Temporal integration in Pavlovian appetitive conditioning in rats

We used an appetitive sensory preconditioning procedure to investigate temporal integration in rats in two experiments. In Phase 1, rats were presented with simultaneous compound trials on which a 10-sec conditioned stimulus (CS) X was embedded within a 60-sec CS A. In Group Early, CS X occurred during the early portion of CS A, whereas in Group Late, CS X occurred during the latter portion of CS A. In Phase 2, CS X was paired simultaneously with sucrose. On a subsequent test with CS A, the rate of magazine entries peaked during the early portions of the stimulus in Group Early and during the latter portions of the stimulus in Group Late (Experiments 1 and 2). Similar response peaks were not observed on tests with a control stimulus that had been presented in compound with a stimulus that did not signal reward (Experiment 2).     

Spatial learning by rats across visually disconnected environments

Experiments were designed in which some properties of spatial representations in rats could be examined. Adult subjects were trained to escape through a hole at a fixed position in a large circular arena (see Schenk, 1989). The experiments were conducted in the dark, with a limited number of controlled visual light cues, in order to assess the minimal cue requirement for place learning. Three light cues identical in shape, height, and distance from the table were used. Depending on the condition, they were either permanently on or alternatively on or off, contingent on the position of the rat in the field. Two questions were asked: (1) How many identical visual cues were necessary for spatial discrimination in the dark, and (2) could rats integrate the relative positions of separate cues, under conditions in which the rat was never allowed to perceive all three cues simultaneously. The results suggest that rats are able to achieve a place discrimination task even if the three cues necessary for efficient orientation can never be seen simultaneously. A dissociation between the discrimination of the spatial position of the goal and the capacity to reach it by a direct path suggests that, with a reduced number of cues, prolonged locomotion might be required for accurate orientation in the environment.     

Spatial memory in rats: Resistance to retroactive interference

Treatments that interfere with animals’ short-term retention (e.g., in delayed matching-to-sample) were studied using a spatial memory task. Rats performed in an eight-arm radial maze in which choosing each arm without repetition was the optimal behavior. Performances were interrupted between fourth and fifth choices for a delay of 15 sec to 2 min. A variety of events occurring during the delay interval did not disrupt memories for prior choices (as assessed by the accuracy of postdelay choices). The ineffective treatments included variations in visual and auditory environments, removal from the maze, food consumed during the delay, a distinctive odor added to the maze, or combinations of these manipulations. Additionally, performance on another spatial task (a four-arm maze) during the delay between Choices 4 and 5 did not interfere with performance in the eight-arm maze. These findings suggest that rats’ memories for spatial locations are immune to retroactive interference, at least within the range of conditions reported, and that the rat can successfully segregate memories for spatial locations established in different contexts.     

Spatial pattern learning in rats: Conditional control by two patterns

Rats searched for food hidden on top of poles in a 4 × 4 matrix of poles. Before each trial, the location of the four baited poles was unpredictable. However, the poles were always baited in one of two spatial patterns, either a square or a line. The food hidden on the four baited poles was one of two types, and the food type determined the identity of the pattern. Thus, once one baited pole was discovered, the food type provided a cue for the spatial pattern in which the remaining food was hidden. The results showed that rats learned the two spatial patterns in which the food was hidden and used the conditional cue to determine which pattern was relevant on individual trials, thereby increasing the efficiency of spatial search.     

Spatial memory and the performance of rats and pigeons in the radial-arm maze

The resource-distribution hypothesis states that the ability of an animal to remember the spatial location of past events is related to the typical distribution of food resources for the species. It appears to predict that Norway rats would perform better than domestic pigeons in tasks requiring spatial event memory. Pigeons, tested in an eight-arm radial maze, exhibited no more than half of the memory capacity observed in rats in the same apparatus and may not have used spatial memory at all. The results were interpreted as supporting the hypothesis.     

新媒体与红色文化关系整合研究

任何文化都离不开传播。没有传播,文化的传承就是不现实的事情。传播的内容不能离开文化,离开文化的传播,就失去了精髓,没有了内涵,势必变得肤浅、表面和世俗。因此,将这两方面共同研究,研究整合过程是具有相当理论价值和现实意义的。     

一类含三角函数定积分的一个注记

含三角函数的积分是应用中极为常见的一类积分,在实际计算时,如果三角函数次数较高,需多次应用递推公式以得到最后结果,过程复杂繁琐.本文总结了一类含三角函数定积分的相关性质,同时给出了有别于递推公式的一般公式,能极大的简化含高次三角函数积分的计算。     

The integration of pupils with learning difficulties: the results of research into the effects of integration

ABSTRACT

The authors present the outcomes of an empirical study, effected in integrative and segregative models of schooling in German speaking Switzerland. The following questions have been analysed: a) the changes in performances of pupils with learning difficulties under different conditions of schooling; b) the development of social factors; c) the development of emotional characteristics. With regard to academic achievements, integrative measures proved to be more effective than instruction in self‐contained special classes. The findings concerning the development of social and emotional characteristics do not allow to draw clear conclusions either in favour of or against integration. Still, the outcomes of this study encourage to carry on experiments with integrative forms of schooling.     

