Grandmothers' influence on mother and child health

This study is based on interviews with grandmothers during July-September 1992-93 in Sudan. The study shows that grandmothers play a significant role in health education and child care within families in the Sudan. Grandmothers, who are not aware of the changes in knowledge, also promote harmful traditions. The authors recommend that health education be directed to elderly women and grandmothers in order to change beliefs and practices that continue to be harmful to children and mothers. Grandmothers were found to give sound advice on child birth, such as movement during labor, breast feeding immediately after birth, and birth intervals of 2-4 years. Grandmothers also gave sound advice on good nutritional practices during pregnancy and use of fermented cereals as weaning foods. Grandmothers recommended use of fenugreek for lactating mothers and use of mint and haharaib for stomach upsets, remedies that are beneficial. Babul is useful after an episiotomy for its antibacterial effects. Harmful advice includes recircumcision after delivery, short birth intervals, and avoidance of contraception. Female genital mutilation (FGM) is a major practice that exposes girls and mothers to a greater risk of mortality during childbirth and pregnancy. The sample of grandmothers agreed on the importance of sex education for a girl before marriage. Unfortunately, 57% of grandmothers recommended 14 years as a suitable age for marriage. Grandmothers generally believed wrongly that riding bicycles, drinking coffee, and wearing trousers by girls would increase their sexual desires. Grandmothers explained menstruation to granddaughters and offered home-made remedies for cramps. 45% believed that there were no disadvantages to FGM and recommended FGM at ages 2-5 years. Most viewed fevers as a danger that required a doctor's care. Advice varied among grandmothers according to socioeconomic class.     

Sampling from spatial databases

This paper deals with techniques for obtaining random point samples from spatial databases. We seek random points from a continuous domain (usually ²) which satisfy a spatial predicate that is represented in the database as a collection of polygons. Several applications of spatial sampling (e.g. environmental monitoring, agronomy, forestry, etc) are described. Sampling problems are characterized in terms of two key parameters: coverage (selectivity), and expected stabbing number (overlap). We discuss two fundamental approaches to sampling with spatial predicates, depending on whether we sample first or evaluate the predicate first. The approaches are described in the context of both quadtrees and R-trees, detailing the sample first, acceptance/rejection tree, and partial area tree algorithms. A sequential algorithm, the one-pass spatial reservoir algorithm is also described. The relative performance of the various sampling algorithms is compared and choice of preferred algorithms is suggested. We conclude with a short discussion of possible extensions.     

West and Central Africa

This article reviews scientific and other literature during the 1990s that links migration and mobility with the spread of sexually transmitted diseases (STDs), including HIV/AIDS. The focus is on key population groups linked to the spread of HIV and STDs in West and Central Africa: migrant laborers, truck drivers, itinerant traders, commercial sex workers (CSWs), and refugees. Countries with high emigration and immigration tend to have high levels of HIV infection, with the exception of Senegal. The main destination of immigrants are Senegal, Nigeria, and Cote d'Ivoire in West Africa and Cameroon, Congo, Gabon, and Congo in Central Africa. The risk of infection and the spread of HIV is variable among migrants. There is little in the literature that substantiates hypotheses about the strong association between migration and HIV-positive status. Information is needed on the duration, frequency of return visits, living conditions, sexual activities with multiple partners, and information before departure, along the routes, at final destination, and at the time of returns. Action-based research in five West African countries (Burkina Faso, Cote d'Ivoire, Mali, Niger, and Senegal) should produce results in late 1998. Comparable studies in Central Africa are unknown. Regional studies should be complemented by local studies. Prevention would benefit from studies on the relative size of these five population groups by geographic location.     

Curved Chaotic Map Time Series Models and Their Stochastic Reversals

This paper considers two types of chaotic map time series models, including the well-known tent, logistic and binary-shift maps as special cases; these are called curved tent and curved binary families. Deterministic behaviour is investigated by invariant distributions, Lyapunov exponents, and by serial dependency. Stochastic time reversal of the families is shown to produce models which have a broader range of stochastic and chaotic properties than their deterministic counterparts. The marginal distributions may have concentrations and restricted supports and are shown to be a non-standard class of invariant distribution. Dependenc y is generally weaker with the reversed stochastic models. The work gives a broad statistical account of deterministic and stochastically reversed map models, such as are emerging in random number generation, communica tion systems and cryptography     

