Memorial University of Newfoundland

About: Memorial University of Newfoundland is a education organization based out in St. John's, Newfoundland and Labrador, Canada. It is known for research contribution in the topics: Population & Gadus. The organization has 13818 authors who have published 27785 publications receiving 743594 citations. The organization is also known as: Memorial University & Memorial University of Newfoundland and Labrador.

Dynamic risk assessment using failure assessment and Bayesian theory

Abstract: To ensure the safety of a process system, engineers use different methods to identify the potential hazards that may cause severe consequences. One of the most popular methods used is quantitative risk assessment (QRA) which quantifies the risk associated with a particular process activity. One of QRA's major disadvantages is its inability to update risk during the life of a process. As the process operates, abnormal events will result in incidents and near misses. These events are often called accident precursors. A conventional QRA process is unable to use the accident precursor information to revise the risk profile. To overcome this, a methodology has been proposed based on the work of Meel and Seider (2006). Similar to Meel and Seider (2006) work, this methodology uses Bayesian theory to update the likelihood of the event occurrence and also failure probability of the safety system. In this paper the proposed methodology is outlined and its application is demonstrated using a simple case study. First, potential accident scenarios are identified and represented in terms of an event tree, next, using the event tree and available failure data end-state probabilities are estimated. Subsequently, using the available accident precursor data, safety system failure likelihood and event tree end-state probabilities are revised. The methodology has been simulated using deterministic (point value) as well as probabilistic approach. This Methodology is applied to a case study demonstrating a storage tank containing highly hazardous chemicals. The comparison between conventional QRA and the results from dynamic failure assessment approach shows the significant deviation in system failure frequency throughout the life time of the process unit.

Wave-enhanced sediment-gravity flows and mud dispersal across continental shelves: Reappraising sediment transport processes operating in ancient mudstone successions

Abstract: Recent studies of marine shelf sediment dispersal show that wave-enhanced sediment-gravity flows are widespread phenomena and can transport large volumes of fluid mud rapidly across low-gradient shelves. Flow evolution is controlled by sediment supply, seabed gradient, and spatial distribution of wave energy at the seabed. Using existing flow models, we predict that such flows in mud-dominated sediments will develop a three-part microstratigraphy produced by changing flow conditions, beginning with wave-induced turbulent resuspension, then development of a wave-enhanced sediment-gravity flow, prior to lutocline collapse and suspension settling. Petrographic examination of modern flow deposits collected from the Eel Shelf reveals that resultant beds possess a microstratigraphy consistent with our hypothesis: a silt-rich basal subunit with curved ripple laminae, abruptly overlain by a subunit composed of continuous intercalated silt/clay laminae, and an upper clay-rich drape. Analyses of beds from ancient mud-rich outer-shelf and basinal successions (Cleveland Ironstone, Jurassic, UK, and Mowry Shale, Cretaceous, United States) show that they too contain beds with this three-part organization, suggesting that such flows were active in these ancient settings too. Recognition of these microstructures in these ancient mud-dominated successions demonstrates that sediment in these settings was commonly reworked and transported advectively downslope by high-energy events, contrasting with previous interpretations of these units that deposition was dominated by quiescent suspension settling. Identification of these recognition criteria now allows the products of this newly recognized sediment dispersal mechanism to be identified in other shale-dominated successions.

Privatization and bank performance in developing countries

Abstract: We examine the postprivatization performance of 81 banks from 22 developing countries. Our results suggest that: (i) On average, banks chosen for privatization have a lower economic efficiency, and a lower solvency than banks kept under government ownership. (ii) In the postprivatization period, profitability increases but, depending on the type of owner, efficiency, risk exposure and capitalization may worsen or improve. However, (iii) Over time, privatization yields significant improvements in economic efficiency and credit risk exposure. (iv) We also find that newly privatized banks that are controlled by local industrial groups become more exposed to credit risk and interest rate risk after privatization.

The Prevalence of Anxiety Disorders During Pregnancy and the Postpartum Period: A Multivariate Bayesian Meta-Analysis

Abstract: Objective To estimate the prevalence of anxiety disorders in pregnant and postpartum women and identify predictors accounting for variability across estimates. Data sources An electronic search of PsycINFO and PubMed was conducted from inception until July 2016, without date or language restrictions, and supplemented by articles referenced in the obtained sources. A Boolean search phrase utilized a combination of keywords related to pregnancy, postpartum, prevalence, and specific anxiety disorders. Study selection Articles reporting the prevalence of 1 or more of 8 common anxiety disorders in pregnant or postpartum women were included. A total of 2,613 records were retrieved, with 26 studies ultimately included. Data extraction Anxiety disorder prevalence and potential predictor variables (eg, parity) were extracted from each study. A Bayesian multivariate modeling approach estimated the prevalence and between-study heterogeneity of each disorder and the prevalence of having 1 or more anxiety disorder. Results Individual disorder prevalence estimates ranged from 1.1% for posttraumatic stress disorder to 4.8% for specific phobia, with the prevalence of having at least 1 or more anxiety disorder estimated to be 20.7% (95% highest density interval [16.7% to 25.4%]). Substantial between-study heterogeneity was observed, suggesting that "true" prevalence varies broadly across samples. There was evidence of a small (3.1%) tendency for pregnant women to be more susceptible to anxiety disorders than postpartum women. Conclusions Peripartum anxiety disorders are more prevalent than previously thought, with 1 in 5 women in a typical sample meeting diagnostic criteria for at least 1 disorder. These findings highlight the need for anxiety screening, education, and referral in obstetrics and gynecology settings.