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PurposeThe purpose of this study is to simultaneously determine the constitutive parameters and boundary conditions by solving inverse mechanical problems of power hardening elastoplastic materials in three-dimensional geometries.Design/methodology/approachThe power hardening elastoplastic problem is solved by the complex variable finite element method in software ABAQUS, based on a three-dimensional complex stress element using user-defined element subroutine. The complex-variable-differentiation method is introduced and used to accurately calculate the sensitivity coefficients in the multiple parameters identification method, and the Levenberg–Marquardt algorithm is applied to carry out the inversion.FindingsNumerical results indicate that the complex variable finite element method has good performance for solving elastoplastic problems of three-dimensional geometries. The inversion method is effective and accurate for simultaneously identifying multi-parameters of power hardening elastoplastic problems in three-dimensional geometries, which could be employed for solving inverse elastoplastic problems in engineering applications.Originality/valueThe constitutive parameters and boundary conditions are simultaneously identified for power hardening elastoplastic problems in three-dimensional geometries, which is much challenging in practical applications. The numerical results show that the inversion method has high accuracy, good stability, and fast convergence speed.

Leucine-rich repeat extensins (LRXs) are required for plant growth and development through affecting cell growth and cell wall formation. LRX gene family can be classified into two categories: predominantly vegetative-expressed LRX and reproductive-expressed PEX. In contrast to the tissue specificity of Arabidopsis PEX genes in reproductive organs, rice OsPEX1 are also highly expressed in roots in addition to reproductive tissue. However, whether and how OsPEX1 affects root growth is unclear. Here, we found that overexpression of OsPEX1 in the pex1 mutant retarded root growth by reducing cell elongation resulting from an increase of lignin deposition, whereas knockdown of OsPEX1 had an opposite effect on root growth, indicating that OsPEX1 negatively regulated root growth in rice seedling. Upon further investigation, we uncovered the existence of a feedback loop between OsPEX1 transcription and GA biosynthesis for proper root growth. This was supported by the facts that exogenous GA3 application downregulated the transcription levels of OsPEX1 and lignin-related genes, rescuing the development defects of the root in the pex1 mutant, whereas OsPEX1 negatively regulated GA level by altering the expression of GA biosynthesis genes. Moreover, OsPEX1 and GA showed antagonistic action on the lignin biosynthesis in root. OsPEX1 overexpression upregulated the transcription levels of lignin-related genes, whereas exogenous GA application downregulated their expression, accompanied by altered root growth phenotypes. Taken together, our studies reveal a possible molecular pathway of OsPEX1-mediated root growth through coordinate modulation of lignin deposition via a negative feedback regulation between OsPEX1 transcription and GA biosynthesis.

Purpose The purpose of this paper is to propose a new strong-form numerical method, called the free element method, for solving general boundary value problems governed by partial differential equations. The main idea of the method is to use a locally formed element for each point to set up the system of equations. The proposed method is used to solve the fluid mechanics problems. Design/methodology/approach The proposed free element method adopts the isoparametric elements as used in the finite element method (FEM) to represent the variation of coordinates and physical variables and collocates equations node-by-node based on the newly derived element differential formulations by the authors. The distinct feature of the method is that only one independently formed individual element is used at each point. The final system of equations is directly formed by collocating the governing equations at internal points and the boundary conditions at boundary points. The method can effectively capture phenomena of sharply jumped variables and discontinuities (e.g. the shock waves). Findings a) A new numerical method called the FEM is proposed; b) the proposed method is used to solve the compressible fluid mechanics problems for the first time, in which the shock wave can be naturally captured; and c) the method can directly set up the system of equations from the governing equations. Originality/value This paper presents a completely new numerical method for solving compressible fluid mechanics problems, which has not been submitted anywhere else for publication.

RIP2 serves as a negative regulator of leaf inclination through the coordination of BR signaling in rice. Leaf angle is considered as an important morphological trait in rice. Appropriate leaf angle increases the efficiency of sunlight capture and maintains a high level of photosynthesis, ultimately improving crop yield. Our present study demonstrates that RIP2 encodes a RING finger E3 ligase protein that directly binds to ROLLED AND ERECT LEAF 1 (REL1), a key regulator of leaf morphogenesis. Further studies reveal that RIP2 is extensively involved in leaf inclination through the coordination of BR signaling. Repression of RIP2 led to altered phenotypes, including enlarged leaf inclination and fewer tillers. Conversely, rice overexpressing RIP2 exhibited erect leaves. The double mutant rel1 rip2 displayed phenotypes similar to those of rel1, characterized by rolled leaves. Transcriptome profiling of WT, rel1, rip2, and rel1 rip2 mutants revealed that BR and IAA signaling pathways were impaired in rip2. Moreover, rel1, rip2, and rel1 rip2 were insensitive to BR treatment. In summary, these findings demonstrate that RIP2 serves as a negative regulator of leaf inclination, and therefore, provides an approach for the optimization of an ideal plant type.

