bluuebunny/crossref_metadata_2025 huggingface dataset:
Inflammation may modulate IL-6 and C-reactive protein gene expression in the adipose tissue: the role of IL-6 cell membrane receptor
Authors: Memoli Bruno , Procino Alfredo , Calabrò Paolo , Esposito Pasquale , Grandaliano Giuseppe , Pertosa Giovanni , Prete Marco Del , Andreucci Michele , Lillo Saverio Di , Ferulano Giuseppe , Cillo Clemente , Savastano Silvia , Colao Annamaria , Guida Brunella
Published: July 2007

Only few studies have been addressed to the presence and regulation of C-reactive protein (CRP) gene expression in different districts of adipose tissue, and no study has investigated the role of adipose tissue in presence of inflammation. Therefore, the aim of this study was to investigate the inflammatory involvement of either adipose tissue or adipose cells (adipocytes and stromal cells, respectively) in patients with chronic inflammatory disease, focusing on regional adipose tissue CRP gene expression. Eighteen patients with inflammatory disease and 14 healthy controls were enrolled. All subjects underwent specific surgical procedures. Inflamed and noninflamed patients provided samples of subcutaneous and/or omental adipose tissue. All samples were analyzed by RT-PCR and real-time PCR for specific gene expression. In addition, both adipocytes and stromal cells were studied by real-time PCR and immunoprecipitation to evaluate either gene or protein expression of CRP. Our results (real-time PCR) demonstrated a higher gene expression of CRP, IL-6, and both IL-6 membrane receptors in subcutaneous samples of inflamed patients than in healthy controls. Furthermore, in omental fragments of inflamed patients, an enhanced mRNA abundance of the same genes, compared with subcutaneous, was observed. The results obtained at cellular level did not provide evidence of any difference between adipocytes and stromal cell CRP gene expression, whereas immunoprecipitation demonstrated the presence of CRP in inflamed subjects. These results provide first-time evidence of the involvement of adipose tissue in the course of chronic inflammatory diseases, with a different degree of participation of the different adipose tissue districts.
Preexisting hypoxia is associated with a delayed but more sustained rise in T/QRS ratio during prolonged umbilical cord occlusion in near-term fetal sheep
Authors: Wibbens Bert , Bennet Laura , Westgate Jenny A. , De Haan Harmen H. , Wassink Guido , Gunn Alistair J.
Published: July 2007

There is limited information about whether preexisting fetal hypoxia alters hemodynamic responses and changes in T/QRS ratio and ST waveform shape during subsequent severe asphyxia. Chronically instrumented near-term sheep fetuses (124 ± 1 days) were identified as either normoxic PaO2 > 17 mmHg ( n = 9) or hypoxic PaO2 ≤ 17 mmHg ( n = 5); then they received complete occlusion of the umbilical cord for 15 min. Umbilical cord occlusion led to sustained bradycardia, severe acidosis, and transient hypertension followed by profound hypotension in both groups. Preexisting hypoxia did not affect changes in mean arterial blood pressure but was associated with a more rapid initial fall in femoral blood flow and vascular conductance and with transiently higher fetal heart rate at 2 min and from 9 to 11 min of occlusion compared with previously normoxic fetuses. Occlusion was associated with a significant but transient rise in T/QRS ratio; preexisting hypoxia was associated with a significant delay in this rise (maxima 3.7 ± 0.4 vs. 6.2 ± 0.5 min), but a slower rate of fall. There was a similar elevation in troponin-T levels 6 h after occlusion in the two groups [median (range) 0.43 (0.08, 1.32) vs. 0.55 (0.16, 2.32) μg/l, not significant]. In conclusion, mild preexisting hypoxia in normally grown singleton fetal sheep is associated with more rapid centralization of circulation after umbilical cord occlusion and delayed elevation of the ST waveform and slower fall, suggesting that chronic hypoxia alters myocardial dynamics during asphyxia.
Reducing blood pressure in SHR with enalapril provokes redistribution of NHE3, NaPi2, and NCC and decreases NaPi2 and ACE abundance
Authors: Yang Li E. , Leong Patrick K. K. , McDonough Alicia A.
Published: July 2007

To determine the effects of long-term angiotensin-converting enzyme inhibition (ACEI) and blood pressure (BP) lowering on renal sodium transporter abundance and distribution in spontaneously hypertensive rats (SHR), 9-wk SHR were treated with enalapril (30 mg·kg−1·day−1) for 4 wk. BP decreased from 156 ± 4 to 96 ± 8 mmHg. Na+/H+ exchanger isoform 3 (NHE3) and Na+-Pi cotransporter type 2 (NaPi2) localized to the body of the microvilli (MV) in normotensive rat strains. In untreated SHR, NHE3 partially retracted from the body to base of the MV and NaPi2 retracted to subapical vesicles. After enalapril treatment of SHR, NHE3 fully retracted to the base of the MV and, by density gradient fractionation, NHE3, NaPi2, dipeptidyl peptidase IV, myosin VI, Na-Cl cotransporter, and cortical Na-K-Cl cotransporter redistributed from low-density (apical enriched) to high-density (endosome enriched) membranes. Enalapril decreased total abundance of myosin VI (to 0.51 ± 0.18 of untreated), ACE (0.67 ± 0.22), and cortical NaPi2 (0.83 ± 0.10). Normalizing SHR BP with HRH (7.5 mg/day hydralazine, 0.15 mg/day reserpine, and 3 mg/day hydrochlorothiazide) did not change Na+ transporter density distribution or abundance. We conclude that lowering BP to normal levels in SHR does not normalize Na+ transporter distribution, rather, chronic ACEI treatment provokes retraction of Na+ transporters and associated proteins from transport-relevant domains of apical membranes and/or reduces their abundance.
Internal Spatial Organization of Receptive Fields of Complex Cells in the Early Visual Cortex
Authors: Sasaki Kota S. , Ohzawa Izumi
Published: July 2007

