362 research outputs found

    Can the mid-Holocene provide suitable models for rewilding the landscape in Britain?

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    Palaeoecologists have been encouraging us to think about the relevance of the Holocene fossil record for nature conservation for many years (e.g. Buckland 1993) but this information seems slow to filter through to the conservation community. Indeed, Willis et al. (2005) report that recently published biodiversity reports and policy documents rarely look back more than 50 years and may ignore the historical context entirely. This has been a lost opportunity for understanding ecological systems. Many natural processes occur over timescales that confound our attempts to understand them, so the vast temporal perspective provided by palaeoecological studies can provide important guidance for nature conservation (Willis & Birks 2006). However, accurate vegetation mapping is difficult enough in modern landscapes (Cherrill & McLean 1999), so the challenge of describing prehistoric environments is immeasurably greater. Nevertheless, pioneering work in the mid 20th century showed that pollen and spores extracted from peat bogs were so perfectly preserved thatthey could be used to demonstrate sequences of vegetation change since the last glaciation (Godwin 1956). Since then, the science has burgeoned: ancient deposits of beetles, snails, fungal spores and plant macrofossils add to the picture, as does the chemistry of ancient lake sediments (Bell & Walker 2004). Many questions still remain to be answered by this fascinating research and one aspect has received considerable attention in the last decade. This concerns the nature of the ‘primeval’ landscapes, in other words our understanding of natural systems prior to significant human impact. The debate was kindled by a thesis by the Dutch forest ecologist Frans Vera in 2000 (see also Vera & Buissink 2007). Vera effectively challenged established views about the primeval landscapes and argued that the refutation, and the resulting alternative landscape models, had critical importance for modern conservation practice. Vera’s thesis is focused on the pre-Neolithic (ca 8000-5000bp) landscape in the lowlands of central and western Europe, with the assumption that this period represents an almost pristine or ‘natural’ state which should provide a suitable conservation benchmark. Vera contends (i) that this landscape was not closed woodland but a relatively open park-like mosaic of wood and grassland,and (ii) that large wild herbivores were an essential driving force behind woodland-grassland vegetation cycles. The advocacy in his argument and the timing of the publication, when grazingwas seen as increasingly important in conservation in Europe, have combined to raise the profile of this issue. If Vera is correct, the open park-like landscapes were inherited rather than created by people; this may have implications for conservation practice in Europe. The adoption of Vera’s ideas into conservation management plans in the UK (see Box 1) gives an indication of the influence that this work has had. Indeed, Vera’s ideas have been described as a ‘challenge to orthodox thinking’ (Miller 2002) and considerable debate has been stimulated centering on the ecological validity of Vera’s hypothesis and its relevance for modern conservation. In this article, we attempt to address these issues on the basis of results from a literature review, web-debate and discussions with Dutch and British ecologists, prepared for English Nature with a view to informing conservation strategies (Hodder & Bullock 2005a)

    Using the UK general offender database as a means to measure and analyse Organised Crime.

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    Purpose Organised Crime is notoriously difficult to define and measure, resulting in limited empirical evidence to inform policy makers and practitioners. This study explores the feasibility of identifying a greater number of organized crime offenders, currently captured (but invisible), within an existing national general crime database. Methodology All 2.1 million recorded offenders, captured over a four year period on the UK Police National Computer (PNC), were filtered across three criteria associated with organized crime (co-offending, commission of specific offences, three years imprisonment or more). The 4109 ‘organized crime’ offenders, identified by the process, were compared with ‘general’ and ‘serious’ offender control groups across a variety of personal and demographic variables. Findings Organized crime prosecutions are not random but concentrate in specific geographic areas and constitute 0.2% of the offender population. Offenders can be differentiated from general crime offenders on such measures as: criminal onset age, offence type and criminal recidivism. Research implications Using an offence based methodology, rather than relying on offenders identified through police proactive investigations, can provide empirical information from existing data sets, across a diverse range of legislative areas and cultures. This allows academics to enhance their analysis of organized crime, generating richer evidence on which policy makers and practitioners can more effectively deliver preventative and disruptive tactics. Originality This is the first time an ‘offence based’ methodology has been used in differentiating organised crime from other offenders in a general crime database

