Author
Paul S. Kemp
Other affiliations: National Marine Fisheries Service, University of Stirling, National Oceanic and Atmospheric Administration ...read more
Bio: Paul S. Kemp is an academic researcher from University of Southampton. The author has contributed to research in topics: Population & Salmo. The author has an hindex of 34, co-authored 119 publications receiving 3785 citations. Previous affiliations of Paul S. Kemp include National Marine Fisheries Service & University of Stirling.
Topics: Population, Salmo, Weir, Trout, Brown trout
Papers published on a yearly basis
Papers
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TL;DR: It is prudent to accept that although manipulations of habitat may appear to be beneficial when considered locally, they should be measured and assessed where possible in terms of the production of returning adults and/or high quality smolts.
604 citations
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TL;DR: In this paper, the authors identify the causal mechanisms that underpin the observed negative response exhibited by fish populations to enhanced fine sediment loads, and the variability across different fish species across different families.
Abstract: Elevated fine sediment input from terrestrial and aquatic sources as a result of anthropogenic activity is widely recognized to impact negatively on aquatic ecosystems. In rivers, freshwater fish are exposed to a range of impacts resulting from fine sediment pressures. To date, research on the effects of fine sediments on fish has been concentrated within relatively few families, notably the salmonidae. This paper reviews the literature describing indirect and direct impacts of fine sediment on freshwater fish as a contribution towards enhancing the understanding of the impacts of anthropogenic activities on freshwater ecosystems. We identify the causal mechanisms that underpin the observed negative response exhibited by fish populations to enhanced fine sediment loads, and the variability across different fish species.
457 citations
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Polytechnic University of Milan1, University of Lyon2, Swansea University3, University of Padua4, Technical University of Denmark5, Polish Academy of Sciences6, Leibniz Association7, University of Oviedo8, Oregon State University9, University of Southampton10, Durham University11, University College Cork12, Marine Institute of Memorial University of Newfoundland13, University of Kent14, University of Murcia15, Technical University of Madrid16, The Nature Conservancy17, François Rabelais University18, University of Strasbourg19, Princeton University20
TL;DR: There are at least 1.2 million instream barriers in 36 European countries, 68 per cent of which are structures less than two metres in height that are often overlooked, and the main predictors of barrier density are agricultural pressure, density of river-road crossings, extent of surface water and elevation.
Abstract: Rivers support some of Earth's richest biodiversity1 and provide essential ecosystem services to society2, but they are often fragmented by barriers to free flow3. In Europe, attempts to quantify river connectivity have been hampered by the absence of a harmonized barrier database. Here we show that there are at least 1.2 million instream barriers in 36 European countries (with a mean density of 0.74 barriers per kilometre), 68 per cent of which are structures less than two metres in height that are often overlooked. Standardized walkover surveys along 2,715 kilometres of stream length for 147 rivers indicate that existing records underestimate barrier numbers by about 61 per cent. The highest barrier densities occur in the heavily modified rivers of central Europe and the lowest barrier densities occur in the most remote, sparsely populated alpine areas. Across Europe, the main predictors of barrier density are agricultural pressure, density of river-road crossings, extent of surface water and elevation. Relatively unfragmented rivers are still found in the Balkans, the Baltic states and parts of Scandinavia and southern Europe, but these require urgent protection from proposed dam developments. Our findings could inform the implementation of the EU Biodiversity Strategy, which aims to reconnect 25,000 kilometres of Europe's rivers by 2030, but achieving this will require a paradigm shift in river restoration that recognizes the widespread impacts caused by small barriers.
245 citations
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TL;DR: Optimisation modelling offers a more robust approach for efficiently prioritising decision making in river restoration planning, allowing decision makers to account for key uncertainties and effectively balance multiple, possibly competing, environmental and socioeconomic goals and constraints.
Abstract: Techniques for assessing the impact of structural barriers on fish passage and for prioritising restoration actions are reviewed. Current survey methodologies are biased towards specific structures, primarily culverts and economically significant fish. Assessment criteria are often based on swimming capabilities of upstream migrating adult salmonids, while ignoring other life-stages, non-salmonid species, downstream migration and behaviour. The development of comprehensive and centrally owned geospatial inventories of barriers is essential. The collection, maintenance and dissemination of pertinent structural and environmental data can be technically, logistically and financially challenging. Standardised procedures are needed to rapidly and cost-effectively survey large numbers of barriers over wide geographic areas. The prioritisation of barrier repair and removal projects is most often based on simple cost-benefit analysis, whereby individual barriers are scored based on a set of assessment criteria and then ranked in order of priority. The benefits of using scoring-and-ranking systems, however, are unacceptably low because they consider barriers independently, thereby ignoring the cumulative, non-additive impacts produced by multiple, spatially interconnected structures. Optimisation modelling offers a more robust approach for efficiently prioritising decision making in river restoration planning, allowing decision makers to account for key uncertainties and effectively balance multiple, possibly competing, environmental and socioeconomic goals and constraints.
241 citations
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TL;DR: In patients in whom there was diagnostic uncertainty between degenerative parkinsonism and non-degenerative tremor disorders, baseline imaging with the dopamine transporter ligand [(123)I]ioflupane (DaTscan™) has shown 78% sensitivity and 97% specificity with reference to clinical diagnosis at 3 years, versus 93% and 46%, respectively, for baseline clinical diagnosis.
