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PubMed2006

Phylogeny, evolution, and biogeography of Asiatic Salamanders (Hynobiidae).

We sequenced 15 complete mitochondrial genomes and performed comprehensive molecular phylogenetic analyses to study the origin and phylogeny of the Hynobiidae, an ancient lineage of living salamanders. Our phylogenetic analyses show that the Hynobiidae is a clade with well resolved relationships, and our results contrast with a morphology-based phylogenetic hypothesis. These salamanders have low vagility and are limited in their distribution primarily by deserts, mountains, and oceans. Our analysis suggests that the relationships among living hynobiids have been shaped primarily by geography. We show that four-toed species assigned to Batrachuperus do not form a monophyletic group, and those that occur in Afghanistan and Iran are transferred to the resurrected Paradactylodon. Convergent morphological characters in different hynobiid lineages are likely produced by similar environmental selective pressures. Clock-independent molecular dating suggests that hynobiids originated in the Middle Cretaceous [ approximately 110 million years ago (Mya)]. We propose an "out of North China" hypothesis for hynobiid origins and hypothesize an ancestral stream-adapted form. Given the particular distributional patterns and our molecular dating estimates, we hypothesize that: (i) the interior desertification from Mongolia to Western Asia began approximately 50 Mya; (ii) the Tibetan plateau (at least on the eastern fringe) experienced rapid uplift approximately 40 Mya and reached an altitude of at least 2,500 m; and (iii) the Ailao-Red River shear zone underwent the most intense orogenic movement approximately 24 Mya.

Animals↗
PubMed1995

Service class migration in England and Wales, 1980-81: identifying gender-specific mobility patterns.

"Gendered patterns of service class migration were observed between the metropolitan counties and regional remainders within England and Wales using 1981 Census data. Observed flows were analysed in terms of the north-south migration divide and counterurbanization, and were compared to estimates derived from gravity models. More service class men than expected moved from metropolitan to non-metropolitan areas and between non-metropolitan areas. Women were less likely to move into non-metropolitan areas and were especially attracted to metropolitan destinations, notably London. These women were also more mobile within the South than service class men. It is suggested that these contrasting patterns reflect the differential geography of women's employment." (SUMMARY IN FRE AND GER)

Demography↗
PubMedDate not supplied

mtDNA sequences of Chadic-speaking populations from northern Cameroon suggest their affinities with eastern Africa.

BACKGROUND: No mitochondrial DNA (mtDNA) sequences from Chadic-speaking peoples have yet been reported, even though these populations inhabit a vast territory from eastern Nigeria to central Chad. This paper deals with the mtDNA sequences of four Central Chadic populations (Hide, Kotoko, Mafa and Masa) from northern Cameroon, biological samples from which were collected during anthropological research in the area of their homeland. OBJECTIVE: The main goals of this article are to report new mtDNA sequences of Chadic-speaking populations, to analyse their genetic diversity and to establish their relationships within the peri-Saharan area in respect of geography and languages. SUBJECT AND METHODS: The analyses are based on 104 mtDNA haplotypes, which can be localized into four different areas of northern Cameroon. Data collection was based on a strict geographical sampling strategy; the ethnonyms are retained here only for comparative purposes. RESULTS: None of the examined Chadic populations displays a departure from the normal mismatch distribution pattern, and the null hypothesis of the expansion event cannot be rejected. Analyses of molecular variance and F(ST) genetic distances revealed that the Chadic-speaking groups of northern Cameroon share more similarities with the populations of the Upper and Middle Nile Valley and East Africa than with populations from Central Africa. The results show geographical clustering to be more important than the correlation of linguistic affiliations with molecular genetic data. CONCLUSION: The observation that the Chadic group reveals some affinities to East Africans is extremely surprising giving the present-day geographical distance (around 2000 km) between them. These observations complement recent linguistic and archaeological findings, which consider the Chadic branch in the Afro-Asiatic phylum to be of eastern origin. A continuous, well-defined, geographic sampling strategy of the different genetic polymorphisms of the native populations of sub-Saharan Africa is further needed as the only way of understanding the differentiation of the mtDNA sequences at a micro-regional scale.

Africa↗
PubMedDate not supplied

Unifying susceptibility, exposure, and time: discussion of unifying analytic approaches and future directions.