Leaf rolling is one of the most significant symptoms of drought stress in plant. Previously, we identified a dominant negative mutant, termed rolled and erect 1 (hereafter referred to rel1-D), regulating leaf rolling and erectness in rice. However, the role of REL1 in drought response is still poorly understood. Here, our results indicated that rel1-D displayed higher tolerance to drought relative to wild type, and the activity of superoxide dismutase (SOD) and drought responsive genes were significantly up-regulated in rel1-D. Moreover, our results revealed that rel1-D was hypersensitive to ABA and the expression of ABA associated genes was significantly increased in rel1-D, suggesting that REL1 likely coordinates ABA to regulate drought response. Using the RNA-seq approach, we identified a large group of differentially expressed genes that regulate stimuli and stresses response. Consistently, we also found that constitutive expression of REL1 alters the expression of biotic and abiotic stress responsive genes by the isobaric tags for relative and absolute quantification (iTRAQ) analysis. Integrative analysis demonstrated that 8 genes/proteins identified by both RNA-seq and iTRAQ would be the potential targets in term of the REL1-mediated leaf morphology. Together, we proposed that leaf rolling and drought tolerance of rel1-D under normal condition might be caused by the endogenously perturbed homeostasis derived from continuous stressful dynamics. Electronic supplementary material The online version of this article (10.1186/s12284-018-0251-0) contains supplementary material, which is available to authorized users.

Highlight The Albino Leaf 2 (AL2) gene is involved in the splicing of chloroplast group I and II introns and is responsible for chloroplast development in rice., Chloroplasts play an essential role in plant growth and development through manipulating photosynthesis and the production of hormones and metabolites. Although many genes or regulators involved in chloroplast biogenesis and development have been isolated and characterized, identification of novel components is still lacking. We isolated a rice (Oryza sativa) mutant, termed albino leaf 2 (al2), using genetic screening. Phenotypic analysis revealed that the al2 mutation caused obvious albino leaves at the early developmental stage, eventually leading to al2 seedling death. Electron microscopy investigations indicated that the chloroplast structure was disrupted in the al2 mutants at an early developmental stage and subsequently resulted in the breakdown of the entire chloroplast. Molecular cloning illustrated that AL2 encodes a chloroplast group IIA intron splicing facilitator (CRS1) in rice, which was confirmed by a genetic complementation experiment. Moreover, our results demonstrated that AL2 was constitutively expressed in various tissues, including green and non-green tissues. Interestingly, we found that the expression levels of a subset of chloroplast genes that contain group IIA and IIB introns were significantly reduced in the al2 mutant compared to that in the wild type, suggesting that AL2 is a functional CRS1 in rice. Differing from the orthologous CRS1 in maize and Arabidopsis that only regulates splicing of the chloroplast group II intron, our results demonstrated that the AL2 gene is also likely to be involved in the splicing of the chloroplast group I intron. They also showed that disruption of AL2 results in the altered expression of chloroplast-associated genes, including chlorophyll biosynthetic genes, plastid-encoded polymerases and nuclear-encoded chloroplast genes. Taken together, these findings shed new light on the function of nuclear-encoded chloroplast group I and II intron splicing factors in rice.

Highlight The Rolled and Erect Leaf 1 (REL1) gene is a novel component controlling brassinosteroid signalling-associated leaf morphogenesis and leaf angle in Oryza sativa., Leaf morphology, particularly in crop, is one of the most important agronomic traits because it influences the yield through the manipulation of photosynthetic capacity and transpiration. To understand the regulatory mechanism of leaf morphogenesis, an Oryza sativa dominant mutant, rolled and erect leaf 1 (rel1) has been characterized. This mutant has a predominant rolled leaf, increased leaf angle, and reduced plant height phenotype that results in a reduction in grain yield. Electron microscope observations indicated that the leaf incurvations of rel1 dominant mutants result from the alteration of the size and number of bulliform cells. Molecular cloning revealed that the rel1 dominant mutant phenotype is caused by the activation of the REL1 gene, which encodes a novel unknown protein, despite its high degree of conservation among monocot plants. Moreover, the downregulation of the REL1 gene in the rel1 dominant mutant restored the phenotype of this dominant mutant. Alternatively, overexpression of REL1 in wild-type plants induced a phenotype similar to that of the dominant rel1 mutant, indicating that REL1 plays a positive role in leaf rolling and bending. Consistent with the observed rel1 phenotype, the REL1 gene was predominantly expressed in the meristem of various tissues during plant growth and development. Nevertheless, the responsiveness of both rel1 dominant mutants and REL1-overexpressing plants to exogenous brassinosteroid (BR) was reduced. Moreover, transcript levels of BR response genes in the rel1 dominant mutants and REL1-overexpressing lines were significantly altered. Additionally, seven REL1-interacting proteins were also identified from a yeast two-hybrid screen. Taken together, these findings suggest that REL1 regulates leaf morphology, particularly in leaf rolling and bending, through the coordination of BR signalling transduction.

