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At least 973 records · Page 54Linked to original sources
PubMed1978

Headspace volatiles of marihuana and hashish: gas chromatographic analysis of samples of different geographic origin.

The sweet odor of marihuana is of interest for instrumental monitoring of illicit drug traffic and for applications in forensic work. Headspace volatiles of marihuana and hashish of different origin are examined by gas chromatography, and relative compositions of 24 samples are compared. No correlation between volatile make up and geography was found, but the profiling procedures are shown to be of use in the forensic problem of relating samples to a common source.

Cannabis↗
PubMed2001

Georeferenced aquatic fate simulation of cleaning agent and detergent ingredients in the river Rur catchment (Germany).

The Geography-referenced regional exposure assessment tool for European rivers (GREAT-ER) 1.0 was developed in the context of environmental risk assessment of chemicals to calculate the aquatic fate of 'down-the-drain' chemicals in surface waters due to point release. As a follow-up project, the river Rur catchment in Germany was incorporated into the system. This included aspects of data collection, modelling and monitoring. Investigated substances are the four detergent and cleaning agent ingredients boron, linear alkylbenzene sulfonate (LAS), nitrilotriacetate (NTA) and ethylenediaminetetraacetate (EDTA). Results of the catchment's incorporation into the system and a comparison of GREAT-ER simulations with different monitoring results are both given. It is shown that data sets derived from a literature review can be used to calculate concentration profiles that are in the range of measured values. Since the model establishes a causal relationship between emission sites and data on the one hand, and observed concentrations in the receiving surface waters on the other, the simulation results can be used to explain monitoring data.

Detergents↗
PubMed2002

Anthropogenic and natural CO2 emission sources in an arid urban environment.

Recent research has shown the Phoenix, AZ metropolitan region to be characterized by a CO2 dome that peaks near the urban center. The CO2 levels, 50% greater than the surrounding non-urban areas, have been attributed to anthropogenic sources and the physical geography of the area. We quantified sources of CO2 emissions across the metropolitan region. Anthropogenic CO2 emission data were obtained from a variety of government and NGO sources. Soil CO2 efflux from the dominant land-use types was measured over the year. Humans and automobile activity produced more than 80% input of CO2 into the urban environment. Soil CO2 efflux from the natural desert ecosystems showed minimal emissions during hot and dry periods, but responded rapidly to moisture. Conversely, human maintained vegetation types (e.g. golf courses, lawns, irrigated agriculture) have greater efflux and are both temperature and soil moisture dependent. Landfills exhibited the most consistent rates, but were temperature and moisture independent. We estimate the annual CO2 released from the predominant land-use types in the Phoenix region and present a graphical portrayal of soil CO2 emissions and the total natural and anthropogenic CO2 emissions in the metropolitan region using a GIS-based approach. The results presented here do not mimic the spatial pattern shown in previous studies. Only, with sophisticated mixing models will we be able to address the total effect of urbanization on CO2 levels and the contribution to regional patterns.

Agriculture↗
PubMed1998

Intellectual intersections: gender and health in the Pacific.

Intriguing intellectual intersections offer the promise of enriching medical geography and making it both more theoretically sophisticated and more policy relevant. Employing a socio-ecological model of health, this paper explores several of these intersections, including the incorporation of gender into our research frameworks. As a context, the complex reasons for the increased interest in women's health over the past two decades, including the persistent tensions surrounding this interest, are reviewed. Drawing not only from conventional sources but also from literature on gender relations, domestic violence and aging in the Pacific as well as recent reports on health and socioeconomic development, key issues for women's health in the Pacific Islands are addressed.

Aging↗
PubMed1998

Over the hill and far away: distance as a barrier to the provision of assistance to elderly relatives.

This paper considers the impact of the distance between employed caregivers and their elderly relatives on the provision of various forms of family-based assistance ("eldercare"), and in so doing it contributes to two overlapping literatures, one on the geography of care for elderly persons and the other on eldercare as a "work and family" issue. The paper also seeks to interpret and understand the spatiality of eldercare in light of evolving public policy on the care of dependent populations, and does so with an eye to the highly gendered nature of family caregiving. The empirical portion of the paper draws on a national survey of work and family conducted by CARNET (The Canadian Aging Research Network). Analysis of data for 1149 respondents with eldercare responsibilities reveals significant distance-decay effects in the average (weekly) number of hours devoted to eldercare. However, disaggregation by gender reveals that only male caregivers display this normative behaviour. Analysis of the average time-distances at which particular types of assistance are provided reveals a similar "gender gap"--women are willing to travel farther, more often, than male caregivers. The results suggest that the reconceptualization of aging as a "private" problem, to be attended to (by women) in the family and community, will particularly affect the careers and family lives of female caregivers, for they are more likely than their male counterparts to take on more travel and try to squeeze more into already tight time budgets.

