1,788 research outputs found
Differences in localization of P2X7 during epithelial wound healing in pre-type II diabetic models
Corneal injury, accompanied by improper wound repair, is the 4th highest cause of preventable blindness according to the World Health Organization. The cornea, which is the most densely innervated structure in the human body, serves to protect the delicate internal environment of the eye from damage. The integrity of this intricate nerve structure is critical in our ability to sense even the slightest insult to the corneal surface, with reduced sensitivity leading to increased susceptibility to trauma. In diabetes, decreased corneal sensitivity secondary to diabetic peripheral neuropathy can lead to increased corneal abrasion, ulceration, and even blindness. The P2X7 purinoreceptor is an ion channel that is expressed by the epithelium along with the intra-epithelial nerves and stromal nerves. The goal of our study was to use a type 2 diabetic mouse model (DIO) to characterize the changes in P2X7 localization and potentially correlate our results with changes in trafficking and sensory nerve loss. We hypothesized that the P2X7 receptor acts to sense changes at the leading edge and this fine tuned regulation is altered during the diabetic disease state. Further understanding of the corneal changes that occur in diabetes can help us better monitor progression of diabetic complications as well as develop new therapeutics for the treatment of diabetic corneal dysfunction
The norm of assertion: Empirical data
Assertions are speech acts by means of which we express beliefs. As such they are at the heart of our linguistic and social practices. Recent research has focused extensively on the question whether the speech act of assertion is governed by norms, and if so, under what conditions it is acceptable to make an assertion. Standard theories propose, for instance, that one should only assert that p if one knows that p (the knowledge account), or that one should only assert that p if p is true (the truth account). In a series of four experiments, this question is addressed empirically. Contrary to previous findings, knowledge turns out to be a poor predictor of assertability, and the norm of assertion is not factive either. The studies here presented provide empirical evidence in favour of the view that a speaker is warranted to assert that p only if her belief that p is justified
Mens rea ascription, expertise and outcome effects: Professional judges surveyed
A coherent practice of mens rea (âguilty mindâ) ascription in criminal law presupposes a concept of mens rea which is insensitive to the moral valence of an actionâs outcome. For instance, an assessment of whether an agent harmed another person intentionally should be unaffected by the severity of harm done. Ascriptions of intentionality made by laypeople, however, are subject to a strong outcome bias. As demonstrated by the Knobe effect, a knowingly incurred negative side effect is standardly judged intentional, whereas a positive side effect is not. We report the first empirical investigation into intentionality ascriptions made by professional judges, which finds (i) that professionals are sensitive to the moral valence of outcome type, and (ii) that the worse the outcome, the higher the propensity to ascribe intentionality. The data shows the intentionality ascriptions of professional judges to be inconsistent with the concept of mens rea supposedly at the foundation of criminal law
Nucleation of reaction-diffusion waves on curved surfaces
We study reaction-diffusion waves on curved two-dimensional surfaces, and
determine the influence of curvature upon the nucleation and propagation of
spatially localized waves in an excitable medium modelled by the generic
FitzHugh-Nagumo model. We show that the stability of propagating wave segments
depends crucially on the curvature of the surface. As they propagate, they may
shrink to the uniform steady state, or expand, depending on whether they are
smaller or larger, respectively, than a critical nucleus. This critical nucleus
for wave propagation is modified by the curvature acting like an effective
space-dependent local spatial coupling, similar to diffusion, thus extending
the regime of propagating excitation waves beyond the excitation threshold of
flat surfaces. In particular, a negative gradient of Gaussian curvature
, as on the outside of a torus surface (positive ), when the
wave segment symmetrically extends into the inside (negative ), allows
for stable propagation of localized wave segments remaining unchanged in size
and shape, or oscillating periodically in size
The Content-Dependence of Imaginative Resistance
An observation of Humeâs has received a lot of attention over the last decade and a half: Although we can standardly imagine the most implausible scenarios, we encounter resistance when imagining propositions at odds with established moral (or perhaps more generally evaluative) convictions. The literature is ripe with âsolutionsâ to this so-called âPuzzle of Imaginative Resistanceâ. Few, however, question the plausibility of the empirical assumption at the heart of the puzzle. In this paper, we explore empirically whether the difficulty we witness in imagining certain propositions is indeed due to claim type (evaluative v. non-evaluative) or whether it is much rather driven by mundane features of content. Our findings suggest that claim type plays but a marginal role, and that there might hence not be much of a âpuzzleâ to be solved
Analyzing critical propagation in a reaction-diffusion-advection model using unstable slow waves
The effect of advection on the critical minimal speed of traveling waves is
studied. Previous theoretical studies estimated the effect on the velocity of
stable fast waves and predicted the existence of a critical advection strength
below which propagating waves are not supported anymore. In this paper, the
critical advection strength is calculated taking into account the unstable slow
wave solution. Thereby, theoretical results predict, that advection can induce
stable wave propagation in the non-excitable parameter regime, if the advection
strength exceeds a critical value. In addition, an analytical expression for
the advection-velocity relation of the unstable slow wave is derived.
Predictions are confirmed numerically in a two-variable reaction-diffusion
model.Comment: 11 pages, 8 figure
Incentives for nature conservation in urban landscapes
The aim of this article is to contribute to the development of ecological-economic incentives in conservation policy. Our approach uses strategies for establishing habitat networks as an example to develop spatially-oriented incentives in urban landscapes. The incentives should ideally consider aspects both of ecological effectiveness and economic efficiency. Our understanding of ecological-economic incentives reaches beyond this stage: not only must economic incentives in environmental policy be based on ecological knowledge, but also, they have to consider social aspects of implementation and acceptance. The ecological analysis of strategies for species protection in urban landscapes leads to management recommendations as a basis for the specification of environmental policy goals. Based on ecological knowledge, which shows where to invest scarce resources, the economic perspective aims at analysing and evaluating environmental policy instruments for their suitability and efficiency. The ecological and economic research is to be combined with a sociological approach, which investigates the choice and application of environmental policy measures as a system of social action. The analysis of problems of implementation and acceptance will be used to support the introduction of new instruments or to improve existing incentive systems related to nature conservation in urban landscapes. For this purpose, a survey was carried out on the use of environmental policy instruments (regulation, planning, economic incentives, communication, information) in German cities in 1997. Furthermore, two existing economic instruments in German nature protection policy are analysed in detail: the compensation charge as part of the impact regulation and incentive programmes on the level of the German federal states that offer financial incentive measures for nature protection. --
Concepts and Actors in Organic Livestock Husbandry in Bolivia
Traditional smallholder livestock production is expected to correspond widely with principles of organic livestock farming. Though, the real magnitude of livestock under organic and alike management is unknown. From stakeholder analysis and structured interviews with key persons in Bolivia it is deduced that similarities are widely given, whereas it is questioned whether a formal individual certification approach for livestock products will match the farmer interests and consumer demands
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