Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DEMOGRAPHY”

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 73 records · Page 4Linked to original sources
PubMed1985

Some myths in the demography of aboriginal Australians.

The author discusses the proliferation of stereotypes and myths concerning the demography of aboriginal Australians. "In this paper, four of these myths will be discussed, in the hope that a basis for constructive analysis of recent and historical demographic change can be laid." The myths considered pertain to the validity of studying aboriginal societies that have been in contact with non-aboriginal societies, disorder in the aboriginal family, the study of aborigines as a third world population, and the relationship between high fertility and aboriginal poverty.

Australia↗
PubMed2003

A macroscopic approach to demography.

A canonical/lognormal model for human demography is established, specifying the net maternity function and the age distribution for mothers of new-borns using a single macroscopic parameter vector of dimension five. The age distribution of mothers is canonical, while the net maternity function normalizes to a lognormal density. Comparison of an actual population with the model serves to identify anomalies in the population which may be indicative of phase transitions or influences from levels outside the demographic. Tracking the time development of the parameter vector may be used to predict the future state of a population, or to interpolate for data missing from the record. In accordance with classical theoretical considerations of Backman, Prigogine, et al., it emerges that the logarithm of a mother's age is the most fundamental time variable for demographic purposes.

Adolescent↗
PubMed2006

Demography, immigration background, difficulties with living in Japan, and psychological distress among Japanese Brazilians in Japan.

This study examined the relationship of demography, immigration background, and concerns and difficulties associated with living in Japan to nonpsychotic psychological disturbance (i.e., "caseness") measured by the GHQ-12. Data are from a sample of 265 Japanese Brazilians (JB) residing outside the Tokyo Metropolitan area. Employing multiple logistic regression analyses, it was found that JB who experienced lower economic conditions, lived alone, stayed relatively longer in Japan, migrated to Japan due to their dissatisfaction with the socio-economic conditions in Brazil, and who experienced severe family life concerns had a significantly higher ratio of "caseness," that is psychologically distressed. In contrast, JB over the age of 25 years, who acquired moderate Japanese language proficiency and decided to return to Brazil as soon as possible, were observed to have a significantly lower ratio of psychological distress. Socio-cultural and situational interpretations of the findings are presented.

Acculturation↗
PubMed1991

The service system at the crossroad of demography and policy making--implications for the elderly.

In many countries today, there is an ongoing debate regarding health in 'crisis'. Each country seems to experience a crisis regardless of the level of expenditures in the field of social and health services. This article discusses different influences that affect social and health service systems in relation to the elderly, and brings up the controversy concerning the elderly as a threat to available resources in society. Most examples are based on Swedish sources, but some American and British sources are used as well. Borrowing from the age stratification model, the concepts role and cohort are used as analytical concepts. The role concept is discussed in relation to the development of organizations for retired people. The analysis offered little support for the thesis that the elderly would attain a power position. Thus, a demand for societal resources by means of political strength is less feasible. When looking at the elderly from the cohort perspective, the article includes a discussion of the interdependent forms of care for the elderly; self-care, informal care and formal care. Although great challenges await social and health services systems in this respect, the article concludes that any possible crisis in health and social service systems is socially constructed and not a deterministic effect of demography as such.

Aged↗
PubMed2005

[Radiation oncology training in France: demography, analysis of motivations of the young specialists, evaluation of the training].

During the 5 past national courses organised by the French society of radiation oncology (SFRO), three different types of survey were performed to analyse demography, motivations and quality of training of the young specialists. During the 5 past years, 50 radiation oncologists were training for the whole country (about 15 per year were graduated). A recent increase the number of young specialists is observed with a total number of 50 in 2000 to 75 in 2005. Nevertheless, the number of young specialists is dramatically insufficient and exposes for the future to an important demographic crisis. Analysis of motivations of choice for radiation oncology confirms the influence of a practical stage of oncology during the second cycle of the medical studies for 60% of the young specialists. Analysis of practical and theoretical training was performed according to the point of view and living experiences of the students. On the other hand, informations from teachers were less complete. Some needs are emphased as: 1) the quality of the follow during the training (importance of the recent implementation of a logbook); 2) importance of theoretical and practical training at the radiotherapy department; 3) help and incentive for research and scientific publication.

Demography↗
PubMed2006

Changes in the distribution of lung cancer cell types and patient demography in a developing multiracial Asian country: experience of a university teaching hospital.

