312 research outputs found
A review of the impacts of onshore wind energy development on biodiversity
1. The UK Government is committed to the conservation of indigenous biodiversity as well as renewable energy targets. Renewable electricity currently represents nearly 19% of total electricity consumption with a target of 40% by 2020. At present there are 34 operational onshore wind energy developments (> 1 turbine) in Northern Ireland consisting of 313 turbines with a capacity of 533.10MW. In addition there are currently 38 single turbines operating with a capacity of 15.61MW. A further 291 wind energy developments are consented (35 wind developments (> 1 turbine) and 258 single turbines); consisting of 486 turbines with a capacity of 598.12MW (82.77MW from single turbine developments). 2. In Northern Ireland, the Department of Enterprise, Trade and Investment (DETI) is responsible for the promotion of renewable energy whilst the Natural Heritage Directorate (NHD) of the Northern Ireland Environment Agency (NIEA) is responsible for habitat and species conservation targets. Potential conflicts of interest require an assessment of the impact of onshore wind energy developments on biodiversity.3. We reviewed the evidence for the impact of wind energy developments on biodiversity, examining scientific peer-reviewed publications and relevant grey literature, to evaluate effects on habitats (e.g. peatlands), birds, bats and other organisms.4. Our results indicate that onshore wind energy construction and operation can have significant negative effects on local and regional biodiversity. However, the occurrence and magnitude of these effects varies between taxa, species, habitats and site. It should be recognised that publication bias is likely to favour the dissemination of negative results.5. The interaction between onshore wind energy facilities and birds has been the focus of the majority of research to date. However, there has been a recent increase in research on the interaction between bats and wind energy facilities particularly in North America and continental Europe. The recognition of the potential negative impacts on migratory and tree roosting bats has increased in British and Irish research which has focused on their interactions with centralised wind energy development (i.e. wind farms). However, there is limited research on both the immediate and cumulative impacts that single wind turbines may have on biodiversity.6. In general, the impact of wind energy developments can be summarised in 3 categories: i. Displacement through disturbance,ii. Direct mortality through collision with operational turbine blades or powerlines,iii. Direct habitat loss through construction of windfarm infrastructure.www.doeni.gov.uk/niea Impact of wind energy on biodiversityiv7. The majority of studies report varying levels of bird mortality or displacement at onshore wind energy facilities. However, impacts varied within- and between-sites and were highly speciesspecific. Birds of prey (particularly soaring species) were notably vulnerable to collision with rotating blades and direct mortality whilst other aerial species may be vulnerable to barrier effects and/or displacement.8. An increasing body of evidence also indicates that wind energy developments can have a negative impact on bats, which are more vulnerable than previously thought. In particular, tree roosting species and those that migrate appear to be at greatest risk from wind farm related mortality especially if wind energy developments are close to utilized habitats or migratory routes (e.g. ridges). There may also be impacts in the vicinity of bat swarming sites but this has, hitherto, received little or no research.9. Although there is little direct research on the effects of siting wind energy development on peat bogs, inferences can be made about the potential impacts from research into the effects of peat cutting and forestry. Studies suggest that site drainage can be affected which affects the ecology of the bog and also has implications for downstream river catchments and consequently water quality.10. Compared to birds and bats there has been relatively little work conducted on the impacts, if any, on terrestrial mammals, reptiles, amphibians, invertebrates, vascular plants, habitats or ecosystems. Therefore, it is difficult to generalise the wider impacts of wind energy on biodiversity per se
Habitat mediates coevolved but not novel species interactions
This work was supported by the British Ecological Society (SR20/1285).Ongoing recovery of native predators has the potential to alter species interactions, with community and ecosystem wide implications. We estimated the co-occurrence of three species of conservation and management interest from a multi-species citizen science camera trap survey. We demonstrate fundamental differences in novel and coevolved predator–prey interactions that are mediated by habitat. Specifically, we demonstrate that anthropogenic habitat modification had no influence on the expansion of the recovering native pine marten in Ireland, nor does it affect the predator's suppressive influence on an invasive prey species, the grey squirrel. By contrast, the direction of the interaction between the pine marten and a native prey species, the red squirrel, is dependent on habitat. Pine martens had a positive influence on red squirrel occurrence at a landscape scale, especially in native broadleaf woodlands. However, in areas dominated by non-native conifer plantations, the pine marten reduced red squirrel occurrence. These findings suggest that following the recovery of a native predator, the benefits of competitive release are spatially structured and habitat-specific. The potential for past and future landscape modification to alter established interactions between predators and prey has global implications in the context of the ongoing recovery of predator populations in human-modified landscapes.PostprintPeer reviewe
Genetic provenance and best practice woodland management:a case study in native alder (Alnus glutinosa)
Biochemical Determinants of Tissue Regeneration Conversion of one cell type into another: implications for understanding organ development, pathogenesis of cancer and generating cells for therapy
Abstract Metaplasia is the irreversible conversion of one differentiated cell or tissue type into another. Metaplasia usually occurs in tissues that undergo regeneration, and may, in a pathological context, predispose to an increased risk of disease. Studying the conditions leading to the development of metaplasia is therefore of significant clinical interest. In contrast, transdifferentiation (or cellular reprogramming) is a subset of metaplasia that describes the permanent conversion of one differentiated cell type into another, and generally occurs between cells that arise from neighbouring regions of the same germ layer. Transdifferentiation, although rare, has been shown to occur in Nature. New insights into the signalling pathways involved in normal tissue development may be obtained by investigating the cellular and molecular mechanisms in metaplasia and transdifferentiation, and additional identification of key molecular regulators in transdifferentiation and metaplasia could provide new targets for therapeutic treatment of diseases such as cancer, as well as generating cells for transplantation into patients with degenerative disorders. In the present review, we focus on the transdifferentiation of pancreatic cells into hepatocytelike cells, the development of Barrett's metaplasia in the oesophagus, and the cellular and molecular mechanisms underlying both processes
