We compute loop corrections to the effective action of a field theory on a fivedimensional S 1 /Z 2 orbifold. We find that the quantum loop effects of interactions in the bulk produce infinite contributions that require renormalization by fourdimensional couplings on the orbifold fixed planes. Thus bulk couplings give rise to renormalization group running of brane couplings.

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We note that orbifold boundary conditions that produce chiral fermion zero modes in compactified higher dimensional theories may distort scalar field vacuum expectation values, giving rise to nontrivial dependence on the extra dimensions. We illustrate this in a simple five-dimensional model, which has chiral fermion zero modes stuck to fat branes. The model could provide a simple and explicit realization of the separation of quarks and leptons in the fifth dimension. We discuss the Kaluza-Klein expansion in some detail. We find that there are, in general, non-zero-mode states stuck to the brane, just as the chiral zero mode is. We see explicitly the transition from the states dominated by the internal structure of the fat brane to those dominated by the compactification.

We show that brane inflation is very sensitive to tiny sharp features in extra dimensions, including those in the potential and in the warp factor. This can show up as observational signatures in the power spectrum and/or non-Gaussianities of the cosmic microwave background radiation (CMBR). One general example of such sharp features is a succession of small steps in a warped throat, caused by Seiberg duality cascade using gauge/gravity duality. We study the cosmological observational consequences of these steps in brane inflation. Since the steps come in a series, the prediction of other steps and their properties can be tested by future data and analysis. It is also possible that the steps are too close to be resolved in the power spectrum, in which case they may show up only in the non-Gaussianity of the CMB temperature fluctuations and/or EE polarization. We study two cases. In the slow-roll scenario where steps appear in the inflaton potential, the sensitivity of brane inflation to the height and width of the steps is increased by several orders of magnitude comparing to that in previously studied large field models. In the IR DBI scenario where steps appear in the warp factor, we find that the glitches in the power spectrum caused by these sharp features are generally small or even unobservable, but associated distinctive non-Gaussianity can be large. Together with its large negative running of the power spectrum index, this scenario clearly illustrates how rich and different a brane inflationary scenario can be when compared to generic slow-roll inflation. Such distinctive stringy features may provide a powerful probe of superstring theory.

Core Ideas Recommending complex maize pest management options for small‐scale African farmers. Determining effective and environmentally friendly fall armyworm management for smallholder farmers. Evaluating effects of edible legume and maize intercropping on fall armyworm. Maize (Zea mays L.) production in Africa is constrained by several biotic and abiotic factors. The recent occurrence of fall armyworm (FAW), Spodoptera frugiperda (JE Smith) a new invasive pest in Africa, has escalated the problem. Push–pull technology (PPT), proven to be effective for stemborers (Chilo partellus Swinhoe and Busseola fusca Fuller) and the parasitic weed striga (Striga hermontica Delile) management in Africa has been shown to provide good control of FAW. This study investigated if intercropping maize with edible legumes can also reduce the abundance of FAW. Six treatments including (i) climate‐smart PPT, (ii) conventional PPT, (iii) maize intercropped with bean (Phaseolus vulgaris L.), (iv) maize intercropped with soybean [Glycine max (L.) Merr.], (v) maize intercropped with groundnut [Vigna unguiculata (L.) Walp.] and, (vi) mono‐cropped maize were evaluated on farm in six districts of Uganda in the 2017 short rains season. Data collected included FAW, stemborer, and striga infestation symptoms, and severity of infestation. Climate‐smart PPT performed best in reducing stemborer, FAW, and striga infestation followed by conventional PPT over all the phenological stages of maize. Intercropping of maize with leguminous crops also provided significant reduction of stemborer and FAW compared to mono‐cropped maize, especially in the early growth phases of the maize up to tasseling. However, intercropping of maize with edible legumes was not very effective for striga management as compared to PPT. Hence in addition to PPT, intercropping of maize with edible legumes could also be an alternative FAW management option when integrated with other sustainable management measures.