A very brief introduction to quantum computing and quantum information theory for mathematicians

This is a very brief introduction to quantum computing and quantum information theory, primarily aimed at geometers. Beyond basic definitions and examples, I emphasize aspects of interest to geometers, especially connections with asymptotic representation theory. Proofs of most statements can be found in standard references

The Pandora software development kit for pattern recognition

The development of automated solutions to pattern recognition problems is important in many areas of scientific research and human endeavour. This paper describes the implementation of the Pandora Software Development Kit, which aids the process of designing, implementing and running pattern recognition algorithms. The Pandora Application Programming Interfaces ensure simple specification of the building-blocks defining a pattern recognition problem. The logic required to solve the problem is implemented in algorithms. The algorithms request operations to create or modify data structures and the operations are performed by the Pandora framework. This design promotes an approach using many decoupled algorithms, each addressing specific topologies. Details of algorithms addressing two pattern recognition problems in High Energy Physics are presented: reconstruction of events at a high-energy e+e- linear collider and reconstruction of cosmic ray or neutrino events in a liquid argon time projection chamber.This work was funded in part by the UK Science and Technology Facilities Council and by the European Union under the Advanced European Infrastructures for Detectors and Accelerators (AIDA) project.This is the final version of the article. It first appeared from Springer via http://dx.doi.org/10.1140/epjc/s10052-015-3659-

Modelling rates of gasification of a char particle in chemical looping combustion

Rates of gasification of lignite char were compared when gasification with CO2 was undertaken in a fluidised bed of either (i) an active Fe-based oxygen carrier used for chemical looping or (ii) inert sand. The kinetics of the gasification were found to be significantly faster in the presence of the oxygen carrier, especially at temperatures above 1123 K. An analytical solution assuming pseudo-binary diffusion of species was developed to account for external and internal mass transfer and for the effect of the looping agent. The model also included the effects of the evolution of the pore structure at different conversions. The results are compared with a full numerical model using the Stefan-Maxwell equations. Excellent agreement was observed between the rates predicted by the two models and those observed experimentally at T ≤ 1123 K. At 1173 K, the pseudo-binary model predicted slightly higher rates than the full numerical solution. It was found that a significant share of the error of the predicted rates with the analytical solution was caused by an underestimation of intraparticle diffusional resistance rather than by assuming a pseudo-binary system external to the particle. Both models suggested that the presence of Fe2O3 led to an increase in the rate of gasification because of the rapid oxidation of CO by the oxygen carrier to CO2. This resulted in the removal of CO and maintained a higher mole fraction of CO2 in the mixture of gas around the particle of char, i.e. within the mass transfer boundary layer surrounding the particle. This effect was most prominent at ~20% conversion when (i) the surface area for reaction was a maximum and (ii) because of the accompanying increase in porosity, intraparticle resistance to gas mass transfer within the particle of char had fallen, compared with that in the initial particle.EPSRCThis is the author accepted manuscript. The final version is now available at http://www.sciencedirect.com/science/article/pii/S1540748914003150

Effects of two different hip-knee-ankle-foot orthoses on postural stability in subjects with spinal cord injury : a pilot study

Purpose Evaluation of two different hip-knee-ankle-foot orthoses (HKAFOs; medial linkage reciprocating gait orthosis [MLRGO] and isocentric reciprocating gait orthosis [IRGO]) using gait and postural stability analysis in four subjects with spinal cord injury (SCI). Overview of Literature To the best of our knowledge, no study has evaluated postural stability in subjects with SCI when using MLRGO and IRGO. Methods The relative efficacy of each orthosis was evaluated with relevant gait parameters, and an assessment of postural stability and sway during usage was made. Each analysis was conducted following an appropriate period of training and acclimatization. The gait parameters employed in the study were walking speed, cadence, and endurance; these were recorded and analyzed using current, validated methods. Postural stability was assessed using a verified force plate measurement system, and a modified Falls Efficacy Scale (mFES) was used for the measurement of postural sway and the perceived fear of falling. Results Walking speed, cadence, and endurance increased with the use of both HKAFOs. When the two types of HKAFOs were compared, all the parameters showed a slight (but not significant) increase with the use of MLRGO compared with the use of IRGO. In contrast, there were slight but insignificant improvements in postural sway with the use of IRGO. However, although there were no significant differences between the two sets of mFES scores, there was a slightly reduced fear of falling with the use of MLRGO compared with the use of IRGO in the static standing position. Conclusions It is noteworthy that meaningful interpretations of results can only be drawn if a larger sample is employed. This pilot study showed no significant data; however, the results indicate that the use of MLRGO is superior to that of IRGO in terms of potential improvement in the mobility and confidence levels of subjects with SCI

