Utilizing Multispectral Time-Series Data for GWAS in Spring Wheat: A Comparison of Conventional and Machine-Learning Approaches

Plant breeding is the practice of breeding plants with desirable traits, for example, resistance to local pathogens, adaptation to environmental stressors, and increased yield. With the recent development of high-throughput phenotyping using remote sensing technologies and multispectral sensors, researchers can derive metrics (i.e., bands and vegetation indices) that correlate with important agronomic traits like yield and maturity time to study these traits in a high-throughput manner. There lies great potential in multispectral data for dissecting the genetic architecture of spring wheat (Triticum aestivum), and previous studies in a variety of crops (wheat, maize, and rice) have identified both known and novel genetic regions influencing agronomic traits. This thesis explored the integration of multispectral time-series with Genome-Wide Association Studies (GWAS) in spring wheat. Given that spectral time-series are not typically used in association studies, we also implemented a machine learning (ML) alternative based on genetic algorithms and support vector regression (GA-SVR) for comparison with conventional GWAS using mixed linear models (MLM). Both GWAS approaches were employed on agronomic traits data and spectral phenotypes derived from the multispectral time-series. Our results demonstrated that spectral phenotypes had moderate to large heritability, and correlated well with certain traits such as grain yield. We identified several spectral Quantitative Trait Loci (QTL) containing or near genes, like Rht-B1 and Vrn-A1, that overlapped with agronomic QTL related to the function of these genes. We also identified temporal genetic patterns, where certain spectral regions were significant only in specific time-periods (e.g., grain filling). In addition, the MLM detected few QTL associated with yield and protein content that overlap with spectral QTL. This suggests that the data or model may not be adequate for identifying spectral QTL related to complex physiological traits. On the other hand, the GA-SVR method produced a greater number of significant markers and QTL compared to MLM. It also found more spectral QTL overlapping with regions identified for yield and protein content, indicating GA-SVR may be suitable for capturing and dissecting more complex traits. However, results should be interpreted with care, as confounding variables were not accounted for in the GA-SVR pipeline. In conclusion, this thesis demonstrates the potential usefulness of multispectral time-series for GWAS, because we identified temporal differences in significant spectral QTL, as well as basic genes related to height and maturity time. The GA-SVR method provided an alternative to MLM, and it is interesting to see that it returns different genomic regions, indicating that it might be capturing different information compared to MLM, and thus potentially overcoming some of the weaknesses of MLM. However, the effects of confounding variables in the GA-SVR pipeline remains unknown and requires further investigation

Experimental and modelling studies on the phase behaviour of mutual solvents and their transport through porous media in oil/brine/mutual solvent systems in the context of scale inhibitor squeeze treatments

Oilfield scale is a significant problem in oil production which arises due to temperature and pressure changes and mixing of incompatible brines when a well is produced. The most successful and commonly used strategy for mitigating against oilfield scale is the application of scale inhibitor squeeze treatments. A squeeze treatment is applied to the production well, and involves several stages, which are: pre-flush, main treatment, overflush, shut-in and back-production. During a treatment, a scale inhibitor adsorbs or precipitates into the formation, and its desorption/dissolution into the produced water when the well is put back into production prevents scale formation. A well must be re-squeezed before the scale inhibitor concentration in the produced water falls below the minimum inhibition concentration (MIC) required to prevent scaling. This work focuses on the pre-flush stage of a squeeze treatment, in which mutual solvents are applied in order to prepare the well for a treatment. This is the least investigated aspect of squeeze treatments, and the one with the greatest opportunity for potential optimisation. Fundamental to understanding how to best apply mutual solvents (MS) in squeeze treatments, to achieve squeeze lifetime enhancements and to mitigate any formation damage risks, is understanding MS phase behaviour, the transport of MS through the porous medium and MS/mineral surface conditioning effects (e.g. wetting changes). In this work, the phase behaviour of various mutual solvents is investigated in oil/brine/mutual solvent systems. Effects of salinity and chemistry are determined at field relevant conditions. The influence of scale inhibitors on phase behaviour is also investigated and mutual solvent blend design is examined. The work also develops a quantitative understanding of the phase behaviour of mutual solvents and employs that in the development of semi-empirical and thermodynamic models for describing the phase behaviour. Practical analytical tools are also developed to aid mutual solvent investigations as well as analysis in the presence of mutual solvents. Transport studies of MS in sand packs are used to investigate the transport of mutual solvents in single and multiphase systems. Numerous field solutions can be obtained from this work, but more importantly, this work enables and forms the basis for future mutual solvent investigations in the context of scale inhibitor squeeze treatment

