bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of the surface of simple geometric models upon children's drawings
Authors: Derȩgowski J. B. , Dziurawiec S.
Published: July 2011

It is generally assumed that a child drawing a geometric model will do so by depicting its edges, the surface of the model merely defining these edges as it undergoes rapid change, whilst also obscuring some other edges and thus making depiction difficult. The present study, in which drawings of three groups of about 100 children drawn from grades 3, 5 and 7 of Scottish urban schools were used, suggests that the relationship between perception of the crucial edges and the surfaces is more complex. It shows that children draw lamellar models differently from geometrically congruent wire models (which have no surfaces) and suggests that the changes in drawing with age and/or schooling are at least in part due to changes of perception and surface/edge relationships.
Skilled and less skilled comprehenders: French children's processing of anaphoric devices in written texts
Authors: Ehrlich Marie‐France , Remond Martine
Published: July 2011

This experiment investigated the processing of anaphoric devices in French 9‐year‐old skilled and less skilled comprehenders, matched in decoding and vocabulary skills. It was designed to study whether the differences observed between skilled and less skilled comprehenders could be attributed to a specific deficit in processing anaphors or to a more basic deficit. Children were asked to identify the antecedents of different anaphors while reading two long stories. Processing complexity was manipulated by varying three properties of anaphors: type (personal pronoun or general noun), syntactic function (subject or object) and distance in relation to antecedents (near or far). In both texts less skilled comprehenders performed less well than skilled ones. Type and syntactic function affected anaphor resolution: pronouns were more difficult to resolve than general nouns, objects more difficult than subjects. In one text far antecedents were more difficult to find than near antecedents, but the opposite effect was observed in the other text. The interactions between comprehension skill and the three manipulated factors suggest that a specific deficit in the processing of anaphors contributes to the lower performance of less skilled comprehenders, who had particular difficulties with object pronouns. The analysis of incorrect responses confirmed the weight of such specific difficulties. In conclusion, the interdependence between a specific deficit in the processing of anaphors and other deficits is discussed.
Changes in negative emotionality in infancy: The role of mother's attachment concerns
Authors: Scher Anat , Mayseless Ofra
Published: July 2011

In a longitudinal study the contribution of mothers' attachment concerns to the infant negative emotionality was examined. Ninety‐three mothers described their child's temperament at 3 and 9 months. The results revealed that increased negative emotionality at 9 months was related not only to high levels of fussiness at 3 months but also to mothers' concerns and worries about their personal relationships. It was found that infants of mothers who tended to be avoidant in their close adult relationships showed increased levels of negative emotionality during the latter part of the first year. Further, infants of mothers who appeared secure (not avoidant) in their adult close relationships showed decreased levels of negative emotionality. The findings of the present study give some support to a directional link between caregivers' characteristics and the regulation of negative emotionality in infancy.
Mothers' and fathers' scaffolding of their 2‐year‐olds during problem‐solving and literacy interactions
Authors: Conner David B. , Knight Danica K. , Cross David R.
Published: July 2011

Building upon Wood & Middleton's (1975) concept of parental scaffolding, the influence of parent—child interactions on children's competence within several tasks was investigated. Thirty‐two 2‐year‐old children visited our lab twice, once with their mothers and once with their fathers. During each session dyads participated in problem‐solving and literacy tasks, followed by independent child performance tasks. Although subtle differences were found between mothers' and fathers' contingent behaviours displayed during the interactions, at a global level, parents were equally effective in their ability to scaffold their children's emerging skills. Specifically, parental scaffolding behaviours were associated with children's success measured both during the interaction and independently (i.e. following the interactions). These results have implications for the interpretation of research comparing mothers and fathers, and lend support to the claim that scaffolding can be an effective instructional strategy.
Preschoolers' understanding of others' mental attitudes towards pretend happenings
Authors: Hickling Anne K. , Wellman Henry M. , Gottfried Gail M.
Published: July 2011

One question about early understanding of the mind concerns when young children realize that pretence involves persons' thoughts or mental attitudes. Two experiments explored this understanding in 3‐ and 4‐year‐olds. In focal pretence tasks, children judged the thoughts of an absent puppet (Study 1) or person (Study 2) regarding a transformation of an initial pretence stipulation. For comparison, children completed a benchmark false belief task (Study 1) or a modified trick task (Study 2). Overall, children responded accurately when assessing another person's pretence‐directed thoughts but less so when reasoning about someone else's beliefs. By age 3 years, children appropriately assessed others' thoughts towards pretend happenings, demonstrating that they view pretence as both mentalistic and subjective.
Explanations of unusual events: Phenomenalistic causal judgments in children and adults
Authors: Subbotsky Eugene
Published: July 2011

