Instituto Oceanográfico de la Armada del Ecuador

Biogenic sterols were analyzed in surface sediments and suspended particulate matter (SPM) from the three inlets of Admiralty Bay, Antarctica, to investigate the spatial distribution, sources, and degradation patterns of organic matter (OM) and to provide comparative insights into sterol composition and behavior across environmental compartments. Total sterol concentrations ranged from 0.28 to 8.10μgg-1 in sediments and from 5.34 to 306.88μgg-1 in SPM. Marine sterols, particularly brassicasterol, dominated SPM, reflecting fresh phytoplankton-derived OM, whereas sediments contained more degraded material with contributions from both marine and terrestrial sources (β-sitosterol, stigmasterol). Sedimentary sterols positively correlated with %TOC, %TN, and fine particle fractions, while sterols in SPM negatively correlated with SPM concentration, indicating dilution by inorganic and resuspended particles. Differential SPM/sediment ratios revealed selective preservation and transport of sterols, with higher degradation rates in the water column accounting for lower sedimentary concentrations. These findings highlight the integrated influence of hydrodynamics, primary productivity, and sedimentary characteristics on the distribution, composition, and preservation of OM in Antarctic coastal ecosystems.

Biodiversity monitoring programs need to deliver accurate, timely, and actionable predictions. To establish a predictive monitoring program for deep-sea benthos of the Santos Basin, Brazil, we developed a two-stage structured model that allowed comparison of biodiversity predictions obtained from environmental simulations (2M-Sim). We also modeled the environmental variables as a function of spatial and temporal variables and compared this model's predictions with predictions obtained from real environmental data (2M). We built unstructured models (1M) as references to evaluate whether the proposed structured approach was reliable. We expected no significant differences between 1M and 2M or between 2M and 2M-Sim. Data were obtained from 100 stations at depths of 25-2400m during two surveys (2019 and 2021). In our model framework, we used 12 benthic macro- and meiofaunal variables, 44 sediment and water column environmental variables, and four spatial and temporal variables. We applied a random forest algorithm to the structured and unstructured models. All comparisons were performed with 20% of the dataset set aside for validation. The average accuracy was 72%, 69%, and 68% for the 1M, 2M, and 2M-Sim models, respectively. Accuracies of 2M ranged from 38% to 84% and were generally higher for macrofauna. The observed accuracy loss from 1M to 2M (3%) and from 2M to 2M-Sim (1%) was not significant for any biodiversity variable. The 2M model identified 30 significant environmental variables; bottom water parameters and sedimentary phytopigment and carbonate concentrations were the best predictors. Our approach supports biodiversity conservation by optimizing data needs and future sampling and by guiding data-driven management decisions for benthic biodiversity.

The Tubarão River-estuarine system (TRES), located in the South Atlantic, Brazil, is essential for water supply, agriculture, fisheries, and industrial activities. It has historically been affected by coal extraction, urbanisation, and industrial discharges, activities that generate significant impacts on ecosystem health, such as decreased water quality, habitat degradation, and potential bioaccumulation of toxic compounds in aquatic organisms. Nineteen sediment samples were collected along the TRES to assess contamination levels and evaluate the sources and spatial distribution of pollution. The study encompassed both aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs). Total AH concentrations ranged from 3.86 to 69.4μgg-1 (mean: 25.7±20.7μgg-1), with ΣC10-C40n-alkanes accounting for 0.34-12.0μgg-1 (mean: 4.65±4.07μgg-1). PAH levels were between 6.42 and 6440.2ngg-1 (mean: 1370.7±1654.6ngg-1 for Σ27PAHs, excluding retene and perylene) and 3.47 to 1540.8ngg-1 (mean: 323.4±385.5ngg-1) for Σ16PAHs. The TRES is strongly influenced by anthropogenic hydrocarbons, with the most prominent contamination observed in the upper reaches of the river and the Rocinha River tributary. The middle section of the system is moderately affected, likely due to dilution by tributary inputs, while the lower reaches experience consistent pollution from urban and industrial activities. Contamination pattern is potentially influenced by fine coal particles and sorbent nanoparticles derived from mining and other coal-related activities. In this context, these particles may also influence source apportionment analyses, which revealed mixed petrogenic- and pyrogenic-like signatures, consistent with the geochemical characteristics of coal-derived PAHs in coal-influenced systems. These data are crucial for monitoring long-term pollution trends, as environmental conditions and contamination levels typically change gradually, offering valuable insights for future assessments and regional policy development.

