Survival mediation analysis with the death-truncated mediator: The completeness of the survival mediation parameter

In medical research, the development of mediation analysis with a survival outcome has facilitated investigation into causal mechanisms. However, studies have not discussed the death-truncation problem for mediators, the problem being that conventional mediation parameters cannot be well-defined in the presence of a truncated mediator. In the present study, we systematically defined the completeness of causal effects to uncover the gap, in conventional causal definitions, between the survival and nonsurvival settings. We proposed three approaches to redefining the natural direct and indirect effects, which are generalized forms of the conventional causal effects for survival outcomes. Furthermore, we developed three statistical methods for the binary outcome of the survival status and formulated a Cox model for survival time. We performed simulations to demonstrate that the proposed methods are unbiased and robust. We also applied the proposed method to explore the effect of hepatitis C virus infection on mortality, as mediated through hepatitis B viral load

Phase transitions in the Shastry-Sutherland lattice

Two recently developed theoretical approaches are applied to the Shastry-Sutherland lattice, varying the ratio $J'/J$ between the couplings on the square lattice and on the oblique bonds. A self-consistent perturbation, starting from either Ising or plaquette bond singlets, supports the existence of an intermediate phase between the dimer phase and the Ising phase. This existence is confirmed by the results of a renormalized excitonic method. This method, which satisfactorily reproduces the singlet triplet gap in the dimer phase, confirms the existence of a gapped phase in the interval $0.66<J'/J<0.86$Comment: Submited for publication in Phys. Rev.

A study of university teacher–student relationships from the perspective of trust: a Socratic and Confucian comparison

Confucian and Socratic schools of thought are famously noted as the foundations of Eastern and Western education systems. Confucianism emphasizes the importance of discipline and teacher’s authority; Socratic methods of teaching highly values critical thinking and the power of questioning. Confucian and Socratic schools of thought have been profoundly influencing the education systems in the Eastern and Western societies, fostering distinctive cultures and values in teaching and learning. Trust has been considered one of the most important determinants of teacher-student relationships and the efficacy of education systems. Past literature has highlighted key factors influencing trust in the teacher-student relationship in both Eastern and Western cultures. Yet more literature on trust in teacher-student relationships has a Eurocentric focus sampled from schools in Western education systems, overlooking the influence of Confucian school of thoughts and empirical data in Eastern education systems. To date, literature has neither discussed the importance of trust in both Eastern and Western education systems subscribed to Confucian and Socratic schools of thought perspectives, nor employed empirical data from higher education to compare and contrast the trust relationships in Eastern and Western education systems. This dissertation will discuss the trust relationship between teachers and students in higher education in two universities located in UK and Hong Kong, which will be indicative of Confucian and Socratic schools of thoughts in Eastern and Western education systems respectively. The first objective is to discuss the different bases of trust in Eastern and Western education systems, coupled with the influence of trust on the teacher–student relationship. Secondly, from the perspective of trust between teachers and students, this dissertation aims to explore existing trust problems in the teacher–student relationship in both Eastern and Western educational contexts. Finally, based on teacher and student trust theory, this dissertation will propose methods and counter-measures to promote a teacher–student relationship that achieves positive interaction in higher education. This dissertation discusses in depth how Confucian and Socratic schools of thoughts influence the value of trust between teachers and student in both Eastern and Western education systems, and uses empirical data to compare and contrast the determinants of trust in teacher-student relationships in the two education systems from the perspectives of both parties. Based the findings, the researcher proposes practical strategies for teachers in higher education systems, who are the potential audience of this dissertation, to establish and maintain trust in their relationships with students

A Characterization of Subspaces and Quotients of Reflexive Banach Spaces with Unconditional Bases

We prove that the dual or any quotient of a separable reflexive Banach space with the unconditional tree property has the unconditional tree property. Then we prove that a separable reflexive Banach space with the unconditional tree property embeds into a reflexive Banach space with an unconditional basis. This solves several long standing open problems. In particular, it yields that a quotient of a reflexive Banach space with an unconditional finite dimensional decomposition embeds into a reflexive Banach space with an unconditional basis