Schedule-induced polydipsia contrast in the rat

Schedule-induced polydipsia was studied using a behavioral contrast paradigm. Food pellets were delivered to food-deprived rats on a response-independent FT 1-min schedule. Licking on a tube produced water on a MULT FR 10 FR 10, MULT FR 10 EXT, or MIXED FR 10 EXT for three rats (Experiment 1) and on a MULT VI VI, MULT VI EXT, or MIXED VI EXT schedule for three other rats (Experiment 2). On the FR schedules, rats could drink more water by increasing lick rates, but on the VI schedules the amount of drinking was fixed by the schedule parameters and was relatively unaffected by lick rates. Relative to MULT FR FR, positive polydipsia contrast was clearly demonstrated on MULT and MIXED FR EXT; but relative to MULT VI VI, contrast was not demonstrated on MULT and MIXED VI EXT. These data suggest that polydipsia contrast occurs only if increased licking permits increased drinking.     

A concurrent assessment of schedule-induced aggression and schedule-induced polydipsia in the rat

Rats subjected to FI 60-sec and FI 120-sec schedules of reinforcement were permitted concurrent access to a licking tube and a restrained target rat. While both polydipsia and attack occurred, polydipsia was the predominant scheduleinduced behavior. When attack occurred, and the licking tube was also available, attack usually followed licking in the interreinforcement interval. Eliminating access to the target did not influence polydipsia, and removal of the licking tube did not affect the frequency of aggressive episodes.     

Polydipsia and autoshaping: Drinking and leverpressing as substitutes for eating

Three experiments delivered food at fixed or random intervals independently of the rat’s behavior, always less than the amount eaten with food freely available. The results revealed a Polydipsie response to this experimental suppression of eating, and total drinking decreased as total eating increased. When we added a lever that signaled each food delivery, leverpressing and drinking rose far above their baseline levels; both responses decreased as total eating increased. When a similar schedule presented lever and food independently, rats still became Polydipsie, but showed no sign of autoshaped leverpressing. A fourth experiment revealed a hypophagic response to schedules that suppressed drinking; total eating increased with total drinking. As mutual substitutes in the economic sense, one behavior falls as the other rises; as mutual complements in the economic sense, the two behaviors rise or fall together. We discuss polydipsia and autoshaping in terms of drinking as an intrinsic substitute for eating, and leverpressing as a learned substitute for eating. The results suggest a revision of conservation theory, which views drinking and eating as substitutes when the schedule suppresses eating but as complements when the schedule suppresses drinking.     

Temporal factors influencing the acquisition and maintenance of an autoshaped keypeck

Food-deprived pigeons were given briei meals of grain following the presentation of a lignt on a response key. Pecking the key had no consequence Virtually all of the pigeons pecked the lignted key. The number of trials prior to the first peck varied inversely witn the value of the mean interval between light onsets. Trials to criterion was a negative power function of the value of the intertrial interval. The addition of a second stimulus, never followed by food, retarded the acquisition of the keypeck, particularly at short intertriai intervals. During steady state performance, the value of two measures of response strength, rate and probability of responding, increased as a function of the duration of the intertriai interval.

     

Frustration and the production of schedule-induced polydipsia

In two experiments, the hypothesis that frustration mediates the production of schedule-induced polydipsia was tested. In Experiment I, a group in which reward was reduced from 6 to 2 pellets of food in an operant chamber was found to increase water intake compared to a group maintained at 2 pellets reward. In Experiment II, rats trained to approach food on a partial reinforcement schedule in a runway subsequently showed lower levels of water intake in the operant test for polydipsia than rats given continuous reinforcement during runway training. The results are interpreted as supporting a frustration hypothesis of schedule-induced polydipsia and are discussed within the context of persistence theory.     

