417 research outputs found

    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

    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

    Vegetation in the superior vena cava: a complication of tunneled dialysis catheters

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    Long-Term Prediction of Emergency Department Revenue and Visitor Volume Using Autoregressive Integrated Moving Average Model

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    This study analyzed meteorological, clinical and economic factors in terms of their effects on monthly ED revenue and visitor volume. Monthly data from January 1, 2005 to September 30, 2009 were analyzed. Spearman correlation and cross-correlation analyses were performed to identify the correlation between each independent variable, ED revenue, and visitor volume. Autoregressive integrated moving average (ARIMA) model was used to quantify the relationship between each independent variable, ED revenue, and visitor volume. The accuracies were evaluated by comparing model forecasts to actual values with mean absolute percentage of error. Sensitivity of prediction errors to model training time was also evaluated. The ARIMA models indicated that mean maximum temperature, relative humidity, rainfall, non-trauma, and trauma visits may correlate positively with ED revenue, but mean minimum temperature may correlate negatively with ED revenue. Moreover, mean minimum temperature and stock market index fluctuation may correlate positively with trauma visitor volume. Mean maximum temperature, relative humidity and stock market index fluctuation may correlate positively with non-trauma visitor volume. Mean maximum temperature and relative humidity may correlate positively with pediatric visitor volume, but mean minimum temperature may correlate negatively with pediatric visitor volume. The model also performed well in forecasting revenue and visitor volume

    Oromotor variability in children with mild spastic cerebral palsy: a kinematic study of speech motor control

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    <p>Abstract</p> <p>Background</p> <p>Treating motor speech dysfunction in children with CP requires an understanding of the mechanism underlying speech motor control. However, there is a lack of literature in quantitative measures of motor control, which may potentially characterize the nature of the speech impairments in these children. This study investigated speech motor control in children with cerebral palsy (CP) using kinematic analysis.</p> <p>Methods</p> <p>We collected 10 children with mild spastic CP, aged 4.8 to 7.5 years, and 10 age-matched children with typical development (TD) from rehabilitation department at a tertiary hospital. All children underwent analysis of percentage of consonants correct (PCC) and kinematic analysis of speech tasks: poly-syllable (PS) and mono-syllable (MS) tasks using the Vicon Motion 370 system integrated with a digital camcorder. Kinematic parameters included spatiotemporal indexes (STIs), and average values and coefficients of variation (CVs) of utterance duration, peak oral opening displacement and velocity. An ANOVA was conducted to determine whether PCC and kinematic data significantly differed between groups.</p> <p>Results</p> <p>CP group had relatively lower PCCs (80.0-99.0%) than TD group (<it>p </it>= 0.039). CP group had higher STIs in PS speech tasks, but not in MS tasks, than TD group did (<it>p </it>= 0.001). The CVs of utterance duration for MS and PS tasks of children with CP were at least three times as large as those of TD children (<it>p </it>< 0.01). However, average values of utterance duration, peak oral opening displacement and velocity and CVs of other kinematic data for both tasks did not significantly differ between two groups.</p> <p>Conclusion</p> <p>High STI values and high variability on utterance durations in children with CP reflect deficits in relative spatial and/or especially temporal control for speech in the CP participants compared to the TD participants. Children with mild spastic CP may have more difficulty in processing increased articulatory demands and resulted in greater oromotor variability than normal children. The kinematic data such as STIs can be used as indices for detection of speech motor control impairments in children with mild CP and assessment of the effectiveness in the treatment.</p

    Effects of Lower Limb Cycling Training on Different Components of Force and Fatigue in Individuals With Parkinson’s Disease

