit rate, retirement age and technological progress are likely to be beneficial, and that an obvious slow-down in the growth of living standards is likely to be avoided.     

环境健康价值评估中的年龄效应研究

在环境健康价值评估研究中,统计寿命价值和年龄之间的关系是理论和实证研究焦点之一,也是重要的学术问题。长久以来,环境政策效益评估中是否应该赋予老年人较低的统计寿命价值一直存在广泛争议,且尚未得到一致性结论。通过设计选择实验,对北京市空气质量改善的健康效益进行了抽样调查,并采用MNL模型对北京市约500个居民的调查数据进行回归分析,估算了不同年龄人群对健康风险减少的支付意愿,针对中国人群中统计寿命价值和年龄之间的关系进行实证探讨。结果表明:一方面,在总体样本中设置年龄虚拟变量,回归结果表明年龄变量系数的符号均显著为负,即年龄因素对减少空气污染带来的死亡风险降低的支付意愿具有显著的影响,年龄越大支付意愿相对越小;另一方面,不同年龄人群分组样本结果显示,统计寿命价值与年龄之间呈现"倒U型"关系,统计寿命价值在中国存在"老年折扣"现象。研究结果可为我国环境政策的健康效益分析中如何考虑年龄的影响提供重要依据。     

Population Ageing and Sustainable Development Research in China

Abstract

According to the United Nations population projections, the population of the elderly is expected to roughly triple in China from 2000 to 2050, particularly when the generations who were born between the 1950s and 1970s move through the age structure, and also because people are living longer and fertility rates have fallen, population aging is expected to put pressure on government's fiscal balance through higher old-age security benefits and health-care expenditures. This work draws together the broad range of elements involved within a consistent framework, based on a computable dynamic general equilibrium model with an overlapping generation structure. Further analysis using model simulation illustrates that the alternative schemes for the benefit rate, retirement age and technological progress are likely to be beneficial, and that an obvious slow-down in the growth of living standards is likely to be avoided.     

Combining remote sensing and household level data for regional scale analysis of land cover change in the Brazilian Amazon

Land cover change in the Brazilian Amazon depends on the spatial variability of political, socioeconomic and biophysical factors, as well as on the land use history and its actors. A regional scale analysis was made in Rondônia State to identify possible differences in land cover change connected to spatial policies of land occupation, size and year of establishment of properties, accessibility measures and soil fertility. The analysis was made based on remote sensing data and household level data gathered with a questionnaire. Both types of analyses indicate that the highest level of total deforestation is found inside agrarian projects, especially in those established more than 20 years ago. Even though deforestation rates are similar inside and outside official settlements, inside agrarian projects forest depletion can exceed 50% at the property level within 10–14 years after establishment. The data indicate that both small-scale and medium to large-scale farmers contribute to deforestation processes in Rondônia State encouraged by spatial policies of land occupation, which provide better accessibility to forest fringes where soil fertility and forest resources are important determinants of location choice.     

Phthalate exposure among pregnant women in Jerusalem, Israel: results of a pilot study

BackgroundPhthalates can disrupt endocrine function and induce reproductive and developmental toxicity in laboratory animals. Few studies have evaluated exposure to phthalates in pregnant women, despite the potential sensitivity of the developing fetus to adverse effects of phthalates.MethodsWe measured urinary concentrations of 11 phthalate metabolites in 19 pregnant women, recruited in Jerusalem, Israel in 2006, and collected questionnaire data on demographic factors and consumer habits from these women. We compared geometric mean concentrations in subgroups and used the Mann–Whitney U-test for independent samples to determine significant differences between groups.ResultsNine metabolites were detected in at least 95% of the samples: mono(2-ethyl-5-carboxypentyl) phthalate, mono(2-ethyl-5-hydroxyhexyl) phthalate, mono(2-ethyl-5-oxohexyl) phthalate, mono(3-carboxypropyl) phthalate, mono(n-butyl) phthalate, monobenzyl phthalate (MBzP), monoethyl phthalate (MEP), mono(2-ethylhexyl) phthalate and monoisobutyl phthalate. Phthalate metabolite concentrations in these pregnant women were remarkably similar to those in the general United States female population. MBzP geometric mean concentrations were higher in women living in buildings existing 40 years or more (P = 0.04). In women who used four or more personal care products (perfume, deodorant, lipstick, nail polish, or hand/face cream) in the 48 h prior to providing the urine sample, geometric mean MEP concentrations were more than 4 times higher than concentrations in women using only two or three of the aforementioned products (P = 0.07).ConclusionsPregnant women in Jerusalem are exposed to a wide range of phthalates. Building materials used in old constructions may be a source of exposure to benzylbutyl phthalate, the parent compound of MBzP. Personal care products may be sources of exposure to diethyl phthalate, the parent compound of MEP.     

