Simultaneous demultiplexing and clock recovery using a single electroabsorption modulator in a novel bi-directional configuration

A single electroabsorption modulator was used to demultiplex a 10 Gbit/s channel from a 40 Gbit/s OTDM data stream, whilst simultaneously recovering the 10 GHz electrical clock. This was achieved using a new bi-directional operation of the EA modulator, combined with a simple phase-locked loop feedback circuit. Excellent system performance was achieved, indicating that operation up to and beyond 100 Gbit/s is possible using current technology.

43Gbit/s RZ-DQPSK transmission over 1000km of G.652 ultra-low-loss fibre with 250km amplifier spans

We demonstrate 40x43Gbit/s RZ-DQPSK transmission over 1000km of ultra-low-loss G.652 fibre with 250km amplifier spacing. Hybrid Raman-EDFA amplification with co- and contra-directional Raman pumping enables 27dB Raman gain per span and error-free post-FEC performance. ©2010 IEEE.

Supply chain "mega-trends":current status and future trends

The supply chain management (SCM) concept has become embedded in the thinking of many organisations in recent years. Originally introduced by management consultants in the early 1980s, SCM has a strong focus on integration of processes across functions within firms, as well as between the organisations that comprise the wider extended enterprise. There is a significant body of research to support the notion that the consistent delivery of value to customers is predicated on higher levels of intra-firm and inter-firm integration. Putting the supply chain integration (SCI) concept into practice is critically dependent on the ability of firms to manage material, money and information flows in a holistic manner. It also depends on the way in which relationships between key supply chain actors are managed. This article explores the “mega-trends” that are evident across most sectors and which have a potentially significant impact on the ability of organisations to put SCM theory into practice. The late Don Bowersox and his colleagues from Michigan State University introduced the idea of supply chain “mega-trends” over a decade ago in their widely cited article in the Journal of Business Logistics (Bowersox et al., 2000). This article explores the current status of these “mega-trends” in an Irish context based on research being undertaken at the National Institute for Transport and Logistics (NITL). It also identifies some key factors that are likely to impact upon progress in these key areas in the medium term.

A hybrid current controller for linear reciprocating vapor compressors

Direct-drive linear reciprocating compressors offer numerous advantages over conventional counterparts which are usually driven by a rotary induction motor via crank shaft However, to ensure efficient and reliable operation under all conditions, it is essential that the motor current of the linear compressor follows a sinusoidal command profile with a frequency which matches the system resonant frequency. This paper describes a hybrid current controller for the linear compressors. It comprises a conventional proportional-integral (PI) controller, and a B-spline neural network compensator which is trained on-line and in real-time in order to minimize the current tracking error under all conditions with uncertain disturbances. It has been shown that the hybrid current controller has a superior steady-state and transient performance over the conventional carrier based PI controller. The performance of the proposed hybrid controller has been demonstrated by extensive simulations and experiments. It has also been shown that the linear compressor operates stably under the current feedback control and the piston stroke can be adjusted by varying the amplitude of the current command. © 2007 IEEE.

The UK MPharm (1) - are we over reliant on traditional teaching methods?

Introduction-The design of the UK MPharm curriculum is driven by the Royal Pharmaceutical Society of Great Britain (RPSGB) accreditation process and the EU directive (85/432/EEC).[1] Although the RPSGB is informed about teaching activity in UK Schools of Pharmacy (SOPs), there is no database which aggregates information to provide the whole picture of pharmacy education within the UK. The aim of the teaching, learning and assessment study [2] was to document and map current programmes in the 16 established SOPs. Recent developments in programme delivery have resulted in a focus on deep learning (for example, through problem based learning approaches) and on being more student centred and less didactic through lectures. The specific objectives of this part of the study were (a) to quantify the content and modes of delivery of material as described in course documentation and (b) having categorised the range of teaching methods, ask students to rate how important they perceived each one for their own learning (using a three point Likert scale: very important, fairly important or not important). Material and methods-The study design compared three datasets: (1) quantitative course document review, (2) qualitative staff interview and (3) quantitative student self completion survey. All 16 SOPs provided a set of their undergraduate course documentation for the year 2003/4. The documentation variables were entered into Excel tables. A self-completion questionnaire was administered to all year four undergraduates, using a pragmatic mixture of methods, (n=1847) in 15 SOPs within Great Britain. The survey data were analysed (n=741) using SPSS, excluding non-UK students who may have undertaken part of their studies within a non-UK university. Results and discussion-Interviews showed that individual teachers and course module leaders determine the choice of teaching methods used. Content review of the documentary evidence showed that 51% of the taught element of the course was delivered using lectures, 31% using practicals (includes computer aided learning) and 18% small group or interactive teaching. There was high uniformity across the schools for the first three years; variation in the final year was due to the project. The average number of hours per year across 15 schools (data for one school were not available) was: year 1: 408 hours; year 2: 401 hours; year 3: 387 hours; year 4: 401 hours. The survey showed that students perceived lectures to be the most important method of teaching after dispensing or clinical practicals. Taking the very important rating only: 94% (n=694) dispensing or clinical practicals; 75% (n=558) lectures; 52% (n=386) workshops, 50% (n=369) tutorials, 43% (n=318) directed study. Scientific laboratory practices were rated very important by only 31% (n=227). The study shows that teaching of pharmacy to undergraduates in the UK is still essentially didactic through a high proportion of formal lectures and with high levels of staff-student contact. Schools consider lectures still to be the most cost effective means of delivering the core syllabus to large cohorts of students. However, this does limit the scope for any optionality within teaching, the scope for small group work is reduced as is the opportunity to develop multi-professional learning or practice placements. Although novel teaching and learning techniques such as e-learning have expanded considerably over the past decade, schools of pharmacy have concentrated on lectures as the best way of coping with the huge expansion in student numbers. References [1] Council Directive. Concerning the coordination of provisions laid down by law, regulation or administrative action in respect of certain activities in the field of pharmacy. Official Journal of the European Communities 1985;85/432/EEC. [2] Wilson K, Jesson J, Langley C, Clarke L, Hatfield K. MPharm Programmes: Where are we now? Report commissioned by the Pharmacy Practice Research Trust., 2005.