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    The strength of lower extremity is important for individuals to maintain balance and ambulation functions. The previous studies showed that individuals with Parkinson’s disease suffered from fatigue and strength loss of central origin. The purpose of this study was to investigate the effect of lower extremities’ cycling training on different components of force and fatigue in individuals with Parkinson’s disease. Twenty-four individuals (13 males, 11 females, mean age: 60.58 ± 8.21 years) diagnosed with idiopathic Parkinson’s disease were randomized into training and control groups. The maximum voluntary contraction (MVC) force, voluntary activation level (VA), and twitch force of knee extensors were measured using a custom-made system with surface electrical stimulation. The general, central, and peripheral fatigue indexes (GFI, CFI, and PFI) were calculated after a fatiguing cycling protocol. Subjects received 8 weeks of low resistance cycling training (training group) or self-stretching (control group) programs. Results showed that MVC, VA, and twitch force improved (p \u3c 0.05) only in the training group. Compared to the baseline, central fatigue significantly improved in the training group, whereas peripheral fatigue showed no significant difference in two groups. The cycling training was beneficial for individuals with Parkinson’s disease not only in muscle strengthening but also in central fatigue alleviation. Further in-depth investigation is required to confirm the effect of training and its mechanism on central fatigue

    Gram Level scFv expression platform of Pichia pastoris

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    The methylotrophic yeast Pichia pastoris secretion expression system has been developed for the antibody fragments (scFv) production platform. The platform includes three technology platforms, the first one is strain generation, the second is fermentation process development in 250 ml fermentor and the last is process scale up to 5 L. A recombinant scFv went through clone generation, include signal peptide tool box, normally yield 2.5 mg/L titer in deep well. Through the fermentation process development of induction medium composition and feeding strategy by Eppendorf Dasgip parallel 250 ml mini fermentor. During induction step, feeding 100% methanol as induction medium can only produce less than 50 mg/L scFv while feeding methanol-sorbitol mixture can significant increase the production yield to 306 mg/L in five days, about 6-folds increase in productivity. With the supply of additional nitrogen source during glycerol feeding step or at induction step, higher scFv production with 510 mg/L can be achieved. Thus, following the medium composition optimization, the production titer was improved 10 folds in 250 ml mini-fermentor stage. Moreover, when we switched the induction medium feeding strategy from DO-stat to the stepwise feeding, the titer increased form 510 mg/L to ~1000 mg/L and yielded another 2- folds improvement. During medium composition and feeding strategy optimization at 250 ml mini fermentor scale, the production titer could increase 20 folds. Overall, the production titer increased 400 folds from cell line generation to 250 ml fermentation parameter optimization. Furthermore, the process parameter can be scale-up to 5 L fernentor achieving \u3e 1 g/L. Recent progress to include BIP in the expression vector gave at least 2 fold improvement in scFv titer in shake flask, the new clone will be optimized in our established 250 ml and 5 L fermentation platform. Please click Additional Files below to see the full abstract

    Gram level scFv expression platform of Phichi pastoris

    Get PDF
    The methylotrophic yeast Pichia pastoris secretion expression system has been developed for the antibody fragments (scFv) production platform. The platform includes three technology platforms, the first one is strain generation, the second is fermentation process development in 250 ml fermentor and the last is process scale up to 5 L. A recombinant scFv went through clone generation, include signal peptide tool box, normally yield 2.5 mg/L titer in deep well. Through the fermentation process development of induction medium composition and feeding strategy by Eppendorf Dasgip parallel 250 ml mini fermentor. During induction step, feeding 100% methanol as induction medium can only produce less than 50 mg/L scFv while feeding methanol-sorbitol mixture can significant increase the production yield to 306 mg/L in five days, about 6-folds increase in productivity. With the supply of additional nitrogen source during glycerol feeding step or at induction step, higher scFv production with 510 mg/L can be achieved. Thus, following the medium composition optimization, the production titer was improved 10 folds in 250 ml mini-fermentor stage. Moreover, when we switched the induction medium feeding strategy from DO-stat to the stepwise feeding, the titer increased form 510 mg/L to ~1000 mg/L and yielded another 2- folds improvement. During medium composition and feeding strategy optimization at 250 ml mini fermentor scale, the production titer could increase 20 folds. Overall, the production titer increased 400 folds from cell line generation to 250 ml fermentation parameter optimization. Furthermore, the process parameter can be scale-up to 5 L fernentor achieving \u3e 1 g/L. Recent progress to include BIP in the expression vector gave at least 2 fold improvement in scFv titer in shake flask, the new clone will be optimized in our established 250 ml and 5 L fermentation platform Please click Additional Files below to see the full abstract
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