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Abstract. In general computing systems, a job (process/task) may suspend itself whilst it is waiting for some activity to complete, e.g., an accelerator to return data. In real-time systems, such self-suspension can cause substantial performance/schedulability degradation. This observation, first made in 1988, has led to the investigation of the impact of self-suspension on timing predictability, and many relevant results have been published since. Unfortunately, as it has recently come to light, a number of the existing results are flawed. To provide a correct platform on which future research can be built, this paper reviews the state of the art in the design and analysis of scheduling algorithms and schedulability tests for self-suspending tasks in real-time systems. We provide (1) a systematic description of how self-suspending tasks can be handled in both soft and hard real-time systems; (2) an explanation of the existing misconceptions and their potential remedies; (3) an assessment of the influence of such flawed analyses on partitioned multiprocessor fixed-priority scheduling when tasks synchronize access to shared resources; and (4) a discussion of the computational complexity of analyses for different self-suspension task models.

The combined impact of the LWA program Levy and the programs and services funded by the Levy reduced the burden of alcohol-attributable injury to the NT in the short term and may have contributed to a reduction in chronic illness in the longer term. The results of this study present a strong argument for the effectiveness of combining alcohol taxes with comprehensive programs and services designed to reduce the harm from alcohol, and underline the need to distinguish between the acute and chronic effects of alcohol in population level studies.

In most real-time systems, tasks use remote operations that are executed upon dedicated processors. External operations introduce selfsuspension delays in the behavior of tasks. This paper presents several negative results concerning scheduling independent hard real-time tasks with self-suspensions. Our main objective is to show that well-known scheduling policies such as fixed-priority or Earliest Deadline First are not efficient to schedule such task systems. We prove the scheduling problem to be NP-hard in the strong sense, even for synchronous task systems with implicit deadlines. We also show that scheduling anomalies can occur at run-time: reducing the execution requirement or the suspension delay of a task can lead the task system to be infeasible under EDF. Lastly, we present negative results on the worst-case performances of well-known scheduling algorithms (EDF, RM, DM, LLF, SRPTF) to maximize tasks completed by their deadlines. Complexity of the Run-Time Scheduling ProblemWe next show that the feasibility problem of scheduling synchronously released tasks, with implicit deadlines having at most one selfsuspension each, is NP-hard in the strong sense. We also prove that scheduling anomalies can occur under EDF.

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Past reviews have concluded that there is no association between alcohol use and prostate cancer incidence. We performed a meta-analysis of existing epidemiological studies finding, in contrast, evidence to suggest that prostate incidence is positively linearly associated with heavier alcohol use. This finding was largely due to the contribution of population case-control studies and those measuring men recruited before age 60. No relationship between alcohol consumption and prostate cancer was found for cohort and hospital case-control studies. Analyses of design effects modestly suggests that population case-control studies were probably better suited to identify potential alcohol-prostate cancer relationships due to the close temporal proximity of the measurement of level of alcohol consumption to diagnosis. Future efforts should be made to exclude all ill subjects from control groups/baseline samples in addition to accounting for changes in consumption with advancing age and the onset of illness. The alcohol-prostate cancer association remained significant despite controlling for the degree to which studies endeavored to eliminate false negatives from their control groups.

Reductions in overall ALD mortality observed are likely the result of advances in disease management. Significant increase in hospital admissions suggests an increase in the prevalence of ALD among the Australian population. Dramatic increases in hospital admissions for alcoholic cirrhosis in 2002/2003 for the 20-29 years population may have been due to an increase in screening of alcohol-related harms in primary care settings.

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