Transgenic maize engineered to express insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) has become widely adopted in U.S. agriculture. In 2009, Bt maize was planted on more than ...22.2 million hectares, constituting 63% of the U.S. crop. Using statistical analysis of per capita growth rate estimates, we found that areawide suppression of the primary pest Ostrinia nubilalis (European corn borer) is associated with Bt maize use. Cumulative benefits over 14 years are an estimated $3.2 billion for maize growers in Illinois, Minnesota, and Wisconsin, with more than $2.4 billion of this total accruing to non-Bt maize growers. Comparable estimates for Iowa and Nebraska are $3.6 billion in total, with $1.9 billion for non-Bt maize growers. These results affirm theoretical predictions of pest population suppression and highlight economic incentives for growers to maintain non-Bt maize refugia for sustainable insect resistance management.
For the first time, we present an electro-optic slot waveguide phase modulator on the InP membrane on Silicon (IMOS) platform. Low-frequency characterization of this modulator shows that it can ...achieve a <inline-formula> <tex-math notation="LaTeX"> {V}_{ {\pi }} {L}_{ {\pi }} </tex-math></inline-formula> product as low as 4.5 V.mm and an extinction ratio equal to 10.6 dB. The 3-dB optical bandwidth of this modulator is measured to be 10.5 GHz. Here, working principles, design, fabrication, measurements, analysis of the electrical and electro-optic performance and prospects of this modulator are presented.
An amphiphilic photoisomerizable macrocycle has been prepared that forms stable Langmuir monolayers at the air−water interface. The hydrophilic core of the molecule switches between closed and open ...isomers upon irradiation by the appropriate wavelengths of light. Isotherm measurements, Brewster angle microscope images, and atomic force micrographs (of transferred Langmuir−Blodgett films) suggest a phase transition between a face-on to a tilted edge-on molecular orientation as a function of surface concentration. In the face-on phase, in situ photoisomerization results in a reversible increase in surface pressure due to greater molecular crowding in the open configuration.
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