Universidad de Magallanes
Not a member yet
1947 research outputs found
Sort by
Curcumin Improves Hippocampal Cell Bioenergetics, Redox and Inflammatory Markers, and Synaptic Proteins, Regulating Mitochondrial Calcium Homeostasis
No full textMitochondria produces energy through oxidative phosphorylation (OXPHOS), maintaining calcium homeostasis, survival/death cell signaling mechanisms, and redox balance. These mitochondrial functions are especially critical for neurons. The hippocampus is crucial for memory formation in the brain, which is a process with high mitochondrial function demand. Loss of hippocampal function in aging is related to neuronal damage, where mitochondrial impairment is critical. Synaptic and mitochondrial dysfunction are early events in aging; both are regulated reciprocally and contribute to age-associated memory loss together. We previously showed that prolonged treatment with Curcumin or Mitoquinone (MitoQ) improves mitochondrial functions in aged mice, exerting similar neuroprotective effects. Curcumin has been described as an anti-inflammatory and antioxidant compound, and MitoQ is a potent antioxidant directly targeting mitochondria; however, whether Curcumin exerts a direct impact on the mitochondria is unclear. In this work, we study whether Curcumin could have a mechanism similar to MitoQ targeting the mitochondria. We utilized hippocampal slices of 4-6-month-old C57BL6 mice to assess the cellular changes induced by acute Curcumin treatment ex-vivo compared to MitoQ. Our results strongly suggest that both compounds improve the synaptic structure, oxidative state, and energy production in the hippocampus. Nevertheless, Curcumin and MitoQ modify mitochondrial function differently; MitoQ improves the mitochondrial bioenergetics state, reducing ROS production and increasing ATP generation. In contrast, Curcumin reduces mitochondrial calcium levels and prevents calcium overload related to mitochondrial swelling. Thus, Curcumin is described as a new regulator of mitochondrial calcium homeostasis and could be used in pathological events involving calcium deregulation and excitotoxicity, such as aging and neurodegenerative diseases
Best Practices for Machine Learning-Assisted Protein Engineering
No full textData-driven modeling based on machine learning (ML) is becoming a central component of protein engineering workflows. This perspective presents the elements necessary to develop effective, reliable, and reproducible ML models, and a set of guidelines for ML developments for protein engineering. This includes a critical discussion of software engineering good practices for the development and evaluation of ML-based protein engineering projects, emphasizing supervised learning. These guidelines cover all of the necessary steps for ML development, from data acquisition to model deployment. Additionally, the present perspective provides practical resources for the implementation of the outlined guidelines. These recommendations are also intended to support editors and scientific journals in enforcing good practices in ML-based protein engineering publications, promoting high standards across the community. With this, the aim is to further contribute to improved ML transparency and credibility by easing the adoption of software engineering best practices into ML development for protein engineering. We envision that the wide adoption and continuous update of best practices will encourage informed use of ML on real-world problems related to protein engineering
Unraveling Wing Shape Variation in Malaria Mosquitoes from the Arctic Edge: A Geometric Morphometric Study in Western Siberia
No full textSimple Summary In Western Siberia, the Anopheles maculipennis subgroup includes three malaria vectors An. messeae, An. daciae, and An. beklemishevi, and their hybrids, which are difficult to tell apart using traditional traits such as egg exochorion. We combined molecular identification with geometric morphometrics of wing venation to evaluate differences in wing shape and size among species. We found statistically significant differences in wing shape and centroid size, with hybrids showing intermediate morphology and overlap with their parental species. Landmarks on the radial and medial veins contributed most to species separation. We did not evaluate environmental adaptation, and wing shape differences were not explained by size. These findings support the use of wing morphometrics, together with genetic data, to improve species delimitation and surveillance of malaria vectors in temperate regions.Abstract In Russia, Western Siberia, Anopheles from maculipennis subgroup comprises three vector species: An. messeae, An. daciae, An. beklemishevi, and the hybrid between An. messeae and An. daciae (Anopheles m-d), which exhibit complex cryptic morphological traits. Traditional morphological methods, such as egg morphology and exochorion coloration, have proven insufficient for reliably distinguishing these closely related species due to overlapping characteristics and high intra-species variability. To overcome these limitations, geometric morphometrics (GM) has emerged as a powerful tool for analyzing cryptic morphology. This article focuses on wing venation patterns, where GM provides precise, quantitative data based on defined anatomical landmarks, enabling detailed assessment of size and shape variation among species. Procrustes ANOVA, principal component analysis (PCA), and canonical variate analysis (CVA) were employed to assess shape variation and species differentiation. Centroid size and its relationship to shape variation were examined using multivariate regression. Despite significant morphological differences, the overlap observed in hybrids (An. m-d) reflects their intermediate position between the parental species. Our analyses revealed significant differences in wing shape and size among An. messeae, An. daciae, An. beklemishevi, and their hybrids, with hybrids showing intermediate morphologies. Landmarks on radial and medial veins were the most consistent contributors to species separation. No evidence of static allometry was detected, and wing shape differences were not explained by size. These findings demonstrate that wing morphometrics, combined with molecular identification, provides a reliable framework for species delimitation and surveillance of malaria vectors in temperate regions
The occupation of canoe and european creole groups in colonial and republican times in the Taitao Peninsula/Gulf of Penas (~46°-48°S), Western Patagonia, Chile
