Fertility differentials in rural Sierra Leone: demographic and socioeconomic effects.
Explore the source record for details and available documents.
Africa↗
SEARCH · Search PubMed
Results for “Rural Spatial Distribution”
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.
Evidence for space-time clustering of lung cancer deaths.
One parish in Louisiana has the highest reported incidence of lung cancer in the United States. Statistically significant space-time clustering (P < 1.0) was present among lung cancer deaths (1960-1975) in residents of the urban portion of this parish. The spatial distribution of cancer deaths in the urban portion of the parish was compared to age, year of death, race, and sex matched control deaths to determine the risk of lung cancer associated with residential proximity to industry. For industries with independently increased risks, the combination of industries produced risks of 1.9 to 3.2 (P < .05) for residing within 1.2 km of one or more industries to three or more industries, respectively. The results suggest residential exposure to industrial effluents is a factor contributing to the rate of lung cancer.
Female↗
Impacts of sewage irrigation on heavy metal distribution and contamination in Beijing, China.
A potential hazard to Beijing was revealed due to the accumulation trend of heavy metals in agricultural soils with sewage irrigation, which results in metal contamination and human exposure risk. Samples including soils and plants were collected to assess the impacts of sewage irrigation on the irrigated farming area of Beijing. Concentrations of the five elements Cd, Cr, Cu, Zn, and Pb were determined in samples to calculate the accumulation factor and to establish a basis for environmental protection and the suitability of sewage irrigation for particular land use in the urban-rural interaction area of Beijing. Using reference values provided by the Beijing Background Research Cooperative Group in the 1970s, the pollution load index (PLI), enrichment factor (EF), and contamination factor (CF) of these metals were calculated. The pollution load indices (sewage irrigation land 3.49) of soils indicated that metal contamination occurred in these sites. The metal enrichment (EF of Cd 1.8, Cr 1.7, Cu 2.3, Zn 2.0, Pb 1.9) and the metal contamination (CF of Cd 2.6, Cr 1.5, Cu 2.0, Zn 1.7, Pb 1.6) showed that the accumulation trend of the five toxic metals increased during the sewage irrigation as compared with the lower reference values than other region in China and world average, and that pollution with Cd, Cu, Zn, and Pb was exacerbated in soils. The distributions of these metals were homogeneous in the irrigation area, but small-scale heterogeneous spatial distribution was observed. Irrigation sources were found to affect heavy metal distributions in soils. It was suggested that heavy metal transfer from soils to plants was a key pathway to human health exposure to metal contamination. However, with the expansion of urban areas in Beijing, soil inhalation and ingestion may become important pathways of human exposure to metal contamination.
Agriculture↗
Risk adjustment for hospital use using social security data: cross sectional small area analysis.
OBJECTIVES: To identify demographic and socioeconomic determinants of need for acute hospital treatment at small area level. To establish whether there is a relation between poverty and use of inpatient services. To devise a risk adjustment formula for distributing public funds for hospital services using, as far as possible, variables that can be updated between censuses. DESIGN: Cross sectional analysis. Spatial interactive modelling was used to quantify the proximity of the population to health service facilities. Two stage weighted least squares regression was used to model use against supply of hospital and community services and a wide range of potential needs drivers including health, socioeconomic census variables, uptake of income support and family credit, and religious denomination. SETTING: Northern Ireland. MAIN OUTCOME MEASURE: Intensity of use of inpatient services. RESULTS: After endogeneity of supply and use was taken into account, a statistical model was produced that predicted use based on five variables: income support, family credit, elderly people living alone, all ages standardised mortality ratio, and low birth weight. The main effect of the formula produced is to move resources from urban to rural areas. CONCLUSIONS: This work has produced a population risk adjustment formula for acute hospital treatment in which four of the five variables can be updated annually rather than relying on census derived data. Inclusion of the social security data makes a substantial difference to the model and to the results produced by the formula.
Adult↗
A geostatistical analysis of the geographic distribution of lymphatic filariasis prevalence in southern India.
