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Generalizability of the value of methods based on learning analytics remains one of the big challenges in the field of learning analytics. One approach to testing generalizability of a method is to apply it consistently in different learning contexts. This study extends a previously published work by examining the generalizability of a learning analytics method proposed for detecting learning tactics and strategies from trace data. The method was applied to the datasets collected in three different course designs and delivery modalities, including flipped classroom, blended learning, and massive open online course. The proposed method combines process mining and sequence analysis. The detected learning strategies are explored in terms of their association with academic performance. The results indicate the applicability of the proposed method across different learning contexts. Moreover, the findings contribute to the understanding of the learning tactics and strategies identified in the trace data: learning tactics proved to be responsive to the course design, whereas learning strategies were found to be more sensitive to the delivery modalities than to the course design. These findings, well aligned with self-regulated learning theory, highlight the association of learning contexts with the choice of learning tactics and strategies.

This research examines the factors that influence the intention to use information technology in the classroom by primary school teachers based on the Unified Theory of Acceptance and Use of Technology and their technological predisposition. In particular, the relationship between teachers' innovativeness and their beliefs associated with the use of technology in the classroom was analyzed. To this end, 212 teachers from three provinces of Chile were surveyed. Data were analyzed using partial least squares statistical technique. Results indicate that performance expectancy, social influence, and facilitating conditions influence the intention to use information technology in the classroom. It was found that the intention to use construct is a determinant of the use of technology, which validates the robustness of the model in a context of primary education. In addition, it was validated that teachers' innovativeness determines their beliefs about the use of information technology in the classroom.

The global pandemic caused by coronavirus disease-2019 (COVID-19) disrupted both public and private life for many. Concerning medical students, practical teaching and classrooms were substituted with a virtual curriculum. However, how this new academic environment has affected students' health and lifestyles has yet to be studied. In this study, we surveyed 2,776 students from nine different countries about changes in their university curricula and potential alterations in their daily habits, physical health, and psychological status. We found negative changes across all countries studied, in multiple categories. We found that 99% of respondents indicated changes in their instruction delivery system, with 90% stating a transition to online education, and 93% stating a reduction or suspension of their practical activities. On average, students spent 8.7 hours a day in front of a screen, with significant differences among countries. Students reported worsened studying, sleeping, and eating habits with substantial differences in Latin American countries. Finally, the participants frequently expressed onset and increase in both mental and physical health symptoms: backache, asthenopia, irritability, and emotional instability. Altogether, these results suggest a potential risk in the health and academic performance of future doctors if these new academic modalities are maintained.

Historic achievement gaps in mathematics favoring male students have recently started to narrow, close, or even shift in favor of female students. Still, in many countries, male students continue to outperform their female counterparts in international mathematics assessments. Chile has one of the highest mathematics achievement gaps in the world, as shown by international assessment tests, with males outperforming females. Using nationally representative longitudinal data and multigroup latent growth modeling (LGM), the purpose of this study was to track the gender scoring gap in mathematics from kindergarten to grade 12. Findings showed gender differences emerged during preschool and increasingly widened as students progressed through school. Although the gap subsided slightly between grades 10 and 12, the initial gap almost doubled by the end of high school, with important implications for access to higher education and choice of major.

This article examines teachers' subject expertise in a context where geography could be considered a neglected school subject. Using an empirical approach to the problem, the article aims to provide a view on the dynamics of teaching primary geography in Chile, through considering teachers' narratives on curriculum making and their associated conceptualisations of the discipline. 21 rural educators were interviewed about geography education to gain a general view of primary geography in the country. Findings reveal the need to understand how teachers conceive of and accommodate geographical knowledge. Even though there is a recognised chain of pressures regarding curriculum changes and deficient initial teacher training, geography as a school subject is still in place because of teachers' practices. Recognising their dynamics will shed light on how to make geography sustainable as a school subject in the future.

Studies on faculty income have typically focused on disparities associated with gender and race. Surprisingly, much less attention has been paid to the social class background of university faculty and how it might affect their pathways to the professoriate and their opportunities to access high-paying positions. We attempted to address this gap in the literature by looking at a sample of faculty working at Chilean universities. We used a path analysis approach to estimate not only the direct effects of social class of origin on income but also the indirect mechanisms through which social class of origin influences faculty income. We posed two alternative conceptual perspectives with regard to the effects of social class on income--social reproduction and human capital. We found that faculty who come from the upper social class have access to higher-quality undergraduate education and to more prestigious PhD-granting universities and they report higher earnings as compared with those who come from a low social class. These findings resemble a dynamic of cumulative educational advantages that provides grounds to the theory of social reproduction. Although it could be argued that the positive effect of prestige of the PhD-granting university on income is in line with the human capital theory, we claim that such effect cannot be analyzed independently from the direct and indirect relationships that exist between social class of origin and the prestige of the university from which faculty obtained their doctorate degrees.

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effectiveness of remedial mathematics courses in post-secondary education has been a controversial topic for years. Higher Education institutions need their students to have basic understandings of the subjects to be imparted in the first semesters, but since they come with different backgrounds and prior knowledge, this is not always possible and many students struggle in their first courses. This paper presents the results of students' adoption and learning outcomes of using four MOOCs as a complementary study resource for an on-campus calculus diagnostic exam. Over 700 newly admitted university students had to take a mandatory diagnostic exam on four calculus topics before classes started. MOOCs were proposed as a voluntary support for studying these subjects. Following a mixed method analysis, we studied why and when the students used the online courses and we also measured the effects of its use in terms of the students' diagnostic exam grades and learning outcomes. The results show that students mostly used the MOOCs to study the subjects that were not covered in their secondary studies. Students who were active in these course topics obtained better scores, having more chances of passing the diagnostic exam than students who did not study with the MOOCs. Furthermore, students not only used the MOOCs for studying for the exam, but also for refreshing concepts for future courses.

