bluuebunny/crossref_metadata_2025_split huggingface dataset:
Difficulty of Discrimination Modulates Attentional Capture by Regulating Attentional Focus
Authors: Sawaki Risa , Katayama Jun'ichi 
Published: May 2008

Abstract
Attentional capture for distractors is enhanced by increasing the difficulty of discrimination between the standard and the target in the three-stimulus oddball paradigm. In this study, we investigated the cognitive mechanism of this modulation of attentional capture. Event-related brain potentials were recorded from participants while they performed a visual three-stimulus oddball paradigm (frequent standard, rare target, and rare distractor). The discrimination difficulty between standard and target was manipulated in the central location. Distractor stimuli were presented in the central or surrounding locations. The P3a component was elicited by distractor stimuli and was used as a measure of attentional capture. The results revealed that discrimination difficulty had opposite effects on the P3a response between central and surrounding locations. With an increase in the difficulty of discrimination, the P3a response was enhanced when distractor stimuli were presented in the central location. In contrast, the P3a response was reduced when distractor stimuli were presented in a surrounding location. This finding suggests that spatial attention was focused by the difficulty of discrimination, and deviant processing was increased within its focus but decreased outside its focus. Therefore, attentional capture for deviant distractors is modulated by top–down controlled attentional focus.
Distinctive Neural Mechanisms Supporting Visual Object Individuation and Identification
Authors: Xu Yaoda 
Published: May 2008

Abstract
Many everyday activities, such as driving on a busy street, require the encoding of distinctive visual objects from crowded scenes. Given resource limitations of our visual system, one solution to this difficult and challenging task is to first select individual objects from a crowded scene (object individuation) and then encode their details (object identification). Using functional magnetic resonance imaging, two distinctive brain mechanisms were recently identified that support these two stages of visual object processing. While the inferior intraparietal sulcus (IPS) selects a fixed number of about four objects via their spatial locations, the superior IPS and the lateral occipital complex (LOC) encode the features of a subset of the selected objects in great detail (object shapes in this case). Thus, the inferior IPS individuates visual objects from a crowded display and the superior IPS and higher visual areas participate in subsequent object identification. Consistent with the prediction of this theory, even when only object shape identity but not its location is task relevant, this study shows that object individuation in the inferior IPS treats four identical objects similarly as four objects that are all different, whereas object shape identification in the superior IPS and the LOC treat four identical objects as a single unique object. These results provide independent confirmation supporting the dissociation between visual object individuation and identification in the brain.
Saccades to a Remembered Location Elicit Spatially Specific Activation in Human Retinotopic Visual Cortex
Authors: Geng Joy J. , Ruff Christian C. , Driver Jon 
Published: May 2008

AbstractThe possible impact upon human visual cortex from saccades to remembered target locations was investigated using functional magnetic resonance imaging (fMRI). A specific location in the upper-right or upper-left visual quadrant served as the saccadic target. After a delay of 2400 msec, an auditory signal indicated whether to execute a saccade to that location (go trial) or to cancel the saccade and remain centrally fixated (no-go). Group fMRI analysis revealed activation specific to the remembered target location for executed saccades, in the contralateral lingual gyrus. No-go trials produced similar, albeit significantly reduced, effects. Individual retinotopic mapping confirmed that on go trials, quadrant-specific activations arose in those parts of ventral V1, V2, and V3 that coded the target location for the saccade, whereas on no-go trials, only the corresponding parts of V2 and V3 were significantly activated. These results indicate that a spatial–motor saccadic task (i.e., making an eye movement to a remembered location) is sufficient to activate retinotopic visual cortex spatially corresponding to the target location, and that this activation is also present (though reduced) when no saccade is executed. We discuss the implications of finding that saccades to remembered locations can affect early visual cortex, not just those structures conventionally associated with eye movements, in relation to recent ideas about attention, spatial working memory, and the notion that recently activated representations can be “refreshed” when needed.
Structural and Metabolic Correlates of Episodic Memory in Relation to the Depth of Encoding in Normal Aging
Authors: Kalpouzos Grégoria , Chételat Gaël , Landeau Brigitte , Clochon Patrice , Viader Fausto , Eustache Francis , Desgranges Béatrice 
Published: May 2008