Gaining a better understanding of the spatial population structure of infectious agents is increasingly recognized as being key to their more effective mapping and to improving knowledge of their overall population dynamics and control. Here, we investigate the spatial structure of bancroftian filariasis distribution using geostatistical methods in an endemic region in Southern India. Analysis of a parasite antigenemia prevalence dataset assembled by sampling 79 villages selected using a World Health Organization (WHO) proposed 25 x 25 km grid sampling procedure in a 225 x 225 km area within this region was compared with that of a corresponding microfilaraemia prevalence dataset assembled by sampling 119 randomly selected villages from a smaller subregion located within the main study area. A major finding from the analysis was that once large-scale spatial trends were removed, the antigenemia data did not show evidence for the existence of any small-scale dependency at the study sampling interval of 25 km. By contrast, analysis of the randomly sampled microfilaraemia data indicated strong spatial contagion in prevalence up to a distance of approximately 6.6 kms, suggesting the likely existence of small spatial patches or foci of transmission in the study area occurring below the sampling scale used for sampling the antigenemia data. While this could indicate differences in parasite spatial population dynamics based on antigenemia versus microfilaraemia data, the result may also suggest that the WHO recommended 25 x 25 km sampling grid for rapid filariasis mapping could have been too coarse a scale to capture and describe the likely local variation in filariasis infection in this endemic location and highlights the need for caution when applying uniform sampling schemes in diverse endemic regions for investigating the spatial pattern of this parasitic infection. The present results, on the other hand, imply that both small-scale spatial processes and large-scale factors may characterize the observed distribution of filariasis in the study region. Our preliminary analysis of a mountain range associated large-scale trend in the antigenemia data suggested that a nonlinear relationship of infection prevalence with elevation might be a factor behind such observed global spatial patterns. We conclude that geostatistic methods can provide a powerful framework for carrying out the empirical investigation and analysis of parasite spatial population structure. This study shows that their successful application, however, will crucially depend on our gaining a more thorough understanding of the appropriate geographic scales at which spatial studies should be carried out.
Adult↗
Ecological models of alcohol outlets and violent assaults: crime potentials and geospatial analysis.
AIMS: Empirical tests of relationships between alcohol outlets and violence are generally conducted with statistical controls for correlates related to characteristics of people and the places in which they live. Crime potentials theory asserts that certain subpopulations are disposed to participate in criminal activities (population potentials) and certain neighborhoods are more likely to be places where crimes occur (place potentials). The current study assesses the degree to which measures of the different geographic distributions of these potentials contribute to violent crime. DESIGN: Cross-sectional data on hospital discharges for violent assaults were obtained for residents of 1637 zip code areas in California. Assault rates were related to measures of population and place characteristics using spatial statistical models corrected for spatial autocorrelated error. FINDINGS: Rates of assault were related to population and place characteristics within zip code areas, and with characteristics of populations living in adjacent zip code areas. Assault rates were greater in densely populated, poor minority urban areas with greater residential instability. Assault rates were also greater in zip code areas adjacent to densely populated urban areas. Assault rates were related significantly to local densities of off-premise alcohol retail establishments, not bars. However, densities of bars moderated substantially effects related to local population characteristics. Bars were related significantly to violence in unstable poor minority areas and in rural middle-income areas of the state. CONCLUSION: Population and place characteristics are associated with rates of violence across spatial areas. Alcohol outlets directly affect and moderate potentials for violence associated with socio-demographic groups.
Alcoholic Beverages↗
Fine-Scale Landscape Genomics Show Asymmetric Patterns of Gene Flow for the Invasive Mosquito Aedes albopictus.
