Temperature and precipitation biases in CORDEX RCM simulations over South America: possible origin and impacts on the regional climate change signal

Precipitation and temperature biases from a set of Regional Climate Models from the CORDEX initiative have been analysed to assess the extent to which the biases may impact the climate change signal. The analysis has been performed for the South American CORDEX domain. A large warm bias was found over central Argentina (CARG) for most models, mainly in the summer season. Results indicate that the possible origin of this bias is an overestimation of the incoming shortwave radiation, in agreement with an underestimation of the relative humidity at 850 hPa, a variable that could be used to diagnose cloudiness. Regarding precipitation, the largest biases were found during summertime over northeast of Brazil (NEB), where most models overestimate the precipitation, leading to wet biases over that region. This bias agrees with models’ underestimationof both the moisture flux convergence and the relative humidity at lower levels of the atmosphere. This outcome suggests that the generation of more clouds in the models may drive the wet bias over NEB. These systematic errors could affect the climate change signal, considering that these biases may not be stationary. For both CARG and NEB regions, models with higher warm biases project higher warming levels, mainly in the summer season. In addition, it was found that theserelationships are statistically significant with a confidence level of 95%, pointing out that biases are linearly linked with the climate change signal. For precipitation, the relationship between the biases and the projected precipitation changes is only statistically significant for the NEB region, where models with the largest wet biases present the greatest positive precipitation changes during the warm season. As in the case of biases, the analysis of the temperature and precipitation projections over some regions of South America suggests that clouds could affect them. The results found in this study point out that the analysis of the bias behaviour could help in a better interpretation of the climate change signal.Facultad de Ciencias Astronómicas y GeofísicasConsejo Nacional de Investigaciones Científicas y Técnica

Relationship between frontal systems and extreme precipitation over southern South America

The relationship between frontal systems and extreme precipitation events over southern South America is analyzed for the austral winter (May--August) and spring (September-December), on a 39-year period spanning from 1979 to 2017. Daily gridded data from the CPC Global Unified Precipitation dataset and the ERA5 reanalysis is employed. Fronts are identified by means of an objective front index (FI) that takes into account both dynamic (cyclonic vorticity) and thermodynamic (thermal contrast) characteristics. Extreme precipitation is characterized by the seasonal 95th percentile.Fronts occur in midlatitudes in about 10% of the days but there is a seasonal shift with larger occurrence frequencies located at southern latitudes in spring compared to winter. Front intensity-calculated as the seasonal mean of FI-is stronger in winter than in spring but the spatial pattern is similar on both seasons. Fronts explain about 50% of extreme precipitation on winter and 40% on spring; the percentage of total precipitation explained by fronts is lower but the spatial distribution is similar.Comparison between fronts that produce precipitation and the ones associated with extreme precipitation revealed that the latter are more intense on average. Fronts that produce extreme precipitation have a stronger dynamic forcing (i.e. higher cyclonic vorticity values) and a higher moisture availability (higher specific humidity anomaly). These two characteristics are the most promising for enhancing extreme precipitation events forecast.Facultad de Ciencias Astronómicas y GeofísicasConsejo Nacional de Investigaciones Científicas y Técnica

Five-year diagnostic stability among adolescents in an inpatient psychiatric unit

Introduction: In childhood, diagnoses made at the first admission to a psychiatric unit are frequently unstable and temporary. In this study, we examined the stability of DSM-IV-TR disorders and groups of disorders among adolescents followed-up for 5 years after hospitalization. Method: All inpatients admitted for the first time between 2007 and 2008 were included and contacted after 5 years for re-evaluation. The final sample comprised 72 patients. At admission, diagnoses were based on the DSM-IV-TR criteria, Fourth Edition. At five years, diagnoses were made using structured clinical interviews for DSM-IV axis I Disorders and for axis II (SCID-I and SCID-II) as well as the Personality Diagnostic Questionnaire, Fourth Edition (PDQ-4). We also evaluated and collected information on the global assessment of functioning using the World Health Organization Quality of Life-BREF (WHOQOL-BREF) instrument. Depending on the distribution of variables, we used the chi-squared and Fisher exact tests or the Student t and McNemar tests for statistical analyses. Results: The most stable diagnoses were schizophrenia spectrum disorders, bipolar disorder, generalized anxiety disorder, obsessive-compulsive disorder, attention deficit hyperactivity disorder, Tourette syndrome, and pervasive developmental disorder. The most unstable diagnoses were disruptive disorders. Participants were satisfied with their quality of life and the global outcomes of the sample were positive. Conclusion: Major psychiatric disorders, including mood and schizophrenia spectrum disorders, were significantly more stable than other diagnoses and tended to continue into adulthood. In the case of study participants, suffering a mental disorder during adolescence did not appear to affect global functioning outcomes

