bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction of Intestinal Lymphoid Tissue
Authors: LÜGERING ANDREAS , KUCHARZIK TORSTEN
Published: October 2006

Abstract:  The intestinal immune system includes several organized structures, such as Peyer's patches, isolated lymphoid follicles (ILFs), cryptopatches (CPs) as well as mesenteric lymph nodes (MLNs) that constitute an extensive network with other nonorganized parts, such as intraepithelial and lamina propria lymphocytes. CPs are small clusters of lymphoid cells with an immature lymphocyte phenotype and dendritic cells. Initial observations in transfer experiments suggested that the immature lymphocytes are T cell precursors and CPs are a potential site of extrathymic intraepithelial lymphocyte (IEL) differentiation. This feature has recently been challenged particularly by the observation that CP cells express the orphan receptor RORγt and are phenotypically indistinguishable from lymphoid tissue‐inducer (LTi) cells, suggesting that CP cells are the adult counterpart of fetal LTi cells. In addition, the chemokine receptor CCR6 is specifically expressed by precursor cells within CPs and its deletion inhibits the development of ILFs. Therefore, it is likely that ILFs derive from CPs under the control of CCR6 under inflammatory conditions and might constitute a valuable target for anti‐inflammatory therapies.
Neutrophil Transepithelial Migration and Epithelial Barrier Function in IBD
Authors: CHIN ALEX C. , PARKOS CHARLES A.
Published: October 2006

Abstract:  Neutrophil (PMN) transmigration across mucosal epithelia is a hallmark of inflammatory conditions, such as ulcerative colitis and Crohn's disease. PMN accumulation within epithelial crypts and in the intestinal lumen directly correlates with clinical disease activity and epithelial injury. Currently, the mechanisms by which PMNs migrate across mucosal epithelia are incompletely understood and a better understanding of this process will likely provide new insights into novel treatment strategies for inflammatory bowel disease. In this article, we discuss current advances that define PMN transepithelial migration, specifically focusing on PMN–epithelial adhesive interactions and signaling events. We also describe how these interactions might be specifically targeted for the development of therapeutic strategies to manage mucosal inflammation.
Role of Macrophage Metalloelastase in Gut Inflammation
Authors: PENDER SYLVIA L.F. , LI C.K.F. , SABATINO A.D.I. , MACDONALD T.T. , BUCKLEY M.G.
Published: October 2006

Abstract:  Matrix metalloproteinases (MMPs) are involved in a number of physiological and pathologic processes including the inflammation found in IBD. We have shown that MMP‐3 is upregulated in Crohn's disease and in ulcerative colitis. This study shows a potential role for MMP‐12 in these idiopathic diseases.
Toll‐Like Receptor Expression and Response to Specific Stimulation in Adipocytes and Preadipocytes
Authors: PIETSCH J. , BATRA A. , STROH T. , FEDKE I. , GLAUBEN R. , OKUR B. , ZEITZ M. , SIEGMUND B.
Published: October 2006

Abstract:  Data in this study indicate that both adipocytes and preadipocytes express abroad set of TLRs and they also respond to specific stimulation by cytokine production. The may be of relevance to Crohn's disease and a suggests a closer link between adipose tissue and innate immunity.
Homeostatic Effects of TLR9 Signaling in Experimental Colitis
Authors: LEE JONGDAE , RACHMILEWITZ DANIEL , RAZ EYAL
Published: October 2006

Abstract:  The commensal microflora of the intestinal tract confer multiple health benefits to the host, including amelioration of inflammatory bowel disease (IBD). Yet, the exact mechanisms by which it ameliorates experimental colitis in animals and human IBD are largely unknown. We tested whether the attenuation of experimental colitis by probiotic bacteria is mediated by toll‐like receptor (TLR) signaling. The severity of colitis was attenuated by delivery of nonviable, γ‐irradiated, or by viable probiotics, but not by heat‐killed probiotics, in wild‐type mice in mice deficient in TLR2 or TLR4. In contrast we did not observe any inhibition of experimental colitis by probiotics, in mice deficient in MyD88 or TLR9. Furthermore, administration of probiotic DNA ameliorated the severity of experimental colitis, whereas methylated probiotic DNA, calf thymus DNA, and Dnase‐treated probiotics had no effect. In subsequent studies, we identified that TLR9‐induced type 1 IFN mediates the anti‐inflammatory effects in experimental colitis. The addition of neutralization antibodies to type 1 IFN abolished the anti‐inflammatory effects, whereas the administration of recombinant IFN‐β mimicked the anti‐inflammatory effects induced by TLR9 agonists.Taken together, these results indicate that the protective effects of probiotics are mainly mediated by their own DNA rather than by their metabolites or their ability to colonize the colon. These findings underscore the diverse effects of indigenous microbial TLR ligands in intestinal homeostasis and intestinal inflammation and suggest that strategies, that modulate type 1 IFN may be of therapeutic value for intestinal inflammatory conditions.
IL‐10 Gene‐Deficient Mice Lack TGF‐Beta/Smad‐Mediated TLR2 Degradation and Fail to Inhibit Proinflammatory Gene Expression in Intestinal Epithelial Cells under Conditions of Chronic Inflammation
Authors: RUIZ PEDRO A. , SHKODA ANNA , KIM SANDRA C. , SARTOR R. BALFOUR , HALLER DIRK
Published: October 2006

