Vortices and Impurities

We describe the BPS dynamics of vortices in the presence of impurities. We argue that a moduli space of solitons survives the addition of both electric and magnetic impurities. However, dynamics on the moduli space is altered. In the case of electric impurities, the metric remains unchanged but the dynamics is accompanied by a connection term, acting as an effective magnetic field over the moduli space. We give an expression for this connection and compute the vortex-impurity bound states in simple cases. In contrast, magnetic impurities distort the metric on the moduli space. We show that magnetic impurities can be viewed as vortices associated to a second, frozen, gauge group. We provide a D-brane description of the dynamics of vortices in product gauge groups and show how one can take the limit such that a subset of the vortices freeze.Comment: 19 pages, 2 figures. v2: version to appear in JHE

Naturalizing ethics

In this essay we provide (1) an argument for why ethics should be naturalized, (2) an analysis of why it is not yet naturalized, (3) a defense of ethical naturalism against two fallacies—Hume’s and Moore’s—that ethical naturalism allegedly commits, and (4) a proposal that normative ethics is best conceived as part of human ecology committed to pluralistic relativism. We explain why naturalizing ethics both entails relativism and also constrains it, and why nihilism about value is not an especially worrisome for ethical naturalists. The substantive view we put forth constitutes the essence of Duke Naturalism

Naturalizing ethics

In this essay we provide (1) an argument for why ethics should be naturalized, (2) an analysis of why it is not yet naturalized, (3) a defense of ethical naturalism against two fallacies—Hume’s and Moore’s—that ethical naturalism allegedly commits, and (4) a proposal that normative ethics is best conceived as part of human ecology committed to pluralistic relativism. We explain why naturalizing ethics both entails relativism and also constrains it, and why nihilism about value is not an especially worrisome for ethical naturalists. The substantive view we put forth constitutes the essence of Duke Naturalism. (NOTE: This is a slightly modified reprint of Flangan et al 2007 of the same title.

Salivary biomarker development using genomic, proteomic and metabolomic approaches.

The use of saliva as a diagnostic sample provides a non-invasive, cost-efficient method of sample collection for disease screening without the need for highly trained professionals. Saliva collection is far more practical and safe compared with invasive methods of sample collection, because of the infection risk from contaminated needles during, for example, blood sampling. Furthermore, the use of saliva could increase the availability of accurate diagnostics for remote and impoverished regions. However, the development of salivary diagnostics has required technical innovation to allow stabilization and detection of analytes in the complex molecular mixture that is saliva. The recent development of cost-effective room temperature analyte stabilization methods, nucleic acid pre-amplification techniques and direct saliva transcriptomic analysis have allowed accurate detection and quantification of transcripts found in saliva. Novel protein stabilization methods have also facilitated improved proteomic analyses. Although candidate biomarkers have been discovered using epigenetic, transcriptomic, proteomic and metabolomic approaches, transcriptomic analyses have so far achieved the most progress in terms of sensitivity and specificity, and progress towards clinical implementation. Here, we review recent developments in salivary diagnostics that have been accomplished using genomic, transcriptomic, proteomic and metabolomic approaches

What is the nature of morality? A response to Casebeer, Railton and Ruse

A response to comments by William Casebeer, Peter Railton, and Michael Ruse on "Naturalizing Ethics" (2007)