58 research outputs found

    Invasion dynamics of Asian hornet, Vespa velutina (Hymenoptera: Vespidae) : a case study of a commune in south-west France

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    Asian hornet, Vespa velutina Lepeletier nests were discovered in 2007 in Andernos-les-Bains on the south-west coast of France, 3 years after the first reported sightings in France. The number of nests increased in the commune over the following 7 years, despite local authorities enacting a destruction policy. The nests existed in close proximity to one another leading to a high density of over 10 nests per square kilometre in urban areas. New information on the chosen habitat for nests is presented, and the differences between primary and secondary locations are evident, with primary nests mostly occupying buildings and man-made structures, while secondary nests were found on trees. Using Bayesian inference methods, we fit a basic model to the observational data, which allows us to estimate key demographic parameters. This model fit is highly informative for predicting V. velutina spread and colonisation of other at-risk regions, and suggests that local control has a limited impact on the spread of V. velutina once established within a region

    Efficient use of sentinel sites : detection of invasive honeybee pests and diseases in the UK

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    Sentinel sites, where problems can be identified early or investigated in detail, form an important part of planning for exotic disease outbreaks in humans, livestock and plants. Key questions are: how many sentinels are required, where should they be positioned and how effective are they at rapidly identifying new invasions? The sentinel apiary system for invasive honeybee pests and diseases illustrates the costs and benefits of such approaches. Here, we address these issues with two mathematical modelling approaches. The first approach is generic and uses probabilistic arguments to calculate the average number of affected sites when an outbreak is first detected, providing rapid and general insights that we have applied to a range of infectious diseases. The second approach uses a computationally intensive, stochastic, spatial model to simulate multiple outbreaks and to determine appropriate sentinel locations for UK apiaries. Both models quantify the anticipated increase in success of sentinel sites as their number increases and as non-sentinel sites become worse at detection; however, unexpectedly sentinels perform relatively better for faster growing outbreaks. Additionally, the spatial model allows us to quantify the substantial role that carefully positioned sentinels can play in the rapid detection of exotic invasions

    Patterns of democracy: Coalition governance and majoritarian modification in the United Kingdom, 2010–2015

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    The UK is often regarded as the archetype of Westminster democracy and as the empirical antithesis of the power-sharing coalitions of Western Europe. Yet, in recent years a different account has emerged that focuses on the subtler institutional dynamics which limit the executive. It is to this body of scholarship that this article responds, locating the recent chapter of coalition government within the wider context of the UK’s democratic evolution. To do so, the article draws Lijphart’s two-dimensional typology of democracies, developing a refined framework that enables systematic comparison over time. The article demonstrates that between over the course of the 2010-15 Parliament, the UK underwent another period of majoritarian modification, driven by factors including the long-term influence of the constitutional forces unleashed under Labour and the short-term impact of coalition management. The article makes several important contributions, salient in the UK and beyond. Theoretically, it offers a critical rejoinder to debates regarding the relationship between institutional design and democratic performance. Methodologically, it demonstrates that the tools of large-scale comparison can be effectively scaled-down to facilitate withincase analysis. Empirically, it provides a series of conclusions regarding the tenability of the UK’s extant democratic architecture under the weight of pressures to which it continues to be subject

    The Potential and Challenges of Nanopore Sequencing

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    A nanopore-based device provides single-molecule detection and analytical capabilities that are achieved by electrophoretically driving molecules in solution through a nano-scale pore. The nanopore provides a highly confined space within which single nucleic acid polymers can be analyzed at high throughput by one of a variety of means, and the perfect processivity that can be enforced in a narrow pore ensures that the native order of the nucleobases in a polynucleotide is reflected in the sequence of signals that is detected. Kilobase length polymers (single-stranded genomic DNA or RNA) or small molecules (e.g., nucleosides) can be identified and characterized without amplification or labeling, a unique analytical capability that makes inexpensive, rapid DNA sequencing a possibility. Further research and development to overcome current challenges to nanopore identification of each successive nucleotide in a DNA strand offers the prospect of ‘third generation’ instruments that will sequence a diploid mammalian genome for ~$1,000 in ~24 h.Molecular and Cellular BiologyPhysic

    Particularities of allergy in the Tropics

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    Predicting the spread of the Asian hornet (Vespa velutina) following its incursion into Great Britain

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    The yellow-legged or Asian hornet (Vespa velutina) is native to South-East Asia, and is a voracious predator of pollinating insects including honey bees. Since its accidental introduction into South-Western France in 2004, V. velutina has spread to much of western Europe. The presence of V. velutina in Great Britain was first confirmed in September 2016. The likely dynamics following an initial incursion are uncertain, especially the risk of continued spread, and the likely success of control measures. Here we extrapolate from the situation in France to quantify the potential invasion of V. velutina in Great Britain. We find that, without control, V. velutina could colonise the British mainland rapidly, depending upon how the Asian hornet responds to the colder climate in Britain compared to France. The announcement that a second hornet had been discovered in Somerset, increases the chance that the invasion first occurred before 2016. We therefore consider the likely site of first invasion and the probabilistic position of additional founding nests in late 2016 and early 2017. Given the potential dispersion of V. velutina, we conclude that vigilance is required over a large area to prevent the establishment of this threat to the pollinator population

