The stability of stopes in underground mining is a critical factor for both operational safety and the economic viability of mining projects. Empirical methods, such as Potvin's Stability Graph (1988), are widely used to predict stability conditions; however, their applicability may be limited in distinct geomechanical scenarios. In this context, this study proposes a quantitative approach based on multivariate regression for predicting dilution throughout the development of different stopes in underground mining. To achieve this, various regression techniques were tested, including linear, polynomial, exponential, and logarithmic models, aiming to predict unplanned dilution based on 18 independent variables related to operational, geotechnical, and structural parameters. The results indicated that second-degree polynomial regression exhibited the best performance, achieving a coefficient of determination (R2) of 82.6% and an absolute mean error below 4%. Statistical analysis revealed that variables such as vertical stress, stope depth, and specific drilling index significantly influence dilution prediction, highlighting the need for an integrated approach between geomechanical and operational factors. Thus, the findings of this study underscore the importance of developing methodologies tailored to local geomechanical conditions, contributing to the optimization of underground mining planning, the reduction of operational losses, and the improvement of extraction efficiency.
Urban soils act as long-term reservoirs for trace metals, yet how soil physicochemical properties and anthropogenic pressure interact over time remains poorly understood in medium-sized cities of the Global South. This study evaluates the spatiotemporal dynamics and ecological risks of Ba, Cu, Zn, Pb, Cr, Ni, Mo, Co, and Cd in urban topsoils, through a 33-week monitoring campaign. Linear Mixed Models (LMM) and Positive Matrix Factorization (PMF) were combined to identify retention controls and source contributions. No significant temporal variability was observed (p > 0.05), confirming soil as a stationary reservoir, whereas marked spatial heterogeneity occurred (p < 0.001), driven by localized soil properties. LMM results highlighted soil organic matter (SOM) as a key enhancer of Cu (β = 6.15) and Zn (β = 17.9) retention, while pH exerted a strong negative control on Pb mobility (β = -23.9 x 104). PMF identified three major contributors: geogenic sources (35.9%), industrial/traffic emissions (32.4%), and mixed anthropogenic-lithogenic inputs (30.7%). Although metal concentrations remained below intervention thresholds, localized Cd-driven ecological risks persist in densely populated areas. This study highlights that vegetation and SOM function as vital geochemical sinks for metal immobilization, offering effective pathways for sustainable urban risk mitigation.
The application of triazole fungicides in agriculture has raised concerns regarding their potential deleterious effects on human health. Thus, the present study aimed to evaluate the in vivo cardiotoxicity of fungicides difenoconazole (DFZ) and prothioconazole (PRZ), in Wistar rats subjected to daily administration of 1 mg/kg/day, corresponding to the non-observed adverse effect level (NOAEL), by gavage over a period of 28 consecutive days. No significant alterations were observed in the weights of the heart, right atrium, left atrium, spleen, liver, and lungs of the animals. Histopathological analyses of the myocardium revealed no evidence of cardiac hypertrophy. Electrocardiographic assessments did not indicate significant changes in P wave duration, PR and QT intervals, QRS complex, or RR interval. Furthermore, during the cardiac stress tests induced by caffeine and dobutamine, DFZ and PRZ did not increase the likelihood of developing cardiac arrhythmias, nor did they augment the infarct area as measured by TTC/Evans Blue staining. Also, serum levels of the cardiac biomarkers CK-MB and LDH were comparable to those of the control group. Collectively, these results suggest that DFZ and PRZ, at the administered dose and time frame, do not induce structural or electrical alterations in the hearts of rats.
