33 results on '"Chiou R"'
Search Results
2. Acquisition of JAK2, PTPN11, and RAS mutations during disease progression in primary myelodysplastic syndrome
- Author
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Chen, C-Y, Lin, L-I, Tang, J-L, Tsay, W, Chang, H-H, Yeh, Y-C, Huang, C-F, Chiou, R-J, Yao, M, Ko, B-S, Chen, Y-C, Lin, K-H, Lin, D-T, and Tien, H-F
- Published
- 2006
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3. Modelling the effect of flank wear on machining thrust stability
- Author
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Liang, S. Y., Kwon, Y. K., and Chiou, R. Y.
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- 2004
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4. Antioxidative characteristics of oils in ground pork-fat patties cooked with soy sauce
- Author
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Chiou, R. Y. -Y., Ku, K. -L., Lai, Y. -S., and Chang, L. -G.
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- 2001
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5. Sensory dynamics of visual hallucinations in the normal population
- Author
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Pearson, J, Chiou, R, Rogers, S, Wicken, M, Heitmann, S, Ermentrout, B, Pearson, J, Chiou, R, Rogers, S, Wicken, M, Heitmann, S, and Ermentrout, B
- Abstract
© Pearson et al. Hallucinations occur in both normal and clinical populations. Due to their unpredictability and complexity, the mechanisms underlying hallucinations remain largely untested. Here we show that visual hallucinations can be induced in the normal population by visual flicker, limited to an annulus that constricts content complexity to simple moving grey blobs, allowing objective mechanistic investigation. Hallucination strength peaked at ~11 Hz flicker and was dependent on cortical processing. Hallucinated motion speed increased with flicker rate, when mapped onto visual cortex it was independent of eccentricity, underwent local sensory adaptation and showed the same bistable and mnemonic dynamics as sensory perception. A neural field model with motion selectivity provides a mechanism for both hallucinations and perception. Our results demonstrate that hallucinations can be studied objectively, and they share multiple mechanisms with sensory perception. We anticipate that this assay will be critical to test theories of human consciousness and clinical models of hallucination.
- Published
- 2016
6. How does the brain integrate banana with yellowness: The neural architecture of object colour knowledge requires left anterior temporal lobe
- Author
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Chiou, R., primary, Sowman, P. F., additional, Etchell, A. C., additional, and Rich, A. N., additional
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- 2013
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7. Characterization of acute myeloid leukemia with PTPN11 mutation: the mutation is closely associated with NPM1 mutation but inversely related to FLT3/ITD
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Hou, H-A, primary, Chou, W-C, additional, Lin, L-I, additional, Chen, C-Y, additional, Tang, J-L, additional, Tseng, M-H, additional, Huang, C-F, additional, Chiou, R-J, additional, Lee, F-Y, additional, Liu, M-C, additional, and Tien, H-F, additional
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- 2007
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8. Ethanol-Mediated Variations in Cellular Fatty Acid Composition and Protein Profiles of Two Genotypically Different Strains of Escherichia coli O157:H7
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Chiou, R. Y.-Y., primary, Phillips, R. D., additional, Zhao, P., additional, Doyle, M. P., additional, and Beuchat, L. R., additional
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- 2004
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9. Estimation of fungal infection of peanut kernels by determination of free glutamic Acid content
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Chiou, R Y, primary
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- 1997
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10. α-Carbonyl radicals for total synthesis of natural products
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Sha, C.-K., primary, Jean, T.-S., additional, Yau, N.-T., additional, Huang, S.-J., additional, Chiou, R.-T., additional, Young, J.-F., additional, Lih, S.-H., additional, and Tseng, W.-H., additional
- Published
- 1996
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11. Comparative effect of famotidine and cimetidine on the pharmacokinetics of theophylline in normal volunteers.
- Author
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Lin, JH, Chremos, AN, Chiou, R, Yeh, KC, and Williams, R
- Abstract
The comparative effect of famotidine or cimetidine on theophylline disposition was determined in healthy volunteers. Cimetidine, but not famotidine, caused a reduction in the rate of elimination of theophylline. The mean total body clearance of theophylline was reduced from 57.6 ml min-1 before cimetidine to 39.5 ml min-1 during cimetidine; and the half-life was prolonged from 8.7 h before cimetidine to 12 h during cimetidine. The volume of distribution and renal excretion of theophylline were not affected by either famotidine or cimetidine. [ABSTRACT FROM AUTHOR]
- Published
- 1987
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12. Analysis of acoustic emission in chatter vibration with tool wear effect in turning
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Chiou, R. Y. and Liang, S. Y.
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- 2000
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13. Effect of dietary organic arsenicals and cupric sulfate on copper toxicity, liver accumulation and residue in eggs and excreta of laying hens
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Chiou, R. Wen-Shyg, Chen, K.-L., and Yu, B.
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- 1998
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14. Chatter stability of a slender cutting tool in turning with tool wear effect
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Chiou, R. Y. and Liang, S. Y.
