528 research outputs found

    Stability analysis for dynamical neural network systems

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    In this paper, the small gain theorem will be used to establish a criterion for the stability of a feedback system containing a feedforward neural network. A method for the determination of the gain of a piecewise-linear feedforward neural network is introduced and applied to the stability analysis for a control system consisting of a LTI SISO system with a dynamic ANN controller.published_or_final_versio

    On the design and implementation of a high definition multi-view intelligent video surveillance system

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    This paper proposes a distributed architecture for high definition (HD) multi-view video surveillance system. It adopts a modular design where multiple intelligent Internet Protocol (IP)-based video surveillance cameras are connected to a local video server. Each server is equipped with storage and optional graphics processing units (GPUs) for supporting high-level video analytics and processing algorithms such as real-time decoding and tracking for the video captured. The servers are connected to the IP network for supporting distributed processing and remote data access. The DSP-based surveillance camera is equipped with realtime algorithms for streaming compressed videos to the server and performing simple video analytics functions. We also developed video analytics algorithms for security monitoring. Both publicly available data set and real video data that are captured under indoor and outdoor scenarios are used to validate our algorithms. Experimental results show that our distributed system can support real-time video applications with high definition resolution.published_or_final_versio

    On the Hardware/Software Design and Implementation of a High Definition Multiview Video Surveillance System

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    Source origins, modeled profiles, and apportionments of halogenated hydrocarbons in the greater Pearl River Delta region, southern China

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    We analyze 16-month data of 13 major halocarbons measured at a southern China coastal site in the greater Pearl River Delta (PRD). A total of 188 canister air samples were collected from August 2001 to December 2002. Overall inspection indicated that CH2Cl2, C2Cl 4, and C2HCl3 had similar temporal variations while CFC-11, CFC-12, and CFC-113 showed the same emission patterns during the sampling period. Diurnal variations of halocarbons presented different patterns during ozone episode days, mainly related to emission strength, atmospheric dispersion, and photochemical lifetimes. For further statistics and source appointment, Lagrangian backward particle release simulations were conducted to help understand the potential source regions of all samples and classify them into different categories, including local Hong Kong, inner PRD, continental China, and marine air masses. With the exception of HCFC-142b, the mixing ratios of all halocarbons in marine air were significantly lower than those in urban and regional air (p < 0.01), whereas no significant difference was found between urban Hong Kong and inner PRD regional air, reflecting the dominant impact of the greater PRD regional air on the halocarbon levels. The halocarbon levels in this region were significantly influenced by anthropogenic sources, causing the halocarbon mixing ratios in South China Sea air to be higher than the corresponding background levels, as measured by global surface networks and by airborne missions such as Transport and Chemical Evolution Over the Pacific. Interspecies correlation analysis suggests that CHCl3 is mainly used as a solvent in Hong Kong but mostly as a feedstock for HCFC-22 in the inner PRD. Furthermore, CH3Cl is often used as a refrigerant and emitted from biomass/biofuel burning in the inner PRD. A positive matrix factorization receptor model was applied to the classified halocarbon samples in the greater PRD for source profiles and apportionments. Seven major sources were identified and quantified. Emissions from solvent use were the most significant source of halocarbons (71 ± 9%), while refrigeration was the second largest contributor (18 ± 2%). By further looking at samples from the inner PRD and from urban Hong Kong separately, we found that more solvent was used in the dry cleaning industry in Hong Kong, whereas the contribution of cleaning solvent in the electronic industry was higher in the inner PRD. Besides the two common sources of solvent use and refrigeration, the contributions of biomass/biofuel burning and feedstock in chemical manufacturing was remarkable in the inner PRD but negligible in Hong Kong. These findings are of help to effectively control and phase out the emissions of halocarbons in the greater PRD region of southern China Copyright 2009 by the American Geophysical Union

    Endoplasmic reticulum stress induces tau pathology and forms a vicious cycle: Implication in Alzheimer's disease pathogenesis

