35 research outputs found

    Investigation of the Return and Volatility Clustering Effects in China Stock Markets

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    This dissertation examines the return and volatility in Shanghai Stock Exchange (SSE); Shenzhen Stock Exchange (SZSE); Hong Kong Stock Exchange (HKEx) and Taiwan Stock Exchange (TWSE) in China for the period Jan 2002-Dec 2008 employing the GARCH models. GARCH-M; TGARCH-M and EGARCH-M model are estimated using three return intervaldaily; weekly and monthly. The results confirmed the leverage effects in these stock markets; but the significance of the estimation are questioned partly for the insufficient data in low frequency intervals. Comparison between the three models concluded with the superiority of the EGARCH over the other two models. Misspecification testing and Granger Causality Test are employed for modification of the model and examination of the spillover effect in the markets. ARMA lag specification in mean equations are suggested for the modification of the models; inclusion of GARCH variance lag terms in the variance equation also recommended for the models of the markets that have spillover effect between or from other markets

    Soybean \u3ci\u3eGm\u3c/i\u3eSAUL1, a Bona Fide U-Box E3 Ligase, Negatively Regulates Immunity Likely through Repressing the Activation of \u3ci\u3eGm\u3c/i\u3eMPK3

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    E3 ubiquitin ligases play important roles in plant immunity, but their role in soybean has not been investigated previously. Here, we used Bean pod mottle virus (BPMV)-mediated virusinduced gene silencing (VIGS) to investigate the function of GmSAUL1 (Senescence-Associated E3 Ubiquitin Ligase 1) homologs in soybean. When two closely related SAUL1 homologs were silenced simultaneously, the soybean plants displayed autoimmune phenotypes, which were significantly alleviated by high temperature, suggesting that GmSAUL1a/1b might be guarded by an R protein. Interestingly, silencing GmSAUL1a/1b resulted in the decreased activation of GmMPK6, but increased activation of GmMPK3 in response to flg22, suggesting that the activation of GmMPK3 is most likely responsible for the activated immunity observed in the GmSAUL1a/1b-silenced plants. Furthermore, we provided evidence that GmSAUL1a is a bona fide E3 ligase. Collectively, our results indicated that GmSAUL1 plays a negative role in regulating cell death and immunity in soybean

    An Integrated Individual Environmental Exposure Assessment System for Real-Time Mobile Sensing in Environmental Health Studies

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    The effects of environmental exposure on human health have been widely explored by scholars in health geography for decades. However, recent advances in geospatial technologies, especially the development of mobile approaches to collecting real-time and high-resolution individual data, have enabled sophisticated methods for assessing people’s environmental exposure. This study proposes an individual environmental exposure assessment system (IEEAS) that integrates objective real-time monitoring devices and subjective sensing tools to provide a composite way for individual-based environmental exposure data collection. With field test data collected in Chicago and Beijing, we illustrate and discuss the advantages of the proposed IEEAS and the composite analysis that could be applied. Data collected with the proposed IEEAS yield relatively accurate measurements of individual exposure in a composite way, and offer new opportunities for developing more sophisticated ways to measure individual environmental exposure. With the capability to consider both the variations in environmental risks and human mobility in high spatial and temporal resolutions, the IEEAS also helps mitigate some uncertainties in environmental exposure assessment and thus enables a better understanding of the relationship between individual environmental exposure and health outcomes

