Biomedical subjects
Publications and source records attributed to P A Morrison.
A new practical synthesis of 17alpha-acetoxy-11beta-(4-N, N-dimethylaminophenyl)-19-norpregna-4,9-diene-3,20-dione (CDB-2914) is described. The synthesis gives easily isolable solids at all steps and is amenable to large-scale process.
This paper projects school enrollments in Santa Ana, California and evaluates the accuracy of the projections. It emphasizes the distinctive aspects of a local setting undergoing substantial immigrant influx and highlights the uncertainties that must be addressed. I adapt existing forecasting approaches to such local situations, match assumptions to future unknowns, and devise "early warning" thresholds keyed to timely decision making. This hybrid approach offers forecasters a useful point of departure in local settings dominated by wide margins of uncertainty and inherently risky assumptions.
As U.S. cities accommodate increasing ethnic and racial diversity, political choices may unify or divide their local populations. Those choices pull communities toward two different modes of pluralism: traditional "melting pot" assimilation or a complex mosaic of racial and ethnic assertiveness. Central to this issue is equity and empowerment, which may be accentuated by minority populations' size, structure, and spatial concentration. We examine two potential modes of local empowerment: "dominance," whereby each group is the majority of voters in single election districts (reinforcing separative tendencies), and "influence," whereby a group gains "influential minority" status in several districts (reinforcing unifying tendencies).
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This article explores the broad topic of how the selective character of human migration and changing family circumstances may shape the intensity of local need among the future elderly. At origin, it is the healthier, better educated, and more affluent elderly who venture to migrate; and although people migrate from a broad spectrum of origins, they flow selectively to a narrow spectrum of destinations. At the same time, contemporary changes in family makeup and internal division of labor alter their capacity to care for elderly members. These demographic realities define a policy issue ripe for study. 1990 census data can reveal how the pressures of population aging will diffuse spatially, in terms of timing and intensity and, given the complex interaction of migration selectivity and family transformation, who will be distanced from whom, and with what consequences. Scattered evidence from earlier years casts light on certain facets of this issue: (a) the ties between elderly and their children, (b) the differing configurations of migration flows generating elderly concentration in locales, and (c) the changing nature of elderly concentration in recent decades. With 1990 census data, it will be possible to extend certain findings and consider their implications for how future aging and dependency may express themselves locally.
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We examine repeat migration sequences in the United States especially those that entail a return, using data from the Panel Study of Income Dynamics. Our guiding hypotheses derive from the concepts of location-specific capital and imperfect information. Descriptive analysis elucidates the dynamics, tempo, and differential frequency of repeat migration among various socioeconomic groups. Results disclose difference among migrants who choose to return or move onward to a new location, or do not move again, and lend support to our analytical framework. Major findings are: (1) the propensity to return to an area varies directly with the amount of location-specific capital that is left behind and inversely with the ex-resident's length of absence, (2) which repeat migration sequence unfolds--return or onward--depends on the ex-resident's educational level and experience of unemployment.
Demographic change bears directly on the formulation of social policy because it determines in large part whose wealth or income is redistributed to whom. Where demographic events modify the recipients and donors in such redistribution, they may sharply alter the consequences of existing legislation or create constituencies for new laws. This article considers how current and emerging demographic changes are affecting the redistribution of wealth across generations, across income groups, and across geographic regions.
