bluuebunny/crossref_metadata_2025 huggingface dataset:
Vessel-Specific Toll-Like Receptor Profiles in Human Medium and Large Arteries
Authors: Pryshchep Olga , Ma-Krupa Wei , Younge Brian R. , Goronzy Jörg J. , Weyand Cornelia M.
Published: September 2008

Background—

Inflammatory vasculopathies, ranging from the vasculitides (Takayasu arteritis, giant cell arteritis, and polyarteritis nodosa) to atherosclerosis, display remarkable target tissue tropisms for selected vascular beds. Molecular mechanisms directing wall inflammation to restricted anatomic sites within the vascular tree are not understood. We have examined the ability of 6 different human macrovessels (aorta and subclavian, carotid, mesenteric, iliac, and temporal arteries) to initiate innate and adaptive immune responses by comparing pathogen-sensing and T-cell–stimulatory capacities.

Methods and Results—

Gene expression analysis for pathogen-sensing Toll-like receptors (TLRs) 1 to 9 showed vessel-specific profiles, with TLR2 and TLR4 ubiquitously present, TLR7 and TLR9 infrequent, and TLR1, TLR3, TLR5, TLR6, and TLR8 expressed in selective patterns. Experiments with vessel walls stripped of the intimal or adventitial layer identified dendritic cells at the media-adventitia junction as the dominant pathogen sensors. In human artery–severe combined immunodeficiency (SCID) mouse chimeras, adoptively transferred human T cells initiated vessel wall inflammation if wall-embedded dendritic cells were conditioned with TLR ligands. Wall-infiltrating T cells displayed vessel-specific activation profiles with differential production of CD40L, lymphotoxin-α, and interferon-γ. Vascular bed–specific TLR fingerprints were functionally relevant, as exemplified by differential responsiveness of iliac and subclavian vessels to TLR5 but not TLR4 ligands.

Conclusions—

Populated by indigenous dendritic cells, medium and large human arteries have immune-sensing and T-cell–stimulatory functions. Each vessel in the macrovascular tree exhibits a distinct TLR profile and supports selective T-cell responses, imposing vessel-specific risk for inflammatory vasculopathies.
Immediate Postnatal Growth Is Associated With Blood Pressure in Young Adulthood
Authors: Ben-Shlomo Yoav , McCarthy Anne , Hughes Rachael , Tilling Kate , Davies David , Davey Smith George
Published: September 2008

There is a consistent inverse association between birth weight and systolic blood pressure; however, few studies have been able to examine the immediate postnatal period. We have examined whether accelerated postnatal growth predicts adult systolic and diastolic blood pressure. We followed up participants from the Barry Caerphilly Growth Study. Blood pressure data were obtained on 679 of the original 951 subjects (73%) aged ≈25 years. Both multivariable linear regression and spline models were used to examine the association among weight, length, and growth velocities with systolic blood pressure and diastolic blood pressure. Both statistical approaches showed that birth weight was inversely associated with systolic blood pressure. Only the spline models found that immediate (0 to 5 months) weight gain (β coefficient: 1.29 mm Hg; 95% CI: 0.36 to 2.23;
P
=0.007) and weight gain between 1 year and 9 months to 5 years (β coefficient: 1.44 mm Hg; 95% CI: 0.31 to 2.57;
P
=0.01) were independently associated with systolic blood pressure, whereas only immediate weight gain (β coefficient: 0.74 mm Hg; 95% CI: 0.08 to 1.41;
P
=0.03) was associated with diastolic blood pressure. This is the first study to demonstrate that only immediate postnatal growth predicts diastolic blood pressure in term births, whereas it adds further evidence that both birth weight and postnatal growth are associated with systolic blood pressure in support of both the fetal origins and growth acceleration hypotheses.
White Matter Integrity Predicts Delay Discounting Behavior in 9- to 23-Year-Olds: A Diffusion Tensor Imaging Study
Authors: Olson Elizabeth A. , Collins Paul F. , Hooper Catalina J. , Muetzel Ryan , Lim Kelvin O. , Luciana Monica
Published: September 2008

Healthy participants (n = 79), ages 9–23, completed a delay discounting task assessing the extent to which the value of a monetary reward declines as the delay to its receipt increases. Diffusion tensor imaging (DTI) was used to evaluate how individual differences in delay discounting relate to variation in fractional anisotropy (FA) and mean diffusivity (MD) within whole-brain white matter using voxel-based regressions. Given that rapid prefrontal lobe development is occurring during this age range and that functional imaging studies have implicated the prefrontal cortex in discounting behavior, we hypothesized that differences in FA and MD would be associated with alterations in the discounting rate. The analyses revealed a number of clusters where less impulsive performance on the delay discounting task was associated with higher FA and lower MD. The clusters were located primarily in bilateral frontal and temporal lobes and were localized within white matter tracts, including portions of the inferior and superior longitudinal fasciculi, anterior thalamic radiation, uncinate fasciculus, inferior fronto-occipital fasciculus, corticospinal tract, and splenium of the corpus callosum. FA increased and MD decreased with age in the majority of these regions. Some, but not all, of the discounting/DTI associations remained significant after controlling for age. Findings are discussed in terms of both developmental and age-independent effects of white matter organization on discounting behavior.
An ERP Investigation on Visuotactile Interactions in Peripersonal and Extrapersonal Space: Evidence for the Spatial Rule
Authors: Sambo Chiara F. , Forster Bettina
Published: September 2008

