Search

Understanding the relationships between host range and pathogenicity for parasites, and between the efficiency and scope of immunity for hosts are essential to implement efficient disease control strategies. In the case of plant parasites, most studies have focused on describing qualitative interactions and a variety of genetic and evolutionary models has been proposed in this context. Although plant quantitative resistance benefits from advantages in terms of durability, we presently lack models that account for quantitative interactions between plants and their parasites and the evolution of these interactions. Nestedness and modularity are important features to unravel the overall structure of host-parasite interaction matrices. Here, we analysed these two features on 32 matrices of quantitative pathogenicity trait data gathered from 15 plant-parasite pathosystems consisting of either annual or perennial plants along with fungi or oomycetes, bacteria, nematodes, insects and viruses. The performance of several nestedness and modularity algorithms was evaluated through a simulation approach, which helped interpretation of the results. We observed significant modularity in only six of the 32 matrices, with two or three modules detected. For three of these matrices, modules could be related to resistance quantitative trait loci present in the host. In contrast, we found high and significant nestedness in 30 of the 32 matrices. Nestedness was linked to other properties of plant-parasite interactions. First, pathogenicity trait values were explained in majority by a parasite strain effect and a plant accession effect, with no or minor parasite-plant interaction term. Second, correlations between the efficiency and scope of the resistance of plant genotypes, and between the host range breadth and pathogenicity level of parasite strains were overall positive. This latter result questions the efficiency of strategies based on the deployment of several genetically-differentiated cultivars of a given crop species in the case of quantitative plant immunity.

Summary: Grapevine downy mildew, caused by the oomycete Plasmopara viticola (P. viticola, Berk. & M. A. Curtis; Berl. & De Toni), is a global threat to Eurasian wine grapes Vitis vinifera. Although resistant grapevine varieties are becoming more accessible, P. viticola populations are rapidly evolving to overcome these resistances. We aimed to uncover avirulence genes related to Rpv3.1‐mediated grapevine resistance.We sequenced the genomes and characterized the development of 136 P. viticola strains on resistant and sensitive grapevine cultivars. A genome‐wide association study was conducted to identify genomic variations associated with resistant‐breaking phenotypes.We identified a genomic region associated with the breakdown of Rpv3.1 grapevine resistance (avrRpv3.1 locus). A diploid‐aware reassembly of the P. viticola INRA‐Pv221 genome revealed structural variations in this locus, including a 30 kbp deletion. Virulent P. viticola strains displayed multiple deletions on both haplotypes at the avrRpv3.1 locus. These deletions involve two paralog genes coding for proteins with 800–900 amino acids and signal peptides. These proteins exhibited a structure featuring LWY‐fold structural modules, common among oomycete effectors. When transiently expressed, these proteins induced cell death in grapevines carrying Rpv3.1 resistance, confirming their avirulence nature.This discovery sheds light on the genetic mechanisms enabling P. viticola to adapt to grapevine resistance, laying a foundation for developing strategies to manage this destructive crop pathogen. [ABSTRACT FROM AUTHOR]

This paper presents an innovative approach for supplier selection (SS) within the Tunisian dairy industry, with a specific focus on sustainability and resilience. The proposed method is a hybrid model that integrates multi-criteria decision-making (MCDM) with fuzzy logic. Initially, twelve distinct criteria are identified, categorized into social, environmental, economic, and resilience indexes through a combination of literature review and expert input. To establish the importance of these criteria, a fuzzy analytic hierarchy process (FAHP) is employed to calculate their weights. These weights are then integrated into a new method called fuzzy multi-attribute border approximation area comparison (FMABAC) to rank the suppliers. The methodology aims to provide decision-makers with a more intuitive means of expressing their preferences and evaluating supplier criteria, ultimately identifying the most effective dairy farmers. The research concludes by evaluating the results through two sensitivity analyses: one involving varying criteria weights and the other involving a comparative assessment with alternative fuzzy MCDM techniques. [ABSTRACT FROM AUTHOR]

