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At least 307 records · Page 17Linked to original sources
PubMed2002

Cancer incidence and socioeconomic geography of Finland: a correlation study.

The influence that social determinants exert on cancer incidence and patterns is an expected aftermath of the predominantly environmental origin of cancer. This happens because social changes determine a wide range of individual behaviors, and hence of "proximate" causes of cancer. Whereas most of the previous social epidemiological studies focused on individual social classes and groups, in this paper we studied the influence of the social factors on cancer etiology at the larger scale of a whole country: Finland. The ecological analysis of cancer incidence and patterns in the Finnish regions pointed to both local and general correlations between tumors and socioeconomic descriptors. The most important correlations were: a) a general effect of economic and societal factors on cancer (namely, on the profiles of tumors in males and females, on the global cancer incidence in females, and on the difference in cancer incidence between the two sexes); b) a very specific pattern of correlations for the Ahvenanmaa islands; c) a clear geographic cline in tumor profile variability. The ecological epidemiology approach can provide important clues to public health policies.

Adolescent↗
PubMed2003

Predicting the geography of species' invasions via ecological niche modeling.

Species' invasions have long been regarded as enormously complex processes, so complex as to defy predictivity. Phases of this process, however, are emerging as highly predictable: the potential geographic course of an invasion can be anticipated with high precision based on the ecological niche characteristics of a species in its native geographic distributional area. This predictivity depends on the premise that ecological niches constitute long-term stable constraints on the potential geographic distributions of species, for which a sizeable body of evidence is accumulating. Hence, although the entire invasion process is indeed complex, the geographic course that invasions are able to take can be anticipated with considerable confidence.

Algorithms↗
PubMed2004

Geographies of hope: mining the frontiers of health in Denver and beyond, 1870-1965.

Across the western landscape of the United States, health was a natural resource, mined and sold by late-nineteenth and twentieth-century town boosters and physicians to those afflicted with chronic pulmonary illnesses such as tuberculosis and asthma. Regional economies of health were built upon climate and sunshine. After the Second World War, children, rather than nature, increasingly became a vital resource upon which institutions such as Denver's Jewish National Home for Asthmatic Children expanded the economic networks through which capital and drugs flowed. Despite these changes, the material traces of past landscapes lingered and resurfaced in the reconfigured places where hope dwelled.

Chronic Disease↗
PubMed2004

Harold Knapp and the geography of normal controversy: radioiodine in the historical environment.

In 1962, after high levels of the isotope Iodine-131 were detected in Utah milk supplies, Dr. Harold Knapp, a mathematician working for the AEC's Division of Biology and Medicine, developed a new model of estimating, first, the relation between a single deposition of radioactive fallout on pasturage and the levels of Iodine-131 in fresh milk and, second, the total dose to human thyroids, resulting from daily intake of the contaminated milk. The implications of Knapp's findings were enormous. They suggested that short-living radioiodine, rather than long-living nuclides such as radiostrontium, posed the greatest hazard from nuclear test fallout and that children raised in Nevada and Utah during the 1950s had been exposed to internal radiation doses far in excess of recommended guidelines. This paper explores the explicit historical revisionism of Knapp's study, his refusal, contra normal AEC practices of knowledge production and spatial representation, to distance himself from the people and places downwind from the Nevada Test Site, and the reactions his work provoked among his AEC colleagues.

Adolescent↗
PubMed2000

Geography of HFE C282Y and H63D mutations.

Hereditary hemochromatosis (HH) is a common autosomal recessive disorder causing inappropriate dietary iron absorption that affects North Europeans. HH is associated with the C282Y mutation of the HFE gene, and the H63D mutation to a lesser degree. Both mutations are abundant in Europe, with H63D also appearing in North Africa, the Middle East, and Asia. Emigration from Europe over the past 500 years has introduced C282Y and H63D to America, Australia, New Zealand, and South Africa in an essentially predictable fashion. The distinctive characteristics of the population genetics of HH are the confined racial distribution and high frequency in North European peoples. C282Y frequencies in North Europeans are typically between 5% and 10%, with homozygotes accounting for between 1/100 and 1/400 of these populations. The scarcity of the C282Y mutation in other populations accounts for the lack of HH in non-Europeans.

Emigration and Immigration↗
PubMed1994

Aedes albopictus (Diptera: Culicidae): a statistical model of the role of temperature, photoperiod, and geography in the induction of egg diapause.

