Volume expansion of erythrocytes is not the only mechanism responsible for the protection by arginine-based surfactants against hypotonic hemolysis

A novel arginine-based cationic surfactant Nα-benzoyl-arginine dodecylamide (Bz-Arg-NHC12) was synthesized in our laboratory. In this paper we study the interaction of Bz-Arg-NHC12 with sheep and human red blood cells (SRBC and HRBC respectively) due to their different membrane physicochemical/biophysical properties. SRBC demonstrated to be slightly more resistant than HRBC to the hemolytic effect of the surfactant, being the micellar structure responsible for the hemolytic effect in both cases. Moreover, besides the hemolytic effect, a dual behavior was observed for the surfactant studied: Bz-Arg-NHC12 was also able to protect red blood cells against hypotonic lysis for HRBC in a wide range of surfactant concentrations. However, the degree of protection showed for SRBC was about 50% lower than for HBRC. In this regard, a remarkable volume expansion was evidenced only for SRBC treated with Bz-Arg-NHC12, although no correlation with the antihemolytic potency (pAH) was found. On the contrary, our surfactant showed a greater pAH when human erythrocytes were submitted to hypotonic stress, with a low volume expansion, showing a higher amount of solubilized phospholipids in the supernatant when compared with SRBC behavior. Surface plasmon resonance measurements show the molecular interaction of the surfactant with lipid bilayers from HRBC and SRBC lipids, demonstrating that in the latter neither microvesicle release or lipid extraction occurred. Our results demonstrate that the volume expansion of erythrocytes is not the only mechanism responsible for the protection by surfactants against hypotonic hemolysis: volume expansion could be compensated via microvesicle release or by the extraction of membrane components upon collisions between red blood cells and surfactant aggregates depending on the membrane composition.Centro de Investigación de Proteínas VegetalesInstituto de Investigaciones Bioquímicas de La PlataInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Volume expansion of erythrocytes is not the only mechanism responsible for the protection by arginine-based surfactants against hypotonic hemolysis

A novel arginine-based cationic surfactant Nα-benzoyl-arginine dodecylamide (Bz-Arg-NHC12) was synthesized in our laboratory. In this paper we study the interaction of Bz-Arg-NHC12 with sheep and human red blood cells (SRBC and HRBC respectively) due to their different membrane physicochemical/biophysical properties. SRBC demonstrated to be slightly more resistant than HRBC to the hemolytic effect of the surfactant, being the micellar structure responsible for the hemolytic effect in both cases. Moreover, besides the hemolytic effect, a dual behavior was observed for the surfactant studied: Bz-Arg-NHC12 was also able to protect red blood cells against hypotonic lysis for HRBC in a wide range of surfactant concentrations. However, the degree of protection showed for SRBC was about 50% lower than for HBRC. In this regard, a remarkable volume expansion was evidenced only for SRBC treated with Bz-Arg-NHC12, although no correlation with the antihemolytic potency (pAH) was found. On the contrary, our surfactant showed a greater pAH when human erythrocytes were submitted to hypotonic stress, with a low volume expansion, showing a higher amount of solubilized phospholipids in the supernatant when compared with SRBC behavior. Surface plasmon resonance measurements show the molecular interaction of the surfactant with lipid bilayers from HRBC and SRBC lipids, demonstrating that in the latter neither microvesicle release or lipid extraction occurred. Our results demonstrate that the volume expansion of erythrocytes is not the only mechanism responsible for the protection by surfactants against hypotonic hemolysis: volume expansion could be compensated via microvesicle release or by the extraction of membrane components upon collisions between red blood cells and surfactant aggregates depending on the membrane composition.Centro de Investigación de Proteínas VegetalesInstituto de Investigaciones Bioquímicas de La PlataInstituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Insights into speleothems from lava tubes of the Galapagos Islands (Ecuador): mineralogy and biogenecity