The spatial rule of multisensory integration holds that cross-modal stimuli presented from the same spatial location result in enhanced multisensory integration. The present study investigated whether processing within the somatosensory cortex reflects the strength of cross-modal visuotactile interactions depending on the spatial relationship between visual and tactile stimuli. Visual stimuli were task-irrelevant and were presented simultaneously with touch in peripersonal and extrapersonal space, in the same or opposite hemispace with respect to the tactile stimuli. Participants directed their attention to one of their hands to detect infrequent tactile target stimuli at that hand while ignoring tactile targets at the unattended hand, all tactile nontarget stimuli, and any visual stimuli. Enhancement of ERPs recorded over and close to the somatosensory cortex was present as early as 100 msec after onset of stimuli (i.e., overlapping with the P100 component) when visual stimuli were presented next to the site of tactile stimulation (i.e., perihand space) compared to when these were presented at different locations in peripersonal or extrapersonal space. Therefore, this study provides electrophysiological support for the spatial rule of visual–tactile interaction in human participants. Importantly, these early cross-modal spatial effects occurred regardless of the locus of attention. In addition, and in line with previous research, we found attentional modulations of somatosensory processing only to be present in the time range of the N140 component and for longer latencies with an enhanced negativity for tactile stimuli at attended compared to unattended locations. Taken together, the pattern of the results from this study suggests that visuotactile spatial effects on somatosensory processing occur prior and independent of tactile–spatial attention.
Cross-modal Emotional Attention: Emotional Voices Modulate Early Stages of Visual Processing
Authors: Brosch Tobias , Grandjean Didier , Sander David , Scherer Klaus R.
Published: September 2008

Emotional attention, the boosting of the processing of emotionally relevant stimuli, has, up to now, mainly been investigated within a sensory modality, for instance, by using emotional pictures to modulate visual attention. In real-life environments, however, humans typically encounter simultaneous input to several different senses, such as vision and audition. As multiple signals entering different channels might originate from a common, emotionally relevant source, the prioritization of emotional stimuli should be able to operate across modalities. In this study, we explored cross-modal emotional attention. Spatially localized utterances with emotional and neutral prosody served as cues for a visually presented target in a cross-modal dot-probe task. Participants were faster to respond to targets that appeared at the spatial location of emotional compared to neutral prosody. Event-related brain potentials revealed emotional modulation of early visual target processing at the level of the P1 component, with neural sources in the striate visual cortex being more active for targets that appeared at the spatial location of emotional compared to neutral prosody. These effects were not found using synthesized control sounds matched for mean fundamental frequency and amplitude envelope. These results show that emotional attention can operate across sensory modalities by boosting early sensory stages of processing, thus facilitating the multimodal assessment of emotionally relevant stimuli in the environment.
The Polis of `Global' Protest
Authors: Gorringe Hugo , Rosie Michael
Published: September 2008

Protests at recent international summit meetings have prompted assertions about `global protest' and `global civil society'. This article provides a detailed and contextualized analysis of the 2005 G8 summit in Scotland, focusing on the dynamic interplay between police and protestors. The authors argue that local variables were critical to the experience of this manifestation of `global protest'. Focusing on the policing of events in Edinburgh, they highlight the preconceptions and assumptions (frames) underpinning police operations and contribute to a more interactive understanding of police—protestor relations. Protest emerges in relation to the `polis' (simultaneously denoting both the political community and the police), and neglecting this relationship leads to incomplete analyses. In concluding, the authors consider the implications of their research for the policing of political protest.
Governing through Global Networks
Authors: Ilcan Suzan , Phillips Lynne
Published: September 2008

This article moves beyond the `network society' thesis to provide an analysis of select global organizations and their global knowledge networks in the field of development. Drawing on the work of contemporary theorists of governmentality, the authors argue that global knowledge networks facilitate the movement of knowledge across space and time, and adjoin particular principles as a means of governing. These networks operate as mobile technologies of government, and seek to manage the objects of development, prescribe proper conduct and cultivate active agents and citizens through participatory development activities. The authors' claims are based on extensive policy documents, reports, network-based development programmes affiliated with specific global organizations and interviews conducted with United Nations policy and research personnel.
Contexts of Anxiety
Authors: Schinkel Willem
Published: September 2008