Predictors of concentrations of hexachlorobenzene in human adipose tissue: a multivariate analysis by gender in Southern Spain

Hexachlorobenzene (HCB) was measured in adipose tissue intraoperatively collected from 387 subjects over 16 years old undergoing surgery in two hospitals in Granada (Southern Spain). HCB was quantified in 90.7% of subjects. The concentrations and frequencies of HCB were similar to those reported in adipose tissue samples in other recent European studies. Exposure patterns differed between females and males: higher HCB concentrations were found in females than in males (geometric mean 18.3 vs. 6.8 ng/g, p<0.001). The relationship between HCB concentrations and exposure risk factors was assessed by multivariate analysis stratifying by gender. In men, HCB concentrations were predicted (r(2)=0.45) by age, body mass index (BMI), place of residence, smoking, consumption of fish, chicken and cheese, occupation related to agriculture, and family involvement in construction activities. In women, HCB concentrations were predicted (r(2)=0.50) by age, BMI, consumption of milk and cheese, and occupation related to industry. The finding that women had three-fold higher levels of HCB than the men deserves further investigation.     

Determinants of urinary bisphenol A concentrations in Mexican/Mexican–American pregnant women

Prenatal exposure to bisphenol A (BPA) may be associated with adverse health effects in the developing fetus; however, little is known about predictors of BPA exposure during pregnancy. We examined BPA exposure in 491 pregnant women from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) cohort and explored the role of living in the United States on significant dietary predictors of BPA exposure. Women provided urine samples up to two times during pregnancy (n = 866 total samples). We computed the intraclass correlation coefficient (ICC) to evaluate variability in concentrations between collections and used generalized estimating equation (GEE) models to assess predictors of exposure. Geometric mean (GSD) BPA concentrations were 0.9 (2.8) μg/L and 1.0 (2.6) μg/L at the first and second prenatal visits, respectively. We observed greater within- than between-woman variability in urinary BPA concentrations (ICC = 0.22). GEE models suggest that women who lived in the United States their entire life had 38% (CI: − 0.1, 89.3) higher urinary BPA concentrations compared with other immigrant women. Additionally, women who consumed ≥ 3 sodas per day or hamburgers three times a week or more had 58% (CI: 18.0, 112.1) and 20% (CI: − 0.2, 45.2) higher urinary BPA concentrations, respectively, compared with women who consumed no sodas or hamburgers. A higher percentage of women who lived their entire life in the United States reported increased consumption of sodas and hamburgers compared with other immigrant women. Independent of other factors, BPA urinary concentrations were slightly higher when the sample was collected later in the day. As in previous studies, high within-woman variability in urinary BPA concentrations confirms that several samples are needed to properly characterize exposure during pregnancy. Results also suggest that some factors could be modified to minimize exposures during pregnancy in our study participants (e.g., reducing soda and hamburger intake) and that factors associated with acculturation might increase BPA concentrations.     

Population structure and dynamics of Monotarsobius curtipes (Myriapoda, Chilopoda) at the northern periphery of the species range

Studies on the population structure and dynamics of the stone centipede Monotarsobius curtipes C. Koch in soils of the northern Kola Peninsula have shown that, with respect to abundance and biomass, this species is a dominant of the soil macrofauna and, in particular, of the trophic group of zoophages. Life in high northern latitudes does not disturb the sex and age structure of populations but limits the reproductive activity of these centipedes. Specific biological features of M. curtipes at the northern periphery of its range include the absence of repeated breeding, completion of several developmental (age) stages within a short growing season, and long ontogeny involving several winterings.