Children 6 and 9 years old and adults were shown unusual events (transformations of a postage stamp in an empty box) that were accompanied by three experimental actions (putting a postage stamp into an envelope, cutting a piece of paper in half and transforming a plasticine ball into a sausage) which apparently could not have any causal relation to the unusual event. Having no plausible explanation for the unusual event in Expt 1, children of both age groups (but not adults) were inclined to name one of the experimenter's manipulations (the one that resembled the unusual event by an action but not by an object) as a cause of the unusual event, thus producing phenomenalistic causality judgments. In Expt 2 children tended to interpret a postage stamp transformation caused without an obvious physical contact (but not a similar phenomenon in which a remote control car was moved from a distance) as a magical event. The children were equally inclined to produce a phenomenalistic causal judgment in the conditions in which the accompanying actions were made by an adult experimenter or by their peers (Expt 3). In Expts 4 and 5 adult participants in their overt behaviour (but not in their verbal judgments) revealed a tendency to succumb to phenomenalistic causal thinking under the increased cost of disregarding the possibility of a phenomenalistic causal connection. The data are interpreted in the light of the ‘coexistence’ model of the development of fundamental structures of mind according to which early forms of reasoning retain their power in the mind of an educated adult.
Propulsion: A behavioural expression of masculinity
Authors: Benenson Joyce F. , Liroff Erica R. , Pascal Stacy J. , Cioppa Guiseppe Della
Published: July 2011

Based upon studies of children's sex‐typed behaviours, it is theorized that a forceful, forward motor behaviour, or propulsion, is an integral component of several masculine sex‐typed behaviours. To test the relation between propulsion and masculinity, a game of tag was designed to elicit propulsion from 3‐ to 5‐year‐old children. In addition, in Study 1, teachers rated children's degree of masculinity and, in Study 2, the masculinity of children's toy preferences was assessed. Results showed a significant relation between propulsion and measures of masculinity. Findings are discussed in terms of the importance of considering motor behaviour in studies of sex typing.
Reaction time measures of speed of processing: Speed of response selection increases with age but speed of stimulus categorization does not
Authors: Anderson Mike , Nettelbeck Ted , Barlow Jill
Published: July 2011

We report an experiment that investigates the relationship between speed of information processing and development. The goal of the experiment was to compare developmental changes at two stages of processing—response selection and stimulus categorization. The experiment compared developmental change on three kinds of reaction time task. The first was a standard Jensen (1982) procedure which separates the decision and motor components of reaction time, the second was a modification of this procedure suggested by Smith & Carew (1987) to control for possible anticipatory strategies, and the third was a more traditional reaction time task where each stimulus is paired with a unique response (lights‐to‐keys). Age changes in speed of information processing were found for the lights‐to‐keys task but not for either of the Jensen tasks. We argue that this is because the lights‐to‐keys task taps response selection factors that change with age and that are orthogonal to differences in speed of stimulus categorization indexed by the standard Jensen task. If the latter is taken as the purer index of speed of processing then we conclude that speed of processing does not change with age.
The development of prehension in infants: Halverson revisited
Authors: Butterworth G. , Verweij E. , Hopkins B.
Published: July 2011

The development of prehension was studied in babies aged between 6 and 20 months in a partial replication of the classic study by Halverson (1931). In our study the objects to be grasped were spheres and cubes carefully graded to allow comparisons of grips with object shape and size controlled. The trend noted by Halverson, for power grips to decrease and precision grips to increase, was replicated so that by the second year precision grasping is the dominant mode of prehension. However, the transition to precision grasping appears to occur by selection from a developmentally prior mixture of power and precision grips. In comparing spheres and cubes object size was the most important factor influencing grip selection but object shape also had a lesser influence. Object size may have acted as a scaling factor for grip selection. The findings are discussed in relation to a selectionist approach to the development of prehension.
Components of person perception: An investigation with autistic, non‐autistic retarded and typically developing children and adolescents
Authors: Moore Derek G. , Hobson R. Peter , Lee Anthony
Published: July 2011

This study is an attempt to analyse whether there may be separable components to the human ability to perceive people aspeople who engage in actions and who have attitudes. We adopted the approach of developmental psychopathology. Matched groups of typically developing, autistic and non‐autistic retarded (MR) children and adolescents were tested for the ability to recognize videotaped representations of ‘a person’, a person's actions and a person's emotion‐related attitudes and allied subjective states as manifest in moving point‐light images of people. Autistic and non‐autistic MR participants did not differ in the ability to recognize that a person was represented in very brief exposures of a walking point‐light display; autistic, MR and typically developing participants were equally able to recognize a person's actions. Non‐autistic MR and typically developing participants were also similar in their propensity to notice a person's attitudes vis‐à‐vis the person's actions, and in their abilities to recognize actions and attitudes when specifically asked to do so. By comparison, however, autistic participants were specifically impaired in attending to and discriminating people's attitudes and states. The results are discussed in relation to current debates on the nature of basic person‐perceptual abilities that may underpin typically developing children's understanding of persons with minds ('theory of mind'). We also consider their relevance for controversies over the primary deficits in autism.
Language acquisition and the compensation of visual deficit: New comparative data on a controversial topic
Authors: Pérez‐Pereira Miguel , Castro J.
Published: July 2011

