bluuebunny/crossref_metadata_2025 huggingface dataset:
Unravelling the structure of the lamellipodium
Authors: SMALL J.V. , AUINGER S. , NEMETHOVA M. , KOESTLER S. , GOLDIE K.N. , HOENGER A. , RESCH G.P.
Published: August 2008

Pushing at the cell front is the business of lamellipodia and understanding how lamellipodia function requires knowledge of their structural organization. Analysis of extracted, critical‐point‐dried cells by electron microscopy has led to a current dogma that the lamellipodium pushes as a branched array of actin filaments, with a branching angle of 70°, defined by the Arp2/3 complex. Comparison of different preparative methods indicates that the critical‐point‐drying‐replica technique introduces distortions into actin networks, such that crossing filaments may appear branched. After negative staining and from preliminary studies by cryo‐electron tomography, no clear evidence could be found for actin filament branching in lamellipodia. From recent observations of a sub‐class of actin speckles in lamellipodia that exhibit a dynamic behaviour similar to speckles in the lamella region behind, it has been proposed that the lamellipodium surfs on top of the lamella. Negative stain electron microscopy and cryo‐electron microscopy of fixed cells, which reveal the entire complement of filaments in lamellipodia show, however, that there is no separate, second array of filaments beneath the lamellipodium network. From present data, we conclude that the lamellipodium is a distinct protrusive entity composed of a network of primarily unbranched actin filaments. Cryo‐electron tomography of snap‐frozen intact cells will be required to finally clarify the three‐dimensional arrangement of actin filaments in lamellipodia in vivo.
Signal relay during chemotaxis
Authors: GARCIA G.L. , PARENT C.A.
Published: August 2008

The ability of cells to migrate in response to external cues, a process known as chemotaxis, is a fundamental phenomenon in biology. It is exhibited by a wide variety of cell types in the context of embryogenesis, angiogenesis, inflammation, wound healing and many other complex physiological processes. Here, we discuss the signals that control the directed migration of the social amoebae Dictyostelium discoideum both as single cells and in the context of group migration. This multi‐cellular organism has served as an excellent model system to decipher amoeboid‐like leukocyte migration and has played a key role in establishing signalling paradigms in the chemotaxis field. We envision that Dictyostelium will continue to bring forward basic knowledge as we seek to understand the mechanisms regulating group cell migration.
Expert opinion on the treatment of patients with chronic hepatitis C
Authors: Zeuzem S. , Berg T. , Moeller B. , Hinrichsen H. , Mauss S. , Wedemeyer H. , Sarrazin C. , Hueppe D. , Zehnter E. , Manns M. P.
Published: August 2008

Summary.  The current preferred treatment for patients with hepatitis C virus (HCV) is combination therapy consisting of pegylated interferon alfa and ribavirin (RBV) for 24–48 weeks. Although this approach appears to be highly effective for patients with HCV genotypes 2 or 3, who have a sustained virological response (SVR) of approximately 80%, the treatment algorithm is less effective for patients with HCV genotype 1, as these patients have SVR rates of just 40–50%. In order to improve treatment outcomes, this article explores potential approaches for the optimization of treatment for patients with HCV genotype 1: considering shorter treatment periods for patients with a rapid virological response (RVR), increasing treatment periods for slow responders, and increasing RBV dose are all suggestions. Results from clinical trials suggest that approximately 20% of the HCV genotype 1‐infected population are slow responders, and around 15% of all HCV genotype‐1 infected patients could benefit from a shorter treatment duration without compromising the SVR rate. Interest has also focused on whether treatment duration could be individualized in some patients with genotype 2 and 3 infection. Here all the findings from recent studies are translated into practical advice, to help practitioners make evidence‐based treatment decisions in everyday clinical practice. Although there are areas where currently available data do not provide conclusive evidence to suggest amending treatment approaches, there is clearly potential for individualized treatment in all aspects of hepatitis treatment in the future.
Competition between microcystin‐ and non‐microcystin‐producing Planktothrix agardhii (cyanobacteria) strains under different environmental conditions
Authors: Briand Enora , Yéprémian Claude , Humbert Jean‐François , Quiblier Catherine
Published: August 2008

The factors that control the production of microcystins (hepatotoxins) during cyanobacterial blooms, and the function of these metabolites remain largely unknown. In an attempt to provide answers to these questions, we compared the fitness of microcystin (MC)‐producing and non‐MC‐producing Planktothrix agardhii strains under various experimental conditions. More specifically, we investigated the effects of temperature, light intensity and nitrate concentrations on several MC‐producing and non‐MC‐producing strains in monoculture and competition experiments. In the monoculture experiments, no significant difference in cell growth rates was found for any of the environmental conditions tested. On the other hand, at the end of the competition experiments, we found that when the environmental conditions limited cell growth, MC‐producing strains were clearly winning out over the non‐MC‐producing ones. This suggested that, under growth‐limiting conditions, the benefits of producing MC outweigh the cost. Moreover, the reverse was found under non‐growth‐limiting conditions, suggesting that under environmental conditions that favour cyanobacterial growth, the cost of MC production must outweigh its benefits. These findings suggest that environmental factors may have an indirect effect on the MC production rate, and on the selection of MC‐producing and non‐MC‐producing strains, via their direct impact on both the cell growth rate and the cell densities in the cultures. Several hypotheses have been advanced concerning the possible function of MCs, but none of them seems to be supported by our data.
Cooperation and Knowledge Transfer within Buyer–Supplier Relationships: The Moderating Properties of Trust, Relationship Duration and Supplier Performance*
Authors: Squire Brian , Cousins Paul D. , Brown Steve
Published: August 2008

