Genome sequencing reveals the evolution and pathogenic mechanisms of the wheat sharp eyespot pathogen Rhizoctonia cerealis

The necrotrophic fungus Rhizoctonia cerealis is the causal agent of devastating diseases of cereal crops including wheat(Triticum aestivum).We present a high-quality genome assembly of R.cerealis Rc207,a virulent strain causing wheat sharp eyespot.The assembly(56.36 Mb)is composed of 17.87%repeat sequences and 14,433 predicted protein-encoding genes.The Rc207 genome encodes a large and diverse set of genes involved in pathogenicity,especially rich in those encoding secreted proteins,carbohydrateactive enzymes(CAZymes),peptidases,nucleases,cytochrome P450,and secondary metabolismassociated enzymes.Most secretory protein-encoding genes,including CAZymes,peroxygenases,dehydrogenases,and cytochrome P450,were up-regulated during fungal infection of wheat.We identified 831 candidate secretory effectors and validated the functions of 10 up-regulated candidate effector proteins.Of them,nine were confirmed as necrotrophic pathogen’s effectors promoting fungal infection.Abundant potential mobile or plastic genomic regions rich in repeat sequences suggest their roles in fungal adaption and virulence-associated genomic evolution.This study provides valuable resources for further comparative and functional genomics on important fungal pathogens,and provides essential tools for development of effective disease control strategies.

Damage and fracture model for eutectic composite ceramics

Study of damage and fracture models to analyze the fracture mechanism of eutectic composite ceramics is of considerable importance because no accurate fracture models are available for these materials. Eutectic composite ceramics are composed of microcells with random direction. We present herein a model that predicts the damage and fracture of eutectic composite ceramics based on analysis of defect stability and the damage localization band. Firstly, given the microstructure of eutectic composite ceramics, a mesodomain and a microcell model are constructed. The local stress field in the mesodomain is then analyzed based on the interaction direct derivative estimate. Secondly, the stability of a defect around particles in a microcell is analyzed, and the stress intensity factor of an annular defect under the applied stress field and the residual stress field in the particle are calculated. The stress intensity factor of a defect is controlled by the residual stress when the defect extension is small. However, it is controlled by the applied stress when the defect extension is large. Finally, a model for the damage localization band at the crack tip is constructed based on the Dugdale-Barenblatt model. The residual intensity is the important factor affecting the length of the damage localization band. When the damage variables reach their largest value, the residual in ten sity and the length of the damage localization band attain their minimum value. This work provides the theoretical basis for further study of the damage mechanics of eutectic composite ceramics and guides the engineering applications of these materials.

Evaluating and visualizing QoS of service providers in knowledgeintensive crowdsourcing:a combined MCDM approach

Purpose-As the number of joined service providers(SPs)in knowledge-intensive crowdsourcing(KI-C)continues to rise,there is an information overload problem for KI-C platforms and consumers to identify qualified SPs to complete tasks.To this end,this paper aims to propose a quality of service(QoS)evaluation framework for SPs in KI-C to effectively and comprehensively characterize the QoS of SPs,which can aid the efficient selection of qualified SPs.Design/methodology/approach-By literature summary and discussion with the expert team,a QoS evaluation indicator system for SPs in KI-C based on the SERVQUAL model is constructed.In addition,the Decision Making Trial and Evaluation Laboratory(DEMATEL)method is used to obtain evaluation indicators’weights.The SPs are evaluated and graded by the Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)and rank-sum ratio(RSR),respectively.Findings-A QoS evaluation indicator system for SPs in KI-C incorporating 13 indicators based on SERVQUAL has been constructed,and a hybrid methodology combining DEMATEL,TOPSIS and RSR is applied to quantify and visualize the QoS of SPs.Originality/value-The QoS evaluation framework for SPs in KI-C proposed in this paper can quantify and visualize the QoS of SPs,which can help the crowdsourcing platform to realize differentiated management for SPs and assist SPs to improve their shortcomings in a targeted manner.And this is the first paper to evaluate SPs in KI-C from the prospect of QoS.