447 research outputs found

    The Economic Value of Basin Protection to Improve the Quality and Reliability of Potable Water Supply: Some Evidence from Ecuador

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    This study estimates the willingness to pay (WTP) of Loja’s households to protect two micro-basins that supply over 40 percent of potable water to the city. Results indicate that households have an average WTP of $5.80 per month, which corresponds to a 25 percent increase in the self-reported monthly water bill, to preserve the basins.Basin protection, contingent valuation, Loja, Ecuador, Environmental Economics and Policy, Land Economics/Use,

    Oblique surface waves at an interface of metal-dielectric superlattice and isotropic dielectric

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    We investigate the existence and the dispersion characteristics of surface waves that propagate at an interface between metal-dielectric superlattice and isotropic dielectric. Within the long wavelength limit, when the effective-medium approximation is valid, the superlattice behaves like a uniaxial plasmonic crystal with the main optical axes perpendicular to the metal-dielectric interfaces. We demonstrate that if such a semi-infinite plasmonic crystal is cut normally to the layer interfaces and brought into the contact with semi-infinite dielectric, a new type of surface modes can appear. The propagation of such modes obliquely to the optical axes occurs under favorable conditions that regard thicknesses of the layers, as well as the proper choice of dielectric permittivity of the constituent materials. We show that losses within the metallic layers can be substantially reduced by making the layers sufficiently thin. At the same time, a dramatic enlargement of the range of angles for oblique propagation of the new surface modes is observed. This can lead, however, to the field non-locality and consequently to the failure of the effective-medium approximation.Comment: 4 pages, 3 figure

    Synthesis, In Silico Studies, Antiprotozoal and Cytotoxic Activities of Quinoline‐Biphenyl Hybrids

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    This is the pre-peer reviewed version of the following article: Synthesis, In Silico Studies, Antiprotozoal and Cytotoxic Activities of Quinoline‐Biphenyl Hybrids, which has been published in final form at https://doi.org/10.1002/slct.201903835. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsThe synthesis, in silico studies, antiprotozoal and cytotoxic activities of eleven quinoline‐biphenyl hybrids are described herein. The structure of the synthesized products was elucidated by a combination of spectrometric analyses. The synthesized compounds were evaluated against Plasmodium falciparum, and amastigotes forms both Leishmania (V) panamensis and Trypanosoma cruzi. Cytotoxicity was evaluated against human U‐937 macrophages. 8‐phenylquinoline (4 a) showed similar activity than meglumine antimoniate and 4‐(quinolin‐8‐yl)phenol (4 b) exhibited an activity similar to that of benznidazole. 8‐(3,4‐dimethoxyphenyl) quinoline (4 k) showed the best activity against P. falciparum. Although these compounds were toxic for mammalian U‐937 cells, however they may still have potential to be considered as candidates for drug development because of their antiparasite activity. Molecular docking was used to determine the in silico inhibition of some of the designed compounds against PfLDH and cruzipain, two important pharmacological targets involved in antiparasitic diseases. All hybrids were docked to the three‐dimensional structures of PfLDH and T. cruzi cruzipain as enzymes using AutoDock Vina. Notably, the docking results showed that the most active compounds 4‐(quinolin‐8‐yl)phenol (4 b, CE50: 11.33 μg/mL for T. cruzi) and 8‐(3,4‐dimethoxyphenyl) quinoline (4 k, CE50: 8.84 μg/mL for P. falciparum) exhibited the highest scoring pose (−7.5 and −7.7 kcal/mol, respectively). This result shows a good correlation between the predicted scores with the experimental data profile, suggesting that these ligands could act as competitive inhibitors of PfLDH or T. cruzi cruzipain enzymes, respectively. Finally, in silico ADME studies of the quinoline hybrids showed that these novel compounds have suitable drug‐like properties, making them potentially promising agents for antiprotozoal therapy

    El experimento mago de oz y sus aplicaciones: una mirada retrospectiva

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    En la Lingüística Computacional los corpus han sido uno de los recursos más utilizados para estudiar los diferentes fenómenos lingüísticos. La recopilación de corpus en los cuales se presenta interacción entre el humano y el computador presenta como problema fundamental los errores que se pueden inducir por parte del humano, cuyo lenguaje se simplifica en presencia del computador. Para realizar la recopilación de estos corpus se han empleado los Experimentos Mago de Oz (MDO). En este artículo se muestra una mirada retrospectiva del Experimento Mago de Oz, clasificando sus principales aplicaciones

    Thermal Jeans fragmentation within 1000 AU in OMC-1S

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    We present subarcsecond 1.3 mm continuum ALMA observations towards the Orion Molecular Cloud 1 South (OMC-1S) region, down to a spatial resolution of 74 AU, which reveal a total of 31 continuum sources. We also present subarcsecond 7 mm continuum VLA observations of the same region, which allow to further study fragmentation down to a spatial resolution of 40 AU. By applying a Mean Surface Density of Companions method we find a characteristic spatial scale at ~560 AU, and we use this spatial scale to define the boundary of 19 `cores' in OMC-1S as groupings of millimeter sources. We find an additional characteristic spatial scale at ~2900 AU, which is the typical scale of the filaments in OMC-1S, suggesting a two-level fragmentation process. We measured the fragmentation level within each core and find a higher fragmentation towards the southern filament. In addition, the cores of the southern filament are also the densest (within 1100 AU) cores in OMC-1S. This is fully consistent with previous studies of fragmentation at spatial scales one order of magnitude larger, and suggests that fragmentation down to 40 AU seems to be governed by thermal Jeans processes in OMC-1S.Comment: Accepted to Ap

    Refinamiento del diagrama de clases uml a oracle®9i en atom3

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    El OMG define el refinamiento como el proceso de transformación desde un modelo independiente de la plataforma de implementación hacia un modelo específico de la plataforma de implementación. Las herramientas CASE convencionales han experimentado problemas con este tipo de transformación, debido a la definición estática de los modelos incluidos en ellas, a las dificultades para la definición de reglas de transformación y al pobre rendimiento mostrado por ellas en la obtención de código. Las herramientas MetaCASE han surgido con nuevas capacidades para mejorar el refinamiento en el contexto de la transformación entre modelos. En este artículo se presenta una implementación en AToM3 para refinamiento que transforma un diagrama de clases UML independiente de la plataforma de implementación a un diagrama de clases UML dependiente de la plataforma de implementación Oracle® 9i. Además, se muestra el uso de esta clase de refinamiento con un caso de estudio

    Business information architecture for successful project implementation based on sentiment analysis in the tourist sector

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    In the today's market, there is a wide range of failed IT projects in specialized small and medium-sized companies because of poor control in the gap between the business and its vision. In other words, acquired goods are not being sold, a scenario which is very common in tourism retail companies. These companies buy a number of travel packages from big companies and due to lack of demand for these packages, they expire, becoming an expense, rather than an investment. To solve this problem, we propose to detect the problems that limit a company by re-engineering the processes, enabling the implementation of a business architecture based on sentimental analysis, allowing small and medium-sized tourism enterprises (SMEs) to make better decisions and analyze the information that most possess, without knowing how to exploit it. In addition, a case study was applied using a real company, comparing data before and after using the proposed model in order to validate feasibility of the applied model.This work has been partially funded by the following projects of the Spanish Ministry of Science, Innovation and Universities GROMA (MTM2015-63710-P), MODAS-IN (reference: RTI2018-094269-B-I00), PPI (RTC-2015-3580-7) and UNIKO (RTC-2015-3521-7), and the “methaodos.org” research group at URJC
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