Cell aggregation: a mechanism of pathogenic Leptospira to survive in fresh water

Transmission of leptospirosis is facilitated by the survival of pathogenic leptospires in moist environments outside their mammalian host. In the present study, the survival mechanisms of Leptospira interrogans serovar Canicola in aqueous conditions and lack of nutrients were investigated. In distilled water, leptospires were able to remain motile for 110 days (pH 7.2). However, when incubated in a semi-solid medium composed of distilled water and 0.5% purified agarose (pH 7.2), they survived 347 days. In this viscous environment, aggregates of live spirochetes were observed. Neither antibiotics (e.g. tetracycline and ampicillin) nor nutrients inhibited leptospiral aggregation. Immunoblot analysis suggested that cells incubated in water down-regulate the expression of LipL31, an inner-membrane protein, but retain expression of other membrane proteins. These studies provide insights into the mechanisms by which pathogenic Leptospira survives for prolonged periods of time in natural aqueous environments, a key stage in the leptospiral lifecycle. [Int Microbiol 2004; 7(1):35–39

Point source generation of chiral fields:measures of near- and far-field optical helicity

To consider the relationship between different measures of chirality in an optical field, the simplest case is considered: direct spontaneous emission of circularly polarized light by a point source. In the electromagnetic fields radiated from a suitably chiral source, such as a low-symmetry chiral molecule undergoing radiative decay, optical helicity is exhibited in the extent of a difference in left- and right-handed circular polarization components. There are several practical measures for quantifying the emergence of ensuing optical helicity, exhibiting different forms of dependence on the properties of the emitter and the positioning of a detector. By casting each measure in terms of an irreducible helicity density, connections and distinctions can be drawn between results expressible in either classical or quantum form

Analysis of the supply chain in commercial ports by SCOR model

Ports as a place where different areas of circulation of merchandise and services converge have be-come spaces of convergence between transport systems, service providers and are integrated into amerchandise distribution system that requires logistical developments. In the current situation, wherethe environment is increasingly complex, organizations must improve their internal and external per-formance, achieving integration with both suppliers and customers. To carry out this process, it isnecessary to identify and analyse the supply chain of each organization because it integrates supply anddemand both inside and outside the company. This integration ties together the functions and processesof the business to make it a coherent, operationally excellent, and high-performance business model.In this sense, the SCOR model (Supply Chain Operations Reference) represents a standard tool for di-agnosing supply chain management, providing a unique framework that integrates business concepts,management indicators, benchmarking, and the identification of best practices, in a structure to supportcommunication between all actors in the supply chain and improve management efficiency. The workanalysed the processes and activities of the supply chain of commercial ports to detect opportunities forimprovement. The description of supply chains following the structure of the SCOR model, allowed toanalyse very simple or complex supply chains using a common set of definitions. As a result, differentactivities could be linked to describe the depth and breadth of almost any supply chain. Continuousprocess improvement is a strategy that allows organizations to continuously generate value, adapting tochanges in the market and permanently satisfying the increasingly demanding needs and expectationsof their customers and users

Fuel production by hydrocracking of non-olefinic plastics and vacuum gasoil blends

306 p.The catalytic hydrocracking of different blends of non-olefinic polymers (polystyrene, polymethylmethacrylate and polyethylene terephthalate) with vacuum gasoil has been studied to produce fuel streams suitable for inclusion in refinery pools. For this purpose, a catalyst synthesized in the laboratory composed of Pt and Pd supported on a zeolite Y has been used. For all the mixtures, the influence of the operating conditions (time, temperature, pressure) and the effect they have on the yields of the fractions of interest (naphtha and light cycle oil), as well as on their composition, have been tested. In addition, special attention has been paid to the physicochemical phenomena that take place during the reactions in order to analyze the catalyst behaviour and the different causes of its deactivation with a view to its implementation in industrial units. The use of advanced analytical techniques has allowed to establish the compositional framework of all samples regardless of their heavy nature, which has allowed to determine the mechanisms of hydrocracking of plastics, as well as the routes of elimination of different families of compounds. Finally, kinetic modelling of these systems has been carried out for the optimization of the operating conditions by performing simulations aiming at the maximum conversion of the plastics and maximum yield of the target fractions, while minimizing the products of less interest