Activities of Daily Living↗
PubMed2002

Ultraviolet radiation and autoimmune disease: insights from epidemiological research.

This review examines the epidemiological evidence that suggests ultraviolet radiation (UVR) may play a protective role in three autoimmune diseases: multiple sclerosis, insulin-dependent diabetes mellitus and rheumatoid arthritis. To date, most of the information has accumulated from population studies that have studied the relationship between geography or climate and autoimmune disease prevalence. An interesting gradient of increasing prevalence with increasing latitude has been observed for at least two of the three diseases. This is most evident for multiple sclerosis, but a similar gradient has been shown for insulin-dependent diabetes mellitus in Europe and North America. Seasonal influences on both disease incidence and clinical course and, more recently, analytical studies at the individual level have provided further support for a possible protective role for UVR in some of these diseases but the data are not conclusive. Organ-specific autoimmune diseases involve Th1 cell-mediated immune processes. Recent work in photoimmunology has shown ultraviolet B (UVB) can specifically attenuate these processes through several mechanisms which we discuss. In particular, the possible contribution of an UVR-induced increase in serum vitamin D (1,25(OH)2D3) levels in the beneficial immunomodulation of these diseases is discussed.

Animals↗
PubMed2003

Extensive mtDNA variation within the yellow-pine chipmunk, Tamias amoenus (Rodentia: Sciuridae), and phylogeographic inferences for northwest North America.

The yellow-pine chipmunk, Tamias amoenus, is common in xerophytic forests throughout much of northwest North America. We analyzed cytochrome b sequence variation from 155 individuals representing 57 localities across the distribution of T. amoenus including 10 additional species of Tamias. Maximum likelihood and parsimony tree estimation methods were used in conjunction with nested clade analysis to infer both deep and population-level processes. Our results indicate that two currently recognized subspecies of T. amoenus (T. a. canicaudus and T. a. cratericus) are not nested within other samples of T. amoenus. Maximum uncorrected levels of intraspecific sequence divergence within remaining samples of T. amoenus are >7%. Substantial geographic variation is characterized by 12 well-supported clades that correspond to distinct mountain ranges, but do not necessarily follow existing subspecific taxonomy. Significant association between geography and genealogy was detected within many of these clades and can be attributed to different population-level processes including past fragmentation, recent range expansion, and isolation by distance.

Animals↗
PubMed2002

Liminality and breastfeeding: women negotiating space and two bodies.

It is almost universally accepted that breastfeeding infants is nutritionally superior to bottle-feeding. However, despite this medical advice, in many countries breastfeeding rates remain low and in the UK, rates are relatively static. The literature on breastfeeding has discussed international rates and the broad socio-economic factors influencing these rates. Through an observational study of a group of breastfeeding and non-breastfeeding women in the United Kingdom, this research utilises contemporary theoretical perspectives on the body, space and rites of passage, and investigates the reasons why some breastfeeding mothers may be in a liminal period, and the breastfeeding event itself, at times, a liminal and marginalised act. The paper argues that, for the group studied, breastfeeding is sometimes discouraged by its medicalisation, and that breastmilk and breastfeeding are often considered by mothers to be embarrassing. Many of the women studied regarded certain public and private places to be unacceptable places to breastfeed and claimed to modify their behaviour accordingly. The paper demonstrates the value of conducting locally based qualitative research into breastfeeding experiences, and of using theoretical perspectives from post-medical geography to interpret women's experiences.

Attitude to Health↗
PubMed2002

Population production and modelling mortality--an application of geographic information systems in health inequalities research.

Much research into spatial inequalities in health has sought the balance between compositional and contextual influences on observed patterns. Research published recently by the authors sought to determine whether composition of areas alone might account for the changing geography of mortality in Britain, between 1983 and 1993. The research required data describing Britain in terms of the numbers and location of people with every possible combination of age group, sex, social class and employment status. This paper describes the approach and the custom written geographic information system which estimated these data, and their subsequent application.

