Unrelenting plasmons

Following a brief historic introduction to plasmons, their useful properties and early applications, we highlight some of the key advances in the field over the past decade. We then discuss new directions for the future, such as the use of 2D materials and strong coupling phenomena, which are likely to shape the field over the next ten years. For centuries, metals were employed in optical applications only as mirrors and gratings. New vistas opened up in the late 1970s and early 1980s with the discovery of surface-enhanced Raman scattering and the use of surface plasmon (SP) resonances for sensing. However, it was not until the 1990s, with the appearance of accurate and reliable nanofabrication techniques, that plasmonics blossomed1. Initially, the attention focused on the exploitation of SPs (collective electronic oscillations at the surface of metals) for sensing, subwavelength waveguiding and extraordinary optical transmission2. Since then, the scientific and technological interest in SPs has expanded. Correspondingly, as illustrated in Fig. 1, the number of publications in the field has increased in a steady exponential fashion for more than two decades, and the momentum driving plasmonics research looks set to continue (...

Attracting and retaining health workers in rural areas: investigating nurses’ views on rural posts and policy interventions

<p>Abstract</p> <p>Background</p> <p>Kenya has bold plans for scaling up priority interventions nationwide, but faces major human resource challenges, with a lack of skilled workers especially in the most disadvantaged rural areas.</p> <p>Methods</p> <p>We investigated reasons for poor recruitment and retention in rural areas and potential policy interventions through quantitative and qualitative data collection with nursing trainees. We interviewed 345 trainees from four purposively selected Medical Training Colleges (MTCs) (166 pre-service and 179 upgrading trainees with prior work experience). Each interviewee completed a self-administered questionnaire including likert scale responses to statements about rural areas and interventions, and focus group discussions (FGDs) were conducted at each MTC.</p> <p>Results</p> <p>Likert scale responses indicated mixed perceptions of both living and working in rural areas, with a range of positive, negative and indifferent views expressed on average across different statements. The analysis showed that attitudes to working in rural areas were significantly positively affected by being older, but negatively affected by being an upgrading student. Attitudes to living in rural areas were significantly positively affected by being a student at the MTC furthest from Nairobi.</p> <p>During FGDs trainees raised both positive and negative aspects of rural life. Positive aspects included lower costs of living and more autonomy at work. Negative issues included poor infrastructure, inadequate education facilities and opportunities, higher workloads, and inadequate supplies and supervision. Particular concern was expressed about working in communities dominated by other tribes, reflecting Kenya’s recent election-related violence.</p> <p>Quantitative and qualitative data indicated that students believed several strategies could improve rural recruitment and retention, with particular emphasis on substantial rural allowances and the ability to choose their rural location. Other interventions highlighted included provision of decent housing, and more rapid career advancement. However, recently introduced short term contracts in named locations were not favoured due to their lack of pension plans and job security.</p> <p>Conclusions</p> <p>This study identified a range of potential interventions to increase rural recruitment and retention, with those most favored by nursing students being additional rural allowances, and allowing choice of rural location. Greater investment is needed in information systems to evaluate the impact of such policies.</p

Maskless Plasmonic Lithography at 22 nm Resolution

Optical imaging and photolithography promise broad applications in nano-electronics, metrologies, and single-molecule biology. Light diffraction however sets a fundamental limit on optical resolution, and it poses a critical challenge to the down-scaling of nano-scale manufacturing. Surface plasmons have been used to circumvent the diffraction limit as they have shorter wavelengths. However, this approach has a trade-off between resolution and energy efficiency that arises from the substantial momentum mismatch. Here we report a novel multi-stage scheme that is capable of efficiently compressing the optical energy at deep sub-wavelength scales through the progressive coupling of propagating surface plasmons (PSPs) and localized surface plasmons (LSPs). Combining this with airbearing surface technology, we demonstrate a plasmonic lithography with 22 nm half-pitch resolution at scanning speeds up to 10 m/s. This low-cost scheme has the potential of higher throughput than current photolithography, and it opens a new approach towards the next generation semiconductor manufacturing

The place of values in the aims of school science education

Debates about the aims of school science education are perennial (e.g., Reiss & White, 2014; see also Kidman & Fensham, Chapter “ Intended, Achieved and Unachieved Values of Science Education” this volume), particularly in Western cultures. In this chapter we review some of these arguments about the aims of school science education, and look at what has changed in the last decade since one of us (Michael) considered a similar debate (see Reiss, 2007). We have situated this review of arguments in current global circumstances including rapid technological advances, a continuing demand for workers with STEM (Science, Technology, Engineering and Mathematics) qualifications and the increasing acknowledgement of the deeply worrying effects that humans have on the Earth’s ecology, and indeed its future. Part of our argument is that decisions about the aims of school science education are inevitably decisions about values in education in general and values in school science education more specifically. This means that for a country, a group of schools, an individual school or a classroom teacher to come to a view about the aims of science education in the classroom is to have made a judgement, implicitly or explicitly, about values