bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attitude control in walking hexapod robots: an analogic spatio‐temporal approach
Authors: Arena Paolo , Fortuna Luigi , Frasca Mattia 
Published: August 2002

AbstractIn this paper, the control system of a biologically inspired walking robot is presented. An analog distributed system acts as Central Pattern Generator for the locomotion control, while the attitude control is performed by using a proportional integrative controller for each leg. The inclusion of a saturation block in the attitude control scheme allows to take into account the joint limits, leading to the formulation of a cellular non‐linear network (CNN) based attitude controller. Thus, the whole control system can be structured as an analog control system realized by CNNs generating the locomotion pattern as a function of the sensorial stimuli from the environment. Both the network design and circuit realization are presented in this paper. Some experimental results obtained with the 18 degrees‐of‐freedom walking robot prototype are also reported. Moreover, some interesting experiments showing the robot capabilities to escape from unforeseen situations, in which overloading causes the saturation of a joint motor, are emphasized as an emerging result due to the action on both the locomotion control and the attitude control. Copyright © 2002 John Wiley & Sons, Ltd.
Queuing analysis of shared‐buffer ATM switches with grouped output channels
Authors: Abonamah Abdullah A. , Dang X.‐H. 
Published: August 2002

AbstractShared buffering and channel grouping are powerful techniques with great benefits in terms of both performance and implementation. Shared‐buffer switches are known to have better performance and better utilization than input or output queued switches. With channel grouping, a cell is routed to a group of channels instead of a specific output channel. In this way, congestion due to output contention can be minimized and the switch performance can therefore be greatly improved. Although each technique is well known by itself in the traditional study of queuing systems, their combined use in ATM networks has not been much explored previously. In this paper, we develop an analytical model for a shared‐buffer ATM switch with grouped output channels. The model is then used to study the switch performance in terms of cell loss probability, cell delay and throughput. In particular, we study the impact of the channel grouping factor on the buffer requirements. Our results show that grouping the output channels in a shared‐buffer ATM switch leads to considerable savings in buffer space. Copyright © 2001 John Wiley & Sons, Ltd.
Normalization of propagation measurements with respect to terrain effect
Authors: Alexandridis A. A. , Lazarakis F. , Dangakis K. , Kostarakis P. , Kourtis A. 
Published: August 2002

AbstractIn this paper, we introduce a method for the reliable modelling of propagation loss using measurements data. Using point to point effective height calculation, we apply a methodology for the normalization of signal propagation loss measurements with respect to terrain effect. Moreover, by applying the proposed normalization methodology on two different measurement data sets, taken in the same urban environment (Athens, Greece), it is experimentally proved that the effective height is accurately expressing the influence of terrain morphology in the vicinity of mobile unit on signal variability. Copyright © 2001 John Wiley & Sons, Ltd.
Performance analysis under dynamic loading of wavelength continuous and non‐continuous WDM networks with shortest‐path routing
Authors: Shen Gangxiang , Bose Sanjay K. , Cheng Tee Hiang , Lu Chao , Chai Teck Yoong 
Published: August 2002

AbstractThe performance of WDM networks using shortest path routing is studied under wavelength continuous (WC) and non‐continuous (NWC) constraints and dynamic traffic loading. Approximate analytical models are presented for the performance studies of such systems. Results of numerical calculations based on these models and simulations are given for different network topologies for the purposes of comparison. These analytical and simulation results are used to study the performance of these WDM networks under dynamic traffic loading. Copyright © 2001 John Wiley & Sons, Ltd.
Active versus latent representations: A neural network model of perseveration, dissociation, and decalage
Authors: Morton J. Bruce , Munakata Yuko 
Published: August 2002

AbstractChildren of different ages often perseverate, repeating previous behaviors when they are no longer appropriate, despite appearing to know what they should be doing. Using neural network models, we explore an account of these phenomena based on a distinction between active memory (subserved by the prefrontal cortex) and latent memory (subserved by posterior cortex). The models demonstrate how (a) perseveration occurs when an active memory of currently relevant knowledge is insufficiently strong to overcome a latent bias established by previous experience, (b) apparent dissociations between children's knowledge and action may reflect differences in the amount of conflict between active and latent memories that children need to resolve in the tasks, and (c) differences in when children master formally similar tasks (decalage) may result from differences in the strength of children's initial biases. The models help to clarify how prefrontal development may lead to advances in flexible thinking. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 255–265, 2002. DOI 10.1002/dev.10033
Heparan sulfate proteoglycans in experimental models of diabetes: a role for perlecan in diabetes complications
Authors: Conde‐Knape Karin 
Published: August 2002