Aedes albopictus (Skuse) lays eggs refractory to hatching in response to several environmental cues. The goal of this statistical treatment was to quantify the role and interaction of latitude and country of origin (Japan and the United States), photoperiod, rearing/holding temperature, and a newly identified element, elevation of the site of origin, with critical photoperiod (Cpp). We also describe the development of an equation relating the incidence of diapause to daylength, rearing/holding temperature, and latitude and elevation of the site of origin, an equation useful in the development of a simulation model of the population dynamics and distribution of Ae. albopictus in North America. The analysis indicated that elevation from 0 to 300 m is significantly correlated with Cpp. The results also corroborate earlier conclusions that, on the basis of a shallower geographical cline in photoperiodic response in the United States, North American strains of Ae. albopictus have a temperate origin in Asia and indicate that the rapid spread of this mosquito within the United States via the distribution of used tires resulted in founder populations that were only partially adapted in diapause response to local conditions.

Aedes↗
PubMed2006

The changing geography of Americans graduating from foreign medical schools.

PURPOSE: To study U.S.-born international medical graduates in order to analyze changes in their numbers and countries of training from the 1960s and before until the early 2000s. METHOD: This study was conducted from 2003-2004 at the Center for Health Workforce Studies, University of Washington. The analysis was based on data from March 2002 from the American Medical Association (AMA) for active physicians. AMA data were supplemented with data from several other sources. Descriptive statistics were produced on country of birth, country of medical school training, and year of training for all foreign-trained, patient-care physicians whose birth country was known. RESULTS: At least 17,000 of the foreign-trained physicians practicing in the United States are known to have been born in the United States. American physicians have graduated from foreign medical schools in increasing numbers since the 1960s. The number of U.S.-born physicians who graduated from a foreign medical school peaked in the early 1980s, but the phenomenon endures today. However, the countries in which these physicians chose to attend medical schools have changed significantly from the 1950s to the early 2000s. CONCLUSIONS: Over time, U.S.-born physicians have become much less likely to train in Europe and much more likely to train in certain Caribbean countries. U.S.-born physicians who graduate from medical schools abroad tend to train in just a handful of countries and attend a limited number of medical schools.

Cross-Sectional Studies↗
PubMed2005

'Airplanes are flying nursing homes': geographies in the concepts and locales of gerontological nursing practice.

With the geographical literatures and issues outlined in the first paper very much in mind, this paper focuses specifically on the places in the concepts and locales of gerontological nursing practice. Particular attention is paid to the role of nurses in the making of long-term care institutions and to some fundamental priorities of care. Consideration is also given to some broader impacts of neighbourhood and community as an important spatial context to nursing practice based both in institutions and the community. In the final section, the paper makes some observations on how place-sensitive practice and research might contribute to the uptake of evidence for practice. These discussions set the scene for the final paper in this special section focused on the future research agenda for place and older people nursing.

Aged↗
PubMed2005

The history and geography of diversification within the butterfly genus Lycaeides in North America.

The Lycaeides butterfly species complex in North America consists of two nominal, morphologically defined species. These butterflies are ecologically diverse and appear to be distributed as a geographically complex mosaic of locally differentiated populations that may be undergoing adaptive radiation. We asked whether patterns of molecular genetic variation within the species complex are congruent with currently recognized morphological species and whether the distribution of molecular variation is consistent with the hypothesis that Pleistocene climate changes contributed to the process of differentiation within the genus. Variation in the form of the genitalia from 726 males from 59 populations clearly distinguishes both species with only six populations containing morphologically intermediate or ambiguous individuals. However, partitioning of molecular variance in a 236 bp section of the mitochondrial AT-rich region from 628 individuals (57 populations) surveyed using single strand conformation polymorphism analysis (SSCP) indicates that only 26% of the total genetic variation is distributed along nominal species boundaries as defined by morphology. Instead, three phylogeographical groups were detected, represented by three major haplotype clades, which account for 90% of the total genetic variance. Pleistocene glaciations appear to have fostered divergence during glacial maxima, while post-glacial range expansions created opportunities for gene exchange and reticulation along suture zones between geographical groups. Data presented here allow us to make inferences about the history of the species complex. However, evidence of ancestral polymorphism and reticulation limit our ability to define species boundaries based on mitochondrial DNA sequence variation.

Analysis of Variance↗
PubMed2005

Diversity of algal endosymbionts (zooxanthellae) in octocorals: the roles of geography and host relationships.

