Preemptive kidney transplantation, as a treatment modality for end-stage renal disease, offers higher clinical advantages compared to maintenance dialysis. Nevertheless, preemptive transplantations raises ethical concerns, particularly regarding medical resource allocation. From an ethical perspective, health care decisions should be focused on the patient's needs. Nevertheless, a fair distribu...

Edge-finding bounding techniques are particular constraint propagation techniques which reason about the order in which several activities can execute on a given resource. The aim of the following paper is to provide a rather comprehensive (although necessarily incomplete) review of existing edge-finding algorithms. The simplest case of non-preemptive disjunctive scheduling is reviewed first, f...

We investigate the problem of on-line scheduling two-machine open shops with the objective of minimizing the makespan. Jobs arrive independently over time, and the existence of a job is not known until its arrival. In the clairvoyant on-line model, the processing requirement of every job becomes fully known at the arrival of the job, while in the non-clairvoyant on-line model, this processing r...

Cytomegalovirus (CMV) is a major cause of morbidity and mortality following solid organ transplantation (SOT). Two strategies, prophylactic, and preemptive have emerged for the prevention of CMV infection and disease after SOT. This retrospective chart review of two liver transplant cohorts: prophylactic and preemptive, compares the clinical impact of transitioning from prophylactic to preempti...

In pest risk assessment it is frequently necessary to make time-critical decisions regarding management of expanding pest populations. When an invasive pest outbreak is expanding rapidly, preemptive quarantine of areas that are under imminent threat of infestation is one of only a few available management tools that can be implemented quickly to help control the expansion. The preemptive quaran...

BACKGROUND Empirical antifungal therapy is the standard of care for neutropenic patients with hematological malignancies who remain febrile despite broad-spectrum antibacterial treatment. Recent diagnostic improvements may ensure the early diagnosis of potentially invasive fungal disease. Reserving antifungals for this stage may achieve similar survival rates and reduce treatment toxicity and c...

We consider a scheduling problem, which we call the Scheduling and Wavelength Assignment (SWA) problem, arising in optical networks that are based on the Wavelength Division Multiplexing (WDM) technology. We prove that the SWA problem is NP-hard for both the preemptive and the non-preemptive cases. Furthermore, we propose two eÆcient approximation algorithms. The rst is for the preemptive case ...

BACKGROUND Ethanol lock therapy (ELT) with systemic antimicrobial therapy is a promising therapy for catheter-related infection (CRI). The impact of ELT timing on treatment efficacy and costs is unknown. PROCEDURES A prospective study was conducted in the Hematology/Oncology Unit at the Children's Hospital of Michigan. Patients with suspected CRI were randomized to Preemptive ELT arm or Rescu...

Whether preemptive therapy or universal prophylaxis with ganciclovir is the optimal approach against cytomegalovirus (CMV) remains unresolved. Controversy abounds with respect to the efficacy of preemptive therapy, the reliability of preemptive therapy tools, the logistical difficulties in conducting surveillance monitoring for CMV, the cost of prophylaxis, the effect of prophylaxis on indirect...

Kidney transplantation is the most preferred treatment for end-stage renal disease because it improves not only the patient's survival compared with dialysis, but also the quality of life. Preemptive transplantation is transplantation performed prior to the initiation of renal dialysis. Recent observational studies have shown increased patient and graft survival with preemptive transplantation,...