A comparative study of determinants of uxorilocal marriage in two counties of China

A strictly maintained patrilineal family system makes virilocal marriage almost universal and uxorilocal marriage rare in the history of rural China. Uxorilocal marriage can be divided into two types that may be termed, respectively, contingent and institutional. The former preserves family lineages in families without a son and occurs when uxorilocal marriage is uncommon. The latter serves practical economic purposes in families with sons and occurs when uxorilocal marriage is relatively prevalent. Using data from a survey in two counties of Shaanxi--Lueyang, where both kinds of uxorilocal marriage are prevalent, and Sanyuan, where uxorilocal marriage is rare and usually contingent--this paper employs logistic regression models in a quantitative comparative study of determinants of uxorilocal marriage in rural China. We show that the purposes and prevalence of the two types of uxorilocal marriage differ and that their determinants are also different in the two counties. In Sanyuan, the determinants are only a couple's sibling composition, membership in a large family clan, and educational level. In Lueyang, in addition to those determinants in Sanyuan, important contributions to the type of uxorilocal marriage include a couple's parental marriage type, age at marriage, adoption status, marriage arrangement, and their attitudes toward uxorilocal marriage. The results indicate the potential importance of encouraging uxorilocal marriage in rural areas as a means of mitigating demographic and social problems related to son preference, such as high sex ratio at birth and lack of old-age security, which are projected for China's future.     

Marriage form and age at first marriage: a comparative study in three counties in contemporary rural China

Using data from two surveys in three counties in which the prevalence of uxorilocal marriage differs greatly, this article analyzes the effects of marriage form, individual, family, and social factors on age at first marriage and spousal age difference. The results show that, under the Chinese patrilineal joint family system, compared with the dominant virilocal marriage form, uxorilocal marriage significantly lowers women's age at first marriage, increases men's age at first marriage, and consequently increases spousal age difference. Education, number of brothers, adoption status, marriage arrangement, and marriage circle also significantly affect age at first marriage for both genders. Age at first marriage and spousal age difference vary greatly among the three counties. These findings address the process and consequences of change in rural family and marriage customs during the current demographic and social transition and may help to promote later marriage and later childbearing under the present low fertility conditions in rural China.     

A comparative study of two community-based conservation models in Nepal

Conservation areas (CAs) and community forests (CFs) are generally considered to be two successful community-based conservation (CBC) models in Nepal. Nepal’s two CAs are administered by a nongovernmental organization (NGO), and all of its CFs are administered by a government agency (GA). The goal of this research is to compare and contrast these two models using quantitative and qualitative data collected through field research in the Annapurna Conservation Area in the summer of 2007 and adjacent CFs in the fall of 2008. The Conservation Area Management Committee (CAMC) and the Community Forest User Committee (CFUC) are the functional decision-making entities at the local level in CAs and CFs, respectively. We conducted one-on-one semi-structured interviews with 66 executive members of 10 CAMCs and 67 members of 9 CFUCs. While both models appear to have performed well overall, the CA under the direction of the NGO appears to have fared better with regard to (i) developing trust of local constituencies, (ii) garnering favorable attitudes among villagers, (iii) building capacity of executive members, and (iv) improving standards of living. We suggest that the particular accountabilities associated with NGOs may situate them in a better position to cultivate local governance than state entities on their own.     

A comparative study of winter survival in two temperate Collembola

ABSTRACT.

• 1 We studied winter survival of two temperate collembolan species, Orchesella cincta (L.) and Tomocerus minor (Lubbock), that overwinter in adult and juvenile life stages.
• 2 A significant seasonal variation in cold hardiness, measured as lethal temperature after 24 h exposure, was found for both species. There was no difference between juveniles and adults in cold hardiness. O.cincta was more cold tolerant than T.minor.
• 3 A group of high and a group of low values for lethal temperatures could be distinguished.
• 4 Frost periods induced gut evacuation in O.cincta, but not in T.minor.
• 5 During frost periods no extra winter mortality was found in T.minor. This species moved down the soil profile as a response to a frost period without snow cover.
• 6 The winter mortality of O.cincta was difficult to estimate, since part of the population remained above ground in trees and escaped from sampling. The smallest size classes, which are restricted to the litter, had a lower winter mortality than T.minor.

