335 research outputs found

    Development of porous materials for heterogeneous catalysis: kinetic resolution of epoxides

    Get PDF
    This is a continuation of a research project I have with Andy Borovik of the Department of Chemistry of the UNiversity of Kansas to use X-ray spectroscopy to characterize the metal centers of polymeric materials containing isolated metal sites with useful catalytic and molecular sensing properties. --autor-supplied descriptio

    The spatial and compositional evolution of the Jurassic Ghorveh-Dehgolan plutons of the Zagros Orogen, Iran: SHRIMP zircon U-Pb and Sr and Nd isotope evidence

    Get PDF
    The Ghorveh-Dehgolan plutons of the northern Sanandaj-Sirjan Zone, Zagros Orogen, comprise seven composite intrusive bodies that were generated during northeastward subduction of Neotethys beneath the Iranian sector of the Eurasian plate. Zircon U-Pb SHRIMP dating reveals that the magmatic activity spanned from ~160 to ~140Ma. It started with intrusion of arc-related calc-alkaline mafic to intermediate rocks closely followed by felsic I-type granitoids. This magmatism was post-dated by felsic alkaline A-type granites. In addition to compositional changes over time, the plutons forming the arc young towards the southwest: the north Ghorveh batholith (161±4Ma) and Shanevareh (160±2Ma); Qalaylan (159±3Ma); then central Ghorveh, Galali and Saranjianeh (151±0.2Ma to 148±1Ma); and, lastly, the south Ghorveh batholith (147±3Ma) and Bolbanabad-Havarpan (144±1Ma). Whatever the process driving the changes, be it arc- or ridge-collision with the subducting system, slab roll-back, slab breakoff, subduction initiation transference, etc., the progression from I-type to A-type magmatism appears to mark a significant change from a collisional to an extensional setting in the region in the Late Jurassic. Geochemical and isotopic characteristics of the Ghorveh-Dehgolan plutons indicate that Arabian-Nubian-like crust was an important component of the magmatic sources

    Zircon as a tracer of plumbing processes in an active magmatic system: insights from mingled magmas of the 2010 dome collapse, Montserrat, Lesser Antilles Arc, Caribbean

    Get PDF
    This project has received funding from the European Union's Hori-zon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 749611 (JHS) . We also ac-knowledge funding from the Natural Environment Research Council Isotope Geoscience Facilities Steering Committee, grant IP-1746-1117 (JB) . The work has been financially supported by the Spanish grant CGL 2017-84469-P (JHS) . Funding for open access charge: Universidad de Granada/CBUA. Alexander Varychev at the University of Heidelberg, Germany, and Jeremy Rushton at the British Geological Survey, U.K., are thanked for help with analytical work. Jose Luis Macias is thanked for editorial handling. We are obliged to two anonymous reviewers for the time and effort they took to help us improve the clarity and rigour of our interpretations. 19Soufriere Hills Volcano, Montserrat, erupted from 1995 to 2010, with activity including dome growth, destructive pyroclastic density currents and Vulcanian explosions. Monitoring data, such as gas emissions, show the system is still in a state of unrest. The recent eruptions provide an opportunity to study, in real time, a complex subduction-related subvolcanic transaustal melt-mush reservoir, its magma fluxes, and the timing of crystal and melt storage prior to eruptive paroxysms. How and when mush destabilisation occurs prior to volcanic eruptions continues to be a question of intense debate. Evidence of mafic magma intrusion, a potential eruptive trigger, is preserved in enclaves with quenched and diffuse margins that are mingled with crystal-rich andesite. Here, in this first study of Soufriere Hills Volcano zircon, we report zircon ages and compositions for mafic-intermediate enclaves and host andesites from the most recent dome collapse in 2010 to place temporal constraints on magma reservoir processes. Zircon U-238-Th-230 ages disequilibrium crystallisation ages ranging between c. 2-250 ka constrain the longevity of the magmatic plumbing system. Uniform Hf isotopes, epsilon Hf 11.3 +/- 12 to 14.6 +/- 1.5, indicate invariant compositions that are typical for island arc magma sources. Zircon trace element concentrations and Ti-in-zircon crystallisation temperatures indicate crystallisation in isolated, small-volume, lenses with variable fractions of melt of heterogeneous compositions. We suggest amalgamation of assorted crystal cargoes from these lenses occurred prior to eruption during mush destabilisation triggered by mafic magma recharge. Zircon textures, on the other hand, shed light on recent centimetre-scale magma mingling immediately prior to eruption. Euhedral-subhedral zircon is preferentially preserved in or near quenched contacts of the least-evolved enclave and host andesite. By contrast, reheating of the andesite by the mafic magma recharge in the presence of zircon-undersaturated melts promoted zircon resorption. This led to the formation of subhedral-anhedral corroded zircon that is typical in the host andesite mush. Zircon thus reveals processes ranging from 100,000s of years of andesite storage to short-term partial destruction in response to transient heating and magma mixing events.European Commission 749611Natural Environment Research Council Isotope Geoscience Facilities Steering Committee IP-1746-1117Spanish Government CGL 2017-84469-PUniversidad de Granada/CBU

