8,769,351 research outputs found
A Comparison of some recent Task-based Parallel Programming Models
The need for parallel programming models that are simple to use and at the same time efficient for current ant future parallel platforms has led to recent attention to task-based models such as Cilk++, Intel TBB and the task concept in OpenMP version 3.0. The choice of model and implementation can have a major impact on the final performance and in order to understand some of the trade-offs we have made a quantitative study comparing four implementations of OpenMP (gcc, Intel icc, Sun studio and the research compiler Mercurium/nanos mcc), Cilk++ and Wool, a high-performance task-based library developed at SICS.
Abstract. We use microbenchmarks to characterize costs for task-creation and stealing and the Barcelona OpenMP Tasks Suite for characterizing application performance. By far Wool and Cilk++ have the lowest overhead in both spawning and stealing tasks. This is reflected in application performance when many tasks with small granularity are spawned where Cilk++ and, in particular, has the highest performance. For coarse granularity applications, the OpenMP implementations have quite similar performance as the more light-weight Cilk++ and Wool except for one application where mcc is superior thanks to a superior task scheduler.
Abstract. The OpenMP implemenations are generally not yet ready for use when the task granularity becomes very small. There is no inherent reason for this, so we expect future implementations of OpenMP to focus on this issue
Comparison of estimates of left ventricular ejection fraction using gated blood imagining
Serial measurement of left ventricular ejection fraction (L VEF) using GBP imaging is an established technique for monitoring L VEF in patients undergoing chemotherapy with cardio-toxic medication and in patients after heart transplants. Oncologists at our institution decide that cardio-toxic chemotherapy should be discontinued if the L VEF decreases by 10%, or if a value of 50% is reached. In patients with baseline L VEFs of less than 50% but greater than 30% therapy will be discontinued if the L VEF decreases by 10% or if a value of less than 30% is reached. This is in accordance with the guidelines set out by the Oxford Textbook ofOncology.3 In patients who have had heart transplants, GBP studies are used to monitor L VEF. If there is a decrease in L VEF, cardiologists may decide to start glucocoricosteroids for rejection. It is therefore imperative that serial studies on an individual patient are comparable. There are two software systems used in our nuclear medicine department; the Siemens system and the Hermes system. In a pilot study we found large differences between the L VEFs calculated by the two systems. This is consistent with the consensus in the literature that different software programs for processing GBP studies cannot be used interchangeably
Comparison of Career Decision Difficulties Between Nursing Freshmen and Interns
Career selection is one of the most important decisions an individual makes in his life. High career expectation could result in career decision difficulties. This study aimed to compare and analyze the career decision difficulties between nursing freshmen and interns. This cross-sectional study involved 110 and 66 nursing freshmen and interns respectively (n=176) in two private nursing colleges. Career decision difficulties questionnaire was used in data collection. Descriptive statistic and independent sample t test were used in data analysis (α<.05). Results showed that most respondents experienced moderate difficulties in both groups. Overall, there was no significant difference of career decision difficulty found between groups (p=.057), but indecisiveness, dysfunctional myths, lack of knowledge about the process of career decision making, lack of information, lack of information about occupations, lack of information about ways of obtaining additional information, and internal conflicts were significantly different between groups (all p<α). Career decision difficulties occur similarly both in nursing freshmen and interns
The Comparison of Creatinine and Cystatin C Value in Preeclampsia Severity and Neonatal Outcome
Objectives: to compare the levels of creatinine and cystatin C with the severity of preeclampsia, and assess neonatal outcomes.Materials and Methods: Creatinine, cystatin C, and neonatal outcomes were assesed in 17 normotensive samples, 17 samples of mild preeclampsia and 17 samples of severe preeclampsia. Analysis of data with statistical tests of ANOVA and t test differences between 2 proportions.Results: The mean levels of creatinine in the normotensive group, mild preeclampsia, severe preeclampsia are 0.56 mg/dL, 0.67 mg/ dL, and 0.75 mg/dL, p=0.138; While on cystatin C are 0.82 mg/L, 1.03 mg/L and 1.32 mg/L, p=0.000. The adverse neonatal out-come wasn't found in the normotensive group. In mild pre-eclampsia obtained 1 preterm birth and 1 intrauterine fetal death (IUFD), whereas in severe preeclampsia obtained 3 babies born preterm, 1 IUFD, and 1 intrauterine growth restriction (IUGR).Conclusion: levels of cystatin C was increased significantly in line with increased severity of preeclampsia, whereas creatinine was not increased significantly. Cystatin C is better than crea-tinine as a marker of renal dysfunction in preeclampsia patients. There was an increase in adverse neonatal outcomes in the group of preeclampsia
