Antifouling activity of peracetylated cholic acid, a natural bile acid derivative

The antifouling activity of peracetylated cholic acid (1), a bile acid derivative which was isolated in a previous work as a natural product from the Patagonian sponge Siphonochalina fortis, was evaluated in laboratory and field trials. Toxicity and settlement assays were performed with the mussel Mytilus edulis platensis, while the field trials were carried out by addition of the compound to experimental soluble-matrix paints, which were then tested in the sea. The results obtained in this work show that 1 has a good antifouling activity and low toxicity, and the paints aditivated with 0,6% Wt showed promissory performances in the field trials at the sea. These results confirm the previous hypothesis that the few acetylated and lipophilic bile acid derivatives isolated from marine invertebrates may act as natural antifoulants. Compound 1 is a natural, biodegradable product that can be easily prepared from cholic acid, which in turn can be isolated in industrial scale from cattle bile. All these facts make cholic acid a good scaffold for the preparation of derivatives, which can be natural product-like, effective and sustainable antifouling additives for marine paints and other applications.Fil: Pérez, Miriam. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Sánchez, Marianela. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: García, Mónica. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Patiño Cano, Laura Patricia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Blustein, Guillermo. Universidad de Buenos Aires; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Palermo, Jorge Alejandro. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentin

Effect of doors opening in refrigerated cabinets: phenomenological study of the thermodynamic behavior and air flow dynamics

During last years, supermarkets have increased the demand for closed refrigerated display cabinets due to new regulations and trends on energy and sustainability. However, the performance of this type of refrigerated display cabinets is not completely known, being of utmost importance how the airflow distributions could affect over the temperature distributions inside the cabinet. Consequently, this work presents a numerical evaluation of the performance of closed display cabinets focusing on the effect of the sliding doors opening process. The set of computational fluid dynamics (CFD) simulations served to validate the use of immersed solid approach in order to accurately analyze and evaluate transient behavior of the turbulent air flow distributions and temperature evolutions inside the cabinet and over the products, and characterizing the air curtain disruptions and the warm air entrainment during the opening process of the cabinet sliding doors (i.e. from closed doors, through doors opening process and to doors totally open)

On-line quizzes to evaluate comprehension and integration skills

This work demonstrates the use of a 2.0 tool, namely, Socrative, to evaluate one of the cross-curricular competences indicated by the Universitat Politècnica de València, specifically, comprehension and integration. It has been applied to the courses in different areas: sciences, engineering and languages. As part of its implementation, activities were proposed that could be done at the beginning, during or at the end of the class to, on the one hand, help students acquire the knowledge associated with the course(s), and on the other, gather evidence that demonstrates acquisition of said competence. The results show a high level of satisfaction by the students with the use of the Socrative tool as an element to promote active participation and the acquisition of the cross-curricular competence of comprehension and integration; therefore, its extension to other courses has been suggested

Laboratory analysis of soil respiration using oxygen-sensitive microplates

Soil respiration is usually monitored by measuring CO2 efflux. Most techniques available for such kind of analyses are inconvenient and difficult to adapt to micro-method format. The present study evaluates a new microplate-based method for studying soil respiration in the laboratory. Second-generation oxygen-sensitive microplates (OSM - containing a fluorescent probe attached to the bottom of the well which provides time-resolved fluorescence data) were used to measure soil respiration either in microcosm assays or in soil water extracts. The latter procedure (water extracts) was the least cumbersome, hence it was selected for further experiments. Soil respiration curves generally showed no lag phase, starting with an exponential oxygen consumption phase, followed by a period where respiration became stable after 8-10 h of incubation at 25 ºC. Once the procedure for measurement of oxygen consumption in soil was established, the acute toxic effect of diverse chemicals on soil was analysed with OSM. Streptomycin and penicillin failed to reduce soil respiration. Kanamycin plus neomycin, trimethoprim and 5-fluorocytosine exhibited limited inhibitory effects. In contrast, some chemicals (copper sulphate and amphotericin B) and fungicides (such as dodine and fosetyl) noticeably reduced fluorescence readings, showing concentrations to give half-maximal inhibition of respiration (ICR50) ranging from 0.0064 to 0.082 g/L. Finally, some insecticides and soil amendments assayed were either neutral or increased respiration. It is concluded that OSM are reliable, convenient, and yield quantitative results. Moreover, the system is relatively inexpensive and amenable to automation. However, results obtained using soil water extracts may be different from those derived from undisturbed soil aggregates, clods or slurries studied under field conditions

