bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relation of Child Care to Cognitive and Language Development
Authors: National Institute of Child Health and Human Development Ear
Published: December 2004

Children from 10 sites in the United States were followed from birth to age 3 to determine how experiences in child care relate to cognitive and language development (Ns varied between 595 and 856, depending on the assessment). Multiple assessments of family and child care environments and of cognitive and language competence were collected. Analyses that adjusted for maternal vocabulary score, family income, child gender, observed quality of the home environment, and observed maternal cognitive stimulation indicated that the overall quality of child care, and language stimulation in particular, was consistently but modestly related to cognitive and language outcomes at ages 15, 24, and 36 months. The effect sizes for high (top quartile) versus low (bottom quartile) quality ranged from .18 to .48. After adjusting for child care quality, cumulative experience in center‐based care was associated with better outcomes than was participation in other types of care. The amount of time children spent in care was not related to outcomes. Children in exclusive maternal care did not differ systematically from children in child care. Tests for lagged relations of earlier child care experiences to later performance (adjusting for current child care) showed that language stimulation predicted subsequent cognitive and language performance 9 to 12 months later. Although children in center care at age 3 performed better than children in other types of care, earlier experience in child care homes was associated with better performance at age 3 than was experience in other types of care. The relations of child care variables to outcomes did not vary consistently as a function of family income, quality of home environment, child gender, or ethnic group.
Mastery Motivation and Self‐Evaluative Affect in Toddlers: Longitudinal Relations with Maternal Behavior
Authors: Kelley Sue A. , Brownell Celia A. , Campbell Susan B.
Published: December 2004

This study examined relations between maternal control and evaluative feedback during the second year of life and children's mastery motivation and expressions of self‐evaluative affect a year later. Participants were 75 toddlers (35 girls, 40 boys) and their mothers. Maternal controlling behavior and evaluative feedback were examined while mothers taught their 24‐month‐olds a challenging task. Children's mastery motivation and expressions of self‐evaluative affect were assessed during easy and difficult achievement‐like tasks when they were 36 months old. Maternal evaluative feedback and control style at 24 months predicted children's shame, persistence, and avoidance of mastery activities at 36 months. Specifically, negative maternal evaluations at age two related to children's later shame, especially when feedback was linked to children's actions or products; positive maternal feedback overall, as well as corrective feedback, related to children's later persistence; mothers who engaged in more autonomy‐supporting control with their 2‐year‐olds had children who were less likely to avoid challenging activities at age 3. Children's pride at 36 months was not predicted by mothers' behavior at 24 months.
Coping Efficacy and Psychological Problems of Children of Divorce
Authors: Sandler Irwin N. , Tein Jenn‐Yun , Mehta Paras , Wolchik Sharlene , Ayers Tim
Published: December 2004

Three models of the relations of coping efficacy, coping, and psychological problems of children of divorce were investigated. A structural equation model using cross‐sectional data of 356 nine‐ to twelve‐year‐old children of divorce yielded results that supported coping efficacy as a mediator of the relations between both active coping and avoiding coping and psychological problems. In a prospective longitudinal model with a subsample of 162 of these children, support was found for Time 2 coping efficacy as a mediator of the relations between Time 1 active coping and Time 2 internalizing of problems. Individual growth curve models over four waves also found support for coping efficacy as a mediator of the relations between active coping and psychological problems. No support was found for alternative models of coping as a mediator of the relations between efficacy and symptoms or for coping efficacy as a moderator of the relations between coping and symptoms.
Infant Crying and Adults' Anticipated Caregiving Responses: Acoustic and Contextual Influences
Authors: Wood Rebecca M. , Gustafson Gwen E.
Published: December 2004

These studies assessed adults' latencies to signal that they would respond to infant crying as functions of (1) the degree of infant distress they perceived in the cry, and (2) contextual information relevant to caregiving. In the first study (N= 34), listeners waited longer to respond to cries that they had earlier rated as sounding less distressed than when they heard cries of higher distress. Further, those who had been told that the infant needed sleep waited longer to respond than those without this information. This effect of context information, however, was limited to the latencies; in another study (N= 50), listeners' ratings of distress were not affected. Several acoustic features of the cries correlated with distress ratings and with latencies to signal a caregiving response. Taken together, the results suggest that adults' responses to crying are influenced both by acoustic gradations in the cry itself and by the caregiving context. Ratings of degree of distress manifest in the cry, in other words, may be highly predictive of caregiving behavior but not wholly so. Finally, although certain acoustic variations related to greater perceived distress and speed of response, differences were apparent between infants in the magnitude of these variations. The implication that the general process of cry perception may be calibrated, or fine tuned, to the range of acoustic variation provided by individual infants is discussed.
Vagal Reactivity and Affective Adjustment in Infants during Interaction Challenges
Authors: Bazhenova Olga V. , Plonskaia Oxana , Porges Stephen W.
Published: December 2004

