Interference of volunteer corn on soybean grown under cerrado conditions.

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Geometric and material nonlinear analysis of imperfect circular hollow section (CHS) columns : steeel tubes and concrete filled tubes

The comparison between theoretical predictions and design curve predictions of the critical stresses, for a wide range of slenderness ratio, is valid and useful. For columns made of steel S235 with initial deformations and slenderness below about 60, columns capacity is controlled by elastic-plastic resistant and performance, as the slenderness decreases (until the minimum limit, controlled by crushing or plastic squash). For columns with slenderness above 60, columns capacity tends to be controlled by elastic instability as slenderness increases. For the used steel S235, in the dimensionless plot of critical stress divided by steel yield stress versus slenderness, the parametric effect of the end-eccentricities is only slightly significant for slenderness between 40 to 80. Rankine-Gordon formula provides conservative safe estimates of the resistant column capacity. The results of the tests of composite columns reveal some of the strength advantage of using composite construction over traditional steel constructions. They also show the importance of top end eccentricities in the results, and the need to ascertain their value with accuracy of about 1-2 mm. Some resistant capacity gains as well as some ductility reductions, are given in tabular form; reasons for possible discrepancy of results are mentioned. The interaction equation for circular section tubes is introduced, and the Merchant-Rankine formula (and its modification) is justified through an example

Procedimento prático para elaboração de uma tabela de produção.

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Dorsal root ganglion macrophages contribute to both the initiation and persistence of neuropathic pain.

Paralleling the activation of dorsal horn microglia after peripheral nerve injury is a significant expansion and proliferation of macrophages around injured sensory neurons in dorsal root ganglia (DRG). Here we demonstrate a critical contribution of DRG macrophages, but not those at the nerve injury site, to both the initiation and maintenance of the mechanical hypersensitivity that characterizes the neuropathic pain phenotype. In contrast to the reported sexual dimorphism in the microglial contribution to neuropathic pain, depletion of DRG macrophages reduces nerve injury-induced mechanical hypersensitivity and expansion of DRG macrophages in both male and female mice. However, fewer macrophages are induced in the female mice and deletion of colony-stimulating factor 1 from sensory neurons, which prevents nerve injury-induced microglial activation and proliferation, only reduces macrophage expansion in male mice. Finally, we demonstrate molecular cross-talk between axotomized sensory neurons and macrophages, revealing potential peripheral DRG targets for neuropathic pain management

Enhanced propagation of motile bacteria on surfaces due to forward scattering

How motile bacteria move near a surface is a problem of fundamental biophysical interest and is key to the emergence of several phenomena of biological, ecological and medical relevance, including biofilm formation. Solid boundaries can strongly influence a cell's propulsion mechanism, thus leading many flagellated bacteria to describe long circular trajectories stably entrapped by the surface. Experimental studies on near-surface bacterial motility have, however, neglected the fact that real environments have typical microstructures varying on the scale of the cells' motion. Here, we show that micro-obstacles influence the propagation of peritrichously flagellated bacteria on a flat surface in a non-monotonic way. Instead of hindering it, an optimal, relatively low obstacle density can significantly enhance cells' propagation on surfaces due to individual forward-scattering events. This finding provides insight on the emerging dynamics of chiral active matter in complex environments and inspires possible routes to control microbial ecology in natural habitats

Superconductivity from spin fluctuations and long-range interactions in magic-angle twisted bilayer graphene

Magic-angle twisted bilayer graphene (MATBG) has been extensively explored both theoretically and experimentally as a suitable platform for a rich and tunable phase diagram that includes ferromagnetism, charge order, broken symmetries, and unconventional superconductivity. In this work, we investigate the intricate interplay between long-range electron-electron interactions, spin fluctuations, and superconductivity in MATBG. By employing a low-energy model for MATBG that captures the correct shape of the flat bands, we explore the effects of short- and long-range interactions on spin fluctuations and their impact on the superconducting (SC) pairing vertex in the Random Phase Approximation (RPA). We find that the SC state is notably influenced by the strength of long-range Coulomb interactions. Interestingly, our RPA calculations indicate that there is a regime where the system can traverse from a magnetic phase to the SC phase by \emph{increasing} the relative strength of long-range interactions compared to the on-site ones. These findings underscore the relevance of electron-electron interactions in shaping the intriguing properties of MATBG and offer a pathway for designing and controlling its SC phase.Comment: 9 pages, 5 figure