ABSTRACT
@#Abstract: Objective To compare the mosquito trapping effect of BG-trap mosquito trap using carbon dioxide versus BG-lure attractant under filed conditions. Methods In August and September 2020, two areas were set with a distance of 100 m. Two sites were set at each area, and one mosquito trap BG trap was set with a distance of 5 m. Each site was set with different flow of CO2 and different amount of BG-lure attractants. The BG-trap mosquito traps on the same area would exchange positions every other day. The mosquitoes captured by each mosquito trap was collected and classified. and the species, sex and number of mosquitoes captured were recorded and counted. Results The densities of Aedes albopictus captured by BG+/CO2-and BG-/CO2+were 14 and 31, and that of Culex pipiens pallens were 2 and 16, respectively. The differences were statistically significant (Aedes albopictus, t=-2.675, P<0.05; Culex pipiens pallens, t=-4.873, P<0.05). With BG-lure attractant, the females of Aedes albopictus and Culex pipiens pallens in the CO2+group were 2.6 (25/9.5) and 12.0 (12 /1) times higher than those in the CO2-group, and the differences were statistically significant (female Aedes albopictus, t=-4.119, P<0.01; female Culex pipiens pallens, t=-4.592, P<0.01), suggesting that the most important attractant to female mosquitoes is CO2. With BG-lure attractant, the male Aedes albopictus in the CO2+ group was 3.0 (12/4) times higher than that in the CO2-group, and the difference was statistically significant (male Aedes albopictus, t=-3.284, P<0.01). Without BG-lure attractant, female Aedes albopictus and female Culex pipiens pallens in the CO2 + group were 1.8 (18 / 10) and 15.5 (15.5/1.0) times higher than those in the CO2-group, and the difference was statistically significant (female Aedes albopictus, t=-2.868, P<0.05; female Culex pipiens pallens, t=-5.259, P<0.05). Without BG-lure attractant, the male Aedes albopictus in the CO2+group was 2.0 (9.0/4.5) times higher than that in the CO2-group, with a statistically significant difference (t=-2.508, P<0.05). With CO2, Aedes albopictus and Culex pipiens pallens in the BG + attractant group were 1.4 (43.5/31) and 0.78 (12.5/16.0) times higher than those in the BG-attractant group, and the differences were not statistically significant (Aedes albopictus, t=-0.943, P>0.05 ; Culex pipiens pallens, t=0.709, P>0.05). Without CO2, Aedes albopictus and Culex pipiens pallens in the BG + attractant group were 1.0 (14/14) and 2.0 (2.0/1.0) times higher than those in the BG + attractant group, and the differences were not statistically significant (Aedes albopictus, t=-0.500, P>0.05; Culex pipiens pallens, t=-1.000, P>0.05). Without BG-lure attractant, the densities of female Aedes albopictus captured by adding 0, 1 and 2 parts of dry ice were 10, 17.5 and 18 respectively, and the difference was statistically significant among the three groups (F=3.942, P<0.05). The densities of female Culex pipiens pallens captured were 1, 13 and 18 respectively, and the difference was statistically significant among the three groups (F=13.881, P<0.05). However, there was no significant difference between the capture of female Aedes albopictus and female Culex pipiens pallens by adding 1 part of dry ice and 2 parts of dry ice (female Aedes albopictus, t=0.112, P>0.05; female Culex pipiens pallens, t=-0.540, P>0.05). Without CO2, 10, 10, 9.5 and 1, 1 and 1.5 female Aedes albopictus and Culex pipiens pallens were captured by adding 0, 1 and 2 portions of BG-lure attractants, respectively. There were no significant differences between the three groups (female Aedes albopictus, F=0.120, P>0.05; female Culex pipiens pallens, F=0.477, P>0.05). Conclusions In the monitoring of BG-trap mosquito trap, the mosquito trapping effect of CO2 is better than that of BG-lure attractant. When the same monitoring effect is obtained, the use of CO2 (100 mL/min) can save the use cost.
ABSTRACT
OBJECTIVES: Recent guidelines recommend that all cirrhotic patients should undergo endoscopic screening for esophageal varices. That identifying cirrhotic patients with esophageal varices by noninvasive predictors would allow for the restriction of the performance of endoscopy to patients with a high risk of having varices. This study aimed to develop a decision model based on classification and regression tree analysis for the prediction of large esophageal varices in cirrhotic patients. METHODS: 309 cirrhotic patients (training sample, 187 patients; test sample 122 patients) were included. Within the training sample, the classification and regression tree analysis was used to identify predictors and prediction model of large esophageal varices. The prediction model was then further evaluated in the test sample and different Child-Pugh classes. RESULTS: The prevalence of large esophageal varices in cirrhotic patients was 50.8 percent. A tree model that was consisted of spleen width, portal vein diameter and prothrombin time was developed by classification and regression tree analysis achieved a diagnostic accuracy of 84 percent for prediction of large esophageal varices. When reconstructed into two groups, the rate of varices was 83.2 percent for high-risk group and 15.2 percent for low-risk group. Accuracy of the tree model was maintained in the test sample and different Child-Pugh classes. CONCLUSIONS: A decision tree model that consists of spleen width, portal vein diameter and prothrombin time may be useful for prediction of large esophageal varices in cirrhotic patients.