Universidad Mayor
  • Santiago, Chile
Recent publications
Context participation of runners in marathons increases each year, making them an attractive population to investigate. In Chile, the characteristics of marathoners in decentralized and emerging races, such as the Temuco Araucanía International Marathon (MITA), are not yet known. Objective to describe health profile, sociodemographic characteristics, and training habits of the 42K runners enrolled in MITA during the years 2017, 2018 and 2019. Methods Non-probabilistic convenience sample composed of people over 18 years of age, who signed informed consent. The data were obtained through a survey prepared by the authors, and were analyzed with the statistical program Stata 16.0 to describe the group based on the variables of health profile, sociodemographic characteristics and training habits. Results 135 adult marathoners were included (n=42-2017, n=45-2018, n=48-2019). The mean age was 39.5±9.1 years and 86.6% were men. Fifteen percent self-reported comorbidities, 96.7% were non-smokers, 80% were normal weight, 65% had a high educational level and 87% were workers. Regarding training habits, it is noteworthy that the frequency was 4.9±1 days per week, with a mean duration of 89±1 minutes per session. Finally, 71.9% of the sample reported doing high intensity training. Conclusions the MITA 42K runners are generally healthy subjects, nonsmokers and without comorbidities; mostly men, normal weight, middle age, with a high educational level and workers. They present a high frequency of weekly training, with an average duration of 90 minutes per session, this being carried out at high intensity by almost 2/3 of the sample. Knowledge of the health profile and training habits of runners is a first step to responsibly generate guidelines that contribute to strengthening the safe practice of this sport. Level of Evidence IV; Descriptive and Cross-Sectional Study. Keywords: Marathon Running; Sociodemographic Factors; Sports; Global Health
Context participation of runners in marathons increases each year, making them an attractive population to investigate. In Chile, the characteristics of marathoners in decentralized and emerging races, such as the Temuco Araucanía International Marathon (MITA), are not yet known. Objective to describe health profile, sociodemographic characteristics, and training habits of the 42K runners enrolled in MITA during the years 2017, 2018 and 2019. Methods Non-probabilistic convenience sample composed of people over 18 years of age, who signed informed consent. The data were obtained through a survey prepared by the authors, and were analyzed with the statistical program Stata 16.0 to describe the group based on the variables of health profile, sociodemographic characteristics and training habits. Results 135 adult marathoners were included (n=42-2017, n=45-2018, n=48-2019). The mean age was 39.5±9.1 years and 86.6% were men. Fifteen percent self-reported comorbidities, 96.7% were non-smokers, 80% were normal weight, 65% had a high educational level and 87% were workers. Regarding training habits, it is noteworthy that the frequency was 4.9±1 days per week, with a mean duration of 89±1 minutes per session. Finally, 71.9% of the sample reported doing high intensity training. Conclusions the MITA 42K runners are generally healthy subjects, nonsmokers and without comorbidities; mostly men, normal weight, middle age, with a high educational level and workers. They present a high frequency of weekly training, with an average duration of 90 minutes per session, this being carried out at high intensity by almost 2/3 of the sample. Knowledge of the health profile and training habits of runners is a first step to responsibly generate guidelines that contribute to strengthening the safe practice of this sport. Level of Evidence IV; Descriptive and Cross-Sectional Study. Keywords: Marathon Running; Sociodemographic Factors; Sports; Global Health
Biomass burning is common in much of the world, and in some areas, residential wood-burning has increased. However, air pollution resulting from biomass burning is an important public health problem. A sampling campaign was carried out between May 2017 and July 2018 in over 64 sites in four sessions, to develop a spatio-temporal land use regression (LUR) model for fine particulate matter (PM) and wood-burning tracers levoglucosan and soluble potassium (Ksol) in a city heavily impacted by wood-burning. The mean (sd) was 46.5 (37.4) μg m–3 for PM2.5, 0.607 (0.538) μg m–3 for levoglucosan, and 0.635 (0.489) μg m–3 for Ksol. LUR models for PM2.5, levoglucosan, and Ksol had a satisfactory performance (LOSOCV R2), explaining 88.8%, 87.4%, and 87.3% of the total variance, respectively. All models included sociodemographic predictors consistent with the pattern of use of wood-burning in homes. The models were applied to predict concentrations surfaces and to estimate exposures for an epidemiological study.
