Evaluation of Waterlogging Tolerance in Twenty-One Cultivars and Genotypes of Bread Wheat (Triticum Aestivum L.) and its Effect on some Physiological Characteristics of Shoot and Root System at the Three-Leaf Stage

IntroductionCovering a staggering 215 million hectares, wheat stands as the world's most extensively cultivated crop plant. Just like its botanical counterparts, wheat operates as an obligate aerobic organism, implying its reliance on absorbing oxygen from the surrounding environment to facilitate growth, proliferation, and the successful completion of its life cycle. Annual instances of waterlogging stress inflict harm upon wheat crops, attributed to inadequate irrigation practices, subpar drainage systems, uneven field leveling, elevated groundwater levels, the presence of unyielding impermeable layers, and bouts of intense, abrupt rainfall. This adverse impact is progressively escalating, potentially influenced by the ongoing shifts in climate patterns. Consequently, the adoption of resilient cultivars and the genetic enhancement of bread wheat assume critical importance. These strategies are aimed at augmenting the wheat's capacity to effectively cope with waterlogging stress, aligning it with the mounting demands of a burgeoning global population.To achieve these goals, it is necessary to understand the factors causing waterlogging stress damage in wheat and to know the mechanisms of tolerance in this plant. The survival of root terminal meristem cells under waterlogging stress conditions is very limited, and their ability to grow again after removing the stress is also restricted. Waterlogging stress leads to the death of primary roots and reduced growth of lateral roots in wheat. However, there is variation among wheat cultivars concerning these traits. Reduced access to oxygen hampers root growth and nutrient absorption, including nitrogen. Consequently, photosynthesis and carbohydrate availability decrease, further restricting root growth.Materials and MethodsAn outdoor pot experiment was conducted to investigate the effect of waterlogging stress on shoot and root dry matter, as well as some physiological characteristics. The experiment followed a split-plot design based on randomized complete blocks with three replications. The stress was applied at the three-leaf stage, and three control levels were used: no waterlogging stress, mild stress (48 hours of waterlogging stress), and severe stress (120 hours of waterlogging stress) as the main factors. Cultivars and genotypes were also included as secondary factors.During the stress period, the water level was maintained at approximately 5 cm above the soil level. The cultivation took place outdoors in plastic pots. Data analysis was performed using SAS software, and graphs were generated using Excel software. Comparisons between treatments were based on the standard error. After testing different models, the linear regression model was ultimately employed.Results and DiscussionMild and severe waterlogging stress resulted in a significant decrease in shoot dry matter of 14.06% and 38.37%, respectively, across all cultivars and genotypes. Different cultivars and genotypes exhibited varying responses to waterlogging stress. To further understand the reasons for these differences, among the 21 cultivars and genotypes, Mehrgan and Sarang cultivars, as well as ms 93-16 and ms 93-6 genotypes, were selected due to their contrasting tolerance levels and yield potential. These selected cultivars and genotypes were studied to analyze specific root traits.Amidst severe waterlogging stress, a significant 38% reduction in root dry matter and a corresponding 29% decrease in root volume were recorded when compared to stress-free conditions. This closely mirrored the decline evident in shoot dry matter. Evaluation of the susceptibility index during the three-leaf stage unveiled that sole resilience was exhibited by the Aflak cultivar. In contrast, the remaining cultivars and genotypes were stratified into semi-tolerant and semi-susceptible categories.Notably, regression analysis underscored that even brief periods of waterlogging stress ushered in a reduction in dry matter. Furthermore, the elongation of the waterlogging duration magnified this decrease in dry matter, thereby mitigating the disparities across various cultivars and genotypes.ConclusionIn general, cultivars that were able to sustain higher levels of photosynthetic activity during waterlogging stress demonstrated a lower percentage decrease in dry matter. Although the Mehrgan cultivar experienced a significant reduction in dry matter yield and fell into the semi-sensitive group, it consistently exhibited significantly higher dry matter yield compared to other cultivars and genotypes across all treatments.AcknowledgmentThe authors express their gratitude to the Agriculture Research Center of Khuzestan for providing the seeds, the Research Vice-Chancellor of the Shahid Chamran University of Ahvaz for covering the costs, and all the employees of the Department of Plant Production and Genetics

Electric-field-induced alignment of electrically neutral disk-like particles: modelling and calculation

This work reveals a torque from electric field to electrically neutral flakes that are suspended in a higher electrical conductive matrix. The torque tends to rotate the particles toward an orientation with its long axis parallel to the electric current flow. The alignment enables the anisotropic properties of tiny particles to integrate together and generate desirable macroscale anisotropic properties. The torque was obtained from thermodynamic calculation of electric current free energy at various microstructure configurations. It is significant even when the electrical potential gradient becomes as low as 100 v/m. The changes of electrical, electroplastic and thermal properties during particles alignment were discussed