    Infection status and risk factors of HIV, HBV, HCV, and syphilis among drug users in Guangdong, China - a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>China has witnessed a remarkable increase in sexually transmitted infections (STIs) and HIV. The study is to assess the prevalence of HIV, HBV, HCV and syphilis and related risk factors among drug users in mandatory detoxification center Qingyuan, Guangdong, China.</p> <p>Method</p> <p>A cross-sectional study on drug use behaviors, sex behaviors, and presence of antibodies to HIV, HCV, Treponema pallidum, and surface antigen of HBV (HBsAg) was conducted among drug users recruited from 3 detoxification centers in Qingyuan, Guangdong, China. Risk factors for each of four infections were analyzed with logistic regression model.</p> <p>Results</p> <p>A total of 740 subjects were recruited, the median age was 31 years old (range 24-38). The seroprevalence rates of HIV, HBsAg, HCV and syphilis were 4.6%, 19.3%, 71.6% and 12.6%, respectively. Risk factors for HIV were intravenous drug use and co-infection with syphilis. Having a regular sexual partner who was a drug user was considered to be a risk factor for HBV. Intravenous drug use was a risk factor for HCV. However, the consistent use of condoms with commercial sex partners was protective for HCV infection. Compared to drug users living in urban area, those living in rural areas were more likely to be infected with syphilis, and there was an association between commercial sex and syphilis.</p> <p>Conclusion</p> <p>The prevalence of HIV, HBV, HCV and syphilis were high among drug users in detoxification centers in Qingyuan, thus, risk reduction programs for the drug user population is urgently required.</p

    An Impact Asymmetry Analysis of Small Urban Green Space Attributes to Enhance Visitor Satisfaction

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    Urban green spaces have beneficial effects on the health and well-being of citizens. Understanding the factors influencing visitor satisfaction with urban green spaces contributes to making more informed policies. Prior studies on green spaces satisfaction primarily focused on the linear correlation between small urban green space attributes and satisfaction. In this manuscript, we presented a study aimed to (1) identify the attributes of SUGS as frustrators, dissatisfiers, hybrids, satisfiers, and delighters; (2) prioritize attributes for effective satisfaction management; (3) assist managers in drafting guidelines for operational management decisions. We gathered a range of information about the users to nine SUGS in Shanghai, in 2020, via a questionnaire, and we found that safety, noise, and social interaction are improvement priorities. Squares and visitors&rsquo; behavior should not be ignored in SUGS management. Moreover, managers should carefully monitor SUGS attributes of the social environment to meet users&rsquo; expectations. The findings of this study have implications for SUGS management and future research

    Functions of the C2H2 Transcription Factor Gene thmea1 in Trichoderma harzianum under Copper Stress Based on Transcriptome Analysis

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    Trichoderma spp. are important biocontrol filamentous fungi and have tremendous potential in soil bioremediation. In our previous studies, a C2H2 type transcription factor coding gene (thmea1) was cloned from a biocontrol agent T. harzianum Th-33; the encoded sequence of thmea1 contained 3 conserved C2H2 domains with Swi5 and Ace2 in Saccharomyces cerevisiae. The thmea1 knockout mutant Δthmea1 showed 12.9% higher copper tolerance than the wild-type Th33. To elucidate the function of thmea1 and its relationship with copper stress response, we conducted transcriptome sequencing and analysis of wild-type Th33 and Δthmea1 under 0.8 mM copper stress. A total of 1061 differentially expressed genes (DEGs) were identified between the two strains, all DEGs were assigned to KEGG pathway database, 383 DEGs were annotated in 191 individual pathways, and the categories of ribosomal protein synthesis and amino acid metabolism were the most highly enriched ones. Analysis of related DEGs showed that the expression levels of intracellular glutathione detoxification enzyme, heat shock proteins, and ribosomal proteins in Δthmea1 were higher than that of the wild-type Th33, and the expression of metallothionein (MT) gene did not change. In addition, the expression levels of genes coding for proteins associated with the Ccc2p-mediated copper chaperone Atx1p transport of copper ions into the Golgi secretory pathway increased, as well as the copper amine oxidase (CuAO). These findings suggest that Thmea1 is a negative regulated factor of copper tolerance ability in T. harzianum. It does not show metallothionein expression activator activities as that of Ace2 in S. cerevisiae. We hypothesize that after T. harzianum has lost its thmea1 gene, the ability of cells to scavenge reactive oxygen species, mainly through the glutathione antioxidant system, is enhanced, whereas protein synthesis and repair and copper secretion increase under copper stress, which increases the ability of the mutant strain to tolerate copper stress