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- 1998
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15. Supplementary health benefits of soy aglycons of isoflavone by improvement of serum biochemical attributes, enhancement of liver antioxidative capacities and protection of vaginal epithelium of ovariectomized rats
- Author
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Lo Dan-Yuan, Hsu Yu-Lin, Lien Tu-Fa, and Chiou Robin YY
- Subjects
Nutrition. Foods and food supply ,TX341-641 ,Nutritional diseases. Deficiency diseases ,RC620-627 - Abstract
Abstract Background In the literature, supplement of soy aglycons of isoflavone as estrogen agonists in improvement of serum biochemical attributes, liver antioxidative capacities and vaginal epithelium protection has been meagerly investigated. In this study, ovariectomized (OVX) rats were used as an animal model to simulate post-menopausal status. Supplementary health benefits of soy aglycons of isoflavone (SAI) on improvement of growth and serum biochemical attributes, enhancement of liver antioxidation-related capacities and protection of vaginal epithelium of the OVX rats were assessed. Methods As an in vivo study, 30 OVX Sprague-Dawley rats were distributed into OVX (positive control), OVX/LSAI (low SAI group – supplemented with 0.0135% SAI being equivalent to 80 mg per day for a 60 Kg-human), and OVX/HSAI (high SAI group – supplemented with 0.027% SAI) and 10 rats with sham operation as negative control fed with basal diet. Results The average daily gain (ADG), feed intake and feed/gain ratio were higher for the OVX groups than the sham group (P < 0.05). Serum isoflavone concentrations of the OVX rats were increased by SAI supplementation. In comparison, significantly lower serum cholesterol and LDL (low-density lipoprotein) levels, and higher HDL (high-density lipoprotein) levels were detected for the rats of OVX/HSAI group (P < 0.05). SAI supplementation also increased iron chelating ability and decreased values of TBARS (thiobarbituric acid-reactive substance) (P < 0.05) of liver extracts. Liver catalase activity and total antioxidative activity (trolox equivalency) were enhanced by HSAI supplementation (P < 0.05). Decrease of vagina epithelial cellular linings of the OVX rats were noticeably improved by dietary supplementation with SAI. Conclusion Diets supplemented with soy aglycons of isoflavone have conferred health benefits to the OVX rats, in comparison to the sham rats fed with basal diet, by detection of higher serum isoflavone concentrations, significantly lower contents of serum cholesterol and LDL, and higher contents of serum HDL, increased iron chelating ability, lower contents of TBARS (thiobarbituric acid-reactive substance) and enhanced catalase and total antioxidative (as trolox equivalency) activities of the liver extracts, and protection of the epithelial cellular linings of vagina in the former rather than in the latter. This evidences that estrogen-agonist chemoprevention of menopausal-related cardiovascular diseases, decreased liver antioxidative capacities and epithelial degeneration of vagina could be achieved by dietary supplementation with soy aglycons of isoflavone.
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- 2009
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16. The dimensionality of neural coding for cognitive control is gradually transformed within the lateral prefrontal cortex.
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Chiou R, Duncan J, Jefferies E, and Lambon Ralph MA
- Abstract
Implementing cognitive control relies on neural representations that are inherently high-dimensional and distributed across multiple subregions in the prefrontal cortex (PFC). Traditional approaches tackle prefrontal representation by reducing it into a unidimensional measure (univariate amplitude) or using them to distinguish a limited number of alternatives (pattern classification). By contrast, representational similarity analysis (RSA) enables flexibly formulating various hypotheses about informational contents underlying the neural codes, explicitly comparing hypotheses, and examining the representational alignment between brain regions. Here, we used a multifaceted paradigm wherein the difficulty of cognitive control was manipulated separately for five cognitive tasks. We used RSA to unveil representational contents, measure the representational alignment between regions, and quantify representational generality vs. specificity. We found a graded transition in the lateral PFC: The dorsocaudal PFC was tuned to task difficulty (indexed by reaction times), preferentially connected with the parietal cortex, and representationally generalisable across domains. The ventrorostral PFC was tuned to the abstract structure of tasks, preferentially connected with the temporal cortex, and representationally specific. The middle PFC (interposed between dorsocaudal and ventrorostral PFC) was tuned to individual task-sets, ranked in the middle in terms of connectivity and generalisability. Furthermore, whether a region was dimensionally rich or sparse co-varied with its functional profile: Low dimensionality (only gist) in the dorsocaudal PFC dovetailed with better generality, whereas high dimensionality (gist plus details) in the ventrorostral PFC corresponded with better ability to encode subtleties. Our findings, collectively, demonstrate how cognitive control is decomposed into distinct facets that transition steadily along prefrontal subregions. Significance statement Cognitive control is known to be a high-dimensional construct, implemented along the dorsocaudal-ventrorostral subregions of PFC. However, it remains unclear how prefrontal representations could be dissected in a multivariate fashion to reveal (1) what information is encoded in each subregion, (2) whether information systematically transforms across contiguous PFC subregions as a gradient, (3) how this transformation is affected by functional connectivity. Here we shed light on these issues by using RSA to decode informational composition in the PFC while using participant-specific localisers to facilitate individually-tailored precision. Our findings elucidate the functional organisation of PFC by revealing how a trade-off between dimensionality and generalisability unfolds in the PFC and highlight the strength of RSA in deciphering the coding of cognitive control., (Copyright © 2024 the authors.)