The UK MPharm (2) - Do we over assess?

Introduction-The pace of structural change in the UK health economies, the new focus on regulation and the breaking down of professional boundaries means that the Royal Pharmaceutical Society of Great Britain (RPSGB) has to continually review the scope, range and outputs of education provided by schools of pharmacy (SOPs). In SOPs, the focus is on equipping students with the knowledge, skills and attitudes necessary to successfully engage with the pre-registration year. The aim of this study [1] was to map current programmes and undergraduate experiences to inform the RPSGB debate. The specific objectives of this paper are to describe elements of the survey of final year undergraduates, to explore student opinions and experiences of their workload, teaching, learning and assessment. Material and methods-The three main research techniques were: (1) quantitative course document review, (2) qualitative staff interview and (3) quantitative student self completion survey. The questions in the survey were based on findings from exploratory focus group work with BPSA (British Pharmaceutical Students’ Association) members and were designed to ascertain if views expressed in the focus groups on the volume and format of assessments were held by the general student cohort. The student self completion questionnaire consisting of 31 questions, was administered in 2005 to all (n=1847) final year undergraduates, using a pragmatic mixture of methods. The sample was 15 SOPs within the UK (1 SOP opted out). The total response rate was 50.62% (n=935): it varied by SOP from 14.42% to 84.62%. The survey data were analysed (n=741) using SPSS, excluding non-UK students who may have undertaken part of their studies within a non-UK university. Results and discussion • 76% (n=562) respondents considered that the amount of formal assessment was about right, 21% (n=158) thought it was too much. • There was agreement that the MPharm seems to have more assessment than other courses, with 63% (n=463) strongly agreeing or agreeing. • The majority considered the balance between examinations and coursework was about right (67%, n=498), with 27% (n=198) agreeing that the balance was too far weighted towards examinations. • 57% (n=421) agreed that the focus of MPharm assessment was too much towards memorised knowledge, 40% (n=290) that it was about right. • 78% (n= 575) agreed with the statement “Assessments don’t measure the skills for being a pharmacist they just measure your knowledge base”. Only 10% (n=77) disagreed. • Similarly 49% (n=358) disagreed with, and 35% (n=256) were not sure about the statement “I consider that the assessments used in the MPharm course adequately measure the skills necessary to be a pharmacist”. Only 17% (n=124) agreed. Experience from this study shows the difficulty of administering survey instruments through UK Schools of Pharmacy. It is heavily dependent on timing, goodwill and finding the right person. The variability of the response rate between SOPs precluded any detailed analysis by School. Nevertheless, there are some interesting results. Issues raised in the exploratory focus group work about amount of assessment and over reliance on knowledge have been confirmed. There is a real debate to be had about the extent to which the undergraduate course, which must instil scientific knowledge, can provide students with the requisite qualities, skills, attitudes and behaviour that are more easily acquired in the pre-registration year. References [1] Wilson K, Jesson J, Langley C, Clarke L, Hatfield K. MPharm Programmes: Where are we now? Report commissioned by the Pharmacy Practice Research Trust., 2005.

Some new Results for Additive Self-Dual Codes over GF(4)

* Supported by COMBSTRU Research Training Network HPRN-CT-2002-00278 and the Bulgarian National Science Foundation under Grant MM-1304/03.