The receptive fields of complex cells in the early visual cortex are economically modeled by combining outputs of a quadrature pair of linear filters. For actual complex cells, such a minimal model may be insufficient because many more simple cells are thought to make up a complex cell receptive field. To examine the minimalist model physiologically, we analyzed spatial relationships between the internal structure (subunits) and the overall receptive fields of individual complex cells by a two-stimulus interaction technique. The receptive fields of complex cells are more circular and only slightly larger than their subunits in size. In addition, complex cell subunits occupy spatial extents similar to those of simple cell receptive fields. Therefore in these respects, the minimalist schema is a fair approximation to actual complex cells. However, there are violations against the minimal model. Simple cell receptive fields have significantly fewer subregions than complex cell subunits and, in general, simple cell receptive fields are elongated more horizontally than vertically. This bias is absent in complex cell subunits and receptive fields. Thus simple cells cannot be equated to individual complex cell subunits and spatial pooling of simple cells may occur anisotropically to constitute a complex cell subunit. Moreover, when linear filters for complex cell subunits are examined separately for bright and dark responses, there are significant imbalances and position displacements between them. This suggests that actual complex cell receptive fields are constructed by a richer combination of linear filters than proposed by the minimalist model.
Identification of genomic targets downstream of p38 mitogen-activated protein kinase pathway mediating tumor necrosis factor-α signaling
Authors: Zer Cindy , Sachs George , Shin Jai Moo
Published: July 2007

Inhibition of p38 MAPK suppresses the expression of proinflammatory cytokines such as TNF-α and IL-1β in macrophages and fibroblast-like synoviocytes (FLS). However, there have been no genomewide studies on the gene targets of p38 MAPK signaling in synoviocytes. Microarray technology was applied to generate a comprehensive analysis of all genes regulated by the p38 MAPK signaling pathway in FLS. Gene expression levels were measured with Agilent oligonucleotide microarrays. Four independent sets of mRNA modulated by TNF-α and vehicle were used to measure the change of gene expression due to TNF-α, and three experiments were done to ascertain the effect of SB-203580, a p38 MAPK inhibitor, on TNF-α-induced genes. Microarray data were validated by RT-quantitative polymerase chain reaction. One hundred forty-one significantly expressed genes were more than twofold upregulated by TNF-α. Thirty percent of these genes were downregulated by the p38 inhibitor SB-203580, whereas 67% of these genes were not significantly changed. The SB-203580-inhibited genes include proinflammatory cytokines such as interleukins and chemokines, proteases including matrix metallopeptidases, metabolism-related genes such as cyclooxygenases and phosphodiesterase, genes involved in signal transduction, and genes encoding for transcription factors, receptors, and transporters. Approximately one-third of the TNF-α-induced genes in FLS are regulated by the p38 MAPK signal pathway, showing that p38 MAPK is a possible target for suppressing proinflammatory gene expressions in rheumatoid arthritis.
Disruption of a novel regulatory locus results in decreased Bdnf expression, obesity, and type 2 diabetes in mice
Authors: Sha Haibo , Xu Jingyue , Tang Jing , Ding Jun , Gong Jianfeng , Ge Xiaomei , Kong Dong , Gao Xiang
Published: July 2007

Mutants of brain-derived neurotrophic factor (BDNF) are associated with obesity. However, the regulatory mechanism of BDNF expression is still unclear. We developed a novel mutant mouse line, transgenic insertional mutants with obesity, named Timo, in which a potential regulatory locus of Bdnf was disrupted by transgene insertion. The insertion site was identified and lies 857 kb upstream of the Bdnf gene. The disrupted genomic locus is conserved across the mouse, rat, dog, and human genome and contains several highly conserved elements that are able to upregulate reporter gene expression in vitro. Along with downregulation of BDNF to ∼30% of wild-type animals, Timo/ Timo mice exhibited increased body weight and fat content with hepatic steatosis and elevated serum levels of leptin, cholesterol, and LDL cholesterol. These mutant mice also showed obesity-independent insulin resistance, hyperinsulinemia, impaired glucose tolerance, age-dependent hyperglycemia, and shortened life span. Molecular and phenotype analysis of Timo/ Timo mice indicated the existence of a genome locus, lying 857 kb upstream of the Bdnf gene, that regulates BDNF expression, body weight, and glucose homeostasis.
Heat map visualization of high-density clinical chemistry data
Authors: Auman J. Todd , Boorman Gary A. , Wilson Ralph E. , Travlos Gregory S. , Paules Richard S.
Published: July 2007