Vineyards started 20 years ago in Southern Chile, making viticulture a promising agricultural option for farmers in this area, increasing 7-fold during the last 5 years. However, vineyards of Southern Chile reach lower yields and lower sugar concentrations than those of the central zone, mainly due to the edaphoclimatic drivers such as low temperature, spring frost, and management constraints. Moreover, the impacts of climate change on rainfall have increased the water deficit in this area, mainly during grapevine phenological stages of high-water requirements (bloom, fruit set to veraison, and veraison to harvest). These antecedents support the urgency to validate strategies aimed at improving water use efficiency (WUE) of vineyards in Southern Chile through techniques such as the use of cover crops and regulated deficit irrigation (RDI). In addition, inter-row and intra-row cover crops can decrease both, plant water consumption and transpiration losses, as well as improve soil water infiltration. The high amount of winter rainfalls and fertility of soils in this zone, explaining also, the excessive vigor of vines, becomes possible through the adoption of these floor management techniques. Otherwise, RDI is currently proposed as a saving-water technique that controls vine vigor and increases fruit quality in vineyards. Nevertheless, currently, the findings are conflicting, and the most of studies have been performed in arid or semi-arid regions, but few in the neither Mediterranean nor humid regions such as those of Southern Chile. Therefore, according to the literature analyzed in zones with similar climatic conditions in Southern Chile, this review aimed to critically discuss how the strategies of cover crops and regulated deficit irrigation could improve the water use efficiency, vine balance, and enological properties in vineyards production of Southern Chile.
Modern humanity has changed the biosphere at a global scale, threatening its own sustainability. It is claimed that through technology humans maximize the extraction of energy from the natural system towards their own benefit, with rates of appropriation that surpass the time-scales for systemic adaptation. This time-decoupled coevolutionary dynamic is at the core of human societal unsustainability. Here, we developed in silico experiments of an open energy-based flowing network toy model of natural systems and study the effects that greedy evolutionary strategies, resembling human societal demands, have upon the performance and scarcity tolerance of the system. We aim to determine the flexibility that those biased evolutionary dynamics have for matching or surpassing natural evolution outcomes. We studied four different indexes of system’s growth and development (total system throughflow (TST), average mutual information, ascendency and entropy difference) and compare their scarcity tolerance and performance outcomes with respect to four different greedy scenarios. The results showed that greedy strategies rarely surpassed the tolerance and performance achieved by natural systemic evolution. The nature of the greedy scenarios developed were closely related to increases in TST and therefore, we emphasized this comparison. Here, the maximum percentage of greedy networks capable of surpassing natural dynamics was around one-third (approx. 35%). However, results suggest the existence of a space parameter where local increases of energy flow can outperform the outcomes of natural systemic evolution, but no evident network property seems to characterize those greedy networks. A mild inverse relationship was found between the number of links that greedy nodes have towards the output and their capacity to outpass the control evolution. As many of the human societal effect upon biospheric processes have dissipative byproducts, knowing that such dynamics might diminish the systems tolerance and performance suggest care in their (ab)use. This article is part of the theme issue ‘Evolution and sustainability: gathering the strands for an Anthropocene synthesis’.
We derive and analyse a model with unusual features characterizing human activities over the long-run. First, human population dynamics draw heavily on consumer–resource modelling in ecology in that humans must consume biological resources to produce new humans. Second, the model also draws heavily from economic growth theory in that humans do not simply consume biological resources; they also produce the resources they consume. Finally, humans use two types of technology. Consumption technology affects the rate at which humans can extract resources. Production technology controls how effectively humans convert labour into new resources. The dynamics of both types of technology are subject to cumulative cultural evolutionary processes that allow both technological progress and regress. The resulting model exhibits a wide range of dynamical regimes. That said, the system is routinely sensitive to initial conditions, with wildly different outcomes given the same parameter values. Moreover, the system exhibits a basic fragility in the sense that human activities often lead to the endogenous extinction of the human species. This can happen gently, or it can follow periods of explosive human activity with super-exponential growth that ends in collapse. This article is part of the theme issue ‘Evolution and sustainability: gathering the strands for an Anthropocene synthesis’.
