256 research outputs found

    Application of the Eco-Epidemiological Method in the Study of Leishmaniasis Transmission Foci

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    The study of transmission foci involves the clinical characterization of disease within a focus using active surveillance of human cases, characterization of the population group that is most frequently infected or at highest risk of becoming infected, diagnosis and treatment of infected people and identification of the conceptions, attitudes, beliefs and practices related to the disease. An entomological survey is necessary to determine the geographical distribution of species and incrimination of vector species, the ecological characteristics of the zone (macro-focus), times of the year and day of highest biting activity and places in homes in which the most frequent contact between the people and the vectors occurs. A survey of peri-domestic and wild mammals in the area is advisable to try to identify potential reservoir hosts. Using this information, it is feasible to design specific and accurate prevention and effective, rational and economic control measures and define the times of the year and locations in which these measures must be applied. In this chapter, a description of the application of the eco-epidemiological method to the study of leishmaniasis transmission foci is provided. A special emphasis is placed on the methodology, multidisciplinary work and analysis of findings

    Tuning interfacial domain walls in GdCo/Gd/GdCo′ spring magnets

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    Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al.Spring magnets based on GdCo multilayers have been prepared to study the nucleation and evolution of interfacial domain walls (iDWs) depending on layer composition and interlayer coupling. GdCo alloy compositions in each layer were chosen so that their net magnetization aligns either with the Gd (Gd35Co65) or Co(Gd11Co89) sublattices. This condition forces an antiparallel arrangement of the layers' net magnetization and leads to nucleation of iDWs above critical magnetic fields whose values are dictated by the interplay between Zeeman and exchange energies. By combining x-ray resonant magnetic scattering with Kerr magnetometry, we provide detailed insight into the nucleation and spatial profile of the iDWs. For strong coupling (GdCo/GdCo′ bilayer), iDWs are centered at the interface but with asymmetric width depending on each layer magnetization. When interlayer coupling is weakened by introducing a thin Gd interlayer, the exchange spring effect becomes restricted to a lower temperature and field range than observed in the bilayer structure. Due to the ferromagnetic alignment between the high magnetization Gd35Co65 layer and the Gd interlayer, the iDW shrinks and moves into the lower exchange Gd interlayer, causing a reduction of iDW energy.Work supported by Spanish Ministerio de Economía y Competitividad (MINECO) under grant FIS2013-45469 and Spanish Ministerio de Ciencia e Innovacion (MICINN) under grant FIS2008-06249. Work at Argonne was supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.Peer Reviewe

    Control de los movimientos de un brazo robótico desde un computador utilizando software libre de control y comunicación inalámbrica con módulos X-BEE

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    This document demonstrates the control of a robotic arm wirelessly by using free software. For this, an operator (user) will be the one giving the orders and actions to be taken, using a computer through various input devices and XBEE modules that are part of our communication channel. The fact that the system includes wireless communication allows distancing the operator from the robot arm and thus can reduce risk when working in addition a large number of wires that may hinder or impede the development of any activity is eliminated. The system has several options for handling the mechanical arm which has developed a free software interface that would maximize all basic input devices of the computer. The software in question is the Processing program which allows the arm to be controlled by keyboard, mouse or even using motion detection through a webcam, and to employ USB output port to transmit data through the modules XBEE.Finally have to say that the results obtained in a complete system prototype robotic arm can serve as a basis for developing several applications including, for example, remote rovers.El presente trabajo muestra el control de un brazo robótico de forma inalámbrica usando software libre. Para esto un operador (usuario) será quien dé las órdenes y acciones a realizar, haciendo uso de un ordenador a través de los diferentes dispositivos de entrada y los módulos XBEE que forman parte de nuestro canal de comunicación. El hecho que el sistema incluya comunicación inalámbrica permite distanciar al operador del brazo robótico y de esta manera se pueda reducir el riesgo al momento de trabajar, además que se elimina una gran cantidad de cables que pueden obstaculizar o dificultar el desarrollo de cualquier actividad. El sistema tiene varias opciones de manipulación del brazo mecánico para lo cual se ha desarrollado una interfaz en software libre que permita aprovechar al máximo todos los dispositivos de entrada básicos del computador. El software en mención es el programa Processing que permite que el brazo sea controlado por el teclado, el mouse o incluso usando detección de movimiento a través de una cámara web, y emplear un puerto USB como salida para la transmisión de datos a través de los módulos XBEE.Finalmente queda decir que los resultados del sistema completo obtenidos en un brazo robótico de prototipo pueden servir como base para el desarrollo de varias aplicaciones entre ellas, por ejemplo, telecontrol de robots exploradores

