Advance reservation of Grid resources can play a key role in enabling Grid middleware to deliver on-demand resource provision with significantly improved Quality-of-Service (QoS). However, in the Grid, advance reservation has been largely ignored due to the dynamic Grid behavior, underutilization concerns, multi-constrained applications, and lack of support for agreement enforcement. These issues force the Grid middleware to make resource allocations at runtime with reduced QoS. To remedy these, we introduce a new, 3-layered negotiation protocol for advance reservation of the Grid resources. We model resource allocation as an on-line strip packing problem and introduce a new mechanism that optimizes resource utilization and QoS constraints while generating the contention-free solutions. The mechanism supports open reservations to deal with the dynamic Grid and provides a practical solution for agreement enforcement. We have implemented a prototype and performed experiments to demonstrate the effectiveness of our approach.
In this paper we present an extension to devise and implement advance reservation as part of the scheduling and resource management services of the ASKALON Grid application development and runtime environment. The scheduling service has been enhanced to offer a list of resources that can execute a specific task and to negotiate with the resource manager about resources capable of processing tasks in the shortest possible time. We introduce progressive reservation approach which tries to allocate resources based on a fair-share principle. Experiments are shown that demonstrate the effectiveness of our approach, and that reflect different QoS parameters including performance, predictability, resource usage and resource fairness. IntroductionScheduling and resource management play a key role for effective execution of applications on the Grid. A scheduler is used to make a plan for the execution, determining which tasks should be executed on which resources and in which order. Resource management is responsible for services such as registration and provision of resources. The scheduler optimizes a goal function, usually execution time or economic cost. Created in this way schedules are subsequently executed.Highly dynamic and unreliable Grid environments make any assumptions concerning resource availability and execution time extremely difficult. Therefore, creation of a reliable schedule and proper reservation of resources constitute one of the largest challenges in Grid computing. Grid environments cannot usually guarantee that execution requests will be fulfilled within expected time intervals. Moreover, requests coming from other users can always disrupt already taken scheduling decisions. Time-critical applications, which are an important class of Grid applications, cannot be effectively executed without any guarantee for the expected execution time. Advance reservation of resources provides a possible solution to this problem. A user can re- * This work is partially funded by the European Union through the IST-2002-511385 KWf-Grid and IST-034601 Edutain@Grid projects. serve resources, in order to be sure that within a requested period of time resources will be available.This paper investigates the impact of resource reservations on different aspects of application execution, represented by different criteria comprising execution time, predictability, resource usage and fairness. Predictability can be considered as the most important criterion, because it has a substantial impact on the execution of time-constrained applications. We have chosen scientific grid workflow applications as the class of computational applications to validate our approach. Workflow applications consist of execution tasks, data transfer tasks, and dependencies between them.The rest of the paper is organized as follows. In the next section we describe briefly the related work on advance reservations for the Grid. Later, we present the architecture of our Grid environment, focusing on scheduling and resource management. Section 5...
Background: There are many studies on stroke, its associated conditions and their effect on stroke patients outcome, but a few studies on dyselectrolytaemia in stroke patients has been done in our country, even outside. Method: a total number of 100 randomly selected, clinically and CT proven acute stroke patients were studied at medicine units of Dhaka Medical College Hospital. Association of electrolytes imbalance among acute stroke patient were identified and correlated. Result: Out of 100 patients 29% were in between 51-60 years age group & 72% were male and 28% were female patients. Majority 53% patients had Ischaemic stroke, 45% Intracerebral haemorrhage (ICH) and only 2% had Subarachnoid haemorrhage (SAH). 53% of total acute stroke patient had dyselectrolytaemia. Among 100 acute stroke patients 62.22% of haemorrhagic stroke (p<0.05) & 43.39% of ischaemic stroke (p>0.05) patients had dyselectrolytaemia. Total 36% of all stroke patients had serum sodium imbalance & 31% had serum potassium imbalance. In haemorrhagic stroke & ischaemic stroke patients, hyponatraemia (17% & 13%), hypernatraemia (1% & 3%), hypokalaemia (19% & 11%), hyperkalaemia (0% & 1%), hypochloraemia (9% & 6%) respectively with found. Conclusion: In haemorrhagic stroke, the incidence of dyselectrolytaemia was more than ischaemic stroke and which were mostly hyponatraemia and hypokalaemia. DOI: http://dx.doi.org/10.3329/bjmed.v22i2.13586 Bangladesh J Medicine 2011; 22: 30-34
Introduction: Appropriate lipid-lowering therapies are essential for the primary and secondary prevention of atherosclerotic cardiovascular disease (ASCVD). The aim of this study is to identify discrepancies between cholesterol management guidelines and current practice in an underserved population, with a focus on statin treatment. Methods: We reviewed the records of 1,042 consecutive patients seen between August 2018 and August 2019 in an outpatient academic primary care clinic. Eligibility for statin and other lipid-lowering therapies was determined based on the 2018 American Heart Association and American College of Cardiology (AHA/ACC) guideline on the management of blood cholesterol. Results: Among 464 statin-eligible patients, age was 61.1 +/- 10.4 years and 53.9% were female. Most patients were Black (47.2%), followed by Hispanic (45.7%), and White (5.0%). Overall, 82.1% of patients were prescribed a statin. Statin-eligible patients who qualified based only on a 10-year ASCVD risk > 7.5% were less likely to be prescribed a statin (32.8%, p<0.001). After adjustment for gender and health insurance status, appropriate statin treatment was independently associated with age > 55 years (OR = 4.59 [95% CI 1.09 - 16.66], p = 0.026), hypertension (OR = 2.38 [95% CI 1.29 - 4.38], p = 0.005) and chronic kidney disease (OR = 3.95 [95% CI 1.42 - 14.30], p = 0.017). Factors independently associated with statin undertreatment were Black race (OR = 0.42 [95% CI 0.23 - 0.77], p = 0.005), and statin-eligibility based solely on an elevated 10-year ASCVD risk (OR = 0.14 [95% CI 0.07 - 0.25], p < 0.001). Hispanic patients were more likely to be on appropriate statin therapy when compared to Black patients (86.8% vs 77.2%). Conclusion: Statin underprescription is seen in approximately one out of five eligible patients, and is independently associated with Black race, younger age, fewer comorbidities, and eligibility via 10-year ASCVD risk only. Hispanic patients are more likely to be on appropriate statin therapy compared to Black patients.
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