How did human societies evolve to become a major force of global change? What dynamics can lead societies on a trajectory of global sustainability? The astonishing growth in human population, economic activity and environmental impact has brought these questions to the fore. This theme issue pulls together a variety of traditions that seek to address these questions using different theories and methods. In this Introduction, we review and organize the major strands of work on how the Anthropocene evolved, how evolutionary dynamics are influencing sustainability efforts today, and what principles, strategies and capacities will be important to guide us towards global sustainability in the future. We present a set of synthetic insights and highlight frontiers for future research efforts which could contribute to a consolidated synthesis. This article is part of the theme issue ‘Evolution and sustainability: gathering the strands for an Anthropocene synthesis’.
The great river systems originating from the Tibetan Plateau are pivotal for the wellbeing of more than half the global population. Our understanding of historical ranges and future changes in water availability for much of Southeast Asia is, however, limited by short observational records and complex environmental factors. Here we present annually resolved and absolutely dated tree ring-based streamflow reconstructions for the Mekong, Salween and Yarlung Tsangpo rivers since 1000 ce, which are supplemented by corresponding model projections until 2100 ce. We show a significant positive correlation between streamflow and dry season vegetation indices over the Indochinese Peninsula, revealing the importance of the Tibetan Water Tower for the functioning and productivity of ecological and societal systems in Southeast Asia. The streamflow variability is associated with low-frequency sea-surface temperature variability in the North Atlantic and North Pacific. We find that streamflow extremes coincide with distinct shifts in local populations that occurred during medieval times, including the occupation and subsequent collapse of Angkor Wat from the eleventh to the sixteenth century. Finally, our projections suggest that future streamflow changes will reach, or even exceed, historical ranges by the end of this century, posing unprecedented risks for Southeast Asia.
In a general optimized measurement scheme for discriminating between nonorthogonal quantum states, the error rate is minimized under the constraint of a fixed rate of inconclusive outcomes (FRIO). This so-called optimal FRIO measurement encompasses the standard and well-known minimum-error and optimal unambiguous (or maximum-confidence) discrimination strategies as particular cases. Here, we experimentally demonstrate the optimal FRIO discrimination between N=2,3,5, and 7 equally likely symmetric states of a qubit encoded in photonic path modes. Our implementation consists of applying a probabilistic quantum map which increases the distinguishability between the inputs in a controlled way, followed by a minimum-error measurement on the successfully transformed outputs. The results obtained corroborate this two-step approach and, in our experimental scheme, can be straightforwardly extended to higher dimensions. The optimized measurement demonstrated here will be useful for quantum communication scenarios where the error rate and inconclusive rate must be kept below the levels provided by the respective standard strategies.
Oxidative status and immune function are energy-demanding traits closely linked to diet composition, particularly resource availability and nutritional value. In seasonal environments, nutrient availability and diet quality fluctuate, potentially influencing these traits. However, limited evidence exists regarding these dietary effects on immune function in seasonal environments. In this study, we employed stable isotope analysis to assess the impact of seasonal changes in niche width and trophic level (i.e., δ¹⁵N) on two immune variables (hemolysis and hemagglutination scores) and two oxidative status parameters (lipid peroxidation and total antioxidant capacity) in three passerine species: Zonotrichia capensis (omnivorous), Troglodytes aedon (insectivorous), and Spinus barbatus (granivorous). We found that hemolysis scores varied seasonally in Z. capensis, with higher values in winter compared to summer. Total antioxidant capacity (TAC) also increased during the winter in Z. capensis and S. barbatus. The isotopic niche width for Z. capensis and S. barbatus was smaller in winter than in summer, with the omnivorous species exhibiting a decrease in δ¹⁵N. Despite the seasonal shifts in ecological and physiological traits in Z. capensis, we identified no correlation between immune response and TAC with trophic level. In contrast, in the granivorous S. barbatus, the lower trophic level resulted in an increase in TAC without affecting immunity. Our findings revealed that dietary shifts do not uniformly impact oxidative status and immune function across bird species, highlighting species-specific responses to seasonal changes. This underscores the importance of integrating ecological and evolutionary perspectives when examining how diet shapes avian immunity and oxidative balance.