AbstractProteoglycans are ubiquitous extracellular proteins that serve a variety of functions throughout the organism. Unlike other glycoproteins, proteoglycans are classified based on the structure of the glycosaminoglycan carbohydrate chains, not the core proteins. Perlecan, a member of the heparan sulfate proteoglycan (HSPG) family, has been implicated in many complications of diabetes. Decreased levels of perlecan have been observed in the kidney and in other organs, both in patients with diabetes and in animal models. Perlecan has an important role in the maintenance of the glomerular filtration barrier. Decreased perlecan in the glomerular basement membrane has a central role in the development of diabetic albuminuria. The involvement of this proteoglycan in diabetic complications and the possible mechanisms underlying such a role have been addressed using a variety of models. Due to the importance of nephropathy among diabetic patients most of the studies conducted so far relate to diabetes effects on perlecan in different types of kidney cells. The various diabetic models used have provided information on some of the mechanisms underlying perlecan's role in diabetes as well as on possible factors affecting its regulation. However, many other aspects of perlecan metabolism still await full elucidation.The present review provides a description of the models that have been used to study HSPG and in particular perlecan metabolism in diabetes and some of the factors that have been found to be important in the regulation of perlecan. Copyright © 2001 John Wiley & Sons, Ltd.
Region‐ and stage‐specific effects of FGFs and BMPs in chick mandibular morphogenesis
Authors: Mina Mina , Wang Yu‐Hsing , Ivanisevic Ana‐Maria , Upholt William B. , Rodgers Barbara 
Published: August 2002

AbstractThe mandibular processes are specified as at least two independent functional regions: two large lateral regions where morphogenesis is dependent on fibroblast growth factor (FGF)‐8 signaling, and a small medial region where morphogenesis is independent of FGF‐8 signaling. To gain insight into signaling pathways that may be involved in morphogenesis of the medial region, we have examined the roles of pathways regulated by FGFs and bone morphogenetic proteins (BMPs) in morphogenesis of the medial and lateral regions of the developing chick mandible. Our results show that, unlike in the lateral region, the proliferation and growth of the mesenchyme in the medial region is dependent on signals derived from the overlying epithelium. We also show that medial and lateral mandibular mesenchyme respond differently to exogenous FGFs and BMPs. FGF‐2 and FGF‐4 can mimic many of the effects of mandibular epithelium from the medial region, including supporting the expression of Msx genes, outgrowth of the mandibular processes and elongation of Meckel's cartilage. On the other hand, laterally placed FGF beads did not induce ectopic expression of Msx genes and did not affect the growth of the mandibular processes. These functional studies, together with our tissue distribution studies, suggest that FGF‐mediated signaling (other than FGF‐8), through interactions with FGF receptor‐2 and downstream target genes including Msx genes, is part of the signaling pathway that mediates the growth‐promoting interactions in the medial region of the developing mandible. Our observations also suggest that BMPs play multiple stage‐ and region‐specific roles in mandibular morphogenesis. In this study, we show that exogenous BMP‐7 applied to the lateral region at early stages of development (stage 20) caused apoptosis, ectopic expression of Msx genes, and inhibited outgrowth of the mandibular processes and the formation of Meckel's cartilage. Our additional experiments suggest that the differences between the effects of BMP‐7 on lateral mandibular mesenchyme at stage 20 and previously reported results at stage 23 (Wang et al., [1999] Dev. Dyn. 216:320–335) are related to differences in stages of differentiation in that BMP‐7 promotes apoptosis in undifferentiated lateral mandibular mesenchyme, whereas it promotes chondrogenesis at later stages of development. We also showed that, unlike mandibular epithelium and medially placed FGF beads, medially placed BMP‐7 did not support outgrowth of the isolated mesenchyme and at stage 20 induced the formation of a duplicated rod of cartilage extending from the body of Meckel's cartilage. These observations suggest that BMPs do not play essential roles in growth‐promoting interactions in the medial region of the developing mandible. However, BMP‐mediated signaling is a part of the signaling pathways regulating chondrogenesis of the mandibular mesenchyme. © 2002 Wiley‐Liss, Inc.
Matrix metalloproteinases mediate the dismantling of mesenchymal structures in the tadpole tail during thyroid hormone‐induced tail resorption
Authors: Jung Jae‐Chang , Leco Kevin J. , Edwards Dylan R. , Fini M. Elizabeth 
Published: August 2002

