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

Is a single direct MR arthrography series in ABER position as accurate in detecting anteroinferior labroligamentous lesions as conventional MR arthography?

The purpose of this study is to retrospectively compare accuracy of single magnetic resonance (MR) arthrography series in Abduction External Rotation (ABER) with conventional MR arthrography for detection and characterisation of anteroinferior labroligamentous lesions, with arthroscopy as reference standard. Inter-observer variability of both protocols was determined. Institutional review board approval was obtained; informed consent was waived. MR arthrograms, including oblique axial fat suppressed T1-weighted images in ABER position and conventional imaging directions of 250 patients (170 men, 80 women; mean age, 36 years), were retrospectively and independently evaluated by three reviewers. Reviewers were blinded to clinical information and arthroscopic results. Labroligamentous lesions were registered in both ABER and MRa. The lesions were sub-classified (Bankart, Perthes, anterior labrum periosteal sleeve avulsion (ALPSA) or lesions not otherwise specified). Inter-observer agreement was assessed by Kappa statistics for all 250 patients. Ninety-two of 250 patients underwent arthroscopy. Sensitivity, specificity and accuracy of ABER versus conventional MR arthrography were calculated and compared using paired McNemar test. Kappa values of the ABER and conventional MR arthrography ranged from 0.44 to 0.56 and 0.44 to 0.62, respectively. According to arthroscopy, 45 of 92 patients had an intact anteroinferior labrum, and in 44 patients, a labroligamentous lesion (eight Bankart, seven Perthes, 29 ALPSA and three lesions not otherwise specified) was diagnosed. There were no statistically significant differences between ABER and conventional MR arthrography regarding sensitivity (85-89%, 89-96%), specificity (82-91%, 84-89%) and overall accuracy (50-62%, 53-63%). The results of a single MR arthrography series in ABER position are comparable with those of conventional MR arthrography for detecting anteroinferior labroligamentous lesion