An ultradiscrete matrix version of the fourth Painleve equation

We establish a matrix generalization of the ultradiscrete fourth Painlev\'e equation (ud-PIV). Well-defined multicomponent systems that permit ultradiscretization are obtained using an approach that relies on a group defined by constraints imposed by the requirement of a consistent evolution of the systems. The ultradiscrete limit of these systems yields coupled multicomponent ultradiscrete systems that generalize ud-PIV. The dynamics, irreducibility, and integrability of the matrix valued ultradiscrete systems are studied.Comment: 12 pages, 12 figures, Latex2e, Submitted to J. Phys. A, corrections mad

Monte Carlo simulation of electron and proton irradiation of carbon nanotube and graphene transistors

Carbon-based nanotechnology electronics can provide high performance, low-power and low-weight solutions, which are very suitable for innovative aerospace applications. However, its application in the space environment where there is a radiation hazard, requires an assessment of the response of such electronic products to the background irradiance. To explore the potential of carbon-based nanotechnology, Monte Carlo simulations of radiation interacting with a gate-all-around carbon nanotube (GAACNFET) and a top-gated graphene FET are presented. Geant4 is used to calculate the energy deposited into the dielectric layers and the displacement damage in the nanosemiconductors under proton and electron irradiation. Both an unshielded and two cases with 250 μm thick NiFe and Pb shielding are tested at a fluence of 1015 m-2. The energy range of the particles considered is 10-2 – 102 MeV for the unshielded and 1 – 103 MeV for the shielded case. The results indicate that the graphene transistor is more susceptible to displacement damage than the CNT-based syste

The processing of color preference in the brain

Decades of research has established that humans have preferences for some colors (e.g., blue) and a dislike of others (e.g., dark chartreuse), with preference varying systematically with variation in hue (e.g., Hurlbert & Owen, 2015). Here, we used functional MRI to investigate why humans have likes and dislikes for simple patches of color, and to understand the neural basis of preference, aesthetics and value judgements more generally. We looked for correlations of a behavioural measure of color preference with the blood oxygen level-dependent (BOLD) response when participants performed an irrelevant orientation judgement task on colored squares. A whole brain analysis found a significant correlation between BOLD activity and color preference in the posterior midline cortex (PMC), centred on the precuneus but extending into the adjacent posterior cingulate and cuneus. These results demonstrate that brain activity is modulated by color preference, even when such preferences are irrelevant to the ongoing task the participants are engaged. They also suggest that color preferences automatically influence our processing of the visual world. Interestingly, the effect in the PMC overlaps with regions identified in neuroimaging studies of preference and value judgements of other types of stimuli. Therefore, our findings extends this literature to show that the PMC is related to automatic encoding of subjective value even for basic visual features such as color

Maximising value, enhancing learning: boutique teaching and training

The chapter looks at bespoke teaching approaches to information skills teaching as part of a wider 'boutique' approach to library services in Higher Education. The learner is firmly placed at the heart of the learning experience and the implications of this approach are considered in detail

Lattice QCD with Dynamical Quarks from the UKQCD Collaboration

A brief overview of the lattice technique of studying QCD is presented. Recent results from the UKQCD Collaboration's simulations with dynamical quarks are then presented. In this work, the calculations are all at a fixed lattice spacing and volume, but varying sea quark mass from infinite (corresponding to the quenched simulation) down to roughly that of the strange quark mass. The main aim of this work is to uncover dynamical quark effects from these ``matched'' ensembles.Comment: Invited paper presented at the International Light-Cone Workshop "Light-cone Physics: Particles and Strings", September 2001, Trento, Italy. 7 page