Effect of isoflavones on the vascular actions of phosphodiesterase inhibitors

This journal suppl. entitled: EDHF 2012 - 10th Anniversary MeetingIsoflavones are present in high concentrations in soy products, the intake of which is associated with lower incidence of cardiovascular diseases. They can enhance contraction and inhibit relaxation through cyclic adenosine monophosphate (cAMP)-dependent pathway. The present study aimed to examine whether or not the major soy isoflav...postprin

Factors contributing to officers’ fatigue in high-speed maritime craft operations

Author name used in this publication: Jimmy J. M. Ng2005-2006 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

Age-related differences in neural activities during risk taking as revealed by functional MRI

Previous research has clearly documented that risky decision making is different in young and older adults. Yet, there has been a relative dearth of research that seeks to understand such age-related changes in the neural activities associated with risk taking. To address this research issue, 21 men (12 young men, mean age 29.9±6.2 years and 9 older men, mean age 65.2±4.2 years) performed a risky-gains task while their brain activities were monitored by an fMRI scanner. The older adults, relative to their younger peers, presented with contralateral prefrontal activity, particularly at the orbitofrontal cortex. Furthermore, stronger activation of the right insula was observed for the older-aged participants compared to the younger-aged adults. The findings of this study are consistent with the a priori speculations established in accordance with the HAROLD model as well as previous findings. Findings of this study suggest that when making risky decisions, there may be possible neuropsychological mechanisms underlying the change in impulsive and risk-taking behaviors during the course of natural ageing. © 2007 The Author(s).published_or_final_versio

Second order statistics based blind source separation for artifact correction of short ERP epochs

ERP is commonly obtained by averaging over segmented EEC epochs. In case artifacts are present in the raw EEC measurement, pre-processing is required to prevent the averaged ERP waveform being interfered by artifacts. The simplest pre-processing approach is by rejecting trials in which presence of artifact is detected. Alternatively artifact correction instead of rejection can be performed by blind source separation, so that waste of ERP trials is avoided. In this paper, we propose a second order statistics based blind source separation approach to ERP artifact correction. Comparing with blind separation using independent component analysis, second order statistics based method does not rely on higher order statistics or signal entropy, and therefore leads to more robust separation even if only short epochs are available.published_or_final_versio

Regulation of human behaviors

The development of the frontal systems is a major evolutionary advancement of the human race. It enables the regulation of behaviors in accordance with goals and, hence, frees humans from the constraints imposed by our basic physiological instincts. The burgeoning neuroscience and neuropsychology literature has consistently highlighted the important roles played by the prefrontal cortex and the anterior cingulate cortex in effective and efficient regulation of behaviors. On the other hand, aging is associated with changes in the neural network subserving behavioral regulation. Different neuropathologies also impact upon the function of the prefrontal cortex-anterior cingulate cortex system. Therefore, our brains require neural mechanisms in place that can facilitate functional recovery after brain injuries. Future research to enhance theoretical understanding of the neural mechanisms underlying the regulation of behaviors would contribute to the development of cost-effective treatment modalities that promote maximum functional return in people recovering from brain dysfunctions. © 2007 Future Medicine Ltd.link_to_subscribed_fulltex

How do figure-like orthographs modulate visual processing of Chinese words?

The effects of figure-like orthographs on visual processing of Chinese characters were examined using functional imaging in two inspection tasks: counting the number of strokes and categorizing a character as either a word or a nonword. Pictographic orthographs (characters resembling figures) were easier and faster to be inspected than their nonpictographic counterparts (characters not resembling figures) at the stroke but not the character level. The less intense activations found in the frontal and parietal regions suggest that such facilitation could be attributable to the visuospatial symmetry and regularity of the strokes borne by pictographic orthographs. Our findings further support that learning Chinese characters could begin with pictographic orthographs. © 2007 Lippincott Williams & Wilkins, Inc.link_to_subscribed_fulltex

Transcriptome profiling of Desmos chinensis: revealing the molecular basis of dipartite perianth evolution in the early-divergent angiosperm family Annonaceae