Clinical chemistry data are routinely generated as part of preclinical animal toxicity studies and human clinical studies. With large-scale studies involving hundreds or even thousands of samples in multiple treatment groups, it is currently difficult to interpret the resulting complex, high-density clinical chemistry data. Accordingly, we conducted this study to investigate methods for easy visualization of complex, high-density data. Clinical chemistry data were obtained from male rats each treated with one of eight different acute hepatotoxicants from a large-scale toxicogenomics study. The raw data underwent a Z-score transformation comparing each individual animal's clinical chemistry values to that of reference controls from all eight studies and then were visualized in a single graphic using a heat map. The utility of using a heat map to visualize high-density clinical chemistry data was explored by clustering changes in clinical chemistry values for >400 animals. A clear distinction was observed in animals displaying hepatotoxicity from those that did not. Additionally, while animals experiencing hepatotoxicity showed many similarities in the observed clinical chemistry alterations, distinct differences were noted in the heat map profile for the different compounds. Using a heat map to visualize complex, high-density clinical chemistry data in a single graphic facilitates the identification of previously unrecognized trends. This method is simple to implement and maintains the biological integrity of the data. The value of this clinical chemistry data transformation and visualization will manifest itself through integration with other high-density data, such as genomics data, to study physiology at the systems level.
DNA Damage Induces Alternative Lengthening of Telomeres (ALT)–Associated Promyelocytic Leukemia Bodies that Preferentially Associate with Linear Telomeric DNA
Authors: Fasching Clare L. , Neumann Axel A. , Muntoni Alessandra , Yeager Thomas R. , Reddel Roger R.
Published: July 2007

The linear chromosomes of vertebrates terminate in telomeres that consist of a tandemly repeated hexameric sequence, 5′TTAGGG3′. Telomeres form a protective loop structure (t-loop), which is thought to prevent them from being recognized as a double-strand break. Approximately 10% of human tumors prevent shortening of their telomeres by using a recombination-mediated alternative lengthening of telomeres (ALT) mechanism. ALT-positive human cells contain extrachromosomal telomere repeat (ECTR) DNA that may either be circular or linear. It has been proposed that ECTR may be generated by recombination events involving the t-loop. A proportion of the cells within ALT-positive cell populations contain promyelocytic leukemia (PML) nuclear bodies that contain telomeric DNA and telomere-binding proteins that are called ALT-associated PML bodies (APB). Although the presence of APBs is very useful for determining whether tumors and cell lines use the ALT mechanism, the function of APBs is unknown. It has previously been shown that telomeric DNA is particularly susceptible to damage by hydrogen peroxide and N-methyl-N′-nitro-N-nitrosoguanidine. We report here that these DNA-damaging agents induce both linear and circular ECTR DNA in ALT cells and increase the proportion of cells that contain APBs. We partially purified APBs and showed that the telomeric repeat DNA they contain is predominantly linear. We propose that a function of APBs is to sequester linear telomeric DNA. [Cancer Res 2007;67(15):7072–7]
Improvement/Maintenance and Reorientation as Central Features of Coping with Major Life Change and Loss: Contributions of Three Life-Span Theories
Authors: Boerner Kathrin , Jopp Daniela
Published: July 2007

This article focuses on the common and unique contributions of three major life-span theories in addressing improvement/maintenance and reorientation, which represent central processes of coping with major life change and loss. For this purpose, we review and compare the dual-process model of assimilative and accommodative coping, the model of selection, optimization, and compensation, and the life-span theory of control. Although these theories share many basic assumptions about developmental regulation, each theory also has unique elements and offers varying degrees of refinement regarding particular aspects. To facilitate research on improvement/maintenance and reorientation guided by these theories, we identify conceptual overlap as well as delineate differential features with respect to key definitions, predictions, and related empirical evidence. We conclude with recommendations and suggestions for future research.
Haplotype Diversity in Four Genes (CLCNKA, CLCNKB, BSND, NEDD4L) Involved in Renal Salt Reabsorption
Authors: Sile Saba , Velez Digna R. , Gillani Niloufar B. , Alexander Charles R. , George Jr Alfred L. , Williams Scott M.
Published: July 2007

Objective: Differences exist among various populations with regards to hypertension prevalence, severity, progression and response to therapy. Such differences may be due to genetic or environmental factors. We characterized the genetic variation and haplotype diversity of four hypertension candidate genes (CLCNKA, CLCNKB, BSND, NEDD4L) in four different ethnic groups (Caucasian Americans, African-Americans, Han Chinese, and Mexican-Americans). Methods: We genotyped 42 single nucleotide polymorphisms across the four genes in equal numbers of each ethnically defined population, then tested for linkage disequilibrium, computed allelic and haplotype frequencies, and compared data across the different ethnic groups. Results: We identified significant genotype and allele frequency differences among ethnic groups. The strongest differences were observed between African-American and Mexican-Americans and between Caucasian and Mexican-Americans. In addition, haplotype blocks were defined for BSND, CLCNKA_B and NEDD4L in the four populations examined. Completely mismatched (‘yin yang’) haplotypes were also observed. We found that the number of inferred halpotypes varied gene to gene and in some instances between the populations for a given gene indicating substantial haplotype diversity. The haplotype diversity among the various ethnic populations observed in our study was greater than that reported in Perlegen database. Conclusions: Haplotype diversity in hypertension candidate genes has important implications for designing and evaluating candidate gene or genome-wide blood pressure association studies that consider these genes.
Nuchal Translucency Measurements for First-Trimester Screening: The ‘Price’ of Inaccuracy
Authors: Evans Mark I. , Van Decruyes Hilde , Nicolaides Kypros H.
Published: July 2007

