Exact non-abelian duality

We investigate non-abelian gaugings of WZNW models. When the gauged group is semisimple we are able to present exact formulae for the dual conformal field theory, for all values of the level $k$. The results are then applied to non-abelian target space duality in string theory, showing that the standard formulae are quantum mechanically well defined in the low energy limit if the gauged group is semisimple.Comment: 17 pages uuencoded Z-compressed late

Functional reconstruction of the glenoid fossa utilizing a pedicled temporal osteomuscular flap

Current techniques in management of end stage pathology of the temporomandibular joint (TMJ) include the use of alloplastic joint reconstruction. A polyethylene glenoid fossa prosthesis is a necessity of this treatment as it provides a stable platform for function of the metal alloy condylar head. Additionally, the fossa prosthesis limits superior and posterior movement of the reconstructed joint which prevents complications such as migration of the condylar prosthesis into the middle cranial fossa and ear, ankylosis, and pain. When a pathologic process affects the glenoid fossa alone, alloplastic joint reconstruction becomes a less desirable treatment option. Lack of osseous structure along the temporal bone and zygomatic arch can impact the surgeon\u27s ability to fixate a glenoid fossa prosthesis. Additionally, resection of an uninvolved condylar head in situations where there is no advanced pathology would provide a functional solution, but may be overly aggressive and potentially unnecessary. The following is our experience with utilizing a pedicled temporal osteomuscular flap to reconstruct an acquired defect of the glenoid fossa in a 42-year-old male with a diffuse-type tenosynovial giant cell tumor. In this case the mandibular condyle was not affected by the pathology

Under the influence of genetics: how transdisciplinarity leads us to rethink social pathways to illness

This article describes both sociological and genetic theories of illness causation and derives propositions expected under each and under a transdisciplinary theoretical frame. The authors draw propositions from three theories -- fundamental causes, social stress processes, and social safety net theories -- and tailor hypotheses to the case of alcohol dependence. Analyses of a later wave of the Collaborative Study on the Genetics of Alcoholism reveal a complex interplay of the GABRA2 gene with social structural factors to produce cases meeting DSM/ICD diagnoses. Only modest evidence suggests that genetic influence works through social conditions and experiences. Further, women are largely unaffected in their risk for alcohol dependence by allele status at this candidate gene; family support attenuates genetic influence; and childhood deprivation exacerbates genetic predispositions. These findings highlight the essential intradisciplinary tension in the role of proximal and distal influences in social processes and point to the promise of focusing directly on dynamic, networked sequences that produce different pathways to health and illness

A low-cost electrical impedance analyser for interrogating self-sensing cement repairs

In this paper, we showcase initial results from a bespoke, low-cost interrogator for complex impedance measurements of our robotically deployed self-sensing cement (geopolymer) technology for concrete monitoring and maintenance. Our low-cost (£30, 40USD)interrogation system is benchmarked against the performance of a£12k(16k USD) commercially available lab-spec electrical impedance analyser. Results show the low-cost interrogator is able to match the commercial interrogation system well-enough for the field measurement of impedance, with an impedance root mean square error (RMSE) of ±5.4 % for an ideal cell. For pure geopolymer samples, similar results are found, with an RMSE of ±5.2 %. During patch measurements, although non-linearity was witnessed, the low-cost interrogator showcased the ability to measure the impedance and impedance-frequency variations. Therefore, the first iteration of low-cost interrogator design shows promise for monitoring geopolymer self-sensing repair complex impedances in the field

3D printed cement-based repairs and strain sensors

This paper presents 3D printed strain sensors based on alkali activated cement repairs, demonstrating a fixed-cost method for remotely deploying a combined monitoring and maintenance technology for construction. Experimental protocols to quantitatively assess the compatibility of cements and 3D printing processes are defined and investigated in this paper. The strain sensing response of printed self-sensing cements is then investigated under compression and tension by monitoring changes in material electrical impedance. Gauge factors for self-sensing repairs printed onto concrete substrates were 8.6 ± 1.6 under compression, with an average adhesion strength of 0.6 MPa between printed repair and concrete substrate. Gauge factors for repairs printed onto glass fibre reinforced polymers were 38.4 ± 21.6 under tension: more variable than for concrete substrates due to incompatibilities between the repair and the polymer substrate. This proof-of-concept is a step towards monitoring and maintenance methods that are more compatible with the time and cost drivers of modern construction