1,733 research outputs found
Studies of pathogenesis-related proteins in the strawberry plant: partial purification of a chitinase-containing protein complex and analysis of an osmotin-like protein gene
Plant chitinases and osmotin-like proteins (OLPs) are both pathogenesis-related (PR) proteins, which are implicated in plant responses to pathogen attacks and environmental stresses. In this dissertation, a chitinase-containing protein complex was purified to near homogeneity from strawberry leaf extracts. This protein complex contained at least five different chitinase molecules as revealed by activity gel assays. A previous study showed that winter rye leaves contain seven protein complexes, which consist of various combinations of a chitinase, two glucanase-like proteins (GLPs) and a thaumatin-like protein (TLP). Western blot analysis of the strawberry chitinase complex, however, did not detect the presence of any GLP or TLP in the complex. The second part of this dissertation research dealt with studies of strawberry OLP genes. A genomic clone containing an OLP gene, designated FaOLP2, was isolated and completely sequenced. FaOLP2 contains no intron, and has a potential to encode a precursor protein of 229 amino acid residues with a 27-amino acid signal peptide at the N-terminus. Southern blot analysis showed that FaOLP2 represents a small multi-gene family. The expression of FaOLP2 in different strawberry organs was analyzed using real-time PCR. The result showed that FaOLP2 expressed at different levels in leaves, crowns, roots, green fruits and ripe red fruits. Furthermore, the expression of FaOLP2 under different abiotic stresses was analyzed at different time points. All of the three tested abiotic stimuli, abscisic acid, salicylic acid and mechanical wounding, triggered significant induction of FaOLP2 within 2-6 h post-treatment. Comparing the three stimuli, FaOLP2 was more prominently induced by salicylic acid than by abscisic acid or mechanical wounding. The positive responses of FaOLP2 to these stress factors suggested that FaOLP2 may be involved in the protection of strawberry against pathogen attacks and against osmotic-related stresses. In addition to FaOLP2, the expression of a previously cloned OLP gene (FaOLP1) upon fungal infection was examined at different time points post-infection. Each of the two tested fungal species, Colletotrichum fragariae and Colletotrichum acutatum, triggered a substantial induction of FaOLP1 at 24-48 h post-inoculation, indicating that FaOLP1 could be involved in strawberry defense against fungal infection
Distributed Relay Selection for Heterogeneous UAV Communication Networks Using A Many-to-Many Matching Game Without Substitutability
This paper proposes a distributed multiple relay selection scheme to maximize
the satisfaction experiences of unmanned aerial vehicles (UAV) communication
networks. The multi-radio and multi-channel (MRMC) UAV communication system is
considered in this paper. One source UAV can select one or more relay radios,
and each relay radio can be shared by multiple source UAVs equally. Without the
center controller, source UAVs with heterogeneous requirements compete for
channels dominated by relay radios. In order to optimize the global
satisfaction performance, we model the UAV communication network as a
many-to-many matching market without substitutability. We design a potential
matching approach to address the optimization problem, in which the optimizing
of local matching process will lead to the improvement of global matching
results. Simulation results show that the proposed distributed matching
approach yields good matching performance of satisfaction, which is close to
the global optimum result. Moreover, the many-to-many potential matching
approach outperforms existing schemes sufficiently in terms of global
satisfaction within a reasonable convergence time.Comment: 6 pages, 4 figures, conferenc
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Evaluating the Scalability of SDF Single-chip Multiprocessor Architecture Using Automatically Parallelizing Code
Advances in integrated circuit technology continue to provide more and more transistors on a chip. Computer architects are faced with the challenge of finding the best way to translate these resources into high performance. The challenge in the design of next generation CPU (central processing unit) lies not on trying to use up the silicon area, but on finding smart ways to make use of the wealth of transistors now available. In addition, the next generation architecture should offer high throughout performance, scalability, modularity, and low energy consumption, instead of an architecture that is suitable for only one class of applications or users, or only emphasize faster clock rate. A program exhibits different types of parallelism: instruction level parallelism (ILP), thread level parallelism (TLP), or data level parallelism (DLP). Likewise, architectures can be