Ultrastructural Study of Acanthamoeba polyphaga Trophozoites and Cysts Treated In Vitro with Cationic Carbosilane Dendrimers

Cationic carbosilane dendrimers are branched molecules with antimicrobial properties. Their activity has been tested againstAcanthamoeba polyphaga, a causative agent ofAcanthamoebakeratitis, a severe ocular disease in humans.A. polyphagatrophozoites and cysts were exposed to different noncytotoxic cationic carbosilane dendrimers with proven antiamoebic activity. The effects of treatment on cell surface and cell ultrastructure were examined by scanning and transmission electron microscopy, respectively. Two of the dendrimers tested induced dramatic alterations of cellular ultrastructure in both trophozoites and cysts, including vacuolization, depletion of cytoplasmic contents, and reduced cell size. Additionally, we observed severe alterations of the plasma membrane with membrane blebbing in trophozoites and disruption in cysts. These alterations were also observed with chlorhexidine, a drug used for treatment ofAcanthamoebakeratitis. Our results support that these compounds may target membranes, and their action is critical for parasite integrity.Ministerio de Economía y CompetitividadComunidad de MadridJunta de Comunidades de Castilla-La Manch

El Plan de Ordenamiento Territorial de Medellín 2014: un modelo territorial para la intervención estratégica

Este artículo presenta una reflexión acerca de la tradición del planeamiento en Medellín, producto del proceso llevado a cabo por miembros del equipo que ha liderado la revisión reciente del Plan de Ordenamiento Territorial desde el Departamento Administrativo de Planeación de la Alcaldía de Medellín entre 2012 y 2015. Esta reflexión ha sido un insumo para contextualizar el nuevo plan en la práctica urbanística de Medellín. Se identifican tres momentos relevantes que han sido decisivos para sentar las bases de la cultura del plan en la ciudad. Igualmente se presentan los resultados obtenidos de la revisión mencionada y en los planteamientos y productos que componen el nuevo Plan de Ordenamiento Territorial de Medellín, que orientará el destino urbanístico de la ciudad durante los próximos veinte años. Palabras clave: Medellín, Ordenación del territorio, Plan de Ordenamiento Territorial, Modelo de Ocupación Territorial, Áreas de Intervención Estratégica, Planeamiento MultiescalarThis article presents a review about the tradition of planning in Medellin. It’s derived from the process carried out by members of the team that led the Territorial Ordering Plan review from the Planning Department of the Municipality of Medellin between 2012 and 2015. This discussion has been an input to contextualize the new plan in the urban practice of Medellin. The text focuses on the identification of three important moments from which laid the foundations of the culture of planning in the city. Describes the results of the recent review, approaches and products that make up the new Territorial Ordering Plan, which will guide the city for the next twenty years

Diseño y desarrollo de un mueble frigorífico comercial con funcionamiento autónomo durante ciertos periodos de tiempo

El trabajo presentado en este artículo se basa en integrar en el interior de un mueble frigorífico comercial un fluido caloportador con cambio de fase que permite un funcionamiento totalmente autónomo durante un periodo de tiempo, sin necesidad de conexión eléctrica para mantener la temperatura del alimento perecedero. En este artículo se presenta una nueva solución para optimizar el rendimiento de los muebles frigoríficos destinados al almacenamiento de producto perecedero en un supermercado a la vez que se abre una nueva posibilidad de añadir servicios nuevos que hasta la fecha el mercado desconoce. Este estudio se ha llevado a cabo a partir de la acumulación térmica de un fluido compuesto por muestras PCM (Phase Change Material) y de la optimización de todos los mecanismos de transmisión de calor que coexisten durante el funcionamiento de un mueble. El almacenamiento de calor en un momento determinado para disponerlo más tarde se presenta como una solución sin precedentes. En este sentido, nace una manera nueva de producir frío que nos va a permitir recargar este acumulador térmico en horario de tarificación eléctrica más bajo y proporcionar un servicio autónomo y continuado para mantener las condiciones que necesita el almacenamiento del producto perecedero durante el horario de mejor coste energético y mitigando las variaciones de temperatura que pueda sufrir el producto perecedero

