不同户外环境景观对幼儿角色扮演游戏的承载性分析

幼儿园户外环境景观是影响儿童户外游戏的重要因素,适宜儿童发展的户外环境景观应将自然、游戏和儿童发展有效结合,以促进儿童身心全面协调发展。本研究以某幼儿园18名5~6岁幼儿为研究对象,通过斯米兰斯基量表和游戏检核表,对幼儿在自然园林景观游戏场地和人工游戏场地中发生的角色扮演游戏进行观察评价,以此分析不同户外环境景观对幼儿角色扮演游戏的承载性,结果表明相比于人工游戏场地,自然园林景观游戏场地更易诱发幼儿的角色扮演游戏;幼儿在自然园林景观游戏场地中的角色扮演游戏类型更丰富,游戏水平也更高。幼儿园应走出把角色扮演游戏定位为室内游戏的局限,尽最大努力从空间布局、行为设施、游戏道具等方面设计和创建具有自然气息的户外环境,从而最大限度地支持儿童自发、自主的户外角色扮演游戏,同时让儿童在户外自然园林景观中得到类似大自然的熏陶。

Fast wireless sensor for anomaly detection based on data stream in an edge-computing-enabled smart greenhouse

Edge-computing-enabled smart greenhouses are a representative application of the Internet of Things(IoT)technology,which can monitor the environmental information in real-time and employ the information to contribute to intelligent decision-making.In the process,anomaly detection for wireless sensor data plays an important role.However,the traditional anomaly detection algorithms originally designed for anomaly detection in static data do not properly consider the inherent characteristics of the data stream produced by wireless sensors such as infiniteness,correlations,and concept drift,which may pose a considerable challenge to anomaly detection based on data stream and lead to low detection accuracy and efficiency.First,the data stream is usually generated quickly,which means that the data stream is infinite and enormous.Hence,any traditional off-line anomaly detection algorithm that attempts to store the whole dataset or to scan the dataset multiple times for anomaly detection will run out of memory space.Second,there exist correlations among different data streams,and traditional algorithms hardly consider these correlations.Third,the underlying data generation process or distribution may change over time.Thus,traditional anomaly detection algorithms with no model update will lose their effects.Considering these issues,a novel method(called DLSHiForest)based on Locality-Sensitive Hashing and the time window technique is proposed to solve these problems while achieving accurate and efficient detection.Comprehensive experiments are executed using a real-world agricultural greenhouse dataset to demonstrate the feasibility of our approach.Experimental results show that our proposal is practical for addressing the challenges of traditional anomaly detection while ensuring accuracy and efficiency.

High-Performance Magnetic-core Coils for Targeted Rodent Brain Stimulations

Objective and Impact Statement.There is a need to develop rodent coils capable of targeted brain stimulation for treating neuropsychiatric disorders and understanding brain mechanisms.We describe a novel rodent coil design to improve the focality for targeted stimulations in small rodent brains.Introduction.Transcranial magnetic stimulation(TMS)is becoming increasingly important for treating neuropsychiatric disorders and understanding brain mechanisms.Preclinical studies permit invasive manipulations and are essential for the mechanistic understanding of TMS effects and explorations of therapeutic outcomes in disease models.However,existing TMS tools lack focality for targeted stimulations.Notably,there has been limited fundamental research on developing coils capable of focal stimulation at deep brain regions on small animals like rodents.Methods.In this study,ferromagnetic cores are added to a novel angle-tuned coil design to enhance the coil performance regarding penetration depth and focality.Numerical simulations and experimental electric field measurements were conducted to optimize the coil design.Results.The proposed coil system demonstrated a significantly smaller stimulation spot size and enhanced electric field decay rate in comparison to existing coils.Adding the ferromagnetic core reduces the energy requirements up to 60%for rodent brain stimulation.The simulated results are validated with experimental measurements and demonstration of suprathreshold rodent limb excitation through targeted motor cortex activation.Conclusion.The newly developed coils are suitable tools for focal stimulations of the rodent brain due to their smaller stimulation spot size and improved electric field decay rate.

Discovery of novel ursolic acid derivatives as effective antimicrobial agents through a ROS-mediated apoptosis mechanism

In response to the reduction of food production and economic losses caused by plant bacterial diseases, it is necessary to develop new, efficient, and green pesticides. Natural products are rich and sustainable source for the development of new pesticides due to their low toxicity, easy degradation, and eco-friendliness. In this study, we prepared three series of ursolic acid derivatives and assessed their antibacterial ability. Most target compounds exhibited outstanding antibacterial activities. Among them, the relative optimal EC50 values of Xanthomonas oryzae pv. oryzae and Xanthomonas axonopodis pv. citri were 2.23 (A17) and 1.39 (A16) μg·mL^(-1), respectively. The antimicrobial mechanism showed that compound A17 induced an excessive accumulation and production of reactive oxygen species in bacteria and damaged the cell membrane integrity to kill bacteria. More interestingly, the addition of low concentrations of exogenous hydrogen peroxide enhanced the antibacterial efficacy of compound A17 against Xanthomonas oryzae pv. oryzae. These entertaining results suggested that compound A17 induced an apparent apoptotic behavior in the tested bacteria. Overall, we developed the promising antimicrobial agents that destroyed the redox system of phytopathogenic bacteria, further demonstrating the unprecedented potential of ursolic acid for agricultural applications.