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

Aroma volatiles components of ‘Fuerte’ avocado (persea americana mill.) stored under different modified atmospheric conditions

Modified atmosphere (MA) storage have direct influence on biogenesis and releasing of aroma volatiles in the ripe fruits. A study was conducted to investigate the influence of MA storage on the volatile constituents of ripe avocados. Mature avocados (cv. Fuerte) were packed in four different packaging materials and the equilibrium gas composition developed within the packs were in perforated polyvinylchloride: SM-60 (Control: 20.8% O2 + 0.03% CO2), Micro-porous polypropylene: MY-15 (4.8% O2 + 8.4% CO2), Low density polyethylene: LPDE (7.7% O2 + 5.8% CO2) and Micro-porous polypropylene: MD-15 (9% O2 + 5.4% CO2). The MA packs of avocados were stored at 7°C for 4 weeks and were ripen at 20°C. The volatile compounds of ripe avocados were investigated by means of gas chromatography (GC) and GC-mass spectrometry. A total of 68 of components were identified among those butyl acetate, 3-hexenyl acetate, 2-hexenyl acetate and hexyl acetate were only detected from MA stored avocados. Therefore, the MA storage with suitable gas composition could be used as a novel technology to extend the shelf life without significantly (p > 0.05) affecting the volatile components of the avocados

Lessons learned from stock collapse and recovery of North Sea herring: a review

The collapse and recovery of North Sea herring in the latter half of the 20th century had both ecological and economic consequences. We review the effect of the collapse and investigate whether the increased understanding about the biology, ecology, and stock dynamics gained in the past three decades can aid management to prevent further collapses and improve projections of recovery. Recruitment adds the most uncertainty to estimates of future yield and the potential to reach biomass reference points within a specified time-frame. Stock–recruitment relationships must be viewed as being fluid and dependent on ecosystem change. Likewise, predation mortality changes over time. Management aimed at maximum sustainable yield (MSY) fishing mortality targets implies interannual variation in TACs, and variability in supply is therefore unavoidable. Harvest control rules, when adhered to, aid management greatly. We advocate that well-founded science can substantially contribute to management through improved confidence and increased transparency. At present, we cannot predict the effects of collapse or recovery of a single stock on the ecosystem as a whole. Moreover, as managers try to reconcile commitments to single-species MSY targets with the ecosystem-based approach, they must consider the appropriate management objectives for the North Sea ecosystem as a whole

Winds of Change: A Century of Agroclimate Research

Climate has been of primary concern from the beginning of agricultural research. Early in the 20th century, climatology and agronomy evolved separately, focusing primarily on production agriculture and crop adaptation. Concepts developed include thermal units and water use efficiency. The integrated discipline of agroclimatology developed in the mid-20th century. As theoretical understanding evolved, numerous papers related to agroclimatology were named Citation Classics. Spectral properties of plants and soils were identified that underpin today’s remote sensing technologies. Commercialization of instrumentation enhanced our ability to efficiently collect data using standardized methods. Private and public-sector partnerships advanced research capacity. Later in the 20th century, research focus shifted toward integrating knowledge into crop growth and agronomic models. Remote sensing provided capacity to gain theoretical and practical understanding of regional scale processes. In the early 21st century, recognition of earth as a system along with inter-related human systems is driving research and political agendas. There is a pressing need to change our data-rich to an information-rich environment. The emerging cyberinformatics field along with natural resource and agricultural system models allow us to apply climate information to assessments and decision support related to water supply, production, environmental management, and other issues. Solutions to today’s problems require interdisciplinary and multi-sectoral teams. While needs have never been greater, fewer universities maintain critical mass required to off er advance degrees in agroclimatology. It will be increasingly important that agrclimatology attract top students and provide training and practical experience in conducting integrated systems research, communications, and team skills