The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics ...The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics of V2 neurons in four healthy adult marmosets using intracortical tungsten microelectrodes. We recorded 110 neurons in area V2, with receptive fields located between 8° and 15° eccentricity. Most(88.2%) of these neurons were orientation selective, with half-bandwidths typically ranging between 10° and 30°. A significant proportion of neurons(28.2%) with direction selectivity had a direction index greater than 0.5. The vast majority of V2 neurons had separable spatial frequency and temporal frequency curves and, according to this criterion, they were not speed selective. The basic functional response characteristics of neurons in area V2 resemble those found in area V1. Our findings show that area V2 together with V1 are important in primate visual processing, especially in locating objects in space and in detecting an object's direction of motion. The methods used in this study were approved by the Monash University Animal Ethics Committee, Australia(MARP 2009-2011) in 2009.展开更多
It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this s...It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this study, we used visual language stimulation to examine visual-auditory functional connectivity. For this, we used functional magnetic resonance imaging (fMRI) in a congenitally deaf subject to localize areas in the auditory cortex that showed cross-modal reorganization for the processing of visual language inputs and estimate areas in the visual ventral stream, from which language signal inputs enter the auditory areas in the congenitally deaf. We found that the anterior region of the secondary auditory cortex in the superior temporal gyrus showed language-specific activation and that the visual inputs into the area were from the fusiform gyrus, which is a high-level visual area.展开更多
Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, how...Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.展开更多
A practical method for visualizing flood area and evaluating damage is presented,which consists of two technical approaches:self-programming and adapting commercial GIS platforms.The low-cost and easy-to-use GIS-Based...A practical method for visualizing flood area and evaluating damage is presented,which consists of two technical approaches:self-programming and adapting commercial GIS platforms.The low-cost and easy-to-use GIS-Based model developed by self-programming can meet current requirements of most local authorities,especially in developing countries.In this model,two cases,non-source flood and source flood,are distinguished and the Seed-spread algorithm suitable for source-flood is discussed;The flood damage is assessed by overlaying the flood area range with thematic maps and other related social and economic data.and all thematic maps are converted to raster format before overlay analysis.Two measures are taken to improve the operation efficiency of speed seed-spread algorithm.The accuracy of the model mainly depends on the resolution and precision of the DEM data,and the accuracy of registering all raster layers and the quality of attribute data.展开更多
为揭示国内外数字农业研究发展脉络及未来趋势,基于2002—2024年中国知网(CNKI)数据库和Web of Science(WOS)数据库中数字农业领域的6293篇高质量文献,采用文献计量分析法,运用CiteSpace 6.2.R6软件进行可视化计量分析。结果表明:1)全...为揭示国内外数字农业研究发展脉络及未来趋势,基于2002—2024年中国知网(CNKI)数据库和Web of Science(WOS)数据库中数字农业领域的6293篇高质量文献,采用文献计量分析法,运用CiteSpace 6.2.R6软件进行可视化计量分析。结果表明:1)全球学科交叉呈现技术生态强耦合与人文制度弱参与的失衡态势,农学与信息科学深度融合构成技术主轴,但社会科学贡献显著不足,硬件研发主导模式进一步制约算法创新进程。2)国内外融合路径形成显著梯级分化,国外研究较早实现感知—决策—执行的闭环技术整合,而国内长期处于硬件技术嫁接阶段,算法与农艺机理的深层协同存在明显迟滞。3)驱动力机制呈现根本差异,国内政策导向型研究形成农学和经济学深度融合特征,高频关键词集中反映国家战略牵引;国际则凸显市场驱动的技术创新路径,但双方均未培育出适配小规模经营的交叉研究集群。4)系统性发展缺口集中显现于三大维度,微观农艺过程与智能决策模型的理论割裂、小农户数字包容的制度缺位以及气候智慧农业与碳计量技术的协同空白。未来研究应深化理论与实践的融合探索,通过加强国际合作与知识共享,创新数字技术驱动农业转型模式,构建多维协同的差异化发展路径,系统整合数字农业的多元复合价值,全面助力中国农业农村现代化高质量发展。展开更多
“十四五”时期,我国即将迈入中度老龄化阶段,老旧小区适老化设计已成为相关研究热点。基于CiteSpace软件,对2000—2023年间中国知网(CNKI)与Web of Science(WoS)数据库中收录的老旧小区适老化设计相关文献进行可视化分析,梳理并对比国...“十四五”时期,我国即将迈入中度老龄化阶段,老旧小区适老化设计已成为相关研究热点。基于CiteSpace软件,对2000—2023年间中国知网(CNKI)与Web of Science(WoS)数据库中收录的老旧小区适老化设计相关文献进行可视化分析,梳理并对比国内外该领域的研究热点与发展趋势。借鉴国际实践经验,可为我国该领域研究方向提供参考,以促进老龄化社会背景下人居环境的和谐发展。展开更多
基金supported by travel grants from Monash University and the University of Sichuan(to YY)Research Grants from the Australian Research Council(No.DP0451206)(to MGPR)National Health and Medical Research Council(No.384115)(to MGPR)。
文摘The physiological characteristics of the marmoset second visual area(V2) are poorly understood compared with those of the primary visual area(V1). In this study, we observed the physiological response characteristics of V2 neurons in four healthy adult marmosets using intracortical tungsten microelectrodes. We recorded 110 neurons in area V2, with receptive fields located between 8° and 15° eccentricity. Most(88.2%) of these neurons were orientation selective, with half-bandwidths typically ranging between 10° and 30°. A significant proportion of neurons(28.2%) with direction selectivity had a direction index greater than 0.5. The vast majority of V2 neurons had separable spatial frequency and temporal frequency curves and, according to this criterion, they were not speed selective. The basic functional response characteristics of neurons in area V2 resemble those found in area V1. Our findings show that area V2 together with V1 are important in primate visual processing, especially in locating objects in space and in detecting an object's direction of motion. The methods used in this study were approved by the Monash University Animal Ethics Committee, Australia(MARP 2009-2011) in 2009.