Abstract:  Nonpathogenic enteric bacterial species initiate and perpetuate experimental colitis in interleukin‐10 geneeficient mice (IL‐10‐/‐). Bacteria‐specific effects on the epithelium are difficult to distinguish because of the complex nature of the gut microflora. We showed that IL‐10‐/‐ mice compared to wild‐type mice fail to inhibit pro‐inflammatory gene expression in native intestinal epithelial cells after the colonization with colitogenic Gram‐positive Enterococcus faecalis. Of interest, pro‐inflammatory gene expression was transient after 1 week of E. faecalis monoassociation in IECs from wild‐type mice but persisted after 14 weeks of bacterial colonization in IL‐10‐/‐ mice. Accordingly, wild‐type IECs expressed phosphorylated NF‐kappaB subunit RelA (p65) and phosphorylated Smad2 only at day 7 after bacterial colonization, whereas E. faecalis‐monoassociated IL‐10‐/‐ mice triggered persistent RelA but no Smad2 phosphorylation in IECs at days 3, 7, 14, and 28. Consistent with the induction of TLR2‐mediated RelA phosphorylation and pro‐inflammatory gene expression in E. faecalis‐stimulated cell lines, TLR2 protein expression was absent after day 7 from E. faecalis‐monoassociated wild‐type mice but persisted in IL‐10‐/‐ IECs. Of note, TGF‐beta‐activated Smad signaling was associated with the loss of TLR2 protein expression and the inhibition of NF‐kappa Bependent gene expression in E. faecalis‐stimulated IEC lines. In conclusion, E. faecalis‐monoassociated IL‐10‐/‐ but not wild‐type mice lack protective TGF‐beta/Smad signaling and fail to inhibit TLR2‐mediated pro‐inflammatory gene expression in the intestinal epithelium, suggesting a critical role for IL‐10 and TGF‐beta in maintaining normal epithelial cell homeostasis in the interplay with commensal enteric bacteria.
Molecular Mechanisms of Disturbed Electrolyte Transport in Intestinal Inflammation
Authors: SEIDLER URSULA , LENZEN HENRIKE , CINAR AYHAN , TESSEMA TESFAYE , BLEICH ANDRÉ , RIEDERER BRIGITTE
Published: October 2006

Abstract:  Diarrhea is the hallmark of both ulcerative colitis (UC) and Crohn's disease. Loss of resorptive area, destruction of epithelial cells, leaky tight junctions, and release of inflammatory mediators and products from immune cells that stimulate fluid secretion all have been implicated in the pathogenesis of inflammatory diarrhea. Very early studies in patients, however, have pinpointed the overwhelming transport abnormality in inflamed intestinal mucosa: a virtually complete loss of sodium resorptive capacity. Recently, tools have become available to study the molecular basis of disturbances in the major electrolyte transport systems during intestinal inflammation. This review gives a brief overview of the historical development of research related to electrolyte transport in inflammatory bowel disorders, focusing on the studies performed in humans, and highlights recent understanding of the molecular mechanisms that may help explain the origin of diarrhea in intestinal inflammation.
The Bacterial Weaponry
Authors: SANSONETTI PHILIPPE J.
Published: October 2006

Abstract: 
Shigella, a Gram‐negative bacterial species of the family Enterobacteriaceae, causes bacillary dysentery in humans, an acute rectocolitis that reflects the capacity of the microorganism to disrupt, invade, and cause the inflammatory destruction of the intestinal epithelium. Here, the pathogenesis of Shigella infection is analyzed in the context of the disruption of the homeostatic balance that protects the gut against inflammation in the presence of its commensal flora. Thus a unified view by which enteroinvasive pathogens allow identification of key signalling molecules and pathways involved in the regulation of intestinal inflammation, thereby providing keys to understand inflammatory bowel diseases (IBDs) such as Crohn's disease and ulcerative colitis.
Disrupted Barrier Function through Epithelial Cell Apoptosis
Authors: SCHULZKE JOERG‐DIETER , BOJARSKI CHRISTIAN , ZEISSIG SEBASTIAN , HELLER FRANK , GITTER ALFRED H. , FROMM MICHAEL
Published: October 2006

Abstract:  Epithelial barrier function is determined by trans‐ and paracellular permeabilities, the latter of which is mainly influenced by tight junctions (TJs) and apoptotic leaks within the epithelium. The present article aims to present experimental evidence for a functional role of epithelial apoptoses by means of cell culture models as well as in tissues from patients with inflammatory bowel disease. It is shown that epithelial apoptoses are sites of elevated conductance within the intestinal epithelium and that proinflammatory cytokines like TNF‐α upregulate both the apoptotic rate and single apoptotic conductivity, making cytokine‐induced apoptosis functionally far more relevant than is spontaneous apoptosis. In ulcerative colitis and Crohn's disease (CD), but not in collagenous colitis, apoptotic rates are increased to about 5%, in mild‐to‐moderately inflamed colon specimens, where as the control apoptotic rate is about 2%. Thus, epithelial apoptoses lead to a loss of ions and water into the intestinal lumen, causing leak flux diarrhea and enabling small antigens of <4,000 Da in the intestinal lumen to enter the intestinal mucosa, thereby perpetuating inflammatory responses. In addition to TNF‐α, interleukin (IL)‐13 is an important inductor of epithelial apoptosis in Th2 immune responses. Therapeutically,TNF‐α‐antibodies (infliximab) can restore barrier function in Crohn's disease by downregulating epithelial apoptoses, while epithelial TJs are unaffected.
Peyer's Patches and M Cells as Potential Sites of the Inflammatory Onset in Crohn's Disease
Authors: GULLBERG ELISABET , SÖDERHOLM JOHAN D.
Published: October 2006

