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Climate change is one of the most important drivers of ecosystem change, the global-scale impacts of which will intensify over the next 2 decades. Estimating the timing of unprecedented changes is not only challenging but is of great importance for the development of ecosystem conservation guidelines. Time of emergence (ToE) (point at which climate change can be differentiated from a previous climate), a widely applied concept in climatology studies, provides a robust but unexplored approach for assessing the risk of ecosystem collapse, as described by the C criterion of the International Union for Conservation of Nature's Red List of Ecosystems (RLE). We identified 3 main theoretical considerations of ToE for RLE assessment (degree of stability, multifactorial instead of one-dimensional analyses, and hallmarks of ecosystem collapse) and 4 sources of uncertainty when applying ToE methodology (intermodel spread, historical reference period, consensus among variables, and consideration of different scenarios), which aims to avoid misuse and errors while promoting a proper application of the framework by scientists and practitioners. The incorporation of ToE for the RLE assessments adds important information for conservation priority setting that allows prediction of changes within and beyond the time frames proposed by the RLE.

Perspectivas sobre el momento del colapso ecosistémico en un clima cambiante Resumen El cambio climático es uno de los principales causantes del cambio ecosistémico, cuyo impacto a escala global se intensificará en las próximas dos décadas. No sólo es un reto estimar el momento de los cambios sin precedentes, sino también es de gran importancia para el desarrollo de las directrices de conservación de los ecosistemas. El momento de aparición (MdA), el punto en el que el cambio climático puede diferenciarse de un clima previo; es un concepto de aplicación extensa en los estudios de climatología y proporciona una estrategia sólida pero poco explorada para evaluar el riesgo del colapso ecosistémico, como está descrito por el criterio C de la Lista Roja de Ecosistemas (LRE) de la Unión Internacional para la Conservación de la Naturaleza. Identificamos las tres consideraciones teóricas del MdA para la evaluación de la LRE (grado de estabilidad, análisis multifactoriales en vez de unidimensionales y distintivos del colapso ecosistémico) y cuatro fuentes de incertidumbre cuando se aplica la metodología MdA (difusión intermodelo, periodo de referencia histórica, consenso entre las variables y consideración de escenarios distintos), la cual busca evitar el mal uso y los errores mientras se promueve una aplicación adecuada del marco de los científicos y lo practicantes. La incorporación del MdA a las evaluaciones de la LRE añade información importante para el establecimiento de prioridades de conservación que permiten la predicción de cambios dentro y más allá del marco temporal propuesto por la LRE.

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Although the abundance, survival, and pollination performance of honeybees are sensitive to changes in habitat and climate conditions, the processes by which these effects are transmitted to honey production and interact with beekeeping management are not completely understood. Climate change, habitat degradation, and beekeeping management affect honey yields, and may also interact among themselves resulting in indirect effects across spatial scales. We conducted a 2-year, multi-scale study on Chiloe Island (northern Patagonia), where we evaluated the most relevant environmental and management drivers of honey produced by stationary beekeepers. We found that the effects of microclimate, habitat, and management variables changed with the spatial scale. Among the environmental variables, minimum temperature, and cover of the invasive shrub, gorse (Ulex europaeus) had the strongest detrimental impacts on honey production at spatial scales finer than 4 km. Specialized beekeepers who adopted conventional beekeeping and had more mother colonies were more productive. Mean and minimum temperatures interacted with the percentage of mother colonies, urban cover, and beekeeping income. The gorse cover increased by the combination of high temperatures and the expansion of urban lands, while landscape attributes, such as Eucalyptus plantation cover, influenced beekeeping management. Results suggest that higher temperatures change the available forage or cause thermal stress to honeybees, while invasive shrubs are indicators of degraded habitats. Climate change and habitat degradation are two interrelated environmental phenomena whose effects on beekeeping can be mitigated through adaptive management and habitat restoration.

