Distinct soil bacterial patterns along narrow– and broad–scale elevational gradients in grassland of the Mt. Tianshan, China

Bacteria plays a crucial role in soil biogeochemical cycles, bacterial elevational patterns have been well studies over the past decade, but the elevational pattern and its driver poorly understood. To determine the distribution patterns of bacterial composition and diversity across narrow– and broad–scale elevational gradients, we collected soil samples from 22 sites in the grasslands of Mt. Tianshan along three elevational transects and the whole elevation transect: (1) 6 sites at 1047 m – 1587 m, (2) 8 sites at 876 m – 3070 m, and (3) 8 sites at 1602 m – 2110 m. We found a hump pattern of the bacterial community diversity on the whole elevation transect, while not have observed consistent patterns in separately elevation transect. Bacterial community composition based on phylum differed with transects and elevation sites. Furthermore, heatmap analysis showed that pH and MAT significantly (P < 0.05) correlated with bacterial community composition, dominant bacterial phylum and class significantly influenced soil pH. Therefore, our results suggested that soil property plays the most important role in shaping bacterial community patterns in grassland of Mt. Tianshan.

Condylar Contact During Normal Walking and Lateral Trunk Sway Gait: an EMG-Driven Modeling Approach to Estimate Articular Loading

The knee adduction moment has a characteristic double hump pattern with the first peak generally larger than the second. Recently, Mundermann showed that walking with a lateral trunk sway can reduce the 1st peak moment [1]. One might expect from this finding that there would be a decrease in medial compartment loading. This however may be too simplistic a view. Fregly et al. showed that a decrease in knee adduction moment does not guarantee a decrease in medial contact [2]. Moreover, the relationship between net joint moments and loading is not straightforward, especially when agonist/antagonist muscles are co-activated as occurs in patients with pathology. Computational methods can benefit by accounting for subject specific neuromuscular activation patterns while taking into account subject specific dynamics when predicting articular loading. In this paper we outline our EMG-driven modeling approach to predict articular loading during trunk sway for a patient with a force measuring instrumented knee implant. We hypothesized that walking with a lateral trunk sway would: (a) decrease medial contact force, and (b) increase contact force in the lateral compartment.