45 research outputs found

    A Study on the Synergy of Different Modes in MOOC for Teaching Chinese as a Foreign Language

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    Guided by the theoretical framework of dynamic multimodal discourse analysis, this study examines the synergy among different modes in the multimodal discourse of MOOC for TCFL (Teaching Chinese as a Foreign Language). For this purpose, this study has been carried out using qualitative research methods to analyze the video of HSK Standard Course Level 1 --- Lesson 1 in Confucius Institutes Online from the perspective of the context of culture, the context of situation and the synergy between various modes. The results of this study show that on the one hand, in order to achieve different communicative goals, teachers will choose different modes of multimodal discourse communication. On the other hand, in the whole process of communication, auditory mode is the main mode, which is always in the foreground. The visual mode formed by teachers will be in the foreground only when they complement the auditory mode and form the complementary relationship. However, In the process of presentation, auditory mode and the visual mode formed by background images are both in the foreground and play a significant role in helping students understand in the teaching

    Teacher Identity Construction in Teacher-Student Classroom Interactions

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    This study has been carried out using the qualitative method and conversation analysis approach to explore the discourse construction of the democratic and authoritarian status of English teachers in domestic high schools. Under the guidance of theoretical framework proposed by Chen Xingren (2013), two high school English classes from Teaching Video Network are analyzed in terms of question types, lexical characteristics, turn-takings and feedbacks. The results of this study show that in the classroom interactions,Teacher A builds up his democratic identity characteristics, while Teacher B turns up to behave authoritarian identity characteristics. This study analyzes two teachers’ conversational strategies in order to yield implications for teacher development as well as help them further understand the way of using conversational strategies to mobilize students’ initiative

    IDMA-Based MAC Protocol for Satellite Networks with Consideration on Channel Quality

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    In order to overcome the shortcomings of existing medium access control (MAC) protocols based on TDMA or CDMA in satellite networks, interleave division multiple access (IDMA) technique is introduced into satellite communication networks. Therefore, a novel wide-band IDMA MAC protocol based on channel quality is proposed in this paper, consisting of a dynamic power allocation algorithm, a rate adaptation algorithm, and a call admission control (CAC) scheme. Firstly, the power allocation algorithm combining the technique of IDMA SINR-evolution and channel quality prediction is developed to guarantee high power efficiency even in terrible channel conditions. Secondly, the effective rate adaptation algorithm, based on accurate channel information per timeslot and by the means of rate degradation, can be realized. What is more, based on channel quality prediction, the CAC scheme, combining the new power allocation algorithm, rate scheduling, and buffering strategies together, is proposed for the emerging IDMA systems, which can support a variety of traffic types, and offering quality of service (QoS) requirements corresponding to different priority levels. Simulation results show that the new wide-band IDMA MAC protocol can make accurate estimation of available resource considering the effect of multiuser detection (MUD) and QoS requirements of multimedia traffic, leading to low outage probability as well as high overall system throughput

    Spatio-Temporal Patterns and Impacts of Sediment Variations in Downstream of the Three Gorges Dam on the Yangtze River, China

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    Spanning the Yangtze River of China, the Three Gorges Dam (TGD) has received considerable concern worldwide with its potential impacts on the downstream side of the dam. This work investigated the spatio-temporal variations of suspended sediment concentration (SSC) at the downstream section of Yichang-to-Chenglingji from 2002 to 2015. A random forest model was developed to estimate SSC using MODIS ground reflectance products, and the spatio-temporal distributions of SSC were retrieved with this model to investigate the characteristics of water-silt variation. Our results revealed that, relatively, SSC before 2003 was evenly distributed in the downstream Yangtze River, while this spatial distribution pattern changed ce 2003 when the dam started storing water. Temporally, the SSC demonstrated a W-shaped curve of seasonal variation as one peak occurred in September and two troughs in March and November, and showed a significantly decreasing trend after three-stage impoundment. After official operation of the TGD in 2009, the SSC was reduced by over 40% than before 2003. Spatially, the most significant changes occurred in the upper Jingjiang section, where the SSC dropped by 45%. During all stages of impoundment, the water impoundment to 135 m in 2003 had the most significant impact on suspended sediment. The decreased SSC has led to emerging risks of bank failure, aggravated erosion of water front and aggressive down-cutting erosion along the downstream of the dam, as well as other ecological and environmental issues that require urgent attention by the government

    NLRP6 Serves as a Negative Regulator of Neutrophil Recruitment and Function During Streptococcus pneumoniae Infection