This paper examines the effect of relational factors on knowledge transfer within strategic buyer–supplier exchange. Prior research examining inter‐firm knowledge transfer has focused almost exclusively on horizontal forms of governance such as strategic alliances and joint ventures, whilst research on vertical forms, such as buyer–supplier relationships, is limited. We test the effect of four important relational properties: cooperation, trust, relationship duration and supplier performance. Quantitative data, gathered from 104 UK manufacturing firms in eight industry sectors, are used to analyse the hypothesized relationships through a moderated hierarchical regression model. Our study provides support for the importance of considering relational factors in the transfer of knowledge at the inter‐organizational level. In particular, the results indicate that knowledge transfer is positively influenced by the extent of cooperation, but that this relationship is moderated by the level of trust and the performance of the supplier firm. Managerial implications for these findings and future directions for research are then offered.
The Role of Financial Institutions in the Corporate Governance of Listed Chinese Companies*
Authors: Yuan Rongli , Xiao Jason Zezhong , Milonas Nikolaos , Zou Joe Hong
Published: August 2008

This paper explores the role of Chinese financial institutions in the corporate governance of listed companies through interviews with both senior managers of financial institutions and board directors of listed companies. Our results show that, while most securities companies are passive investors, a good proportion of the active mutual funds help their portfolio companies prepare financial forecasts, standardize their operations, raise external funds, strengthen their company image in the capital markets, and sometimes intervene in corporate issues. This limited role can be attributed to a number of factors specific to the Chinese context including highly concentrated state ownership, an immature regulatory environment, inadequate transparency and disclosure of financial information, and weak corporate governance within financial institutions themselves. It could also be affected by several other factors that are considered to cause institutional passivity in developed countries such as conflicts of interest, monitoring costs and lack of expertise.
Social Competence, Social Support, and Attachment: Demarcation of Construct Domains, Measurement, and Paths of Influence for Preschool Children Attending Head Start
Authors: Bost Kelly K. , Vaughn Brian E. , Washington Wanda Newell , Cielinski Kerry L. , Bradbard Marilyn R.
Published: August 2008

Two studies designed to (1) explore measurement issues for the construct domains of social competence and social support and (2) test a model relating social competence to social support and to child‐parent attachment for low‐income (primarily African American) preschool children attending Head Start are reported. In Study 1, the definition, measurement, and structure of the social competence construct are evaluated in 2 samples of children. For Study 1A, 167 4‐year‐old children were assessed with a battery of observation, interview, and Q‐sort measures. Relations among the measures suggested a hierarchical structure that was tested using a structural equation model. Results from the analysis supported the conjecture that social competence should be viewed as a hierarchically organized construct. In Study 1B, the model was tested again for a group of 3‐and 4‐year‐old children (n= 265), using a modified set of measures. The general structure of the model from Study 1A was reproduced in this independent sample, although paths from the second‐order factor to lower‐order factors were not perfectly coordinated across samples. In Study 2, data for a subset of the children in Study IB (n= 182), gathered with respect to features of their social networks, were examined to assess the structure of their social support networks. Descriptive and structural equation analyses are reported. Sixty‐nine of these children were observed at home with their mothers and described using the Waters Attachment Q‐sort. A structural equation model testing relations consistent with causal pathways from attachment security to both social support networks and to social competence and from the social support network variable to social competence with peers fit these data with a high degree of confidence. Subsequent analyses locating social competence as antecedent to attachment security were not significant. We conclude that the construct domains of social competence and social support networks can be meaningfully measured for preschool children and that individual differences with respect to these construct domains are related to child‐parent relationship qualities.
Preliminary Models of Risk and Protective Factors for Childhood Homesickness: Review and Empirical Synthesis
Authors: Thurber Christopher A. , Sigman Marian D.
Published: August 2008