The variability and drivers of carbon and water fluxes and their relationship to ecosystem water use efficiency (WUE) in natural ecosystems of southern South America are still poorly understood. For 8 years (2015–2022), we measured carbon dioxide net ecosystem exchange (NEE) and evapotranspiration (ET) using eddy covariance towers in a temperate rainforest and a peatland in southern Chile. NEE was partitioned into gross primary productivity (GPP) and ecosystem respiration (Reco), while ET was partitioned into evaporation (E) and transpiration (T) and used to estimate different expressions of ecosystem WUE. We then used the correlation between detrended time series and structural equation modelling to identify the main environmental drivers of WUE, GPP, ET, E and T. The results showed that the forest was a consistent carbon sink (- 486 ± 23 g C m -2 yr -1), while the peatland was, on average, a small source (33 ± 21 g C m -2 yr -1). WUE is low in both ecosystems and likely explained by the high annual precipitation in this region (∼ 2100 mm). Only expressions of WUE that included atmospheric water demand showed seasonal variation. Variations in WUE were related more to changes in ET than to changes in GPP, while T remained relatively stable, accounting for around 47 % of ET for most of the study period. For both ecosystems, E increased with higher global radiation and higher surface conductance and when the water table was closer to the surface. Higher values for E were also found with increased wind speeds in the forest and higher air temperatures in the peatland. The absence of a close relationship between ET and GPP is likely related to the dominance of plant species that either do not have stomata (i.e. mosses in the peatland or epiphytes in the forest) or have poor stomatal control (i.e. anisohydric tree species in the forest). The observed increase in potential ET in the last 2 decades and the projected drought in this region suggests that WUE could increase in these ecosystems, particularly in the forest, where stomatal control may be more significant. [ABSTRACT FROM AUTHOR]

This study aims to identify motivational and attitude variables among Chilean young English learners from Concepción. A child-appropriate Likert scale questionnaire was distributed to 137 students from the 3rd, 4th, and 5th grade of two state-run primary schools. The instrument considered five variables: attitude towards English, intrinsic motivation, extrinsic motivation, Ideal L2 Self, and parent-oriented motivation, because the eclectic nature of early language learning has been shown to be influenced by these factors. The variables for teacher profile considered years of teaching experience, training in primary English language teaching, and access to multisensory and audio-visual materials. A confirmatory factor analysis was conducted to determine the internal consistency of the instrument. The Mann–Whitney U test and the Kruskal–Wallis H-test using Dunn's post hoc contrast were used to compare the motivations and attitudes by gender, teacher profile, and grade. Spearman's rho correlation coefficient was then used to identify the relationship between the target variables and the teacher profile. Results show that teacher profile is a key factor in motivation and attitude to learning English, particularly their access to multisensory and audio-visual materials. This study's main novelty is that it is the first time a questionnaire focused on children's attitudes and motivations has been applied in Chile, with clear implications for teacher education and policy implementation assessment. [ABSTRACT FROM AUTHOR]

Obtaining viable Argopecten purpuratus seeds faces challenges, especiallyci the unpredictability of the marine environment and high production costs in hatcheries. However, improving the method of "Broodstock Conditioning In Hatcheries" is key to ensure permanent seed supplies by minimizing the dependence on marine conditions and by maximizing economic viability in hatcheries. In an effort to overcome these barriers, broodstock were conditioned into two different environments: (a) Natural Environment: Natural marine conditions located in Bahía Inglesa, Atacama Region, Chile. (b) Hatchery: Laboratory conditions to achieve gonadal maturation, spawning induction, fertilization and larval development. The purpose of this research was to evaluate how the type of reproductive conditioning affects the reproductive potential and nutritional quality of the progeny. Both methods were successful at inducing the necessary maturity for reproduction, obtaining viable gametes and larvae. On the other hand, it was observed that in the natural environment, the oocytes and D larvae reached a greater size and nutritional value, being the most significant differences with (p < 0.05): the size of the D larvae reached figures of 95.8 ± 3.1 μ m and 91.2 ± 2.7 μ m in the environment and hatchery, respectively; the lipid content in dry mass was 25.2 ± 3.1 mg g − 1 and 13.5 ± 1.9 mg g − 1 for the natural environment and hatchery, respectively. Although quality indicators in hatcheries were slightly lower compared to the natural environment, the possibility of conditioning A. purpuratus broodstock independently of environmental variability highlights the importance of further optimizing broodstock conditioning aspects in hatcheries that would allow more predictable and sustainable production. [ABSTRACT FROM AUTHOR]

The variability and drivers of carbon and water fluxes and their relationship to ecosystem water use efficiency (WUE) in natural ecosystems of southern South America are still poorly understood. For eight years (2015–2022), we measured water and carbon fluxes using eddy covariance towers in a temperate rainforest and a peatland in southern Chile. Different expressions for ecosystem WUE were derived from estimates of gross primary productivity (GPP) and evapotranspiration (ET), which was further partitioned into evaporation (E) and transpiration (T). We then used the correlation between detrended time series and structural equation modeling to identify the main environmental drivers of WUE, GPP, ET, E and T. The results showed that WUE is low in both ecosystems, and likely explained by the high annual precipitation in this region (∼2100 mm). Only expressions of WUE that included atmospheric water demand showed seasonal variation. Variations in WUE were related more to changes in ET than to changes in GPP, while T remained relatively stable accounting for around 47 % of ET for most of the study period. For both ecosystems, E increased with higher global radiation, higher surface conductance and when the water table was closer to the surface. Higher values for E were also found with increased wind speeds in the forest and higher air temperatures in the peatland. The absence of a close relationship between ET and GPP is likely related to the dominance of plant species that either do not have stomata (i.e., mosses in the peatland or epiphytes in the forest) or have poor stomatal control (i.e., anisohydric tree species in the forest). The observed increase in potential ET in the last two decades and the projected drought in this region suggests that WUE could increase in these ecosystems, particularly in the forest, where stomatal control may be more significant. [ABSTRACT FROM AUTHOR]

The study analyzes the way in which adolescents' temperamental characteristics interact with parental control to shape adolescent decision making development. A sample of high-school Chilean adolescents (N = 391) answered a self-report questionnaire that included measures of behavioral autonomy (the extent to which adolescents make decisions in personal and prudential domains), parental behavioral and psychological control, and temperamental characteristics. A path analysis model indicated that adolescents' anger-frustration had a direct association with decision-making in the personal and prudential domains; fearfulness had an inverse association with adolescent decision-making, but only in the prudential domain. Perceived psychological control was associated with adolescents' reduced decision-making autonomy in the personal domain, while perceived behavioral control was associated with less adolescent autonomy in both personal and prudential domains. Additionally, a moderation effect was found such that the association of parental behavioral control on decision-making in the prudential domain was dependent on the adolescent fearfulness level. (Contains 3 tables and 2 figures.)

