How to find an attractive solution to the liar paradox

The general thesis of this paper is that metasemantic theories can play a central role in determining the correct solution to the liar paradox. I argue for the thesis by providing a specific example. I show how Lewis’s reference-magnetic metasemantic theory may decide between two of the most influential solutions to the liar paradox: Kripke’s minimal fixed point theory of truth and Gupta and Belnap’s revision theory of truth. In particular, I suggest that Lewis’s metasemantic theory favours Kripke’s solution to the paradox over Gupta and Belnap’s. I then sketch how other standard criteria for assessing solutions to the liar paradox, such as whether a solution faces a so-called revenge paradox, fit into this picture. While the discussion of the specific example is itself important, the underlying lesson is that we have an unused strategy for resolving one of the hardest problems in philosophy

Implicit Treatment of Underlying Comprehension Processes Improves Narrative Comprehension in Right Hemisphere Brain Damage

Language comprehension deficits in adults with focal right hemisphere brain damage (RHD) can cause considerable social handicap. To date, however, treatment for these deficits remains almost entirely untested. This abstract reports an investigation of whether Contextual Constraint Treatment (CCT) -- a novel, implicit, stimulation-facilitation treatment for language comprehension processes1,2 -- can yield generalized gains to measures of discourse comprehension in adults with RHD. The focus of CCT is motivated by two major accounts of typical RHD language comprehension problems: that they are due to coarse coding or suppression deficits. Coarse coding (CC) activates wide-ranging aspects of word meaning independent of surrounding context. In RHD, CC deficits impair processing of distant meanings/features of words (e.g., “rotten” as a feature of “apple”)3. A normal suppression (SUPP) process reduces mental activation of concepts that become less relevant to a current context. RHD SUPP impairment is indexed by prolonged processing interference from contextually-inappropriate interpretations (e.g., the “ink” meaning of the word “pen,” in the sentence “He built a pen”)4,5. CC and SUPP are partially domain-general language comprehension processes. For example, both predict aspects of discourse comprehension and are hypothesized to underpin figurative language comprehension; SUPP is important for resolving lexical and inferential ambiguities; and CC is involved in processing both literal lexical items and phrasal metaphors1,2,6. Thus, treatment that improves CC and SUPP processes may hold promise for improving a broad range of communicative outcomes. CCT is novel in aiming to facilitate comprehension processes implicitly, through contextual prestimulation. Adults with RHD who perform well on implicit assessments of language processing often have difficulty on metalinguistic assessments of the same operations2. Thus we implemented this approach to avoid confounding treatment of impaired processes with irrelevant, and potentially difficult, task demands

Culturing Pancreatic Islets in Microfluidic Flow Enhances Morphology of the Associated Endothelial Cells

Pancreatic islets are heavily vascularized in vivo with each insulin secreting beta-cell associated with at least one endothelial cell (EC). This structure is maintained immediately post-isolation; however, in culture the ECs slowly deteriorate, losing density and branched morphology. We postulate that this deterioration occurs in the absence of blood flow due to limited diffusion of media inside the tissue. To improve exchange of media inside the tissue, we created a microfluidic device to culture islets in a range of flow-rates. Culturing the islets from C57BL6 mice in this device with media flowing between 1 and 7 ml/24 hr resulted in twice the EC-density and -connected length compared to classically cultured islets. Media containing fluorescent dextran reached the center of islets in the device in a flow-rate-dependant manner consistent with improved penetration. We also observed deterioration of EC morphology using serum free media that was rescued by addition of bovine serum albumin, a known anti-apoptotic signal with limited diffusion in tissue. We further examined the effect of flow on beta-cells showing dampened glucose-stimulated Ca2+-response from cells at the periphery of the islet where fluid shear-stress is greatest. However, we observed normal two-photon NAD(P)H response and insulin secretion from the remainder of the islet. These data reveal the deterioration of islet EC-morphology is in part due to restricted diffusion of serum albumin within the tissue. These data further reveal microfluidic devices as unique platforms to optimize islet culture by introducing intercellular flow to overcome the restricted diffusion of media components

Report from IPITA-TTS opinion leaders meeting on the future of β-cell replacement

Peer reviewe

The Use of Biomaterials in Islet Transplantation

Pancreatic islet transplantation is a therapeutic option to replace destroyed β cells in autoimmune diabetes. Islets are transplanted into the liver via the portal vein; however, inflammation, the required immunosuppression, and lack of vasculature decrease early islet viability and function. Therefore, the use of accessory therapy and biomaterials to protect islets and improve islet function has definite therapeutic potential. Here we review the application of niche accessory cells and factors, as well as the use of biomaterials as carriers or capsules, for pancreatic islet transplantation

Combinatorial hydrogel library enables identification of materials that mitigate the foreign body response in primates

The foreign body response is an immune-mediated reaction that can lead to the failure of implanted medical devices and discomfort for the recipient. There is a critical need for biomaterials that overcome this key challenge in the development of medical devices. Here we use a combinatorial approach for covalent chemical modification to generate a large library of variants of one of the most widely used hydrogel biomaterials, alginate. We evaluated the materials in vivo and identified three triazole-containing analogs that substantially reduce foreign body reactions in both rodents and, for at least 6 months, in non-human primates. The distribution of the triazole modification creates a unique hydrogel surface that inhibits recognition by macrophages and fibrous deposition. In addition to the utility of the compounds reported here, our approach may enable the discovery of other materials that mitigate the foreign body response.Leona M. and Harry B. Helmsley Charitable Trust (3-SRA-2014-285-M-R)United States. National Institutes of Health (EB000244)United States. National Institutes of Health (EB000351)United States. National Institutes of Health (DE013023)United States. National Institutes of Health (CA151884)United States. National Institutes of Health (P41EB015871-27)National Cancer Institute (U.S.) (P30-CA14051

BooleSim: an interactive Boolean network simulator

BooleSim (Boolean network simulator) is an open-source in-browser tool for simulation and manipulation of Boolean networks. It was developed mainly during Google's Summer of Code 2012 and uses the biographer project for network visualization. It can be used specifically for the modeling of gene regulatory or signal transduction networks