119 research outputs found

    Small business survey: linking 2006 and 2007 waves to the IDBR

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    This report describes work to link two waves of the Small Business Survey (SBS) to the Inter-Departmental Business Register (IDBR)1. The first is the Annual Small Business Survey 2006/07, hereafter SBS 2006; the second is the survey for 2007/8, hereafter SBS 2007. The linking work has been undertaken by Belmana and Middlesex University; IFF Research conducted both surveys and has overseen this work. The focus of this research was to understand the strengths and weaknesses of different methods of linking and then develop an approach for application to the 2006 and 2007 waves of the survey. A particular difficulty, as older waves of SBS are linked to the IDBR, is the changes to businesses that would have occurred since the survey. This work has taken steps to reduce the effect of the age of the survey on the quality of the data linking, by linking to historic vintages of the IDBR and the Companies House register. The report also reviews earlier work by the Office for National Statistics (ONS) linking the 2010 and 2012 SBS surveys to the IDBR. The project draws on insights from this, but introduces new linking methods that improve link rates. Various quality checks have been undertaken and, given the surveys were conducted almost a decade ago, the ability to link a higher proportion of respondents to the IDBR than achieved for the 2010 survey indicates the linking of SBS can be undertaken even for relatively old waves. Some preliminary analysis of the linked survey data suggests that there is potential for understanding the more long-term outcomes for businesses and correlating these with SBS responses

    Correlates of record linkage and estimating risks of non-linkage biases in business data sets

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    Researchers often utilize data sets that link information from multiple sources, but non‐linkage biases caused by linked and non‐linked subject differences are little understood, especially in business data sets. We address these knowledge gaps by studying biases in linkable 2010 UK Small Business Survey data sets. We identify correlates of business linkage propensity, and also for the first time its components: consent to linkage and register identifier appendability. As well, we take a novel approach to evaluating non‐linkage bias risks, by computing data set representativeness indicators (comparable, decomposable sample subset similarity measures). We find that the main impacts on linkage propensities and bias risks are due to consenter–non‐consenter differences explicable given business survey response processes, and differences between subjects with and without identifiers caused by register undercoverage of very small businesses. We then discuss consequences for the analysis of linked business data sets, and implications of the evaluation methods we introduce for linked data set producers and users

    Demographic reconstruction from ancient DNA supports rapid extinction of the great auk

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    The great auk was once abundant and distributed across the North Atlantic. It is now extinct, having been heavily exploited for its eggs, meat, and feathers. We investigated the impact of human hunting on its demise by integrating genetic data, GPS-based ocean current data, and analyses of population viability. We sequenced complete mitochondrial genomes of 41 individuals from across the species’ geographic range and reconstructed population structure and population dynamics throughout the Holocene. Taken together, our data do not provide any evidence that great auks were at risk of extinction prior to the onset of intensive human hunting in the early 16th century. In addition, our population viability analyses reveal that even if the great auk had not been under threat by environmental change, human hunting alone could have been sufficient to cause its extinction. Our results emphasise the vulnerability of even abundant and widespread species to intense and localised exploitation

    Genetic differentiation of European grayling (Thymallus thymallus) populations in Serbia, based on mitochondrial and nuclear DNA analyses

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    <p>Abstract</p> <p>Background</p> <p>The structure and diversity of grayling (<it>Thymallus thymallus</it>) populations have been well studied in most of its native habitat; however the southernmost populations of the Balkan Peninsula remain largely unexplored. The purpose of this study was to assess the genetic diversity of Serbian grayling populations, detect the impact of stocking and provide guidelines for conservation and management.</p> <p>Methods</p> <p>Eighty grayling individuals were collected from four rivers (Ibar, Lim, Drina and Rzav). The mitochondrial DNA control region (CR; 595 bp of the 3'end and 74 bp of flanking tRNA) and the ATP6 gene (630 bp fragment) were sequenced for 20 individuals (five from each locality). In addition, all individuals were genotyped with 12 microsatellite loci. The diversity and structure of the populations as well as the recent and ancient population declines were studied using specialized software.</p> <p>Results</p> <p>We detected three new haplotypes in the mtDNA CR and four haplotypes in the ATP6 gene of which three had not been described before. Previously, one CR haplotype and two ATP6 gene haplotypes had been identified as allochthonous, originating from Slovenia. Reconstruction of phylogenetic relations placed the remaining two CR haplotypes from the River Danube drainage of Serbia into a new clade, which is related to the previously described sister Slovenian clade. These two clades form a new Balkan clade. Microsatellite marker analysis showed that all four populations are genetically distinct from each other without any sign of intra-population structure, although stocking of the most diverse population (Drina River) was confirmed by mtDNA analysis. Recent and historical population declines of Serbian grayling do not differ from those of other European populations.</p> <p>Conclusions</p> <p>Our study shows that (1) the Ibar, Lim and Drina Rivers grayling populations are genetically distinct from populations outside of Serbia and thus should be managed as native populations in spite of some introgression in the Drina River population and (2) the Rzav River population is not appropriate for further stocking activities since it originates from stocked Slovenian grayling. However, the Rzav River population does not represent an immediate danger to other populations because it is physically isolated from these.</p

