Yimeng Li

© 2016 American Society of Plant Biologists. All rights reserved.Calcium/calmodulin-dependent protein kinase has been shown to play an important role in abscisic acid -induced antioxidant defense and enhance the tolerance of plants to drought stress. However, its downstream molecular events are poorly understood. Here, we identify a NAC transcription factor, ZmNAC84, in maize, which physically interacts with ZmCCaMK in vitro and in vivo. ZmNAC84 displays a partially overlapping expression pattern with ZmCCaMK after ABA treatment, and H2O2 is required for ABA-induced ZmNAC84expression. Functional analysis reveals that ZmNAC84 is essential for ABA-induced antioxidant defense in a ZmCCaMK-dependent manner. Furthermore, ZmCCaMK directly phosphorylates Ser-113 of ZmNAC84 in vitro, and Ser-113 is essential for the ABA-induced stimulation of antioxidant defense by ZmCCaMK. Moreover, overexpression of ZmNAC84 in tobacco can improve drought tolerance and alleviate drought-induced oxidative damage of transgenic plants. These results define a mechanism for ZmCCaMK function in ABA-induced antioxidant defense, where ABA-produced H2O2 first induces expression of ZmCCaMK and ZmNAC84 and activates ZmCCaMK. Subsequently, the activated ZmCCaMK phosphorylates ZmNAC84 at Ser-113, thereby inducing antioxidant defense by activating downstream genes.

© 2014 Elsevier B.V.. Nitrogen pollution is a global environmental problem that has greatly increased the risks of both the eutrophication of surface waters and contamination of ground waters. The majority of N pollution mainly comes from agricultural fields, in particular during rice growing seasons. In recent years, a gradual shift from the transplanting rice cultivation method to the direct seeding method has occurred, which results in different water and N losses from paddy fields and leads to distinct impacts on water environments. The N transport and transformations in an experimental direct-seeded-rice field in the Taihu Lake Basin of east China were observed during two consecutive seasons, and simulated using Hydrus-1D model. The observed crop N uptake, ammonia volatilization, N concentrations in soil, and N leaching were used to calibrate and validate the model parameters. The two most important inputs of N, i.e., fertilization and mineralization, were considered in the simulations with 220 and 145.5kgha-1 in 2008 and 220 and 147.8kgha-1 in 2009, respectively. Ammonia volatilization and nitrate denitrification were the two dominant pathways of N loss, accounting for about 16.0% and 38.8% of the total N input, respectively. Both nitrification and denitrification processes mainly occurred in the root zone. N leaching at 60 and 120cm depths accounted for about 6.8% and 2.7% of TNI, respectively. The crop N uptake was 32.1% and 30.8% of TNI during the 2008 and 2009 seasons, respectively, and ammonium was the predominant form. Simulated N concentrations and fluxes in soil matched well with the corresponding observed data. Hydrus-1D could simulate the N transport and transformations in the DSR field, and could thus be a good tool for designing optimal fertilizer management practices in the future.

Lithium sulfide is an attractive cathode material with a high theoretical specific capacity. However, the poor cycle life and rate capability have remained significant challenges, preventing its practical application. Here, Li2S spheres with size control have been synthesized for the first time, and a CVD method for converting them into stable carbon-coated Li2S core-shell particles has been successfully employed. These Li2S@C particles with protective and conductive carbon shells show promising specific capacities and cycling performance with a high initial discharge capacity of 972 mAh g -1 Li2S at the 0.2C rate. Even with no added carbon, a very high Li2S content electrode composed of 98 wt % 1 μm Li2S@C spheres and 2 wt % binder shows rather stable cycling performance, and little morphology change after 400 cycles at the 0.5C rate. © 2014 American Chemical Society.

In the recent decade, increasing costs of labor, water, and fertilizers around the world led to a change in the method of crop establishment from traditional transplanted rice to direct-seeded rice and to a substantial rise in the DSR-managed area. Since water management in areas with DSR is quite different from those with TPR, vertical water movement and water and nutrient losses during the crop season may be different as well. Water flow and water losses in a DSR field in the Taihu Lake Basin of east China were monitored and evaluated using Hydrus-1D during two seasons with different rainfalls and irrigation managements. While during the 2008 season, irrigation accounted for 57% of the total water input, during the 2009 season, it accounted for only 32%. Due to large rainfall during the wet, 2009 rice season, surface runoff accounted for about 17.0% of TWI. During the much drier 2008 rice season with higher irrigation inputs, surface runoff could be controlled much better. Modeled evapotranspiration during the 2008 and 2009 seasons accounted for 54.6% and 44.6% of TWIs, respectively. Measured and simulated results indicate that water leaching was the main path of water loss from the DSR fields, which implies that frequent irrigation increases water leaching. The plough sole layer played a major buffering role for water flow during both dry and wet seasons. Water productivities evaluated from TWIs during the 2008 and 2009 seasons were 0.71 and 0.59kg/m3, respectively; they were 1.30 and 1.33kg/m3 when evaluated from modeled evapotranspiration fluxes. Pressure heads and vertical fluxes simulated using Hydrus-1D matched measured data well. The Hydrus-1D can be used to simulate water flow and water balance in the DSR fields. © 2014 Elsevier B.V.

© 2015 Canadian Cardiovascular Society. Sleep-disordered breathing is one of the most common comorbidities in people with congestive heart failure. Although SDB has major cardiometabolic consequences, the attributable risk of SDB in asymptomatic CHF patients remains unclear. Whether early intervention using positive airway pressure would improve the prognosis in CHF patients is uncertain. As yet, there is insufficient evidence that routine polysomnography screening is cost-effective for asymptomatic CHF patients. Careful clinical risk evaluation and thoughtful use of limited-channel home sleep testing should be considered before the application of routine polysomnography in all CHF patients.

© 2014 Li et al. Aedes albopictus is a very invasive and aggressive insect vector that causes outbreaks of dengue fever, chikungunya disease, and yellow fever in many countries. Vector ecology and disease epidemiology are strongly affected by environmental changes. Urbanization is a worldwide trend and is one of the most ecologically modifying phenomena. The purpose of this study is to determine how environmental changes due to urbanization affect the ecology of Aedes albopictus. Aquatic habitats and Aedes albopictus larval population surveys were conducted from May to November 2013 in three areas representing rural, suburban, and urban settings in Guangzhou, China. Ae. albopictus adults were collected monthly using BG-Sentinel traps. Ae. albopictus larva and adult life-table experiments were conducted with 20 replicates in each of the three study areas. The urban area had the highest and the rural area had the lowest number of aquatic habitats that tested positive for Ae. albopictus larvae. Densities in the larval stages varied among the areas, but the urban area had almost two-fold higher densities in pupae and three-fold higher in adult populations compared with the suburban and rural areas. Larvae developed faster and the adult emergence rate was higher in the urban area than in suburban and rural areas. The survival time of adult mosquitoes was also longer in the urban area than it was in suburban and rural areas. Study regions, surface area, water depth, water clearance, surface type, and canopy coverage were important factors associated with the presence of Ae. albopictus larvae. Urbanization substantially increased the density, larval development rate, and adult survival time of Ae. albopictus, which in turn potentially increased the vector capacity, and therefore, disease transmissibility. Mosquito ecology and its correlation with dengue virus transmission should be compared in different environmental settings.