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Coastal wetlands are considered one of the most vulnerable ecosystems worldwide; the ecosystem services they provide and the conservation of their biodiversity are threatened. Despite the high ecological and socioenvironmental value of coastal wetlands, regional and national vulnerability assessments are scarce. In this study we aimed to assess the vulnerability of coastal wetlands in Chile from 18°S to 42°S (n = 757) under a multiscale approach that included drivers associated with climate change and land cover change. We assessed multiple drivers of vulnerability at three spatial scales (10 m, 100 m, and 500 m) by analyzing multiple remote sensing data (16 variables) on land cover change, wildfires, climatic variables, vegetation functional properties, water surface and importance for biodiversity. We constructed a multifactorial vulnerability index based on the variables analyzed, which provided a map of coastal wetland vulnerability. Then we explored the main drivers associated with the vulnerability of each coastal wetland by performing a Principal Components Analysis with Agglomerative Hierarchical Clustering, which allowed us to group coastal wetlands according to the drivers analyzed. We found that 42.6 ± 9.2 % of the coastal wetlands evaluated have high or very high vulnerability, with higher vulnerability at the 500 m scale (51.4 %). We identified four groups of coastal wetlands: two located in central Chile, mainly affected by climate change-associated drivers (41.9 ± 2.1 %), and one in central Chile which is affected by land cover change (52.8 ± 6.2 %); the latter has a lower vulnerability level. The most vulnerable coastal wetlands were located in central Chile. Our results present novel findings about the current vulnerability of coastal wetlands, which could be validated by governmental institutions in field campaigns. Finally, we believe that our methodological approach could be useful to generate similar assessments in other world zones.

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Evidence from preclinical and clinical studies demonstrate that pregnancy is a physiological state capable of modifying drug disposition. Factors including increased hepatic metabolism and renal excretion are responsible for impacting disposition, and the role of membrane transporters expressed in biological barriers, including the placental- and blood-brain barriers, has received considerable attention. In this regard, the brain disposition of drugs in the mother and fetus has been the subject of studies attempting to characterize the mechanisms by which pregnancy could alter the expression of ATP-binding cassette (ABC) and solute carrier (SLC) transporters. This chapter will summarize findings of the influence of pregnancy on the maternal and fetal expression of ABC and SLC transporters in the brain and the consequences of such changes on the disposition of therapeutic drugs.

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The effect of environmental and socioeconomic conditions on the global pandemic of COVID-19 had been widely studied, yet their influence during the early outbreak remains less explored. Unraveling these relationships represents a key knowledge to prevent potential outbreaks of similar pathogens in the future. This study aims to determine the influence of socioeconomic, infrastructure, air pollution, and weather variables on the relative risk of infection in the initial phase of the COVID-19 pandemic in China. A spatio-temporal Bayesian zero-inflated Poisson model is used to test for the effect of 13 socioeconomic, urban infrastructure, air pollution, and weather variables on the relative risk of COVID-19 disease in 122 cities of China. The results show that socioeconomic and urban infrastructure variables did not have a significant effect on the relative risk of COVID-19. Meanwhile, COVID-19 relative risk was negatively associated with temperature, wind speed, and carbon monoxide, while nitrous dioxide and the human modification index presented a positive effect. Pollution gases presented a marked variability during the study period, showing a decrease of CO. These findings suggest that controlling and monitoring urban emissions of pollutant gases is a key factor for the reduction of risk derived from COVID-19.

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Viral diseases jeopardize the health of wildlife in Chile. However, this country lacks health surveillance programs that allow for defining preventive measures to tackle such diseases. The objective of this study was to determine the occurrence and the genetic diversity of pestivirus, herpesvirus and adenovirus in pudus from Chile. Blood samples from wild (n=34) and captive (n=32) pudus were collected between 2011 and 2019 and analyzed through consensus PCR. All the samples were negative to pestivirus and adenovirus. Herpesvirus was confirmed in four captive, and one wild pudu. All four zoo animals share the same sequence for both polymerase and glycoprotein genes. Both sequences share a 100% identity with caprine herpesvirus-2, classifying them in the same cluster as the Macavirus group. In turn, novel sequences of the polymerase and glycoprotein B genes were obtained from the wild pudu. Our study reports the first evidence of CpHV-2 infection in Chile and South American ungulate populations. Further research will be necessary to assess the pathogenicity of CpHV-2 in this species. It is also urgently recommended that molecular, serological and pathological screening should be conducted in Chilean wild and captive pudus to understand the impact of the herpesvirus on their populations.

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Contrasting effects have been identified in association of weather (temperature and humidity) and pollutant gases with COVID-19 infection, which could be derived from the influence of lockdowns and season change. The influence of pollutant gases and climate during the initial phases of the pandemic, before the closures and the change of season in the northern hemisphere, is unknown. Here, we used a spatial-temporal Bayesian zero-inflated-Poisson model to test for short-term associations of weather and pollutant gases with the relative risk of COVID-19 disease in China (first outbreak) and the countries with more cases during the initial pandemic (the United States, Spain and Italy), considering also the effects of season and lockdown. We found contrasting association between pollutant gases and COVID-19 risk in the United States, Italy, and Spain, while in China it was negatively associated (except for SO2 ). COVID-19 risk was positively associated with specific humidity in all countries, while temperature presented a negative effect. Our findings showed that short-term associations of air pollutants with COVID-19 infection vary strongly between countries, while generalized effects of temperature (negative) and humidity (positive) with COVID-19 was found. Our results show novel information about the influence of pollution and weather on the initial outbreaks, which contribute to unravel the mechanisms during the beginning of the pandemic.

