[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.

[Investigation on the risk factors for reported rising of measles incidence during November, 2011 to February, 2012, in some areas of Hubei province].

OBJECTIVE: To identify the risk factors for reported sudden rise of measles incidence in November, 2011, in some areas of Hubei province. METHODS: We analyzed all measles patients reported in the measles surveillance system from November 2011 to February 2012 in two prefectures with highest attack rates and their vaccination history by reviewing vaccination records. We interviewed patients' parents by telephone to obtain the history of visiting health care within 7 to 21 days before onset. We also used case-crossover study to estimate the relative risk (RR) of hospital acquired infection and to compare the exposure to health care between 7-21 days before onset to 37-51 days before onset among measles patients. RESULTS: Totally 140 patients were reported in the two prefectures. Reported measles incidence rates among the population aged <8 m(69/100 000) and 8 m to 17 m (72/100 000) were higher than other age groups (rang from 0 to 5.8 per 100 000). Among the population aged 8 m to 17 m, estimated vaccination coverage was lower than 75%, and it was lower than 90% among those aged 18 m to 3 yrs. During 7-21 days before onset, 58% (29/50) of the patients had an exposure to health care settings, compared to 14% (7/50) of patients during 37 to 51 days before onset (MH RR = 5.4, 95% confidence interval = 2.1-14.0). CONCLUSION: Under the condition of measles vaccination coverage lower than 95%, iatrogenic infection was a risk factor for measles in Hubei.

Effect of conjugated linoleic acid on Cyprinus carpio var. Jian regarding growth, immunity, and disease resistance to Aeromonas hydrophila.

The present study was performed to investigate the effect of dietary conjugated linoleic acid (CLA) on the growth performance, immune parameters and disease resistance to Aeromonas hydrophila of juvenile Jian carp. A total of 900 juvenile Jian carp (10.71 +/- 0.02 g) were randomly allocated into six groups of each three replicates, feeding isonitrogenous (35% crude protein) and isolipidic (7.8% crude fat) diets containing graded amounts of CLA (0, 0.5, 0.8, 1.4, 1.7, and 2.0%) for 60 days. After a 60-day growth test, a challenge trial was conducted by intraperitoneal injection of Aeromonas hydrophila to determine the effect of CLA on disease resistance of juvenile Jian carp. The results showed that diets incorporated with a proportion of up to 2.0% CLA without effect on weight gain, feed intake, and feed conversion ratio, but improved immune parameters and disease resistance of juvenile Jian carp. The dietary CLA level of optimal disease resistance to Aeromonas hydrophila was estimated to be 1.7% in juvenile Jian carp using broken-line analysis.