Londrina State University

In this paper we prove the existence of solution for a class of degenerate hyperbolic equations defined in whole space RN. Using some integral estimates we also prove a stability result for the problem. Finally, we also prove a blow-up result when the initial data satisfies an appropriate assumption. The main operator of the equation involves the so called Grushin operator and main goal of this paper is to introduce a new set of mathematical problems in the context of stability and blow-up results.

We investigate the asymptotic dynamics of the two-dimensional Lamé system with linear damping and a fully coupled nonlinear vector field exhibiting exponential growth. A key analytical tool in our approach is the use of a sharp Trudinger-Moser estimate, which allows us to establish crucial quasi-stability and smoothing properties for the corresponding dynamical system. As a consequence, we prove the existence of both global and exponential-type attractors with finite fractal dimension. To the best of our knowledge, this is the first contribution addressing the 2D Lamé system in the evolution scenario with exponential nonlinearity.

Background Biochar, produced through biomass pyrolysis, has been proposed as a strategy for the restoration of degraded dry soils due to its stability and potential benefits. However, knowledge about its impact on the physical structure of degraded drylands remains limited, particularly for biochars derived from co-pyrolysis of sewage sludge with cashew residues.Aims This study evaluated the effects of two biochars applied at distinct rates on the physical properties of a degraded loamy sand soil.Methods A column experiment was conducted in a greenhouse under a completely randomized design (2 & times; 4 + 1) with four replications. Treatments included two biochars obtained from the co-pyrolysis of sewage sludge with cashew pruning residue (SPB) and the pyrolysis of cashew bagasse (CBB), applied at four rates (5, 10, 20, and 40 Mg ha-1), along with a control. Soil density, porosity components, pore size distribution curves, air permeability, pore continuity index, and aggregate stability were analyzed.Results The application of SPB at 20 Mg ha-1 reduced bulk density by 7.74% compared to the control. Porosity components and pore connectivity were primarily influenced by soil reconsolidation over time, with only isolated and inconsistent effects of SPB and CBB. Aggregate size distribution was more responsive: SPB favored larger aggregates, whereas CBB promoted smaller ones.Conclusions Overall, the results indicate that biochar additions can affect specific aspects of soil structural quality, but their impacts are context-dependent and not uniformly expressed across physical attributes.

Lisdexamfetamine dimesylate (LDX) is a psychostimulant, that has been widely recommended in recent years for the treatment of Attention-Deficit/Hyperactivity Disorder. The present study aims to evaluate the effects of LDX administration on the hepatic morphophysiology of pubertal Wistar rats, since the liver plays a central role in systemic metabolism. Male Wistar rats were randomly distributed into two experimental groups: LDX group (LDX) — received 11.3 mg/kg/day of LDX diluted in tap water; and the Control group (C) — received tap water only. Animals were treated by gavage during puberty, from postnatal day (PND) 25 to PND 65. The results showed that administration of LDX decreased white adipose tissue weight without altering overall body weight gain. Plasma biochemical analysis demonstrated an increase in plasma total cholesterol and in the concentration of hepatic transaminases in LDX rats. In addition, LDX animals exhibited an increase in N-acetyl-β-D-glucosaminidase activity, indirectly indicating macrophage recruitment to the liver. This study shows that daily exposure to LDX during puberty causes early liver inflammation and damage due, in part, to increased hepatic transaminases and associated with indirect signs of macrophage recruitment. This finding highlights the importance of monitoring the indiscriminate use of amphetamines and alerting patients to possible liver disorders.

The intensive use of mineral fertilizers increases production costs and environmental impacts, highlighting the need for more sustainable nutrient management strategies. This study evaluated whether hydrochar and biochar, both produced from cashew bagasse, could partially replace mineral fertilizers in degraded soil, using maize as the test crop. A greenhouse experiment was conducted with five fertilization treatments: non-fertilized control (CT), mineral fertilization (MF), hydrochar (HC), biochar (BC), and the co-application of 50