     

Fertility and population policy in two counties in China 1980-1991

A survey of women in two highly developed rural counties of China, Sichuan and Jiangsu Provinces, was carried out in late 1991, to gain information about demographic and economic change between 1980 and 1990. Three separate surveys were conducted: the first a questionnaire administered to married women aged 30-39, eliciting information about childbearing and contraception, as well as the social and economic background of the respondents; the second, focus group interviews emphasizing the motivation for childbearing. Official information about the selected villages, townships and counties was also collected. National level data in 1987 show that individual reproductive behaviour in China failed to conform to a universal, effectively implemented, population policy. They imply either a spatial range of policies, or great diversity in the demand for children, or perhaps a combination of both. Such diversity in reproductive behaviour is also found in the study area. The purpose of the analysis was to examine the diversity in reproductive behaviour and contraceptive practice, and to discover whether differentials are influenced by area, or else exist between individuals within areas. If the former, then the explanation may be found in differences in policy formulation and implementation between areas: and if the latter, to demand for children, or else differential application of policy restrictions. The main findings were that: (1) the explanation of the pattern of fertility and contraceptive use is to be found at the individual level (within locations) rather than in policy differences between administrative units; (2) the association between income and number of children is negative, as is that between income and the propensity for uniparous women to remain unsterilized. The theory that privilege may be exercised to gain concessions from birth planning cadres is therefore not supported; (3) ideal family size differentials are largely absent, showing that social (education) and economic (income, occupation) characteristics are not responsible for differences in reproductive motivations, and implying that the nature of the demand for children is very different from that in most rural areas of the Third World; (4) data on ideal family size by sex of the existing offspring indicate only a weak preference for sons. The low demand for children, and the weak son preference, may both be explained by the social acceptability of uxorilocal marriages, and of village endogamy, together with the prohibitive costs of children, and especially of sons. This partly results from the expense of education, but most mothers emphasize marriage costs. It is speculated that the circumstances responsible for the escalating costs of children in the two countries are likely to pertain in growing areas of the country, with the privatization of education and health services, the declining support of collective institutions, and the replacement of this function by kinship networks. These on-going changes imply that any policy of reproductive restriction for the purposes of population control is likely soon to meet with diminishing resistance; and it may later be rendered unnecessary in the eyes of government officials, as fulfilled reproductive intentions lead to a fertility level below replacement level.     

Socioeconomic determinants of age at first marriage in Bangladesh

Using data from the 1976 Bangladesh Fertility Survey, multiple classification analysis was used to evaluate the effect of socioeconomic factors on age at 1st marriage. The independent variables considered were education, childhood and current residence, religion, work status before marriage, and husband's childhood residence, education, and occupation. Analysis was carried out for the total sample as well as for 3 birth cohorts of approximately equal size: 1) those born before 1940, 2) those born between 1940-50, and 3) those born after 1950. Of all the included variables, women's education has the strongest influence on the variation of age at 1st marriage. For all ever-married women, the mean age at marriage for women with primary education is 13.4 years, 0.9 years higher than for women with no education (12.5 years), and 1.2 years lower than for women with a high school education or beyond (14.6 years). Difference in means for cohorts indicate a gradually increasing influence of education on people's decision in marriage. Husband's education does not appear to be as important. Childhood residence has, directly and indirectly, a strong influence in marriage age. Among other factors, women's premarital work participation, as well as region and husband's occupation, are important. Since women's education, childhood residence, and work participation are the strongest socioeconomic variables affecting marriage age, the modernizing influences of education, urbanization, and female work participation should have an effect on the marriage pattern; this effect is consistent with that observed in other societies.     

两种模式生物核小体定位比较研究

在对两种模式生物酵母与果蝇胚胎期核小体定位进行研究时,发现不同物种间以及同一物种中不同表达模式基因上的核小体分布呈现出差显著异性。在总体上,转录起始位点附近的酵母核小体NFR区域比果蝇的NFR短。经基因中心对齐后,酵母与果蝇胚胎期沉默型基因的核小体缺失区域的两个边界中间处共同呈现了一个明确有着均匀间隔的核小体数n,且随着基因长度L的变长其周期性特性逐渐变模糊,但果蝇的图谱表现的更为复杂。结果表明,从单细胞酵母生物到多细胞果蝇生物间基因组的进化过程中,核小体组织的演化既有变异性,也具有保守性。     

Secular trend in age at menarche in China: a case study of two rural counties in Anhui Province.

There is increasing evidence that age at menarche has decreased in Europe and the United States during the last century and in Japan over the last several decades. Data from a community-based survey conducted in two rural counties of Anhui Province in China indicate a similar, downward secular trend in age at menarche for Chinese women. The present study shows the mean age at menarche decreased by 2.8 years, from 16.5 to 13.7, over an approximate 40-year time interval. This rapid decrease in age at menarche may partly be due to better nutrition and living standards reflected by the improved socioeconomic standards experienced in China over the past few decades. To test this hypothesis, a number of determinants of age at menarche were assessed; year of birth, literacy status, county of residence, amount of physical labour, general health status, pesticide exposure before age at menarche, and drinking water source were all found to be associated with age at menarche.     