AbstractIt has been suggested that a family of tissue remodelling enzymes called matrix metalloproteinases (MMPs) play a causal role in the process of tail resorption during thyroid hormone‐induced metamorphosis of the anuran tadpole; however, this hypothesis has never been directly substantiated. We cloned two new Xenopus MMPs, gelatinase A (MMP‐2) and MT3‐MMP (MMP‐16), and the MMP inhibitor TIMP‐2. These clones were used along with several others to perform a comprehensive expression study. We show that all MMPs and TIMP‐2 are dramatically induced in the resorbing tail during spontaneous metamorphosis and are spatially coexpressed, primarily in the remodelling mesenchymal tissues. By Northern blotting, we show that all the examined MMPs/TIMP‐2 are also induced by treatment of organ‐cultured tails with thyroid hormone (T3). Using the organ culture model, we provide the first direct evidence that MMPs are required for T3‐induced tail resorption by showing that a synthetic inhibitor of MMP activity/expression can specifically retard the resorption process. By gelatin zymography, we also show T3 induction of a fifth MMP, preliminarily identified as gelatinase B (GelB; MMP‐9). Moreover, T3 not only induces MMP/TIMP expression but also MMP activation, and we provide evidence that TIMP‐2 participates in the latter process. These findings suggest that MMPs and TIMPs act in concert to effect the dismantling of mesenchymal structures during T3‐induced metamorphic tadpole tail resorption. © 2002 Wiley‐Liss, Inc.
Mouse PeP: A novel peroxisomal protein linked to myoblast differentiation and development
Authors: Ferrer‐Martínez Andreu , Ruiz‐Lozano Pilar , Chien Kenneth R. 
Published: August 2002

AbstractThe identification of several peroxisomal proteins in the past decade has deepened our understanding of the biology of peroxisomes and their involvement in human disorders. We report the cloning and expression pattern during the mouse development of a cDNA encoding a novel protein, named PeP, and show that its product is imported specifically to the peroxisome matrix in a variety of cell types. We also demonstrate that PeP is imported to the organelle through the PEX5 receptor pathway, which indicates that the C‐terminal tripeptide SKI behaves as a type 1 peroxisomal targeting signal (PTS1). PeP expression is tightly regulated, as shown by Northern and in situ hybridization experiments. Thus during embryonic development in the mouse, PeP mRNA is detected almost exclusively in the skeletal muscle, whereas in adult mice, strong expression is also found in the heart and brain. In addition, PeP mRNA accumulation is induced after myoblast differentiation in vitro, when myotube formation is promoted. Sequence analysis reveals that PeP has no significant homology to any known protein, except for a short stretch of amino acids containing the fingerprint of the fibronectin type III superfamily, a domain present in proteins often related to molecular and cellular recognition and binding processes. Thus our data suggest a connection between the function of PeP and murine cell differentiation and development. © 2002 Wiley‐Liss, Inc.
Disruption of erythropoiesis by dioxin in the zebrafish
Authors: Belair Cassandra D. , Peterson Richard E. , Heideman Warren 
Published: August 2002