A binomial test of model fit

An alternative method for determining the goodness of fit of a proposed theoretical model is presented and applied to a simple case to illustrate its 0use. The method is based on the application of the binomial distribution to the number of paths in a model that are supported by the data. This method is a different conceptual approach than those traditionally used in structural equation modeling studies.     

Support for development and test of web application: A tree-oriented model

Building an abstract model of the web application is the chief task of software test based on model, which is an efficient way for testing the web application. One problem with current web application test technologies is the lack of tools for modeling the whole web software, especially the lack of support for describing web application from the view of action and function. This paper is concerned with providing the support for development and test of the web application. The presented novel model, named component-based and tree-oriented web application development model (CBTOWADM), abstracts the web application as a tree based on its system function and business process. CBTOWADM not only simplifies the design and development of the web application, but also acts as the model middleware for software test. The basic model definition, the system framework and the application in software test of CBTOWADM is described.     

A reevaluation of the CS− hypothesis for schedule-induced polydipsia under intermittent schedules of pellet delivery

Lashley and Rosellini (1980) have recently suggested that schedule-induced polydipsia (SIP) is determined by the occurrence of absolute periods within schedules of periodic food delivery which are associated with a low probability of food delivery, that is, CS? periods. To assess this hypothesis, SIP was examined in the present experiments under three schedules—fixed time, variable time, and random time (RT)—which differed in probability of occurrence and/or duration (Experiment 1), and under a range of RT schedules in which the CS? period was systematically varied by changing the interpellet interval (Experiment 2). In both experiments, the level and temporal distribution of SIP did not seem to be related to the absolute period associated with the absence of food. Instead, SIP was more systematically related to the average length of the interpellet interval and, therefore, to the average period associated with no food. It was suggested that drinking under intermittent schedules of pellet delivery, that is, SIP, is determined by an average CS? period and not by an absolute period associated with the unavailability of food.     

Taste aversion learning and schedule-induced polydipsia in rats

Experiment 1 sought to determine whether schedule-induced drinking could be abolished by means of a taste aversion. Polydipsic rats were given access to a .4% saccharin solution while they were exposed to an intermittent food schedule. Immediately after the session, they received an intraperitoneal injection of either lithium chloride or sodium chloride. Following a recovery day with water in the experimental chamber, the animals were again exposed to the saccharin solution. The poisoned animals (lithium chloride) drank very little saccharin compared to the control animals (sodium chloride), indicating that they had learned a taste aversion in only one conditioning trial. Experiment 2 established that polydipsic rats can learn a taste aversion despite a long delay between schedule-induced saccharin consumption and poisoning, and that the delay gradient displayed by polydipsic rats is similar to that observed in thirst-motivated rats.     

Behavioral contrast as a function of component duration for leverpressing using a within-session procedure

Ten rats pressed levers for food reinforcers delivered by multiple schedules. Behavioral contrast was measured using a within-session procedure that presented the baseline and contrast schedules within single sessions. The absolute sizes of both positive and negative contrast increased and then decreased as components lengthened. Negative induction occurred when components were very short. These results question theories that predict that the size of contrast will vary inversely with component duration. They support theories that attribute positive and negative contrast to similar theoretical mechanisms. A comparison of the present results with those of past studies indicates that keypecking by pigeons and leverpressing by rats change as different functions of component duration. Treadlepressing by pigeons and leverpressing by rats change as similar functions. These findings challenge general process theories that argue that all responses obey the same behavioral laws.     

A model for increasing decision making potential through standardized test scores

The development of a model for more effective usage of group administered standardized tests is developed. The primary assumption is that summary data from these instruments are not used in curricular decisions for groups larger than the classroom unit, and a method is illustrated which uses item groupings from subtests allowing a more effective use of the data for program and curricular decisions. Several cautions are presented with respect to data usage in the recommended fashion, i. e., item data usually have low reliability coefficients, and criterion levels which identify problems in the curriculum are difficult to establish.     

