Functional characterization of alkaline phosphatases involved alarm pheromone in the vetch aphid Megoura viciae.

The alkaline phosphatases (ALPs) are highly promiscuous enzymes and have been extensively investigated in mammals for their medical significance, but their functional promiscuity is relatively poorly understood in insects. Here, we first identified four ALP genes (designated as MvALP1-4) in the vetch aphid Megoura viciae that contained one alkaline phosphatase site, three metal-binding sites, and varied other functional sites. Phylogenetic analysis, molecular docking and the spatiotemporal expression profiling of MvALP1-4 were very different, indicating a promiscuous functionality. We also found that MvALP4 involved the biosynthesis of aphid alarm pheromones (EßF) in vitro and in vivo. Finally, transcriptome analysis in the stimulated and unstimulated aphids supported the involvement of MvALPs in the biosynthesis of aphid alarm pheromones. Our study identified a multifunctional ALP involved terpene synthase enzyme activity in the aphid, which contributes to the understanding of the functional plasticity of ALPs in insects.

[Atmospheric Correction for HJ-1 CCD Data Coupling with Aerosol Models of Beijing-Tianjin-Hebei Region].

Current atmospheric correction of HJ-1 CCD does not take the aerosol models of Chinese specific regions into consideration. This paper proposes a method of atmospheric correction coupling local aerosol models. Choosing Beijing-Tianjin-Hebei region as the study area, aerosol model parameters of the method on the foundation of AERONET inversion are analyzed and four types of aerosol model parameters of Beijing-Tianjin- Hebei regions are clustered to build the lookup table for the inversion of aerosol optical thickness. Lack of SWIR (2.12 µm) in the bands of HJ-1 CCD , the blue(0.43~0.52 µm) and red(0.63~0.69 µm) cannot be calculated like the MODIS. So the ratio of blue and red is used as the basis of error equation for aerosol optical depth retrieval, with no need of ground target reflectance. HJ-1 CCD data after atmospheric correction are compared with MODIS surface product data (MOD09) and ASD measurements. The results show that the reflectance obtained by the atmospheric correction is close to the ASD measurement results, and there is a strong correlation with MOD09, the average correlation coefficient in the red band reached more than 0.8, the one of blue band affected by molecule mostly is up to 0.75.

[Variation characteristics of total gaseous mercury at Wuzhi mountain (Wuzhishan) background station in Hainan].

Total gaseous mercury (TGM) was continuously monitored at Wuzhi mountain (Wuzhishan) using the high-resolution automatic atmospheric mercury vapor analyzer (Tekran 2537B) from May 2011 to May 2012. The annual geometric mean TGM concentration was (1.58 ± 0.71) ng x m(-3), suggesting that the atmosphere was not obviously polluted. The TGM level at WuZhi mountain remained low from June to August in 2011 and from March to May in 2012, while higher values were observed from September in 2011 to January in 2012. Tropical monsoons played an important role in the monthly variation of TGM. TGM concentrations showed a clear diurnal trend with the minimum concentration occurring at 09:00 AM and the peak concentration at 19:00 PM due to the combined impact of the long-range transport of atmospheric mercury and local meteorological conditions. The temporal trend of TGM highlighted the impact of long-range transport from the mainland of China on the distribution of TGM in ambient air at Wuzhi mountain by the results of backward trajectory analysis using HYSPLIT.

[A review of atmospheric aerosol research by using polarization remote sensing].

In the present paper, aerosol research by using polarization remote sensing in last two decades (1993-2013) was reviewed, including aerosol researches based on POLDER/PARASOL, APS(Aerosol Polarimetry Sensor), Polarized Airborne camera and Ground-based measurements. We emphasize the following three aspects: (1) The retrieval algorithms developed for land and marine aerosol by using POLDER/PARASOL; The validation and application of POLDER/PARASOL AOD, and cross-comparison with AOD of other satellites, such as MODIS AOD. (2) The retrieval algorithms developed for land and marine aerosol by using MICROPOL and RSP/APS. We also introduce the new progress in aerosol research based on The Directional Polarimetric Camera (DPC), which was produced by Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences (CAS). (3) The aerosol retrieval algorithms by using measurements from ground-based instruments, such as CE318-2 and CE318-DP. The retrieval results from spaceborne sensors, airborne camera and ground-based measurements include total AOD, fine-mode AOD, coarse-mode AOD, size distribution, particle shape, complex refractive indices, single scattering albedo, scattering phase function, polarization phase function and AOD above cloud. Finally, based on the research, the authors present the problems and prospects of atmospheric aerosol research by using polarization remote sensing, and provide a valuable reference for the future studies of atmospheric aerosol.

[The research on remote sensing dust aerosol by using split window emissivity].

Dust aerosol can cause the change in the land surface emissivity in split window by radiative forcing (RF). Firstly, the present paper explained from the microscopic point of view the extinction properties of dust aerosols in the 11 and 12 microm channels, and their influence on the land surface emissivity. Secondly, on April 29, 2011, in the northern region of Inner Mongolia a strong sandstorm outbroke, and based on the analysis of the changes in land surface emissivity, this paper proposed a dust identification method by using the variation of emissivity. At last, the dust identification result was evaluated by the dust monitoring product provided by the National Satellite Meteorological Center. The result shows that under the assumption that the 12 microm emissivity equals to 1, using 11 microm relative emissivity could identify dust cover region effectively, and the 11 microm relative emissivity to a certain extent represented the intensity information of dust aerosol.

[Simulation and analysis of polarization characteristics for real sea surface sunglint].

The sea surface sunglint is caused by specular reflectance. Water is a kind of dark target with a very low reflectance, so sunglint becomes a big noise in the aerial or aerospace remote sensing images; sunglint is strongly polarized, and can be a natural standard light source for polarized sensor in-flight calibration; sunglint also can be utilized to retrieve gaseous constituents and aerosol properties. For both de-noising and being standard light source, the radiative physic parameters should be calculated accurately. First, A 3-D sea surface model was constituted according to the Cox & Munk model; Second, the polarized radiative model of sunglint was deduced based on the 3-D sea surface model and polarized Fresnel reflectance law; Third, the sensitivities of solar-viewing relative azimuth, zenith, wind speed and wind direction were analyzed utilizing the polarized radiative model. The polarization characteristics analysis of sunglint provides a theoretical basis for the quantitative remote sensing retrievals which uses sunglint.