Some researchers have maintained that blind children show an important delay in their language development, and that blind children's language is ‘aberrant’ or special in certain aspects, including the use of personal pronouns, repetitions, formulas, and unanalysed speech. Consequently, it has been claimed that blind children are less active processors of language than sighted children, and that they rely on rote learning, which determines some of the characteristic features of their language. Data are presented which run counter to this view. These come from a longitudinal study of a blind child and her sighted twin sister. The study began when the children were 2:5 years old and spanned nearly three years. Mean length of utterances, over‐regularizations, pronoun errors, pragmatic speech functions, and imitations, repetitions and routines (IRR) were analysed. The results clearly show that the language of the blind child is neither delayed, nor aberrant. Evidence is shown that IRR form part of a mechanism of language analysis, which is specially used by the blind girl, who seems to manifest a Gestalt style of language learning.
Children's and adults' everyday talk about surprise
Authors: Bartsch Karen , Estes David
Published: July 2011

Everyday uses of the term ‘surprise’ were examined in order to describe children's early experience with the term and explore links to children's developing conception of surprise. Data obtained from CHILDES (MacWhinney & Snow, 1990) included 123 uses of ‘surprise’ by children (N = 10, aged 2:0–5:5) and 118 by adults talking to children. Each use was coded for reference to expectation (expected, unexpected, or indeterminate) and affect (positive, negative, or indeterminate), as well as on other aspects of content (agreements = 91–100 per cent). From ages 2 to 5, children increasingly referred to unexpected events and decreasingly to positive affect or happy events, relative to other sorts of references; adults' speech showed little change on those dimensions. Implications for an account of conceptual development are discussed.
Relations between task structure and developmental changes in children's use of spatial clustering strategies
Authors: Plumert Jodie M. , Strahan David
Published: July 2011

Two experiments investigated how the supportiveness of the task influences children's use of spatial clustering strategies. Experiment 1 documented developmental differences in 6‐, 8‐ and 10‐year‐olds' use of spatial clustering in a tour‐planning and in a free recall task. Children hid objects in a dollhouse and later recalled the objects or planned a tour of the objects. Ten‐year‐olds, but not 6‐ and 8‐year‐olds, who planned the tour showed more spatial clustering than did their counterparts who performed the standard free recall task. Experiment 2 investigated transfer of spatial clustering strategies from the more supportive tour‐planning task to the free recall task. Eight‐ and 10‐year‐olds again hid objects in the dollhouse and then performed a tour‐planning or a free recall task. Immediately afterward, all children performed a free recall of the objects. Ten‐year‐olds, but not 8‐year‐olds, who performed the tour‐planning task first showed significantly more spatial clustering in their subsequent free recall than did their counterparts who performed the free recall task first. Discussion focuses on factors that lead to developmental changes in children's ability to apply their spatial clustering skills to different tasks.
Children's judgments of emotions portrayed in museum art
Authors: Callaghan Tara C.
Published: July 2011

Children's sensitivity to the emotions portrayed in museum art was explored in two studies. In Study 1, children between the ages of 5 and 11 years and adults matched postcards of art works to photographs of an actress portraying one of four emotions (happy, sad, excited and calm). There was an increase over age in the consistency between children's judgments and artist norms. At all ages the level of consistency with the artist norms was well above chance. In Study 2 participants chose from the entire set of 16 art works the ones that were the ‘best’ and ‘second best’ examples of each of the four emotions, and told why they made those choices. There was an increase in the consistency of judgments over age, and higher than chance levels of consistency at all ages. In both studies we found that at all ages paintings portraying outwardly directed emotions (happy, excited) were associated with less consistency in judgments, whereas paintings showing inwardly directed emotions (sad, calm) were associated with greater levels of consistency. There was also high agreement across studies when choices were inconsistent with the original categories. For happy art works, the most likely alternate choice was excited or calm for children and excited for adults. For sad the most likely alternative was calm at all ages. For calm paintings there were very few alternative choices. For excited, the most likely alternative was happy at all ages. The justifications for choices given by children supported Parsons' (1987) developmental model of aesthetic understanding. It was concluded that even very young children are sensitive to the emotions portrayed in museum art and can provide reasonable justifications for their choices.
Emotional instability as an indicator of strictly timed infantile developmental transitions
Authors: de Weerth C. , van Geert P.
Published: July 2011