Lattice Boltzmann Simulation of Solid Particles Motion in a Three Dimensional Flow using Smoothed Profile Method

Three-dimensional particulate flow has been simulated using Lattice Boltzmann Method (LBM). Solid-fluid interaction was modeled based on Smoothed Profile Method (SPM) (Jafari et. al, Lattice-Boltzmann method combined with smoothed-profile method for particulate suspensions, Phys. Rev. E, 2011). In this paper a GPU code based on three-dimensional lattice Boltzmann method and smoothed profile method has been prepared due to the ability of SPM-LBM to perform locally and in parallel mode. Results obtained for sedimentation of one and two spherical particles as well as their behavior in shear flow showed excellent correspondence with previous published works. Computations for a large number of particles sedimentation showed that combination of LBM and SPM on a GPU platform can be considered as an efficient and promising computational frame work in particulate flow simulations

Nano-mechanical properties of Fe-Mn-Al-C lightweight steels

High Al Low-density steels could have a transformative effect on the light-weighting of steel structures for transportation and achieving the desired properties with the minimum amount of Ni is of great interest from an economic perspective. In this study, the mechanical properties of two duplex low-density steels, Fe-15Mn-10Al-0.8C-5Ni and Fe-15Mn-10Al-0.8C (wt.%) were investigated through nano-indentation and simulation through utilization of ab initio formalisms in Density Functional Theory (DFT) in order to establish the hardness resulting from two critical structural features (ߢ-carbides and B2 intermetallic) as a function of annealing temperature (500 − 1050 ℃) and the addition of Ni. In the Ni-free sample, the calculated elastic properties of kappa-carbides were compared with those of the B2 intermetallic Fe3Al − L12, and the role of Mn in the kappa structure and its elastic properties were studied. The Ni-containing samples were found to have a higher hardness due to the B2 phase composition being NiAl rather than FeAl, with Ni-Al bonds reported to be stronger than the Fe-Al bonds. In both samples, at temperatures of 900 ℃ and above, the ferrite phase contained nano-sized discs of B2 phase, wherein the Ni-containing samples exhibited higher hardness, attributed again to the stronger Ni-Al bonds in the B2 phase. At 700 ℃ and below, the nano-sized B2 discs were replaced by micrometre sized needles of kappa in the Ni-free sample resulting in a lowering of the hardness. In the Ni-containing sample, the entire alpha phase was replaced by B2 stringers, which had a lower hardness than the Ni-Al nano-discs due to a lower Ni content in B2 stringer bands formed at 700 ℃ and below. In addition, the hardness of needle-like kappa-carbides formed in alpha phase was found to be a function of Mn content. Although it was impossible to measure the hardness of cuboid kappa particles in gamma phase because of their nano-size, the hardness value of composite phases, e.g. gamma + kappa was measured and reported. All the hardness values were compared and rationalized by bonding energy between different atoms

Receipt of Cardiac Medications Upon Discharge Among Men and Women With Acute Coronary Syndrome and Nonobstructive Coronary Artery Disease

Background Management of acute coronary syndrome (ACS) patients with nonobstructive epicardial coronary artery disease (CAD) remains poorly understood. Hypothesis Acute coronary syndrome patients with nonobstructive CAD are less likely to receive effective cardiac medications upon discharge from the hospital. Methods We identified patients hospitalized with ACS that underwent coronary angiography and had a 6-month follow-up. Patients were grouped by CAD severity: nonobstructive CAD (<50% blockage in all vessels) or obstructive CAD (≥50% blockage in ≥ 1 vessels). Data were collected on demographics, medications at discharge, and adverse outcomes at 6 months, for all patients. Results Of the 2264 ACS patients included in the study: 123 patients had nonobstructive CAD and 2141 had obstructive CAD. Cardiac risk factors including hypertension and diabetes were common among patients with nonobstructive CAD. Men and women with nonobstructive CAD were less likely to receive cardiac medications compared to patients with obstructive CAD including aspirin (87.8% vs 95.0%, P = 0.001), Β-blockers (74.0% vs 89.2%, P < 0.001), or statins (69.1% vs 81.2%, P = 0.001). No gender-related differences in discharge medications were observed for patients with nonobstructive CAD. However, women with nonobstructive CAD had similar rates of cardiac-related rehospitalization as men with obstructive CAD (23.3% and 25.9%, respectively). Conclusions Patients with nonobstructive CAD are less likely to receive evidence-based medications compared to patients with obstructive CAD, despite the presence of CAD risk factors and occurrence of an ACS event. Further research is warranted to determine if receipt of effective cardiac medications among patients with nonobstructive CAD would reduce cardiac-related events. Copyright © 2010 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/64902/1/20701_ftp.pd

A re-evaluation of phylogenomic data reveals that current understanding in wheat blast population biology and epidemiology is obfuscated by oversights in population sampling.