Abstract: Clinical observations suggest that the sites of initial inflammation in ileal Crohn's disease (CD) are the lymphoid follicles, where the aphtoid lesions originate from small erosions of the follicle‐associated epithelium (FAE). Lymphoid follicles and Peyer's patches (PPs) consist of a number of B‐cell follicles with intervening T cell areas. The T cell follicular area is also populated by dendritic cells (DCs) and macrophages. A single layer of epithelial cells covering each follicle forms a dome between the surrounding villi. This FAE differs from normal villus epithelium in several ways that make the epithelial cells of the FAE more exposed to the luminal contents, more accessible to antigens, and in closer contact with the immune system. The most prominent feature is the presence of specialized M cells, which are optimized for antigen adherence and transport. M cells play an important role in the surveillance of the intestinal lumen, but also provide a route of entry for various pathogens. In this article we review the current knowledge on the epithelial phenotype of the human FAE, and changes of the FAE and M cells in intestinal inflammation, leading to a hypothesis of the role of the FAE and M cells in the pathogenesis of CD.
Role of Lymphotoxins in the Development of Peyer's Patches and Mesenteric Lymph Nodes
Authors: SPAHN THOMAS W. , MÜLLER MICHAEL K. , DOMSCHKE WOLFRAM , KUCHARZIK TORSTEN
Published: October 2006

Abstract:  Hallmarks of the adaptive immune system are antigen‐specific cellular and humoral immune responses. Secondary lymphoid organs serve as sites of contact between antigen‐presenting cells (APCs) and immune effector T and B lymphocytes. The gut‐associated lymphatic system (GALT) as the intestinal branch of the immune system provides different mechanisms to protect organisms against pathogens. Simultaneously, immune activation secondary to genetic factors and/or environmental signals can induce detrimental autoimmunity. The effector pathways in host defense and autoimmunity use similar cytokines and chemokines. Unlike few other cytokines, lymphotoxin (LT) α/β regulates the development of intestinal lymphoid organs, including Peyer's patches (PPs) and mesenteric lymph nodes (MLNs). In addition, intestinal inflammation is suppressed by inhibition of LTβ signalling, an observation which has initiated clinical studies using this treatment principle. Conversely, the course of Citrobacter rodentium–induced infectious colitis is more severe in mice with impaired LTβ‐receptor‐mediated signalling. This report provides an overview on the role of the different organs of the GALT in intestinal inflammation. Moreover, it describes the role of the LTβ‐receptor‐mediated signalling in intestinal inflammation as encountered in autoimmune and infectious pathology. The contribution of LT to the delicate balance of immune effector functions in host defense and autoimmunity is discussed.
A New Look at Crohn's Disease
Authors: WEHKAMP JAN , STANGE EDUARD F.
Published: October 2006

Abstract:  Crohn's disease (CD), a chronic inflammatory disease of the intestinal mucosa is usually located in the small intestine (ileum) and or in the colon. Ileal CD has been linked to a mutation in the NOD2 gene, a bacterial recognition protein. A disturbed antimicrobial defense as provided by an arsenal of different epithelial defensins seems to be a critical factor in disease pathogenesis. Defensins are antimicrobial peptides and in the ileum are mainly expressed in Paneth cells (PCs), epithelial cells that also express NOD2. In the colon, defensins are expressed by enterocytes or metaplastic PCs. Ileal CD patients are characterized by a reduced antibacterial activity and a specific reduction of ileal PC defensins. In ileal Crohn's patients displaying a NOD2 mutation, this decrease is even more pronounced. In contrast, CD of the colon is characterized by an impaired induction of beta defensins in enterocytes. In conclusion, the regional localizations of CD, either ileal or colonic disease, can be linked to different defects in defensin expression. In line with these new findings, we predict that future therapeutic strategies aimed at restoring the host–microbe balance at the intestinal mucosa may prove superior to those that broadly suppress inflammation and adaptive immunity.
Perinodal Adipose Tissue and Fatty Acid Composition of Lymphoid Tissues in Patients with and without Crohn's Disease and Their Implications for the Etiology and Treatment of CD
Authors: WESTCOTT EDWARD D.A. , MATTACKS CHRISTINE A. , WINDSOR ALASTAIR C.J. , KNIGHT STELLA C. , POND CAROLINE M.
Published: October 2006