This article reviews design and analysis concepts associated with the following major issues in air pollution epidemiology: (1) time-related determinants of health effects, including duration of exposure and disentangling acute effects and total life-shortening associated with long-term exposure; and (2) the role of geographies of susceptibility and exposure including the relevance and impact of ecologic covariates in the assessment of long-term effects of ambient air pollution. The article identifies the potential contribution associated with improved information in these areas to air pollution policy development and argues that these issues should frame future approaches to assessing the total effects of ambient air pollution.

Air Pollutants↗
PubMed2004

The geographic distribution of potential risks posed by industrial toxic emissions in the U.S.

The Toxics Release Inventory (TRI), compiled annually by the EPA, has emerged as the most comprehensive database on industrial toxic emissions in the U.S. While various risk indicators and pollutant weighting methods have been developed to compare TRI emissions, these measures are rarely used to examine the geography of potential risks posed by toxic emissions at the national scale. This article provides a geographic perspective on the evaluation of industrial pollution by exploring the spatial distribution of the potential health and environmental impacts of TRI emissions across the U.S. Six indicators of potential risk based on the impact benchmarking concept are used to characterize specific human health and environmental concerns: carcinogenic toxicity, noncarcinogenic toxicity, ozone depletion, global warming, smog formation and acid rain formation. Air emission data from the 2000 TRI are used to analyze the six potential impacts at the state level. The objectives are to: (a) examine and compare spatial variations in the distribution of these adverse impacts across the U.S.: and (b) identify the states facing the highest health and environmental risk from industrial toxic releases. The effect of differences in state area and population size on the distribution of the six potential impacts and state rankings for each category are also investigated. While Ohio and Texas receive the highest ranks in all risk categories, Louisiana and West Virginia represent the most "hazardous" states when emissions are weighted by state area and population. The results demonstrate the need to examine the geographic variability of different risk indicators that are used to evaluate TRI emissions, at multiple scales.

Air Pollutants↗
PubMed2004

Borderline science: expert testimony and the Red River boundary dispute.

The 1918 discovery of oil in the bed of the Red River, which forms the border between Texas and Oklahoma, led to a U.S. Supreme Court case that involved the extensive use of expert witnesses in fields such as geology, geography, and ecology. What began as a dispute between the two states soon became a multisided controversy involving those states, the federal government, Native Americans, and individual placer-mining claimants. After the federal attorneys introduced scientific experts into the dispute, including the plant ecologist Henry Chandler Cowles and the geographer Isaiah Bowman, fresh from negotiations at the Paris Peace Conference, Texas attorneys fielded their own team of opposing experts. Charged with the task of determining the location of the border, defined as the south bank of the river at the time of the 1819 treaty with Spain, the scientific experts presented the court with volumes of evidence and elaborate arguments, much of it contradictory and involving creative interpretations of existing theories. The case exhibited all the now-familiar features of a trial using expert witnesses, for which it represents an early, overlooked, and particularly complex example.

Dissent and Disputes↗
PubMed2005

A preliminary evaluation of a health monitoring programme in Hungary.

BACKGROUND: In 1998 a joint initiative of the Hungarian School of Public Health and the National Public Health Service created a network of sentinel stations based in primary care facilities in four Hungarian counties. The aim was to establish a system that will provide valid data on morbidity of selected diseases in Hungary. METHODS: Based on standardized protocols, the participating centres have continuously reported data on the prevalence of cardiovascular diseases, diabetes mellitus, liver cirrhosis, and some malignant diseases, as well as supplying denominator data. The four counties represent both eastern and western parts of Hungary, reflecting the known geographical disparities in health. Each county office enrolled general practitioners maintaining representation in terms of both geography and distribution of settlement size. RESULTS: A total of 73 general practitioners agreed to participate, providing care for 15.6% (138,088 people) of the population in the counties. The population registered with the practices were representative in terms of age and sex of both the participating counties and the entire country. The prevalence of hypertension, diabetes mellitus and liver cirrhosis is high in each county but varies considerably, with higher levels in the western counties, especially among older age groups of both sexes. CONCLUSIONS: The establishment of sentinel stations to collect morbidity data is feasible and sustainable in Hungarian primary care. The data that have been generated provide a valid and comprehensive picture of important aspects of the Hungarian population's health, with important implications for health policy and health service planning. In regions where low prevalence rates of diseases and high mortality rates simultaneously exist special attention is required to explore the background of this caveat. KEY POINTS: Till the end of 1998 no program operated in Hungary engaged with non-communicable disease morbidity data collection, except some hospital-based registries, which failed to produce reliable information. The establishment of sentinel stations to collect morbidity data is feasible and sustainable in Hungarian primary care, the valid morbidity data can be built into the decision making process in health service planning. Regular training, quality control and feedback are important contributors to the success of the program. The prevalence of hypertension, diabetes mellitus and liver cirrhosis is high in each county but varies considerably, with higher levels in the western counties, especially among older age groups of both sexes. More research needed to determine the possible contribution of unknown morbidity and health service utilisation to the different prevalence values in the two parts of Hungary.

