Encircled energy measurement for focusing lens based on scanning Hartmann test

The encircled energy of a focusing lens is one of the parameters directly affecting the target efficiency in high-power laser facilities. The direct measurement method of the encircled energy for the focusing lens based on the scanning Hartmann test is proposed in this paper. With the scanning Hartmann test setup, the information in the whole aperture of the focusing lens can be achieved. The encircled energy can be obtained by analyzing the spot diagram on the focal plane of the focusing lens. In experiments, the encircled energy of an aspheric focusing lens is measured using this method. The measurement result is in good agreement with that derived from measurement data by an interferometer and the difference is 7.7%. (C) 2006 Elsevier GmbH. All rights reserved.

Plasmonic graded-index planar lens based on subwavelength features in the effective index regime

We experimentally demonstrate the planar focusing of Surface Plasmon Polaritons using space variant PMMA subwavelength features on top of a metallic film. Focusing is obtained by creating an effective graded refractive index profile. © 2012 OSA.

Plasmonic graded-index planar lens based on subwavelength features in the effective index regime

We experimentally demonstrate the planar focusing of Surface Plasmon Polaritons using space variant PMMA subwavelength features on top of a metallic film. Focusing is obtained by creating an effective graded refractive index profile. © OSA 2012.

Supporting therapist engagement in evidence based practice: Developing a continuing education programme through participatory action research

Therapists find it challenging to integrate research evidence into their clinical decision-making because it may involve modifying their existing practices. Although continuing education (CE) programmes for evidence-based practice (EBP) have employed various approaches to increase individual practitioner’s knowledge and skills, these have been shown to have little impact in changing customary behaviours. To date, there has been little attempt to actively engage therapists as collaborators in developing educational processes concerning EBP. The researcher collaborated with seven clinical therapists (one occupational therapist, four physiotherapists and two speech and language therapists) enrolled in a new post-qualification Implementing Evidence in Therapy Practice (IETP) MSc module to monitor and adapt the learning programme over ten weeks. The participating therapists actively engaged in participatory action research (PAR) iterative cycles of reflecting→ planning→ acting→ observing→ reflecting with the researcher. Mixed methods were used to evaluate the IETP module and its influence on therapists’ subsequent engagement in EBP activities. Data were gathered immediately on completion of the module and five months later. Immediate post-module findings revealed four components as being important to the therapists: 1) characteristics of the learning environment; 2) acquisition of relevant EBP skills; 3) nature of the learning process; and 4) acquiring confidence. The two themes and sub-themes which emerged from individual interviews conducted five months post-module expanded on the four components already identified. Theme 1: Experiencing the learning (sub-themes: module organisation; learning is relational; improving the module); and theme 2: Enacting the learning through a new way of being (sub-themes: criticality and reflection; self agency; modelling EBP behaviours; positioning self in an EB work culture). The therapists’ perspectives had by then shifted from that of a learner to that of a clinician constructing a new sense of self as an evidence-based practitioner. Findings from this study underline the importance of the process of socially constructed knowledge and of empowering learners through collaboratively designed continuing education programmes. In the student-driven learning environment, therapists chose repetitive skill-building and authentic problem-solving activities which reflected the complexity of the environments to which they were expected to transfer their learning. These findings have implications for educators designing EBP continuing education programmes, during which students develop professional ways of being.

Post-trauma: Is evidence based practice a fantasy?

Trauma, bereavement, and loss are universal human experiences. Much has been written about the process that the bereaved go through following the loss of a loved one. Recent events such as 9/11, earthquakes in Turkey, genocides in Rwanda, community conflict in Northern Ireland, and the Asian Tsunami Disaster have drawn unprecedented public attention to the subject of traumatic bereavement. Increasingly, it is recognised that while most people are able to cope with loss generally by eventually restructuring their lives, those bereaved in traumatic circumstance often find it extremely difficult. As a consequence, a plethora of interventions have emerged, however, to-date, little is know about their actual effectiveness in helping the bereaved. With the emphasis of health and welfare professions on evidencebased practice (EBP) greater than ever and a raising awareness of accountability as key element of ethical practice, the call for EBP in traumatic bereavement is compelling. Using examples from work carried out in Northern Ireland, we look at the backdrop of the issues involved, describe some of the most commonly used therapeutic interventions, and explore the possibility of evidence-based practice.

The postmodernist war on evidence-based practice

In this paper, we examine the war of words between those who contend that health care practice, including nursing, should primarily be informed by research (the evidence-based practice movement), and those who argue that there should be no restrictions on the sources of knowledge used by practitioners (the postmodernists). We review the postmodernist interventions of Dave Holmes and his colleagues, observing that the postmodernist style to which they adhere, which includes the use of continental philosophy, metaphors, and acerbic delivery, tends to obscure their substantive arguments. The heated nature of some responses to them has tended to have the same effect. However, the substantive arguments are important. Five main postmodernist charges are identified and discussed. The first argument, that the notion of ‘best evidence’ implies a hierarchical and exclusivist approach to knowledge, is persuasive. However, the contention that this hierarchy is maintained by the combined pressures of capitalism and vested interests within academia and the health services, is less well founded. Nevertheless, postmodernist contentions that the hierarchy embraced by the evidence-based practice movement damages health care because it excludes other forms of evidence that are needed to understand the complexity of care, it marginalizes important aspects of clinical knowledge, and it fails to take account of individuals or their experience, are all seen to be of some merit. However, we do not share the postmodernist conclusion that this adds up to a fascist order. Instead, we characterize evidence-based practice as a necessary but not sufficient component of health care knowledge.

Fundamental patterns of knowing in nursing: The challenge of evidence-based practice

This article reconsiders the fundamental patterns of knowing in nursing in light of the challenge of narrowempirics in the formof evidence-based practice. Objections to the dominance of evidence-based practice are reviewed, and the reasons for it are examined. It is argued that it is partially the result of weaknesses in the alternative patterns of ethical, personal, and esthetic knowing, the ineffability of which compromises accountability. This ineffability can be countered only by introducing a wider form of empirics than countenanced by evidencebased practice into all patterns of knowing, to demonstrate their salience and to make their use in practice transparent.