Abstract:  The physiological bases for roles of adipose tissue and fatty acids in the symptoms and dietary treatments of Crohn's disease are poorly understood. The hypothesis developed from experiments on rodents that perinodal adipocytes are specialized to provision adjacent lymphoid tissues was tested by comparing the composition of triacylglycerol fatty acids in homologous samples of mesenteric adipose tissue and lymph nodes from patients with or without Crohn's disease. Mesenteric perinodal and other adipose tissue, and lymph nodes, were collected during elective surgery for Crohn's disease and other conditions. Fatty acids were extracted, identified, and quantified by thin‐layer and gas‐liquid chromatography. Perinodal adipose tissue contained more unsaturated fatty acids than other adipose tissue in controls, as reported for other mammals, but site‐specific differences were absent in Crohn's disease. Lipids from adipose and lymphoid tissues had more saturated fatty acids, but fewer polyunsaturates in Crohn's disease patients than controls. In adipose tissue samples, depletion of n‐3 polyunsaturates was greatest, but n‐6 polyunsaturates, particularly arachidonic acid, were preferentially reduced in lymphoid cells. Ratios of n‐6/n‐3 polyunsaturates were higher in adipose tissue but lower in lymphoid cells in Crohn's disease patients than in controls. Site‐specific differences in fatty acid composition in normal human mesentery are consistent with local interactions between lymph node lymphoid cells and adjacent adipose tissue. But these site‐specific properties are absent in Crohn's disease, causing anomalies in composition of lymphoid cell fatty acids, which may explain the efficacy of elemental diets containing oils rich in n‐6 polyunsaturates.
Intestinal Epithelial Antigen Induces CD4+ T Cells with Regulatory Phenotype in a Transgenic Autoimmune Mouse Model
Authors: WESTENDORF ASTRID M. , BRUDER DUNJA , HANSEN WIEBKE , BUER JAN
Published: October 2006

Abstract:  Regulatory T cells play a crucial role in the control of immune responses in the intestinal mucosa and their absence may predispose to inflammatory bowel disease (IBD). However, the induction of regulatory T cells at sites of mucosal inflammation is not yet fully understood and may involve antigen presentation by local immature dendritic cells and/or intestinal epithelial cells (IECs). VILLIN‐HA mice, which express the hemagglutinin (HA) from influenza virus A exclusively in enterocytes of the intestinal epithelium, were matched with T cell receptor (TCR)‐HA mice expressing an αβ‐TCR which recognizes a major histocompatibility complex (MHC) class II‐restricted epitope of HA in order to determine the impact of antigen presentation by IECs on CD4+ T cell immunity. In VILLIN‐HA × TCR‐HA mice, peripheral HA‐specific lymphocytes showed an activated phenotype and increased infiltration into the intestinal mucosa without destruction of the intestinal epithelium. Mucosal lymphocytes from VILLIN‐HA × TCR‐HA mice secreted lower amounts of interferon‐γ (IFN‐γ) and interleukin‐2 (IL‐2) and exhibited an increased expression of interleukin‐10 (IL‐10), Nrp‐1, and Foxp3, molecules published as markers for regulatory T cells. IECs can take up and process antigen but the antigen presentation capacity of these cells is often inefficient. Functional and molecular characterization of IECs from VILLIN‐HA and VILLIN‐HA × TCR‐HA transgenic mice revealed a direct role in the induction of CD4+ T cells with a regulatory phenotype that maintain intestinal homeostasis.
Microbial‐Epithelial Cell Crosstalk during Inflammation
Authors: KAGNOFF MARTIN F.
Published: October 2006

Abstract:  The intestinal epithelium forms a single cell barrier that separates the host's internal milieu from luminal contents. This article examines the role of the intestinal epithelium as a critical component of a communications network that is essential for transmitting signals generated in response to infection with microbial pathogens to cells of the innate and acquired immune systems in the underlying intestinal mucosa. It further highlights the importance of intestinal epithelium in mediating host antimicrobial defense through the production of antimicrobial peptides of the defensin and cathelicidin families.
Measuring College Student Drinking
Authors: Huang Jiun-Hau , Dejong William , Schneider Shari Kessel , Towvim Laura Gomberg
Published: October 2006

This study explored the feasibility of a Composite Drinking Scale (CDS) designed to capture fully the phenomenon of problem drinking among college students while allowing easy public understanding. A survey conducted at 32 four-year U.S. colleges included four consumption measures: 30-day frequency; average number of drinks per week; number of drinks usually consumed when partying; and greatest number of drinks in one sitting in the past two weeks. Responses were normalized and added to create a continuous distribution, which was then subdivided into quartiles (CDS/Q1-Q4). The CDS is an easily understood scoring system, but compared to the simplistic “binge drinking” measure, it captures a broader range of relative risks and more clearly establishes the quadratic relationship between consumption and alcohol-related problems. Development of the CDS will require further exploring the best set of questions to include, establishing U.S. norms for the general population, and then transforming those scores to a simple measurement yardstick whose meaning can be easily communicated to the public.
Ethnic identity, ego identity, and psychological well‐being among mixed‐ethnic Arab‐European adolescents in Israel
Authors: Abu‐Rayya Hisham Motkal
Published: October 2006

This study explored the relationship between ethnic identity, ego identity, and psychological wellbeing among mixed‐ethnic adolescents with European mothers and Arab fathers in Israel. One hundred and twenty‐seven mixed‐ethnic adolescents (13 to 18 years) were instructed to respond to a modified version ofPhinney's (1992)Multigroup ethnic identity measure (MEIM), toBennion and Adams' (1986)ego identity measure (EOM‐EIS) and toRyff's (1999)psychological well‐being scale. It was found that Arab and European ethnic identities, composed of ethnic behaviours, affirmation and belonging, and achievement of a sense of oneself as part of an ethnic group, were significantly positively correlated with participants' psychological well‐being. Findings revealed also that the ego identity statuses Achievement and Moratorium were associated with higher levels of psychological well‐being, while the statuses Foreclosure and Diffusion were associated with lower levels of well‐being. Arab and European ethnic identities and ego identity were found to be formed independently among the participants.
Children's evaluations of ambiguous provocation by relationally aggressive, physically aggressive and prosocial peers
Authors: Goldstein Sara E. , Tisak Marie S. , Persson Anna V. , Boxer Paul
Published: October 2006

