Simultaneous high-resolution pH and spectrophotometric recordings of oxygen binding in native blood microvolumes, link to supplementary material

Oxygen equilibrium curves have been widely used to understand oxygen transport in numerous organisms. A major challenge has been to monitor oxygen binding characteristics and concomitant pH changes as they occur in vivo, in limited sample volumes. Here we report a technique allowing highly resolved and simultaneous monitoring of pH and blood pigment saturation in minute blood volumes. We equipped a gas diffusion chamber with a broad range fibre optic spectrophotometer and a micro-pH optode and recorded changes of pigment oxygenation along PO2 and pH gradients to test the setup. Oxygen binding parameters derived from measurements in only 15 µl of haemolymph from the cephalopod Octopus vulgaris showed low instrumental error (0.93%) and good agreement with published data. Broad range spectra, each resolving 2048 data points, provided detailed insight into the complex absorbance characteristics of diverse blood types. After consideration of photobleaching and intrinsic fluorescence, pH optodes yielded accurate recordings and resolved a sigmoidal shift of 0.03 pH units in response to changing PO2 from 0-21 kPa. Highly resolved continuous recordings along pH gradients conformed to stepwise measurements at low rates of pH changes. In this study we showed that a diffusion chamber upgraded with a broad range spectrophotometer and an optical pH sensor accurately characterizes oxygen binding with minimal sample consumption and manipulation. We conclude that the modified diffusion chamber is highly suitable for experimental biologists who demand high flexibility, detailed insight into oxygen binding as well as experimental and biological accuracy combined in a single set up.

Free Drink or Free Mug? Managing Service Experience with Experiential vs. Material Complimentary Gifts

In the marketplace, complimentary gifts can take the form of experiential elements (e.g., a meal) or material items (e.g., tangible objects such as a mug). We identify these free gifts as a meaningful service design choice that helps service providers innovate service. Specifically, we examine the circumstances under which experiential or material gifts are preferred and generate greater consumer satisfaction, enhancing the overall service experience. Across three experiments, we demonstrate that consumers are generally happier with experiential offerings, and they prefer (and are more satisfied with) experiential offerings on ordinary consumption occasions; experiential elements are believed to further enrich otherwise mundane experiences. However, this experiential advantage disappears for consumers on meaningful and special occasions because of a strong desire to obtain a memory cue that will help them recall the experience. Indeed, the preference for a material item holds only when the gift has the quality to serve as a salient memory marker, but not when it lacks this quality. This research provides insight for managers to take into account consumption occasions or type of consumers (e.g., special occasions, repeat customers) to effectively design service bundles with complimentary gifts and thus better manage overall service experience.

Economic well-being and poverty among the elderly: an analysis based on a collective consumption model

We apply the collective consumption model of Browning, Chiappori and Lewbel (2006) to analyse economic well-being and poverty among the elderly. The model focuses on individual preferences, a consumption technology that captures the economies of scale of living in a couple, and a sharing rule that governs the intra-household allocation of resources. The model is applied to a time series of Dutch consumption expenditure surveys. Our empirical results indicate substantial economies of scale and a wifeís share that is increasing in total expenditures. We further calculated poverty rates by means of the collective consumption model. Collective poverty rates of widows and widowers turn out to be slightly lower than traditional ones based on a standard equivalence scale. Poverty among women (men) in elderly couples, however, seems to be heavily underestimated (overestimated) by the traditional approach. Finally, we analysed the impact of becoming a widow(er). Based on cross-sectional evidence, we find that the drop (increase) in material well-being following the husbandís death is substantial for women in high (low) expenditure couples. For men, the picture is reversed.

Mobile phone consumption and implications for SMS marketing

This paper reports on a Q-methodology study on the consumption of mobile phones and opinions on SMS-marketing, extracted from interpretive interviews and focus groups. The Metaphors Q-sort, developed within a framework of Holt's (1995) four metaphors of consumption, identifies three experiential value clusters in the consumption of mobile phones: the Mobile Pragmatists, the Mobile Connectors and the Mobile Revelers. The SMS-marketing Q-sort identifies two key clusters of subjective opinions on various aspects of SMS-based mobile-marketing. By integrating the findings from these two Q-sorts, we demonstrate that while all three value clusters express positive opinions towards ‘location specific’ and ‘customer initiated contact’ SMS-marketing, there are noticeable differences in how marketers should develop their strategies to maximize the consumers’ perceived experiential value derived from the consumption of their mobile phones. Keywords: mobile phones; experiential consumption: SMS-marketing; Q-methodology

M-technology, Consumption and Gambling: A Conceptualisation of Consumer Vulnerability in an M-gambling Marketplace

Technology imbued m-marketing systems influence the consumptive lives of citizens, by facilitating anytime, anywhere business-to-consumer interactions. Business pundits’ enthusiasm towards mobile services (m-services) has been driven by the promise of a marketspace context involving seamless, business-to-consumer interactions that can be simultaneously impulse-driven, highly entertaining and omnipresent. Arguably, gambling too is impulse-driven, exciting and easily accessible. An important question that needs to be addressed is: how the convergence of mobile technology and gambling will impact the millennial consumer. The authors address this question by examining the contextually bounded interactions between internal and external factors that make mobile phone users potentially vulnerable during m-gambling interactions. By examining key themes that describe the convergence of m-technology and gambling, we clarify the experiential nature of m-gambling and its relationship to consumer vulnerability.