T4-28: Floral organ development: T4-28-02During the past 200 million years of speciation and hybridization, angiosperm genome structure has evolved and diversified in size and composition. While many angiosperm taxa experienced genome duplication and different degrees of transposable element proliferation, the homeotic control of floral development has remained conservative. The MIKC-type MADS-domain proteins are transcription factors that dictate organ identity during floral organogenesis. The classic “ABCDE” MADS-box gene expression model proposed for the core eudicots is not fully applicable to early-divergent angiosperms, in which a gradual transition is apparent between sepal-like outer tepals and petal-like inner tepals, leading to the proposed “fading-borders” expression model. Flowers in the Annonaceae deviate from other early-divergent angiosperms in possessing a distinctive dipartite perianth. Petals in the Annonaceae (‘bracteopetals’) have furthermore presumably evolved independently from andropetals in core eudicots. The degree of differentiation of petals from sepals in Annonaceae flowers is generally of functional significance (e.g., enabling the evolution of largely or fully enclosed pollination chambers during anthesis). Little is known of the genome and genetic control of floral development in the Annonaceae. The application of massive parallel sequencing techniques such as RNAseq provides opportunities to profile the transcriptomes of non-model organisms. In addition to a developmental study, we characterized the floral and leaf transcriptome of Desmos chinensis, a representative of the Annonaceae that possesses a dipartite perianth and which shares the basic floral Bauplan of the family, in order to understand the genetics of its floral development. Transcriptomes of developing and mature Desmos chinensis floral organs and leaves were sequenced using the high-throughput Illumina sequencing platform. After filtering, 16,098 genes and 22,112 transcripts were recovered from de novo assembly. We identified possible coding regions and compared them against five public databases. Based on sequence homology against the NCBI non-redundant protein database, transcripts were annotated with 3,991 unique gene ontology (GO) terms and categorized into functional groups. Functional group enrichment analysis was used to identify groups with significant expression level changes during organ development. Transcripts that are commonly differentially expressed among developing and mature floral organs and leaves were identified using the digital gene expression data. We identified 41 putative homeotic MADS-box gene homologs and their respective expression levels in order to determine whether Annonaceae flowers are consistent with the MADS-box gene “fading borders” expression model. Other floral developmental regulators of Desmos chinensis were also discovered. While many questions remain unresolved at the transcription level, our data emphasises the importance and potential of extending further studies into systems biology, and help understand floral developmental biology as biological networks

Functional gain in hemorrhagic stroke patients is predicted by functional level and cognitive abilities measured at hospital admission

Background and purpose: Few studies have addressed factors that contribute to functional recovery in people with hemorrhagic stroke. We assessed the value of using pre-training functional level and cognitive abilities measured at admission in order to predict functional gain in a sample of stroke patients. Methods: The Functional Independence Measure (FIM) was administered to 85 hemorrhagic stroke patients. Three multiple regression models were constructed using total gain in FIM scores, gain in scores in the cognitive domain of FIM, and gain in scores in the motor domain of FIM as outcome variables. Predictor variables were age; scores on the Digit Span Forward Test (DSF), Digit Span Backward Test (DSB), and Chinese Auditory Verbal Learning Test (CAVLT); and the FIM scores measured at admission. Results: All regression models were significant, Ps < 0.001, and each explained over 73% of the variance in the FIM gains. Age and admission FIM scores were both significant predictors in each of the three models. The DSB span score was a significant predictor of the total FIM and the cognitive FIM gains. The CAVLT recognition score was also a significant predictor of the cognitive FIM gain. Conclusions: Functional improvement in patients with hemorrhagic stroke after in-patient rehabilitation was predicted by age, pre-training functional level, and cognitive abilities measured at admission. © 2010 - IOS Press and the authors. All rights reserved.link_to_subscribed_fulltex

Sex-related differences in neural activity during risk taking: An fMRI study

This study explored sex effects on the process of risk-taking. We observed that the female participants (n = 10) showed stronger activation in the right insula and bilateral orbitofrontal cortex (OFC) than did the male participants (n = 12) while they were performing in the Risky-Gains task. The female participants also showed stronger activations in the precentral, postcentral, and paracentral regions after receiving punishment feedback. In addition, the strength of neural activity in the insula correlated with the rate of risky behaviors for the female participants but not for the male participants. Similarly, the percent signal changes in the right OFC correlated negatively with the rate of selecting risky choices for the female group. These findings strongly suggest a sex-related influence modulating brain activity during risk-taking tasks. When taking the same level of risk, relative to men, women tend to engage in more neural processing involving the insula and the OFC to update and valuate possible uncertainty associated with risk-taking decision making. These results are consistent with the value-based decision-making model and offer insights into the possible neural mechanisms underlying the different risk-taking attitudes of men and women.link_to_OA_fulltex

A possible role of p73 on the modulation of p53 level through MDM2

MDM2, one of the transcriptional targets of p53, can target p53 for degradation in a negative feedback loop. The p53-related protein p73, however, can bind to MDM2 but is not consequently down-regulated. Here we demonstrate that p73 could transactivate the MDM2 promoter in p53-null cell lines. In p53-null cell lines, the level of MDM2 was increased by p73 due to increases in transcription and protein stability of MDM2. In transient transfection assays, inhibition of the transcriptional activity of p73 required a higher amount of MDM2 than that of p53. This is probably due to the fact that MDM2 can target p53, but not p73, for degradation. We demonstrated further that the level of p53 could be altered by a cooperation between MDM2 and p73, but not by transcriptional inactive mutants of p73. Expression of p73 resulted in a reduction of the ectopically expressed p53 in transient transfections or of the endogenous p53 induced by Adriamycin- or UV-mediated damage. These reductions of p53 were likely to be due to an increase in MDM2-mediated proteolysis. These results suggest the possibility that different levels of p73 in the cell may act as a mechanism to modulate p53 responses after DNA damage and other stresses and that an increase rather than a decrease in p73 may play a role in tumorigenesis.link_to_subscribed_fulltex