The hypothesis that independently of sex, brain volume (BV) and head circumference (HC) are positively and significantly associated with intellectual quotient (IQ) was examined in a sample of 96 high school graduates of high [Wechsler Intelligence Scale for Adults--Revised (WAIS-R) is greater than 120] and low IQ (WAIS-R is less than 100) (1:1), from high and low socioeconomic stratum (SES), and of both sexes (1:1) from the Chile's metropolitan region. Brain development was assessed by magnetic resonance imaging (MRI) and anthropometric measurements were made applying standardized procedures. Results showed that, in general, no significant differences were observed between absolute and adjusted brain parameters by body size. Differences in BV and HC can be more properly attributed to differences in IQ and not to SES both in males and females. Independently of sex, BV was the only brain parameter that contributed to explain IQ variance. These findings confirm the hypothesis that independently of sex, BV and HC are positively and significantly associated with IQ.

Copyright of Polis (07176554) is the property of Polis - Revista Academica Universidad Bolivariana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Measurements of ecosystem carbon (C) fluxes in temperate forests are concentrated in the Northern Hemisphere, leaving the functionally diverse temperate forests in the Southern Hemisphere underrepresented. Here, we report 3 years (February 2018 to January 2021) of C fluxes, studied with eddy‐covariance and closed chamber techniques, in an endangered temperate evergreen rainforest of the long‐lived paleoendemic South American conifer Fitzroya cupressoides. Using classification and regression trees, we analyzed the most relevant drivers and thresholds of daily net ecosystem exchange (NEE) and soil respiration. The annual NEE showed that the forest was a moderate C sink during the period analyzed (−287 ± 38 g C m−2 year −1). We found that the capacity to capture C of the Fitzroya rainforests in the Coastal Range of southern Chile is optimal under cool and rainy conditions in the early austral spring (October–November) and decreases rapidly toward the summer dry season (January–February) and autumn. Although the studied forest type has a narrow geographical coverage, the gross primary productivity measured at the tower was highly representative of Fitzroya and other rainforests in the region. Our results suggest that C fluxes in paleoendemic cool F. cupressoides forests may be negatively affected by the warming and drying predicted by climate change models, reinforcing the importance of maintaining this and other long‐term ecological research sites in the Southern Hemisphere. Plain Language Summary: Forest ecosystems play a central role in climate policy because their growth removes nearly a third of the anthropogenic carbon emissions to the atmosphere. Yet, warming and drying with climate change threaten the capacity of forests to absorb carbon in some regions. Measuring the carbon sink of forests and its climatic control is thus essential for ecosystem management and climate policy, but current measurements are overwhelmingly concentrated on the Northern Hemisphere leaving a gap in the Southern Hemisphere. Here, we present the first measurements of carbon fluxes of an adult 300‐year‐old temperate rainforest of the ultra‐long‐lived conifer Fitzroya cupressoides in southern Chile. This conifer is a paleoendemic tree confined to a few cool and very wet climate refugia. Our results show that the forest can photosynthesize year‐round because it is particularly adapted to cold and rainy conditions. Photosynthesis consistently exceeds ecosystem carbon losses by respiration between July and January, resulting in a moderate carbon sink compared with temperate forests in the Northern Hemisphere. Summer drying and warming enhance carbon losses by respiration and thus weaken the carbon sink capacity, implying that the ongoing and future climate drying and warming in the region threaten the carbon sink of this unique rainforest. Key Points: We present the first analysis of carbon fluxes of a paleoendemic temperate rainforest in a global drying hotspotThe paleoendemic ecosystem thrives under cool and wet conditions during the austral springProjected warming and drying in the region threaten the carbon sink capacity of this globally unique, ultra‐long‐lived rainforest [ABSTRACT FROM AUTHOR]

A large (M w 7.6) megathrust earthquake occurred on 2016 December 25 in Southern Chile, south of the Chiloé Island (74.2°W, 43.3°S) in the South America–Nazca subduction zone. This earthquake was the first large event in this seismotectonic segment since the M w 9.5 1960 Valdivia megathrust earthquake and broke a ~50-km-long segment of the southern part of its rupture zone. Source parameters are inferred from teleseismic broad-bands, strong motions, GPS, cGPS, InSAR and tide gauge data. We show that the joint inversion significantly improves the resolution of the slip distribution, taking advantage of each data set. Our slip models predict a single slip patch of 70 km × 60 km with a maximum slip of 3.2 ± 0.8 m and a moment magnitude of 7.64. The hypothesis from previous studies that the Chiloé earthquake released energy accumulated before the Valdivia earthquake is not supported by the ensemble of geodetic, seismological and tsunami data. Hence, the Chiloé earthquake most likely released all the strain accumulated in the rupture area since the 1960 earthquake. [ABSTRACT FROM AUTHOR]

Siliceous spicules are micro‐laminated geyserite deposits, or micro‐stromatolites, found around high temperature hot‐springs and geysers, associated with intermittent splashes of water. Understanding conditions of formation of these structures will give insights of critical parameters involved in prebiotic environments and early life. We provide a new data set around two geysers from the El Tatio hydrothermal field, Atacama Desert, Chile, a modern analogue for habitable environments on early Earth and Mars. Small spicules (<5 mm diameter) dominate in the near vent areas, whereas larger spicules (>5 mm diameter) form complex columnar structures in the distal vent (>0.3 m distance from the vent). Hydrodynamics, eruption periodicity, and environmental conditions modulate the temperature and cooling patterns around vents. During geyser eruptions, the temperature of water reaching the ground decreases with the distance from the vent. Cooling is stronger during the evenings, due to strong winds and cold air temperature. Rapid water cooling drives supersaturation of amorphous silica, and therefore precipitation rates increase significantly with distance from the vent. Cooling also controls changes in the bacterial communities, from thin filaments <1 μm diameter predominating closer to the vent, to 1–2 μm diameter filaments in the distal vent. Changes in the silica precipitation rate and biota may control the growth of spicules and the transition to columns. Estimated precipitation rates of silica provide a first approximation of the longevity of these structures and the timing for the formation of internal laminations. Microlamination will form in year time‐scales closer to the vent, and weeks farther from the vent. Key Points: Precipitation rates of silica around the geyser increase with the distance from the ventStrong daily changes in air temperature and wind speed modulate the precipitation rates of silica at El TatioSpicule size and internal lamination increase farther away from the vent due to change in cooling and precipitation rates [ABSTRACT FROM AUTHOR]