Prognostic implications of ischemic mitral regurgitation following non-ST-Segment elevation acute myocardial infarction

Introduction: Ischemic mitral regurgitation (MR) is a common complication of acute myocardial infarction and has a negative impact on prognosis. However, few studies have been carried out on MR after non-ST-segment elevation acute myocardial infarction (NSTEMI).Aim: Investigate the clinical predictors of ischemic MR and its impact on the outcome after 1st NSTEMI .Methods: 40 consecutive patients were selected retrospectively after a first NSTEMI. Each underwent echocardiography and coronary angiography during their hospital admission. Patients were divided into two groups according to the presence or absence of MR at echocardiography: Group I  : 20 patients without MR , Group II : 20 patients with MR. The patients were followed up clinically for at least one year. The incidence of readmission for heart failure, unstable angina, reinfarction, or all combined (i.e, major adverse cardiac event [MACE]) was recorded.Results: The patients’ mean age was 59.62 ± 10.97 years and 67.5 % were male. They were followed–up for a  median of 640.5 days . No significant differences between both groups regarding baseline data ,cardiac isoenzymes , or revascularization (P > 0.05) , but there was significantly increased number of diseased coronary arteries in MR group (P  0.04). LA diameter was significantly increased with decreased LVEF% and increased wall motion abnormalities in MR group ((P < 0.05) . During follow-up period ,more admissions for unstable angina were seen in patients with MR but with little significance (P  0.05) . Regarding MACE, a greater incidence was found in the MR group (P<.05). Using Kaplan-Meier curves ,a long-term association of MACE with the presence of MR was found (P 0.04), and a higher grades of MR were associated with poor prognosis (P .05) . In conclusion: Ischemic MR yield poor prognosis. Thus, current MR should be carefully assessed after an NSTEMI,and probably requires even more meticulous treatment including early revascularization and stricter follow-up than usual

RETRACTED : Composite parameters analysis with boundary element method

This article has been retracted at the request of the Editors-in-Chief, according to the Publication Ethics Policy and Publication Malpractice Statement.Please see: http://revue.ummto.dz/index.php/JMES/about/editorialPolicies#custom-2 This note is published, 26 June 202

Performance of Two Geosynthetics-Lined Landfills in the Northridge Earthquake

Analyses of the performance of the Chiquita Canyon and Lopez Canyon landfills in the 1994 Magnitude 6.7 Northridge earthquake illustrate deficiencies in the current state-of-practice for seismic design of geosynthetic liner systems and the promise of a new state-of-the-art method for performance-based design, and suggest necessary modifications to construction quality assurance procedures for geosynthetic liner systems. Analyses of the Chiquita Canyon landfill case history using the conventional state-of-practice Newmark Analysis approach fail to predict the tears observed at the landfill following the earthquake in the side slope liner geomembrane at two different locations. However, the state-of-the-art finite difference based method does predict failure of the geomembrane at these locations if strain concentrations due to seams and scratches in the geomembrane from patches at locations where destructive samples were recovered for construction quality assurance purposes are considered. The state-of-the-art method also predicts tension strains observed in the filter geotextile for the side slope liner at the Lopez Canyon landfill following the earthquake. The analysis for the Chiquita Canyon landfill suggests that construction quality assurance guidelines for obtaining geomembrane samples for destructive testing should be developed for avoiding critical areas where geomembrane tensile strain is likely to accumulate