This article analyses the attention given in the Netherlands to what is called `senseless violence' as an expression of the general idea that violence is growing, and as an example of a moral panic. It is argued that this is a combination of a grassroots and interest-group moral panic that has been carried along mainly by media and institutionalized civil initiatives. The production of this moral panic is illustrated, together with its consequences in the areas of politics, law and social science. It is argued that the moral panic over `senseless violence' is in many respects a `classic' example of a moral panic, but that it departs from this pattern in the sense that it is characterized by the conspicuous absence of moral deviants. Also, it is argued that the institutionalization of anxiety can cause a moral panic to persist for several years. In the case of `senseless violence', the moral panic emerged in 1997 and only very slowly decreased after 2003. The institutionalization of anxiety means that many institutional remnants of the moral panic linger on and affect contexts such as politics.
Pesticides in the Risk Society
Authors: Jensen Mette , Blok Anders
Published: September 2008

Ulrich Beck's diagnosis in his already classic book Risk Society addressed, when it was first published in 1986, a number of new and important issues concerning environment and society. In spite of the weight of the theoretical contributions of the book, it appears, however, somewhat unsubstantiated in empirical terms. Similarly, the `macroscopic' level of Beck's analysis often seems insensitive to variations in risk concerns within and between different countries, regions or localities. These interrelated characteristics of the risk society discussion serve as the background for the approach in this article: to discuss central theoretical propositions related to the risk society diagnosis by drawing on an empirical case study of the risk perception with regard to pesticides. Pesticides are by nature `designer toxins' and as such a `risky' technological development, detectable only by experts' `sense apparatus', and surrounded by expert disagreements, multiple interests and substantial media attention. In other words, this case study can be said to be `paradigmatic' and may hence have wider applicability within risk society debates. On this basis, the authors argue in particular that social processes of perceiving, of `viewing' and making sense of risk, are much more multifarious than allowed by the risk society framework.
Ideology, Magic and Spectres
Authors: Bergua Amores José Ángel
Published: September 2008

Aside from its economic and biological worth, water also has a symbolic or sociocultural value, which is a direct and immediate response to people's daily needs for drinking and household water. These are imposed by the hegemonic social class of our time, the bourgeoisie, abetted by science and technology. This article provides a genealogical analysis of the values attributed to water by the bourgeoisie, focusing on the social order that inspires them.
Factor Structure of Scores on the State Version of the Four Dimension Mood Scale
Authors: Gregg Vernon H. , Shepherd Alex J.
Published: September 2008

This study examines the factor structure of scores on the Four Dimension Mood Scale (4DMS) developed by Huelsman, Nemanick, and Munz in response to criticisms of the Positive and Negative Affect Schedule. The results showed that the factor structure of 4DMS scores obtained with a sample of U.K. residents assessed for state affect corresponded closely to that obtained by Huelsman et al. with hospital employees in the United States who were assessed for trait affect. The four-factor model provided a reasonably good fit to the scores and fitted better than one-factor or two-factor models, thus favoring a four-dimension model of affect. It was concluded that the 4DMS is appropriate for use in the United Kingdom with comparable samples. The study identified differences in composition of the 4DMS and Thayer's Activation Deactivation Adjective Check List, especially in the Tiredness scale, and areas for further investigation of the 4DMS.
Rasch Modeling of the Self-Deception Scale of the Balanced Inventory of Desirable Responding
Authors: Cervellione Kelly L. , Lee Young-Sun , Bonanno George A.
Published: September 2008

Self-deception has become a construct of great interest in individual differences research because it has been associated with levels of resilience and mental health. The Balanced Inventory of Desirable Responding (BIDR) is a self-report measure used for quantifying self-deception. In this study we used Rasch modeling to examine the properties of the self-deception scale of the BIDR in terms of dimensionality, use of response category, sample appropriateness, and reliability. A total of 315 university students (ages 18-21) were administered the self-deception scale of the BIDR. Seven-category and 2-category scoring methods were compared, as approved by the developers of the scale. Overall, the 7-category model was the best fit for the data and the sample. We concluded that the scale has the best reliability using a 7-category model with Item 13 deleted. Because of low person measure separation and reliability, the appropriateness of use of this instrument in undergraduate populations is questioned; the use of the measure in populations with larger ranges of self-deception is not recommended.
Applications of the Linear Logistic Test Model in Psychometric Research
Authors: Kubinger Klaus D.
Published: September 2008