Management research in India:current state and future directions

Concerned over the lack of high quality, context specific management research in India, and the predilection of Indian researchers to follow Western models of research and publication blindly, the authors take stock of Indian management research in this round table discussion and debate some of the relevant issues. Urging Indian researchers to strive for the levels of rigour of the Western models, they make a case for confident indigenous scholarship to suit the development and educational requirements of the country, following context-relevant constructs and methodologies in research and developing curricula, materials and modes of dissemination independently. These ideas were also explored at the second Indian Academy of Management Conference held at IIM Bangalore in December 2011. © 2012 Indian Institute of Management Bangalore.

Unrepeatered Nyquist PDM-16QAM transmission over 364 km using Raman amplification and multi-channel digital back-propagation

Transmission of a net 467-Gb/s PDM-16QAM Nyquist-spaced superchannel is reported with an intra-superchannel net spectral efficiency (SE) of 6.6 (b/s)/Hz, over 364-km SMF-28 ULL ultra-low loss optical fiber, enabled by bi-directional second-order Raman amplification and digital nonlinearity compensation. Multi-channel digital back-propagation (MC-DBP) was applied to compensate for nonlinear interference; an improvement of 2 dB in Q2 factor was achieved when 70-GHz DBP bandwidth was applied, allowing an increase in span length of 37 km.

Evaluating digital diabetic retinopathy screening in people aged 90 years and over

To evaluate the effectiveness of digital diabetic retinopathy screening in patients aged 90 years and over.MethodsThis is a retrospective analysis of 200 randomly selected patients eligible for diabetic retinopathy screening aged 90 years and over within the Birmingham, Solihull, and Black Country Screening Programme.ResultsOne hundred and seventy-nine (90%) patients attended screening at least once. 133 (74%) annual screening after their first screen, of whom 59% had no detectable diabetic retinopathy; 38 (21%) were referred for ophthalmology clinical assessment-36 for nondiabetic retinopathy reasons and two for diabetic maculopathy. Cataract accounted for 50% of all referrals for ophthalmology clinical assessment. Of the 133 patients placed on annual screening, 93 (70%) were screened at least once more. In terms of level of diabetic retinopathy, assessability or other ocular pathologies, 8 improved, 51 remained stable, and 31 deteriorated. Of the latter, 19 patients were referred for ophthalmology clinical assessment; none of these for diabetic retinopathy.ConclusionsScreening provides opportunistic identification of important nondiabetic retinopathy eye conditions. However, in view of the low identification rate of sight-threatening diabetic retinopathy in patients aged 90 years and over, and the current mission statement of the NHS Diabetic Eye Screening Programme, systematic annual diabetic retinopathy screening may not be justified in this age group of patients, but rather be performed in optometric practice.

Directional mobility of debt ratings

In this paper we describe a method to decompose a well-known measure of debt ratings mobility into it's directional components. We show, using sovereign debt ratings as an example, that this directional decomposition allows us to better understand the underlying characteristics of debt ratings migration and, for the case of the data set used, that the standard Markov chain model is not homogeneous in either the time or cross-sectional dimensions. We find that the directional decomposition also allows us to sign the change in quality of debt over time and across sub-groups of the population.

Crowdsourcing, citizen science or volunteered geographic information? The current state of crowdsourced geographic information

Citizens are increasingly becoming an important source of geographic information, sometimes entering domains that had until recently been the exclusive realm of authoritative agencies. This activity has a very diverse character as it can, amongst other things, be active or passive, involve spatial or aspatial data and the data provided can be variable in terms of key attributes such as format, description and quality. Unsurprisingly, therefore, there are a variety of terms used to describe data arising from citizens. In this article, the expressions used to describe citizen sensing of geographic information are reviewed and their use over time explored, prior to categorizing them and highlighting key issues in the current state of the subject. The latter involved a review of 100 Internet sites with particular focus on their thematic topic, the nature of the data and issues such as incentives for contributors. This review suggests that most sites involve active rather than passive contribution, with citizens typically motivated by the desire to aid a worthy cause, often receiving little training. As such, this article provides a snapshot of the role of citizens in crowdsourcing geographic information and a guide to the current status of this rapidly emerging and evolving subject.

Four-leg converters with improved common current sharing and selective voltage-quality enhancement for islanded microgrids

Four-leg dc-ac power converters are widely used for the power grids to manage grid voltage unbalance caused by the interconnection of single-phase or three-phase unbalanced loads. These converters can further be connected in parallel to increase the overall power rating. The control of these converters poses a particular challenge if they are placed far apart with no links between them (e.g., in islanded microgrids). This challenge is studied in this paper with each four-leg converter designed to have improved common current sharing and selective voltage-quality enhancement. The common current sharing, including zero sequence component, is necessary since loads are spread over the microgrid and they are hence the common responsibility of all converters. The voltage-quality enhancement consideration should however be more selective since different loads have different sensitivity levels towards voltage disturbances. Converters connected to the more sensitive load buses should therefore be selectively triggered for compensation when voltage unbalances at their protected buses exceed the predefined thresholds. The proposed scheme is therefore different from conventional centralized schemes protecting only a common bus. Simulation and experimental results obtained have verified the effectiveness of the proposed scheme when applied to a four-wire islanded microgrid.