Respiratory sinus arrhythmia (RSA) and heart period were evaluated in 5‐month‐old infants (N= 40) during interaction challenges requiring affective adjustment. The paradigm consisted of four 2‐min experimental conditions designed to elicit behavioral and autonomic responses to object‐mediated (Picture Attention and Toy Attention) and person‐mediated (Still Face and Social Interaction) engagement. The data demonstrated that autonomic state systematically changed during engagement and disengagement with the environment. During the object‐mediated challenge, increases in RSA were uniquely related to positive engagement. During the person‐mediated challenge, there was a more complex integration of autonomic and behavioral responses characterized by concordant increases and decreases in RSA, heart period, positive engagement, negative affect, and motor activity. When participants were partitioned into two groups, based on their RSA response pattern during the person‐mediated challenge, only participants who exhibited a pattern of RSA decrease from Toy Attention to Still Face followed by a rapid recovery during Social Interaction demonstrated regulation of behavioral activity, including concordant recovery from stress. These findings provide additional empirical support for the role of vagal regulation of the heart in the modulation of affective adjustment and engagement behavior.
Trait Understanding or Evaluative Reasoning? An Analysis of Children's Behavioral Predictions
Authors: Alvarez Jeannette M. , Ruble Diane N. , Bolger Niall
Published: December 2004

This study tested the hypothesis that in predicting the future behavior of an actor, older children rely on trait inferences, whereas younger children rely on global, evaluative inferences. Vignettes depicting actors engaging in trait‐relevant behaviors were presented to 5‐ and 6‐year‐olds (N=67) and 9‐ and 10‐year‐olds (N= 71). For each actor, children made predictions of future behavior, evaluated the goodness and badness of the actor, and rated each actor on a relevant trait. A mediational analysis found that the behavioral predictions of older children were mediated solely by trait ratings, whereas those of younger children were mediated by evaluative ratings. Furthermore, unlike older children, younger children made trait‐like predictions only when they made an evaluation of the actor. These results suggest that young children utilize evaluative reasoning when making behavioral predictions, and therefore rely on an inferential process that is distinct from that of older children.
Attention and Memory for Faces and Actions in Infancy: The Salience of Actions over Faces in Dynamic Events
Authors: Bahrick Lorraine E. , Gogate Lakshmi J. , Ruiz Ivonne
Published: December 2004

Discrimination and memory for video films of women performing different activities was investigated in 5.5 month–old infants. In Experiment 1, infants (N= 24) were familiarized to the faces of one of three women performing one of three repetitive activities (blowing bubbles, brushing hair, and brushing teeth). Overall, results indicated discrimination and memory for the actions but not the faces after both a 1–min and a 7–week delay. Memory was demonstrated by a visual preference for the novel actions after the 1–min delay and for the familiar actions after the 7–week delay, replicating prior findings that preferences shift as a function of retention time. Experiment 2 (N= 12) demonstrated discrimination and memory for the faces when infants were presented in static poses at the 1–min delay, but not the 7–week delay. In Experiment 3 (N= 18), discrimination of the actions was replicated, but no discrimination among the objects embedded in the actions (hairbrush, bubble wand, toothbrush) was found. These findings demonstrate the attentional salience of actions over faces in dynamic events to 5.5 month–olds. They highlight the disparity between results generated from moving versus static displays in infancy research and emphasize the importance of using dynamic events as a basis for generalizing about perception and memory for events in the real world.
Developmental Changes in Endogenous Control of Attention: The Role of Target Familiarity on Infants’ Distraction Latency
Authors: Oakes Lisa M. , Kannass Kathleen N. , Shaddy D. Jill
Published: December 2004

This study evaluated the interactive effects of endogenous and exogenous influences on infants’ attention allocation by assessing the role of target familiarity on distraction latency during object exploration. In Experiment 1 (N= 54), infants’ distraction latencies as they investigated both familiar toys (ones they previously had seen in a familiarization procedure) and novel toys (ones they had not seen in the familiarization procedure) were assessed longitudinally at 6.5 and 9 months of age. In Experiment 2 (N= 32), infants’ distraction latencies were assessed at either 6.5 or 10 months as they investigated either familiar or novel targets. In both experiments, older infants, but not younger infants, exhibited longer latencies as they investigated novel toys as compared with their latencies as they investigated familiar toys. These results are discussed in terms of developmental changes in the interactive effects of endogenous and exogenous factors controlling attention allocation.
Perceptual Causality in Children
Authors: Schlottmann Anne , Allen Deborah , Linderoth Carina , Hesketh Sarah
Published: December 2004

