Xiaolangdi 貯水池の水中の微量物質に関する研究

As one of the strategic projects, Xiaolangdi Dam Project has many functions, including flood control, water supply for municipal and irrigation, etc. And water quality of Xiaolangdi reservoir will directly affects industrial and agricultural production and health of residents in the reservoir area and downstream areas. So the fate of toxic heavy metals in water of the Xiaolangdi is highly concerned. Samples of surface water from Mingzhudao and Zhangling in the Xiaolangdi reservoir，were analyzed to assess the water quality. Nine trace elements, including Hg, Se, Cd，Cr, Cu, Zn, Fe, Mn and F were determined. Concentrations of As, Cr, Cu, and Zn were lower than the detection limit in the Xiaolangdi water. The mean concentration of mercury in the studied areas was higher than the III class of Chinese surface water quality standards limit, while other elements were lower than the limit. And the concentration of mercury increases as water depth increases，it may be due to sedimentation of mercury micro-organisms or biogeochemical cycle of mercury. Se and Cd in the Xiaolangdi Reservoir were distributed evenly, and their contents changed little with water depth.特集 : 「資源、新エネルギー、環境、防災研究国際セミナー

Preliminary Study on Environmental Geochemistry in the Paleo-sediment of the Yellow River of Wuzhi, China

This work studied trace elements in the paleo-sediment of the Yellow River of Wuzhi, Jiaozuo, Henan Province, using the flame atomic absorption spectrometry and atomic fluorescence spectrometry to analyze the concentration of trace elements (Cu、Ni、Mn、Zn、Pb、Cr、Fe、As). The concentrations of the eight trace elements in the paleo-sediment of the Yellow River ranged between 6.42 and 28.35 mg·kg-1 (mean 15.09 mg·kg-1), 13.69 and 39.24 mg·kg-1 (21.31 mg·kg-1), 158.8 and 338.65 mg·kg-1 (219.56 mg·kg-1), 178.25 and 309.75 mg·kg-1 (239.49 mg·kg-1), 14.16 and 27.19 mg·kg-1 (20.22 mg·kg-1), 27.25 and 67.71 mg·kg-1 (37.84 mg·kg-1), 17830 and 34080 mg·kg-1 (25942 mg·kg-1) and 26.315 and 532.01 mg·kg-1 (141.71 mg·kg-1), respectively. The results showed that the impact of human activities is one of the main factors, especially the destruction of natural vegetation of the middle reaches of Loess Plateau in the Qin and Han Dynasties and the development of industry and agriculture.特集 : 「資源、新エネルギー、環境、防災研究国際セミナー

Detoxification Center-Based Sampling Missed a Subgroup of Higher Risk Drug Users, a Case from Guangdong, China

BACKGROUND: Injection drug use remains among the most important HIV transmission risk in China. Representativeness of drug users sampled from detoxification centers is questionable. A respondent driven sampling survey was conducted to compare the results with those from the detoxification center in the same city. METHODS: In 2008, two independent surveys were conducted in Dongguan, China, one for community-based drug users using respondent driven sampling and the other for drug users in a compulsory detoxification center as routine sentinel surveillance. Demographic and behavioral information were collected using the same structured questionnaire. Intravenous blood samples were collected to measure antibodies to HIV-1, and syphilis. RESULTS: Compared to those 400 drug users recruited from the detoxification center, the 303 community-based drug users had higher HIV prevalence (14.7% versus 4.0%, P = 0.04), lower syphilis prevalence (4.7% versus 10.8%, P = 0.07), higher proportion of injection drug use (83.9% versus 60.2%, P = 0.01) and syringe sharing (47.8% versus 36.3%, P = 0.10), more likely to be separated (12.4% versus 3.8%, P = 0.01) and being migrants from Guangxi province (31.4% versus 18.0%, P = 0.09), more engaging in commercial sex (64.4% versus 52.5%, P = 0.04). HIV prevalence and rate of syringe sharing were consistently higher among drug users from Guangxi. CONCLUSIONS: Detoxification center-based sampling missed a subgroup with higher HIV prevalence and higher rate of injection drug use. While detoxification center-based sampled can be used to monitor the trend of HIV prevalence and risk behaviors over time, periodic community-based sampling is still necessary to avoid possible systematic error in detoxification center-based samples

Monitoring the Process and Characterizing Symptoms of Suckling Mouse Inoculation Promote Isolating Viruses from Ticks

Suckling mouse inoculation is an important method that has been used for years to isolate viruses from ticks; however, this method has usually been briefly described in the literature on a case-by-case basis upon successful isolation rather than providing extensive details. This study describes the procedure from preparation of tick homogenates to identification of virus isolation using the suckling mouse inoculation method. The transient and persistent features were characterized and the incidence of manifestations that developed in the suckling mice, especially in mice from which viruses were isolated, is reported. We identified 22 symptoms that developed in mice, including 13 transient symptoms that recovered by the end of the observation period and 7 persistent symptoms that the mice suffered from throughout the observation period. Persistent symptoms (lateral positioning and dead) and transient symptoms (malaise, emaciation, and difficulty turning over) were the main symptoms based on the high overall incidence. Moreover, we showed that mice from which viruses were isolated had a concentrated period and advanced days of disease onset. This study provides detailed information necessary for better use of suckling mouse inoculation to isolate viruses from ticks, which may benefit optimization of this method to identify, discover, and acquire tick-borne viruses

Primal-Dual Splitting Algorithms for Solving Structured Monotone Inclusion with Applications

This work proposes two different primal-dual splitting algorithms for solving structured monotone inclusion containing a cocoercive operator and the parallel-sum of maximally monotone operators. In particular, the parallel-sum is symmetry. The proposed primal-dual splitting algorithms are derived from two approaches: One is the preconditioned forward–backward splitting algorithm, and the other is the forward–backward–half-forward splitting algorithm. Both algorithms have a simple calculation framework. In particular, the single-valued operators are processed via explicit steps, while the set-valued operators are computed by their resolvents. Numerical experiments on constrained image denoising problems are presented to show the performance of the proposed algorithms

Primal-Dual Splitting Algorithms for Solving Structured Monotone Inclusion with Applications

This work proposes two different primal-dual splitting algorithms for solving structured monotone inclusion containing a cocoercive operator and the parallel-sum of maximally monotone operators. In particular, the parallel-sum is symmetry. The proposed primal-dual splitting algorithms are derived from two approaches: One is the preconditioned forward–backward splitting algorithm, and the other is the forward–backward–half-forward splitting algorithm. Both algorithms have a simple calculation framework. In particular, the single-valued operators are processed via explicit steps, while the set-valued operators are computed by their resolvents. Numerical experiments on constrained image denoising problems are presented to show the performance of the proposed algorithms