Significance of indices of potential selection for residents of the USSR

Crow's indices of the opportunity for selection and their components connected with differential mortality (Im) and differential fertility (If) were estimated for populations of Soviet Union republics and for a number of USSR ethnic groups on the basis of demographic statistics. More than 10-fold decrease in the Im value was revealed in the total population of the USSR during 1926-1987. At present, the Im values in republics vary from 0.020 to 0.094 for urban population and from 0.030 to 0.121 in rural population, the ratio of perinatal mortality in the whole structure of prereproductive mortality being higher in the republics with lower values of the Im. The range of the If values for different peoples (0.148-0.643) is wider than for the populations of the republics (0.326-0.578). Interethnic differences contribute 47% of the variance in fertility. The structure of Crow's indices is given for urban and rural populations of the republics. Genetic implications of the data presented are discussed with respect to possible manifestation of the effects of inter-group selection.     

The two-sex multiethnic stable population model

A two-sex multiethnic stable population is a model with fixed mortality and fertility parameters that explicitly recognizes the behavior of males and females in at least two distinct ethnic groups. The presence of intergroup fertility may allow the different ethnic groups to grow at a constant rate in a population with a fixed sex-ethnic composition. The present paper considers a variety of rules for determining the ethnicity of intergroup births based on the ethnicities of the mother and father, and examines the mathematical models implied by those rules. Numerical examples are presented for a two-ethnic-group population in cases where intergroup births are shared equally by the two groups, are all considered members of one particular group, and are all members of the father's group. A special case of a more general model, where sons become members of the father's group and daughters become members of the mother's group, is also considered. The results suggest that when intergroup fertility is not uncommon, how ethnicity is determined can substantially influence the ethnic composition of the population.     

Rural-urban differentials in marital fertility in four Muslim populations

An analysis based on data collected as a part of the World Fertility Survey program in 4 Muslim populations Bangladesh, Java, Jordan and Pakistan does not show a consistent pattern in rural-urban differentials in marital fertility. While no significant diiferential in current fertility by place of current residence is noticeable in Bangladesh and Pakistan, urban women in Jordan showed lower fertility than their rural counterparts. Cumulative fertility, when controlled for duration of marriage, was found to be higher in urban than in rural areas of Bangladesh and Pakistan, but no clear pattern emerged in Jordan. In Java, both current and cumulative fertility were higher in urban than in rural areas; urban women who had spent their childhood and were brought up in the urban environment showed, in most instances, higher fertility than the other residence groups. (author's modified     

Marriage ethnic assortative mating of urban and rural population of Karachay-Cherkessia

This paper presents analysis of 28879 marriage records from 1990–2000 (total sample). Ethnic marriage assortative mating is positive in all ethnic groups significantly represented in Karachay-Cherkessia; the lowest values are characteristic of the more numerous ethnic groups (Karachays and Russians). The rate of metisation of the urban population is 21.6%; the rate for the rural population is 16%; the values vary significantly for different ethnic groups, reaching 98% for urban Ukrainians. With this rate of gene exchange, half of the urban population becomes interbred after three generations, and half of the rural population after four.     

Fertility and family planning in Papua New Guinea

This paper examines some of the data on fertility, family size and family planning from a survey conducted between November 1979 and March 1980 in 8 provinces both in rural and urban areas of Papua New Guinea (PNG). The sample consisted of 6283 male and female respondents; a total of 3986 females in the age group 15-49 and 2297 males between the ages of 20 and 54 were interviewed. About 9% of the rural and 5.4% of the urban female respondents were pregnant at the time of the interview. The higher number of pregnancies recorded for the rural population, compared to the urban, is due to longer duration of marriage and higher mean age. Both rural and urban respondents have similar attitudes to the ideal number of children. 4 and 6 children were indicated as an ideal number for the urban and rural population, respectively. The results indicate that economic pressures are being felt within the family in both urban and rural areas, and that the costs of raising children are clearly perceived, at least among the educated. Nonetheless, the majority of the population desires large numbers of children, the main reason being economic security in old age. It is also evident that the people have a negative attitude to modern methods of contraception because they are not well informed about them. The most frequently stated reason, the harmful effects on the health of the mother and future offspring, is probably one of the obstacles to their more widespread use. Though there is physical accessibility to family planning services for most urban and about 1/2 of the rural dwellers, the problems of non-use are mainly of a sociological and psychological nature. The problems include the attitude of husbands to their wives' use of contraceptives, reinforcement of culturally acceptable behavior by the extended family and community members, and the desire for more children. Although the levels of contraceptive awareness are relatively high, the overall impression is that the practice of modern contraception in both the rural and urban areas is low. Despite the rural-urban differences in educational and income levels, living conditions, and the availability of family planning services, awareness and current use are only slightly higher among the urban respondents. For family planning programs to have more impact in reducing the high fertility levels, a much more intensive program of activites is needed for the country at large.     