Nonlinear Time-Domain Analysis of a Sliding Block on a Plane

A time domain finite difference numerical model of a sliding rigid block on a plane is developed using a simple elastic-perfectly plas-tic Mohr-Coulomb interface model. The model is shown to accurately predict the slip-stick and slip-slip behavior deduced from an analytical solution for behavior of a sliding block on a horizontal plane and the results of physical model tests of a block on both hori-zontal and inclined planes subject to harmonic and non-uniform excitation provided the appropriate interface strength is employed. Back analyses of the physical model tests show that for some geosynthetic interfaces, the interface shear strength depends upon the velocity of sliding. The numerical model developed herein provides a basis for rigorous evaluation of several important problems in geotechnical earthquake engineering, including the cumulative permanent seismic deformation of landfills, embankments, slopes, and retaining walls and the stresses induced by seismic loading in geosynthetic elements of landfill liner and cover systems

Caractérisation physique des matériaux poreux par une méthode de type Boltzmann sur Réseau

International audienceUn code numérique, fondé sur la technique de résolution numérique Boltzmann sur Réseau (BR), d'estimation de propriétés physiques des matériaux poreux à partir d'images en coupe, obtenues en Microscopie Electronique à Balayage (MEB) est présenté. Les premiers résultats de cette technique testée sur des configurations bidimensionnelles montrent l'aptitude de la méthode à simuler avec une bonne précision les phénomènes de transfert de chaleur et de masse. L'étude numérique est étendue à l'estimation des paramètres physiques caractéristiques des matériaux poreux

Les déterminants des IDE : une revue de littérature.

Au cours des années 80 et 90, les Investissements Directs Etrangers ont été considérés comme étant un facteur de dominance des firmes multinationales dans les pays en voie de développement, or aujourd’hui ils sont considérés comme étant un moyen de développement économique et social dans les pays d’accueil. De ce fait, des efforts sont déployés par les pays en voie de développement pour attirer davantage d’investissements, et plusieurs projets de réformes ont été lancés. Il est à noter que la littérature sur les déterminants des Investissements Directs Etrangers est diversifiée et dénombre plusieurs facteurs qui tentent d’expliquer la décision de l’Investissement Direct Etranger, mais on peut observer que les résultats ne sont pas toujoursconsensuels. Notre travail a pour objectif de dresser une revue de la littérature ayant traité les déterminants des Investissements Directs Etrangers. Cette revue de littérature regroupe à la fois les déterminants des Investissements Directs Etrangers de nature théorique qu’empirique

Образ міста у “Вступній новелі” та “Арабесках” М. Хвильового

Стаття присвячена аналізу образу міста у “Вступній новелі” та “Арабесках” М. Хвильового. Досліджуються елементи “міського тексту” Харкова, присутні у творах. Образ міста, зображеного у новелах, співвідноситься з містом концентричного й ексцентричного типу, містом-дівою, містом- блудницею, містом-карнавалом, містом-ярмарком. Ключові слова: образ міста, місто концентричного типу, місто ексцентричного типу, місто-діва, місто-блудниця, місто-карнавал, “міський текст” Харкова.Стаття посвящается образу города в “Вступительной новелле” и “Арабесках” М. Хвылевого. Исследуются элементы “городского текста” Харькова, присутствующие в произведениях. Образ города, изображенного в новеллах соотносится с городом концентрического и эксцентрического типа, городом-девой, городом-блудницей, городом-карнавалом. Ключевые слова: образ города, город концентрического типа, город эксцентрического типа, город-дева, город-блудница, город-карнавал, “городской текст” Харькова.The article is devoted to an image of a city in M. Hvylevogo’s “The introductory short story” and “Arabesques”. Elements of Kharkovs “the city text” are investigated. The image of the city represented in short stories corresponds with a city of concentric and eccentric type, a city-maiden, a city-loose woman, a city-carnival. Keywords: an image of a city, a city of concentric type, a city of eccentric type, a city-maiden, a city-loose woman, a city-carnival, “the city text” of Kharkov