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51.
This study focused on the relationship between perceptions of an innovative environment and creative performance in a web-based synchronous environment. A total of 160 sophomores and juniors from the National Taiwan Normal University participated in a learning activity consisting of a pretest and posttest quasi-experimental design. Pearson’s correlation coefficients and analysis of covariance (ANCOVA) were used in data analysis. Results indicated a positive correlation between personal creative performance and a free, supportive, and innovative environment. Team support and organizational obstruction had less influence on personal creative performance. Compared with a traditional classroom, a synchronous environment added to innovative essence and helped learners do better in terms of novelty, feasibility, value, and creative product design overall. 相似文献
52.
This study examined how operating elderly or young avatars affected shoppers’ product perceptions and purchasing behaviors. It also investigated how virtual shopping experiences translated into prosocial behavior regarding a nonprofit organization supporting the elderly. Operating elderly avatars influenced shoppers’ product choice and walking speed while shopping compared to operating younger avatars. In addition, operating elderly avatars positively affected participants’ attitudes and willingness to donate to and volunteer for a nonprofit organization supporting the elderly. Statistical interactions between avatar age and a shopper’s ageism on behavioral and persuasion outcomes were also confirmed, and these findings implied an assimilation/contrast effect influenced by a shopper’s preexisting prejudices toward the elderly. 相似文献
53.
Jianghong Liu Sophie R. Zhao Teresa Reyes 《International journal of molecular sciences》2015,16(8):18129-18148
In recent years, a role for epigenetic modifications in the pathophysiology of disease has received significant attention. Many studies are now beginning to explore the gene–environment interactions, which may mediate early-life exposure to risk factors, such as nutritional deficiencies and later development of behavioral problems in children and adults. In this paper, we review the current literature on the role of epigenetics in the development of psychopathology, with a specific focus on the potential for epigenetic modifications to link nutrition and brain development. We propose a conceptual framework whereby epigenetic modifications (e.g., DNA methylation) mediate the link between micro- and macro-nutrient deficiency early in life and brain dysfunction (e.g., structural aberration, neurotransmitter perturbation), which has been linked to development of behavior problems later on in life. 相似文献
54.
Persisters are drug-tolerant bacteria that account for the majority of bacterial infections. They are not mutants, rather, they are slow-growing cells in an otherwise normally growing population. It is known that the frequency of persisters in a population is correlated with the number of toxin–antitoxin systems in the organism. Our previous work provided a mechanistic link between the two by showing how multiple toxin–antitoxin systems, which are present in nearly all bacteria, can cooperate to induce bistable toxin concentrations that result in a heterogeneous population of slow- and fast-growing cells. As such, the slow-growing persisters are a bet-hedging subpopulation maintained under normal conditions. For technical reasons, the model assumed that the kinetic parameters of the various toxin–antitoxin systems in the cell are identical, but experimental data indicate that they differ, sometimes dramatically. Thus, a critical question remains: whether toxin–antitoxin systems from the diverse families, often found together in a cell, with significantly different kinetics, can cooperate in a similar manner. Here, we characterize the interaction of toxin–antitoxin systems from many families that are unrelated and kinetically diverse, and identify the essential determinant for their cooperation. The generic architecture of toxin–antitoxin systems provides the potential for bistability, and our results show that even when they do not exhibit bistability alone, unrelated systems can be coupled by the growth rate to create a strongly bistable, hysteretic switch between normal (fast-growing) and persistent (slow-growing) states. Different combinations of kinetic parameters can produce similar toxic switching thresholds, and the proximity of the thresholds is the primary determinant of bistability. Stochastic fluctuations can spontaneously switch all of the toxin–antitoxin systems in a cell at once. The spontaneous switch creates a heterogeneous population of growing and non-growing cells, typical of persisters, that exist under normal conditions, rather than only as an induced response. The frequency of persisters in the population can be tuned for a particular environmental niche by mixing and matching unrelated systems via mutation, horizontal gene transfer and selection. 相似文献
55.
采用系统建模及仿真方法搭建了一种典型载人航天器环热控一体化系统模型,分析了系统的性能。针对3人7天载人飞行工况开展了仿真分析,结果表明,经过合理设计,该系统可将舱内温湿度、压力、氧分压等参数控制在航天医学指标要求范围内。环热控系统仿真结果较好地预测了系统工作过程,显示了主要参数的变化情况,结果合理,验证了仿真方法、系统仿真模型的正确性。通过控制流体回路外回路旁通阀门开度,可准确控制外回路控温点温度,保证舱内温湿度在合理范围之内。此外,外回路控温点的设定会对环热控系统状态带来影响,通过合理设计外回路控温点,可保证舱内温湿度满足航天医学指标要求。 相似文献
56.