Abstract2,3,7,8‐Tetrachlorodibenzo‐p‐ dioxin (TCDD, or dioxin) causes early life stage mortality in a variety of fish species. We have used the zebrafish (Danio rerio) to study the cardiovascular effects of TCDD treatment over the time course of zebrafish development. Early TCDD exposure (6 ng/ml) starting at 4 hr postfertilization (hpf) produced reductions in blood flow and in the number of circulating erythrocytes. These defects were consistently observable by 72 hpf. However, these responses were not observed when TCDD exposure was delayed until 96 hpf or later. These results suggest a model in which TCDD interferes with cardiovascular and erythropoietic developmental processes that are normally completed by 96 hpf. This model is strengthened by the finding that TCDD exposure blocks the step in hematopoiesis in which developing zebrafish switch from the primitive phase to the definitive phase of erythropoiesis. We observed no effect of TCDD on the levels of circulating primitive erythrocytes before 72 hpf and the expression of markers for early hematopoiesis, GATA‐1 and GATA‐2. However, early TCDD exposure prevented the appearance of definitive phase erythrocytes. TCDD produced a small delay in the migration of blood cells expressing SCL from the intermediate cell mass to the dorsal mesentery and dorsal aorta. Despite the decrease in blood flow produced by TCDD, confocal microscopy of the trunk vasculature by using a Tie2/green fluorescence protein endothelial marker at 48, 60, 72, and 96 hpf of TCDD‐exposed (4 hpf) revealed no apparent defects in blood vessel structure. © 2001 Wiley‐Liss, Inc.
Evidence for implicit sequence learning in dyslexia
Authors: Kelly Steve W. , Griffiths Sarah , Frith Uta 
Published: August 2002

AbstractNicolson and Fawcett (Cognition 1990; 35: 159–182) have suggested that a deficit in the automatization of skill learning could account for the general impairments found in dyslexia. Much of the evidence for their claims has been collected via a dual task paradigm, which might allow for alternative explanations of the data. The present study examines automatic skill learning in a single task paradigm and extends previous studies by independently examining the contribution of stimulus‐based and response‐based learning. The task replicates Mayr's (J. Exp. Psychol.: Learning Memory Cognition 1996; 22: 350–364) methodology in the Serial Reaction Time task by exposing participants to two structured displays, simultaneously. Learning is measured by comparing RT to the learned sequence against RT to a random display. This study demonstrates learning for both dyslexic and control groups for a spatial sequence which was observed and a concurrent non‐spatial sequence which was responded to via a keypress. Learning of the sequence did not seem to depend on awareness of the sequence structure. These results suggest that automatic skill learning is intact in dyslexic individuals. Copyright © 2002 John Wiley & Sons, Ltd.
The media's representation of the ideal male body: A cause for muscle dysmorphia?
Authors: Leit Richard A. , Gray James J. , Pope Harrison G. 
Published: August 2002

AbstractObjectiveThis study sought to examine the effects of media images on men's attitudes toward their body appearance.MethodA group of college men viewed advertisements showing muscular men, whereas a control group viewed neutral advertisements. Immediately thereafter, participants performed a computerized test of body image perception while unaware of the hypotheses being tested in the study.ResultsThe students exposed to the muscular images showed a significantly greater discrepancy between their own perceived muscularity and the level of muscularity that they ideally wanted to have.DiscussionThese findings suggest that media images, even in a brief presentation, can affect men's views of their bodies. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 334–338, 2002; DOI 10.1002/eat.10019
The impact of body image experiences: Development of the body image quality of life inventory
Authors: Cash Thomas F. , Fleming Emily C. 
Published: August 2002

AbstractObjectiveSubstantial research confirms that body image affects multiple aspects of psychosocial functioning, yet there is no direct assessment to quantify its impact on an individual's quality of life.MethodIn the present study, the Body Image Quality of Life Inventory was developed and empirically evaluated with 116 college women.Results and DiscussionThis 19‐item assessment was internally consistent and stable over a 2‐ to 3week period. It converged significantly with multiple measures of body image evaluation and investment and with body mass. The results further revealed that women in the sample reported more positive than negative consequences of their body image for various domains of life. The implications of these findings and directions for continued validation of this unique measure are considered. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 455–460, 2002
Homosexuality as a specific risk factor for eating disorders in men
Authors: Russell Christopher J. , Keel Pamela K. 
Published: August 2002

