Survival of Ceriodaphnia dubia (Crustacea, Cladocera) exposed to different screens against natural ultraviolet radiation

The current increase of penetration of natural ultraviolet radiation (UVR) in southern South America affects water bodies because the UVR can penetrate the water column. In this scenario, the zooplankton develops photoprotective strategies such as vertical migrations against UVR or synthesis of photoprotective substances. The present study was done using a population of Ceriodaphnia dubia. That was collected from small shallow wetland near Temuco, Chile. The specimens were exposed for 7 to 9 hours to natural ultraviolet radiation, and with different colored nylon as protection against UVR, the experiment was done during the southern summer of 2006. The results revealed that in the presence of protection against UVR provided by colored nylon, the mortality was low, whereas under exposure to UVR and covering by transparent nylon total mortality was observed. The relation between mortality and the dose of UV that can penetrate the different colored nylon is represented by LC50 in UV (280-400 nm) and UVB (280-320 nm), within intensities of 234.82 and 14.96 kJ/m2, respectively

Analysis of O.Oeni proteome

Comunicaciones a congreso

Software didáctico para enseñanza de colores usado en niños menores de cinco años

In the first school levels, audiovisual material is important to conceptualize different learning processes for example in the color’s learning path. This article shows a software for the learning process for children under the age of five years, through an interactive interface which stimulates the kid by assigning a color to the image sections according to their own knowledge. The software is able to tell the chosen color by using an audible note, with the purpose of the child repeating the process over and over again, he slowly remembers each color that he has seen in the images, and he uses such knowledge in his environment recognition. In the investigation development some tests are applied to children from the institution Fundación San Lorenzo (Ciudad Bolivar, Colombia)  with positive results that are reflected in their learning processes, to a 9,12\% compared to their initial perception.En los primeros niveles escolares, el material audiovisual es importante para conceptualizar diferentes procesos de aprendizaje, como por ejemplo el de los colores. El presente artículo muestra un software para el aprendizaje de los niños menores de cinco años, por medio de una interfaz interactiva, que estimula al infante a atribuir un color a las secciones de la imagen de acuerdo a su conocimiento. El software tiene la capacidad de indicarle el color escogido mediante una nota audible, esto con el fin de que al hacer repetitivamente el proceso, el niño recuerde cada uno de los colores vistos en las imágenes, y que dicho conocimiento lo emplee en el reconocimiento de su entorno. En el desarrollo de la investigación se aplican pruebas a niños de la Fundación San Lorenzo (Ciudad Bolívar, Colombia) con resultados positivos que se reflejan en su proceso de aprendizaje, hasta en un 9,12% con respecto a su percepción inicial

Exploring ionic liquids based on pyrrolidinium and imidazolium cations with low toxicity towards Escherichia coli for designing sustainable bioprocesses

Ionic liquids (ILs) are widely applied in many bioprocesses involving microorganisms due to their unique properties. In this work, the toxicity of imidazolium and pyrrolidinium ionic liquids towards E. coli., a bacterium for which there are limited toxicity data in the literature, was determined. For its simplicity, the nephelometry method was used to estimate ionic liquid toxicity values. The influence of the cation and the alkyl chain length of the cation and anion was analysed. Pyrrolidinium cations were seen to be less toxic than imidazolium cations, while an increase in the alkyl chain length of both pyrrolidinium and imidazolium cations increased the toxicity. Among the anions studied, dimethylphosphate ([Me2PO4]) was the less toxic, while the EC50 for the ionic liquid 1-butyl-3-methylpyrrolidinium dimethylphosphate ([C1C4Pyr][Me2PO4]) was close to 200 mM. Furthermore, a dicationic ionic liquid based on imidazolium and pyrrolidinium cations was synthetized and its toxicity toward E. coli was analysed, maintaining a growth rate of 100% in the range 0-0.76 mM. The methodology used in this work allows to easily find the less toxic ionic liquids that are biocompatible with E. coli to be used in new bioprocesses

Biodisponibilidad de plomo y cadmio en sedimentos dragados del río Matanza y evaluación de métodos geoquímicos para su estimación

p.49-55En este trabajo se determinó la biodisponibilidad de cadmio y plomo en sedimentos dragados del río Matanza midiendo la acumulación de estos metales en los tejidos de la lombriz Eisenia foetida. Se evaluó la aplicación de métodos simples de extracción de cadmio y plomo, como medidas indirectas de su biodisponibilidad. La concentración de ambos metales aumentó en los tejidos de Eisenia fetida acorde con las mayores concentraciones en el sedimento; sin embargo, los coeficientes de bioacumulación sólo fueron mayores que la unidad para los tratamientos con adición de 5, 10 y 25 mg de Cd/kg de sedimento. El fraccionamiento de los metales por el método de Tessier mostró que la principal forma de cadmio presente en el sedimento fue la intercambiable para todos los tratamientos, mientras que las formas de plomo, variaron según la dosis del metal agregada. Las concentraciones de los metales extractados del sedimento con MgCi2, EDTA y DTPA se relacionaron con la bioacumulación en los tejidos de Eisenia ferida, indicando que pueden utilizarse como indicadores de la fracción biodisponible de Cd y Pb en los sedimentos

