Memory span for heterospecific individuals' odors in an ant, Cataglyphis cursor

Only recently have researchers studied the ability of ants to learn and remember individual heterospecific odors. Cataglyphis cursor adults have the capacity to learn these odors, but the duration of their memory and the factors that affect its formation remain unknown. We used a habituation/discrimination paradigm to study some of these issues. C. cursor adult workers were familiarized to an anesthetized Camponotus aethiops on four successive encounters. Then they were either isolated or placed with 20 nestmates for a certain length of time before undergoing a discrimination test that consisted of reintroducing the familiar C. aethiops, as well as introducing an unknown member of the same colony. The results showed that adult C. cursor ants can retain in memory a complex individual odor for at least 30 min, as well as differentiate it from the odor of another closely related individual. However, when ants were replaced in a rich social background between the habituation and the discrimination trials, we did not observe a significant discrimination between the known and unknown C. aethiops ants. Our study shows, for the first time, the existence of long-term memory for individual odors in mature ant workers.     

基于核心路由器的蚂蚁算法在大规模网络中的应用

蚂蚁算法在大规模网络寻找最优路径速度较慢,无法对最优路径进行数据流量控制。本文提出基于核心路由器的蚂蚁算法,通过从网络的各个核心路由器出发并行寻找最优路径,可以加快寻找最优路径的速度,并且能根据网络状况自动分流数据,这样可以保证网络的服务质量。     

Avoidance of interspecific mating in female Syrian hamsters is stronger toward familiar than toward unfamiliar heterospecific males

Adult Syrian hamster females (Mesocricetus auratus) learn to discriminate against familiar heterospecific males (Turkish hamster, M. brandti). We investigated whether females learn to avoid any heterospecific male after exposure to just one heterospecific male. We predicted that, after being exposed to one heterospecific male, a female would avoid mating not only with that familiar male but also with any unfamiliar heterospecific male. We exposed females to a heterospecific male across a wire-mesh barrier for 8 days and then paired the female with (a) that same heterospecific male or (b) an unfamiliar heterospecific male. Females exhibited lordosis faster and for a longer duration toward the unfamiliar than toward the familiar heterospecific male. However, females were similarly aggressive toward familiar and unfamiliar heterospecific males. Perhaps exposure to stimuli from several heterospecific males (a likely scenario in the wild) would result in females behaving similarly toward familiar and unfamiliar heterospecific males.     

Six-month-old infants' categorization of containment spatial relations

Six-month-old infants' ability to form an abstract category of containment was examined using a standard infant categorization task. Infants were habituated to 4 pairs of objects in a containment relation. Following habituation, infants were tested with a novel example of the familiar containment relation and an example of an unfamiliar relation. Results indicate that infants look reliably longer at the unfamiliar versus familiar relation, indicating that they can form a categorical representation of containment. A second experiment demonstrated that infants do not rely on object occlusion to discriminate containment from a support or a behind spatial relation. Together, the results indicate that by 6 months, infants can recognize a containment relation from different angles and across different pairs of objects.     

Socially biased learning in monkeys

We review socially biased learning about food and problem solving in monkeys, relying especially on studies with tufted capuchin monkeys (Cebus apella) and callitrichid monkeys. Capuchin monkeys most effectively learn to solve a new problem when they can act jointly with an experienced partner in a socially tolerant setting and when the problem can be solved by direct action on an object or substrate, but they do not learn by imitation. Capuchin monkeys are motivated to eat foods, whether familiar or novel, when they are with others that are eating, regardless of what the others are eating. Thus, social bias in learning about foods is indirect and mediated by facilitation of feeding. In most respects, social biases in learning are similar in capuchins and callitrichids, except that callitrichids provide more specific behavioral cues to others about the availability and palatability of foods. Callitrichids generally are more tolerant toward group members and coordinate their activity in space and time more closely than capuchins do. These characteristics support stronger social biases in learning in callitrichids than in capuchins in some situations. On the other hand, callitrichids’ more limited range of manipulative behaviors, greater neophobia, and greater sensitivity to the risk of predation restricts what these monkeys learn in comparison with capuchins. We suggest that socially biased learning is always the collective outcome of interacting physical, social, and individual factors, and that differences across populations and species in social bias in learning reflect variations in all these dimensions. Progress in understanding socially biased learning in nonhuman species will be aided by the development of appropriately detailed models of the richly interconnected processes affecting learning.     

