Acute lesions of primary visual cortical areas in adult cats inactivate responses of neurons in higher visual cortices

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.

Visualization and Damage Assessment for Flooded Area

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.

Visual response characteristics of neurons in the second visual area of marmosets

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.

Visual processing of word and image in the fusiform gyrus

BACKGROUND： The role of the left midfusiform gyrus as a target for visual word processing has been a topic of discussion. Numerous studies have utilized alphabetic writing for subject matter. However, few have addressed visual processing of Chinese characters in the left midfusiform gyrus. OBJECTIVE： To verify visual processing of Chinese characters and images in the left midfusiform gyrus using functional magnetic resonance imaging. DESIGN, TIME AND SETTING： A blocked design paradigm study. Experiments were performed at the Room of Magnetic Resonance, Guangdong Provincial Second People＇s Hospital, China from May to June 2009. PARTICIPANTS： A total of eight undergraduate students were recruited from Guangzhou University of China, comprising two females and six males, aged 20-23 years. The subjects were right-handed which was determined by a Chinese standard questionnaire. None of the subjects had a history of psychoneurosis, familial disease, color blindness, or color weakness. METHODS： A total of eight undergraduates were enrolled as subjects. Picture-naming and verb generation tasks were employed through the use of functional magnetic resonance imaging. Analysis of Functional Neurolmages software was used to process the data. MAIN OUTCOME MEASURES： Visual processing of Chinese characters and images in the left midfusiform gyrus was measured. RESULTS： Picture-naming and verb generation tasks were shown to significantly activate the bilateral midfusiform gyrus. Activation occurred in the visual word form area of the left midfusiform gyrus. CONCLUSION： The left midfusiform gyrus plays a general role in visual processing of Chinese characters and images.

Detecting visually salient scene areas and deriving their relative spatial relations from continuous street-view panoramas

A salient scene is an area within an image that contains visual elements that stand out from surrounding areas.They are important for distinguishing landmarks in first-person-view(FPV)applications and determining spatial relations in images.The relative spatial relation between salient scenes acts as a visual guide that is easily accepted and understood by users in FPV applications.However,current digitally navigable maps and location-based services fall short of providing information on visual spatial relations for users.This shortcoming has a critical influence on the popularity and innovation of FPV applications.This paper addresses the issue by proposing a method for detecting visually salient scene areas(SSAs)and deriving their relative spatial relationships from continuous panoramas.This method includes three critical steps.First,an SSA detection approach is introduced by fusing region-based saliency derived from super-pixel segmentation and the frequency-tuned saliency model.The method focuses on a segmented landmark area in a panorama.Secondly,a street-view-oriented SSA generation method is introduced by matching and merging the visual SSAs from continuous panoramas.Thirdly,a continuous geotagged panorama-based referencing approach is introduced to derive the relative spatial relationships of SSAs from continuous panoramas.This information includes the relative azimuth,elevation angle,and the relative distance.Experiment results show that the error for the SSA relative azimuth angle is approximately±6°(with an average error of 2.67°),and the SSA relative elevation angle is approximately±4°(with an average error of 1.32°)when using Baidu street-view panoramas.These results demonstrate the feasibility of the proposed approach.The method proposed in this study can facilitate the development of FPV applications such as augmented reality(AR)and pedestrian navigation using proper spatial relation.

传统数据中心网络向AD-DC平滑演进技术分析

本文阐述了传统数据中心网络如何向AD-DC平滑演进的三种场景,每种场景对应的迁移方案,以及通过一个示例描述整个迁移过程。随着云计算、大数据、移动互联网的兴起,数据中心流量与日俱增,业务上线节奏加快,要求数据中心网络做出快速响应,传统数据中心网络向AD-DC演进将是必然趋势,AD-DC解决方案满足数字化转型中不断扩张的网络需求,不断迭代创新为客户提供智能融合、安全可靠、先进成熟、开放包容的全栈数据中心网络解决方案,助力更多行业客户的数字化转型实践。