联邦大学拉夫拉斯

In this paper, we estimate the number of Fq-primitive points on the affine hypersurface defined by the equation f (x1, .. . , xs) = 0, where f is an element of Fq[x1, .. . , xs] is an appropriate polynomial. In particular, we provide existence results for the case when f is Dwork-regular and when f is of Fermat type. Additionally, we provide a proof of a conjecture recently proposed by Takshak, Kapetanakis, and Sharma (2025). Finally, in the case where q is a Fermat prime, we provide an explicit formula for the number of Fq-primitive points on hyperplanes. (c) 2026 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

Sustainable biofuel expansion requires identifying landscapes where new feedstocks can be cultivated without accelerating deforestation, a major source of greenhouse gas emissions in tropical regions. Acrocomia aculeata (maca & uacute;ba), a high-oil perennial palm native to the Neotropics, is a promising feedstock for low-carbon fuels such as sustainable aviation fuel (SAF), hydrotreated vegetable oil (HVO), and biodiesel. However, its large-scale potential remains uncertain because climatic suitability, land-use constraints, and future climate change have not been jointly assessed across its full geographic range. Here, we integrate species distribution modeling with land-use and ecological-constraint mapping to estimate present climatic suitability, identify suitable areas on converted land, and project shifts under future climate scenarios across the Americas. The framework combines current and projected climate, topographic and edaphic variables with pasture and protected-area masks. Under current climate conditions, excluded areas cover 82.4% of South America and 57.7% of regions north of South America. Highly suitable anthropized lands-those with optimal climate and already converted uses such as pastures-represent a smaller but relevant share (1.6% in South America and 2.9% north of South America). The Minimum Temperature of the Coldest Month is the most influential predictor, highlighting strong sensitivity to low-temperature thresholds. Future projections under SSP3-7.0 and SSP5-8.5 maintain the general suitability pattern but expand excluded areas (up to 86.8-89.4% in South America and 70.2% north of South America) and reduce highly suitable anthropized lands. By distinguishing high-and moderate-suitability zones under current and future climates, this study provides a practical framework for climate-aligned bioenergy planning.

Brazilian silage maize production relies on intensive machinery traffic, which may progressively impair soil physical quality under continuous monoculture. This study evaluated whether soybean succession mitigates cumulative soil compaction and preserves soil physical quality in tropical Oxisols managed under silage maize over two consecutive crop seasons. Despite the widespread adoption of silage maize in tropical regions, little is known about how crop succession modifies the temporal evolution of soil compaction and soil physical quality under repeated machinery traffic in these systems. A quasi-experimental time-series design was adopted. Soil samples were collected from the 0–5 and 20–25 cm layers on four sampling occasions. Initial samples were used to develop load-bearing capacity models (LBCM) and identify the initial soil properties, followed by three successive samplings before and after harvest in each crop cycle. Bulk density (Bd), pre-consolidation pressure (σp), total porosity (Tp), microporosity (Mic), macroporosity (Mac), and organic matter (OM) were determined. LBCMs were developed and fitted to a regression model of the type σp = 10(a + bθ). Other soil properties were analyzed using linear mixed models. Crop succession reduced the proportion of compacted samples throughout the study and improved key indicators of soil physical quality, including Bd and Mic. In contrast, continuous silage maize monoculture promoted progressive subsurface compaction, increased microporosity, and reduced Mac. The σp proved more sensitive than Bd for detecting management-induced changes in soil mechanical behavior. Overall, soybean succession mitigated the cumulative effects of repeated machinery traffic, preserving soil physical quality under continuous silage maize production. These findings highlight load-bearing capacity models as valuable tools for monitoring soil compaction and supporting sustainable soil management in tropical production systems.

Fruit ripening is a complex physiological process that determines fruit quality and influences consumer acceptance. Among the various indicators of ripeness, visual appearance plays a decisive role, as it is the first attribute perceived and often defines expectations regarding flavor, freshness, and overall quality. However, conventional maturity assessment frequently relies on analytical procedures that require destructive sampling, are time-consuming, or have limited applicability for real-time and large-scale monitoring. In this context, this review critically examines the potential of visual biomarkers to connect fruit ripening physiology, non-destructive sensing, predictive modeling, and sensory quality. A bibliometric mapping identifies major research trends, while the critical synthesis distinguishes instrumental quality prediction, associations with sensory attributes, and direct prediction or validation of consumer-relevant outcomes. The review integrates the biochemical foundations of ripening with practical approaches, examining how changes in pigments, sugars, texture, and other ripening-related attributes are translated into measurable visual and spectral features. Imaging and sensing technologies, including RGB, near-infrared, hyperspectral, and thermal approaches, are discussed alongside image processing, chemometrics, and machine learning. Although these technologies can achieve strong performance in maturity classification and physicochemical quality prediction, high instrumental predictive accuracy does not necessarily establish sensory relevance. Sensory evaluation can address this gap either by providing prediction targets or by serving as an independent reference for validating whether instrumentally detected changes correspond to perceived quality. Overall, standardized protocols, external validation, model transferability, and sensory integration from the experimental design stage are needed to advance robust and consumer-relevant fruit ripeness prediction.

Hydrothermal humic acids (HHA) have attracted attention due to their redox-active properties and potential for lignocellulosic waste valorization. However, the effects of alkaline hydrothermal extraction temperature on their molecular organization and antioxidant activity remain poorly understood. This study investigated the influence of extraction temperature (120-200 degrees C) on the structural characteristics and antioxidant properties of HHA produced from sugarcane straw hydrochar, with humic acid obtained by conventional alkaline extraction at 90 degrees C (HA90) included for comparison. HHA were characterized by SEM/EDS, elemental analysis, TGA, FTIR, and one-and two-dimensional NMR spectroscopy, together with measurements of total acidity and carboxylic and phenolic hydroxyl groups. Total phenolic content was determined, and antioxidant activity was evaluated by DPPH radical scavenging. Extraction yields remained similar among treatments, whereas increasing temperature promoted changes in chemical composition, thermal stability, and the distribution of oxygen-containing functional groups. 1H NMR showed an increase in the relative contribution of the delta 1.6-3.0 region, from 13.35% in HA90 to 21.13% in HHA200. HSQC and HMBC analyses indicated the presence of methoxyl groups associated with lignin-derived oxygenated aromatic structures. Increasing extraction temperature enhanced total phenolic content from 85.32 to 146.56 mg GAE g-1 and improved antioxidant activity, with IC50 decreasing from 1.34 to 0.72 g L-1. Exploratory correlation analysis indicated significant associations between antioxidant activity, phenolic content, phenolic hydroxyl groups, and other chemical constituents. The alkaline hydrothermal extraction modified the molecular organization and antioxidant properties of HHA, supporting the valorization of sugarcane residues into redox-active humic materials.