Universidad de Magallanes
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How Dangerous? Substance Use Risk Perceptions in Chilean Preadolescents
No full textEarly substance use initiation among children represents a significant risk to public health. Research suggests that early positive perceptions and cognitions of elementary students toward substance use may predict later use during adolescence. Studies among adolescent populations have shown an inverse relationship between substance use and risk perceptions. To gain insight into alcohol, tobacco, and marijuana risk perceptions prior to adolescence, we analyzed data from the Chilean Early Childhood Longitudinal Survey (ELPI). In a sample of 5,278 families (mean age of preadolescents 10.63 years, SD = .64; 50.5% males), our findings showed that an important proportion of Chilean 10 years old did not perceive occasional tobacco, alcohol, or marijuana use to be high-risk activities. However, the majority of respondents did consider daily substance use to be a high-risk activity, with some variation across substances. Overall, older preadolescents were more likely to consider substance use to be less risky compared to their slightly younger counterparts. Our analysis also demonstrated that past month substances use by caregivers were all found to be predictive of low-medium risk perceptions among preadolescents surveyed, while conversely, caregivers' negative reactions to finding out their child had used a substance decreased the likelihood of holding low-medium risk perceptions. Individuals from single-parent households were less likely to consider substance use as being high-risk compared to their peers. Preadolescents with caregivers reporting higher average incomes were also more likely to hold lower risk perceptions of occasional substance use. Implications for public policies to prevent substance use in the pre-adolescent population are discussed
EFFECTS OF COVID-19 CONFINEMENT ON THE HEALTH OF OLDER PEOPLE IN LATIN AMERICA: AN INTEGRATIVE REVIEW
No full textEl confinamiento, adoptado como medida preventiva frente al COVID-19, tuvo un impacto en la salud física, mental y cognitiva en las personas mayores. El aislamiento social y el confinamiento pro-longado originó una disminución de la actividad física y un incremento en los problemas de salud mental. Es esencial encontrar un equilibrio entre la protección de la salud pública y el mantenimiento del bienestar ge-neral de los individuos, especialmente aquellos en mayor riesgo. OBJETIVO. Identificar en la evidencia cien-tífica los efectos del confinamiento en la salud mental, física y psicosocial de las personas mayores como medida de prevención en la pandemia COVID-19 en Latinoamérica. METODOLOGÍA. Revisión integrativa de la literatura. Bases de datos electrónicas: WOS; BDENF; Scielo; PUBMED. Criterios de inclusión: artículos ori-ginales, en inglés, portugués y español; publicados desde el año 2020 y 2022. RESULTADOS. Del análisis de los 11 estudios incluidos en esta revisión resultaron 4 categorías relacionadas al efecto del confinamiento por pandemia por COVID-19: Bienestar psicoemocional, Bienestar y funcionalidad física, Capacidad cognitiva y mental y Vinculación social. CONCLUSIONES. Los hallazgos de esta revisión revelan un efecto sobre la salud física, mental y cognitiva de las personas mayores, derivado del confinamiento como medida sanitaria para mitigar la propagación del virus COVID-19. Se observa que la dimensión de salud mental es la más afectada. Finalmente, el aislamiento social implicó un cambio radical en el estilo y calidad de vida en este grupo etario
Análisis de las normas tributarias que regulan a los grupos empresariales en Chile
No full textLos grupos empresariales en Chile representan una base relevante para el desarrollo económico del país, estos conglomerados implican una articulación de carácter múltiple, a través de sus empresas relacionadas. En Chile no existe un sistema normativo codificado de los grupos empresariales, la legislación societaria, laboral y tributaria solo regula aspectos específicos de cada caso, por ello, es necesaria una mayor conjunción de la normativa para regular el funcionamiento tributario de los conglomerados empresariales. El objetivo de la investigación es analizar las normas tributarias que regulan a los grupos empresariales en Chile, respecto de su impacto en la organización de sus negocios, sin el riesgo que dicha organización sea calificada como una práctica elusiva tributaria. Este estudio se define como una investigación cualitativa, descriptiva y situacional. La metodología aplicada se estructura a través de un diseño no experimental, desde una perspectiva cualitativa y se aplican los modelos de análisis documental y de contenidos. Como resultado central del estudio, se puede concluir que las normas tributarias chilenas no imponen una única configuración tributaria, reconociendo el concepto de economía de opción, aceptando la “planificación fiscal”, cuando se aplica en el marco de las leyes y reglamentos vigentes. La conclusión indica que las empresas y grupos económicos tienen libertad para organizarse de la manera jurídica y tributaria que sea más idónea para el logro de los objetivos corporativos
A Long and Fruitful Cooperation in Atmospheric Aerosol Research between Cuba and Spain