- Published
- 2024
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17. A function-based mapping of sensory integration along the cortical hierarchy.
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Wei W, Benn RA, Scholz R, Shevchenko V, Klatzmann U, Alberti F, Chiou R, Wassermann D, Vanderwal T, Smallwood J, and Margulies DS
- Subjects
- Humans, Male, Adult, Female, Cerebral Cortex physiology, Cerebral Cortex diagnostic imaging, Young Adult, Sensation physiology, Magnetic Resonance Imaging, Brain Mapping methods, Cognition physiology
- Abstract
Sensory information mainly travels along a hierarchy spanning unimodal to transmodal regions, forming multisensory integrative representations crucial for higher-order cognitive functions. Here, we develop an fMRI based two-dimensional framework to characterize sensory integration based on the anchoring role of the primary cortex in the organization of sensory processing. Sensory magnitude captures the percentage of variance explained by three primary sensory signals and decreases as the hierarchy ascends, exhibiting strong similarity to the known hierarchy and high stability across different conditions. Sensory angle converts associations with three primary sensory signals to an angle representing the proportional contributions of different sensory modalities. This dimension identifies differences between brain states and emphasizes how sensory integration changes flexibly in response to varying cognitive demands. Furthermore, meta-analytic functional decoding with our model highlights the close relationship between cognitive functions and sensory integration, showing its potential for future research of human cognition through sensory information processing., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)
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- 2024
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18. A middle ground where executive control meets semantics: the neural substrates of semantic control are topographically sandwiched between the multiple-demand and default-mode systems.
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Chiou R, Jefferies E, Duncan J, Humphreys GF, and Lambon Ralph MA
- Subjects
- Humans, Magnetic Resonance Imaging, Cognition physiology, Language, Brain Mapping, Executive Function physiology, Semantics
- Abstract
Semantic control is the capability to operate on meaningful representations, selectively focusing on certain aspects of meaning while purposefully ignoring other aspects based on one's behavioral aim. This ability is especially vital for comprehending figurative/ambiguous language. It remains unclear why and how regions involved in semantic control seem reliably juxtaposed alongside other functionally specialized regions in the association cortex, prompting speculation about the relationship between topography and function. We investigated this issue by characterizing how semantic control regions topographically relate to the default-mode network (associated with memory and abstract cognition) and multiple-demand network (associated with executive control). Topographically, we established that semantic control areas were sandwiched by the default-mode and multi-demand networks, forming an orderly arrangement observed both at the individual and group level. Functionally, semantic control regions exhibited "hybrid" responses, fusing generic preferences for cognitively demanding operation (multiple-demand) and for meaningful representations (default-mode) into a domain-specific preference for difficult operation on meaningful representations. When projected onto the principal gradient of human connectome, the neural activity of semantic control showed a robustly dissociable trajectory from visuospatial control, implying different roles in the functional transition from sensation to cognition. We discuss why the hybrid functional profile of semantic control regions might result from their intermediate topographical positions on the cortex., (© The Author(s) 2022. Published by Oxford University Press.)
- Published
- 2023
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19. Bipartite functional fractionation within the neural system for social cognition supports the psychological continuity of self versus other.
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Chiou R, Cox CR, and Lambon Ralph MA
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- Humans, Brain Mapping methods, Social Cognition, Nerve Net, Neural Pathways, Magnetic Resonance Imaging methods, Cognition, Brain diagnostic imaging, Connectome
- Abstract
Research of social neuroscience establishes that regions in the brain's default-mode network (DN) and semantic network (SN) are engaged by socio-cognitive tasks. Research of the human connectome shows that DN and SN regions are both situated at the transmodal end of a cortical gradient but differ in their loci along this gradient. Here we integrated these 2 bodies of research, used the psychological continuity of self versus other as a "test-case," and used functional magnetic resonance imaging to investigate whether these 2 networks would encode social concepts differently. We found a robust dissociation between the DN and SN-while both networks contained sufficient information for decoding broad-stroke distinction of social categories, the DN carried more generalizable information for cross-classifying across social distance and emotive valence than did the SN. We also found that the overarching distinction of self versus other was a principal divider of the representational space while social distance was an auxiliary factor (subdivision, nested within the principal dimension), and this representational landscape was more manifested in the DN than in the SN. Taken together, our findings demonstrate how insights from connectome research can benefit social neuroscience and have implications for clarifying the 2 networks' differential contributions to social cognition., (© The Author(s) 2022. Published by Oxford University Press.)
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- 2023
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20. Distinct and common neural coding of semantic and non-semantic control demands.