Empirical research and conventional wisdom have suggested numerous risk and protective factors for the development of homesickness. Yet no study has integrated predictors and sequelae of homesickness into a testable statistical model. As a first step in developing a pathogenic model of homesickness in children, this study measured, factor analyzed, and modeled 14 predictors and 8 sequelae of homesickness. Using a sample of 293 boys, ages 8–16, spending 2 weeks at an overnight summer camp, this study tested 2 alternate models, focusing on the roles of boys' interpersonal attitudes, perceived control, and separation expectations in the subsequent development of homesickness. Results indicated that interpersonal attitudes and perceived control may predict boys' preseparation beliefs about whether they will become homesick. This “homesick disposition” combines with little prior separation experience to account for 69% of the variance in self‐reported homesickness. Homesickness was not a powerful predictor of negative emotion, whereas interpersonal attitudes and perceived control predicted 70% of the variance in negative emotion. Results are discussed in the context of contemporary theories of homesickness.
Age Trends in the Use of Social and Temporal Comparison for Self‐Evaluation: Examination of a Novel Developmental Hypothesis
Authors: Butler Ruth
Published: August 2008

Two studies tested the novel hypothesis that children use social comparison (SC) for self‐appraisal at an earlier age than they do temporal comparison (TC). The effect of other's and of own prior outcome on performance and ability appraisal and on self‐evaluative strategies was examined using simple tasks and outcome information. Results from 840 children at ages 4–8 confirmed that self‐evaluative SC was similar over age. Even 4‐to 5‐year‐olds rated themselves higher after doing better versus worse than another and explained their ratings in terms of explicit SC. Social failure undermined continuing motivation at all ages. In contrast, young children in TC conditions attended only to their last outcome, and comparisons between current and prior outcomes increased with age. Self‐evaluative biases were marked at age 5–6 and for boys in SC conditions. Results clarify the role of cognitive and motivational factors in the development of SC and TC.
Similarities between Friends and Nonfriends in Middle Childhood
Authors: Haselager Gerbert J. T. , Hartup Willard W. , van Lieshout Cornells F. M. , Riksen‐Walraven J. Marianne A.
Published: August 2008

Similarities were assessed between target children (mean age, 11.1 years) and their friends and nonfriends, respectively. One target child of each sex (N= 192), along with one same‐sex friend and one nonfriend, were selected from 102 participating classrooms. “Guess who” nominations obtained within these classrooms were used to measure prosocial behavior, antisocial behavior, shyness/dependency, and sociometric status; self‐reports were used to measure depressive symptoms. Children and their friends were more similar to one another than nonfriends across the entire data set—as the participants were rated by their classmates and as their classmates were rated by the participants. Friendship similarities varied from attribute to attribute, being greater in antisocial behavior than in the other domains. Similarities between friends in sociometric status and size of the friendship network were also greater among socially accepted than nonaccepted children.
Assessing Salivary Cortisol in Studies of Child Development
Authors: Schwartz Eve B. , Granger Douglas A. , Susman Elizabeth J. , Gunnar Megan R. , Laird Brandi
Published: August 2008

In a series of studies, we evaluated the susceptibility of radioimmunoassays (RIA) for saliva cortisol to interference effects caused by oral stimulants used to facilitate saliva collection in studies with children. When added directly to saliva samples, oral stimulants (drink mix crystals) artificially inflated estimated cortisol concentrations. The magnitude of the interference effect was concentration‐dependent and more pronounced for some stimulants and RIA procedures than for others. Analysis of samples collected using oral stimulants from child and adult participants confirmed stimulant interference as an extraneous source of variability in measured saliva cortisol. Associations between serum and saliva cortisol and between saliva cortisol and “behavioral” variables were attenuated by stimulant interference. A survey of six large child studies estimated interference effects, indexed by low sample pH, to be present in 14.7% of the 1,148 total saliva samples, or 2%‐54% (M= 22%) of samples within each study. Recommendations to minimize the impact of stimluant interference in studies involving salivary cortisol in the context of child health and development are outlined.
Tolerance and Intolerance: Children's and Adolescents' Judgments of Dissenting Beliefs, Speech, Persons, and Conduct
Authors: Wainryb Cecilia , Shaw Leigh A. , Maianu Camelia
Published: August 2008

Tolerant and intolerant judgments of different types of dissent were examined. One hundred sixty participants (aged 7,3, 10,4, 13,6, and 20,1) made judgments about dissenting beliefs, speech, practices, and people engaged in those practices. Across all ages, participants were more tolerant (1) of the holding of dissenting beliefs than of their expression, (2) of the expression of beliefs than of the persons engaged in acts based on those beliefs, and (3) of the persons than of the acts. Tolerance of dissenting beliefs and speech increased with age. Although, at all ages, participants were intolerant of the practices, they were relatively more tolerant of practices grounded in cultural contexts. Participants were more tolerant of people espousing dissenting information than dissenting values. We concluded that tolerance and intolerance coexist at all ages and hinge on what individuals are asked to tolerate and on the sense in which they are asked to tolerate it.
Assessing Young Children's Views of Their Academic, Social, and Emotional Lives: An Evaluation of the Self‐Perception Scales of the Berkeley Puppet Interview
Authors: Measelle Jeffrey R. , Ablow Jennifer C. , Cowan Philip A. , Cowan Carolyn P.
Published: August 2008