Objective: First-trimester aneuploidy screening is in transition from the phase of ‘development’ to that of ‘diffusion.’ As with all other technologies, there is risk of diminished performance until newer centers are well experienced. Typically, inexperienced sonographers under-measure nuchal translucency (NT), and experience, training and continual monitoring of data are needed to ensure that measurements do not deviate. Here we assess the impact of systematic under-measurement on abnormality detection. Study Design: Actual NT measurements from 13,887 normal fetuses, 82 with trisomy 21 (T21) and 61 with other abnormalities (OA) with birth outcome data were mathematically modified to show either a 25% or 0.5-mm decrease in measurement. The impact upon sensitivity and screen-positive rates were assessed. Results: Reducing the NT measurements of T21 and OA cases lowers the sensitivity from 81.7 and 70.5%, respectively, to 67.1 and 62.3% (p < 0.01). If normals are correspondingly lowered, then the screen-positive rates are reduced from 6.9 to 2.0 and 2.5%. To maintain the same screen-positive rates and sensitivity, the risk threshold would have to be increased from 1/300 to 1/556. Conclusion: Minor inaccuracies in NT measurements as small as 25% or 0.5 mm will have very significant negative impacts upon abnormality detection, reducing detection rates by 18% (81.7 to 67.1%). Just as it is completely accepted that laboratory measurements require standardization and quality assurance, NT measurements, because they are used in an algorithm, need to be treated with the same rigor. That way the published data from centers that have developed such screening can be applied by other operators at other sites when counseling their patients.
Antenatal MRI Diagnosis of Massive Subchorionic Hematoma: A Case Report
Authors: Gupta Rohini , Sharma Raju , Jain Tarun , Vashisht Sushma
Published: July 2007

Massive subchorionic hematoma is a large maternal blood clot, which separates the chorionic plate from the villous chorion [Kojima K, et al: Fetal Diagn Ther 2001;16:57–60]. It is an uncommon condition associated with poor perinatal prognosis and intrauterine growth retardation [Tan WH, et al: Fetal Diagn Ther 1997;76:381–383, Nishijima K, et al: Fetal Diagn Ther 2005;20:23–26]. Ultrasound may not be able to differentiate this condition from other placental abnormalities [Kojima K, et al: Fetal Diagn Ther 2001;16:57–60]. We report a case of massive subchorionic hematoma where the antenatal diagnosis was made on MRI.
Jarcho-Levin Syndrome Presenting as Neural Tube Defect: Report of Four Cases and Pitfalls of Diagnosis
Authors: Dane Banu , Dane Cem , Aksoy Figen , Cetin Ahmet , Yayla Murat
Published: July 2007

Jarcho-Levin syndrome (JLS) causes severe vertebral and thoracic deformity and has an autosomal-recessive mode of inheritance. Prenatal diagnosis may be difficult in some cases without the history of an affected baby. We present 4 cases of JLS with neural tube defects as the prominent finding. In 2 of them the deformity of the thorax was minimal and was not detected by ultrasonography. Rib anomalies were revealed with radiological and pathological examinations after the termination. The location of the vertebral defect may be the determinant factor for the severity of the thoracic deformity. The real recurrence risk could only be found out after postnatal examinations in cases with neural tube defects.
Thoracoamniotic Shunting with Double-Basket Catheters for Fetal Chylothorax in the Second Trimester
Authors: Murabayashi N. , Sugiyama T. , Kusaka H. , Sagawa N.
Published: July 2007

The progress of a fetal severe pleural effusion at mid-trimester is extremely poor. We encountered a fetus that developed a severe left pleural effusion at 21 weeks of gestation. The pleural effusion was removed by thoracocentesis at 22 weeks. Cytology revealed abundant lymphocytes, suggesting chylothorax. However, a reaccumulation of pleural effusion with hydrops was subsequently noted, and a thoracoamniotic shunt with double-basket catheters was installed at 23 weeks. The pleural effusion decreased after 24 weeks and completely disappeared at 26 weeks. At 40 weeks of gestation, a female infant was born by vaginal delivery, with no evidence of pleural effusion. We would like to stress that thoracoamniotic shunt with double-basket catheters in the second trimester is effective for pleural effusion with hydrops.
Adaptation to Real Motion Reveals Direction-selective Interactions between Real and Implied Motion Processing
Authors: Lorteije Jeannette A. M. , Kenemans J. Leon , Jellema Tjeerd , van der Lubbe Rob H. J. , Lommers Marjolein W. , van Wezel Richard J. A.
Published: July 2007

