Refractive indices with Haag-Streit Lenstar biometer

Purpose: To estimate refractive indices used with the Lenstar biometer. Methods: Axial lengths of model eyes were determined using an IOLMaster biometer and a Lenstar; comparing these lengths gave an overall eye index for the Lenstar. Using the Lenstar Graphical User interface, we determined that boundaries between media could be manipulated so that there were opposite changes in optical pathlength on either side of the boundary and specified changes in distances determined the ratios of media indices. These ratios were combined with the overall eye index to estimate indices. Results: The IOLMaster and Lenstar produced axial length estimates to within ±0.01 mm. Estimations of group refractive indices were 1.340, 1.341, 1.415 and 1.354 for cornea, aqueous, lens and overall eye, respectively. The aqueous and lens indices, but not those for the cornea, are similar to schematic eye indices and reasonable lens indices. Conclusion: The Lenstar appears to use different refractive indices for different ocular media.

Refractive indices used by the Haag-Streit Lenstar to calculate axial biometric dimensions

PURPOSE To estimate refractive indices used by the Lenstar biometer to translate measured optical path lengths into geometrical path lengths within the eye. METHODS Axial lengths of model eyes were determined using the IOLMaster and Lenstar biometers; comparing those lengths gave an overall eye refractive index estimate for the Lenstar. Using the Lenstar Graphical User Interface, we noticed that boundaries between media could be manipulated and opposite changes in optical path lengths on either side of the boundary could be introduced. Those ratios were combined with the overall eye refractive index to estimate separate refractive indices. Furthermore, Haag-Streit provided us with a template to obtain 'air thicknesses' to compare with geometrical distances. RESULTS The axial length estimates obtained using the IOLMaster and the Lenstar agreed to within 0.01 mm. Estimates of group refractive indices used in the Lenstar were 1.340, 1.341, 1.415, and 1.354 for cornea, aqueous, lens, and overall eye, respectively. Those refractive indices did not match those of schematic eyes, but were close in the cases of aqueous and lens. Linear equations relating air thicknesses to geometrical thicknesses were consistent with our findings. CONCLUSION The Lenstar uses different refractive indices for different ocular media. Some of the refractive indices, such as that for the cornea, are not physiological; therefore, it is likely that the calibrations in the instrument correspond to instrument-specific corrections and are not the real optical path lengths.

Inhibiting outrage: tactics and counter-tactics in legal cases of sexual harassment

Sexual harassment can be conceptualised as an interaction between harassers and targets. Utilising 23 detailed legal transcripts, this study explored evidence of a range of perpetrator tactics and target counter-tactics. These tactics can be readily fitted into the backfire framework, which proposes that powerful perpetrators of perceived unjust acts are likely to cover up the actions, devalue the target, reinterpret the events, use official channels to give an appearance of justice, and intimidate or bribe people involved. Targets can respond using counter-tactics of exposure, validation, reframing, mobilisation of support, and resistance. The findings have implications for raising awareness of harassing tactics and recommendations for effective informal responses in organisations.

Enforcing minimum labour standards in Australia from 2010 : correcting or compounding problems

Fair Work Australia is to provide the institutional framework for the Australian industrial relations system from January 2010. Its creation provides the opportunity to improve minimum labour standards’ enforcement in Australia. However, the experience of the past must be appreciated and traditional assumptions about the operation of the Australian enforcement system discarded if the new institution is to be effective in its role. This paper focuses on the role of unions in enforcement as well as institutional location issues to expose a number of central enforcement problems that those seeking to establish new systems and processes should consider. A number of recommendations in respect of the structure of Fair Work Australia and the continuing role of unions are suggested.

Individual firms and regional business clusters : the HRM advantage in rent generation

Much of the literature on clusters has focused on the economic advantages of clusters and how these can be achieved in terms of competition, regional development and local spillovers. Some studies have focused at the level of the individual firm however human resource management (HRM) in individual clustered firms has received scant attention. This paper innovatively utilises the extended Resource Based View (RBV) of the firm as a framework to conceptualise the human resource processes of individual firms within a cluster. RBV is argued as a useful tool as it explains external rents outside a firm’s boundaries. The paper concludes that HRM can assist in generating rents for firms and clusters more broadly when the function supports valuable interfirm relationships important for realising inter-firm advantages.

Marketing unions to young people : recruiting and ‘rusting on’

In light of declining trade union density, specifically amongst young workers, this paper explores how trade unions are servicing and organising young people. Our specific focus is the way in which trade unions market their services to the young. We use, as a lens of analysis, the services marketing literature and the concept of an ‘experience good’ to explore trade union strategies. Based on interviews with a number of Queensland union officials, it is clear unions see the issue of recruitment of young people as significant, and that resources are being targeted on the development of innovative strategies at least in some unions.

Innovative approaches to intervention for problem drinking

Purpose of review: To critique the recent literature on telephone, correspondence-based, and computerized interventions for alcohol problems, which enhance or substitute for practitioner-delivered treatments. Recent findings: There is an unmet need for screening, assessment and intervention for alcohol problems, in part because of the difficulty in accessing such treatment within the current health care system. Research on the efficacy of correspondence or electronic (for example Internet-based) interventions is beginning to emerge. In the period 2003–2004 we identified nine acceptability or feasibility studies of these approaches and seven efficacy trials covering a wide range of settings. These modes of intervention are acceptable to patients and the public, and with careful planning, can be implemented in a variety of settings. Treatment trials demonstrate the efficacy of these interventions in reducing hazardous drinking by university students, in delaying initiation of heavy drinking in children and adolescents, and, intriguingly, in addressing insomnia among recovering alcoholics. Summary: There is strong support among potential users for alcohol interventions that employ telephone assistance, written correspondence, and the Internet. These new technologies offer the prospect of increasing the reach of interventions for problem drinking and being cost- effective alternatives or supplements to face-to-face health service delivery.