In a prospective, longitudinal study we examined the psychometric properties of the self‐perception scales of the Berkeley Puppet Interview (BPI). A total sample of 97 young children were assessed with the BPI at 3 time points: preschool, kindergarten, and first grade. The BPI assesses young children's self‐perceptions of their school adjustment in 6 domains: academic competence, achievement motivation, social competence, peer acceptance, depression‐anxiety, and aggression‐hostility. Results showed that 4½‐ to 7½‐year‐olds possess a multidimensional self‐concept that can be reliably measured and that the BPI is sensitive to normative changes and individual differences in young boys' and girls' views of themselves. Support for the method's validity was derived from consistent and meaningful patterns of convergence between children's self‐perceptions and ratings by adult informants–mothers, fathers, and teachers–as well as standardized test scores. In fact, in this study, the concordance between young children's self‐reports and parallel ratings by teachers or mothers were consistently as strong as if not stronger than the concordance between mothers' and teachers' ratings.
Family Relationships and Children's Emotional Adjustment as Correlates of Maternal and Paternal Differential Treatment: A Replication with Toddler and Preschool Siblings
Authors: Volling Brenda L. , Elins Julie L.
Published: August 2008

Recent behavioral genetic research emphasizes the nonshared family environment as an important contributor to psychological differences between siblings raised in the same family. Most studies of nonshared sibling experiences have examined the effects of differential maternal and paternal treatment separately and have not examined family‐level processes. This study attempted to replicate the findings of McHale, Crouter, McGuire, and Updegraff and also of Volling in which relations between family patterns of differential parental treatment, child outcomes, and family functioning were examined. Questionnaire data were collected from 60 maritally intact families with toddler and preschool siblings. Congruence in mothers' and fathers' reports of differential treatment (i.e., similar treatment from both mother and father) was most frequent. Parents' reports of differential enjoyment were related to differential favoritism, whereas their reports of differential discipline were not. Both mothers and fathers were more likely to discipline the older sibling than the younger toddler. Sibling and marital harmony characterized families in which the father disciplined the older sibling more and mothers disciplined the two children equally. Incongruent patterns of differential favoritism (i.e., one parent treats the children equally while the other favors one child) were associated with marital distress. Preschool siblings exhibited greater internalizing and externalizing symptoms when both mothers and fathers disciplined them more than their younger sibling. The findings of this study with very young siblings differ in some respects from those with older children and suggest that future research needs to examine differential parental treatment as a developmental process across childhood.
Rapid Word Learning by Fifteen‐Month‐Olds under Tightly Controlled Conditions
Authors: Schafer Graham , Plunkett Kim
Published: August 2008

Infants (12 to 17 months) were taught 2 novel words for 2 images of novel objects, by pairing isolated auditory labels with to‐be‐associated images. Comprehension was tested using a preferential looking task in which the infant was presented with both images together with an isolated auditory label. The auditory label usually, but not always, matched one of the images. Infants looked preferentially at images that matched the auditory stimulus. The experiment controlled within‐subjects for both side bias and preference for previously named items. Infants showed learning after 12 presentations of the new words. Evidence is presented that, in certain circumstances, the duration of longest look at a target may be a more robust measure of target preference than overall looking time. The experiment provides support for previous demonstrations of rapid word learning by pre‐vocabulary spurt children, and offers some methodological improvements to the preferential looking task.
Children's Understanding of Pictorial and Mental Representations
Authors: Slaughter Virginia
Published: August 2008

Two studies demonstrate dissociation between children's understanding of pictorial representations (photos and drawings) and mental representations (beliefs). In Study 1, 37 preschoolers were tested on false belief, appearance‐reality, false photo, and false drawing tasks. The false picture tasks were significantly easier, and no correlation was found between children's performances on false belief and false picture tasks. In Study 2, 30 children who failed a false belief pretest were randomly assigned to 3 training groups: Belief (trained on false belief tasks), Picture (trained on false picture tasks), or Control (trained on number conservation tasks). Training was conducted in 2 sessions over the course of 2 weeks; tasks were presented and feedback was provided. All children were posttested on theory of mind tasks, false picture tasks, and a number conservation task. The posttest results showed differential patterns of performance, with the Belief group scoring highest on the theory of mind posttests, the Picture group scoring highest on the false picture posttests, and the Control group scoring highest on the number conservation posttest. Results are discussed with respect to competing models of theory of mind development.
The Effects of Theories on Children's Acquisition of Family‐Resemblance Categories
Authors: Krascum Ruth M. , Andrews Sally
Published: August 2008

Two experiments examined whether 4‐ to 5‐year‐olds' acquisition of family‐resemblance categories (for fictitious animals) was benefited by giving them a theory that explained the behaviors of category members (“fighter” versus “hider”) in terms of the relations between functional surface features. As gauged by immediate and 24‐hour‐delayed categorization tests, children who performed theory‐guided learning were more successful at making feature/category associations than those who performed similarity‐guided learning. The Theory group categorized individual attributes significantly better than children for whom features of the training examples were identified simply by pointing and naming (Features condition, Experiment 1) or who were taught unrelated functions for features such that they could not be united within any obvious causal schema (Features Description condition, Experiment 2). These results support claims that mere similarity is insufficient to support category acquisition (Murphy & Medin, 1985) and show that theories giving an explanation for the existence of correlated properties can assist children to learn the distribution of perceptual attributes across categories.
Together Wherever We Go: The Ethnographic Child and the Developmentalist
Authors: Lucariello Joan
Published: August 2008

