444 research outputs found

    Comparison of the precision of smooth pursuit in humans and head unrestrained monkeys

    Get PDF
    Direct comparison of results of humans and monkeys is often complicated by differences in experimental conditions. We replicated in head unrestrained macaques experiments of a recent study comparing human directional precision during smooth pursuit eye movements (SPEM) and saccades to moving targets (Braun & Gegenfurtner, 2016). Directional precision of human SPEM follows an exponential decay function reaching optimal values of 1.5°-3° within 300 ms after target motion onset, whereas precision of initial saccades to moving targets is slightly better. As in humans, we found general agreement in the development of directional precision of SPEM over time and in the differences between directional precision of initial saccades and SPEM initiation. However, monkeys showed overall lower precision in SPEM compared to humans. This was most likely due to differences in experimental conditions, such as in the stabilization of the head, which was by a chin and a head rest in human subjects and unrestrained in monkeys.

    Energy security and shifting modes of governance

    Get PDF
    The concept of energy security fits uneasily into contemporary security debates. It is neither a clearly traditional nor a fully ‘non-traditional’ security issue. There are also limits to the social constructedness of the concept. This article argues that, while it is important to identify the differing securitizations of energy, these must be contextualized within the material realities and the differing historical modes of governance of the political economy of resources. This is essential for understanding the differing meanings accorded to energy security, the shifting modes through which energy is governed, and the extent to which energy security concerns drive international politics. In this context, contemporary concerns over energy security have both material and ideological dimensions: anxiety over the dual shift of power from West to East and from resource-importing to resource-exporting countries; and concern over the normative weakening of the neo-liberal mode of energy governance

    The semi-classical expansion and resurgence in gauge theories: new perturbative, instanton, bion, and renormalon effects

    Get PDF
    We study the dynamics of four dimensional gauge theories with adjoint fermions for all gauge groups, both in perturbation theory and non-perturbatively, by using circle compactification with periodic boundary conditions for the fermions. There are new gauge phenomena. We show that, to all orders in perturbation theory, many gauge groups are Higgsed by the gauge holonomy around the circle to a product of both abelian and nonabelian gauge group factors. Non-perturbatively there are monopole-instantons with fermion zero modes and two types of monopole-anti-monopole molecules, called bions. One type are "magnetic bions" which carry net magnetic charge and induce a mass gap for gauge fluctuations. Another type are "neutral bions" which are magnetically neutral, and their understanding requires a generalization of multi-instanton techniques in quantum mechanics - which we refer to as the Bogomolny-Zinn-Justin (BZJ) prescription - to compactified field theory. The BZJ prescription applied to bion-anti-bion topological molecules predicts a singularity on the positive real axis of the Borel plane (i.e., a divergence from summing large orders in peturbation theory) which is of order N times closer to the origin than the leading 4-d BPST instanton-anti-instanton singularity, where N is the rank of the gauge group. The position of the bion--anti-bion singularity is thus qualitatively similar to that of the 4-d IR renormalon singularity, and we conjecture that they are continuously related as the compactification radius is changed. By making use of transseries and Ecalle's resurgence theory we argue that a non-perturbative continuum definition of a class of field theories which admit semi-classical expansions may be possible.Comment: 112 pages, 7 figures; v2: typos corrected, discussion of supersymmetric models added at the end of section 8.1, reference adde

    Queen Elizabeth’s Leadership Abroad: The Netherlands in the 1570s

    Get PDF
    In 1576, after Edmund Grindal, archbishop of Canterbury, presumed to lecture Queen Elizabeth on the importance of preaching and on her duty to listen to such lectures, his influence diminished precipitously, and leadership of the established English church fell to Bishop Aylmer. Grindal’s friends on the queen’s Privy Council, “forward” Calvinists (or ultra-Protestants), were powerless to save him from the consequences of his indiscretion, which damaged the ultras’ other initiatives’ chances of success. This paper concerns one of those initiatives. From the late 1560s, they urged their queen “actively” to intervene in the Dutch wars. They collaborated with Calvinists on the Continent who befriended Prince William of Orange and who hoped to help him hold together a coalition of religiously reformed and Roman Catholic insurgents in the seventeen provinces of the Low Countries. The English ultra-Protestants would have their government send money, munitions, and men in arms to the Netherlands, to tip the balance against viceroys sent by King Philip II of Spain. Grindal’s setback undermined the English Calvinists’ efforts to form an Anglo-Dutch alliance which, they assumed, would boost the prospects for an international Protestant league. Yet Elizabeth did assist the Dutch as they wrestled with decisions forced on them by developments in the Netherlands during the 1570s, and she did so more consistently and more cleverly than many historians of Tudor diplomacy have thought. Two competing assessments determine the way questions are formulated in the study of the queen’s and regime’s Dutch diplomacy. The general consensus is that she was indecisive and inconsistent. Paul Hammer characterizes Elizabeth’s responses to the crises in the Low Countries as a “zigzag of different” (“even contradictory”) maneuvers. Wallace McCaffrey and R. B. Wernham agree that England’s “hesitations and gyrations” do not pass as coherent, creditable policy. Charles Wilson scolds Elizabeth for being timid and tepid--incapable of enthusiasm for “a great cause.” But David J.B. Trim’s striking counterthrust depicts the queen’s overtures to Netherlanders as part of her courageous – and “confessionally driven” – foreign policy; Trim replaces “hesitation” and “zigzag” with a coherent “Protestant programme of action prioritized by the Elizabethan government” with the aim of improving prospects for “Calvinist internationalism.” What follows is an alternative to all these characterizations, one that, as noted, finds evidence for greater consistency and coherence in Elizabeth’s leadership and less confessional “drive.” That she would have been uneasy around religious extremists ought not to astonish us; her father’s, step-brother’s, and step-sister’s reigns as well as the start of her own were disturbed by zealous subjects, who were bent on shoring up or dismantling the realm’s religious settlements

