Phase dependent forward three wave amplification in photorefractive BSO

The results of three wave mixing experiments in photorefractive Bi12SiO20 are presented. The results confirm theoretical predictions that amplification by three wave mixing is strongly dependent on the phase relationship between the three beams at the input to the medium.

Low thermal sensitivity grating devices based on ex-45° tilting structure capable of forward-propagating cladding modes coupling

The authors describe a detailed investigation on tilted fiber Bragg grating (TFBG) structures with tilted angles exceeding 45°. In contrast to the backward mode coupling mechanism of Bragg gratings with normal and small tilting structures, the ex-45° TFBGs facilitate the light coupling to the forward-propagating cladding modes. The authors have also theoretically and experimentally examined the mode coupling transition of TFBGs with small, medium, and large tilt angles. In particular, experiments are conducted to investigate the spectra and far-field distribution, as well as temperature, strain, and refractive-index sensitivities of ex-45° devices. It has been revealed that these ex-45° gratings exhibit ultralow thermal sensitivity. As in-fiber devices, they may be superior to conventional Bragg and long-period gratings when the low thermal cross sensitivity is required.

Effects of yellow filters on visual acuity, contrast sensitivity and reading under conditions of forward light scatter

Background Yellow filters are sometimes recommended to people with low vision. Our aim was investigate the effects of three commercial yellow filters on visual acuity and contrast sensitivity (with and without glare) and reading (without glare) under conditions of forward light scatter (FLS). Method Fifty-five healthy subjects were assessed with Corning Photochromic Filters (CPFs) 450, 511 and 527 and a filter producing FLS. The effects on log MAR visual acuity, Pelli–Robson contrast sensitivity with and without glare, and reading (measured with MNRead charts) without glare were determined. Results Statistically significant differences were found between the overall effect of glare and between CPFs for visual acuity and contrast sensitivity. A gradual decline in visual acuity, contrast sensitivity and reading with increasing CPF absorption was noted. Conclusion Effects of CPF450, 511, 527 on visual acuity, contrast sensitivity and reading under conditions of FLS were negative but not clinically significant.

Developing the public health function of locum pharmacists under the auspices of the new pharmacy contract

Focal Point - There are reduced opportunities for locum pharmacists to access training and education that meets their needs and enables them to play a full role under the new pharmacy contract - Eighty-six per cent of locums consider themselves to be more health professional than business person, compared to just 48% of pharmacy owners - Forty per cent of locums believe that a lack of access to training is a major barrier to the development of their public health function - While locum pharmacists are arguably more likely to embrace 'professionalising', patient-care-based roles, they are also the group least likely to be able to access the necessary training to fulfill such roles Introduction It has been suggested that locum pharmacists do not want the business-based responsibilities (e.g. staff management, meeting targets, etc) that come with pharmacy management.1 Research also suggests that locums derive great satisfaction from the health-professional aspects of the pharmacists’ role (e.g. patient contact, the provision of advice, etc).1 However, upon the introduction of the new pharmacy contract (April 2005), concerns were expressed that it was becoming increasingly difficult for locum pharmacists to access training and education that would meet their needs and enable them to play a full role under the new framework.2,3 Method After piloting, in August 2006 a self-completion postal questionnaire was sent to a random sample of practising community pharmacists, stratified for country and sex, within Great Britain (n = 1998), with a follow-up to non-responders 4 weeks later. Data were analysed using SPSS (v12.0). A final response rate of 51% (n = 1023/1998) was achieved. Respondents were asked ‘indicate how you view yourself as a pharmacist’ – in terms of their relative focus on the health-professional and business aspects of their role. Respondents were also asked ‘do you consider a lack of training opportunities to be a barrier to the development of the public health role of community pharmacists?’. Results Locums were significantly more likely than owners or employees to consider each factor a major barrier. Discussion Four in 10 locums consider a lack of training opportunities to constitute a major barrier to the development of their public health function. Pharmacy may not be able to provide the services required of it by the policy agenda if pharmacists are unable to be involved in extended role activities through a lack of training opportunities. Therefore, the paradox that needs to be addressed is that while locum pharmacists are arguably more likely to embrace ‘professionalising’, patient-care-based roles, they are also the group least likely to be able to access training to fulfil such roles. The training needs of this large subset of the pharmacist population need to be assessed and met if the whole community pharmacy workforce is going to maximise its contribution to public health under the new contractual framework. References 1 Shann P, Hassell K. An exploration of the diversity and complexity of the pharmacy locum workforce. London: Royal Pharmaceutical Society of Great Britain; 2004. 2 Almond M. Locums – key players in workforce – cast adrift as contract launched. Pharm J 2005;274:420. 3 Bishop DH. A lack of appreciation of what really happens. Pharm J 2005;274:451.