In this paper, the observer design problem for a T-S fuzzy bilinear control system is investigated. First, an observer of Kalman type is designed to estimate the system states for the linear case. Then, some new sufficient conditions are derived to show the exponential convergence of the solutions of the error equation for fuzzy bilinear systems. Furthermore, we consider some uncertainties of the system that are bounded and satisfy a certain condition where an observer is designed. Moreover, an application to Van de Vusse system is given. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the notion of global practical exponential stability for Takagi-Sugeno fuzzy systems in presence of perturbations. The proposed approach for stability analysis is based on the determination of the bounds of perturbations that characterize the asymptotic convergence of the solutions to a small ball centered at the origin. The goal is to study systems whose desired behavior is asymptotic stability about the origin of the state space or a close approximation to this. All state trajectories are bounded and approach a sufficiently small neighborhood of the origin under some perurbations. The effectiveness of the presented criterion is demonstrated by a numerical example. [ABSTRACT FROM AUTHOR]

This research focuses on the home health care optimization problem that involves staff routing and scheduling problems. The considered problem is an extension of multiple travelling salesman problem. It consists of finding the shortest path for a set of caregivers visiting a set of patients at their homes in order to perform various tasks during a given horizon. Thus, a mixed-integer linear programming model is proposed to minimize the overall service time performed by all caregivers while respecting the workload balancing constraint. Nevertheless, when the time horizon become large, practical-sized instances become very difficult to solve in a reasonable computational time. Therefore, a new Learning Genetic Algorithm for mTSP (LGA-mTSP) is proposed to solve the problem. LGA-mTSP is composed of a new genetic algorithm for mTSP, combined with a learning approach, called learning curves. Learning refers to that caregivers' productivity increases as they gain more experience. Learning curves approach is considered as a way to save time and costs. Simulation results show the efficiency of the proposed approach and the impact of learning curve strategy to reduce service times. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of stabilization by an estimated state feedback for a family of nonlinear time-delay Takagi-Sugeno fuzzy parameterized systems. The delay is supposed to be constant where the parameter-dependent controls laws are used to compensate the nonlinearities which are formulated in terms of linear matrix inequalities (LMIs). Based on the LyapunovKrasovskii functionals, global exponential stability of the closed-loop systems is achieved. The controller and observer gains are able to be separately designed even in the presence of modeling uncertainty and state delay. Finally, a numerical example is given to show the applicability of the main result. [ABSTRACT FROM AUTHOR]

Recently, sustainable supply chain management (SSCM) has grown considerably at agro-food supply chain (AFSC). Due to their complex nature, these supply chains are exposed to a variety of interrelated risks from natural disasters and manmade. Hence, one of the fundamental concerns in the AFSC is identifying and prioritizing risks to achieve sustainability. However, in analyzing sustainability concerns, most previous studies have paid less attention to interrelationship between sustainability and risk assessment. The objective of this work is to propose a methodology to supply chain sustainability risk assessment by evaluating environmental, economic, social and operational risks. The proposed approach is an integrated rough decision-making and trial evaluation laboratory (DEMATEL) method for solving this problem, which takes into account the interrelationship between different risks and the group preference variety. The proposed methodology integrates the strength of DEMATEL approach in exploring both internal strength and external influence of risks as well as the advantage of rough number in manipulating the vagueness of information. A real-world case study of a Tunisian dairy company is presented to test the applicability of the proposed framework. It can be observed from results that the most important risks are "Large number of intermediaries", "Lack of proper storage facilities" and "Transport disruption". The results and findings can help the dairy sector decision-makers in a variety of ways to successfully identify and prioritize supply chain risks in order to attain sustainability. [ABSTRACT FROM AUTHOR]

Controlling the behavior of terminal alkynes in metal-catalyzed intermolecular tandem reactions is a formidable challenge despite the potential advantage offered by these strategies in modern synthesis. Herein, we describe that a nickel catalyst enables a tandem process involving the rapid dimerization of terminal alkynes into 1,3-enynes and the cycloaddition of these intermediates with an azetidinone, an oxetanone or benzocyclobutenones. Significantly, the slow or sequential addition of reagents and catalysts is not required to orchestrate their reactivity. These results are in stark contrast with previous cycloadditions of terminal alkynes with strained four-membered ring substrates, which previously led to oligomerization or cyclotrimerization, except in the case of tert -butylacetylene. [ABSTRACT FROM AUTHOR]