8,536 research outputs found
Constitutional Talk: Exploring Institutional Scope Conditions for Effective Arguing
[From the introduction]. Arguing, understood as reason-giving, is all pervasive in international politics: Negotiating actors give reasons for their demands at almost any time, regardless of whether talks are con-ducted in public or behind closed doors. And yet, since negotiations have most often been conceived of as processes of bargaining in which actors seek to adjust their behavior through the exchange of threats and incentives, arguments have primarily been treated as rather epiphenomenal to strategic interaction. In this paper we argue that under certain circum-stances arguments affect negotiating actors’ preferences, and subsequently lead to outcomes that are not easily explained in pure bargaining terms. Arguing and bargaining as different modes of interaction, however, are not contending but rather complementing explanations. As a result, we have to ask which scope conditions are particularly conducive to enabling arguing to prevail in decentralized negotiations and, thus, to affect both process and outcome. In a structured-focused comparison of Intergovernmental Conferences (IGCs) with the European Convention we aim to unveil institutional factors that induce actors to take validity claims into account and change their preferences accordingly. At the example of negotiations on sim-plification and the single legal personality of the European Union we seek to demonstrate that the transparency of the debate in conjunction with a higher degree of uncertainty about appro-priate behavior made arguing in the Convention particularly effective
Heterogeneous accretion of Earth inferred from Mo-Ru isotope systematics
The Mo and Ru isotopic compositions of meteorites and the bulk silicate Earth (BSE) hold important clues about the provenance of Earth's building material. Prior studies have argued that non-carbonaceous (NC) and carbonaceous (CC) meteorite groups together define a Mo-Ru ‘cosmic’ correlation, and that the BSE plots on the extension of this correlation. These observations were taken as evidence that the final 10–15% of Earth's accreted material derived from a homogeneous inner disk reservoir with an enstatite chondrite-like isotopic composition. Here, using new Mo and Ru isotopic data for previously uninvestigated meteorite groups, we show that the Mo-Ru correlation only exists for NC meteorites, and that both the BSE and CC meteorites fall off this Mo-Ru correlation. These observations indicate that the final stages of Earth's accretion were heterogeneous and consisted of a mixture of NC and CC materials. The Mo-Ru isotope systematics are best accounted for by either an NC heritage of the late veneer combined with a CC heritage of the Moon-forming giant impactor, or by mixed NC-CC compositions for both components. The involvement of CC bodies in the late-stage accretionary assemblage of Earth is consistent with chemical models for core-mantle differentiation, which argue for the addition of more oxidized and volatile-rich material toward the end of Earth's formation. As such, this study resolves the inconsistencies between homogeneous accretion models based on prior interpretations of the Mo-Ru systematics of meteorites and the chemical evidence for heterogeneous accretion of Earth
Representations underlying skill in the discrete sequence production task: effect of hand used and hand position
Various studies suggest that movement sequences are initially learned predominantly in effector-independent spatial coordinates and only after extended practice in effector-dependent coordinates. The present study examined this notion for the discrete sequence production (DSP) task by manipulating the hand used and the position of the hand relative to the body. During sequence learning in Experiment 1, in which sequences were executed by reacting to key-specific cues, hand position appeared important for execution with the practiced but not with the unpracticed hand. In Experiment 2 entire sequences were executed by reacting to one cue. This produced similar results as in Experiment 1. These experiments support the notion that robustness of sequencing skill is based on several codes, one being a representation that is both effector and position dependent
Trace for the Loewner Equation with Singular Forcing
The Loewner equation describes the time development of an analytic map into
the upper half of the complex plane in the presence of a "forcing", a defined
singularity moving around the real axis. The applications of this equation use
the trace, the locus of singularities in the upper half plane. This note
discusses the structure of the trace for the case in which the forcing
function, xi(t), is proportional to (-t)^beta with beta in the interval (0,
1/2). In this case, the trace is a simple curve, gamma(t), which touches the
real axis twice. It is computed by using matched asymptotic analysis to compute
the trajectory of the Loewner evolution in the neighborhood of the singularity,
and then assuming a smooth mapping of these trajectories away from the
singularity. Near the t=0 singularity, the trace has a shape given by
[ Re(gamma(t)-gamma(0)) ]^(1-beta) ~ [ beta*Im(gamma(t)) ]^beta ~
O(xi(t))^(1-beta).