文摘It is well known that auditory cortical areas are activated by visual stimulation in the deaf. However, it is not known whether the information enters from the primary visual area or high-level visual areas. In this study, we used visual language stimulation to examine visual-auditory functional connectivity. For this, we used functional magnetic resonance imaging (fMRI) in a congenitally deaf subject to localize areas in the auditory cortex that showed cross-modal reorganization for the processing of visual language inputs and estimate areas in the visual ventral stream, from which language signal inputs enter the auditory areas in the congenitally deaf. We found that the anterior region of the secondary auditory cortex in the superior temporal gyrus showed language-specific activation and that the visual inputs into the area were from the fusiform gyrus, which is a high-level visual area.
基金National Natural Science Foundation of China (31171082)Natural Science Foundation of Anhui Province (070413138)Key Research Foundation of Anhui Province Education Department (KJ2009A167)
文摘Psychophysical studies suggest that lateral extrastriate visual cortical areas in cats may mediate the sparing of vision largely by network reorganization following lesions of early visual cortical areas. To date, however, there is little direct physiological evidence to support this hypothesis. Using in vivo single-anit recording techniques, we examined the response of neurons in areas 19, 21, and 20 to different types of visual stimulation in cats with or without acute bilateral lesions in areas 17 and 18. Our results showed that, relative to the controls, acute lesions inactivated the response of 99.3% of neurons to moving gratings and 93% of neurons to flickering square stimuli＇in areas 19, 21, and 20. These results indicated that acute lesions of primary visual areas in adult eats may impair most visual abilities. Sparing of vision in cats with neonatal lesions in early visual cortical areas may result largely from a postoperative reorganization of visual pathways from subcortical nucleus to extrastriate visual cortical areas.
文摘A practical method for visualizing flood area and evaluating damage is presented,which consists of two technical approaches:self-programming and adapting commercial GIS platforms.The low-cost and easy-to-use GIS-Based model developed by self-programming can meet current requirements of most local authorities,especially in developing countries.In this model,two cases,non-source flood and source flood,are distinguished and the Seed-spread algorithm suitable for source-flood is discussed;The flood damage is assessed by overlaying the flood area range with thematic maps and other related social and economic data.and all thematic maps are converted to raster format before overlay analysis.Two measures are taken to improve the operation efficiency of speed seed-spread algorithm.The accuracy of the model mainly depends on the resolution and precision of the DEM data,and the accuracy of registering all raster layers and the quality of attribute data.
文摘为揭示国内外数字农业研究发展脉络及未来趋势,基于2002—2024年中国知网(CNKI)数据库和Web of Science(WOS)数据库中数字农业领域的6293篇高质量文献,采用文献计量分析法,运用CiteSpace 6.2.R6软件进行可视化计量分析。结果表明:1)全球学科交叉呈现技术生态强耦合与人文制度弱参与的失衡态势,农学与信息科学深度融合构成技术主轴,但社会科学贡献显著不足,硬件研发主导模式进一步制约算法创新进程。2)国内外融合路径形成显著梯级分化,国外研究较早实现感知—决策—执行的闭环技术整合,而国内长期处于硬件技术嫁接阶段,算法与农艺机理的深层协同存在明显迟滞。3)驱动力机制呈现根本差异,国内政策导向型研究形成农学和经济学深度融合特征,高频关键词集中反映国家战略牵引;国际则凸显市场驱动的技术创新路径,但双方均未培育出适配小规模经营的交叉研究集群。4)系统性发展缺口集中显现于三大维度,微观农艺过程与智能决策模型的理论割裂、小农户数字包容的制度缺位以及气候智慧农业与碳计量技术的协同空白。未来研究应深化理论与实践的融合探索,通过加强国际合作与知识共享,创新数字技术驱动农业转型模式,构建多维协同的差异化发展路径,系统整合数字农业的多元复合价值,全面助力中国农业农村现代化高质量发展。
文摘“十四五”时期,我国即将迈入中度老龄化阶段,老旧小区适老化设计已成为相关研究热点。基于CiteSpace软件,对2000—2023年间中国知网(CNKI)与Web of Science(WoS)数据库中收录的老旧小区适老化设计相关文献进行可视化分析,梳理并对比国内外该领域的研究热点与发展趋势。借鉴国际实践经验,可为我国该领域研究方向提供参考,以促进老龄化社会背景下人居环境的和谐发展。