Does dispersal differ between the sexes? This question, anchored in a body of rich theoretical literature, has received little empirical attention in marine invertebrates. Yet, dispersal is a key ecological process with profound implications for speci

INTRODUCCION: Úlcera péptica, es la denominación de la enfermedad ulcerosa confinada al estómago y al duodeno, resultante del daño de la mucosa, por el desequilibrio de, los factores protectores (riego sanguíneo, secreción de bicarbonato de la mucosa, uniones intercelulares estrechas de la mucosa, recambio epitelial) y factores dañinos (infección por H. Pylori, alcohol, tabaco, estado de choque, AINES, esteroides, desnutrición e inmunosupresión). Si el proceso continúa, la úlcera se profundiza y perfora la capa serosa, permitiendo que, el contenido gástrico se libere a la cavidad abdominal. OBJETIVO: Describir el manejo actual para la úlcera gastroduodenal perforada. METODOS: Se realizó una búsqueda sistemática con la guía de la declaración PRISMA 2020, se elaboraron criterios de inclusión y exclusión sobre el tema de investigación. Se recopilaron, 37 artículos medico científicos obtenidos de bases de datos como Pubmed, ELSEVIER, directrices de la Guía basada en evidencia sobre el manejo actual de la úlcera gastroduodenal perforada. Fecha en la que cada recurso se buscó o consultó por última vez 05/08/2024. RESULTADOS: La resolución de la úlcera gástrica/duodenal perforada es, mediante tratamiento quirúrgico con parche de distintos tipos, el más utilizado es el parche omental, parche de Graham con el que, se obtienen buenos resultados. El estado clínico y la enfermedad dictan cual procedimiento quirúrgico debe elegirse para el abordaje, pudiendo realizarse: exéresis de la úlcera, resección duodenal, sutura del muñón duodenal, resección de la primera porción del duodeno, gastrectomía remanente y parche omental sobre la sutura. La cirugía abierta se recomienda en: paciente inestable con perforación y sangrado simultáneo. CONCLUSIONES: La úlcera gástrica y duodenal perforada, es una emergencia quirúrgica de tratamiento complejo y requiere atención temprana en el area de emergencias, donde se valora el estado clínico del paciente, el tamaño de la úlcera y de acuerdo a esto, se elige el tratamiento optimo, ya sea con parche o resección, por cirugía laparoscópica o abierta, además de requerir un manejo multidisciplinario con equipos de gastroenterología para endoscopía y colocación de stent, ingreso en unidad de cuidados intensivos cuando el paciente se encuentra inestable, imagenología intervencionista y ginecología en casos especiales.

El estudio actual se centra en el uso de la metodología activa y el uso de la neuroeducación en la escuela primaria con el objetivo de evaluar su impacto en el desarrollo cognitivo y emocional de los estudiantes. Al introducir programas educativos que integren estrategias como el aprendizaje basado en proyectos (ABP) y la neurociencia, tratamos de mejorar las habilidades críticas y creativas de los estudiantes, así como mejorar sus logros académicos en diferentes campos. Los resultados muestran que el uso de estos métodos no solo contribuye al aprendizaje teórico, sino que también contribuye al medio ambiente de inclusive y motivación, lo que promueve una educación más justa y personal. Este enfoque, basado en activar varias funciones cerebrales, permite una mayor adaptación a los desafíos educativos actuales, brindando a los estudiantes herramientas para abordar problemas tanto dentro como fuera del aula.

The contamination of soil, water, and air by potentially toxic elements (PTEs) allows the transfer of metals to food. When introduced into food through soil, PTEs are absorbed by plant roots and transported to the bloodstream. The region surrounding Sepetiba Bay (SB), a densely populated area intensively exploited for tourist purposes, is one of the most contaminated by PTEs in the southeastern region of Brazil. Therefore, this study aims to evaluate (by ICP-MS) the concentrations of PTEs in agricultural products (roots, fruits, leaves, seeds, cheese, and eggs) cultivated and sold by rural producers in the region surrounding SB. The 26 food types selected for this study were produced in this region and purchased at local markets. The results for the analyzed foods revealed relatively high concentrations of Zn > Cu > Ni > Cr > As > Pb > Co > Hg > Cd, exceeding the limits established by ANVISA and international laws. Cluster analysis (CA) and principal component analysis (PCA) grouped the PTEs according to their possible sources: ore transport (Zn, Cu, Pb, and Cd), natural (Hg, Cr, and Ni), and fertilizers (Co and As). The CA allowed us to distinguish two main food groups in terms of the enrichment of PTEs. Group 1 contains leaves, animal products, and seeds with higher levels of Hg, Cr, Ni, Co, and As. Group 2 includes roots and fruits, which have higher concentrations of Zn, Cu, Pb, and Cd than Group 1. The Hazard Quotient (HQ) suggests that As and Cr pose a higher risk in foods of CA-Group 1 (leaves, animal products, and seeds). Hazard Index (HI) values > 1 indicate a risk of probable long-term carcinogenesis in adults. Thus, this study reveals that the continued consumption of food produced in the region surrounding SB could cause health problems for the local population.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00244-025-01143-8.