State University of Northern Rio de Janeiro

Introduction Polycyclic aromatic hydrocarbons (PAHs), a class of petroleum-derived compounds known for causing cellular damage and for their recalcitrant behavior, severely limit effective biodegradation. Arbuscular mycorrhizal fungi (AMF) from oil-contaminated environments can mitigate PAH-related stress on host plants, highlighting the bioremediation potential of associations between native AMF and local plant species.Objectives This study aimed to evaluate the role of native AMF-plant associations in the bioremediation of petroleum-contaminated dune sand, using Ipomoea pes-caprae as a model pioneer species. To this end, a native AMF inoculum derived from sandbars of the Restinga de Jurubatiba National Park, southeastern Brazil, was applied in a controlled experiment simulating an oil spill.Methods The inoculum, propagated in trap pots, consisted of three dominant sporocarpic Glomus species native to the study area. Ipomoea pes-caprae cuttings were rooted in vitro and transplanted into sterilized sandbar sediment. To simulate an oil spill, 8 g of petroleum were applied to each pot, with or without bioaugmentation (sediment + plant + AMF + oil [SPFO] and sediment + plant + oil treatments), over 48 days. Residual hydrocarbons were compared with a natural attenuation control (sediment + oil).Results The bioaugmented treatment (SPFO) showed reductions in hydrocarbon concentrations, with 34.8% terpane degradation and 45.4% PAH degradation. PAH accumulation within intraroot fungal structures was confirmed through fluorescence microscopy and image analysis.Conclusion This study demonstrates that AMF enhance the performance of I. pes-caprae under petroleum contamination, strengthening plant-fungus interactions in coastal dunes. Native AMF improved early stabilization and supported the plant's capacity to cope with hydrocarbon stress, confirming their ecological relevance for restoring oil-affected coastal systems.

This study presents an application of Physics-Informed Neural Networks (PINNs) and Galerkin Physics-Informed Neural Networks (G-PINNs) to the modeling of tracer dispersion in porous media using experimental data from sodium chloride transport in Berea sandstone cores. The proposed framework considers Dirichlet and Neumann boundary conditions in a 1D cylindrical coordinate system and employs artificial neural networks as basis functions in the G-PINN formulation to improve numerical accuracy. Both methodologies are trained to satisfy the underlying advection-diffusion equation while fitting the available experimental measurements. The study includes direct and inverse problem applications, with particular emphasis on estimating the effective tracer dispersion coefficient from outlet concentration data. To improve convergence in the inverse problem, a modified optimization strategy combining a scaled L-BFGS scheme and a reduced number of Adam iterations is introduced. The results show that both PINN and G-PINN can reproduce the concentration evolution with good agreement, while the proposed scaled L-BFGS + Adam strategy significantly reduces computational time compared with using Adam alone. These findings highlight the potential of PINN-based and Galerkin-based neural formulations for experimental-data-driven modeling and parameter estimation in porous media transport problems, with applications in reservoir engineering, contaminant transport, and related subsurface flow systems.

The present study evaluated the effects of increasing levels of sweeping cassava flour (SCF) on the chemical composition, in vitro degradability, fermentation parameters, microbial populations, and aerobic stability of sugarcane top silage. The experiment was carried out in a completely randomized design with four treatments (0, 5, 10, and 15% SCF on an as-fed basis) and four replicates. Contents of dry matter, organic matter, crude protein, crude fiber, and ash showed quadratic responses (p < 0.05), while most other variables presented linear behavior (p < 0.05). Lignin and in vitro neutral detergent fiber degradability were not influenced (p > 0.05). Regarding fermentation, lactic and acetic acid concentrations decreased (p < 0.05) with SCF inclusion, although with different patterns, while other variables remained unchanged (p > 0.05). Fermentative losses were also affected as SCF increased gas losses (p < 0.001), reduced effluent losses (p < 0.001), and lowered dry matter recovery (p = 0.002). Microbial counts indicated no changes in lactic acid bacteria (p > 0.05), but yeast populations were reduced (p = 0.048). Aerobic stability decreased with SCF, as exposure time was shortened (p < 0.001), and silage pH increased during the first 48 h of air exposure (p < 0.001). In conclusion, the addition of 5% SCF improved nutritional value but did not enhance fermentation and reduced aerobic stability of sugarcane top silage.

This study evaluated the effects of different container materials and structural designs on the production and early field performance of clonal Eucalyptus spp. seedlings. Biodegradable containers made from polylactic acid, with or without side openings and combined or not with sawdust, were compared to polypropylene tubes and a biodegradable cellulose container under both nursery and field conditions. Shoot height, root collar diameter, dry biomass, and root system morphology were evaluated, along with initial container biodegradation. The results showed that the type of container material and design significantly influenced the morphological attributes of Eucalyptus seedlings during the nursery phase. Specifically, the presence or absence of side openings affected shoot development, root system morphology, and biomass accumulation. Despite these differences observed in the nursery, all seedlings demonstrated comparable height and diameter growth after being planted in the field. This suggests that initial morphological variations became less pronounced under environmental conditions. Furthermore, the biodegradation analysis indicated that both the material and design of the containers affected decomposition patterns, suggesting that decomposition rate aligns with the seedlings’ physiological needs, particularly during early root growth. Overall, the findings suggest that, when designed thoughtfully, biodegradable containers have the potential to replace conventional plastic models without compromising seedling quality or establishment. Nonetheless, further studies are recommended to optimize materials and configurations, evaluate long-term field performance, and support large-scale adoption in sustainable forest nursery systems.

Climate change threatens tropical ecosystems, particularly due to increasing global temperatures. This study investigated how leaf thermal tolerance and thermoregulating structural traits vary among deciduous and evergreen tree species of the Amazonian savanna and whether these traits are reliable predictors of thermal tolerance and contribute to maintaining positive thermal safety margins as air temperatures rise. We measured leaf thermotolerance, thermal safety margins based on air temperature, and morpho-anatomical traits in ten dominant species. Most species exhibited upper thermal limits slightly above the current maximum temperatures. However, under future climate scenarios of + 3 °C and + 6 °C, all species would present negative thermal safety margins. Leaf traits such as spongy parenchyma thickness, abaxial epidermis thickness, total leaf thickness, and stomatal aperture and density were significantly correlated with thermotolerance. Deciduous species showed greater sensitivity to future warming, suggesting that they may be more vulnerable to temperature increases, which could lead to shifts in community composition and structure in the Amazonian savanna. Our results indicate that morpho-anatomical traits play a key role in predicting species’ physiological responses to global warming.