986 resultados para Cisneros, Sandra


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The paper explores the effect of customer satisfaction with online supporting services on loyalty to providers of an offline core service. Supporting services are provided to customers before, during, or after the purchase of a tangible or intangible core product, and have the purpose of enhancing or facilitating the use of this product. The internet has the potential to dominate all other marketing channels when it comes to the interactive and personalised communication that is considered quintessential for supporting services. Our study shows that the quality of online supporting services powerfully affects satisfaction with the provider and customer loyalty through its effect on online value and enjoyment. Managerial implications are provided.

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Målet för Pro Gradu-avhandlingen är att undersöka hur Europeiska unionen (EU) marknadsförs genom användningen av värderande adjektiv i tre genrer av skriftlig kommunikation från EU till medlemsstaternas medborgare. Undersökningen är inriktad på tre forskningsfrågor: hur marknadsföringen av EU syns i användningen av värderande adjektiv i de tre genrerna, vilka de centrala skillnaderna mellan de tre genrerna är gällande användningen av värderande adjektiv, samt på vilket sätt texterna uppfyller sitt kommunikativa syfte, nämligen att informera allmänheten om EU:s verksamhet och marknadsföra EU som en giltig och handlingskraftig union. Den teoretiska ramen för undersökningen grundar sig på genreanalys, kommunikationsteori och teorier om hur författarens värdering (stance) syns i texter. Skillnaden mellan genre, texttyp och register diskuteras, och teoridelen redogör även för begreppet diskurssamfund, dvs. den grupp personer som i ett yrkesmässigt eller institutionellt sammanhang producerar och använder sig av en genre enligt dess kommunikativa konventioner. Materialet behandlas även utgående från Egon Werlichs indelning av texttyper i deskriptiva, narrativa, expositära, argumentativa och instruktiva texter. Materialet består av tre delar som representerar var sin genre: informationsbroschyrer, pressmeddelanden och den Allmänna rapporten om Europeiska unionens verksamhet, som utges av EU varje år. Storleken på varje del av materialet varierar mellan 20 000 - 30 000 ord. Materialet har valts på basis av de teman texterna behandlar, och kriterierna för urvalet är bl.a. att texterna behandlar ämnen som har anknytning till medborgarnas vardag, att de är riktade till allmänheten, och att de finns tillgängliga på Internet. Undersökningen är genomförd som en kvalitativ genreanalys. Materialet analyseras först utgående från kontexten och det samhälleliga sammanhanget enligt Vijay K. Bhatias metodik för analys av obekanta genrer. Det kommunikativa syftet, författaren och den tilltänkta läsarkretsen, dvs. målgruppen för kommunikationen, fastställs. Värderande adjektiv som uttrycker författarens hållning har plockats ur texten manuellt och med hjälp av konkordansprogrammet AntConc, och placerats i 16 kategorier enligt de värden de uttrycker. Varje genre analyseras sedan språkligt med utgångspunkt i adjektivlistorna, varefter resultaten jämförs med varandra. Undersökningen visar att pressmeddelandena innehåller det största antalet värderande adjektiv, medan informationsbroschyrerna innehåller det minsta antalet värderande adjektiv. Den Allmänna rapporten om Europeiska unionens verksamhet innehåller delar med tätt förekommande värderande adjektiv, i synnerhet i stycken som behandlar mer kontroversiella ämnen. I alla tre genrer sammanfaller ett högt antal värderande adjektiv med argumentativ text, och argumentativ text förekommer främst då ämnet som diskuteras rör sig på en mer abstrakt nivå, t.ex. om EU:s värderingar och grundläggande principer, eller då texten behandlar sådan politik som delar allmänhetens uppfattning. För EU utgör alla tre genrer viktiga kanaler för kommunikationen till medlemsstaternas medborgare, och EU kan genom sitt informationsmaterial och sina officiella publikationer informera om, förklara och marknadsföra sin verksamhet på ett sätt som avser att upprätthålla och förbättra EU:s image. Utarbetandet av lämpliga texter är ändå krävande på grund av den heterogena målgruppen, och det är en utmaning i sig att få fram rätt budskap bland det stora utbudet information som finns tillgängligt på Internet.

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Gallic acid (GA), a key intermediate in the synthesis of plant hydrolysable tannins, is also a primary anti-inflammatory, cardio-protective agent found in wine, tea, and cocoa. In this publication, we reveal the identity of a gene and encoded protein essential for GA synthesis. Although it has long been recognized that plants, bacteria, and fungi synthesize and accumulate GA, the pathway leading to its synthesis was largely unknown. Here we provide evidence that shikimate dehydrogenase (SDH), a shikimate pathway enzyme essential for aromatic amino acid synthesis, is also required for GA production. Escherichia coli (E. coli) aroE mutants lacking a functional SDH can be complemented with the plant enzyme such that they grew on media lacking aromatic amino acids and produced GA in vitro. Transgenic Nicotiana tabacum lines expressing a Juglans regia SDH exhibited a 500% increase in GA accumulation. The J. regia and E. coli SDH was purified via overexpression in E. coli and used to measure substrate and cofactor kinetics, following reduction of NADP(+) to NADPH. Reversed-phase liquid chromatography coupled to electrospray mass spectrometry (RP-LC/ESI-MS) was used to quantify and validate GA production through dehydrogenation of 3-dehydroshikimate (3-DHS) by purified E. coli and J. regia SDH when shikimic acid (SA) or 3-DHS were used as substrates and NADP(+) as cofactor. Finally, we show that purified E. coli and J. regia SDH produced GA in vitro.

