58 research outputs found

    Perceived impacts of a pilot agricultural livelihood and microfinance intervention on agricultural practices, food security and nutrition for Kenyans living with HIV

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    Introduction Agriculture is the primary source of income and household food for >75% of rural Kenyans, including people living with HIV (PLHIV), making agricultural yields an important factor in food security and nutrition. Previous studies have shown the interconnectedness of food insecurity, malnutrition, and poor HIV health by elucidating that having one of these conditions increases the likelihood and severity of having another. However, few studies have explored the linkages between agricultural practices, food security and nutrition for PLHIV, or how agricultural livelihood interventions may affect these domains. This study aimed to examine the mechanisms through which an agricultural livelihood intervention can positively or negatively affect agricultural practices, food security, and nutrition for PLHIV. Methods From July 2012-August 2013, we interviewed participants with HIV on antiretroviral therapy (ART) enrolled in a pilot randomized controlled trial (RCT) of an agricultural livelihood and finance intervention to understand the mechanisms through which the intervention may have affected HIV health outcomes. The intervention included agricultural and finance training and a microfinance loan to purchase the MoneyMaker hip pump, a human-powered water pump, seeds, and other farming implements. A purposive sample of 45 intervention and a random subset of 9 control participants were interviewed at 12-month endline visit with a subset of 31 intervention participants interviewed longitudinally at both the 3- and 12-month visits. Transcripts were double coded using an inductive-deductive approach and analyzed for impacts of the intervention on agricultural practices, food security, and nutrition using analytic reports for each key theme. Results All intervention participants described improvements in agricultural practices and yields attributed to the intervention while many also described improvements in income; these changes in turn contributed to improved HIV health, including suppressed viral loads, and a few people noted improved immunologic parameters. Key mechanisms included the knowledge gained from agricultural training which led to improved yields and access to new markets. The use of the irrigation pump was also identified as an additional, lesser important mechanism. All intervention participants reported sustained improvements in food security and nutrition through increased yields and income from the sale of excess crops used to purchase food, and diversification of fresh fruits and vegetables consumed through agricultural production. This led to self-reported weight gain which was a nutritional mechanism towards improved health. Conclusions Agricultural and finance interventions that improve farming practices could lead to improved health outcomes through the pathways of improved food security, income, and diversified diet. The results from this study helped the team to enhance the intervention prior to implementation of the larger cluster RCT (cRCT). By understanding how agricultural livelihood interventions act upon pathways towards improved health, policy options can be developed and implemented to include components that are needed to achieve sustainable outcomes

    Highly-parallelized simulation of a pixelated LArTPC on a GPU

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    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

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    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
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