The loss of the vocalic case markers and its consequences on surfacing complexity :postulating phonological and morphological change in the Arabic language

PhD ThesisThis thesis examines the loss of case markers in Arabic. It provides a morphophonological investigation assuming there are consequences for losing the vocalic case markers in Arabic. The main consequence is the innovation of the CVCC syllable type in Arabic. The investigation focuses on trilateral nominal that consists underlyingly of فؼًْ CVCC. In its nature, it is a diachronic-synchronic examination that was undertaken upon finding a research gap in literatures. The rationale for conducting this investigation is the evident parallel in the phonological function and the locus between the lost vocalic short markers and the modern epenthetic vowels. In addition to the morpho-syntactical function, case markers in Arabic phonologically prevent final-clusters from surfacing in CVCC underlying sequences. Since modern Arabic dialects lost the vocalic case markers it is expected that they manifest final consonantal clusters on the surface of such nominal underlying CVCC sequences. However, contrary to this expectation, an epenthesis process, which has captured a synchronic interest from phonologists, occurs in the dialects preventing the realization of CVCC syllable type. Notably, no investigation was done to examine the possibility that this epenthesis originated due to the loss of the markers even though phonologists realized that the epenthesis is provoked to prevent the final-clusters from surfacing. This study contributes towards understanding: (i) the loss of the vocalic markers, (ii) the raise of the modern epenthesis and (iii) the innovation the superheavy syllable type CVCC in Arabic. Moreover, a goal in this study is to present an account for the data within a moraic approach in a framework that characteristically captures generalizations through a ranking for constraints in different levels. The account for data in this thesis is through the tools of the Stratal version of Optimality Theory

Native aortic leaflets and permanent pacemaker implantation risk following balloon-expandable transcatheter aortic valve implantation

Objective: Permanent pacemaker implantation (PPI) risk is higher following transcatheter aortic valve implantation (TAVI) than surgical valve replacement. Native aortic leaflets are retained in patients undergoing TAVI, unlike in surgical valve replacement. Whether the retained leaflets influence PPI risk because of their proximity to the conduction system is unknown. The study sought to determine the association between infra-annular extension of native right coronary cusp/noncoronary cusp (RCC/NCC) post balloon-expandable TAVI and PPI risk. Methods: We performed a retrospective analysis of 190 patients undergoing balloon-expandable TAVI at a single center. Manifestation of infra-annular extension of RCC/NCC was considered to be present when part of leaflet extended below aortic–annular plane on post-implantation aortic-root angiography. Results: Infra-annular extension of RCC/NCC was observed in 33 patients (17.37%). PPI incidence post-TAVI was higher in patients with infra-annular extension of RCC/NCC than in those without (36.36% versus 8.92%, relative-risk: 4.08, p˂0.0001). On logistic-regression analysis, preexisting right bundle-branch block (RBBB) (odds-ratio: 12.73, 95% confidence-interval: 2.16–74.93, p = 0.005), and infra-annular extension of RCC/NCC (odds-ratio: 5.63, 95% confidence-interval: 2.17–14.58, p < 0.0001) were independently associated with PPI risk. Preexisting RBBB (φ = +0.25, p = 0.001) and infra-annular extension of RCC/NCC (φ = +0.30, p < 0.0001) showed a positive-correlation with PPI risk. Infra-annular extension of RCC/NCC was a significant predictor of PPI risk on receiver-operating-characteristic curve analysis (area under-the-curve 0.67; 95% confidence-interval: 0.54–0.79, p = 0.006). Conclusion: The retained native aortic leaflets play a significant role in PPI risk following balloon-expandable TAVI. Infra-annular extension of RCC/NCC is a novel predictor, and is associated with a four-fold higher risk of PPI