Reactions of selectively bred strains of rats to a cat

Reactions of five strains of rat to a cat, a rabbit, and a box, all of comparable size and color, were investigated. The response measures were approach behavior score, general activity, percentage of activity in the neighborhood of the stimulus objects, rearing, defecation, latency to emerge, direction of emergence, and freezing and touching the stimulus objects. Rats avoided the cat, froze in the presence of the cat, and showed higher levels of emotional reactivity to the cat than to the rabbit or the box. The five strains of rat were more uniform in their reactions to the cat than to the rabbit or the box.     

Experiential factors in the enhancement of saccharin intake after shifts to water

The present experiment examined the enhancement of saccharin consumption observed after a temporary shift to water. An 8-day adaptation period of continuous access to saccharin was used. It was found that the avidity of albino rats for saccharin, as measured by daily consumption, can be increased significantly both by periods of saccharin deprivation and by social living conditions.     

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.     

Licking one saccharin solution for access to another in rats: Contingent and noncontingent effects in instrumental performance

Separation of the contingent and noncontingent effects of a schedule on amount of instrumental responding is desirable but difficult in schedules that involve instrumental and contingent responses that are either highly probable or very similar. Three studies in which rats were required to lick a solution of .1% saccharin for access to a preferred solution of .4% saccharin showed that neither single nor paired operant baselines of the instrumental response allowed accurate separation of the contingent and noncontingent effects of a fixed-ratio schedule. Two within-subject yoking procedures provided the best baselines of noncontingent effects: the massed baseline measured amount of .1% licking when each subject received free access to the total amount of .4% licking it obtained at asymptote under the schedule; the matched baseline measured .1% licking when each subject received the same access to the .4% solution, but presented in the intermittent pattern obtained during the schedule. Of the three algebraic models used to predict noncontingent effects, the substitution model was most promising, but still not adequate. The procedure of a between-subjects yoked control was also not effective.     

How early maternal separation and juvenile experience with pups affect maternal behavior and emotionality in adult postpartum rats

To assess the effects of preweaning and juvenile experiences on adult maternal behavior, two experiments were completed. In Experiment 1, pups were separated for long periods or short periods or were left undisturbed over the 1st week. Following weaning, the rats were exposed to foster pups over a 5-day period or were left undisturbed. There were no effects of early experience on juvenile behavior. In adult postpartum maternal tests, short separations reduced latencies to express maternal behaviors, whereas long separations combined with juvenile exposure to pups increased latencies. In Experiment 2, pups were separated for long periods or were left undisturbed over the 1st week. Following weaning, the rats were exposed to foster pups for 4 days or 8 days or were left undisturbed. Long separation retarded maternal responding in juvenile animals but had no effect on the adults. Four days of juvenile experience had negative effects on adult behavior, whereas 8 days did not have an effect.     

Differences in reading development among Danish beginning-readers with high versus low phonemic awareness on entering grade one

This longitudinal study explored the relation betweenpreschool phoneme awareness and initial reading development. Distinctions were made between formal and functional letter knowledge and between foundation and subsequent phases of reading development. 44 children with at least average language comprehension were followed from the beginning of grade 1(7 years) until the end of grade 2. They were divided intotwo groups: one group of 21 children with high phonemic awareness (HPA) and 23 children with low phonemic awareness (LPA) on entering grade 1. The results showed persistent group differences in favour of the HPA children regarding letter-knowledge and word reading. The results confirmed a significant impact of functional letter knowledge on the length of the foundation period and on later reading development. Length of foundation period was shown to have a significant impact on reading development at the end of grades 1 and 2. It is argued that phonemic awareness is an indispensable catalystin the development of initial word processing ability.     

Place versus response learning in rats

In previous research designed to test whether place learning or response learning proceeds more quickly and better in rats,place has not been defined unambiguously when direction has been controlled by moving an apparatus around in the test room (Blodgett, McCutchan, & Mathews, 1949; Skinner et al., 2003). In Experiment 1, we compared place and response learning while controlling direction in a static apparatus, thus making the meaning of place unambiguous. The performance of rats that had to make different turns to find food in a particular place and rats that had to always make the same turn to find food in two different places did not differ. In Experiment 2, visual cues were made equally discriminable for place and response learners in a static apparatus. Place learners still failed to outperform response learners, but there was evidence that response biases interfered more with place than with response learning. The results are discussed with reference to the historical debate that generated the original research and also in terms of more contemporary spatial-learning issues in rats.     

