Experimental demonstration of a mu=-1 metamaterial lens for magnetic resonance imaging

In this work a mu=-1 metamaterial (MM) lens for magnetic resonance imaging (MRI) is demonstrated. MRI uses surface coils to detect the radiofrequency(RF) energy absorbed and emitted by the nuclear spins in the imaged object. The proposed MM lens manipulates the RF field detected by these surface coils, so that the coil sensitivity and spatial localization is substantially improved. Beyond this specific application, we feel that the reported results are the experimental confirmation of a new concept for the manipulation of RF field in MRI, which paves the way to many other interesting applications.Comment: 9 pages, 3 figure

Peer reviews: What can we learn from our students?

This paper describes lessons learnt whilst using an online peer review system in an undergraduate unit for pre-service teachers. In this unit students learn to use information technologies as part of their future teaching practice. The unit aims to foster graduates who become life-long reflective educators by providing opportunities to explore and reflect on how they might use technology in authentic learning situations. Whilst peer review is an appropriate activity for supporting critical thinking and reflective practice in this kind of unit, it requires a number of decisions to be made in relation to student preparation and support, implementation strategy, and technological infrastructure to make it work in specific contexts. Much research has been conducted in recent years to inform educators in making these decisions. However, there are still gaps in the research, particularly in how to improve the quality and consistency of feedback that students give to each other in their feedback. This paper describes the experiences of implementing an online peer review system aiming to improve quality and consistency of feedback. This exploration has revealed that we can learn much about ways to improve our teaching practices by giving students an opportunity to review each other’s work and give each other feedback

Classification of pathology in diabetic eye disease

Proliferative diabetic retinopathy is a complication of diabetes that can eventually lead to blindness. Early identification of this complication reduces the risk of blindness by initiating timely treatment. We report the utility of pattern analysis tools linked with a simple linear discriminant analysis that not only identifies new vessel growth in the retinal fundus but also localises the area of pathology. Ten fluorescein images were analysed using seven feature descriptors including area, perimeter, circularity, curvature, entropy, wavelet second moment and the correlation dimension. Our results indicate that traditional features such as area or perimeter measures of neovascularisation associated with proliferative retinopathy were not sensitive enough to detect early proliferative retinopathy (SNR = 0.76, 0.75 respectively). The wavelet second moment provided the best discrimination with a SNR of 1.17. Combining second moment, curvature and global correlation dimension provided a 100% discrimination (SNR = 1)