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Abiotic stress factors can be detected using visible and near-infrared spectral signatures. Previous work demonstrated the potential of this technology in crop monitoring, although a large majority used vegetation indices, which did not consider the complete spectral information. This work explored the capabilities of spectral information for abiotic stress detection using supervised machine learning techniques such as support vector machine (SVM), random forest (RF), and neural network (NN). This study used avocados grown under various water treatments, maize submitted to nitrogen deficiency, and common beans under phosphorous restriction. The spectral characterization of the crops subjected to abiotic stress was studied on the visible to near-infrared (450 to 900 nm) spectrum, identifying discriminative bands and spectral ranges. Then, the advantages of using an integrated approach based on machine learning to detect abiotic stress in crops were demonstrated. Instead of relying on vegetation indices, the proposed approach used several spectral features obtained by analyzing the discriminative signature shape, applying a spectral subset band selection algorithm based on similarity, and using the minimum redundancy maximum relevance (MRMR), F-test and chi-square test ranks for feature selection. The results showed that supervised classifiers applied to the spectral features outperform the accuracies obtained from vegetation indices. The best common bean results were obtained using SVM with accuracies up to 91%; for maize and avocado, NN obtained 90% and 82%, respectively. It is noted that detection accuracy depends on various factors, such as crop type, genotype, and level of stress. [ABSTRACT FROM AUTHOR]

Interior permanent magnet (IPM) motors in traction applications often employ discrete rotor skewing constructions to reduce torsional excitations and back-EMF harmonics. Although skewing is very effective in reducing cogging torque, the impact on torque ripple is not well understood and can vary significantly over the operating envelope of a motor. Skewing also leads to the creation of a non-zero axial force that may compromise the bearing life if not considered. This paper introduces a holistic methodology for analyzing the effect of skewing, aiming to minimize torsional excitations, axial forces and back-EMF harmonics whilst mitigating the impact on performance and costs. Firstly, analytical models are employed for calculating cogging torque, torque ripple and axial forces. Then, 2D and 3D finite element analysis are used to incorporate the influence of non-linear material behavior. A detailed structural model of the powertrain is employed to calculate the radiated noise and identify key areas allowing a motor designer to reduce noise, vibration and harshness (NVH). A meticulous selection process for the skewing angle, the number of skew stacks and the orientation of skew stacks is developed, giving particular attention to the effect of the selected pattern on NVH in both forward and reverse rotating directions. [ABSTRACT FROM AUTHOR]

Clay soils frequently develop large cracks after irrigation. Infiltration equations therefore need to be modified to take cracking soil properties into account when modeling and optimizing furrow irrigation, In this article, we propose an infiltration equation for cracked soils, based on two parameters, Other parameters of the global model are assumed to be known (furrow length, shape, slope, and estimated roughness). One parameter is linked to the type of soil and is calibrated separately for the entire irrigation process. The second parameter takes soils' cracks into account and is calibrated in real time during the advance phase (before the water front overruns the middle of the plot). This global furrow irrigation model for cracked soils is derived from a conceptual approach and can be used either to predict in real time, water-use efficiency during irrigation (infiltrated volume, runoff water losses, uniformity) or to optimize irrigation parameters (head flow, irrigation duration). The model was tested and validated on three irrigation applications on 60 furrows in a corn field in Tarascon in southeastern France. This conceptual model can be easily adapted to the statistical approach, which is based on the variability of water advance between the furrows.

Abstract Background To ensure the highest efficiency, health services should be provided with the least possible complexity. The aim of this study is to quantify the degree of appropriateness in preoperatory hospital stays and to analyse those factors associated with a greater inappropriate use. Methods Historical cohort study. The histories of 440 hospitalised patients who underwent at least one surgical procedure were analysed. Data collection was carried out by doctors not involved in the services studied, following the Appropriateness Evaluation Protocol. A bivariate and multivariate analysis of the factors associated with the appropriateness of preoperatory stays was carried out. Results The mean number of days of preoperatory stay was 5.5 (SD 5.11), of which a mean number of 2.5 days were considered to be inappropriate (SD 4.11). The overall rate of inappropriateness was 45.2% (CI 95% 43.3–47.1). The multivariate analysis showed a positive association of the inappropriateness of the preoperatory stay with weekend days, programmed admission, hospital stays longer than 7 days, medical records incorrectly or incompletely documented and the age groups of 45–65 and the >65 with respect to the Conclusion The inappropriate use of hospital stay during preoperatory care affects almost half the period and there are some risk determinants that could act as indicators at admission. In addition, the efficiency of care provision was found to vary greatly from the point of view of its appropriateness.

Parasites of the genus Leishmania, etiological agents of Leishmaniasis, have been extensively studied due to the wide spectrum of clinical manifestations that they generate in humans, the impact of the disease in affected populations and the low availability of treatments. Most of the studies on this parasite, in both promastigote and amastigote stages, have been developed using cultures of the parasite kept in vitro by long time. Leishmania spp. presents a high genetic plasticity, due to variations at chromosomal level (rearrangements, aneuploidy, etc.) or in specific regions such as genes (copy number variation). This genomic mosaicism in Leishmania spp. can act as an essential adaptive mechanism that allows rapid selection of a particular genome structure under specific conditions. This plasticity means that the in vitro maintenance of parasite isolates can induce genotypic and eventually phenotypic alterations such as loss of virulence and infectivity. In this sense, this study presents an analysis of the genomic and phenotypic variation in vitro growth of promastigotes and [in vitro susceptibility to Amphotericin B (AmB) in promastigotes and amastigotes], resulting from the in vitro maintenance of promastigote stages of a clinical isolate of L. (V). braziliensis. Here we perform a comparison of the same parasite isolate between few culture passages after parasite isolation from patient (<10, early) vs multiple culture passages (>20, late). Phenotypic characterization data show that the in vitro doubling time during the logarithmic phase was 9.2 h (95% CI, 8.283 to 10.31) for the early isolate and 8.3 h (95% CI, 7.769 to 8.887) for the late version. Susceptibility to AmB determined from the IC50, was 0.101 μg/mL (95% CI, 0.09063 to 0.1129) for the early version and 0.057 μg/mL (95% CI, 0.05200 to 0.06357) for the late version with a significant difference between them (F-Test, p<0.0001). Regarding genomic analysis, a significant variation in the number of copies of different gene families was observed. Within the genes with known IDs, a loss in 484 gene families and a gain of 291 gene families were observed for late version with respect to early one. When comparing with the reference genome, a certain degree of similarity between losses and gains resulting from in vitro selection was observed. To understand the biological processes associated with the expansion/contraction in gene copy number, a gene ontology (GO) enrichment analysis was carried out, showing that gene losses resulting from in vitro growth were mainly associated with long-chain fatty acid metabolism, tryptophan catabolism and glycolysis. Gene gains are mainly associated with microtubule movements, vesicular localization and response to oxidative stress. The results obtained suggest that the in vitro maintenance of L. (V.) braziliensis isolates leads to important variations with respect to the natural genotype and phenotype. [ABSTRACT FROM AUTHOR]