Antecedents and outcomes of memorable volunteer tourism experiences

Purpose: This study proposed and tested a new conceptual model of memorable volunteer tourism experiences (MVTEs) by examining the effects of novelty, meaningfulness, experience co-creation and experience intensification on MVTEs. It also examined the relationships among MVTEs, psychological resilience (PR) and behavioural intention (BI), including that between novelty and BI. Design/methodology/approach: The study modelled the proposed relationships by analysing data from an online survey using Amazon Mechanical Turk. In total, 241 responses were used in the data analysis. Findings: This study extended the MVTE construct and included four key antecedents that influence tourists' MVTEs. The study also documented the predictive capability of MVTEs for PR and BI. Practical implications: Volunteer tourism organisations should offer new and diverse activities for volunteer tourists, such as nature conservation, wildlife protection and construction. Originality/value: This is the first study to examine the antecedents and outcomes of MVTEs using the stimuli–organism–response theory

Therapy refractory hypertension in adults: aortic coarctation has to be ruled out

In patients with unexplained hypertension, especially in combination with a cardiac murmur, the presence of an aortic coarctation should always be ruled out given the high morbidity and mortality. However, particularly patients with an isolated coarctation often remain asymptomatic for years and the defect may be unnoticed even until the fifth or sixth decade of life. In the present article, we describe two patients with late detected coarctation to illustrate the clinical consequences, diagnostic clues for earlier detection and current therapeutic options to achieve optimal treatment. The key sign of an aortic coarctation, a difference in arterial blood pressure measured between the upper and lower extremities, should always be examined, followed by echocardiography. We conclude that even in case of a late detected severe coarctation, surgical or percutaneous repair has proven to be feasible and substantially effective, improving quality of life and lowering the risk of further hypertension-associated problems

Determining the electronic performance limitations in top-down fabricated Si nanowires with mean widths down to 4 nm

Silicon nanowires have been patterned with mean widths down to 4 nm using top-down lithography and dry etching. Performance-limiting scattering processes have been measured directly which provide new insight into the electronic conduction mechanisms within the nanowires. Results demonstrate a transition from 3-dimensional (3D) to 2D and then 1D as the nanowire mean widths are reduced from 12 to 4 nm. The importance of high quality surface passivation is demonstrated by a lack of significant donor deactivation, resulting in neutral impurity scattering ultimately limiting the electronic performance. The results indicate the important parameters requiring optimization when fabricating nanowires with atomic dimensions