Influencia del ph sobre el efecto tóxico inducido en clones de Dictyosphaerium Chlorelloides sensibles y resistentes a Cromo (VI)

El presente estudio establece una correlación entre las variaciones de pH en el medio y las concentraciones de Cromo (VI), mediante su efecto en poblaciones de Dictyosphaerium chlorelloides, microalgas eucariotas cosmopolitas de agua continental. Se cultivaron en medio BG11 dos clones de D. chlorelloides, uno sensible al Cr (VI) y otro resistente a concentraciones de 25 μg/ml, en un rango de pH entre 2,5 y 11 para determinar el efecto de la acidez. Habiendo establecido un rango de pH definitivo (3-7,5), realizamos los ensayos de toxicidad para obtener el valor de pH mínimo al que la población de microalgas no sufría variaciones estadísticamente significativas. El análisis de la exposición a Cr (VI) evidenció una NOEC ajustada al valor de pH=4,25 para ambos clones. Los valores de CI50(72) obtenidos a pH 7,5 y 4,25 evidenciaron variaciones estadísticamente significativas entre ambos valores de pH, no habiendo diferencias significativas relativas al crecimiento poblacional en la cepa sensible de D. chlorelloides, aunque sí en el clon resistente.This paper explains the relationship between the environmental variations of pH and Chromium (VI) concentration, by their effect on populations of Dictyosphaerium chlorelloides, eukaryotic cosmopolitan microalgae of fresh water ecosystems. Two strains of D. chlorelloides were cultured in BG11 culture medium, being one of them sensitive to Cr (VI) and the other one resistant up to concentrations of 25 μg/ml, at pH values between 2.5 and 11 in order to determine their viability. When the pH range was determined (3-7.5), toxicity assays were done to obtain the minimum value of pH in which the microalgal populations did not vary significantly. The analysis of Cr (VI) exposure demonstrated a NOEC fitted to the pH value of 4.25. The IC50(72) values obtained at pH 7.5 and 4.25 showed significant statistic variations between both pH values, and there were not significant differences related to community growth in the sensitive strain, unlike the resistant one

Influence of contaminant-spiked polyethylene-type microplastics on the growth and primary production of the freshwater phytoplankton species Scenedesmus armatus and Microcystis aeruginosa

Microplastic pollution and its ecological impact on the aquatic environment are a current focus of research in the scientific community. These microplastics may adsorb contaminants discharged into the aquatic environment, thereby serving as a sink and source for the dissemination of these associated chemical contaminants. However, knowledge about the potential risks of microplastics and associated chemical contaminants on aquatic biota, especially on primary freshwater producers, remains to be explored. In this study, the impact of a polyethylene microplastic type (MP) associated with amoxicillin, ibuprofen, sertraline and simazine (OCs) on the cell growth and photosynthetic activity of the green algae Scenedesmus armatus and the cyanobacteria Microcystis aeruginosa was evaluated after 28 days of exposure. The results show that all the organic contaminants and their respective MP-OC complexes induced stress on cell growth after 28 days of exposure, except when the cyanobacterial strain was exposed to amoxicillin and ibuprofen. Similarly, photosynthetic activity was affected by exposure to MP-OC complexes, with the most evident effect on cellular respiration in the cyanobacterial strain and on net photosynthesis in the green algae strain. Additionally, the ability of the M. aeruginosa strain to synthesize microcystin was significantly reduced. These results show that the formation of MP-OC complexes could reduce their adverse effects, although there is wide variability depending on both the type of organic contaminant and the photosynthetic organisms involved, so further studies are needed to better understand the interactions between these aquatic contaminants

Post-Franco Theatre

In the multiple realms and layers that comprise the contemporary Spanish theatrical landscape, “crisis” would seem to be the word that most often lingers in the air, as though it were a common mantra, ready to roll off the tongue of so many theatre professionals with such enormous ease, and even enthusiasm, that one is prompted to wonder whether it might indeed be a miracle that the contemporary technological revolution – coupled with perpetual quandaries concerning public and private funding for the arts – had not by now brought an end to the evolution of the oldest of live arts, or, at the very least, an end to drama as we know it

pollio

Pollio is the name of an otherwise unknown military office attested by a pair of military inscriptions and a fragment of Tarruntenius Paternus’ De re militari. Etymological connection with pullus and polia (stud of horses) is postulated, so that polliones could mean the grooms of the army.No disponible

Association between Post-Hospitalization Psychological Distress, Exercise Capacity, Physical Function and Health Status in COVID-19 Survivors

This study aims to determine whether post-hospitalization psychological distress is associated with exercise capacity, physical function and health status in COVID-19 survivors. In this observational study, hospitalized COVID patients were included and divided into two groups according to the mental component summary subscale of the 12-item Short-Form Health Survey. Patients with a score ≤ 45 were included in the psychological distress group, and patients with a score > 45 were included in the non-psychological distress group. The main variables were exercise capacity, physical function, and health status. Patients were evaluated at discharge, 3 months, and at 6 months follow-up. Finally, a total of 60 patients were included in the study. Significant differences were found in exercise capacity, physical function, and health status (p p < 0.05). It can be concluded that COVID patients with psychological distress at hospital discharge reported worse exercise capacity, physical function and health status at hospital discharge, 3 months and 6 months follow-up