Regional inequalities in basic sanitation remain a major public health challenge in Brazil. This study assessed the relationship between sanitation indicators and health outcomes related to Diseases Related to Inadequate Environmental Sanitation (DRSAI) in Brazilian capitals from 2010 to 2019. Mortality and hospitalization data were obtained from DATASUS, and water and sewerage coverage indicators from the National Sanitation Information System (SNIS). Pearson correlations and hierarchical cluster analyses were used to explore spatial patterns and associations. Pronounced regional disparities were observed. Northern and Northeastern capitals, including Macapá, Recife, and Salvador, had the highest DRSAI mortality and hospitalization rates, coinciding with the lowest sewerage coverage (<30%) and limited potable water access (<60%). In contrast, Southern and Southeastern capitals, including Curitiba, Porto Alegre, and São Paulo, showed better sanitation and health indicators. Sewage coverage was significantly and negatively correlated with hospitalization and mortality rates (p<0.05), indicating an inverse association between sanitation coverage and DRSAI outcomes. The findings highlight the central role of sanitation in reducing inequalities in DRSAI-related hospitalizations and mortality. Despite progress, universal access remains distant and requires targeted investments and integrated public policies to improve sanitation and public health outcomes in Brazil, particularly in the country's most socially vulnerable urban areas.
The lignin extracted from the leaves of Crataeva tapia was investigated for its antimicrobial activity and potential use in solid pharmaceutical formulations. The leaves contained 35% cellulose, 23.4% hemicellulose, 17.3% lignin, 19.1% extractives, and 4.7% ash. The extraction yield after acid precipitation was 67.8%. Cytotoxicity assays in RAW 264.7, J774, Vero, V79, and HepG2 cells showed low toxicity (IC50 >1000 µg/mL) and no hemolytic activity (<10%). Lignin exhibited MIC values ranging from 512 to >1024 µg/mL, with no MBC or MFC detected. The best antibacterial result was observed against Staphylococcus aureus UFPEDA-709 (MIC 512 µg/mL), comparable to oxacillin. Among Candida strains, notable results were obtained for HAM11 (128 µg/mL; fluconazole 0.5 µg/mL) and HAM13 (128 µg/mL; fluconazole 4 µg/mL). No synergism was observed against bacteria, but additive and synergistic effects were detected in HAM11 and HAM13, respectively. Lignin reduced HAM13 biofilm formation by 16%. Ergosterol assays suggested its action on fungal cell walls and membranes. Tablets containing lignin showed hardness of 5.5 Kgf/cm², friability of 0.93%, and disintegration in 36.2 min, while those without lignin showed 4.6 Kgf/cm², 0.15%, and 31 min, respectively. These findings highlight C. tapia lignin as a versatile and promising biomaterial for sustainable fluconazole-based formulations and adjuvant therapies.
The COVID-19 pandemic raised concerns about increased mental health morbidity, yet limited evidence exists on how demand for mental health care manifested in primary care settings during this period. This study evaluated cases of anxiety and depression with conclusive ICD-10 diagnoses recorded in medical records, examining associations with age group, sex, and the pre- versus pandemic context. The sample consisted of 8,365 individuals (6,038 females, 2,316 males; mean age 45.5±16.1 years) who sought spontaneous medical care at Basic Health Units (BHUs) between the pre-pandemic period (2019; n=2,600) and the pandemic period (2020-2022; n=5,755). Contrary to expectations, no significant increase was observed in the proportion of consultations for anxiety (P=0.7) and depression (P=0.4) during the COVID-19 pandemic compared to the pre-pandemic period. However, significant shifts within subgroups were identified: elderly individuals (≥65 years; n=1,382) showed 82% higher odds of depression compared to younger adults, while males had 12% higher odds of anxiety compared to females. These findings reveal that while the pandemic did not lead to a proportional increase in formal mental health diagnoses at primary care level, it was associated with significant demographic shifts particularly higher depression risk among the elderly and elevated anxiety risk among males.
Gout is an inflammatory disease caused by monosodium urate (MSU) crystal deposition, triggering NLRP3 inflammasome activation, interleukin-1β (IL-1β) release, and P2X7 receptor-mediated amplification of inflammation. This study evaluated the anti-inflammatory effects of methyl gallate (MG) and its interaction with the P2X7 receptor. MG reduced IL-1β production in activated macrophages, inhibited P2X7-dependent membrane pore formation, and produced effects similar to those of the selective P2X7 antagonist A740003. In a murine gout model, MG decreased joint edema, leukocyte accumulation, and IL-1β levels. Computational analyses demonstrated stable MG binding to P2X7, highlighting its potential as a therapeutic candidate for gout treatment.
