59 research outputs found

    The European Union in disequilibrium: new intergovernmentalism, postfunctionalism and integration theory in the post-Maastricht period

    Get PDF
    The crises that weigh heavily on the European Union (EU) in the 2010s have underlined the continued importance of integration theory, albeit in ways that go beyond classic debates. Postfunctionalism, in particular, has shown how European integration and its problems stand on shifting political cleavages. And yet, postfunctionalist claims that such changes would create a constraining dissensus in the EU rests uneasily with the intensification of European integration since the Maastricht Treaty was signed. This article offers a new intergovernmentalist explanation of this puzzle, which shows how mainstream governing parties have circumvented rather than being constrained by Eurosceptic challenger parties and challenger governments. The result, it contends, is not a constraining but a destructive dissensus that adds to the EU’s political disequilibrium. Understanding the persistence of this disequilibrium and its potential to unwind disruptively is a key challenge for contemporary integration theory

    Atmospheric sources, transport and deposition of mercury in Michigan: Two years of event precipitation

    Full text link
    To assess the sources, transport and deposition of atmospheric mercury (Hg) in Michigan, a multi-site network was implemented in which Hg concentrations in event precipitation and ambient samples (vapor and participate phases) were determined. Results from the analysis of 2 years of event precipitation samples for Hg are reported here. The volume-weighted average Hg concentration in precipitation was 7.9, 10.8 and 10.2 ng/L for the Pellston, South Haven and Dexter sites, respectively. Yearly wet deposition of Hg for 1992–93 and 1993–94 was 5.8 and 5.5 ÎŒg/m 2 at Pellston, 9.5 and 12.7 ÎŒg/m 2 at South Haven and 8.7 and 9.1 ÎŒg/m at Dexter. A spatial gradient in both the Hg concentration and wet deposition was observed. Northern Michigan received almost half the deposition of Hg recorded at the southern Michigan sites. The concentration of Hg in precipitation exhibited a strong seasonal behavior with low values of 1.0 to 2.0 ng/L in winter and maximum values greater than 40 ng/L in summer. The spring, summer and autumn precipitation accounted for 89 to 91% of the total yearly Hg deposition. Mixed-layer back trajectories were calculated for each precipitation event to investigate the meteorological history and transport from potential Hg source regions. Elevated Hg concentrations were observed with air mass transport from the west, southwest, south, and southeast. At each of the sites precipitation events for which the Hg concentration was in the 90th and 10th percentile were-analyzed for trace elements by ICP-MS to investigate source impacts.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43912/1/11270_2005_Article_BF01189668.pd

    Deep molluscan phylogeny: synthesis of palaeontological and neontological data

    No full text
    The position of the earliest-derived living molluscs, the Polyplacophora (chitons) and shell-less vermiform Aplacophora, remains highly contentious despite many morphological, developmental and molecular studies of extant organisms. These two groups are thought to represent either a basal molluscan grade or a clade (Aculifera) sister to the ‘higher’ molluscs (Conchifera). These incompatible hypotheses result in very different predictions about the earliest molluscs. A new cladistic analysis incorporating both Palaeozoic and extant molluscs is presented here. Our results support the monophyly of Aculifera and suggest that extant aplacophorans and polyplacophorans both derive from a disparate group of multivalved molluscs in two major clades. Reanalysis of the critical Ordovician taxon ‘Helminthochiton’ thraivensis shows that this animal lacks a true foot despite bearing polyplacophoran-like valves. Its position within our phylogenetic reconstruction indicates that many fossil ‘polyplacophorans’ in the order Palaeoloricata are likely to represent footless stem-group aplacophorans. ‘H.’ thraivensis and similar forms such as Acaenoplax may be morphological stepping stones between chitons and the shell-less aplacophorans. Our results imply that crown-group molluscan synapomorphies include serial repetition, the presence of a foot, a mineralized scleritome and a creeping rather than worm-like mode of life
    • 

    corecore