There are indications that periods of disorganization/instability/regression accompany developmental transitions in early infancy. The goal of the present study was to validate a pattern of 10 strictly timed periods of emotional instability found through maternal reports by van de Rijt‐Plooij & Plooij (1992a), by means of ethological observations. A longitudinal study was carried out on four mother‐infant pairs which were followed up weekly during a period of 15 months. The results failed to support the 10‐period pattern. Possible explanations for these findings are presented, together with a discussion about methodological aspects of the data analysis., 20 October 1995, 14 November 1996
Developmental changes in action: Theoretical and methodological issus
Authors: Wimmers R. H. , Beek P. J. , Savelsbergh G.J.P. , Hopkins B.
Published: July 2011

A tutorial is provided of how the concepts and methods of non‐linear dynamical systems theory and, in particular, catastrophe theory can be of help in understanding the development of action. From this theoretical perspective, development is viewed as a complex, time‐evolving process in which new behaviours (e.g. reaching, walking, speech) are the product of self‐organization. Qualitative changes in behaviour are interpreted—ex hypothesi—as discontinuous non‐equilibrium phase transitions or catastrophes. In the context of the study of the development of prehension, it is illustrated how this interpretation can be investigated empirically by testing if specific transition criteria are satisfied. Once the presence of such criteria has been confirmed for the emergence of a particular behaviour, the next step is to determine if a catastrophe model can be found that applies to the data. Preliminary evidence is provided that the developmental change in prehension during the first six months of life is best described as a cusp catastrophe.
Changing focus on the representational mind: Deaf, autistic and normal children's concepts of false photos, false drawings and false beliefs
Authors: Peterson Candida C. , Siegal Michael
Published: July 2011

We report two experiments designed to explore further the parallels noted previously between deaf and autistic children's mastery of a theory of mind and to compare their emerging concepts of false belief with their understanding of false representation in the photographic and artistic domains. In Expt 1, standard false‐belief and false‐photograph tasks were given to 21 high functioning autistic children, 35 normal preschoolers and 30 signing deaf children from hearing families. The children with deafness performed similarly to those with autism. The vast majority of both groups passed the false‐photograph test, but less than half displayed a correspondingly accurate understanding of false belief. Normal 4‐year‐olds did equally well on photo and belief tasks, significantly surpassing deaf and autistic children's performance on the latter. However, in contrast to some previous research, the normal 3‐year‐olds also found the false‐photograph task easier than the false‐belief task in Expt 1. Experiment 2 was therefore designed to provide a more tightly controlled comparison of the relative difficulty of concepts of false representation in three modalities— photographic, mental and pictorial—using identical procedures in each modality so as to equate the tasks' conceptual, syntactic and pragmatic demands. A total of 24 deaf children, 21 autistic children and 47 normal preschoolers participated in Expt 2. The results replicated those of Expt 1 by showing no difference between deaf and autistic children, both of whom displayed a poorer understanding of false beliefs than of false photographs. But the normal 3‐year‐olds in Expt 2 did no better on the photo than the belief tasks, suggesting procedural factors as an explanation for this age group's Expt 1 performance. The absence of significant differences among the diagnostic groups on the false‐drawing task highlighted the need for further research into the development of representational concepts in the artistic domain. Consideration was given to how impoverished early conversational experience and selective deprivation of talk about intangible mental states might influence deaf and autistic children's development of a theory of mind.
English children's geo‐political knowledge of Europe
Authors: Rutland Adam
Published: July 2011

Variations in English children's geo‐political knowledge of Europe associated with age, sex, social class, travel experience and parental attitudes were studied. The participants were 172 children aged 6–16 years old, and their knowledge was assessed using four different methods, including two map interpretation tasks, a naming task and verbal questioning. These methods proved a reliable measure of children's geo‐political knowledge of Europe. The results showed that the children's knowledge was related primarily to age and to a lesser extent, independently, to social class background and travel experience. In addition, parental attitudes towards Europe had no direct effect on the children's knowledge. These results suggest that future research is needed into the precise influences that cause age and social class differences in children's geo‐political knowledge of Europe.
Overgeneralizations of number inflections in the learning of written French: The case of noun and verb
Authors: Totereau C. , Barrouillet P. , Fayol M.
Published: July 2011

The present article reports a study of overgeneralizations occurring in the learning of written French morphology in which the markers of plurality for nouns (‐s) and verbs (‐nt) are mostly not audible. Because of this inaudibility, many nouns and verbs that are pronounced alike are spelled differently. French writers are thus confronted with interference in such cases: two (‐s vs. ‐nt) graphemic configurations are possible for the same phonological configuration, which sometimes leads to errors in adults. The experiment shows that, at a certain point during their learning of written morphology, children make the same type of error: they (over) generalize the number marker for nouns (‐s) to verbs and the number marker for verbs (‐nt) to nouns, before achieving complete mastery of plural morphology. Moreover, children would store and use instances of associations between stems and morphemes when an item can, depending on the context, be either a noun or a verb. In this case, the occurrence frequencies of instances would determine the probability and the intensity of plural morpheme activation, leading to the appearance of homophone effects which have already been described in adults: nouns frequently encountered as verbs are often inflected with (‐nt), whereas only verbs frequently used as nouns are inflected with (‐s). These results are discussed within the framework of an activation model involving both rules and associations
The effects of rerepresentation on future performance
Authors: Kentgen Lisa , Allen Rhianon , Kose Gary , Fong Regan
Published: July 2011

