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PubMedDate not supplied

Genetic structure and population history of Ireland: a comparison of blood group and anthropometric analyses.

Population structure and history may be studied on a local or a regional level. This paper examines the regional population structure of the Republic of Ireland and Northern Ireland with respect to population history and demographic processes. Blood-group and anthropometric data obtained from the literature are analysed. The blood-group data consist of ABO and Rhesus gene frequencies for 32 counties and the Aran Islands. Anthropometric data consist of summary statistics for 15 variables collected from 19 regions. The degree and pattern of population differentiation is assessed using new methods of population-structure analysis. Both blood group and anthropometric analyses show a west-east division of populations corresponding to the known history of inhabitation of Ireland, where successive waves of immigrants pushed earlier populations further west. In both analyses there were two deviations to this basic pattern: the Aran Islands and the midlands. In both cases, alternative historical explanations are examined. The genetic relationship of the Aran Islands to the rest of Ireland and England appears to be due to English admixture following the garrisoning of soldiers several centuries ago. The genetic position of the midlands is more complex, but suggests the effects of early Viking inhabitation. These findings are related to studies of the local, rather than regional, population structure of Ireland.

Anthropometry↗

PubMed1999

How many elders receive assistance? A cross-national comparison.

OBJECTIVES: To examine models of informal support received by elders in the United States and Sweden and to test whether differences in informal support appear to stem from demographic differences between the nations alone or whether cultural and historical differences must also be considered. METHODS: Samples with similar functional dependence, age 75 and older in the United States (n = 4,677) and Sweden (n = 1,378), were used to model cross-national differences in the association between country, age, sex, potential availability of kin support, and receipt of informal assistance. RESULTS: Patterns of informal help were higher in the United States than in Sweden but were qualified by higher order interactions among age, sex, and availability of kin support. DISCUSSION: Cultural differences predating current policies in both countries appear to influence informal support over and above what can be accounted for by demographic differences alone.

Age Factors↗

PubMed1983

A stochastic diffusion model of the time path of nuptiality.

"The time path of nuptiality is approximated by means of the log normal diffusion process. The drift coefficient is estimated by the method of maximum likelihood. Swedish and Canadian data on nuptiality have been utilised to illustrate the model. A piece-wise fitting of the log-normal model to the Swedish data reveals that the drift coefficient is changing over time. The use of mixing distribution is suggested to remedy this problem. On the whole the Hajnal theory of nuptiality transition is supported. It is also seen that the Hajnal transition is one in a series of transitions."

Americas↗

PubMed1984

Measuring gene flow among populations having high levels of genetic fragmentation.

We present an analysis of the genetic structures of 22 species of salamanders, with regard to levels of gene flow among populations. We estimate the gene flow parameter, Nm (the product of the effective population number and rate of migration among populations) using two alternative methods described by Wright and Slatkin. For most species, these two methods give approximately congruent estimates of Nm; when estimates differ, the method of Wright produces values slightly larger than those derived by the method of Slatkin. We analyze these results in light of independently derived historical inferences of the fragmentation of populations. This analysis suggests that the Nm values calculated from protein polymorphisms may contain information more relevant to historical patterns of gene exchange than to the current population dynamics; moderately large values of Nm may be calculated for species containing populations known to be no longer exchanging genes. Application of a method for estimating the maximum possible rate of gene exchange among populations indicates that, for most species studied here, gene flow among populations probably is no greater than the mutation rate. We suggest that most plethodontid species cannot be viewed as units whose cohesion is maintained by continuing gene exchange. Furthermore, we suggest that phenotypic uniformity among populations is not easily explained by hypotheses of continual stabilizing selection and propose that future work concentrate upon clarification of the genetic and epigenetic factors conferring self-maintenance or autopoietic properties on living systems.

Alleles↗

PubMedDate not supplied

Estimates of net migration by age at migration from pairs of enumerations of the foreign born: United States, 1880-1930.

"This paper describes a new method for indirectly estimating age schedules of net migration. The method is illustrated with historical data for the United States. The analysis employs a recently developed technique--iterative intracohort interpolation--to estimate age schedules of net migration from pairs of enumerations of the foreign born by age. The data required for this application are enumerations of the foreign born (or more generally of those born outside the enumeration area) by age in two successive censuses, a life table presumed to reflect the mortality experience of the foreign born during the intercensal period, and, optionally, data on variations in the overall level of migration during the intercensal period. The procedure provides estimates of the average annual number of foreign born net migrants during a decade by their age at the time of entry/exit." (SUMMARY IN ITA AND FRE)

Age Distribution↗

PubMed2006

Does adherence monitoring reduce controlled substance abuse in chronic pain patients?