Purpose of the review Sleep health is a commonly overlooked component of pediatric cardiometabolic risk. Disparities in sleep duration and meeting of pediatric sleep guidelines have been well documented among at-risk populations in the United States, including Latinos. However, sleep research often fails to describe or account for contextual and cultural factors impacting the ability for Latino families to meet guidelines. The current review focuses on recent findings related to measurement of sleep duration, understanding of contextual factors that impact sleep hygiene, and interventions designed to increase sleep duration and quality among U.S. Latino families with infants, young children, and adolescents. Recent findings Ten studies focusing on sleep health in U.S. Latino children, using different study designs were identified. Overall, cross-sectional studies confirmed inadequate sleep among Latino children, intervention studies demonstrated promise of culturally-sensitive health behavior education for improving sleep in early childhood, and qualitative studies highlighted neighborhood and cultural factors that impact sleep quality. Implications for clinical practice and research Rather than new prevalence studies on adherence to sleep recommendations among Latino families, research focusing on adapting clinical guidelines to accommodate the realities of many Latino families (e.g., co-sleeping and bedsharing) will advance our knowledge. A shift towards objective measurement of the 24-h period as well as evaluating specific contextual barriers that make It challenging to meet sleep guidelines for Latino children is needed.
The temperature dependence of the zero-field splitting (ZFS) between the |ms=0〉 and |ms=±1〉 levels of the nitrogen-vacancy (NV) center's electronic ground-state spin triplet can be used as a robust nanoscale thermometer in a broad range of environments. However, despite numerous measurements of this dependence in different temperature ranges, to our knowledge no analytical expression has been put forward that captures the scaling of the ZFS of the NV center across all relevant temperatures. Here we present a simple, analytical, and physically motivated expression for the temperature dependence of the NV center's ZFS that matches all experimental observations, in which the ZFS shifts in proportion to the occupation numbers of two representative phonon modes. In contrast to prior models our expression does not diverge outside the regions of fitting. We show that our model quantitatively matches experimental measurements of the ZFS from 15 to 500 K in single NV centers in ultrapure bulk diamond, and we compare our model and measurements to prior models and experimental data.
There is no doubt that nowadays, the use of smartphones for communication between two or more entities through instant messaging applications has become a trend model in our society. New messaging applications started to emerge and try to replace traditional SMS. In fact, they have become the main communication route, and it is almost impossible to find someone who does not use at least one of these kinds of messaging applications. However, building them with security and privacy in mind of developers was not important in the beginning. In other words, when the popular messaging applications were created, they did not support end-to-end encryption, only standard client-to-server encryption, which gave the service providers access to more private information than necessary. Additionally, information that is exchanged in such instant messaging applications has the characteristic to be sensible that results in the necessity to achieve security services associated with users information, by achieving confidentiality, integrity, and authenticity in sent and received messages. In this article, we present a security verification on the Signal and MTProto 2.0 cryptographic protocols, which are contained in the most commonly used instant messaging applications. The security verification is made by using automatic verification tools and obtained results show that the protocols are flawless in terms of their construction, message delivery logic, and semantics. In other words, they are safe from attacks that automatic protocol verification tools check for.
Nowadays, depth maps are a crucial source of information for many applications based on artificial vision. Applications such as video games, 3D cinema, or unmanned autonomous vehicle control strongly depend on data extracted from depth maps. Depth maps can be estimated by algorithms or acquired by sensors (such as Kinect sensor, Time-of-Flight camera, or LiDAR sensor). Acquired depth data frequently contains holes or data with low confidence levels. An interpolation model is necessary to solve the problem of lack of data or complete these holes in depth maps. We constructed a manifold given the image domain and a metric whose parameters are learned from the data. The primary approach is to provide the parameterized metric enough flexibility to estimate the manifold’s shape correctly. Additionally, the proposal embedded depth estimation in a pipeline considering convolution stages and the anisotropic metric. We estimated the parameters’ proposal using the PSO algorithm. We assessed our proposal using the publicly available KITTI Depth Completion Suite dataset. Obtained results show that this proposal outperforms our previous implementation and other contemporary models. Additionally, we performed an ablation study of the model showing that the critical component of the model is the first convolution stage, meaning this stage that enforces the edges of the color image is a crucial component of the model.
