3,409 research outputs found
Promoting decentralised and flexible budgets in England: Lessons from the past and future prospects
The UK has traditionally been viewed as a classic example of a unitary state in which central institutions dominate decision making. The recent Labour Government sought to counter this convention through devolution to Scotland, Wales, Northern Ireland and London and administrative decentralization to the English regions. This article examines New Labour’s efforts to promote sub-national policy discretion and fiscal autonomy via the Regional Funding Allocations (RFA) process. Findings are subsequently drawn upon to offer insights into the difficulties the Coalition Government is likely to face in its endeavor to decentralize functions and budgets to local authorities and communities. The paper addresses two central questions (i) Can New Labour’s attempt to promote decentralized and flexible budgets in England be viewed asevidence of a transition to a more fluid, multi-level form of governance? (ii)What lessons can be harnessed from the RFA experience in taking forward the Coalition government’s plans to promote fiscal discretion at the sub-national tier? It concludes that there are deep-rooted barriers in Whitehall that may limitthe freedoms and flexibilities pledged to local government and could undermine efforts to decentralize
The Auslander-Gorenstein property for Z-algebras
We provide a framework for part of the homological theory of Z-algebras and
their generalizations, directed towards analogues of the Auslander-Gorenstein
condition and the associated double Ext spectral sequence that are useful for
enveloping algebras of Lie algebras and related rings. As an application, we
prove the equidimensionality of the characteristic variety of an irreducible
representation of the Z-algebra, and for related representations over quantum
symplectic resolutions. In the special case of Cherednik algebras of type A,
this answers a question raised by the authors.Comment: 31 page
Differential operators and Cherednik algebras
We establish a link between two geometric approaches to the representation
theory of rational Cherednik algebras of type A: one based on a noncommutative
Proj construction, used in [GS]; the other involving quantum hamiltonian
reduction of an algebra of differential operators, used in [GG].
In the present paper, we combine these two points of view by showing that the
process of hamiltonian reduction intertwines a naturally defined geometric
twist functor on D-modules with the shift functor for the Cherednik algebra.
That enables us to give a direct and relatively short proof of the key result,
[GS, Theorem 1.4] without recourse to Haiman's deep results on the n! theorem.
We also show that the characteristic cycles defined independently in these two
approaches are equal, thereby confirming a conjecture from [GG].Comment: 37 p
The Order of Phase Transitions in Barrier Crossing
A spatially extended classical system with metastable states subject to weak
spatiotemporal noise can exhibit a transition in its activation behavior when
one or more external parameters are varied. Depending on the potential, the
transition can be first or second-order, but there exists no systematic theory
of the relation between the order of the transition and the shape of the
potential barrier. In this paper, we address that question in detail for a
general class of systems whose order parameter is describable by a classical
field that can vary both in space and time, and whose zero-noise dynamics are
governed by a smooth polynomial potential. We show that a quartic potential
barrier can only have second-order transitions, confirming an earlier
conjecture [1]. We then derive, through a combination of analytical and
numerical arguments, both necessary conditions and sufficient conditions to
have a first-order vs. a second-order transition in noise-induced activation
behavior, for a large class of systems with smooth polynomial potentials of
arbitrary order. We find in particular that the order of the transition is
especially sensitive to the potential behavior near the top of the barrier.Comment: 8 pages, 6 figures with extended introduction and discussion; version
accepted for publication by Phys. Rev.
A diffusion model decomposition of orientation discrimination in children with Autism Spectrum Disorder
Children with and without ASD performed an orientation discrimination task, in which the difficulty of the discrimination was equated across individuals. Behavioural results showed that subjects with ASD were slower in making a decision. A computational decomposition of data was performed and modelled parameters indicated that: (i) participants with ASD adopted a more conservative response criterion and (ii) motor response did not differ between groups. Our results confirm that differences in reaction times (RTs) and/or accuracy between participants with and without ASD in orientation discrimination may be related to differences in response conservativeness rather than in stimulus discriminability, in line with data previously reported from adults (Pirrone, Dickinson, Gomez, Stafford & Milne, 2017). This result has important implications for studies that have claimed impairments/enhancements in ASD on the basis of differences in RTs and/or accuracy alone
Non-trivial stably free modules over crossed products
We consider the class of crossed products of noetherian domains with
universal enveloping algebras of Lie algebras. For algebras from this class we
give a sufficient condition for the existence of projective non-free modules.
This class includes Weyl algebras and universal envelopings of Lie algebras,
for which this question, known as noncommutative Serre's problem, was
extensively studied before. It turns out that the method of lifting of
non-trivial stably free modules from simple Ore extensions can be applied to
crossed products after an appropriate choice of filtration. The motivating
examples of crossed products are provided by the class of RIT algebras,
originating in non-equilibrium physics.Comment: 13 page
Stability of Metal Nanowires at Ultrahigh Current Densities
We develop a generalized grand canonical potential for the ballistic
nonequilibrium electron distribution in a metal nanowire with a finite applied
bias voltage. Coulomb interactions are treated in the self-consistent Hartree
approximation, in order to ensure gauge invariance. Using this formalism, we
investigate the stability and cohesive properties of metallic nanocylinders at
ultrahigh current densities. A linear stability analysis shows that metal
nanowires with certain {\em magic conductance values} can support current
densities up to 10^11 A/cm^2, which would vaporize a macroscopic piece of
metal. This finding is consistent with experimental studies of gold nanowires.
Interestingly, our analysis also reveals the existence of reentrant stability
zones--geometries that are stable only under an applied bias.Comment: 12 pages, 6 figures, version published in PR
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Distinguishing personal belief from scientific knowledge for the betterment of killer whale welfare – a commentary
We contest publication of Marino et al. regarding captive killer whale (Orcinus orca) welfare because of misrepresentations of available data and the use of citations that do not support assertions. Marino et al. misrepresent stress response concepts and erroneously cite studies, which appear to support Marino et al.’s philosophical beliefs regarding the cetacean hypothalamic–pituitary–adrenal axis. To be clear, these misrepresentations are not differences of scientific opinion, as the authors’ conclusions lack any scientific basis. More extensive review of Marino et al.’s citations reveal a dearth of empirical evidence to support their assertions. Further, Marino et al.’s approach to animal welfare is not consistent with conventional veterinary approaches to animal welfare, including their apparent opposition to use of preventative and therapeutic veterinary interventions. While Marino et al. argue that killer whales’ cognitive and spatial needs preclude management of this species under human care, misrepresentation of the citations used to support this opinion invalidates their arguments. Misleading interpretations of data relative to killer whales’ cognitive and emotional needs and specious and unsubstantiated comparisons with states experienced by humans with posttraumatic stress disorder and other conditions, represent a number of strategies used to misrepresent knowledge regarding killer whale welfare. These misrepresentations and fallacies are inconsistent with scientific ethical standards for credible, peer-reviewed journals (ICMJE, 2018), and are barriers to rigorous discourse and identification of strategies for optimizing killer whale welfare. Assertions in the paper amount to nothing more than a compilation of conclusory, philosophical statements. We would also like to mention that manuscripts such as Marino et al.’s do great damage to the fields of comparative psychology and to behavioral science as a whole
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