    The Women’s March and the Power of Demonstration

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    The purpose of this project is to study and evaluate the recent Women\u27s March and similar, less known, marches. The Women’s March has resulted in hundreds of thousands of people across the country marching for the rights of woman after the inauguration of President Trump. This march shares similarities to many past demonstrations. In this project, we will examine and compare the recent Women’s March and previous, smaller marches and demonstrations. This project will seek to explore the meaning behind the Women’s March and similar movements, examine the potential impacts of these movements, and determine if there are better methods or procedures that could make these demonstrations more beneficial to their cause

    Short Intramolecular N–H⋯C(carbonyl) Interactions in Mixed-Ligand Molybdenum Hexacarbonyl Derivatives

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    The syntheses and single-crystal structures of Mo(CO)3(phen)(dipy) (1), Mo(CO)3(biquin)(dipy) (2) and Mo(CO)3(dpme)(dipy) (3), (phen = 1,10-phenanthroline, C12H8N2; dipy = 2,2'-dipyridylamine, C10H9N3; biquin = 2,2'-biquinoline, C18H12N2; dpme = 2,2'-dipyridylmethane, C11H10N2) are described. In each case, distorted fac-MoC3N3 octahedral coordination geometries arise for the metal atoms. Short intramolecular N–H…C interactions from the dipy N–H group to a carbonyl carbon atom occur in each structure. Crystal data: 1 (C25H17MoN5O3), Mr = 531.38, monoclinic, P21/n (No. 14), Z = 4, a = 11.0965 (5) Å, b = 13.0586 (6) Å, c = 16.6138 (8) Å, b = 108.324 (1)°, V = 2285.31 (18) Å3, R(F) = 0.035, wR(F2) = 0.070. 2 (C31H21MoN5O3), Mr = 607.47, monoclinic, P21/n (No. 14), Z = 4, a = 11.4788 (6) Å, b = 19.073 (1) Å, c = 11.9881 (6) Å, b = 95.179 (1)°, V = 2613.9 (2) Å3, R(F) = 0.030, wR(F2) = 0.076. 3 (C24H19MoN5O3), Mr = 521.38, monoclinic, P21/n (No. 14), Z = 4, a = 8.4222 (3) Å, b = 21.5966 (9) Å, c = 12.5011 (5) Å, b = 94.065 (1)°, V = 2268.12 (15) Å3, R(F) = 0.025, wR(F2) = 0.065

    The glycoprotein GPNMB attenuates astrocyte inflammatory responses through the CD44 receptor

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    Abstract Background Neuroinflammation is one of the hallmarks of neurodegenerative diseases, such as Parkinson’s disease (PD). Activation of glial cells, including microglia and astrocytes, is a characteristic of the inflammatory response. Glycoprotein non-metastatic melanoma protein B (GPNMB) is a transmembrane glycoprotein that releases a soluble signaling peptide when cleaved by ADAM10 or other extracellular proteases. GPNMB has demonstrated a neuroprotective role in animal models of ALS and ischemia. However, the mechanism of this protection has not been well established. CD44 is a receptor expressed on astrocytes that can bind GPNMB, and CD44 activation has been demonstrated to reduce NFκB activation and subsequent inflammatory responses in macrophages. GPNMB signaling has not been investigated in models of PD or specifically in astrocytes. More recently, genetic studies have linked polymorphisms in GPNMB with risk for PD. Therefore, it is important to understand the role this signaling protein plays in PD. Methods We used data mining techniques to evaluate mRNA expression of GPNMB and its receptor CD44 in the substantia nigra of PD and control brains. Immunofluorescence and qPCR techniques were used to assess GPNMB and CD44 levels in mice treated with MPTP. In vitro experiments utilized the immortalized mouse astrocyte cell line IMA2.1 and purified primary mouse astrocytes. The effects of recombinant GPNMB on cytokine-induced astrocyte activation was determined by qPCR, immunofluorescence, and measurement of nitric oxide and reactive oxygen production. Results Increased GPNMB and CD44 expression was observed in the substantia nigra of human PD brains and in GFAP-positive astrocytes in an animal model of PD. GPNMB treatment attenuated cytokine-induced levels of inducible nitric oxide synthase, nitric oxide, reactive oxygen species, and the inflammatory cytokine IL-6 in an astrocyte cell line and primary mouse astrocytes. Using primary mouse astrocytes from CD44 knockout mice, we found that the anti-inflammatory effects of GPNMB are CD44-mediated. Conclusions These results demonstrate that GPNMB may exert its neuroprotective effect through reducing astrocyte-mediated neuroinflammation in a CD44-dependent manner, providing novel mechanistic insight into the neuroprotective properties of GPNMB
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