Modelling methane emissions and grain yields for a double-rice system in Southern China with DAYCENT and DNDC models.

Methane (CH4) is an important greenhouse gas that contributes to climate change and one of its major sources is rice cultivation. The main aim of this paper was to compare two well-established biogeochemical models, namely Daily Century (DAYCENT) and DeNitrification-DeComposition (DNDC) for estimating CH4 emissions and grain yields for a double-rice cropping system with tillage practice and/or stubble incorporation in the winter fallow season in Southern China. Both models were calibrated and validated using field measured data from November 2008 to November 2014. The calibrated models performed effectively in estimating the daily CH4 emission pattern (correlation coefficient, r = 0.58-0.63, p < 0.001), but model efficiency (EF) values were higher in stubble incorporation treatments, with and without winter tillage (treatments S and WS) (EF = 0.22-0.28) than that in winter tillage without stubble incorporation treatment (W) (EF = -0.06-0.08). We recommend that algorithms for the impacts of tillage practice on CH4 emission should be improved for both models. DAYCENT and DNDC also estimated rice yields for all treatments without a significant bias. Our results showed that tillage practice in the winter fallow season (treatments WS and W) significantly decreased annual CH4 emissions, by 13-37 % (p < 0.05) for measured values, 15-20 % (p < 0.05) for DAYCENT-simulated values, and 12-32 % (p < 0.05) for DNDC-simulated values, respectively, compared to no-till practice (treatments S), but had no significant impact on grain yields.

Vangl2 regulates E-cadherin in epithelial cells.

E-cadherin belongs to the classic cadherin subfamily of calcium-dependent cell adhesion molecules and is crucial for the formation and function of epithelial adherens junctions. In this study, we demonstrate that Vangl2, a vertebrate regulator of planar cell polarity (PCP), controls E-cadherin in epithelial cells. E-cadherin co-immunoprecipitates with Vangl2 from embryonic kidney extracts, and this association is also observed in transfected fibroblasts. Vangl2 enhances the internalization of E-cadherin when overexpressed. Conversely, the quantitative ratio of E-cadherin exposed to the cell surface is increased in cultured renal epithelial cells derived from Vangl2(Lpt/+) mutant mice. Interestingly, Vangl2 is also internalized through protein traffic involving Rab5- and Dynamin-dependent endocytosis. Taken together with recent reports regarding the transport of Frizzled3, MMP14 and nephrin, these results suggest that one of the molecular functions of Vangl2 is to enhance the internalization of specific plasma membrane proteins with broad selectivity. This function may be involved in the control of intercellular PCP signalling or in the PCP-related rearrangement of cell adhesions.