592 research outputs found

    Three-Dimensional Response Spectra for Multiple-Support Input Motions

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    New response spectra for multiple-support input motions are presented to study the seismic responses of long-span bridges. Three-dimensional response spectra are defined using the response of simple beams with various natural periods. These spectra clearly verify the dominant vibration mode and the critical location of the maximum response. Numerical examples using the earthquake records observed by a newly-installed array at the Akashi Kaikyo bridge construction site in Japan show that the different input motions to each support produce different predominant vibration modes compared with the identical excitation case. It has also been observed that response usually decreases when multiple-support input motions with phase lags are considered. The ordinary response spectra method is also examined and it has been found that the approximated values using the RMS method overestimated the maximum response

    Seismic Damage Assessment of RC Structures using Different Hysteretic Models

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    Estimation of seismic damage of a structure varies depending on the assumed hysteretic rules and input excitations due to indices being calculated from earthquake response time histories. In this study, effects of the different hysteretic models on damage indices were studied. First, the response of RC bridge piers during earthquakes was calculated using different hysteretic models and input motions. Then, seismic damage was evaluated by 1) a damage index based on a linear combination of the maximum deformation ratio and the energy dissipation during cyclic loadings, and 2) damage spectra of damage index, ductility and absorbed hysteretic energy for structures with various natural periods. Results showed that the non-degrading maximum value directed model was accurate enough for seismic damage analysis while the bilinear model underestimated damage because of its linear response to the low intensity cyclic loadings. The maximum value directed model was also needed to predict the damage index from the maximum velocity or the spectral intensity of the input motions

    Synergistic Pathogenic Effects of Combined Mouse Monoclonal Anti-Desmoglein 3 IgG Antibodies on Pemphigus Vulgaris Blister Formation

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    Pemphigus vulgaris (PV) is an autoimmune blistering disease caused by anti-desmoglein 3 (Dsg3) IgG antibodies. Previously, we generated an active mouse model for PV by adoptive transfer of splenocytes from immunized or naive Dsg3−/− mice. In this study, we isolated 10 anti-Dsg3 IgG mAbs (NAK-series) from PV model mice generated by transfer of naive Dsg3−/− splenocytes. We characterized their epitopes using domain-swapped and point-mutated Dsg1/Dsg3 molecules and examined their pathogenic activities in blister formation in three different assays. In a passive transfer model using neonatal mice, eight of 10 NAK mAbs showed pathogenic activity when injected together with half the minimum pathogenic dose of anti-Dsg1 IgG autoantibodies from pemphigus foliaceus (PF) patients. None of the mAbs could induce the PV phenotype when individual hybridoma clones were inoculated by peritoneal injection into adult Rag2−/− mice. NAK mAbs displayed a range of potency in an in vitro dissociation assay using primary cultured mouse keratinocytes. Interestingly, when multiple hybridoma clones recognizing different epitopes were inoculated in combination, recipient mice developed the PV phenotype. In vitro dissociation assays confirmed that combined NAK mAbs had synergistic pathogenic effects. These findings indicate that although an individual anti-Dsg3 IgG is not sufficient to cause blistering in adult mice, several together can induce the PV phenotype. These mAbs will provide a valuable tool to investigate the molecular mechanisms of blister formation, mimicking the effects of the polyclonal IgG antibodies found in patients

    Polymorphic Microsatellite Loci in the Independent-founding Wasp Polists versicolor (Hymenoptera: Vespidae)

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    Microsatellite primers developed for a given species are sometimes useful for another in the same genus, making possible to search for pre-existing suitable primers in the data banks such as GenBank. We examined whether existing primers developed for Polistes wasps could be used for the independent-founding wasp Polistes versicolor. We tested 50 microsatellite primers from three Polistes species and found that five microsatellite loci show polymorphism in size in P. versicolor. These five loci were highly polymorphic, having four to 10 alleles in P. versicolor with an expected heterozygosity of 0.530–0.836. These loci can be used to study parameters concerning genetic relatedness such as social interactions in colonies and genetic conflicts of interest among nestmate individuals

    Peroxisome proliferator-activated receptor δ as a molecular target to regulate lung cancer cell growth

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    AbstractIt has been assumed that prostaglandin (PG)I2 signaling contributes to the negative growth control of lung cancer cells; however, the mechanism remains unresolved. PGI2 functions through a cell surface G protein-coupled receptor (prostaglandin I2-binding receptor, IP) and also exerts an effect by interacting with a nuclear hormone receptor, peroxisome proliferator-activated receptor δ (PPARδ). We found that PPARδ was a key molecule of PGI2 signaling to give negative growth control of lung cancer cells (A549), using carbarprostacyclin, a PGI2 agonist for IP and PPARδ, and L-165041, a PPARδ agonist. Furthermore, PPARδ-induced cell growth control was reinforced by the inhibition of cyclooxygenase. These results suggest that PPARδ activation under the suppression of PG synthesis is important to regulate lung cancer cell growth
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