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Summary: Associations of adiposity indices with bone mineral density (BMD) and bone turnover markers were evaluated in Chinese participants. Body mass index, fat mass, and lean mass are positively related to BMD in both genders. Subcutaneous fat area was proved to be negatively associated with BMD and positively correlated with osteocalcin in postmenopausal females. Introduction: Obesity is highly associated with osteoporosis, but the effect of adipose tissue on bone is contradictory. Our study aimed to assess the associations of adiposity indices with bone mineral density (BMD) and bone turnover markers (BTMs) in the Chinese population. Methods: Our study recruited 5215 participants from the Shanghai area, evaluated related anthropometric and biochemical traits in all participants, tested serum BTMs, calculated fat distribution using magnetic resonance imaging (MRI) images and image analysis software, and tested BMD with dual-energy X-ray absorptiometry. Results: When controlled for age, all adiposity indices were positively correlated with BMD of all sites for both genders. As for the stepwise regression analysis, body mass index (BMI), fat mass, and lean mass were protective for BMD in both genders. However, subcutaneous fat area (SFA) was detrimental for BMD of the L1-4 and femoral neck ( β ± SE −0.0742 ± 0.0174; p = 2.11E−05; β ± SE −0.0612 ± 0.0147; p = 3.07E−05). Adiposity indices showed a negative correlation with BTMs adjusting for age, especially with osteocalcin. In the stepwise regression analysis, fat mass was negatively correlated with osteocalcin ( β ± SE −8.8712 ± 1.4902; p = 4.17E−09) and lean mass showed a negative correlation with N-terminal procollagen of type I collagen (PINP) for males ( β ± SE −0.3169 ± 0.0917; p = 0.0006). In females, BMI and visceral fat area (VFA) were all negatively associated with osteocalcin ( β ± SE −0.4423 ± 0.0663; p = 2.85E−11; β ± SE −7.1982 ± 1.1094; p = 9.95E−11), while SFA showed a positive correlation with osteocalcin ( β ± SE: 5.5993 ± 1.1753; p = 1.98E−06). Conclusion: BMI, fat mass, and lean mass are proved to be beneficial for BMD in both males and postmenopausal females. SFA is negatively associated with BMD and positively correlated with osteocalcin in postmenopausal females. [ABSTRACT FROM AUTHOR]

Landslide dams in mountainous areas are quite common. Typically, intense rainfalls can induce upstream flows along the sloping channel, which greatly affects the stability and failure modes of landslide dams. If a series of landslide dams are sequentially collapsed by an incoming mountain torrent (induced by intense rainfall), large debris flows can be formed in a short period of time. This also amplifies the magnitude of the debris flows along the flow direction. The catastrophic debris flows, which occurred in Zhouqu, China on August 8, 2010, were indeed caused by intense rainfall and the upstream cascading failure of landslide dams along the gullies. Experimental tests were conducted in a sloping channel to understand the dynamic process of cascading landslide dam failures and their effect on flow scale amplification. Similar to the Zhouqu conditions, the modeled landslide dams were distributed along a sloping channel and breached by different upstream flows. For each experiment, the front flows were sampled, the entrained grain sizes were analyzed, and the front discharge along the channel was measured. The results of these experiments show that landslide dams occurring along the channel can be destroyed by both high and low discharge flows, although the mechanisms are quite different for the two flow types. Regardless of flow type, the magnitude of the flows significantly increases after a cascading failure of landslide dams, resulting in an increase in both the diameter and the entrained coarse particles percentage. [ABSTRACT FROM AUTHOR]