Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Population Control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources
PubMed1976

Socio-cultural modalities in population control.

Overpopulation with its identifiable and noxious results, is probably the most ominous and potentially destructive condition existing in current world society. The etiology of this problem includes the failure of mankind to develop compatible interrelationships between members of his own family, clan, society, and world population. The author predicts that all efforts to achieve world population control will be essentially ineffective unless the insights of the holistically oriented science of social psychiatry are refined into principles and rules which direct population control endeavors. This paper reviews the extent and severity of the problem and stresses the need for the operational implementation of the value systems and methodologies of social psychiatry. The author believes that effective population control is possible if the actions of world leaders are directed toward efforts to achieve satisfaction of the basic (Ur) needs of all individuals and groups for physical survival, socialization, and transcendence.

Community Psychiatry↗
PubMed1978

Field independence and attitudes toward population control.

The hypothesis that differences between field independence and dependence would lead to different attitudes about population control activities was tested using 37 students as subjects. The Hidden Figures Test was used to measure field independence while an author-developed scale assessed attitudes. Expected relationships were found; field-independent persons were more independent of the opinions of others, agreed with active population control measures, and were in favor of smaller family size.

Adult↗
PubMed1990

[Survival and causes of secondary mortality in patients undergoing coronary bypass. Comparison with a same age control population].

During 10 years, 867 patients in whom the same surgical team had performed coronary bypass were followed up regularly without any of them being lost sight of. Moreover, the cause of all deaths in this group could be determined fairly accurately. A comparison of mortality between these patients and an age-matched control population studied longitudinally, year after year, showed that the mortality rate in the surgical group was slightly higher than in the control group (84 vs 77). Conversely, when the operative mortality was discounted, it appeared that the patients who survived coronary bypass had a much better survival than the control population (47 vs 77). Without any doubt, the prognosis for life is improved by surgery. In particular, patients with three-vessel disease (58 per cent), tight stenosis of the common coronary artery (10-25 per cent) or altered ventricular ejection fraction (about 30 per cent) would probably have died without myocardial revascularization. However, this study produced a rather astonishing result: compared with the control population, the decrease of long-term mortality in patients who survived coronary bypass was due not only to the decrease of cardiovascular deaths (16 vs 24) but also of deaths due to cancer (15 vs 27) or to other causes (16 vs 26). This suggests that a more hygienic life and a correct medical follow-up contribute to a large extent to the long-term survival of these surgical patients.

Actuarial Analysis↗
PubMed1977

Parallel studies of HLA antigens in patients with rheumatic heart disease and scleritis: comparisons with three control populations.

Parallel studies were carried out on HLA antigens in patients with rheumatic heart disease and scleritis. Comparison with one control population showed a significant excess of BW15 in both disease samples, while a comparison with two other control populations, showed the excess not to be significant. Possible reasons for this discrepancy are discussed, together with the effect on statistical significance of a small percentage of false antigen assignments in one of the samples. A small systematic serological false assignment of an antigen can, by itself, produce a significant result more easily if the frequency of the antigen being detected is low than if it is high. It is suggested that this effect may contribute to the discrepant significant results obtained by different workers in some HLA and disease studies.

Eye Diseases↗
PubMed1976

Casual, basal and supplemental blood pressures in 519 first-degree relatives of substantial hypertensive patients and in 350 population controls.

1. The casual blood pressure is the sum of the relatively stable basal pressure taken under defined conditions of rest and the labile supplemental pressure (casual minus basal), which represents the response to the current degree of physical, mental and probably metabolic stimulation. 2. The basal and supplemental blood pressures behave differently and it seems likely that different factors are involved in their pathogenesis. 3. The 5 and 8 years follow-up mortality is closely related to the basal pressure but not to the supplemental pressure. 4. The rise with age in the basal blood pressure is greater in the relatives of substantial hypertensive patients than in population control subjects. 5. Above the age group 30-39 years there is an increase in the rate of rise of the mean basal blood pressure with age among the first-degree relatives of hypertensive patients. In a population control group an acceleration in the rate of rise of the mean basal blood pressure with age also occurs but a decade or more later than in the relatives of hypertensive patients. 6. In males the mean supplemental pressures (systolic and diastolic) do not rise appreciably with age and the mean supplemental pressures of first-degree relatives and control subjects do not differ appreciably. 7. In females the mean supplemental pressures rise with age but, except after age 60 years, the pressure rise in first-degree relatives is only a little greater than in control subjects. 8. When hypertensive patients with similar casual blood pressures are compared the basal blood pressures are higher in patients with glomerulonephritis than in essential hypertensive patients. 9. In the first-degree relatives of substantial hypertensive patients high-ranking basal blood pressures occur much more frequently than in general population control subjects. 10. The close resemblance of the blood pressures in like twins indicates that genetic or familial factors have an important influence on blood pressure, and on the occurrence of frank hypertension.

Adolescent↗
PubMed1993

Effectiveness of the Waksberg telephone sampling method for the selection of population controls.

