8 research outputs found
Evaluating deep learning architecture and data assimilation for improving water temperature forecasts at unmonitored locations
Deep learning (DL) models are increasingly used to forecast water quality variables for use in decision making. Ingesting recent observations of the forecasted variable has been shown to greatly increase model performance at monitored locations; however, observations are not collected at all locations, and methods are not yet well developed for DL models for optimally ingesting recent observations from other sites to inform focal sites. In this paper, we evaluate two different DL model structures, a long short-term memory neural network (LSTM) and a recurrent graph convolutional neural network (RGCN), both with and without data assimilation for forecasting daily maximum stream temperature 7 days into the future at monitored and unmonitored locations in a 70-segment stream network. All our DL models performed well when forecasting stream temperature as the root mean squared error (RMSE) across all models ranged from 2.03 to 2.11°C for 1-day lead times in the validation period, with substantially better performance at gaged locations (RMSE = 1.45–1.52°C) compared to ungaged locations (RMSE = 3.18–3.27°C). Forecast uncertainty characterization was near-perfect for gaged locations but all DL models were overconfident (i.e., uncertainty bounds too narrow) for ungaged locations. Our results show that the RGCN with data assimilation performed best for ungaged locations and especially at higher temperatures (>18°C) which is important for management decisions in our study location. This indicates that the networked model structure and data assimilation techniques may help borrow information from nearby monitored sites to improve forecasts at unmonitored locations. Results from this study can help guide DL modeling decisions when forecasting other important environmental variables
The Canadian contribution to the otolaryngology literature: a five year bibliometric analysis
Objectives:
To assess the 2008–2012 Canadian contribution to the Otolaryngology literature.
Methods:
All articles published from January 2008 - December 2012 in 5 Otolaryngology journals were reviewed. Nationality, number of authors, and study type were extracted. The output, number of authors, and study type of Canadian papers were compared to International papers using Mantel-Haenszel Common Odds Ratio Estimate, Pearson’s Chi-Squared or Fishers exact tests.
Results:
4519 papers were analyzed. There was a statistically significant decrease in Canadian authored papers from 12.8% in 2008–9 to 10.2% in 2011–12 (Fishers exact, p = .01). Multi-authorship increased in Canadian papers (χ2, p = .01). The types of studies published by Canadian Otolaryngologists did not change over the study period.
Conclusions:
Canadian authored papers in a sample of Otolaryngology journals decreased from 2008 to 2012. The increase in multiauthorship, whilst indicating increasing collaboration, suggests reduced per capita publication productivity. These findings warrant further study.Other UBCNon UBCReviewedFacult
Enhanced Heat Transfer Properties of Magnetite Nanofluids due to Neel and Brownian Relaxation Mechanisms
Study on invasive fungal infections in immunocompromised patients to present a suitable early diagnostic procedure
Vacancy ordered γ-Fe2O3 nanoparticles functionalized with nanohydroxyapatite: XRD, FTIR, TEM, XPS and Mössbauer studies
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Older Blood Is Associated With Increased Mortality and Adverse Events in Massively Transfused Trauma Patients: Secondary Analysis of the PROPPR Trial
Study objectiveThe transfusion of older packed RBCs may be harmful in critically ill patients. We seek to determine the association between packed RBC age and mortality among trauma patients requiring massive packed RBC transfusion.MethodsWe analyzed data from the Pragmatic, Randomized Optimal Platelet and Plasma Ratios trial. Subjects in the parent trial included critically injured adult patients admitted to 1 of 12 North American Level I trauma centers who received at least 1 unit of packed RBCs and were predicted to require massive blood transfusion. The primary exposure was volume of packed RBC units transfused during the first 24 hours of hospitalization, stratified by packed RBC age category: 0 to 7 days, 8 to 14 days, 15 to 21 days, and greater than or equal to 22 days. The primary outcome was 24-hour mortality. We evaluated the association between transfused volume of each packed RBC age category and 24-hour survival, using random-effects logistic regression, adjusting for total packed RBC volume, patient age, sex, race, mechanism of injury, Injury Severity Score, Revised Trauma Score, clinical site, and trial treatment group.ResultsThe 678 patients included in the analysis received a total of 8,830 packed RBC units. One hundred patients (14.8%) died within the first 24 hours. On multivariable analysis, the number of packed RBCs greater than or equal to 22 days old was independently associated with increased 24-hour mortality (adjusted odds ratio [OR] 1.05 per packed RBC unit; 95% confidence interval [CI] 1.01 to 1.08): OR 0.97 for 0 to 7 days old (95% CI 0.88 to 1.08), OR 1.04 for 8 to 14 days old (95% CI 0.99 to 1.09), and OR 1.02 for 15 to 21 days old (95% CI 0.98 to 1.06). Results of sensitivity analyses were similar only among patients who received greater than or equal to 10 packed RBC units.ConclusionIncreasing quantities of older packed RBCs are associated with increased likelihood of 24-hour mortality in trauma patients receiving massive packed RBC transfusion (≥10 units), but not in those who receive fewer than 10 units
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Onset of Coagulation Function Recovery Is Delayed in Severely Injured Trauma Patients with Venous Thromboembolism
BackgroundAltered coagulation function after trauma can contribute to development of venous thromboembolism (VTE). Severe trauma impairs coagulation function, but the trajectory for recovery is not known. We hypothesized that enhanced, early recovery of coagulation function increases VTE risk in severely injured trauma patients.Study designSecondary analysis was performed on data from the Pragmatic Randomized Optimal Platelet and Plasma Ratio (PROPPR) trial, excluding patients who died within 24 hours or were on pre-injury anticoagulants. Patient characteristics, adverse outcomes, and parameters of platelet function and coagulation (thromboelastography) were compared from admission to 72 hours between VTE (n = 83) and non-VTE (n = 475) patients. A p value < 0.05 indicates significance.ResultsDespite similar patient demographics, VTE patients exhibited hypercoagulable thromboelastography parameters and enhanced platelet function at admission (p < 0.05). Both groups exhibited hypocoagulable thromboelastography parameters, platelet dysfunction, and suppressed clot lysis (low clot lysis at 30 minutes) 2 hours after admission (p < 0.05). The VTE patients exhibited delayed coagulation recovery (a significant change compared with 2 hours) of K-value (48 vs 24 hours), α-angle (no recovery), maximum amplitude (24 vs 12 hours), and clot lysis at 30 minutes (48 vs 12 hours). Platelet function recovery mediated by arachidonic acid (72 vs 4 hours), ADP (72 vs 12 hours), and collagen (48 vs 12 hours) was delayed in VTE patients. The VTE patients had lower mortality (4% vs 13%; p < 0.05), but fewer hospital-free days (0 days [interquartile range 0 to 8 days] vs 10 days [interquartile range 0 to 20 days]; p < 0.05) and higher complication rates (p < 0.05).ConclusionsRecovery from platelet dysfunction and coagulopathy after severe trauma were delayed in VTE patients. Suppressed clot lysis and compensatory mechanisms associated with altered coagulation that can potentiate VTE formation require additional investigation