Attention modulates spatial priority maps in the human occipital, parietal and frontal cortices.

Computational theories propose that attention modulates the topographical landscape of spatial 'priority' maps in regions of the visual cortex so that the location of an important object is associated with higher activation levels. Although studies of single-unit recordings have demonstrated attention-related increases in the gain of neural responses and changes in the size of spatial receptive fields, the net effect of these modulations on the topography of region-level priority maps has not been investigated. Here we used functional magnetic resonance imaging and a multivariate encoding model to reconstruct spatial representations of attended and ignored stimuli using activation patterns across entire visual areas. These reconstructed spatial representations reveal the influence of attention on the amplitude and size of stimulus representations within putative priority maps across the visual hierarchy. Our results suggest that attention increases the amplitude of stimulus representations in these spatial maps, particularly in higher visual areas, but does not substantively change their size

Development of an Open Source Connected Autonomous Rover (OSCAR) for Under Canopy Row Crop Sampling

High density sampling of row cropping systems can enable a variety of agronomic research that is currently too labor intensive to feasibly pursue by hand. While aerial drones are commonly used to collect field data, there are numerous measurements of interest that require sensors deployed under the crop canopy. This project examines the development of a robust autonomous rover (OSCAR) that can travel through rows of corn throughout the growing season. OSCAR has a 22” wheelbase with differential steering allowing it to navigate through corn rows without damaging the plants. OSCAR is equipped with an RTK GNSS module and stereo vision camera which allows it to navigate through rows autonomously. The robot’s ability to reliably navigate and avoid obstacles continues to be improved upon in simulation and in real fields

Revisiting Educational Policies and Priorities in Commonwealth Small States

The article can be viewed at: http://www.cedol.org/wp-content/uploads/2012/02/Michael-Crossley-article.pd

Revisiting Educational Policies and Priorities in Commonwealth Small States

The article can be viewed at: http://www.cedol.org/wp-content/uploads/2012/02/Michael-Crossley-article.pd

Learning from Commonwealth small states: educational policies and priorities beyond 2015

The article can be viewed at http://www.cedol.org/wp-content/uploads/2013/09/Learning-from-Commonwealth-Crossley-et-al.pd

Interfacing GHz-bandwidth heralded single photons with a room-temperature Raman quantum memory

Photonics is a promising platform for quantum technologies. However, photon sources and two-photon gates currently only operate probabilistically. Large-scale photonic processing will therefore be impossible without a multiplexing strategy to actively select successful events. High time-bandwidth-product quantum memories - devices that store and retrieve single photons on-demand - provide an efficient remedy via active synchronisation. Here we interface a GHz-bandwidth heralded single-photon source and a room-temperature Raman memory with a time-bandwidth product exceeding 1000. We store heralded single photons and observe a clear influence of the input photon statistics on the retrieved light, which agrees with our theoretical model. The preservation of the stored field's statistics is limited by four-wave-mixing noise, which we identify as the key remaining challenge in the development of practical memories for scalable photonic information processing

Ultrahigh and persistent optical depths of caesium in Kagom\'e-type hollow-core photonic crystal fibres

Alkali-filled hollow-core fibres are a promising medium for investigating light-matter interactions, especially at the single-photon level, due to the tight confinement of light and high optical depths achievable by light-induced atomic desorption. However, until now these large optical depths could only be generated for seconds at most once per day, severely limiting the practicality of the technology. Here we report the generation of highest observed transient ($>10^5$ for up to a minute) and highest observed persistent ($>2000$ for hours) optical depths of alkali vapours in a light-guiding geometry to date, using a caesium-filled Kagom\'e-type hollow-core photonic crystal fibre. Our results pave the way to light-matter interaction experiments in confined geometries requiring long operation times and large atomic number densities, such as generation of single-photon-level nonlinearities and development of single photon quantum memories.Comment: Author Accepted versio

Spin susceptibility of the superfluid 3^{3}He-B in aerogel

The temperature dependence of paramagnetic susceptibility of the superfluid ^{3}He-B in aerogel is found. Calculations have been performed for an arbitrary phase shift of s-wave scattering in the framework of BCS weak coupling theory and the simplest model of aerogel as an aggregate of homogeneously distributed ordinary impurities. Both limiting cases of the Born and unitary scattering can be easily obtained from the general result. The existence of gapless superfluidity starting at the critical impurity concentration depending on the value of the scattering phase has been demonstrated. While larger than in the bulk liquid the calculated susceptibility of the B-phase in aerogel proves to be conspicuously smaller than that determined experimentally in the high pressure region.Comment: 10 pages, 4 figures, REVTe