The effectiveness of the Waksberg telephone sampling method and practical aspects of its implementation were evaluated during the selection of control subjects for a population-based case-control study conducted in Maryland, Virginia, West Virginia, and Washington, DC, in 1991. The first stage of the two-stage sampling procedure was equivalent to simple random sampling. Each telephone number selected was dialed up to 13 times to establish the type of connection. Residential connections were used to generate additional telephone numbers in the second stage by changing the last two digits. Overall, 3,860 telephone numbers yielded 1,311 residences. The proportion of residences was higher in the second stage (54%) than in the first (11%), while that of numbers "not in service" was lower (12% vs. 67%, respectively). Fewer calls (8,735) were made than would have been required by a simple random sampling procedure (up to 18,522). The geographic distribution of residences was similar at both stages of sampling. At the end of enrollment, each sampling unit had yielded 9.8 residences, but only 64% reached 9-11 residences. Compliance rates were 96% for screening (1,259 of 1,311 residences), 90% for interviewing (362 of 403), and 86% overall. Relative to simple random sampling, the Waksberg method considerably reduced the total number of telephone calls, but the sampling process was more complex to manage. This method is particularly suitable for selecting population controls when the density of residential connections is low and variables of interest are not homogeneous within sampling units. Random digit dialing remains an effective method for selecting population controls.

Data Collection↗
PubMed1995

[Adaptation to effort in patients with chronic cardiac insufficiency; study by post-exercise Doppler echocardiography, comparative results with a control population].

Adaptation to exercise was studied by post-exercise Doppler echocardiography in patients with chronic cardiac failure and an apparently healthy control population matched for age. This post-exercise Doppler echocardiographic method initially introduced for the detection of myocardial ischaemia has already been validated in normal subjects for the analysis of haemodynamic changes caused by exercise providing the data is recorded in the first 5 minutes following recovery in the recumbent position. Eleven patients with chronic cardiac failure in NYHA classes II or III with a mean age of 54 +/- 11 years and 6 controls (mean age: 46 +/- 9 years) were investigated. The patients had been stabilised for at least 3 months with a vasodilator and diuretic therapy: the control subjects had no medication. After bicycle ergometry performed to 70% of maximum capacity, the subjects were positioned in the left lateral recumbent position. Doppler echocardiography was then performed in the immediate recovery phase. When compared to the control population, the patients with cardiac failure had a reduced chronotropic reserve, a smaller increase in the parameters of myocardial contractility (maximal aortic velocity, maximal aortic acceleration and left ventricular fractional shortening) without an increase in left ventricular end diastolic dimensions in subjects with severe dilatation under basal conditions (left ventricular end diastolic dimension 69 +/- 3 mm). This result suggests the absence of a Frank-Starling effect. The lack of adaptation of the peripheral vascular system was demonstrated by the lack of reduction of left ventricular end systolic stress, already greatly increased at rest (176 vs 77 +/- 10 g/cm2 for patients, compared with controls; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1997

Lysenkoism and the population control movement.

The case of Lysenkoism in the Soviet Union helps us understand how people's wrong beliefs can be influenced by what the information they receive from outside, especially when there is a large volume of media coverage and there is no contrary information to be heard. The population control movement in contemporary United States has many parallels to the Lysenko episode.

Genetics, Population↗
PubMed1986

Estimation of response to selection and utilization of control populations for additional information and accuracy.

Problems associated with testing and estimation of response to selection are examined. An alternative procedure with increased power for testing hypotheses is given. The increased power results from a more precise method of estimating the variance about response. The new method is based on a Satterthwaite approximation which combines variance components estimated more precisely by other sources of variation in the analysis of variance. The expected variance about response and expected mean squares for the analysis of variance, used in the Satterthwaite procedure, are given. When intergeneration environmental trends cannot be ruled out, a control population must be used to estimate response to selection. However, if the experimental and control populations do not respond in the same direction and with the same magnitude to common environmental effects, then the usual method of estimating response by deviating the experimental values from the control will result in biased estimates. An alternative procedure, using the control as a covariate to adjust for environmental trends, gives relatively unbiased estimates of response in this situation. Some bias results from measurement error associated with the control. However, this bias is usually minimal.

Analysis of Variance↗
PubMed1996

Socio-economic characteristics of artificial insemination donor (AID) couples compared with matched population controls.

Socio-economic characteristics like education, occupation and religion may play a role when choosing or refraining from treatment by artificial insemination by donor (AID). From a cohort of 189 AID-patients, the socio-economic characteristics were established from the notes and a questionnaire that was sent to all patients to complete the available data. The response rate to the questionnaire was 83.6% (158 women). Data were compared with population controls that were matched for age and region. AID patients in this study had significantly lower educational and/or occupational levels than matched population controls and were significantly more religious.

Adult↗
PubMed1975

Population control in confined colonies of golden hamsters (Mesocricetus auratus Waterhouse).

The mechanisms by which confined colonies of Golden Hamsters regulate the density of their population were investigated. Six experimental populations were established with two males and two females each and allowed to grow freely for 3-8 months. At no time did any population exceed eight individuals. This appeared to be the result of a high rate of infant mortality due to failure of pregnant and parturient females to isolate themselves from the others. Two other populations were then established allowing many more nesting areas and more room for dispersal, but animals continued to crowd together and infant survival did not improve. These results contrast sharply with the large ultimate populations and only slowly developing disturbances seen in rats and mice. This difference in population control appears to be the direct result of a species difference in the tolerance of adults for strange newborns. In two further short-term experiments, the effects of the number and sex of adults in the founding population were systematically examined. The critical density at which no pups survived past the first day was six or more animals; females appeared to contribute more than males to infant mortality.

Animals↗
PubMed1977

Evaluation of control populations: body weight and rate of gain in Japanese quail.

1. Two control populations of quail of different origin were maintained by cyclical mating, one for 4 and the other for 6 generations. Means, heritabilities, genetic and phenotypic correlations of body weights at 1, 14 and 35 d and rates of gain from 1 to 14 d and from 14 to 35 d did not show any trend of change with generation. 2. The variability between generations was greater in the characters having intermediate and lower values of heritability, genetic and phenotypic correlations than in those with higher values.

Animals↗