1,684 research outputs found

    The diverse magneto-optical selection rules in bilayer black phosphorus

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    The magneto-optical properties of bilayer phosphorene is investigated by the generalized tight-binding model and the gradient approximation. The vertical inter-Landau-level transitions, being sensitive to the polarization directions, are mainly determined by the spatial symmetries of sub-envelope functions on the distinct sublattices. The anisotropic excitations strongly depend on the electric and magnetic fields. A perpendicular uniform electric field could greatly diversify the selection rule, frequency, intensity, number and form of symmetric absorption peaks. Specifically, the unusual magneto-optical properties appear beyond the critical field as a result of two subgroups of Landau levels with the main and side modes. The rich and unique magneto-absorption spectra arise from the very close relations among the geometric structures, multiple intralayer and interlayer hopping integrals, and composite external fields

    Positive outcome expectancy mediates the relationship between social influence and Internet addiction among senior high-school students

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    Background and aims Based on the foundations of Bandura’s social cognitive theory and theory of triadic influence (TTI) theoretical framework, this study was designed to examine the mediating role of positive outcome expectancy of Internet use in the relationship between social influence and Internet addiction (IA) in a large representative sample of senior high-school students in Taiwan. Methods Using a cross-sectional design, 1,922 participants were recruited from senior high schools throughout Taiwan using both stratified and cluster sampling, and a comprehensive survey was administered. Results Structural equation modeling and bootstrap analyses results showed that IA severity was significantly and positively predicted by social influence, and fully mediated through positive outcome expectancy of Internet use. Discussion and conclusions The results not only support Bandura’s social cognitive theory and TTI framework, but can also serve as a reference to help educational agencies and mental health organizations design programs and create policies that will help in the prevention of IA among adolescents

    Genome architecture changes and major gene variations of Andrias davidianus ranavirus (ADRV)

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    Ranaviruses are emerging pathogens that have led to global impact and public concern. As a rarely endangered species and the largest amphibian in the world, the Chinese giant salamander, Andrias davidianus, has recently undergone outbreaks of epidemic diseases with high mortality. In this study, we isolated and identified a novel ranavirus from the Chinese giant salamanders that exhibited systemic hemorrhage and swelling syndrome with high death rate in China during May 2011 to August 2012. The isolate, designated Andrias davidianus ranavirus (ADRV), not only could induce cytopathic effects in different fish cell lines and yield high viral titers, but also caused severely hemorrhagic lesions and resulted in 100% mortality in experimental infections of salamanders. The complete genome of ADRV was sequenced and compared with other sequenced amphibian ranaviruses. Gene content and phylogenetic analyses revealed that ADRV should belong to an amphibian subgroup in genus Ranavirus, and is more closely related to frog ranaviruses than to other salamander ranaviruses. Homologous gene comparisons show that ADRV contains 99%, 97%, 94%, 93% and 85% homologues in RGV, FV3, CMTV, TFV and ATV genomes respectively. In addition, several variable major genes, such as duplicate US22 family-like genes, viral eukaryotic translation initiation factor 2 alpha gene and novel 75L gene with both motifs of nuclear localization signal (NLS) and nuclear export signal (NES), were predicted to contribute to pathogen virulence and host susceptibility. These findings confirm the etiologic role of ADRV in epidemic diseases of Chinese giant salamanders, and broaden our understanding of evolutionary emergence of ranaviruses

    Effects of orthographic consistency and homophone density on Chinese spoken word recognition

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    Studies of alphabetic language have shown that orthographic knowledge influences phonological processing during spoken word recognition. This study utilized the Event-Related Potentials (ERPs) to differentiate two types of phonology-to-orthography (P-to-O) mapping consistencies in Chinese, namely homophone density and orthographic consistency. The ERP data revealed an orthographic consistency effect in the frontal-centrally distributed N400, and a homophone density effect in central-posteriorly distributed late positive component (LPC). Further source analyses using the standardized low-resolution electromagnetic tomography (sLORETA) demonstrated that the orthographic effect was not only localized in the frontal and temporal-parietal regions for phonological processing, but also in the posterior visual cortex for orthographic processing, while the homophone density effect was found in middle temporal gyrus for lexical-semantic selection, and in the temporal-occipital junction for orthographic processing. These results suggest that orthographic information not only shapes the nature of phonological representations, but may also be activated during on-line spoken word recognition

    The feedback consistency effect in Chinese character recognition:evidence from a psycholinguistic norm

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    Researchers have demonstrated the importance of phonology in literacy acquisition and in visual word recognition. For example, the spelling-to-sound consistency effect has been observed in visual word recognition tasks, in which the naming responses are faster and more accurate for words with the same letters that also have the same pronunciation (e.g. -ean is always pronounced /in/, as in lean, dean, and bean). In addition, some studies have reported a much less intuitive feedback consistency effect when a rime can be spelled in different ways (e.g. /ip/ in heap and deep) in lexical decision tasks. Such findings suggest that, with activation flowing back and forth between orthographic and phonological units during word processing, any inconsistency in the mappings between orthography and phonology should weaken the stability of the feedback loop, and, thus, should delay recognition. However, several studies have failed to show reliable feedback consistency in printed word recognition. One possible reason for this is that the feedback consistency is naturally confounded with many other variables, such as orthographic neighborhood or bigram frequency, as these variables are difficult to tease apart. Furthermore, there are challenges in designing factorial experiments that perfectly balance lexical stimuli on all factors besides feedback consistency. This study aims to examine the feedback consistency effect in reading Chinese characters by using a normative data of 3,423 Chinese phonograms. We collected the lexical decision time from 180 college students. A linear mixed model analysis was used to examine the feedback consistency effect by taking into account additional properties that may be confounded with feedback consistency, including character frequency, number of strokes, phonetic combinability, semantic combinability, semantic ambiguity, phonetic consistency, noun-to-verb ratios, and morphological boundedness. Some typical effects were observed, such as the more frequent and familiar a character, the faster one can decide it is a real character. More importantly, the linear mixed model analysis revealed a significant feedback consistency effect while controlling for other factors, which indicated that the pronunciation of phonograms might accommodate the organization of Chinese orthographic representation. Our study disentangled the feedback consistency from the many other factors, and supports the view that phonological activation would reverberate to orthographic representation in visual word recognition

    OncoDB.HCC: an integrated oncogenomic database of hepatocellular carcinoma revealed aberrant cancer target genes and loci

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    The OncoDB.HCC () is based on physical maps of rodent and human genomes containing quantitative trait loci of rodent HCC models and various human HCC somatic aberrations including chromosomal data from loss of heterozygosity and comparative genome hybridization analyses, altered expression of genes from microarray and proteomic studies, and finally experimental data of published HCC genes. Comprehensive integration of HCC genomic aberration data avoids potential pitfalls of data inconsistency from single genomic approach and provides lines of evidence to reveal somatic aberrations from levels of DNA, RNA to protein. Twenty-nine of 30 (96.7%) novel HCC genes with significant altered expressions in compared between tumor and adjacent normal tissues were validated by RT–PCR in 45 pairs of HCC tissues and by matching expression profiles in 57 HCC patients of re-analyzed Stanford HCC microarray data. Comparative mapping of HCC loci in between human aberrant chromosomal regions and QTLs of rodent HCC models revealed 12 syntenic HCC regions with 2 loci effectively narrowed down to 2 Mb. Together, OncoDB.HCC graphically presents comprehensive HCC data integration, reveals important HCC genes and loci for positional cloning and functional studies, and discloses potential molecular targets for improving HCC diagnosis and therapy
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