Riemann integration

Riemann had revolutionized the fields of analysis, geometry and mathematical physics. His ideas concerning geometry of space had a profound effect on the development of modern theoretical physics. Riemannian manifolds, Riemann surfaces, the Cauchy—Riemann equations, the Riemann hypothesis-all these and more are packed into his one-volume collected works. Riemann clarified the notion of integration by defining, a little over 135 years ago, what we now call theRiemann integral. This article is devoted to a study of the Riemann integral.     

Effect of preschool integration for children with disabilities.

This study examined the effects of integration and segregation in a special education preschool program for children with mild to moderate disabilities to determine whether initial level of development differentially influenced gains achieved. No main-effect differences between the two groups appeared on several pretest and posttest measures. Aptitude-by-Treatment analyses revealed than higher performing students gained more from integrated classes, whereas lower performing students gained more from segregated classes. The data suggest careful monitoring of lower functioning students to ensure appropriate academic and social stimulation.     

Effects of social integration on preschool children with handicaps

This study examined the effects of (a) integrating handicapped and nonhandicapped children in preschools and (b) a condition designed to promote social integration. Fifty-six children with mild and moderate handicaps were randomly assigned to four experimental conditions: integrated/social interaction, integrated/child-directed, segregated/social interaction, and segregated/child-directed. Observation revealed a higher proportion of interactive play, as well as higher language development, in the social interaction conditions; and children in the integrated/social interaction condition received significantly higher ratings of social competence. These data suggest that structuring social interaction between higher and lower performing children can result in benefits to the lower performing students.     

空间直线的单相机测量

提供一种单相机测量空间直线的方法.通过五组相互垂直直线成像实现相机标定,对空间直线成像;通过求解直线在图像上的消隐点,求解空间直线在相机坐标系下的方向.实物计算表明,该测量方案是正确可行的.     

定积分计算中一个结论的推广

在定积分计算中,常常可以利用一个结论来简化计算偶函数、奇函数在对称于原点的区间上的定积分,这个结论能否在重积分计算中使用?本文给出该结论的推广使用方法。     

Spatial matching and nonmatching in male and female Wistar rats: Effects of delay-interval duration

Male and female Wistar rats were trained in a delayed matching-to-position procedure in which one of the two levers (sample) was presented. Pressing this lever resulted in its retraction and began a delay interval of random variable duration, which terminated with the occurrence of the first nose poke in the pellet retrieval unit after the delay interval had expired. Both levers were then inserted into the chamber, and food became available when the subject pressed the lever that had previously been pressed (matching response). When the subject failed to make a matching response, time out (5 sec) was presented. In the next experimental condition, nonmatching was reinforced. Males and females required an equal number of trials to attain 80% accuracy during three consecutive sessions under matching and nonmatching conditions. Response accuracy decreased as the delay interval increased, during both conditions. Differences between the sexes were not observed, suggesting that memory functions in male and female rats may only differ when other behavioral differences between the sexes are allowed to interfere with the assessment of memory functioning.     

跨学科综合性实验平台的探索与设计

针对现有控制、电气以及建工类实验课程偏重于各自学科的基础性和验证性实验,较少开展具有知识探索与创新发现为特点的跨学科综合性实验的现状,通过将各个学科有限的实验教学资源进行整合优化,探索和设计具有跨学科、层次化的综合性实验平台,最大限度共享和调度学科之间的软硬件实验资源,引导学生综合应用学科交叉基础知识和实验技能,并将科研实践的开展和管理方式移植到综合性实验项目的设计和实施上,促进创新型宽口径人才的培养和推进实验教学改革。     

Supporting learning with interactive multimedia through active integration of representations

When learners explore dynamic and interactive visualisations they are often not able to interact with them in a systematic and goal-oriented way. Frequently, even supporting learners in processes of discovery learning does not lead to better learning outcomes. This can be due to missing pre-requisite knowledge such as the coherent mental integration of the pictorial and symbolic sources of information. In order to support learners in this process, we encouraged them to interactively and externally relate different static sources of information to each other before exploring dynamic and interactive visualisations. We evaluated the benefit of this instructional support in two experimental studies concerning the domains of statistics and mechanics. It revealed that the active integration of static representations before processing dynamic visualisations resulted in better performance and can provide a basis for a more systematic and goal-oriented experimentation behaviour during simulation-based discovery learning.in final form: 16 November 2004     

融合研究性教学的汽车虚拟仿真教学平台

分析了汽车虚拟仿真教学平台的研究现状和建设融合研究性教学的汽车虚拟仿真教学平台的必要性。为在学生—教师—学校—社会广义教育生态系统的各个环节协同促进学生的研究性学习,提出了融合研究性教学的汽车虚拟仿真教学平台的建设目标以及教学体系、方法和内容。教学改革实践证明:融合研究性教学的汽车虚拟仿真教学平台具有发展的可持续性,有利于培养具有较强创新能力和工程应用能力的汽车专业人才。