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Gao Z, Zheng L, Chiou R, Gouws A, Krieger-Redwood K, Wang X, Varga D, Ralph MAL, Smallwood J, and Jefferies E
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- Adult, Brain Mapping, Cerebral Cortex diagnostic imaging, Female, Humans, Magnetic Resonance Imaging, Male, Nerve Net diagnostic imaging, Pattern Recognition, Visual physiology, Reading, Semantics, Support Vector Machine, Verbal Learning physiology, Young Adult, Association, Cerebral Cortex physiology, Executive Function physiology, Memory, Short-Term physiology, Nerve Net physiology
- Abstract
The flexible retrieval of knowledge is critical in everyday situations involving problem solving, reasoning and social interaction. Current theories emphasise the importance of a left-lateralised semantic control network (SCN) in supporting flexible semantic behaviour, while a bilateral multiple-demand network (MDN) is implicated in executive functions across domains. No study, however, has examined whether semantic and non-semantic demands are reflected in a common neural code within regions specifically implicated in semantic control. Using functional MRI and univariate parametric modulation analysis as well as multivariate pattern analysis, we found that semantic and non-semantic demands gave rise to both similar and distinct neural responses across control-related networks. Though activity patterns in SCN and MDN could decode the difficulty of both semantic and verbal working memory decisions, there was no shared common neural coding of cognitive demands in SCN regions. In contrast, regions in MDN showed common patterns across manipulations of semantic and working memory control demands, with successful cross-classification of difficulty across tasks. Therefore, SCN and MDN can be dissociated according to the information they maintain about cognitive demands., Competing Interests: Declaration of Competing Interest The authors declare no competing financial interests., (Copyright © 2021. Published by Elsevier Inc.)
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- 2021
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21. Bipartite Functional Fractionation within the Default Network Supports Disparate Forms of Internally Oriented Cognition.
- Author
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Chiou R, Humphreys GF, and Lambon Ralph MA
- Subjects
- Adult, Brain Mapping, Female, Humans, Magnetic Resonance Imaging, Male, Memory physiology, Psychophysics, Semantics, Young Adult, Brain physiology, Cognition physiology, Default Mode Network physiology
- Abstract
Our understanding about the functionality of the brain's default network (DN) has significantly evolved over the past decade. Whereas traditional views define this network based on its suspension/disengagement during task-oriented behavior, contemporary accounts have characterized various situations wherein the DN actively contributes to task performance. However, it is unclear how different task-contexts drive componential regions of the DN to coalesce into a unitary network and fractionate into different subnetworks. Here we report a compendium of evidence that provides answers to these questions. Across multiple analyses, we found a striking dyadic structure within the DN in terms of the profiles of task-triggered fMRI response and effective connectivity, significantly extending beyond previous inferences based on meta-analysis and resting-state activities. In this dichotomy, one subset of DN regions prefers mental activities "interfacing with" perceptible events, while the other subset prefers activities "detached from" perceptible events. While both show a common "aversion" to sensory-motoric activities, their differential preferences manifest a subdivision that sheds light upon the taxonomy of the brain's memory systems. This dichotomy is consistent with proposals of a macroscale gradational structure spanning across the cerebrum. This gradient increases its representational complexity, from primitive sensory-motoric processing, through lexical-semantic representations, to elaborated self-generated thoughts., (© The Author(s) 2020. Published by Oxford University Press.)
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- 2020
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22. Sensory dynamics of visual hallucinations in the normal population.
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Pearson J, Chiou R, Rogers S, Wicken M, Heitmann S, and Ermentrout B
- Subjects
- Humans, Models, Neurological, Hallucinations, Visual Cortex physiology
- Abstract
Hallucinations occur in both normal and clinical populations. Due to their unpredictability and complexity, the mechanisms underlying hallucinations remain largely untested. Here we show that visual hallucinations can be induced in the normal population by visual flicker, limited to an annulus that constricts content complexity to simple moving grey blobs, allowing objective mechanistic investigation. Hallucination strength peaked at ~11 Hz flicker and was dependent on cortical processing. Hallucinated motion speed increased with flicker rate, when mapped onto visual cortex it was independent of eccentricity, underwent local sensory adaptation and showed the same bistable and mnemonic dynamics as sensory perception. A neural field model with motion selectivity provides a mechanism for both hallucinations and perception. Our results demonstrate that hallucinations can be studied objectively, and they share multiple mechanisms with sensory perception. We anticipate that this assay will be critical to test theories of human consciousness and clinical models of hallucination., Competing Interests: The authors declare that no competing interests exist.
- Published
- 2016
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23. Task-Related Dynamic Division of Labor Between Anterior Temporal and Lateral Occipital Cortices in Representing Object Size.