This study examined Karmiloff‐Smith's (1984) model of the development of higher levels of awareness. We extended her model and examined the effects of externally induced representations of a successfully completed action on future performance. Fifty‐three children, between the ages of 6 and 8 years, built a bridge to a mountain. After completion, one group drew and verbalized their bridge‐building process, another group only drew, a third group only verbalized and a control group did not rerepresent. The children then built another bridge. Compared to the no‐representation group, children who represented in two modalities tended to increase their spontaneous strategy changes during the second building. The verbal‐only group showed increased spontaneous strategy change relative to no‐representation controls. The draw‐only group decreased this meta‐procedural activity over time compared to the multiple representation group. The bridge constructions were more complex in the second building for the multiple representation group. This study gives support to the possibility of externally stimulating higher levels of awareness in children. Task process change may be understood as a precursor for more substantial change. This study suggests that multiple representations may lead to the greatest flexibility in future performance, and that mode of representation influences meta‐procedural activity.
Children's rule discrimination within the context of the school
Authors: Buchanan‐Barrow Eithne , Barrett Martyn
Published: July 2011

Following Turiel's (1983) proposal of two distinct conceptual domains of social thinking, the moral and the social‐conventional, research has revealed that children acquire competent rule‐differentiation abilities at a very early age within the family context (Smetana & Braeges, 1990; Smetana, Schlagman & Adams, 1993). This study investigated children's rule‐understanding within the context of the school by examining children's judgements of a range of infringements by schoolchildren, involving both moral and social‐conventional rules. Children, aged 5–11 years, from four primary schools, assessed six hypothetical rule‐breaking scenarios, two moral and four socio‐conventional, according to the traditional criteria. However, in order to probe the children's differentiation skills beyond a simple dichotomy between moral and socio‐conventional, the four socio‐conventional infringements were sub‐divided between two rules with discernible purpose and two rules where the function was unclear or more arbitrary. There were two main findings: (1) the children displayed competent and complex rule‐discrimination abilities with minimal age differences, not only differentiating between the moral and socio‐conventional but also perceiving significant differences between the two types of socio‐conventional rules; (2) the children also revealed a clear sense of the authority competencies of head teachers and teachers, again largely unaffected by age. However, despite these overall levels of rule understanding, there were some individual differences in the moral thinking of some of the younger children, possibly as a consequence of aspects of the school system.
Causal reasoning about pairs of relations and analogical reasoning in young children
Authors: Goswami Usha , Leevers Hilary , Pressley Sarah , Wheelwright Sally
Published: July 2011

Two experiments were conducted to investigate how children aged 3–6 years performed in classical analogy problems based on single and double relations. The number of relations in an analogy is seen as an important competence factor in Halford's theory of analogical development (1987, 1992, 1993). In contrast, other authors have proposed that the critical factor in analogical success is relational familiarity (e.g. Brown, 1989; Chen & Daehler, 1989; Gentner, 1989; Goswami, 1992, 1996; Inagaki & Hatano, 1987; Vosniadou, 1989). In our experiments, we gave children analogies to solve based on pairs of causal relations (such as cutting and wetting), and also measured their performance when similar analogies were based on single relations (such as cutting or wetting). The ability to process the relations or relation used in each analogy was also measured in control conditions. The results suggested that the number of relations in an analogy does not overload available capacity. Clear “learning‐to‐learn” effects were found in both studies, showing that children's analogical performance can improve significantly over the course of an experiment, even when relational familiarity is present.
Two functional orientations of self‐exploration in infancy
Authors: Rochat Philippe , Morgan Rachel
Published: July 2011

Twenty 3‐ and 5‐month‐old infants were presented with either a congruent or incongruent (left/right reversal) on‐line views of their own legs on a large TV monitor in two different experimental conditions. In one (no‐object) condition, infants viewed their legs which produced a sound each time they moved them. In another (object) condition, they viewed their legs plus an object target which produced a sound each time it was kicked. Results indicate that from 3 months of age infants tend to reverse their pattern of relative visual attention and leg movement depending on the condition. Confirming previous findings, at both ages infants looked significantly longer and were more active while looking at the incongruent view of their own legs in the no‐object condition. In contrast, infants looked significantly longer and were more active while looking at the congruent view of their own legs in the object condition. These observations are interpreted as evidence that early in the first year of life, infants express a sense of their own body as a perceptually organized entity which they monitor and control as either an object of exploration or an agent of action in the environment.
Young children's ability to use maps and models to find ways in novel spaces
Authors: Bremner J. Gavin , Andreasen Gillian
Published: July 2011

