The growing presence of social media in children's everyday lives has intensified concerns about its relationship with mental health. This study examines how differentiated patterns of online media use are associated with suicidal ideation (SI) among Spanish children aged 10 to 15, incorporating direct cybervictimization (DCV) and age within a moderated mediation model. A nonexperimental, cross-sectional design was implemented using data from a nationally representative survey conducted in Spain (N = 804). Based on reported attitudes and uses of media and technology, three user profiles were identified through exploratory factor analysis: lurkers, characterized by predominantly passive consumption of online content; sharers, defined by the creation and public distribution of content; and interactors, whose activity centers on reciprocal exchanges with online contacts. The analysis confirmed differentiated associations across profiles. For sharers and interactors, the link with SI operated mainly through higher levels of DCV. Among lurkers, a direct association with SI was observed. Age exerted a limited moderating role within the model. Taken together, these findings underscore the importance of distinguishing between participation profiles and exposure to online aggression when examining SI in childhood, rather than relying solely on aggregate measures of social media use.
Coal is a major global energy resource, but its extraction raises significant environmental and health concerns. Mining activities release large amounts of particulate matter, including nanoparticles (NPs), into the environment. These NPs are hazardous due to their content of polycyclic aromatic hydrocarbons (PAHs), metals, oxides, and other compounds capable of disrupting cellular and molecular processes. This study evaluated the cytotoxic and genotoxic effects of coal-derived NPs on V79 and HaCaT cell lines, focusing on their impact on DNA stability and the mechanisms responsible for cellular damage. NPs were isolated using an acid-based separation method and applied to cells at concentrations of 50, 150, and 300 μg/mL. Atomic force microscopy (AFM) provided topographical characterization, while dynamic light scattering (DLS) confirmed their tendency to agglomerate. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDS) confirmed NP morphology and elemental composition, including carbon, oxygen, iron, calcium, silicon, aluminum, and copper. Cytotoxicity was assessed using resazurin and sulforhodamine B assays, and genotoxicity was evaluated using the comet assay, micronucleus test, and γH2AX immunostaining. Results showed a clear dose-dependent effect, with coal NPs inducing genomic instability and increased cell mortality, mainly through apoptosis. These findings highlight the importance of characterizing coal-derived NPs to better assess their environmental and health risks, particularly regarding respiratory diseases.
Non-linear dynamics is probably much more common in the epigenetic dynamics of living beings than hitherto recognized. Here we report a case of global bifurcation triggered by gender that affects higher cognitive functions in humans. We report a cross-cultural study showing deviations in time perception, as assessed by estimating the duration of brief sounds, according to their durations and to the gender of the perciver. Results show that the duration of sounds lasting less than 10 s were on average overestimated, whereas those lasting longer were underestimated; estimates of sounds shorter than 1 s were extremely inaccurate. Females consistently gave longer estimates than males. Accuracy in time estimation was correlated to academic performance in disciplines requiring mathematical or scientific skills in male, but not in female students. This difference in correlation however had nothing to do with overall skills in mathematics. Both sexes scored similarly in scientific and technical disciplines, but females had higher grades than males in languages and lower ones in physical education. Our results confirm existing evidence for gender differences in cognitive processing, hinting to the existence of different "mathematical intelligences" with different non-linear relationships between natural or biological mathematical intuition and time perception.
La diarrea inducida con lactosa en ratas ha servido para estudiar la alimentación durante la diarrea. Sin embargo, las ratas se adaptan al consumo de lactosa por lo que la diarrea dura aproximadamente una semana. Para establecer si la remoción del ciego podría prolongarla, aquí se comparó esta diarrea en ratas intactas y cecotomizadas. El experimento incluyó 16 ratas intactas y 16 cecotomizadas. A la mitad de las ratas en cada grupo se les ofreció una dieta con 45% de lactosa (grupo diarrea) y a la otra mitad una dieta sin lactosa (grupo control). El experimento duró 21 días con 3 recolecciones de heces de 48 h (días 2-4, 9-11 y 17-19). Los resultados mostraron que durante la primera recolección hubo diarreas similares tanto en los grupos de ratas intactas como cecotomizadas, pero en las próximas, sólo las cecotomizadas tenían una diarrea cuya severidad aumentó (3,5 veces) con el tiempo. Adicionalmente, en los dos tipos de ratas, las pérdidas fecales de proteína y grasa fueron proporcionales a la masa fecal húmeda excretada, pero fueron 2 veces más altas en las cecotomizadas. Se concluye que la cecotomía previene la adaptación, aumenta la severidad y prolonga la diarrea inducida con lactosa e incrementa notablemente las pérdidas fecales de los macronutrientes y reduce la eficiencia del alimento.
Groundwater contamination is difficult to characterize at sites where hydrogeochemical information is derived from sparse monitoring-well networks. This study presents a framework that integrates groundwater-quality records with electrical resistivity and Induced Polarization (IP) data to better understand landfill-derived leachate plume behavior. The methodological approach is applied to an upper aquifer downgradient of a bark dump and its contamination attenuation zone, where pollution is linked to ongoing health issues in an adjacent Canadian Indigenous community. Stacked Pollution Indices (SPI) are evaluated alongside unsupervised machine-learning methods (i.e., Gaussian Mixture Models, GMM; Hierarchical Agglomerative Clustering, HAC; and Self-Organizing Maps combined with K-means, SOM + K-means) to integrate and classify hydrogeochemical variables into contamination-related facies. Ordinary kriging is used to interpolate these variables between monitoring wells, generating a synthetic dataset for SOM training and improving spatial coverage across the site. Overlap in SPI ranges across GMM, HAC, and SOM + K-means clusters indicates that aggregated pollution metrics may mask intrinsic relationships among water-quality variables. Comparing 7-m depth slices through resistivity and IP cubes, corresponding to the monitoring-well screening interval in the upper aquifer, with maps of electrical conductivity, SPI, and SOM-derived facies yields a more coherent interpretation of plume geometry, migration fronts, and compositional heterogeneity than either information source could provide independently. By integrating unsupervised hydrogeochemical clustering with geoelectrical imaging, this study establishes a refined hydrogeochemical–geophysical facies zonation of the upper aquifer and leachate plume, offering a practical basis for environmental monitoring, risk assessment, and remediation planning in contaminated systems constrained by limited resources and sparse sampling. ML-based hydrogeochemical facies mapping refines geoelectrical interpretation. ML-based hydrogeochemical facies mapping reveals contamination zones missed by pollution indices. Geostatistical methods give reliable proxy inputs for ML mapping in data-poor regions. Combined hydrogeochemical-geophysical visuals empower community-led monitoring.