A numerical calculation of the trace provides support for the asymptotic
theory.Comment: 21 pages, 6 figures, submitted to Nonlinearit
Conceptualizing Democracy as Preparation for Teaching for Democracy
In this essay, a broad spectrum of the work of influential educational scholars was examined in order to identify crucial components of teaching for democracy. Synthesizing the literature with their experiences as middle level teachers and teacher educators, the authors determined those conceptions that would be most fruitful for moving in-service teachers to enact the more “muscular” concepts that foster civic participation and social justice. This collaboration resulted in the identification of four democratic practices as a foundation for designing a course on teaching for democracy. These included amplification of the voices of historically marginalized people, recognition that those in power must work to meet the needs of those without power, recognition of the advantages of diversity even at the potential expense of efficiency, and collaboration in order to teach for democracy
Real-time dynamics induced by quenches across the quantum critical points in gapless Fermi systems with a magnetic impurity
The energy-dependent scattering of fermions from a localized orbital at an
energy-dependent rate gives rise to
quantum critical points (QCPs) in the pseudogap single-impurity Anderson model
separating a local moment phase with an unscreened spin moment from a
strong-coupling phase which slightly deviates from the screened phase of
standard Kondo problem. Using the time-dependent numerical renormalization
group (TD-NRG) approach we show that local dynamic properties always
equilibrate towards a steady-state value even for quenches across the QCP but
with systematic deviations from the thermal equilibrium depending on the
distance to the critical coupling. Local non-equilibrium properties are
presented for interaction quenches and hybridization quenches. We augment our
numerical data by an analytical calculation that becomes exact at short times
and find excellent agreement between the numerics and the analytical theory.
For interaction quenches within the screened phase we find a universal function
for the time-dependent local double occupancy. We trace back the discrepancy
between our results and the data obtained by a time-dependent Gutzwiller
variational approach to restrictions of the wave-function ansatz in the
Gutzwiller theory: while the NRG ground states properly account for the
formation of an extended spin moment which decouples from the system in the
unscreened phase, the Gutzwiller ansatz only allows the formation of the spin
moment on the local impurity orbital
Liquid interfaces in viscous straining flows: Numerical studies of the selective withdrawal transition
This paper presents a numerical analysis of the transition from selective
withdrawal to viscous entrainment. In our model problem, an interface between
two immiscible layers of equal viscosity is deformed by an axisymmetric
withdrawal flow, which is driven by a point sink located some distance above
the interface in the upper layer. We find that steady-state hump solutions,
corresponding to selective withdrawal of liquid from the upper layer, cease to
exist above a threshold withdrawal flux, and that this transition corresponds
to a saddle-node bifurcation for the hump solutions. Numerical results on the
shape evolution of the steady-state interface are compared against previous
experimental measurements. We find good agreement where the data overlap.
However, the numerical results' larger dynamic range allows us to show that the
large increase in the curvature of the hump tip near transition is not
consistent with an approach towards a power-law cusp shape, an interpretation
previously suggested from inspection of the experimental measurements alone.
Instead the large increase in the curvature at the hump tip reflects a
logarithmic coupling between the overall height of the hump and the curvature
at the tip of the hump.Comment: submitted to JF
A Call for Self-Study in Middle Level Teacher Education
To promote dialogue and in response to calls for rigorous, large-scale, empirical studies as the standard that will move the field of middle level education forward, a collaborative of middle level teacher researchers submit three counterpoints to the appeals for consideration by the research community: 1) the power of the insights the authors’ gained from using the alternative research method of self-study; 2) the authenticity of using alternative research methods that mirror the uniqueness of a field predicated on the distinctiveness of educating diverse young adolescents; and 3) a reframing of “generalizability” from a “results” perspective to one of generalizability of the process that self-study methodology offers
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