Evaluation of multiple downscaling tools for simulating extreme precipitation events over Southeastern South America: a case study approach

A collection of 10 high-impact extreme precipitation events occurring in Southeastern South America during the warm season has been analyzed using statistical (ESD) and dynamical downscaling approaches. Regional Climate Models from the CORDEX database for the South American domain at two horizontal resolutions, 50 km and 25 km, short-term simulationsat 20 km and at 4 km convective-permitting resolution and statistical downscaling techniques based on the analogue method and the generalized linear model approach were evaluated. The analysis includes observational datasets based on gridded data, station data and satellite products that allow assessing the observational uncertainty that characterizes extreme events in the region. It is found that the ability of the modelling strategies in capturing the main features of the extreme rainfall varies across the events. The higher the horizontal resolution of the models, the more intense and localized the core of the rainfall event, being the location of the exit region of the low-level jet and the low-level moisture flux convergence during the initial stages of the events the most relevant features that determine models? ability of capturing the location and intensity of the core of the heavy rainfall. ESD models based on the generalized linear approach overestimate the spatial extension of the events and underestimate the intensity of the local maxima. Weather-like convective-permitting simulations depict an overall good performance in reproducing both the rainfall patterns and the triggering mechanisms of the extreme events as expected, given that these simulations are strongly controlled by the initial conditions.Facultad de Ciencias Astronómicas y GeofísicasUniversidad de Buenos AiresConsejo Nacional de Investigaciones Científicas y Técnica

Pharmacological Elevation of Cellular Dihydrosphingomyelin Provides a Novel Antiviral Strategy against West Nile Virus Infection

The flavivirus life cycle is strictly dependent on cellular lipid metabolism. Polyphenols like gallic acid and its derivatives are promising lead compounds for new therapeutic agents as they can exert multiple pharmacological activities, including the alteration of lipid metabolism. The evaluation of our collection of polyphenols against West Nile virus (WNV), a representative medically relevant flavivirus, led to the identification of N,N'-(dodecane-1,12-diyl)bis(3,4,5-trihydroxybenzamide) and its 2,3,4-trihydroxybenzamide regioisomer as selective antivirals with low cytotoxicity and high antiviral activity (half-maximal effective concentrations [EC50s] of 2.2 and 0.24 μM, respectively, in Vero cells; EC50s of 2.2 and 1.9 μM, respectively, in SH-SY5Y cells). These polyphenols also inhibited the multiplication of other flaviviruses, namely, Usutu, dengue, and Zika viruses, exhibiting lower antiviral or negligible antiviral activity against other RNA viruses. The mechanism underlying their antiviral activity against WNV involved the alteration of sphingolipid metabolism. These compounds inhibited ceramide desaturase (Des1), promoting the accumulation of dihydrosphingomyelin (dhSM), a minor component of cellular sphingolipids with important roles in membrane properties. The addition of exogenous dhSM or Des1 blockage by using the reference inhibitor GT-11 {N-[(1R,2S)-2-hydroxy-1-hydroxymethyl-2-(2-tridecyl-1-cyclopropenyl)ethyl]octanamide} confirmed the involvement of this pathway in WNV infection. These results unveil the potential of novel antiviral strategies based on the modulation of the cellular levels of dhSM and Des1 activity for the control of flavivirus infection.We thank Theodore C. Pierson (National Institutes of Health, USA) for the subgenomic replicon of WNV. This work was supported by the Spanish Ministry of Science and Innovation AEI/10.13039/501100011033 under grants PID2019-105117RR-C21 (to M.A.M.-A.), PID2019-105117RR-C22 (to M.-J.P.-P.), and PID2020-119195RJ-I00 (to N.J.d.O.) and by the AECSIC under grant PIE-201980E100 (to M.-J.P.-P. and A.S.-F.). This research work was also funded by the European Commission-NextGenerationEU (regulation EU 2020/2094) through CSIC’s Global Health Platform (PTI Salud Global). P.M.-C. was supported by an FPI fellowship (PRE2020-093374) from AEI/10.13039/501100011033. The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.Peer reviewe

