Search Results (1,062)

Plant diversity plays a fundamental role in ecosystem functioning and is essential for sustaining ecosystem services. National forest inventories are key instruments for assessing floristic diversity. However, their measurement protocols may introduce bias by omitting smaller individuals because of the stem diameter criterion used or the minimum plant size threshold applied. Such bias is exacerbated in dryland ecosystems where small-statured plants with low-branching stems are particularly abundant. In this study, we evaluated the effects of using basal diameter (BD) instead of diameter at breast height, and of sampling small individuals (BD ≥ 2.5 cm), on the estimation of abundance, alpha and gamma diversity and community composition in different vegetation types in NW Mexico. We found substantial underestimation due to the omission of smaller individuals in xeric shrubland and tropical dry forest, where gamma diversity may be underestimated by up to 209% and 139%, respectively. Broadleaf forest also showed strong underestimation (133%), whereas mixed conifer–broadleaf forests were unaffected. We discuss these differential effects and propose a methodology to attenuate this underestimation and achieve more accurate floristic diversity estimates from national forest inventories in dryland vegetation, which encompasses roughly one-third of the Earth’s surface and more than half of Mexico’s territory. Full article

The Eastern Tropical Pacific (ETP) comprises several coral ecosystems, which are distributed across a variety of coastal zones and oceanic islands. In these ecosystems, reef fish play key roles in their functioning. In ETP, there is a paucity of studies that have evaluated fish functional diversity (FD) and compared oceanic and coastal systems from a predominantly trophic perspective. A comparative analysis was conducted on fish FD in seven coral ecosystems, encompassing three distinct environmental contexts: (1) Oceanic, (2) Coastal-influenced, and (3) Coastal. The hypothesis that FD varies spatially along this oceanic–coastal gradient is predicated on the premise that such variation is attributable to differences in disturbance regimes and environmental conditions. Our results show that not all functional α-diversity indices exhibited significant variation among zones. However, analysis of functional dominance, divergence, dispersion, and β-diversity analyses revealed clear spatial variation in functional structure, partially supporting expectations related to disturbance regimes across the oceanic–coastal gradient. These patterns may be indicative of increasing disturbance intensity, in conjunction with other interacting processes such as variability in larval supply, recruitment dynamics, and environmental conditions, including fishing pressure, sedimentation, nutrient inputs, and coastal upwelling. The findings of this study demonstrate the efficacy of functional diversity metrics in assessing reef fish responses to both natural and anthropogenic disturbances. In addition, the present study offers actionable insights with regard to the formulation of conservation and management strategies in the Mexican Eastern Tropical Pacific. Full article

This study compares the performance of XGBoost and LightGBM models for predicting live weights of Yucatecan Criollo pigs from biometric measurements and examines the structural and algorithmic differences that affect model fit. Detailed analysis of the models’ hyperparameter optimization and variable importance revealed how each model approaches the data and prioritizes features. This study was conducted on 182 Yucatecan Criollo pigs (134 females and 48 males). When model performances were evaluated, the XGBoost model showed superior prediction performance with acceptable accuracy and lower error rates in the test dataset, with R² = 0.905, RMSE = 5.704, and MAE = 3.636. In contrast, the LightGBM model produced acceptable results under certain hyperparameter combinations with R² = 0.824, RMSE = 7.772, and MAE = 5.505. While the robust performance of both models requires strategic decisions in model selection and optimization, it is recommended to consider the dataset’s nature in feature selection and hyperparameter settings. This study provides important insights for simplifying the model and improving its efficiency in machine learning applications, and serves as a reference for more effective model use. Full article

