A matching law analysis of the reinforcing efficacy of wheel running in rats

Previous research has demonstrated that running in a rotating wheel functions as a reinforcer for leverpressing in rats. In these studies, the pattern of responding was similar to the pattern of responding maintained by consummatory reinforcers, such as food and water. The present study investigated quantitative features of responding maintained by running. In previous experiments in which responses were reinforced according to variable-interval (VI) schedules and food and water served as the reinforcer, the equation for a rectangular hyperbola described the relationship between response rate and reinforcement rate. This experiment tested whether this quantitative regularity also applies to leverpressing maintained by the opportunity to run in a wheel. Fourteen male Wistar rats responded on levers for the opportunity to run. In each session, subjects were exposed to a series of VI schedules. An opportunity to run for 60 sec was the reinforcing consequence. Results showed that response rate was a negatively accelerated function of reinforcement rate, and the relationship between these two variables was described well by the equation for a rectangular hyperbola. To further test the similarity between running and consummatory reinforcers, the response requirement and access were manipulated. In previous experiments with food and water, these types of manipulations differentially changed the two parameters of the hyperbola. A similar pattern of results was obtained with wheel running. Thus, the equation appears to apply to running about as well as it does to consummatory reinforcers.     

Frequency,duration, and speed of wheel running of rats as a function of age and starvation

The purpose of this experiment was to determine whether age differences in amounts of wheel running of starved rats were due to the frequency of bursts of running, to the average duration of bursts, to speed, or to any combination of these parameters. The experiment was carried out according to a 3 by 2 by 2 mixed model design. The independent variables were age (67, 293, and 746 days old at the start of starvation), food deprivation (total starvation vs ad lib), and occasion of measurement (initial vs maximum activity). The dependent variables were number of wheel revolutions, number of bursts of activity, number of seconds of running per burst, and revolutions per second. The results indicated that acutely starved rats run more often, for longer periods, and at higher speeds than do sated rats, and that with increased age rats run less often, for a shorter time, and at slower speeds.     

机动车方向盘右置右行方案对安全的影响

以驾驶员视野分布理论为基础,通过对交通事故原因的分析,提出了方向盘右置机动车右行的方案。在统计数据的基础上,将新方案与传统的左置右行方案对可能产生的事故结果进行了对比,认为方向盘右置右行方案相对于左置右行方案,可降低机动车与非机动车之间的交通事故,减少伤亡人数。     

The effects of variations in the interpellet interval on wheel running in the rat

Three rats were given access to a running wheel during spaced food deliveries. As the interpellet interval increased, the overall amount of running increased, the rate of running neither systematically increased nor decreased, and the locus of maximal running occurred later in the interpellet interval. Both the overall amount and the temporal distribution of running exhibited considerable within-schedule changes during successive exposures to the different schedules. These data are discussed in terms of Staddon’s (1977) assignment of behavior into different functional classes, that is, schedule-induced and facultative.     

The development of self-reinforcing running in satiated rats

Fast, “playful” running was obtained in rats never given reward for running in an alley. The maintenance of such running was not dependent on hunger, thirst, or an “exercise” drive produced by confinement in small home cages. However, hunger facilitated the development of “playful” nonrewarded running in rats which initially did not run when food-satiated. “Playful” running was not seen in hungry, rewarded rats or in hungry, nonrewarded rats fed immediately after their daily running sessions. Probably incentive, but not drive, prevents the occurrence of self-reinforcing running.     

Temporal patterns of schedule-induced drinking and pawgrooming in rats exposed to periodic food

Five rats were exposed to fixed-time food schedules, ranging from 30 to 480 sec. Three rats displayed a postfood pattern of schedule-induced drinking, with short latencies from food delivery to drinking at all interfood interval durations. In contrast, drinking for the other 2 subjects tended to occur at lower overall levels, and drinking bouts frequently began in the middle of the interfood interval, such that the latency from food delivery to drinking increased dramatically as the interfood interval increased. Observation of these 2 subjects revealed that another form of licking-pawgrooming-occurred reliably after food delivery and before drinking bouts. A between subject comparison of the 3 postfood drinkers and the 2 pawgroomers revealed that, in addition to a common topography (repetitive licking), pawgrooming and drinking were similar with respect to their temporal locus, relation to the interfood interval, and extinction baseline levels. These similarities suggest that drinking and pawgrooming are induced by a common mechanism. Cohen, Looney, Campagnoni, and Lawler’s (1985) two-state model of reinforcer-induced motivation provides a useful framework for the interpretation of these results.     

The origin and functions of adjunctive behavior

The major determinants of schedule-induced or adjunctive behavior are reviewed briefly. Adjunctive behavior and its ethological equivalent, displacement activity, has a stabilizing function on agonistic, mating, parental, and intermittent-feeding behavior when any of these activities are in unstable equilibrium with an escape vector. This buffering action of adjunctive behavior is analogous to the diversity-stability rule of ecology in which an increase in the diversity of species stabilizes the populations of the component species, thereby preventing extinction. Opposing behavioral vectors in unstable equilibrium can function to exaggerate certain behavioral adjuncts that preexist in a situation. The resulting increase in diversification (information) augments the overall stability of the opposing-vector circumstance, conserving the context. This strengthening process is discussed in relation to ritualization and the preadaptation of exaggerated behavior to new functions.     