Copyright of Limite is the property of Universidad de Tarapaca, Departamento de Filosofia y Psicologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agricultural activities are important contributors to greenhouse gas (GHG) emissions in southern Chile. Three types of agricultural systems coexist within this region: traditional, conventional and agroecological. Historical changes in agricultural practices were identified from bibliographic sources and field surveys of 10 farms of each system type. A similarity analysis between systems was carried out using the survey data, which were also input to the Cool Farm Tool software to estimate GHG emissions of carbon dioxide, methane and nitrous oxide. The main historical changes identified were: (i) replacement of organic inputs by chemical products, (ii) replacement of workforce by agricultural machinery, (iii) decrease in crop diversity and (iv) decrease in total agricultural area. A multivariate analysis showed that agroecological systems are different from the traditional and conventional systems mainly because of the land use and the amount of organic fertiliser applied. However, no significant differences were found in the GHG emissions, which on average were 2999 ± 1521, 3443 ± 2376 and 3746 ± 1837 kg CO2-eq ha−1 year−1 (traditional, conventional and agroecological, respectively). Enteric fermentation was the main source of emissions in all agricultural systems, therefore methane was the most important GHG. Identifying the sources and practices that produce more emissions should help to improve management to reduce GHG emissions. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the current study was to cross-culturally adapt and validate an online questionnaire to assess eating habits and physical activity of university students under confinement due to coronavirus disease (COVID-19). Design: Generation of a cross-sectional online survey to university students conducted during confinement due to COVID-19. The study was divided into two phases. Settings: Students, Chile. Participants: Phase 1 considered the process of translation and back translation, expert panel, cultural adaptation and the generation of a pilot to validate a preliminary format of the questionnaire. In Phase 2, information from the instrument was collected from two hundred and sixty-eight university students, ages 16 to 30 years old, with a mean age of 21·6 (3·3) The major proportion of participants were female (82 %). Results: The adapted questionnaire was statistically validated in three dimensions: (A) eating habits and behaviours during quarantine, (B) perception of risk and (C) physical activity changes during the quarantine. The reliability of Cronbach's α for dimensions A, B and C was 0·59, 0·85 and 0·97, respectively. The complete questionnaire obtained 0·61 in internal consistency and 0·61 (0·58–0·67) ICC reliability. A statistically significant positive correlation matrix was observed. Conclusions: This questionnaire is a practical tool to obtain accurate information about the relation of COVID-19 confinement on people's eating habits and physical activity. Therefore, it could contribute to establishing appropriate strategies to prevent negative effects on people's health. [ABSTRACT FROM AUTHOR]

The central area of Chile's Valparaiso Region has been classified as a seismic gap for a major earthquake, which makes it very important to understand the seismic hazard of the zone. Generally, seismic codes consider a qualitative classification of sites to estimate the possible damage in the case of an earthquake scenario. Estimating the values of acceleration could be very important to prevent damages and increase preparedness for these rare events. In this research, a qualitative and quantitative estimation of seismic hazard is performed in the study area (Valparaiso region between Papudo and San Antonio 32°–34° S). This is achieved through an integrated and relatively economical approach which considers the information from Geology, Geophysical experiments (Gravity and seismic methods), and Geotechnical analyses. The results of the geophysical survey and geology information allow dividing the zone into five site types through a new proposal of site classification that depends not only on the Vs30, but also on the sites predominant period (T0), which is an innovation of this work for the Chilean code. The Peak Ground Acceleration (PGA) values in the study zone were estimated using a Ground Motion Predictive Equation developed for the Chilean subduction zone. Additionally, we consider three different seismic scenarios according to the history of events in Central Chile. The results of this quantitative analysis show PGA values up to 0.52 g for the median and 1.2 g for the 84th percentile of the scenarios. Overall, the highest accelerations (PGA) are in zones with low shear wave velocities (< 500 m/s), a long predominant period (> 0.4 s) and where geology establishes the presence of low stiffness soils. The comparison of response spectra from the model against records from 2010 Maule and 1985 Valparaiso earthquakes shows available models tend to overpredict the intensities. [ABSTRACT FROM AUTHOR]

Due to this worldwide COVID-19 pandemic, Chilean universities were forced to quickly change their face-to-face classes to online. In this context, the Department of Chemical Engineering (DIQ) of the University of Magallanes, Chile, seeks different Emergency Remote Teaching strategies for its students. This article reports they experience delivering technical process simulation skills to their final year undergraduate civil engineering chemical engineering students. Due to problems connecting externally with the commercial software Aspen HYSYS, housed at the university, the open source software DWSIM is taught as an alternative. The material content was adapted, and video tutorials were created to meet learning objectives. This software was taught in a new module inside the Project Engineering course to train the skills required for the students to design and simulate a chemical plant. We received positive feedback and constructive critics from the students through an anonymous survey and discussion forum. Subsequently, DIQ launched its YouTube channel named DIQ_DWSIM with the videos made to the online community, positively impacting Spanish-speaking people who wish to learn to use DWSIM. As an indirect impact, two universities have used this channel as support material in their process simulation courses. A second survey was conducted on our YouTube audience resulting in the consolidation this open online educational resource for higher education learning. [ABSTRACT FROM AUTHOR]