Socially facilitated drinking behavior in chicks (Gallus domesticus): Relative effects of drive and stimulus mechanisms

The drinking behavior of individual chicks (n = 168) was studied in two discrimination situations when the individual was alone or with an audience of merely present (not drinking) or coacting (drinking) conspecifics. In one discrimination task, a familiar and an unfamiliar drinking tube (FU) were presented simultaneously; in the other discrimination task, two unfamiliar tubes (UU) were presented. The coacting audience received a familiar and an unfamiliar tube; their familiar tube was always unfamiliar to the subject. Subjects drank more when conspecifics were present, intake being highest in the presence of coacting conspecifics. Intake was higher in the FU discrimination than in UU. However, in the UU discrimination, individuals that were tested with coactors drank most of their total intake from the tube that was similar to the coactors’ familiar tube. In the FU task, individual subjects drank mostly from their familiar tube in each social condition. However, this effect was smaller for those tested with coacting conspecifics than for those tested with merely present conspecifics.     

Transfer of Nature of Science Understandings into Similar Contexts: Promises and Possibilities of an Explicit Reflective Approach

The purpose of this study was to (a) investigate the effectiveness of explicit nature of science (NOS) instruction in the context of controversial socioscientific issues and (b) explore whether the transfer of acquired NOS understandings, which were explicitly taught in the context of one socioscientific context, into other similar contexts (familiar and unfamiliar) was possible. Participants were 10th grade students in two intact sections at one high school. The treatment involved teaching a six-week unit about genetic engineering. For one group (non-NOS group), there was no explicit instruction about NOS. For the other group (NOS group), explicit instruction about three NOS aspects (subjective, empirical, and tentative) was dispersed across the genetic engineering unit. A questionnaire including two open-ended scenarios, in conjunction with semi-structured interviews, was used to assess the change in participants’ understandings of NOS and their ability to transfer their acquired understandings into similar contexts. The first scenario involved a familiar context about genetically modified food and the second one focused on an unfamiliar context about water fluoridation. Results showed no improvement in NOS understandings of participants in the non-NOS group in relation to the familiar and unfamiliar contexts. On the other hand, there was a general improvement in the NOS understandings of participants in the NOS group in relation to both the familiar and unfamiliar contexts. Implications about the transfer of participants’ acquired NOS understandings on the basis of the distance between the context of learning and that of application are highlighted and discussed in link with the classroom learning environment.     

Only Familiar Information is a “Curse”: Children’s Ability to Predict What Their Peers Know

The ability to make inferences about what one’s peers know is critical for social interaction and communication. Three experiments (n = 309) examined the curse of knowledge, the tendency to be biased by one’s knowledge when reasoning about others’ knowledge, in children’s estimates of their peers’ knowledge. Four- to 7-year-olds were taught the answers to factual questions and estimated how many peers would know the answers. When children learned familiar answers, they showed a curse of knowledge in their peer estimates. But, when children learned unfamiliar answers to the same questions, they did not show a curse of knowledge. These data shed light on the mechanisms underlying perspective taking, supporting a fluency misattribution account of the curse of knowledge.     

基于改进蚁群遗传算法的排课问题研究

提出了一种以蚁群算法为主,利用遗传算法经过交叉,变异,选择后产生进化的信息素作为蚁群使用的信息素.在遗传算法多次进化效果不明显时,引入模拟退火算法进行跳变的混合算法,使各种算法取长补短,改善了蚁群算法初始阶段运行缓慢和遗传算法局部搜索能力弱的缺点.提高了运行效率,同时运用这种改进的算法对高校排课问题进行仿真,从而比较算法改进的优缺点.     

New approaches to the inservice education in science and technology of primary and early childhood teachers (or mum is not dumb after all!)

Conclusion These preliminary findings have implications for the effective inservicing of early childhood and primary teachers in the science and technology areas. They are also likely to have implications for preservice courses. The research findings indicate that teachers can overcome their often negative views of science and of science teaching. Factors significant in this process appear to be: firstly, and most importantly, experience by the teachers of support and acceptance as they begin—often anxiously-their explorations of science, science teaching and learning. Secondly, teachers begin their investigations in a context with which they are familiar, from the point “where they are at” and hence from which they can develop their investigations in directions they perceive to be the most fruitful. Thirdly, the sharing of explorations, reflections and progress amongst group members encourages the teachers to clarify and justify their own directions and perspectives, to learn of others' journeys, and to receive affirmation of their own learning. it is clear that this complex process cannot be hurried: inservicing teachers in an area that has been so neglected in the school curriculum requires an approach that fully recognises this.     

