Effect of famine on fertility in a rural area of Bangladesh

Data on household socioeconomic status collected in the 1974 census and registration data on births, deaths, and migrations for the 1974-77 period from the Demographic Surveillance System of the International Centre for Diarrheal Disease Research, Bangladesh, were used to investigate the effects of the 1974-75 famine on differential fertility in a rural population of Bangladesh. Occupation of household head was used as a measure of socioeconomic status. Overall, fertility declined by 34% over the 1975-76 period and increased by 17% in 1976-77 from the 1974-75 figure. Significantly lower fertility was observed in 1975-76, irrespective of socioeconomic status, but the lower socioeconomic groups were affected more than the higher groups. Post-famine fertility was significantly higher only in the 2 middle occupation categories. The age-specific fertility rates suggest that the famine affected all age groups. The post-famine fertility was higher than that of 1974-75 in all but those aged below 20. At age 40 and over the recovery was slight. Husband-wife separation showed an increase during the famine and particularly among the lower socioeconomic groups. The males of the lower socioeconomic households migrated to other regions to obtain food for the family, thus affecting frequency of coitus. The decline in fertility may be due to several factors: deferred marriage; increase in divorces and husband-wife separations; high fetal wastage; voluntary fertility control through contraception, abstention, or induced abortion; and infecundability. An indirect measure of marriage rate indicated that fewer couples entered into marriage in 1974-75, particularly in the lower socioeconomic groups. Both the higher and lower socioeconomic groups were affected by the famine but the precise mechanisms were not the same. At this stage, it is not feasible to estimate the contribution of each factor to the fertility decline. The lower socioeconomic groups were more affected by husband-wife separations and deferred marriages; the higher socioeconomic groups were affected by mental stress and anxiety.     

Forecasting barley mildew development in West Scotland

Observations on plots of spring barley cv. Golden Promise during May-July 1973–79 showed that escalation of mildew commenced in mid-June 1976, in late June in 1973 and 1974, in early July in 1978 and 1979, and failed to develop in 1975 and 1977. By mid-July there was 40% infection in 1976, and 13–21% infection in 1973, 1974, 1978 and 1979. Less than 2% mildew occurred in 1975 and 1977. Using as a basis the method of mildew forecasting formulated by Polley & King (1973), it was found that once mildew was established in the crop there was moderately good association between the incidence of high mildew risk according to the Polley weather criteria and the major peaks of spore concentration above the crops. It was not possible to correlate these two features during May and early June each year because of a lack of inoculum, but it is considered that the failure of mildew to develop during the entire growing seasons of 1975 and 1977, in spite of frequent high risk periods, was due in part to low atmospheric humidity during the early part of the season. The relative number of accumulated Polley factors satisfied on days when the relative humidity approx. 1 m above ground was 78% or more (at 0900 GMT) during the period mid-May to mid-June, separated the low mildew years of 1975 and 1977 from the moderate ones of 1973, 1974, 1978 and 1979, and the severe mildew year of 1976. This procedure may provide a practical means of forecasting the level of mildew build-up during the later growth stages of the barley crop.     

Socioeconomic determinants of fertility: selected Mexican regions, 1976-1977

Cumulative fertility is analyzed for 4 regions of Mexico, based on World Fertility Survey data of 1976-77; the state of Baja California, the Northwest region, the State of Jalisco, and the Northeast region. Based on stepwise regression methodology, the study compares results for 12 subsamples of married respondents, 3 age categories by 4 regions. The dependent variables are children ever born and children ever born in the last 5 years. Migration, urban, educational, and occupational variables are included as independent variables. Regression results reveal level of education is the major, and negative, influence on fertility. Other results include specific negative effects for prior occupation, size of place of residence, and childhood place of residence. Fertility effects appear different for migration origin and destination regions, but more similar for younger ages. Effects of migration on fertility are small. Mean fertility as measured by children ever born was 4.34 for the 1976-77 World Fertility Survey samples versus 3.69 for the Mexican census of 1980. Fertility varied somewhat by region with the highest and lowest values in Jalisco and the Northeast, respectively. Expected age-related changes in fertility were noted.     

