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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↗

Equal dependence of the high prevalence of health problems on age and family income in rural southern areas.

BACKGROUND: People who have periods of low family income are at risk for increased health problems in the future, even if they present a similar clinical picture before the reduction in family income. The association between low income and health status was studied in residents of an area with relatively low-average family income and with a historically unstable economy. METHODS: We surveyed a stratified, clustered sample of residents of Johnson County, Tennessee, using a structured interview. The responses were analyzed in conjunction with national and regional data (National Health Interview Survey). RESULTS: Residents of the geographic area under study had a markedly higher prevalence of self-reported health problems than either the national average or rural areas in the southeast United States. The higher prevalence was accounted for by the combination of age and family income, which had equal effects on health status, but not by age differences alone. CONCLUSIONS: Family income and economic development are critically important to improving community health. Sensible capitation rates in managed care arrangements can be obtained only if the income distribution of an insured population is considered along with their age, sex, and physical health status.

Adolescent↗

The use of model life tables to estimate mortality for the United States in the late nineteenth century.

This paper seeks to extend our knowledge about mortality in the late nineteenth century United States by using census mortality data for older children and teenagers to fit model tables. The same method can also be used with partially underregistered death data. The most commonly used model tables, the Coale and Demeny West Model, apparently do not adequately depict the changing shape of mortality over the period 1850--1910. An alternative model life table system is presented, based on the Brass two parameter logit system and available reliable life tables from the period 1850--1910. The two parameter system must be reduced to a one parameter system by means of estimated relationships between the parameters so that the fitting procedure can be used. The resulting model system is, however, heavily dependent on the experience of northern, industrial states, especially Massachusetts.

Actuarial Analysis↗

Survival and expectation of life from the 1400's to the present. A study of the Knighthood Order of the Golden Fleece.

The author used standard methods for the analysis of retrospective cohort studies, to investigate survival and life expectancy at age 25 years and older in 1,282 European noblemen who had been members of the Knighthood Order of the Golden Fleece between its foundation in 1430 and the early 1960's. This experience was compared with figures published for British peerage families since the 1600's and with Dutch population figures of the 1980's. For all ages, there was a gradual increase in survival and life expectancy from the 1700's onward, continuing until the present.

Adult↗

Profile of home care aides, nursing home aides, and hospital aides: historical changes and data recommendations.

PURPOSE: To examine demographic characteristics and work conditions of home care aides, nursing home aides, and hospital aides in the late 1980s and late 1990s. DESIGN AND METHODS: This study replicated a previous study which examined the Current Population Survey (CPS) March supplement from 1987 to 1989. The present study examined CPS data from 1997 to 1999 both to obtain a profile of aides in the late 1990s and to compare 1990's work conditions and demographic characteristics with those of aides in the late 1980s. RESULTS: Whereas demographic characteristics and work conditions of hospital and nursing home aides show little change over the decade, home care aides today are generally younger, more educated, more likely to hold full-time positions, and more likely to have health benefits than their counterparts 10 years ago. Yet work conditions are still poorer for home care aides than for the other types of aides. IMPLICATIONS: Work conditions need further improvement, particularly for home care aides. More accurate data to describe paraprofessional care workers are also necessary to address the serious worker shortage problems.

Adult↗

Heterogeneity of long-distance migration in studies of genetic structure.

One of the assumptions of migration matrix methods of population structure is that long-distance migrants are all sampled from a genetically homogeneous 'outside world'. This assumption has not often been tested. This paper examines migration and surname data from four towns in historical Massachusetts in order to examine this assumption and potential genetic effects of heterogeneous long-distance migration. Analysis of migration data shows that the rate of long-distance migration is significantly different for the four towns. The distributions of source populations for long-distance migrants into each town are significantly different. Surname analysis shows that in spite of the violation of the assumption of long-distance migrant homogeneity, there is little effect on the degree and pattern of within-group and among-group variation for these towns. This lack of effect seems related to genetic homogeneity of the long distance migrants.

Emigration and Immigration↗

Sociodemographic differences in use of preventive services by women enrolled in Medicare+Choice plans.

BACKGROUND: We examined the effect of sociodemographic factors on the receipt of mammography, colorectal cancer screening, and influenza vaccinations by women enrolled in two Medicare+Choice health plans. METHODS: Administrative and survey data for 2,698 female health plan members was analyzed using multivariate logistic and ordinal logistic regression to assess the effects of enrollee characteristics on use of preventive services. RESULTS: Age, race and wealth were associated with the receipt of one or more preventive services. Older women were less likely to receive mammograms, wealthier women were more likely to receive mammograms and CRC screening, and Black women were more likely to receive CRC screening but less likely to receive influenza vaccinations. Wealthier women received a greater number of preventive services, other things equal, while older women received fewer preventive services. CONCLUSIONS: Race and wealth continue to be important factors in the receipt of preventive services by elderly women, though not always consistent with historical trends. Medicare+Choice plans should consider strategies to further reduce racial and wealth disparities in the use of preventive services.

