302 research outputs found

    Neural Back-Stepping Control of Hypersonic Flight Vehicle with Actuator Fault

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    This paper addresses the fault-tolerant control of hypersonic flight vehicle. To estimate the unknown function in flight dynamics, neural networks are employed in controller design. Moreover, in order to compensate the actuator fault, an adaptive signal is introduced in the controller design to estimate the unknown fault parameters. Simulation results demonstrate that the proposed approach could obtain satisfying performance

    Nanosecond pulsed electric field inhibits malignant melanoma growth by inducing the change of systemic immunity

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    Nanosecond pulsed electric fields (nsPEFs) showed an inhibitory effect on proliferation of malignant melanoma. In this study, the growth of melanoma were inhibited by changing the systemic immunity. C57BL/6 mice with B16 malignant were exposed to 200 pulses of 100 ns duration, 30kV/cm. The mice were executed four days later. T lymphocyte has been extracted from spleen. Cell viability was evaluated by CCK-8 assay. CD3+CD4+ T cells, CD3+CD8+ T cells, regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) were analyzed by flow cytometry. TNF-?, IL-2, IL-10, TGF-?, IFN? ? levels in supernatants were assessed by ELISA. C57 malignant melanoma model were established successfully. After the treatment of nsPEFs(30 kV/cm 100 ns 200p), the numbers of T lymphocytes were increased.CD3+ CD4+ T cells changed from 48% to 51.2%;CD3+CD8+T lymphocytes increased from 39.6% to 40.4%.Treg cells reduced from 4.3% to 2.4%,MDSC decreased by 39.0% to 19.7% . In addition, the level of TNF-?, IL-2 were increased (P0.05). Tumor growth can be effectively inhibited by nsPEFs in vivo, which activate targets of immune respones, accumulation of inflammatory cells and immune cytokines

    Newcomers’ relationship-building behavior, mentor information sharing and newcomer adjustment: The moderating effects of perceived mentor and newcomer deep similarity

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    Drawing on similarity-attraction theory, we propose that relationship-building behaviors from newcomers are more positively related to information-sharing behaviors from mentors when they perceive a deep similarity with the newcomers, and that mentors' information sharing is likely to be well received by newcomers when they perceive a deep similarity with their mentors. We also hypothesize that newcomers' perceived mentor information sharing is positively associated with newcomer adjustment (i.e., role clarity and job performance). A time-lagged study with a total of 99 newcomers and their mentors was conducted within three months of newcomers entering the company. The results support our hypotheses, suggesting that perceived deep similarity is a key factor that associates with the effectiveness of newcomers' proactivity and mentors' information sharing behavior in newcomer adjustment

    Role of MicroRNA-26b in Glioma Development and Its Mediated Regulation on EphA2

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    BACKGROUND: MicroRNAs (miRNAs) are short, non-coding RNAs that regulate the expression of multiple target genes. Deregulation of miRNAs is common in human tumorigenesis. Low level expression of miR-26b has been found in glioma cells. However, its underlying mechanism of action has not been determined. METHODOLOGY/PRINCIPAL FINDINGS: Real-time PCR was employed to measure the expression level of miR-26b in glioma patients and cells. The level of miR-26b was inversely correlated with the grade of glioma. Ectopic expression of miR-26b inhibited the proliferation, migration and invasion of human glioma cells. A binding site for miR-26b was identified in the 3'UTR of EphA2. Over-expression of miR-26b in glioma cells repressed the endogenous level of EphA2 protein. Vasculogenic mimicry (VM) experiments were performed to further confirm the effects of miR-26b on the regulation of EphA2, and the results showed that miR-26b inhibited the VM processes which regulated by EphA2. SIGNIFICANCE: This study demonstrated that miR-26b may act as a tumor suppressor in glioma and it directly regulates EphA2 expression. EphA2 is a direct target of miR-26b, and the down-regulation of EphA2 mediated by miR-26b is dependent on the binding of miR-26b to a specific response element of microRNA in the 3'UTR region of EphA2 mRNA