- Author
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Chiou R and Lambon Ralph MA
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- Adult, Brain Mapping, Female, Humans, Magnetic Resonance Imaging, Male, Photic Stimulation, Theta Rhythm physiology, Transcranial Magnetic Stimulation methods, Visual Cortex physiology, Occipital Lobe physiology, Pattern Recognition, Visual physiology, Temporal Lobe physiology, Visual Pathways physiology
- Abstract
Unlabelled: Object size is represented by functionally distinct sectors along the ventral visual pathway. The early visual cortex encodes objects' sensory-retinal size. Subsequently, the occipitotemporal cortex computes objects' canonical size based on statistical regularities of visual features. Although the neurocomputation of size has been studied in a "bottom-up" sensory-driven framework, little is known about how perceptual size information is transformed into conceptual knowledge and how this computation is modulated by "top-down" goal-driven signals. Using continuous theta burst stimulation, we demonstrated that behavioral goal shapes the neurocognitive network underpinning object size. We manipulated the congruency of perceptual versus conceptual object size, which provides a robust behavioral probe reflecting implicit size knowledge. Neurostimulation was targeted at the lateral occipital cortex (LOC), a key region for object perception, or the anterior temporal lobe (ATL), a "hub" of supramodal conceptual processing. We observed striking contextual modulation of the neurocognitive architecture: when human participants judged perceptual size, the congruency effect was significantly attenuated by LOC stimulation but stayed resilient to ATL stimulation. By contrast, when they judged conceptual size, both LOC and ATL stimulation eradicated the otherwise robust effect. Our findings demonstrate disparate functional profiles of the LOC and ATL, providing the first evidence of a malleable network adaptively altering its division of labor with top-down states. The LOC, regardless of task demand, automatically represents "bottom-up" statistical regularities of visual conformation (reflecting typical object size), whereas the ATL contributes to this computation when the context requires semantically based linkage of visual attributes to object recognition., Significance Statement: In the present study, we provide compelling evidence that the "top-down" cognitive state of an observer changes the dynamic interaction between different subregions of the ventral temporal cortex. Using inhibitory neurostimulation combined with a novel paradigm, we demonstrate a flexible division of labor in the neurocognitive architecture that underpins size knowledge: the lateral occipital cortex codes perceptually based aspects (statistical visual configuration of small/large objects), whereas the anterior temporal lobe represents semantically based aspects (object identity), with their involvement interactively weighted by task demand. The interactive nature of the ventral temporal cortex highlights how top-down modulation constrains and shapes neural representations in the visual system., (Copyright © 2016 Chiou and Lambon Ralph.)
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- 2016
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24. Dynamic changes in intracellular ROS levels regulate airway basal stem cell homeostasis through Nrf2-dependent Notch signaling.
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Paul MK, Bisht B, Darmawan DO, Chiou R, Ha VL, Wallace WD, Chon AT, Hegab AE, Grogan T, Elashoff DA, Alva-Ornelas JA, and Gomperts BN
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- Animals, Antioxidants metabolism, Cell Cycle, Cell Differentiation, Cell Proliferation, Homeostasis, Humans, Mice, Oxidation-Reduction, Polidocanol, Polyethylene Glycols chemistry, Signal Transduction, Wound Healing, NF-E2-Related Factor 2 metabolism, Reactive Oxygen Species metabolism, Receptors, Notch metabolism, Stem Cells cytology, Trachea cytology
- Abstract
Airways are exposed to myriad environmental and damaging agents such as reactive oxygen species (ROS), which also have physiological roles as signaling molecules that regulate stem cell function. However, the functional significance of both steady and dynamically changing ROS levels in different stem cell populations, as well as downstream mechanisms that integrate ROS sensing into decisions regarding stem cell homeostasis, are unclear. Here, we show in mouse and human airway basal stem cells (ABSCs) that intracellular flux from low to moderate ROS levels is required for stem cell self-renewal and proliferation. Changing ROS levels activate Nrf2, which activates the Notch pathway to stimulate ABSC self-renewal and an antioxidant program that scavenges intracellular ROS, returning overall ROS levels to a low state to maintain homeostatic balance. This redox-mediated regulation of lung stem cell function has significant implications for stem cell biology, repair of lung injuries, and diseases such as cancer., (Copyright © 2014 Elsevier Inc. All rights reserved.)
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- 2014
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25. A conceptual lemon: theta burst stimulation to the left anterior temporal lobe untangles object representation and its canonical color.
- Author
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Chiou R, Sowman PF, Etchell AC, and Rich AN
- Subjects
- Adult, Color, Female, Humans, Male, Young Adult, Color Perception physiology, Photic Stimulation methods, Temporal Lobe physiology, Theta Rhythm physiology, Transcranial Magnetic Stimulation methods
- Abstract
Object recognition benefits greatly from our knowledge of typical color (e.g., a lemon is usually yellow). Most research on object color knowledge focuses on whether both knowledge and perception of object color recruit the well-established neural substrates of color vision (the V4 complex). Compared with the intensive investigation of the V4 complex, we know little about where and how neural mechanisms beyond V4 contribute to color knowledge. The anterior temporal lobe (ATL) is thought to act as a "hub" that supports semantic memory by integrating different modality-specific contents into a meaningful entity at a supramodal conceptual level, making it a good candidate zone for mediating the mappings between object attributes. Here, we explore whether the ATL is critical for integrating typical color with other object attributes (object shape and name), akin to its role in combining nonperceptual semantic representations. In separate experimental sessions, we applied TMS to disrupt neural processing in the left ATL and a control site (the occipital pole). Participants performed an object naming task that probes color knowledge and elicits a reliable color congruency effect as well as a control quantity naming task that also elicits a cognitive congruency effect but involves no conceptual integration. Critically, ATL stimulation eliminated the otherwise robust color congruency effect but had no impact on the numerical congruency effect, indicating a selective disruption of object color knowledge. Neither color nor numerical congruency effects were affected by stimulation at the control occipital site, ruling out nonspecific effects of cortical stimulation. Our findings suggest that the ATL is involved in the representation of object concepts that include their canonical colors.