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Introduction: Herpesvirus infections have been highlighted as emerging diseases affecting wildlife health and the conservation of several taxa. Malignant catarrhal fever (MCF) and infectious keratoconjunctivitis (IKC) are two viruses that infect wild ruminants. Nevertheless, epidemiological data on herpesviruses in South American wild ruminants are limited. An outbreak of caprine gammaherpesvirus-2 (CpHV-2) that recently was suspected as the cause of MCF in southern pudus (Pudu puda) prompted the need to conduct molecular screenings in Chilean cervids to understand the epidemiology of herpesviruses. The aim of this study was to determine the occurrence and genetic diversity of herpesviruses in free-ranging cervids from Chile. Methods: Herpesvirus infection was assessed in antemortem blood samples (n = 86) from pudus (n = 81) and huemuls (Hippocamelus bisulcus) (n = 5), as well as postmortem samples of spleen (n = 24) and lung (n = 3) from pudus, using a nested pan-herpesvirus PCR assay. Results: Combining all suitable sample types, DNA of pudu gammaherpesvirus-1 was detected in five pudues and five huemuls, with an overall prevalence of 9.90% (n = 10/101; 95% CI = 5.11-17.87%). One pudu tested positive for ovine gammaherpesvirus-2 (n = 1/96; 1.04%; 95% CI = 0.05-6.49%), and one pudu tested positive for a Macavirus sequence with 98.63 similarity to ovine gammaherpesvirus-2 (n = 96; 1.04%; 95% CI = 0.05-6.49%). Discussion: To the best of our knowledge, this is the first report of a herpesvirus in huemul and of ovine gammaherpesvirus-2 in Chile. Our results also confirm the active circulation of herpesvirus in free-ranging cervids in Chilean Patagonia, and as such, MCF should be considered as a possible cause of disease in free-ranging Chilean pudus and livestock species. Further research is necessary to develop a plan of systematic monitoring (serological and pathological screening) of herpesviruses in Chilean wild and domestic ruminants to understand their diversity and impact on animal health and conservation.

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Headwaters represent an essential component of hydrological, ecological, and socioeconomical systems, by providing constant water streams to the complete basin. However, despite the high importance of headwaters, there is a lack of vulnerability assessments worldwide. Identifying headwaters and their vulnerability in a spatially explicit manner can enable restauration and conservation programs. In this study, we assess the vulnerability of headwaters in South-Central Chile (38.4 to 43.2°S) considering multiple degradation factors related to climate change and land cover change. We analyzed 2292 headwaters, characterizing multiple factors at five spatial scales by using remote sensing data related to Land Use and Cover Change (LUCC), human disturbances, vegetation cover, climate change, potential water demand, and physiography. We then generated an index of vulnerability by integrating all the analyzed variables, which allowed us to map the spatial distribution of headwater vulnerability. Finally, to estimate the main drivers of degradation, we performed a Principal Components Analysis with an Agglomerative Hierarchical Clustering, that allowed us to group headwaters according to the analyzed factors. The largest proportion of most vulnerable headwaters are located in the north of our study area with 48.1 %, 62.1 %, and 28.1 % of headwaters classified as highly vulnerable at 0, 10, and 30 m scale, respectively. The largest proportion of headwaters are affected by Climate Change (63.66 %) and LUCC (23.02 %) on average across all scales. However, we identified three clusters, in which the northern cluster is mainly affected by LUCC, while the Andean and Coastal clusters are mainly affected by climate change. Our results and methods present an informative picture of the current state of headwater vulnerability, identifying spatial patterns and drivers at multiple scales. We believe that the approach developed in this study could be useful for new studies in other zones of the world and can also promote Chilean headwater conservation.

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Disruption of the blood-brain barrier (BBB) is central in the pathophysiology of acute cerebral complications in women who have preeclampsia. Underling mechanisms are unclear. Using female human brain endothelial cells as an in vitro model of BBB, we show that plasma of women with preeclampsia increases cell apoptosis and permeability via activation of the vascular endothelial growth factor receptor 2 (VEGFR2). Since plasma of women with preeclampsia also enhanced VEGFR2 phosphorylation in the tyrosine 951 but decreased phosphorylation at the tyrosine 1175, we propose the former would be the more likely active form of VEGFR2 responsible for BBB alterations.

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