Meningococcal infection in the Uzbek SSR

The epidemiological characteristics of meningococcal infection in Uzbekistan during the period of 8 years since its last epidemic rise in 1972 is presented. Differences in the intensity of the epidemic process among the urban and rural population due to a considerable isolation of most of the rural populated localities from the district centers and the low population density in the republic have been established. The seasonal distribution of the infection had a winter-spring character in urban areas and a spring character in rural areas. 63.4% of all cases were children under 14 years. In cities a high morbidity level among adolescents and young people was determined mainly by visitors from rural areas. A high epidemiological importance of healthy carriers, predominantly schoolchildren and young people was established. The immunological studies of humoral immunity in different groups of the population indicate that the process of immunization was more rapid in cities.     

中国东北城乡植被物候时空变化及其对地表温度的响应

以中国东北地区的沈阳、长春、哈尔滨3个大城市及其周边的乡村为研究单元,在像元尺度上采用小波变换法对长时间序列中分辨率成像光谱仪(Moderate-resolution Imaging Spectroradiometer, MODIS)增强植被指数(Enhanced Vegetation Index, EVI)数据滤除噪声数据后重建平滑的EVI曲线,基于EVI曲线,采用动态阈值法提取出研究区2009—2016年植被关键物候期参数指标,即植被生长季开始时间(Start of Growing Season, SOS)和结束时间(End of Growing Season, EOS),分析各研究单元植被物候时空变化特征及其对地表温度的响应特征。结果表明:各研究单元SOS和EOS值的空间分布图存在明显的城乡差异。每一个像元所属的实际位置距离城区中心越近,其SOS值越小,EOS值越大,表明植被生长季开始日期早结束日期晚,整个植被生长期时间变长。各研究单元植被物候参数指标的年际变化趋势具有一定的相似性,即SOS随时间均呈现出提前趋势,且城区和乡村的SOS年际变化趋势保持一致,变化速率各不相同。研究区...     

Fertility and social class in a French village, 1901-75

Explanations of rural-urban fertility differentials have normally lain in assumptions about the traditionalist nature of rural, and especially agricultural, societies in contrast to the more rationalist and modern attitudes towards the family that exist in urban societies. This paper raises 2 objections to such an oversimplified view of rural-urban fertility differentials. The 1st is that rural fertility is assumed to have been relatively uncontrolled until the final stages of the demographic transition: the possibility of significant early control on fertility in rural areas is discounted. The 2nd is that this simplistic view of fertility differentials ignores the existence of social sub-groups within the rural population and assumes that all country-dwellers are members of an idealized rural society and behave, demographically, in a uniform fashion. The extent to which it is possible to recognize distinctive patterns of marriage and fertility within sub-groups of the rural population is examined by an analysis of the fertility experience of 294 females who lived in a single village in southern Normandy at some period between 1901 and 1975. Biographical details were obtained from an exhaustive analysis of census lists and the civil registration documents to attempt a family and household reconstitution. Other sources used include electoral registers and land-ownership records. The pattern of evolution of fertility in the village for the period considered is derived using Coale's demographic indices: indices of female proportions married, marital fertility, illegitmate fertility and overall fertility are derived by standardizing the population under study against the age-specific fertility schedules of a population believed to have natural fertiltity (the American Hutterites). Overall fertility has increased slightly through the 75-year period, being notably low at the star of the century, chiefly as a result of the high average age at 1st marrige of girls from owner-oc pying farm families. Changes in overall fertility through the century have partly resulted from changes in the proportionate contribution of the different sub-classes of the village as a whole, but the increased importance of owner-occupying farm households has been compensated by a similar increase in the importance of employees in nonagricultural activities who have the highest fertility levels of all. The explanations of these differentials in fertility between sub-classes of the local population appear to lie in the relationships of those classes to the labor market, and in the degree to which capital accumulation and inheritance act as a brake on early marriage and fertility within marriage.     