Mosquito-borne viruses like dengue, Zika, and chikungunya pose increasing health risks in the United States due to the expanding range of Aedes albopictus, a highly invasive mosquito species that now has a global distribution. Aedes albopictus thrive in artificial containers associated with anthropogenic land use, allowing populations to reach high numbers in urban and suburban environments. While the global spread of Ae. albopictus has been well characterized, the effects of heterogeneous urban landscapes on dispersal and gene flow at fine spatial scales remain unclear. This study analyzed the genetic connectivity of Aedes albopictus populations collected in Wake County, North Carolina in 2018. We used single nucleotide polymorphisms (SNP) data from double-digest restriction-enzyme associated DNA sequencing (ddRADseq) and examined genetic connectivity through principal component analysis (PCA) and genetic network analysis. We then evaluated migration and source-sink dynamics using a Bayesian approach for SNP data (BA3-SNP). We found little evidence of genetic clustering or isolated populations of Ae. albopictus in Wake County, suggesting high gene flow between sites. Migration analysis demonstrated asymmetric gene flow from rural to urban regions within Wake County, with greater gene flow occurring between and within urban regions. These findings suggest that the pattern of gene flow of Ae. albopictus populations within local metropolitan areas may involve urban city centers serving as genetic sinks and surrounding suburban and rural regions serving as sources. This study highlights how heterogeneous landscapes shape mosquito population connectivity and migration at fine spatial scales, which is critical for informing vector control and public health intervention strategies.
Aedes albopictus↗
Beijing Declaration, 25 September 1987.
This Declaration aims to do the following: "Decrease the annual population growth rate in the Asian region to 1% by the year 2000; decrease mortality rates, specifically infant mortality, throughout the region by 50% by 2000; effect a balanced distribution of population in Asian countries through policies designed to accommodate urban growth and stem rural-to-urban migration; devise mechanisms that can serve as alternatives for the extended family in providing social, economic and psychological security for Asia's aging population; improve the status of women and their health, education and employment and create public awareness and acceptance of the changing role of women in Asia and of its social, political and cultural implications; and observe an appropriate date in 1988 as the "Day of Three Billion" with a view to informing every Asian family of the necessity, urgency and significance of the population issues in the region." The Declaration also urges the governments of Asian countries to allocate an adequate share of their national resources to meet the needs of family planning and other programs that have a bearing on population.
Adult↗
From structural push to chain migration: notes on the persistence of migration to Ciudad Juarez, Mexico.
"Spatial differentiation in regional welfare is often assumed to be one of the most important explanatory factors in individual migration behaviour. By the weight of 'push' against 'pull', migrants walk in step with the unequal distribution of socio-economic opportunities. In the case of Ciudad Juarez [Mexico], these 'structural factors' only appear to have determined migration in its first stages; especially recently 'non-structural' factors seem to be at the root of the ever-increasing process."
Americas↗
Recent population characteristics and growth in the USSR.
"Data from the preliminary results of the 1989 census and Naseleniye SSSR 1987 permit analyses of age-sex structures of the Soviet population and distributions by civil divisions of natural growth rates, total population growth, urban growth, rural growth, percent urbanization, and growths of cities. The paper complements the treatment of census results by macroregions appearing in the November 1989 issue of Soviet Geography...by summarizing trends emerging at a finer scale of analysis and providing recent background information on demographic components of population change."
Age Distribution↗
Polycyclic aromatic hydrocarbons in the San Francisco Estuary water column: sources, spatial distributions, and temporal trends (1993-2001).
The composition of PAH in surface waters was examined over a range of spatial and temporal scales to determine distributions, trends, and possible sources. Water samples were collected from 1993 to 2001. PAH in organic extracts were analyzed by gas chromatography-mass spectrometry (GC-MS) and 25 individual target PAH summed to get the total PAH concentration in each water sample. The distribution of median total PAH concentration by estuary segments was Extreme South Bay (120 ng l(-1)) > South Bay (49 ng l(-1)) > North Estuary (29 ng l(-1)) > Central Bay (12 ng l(-1)) > Delta (7 ng l(-1)). Overall, total PAH concentrations were significantly higher in the Extreme South Bay compared to all other segments, and the Central Bay and Delta were significantly lower than all other segments (Kruskal-Wallis, H = 157.27, df = 4, p < 0.0005). This distribution reflects the large urbanized and industrialized areas that border the southern portions of the estuary and the less populated and rural areas that surround the Delta. Temporal trend analysis showed a statistically significant temporal trend in total PAH concentration at only one of the 18 sampling stations situated throughout the estuary (San Jose, significant decrease, p = 0.031, r(2) = 0.386, n = 12). PAH isomer pair ratio analysis showed that PAH in estuary waters were derived primarily from combustion of fossil fuels/petroleum (possible PAH source contributors include coal, gasoline, kerosene, diesel, No. 2 fuel oil, and crude oil) and biomass (possible contributors include wood and grasses), with lesser amounts of PAH contributed from direct petroleum input.