    Diseño y control de filtros activos mediante simulación HIL

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    La implementación de los filtros activos es una de las soluciones más eficientes a la problemática que plantea el creciente uso de cargas no lineales en la red eléctrica y la proliferación de cargas distribuidas provenientes de energías renovables conectadas a la misma. El diseño de un filtro activo y del algoritmo para su control pueden realizarse mediante la simulación “Hardware in the loop” (HIL) en tiempo real. Estas simulaciones sirven de interfaz entre el modelo matemático de todos los elementos dinámicos relacionados con el sistema eléctrico bajo control (simulación de la planta) y el sistema integrado bajo prueba. En este trabajo se ha desarrollado la simulación en la máquina virtual de Typhoon HIL, tanto del modelo del filtro activo como de su algoritmo de control. Tras la comprobación de los modelos se ha implementado el algoritmo en una tarjeta de procesamiento digital (DSP). Para la elaboración del código de programación necesario en este sistema de control de prueba se incorporan las herramientas Simulink de Matlab y Code Composer Studio (CCS). Los resultados han sido satisfactorios en general y ofrecen la posibilidad de la implementación física del sistema propuesto con un coste reducido.Active Power Filter implementation is one of the most efficient solutions for problems which raises non-linear loads in the electric net and proliferation of the distributed charges which are coming from the connection of renewable energy sources. The active filter design and its control algorithm can do with the real time simulation “Hardware in the loop” (HIL). These simulations work as interface between the mathematician model of all dynamic elements, which relate to the under control electric system, and the integrated system which is under test. In this project, the simulation in the virtual machine of Typhoon HIL has been developed, including the filter active model and its control algorithm. After checking the model, the algorithm has been implanted in a digital signal processor card. To write the necessary programming code in this embedded system under test, Simulink of Matlab and Code Composer Studio tools are used. In general, results have been satisfactory, so the designed model give us the chance of implementing physically the system with a reduced price

    The Oesophageal Squamous Cell Carcinoma Cell Line COLO-680N Fails to Support Sustained Cryptosporidium parvum Proliferation

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    Cryptosporidium parvum is an important diarrhoea-associated protozoan, which is difficult to propagate in vitro. In 2017, a report described a continuous culture of C. parvum Moredun strain, in the oesophageal squamous cell carcinoma cell line COLO-680N, as an easy-to-use system for C. parvum propagation and continuous production of oocysts. Here, we report that—using the Köllitsch strain of C. parvum—even though COLO-680N cells, indeed, allowed parasite invasion and early asexual parasite replication, C. parvum proliferation decreased after the second day post infection. Considering recurring studies, reporting on successful production of newly generated Cryptosporidium oocysts in the past, and the subsequent replication failure by other research groups, the current data stand as a reminder of the importance of reproducibility of in vitro systems in cryptosporidiosis research. This is of special importance since it will only be possible to develop promising strategies to fight cryptosporidiosis and its ominous consequences for both human and animal health by a continuous and reliable methodological progress

    First Metabolic Insights into Ex Vivo Cryptosporidium parvum-Infected Bovine Small Intestinal Explants Studied under Physioxic Conditions

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    The apicomplexan Cryptosporidium parvum causes thousands of human deaths yearly. Since bovines represent the most important reservoir of C. parvum, the analysis of infected bovine small intestinal (BSI) explants cultured under physioxia offers a realistic model to study C. parvum–host cell–microbiome interactions. Here, C. parvum-infected BSI explants and primary bovine small intestinal epithelial cells were analysed for parasite development and metabolic reactions. Metabolic conversion rates in supernatants of BSI explants were measured after infection, documenting an immediate parasite-driven metabolic interference. Given that oxygen concentrations affect cellular metabolism, measurements were performed at both 5% O2 (physiological intestinal conditions) and 21% O2 (commonly used, hyperoxic lab conditions). Overall, analyses of C. parvum-infected BSI explants revealed a downregulation of conversion rates of key metabolites—such as glucose, lactate, pyruvate, alanine, and aspartate—at 3 hpi, followed by a rapid increase in the same conversion rates at 6 hpi. Moreover, PCA revealed physioxia as a driving factor of metabolic responses in C. parvum-infected BSI explants. Overall, the ex vivo model described here may allow scientists to address pending questions as to how host cell–microbiome alliances influence intestinal epithelial integrity and support the development of protective intestinal immune reactions against C. parvum infections in a realistic scenario under physioxic conditions

    Ideal cardiovascular health and incident cardiovascular disease among adults: a systematic review and meta-analysis