The objective of this study was to evaluate essential oils (EOs) as an alternative control method for Rhipicephalus microplus and Amblyomma mixtum larvae. The EOs used were obtained by steam distillation from the leaves of cinnamon (Cinnamomum verum), mexican mint (Plectranthus amboinicus), lemongrass (Cymbopogon citratus), peppercorns (Pimenta dioica), and peruvian pepper tree (Schinus molle). To evaluate the acaricidal effect of EOs against the larvae of two tick species, a larval immersion test (LIT) was performed using six concentrations (10 mg/mL, 5 mg/mL, 2.5 mg/mL, 1.87 mg/mL, 1.25 mg/mL, and 0.6 mg/mL), in addition to a negative control group (water + ethanol) and three positive controls (organophosphate, formamidine, and pyrethroid). LIT results were obtained 48 h after exposure. Data were processed using Probit procedure to determine the lethal concentrations at 50% (LC₅₀), 95% (LC₉₅), and 99% (LC₉₉). For R. microplus, 99% mortality was obtained at concentrations as low as 1.4 mg/mL for S. molle, while the highest LC₉₉ was recorded with P. dioica at 23 mg/mL. In the case of A. mixtum, higher concentrations were required to achieve a high mortality rate. EO of P. amboinicus had the lowest acaricidal effect, requiring 26.2 mg/mL to achieve an LC₉₉, while S. molle required a concentration of 6.9 mg/mL to achieve an LC₉₉. Full article

Zoonotic diseases involve pathogen transmission between humans and animals, with most research focused on animal-to-human spillover. However, reverse zoonosis—the transmission of pathogens from humans to animals—remains understudied despite its potential ecological and epidemiological consequences. The SARS-CoV-2 pandemic highlights this risk, as human-associated viruses may sporadically infect wildlife species and generate novel exposure pathways. To assess evidence of SARS-CoV-2 exposure in wildlife, we analyzed serum and rectal swab samples from rodents collected in rural localities of the Yucatan Peninsula, Mexico, between 2021 and 2022. An indirect ELISA detected antibodies against SARS-CoV-2 in 23.1% of sampled rodents. Molecular analysis detected one positive sample with a pan-coronavirus RT-PCR, though all were negative for SARS-CoV-2–specific assays. This study provides serological evidence of SARS-CoV-2 exposure in rodent communities from rural areas of Mexico and is consistent with sporadic wildlife spillback events rather than sustained transmission. The observed exposure patterns may be influenced by human activities and frequent human–wildlife interactions in heterogeneous rural landscapes. Our results underscore the need for integrated serological and genomic surveillance to better understand the ecological context of reverse zoonosis and its implications for public health. Full article

Nanoparticle powders of a Ce_1−xRu_xO₂ mixed oxide (3.0% w/w), were synthesized to be used as catalytic supports, on which Pt and Ir nanoparticles were deposited as the active phase. The catalytic supports were prepared through a route involving microwave heating, while the Pt or Ir nanoparticles were incorporated via the wet incipient method. The {Pt, Ir/Ce_1−xRu_xO₂} catalytic systems were successfully tested as catalysts for low-temperature CO oxidation. To provide adequate support to our results, the compounds were characterized by SEM, EDS, XRD, DRS-UV-vis, and XPS techniques. In addition, BET isotherms were carried out to determine specific surface area features. The CO oxidation evolution was tested in the range of 25–350 °C. Both Pt and Ir supported Ce_1−xRu_xO₂ catalysts that remarkably improved the CO oxidation, reaching and sustaining 100% conversion from 125 °C onwards. Remarkably, the mixed oxide support, by itself, showed outstanding performance, achieving 100% conversion to CO₂, at a temperature of 225 °C. Full article