Bioactive ceramic coating solution for offshore floating wind farms

Biofouling is a natural phenomenon that consists of the accumulation of living organisms on an artificial surface submerged or in contact with water like Offshore platforms. This study highlights the need for offshore floating wind farms structures to consider the choice of material used in offshore applications to minimize microbial-associated and corrosion problems. For this purpose, differences in the total of seawater biofouling attached on two coated paints and three ceramic coatings in carbon steel for offshore structures were evaluated and compared. All ceramic coatings were made of incorporating, by electrophoretic deposition, active ceramic particles against biofouling as copper, silver, zinc and titanium. This experiment consisted of testing ceramic coatings and conventional paints in a real environment with high biological activity and at the same time in a shallow marine environment for a period of 1 year, which provided positive comparisons with the standard system (ASTM-D3623) for using in protecting offshore marine structures

Antifouling and anticorrosive protection of renewable energy marine structures with TiO2-based enamel

Biofouling is a significant problem that affects renewable energy marine structures (REMS), such as wind turbines and those designed for wave or tidal energy exploitation. Marine organisms, including algae, barnacles, and mollusks, attach themselves to the surface of these structures, which can lead to reduced efficiency and increased maintenance costs. In addition, biofouling can also cause corrosion, which can compromise the structural integrity of the offshore platforms. To combat this problem, several methods have been developed, including anti-fouling coatings, physical methods, and biological methods. Each method has its advantages and disadvantages, and the most effective solution often depends on the specific type of fouling and the location of the offshore structure. Effective biofouling prevention is essential for the safe and efficient operation of offshore structures and the protection of marine ecosystems. To prevent the spread of invasive species, an innovative ceramic coating has been designed and tested in accordance with ASTM-D3623 procedure. The investigation results revealed that, after four years of experimentation in a real environment, the biofouling growth observed in the splash zone of the antifouling paint was 129.76% higher than that of the titanium-based ceramic coating and it is expected that this difference will continue to grow over time

On the energy consumption of Network Coding techniques

RESUMEN: En la actualidad, las redes de comunicaciones inalámbricas están en continuo crecimiento y, con la llegada de 5G, el número de dispositivos en estas redes va a aumentar considerablemente. Por ello, uno de los protocolos de transporte más utilizados hasta ahora, TCP, no parece una opción adecuada, ya que presenta problemas en redes propensas a errores. Las técnicas de Network Coding se han propuesto como una alternativa viable para este tipo de redes, y se ha demostrado que se pueden alcanzar velocidades aceptables. Sin embargo, no está´ claro el consumo energético adicional que estas técnicas introducen en una comunicación inalámbrica con respecto a otros protocolos. En este trabajo se estudia la energía adicional requerida por un dispositivo transmisor y otro receptor utilizando técnicas de Network Coding, combinadas con el protocolo UDP. Al final de este trabajo se recogen varios resultados relevantes, como el hecho de que se produzca un mayor consumo en el dispositivo receptor que en el transmisor, presentando tendencias de crecimiento diferentes, o variaciones considerables de dicho consumo con el uso de distintas características de codificación.ABSTRACT: Nowadays, wireless networks are growing continuously, and the number of devices is expected to multiply, with the upcoming 5G technology. Thus, one of the most used transport protocols, TCP, seems not to be the best alternative to use over these error prone networks, where it has shown a bad behaviour. Network Coding techniques have been proposed as a possible alternative over these scenarios, and it has already been proved that it can work correctly. However, there are very few studies about the increase of the energy consumption these techniques would introduce. In this document, the additional energy consumption using Network Coding techniques, combined with UDP is studied. It shows that receiving devices consume more energy than transmitting devices, as well as a different growth trend in both scenarios. Finally, the energy consumption using different configurations of these techniques is also analyzed.Grado en Ingeniería de Tecnologías de Telecomunicació