Household extension and reproductive behaviour in Taiwan

The inflence of household type on reproductive behavior is examined for a national probability sample of Taiwanese women. Data were derived from a 1980 national household survey of the labor force in Taiwan, focusing on 10,624 couples. Reproductive variables include measures of current and prospective fertility as well as cumulative fertility. In spite of remarkable social and economic development over the past 3 decades, extended families are still widely found in Taiwan. Women in extended households have only slightly higher fertility preferences and current fertility than women in nuclear families once marital duration is controlled. Although women in extended households marry earlier and receive more family help with child care than women in nuclear families, such factors are no longer considered sufficient to produce major differentials in reproductive behavior. Residence and husband's class of work are the strongest correlates of whether a household is currently extended or nuclear. In general, the husband's characteristics are more strongly related to family type than the wife's. Findings suggest that preferences for smaller families and low fertility need not await a transformation to a nuclear family structue.     

Differentials of fertility between polygynous and monogamous marriages in rural Bangladesh

This paper discusses polygynous marriages in rural Bangladesh, using marital status and birth registration data from the Demographic Surveillance System (DSS) of the International Center for Diarrheal Disease Research, for the period 1975-79. Of all the marriages recorded during this period about 5% were polygynous. To identify the women polygynously married, 1974 census data of the DSS area were used. The difference in age at marriage between the polygynous groom and his subsequent wife was 15 years on average. The socioeconomic indicators studied were education, occupation and area of dwelling space. In general, these indicators between women in monogamous marriages were significantly higher than between the women in polygynous unions. During the period 1976-79, 863 polygynous marriages were recorded (4.9% of all marriages in the study area). Polygynous marriages were found to be less frequent among men with 2ndary and higher levels of education. The highest proportion of polygynous marriages occurred among husbands with no schooling or Koranic education. The general fertility rate of women in monogamous marriages was significantly higher than for women in polygynous marriages, overall and in all age groups except 20-24. During the period 1975-79, the mean number of liveborn children for monogamous women was higher than that of polygynous women.     

Socioeconomic determinants of fertility: Selected Mexican regions, 1976–1977

Abstract

Cumulative fertility is analyzed for four regions of Mexico, based on World Fertility Survey data of 1976–77: the State of Baja California, the Northwest region, the State of Jalisco, and the Northeast region. Based on stepwise regression methodology, the study compares results for twelve subsamples of married respondents, three age categories by four regions. The dependent variables are children ever born and children ever bom in the last five years. Migration, urban, educational, and occupational variables are included as independent variables. Regression results reveal level of education is the major, and negative, influence on fertility. Other results include specific negative effects for prior occupation, size of place of residence, and childhood place of residence. Fertility effects appear different for migration origin and destination regions, but more similar for younger ages. Effects of migration on fertility are small.     

Interspecific dominance amongst three species of coarse fish in Slapton Ley, Devon

Marked changes in the relative numbers of roach Rutilus rulilus (L.), rudd Scardinius erylhroplhalmus (L.) and perch Perca fIuviatilis L. , in Slapton Ley, Devon, have been observed over the period 1967–1978. Historically, the lake had been dominated by rudd and perch; significant numbers of roach were not thought to be present until 1967. From then onwards the roach population exhibited a considerable expansion, apparently replacing the rudd, which had virtually disappeared by 1974. In 1975 extensive mortalities of roach were caused by the pseudophyllidean cestode Ligula intestinalis L. During 1976 and 1977 larger number of rudd, belonging to the 1975 and 1976 year classes, were present, suggesting that the roach mortalities might be giving the rudd a chance to recover. However, very few rudd were present during 1978, possibly because lower incidences of ligulosis during 1976–1978 had allowed the roach to recover from the main outbreak of the disease in 1975, and to replace the rudd for the second time. Evidence from trap catches indicated that the perch population had shown a consistent decline between 1970 and 1977. The major phase of this decrease occurred between 1971 and 1973, when the roach population was increasing the most rapidly. Comparisons were made with changes in fish populations in other localities. The major reason for the changes observed was thought to be a competitive relationship between the plankton feeding younger stages, with roach being the dominant species, although other factors may also have been involved.     