The present study assessed children's evaluations of hypothetical peer provocation. Participants (N = 75, ages 8–11) were presented with hypothetical vignettes depicting relationally aggressive, physically aggressive and prosocial peers engaging in provocative behaviours directed at the participant, including (a) relational (not receiving a party invitation); (b) physical (having a beverage spilled on him/her); and (c) prosocial (being given stale snack food) provocations. Children rated the hostility of the peer's intentions and explained what they themselves would do if actually confronted with the situation. Children were more hostile in their attributions for the behaviour of relationally and physically aggressive peers as compared with the prosocial peers. Additionally, when children reported that they liked the peer, they were less likely to attribute hostility to that peer's behaviour. Results involving children's responses indicate the importance of considering peer reputation and provocation type when examining children's social problem solving. For example, very few children said that they would seek help from an adult when relationally provoked by an aggressive peer; however, in response to physical provocation from an aggressive peer, seeking the assistance of an adult was a common response.
Development of the perception of object containment in 9‐ to 16‐month‐olds
Authors: Dejonckheere Peter J. N. , Smitsman Ad W. , Denève Leni Verhofstadt
Published: October 2006

In the present study, 9‐, 12‐ and 16‐month‐old infants were familiarized to a block that was repeatedly lowered into a container and lifted from that container again. In the subsequent test phase, the block passed through the container opening either without making contact with the container rim or colliding with the rim in three places but ‘magically’ passing through. In Experiment 1 an opaque black screen was positioned just below the blocks' starting position. In Experiment 2 the screen was put at the height of the container rim and thus occluded the critical arrival phase of the trajectory. Results showed that looking times depended on what infants perceived as happening at the height of the rim and not on what they could have perceived before the block reached the opening, such as the absolute size of the objects. In contrast, older infants looked longer at an obstructed passage of the block into the container, irrespective of the position of the screen.
Head and shoulders, knees and toes: Which parts of the body are necessary to be seen?
Authors: McGuigan Nicola , Doherty Martin J.
Published: October 2006

Children aged 2 and 3 years were tested for a previously neglected form of knowledge about visual perception; namely, whether an observer can see a figure that is partially occluded. The results indicate that for children of this age the visibility of a figure's face is crucial for judging visibility, whereas the visibility of the legs is not. This phenomenon is limited to human‐like figures. Results are explained in terms of engagement, a precursor to a mature understanding of attention.
Mental playmates: Siblings, executive functioning and theory of mind
Authors: McAlister Anna , Peterson Candida C.
Published: October 2006

This study assessed the theory of mind (ToM) and executive functioning (EF) abilities of 124 typically developing preschool children aged 3 to 5 years in relation to whether or not they had a child‐aged sibling (i.e. a child aged 1 to 12 years) at home with whom to play and converse. On a ToM battery that included tests of false belief, appearance‐reality (AR) and pretend representation, children who had at least 1 child‐aged sibling scored significantly higher than both only children and those whose only siblings were infants or adults. The numbers of child‐aged siblings in preschoolers' families positively predicted their scores on both a ToM battery (4 tasks) and an EF battery (2 tasks), and these associations remained significant with language ability partialled out. Results of a hierarchical multiple regression analysis revealed that independent contributions to individual differences in ToM were made by language ability, EF skill and having a child‐aged sibling. However, even though some conditions for mediation were met, there was no statistically reliable evidence that EF skills mediated the advantage of presence of child‐aged siblings for ToM performance. While consistent with the theory that distinctively childish interaction among siblings accelerates the growth of both ToM and EF capacities, alternative evidence and alternative theoretical interpretations for the findings were also considered.
The development of the picture‐superiority effect
Authors: Whitehouse Andrew J. O. , Maybery Murray T. , Durkin Kevin
Published: October 2006

When pictures and words are presented serially in an explicit memory task, recall of the pictures is superior. While this effect is well established in the adult population, little is known of the development of this picture‐superiority effect in typical development. This task was administered to 80 participants from middle childhood to adolescence. The magnitude of the picture superiority effect increased with age. This finding is interpreted as supporting the position that pictorial superiority is contingent upon the encoding of pictorial information through two different routes.
The role of social‐cognitive abilities in preschoolers' aggressive behaviour
Authors: Werner Rebecca Stetson , Cassidy Kimberly Wright , Juliano Mariel
Published: October 2006

This study investigated the relationship between preschool children's social‐cognitive abilities (theory of mind and social information processing; SIP) and their observed physical and relational aggressive behaviour. Children with more advanced social‐cognitive abilities engaged in fewer acts of physical aggression; however, much of the ability of the social‐cognitive variables to predict physical aggression was shared with language ability. In addition, social‐cognitive understanding moderated the connection between language ability and physical aggression. Exploratory examination of gender differences in patterns of association between physical aggression and the social cognitive understanding variables revealed that the relationships were only true for boys. Relational aggression was not associated with social cognitive ability for either boys or girls, but this is likely due to the low frequency of relationally aggressive behaviour observed in this sample.
Definitions of bullying: Age differences in understanding of the term, and the role of experience
Authors: Monks Claire P. , Smith Peter K.
Published: October 2006