Antifouling activity of peracetylated cholic acid, a natural bile acid derivative

The antifouling activity of peracetylated cholic acid (1), a bile acid derivative which was isolated in a previous work as a natural product from the Patagonian sponge Siphonochalina fortis, was evaluated in laboratory and field trials. Toxicity and settlement assays were performed with the mussel Mytilus edulis platensis, while the field trials were carried out by addition of the compound to experimental soluble-matrix paints, which were then tested in the sea. The results obtained in this work show that 1 has a good antifouling activity and low toxicity, and the paints aditivated with 0,6% Wt showed promissory performances in the field trials at the sea. These results confirm the previous hypothesis that the few acetylated and lipophilic bile acid derivatives isolated from marine invertebrates may act as natural antifoulants. Compound 1 is a natural, biodegradable product that can be easily prepared from cholic acid, which in turn can be isolated in industrial scale from cattle bile. All these facts make cholic acid a good scaffold for the preparation of derivatives, which can be natural product-like, effective and sustainable antifouling additives for marine paints and other applications.Centro de Investigación y Desarrollo en Tecnología de Pintura

Unificando y administrando los servicios de red con zentyal

Con el surgimiento de problemáticas en lo que tiene que ver con la migración de un sistema operativo a otro, como sus servicios y seguridad en la red, se aborda la solución e implementación de aquellos servicios que se necesitan. Se desarrollan soluciones a los problemas presentados, ampliando un pensamiento desde punto de vista del ingeniero, supliendo las necesidades presentadas a nivel empresarial.With the emergence of problems in what has to do with the migration from one operating system to another, such as its services and network security, the solution and implementation of those services that are needed are addressed. Solutions are developed to the problems presented, expanding a thought from the point of view of the engineer, supplying the needs presented at the business level

Aceptabilidad del ensilaje de la parte aérea de la yuca adicionado con diferentes tipos y cantidades de aditivos en bovinos

The objective of this research was to evaluate the influence of the addition of different types and proportions of byproducts and silage additives to the aerial part of cassava on their acceptability silage at different times, involving the sensory variables, chemical composition and acceptability silage. Experimental design was completely randomized with seven types or proportions of additives and four times silage. Treatments were as a witness, the aerial part of cassava supplemented with 2% molasses, common addition in all treatments; Sil-All® (bacterial inoculant); rice bran (15 and 30% inclusive); ground corn cobs (15 and 30% inclusion) and sugar (3% inclusion). The silages added with tusa were largely accepted by the animals, reflected this in greater number and timing of visits and increased consumption. The silages that included bran were the least accepted. The opening of the silo age did not affect (P>0.05) the study variables. The preference of the animals for the ensiled material compared to silage material not confirmed. The acceptability of the ensiled material was related to some quality variables such as pH, ADF, hemicellulose, fat and DISMS.  l objetivo de esta investigación fue evaluar la influencia de la adición de diferentes tipos y proporciones de subproductos y aditivos al ensilaje de la parte aérea de la yuca sobre su aceptabilidad a diferentes tiempos de ensilado, asociando las variables organolépticas, de composición química y aceptabilidad del ensilaje. Se utilizó un diseño completamente al azar con siete tipos o proporciones de aditivos y cuatro tiempos de ensilado. Los tratamientos fueron: como testigo, la parte aérea de la yuca adicionada con 2% de melaza, adición común en todos los tratamientos; Sil-All® (inoculante bacteriano); salvado de arroz (15 y 30% de inclusión); tusa de maíz molida (15 y 30% de inclusión) y azúcar (3% de inclusión). Los ensilajes adicionados con tusa fueron mayormente aceptados por los animales, reflejado esto en mayor número y tiempo de visitas y un mayor consumo. Los ensilajes que incluyeron salvado fueron los menos aceptados. La edad de abertura del silo no afectó (P>0.05) las variables en estudio. Se confirmó la preferencia de los animales por el material ensilado en comparación al material no ensilado. La aceptabilidad de los materiales ensilados se relacionó con algunas variables de calidad, como pH, FDA, hemicelulosa, grasa y la DISMS