547 research outputs found

    The sensitivity analysis of the translation and the rotation angle of the first-order mode shape of the joints in frame structures

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    When damage occurs, there are changes in the structural stiffness. This causes changes in the vibrational information, such as translation and rotation angle of the joints in the structure. This paper presents a sensitivity study of translation and slope of the first-order mode shape of the joints in the frame structure, and which will contribute to structural damage identification further. Starting from the equation of natural vibration of frame structure, and according to the characteristics of the stiffness matrix, derive sensitivity coefficient expression of translation and slope of first-order mode shape of the joints in the structure, and obtain the first-order relative sensitivity coefficient of the first story is always smaller than zero when single column of the first story damage occurs. The numerical analysis of the four stories three spans frame shows consistent results with the formula derivation

    A Type of Delay Feedback Control of Chaotic Dynamics in a Chaotic Neural Network

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    A chaotic neural network consisting of chaotic neurons exhibits such rich dynamical behaviors as nonperiodic associative memory. But it is difficult to distinguish the stored patterns from others, since the chaotic neural network shows chaotic wandering around the stored patterns. In order to apply the nonperiodic associative memory to information search or pattern identification, it is necessary to control chaotic dynamics. In this paper, we propose a delay feedback control method for the chaotic neural network. Computer simulation shows that, by means of the control method, the chaotic dynamics in the chaotic neural network are changed. The output sequence of the controlled network wanders around one stored pattern and its reverse pattern

    Visual Cortex Inspired CNN Model for Feature Construction in Text Analysis

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    Recently, biologically inspired models are gradually proposed to solve the problem in text analysis. Convolutional neural networks (CNN) are hierarchical artificial neural networks, which include a various of multilayer perceptrons. According to biological research, CNN can be improved by bringing in the attention modulation and memory processing of primate visual cortex. In this paper, we employ the above properties of primate visual cortex to improve CNN and propose a biological-mechanism-driven-feature-construction based answer recommendation method (BMFC-ARM), which is used to recommend the best answer for the corresponding given questions in community question answering. BMFC-ARM is an improved CNN with four channels respectively representing questions, answers, asker information and answerer information, and mainly contains two stages: biological mechanism driven feature construction (BMFC) and answer ranking. BMFC imitates the attention modulation property by introducing the asker information and answerer information of given questions and the similarity between them, and imitates the memory processing property through bringing in the user reputation information for answerers. Then the feature vector for answer ranking is constructed by fusing the asker-answerer similarities, answerer's reputation and the corresponding vectors of question, answer, asker and answerer. Finally, the Softmax is used at the stage of answer ranking to get best answers by the feature vector. The experimental results of answer recommendation on the Stackexchange dataset show that BMFC-ARM exhibits better performance

    A Perplexing Case of a DUOX2 Mutation and Graves’ Disease

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    It is commonly accepted that DUOX2 mutations may cause congenital hypothyroidism and thyrotropin resistance, thus its combination with Graves' disease would be unusual. In this case, our patient's serum thyroid function tests suggested a high probability of thyroid hormone resistance syndrome, but genetic testing did not suggest gene mutations of THRα or THRβ. This is a rare case report of thyroid hormone resistance

    A CIRCULATION DYNAMICS MODEL IN THE ECOSYSTEM FOR THE WEST LAKE, HANGZHOU

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    This paper focuses the researches on an eutrophication model after drainage of wastewater and drawing water from the Qiantang River to West Lake. The model describes the circulation of nutritive matters (such as phosphorus, nitrogen, and carbon) in the ecosystem of the Lake. The model was established according to observed values of water quality and relevant parameters in 1995. The results of model calibration and verification show that the model can reasonably respond to the changes of forcing functions for drawing quantity and temperature of water. The model has been used to forecast the water quality in different drawing quantities. The predictions given by the model are also believed to be useful to comprehensively harness the West Lake.Article信州大学理学部附属諏訪臨湖実験所報告 11: 87-98(1999)departmental bulletin pape

    A Review of the Role of Natural Clay Minerals as Effective Adsorbents and an Alternative Source of Minerals

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    The minerals with unique properties such as natural clay minerals (NCMs) have promising approach in environmental and industrial sphere. In fact, under some specific conditions the NCMs could be used either as effective adsorbent material or alternative source of minerals. This chapter presents an outline of a general review of factors that affect the application ability of NCMs and a descriptive analysis of NH4+ and REE adsorption behavior and extraction of rare earth elements (REE) by an ion-exchange with NH4+ ions onto NCMs. Clays and NCMs both effectively remove various contaminants from aqueous solution and serve as alternative sources of minerals, as extensively discussed in this chapter. This review compiles thorough literature of current research and highlights the key findings of adsorption (NH4+ and REE) that use different NCMs as adsorbents or alternative sources of minerals (i.e., REE). The review confirmed that NCMs excellently remove different cations pollutants and have significant potential as alternative source of REE. However, modification and further development of NCMs applications for getting the best adsorption and the best extraction of REE onto NCMs, which would enhance pollution control and leaching system is still needed