BACKGROUND: Opioids are used extensively for chronic pain management in the United States. The frequency of opioid use prior to presenting to interventional pain management settings and in interventional pain management settings has been shown to be above 90%. Given that controlled substance abuse and illicit drug use are prevalent phenomena, adherence monitoring of patients that are prescribed opioids is becoming common. Adherence monitoring is carried out by an appropriate history, periodic evaluation of appropriate intake of drugs, random drug testing, and pill counts. Crucial to adherence monitoring is an initial controlled substance agreement and repeated review of the terms of this agreement with on-going education. However, the effect of adherence monitoring on drug abuse is unclear. OBJECTIVE: To identify controlled substance abuse through implementation of the terms of a controlled substance agreement, including periodic review and monitoring outside the organization. STUDY DESIGN: Prospective evaluation with historical controls. METHODS: Five hundred consecutive patients receiving prescription controlled substances were followed in a prospective manner. The evaluation consisted of a chart review to monitor controlled substance intake, with special attention to drugs obtained from outside the organization. Data collection for this purpose included information from records, pharmacies, referring physicians, and all the physicians involved in the treatment of the patient. RESULTS: Results from 500 consecutive patients were evaluated. Controlled substance abuse was seen in 9% of patients; overall, 5% of patients were obtaining controlled substances from other physicians, and 4% from illegal sources. CONCLUSION: Adherence monitoring, including controlled substance agreements and various periodic measures of compliance was associated with a 50% reduction in opioid abuse.

Analgesics, Opioid↗

PubMed2005

Genetic diversity and historical demography of Atlantic bigeye tuna (Thunnus obesus).

Bigeye (Thunnus obesus) is a large, pelagic, and migratory species of tuna that inhabits tropical and temperate marine waters worldwide. Previous studies based on mitochondrial RFLP data have shown that bigeye tunas from the Atlantic Ocean are the most interesting from a genetic point of view. Two highly divergent mitochondrial haplotype clades (I and II) coexist in the Atlantic Ocean. One is almost exclusive of the Atlantic Ocean whereas the other is also found in the Indo-Pacific Ocean. Bigeye tuna from the Atlantic Ocean is currently managed as a single stock, although this assumption remains untested at the genetic level. Therefore, genetic diversity was determined at the mitochondrial control region to test the null hypothesis of no population structure in bigeye tuna from the Atlantic Ocean. A total of 331 specimens were sampled from four locations in the Atlantic Ocean (Canada, Azores, Canary Islands, and Gulf of Guinea), and one in the Indian and Pacific Oceans, respectively. The reconstructed neighbor-joining phylogeny confirmed the presence of Clades I and II throughout the Atlantic Ocean. No apparent latitudinal gradient of the proportions of both clades in the different collection sites was observed. Hierarchical AMOVA tests and pairwise phi(ST) comparisons involving Atlantic Ocean Clades I and II were consistent with a single stock of bigeye tuna in the Atlantic Ocean. Population genetic analyses considering phylogroups independently supported gene flow within Clade II throughout the Atlantic Ocean, and within Clade I between Atlantic and Indo-Pacific Oceans. The latter result suggests present uni-directional gene flow from the Indo-Pacific into the Atlantic Ocean. Moreover, mismatch analyses dated divergence of Clades I and II during the Pleistocene, as previously proposed. In addition, migration rates were estimated using coalescent methods, and showed a net migration from Atlantic Ocean feeding grounds towards the Gulf of Guinea, the best-known spawning ground of Atlantic bigeye tuna.

Animals↗

PubMed1996

Genetic studies in Medzev, an isolate in south-eastern Slovakia. 1. History, demography, marriage patterns.

In Medzev, a village located in South-Eastern Slovakia, the secular variation of two indices of genetic isolation has been studied. It could be seen that this village was highly isolated till the beginning of the 20th century. Both indices show a tendency to increase in the first five decades of this century. For the entire period from 1766-1950 the coefficient of inbreeding estimated by the method of isonymy was found to be F = 0.0074 with different ratios of random (Fr) and non-random (Fn) components in particular periods. The coefficient of inbreeding estimated from the ecclesiastical dispensations for marriages comes to F = 0.0019. The genetic significance of the changes in the population structure of this village will be analyzed in further studies.