Neural correlates of face and object recognition in young children with autism spectrum disorder,developmental delay,and typical development

This study utilized electroencephalographic recordings to examine whether young children with autism spectrum disorder (ASD) have impaired face recognition ability. High-density brain event-related potentials (ERPs) were recorded to photos of the child's mother's face versus an unfamiliar female face and photos of a favorite versus an unfamiliar toy from children with ASD, children with typical development, and children with developmental delay, all 3 to 4 years of age (N = 118). Typically developing children showed ERP amplitude differences in two components, P400 and Nc, to a familiar versus an unfamiliar face, and to a familiar versus an unfamiliar object. In contrast, children with ASD failed to show differences in ERPs to a familiar versus an unfamiliar face, but they did show P400 and Nc amplitude differences to a familiar versus an unfamiliar object. Developmentally delayed children showed significant ERP amplitude differences for the positive slow wave for both faces and objects. These data suggest that autism is associated with face recognition impairment that is manifest early in life.     

Preferential approach to conspecifics as a function of different rearing conditions

Forty-six White Leghorn chicks were tested at 48 h posthatch to determine their ability to discriminate and preferentially respond to individual companions and strangers. In the first experiment, socially reared chicks showed no preference when allowed a simultaneous choice between either a familiar or an unfamiliar socially reared chick. In the second experiment, socially reared chicks preferred (p = .012) an unfamiliar socially reared chick to an unfamiliar chick reared in isolation. In the third experiment, chicks reared in isolation preferred (p = .036) a socially reared chick to an isolation-reared chick. Results indicate that chicks 48 h old respond to others on the basis of behavioral as well as morphological characteristics.     

By 4.5 Months,Linguistic Experience Already Affects Infants’ Talker Processing Abilities

Contemporary models of adult speech perception acknowledge that the processing of linguistic and nonlinguistic aspects of the speech signal are interdependent. But when in development does this interdependence first emerge? In the adult literature, one way to demonstrate this relationship has been to examine how language experience affects talker identification. Thus, in this study, 4- to 5-month-old infants (N = 96) were tested on their ability to tell apart talkers in a familiar language (English) compared to unfamiliar languages (Polish or Spanish). Infants readily distinguished between talkers in the familiar language but not in the unfamiliar languages, supporting the hypothesis that the integrated processing of linguistic and nonlinguistic information in speech is early emerging and robust.     

Teaching and Learning About Inquiry: Insights and Challenges in Professional Development

The purpose of this study was to determine if teachers who participated in a professional development program continued to learn about inquiry and inquiry teaching as they implemented inquiry in their classrooms. A qualitative design utilizing inductive analysis was used to investigate teachers’ understanding and classroom implementation of inquiry. Findings are presented as assertions, drawing support from four focal teachers. For each assertion, confirming and disconfirming data are presented. Based on these data, we assert that a) there was little or no change in teachers’ individual understanding of inquiry, and b) professional development enhanced teachers’ ability to design inquiry-based activities – however, classroom implementation did not reflect a high level of inquiry.     

Preschoolers are sensitive to the speaker's knowledge when learning proper names

Unobservable properties that are specific to individuals, such as their proper names, can only be known by people who are familiar with those individuals. Do young children utilize this “familiarity principle” when learning language? Experiment 1 tested whether forty-eight 2- to 4-year-old children were able to determine the referent of a proper name such as “Jessie” based on the knowledge that the speaker was familiar with one individual but unfamiliar with the other. Even 2-year-olds successfully identified Jessie as the individual with whom the speaker was familiar. Experiment 2 examined whether children appreciate this principle at a general level, as do adults, or whether this knowledge may be specific to certain word-learning situations. To test this, forty-eight 3- to 5-year-old children were given the converse of the task in Experiment 1—they were asked to determine the individual with whom the speaker was familiar based on the speaker’s knowledge of an individual’s proper name. Only 5-year-olds reliably succeeded at this task, suggesting that a general understanding of the familiarity principle is a relatively late developmental accomplishment.     

