Simulated Productivity Lost by Erosion (SimPLE): model development, validation, and use

Non-Peer ReviewedProductivity lost due to soil erosion can be estimated by existing computer simulation models such as EPIC, NTRM and CENTURY. However, these models require extensive input data and, to date, have had limited success in simulating Western Canadian conditions. The objective of this study was to develop a simple spring wheat model which captured the essential relationships between topsoil erosion and productivity loss in Chemozemic soils. Key relationships in our model describe: (i) how plants create yield from water, N, and P; (ii) how the soil provides these nutrients, and (iii) how erosion impacts on the supply of each nutrient. These relationships were logically connected using the Stella® II modeling environment. Agreement was highly significant (r = 0.55***) between predicted and observed grain yields over 75 site years at Indian Head, Saskatchewan. Also, grain yields from scalped Chemozemic soils in Alberta were closely simulated (r = 0.86****) by SimPLE. Fifty representative soil profiles from the Brown, Dark Brown and Black soil zones were eroded in SimPLE to numerically describe the production lost under wet, normal, and dry scenarios, with and without optimum fertilizer. Yield loss, as a percentage of non-eroded yield, increased with increasing soil erosion following a trend very similar to that reported in field studies. SimPLE is flexible and can be used for analysis of "what if' management scenarios or calculating soil loss tolerance (T) values

Developing simplified synergistic relationships to model topsoil erosion and crop yield

Non-Peer ReviewedTopsoil is highly enriched with organic matter, which provides a valuable source of plant nutrients as well as a favorable rooting environment. Over time, erosion processes selectively remove the organic matter-rich fine fraction which causes a measurable reduction in soil productivity. Assessments of past erosion are of little value in predicting future losses in productivity since the synergistic lowering of soil organic matter through lower residue inputs is not considered. Dynamic computer models, which simulate the plant/soil system, can project the long run future costs of soil erosion on crop yield. A simplified erosion-crop yield model was developed by first defining the most important soil productivity variables, then quantifying the effect of erosion on each variable. The model predicted a declining trend in grain yields similar to that observed on soil scalping experiments

Modulation control and spectral shaping of optical fiber supercontinuum generation in the picosecond regime

Numerical simulations are used to study how fiber supercontinuum generation seeded by picosecond pulses can be actively controlled through the use of input pulse modulation. By carrying out multiple simulations in the presence of noise, we show how tailored supercontinuum Spectra with increased bandwidth and improved stability can be generated using an input envelope modulation of appropriate frequency and depth. The results are discussed in terms of the non-linear propagation dynamics and pump depletion.Comment: Aspects of this work were presented in Paper ThJ2 at OECC/ACOFT 2008, Sydney Australia 7-10 July (2008). Journal paper submitted for publication 30 July 200

Outsourcing von Personalfunktionen: Eine (erneute) Bestandsaufnahme

Das Personalmanagement befindet sich im Umbruch, da immer mehr Unternehmen dazu übergehen, ihre Personalfunktionen an professionelle Dienstleister auszulagern. Der vorliegende Beitrag untersucht auf Basis einer durchgeführten schriftlichen Befragung von 45 deutschen Unternehmen deren Outsourcingverhalten hinsichtlich ihrer Personalfunktionen. Im Ergebnis wird gezeigt, dass bereits eine Vielzahl von Unternehmen einzelne Personalfunktionen auslagern und die Unternehmen zum großen Teil auch bereit sind, über die bisher ausgelagerten Bereiche hinauszugehen und noch weitere Personalfunktionen auszulagern. Im Vergleich zu anderen Studien ist auffällig, dass Unternehmen sich von einer reinen (transaktions-)kostentheoretischen Betrachtung der Outsourcingentscheidung lösen und verstärkt ressourcenorientierte Überlegungen in ihr Kalkül einbeziehen. Daher werden in diesem Beitrag sowohl Transaktionskostentheorie als auch Ressourcenansatz als theoretisches Fundament zugrunde gelegt.Based on a survey among 45 leading German companies, this paper analyses their outsourcing activities in the human resources management function. This paper reports that a lot of HR activities have already been outsourced and that companies are willing to extend outsourcing to further HR activities. This study shows that companies do not rely only on transaction cost theory, but increasingly also on resource-based analyses to make their outsourcing decisions

The effects of different doses of caffeine on performance, rating of perceived exertion and pain perception in teenagers female karate athletes