AbstractThis study set out to establish the relationship between changes in episodic memory retrieval in normal aging on the one hand and gray matter volume and 18FDG uptake on the other. Structural MRI, resting-state 18FDG-PET, and an episodic memory task manipulating the depth of encoding and the retention interval were administered to 46 healthy subjects divided into three groups according to their age (young, middle-aged, and elderly adults). Memory decline was found not to be linear in the course of normal aging: Whatever the retention interval, the retrieval of shallowly encoded words was impaired in both the middle-aged and the elderly, whereas the retrieval of deeply encoded words only declined in the elderly. In middle-aged and elderly subjects, the reduced performance in the shallow encoding condition was mainly related to posterior mediotemporal volume and metabolism. By contrast, the impaired retrieval of deeply encoded words in the elderly group was mainly related to frontal and parietal regions, suggesting the adoption of inefficient strategic processes.
Development of Spatial and Verbal Working Memory Capacity in the Human Brain
Authors: Thomason Moriah E. , Race Elizabeth , Burrows Brittany , Whitfield-Gabrieli Susan , Glover Gary H. , Gabrieli John D. E. 
Published: May 2008

Abstract
A core aspect of working memory (WM) is the capacity to maintain goal-relevant information in mind, but little is known about how this capacity develops in the human brain. We compared brain activation, via fMRI, between children (ages 7–12 years) and adults (ages 20–29 years) performing tests of verbal and spatial WM with varying amounts (loads) of information to be maintained in WM. Children made disproportionately more errors than adults as WM load increased. Children and adults exhibited similar hemispheric asymmetry in activation, greater on the right for spatial WM and on the left for verbal WM. Children, however, failed to exhibit the same degree of increasing activation across WM loads as was exhibited by adults in multiple frontal and parietal cortical regions. Thus, children exhibited adult-like hemispheric specialization, but appeared immature in their ability to marshal the neural resources necessary to maintain large amounts of verbal or spatial information in WM.
The Common Neural Basis of Autobiographical Memory, Prospection, Navigation, Theory of Mind, and the Default Mode: A Quantitative Meta-analysis
Authors: Spreng R. Nathan , Mar Raymond A. , Kim Alice S. N. 
Published: May 2008

AbstractA core brain network has been proposed to underlie a number of different processes, including remembering, prospection, navigation, and theory of mind [Buckner, R. L., & Carroll, D. C. Self-projection and the brain. Trends in Cognitive Sciences, 11, 49–57, 2007]. This purported network—medial prefrontal, medial-temporal, and medial and lateral parietal regions—is similar to that observed during default-mode processing and has been argued to represent self-projection [Buckner, R. L., & Carroll, D. C. Self-projection and the brain. Trends in Cognitive Sciences, 11, 49–57, 2007] or scene-construction [Hassabis, D., & Maguire, E. A. Deconstructing episodic memory with construction. Trends in Cognitive Sciences, 11, 299–306, 2007]. To date, no systematic and quantitative demonstration of evidence for this common network has been presented. Using the activation likelihood estimation (ALE) approach, we conducted four separate quantitative meta-analyses of neuroimaging studies on: (a) autobiographical memory, (b) navigation, (c) theory of mind, and (d) default mode. A conjunction analysis between these domains demonstrated a high degree of correspondence. We compared these findings to a separate ALE analysis of prospection studies and found additional correspondence. Across all domains, and consistent with the proposed network, correspondence was found within the medial-temporal lobe, precuneus, posterior cingulate, retrosplenial cortex, and the temporo-parietal junction. Additionally, this study revealed that the core network extends to lateral prefrontal and occipital cortices. Autobiographical memory, prospection, theory of mind, and default mode demonstrated further reliable involvement of the medial prefrontal cortex and lateral temporal cortices. Autobiographical memory and theory of mind, previously studied as distinct, exhibited extensive functional overlap. These findings represent quantitative evidence for a core network underlying a variety of cognitive domains.
Compressed Scaling of Abstract Numerosity Representations in Adult Humans and Monkeys
Authors: Merten Katharina , Nieder Andreas 
Published: May 2008

