A genome-wide association study identifies novel players in Na and Fe homeostasis in Arabidopsis thaliana under alkaline-salinity stress.

In nature, multiple stress factors occur simultaneously. The screening of natural diversity panels and subsequent Genome-Wide Association Studies (GWAS) is a powerful approach to identify genetic components of various stress responses. Here, the nutritional status variation of a set of 270 natural accessions of Arabidopsis thaliana grown on a natural saline-carbonated soil is evaluated. We report significant natural variation on leaf Na (LNa) and Fe (LFe) concentrations in the studied accessions. Allelic variation in the NINJA and YUC8 genes is associated with LNa diversity, and variation in the ALA3 is associated with LFe diversity. The allelic variation detected in these three genes leads to changes in their mRNA expression and correlates with plant differential growth performance when plants are exposed to alkaline salinity treatment under hydroponic conditions. We propose that YUC8 and NINJA expression patters regulate auxin and jasmonic signaling pathways affecting plant tolerance to alkaline salinity. Finally, we describe an impairment in growth and leaf Fe acquisition associated with differences in root expression of ALA3, encoding a phospholipid translocase active in plasma membrane and the trans Golgi network which directly interacts with proteins essential for the trafficking of PIN auxin transporters, reinforcing the role of phytohormonal processes in regulating ion homeostasis under alkaline salinity.

Warmer night-time temperature promotes microbial heterotrophic activity and modifies stream sediment community.

Diel temperature patterns are changing because of global warming, with higher temperatures being predicted to be more pronounced at night. Biological reactions are temperature dependent, with some occurring only during the daylight hours (e.g., light photosynthesis) and other during the entire day (e.g., respiration). Consequently, we expect the modification of daily temperature cycles to alter microbial biological reactions in stream sediments. Here, we aimed to study the effect of warming and changes of the diel temperature patterns on stream sediment biofilm functions tied to organic carbon decomposition, as well as on biofilm meiofaunal community structure. We performed an eight-week experiment with 12 artificial streams subjected to three different diel temperature patterns: warming, warmer nights and control. Significant effects of warming on biofilm function and structure were mainly detected in the long term. Our results showed that warming altered biofilm function, especially in the warmer nights' treatment, which enhanced ß-glucosidase enzyme activity. Interestingly, clear opposite diel patterns were observed for dissolved organic carbon and ß-glucosidase activity, suggesting that, at night, sediment bacteria quickly consume the input of photosynthetic dissolved organic carbon labile compounds created during light-time. The biofilm structure was also altered by warming, as both warming and warmer night treatments enhanced copepod abundance and diminished abundances of turbellaria and nematodes, which, in turn, controlled bacterial, algal and ciliate communities. Overall, we conclude that warming has strong effect on sediment biofilm structure and enhanced microbial organic matter degradation which might, consequently, affect higher trophic levels and river carbon cycling.

Hidden drivers of low-dose pharmaceutical pollutant mixtures revealed by the novel GSA-QHTS screening method.

The ecological impacts of emerging pollutants such as pharmaceuticals are not well understood. The lack of experimental approaches for the identification of pollutant effects in realistic settings (that is, low doses, complex mixtures, and variable environmental conditions) supports the widespread perception that these effects are often unpredictable. To address this, we developed a novel screening method (GSA-QHTS) that couples the computational power of global sensitivity analysis (GSA) with the experimental efficiency of quantitative high-throughput screening (QHTS). We present a case study where GSA-QHTS allowed for the identification of the main pharmaceutical pollutants (and their interactions), driving biological effects of low-dose complex mixtures at the microbial population level. The QHTS experiments involved the integrated analysis of nearly 2700 observations from an array of 180 unique low-dose mixtures, representing the most complex and data-rich experimental mixture effect assessment of main pharmaceutical pollutants to date. An ecological scaling-up experiment confirmed that this subset of pollutants also affects typical freshwater microbial community assemblages. Contrary to our expectations and challenging established scientific opinion, the bioactivity of the mixtures was not predicted by the null mixture models, and the main drivers that were identified by GSA-QHTS were overlooked by the current effect assessment scheme. Our results suggest that current chemical effect assessment methods overlook a substantial number of ecologically dangerous chemical pollutants and introduce a new operational framework for their systematic identification.

