Anais da Academia Brasileira de Ciencias最新文献

While numerous studies in Brazil have investigated plastic interactions with aquatic organisms across various environments, there is no comprehensive overview or identification of research gaps. Using a dataset compiled from scientific studies conducted within the country, we systematically reviewed the current research on plastics in Brazilian aquatic environments. The search yielded 178 publications on plastic interactions with aquatic life in Brazil, published in the past 21 years on plastic pollution in aquatic habitats. Most studies were field-based, assessing plastic ingestion by various organisms. Since 2015, experimental approaches have been developed in the country, with most of studies focusing on particle ingestion by organisms. Fish were the dominant taxonomic group in both field and experimental studies. Microplastics and blue-colored particles were the most studied in terms of size and color. A lack of standardized microplastic sampling and processing methods hinders meta-analyses and regional or national integration levels.

Tenebrio molitor is a key pest of stored products, and the search for sustainable control methods has led to increasing interest in plant-based insecticides. In this study, we evaluated the contact toxicity of thymol, a monoterpene extracted from Lamiaceae plants, against T. molitor larvae. A total of 1,200 fourth- and fifth-instar larvae were exposed to thymol-treated surfaces at concentrations ranging from 0 to 50 gL⁻¹. Larval mortality varied significantly among concentrations, with a clear dose-dependent response. Even at 0.1 gL⁻¹, thymol induced considerably higher mortality than the control group. Mortality rates exceeded 80% at concentrations ≥1 gL⁻¹, and most deaths occurred within the first 24 hours. The LC₅₀ and LC₉₀ values estimated for this period were 0.17 and 2.75 gL⁻¹, respectively, indicating high acute toxicity. These findings confirm thymol's potential as a fast-acting botanical insecticide for the management of stored-product pests. Future studies should investigate its efficacy under real storage conditions, long-term stability, and potential non-target effects.

The broad-snouted caiman (Caiman latirostris) is a key species in South American wetlands with ecological, cultural, and economic importance. Despite its significance, no systematic effort has quantified research trends and gaps. This study integrated bibliometric mapping and systematic review to analyze 484 publications, focusing on geographic distribution, research topics, and collaborative networks. Research is geographically and thematically imbalanced, dominated by Argentina and Brazil, and focused on physiology, toxicology, and reproduction, often under captive settings. Ecological and conservation-oriented studies on habitat-specific dynamics and anthropogenic impacts remain underrepresented. Keyword analysis identifies population ecology, habitat-specific studies, and conservation actions as key gaps. The role of C. latirostris as a sentinel species underscores the need to expand field-based research and conservation strategies that go beyond preserving physical habitats to include pollution control policies. Collaborative networks remain geographically clustered, underscoring the importance of fostering international partnerships. This study provides actionable recommendations to align research with conservation priorities, including prioritizing underrepresented regions, increasing field-based studies, addressing anthropogenic impacts, promoting regional capacity-building, and integrating grey literature into accessible databases. Beyond addressing C. latirostris, the results establish a replicable framework for identifying priorities and research gaps in other taxa, advancing conservation biology by bridging science with practice.

Sedimentation is a fundamental unit operation in the oil industry. For characterizing this phenomenon, understanding the concentration and velocity profiles of particles is essential. Simulating this process requires integrating phenomenological (differential) models with constitutive (algebraic) equations. The inherent complexity of these models often makes simulation time a limiting factor for practical applications. This study aims to utilize Gaussian Process Regression to regularize experimental data points and predict the behavior of volumetric concentration profiles of solids in a particle sedimentation model in Br-Mul drilling fluid, used in the petroleum industry. Concentration was monitored over a 500-day period as a function of height and time, using the Gamma-ray attenuation technique. The numerical results obtained demonstrate that the proposed methodology was able to achieve good estimates for the concentration profiles at different points in the monitored domain. However, it is emphasized that the fluctuation of experimental points can result in physically unfeasible profiles. Finally, it is important to note that the computational cost required for this approach is significantly lower than that typically required by algebraic-differential model simulations.

Glycoside hydrolases are a diverse group of enzymes that act on various α-glucans, exhibiting distinct product specificities. Bioprospecting for bacteria capable of producing novel glycoside hydrolases represents a significant area of interest in biotechnology. This study aimed to isolate glycoside hydrolase-producing bacterial strains from diverse niches from Argentina, including environmental and water sources, starchy and non-starchy plants, and agricultural soils. One hundred and sixty-four glycoside hydrolase-producing strains were isolated from all niches, regardless of their starch content. Notably, 27 isolates exhibited optimal alkalophilic growth at pH 10. The isolates were classified based on the specific glycoside hydrolase they secreted, mainly type I or II pullulanases; α-, β- and α/β-cyclodextrin glycosyltransferases; five categories of maltooligosaccharide-forming amylases; and α-cyclomaltodextrinase. Molecular identification of the isolated strains was performed through 16S rRNA gene sequencing. The genus Bacillus was identified as the primary source of these glycoside hydrolases-producing bacteria. This research provides a valuable source of native bacterial strains that produce glycoside hydrolases with diverse catalytic activities. These enzymes have significant potential for application in various industrial sectors, including food, pharmaceuticals and detergents.

A new species of Scutellaria, S. bahiensis, is described from the state of Bahia, Brazil, where its occurrence to genera not been previously confirmed. It is characterized by the racemes up to 16 cm long, flowers with red corolla, an erect, lobed stigma and blackish nutlets. The new species is compared with Scutellaria incarnata Vent., the most morphologically similar species. Additionally, a full description, illustration, photographs, distribution map, comments on taxonomy, habitat, phenology, line drawings and a preliminary conservation status are provided.

A maternal diet high in saturated fat during critical periods of development is associated with an increased risk of chronic diseases in adulthood. We investigated whether cardiovascular effects in adulthood can be altered by the maternal high-fat diet with flaxseed oil (omega-3) as well as the effects of this diet in dams. Wistar rats were fed during pregnancy and lactation according to the following: control (CT) - standard diet; high-fat (HL) - diet rich in saturated fatty acids; and high-fat with omega-3 (HLꞶ3) - diet rich in omega-3 from flaxseed oil. Body mass, lipid peroxidation, biochemical profile, heart and kidney weights and cardiac hypertrophy index (CHI) were measured in dams. In the offspring, body mass, murine parameters, dietary and water control, systolic and diastolic blood pressure at 60 and 90 days, biochemical parameters, heart and kidney weights, CHI and vascular reactivity were evaluated. In dams, the HLꞶ3 diet delayed the increase in body mass in lactation and reversed oxidative damage in the heart. Therefore, our data suggest that HL diet promotes adverse cardiometabolic effects and the HLꞶ3 diet attenuated the weight gain and oxidative stress in dams, while in the offspring the HLꞶ3 prevented the increase in the Phe-induced contraction.