The linear logistic test model (LLTM) breaks down the item parameter of the Rasch model as a linear combination of some hypothesized elementary parameters. Although the original purpose of applying the LLTM was primarily to generate test items with specified item difficulty, there are still many other potential applications, which may be of use for psychometric research on various testing conditions. This article provides some examples of such applications. The examples include (a) position effect of item presentation (in particular, learning and fatigue effects); (b) content-specific learning effect; (c) effect of speeded item presentation; and (d) effect of item response format.
A Two-Stage Scoring Method to Enhance Accuracy of Performance Level Classification
Authors: Finkelman Matthew , Darby Mark , Nering Michael
Published: September 2008

Many tests classify each examinee into one of multiple performance levels on the basis of a combination of multiple-choice (MC) and constructed-response (CR) items. This study introduces a two-stage scoring method that identifies examinees whose MC scores place them near a cut point, advising scorers on which examinees will be most affected by score discrepancies. The idea that additional attention be given to such examinees' CR responses is explored from both psychometric and practical perspectives. Because more precision is achieved for examinees near the cut points, the method has potential to enhance the percentage of examinees classified correctly. In an empirical investigation of two operational assessments, the two-stage scoring approach successfully predicted which examinees would ultimately attain scores near the border between two performance levels.
Using the Standardized Letters of Recommendation in Selection
Authors: Liu Ou Lydia , Minsky Jennifer , Ling Guangming , Kyllonen Patrick
Published: September 2008

In an effort to standardize academic application procedures, the authors developed the Standardized Letters of Recommendation (SLR) to capture important cognitive and noncognitive qualities of graduate school candidates. The SLR, which consists of seven scales, is applied to an intern-selection scenario. Both professor ratings (n = 414) during the application process and mentor ratings of the selected students (n = 51) are collected using the SLR. A multidimensional Rasch investigation suggests that the SLR displays satisfactory internal consistency, model fit, and item fit. The two cognitive scales, knowledge and analytical skills, are found to be the best predictors for intern selection. The professor ratings are systematically higher than the mentor ratings. Possible reasons for the rating discrepancies are discussed. Also, implications for how the SLR can be used and improved in other selection situations are suggested.
Measurement of Epistemological Beliefs
Authors: Ordoñez Xavier G. , Ponsoda Vicente , Abad Francisco J. , Romero Sonia J.
Published: September 2008

This article proposes a new test (called the EQEBI) for the measurement of epistemological beliefs, integrating and extending the Epistemological Questionnaire (EQ) and the Epistemic Beliefs Inventory (EBI). In Study 1, the two tests were translated and applied to a Spanish-speaking sample. A detailed dimensionality exploration, by means of the monotone homogeneity model and confirmatory factor analysis, provides unexpected dimensionality results. Therefore, a new test is proposed, and the dimensionality and psychometric properties of the test's scores are determined. The new test retains four of the five original dimensions. The EQEBI has 27 items, and its score reliability is higher than that of the original EQ and EBI. In Study 2, the EQEBI was applied to another sample to verify the psychometric properties of the obtained scores. The expected four unidimensional scales are confirmed. The scales are calibrated with the graded response model. Recommendations are offered for using the scales for epistemological beliefs assessment.
Psychometric Properties of the Scores on the Behavioral Inhibition and Activation Scales in a Sample of Norwegian Children
Authors: Bjørnebekk Gunnar
Published: September 2008

The primary aim of this study was to examine the psychometric properties of the scores on a version for children of the Carver and White Behavioral Inhibition and Activation scales (the BIS—BAS scales). This involved administering the BIS—BAS scales, the Positive and Negative Affect Schedule, the Junior Eysenck Personality Questionnaire Revised—Abbreviated, and the Achievement Motives Scale to a population of 661 Norwegian sixth graders. The findings reveal that the scores on the BIS—BAS scales for children have a theoretically meaningful factor structure as well as satisfactory convergent validity and reliability. However, the results indicate that the version for children of the BAS scale actually may consist of two subscales: one related to the experience of pleasurable affect and one to persistence in goal pursuit. To a large extent, the relationship with the other scales was as expected.
China as an Economic Power in the Contemporary Era of Globalization
Authors: Moore Thomas G.
Published: September 2008

China's rising profile in world economic affairs is beyond dispute. This article explores several ways to think about China's experience as a latecomer, offering a preliminary assessment of its development trajectory and the evolving nature of its foreign economic relations. In particular, the analysis rejects the view that China is emerging as the hub of a regional economic order in East Asia that is increasingly cohesive and independent vis-à-vis other regions of the world. Alternatively, the article highlights the promise of research that focuses on the role of Chinese economic activity within global commodity chains and how this particular form of cross-border integration affects interdependence among nation-states at multi-continental distances.
Long Shot and Short Hit
Authors: Lee Wei-chin
Published: September 2008