- Published
- 2014
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26. The role of conceptual knowledge in understanding synaesthesia: Evaluating contemporary findings from a "hub-and-spokes" perspective.
- Author
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Chiou R and Rich AN
- Abstract
Synesthesia is a phenomenon in which stimulation in one sensory modality triggers involuntary experiences typically not associated with that stimulation. Inducing stimuli (inducers) and synesthetic experiences (concurrents) may occur within the same modality (e.g., seeing colors while reading achromatic text) or span across different modalities (e.g., tasting flavors while listening to music). Although there has been considerable progress over the last decade in understanding the cognitive and neural mechanisms of synesthesia, the focus of current neurocognitive models of synesthesia does not encompass many crucial psychophysical characteristics documented in behavioral research. Prominent theories of the neurophysiological basis of synesthesia construe it as a perceptual phenomenon and hence focus primarily on the modality-specific brain regions for perception. Many behavioral studies, however, suggest an essential role for conceptual-level information in synesthesia. For example, there is evidence that synesthetic experience arises subsequent to identification of an inducing stimulus, differs substantially from real perceptual events, can be akin to perceptual memory, and is susceptible to lexical/semantic contexts. These data suggest that neural mechanisms lying beyond the realm of the perceptual cortex (especially the visual system), such as regions subserving conceptual knowledge, may play pivotal roles in the neural architecture of synesthesia. Here we discuss the significance of non-perceptual mechanisms that call for a re-evaluation of the emphasis on synesthesia as a perceptual phenomenon. We also review recent studies which hint that some aspects of synesthesia resemble our general conceptual knowledge for object attributes, at both psychophysical and neural levels. We then present a conceptual-mediation model of synesthesia in which the inducer and concurrent are linked within a conceptual-level representation. This "inducer-to-concurrent" nexus is maintained within a supramodal "hub," while the subjective (bodily) experience of its resultant concurrent (e.g., a color) may then require activation of "spokes" in the perception-related cortices. This hypothesized "hub-and-spoke" structure would engage a distributed network of cortical regions and may account for the full breadth of this intriguing phenomenon.
- Published
- 2014
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27. Biocompatibility and biodegradation studies of PCL/β-TCP bone tissue scaffold fabricated by structural porogen method.
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Lu L, Zhang Q, Wootton D, Chiou R, Li D, Lu B, Lelkes P, and Zhou J
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- Animals, Biocompatible Materials chemical synthesis, Biocompatible Materials chemistry, Bone Substitutes chemistry, Bone and Bones drug effects, Bone and Bones physiology, Calcium Phosphates chemical synthesis, Cells, Cultured, Computer Simulation, Feasibility Studies, Humans, Materials Testing, Mice, Osseointegration drug effects, Osseointegration physiology, Polyesters chemical synthesis, Porosity, Tissue Engineering instrumentation, Absorbable Implants, Bone Substitutes chemical synthesis, Calcium Phosphates chemistry, Polyesters chemistry, Tissue Engineering methods, Tissue Scaffolds chemistry
- Abstract
Three-dimensional printer (3DP) (Z-Corp) is a solid freeform fabrication system capable of generating sub-millimeter physical features required for tissue engineering scaffolds. By using plaster composite materials, 3DP can fabricate a universal porogen which can be injected with a wide range of high melting temperature biomaterials. Here we report results toward the manufacture of either pure polycaprolactone (PCL) or homogeneous composites of 90/10 or 80/20 (w/w) PCL/beta-tricalcium phosphate (β-TCP) by injection molding into plaster composite porogens fabricated by 3DP. The resolution of printed plaster porogens and produced scaffolds was studied by scanning electron microscopy. Cytotoxicity test on scaffold extracts and biocompatibility test on the scaffolds as a matrix supporting murine osteoblast (7F2) and endothelial hybridoma (EAhy 926) cells growth for up to 4 days showed that the porogens removal process had only negligible effects on cell proliferation. The biodegradation tests of pure PCL and PCL/β-TCP composites were performed in DMEM with 10 % (v/v) FBS for up to 6 weeks. The PCL/β-TCP composites show faster degradation rate than that of pure PCL due to the addition of β-TCP, and the strength of 80/20 PCL/β-TCP composite is still suitable for human cancellous bone healing support after 6 weeks degradation. Combining precisely controlled porogen fabrication structure, good biocompatibility, and suitable mechanical properties after biodegradation, PCL/β-TCP scaffolds fabricated by 3DP porogen method provide essential capability for bone tissue engineering.
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- 2012
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28. Survival of staphylococcus aureus and Escherichia coli as affected by ethanol and NaCl.