Abstract
There is general agreement that nonverbal animals and humans endowed with language possess an evolutionary precursor system for representing and comparing numerical values. However, whether nonverbal numerical representations in human and nonhuman primates are quantitatively similar and whether linear or logarithmic coding underlies such magnitude judgments in both species remain elusive. To resolve these issues, we tested the numerical discrimination performance of human subjects and two rhesus monkeys (Macaca mulatta) in an identical delayed match-to-numerosity task for a broad range of numerosities from 1 to 30. The results demonstrate a noisy nonverbal estimation system obeying Weber's Law in both species. With average Weber fractions in the range of 0.51 and 0.60, nonverbal numerosity discriminations in humans and monkeys showed similar precision. Moreover, the detailed analysis of the performance distributions exhibited nonlinearly compressed numerosity representations in both primate species. However, the difference between linear and logarithmic scaling was less pronounced in humans. This may indicate a gradual transformation of a logarithmic to linear magnitude scale in human adults as the result of a cultural transformation process during the course of mathematical education.
Behavioural responses of Phasmarhabditis hermaphrodita (Nematoda: Rhabditida) to mucus from potential hosts
Authors: Small Richard , Bradford Claire 
Published: May 2008

AbstractHost recognition behaviours were investigated in the Rhabditid nematode Phasmarhabditis hermaphrodita. Infective juveniles were exposed to mucus samples from mollusc species of varying susceptibility (Arion hortensis agg., Deroceras reticulatum, Tandonia budapestensis, Helix aspersa ,Limax flavus, Limax marginatus). Behavioural responses to the mucus were analysed using video-taped sequences. During contact with the mucus samples, infective juveniles decreased duration and frequency of forward crawling and increased frequency and duration of head thrusting and duration of head waving. Other host recognition behaviours identified included body waving and pushing. Most significant differences in behaviour recorded were between controls and during exposure to mollusc mucus; there were few significant differences between mollusc species. The results suggest that P. hermaphrodita forages by the 'cruise' method until mucus from potential hosts is encountered, but then concentrates its search behaviour, characterised by the decrease in forward crawling. However, there were no recorded behaviours that would differentiate between readily susceptible species and those with low or unknown susceptibility.
Description of Neodiplogaster crenatae sp. n. and N. acaloleptae sp. n. (Nematoda: Diplogastridae) from Japan
Authors: Kubono Takanori , Masuya Hayato , Kanzaki Natsumi 
Published: May 2008

AbstractNeodiplogaster crenatae Kanzaki, Masuya & Kubono sp. n. and N. acaloleptae Kanzaki sp. n. are described and figured. Neodiplogaster crenatae sp. n. was isolated from the bark beetles Scolytoplatypus daimio and S. shogun (Scolytidae) emerging from dead logs of Fagus crenata, and was cultured on Botrytis cinerea growing on malt extract agar. Neodiplogaster crenatae sp. n. has male spicules which are relatively stout and arcuate in lateral view but curved to appear Y-shaped in ventral view; the male tail tip is bifurcate and the female tail is long and tapered. Neodiplogaster crenatae sp. n. appears closest to N. velata but is distinguished from it by spicular morphology and female tail length. Neodiplogaster acaloleptae sp. n. was isolated from the cerambycid beetle Acalolepta luxuriosa and reared on B. cinerea growing on potato dextrose agar. Neodiplogaster acaloleptae sp. n. has a conical male tail with narrow bursa covering the entire tail, smoothly tapered and strongly arcuate male spicules, leaf-shaped gubernaculum with a pointed anterior end, and long female tail with a filiform terminus. The new species is close to N. pinicola, N. piniphili and N. wacheki, but may be distinguished by its long female tail and male gubernaculum shape. The partial SSU and D2/D3 LSU of N. crenatae sp. n. were sequenced and compared with those of other sequenced nematodes, revealing that SSU was closest to those of other diplogastrid species, but that D2/D3 LSU was close to Anisakis spp. Neodiplogaster crenatae sp. n. propagated on a fungal lawn of B. cinerea and ambrosia fungi associating with its carrier beetles, but the nematode did not propagate on bacteria. The main food resource of Neodiplogaster spp. is hypothesised to be fungi.
Evidence for pathotype mixtures on Solanum bulbocastanum in Meloidogyne chitwoodi but not in M. fallax
Authors: Poleij Leo , van der Beek J.G. (Hans) 
Published: May 2008

AbstractVariability for pathogenicity on seven Solanum bulbocastanum clones was studied in a collection of isolates of Meloidogyne chitwoodi and M. fallax from a wide range of geographical origins. Four different pathotypes could be distinguished within M. chitwoodi, while no specialisation was found in M. fallax. Meloidogyne chitwoodi isolates from the USA showed the largest variation; those from Europe belonged to one pathotype. In several M. chitwoodi isolates, the occurrence of pathotype mixtures was verified and for the first time reported in automictic Meloidogyne spp. The infrequently formed egg masses in incompatible isolate-plant genotype combinations were not able to reproduce further on various S. bulbocastanum genotypes, suggesting some stability aspects of the resistance. The occurrence of pathotypes and mixtures of pathotypes requires special attention in breeding programmes as well as in disease management.
Conventional and real-time PCR-based species identification and diversity of potato cyst nematodes (Globodera spp.) from Victoria, Australia
Authors: Nambiar Lila , Cunnington James , Quader Motiul 
Published: May 2008