A comparison of patients with lung cancer diagnosed at the University of Malaya Medical Centre, Kuala Lumpur, Malaysia from October 1991 to September 1999 with another group of lung cancer patients diagnosed at the same hospital during an earlier period of 1967-1976 was undertaken to determine whether there had been a change in the distribution of lung cancer cell types and patient demography. The number of histologically and/or cytologically proven lung cancer cases was 583 from October 1991 to September 1999 and 278 from 1967 to 1976. The mean (S.D.) age of the patients during the period 1991-1999, 60.1 (12.0) years was similar to that of patients during the period 1967-1976, 60.3 (12.2) years. There was no shift of the peak age distribution of lung cancer (i.e., the 7th decade) between the two periods. In the recent period, the percentage of patients with adenocarcinoma had increased significantly to 43.2% from 25.2% while that of large cell carcinoma had decreased to 3.3% from 11.9%. The percentages of patients with squamous cell carcinoma (SCC) and small cell lung cancer remained stable. In the period 1967-1976, SCC was the commonest cell type in men and in smokers while adenocarcinoma was the commonest cell type in women and in never smokers. In the period 1991-1999, adenocarcinoma was the commonest cell type in both men and women as well as in smokers and never smokers.

Adenocarcinoma↗
PubMed1999

[Evolution of the demography of anesthesia practitioners in French speaking Sub-Saharan Africa].

OBJECTIVE: To assess the course of the demography of anaesthesia providers in French-speaking subsaharian countries. TYPE OF STUDY: Retrospective survey. PERSONS: Doctors trained in anaesthesia and nurse anaesthetists registered in West African medical societies. METHODS: Countries, hospitals, anaesthesia manpower, seniority and place of training were analysed. RESULTS: In the 13 French-speaking subsaharian countries including 97.5-M inhabitants, 122 doctors and 868 nurses were registered as anaesthetists in 1998. Mean ratios were one doctor trained in anaesthesia for 799,180 inhabitants and one nurse anaesthetist for 112,327 inhabitants. From 1980 to 1998, these figures increased by a factor 11 for doctors (+1100%) and by a factor two for nurses (+100%). Most doctors were working in the chief town, in both public and private health care institutions. CONCLUSIONS: In all French-speaking subsaharian countries, a major shortage of doctors trained in anaesthesia is existing.

Africa South of the Sahara↗
PubMed2003

Count data, detection probabilities, and the demography, dynamics, distribution, and decline of amphibians.

The evidence for amphibian population declines is based on count data that were not adjusted for detection probabilities. Such data are not reliable even when collected using standard methods. The formula C = Np (where C is a count, N the true parameter value, and p is a detection probability) relates count data to demography, population size, or distributions. With unadjusted count data, one assumes a linear relationship between C and N and that p is constant. These assumptions are unlikely to be met in studies of amphibian populations. Amphibian population data should be based on methods that account for detection probabilities.

Amphibians↗
PubMed2003

The influence of demography, population structure and selection on molecular diversity in the selfing freshwater snail Biomphalaria pfeifferi.

Several forces may affect the distribution of genetic diversity in natural populations when compared to what is expected in a random-mating, constant size population of neutral genes. One solution for unravelling their respective influence is to study several genes at once in order to better reflect the true genealogy. Here we reconstruct the evolutionary history of the freshwater snail Biomphalaria pfeifferi over its entire distribution, using eight African populations, and three congeneric species as outgroups. A phylogenetic analysis was conducted using amplified fragment length polymorphism markers, and sequences at eight nuclear non-coding loci and one mitochondrial gene were used to analyse population structure. The geographic distribution of variation suggests greater affinities within than among regions. The pattern of variability at both the nuclear and mitochondrial DNA (mtDNA) loci is consistent with a bottleneck, although population structure may also partly explain our results. Our results are also indicative of the role of selection, whether positive or purifying, in the mtDNA. This highlights the fact that the interfering influences of population structure, demography and selection on molecular variation are not easily distinguished.

Animals↗
PubMed2006

Mating patterns and demography in the tristylous daffodil Narcissus triandrus.

Mating patterns in plant populations are influenced by interactions between reproductive traits and ecological conditions, both factors that are likely to vary geographically. Narcissus triandrus, a wide-ranging heterostylous herb, exhibits populations with either two (dimorphic) or three (trimorphic) style morphs and displays substantial geographical variation in demographic attributes and floral morphology. Here, we investigate this variation to determine if demography, morphology, and mating system differ between the two sexual systems. Our surveys in Portugal and NW Spain indicated that dimorphic populations were less dense, of smaller size, and had larger plants and flowers compared to trimorphic populations. Outcrossing rates estimated using allozyme markers revealed similar outcrossing rates in dimorphic and trimorphic populations (t(m) dimorphic=0.759; t(m) trimorphic=0.710). All populations experienced significant inbreeding in progeny (mean F=0.143). In contrast, parental estimates of inbreeding were not significantly different from zero (mean F=0.062), implying that few inbred offspring survive to reproductive maturity due to inbreeding depression. Although the majority of inbreeding results from selfing, significant levels of biparental inbreeding were also detected in eight of the nine populations (mean s(s)-s(m)=0.081). Density was negatively associated with levels of selfing but positively associated with biparental inbreeding. Population size was positively associated with outcrossing but not biparental inbreeding. There were no consistent differences among the style morphs in outcrossing or biparental inbreeding indicating that the maintenance of trimorphism vs dimorphism is unlikely to be associated with inbreeding of maternal parents.