Young Children''s Disambiguation of Object Name Reference

Children show a disambiguation effect--a tendency to select unfamiliar rather than familiar things as the referents of new names. In previous studies, this effect has been reversed in young 2-year-olds, but not older children, by preexposing the unfamiliar objects, suggesting that attraction to novelty controls 2-years-olds' choices of referents for new names, but a mutual exclusivity and/or lexical gap-filling principle determines preschoolers' selections. Both the disambiguation effect and its reversal by preexposure were replicated in the present study; however, 24-month-olds' rate of selecting unfamiliar over familiar kinds was less when they were simply asked to choose between the items than when they were asked to identify the referents of unfamiliar names. Thus, some young children may have both an attraction to novel tokens and a tendency to honor an abstract lexical principle. Referent selections were also affected by object typicality and word similarity. Correlations between the tendency to acknowledge a new name's unfamiliarity and to treat it like a similar-sounding familiar name suggested that youngsters' phonological matching skills affect their interpretation of new names. Also, 4-year-olds who most often mapped distinctive-sounding new names to unfamiliar kinds tended to admit their unfamiliarity with these names most frequently, suggesting that children's increasing awareness of their own knowledge begins to affect their lexical processing during the preschool years.     

Effects of repeated defeat by a dominant conspecific on subsequent pain sensitivity,open-field activity,and escape learning

Male rats were tested as intruders for 25 consecutive days in colonies that had either aggressive (i.e., alpha) or nonaggressive conspecific residents. Alpha-defeated intruders, in contrast to nondefeated rats, showed more defensive behavior, less gain in body weight, and received more bites during the course of these sessions. Tail-flick tests, using a heat source, revealed that both groups of intruders showed comparable sensitivity/reactivity to pain, and there was no evidence of analgesia as a function of resident encounters. Immediately after the last intruder session, all subjects were tested for exploratory activity in an open-field apparatus with the odors (i.e., soiled bedding) from the alpha colonies present. Defeated intruders showed significantly less locomotion, in terms of the number of grid crossings, than nondefeated rats. Twenty-four hours later, randomly selected subgroups of defeated and nondefeated subjects were briefly exposed, without being defeated, to aggressive colonies, and all rats were then retested for activity with alpha odors present. Previously defeated intruders were again less active, and the colony-exposure treatment suppressed the activity of defeated, but not nondefeated, subjects. Finally, 24 h after another resident-intruder session, both groups of intruders showed comparable FR 1 escape performance in a shuttlebox with alpha odors present, but the defeated rats failed to learn a subsequent FR 2 escape task. The findings of this experiment are discussed in terms of the concept of “learned helplessness,” the effects of ethological stressors, and the authors’ stress-coping-fear-defense (SCFD) theory.     

Diet sampling by wild Norway rats offered several unfamiliar foods

The present experiment was undertaken to examine directly the diet sampling behavior of wild Norway rats (Rattus norvegicus) faced with a choice among familiar and unfamiliar foods. First-generation, laboratory-reared wild Norway rats ate from four food cups. Three of the food cups were in unfamiliar locations and contained unfamiliar foods. The remaining food cup was in a familiar location and contained a familiar food. Subjects in a control group were offered the familiar food in all four locations. We found (1) that subjects in experimental and control conditions took equal amounts of time to first visit food cups in unfamiliar locations, (2) that subjects in the experimental condition (those with access to unfamiliar foods) ate at unfamiliar locations at a slower rate than did subjects in the control condition (those with access only to familiar food), (3) that subjects in the experimental condition were no more likely than subjects in the control condition to eat at one unfamiliar location at a time, and (4) that following a bout of eating at an unfamiliar food cup, subjects in the experimental condition waited no longer than subjects in the control condition before eating from a different unfamiliar food cup. We interpreted these data as indicating that although wild Norway rats are hesitant to eat unfamiliar foods, once they begin to eat such foods, they do not sample among them so as to facilitate identification of any toxin present.     

Anxious solitude across contexts: girls' interactions with familiar and unfamiliar peers

Cross-situational continuity and change in anxious solitary girls' behavior and peer relations were examined in interactions with familiar versus unfamiliar playmates. Fourth-grade girls (N=209, M age=9.77 years, half African American, half European American) were identified as anxious solitary or behaviorally normative using observed and teacher-reported behavior among classmates. Subsequently, girls participated in 1-hr play groups containing 5 same-race familiar or unfamiliar girls for 5 consecutive days. Results support both cross-situational continuity and change in anxious solitary girls' behavior and peer relations. Although anxious solitary girls exhibited difficulty interacting with both familiar and unfamiliar playmates relative to behaviorally normative girls, elements of their behavior improved in unfamiliar play groups, a context in which they received less peer mistreatment.