Epidemiologic and serologic study of listeriosis in man and domestic and wild animals in Austria]

In the framework of a study aimed to ascertain the possibilities of infection transmission from mother to child the athors examined serologically gravid women for toxoplasmosis and antibodies against listeriosis, using routine methods, in Austria in 1974, 1975 and 1975. Almost all gynecologists of the region of Styria (Austrial), who systematically delivered data concerning abortions, premature births and stillbirths, were invited to take part in the study. At the same time data concerning domestic and wild animals examined for antibodies against listeriosis in Austria in 1974, 1975, 1976 and 1977, were compared.     

Family size and children's education in Matlab, Bangladesh

This study examines the relationship between family size and children's education in Bangladesh for two periods - 1982 with high fertility and 1996 with low fertility - using data from the Matlab Health and Demographic Surveillance System of the ICDDR,B: Centre for Health and Population Research. Children aged 8-17 years (27,448 in 1982 and 32,635 in 1996) were selected from households where the mother was aged 30-49 years and the father was the head of household. Children's education was measured in terms of completed years of schooling: at least class 1 (among 8-17 year olds), at least class 5 (among 12-17 year olds) and at least class 7 (among 15-17 year olds). After controlling for all variables in the multivariate analyses, level of children's education was not found to be associated with family size during the high fertility period. The family size-education relationship became negative during the low fertility period. In both periods children of educated mothers from wealthier households and those who lived close to primary/high schools had more education, but this socioeconomic difference reduced substantially over time. Boys had more education than girls during the high fertility period but this difference disappeared during the low fertility period. As birth rates fall and the proportion of children from small families increases an increase in children's education is to be expected.     

Breast-feeding in Bangladesh

In this paper the duration of breastfeeding is examined in relation to demographic and socioeconomic characteristics of women and households. 98% of Bangladesh mothers breastfeed their children from birth. In data from the Bangladesh Fertility Survey conducted in 1975-1976 on 4998 live births, the mean duration of breastfeeding was 27.3 months. Duration of breastfeeding was positively related with the age of women. Female children were breastfed for periods about 5 months shorter than male children. Children born to urban mothers were breastfed for shorter durations than children born to rural mothers of all age groups. The duration of breastfeeding decreased with the increase of education of the mother. Promotion of breastfeeding should be a primary responsibility of family planning clinics. Further decline in the duration of breastfeeding would increase levels of fertility and infant and child mortality.     

Effect of infant mortality on subsequent fertility in Pakistan and Sri Lanka

This study used data from the 1975 World Fertility Surveys in Pakistan and Sri Lanka to examine the association between fertility and infant mortality. A positive association between the mean number of children ever born and the number of child deaths was found in both rural and urban areas of each country. In Pakistan, women with no child loss had 3.3 children ever born while those who lost 1 child had 4.7 children; in Sri Lanka the figures were 3.5 and 5.4 children, respectively. However, child replacement was much less marked when controls were introduced for demographic and socioeconomic factors. When deaths at specific parities were examined, and age and time since previous birth were controlled, child replacement at the 1st parity was reduced to .3 in Pakistan and .2 in Sri Lanka. Further control for a series of socioeconomic factors (e.g. husband's level of education, husband's occupation, household structure, religion, standard of living) reduced the child replacement ratio to .2 children in Pakistan and zero in Sri Lanka. Replacement was slightly more pronounced when there were fewer surviving male children. This analysis suggests that the relationship between infant mortality and fertility is complex. A possibility that could not be explored in this study is that variation in fertilitty may itself be responsible for some of the variation in infant mortality.     

