Efficacy and mapping of resistance to Mycosphaerella graminicola in wheat

Wheat is the most important food and feed crop, contributing about 19% of the required human dietary energy. The annual growth rate of the global cereal production -including wheat- is below one per cent. This is due to biotic and biotic constraints – including diseases – such that production falls short of meeting future food demands. Thus more wheat should be produced and the best way to achieve that is to produce and release cultivars with better disease resistance. Septoria tritici blotch (STB) is Europe’s major foliar wheat disease and is caused by the fungus Mycosphaerella graminicola that reduces yields to at least 50% under conducive conditions. STB management relies mostly on chemical control, but the continuously increasing incidence of fungicide resistant strains in fungal populations has resulted in a growing awareness of the importance of host resistance. However, the number of identified resistance genes to STB is very low compared to the number of known resistance genes for other wheat diseases. Moreover, these genes are not very effective and therefore of limited practical value. The aim of this research was to discover new genes for resistance and to develop tools facilitating their deployment in modern breeding programs. Three new resistance genes were detected on chromosomes 3DL, 5AL and 6DS that were designated as Stb16, Stb17 and Stb18, respectively. Stb17 was only expressed in adult plants, which is new for this disease, Stb18 is effective to a limited suite of isolates, but Stb16 has an extremely broad resistance that is of great interest to the commercial breeding industry. However, the impact of an individual gene depends strongly of the genetic make-up of a cultivar. Along with improved testing protocols these results are important for the successful commercial deployment of Stb genes in European wheat breeding programs.</p

Advancing Nonlinear Design of Buildings under Extreme Wind Loads

Performance-based wind engineering has gained considerable interest among researchers and practicing engineers due to its potential benefits in improving structural performance, safety, and economy of buildings and other structures. One of the main requirements for successful implementation of performance-based wind design is to have a thorough understanding of the nonlinear response of the building up to collapse, even when collapse is unlikely in wind events. Currently, there is very little knowledge on the prediction of the nonlinear wind-induced response of the building structures. The main objective of this dissertation is to improve our understanding of the nonlinear wind-induced response of the buildings under extreme wind loads to advance performance-based wind design methods. To achieve this goal, this doctoral study has investigated the importance and necessity of performance-based wind design of the buildings in terms of safety and economy of the design by conducting a detailed performance-based assessment of a 20-story steel-moment resting frame as a case study through both deterministic and probabilistic approaches. The nonlinear response of the frame up to the collapse point when subjected to strong wind storms was also investigated using the two deterministic and probabilistic approaches as well. The simulation results were used to investigate the importance of adding uncertainties in the prediction of wind-induced response of the buildings by comparing the predicted frame response obtained from the deterministic and probabilistic simulations. Additionally, the effect of nonlinear building behavior on the variation of aerodynamic feedback measured from low-rise, mid-rise, and high-rise buildings was investigated. The effect of nonlinear building response on initiating or intensifying wind-induced instabilities, such as vortex-induced vibration, is also studied. The overall outcome of the study highlights the highly conservative design of the elements of the main wind force resisting systems. Meanwhile, the serviceability performance objectives for the considered buildings did not meet the acceptance criteria when both deterministic and probabilistic approaches are employed. The importance of incorporating uncertainties into the wind-induced response of the building especially as the level of nonlinearity increases is another key finding of this study. Finally, it was shown that the nonlinear behavior of the buildings does not cause any additional adverse FSI effects, and in fact, could even help with improving structural stability in cases of low inherent structural damping levels due to the hysteretic energy dissipation

Identification of a new resistance gene to septoria tritici blotch in wheat

Door het screenen van lijnen en wilde verwanten van tarwe, is een nieuw resistentiegen tegen STB (Septoria tritici blotch) gevonden

Effects of Acetyl-L-Carnitine on Cardiac Arrhythmias and Infarct Size in Ischemic-Reperfused Isolated Rat Heart

This study aimed to examine whether acetyl-L-carnitine (ALC) was able to reduce cardiac arrhythmias and infarct size in the ischemic-reperfused isolated rat heart.Materials and MethodsThe isolated hearts were mounted on a Langendorff apparatus then perfused by a modified Krebs-Henseleit solution during 30 min regional ischemia and 120 min reperfusion (control) or by enriched Krebs solution with 0.375, 0.75, 1.5 and 3 mM of ALC (treatment groups). The ECGs were recorded and analyzed to determine cardiac arrhythmias. The infarct size was determined by using a computerized planimetry package.ResultsDuring ischemia, all used concentrations of ALC decreased number and duration of ventricular tachycardia (VT), total number of ventricular ectopic beats (VEBs) (P<0.01), incidence of total ventricular fibrillation (VF) and the time spent for reversible VF (P<0.05). At the reperfusion phase, duration of VT, incidence of total VF and reversible VF were significantly lowered by ALC (P<0.05). In addition, infarct size significantly was decreased in all treated groups. In the control group, the infarct size was 23±3.1%, however, ALC (0.375, 0.75 and 3 mM) reduced it to 8.7±2.3, 5.3±1.4, and 8±2.9%, respectively (P<0.01). ConclusionConsidering the results, it may be concluded that ALC has protective effects against cardiac ischemia-reperfusion (I/R) injuries by reduction of infarct size and arrhythmias in isolated rat heart. Among the potential cardioprotective mechanisms for ALC, increase in glucose oxidation and resulting reduced lactate production, reduction of toxic fatty acid metabolites and removing free radicals from the myocytes are more relevant

Charged Particles Multiplicity and Scaling Violation of Fragmentation Functions in Electron-Positron Annihilation

By the use of data from the annihilation process of electron-positron in AMY detector at 60 GeV center of mass energy, charged particles multiplicity distribution is obtained and fitted with the KNO scaling. Then, momentum spectra of charged particles and momentum distribution with respect to the jet axis are obtained, and the results are compared to the different models of QCD; also, the distribution of fragmentation functions and scaling violations are studied. It is being expected that the scaling violations of the fragmentation functions of gluon jets are stronger than the quark ones. One of the reasons for such case is that splitting function of quarks is larger than splitting function of gluon

The Origin of Chern-Simons Modified Gravity from an 11 + 3-Dimensional Manifold

It is our aim to show that the Chern-Simons terms of modified gravity can be understood as generated by the addition of a 3-dimensional algebraic manifold to an initial 11-dimensional space-time manifold; this builds up an 11+3-dimensional space-time. In this system, firstly, some fields living in the bulk join the fields that live on the 11-dimensional manifold, so that the rank of the gauge fields exceeds the dimension of the algebra; consequently, there emerges an anomaly. To solve this problem, another 11-dimensional manifold is included in the 11+3-dimensional space-time, and it interacts with the initial manifold by exchanging Chern-Simon fields. This mechanism is able to remove the anomaly. Chern-Simons terms actually produce an extra manifold in the pair of 11-dimensional manifolds of the 11+3-space-time. Summing up the topology of both the 11-dimensional manifolds and the topology of the exchanged Chern-Simons manifold in the bulk, we conclude that the total topology shrinks to one, which is in agreement with the main idea of the Big Bang theory