INTRODUCTION E-cigarettes have increased in popularity and given rise to a new type of sales outlet-the vape shop. Expanding on work examining vape shop employee e-cigarette and tobacco attitudes and behaviors1, this study examined key messages that vape shop employees communicate to customers. METHODS Using informal interviews, observations, and a cross-sectional survey, we examined vape sho...

The minimization of makespan in open shop with time lags has been to be shown NP-hard the strong sense even for case two machines and unit-time operations. total completion time, however, remained that though it weighted or jobs release dates. This note shows operations is which answers long standing question.