A total of nine small wild felid species can be found in a diversity of habitats in South America. Hierarchical models (HM) can be used to estimate key population aspects such as their distribution, abundance, density, and the influence of environmental conditions. The HM framework can accommodate errors introduced during the observation process, separating them from the ecological process that is key to informing conservation actions. In this chapter, we review studies on small wild felids of South America that estimate abundance, density, and occupancy using HM. We quantify the number of studies per species and ecoregions, as well as assess survey effort, parameter estimates, and their precision. We also qualitatively summarize conservation recommendations arrived at directly from HM results. Based on a priori inclusion criteria, we reviewed 81 studies published between 2002 and 2022. The most widely used detection method was camera-trapping. By 2015, occupancy studies had surpassed those of density and abundance in terms of the relative number of publications. The species with the highest number of studies was the ocelot (Leopardus pardalis; n = 49), and the ones with the least were the Andean cat (L. jacobita) and southern tigrina (L. guttulus) (n = 3 each). L. pardalis also dominated HM application in terms of cumulative survey effort (>2 million trap nights). The ocelot showed the broadest range of density estimates and SE values on density and occupancy. The low precision of model estimates but relatively large survey effort for some species suggests the need for more species-specific survey designs (e.g., H. yagouaroundi and L. wiedii). Conservation recommendations based on the results of HM studies suggest mitigating impacts in three main dimensions: habitat degradation, direct human pressures, and impacts of both native and domestic carnivores. Priority use of HM should be given to species such as Herpailurus yagouaroundi, L. guttulus, L. colocolo complex, and L. jacobita, as well as geographical areas for which there are research gaps in demographic parameters.
The rewilding of modern agriculture is challenged by our current uncertainties on the microbiome of major crop wild progenitors (CWPs). Here, we conducted the first global standardised field survey to investigate the edaphoclimatic conditions and soil microbiome of 125 wild populations associated with 10 of the most important CWPs at their centres of origin. The wild populations clustered into four ecoregions, ranging from deserts to tropical seasonal forests and savannas, shaped by two edaphoclimatic dimensions that distinguished areas with high soil sand contents and scarce micronutrients from the more fertile ecoregions characterised by variations in aridity, soil pH and carbon storage potential. We identified a common soil core microbiome with differentiated assemblages across ecoregions, driven by varying environmental preferences among soil biodiversity kingdoms, which reflects potential shifts in their functional profiles. The CWPs created unique microhabitats within ecoregions that strongly influenced the soil community assembly, indicating specific co-evolutionary interactions. These insights into the evolutionary origins of domesticated crops hold the potential to advance microbial-assisted breeding and microbiome rewilding of croplands across the globe.
Some patients with autism and severe intellectual disability may experience uncontrolled aggression, causing serious injury or harm to others, and the therapeutic ineffectiveness of traditional pharmacological and behavioral treatment may aggravate symptoms. Deep brain stimulation (DBS) has been tested in patients with little evidence in children and adolescents. Therefore, we analyzed the efficacy and safety of DBS in refractory aggression in pediatric subjects with autism (ASD) and severe intelligence deficit (ID). Methods: A meta-analytic review of Web of Science (WOS) and Scopus articles, following Prisma criteria. A total of 555 articles were identified, but after applying the inclusion criteria, only 18 were analyzed. The review of the registries and the extraction of information was performed by 2 independent groups, to reduce the evaluator's bias. For the description of the results, pediatric patients with ASD or ID present in each registry, with an application of specialized scales (Overt aggression scale, OAS, and THE modified version of the OAS, MOAS) pre and post-DBS, with a clinical follow-up of at least 12 months, were considered valid. Clinical improvement was calculated using tests of aggressiveness. In each registry with available data and then pooling the means of all patients in the OAS and MOAS, the effect size of DBS (overall and per study) was estimated. Finally, the adapted NOS scale was applied to rate the studies' quality and level of bias. Results: In the studies analyzed, 65/100 were pediatric patients, with a mean age of 16.8 years. Most of the studies were conducted in South America and Europe. In all teams, aggressive behavior was intractable, but only 9 groups (53/65) applied specialized scales to measure aggressiveness, and of these, only 51 subjects had a follow-up of at least 12 months. Thus, in 48/51 a clinical improvement of patients was estimated (94.2%), with a considerable overall effect size (OAS: d=4.32; MOAS: d=1.46). However, adverse effects and complications were found in 13/65 subjects undergoing DBS. The brain target with the most evidence and the fewest side effects was the posteromedial hypothalamic nuclei (pHypN). Finally, applying the adapted NOS scale, quality, and bias, only 9 studies show the best indicators. Conclusion: An optimal level of efficacy was found in only half of the publications. This is mainly due to design errors and irrelevant information in the reports. We believe that DBS in intractable aggressiveness in children and adolescents with ASD and severe ID can be safe and effective if working groups apply rigorous criteria for patient selection, interdisciplinary assessments, objective scales for aggressiveness, and known surgical targets.
