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At least 1,567 records · Page 87Linked to original sources
PubMed1982

Intermetropolitan migration and quality of life.

The aim of this paper is to assess the relative importance of economic and quality of life (QOL) factors as determinants of inter-metropolitan migration in the United States. The study is based on the generalized systemic gravity model of Alonso and on data from a sample of 25 SMSAs over the period 1965-1970. "The most striking feature of the empirical results is the apparent lack of importance of origin economic and QOL factors as determinants of outmigration.... On the other hand, the empirical results suggest both economic and QOL factors to be significant determinants of inmigration."

Americas↗
PubMed1996

Preliminary evidence for a theory of the fractal city.

"In this paper, we argue that the geometry of urban residential development is fractal. Both the degree to which space is filled and the rate at which it is filled follow scaling laws which imply invariance of function, and self-similarity of urban form across scale. These characteristics are captured in population density functions based on inverse power laws whose parameters are fractal dimensions. First we outline the relevant elements of the theory in terms of scaling relations and then we introduce two methods for estimating fractal dimension based on varying the size of cities and the scale at which their form is detected. Exact and statistical estimation techniques are applied to each method respectively generating dimensions which measure the extent and the rate of space filling. These methods are then applied to residential development patterns in six industrial cities in the northeastern United States...."

Americas↗
PubMed1991

Bacterial indicators of risk of diarrhoeal disease from drinking-water in the Philippines.

Inadequate measures of water quality have been used in many studies of the health effects associated with water supplies in developing countries. The present 1-year epidemiological-microbiological study evaluated four bacterial indicators of tropical drinking-water quality (faecal coliforms, Escherichia coli, enterococci and faecal streptococci) and their relationship to the prevalence of diarrhoeal disease in a population of 690 under-2-year-olds in Cebu, Philippines. E. coli and enterococci were better predictors than faecal coliforms of the risk of waterborne diarrhoeal disease. Methods to enumerate E. coli and enterococci were less subject to interference from the thermotolerant, non-faecal organisms that are indigenous to tropical waters. Little difference was observed between the illness rates of children drinking good quality water (less than 1 E. coli per 100 ml) and those drinking moderately contaminated water (2-100 E. coli per 100 ml). Children drinking water with greater than 1000 E. coli per 100 ml had significantly higher rates of diarrhoeal disease than those drinking less contaminated water. This threshold effect suggests that in developing countries where the quality of drinking-water is good or moderate other transmission routes of diarrhoeal disease may be more important; however, grossly contaminated water is a major source of exposure to faecal contamination and diarrhoeal pathogens.

Bacterial Infections↗
PubMed1983

Location, use, and locational efficiency of health facilities in a Madras neighbourhood.

The present paper has two related aims: an attempt to measure locational efficiency of health facilities in a Madras neighbourhood - Alandur - through an analysis of use patterns obtained from a questionnaire study, and an application of two significant methods on problems relating to organisation of health services - set covering reasoning and maximal covering location method. Some major conclusions of the two related analyses are: - Generally use declines with distance. However, beyond the eleventh distance zone, the use increases sharply, only to decrease after the fourteenth distance zone, the number of visits attributable to quality services at locations in these distance zones. - Among the variables determining the use patterns, distance is most important, followed by cost of treatment, the quality care, nature of facility and its availability. - Set covering method yielded 5 potential health location sites which proved to be efficient in both population coverage and maximum time distances of five and ten minutes /maximal covering location method/. Two alternative sets identified by set covering method proved to be inefficient on both population and distance counts when maximal covering method was applied.

Community Health Services↗
PubMed1996

Street children in South Africa: findings from interviews on the background of street children in Pretoria, South Africa.

In the present study findings from interviews on the background of street children in Pretoria, South Africa are presented, discussed, and compared with research done in the past on South African street children. Findings from the investigation indicate that the average age of South African street children is approximately 13 years, predominantly of male African origin. Most have been on the streets for three years or longer, and they cited family violence, parental alcoholism, abuse, and poverty as the main motivating factors for leaving home. Most of these findings are common among street children all over the world.

Adolescent↗
PubMed2005

Spatial variations in selected metal contents and particle size distribution in an urban and rural atmosphere of Islamabad, Pakistan.

Spatial variations in total suspended particulate matter (TSP) were investigated for distribution of metals and particle size fractions in the urban and rural atmosphere of Islamabad, Pakistan. The metals Na, K, Fe, Mn, Pb, Cd, Cr, Zn, Ni and Co, and the particle fractions <2.5, 2.5-10, 10-100 and >100 microm were included in the study. TSP samples were trapped on glass fibre filters using high volume samplers and quantification of metals was done using Atomic Absorption Spectrometry employing HNO(3) based wet digestion. At the urban site, Na was dominant at 2.384 microg/m(3) followed by K, Fe and Zn with 0.778, 0.667 and 0.567 microg/m(3) as mean concentrations, respectively. The metal levels for the rural site ranged from 0.002 microg/m(3) for Cd to 1.077 microg/m(3) for Na. However, compared with the urban site, mean Pb concentration showed an almost two-fold enhancement, i.e., 0.163 Vs. 0.327 microg/m(3). Metals and particle size source identification was done using Principal Component Analysis and Cluster Analysis. Five sources were traced out for the urban site: industrial, soil, automobile emissions, metallurgical industries and excavation activities. For the rural site, four sources were recorded: agricultural, automotive emissions, excavation activities and metallurgical units. Collectively, for both the sites, PM(10-100) emerged as a major contributor to TSP, followed by PM(2.5-10), PM(<2.5) and PM(>100) in that order. The metals showed in general positive relationship with fine particulate fractions (PM(2.5-10), PM(<2.5)), and negative correlation with coarse fractions (PM(10-100), PM(>100)). Comparison with the corresponding data from various Asian sites revealed that the levels of Na, K, Fe, Mn, Co and Ni for the present study were lower than those reported for grossly polluted cities of the world.

Agriculture↗