    What cultural values determine student self-efficacy? An empirical study for 42 countries and economies

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    Self-efficacy is a vital personal characteristic for student success. However, the challenge of cross-cultural comparisons remains as scalar invariance is hard to be satisfied. Also, it is unclear how to contextually understand student self-efficacy in light of cultural values in different countries. This study implements a novel alignment optimization method to rank the latent means of student self-efficacy of 308,849 students in 11,574 schools across 42 countries and economies that participated in the 2018 Program in International Student Assessment. We then used classification and regression trees to classified countries with differential latent means of student self-efficacy into groups according to Hofstede’s six cultural dimensions theory. The results of the alignment method recovered that Albania, Colombia, and Peru had students with the highest mean self-efficacy, while Slovak Republic, Moscow Region (RUS), and Lebanon had the lowest. Moreover, the CART analysis indicated a low student self-efficacy for countries presenting three features: (1) extremely high power distance; (2) restraint; and (3) collectivism. These findings theoretically highlighted the significance of cultural values in shaping student self-efficacy across countries and practically provided concrete suggestions to educators on which countries to emulate such that student self-efficacy could be promoted and informed educators in secondary education institutes on the international expansion of academic exchanges

    Demographic strategies of a dominant tree species in response to logging in a degraded subtropical forest in Southeast China

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    International audienceAbstractKey messageThe demography of pioneer tree species (Pinus massonianaLamb.) is significantly affected by logging in Southeast China. Logging negatively affects the population growth rate ofP. massoniana, which facilitates the growth of individual trees but has no effect on reproduction probability. The survival and growth of seedlings contribute the most to population growth.ContextSubtropical forest degradation caused by unreasonable disturbances is closely related to anthropogenic activities in Southeast China, and the frequent small-scale logging activity by local people was the dominated disturbance regime in forests in this region over the past several decades.AimsThe objective of this study is to evaluate the demographic consequences of logging on Pinus massoniana, a pioneer tree species, at individual level (survival, growth, and fecundity) and population level (the population growth rate and size distribution) over short-term period.MethodsThe size of tree individuals was combined with vital rates using various modeling approaches based on demographic data from three annual censuses. The integral projection model (IPM) was constructed and used to conduct comparative demographic analyses.ResultsLogging negatively affected the population growth rate: from a slight expansion before logging to a moderate decline after logging. This study found a significant reduction in seedling recruitment after logging, and plant growth and mortality were slightly enhanced. The survival of seedlings greatly contributes to population growth rate compared to other life stages for both periods (before and after logging) while its relative importance decreases after logging. Seedling growth is also important to population growth, and its relative importance increased after logging. Shrinkage and fecundity have a minimal contribution effect on the population growth rate.ConclusionGrowing plants in a nursery with a similar demography to P. massoniana could be beneficial for pioneer species regeneration in that this will improve the survival rate and growth of small individuals after logging

    1-(4-Amino­phen­yl)-3-[2-(trifluoro­meth­yl)phen­yl]prop-2-en-1-one

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    The title compound, C16H12F3NO, a derivative of biologically active chalcones, comprises two benzene rings and a central –CH=CH—C(=O)– unit. The dihedral angle between the two rings is 10.9 (1)° and the mol­ecule adopts an E configuration about the central olefinic bond. The crystal structure is stabilized by inter­molecular N—H⋯O and N—H⋯N hydrogen bonds

    Shape from perspective trihedral angle constraint

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    Abstract: This paper defines and investigates a fundamental problem of determining the position and orientation of a 3 0 object using $ingle perspective i m g e view. The technique is based on the interpretation of trihedral angle constraid informution. A new closed form solution io the problem is proposed. The method also provides a general analytic technique for dealing with a class of problem of shape from inverse perspective projection by using "Angle to Angle Correspondence Information ". Simulation experiments show that our method is enective and robust for real application. t This research ispariially supported by ONR NooO14-91-J1306
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