    Mucopolysaccharidosis type II (Hunter syndrome): a clinical review and recommendations for treatment in the era of enzyme replacement therapy

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    Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is a rare X-linked recessive disease caused by deficiency of the lysosomal enzyme iduronate-2-sulphatase, leading to progressive accumulation of glycosaminoglycans in nearly all cell types, tissues and organs. Clinical manifestations include severe airway obstruction, skeletal deformities, cardiomyopathy and, in most patients, neurological decline. Death usually occurs in the second decade of life, although some patients with less severe disease have survived into their fifth or sixth decade. Until recently, there has been no effective therapy for MPS II, and care has been palliative. Enzyme replacement therapy (ERT) with recombinant human iduronate-2-sulphatase (idursulfase), however, has now been introduced. Weekly intravenous infusions of idursulfase have been shown to improve many of the signs and symptoms and overall wellbeing in patients with MPS II. This paper provides an overview of the clinical manifestations, diagnosis and symptomatic management of patients with MPS II and provides recommendations for the use of ERT. The issue of treating very young patients and those with CNS involvement is also discussed. ERT with idursulfase has the potential to benefit many patients with MPS II, especially if started early in the course of the disease

    Pushing the limits: palynological investigations at the margin of the Greenland Ice Sheet in the Norse Western Settlement

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    This paper presents two high-resolution pollen records dating to ~AD 1000-1400 that reveal the impacts of Norse colonists on vegetation and landscape around a remote farmstead in the Western Settlement of Greenland. The study is centred upon a ‘centralised farm’ (ruin group V53d) in Austmannadalen, near the margin of the Greenland Ice Sheet (64º13’ N, 49º49’W). The climate is low arctic and considered marginal in terms of its suitability for the type of pastoral agriculture that the Norse settlers introduced. The data reveal that at a short distance (~500 m) from the farm buildings, the palynological ‘footprint’ for settlement becomes extremely indistinct, the only clear palaeoenvironmental evidence for a human presence being elevated levels of microscopic charcoal. This contrasts with the Eastern Settlement, where a strong palynological signature for Norse landnám is evident, from the local (individual farm) through to the regional (landscape) scale. The palynological data from Austmannadalen, and the Western Settlement more generally, imply that farming occurred at very low intensity. This aligns with ideas that promote the importance of hunting, and trade in valuable Arctic commodities (e.g. walrus ivory), ahead of a search for new pasture as the dominant motivation driving the Norse settlement of this region

    100 ancient genomes show repeated population turnovers in Neolithic Denmark.

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    Major migration events in Holocene Eurasia have been characterized genetically at broad regional scales &lt;sup&gt;1-4&lt;/sup&gt; . However, insights into the population dynamics in the contact zones are hampered by a lack of ancient genomic data sampled at high spatiotemporal resolution &lt;sup&gt;5-7&lt;/sup&gt; . Here, to address this, we analysed shotgun-sequenced genomes from 100 skeletons spanning 7,300 years of the Mesolithic period, Neolithic period and Early Bronze Age in Denmark and integrated these with proxies for diet ( &lt;sup&gt;13&lt;/sup&gt; C and &lt;sup&gt;15&lt;/sup&gt; N content), mobility ( &lt;sup&gt;87&lt;/sup&gt; Sr/ &lt;sup&gt;86&lt;/sup&gt; Sr ratio) and vegetation cover (pollen). We observe that Danish Mesolithic individuals of the Maglemose, Kongemose and Ertebølle cultures form a distinct genetic cluster related to other Western European hunter-gatherers. Despite shifts in material culture they displayed genetic homogeneity from around 10,500 to 5,900 calibrated years before present, when Neolithic farmers with Anatolian-derived ancestry arrived. Although the Neolithic transition was delayed by more than a millennium relative to Central Europe, it was very abrupt and resulted in a population turnover with limited genetic contribution from local hunter-gatherers. The succeeding Neolithic population, associated with the Funnel Beaker culture, persisted for only about 1,000 years before immigrants with eastern Steppe-derived ancestry arrived. This second and equally rapid population replacement gave rise to the Single Grave culture with an ancestry profile more similar to present-day Danes. In our multiproxy dataset, these major demographic events are manifested as parallel shifts in genotype, phenotype, diet and land use

    The population history of northeastern Siberia since the Pleistocene.

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    Northeastern Siberia has been inhabited by humans for more than 40,000 years but its deep population history remains poorly understood. Here we investigate the late Pleistocene population history of northeastern Siberia through analyses of 34 newly recovered ancient genomes that date to between 31,000 and 600 years ago. We document complex population dynamics during this period, including at least three major migration events: an initial peopling by a previously unknown Palaeolithic population of 'Ancient North Siberians' who are distantly related to early West Eurasian hunter-gatherers; the arrival of East Asian-related peoples, which gave rise to 'Ancient Palaeo-Siberians' who are closely related to contemporary communities from far-northeastern Siberia (such as the Koryaks), as well as Native Americans; and a Holocene migration of other East Asian-related peoples, who we name 'Neo-Siberians', and from whom many contemporary Siberians are descended. Each of these population expansions largely replaced the earlier inhabitants, and ultimately generated the mosaic genetic make-up of contemporary peoples who inhabit a vast area across northern Eurasia and the Americas
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