Floods are among the most harmful natural disasters for humans, and rising global temperatures tend to make them more frequent. This paper aims to model flood susceptibility in Rio de Janeiro, Brazil, based on the 2019 and 2020 floods. The methodology used in the paper is based on the Analytical Hierarchy Process. The contribution of variables to extreme flood events was calculated to assess the influence of oceanic tides in conjunction with the extreme rainfall. The methodological procedures were mainly based on acquiring data referring to rainfall records, ocean tide oscillations, and other natural-anthropogenic variables. The results showed that ocean tidal oscillation in that region has played a secondary but essential role in flood events. Furthermore, observing ocean tide dynamics and extreme rainfall events is the key combination for explaining, preventing, and forecasting extreme flood events. For future research, it is recommended that the improvement of quality data (geodetic and meteorological) is essential to model flood susceptibility in coastal areas.
COVID-19 is caused by the SARS-CoV-2 coronavirus. Vaccine development was essential for reducing hospitalizations and mortality during the pandemic. In Brazil, the ChAdOx1-S/nCoV-19 (AstraZeneca) vaccine was widely administered during the initial phase of the national immunization campaign. Despite a well-established safety profile, continuous surveillance of adverse events remains important. Mild adverse reactions occurred more frequently after the first dose and were generally self-limiting. The vaccine induced a strong IgG antibody response, demonstrating robust immunogenicity while producing minimal changes in liver function parameters. These findings support the favorable safety, tolerability, and immunogenic profile of the ChAdOx1-S/nCoV-19 vaccine in this population.
Harmful cyanobacterial blooms pose risks to the environment, humans, and animals. Rapid identification of these microorganisms is essential but still relies on costly and time-consuming techniques. This study evaluates the potential of attenuated total reflectance infrared spectroscopy (ATR-FTIR) combined with chemometrics, supported by molecular methods, to detect potentially harmful cyanobacteria. Samples were collected from 14 sites in the Rio Pardo Valley, RS, Brazil, with limnological parameters measured. Spectra (4000-650 cm⁻¹) in triplicate, and 16S rRNA metabarcoding was performed using Dada2, Phyloseq, and the CyanoSeq database. PCA and OPLS analyses were applied to integrate spectral, taxonomic, and environmental data. Twelve cyanobacterial genera were identified. Sphaerospermopsis (Zapomelová et al., 2010) dominated SP14, associated with aluminum, iron, and nitrogen levels. Dolichospermum ((Bornet & Flahault) P. Wacklin, L. Hoffmann & Komárek, 2009) and Wollea (Bornet & Flahault, 1886) correlated with phosphorus and sodium. Planktothricoides (S. Suda & M. Watanabe, 2002) showed 95.15% abundance at SP01. PC1×PC2 plots revealed location-based clustering of spectral data. ATR/OPLS models showed strong correlations with relative abundances derived from metabarcoding data, with RMSECV values from 1.3×10⁻⁵ to 5.3×10⁻⁴ and R² > 0.99. These results support ATR-FTIR and chemometrics as a promising exploratory approach for the assessment of cyanobacterial community composition in freshwater systems.
During a taxonomic revision of the Brazilian species of Malanea, a new species endemic to the Atlantic Forest of Brazil was discovered and is described here. The new species occurs in the submontane forest in Espírito Santo and differs from all the other species from the Atlantic Forest by its branchlets, stipules, petioles and leaves with golden villous trichomes, and fruits oblong slightly curved. Besides the diagnosis and description, we provide taxonomic comments, illustrations, a distribution map, and a preliminary conservation status assessment.
Areas of endemism are geographic units characterized by unique biological diversity and evolutionary histories, enabling the formulation of hypotheses about the processes shaping regional ecosystems. Aquatic insects are essential components of freshwater environments, and the genus Ranatra Fabricius, 1790 is commonly found in slow-flowing streams rich in leaf litter and submerged roots. Known as "water scorpions", 35 species have been reported across Brazil to date. Despite growing research efforts, substantial gaps remain regarding the diversity of these insects, particularly in terms of species identity (Linnean shortfall) and distribution (Wallacean shortfall). In this study, we present a species list of Ranatra Fabricius, 1790 from streams of the Xingu Basin, Pará State, a region located within the Tapajós and Xingu Areas of Endemism in the Brazilian Amazon. We sampled 165 individuals belonging to 13 species, including three new distributional records for the state of Pará, R. brasiliensis De Carlo, 1946, R. doesburgi De Carlo, 1963, and R. rabida White, 1879. Our findings emphasize the importance of expanding research and monitoring efforts in freshwater systems, particularly in highly diverse regions increasingly threatened by anthropogenic pressures and climate change, such as those of the Amazon biome.