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    Accumulation of unfolded proteins can disturb the functions of the endoplasmic reticulum (ER), leading to ER-stress or unfolded protein response (UPR). Recent data have shown that activation of UPR can be found in postmortem brains of Alzheimer's disease (AD) patients; and biological markers for activation of UPR are abundant in neurons with diffuse phosphorylated tau. Although these observations suggest a linkage between ER-stress and tau pathology, little is known of their relationship. In this study, we found that high levels of phosphorylated PKR-like ER-resident kinase (p-PERK) and phosphorylated eukaryotic initiation factor 2 alpha (p-eIF2α) as markers for activation of UPR in the hippocampus of aged P301L mutant tau transgenic mice. The immunoreactivity of p-PERK was found to co-localize with that of phosphorylated tau. We then hypothesized that phosphorylation of tau could induce ER-stress and vice versa in promoting AD-like pathogenesis. By using the protein phosphatase 2A inhibitor okadaic acid (OA) as an inducer for phosphorylation of tau, we found that primary cultures of rat cortical neurons treated with OA triggered UPR as indicated by increased levels of p-PERK and p-eIF2α, splicing of mRNA for xbp-1 and elevated levels of mRNA for GADD153. On the other hand, thapsigargin as an ER-stress inducer stimulated phosphorylation of tau at Thr231, Ser262 and Ser396. Thapsigargin also induced activation of caspase-3 and cleavage of tau. These findings suggested that ER-stress and hyperphosphorylation of tau could be induced by each other to form a vicious cycle to propagate AD-like neurodegeneration. © 2012 - IOS Press and the authors. All rights reserved.postprin

    Sympatric Spawning but Allopatric Distribution of Anguilla japonica and Anguilla marmorata: Temperature- and Oceanic Current-Dependent Sieving

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    Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24°C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them “temperate” and “tropical” eels, respectively

    Source origins, modeled profiles, and apportionments of halogenated hydrocarbons in the greater Pearl River Delta region, southern China  

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    Author name used in this publication: H. GuoAuthor name used in this publication: T. WangAuthor name used in this publication: W. T. HungAuthor name used in this publication: Y. S. Li2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Age- Matched Comparison of Children Hospitalized for 2009 Pandemic H1N1 Influenza with Those Hospitalized for Seasonal H1N1 and H3N2

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    BACKGROUND: A wide spectrum of clinical manifestation ranging from deaths to a mild course of disease has been reported in children infected with the 2009 pandemic H1N1 (pH1N1) influenza. METHODOLOGY/MAJOR FINDINGS: We conducted an age-matched control study comparing children hospitalized for pH1N1 with historic controls infected with seasonal H1N1 and H3N2 influenza to correct for the effect of age on disease susceptibility and clinical manifestations. We also compared children with pH1N1 to children concurrently admitted for seasonal influenza during the pandemic period to adjust for differences in health-seeking behavior during the pandemic or other potential bias associated with historic controls. There was no death or intensive care admission. Children with pH1N1 were more likely to have at least one risk condition for influenza, an underlying chronic pulmonary condition, more likely to have asthma exacerbation and to be treated with oseltamivir. There was no difference in other aspects of the clinical course or outcome. CONCLUSION: Disease manifestation of children hospitalized for pH1N1 infection was mild in our patient population

    Traditional beliefs and practices in the postpartum period in Fujian Province, China: a qualitative study

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    <p>Abstract</p> <p>Background</p> <p><it>Zuo yuezi </it>is the month postpartum in China associated with a variety of traditional beliefs and practices. We explored the current status of <it>zuo yuezi </it>from social, cultural and western medical perspectives.</p> <p>Methods</p> <p>We interviewed family members (36) and health workers (8) in Fujian Province, selecting one rural and one rapidly developing urban county. We asked about their traditional beliefs and their behaviour postpartum. We used a framework approach to identify main themes. We categorised reported behaviour against their probable effects on health, drawing on Western standards.</p> <p>Results</p> <p>Respondents reported that <it>zuo yuezi </it>was commonly practiced in urban and rural families to help the mother regain her strength and protect her future health. <it>Zuo yuezi </it>included: dietary precautions, such as eating more food and avoiding cold food; behavioural precautions, such as staying inside the home, avoiding housework and limiting visitors; hygiene precautions, such as restricting bathing and dental hygiene; and practices associated with infant feeding, including supplementary feeding and giving honeysuckle herb to the infant. Respondents reported that the main reasons for adhering to these practices were respect for tradition, and following the advice of elders. Categorised against Western medical standards, several <it>zuo yuezi </it>practices are beneficial, including eating more, eating protein rich food, avoiding housework, and daily vulval and perineal hygiene. A few are potentially harmful, including giving honeysuckle herb, and avoiding dental hygiene. Some women reported giving infants supplementary feeds, although <it>zuo yuezi </it>emphasises breast feeding.</p> <p>Conclusion</p> <p><it>Zuo yuezi </it>is an important ritual in Fujian. In medical terms, most practices are beneficial, and could be used by health staff to promote health in this period. Further research on reported potentially harmful practices, such as supplements to breast feeding, is needed.</p
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