Krackow and Gordon aim to refute the slot‐filler (SF) model of taxonomic knowledge development. On this model, preschoolers derive “slot‐filler” categories from event schemas. SF categories are items that fill the slots created by the actions or functions within an event. They combine into coordinate categories, based on general functions, in the school‐aged years. This model, which has received considerable empirical support across methodologies, ages, and sociocultural contexts, relies on the “ethnographic child”—one who has knowledge of and participates in a sociocultural world. The SF account is not disproved by Krackow and Gordon, which offers no new or alternative category development account. Their method and theorizing are a poor fit to children, ethnographic or otherwise, undermining the study's capacity to say something reliable and representative about cognition in preschoolers. Moreover, if the data are to be relied on, they are supportive of the SF model.
Children's and Adolescents' Understanding of Rights: Balancing Nurturance and Self‐Determination
Authors: Ruck Martin D. , Abramovitch Rona , Keating Daniel P.
Published: August 2008

This study examined the development of young people's understanding of nurturance and self‐determination rights. One hundred and sixty‐nine participants from 5 age groups (8, 10, 12, 14, and 16 years of age) participated in a semistructured interview containing hypothetical vignettes, in which a story character wished to exercise a self‐determination right or nurturance right that conflicted with the wishes or practices of those in authority. Participants were asked to decide if they would support the story character's request for rights and to justify their decisions. Younger children (8‐ to 12‐year‐olds) were significantly less likely to identify both nurturance and self‐determination rights as salient than were older participants (14‐ to 16‐year‐olds). The types of reasoning participants exhibited for the two types of rights differed at all ages. Reasoning about nurturance rights did not show an age‐related progression from concrete to abstract, whereas reasoning about self‐determination rights was more likely to exhibit such a progression. Results suggest that previous attempts to explain the development of understanding of rights in terms of global stages does not fully capture children's and adolescents' reasoning, and, in particular, such a framework may not account for the differences in young people's thinking about the 2 types of rights.
Stability and Continuity of Child‐Caregiver and Child‐Peer Relationships
Authors: Howes Carollee , Hamilton Claire E. , Philipsen Leslie C.
Published: August 2008

We examined the relationship quality of 55 (27 girls) 9‐year‐old children with their mothers, teachers, and friends as rated by teachers and by the children themselves. The goal of this longitudinal study was to examine stability and continuity in the quality of children's relationships between infancy and 9 years of age. At age 9, children's perception of their relationships with their teachers was associated with their current teachers' ratings of their relationships with the children. Children's perceptions of their relationships with their mothers were consistent with earlier ratings of attachment security. Children's perceptions of their relationships with teachers were predicted by the quality of their attachment relationships with their first teachers. Children's perceptions of their friendship quality was predicted by preschool teacher ratings of friendship quality and the quality of their attachment relationships with their first teachers.
Perceptions of Emotional Support from Mother and Friend in Middle Childhood: Links with Social‐Emotional Adaptation and Preschool Attachment Security
Authors: Booth Cathryn L. , Rubin Kenneth H. , Rose‐Krasnor Linda
Published: August 2008

Children's (N= 58) perceptions of emotional support from mother and best friend were assessed at age 8. Perceptions of support from mother were predicted by attachment security at age 4, suggesting continuity in the children's internal working model of self in relation to mother. Preschool attachment security predicted age 8 perceptions of maternal support better than the mother's actual behavior at age 8. Identification of the best friend as a member of one's emotional support network was not related to security, but was positively related to social competence. However, among insecurely attached children, the greater the reliance on the best friend for emotional support, the greater the externalizing problems. Compensatory effects of best friend support on the social‐emotional adaptation of insecurely attached children were not found.
Psychosocial Adjustment among Children Conceived via Donor Insemination by Lesbian and Heterosexual Mothers
Authors: Chan Raymond W. , Raboy Barbara , Patterson Charlotte J.
Published: August 2008

This study examined the relations among family structure (e.g., number of parents, parental sexual orientation), family process (e.g., parents' relationship satisfaction, interparental conflict), and the psychological adjustment of children who had been conceived via donor insemination. The 80 participating families, all of whom had conceived children using the resources of a single sperm bank, included 55 families headed by lesbian and 25 families headed by heterosexual parents. Fifty families were headed by couples and 30 by single parents. Participating children averaged 7 years of age. Results showed that children were developing in normal fashion, and that their adjustment was unrelated to structural variables such as parental sexual orientation or the number of parents in the household. These results held true for teacher reports as well as for parent reports. Variables associated with family interactions and processes were, however, significantly related to indices of children's adjustment. Parents who were experiencing higher levels of parenting stress, higher levels of interparental conflict, and lower levels of love for each other had children who exhibited more behavior problems.
The Multi‐scale Marked Area‐interaction Point Process: A Model for the Spatial Pattern of Trees
Authors: PICARD NICOLAS , BAR‐HEN AVNER , MORTIER FRÉDÉRIC , CHADŒUF JOËL
Published: August 2008

