Modeling Consumer Adoption and Usage of Value-Added Mobile Services

In recent years, the mobile telecommunications market has been very dynamic in terms of innovations. Mobile service providers continuously invest in new technologies and introduce many new mobile services for consumers, such as MMS and web services. However, adoption rates are often not very high, which makes it difficult for firms to get return on their technology investments. In this thesis we investigate the individual consumer adoption of new mobile services and consider a range of antecedents and possible moderators. Most importantly, we study the effects of different types of marketing communications on individual adoption timing, and the moderating effect of cultural values on adoption behavior across countries. In addition, we consider the next step in the adoption process: postadoption usage, which has received little attention in the adoption literature so far. In a longitudinal study, we investigate the effect of adoption timing on consumer usage patterns after the adoption of a new mobile service. By taking customer and relationship characteristics into consideration in each study, we also contribute to the customer management literature. We show that relationship characteristics can have a significant impact on adoption behavior and that a loyal and experienced customer can be a valuable asset to companies that introduce a new service

Teacher professional learning and development in the context of educational innovations in higher education: A typology of practices

Higher education (HE) is engaged in a variety of educational innovations, as well as professional development initiatives (PDIs) to support teachers in attaining the required expertise. To improve teacher professional learning and development (PLD) and innovation processes, it is important to understand whether, how and why different PLD practices work for different innovations, contexts and populations. However, research is characterized by descriptive, single case studies and lacks a common framework to relate research findings. To address this shortcoming, this study collected and compared a wide variety of cases to develop a typology of practices. The results showed that educational innovations and teacher PLD were typically configured in three ways: (1) the focus is on implementing a new form of education and teacher learning is used as a means to this end, (2) the focus is on teachers’ professional learning and the educational innovations are spin-offs, and (3) the focus is on stimulating innovations and teacher learning is a side-effect. These types of configurations differed regarding the educational innovation, required teacher expertise, professional development initiatives, teacher learning, and outcome measures. The typology serves as a framework that may help to reflect on practices, bridge disciplines, and formulate hypotheses for future research

Transient foaming behavior of aqueous alcohol solutions as related to their dilational surface properties

The foamability of aqueous alcohol solutions can be measured by continuously sparging air in a closed loop through the solution under standard conditions. The amount of foam produced in the steady state is taken as a measure for the foamability. Aqueous alcohol solutions show transient foaming behavior. This can be explained by assuming that, due to lack of disjoining pressure, thin aqueous alcohol films collapse when due to drainage a critical film thickness has been reached. This means that the drainage rate of these films determines to a large extent the lifetime of these films. Film drainage can be slowed down by surface tension gradients opposing the liquid flow in the film. The ability of aqueous alcohol solutions to generate a surface tension gradient can be measured by means of the overflowing cylinder technique. By changing the alcohol concentration for ethanol, 1-butanol, 1-hexanol, and 1-octanol it is found that both the foamability and the ability to generate a surface tension gradient pass over a maximum value at an alcohol concentration which is characteristic for the alcohol considered. This alcohol concentration coincides with the alcohol content at which a maximum in the ability to generate a surface tension gradient is found. It is concluded that the transient foaming behavior of these aqueous alcohol solutions is mainly determined by their ability to generate a surface tension gradient

Afucosylated IgG characterizes enveloped viral responses and correlates with COVID-19 severity

Immunoglobulin G (IgG) antibodies are crucial for protection against invading pathogens. A highly conserved N-linked glycan within the IgG-Fc tail, which is essential for IgG function, shows variable composition in humans. Afucosylated IgG variants are already used in anticancer therapeutic antibodies for their increased activity through Fc receptors (FcgRIIIa). Here, we report that afucosylated IgG (approximately 6% of total IgG in humans) are specifically formed against enveloped viruses but generally not against other antigens. This mediates stronger FcgRIIIa responses but also amplifies brewing cytokine storms and immune-mediated pathologies. Critically ill COVID-19 patients, but not those with mild symptoms, had high concentrations of afucosylated IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), amplifying proinflammatory cytokine release and acute phase responses. Thus, antibody glycosylation plays a critical role in immune responses to enveloped viruses, including COVID-19