What image features guide lightness perception?

Lightness constancy is the ability to perceive black and white surface colors under a wide range of lighting conditions. This fundamental visual ability is not well understood, and current theories differ greatly on what image features are important for lightness perception. Here we measured classification images for human observers and four models of lightness perception to determine which image regions influenced lightness judgments. The models were a high-pass-filter model, an oriented difference-of-Gaussians model, an anchoring model, and an atmospheric-link-function model. Human and model observers viewed three variants of the argyle illusion (Adelson, 1993) and judged which of two test patches appeared lighter. Classification images showed that human lightness judgments were based on local, anisotropic stimulus regions that were bounded by regions of uniform lighting. The atmospheric-link-function and anchoring models predicted the lightness illusion perceived by human observers, but the high-pass-filter and oriented-difference-of-Gaussians models did not. Furthermore, all four models produced classification images that were qualitatively different from those of human observers, meaning that the model lightness judgments were guided by different image regions than human lightness judgments. These experiments provide a new test of models of lightness perception, and show that human observers' lightness computations can be highly local, as in low-level models, and nevertheless depend strongly on lighting boundaries, as suggested by midlevel models.York University Librarie

Owning Our Bodies: An Examination of Property Law and Biotechnology

This Article examines whether property law provides an appropriate forum for determining who should have rights in human biological materials. Property law is discussed and examined with reference to the complex and diverse ways that American society values human biological materials. The author argues that property law allocates goods according to market values. Because certain values, such as dignity and autonomy, cannot readily be translatable into market values, this Article concludes that property law is not sufficient to deal with the non-market aspects of human biological materials

A speculative remark on holography

Holography suggests a considerable reduction of degrees of freedom in theories with gravity. However it seems to be difficult to understand how holography could be realized in a closed re--contracting universe. In this letter we claim that a scenario which achieves that goal will eliminate all spatial degrees of freedom. This would require a different concept of quantum mechanics and would imply an intriguing increase of power for the natural laws.Comment: 14 pages, a reference adde

A Model of Regulatory Burden in Technology Diffusion: The Case of Plant-Derived Vaccines.

Plant-derived vaccines may soon displace conventional vaccines. Assuming there are no major technological barriers undermining the feasibility of this innovative technology, it is worthwhile to generate quantitative models of regulatory burden of producing and diffusing plant-derived vaccines in industrialized and developing countries. A dynamic simulation model of technology diffusion—and the data to populate it—has been generated for studying regulatory barriers in the diffusion of plant-derived vaccines. The role of regulatory burden is evaluated for a variety of scenarios in which plant-derived vaccines are produced and diffused. This model relates the innovative and conventional vaccine technologies and the effects of the impact of the uptake of the innovative technology on mortality and morbidity. This case study demonstrates how dynamic simulation models can be used to assess the long-term potential impact of novel technologies in terms of a variety of socio-economic indicators.dynamic simulation model; plant-derived vaccines; regulatory burden; technology transfer; vaccines;

Are Patents Impeding Medical Care and Innovation?

This month's debate examines whether the current patent system is crucial for stimulating health research or whether it is stifling biomedical research and impeding medical care. Background to the debate: Pharmaceutical and medical device manufacturers argue that the current patent system is crucial for stimulating research and development (R&D), leading to new products that improve medical care. The financial return on their investments that is afforded by patent protection, they claim, is an incentive toward innovation and reinvestment into further R&D. But this view has been challenged in recent years. Many commentators argue that patents are stifling biomedical research, for example by preventing researchers from accessing patented materials or methods they need for their studies. Patents have also been blamed for impeding medical care by raising prices of essential medicines, such as antiretroviral drugs, in poor countries. This debate examines whether and how patents are impeding health care and innovation

Consensus-seeking, distrust and rhetorical entrapment : the WTO decision on access to medicines

While the WTO secretariat, key delegations, several NGOs, and industry publicly present the 30 August 2003 WTO Decision as an attempt to reconcile intellectual property with access to medicines, our research shows otherwise. We draw on qualitative analyses of 54 interviews and a lexicometric analysis of press releases to show that their enthusiastic public statements contrast deeply with their internal, cynical beliefs. Most of these actors not only consider the WTO Decision to be fundamentally flawed but claim to have known this prior to its adoption. We argue that a procedural norm of consensus-seeking impeded traditional bargaining over this sensitive issue and that distrust among participants hindered truth-seeking deliberation. Caught between strategic and communicative actions, state and non-state actors found themselves trapped in their own rhetoric of reconciling intellectual property with access to medicines. They realized that the appearance of a solution, rather than a functional solution, provided the only realistic outcome to a fruitless and publicly damaging continuation of debate. From a theoretical perspective, this case study sheds a new light on the gray zone between rational choice theory and constructivism, where both discourse and strategies matter. From an empirical perspective, it illustrates the risk of seeking consensus within international regimes when the procedural norm of consensus coexists with a high level of distrust

SitesBase: a database for structure-based protein–ligand binding site comparisons

There are many components which govern the function of a protein within a cell. Here, we focus on the molecular recognition of small molecules and the prediction of common recognition by similarity between protein–ligand binding sites. SitesBase is an easily accessible database which is simple to use and holds information about structural similarities between known ligand binding sites found in the Protein Data Bank. These similarities are presented to the wider community enabling full analysis of molecular recognition and potentially protein structure–function relationships. SitesBase is accessible at