designed to exploit one or more of these types of parallelism. It is generally not possible to design architectures that can take advantage of all three types of parallelism without using very complex hardware structures and complex compiler optimizations. We present the state-of-art architecture SDF (scheduled data flowed) which explores the TLP parallelism as much as that is supplied by that application. We implement a SDF single-chip multiprocessor constructed from simpler processors and execute the automatically parallelizing application on the single-chip multiprocessor. SDF has many desirable features such as high throughput, scalability, and low power consumption, which meet the requirements of the next generation of CPU design. Compared with superscalar, VLIW (very long instruction word), and SMT (simultaneous multithreading), the experiment results show that for application with very little parallelism SDF is comparable to other architectures, for applications with large amounts of parallelism SDF outperforms other architectures
(2,2′-Bipyridine-κ2 N,N′){N-[(2-oxidonaphthalen-1-yl-κO)methylÂidene]-l-valinato-κO}copper(II) trihydrate
In the title complex, [Cu(C16H15NO3)(C10H8N2)]·3H2O, the CuII atom is five coordinated by O,N,O′-donor atoms of the Schiff base ligand and by two N atoms of the 2,2′-bipyridine ligand in a distorted square-pyramidal geometry. In the crystal, molÂecules are linked into a two-dimensional network parallel to (011) by O—H⋯O hydrogen bonds
On sign-changing solutions for nonlinear operator equations
AbstractIn this paper, the existence of sign-changing solutions for nonlinear operator equations is discussed by using the topological degree and fixed point index theory. The main theorems are some new three-solution theorems which are different from the famous Amann's and Leggett-Williams' three-solution theorems as well as the results in [F. Li, G. Han, Generalization for Amann's and Leggett–Williams' three-solution theorems and applications, J. Math. Anal. Appl. 298 (2004) 638–654]. These three solutions are all nonzero. One of them is positive, another is negative, and the third one is a sign-changing solution. Furthermore, the theoretical results are successfully applied to both integral and differential equations
Margin-Based Few-Shot Class-Incremental Learning with Class-Level Overfitting Mitigation
Few-shot class-incremental learning (FSCIL) is designed to incrementally
recognize novel classes with only few training samples after the (pre-)training
on base classes with sufficient samples, which focuses on both base-class
performance and novel-class generalization. A well known modification to the
base-class training is to apply a margin to the base-class classification.
However, a dilemma exists that we can hardly achieve both good base-class
performance and novel-class generalization simultaneously by applying the
margin during the base-class training, which is still under explored. In this
paper, we study the cause of such dilemma for FSCIL. We first interpret this
dilemma as a class-level overfitting (CO) problem from the aspect of pattern
learning, and then find its cause lies in the easily-satisfied constraint of
learning margin-based patterns. Based on the analysis, we propose a novel
margin-based FSCIL method to mitigate the CO problem by providing the pattern
learning process with extra constraint from the margin-based patterns
themselves. Extensive experiments on CIFAR100, Caltech-USCD Birds-200-2011
(CUB200), and miniImageNet demonstrate that the proposed method effectively
mitigates the CO problem and achieves state-of-the-art performance
Fatigue evaluation of metallic components based on chaotic characteristics of second harmonic generation signal
In the nonlinear ultrasonic technique, the nonlinear received signal, such as second harmonic generation (SHG) signal in higher harmonic experiments, is complicated and non-stationary time series which reflects the fatigue damage of metal components. To effectively evaluate the fatigue damage of metal components, especially the earlier fatigue damage, the chaos and fractal theory are proposed to analyze the received signal of higher harmonic experiments. Chaotic characteristics, for example Lyapunov exponent, correlation dimension and Kolmogorov entropy, are extracted to evaluate the fatigue damage. Experiments results indicate that chaotic characteristics can reasonably characterize and evaluate the fatigue state of beams, which the variation trend of chaotic characteristics has a close relationship with fatigue crack propagation. Furthermore, chaotic characteristics are very sensitive to earlier fatigue damage of used connecting rods, especially the Lyapunov exponent. Therefore, chaos and fractal theory could effectively extract the nonlinear received signals, and chaotic characteristics could reasonably evaluate the fatigue damage state of metal components
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