The Pampa biome is increasingly threatened by anthropogenic pressure and climate change, which intensify thermal extremes, water scarcity, and soil salinity, negatively affecting seed production and dispersal. This study evaluated the effects of thermal, water, and salinity stresses on the germination and vigor of Neltuma affinis and Vachellia caven, two ecologically and economically important Fabaceae species native to the Pampa parklands. The seeds were subjected to different temperatures (15, 25, 30, and 35 °C), polyethylene glycol (PEG) concentrations (0.0, -0.41, -0.58, and -0.79 MPa), and NaCl concentrations (0.0, -0.46, -0.92, and -1.37 MPa). Germination of N. affinis was not observed at 15 or 35 °C, whereas V. caven failed to germinate only at 15 °C. Under water stress, both species showed reduced germination and germination speed index (GSI). While V. caven demonstrated tolerance to salinity, N. affinis germination and GSI were inversely proportional to salinity. Overall, V. caven showed tolerance to thermal and saline stress, whereas N. affinis was significantly more sensitive to abiotic stresses. Given the limited distribution of N. affinis in Brazil, together with ongoing anthropogenic pressure and increasing climatic extremes, this species may be at risk of extinction due to reduced germination capacity and seed vigor.
Abstract Vitex megapotamica (Tarumã) fruits are a potential source of phenolic compounds with relevant biological activities. This study compared ultrasound-assisted extraction (UAE) using a probe-type ultrasonic apparatus with conventional shaker extraction for the recovery of bioactive compounds from ripe Tarumã fruits. UAE extraction kinetics were evaluated at 5, 10, 15, and 30 min (90 °C, 60% amplitude). The extracts were evaluated for their highest total phenolic content (TPC), antioxidant, and anti-inflammatory activities. The TPC was obtained after 5 min of extraction, and this condition was selected for comparison with shaker extraction under the same parameters. UAE significantly increased phenolic recovery, reaching 1909.2 mg GAE 100 g⁻¹ of sample, whereas the shaker method yielded 1549.5 mg GAE 100 g⁻¹. Despite the higher phenolic extraction efficiency, antioxidant and anti-inflammatory activities did not differ significantly between extracts (p > 0.05). High-performance liquid chromatography analysis (HPLC) revealed ellagic acid as the predominant compound in the UAE extract, while myricetin was the major phenolic compound identified in the shaker extract. These results demonstrate that UAE is an efficient and rapid technique to enhance the recovery of phenolic compounds from Tarumã fruits, supporting its potential application in the development of bioactive extracts.
Abstract Melochia (Byttnerioideae – Malvaceae) is widely distributed across tropical and subtropical regions. In Brazil, however, its distribution, species richness, diversity, and endemism remain poorly understood. The present study aimed to analyze the biogeography of Melochia and infer which distribution patterns best reflect its geographic distribution in Brazil and where its centers of diversity and endemism are located. Species occurrence data were compiled from online databases, resulting in 4,136 cleaned records representing 27 species. Richness and diversity analyses were conducted using DIVA-GIS, while QGIS was used to create the distribution maps. Parsimony Analysis of Endemicity was performed with PAUP. Our results indicate that most Melochia species are widely distributed. Seven areas of diversity were identified: Pantanal, Central Brazilian Cerrado, Northern and Southern Espinhaço Range, Serra dos Carajás, Tapajós, and Raposa Serra do Sol Indigenous Land. Two areas of endemism were detected: Chapada Diamantina, and Chapada do Araripe. These patterns highlight the ecological relevance of Melochia across varied environmental gradients and its biogeographical structure, particularly in the Central-West and Espinhaço Range. The study also reveals significant knowledge gaps and underrepresentation of certain species in herbarium collections and databases, stressing the need for increased botanical exploration and habitat protection.