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Huang SL, Weng YM, and Chiou RY
- Subjects
- Escherichia coli growth & development, Staphylococcus aureus growth & development, Time Factors, Escherichia coli drug effects, Ethanol pharmacology, Sodium Chloride pharmacology, Staphylococcus aureus drug effects
- Abstract
Growth of three strains of Staphylococcus aureus and two strains of Escherichia coli on nutrient agar (NA) supplemented with ethanol and NaCl was investigated. S. aureus did not grow on NA containing > or =10% ethanol (wt/wt) combined with > or =0% NaCl (wt/wt), or 7.5% ethanol combined with 7.5% NaCl. Neither E. coli nor E. coli O157:H7 grew on NA containing > or =7.5% ethanol combined with > or =0% NaCl, 5% ethanol combined with > or =2.5% NaCl, or > or =5% NaCl combined with > or =0% ethanol. It is apparent that NaCl enhanced the inhibitory effect of ethanol on growth of S. aureus and E. coli When cells were suspended in nutrient broth containing 12.5, 20, or 40% ethanol combined with NaCl, viable cells decreased with an increase of ethanol concentration. Ethanol sensitivity among strains and between genera varied in a limited range. When the cells were exposed to 20% ethanol in combination with 5% NaCl, S. aureus and E. coli lost viability after 30 and 10 min, respectively. When treated with 40% ethanol combined with > or =0% NaCl, all test strains lost viability within 5 min.
- Published
- 2001
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29. Comparative evaluation of methods for estimating potential human exposure to ozone: photochemical modeling and ambient monitoring.
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Georgopoulos PG, Purushothaman V, and Chiou R
- Subjects
- Humans, Mid-Atlantic Region, Models, Theoretical, Population Density, Weather, Air Pollutants analysis, Environmental Monitoring methods, Oxidants, Photochemical analysis, Ozone analysis
- Abstract
Photochemical modeling and ambient monitoring of ground-level ozone concentrations provide two alternative/complementary methods for calculating potential population exposure estimates. A comparative evaluation of these methods was undertaken over a study area comprised of the entire state of New Jersey and neighboring parts of Delaware, Maryland, Pennsylvania, and New York. Kriging, a geostatistical interpolation technique, was used for the interpolation of hourly ozone data from 38 air quality monitoring stations operating within the study area, to derive concentration fields for the entire domain. The Urban Airshed Model (UAM-IV), a comprehensive photochemical grid-based model, was then used to calculate the same concentrations from emissions and meteorology inputs. Concentration fields, thus developed, were linked with corresponding population data to calculate potential population exposure estimates to outdoor ozone (Ep.o). The adequacy of kriging as an interpolation technique was evaluated by comparing Ep.o estimates derived via photochemical UAM modeling with those calculated by using concentrations obtained from kriging UAM-calculated values at the locations of the monitoring stations. In general, UAM was found to predict higher Ep.o compared to those derived by kriging observations. In order to test the robustness of the interpolation methodology with respect to assumptions of statistical correlation, two different semivariogram models, spherical and exponential, were used for kriging. Application of the different semivariograms yielded almost identical Ep.o patterns.
- Published
- 1997
30. Radiolabeled iododeoxyuridine: safety evaluation.
- Author
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Harrison KA, Dalrymple GV, Baranowska-Kortylewicz J, Holdeman KP, Schneiderman MH, Lieberman RP, Sharp JG, Cohen SM, Leichner PK, Augustine SC, Tempero MA, Taylor RJ, and Chiou RK
- Subjects
- Administration, Intravesical, Animals, Female, Humans, Idoxuridine administration & dosage, Idoxuridine therapeutic use, Injections, Intra-Arterial, Iodine Radioisotopes administration & dosage, Iodine Radioisotopes therapeutic use, Liver Neoplasms radiotherapy, Liver Neoplasms secondary, Male, Swine, Urinary Bladder Neoplasms radiotherapy, Idoxuridine toxicity, Iodine Radioisotopes toxicity
- Abstract
Unlabelled: The emphasis of radiolabeled iododeoxyuridine (*IUdR) research at our institution to date has been to assess its safety as a potential therapeutic agent. Toward this goal, we have performed preclinical and clinical studies, using various routes of administration, to detect adverse changes in normal tissues in both humans and animals. As IUdR is rapidly dehalogenated by the liver, the intravenous route is unlikely to be successful in therapeutic efforts. We have therefore focused our attention on more "protected" routes: intra-arterial and intravesicular administration., Methods: Studies were performed in farm pigs after multiple administrations of [125I]IUdR into the aorta, carotid artery and bladder. IUdR and metabolites were measured in venous blood samples at appropriate time intervals after administration, after which histologic examination of tissues was performed. Studies in human have been performed after intra-arterial administration of [123I]IUdR in patients with liver metastases and intravesicular administration in patients with bladder carcinoma, initially using [123I]IUdR and currently using both [123I]IUdR and [125I]IUdR. Blood samples for pharmacokinetics and metabolite analysis and tissue for autoradiography (when feasible) have been obtained., Results: To date, no evidence of adverse effects on normal tissue or alteration of hematologic or metabolic indices have been seen in pigs or humans. When instilled in the bladder, there is little leakage of IUdR in the circulation., Conclusion: When [125I]IUdR is used as a therapeutic agent, we anticipate little or no effect on normal tissues.