Three experiments considered the development of perceptual causality in children from 3 to 9 years of age (N= 176 in total). Adults tend to see cause and effect even in schematic, two–dimensional motion events: Thus, if square A moves toward B, which moves upon contact, they report that A launches B—physical causality. If B moves before contact, adults report that B tries to escape from A—social or psychological causality. A brief pause between movements eliminates such impressions. Even infants in the first year of life are sensitive to causal structure in both contact and no–contact events, but previous research with talking–age children found poor verbal reports. The present experiments used a picture–based forced–choice task to reduce linguistic demands. Observers saw eight different animations involving squares A and B. Events varied in whether or not these agents made contact; whether or not there was a delay at the closest point; and whether they moved rigidly or with a rhythmic, nonrigid “caterpillar” motion. Participants of all ages assigned events with contact to the physical domain and events without contact to the psychological domain. In addition, participants of all ages chose causality more often for events without delay than with delay, but these events became more distinct over the preschool range. The manipulation of agent motion had only minor and inconsistent effects across studies, even though children of all ages considered only the nonrigid motion to be animal–like. These results agree with the view that perceptual causality is available early in development.
Developmental Change in Proactive Interference
Authors: Kail Robert
Published: December 2004

The aim of the present research was to examine age–related change in proactive interference, which refers to impaired recall due to interference from material presented previously. Study 1 was a meta–analysis based on 26 studies that included 82 data sets. The results indicated that proactive interference decreased between 4 and 13 years of age. In Study 2, children from grades 3 through 6 and college students (N= 125) were administered a short–term memory task in which they briefly remembered sets of three words. For all ages, recall was accurate on Trial 1. However, recall became less accurate over Trials 2 through 4, particularly for the younger children in the sample. In addition, structural equation modeling revealed that age–related change in interference was linked to age–related change in speed of information processing. Results are discussed in terms of the nature of age–related change in interference.
Teenage Childbearing, Marital Status, and Depressive Symptoms in Later Life
Authors: Kalil Ariel , Kunz James
Published: December 2004

This study examined the role of prechildbearing characteristics in later–life depressive symptomatology among 990 married and unmarried teenage childbearers. Data from teenagers in the National Longitudinal Survey of Youth (NLSY79) were used to test the relative contribution of age and marital status at first birth to depressive symptomatology measured during young adulthood (ages 27–29). Unmarried teenage childbearers displayed higher levels of depressive symptoms in young adulthood than did women who first give birth as married adults. However, the psychological health of married teenage mothers in later life was as good as that of married adult mothers, whereas unmarried adult mothers and unmarried teenage mothers had similarly poor outcomes. The findings of this study suggest that marital status, rather than age at first birth, may be more relevant for later–life psychological health.
Modeling Emotional, Cognitive, and Behavioral Predictors of Peer Acceptance
Authors: Mostow Allison J. , Izard Carroll E. , Fine Sarah , Trentacosta Christopher J.
Published: December 2004

Integrating principles of differential emotions theory and social information–processing theory, this study examined a model of emotional, cognitive, and behavioral predictors of peer acceptance in a sample of 201 early elementary school–age children (mean age = 7 years, 5 months). A path analytic model showed that social skills mediated the effect of emotion knowledge on both same– and opposite–sex social preference, but social skills and verbal ability were more strongly related to opposite–sex peer acceptance. These findings suggest that adaptive social skills constitute a mechanism through which children express their emotion knowledge and achieve peer acceptance. Results also supported findings of previous studies that showed that emotion knowledge mediated the effect of verbal ability on social skills. Findings from the present study have specific implications for emotion–centered prevention programs that aim to improve children's socioemotional competence and enhance the likelihood of peer acceptance.
Self in Context: Autonomy and Relatedness in Japanese and U.S. Mother–Preschooler Dyads
Authors: Dennis Tracy A. , Cole Pamela M. , Zahn–Waxler Carolyn , Mizuta Ichiro
Published: December 2004

Cultural differences and similarities in socialization during two contrasting laboratory tasks were examined in 30 Japanese mothers and their preschoolers, both temporarily residing in the United States, and 30 U.S. mothers and their preschoolers (age: M= 55.8 months, SD= 4.9). Mother and child actions, speech, emotion, and attention were coded from videotaped observations during a free play task and waiting task. Cross–cultural comparisons showed that U.S. mothers had more conversations that emphasized individual experiences, more often acted as playmates and used joint attention, maintained more physical distance, showed more positive emotions, and made more positive responses to child accomplishment. In contrast, Japanese mothers had more conversations that emphasized shared experiences, showed more divided attention, and maintained social role distinctions. Similar, but fewer cultural differences emerged for children. However, maternal and child characteristics also varied by task context. The results suggested an emphasis on autonomy in U.S. dyads and an emphasis on relatedness in Japanese dyads, but the interactions with task context revealed the coexistence of autonomy and relatedness.
Child Care Quality Matters: How Conclusions May Vary With Context
Authors: Love John M. , Harrison Linda , Sagi‐Schwartz Abraham , Van IJzendoorn Marinus H. , Ross Christine , Ungerer Judy A. , Raikes Helen , Brady‐Smith Christy , Boller Kimberly , Brooks‐Gunn Jeanne , Constantine Jill , Kisker Ellen Eliason , Paulsell Diane , Chazan‐Cohen Rachel
Published: December 2004