Different types of hard and soft speleothems (stalactites, stalagmites, columns, crusts, flowstones, micro-gours and botryoidal coralloids) have been observed throughout lava tubes in the Galapagos archipelago, Ecuador. Three lava tubes were studied in this work: Gallardo and Royal Palm volcanic caves (Santa Cruz Island) and Sucre Cave (Isabela Island). The studied speleothems were mainly formed by opal, calcite and clay minerals, including plagioclase and pyroxenes from the basaltic host rock. Rarely, iron oxides, gypsum were found in some speleothems, which were interpreted as alteration products of the primary volcanic materials. Field emission scanning electron microscopy revealed abundant filamentous 17th International Vulcanspeleology Symposium 2 bacteria, and reticulated filaments similar to those recently observed in others lava tubes around the world. These filaments are associated with EPS and mineral deposits rich in Si, Ca or Fe. The identified minerals and the evidence of biosignatures suggest a biological contribution to speleothem development within Gallardo, Royal Palm and Sucre lava tubes

Women and employment: advances and challenges in policies for women's labour-force participation in Europe, Latin America and the Caribbean in the context of the post-pandemic recovery

The purpose of this document is to provide inputs and contribute to reflection for decision-making in the field of equality in employment between men and women. It aims to be a document of proposals and measures of public policies that can be taken into consideration, both in the 27 countries of the European Union (EU27) and in their relationship with their partners in Latin America and the Caribbean (LAC), to increase women's participation into labour market in a stable and equitable manner.Fil: Daza Aramayo, LourdesFil: Křížková, AlenaFil: López Igual, PurificaciónFil: Černohorská, Vanda MaufraFil: Nyklová, BlankaFil: Partida Rocha, RaquelFil: Peterson, ElinFil: Pospíšilová, MarieFil: Rocha Carpiuc, CeciliaFil: Rodríguez-Modroño, PaulaFil: Távora, IsabelFil: Vohlidalová, MartaFil: Actis Di Pasquale, Eugenio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Addabbo, TindaraFil: Aspiazu, Eliana. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Cutuli, Romina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Damiani, FilippoFil: Daza Aramayo, Lourdes GabrielaFil: Dudová, RadkaFil: Espinosa Fajardo, JuliaFil: Fernández Marín, Ana MaríaFil: Formánková, LenkaFil: Hermanová, Mari

Distribution, composition and genesis of the silica deposits in the Branca Opala volcanic cave (Terceira, Azores Islands)

La cueva de Branca Opala es un tubo volcánico localizado en la zona basáltica fisural de la isla de Terceira (Islas Azores, Portugal). Se identifican dentro de la cueva tres tipos de depósitos: estromatolitos, depósitos terrígenos siliciclásticos provenientes de la roca volcánica y depósitos formados por restos vegetales con sedimentos terrígenos. En el exterior, y en zonas próximas, se estudian también tobas silíceas. En los estromatolitos se definen tres partes desde el substrato de crecimiento: laminar inferior, arborescente-esferoidal y laminar superior, encontrándose en todas ellas estructuras filamentosas interpretadas como bacterias. La única fase silícea que forma los estromatolitos es un ópalo A inmaduro, por lo que se deduce que son relativamente recientes. Los basaltos de la cueva, y los sedimentos volcanoclásticos finos no presentan casi alteración, por lo que aguas freáticas y de escorrentía aportarían la sílice a la cueva, siendo fijada por bacterias, y formándose estromatolitos en condiciones subacuáticasThe Branca Opala cave is a lava-tube located in the basaltic fissurale zone of the island of Terceira (Azores archipelago, Portugal). Three types of deposits are identified inside the cave: stromatolites, terrigenous siliciclastic deposits from the volcanic rock and deposits formed by vegetal remains and terrigenous sediments. In the outer parts of the cave a siliceous tuff is also studied. From the growth substrate three parts are defined in the stromatolites: lower laminar, dendriform-spheroidal and superior laminar. In all of them, filamentous structures are found, and are interpreted as bacteria. The only silica phase forming stromatolites is an inmature, thus relatively recent, opal A. The silica source is not found either in the basaltic host rocks or in the fine volcanoclastic deposits because they are little altered. Groundwaters and runoff would contribute the silica to the cave, where the bacteria would fix the silica, forming stromatolites under subaquatic environment