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    Streptococcus pneumoniae is an invasive pathogen with high morbidity and mortality in the immunocompromised children and elderly. NOD-like receptor family pyrin domain containing 6 (NLRP6) plays an important role in the host innate immune response against pathogen infections. Our previous studies have shown that NLRP6 plays a negative regulatory role in host defense against S. pneumoniae, but the underlying mechanism is still unclear. The further negative regulatory role of NLRP6 in the host was investigated in this study. Our results showed that NLRP6(-/-) mice in the lung had lower bacterial burdens after S. pneumoniae infection and expressed higher level of tight junction (TJ) protein occludin compared to WT mice, indicating the detrimental role of NLRP6 in the host defense against S. pneumoniae infection. Transcriptome analysis showed that genes related to leukocytes migration and recruitment were differentially expressed between wild-type (WT) and NLRP6 knockout (NLRP6(-/-)) mice during S. pneumoniae infection. Also, NLRP6(-/-) mice showed higher expression of chemokines including C-X-C motif chemokine ligand 1 (CXCL1) and 2 (CXCL2) and lower gene expression of complement C3a receptor 1 (C3aR1) and P-selectin glycoprotein ligand-1 (PSGL-1) which are the factors that inhibit the recruitment of neutrophils. Furthermore, NLRP6(-/-) neutrophils showed increased intracellular bactericidal ability and the formation of neutrophil extracellular traps (NETs) during S. pneumoniae infection. Taken together, our study suggests that NLRP6 is a negative regulator of neutrophil recruitment and function during S. pneumoniae infection. Our study provides a new insight to develop novel strategies to treat invasive pneumococcal infection

    AI is a viable alternative to high throughput screening: a 318-target study

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    : High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

    Parametric geometry modeling of flying wing UAV configuration integrated with intake and exhaust

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    Flying wing is a preferred configuration for unmanned combat air vehicle(UCAV),in which its airframe is highly integrated with intake and exhaust of propulsion system. To implement rapid geometric model of flying wing UCAV concept,a parametric geometry modeling method for flying wing UCAV configuration integrated with the intake and exhaust is proposed in this paper. Firstly,parametric models for configuration of the flying wing airframe and the intake and exhaust are established using class function/shape function. Then,the related geometry parameters between the flying wing airframe and the intake and exhaust are identified,and the correlative control rules are set to match airframe-propulsion interactions. 3D geometric models of the flying wing UCAV configuration are automatically generated by use of the parametric geometry model and CATIA API. Application examples indicate that flying wing UCAV configurations can automatically adjust its shape to match the different intake and exhaust concepts by use of the proposed method. The method can effectively improve efficiency for flying wing UCAV conceptual design

    Family Firms and Regional Development: Evidence from China

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    This chapter provides an overview of family business and regional development in the Chinese context. Motivated by the line of “contextualizing” family business studies, this chapter begins by discussing the Chinese context and regional development, and how these contribute to the unique challenges faced by Chinese family firms. The chapter discusses the historical development, current status, and future prospects of family firms in China. Finally, we conclude by exploring the theoretical and practical implications of this study and its limitations, which provide opportunities for future research aimed at extending knowledge about family business and regional development

    A Superhydrophobic Alkali Activated Materials Coating by Facile Preparation

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    Alkali activated materials (AAMs) were considered as economical and environmentally friendly that have attracted incrementally attention as green coating materials. However, alkali activated materials were inclined to be infiltrated and ruined by harmful ions in water due to their hydrophilicity. And the ordinary ways of construct superhydrophobic coatings were costly, complex and need fluorine material. The superhydrophobic surfaces were fragile owing to the super-hydrophobicity of materials were controlled to surface merely. In this work, a facile, convenient and economical strategy to synthesize alkali activated slag materials (AAS) superhydrophobic coatings with excellent water repellence was developed. Herein, the hydrolysis and polymerization of triethoxy (octyl)silane (TTOS) were applied for generating micro/nanostructures to construct a three-dimensional overall superhydrophobic alkali activated slag materials coating. The water contact angle (CA) about surfaces and bottoms of superhydrophobic alkali activated slag materials coatings were 150.2°, 152° and the water rolling angle (SA) of surfaces and bottoms were 5°, 4° respectively. Besides, the superhydrophobic alkali activated slag materials coatings demonstrated excellent mechanical abrasion effect that still maintain super-hydrophobicity after sandpaper abrasion stand. Super-hydrophobicity of coatings could be regenerated by simple sandpaper rubbing when they were attacked chemically. Concisely, the superhydrophobic alkali activated slag materials coatings were show the benefit of affordable and feasibility so that they have the potential for expandable industrial promotion

    Association of the androgens with COVID-19 prognostic outcomes: a systematic review

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    Abstract Objective The coronavirus disease 2019 was a global public health emergency in later years (from 2020 to early 2022), and androgens have been associated with infection and prognostic outcomes. However, the relationship between low serum testosterone levels and prognostic outcomes remains inconclusive. This systematic review aimed to investigate the relationship between serum testosterone levels and prognostic outcomes in patients with COVID-19. Methods We searched PubMed, MEDLINE, EMBASE and Web of Science electronic databases for all literature from January 1, 2020, to September 1, 2022. In addition, we also searched literature manually. The search terms were COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), androgens, and testosterone. There were no language restrictions for retrieval. Results Our search identified 2285 articles, resulting in a full-text analysis of 16 studies, including 12 cohort studies and four case-control studies. Low serum testosterone levels were observed to be statistically associated with a higher probability of intensive care unit (ICU) admission in seven studies. In eight studies, higher hospital mortality was associated with lower serum testosterone levels. Six studies found that low serum testosterone levels were associated with a statistically significant difference in lung function impairment. Only four studies found that among living patients, those with lower serum testosterone levels had longer hospital stays. All but one of the included studies had a low risk of bias. Conclusions Based on available data, low serum testosterone levels are associated with higher rates of ICU admission, hospital mortality, risk of lung failure, inflammatory markers, and longer hospital stays in patients with COVID-19 compared with those having normal serum testosterone levels
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