Three studies examined associations between early child care and child outcomes among families different from those in the National Institute of Child Health and Human Development (NICHD) Early Child Care Research Network study. Results suggest that quality is an important influence on children's development and may be an important moderator of the amount of time in care. Thus, the generalizability of the NICHD findings may hinge on the context in which those results were obtained. These studies, conducted in three national contexts, with different regulatory climates, ranges of child care quality, and a diversity of family characteristics, suggest a need for more complete estimates of how both quality and quantity of child care may influence a range of young children's developmental outcomes.
Rescuing the Baby From the Bathwater: How Gender and Temperament (May) Influence How Child Care Affects Child Development
Authors: Crockenberg Susan C.
Published: December 2004

Children's temperament and gender, combined with type, quality, and amount of care, likely influence differences in development and should not be overlooked in studies of child care effects. Research is consistent with this view, although definitive studies have not been carried out. Most notable, children's stress responses to full‐time, center‐based child care differ, and these differences are associated with emotional tendencies that may precede their entry into care. Changes in full time, center‐based child care are needed to reduce stress experienced by some children and their providers, using information about what is happening at home and in family day care settings, where typically cortisol‐linked stress does not increase during the day, to guide efforts.
Child Care Research: A Clinical Perspective
Authors: Greenspan Stanley I.
Published: December 2004

Two new studies on day care suggest that young children demonstrate increased aggressive behavior in relationship to time spent in day care and increases in cortisol levels in relationship to full‐time, group‐oriented, out‐of‐home care. These observations can be more fully understood in a clinical context that looks at individual differences in children, families, and child care environments. Factors likely to increase risk include sensory processing and modulation challenges; family stress; and lack of sensitive, nurturing interactions associated with less high‐quality child care. Because 85% to 90% of current day care is not considered to be of high quality, individual families that can provide high‐quality care need to explore carefully their options to see if it is possible to provide direct nurturing care for their infants and young children for at least half of the day.
Less Day Care or Different Day Care?
Authors: Maccoby Eleanor E. , Lewis Catherine C.
Published: December 2004

Commentary is provided on 2 papers published in this issue, which suggest some risks in nonmaternal or out‐of‐home care (National Institute of Child Health and Human Development [NICHD] Early Child Care Research Network, this issue; Watamura, Donzella, Alwin, & Gunnar, this issue). In light of the findings, 2 child care policy options are examined: first, support for in‐home care in the early years; and second, changes in the nature of out‐of‐home care. From ethnographic and experimental research, it is argued that out‐of‐home pre‐elementary care can contribute positively to social development if it emphasizes (a) children's attachment to school and peer group, (b) constructivist rather than didactic learning, (c) intrinsic and internalized motivation, and (4) group structures that support social development.
Children's Expectancies and Perceptions of Adults: Effects on Rapport
Authors: Gurland Suzanne T. , Grolnick Wendy S.
Published: December 2004

Interpersonal expectancy effects are less thoroughly understood in children than in adults, yet they can have practical implications for children's interactions. To understand better children's expectancies, this study extended earlier work to include expectancies of adults, preexisting (i.e., noninduced) expectancies, and joint effects of expectancies and subsequent perceptions. Children (N=81) in Grades 4 through 6 (i.e., 9‐ to 12‐year‐olds) indicated their expectancies of adults who subsequently interacted with them using a style of either autonomy support (AS) or control (CN). After each interaction, children reported on perceived AS and on rapport. Results indicated that children's expectancies and subsequent perceptions interact to predict rapport, adult AS is associated with increased rapport, and the effect of children's expectancies on rapport is only partially mediated by their perceptions.
A Picture Archive Browser
Authors: Willis Philip , Hunter Andrew
Published: December 2004

We describe an implementation of a networked picture browser. The system offers a pictorial interface to pictorial data, relieves the users of thinking about the underlying filing system, provides managerial tools for installing, moving and deleting pictures, offers graded access and picture sharing and supports a number of picture formats, including hierarchical encodings.
Block Iterations in the Complex Plane
Authors: Szyszkowicz Mieczyslaw
Published: December 2004

In this note we propose a new technique for execution of the feedback process z → z2+ c. The presented method is used to discover a family of sets in the complex plane.
A Physically Based Colour Model
Authors: Oddy Robert J. , Willis Philip J.
Published: December 2004