Long-term monitoring is essential for understanding how recurring disturbances, such as hurricanes and coral bleaching, affect reef fish communities and ecosystem processes. This study evaluates temporal trends (2013–2025) in fish assemblage composition, functional diversity, and nutrient excretion proxies (C, N, and P) across three reef sites on San Andrés Island in the Colombian Caribbean. Our results reveal significant shifts in community structure following major disturbances in 2020 (Hurricanes Eta, Iota) and 2023 (mass bleaching event). Taxonomic and functional richness (TRich, FRich) fluctuated throughout the study period, whereas functional divergence (FDiv) declined earlier (2016), highlighting site-specific differences. A trait-based nutrient-excretion proxy (NPC composite score) identified key species that maintain nutrient cycling. Despite recent coral bleaching, certain sites exhibited functional resilience, sustained by the persistence of high-performing nutrient providing species. However, the overall disconnect between taxonomic recovery and functional stability suggests that ecosystem-level processes remain vulnerable, even when species richness appears to recover. This highlights the importance of integrating functional traits and nutrient recycling proxies into monitoring programs to better predict long-term variability in San Andrés Island reefs under a changing climate. Our findings provide a framework for prioritizing management efforts in the Seaflower Biosphere Reserve with emphasis on maintaining ecosystem services. Full article

Dengue virus (DENV), an important mosquito-borne orthoflavivirus, represents a growing global threat due to its geographic expansion and recent outbreaks worldwide. In resource-limited endemic settings, the development of affordable diagnostic assays is needed. In this study, we developed and validated a colorimetric reverse transcription loop-mediated isothermal amplification assay (RT-LAMP) for the detection of DENV type 3 (DENV-3) using 95 previously diagnosed clinical samples from Southeastern Mexico. Primers targeting the 3′ untranslated region (3′ UTR) of DENV-3 were designed, and assay conditions were standardized. The colorimetric RT-LAMP DENV-3 system achieved a preliminary limit of detection of 1 × 10³ copies per reaction, with 90.7% sensitivity and 100% specificity. The colorimetric format enabled visual readout without specialized equipment, supporting its potential applicability in point-of-care and resource-limited settings. The developed colorimetric RT-LAMP detection for DENV-3 is intended as a rapid screening/triage tool that can trigger confirmatory testing or public-health actions. Full article

Cocoa pod husk (CPH), a major agro-industrial residue, contains valuable bioactive compounds whose recovery can support sustainable waste valorization. This study evaluated the influence of increasing ethanol concentrations on the ultrasound-assisted extraction (UAE) of bioactive compounds from CPH and their antioxidant, antihypertensive, and antihyperglycemic activity. Dried and milled CPH was extracted using ethanol–water mixtures (0–100% ethanol) under fixed ultrasonic conditions. Cocoa pod husk powder characterization and the resulting extracts were analyzed in terms of chemical composition (lignocellulosic compounds, proximate and elemental composition, and bromatological composition), antioxidant capacity, and in vivo antihypertensive and antihyperglycemic effects in Wistar rats. The results showed that solvent polarity strongly modulated extraction efficiency: absolute ethanol yielded the highest phenolic (171.43 mg GAE/g) and flavonoid (132.05 mg QE/g) content, whereas hydroalcoholic mixtures, particularly 50:50, enhanced overall antioxidant performance, especially in FRAP. The chemical analysis results showed the selective recovery of compounds such as quercetin, hesperidin, and theobromine, and FTIR-PCA results revealed distinct solvent-dependent chemical profiles. In vivo assays indicated modest blood pressure stabilization and a more pronounced antihyperglycemic effect after chronic administration. Overall, UAE proved an effective, rapid, and solvent-efficient method for CPH valorization, highlighting its potential for producing natural antioxidants applicable to food, nutraceutical, and cosmetic formulations. Full article