The presence, genetic identity and diversity of algal endosymbionts (Symbiodinium) in 114 species from 69 genera (20 families) of octocorals from the Great Barrier Reef (GBR), the far eastern Pacific (EP) and the Caribbean was examined, and patterns of the octocoral-algal symbiosis were compared with patterns in the host phylogeny. Genetic analyses of the zooxanthellae were based on ribosomal DNA internal transcribed spacer 1 (ITS1) region. In the GBR samples, Symbiodinium clades A and G were encountered with A and G being rare. Clade B zooxanthellae have been previously reported from a GBR octocoral, but are also rare in octocorals from this region. Symbiodinium G has so far only been found in Foraminifera, but is rare in these organisms. In the Caribbean samples, only Symbiodinium clades B and C are present. Hence, Symbiodinium diversity at the level of phylogenetic clades is lower in octocorals from the Caribbean compared to those from the GBR. However, an unprecedented level of ITS1 diversity was observed within individual colonies of some Caribbean gorgonians, implying either that these simultaneously harbour multiple strains of clade B zooxanthellae, or that ITS1 heterogeneity exists within the genomes of some zooxanthellae. Intracladal diversity based on ITS should therefore be interpreted with caution, especially in cases where no independent evidence exists to support distinctiveness, such as ecological distribution or physiological characteristics. All samples from EP are azooxanthellate. Three unrelated GBR taxa that are described in the literature as azooxanthellate (Junceella fragilis, Euplexaura nuttingi and Stereonephthya sp. 1) contain clade G zooxanthellae, and their symbiotic association with zooxanthellae was confirmed by histology. These corals are pale in colour, whereas related azooxanthellate species are brightly coloured. The evolutionary loss or gain of zooxanthellae may have altered the light sensitivity of the host tissues, requiring the animals to adopt or reduce pigmentation. Finally, we superimposed patterns of the octocoral-algal symbiosis onto a molecular phylogeny of the host. The data show that many losses/gains of endosymbiosis have occurred during the evolution of octocorals. The ancestral state (azooxanthellate or zooxanthellate) in octocorals remains unclear, but the data suggest that on an evolutionary timescale octocorals can switch more easily between mixotrophy and heterotrophy compared to scleractinian corals, which coincides with a low reliance on photosynthetic carbon gain in the former group of organisms.

Animals↗
PubMed2006

Does geography explain ethnic inequalities in health in New Zealand?

OBJECTIVE: To quantify the potential contribution of inter-district relative to intradistrict variation to the Maori disparity in life expectancy in 2000-02, by counterfactual modelling. SETTING, DATA SOURCES AND METHODS: The setting was New Zealand's 21 health districts (District Health Boards, DHBs). All data (population estimates and life expectancy estimates) were sourced from Statistics New Zealand and relate to the 2000-02 period. Maori life expectancy (nationally) was recalculated under the counterfactual that Maori life expectancy in each DHB did not differ from total population life expectancy in the corresponding DHB (so eliminating intra-district variation). The difference between the observed total population and counterfactual Maori life expectancies therefore represents the contribution of inter-district variation to the Maori life expectancy disparity. RESULTS: Observed total population and Maori life expectancies at birth in 2000-02, pooling sexes, were 78.7 and 71.1 years respectively, giving a total disparity of 7.6 years. Under the counterfactual, Maori life expectancy increased to 78.4 years (and total population life expectancy to 79.0 years). Inter-district variation was therefore estimated to potentially contribute only 0.6 years or 8% to the total Maori disparity. Allowing for imprecision, inter-district variation almost certainly accounts for less than 10.5% of the total disparity. CONCLUSION: Inter-district or geographic variation makes only a small contribution to the total Maori disparity in life expectancy. Adjustment or standardisation for district is not necessary when comparing Maori and non-Maori health outcomes. If the policy goal is to reduce ethnic inequalities in health, then the focus of policy (e.g. funding formulae) needs to be on factors directly linked to ethnicity, rather than on geographic variations in health and health care that have an impact on all ethnic groups more-or-less alike.

Aged↗
PubMed2003

The changing epidemiology of GERD: geography and Helicobacter pylori.

BACKGROUND: Issues have arisen regarding H. pylori infection and GERD that have caused unnecessary confusion among practicing physicians. In the last century GERD became increasingly recognized in the West and it has become evident that the prevalence of GERD is now occurring in many previously underdeveloped countries. METHODS: This review article fosters understanding of the issues by focusing on the esophageal acid load and the factors that control it. In particular, we discuss the effects of the change in the patterns of gastritis that have occurred naturally as well as after H. pylori eradication and correlate those changes with their effects on the esophageal acid load. We show how it is possible to separate gastroesophageal reflux from gastroesophageal reflux disease based on differences in esophageal acid load. We also describe how the practice of assessing gastroesophageal reflux based on the time the intraesophageal pH is less than 4 resulted in investigators systematically discarding data critical to understanding of the effect of their interventions on esophageal acid load. Testable hypotheses are presented to explain the interactions between H. pylori and GERD and between H. pylori and the changing epidemiology of GERD. CONCLUSIONS: We propose that the confusion regarding H. pylori and the changing epidemiology of GERD is based on the failure to critically examine the historical evidence in relation to the other H. pylori-related diseases as well as reliance on techniques that are either unable to measure, or systematically discard data critical for understanding effects of various interventions on the esophageal acid load. This has resulted in propagation of erroneous concepts regarding H. pylori and adenocarcinoma of the esophagus and has resulted in some patients being denied appropriate therapy.

Acids↗