2,398 research outputs found
Giving voters what they want? Party orientation perceptions and preferences in the British electorate
Some of the most important propositions in the political marketing literature hinge on assumptions about the electorate. In particular, voters are presumed to react in different ways to different orientations or postures. Yet there are theoretical reasons for questioning some of these assumptions, and certainly they have seldom been empirically tested. Here, we focus on one prominent example of political marketing research: Lees-Marshment’s orientations’ model. We investigate how the public reacts to product and market orientation, whether they see a trade-off between the two (a point in dispute among political marketing scholars), and whether partisans differ from non-partisan voters by being more inclined to value product over market orientation. Evidence from two mass sample surveys of the British public (both conducted online by YouGov) demonstrates important heterogeneity within the electorate, casts doubt on the core assumptions underlying some political marketing arguments and raises broader questions about what voters are looking for in a party
Cognitive architectures as Lakatosian research programmes: two case studies
Cognitive architectures - task-general theories of the structure and function of the complete cognitive system - are sometimes argued to be more akin to frameworks or belief systems than scientific theories. The argument stems from the apparent non-falsifiability of existing cognitive architectures. Newell was aware of this criticism and argued that architectures should be viewed not as theories subject to Popperian falsification, but rather as Lakatosian research programs based on cumulative growth. Newell's argument is undermined because he failed to demonstrate that the development of Soar, his own candidate architecture, adhered to Lakatosian principles. This paper presents detailed case studies of the development of two cognitive architectures, Soar and ACT-R, from a Lakatosian perspective. It is demonstrated that both are broadly Lakatosian, but that in both cases there have been theoretical progressions that, according to Lakatosian criteria, are pseudo-scientific. Thus, Newell's defense of Soar as a scientific rather than pseudo-scientific theory is not supported in practice. The ACT series of architectures has fewer pseudo-scientific progressions than Soar, but it too is vulnerable to accusations of pseudo-science. From this analysis, it is argued that successive versions of theories of the human cognitive architecture must explicitly address five questions to maintain scientific credibility
Black Holes in Modified Gravity (MOG)
The field equations for Scalar-Tensor-Vector-Gravity (STVG) or modified
gravity (MOG) have a static, spherically symmetric black hole solution
determined by the mass with two horizons. The strength of the gravitational
constant is where is a parameter. A regular
singularity-free MOG solution is derived using a nonlinear field dynamics for
the repulsive gravitational field component and a reasonable physical
energy-momentum tensor. The Kruskal-Szekeres completion of the MOG black hole
solution is obtained. The Kerr-MOG black hole solution is determined by the
mass , the parameter and the spin angular momentum . The
equations of motion and the stability condition of a test particle orbiting the
MOG black hole are derived, and the radius of the black hole photosphere and
the shadows cast by the Schwarzschild-MOG and Kerr-MOG black holes are
calculated. A traversable wormhole solution is constructed with a throat
stabilized by the repulsive component of the gravitational field.Comment: 14 pages, 3 figures. Upgraded version of paper to match published
version in European Physics Journal
Generalized Painleve-Gullstrand descriptions of Kerr-Newman black holes
Generalized Painleve-Gullstrand metrics are explicitly constructed for the
Kerr-Newman family of charged rotating black holes. These descriptions are free
of all coordinate singularities; moreover, unlike the Doran and other proposed
metrics, an extra tunable function is introduced to ensure all variables in the
metrics remain real for all values of the mass M, charge Q, angular momentum
aM, and cosmological constant \Lambda > - 3/(a^2). To describe fermions in
Kerr-Newman spacetimes, the stronger requirement of non-singular vierbein
one-forms at the horizon(s) is imposed and coordinate singularities are
eliminated by local Lorentz boosts. Other known vierbein fields of Kerr-Newman
black holes are analysed and discussed; and it is revealed that some of these
descriptions are actually not related by physical Lorentz transformations to
the original Kerr-Newman expression in Boyer-Lindquist coordinates - which is
the reason complex components appear (for certain ranges of the radial
coordinate) in these metrics. As an application of our constructions the
correct effective Hawking temperature for Kerr black holes is derived with the
method of Parikh and Wilczek.Comment: 5 pages; extended to include application to derivation of Hawking
radiation for Kerr black holes with Parikh-Wilczek metho
Some remarks on a new exotic spacetime for time travel by free fall
This work is essentially a review of a new spacetime model with closed causal
curves, recently presented in another paper (Class. Quantum Grav.
\textbf{35}(16) (2018), 165003). The spacetime at issue is topologically
trivial, free of curvature singularities, and even time and space orientable.