Aged↗

Biogeography and decline of rare plants in New England: historical evidence and contemporary monitoring.

Detecting range shifts and contractions is critical for determining the conservation priority of rare and declining taxa. However, data on rare species occurrences frequently lack precise information on locations and habitats and may present a biased picture of biogeographic distributions and presumed habitat preferences. Herbarium or museum specimen data, which otherwise could be useful proxies for detecting temporal trends and spatial patterns in species distributions, pose particular challenges. Using data from herbaria and Natural Heritage Programs on numbers of occurrences within individual municipalities (towns, cities, or townships), we quantified temporal changes in the estimated distributions of 110 rare plant species in the six New England (USA) states. We used the partial Solow equation and a nonparametric test to estimate the probability of observing multiple absences (gaps in the collection record) if a given population was actually still extant. Bayes' Theorem was used to estimate the probability that occurrences were misclassified as extinct. Using the probabilities obtained from these three methods, we eliminated taxa with high probabilities of pseudo-absence (that would yield an inaccurate profile of species distributions), narrowing the set for final analysis to 71 taxa. We then expressed occurrences as centroids of town polygons and estimated current and historical range areas (extents of occurrence as defined by alpha-hulls inscribing occurrences), mean distances between occurrences, and latitudinal and longitudinal range boundaries. Using a geographic information system, we modeled first, second, and third circular standard deviational polygons around the mean center of the historical range. Examining the distribution of current occurrences within each standard deviational polygon, we asked whether ranges were collapsing to a center, expanding, fragmenting, or contracting to a margin of the former range. Extant ranges of the species were, on average, almost 67% smaller than their historical ranges, and distances among occurrences decreased. Five New England hotspots were observed to contain >35% of rare plant populations. Extant occurrences were more frequently marginalized at the periphery of the historical range than would be expected by chance. Coarse-grained data on current and historical occurrences can be used to examine large suites of species to prioritize taxa and sites for conservation.

Conservation of Natural Resources↗

Mortality in a migrating Mennonite church congregation.

Preston's two-census method of demographic estimation is applied to three pairs of reconstructed censuses from the records of a migrating Mennonite church congregation covering the period 1780-1890. The three pairs of censuses correspond to three periods (1780-1790, 1850-1860, and 1880-1890) and to stays in three settings (Prussia, Russia, and Kansas, respectively). The Mennonites' stay in Prussia was a period of hardship. In Russia they expanded their economic base and developed new farming methods, dramatically increasing their productivity. The Mennonites took these skills to Kansas, where they continued to be successful. The increase in life expectancy at age 5 corroborates this picture. The Prussian period exhibits the shortest life expectancy for both sexes. After the move to Russia, life expectancy increased for both sexes and continued to increase with the move to Kansas. The model also provides limited evidence for fertility depression following the move to Kansas.

Adolescent↗

Phylogeography of the cyprinid Squalius aradensis and implications for conservation of the endemic freshwater fauna of southern Portugal.

The Iberian cyprinid fauna, characterized by the presence of numerous endemic species, has suffered from significant habitat degradation. The critically endangered Squalius aradensis is restricted to small drainages of southern Portugal, habitats that typically exhibit a characteristic Mediterranean-type heterogeneous hydrological system throughout the year, including alternation of flooding events during winter and complete drought in large river sections during summer. To assess the effect of historical and recent processes on genetic diversity in S. aradensis we examined within- and among-population variability in cytochrome b and six polymorphic microsatellite loci. Estimates of genetic diversity in time and space through the combined use of traditional Phi-/F-statistics, phylogenetic trees, ordination methods and nested clade analysis indicated significant and congruent structuring among populations. Data suggest that the Arade drainage represent the evolutionary centre of the species, with subsequent allopatric fragmentation across drainages. Factors other than isolation by distance strongly affected the within-drainage genetic differentiation observed in these Mediterranean-type drainages, including recent population expansion from a bottleneck event and restricted gene flow imposed by a long-term barrier (brackish water area). Significant correlation was found between S. aradensis allelic diversity and upstream drainage area. The relevance of findings for conservation issues is discussed in relation to local intermittent hydrological conditions, the highly restricted distribution and the critically endangered status of the species.