    Oh, Jeremy Corbyn! Why did Labour Party membership soar after the 2015 general election?

    Get PDF
    This article investigates the remarkable surge in individual membership of the Labour Party after the general election of May 2015, particularly after Jeremy Corbyn was officially nominated as a candidate for the leadership in June of that year. Using both British Election Study and Party Members Project data, we explain the surge by focussing on the attitudinal, ideological and demographic characteristics of the members themselves. Findings suggest that, along with support for the leader and yearning for a new style of politics, feelings of relative deprivation played a significant part: many ‘left-behind’ voters (some well-educated, some less so) joined Labour for the first time when a candidate with a clearly radical profile appeared on the leadership ballot. Anti-capitalist and left-wing values mattered too, particularly for those former members who decided to return to the party

    Why do only some people who support parties actually join them? Evidence from Britain

    Get PDF
    What makes people join a political party is one of the most commonly studied questions in research on party members. Nearly all this research, however, is based on talking to people who have actually joined parties. This article simultaneously analyses surveys of members of political parties in Britain and surveys of non-member supporters of those same parties. This uniquely enables us to model the decision to join parties. The results suggest that most of the elements that constitute the influential ‘General Incentives Model’ are significant. But it also reveals that, while party supporters imagine that selective benefits, social norms and opposing rival parties’ policies are key factors in members’ decisions to join a party, those who actually do so are more likely to say they are motivated by attachments to their party’s values, policies and leaders, as well as by an altruistic desire to support democracy more generally

    Feminizing political parties: women’s party member organizations within European parliamentary parties

    Get PDF
    Party member women’s organizations were early features of party development. While some contemporary studies maintain these are important sites for the substantive representation of women, there is also a claim that they are in decline. Our primary purpose here is to establish the existence of party member women’s organizations – as one test of the first dimension of party feminization: the inclusion of women. We draw on new survey data of 17 European countries provided by Scarrow, Poguntke and Webb. We establish that almost half have a party member women’s organization. The new data also permits analysis of relationships between party member women’s organization and gender quotas for the top party leadership body (National Executive Committee (NEC)), women’s presence among the party leadership and candidate quota rules. Together we see these (i) as a means to establish whether women are marginalized within the party, thereby limiting descriptive representation and (ii) as surrogate measures for women’s substantive representation. We importantly find that the presence of a party member women’s organization does not come at the cost of women’s presence on the NEC. In the final section, we turn our attention to building a new comparative research agenda that more fully addresses substantive representation

    Party finance reform as constitutional engineering? The effectiveness and unintended consequences of party finance reform in France and Britain

