1,161 research outputs found

    Impact of delays on costumers'safety perceptions and behavioral intentions

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    Purpose: The main objective of this paper is to examine how the customers' perceptions of delays and safety relate to each other and to behavioral intentions Design/methodology/approach: We modified a customer satisfaction questionnaire to include questions relating to the constructs we wanted to examine and collaborated with a major international airline to collect data from 797 customers through in-flight surveys. Findings: We obtain three key original findings. First, perceived safety exerts a direct positive effect on behavioral intentions. Second, perceived delays exert an indirect effect mediated by perceived safety. Finally, customers believe operational practices affect both delay and safety. Originality/value: This is the first paper that examines the customer's perspective on two of the most important aspects of airline operations management: delays and safety. Our findings are of great value to managers who want to evaluate the impact of delays and safety on customers and to researches interested in the theoretical relationships between these two constructs.Peer Reviewe

    Caracterización genética de ovinos criollos colombianos

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    ABSTRACT: indigenous breeds are important for poor farmers because of their natural selection against harsh environments and adaptation to regional conditions. However, inbreeding of indigenous sheep populations has increased in Colombia due to indiscriminate cross-breeding with foreign animals and lack of reproductive controls, with subsequent loss in productivity, which poses a great risk for the conservation of valuable genes. Objective: to determine the genetic diversity in Colombian indigenous sheep by using a panel of 10 microsatellite molecular markers. Methods: blood samples from 362 individuals from 43 farms in 11 Colombian provinces were genotyped and analyzed for a panel of 10 microsatellite markers. Results: a total of 134 alleles were found (13.4 alleles/locus on average) with a range of observed and expected heterozygosity of 0.428 to 0.831 and 0.615 to 0.855, respectively, and 0.742 polymorphic information content (PIC). The average Wright F-statistics (FIS ) of the breeds was 0.107, suggesting moderate levels of inbreeding. Colombian sheep showed a low level of genetic differentiation among breeds (FST = 0.054) and STRUCTURE analysis showed complex patterns of admixture in the breeds. Conclusion: overall, Colombian sheep have high genetic variability, which is very important for future conservation programs and genetic improvement.RESUMEN: las razas animales autóctonas son importantes para los agricultores de escasos recursos a causa de su selección natural contra el duro ambiente y su adaptación a condiciones regionales. Sin embargo en Colombia, debido al cruce indiscriminado con razas foráneas y a la falta de control de la reproducción, ha aumentado la consanguinidad en las poblaciones de ovinos criollos y por lo tanto la pérdida en la productividad, lo que supone un gran riesgo para la conservación de genes valiosos. Objetivo: determinar la diversidad genética en razas criollas de ovinos colombianos utilizando análisis por microsatélites. Métodos: se visitaron 43 granjas localizadas en 11 departamentos del país, en las cuales se tomaron muestras de sangre a 362 individuos. Las muestras fueron genotipadas y analizadas para un panel de 10 marcadores microsatélites. Resultados: un total de 134 alelos fueron encontrados (13,4 alelos/locus en promedio), con un rango de heterocigocidad observada y esperada de 0,428 a 0,831 y 0,615 a 0,855, respectivamente, y un contenido de información polimórfica (PIC) promedio de 0,742. El Wright F-statistics (FIS) promedio de las razas evaluadas fue 0,107, lo cual sugiere que las razas tienen niveles moderados de consanguinidad. Las ovejas colombianas presentaron un bajo grado de diferenciación genética entre las distintas razas (FST = 0,054) y el análisis de STRUCTURE mostro complejos patrones de mezcla en las razas estudiadas. Conclusión: en términos generales, las ovejas colombianas presentan una alta variabilidad genética lo cual es muy importante para futuros programas de conservacion y mejoramiento genetico

    Critical Theory and the Loneliness of the Tax Prof

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    This essay, prepared for a symposium on critical theory and tax law, has two goals: to suggest why feminist theory and critical race theory are spreading in taxation and to discuss some dangers of that criticism. The author evaluates three examples of the new criticism: an article on critical race theory by Professors Moran and Whitford; an article on feminist statutory interpretation by Professor Handelman; and a book, Taxing Women, by Professor McCaffery

    Arouca Geopark: geotourists are arriving!