Pure species within a continuum of genetic and morphological variation:Sympatric oaks at the edge of their range
Background and Aims Studies on oaks (Quercus spp.) have often been hampered by taxonomic confusion, a situation further compounded by the occurrence of extensive interspecific hybridization. In the present study, a combination of genetic and morphological analyses was used to examine sympatric populations of Q. petraea and Q. robur at the north-western edge of their ranges in Northern Ireland, since it had previously been suggested that hybridization could facilitate the apparent rapid, long-distance dispersal of oaks following the glaciations. Methods Samples were collected from 24 sites across Northern Ireland that had been previously designated as ancient or semi-natural woodland. Genotypes were obtained from a total of 950 trees using 12 nuclear microsatellite loci, and admixture coefficients were calculated based on a Bayesian clustering approach. Individuals were also classified as Q. petraea, Q. robur or hybrids based on two objective morphometric characters shown previously to delineate pure individuals effectively. Genetically ‘pure’ individuals of both species, as defined by the Bayesian clustering, were also genotyped for five chloroplast microsatellites. Key Results Genetic and morphological analyses both indicated the presence of pure individuals of both species, as well as a continuum of intermediates. There was a good agreement between the molecular and morphological classification, with a generally clear separation between pure individuals. Conclusions Despite millennia of hybridization and introgression, genetically and morphologically pure individuals of both Q. petraea and Q. robur can be found at the edge of their range, where both species occur sympatrically. The high proportion of individuals exhibiting introgression compared with previous studies may reflect the historical role of hybridization in facilitating dispersal following the glaciations. This is further supported by the significantly higher chloroplast diversity in Q. robur compared with Q. petraea
Experimental Conversion of Liver to Pancreas
AbstractBackground: The liver and the pancreas arise from adjacent regions of endoderm in embryonic development. Pdx1 is a key transcription factor that is essential for the development of the pancreas and is not expressed in the liver. The aim of this study was to determine whether a gene overexpression protocol based on Pdx1 would be able to cause conversion of liver to pancreas.Results: We show that a modified form of Pdx1, carrying the VP16 transcriptional activation domain, can cause conversion of liver to pancreas, both in vivo and in vitro. Transgenic Xenopus tadpoles carrying the construct TTR-Xlhbox8-VP16:Elas-GFP were prepared. Xlhbox8 is the Xenopus homolog of Pdx1, the TTR (transthyretin) promoter directs expression to the liver, and the GFP is under the control of an elastase promoter and provides a real-time visible marker of pancreatic differentiation. In the transgenic tadpoles, part or all of the liver is converted to pancreas, containing both exocrine and endocrine cells, while liver differentiation products are lost from the regions converted to pancreas. The timing of events is such that the liver is differentiating by the time Xlhbox8-VP16 is expressed, so we consider this a transdifferentiation event rather than a reprogramming of embryonic development. Furthermore, this same construct will bring about transdifferentiation of human hepatocytes in culture, with formation of both exocrine and endocrine cells.Conclusions: We consider that the conversion of liver to pancreas could be the basis of a new type of therapy for insulin-dependent diabetes. Although expression of the transgene is transient, once the ectopic pancreas is established, it persists thereafter
In vitro culture of embryonic mouse intestinal epithelium: cell differentiation and introduction of reporter genes
BACKGROUND: Study of the normal development of the intestinal epithelium has been hampered by a lack of suitable model systems, in particular ones that enable the introduction of exogenous genes. Production of such a system would advance our understanding of normal epithelial development and help to shed light on the pathogenesis of intestinal neoplasia. The criteria for a reliable culture system include the ability to perform real time observations and manipulations in vitro, the preparation of wholemounts for immunostaining and the potential for introducing genes. RESULTS: The new culture system involves growing mouse embryo intestinal explants on fibronectin-coated coverslips in basal Eagle's medium+20% fetal bovine serum. Initially the cultures maintain expression of the intestinal transcription factor Cdx2 together with columnar epithelial (cytokeratin 8) and mesenchymal (smooth muscle actin) markers. Over a few days of culture, differentiation markers appear characteristic of absorptive epithelium (sucrase-isomaltase), goblet cells (Periodic Acid Schiff positive), enteroendocrine cells (chromogranin A) and Paneth cells (lysozyme). Three different approaches were tested to express genes in the developing cultures: transfection, electroporation and adenoviral infection. All could introduce genes into the mesenchyme, but only to a small extent into the epithelium. However the efficiency of adenovirus infection can be greatly improved by a limited enzyme digestion, which makes accessible the lateral faces of cells bearing the Coxsackie and Adenovirus Receptor. This enables reliable delivery of genes into epithelial cells. CONCLUSION: We describe a new in vitro culture system for the small intestine of the mouse embryo that recapitulates its normal development. The system both provides a model for studying normal development of the intestinal epithelium and also allows for the manipulation of gene expression. The explants can be cultured for up to two weeks, they form the full repertoire of intestinal epithelial cell types (enterocytes, goblet cells, Paneth cells and enteroendocrine cells) and the method for gene introduction into the epithelium is efficient and reliable
Genetic analyses reveal high levels of seed and pollen flow in hawthorn (Crataegus monogyna Jacq.), a key component of hedgerows
Seasonal, geographical, and habitat effects on the diet of a recovering predator population: the European pine marten (Martes martes) in Ireland
- …