Cancer cells resort to metabolic reprogramming to sustain proliferation. Lung cancer has one of the highest mortality rates of all types of cancer. An important factor in its high mortality rate is its tumors’ ability to undergo significant metabolic reprogramming. Phytochemicals can counteract this altered metabolism and exhibit anticancer properties. Coleus hadiensis, a plant used in traditional medicine, has shown such potential. This study evaluated the in vitro cytotoxic activity of its methanolic extract and its effects on the metabolism of HTB-177 lung cancer cells. Qualitative and quantitative phytochemical analysis of this extract was performed to characterize its main constituents. Lung cancer cells were treated with different extract concentrations to evaluate their response to the extract. Cytotoxicity was determined using an MTT assay, and metabolites were analyzed through ¹H-NMR spectroscopy combined with multivariate statistical analysis. Transcriptomic profiling was also conducted to assess gene expression changes in metabolic pathways. Three main phenolic compounds were identified in the extract. The HPLC profile revealed peaks corresponding to gallic acid (GA), ferulic acid (FA), and rosmarinic acid (RA). The extract exhibited cytotoxic activity with an IC₅₀ of 192.85 µg/mL. Metabolic alterations were observed mainly in glycolysis, the Krebs cycle, and lipid metabolism—key pathways for tumor growth. Transcriptomic data revealed altered metabolism-related genes. The upregulation of ME1 correlated with the observed increase in pyruvate levels, while the downregulation of ALDH7A1 and ASRGL1 was linked to altered amino acid catabolism. Furthermore, transcriptomic data revealed the upregulation of the pro-apoptotic gene HRK. These results indicate that the methanolic extract of C. hadiensis possesses cytotoxic activity against lung cancer cells by modulating central metabolic routes and gene expression linked to cancer cell survival and proliferation. Full article

Secondary succession in tropical forests is traditionally described as a linear process driven by time since disturbance. However, growing evidence suggests that recovery pathways depend strongly on historical and environmental contexts. We evaluated how disturbance legacies and edaphic constraints interact to shape successional trajectories in a tropical karst landscape of the Maya Forest, Mexico. We sampled 100 plots along a chronosequence, quantifying vegetation structure, floristic diversity, biomass (NDVI), disturbance legacies, and soil properties. Using unsupervised clustering (K-means) and multivariate ordination, we identified four contrasting ecological typologies that represent distinct successional states rather than transient stages. Our results show a pronounced dichotomy in vegetation dynamics following the abandonment of land-use practices: while some sites are experiencing diverse development due to positive forest legacies (Typology B), others remain stalled (Typology C), dominated by lianas, where biotic barriers inhibit tree regeneration despite decades of abandonment. Additionally, we documented an asynchronous recovery between floristic recovery and vertical development; in sites with edaphic constraints, forests reach high diversity and biomass but exhibit stunted growth (Typology D). This suggests that severe abiotic constraints—specifically high rockiness and shallow soils—limit the dominance of highly competitive species, thereby acting as a filter that maintains high levels of diversity despite structural limitations. Edaphic analysis confirmed that chemical fertility and physical constraints (rockiness and shallow depth) act as orthogonal filters. This explains the persistence of structurally constrained yet functionally mature forests as stable, edaphically determined outcomes. Overall, secondary succession in tropical karst is nonlinear and path-dependent, governed by a hierarchical filtering model where historical land use dictates community identity and physical substrate limits structural architecture. These findings highlight the need for trajectory-specific management and the abandonment of uniform expectations of forest recovery in karst landscapes. Full article

Higher Education is facing a transformation of the teaching profession due to the confluence of active methodologies, learning management systems, and artificial intelligence. However, existing research tends to address these elements in isolation, lacking integrative analyses that examine their combined impact on the teaching role in higher education. Through a narrative review and thematic analysis of 49 articles, opportunities and challenges in this intersection are identified. The results indicate that the teacher is not merely a content transmitter but a designer of formative experiences, a critical guide, and an ethical reference in the use of AI. More than a replacement, technology proposes a teacher profile as an architect of critical and adaptive learning that combines pedagogy, technology, and ethics. Full article