No full textCuban and Spanish scientists have been studying the properties of atmospheric aerosols in Camagüey, Cuba, for more than 15 years, achieving notable scientific results at the local, regional, and global levels. Using instruments and expertise supplied by Spain, Cuban scientists have characterized local aerosol optical and microphysical properties and their chemical composition and optical absorbing properties. Aerosol optical depth (AOD) and Ångström exponent observations were used to validate MODIS satellite observations and broadband AOD from local pyrheliometers. Sun photometer cloud optical depth allowed us to characterize local cloudiness and its radiative forcing. Scientific work included climatologies of the solar radiation for the last four decades at Camagüey and of aerosols in the Caribbean basin in the last two decades. Another result was designing, building, and processing of a low-cost all-sky camera. Besides scientific results, the cooperation allowed the Cuban sun photometer observations to contribute to the Red Ibérica de Medida Fotométrica de Aerosoles and AERONET. A workshop celebrating 10 years of cooperation was held at Camagüey in 2016. The workshop participants evaluated the progress, difficulties, and challenges and inaugurated a Spanish angular calibration bench for solar radiation sensors at Camagüey. The workshop also included the first visit of a NASA scientist to Cuba, the only one visit. Cuban scientists became members of the International Science Team of the NASA Tropospheric Emissions: Monitoring of Pollution (TEMPO) satellite mission, just launched, participating in its prelaunch activities. Considering the joint capabilities we developed, Cuban-Spanish contribution is expected for the TEMPO postlaunch validation campaign
Environmental evolution of the Andes east of the North Patagonian Icefield since ∼19.3 ka
No full textWe examine the environmental evolution of the central Patagonian Andes from -19.3 ka to the present using lake sediment cores from Valle Chacabuco (-47 degrees S). Our results reveal the dominance of cold-tolerant herbs and shrubs between -19.3 and 11 ka, within which we observe a shift to Poaceae-dominated assemblages and a Pediastrum rise at-17.8 ka succeeded by a gradual arboreal rise that started at -14.5 ka and culminated with the establishment of Nothofagus-dominated woodlands between -9.8-8.8 ka. We interpret modest warming at -17.8 ka and -12.7 ka and increases in precipitation at -17.8 ka and -14.5 ka, followed by major warming and a precipitation decline at -11 ka that accentuated at -8.8 ka. Precipitation increased at -7.8 ka and led to the establishment of closed-canopy forests that have persisted with modest but significant fluctuations until recent. We detect abrupt vegetation changes at -17.7 ka, -12.7 ka, -11 ka, and -7.8 ka, driven primarily by changes in southern westerly wind (SWW) influence and, secondarily, by intense fire activity. Terrestrial and aquatic ecosystems show pervasive millennial and centennial-scale alternations between warm/dry and cold/wet states since similar to 11 ka contemporaneous with glacier fluctuations in nearby Monte San Lorenzo, suggesting recurrent oscillations in SWW influence. Deforestation and spread of non-native plants attest to disturbance by Chilean/European settlers since similar to 0.3 ka. Our results and conclusions reinforce the concept that variations in temperature and precipitation related to changes in the position/strength of the SWW underpin millennial/centennial timescales in the biosphere, hydrosphere, and cryosphere at Patagonian, zonal, and hemispheric scales
Effects of Concurrent Training on Biomarkers, Morphological Variables, and Physical Performance in People with Sarcopenic Obesity: A Meta-Analysis with Meta-Regression
No full textBackground and Objectives: This systematic review and meta-analysis aimed to analyze the available body of published peer-reviewed randomized controlled trials (RCTs) on the effects of concurrent training (CT) on biomarkers, morphological variables, and physical performance in people with sarcopenic obesity. Materials and Methods: Using six databases-PubMed, Medline, CINAHL Complete, Scopus, Cochrane Library, and Web of Science-a comprehensive literature search was conducted through July 2025. The GRADE, TESTEX, Rob 2, and PRISMA tools were used to assess the methodological quality and certainty. The protocol was registered in PROSPERO (CRD420251052935). Results: Out of 669 records, 8 RCTs with a total of 453 participants (68.9 +/- 11.1 years) were included. Fifteen overall and three subgroup meta-analyses revealed significant improvements (p 0.05) were observed in IL-6, CRP, total cholesterol, triglycerides, trunk fat, BF mass, and MIHS. On the other hand, an important result in the meta-regression revealed that weeks of training can predict decreases in BF (R-2 = 0.32; p = 0.02). Conclusions: CT has been associated with significant clinical improvements in biomarkers related to increased muscle mass and decreased BF percentage
Growth patterns and responses to climate variability of Subantarctic Pilgerodendron uviferum forests in the Aysen (∼47-48°S) and Magallanes (∼53°S) regions, southern Patagonia