    Low-Complexity Robust Adaptive Beamforming Based on INCM Reconstruction via Subspace Projection

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    Adaptive beamforming is sensitive to steering vector (SV) and covariance matrix mismatches, especially when the signal of interest (SOI) component exists in the training sequence. In this paper, we present a low-complexity robust adaptive beamforming (RAB) method based on an interference–noise covariance matrix (INCM) reconstruction and SOI SV estimation. First, the proposed method employs the minimum mean square error criterion to construct the blocking matrix. Then, the projection matrix is obtained by projecting the blocking matrix onto the signal subspace of the sample covariance matrix (SCM). The INCM is reconstructed by replacing part of the eigenvector columns of the SCM with the corresponding eigenvectors of the projection matrix. On the other hand, the SOI SV is estimated via the iterative mismatch approximation method. The proposed method only needs to know the priori-knowledge of the array geometry and angular region where the SOI is located. The simulation results showed that the proposed method can deal with multiple types of mismatches, while taking into account both low complexity and high robustness

    IκB Kinase Inhibitor VII Modulates Sepsis-Induced Excessive Inflammation and Cardiac Dysfunction in 5/6 Nephrectomized Mice

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    Background. Chronic kidney disease condition requires regular dialysis; the patients have greater risk of sepsis and have high mortality rate compared to general people with sepsis. The adverse cardiac condition leads to mortality in subjects with sepsis. In the present work, we studied the consequences of chronic kidney damage by 5/6 nephrectomy on cardiac function in mice induced with sepsis and the mechanism involved. Methods. We used C57BL/6 mice and subjected them to 5/6 nephrectomy; after induction of chronic kidney damage, they were subjected to sepsis by either LPS treatment or by cecal ligation and puncture (CLP) method. The cardiac function test was done by echocardiography. Protein expression was done by western blot analysis. Results. The 5/6 nephrectomized mice showed significant increase in blood creatinine and urea levels compared to sham-operated mice; the mice also showed decreased ejection fraction and increased levels of phosphorylated IkBα and nuclear translocation of the NF-κB and inducible nitric oxide synthase (iNOS). When subjected to CLP and LPS treatment, the 5/6 nephrectomized mice augmented cardiac abnormalities and lung inflammation and increased plasma levels of TNF-α, IL-1, IL-12, and IL-18. Also, we evidenced increased levels of p-IKKα/β and Ikβα, NF-κβ, and iNOS. Treatment of IKK inhibitor VII in 5/6 nephrectomized mice after LPS administration or CLP attenuated these effects. Conclusion. Chronic kidney disease could lead to abnormal cardiac function caused by sepsis in mice; this may be due to increased expression of NF-κβ and iNOS in cardiac tissues

    Optimization of Production Conditions for Protoplasts and Polyethylene Glycol-Mediated Transformation of Gaeumannomyces tritici

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    Take-all, caused by Gaeumannomyces tritici, is one of the most important wheat root diseases worldwide, as it results in serious yield losses. In this study, G. tritici was transformed to express the hygromycin B phosphotransferase using a combined protoplast and polyethylene glycol (PEG)-mediated transformation technique. Based on a series of single-factor experimental results, three major factors&mdash;temperature, enzyme lysis time, and concentration of the lysing enzyme&mdash;were selected as the independent variables, which were optimized using the response surface methodology. A higher protoplast yield of 9.83 &times; 107 protoplasts/mL was observed, and the protoplast vitality was also high, reaching 96.27% after optimization. Protoplasts were isolated under the optimal conditions, with the highest transformation frequency (46&ndash;54 transformants/&mu;g DNA). Polymerase chain reaction and Southern blotting detection indicated that the genes of hygromycin phosphotransferase were successfully inserted into the genome of G. tritici. An optimised PEG-mediated protoplast transformation system for G. tritici was established. The techniques and procedures described will lay the foundation for establishing a good mutation library of G. tritici and could be used to transform other fungi
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