Animals↗

Phylogeny and historical biogeography of African ground squirrels: the role of climate change in the evolution of Xerus.

We used phylogenetic and phylogeographical methods to infer relationships among African ground squirrels of the genus Xerus. Using Bayesian, maximum-parsimony, nested clade and coalescent analyses of cytochrome b sequences, we inferred interspecific relationships, evaluated the specific distinctness of Cape (Xerus inauris) and mountain (Xerus princeps) ground squirrels, and tested hypotheses for historical patterns of gene flow within X. inauris. The inferred phylogeny supports the hypothesized existence of an 'arid corridor' from the Horn of Africa to the Cape region. Although doubts have been raised regarding the specific distinctness of X. inauris and X. princeps, our analyses show that each represents a distinct well-supported, monophyletic lineage. Xerus inauris includes three major clades, two of which are geographically restricted. The distributions of X. inauris populations are concordant with divergences within and disjunctions between other taxa, which have been interpreted as results of Plio-Pleistocene climate cycles. Nested clade analysis, coalescent analyses, and analyses of genetic structure support allopatric fragmentation as the cause of the deep divergences within this species.

Africa↗

Nested Admixture During and After the Trans-Atlantic Slave Trade on the Island of São Tomé.

Human genetic admixture, involving the contact between two or more previously isolated populations, can be a complex process influenced by social dynamics. In this study, we aim to reconstruct complex admixture histories in São Tomé, an island in the Gulf of Guinea where the Portuguese established one of the first plantation-based slave societies. Since the 15th century, migration waves from Africa and Europe, slavery, marooning, and indentured labour led to profound demographic shifts and social stratification on the island. Examining 2.5 million SNPs newly genotyped in 96 São Toméans, we observed patterns of genetic differentiation that were more complex than those of other populations descended from enslaved Africans on either side of the Atlantic. Using local ancestry inference and Identical-by-Descent methods, we identified five genetic clusters in São Tomé and reconstructed shared ancestries between each cluster and 70 African and European population samples, including an extensive sample from the Cabo Verde archipelago. Our findings align with historical records, retracing the major slave trade routes and labour-driven migrations after the abolition of slavery. We also identified gene flow between recently admixed groups that were previously isolated on the island. We call this process, creating multiple layers of genetic ancestry in admixed genomes, nested admixture. We suggest that changing social structures in São Tomé transformed the genetic structure of its population and influenced the admixture process. This study demonstrates how successive admixture and isolation events during and after the Trans-Atlantic Slave Trade shaped extant genetic diversity patterns at local scale in Africa.

Humans↗

Epidemiological transition of mortality curves in terms of the Brass logit system.

"The purpose of this paper is to examine the long-term trends of life tables in developed countries according to two parameters of the Brass system in order to find the range of variation, consistent with historical life tables (or, in other words, to define 'a field of epidemiological transition')." The author finds that "1) In the past, the mortality curves had U- and J-shapes, the latter being connected with the impact of demographic crises....2) The elimination of the crisis component at the first stage of the transition resulted in the transformation of the mortality curves towards the U-shape....3) At the second stage social control is established over premature mortality. As a result, life expectancy grows, and the shape of the curves moves towards the J-shape....4) In the past the male and female life tables usually did not differ from each other as regards the value of the Brass model parameters. However, in the last 30-40 years considerable sexual differences emerged both in the level and in the shape of the mortality curves." (SUMMARY IN FRE)

Demography↗

Reclassifying causes of death to study the epidemiological transition in the Netherlands,1875-1992.

"This article describes a method for reclassifying causes of death in the Netherlands for the period 1875-1992....A method developed by Vallin and Mesle (1988), which involves ¿dual correspondence tables' and ¿fundamental associations', was used to create nosologically continuous categories. These categories were tested for statistical continuity during the transition years of one ICD-revision [International Classification of Diseases] to the next, using ordinary least squares regression analysis. The reclassification procedure resulted in a nested classification consisting of three levels of refinement of causes of death: 27 causes, 1875-1992; 65 causes, 1901-1992; and 92 causes, 1931-1992. On the basis of this classification, 43% of all deaths in 1875-79 and 98% of all deaths in 1992 could be allocated to either communicable diseases, non-communicable diseases or external causes." (SUMMARY IN FRE)

Cause of Death↗

The prevalence of self-reported peptic ulcer in the United States.