Contract law concentrate

Contract Law Concentrate is a high quality revision guide which covers the main topics found on undergraduate courses. The clear, succinct coverage of key legal points within a specific topic area, including key cases, enables students to quickly grasp the fundamental principles of Contract law. Written by Jill Poole, an experienced teacher and examiner and author of Textbook on Contract Law and Casebook on Contract law. The book focuses on the needs of students to pass their exams with a number of pedagogical features which help with the preparation for exams and suggest ways to improve marks. Endorsed by students and lecturers for level of coverage, accuracy and exam advice. Online Resource Centre Interactive flashcards Glossary Exam and revision guidance.

Contract specificity and its performance outcomes

Governance theories, such as transaction cost economics, argue that systematic deviations from an attribute–governance alignment should influence performance. This article investigates the performance implications of contract specificity for the procurement of information technology products. The authors argue that parties choose a level of contract specificity that economizes on both the ex ante contracting costs and the ex post transaction costs and that deviations between the observed and the predicted levels of contract specificity are an important determinant of these transaction costs. The authors test the hypotheses using a comprehensive archival data set of information technology transactions and employ a two-step estimation procedure. First, they estimate the “predicted” level of contract specificity, which accounts for key transactional attributes. Second, they study the consequences of deviating from this predicted level of contractual specificity. The results provide the first explicit demonstration of the trade-off between ex ante contracting costs and ex post transaction problems and suggest that parties need to economize jointly on these costs when choosing the governance form.

Promoting scholarship - the way forward:learning and teaching research in a complex environment – a typology

Scholarship in learning and teaching.

Novel real-time homodyne coherent receiver using a feed-forward based carrier extraction scheme for phase modulated signals

We report a novel real-time homodyne coherent receiver based on a DPSK optical-electrical-optical (OEO) regenerator used to extract a carrier from carrier-less phase modulated signals based on feed-forward based modulation stripping. The performance of this non-DSP based coherent receiver was evaluated for 10.66Gbit/s BPSK signals. Self-homodyne coherent detection and homodyne detection with an injection-locked local oscillator laser was demonstrated. The performance was evaluated by measuring the electrical signal-to-noise (SNR) and recording the eye diagrams. Using injection-locking for the LO improves the performance and enables homodyne detection with optical injection-locking to operate with carrier-less BPSK signals without the need for polarization multiplexed pilot-tones.

Novel synchronous DPSK optical regenerator based on a feed-forward based carrier extraction scheme

We experimentally demonstrate a novel synchronous 10.66Gbit/s DPSK OEO regenerator which uses a feed-forward carrier extraction scheme with an injection-locked laser to synchronize the regenerated signal wavelength to the incoming signal wavelength. After injection-locking, a low-cost DFB laser used at the regenerator exhibited the same linewidth characteristics as the narrow line-width transmitter laser. The phase regeneration properties of the regenerator were evaluated by emulating random Gaussian phase noise applied to the DPSK signal before the regenerator using a phase modulator driven by an arbitrary waveform generator. The overall performance was evaluated in terms of electrical eye-diagrams, BER measurements, and constellation diagrams.

Full-field feed-forward equalizer with adaptive system optimization

We numerically investigate the combination of full-field detection and feed-forward equalizer (FFE) for adaptive chromatic dispersion compensation up to 2160 km in a 10 Gbit/s on-off keyed optical transmission system. The technique, with respect to earlier reports, incorporates several important implementation modules, including the algorithm for adaptive equalization of the gain imbalance between the two receiver chains, compensation of phase misalignment of the asymmetric Mach-Zehnder interferometer, and simplified implementation of field calculation. We also show that in addition to enabling fast adaptation and simplification of field calculation, full-field FFE exhibits enhanced tolerance to the sampling phase misalignment and reduced sampling rate when compared to the full-field implementation using a dispersive transmission line.

A multi-level investigation of psychological contract breach and organizational identification through the lens of perceived organizational membership:testing a moderated-mediated model

Drawing on the perceived organizational membership theoretical framework and the social identity view of dissonance theory, I examined in this study the dynamics of the relationship between psychological contract breach and organizational identification. I included group-level transformational and transactional leadership as well as procedural justice in the hypothesized model as key antecedents for organizational membership processes. I further explored the mediating role of psychological contract breach in the relationship between leadership, procedural justice climate, and organizational identification and proposed separateness–connectedness self-schema as an important moderator of the above mediated relationship. Hierarchical linear modeling results from a sample of 864 employees from 162 work units in 10 Greek organizations indicated that employees' perception of psychological contract breach negatively affected their organizational identification. I also found psychological contract breach to mediate the impact of transformational and transactional leadership on organizational identification. Results further provided support for moderated mediation and showed that the indirect effects of transformational and transactional leadership on identification through psychological contract breach were stronger for employees with a low connectedness self-schema.