    Get PDF
    In both Britain and France, party funding was traditionally characterized by a laissez faire approach and a conspicuous lack of regulation. In France, this was tantamount to a 'legislative vacuum'. In the last two decades, however, both countries have sought to fundamentally reform their political finance regulation regimes. This prompted, in Britain, the Political Parties, Elections and Referendums Act 2000, and in France a bout of 'legislative incontinence' — profoundly transforming the political finance regime between 1988 and 1995. This article seeks to explore and compare the impacts of the reforms in each country in a bid to explain the unintended consequences of the alternative paths taken and the effectiveness of the new party finance regime in each country. It finds that constitutional engineering through party finance reform is a singularly inexact science, largely due to the imperfect nature of information, the limited predictability of cause and effect, and the constraining influence of non-party actors, such as the Constitutional Council in France, and the Electoral Commission in Britain

    Party rules, party resources, and the politics of parliamentary democracies: how parties organize in the 21st Century

    Get PDF
    This article introduces the first findings of the Political Party Database (PPDB) project, a major survey of party organizations in parliamentary and semi-presidential democracies. The project’s first round of data covers 122 parties in 19 countries. In this paper we describe the scope of the database, then investigate what it tells us about contemporary party organization in these countries, focussing on parties’ resources, structures and internal decision-making. We examine organizational patterns by country and party family, and where possible we make temporal comparisons with older datasets. Our analyses suggest a remarkable coexistence of uniformity and diversity. In terms of the major organizational resources on which parties can draw, such as members, staff and finance, the new evidence largely confirms the continuation of trends identified in previous research: i.e., declining membership, but enhanced financial resources and more paid staff. We also find remarkable uniformity regarding the core architecture of party organizations. At the same time, however, we find substantial variation between countries and party families in terms of their internal processes, with particular regard to how internally democratic they are, and in the forms that this democratization takes

    The democratic interface: technology, political organization, and diverging patterns of electoral representation

    Get PDF
    Democracies are experiencing historic disruptions affecting how people engage with core institutions such as the press, civil society organizations, parties, and elections. These processes of citizen interaction with institutions operate as a democratic interface shaping self-government and the quality of public life. The electoral dimension of the interface is important, as its operation can affect all others. This analysis explores a growing left-right imbalance in the electoral connection between citizens, parties, elections, and government. This imbalance is due, in part, to divergent left-right preferences for political engagement, organization, and communication. Support on the right for clearer social rules and simpler moral, racial and nationalist agendas are compatible with hierarchical, leader-centered party organizations that compete more effectively in elections. Parties on the left currently face greater challenges engaging citizens due to the popular meta-ideology of diversity and inclusiveness and demands for direct or deliberative democracy. What we term connective parties are developing technologies to perform core organizational functions, and some have achieved electoral success. However, when connective parties on the left try to develop shared authority processes, online and offline, they face significant challenges competing with more conventionally organized parties on the right

    A novel approach for evaluating contact patterns and risk mitigation strategies for COVID-19 in English primary schools with application of structured expert judgement

    Get PDF
    Personal contacts drive COVID-19 infections. After being closed (23 March 2020) UK primary schools partially re-opened on 1 June 2020 with social distancing and new risk mitigation strategies. We conducted a structured expert elicitation of teachers to quantify primary school contact patterns and how contact rates changed upon re-opening with risk mitigation measures in place. These rates, with uncertainties, were determined using a performance-based algorithm. We report mean number of contacts per day for four cohorts within schools, with associated 90% confidence ranges. Prior to lockdown, younger children (Reception and Year 1) made 15 contacts per day [range 8.35] within school, older children (Year 6) 18 contacts [range 5.55], teaching staff 25 contacts [range 4.55] and non-classroom staff 11 contacts [range 2.27]. After re-opening, the mean number of contacts was reduced by 53% for young children, 62% for older children, 60% for classroom staff and 64% for other staff. Contacts between teaching and non-teaching staff reduced by 80%. The distributions of contacts per person are asymmetric with heavy tail reflecting a few individuals with high contact numbers. Questions on risk mitigation and supplementary structured interviews elucidated how new measures reduced daily contacts in-school and contribute to infection risk reduction
    • …
    corecore