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...

The scheduling of tasks within a parallel program onto the underlying available processors has been studied for some time. To date, solutions to this problem generally assume that communication only occurs at the start or end of each parallel task, i.e., the child task can only start its execution when all its parent tasks complete and have sent data to it. This is termed \non-preemptive task s...

Consider a two-class unobservable priority queue, with Poisson arrivals, generally distributed service, and strategic customers. Customers are charged fee when joining the premium class. We analyze maximum revenue achievable under non-preemptive (NP) preemptive-resume (PR) policies, show that provider is always better off implementing PR policy. Further, sometimes achieved only fraction of cust...

We consider a multi-source status update system, where each source generates packets according to Poisson process which are then served generally distributed service time. For this M/G/1/1 queueing model, we self-preemptive packet management policy and derive the moment generating functions (MGFs) of age information (AoI) peak AoI source. According policy, an arriving fresh preempts possible sa...

Preemptive scheduling is widespread in operating systems and in parallel processing on symmetric multiprocessors. However, in distributed systems it is practically unheard of. Scheduling in distributed systems is an important issue, and has performance impact on parallel processing, load balancing and metacomputing. Non-preemptive scheduling can perform well if the task lengths and processor sp...

in a randomized, double blind study , we compared post operative pain and analgesic requirement in patients undergoing cesarean section with two types of general anesthesia: standardized general anesthesia (control group=26 cases) and preemptive low-dose ketamine (0.2 mg/kg) administered prior to anesthesia induction (keratmine group=27 cases). postoperative analgesia was provided for both grou...

We are given a set of jobs, each one specified by its release date, its deadline and its processing volume (work), and a single (or a set of) speed-scalable processor(s). We adopt the standard model in speed-scaling in which if a processor runs at speed s then the energy consumption is s units of energy per time unit, where α > 1 is a small constant. Our goal is to find a schedule respecting th...