The Federal University of Grande Dourados (Portuguese: Universidade Federal da Grande Dourados, UFGD) is a Brazilian public institution which is located in the city of Dourados, state of Mato Grosso do Sul, Brazil..
The use of plant-derived nutraceuticals in aquaculture has increased, including in ornamental species. Guavira (Campomanesia guazumifolia) is a native Cerrado plant with reported antioxidant and anti-inflammatory properties. This study evaluated the toxicity and functional effects of C. guazumifolia leaf decoction as a feed additive for Geophagus pyrocephalus. Acute toxicity assays were conducted using Artemia salina (1.5–1000 µg mL⁻¹) and juvenile fish (0.1–500 µg mL⁻¹), alongside a 30-day feeding trial with dietary inclusion levels of 0, 250, 500, 1000, and 2000 mg kg⁻¹. The decoction exhibited high toxicity, with LD₅₀ values of 23.29 µg mL⁻¹ for A. salina and 50.03 µg mL⁻¹ for G. pyrocephalus. In fish, mortality increased markedly at concentrations ≥ 100 µg mL⁻¹, accompanied by elevated plasma glucose and severe gill lesions, including epithelial hyperplasia, lamellar fusion, and necrosis. Despite this toxicity, dietary supplementation at 250 mg kg⁻¹ significantly enhanced muscle antioxidant activity, with superoxide dismutase (SOD) levels increasing by approximately 2.5-fold compared to the control (p < 0.05), without affecting growth performance or survival. In contrast, higher inclusion levels (≥ 1000 mg kg⁻¹) were associated with reduced condition factor and increased hepatic alanine aminotransferase (ALT), indicating metabolic stress. In conclusion, C. guazumifolia leaf decoction presents a narrow safety margin, combining pronounced toxicity at relatively low concentrations with beneficial antioxidant effects at low dietary inclusion. The dose of 250 mg kg⁻¹ is suggested as a safe and functional level for G. pyrocephalus, highlighting the importance of dose optimization for its application in ornamental aquaculture.
Emerging micropollutants, particularly endocrine disruptors like 17β˗estradiol (E2), pose significant environmental and health risks due to their toxicity and bioaccumulation. This work presents the development of a novel, cost˗effective electrochemical carbon sensor, screen˗printed on a commercial PVC substrate, for the sensitive and selective detection of E2. The sensor’s working electrode was modified through a layer˗by˗layer deposition of Vulcan XC72R carbon (2.5 mg mL˗1) dispersed in chitosan (0.5
This study reports the development and application of a voltammetric sensor for the simultaneous detection of carbendazim (CBZ), using a glassy carbon electrode (GCE) modified with hydrothermal carbon black, MXene, and PEDOT: PSS as a conductive polymeric binder (MXene-CBH-PEDOT/GCE). The electrode surface was modified by drop-casting the MXene-CBH dispersion on it, while morphological characterization of the materials was performed by scanning electron microscopy (SEM). The electrochemical behavior of CBZ was studied using cyclic voltammetry in the potential range of 0 to 1.2 V. An oxidation peak was observed during the anodic scan at a potential of 0.75 V. Compared to the bare GCE, the anodic peak currents (Ip.a.) recorded for the MXene-CBH-PEDOT/GCE sensor was significantly higher (recorded an increase in peak current by a factor of 5.1). The results obtained from SWV under optimized conditions showed that the proposed method exhibited linear concentration ranges from 5.0 × 10−7 to 3.8 × 10−5 mol L−1 for CBZ, with a limit of detection (LOD) of 7.0 × 10−8 mol L−1. The MXene-CBH-PEDOT/GCE sensor exhibited excellent repeatability with no interference effects when applied for CBZ detection in the presence of potential interfering compounds. The proposed method was successfully applied for CBZ (two concentration levels) determination in orange juice and environmental samples, where recovery rates of approximately 100
Floodplain forests are naturally fragmented ecosystems shaped by seasonal hydrological dynamics, yet their role in structuring insect communities, particularly social wasps, remains poorly understood. We investigated the community structure of social wasps across 44 floodplain forest fragments in Rio Ivinhema State Park, Mato Grosso do Sul, Brazil. Using both passive and active sampling, we evaluated the effects of foraging site (forest vs. matrix), vegetational successional stage, and fragment size on species richness and assemblage composition. We recorded 953 individuals belonging to six genera and 17 species, with Agelaia pallipes as the dominant species. Species richness did not differ significantly between forest and matrix habitats, nor was it directly influenced by successional stage. Fragment size showed a marginally positive effect on species richness, particularly in recovering forests. Species composition varied across successional stages, suggesting the influence of environmental filtering. Our findings indicate that, despite the ecological plasticity of social wasps, their assemblages respond to variation in habitat structure across floodplain landscapes. The relationship between fragment size and species richness appears to be context-dependent, being more pronounced in early stages of forest regeneration, reinforcing its importance in shaping community patterns. These results suggest that conservation in floodplain ecosystems should prioritize larger forest fragments, especially in early-successional stages, while maintaining habitat heterogeneity between forest and matrix environments. This may promote the persistence of social wasps and the ecological functions they provide.
The main objective of this systematic review was to consolidate current knowledge about the challenges and barriers to implementing digital services in public administration. The Proknow-C method and PRISMA flowchart were used to identify 1,613 studies and select 85 relevant articles (2019–2024) in the Scopus and Web of Science databases. The analysis revealed a clear gradient of technological sophistication, ranging from disruptive technologies (artificial intelligence, big data, blockchain) in developed countries to a focus on basic digital infrastructure in underdeveloped countries. Seven categories of barriers were identified, with institutional/organizational barriers being universal. However, the main analytical contribution lies in the contextual differentiation (by level of development) of the identified barriers. The contextual analysis demonstrated that the prevalence of economic and technical barriers varies dramatically, these being a critical and limiting factor in countries with lower Human Development Index scores. The findings highlight the need for contextualized strategies. The study proposes a “Contextual Barriers Matrix Framework” to guide managers and researchers. It concludes that the success of digital transformation depends on an accurate diagnosis of the local stage of development in order to prioritize overcoming the most relevant obstacles.