The majority legal status of women in southern Africa: implications for women and families

Women in many countries of southern Africa do not have majority status or have only recently gained this right. Majority status grants individuals adult legal status and the right to bring matters to court, own and administer property, have legal custody of children, and contract for marriage. This article summarizes the legal status of women in Botswana, Lesotho, South Africa, Swaziland, Zambia, and Zimbabwe. Lack of majority status contributes to the ongoing risk of poverty for women and makes them overly dependent on men. Compounding the situation in these countries is the presence of a dual legal system. Improving the situation of women and their families involves targeting changes in the legal system, influencing implementation of laws, educating women about their rights, and giving women needed support to seek their legal rights. The legal status of women must be viewed in the context of historical changes in the economic, educational, political, and cultural developments of society.The research for this paper was conducted during her previous faculty affiliation with the University of Michigan, School of Social Work. Her research interests include the impact of social change on women and families, rural mental health services, and health and mental health linkages. She received her Ph.D. from Rutgers University and her M.S.W. from the Columbia University School of Social Work.Her research interests are gender, work and family, culture and power, social transformations in rural and peri-urban communities, critical education, women and community politics, history of women, family and kinship issues, and community-based program development and evaluation. She received her M.S.W. from Dalhousie University, Halifax.     

Statistics in epidemiology: the case-control study

This article presents a general review of the major trends in the conceptualization, development, and success of case-control methods for the study of disease causation and prevention. "Recent work on nested case-control, case-cohort, and two-stage case control designs demonstrates the continuing impact of statistical thinking on epidemiology. The influence of R. A. Fisher's work on these developments is mentioned wherever possible. His objections to the drawing of causal conclusions from observational data on cigarette smoking and lung cancer are used to introduce the problems of measurement error and confounding bias."     

Prevalence of gambling among Minnesota public school students in 1992 and 1995

The purposes of this study were to examine the prevalence of gambling among youth, compare rates of gambling between 1992 and 1995, and determine what levels of gambling frequency may be considered common and uncommon. The two samples included 122,700 Minnesota public school students in the 6th, 9th, and 12th grades in 1992; and 75,900 9th and 12th grade students in 1995. Students were administered the Minnesota Student Survey, a 126-item, anonymous, self-administered, paper-and-pencil questionnaire that inquires about multiple content domains, including gambling behaviors. The same questionnaire, with minor revisions to the gambling items, was administered in both 1992 and 1995 to students in their classrooms by the Minnesota Department of Education. There were slight decreases in overall gambling rates from 1992 to 1995. The majority of students gambled at least once during the past year. However, most did not play any game on a weekly/daily rate and did not report any problems associated with their gambling. Gender, grade, and race effects were found for gambling frequency. Boys gambled more often than girls, and 9th and 12th grade students gambled more often than 6th grade students. Asian American and White students reported lower rates of gambling frequency than Mexican/Latin American, African American, and American Indian students. From a statistical standpoint (i.e., beyond the 97.7 percentile), it may be considered in the uncommon range for girls to play two or more games at a weekly/daily rate, and for boys to play four or more games at a weekly/daily rate. Variables associated with gambling frequency included antisocial behavior, gender, and alcohol use frequency. Although the finding that gambling did not increase from 1992 to 1995 is encouraging, this is the first generation of youth to be exposed to widespread accessability to gambling venues and gambling advertising and it will be important to continue monitoring the prevalence of youth gambling.     

Marriage selection and age patterns of mortality: a mathematical investigation

"In this paper, we use simulation models to demonstrate the complexity of the relationship between the marriage selection process and the resulting RMRs [relative mortality ratios]. In particular, we show that marriage selection alone can produce a relative mortality ratio which remains large and relatively constant at ages far beyond the marriage span....Our general objective...is to determine the range of age patterns of relative mortality which could, in theory, result from marriage selection on the basis of health characteristics. We also evaluate the effects of variations in the marriage selection mechanisms on the resulting mortality patterns....We develop and apply several simple mathematical models of the marriage selection process. In order to distinguish the potential consequences of marriage selection from marriage protection, we consider hypothetical populations in which causal effects are absent....We begin by considering an extremely simple marriage selection process and subsequently explore a more realistic selection model based on recent death and marriage rates for Japan."