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Staphylococcus aureus is an opportunistic pathogen that rapidly acquires resistance to frontline antibiotics. The characterization of novel protein targets from this bacterium is thus an important step towards future therapeutic strategies. Here, the crystal structure of an amidohydrolase, SACOL0085, from S. aureus COL is described. SACOL0085 is a member of the M20D family of peptidases. Unlike other M20D peptidases, which are either monomers or dimers, SACOL0085 adopts a butterfly-shaped homotetrameric arrangement with extensive intersubunit interactions. Each subunit of SACOL0085 contains two Mn2+ ions at the active site. A conserved cysteine residue at the active site distinguishes M20D peptidases from other M20 family members. This cysteine, Cys103, serves as bidentate ligand coordinating both Mn2+ ions in SACOL0085.

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Cu2SnS3 films have been processed by the sol-gel route. Differential Scanning Calorimetry (DSC) study was done to observe the phase transformations and to ascertain the deposition temperature. X-ray diffraction (XRD) confirms the phase formation of Cu2SnS3. The texture coefficient analysis shows the preferential orientation of the (112) facet. Scanning electron microscopy reveals the morphology of the film Energy Dispersive Spectroscopy (EDS) was used for compositional studies. Raman spectrum shows the peaks corresponding to the tetragonal phase of Cu2SnS3.

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1. The relationship between species richness and ecosystem function, as measured by productivity or biomass, is of long-standing theoretical and practical interest in ecology. This is especially true for forests, which represent a majority of global biomass, productivity and biodiversity. 2. Here, we conduct an analysis of relationships between tree species richness, biomass and productivity in 25 forest plots of area 8-50ha from across the world. The data were collected using standardized protocols, obviating the need to correct for methodological differences that plague many studies on this topic. 3. We found that at very small spatial grains (0.04ha) species richness was generally positively related to productivity and biomass within plots, with a doubling of species richness corresponding to an average 48% increase in productivity and 53% increase in biomass. At larger spatial grains (0.25ha, 1ha), results were mixed, with negative relationships becoming more common. The results were qualitatively similar but much weaker when we controlled for stem density: at the 0.04ha spatial grain, a doubling of species richness corresponded to a 5% increase in productivity and 7% increase in biomass. Productivity and biomass were themselves almost always positively related at all spatial grains. 4. Synthesis. This is the first cross-site study of the effect of tree species richness on forest biomass and productivity that systematically varies spatial grain within a controlled methodology. The scale-dependent results are consistent with theoretical models in which sampling effects and niche complementarity dominate at small scales, while environmental gradients drive patterns at large scales. Our study shows that the relationship of tree species richness with biomass and productivity changes qualitatively when moving from scales typical of forest surveys (0.04ha) to slightly larger scales (0.25 and 1ha). This needs to be recognized in forest conservation policy and management.

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The thin films of Cu2ZnSnS4 (CZTS) were grown by co-sputtering further the structural, optical and electrical properties were analyzed and confirmed the CZTS phase formation. The photo response of CZTS in near IR photodectection has been demonstrated. The detector response was measured employing both the IR lamp and IR laser illuminations. The calculated growth and decay constants were 130 m sec and 700 m sec followed by the slower components upon lamp illumination. The external quantum efficiency of 15%, responsivity of 13 AW(-1) makes CZTS a suitable candidate for the IR photodectection.

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Imaging thick specimen at a large penetration depth is a challenge in biophysics and material science. Refractive index mismatch results in spherical aberration that is responsible for streaking artifacts, while Poissonian nature of photon emission and scattering introduces noise in the acquired three-dimensional image. To overcome these unwanted artifacts, we introduced a two-fold approach: first, point-spread function modeling with correction for spherical aberration and second, employing maximum-likelihood reconstruction technique to eliminate noise. Experimental results on fluorescent nano-beads and fluorescently coated yeast cells (encaged in Agarose gel) shows substantial minimization of artifacts. The noise is substantially suppressed, whereas the side-lobes (generated by streaking effect) drops by 48.6% as compared to raw data at a depth of 150 mu m. Proposed imaging technique can be integrated to sophisticated fluorescence imaging techniques for rendering high resolution beyond 150 mu m mark. (C) 2013 AIP Publishing LLC.