Abstract. The spatial pattern of trees in forests often combines different types of structure (regularity, clustering or randomness) at different scales. Taking species or size into account leads to marked patterns. The question addressed is to model such multi‐scale marked patterns using a single process. Within the category of Markov processes, the area‐interaction process has the advantage of being locally stable, whether it is attractive or repulsive. This process was originally defined as a one‐scale non‐marked process. We propose an extension as a multi‐scale marked process. Three examples are presented to show the adequacy of this process to model tree patterns: 1. A pine pattern showing anisotropic regularity and clustering at different scales. 2. A bivariate (adult/juvenile) kimboto pattern in French Guiana, showing regularity for one type, clustering for the other and repulsion between the two. 3. A marked pattern in Gabon where the mark is tree diameter.
Social Group and Moral Orientation Factors as Mediators of Religiosity and Multiple Attitude Targets
Authors: MAVOR KENNETH I. , GALLOIS CINDY
Published: August 2008

Although there is a tradition of examining generalized discrimination against multiple targets, recent studies have tended to consider race and homosexuality as separate targets without considering their relationship with each other. Recent studies have also argued for a moral dimension in attitudes to homosexuality, but this has not yet been explicitly modeled as an explanation for patterns of social attitudes. In a questionnaire study of practicing Australian Christians (N= 143), we examined the relationship of religious orientation and ideology (intrinsic, extrinsic, fundamentalism, orthodoxy, and quest) with four attitude targets (Aboriginal Australians, women, homosexual persons, and abortion). Using structural equation modeling (SEM), we develop a two‐factor model, incorporating group and moral orientation factors, which completely mediates the relationships between the religiosity variables and the social attitudes. Religiosity variables exhibit different patterns of correlation with the two factors. The two‐factor model provides a useful framework for further exploration of socially and politically contested attitudes.
Dual citizenship or dual identity? Does ‘transnationalism’ supplant ‘nationalism’ among returning Trinidadians?
Authors: CONWAY DENNIS , POTTER ROBERT B. , ST BERNARD GODFREY
Published: August 2008

In this article we focus on the dual identities of relatively young Trinidadians who have decided to return to the island of their birth, or of their parents, while still in their thirties and forties. Highly‐educated professional transnational migrants mostly make up our sample of 36; 26 possess dual citizenship. We focus on our informants’ narratives about their transnational experiences, self‐appraisals of their dual identities and how they value dual citizenship. More generally, we ask, does transnationalism supplant nationalism among our returning informants? Unsurprisingly, the diverse responses we document do not support the commonly held explanatory relationship between return adaptations, ‘national belonging’ and the expected dominance of ‘transnational belonging’. Family relations intervene significantly, both to encourage transnationalism and to strengthen nationalism. Feelings of national belonging often accompany transnationalism. Notably, we view dual citizenship strategically and pragmatically as advantageous to the continuation of transnational practices.
But are they Meritorious? Genetic Productivity Gains under Plant Intellectual Property Rights
Authors: Kolady Deepthi Elizabeth , Lesser William
Published: August 2008

The objective of this paper is to evaluate the effect of Plant Variety Protection (PVP) on the productive merit/yield increases of US seed varieties. As an example, we use wheat varieties, which are and have been available as both protected and unprotected under PVP from both the public and private sectors. We find evidence that PVP has contributed to the genetic improvement of wheat, using varietal trial data from Washington State. As the private open‐pollinated varieties exist only because of PVP and are higher yielding, these results indicate a clear public benefit from PVP.
Conservation and Adaptation to Climate Change
Authors: BROOKE CASSANDRA
Published: August 2008

Abstract:  The need to adapt to climate change has become increasingly apparent, and many believe the practice of biodiversity conservation will need to alter to face this challenge. Conservation organizations are eager to determine how they should adapt their practices to climate change. This involves asking the fundamental question of what adaptation to climate change means. Most studies on climate change and conservation, if they consider adaptation at all, assume it is equivalent to the ability of species to adapt naturally to climate change as stated in Article 2 of the United Nations Framework Convention on Climate Change. Adaptation, however, can refer to an array of activities that range from natural adaptation, at one end of the spectrum, to sustainability science in coupled human and natural systems at the other. Most conservation organizations deal with complex systems in which adaptation to climate change involves making decisions on priorities for biodiversity conservation in the face of dynamic risks and involving the public in these decisions. Discursive methods such as analytic deliberation are useful for integrating scientific knowledge with public perceptions and values, particularly when large uncertainties and risks are involved. The use of scenarios in conservation planning is a useful way to build shared understanding at the science–policy interface. Similarly, boundary organizations—organizations or institutions that bridge different scales or mediate the relationship between science and policy—could prove useful for managing the transdisciplinary nature of adaptation to climate change, providing communication and brokerage services and helping to build adaptive capacity. The fact that some nongovernmental organizations (NGOs) are active across the areas of science, policy, and practice makes them well placed to fulfill this role in integrated assessments of biodiversity conservation and adaptation to climate change.
The O‐Ring Universal Impression Technique
Authors: Hussaini Souheil
Published: August 2008