Bovine tuberculosis (TB) is a chronic disease caused mainly by Mycobacterium bovis, a zoonotic pathogen that has a worldwide distribution causing serious economic losses for milk and meat producers. In Chile, the disease in dairy cattle has a heterogeneous distribution, where the Metropolitan Region concentrates the highest animal prevalence and the main challenge for the national control and eradication programme. In this epidemiological context, vaccination with the M. bovis Bacillus Calmette-Guerin (BCG) vaccine might be a useful strategy for disease prevention and control. The objective of this study was to assess the efficacy and impacts on productivity and fertility of vaccination with the BCG Russia strain in 11 month-old heifers from a dairy farm, under a natural transmission condition. Sixty-two animals were vaccinated via the subcutaneous route with the equivalent of one human dose of BCG, and 60 control animals received saline. Subsequently, blood sampling was performed at 3, 6, 9, 12, 15 and 18 months post-inoculation, and infection status was determined using the IFN? release assay (IGRA) with the DIVA (differentiate infected from vaccinated animals) antigens ESAT-6, CFP-10 and Rv3615c. Efficacy was calculated as the percentage of reduction in the incidence of infection attributable to vaccination, which showed a statistically significant level of overall protection of 66.5%. No adverse effects on fertility and production were recorded. In contrast, we observed beneficial effects of vaccination on several milk production parameters, with the milk yield in the first 100 days after calving in the BCG group significantly higher compared to unvaccinated heifers (p < .05). These results suggest that BCG vaccination of heifers in a natural transmission setting might result in both sanitary and productive benefits, supporting its implementation as a new strategy for TB prevention in a high prevalence area of Chile. [ABSTRACT FROM AUTHOR]

Snow cover area is dramatically decreasing across the Los Andes Mountains and the most relevant water reservoir under drought conditions. In this sense, monitoring of snow cover is key to analyzing the hydrologic balance in snowmelt-driven basins. MODIS Snow Cover daily products (MOD10A1 and MYD10A1) allow snow cover to be monitored at regular time intervals and in large areas, although the images often are affected by cloud cover. The main objective of this technical note is to evaluate the application of an algorithm to remove cloud cover in MODIS snow cover imagery in the Chilean Andes mountains. To this end, the northern region of Chile (Pulido river basin) during the period between December 2015 and December 2016 was selected. Results were validated against meteorological data from a ground station. The cloud removal algorithm allowed the overall cloud cover to be reduced from 26.56% to 7.69% in the study area and a snow cover mapping overall accuracy of 86.66% to be obtained. Finally, this work allows new cloud-free snow cover imagery to be produced for long term analysis and hydrologic models, reducing the lack of data and improving the daily regional snow mapping. [ABSTRACT FROM AUTHOR]

Background: Healthcare workers (HCWs) are at high risk of exposure to SARS-CoV-2. Cross-sectional studies have provided variable rates of seroprevalence in HCWs. Longitudinal assessments of the serological response to Covid-19 among HCWs are crucial to understanding the risk of infection and changes in antibody titers over time. We aimed to investigate seroprevalence and risk factors associated with seroconversion in a prospective cohort of HCWs during the peak of the first wave of the Covid-19 pandemic.Methods: We conducted a longitudinal study among 446 front-line HCWsin a tertiary-care hospital in Chile from April to July 2020. IgG was determined monthly using two different ELISAs in serum samples of HCWs, during the three-month period. In each visit, demographic data, symptoms, risk factors, and exposure risks were also assessed.Results: The overall seroprevalence at the end of the study period was 24% (95% CI20.2-28.3), with 43% of seropositive HCWs reporting no prior symptoms. Seroconversion rates significantly differed over the study period, from 2.1% to as high as 8.8% at the peak of the epidemic. There were no statistically significant differences observed between HCWs in direct clinical care of patients with Covid-19 and those working in low risk areas. Antibody titers appeared to wane over time.Conclusions: HCWs were severely affected with a high rate of seroconversion that appeared to mirror the local epidemiological situation. A significant amount of participants underwent an asymptomatic infection, highlighting the need for improved surveillance policies. Antibody titers appear to wane over time; further studies to understand this finding's impact on the risk of reinfection are warranted. [ABSTRACT FROM AUTHOR]

The terrestrial isopods of Chile make a group on which until now only a few studies have been done, most of which based mainly on species records in isolated zones. The aim of the present study was to make an attempt at characterization of the isopods present in three coastal protected areas in the Atacama Desert and northern-central Chile, and compare the results with literature records for northern and central Chile. The collected specimens belong to the genus Benthanoides (Oniscoidea, Philosciidae), probably to the species Benthanoides pauper that was originally described for central Chile. The obtained results would not agree with literature records that described the presence of two species of the genus Tylos (Oniscoidea, Tylidae) between 26-29°S, and it would be the first isopod genus recorded north of 26°S (Paposo priority site, Antofagasta Region). More systematic and ecological studies would be necessary for understanding the geographical distribution of Chilean terrestrial isopods. Resumen: Los isópodos terrestres de Chile conforman un grupo sobre el que hasta ahora se han realizado pocos estudios, la mayoría de los cuales se basan principalmente en registros de especies en zonas aisladas. El objetivo del presente estudio fue intentar caracterizar los isópodos presentes en tres áreas costeras protegidas del desierto de Atacama y centro-norte de Chile, y comparar los resultados con registros de la literatura para el norte y centro de Chile. Los especímenes recolectados pertenecen al género Benthanoides (Oniscoidea, Philosciidae), probablemente a la especie Benthanoides pauper que fue descrita originalmente para el centro de Chile. Los resultados obtenidos no concordarían con los registros de la literatura que describían la presencia de dos especies del género Tylos (Oniscoidea, Tylidae) entre 26-29°S, y sería el primer género isópodo registrado al norte de 26°S (sitio prioritario Paposo, Región de Antofagasta). Serían necesarios estudios más sistemáticos y ecológicos para comprender la distribución geográfica de los isópodos terrestres chilenos. [ABSTRACT FROM AUTHOR]

