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

The DUNE far detector vertical drift technology. Technical design report

DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals

The effect of menopause on bone mineral density and bone-related biochemical variables in Indonesian women

The definitive version is available at www.blackwell-synergy.comObjective To determine the effects of menopause on bone-related variables in Indonesian women and to compare them with corresponding data in Caucasian Australian women. Design A study of bone-related variables in women aged 45–55 years in Jakarta compared with corresponding historical data from Caucasian Australian women. Measurements Dietary intakes, bone mineral density (BMD) and calcium-related variables in blood and urine. Results Dietary calcium, phosphorus and protein intakes were significantly lower in the women from Jakarta than in those from Adelaide (all P < 0·001), probably because of lower milk consumption, but energy intake was similar in the two cities. Indonesian women were shorter and lighter than Australian women (P < 0·001) but had a comparable body mass index (BMI). The Indonesians also had a lower spinal BMD than the Australians but this was accounted for by the differences in height and weight between the two populations. The differences in serum and urinary calcium and phosphate and serum alkaline phosphatase across the menopause were comparable in Indonesian and Australian women but creatinine excretion was 25% lower in Jakarta than in Adelaide (P < 0·001) and this was probably sufficient to account for higher ratios of some urinary solutes to urinary creatinine in the Indonesians. Serum 25-hydroxyvitamin D (25OHD) levels were significantly lower (P < 0·001) and serum PTH levels significantly higher (P = 0·0045) in Jakarta than in Adelaide. Conclusions The differences in bone-related biochemical variables across the menopause were similar in the two populations, but calcium and protein intake and urine creatinine were lower in Indonesian than in Australian women. Serum 25OHD was lower and PTH higher in the Indonesian women, probably because of their darker skin, their practice of avoiding direct sunlight and the heavy atmospheric pollution in Jakarta.Maryantoro Oemardi, Michael Horowitz, Judith M. Wishart, Howard A. Morris, Allan G. Need, Peter D. O'Loughlin and B. E. Christopher Nordi

Bone density and bone-related biochemical variables in normal men: a longitudinal study

Background. The objective of this study was to determine the pattern of forearm bone loss and its relationship to markers of bone turnover and sex steroids in normal men. This was a longitudinal study over a median interval of 41 months. The study was conducted in Adelaide, Australia. Study participants were 123 healthy male subjects, between the ages of 20 and 83 years. Methods. Fat-corrected forearm bone mineral content (fcBMC), markers of bone formation (alkaline phosphatase, osteocalcin, procollagen type 1 C-terminal extension peptide) and bone resorption (collagen type I cross-linked telopeptide, hydroxyproline/creatinine, pyridinoline/creatinine, and deoxypyridinoline/creatinine), calculated serum bioavailable testosterone, and serum estradiol were measured. Results. The mean time-weighted rate of change in forearm fcBMC was −0.33% ± 0.72 (SD) per year. Bone loss commenced after 30 years of age and increased with age (p < .001), particularly after age 70 years. There was no relationship between the rate of change in fcBMC and either markers of bone turnover or serum sex steroids. Conclusions. In normal men, bone loss increases with age; there does not appear to be any relationship between this loss and either markers of bone turnover or levels of free androgen or estrogen.F. Scopacasa, J.M. Wishart, A.G. Need, M. Horowitz, H.A. Morris and B.E.C. Nordi