Transcatheter Aortic Valve Therapies : Insights and Solutions for Clinical Complications and Future Perspectives

This thesis contemplates current challenges of transcatheter aortic valve implantation (TAVI) and focuses on three important entities. Conduction disorders remain a frequent issue. Daily ECG analysis after the procedure may help predict the fate of acquired conduction abnormalities at an earlier stage and identify the patients who would benefit from (early) permanent pacemaker implantation. Access site management relies on suture-based techniques and has inherent limitations. Collagen plug based closure is a different mechanism, may be easier to adopt and globally reduce vascular complications. Brain injury seems omnipresent after TAVI and is difficult to reconcile with the “primum non nocere” principle. Filter based embolic protection hold promise to mitigate the effects of cerebral embolization, especially if complete protection is achieved. TAVI has now matured into a simplified procedure under local anesthesia and the performance of the latest transcatheter valve iterations approach or even supersede what can be achieved with a surgical bioprosthesis. Bicuspid aortic disease, severe aortic regurgitation and moderate aortic stenosis in heart failure are potential new indications for TAVI. Furthermore, TAVI is attractive for treatment in patients at lower risk who are younger and have a longer life expectancy

When Organizational Identification Elicits Moral Decision-Making:A Matter of the Right Climate

To advance current knowledge on ethical decision-making in organizations, we integrate two perspectives that have thus far developed independently: the organizational identification perspective and the ethical climate perspective. We illustrate the interaction between these perspectives in two studies (Study 1, N = 144, US sample; and Study 2, N = 356, UK sample), in which we presented participants with moral business dilemmas. Specifically, we found that organizational identification increased moral decision-making only when the organization’s climate was perceived to be ethical. In addition, we disentangle this effect in Study 2 from participants’ moral identity. We argue that the interactive influence of organizational identification and ethical climate, rather than the independent influence of either of these perspectives, is crucial for understanding moral decision-making in organizations

In the moral eye of the beholder:the interactive effects of leader and follower moral identity on perceptions of ethical leadership and LMX quality

Previous research indicated that leader moral identity (MI; i.e., leaders’ self-definition in terms of moral attributes) predicts to what extent followers perceive their leader as ethical (i.e., demonstrating and promoting ethical conduct in the organization). Leadership, however, is a relational process that involves leaders and followers. Building on this understanding, we hypothesized that follower and leader MI (a) interact in predicting whether followers will perceive their leaders as ethical and, as a result, (b) influence followers’ perceptions of leader–follower relationship quality. A dyadic field study (N = 101) shows that leader MI is a stronger predictor of followers’ perceptions of ethical leadership for followers who are high (vs. low) in MI. Perceptions of ethical leadership in turn predict how the quality of the relationship will be perceived. Hence, whether leader MI translates to perceptions of ethical leadership and of better relationship quality depends on the MI of followers

Controllable plasma energy bands in a 1D crystal of fractional Josephson vortices

We consider a 1D chain of fractional vortices in a long Josephson junction with alternating $\pm\kappa$ phase discontinuities. Since each vortex has its own eigenfrequency, the inter-vortex coupling results in eigenmode splitting and in the formation of an oscillatory energy band for plasma waves. The band structure can be controlled at the design time by choosing the distance between vortices or \emph{during experiment} by varying the topological charge of vortices or the bias current. Thus one can construct an artificial vortex crystal with controllable energy bands for plasmons.Comment: 4 pages, 2 Fig

Oscillatory eigenmodes and stability of one and two arbitrary fractional vortices in long Josephson 0-kappa-junctions

We investigate theoretically the eigenmodes and the stability of one and two arbitrary fractional vortices pinned at one and two $\kappa$-phase discontinuities in a long Josephson junction. In the particular case of a single $\kappa$-discontinuity, a vortex is spontaneously created and pinned at the boundary between the 0 and $\kappa$-regions. In this work we show that only two of four possible vortices are stable. A single vortex has an oscillatory eigenmode with a frequency within the plasma gap. We calculate this eigenfrequency as a function of the fractional flux carried by a vortex. For the case of two vortices, pinned at two $\kappa$-discontinuities situated at some distance $a$ from each other, splitting of the eigenfrequencies occur. We calculate this splitting numerically as a function of $a$ for different possible ground states. We also discuss the presence of a critical distance below which two antiferromagnetically ordered vortices form a strongly coupled ``vortex molecule'' that behaves as a single object and has only one eigenmode.Comment: submitted to Phys. Rev. B (