Previous research has demonstrated that even quite young children can use a map to find a location in space or follow a simple route. The present research investigates the effectiveness of different forms of representations of space as aids to route following by 4.5‐ and 5‐year‐old children. If the alignment between axes of map and space was broken by introduction of a 90 degree turn in the path of the route, performance declined markedly for both age groups. However, this drop in performance was not evident if children were provided with a linear map or model to aid them through the non‐linear maze. In a five‐choice linear maze, 5‐year‐olds performed better using a model than a map, and performance using the map was better following performance with the model. Thus it appears that whereas the spatial arrangement of the route need not be precisely reproduced in the representation, the more accurate match between space and its representation provided by a three‐dimensional model of space still acts as a better aid to route finding. These apparently conflicting findings are in keeping with the notion that young children represent routes in terms of a sequence of turns at choice points without particular attention to the spatial arrangement of different parts of the route. Thus, although accurate representation of the spatial layout of choice points is unnecessary, at the same time a three‐dimensional representation enhances performance by providing a better representation of the features of each choice point.
Perception and conceptualization of intentionality in children
Authors: Thommen E. , Dumas A. , Erskine J. , Reymond J.
Published: July 2011

In the present study, comprising four experiments, we evaluated the development of the child's ability to theorize about intentionality. Children (N = 176) and adults (N = 28) were shown short films about two small moving geometrical forms. The stimuli were replications of those created by Michotte (1946) and Kanizsa & Vicario (1969). The participants' descriptions and explanations were examined. The causes of movement were divided into two categories: causality and intentionality. Our prediction was that the distinction between these two categories would be mastered at an early age, but only at a much later age would participants theorize about them. Results show three stages to this development.
Temporal characteristics of vesicular fusion in astrocytes: examination of synaptobrevin 2‐laden vesicles at single vesicle resolution
Authors: Malarkey Erik B. , Parpura Vladimir
Published: July 2011

Non‐technical summary  Astrocytes have been shown to release transmitters by vesicle fusion, in a manner similar to that of neuronal exocytosis. The details of this process in astrocytes are not well understood, so we used a fluorescently labelled vesicle protein, synapto‐pHluorin (spH), to track how these fusions occurred. When astrocytes were mechanically stimulated we saw a slow burst of fusions, while other stimuli caused a relatively even sustained rate of fusion. We observed two distinct types of events, transient and full fusions, the proportion of which was stimulus dependent. Similarly, stability of the vesicle fusion pore with the plasma membrane varied with the stimulus. We describe the effects on fusion events resulting from expressing variants of exocytotic proteins, synaptotagmin 1 and SNAP25B. Studying the characteristics of astrocytic exocytosis will aid in the general understanding of this process and also events at the tripartite synapse, both in health and disease.
Intracellular recordings of subnucleus reticularis dorsalis neurones revealed novel electrophysiological properties and windup mechanisms
Authors: Soto Cristina , Canedo Antonio
Published: July 2011

Non‐technical summary  The electrophysiological properties of subnucleus reticularis dorsalis (SRD) neurones were intracellularly studied. The work describes three different classes of cells differentiated by the absence (class I) or presence (classes II and III) of a fast postspike hyperpolarisation followed by depolarising sags and activation of low threshold calcium channels (class II) or type A potassium channels (class III); properties that entitle the different SRD cells to intrinsically regulate their temporal firing. All three classes showed subthreshold oscillatory activity leading to cumulative excitation (windup) in response to low frequency C‐fibre afferent input as well as to low frequency injection of depolarising currents, thus allowing SRD cells to generate windup intrinsically. The three neuronal classes sent collateral branches to the nucleus reticularis gigantocellularis (NRGc) and the spinal cord which would provide simultaneous regulation of pain‐related motor responses through the NRGc, and ascending nociceptive information via the SRD‐descending fibres ending at the spinal dorsal horn.
n–3 polyunsaturated fatty acids in the maternal diet modify the postnatal development of nervous regulation of intestinal permeability in piglets
Authors: De Quelen F. , Chevalier J. , Rolli‐Derkinderen M. , Mourot J. , Neunlist M. , Boudry G.
Published: July 2011

Non‐technical summary  In this study, we demonstrated that supplementation of the maternal diet with a particular fatty acid, 18:3 n‐3, the precursor of the n‐3 fatty acid family, modified intestinal permeability, probably via diet‐induced neuroplastic changes of the enteric nervous system of newborn piglets. These findings suggest that feeding fatty acids of the n‐3 family during pregnancy and lactation impact newborn intestinal barrier function. However, the beneficial versus harmful consequences of this increased intestinal permeability remain to be elucidated.
Mechanism of auxiliary β‐subunit‐mediated membrane targeting of L‐type (CaV1.2) channels
Authors: Fang Kun , Colecraft Henry M.
Published: July 2011