Viewing static pictures of running humans evokes neural activity in the dorsal motion-sensitive cortex. To establish whether this response arises from direction-selective neurons that are also involved in real motion processing, we measured the visually evoked potential to implied motion following adaptation to static or moving random dot patterns. The implied motion response was defined as the difference between evoked potentials to pictures with and without implied motion. Interaction between real and implied motion was found as a modulation of this difference response by the preceding motion adaptation. The amplitude of the implied motion response was significantly reduced after adaptation to motion in the same direction as the implied motion, compared to motion in the opposite direction. At 280 msec after stimulus onset, the average difference in amplitude reduction between opposite and same adapted direction was 0.5 μV on an average implied motion amplitude of 2.0 μV. These results indicate that the response to implied motion arises from direction-selective motion-sensitive neurons. This is consistent with interactions between real and implied motion processing at a neuronal level.
Strategic Modulation of Cognitive Control
Authors: Lungu Ovidiu V. , Liu Tao , Waechter Tobias , Willingham Daniel T. , Ashe James
Published: July 2007

The neural substrate of cognitive control is thought to comprise an evaluative component located in the anterior cingulate cortex (ACC) and an executive component in the prefrontal cortex (PFC). The control mechanism itself is mainly local, triggered by response conflict (monitored by the ACC) and involving the allocation of executive resources (recruited by the PFC) in a trial-to-trial fashion. However, another way to achieve control would be to use a strategic mechanism based on long-term prediction of upcoming events and on a chronic response strategy that ignores local features of the task. In the current study, we showed that such a strategic control mechanism was based on a functional dissociation or complementary relationship between the ACC and the PFC. When information in the environment was available to make predictions about upcoming stimuli, local task features (e.g., response conflict) were no longer used as a control signal. We suggest that having separate control mechanisms based on local or global task features allows humans to be persistent in pursuing their goals, yet flexible enough to adapt to changes in the environment.
How the Camel Lost Its Hump: The Impact of Object Typicality on Event-related Potential Signals in Object Decision
Authors: Hauk O. , Patterson K. , Woollams A. , Cooper-Pye E. , Pulvermüller F. , Rogers T. T.
Published: July 2007

Using an object decision task, event-related potentials (ERPs), and minimum norm current source estimates, we investigated early spatiotemporal aspects of cortical activation elicited by line drawings that were manipulated on two dimensions: authenticity and typicality. Authentic objects were those that match real-world experience, whereas nonauthentic objects were “doctored” by deletion or addition of features (e.g., a camel with its hump removed, a hammer with two handles). The main manipulation of interest for both authentic and nonauthentic objects was the degree of typicality in the object's structure: typical items are composed of parts that have tended to co-occur across many different objects in the perceiver's experience. The ERP pattern revealed a significant typicality effect at 116 msec after stimulus onset. Both atypical authentic objects (e.g., a camel with its hump) and atypical nonauthentic objects (e.g., a jackal with a hump) elicited stronger brain activation than did objects with typical structure. A significant effect of authenticity was observed at 480 msec, with stronger activation for the nonauthentic objects. The factors of typicality and authenticity interacted at 160 and 330 msec. The most prominent source of the typicality effect was the bilateral occipitotemporal cortex, whereas the interaction and the authenticity effects were mainly observed in the more anterior bilateral temporal cortex. These findings support the hypothesis that within the first few hundred milliseconds after stimulus presentation onset, visual-form-related perceptual and conceptual processes represent distinct but interacting stages in object recognition.
Impaired Perceptual Memory of Locations across Gaze-shifts in Patients with Unilateral Spatial Neglect
Authors: Vuilleumier Patrik , Sergent Claire , Schwartz Sophie , Valenza Nathalie , Girardi Michele , Husain Masud , Driver Jon
Published: July 2007

Right hemisphere lesions often lead to severe disorders in spatial awareness and behavior, such as left hemispatial neglect. Neglect involves not only pathological biases in attention and exploration but also deficits in internal representations of space and spatial working memory. Here we designed a new paradigm to test whether one potential component may involve a failure to maintain an updated representation of visual locations across delays when a gaze-shift intervenes. Right hemisphere patients with varying severity of left spatial neglect had to encode a single target location and retain it across an interval of 2 or 3 sec, during which the target was transiently removed, before a subsequent probe appeared for a same/different location judgment. During the delay, gaze could have to shift to either side of the remembered location, or no gaze-shift was required. Patients showed a dramatic loss of memory for target location after shifting gaze to its right (toward their “intact” ipsilesional side), but not after leftward gaze-shifts. Such impairment arose even when the target initially appeared in the right visual field, before being updated leftward due to right gaze, and even when gaze returned to the screen center before the memory probe was presented. These findings indicate that location information may be permanently degraded when the target has to be remapped leftward in gaze-centric representations. Across patients, the location-memory deficit induced by rightward gaze-shifts correlated with left neglect severity on several clinical tests. This paradoxical memory deficit, with worse performance following gaze-shifts to the “intact” side of space, may reflect losses in gaze-centric representations of space that normally remap a remembered location dynamically relative to current gaze. Right gaze-shifts may remap remembered locations leftward, into damaged representations, whereas left gaze-shifts will require remapping rightward, into intact representations. Our findings accord with physiological data on normal remapping mechanisms in the primate brain but demonstrate for the first time their impact on perceptual spatial memory when damaged, while providing new insights into possible components that may contribute to the neglect syndrome.
Neural Correlates of Concreteness in Semantic Categorization
Authors: Pexman Penny M. , Hargreaves Ian S. , Edwards Jodi D. , Henry Luke C. , Goodyear Bradley G.
Published: July 2007