A comparative study of pheromone perception in two species of Noctuid moths

The electrical activity of single olfactory receptor neurons in male soybean looper (SBL) Pseudoplusia includens(Walker) and cabbage looper (CL) Trihoplusia ni(Hübner) moths was evaluated in response to stimulation with fixed amounts of the individual components of their respective pheromone blends. In common with earlier observations in the CL, there are at least two classes of morphologically distinct pheromone sensitive sensilla on the antenna of male SBL, each of which contains two olfactory receptor neurons. In both species, one class of sensilla contains an olfactory receptor neuron sensitive to (Z)-7-dodecen-1-ol acetate (Z-7, 12:AC), the major component in each insect's blend, and a companion receptor neuron which is sensitive to (Z)-7-dodecen-1-ol (Z7,12: OH). In both species the second class of sensilla contains an olfactory receptor neuron which is sensitive to one of the minor components of the pheromone blend. (Z)-5-dodecen-1-ol acetate (Z-5,12:AC) is an effective stimulus in SBL, whereas (Z)-7-tetradecen-1-ol acetate (Z-7,14:AC) is an effective stimulus in CL. However, these two stimulatory compounds have been identified only in the female CL gland; neither has been found in the SBL gland. Thus, in contrast to the CL, which has receptor neurons which are responsive exclusively to conspecific pheromone components, the SBL has a class of receptor neurons which is responsive to a minor component of another species' pheromone blend. Field-trapping assays in which Z-5,12:AC is added to the SBL blend suggest that this single CL component is a powerful inhibitor of male SBL behavioral responses to conspecific pheromone blends. The difference observed in the specificity of the receptor neurons in this second class of sensilla are thus believed to play an integral role in the isolation processes that are maintained between these two species and may well account for the observed behavioral differences in their responses to heterospecific pheromone blends.     

A comparative study of the parasites in two populations of white-tailed deer

The study compares parasite prevalence in two geographically separated populations of white-tailed deer in central Pennsylvania. Differences in prevalence were found for certain of the parasites studied. Characteristics of curves comparing prevalence with host-age group, however, were remarkably similar for individual parasites from both populations. Prevalence increased with host age for certain species of parasite and decreased or remained constant for others. Some of the underlying biological properties of the infections which may be responsible for the characteristics of the age specific prevalence curves are discussed.     

A comparative study of growth strategies in two varieties of Arrhenatherum elatius

Growth strategies of the two varieties of Arrhenatherum elatius were studied. The two varieties studied were: onion couch, which produces bulbous swollen internodes and is an arable weed of local importance, whilst tall oat-grass is more widely distributed. An experiment in which the two varieties were grown at different densities in monoculture and were harvested at intervals, highlighted various aspects of the competitive relation between the two varieties and an annual crop. Significant and consistent differences were found between the two varieties for most of the attributes measured during the two growing seasons. Tall oat-grass allocated a greater proportion of its whole shoot dry weight to producing vigorous aerial tillers, whereas onion couch allocated a greater proportion of its whole shoot dry weight to the development of basal internodes. The regulation of tiller number as a reaction to increasing density in tall oat-grass is achieved by high tiller mortality, whereas in onion couch, this stress is expressed by small tiller mortality. Growth pattern shown by the two varieties of A. elatius reflect the adaptive strategies evolved by them in two different habitats and are due to the genetic factors which determine the presence or absence of their characteristic basal internodes.     

A comparative study of two goby shrimp associations in the Caribbean Sea

In Curacao (Netherland Antilles, Caribbean Sea), two species of gobies, Nes longus (N. longus) (Nichols 1914) and Ctenogobius saepepallens (C. saepepallens) (Gilbert & Randall 1968) with their associated shrimp Alpheus floridanus (A. floridanus) (Kingsley 1878) were observed. Data were collected on feeding behaviour, distances from their burrows, and interactions among conspecifics. Results confirm that the partnership of C. saepepallens and its shrimp is facultative, but show differences to former observations. Possible reasons for this are discussed.     

A comparative study of migratory behaviour and body mass as determinants of moult duration in passerines

Birds moult to maintain plumage function through life, but the factors that determine moult duration are poorly understood. In temperate areas, variation in moult duration could be largely associated with between-species differences in migratory behaviour (migrants have less time for moulting after breeding), and body mass (because the aerodynamic cost of rapid moult increases allometrically with body size). Moreover, if the energetic cost of transport favours a smaller body size in migratory species, then the effects of migratory behaviour and body mass on moult duration could be confounded. We conducted a comparative study of the duration of adult complete moult in 48 European passerine species, in relation to body mass and migratory behaviour (sedentary, short-distance migrants and long-distance migrants). Lighter and more migratory species moulted faster than heavier and more sedentary species, but migration was not associated with body mass. If accelerated moult compromises the success of migration, changes in the physiology or phenology of moult in migratory birds are better interpreted as adaptive responses to compensate for such costs.     

