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

How people with advanced cancer manage changing eating habits

Aim. This paper is a report of a study to explore the management of changing eating habits in people with advanced cancer.Background. Internationally there is interest in supporting self-management as a way of helping people to live with illness. It is unknown if promoting self-management in people with cancer can lead to beneficial health outcomes. In order to develop and test interventions that promote self-management in cancer patients, it is first important to understand ways in which they can help themselves.Method. A mixed-methods exploratory case study of the meaning, management and manifestations of weight loss and change in eating habits was conducted with 30 patients receiving palliative home care in England in 2003. Semi-structured interview data were analysed using both content and thematic approaches.Findings. Participants described a total of 141 different self-actions, each of which formed a component of up to four self-action strategies that were used to aid life with advanced cancer. The strategies were ‘Taking control’, ‘Promoting self-worth’, ‘Relationship work’, and ‘Distraction’. Employing these strategies led to changes in thinking and behaviour that were motivated by a desire to sustain or enhance well-being. The pattern of self-action strategies adopted by each individual is theorized to be dependent on the personal and contextual resources available.Conclusion. Patients can and do find their own solutions to eating problems and nurses should support this self-action. The proposed theory of self-management of eating change provides an understanding that can inform the provision of this support.<br/