Recording the implant position for master cast fabrication for multiple implant systems may require a large inventory of impression copings. A technique is described whereby implant impression‐making procedures can be modified to be more universal to all implant systems. This makes the procedure more cost‐effective by simply incorporating the use of a rubber O‐ring on the abutment or fixture mount, which then eliminates the use of a transfer coping. This technique can be applied at the time of surgery for indexing as well as during the final impression appointment.
Pacemaker Therapy for Early and Late Sinus Node Dysfunction in Orthotopic Heart Transplant Recipients: A Single‐Center Experience
Authors: LUEBBERT JEFFREY J. , LEE FORRESTER A. , ROSENFELD LYNDA E.
Published: August 2008

Background:

Sinus node dysfunction (SND) is a well‐known early complication of orthotopic heart transplantation (OHT). Its incidence over the lifetime of transplant recipients is less well characterized. The goal of this study was to determine the incidence and timing of SND treated with a permanent pacemaker in a large cohort of OHT recipients.

Methods:

The databases of the Yale University Heart Transplant and Electrophysiology Services were reviewed and cross referenced. Patients who received pacemakers for SND were identified for analysis. A total of 241 patients underwent OHT using biatrial anastamoses from 1984 to 2006. Two hundred sixteen patients, 149 men and 55 women, mean age 50.2 ± 11.6 years, survived > 5 days post‐OHT. These, minus 12 lost to follow‐up, were included in the analysis.

Results:

These 204 patients were followed in the Yale Heart Transplant Clinic and had yearly electrocardiograms and 24‐hour ambulatory monitoring. Of these patients, 24 (four female, 20 male, mean age at transplant 49 ± 12 years) were felt to have clinically significant SND and received a pacemaker. Fourteen patients received pacemakers within 30 days of OHT; 10 patients received pacemakers 45 to 4,329 days after OHT.

Conclusions:

Although frequently seen as an early complication of OHT, SND remains a risk throughout the lifetime of OHT recipients. Its mechanism is likely multifactorial, and whether this risk can be mitigated over the long term by newer techniques such as bicaval anastamoses remains to be established.
Protracted CRP Elevation after Atrial Fibrillation Ablation
Authors: McCABE JAMES M. , SMITH LISA M. , TSENG ZIAN H. , BADHWAR NITISH , LEE BYRON K. , LEE RANDALL J. , SCHEINMAN MELVIN M. , OLGIN JEFFREY E. , MARCUS GREGORY M.
Published: August 2008

Background: Atrial fibrillation (AF) has been linked to an inflammatory process detected through various biomarkers, including C‐Reactive Protein (CRP). Early recurrence of AF within the first 3 months after curative AF ablation is not felt to reflect success or failure of the procedure. We hypothesized that this early recurrence is due to an inflammatory response to the ablation itself. We therefore sought to evaluate levels of CRP after AF ablation.

Methods: We prospectively enrolled subjects undergoing AF ablation. A control group of patients undergoing ablation for supraventricular tachycardia (SVT) was also enrolled. Each patient had CRP drawn on the day of the procedure (prior to ablation) and during their first follow‐up (median 49 days, interquartile range [IQR] 37–93) and second follow‐up (median 147 days, IQR 141–257) clinic visits. Patient interviews were performed and medical histories reviewed for evidence of recurrent AF prior to the first follow‐up.

Results: CRP levels significantly increased from baseline to first follow‐up in the AF ablation group (P = 0.0017). CRP did not significantly change after SVT ablation (P = 0.92). Seventeen (45%) of the AF subjects exhibited recurrence of AF prior to first follow‐up. After adjusting for multiple potential confounders, AF ablation patients with recurrent AF prior to their first follow‐up had a statistically significant greater odds of having an increase in CRP (OR 21, 95% CI 1.1–417, P = 0.045).

Conclusions: AF ablation generates an inflammatory response that persists for several weeks. This inflammation may explain early recurrence of AF after curative ablation.
Health‐Related Quality of Life in Brazilian Pacemaker Patients
Authors: OLIVEIRA BRUNA G. , VELASQUEZ‐MELENDEZ GUSTAVO , RINCÓN LEONOR G. , CICONELLI ROZANA M. , SOUSA LIDIANE A. , RIBEIRO ANTONIO L.
Published: August 2008

Background:

Most quality of life (QoL) studies of pacemaker patients have been conducted in either North America or Europe and their applicability to Latin American populations is largely unknown. Our aim is to study health‐related QoL indices in Brazilian pacemaker patients and their determinants using both a generic (SF‐36) and a disease‐specific questionnaire (AQUAREL).

