Scaling behavior of nucleotide cluster in DNA sequences

In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P（S） ∝ e^-αs＇ where S represents nucleotide cluster size. The cluster-size distribution P（S1＋S2） with the total size of sequential C-G cluster and A-T cluster S1＋S2 were also studied. P（S1＋S2） follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L（n） and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.     

Effects of different sequences of examples and problems on motivation and learning

Recent research has shown that example study only (EE) and example-problem pairs (EP) were more effective (i.e., higher test performance) and efficient (i.e., attained with less effort invested in learning and/or test tasks) than problem-example pairs (PE) and problem solving only (PP). We conducted two experiments to investigate how different example and problem-solving sequences would affect motivational (i.e., self-efficacy, perceived competence, and topic interest) and cognitive (i.e., effectiveness and efficiency) aspects of learning. In Experiment 1, 124 technical students learned a mathematical task with the help of EEEE, EPEP, PEPE, or PPPP and then completed a posttest. Students in the EEEE Condition showed higher posttest performance, self-efficacy, and perceived competence, attained with less effort investment, than students in the EPEP and PPPP Condition. Surprisingly, there were no differences between the EPEP and PEPE Condition on any of the outcome measures. We hypothesized that, because the tasks were relevant for technical students, starting with a problem might not have negatively affected their motivation. Therefore, we replicated the experiment with a different sample of 81 teacher training students. Experiment 2 showed an efficiency benefit of EEEE over EPEP, PEPE, and PPPP. However, only EEEE resulted in greater posttest performance, self-efficacy, and perceived competence than PPPP. We again did not find any differences between the EPEP and PEPE Condition. These results suggest that, at least when short training phases are used, studying examples (only) is more preferable than problem solving only for learning. Moreover, this study showed that example study (only) also enhances motivational aspects of learning whereas problem solving only does not positively affect students’ motivation at all.     

Emotional design in multimedia learning: Effects of shape and color on affect and learning

We examine design factors that may evoke positive emotions in learners and investigate the effects of these positive emotions on learning. Recent research showed that the emotional design of multimedia learning material can induce positive emotions in learners that in turn facilitate comprehension and transfer. We sought to replicate these results with a different population and different mood induction procedure and examine individual emotions, and to decompose the effects of the design elements of color and shape. Study 1 showed that well-designed materials induced positive emotions and facilitated comprehension, though transfer performance was not affected by emotional design. Study 2 found that round face-like shapes both alone and in conjunction with warm color induced positive emotions. Warm colors alone, however, did not affect learners' emotions. Comprehension was facilitated by warm colors and round face-like shapes, independently as well as together. Transfer was facilitated by round face-like shapes when used with neutral colors.     

优化高校资产配置的精细化管理方法

探讨了高校资产配置精细化管理的内涵,介绍了首都医科大学进行资产配置管理的工作实践,提出以资产管理的精细化管理为着眼点,细化资产配置标准,实现对存量资产的宏观调控,强化资源配置的合理性和有效性,建设节约型高校。     

Intentionality as measured in the persistence and elaboration of communication by chimpanzees (Pan troglodytes)

In human infancy, 2 criteria for intentional communication are (a) persistence in and (b) elaboration of communication when initial attempts to communicate fail. Twenty-nine chimpanzees (Pan troglodytes) were presented with both desirable (a banana) and undesirable food (commercial primate chow). Three conditions were administered: (a) the banana was delivered (successful communication), (b) half of the banana was delivered (partially successful communication), and (c) the chow was delivered (failed communication). The chimpanzees exhibited persistence in and elaboration of their communication in every condition except when the banana was delivered. Thus, their communication was about a specific item, demonstrating that both intentionality and nonverbal reference are capacities shared by humans with our nearest living relatives, the great apes.     

Effects of maze geometry and experience on exploratory behavior in the rat

Rats were exposed twice in a rotated sequence to a series of six mazes, consisting of hexagonal alleys, balanced for different alley length and structural complexity. Locomotor activity increased with alley length and decreased with structural complexity of the mazes. Locomotion became less stereotyped with increased experience, showing an increasing number of turns, less constant velocity, loss of the initial preference for outward leading alleys and weakening of the forward tendency at reentry from side alleys into hexagonal alleys. In contrast to these qualitative changes of locomotion, the amount of activity remained almost unchanged throughout the experiment. The results suggest that these increases in locomotion complexity depend upon complex interactions between experience and stimulus content of the mazes.     

Effects of environmental novelty on filial behavior in imprinted ducklings

Environmental novelty was manipulated in imprinted ducklings by varying the illumination level of the experimental apparatus. Bright illumination disrupted filial behavior in subjects that had received little prior exposure to the imprinting object, with approach being suppressed more when the object was stationary than when it was moving. In subjects with prolonged prior imprinting exposure, bright illumination enhanced filial behavior. These effects can be understood if one assumes that environmental novelty has an energization effect while also eliciting responses that are incompatible with filial behavior.     

Effects of prior response-contingent reinforcement on superstitious behavior

Three pigeons were exposed to fixed-time (FT) 15 sec, fixed-interval (FI) 15 sec for performing an arbitrary response, a reversal back to FT 15 sec, and then extinction (no reinforcement). During each phase, a computer-controlled tracking system continuously recorded the position of the bird’s head as it moved freely in the experimental chamber. During the first exposure to FT 15 sec, all 3 birds developed a pattern of feeder-wall-directed behavior with occasional circular excursions from the feeder immediately following reinforcement. During FI 15 sec, all birds performed the arbitrary operant, which consisted of contacting a virtual target sphere near the rear of the chamber, and did not engage in feeder-wall-directed behavior. During the reversal back to FT 15 sec, the birds developed a behavior sequence consisting of moving in the direction of the target sphere after reinforcement, followed by feeder-wall-directed behavior prior to the next reinforcement. During extinction, either moves toward the target sphere or wall-directed behavior occurred separately, interspersed with reappearance of the two as a sequence, followed by cessation of both members of the behavior sequence. These findings indicate that prior reinforcement of an arbitrary response can affect the location and form of superstitious behavior that develops near the beginning of the interreinforcement interval, but that other factors (e.g., immediacy of reinforcement) affect the location and form of the behavior near the end of the interval. The findings can be interpreted in the context of superstitious chaining.     