OBJECTIVES: The purpose of this study was to draw a current picture of the sociodemographic characteristics of peptic ulcer in the United States. METHODS: During the National Health Interview Survey of 1989, a special questionnaire on digestive diseases was administered to 41,457 randomly selected individuals. Data were retrieved from public use tapes provided by the National Center for Health Statistics. Odds ratios were calculated by logistic regression after adjustment for sample weights in the survey. RESULTS: Of adult US residents, 10% reported having physician-diagnosed ulcer disease, and one third of these individuals reported having an ulcer in the past year. Old age, short education, low family income, being a veteran, and smoking acted as significant and independent risk factors. Gastric and duodenal ulcer occurred in both sexes equally often. Duodenal ulcer was more common in Whites than non-Whites, while gastric ulcer was more common in non-Whites. CONCLUSIONS: The age-related rise and socioeconomic gradients of peptic ulcer represent the historic scars of previous infection rates with Helicobacter pylori. The racial variations reflect different ages at the time of first infection; younger and older age at the acquisition of H. pylori appear to be associated with gastric and duodenal ulcer, respectively.

Adolescent↗

Social democratic government and spatial distribution of health care facilities. The case of hospital beds in Germany.

BACKGROUND: In this paper, the hypothesis that the spatial distribution of hospital beds is more even in countries with socialist or social democratic governments than in countries with conservative or Christian democratic governments was tested. To avoid the confounding influences of historical and institutional differences between countries, we used the Federal Republic of Germany as a case study. The German federal states have their own governments who play an important role in creating structures for the planning of hospital facilities. METHODS: The test of the hypothesis was largely quantitative. At the level of federal states the rank correlation was computed between the weighted number of years of left-wing government participation and the coefficient of variation in the number of hospital beds per 1000 inhabitants. In addition to this, the hospital plans of two federal states were studied. RESULTS: The hypothesis was supported by the data, showing a positive association between the number of years of left-wing government participation and regional variation in the number of hospital beds. A comparison of the hospital plans of two contrasting federal states showed less government interference in hospital planning in the state with a tradition of right-wing government. CONCLUSION: There seems to be a relation between left-wing government participation in West German states and a more equal distribution of the number of hospital beds per 1,000 inhabitants.

Democracy↗

Breast-feeding and family planning: a review of the relationships between breast-feeding and family planning.

A number of interrelated factors must be considered when breast-feeding is introduced as a concern for family planning programs: the number of pregnancies and births experienced, age at each pregnancy and birth, duration of the intervals between conceptions, lactation including duration and type, health and nutritional services available to meet the demands of pregnancy, delivery, and postpartum care. The dietary intake of the mother and her health and disease status have an effect on the duration of breast-feeding, and lactation has an effect on her ovulation and birth spacing. Those at particularly high risk include adolescent girls, older grand-multipara women, and families living in poverty. An historical relationship between the reduction in infant and childhood mortality and the falling off of births can be documented. The straightforward benefits on nutritional status of breast-fed infants, the conjunction with the antibody protection afforded by breast milk, served to reduce infant mortality and indirectly served to reduce birth rates. In addition, the prolongation of postpartum anovulatory cycles in breast-feeding women, coupled with sexual mores that postpone sexual relations while a women is breast-feeding in certain groups, will serve to prolong the interbirth intervals. Populations where breast-feeding is customary have been shown to have fewer births than populations where the women do not breast-fed and where infants are artificially fed.

Age Factors↗

Habitat barriers limit gene flow and illuminate historical events in a wide-ranging carnivore, the American puma.

We examined the effects of habitat discontinuities on gene flow among puma (Puma concolor) populations across the southwestern USA. Using 16 microsatellite loci, we genotyped 540 pumas sampled throughout the states of Utah, Colorado, Arizona, and New Mexico, where a high degree of habitat heterogeneity provides for a wide range of connective habitat configurations between subpopulations. We investigated genetic structuring using complementary individual- and population-based analyses, the latter employing a novel technique to geographically cluster individuals without introducing investigator bias. The analyses revealed genetic structuring at two distinct scales. First, strikingly strong differentiation between northern and southern regions within the study area suggests little migration between them. Second, within each region, gene flow appears to be strongly limited by distance, particularly in the presence of habitat barriers such as open desert and grasslands. Northern pumas showed both reduced genetic diversity and greater divergence from a hypothetical ancestral population based on Bayesian clustering analyses, possibly reflecting a post-Pleistocene range expansion. Bayesian clustering results were sensitive to sampling density, which may complicate inference of numbers of populations when using this method. The results presented here build on those of previous studies, and begin to complete a picture of how different habitat types facilitate or impede gene flow among puma populations.

Animals↗