Besides summarizing previous results on causal geodesics, tidal accelerations
and violations of the energy conditions, here redshift/blueshift effects and
the Hawking-Ellis classification of the stress-energy tensor are examined.Comment: 17 pages, 9 figures. Submitted as a contribution to the proceedings
of "DOMOSCHOOL - International Alpine School of Mathematics and Physics,
Domodossola 2018". Possible text overlaps with my previous work
arXiv:1803.08214, of which this is essentially a review. Additional results
concerning redshift/blueshift effects and the classification of the
stress-energy tensor are presented her
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What are the psychosocial outcomes of treatment for thyroid eye disease? A systematic review
Background: Thyroid eye disease (TED) causes a number of esthetic and visual problems and its treatment requires close clinical assessment, often for several years. There is evidence to suggest that clinical factors are poor indicators of patient-reported outcomes after treatments that aim to improve appearance, vision, or both. Psychosocial factors can impact on both adjustment to living with TED and also patients’ perceptions of their improvements after treatment. There has been growing recognition that it is essential to evaluate treatment efficacy in terms of psychosocial outcomes but, to date, there has been no review that has systematically evaluated psychosocial outcomes following a variety of treatments for TED.
Summary: Fifteen studies were included in the review and 6 were randomized controlled trials (RCTs). The studies varied greatly in methodological rigor; whilst major treatments such as surgery do improve quality of life outcomes, other non-invasive treatments such as intravenous steroids can have a similar impact and show long-term benefits. Only 3 studies reviewed orbital decompressive surgery which showed better psychosocial outcomes than other types of surgery.
Conclusions: The effect of some treatments remains unclear due to poor methodology and poor reporting of results. Clinicians need to be aware when planning rehabilitative treatments such as surgery the influence of psychosocial factors on quality of life outcomes and the lack of a relationship with clinical factors such as disease severity
Polarization of coalitions in an agent-based model of political discourse
Political discourse is the verbal interaction between political actors in a policy domain. This article explains the formation of polarized advocacy or discourse coalitions in this complex phenomenon by presenting a dynamic, stochastic, and discrete agent-based model based on graph theory and local optimization. In a series of thought experiments, actors compute their utility of contributing a specific statement to the discourse by following ideological criteria, preferential attachment, agenda-setting strategies, governmental coherence, or other mechanisms. The evolving macro-level discourse is represented as a dynamic network and evaluated against arguments from the literature on the policy process. A simple combination of four theoretical mechanisms is already able to produce artificial policy debates with theoretically plausible properties. Any sufficiently realistic configuration must entail innovative and path-dependent elements as well as a blend of exogenous preferences and endogenous opinion formation mechanisms
Atypical onset of diabetes in a teenage girl: a case report
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Transport phenomena in electrolyte solutions: Non-equilibrium thermodynamics and statistical mechanics
The theory of transport phenomena in multicomponent electrolyte solutions is
presented here through the integration of continuum mechanics,
electromagnetism, and non-equilibrium thermodynamics. The governing equations
of irreversible thermodynamics, including balance laws, Maxwell's equations,
internal entropy production, and linear laws relating the thermodynamic forces
and fluxes, are derived. Green-Kubo relations for the transport coefficients
connecting electrochemical potential gradients and diffusive fluxes are
obtained in terms of the flux-flux time correlations. The relationship between
the derived transport coefficients and those of the Stefan-Maxwell and
infinitely dilute frameworks are presented, and the connection between the
transport matrix and experimentally measurable quantities is described. To
exemplify application of the derived Green-Kubo relations in molecular
simulations, the matrix of transport coefficients for lithium and chloride ions
in dimethyl sulfoxide is computed using classical molecular dynamics and
compared with experimental measurements.Comment: fixed typos, added references, addressed comment
Separability of Black Holes in String Theory
We analyze the origin of separability for rotating black holes in string
theory, considering both massless and massive geodesic equations as well as the
corresponding wave equations. We construct a conformal Killing-Stackel tensor
for a general class of black holes with four independent charges, then identify
two-charge configurations where enhancement to an exact Killing-Stackel tensor
is possible. We show that further enhancement to a conserved Killing-Yano
tensor is possible only for the special case of Kerr-Newman black holes. We
construct natural null congruences for all these black holes and use the
results to show that only the Kerr-Newman black holes are algebraically special
in the sense of Petrov. Modifying the asymptotic behavior by the subtraction
procedure that induces an exact SL(2)^2 also preserves only the conformal
Killing-Stackel tensor. Similarly, we find that a rotating Kaluza-Klein black
hole possesses a conformal Killing-Stackel tensor but has no further
enhancements.Comment: 27 page
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