Effects of flow intermittency and pharmaceutical exposure on the structure and metabolism of stream biofilms.

Increasing concentrations of pharmaceutical compounds occur in many rivers, but their environmental risk remains poorly studied in stream biofilms. Flow intermittency shapes the structure and functions of ecosystems, and may enhance their sensitivity to toxicants. This study evaluates the effects of a long-term exposure of biofilm communities to a mixture of pharmaceutical compounds at environmental concentrations on biofilm bioaccumulation capacity, the structure and metabolic processes of algae and bacteria communities, and how their potential effects were enhanced or not by the occurrence of flow intermittency. To assess the interaction between those two stressors, an experiment with artificial streams was performed. Stream biofilms were exposed to a mixture of pharmaceuticals, as well as to a short period of flow intermittency. Results indicate that biofilms were negatively affected by pharmaceuticals. The algal biomass and taxa richness decreased and unicellular green algae relatively increased. The structure of the bacterial (based on denaturing gradient gel electrophoresis of amplified 16S rRNA genes) changed and showed a reduction of the operational taxonomic units (OTUs) richness. Exposed biofilms showed higher rates of metabolic processes, such as primary production and community respiration, attributed to pharmaceuticals stimulated an increase of green algae and heterotrophs, respectively. Flow intermittency modulated the effects of chemicals on natural communities. The algal community became more sensitive to short-term exposure of pharmaceuticals (lower EC50 value) when exposed to water intermittency, indicating cumulative effects between the two assessed stressors. In contrast to algae, the bacterial community became less sensitive to short-term exposure of pharmaceuticals (higher EC50) when exposed to water intermittency, indicating co-tolerance phenomena. According to the observed effects, the environmental risk of pharmaceuticals in nature is high, but different depending on the flow regime, as well as the target organisms (autotrophs vs heterotrophs).

Pollution-induced community tolerance to non-steroidal anti-inflammatory drugs (NSAIDs) in fluvial biofilm communities affected by WWTP effluents.

We assessed the tolerance acquired by stream biofilms to two non-steroidal anti-inflammatory-drugs (NSAIDs), ibuprofen and diclofenac. Biofilms came from a stream system receiving the effluent of a wastewater treatment plant (WWTP). The response of biofilms from a non-polluted site (upstream the WWTP) was compared to that of others downstream with relevant and decreasing levels of NSAIDs. Experiments performed in the laboratory following the pollution-induced community tolerance (PICT) approach determined that both algae and microbial communities from biofilms of the sites exposed at the highest concentrations of ibuprofen and diclofenac acquired tolerance to the mixture of these NSAIDs occurring at the sites. It was also observed that the chronic pollution by the WWTP effluent affected the microbial metabolic profile, as well as the structure of the algal community. The low (at ng L(-1) level) but chronic inputs of pharmaceuticals to the river ecosystem result in tolerant communities of lower diversity and altered microbial metabolism.

[Monitoring a home care cohort]. / Seguimiento de una cohorte de atención domiciliaria.

OBJECTIVES: To evaluate home care by primary care teams for people over 65 years old with chronic conditions, in order to identify improvement opportunities. To identify patient and care variables associated with cognitive and functional impairment, nursing home admission, attendance at casualty units, hospital admission and death. DESIGN: Analytic study of the follow-up of a cohort for 3 years. SETTING: Primary health care teams in Catalonia, Spain. PATIENTS: One thousand three hundred patients over 65 with chronic pathologies and cared for by home care programmes in Catalonia. MAIN MEASUREMENTS: The following will be recorded annually: health status (Charlson, Barthel, Pfeiffer, Braden, and Gijón), data on the carer (Zarit), care received (social and health), self-perception of health (SF-12), Casualty attendance, short-term admissions and the final results, i.e. death or definitive admission to a nursing home or hospital. The statistical analyses will be based on logistic regression and a survival analysis. CONCLUSIONS: The study should reveal patient characteristics with prognostic value, as well as identify the social and health factors related to better survival and lower consumption of health and social resources.