This article attempts to evaluate China's military developments in recent years and explore the implications of its military advancements. The emphasis will be on the potential impact of China's current military growth on the USA and Taiwan. What are the unique features of China's recent enhancement of its military capability? Does China's military expansion signal a power transition for a US-dominated international system? What is the US policy to deal with a rising China? Finally, to what extent is Taiwan prepared to meet China's new military challenges?
Domestic Sources of China's Emerging Grand Strategy
Authors: Guoli Liu
Published: September 2008

China's emerging grand strategy has deep domestic roots, which can be examined in terms of cultural tradition, socioeconomic development, and strategic choices. China's cultural tradition emphasizes he wei gui (priority to peace) and he er bu tong (unity in diversity). China's modernization demands a peaceful environment. In fact, the majority of Chinese elites and common people have realized that China cannot become rich and strong without a peaceful environment. Peaceful development is a strategic choice made by leaders from Deng Xiaoping to Hu Jintao. A rising China is facing cultural, economic, environmental, and political challenges. This study also highlights the difficulty of practicing China's emerging grand strategy.
ADHD and Method Variance
Authors: Konold Timothy R. , Glutting Joseph J.
Published: September 2008

This study employed a correlated trait—correlated method application of confirmatory factor analysis to disentangle trait and method variance from measures of attention-deficit/hyperactivity disorder obtained at the college level. The two trait factors were Diagnostic and Statistical Manual of Mental Disorders—Fourth Edition ( DSM—IV ) Inattention and DSM—IV Hyperactivity-Impulsivity. The two source factors were self-reports and parent-reports. Data were collected for an epidemiological sample ( N = 1,079) of college freshmen stratified for race/ethnicity, gender, and ability level according to national targets for the U.S. college population. Results revealed (a) parents' ratings were better measures of internalizing behavioral dimensions and that students' ratings were better measures of externalizing dimensions of behavior, (b) informants have a greater impact on behavior ratings than the behavioral construct that is presumed to be the primary cause of the behavior as measured by the CARE, (c) relationships among the method factors revealed a substantial amount of unique variance among informants, and (d) relationships among trait factors were largely within expectation.
Does Early Reading Failure Decrease Children's Reading Motivation?
Authors: Morgan Paul L. , Fuchs Douglas , Compton Donald L. , Cordray David S. , Fuchs Lynn S.
Published: September 2008

The authors used a pretest—posttest control group design with random assignment to evaluate whether early reading failure decreases children's motivation to practice reading. First, they investigated whether 60 first-grade children would report substantially different levels of interest in reading as a function of their relative success or failure in learning to read. Second, they evaluated whether increasing the word reading ability of 15 at-risk children would lead to gains in their motivation to read. Multivariate analyses of variance suggest marked differences in both motivation and reading practice between skilled and unskilled readers. However, bolstering at-risk children's word reading ability did not yield evidence of a causal relationship between early reading failure and decreased motivation to engage in reading activities. Instead, hierarchical regression analyses indicate a covarying relationship among early reading failure, poor motivation, and avoidance of reading.
Are Reading and Behavior Problems Risk Factors for Each Other?
Authors: Morgan Paul L. , Farkas George , Tufis Paula A. , Sperling Rayne A.
Published: September 2008

Two questions were investigated. First, are children with reading problems in first grade more likely to experience behavior problems in third grade? Second, are children with behavior problems in first grade more likely to experience reading problems in third grade? The authors explored both questions by using multilevel logistic regression modeling to analyze data from the Early Childhood Longitudinal Study—Kindergarten Class (ECLS-K). After statistically controlling for a wide range of potential confounds, they found that children with reading problems in first grade were significantly more likely to display poor task engagement, poor self-control, externalizing behavior problems, and internalizing behavior problems in third grade. They also found that children displaying poor task engagement in first grade were more likely to experience reading problems in third grade. Collectively, these findings suggest that the most effective types of interventions are likely to be those that target problems with reading and task-focused behaviors simultaneously.
Using Kindergarten Number Sense to Predict Calculation Fluency in Second Grade
Authors: Locuniak Maria N. , Jordan Nancy C.
Published: September 2008

Children's number sense in kindergarten was used to predict their calculation fluency in second grade ( N = 198). Using block entry regression, usual predictors of age, reading, memory, and verbal and spatial cognition were entered in the first block and number sense measures were added in the second block. Number sense measures contributed a significant amount of variance over and above the more general predictors (26%—42%). Uniquely predictive subareas were active memory for numbers, number knowledge, and number combinations, with number combinations standing out as the strongest single predictor. Number sense screening in kindergarten, using “at-risk” versus “not-at-risk” criteria, successfully ruled out 84% of the children who did not go on to have calculation fluency difficulties and positively identified 52% of the children who later showed fluency difficulties. The relation of early number skills to later calculation fluency has important implications for math screening and intervention.
Prevalence of Combined Reading and Arithmetic Disabilities
Authors: Dirks Evelien , Spyer Ginny , van Lieshout Ernest C. D. M. , de Sonneville Leo
Published: September 2008