No full textResumen: Se presentan los resultados de las prospecciones arqueológicas realizadas en las áreas costeras insulares y continentales al sur de península de Taitao y golfo de Penas (~46°-48°S) en la región de Aysén, Patagonia occidental. En ellas se reveló una importante evidencia de registros materiales de tiempos coloniales y republicanos producto de actividades originadas tanto por grupos canoeros (cazadores-recolectores- pescadores marinos) como por europeo/criollos, en momentos en que se desarticulan y transforman los modos de vida de los primeros luego del contacto europeo en el siglo XVI. Esta extensa área comenzó a ser visitada y ocupada bajo nuevos términos geopolíticos, económicos- extractivistas y estratégicos, reconfigurando aquel espacio. A través del registro cronológico y material de 17 sitios arqueológicos, discutimos variables como la diversidad de sitios representados, la subsistencia, dieta y cronologías de ocupación en relación al uso del borde costero durante tiempos históricos en este espacio archipelágico
Technical note: In situ photosynthesis-irradiance curve determination in peatlands with a modulated-light skirt-chamber
No full textPeatlands play a crucial role in the global carbon cycle, and among several key processes, it is essential to characterize photosynthesis-irradiance (PI) curves, which describe the relationship between light availability and carbon assimilation through photosynthetic activity. Traditional approaches such as eddy covariance, portable photosynthesis systems, and chambers provide valuable data at ecosystem, leaf, and mesoscales, respectively. Chamber-based measurements are particularly useful at intermediate scales, as they capture photosynthetic activity of whole plant assemblages while integrating microhabitat and belowground processes. However, conventional chambers typically require the installation of collars, involving cutting and trenching of vegetation that may alter fluxes; this often necessitates a delay period before reliable measurements can begin and reduces the portability and applicability of chamber methods in remote peatlands. In a previous companion study, we introduced the skirt-chamber, a minimally invasive method for greenhouse gas flux measurements. Building on that design, we developed a modulated-light skirt-chamber specifically for PI curve determination. This chamber enables in situ characterization of photosynthetic responses under natural light conditions using adjustable shading screens, while preserving portability and minimizing disturbance. Field tests in a subantarctic Sphagnum bog demonstrated that the generated PI curves fit established models and closely matched eddy covariance measurements. The modulated-light skirt-chamber therefore provides a cost-effective and flexible tool for studying carbon dynamics in low-stature peatland ecosystems, with promising applications in heterogeneous landscapes
FIRST RECORD OF ROCK ENGRAVINGS IN MAGALLANES: SIERRA BAGUALES LOCALITY, PATAGONIA, CHILE
No full textSe presenta la primera evidencia de grabados rupestres en la región de Magallanes, registrados específicamente en la localidad de Sierra Baguales. Estos consisten en dos motivos no figurativos sobre sustrato rocoso a orillas del río Baguales: uno geométrico circular y un motivo tridígito continuo y un fragmento de bloque aislado con motivo figurativo antropomorfo registrado próximo a Villa Cerro Guido. La comunicación aquí representada es netamente descriptiva, informando acerca de los detalles del hallazgo y su contexto, destacando de esta manera la importancia del descubrimiento de la expresión artística para la arqueología de la región Patagónica
Shallow benthic invertebrate communities in relation to substrate types in coastal environments of the sub-Antarctic Crozet archipelago
No full textCoastal ecosystems of sub-Antarctic islands are threatened by increasing climate-driven changes and direct anthropogenic pressures. Significant effects on marine communities are expected, but benthic ecosystems of these isolated islands remain largely under-explored. Effective preservation of these nearshore environments requires deeper ecological assessments and comprehensive biodiversity knowledge. In this regard, this study reports findings from a survey carried out in 2021 at two sites - Baie du Marin and Crique du Sphinx - located on the eastern coast of Ile de la Possession (sub-Antarctic Crozet archipelago, Southern Ocean). We investigated the composition and structure of nearshore benthic faunal communities using a quantitative fieldwork protocol and an integrative molecular- and morphology-based taxonomic approach. A total of 124 morphotypes were identified, including a high proportion (72%) of rare species. Both sites exhibited similar benthic invertebrate communities. Structurally complex habitats such as hard substrates or areas dominated by macroalgae exhibited higher species richness and diversity. The investigated benthic invertebrate communities are typical of the sub-Antarctic area but featured unique structures, including dense tube-dwelling polychaete colonies. This study will provide a baseline for future monitoring programs and for the preservation of sub-Antarctic coastal benthic ecosystems
Genome-wide association study of long COVID
No full textInfections can lead to persistent symptoms and diseases such as shingles after varicella zoster or rheumatic fever after streptococcal infections. Similarly, severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) infection can result in long coronavirus disease (COVID), typically manifesting as fatigue, pulmonary symptoms and cognitive dysfunction. The biological mechanisms behind long COVID remain unclear. We performed a genome-wide association study for long COVID including up to 6,450 long COVID cases and 1,093,995 population controls from 24 studies across 16 countries. We discovered an association of FOXP4 with long COVID, independent of its previously identified association with severe COVID-19. The signal was replicated in 9,500 long COVID cases and 798,835 population controls. Given the transcription factor FOXP4's role in lung physiology and pathology, our findings highlight the importance of lung function in the pathophysiology of long COVID
Analysis of vibration due to combined misalignments in loaded spur gear systems
No full textThis study investigates a single stage spur gear transmission system subjected to combined misalignments, such as parallel (radial and axial) and angular (yaw) misalignments, under varying load conditions. Two load levels were analysed: 0.1 Nm for "no load" and 1.2 Nm for "loaded" conditions. The input variables are combined misalignments and reaction loads, while the output variable is the vibration measurement taken at the bearing supports. These measurements were used to assess the effect of misalignment and load on the vibrational behaviour of the system. The test bench used for the experimental runs consists of a 2 hp motor and a hydraulic system that allows the reaction torques to be controlled. The results show that although the acceleration values vary under different load conditions, the overall trend remains consistent as long as no significant deformation occurs in the gears. Furthermore, the type of misalignment that most influences the variation in acceleration is yaw misalignment