Adolescent↗
PubMed2003

Directions in environmental gerontology: a multidisciplinary field.

This article considers developments and directions for environmental gerontology drawing on the three papers in this Forum. The multidisciplinary field came of age during the 1960s with Powell Lawton's powerful environmental press paradigm and its applications to empirical research and building design. Recent theoretical developments in Europe and America have advanced and integrated concepts in psychology, geography, and related disciplines. Time dimensions and active use of space are essential for understanding aging individuals and microenvironments as well as changing populations and macroenvironments. Research on residential environments by health professions is informing community care that is enhancing the independence and well-being of older people. With its proven responsiveness to social and policy priorities, environmental gerontology is now providing strong conceptual and empirical bases for advancing healthy aging and age-friendly societies.

Activities of Daily Living↗
PubMed2000

Cancer surveillance series: changing patterns of cutaneous malignant melanoma mortality rates among whites in the United States.

BACKGROUND: Mortality from melanoma among whites is still increasing in the United States. In this study, we describe the changing patterns of melanoma mortality rates among whites by demographic factors and geography and further assess the relationship between the geographic patterns and the UV radiation (UV-B) level. METHODS: Age-adjusted incidence and mortality rates were computed by use of the 1970 U.S. population standard. Annual percent changes of mortality were estimated by fitting regression lines to the logarithm of rates. The relationships between melanoma mortality rates and UV-B level over time were assessed by weighted regressions. All statistical tests were two-sided. RESULTS: From 1950-1954 through 1990-1994, melanoma mortality rates increased by 191% and 84% among males and females, respectively. Mortality rates peaked in the 1930 through 1950 birth cohorts for females and in the 1935 through 1950 birth cohorts for males. In the 1950 through 1969 study period, melanoma mortality rates showed a strong North-South gradient, but the gradient weakened in recent periods. The absolute change in mortality for a 10% increase in UV-B among females decreased from 0.08 additional deaths per 100 000 person-years in 1950-1959 to 0.01 additional deaths in 1990-1995. In contrast, the absolute change in mortality among males showed little change over time; additional deaths increased from 0.11 to 0.12 per 100 000 person-years. CONCLUSIONS: Melanoma mortality in the United States reflects the complex interplay of UV radiation levels in each geographic region, the sun-protection behaviors of each generation of males and females in childhood and adulthood, the geographic mobility of the population, and the risk awareness and early detection.

Adult↗
PubMed1977

Variola minor in Braganca Paulista county, 1956: a trend-surface analysis.

Trend-surface analysis (TSA), a form of polynomial regression used in geology, ecology and geography, was applied to analysis of the spread of an epidemic of variola minor in a small Brazilian city. Cubic surfaces gave a generalized map of the space-time distribution of the epidemic, allowing those parts of the city to be identified where variola minor was spreading rapidly or slowly. The epidemic spread relatively quickly over the core area of the city, especially to the peripherally located household dwellings in a northeast to south-west direction. The dwellings of adults and pre-school children introducing the disease into their households broadly followed the overall pattern. School child introductory cases from a southern-located school yielded a saddle-shaped contour pattern, centered about the school; but this pattern was not repeated for the school serving the northern half of the city, which showed a ridge-shaped pattern dipping toward the west. Cubic surfaces for the influence of certain household and individual characteristics were investigated, but showed only week trends. The nearest match to the bowl-shaped overall pattern of introductory dates was provided by the vaccination level of the households. From this application, it appears that TSA permits the identification of regional trends in an objective manner and gives a quantitative measure of the importance of these regional trends in terms of the overall variation in the spatial pattern.

Adult↗
PubMed1998

Urban-rural variations in suicides and undetermined deaths in England and Wales.

