Christopher Hill

Mesenchymal stem cells are capable of regenerative and immunomodulatory functions in cell-based therapies in a variety of human diseases and injuries; however, their therapeutic efficacy and potential side effects remain major obstacles in clinical applications. We report here a 3D spheroid culture approach to optimize stem cell properties and therapeutic effects of human gingiva-derived mesenchymal stem cells in mitigation of experimental oral mucositis. Under growth condition of ultra-low attachment, GMSCs spontaneously aggregated into 3D spheroids and exhibited distinct early stem cell phenotype characterized by elevated expression Stro-1 and CXC chemokine receptor 4 as well as OCT-4 and Nanog, 2 important transcriptional factors relevant to stem cell properties, and decreased expression of MSC-associated markers, including CD29, CD90, and CD105. Functionally, spheroid GMSCs are capable of enhanced multipotency and augmented secretion of several chemokines and cytokines relevant to cell migration, survival, and angiogenesis. More importantly, spheroid GMSCs expressed increased levels of reactive oxygen species, hypoxia-inducible factor -1 and -2α, and manganese superoxide dismutase, which correlated with improved resistance to oxidative stress-induced apoptosis. Using an in vivo murine model of chemotherapy-induced oral mucositis, we demonstrated that spheroid-derived GMSCs possessed better therapeutic efficacy than their adherent cells in reversing body weight loss and promoting the regeneration of disrupted epithelial lining of the mucositic tongues. These findings suggest that 3D spheroid culture allows early stemness preservation and potentially precondition GMSCs for enhanced mitigation of oral mucositis. © 2012 Mary Ann Liebert, Inc.

Identity theory The doctrine that mental states are identical with physical states was defended in antiquity by Lucretius and in the early modern era by Hobbes. It achieved considerable prominence in the 1950s as a result of the writings of Herbert Feigl, U. T. Place, and J. J. C. Smart. (See, e.g., Smart (1959). These authors developed reasonably precise formulations of the doctrine, clarified the grounds for embracing it, and responded persuasively to a range of objections. More recently it has been defended systematically by Hill (1991) and Papineau (2002). Other contemporary advocates include Loar (1990), McLaughlin (2004), and Polger (2005). The doctrine also figures explicitly or implicitly in the writings of dualists, who are of course concerned to oppose it. Thus, for example, it plays an important role in Kripke’s influential defense of dualism (Kripke 1980)

In concert with his attack on analyticity, Quine argued that no proposition is immune to empirical revision. In principle, at least, it is possible even for the laws of logic and mathematics to be called into question by empirical evidence. This chapter responds to this view, urging that it is possible to explain immunity to revision in terms of relativity clear notions, and arguing that the resulting conception of immunity applies to a fairly broad range of propositions, including abbreviative definitions, the laws of classical logic, and the laws of mathematics.

In this paper I celebrate the virtues of Hurlburt and Schwitzgebel's path-breaking book on introspection, but I also exp-ress dissatisfaction with a few of its recurring themes. The main body of the paper consists of seven theses about the way in which the study of introspection should be conducted. Thus, to a large extent, the paper is a methodological proposal, though it also makes a number of concrete claims about the nature of introspection, and about the epistemological status of its deliverances. The methodology I endorse is quite different than the one that Hurlburt advocates, but even so, it is compatible with assigning a large role to Descriptive Experience Sampling. Equally, while I am no fan of Schwitzgebel's radical scepti-cism about introspection, he and I are of like mind on a number of spe-cific epistemological issues, and we share the sense that it would be useful to draw on other areas of cognitive science in extending Descriptive Experience Sampling and refining it

John Heil’s new book ranges over many of the major topics in metaphysics, including substance, properties, causation, space, time, parts and wholes, modality, essence, agency, and consciousness. It has interesting things to say about all of the issues it discusses, but there are three topics that are especially prominent in the book, and which help to organize the discussion. These all flow from the differences between our everyday, commonsense understanding of reality and the representations that are offered by science.

I argue for three claims. (1) The phenomenology of visual experience is exhausted by awareness of appearance properties (i.e., certain constantly changing characteristics of external objects that are relational and viewpoint‐dependent). (2) Cognition differs from perception in that it has a purely discursive or linguistic dimension, whereas perception is pervasively analog and iconic; but this does not determine a border between the two domains, for cognition also has a massive iconic dimension. And (3) certain raging debates in teleosemantics can be resolved by acknowledging that perceptual representations in more primitive organisms tend to have dual contents (e.g., both small, moving black object, and food).