Ethnicity↗

PubMed2006

Changes in the natural history of renal cancer: comparison of Estonian data from the periods 1986-1988 and 1996-1998.

To explain considerable increase in survival of renal cancer patients in Estonia during last decades, we compared the stage distribution, diagnostic and treatment methods for the patient groups diagnosed in the periods 1986-1988 and 1996-1998. A significant difference in stage distribution was detected with an increase for stages I-II and a decrease for stages III-IV in 1996-1998. There was a shift in primary diagnostic methods from intravenous urography and angiography to ultrasonography and computed tomography. In multivariate analysis the independent prognostic factors for overall survival were age, stage, and operation status. In conclusion, the increase in the survival of renal cancer patients has been due to the larger number of cases with the earlier stage, which is associated with the application of ultrasonography and computed tomography. Another factor for better survival was the higher operation rate among patients with stage IV disease, a possible factor was the change in operation techniques.

Demography↗

PubMedDate not supplied

The second dimension: a proposed measure of the rectangularity of mortality curves.

"The present paper proposes a measure of the shape (rectangularity) of the mortality curve which is statistically orthogonal to (independent of) the level of mortality over a broad range of national life tables, both historical and contemporary.... We have proposed [using]...a ratio of survival probabilities in two broad age ranges, in middle and young adulthood. It is suggested that this measure is an effective first approximation, which can be built on both methodologically and substantively, in order to obtain a better understanding of the social and other conditions producing rectangular and troughed mortality curves." Data for selected developed countries are used to test the model. (SUMMARY IN FRE AND ITA)

Age Factors↗

PubMed1992

[Fertility of women married before 1800 at Jablonec nad Nisou].

Using data from parish registers and family reconstitution methods, the authors analyze fertility levels and trends for women married before 1800 in the town of Jablonec nad Nisou, Czech Republic. "Analyzing matrimonial fertility of these families we have found...that during the whole 18th century the level of matrimonial fertility...was stable.... The number of children in a family depended on the age of woman at the time of marriage and length of marriage duration." (SUMMARY IN ENG AND RUS)

Birth Rate↗

PubMedDate not supplied

A simulation model to estimate the cost and effectiveness of alternative dialysis initiation strategies.

BACKGROUND: Patients with end-stage renal disease (ESRD) require dialysis to maintain survival. The optimal timing of dialysis initiation in terms of cost-effectiveness has not been established. METHODS: We developed a simulation model of individuals progressing towards ESRD and requiring dialysis. It can be used to analyze dialysis strategies and scenarios. It was embedded in an optimization frame worked to derive improved strategies. RESULTS: Actual (historical) and simulated survival curves and hospitalization rates were virtually indistinguishable. The model overestimated transplantation costs (10%) but it was related to confounding by Medicare coverage. To assess the model's robustness, we examined several dialysis strategies while input parameters were perturbed. Under all 38 scenarios, relative rankings remained unchanged. An improved policy for a hypothetical patient was derived using an optimization algorithm. CONCLUSION: The model produces reliable results and is robust. It enables the cost-effectiveness analysis of dialysis strategies.

Aged↗

PubMed2006

Gender-specific trends in educational attainment and self-rated health, 1972-2002.

OBJECTIVES: We tested whether self-rated health has improved over time (1972-2002) for women and men. We also considered the degree to which historical gains in educational attainment help to explain any observed trends. METHODS: Using 21 years of repeated cross-sectional data from the General Social Survey, we estimated a series of ordered logistic regression models predicting self-rated health. RESULTS: Our results show that women's health status has steadily improved over the 30-year period under study, and these improvements are largely explained by gains in educational attainment. We also found that the health trend for men is nonlinear, suggesting significant fluctuations in health status over time. CONCLUSIONS: Based on the linear health status trend and strong mediation pattern for women, and the nonlinear health status trend for men, women have benefited more than men, in terms of self-rated health, from increased educational attainment.

Adult↗

PubMed1991

A hazard model analysis examining inferential evidence of migration from the Port-city of Viana do Castelo, Minho, 1834-1931.