BACKGROUND: Given that a high proportion of undetermined deaths are thought to be suicides, the objective of the study was to compare the geography of the two verdicts, with emphasis on urban-rural differences, to determine whether the likelihood of a death being classified as suicide varies according to location. METHODS: Standardized mortality ratios (SMRs) were mapped for the local authority districts of England and Wales, using data aggregated over the period 1989-1992. Districts were classified according to population density, and SMRs calculated for each quartile. Finally, regression equations were obtained to model the relationship of suicide and undetermined death with a series of risk factors. RESULTS: Both male and female undetermined deaths showed a significant deficit in the most sparsely populated districts and a significant excess in the most densely populated districts. Female suicides were also significantly high in densely populated districts, but male suicides were highest in the most rural areas (SMR 110, 95 per cent confidence intervals 105-115). District variations in both verdicts were associated with the proportion of single-person households for both sexes, but male suicides and male undetermined deaths were associated with additional predictors, consistent with their distinct geographical distributions. CONCLUSIONS: Differences in suicide methods, the likelihood of communicating suicidal intent and, perhaps, variations in access to psychiatric services might be contributory factors to the observed differences between the verdicts. The results suggest that recorded suicides are a biased subset of actual suicides, particularly for males, and that the study of suicide verdicts alone is potentially misleading.

England↗
PubMedDate not supplied

Monitoring socioeconomic inequalities in sexually transmitted infections, tuberculosis, and violence: geocoding and choice of area-based socioeconomic measures--the public health disparities geocoding project (US).

OBJECTIVES: To determine which area-based socioeconomic measures, at which level of geography, are suitable for monitoring socioeconomic inequalities in sexually transmitted infections (STIs), tuberculosis (TB), and violence in the United States. METHODS: Cross-sectional analysis of public health surveillance data, geocoded and linked to area-based socioeconomic measures generated from 1990 census tract, block group, and ZIP Code data. We included all incident cases among residents of either Massachusetts (MA; 1990 population = 6016425) or Rhode Island (RI; 1990 population = 1003464) for: STIs (MA: 1994-1998, n = 26535 chlamydia, 7464 gonorrhea, 2619 syphilis; RI: 1994-1996, n = 4473 chlamydia, 1256 gonorrhea, 305 syphilis); TB (MA: 1993-1998, n = 1793; RI: 1985-1994, n = 576), and non-fatal weapons related injuries (MA: 1995-1997, n = 6628). RESULTS: Analyses indicated that: (a). block group and tract socioeconomic measures performed similarly within and across both states, with results more variable for the ZIP Code level measures; (b). measures of economic deprivation consistently detected the steepest socioeconomic gradients, considered across all outcomes (incidence rate ratios on the order of 10 or higher for syphilis, gonorrhea, and non-fatal intentional weapons-related injuries, and 7 or higher for chlamydia and TB); and (c). results were similar for categories generated by quintiles and by a priori categorical cut-points. CONCLUSIONS: Supplementing U.S. public health surveillance systems with census tract or block group area-based socioeconomic measures of economic deprivation could greatly enhance monitoring and analysis of social inequalities in health in the United States.

Adolescent↗
PubMed1996

Sunlight, cholesterol and coronary heart disease.

We investigated the relationship between geography and incidence of coronary heart disease, looking at deficiency of sunlight and thus of vitamin D as a factor that might influence susceptibility and thus disease incidence. Sunlight deficiency could increase blood cholesterol by allowing squalene metabolism to progress to cholesterol synthesis rather than to vitamin D synthesis as would occur with greater amounts of sunlight exposure, and the increased concentration of blood cholesterol during the winter months, confirmed in this study, may well be due to reduced sunlight exposure. We show evidence that outdoor activity (gardening) is associated with a lower concentration of blood cholesterol in the summer but not in the winter. We suggest that the geographical variation of coronary heart disease is not specific, but is seen in other diseases and sunlight influences susceptibility to a number of chronic diseases, of which coronary heart disease is one.

Cholesterol↗
PubMed1995

Test of the linear-no threshold theory of radiation carcinogenesis for inhaled radon decay products.

