203 research outputs found
Classical logic, argument and dialectic
A well studied instantiation of Dung's abstract theory of argumentation yields argumentation-based characterisations of non-monotonic inference over possibly inconsistent sets of classical formulae. This provides for single-agent reasoning in terms of argument and counter-argument, and distributed non-monotonic reasoning in the form of dialogues between computational and/or human agents. However, features of existing formalisations of classical logic argumentation (Cl-Arg) that ensure satisfaction of rationality postulates, preclude applications of Cl-Arg that account for real-world dialectical uses of arguments by resource-bounded agents. This paper formalises dialectical classical logic argumentation that both satisfies these practical desiderata and is provably rational. In contrast to standard approaches to Cl-Arg we: 1) draw an epistemic distinction between an argument's premises accepted as true, and those assumed true for the sake of argument, so formalising the dialectical move whereby arguments\u2019 premises are shown to be inconsistent, and avoiding the foreign commitment problem that arises in dialogical applications; 2) provide an account of Cl-Arg suitable for real-world use by eschewing the need to check that an argument's premises are subset minimal and consistent, and identifying a minimal set of assumptions as to the arguments that must be constructed from a set of formulae in order to ensure that the outcome of evaluation is rational. We then illustrate our approach with a natural deduction proof theory for propositional classical logic that allows measurement of the \u2018depth\u2019 of an argument, such that the construction of depth-bounded arguments is a tractable problem, and each increase in depth naturally equates with an increase in the inferential capabilities of real-world agents. We also provide a resource-bounded argumentative characterisation of non-monotonic inference as defined by Brewka's Preferred Subtheories
Quantum Statistical Entropy and Minimal Length of 5D Ricci-flat Black String with Generalized Uncertainty Principle
In this paper, we study the quantum statistical entropy in a 5D Ricci-flat
black string solution, which contains a 4D Schwarzschild-de Sitter black hole
on the brane, by using the improved thin-layer method with the generalized
uncertainty principle. The entropy is the linear sum of the areas of the event
horizon and the cosmological horizon without any cut-off and any constraint on
the bulk's configuration rather than the usual uncertainty principle. The
system's density of state and free energy are convergent in the neighborhood of
horizon. The small-mass approximation is determined by the asymptotic behavior
of metric function near horizons. Meanwhile, we obtain the minimal length of
the position which is restrained by the surface gravities and the
thickness of layer near horizons.Comment: 11pages and this work is dedicated to the memory of Professor Hongya
Li
Black String Perturbations in RS1 Model
We present a general formalism for black string perturbations in
Randall-Sundrum 1 model (RS1). First, we derive the master equation for the
electric part of the Weyl tensor . Solving the master equation
using the gradient expansion method, we give the effective Teukolsky equation
on the brane at low energy. It is useful to estimate gravitational waves
emitted by perturbed rotating black strings. We also argue the effect of the
Gregory-Laflamme instability on the brane using our formalism.Comment: 14 pages, Based on a talk presented at ACRGR4, the 4th Australasian
Conference on General Relativity and Gravitation, Monash University,
Melbourne, January 2004. To appear in the proceedings, in General Relativity
and Gravitatio
Introducing Preference-Based Argumentation to Inconsistent Ontological Knowledge Bases
International audienceHandling inconsistency is an inherent part of decision making in traditional agri-food chains – due to the various concerns involved. In order to explain the source of inconsistency and represent the existing conflicts in the ontological knowledge base, argumentation theory can be used. However, the current state of art methodology does not allow to take into account the level of significance of the knowledge expressed by the various ontological knowledge sources. We propose to use preferences in order to model those differences between formulas and evaluate our proposal practically by implementing it within the INRA platform and showing a use case using this formalism in a bread making decision support system
Brick Walls on the Brane
The so-called ``brick-wall model'' is a semi-classical approach that has been
used to explain black hole entropy in terms of thermal matter fields. Here, we
apply the brick-wall formalism to thermal bulk fields in a Randall-Sundrum
brane world scenario. In this case, the black hole entity is really a
string-like object in the anti-de Sitter bulk, while appearing as a
Schwarzchild black hole to observers living on the brane. In spite of these
exotic circumstances, we establish that the Bekenstein-Hawking entropy law is
preserved. Although a similar calculation was recently considered in the
literature, this prior work invoked a simplifying assumption (which we avoid)
that can not be adequately justified.Comment: 18 pages, Latex; references and discussion added but conclusions
unchanged; references missing in V4 have been restore
Developmental seizures and mortality result from reducing GABAᴀ receptor α2-subunit interaction with collybistin
Fast inhibitory synaptic transmission is mediated by γ-aminobutyric acid type A receptors (GABAARs) that are enriched at functionally diverse synapses via mechanisms that remain unclear. Using isothermal titration calorimetry and complementary methods we demonstrate an exclusive low micromolar binding of collybistin to the α2-subunit of GABAARs. To explore the biological relevance of collybistin-α2-subunit selectivity, we generate mice with a mutation in the α2-subunit-collybistin binding region (Gabra2-1). The mutation results in loss of a distinct subset of inhibitory synapses and decreased amplitude of inhibitory synaptic currents. Gabra2–1 mice have a striking phenotype characterized by increased susceptibility to seizures and early mortality. Surviving Gabra2-1 mice show anxiety and elevations in electroencephalogram δ power, which are ameliorated by treatment with the α2/α3-selective positive modulator, AZD7325. Taken together, our results demonstrate an α2-subunit selective binding of collybistin, which plays a key role in patterned brain activity, particularly during development
Six-dimensional localized black holes: numerical solutions
To test the strong-gravity regime in Randall-Sundrum braneworlds, we consider
black holes bound to a brane. In a previous paper, we studied numerical
solutions of localized black holes whose horizon radii are smaller than the AdS
curvature radius. In this paper, we improve the numerical method and discuss
properties of the six dimensional (6D) localized black holes whose horizon
radii are larger than the AdS curvature radius. At a horizon temperature
, the thermodynamics of the localized black
hole undergo a transition with its character changing from a 6D Schwarzschild
black hole type to a 6D black string type. The specific heat of the localized
black holes is negative, and the entropy is greater than or nearly equal to
that of the 6D black strings with the same thermodynamic mass. The large
localized black holes show flattened horizon geometries, and the intrinsic
curvature of the horizon four-geometry becomes negative near the brane. Our
results indicate that the recovery mechanism of lower-dimensional Einstein
gravity on the brane works even in the presence of the black holes.Comment: 17 pages, 9 figures, RevTeX4, typos correcte
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