Computational Collapse of Quantum State with Application to Oblivious Transfer

Quantum 2-party cryptography differs from its classical counterpart in at least one important way: Given black-box access to a perfect commitment scheme there exists a secure 1-2 quantum oblivious transfer. This reduction proposed by Crépeau and Kilian was proved secure against any receiver by Yao, in the case where perfect commitments are used. However, quantum commitments would normally be based on computational assumptions. A natural question therefore arises: What happens to the security of the above reduction when computationally secure commitments are used instead of perfect ones? In this paper, we address the security of 1-2 QOT when computationally binding string commitments are available. In particular, we analyse the security of a primitive called Quantum Measurement Commitment when it is constructed from unconditionally concealing but computationally binding commitments. As measuring a quantum state induces an irreversible collapse, we describe a QMC as an instance of ``computational collapse of a quantum state''. In a QMC a state appears to be collapsed to a polynomial time observer who cannot extract full information about the state without breaking a computational assumption. We reduce the security of QMC to a weak binding criteria for the string commitment. We also show that secure QMCs implies QOT using a straightforward variant of the reduction above

Template directed synthesis of molecular knots

Chapter 1 introduces some important ideas involved in topology and their relationship to molecules both synthetic and naturally occurring. It includes a review of the literature related to the synthesis of topologically complex molecules with particular emphasis on template directed methods and attempts at the preparation of molecular knots. Chapter 2 then introduces my strategy for synthesising molecular knots utilising metal-ligand coordination and templating aromatic interactions. Chapter 3 outlines the preparation of some octahedral metal complexes and describes attempted direct macrocyclisation reactions to give access to molecular knots. Chapter 4 discusses some model complexes that have been used to investigate the templating aromatic interactions that form a key component of the design strategy. The influence of solvent and temperature on interactions between strongly polarised aromatic rings are reported. Chapter 5 then outlines a successful new knot synthesis. Bipyridine oligomers containing appropriate spacers spontaneously fold into a knotted structure in the presence of a metal ion. Detailed characterisation of the molecular knots obtained is provided as well as a discussion of the importance of the oligomer structure and the metal ion. Chapter 6 outlines the potential of these products as topological building blocks for the preparation of a variety of knotted structures and describes attempts to prepare a novel knotted structure which we have termed an overhand knot. Finally, the preparation in moderate yield of a molecular trefoil knot is presented. Full experimental details are given in Chapter 7

Mental health leadership and patient access to care: a public–private initiative in South Africa

BACKGROUND: Mental health leadership is a critical component of patient access to care. More specifically, the ability of mental health professionals to articulate the needs of patients, formulate strategies and engage meaningfully at the appropriate level in pursuit of resources. This is not a skill set routinely taught to mental health professionals. METHODS: A public-private mental health leadership initiative, emanating from a patient access to care programme, was developed with the aim of building leadership capacity within the South African public mental health sector. The express aim was to equip health care professionals with the requisite skills to more effectively advocate for their patients. The initiative involved participants from various sites within South Africa. Inclusion was based on the proposal of an ongoing "project", i.e. a clinician-initiated service development with a multidisciplinary focus. The projects were varied in nature but all involved identification of and a plan for addressing an aspect of the participants' daily professional work which negatively impacted on patient care due to unmet needs. Six such projects were included and involved 15 participants, comprising personnel from psychiatry, psychology, occupational therapy and nursing. Each project group was formally mentored as part of the initiative, with mentors being senior professionals with expertise in psychiatry, public health and nursing. The programme design thus provided a unique practical dimension in which skills and learnings were applied to the projects with numerous and diverse outcomes. RESULTS: Benefits were noted by participants but extended beyond the individuals to the health institutions in which they worked and the patients that they served. Participants acquired both the skills and the confidence which enabled them to sustain the changes that they themselves had initiated in their institutions. The initiative gave impetus to the inclusion of public mental health as part of the curriculum for specialist training. CONCLUSIONS: Despite the significant adverse social and economic costs of mental illness, psychiatric and related services receive a low level of priority within the health care system. Ensuring that mental health receives the recognition and the resources it deserves requires that mental health care professionals become effective advocates through mental health leadership

Existential Loneliness and end-of-life care: A Systematic Review

Contains fulltext : 88662.pdf (publisher's version ) (Closed access)Patients with a life-threatening illness can be confronted with various types of loneliness, one of which is existential loneliness (EL). Since the experience of EL is extremely disruptive, the issue of EL is relevant for the practice of end-of-life care. Still, the literature on EL has generated little discussion and empirical substantiation and has never been systematically reviewed. In order to systematically review the literature, we (1) identified the existential loneliness literature; (2) established an organising framework for the review; (3) conducted a conceptual analysis of existential loneliness; and (4) discussed its relevance for end-of-life care. We found that the EL concept is profoundly unclear. Distinguishing between three dimensions of EL-as a condition, as an experience, and as a process of inner growth-leads to some conceptual clarification. Analysis of these dimensions on the basis of their respective key notions-everpresent, feeling, defence; death, awareness, difficult communication; and inner growth, giving meaning, authenticity-further clarifies the concept. Although none of the key notions are unambiguous, they may function as a starting point for the development of care strategies on EL at the end of life.1 april 201

The RIC Recruitment & Retention Materials Toolkit – a resource for developing community-informed study materials

Clinical trials face many challenges with meeting projected enrollment and retention goals. A study’s recruitment materials and messaging convey necessary key information and therefore serve as a critical first impression with potential participants. Yet study teams often lack the resources and skills needed to develop engaging, culturally tailored, and professional-looking recruitment materials. To address this gap, the Recruitment Innovation Center recently developed a Recruitment & Retention Materials Content and Design Toolkit, which offers research teams guidance, actionable tips, resources, and customizable templates for creating trial-specific study materials. This paper seeks to describe the creation and contents of this new toolkit

Male social bonds and rank predict supporter selection in cooperative aggression in wild Barbary macaques

Cooperation in coalitions against coresident males has been shown to increase male reproductive success directly via increased mating success (levelling coalitions) or indirectly via increased dominance success (rank-changing coalitions). Two mechanisms guiding coalitionary supporter selection have been proposed. First, supporter selection may depend on the supporters available, whereby an animal chooses the highest ranking supporter present to maximize their chance of winning. Second, males may also select supporters based on the strength of the social bond they share with them. Different studies on male Barbary macaques, Macaca sylvanus, have produced support for both mechanisms but crucial assumptions and predictions remained untested. The aim of this study was to test predictions derived for both mechanisms after establishing whether Barbary macaque males formed social bonds. We observed two wild groups of macaques in Morocco (>2000. h focal animal data) and recorded the identity of males recruited to join a coalition, of all bystanders, and of the coalitionary target. We demonstrate for the first time that male Barbary macaques formed strong, equitable social bonds that were stable for 2 years. Corroborating earlier studies we found that males selected supporters by more than one criterion, namely by the strength of their social bonds to the potential ally and by their dominance rank position among potential supporters. The animals who received recruitment signals were more likely to reject the recruitment invitation the weaker their social bond to the recruiter was and if the target was higher ranking than the recruiter. In a subset in which we examined only levelling coalitions that would flatten the mating skew, males only used the mechanism that would maximize the feasibility of the coalition by more frequently selecting the highest ranked bystander. These results suggest that males flexibly apply different criteria for supporter selection depending on the context of the conflict. © 2014 The Association for the Study of Animal Behaviour