AbstractPCR (conventional and real-time) and DNA sequence analysis were used to identify species and genotypes of potato cyst nematodes from sites in Victoria, Australia. Only Globodera rostochiensis was detected. Sequence analyses of these isolates of PCN have confirmed the PCR-based results and have revealed the presence of genetically diverse populations in infested fields. However, the sequence variation was not in the diagnostic primer binding sites. The melting peaks, from multiplex real-time PCR analysis, for Globodera pallida and G. rostochiensis were 83.3 and 88.7, respectively. The importance of DNA extraction, PCR and sequence analysis for the molecular identification of PCN is discussed. This study has significant implications for detecting species of PCN in order to monitor/develop control strategies for the PCN of quarantine importance.
A new entomopathogenic nematode, Steinernema colombiense n. sp. (Nematoda: Steinernematidae), from Colombia
Authors: López-Núñez Juan Carlos , Plichta Kathryn , Góngora-Botero Carmenza E. , Stock S. Patricia 
Published: May 2008

Abstract
A new entomopathogenic nematode, Steinernema colombiense n. sp., is described
from Colombia. Morphological, molecular (28S and ITS rDNA sequence data) and
cross-hybridisation studies were used for diagnostics and identification
purposes. In addition, 28S and ITS rDNA sequence data were used to assess
evolutionary relationships of the new species with other Steinernema spp.
Morphological diagnostic features for S. colombiense n. sp. include
morphometric features of the third-stage infective juvenile, including body
length of 636 (549-732) μm, narrow body diam. (31 (22-36) μm), position of
the excretory pore (35 (31-40) μm), tail length (41 (32-53) μm), D% = 29
(25-33) and E% = 205 (138-284). In addition, males of first and second
generations are characterised by the morphology of the spicules and
gubernaculum, the number and arrangement of the genital papillae and the
excretory pore position (at 67 (56-76) and 54 (46-63) μm, for first and
second generations, respectively). In addition to these traits, 28S and ITS
rDNA sequences analyses both showed this species to be a distinct and unique
entity.
Angiopoietin-1 mediates the proangiogenic activity of the bone morphogenic protein antagonist Drm
Authors: Mitola Stefania , Moroni Emanuela , Ravelli Cosetta , Andres German , Belleri Mirella , Presta Marco 
Published: May 2008

Abstract
Recent observations have shown that Drm, a member the Dan family of bone morphogenic protein (BMP) antagonists, induces endothelial cell (EC) sprouting in vitro and angiogenesis in vivo by interacting with signaling EC receptors in a BMP-independent manner. Here, recombinant Drm (rDrm) up-regulates angiopoientin-1 (Ang-1) expression in EC without affecting Ang-2 and Tie-2 receptor expression. Ang-1 up-regulation is mediated by the activation of the transcription factor NF-κB. Specific inhibition of Ang-1 activity by anti–Ang-1 antibodies, soluble Tie-2 receptor, or Ang-1 siRNA transfection significantly reduced the rDrm-mediated sprouting of EC in three-dimensional fibrin and type I collagen gels. In addition, Ang-1 antagonists inhibited the angiogenic activity exerted by rDrm in the chick embryo chorioallantoic membrane. Taken together, the data indicate that the proangiogenic activity of Drm is mediated by the activation of an Ang-1–dependent autocrine loop of stimulation in EC.
Expression, activation, and function of integrin αMβ2 (Mac-1) on neutrophil-derived microparticles
Authors: Pluskota Elzbieta , Woody Neil M. , Szpak Dorota , Ballantyne Christie M. , Soloviev Dmitry A. , Simon Daniel I. , Plow Edward F. 
Published: May 2008