紫金山露天矿采用多种开拓运输方式,设备大型化、机械化程度较高,但采矿生产过程存在机械设备作业范围大、作业面广、作业点多的特征,安全管理、生产管理形势严峻。本文立足紫金山生产模式,针对该矿智能卡车调度系统的建设,提出进一步完善卡调系统运行管理、提高露采数字化管控水平的措施,旨在充分发挥卡调系统对生产的智能辅助,提升露天采矿安全管理、生产管理、资源管理及成本管理水平,打造新时期智慧矿山建设新标杆。 相似文献
57.
Obesity is a growing public health problem and the increased prevalence calls for preventive measures. Choice architecture and dual brain process thinking has been suggested as a promising strategy. One of the behaviors that are of significant public health nutrition concern is the intake of sugar sweetened beverages (SSB’s) of young people. An intervention was developed for 4 canteens for students (age 16–23) of vocational schools. We slightly re-arranged the location of SSB’s in drink coolers by reducing visibility. The canteen managers collected data on sales volumes of beverages in combination over a period of 3 weeks and the data collection was supplemented with interviews and observations. The results showed that the intervention was able to reduce the purchasing of SSB in three of the four canteens. In one of the canteens where the cooler was behind the cafeteria desk there were little difference. It is assumed to be due to the fact that the students could not see the cooler while standing in line. The results suggests that rethinking of the canteen interior and physical food environment has the potential to affect purchasing of SSB. 相似文献
58.
In this paper, a novel cooperative path planning scheme of unmanned surface vehicles (USVs) for rescuing targets in a complex ocean environment is proposed. The primary objective of the rescue USVs is to bring all targets back safely on the premise of first rescuing priority targets, while optimizing the path length, the navigation time and the angular energy. The main contributions of this paper are as follows: (1) The proposed K-means-division (KMD) algorithm is able to identify a complex ocean environment with collision-free zone and static-obstacles zone; (2) The proposed path planning method with fast-marching-method-based ellipse guidance range (E-FMM) is able to optimize the angular energy while ensuring safety; (3) The proposed cooperative management system (including priority-target-assignment (PTA) with reward-mechanism genetic-optimization (RM-GO) and collision-avoidance (CA) guidance law with Tangent-based surge-varying wave-disturbances-observer (Tangent-SV-WDO)) can accomplish the mission of the rescue USVs. Comparative studies with the state-of-the-art methods demonstrate that the proposed cooperative path planning scheme is superior in terms of priority-target-assignment (PTA) and collision-avoidance (CA) of the actual rescue work. 相似文献
59.
《International Journal of Hydrogen Energy》2022,47(3):2040-2049
The motion trajectory of hydrogen leakage is an essential safe issue for the application of hydrogen energy. A dimensionless fast-running motion trajectory prediction model is proposed to predict the dispersion characteristics of the buoyant jet of hydrogen leakage for the accident. The impact of different leakage angles, leakage velocity and thermal stratification of ambient air on hydrogen leakage behavior was analyzed. The new developed model was verified by experimental results in literatures. Leakage hydrogen can flow upwards freely in a uniform environment. However, it shows an oscillating trajectory at a certain height in a thermally stratified environment, which is so called “locking phenomenon”. The trajectory of hydrogen leakage is upward and hydrogen gathers at the top of the space to form stratification in a uniform environment, while the hydrogen leakage shows an oscillating trajectory at a certain height in a thermal stratification environment. With the increase of Froude number Fr, it shows that the stable height and maximum height of the leakage airflow have a trend of rising first and then falling in a thermally stratified environment. The findings are expected to give guidance in real-world situations, for example, a larger Fr value and a larger temperature gradient can lead to a decrease in the stable height in the thermally stratified environment. It is found that the fitting of the stable height with different temperature gradients satisfies the power function relationship. This work is expected to be helpful for reducing hydrogen leakage accumulation and explosion risk. 相似文献
60.
采用高通量测序技术结合数理统计软件分析方法,系统研究茅台镇酱香型白酒不同酿造轮次生产环境中的真菌菌群结构及特征。7 个轮次中共检测到4 个真菌门、212 个真菌属。根据各菌门、属的相对丰度,子囊菌门(Ascomycota)和担子菌门(Basidiomycota)是茅台镇酱香型白酒酿造环节中各酿造轮次的优势菌门,节担菌属(Wallemia)、复膜孢酵母属(Saccharomycopsis)为各轮次绝对优势真菌属。不同轮次环境样品中真菌组成结构的相似度较高,但其各轮次标志性真菌属存在差异。7 个酿造轮次共有相同真菌属56 个,在各轮次占主导地位,特征性真菌属在各轮次当中相对丰度和占比较小但种类丰富。Ascomycota最强节点为德巴利酵母属(Debaryomyces),Basidiomycota最强节点为红酵母属(Rhodotorula)。本研究揭示了茅台镇酱香型白酒不同酿造轮次环境中真菌菌群结构及其特征,为深入研究酱香型白酒酿造机理以及对酿造环境中微生物结构的解析提供了参考依据。 相似文献