"This paper is an attempt to analyse the determinants of out-migration of the elite from the Portuguese city of Viana do Castelo [from 1834-1931]. The data used are derived from a reconstruction of this electorate using record linkage methods. Indirect evidence of emigration is available from passport books, and evidence of death is available with cemetery lists. The paper discusses methodological issues in the estimation of hazard models of duration spent under observation in the elite. The analysis suggests that, while out-migration was not significantly dependent on age, or marital status, there were large occupational differentials, and significant period effects." (SUMMARY IN FRE)

Age Factors↗

PubMed2002

Incidence and prediction of falls in Parkinson's disease: a prospective multidisciplinary study.

OBJECTIVES: To accurately establish the incidence of falls in Parkinson's disease (PD) and to investigate predictive risk factors for fallers from baseline data. METHODS: 109 subjects with idiopathic PD diagnosed according to the brain bank criteria underwent a multidisciplinary baseline assessment comprising demographic and historical data, disease specific rating scales, physiotherapy assessment, tests of visual, cardiovascular and autonomic function, and bone densitometry. Patients were then prospectively followed up for one year using weekly prepaid postcards along with telephone follow up. RESULTS: Falls occurred in 68.3% of the subjects. Previous falls, disease duration, dementia, and loss of arm swing were independent predictors of falling. There were also significant associations between disease severity, balance impairment, depression, and falling. CONCLUSIONS: Falls are a common problem in PD and some of the major risk factors are potentially modifiable. There is a need for future studies to look at interventions to prevent falls in PD.

Accidental Falls↗

PubMedDate not supplied

Genealogical data and the biodemography of human longevity.

Biodemography of human longevity is an emerging interdisciplinary field of sociobiological research with deep historical roots. Two research questions are examined in this article: (1) What evidence is there for the familial transmission of human longevity?, and (2) what are the effects of parental age at reproduction on offspring longevity, and in particular, are there long-term adverse health consequences associated with the trend toward delayed reproduction? The ability of scientists to conduct biodemographic studies depends not only on merging theoretical and methodological elements from the biological and demographic/actuarial sciences, but unique sources of data and statistical methods must also be developed. In this article we describe how gencalogical data have been used for over a century to explore basic questions about human longevity, and how similar kinds of data now being developed are driving the formation of new testable research hypotheses in the field of biodemography.

Demography↗

PubMed1985

Tracers for paralysis agitans in epidemiological research. III. Refinement of the model for estimation of the prevalence of the disease.

The study presents a refinement of a preliminary model for estimation of the prevalence of Parkinson's disease (PA) from information on sales of L-dopa derivatives (LDD) and demographic data. The new model made use of a set of age-specific equations describing PA prevalences obtained from historical surveys and local infant mortality rates (IMR). This strategy made it possible to obtain age-specific estimates of PA prevalence and adjust for differences in health services quality. The new model was tested using data from Sardinia and Iceland. The results are in agreement with the field surveys. When the model was tested in Sweden in 1983-1984 using data on age-specific consumption of LDD, the results also validated the model. The new refined model was found to be useful for estimation of age-specific prevalence from available data on total sales of LDD, the population and infant mortality rates.

Adolescent↗

PubMed1996

Estimating diaphyseal length from fragmentary subadult skeletal remains: implications for palaeodemographic reconstructions of a southern Ontario ossuary.

Fragmentary skeletal remains are a significant problem for osteologists attempting to reconstruct individuals or populations. This problem is further aggravated by sites yielding commingled remains, such as are recovered from the large protohistoric and historic ossuaries from southern Ontario, for which individual methods of age estimation and sex determination cannot be used concurrently. While some attention has been given to the estimation of long bone length from fragmentary, adult remains, little attention has been given to the equally important problem of fragmentary long bones in subadult assemblages. Analysis of data on diaphyseal length is a crucial aspect of reconstructing subadult palaeodemographic profiles, particularly for ossuary collections where dental remains are not associated with individuals and are often less represented than long bones. Such analysis also aids in the assessment of conditions of past population health. This study reports the results of several regression techniques used to estimate diaphyseal length from shaft-end breadths. Data collected from two southern Ontario ossuary samples were compiled to calculate the regression equations. Reliability of these equations and implications for palaeodemographic profiles are discussed.

Adolescent↗