Chronic morphine drinking establishes morphine tolerance, but not addiction in Wistar rats

Objective： Some animal models apply morphine in the drinking water to generate addiction, but related reports are not free of conflicting results. Accordingly, this study aimed to figure out if chronic consumption of morphine in the drinking water can induce morphine addiction in Wistar rats. Methods： For 3 weeks, the animals received a daily morphine dose of 35 mg/kg by offering a calculated volume of sugar water （5% sucrose） with morphine （0. l mg/ml） to each rat; animals receiving just sugar water served as controls. Immediately after the treatment phase, the tail immersion test was used to check for morphine tolerance, and all animals were then kept on tap water for one week （withdrawal phase）. Afterwards, all rats were allowed to choose their drinking source by offering two bottles, containing sugar water without and with morphine, simultaneously for two days （preference phase）. Results： While the chronic consumption of morphine led to a reduction in body weight and to morphine tolerance, the morphine-treated Wistar rats did not show any preference for the opiate-containing sugar water. Conclusion： Body weight loss and tolerance do not reveal a condition of drug craving, and current animal models should be re-evaluated regarding their potential to establish morphine addicted animals.     

独立学院的办学定位与办学主体转换——依托名校办分校的“办学主体转换机制”研究

实现独立学院办学主体转换的途径是独立学院确立自己的办学定位,并且建设与这种定位相适应的师资队伍和人才培养体系。独立学院现阶段的办学定位是办好大众化高等教育,为社会培养和输送应用型人才。师资队伍建设的重点是增强教师的实践素养,培养和引进骨干教师组建教学团队。探索建构"大众化、应用型"人才培养体系,要认真研究和借鉴工程教育的教育理念和教育模式。     

齿轮图(w～n)和l(w～n)的k-优美性

我们知道轮Wn及齿轮图wn都是优美图．马克杰等在文[1]中已证明了轮wn和齿轮wn都是优美图．本文将证明wn是k-优美图，并证明了当，n=0(mod2)时lwn也是七一优美图．     

Modulation of taste-induced drinking: The effects of concentration shifts and drinking interruptions

The drinking of saccharin solutions by nondeprived rats was found to increase on initial exposure as a function of daily sessions and not as a function of previous state of deprivation or vigor of drinking. Large and persisting positive and negative successive contrast effects followed a single shift in concentration. Forcing the drinking to occur in short bouts by withdrawing the drinking tube elevated total intake above the level established by the positive and negative contrasts. The drinking returned to baseline when uninterrupted drinking was permitted. Maximum drinking occurred with 10- and 20-min interruptions of 2-min drinking periods. Consecutive daily interrupted drinking sessions did not produce further increases in drinking, as might have been predicted by opponent process theory or by a classical conditioning interpretation. It was suggested that the persistence of the positive and negative contrasts was dependent on the limited past experience of the animals with the saccharin taste, and that the enhancement of drinking by interruption may depend on the increased excitement produced by drinking tube withdrawal and the reduction of the excitement by reintroduction of the tube.     

图像处理与识别在车轮踏面故障检测中的应用

图像识别在故障诊断中有重要作用.车轮踏面缺陷主要有剥离、裂纹2种形式.介绍了车轮踏面故障测试系统的原理及程序总体框图,它采用图像处理方法作为获取故障特征的手段,将聚类识别和判别分析的概念有机结合,实现了对故障的准确定位,为故障的及时维修提供了强有力的支持.     

闽台高校合作办学的现状与展望

闽台合作办学具有良好的历史基础与现实条件,已经形成良好的发展势头,在合作规模、合作形式、专业建设及联合人才培养等方面取得了显著的成绩。海西建设及闽台交流的深入发展虽然为高校合作办学注入了动力,但是其后续发展依然面临诸如合作的形式、水平、层次、经费及政策等方面的限制。因此,要深化闽台高校合作办学需要立足现实、统筹内外部资源,切实深化办学层次,拓展办学领域,提升办学水平,推进制度建设,着力构建合作办学机构的现代大学制度。     

实验中心开放运行模式的探索和实践

该文介绍了西安电子科技大学国家级电工电子实验教学示范中心开放运行模式,阐述了开放模式的具体内容和网络信息化管理平台的建设。     

吉尔曼大学思想述评

吉尔曼是美国第一所真正意义的研究型大学——约翰·霍普金斯大学的创建者。他认为,大学是为年轻人提供高层次教育和追求高深学问的场所;大学的使命在于增进真理与传播知识;大学的功能在于教育、研究与服务社会;大学是一个自由的所在,其学术自由不容侵犯;大学与社会是动态且良性互补的系统,需要与社会保持有距离的互动。     

发现了目标,也找到了方法万科快跑2006!

调控年提前预防 2006年3月21日,万科企业股份有限公司(以下简称万科)公布了2005年报,数据显示,全年实现销售收入139.5亿元,同比增长52.3%,实现营业收入105.6亿元,同比增长37.7%,净利润达13.5亿元,同比增长53.8%,公司净资产收益率达至 16.3%.     

创新教育体系的开发与运转

以大学本科四年为整体，系统构思和开发了创新教育体系的基本框架，为创新教育的实施提供了较大的时间和空间自由度，也为创新教育的主渠道-课程教学和创新教育的课外实践设置了不同阶段的追求目标。     

自我暗示法在耐久跑教学中的运用

耐久跑在体育教学中由于比其他项目枯燥,因而学生没有兴趣,学生在思想上和体力上容易产生疲劳。目前有关提高耐久跑兴趣的探讨很多,在某些方面也取得了突破性的进展。然而在提高学生练习中自控能力这个方面的研究还不多见。为此本人借这个机会就自我暗示法在耐久跑教学中如何帮助学生提高自控能力谈一点体会。     

地方普通高等学校办学定位探讨

地方普通高校是我国高等教育的重要组成部分，其办学定位如何直接决定着我国高．等教育的质量和水平。本文在对高等学校办学定位内涵分析的基础上，提出了地方普通高校的办学定位应具备的特征和依据，指出地方普通高校应面向地方经济社会发展的需要，开展应用技术研究，重点培养高等专业性、技术性人才。