Universidad de Magallanes
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Extreme fire weather in Chile driven by climate change and El Niño-Southern Oscillation (ENSO)
No full textA string of fierce fires broke out in Chile in the austral summer 2023, just six years after the record-breaking 2017 fire season. Favored by extreme weather conditions, fire activity has dramatically risen in recent years in this Andean country. A total of 1.7 million ha. burned during the last decade, tripling figures of the prior decade. Six of the seven most destructive fire seasons on record occurred since 2014. Here, we analyze the progression during the last two decades of the weather conditions associated with increased fire risk in Central Chile (30 degrees-39 degrees S). Fire weather conditions (including high temperatures, low humidity, dryness, and strong winds) increase the potential for wildfires, once ignited, to rapidly spread. We show that the concurrence of El Nino and climate-fueled droughts and heatwaves boost the local fire risk and have decisively contributed to the intense fire activity recently seen in Central Chile. Our results also suggest that the tropical eastern Pacific Ocean variability modulates the seasonal fire weather in the country, driving in turn the interannual fire activity. The signature of the warm anomalies in the Nino 1 + 2 region (0 degrees-10 degrees S, 90 degrees W-80 degrees W) is apparent on the burned area records seen in Central Chile in 2017 and 2023
Vegetation and environmental responses from extreme glacial to extreme interglacial conditions in central Isla Grande de Chiloé (∼42°S), northwestern Patagonia
No full textWe examine the vegetation and environmental evolution of central Isla Grande de Chiloé (IGC), northwestern Patagonia (NWP), spanning the two climatic endmembers of the last glacial-interglacial cycle: the Last Glacial Maximum (LGM) and the Early Holocene (EH). Our results from Lago Auquilda show Evergreen Subantarctic forests interspersed with Magellanic Moorland during the early LGM (similar to 30.9-26.1 ka), followed by species-poor closed-canopy Nothofagus forests with low conifer abundance and absence of Magellanic Moorland during the late LGM (similar to 18.9-17.9 ka). Initial canopy fragmentation at similar to 17.9 ka gave way to rapid densification and diversification of trees, herbs, and vines characteristic of North Patagonian rainforests (NPRF), marking the onset of the Last Glacial Termination (T1). Closed-canopy NPRF established between similar to 15.5-14.8 ka, followed by mixed forests with shade- and cold-tolerant hygrophilous NPRF conifers until abrupt increases in shade-intolerant trees favored by local fires between similar to 12.6-11.4 ka. NPRF conifers disappeared as thermophilous species of the Valdivian rainforest and fire activity increased between similar to 11.4-8.7 ka. We interpret that temperate rainforest inhabited the periphery of the Patagonian Ice Sheet in NWP under cold and hyperhumid conditions during the LGM. Precipitation was highest in the early LGM, declined during the late LGM, diminished to an early T1 minimum between similar to 17.1-16.4 ka, and then increased steadily to a maximum between similar to 14.8-12.6 ka, overlapping with the Antarctic Cold Reversal (ACR). Subsequent declines at similar to 12.6 ka and similar to 11.4 ka led to extreme warm-dry conditions during the EH with intense fire activity. Hyperhumid conditions during the LGM and ACR imply equatorward-shifted Southern Westerly Winds (SWW), minimum precipitation during the early portion of T1 relates to poleward-shifted SWW, and the EH warm-dry phase reflects a zonally symmetric decline in SWW intensity. Our Lago Auquilda record replicates the timing and structure of changes revealed by multiple paleoclimate studies throughout western Patagonia which, in turn, are synchronous/coherent with key southern mid- and high-latitude records
Functional traits and ecosystem implications in the Multiple Use Marine Protected Area Almirantazgo Sound: A baseline study of scallop banks and benthic communities
No full textAmid escalating environmental challenges confronting marine ecosystems, the proliferation of coastal and marine protected areas (MPAs) has emerged as a pivotal strategy for mitigating biodiversity loss and fostering sustainable resource management. This research advocates for a paradigm shift towards a trait-based approach to assess functional diversity (FD) within MPAs, with a specific focus on the ecologically crucial Austrochlamys natans banks in Parry Bay, MPA Almirantazgo Sound. By surveying 28 invertebrate species across eight phyla, a PCA using fuzzy-coded functional traits revealed five distinct groupings primarily based on feeding, movement, and reproductive modes. Mobile predators and scavengers clustered distinctly from sessile suspension feeders and limited-mobility grazers, indicating a scarcity of mobile predator species in Parry Bay, which impacts the ecosystem's dynamics. FD indices highlighted low functional alpha-diversity, emphasizing trait redundancy that enhances resilience but relies heavily on a few unique and specialized species. The potential extinction or migration of these species could directly affect unique ecosystem properties. While revealing the resilience of the benthic community, this research underscores its dependence on a handful of species that are crucial for both ecological functions and regional commercial significance. Urgent conservation and management measures are imperative to protect these species and maintain the delicate balance of this ecosystem
Exposure to nanoplastics and nanomaterials either single and combined affects the gill-associated microbiome of the Antarctic soft-shelled clam Laternula elliptica