Collaborative learning tasks and the elaboration of conceptual knowledge

In this article we present the results of an experimental study of the influence of task characteristics on the characteristics of elaboration of conceptual knowledge in social interaction. With a pre-test and post-test we measured individual learning outcomes. We constructed a coding scheme that focuses on the communicative functions and propositional content of utterances and on elaborative episodes. The subjects were 40 students who worked in dyads on a collaborative task about electricity in one of four conditions. We compared a concept mapping task with a poster task and investigated the effect of a phase of individual preparation. The post-test scores were significantly higher than the pre-test scores. Individual preparation created better learning results and the asking of more questions. The concept mapping conditions showed more discussion of electricity concepts, collaboratively elaborated conflicts and reasoning, but no higher individual learning outcomes. In the concept mapping conditions, elaboration was related to individual learning outcomes.     

The effect of systematic training in elaboration on word meaning and prose comprehension in poor readers

This paper reports two interrelated, exploratory training studies to promote word knowledge and textual comprehension through elaboration in poor readers compared with their controls. The results suggest that systematic, sustained in situ training helped these poor readers, although both the training approaches and stimulus materials would need refinement. The study was assisted in part by the Social Sciences and Humanities Research Council of Canada with SSHRCC research grants Nos. 410-87-0058 and 410-89-0128 awarded to Che Kan Leong.     

Effects of exteroceptive feedback and safe-box confinement durations on escape behavior in rats

In Experiment 1, rats received escape training in which an exteroceptive feedback cue occurred in the safe box, and safe-box confinement durations of 5 or 20 sec were combined orthogonally with shock-box confinement durations of 5 or 20 sec. Exteroceptive feedback reliably facilitated escape performance relative to no-feedback controls when safe-box confinement was relatively longer than shock-box confinement. Confinement duration also facilitated performance in the absence of exteroceptive feedback. In Experiment 2, escape training with or without feedback was followed by extinction either with the feedback condition of prior training or with the opposite feedback condition. Feedback presentations in extinction reliably increased responding. Feedback removal reliably decreased responding relative to feedback controls. Introduction of feedback in extinction reliably enhanced performance relative to no-feedback controls.     

李瑞环对传统“和谐”思想的阐发和运用

李瑞环是中国共产党第三代领导集体的重要成员之一,他继承和阐发了中国传统文化中的“和谐”思想,并将其成功地运用到党的思想政治工作和统战工作中去。他的这一阐发和运用,对我们正确理解传统文化中的和谐思想,并用于今天建设社会主义和谐社会的伟大实践,具有重要的理论和实际意义。     

论汉赋的地理铺陈及渊源

汉赋以铺陈之法来体物,就汉大赋主要类型与代表性的篇目来看,它的铺陈是一种地理铺陈,亦即刘勰所说的“体国经野”。《西都赋》《上林赋》诸篇皆可为证。汉赋的地理铺陈渊源久远,它源于贡赋制度。贡赋各有等差,故须罗列分明,此乃铺陈之源;贡赋附着于土地,故与地理密切关联,此系地理表现之源。贡赋之地理铺陈于《禹贡》已见端倪,但对《诗经》赋法的片面理解导致未能追溯到汉赋地理铺陈的贡赋之源。     

Effects of stimulus change in prepunishment alley segments on self-punitive behavior

Three experiments investigated the effects of stimulus change during extinction on self-punitive behavior. In Experiment 1, changing alley brightness cues in all three segments of the alley prior to extinction eliminated self-punitive behavior. That is, subjects given shock in the third alley segment during extinction did not differ from nonshocked subjects in alley speed or in the number of trials to extinction. In Experiment 2, with shock also administered in the third alley segment, self-punitive behavior was eliminated when the stimulus change was made in segment 1 or in segments 1 and 2 but was obtained when the change occurred in segment 2 or in the lower startbox. In Experiment 3, shock was administered in the second alley segment. Self-punitive behavior was not obtained when the lower startbox cues were changed but was obtained with stimulus change in the upper startbox or in segment 1. The results are consistent with an expanded version of the Mowrer-Brown conditioned-fear hypothesis.     

Effects of preweaning environmental enrichment on later problem-solving behavior in rats

Two experiments investigated the importance of visual sensory modality in mediating enriched environmental effects during the preweaning period, and the importance of onset and duration of the enriched experience during the same period. Rat mothers and pups were exposed together in an enriched environment for either 7 or 11 days at different periods from Day 1 to Day 21. Also included was a group of rats which received only handling from Day 11 to Day 21 postpartum and another group in which the mothers were exposed to the enriched environment during the last trimester of pregnancy. Some rats were tested at 27 days of age, and others were tested at 64 days of age in the Hebb-Williams maze test. It was found that exposure in the enriched environment for a period of 7 days before the eyes opened improved rats’ problem-solving behavior above that of control rats and to the level of rats which received such experience after the eyes had opened. Handling of rats did not improve problem-solving behavior, nor did exposure during the gestation period. It was concluded that vision is not the most important factor in mediating effects during the preweaning period, since improvement in problem-solving behavior can occur before the visual system is fully developed. It was suggested that the beneficial enrichment effects might be mediated by the mother, who, in some way, transmits additional stimulation to the infant rat during this early stage of development.