This study assesses the prevalence of combined reading and arithmetic disabilities in 799 Dutch schoolchildren using st dardized school achievement tests. Scores of arithmetic, word recognition, reading comprehension, and spelling of child in fourth and fifth grade were used. The main interest involved the co-occurrence of word recognition and arithmetic d abilities because of their possible relationship. The authors find a percentage of 7.6 for combined reading and arithme disabilities. Reading disabilities and arithmetic disabilities co-occurred more often than expected based on rates of the s arate conditions. Children with combined reading and arithmetic disabilities seem to have more generalized achievem difficulties than single-deficit groups. Different operationalizations for reading disabilities (spelling and reading comp hension measures instead of word recognition) led, in part, to selection of other children. This might imply that differ processes underlie the relationship between arithmetic and word recognition disabilities compared to the relationship arithmetic disabilities with difficulties in spelling and reading comprehension.
Poor Performance on Serial Visual Tasks in Persons With Reading Disabilities
Authors: Ram-Tsur Ronit , Faust Miriam , Zivotofsky Ari Z.
Published: September 2008

The present study investigates the performance of persons with reading disabilities (PRD) on a variety of sequential visual-comparison tasks that have different working-memory requirements. In addition, mediating relationships between the sequential comparison process and attention and memory skills were looked for. Our findings suggest that PRD perform worse than normally achieving readers (NAR) when the task requires more than a minimal amount of working memory, unrelated to presentation rate. We also demonstrate high correlations between performance on the task with the most working-memory demands and reading-related skills, suggesting that poor working-memory abilities may be one of the underlying mechanisms of dyslexia. The mediating model analysis indicates that order judgment tasks are mediating to verbal working memory, suggesting that visual sequence memory precedes auditory sequence memory. We further suggest that visual tasks involving sequential comparisons could probe for poor working memory in PRD.
DEVS Approach to Real-time RTI Design for Large-scale Distributed Simulation Systems
Authors: Boukerche Azzedine , Ming Zhang  , Shadid Ahmad
Published: September 2008

HLA/RTI is one of the dominant middleware for large-scale distributed simulation. However, traditional RTI design and resulting implementations have been facing several difficulties, especially in satisfying the requirements for real-time distributed simulations. Many improved or novel RTI designs have been proposed in recent years, which aim to improve the real-time capabilities of RTI systems. Such designs are in general non-formalized, and the realizations of the designs are highly time-consuming and error-prone practices. In this paper, we propose a formal real-time RTI (RT-RTI) design approach using Discrete Event System Specification (DEVS). We discuss the feasibility of using DEVS and, as an additional step, we consider the case study of two recently proposed RT-RTI designs through a formalized DEVS model system. Our focus is how a DEVS component-based formalized design approach can predict some of the key design factors before the design is realized, or can further validate and consolidate realized RT-RTI designs.
A Visibility-Driven Approach for Zone Management in Simulations
Authors: Shirmohammadi Shervin , Kazem Ihab , Tanvir Ahmed Dewan , El-Badaoui Madeh , de Oliveira Jauvane C.
Published: September 2008

Massively multi-user simulations aim to support a large number of users while keeping the communication among the parties synchronous and highly interactive. In this paper, we present a collaborative virtual architecture that supports a large number of users by dividing the virtual environment into multiple adjacent hexagonal regions in order to manage the interest of the entities. A master node, called a hybrid node, constructs a Peer-to-Peer (P2P) overlay network to connect and manage nodes that lie in its region. Messaging is done at the application layer rather than the network layer, and a node-joining algorithm is proposed to reflect the underlying network physical topology onto the data distribution pathways among the end hosts to enhance the system performance. In addition, the introduction of a buffer zone between adjacent zones reduces the number of connections and disconnections that occur when a node frequently moves at the boundary of the two zones and provides more resilience to the system. We also attempt to shift the messaging among parties in one region from a zone-based method to a visibility-driven method to refine their interest by enabling message filtering. The effectiveness of this collaboration architecture is tested through a prototype implementation and a high level application.
G-DEVS/HLA Environment for Distributed Simulations of Workflows
Authors: Zacharewicz Gregory , Frydman Claudia , Giambiasi Norbert
Published: September 2008

We present a Workflow environment allowing distributed simulation based on DEVS/G-DEVS formalisms. A description language for Workflow processes and an automatic transformation of a Workflow into a G-DEVS model have been defined. We then introduce a new distributed Workflow Reference Model with HLA-compliant Workflow components. We detail the HLA objects shared between Workflow federates and present the publishing/subscribing status of each of these federates. Finally, we illustrate the use of this distributed environment with an example of a Microelectronic production Workflow.
Region-based 3D Mesh Compression Using an Efficient Neighborhood-based Segmentation
Authors: Lijun Chen  , Georganas Nicolas D.
Published: September 2008