Area-time associated test cost model for SoC and lower bound of test time

A novel test access mechanism (TAM) architecture with multi test-channel (TC) based on IEEE Standard 1500 is proposed instead of the traditional sub-TAM structure. The cost model of an area-time associated test and the corresponding lower bound of system-on-chip (SoC) test time are established based on this TAM architecture. The model provides a more reliable method to control the SoC scheduling and reduces the complexity in related algorithm research. The result based on the area time associated test cost model has been validated using the ITC’02 test benchmark.     

Ease of grading and enrollment in secondary school science. II. A test of the model

A proposed model of the effects of ease of grading in science on enrollments is tested with data gathered in 27 high schools. Grades were transcribed for students in the 1968 graduating class; they were coded A = 7, B+ = 6, B = 5, …, F = 0. East of grading was calculated for each science teacher and course in each school. In addition the proportion of non-senior students who moved from one science to the next in the typical sequence was determined. Analyses of variance indicated that teachers were the major distinguishable source of variance in ease of grading. Analysis of teachers' ease of grading indicated that female students were graded more severely than male students, and grading in the physical sciences was more severe than grading in biology. Analyses of the effects of ease of grading on students' transitions from course to course indicated that experienced ease or severity of grading was more important for female students than for male students, while anticipated ease or severity of grading was important for all transitions, except that of male students into physics. These results are taken as evidence supporting the first three propositions of the model, though it appears that some modification to account for sex differences will be appropriate. Estimates from the data suggest that an increase in science enrollments of practical significance would follow an effort to bring science grades to “par” with other academic grades. Finally it is noted that efforts to achieve effective general education in the sciences through attention to grading practices alone will probably be inadequate.     

制动器试验台的控制模型与分析

通过对制动器检测和控制原理的分析,建立了关于电动机驱动电流依赖于观测值（转速）的微分方程模型.然后,优化模型,把连续问题离散化,进而微分方程模型改进成差分方程模型（依赖于扭矩）,使其精确度大大提高,而且便于实现自动化控制.并把模型由水平制动推广到垂直制动.     

Control of drinking-bout magnitude in schedule-induced polydipsia by interpellet-interval duration

Schedule-induced polydipsia (SIP) is a function of interpellet-interval (IPI) durations: intermediate (40-180-sec) IPIs are most effective in producing SIP, while longer and shorter IPIs are increasingly less effective. In order to determine whether each IPI exerts its influence on SIP by regulating drinking during that IPI itself or during the immediately succeeding IPI, rats were presented with systematic sequences of IPI durations during individual sessions of SIP testing. It was found that a very brief (20-sec) IPI tended to reduce the duration of drinking during the ongoing IPI, but that a very long (4-min) IPI reduced the probability that any drinking would occur during subsequent IPIs. It was suggested that the motivation to drink is reduced following long IPIs, while feeding, or behaviors anticipatory to feeding, compete with drinking when IPI lengths are very short.     

信江贵溪城南段河道整治模型试验研究

通过建立信江贵溪城南段的定床实体模型,进行河工模型试验。研究现状和修改治导线不同频率洪水下,信江贵溪城南段水流运动特性,并对两个治导线方案下的试验成果进行比较,分析其对城市防洪的影响,提出了合理的防治措施。     

Authoritative schools: A test of a model to resolve the school effectiveness debate

School effectiveness research has fueled debate on the importance of a press for academic excellence versus communal values. Research on parenting styles offers a theoretical framework that may resolve the debate. We hypothesized that dimensions of parenting styles—demandingness (academic press) and responsiveness (communal values)—predict students’ mathematics achievement, engagement, and locus of control. HLM analyses of NELS: 88 data on 19,435 eighth-graders partially supported the hypothesis: Students’ perceptions of school responsiveness predicted their engagement and internal control. In addition, students in responsive schools had smaller differences in mathematics achievement and internal control attributable to SES, suggesting that responsive schools may increase equity. We offer suggestions for further investigation of the model in hope of resolving the debate.