We report two studies that examine age differences in pupils' and parents' definitions of the term bullying, and possible reasons for these including the role of specific experiences. Study 1 compared definitions of bullying given by participants in four age groups; 4 to 6 years, 8 years, 14 years and adult. Participants were shown/read 17 different cartoon scenarios and were asked if each constituted an episode of bullying or not. Multidimensional scaling indicated that the groups differed in their definition of bullying. 4‐ to 6‐year‐olds and 8‐year‐olds used 1 dimension, a distinction between aggressive and non‐aggressive acts, when differentiating cartoons; 14‐year‐olds and adults gave a 2‐dimensional solution, also distinguishing between physical and non‐physical (social/relational or verbal) acts. Study 2 further investigated definitions of bullying given by 99 children aged 4 to 6 years, and the role of experience. Just over half had some understanding of the term, but tended to be less concerned about power differences and repetition of actions. No significant differences in definitions were found between boys and girls, or between children in involved (aggressor, victim or defender) or not involved (bystander) roles; however, aggressors were more likely than other children to say that 11 of the 13 aggressive behaviours were not bullying. These findings are discussed in relation to age related changes in experiences of bullying and cognitive development. Implications for interventions and research are also raised.
Maintaining Lane Position with Peripheral Vision during In-Vehicle Tasks
Authors: Summala Heikki , Nieminen Tapio , Punto Maaret
Published: October 2006

Much research on driver attention, including evaluations of in-car equipment, at least implicitly assumes that attention is where the gaze is. Research on the dynamics of visual attention, however, suggests that drivers may use peripheral vision and that they learn its use over time, depending on the task demands and eccentricity. To investigate effects of task load and position on lane keeping, 11 novices and 16 experienced drivers were asked to drive along a straight road using only peripheral vision for lane keeping while doing another task foveally. The task varied in position and in mental load, with two difficulty levels in each of two different tasks. In the visual attention tasks, position had a clearly different effect on lane-keeping performance among novices and the experienced, as measured by the distance covered before crossing a lane boundary. Novices' performance deteriorated with the foveal task at near periphery at the speedometer level, whereas the performance of experienced drivers dropped only when the foveal task was down in the middle console. The result supports the hypothesis that novices need foveal vision at first for lane keeping but, with increasing practice, learn to manage with more peripheral vision. In the arithmetic tasks, however, no consistent experience-dependent task position effects occurred. Different results obtained for different tasks imply that when evaluating in-car facilities, the task characteristics and the respective resource allocation needed should be taken into account.
Cervical Spine and Temporomandibular Joint Arthritis in a Child With Kawasaki Disease
Authors: Jen Melinda , Brucia Lauren A. , Pollock Avrum N. , Burnham Jon M.
Published: October 2006

Severe neck pain, stiffness, and torticollis in a child with Kawasaki disease commonly represent aseptic meningitis or lymphadenitis. Here we present an unusual case of severe cervical spine and bilateral temporomandibular joint arthritis in a 5-year-old boy with a relapse of Kawasaki disease and coronary artery ectasia. The patient had a favorable response to a second course of intravenous immunoglobulin G and indomethacin therapy, with complete resolution of his symptoms.
Induced Velopharyngeal Fatigue Effects in Speakers with Repaired Palatal Clefts
Authors: Moon Jerald B. , Kuehn David P. , Chan Grace , Zhao Lili
Published: October 2006

Objective:

To address whether speakers with cleft palate exhibit velopharyngeal mechanism fatigue and are more susceptible to muscle fatigue than are speakers without cleft palate.

Methods:

Six adults with repaired palatal clefts and mild-moderate hypernasality served as subjects. Velopharyngeal closure force and levator veli palatini muscle activity were recorded. Subjects were asked to repeat /si/ 100 times while an external load consisting of air pressure (0, 5, 15, 25, 35 cm H2O) was applied via a mask to the nasal side of the velopharyngeal mechanism. Fatigue was defined as a reduction in velopharyngeal closure force across the series of /si/ productions, as evidenced by a negatively sloped regression line fit to the closure force data.

Results:

Absolute levels of velopharyngeal closure force were much lower than those observed previously in speakers without palatal clefts. All subjects showed evidence of fatigue. Furthermore, all subjects demonstrated exhaustion, where they were unable to close the velopharyngeal port against the nasal pressure load. This occurred at pressure load levels lower than those successfully completed by speakers without cleft palate.

Conclusions:

In speakers with a repaired palatal cleft, the velopharyngeal closure muscles may not possess the same strength and/or endurance as in normal speakers. Alternatively, muscles may possess adequate strength, but not be positioned optimally within the velopharynx following cleft palate repair or may be forced to move velopharyngeal structures that are stiffer as a result of surgical scarring.
High‐accuracy system for spectral measurement of small‐area‐contrast and low‐light‐level display screens
Authors: Fatadin Irshaad , Wall Christine , Vassie Ken
Published: October 2006

Abstract— A double‐monochromator spectroradiometer with a photon‐counting detector will be described. The system captures spectroradiometric data with near‐perfect linearity over six decades of intensity and with wavelength uncertainties of under 0.05 nm. It enables accurate measurement of spectral radiance data and small‐area contrast with an uncertainty less than 0.002 in chromaticity (x,y) and 2% in luminance for a typical CRT spectrum.
Spectral characterization and color correction of display colorimeters
Authors: Baribeau Réjean
Published: October 2006