Image algebra is a powerful algebraic language for image processing. The most powerful tools of image algebra are three basic image-template operations: the generalized convolution, the additive maximum, and the multiplicative maximum. In this paper, these operations on real value images with translation invariant templates are proposed to be implemented by an optoelectronic architecture. The architecture is of two layers: a multi-imaging-threshold layer and a correlating layer. A two-rail spatial intensity coding method is obtained for real numbers' computation. Experiment result on 1D images is demonstrated, too.

The CC-banyan network represents a large class of nonequivalent multistage interconnection networks. The optical implementation of a regular rectangular CC-banyan network, which is based on polarizing beam splitters and 1D liquid crystal spatial light modulators, is proposed and demonstrated, and its corresponding routing control for a path between any (S, D) pair is given. It possesses a low energy loss, a high signal-to-noise ratio and an available large number of optical channels.

Based on programmable polarization-optical neighborhood interconnection, which is a stacked integration of rotatable crystal plates for beam splitting the controllable wave plates for polarization direction controlling, a kind of morphological processor with real-time programmable structure elements is developed. It is compact in structure and effective as well as stable in performance.

A ready-assemble and parallel polarization-optical logic processor is developed, which is based on the birefraction of uniaxial crystals. The suggested processor is a stacked integration of calcite plates for beam splitting and combination and polarization rotators for polarization direction control. All 16 logic functions of two input patterns can be implemented by customizing a control panel. It is compact in structure, effective in performance and insensitive to environmental influences.

In view of its fundamental role arising in numerous fields of science and engineering, the problem of online solving quadratic programs (QP) has been investigated extensively for the past decades. One of the state-of-the-art recurrent neural network (RNN) solvers is dual neural network (DNN). The dual neural network is of simple piecewise-linear dynamics and has global convergence to optimal solutions. Its exponential-convergence property relies on a so-called exponential convergence condition. Such a condition often exists in practice but seems difficult to be proved. In this paper, we investigate the proof complexity of such a condition by analyzing its one-dimensional case. The analysis shows that in general the exponential convergence condition often exists for dual neural networks, and always exists at least for the one-dimensional case. In addition, the analysis is very complex.

The routing scheme and some permutation properties of a four-shuffle-exchange-based Omega network are discussed. The corresponding optical setup, which is composed of 2-D phase spatial light modulators and calcite plates, is proposed and demonstrated through mapping the inputs to a 2-D array. Instead of one shuffle-exchange followed by one switching operation as in ordinary Omega networks, in our presented system, the shuffle interconnection embraced in the switches is accomplished simply by varying the switching structure of each stage. For the proposed polarization-optical modules, the system is compact in structure, efficient in performance, and insensitive to the environment. (C) 1997 Society of Photo-Optical Instrumentation Engineers.

A 2-D SW-banyan network is introduced by properly folding the 1-D SW-banyan network, and its corresponding optical setup is proposed by means of polarizing beamsplitters and 2-D phase spatial light modulators. Then, based on the characteristics and the proposed optical setup, the control for the routing path between any source-destination pair is given, and the method to determine whether a given permutation is permissible or not is discussed. Because the proposed optical setup consists of only optical polarization elements, it is compact in structure, its corresponding energy loss and crosstalk are low, and its corresponding available number of channels is high. (C) 1996 Society of Photo-Optical Instrumentation Engineers.

An all solid state integrated optical cellular two-layer logic image processor, which can be used for binary image processing, has been designed and fabricated. The first layer is an optical parallel self-programming logic processor, constructed with prism combinations. The second layer is an optical, morphological dilation processor assembled with birefringent plates. The complete system uses the direct cascade of these two processors. It is shown that the integrated system is compact in structure, insensitive to environmental influences, and efficient in performance.