Vibrio parahaemolyticus is the leading cause of seafood-associated bacterial gastroenteritis worldwide. Although different studies have focused on its pattern of variation over time, knowledge about the environmental factors driving the dynamics of this pathogen, within the Chilean territory, is still lacking. This study determined the prevalence of total and pathogenic V. parahaemolyticus strains (tdh and/or trh genes) in mussels (Mytilus chilensis) collected from two natural growing areas between 2017 and 2018, using selective agar and PCR analysis. V. parahaemolyticus was detected in 45.6% (93/204) of pooled samples from the Valdivia River Estuary. The pathogenic strains carrying the tdh and/or trh gene were detected in 11.8% (24/204): tdh in 9.8% (20/204), trh in 0.5% (1/204), and 1.5% (3/204) presented both genes. In Reloncaví Fjord, V. parahaemolyticus was detected in 14.4% (30/209) of the samples, pathogenic V. parahaemolyticus carrying the trh gene was detected in 0.5% (1/209) of the samples, while the tdh gene was not detected in the samples from this area. The total count of mauve-purple colonies typical of V. parahaemolyticus on CHROMagar was positively associated by multivariate analysis with area, water temperature, and salinity. Similarly, V. parahaemolyticus detection rates by PCR had a positive correlation with the area and water temperature. The chances of detecting total V. parahaemolyticus in the Valdivia River Estuary are significantly higher than in the Reloncaví Fjord, but inversely, during spring-summer months, the interaction factor between the area and temperature indicated that the chances of detecting V. parahaemolyticus are higher in the Reloncaví Fjord. Interestingly, this period coincides with the season when commercial and natural-growing shellfish are harvested. On the other hand, pathogenic V. parahaemolyticus tdh + was significantly correlated with an increase of water temperature. These environmental parameters could be used to trigger a warning on potential hazard, which would influence human health and economic losses in aquaculture systems. [ABSTRACT FROM AUTHOR]

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Copyright of Formación Universitaria is the property of Centro de Informacion Tecnologica (CIT) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Growing evidence shows that atopic dermatitis (AD), food allergy (FA), allergic rhinitis, and asthma are largely determined during the first 1000 days (time elapsed from conception to the 2nd birthday). The ARIES birth cohort aims to determine prenatal and perinatal conditions, as well as genetic and epigenetic factors, that participate in the early setting of immune responses, and the role of these in the later determination of the risk of allergic diseases and asthma in the offspring.Methods: We have designed a birth cohort of 250 families with prenatal recruitment (~ 14 weeks). We will genotype relevant allergy/asthma-associated variants in trios and will perform immunophenotyping and evaluation of allergy biomarkers in cord blood. At 1 and 2 years of age we will assess if infants have developed allergic sensitization, AD, FA, as well as biomarkers of asthma including the asthma predictive index. We will also evaluate how maternal conditions modify immune programming through epigenetic modifications and will then depict newborn epigenetic cues of allergy/asthma risk. Next, we will assess composition/diversity of maternal gut, placenta, breastmilk and infant gut microbiome and their association with immunophenotype and biomarkers at birth, and clinical outcomes at age 1 and 2. Finally, we plan to assess how environmental exposures (perinatal outdoor and indoor pollution, allergens and endotoxin) affect the incidence of allergic sensitization, AD, FA, and risk of asthma.Discussion: The in-depth study of the ARIES birth cohort shall provide crucial information to understand the rising incidence of allergies and asthma in developing countries, and hopefully provide cues on how to prevent and treat these diseases.Trial Registration: clinicaltrials.gov NCT04186949, retrospectively registered on December 5, 2019. [ABSTRACT FROM AUTHOR]

Restricted episodic changes occurred in a short time period and over large spatial extents. Extreme weather conditions usually give rise to restricted episodic changes. Sentinel-1 radar images of the Salar de Aguas Calientes in Chile acquired in the Altiplanic winter (March 2015 and June 2017), 2018 austral winter and 2017–2018 springtime, demonstrates the ability to monitor episodic events remotely. The results of the backscattered power are encouraging and show episodic variations in VV polarization at C-band. The surface features in Salar de Aguas Calientes Sur change in response to snowfalls during either the Altiplanic or austral winter with an increase of the backscattering in presence of dry snow over the salt pan crust. Flooding events related to snow-melting during spring 2017–2018 showed a decrease in the backscattering signal over ponded water and an increase when wind blows over the water. Remote-sensing observations of the salar can provide a means for monitoring changes in the surface of the salar and a better understanding of the associated climatic episodic event processes. Furthermore, it can help to have a better understanding of environmental changes in arid regions and the understanding of global climate change. [ABSTRACT FROM AUTHOR]

This article addresses the experience, history, and particularities after the process of shaping Minga, an academic group of Organizational Studies in Chile. Following a historical-narrative methodology, a biographical account of this group is built, in which its protagonists participate as researchers and authors of the process. To analyze this story, a decolonial view is adopted, simultaneously investigating the leadership styles and the knowledge network that this experience mobilizes, paralleling the tradition of the minga chilota. The results show how the question for Organizational Studies in Chile coincides with a process of epistemic detachment from the global north, through which the collective and shared leadership among its members is consolidated in Minga, as well as its functioning as an inter-organizational academic network. The conclusions cover some of the learnings that the history and conformation of this group offer for other groups with similar intentions in the field of Organizational Studies in Latin America. [ABSTRACT FROM AUTHOR]

