520,747 research outputs found

    Spatial and temporal variation in population trends in a long-distance migratory bird

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    Over the past three decades, evidence has been growing that many Afro-Palaearctic migratory bird populations have suffered sustained and severe declines. As causes of these declines exist across both the breeding and non-breeding season, identifying potential drivers of population change is complex. In order to explore the roles of changes in regional and local environmental conditions on population change, we examine spatial and temporal variation in population trajectories of one of Europe’s most abundant Afro-Palaearctic summer migrants, the willow warbler, Phylloscopus trochilus. Britain and Ireland. We use national survey data from Britain and Ireland (BBS: BTO/RSPB/JNCC Breeding Bird Survey and CBS: BWI/NPWS/Heritage Council Countryside Breeding Survey) from 1994 to 2006 to model the spatial and temporal variation in willow warbler population trends. Across Britain and Ireland, population trends follow a gradient from sharp declines in the south and east of England to shallow declines and/or slight increases in parts of north and west England, across Scotland and Ireland. Decreasing the spatial scale of analysis reveals variation in both the rate and spatial extent of population change within central England and the majority of Scotland. The rates of population change also vary temporally; declines in the south of England are shallower now than at the start of the time series, whereas populations further north in Britain have undergone periods of increase and decline. These patterns suggest that regional-scale drivers, such as changing climatic conditions, and local-scale processes, such as habitat change, are interacting to produce spatially variable population trends. We discuss the potential mechanisms underlying these interactions and the challenges in addressing such changes at scales relevant to migratory species

    Iron Age and Anglo-Saxon genomes from East England reveal British migration history

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    British population history has been shaped by a series of immigrations, including the early Anglo-Saxon migrations after 400 CE. It remains an open question how these events affected the genetic composition of the current British population. Here, we present whole-genome sequences from 10 individuals excavated close to Cambridge in the East of England, ranging from the late Iron Age to the middle Anglo-Saxon period. By analysing shared rare variants with hundreds of modern samples from Britain and Europe, we estimate that on average the contemporary East English population derives 38% of its ancestry from Anglo-Saxon migrations. We gain further insight with a new method, rarecoal, which infers population history and identifies fine-scale genetic ancestry from rare variants. Using rarecoal we find that the Anglo-Saxon samples are closely related to modern Dutch and Danish populations, while the Iron Age samples share ancestors with multiple Northern European populations including Britain

    How the Distribution of After-Tax Income Changed over the 1990s Business Cycle: A Comparison of the United States, Great Britain, Germany and Japan

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    Using kernel density estimation we find that over their 1990s business cycles the entire distribution of after-tax (disposable) income moved to the right in the United States and Great Britain while inequality declined. In contrast, Germany and Japan experienced less growth, a rise in inequality and a decline in the middle mass of their distributions that spread mostly to the right, much like the United States over its 1980s business cycle. Inequality fell within the older population in all four countries and within the younger population in the United States and Great Britain, but rose substantially in Germany and Japan.income inequality, kernel density estimation, economic well-being, cross-country comparisons

    Obesity, unhappiness, and the challenge of affluence : theory and evidence

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    Is affluence a good thing? The book "The Challenge of Affluence" by Avner Offer (2006) argues that economic prosperity weakens self-control and undermines human well-being. Consistent with a pessimistic view, we show that psychological distress has been rising through time in modern Great Britain. Taking over-eating as an example, our data reveal that half the British population view themselves as overweight, and that happiness and mental health are worse among fatter people in Britain and Germany. Comparisons also matter. We discuss problems of inference and argue that longitudinal data are needed. We suggest a theory of obesity imitation where utility depends on relative weight

    Making a national atlas of population by computer

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    This paper describes the conceptual and practical problems encountered and solved in producing a multi-colour atlas of population characteristics in Great Britain. The atlas itself is in A4 format; it consists of some thirty-four maps of Great Britain in four colours and the same number of regional maps, together with descriptive text. All maps were plotted on a laser plotter with a resolution of 127 microns. The paper describes how mapping of ratios, such as percentages, was found to be highly misleading and describes the novel probability mapping solution adopted, based on the signed chi-square statistic. In addition, the rationale for selecting the class intervals and for selecting colour schemes is described

    The impact of sarcoptic mange Sarcoptes scabiei on the British fox Vulpes vulpes population

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    1. Disease epizootics can significantly influence host population dynamics and the structure and functioning of ecological communities. Sarcoptic mange Sarcoptes scabiei has dramatically reduced red fox populations Vulpes vulpes in several countries, including Britain, although impacts on demographic processes are poorly understood. We review the literature on the impact of mange on red fox populations, assess its current distribution in Britain through a questionnaire survey and present new data on resultant demographic changes in foxes in Bristol, UK. 2. A mange epizootic in Sweden spread across the entire country in < 10 years resulting in a decline in fox density of up to 95%; density remained lowered for 15–20 years. In Spain, mange has been enzootic for > 75 years and is widely distributed; mange presence was negatively correlated with habitat quality. 3. Localized outbreaks have occurred sporadically in Britain during the last 100 years. The most recent large-scale outbreak arose in the 1990s, although mange has been present in south London and surrounding environs since the 1940s. The questionnaire survey indicated that mange was broadly distributed across Britain, but areas of perceived high prevalence (> 50% affected) were mainly in central and southern England. Habitat type did not significantly affect the presence/absence of mange or perceived prevalence rates. Subjective assessments suggested that populations take 15–20 years to recover. 4. Mange appeared in Bristol’s foxes in 1994. During the epizootic phase (1994–95), mange spread through the city at a rate of 0.6–0.9 km/month, with a rise in infection in domestic dogs Canis familiaris c. 1–2 months later. Juvenile and adult fox mortality increased and the proportion of females that reproduced declined but litter size was unaffected. Population density declined by > 95%. 5. In the enzootic phase (1996–present), mange was the most significant mortality factor. Juvenile mortality was significantly higher than in the pre-mange period, and the number of juveniles classified as dispersers declined. Mange infection reduced the reproductive potential of males and females: females with advanced mange did not breed; severely infected males failed to undergo spermatogenesis. In 2004, Bristol fox population density was only 15% of that in 1994