Female↗
PubMed2002

Using Internet GIS technology for sharing health and health related data for the West Midlands Region.

Recent government legislation highlights the need for co-operative working by government agencies to improve the overall health of people and to help reduce the existing health inequalities in England. To effectively tackle health inequalities, access to a range of timely and relevant data sets about a region is vital. The Multi-Agency Internet Geographic Information Service (MAIGIS) project is a 3-yr pilot project funded by the Public Health Development Fund to establish an interactive map-based web site for sharing health and health related data for the West Midlands Region (http://maigis.wmpho.org.uk). Data sets within the MAIGIS project follow three broad themes of health, socio-economic and environmental information. Data are made available by different organisations and shared using geography as the linking theme. This paper discusses the use of Internet GIS technology for sharing health and health related data based on the issues that arose during the formative period of the MAIGIS project. Issues such as data confidentiality, amalgamation and copyright are discussed and the technical development of the project is outlined. The links that MAIGIS has formed with other regional and national initiatives for the sharing of health and health related information are also presented. Finally, the future work programme for the MAIGIS project is summarised.

Data Collection↗
PubMed2003

Predicting smoking behaviour in census output areas across Scotland.

Spatially disaggregated surveys of smoking behaviour are rare and hence estimating the geography of the incidence of smoking is difficult. The main aim of this study is to develop a technique for estimating smoking probability for different age/sex groups in small areas across the whole of Scotland using information on smoking behaviour from the Scottish Household Survey. This is useful not only in its own right, but as an aid to studies of geographical variations in diseases such as lung cancer that, as a first step, need to control for smoking behaviour. The method developed uses individual-level characteristics from the Scottish Household Survey combined with a set of output area and pseudo-postcode sector measures from the 1991 census to model the probability of smoking. The parameters from this model are then used to make smoking predictions by age and sex for output areas across Scotland. This is the first time that such geographically detailed estimates of smoking have been made available.

Adolescent↗
PubMed2006

Seroprevalence of IgG antibodies to SARS-coronavirus in asymptomatic or subclinical population groups.

We systematically reviewed the current understanding of human population immunity against SARS-CoV in different groups, settings and geography. Our meta-analysis, which included all identified studies except those on wild animal handlers, yielded an overall seroprevalence of 0.10% [95% confidence interval (CI) 0.02-0.18]. Health-care workers and others who had close contact with SARS patients had a slightly higher degree of seroconversion (0.23%, 95% CI 0.02-0.45) compared to healthy blood donors, others from the general community or non-SARS patients recruited from the health-care setting (0.16%, 95% CI 0-0.37). When analysed by the two broad classes of testing procedures, it is clear that serial confirmatory test protocols resulted in a much lower estimate (0.050%, 95% CI 0-0.15) than single test protocols (0.20%, 95% CI 0.06-0.34). Potential epidemiological and laboratory pitfalls are also discussed as they may give rise to false or inconsistent results in measuring the seroprevalence of IgG antibodies to SARS-CoV.

Antibody Formation↗
PubMed2004

Geographic information systems in public health and medicine.

Geographic information systems (GIS) are increasingly being used in public health and medicine. Advances in computer technology, the encouragement of its use by the federal government, and the wide availability of academic and commercial courses on GIS are responsible for its growth. Some view GIS as only a tool for spatial research and policy analysis, while others believe it is part of a larger emerging new science including geography, cartography, geodesy, and remote sensing. The specific advantages and problems of GIS are discussed. The greatest potential of GIS is its ability to clearly show the results of complex analyses through maps. Problems in using GIS include its costs, the need to adequately train staff, the use of appropriate spatial units, and the risk it poses to violating patient confidentiality. Lastly, the fourteen articles in this special issue devoted to GIS are introduced and briefly discussed.

Data Interpretation, Statistical↗
PubMed2000

Updating geographical knowledge: principles of coherence and inertia.

