We evaluated exposure to canine distemper virus (CDV) in eight wild giant pandas (Ailuropoda melanoleuca) and 125 unvaccinated domestic dogs living in and around Foping National Nature Reserve (FNNR), China. Seventy-two percent of unvaccinated domestic dogs (mixed breed) had neutralizing antibodies for CDV due to exposure to the disease. The eight wild giant pandas were naïve to CDV and carried no positive antibody titer. RT-PCR assays for hemagglutinin (H) gene confirmed the presence of CDV in 31 clinically ill dogs from several areas near FNNR. Genomic sequence analysis showed that the 21 canine CDV were highly homologous to each other and belonged to the Asian-1 genotype. They showed high homology with the GP01 strain sequenced from a fatally infected giant panda, suggesting cross-species infection. Observational and GPS tracking data revealed home range overlap in pandas and dogs around FNNR. This study shows that CDV is endemic in domestic dogs near FNNR and that cross-species CDV infection threatens the wild giant panda population.

Abstract. While the elevated ambient levels of particulate matters with aerodynamic diameter of 2.5 µm or less (PM2.5) are alleviated largely with the implementation of effective emission control measures, an opposite trend with a rapid increase has been seen in surface ozone (O3) in the North China Plain (NCP) region over the past several years. It is critical to determine the real culprit causing such a large increase in surface O3. In this study, 7-year surface observations and satellite retrieval data are analyzed to determine the long-term change in surface O3 as well as driving factors. Results indicate that anthropogenic emission control strategies and changes in aerosol concentrations as well as aerosol optical properties such as single-scattering albedo (SSA) are the most important factors driving such a large increase in surface O3. Numerical simulations with the National Center for Atmospheric Research (NCAR) Master Mechanism (MM) model suggest that reduction of O3 precursor emissions and aerosol radiative effect accounted for 45 % and 23 % of the total change in surface O3 in summertime during 2013–2019, respectively. Planetary boundary layer (PBL) height with an increase of 0.21 km and surface air temperature with an increase of 2.1 ∘C contributed 18 % and 12 % to the total change in surface O3, respectively. The combined effect of these factors was responsible for the rest of the change. Decrease in SSA or strengthened absorption property of aerosols may offset the impact of aerosol optical depth (AOD) reduction on surface O3 substantially. While the MM model enables quantification of an individual factor's percentage contributions, it requires further refinement with aerosol chemistry included in the future investigation. The study indicates an important role of aerosol radiative effect in development of more effective emission control strategies on reduction of ambient levels of O3 as well as alleviation of national air quality standard exceedance events.

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The authors report the observation of intersubband absorptions in ZnO/ZnMgO multiple quantum wells (QWs). The multiple QW structures were grown on c-plane sapphire substrates by plasma-assisted molecular beam epitaxy. The high structural and optical properties of the samples were demonstrated by high-resolution x-ray diffraction and photoluminescence measurements. At room temperature, intersubband absorptions at ∼3 μm were observed.

We report the experimental demonstration of a room temperature, high responsivity, short wavelength II-VI Zn0.51Cd0.49Se/Zn0.29Cd0.26Mg0.45Se based quantum well infrared photodetector operating between 3 and 5 μm. Spectral response was observed up to room temperature with a cut off wavelength of 5 μm at 280 K. Measurements with a calibrated blackbody source yielded a peak responsivity of over 30 A/W at 280 K and an applied bias of −3 V. The dark current limited peak detectivity at 80 K and 280 K were measured to be 2 × 109 cm √Hz/W and 4 × 107 cm √Hz/W, respectively. These results are consistent with theoretical calculations that predict a maximum detectivity of the order of 107 cm √Hz/W at room temperature for typical carrier lifetimes and optimized doping levels.