Biostimulants are materials that when applied in small amounts are capable of promoting plant growth. Nanoparticles (NPs) and nanomaterials (NMs) can be considered as biostimulants since, in specific ranges of concentration, generally in small levels, they increase plant growth. Pristine NPs and NMs have a high density of surface charges capable of unspecific interactions with the surface charges of the cell walls and membranes of plant cells. In the same way, functionalized NPs and NMs, and the NPs and NMs with a corona formed after the exposition to natural fluids such as water, soil solution, or the interior of organisms, present a high density of surface charges that interact with specific charged groups in cell surfaces. The magnitude of the interaction will depend on the materials adhered to the corona, but high-density charges located in a small volume cause an intense interaction capable of disturbing the density of surface charges of cell walls and membranes. The electrostatic disturbance can have an impact on the electrical potentials of the outer and inner surfaces, as well as on the transmembrane electrical potential, modifying the activity of the integral proteins of the membranes. The extension of the cellular response can range from biostimulation to cell death and will depend on the concentration, size, and the characteristics of the corona.

In this article, we propose a robust hierarchical inverse dynamics control scheme for redundant manipulators, which guarantees both predefined-time convergence of regulation tasks and robustness against model uncertainties/disturbances. Predefined-time convergence of a robotic task means that the task error is regulated to the origin at a desired preset time, independently of the initial state of the robot. The strict hierarchy of tasks is ensured by the so-called dynamic consistency, which avoids conflicts between decoupled task constraints. Thus, it enables the robot with more dexterity for reaching targets in its workspace while overcoming obstacles and joint limits. Predefined-time convergence facilitates the design of a time schedule to execute sequential and simultaneous tasks. All these features are supported by a stability analysis and experiments with two torque-controlled mobile manipulators in pick-and-place applications.

The production of ornamentals is an economic activity of great interest, particularly the production of Lilium. This plant is very attractive for its color and shapes; however, the quality of its flower and its shelf life can decrease very fast. Therefore, it is of the utmost importance to develop techniques that allow for increasing both flower quality and shelf life. Nanotechnology has allowed for the use of various materials with unique characteristics. These materials can induce a series of positive responses in plants, among which the production of antioxidant compounds stands out. The objective of this study was to determine the impact of the application of silicone nanoparticles (SiO₂ NPs) on the quality, shelf life, and antioxidant status of Lilium. For this, different concentrations of SiO₂ NPs (0, 200, 400, 600, 800, and 1000 mg L⁻¹) were applied in two ways, foliar and soil, as two independent experiments. The contents of enzymatic (superoxide dismutase, glutathione peroxidase, catalase, ascorbate peroxidase, and phenylalanine ammonia lyase) and non-enzymatic (phenols, flavonoids, and glutathione) antioxidant compounds, the mineral content, flower quality, and shelf life were analyzed. The results showed that the application of SiO₂ NPs through the foliar method induced a greater flowers’ shelf life (up to 21.62% more than the control); greater contents of Mg, P, and S (up to 25.6%, 69.1%, and 113.9%, respectively, compared to the control); more photosynthetic pigment (up to 65.17% of total chlorophyll); more glutathione peroxidase activity (up to 69.9%); more phenols (up to 25.93%); and greater antioxidant capacity as evaluated by the DPPH method (up to 5.18%). The use of SiO₂ NPs in the production of Lilium is a good alternative method to increase flower quality and shelf life.

This work presents a merging strategy for cooperative vehicles. In the proposed strategy, each vehicle possesses a tracking controller that considerers both tracking and coupling error signals, where all vehicles in the group know their positions. The trajectories of the cooperative vehicles are developed, to guarantee that each vehicle keeps a certain distance from the rest of the vehicles in the group, and are designed by using the virtual structure approach. The merging strategy is successfully validated in an experimental setup consisting of a group of nonholonomic mobile vehicles that represents the simplest bicycle model for cars with a zero vehicle length. It is shown using Lyapunov theory that this strategy is global asymptotically stable for the group.

UV-A radiation is a tool that has a stimulant action in plants and can be used to induce benefits through the production of bioactive compounds and the synthesis of secondary metabolites, among others. Particularly, its application could stimulate tolerance to the biotic stress caused by Fusarium oxysporum f. sp. lycopersici (Fol) in tomato plants; for this reason, the aim of the present study was to evaluate the ability of UV-A radiation to stimulate tolerance against Fol. For this, a tomato crop was established in which two conditions of supplementation with UV-A radiation were tested on plants inoculated with the fungus Fol. The pathogen’s impact on the agronomic parameters, its incidence and severity, and the contents of stress biomarkers, secondary metabolites and photosynthetic pigments were determined. The results show that the impact of the pathogen on severity was about 60%; therefore, the impact on fruit yield was also negative (−31%). Moreover, the pathogen significantly impacted the content of stress biomarkers, and the positive control increased H₂O₂ (+23.9%), malondialdehyde (+41.7%) and proline (+54.8%). In contrast, UV-A radiation significantly decreased Fol severity (−35.5%), and prevented its negative effect on the tomato plant/fruit yield. In addition, the application of UV-A radiation decreased the contents of stress biomarkers (−10.4% O₂^•−, −22% H₂O₂, and −16% MDA), and increased the contents of secondary metabolites (+13.2% flavonoids, +35% anthocyanins) and photosynthetic pigments (+17% β-carotene, +12% yellow pigments, and +19.8% total chlorophyll) in the plants inoculated with the pathogen. From the results obtained, it can be concluded that the application of UV-A radiation is a good alternative means to control the attack of pathogens such as Fol on tomato plants, without adverse consequences for the environment or the crop.

The control of micronutrient application in cucumber cultivation has great importance as they participate in many functions of metabolism. In addition, micronutrient application efficiency is fundamental to avoid periods of overconsumption or deficits in the crop. To determine micronutrient accumulation using a dynamic model, two cycles of Vitaly and Luxell cucumber crops were grown. During the development of the crop, micronutrient content (Fe, B, Mn, Cu, and Zn) in the different organs of the cucumber plant was quantified. The model dynamically simulated the accumulation of biomass and micronutrients using climatic variables recorded inside the greenhouse as inputs. It was found that a decrease in photosynthetically active radiation and temperature significantly diminished the accumulation of biomass by the cucumber plants. On the other hand, the results demonstrated that the model efficiently simulated both the accumulation of biomass and micronutrients in a cucumber crop. The efficiency evaluation showed values higher than R² > 0.95. This dynamic model can be useful to define adequate strategies for the management of cucumber cultivation in greenhouses as well as the application of micronutrients.