Abstract: Diagnosis of neurological and psychiatric conditions associated with disturbances of dopaminergic functioning can be challenging, especially in the early stages, and may be assisted with biomarkers such as dopamine system imaging. Distinguishing between Alzheimer's disease and dementia with Lewy bodies is a major diagnostic challenge. Clinical diagnosis of Parkinson's disease is straightforward with classic presentation, but accurate distinction among Parkinsonian variants may be difficult; non-Parkinson's disease conditions are commonly misdiagnosed as Parkinson's disease, and ~20% of patients with Parkinson's disease are not clinically diagnosed despite coming to medical attention. Early and accurate diagnosis is desirable to improve management. Imaging of the dopamine transporter using single-photon emission computed tomography may be of particular utility in this regard. Abnormal imaging indicates underlying nigrostriatal neurodegeneration, supportive of a diagnosis of Parkinson's disease, atypical parkinsonism or dementia with Lewy bodies, and identifies patient groups in whom dopaminergic therapy may be beneficial. Normal imaging supports diagnosis of a condition not involving nigrostriatal neurodegeneration such as Alzheimer's disease, essential tremor or drug-induced parkinsonism and hence a different therapeutic approach. In patients in whom there was diagnostic uncertainty between degenerative parkinsonism and non-degenerative tremor disorders, baseline imaging with the dopamine transporter ligand [(123)I]ioflupane (DaTscan™) has shown 78% sensitivity and 97% specificity with reference to clinical diagnosis at 3 years, versus 93% and 46%, respectively, for baseline clinical diagnosis. In a Phase III trial of [(123)I]ioflupane in patients with initial clinical diagnosis of probable or possible dementia with Lewy bodies or non-Lewy body dementia, mean specificity for excluding non-Lewy body dementia (predominantly Alzheimer's disease) was 90.4%. Using clinical diagnosis as a reference against which to assess sensitivity and specificity of dopamine transporter imaging is a limitation, but definitive diagnosis via pathological confirmation is generally not feasible. In a series of patients with post-mortem brain examination, imaging using [(123)I]ioflupane has demonstrated higher sensitivity (88%) and specificity (100%) for differentiating dementia with Lewy bodies from non-Lewy body dementia than clinical diagnosis (75% and 42%, respectively). Dopaminergic system imaging may be particularly valuable in patients with clinically inconclusive parkinsonism or a clinical diagnosis of possible dementia with Lewy bodies; it is not helpful in differentiating between Parkinson's disease and atypical parkinsonism, although postsynaptic dopaminergic imaging may be of utility. Other potential uses of dopamine transporter imaging include identification of patients with premotor Parkinson's disease, monitoring disease progression in testing novel therapeutics, and as an inclusion criterion for entry into clinical trials.
193 citations
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TL;DR: In this article, the authors present a document, redatto, voted and pubblicato by the Ipcc -Comitato intergovernativo sui cambiamenti climatici - illustra la sintesi delle ricerche svolte su questo tema rilevante.
Abstract: Cause, conseguenze e strategie di mitigazione Proponiamo il primo di una serie di articoli in cui affronteremo l’attuale problema dei mutamenti climatici. Presentiamo il documento redatto, votato e pubblicato dall’Ipcc - Comitato intergovernativo sui cambiamenti climatici - che illustra la sintesi delle ricerche svolte su questo tema rilevante.
4,187 citations
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3,213 citations
01 Jan 2016
TL;DR: This application applied longitudinal data analysis modeling change and event occurrence will help people to enjoy a good book with a cup of coffee in the afternoon instead of facing with some infectious virus inside their computer.
Abstract: Thank you very much for downloading applied longitudinal data analysis modeling change and event occurrence. As you may know, people have look hundreds times for their favorite novels like this applied longitudinal data analysis modeling change and event occurrence, but end up in malicious downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious virus inside their computer.
2,102 citations
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McGill University1, WWF-India2, University of Basel3, WWF-Canada4, The Nature Conservancy5, University of Nevada, Reno6, Delft University of Technology7, Konstanz University of Applied Sciences8, King's College London9, Umeå University10, Swedish University of Agricultural Sciences11, University of Washington12, Harvard University13, University of Wisconsin-Madison14, Michigan Technological University15, Conservation International16, Stanford University17, Free University of Berlin18, Leibniz Association19, University of Tübingen20
TL;DR: A comprehensive assessment of the world’s rivers and their connectivity shows that only 37 per cent of rivers longer than 1,000 kilometres remain free-flowing over their entire length.
Abstract: Free-flowing rivers (FFRs) support diverse, complex and dynamic ecosystems globally, providing important societal and economic services. Infrastructure development threatens the ecosystem processes, biodiversity and services that these rivers support. Here we assess the connectivity status of 12 million kilometres of rivers globally and identify those that remain free-flowing in their entire length. Only 37 per cent of rivers longer than 1,000 kilometres remain free-flowing over their entire length and 23 per cent flow uninterrupted to the ocean. Very long FFRs are largely restricted to remote regions of the Arctic and of the Amazon and Congo basins. In densely populated areas only few very long rivers remain free-flowing, such as the Irrawaddy and Salween. Dams and reservoirs and their up- and downstream propagation of fragmentation and flow regulation are the leading contributors to the loss of river connectivity. By applying a new method to quantify riverine connectivity and map FFRs, we provide a foundation for concerted global and national strategies to maintain or restore them. A comprehensive assessment of the world’s rivers and their connectivity shows that only 37 per cent of rivers longer than 1,000 kilometres remain free-flowing over their entire length.
1,071 citations