No full textNanoplastics and engineering nanomaterials (ENMs) are contaminants of emerging concern (CECs), increasingly being detected in the marine environment and recognized as a potential threat for marine biota at the global level including in polar areas. Few studies have assessed the impact of these anthropogenic nanoparticles in the microbiome of marine invertebrates, however combined exposure resembling natural scenarios has been overlooked. The present study aimed to evaluate the single and combined effects of polystyrene nanoparticles (PS NP) as proxy for nanoplastics and nanoscale titanium dioxide (nano-TiO2) on the prokaryotic communities associated with the gill tissue of the Antarctic soft-shell clam Laternula elliptica, a keystone species of marine benthos Wildcaught specimens were exposed to two environmentally relevant concentrations of carboxylated PS NP (PS-COOH NP, -62 nm size) and nano-TiO2 (Aeroxide P25, -25 nm) as 5 and 50 mu g/L either single and combined for 96h in a semi-static condition.Our findings show a shift in microbiome composition in gills of softshell clams exposed to PS NP and nano-TiO2 either alone and in combination with a decrease in the relative abundance of OTU1 (Spirochaetaceae). In addition, an increase of gammaproteobacterial OTUs affiliated to MBAE14 and Methylophagaceae (involved in ammonia denitrification and associated with low-quality water), and the OTU Colwellia rossensis (previously recorded in polluted waters) was observed. Our results suggest that nanoplastics and nano-TiO2 alone and in combination induce alterations in microbiome composition by promoting the increase of negative taxa over beneficial ones in the gills of the Antarctic soft-shell clam. An increase of two low abundance OTUs in PS-COOH NPs exposed clams was also observed. A predicted gene function analysis revealed that sugar, lipid, protein and DNA metabolism were the main functions affected by either PSCOOH NP and nano-TiO2 exposure. The molecular functions involved in the altered affiliated OTUs are novel for nano-CEC exposures
Multidisciplinary Home-Based Rehabilitation Program for Individuals With Disabilities: Longitudinal Observational Study
No full textBackground: Disability affects a significant portion of the global population nowadays, necessitating innovative approaches to access rehabilitation processes. Home-based rehabilitation has emerged as a beneficial approach, offering comfort and context-specific therapy. Objective: This study aims to evaluate the impact of a multidisciplinary home-based rehabilitation program for individuals with moderate neuromusculoskeletal disabilities in terms of motor function and mood. Methods: A total of 270 participants with median age of 66 (IQR 20-98) years were recruited from the National Disability Registry of Chile. The intervention involved a multidisciplinary team composed of 49 health care professionals providing personalized treatment plans over 4 months (32 sessions for physical therapy, 8 sessions for occupational therapy, 4 sessions for nutrition, 8 sessions for psychology, and 4 sessions for nursing and podiatry). This program also included 2 medical evaluations (at the beginning and the end) to monitor clinical progress in terms of motor function and mental health, using the Berg Balance Scale and Beck Depression Inventory, respectively. Results: The home-based rehabilitation program showed significant improvements (P<.001) in motor function and balance with a reduction in fall risk. Specifically, the Berg Balance Scale score decreased close to 15% after the home-based rehabilitation program for all enrolled participants. On the other hand, depression levels showed no significant changes (P=.27), with percentages of variation less than 8% between the 2 assessed conditions. In this sense, participants remained with the same mild depression level (14 of 63) concerning the Beck Depression Inventory score. Conclusions: This study concludes that personalized home-based rehabilitation programs are effective in enhancing motor function and balance, particularly in individuals with neurological conditions. On the other hand, the findings in terms of mood advocate for further exploration of psychological support within such programs to enhance overall patient well-being
Factors influencing teaching choice as predictors of Teacher Identity in prospective Special Education teachers
No full textTeacher identity has been studied as a broad construct, mutable and influenced by multiple factors during its development. Few investigations have addressed the factors that could explain teacher identity during Special Education teacher education. The objective was to establish the explanatory capacity of motivational and perceptual factors for career choice on teacher identity. A quantitative approach with an explanatory cross-sectional design was used. 180 Special Education preservice teachers from 10 Chilean universities participated in the study. The FitChoice Scale and Teacher Identity Measurement Scale were used. The data were analysed with Bayesian linear regression. The results show that perception factors alone explain 32% of the behaviour of teaching identity. Meanwhile, the joint model between motivation factors, perception factors for career choice, and sociodemographic variables such as family income and having a teaching family member shows a greater explanatory capacity concerning teaching identity (38%). It is hoped that the results of this research constitute an approximation to the explanation of the factors that influence the development of teaching identity in future Special Education teachers
Computing the coarseness measure of a bicolored point set over guillotine partitions
