In this paper, we study the forced oscillation of the higher-order nonlinear difference equation of the formwhere m ≥ 1, τ , σ 1 and σ 2 are integers, 0 < α < 1 < β are constants, * (u) = |u| *-1 u, p(n), q 1 (n), q 2 (n) and f (n) are real sequences with p(n) > 0. By taking all possible values of τ , σ 1 and σ 2 into consideration, we establish some new oscillation criteria for the above equation in two cases: (i) q 1 = q 1 (n) ≤ 0, q 2 = q 2 (n) > 0; (ii) q 1 ≥ 0, q 2 < 0. MSC: 39A10

Previous studies investigating the association between glutathione S-transferase M1 (GSTM1) null genotype and laryngeal cancer risk reported controversial results. Thus, a meta-analysis was performed to clarify the effect of GSTM1 null genotype on laryngeal cancer risk. A literature search was performed for all possible studies. We estimated summary odd ratio (OR) with its 95 % confidence interval (95 % CI) to assess the association. Subgroup analyses were performed by ethnicity or the sample size. 24 individual case-control studies involving a total of 2,809 laryngeal cancer cases and 4,478 controls were finally included into this meta-analysis. Meta-analyses of total 24 studies showed the GSTM1 null genotype was significantly associated with increased laryngeal cancer risk (random-effects OR = 1.44, 95 % CI 1.19-1.73, P < 0.001). Subgroup analyses by ethnicity showed that the GSTM1 null genotype was associated with increased laryngeal cancer risk in both Caucasians (fixed-effects OR = 1.17, 95 % CI 1.04-1.33, P = 0.012) and Asians (random-effects OR = 1.89, 95 % CI 1.28-2.77, P = 0.001). Also, subgroup analyses by sample size also further identified this association above. The cumulative meta-analyses showed a trend of more obvious association between GSTM1 null genotype and increased risk of laryngeal cancer as information accumulated by year. Meta-analysis of available data suggests that GSTM1 null genotype contributes to increased laryngeal cancer risk in both Caucasians and East Asians.

In order to realize the reproduction and simulation of urban rainstorm and waterlogging scenarios with complex underlying surfaces. Based on the Mike series models, we constructed an urban storm-flood coupling model considering one-dimensional river channels, two-dimensional ground and underground pipe networks. Luoyang City was used as a pilot to realize the construction of a one-dimensional and two-dimensional coupled urban flood model and flood simulation. where is located in the western part of Henan Province, China. The coupled model was calibrated and verified by the submerged water depths of 16 survey points in two historical storms flood events. The average relative error of the calibration simulated water depth was 22.65%, and the average absolute error was 13.93cm; the average relative error of the verified simulated water depth was 15.27%, The average absolute error is 7.54cm, and the simulation result is good. Finally, 28 rains with different return periods and different durations were designed to simulate and analyze the rainstorm inundation in the downtown area of Luoyang. The result shows that the R2 of rainfall and urban rainstorm inundation is 0.8776, and the R2 of rainfall duration and urban rainstorm inundation is 0.8141. Therefore, rainfall is the decisive factor in the formation of urban waterlogging disasters, which is actually the rainfall duration. The study results have important practical significance for urban flood prevention, disaster reduction and traffic emergency management.

No abstract

In order to realize the reproduction and simulation of urban rainstorm and waterlogging scenarios with complex underlying surfaces. Based on the Mike series models, we constructed an urban storm-flood coupling model considering one-dimensional river channels, two-dimensional ground and underground pipe networks. Luoyang City was used as a pilot to realize the construction of a one-dimensional and two-dimensional coupled urban flood model and flood simulation. where is located in the western part of Henan Province, China. The coupled model was calibrated and verified by the submerged water depths of 16 survey points in two historical storms flood events. The average relative error of the calibration simulated water depth was 22.65%, and the average absolute error was 13.93cm; the average relative error of the verified simulated water depth was 15.27%, The average absolute error is 7.54cm, and the simulation result is good. Finally, 28 rains with different return periods and different durations were designed to simulate and analyze the rainstorm inundation in the downtown area of Luoyang. The result shows that the R2 of rainfall and urban rainstorm inundation is 0.8776, and the R2 of rainfall duration and urban rainstorm inundation is 0.8141. Therefore, rainfall is the decisive factor in the formation of urban waterlogging disasters, which is actually the rainfall duration. The study results have important practical significance for urban flood prevention, disaster reduction and traffic emergency management.