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Theoretical studies exist to compute the atomic arrangement in gold nanowires and the influence on their electronic behavior with decreasing diameter. Experimental studies, e.g., by transmission electron microscopy, on chemically synthesized ultrafine wires are however lacking owing to the unavailability of suitable protocols for sample preparation and the stability of the wires under electron beam irradiation. In this work, we present an atomic scale structural investigation on quantum single crystalline gold nanowires of 2 nm diameter, chemically prepared on a carbon film grid. Using low dose aberration-corrected high resolution (S)TEM, we observe an inhomogeneous strain distribution in the crystal, largely concentrated at the twin boundaries and the surface along with the presence of facets and surface steps leading to a noncircular cross section of the wires. These structural aspects are critical inputs needed to determine their unique electronic character and their potential as a suitable catalyst material. Furthermore, electron-beam-induced structural changes at the atomic scale, having implications on their mechanical behavior and their suitability as interconnects, are discussed.

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The temperature dependent electrical properties of the dropcasted Cu2SnS3 films have been measured in the temperature range 140 K to 317 K. The log I versus root V plot shows two regions. The region at lower bias is due to electrode limited Schottky emission and the higher bias region is due to bulk limited Poole Frenkel emission. The ideality factor is calculated from the ln I versus V plot for different temperatures fitted with the thermionic emission model and is found to vary from 6.05 eV to 12.23 eV. This large value is attributed to the presence of defects or amorphous layer at the Ag / Cu2SnS3 interface. From the Richardson's plot the Richardson's constant and the barrier height were calculated. Owing to the inhomogeneity in the barrier heights, the Richardson's constant and the barrier height were also calculated from the modified Richardson's plot. The I-V-T curves were also fitted using the thermionic field emission model. The barrier heights were found to be higher than those calculated using thermionic emission model. From the fit of the I-V-T curves to the field emission model, field emission was seen to dominate in the low temperature range of 140 K to 177 K. The temperature dependent current graphs show two regions of different mechanisms. The log I versus 1000/T plot gives activation energies E-a1 = 0.367095 - 0.257682 eV and E-a2 = 0.038416 - 0.042452 eV. The log ( I/T-2) versus 1000/T graph gives trap depths Phi(o1) = 0.314159 - 0.204752 eV and Phi(o2) = 0.007425- 0.011163 eV. With increasing voltage the activation energy E-a1 and the trap depth Phi(o1) decrease. From the ln (IT1/ 2) versus 1/T-1/ 4 graph, the low temperature region is due to variable range hopping mechanism and the high temperature region is due to thermionic emission. (C) 2014 Author(s).

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Long-term surveys of entire communities of species are needed to measure fluctuations in natural populations and elucidate the mechanisms driving population dynamics and community assembly. We analysed changes in abundance of over 4000 tree species in 12 forests across the world over periods of 6-28years. Abundance fluctuations in all forests are large and consistent with population dynamics models in which temporal environmental variance plays a central role. At some sites we identify clear environmental drivers, such as fire and drought, that could underlie these patterns, but at other sites there is a need for further research to identify drivers. In addition, cross-site comparisons showed that abundance fluctuations were smaller at species-rich sites, consistent with the idea that stable environmental conditions promote higher diversity. Much community ecology theory emphasises demographic variance and niche stabilisation; we encourage the development of theory in which temporal environmental variance plays a central role.

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Global change is impacting forests worldwide, threatening biodiversity and ecosystem services including climate regulation. Understanding how forests respond is critical to forest conservation and climate protection. This review describes an international network of 59 long-term forest dynamics research sites (CTFS-ForestGEO) useful for characterizing forest responses to global change. Within very large plots (median size 25ha), all stems 1cm diameter are identified to species, mapped, and regularly recensused according to standardized protocols. CTFS-ForestGEO spans 25 degrees S-61 degrees N latitude, is generally representative of the range of bioclimatic, edaphic, and topographic conditions experienced by forests worldwide, and is the only forest monitoring network that applies a standardized protocol to each of the world's major forest biomes. Supplementary standardized measurements at subsets of the sites provide additional information on plants, animals, and ecosystem and environmental variables. CTFS-ForestGEO sites are experiencing multifaceted anthropogenic global change pressures including warming (average 0.61 degrees C), changes in precipitation (up to +/- 30% change), atmospheric deposition of nitrogen and sulfur compounds (up to 3.8g Nm(-2)yr(-1) and 3.1g Sm(-2)yr(-1)), and forest fragmentation in the surrounding landscape (up to 88% reduced tree cover within 5km). The broad suite of measurements made at CTFS-ForestGEO sites makes it possible to investigate the complex ways in which global change is impacting forest dynamics. Ongoing research across the CTFS-ForestGEO network is yielding insights into how and why the forests are changing, and continued monitoring will provide vital contributions to understanding worldwide forest diversity and dynamics in an era of global change.

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The Al:ZnO/Cu2SnS3 semiconductor heterojunction was fabricated. The structural and optical properties of the semiconductor materials were studied. The band offset at the Al:ZnO/Cu2SnS3 heterojunction was studied using X-ray photoelectron spectroscopy technique. From the measurement of the core level energies and valence band maximum of the constituent elements, the valence band offset was calculated to be -1.1 +/- 0.24 eV and the conduction band offset was 0.9 +/- 0.34 eV. The band alignment at the heterojunction was found to be of type-I. The study of Al:ZnO/Cu2SnS3 heterojunction is useful for solar cell applications. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.