Fog/Cloud Architecture for IIoT scenarios: modeling, deployment, and analysis

RESUMEN: El principal objetivo de este trabajo es el desarrollo de una plataforma de pruebas para arquitecturas Fog/Cloud sobre la que desplegar diferentes servicios en el ámbito del IIoT. Se utilizarán técnicas de virtualización para desplegar diferentes nodos, que se conectarán a través de enlaces virtuales, cuyo comportamiento se modificará gracias a la utilización del entorno Mahimahi, que permite modular sus parámetros de comportamiento, para emular las características de las conexiones sobre redes reales. Posteriormente se modelará la llegada de servicios a los nodos Fog (más cercanos a los dispositivos) y se estudiarán diferentes estrategias para repartir su procesado entre los dos niveles de la arquitectura. Se estudiará el comportamiento de diferentes alternativas, analizando el coste correspondiente, así como el retardo total, teniendo en cuenta diferentes características para los nodos considerados: capacidad de procesado, coste, etc.ABSTRACT: The main purpose of this project is the development of an evaluation platform for Fog/Cloud architectures, where different services in the IIoT field can be deployed. Virtualization techniques will be used to deploy different nodes, which will be connected through virtual links. The behavior of these links will be modified using the Mahimahi environment, which allows to modulate their characteristics, to emulate the behavior of real network connections. Subsequently, the arrival of services to the Fog nodes (closest to the devices) will be modeled, and different strategies will be studied to distribute their processing between the two levels of the architecture. The behavior of different alternatives will be studied, analyzing the corresponding cost, as well as the total delay, taking into account different characteristics for the considered nodes: processing capacity, cost, etc.Máster en Ingeniería de Telecomunicació

Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests

High animal and plant richness in tropical rainforest communities has long intrigued naturalists. It is unknown if similar hyperdiversity patterns are reflected at the microbial scale with unicellular eukaryotes (protists). Here we show, using environmental metabarcoding of soil samples and a phylogeny-aware cleaning step, that protist communities in Neotropical rainforests are hyperdiverse and dominated by the parasitic Apicomplexa, which infect arthropods and other animals. These host-specific parasites potentially contribute to the high animal diversity in the forests by reducing population growth in a density-dependent manner. By contrast, too few operational taxonomic units (OTUs) of Oomycota were found to broadly drive high tropical tree diversity in a host-specific manner under the Janzen-Connell model. Extremely high OTU diversity and high heterogeneity between samples within the same forests suggest that protists, not arthropods, are the most diverse eukaryotes in tropical rainforests. Our data show that protists play a large role in tropical terrestrial ecosystems long viewed as being dominated by macroorganisms

Comparison between 3 types of alternative connections for a steel building under seismic load

Se presenta un método de evaluación de 3 tipos de conexiones de acero de un edificio ante carga sísmica, para generar recomendaciones en cuanto a la selección de conexionesSe presenta una metodología analítica basada en simulaciones de Monte Carlo y resultados experimentales previos, la cual permite comparar la efectividad en costo de 3 tipos de conexiones alternativas de acero, considerando las incertidumbres en carga sísmica y resistencias. Dicha efectividad se mide a través de la probabilidad de falla y el costo esperado en el ciclo de vida del edificio. Dado que, para el cálculo de la probabilidad de falla, el proceso crudo de simulación se vuelve muy largo y pesado, en la presente metodología se propone un procedimiento basado en 2 etapas: 1) análisis no lineal de la máxima respuesta de la junta crítica ante escenarios predefinidos de aceleraciones sísmicas típicas en la Ciudad de México e identificación de la relación funcional entre la respuesta máxima y dichas aceleraciones sísmicas y; 2) identificación, mediante análisis de elemento finito, del estado límite crítico de cada conexión en función de la respuesta máxima y simulación de Monte Carlo mediante ensayos del estado límite de cada conexión variando aleatoriamente la respuesta máxima obtenida en 1). Con la probabilidad de falla se calcula el costo esperado en el ciclo de vida del edificio, que incluye las principales consecuencias de falla del mismo: costo asociado a fatalidades, pérdida del edificio y contenidos y pérdida económica derivada de la interrupción de los servicios en el edificio. Con las probabilidades de falla y costos esperados en el ciclo de vida del edificio con las 3 alternativas de conexión, se generan recomendaciones para su uso en el ambiente sísmico de la Ciudad de México. Los diseñadores podrán adaptar la metodología para las condiciones de tipo estructural, demanda sísmica y costos que correspondan a sus casos