    Sheep Updates 2003 - Meat

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    This session covers seven papers from different authors: 1. Economic analysis of using terminal sires in a self replacing Merino flock Lucy Anderton, Department of Agriculture Western Australia, Katanning 2. Is the mating of ewe weaners an option for increasing the numbers of lambs in WA? Rob Davidson University of WA, Crawley and Keith Croker Department of Agriculture Western Australia, South Perth 3.Dehydration of lambs at the time of slaughter Robin Jacob, School of Veterinary and Biomedical Sciences, Murdoch University 4.Feeding prime lambs for slaughter Rachel Kirby, Outback Solutions 5. Live sheep export R&D Steve Meerwald, Wellard Rural Exports 6. Confinement feeding sheep in Western Australia John Milton, The University of Western Australia 7. Sheepmeat eating quality - affects of animal age, finishing and processing David Pethick, School of Veterinary and Biomedical Sciences, Murdoch Universit

    Quantifying the impact of an extreme climate event on species diversity in fragmented temperate forests: the effect of the October 1987 storm on British broadleaved woodlands

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    1. We report the impact of an extreme weather event, the October 1987 severe storm, on fragmented woodlands in southern Britain. We analysed ecological changes between 1971 and 2002 in 143 200-m2 plots in 10 woodland sites exposed to the storm with an ecologically equivalent sample of 150 plots in 16 non-exposed sites. In both years, understorey species-richness, species composition, soil pH and woody basal area of the tree and shrub canopy were measured. 2. We tested the hypothesis that the storm had deflected sites from the wider national trajectory of an increase in woody basal area and reduced understorey species-richness associated with ageing canopies and declining woodland management. We also expected storm disturbance to amplify the background trend of increasing soil pH, a UK-wide response to reduced atmospheric sulphur deposition. Path analysis was used to quantify indirect effects of storm exposure on understorey species richness via changes in woody basal area and soil pH. 3. By 2002, storm exposure was estimated to have increased mean species richness per 200 m2 by 32%. Woody basal area changes were highly variable and did not significantly differ with storm exposure. 4. Increasing soil pH was associated with a 7% increase in richness. There was no evidence that soil pH increased more as a function of storm exposure. Changes in species richness and basal area were negatively correlated: a 3.4% decrease in richness occurred for every 0.1-m2 increase in woody basal area per plot. 5. Despite all sites substantially exceeding the empirical critical load for nitrogen deposition, there was no evidence that in the 15 years since the storm, disturbance had triggered a eutrophication effect associated with dominance of gaps by nitrophilous species. 6. Synthesis: Although the impacts of the 1987 storm were spatially variable in terms of impacts on woody basal area, the storm had a positive effect on understorey species richness. There was no evidence that disturbance had increased dominance of gaps by invasive species. This could change if recovery from acidification results in a soil pH regime associated with greater macronutrient availability

    Improved detection of global copy number variation using high density, non-polymorphic oligonucleotide probes

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    <p>Abstract</p> <p>Background</p> <p>DNA sequence diversity within the human genome may be more greatly affected by copy number variations (CNVs) than single nucleotide polymorphisms (SNPs). Although the importance of CNVs in genome wide association studies (GWAS) is becoming widely accepted, the optimal methods for identifying these variants are still under evaluation. We have previously reported a comprehensive view of CNVs in the HapMap DNA collection using high density 500 K EA (Early Access) SNP genotyping arrays which revealed greater than 1,000 CNVs ranging in size from 1 kb to over 3 Mb. Although the arrays used most commonly for GWAS predominantly interrogate SNPs, CNV identification and detection does not necessarily require the use of DNA probes centered on polymorphic nucleotides and may even be hindered by the dependence on a successful SNP genotyping assay.</p> <p>Results</p> <p>In this study, we have designed and evaluated a high density array predicated on the use of non-polymorphic oligonucleotide probes for CNV detection. This approach effectively uncouples copy number detection from SNP genotyping and thus has the potential to significantly improve probe coverage for genome-wide CNV identification. This array, in conjunction with PCR-based, complexity-reduced DNA target, queries over 1.3 M independent NspI restriction enzyme fragments in the 200 bp to 1100 bp size range, which is a several fold increase in marker density as compared to the 500 K EA array. In addition, a novel algorithm was developed and validated to extract CNV regions and boundaries.</p> <p>Conclusion</p> <p>Using a well-characterized pair of DNA samples, close to 200 CNVs were identified, of which nearly 50% appear novel yet were independently validated using quantitative PCR. The results indicate that non-polymorphic probes provide a robust approach for CNV identification, and the increasing precision of CNV boundary delineation should allow a more complete analysis of their genomic organization.</p
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