A sequential analysis of responses in online debates to postings of students exhibiting high versus low grammar and spelling errors

Given that grammatical and spelling errors have been found to influence perceived competence and credibility in written communication, this study examined how a student’s grammar and spelling errors affect how other students respond to the student’s postings in four online debates hosted in asynchronous threaded discussions. Message-response exchanges were sequentially analyzed to identify patterns in students’ replies to arguments and challenges with counter-challenges, explanations, and evidentiary support posted by students that exhibited low versus high number of grammatical and spelling errors. Although no causal inferences can be drawn from this study, the findings nevertheless suggests that: (a) arguments posted by high-error students are more likely to be challenged than arguments posted by low-error students; (b) exchanges between high-error students can amplify the effects of grammar/spelling errors; and (c) higher levels of argumentation can be achieved by placing students into groups that are heterogeneous in writing skills in general. The findings and methods used in this study lay the groundwork for further research on strategies for managing individual differences in students’ grammar and spelling (and other student behaviors in general) and increasing the level of critical discourse in online discussions.     

品读《殷周制度论》

王国维所作《殷周制度论》一经出版就引起学术界的高度重视,历经一个世纪其经典地位未曾动摇.近年来,随着考古学的新发现,历史学的新研究,书中的很多观点受到了质疑,基于此有必要对经典再品读.文章结合王氏所处的历史背景和文献资料,从其作《殷周制度论》的立意和采用的研究方法两个方面解读经典,还原王氏试图用封建秩序拯救乱世的立意,重新认识先生以史作论的严谨治学态度和“二重证据法”的实际运用,从而推动中国古史研究进一步深入.     

Meal size and intermeal interval both regulate schedule-induced water intake in rats

The present studies examined the effects of intermeal interval and pellet magnitude on the development and maintenance of schedule-induced polydipsia using a between-subjects design as contrasted with earlier investigations, which have exclusively employed within-subject procedures. In Experiment 1, pellets were delivered on one of six fixed-time schedules (20, 40, 60, 120,180, and 240 sec) to different groups of rats. Although the typical bitonic function relating water intake to intermeal interval was obtained, the function showed a wide plateau ranging from 60 to 180 sec. Experiment 2 demonstrated that both intermeal interval and pellet magnitude regulate schedule-induced polydipsia. While small-magnitude pellets could support drinking only at relatively short intermeal intervals, increasing pellet magnitude to medium or large resulted in drinking at progressively longer intermeal intervals. Indeed, we observed drinking on a fixed-time 720-sec schedule with large-magnitude pellets. These findings are derivable from the opponent-process theory of acquired motivation.     

Emotion recognition ability in mothers at high and low risk for child physical abuse

OBJECTIVE: The study sought to determine if high-risk, compared to low-risk, mothers make more emotion recognition errors when they attempt to recognize emotions in children and adults. METHOD: Thirty-two demographically matched high-risk (n = 16) and low-risk (n = 16) mothers were asked to identify different emotions expressed by children and adults. Sets of high- and low-intensity, visual and auditory emotions were presented. Mothers also completed measures of stress, depression, and ego-strength. RESULTS: High-risk, compared to low-risk, mothers showed a tendency to make more errors on the visual and auditory emotion recognition tasks, with a trend toward more errors on the low-intensity, visual stimuli. However, the observed trends were not significant. Only a post-hoc test of error rates across all stimuli indicated that high-risk, compared to low-risk, mothers made significantly more emotion recognition errors. Although situational stress differences were not found, high-risk mothers reported significantly higher levels of general parenting stress and depression and lower levels of ego-strength. CONCLUSIONS: Since only trends and a significant post hoc finding of more overall emotion recognition errors in high-risk mothers were observed, additional research is needed to determine if high-risk mothers have emotion recognition deficits that may impact parent-child interactions. As in prior research, the study found that high-risk mothers reported more parenting stress and depression and less ego-strength.     

What is "high"? The development of reference points for "high" and "low"

Young children have been characterized as interpreting relative adjectives as if they were nominal or categorical terms. The categorical interpretation of relative terms, however, may be quite complex. Indeed, the mature understanding of relative terms would seem to include a complex system of reference points for the terms' categorical usages. In 5 experiments we examined the complexity of 3-5-year-old children's and adults' categorical interpretations. We specifically examined how reference points for the categorical interpretation of high and low are defined. The definition of reference points relative to the object judged, the vertical position of the observer, and the extent of vertical variation were assessed. 3 major developmental trends were observed: a trend from the application of the terms to only extreme values to their application to broader categories; a trend from nominal-like categories to ones defined flexibly relative to context (e.g., nature of object judged, and extent of vertical variation); and a trend from reference points functioning as focal points to their operating as directional category boundaries. In brief, the results suggest that the categorical usage of relative terms involves a rich and intricate knowledge system and that it takes children considerable time to acquire and organize the relevant pieces of knowledge.     