In some contexts, concrete words (CARROT) are recognized and remembered more readily than abstract words (TRUTH). This concreteness effect has historically been explained by two theories of semantic representation: dual-coding [Paivio, A. Dual coding theory: Retrospect and current status. Canadian Journal of Psychology, 45, 255–287, 1991] and context-availability [Schwanenflugel, P. J. Why are abstract concepts hard to understand? In P. J. Schwanenflugel (Ed.), The psychology of word meanings (pp. 223–250). Hillsdale, NJ: Erlbaum, 1991]. Past efforts to adjudicate between these theories using functional magnetic resonance imaging have produced mixed results. Using event-related functional magnetic resonance imaging, we reexamined this issue with a semantic categorization task that allowed for uniform semantic judgments of concrete and abstract words. The participants were 20 healthy adults. Functional analyses contrasted activation associated with concrete and abstract meanings of ambiguous and unambiguous words. Results showed that for both ambiguous and unambiguous words, abstract meanings were associated with more widespread cortical activation than concrete meanings in numerous regions associated with semantic processing, including temporal, parietal, and frontal cortices. These results are inconsistent with both dual-coding and context-availability theories, as these theories propose that the representations of abstract concepts are relatively impoverished. Our results suggest, instead, that semantic retrieval of abstract concepts involves a network of association areas. We argue that this finding is compatible with a theory of semantic representation such as Barsalou's [Barsalou, L. W. Perceptual symbol systems. Behavioral & Brain Sciences, 22, 577–660, 1999] perceptual symbol systems, whereby concrete and abstract concepts are represented by similar mechanisms but with differences in focal content.
Correction of Location and Orientation Errors in Electromagnetic Motion Tracking
Authors: Hagedorn John G. , Satterfield Steven G. , Kelso John T. , Austin Whitney , Terrill Judith E. , Peskin Adele P.
Published: July 2007

We describe a method for calibrating an electromagnetic motion tracking device. Algorithms for correcting both location and orientation data are presented. In particular, we use a method for interpolating rotation corrections that has not previously been used in this context. This method, unlike previous methods, is rooted in the geometry of the space of rotations. This interpolation method is used in conjunction with Delaunay tetrahedralization to enable correction based on scattered data samples. We present measurements that support the assumption that neither location nor orientation errors are dependent on sensor orientation. We give results showing large improvements in both location and orientation errors. The methods are shown to impose a minimal computational burden.
Haptic Simulation of Manipulator Collisions Using Dynamic Proxies
Authors: Mitra Probal , Niemeyer Günter
Published: July 2007

Haptic simulations aim to create an immersive, interactive computer generated environment, using haptic devices to render forces to the user based on interactions in the virtual world. In many applications, these simulations must be capable of handling interactions between multiple users, multiple hands, and complex virtual tools. In particular, consider the example of simulating two-handed robotic surgery, where each hand independently directs its own surgical robot to manipulate a tool.

Traditionally only quasi-static, point-like proxies are used to represent the human in virtual environments. In previous works, we proposed dynamic proxies to improve upon this notion. Giving the proxy first order, velocity based dynamics makes it massless but capable of producing crisp dynamic interaction forces. With this paper, we generalize the proxy concept to the case of independent, multiple degree-of-freedom virtual manipulators, by giving the proxy not only first-order dynamics, but its own kinematic properties as well. Like real robots, the virtual manipulators' tips track the user and master motion while generating force feedback. Interactions between the virtual arms and with other objects are implemented as geometric constraints on the tip velocities, and solved in a linearly constrained least-squares minimization. A stability proof is given in terms of passivity. The approach is demonstrated on an actual two-handed haptic console, running a real-time simulation of a pair of six degree-of-freedom virtual manipulators with cylindrical links.
Effects of Virtual Reality Immersion and Walking Speed on Coordination of Arm and Leg Movements
Authors: Giphart J. E. , Chou Y.-H. , Kim D. H. , Bortnyk C. T. , Wagenaar R. C.
Published: July 2007