    Inequalities in premature mortality in Britain: observational study from 1921 to 2007

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    Objective To report on the extent of inequality in premature mortality as measured between geographical areas in Britain. Design Observational study of routinely collected mortality data and public records. Population subdivided by age, sex, and geographical area (parliamentary constituencies from 1991 to 2007, pre-1974 local authorities over a longer time span). Setting Great Britain. Participants Entire population aged under 75 from 1990 to 2007, and entire population aged under 65 in the periods 1921-39, 1950-3, 1959-63, 1969-73, and 1981-2007. Main outcome measure Relative index of inequality (RII) and ratios of inequality in age-sex standardised mortality ratios under ages 75 and 65. The relative index of inequality is the relative rate of mortality for the hypothetically worst-off compared with the hypothetically best-off person in the population, assuming a linear association between socioeconomic position and risk of mortality. The ratio of inequality is the ratio of the standardised mortality ratio of the most deprived 10% to the least deprived 10%. Results When measured by the relative index of inequality, geographical inequalities in age-sex standardised rates of mortality below age 75 have increased every two years from 1990-1 to 2006-7 without exception. Over this period the relative index of inequality increased from 1.61 (95% confidence interval 1.52 to 1.69) in 1990-1 to 2.14 (2.02 to 2.27) in 2006-7. Simple ratios indicated a brief period around 2001 when a small reduction in inequality was recorded, but this was quickly reversed and inequalities up to the age of 75 have now reached the highest levels reported since at least 1990. Similarly, inequalities in mortality ratios under the age of 65 improved slightly in the early years of this century but the latest figures surpass the most extreme previously reported. Comparison of crudely age-sex standardised rates for those below age 65 from historical records showed that geographical inequalities in mortality are higher in the most recent decade than in any similar time period for which records are available since at least 1921. Conclusions Inequalities in premature mortality between areas of Britain continued to rise steadily during the first decade of the 21st century. The last time in the long economic record that inequalities were almost as high was in the lead up to the economic crash of 1929 and the economic depression of the 1930s. The economic crash of 2008 might precede even greater inequalities in mortality between areas in Britain

    Public awareness of cancer in Britain: a population-based survey of adults

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    *_Objective:_* To assess public awareness of cancer warning signs, anticipated delay, and perceived barriers to seeking medical advice in the British population. &#xd;&#xa;Methods: We carried out a population-based survey using face-to-face, computer-assisted interviews to administer the Cancer Awareness Measure (CAM), a newly-developed, validated measure of cancer awareness. The sample included 2216 adults (970 male and 1246 female) recruited as part of the Office for National Statistics Opinions Survey using stratified probability sampling.&#xd;&#xa;&#xd;&#xa;*_Results:_* Awareness of cancer warning signs was low when open-ended (recall) questions were used and higher with closed (recognition) questions; but on either measure, awareness was lower in those who were male, younger, and from lower socioeconomic status (SES) groups or ethnic minorities. The most commonly endorsed barriers to help-seeking were difficulty making an appointment, worry about wasting the doctor&#x2019;s time and worry about what would be found. Emotional barriers were more prominent in lower SES groups and practical barriers (e.g. too busy) more prominent in higher SES groups. Anticipated delay was lower in ethnic minority and lower SES groups. In multivariate analysis, higher symptom awareness was associated with lower anticipated delay, and more barriers with greater anticipated delay.&#xd;&#xa;&#xd;&#xa;*_Conclusions:_* A combination of public education about symptoms and empowerment to seek medical advice, as well as support at primary care level, could enhance early presentation and improve cancer outcomes

    Retirement: Institutional Pathways and Individual Trajectories in Britain and Germany

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    Since the 1970s people have retired increasingly early across advanced societies. Parallel to this trend, numerous institutional early retirement pathways evolved, such as bridge unemployment and pre-retirement schemes. This article compares retirement in Britain and Germany to show how individuals progress through these institutional retirement pathways. The analysis uses longitudinal data and recent innovations in sequence analysis to capture the sequential nature of retirement as a series of transitions over time. As expected, prominent institutional retirement pathways are mirrored in individual retirement trajectories. Beyond these expected patterns, there are pronounced regularities in individual retirement trajectories outside of explicit institutional pathways. The \'institution of the family\' is an additional powerful force in structuring women\'s retirement. Access to advantageous institutional retirement pathways is stratified by gender, education, income, and health. The article concludes that specific population groups, particularly women, are systematically excluded from protective institutional early retirement pathways in Britain and Germany.Retirement, Aging, Life Course, Sequence Analysis, Germany, Britain, Gender
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