In 2 experiments, the authors investigated how representations of global geography are updated when people learn new location information about individual cities. Participants estimated the latitude of cities in North America (Experiment 1) and in the Old and New Worlds (Experiment 2). After making their first estimates, participants were given information about the latitudes of 2 cities and asked to make a second set of estimates. Both the first and second estimates revealed evidence for psychologically distinct geographical subregions that were coordinated, in an ordinal sense, across the Atlantic Ocean. Further, the second estimates were affected by the nature of the physical adjacency between regions (e.g., the southern U.S. and Mexico) and by accurate location information about distant, but coordinated, subregions (e.g., the southern U.S. and Mediterranean Europe). The data provide support for a framework for making geographical estimates in which people strike a balance between 2 principles: the need to keep their knowledge base coherent, and the inertial tendency to resist changing the knowledge base unless it is necessary to maintain coherence.

Cognition↗
PubMed2006

Global-scale location and distance estimates: common representations and strategies in absolute and relative judgments.

The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latitude estimates revealed the presence of psychologically based regions with large gaps between them and a tendency to stretch North America southward toward the equator. The distance estimates revealed the same properties in the representation recovered via multidimensional scaling. Though the aggregated within- and between-regions distance estimates were fitted by Stevens's law (S. S. Stevens, 1957), this was an averaging artifact: The appropriateness of a power function to describe distance estimates depended on the regional membership of the cities. The authors conclude that plausible reasoning strategies, combined with regionalized representations and beliefs about the location of these relative to global landmarks, underlie global-scale latitude and distance judgments.

Cognition↗
PubMed2004

Implications of biogeography of human populations for 'race' and medicine.

In this review, we focus on the biogeographical distribution of genetic variation and address whether or not populations cluster according to the popular concept of 'race'. We show that racial classifications are inadequate descriptors of the distribution of genetic variation in our species. Although populations do cluster by broad geographic regions, which generally correspond to socially recognized races, the distribution of genetic variation is quasicontinuous in clinal patterns related to geography. The broad global pattern reflects the accumulation of genetic drift associated with a recent African origin of modern humans, followed by expansion out of Africa and across the rest of the globe. Because disease genes may be geographically restricted due to mutation, genetic drift, migration and natural selection, knowledge of individual ancestry will be important for biomedical studies. Identifiers based on race will often be insufficient.

Biological Evolution↗
PubMed2006

Can landscape ecology untangle the complexity of antibiotic resistance?

Bacterial resistance to antibiotics continues to pose a serious threat to human and animal health. Given the considerable spatial and temporal heterogeneity in the distribution of resistance and the factors that affect its evolution, dissemination and persistence, we argue that antibiotic resistance must be viewed as an ecological problem. A fundamental difficulty in assessing the causal relationship between antibiotic use and resistance is the confounding influence of geography: the co-localization of resistant bacterial species with antibiotic use does not necessarily imply causation and could represent the presence of environmental conditions and factors that have independently contributed to the occurrence of resistance. Here, we show how landscape ecology, which links the biotic and abiotic factors of an ecosystem, might help to untangle the complexity of antibiotic resistance and improve the interpretation of ecological studies.

Animals↗
PubMed2004

Human X-chromosomal lineages in Europe reveal Middle Eastern and Asiatic contacts.

Within Europe, classical genetic markers, nuclear autosomal and Y-chromosome DNA polymorphisms display an east-west frequency gradient. This has been taken as evidence for the westward migration of Neolithic farmers from the Middle East. In contrast, most studies of mtDNA variation in Europe and the Middle East have not revealed clinal distributions. Here we report an analysis of dys44 haplotypes, consisting of 35 polymorphisms on an 8 kb segment of the dystrophin gene on Xp21, in a sample of 1203 Eurasian chromosomes. Our results do not show a significant genetic structure in Europe, though when Middle Eastern samples are included a very low but significant genetic structure, rooted in Middle Eastern heterogeneity, is observed. This structure was not correlated to either geography or language, indicating that neither of these factors are a barrier to gene flow within Europe and/or the Middle East. Spatial autocorrelation analysis did not show clinal variation from the Middle East to Europe, though an underlying and ancient east-west cline across the Eurasian continent was detected. Clines provide a strong signal of ancient major population migration(s), and we suggest that the observed cline likely resulted from an ancient, bifurcating migration out of Africa that influenced the colonizing of Europe, Asia and the Americas. Our study reveals that, in addition to settlements from the Near East, Europe has been influenced by other major population movements, such as expansion(s) from Asia, as well as by recent gene flow from within Europe and the Middle East.

Asia↗