The present study focused on the impact of immersive virtual reality (VR) technology on the coordination dynamics of walking, because of VR-induced symptoms and effects (e.g., motion sickness, postural instability, and disorientation) reported in the literature. Subjects were instructed to walk on a treadmill in a virtual and a real environment, while walking speeds were systematically varied. The virtual laboratory environment closely resembled the real laboratory environment. A third experimental condition was included controlling for the restricted view of a head mounted display (HMD) of the VR system. Movement of arms and legs were recorded with an Optotrak system. The main finding was that, for all speed conditions, there was an increased stride frequency in the VR environment compared to the other conditions. At the lower walking speeds, this coincided with a stronger locking of the arm movements on the stride frequency, and an increased mean relative phase between left arm and right arm movements as well as between ipsilateral arm and leg movements. No significant differences in the stability of the walking patterns were observed. Most importantly though, the impact of VR immersion was not large, was primarily limited to the lower walking velocity range, and could be further reduced by correcting for the effects of increased stride frequency by applying dimensionless analysis. The restricted view of the HMD did not significantly influence walking coordination. On the basis of these findings, it is concluded that immersive VR is a suitable tool to investigate perception-action coupling during walking, allowing for a systematic manipulation of optic flow parameters.
A Multiuser Multiperspective Stereographic QTVR Browser Complemented by Java3D Visualizer and Emulator
Authors: Cohen Michael , Bolhassan Noor Alamshah , Fernando Owen Noel Newton
Published: July 2007

To support multiperspective and stereographic image display systems intended for multiuser applications, we have developed two integrated multiuser multiperspective stereographic browsers, respectively featuring IBR-generated egocentric and CG exocentric perspectives. The first one described, “VR4U2C” (‘virtual reality for you to see’), uses Apple's QuickTime VR technology and the Java programming language together with the support of the QuickTime for Java library. This unique QTVR browser allows coordinated display of multiple views of a scene or object, limited only by the size and number of monitors or projectors assembled around or among users (for panoramas or turnoramas) in various viewing locations. The browser also provides a novel solution to limitations associated with display of QTVR imagery: its multinode feature provides interactive stereographic QTVR (dubbed SQTVR) to display dynamically selected pairs of images exhibiting binocular parallax, the stereoscopic depth percept enhanced by motion parallax from displacement of the viewpoint through space coupled with rotation of the view through a 360° horizontal panorama. This navigable approach to SQTVR allows proper occlusion/disocclusion as the virtual standpoint shifts, as well as natural looming of closer objects compared to more distant ones. We have integrated this stereographic panoramic browsing application in a client/server architecture with a sibling client, named “Just Look at Yourself!” which is built with Java3D and allows realtime visualization of the dollying and viewpoint adjustment as well as juxtaposition and combination of stereographic CG and IBR displays. “Just Look at Yourself!” visualizes and emulates VR4U2C, embedding avatars associated with cylinder pairs wrapped around the stereo standpoints texture-mapped with a set of panoramic scenes into a 3D CG model of the same space as that captured by the set of panoramas. The transparency of the 3D CG polygon space and the photorealistic stereographic 360° scenes, as well as the size of the stereo goggles through which the CG space is conceptually viewed and upon which the 360° scenes are texture-mapped, can be adjusted at runtime to understand the relationship of the spaces.
Analyzing Ordinal Scales in Studies of Virtual Environments: Likert or Lump It!
Authors: Gardner Henry J. , Martin Michael A.
Published: July 2007

Likert scaled data, which are frequently collected in studies of interaction in virtual environments, demand specialized statistical tools for analysis. The routine use of statistical methods appropriate for continuous data in this context can lead to significant inferential flaws. Likert scaled data are ordinal rather than interval scaled and need to be analyzed using rank based statistical procedures that are widely available. Likert scores are “lumpy” in the sense that they cluster around a small number of fixed values. This lumpiness is made worse by the tendency for subjects to cluster towards either the middle or the extremes of the scale. We suggest an ad hoc method to deal with such data which can involve a further lumping of the results followed by the application of nonparametric statistics.

Averaging Likert scores over several different survey questions, which is sometimes done in studies of interaction in virtual environments, results in a different sort of lumpiness. The lumped variables which are obtained in this manner can be quite murky and should be used with great caution, if at all, particularly if the number of questions over which such averaging is carried out is small.
The Use of Questionnaire Data in Presence Studies: Do Not Seriously Likert
Authors: Slater Mel , Garau Maia
Published: July 2007

The problems of valid design of questionnaires and analysis of ordinal response data from questionnaires have had a long history in the psychological and social sciences. Gardner and Martin (2007, this issue) illustrate some of these problems with reference to an earlier paper (Garau, Slater, Pertaub, & Razzaque, 2005) that studied copresence with virtual characters within an immersive virtual environment. Here we review the critique of Gardner and Martin supporting their main arguments. However, we show that their critique could not take into account the historical circumstances of the experiment described in the paper, and moreover that a reanalysis using more appropriate statistical methods does not result in conclusions that are different from those reported in the original paper. We go on to argue that in general such questionnaire data is treated far too seriously, and that a different paradigm is needed for presence research—one where multivariate physiological and behavioral data is used alongside subjective and questionnaire data, with the latter not having any specially privileged role.
Bakhtin, Green, and the Imagining of King Saul
Authors: Bodner Keith
Published: July 2007

This is an introduction to and brief interpretation of a collection of papers first delivered in November 2006 at a section meeting of the Society of Biblical Literature in Washington DC. The section was entitled "Bakhtin and the Biblical Imagination," and the particular subject under review was a monograph by Professor Barbara Green, How Are the Mighty Fallen? A Dialogical Study of King Saul in 1 Samuel (JSOTS 365; Sheffield: Sheffield Academic Press, 2003).
Response to Barbara Green, How Are the Mighty Fallen?
Authors: Birch Bruce
Published: July 2007