Abstract: Wheat blast, caused by the Pyricularia oryzae Triticum lineage (PoT), first emerged in Brazil and quickly spread to neighboring countries. Its recent appearance in Bangladesh and Zambia highlights a need to understand the disease's population biology and epidemiology so as to mitigate pandemic outbreaks. Current knowledge is mostly based on characterizations of Brazilian wheat blast isolates and comparison with isolates from non-wheat, endemic grasses. These foregoing studies concluded that the wheat blast population lacks host specificity and, as a result, undergoes extensive gene flow with populations infecting non-wheat hosts. Additionally, based on genetic similarity between wheat blast and isolates infecting Urochloa species, it was proposed that the disease originally emerged via a host jump from this grass, and that Urochloa likely plays a central role in wheat blast epidemiology, owing to its widespread use as a pasture grass. However, due to inconsistencies with broader phylogenetic studies, we suspected that these seminal studies hadn't actually sampled the populations normally found on endemic grasses and, instead, had repeatedly isolated members of PoT and the related Lolium pathogen lineage (PoL1). Re-analysis of the Brazilian data as part of a comprehensive, global, phylogenomic dataset that included a small number of S. American isolates sampled away from wheat confirmed our suspicion and identified four new P. oryzae lineages on grass hosts. As a result, the conclusions underpinning current understanding in wheat blast's evolution, population biology and epidemiology are unsubstantiated and could be equivocal

The Surgical Infection Society revised guidelines on the management of intra-abdominal infection

Background: Previous evidence-based guidelines on the management of intra-abdominal infection (IAI) were published by the Surgical Infection Society (SIS) in 1992, 2002, and 2010. At the time the most recent guideline was released, the plan was to update the guideline every five years to ensure the timeliness and appropriateness of the recommendations. Methods: Based on the previous guidelines, the task force outlined a number of topics related to the treatment of patients with IAI and then developed key questions on these various topics. All questions were approached using general and specific literature searches, focusing on articles and other information published since 2008. These publications and additional materials published before 2008 were reviewed by the task force as a whole or by individual subgroups as to relevance to individual questions. Recommendations were developed by a process of iterative consensus, with all task force members voting to accept or reject each recommendation. Grading was based on the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) system; the quality of the evidence was graded as high, moderate, or weak, and the strength of the recommendation was graded as strong or weak. Review of the document was performed by members of the SIS who were not on the task force. After responses were made to all critiques, the document was approved as an official guideline of the SIS by the Executive Council. Results: This guideline summarizes the current recommendations developed by the task force on the treatment of patients who have IAI. Evidence-based recommendations have been made regarding risk assessment in individual patients; source control; the timing, selection, and duration of antimicrobial therapy; and suggested approaches to patients who fail initial therapy. Additional recommendations related to the treatment of pediatric patients with IAI have been included. Summary: The current recommendations of the SIS regarding the treatment of patients with IAI are provided in this guideline

Using electric current to surpass the microstructure breakup limit

The elongated droplets and grains can break up into smaller ones. This process is driven by the interfacial free energy minimization, which gives rise to a breakup limit. We demonstrated in this work that the breakup limit can be overpassed drastically by using electric current to interfere. Electric current free energy is dependent on the microstructure configuration. The breakup causes the electric current free energy to reduce in some cases. This compensates the increment of interfacial free energy during breaking up and enables the processing to achieve finer microstructure. With engineering practical electric current parameters, our calculation revealed a significant increment of the obtainable number of particles, showing electric current a powerful microstructure refinement technology. The calculation is validated by our experiments on the breakup of Fe3C-plates in Fe matrix. Furthermore, there is a parameter range that electric current can drive spherical particles to split into smaller ones

Emergence of contact injuries in invasion team sports : an ecological dynamics rationale

The incidence of contact injuries in team sports is considerable, and injury mechanisms need to be comprehensively understood to facilitate the adoption of preventive measures. In Association Football, evidence shows that the highest prevalence of contact injuries emerges in one-on-one interactions. However, previous studies have tended to operationally report injury mechanisms in isolation, failing to provide a theoretical rationale to explain how injuries might emerge from interactions between opposing players. In this position paper, we propose an ecological dynamics framework to enhance current understanding of behavioural processes leading to contact injuries in team sports. Based on previous research highlighting the dynamics of performer–environment interactions, contact injuries are proposed to emerge from symmetry-breaking processes during on-field interpersonal interactions among competing players and the ball. Central to this approach is consideration of candidate control parameters that may provide insights on the information sources used by players to reduce risk of contact injuries during performance. Clinically, an ecological dynamics analysis could allow sport practitioners to design training sessions based on selected parameter threshold values as primary and/or secondary preventing measures during training and rehabilitation sessions