| 1. |
- North, R. L., et al.
(författare)
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The state of Lake Simcoe (Ontario, Canada) : the effects of multiple stressors on phosphorus and oxygen dynamics
- 2013
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Ingår i: Inland Waters. - 2044-2041 .- 2044-205X. ; 3:1, s. 51-74
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Tidskriftsartikel (refereegranskat)abstract
- Lake Simcoe, the largest lake in southern Ontario outside of the Laurentian Great Lakes, is affected by numerous stressors including eutrophication resulting from total phosphorus (TP) loading, climate change, and invasions of exotic species. We synthesized the long-term responses of Lake Simcoe to these stressors by assessing trends in water quality and biological composition over multiple trophic levels. Evidence for climate change included increasing thermal stability of the lake and changes in subfossil diatom communities over time. Although the deep water dissolved oxygen (O-2) minimum has increased significantly since TP load reductions, it is still below estimated historical values and the Lake Simcoe Protection Plan end-of-summer target level of 7 mg O-2 L-1. Low deep water O-2 concentrations corresponded with a decline in coldwater fish abundance. Since 1980, some nutrient concentrations have decreased (spring TP) while others have increased (silica), but many show no obvious changes (ice-free TP, nitrate, ammonium). Increases in water clarity, combined with declines in chlorophyll a and phytoplankton biovolumes in Cook's Bay, were temporally consistent with declines in TP loading and the lake-wide establishment of dreissenid mussels as a major component of the Lake Simcoe ecosystem. Using an investigative tool, we identified 2 periods when abrupt shifts potentially occurred in multiple parameters: 1986 and 1995-1997. Additional ecosystem level changes such as declines in zooplankton, declines in offshore benthic invertebrate abundance, and increased nearshore invertebrate abundance likely reflect the effects of invasive species. The interaction of these multiple stressors have significantly altered the Lake Simcoe ecosystem.
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| 2. |
- Province, M. A., et al.
(författare)
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CYP2D6 Genotype and Adjuvant Tamoxifen : Meta-Analysis of Heterogeneous Study Populations
- 2014
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Ingår i: Clinical Pharmacology and Therapeutics. - New York, USA : Nature Publishing Group. - 0009-9236 .- 1532-6535. ; 95:2, s. 216-227
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Tidskriftsartikel (refereegranskat)abstract
- The International Tamoxifen Pharmacogenomics Consortium was established to address the controversy regarding cytochrome P450 2D6 (CYP2D6) status and clinical outcomes in tamoxifen therapy. We performed a meta-analysis on data from 4,973 tamoxifen-treated patients (12 globally distributed sites). Using strict eligibility requirements (postmenopausal women with estrogen receptor-positive breast cancer, receiving 20 mg/day tamoxifen for 5 years, criterion 1), CYP2D6 poor metabolizer status was associated with poorer invasive disease-free survival (IDFS: hazard ratio = 1.25; 95% confidence interval = 1.06, 1.47; P = 0.009). However, CYP2D6 status was not statistically significant when tamoxifen duration, menopausal status, and annual follow-up were not specified (criterion 2, n = 2,443; P = 0.25) or when no exclusions were applied (criterion 3, n = 4,935; P = 0.38). Although CYP2D6 is a strong predictor of IDFS using strict inclusion criteria, because the results are not robust to inclusion criteria (these were not defined a priori), prospective studies are necessary to fully establish the value of CYP2D6 genotyping in tamoxifen therapy.
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| 3. |
- Dahl, O. E., et al.