By exploring the emergence of new clusters, this paper departs from traditional research focused on established clusters and enriches recent studies on their development dynamics. The analysis of two successful clusters in Chile, one in agroindustry and the other in salmon aquaculture, highlights interactions between the state, local firms and multinationals, and the conditions enhancing collective firm learning. The argument is that the emergence of dynamic clusters depends on building institutions that enable coordinated learning among firms to improve capabilities processes and products. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to estimate asthma control at specialist treatment centers in four Latin American countries and assess factors influencing poor asthma control. Methods: Patients aged ≥12 years with an asthma diagnosis and asthma medication prescription, followed at outpatient specialist centers in Argentina, Chile, Colombia, and Mexico, were included. The study received all applicable ethical approvals. The Asthma Control Test (ACT) was used to classify patients as having controlled (ACT 20–25) or uncontrolled (ACT ≤19) asthma. Frequency and statistical tests were used to assess the association between hospital admissions/exacerbations/emergency department (ED) visits and uncontrolled asthma; multivariate logistic regression was used to assess the association of uncontrolled asthma with clinical/demographic variables. Results: A total of 594 patients were included. Overall controlled-asthma prevalence was 43.4% (95% confidence interval [CI]: 39.0, 47.4). Patients with uncontrolled asthma were more likely to be women (adjusted odds ratio [aOR]: 1.85; p = 0.003), non-white (aOR: 2.14; p < 0.001), obese (aOR: 1.71; p = 0.036), to have a low monthly family income (aOR: 1.75; p = 0.004), to have severe asthma (aOR:1.59; p = 0.26), and, compared with patients with controlled asthma, to have a higher likelihood of asthma exacerbations (34.5% vs. 15.9%; p < 0.001), hospital admissions (6.9% vs. 3.1%; p = 0.042), and ED visits (34.5% vs. 15.9%; p < 0.001) due to asthma. Conclusions: Even in specialist ambulatory services, fewer than half of patients were classified as having controlled asthma. The proportion of uncontrolled patients varied according to clinical and demographic variables. [ABSTRACT FROM AUTHOR]

Peatlands are characterized by their large carbon (C) storage capacity and represent important C sinks globally. In southern Chile, young peatlands (few centuries old) have originated due to clearcutting or fire at forest sites with high precipitation on poorly drained soils. These novel ecosystems are called anthropogenic peatlands here. Their role in the regional C cycle remains largely unknown. Here, we present 18 months of eddy covariance measurements of net ecosystem exchange (NEE) of carbon dioxide (CO2) in an anthropogenic peatland in northern Chiloé Island, part of which is kept undisturbed for 30–40 years, by excluding human uses, and another section of the same peatland that has been disturbed by cattle grazing and Sphagnum moss extraction. Gross primary productivity (GPP) and ecosystem respiration (Reco) were modeled from NEE, based on measured photosynthetically active radiation and air temperature, separately for each section of the peatland. Uncertainties of the annual flux estimates were assessed from the variability of modelled fluxes induced by applying different time-windows for model development between 10 and 20 days. The undisturbed area of the peatland was on average (± SD) a larger net CO2 sink (NEE = − 135 ± 267 g CO2 m−2 year−1) than the disturbed area (NEE = − 33 ± 111 g CO2 m−2 year−1). These NEE CO2 balances are small even though GPP and Reco were larger compared with other peatlands. Reco had a direct relationship with water table depth (from soil surface) and a negative relationship with soil water fraction. Our results show that the disturbance by moss extraction and cattle grazing is likely to reduce the CO2 sink function of many anthropogenic and natural peatlands on Chiloé Island, which are subjected to the same impacts. [ABSTRACT FROM AUTHOR]

We test the ability of Very High Resolution satellite (VHR) imagery to detect stranded whales using both manual and automated methods. We use the 2015 mass mortality event in the Gulf of Penas locality, central Patagonia, Chile, as an initial case study. This event was the largest known mass mortality of baleen whales, with at least 343 whales, mainly sei whales (Balaenoptera borealis), documented as stranding. However, even with such a large number of whales, due to the remote location of the gulf the strandings went unrecorded for several weeks. Aerial and boat surveys of the area were conducted two to four months after the mortality event. In this study we use 50cm resolution WorldView2 imagery to identify and count strandings from two archival images acquired just after the stranding event and two months before the aerial and ground surveys, and to test manual and automated methods of detecting stranded whales. Our findings show that whales are easily detected manually in the images but due to the heterogeneous colouration of decomposing whales, spectral indices are unsuitable for automatic detection. Our satellite counts suggest that, at the time the satellite images were taken, more whales were stranded than recorded in the aerial survey, possibly due to the non-comprehensive coverage of the aerial survey or movement of the carcases between survey acquisition. With even higher resolution imagery now available, satellite imagery may be a cost effective alternative to aerial surveys for future assessment of the extent of mass whale stranding events, especially in remote and inaccessible areas. [ABSTRACT FROM AUTHOR]

Mine operations in the future will require automatic rock characterization at many different stages, since it can be used to supervise and optimize various processes in the laboratory as well as at the mine locations for planning and exploitation. Different methods for classifying rocks based on image analysis have been proposed in the past. In this paper, we report the use of hyperspectral sensors in the classification of rock lithology. The lithology provides information about the chemical composition of the rock, and its physical properties. According to our literature review, this is the first time hyperspectral sensors have been employed in rock type classification. Additionally, it is the first time the use of three different technologies in rock type classification has been reported: hyperspectral sensors, laser range and a color camera. We use two hyperspectral sensors, one has sensibility within the visible and near-infrared range of 400–1000 nm, and the second has sensibility within the short-wavelength infrared range of 900–2500 nm. The range and high definition color images are used to perform accurate segmentation of the rock samples. Images are tessellated into sub-images in which various features from the three sensor types are extracted. In a first stage, the sub-images are classified by using a support-vector machine (SVM) classifier with the extracted features as inputs. In a second stage, the rock segmentation is used to perform a voting process among all the sub-images of each rock and improve the classification. The method was tested using a database with 13 lithologies from a copper mine in Chile. The results show that lithological classification performance obtained by using hyperspectral images greatly exceeds the performance of the color and range images. The achieved classification performance was 98.62% using sub-image classification and 99.95% using a voting process among sub-images. The number of features was also reduced by using the CMIM (Conditional Mutual Information Maximization) feature selection method, achieving a performance of over 99% with using only 3% of the total number of features. • High performance rock type classification is reached using hyperspectral images. • A classification performance of 99.95% is obtained with 13 different rock types. • Performance of over 99% is obtained by selecting only 3% of the features. • Classification by sub-images improved by a voting process inside each rock. [ABSTRACT FROM AUTHOR]