Age at first marriage in Nepal: differentials and determinants

The aim of this paper is to investigate the differentials and determinants of female age at first marriage in rural Nepal. The life table technique was employed to calculate median age at marriage. The proportional hazard model was used to study the effect of various socioeconomic variables, and to identify the magnitude and significance of their effects on the timing of first marriage. The data were taken from a sample survey of Palpa and Rupandehi districts in rural Nepal. Both married and unmarried females of marriageable age were included in the survey. Median age at marriage was about 17 years for data from only married females, whereas it was about 18 years for data from married as well as unmarried females of marriageable age. Median age at marriage was about 16 years for uneducated females and 19 years for females educated up to intermediate or higher level. The analysis underestimates the median age at marriage for married females, probably due to right censoring. The risk of getting married early decreased gradually with increasing year-of-birth cohort. The risk of early marriage was higher among females of high socioeconomic status compared with those of low socioeconomic status. Females engaged in service married earlier than those engaged in household work. High socioeconomic status families are motivated, for religious and prestige reasons, to get their daughters married at an early age, preferably before menarche. Thus, education, occupation and age at menarche are the most powerful factors in deciding the timing of first marriage in Nepal.     

A comparative study of the phytochemistry of two African Rain Forests

A comparative analysis of aspects of the secondary chemistry of plants from the Kibale Forest, Uganda, and the Douala-Edea Forest Reserve, Cameroon (93 species in all) has shown mean concentrations of tannins and other phenolics to be significantly greater in both young and mature foliage from Douala-Edea than in comparable taxa from Kibale. The differences remain significant when analysis was restricted to common species only. Chromatographic analysis confirmed that the proportion of species from Douala-Edea yielding tannin breakdown products was significantly greater than that from Kibale. In contrast, the proportion of species whose leaves gave definite alkaloid-positive Dragendorff reactions was significantly higher in the Kibale site. Within each site, mature leaves of the great majority of species yielded either tannins or alkaloids but the presence of detectable quantities of both types of compound was rare. In each site distributions of the two classes relative to one another departed significantly from independence at the O < 0.005 level. Nutrient analyses of vegetation also showed striking differences between the two sites; the Ugandan material appearing to be more nutrient-rich. The distribution patterns of nutrients and of secondary metabolites between the two sites are discussed in relation to current hypotheses concerning strategies of defence chemistry among plant communities. The data suggest that in Douala-Edea, which is characterized by very sandy and acid soils, the common elements of the flora invest heavily in the production of high concentrations of tannins and other phenolics. According to current hypotheses, these are the class of secondary compounds whose characteristics are most suitable to defence of vegetation growing on poor soils, and/or in species-poor stands, and in which leaves are likely to be long-lived.     

A comparative study of two RNase isozyme activities inNicotiana glutinosa leaves

Effects of some chemicals on the activities of two ribonuclease isozymes, M and F, in the leaves ofNicotiana glutinosa were investigated. CHX and AMD suppressed the increase of M isozyme activity induced with mock-inoculation. On the other hand, CHX suppressed slightly the increase of F izozyme activity induced with TMV-inoculation, but AMD and 5-FU stimulated it.     

A comparative study of metal levels in plants from two contrasting lead-mine sites

Summary An investigation into the levels of metals in plants growing on metalliferous soils was carried out. The exchangeable metal concentration of soils from Tyndrum and Trelogan was found to be extremely variable from sample to sample and the influence of soil pH on the exchangeable lead and zinc concentration is discussed. Large differences in heavy metal levels were found between species and may be indicative of different mechanisms of tolerance to lead and zinc excess. Large differences in calcium levels between plant tissues were also found. These may result from the use of calcium in ameliorating lead and zinc toxicity in some species.     

Social determinants of health--a comparative study of Bosnian adolescents in different cultural contexts

This study investigated the effects of sociocultural contexts on health and the psychological well-being of immigrant adolescents, aged 15 to 18 years, originally from Bosnia and Herzegovina and now living as displaced persons either in Bosnia, or immigrants in Croatia and Austria. The study addresses the social determinants of health with a specific focus on five factors in the social environment that might have an influence on health status: gender, socio-economic status (SES), perceived discrimination and exposure to violence, social support and religious commitment. Dependent variables included self-rated health, a count of self-reported objective health problems and a range of indices of psychological well-being (somatic stress, anxiety, depression and self-esteem). The purpose of the study was to examine whether social risk factors have an effect on health, which factors mediate these effects on self-rated health and to assess whether these effects differ by gender Results indicate that perceived discrimination and violence are related to poor health through psychological stress as a major mechanism with stronger effects for girls in the study. Differences across the three socio-cultural contexts reveal the complexity and specificity of the relationships between analyzed factors as the association between discrimination and health was attenuated for some groups due to the protective resources of immigrants.