A primary healthcare information intervention for communicating cardiovascular risk to patients with poorly controlled hypertension: The Education and Coronary Risk Evaluation (Educore) study-A pragmatic, cluster-randomized trial

PURPOSE: Uncertainty exists regarding the best way to communicate cardiovascular risk (CVR) to patients, and it is unclear whether the comprehension and perception of CVR varies according to the format used. The aim of the present work was to determine whether a strategy designed for communicating CVR information to patients with poorly controlled high blood pressure (HBP), but with no background of cardiovascular disease, was more effective than usual care in the control of blood pressure (BP) over the course of a year. METHODS: A pragmatic, two-arm, cluster-randomized controlled trial was performed. Consecutive patients aged 40-65 years, all diagnosed with HBP in the last 12 months, and all of whom showed poor control of their condition (systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg), were recruited at 22 primary healthcare centres. Eleven centres were randomly assigned to the usual care arm, and 11 to the informative intervention arm (Educore arm). At the start of the study, the Educore arm subjects were shown the "low risk SCORE table", along with impacting images and information pamphlets encouraging the maintenance of good cardiovascular health. The main outcome variable measured was the control of HBP; the secondary outcome variables were SCORE table score, total plasma cholesterol concentration, use of tobacco, adherence to prescribed treatment, and quality of life. RESULTS: The study participants were 411 patients (185 in the Educore arm and 226 in the usual care arm). Multilevel logistic regression showed that, at 12 months, the Educore intervention achieved better control of HBP (OR = 1.57; 1.02 to 2.41). No statistically significant differences were seen between the two arms at 12 months with respect to the secondary outcomes. CONCLUSIONS: Compared to usual care, the Educore intervention was associated with better control of HBP after adjusting for age, baseline SBP and plasma cholesterol, at 12 months.This study was funded by the Spanish Ministry of Science and Innovation via the Instituto de Salud Carlos III, Subprograma de Proyectos de Investigación en Evaluación de Tecnologías Sanitarias y Servicios de Salud (PI 09/90354), and the Fundación de Investigación e Innovación Biomédica en Atención Primaria (FIIBAP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscriptS

Climate projections over South America using global climate models : Analysis of uncertainties

En esta tesis se analizan proyecciones climáticas sobre Sudamérica y sus incertidumbres asociadas utilizando modelos climáticos globales. Es ampliamente conocido que en los últimos años se ha producido un aumento en la temperatura del aire de superficie que no tiene registros históricos comparables y que además, se ha demostrado que ese incremento es debido al aumento antropogénico de los gases de efecto invernadero. Dicho incremento en la temperatura media global, trajo como consecuencias cambios en algunos patrones de circulación de gran escala y por lo tanto en otras variables atmosféricas. Según el último informe del IPCC (Intergovernmental Panel on Climate Change), dicho aumento va a seguir en las próximas décadas. Es por eso que en esta tesis se estudian cómo serán las proyecciones futuras a partir de experimentos del modelo climático global JMA/MRI (de alta resolución). Previo al estudio de las proyecciones futuras, se realizó una evaluación del clima presente, utilizando datos de estaciones meteorológicas, para identificar regiones en donde el modelo reproduce de manera adecuada los principales patrones de circulación, y los valores medios y la variabilidad de la temperatura y la precipitación. Es ampliamente conocido que las proyecciones climáticas del clima futuro generan incertidumbres que provienen de diferentes fuentes. Su importancia relativa puede cambiar debido al tiempo de proyección y a la variable, así como también a la escala (global o regional) en la cual se analizan dichas incertidumbres. Por lo tanto, en esta tesis se estudiarán además, las incertidumbres de las proyecciones del conjunto de modelos WCRP-CMIP3 y WCRP-CMIP5 con el objetivo de poder identificar las regiones en donde las proyecciones son más robustas.Climate projections over South America and their associated uncertainties using global climate models are analysed in this thesis. It is widely known that in recent years has been occurred an increment in the global air surface temperature that has no historical records. Besides it has been shown that this increment is due to increasing anthropogenic greenhouse gases. This increase in global average temperature, resulted in changes in some patterns of large-scale circulation and therefore in others atmosphere variables. According to the latest assessment report of IPCC (Intergovernmental Panel on Climate Change), this increase will continue in the coming decades. For this reason, this thesis studies how future projections will be, using experiments of the global climate model MRI/JMA (high-resolution), with emphasis in the southern part of South America. Prior to the study the future projections, there was a present climate assessment, using meteorological stations data, to identify areas where the model reproduces adequately the main patterns of atmospheric circulation, and the mean and variability of temperature and precipitation. It is widely known that climate projections generate uncertainties which come from different sources, and their relative importance may change due to time projection and the variable, as well as due to the scale (global or regional) in which these uncertainties are analysed. Therefore, this thesis examines the uncertainties of the projections of WCRPCMIP3 and WCRP-CMIP5 models in order to identify regions where the projections are more robust.Fil:Blázquez, Josefina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Relationship between frontal systems and extreme precipitation over southern South America