We propose an intuitively simple way of representing colour which has the additional virtue that, it permits mixing and overlaying of transparent and opaque paints to an arbitrary degree. Our approach is related to the earlier alpha channel model used for compositing. It includes this as a special case but has applications in many other areas, especially animation, paint programs and graphics libraries.
A Survey of Several Root‐Finding Methods in the Complex Plane
Authors: Szyszkowicz Mieczyslaw
Published: December 2004

In this paper a few classes of root‐finding iterative methods are presented and used in the complex plane to solve the equation z4− 1 = 0. These methods are studied using computer graphics techniques.
Fat curves
Authors: Yao C. , Rokne J.
Published: December 2004

Fat curves in two‐dimensional Euclidean space are discussed. Previous work on fat curves is reviewed and a new definition is given for a fat curve having a smooth axis. The joining of two fat curves is discussed and a technique for scan‐converting fat curves is presented.
Computer Art from Numerical Methods
Authors: Szyszkowicz Mieczyslaw
Published: December 2004

Zero‐finding methods, Euler's method and the numerical algorithms elaborated as package subroutines are studied by using a computer graphics technique. The patterns obtained show chaotic behaviour (science) and beauty of numerical algorithms (art).
Object‐Oriented Data Modelling for Graphics Databases: a Declarative Approach
Authors: Bhalla Neelam , Balasundaram S.
Published: December 2004

This paper presents a new scheme to integrate the declarative approach to graphics and object‐oriented data modelling techniques to form a fruitful symbiosis for constraint‐based graphics database systems. It has rich modelling constructs to describe graphics data and allows sharing of representation. It also provides useful mechanisms for management of integrity constraints. We have also identified important classes of constraints in the context of object‐oriented graphics database systems. Examples are given for maintenance of constraints at the time of insertion, deletion and modification.
Symmetrical Patterns from Dynamics
Authors: Chung K. W. , Chan H. S. Y.
Published: December 2004

Automatic generation of symmetrical patterns belonging to all seventeen wallpaper groups is considered from a dynamical system's point of view. A pseudo‐code of the algorithm is provided to generate the computer graphics. The method is shown to be able to create unlimited varieties of patterns and demonstrates the possibility of relaxing the crystallographic restriction to produce aperiodic patterns.
Governance Mechanisms for Effective Leadership: the case of Spain
Authors: Ricart Joan , Álvarez José , Gallo Miguel
Published: December 2004

Most current work on Boards of Directors has been focused on what can be considered best practices for effective governance in terms of roles, composition, process and style. Furthermore, this literature can be divided among very practically oriented managerial work, and more rigorous, theoretically based work. Most of the empirical research in this area has been centered on Anglo‐Saxon countries. Some European countries, like Spain, have a very different governance tradition. Given this context, our present work deals with two complementary objectives: 1. To ascertain the current status of governance practices in Spain. 2. To obtain evidence about which of these practices may be associated with effective governance.
Corporate Governance Mechanisms: a plea for less code of good governance and more market control
Authors: Cuervo Alvaro
Published: December 2004

This paper provides a critical comparative analysis of corporate governance mechanisms in market‐oriented (Anglo‐Saxon) and large shareholder‐oriented (Continental European) systems of corporate governance. Deficiencies in shareholder protection in the legal systems of both corporate governance systems have been addressed through the use of codes of good governance, a set of norms that regulate the behaviour and structure of the board of directors. However, the lower enforceability of norms in Continental Europe limits the applicability of such codes. Therefore, we argue that in Continental Europe, rather than promoting codes of good governance, it is necessary to expand market control mechanisms to facilitate the maximisation of firm value.
New Developments in Computer Assisted Creative Problem Solving
Authors: Proctor Tony
Published: December 2004

A new kind of computer assisted creative problem solving method is examined in which visual images are provided to support the process. Until now, much attention has been given to developing programmes which help to structure problems and ideas so that they become more meaningful to the people who are concerned with them. Emphasis has been placed almost entirely on the written word as form of expression. It is argued that a combination of pictorial imagery and written words may be more effective in helping users to gain insights into problems and to come up with ideas or solutions to problems.
Capitalizing on Careabouts to Facilitate Creativity
Authors: Stafford Sue
Published: December 2004

Low‐level knowledge work is work that requires some, but not a great deal, of knowledge to perform. This work sustains the operations of all of our major businesses. As we transform to a knowledge society, it will become increasingly important that this work be performed creatively. Amabile’s well‐researched framework for understanding creative action suggests that reward strategies will be successful if knowledge workers are intrinsically motivated, but low‐level knowledge work more often than not attracts those who lack intrinsic motivation. As a result, the likelihood of creative action for this group of workers is low. How can “garden variety” creative action be facilitated when knowledge workers lack intrinsic motivation? I introduce the notion of “careabouts,” and suggest ways of linking personal careabouts to incorporate objectives. This linkage provides the hook that can hoist these low‐level knowledge workers into creative knowledge work in the knowledge society.
Recovering Memories of Trauma
Authors: McNally Richard J.
Published: December 2004