(författare)
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A critical appraisal of bleeding events reported in venous thromboembolism prevention trials of patients undergoing hip and knee arthroplasty
- 2010
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 8:9, s. 1966-1975
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Tidskriftsartikel (refereegranskat)abstract
- Summary Background: Anticoagulants are effective for the prevention of venous thromboembolism (VTE) but cause bleeding. Interpretation of the risks and benefits of new anticoagulant regimens for VTE prevention is complicated by a lack of standardized definitions and reporting of bleeding. We reviewed the reporting of bleeding in randomized controlled trials of new anticoagulants compared with standard doses of enoxaparin in hip and knee arthroplasty, and examined the possible impact of differences in the definition of major bleeding on interpretation of the trial results. Methods: Electronic searches identified 16 phase III trials published between 2001 and 2010 involving 41,265 patients comparing one of 5 new anticoagulants with a common comparator, enoxaparin. Results: Major bleeding rates in patients treated with enoxaparin ranged from 0.1% to 3.1% in hip arthroplasty trials and from 0.2% to 1.4% in knee arthroplasty trials. In studies that excluded surgical-site bleeding from the definition, major bleeding rates were about 10-fold lower than in those which included surgical-site bleeding. Within the individual trials, the choice of bleeding definition and the methods of assessment of bleeding influenced the conclusions regarding the risk of bleeding with new anticoagulant regimens relative to enoxaparin. Eight of the 16 studies demonstrated a >/=40% relative risk differences in major bleeding between treatment groups but the difference was statistically significant in only two of these trials. Conclusion: Randomized VTE prevention trials report markedly different rates of major bleeding despite similar patient populations and doses and durations of anticoagulant prophylaxis and were underpowered to detect modest differences in patient-important bleeding events. Standardization of bleeding definitions and reporting seems desirable.
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| 4. |
- Lidman, Jacob, 1985, et al.
(författare)
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An automated performance-aware approach to reliability transformations
- 2014
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Ingår i: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics). - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. - 9783319143248 ; 8805:Part 1, s. 523-534
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Konferensbidrag (refereegranskat)abstract
- Soft errors are expected to increase as feature sizes shrink and the number of cores increases. Redundant execution can be used to cope with such errors. This paper deals with the problem of automatically finding the number of redundant executions needed to achieve a preset reliability threshold. Our method uses geometric programming to calculate the minimal reliability for each instruction while still ensuring that the reliability of the program satisfies a given threshold. We use this to approximate an upper bound on the number of redundant instructions. Using this, we perform a limit study to find the implications of different redundant execution schemes. In particular we notice that the overhead of higher redundancy has serious implications to reliability. We therefore create a scheme where we only perform more executions if needed. Applying the results from our optimization improves reliability by up to 58.25%. We show that it is possible to achieve up to 8% better performance than Triple Modular Redundancy (TMR). We also show cases where our approach is insufficient.
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| 5. |
- Lidman, Jacob, 1985, et al.
(författare)
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ROSE::FTTransform - A source-to-source translation framework for exascale fault-tolerance research
- 2012
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Ingår i: IEEE/IFIP 42nd International Conference on Dependable Systems and Networks Workshops, DSN-W 2012; Boston, MA; United States; 25 June 2012 through 28 June 2012. - 9781467322645
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Konferensbidrag (refereegranskat)abstract
- Exascale computing systems will require sufficient resilience to tolerate numerous types of hardware faults while still assuring correct program execution. Such extreme-scale machines are expected to be dominated by processors driven at lower voltages (near the minimum 0.5 volts for current transistors). At these voltage levels, the rate of transient errors increases dramatically due to the sensitivity to transient and geographically localized voltage drops on parts of the processor chip. To achieve power efficiency, these processors are likely to be streamlined and minimal, and thus they cannot be expected to handle transient errors entirely in hardware. Here we present an open, compiler-based framework to automate the armoring of High Performance Computing (HPC) software to protect it from these types of transient processor errors. We develop an open infrastructure to support research work in this area, and we define tools that, in the future, may provide more complete automated and/or semi-automated solutions to support software resiliency on future exascale architectures. Results demonstrate that our approach is feasible, pragmatic in how it can be separated from the software development process, and reasonably efficient (0% to 30% overhead for the Jacobi iteration on common hardware; and 20%, 40%, 26%, and 2% overhead for a randomly selected subset of benchmarks from the Livermore Loops [1]).
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