The challenge of world health

2 development specialists have expounded on the demands world health has placed on public health. Striking declines in infant and child mortality occurred with the advent of biomedical and technical interventions in developing countries after World War II. At the same time, these interventions promoted longer lives by curing and/or treating chronic diseases in developed countries. In the 1970s, however, it was apparent that the hospital based, curative approach could not meet health needs and was very costly. In developed countries, biomedical and social sciences showed that chronic diseases did not occur due to modernization but from unhealthy behaviors, diet, and lifestyle. In fact, in 1975, the US Centers for Disease Control announced that unhealthy lifestyles contributed to 50% of all deaths while the medical system was responsible for only 11%. The US and other developed countries then began to promote healthy lifestyles, and in the 1980s, considerable improvements in health occurred, especially among adults. Developing countries which depended on the Western medical model did not experience health gains in the 1970s. Yet developing countries where health systems concentrated on carrying essential services to all people and promoted basic hygiene and sound dietary practices continued to achieve considerable health gains. In 1978, WHO an UNICEF hosted the International Conference on Primary Health Care in Alma Ata, the Soviet Union to hold these developing countries with community based health systems as models of primary health care (PHC). The 1980s witnessed the spread of PHC especially in the form of child survival which focused on oral rehydration therapy and breast feeding. The biomedical and social sciences are needed to move this health policy and program strategy forward. Governments must see to policies that promote healthy people. Political will is needed to make human welfare a high priority.     

Using nineteenth century census results: the Colombian censuses of 1835, 1843, and 1851

The author discusses three of the six national censuses taken during the ninteenth century in Colombia--those for 1835, 1843, and 1851. The focus is on the importance of macro patterns generated by the data, the methods recommended to overcome the problems of the censuses, and ways to make the information useful for historical demography.     

Audience effects on solitary faces during imagery: Displaying to the people in your head

Subjects imagined situations in which they reported enjoying themselves either alone or with others. Electromyographic (EMG) activity was recorded bilaterally from regions overlying thezygomatic major muscles responsible for smiling. Controlling for equal rated happiness in the two conditions, subjects showed more smiling in high-sociality than low-sociality imagery. In confirming imaginary audience effects during imagery, these data corroborate hypotheses that solitary facial displays are mediated by the presence of imaginary interactants, and suggest caution in employing them as measures of felt emotion.Avery Gilbert and Amy Jaffey had compelling insights throughout the course of study. We thank Paul Ekman, Carroll Izard, and Paul Rozin for extensive comments on earlier drafts. We also thank Bernard Apfelbaum, Jon Baron, Janet Bavelas, John Cacioppo, Linda Camras, Dean Delis, Rob DeRubeis, Alan Fiske, Stephen Fowler, Greg McHugo, Harriet Oster, David Premack, W. John Smith, and David Williams for their valuable comments and suggestions.     

Problems in measuring role strains and social functioning in relation to psychological symptoms

The problems that people experience in social roles can be regarded as either causes or consequences of psychological symptoms. To reflect one of these possibilities, Pearlin et al. (1981) developed measures of "role strains" which are considered sources of psychopathology. To reflect the other position, Dohrenwend et al. (1981) constructed measures of "role functioning" which are seen as consequences of psychopathology. We show that the measures developed by these two teams of investigators are similar in content and show substantial empirical overlap despite the different meanings attributed to them. In an effort to understand whether these highly correlated measures assess, "role strain" or "role functioning," we conduct an exploratory analysis of marital and housework role problems, using a small panel sample of New York City residents. Specifically, we use instrumental variables to identify reciprocal effects between psychological distress and each role area. We find that the relationship between housework role problems and distress is more consistent with Pearlin et al.'s interpretation, whereas the relationship between marital problems and distress is more consistent with that of Dohrenwend et al. Investigators interested in measuring either role strain or role functioning must bear in mind the strong possibility of contamination from the other construct.     

Employment-based health benefits: analysis of the April 1993 Current Population Survey

The April 1993 CPS differs from the March 1993 CPS in a number of respects. The April 1993 CPS supplement surveys only workers, whereas the March CPS examines the noncash benefits received by all Americans. The April CPS asks workers about health coverage in the week in which the questions were fielded, whereas the March CPS asks about coverage in the preceding year. In April 1993, there were 112.5 million civilian American workers between the ages of 18 and 64 with jobs. Eighty-two million (73 percent) of them worked for an employer that sponsored a health insurance plan, and 65 million (58 percent of all workers) participated in their employer's health plan. About one-third of workers at firms with fewer than 10 employees had employers who offer health benefits; about one-quarter of all of the workers in these firms participated in their employer's plan. Conversely, 94 percent of workers at firms with more than 1,000 employees had an employer who sponsored health benefits, and over 77 percent of these workers participated in their employer's plan. There are 16.5 million American workers whose employers sponsored health benefits but who did not participate in these benefits. Over one-half of these workers (8.5 million) chose not to be covered. Another 36 percent of these workers (5.9 million) did not participate because they were ineligible or denied coverage. Over 66 percent of the ineligible workers did not participate because they were part-time, contract, or temporary workers. Another 26 percent had not yet completed a probationary period. Among the reasons that those who chose not to participate in their employer's coverage, the vast majority (75 percent) stated they were covered by another health care plan. Twenty-nine percent stated that they chose not to purchase coverage because it was too costly or that they did not need or want the coverage. In 1993, there were 16.7 million workers with no health insurance coverage. The vast majority of these workers (95 percent) were employed by private employers. Sixty-six percent of the workers with no health insurance coverage were self-employed or worked for firms with fewer than 100 employees.     

Basic aspects of evolution strategies

Evolution strategies (ESs) are a special class of probabilistic, direct, global optimization methods. They are similar to genetic algorithms but work in continuous spaces and have the additional capability of self-adapting their major strategy parameters. This paper presents the most important features of ESs, namely their self-adaptation, as well as their robustness and potential for parallelization which they share with other evolutionary algorithms.Besides the early (1 + 1)-ES and its underlying theoretical results, the modern ( + )-ES and (, )-ES are presented with special emphasis on the self-adaptation of strategy parameters, a mechanism which enables the algorithm to evolve not only the object variables but also the characteristics of the probability distributions of normally distributed mutations. The self-adaptation property of the algorithm is also illustrated by an experimental example.The robustness of ESs is demonstrated for noisy fitness evaluations and by its application to discrete optimization problems, namely the travelling salesman problem (TSP).Finally, the paper concludes by summarizing existing work and general possibilities regarding the parallelization of evolution strategies and evolutionary algorithms in general.