Fox Squirrel Survival in Urban and Rural Environments

Abstract A number of studies on mammalian species that have adapted to urban areas suggest survival may be higher for urban populations than rural populations. We examined differences in fatalities between an urban and rural population of fox squirrels (Sciurus niger). We radiocollared (n = 50 rural, n = 78 urban) fox squirrels during approximately 2 years. We found monthly survival of rural fox squirrels (Ŝ = 0.936) was lower than urban fox squirrels (Ŝ = 0.976) over the same 12-month period. Nonetheless, when comparing a 24-month period of survival data on urban squirrels with an 18-month period on the rural squirrels (periods overlapped for 12 months), survival rates were more similar between urban (Ŝ = 0.938) and rural squirrels (Ŝ = 0.945). Our data suggest that sex and season may influence survival of urban squirrels and not rural squirrels. We also found that cause of fatalities differed between the urban and rural squirrels, with >60% of fatalities on the rural site caused by predation. In contrast, <5% of the fatalities on the urban site were caused by predation and >60% of urban fox squirrel fatalities were caused by motor vehicle collisions. This study illustrates the need to advance our ability to understand, predict, and mitigate effects of urbanization on wildlife resources.     

Consanguinity in Spain: socioeconomic,demographic, and geographic influences

Information on consanguinity in Spain was reanalyzed in order to obtain a more complete picture of consanguinity patterns by considering temporal, geographical, demographic, and economic factors. To obtain data on consanguineous marriages, we reviewed 106 published references. Only populations with homogeneous geographical characteristics, economic activities, transportation facilities, and the like, were considered. Two-way analysis of variance (ANOVA) provided highly significant differences (p < 0.001) for a both for time periods and for urban versus rural patterns, but there was no interaction between the latter two. A regression analysis shows that for rural areas the geographic characteristics, economy, communications, and index of demographic tendency were significant predictors of the inbreeding coefficient. The results obtained indicate that urban and rural patterns differ significantly and that the temporal factor needs to be taken into account before comparing inbreeding coefficients. In urban areas the census size and altitude are included in the regression equation as significant variables, but association was not found between alpha and the index of demographic tendency (population increase or decrease). Instead, the absolute number of inhabitants (census size) was significant. In rural areas geographic characteristics, communications, and index of demographic tendency were significant predictors of the inbreeding coefficient.     

Recent trends and components of change in fertility in Nepal

The objectives of this article are, first, to provide improved estimates of recent fertility levels and trends in Nepal and, second, to analyse the components of fertility change. The analysis is based on data from Nepal's 1996 and 2001 Demographic and Health Surveys. Total fertility rates (TFR) are derived by the own-children method. They incorporate additional adjustments to compensate for displacement of births, and they are compared with estimates derived by the birth-history method. Fertility is estimated not only for the whole country but also by urban/rural residence and by woman's education. The own-children estimates for the whole country indicate that the TFR declined from 4.96 to 4.69 births per woman between the 3-year period preceding the 1996 survey and the 3-year period preceding the 2001 survey. About three-quarters of the decline stems from reductions in age-specific marital fertility rates and about one-quarter from changes in age-specific proportions currently married. Further decomposition of the decline in marital fertility, as measured by births per currently married woman during the 5-year period before each survey, indicates that almost half of the decline in marital fertility is accounted for by changes in population composition by ecological region, development region, urban/rural residence, education, age at first cohabitation with husband, time elapsed since first cohabitation, number of living children at the start of the 5-year period and media exposure. With these variables controlled, another one-third of the decline is accounted for by increase in the proportion sterilized at the start of the 5-year period before each survey.     