Ecological structure of aquatic macroinvertebrate communities in the Hauts Plateaux of Northeast Algeria

Abstract Aquatic macroinvertebrates are integral parts of functioning wetlands, inhabiting a diversity of aquatic ecosystems where communities are spatially structured. Macroinvertebrates of some Mediterranean regions such as North Africa are still not well studied. Here, we study the community structure of benthic macroinvertebrates in four different types of lotic and lentic wetlands in the semiarid Haut Plateaux of Northeast Algeria. Macroinvertebrates and 06 physicochemical parameters were sampled in 12 sites belonging to four types of habitats (lotic river, lentic river, dams, and sebkha [saline lentic water body]) during January-December 2021. Eventually, the character lentic-lotic was the most important variable affecting the affecting invertebrate communities in the Mediterranean region. The results revealed that sebkha and dams had a lower Shannon index than lentic and lotic rivers. Non-metric multidimensional scaling analysis showed a strong overlap between the community composition in lotic and lentic sites . Howeverin the three types of aquatic groups lentic river, dam and lotic habitats showed a strong overlap between the community whereas sebkha was markedly separated. Redundancy analysis showed that water velocity and pH, were the main drivers of community structure of macroinvertebrates, revealed a strong effect with pH (F1,8=4.15, P = 0.001) and water velocity (F1,8= 3.22, P = 0.002) , separating lotic communities from those that inhabited dams, lentic rivers, and sebkhas. As conclusion, this study contributes to the better understanding of the community structure of macroinvertebrates in semiarid North Africa where wetlands have been experiencing high anthropogenic disturbance

AKT inhibition impairs PCNA ubiquitylation and triggers synthetic lethality in homologous recombination-deficient cells submitted to replication stress

Translesion DNA synthesis (TLS) and homologous recombination (HR) cooperate during S-phase to safeguard replication forks integrity. Thus, the inhibition of TLS becomes a promising point of therapeutic intervention in HR-deficient cancers, where TLS impairment might trigger synthetic lethality (SL). The main limitation to test this hypothesis is the current lack of selective pharmacological inhibitors of TLS. Herein, we developed a miniaturized screening assay to identify inhibitors of PCNA ubiquitylation, a key post-translational modification required for efficient TLS activation. After screening a library of 627 kinase inhibitors, we found that targeting the pro-survival kinase AKT leads to strong impairment of PCNA ubiquitylation. Mechanistically, we found that AKT-mediated modulation of Proliferating Cell Nuclear Antigen (PCNA) ubiquitylation after UV requires the upstream activity of DNA PKcs, without affecting PCNA ubiquitylation levels in unperturbed cells. Moreover, we confirmed that persistent AKT inhibition blocks the recruitment of TLS polymerases to sites of DNA damage and impairs DNA replication forks processivity after UV irradiation, leading to increased DNA replication stress and cell death. Remarkably, when we compared the differential survival of HR-proficient vs HR-deficient cells, we found that the combination of UV irradiation and AKT inhibition leads to robust SL induction in HR-deficient cells. We link this phenotype to AKT ability to inhibit PCNA ubiquitylation, since the targeted knockdown of PCNA E3-ligase (RAD18) and a non-ubiquitylable (PCNA K164R) knock-in model recapitulate the observed SL induction. Collectively, this work identifies AKT as a novel regulator of PCNA ubiquitylation and provides the proof-of-concept of inhibiting TLS as a therapeutic approach to selectively kill HR-deficient cells submitted to replication stress.Fil: Villafañez, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: García, Iris Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Carbajosa González, Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Pansa, Maria Florencia. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mansilla, Sabrina Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Llorens de Los Ríos, María Candelaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Angiolini, Virginia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones y Transferencia de Villa María. Universidad Nacional de Villa María. Centro de Investigaciones y Transferencia de Villa María; ArgentinaFil: Guantay, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Jacobs, Heinz. Tumor Biology And Immunology-netherlands Cancer Institu; Países BajosFil: Madauss, Kevin P.. Glaxosmithkline; Reino UnidoFil: Gloger, Israel. Glaxosmithkline; Reino UnidoFil: Gottifredi, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Bocco, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Soria, Ramiro Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin