1,218 research outputs found
Common Variants in CDKAL1, CDKN2A/B, IGF2BP2, SLC30A8, and HHEX/IDE Genes Are Associated With Type 2 Diabetes and Impaired Fasting Glucose in a Chinese Han Population
OBJECTIVEâ Genome-wide association studies have identified common variants in CDKAL1, CDKN2A/B, IGF2BP2, SLC30A8, HHEX/IDE, EXT2, and LOC387761 loci that significantly increase the risk of type 2 diabetes. We aimed to replicate these observations in a population-based cohort of Chinese Hans and examine the associations of these variants with type 2 diabetes and diabetes-related phenotypes
Backward pion-nucleon scattering
A global analysis of the world data on differential cross sections and
polarization asymmetries of backward pion-nucleon scattering for invariant
collision energies above 3 GeV is performed in a Regge model. Including the
, , and trajectories, we
reproduce both angular distributions and polarization data for small values of
the Mandelstam variable , in contrast to previous analyses. The model
amplitude is used to obtain evidence for baryon resonances with mass below 3
GeV. Our analysis suggests a resonance with a mass of 2.83 GeV as
member of the trajectory from the corresponding Chew-Frautschi
plot.Comment: 12 pages, 16 figure
Power, Connected Coalitions, and Efficiency: Challenges to the Council of the European Union
This article is concerned with challenges to reforming the voting procedures of the Council of the European Union (EU). The next major waves of EU enlargement will cause the Union to increase to a membership of first twenty-one, and then twenty-six or possibly even more states. How does enlargement affect the Council's inherent "capacity to act" under the currently used qualified majority voting rule? It is demon strated here that the expected increase in EU membership will most likely induce a larger "status quo bias" as compared to the present situation in the Council if the crucial majority decision quota is not lowered. In addition, the article is responding to some criticism that has been applied against assessing the leverage of EU governments in one of the EU's most important institutions: the Council of the EU. By resorting to techniques that capture the influence of a priori coalitions on the one hand and "connected coalitions" among EU governments on the otherâapplying n- person cooperative game theoryâthe piece illustrates how the assessment of relative voting leverage in the framework of weighted voting systems may be extended and applied to situations in which the specific distribu tion of members' preferences is known. These calculations are again relevant in the face of the upcoming rounds of EU enlargement and projects for institutional reform.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68064/2/10.1177_019251219902000404.pd
Conservation measures or hotspots of disease transmission? Agri-environment schemes can reduce disease prevalence in pollinator communities
Insects are under pressure from agricultural intensification. To protect pollinators, conservation measures such as the EU agri-environment schemes (AES) promote planting wildflowers along fields. However, this can potentially alter disease ecology by serving as transmission hubs or by diluting infections. We tested this by measuring plantâpollinator interactions and virus infections (DWV-A, DWV-B and ABPV) across pollinator communities in agricultural landscapes over a year. AES had a direct effect on DWV-B, reducing prevalence and load in honeybees, with a tentative general dilution effect on load in early summer. DWV-A prevalence was reduced both under AES and with increasing niche overlap between competent hosts, likely via a dilution effect. By contrast, AES had no impact on ABPV, its prevalence driven by the proportion of bumblebees in the community. Epidemiological differences were also reflected in the virus phylogenies, with DWV-B showing recent rapid expansion, while DWV-A and ABPV showed slower growth rates and geographical population structure. Phylogenies indicate that all three viruses freely circulate across their host populations. Our study illustrates how complex interactions between environmental, ecological and evolutionary factors may influence wildlife disease dynamics. Supporting pollinator nutrition can mitigate the transmission of important bee diseases, providing an unexpected boost to pollinator conservation
The Physics of Cluster Mergers
Clusters of galaxies generally form by the gravitational merger of smaller
clusters and groups. Major cluster mergers are the most energetic events in the
Universe since the Big Bang. Some of the basic physical properties of mergers
will be discussed, with an emphasis on simple analytic arguments rather than
numerical simulations. Semi-analytic estimates of merger rates are reviewed,
and a simple treatment of the kinematics of binary mergers is given. Mergers
drive shocks into the intracluster medium, and these shocks heat the gas and
should also accelerate nonthermal relativistic particles. X-ray observations of
shocks can be used to determine the geometry and kinematics of the merger. Many
clusters contain cooling flow cores; the hydrodynamical interactions of these
cores with the hotter, less dense gas during mergers are discussed. As a result
of particle acceleration in shocks, clusters of galaxies should contain very
large populations of relativistic electrons and ions. Electrons with Lorentz
factors gamma~300 (energies E = gamma m_e c^2 ~ 150 MeV) are expected to be
particularly common. Observations and models for the radio, extreme
ultraviolet, hard X-ray, and gamma-ray emission from nonthermal particles
accelerated in these mergers are described.Comment: 38 pages with 9 embedded Postscript figures. To appear in Merging
Processes in Clusters of Galaxies, edited by L. Feretti, I. M. Gioia, and G.