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    Objective: To investigate the association between ideal cardiovascular health (CVH) metrics and incident cardiovascular disease (CVD) by conducting a systematic review and meta-analysis of prospective cohort studies. Methods: The MEDLINE, EMBASE, and CINAHL databases were searched from January 1, 2010 through July 31, 2017, for studies that met the following criteria: (1) prospective studies conducted in adults, (2) with outcome data on CVD incidence and (3) a measure of ideal CVH metrics. Results: Twelve studies (210,443 adults) were included in this analysis. Compared with adults who met 0 to 2 of the ideal CVH metrics (high-risk individuals), a significantly lower hazard for CVD incidence was observed in those who had 3 to 4 points for the ideal CVH metrics (hazard ratio [HR]=0.53; 95% CI, 0.47-0.59) and 5 to 7 points (HR=0.28; 95% CI, 0.23-0.33). Weaker associations were observed in studies with older individuals, suggesting that there is a positive relationship between age and HR. Conclusion: Although meeting 5 to 7 metrics is associated with the lowest hazard for CVD incidence, meeting 3 to 4 metrics still offers an important protective effect for CVD. Therefore, a realistic goal in the general population in the short term could be to promote at least an intermediate ideal CVH profile (3 to 4 metrics)

    Synthesis, Leishmanicidal and Cytotoxic Activity of Triclosan-Chalcone, Triclosan-Chromone and Triclosan-Coumarin Hybrids

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    Twelve hybrids derived from triclosan were obtained via Williamson etherification of O-triclosan alkyl bromide plus chalcone and O-coumarin or O-chromone alkyl bromide plus triclosan, respectively. Structures of the products were elucidated by spectroscopic analysis. The synthesized compounds were evaluated for antileishmanial activity against L. (V) panamensis amastigotes. Cytotoxic activity was also evaluated against mammalian U-937 cells. Compounds 7–9 and 17, were active against Leishmania parasites (EC50 = 9.4; 10.2; 13.5 and 27.5 µg/mL, respectively) and showed no toxicity toward mammalian cells (>200 µg/mL). They are potential candidates for antileishmanial drug development. Compounds 25–27, were active and cytotoxic. Further studies using other cell types are needed in order to discriminate whether the toxicity shown by these compounds is against tumor or non-tumor cells. The results indicate that compounds containing small alkyl chains show better selectivity indices. Moreover, Michael acceptor moieties may modify both the leishmanicidal activity and cytotoxicity. Further studies are required to evaluate if the in vitro activity against Leishmania panamensis demonstrated here is also observed in vivo.The authors thank COLCIENCIAS (contract No. 0333-2013, code: 111556933423) and the Universidad de Antioquia (Estrategia de Sostenibilidad 2013–2014 and CIDEPRO) for financial support

    Metabolic Signatures of Cryptosporidium parvum-Infected HCT-8 Cells and Impact of Selected Metabolic Inhibitors on C. parvum Infection under Physioxia and Hyperoxia

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    Cryptosporidium parvum is an apicomplexan zoonotic parasite recognized as the second leading-cause of diarrhoea-induced mortality in children. In contrast to other apicomplexans, C. parvum has minimalistic metabolic capacities which are almost exclusively based on glycolysis. Consequently, C. parvum is highly dependent on its host cell metabolism. In vivo (within the intestine) infected epithelial host cells are typically exposed to low oxygen pressure (1–11% O2, termed physioxia). Here, we comparatively analyzed the metabolic signatures of C. parvum-infected HCT-8 cells cultured under both, hyperoxia (21% O2), representing the standard oxygen condition used in most experimental settings, and physioxia (5% O2), to be closer to the in vivo situation. The most pronounced effect of C. parvum infection on host cell metabolism was, on one side, an increase in glucose and glutamine uptake, and on the other side, an increase in lactate release. When cultured in a glutamine-deficient medium, C. parvum infection led to a massive increase in glucose consumption and lactate production. Together, these results point to the important role of both glycolysis and glutaminolysis during C. parvum intracellular replication. Referring to obtained metabolic signatures, we targeted glycolysis as well as glutaminolysis in C. parvum-infected host cells by using the inhibitors lonidamine [inhibitor of hexokinase, mitochondrial carrier protein (MCP) and monocarboxylate transporters (MCT) 1, 2, 4], galloflavin (lactate dehydrogenase inhibitor), syrosingopine (MCT1- and MCT4 inhibitor) and compound 968 (glutaminase inhibitor) under hyperoxic and physioxic conditions. In line with metabolic signatures, all inhibitors significantly reduced parasite replication under both oxygen conditions, thereby proving both energy-related metabolic pathways, glycolysis and glutaminolysis, but also lactate export mechanisms via MCTs as pivotal for C. parvum under in vivo physioxic conditions of mammals
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