| 1. |
- Nelson, David W., et al.
(författare)
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Multivariate outcome prediction in traumatic brain injury with focus on laboratory values
- 2012
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 29:17, s. 2613-2624
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Tidskriftsartikel (refereegranskat)abstract
- Traumatic brain injury (TBI) is a major cause of morbidity and mortality. Identifying factors relevant to outcome can provide a better understanding of TBI pathophysiology, in addition to aiding prognostication. Many common laboratory variables have been related to outcome but may not be independent predictors in a multivariate setting. In this study, 757 patients were identified in the Karolinska TBI database who had retrievable early laboratory variables. These were analyzed towards a dichotomized Glasgow Outcome Scale (GOS) with logistic regression and relevance vector machines, a non-linear machine learning method, univariately and controlled for the known important predictors in TBI outcome: age, Glasgow Coma Score (GCS), pupil response, and computed tomography (CT) score. Accuracy was assessed with Nagelkerke's pseudo R2. Of the 18 investigated laboratory variables, 15 were found significant (p<0.05) towards outcome in univariate analyses. In contrast, when adjusting for other predictors, few remained significant. Creatinine was found an independent predictor of TBI outcome. Glucose, albumin, and osmolarity levels were also identified as predictors, depending on analysis method. A worse outcome related to increasing osmolarity may warrant further study. Importantly, hemoglobin was not found significant when adjusted for post-resuscitation GCS as opposed to an admission GCS, and timing of GCS can thus have a major impact on conclusions. In total, laboratory variables added an additional 1.3-4.4% to pseudo R2.
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| 2. |
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| 3. |
- Perner, Anders, et al.
(författare)
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Hydroxyethyl Starch 130/0.4 versus Ringer's Acetate in Severe Sepsis
- 2012
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Ingår i: New England Journal of Medicine. - 0028-4793 .- 1533-4406. ; 367:2, s. 124-134
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND Hydroxyethyl starch (HES) 130/0.4 is widely used for fluid resuscitation in intensive care units (ICUs), but its safety and efficacy have not been established in patients with severe sepsis. METHODS In this multicenter, parallel-group, blinded trial, we randomly assigned patients with severe sepsis to fluid resuscitation in the ICU with either 6% HES 130/0.4 or Ringer's acetate at a dose of up to 33 ml per kilogram of ideal body weight per day. The primary outcome measure was either death or end-stage kidney failure (dependence on dialysis) at 90 days after randomization. RESULTS Of the 804 patients who underwent randomization, 798 were included in the modified intention-to-treat population. The two intervention groups had similar baseline characteristics. At 90 days after randomization, 201 of 398 patients (51%) assigned to HES 130/0.4 had died, as compared with 172 of 400 patients (43%) assigned to Ringer's acetate (relative risk, 1.17; 95% confidence interval [CI], 1.01 to 1.36; P=0.03); 1 patient in each group had end-stage kidney failure. In the 90-day period, 87 patients (22%) assigned to HES 130/0.4 were treated with renal-replacement therapy versus 65 patients (16%) assigned to Ringer's acetate (relative risk, 1.35; 95% CI, 1.01 to 1.80; P=0.04), and 38 patients (10%) and 25 patients (6%), respectively, had severe bleeding (relative risk, 1.52; 95% CI, 0.94 to 2.48; P=0.09). The results were supported by multivariate analyses, with adjustment for known risk factors for death or acute kidney injury at baseline. CONCLUSIONS Patients with severe sepsis assigned to fluid resuscitation with HES 130/0.4 had an increased risk of death at day 90 and were more likely to require renal-replacement therapy, as compared with those receiving Ringer's acetate.
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| 4. |
- Steinert, Rebecca
(författare)
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Probabilistic Fault Management in Networked Systems
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Technical advances in network communication systems (e.g. radio access networks) combined with evolving concepts based on virtualization (e.g. clouds), require new management algorithms in order to handle the increasing complexity in the network behavior and variability in the network environment. Current network management operations are primarily centralized and deterministic, and are carried out via automated scripts and manual interventions, which work for mid-sized and fairly static networks. The next generation of communication networks and systems will be of significantly larger size and complexity, and will require scalable and autonomous management algorithms in order to meet operational requirements on reliability, failure resilience, and resource-efficiency.A promising approach to address these challenges includes the development of probabilistic management algorithms, following three main design goals. The first goal relates to all aspects of scalability, ranging from efficient usage of network resources to computational efficiency. The second goal relates to adaptability in maintaining the models up-to-date for the purpose of accurately reflecting the network state. The third goal relates to reliability in the algorithm performance in the sense of improved performance predictability and simplified algorithm control.This thesis is about probabilistic approaches to fault management that follow the concepts of probabilistic network management (PNM). An overview of existing network management algorithms and methods in relation to PNM is provided. The concepts of PNM and the implications of employing PNM-algorithms are presented and discussed. Moreover, some of the practical differences of using a probabilistic fault detection algorithm compared to a deterministic method are investigated. Further, six probabilistic fault management algorithms that implement different aspects of PNM are presented.The algorithms are highly decentralized, adaptive and autonomous, and cover several problem areas, such as probabilistic fault detection and controllable detection performance; distributed and decentralized change detection in modeled link metrics; root-cause analysis in virtual overlays; event-correlation and pattern mining in data logs; and, probabilistic failure diagnosis. The probabilistic models (for a large part based on Bayesian parameter estimation) are memory-efficient and can be used and re-used for multiple purposes, such as performance monitoring, detection, and self-adjustment of the algorithm behavior.