The population changes in San Jose and St. Louis between 1960 and 1970 exemplify the two broad trends-urban formation followed by metropolitan dispersal-that have shaped 20th-century urbanization in this country. The fact that these developmental trends were expressed through demographic processes found to be common to both cities, despite their contrasting recent experiences, suggests that generalizations can be made about the complex forces underlying urbanization. The formation of metropolitan San Jose's population parallels the traditional process whereby a region's growth comes to be focused, through migration, on a few urban centers. The modern variant is not characterized by a rural-to-urban shift, however, but by migration flows among urban areas, and particularly to a few most-favored areas, such as San Jose. Migratory growth has left a powerful demographic legacy in San Jose. This legacy is also instructive for studying the migratory formation of any new city's population. Its demographic character determines its demographic destiny, whose likely variations we can now perceive with some clarity. San Jose's population is both youthful and chronically migratory. The presence of many prospective parents and relatively few elderly persons lays a broad foundation for the population's continued growth through natural increase, despite the national downturn in fertility (14). Even without further net in-migration, the population of new cities like San Jose would continue to grow at an above-average rate. The hypermobility of San Jose's population (that is, its propensity for further migration) also has an important bearing on the future. With about 21 migrants entering and 17 departing each year per hundred residents, San Jose's rapid migratory growth rests (as it would in other new cities) on a precarious arithmetic balance. A significant dip in local employment growth could easily reduce net migration to a small fraction of its present high level. Even a slight decline would result in the inflow's no longer exceeding the high volume of outflow. Demographic analysis alone cannot foresee such an employment downturn, but if it happened, the migratory downturn probably would be swift. Hypermobility also works the other way; and given San Jose's focal position in California's expanding metropolitan structure (with its virtually endless supply of migratory growth), net migration could resume with equal swiftness. The outward dispersal of population from central cities that has occurred in St. Louis has been accelerating in other cities as well, and will remain a prominent feature of U.S. urban growth. It may seem paradoxical that in a period noted for something called "urban growth" there are so many declining central cities, but that is merely one indication that the "central city" no longer is the real city, except in name. Real city or not, the central city can expect to come into political conflict with other jurisdictions created in the process of dispersion. In cities like St. Louis, where population is dispersing but old political boundaries are fixed, the problems of the central city are separated from the resources in the suburbs. Transitional problems associated with persistent and severe outmigration also arise: accumulation of disadvantaged citizens, declining demand for city housing, and a diminished replacement capacity in the population. Carried far enough, the last of these problems results in natural decrease, and thereafter the population's decline acquires its own dynamic. As noted earlier, the white population in St. Louis has reached this point: The number of persons dying now exceeds the number being born. For two reasons, this natural decrease can do little other than intensify. First, a substantial proportion of whites are either entering or already within the high-mortality age brackets. The white population's crude death rate therefore will continue to rise. Second, prospective parents are becoming scarce among St. Louis's whites, and the national evidence that parents in general will choose to have smaller families continues to mount. The white population's crude birth rate is therefore likely to fall, barring a dramatic increase in fertility or a strong and sustained inflow of childbearing families. Nor is St. Louis's black population likely to grow substantially. It is expanding steadily through natural increase, but black migration out of the city is more than enough to cancel that increase.
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Data from the High School and Beyond panel study indicate that of 13,061 female high school sophomores who responded to both the baseline questionnaire in 1980 and a 1982 follow-up, 41 percent of blacks, 29 percent of Hispanics and 23 percent of non-Hispanic whites said they either would or might consider having a child outside of marriage. Such willingness was higher among young women who, according to their background characteristics, were at greater risk of teenage parenthood. In addition, young black women were more willing to consider having a child while single than were white or Hispanic respondents, at every level of risk. The data also show that, with the possible exception of Hispanics, willing respondents generally registered much higher rates of nonmarital childbearing over the two years following the baseline survey than the young women unwilling to consider nonmarital childbearing. Respondents' reports on their own disciplinary problems in school and on their class-cutting and absenteeism showed that such problem behavior was related to the teenagers' willingness to consider nonmarital childbearing: Proportionally more of the respondents who ranked high on a scale of problem behavior were willing to do so, even when background differences were controlled for. In addition, when the respondents' educational expectations were used as proxy measures of the potential opportunity costs of single parenthood, the results revealed that the higher their educational expectations, the lower their willingness to have an out-of-wedlock birth.(ABSTRACT TRUNCATED AT 250 WORDS)