Abstract— Tristimulus colorimeters commit systematic errors due to their imperfect realization of the CIE color‐matching functions. A method is proposed to characterize display colorimeters in a single session using a monochromator independently of any display. Colorimeter spectral responsivity functions are obtained that then serve to predict correction matrices for all the possible displays. Experiments show that this can be done with sufficient accuracy to meet practical requirements.
Net Shape Reaction Bonded Ceramic Micro Parts by Mechanical Microstructuring
Authors: Ritzhaupt‐Kleissl H.‐J. , Binder J. R. , Gietzelt T. , Kotschenreuther J.
Published: October 2006

Net shape ceramic micro components can be realized by mechanical microstructuring green blanks consisting of precursor materials followed by reaction bonding. The precursor material is composed of mainly zirconium silicide as reactive precursor material, organosilicon polymer (PMSS) as low loss binder and zirconium oxide as an inert phase. Shaping in the green state can easily be performed by micro milling, even if different cutting strategies are applied. Subsequently the components are thermally processed for ceramization and for sintering them to full density. Dependent on the material composition and on the green density the dimensions of the sintered components are retained unchanged compared to the dimensions of the green parts.
Rapid Manufacturing Metal Parts by Laser Sintering Admixture of Epoxy Resin/Iron Powders
Authors: Liu J. H. , Shi Y. S. , Lu Z. L. , Xu Y. , Huang S. H.
Published: October 2006

This paper presents an epoxy resin/iron powders admixture for indirect selective laser sintering process. The properties and sintering process of the admixture are discussed. The post processes of the green parts composed of the admixture, including decomposition, high temperature sintering and infiltration of bronze are also investigated. The results show that it is feasible to manufacture metal parts via indirect selective laser sintering process by using epoxy resin/Fe powders admixture.
Corrosion Behavior of AZ91D and AJ62x Magnesium Alloys in Chloride Media
Authors: Zhang W. , Jin S. , Ghali E. , Tremblay R. , Shehata M. , Es‐Sadiqi E.
Published: October 2006

Corrosion properties of AJ62x die cast and AZ91D die cast and thixocast magnesium alloys were studied in 0.014 M and 0.05M NaCl solutions using scanning reference electrode technique (SRET) and potentiodynamic polarization measurements. The overall SRET data were used to reproduce a three‐dimensional image mapping of the surface potential over the specimen. Referring to the typical 3‐D image map, the down cones (↓) correspond to anodic potentials (inside pits) and the up cones (↑) represent the cathodic potentials.
Phase‐Modulated Hierarchical Surface Structures by Interfering Laser Beams
Authors: Daniel C. , Dahotre N. B.
Published: October 2006

A high‐energy laser interference direct modulation technique is proposed to develop surfaces for energy‐efficient performance based on microstructure and physical parameter control. By producing the surface features or particles at the nano to micron scale in an orderly and/or parallel manner with a lateral long‐range order, the surfaces can be configured for highly improved surface response for a host of properties, including wear and friction. Laser interference direct modulation can lead to an optimized composite of metallurgical (localized alloyed or composite regions) and topographic textures. The technique is rapid prototyping, low cost and one‐step method that can be well‐integrated into existing production lines without the need for any special atmosphere. It is usable for complex geometries of the components and the surface can be modulated for nano‐micro scale features on large areas. The present paper describes the principle behind the laser interference technique configured for surface modulation and provides the definitions of surface structures (features) evolved. Some examples of laser‐based surface modulation of materials systems are presented.
Synthesis and Phase Transformations of Beta Metastable Ti‐Based Alloys Containing Biocompatible Ta, Mo and Fe Beta‐Stabilizer Elements
Authors: Gloriant T. , Texier G. , Prima F. , Laillé D. , Gordin D.‐M. , Thibon I. , Ansel D.
Published: October 2006

New beta‐metastable Ti alloys containing Ta, Mo and Fe biocompatible elements were synthesized by arc melting and then quenched in water from the beta phase field. For each alloy, the beta‐metastable phase decomposition was characterized by electric resistivity measurements and differential scanning calorimetry upon heating from room temperature to the beta transus. The formation of omega and alpha nanophases was detected and observed and the different phase transitions behavior was discussed in connection with the beta‐stabilizer content in each alloy.
New Metallic Glass/Alloy (MeGA) Rods Produced by Co‐extrusion
Authors: Gravier S. , Puech S. , Blandin J.‐J. , Suéry M.
Published: October 2006

New Metallic Glass/Alloy (MEGA)‐rods with a core in bulk metallic glass (zirconium or magnesium based BMG) and a sleeve in conventional light alloys (Al‐5056 and Mg‐AZ31) have been elaborated by co‐extrusion carried out at temperatures corresponding to the supercooled liquid region of the glass. For most glass/alloy combinations, this process leads to defect‐free interfaces and therefore to good compressive strengths which can be described by the rule of mixtures.
Barrier Properties of Poly(benzimidazole)‐Layered Silicates Nanocomposite Materials
Authors: Karthikeyan C. S. , Nunes S. P. , Schulte K.
Published: October 2006

Two‐layered lamella model for polymer layered silicates nanocomposite material processed by solution casting. The model describes the decrease in liquid permeability due to the presence of layered silicates, where each lamella has two layers: one of polymer and the second one containing polymer plus flakes. Diffusion of the liquid permeate first occurs through the layer of only polymer and then occurs through the second layer by wiggling around the flakes.
Nanoindentation Characterization of Sub‐Micrometric Y‐TZP Ceramics
Authors: Guicciardi S. , Shimozono T. , Pezzotti G.
Published: October 2006