We present three new records of C. hudsoni, a secretive and small-sized Amazonian species of frog, from the municipalities of Barcarena, Santa Bárbara, and Primavera, all in the state of Pará, Brazil. These records extend the known species distribution in 520 km account to the first geographical records from the Belém Area of Endemism (BAE), the most threatened region of the Amazon basin. The records have relevant implications for several aspects of the biology of Chiasmocleis, especially biogeography, taxonomy, and conservation.
Abstract Intermittent fasting is becoming popular for its quick benefits on body composition. With rising interest in weight loss, understanding its impact on fat-free mass is essential. It investigates the effects of time-restricted feeding compared to conventional diets on body composition in healthy adults undergoing resistance training. The registration is in PROSPERO (CRD42023423274), and ethical approval was not required. No financial support was received. Databases consulted included MEDLINE, CENTRAL, Embase, and Scopus, with the final search conducted on November 13, 2023. Only randomized controlled trials with healthy human participants aged 18 or older, who underwent TRF and strength training, were included. The risk of bias was assessed using the RoB2 tool. The review comprises 5 studies, with a final sample of 120 individuals. Among them, only 2 studies showed a statistically significant difference in the impact of fasting on body weight and fat mass. Regarding fat-free mass, it remained consistent across groups at the intervention’s end. The meta-analysis suggested an estimate of -0.48kg (95% CI: -2.52 to 1.56), indicating that the average result did not significantly differ from zero. Contrary to the initial hypothesis, the findings do not provide statistically significant evidence that TRF increases fat-free mass.
Due to the critical state of biodiversity loss, the valuation of biodiversity-related ecosystem services is fundamental for assertive policy-making and sustainable development. This study assessed these services in the São Francisco Xavier Environmental Protection Area in Brazil. The objective was the economic value of aspects of biodiversity, considering the conservation of ecosystems. The method involved identifying relevant ecosystem services associated with local biodiversity and the corresponding economic indicators, then assessing the biodiversity status of the area and integrating this as a weight in the valuation equation. The total economic value of ecosystem services in EPA-SFX was US$4,684.81 per hectare. The study concluded that current financial incentives for biodiversity conservation, such as the Payment for Environmental Services programs, were insufficient compared to the intrinsic value of ecosystem services. The findings emphasize the need to reform valuation models and establish effective financial mechanisms for biodiversity conservation. They also demonstrated that incorporating habitat quality into the valuation equation enhanced the accuracy of the results, bringing them closer to the local context, representing an innovative contribution to this study.
Abstract Floods are among the most destructive natural disasters, necessitating accurate and timely prediction systems to mitigate their impact. This study evaluates the performance of two machine learning models, − K-Nearest Neighbors (KNN) and Long Short-Term Memory (LSTM) networks − in predicting daily water levels based on hydrological and meteorological data from the Wupper River in Wuppertal, Germany. The KNN model yielded the best accuracy ($\text{R
Abstract Nematodes of the family Cystidicolidae Skryabin, 1946 represent a complex group of parasites of aquatic organisms. They are present in freshwater, estuarine, and marine environments, with fish as intermediate, paratenic, and definitive hosts. This study adds relevant data on the morphology, morphometry, and parasitic ecology of third-stage larvae of Pseudoproleptus Khera, 1953 in fish consumed by riverside populations in the Amazon. A total of 92 fish specimens were acquired between March 2024 and January 2025 from artisanal fishing, distributed among five species: Astronotus ocellatus; Cichla ocellaris; Cynoscion microlepidotus; Gymnotus carapo; and Hoplerythrinus unitaeniatus. Nematodes were recovered free and encysted in the visceral peritoneum, coelomic cavity, and lumen. The parasites collected had morphological characteristics compatible with the genus Pseudoproleptus. This is the first record of Pseudoproleptus infection in Gymnotus carapo and has provided new data on the biodiversity of larvae that parasitize fish in the Marajó region, Pará, Brazilian Amazon.