Socio-economic transition, inequality, and mortality in Lithuania.

The study assessed inequalities in mortality of Lithuanian urban and rural populations throughout the period of socio-economic transition (1990-2000). Mortality from major causes of death, except cancers in females, was higher among the rural population. Inequality in mortality increased during the period of transition, especially among males, mainly due to more rapidly improving health of the urban population. Cardiovascular diseases and external causes made the largest contribution to the inequality. Differences in mortality of urban and rural populations point to greater social and psychological stress affecting the rural population, unhealthy life styles, inequities in accessibility of health care and lack of preventive programs in rural areas.     

Urban-rural differences in the relationship between women's employment and fertility: a preliminary study

A statistical study of data from the Egyptian census for 1960 points up the influence of the employment of women on their fertility. Results show that the child/woman ratio rises with the level of female employment in the rural areas, but falls as the level of employment rises in the urban areas. Subject to confirmation by more detailed methods, it seems that, in urban areas, provision of opportunities for women to work is of major importance in attempting to reduce national fertility levels, but this will have the opposite effect to what is intended in rural areas. Rural and urban fertility levels appear to be similar at a low level of economic activity; however, when this economic activity surpasses 10%, a noticeable fertility differential appears. Industrial or commercial work opportunities change a woman's pattern of living, and are essential to the permanent lowering of fertility to replacement levels.     

Analysis of the sociodemography of gonorrhoea in Leeds, 1989-93.

OBJECTIVE: To investigate the epidemiology of gonorrhoea in an urban area in the United Kingdom. DESIGN: Analysis of all cases of gonorrhoea with regard to age, sex, ethnic group, and socioeconomic group with 1991 census data as a denominator. SETTING: Leeds, a comparatively large urban area (population around 700,000) in the United Kingdom. SUBJECTS: All residents of Leeds with culture proved cases of gonorrhoea during 1989-95. MAIN OUTCOME MEASURE: Relative risk of gonorrhoea. RESULTS: Sex, age, race, and socioeconomic group and area of residence were all independently predictive of risk of infection. Young black men aged 20-29 were at highest risk, with incidences of 3-4% per year. Black subjects were 10 times more likely than white subjects to acquire infection, and subjects from the most deprived socioeconomic areas were more than four times more likely than those from the most affluent areas to acquire infection. CONCLUSIONS: Different ethnic and socioeconomic groups vary in their risk of infection with gonorrhoea within an urban area. Targeted interventions and screening to reduce the incidence of sexually transmitted disease are now priorities.     

Immunization interview survey in the Mongolian People's Republic.

An immunization interview survey was carried out in the urban and rural areas of Mongolia. The population sample interrogated comprised 1359 households with 6994 household members, 3634 of them younger than 15 years. The data collection unit was a private household, where information on administrative, demographic and socio-economic items was obtained in addition to detailed information on vaccination histories. A fair number of individuals with a positive history was found among children aged 1 to 5 years; the highest rates were determined among preschool and school-children aged 5 to 9. Significant differences in vaccination rates were found between urban and rural dwellers, urban areas displaying a higher proportion of vaccinated children in the younger age groups and rural areas among school-age children. A significantly higher proportion of vaccinated individuals was found among children living in somons than those living in aimac centres. No significant differences were found between children attending child collective institutions and those educated solely at home. The immunization interview survey was specially directed toward obtaining an estimate of the vaccinated population segment with reference to age in demarcated areas and thus detecting "weak spots" requiring remedial action.     

