Perceived risk and trust associated with purchasing at electronic marketplaces

Understanding consumer behaviour is of vital importance to consumer-oriented e-business models today. In this paper, we study the relationships between consumer perceptions of risk and trust and the attitude towards purchasing at a consumer-to-consumer electronic marketplace (EM). Typical for EM settings is that consumer behaviour is subject to perceptions of the selling party as well as of the institutional structures of the intermediary that is operating the EM. Building upon the well-established literature of trust, we consider the concepts of intermediary trust and seller trust. We extend this categorisation by introducing the concepts of intermediary risk and seller risk. We developed measurement instruments for intermediary risk and seller risk. All measurement scales have acceptable alphas and are unidimensional. An empirical study is conducted to explore the relationships between the risk and trust types and consumer purchase attitude. The results reveal significant, direct effects of seller trust and seller risk. Second-order effects of intermediary trust and intermediary risk are investigated and reported. The paper concludes with general observations and recommendations for research and practice.     

Influence of drying on the content of sugars in wet processed green Arabica coffees

When wet processed coffee beans are dried, the resulting decrease in the water potential induces various metabolic responses. This study was aimed at elucidating the impact of these reactions on the composition of sugars, representing potential aroma precursors. Wet processed green coffees were dried under defined conditions, and the relevant sugars were analysed. Special emphasis was put on the influence of the drying regime, i.e. continuous dryings and such interrupted by pauses in order to mimic sun dryings.     

Influence of processing on the content of sugars in green Arabica coffee beans

Quantitative analyses of low molecular sugars in green coffees (Coffea arabica L. var. Acaià) that were processed in parallel either by the traditional wet or the traditional dry method, revealed a close correlation between the kind of post-harvest treatment and the contents of fructose and glucose. While in washed coffee beans (wet processing) only low amounts of these both hexoses were present, those in unwashed coffees (dry processing) were significantly higher. Model-processing experiments in the laboratory confirmed these findings. Moreover, a comparison with the untreated controls revealed that the low levels of both sugars are the consequence of a decrease in the case of wet processing, whereas they remained unchanged or even increased in the case of dry processing. Further minor sugars are also affected by post-harvest treatment. The amounts of galactose, arabinose and mannose show a similar arrangement as those for glucose and fructose, although their overall concentration is about 100-fold lower. Sucrose, the major low molecular sugar in green coffee beans, is not significantly affected by coffee processing. The influence of an active seed metabolism on the observed alterations of the sugar concentrations is discussed.     

Satisfaction with virtual worlds: An integrated model of experiential value

Although virtual worlds increasingly attract users today, few studies have addressed what satisfies virtual world users. We therefore defined and tested an integrated model of experiential system value and virtual world satisfaction. Drawing upon expectancy-value and cognitive evaluation theories, four important facets of experiential system value were hypothesized as determinants of virtual world satisfaction. Structural equation modeling was employed on a sample of 567 users of the virtual world Second Life. Direct and indirect effects were tested and are reported. Theoretical and practical implications are discussed.     

Sulfate determines the glucosinolate concentration of horseradish in vitro plants (Armoracia rusticana Gaertn., Mey. & Scherb.)

BACKGROUND: Horseradish plants (Armoracia rusticana) contain high concentrations of glucosinolates. Former studies have revealed that Armoracia plants cultivated in vitro have markedly lower glucosinolate concentrations than those grown in soils. Yet, these studies neglected that the sulfate concentration in the growth medium may have had a strong impact on glucosinolate metabolism. Accordingly, in this study horseradish in vitro plants were cultivated with differing sulfate concentrations and the glucosinolate concentrations were quantified by ion pair HPLC. RESULTS: Cultivation in 1.7 mmol L^?1 sulfate (as used in the prior studies) resulted in the accumulation of 16.2 µmol g^?1 DW glucosinolates, while the glucosinolate concentration increased to more than 23 µmol g^?1 DW when 23.5 mmol L^?1 sulfate was used in the medium. Correspondingly, the glucosinolate concentration decreased to 1.6 µmol g^?1 DW when sulfate concentration was lowered to 0.2 mmol L^?1. CONCLUSION: Since the glucosinolate accumulation in relation to the sulfate concentration follows a typical saturation curve, we deduce that the availability of sulfate determines the glucosinolate concentration in horseradish in vitro plants. © 2012 Society of Chemical Industry     

Microstructures of YSZ and CGO Thin Films Deposited by Spray Pyrolysis: Influence of Processing Parameters on the Porosity

Microstructures of yttria‐stabilized zirconia (YSZ) thin films deposited by spray pyrolysis at 370 °C on sapphire are investigated. The as‐deposited films are predominantly amorphous and crystallize upon heating at temperatures above 370 °C, developing grains in the range of 5 nm to several 100 nm. During post‐deposition heat treatment up to 800 °C, ～ 50 vol% porosity develops in the center of the films with gradients towards almost dense interfaces to the air and substrate. The reason for this porosity is the decomposition of residues from the precursor and the free volume liberated due to crystallization. Dense YSZ thin films consisting of one monolayer of grains are obtained with annealing temperatures exceeding 1200 °C. In gadolinium‐doped‐ceria (CGO) thin films similar microstructures and porosity are found after low‐temperature heat treatments indicating that the precursor residues due to the deposition method are the main cause of the porosity. Grain growth stagnation in annealed thin films is observed in both the YSZ and in CGO thin films. Stagnating grain growth in the thin films is rather caused by reduced grain boundary mobility, here predominately due to a “secondary phase”, i.e., pores, than to other effects. The stagnation ceases at higher annealing temperatures after densification has taken place.     

Influence of processing on the generation of γ-aminobutyric acid in green coffee beans

A determination of the concentrations of free amino acids in differently processed green coffees indicated the nonprotein amino acid -aminobutyric acid (GABA), a well-known plant stress metabolite, to be present in raw coffee beans (Coffea arabica L.) in significantly varying amounts. The GABA content of unwashed Arabica beans (green coffee produced by the dry processing method) was always markedly higher than that of washed Arabicas (wet processing method) as well as that of untreated seeds. This result underlined the assumption that during postharvest treatment a significant metabolism occurs within coffee seeds. A putative relation between drought stress of the coffee seeds and postharvest treatment methods is discussed. The GABA content of green coffee beans may serve as a potent tool to characterize the type of postharvest treatment applied in coffee processing.     

Understanding users’ motivations to engage in virtual worlds: A multipurpose model and empirical testing

Despite the growth and commercial potential of virtual worlds, relatively little is known about what drives users’ motivations to engage in virtual worlds. This paper proposes and empirically tests a conceptual model aimed at filling this research gap. Given the multipurpose nature of virtual words the model integrates extrinsic and intrinsic motivation as behavioral determinants. By making use of the literature on information system value and motivation theory four important system-specific virtual world characteristics (economic value, ease of use, escapism, visual attractiveness) are added as motivational drivers. Using structural equation modeling on a sample of 846 users of the virtual world Second Life the hypotheses were tested. The results support the model; they confirm the role of extrinsic and intrinsic motivation as behavioral determinants and show how and to what extent the four system-specific elements function as motivational basis. Implications for research and practice are discussed.