Data on lung cancer mortality rates vs. average radon concentration in homes for 1,601 U.S. counties are used to test the linear-no threshold theory. The widely recognized problems with ecological studies, as applied to this work, are addressed extensively. With or without corrections for variations in smoking prevalence, there is a strong tendency for lung cancer rates to decrease with increasing radon exposure, in sharp contrast to the increase expected from the theory. The discrepancy in slope is about 20 standard deviations. It is shown that uncertainties in lung cancer rates, radon exposures, and smoking prevalence are not important and that confounding by 54 socioeconomic factors, by geography, and by altitude and climate can explain only a small fraction of the discrepancy. Effects of known radon-smoking prevalence correlations--rural people have higher radon levels and smoke less than urban people, and smokers are exposed to less radon than non-smokers--are calculated and found to be trivial. In spite of extensive efforts, no potential explanation for the discrepancy other than failure of the linear-no threshold theory for carcinogenesis from inhaled radon decay products could be found.

Climate↗
PubMed2004

Genetic consequences of climatic oscillations in the Quaternary.

An appreciation of the scale and frequency of climatic oscillations in the past few million years is modifying our views on how evolution proceeds. Such major events caused extinction and repeated changes in the ranges of those taxa that survived. Their spatial effects depend on latitude and topography, with extensive extinction and recolonization in higher latitudes and altitudinal shifts and complex refugia nearer the tropics. The associated population dynamics varied with life history and geography, and the present genetic constitution of the populations and species carry attenuated signals of these past dynamics. Phylogeographic studies with DNA have burgeoned recently and studies are reviewed from the arctic, temperate and tropical regions, seeking commonalities of cause in the resulting genetic patterns. Arctic species show distinct shallow genetic clades with common geographical boundaries. Thus Beringia is distinct phylogeographically, but its role as a refugial source is complex. Arctic taxa do not show the common genetic pattern of southern richness and northern purity in north-temperate species. Temperate refugial regions in Europe and North America show relatively deep DNA divergence for many taxa, indicating their presence over several Ice Ages, and suggesting a mode of speciation by repeated allopatry. DNA evidence indicates temperate species in Europe had different patterns of postglacial colonization across the same area and different ones in previous oscillations, whereas the northwest region of North America was colonized from the north, east and south. Tropical montane regions contain deeply diverged lineages, often in a relatively small geographical area, suggesting their survival there from the Pliocene. Our poor understanding of refugial biodiversity would benefit from further combined fossil and genetic studies.

Animals↗
PubMedDate not supplied

CartoDraw: a fast algorithm for generating contiguous cartograms.

Cartograms are a well-known technique for showing geography-related statistical information, such as population demographics and epidemiological data. The basic idea is to distort a map by resizing its regions according to a statistical parameter, but in a way that keeps the map recognizable. In this study, we formally define a family of cartogram drawing problems. We show that even simple variants are unsolvable in the general case. Because the feasible variants are NP-complete, heuristics are needed to solve the problem. Previously proposed solutions suffer from problems with the quality of the generated drawings. For a cartogram to be recognizable, it is important to preserve the global shape or outline of the input map, a requirement that has been overlooked in the past. To address this, our objective function for cartogram drawing includes both global and local shape preservation. To measure the degree of shape preservation, we propose a shape similarity function, which is based on a Fourier transformation of the polygons' curvatures. Also, our application is visualization of dynamic data, for which we need an algorithm that recalculates a cartogram in a few seconds. None of the previous algorithms provides adequate performance with an acceptable level of quality for this application. In this paper, we therefore propose an efficient iterative scanline algorithm to reposition edges while preserving local and global shapes. Scanlines may be generated automatically or entered interactively to guide the optimization process more closely. We apply our algorithm to several example data sets and provide a detailed comparison of the two variants of our algorithm and previous approaches.

Algorithms↗
PubMed1987

Artefact explanations of inequalities in health: an assessment of the evidence.

Artefact explanations seek to account for inequalities in health as a construct of the measurement process. The Black Report believed that the artefact explanation was relatively unimportant in accounting for the persistence of class inequalities in health. This paper reviews the evidence on artefact explanations of class differentials in specific-cause and all-cause mortality data, and also of differentials by occupation, by geography, and by gender. It is concluded that the role of artefact explanations in mortality differentials is larger, more pervasive, and more complex than Black and his colleagues believed.

Female↗
PubMed1999

Future population distribution in the past and present.

"There is at present much public interest in the future geography of the Netherlands. Plans for new infrastructure to accommodate rail, road and air traffic are hotly debated. The location of new residential areas and the disposition of economic activity are also frequently discussed. Supply and demand of employment and housing show diverging trends in various parts of the country. For planners this raises the question as to the likely or advisable future population distribution."

Demography↗