Seguimiento de una cohorte de atención domiciliaria / Monitoring a home care cohort

Objetivo. Buscar oportunidades de mejora mediante la evaluación de la atención domiciliaria que ofrecen los equipos de atención primaria en nuestro entorno a las personas > 65 años de edad con enfermedades crónicas. Identificar cuáles son las variables del paciente y del servicio que recibe que se asocian con el deterioro funcional y cognitivo, ingreso en una residencia geriátrica, visita a urgencias, ingreso hospitalario o muerte. Diseño. Estudio analítico de seguimiento de una cohorte durante 3 años. Emplazamiento. Equipos de atención primaria de Cataluña. Participantes. En total, 1.300 pacientes > 65 años con enfermedades crónicas incluidos en el Programa de Atención Domiciliaria. Mediciones principales. Se recoge anualmente su estado de salud (Charlson, Barthel, Pfeiffer, Braden y Gijón), datos sobre el cuidador (Zarit), atenciones recibidas (social y sanitaria), salud subjetiva (SF-12), visitas a urgencias, ingresos temporales y el resultado final: muerte, ingreso en residencias geriátricas u hospital. Los análisis principales se basarán en regresiones logísticas y una análisis de supervivencia. Discusión. El estudio permitirá identificar las características del paciente que tengan valor pronóstico, así como conocer las prácticas de atención social y sanitaria que se asocian con una mejor supervivencia y un menor consumo de recursos sociosanitarios

Objectives. To evaluate home care by primary care teams for people over 65 years old with chronic conditions, in order to identify improvement opportunities. To identify patient and care variables associated with cognitive and functional impairment, nursing home admission, attendance at casualty units, hospital admission and death. Design. Analytic study of the follow-up of a cohort for 3 years. Setting. Primary health care teams in Catalonia, Spain. Patients. One thousand three hundred patients over 65 with chronic pathologies and cared for by home care programmes in Catalonia. Main measurements. The following will be recorded annually: health status (Charlson, Barthel, Pfeiffer, Braden, and Gijón), data on the carer (Zarit), care received (social and health), self-perception of health (SF-12), Casualty attendance, short-term admissions and the final results, i.e. death or definitive admission to a nursing home or hospital. The statistical analyses will be based on logistic regression and a survival analysis. Conclusions. The study should reveal patient characteristics with prognostic value, as well as identify the social and health factors related to better survival and lower consumption of health and social resources

Seguimiento de una cohorte de atención domiciliaria

Objetivo: Buscar oportunidades de mejora mediante la evaluación de la atención domiciliaria que ofrecen los equipos de atención primaria en nuestro entorno a las personas > 65 años de edad con enfermedades crónicas. Identificar cuáles son las variables del paciente y del servicio que recibe que se asocian con el deterioro funcional y cognitivo, ingreso en una residencia geriátrica, visita a urgencias, ingreso hospitalario o muerte. Diseño: Estudo analítico de seguimiento de una cohorte durante 3 años. Emplazamiento: Equipos de atención primaria de Cataluña. Participantes: En total, 1.300 pacientes > 65 años con enfermedades crónicas incluidos en el Programa de Atención Domiciliaria. Mediciones principales: Se recoge anualmente su estado de salud (Charlson, Barthel, Pfeiffer, Braden y Gijón), datos sobre el cuidador (Zarit), atenciones recibidas (social y sanitaria), sallud subjetiva (SF-12), visitas a urgencias, ingresos temporales y el resultado final: muerte, ingreso en residencias geriátricas u hospital. Los análisis principales se basarán e regresiones logísticas y una análisis de supervivencia. Discusión: El estudio permitirá identificar las características del paciente que tengan valor pronóstico, así como conocer las práticas de atención social y sanitaria que se asocian con una mejor supervivencia y un menor consumo de recursos sociosanitários(AU)