11,192 research outputs found

    Comparison of LANDSAT-2 and field spectrometer reflectance signatures of south Texas rangeland plant communities

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    The accuracy was assessed for an atmospheric correction method that depends on clear water bodies to infer solar and atmospheric parameters for radiative transfer equations by measuring the reflectance signature of four prominent south Texas rangeland plants with the LANDSAT satellite multispectral scanner (MSS) and a ground based spectroradiometer. The rangeland plant reflectances produced by the two sensors were correlated with no significant deviation of the slope from unity or of the intercept from zero. These results indicated that the atmospheric correction produced LANDSAT MSS estimates of rangeland plant reflectances that are as accurate as the ground based spectroradiometer

    SENSING IMMOBILIZED MOLECULES OF STREPTAVIDIN ON A SILICON SURFACE BY MALDI-TOF MASS SPECTROMETRY AND FLUORESCENCE MICROSCOPY

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    Indexación: Web of Science; Scielo.A hydrogen-terminated Si (111) surface was modified to form an aminoterminated monolayer for immobilization of streptavidin. Cleavage of an N-(ω-undecylenyl)-phthalimide covered surface using hidrazine yields an amino group-modified surface, which serves as a substrate for the attachment of biotin and subsequently streptavidin. We used surface analytical techniques to characterize the surface and to control the course of functionalization before the immobilization of streptavidin. To confirm the presence of the streptavidin Texas red on the surface two powerful techniques available in a standard biochemical laboratory are used, Fluorescence Microscopy and MALDI-TOF that allow us to detect and determine the immobilized streptavidin. This work provides an avenue for the development of devices in which the exquisite binding specificity of biomolecular recognition is directly coupled to a biosensor. In addition, we have demonstrated that MALDI-TOF and fluorescence microscopy are useful techniques for the characterization of silicon functionalized surfaces.http://ref.scielo.org/gm87c

    Investigation of HNCO isomers formation in ice mantles by UV and thermal processing: an experimental approach

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    Current gas phase models do not account for the abundances of HNCO isomers detected in various environments, suggesting a formation in icy grain mantles. We attempted to study a formation channel of HNCO and its possible isomers by vacuum-UV photoprocessing of interstellar ice analogues containing H2_2O, NH3_3, CO, HCN, CH3_3OH, CH4_4, and N2_2 followed by warm-up, under astrophysically relevant conditions. Only the H2_2O:NH3_3:CO and H2_2O:HCN ice mixtures led to the production of HNCO species. The possible isomerization of HNCO to its higher energy tautomers following irradiation or due to ice warm-up has been scrutinized. The photochemistry and thermal chemistry of H2_2O:NH3_3:CO and H2_2O:HCN ices was simulated using the Interstellar Astrochemistry Chamber (ISAC), a state-of-the-art ultra-high-vacuum setup. The ice was monitored in situ by Fourier transform mid-infrared spectroscopy in transmittance. A quadrupole mass spectrometer (QMS) detected the desorption of the molecules in the gas phase. UV-photoprocessing of H2_2O:NH3_3:CO/H2_2O:HCN ices lead to the formation of OCN^- as main product in the solid state and a minor amount of HNCO. The second isomer HOCN has been tentatively identified. Despite its low efficiency, the formation of HNCO and the HOCN isomers by UV-photoprocessing of realistic simulated ice mantles, might explain the observed abundances of these species in PDRs, hot cores, and dark clouds

    Inclusion Program for Raising the Economic Income of the Wholesale Market Traders of Riobamba, Ecuador

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    The problems seen in the Riobamba Wholesale Market are related to the concentration of the financial system in urban areas. Large sectors in need have been relegated, either because of their economic condition or their place of residence. The difficulty for traders to get loans restricts them from taking steps toward business improvement and undertaking new projects. This study aims to propose a financial inclusion program to promote an increase in the economic income of wholesale traders in Riobamba. The study uses a qualitative and quantitative approach. The information was collected through structured surveys with multiple choice questions directed toward the sectoral distribution of traders. A representative sample was extracted from the total population of the traders registered in the Riobamba Wholesale Market. The results showed that traders are agents of entrepreneurship and require loans to expand or manage new businesses with the capacity to repay. Furthermore, there is a willingness for partnership and adoption of policies of a social and solidarity-based inclusive economy following the principles of plural economy, reciprocity, social sustainability, ecological sustainability, and social efficiency. In addition, they rely on cooperative work. The greatest interest in the Financial Inclusion Program is seen in the tomato, fruit, corn, and potato trades, which include the largest number of merchants. They expect the new program to include ATM services, mobile banking, and savings plans. In conclusion, the financial inclusion program acts by offering services that are related to the banks or credit unions, the ones that offer the greatest advantages. It is a great alternative to improve the economic incomes of traders in the Riobamba market. Keywords: financial inclusion, social and solidarity economy. Resumen Los problemas que se aprecian en el Mercado Mayorista de Riobamba están relacionados con la concentración del sistema financiero en centros urbanos, relegando a grandes sectores necesitados ya sea por su condición económica como por su lugar de residencia. La dificultad de los comerciantes para acceder a créditos no les permite mejorar sus negocios y menos aún emprender nuevos proyectos. El objetivo principal de la investigación fue plantear un programa de inclusión financiera que promueva el incremento de ingresos económicos, el mismo que estará sujeto a su hipótesis. Esta investigación tiene enfoque cuali-cuantitativo, cuya información se recabó por medio de encuestas estructuradas con preguntas de opción múltiple e información secundaria sobre la distribución sectorial de los comerciantes. La población total de comerciantes registrados en el Mercado Mayorista Riobamba de la cual se extrajo una muestra representativa, donde los resultados indican que los comerciantes son agentes de emprendimiento que requieren de créditos para ampliar o gestionar nuevos negocios, tienen capacidad para solventar pagos y que existe buena disposición para la asociatividad y las políticas de la economía social y solidaria e inclusiva, con base a la economía plural, la reciprocidad, la sustentabilidad social, la sostenibilidad ecológica y la eficiencia social, además, confían en el trabajo cooperativo. Quienes muestran mayor interés en el Programa de Inclusión Financiera son los sectores del comercio de tomates, frutas, choclos y papas, que corresponden al mayor número de mercaderes, los cuales esperan que el nuevo programa incluya los servicios de cajeros automáticos, banca móvil y planes de ahorros. En conclusión, el programa de inclusión financiera actúa mediante la oferta de servicios, los mismos que se relacionan con los bancos o cooperativas de ahorro y crédito que mayores ventajas ofrezcan. Es una magnífica alternativa para mejorar los ingresos económicos de los comerciantes del Mercado de Riobamba. Palabras Clave: economía social y solidaria, inclusión financiera

    Flavor Delta(54) in SU(5) SUSY Model

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    We design a supersymmetric SU (5) GUT model using \Delta (54), a finite non-abelian subgroup of SU (3)f . Heavy right handed neutrinos are introduced which transform as three-dimensional repre-sentation of our chosen family group. The model successfully reproduces the mass hierarchical mass structures of the Standard Model, and the CKM mixing matrix. It then provides predictions for the light neutrino with a normal hierarchy and masses such that m{\nu},1 \approx 5\times10-3 eV, m{\nu}, 2 \approx 1\times 10-2 eV, and m{\nu},3 \approx 5 \times 10-2 eV. We also provide predictions for masses of the heavy neutrinos, and correc- tions to the tri-bimaximal matrix that fit within experimental limits, e.g. a reactor angle of -7.31o. A simple modification to our model is introduced at the end and is shown to also produce predictions that fall well within those limits.Comment: 22 page
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