No full textThe coarseness of a set of points in the plane colored red and blue is a measure of how well the points are mixed together. It has appealing theoretical properties, including a connection to the set of points tendency to accept a good clustering partition. Yet, it is computationally expensive to compute exactly. In this paper, the notion of computing the coarseness using a guillotine partition approach is introduced, and efficient algorithms for computing this guillotine coarseness are presented: a top-down approach and a dynamic programming approach, both of them achieving polynomial time and space complexities. Finally, an even faster O ( n 2 log 2 n) polynomial-time algorithm to compute a reduced version of the measurement named two- level guillotine coarseness is presented using geometric data structures for faster computations. These restrictions establish lower bounds for the general guillotine coarseness that allow the development of more efficient algorithms for computing it
Detection of human enteric viral genes in a non-native winter crane fly, Trichocera maculipennis (Diptera) in the sewage treatment facilities at Antarctic stations
No full textBackgroundThe Antarctic environment is susceptible to the introduction of non-native species due to its unique ecosystem, which has evolved under geographical isolation and extreme climatic conditions over an extended period. The recent introduction of the non-native winter crane fly, Trichocera maculipennis, to maritime Antarctica may pose a potential threat to the Antarctic ecosystem. In this study, we evaluated the possibility of the mechanical transmission of viruses by T. maculipennis.MethodsWe assessed the potential for the mechanical transmission of viruses using next-generation sequencing (NGS), quantitative PCR (qPCR), and virus isolation methods from T. maculipennis (Tm)-related samples (Tm body-wash fluid and Tm body-ground samples) collected from habitats and sewage treatment facilities located at three research stations in Antarctica.ResultsVirome analysis detected the genomic fragments of human adenovirus (AdV) and human endogenous retrovirus (HERV) in Tm-related samples. These viruses are commonly found in human feces. In addition, plant viruses, such as pepper mild mottle virus (PMMoV) and cucumber green mottle mosaic virus (CGMMV), both known indicators of enteric viruses, were identified in all Tm-related samples, likely originating from wastewater. However, the low quantities of AdV and HERV genomes detected in Tm-related samples through qPCR, coupled with the non-viability of AdV in virus isolation tests, indicate that T. maculipennis has limited potential for mechanical transmission under the conditions in the studies.ConclusionsOur study represents the first evaluation of the potential risk of non-native species serving as vectors for viral pathogens in Antarctica. Although the viruses detected were in relatively low quantities and non-viable, this study highlights the importance of further evaluating the risks associated with non-native species, particularly as the likelihood of their introduction increases to Antarctica due to climate change and increased human activity
Binge-like Alcohol Administration Alters Decision Making in an Adolescent Rat Model: Role of N-Methyl-D-Aspartate Receptor Signaling
No full textAlcohol is one of the most used legal drugs abused worldwide, and its consumption is associated with high mortality and morbidity rates. There is an increasing concern about the starting age of consumption of this drug since it has become evident that it is at younger ages. The so-called "pattern of consumption by binge" corresponds to ingesting large amounts of alcohol in a short period and is the most popular among young people. Previous studies show that alcohol causes damage in different areas, such as the hippocampus, hypothalamus, and prefrontal cortex, and adolescents are more susceptible to alcohol toxicity. Alcohol inhibits the membrane glutamate receptor, NMDA-type glutamate receptors (NMDAR). Using a binge-like alcohol administration protocol in adolescent rats (PND25), we investigate decision making through the attentional set-shifting test (ASST) and alterations in the NMDAR signaling in related areas. We observe an impairment in executive function without alterations in NMDAR abundance. However, binge alcohol changes NMDAR signaling and decreases quantity in the synapse, mainly in the hippocampus and hypothalamus. We suggest that prefrontal cortex impairment could arise from damaged connections with the hippocampus and hypothalamus, affecting the survival pathway and memory and learning process
Villa El Golf (Punta Arenas – Chile): estrategias de implantación y morfología urbana de un patrimonio industrial
No full textLas 25 Jornadas de Patrimonio Industrial de INCUNA, celebradas en Gijón a finales de septiembre de 2023, han sido una cita de encuentro de investigadores y profesionales de diferentes disciplinas, asociaciones, técnicos de Instituciones y Administraciones Públicas, redes de Universidades, gestores culturales y turísticos, estudiantes o activistas patrimoniales, por la naturaleza de los temas abordados y sus positivas conclusiones constituyeron una gran oportunidad para la comunidad científica internacional.
Estas Jornadas las organiza INCUNA (Industria, Cultura, Naturaleza) ininterrumpidamente desde 1999. Esta entidad que surgió de la sociedad civil asturiana, tuvo desde el comienzo de los antedichos eventos una pretensión que concitaba intereses de distintos estratos ciudadanos, ya sean éstos del marco académico, con aquellos reclamos de trabajadores industriales, profesionales u asociaciones cívicas, preocupadas ante la lenta pérdida de la memoria del trabajo y del lugar en la sociedad civil, motivadas por la conservación del patrimonio de la industrialización, material e inmaterial