The quality and quantity of clozapine safety monitoring considerably differs among South American countries and mainly focus on hematological surveillance. Few studies have been conducted on other clozapine-related adverse effects (ADRs) and mainly refer to case reports and literature reviews. We retrieved thirty-nine publications on clozapine related ADRs others than neutropenia. Studies in Brazil and Venezuela accounted for 67 % of all the publications, and 8 out of 12 countries published 2 or less manuscripts. Only Chile offers serum clozapine level measurement in public institutions. Given the recently recognized role of ethnicity, gender, smoking, obesity drug interactions in optimal clozapine administration, modernization of clozapine clinical use and research in psychiatry and neurology most be broadcasted and stimulated in South American countries. [ABSTRACT FROM AUTHOR]

Copyright of Formación Universitaria is the property of Centro de Informacion Tecnologica (CIT) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The dramatic increase of microplastics (plastic fragments <5 mm) in marine environments is a problem that has attracted public attention globally. Within the different types of microplastics, microfibres are the least studied (size <1 mm). We examined 51 female scats from a population in Northern Patagonia. Our results showed no presence of microplastic particles, however 67% of them showed a remarkable abundance of microfibers, which until now had only been reported in animals fed in captivity. As a result of this work we propose that the examination of scats from South American Fur Seal and also other pinnipeds could be an efficient tool to monitor environmental levels of microfibres and maybe microplastics in the environment due to the easy recognition of the animals and their scats. Highlights • Fifty-one scats of females of American fur seal were sampled from a population in the Northern Patagonia. • 67% of samples showed the presence of microfibers, as the most relevant type of microplastic. • Pinniped scats could be a useful tool for environmental monitoring of microfibres and maybe microplastic particles levels. [ABSTRACT FROM AUTHOR]

The current paper describes Spanish acquisition of rhotic onset clusters. Data are also provided on related singleton taps/trills and /l/ as a singleton and in clusters. Participants included 9 typically developing (TD) toddlers and 30 TD preschoolers in Chile, and 30 TD preschoolers and 29 with protracted phonological development (PPD) in Granada, Spain. Results showed age and developmental group effects. Preservation of cluster timing units preceded segmental accuracy, especially in stressed syllables. Tap clusters versus singleton trills were variable in order of mastery, some children mastering clusters first, and others, the trill. Rhotics were acquired later than /l/. In early development, mismatches (errors) involved primarily deletion of taps; where substitutions occurred, [j] frequently replaced tap. In later development, [l] more frequently replaced tap; where taps did occur, vowel epenthesis sometimes occurred. The data serve as a criterion reference database for onset cluster acquisition in Chilean and Granada Spanish. [ABSTRACT FROM AUTHOR]

The article discusses the creation of Santiago Glaciers National Park in Chile, emphasizing the need to expand its protected area to safeguard biodiversity, water resources, and vulnerable species in the central region.

[Display omitted] • Ecological indicators of degradation were sampled in an altitudinal gradient of four mountain ecosystems. • Shrub cover and litter depth were selected as the best indicators of degradation. • Species indicating low degradation were consistently woody native species. • Process indicators showed more statistical differences when comparing ecosystems. • High degradation occurred when vegetation and process indicators changed ∼ 60% or when soil indicators changed ∼ 25%. Successful restoration measures need a good understanding of how the composition, structure, and functioning of ecosystems change with degradation and what the best indicators of these changes are. To answer these questions, we worked on four ecosystem types in the Mediterranean Andes mountains in central Chile (from sclerophyllous forest to Andean shrublands), which represent an elevational gradient from 700 to 3,250 m. We sampled three plots on each of the three degradation levels (low, medium, and high) for each ecosystem at increasing distances from goat corrals. We measured 35 indicators that describe vegetation (14), soil (15), and ecosystem processes (6) for one growing season. Degradation caused a decrease in shrub cover, shrub productivity, the Normalized Community Structure Integrity Index (CSII n), litter depth, total soil nitrogen and C/N ratio, and an increase in clay content. Plant species indicating low degradation were consistently native woody species. When comparing ecosystems (i.e., at different elevations) against the type of variable, process-based indicators showed more statistically significant differences. Based on their consistency across ecosystems and ease of measurement, we recommend using shrub cover and litter depth as indicators of degradation. Finally, we concluded that ecosystems are highly degraded when vegetation- and process-based indicators change ∼ 60% or when soil indicators change ∼ 25%. These results could also be used to set goals for restoration projects in these mountain ecosystems. [ABSTRACT FROM AUTHOR]

Global marine litter pollution is increasing dramatically, and oceanic islands are one of the most vulnerable ecosystems due to their high debris accumulation rate compared to continental sites. Remote areas, such as inhabited islands, represent a perfect study case to track marine debris sources, due to the assumed low rates of local production of debris. Guafo Island is one of the largest islands of the Chilean Northern Patagonia and is considered a remote zone. The accessible coast of Guafo Island was monitored during four austral summers revealing higher levels of marine debris accumulation than continental Chile. Plastic was the most abundant type of debris constituting 50% of the total litter monitored. Our results suggest that most of the plastic identified is likely to be related to local fisheries activities. Mitigation measures including collaboration among fishing communities and scientists could contribute to reduce the coastal debris pollution in remote areas. [ABSTRACT FROM AUTHOR]

Porcine reproductive and respiratory syndrome (PRRS) is endemic in most pork producing countries. In Chile, eradication of PRRS virus (PRRSV) was successfully achieved in 2009 as a result of the combined efforts of producers and the animal health authorities. In October 2013, after several years without detecting PRRSV under surveillance activities, suspected cases were confirmed on a commercial swine farm. Here, we describe the PRRS epidemic in Chile between October 2013 and April 2015, and we studied the origins and spread of PRRSV throughout the country using official surveillance data and Bayesian phylogenetic analysis. Our results indicate that the outbreaks were caused by a PRRSV closely related to viruses present in swine farms in North America, and different from the strain that circulated in the country before 2009. Using divergence time estimation analysis, we found that the 2013–2015 PRRSV may have been circulating in Chile for at least one month before the first detection. A single strain of PRRSV spread into a limited number of commercial and backyard swine farms. New infections in commercial systems have not been reported since October 2014, and eradication is underway by clearing the disease from the few commercial and backyard farms that remain positive. This is one of the few documented experiences of PRRSV introduction into a disease-free country. [ABSTRACT FROM AUTHOR]