    Lacerated Lips and Lush Landscapes: Constructing This-Worldly Theological Identities in the Otherworld

    Get PDF
    When Irenaeus juxtaposed tradition and heresy, he moved away from the Pauline usage, which centered primarily upon incorrect behavior (See 1 Cor 11: 19, Gal 5 :20). lrenaeus\u27 definition of heresy, however, does not indicate that all early Christians prioritized belief over behavior, or even maintained orthodoxy and orthopraxis as separate categories. In the otherworldly spaces of the apocryphal apocalypses doxa and praxis seem to be intertwined, and little or no distinction is made between belief and behavior. Instead, in the Otherworld the categories of primary importance are righteous/unrighteous, good/evil, Christian/Other. The Otherworld is a place in which sins can be sorted and the identity markers which might have been overlooked or are difficult to see in this world can be seen more clearly. And yet, we are left to wonder how that otherworldly clarity maps onto the lived experience of the ancient audiences of these apocalypses. Thus, we will begin by reflecting upon the ability of these apocalyptic texts to create (and recreate) Christian identity by either describing real categories of people, or by creating the categories themselves, and so prescribing reality. In each of the apocalypses that we will discuss the reader learns that his or her identity is determined for all of eternity by the choices that are made in this world. In this regard, each depiction of the otherworld establishes its own identity markers, isolating certain beliefs and behaviors as distinctively Christian. What is startling about the definitions of Christian belief and practice that emerge from each text is that they are rather expansive, covering far more territory than any creed or council. Our discussion will demonstrate that while creedal definitions of orthodoxy ( as well as the apocalyptic definitions of correct belief that mirror them) were often aimed at labeling specific groups as other, the apocalyptic depictions of the otherworld were attempting to be either exhaustive or open-ended, imagining a host of practices that could be used to frame Christian identity. In these imaginary spaces, the theological identities that were crafted could not simply be summarized by simple binaries like orthodoxy/heterodoxy, oppressed/oppressor, or even sinner/sinless. Instead, the apocalyptic visions, which on the surface seem to deal in dichotomies, paradoxically proliferate a range of Christian practices

    Onderzoek naar brandveiligheid voor dieren in veestallen = Study regarding fire safety of barns for farm animals

    Get PDF
    Study regarding bottle necks in fire safety of barns for farm animals and possible improvements, inter alia in legislation

    Strategic Sensemaking and Political Connections in Unstable Institutional Contexts

    Get PDF
    Emerging economies are often characterized by pervasive institutional changes and resultant institutional voids. In the absence of strong formal institutions, firms rely on informal institutions to fill these voids. This article argues that the process of sensemaking for firms in turbulent environments is continuous and dependent on cyclical adjustments connecting performance via a feedback loop to scanning and interpretation. Far from being a one-time occurrence, environmental sensemaking is a process operating in accord with continuous environmental changes. This study’s findings derive from an in-depth analysis of a Russian pharmaceutical firm and an Indian telecommunications firm, and demonstrate that entrepreneurs make sense and gain legitimacy through political connections. The study further finds that improvements in institutional environments reduce the salience of political networks, thereby creating a choice for firms to rely on formed market mechanisms or continue along the path of political connections that evolve to public–private partnerships

    Functional and expression analysis of the metal-inducible dmeRF system from Rhizobium legumionosarum bv. viciae

    Full text link
    A gene encoding a homolog to the cation diffusion facilitator protein DmeF from Cupriavidus metallidurans has been identified in the genome of Rhizobium leguminosarum UPM791. The R. leguminosarum dmeF gene is located downstream of an open reading frame (designated dmeR) encoding a protein homologous to the nickel- and cobalt-responsive transcriptional regulator RcnR from Escherichia coli. Analysis of gene expression showed that the R. leguminosarum dmeRF genes are organized as a transcriptional unit whose expression is strongly induced by nickel and cobalt ions, likely by alleviating the repressor activity of DmeR on dmeRF transcription. An R. leguminosarum dmeRF mutant strain displayed increased sensitivity to Co(II) and Ni(II), whereas no alterations of its resistance to Cd(II), Cu(II), or Zn(II) were observed. A decrease of symbiotic performance was observed when pea plants inoculated with an R. leguminosarum dmeRF deletion mutant strain were grown in the presence of high concentrations of nickel and cobalt. The same mutant induced significantly lower activity levels of NiFe hydrogenase in microaerobic cultures. These results indicate that the R. leguminosarum DmeRF system is a metal-responsive efflux mechanism acting as a key element for metal homeostasis in R. leguminosarum under free-living and symbiotic conditions. The presence of similar dmeRF gene clusters in other Rhizobiaceae suggests that the dmeRF system is a conserved mechanism for metal tolerance in legume endosymbiotic bacteria
    • 

    corecore