A new multilayer nonhydrostatic formulation for surface water waves

This work presents a new multilayer nonhydrostatic formulation for surface water waves. The new governing equations define velocities and pressure at an arbitrary location of a vertical layer and only contain spatial derivatives of maximum second order. Stoke-type Fourier and shoaling analyses are carried out to scrutinize the mathematical properties of the new formulation, subsequently optimizing the representative interface and the location to define variables in each layer to improve model accuracy. Following the analysis, the one-layer model exhibits accurate linear and nonlinear characteristics up to kd = I, demonstrating similar solution accuracy to the existing second-order Boussinesq-type models. The two-layer model with optimized coefficients can maintain its linear and nonlinear accuracy up to kd = 4I, which boasts of better solution accuracy a larger application range than most existing fourth-order Boussinesq model and two-layer Boussinesq models. The three-layer model presents accurate linear and nonlinear characteristics up to kd = 10Ï, effectively removing any shallow water limitation. The current multilayer nonhydrostatic water wave model does not predefine the vertical flow structures, and more accurate vertical velocity distributions can be obtained by considering the velocity profiles in coefficient optimization

DataSheet1_The role of tetradecane in the identification of host plants by the mirid bugs Apolygus lucorum and Adelphocoris suturalis and potential application in pest management.xlsx

The mirid bugs Apolygus lucorum and Adelphocoris suturalis are considered serious pests of many crops in China, the host plant recognition of these pests remains unclear. The current study investigated the vital odor cues of two mirid bugs and evaluated the role of olfactory recognition in host recognition. The GC-EAD response of mirid bugs to volatiles of their host plant Phaseolus vulgaris was tested. Tetradecane, 2-propyl-1-pentanol, and dodecanal elicited strong EAG responses by mirid bugs and were tested with field experiments. The results indicated tetradecane was significantly more attractive than other attractants, yielding 30.33 ± 2.19 mirid bugs trapped during 7 days. The selected response rates to tetradecane were above 60%, which was most attractive to female A. lucorum at 1.5 mg/ml. Among seven tetradecane derivatives, tetradecane and tetradecanoic acid were the most potent attractants to A. lucorum and A. suturalis. Tetradecane was present in the volatiles of 10 common hosts, and their difference in relative content was significant. The presence of tetradecane seemed relevant to the olfactory response intensity of two mirid bugs towards the different host plants. The artificial supplement of tetradecane increased the attractive effect of host plants. These results suggested that tetradecane plays a vital role in the olfactory selection by two mirid bugs, and it can be made into field baits as a novel ecological strategy to manage these pests with widely reported pesticide resistance. However, results suggested host recognition is not entirely dependent on odor cues. We demonstrated that A. suturalis and A. lucorum adults have similar olfactory recognition mechanisms to their hosts in long-distance host selection. While, the differences in host plant selection between the two pests should occur in close range due to differences in gustatory or tactile sensory organs of A. lucorum and A. suturalis.</p

Pink bollworm abundance on non-Bt cotton before and after adoption of Bt cotton.

<p>Before Bt cotton (1995–1999), annual average abundance did not change significantly for eggs (slope = −0.0048, df = 3, <i>R</i>² = 0.004, <i>P</i>  = 0.92) and larvae (slope = −0.027, df = 3, <i>R²</i> = 0.64, <i>P</i>  = 0.10). With Bt cotton (2000–2010), annual average abundance declined significantly for both eggs (slope = −0.070, df = 9, <i>R</i>² = 0.86, <i>P</i><0.0001) and larvae (slope = −0.083, df = 9, <i>R</i>² = 0.80, <i>P</i>  = 0.0002).</p

Stepwise regression testing association of Bt cotton (%), temperature, and rainfall with population density of pink bollworm.

<p>Stepwise regression testing association of Bt cotton (%), temperature, and rainfall with population density of pink bollworm.</p

Sites for pink bollworm monitoring in China’s Yangtze River Valley.

<p>Sites for pink bollworm monitoring in China’s Yangtze River Valley.</p

Percentage of cotton hectares planted with Bt cotton in the Yangtze River Valley, 1999 to 2010.

<p>Percentage of cotton hectares planted with Bt cotton in the Yangtze River Valley, 1999 to 2010.</p

Diminishing Returns from Increased Percent Bt Cotton: The Case of Pink Bollworm

<div><p>Regional suppression of pests by transgenic crops producing insecticidal proteins from <i>Bacillus thuringiensis</i> (Bt) has been reported in several cropping systems, but little is known about the functional relationship between the ultimate pest population density and the pervasiveness of Bt crops. Here we address this issue by analyzing 16 years of field data on pink bollworm (<i>Pectinophora gossypiella</i>) population density and percentage of Bt cotton in the Yangtze River Valley of China. In this region, the percentage of cotton hectares planted with Bt cotton increased from 9% in 2000 to 94% in 2009 and 2010. We find that as the percent Bt cotton increased over the years, the cross-year growth rate of pink bollworm from the last generation of one year to the first generation of the next year decreased. However, as the percent Bt cotton increased, the within-year growth rate of pink bollworm from the first to last generation of the same year increased, with a slope approximately opposite to that of the cross-year rates. As a result, we did not find a statistically significant decline in the annual growth rate of pink bollworm as the percent Bt cotton increased over time. Consistent with the data, our modeling analyses predict that the regional average density of pink bollworm declines as the percent Bt cotton increases, but the higher the percent Bt cotton, the slower the decline in pest density. Specifically, we find that 95% Bt cotton is predicted to cause only 3% more reduction in larval density than 80% Bt cotton. The results here suggest that density dependence can act against the decline in pest density and diminish the net effects of Bt cotton on suppression of pink bollworm in the study region. The findings call for more studies of the interactions between pest density-dependence and Bt crops.</p></div

Within-year density dependence from G1 to G3.

<p>The per-capita pink bollworm growth rate from the first to the last generation within the same year, ln(E3/E1) or ln(L3/L1), declined significantly as the log of density increases, (<b>A</b>) for eggs (slope = −0.38, df = 14, R² = 0.68, P = 0.0001) and (<b>B</b>) for larvae (slope = −0.32, df = 14, R² = 0.51, P = 0.002).</p

Population abundance of pink bollworm on non-Bt cotton and the percent Bt cotton planting area in the Yangtze River Valley.

<p>(<b>A</b>) Average number of pink bollworm eggs per 100 plants in the first, second and third generation (indicated by E1, E2 and E3 respectively and plotted on y-axis to the left) and percent Bt cotton (plotted on y-axis to the right). (<b>B</b>) Average number of pink bollworm larvae per 100 plants in the first, second and third generation (indicated by L1, L2 and L3 respectively).</p

Cross-year growth rates of pink bollworm versus percent Bt cotton.

<p>(<b>A</b>) Eggs: Cross-year growth rate from last generation of the present year to the first generation of next year, ln(E1′/E3), versus Bt cotton %. Regression shows that ln(E1′/E3) decreases linearly as percentage of Bt cotton increases (slope = −0.012, df = 13, R² = 0.68, P = 0.0002). (<b>B</b>) Larvae: Cross-year growth rate ln(L3/L1) versus Bt cotton %. Regression shows that ln(L3/L1) decreases linearly as percent Bt cotton increases (slope = −0.013, df = 13, R² = 0.70, P = 0.0001).</p