Mujeres y empleo: avances y desafíos en las políticas para la participación laboral de las mujeres en Europa, América Latina y Caribe en el contexto de la recuperación post-pandémica

El presente documento tiene como finalidad aportar insumos y contribuir a la reflexión para la toma de decisiones en el ámbito de la igualdad en el empleo entre hombres y mujeres. Pretende ser un documento de propuestas y medidas de políticas públicas que podrán tomarse en consideración, tanto en los 27 países de la Unión Europea (UE27) como en su relación con sus socios de América Latina y el Caribe (ALC), para contribuir a una mayor incorporación de mujeres al empleo de manera estable y en condiciones de equidad. Para ello, el documento se ha ordenado en cuatro secciones estructuradas tal y como se expone a continuación.Fil: Daza Aramayo, LourdesFil: Křížková, AlenaFil: López Igual, PurificaciónFil: Černohorská, Vanda MaufraFil: Nyklová, BlankaFil: Partida Rocha, RaquelFil: Peterson, ElinFil: Pospíšilová, MarieFil: Rocha Carpiuc, CeciliaFil: Rodríguez-Modroño, PaulaFil: Távora, IsabelFil: Vohlidalová, MartaFil: Actis Di Pasquale, Eugenio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Addabbo, TindaraFil: Aspiazu, Eliana. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Cutuli, Romina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina.Fil: Damiani, FilippoFil: Daza Aramayo, Lourdes GabrielaFil: Dudová, RadkaFil: Espinosa Fajardo, JuliaFil: Fernández Marín, Ana MaríaFil: Formánková, LenkaFil: Hermanová, Mari

The Caldera. No. 14

El Instituto Caldas decidió implementar este año el Sistema de Gestión de la Calidad, asumiendo como principal objetivo mejorar permanentemente el servicio educativo que ofrecemos y cumplir con las expectativas de padres de familia y estudiantes. Para llevar a cabo este propósito, contamos con el apoyo incondicional de la UNAB y de toda la comunidad educativa, quienes de manera activa participaron en cada una de las actividades programadas para el logro de este objetivo. Este proceso nos permitió conocer nuestras fortalezas y áreas de oportunidad, basados en evidencias; información a partir de la cual se inicia el mejoramiento institucional.Entrevista a: Claudia Lucía Salazar Jaimes; Por Consuelo Parra Rodríguez…04 Tendencias educativas: Pedagogía por proyectos; Por Gisela Afanador Díaz…10 Celta: University of Cambridge; Por Oscar Mauricio Ortíz Delgado…16 Project Free Time; Por Freddy Augusto López…18 Reloj Solar: Un merecido reconocimiento a tan significativa labor…19 Una visita muy esperada; Por Grace Jurado Daza…20 Biblioteca Escolar Caldas: Con un antes y un después todos podemos hacer la diferencia; Por Freddy Quitián Fino…22 XIII Simposio Estudiantil: Liderazgo y contexto social; Por Natalia Franco y Leidy Villamizar (Estudiantes de 11B) …23 Concurso Intercolegiado de Ortografía; Por Natalia Franco y Leidy Villamizar (Estudiantes de 11B) …24 Asofacaldas…25 Soy autónomo, soy caldista TV; Por Abelardo Carreño Gómez…28 Galería…30The Caldas Institute decided to implement the Quality Management System this year, assuming the main objective of permanently improving the educational service we offer and meeting the expectations of parents and students. To carry out this purpose, we have the unconditional support of UNAB and the entire educational community, who actively participated in each of the activities programmed to achieve this objective. This process will get us to know our strengths and areas of opportunity, based on evidence; information from which institutional improvement begins

Mineralogía de los bioespeleotemas de la >Galeria da Queimada> (Terceira, Azores)

El trabajo fue subvencionado con el proyecto CGL-2011-27826-CO2-02 (MICINN).Peer Reviewe