The controversy over the validity of repressed and recovered memories of childhood sexual abuse (CSA) has been extraordinarily bitter. Yet data on cognitive functioning in people reporting repressed and recovered memories of trauma have been strikingly scarce. Recent laboratory studies have been designed to test hypotheses about cognitive mechanisms that ought to be operative if people can repress and recover memories of trauma or if they can form false memories of trauma. Contrary to clinical lore, these studies have shown that people reporting CSA histories are not characterized by a superior ability to forget trauma-related material. Other studies have shown that individuals reporting recovered memories of either CSA or abduction by space aliens are characterized by heightened proneness to form false memories in certain laboratory tasks. Although cognitive psychology methods cannot distinguish true memories from false ones, these methods can illuminate mechanisms for remembering and forgetting among people reporting histories of trauma.
Retrograde Amnesia
Authors: Riccio David C. , Millin Paula M. , Gisquet-Verrier Pascale
Published: December 2004

Recently, the field of animal memory research has seen a resurgence of interest in the mechanisms underlying retrograde amnesia (RA) and in the use of RA as a technique for studying memory processes. A recent report from a major neuroscience lab, which demonstrated RA for an old reactivated memory, revitalized the debate regarding the widely accepted memory-consolidation theory of RA. Here, we discuss a number of the characteristics of RA and consider the findings that led to the development of the memory-consolidation hypothesis, as well as those suggesting an alternative retrieval-deficit explanation.
Episodic Memory and the Hippocampus
Authors: Eichenbaum Howard , Fortin Norbert
Published: December 2004

Several recent studies have sought to develop animal models of episodic memory, the capacity to recollect unique personal experiences. However, these studies have not yet provided unambiguous evidence that this capacity is based on recollection of the learning episodes. A recent study that examined memory for the ordering of events within unique experiences, and demonstrated a critical and selective role for the hippocampus, suggests a new and promising model for neurobiological analyses of episodic memory.
Ovarian Steroids and Cognitive Function
Authors: Dohanich Gary
Published: December 2004

The ovarian steroids, estrogen and progesterone, not only govern reproductive events in mammalian females but also influence an array of other processes. Of particular clinical interest is the potential of ovarian steroids to facilitate storage of new memories and to protect neurons from various threats. Research during the past decade confirms that estrogen and progesterone influence the biochemical, electrical, and structural properties of neurons in brain regions that subserve learning and memory. These mechanisms form the biological foundations for the complex effects of ovarian steroids on cognitive functions in various species, including humans. Despite significant progress in our understanding of the roles of hormonal factors in cognitive function and neuronal survival, the value of hormone replacement as a treatment and deterrent for cognitive impairments associated with age, disease, and injury remains uncertain as we enter the new century.
Government and Democracy in Mexico’s Federal District, 1997–2001: Cárdenas, the PRD and the Curate’s Egg
Authors: Ward Peter M. , Durden Elizabeth
Published: December 2004

This paper analyses the challenges facing the Partido de la Revolución Democrática (PRD) administration when it became the first elected government of the Federal District in 1997. Through a daily review of press coverage between December 1997–December 2000, complemented by intensive interviewing during summer 1999, five areas of policy‐making activity are analysed and evaluated. The policies entrained and their outcomes show significant advances in decentralization, devolution, and intergovernmental liaison, as well as modest improvements in environmental contamination and reduced crime, although they did not meet the high expectations generated during the Cárdenas campaign for election. However, the fresh image and invigorated confidence that his replacement Rosario Robles brought to the PRD was key in the PRD’s success in the July 2nd 2000 DF elections won by López Obrador. The new administration will have to confront a more plural government structure, including five of the sixteen delegaciones and an evenly divided Legislative Assembly. López Obrador has a full six years in which to prove that a left‐of‐centre political party is capable of developing a ‘Third Way’ of governance in the DF.
Another Textual Frontier: Contemporary Fiction on the Northern Mexican Border
Authors: Vilanova Nú
Published: December 2004

This article approaches fiction writing from the northern Mexican frontier from the perspective of the border. It perceives the border between Mexico and the United States as a multispace that permeates fictional texts from the area. In clear contrast with most Chicano and Border Studies perspectives, the border is viewed here as a physical rather that metaphorical space whose dynamics formulates textual discourses and aesthetics. The fiction works of Luis Humberto Crosthwaite and Jesús Gardea are analysed from this perspective.
The Dilemma of Intellectual Property Rights for Pharmaceuticals: The Tension Between Ensuring Access of the Poor to Medicines and Committing to International Agreements
Authors: Cohen Jillian Clare , Illingworth Patricia
Published: December 2004