- Published
- 1996
31. Localization of human renal cell carcinoma xenografts with a tumor-preferential monoclonal antibody.
- Author
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Chiou RK, Vessella RL, Elson MK, Clayman RV, Gonzalez-Campoy JM, Klicka MJ, Shafer RB, and Lange PH
- Subjects
- Animals, Carcinoma, Renal Cell immunology, Dose-Response Relationship, Immunologic, Humans, Immunologic Techniques, Inflammation immunology, Kidney Neoplasms immunology, Mice, Mice, Nude, Neoplasm Transplantation, Radionuclide Imaging, Tissue Distribution, alpha-Fetoproteins immunology, Antibodies, Monoclonal, Carcinoma, Renal Cell diagnostic imaging, Kidney Neoplasms diagnostic imaging
- Abstract
We previously described an immunoglobulin G1 monoclonal antibody (UMVA-RCC-A6H) that is highly reactive with human renal cell carcinoma (RCC) and has little cross-reactivity to other cell types both normal and malignant. In efforts detailed herein, radiolabeled A6H selectively localized to RCC xenografts and provided high resolution images of the xenografts. Also, A6H clearly discriminated between RCC xenografts and other human tumor xenografts. Consistent images of RCC xenografts (greater than 60 mg) were obtained without background subtraction. The amount of radiolabeled A6H in the tumor usually ranged from five to twenty times that of the blood. Normal mouse tissues, abscesses, and other human tumor xenografts contained less radiolabel per mg than did blood. A control monoclonal antibody of the same isotype failed to exhibit any localization in xenografts or normal tissues. Approximately 40% of the radiolabeled A6H dose per g was localized in the RCC xenograft 2 days after injection, although at the time of imaging about 60% of the radiolabel remaining in the mouse was associated with the xenograft. These results demonstrate that a RCC restrictive monoclonal antibody does specifically localize to RCC xenografts and supports the hope that this approach may have clinical value for diagnosis, staging, or treatment.
- Published
- 1985
32. Monoclonal antibodies to human renal cell carcinoma: recognition of shared and restricted tissue antigens.
- Author
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Vessella RL, Moon TD, Chiou RK, Nowak JA, Arfman EW, Palme DF, Peterson GA, and Lange PH
- Subjects
- Animals, Antibody Specificity, Binding, Competitive, Carbohydrates immunology, Cell Line, Cytotoxicity, Immunologic, Fluorescent Antibody Technique, Humans, Kidney immunology, Mice, Mice, Nude, Neoplasm Proteins immunology, Neoplasm Transplantation, Antibodies, Monoclonal immunology, Antibodies, Neoplasm immunology, Carcinoma, Renal Cell immunology, Kidney Neoplasms immunology
- Abstract
Monoclonal antibodies (MABs) reactive with human renal cell carcinoma (RCC) were generated following immunization of mice with either RCC homogenates, RCC cell lines, or fetal kidney homogenates. The characteristics of four highly reactive immunoglobulin G1 MABs, designated UMVA-RCC-A6H, UMVA-RCC-A36, UMVA-RCC-C5H and UMVA-RCC-D5D are presented. The screening process consisted of a cell binding enzyme-linked immunosorbent assay and immunohistological examination of tumor, normal, and fetal tissue sections. The MABs illustrated various degrees of antigen restriction: A6H identified an antigen common to RCC, some lung and colon carcinomas, the proximal renal tubules but no other normal tissues; A36 reacted with most human tumors, the renal tubules, and many other normal tissues; C5H reacted with nearly every human cancer but of the normal tissues, only the renal glomerulus shared this antigen; D5D was very restrictive, reacting with many although not all RCC and no other cancers or normal tissues with the exception of an occasional reactivity with a Bowman's capsule. Metastatic RCC and RCC xenografts expressed these antigens. None of the MABs participated in complement-mediated cytotoxicity. In immunoprecipitation studies with L-[methyl-3H]methionine and [3H]glucosamine-HCl metabolically labeled RCC cells, C5H was shown to be associated with an antigen of Mr 115,000.
- Published
- 1985
33. Hygroscopic Characteristics of Peanut Components and Their Influence on Growth and Aflatoxin Production by Aspergillus parasiticus.
- Author
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Chiou RY, Koehler PE, and Beuchat LR
- Abstract
Sound inshell runner-type peanuts, manually damaged inshell peanuts, shells, sound kernels, deskinned kernels and skins were stored in separate flasks under an atmospheric relative humidity of 100% at 28°C. After 5 d, water was adsorbed at levels of 1.2, 1.7, 3.9, 0.9, 1.0 and 9.5 g/100 g dry material, respectively. Surface disinfected components were inoculated with conidiospores of Aspergillus parasiticus NRRL 2999 and incubated under the same conditions. The time required for visible growth of the fungus was 8, 6, 4, 12, 10 and 3 d, respectively. The time for appearance of the conidiospores was 14, 10, 6, 16, 13 and 6 d. After a 3-wk incubation period, aflatoxin levels in peanut components were 111.4, 159.1, 4.4, 58.7, 99.0 and 1.5 μg/g, respectively.
- Published
- 1984
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