Crosses, Genetic↗
PubMed1993

Demography, nursing and community care: a review of the evidence.

Demography is a most powerful influence upon social policy making. Policy making cannot be divorced from the constitution and the characteristics of the population for which it is intended. This paper commences by identifying and reviewing the most potent of those trends, and then examines the implications, first for the capacity of the community to cope with its dependents and then for the supply of nurses, before illustrating the importance of community nursing to government policies on community care.

Adult↗
PubMed2002

The influence of mating system, demography, parasites and colonization on the population structure of Biomphalaria pfeifferi in Madagascar.

Current evolutionary forces and historical processes interact to shape the distribution of neutral genetic variability within and among populations. Focusing on the genetics of recently introduced organisms offers a good opportunity to understand the relative importance of these factors. This study concerns variation at 8 polymorphic microsatellite loci in 30 populations of Biomphalaria pfeifferi. The sampling area spans most of the species' range in Madagascar where it was probably introduced recently. Extremely low variation was found within all populations studied, which may partly result from high selfing rates. However, this cannot account for the variance of variation across populations, which is better explained by habitat openness (that reflects environmental stochasticity), the prevalence of the parasitic trematode Schistosoma mansoni and historical demography (colonization and subsequent bottlenecks). Large global differentiation was also observed, suggesting that current gene flow among populations is limited to small distances, within watersheds and to few individuals. Our data set also allowed us to test several hypotheses regarding colonization, based on bottleneck and admixture tests. The observed pattern requires at least two independent introductions from slightly differentiated genetic sources in the western part of Madagascar. Another introduction, from a very different genetic origin, should also be postulated to explain the genetic composition of eastern populations. That this introduction occurred recently suggests that the colonization of Madagascar by B. pfeifferi is an ongoing process.

Animals↗
PubMed2000

Fractures in the elderly: epidemiology and demography.

Osteoporosis and osteoporosis-related fractures are a major source of both morbidity and cost in the elderly, the fractures that are most commonly associated with osteoporosis being those of the hip, the distal forearm and the vertebrae, although it is believed that most other fractures occurring in the elderly are also related to osteoporosis. In this review, the incidence of all types of fracture is described based on the available literature, and the foreseeable trends resulting from demographic changes are discussed. Emphasis is given to the epidemiology of hip fracture since this is the most serious consequence of osteoporosis. Hip fractures occur all over the world, most currently occurring in Western countries, mainly Europe and the USA, but it is expected that there will be a large increase in the number of hip fractures in other countries because of demographic changes. The incidence of hip fractures increases exponentially with age, resulting in a 1-year incidence of 1% in women aged 80 in Western countries. Most hip fractures occur in women, but this is again partly due to demography, because of the longer life expectancy of women. Wrist fractures occur more often in women and do not show the same increase with age as hip fractures. The incidence reaches a plateau at age 60-70. Vertebral fractures show a modest increase with age and are again more common in women than men. The incidence of all other fractures increases modestly with age

Aged↗
PubMed2002

Inferences about human demography based on multilocus analyses of noncoding sequences.

Data from 10 unlinked autosomal noncoding regions, resequenced in 15 individuals from each of three populations, were used in a multilocus analysis to test models of human demography. Each of the 10 regions consisted of approximately 2500 bp. The multilocus analysis, based on summary statistics (average and variance of Tajima's D and Fu and Li's D*), was used to test a family of models with recent population expansion. The African sample (Hausa of Cameroon) is compatible with a constant population size model and a range of models with recent expansion. For this population sample, we estimated confidence sets that showed the limited range of parameter values compatible with growth. For an exponential growth rate as low as 1 x 10(-3)/generation, population growth is unlikely to have started prior to 50,000 years ago. For higher growth rates, the onset of growth must be more recent. On the basis of the average value of Tajima's D, our sample from an Italian population was found to be incompatible with a constant population size model or any simple expansion model. In the Chinese sample, the variance of Tajima's D was too large to be compatible with the constant population size model or any simple expansion model.

Base Pairing↗
PubMed2000

Major factors influencing linkage disequilibrium by analysis of different chromosome regions in distinct populations: demography, chromosome recombination frequency and selection.

