1,370 research outputs found

    Indole contributes to tetracycline resistance via the outer membrane protein OmpN in Vibrio splendidus

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    As an interspecies and interkingdom signaling molecule, indole has recently received attention for its diverse effects on the physiology of both bacteria and hosts. In this study, indole increased the tetracycline resistance of Vibrio splendidus. The minimal inhibitory concentration of tetracycline was 10 mu g/mL, and the OD600 of V. splendidus decreased by 94.5% in the presence of 20 mu g/mL tetracycline; however, the OD600 of V. splendidus with a mixture of 20 mu g/mL tetracycline and 125 mu M indole was 10- or 4.5-fold higher than that with only 20 mu g/mL tetracycline at different time points. The percentage of cells resistant to 10 mu g/mL tetracycline was 600-fold higher in the culture with an OD600 of approximately 2.0 (higher level of indole) than that in the culture with an OD600 of 0.5, which also meant that the level of indole was correlated to the tetracycline resistance of V. splendidus. Furthermore, one differentially expressed protein, which was identified as the outer membrane porin OmpN using SDS-PAGE combined with MALDI-TOF/TOF MS, was upregulated. Consequently, the expression of the ompN gene in the presence of either tetracycline or indole and simultaneously in the presence of indole and tetracycline was upregulated by 1.8-, 2.54-, and 6.01-fold, respectively, compared to the control samples. The combined results demonstrated that indole enhanced the tetracycline resistance of V. splendidus, and this resistance was probably due to upregulation of the outer membrane porin OmpN

    Extremely cold and hot temperatures increase the risk of ischaemic heart disease mortality: epidemiological evidence from China.

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    OBJECTIVE: To examine the effects of extremely cold and hot temperatures on ischaemic heart disease (IHD) mortality in five cities (Beijing, Tianjin, Shanghai, Wuhan and Guangzhou) in China; and to examine the time relationships between cold and hot temperatures and IHD mortality for each city. DESIGN: A negative binomial regression model combined with a distributed lag non-linear model was used to examine city-specific temperature effects on IHD mortality up to 20 lag days. A meta-analysis was used to pool the cold effects and hot effects across the five cities. PATIENTS: 16 559 IHD deaths were monitored by a sentinel surveillance system in five cities during 2004-2008. RESULTS: The relationships between temperature and IHD mortality were non-linear in all five cities. The minimum-mortality temperatures in northern cities were lower than in southern cities. In Beijing, Tianjin and Guangzhou, the effects of extremely cold temperatures were delayed, while Shanghai and Wuhan had immediate cold effects. The effects of extremely hot temperatures appeared immediately in all the cities except Wuhan. Meta-analysis showed that IHD mortality increased 48% at the 1st percentile of temperature (extremely cold temperature) compared with the 10th percentile, while IHD mortality increased 18% at the 99th percentile of temperature (extremely hot temperature) compared with the 90th percentile. CONCLUSIONS: Results indicate that both extremely cold and hot temperatures increase IHD mortality in China. Each city has its characteristics of heat effects on IHD mortality. The policy for response to climate change should consider local climate-IHD mortality relationships

    Examining the Effects of Preschool Writing Instruction on Emergent Literacy Skills: A Systematic Review of the Literature

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    This article presents the results of a systematic review of the literature involving writing interventions in the preschool setting. The information presented is timely considering the current expectations for young children to write. Framing the empirical literature within different philosophical approaches, trends were analyzed to identify instructional strategies related to increases in emergent literacy outcomes and where gaps in the literature existed. The results from 22 intervention conditions from 1990 to 2013 indicated the overall effect size was g = .44, 95% CIs [.27, .60], suggesting that preschool writing interventions enhanced children’s early literacy outcomes. The findings also highlighted the importance of quality literacy environments and adult involvement. The findings from this article have important instructional implications for writing instruction in the preschool setting

    Techno-invasion and job satisfaction in China: The roles of boundary preference for segmentation and marital status

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    BACKGROUND: While the intensive work-related use of information and communication technologies after working hours have led to increased techno-invasion, much less is known regarding whether and for whom techno-invasion influences job satisfaction. OBJECTIVE: Drawing on the conservation of resources theory and person-environment fit theory, this study examined the relationship between techno-invasion and decreased job satisfaction. Specific attention was paid to the moderating effect of boundary preference for segmentation and its joint influence with marital status on this relationship. METHODS: Questionnaire data were collected by an online survey of a nationwide and diverse sample of 472 employees from China. Data were analyzed using descriptive statistics, confirmatory factor analysis and hierarchical regression analysis. RESULTS: We found that techno-invasion negatively correlated with job satisfaction, which was strengthened by boundary preference for segmentation. Furthermore, the results of a three-way interaction effect suggested that the moderating role of boundary preference for segmentation on the relationship between techno-invasion and job satisfaction is stronger for unmarried employees than it is for married ones. CONCLUSIONS: The effect of techno-invasion on employees’ job satisfaction can be strengthened or weakened by their boundary preference for segmentation and marital status
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