Knockout of Auxin Response Factor SlARF4 Improves Tomato Resistance to Water Deficit

Auxin response factors (ARFs) play important roles in various plant physiological processes; however, knowledge of the exact role of ARFs in plant responses to water deficit is limited. In this study, SlARF4, a member of the ARF family, was functionally characterized under water deficit. Real-time fluorescence quantitative polymerase chain reaction (PCR) and β-glucuronidase (GUS) staining showed that water deficit and abscisic acid (ABA) treatment reduced the expression of SlARF4. SlARF4 was expressed in the vascular bundles and guard cells of tomato stomata. Loss of function of SlARF4 (arf4) by using Clustered Regularly Interspaced Short Palindromic Repeats/Cas 9 (CRISPR/Cas 9) technology enhanced plant resistance to water stress and rehydration ability. The arf4 mutant plants exhibited curly leaves and a thick stem. Malondialdehyde content was significantly lower in arf4 mutants than in wildtype plants under water stress; furthermore, arf4 mutants showed higher content of antioxidant substances, superoxide dismutase, actual photochemical efficiency of photosystem II (PSII), and catalase activities. Stomatal and vascular bundle morphology was changed in arf4 mutants. We identified 628 differentially expressed genes specifically expressed under water deficit in arf4 mutants; six of these genes, including ABA signaling pathway-related genes, were differentially expressed between the wildtype and arf4 mutants under water deficit and unlimited water supply. Auxin responsive element (AuxRE) elements were found in these genes’ promoters indicating that SlARF4 participates in ABA signaling pathways by regulating the expression of SlABI5/ABF and SCL3, thereby influencing stomatal morphology and vascular bundle development and ultimately improving plant resistance to water deficit.     

High gain observer for a class of nonlinear systems with coupled structure and sampled output measurements: application to a quadrotor

This paper proposes a new high gain observer for a class of non-uniformly observable nonlinear systems with coupled structure driven by sampled outputs. The considered class of systems is particularly constituted by several subsystems where each subsystem is associated to a subset of the output variables. The observer design is carried out through two steps. First, a high-gain observer is proposed in the continuous-time output case under the assumption that an adequate persistent excitation condition is satisfied by each subsystem. Then, the proposed observer is redesigned to handle the case of sampled outputs leading thereby to a continuous-discrete time observer. The latter property is achieved thanks to the approach pursued along the convergence analysis. The effectiveness of the proposed observer is emphasised in a realistic simulation framework involving a mathematical model of a quadrotor which is diffeomorphic to the proposed class of considered systems.     

Adaptive fuzzy controller for non-affine systems with zero dynamics

In this article, the direct adaptive fuzzy control problem is investigated for a class of general non-linear systems with zero dynamics. The direct adaptive fuzzy controller is developed based on a unified observer which is used to estimate the time derivatives of the output. The corrective term of the proposed observer involves a well-defined design function which is shown to be satisfied by the commonly used high-gain-based observers, namely for the usual high-gain observers and the sliding-mode observers together with their implementable versions. By using a general error function, and without resorting to the famous strictly positive real condition or the filtering of the observation error, a general proportional–integral (PI) law for updating the fuzzy parameters is proposed. Ultimately boundedness of the error signals is shown through Lyapunov's direct method. Theoretical results are illustrated through two simulation examples.     

ER5, a tomato cDNA encoding an ethylene-responsive LEA-like protein: characterization and expression in response to drought, ABA and wounding

We report the isolation by differential display of a novel tomato ethylene-responsive cDNA, designated ER5. RT-PCR analysis of ER5 expression revealed an early (15 min) and transient induction by ethylene in tomato fruit, leaves and roots. ER5 mRNA accumulated during 2 h of ethylene treatment and thereafter underwent a dramatic decline leading to undetectable expression after 5 h of treatment. The full-length cDNA clone of 748 bp was obtained and DNA sequence analysis showed strong homologies to members of the atypical hydrophobic group of the LEA protein family. The predicted amino acid sequence shows 67%, 64%, 64%, and 61% sequence identity with the tomato Lemmi9, soybean D95-4, cotton Lea14-A, and resurrection plant pcC27-45 gene products, respectively. As with the other members of this group, ER5 encodes a predominantly hydrophobic protein. Prolonged drought stress stimulates ER5 expression in leaves and roots, while ABA induction of this ethylene-responsive clone is confined to the leaves. The use of 1-MCP, an inhibitor of ethylene action, indicates that the drought induction of ER5 is ethylene-mediated in tomato roots. Finally, wounding stimulates ER5 mRNA accumulation in leaves and roots. Among the Lea gene family this novel clone is the first to display an ethylene-regulated expression.     