In this paper, we provide an overview of how the outcomes of the Uruguay Round affected the application of pharmaceutical intellectual property rights globally. Second, we explain how specific pharmaceutical policy tools can help developing states mitigate the worst effects of the TRIPS Agreement. Third, we put forward solutions that could be implemented by the World Bank to help overcome the divide between creating private incentives for research and development of innovative medicines and ensuring access of the poor to medicine. Fourth, we evaluate these solutions on the basis of utilitarian considerations and urge that equitable pricing is morally preferable to the other solutions.
Fear Recognition and the Neural Basis of Social Cognition
Authors: Skuse David
Published: December 2004

Recent developments in cognitive neuroscience and neurobiology emphasise the interface between our emotions, our feelings and our ability to interact appropriately in social situations. The neural basis of social cognition is subject to intensive research in both humans and non‐human primates, research that is providing exciting, provocative and yet consistent findings. Centre stage is the role of efferent and afferent connectivity between the amygdala and neocortical brain regions, now believed to be critical for the processing of social information. Recent research suggests that a sub‐cortical neural pathway, routed through the amygdala, may turn out to be a key player in the mystery of why humans are so prone to disorders of social cognition. This pathway responds to direct eye contact, one of many classes of potential threat. In humans, arousal evoked by this exquisitely social stimulus is modulated and controlled by a variety of specific cortical regions. Neural circuits that evolved for the purpose of fear detection in other's faces, an essentially threatening stimulus, are now associated with the acquisition of social skills and appropriate responsiveness in social encounters.
Is environmental policy a secondary trade barrier? An empirical analysis
Authors: Ederington Josh , Minier Jenny
Published: December 2004

Abstract Should international trade agreements be extended to include negotiations over environmental policy? The answer depends on whether countries distort levels of environmental regulations as a secondary means of providing protection to domestic industries; our results suggest that they do. Previous studies of this relationship have treated the level of environmental regulation as exogenous, and found a negligible correlation between environmental regulation and trade flows. In contrast, we find that, when the level of environmental regulation is modelled as an endogenous variable, its estimated effect on trade flows is significantly higher than previously reported. JEL Classification: F1, F14, F18

Est‐ce que la politique environnementale est une barrière commerciale secondaire? Une analyse empirique Est‐ce que les accords commerciaux internationaux doivent être étendus pour couvrir la politique environnementale? La réponse dépend du degré de distorsion que les pays introduisent dans leur politique environnementale pour protéger leurs industries nationales. Nos résultats suggèrent que cet impact est important. Des études antérieures de cette relation ont traité la politique environnementale comme exogène, et ont montré qu’il existe une co‐relation négligeable entre politique environnementale et flux commerciaux. Au contraire, nous révélons que, quand la politique environnementale est considérée comme variable endogène, son effet sur les flux commerciaux est plus élevé de manière significative que ce qu’on a noté antérieurement.
Rationalized subjective equilibria in repeated games
Authors: Hidetsugu Oishi
Published: December 2004

Abstract The purpose of this paper is to provide a new equilibrium concept of repeated games that involve incomplete information (rationalized subjective equilibrium) and a related framework (subjective game), and to analyse the relationships between players’ subjective images of games and the realized outcomes. We demonstrate the relationships among rationalized subjective equilibria, subjective equilibria, and original Nash equilibria by providing several examples. We also present several theorems analogous to the ordinary folk theorem and a simple application using the Cournot duopoly model. JEL Classification: C70, C72

Equilibres subjectifs rationalisés dans des jeux répétés L’objectif de cet article est de proposer un nouveau concept d’équilibre dans les jeux répétés où l’information est incomplète (équilibre subjectif rationalisé) et un cadre d’analyse approprié( jeu subjectif ), ainsi que d’analyser les rapports entre les images subjectives que les acteurs ont des jeux et de leurs résultats. On montre les rapports entre équilibres subjectifs rationalisés, équilibres subjectifs, et équilibres à la Nash à l’aide de divers exemples. On présente aussi plusieurs théorèmes analogues au « ordinary folk theorem » et une application simple utilisant le modèle de duopole de Cournot.
A Theology of the Cross for South Africa
Authors: Nolte Claudia M.
Published: December 2004