No full textThe temperate forests of southern Chile are unique and complex ecosystems, threatened by climate change and anthropogenic activities. One of the long-lived and endemic species of these forests is the Guaitecas Cypress (Pilgerodendron uviferum), the southernmost conifer in the world, with a latitudinal distribution between 39 and 55 degrees S, from temperate rainy to Subantarctic climates, being an ideal model for studying the response of tree species to climate in high latitudes. The objective of this study is to determine the growth patterns of P. uviferum forests in Chilean regions of Aysen (similar to 47-48 degrees S) and Magallanes (similar to 53 degrees S) using ring-width chronologies of four and six forests in Aysen and Magallanes, respectively. A Principal Component Analysis identified two dominant patterns: PC1 associated with Magallanes chronologies, and PC2 with Aysen chronologies. Using ERA5-Land data (1979-2020), both components showed positive correlations with precipitation and negative correlations with temperature. PC1 was positively related to soil water content, while PC2 negatively. Contrasting responses were found with large-scale forcings, where PC1 was negatively correlated with AAO and PDO, and positively correlated with SOI, while PC2 showed the opposite pattern. Spectral analyses reinforce these results, showing regional differences in the growth patterns of P. uviferum. This opposite relationship suggests that regional growth patterns of P. uviferum are influenced by large-scale modes of climate variability affecting southern South American climates. These results highlight the potential of P. uviferum chronologies to represent the large-scale climate variability of southern South America and to recover the low-frequency signal in climate reconstructions from this species
Polyplacophoran Assemblages in Shallow Waters of the West Antarctic Peninsula: Patterns of Diversity, Composition and Abundance
No full textFor the first time, field surveys for exploring the diversity and composition of shallow-water polyplacophorans in West Antarctica have been conducted. During the austral summer sampling campaigns of 2022, 2023 and 2024, a total of 1717 specimens of four species were collected from 21 localities. The composition, abundance, and diversity estimate of the assemblages showed that richness decreased southward due to changes in species composition. The ordination analysis showed a high similarity among localities. Thus, of the seven shallow-water chiton species previously recorded in Antarctica, only four were recorded here. Of them, Tonicina zschaui, Leptochiton kerguelensis, and Hemiarthrum setulosum were the most common and abundant, while Callochiton bouveti was the rarest and least abundant species. The diversity of shallow-water polyplacophorans in this area of Antarctica is low compared to the higher number of species reported in other sub-Antarctic regions. It is suggested that the effect of ice cover on shallow-water habitats could affect the abundance and diversity of chitons. In turn, the high similarity of assemblages may be due to the transport of larvae and juveniles by ocean currents and rafting between the studied sites
An analysis of renewable energy resources and options for the energy transition in Chile
No full textThis study analyses renewable energy resources, infrastructure, and practical options to accelerate the energy transition and unlock Chile's potential as an exporter of renewable energy and products. We analyse data on the potential of wind and solar energy to determine the best areas for renewable projects. The progress of the energy transition occurring in Chile is reviewed in the context of historical events. The abundant renewable energy resources far exceed current demand and offer exceptional harvesting conditions. However, geographical limitations and a lack of enabling infrastructure may limit the participation of Chile in the world net-zero economy. A comparison is made with the UK to provide a broader perspective. This identifies order-of- magnitude differences in the power available in different locations, highlighting the importance of considering where best to deploy limited resources. International cooperation is required to make the best use of the available renewable energy. Three practical international options to unlock Chile's potential are discussed. Further technical-economic assessment of these energy-transition acceleration paths is recommended. The data and results are integrated into a set of 2D/3D visualisations, facilitating visual insights and enabling a comprehensive understanding of the challenges and opportunities facing Chile
Lake sedimentation and landscape evolution since ∼31 ka in Isla Grande de Chiloe, northwestern Patagonia (42°S)
No full textWe combine sedimentological analysis, high-resolution imaging, and X-ray fluorescence data to investigate sedimentary processes and landscape evolution from lake records in central Isla Grande de Chiloé (42 degrees 23 ' S, 72 degrees 49 ' W), northwestern Patagonia between similar to 31-1.6 ka. The oldest section consists of laminated inorganic silts with a local geochemical signature deposited in a low-energy environment (Stage 1: similar to 31-26 ka), interrupted by hiatuses and coarse-grained allochthonous deposits associated with high-energy events (Stage 2: similar to 26-18 ka). The end of laminated facies and increasing organic matter led to a rising productivity trend and slope stability (Stages 3 and 4: similar to 18-14.1 ka, similar to 14.1-10.8 ka), along with volcaniclastic influx advected from the Andean Southern Volcanic Zone (Stage 5: similar to 10.8 -1.6 ka). We interpret sedimentation in proglacial lakes fed by varying intensities of glacier meltwater from the western margin of the Golfo Corcovado piedmont lobe during the LGM in Patagonia, followed by a sudden change to closed-basin lakes driven by glacier withdrawal at the onset of the Last Glacial Termination (similar to 18 ka). This detachment shifted the facies composition and arrangements toward predominance of climate and distal volcanic processes until similar to 1.6 ka. Our records capture salient millennial-scale features of the environmental evolution from western Patagonia since similar to 31 ka, and match paleoclimate records at zonal and hemispheric scales. Our facies analysis underscores the presence of centennial fluctuations and instantaneous processes through glacial and non-glacial lake regimes