Non‐technical summary  Voltage‐dependent L‐type calcium (CaV1.2) channels are critical gateways for Ca2+ entry into excitable cells such as heart myocytes and neurons. This Ca2+ signal controls many essential physiological responses including triggering the heartbeat and regulating gene expression in nerve cells. CaV1.2 channels are multi‐subunit proteins, comprising α1C, β, and α2δ subunits, and must target to the cell surface to function. Association of a pore‐forming α1C and cytosolic β is necessary for targeting CaV1.2 channels to the cell surface through poorly understood mechanisms. Here, using a chimeric channel strategy, we provide data that suggest β binding to the α1C intracellular I–II loop causes a global rearrangement of intracellular domains, shifting a balance of power between export signals on the I–II loop and retention signals elsewhere on the channel. The results provide novel insights into the mechanism of a protein–protein interaction that is vital for forming functional CaV1.2 channels.
Modeling of Overpotentials in an Anode-Supported Planar SOFC Using a Detailed Simulation Model
Authors: Severson Henning , Assadi Mohsen
Published: July 2011

In this paper results from a parameter study of an anode-supported solid oxide fuel cell (SOFC) are presented. The effects on performance, current-voltage (I-V) characteristics, polarization voltages, and diffusion coefficients are modeled for different temperatures, electrolyte thickness, porosities, and pore sizes. The analysis is carried out for a planar SOFC with YSZ electrolyte, LSM cathode, and Ni-YSZ anode, with thicknesses 20, 50, and 500 μm respectively, and with co-flow geometry. The predicted performance is validated with measured data found in the literature with good agreement. Standard equations for binary and Knudsen diffusion in porous media, concentration overpotentials, and Ohm’s law are used in the modeling. Activation overpotential is predicted by use of temperature dependent linear equations at both the anode and cathode sides. It is found that both ohmic and activation overpotentials decrease considerably with increasing temperature, while concentration overpotentials increase moderately with increasing temperature. The effect on concentration overpotentials can be explained by the reduced gas density with increased temperature, despite the increasing diffusion coefficient. Furthermore, it was found that increasing the pore sizes decreases concentration overpotentials. At low pore size the Knudsen diffusion coefficient is a bottleneck for the diffusion coefficient since it is much lower than the binary diffusion coefficient. It has been demonstrated that by increasing the pore size the Knudsen diffusion coefficient is improved. The effect of porosity has much in common with the effect of pore size; increasing porosity leads to decreased concentration overpotential due to the improved diffusion coefficient. As a natural phenomenon for anode-supported cells, most of the concentration overpotentials take place at the anode side due to its thick structure despite the high diffusion coefficient of hydrogen. It must be underlined that in this study the effect of different porosities and pore sizes is modeled at the anode and cathode substrates only without taking into account the length of the three phase boundary (LTPB) near the electrolyte interface. However, since these microstructural parameters can have an impact on the LTPB, they can also have an impact on the activation overpotentials. This is not considered here and will be taken into account in future work.
Numerical Simulation of Operating Parameters in a Methane Fueled Steam Reforming Reactor
Authors: Park Joonguen , Bae Joongmyeon
Published: July 2011

This paper studies the heat and mass transfer characteristics in a steam reforming reactor using numerical simulation and investigates the operating parameters for effective hydrogen production. Simultaneous analysis of governing equations and chemical reaction equations is carried out in a multiphysical simulation. The major reactions are assumed to be the steam reforming, water-gas shift (WGS), and direct steam reforming reactions. The temperature and species concentrations measured for the experiment are compared with numerical results. After validation of the developed code, numerical work is carried out to study correlations between the performance and operating parameters, which are the wall temperature, the inlet temperature, the steam to carbon ratio (SCR), and the gas hourly space velocity (GHSV). The fuel conversion increases with the high wall temperature due to the increased heat transfer. The inlet temperature may not affect the fuel conversion, if the reformer length is long enough. However, the heat transfer limitation can occur near the inlet when the inlet temperature is over 300 °C. The concentration of carbon monoxide becomes lower with increasing SCR due to the decreased WGS reaction rate. The high GHSV causes the short residence time and it is the reason for the low fuel conversion.
On the Extension of a Fourier Descriptor Based Method for Planar Four-Bar Linkage Synthesis for Generation of Open and Closed Paths
Authors: Wu Jun , Ge Q. J. , Gao Feng , Guo W. Z.
Published: July 2011

In an earlier work, we have presented an efficient method for synthesizing crank-rocker mechanisms that are capable of generating perceptually simple and smooth low harmonic closed curves. In this paper, we seek to extend this approach to the synthesis of planar four-bar linkages for the generation of open curves. Instead of using Fourier transform that requires a function to be defined over the entire period, we combine finite Fourier series in a curve fitting scheme for the approximation of periodic as well as nonperiodic paths. This yields a general method for planar four-bar path generation that is applicable to both closed and open paths.
The Evolution of Static Friction for Elastic-Plastic Spherical Contact in Pre-sliding
Authors: Zolotarevskiy V. , Kligerman Y. , Etsion I.
Published: July 2011