California↗
The geography of despair among 15-44-year-old men in England and Wales: putting suicide on the map.
OBJECTIVE: To investigate the spatial patterning and possible contributors to the geographical distribution of suicide among 15-44- year-old men. DESIGN: Small-area analysis and mapping of geo-coded 1988-94 suicide mortality data and 1991 census data using random-effects smoothing. SETTING: 9265 electoral wards in England and Wales (mean population of men aged 15-44- years: about 1220). MAIN RESULTS: Two main patterns emerged: (a) in all of the 10 most densely populated cities studied, suicide showed a "bull's-eye" pattern with rates highest in the inner-city areas and, in some cases, low rates in the peripheries, and (b) suicide rates were high in coastal areas, particularly those in more remote regions. Possible indicators of social fragmentation, such as the proportion of single-person households in an area, were most strongly and consistently associated with rates of suicide in both urban and rural areas. Levels of unemployment and long-term illness accounted for some of the coastal patterning. Although characteristics of areas accounted for more than half of the observed variability, substantial between-area variability in rates remained unexplained. CONCLUSIONS: The area characteristics investigated here did not fully account for the higher suicide rates observed in the most rural or remote areas. Alongside social and economic aspects, rural life itself may have an independent effect on the risk of suicide. A greater understanding of local geographies of suicide, and particularly the possible interactions between characteristics of people and their environments, might assist the design of prevention strategies that target those areas (and their characteristics) where risk is concentrated.
Adolescent↗
The spatial pattern of urban population growth in Java, 1980-1990.
"The emergence of fast-growing peri-urban regions and corridors joining large cities has been a feature of rapid urban growth in Asia in the last fifty years. These areas have been characterised by a mixture of urban and rural activities and by strong rural-urban linkages. This paper uses data from the 1980 and 1990 Indonesian Censuses to measure the extent to which this process has been occurring on Java in the intervening decade. It calculates and categorises the absolute and proportional increase in the urban populations of each kabupaten in Java, and examines some of the reasons for the emerging patterns. The paper concludes with a discussion of the policy implications of the findings."
Asia↗
Mortality impact of the AIDS epidemic: evidence from community studies in less developed countries.
BACKGROUND: The AIDS epidemic is now more than a decade old and direct evidence of mortality impact has become measurable, as indicated by an increasing number of publications presenting empirical data from less developed countries. METHODS: This review focuses on the evidence of mortality impact among adults and children in community studies. The majority of these studies are located in Africa, particularly eastern Africa, where the AIDS epidemic is conjectured to be older than in other less developed countries. RESULTS: Community studies show a two- to threefold increase in total adult mortality with an even larger increase in mortality among young adults in communities with adult HIV prevalence levels below 10%. Mortality amongst HIV-infected adults ranges from 5 to 11% per year, and more than half of all adult deaths can be attributed to HIV. HIV-infected women die at an earlier age than men and thereby lose significantly more productive years of life. Follow-up studies of incident cases are few, but population-based data indicate that the median survival time is substantially longer than originally thought on the basis of mortality amongst HIV-infected commercial sex workers. Tuberculosis incidence is on the increase, but evidence of additional impact on mortality is hitherto limited. Infant and early child mortality among children of HIV-infected mothers is two to five times higher than among children of HIV-negative mothers in follow-up studies of maternity-based and community samples. CONCLUSION: There is now empirical evidence of the mortality impact of HIV/AIDS from several community studies. The large increase in adult mortality and moderate increase in child mortality lead to dramatic falls in life expectancy. For instance, in a rural area of Uganda, which has an HIV prevalence of 8%, life expectancy has dropped from just under 60 years to 42.5 years.