Alteration in the zooplankton community of a fly ash treated lake

The zooplankton community in Lake Charles East, Indiana, was sampled from June, 1974 through September, 1977 as part of a lake restoration study. About 1.8 × 10⁴ kg of lime and 1.8 × 10⁶ kg of ponded fly ash were added to the lake during May through August, 1975 to precipitate phosphate and seal the sediments. Annual mean species number (5.2–11.3) and annual mean species diversity (H′, 0.9–1.3) were highest in 1976, the first year after treatment. By the second post-treatment year these variables had returned to pretreatment levels. Prior to treatment Cladocera were dominant during fall and early winter (Sept.–Dec. 1974), with Copepoda dominant in late winter and spring (Jan.–May 1975). After treatment Cladocera were dominant throughout the fall and winter (Nov. 1957–May 1976). Copepoda were again dominant in August 1976. The short term effect of the treatment appeared to be termination of the latter part of the copepod annual cycle through elimination of aestivating copepodites in the summer and increased abundance of Cladocera during the winter and spring immediately following treatment. Community composition one year after treatment was similar to that observed prior to treatment.     

Bearing the Burden: Portage Labor as an Adaptive Response to Predictable Food Deficits in Eastern Nepal

Wage work such as portage labor is one of several adaptive strategies by which rural households in Nepal supplement their subsistence agriculture. This study, conducted in the hills of eastern Nepal in 1997, surveyed the landholdings and household subsistence base of 50 commercial porters hired to transport loads from Jiri to various destinations in Solu Khumbu. A major goal was to test the hypothesis that porter households tend to have smaller landholdings than the average household in this region. An unexpected result was that porter households in this study owned nearly as much arable land (1.07 ha) as the mean of 1.15 ha for all hill families in eastern Nepal. Household grain sufficiency correlated significantly (P < 0.01) with farm size (r = 0.53). The majority of the porters lived in villages located at either the origin or the endpoint of their portage work. The study also examined several variables that might explain why portage labor is a full-time occupation for some Nepalis, but a part-time “casual” occupation for others. The most significant difference between households of full-time and part-time porters was the availability of workers at home for managing the household’s land and livestock resources. Households of full-time porters were better able to spare a family member for full-time wage labor because they had significantly more adult workers of either gender (P < 0.05) than households of part-time porters. Full-time and part-time porter households did not differ significantly with regard to family size, land ownership, or number of food-deficit months.     

Food sharing at meals

The presence of a kinship link between nuclear families is the strongest predictor of interhousehold sharing in an indigenous, predominantly Dolgan food-sharing network in northern Russia. Attributes such as the summed number of hunters in paired households also account for much of the variation in sharing between nuclear families. Differences in the number of hunters in partner households, as well as proximity and producer/consumer ratios of households, were investigated with regard to cost-benefit models. The subset of households involved in reciprocal meal sharing is 26 of 84 household host-guest pairs. The frequency of reciprocal meal sharing between families in this subset is positively correlated with average household relatedness. The evolution of cooperation through clustering may illuminate the relationship between kinship and reciprocity at this most intimate level of food sharing.     

Socioeconomic determinants of cultivation of non-wood forest products in southern Nigeria

Cultivation of non-wood forest products (NWFP), although a veritable means of ecosystem and biodiversity conservation and improved natural resource management, has not been sustained in southern Nigeria (Nigeria’s major forest region) notwithstanding the unprecedented rate of depletion of the resource in the wild. For example, efforts in the past to support cultivation of NWFP in southern Nigeria under a USAID funded Cross River State forestry project, especially through nursery establishment for some rural communities, was not sustained as the initiative was abandoned by the participants. Hence to promote cultivation of NWFP, this study ascertained socioeconomic factors that influence cultivation of NWFPs. Multi stage sampling technique was used in selection of respondents (households) from two States: Cross River and Enugu States of southern Nigeria. A sample size of 400 households was used for the study. Probit and multinomial logistic regressions were used in estimating NWFP cultivation. The findings show that cultivation of NWFP was positively determined by gender, farming occupation (especially of women farmers) distance to forests where NWFP was collected, proportion of household food from NWFP, and medium wealth category. Age had a negative effect on cultivation until the age of 46 after which the effect became positive. In addition, household size, gender and farming occupation of household heads positively influenced cultivation of NWFP in plantations as against home gardens while gender and farming occupation had positive effect on cultivation of some stands of NWFP as against home gardens. Incorporating the findings of this study in future intervention project for NWFP cultivation will help sustain the initiative.     

