181 research outputs found

    Reflections on Education Groups at Basic Education Level in China

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    In the context of China’s education reform, the education group emerges as a new form of school organization designed to equalize access to high-quality educational resources. While this increasingly popular mode of school running has achieved notable results in Beijing, Shanghai, and Hangzhou, among other cities, there are concerns about the problems it engenders, such as severe homogenization and poor group management. The purpose of this paper is to examine the causes, outcomes, and problems of education groups and to propose solutions to existing problems, as well as to provide references for future school alliance development

    Protocol-Guided Teaching: An Experiment in Chinese Basic Education

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    Protocol-guided teaching, a method of classroom instruction reform started by Donglu Middle School in Nanjing of China has developed into a student-centered teaching model in the context of the deepening reform of Chinese basic education. In this model, the teacher plays an essential guiding role, and the main objective is the development of the student’s autonomous learning ability. The purpose of this article is to increase interest in and conversations about the protocol-guided teaching model among educational professionals by describing the history of the approach, summarizing its features, and highlighting its implementation tactics

    Image Description using Radial Associated Laguerre Moments

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    This study proposes a new set of moment functions for describing gray-level and color images based on the associated Laguerre polynomials, which are orthogonal over the whole right-half plane. Moreover, the mathematical frameworks of radial associated Laguerre moments (RALMs) and associated rotation invariants are introduced. The proposed radial Laguerre invariants retain the basic form of disc-based moments, such as Zernike moments (ZMs), pseudo-Zernike moments (PZMs), Fourier-Mellin moments (OFMMs), and so on. Therefore, the rotation invariants of RALMs can be easily obtained. In addition, the study extends the proposed moments and invariants defined in a gray-level image to a color image using the algebra of quaternion to avoid losing some significant color information. Finally, the paper verifies the feature description capacities of the proposed moment function in terms of image reconstruction and invariant pattern recognition accuracy. Experimental results confirmed that the associated Laguerre moments (ALMs) perform better than orthogonal OFMMs in both noise-free and noisy conditions

    Optical polarization rogue waves from supercontinuum generation in zero dispersion fiber pumped by dissipative soliton

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    Optical rogue waves emerge in nonlinear optical systems with extremely large amplitudes, and leave without a trace. In this work, we reveal the emergence of optical polarization rogue waves in supercontinuum generation from a zero-dispersion fiber, pumped by a dissipative soliton laser. Flat spectral broadening is achieved by modulation instability, followed by cascaded four-wave-mixing. In this process, we identify the emergence of optical polarization rogue waves, based on the probability density function of the relative distance among polarization states. Experimental results show that optical polarization rogue waves originate from vector multi-wave-mixing. Besides, we observe double peaks, and even triple peaks in the histogram of the state of polarization. This is a new and intriguing property, never observed so far in optical rogue waves, for example those emerging in the statistics of pulse intensities. Our polarization domain statistical analysis provides a new insight into the still debated topic of the mechanism for rogue wave generation in optical supercontinuum

    Experimental revealing of asynchronous transient-soliton buildup dynamics

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    The buildup process of coherent structures and patterns from the composite balance between conservative and dissipative effects is a universal phenomenon that occurs in various areas of physics, ranging from quantum mechanics to astrophysics. Dissipative solitons are highly coherent solutions of nonlinear wave equations, and provide an excellent research platform for ultrafast transient phenomena. Herein, by taking advantage of the fast detection technique provided by the dispersive Fourier transform, we experimentally observe the spectral broadening and breathing behavior of transient dissipative structures produced asynchronously during the buildup process of dissipative solitons. These observations unveil a novel dynamics of dissipative soliton generation, which is accompanied by energy quantization, self-phase modulation induced spectral broadening, structural dissipative soliton formation, and Raman soliton self-frequency shifting, thus providing a new insight in transient ultrafast laser dynamics

    PSAT1 prompted cell proliferation and inhibited cell apoptosis in multiple myeloma through regulating PI3K/AKT pathway

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    Purpose: To identify the biological function of phosphoserine aminotransferase 1 (PSAT1) in regulating cell proliferation and apoptosis in multiple myeloma (MM).Methods: The mRNA and protein levels of PSAT1 were determined using quantitative real-time polymerase chain reaction (PCR) and western blotting, respectively. Cell proliferation was measured using CCK-8 assay.Results: PSAT1 mRNA and protein expression levels were significantly increased in MM cell lines when compared to control cells. Moreover,  downregulation of PSAT1 inhibited MM cell proliferation and induced cell apoptosis, whereas overexpression of PSAT1 promoted MM cell  proliferation and suppressed cell apoptosis. Further analysis demonstrated that the underlying mechanism was via regulation of PI3K/AKT pathway.Conclusion: The results identified a novel role for PSAT1 in the progression of MM, which may provide a therapeutic and a new anticancer target for the therapy of MM. Keywords: Multiple myeloma, PSAT1, Cell proliferation, PI3K/AKT pathwa

    AAV2/8-hSMAD3 gene delivery attenuates aortic atherogenesis, enhances Th2 response without fibrosis, in LDLR-KO mice on high cholesterol diet

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    BACKGROUND: Inflammation is a key etiologic component in atherogenesis and transforming growth factor beta 1 (TGFβ1) is a well known anti-inflammatory cytokine which potentially might be used to limit it. Yet TGFβ1 is pleiomorphic, causing fibrosis, cell taxis, and under certain circumstances, can even worsen inflammation. SMAD3 is an important member of TGFβ1′s signal transduction pathway, but is a fully intracellular protein. OBJECTIVES: With the hope of attenuating TGFβ1′s adverse systemic effects (eg. fibrosis) and accentuating its anti-inflammatory activity, we proposed the use of human (h)SMAD3 as an intracellular substitute for TGFβ1. STUDY DESIGN: To test this hypothesis adeno-associated virus type 2/8 (AAV)/hSMAD3 or AAV/Neo (control) was tail vein injected into the low density lipoprotein receptor knockout (LDLR-KO) mice, then placed on a high-cholesterol diet (HCD). RESULTS: The hSMAD3 delivery was associated with significantly lower atherogenesis as measured by larger aortic cross sectional area, thinner aortic wall thickness, and lower aortic systolic blood velocity compared with Neo gene-treated controls. HSMAD3 delivery also resulted in fewer aortic macrophages by immunohistochemistry for CD68 and ITGAM, and quantitative reverse transcriptase polymerase chain reaction analysis of EMR and ITGAM. Overall, aortic cytokine expression showed an enhancement of Th2 response (higher IL-4 and IL-10); while Th1 response (IL-12) was lower with hSMAD3 delivery. While TGFβ1 is often associated with increased fibrosis, AAV/hSMAD3 delivery exhibited no increase of collagen 1A2 or significantly lower 2A1 expression in the aorta compared with Neo-delivery. Connective tissue growth factor (CTGF), a mediator of TGFβ1/SMAD3-induced fibrosis, was unchanged in hSMAD3-delivered aortas. In the liver, all three of these genes were down-regulated by hSMAD3 gene delivery. CONCLUSION: These data strongly suggest that AAV/hSMAD3 delivery gave anti-atherosclerosis therapeutic effect without the expected undesirable effect of TGFβ1-associated fibrosis
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