The Comparison of Gabapentin and Amitriptilin Effectivity as Pain Therapy in Herniated Nucleus Pulposus
Herniated nucleus pulposus (HNP) is one of peripheral neuropathic pain. Although concensus guidelines for the treatment of neuropathic pain are based on the results of the RCT studies, there are still gaps in the literatures. This study aimed to compare the effectiveness and quality of life of gabapentin and amitriptyline for the treatment of pain in HNP. The method used a quasi experimental with consequtive sampling. This study included 30 patients in the gabapentin group and 26 patients in the amitriptyline group, and each group was evaluated for 1 month. Effectiveness was assessed using Visual Analogue Scale (VAS) every 2 weeks then analized by independent and paired sample t test. The results showed that the use of gabapentin and amitriptilin in 4 weeks showed the decrease of pain score measured by visual analog scale 3.70 ± 0.349 and 3.500 ± 0.34 although there was no statistical difference (p value = 0.704). To sum up, effectiveness of gabapentin and amitriptyline in the treatment of neuropathic pain did not have statistical difference
Comparison of Risk of Recrudescent Fever in Children With Kawasaki Disease Treated With Intravenous Immunoglobulin and Low-Dose vs High-Dose Aspirin
Importance:
Timely initiation of intravenous immunoglobulin plus aspirin is necessary for decreasing the risk of recrudescent fever and coronary artery abnormalities in children with Kawasaki disease (KD). The optimal dose of aspirin, however, remains unclear.
Objective:
To evaluate whether initial treatment with low-dose compared with high-dose aspirin in children with KD is associated with an increase in fever recrudescence.
Design, Setting, and Participants:
A retrospective cohort study of 260 children with KD at Riley Hospital for Children, Indianapolis, Indiana, between January 1, 2007, and December 31, 2018, was conducted. Children aged 0 to 18 years with a first episode of KD, identified by International Classification of Diseases, Ninth Revision and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnosis codes treated within 10 days of symptom onset with high-dose intravenous immunoglobulin plus aspirin were eligible. Patients who received an alternative diagnosis, experienced a second episode of KD, did not receive intravenous immunoglobulin plus aspirin for initial treatment, were not treated within 10 days of symptoms, or had incomplete records were excluded.
Exposures:
High-dose (≥10 mg/kg/d) or low-dose (<10 mg/kg/d) aspirin therapy.
Main Outcomes and Measures:
The primary outcome was recrudescent fever necessitating retreatment of KD. The secondary outcomes were coronary artery abnormalities and hospital length of stay.
Results:
Among the 260 patients included, the median (interquartile range) age was 2.5 (1.6-4.3) years, 103 (39.6%) were girls, 166 (63.8%) were non-Hispanic white, 57 (21.9%) were African American, 22 (8.5%) were Asian, 11 (4.2%) were Hispanic, and 4 (1.5%) were of unknown race/ethnicity. One hundred-forty-two patients (54.6%) were treated with low-dose aspirin. There was no association between recrudescent fever and aspirin dose, with 39 children (27.5%) having recrudescent fever in the low-dose group compared with 26 children (22.0%) in the high-dose group (odds ratio [OR], 1.34; 95% CI, 0.76-2.37; P = .31), with similar results after adjusting for potential confounding variables (OR, 1.63; 95% CI, 0.89-2.97; P = .11). In a subset analysis of 167 children with complete KD, however, there was nearly a 2-fold difference in the odds of recrudescent fever with low-dose aspirin (OR, 1.87; 95% CI, 0.82-4.23; P = .14), although this difference did not reach statistical significance. In addition, no association was identified between treatment group and coronary artery abnormalities (low-dose, 7.4% vs high-dose, 9.4%; OR, 0.86; 95% CI, 0.48-1.55; P = .62) or median (interquartile range) length of stay (3 [3-5] days for both groups; P = .27).
Conclusions and Relevance:
In this study, low-dose aspirin for the initial treatment of children with KD was not associated with fever recrudescence or coronary artery abnormalities. Given the potential benefits, further study of low-dose aspirin to detect potentially clinically relevant outcome differences is warranted to inform treatment decisions and guideline development
Model comparison with Sharpe ratios
We show how to conduct asymptotically valid tests of model comparison when the extent of model mispricing is gauged by the squared Sharpe ratio improvement measure. This is equivalent to ranking models on their maximum Sharpe ratios, effectively extending the Gibbons, Ross, and Shanken (1989) test to accommodate the comparison of nonnested models. Mimicking portfolios can be substituted for any nontraded model factors, and estimation error in the portfolio weights is taken into account in the statistical inference. A variant of the Fama and French (2018) 6-factor model, with a monthly updated version of the usual value spread, emerges as the dominant model
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