Potential for adaptation in response to thermal stress in an intertidal macroalga

Understanding responses of marine algae to changing ocean temperatures requires knowledge of the impacts of elevated temperatures and the likelihood of adaptation to thermal stress. The potential for rapid evolution of thermal tolerance is dependent on the levels of heritable genetic variation in response to thermal stress within a population. Here, we use a quantitative genetic breeding design to establish whether there is a heritable variation in thermal sensitivity in two populations of a habitat-forming intertidal macroalga, Hormosira banksii (Turner) Descaisne. Gametes from multiple parents were mixed and growth and photosynthetic performance were measured in the resulting embryos, which were incubated under control and elevated temperature (20°C and 28°C). Embryo growth was reduced at 28°C, but significant interactions between male genotype and temperature in one population indicated the presence of genetic variation in thermal sensitivity. Selection for more tolerant genotypes thus has the ability to result in the evolution of increased thermal tolerance. Furthermore, genetic correlations between embryos grown in the two temperatures were positive, indicating that those genotypes that performed well in elevated temperature also performed well in control temperature. Chlorophyll a fluorescence measurements showed a marked decrease in maximum quantum yield of photosystem II (PSII) under elevated temperature. There was an increase in the proportion of energy directed to photoinhibition (nonregulated nonphotochemical quenching) and a concomitant decrease in energy used to drive photochemistry and xanthophyll cycling (regulated nonphotochemical quenching). However, PSII performance between genotypes was similar, suggesting that thermal sensitivity is related to processes other than photosynthesis. © 2013 Phycological Society of America

Perinatal changes in fetal ventricular geometry, myocardial performance and cardiac function in normal term pregnancies.

Background: The fetal heart at term is exposed to an increase in hemodynamic work as a consequence of fetal growth, increased circulating volume and alteration in loading patterns due to maturational changes in fetoplacental circulation. The extent to which these cardiovascular changes influence the human fetal and neonatal cardiac adaptation has not been fully elucidated. The aim of this study was to evaluate perinatal cardiovascular changes in ventricular geometry and myocardial performance in normal term fetuses. Methods: Prospective study of 108 uncomplicated pregnancies delivering at term. M-mode, twodimensional (2D) or B-mode, pulsed wave (PW) Doppler, PW tissue Doppler and 2D speckle tracking imaging were performed a few days before, and within 24 hours of birth. Results: Analysis of paired fetal and neonatal echoes demonstrated significant perinatal changes (p<0.0001 for all) in right ventricular (RV) and left ventricular (LV) geometry (RV/LV enddiastolic dimension ratio: 1.2 vs. 0.8, RV sphericity index: 0.53 vs. 0.40, LV sphericity index: 0.46 vs. 0.49). There were corresponding significant (p<0.001 for all) perinatal changes in global myocardial performance: LV myocardial performance index (MPI’): 0.60 vs. 0.47, RV MPI’: 0.61 vs. 0.42; systolic function: LV longitudinal systolic strain rate: -1.4 /s vs. -1.0 /s, RV longitudinal systolic strain rate: -1.5 /s vs. -1.0 /s; RV systolic annular peak velocity (S’): 5.3 cm/s vs. 6.5 cm/s; and diastolic function: LV diastolic annular peak velocity ratio (E’/A’): 0.8 vs.1.1. Conclusion: The findings support the concept that the perinatal period is associated with major changes in fetal ventricular geometry and cardiac function in response to significant alterations in loading conditions. Improved knowledge of perinatal cardiac changes in normal fetuses could facilitate better understanding of cardiac adaptation in normal and pathological pregnancies

Sensitivity of chemical-looping combustion to particle reaction kinetics

A simple simulation for chemical-looping combustion (CLC) is discussed: two, coupled fluidised reactors with steady circulation of particles of oxygen carrier between them. In particular, the sensitivity of CLC to different particle kinetics is investigated. The results show that the system is relatively insensitive to different kinetics when the mean residence time of particles in each reactor is greater than the time taken for them to react completely.This is the final published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0009250916302779