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| 5. |
- Alhadad, Alaa, et al.
(författare)
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Iliocaval vein stenting: Long term survey of postthrombotic symptoms and working capacity.
- 2011
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Ingår i: Journal of Thrombosis and Thrombolysis. - : Springer Science and Business Media LLC. - 1573-742X .- 0929-5305. ; 31, s. 211-216
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the long term effect on lower extremity function and working capacity after stenting of iliocaval vein segments for acute deep venous thrombosis (DVT) or chronic venous occlusive disease. During a 14 year period from November 1994 to October 2008, 114 patients with median age 36 (interquartile range [IQR], 27-48) years, 72 (63%) women, 72 (63%) with hypercoagulable disorders, with acute DVT (n = 44, 39%), or chronic occlusions (n = 70, 61%) in the iliocaval vein segment were treated with venous stent placement after catheter-directed thrombolysis, angioplasty or recanalization. The long term impact on lower extremity function and working capacity was evaluated through retrospective evaluation of a prospectively registered database in combination with a questionnaire sent to all 108 surviving patients. The questionnaire was returned by 91/108(84%) patients, 37 (86%) with acute DVT, and 54(83%) with chronic venous occlusions. After a median follow-up of 6.2 (IQR 3.8-10.5) years, 38 (42%) patients were without anticoagulation therapy. Among patients with acute DVT 29 (78%) reported no lower extremity pain, 31 (84%) reported no ulcerations, and 26 (70%) were without lower extremity swelling, and 33(89%) without pelvic or genital pain. In summary, 22 (59%) were free from any symptomatic postthrombotic symptoms (PTS). Among patients with chronic occlusions, corresponding figures were 22 (41%), 45 (80%), 13 (24%), 39 (72%), and 7 (13%). Among patients treated for acute DVT 27 (73%) were working full- or part time, and 2 (5%) were above retirement age. Corresponding figures among patients treated for chronic venous occlusions were 31 (57%), and 10 (19%). Stenting of iliocaval vein segments with or without catheter-directed thrombolysis is a promising treatment of both acute thrombosis and chronic iliocaval vein occlusion that requires further study in comparison to non-interventional treatment concerning long time effects on postthrombotic symptoms and working capacity.
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| 6. |
- Bohlin, Markus, et al.
(författare)
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Statistical Anomaly Detection for Train Fleets
- 2012. - 9
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Ingår i: Proceedings of the National Conference on Artificial Intelligence, vol. 3, 2012. - Toronto, Canada. - 9781577355687 ; , s. 2217-2223
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Konferensbidrag (refereegranskat)abstract
- We have developed a method for statistical anomaly detection which has been deployed in a tool for condition monitoring of train fleets. The tool is currently used by several railway operators over the world to inspect and visualize the occurrence of "event messages" generated on the trains. The anomaly detection component helps the operators to quickly find significant deviations from normal behavior and to detect early indications for possible problems. The savings in maintenance costs comes mainly from avoiding costly breakdowns, and have been estimated to several million Euros per year for the tool. In the long run, it is expected that maintenance costs can be reduced with between 5 and 10 % by using the tool.
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| 7. |
- Bohlin, Markus, et al.
(författare)
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The opportunistic replacement and inspection problem for components with a stochastic life time
- 2011. - 6
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The problem of finding efficient maintenance and inspection schemes in the case of components with a stochastic life time is studied and a mixed integer programming solution is proposed. The problem is compared with the two simpler problems of which the studied problem is a generalisation: The opportunistic replacement problem, assuming components with a deterministic life time and The opportunistic replacement problem for components with a stochastic life time, for maintenance schemes without inspections.
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| 8. |
- Borgquist, Rasmus, et al.
(författare)
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The diagnostic performance of imaging methods in ARVC using the 2010 Task Force criteria.
- 2014
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Ingår i: European heart journal cardiovascular Imaging. - : Oxford University Press (OUP). - 2047-2412 .- 2047-2404. ; 15:11, s. 1219-1225
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluates the agreement between echocardiographic and cardiac magnetic resonance (CMR) imaging data, and the impact a discrepancy between the two may have on the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVC).
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| 9. |
- Ekman, Jan, et al.
(författare)
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Condition based maintenance of trains doors
- 2011. - 7
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- As part of the project DUST financed by Vinnova, we have investigated whether event data generated on trains can be used for finding evidence of wear on train doors. We have compared the event data and maintenance reports relating to doors of Regina trains. Although some interesting relations were found, the overall result is that the information in event data about wear of doors is very limited.
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| 10. |
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