The hardness and the Young's modulus of three zirconia ceramics with different mean grain size have been measured by depth‐sensing indentation tests at several peak loads. The grain size dependence of the mechanical properties was pointed out. Both loading and unloading curves were statistically analyzed.
Cover Picture: Two‐Dimensional Rectangular and Three‐Dimensional Rhombic Grids Created by Self‐Organization of Random Nanoextrusions (Adv. Eng. Mater. 10/2006)
Authors: Gordienko Y. G. , Gontareva R. G. , Schreiber J. S. , Zasimchuk E. E. , Zasimchuk I. K.
Published: October 2006

Nanoextrusions on single crystalline Al and Al‐Mg plates under constrained cyclic tension evolve to regular 2D surface rectangular grids and 3D porous rhombic grids. The cover shows AFM images of the plates along with their 3D reconstructions and associated digital Fourier transforms. More about this type of self‐organization can be found in the paper by Y. G. Gordienko et al. on page 957.
Utility of multiple chemical techniques in archaeological residential mobility studies: Case studies from Tiwanaku‐ and Chiribaya‐affiliated sites in the Andes
Authors: Knudson Kelly J. , Price T. Douglas
Published: October 2006

In the south central Andes, archaeologists have long debated the extent of Tiwanaku colonization during the Middle Horizon (AD 500–1000). We tested the hypotheses regarding the nature of Tiwanaku influence using strontium isotope, trace element concentration, and oxygen isotope data from archaeological human tooth enamel and bone from Tiwanaku‐ and Chiribaya‐affiliated sites in the south central Andes. Strontium isotope analysis of 25 individuals buried at the Tiwanaku‐affiliated Moquegua Valley site of Chen Chen demonstrates that it was likely a Tiwanaku colony. In contrast, no immigrants from the Lake Titicaca Basin were present in 27 individuals analyzed from the San Pedro de Atacama cemeteries of Coyo Oriental, Coyo‐3, and Solcor‐3; it is likely that these sites represent economic and religious alliances, but not colonies. However, strontium isotope analysis alone cannot distinguish movement between the Tiwanaku‐ and Chiribaya‐affiliated sites in the Moquegua and Ilo Valleys of southern Peru. Analyzing oxygen isotope and trace element concentration data and comparing it with strontium isotope data from the same individuals provides a more detailed picture of residential mobility in the Tiwanaku and Chiribaya polities. In addition to monitoring diagenetic contamination, trace element concentration data identified movement during adulthood for certain individuals. However, these data could not distinguish movement between the Moquegua and Ilo Valleys. While oxygen isotope data could clearly distinguish the high‐altitude sites from others, more data is needed to characterize the local oxygen isotope ratios of these regions. These data demonstrate the potential for archaeological reconstruction of residential mobility through multiple lines of evidence. Am J Phys Anthropol, 2006. © 2006 Wiley‐Liss, Inc.
New procedure to calculate the Hansen solubility parameters of polymers
Authors: Gharagheizi Farhad
Published: October 2006

The simplest experimental method to determine the Hansen solubility parameters (HSPs) for a polymer is to evaluate whether or not it dissolves in selected solvents. Those solvents dissolving the polymer will have HSPs closer to those of the polymer than those that do not. A computer program or graphical method can then be used to find the HSP for the polymer. In this work, an improved method for calculating the HSP of polymers, based on the Nelder–Mead optimization algorithm, is presented. The results of this program fit the data very well. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 31–36, 2007
Photopolymerization of a novel tetraoxaspiroundecane and silicon‐containing oxiranes
Authors: Chappelow Cecil C. , Pinzino Charles S. , Chen Shin‐Shi , Jeang Li , Eick J. David
Published: October 2006

New multifunctional silorane‐based systems were investigated, with respect to their photoreactivity, as potential matrix resins for low‐shrinkage/stress dental composites. The objective of this investigation was to synthesize and evaluate the reactivity of a silicon‐analogue oxaspirocyclic monomer with silorane‐based matrix resin systems during visible‐light polymerization. The experimental formulations contained (1) a silicon‐containing 1,5,7,11‐tetraoxaspiro[5.5]undecane (TOSU–IV), (2) a phenylmethylsilane containing two cyclohexyloxiranyl groups, (3) a cyclotetrasiloxane containing four cyclohexyloxiranyl groups, and (4) a photocationic initiator system. Three main aspects were studied: (1) the photoreactivity of the tetraoxaspiroundecane (TOSU)/silorane reactant mixtures with differential scanning photocalorimetry, (2) oxirane ring‐opening reactions of siloranes during binary photopolymerization with Fourier transform infrared (FTIR), and (3) oxaspirocyclic ring‐opening reactions of the TOSU reactant during homophotopolymerization and binary photopolymerization with FTIR and NMR. A diallyl ether precursor of TOSU–IV was also included in selected studies. The main findings were as follows: (1) a feasible route for the successful synthesis of a silicon analogue (TOSU–IV) was developed; (2) TOSU–IV was compatible and photoreactive, making possible the reduction of polymerization stress in silorane‐based matrix resins; and (3) spectroscopic evidence for both oxirane and oxaspirocyclic ring opening during the visible‐light photopolymerization of the test formulations was found. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 336–344, 2007