AbstractLeukocyte-derived microparticles (MPs) are markers of cardiovascular diseases and contribute to pathogenesis by their interaction with various cell types. The presence and activation state of a multifunctional leukocyte receptor, integrin αMβ2 (CD11b/18), on MPs derived from human neutrophils (PMNs) were examined. αMβ2 expression was significantly enhanced on MPs derived from stimulated compared with resting PMNs. Furthermore, αMβ2 on MPs from stimulated but not resting PMNs was in an activated conformation because it was capable of binding activation-specific monoclonal antibodies (CBRM1/5 and mAb24) and soluble fibrinogen. MPs expressing active αMβ2 interacted with and were potent activators of resting platelets as assessed by induction of P-selectin expression and activation of αIIbβ3. With the use of function-blocking antibodies and MPs obtained from αM−/−-deficient mice, we found that engagement of GPIbα on platelets by αMβ2 on MPs plays a pivotal role in MP binding. Platelet activation by MPs occurs by a pathway dependent on Akt phosphorylation. PSGL-1/P-selectin interaction also is involved in the conjugation of MPs to platelets, and the combination of blocking reagents to both αMβ2/GPIbα and to PSGL-1/P-selectin completely abrogates MP-induced platelet activation. Thus, cooperation of these 2 receptor/counterreceptor systems regulates the prothrombotic properties of PMN-derived MPs.
c-Cbl expression levels regulate the functional responses of human central and effector memory CD4 T cells
Authors: Brembilla Nicolò C. , Weber Johann , Rimoldi Donata , Pradervand Sylvain , Schütz Frédéric , Pantaleo Giuseppe , Rüegg Curzio , Quadroni Manfredo , Harshman Keith , Doucey Marie-Agnès 
Published: May 2008

Abstract
The biochemical mechanisms controlling the diverse functional outcomes of human central memory (CM) and effector memory (EM) T-cell responses triggered through the T-cell receptor (TCR) remain poorly understood. We implemented reverse phase protein arrays to profile TCR signaling components in human CD8 and CD4 memory T-cell subsets isolated ex vivo. As compared with CD4 CM cells, EM cells express statistically significant increased amounts of SLP-76 and reduced levels of c-Cbl, Syk, Fyn, and LAT. Moreover, in EM cells reduced expression of negative regulator c-Cbl correlates with expression of c-Cbl kinases (Syk and Fyn), PI3K, and LAT. Importantly, consistent with reduced expression of c-Cbl, EM cells display a lower functional threshold than CM cells. Increasing c-Cbl content of EM cells to the same level as that of CM cells using cytosolic transduction, we impaired their proliferation and cytokine production. This regulatory mechanism depends primarily on c-Cbl E3 ubiquitin ligase activity as evidenced by the weaker impact of enzymatically deficient c-Cbl C381A mutant on EM cell functions. Our study reports c-Cbl as a critical regulator of the functional responses of memory T cell subsets and identifies for the first time in humans a mechanism controlling the functional heterogeneity of memory CD4 cells.
Retrovirally induced CTL degranulation mediated by IL-15 expression and infection of mononuclear phagocytes in patients with HTLV-I–associated neurologic disease
Authors: Enose-Akahata Yoshimi , Oh Unsong , Grant Christian , Jacobson Steven 
Published: May 2008

AbstractCD8+ T cells contribute to central nervous system inflammation in human T-cell lymphotropic virus type I (HTLV-I)–associated myelopathy/tropical spastic paraparesis (HAM/TSP). We analyzed CD8+ T-cell dysfunction (degranulation and IFN-γ production) and have demonstrated that CD8+ T cells of patients with HAM/TSP (HAM/TSP patients) spontaneously degranulate and express IFN-γ in ex vivo unstimulated culture. CD8+ T cells of HTLV-I asymptomatic carriers and healthy donors did not. Spontaneous degranulation was detected in Tax11-19/HLA-A*201 tetramer+ cells, but not in CMV pp65 tetramer+ cells. Interestingly, degranulation and IFN-γ production in CD8+ T cells was induced by coculture with autologous CD14+ cells, but not CD4+ T cells, of HAM/TSP patients, which correlated with proviral DNA load in CD14+ cells of infected patients. Moreover, the expression of IL-15, which induced degranulation and IFN-γ production in infected patients, was enhanced on surface of CD14+ cells in HAM/TSP patients. Blockade of MHC class I and IL-15 confirmed these results. Thus, CD8+ T-cell dysregulation was mediated by both virus infection and enhanced IL-15 on CD14+ cells in HAM/TSP patients. Despite lower viral expression than in CD4+ T cells, HTLV-I–infected or –activated CD14+ cells may be a heretofore important but under recognized reservoir particularly in HAM/TSP patients.