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    The Arouca Geopark, located in the Aveiro district (northern Portugal), originated in 2005 and was formally established in late 2007, under the auspices of Arouca's Municipal Chamber. This ongoing project will soon be submitted to the European and Global Geoparks Networks, making it the second Portuguese geopark inside these networks. During the last three years, an international multidisciplinary team has been working on the rich geodiversity of the area, promoting the inventory and characterization of 36 geological sites, together with the identification of biological and cultural heritage (archaeology, history, ethnography, gastronomy) which are necessary to fulfil the geopark requirements. The link with educational and tourist activities is also progressing, aiming the sustainable development of the region. Among the 36 geological sites subject to preliminary studies and already accessible, two of them are of special international relevance: the Canelas Slate Quarry and its on-site Museum, and the Castanheira Nodular Granite, with a place popularly known as pedras parideiras (= "the stones that give birth", or rather "rocks delivering stones"). The first is an outstanding fossil locality of Darriwilian (Middle Ordovician) age, where giant trilobites (up to 70 cm in size) and trilobite clusters (from several to thousands of specimens) occur in large slabs of shale, recovered during roofing slate quarrying. The Valerio & Figueiredo private company encourages scientific access to its quarry and has built an on-site museum to preserve and disseminate knowledge about trilobites and the Ordovician world. The Geological Interpretation Centre of Canelas, located near the quarry and open since 2006, is one of the main tourist attractions of the Arouca Geopark, having received more than 10,000 visitors in 2007. The Castanheira Granite is a small and very peculiar granite outcrop that contains a remarkable abundance of discoidal biotite nodules ranging from 1−12 cm in diameter, now protected by the Arouca municipality and visited by 15,000 persons during the last year. A popular legend attributes magical properties to these nodules in terms of female fertility, since these dark mineral lumps pop out spontaneously from a creamy-coloured matrix due to differential dilatation during the hot summers. A new interpretation centre will be established in 2008, using an old house close to the outcrop: the "House of Rocks Delivering Stones". The present work is being performed under the project "Identification, Characterization and Conservation of Geological Heritage: a Geoconservation strategy for Portugal" sponsored by the Portuguese Foundation of Science and Technology (PTDC/CTEGEX/64966/2006, years 2007-2009), and is also part of the PATRIORSI project of the Spanish Ministry of Education and Science (CGL2006- 07628/BTE, years 2006-2009)

    Estudo de sensibilidade das previsoes de superficie em Portugal pelo WRF face à variaçao das parametrizaçoes físicas

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    Ponencia presentada en: XXX Jornadas Científicas de la AME y el IX Encuentro Hispano Luso de Meteorología celebrado en Zaragoza, del 5 al 7 de mayo de 2008

    New biotechnological perspectives of a NADH oxidase variant from Thermus thermophilus HB27 as NAD+-recycling enzyme

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    <p>Abstract</p> <p>Background</p> <p>The number of biotransformations that use nicotinamide recycling systems is exponentially growing. For this reason one of the current challenges in biocatalysis is to develop and optimize more simple and efficient cofactor recycling systems. One promising approach to regenerate NAD<sup>+ </sup>pools is the use of NADH-oxidases that reduce oxygen to hydrogen peroxide while oxidizing NADH to NAD<sup>+</sup>. This class of enzymes may be applied to asymmetric reduction of prochiral substrates in order to obtain enantiopure compounds.</p> <p>Results</p> <p>The NADH-oxidase (NOX) presented here is a flavoenzyme which needs exogenous FAD or FMN to reach its maximum velocity. Interestingly, this enzyme is 6-fold hyperactivated by incubation at high temperatures (80°C) under limiting concentrations of flavin cofactor, a change that remains stable even at low temperatures (37°C). The hyperactivated form presented a high specific activity (37.5 U/mg) at low temperatures despite isolation from a thermophile source. Immobilization of NOX onto agarose activated with glyoxyl groups yielded the most stable enzyme preparation (6-fold more stable than the hyperactivated soluble enzyme). The immobilized derivative was able to be reactivated under physiological conditions after inactivation by high solvent concentrations. The inactivation/reactivation cycle could be repeated at least three times, recovering full NOX activity in all cases after the reactivation step. This immobilized catalyst is presented as a recycling partner for a thermophile alcohol dehydrogenase in order to perform the kinetic resolution secondary alcohols.</p> <p>Conclusion</p> <p>We have designed, developed and characterized a heterogeneous and robust biocatalyst which has been used as recycling partner in the kinetic resolution of <it>rac</it>-1-phenylethanol. The high stability along with its capability to be reactivated makes this biocatalyst highly re-useable for cofactor recycling in redox biotransformations.</p

    Chrotopterus auritus (Peters, 1856) (Chiroptera, Phyllostomidae): First Record for the State of Rio Grande Do Norte, Northeastern Brazil

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    Chrotopterus auritus is a phyllostomid bat with a wide distribution in the Neotropics. It has been recorded in Brazil’s 6 biomes but with few records in the Caatinga. We provide the first record of C. auritus for Rio Grande do Norte state, northeastern Brazil, based on records from 2 caves, Três Inchu and Gruta da Carrapateira. The nearest records are ca. 400 km southeast in Ceará state and ca. 350 km northwest in Pernambuco state. Our new records fill the northeastern distributional gap of C. auritus in Brazil and South America
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