Effect of lysoplatelet-activating factor on human sperm fertilizing ability

OBJECTIVE: To evaluate the penetration rates in the hamster zona-free oocyte sperm penetration assay (SPA) after exposure of spermatozoa to lysoplatelet-activating factor (LPAF) and lysophosphatidyl choline (LPC). DESIGN: Washed human spermatozoa were exposed to 100 microM of LPAF or LPC, followed by the assessment of their fertilizing ability using the SPA. The percentage of penetration, the sperm binding in the SPA, the percentage of motile spermatozoa, and the acrosome reaction rates were quantified. SETTING: Private research and university laboratories. PATIENTS, PARTICIPANTS: Fresh and frozen semen samples from fertile donors with proven fertility were used as well as fresh semen from infertile patients attending a fertility clinic. All the infertile patients had abnormal semen analysis. INTERVENTIONS: Human spermatozoa were incubated for 90 minutes in the presence or absence of LPAF or LPC at 100 microM with 0.3% albumin in Ham's F-10 (GIBCO, Dorval, Quebec, Canada), and their fertilizing ability was evaluated using the SPA. The effect of these lysophospholipids on the percentage of acrosome reaction was evaluated with a fluorescent microscopy technique. RESULTS: The penetration rates of the SPA in male factor increased significantly from 3% +/- 6% with controls to 19% +/- 9% and 34% +/- 22% after incubation with LPC and LPAF, respectively. Sperm-oocyte binding was not significantly increased in this group. Sperm penetration assay penetration rates were also increased in fertile cryopreserved spermatozoa with LPC and LPAF. In this group, the acrosome reaction was significantly increased from 2% +/- 1% in controls to 10% +/- 6% and 8% +/- 3% after incubation with LPC and LPAF, respectively. CONCLUSION: Lysoplatelet-activating factor and LPC independently increased the penetration rate of spermatozoa and the percentage of acrosome reaction. Lysophosphatidylcholine and LPAF may be beneficial in the treatment of spermatozoa with male factor infertility and may increase fertilization rates in IVF.     

Analysis of the electrical transport,conductivity, and dielectric relaxation behavior of La0.75 Ba0.10 Sr0.15 Fe O2.875-δ (δ = 0.375 and 0.50) brownmillerite oxides

The topotactic reduction of La_0.75Ba_0.10Sr_0.15FeO_2.875 with titanium metal leads to a new isostructural material of the composition La_0.75Ba_0.10Sr_0.15FeO_2.875-δ (δ?=?0.375 and 0.50). XRD analysis of phases confirms that the obtained compound adopts a brownmillerite-type structure. A slight distorted monoclinic P2/m was found to describe the crystal structure. The transport properties have been investigated by current–voltage (I–V). The electric and dielectric measurements were carried out covering a wide range of temperature (300–600 K). Our materials display semiconducting properties as well as mixed ionic and electronic conductivity. At high temperatures, the activation energy values proved to be around 907–630 meV, which refers basically to oxygen vacancies conduction. The analysis of dielectric properties and dielectric losses (ε’, tanδ) of both compounds vs temperature at different frequencies demonstrates two relaxer attitudes. A low dielectric loss and low electrical conductance were displayed. Relying upon these values, these materials stand for perfect candidates for micro-electronics devices.

     

Advanced classification approach for neuronal phoneme recognition system based on efficient constructive training algorithm

This paper introduces a neural network optimization procedure allowing the generation of multilayer perceptron (MLP) network topologies with few connections, low complexity and high classification performance for phoneme’s recognition. An efficient constructive algorithm with incremental training using a new proposed Frame by Frame Neural Networks (FFNN) classification approach for automatic phoneme recognition is thus proposed. It is based on a novel recruiting hidden neuron’s procedure for a single hidden-layer. After an initializing phase started with initial small number of hidden neurons, this algorithm allows the Neural Networks (NNs) to adjust automatically its parameters during the training phase. The modular FFNN classification method is then constructed and tested to recognize 5 broad phonetic classes extracted from the TIMIT database. In order to take into account the speech variability related to the coarticulation effect, a Context Window of Three Successive Frame’s (CWTSF) analysis is applied. Although, an important reduction of the computational training time is observed, this technique penalized the overall Phone Recognition Rate (PRR) and increased the complexity of the recognition system. To alleviate these limitations, two feature dimensionality reduction techniques respectively based on Principal Component Analysis (PCA) and Self Organizing Maps (SOM) are investigated. It is observed an important improvement in the performance of the recognition system when the PCA technique is applied. Optimal neuronal phone recognition architecture is finally derived according to the following criteria: best PRR, minimum computational training time and complexity of the BPNN architecture.     

State and output feedback fuzzy variable structure controllers for multivariable nonlinear systems subject to input nonlinearities

This paper presents three fuzzy adaptive controllers for a class of uncertain multivariable nonlinear systems with both sector nonlinearities and dead zones: two first controllers are state feedbacks and the last controller is an output feedback. The design of the first controller concerns systems with symmetric and positive definite control–gain matrix, while the second control design is extended to the case of nonsymmetric control–gain matrix thanks to an appropriate decomposition, namely the product of a symmetric positive definite matrix, a diagonal matrix with diagonal entries +1 or ?1, and a unity upper triangular matrix. The third controller is an output feedback extension of the second controller. In this controller, a high-gain observer is incorporated to estimate the unmeasurable states. An appropriate adaptive fuzzy logic system is used to reasonably approximate the uncertain functions. A Lyapunov approach is adopted to derive the parameter adaptation laws and prove the stability of those control systems as well as the exponential convergence of their underlying tracking errors within an adjustable region. The effectiveness of the proposed fuzzy adaptive controllers is illustrated through simulation results.     

Geometrically nonlinear analysis of elastoplastic behavior of functionally graded shells

Engineering with Computers - A geometrically nonlinear analysis of elastoplastic ceramic/metal functionally graded material (FGM) shells is investigated in this paper based on the first-order shear...