Methods:

The study enrolled 139 clinically stable patients (aged 59 ± 14, 60.4% female) without any communication or cognitive impairments who went to the Pacemaker Laboratory for postimplantation follow‐up. All patients were submitted to a standard protocol, which included an interview, functional class assessment, and QoL questionnaires. Additionally, 74 patients were requested to perform a 6‐minute walk test.

Results:

Female patients and patients without a partner displayed low QoL scores in both the SF‐36 mental component summary and the AQUAREL arrhythmia domain. Chagas disease patients displayed low scores only in AQUAREL domains. All health‐related QoL scores were low in patients with the worst, high‐numbered functional classes, the strongest determinant of low QoL scores in multivariate analysis.

Conclusion:

In this first systematic study of QoL in a Latin American pacemaker population, AQUAREL detected well‐impaired health‐related QoL scores in different groups of patients, particularly in those with Chagas disease. Heart failure, evaluated by functional class, was the strongest predictor of low QoL in pacemaker patients.
Histopathologic Effects of Endocardial and Epicardial Percutaneous Radiofrequency Catheter Ablation in Dilated Nonischemic Cardiomyopathy
Authors: MAURY PHILIPPE , ESCOURROU GHISLAINE , GUILBEAU CELINE , DUPARC ALEXANDRE , HEBRARD AURELIEN , DELAY MARC
Published: August 2008

We report the histological evaluation of both endocardial and epicardial radiofrequency (RF) ablation lesions in the explanted heart of a patient presenting with nonischemic dilated cardiomyopathy complicated by recurrent electrical storms. In this case, chronic RF lesions were almost transmural at the endocardial side, while remaining only superficial at the epicardial aspect, possibly because of the insulating interposed epicardial fat layer.
Presence‐Only Data and the EM Algorithm
Authors: Ward Gill , Hastie Trevor , Barry Simon , Elith Jane , Leathwick John R.
Published: August 2008

SummaryIn ecological modeling of the habitat of a species, it can be prohibitively expensive to determine species absence. Presence‐only data consist of a sample of locations with observed presences and a separate group of locations sampled from the full landscape, with unknown presences. We propose an expectation–maximization algorithm to estimate the underlying presence–absence logistic model for presence‐only data. This algorithm can be used with any off‐the‐shelf logistic model. For models with stepwise fitting procedures, such as boosted trees, the fitting process can be accelerated by interleaving expectation steps within the procedure. Preliminary analyses based on sampling from presence–absence records of fish in New Zealand rivers illustrate that this new procedure can reduce both deviance and the shrinkage of marginal effect estimates that occur in the naive model often used in practice. Finally, it is shown that the population prevalence of a species is only identifiable when there is some unrealistic constraint on the structure of the logistic model. In practice, it is strongly recommended that an estimate of population prevalence be provided.
A Bayesian Approach to Modeling Associations Between Pulsatile Hormones
Authors: Carlson Nichole E. , Johnson Timothy D. , Brown Morton B.
Published: August 2008

SummaryMany hormones are secreted in pulses. The pulsatile relationship between hormones regulates many biological processes. To understand endocrine system regulation, time series of hormone concentrations are collected. The goal is to characterize pulsatile patterns and associations between hormones. Currently each hormone on each subject is fitted univariately. This leads to estimates of the number of pulses and estimates of the amount of hormone secreted; however, when the signal‐to‐noise ratio is small, pulse detection and parameter estimation remains difficult with existing approaches. In this article, we present a bivariate deconvolution model of pulsatile hormone data focusing on incorporating pulsatile associations. Through simulation, we exhibit that using the underlying pulsatile association between two hormones improves the estimation of the number of pulses and the other parameters defining each hormone. We develop the one‐to‐one, driver–response case and show how birth–death Markov chain Monte Carlo can be used for estimation. We exhibit these features through a simulation study and apply the method to luteinizing and follicle stimulating hormones.
The Innovative Materiality of Revitalization Movements: Lessons from the Pueblo Revolt of 1680
Authors: LIEBMANN MATTHEW
Published: August 2008

ABSTRACT Although Wallace's revitalization movement model has been successfully utilized in scores of ethnographic and ethnohistorical studies of societies throughout the world, revitalization is considerably less well documented in archaeological contexts. An examination of the materiality of revitalization movements affords an opportunity to redress this lack by investigating how material culture creates and constrains revitalization phenomena. In this article, I reconsider the revitalization model through a case study focusing on the archaeology of the Pueblo Revolt of 1680, emphasizing the central role of materiality in the formation and mediation of these movements. In doing so, I examine the archaeological signatures of revitalization movements, concluding that they are highly negotiated and heterogeneous phenomena and that the materiality of these episodes cultivates cultural innovation. I also seek to demonstrate that the distinctive types of material culture produced through revitalization are not epiphenomenal but, rather, are crucially constitutive of revitalizing processes.