Acquired Immunodeficiency Syndrome↗
Genetic diversity and gene flow among southeastern Queensland koalas (Phascolarctos cinereus).
Habitat fragmentation and destruction associated with the rapid urban and rural development of southeast Queensland presents an immediate threat to the survival of koala populations within this region. A sensitive method combining heteroduplex analysis (HDA) with temperature gradient gel electrophoresis (TGGE) was optimized to detect within-species variation in a mitochondrial DNA (mtDNA) control-region fragment, approximately 670 bp in length, from the koala. Eight different haplotypes were characterized in koalas, of which four were novel. Analysis of mtDNA diversity in 96 koalas from five populations in southeast Queensland revealed that the number of haplotypes in a single population ranged from one to five, with an average within-population haplotype diversity of 0.379 +/- 0.016, and nucleotide diversity of 0.22 +/- 0.001%. Nucleotide divergence between populations averaged 0.09 +/- 0.001% and ranged from 0.00 to 0.14%. Significant genetic heterogeneity was observed among most populations, suggesting that koala populations may be spatially structured along matrilines, although this may not be universal. The limited distribution of the central phylogenetic haplotype suggested the possibility of historical population bottlenecks north of the Gold Coast, while the presence of two highly divergent haplotypes at the Moreton site may indicate the occurrence of one or more undocumented translocation events into this area.
Animals↗
Breastfeeding decline in urban China: an exploratory study.
"Retrospective data collected in two urban neighborhoods of Tianjin, People's Republic of China, reveal a decline in the rate and duration of breastfeeding since the mid-1930's.... The evidence indicates that breastfeeding declined as women became involved in work outside the home, as they adopted a form of postmarital residence that separated them from other relatives, as income increased, and as their rural origins decreased. No evidence was found to indicate a relationship between breastfeeding and parity or sex preferences."
Asia↗
The household distribution of trachoma in a Tanzanian village: an application of GIS to the study of trachoma.
The distribution of active trachoma in Kahe Mpya, Tanzania, an endemic village of approximately 1000 people, was mapped spatially and analysed for associated risk factors and evidence of clustering. An association between distance to water source and active disease was demonstrated, although this was reduced after accounting for the lack of independence between cases in the same household. Significant clustering of active trachoma within households was demonstrated, adding support to the hypothesized importance of intra-familial transmission. The spatial distribution of trachoma was analysed using the spatial scan statistic, and evidence of clustering of active trachoma cases detected. Understanding the distribution of the disease has implications for understanding the dynamics of transmission and therefore appropriate control activities. The demonstrated spatial clustering suggests inter-familial as well as intra-familial transmission of infection may be common in this setting. The association between active trachoma and geographical information system (GIS) measured distance to water may be relevant for planning control measures.
Adolescent↗
Child survival in Indonesia.
The 1980 infant mortality rate of 107/1000 live births in Indonesia was 2 to 3 times the average rate in surrounding Asian countries. Provincial rates vary from 187 in West Nusa Tenggara to 62 in Yogyakarta. This variation is explained in part by female education levels, access to health facilities, and the impress of health aid and system programs, especially family planning. In addition, mortality rates and the usage of modern health care continue to reflect historical and cultural imprints. A program strategy for improvements in infant and child mortality focus on 4 basic elements: 1) growth monitoring, 2) oral rehydration therapy, 3) breast feeding, and 4) immunization. These efforts are delivered largely through the Expanded Immunisation Programme and the Family Nutrition Programme. A potential major breakthrough in primary health care has been realized with the development of a network of integrated health posts (posyandu) which deliver multiple services more efficiently in rural areas.
Asia↗