Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Relationship between illness representation and self-efficacy

Aim.  This paper reports a patient survey exploring the possible relationship between illness perception and self-efficacy following a cardiac event, and the implications this could have for nursing practice. Background.  Cardiac rehabilitation guidelines endorse the need to improve psychological care; suggesting that individualized support will improve the effectiveness of cardiac rehabilitation. Surveys, however, continue to identify that psychosocial factors are poorly assessed. Illness representation and self-efficacy are two prominent research approaches that have been developed as separate foci for the treatment of patients. Method.  A cross-sectional survey with patients diagnosed with either myocardial infarction or angina over an 8-month period in two hospitals. The Illness Perception Questionnaire, General Self-Efficacy Questionnaire, Cardiac Diet Self-efficacy Instrument and Cardiac Exercise Self-efficacy Instrument were used, alongside two specifically-designed scales: the Diet Outcome Expectation and Exercise Outcome Expectation Scales. Results.  The results indicate that there is a significant relationship between illness perception and self-efficacy. The greater patients’ perceived consequences of the heart condition, the lower was the general self-efficacy available to cope with the condition. Further, the longer the perceived time the condition will affect the patient, the higher the specific self-efficacy to maintain a change of diet or exercise regime. Conclusion.  The findings identify that, in the initial phase of recovery, nursing practice needs to focus on the key variables of ‘consequence’ and ‘timeline’ in order to increase patients’ confidence in their ability to cope (self-efficacy)