Biomedical subjects

R A Wanner

Publications and source records attributed to R A Wanner.

11 recordsLinked to original sources

PubMed1986

The vertical mosaic in later life: ethnicity and retirement in Canada.

Given the distinctive historical experiences, cultural features, and status positions of the diverse ethnic groups in Canadian society, we anticipate that these differences will influence the retirement behavior and conditions of their members. This paper examines the effects of ethnic group membership for immigrants to Canada on the timing of retirement and the sources and amounts of retirement income using data from the Public Use Sample of the 1981 Census of Canada. Separate but parallel analyses are conducted for men and women to take into account their distinctive labor force experiences. We find that membership in Asian, African, or Latin American ethnic groups is associated with both later retirement and a lower probability of receiving social insurance and private pension benefits, as well as appreciably lower income among elderly men. This is likely the result of changes in pension legislation in the 1960s and 1970s reducing benefits to recent immigrants.

Africa↗

PubMed1983

Ageism in the labor market: estimating earnings discrimination against older workers.

In this paper we attempt to determine the degree to which older persons employed full-time experience a decline in earnings not related to a decline in productivity. We label such a decline in earnings "discrimination." Using panel data for a cohort of men aged 45 to 54 in 1966, we examined trends in earnings between 1966 and 1976 and the effects of labor force experience on earnings controlling for factors related to productivity, such as health, time on the job, and specific occupational training, as well as other factors known to influence earnings levels. Comparing earnings attainment models estimated at both time periods, the effect of experience on earnings was negligible in 1966 but substantial and negative in 1976. By far the largest component in the real earnings decline experienced by these men between 1966 and 1976 was associated with the increase in age-related experience.

Age Factors↗

PubMed1983

Comparison of the effects of radiation and hyperthermia on prenatal retardation of brain growth of guinea-pigs.

On day 21 of pregnancy guinea-pigs were exposed to hyperthermia or gamma radiation. The effects on prenatal growth and especially brain growth of offspring were compared. Doses of 0.04-0.99 Gy of radiation produced a dose-dependent and irreversible reduction of brain weight in the offspring, but had little effect on body weight. Treatment with hyperthermia resulting in maternal temperatures of 41.8-43.9 degrees C after exposure in a heated incubator for an hour also produced a dose-related micrencephaly in the offspring. Comparison of the two agents showed that a dose increment of 0.525 Gy of radiation produced a deficit in brain weight equivalent to an elevation of 1 degree C in maternal temperature. Using this guinea-pig brain weight assay system a threshold was detected of between 0.05 and 0.10 Gy for retardation of brain growth.

Abnormalities, Radiation-Induced↗

PubMed1977

The dimensionality of the urban functional system.

This paper suggests that the formulation and testing of hypotheses relating the functional role of cities in a society to other urban structure and process variables might be facilitated by substituting a continous variable approach to the functional system for the prevailing discrete typologies. Using variables indexing the scope of economic activities in U.S. communities at two points in time, we elaborate a technique for identifying the dimensions underlying an existing typology, and the 56 largest SMSA's are ranked along these dimensions.

Classification↗

PubMed1976

The effect of hyperthermia on the neuroepithelium of the 21-day guinea-pig foetus: histologic and ultrastructural study.

Hyperthermia was induced in guinea-pigs on day 21 of gestation by placing them in an incubator set at 42-5 degrees-43-0 degrees C for 1 hr. At intervals thereafter foetuses were removed from the uterus and sections of the telencephalon were prepared for light and electron microscopy. The histologic and ultrastructural appearance of the telencephalon of the normal 21-day guinea-pig foetus was described for comparative purposes. Damage to cells in mitosis characterised by clumping of chromosomes, and dispersal of polysomes in interphase cells were observed immediately after hyperthermia. Breakdown of the network of junctional complexes was apparent at 4 hr and cellular proliferation was inhibited for 6-8 hr. Degenerative changes and cell deaths were observed deep in the venticular zone after 8 hr; the extent of cell death was related to the post-stressing temperature. Proliferation was resumed at 8 hr and damaged and dead cells moved outward toward the intermediate zone. Phagocytosis of debris by large mononuclear cells was a common finding. Cytoplasmic inclusions, some of which were Feulgen-positive, were present in otherwise normal ventricular cells. Occasional dead cells and empty spaces were present in the ventricular zone at 24 hr and by 48 hr the ventricular zone was normal in appearance. It was concluded that previously observed micrencephaly in the offspring of guine-pig mothers which were heat stressed on day 21 of gestation resulted from a temporary cessation of proliferation and partial depopulation of the proliferating neuroepithelium.

Animals↗

PubMed1975