Alternative processing of nascent mRNAs is widespread in eukaryotic organisms and greatly impacts the output of gene expression. Specifically, alternative cleavage and polyadenylation (APA) is a co- transcriptional molecular process that switches the polyadenylation site (PAS) at which a nascent mRNA is cleaved, resulting in mRNA isoforms with different 3’UTR length and content. APA can potentially affect mRNA translation efficiency, localization, stability, and mRNA seeded protein–protein interactions. APA naturally occurs during development and cellular differentiation, with around 70% of human genes displaying APA in particular tissues and cell types. For example, neurons tend to express mRNAs with long 3’UTRs due to preferential processing at PASs more distal than other PASs used in other cell types. In addition, changes in APA mark a variety of pathological states, including many types of cancer, in which mRNAs are preferentially cleaved at more proximal PASs, causing expression of mRNA isoforms with short 3’UTRs. Although APA has been widely reported, both the function of APA in development and the mechanisms that regulate the choice of 3’end cut sites in normal and pathogenic conditions are still poorly understood. In this review, we summarize current understanding of how APA is regulated during development and cellular differentiation and how the resulting change in 3’UTR content affects multiple aspects of gene expression. With APA being a widespread phenomenon, the advent of cutting-edge scientific techniques and the pressing need for in-vivo studies, there has never been a better time to delve into the intricate mechanisms of alternative cleavage and polyadenylation.
The stability of isolated communities is determined by foodweb complexity.However, it is unclear how local stability interacts with dispersal in multitrophic metacommunities to shape biodiversity patterns. Furthermore, metacommunity dynamics in landscapes with non-trivial and dynamic structures are less understood. vspace{8pt}\newlineObjectives: We aim to evaluate the influence of local stabilizing factors versus dispersalin determining the sensitivity of metacommunity biodiversity to increasing site availabilityasynchrony. Additionally, we assess the role of foodweb complexity and landscapestructure as modulating factors. vspace{8pt}\newlineMethods: We developed a model based on random matrices for local communities, which are linked by stochastic dispersal over explicit dynamic landscapes. We ran numerical simulations and computed the effect sizes of foodweb temperature, self-limitation, dispersal ability, and all pairwise combinations, on the sensitivity of biodiversity to landscape asynchrony. We explored gradients of species richness, foodweb connectance, number of sites, and landscape modularity. Asynchrony among site availability periods reduced \(\alpha\)-diversity and rose \(\beta\)-diversity. Asynchrony increased \(\gamma\)-diversity at high dispersal rates. Bothlocal and regional stabilizing factors determined the sensitivity of metacommunities to land-scape asynchrony. Local factors were more influential in landscapes with fewer sites andlower modularity. Local factors were particularly influential in metacommunities composed of complex foodwebs. This research offers insights into the dynamics of metacommunitiesin dynamic landscapes, providing valuable knowledge about the interplay between local andregional factors in shaping ecological stability and species persistence. We delve into themechanisms underlying our results and discuss potential extensions of our study.
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Ute Woehlbier
  • Center of Integrative Biology
Esteban Calvo
  • Society and Health Research Center
Juan Pablo Cárdenas
  • Centro de Genómica y Bioinformática
Raúl Ugalde
  • Escuela de Geología
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