Barbara Green's monograph, How Are the Mighty Fallen?, opens new vistas for the interpretation of 1 Samuel. After a summary of some basic points of Green's work, she is engaged following three categories that she sets out for her readers: (1) 1 Samuel as part of the Deuteronomistic History addressing an exilic audience; (2) the reading strategy of Mikhail Bakhtin; (3) the attempt at a "co-authorial" reading based on Green's commitment to "biblical spirituality." Green is largely successful in her enterprise as she evokes dialogue in her readers and holds out to them, as does Bakhtin, the "unfinalizable" nature of language.
Response to How Are the Mighty Fallen?
Authors: Brueggemann Walter
Published: July 2007

Barbara Green's monograph, How Are the Mighty Fallen?, shows her to be a strong reader of 1 Samuel, whose interpretive efforts function as both a co-author of 1 Samuel and co-creator of Saul and his cast of characters. Her dialogic style of reading, taken from Bakhtin, allows readers to engage her interpretation without having to agree to all her conclusions. Her facility with Bakhtinian analysis, however, means at times that Bakhtin intrudes on the conversation she engenders with her readers. Her distinction between the "real" God (who "wishes us well") and the God of the text requires further reflection, even if there is no final answerability from the human side. Green envisions a practice of reading, study, and engagement that is profoundly dialogical, inviting scholarly analysis beyond its conventional objectivism, but vigorously resisting a careless subjectivism that now so much jeopardizes our common work.
Response to How Are the Mighty Fallen? A Dialogical Study of King Saul in 1 Samuel
Authors: Newsom Carol
Published: July 2007

Barbara Green's monograph, How Are the Mighty Fallen?, opens new vistas for the interpretation of 1 Samuel. No other work has attempted to use Bakhtin's thought so systematically in its interpretive project. In one sense the book might be viewed as a kind of experimental workshop in which the usefulness and generative potential of Bakhtin's categories are systematically explored. One of the risks in such a procedure is that not everything will work equally well—or, conversely, that there will not finally be an integral relationship between the Bakhtinian categories and the reading that is produced. Perhaps the most useful applications of Bakhtinian categories are "answerability" and "architectonics." Two of his concepts employed by Green that are found less satisfactorily are his understanding of genre and chronotope.
Response to Panel on How Are the Mighty Fallen?
Authors: Green Barbara
Published: July 2007

These generous responses to "How Are the Mighty Fallen?" raise three substantive issues that invite dialogue. First is the question of methodology, whether the use of Bakhtin to read scripture clarifies or obfuscates the text. Second is the difficulty in sorting the connections between 1 Samuel and the Deuteronomistic History. Finally is the puzzling question of biblical spirituality, the relationship between the textual God and the "real" God. All of these issues provide productive invitations to further discussion.
In Memoriam: Paul S. Minear
Authors: Black C. Clifton
Published: July 2007

Paul S. Minear was one of the pre-eminent American biblical scholars of the 20th century. He died just after his 101st birthday in February 2007. Minear retired as a professor in 1971 from Yale University Divinity School. He was a prolific author and a member of the Faith and Order Commission of the World Council of Churches; President of Studiorum Novi Testamenti Societas (1964-65); President of The American Theological Society (1965-66); and member of the committee that produced the New Revised Standard Version (1967-88). The summary of his life and commitments introduces his last article, written at the age of 100. It is followed by a comprehensive bibliography of his books and published articles compiled by Laura Sweat.
Two Secrets, Two Disclosures
Authors: Minear Paul
Published: July 2007

Matthew 11:25-30, with its prayer, soliloquy and promise, may have served as a working outline for the way that the author of Matthew's Gospel understood his story as a whole. Two related secrets are revealed in these verses that are further explicated in the narrative as a whole, namely that God and Jesus have identities that reinforce one another as Father and Son. Particularly the events of cross and resurrection explicate how it is that no one knows the Son except the Father and no one knows the Father except the Son.
Aerosol Properties and Processes: A Path from Field and Laboratory Measurements to Global Climate Models
Authors: Ghan Steven J. , Schwartz Stephen E.
Published: July 2007

Aerosol particles in the lower atmosphere exert a substantial influence on climate and climate change through a variety of complex mechanisms. Consequently, there is a need to represent these influences in global climate models, and models have begun to include representations of these influences. However, the present treatment of aerosols in global climate models is highly simplified, omitting many processes and feedbacks that are thought to be climatically important. Thus, there is need for substantial improvement. Here we describe the strategy of the U.S. Department of Energy for improving representation of the properties, processes, and effects of tropospheric aerosols in global climate models. The strategy begins with a foundation of field and laboratory measurements that provide the basis for modules describing specific aerosol properties and processes. These modules are then integrated into regional aerosol models, which are evaluated by comparison with field measurements. Issues of scale are then addressed so that the modules can be applied to global aerosol models, which are evaluated by comparison with satellite retrievals and other observations. Finally, the validated set of modules is applied in global climate models for multicentury simulations. This strategy is expected to be applied to successive generations of global climate models.