This article seeks to investigate in what ways the Lutheran theologia crucis ‐ when brought into dialogue with the South African historical‐political context ‐ can be of epistemological as well as pastoral significance for the people of South Africa. South Africa is a nation in the process of coming to terms with a traumatic past of violence, oppression, suffering and injustice. In order for healing and reconciliation to occur, people must find some kind of meaning in the story of the past, and indeed must find the seeds of hope and new beginnings in this story. This article argues that the story of South Africa can be likened to a story of the cross, and that the God of South Africans can be identified as the God of the cross, the Deus absconditus who is mysteriously and paradoxically revealed in suffering and injustice. In identifying the God of the cross as their God, and seeing their story as a story of the cross, South Africans may also anticipate theirs to be(come) a story of the resurrection and of new life.
Context‐dependent symbiosis between black flies (Diptera: Simuliidae) and trichomycete fungi (Harpellales: Legeriomycetaceae)
Authors: McCreadie John W. , Beard Charles E. , Adler Peter H.
Published: December 2004

The context‐dependent nature of a symbiotic relationship between a trichomycete fungus (Smittium culisetae) and a larval black fly (Simulium vittatum) is demonstrated in the present study. No significant difference was found between the size of larvae colonized by trichomycetes and those free of trichomycetes, regardless of the trichospore dosage or initial age of the larvae. This trend suggests that the trichomycete has no detectable effect on host fitness, indicating a commensalistic relationship. However, in half of the experiments, stressed (i.e. starved) larvae exposed to trichospores at a dosage of 20 000 spores ml−1had significantly higher survival than did trichomycete‐free larvae, indicating a mutualistic relationship. Trichomycetes in adult female black flies can replace the ovaries. The symbiotic association between trichomycetes and simuliids, therefore, is dynamic: commensalistic when larvae are well fed, mutualistic when larvae are starved, and parasitic in adults. The trichomycete‐black fly relationship represents a rare case of symbiosis shifting among three states.
Reciprocal effects of host plant and natural enemy diversity on herbivore suppression: an empirical study of a model tritrophic system
Authors: Aquilino Kristin M. , Cardinale Bradley J. , Ives Anthony R.
Published: December 2004

Many theoretical and empirical studies have shown that species diversity in a trophic level can impact the capture of limited resources in ways that cascade up or down a food web. Only recently, however, have ecologists begun to consider how diversity at multiple trophic levels might act in concert to have opposing or reinforcing effects on resource use. Here, we report the results of an empirical study of a model, tritrophic food web in which we manipulated the diversity of host plant species (Medicago sativa,Trifolium pratenseandVicia faba) and natural enemy species (Harmonia axyridis,Coleomegilla maculataandNabissp.) of a widespread herbivorous pest (the pea aphid,Acyrthosiphon pisum) in laboratory microcosms. We found that increasing natural enemy richness from one to three species increased the proportion of aphids consumed by 0.14. This effect of enemy diversity was due to facilitative interactions and/or a reduction in intraspecific competition in the more diverse assemblages. We also found an independent and additive main effect of host plant richness, with the proportion of aphids consumed by natural enemies decreasing by 0.14 in plant polycultures. A reduction in predator efficiency on a single host plant,Vicia faba, appeared to be responsible for this plant diversity effect. Aphid population sizes were, therefore, simultaneously determined by a top‐down effect of natural enemy diversity, and an opposing bottom‐up effect of host plant diversity that modified enemy–prey interactions. These results suggest that population sizes in nature, and biotic controls over insect pests, are influenced by species diversity at multiple trophic levels.
Phenotypic variation and spatial structure of secondary chemistry in a natural population of a tropical tree species
Authors: Brenes‐Arguedas Tania , Coley Phyllis D.
Published: December 2004

To understand herbivore selection in natural plant populations, it is important to understand the landscape of plant chemical phenotypes that herbivores face and the sources of variation that will define this landscape. We studied the spatial patterns of variation in leaf secondary chemistry of the tropical treeQuararibea asterolepis, Pitt. (Bombacaceae) in a natural population on Barro Colorado Island, Panama, and used this background to discuss hypotheses of natural selection by herbivores.Quararibeaplants collected from different sites had consistent differences in their chemical phenotypes. Some of these differences were explained by developmental and environmental sources of variation. Canopy trees had 13% lower yield of leaf extracts than gap seedlings, explained by 41% lower concentrations of the more abundant metabolites in the secondary compound profile. Also, plants growing in gaps had 25% higher yield than those in the understory, explained by two‐fold increases in the concentration of some of the less polar secondary compounds in the profile. Differences in soil type did not affect the secondary chemistry of leaves, but sites with different topography had differences in the secondary compound profile that were not explained by any of the measured environmental sources of variation. Neighboring parent‐offspring pairs and sibling/half sibling clusters displayed equal or higher variance among themselves than unrelated individuals at farther distances. Assuming that related plants should be more similar in their phenotypes, this pattern is consistent with local selection by herbivores overriding the similarity of related plants in a frequency‐ or distance‐dependent manner.