INTRODUCTION Preemption is a legislative or judicial arrangement in which a higher level of government precludes lower levels of government from exercising authority over a topic. In the area of smoke-free policy, preemption typically takes the form of a state law that prevents communities from adopting local smoking restrictions. BACKGROUND A broad consensus exists among tobacco control prac...

Abstract This study was an attempt to investigate the effect of collaborative form-focused activities on grammar learning of elementary EFL learners. To this end, 58 adult male Iranian EFL learners at elementary level of proficiency in three classes of language institutes were chosen. They formed the three groups of the study. The grammar section of Cambridge Michigan Placement test was used to...

Abstract This study was an attempt to investigate the effect of collaborative form-focused activities on grammar learning of elementary EFL learners. To this end, 58 adult male Iranian EFL learners at elementary level of proficiency in three classes of language institutes were chosen. They formed the three groups of the study. The grammar section of Cambridge Michigan Placement test was used to...

BACKGROUND The efficacy of preemptive therapy against cytomegalovirus (CMV) infection remains unknown in treatment-naïve patients with advanced HIV-1 infection in the HAART era. METHODS The subjects of this single-center observation study were 126 treatment-naïve HIV-1 infected patients with positive CMV viremia between January 1, 2000 and December 31, 2006. Inclusion criteria were age more t...

Preemptive transplants are advisable in advanced stages of kidney disease. The clinical advantages of preemptive transplantation over dialysis are evident. Nevertheless, preemptive transplantations raise ethical concerns, particularly regarding the allocation of medical resources. The present article proposes some criteria for organ allocation policies regarding preemptive transplantations: cri...

OBJECTIVES Preemptive renal transplant has been associated with better survival of both the allograft and the recipient than has conventional renal transplant. It remains unclear, however, whether preemptive transplant is optimal for renal replacement therapy. We describe our experience with preemptive renal transplant. MATERIALS AND METHODS We retrospectively analyzed 32 preemptive and 132 n...

We study graph multicoloring problems, motivated by the scheduling of dependent jobs on multiple machines. In multicoloring problems, vertices have lengths which determine the number of colors they must receive, and the desired coloring can be either contiguous (non-preemptive schedule) or arbitrary (preemptive schedule). We consider both the sum-of-completion times measure, or the sum of the l...