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Subsoil liquefaction during strong earthquakes is one of the major seismic threats to the human community. Over the past few decades various methodologies have been proposed to assess liquefaction vulnerability; however, recent seismic events in Japan have revealed that current assessment methods are over conservative, which results in unnecessarily higher costs in mitigation measures. To overcome this situation, this study reinterprets the dynamic behaviour of sandy subsoils subject to recent and historical ground motions from Japanese seismic events and is able to demonstrate that aged soils have a higher liquefaction resistance than suggested by current design codes. Laboratory tests were also devised and conducted to study the mechanism of soil ageing at the particle scale level. Grain dislocations were observed to take place over time while boundary stress conditions maintained constant. These dislocations erased big voids, promoted a more stable granular structure and have the potential to give rise to greater liquefaction resistance. [ABSTRACT FROM AUTHOR]

Structured Abstract Objectives To investigate the effects of IL-17 on IL-6, IL-1β, and matrix metalloproteinase ( MMP-1) production, and to compare the MMP-1 production between the individual and combined effects of IL-1β and IL-6 in human periodontal ligament fibroblasts ( HPDLF). Materials and Methods Human periodontal ligament fibroblasts were cultured with IL-17 for 0.5, 1, 4, 24, 48, and 72 h, and were cultured with IL-1β, IL-6/s IL-6R, or a combination of IL-1β and IL-6/s IL-6R for 24 h. To measure the m RNA levels of IL-6, IL-1β, and MMP-1, total RNA was extracted from the cultured HPDLF, and a real-time PCR analysis was performed. The protein levels of IL-6, IL-1β, and MMP-1 in supernatants were measured using enzyme-linked immunosorbent assays (ELISAs). Results IL-17 significantly increased the expression of IL-6 and MMP-1 m RNA and protein, while IL-17 transiently increased the expression of IL-1β m RNA. The combination of IL-1β and IL-6/ sIL-6R induced significantly higher levels of MMP-1 protein than IL-1β alone. Conclusions IL-17 upregulated the production of IL-6 and MMP-1 sequentially in HPDLF. IL-6/s IL-6R may enhance the effects of IL-1β on MMP-1 production. The present results suggest that IL-17 induces MMP-1 production not only directly, but also indirectly by promoting IL-6 production, thus resulting in the degradation of collagens in the PDL. [ABSTRACT FROM AUTHOR]

This study explores the relationship between feeding habit and craniodental morphology in two closely related sympatric callosciurine squirrels in south-east Asia: Callosciurus erythraeus and Dremomys rufigenis. Both C. erythraeus and D. rufigenis prefer fruits and insects, as generally seen in other tree squirrels. However, C. erythraeus also feeds extensively on hard seeds and tough tree bark, which are rarely included in the diet of D. rufigenis. We tested the hypothesis that C. erythraeus shows structural features in craniodental morphology that provide an advantage for feeding on hard seeds and tough tree bark. Results show that C. erythraeus possesses a greater mechanical advantage of the masseter and temporalis muscles for chewing, and a more robust zygomatic arch, compared with D. rufigenis. Callosciurus erythraeus is capable of generating a greater bite force at a given muscle force at the cheek teeth and its zygomatic arch is more resistant against the stresses generated by the masseter muscle, suggesting adaptation for feeding on hard seeds. Callosciurus erythraeus also exhibits greater leverage of the masseter and temporalis for incision and has a wider skull at the interorbital region, suggesting the capability for efficiently generating a greater bite force and a greater mechanical resistance to increased loads when biting into wood with its anterior dentition. Our findings indicate that the craniodental divergence between C. erythraeus and D. rufigenis may be linked functionally to the differences in their diets. We suggest that their morphological divergence may correlate with their dietary differences and contribute to the sympatric distribution of these closely related squirrels. [ABSTRACT FROM AUTHOR]

Flowering hybrid plants were obtained from reciprocal crosses between N. tabacum L. (2n=48) and N. repanda Willd. (2n = 48), in which cross incompatibility and hybrid inviability were manifested. Stylar pollination and ovule culture were used to overcome the cross incompatibility of stylar barriers and ovular death. It was shown that application of 2 mg/l indole-3-acetic acid (IAA) during the growth period, from the fiveto six-leaf stage to the flowering stage, is a useful and easy method to overcome hybrid inviability. [ABSTRACT FROM AUTHOR]

Two techniques were useful in overcoming hybrid inviability between N. repanda and N. tabacum. These techniques combine gamma-ray irradiation to pollen or to egg cells (in ovules) with in vitro culture of fertilized ovules. When in vitro culture of fertilized ovules from in situ hybridization of N. repanda x N. tabacum was combined without gamma-ray irradiation to pollen or to egg cells (in ovules), all of the resulting seedlings developed chlorosis and died. Furthermore, in the case of in situ hybridization of N. repanda x N. tabacum with gamma-ray irradiated N. tabacum pollen, no viable seeds were obtained. By using both techniques, combining gamma-ray irradiation to N. tabacum pollen or to egg cells in ( N. repanda ovules) with in vitro culture of fertilized ovules, we were successful in obtaining flowering hybrid plants. Thus, it appears that it may be possible to overcome hybrid inviability to a certain extent using both the pollen irradiation technique and the egg cell irradiation technique, i.e., gamma-ray irradiation to pollen or to egg cells (in ovules) before pollination and in vitro culture of fertilized ovules. [ABSTRACT FROM AUTHOR]