The characteristics of population growth of the Dongxiang nationality and the necessity of carrying out family planning]

For a long time, the Dongxiang nationality has lived in the area of Dongxiang, which is a part of Gu Hezhou in Gansu Province. Among the various minorities in China, the Dongxiang people has been noted for their small population. In recent years, however, their population growth rate has been very high. Statistics show their annual population growth rate was 13.5% in 1970 and 32.8% in 1980. This situation is caused mainly by the young age of the population (young persons under the age of 19 constitute 55.7% of the entire population). Because of the popularity of Islam among the people, the custom of early marriage and having children at an early age has long been a tradition. Rapid population growth has created numerous problems. Food production has been unable to keep up with the speed of the population growth, and economic development cannot satisfy the needs of the rapid growing population. The Dongxiang people are physically healthy and strong, and marriages between close relatives is prohibited. Because of the backward condition in education and culture, efforts to promote the quality of the Dongxiang population have remained slow and ineffective. Starting in 1974, the local government in Dongxiang launched extensive birth control projects and positive results have been achieved. At the present time, about 62% of its population have taken birth control measures, and the natural population growth rate dropped to 15.34% in 1982.     

Adolescent Protective Factors Promoting Resilience in Young Adults at Risk for Depression

In a longitudinal, community-based study, adolescent protective factors for those at risk for depression were identified that were associated with resilient outcomes in young adulthood. For those with childhood risk factors for major depression, significant protective factors included family cohesion, positive self appraisals, and good interpersonal relations. Findings may help inform the development of prevention and treatment programs for adolescents vulnerable to depression. Implications for future research and clinical practice are discussed.     

Efe fathers: one among many? A comparison of forager children's involvement with fathers and other males

The study reported describes Efe (pygmy) forager one-, two-, and three-year-olds' involvement with males. The Efe of northeastern Zaïre were chosen because their social organization allows us to examine hypotheses based on studies in Western, technologically complex societies about the distinctive role fathers play in the lives of their young children. Behavioral observations of Efe children's day-to-day activities with fathers, men and boys were recorded using a focal subject sampling technique (Altmann, 1974). Two behavioral measures were created to capture the extent to which males were involved with children: Social engagement describes males' involvement with children and social attention describes eavesdropping by children on males' everyday activities. Eight one-year-olds, 7 two-year-olds and 8 three-year-olds were each observed for six, one-hour observation sessions that were distributed evenly over the daylight hours. Data were analyzed using the traditional measure of involvement (e.g., adult males) and using a newly developed measure of the involvement of the average individual (e.g., average adult mate). Comparisons at each of the ages showed that fathers were consistently like other men in the extent to which children participated in social activities with them and watched their activities. Only fathers' level of social engagement declined significantly as children grew older. Boys' role relative to other males became increasingly distinctive as children aged. The findings suggest that Efe fathers may not be unique in the same sense assumed by Western study ideals, and raise questions about the special status given to fathers in Western theory and data. The patterning of mate involvement with children is discussed in terms of Efe community life, and in terms of Efe children's developing understanding of their relationship with fathers and other males.     

Genetic algorithms for numerical optimization

Genetic algorithms (GAs) are stochastic adaptive algorithms whose search method is based on simulation of natural genetic inheritance and Darwinian striving for survival. They can be used to find approximate solutions to numerical optimization problems in cases where finding the exact optimum is prohibitively expensive, or where no algorithm is known. However, such applications can encounter problems that sometimes delay, if not prevent, finding the optimal solutions with desired precision. In this paper we describe applications of GAs to numerical optimization, present three novel ways to handle such problems, and give some experimental results.     

Extrapolation designs and Φp-optimum designs for cubic regression on the q-ball

This paper continues earlier work of the authors in carrying out the program discussed in Kiefer (1975), of comparing the performance of designs under various optimality criteria. Designs for extrapolation problems are also obtained. The setting is that in which the controllable variable takes on values in the q-dimensional unit ball, and the regression is cubic. Thus, the ideas of comparison are tested for a model more complex than the quadratic models discussed previously. The E-optimum design performs well in terms of other criteria, as well as for extrapolation to larger balls. A method of simplifying the calculations to obtain approximately optimum designs, is illustrated.     

Characterizations of geometric distribution and discrete IFR (DFR) distributions using order statistics

Let X be a discrete random variable the set of possible values (finite or infinite) of which can be arranged as an increasing sequence of real numbers a₁<a₂<a₃<…. In particular, a_i could be equal to i for all i. Let X_1n≦X_2n≦?≦X_nn denote the order statistics in a random sample of size n drawn from the distribution of X, where n is a fixed integer ≧2. Then, we show that for some arbitrary fixed k(2≦k≦n), independence of the event {X_kn=X_1n} and X_1n is equivalent to X being either degenerate or geometric. We also show that the montonicity in i of P{X_kn = X_1n | X_1n = a_i} is equivalent to X having the IFR (DFR) property. Let a_i = i and $\text{G(i) = P(X≧i), i = 1, 2, …}$. We prove that the independence of {X_2n ? X_1n ∈B} and X_1n for all i is equivalent to X being geometric, where B = {m} (B = {m,m+1,…}), provided G(i) = q^i?1, 1≦i≦m+2 (1≦i≦m+1), where 0<q<1.     

The experience of carrying out the technical responsibility system in the birth control of Peng County, Sichuan Province]

Following the establishment of the system of fixed responsibility in production in Peng County, Sichuan Province, the County's Family Planning Office and Public Health Bureau in 1980 broadened the system of technical responsibility in birth control by defining tasks and goals. The commune public health office should guide birth control technology, lower the incidence of unplanned pregnancies and the number of abortions. The number of fertile women using IUDs should be over 80%, and its failure rate should be less then 10%; the failure rate of male ligature should be less than 3%. Commune members should give 1 jiao to the public health office for expenses incurred in birth control technology. If all the goals are reached, then there would be economic rewards outside the total public support system. That is, 1 jiao is awarded for each IUD inserted, 2 jiao for male ligatures and 3 jiao for female ligatures. Infractions such as poor attitude, irresponsibility, or delaying surgery are fined from 1-20 yuan. The following situations resulted from having implemented the system of technical responsibilty for birth control: 1) medical personnel had the authority to initiate action concerning birth control technology; 2) the quality of surgery was raised, while the incidence of errors was lowered; 3) the costs of surgery were lowered; and 4) because abortions are not awarded with economic incentives, medical personnel tended to perform more preventive surgery rather than corrective surgery.     

Basic indicators for identifying types of age structure]

Problems of population aging in China are considered in the light of the adoption of a policy of one child per family. The possibility of inadequate labor force resources and a ratio of elderly population too great for those of working age is considered. Methods of estimating population age structure are presented, and the economic problems of both aging and youthful populations are discussed.     

Demographic characteristics and shared values

This study investigated the extent to which person-organization values alignment is affected by demographic variables (e.g., gender, age, educational level, marital status, family status, hierarchical level, years of managerial experience, and organizational size) across a wide variety of organizations. Values alignment, using two separate measures, was directly related to positive work attitudes and this relationship was moderated by several respondent characteristics. The potential impact of organizational acculturation is proposed as minimizing the impact of demographic factors within organizations.