The evolution of static friction and tangential stiffness in presliding of an elastic-plastic sphere in contact with a rigid flat, under full stick contact condition, is analyzed. Empirical dimensionless equations are developed for these parameters.
The Distinct Roles of Two GPCRs, MrgprC11 and PAR2, in Itch and Hyperalgesia
Authors: Liu Qin , Weng Hao-Jui , Patel Kush N. , Tang Zongxiang , Bai Haihua , Steinhoff Martin , Dong Xinzhong
Published: July 2011

Sensory neurons perceive itch and heat-induced pain through two different receptors.
Diphenylpyrazole-Derived Compounds Increase Survival Time of Mice after Prion Infection
Authors: Leidel Fabienne , Eiden Martin , Geissen Markus , Kretzschmar Hans A. , Giese Armin , Hirschberger Thomas , Tavan Paul , Schätzl Hermann M. , Groschup Martin H.
Published: July 2011

Transmissible spongiform encephalopathies (TSEs) represent a group of fatal neurodegenerative disorders that can be transmitted by natural infection or inoculation. TSEs include scrapie in sheep, bovine spongiform encephalopathy (BSE) in cattle, and Creutzfeldt-Jakob disease (CJD) in humans. The emergence of a variant form of CJD (vCJD), which has been associated with BSE, produced strong pressure to search for effective treatments with new drugs. Up to now, however, TSEs have proved incurable, although many efforts have been made both
in vitro
and
in vivo
to search for potent therapeutic and prophylactic compounds. For this purpose, we analyzed a compound library consisting of 10,000 compounds with a cell-based high-throughput screening assay dealing with scrapie-infected scrapie mouse brain and ScN
2
A cells and identified a new class of inhibitors consisting of 3,5-diphenylpyrazole (DPP) derivatives. The most effective DPP derivative showed half-maximal inhibition of PrP
Sc
formation at concentrations (IC
50
) of 0.6 and 1.2 μM, respectively. This compound was subsequently subjected to a number of animal experiments using scrapie-infected wild-type C57BL/6 and transgenic Tga20 mice. The DPP derivative induced a significant increase of incubation time both in therapeutic and prophylactic experiments. The onset of the prion disease was delayed by 37 days after intraperitoneal and 42 days after oral application, respectively. In summary, we demonstrate a high
in vitro
efficiency of DPP derivatives against prion infections that was substantiated
in vivo
for one of these compounds. These results indicate that the novel class of DPP compounds should comprise excellent candidates for future therapeutic studies.
Pharmacokinetics and Virological Efficacy after Switch to Once-Daily Lopinavir-Ritonavir in Treatment-Experienced HIV-1-Infected Children
Authors: Foissac Frantz , Urien Saïk , Hirt Déborah , Frange Pierre , Chaix Marie-Laure , Treluyer Jean-Marc , Blanche Stéphane
Published: July 2011

Lopinavir-ritonavir (LPV/r) is a protease inhibitor that is used twice daily (BID) in the treatment of HIV infection in children. In the context of a single-center observational study, a switch to a once-a-day (QD) LPV/r regimen was proposed for considerations of convenience and to support adherence. The aims of this study were to compare the pharmacokinetics, viral loads, percentages of CD4+T cells, and lipid profiles after switching from a twice-daily to a once-daily regimen of LPV/r in experienced children. For this purpose, LPV concentrations, viral loads, CD4+T cells, and biochemistry data were measured in routine therapeutic drug monitoring procedures in 45 children and adolescents. Thirty-six children were switched to the QD regimen. Nine children on the BID or QD regimen were added for pharmacokinetic-study purposes only. The QD trough concentrations (Ctrough) of lopinavir in plasma were significantly lower than those observed with the BID regimen (P< 0.0001), but the 24-h exposure levels were not significantly lower with the QD than with the BID regimen (P= 0.09). Among 34 evaluable patients who switched from the BID to the QD regimen, the virological efficacy of LPV/r appeared to differ (P< 0.001), with 74% and 57% of viral loads, respectively, being <50 copies/ml (mean follow-up times, 33 and 20 months). Among 22 patients with stable virological control before the switch, 12 experienced either failure or blip (one observation of detectable viral load between two observations of undetectable viral load) after the switch. The change from the BID to the QD regimen did not result in significant differences in CD4+T cell percentages or total cholesterol, high-density lipoprotein (HDL) cholesterol, or triglyceride levels. The switch from the BID to the QD LPV/r regimen led to equivalent exposure and lowerCtroughvalues and resulted in lower levels of virological control in these antiretroviral-experienced children.