AbstractObjectiveThe current study examined whether homosexuality is a specific risk factor for disordered eating in men.MethodMen (64 heterosexual and 58 homosexual) completed the Beck Depression Inventory (BDI), the Rosenberg Self‐Esteem Scale (RSE), the Masculinity and Femininity scales of the Bem Sex‐Role Inventory (BSRI), the Bulimia Test‐Revised (BULIT‐R), the Eating Attitudes Test (EAT‐26), and the Body Shape Questionnaire (BSQ).ResultsHomosexual men had more pathological scores on the BDI, RSE, BULIT‐R, EAT‐26, and BSQ. Additionally, homosexual men reported greater discomfort with sexual orientation. After controlling for differences in depression, self‐esteem, and comfort with sexual orientation, sexual orientation continued to account for significant variance in BULIT‐R, EAT‐26, and BSQ scores.DiscussionFuture research may benefit from exploring aspects of homosexuality that may contribute specifically to risk for disordered eating in men. © 2002 by Wiley Periodicals, Inc. Int J Eat Disord 31: 300–306, 2002; DOI 10.1002/eat.10036
A randomized trial of a dissonance‐based eating disorder prevention program
Authors: Stice Eric , Chase Allison , Stormer Susan , Appel Anne 
Published: August 2002

AbstractObjectiveAs psychoeducational eating disorder prevention programs have not been shown to reduce bulimic pathology, we developed and evaluated a dissonance‐based intervention for high‐risk populations.MethodYoung women (N = 87) with body image concerns were randomized to this intervention, which involves verbal, written, and behavioral exercises requiring them to critique the thin‐ideal, or to a healthy weight management control group. Participants completed a baseline, termination, and 4‐week follow‐up survey.ResultsParticipants in the dissonance intervention reported decreased thin‐ideal internalization, body dissatisfaction, dieting, negative affect, and bulimic symptoms at termination and at 4‐week follow‐up. Unexpectedly, participants in the healthy weight management control group also reported some benefits.DiscussionTaken in conjunction with past findings, these preliminary results suggest that the dissonance intervention, and to a lesser extent the healthy weight management intervention, may reduce bulimic pathology and risk factors for eating disturbances. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 247–262, 2001.
Sexual orientation and eating psychopathology: The role of masculinity and femininity
Authors: Meyer Caroline , Blissett Jackie , Oldfield Claire 
Published: August 2002

AbstractObjectivePrevious research suggests that eating disorders are related to homosexuality in men, although links with female sexual orientation are less clear. Appearance factors have generally been implicated in this relationship. However, previous studies have failed to consider the role of femininity, even though evidence suggests that this is a more critical factor than sexual preference. The aim of this study was to consider the relationship between gender‐role orientation and eating psychopathology in nonclinical men and women of different sexual orientations.MethodOne hundred university students (40 homosexual; 60 heterosexual) completed the Bem Sex Role Inventory and the Eating Attitudes Test.ResultsFor the group as a whole, there were links between femininity and high levels of eating psychopathology, whereas masculinity was associated with relatively healthy eating‐related attitudes and behaviors. When considering the role of sexual orientation, these links were specific to homosexual men and women.ConclusionsIn relation to homosexual men and women, the results support a model where femininity might be seen as a specific risk factor for eating disorders, whereas masculinity is likely to be a protective factor. Methodological and conceptual implications are discussed. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 314–318, 2001.
Body image in boys: A review of the literature
Authors: Cohane Geoffrey H. , Pope Harrison G. 
Published: August 2002

AbstractObjectiveBoth scientific research and popular attention have begun to focus on the neglected issue of body image in boys. We reviewed the findings of this emerging literature.MethodUsing computer and manual search techniques, we located 17 studies that assessed body image attitudes in boys under age 18.ResultsWe located 17 studies, most performed within the last 10 years. Eight studies used exclusively questionnaires or interviews; the rest also used figure drawings from which the subjects could choose specific images in answer to questions. Although boys generally displayed less overall body concern than girls, many boys of all ages reported dissatisfaction with their bodies, often associated with reduced self‐esteem. Whereas girls typically wanted to be thinner, boys frequently wanted to be bigger. However, most studies failed to distinguish between “bigness” due to increased muscle and that due to fat.ConclusionsBody image dissatisfaction in boys is common and often associated with distress. To better assess this phenomenon, future studies should take care to separate the indices of muscle and fat. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 373–379, 2001.