Global energy demand relies heavily on fossil fuels, which produce greenhouse gas emissions. Additionally, municipal solid waste, driven by population growth, represents another source of emissions. In Mexico, organic waste contributes 61 million tons of CO₂eq annually due to inadequate disposal. In Mérida, Yucatan, over 231,000 tons of organic waste are generated yearly, including Urban Tree Pruning (UTP) from 760 public spaces—a significant, undervalued lignocellulosic resource. This study presents a comprehensive, year-round compositional characterization of Mérida’s UTP to establish its chemical profile and assess its seasonal stability as a precursor for bio-based products (i.e., bioethanol). Characterizing local and stable feedstocks, such as UTP, is a fundamental step to enabling Mexico’s compliance with biofuel policies like the 5.8% gasoline blend mandate (NOM-016-CRE) and the Alcohol-to-Jet strategy, supporting progress toward SDGs 7, 11, and 13. Based on a stratified random sampling, monthly analysis (May 2024–April 2025) revealed a consistent biochemical profile with mean annual contents of 23.32% lignin and 62.46% holocellulose. Statistical analysis (Tukey’s test) confirmed its structural homogeneity throughout the year. This uniformity is a key operational attribute, as it allows for the use of standardized industrial pretreatment parameters. Furthermore, the characterized composition supports a theoretical ethanol yield of 170 g/kg of dry biomass, a value competitive with traditional feedstocks like sugarcane bagasse. Consequently, Mérida’s UTP is characterized as a reliable and consistent biomass resource, supporting a transition from linear waste disposal to a circular bioeconomy model. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by excessive triglyceride accumulation in the liver, the presence of one or more cardiometabolic risk factors, and an absence of harmful alcohol intake. Oxidative stress plays a crucial role in the development and severity of this disease, contributing to an increased cardiovascular risk (CVR). Malondialdehyde (MDA), an oxidative biomarker resulting from lipid peroxidation, is closely associated with metabolic dysfunction. This study aimed to evaluate the role of MDA as a predictor of steatosis severity and CVR. Methodology: An observational cross-sectional study was conducted in a population with MASLD with hepatic steatosis confirmed by ultrasonography and computed tomography. Subjects were classified according to severity of the hepatic steatosis as grade I or grade II-III. Nutritional, anthropometric, and serum biochemical parameters were measured. MDA levels were determined using a spectrophotometric method. The CVR was assessed using waist-to-hip ratio (WHR), triglycerides-glucose (TyG) index, lipid accumulation product (LAP), and atherogenic index of plasma (AIP). Receiver operating characteristic (ROC) curve analysis was performed to identify MDA cut-off value, followed by multivariable logistic regression to assess its association with severity of steatosis adjusted for body fat percentage. Results: A total of 50 patients were included (21 men and 29 women). An MDA cut-off value ≥ 0.13 nmol/mL was associated with higher severity (grade II–III vs. grade I) (OR = 5.0; 95% CI: 1.20–20.0; p = 0.022). Higher WHR values were found in subjects with grade I (p = 0.049), and elevated TyG index values were observed in patients with grade I-III (p = 0.042) both indicating increased CVR. Conclusions: Elevated MDA levels and higher body fat percentage were associated with higher degree of hepatic steatosis and increased CVR in the population from southeastern Mexico. Full article

Parasitoids use different signals to locate their hosts, and these signals can modulate their behavioral decisions. Thus, patch selection and foraging in patches with different characteristics depend on their ability to gather and use such information efficiently. In this study, we evaluated whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae), a natural enemy of Trialeurodes vaporariorum (Hemiptera: Aleyrodidae) on tomato plants (Solanum lycopersicum), uses scent cues to select and forage in patches that differ in host density and predation risk. Using choice bioassays in a wind tunnel under a continuous airflow, we recorded selection patch and selection time, as well as foraging parameters, including residence time, oviposition events, and attacks. Our results show that E. eremicus discriminated between sites with and without hosts using scent cues, but discrimination between patches with different host numbers was not detected under our assay conditions. It also distinguished between patches with maximum risk and those without risk, but not between subtle differences in risk. These findings suggest that E. eremicus, responded mainly to contrasting olfactory cues rather than to subtle odor differences. From an applied standpoint, our results motivate deeper investigation into how host- and predator-associated olfactory cues could fine-tune parasitoid deployment in biological control. Full article