Giovannini (Dordrecht: Kluwer), in press (2001
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Available and missing data to model impact of climate change on European forests
Climate change is expected to cause major changes in forest ecosystems during the 21st century and beyond. To assess forest impacts from climate change, the existing empirical information must be structured, harmonised and assimilated into a form suitable to develop and test state-of-the-art forest and ecosystem models. The combination of empirical data collected at large spatial and long temporal scales with suitable modelling approaches is key to understand forest dynamics under climate change. To facilitate data and model integration, we identified major climate change impacts observed on European forest functioning and summarised the data available for monitoring and predicting such impacts. Our analysis of c. 120 forest-related databases (including information from remote sensing, vegetation inventories, dendroecology, palaeoecology, eddy-flux sites, common garden experiments and genetic techniques) and 50 databases of environmental drivers highlights a substantial degree of data availability and accessibility. However, some critical variables relevant to predicting European forest responses to climate change are only available at relatively short time frames (up to 10-20 years), including intra-specific trait variability, defoliation patterns, tree mortality and recruitment. Moreover, we identified data gaps or lack of data integration particularly in variables related to local adaptation and phenotypic plasticity, dispersal capabilities and physiological responses. Overall, we conclude that forest data availability across Europe is improving, but further efforts are needed to integrate, harmonise and interpret this data (i.e. making data useable for non-experts). Continuation of existing monitoring and networks schemes together with the establishments of new networks to address data gaps is crucial to rigorously predict climate change impacts on European forests. © 2019 The Author(s
Available and missing data to model impact of climate change on European forests
Climate change is expected to cause major changes in forest ecosystems during the 21st century and beyond. To assess forest impacts from climate change, the existing empirical information must be structured, harmonised and assimilated into a form suitable to develop and test state-of-the-art forest and ecosystem models. The combination of empirical data collected at large spatial and long temporal scales with suitable modelling approaches is key to understand forest dynamics under climate change. To facilitate data and model integration, we identified major climate change impacts observed on European forest functioning and summarised the data available for monitoring and predicting such impacts. Our analysis of c. 120 forest-related databases (including information from remote sensing, vegetation inventories, dendroecology, palaeoecology, eddy-flux sites, common garden experiments and genetic techniques) and 50 databases of environmental drivers highlights a substantial degree of data availability and accessibility. However, some critical variables relevant to predicting European forest responses to climate change are only available at relatively short time frames (up to 10-20 years), including intra-specific trait variability, defoliation patterns, tree mortality and recruitment. Moreover, we identified data gaps or lack of data integration particularly in variables related to local adaptation and phenotypic plasticity, dispersal capabilities and physiological responses. Overall, we conclude that forest data availability across Europe is improving, but further efforts are needed to integrate, harmonise and interpret this data (i.e. making data useable for non-experts). Continuation of existing monitoring and networks schemes together with the establishments of new networks to address data gaps is crucial to rigorously predict climate change impacts on European forests.Peer reviewe
Simulation techniques for cosmological simulations
Modern cosmological observations allow us to study in great detail the
evolution and history of the large scale structure hierarchy. The fundamental
problem of accurate constraints on the cosmological parameters, within a given
cosmological model, requires precise modelling of the observed structure. In
this paper we briefly review the current most effective techniques of large
scale structure simulations, emphasising both their advantages and
shortcomings. Starting with basics of the direct N-body simulations appropriate
to modelling cold dark matter evolution, we then discuss the direct-sum
technique GRAPE, particle-mesh (PM) and hybrid methods, combining the PM and
the tree algorithms. Simulations of baryonic matter in the Universe often use
hydrodynamic codes based on both particle methods that discretise mass, and
grid-based methods. We briefly describe Eulerian grid methods, and also some
variants of Lagrangian smoothed particle hydrodynamics (SPH) methods.Comment: 42 pages, 16 figures, accepted for publication in Space Science
Reviews, special issue "Clusters of galaxies: beyond the thermal view",
Editor J.S. Kaastra, Chapter 12; work done by an international team at the
International Space Science Institute (ISSI), Bern, organised by J.S.
Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke
Talented suppliers? Strategic change and innovation in the UK aerospace industry
The 1990s marked the start of extensive re-structuring in the aerospace industry throughout the world. While the ensuing consolidation among prime contractors has been widely researched, the changes affecting the aerospace supply chain have received less attention. This study focuses on the re-structuring taking place within the supply chain of the UK aerospace industry. The findings point to extensive re-structuring. Unlike most earlier studies the lean supply model was found to be a powerful influence, with suppliers moving away from subcontractor status and instead taking on the mantle of âtalentedâ suppliers. While some of the implications of lean supply, in terms of the dynamics of innovation, were not apparent, there were modest signs of increased process innovation on the part of some suppliers
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