Linguistic processing in Hebrew-speaking children from low and high SES backgrounds

The aim of this study was to investigate the impact of Socio-Economic Status (SES) on Hebrew-speaking children??s developing ability to pluralize nouns and mark adjectives in agreement with them. Participants were 180 gradeschool children from mid-high SES and 180 peers from low SES, in six consecutive grade levels. The task consisted of 32 singular noun-adjective pairs with nouns classified into four categories by suffix type (Regular and Irregular) and by stem type (Nonchanging and Changing). Results showed a consistent advantage to the high SES children in accuracy of noun and adjective plurals, with gaps widening when the morphological requirements were harder, that is, in the irregular categories. Moreover, the fact that low SES children??s reaction times to producing the full plural phrase hardly decreased indicates that, unlike their high SES peers, they also did not gain more processing efficiency with age and schooling.     

数学教育贵在尚识

教学具有教育性,数学而言的“识”是指分析鉴别知识经融会贯通而获致个人见解的能力,包括预见力、判断力、鉴赏力、洞察力、看问题的能力、提问题的能力.尚识要兼顾“才、学、识”3者的关系,遵循识的生长的3个阶段,引导和培育学生的识.     

The effects of visual complexity for Japanese kanji processing with high and low frequencies

The present study investigated the effects of visual complexity for kanji processing by selecting target kanji from different stroke ranges of visually simple (2–6 strokes), medium (8–12 strokes), and complex (14–20 strokes) kanji with high and low frequencies. A kanji lexical decision task in Experiment 1 and a kanji naming task in Experiment 2 were administered to native Japanese speakers. Results of both experiments showed that visual complexity inhibited the processing of low-frequency kanji, whereas such consistent, inhibitory effects of visual complexity were not observed in the processing of high-frequency kanji. Kanji with medium complexity were processed faster than simple and complex kanji in high frequency.     

一种应用于高速低抖动电荷泵锁相环的高鲁棒性鉴频鉴相器

为改善现有鉴频鉴相器（PFD）中存在的问题,从理论分析的角度对现有的PFD进行了研究,并对其进行了基于电路结构的分类与比较．提出并设计了一种应用于高速低抖动电荷泵锁相环的高鲁棒性新型鉴频鉴相器．该PFD由2个上升沿触发的动态D触发器、2个上升沿检测和延时模块及2个或门组成．由于融合了2种复位机制,能避免UP与DN信号同时为高电平,因此,电荷泵的电流失配将不会恶化PLL的性能．而且,该PFD的鉴相特性中几乎没有鉴相死区、设计及仿真是基于1．8V电源电压的TSMC0．18ixmCMOS工艺．由理论推导和电路仿真可知,该PFD具有高工作频率（-1GHz）、高可靠性、宽鉴相范围（[±2π]）、零死区（〈0.1ps）、低抖动、低功耗（≈100μw）、低复杂度等特性、     

Taste potentiates color-sickness associations in pigeons and quail

The present experiments assessed cue utilization in pigeons and quail on similar tests of poison-based aversion learning. In Experiments 1 and 2, three groups of pigeons were given colored water, flavored water, or colored flavored water prior to induction of sickness; these experiments differed only as to the specific colors and flavors used as stimuli. In both experiments, the birds trained with flavored water exhibited reliable taste aversions when tested with uncolored flavored water. Similar degrees of aversion were observed whether the flavored water had been colored or uncolored during training, suggesting that the color cue had little or no effect on the conditioning of the flavor cue. In contrast, the flavor cue had a pronounced effect on the conditioning of the color cue. When tested with unflavored colored water, the birds trained with colored flavored water exhibited significantly stronger color aversions than those trained with unflavored colored water. That is, the flavor cue enhanced or potentiated the conditioning of the color cue. In a third experiment, quail were trained in the same way as the pigeons with virtually the same result. The pattern of cue utilization observed in the present experiments with pigeons and quail differs markedly from that proposed by Wilcoxon, Dragoin, and Kral (1971) for quail. However, a reexamination of the results obtained by Wilcoxon et al. suggested that they are susceptible to an alternative interpretation consistent with the present results.