ABSTRACT The present study set to examine the effects of different doses of caffeine on performance, rating of perceived exertion (RPE), and pain perception in female teenager athletes of karate. Ten female karate athletes (16.8±1.23 years; height 1.59±0.28 m; body-mass 57.73±8.33 kg; BMI 22.71±3.05 kg/m2) participated in the study. A double-blind, randomized, and crossover counterbalanced design was used. In three sessions (with an interval of seven days'), ten female karate athletes ingested low dose (2 mg/kg), moderate dose (5 mg/kg) caffeine, and placebo. Sixty minutes after consumption, they performed the tests as below: one repetition maximum and 60% of one repetition maximum in the leg press, explosive power test, and anaerobic RAST test. After the tests, the participants' RPE (6-20 scale) and pain perception (0-10 scale) were recorded using various categorical scales. The results showed that caffeine ingestion at moderate dose significantly reduced RPE and pain perception values compared with the placebo during muscular endurance test (P=0.0001 and P=0.039, respectively). The findings suggest that caffeine dose of 5 mg/kg body mass appears to improve RPE and pain perception in female teenager athletes of karate. The dose of 2 mg/kg body mass does not confer any additional improvement in performance

Identification and reconstruction of low-energy electrons in the ProtoDUNE-SP detector

International audienceMeasurements of electrons from νe interactions are crucial for the Deep Underground Neutrino Experiment (DUNE) neutrino oscillation program, as well as searches for physics beyond the standard model, supernova neutrino detection, and solar neutrino measurements. This article describes the selection and reconstruction of low-energy (Michel) electrons in the ProtoDUNE-SP detector. ProtoDUNE-SP is one of the prototypes for the DUNE far detector, built and operated at CERN as a charged particle test beam experiment. A sample of low-energy electrons produced by the decay of cosmic muons is selected with a purity of 95%. This sample is used to calibrate the low-energy electron energy scale with two techniques. An electron energy calibration based on a cosmic ray muon sample uses calibration constants derived from measured and simulated cosmic ray muon events. Another calibration technique makes use of the theoretically well-understood Michel electron energy spectrum to convert reconstructed charge to electron energy. In addition, the effects of detector response to low-energy electron energy scale and its resolution including readout electronics threshold effects are quantified. Finally, the relation between the theoretical and reconstructed low-energy electron energy spectrum is derived and the energy resolution is characterized. The low-energy electron selection presented here accounts for about 75% of the total electron deposited energy. After the addition of missing energy using a Monte Carlo simulation, the energy resolution improves from about 40% to 25% at 50 MeV. These results are used to validate the expected capabilities of the DUNE far detector to reconstruct low-energy electrons

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

Neutrino interaction vertex reconstruction in DUNE with Pandora deep learning

The Pandora Software Development Kit and algorithm libraries perform reconstruction of neutrino interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at the Deep Underground Neutrino Experiment, which will operate four large-scale liquid argon time projection chambers at the far detector site in South Dakota, producing high-resolution images of charged particles emerging from neutrino interactions. While these high-resolution images provide excellent opportunities for physics, the complex topologies require sophisticated pattern recognition capabilities to interpret signals from the detectors as physically meaningful objects that form the inputs to physics analyses. A critical component is the identification of the neutrino interaction vertex. Subsequent reconstruction algorithms use this location to identify the individual primary particles and ensure they each result in a separate reconstructed particle. A new vertex-finding procedure described in this article integrates a U-ResNet neural network performing hit-level classification into the multi-algorithm approach used by Pandora to identify the neutrino interaction vertex. The machine learning solution is seamlessly integrated into a chain of pattern-recognition algorithms. The technique substantially outperforms the previous BDT-based solution, with a more than 20% increase in the efficiency of sub-1 cm vertex reconstruction across all neutrino flavours

DUNE Phase II: scientific opportunities, detector concepts, technological solutions

The international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy toward the implementation of this leading-edge, large-scale science project. The 2023 report of the US Particle Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly endorsed DUNE Phase I and Phase II, as did the European Strategy for Particle Physics. While the construction of the DUNE Phase I is well underway, this White Paper focuses on DUNE Phase II planning. DUNE Phase-II consists of a third and fourth far detector (FD) module, an upgraded near detector complex, and an enhanced 2.1 MW beam. The fourth FD module is conceived as a "Module of Opportunity", aimed at expanding the physics opportunities, in addition to supporting the core DUNE science program, with more advanced technologies. This document highlights the increased science opportunities offered by the DUNE Phase II near and far detectors, including long-baseline neutrino oscillation physics, neutrino astrophysics, and physics beyond the standard model. It describes the DUNE Phase II near and far detector technologies and detector design concepts that are currently under consideration. A summary of key R&D goals and prototyping phases needed to realize the Phase II detector technical designs is also provided. DUNE's Phase II detectors, along with the increased beam power, will complete the full scope of DUNE, enabling a multi-decadal program of groundbreaking science with neutrinos