The image of environment and mental maps in rural areas: The case of a kibbutz in Israel

Summary At the outset of this article I raised two questions. (1) Is the cultural homogeneity of the kibbitz reflected in its mental maps? (2) Are there differences between the rural and urban perceptions of environment? Two main conclusions can be drawn: (1) Despite a high degree of sociocultural homogeneity, two distinct conceptions of the term environment exist; the differences are in the scope of the area and in the number of elements recorded and are rooted in the age groups and in the personal range of activity of the interviewee. (2) The perception of elements in the rural environment does differ from that of the urban areas: cognition of the environment of the rural population is built around nodes and districts, while that of the urban population is built around paths and landmarks. The explanation of this difference is rooted in the different landscapes and in the individual's different personal activity within that landscape.     

Genetic demographic study of Shors in Tashtagolskiĭ district of the Kemerovo region: changes in the marriage migration structure

The changes in the marriage structure with respect to the age at marriage, ethnicity, and spouses' birthplaces during the period of time corresponding to two generations have been analyzed in the rural population of Shors of Tashtagolskii raion of Kemerovo oblast. In general, the Shor population had a high assortative marriage rate with respect to these parameters in the period studied, although there was a temporary tendency towards its decrease. The ages of marriage for both the male and the female Shor populations in the years 2000-2005 were significantly older than in 1940-1945 and 1970-1975. The age-assortative marriage rate was r = = 0.60 in 1940-1945, r = 0.73 in 1970-1975, and r = 0.66 in 2000-2005. The birthplace-assortative marriage rate decreased from 79.63% in 1970-1975 to 70.64% in 2000-2005. The ethnic assortative marriage rate of Shors steadily decreased during the time interval studied; it was 96.92, 89.95, and 80.98% in 1940-1945, 1970-1975, and 2000-2005, respectively, for the total rural population of Tashtagolskii raion.     

城市化过程中北京市人口时空演变对生态系统质量的影响

应用第五、第六次人口普查和MODIS-NDVI遥感数据,从城市、区/县和街道/乡镇3个尺度,分析了2000—2010年北京市人口时空演变特征及其对区域生态系统质量的影响.结果表明: 研究期间,北京市总人口增长了43.9%,人口空间分布形成了明显的圈层特征,呈现向近郊转移聚集的趋势;北京市的年最大归一化植被指数(NDVI)呈增加趋势,在5～6环之间却显著降低.城区和远郊区的NDVI变化趋势与人口密度变化率呈显著负相关.城市化带来的人口数量增加不仅没有导致北京整体生态系统质量下降,反而通过城市功能调整和农民进城务工人口转移等方式,提高了城区和远郊区的生态系统质量.不同的功能定位和发展机制是影响北京市人口时空格局变化及其生态影响的主要原因.     

Variation of natural reproduction parameters and Crow’s indices in different ethnic groups in the two largest megacities of Russia

Genetic-demographic parameters of natural reproduction in the most numerous ethnic groups of Moscow and St. Petersburg were assessed on the basis of the 2002 All-Russia Population Census data and other sources. The intensity of intragroup selection due to individual differences in fertility in the cohorts of women born in the 1930s–1950s decreased in all ethnic groups studied. It was concluded that, in both megacities, the relaxation of the selection component due to differential fertility almost stopped: the values of the Crow’s index I_f stabilized at 0.3 < I_f < 0.4, which was associated with relative stabilization of the interfamily variance of fertility. The temporal dynamics of the intensity of intergroup selection due to interethnic differences in fertility rates was more complex. It was only recently that this type of selection came into action, since even at the beginning of the 20th century fertility rates in various ethno-territorial and ethno-confessional groups of the population of the Russian Empire were similar (5–6 offspring per marriage). In the subsequent decades, interethnic differentiation in progeny size increased because the reproductive behavior of different population groups underwent “modernization” with uneven speed. In Moscow and St. Petersburg, the intensity of intergroup selection decreased in women birth cohorts of the 1930s–1950s, while it was an order of magnitude lower than the intragroup selection. Currently, the average number of offspring varies among ethnic groups in a narrow range from 1.3 to 1.6. It can be expected that interethnic differences in fertility rates in these megacities will increase again owing to growing numbers of migrants from regions with traditionally high birth rates, resulting in differential natural growth of ethnic groups and the corresponding dynamics of the gene pool of the population.