Due to the popularity of polygonal models in Virtual Reality applications, three-dimensional (3D) mesh compression and segmentation are two active areas of 3D object modeling. Most existing 3D compression algorithms compress the whole object to reduce the local storage requirement and the delays in transmitting objects over the Internet. However, in some interactive applications, the client may be interested in particular section(s) of the object. The server needs to segment the object into parts and send them individually or sequentially. This paper presents a segmentation-based 3D mesh compression scheme that can meet this requirement. We propose an efficient eXtended Multi-Ring neighborhood- (XMR) based 3D mesh segmentation algorithm that decomposes the object into meaningful regions. We then compress them separately and put them into one stream. The common boundary triangles that will be used for sticking the regions together are processed and appended to the end of the stream. This is referred to as a region-conquer-and-stitch scheme.
On the Simulation of Traffic Signals Operation
Authors: Sadoun Balqies
Published: September 2008

Traffic lights are available in almost all cities and towns worldwide. They solve many traffic congestion problems, save numerous human lives and avoid frequent automobile accidents. Optimizing the operation of traffic light systems in roads is essential for any city's economy, safety and environment. Simulation technology is probably the best tool to analyze and optimize the operation and design of traffic light systems. The increasing use of automobiles in cities has lead city administrators and local governments to install traffic lights and detectors in large quantities in order to avoid accidents and optimize the movement of automobiles and humans. Although signalization can solve traffic conflicts at the intersections, it causes stoppage. The chief objective of optimal traffic control is to improve system mobility and throughput at reduced delays. Delays and stops are not only irritating and pricey to drivers and passengers, but they also add to air contamination and energy use. In this paper, we analyze and demonstrate how the timings of a traffic light system are calculated in order to determine the optimum and proper timings needed to optimize traffic flow.
Some Procedures of Selecting the Best Designs with Respect to Quantile
Authors: Chen E. Jack
Published: September 2008

Indifference-zone selection procedures have been used to select a design with the minimum or maximum expected performance measure among a finite number of simulated designs. While there have been significant advancements in selection methodologies, the majority of the selection procedures are developed to process the selection when the performance measures are the mean of some output. In some situations, quantiles provide more suitable information. Quantiles are also more robust to outliers than the mean and standard deviation. Moreover, selection procedures are often derived based on the assumption that the input data are independent and identically distributed (i.i.d.) normal. In this paper we state and justify selection procedures when the ranking parameter is quantile. It is our intention for the quantile estimates to play the role of the i.i.d. normal observations that the original versions of selection procedures process. That is, we assume that our quantile estimates are approximately i.i.d. normal. We perform an empirical study of several stochastic processes to evaluate the performance of the procedure.
A New Security Access Scheme for WLANs and Its Performance Simulation Analysis
Authors: Obaidat Mohammad S. , Guelzim Tarik
Published: September 2008

The IEEE 802.11 standard is becoming the most popular and efficient network topology deployed today. Providing and ensuring the security of wireless network is an essential part to its continuous growth. Goals such as confidentiality and trust imply that every data transmitted by each user stays known only to the communication parties. Authorization of users is also a very important aspect of network integrity. There exist mechanisms defined by the Wi-Fi Protected Access (WPA) protocol that enable such functionality; however, recent attacks on such systems showed that these mechanisms can be defined. In this paper, we propose a new scheme to authenticate and authorize 802.11 wireless nodes within a network. This new layer of security relies on a neural network decision engine that restricts network access to mobile nodes whose physical location is within a threshold distance from the wireless access point or the controller of the network. This method gives an extra layer of security and allows policies to be enforced which only allow network access from a certain section of the network. We give a detailed description of the work done as well as a performance simulation analysis of this scheme.
Transaction Management Issues in Web Service-oriented Electronic Commerce Systems: Performance Evaluation
Authors: Chen Hong-Ren
Published: September 2008

The use of service-oriented technologies has been used increasingly to speed up the application process and respond to changing business needs for many e-commerce systems. However, current e-commerce transaction services are poor at processing data access conflicts in a timely manner. The different timely data access for e-commerce applications should be considered with concurrency control mechanisms. In this paper, we study the concurrency control problem among interleaved web service transactions under differentiated real-time demands. We propose a new method called two-phase locking with fairness principles (2PL-FP), which resolves the concurrent data access for both real-time and non-real-time support operations. The design issue aims to meet the deadline requirements of real-time transactions and minimize the response time of non-real-time transactions in the web service and service-oriented computing environment. Simulation results show that our method can achieve a significant performance improvement compared to current approaches.
Self-Ownership and the Lockean Proviso
Authors: Machan Tibor R.
Published: September 2008