Spot-distribution in Maniola jurtina (Lepidoptera) on small islands in southern Sweden

The Meadow Brown Butterfly, Maniola jurtina L., which is polymorphic for spotting on hind wings, was studied for five years on four small (0.15–1.0 km²) islands off the south coast of Sweden. Samples of females and males were unimodal for 0 and 2 spots, respectively. Spot-distributions remained unaltered in 1973–1974 but changed significantly in 1975 only to be restored again in 1976 and 1977. The change in 1975 was assumed to be associated with an unusually dry and warm summer and the results are discussed in terms of natural selection.     

An investigation into inter-plot interactions, in experiments with mildew on barley, using balanced designs

Serial designs, balanced for effects of neighbours, were used in 1975–1977 to investigate interactions between plots of spring barley given different treatments for the control of powdery mildew (Erysiphe graminis DC. f. sp. hordei Mérat). Differences in amounts of disease, between similarly treated plots, could be related largely to the treatments applied to the neighbouring plots and to wind directions. Amounts of disease in plots were usually increased if the upwind neighbour was untreated but untreated plots themselves were also affected by neighbours, having least disease where the upwind neighbour was sprayed early. Differences in mildew due to treatment were reflected in grain yield. Yields also provided evidence of interactions between plots. Interference, as well as altering the average response to treatments, can also contribute to variability in experiment results and lead to substantial losses in efficiency. The yields in 1975 and 1976 provided strong evidence of profiles of fertility. In the analyses, adjustment by covariates, employed to allow for these profiles, gave substantial net gains in accuracy.     

The life cycle of Chironomus anthracinus in Lough Neagh

Chironomus anthracinus generally had a one year life cycle at 8 m depth in Lough Neagh, during the study period. In spring 1975 however only a proportion of the population emerged as usual, the rest remaining a second year in the benthos to emerge in 1976. The mean dry weight of larvae just before emergence was 2.8 mg in 1971 and 2.6 mg in 1974 but only 1.6 mg in 1975, and it seems that larvae must reach a weight of at least 1.0 mg in the early spring to emerge that year. Considering temperature, oxygen saturation and standing crop of phytoplankton as factors influencing the life cycle, mean monthly chlorophyll a (phytoplankton) was weakly correlated with mean monthly increase in weight and % monthly weight increase could be related to temperature.     

The role of Anthocoris species (Hemiptera: Anthocoridae) in the integrated control of the damson-hop aphid (Phorodon humuli)

Field studies in 1974, 1975 and 1976 investigated integrated control of the damson-hop aphid Phorodon humuli on hops. After the aphicidal effects of an early-season soil drench of mephosfolan had declined, natural enemies controlled the aphids for the remainder of the season. Anthocorid bugs, particularly Anthocoris nemoralis, were the most abundant predators. In each year a rapid decline in aphid numbers occurred in mid- to late-July, coinciding with the peak numbers of fourth and fifth instar larvae and adults, the most voracious anthocorid stages. Aphids in the cones remained under control for the rest of the season in 1974 and 1975, and increased in 1976 but damaging numbers did not develop. When predators were excluded by caging mephosfolan-treated bines, high aphid densities developed on the leaves, and the cones were heavily infested. Plants not treated with an insecticide were almost completely defoliated by late-July. Heavily infested ‘missed bines’, due to uneven uptake of mephosfolan, attracted large numbers of anthocorids, which later dispersed into the surrounding plants.     

A comparison of female- and male-headed households in Tanzania and poverty implications

Female- and male-headed households were compared using data from a Demographic and Health Survey conducted in Tanzania in 1996. Chi-squared tests showed that sex of head of household was highly significantly associated with: residence, household size and composition, radio ownership, having enough food to eat, and age and marital status of head of household. An analysis by the logit regression model showed that female-headed households were more likely than male-headed households to be in rural areas, be small, have fewer men, not have radios and not have enough food to eat. The majority of female heads of households were unmarried and older than male heads of households. The implication is that female-headed households are poorer than male-headed households.