The relationship between frontal systems and extreme precipitation events over southern South America is analysed for the austral winter (May–August) and spring (September–December), on a 39-year period spanning from 1979 to 2017. Daily gridded data from the CPC Global Unified Precipitation dataset and the ERA5 reanalysis are employed. Fronts are identified by means of an objective front index (FI) that takes into account both dynamic (cyclonic vorticity) and thermodynamic (thermal contrast) characteristics. Extreme precipitation is characterized by the seasonal 95th percentile. Fronts occur in mid-latitudes in about 10% of the days but there is a seasonal shift with larger occurrence frequencies located at southern latitudes in spring compared to winter. Front intensity—calculated as the seasonal mean of FI—is stronger in winter than in spring but the spatial pattern is similar on both seasons. Fronts explain about 50% of extreme precipitation on winter and 40% on spring; the percentage of total precipitation explained by fronts is lower but the spatial distribution is similar. Comparison between fronts that produce precipitation and the ones associated with extreme precipitation revealed that the latter are more intense on average. Fronts that produce extreme precipitation have a stronger dynamic forcing (i.e., higher cyclonic vorticity values) and a higher moisture availability (higher specific humidity anomaly). These two characteristics are the most promising for enhancing extreme precipitation events forecast.Fil: Solari, Florencia Ilusión. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Blázquez, Josefina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Solman, Silvina Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmósfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmósfera; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Instituto Franco-Argentino sobre Estudios del Clima y sus Impactos; Argentin

The composition of West Nile virus lipid envelope unveils a role of sphingolipid metabolism in flavivirus biogenesis

© 2014, American Society for Microbiology. West Nile virus (WNV) is an emerging zoonotic mosquito-borne flavivirus responsible for outbreaks of febrile illness and meningoencephalitis. The replication of WNV takes place on virus-modified membranes from the endoplasmic reticulum of the host cell, and virions acquire their envelope by budding into this organelle. Consistent with this view, the cellular biology of this pathogen is intimately linked to modifications of the intracellular membranes, and the requirement for specific lipids, such as cholesterol and fatty acids, has been documented. In this study, we evaluated the impact of WNV infection on two important components of cellular membranes, glycerophospholipids and sphingolipids, by mass spectrometry of infected cells. A significant increase in the content of several glycerophospholipids (phosphatidylcholine, plasmalogens, and lysophospholipids) and sphingolipids (ceramide, dihydroceramide, and sphingomyelin) was noticed in WNV-infected cells, suggesting that these lipids have functional roles during WNV infection. Furthermore, the analysis of the lipid envelope of WNV virions and recombinant virus-like particles revealed that their envelopes had a unique composition. The envelopes were enriched in sphingolipids (sphingomyelin) and showed reduced levels of phosphatidylcholine, similar to sphingolipid-enriched lipid microdomains. Inhibition of neutral sphingomyelinase (which catalyzes the hydrolysis of sphingomyelin into ceramide) by either pharmacological approaches or small interfering RNA-mediated silencing reduced the release of flavivirus virions as well as virus-like particles, suggesting a role of sphingomyelin-to-ceramide conversion in flavivirus budding and confirming the importance of sphingolipids in the biogenesis of WNV.Fundacio la Marato de TV3Peer Reviewe