Locke's defense of private property rights includes what is called a proviso— “the Lockean proviso”—and some have argued that in terms of it the right to private property can have various exceptions and it may not even be unjust to redistribute wealth that is privately owned. I argue that this cannot be right because it would imply that one's right to life could also have various exceptions, so anyone's life (and labor) could be subject to conscription if some would need it badly enough. Since this could amount to enslavement and involuntary servitude, it would be morally and legally unacceptable.
Digital Inequality
Authors: Hargittai Eszter , Hinnant Amanda
Published: September 2008

This article expands understanding of the digital divide to more nuanced measures of use by examining differences in young adults' online activities. Young adults are the most highly connected age group, but that does not mean that their Internet uses are homogenous. Analyzing data about the Web uses of 270 adults from across the United States, the article explores the differences in 18- to 26-year-olds' online activities and what social factors explain the variation. Findings suggest that those with higher levels of education and of a more resource-rich background use the Web for more “capitalenhancing” activities. Detailed analyses of user attributes also reveal that online skill is an important mediating factor in the types of activities people pursue online. The authors discuss the implications of these findings for a “second-level digital divide,” that is, differences among the population of young adult Internet users.
Taking Up Offenses: Secondhand Forgiveness and Group Identification
Authors: Brown Ryan P. , Wohl Michael J. A. , Exline Julie Juola
Published: September 2008

When a person or group is mistreated, those not directly harmed by the transgression might still experience antipathy toward offenders, leading to secondhand forgiveness dynamics similar to those experienced by firsthand victims. Three studies examine the role of social identification in secondhand forgiveness. Study 1 shows that the effects of apologies on secondhand victims are moderated by level of identification with the wronged group. Study 2 shows that identification with the United States was associated with less forgiveness and greater blame and desire for retribution directed at the 9/11 terrorists, and these associations were primarily mediated by anger. Finally, Study 3 shows that participants whose assimilation needs were primed were less forgiving toward the perpetrators of an assault on ingroup members than participants whose differentiation needs were primed, an effect that was mediated by empathy for the victims.
Radio geopolitics: broadcasting, listening and the struggle for acoustic spaces
Authors: Pinkerton Alasdair , Dodds Klaus
Published: September 2008

This paper considers some of the interdisciplinary scholarship on radio and sound more generally for the purposes of considering how geopolitical scholarship might reconsider its predominantly visual focus. The first part considers radio and its relationship to studies of propaganda, international diplomacy and even everyday life. Thereafter, attention is given to new themes such as researching radio cultures, broadcasting infrastructure and technology and, finally, the affective impacts of radio on audiences. The conclusion of this paper urges further critical consideration of radio, sound and broadcasting/listener engagement with the well-established geographical literature on music.
Childhood and the politics of scale: descaling children's geographies?
Authors: Ansell Nicola
Published: September 2008

The past decade has witnessed a resurgence of interest in the geographies of children's lives, and particularly in engaging the voices and activities of young people in geographical research. Much of this growing body of scholarship is characterized by a very parochial locus of interest — the neighbourhood, playground, shopping mall or journey to school. In this paper I explore some of the roots of children's geographies' preoccupation with the micro-scale and argue that it limits the relevance of research, both politically and to other areas of geography. In order to widen the scope of children's geographies, some scholars have engaged with developments in the theorization of scale. I present these arguments but also point to their limitations. As an alternative, I propose that the notion of a flat ontology might help overcome some difficulties around scalar thinking, and provide a useful means of conceptualizing sociospatiality in material and non-hierarchical terms. Bringing together flat ontology and work in children's geographies on embodied subjectivity, I argue that it is important to examine the nature and limits of children's spaces of perception and action. While these spaces are not simply `local', they seldom afford children opportunities to comment on, or intervene in, the events, processes and decisions that shape their own lives. The implications for the substance and method of children's geographies and for geographical work on scale are considered.
Thinking through education: the geographies of contemporary educational restructuring
Authors: Thiem Claudia Hanson
Published: September 2008

Despite playing central roles in state-building, economic development, social reproduction, and cultural politics, education has remained on the margins of critical geographical thought. Recent research, however, suggests that geographers are taking notice of the widespread and profound restructuring underway in advanced capitalist education sectors. This paper considers the possibilities for geographical research on (formal) education, and outlines one particular agenda for this emerging field. Rather than advocating a discrete topical specialty, it proposes developing a decentered and outward-looking literature — one in which education systems, institutions, and practices are positioned as useful sites for a variety of theory-building projects. The paper sketches several applications of this `joined-up' approach. `Thinking through' education — either as a constitutive moment or a critical case study of sociospatial transformation — may inform discussions of the geographies of neoliberalization, globalization, and knowledge economy formation.