    Cultivation modes impacting root microbiomes and metabolites in medicinal orchid Dendrobium denneanum

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    IntroductionThe plant microbiome is the second genome of plants and is important for plant growth and health. Dendrobium is an epiphytic herbal plant of the family Orchidaceae that is often found attached to tree trunks or rocks and exhibits different cultivation modes. Microbiological and metabolite studies of Dendrobium denneanum Kerr (D. denneanum) in different cultivation modes can reveal important relationships between Dendrobium spp., their microbiomes, and their pharmacological substances, which is important for sustainable agricultural development and human health, particularly in the study of medicinal plants.MethodsIn this study, three cultivation modes, living tree epiphytic (LT), stone epiphytic (SE), and pot cultivation (PO) of D. denneanum in the same environment were selected, and the metabolites were using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Subsequently, differential metabolites were screened, the rhizosphere and root endosphere microorganisms were sequenced via high-throughput sequencing, and the 16S rRNA gene/ITS sequences were obtained.ResultsThe main microbial taxa in the rhizosphere and root endosphere of D. denneanum included bacteria belonging to Proteobacteria, Actinobacteria, and Actinobacteria, and the fungi Basidiomycota and Ascomycota, whose abundances varied in different cultivation modes. Soil properties affect the composition of D. denneanum metabolites and root microbiome, among which, soil total phosphorus (TP) and pH in particular are important factors for soil microorganisms. Studies of root microbial communities have shown that root endosphere fungi are similar to rhizosphere fungi with microbial enrichment occurring from the external environment to the internal structures. Root microbial communities and metabolites correlation analyses revealed significant correlations between rhizosphere microbes, as well as endophytes and metabolites. For example, the rhizosphere bacterium genus Occallatibacter and root endosphere fungus Clonostachys showed a significant negative correlation with the pharmacodynamic substance gigantol in D. denneanum (P<0.05).ConclusionThis study elucidates the effects of different cultivation modes on D. denneanum from the perspective of microorganisms and metabolites, and investigates the effects of root microorganisms on metabolites. The findings enhance the current understanding of root microorganisms in orchid plants and provide a theoretical basis for the cultivation of Dendrobium spp., represented here by D. denneanum

    Repression of Esophageal Neoplasia and Inflammatory Signaling by Anti-miR-31 Delivery In Vivo.

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    BACKGROUND: Overexpression of microRNA-31 (miR-31) is implicated in the pathogenesis of esophageal squamous cell carcinoma (ESCC), a deadly disease associated with dietary zinc deficiency. Using a rat model that recapitulates features of human ESCC, the mechanism whereby Zn regulates miR-31 expression to promote ESCC is examined. METHODS: To inhibit in vivo esophageal miR-31 overexpression in Zn-deficient rats (n = 12-20 per group), locked nucleic acid-modified anti-miR-31 oligonucleotides were administered over five weeks. miR-31 expression was determined by northern blotting, quantitative polymerase chain reaction, and in situ hybridization. Physiological miR-31 targets were identified by microarray analysis and verified by luciferase reporter assay. Cellular proliferation, apoptosis, and expression of inflammation genes were determined by immunoblotting, caspase assays, and immunohistochemistry. The miR-31 promoter in Zn-deficient esophagus was identified by ChIP-seq using an antibody for histone mark H3K4me3. Data were analyzed with t test and analysis of variance. All statistical tests were two-sided. RESULTS: In vivo, anti-miR-31 reduced miR-31 overexpression (P = .002) and suppressed the esophageal preneoplasia in Zn-deficient rats. At the same time, the miR-31 target Stk40 was derepressed, thereby inhibiting the STK40-NF-κΒ-controlled inflammatory pathway, with resultant decreased cellular proliferation and activated apoptosis (caspase 3/7 activities, fold change = 10.7, P = .005). This same connection between miR-31 overexpression and STK40/NF-κΒ expression was also documented in human ESCC cell lines. In Zn-deficient esophagus, the miR-31 promoter region and NF-κΒ binding site were activated. Zn replenishment restored the regulation of this genomic region and a normal esophageal phenotype. CONCLUSIONS: The data define the in vivo signaling pathway underlying interaction of Zn deficiency and miR-31 overexpression in esophageal neoplasia and provide a mechanistic rationale for miR-31 as a therapeutic target for ESCC
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