28 research outputs found
Towards an international understanding of the power of celebrity persuasions: a review and a research agenda
Research into advertising using celebrity has been undertaken for nearly 40 years. It has
principally used surveys and experiments to explore how consumers respond to celebrity
advertisements. A recent meta-study of 32 papers has demonstrated that different
populations respond in different ways to celebrity endorsements. Specifically, both US
subjects and college students are more likely to respond in a significant way to the
presence of celebrity than subjects who are not from the US, or who are not studying at
college. Given that the nationality and student status of subjects matter, this article
explores the make up of the samples that have been used to examine celebrity advertising.
The article finds that these samples are not representative of US populations
(because so many are students), nor of populations outside the US (because so few
live beyond it). Furthermore, the history of dominance of US-based student samples, and
the citation practices which keep them circulating in academia, suggests that theories of
celebrity advertising have for a long time been excessively influenced by ideas tested on
this unrepresentative group. This fact will limit the applicability of research into celebrity
advertising to the wider world. I explore whether this matters, and how deficiencies
might be addressed in further research
An Investigation of Market Orientation (MO) and Tourism Small and Medium-Sized Enterprises’ (SMEs) Performance in Developing Countries: A Review of the Literature
Giardia intestinalis thymidine kinase is a high-affinity enzyme crucial for DNA synthesis and an exploitable target for drug discovery
Giardiasis is a diarrheal disease caused by the unicellular parasite Giardia intestinalis, for which metronidazole is the main treatment option. The parasite is dependent on exogenous deoxyribonucleosides for DNA replication and thus is also potentially vulnerable to deoxyribonucleoside analogs. Here, we characterized the G. intestinalis thymidine kinase, a divergent member of the thymidine kinase 1 family that consists of two weakly homologous parts within one polypeptide. We found that the recombinantly expressed enzyme is monomeric, with 100-fold higher catalytic efficiency for thymidine compared to its second-best substrate, deoxyuridine, and is furthermore subject to feedback inhibition by dTTP. This efficient substrate discrimination is in line with the lack of thymidylate synthase and dUTPase in the parasite, which makes deoxy-UMP a dead-end product that is potentially harmful if converted to deoxy-UTP. We also found that the antiretroviral drug azidothymidine (AZT) was an equally good substrate as thymidine and was active against WT as well as metronidazole-resistant G. intestinalis trophozoites. This drug inhibited DNA synthesis in the parasite and efficiently decreased cyst production in vitro, which suggests that it could reduce infectivity. AZT also showed a good effect in G. intestinalis–infected gerbils, reducing both the number of trophozoites in the small intestine and the number of viable cysts in the stool. Taken together, these results suggest that the absolute dependency of the parasite on thymidine kinase for its DNA synthesis can be exploited by AZT, which has promise as a future medication effective against metronidazole-refractory giardiasis