A brush with the real world : the future of inertial motion capture in live performance

3D Motion capture is a medium that plots motion, typically human motion, converting it into a form that can be represented digitally. It is a fast evolving field and recent inertial technology may provide new artistic possibilities for its use in live performance. Although not often used in this context, motion capture has a combination of attributes that can provide unique forms of collaboration with performance arts. The inertial motion capture suit used for this study has orientation sensors placed at strategic points on the body to map body motion. Its portability, real-time performance, ease of use, and its immunity from line-of-sight problems inherent in optical systems suggest it would work well as a live performance technology. Many animation techniques can be used in real-time. This research examines a broad cross-section of these techniques using four practice-led cases to assess the suitability of inertial motion capture to live performance. Although each case explores different visual possibilities, all make use of the performativity of the medium, using either an improvisational format or interactivity among stage, audience and screen that would be difficult to emulate any other way. A real-time environment is not capable of reproducing the depth and sophistication of animation people have come to expect through media. These environments take many hours to render. In time the combination of what can be produced in real-time and the tools available in a 3D environment will no doubt create their own tree of aesthetic directions in live performance. The case study looks at the potential of interactivity that this technology offers.

Inertial motion capture and live performance (with a focus on dance)

3D Motion capture is a fast evolving field and recent inertial technology may expand the artistic possibilities for its use in live performance. Inertial motion capture has three attributes that make it suitable for use with live performance; it is portable, easy to use and can operate in real-time. Using four projects, this paper discusses the suitability of inertial motion capture to live performance with a particular emphasis on dance. Dance is an artistic application of human movement and motion capture is the means to record human movement as digital data. As such, dance is clearly a field in which the use of real-time motion capture is likely to become more common, particularly as projected visual effects including real-time video are already often used in dance performances. Understandably, animation generated in real-time using motion capture is not as extensive or as clean as the highly mediated animation used in movies and games, but the quality is still impressive and the ‘liveness’ of the animation has compensating features that offer new ways of communicating with an audience.

Nursing resource implications of the unoccupied bed

Objective: To explore the specific factors that impact on nursing resources in relation to the ‘unoccupied bed’. Design: Descriptive observational Setting: Multiple wards in single site, tertiary referral hospital Main outcome measure: Identification and classification of tasks related to the unoccupied bed. Results: Our study identified three main areas of nursing work, which centre on the ‘unoccupied bed’: 1) bed preparation for admission; 2) temporary transfer; 3) bed preparation post patient discharge. Conclusion: The unoccupied bed is not resource neutral and may involve considerable nursing time. The time associated with each of the reasons for the bed being unoccupied remains to be quantified.

Pre-Admission and Post-Hospital Management of Heart Failure in Patients not Enrolled in Specialist Programs

Aim: To review the management of heart failure in patients not enrolled in specialist multidisciplinary programs. Method: A prospective clinical audit of patients admitted to hospital with either a current or past diagnosis of heart failure and not enrolled in a specialist heart failure program or under the direct care of the cardiology unit. Results: 81 eligible patients were enrolled (1 August to 1 October 2008). The median age was 81 9.4 years and 48% were male. Most patients (63%) were in New York Heart Association Class II or Class III heart failure. On discharge, 59% of patients were prescribed angiotensin converting enzyme inhibitors and 43% were prescribed beta-blockers. During hospitalisation, 8.6% of patients with a past diagnosis of heart failure were started on an angiotensin converting enzyme inhibitor and 4.9% on a beta-blocker. There was evidence of suboptimal dosage on admission and discharge for angiotensin converting enzyme inhibitors (19% and 7.4%) and beta-blockers (29% and 17%). The results compared well with international reports regarding the under-treatment of heart failure. Conclusion: The demonstrated practice gap provides excellent opportunities for the involvement of pharmacists to improve the continuation of care for heart failure patients discharged from hospital in the areas of medication management review, dose titration and monitoring.

Can partial coherence interferometry be used to determine retinal shape?

Purpose: To determine likely errors in estimating retinal shape using partial coherence interferometric instruments when no allowance is made for optical distortion. Method: Errors were estimated using Gullstrand’s No. 1 schematic eye and variants which included a 10 D axial myopic eye, an emmetropic eye with a gradient-index lens, and a 10.9 D accommodating eye with a gradient-index lens. Performance was simulated for two commercial instruments, the IOLMaster (Carl Zeiss Meditec) and the Lenstar LS 900 (Haag-Streit AG). The incident beam was directed towards either the centre of curvature of the anterior cornea (corneal-direction method) or the centre of the entrance pupil (pupil-direction method). Simple trigonometry was used with the corneal intercept and the incident beam angle to estimate retinal contour. Conics were fitted to the estimated contours. Results: The pupil-direction method gave estimates of retinal contour that were much too flat. The cornea-direction method gave similar results for IOLMaster and Lenstar approaches. The steepness of the retinal contour was slightly overestimated, the exact effects varying with the refractive error, gradient index and accommodation. Conclusion: These theoretical results suggest that, for field angles ≤30º, partial coherence interferometric instruments are of use in estimating retinal shape by the corneal-direction method with the assumptions of a regular retinal shape and no optical distortion. It may be possible to improve on these estimates out to larger field angles by using optical modeling to correct for distortion.