Pharmacology and therapeutic implications of current drugs for type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a global epidemic that poses a major challenge to health-care systems. Improving metabolic control to approach normal glycaemia (where practical) greatly benefits long-term prognoses and justifies early, effective, sustained and safety-conscious intervention. Improvements in the understanding of the complex pathogenesis of T2DM have underpinned the development of glucose-lowering therapies with complementary mechanisms of action, which have expanded treatment options and facilitated individualized management strategies. Over the past decade, several new classes of glucose-lowering agents have been licensed, including glucagon-like peptide 1 receptor (GLP-1R) agonists, dipeptidyl peptidase 4 (DPP-4) inhibitors and sodium/glucose cotransporter 2 (SGLT2) inhibitors. These agents can be used individually or in combination with well-established treatments such as biguanides, sulfonylureas and thiazolidinediones. Although novel agents have potential advantages including low risk of hypoglycaemia and help with weight control, long-term safety has yet to be established. In this Review, we assess the pharmacokinetics, pharmacodynamics and safety profiles, including cardiovascular safety, of currently available therapies for management of hyperglycaemia in patients with T2DM within the context of disease pathogenesis and natural history. In addition, we briefly describe treatment algorithms for patients with T2DM and lessons from present therapies to inform the development of future therapies.

A forgalomban lévő fásszárú dísznövénytaxonok szárazságtűrésének értékelése a klímaváltozás tükrében (Evaluation of the impact climate change on current drought-tolerant woody plants)

Regionális klímaváltozási forgatókönyvek szerint hazánk éghajlata az elkövetkező 90 évben a mainál jóval melegebb, a nyári évszakban csapadékszegényebb, összességében pedig szárazabb lesz. Kutatásunk célja volt felmérni szárazságtűrésük szerint a legjelentősebb faiskolák katalógusában fellelhető fa- és cserjefajokat (a gyűjtésben nem szerepelnek a faj alatti taxonok). A vizsgálatainkban szereplő öt faiskola növénykínálatát a tudományos nevek ellenőrzése után összesítettük, majd ezt követően az egyes fajokat vízigény szerinti kategóriákba soroltuk. A tényleges statisztikai értékelésbe – a 451 összegyűjtött faj tudományos neveinek ellenőrzése után – 420 fajt vontunk be, melyek 20%-a vízigényes, 53%-a közepesen vízigényes és 27%-a szárazságtűrő. Várakozásainkkal ellentétben a vízigényes fajok részaránya kevésnek mondható, ugyanakkor a szárazságtűrő fajok magasabb aránya kívánatos lenne. Ezért, a gyakorlati alkalmazást elősegítve, kiemeltünk olyan nemzetségeket, melyek kereskedelmi forgalmazását meg kellene kezdeni vagy fokozni, mint pl a Cupressus, Eucommia, Halimodendron, Paliurus, Pyrus, Rhus, Yucca Zanthoxylum, Zelkova, illetve olyanokat, melyek telepítését a jövőben nem, vagy csak kellő körültekintéssel javasoljuk, mint például a Clematis, Hydrangea, Liquidambar, Magnolia, Rhododendron nemzetségek. _____ According to regional climate change scenarios, the climate in Hungary will be warmer. Less precipitation is predicted in the summer seasons so, on the whole, it will be drier over the next 90 years. Our research attempted to survey the ornamental plant species in the most important nurseries in Hungary, in terms of their drought tolerance. The intraspecifi c taxa are not included. The plant assortment of the fi ve nurseries was merged after researching their scientifi c names. We then categorized species to 3 groups of drought tolerance. Out of 451 species, 420 of them were used in the statistical research. 20% of them were water demanding, 53% were medium drought tolerant and 27% were drought tolerant. In contrast to our initial expectation, the proportion of water demanding species was not too high. Nevertheless, the proportion of drought tolerant species should have been greater. We classifi ed the genera to assist in practical application. The trade of some of these species, such as Cupressus, Eucommia, Halimodendron, Paliurus, Pyrus, Rhus, Yucca, Zanthoxylum, Zelkova should be initiated or increased in the future. Other species, especially Clematis, Hydrangea, Liquidambar, Magnolia, Rhododendron are not recommended due to either their drought intolerance or their high maintenance requirement.