Pulse confinement in optical fibers with random dispersion

Short range correlated uniform noise in the dispersion coefficient, inherent in many types of optical fibers, broadens and eventually destroys all initially ultra-short pulses. However, under the constraint that the integral of the random component of the dispersion coefficient is set to zero, or pinned, periodically or quasi-periodically along the fiber, the nature of the pulse propagation changes dramatically. For the case that randomness is added to constant positive dispersion, the pinning restriction significantly reduces pulse broadening. If the randomness is added to piecewise constant periodic dispersion, the pinning may even provide probability distributions of pulse parameters that are numerically indistinguishable from the statistically steady case. The pinning method can be used to both manufacture better fibers and upgrade existing fiber links.Comment: 4 pages, 2 figure

Exploring Hospital Policy Makers’ Understandings of Forensic Inpatient Sexualities

Background: UK professionals’ understandings of their roles with regards to service users’ sexualities is an under-explored area in clinical research and training, particularly within forensic mental health pathways where they may be exclusively conceptualised in terms of their potential negative underpinnings and outcomes. Secure services typically have no policies governing or promoting sexual expression, and tend to prohibit sexual intimacy. However, recent developments in national guidance and findings emerging from UK-based and international research raise questions as to this approach’s utility in providing rehabilitative care. To date, no research has investigated forensic hospital policy-makers’ sense-making practices around detainees’ sexualities. Aims: This study aims to examine hospital policy-makers’ understandings of forensic detainees’ sexualities, and how these relate to their experiences of practice and their vision of a policy governing sexual expression in hospital. The research is one part of a broader project that has previously explored detainees’ and professionals’ understandings of how sexualities operate within forensic institutions, and aims to support the development of policy and training materials. Methods: The present research draws upon a social constructionist epistemology, using a qualitative, thematic decomposition approach to examine the socially-sedimented discourses at play within the forensic hospital. Ten policymakers were recruited the largest provider of forensic inpatient services in the UK, and participated in semi-structured interviews. Findings: Three themes were identified: 1) Risk and Uncertainty, 2) Artificial Realities, 3) Detained Bodies. The implications of each of these are discussed in terms of their sub-themes. Conclusion: Despite being broadly consistent with policy-makers’ understandings of holistic, rehabilitative practice, the prospect of lessening restrictions on detainees’ sexual expression presents a number of challenges and concerns. ‘Traditional’ institutional and populist discourses concerning forensic professionals’ responsibility to prevent harm tended to supersede those supporting positive risk-taking and human rights-based approaches. The propensity for UK tabloid media to depict forensic detainees and professionals in an unfavourable light, and the accompanying potential for increased government scrutiny, was understood as a primary barrier to enacting less restrictive practices. The hospital itself was positioned as vulnerable to the predations of wider society

Advances in induction-heated plasma torch technology

Continuing research has resulted in significant advances in induction-heated plasma torch technology which extend and enhance its potential for broad range of uses in chemical processing, materials development and testing, and development of large illumination sources. Summaries of these advances are briefly described

The a-function in six dimensions

The a-function is a proposed quantity defined in even dimensions which has a monotonic behaviour along RG flows, related to the beta-functions via a gradient flow equation. We study the a-function for a general scalar theory in six dimensions, using the beta-functions up to three-loop order for both the MSbar and MOM schemes (the latter presented here for the first time at three loops).Comment: 27 pages, seven figures, uses axodraw. Minor improvements in wordin