Vibration frequencies extraction of the Forth Road Bridge using high sampling GPS data

This paper proposes a scheme for vibration frequencies extraction of the Forth Road Bridge in Scotland from high sampling GPS data. The interaction between the dynamic response and the ambient loadings is carefully analysed. A bilinear Chebyshev high-pass filter is designed to isolate the quasistatic movements, the FFT algorithm and peak-picking approach are applied to extract the vibration frequencies, and a GPS data accumulation counter is suggested for real-time monitoring applications. To understand the change in the structural characteristics under different loadings, the deformation results from three different loading conditions are presented, that is, the ambient circulation loading, the strong wind under abrupt wind speed change, and the specific trial with two 40 t lorries passing the bridge. The results show that GPS not only can capture absolute 3D deflections reliably, but also can be used to extract the frequency response accurately. It is evident that the frequencies detected using the filtered deflection time series in different direction show quite different characteristics, and more stable results can be obtained from the height displacement time series. The frequency responses of 0.105 and 0.269Hz extracted from the lateral displacement time series correlate well with the data using height displacement time series

Peroxisome Proliferator-activated Receptor γ Suppresses Proximal α1(I) Collagen Promoter via Inhibition of p300-facilitated NF-I Binding to DNA in Hepatic Stellate Cells

Depletion of peroxisome proliferator-activated receptor gamma (PPARgamma) represents one of the key molecular changes that underlie transdifferentiation (activation) of hepatic stellate cells in the genesis of liver fibrosis (Miyahara, T., Schrum, L., Rippe, R., Xiong, S., Yee, H. F., Jr., Motomura, K., Anania, F. A., Willson, T. M., and Tsukamoto, H. (2000) J. Biol. Chem. 275, 35715-35722; Hazra, S., Xiong, S., Wang, J., Rippe, R. A., Krishna, V., Chatterjee, K., and Tsukamoto, H. (2004) J. Biol. Chem. 279, 11392-11401). In support of this notion, ectopic expression of PPARgamma suppresses hepatic stellate cells activation markers, most notably expression of alpha1(I) procollagen. However, the mechanisms underlying this antifibrotic effect are largely unknown. The present study utilized deletion-reporter gene constructs of proximal 2.2-kb alpha1(I) procollagen promoter to demonstrate that a region proximal to -133 bp is where PPARgamma exerts its inhibitory effect. Within this region, two DNase footprints with Sp1 and reverse CCAAT box sites exist. NF-I, but not CCAAT DNA-binding factor/NF-Y, binds to the proximal CCAAT box in hepatic stellate cells. A mutation of this site almost completely abrogates the promoter activity. NF-I mildly but independently stimulates the promoter activity and synergistically promotes Sp1-induced activity. PPARgamma inhibits NF-I binding to the most proximal footprint (-97/-85 bp) and inhibits its transactivity. The former effect is mediated by the ability of PPARgamma to inhibit p300-facilitated NF-I binding to DNA as demonstrated by chromatin immunoprecipitation assay

Hemojuvelin-Neogenin Interaction Is Required for Bone Morphogenic Protein-4-induced Hepcidin Expression

Hemojuvelin (HJV) is a glycosylphosphatidylinositol-linked protein and binds both bone morphogenic proteins (BMPs) and neogenin. Cellular HJV acts as a BMP co-receptor to enhance the transcription of hepcidin, a key iron regulatory hormone secreted predominantly by liver hepatocytes. In this study we characterized the role of neogenin in HJV-regulated hepcidin expression. Both HJV and neogenin were expressed in liver hepatocytes. Knockdown of neogenin decreased BMP4-induced hepcidin mRNA levels by 16-fold in HJV-expressing HepG2 cells but only by about 2-fold in cells transfected with either empty vector or G99V mutant HJV that does not bind BMPs. Further studies indicated that disruption of the HJV-neogenin interaction is responsible for a marked suppression of hepcidin expression. Moreover, in vivo studies showed that hepatic hepcidin mRNA could be significantly suppressed by blocking the interaction of HJV with full-length neogenin with a soluble fragment of neogenin in mice. Together, these results suggest that the HJV-neogenin interaction is required for the BMP-mediated induction of hepcidin expression when HJV is expressed. Combined with our previous studies, our results support that hepatic neogenin possesses two functions, mediation of cellular HJV release, and stimulation of HJV-enhanced hepcidin expression

Peroxisome Proliferator-activated Receptor γ Induces a Phenotypic Switch from Activated to Quiescent Hepatic Stellate Cells

Depletion of peroxisome proliferator-activated receptor gamma (PPARgamma) accompanies myofibroblastic transdifferentiation of hepatic stellate cells (HSC), the primary cellular event underlying liver fibrogenesis. The treatment of activated HSC in vitro or in vivo with synthetic PPARgamma ligands suppresses the fibrogenic activity of HSC. However, it is uncertain whether PPARgamma is indeed a molecular target of this effect, because the ligands are also known to have receptor-independent actions. To test this question, the present study examined the effects of forced expression of PPARgamma via an adenoviral vector on morphologic and biochemical features of culture-activated HSC. The vector-mediated expression of PPARgamma itself is sufficient to reverse the morphology of activated HSC to the quiescent phenotype with retracted cytoplasm, prominent dendritic processes, reduced stress fibers, and accumulation of retinyl palmitate. These effects are abrogated by concomitant expression of a dominant negative mutant of PPARgamma that prevents transactivation of but not binding to the PPAR response element. PPARgamma expression also inhibits the activation markers such as the expression of alpha-smooth muscle actin, type I collagen, and transforming growth factor beta1; DNA synthesis; and JunD binding to the activator protein-1 (AP-1) site and AP-1 promoter activity. Inhibited JunD activity by PPARgamma is not due to reduced JunD expression or JNK activity or to a competition for p300. But it is due to a JunD-PPARgamma interaction as demonstrated by co-immunoprecipitation and glutathione S-transferase pull-down analysis. Further, the use of deletion constructs reveals that the DNA binding region of PPARgamma is the JunD interaction domain. In summary, our results demonstrate that the restoration of PPARgamma reverses the activated HSC to the quiescent phenotype and suppresses AP-1 activity via a physical interaction between PPARgamma and JunD

Intercropping Vicia sativa L. Improves the Moisture, Microbial Community, Enzyme Activity and Nutrient in Rhizosphere Soils of Young Kiwifruit Plants and Enhances Plant Growth

Drought, low nutrition, and weeds have become the major limiting factors of young kiwifruit orchards. In this study, the effects of intercropping Vicia sativa L. on the moisture, microbe community, enzyme activity, and nutrients in rhizosphere soils of young kiwifruit plants and their growth were investigated. The results show that intercropping V. sativa could effectively enhance soil moisture by 1.39–1.47 folds compared with clean tillage. Moreover, intercropping V. sativa could significantly (p < 0.01) increase the microbial community, enzyme activity and nutrient of kiwifruit rhizosphere soils, and improve plant height, stem girth, leaf number, maximum leaf length, maximum leaf width, and chlorophyll content of young kiwifruit plants by 43.60%, 18.68%, 43.75%, 18.09%, 21.15%, and 67.57% compared to clean tillage, respectively. The moisture, microbial quantity, enzyme activity, and nutrients in rhizosphere soils of young kiwifruit plants exhibited good correlations with their plant height, stem girth, leaf number, maximum leaf length, maximum leaf width, and chlorophyll content. This study highlights that intercropping V. sativa in young kiwifruit orchard can be used as an effective, labor-saving, economical and sustainable practice to improve the moisture, microbial community, enzyme activity, and nutrient of soils, and enhance kiwifruit plant growth and control weeds