Linkage disequilibrium (LD) mapping of disease genes is complicated by population- and chromosome-region-specific factors. We have analysed demographic factors by contrasting intermarker LD results obtained in a large cosmopolitan population (UK), a large genetic isolate (Sardinia) and a subisolate (village of Gavoi) for two regions of the X chromosome. A dramatic increase of LD was found in the subisolate. Demographic history of populations therefore influences LD. Chromosome-region-specific effects, namely the pattern and frequency of homologous recombination, were next delineated by the analysis of chromosome 6p21, including the HLA region. Patterns of global LD in this region were very similar in the UK and Sardinian populations despite their entirely distinct demographies, and correlate well with the pattern of recombinations. Nevertheless, haplotypes extend across recombination hot spots indicative of selection of certain haplotypes. Subisolate aside, chromosome-region-specific differences in LD patterns appear to be more important than the differences in intermarker LD between distinct populations.

Chromosomes, Human, Pair 6↗
PubMed2004

Selection versus demography: a multilocus investigation of the domestication process in maize.

The domestication of maize (Zea mays ssp. mays) from its wild ancestor (Zea mays ssp. parviglumis) led to a loss of genetic diversity both through a population bottleneck and through directional selection at agronomically important genes. In order to discriminate between those effects and to investigate the nature of the domestication bottleneck, we analyzed nucleotide diversity data from 12 chromosome 1 loci in parviglumis. We found an average loss of nucleotide diversity of 38% across genes, but this average was skewed downward by four putatively selected loci (tb1, d8, ts2, and zagl1). To better understand the domestication process, we used the coalescent with recombination to simulate bottlenecks under various lengths and population sizes. For each locus, we determine the likelihood of the observed data using three summary statistics: the number of segregating sites, an estimate of the population recombination parameter, and Tajima's D. Based on the eight neutrally evolving loci, a model with a bottleneck had a significantly higher likelihood than a model without one. The four putatively selected loci had significantly different likelihood optimums than the neutral loci, and this approach confirmed that ts2 and d8 were selected either during domestication or breeding. Overall, the best-fitting models had a bottleneck in which the population size and the bottleneck duration had a ratio of approximately 4- to approximately 5; for example, if the initial domestication event occurred over a 500-year period, the population size was roughly 2,000 to 2,500 individuals. However, this range did vary with the summary statistic used to assess the fit of simulations to data. In this context, Tajima's D performed poorly as a goodness-of-fit statistic, probably because Z. mays ssp. parviglumis has a frequency spectrum that is significantly skewed toward low-frequency variants. Finally, we found that demography is unlikely to account for the previously observed positive correlation between nucleotide diversity and the population-recombination parameter in maize, leaving this observation difficult to interpret.

Amino Acid Sequence↗
PubMed2004

Disentangling the effects of demography and selection in human history.

Demographic events affect all genes in a genome, whereas natural selection has only local effects. Using publicly available data from 151 loci sequenced in both European-American and African-American populations, we attempt to distinguish the effects of demography and selection. To analyze large sets of population genetic data such as this one, we introduce "Perlymorphism," a Unix-based suite of analysis tools. Our analyses show that the demographic histories of human populations can account for a large proportion of effects on the level and frequency of variation across the genome. The African-American population shows both a higher level of nucleotide diversity and more negative values of Tajima's D statistic than does a European-American population. Using coalescent simulations, we show that the significantly negative values of the D statistic in African-Americans and the positive values in European-Americans are well explained by relatively simple models of population admixture and bottleneck, respectively. Working within these nonequilibrium frameworks, we are still able to show deviations from neutral expectations at a number of loci, including ABO and TRPV6. In addition, we show that the frequency spectrum of mutations--corrected for levels of polymorphism--is correlated with recombination rate only in European-Americans. These results are consistent with repeated selective sweeps in non-African populations, in agreement with recent reports using microsatellite data.

ABO Blood-Group System↗
PubMed2005

Inferring the effects of demography and selection on Drosophila melanogaster populations from a chromosome-wide scan of DNA variation.

Identifying regions of the Drosophila melanogaster genome that have been recent targets of positive Darwinian selection will provide evidence for adaptations that have helped this species to colonize temperate habitats. We have begun a search for such genomic regions by analyzing multiple loci (about 250) dispersed across the X chromosome in a putatively ancestral population from East Africa and a derived European population. For both populations we found evidence for past changes in population size. We estimated that a major bottleneck associated with the colonization of Europe occurred about 3,500-16,000 years ago. We also found that while this bottleneck can account for most of the reduction in variation observed in the European sample, there is a deficit of polymorphism in some genomic regions that cannot be explained by demography alone.

Africa↗