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Purpose: Four clinical active surveillance trials including LORIS, COMET, LORD and LORETTA, are being conducted to assess whether women with low-risk ductal carcinoma in situ can safely avoid surgery. The present study aimed to de...
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Purpose: Four clinical active surveillance trials including LORIS, COMET, LORD and LORETTA, are being conducted to assess whether women with low-risk ductal carcinoma in situ can safely avoid surgery. The present study aimed to determine the rate of upstaging to invasive cancer among patients with a preoperative diagnosis of ductal carcinoma in situ and to evaluate the incidence of upstaging in patients meeting the eligibility criteria for four active surveillance clinical trials.
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According to the reports of the World Health Organization (WHO), there has been an increased trend in the years of life lost and disability-adjusted life years because of coronary artery disease in India, in recent years. With adv...
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According to the reports of the World Health Organization (WHO), there has been an increased trend in the years of life lost and disability-adjusted life years because of coronary artery disease in India, in recent years. With advancement in the treatment modalities for patients diagnosed with cardiovascular disease (CVD), there has also been an increased emphasis on preventive cardiology. The risk of developing CVD over the next 10 years and the lifetime risk of CVD are assessed with the help of risk calculators such as atherosclerostic cardiovascular disease (ASCVD) risk calculators.1 This pooled cohort risk equation was developed from several large cohort studies including the atherosclerostic risk in communities study, the cardiovascular health study, and Coronary Artery Risk Development in Young Adults study and data from the Framingham Original and Offspring Study cohorts. These cohorts mainly included white and African-American participants. Although the pooled cohort risk predicts the CVD risk in whites and African Americans with accuracy as implied by various validation trails, its use in other races has not been well validated.
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Purpose Limited gastrectomy has been generally performed in clinical T1N0 gastric cancer. The aim of this study was to identify risk factors for stage underestimation in clinical T1N0 gastric cancer. Methods This study reviewed th...
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Purpose Limited gastrectomy has been generally performed in clinical T1N0 gastric cancer. The aim of this study was to identify risk factors for stage underestimation in clinical T1N0 gastric cancer. Methods This study reviewed the medical records of 566 patients who underwent gastrectomy for clinical T1N0 gastric cancer. Results The tumor stage was underestimated in 122 (21.6%) patients. The relapse-free survival rate was significantly lower in the patients with pathological stage II (P = 0.021) and III (P = 30 mm, undifferentiated adenocarcinoma and clinical tumor depth of SM were identified as independent risk factors for pathological stages II and III. The rate of pathological stages II and III was 0% in the patients with no risk factors, 3% in those with 1 risk factor, 10.5% in those with 2 risk factors, 19.8% in those with 3 risk factors and 50% in those with 4 risk factors. Conclusions Location, tumor size, undifferentiated adenocarcinoma and clinical tumor depth were independent risk factors for pathological stages II and III in clinical T1N0 gastric cancer.
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Seismic risk has received increased attention since the 2011 Fukushima accident in Japan. The seismic risk of a nuclear power plant is evaluated via seismic probabilistic safety assessment (PSA), for which several methods are avai...
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Seismic risk has received increased attention since the 2011 Fukushima accident in Japan. The seismic risk of a nuclear power plant is evaluated via seismic probabilistic safety assessment (PSA), for which several methods are available. Recently, the discrete approach has become widely used. This approximates the seismic risk by discretizing the ground motion level interval into a small number of subintervals with the expectation of providing a conservative result. The present study examines the effect of the number of subintervals upon the results of seismic risk quantification. It is demonstrated that a small number of subintervals may lead to either an underestimation or overestimation of the seismic risk depending on the ground motion level. The present paper also provides a method for finding the boundaries between overestimation and underestimation regions, and illustrates the effect of the number of subintervals upon the seismic risk evaluation with an example. By providing a method for determining the effect of a small number of subintervals upon the results of seismic risk quantification, the present study will assist seismic PSA analysts to determine the appropriate number of subintervals and to better understand seismic risk quantification.
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In recent years, there has been remarkable progress in our understanding of policy persistence, on the one hand, and of the psychological phenomenon of underreaction, on the other. Surprisingly, there has been no attempt to use ro...
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In recent years, there has been remarkable progress in our understanding of policy persistence, on the one hand, and of the psychological phenomenon of underreaction, on the other. Surprisingly, there has been no attempt to use robust findings, derived from these efforts, in order to understand the nuances of policy underreaction. Policy underreaction refers to systematically slow and/or insufficient response by policymakers to increased risk or opportunity, or no response at all. This article tries to give the concept of policy underreaction a robust analytical identity by integrating cognitive, social, psychological and emotional variables in the explanation of policy underreaction and by introducing a variation across different types of contextual sources of policy persistence as explanatory variables of this phenomenon. It develops an analytical framework that revolves around two key elements of decision making in situations of risk unfolding over time: (1) policymakers' underestimation and accurate estimation of increased risks and (2) intra- and extra-organizational sources of policy persistence. Based on these dimensions, the article identifies and illustrates four distinct modes of policy underreaction which reflect differences in the nature of implemented policy.
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Aggressive driving behaviors due to drivers’ underestimation of risks are one of the major causes of traffic accidents. Due to the complexity of factors influencing risk perception, the mechanism of risk underestimation remains u...
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Aggressive driving behaviors due to drivers’ underestimation of risks are one of the major causes of traffic accidents. Due to the complexity of factors influencing risk perception, the mechanism of risk underestimation remains unclear. In this study, the theory of planned behavior (TPB) was extended by adding a new variable, namely drivers’ normlessness, forming an extended TPB (ETPB) framework to analyze the factors influencing risk underestimation and the extent of their influence. A total of 376 drivers’ perceived characteristics of risk underestimation were collected through an online survey, and a structural equation model was applied to investigate the effects of normlessness, behavioral attitudes, subjective norm, and perceived behavioral control on the tendency to underestimate the risk. The results showed that the ETPB model can explain the variance in the underestimation risk behavior by 69%; perceptual behavior control, attitude, and subjective norm (in descending order) had significant positive effects on driver’s tendency to underestimate risk; the normlessness variable can directly promote attitude and underestimated risk behavior; drivers with low annual mileage, complete insurance coverage, and no prior accident experience were more likely to underestimate driving risk. The study contributes to understanding of risk perception characteristics and provide theoretical basis for reducing underestimated risk behavior.
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This study proposes a framework for developing a probabilistic lag time (PLT) equation by taking into account uncertainty factors, including the rainfall factor (i.e., the maximum rainfall intensity), the hydraulic factor (i.e., t...
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This study proposes a framework for developing a probabilistic lag time (PLT) equation by taking into account uncertainty factors, including the rainfall factor (i.e., the maximum rainfall intensity), the hydraulic factor (i.e., the roughness coefficient in the river), and the geometrical factors (the catchment area, the length, and the basin slope). The proposed PLT equation is established based on the lag time equation by means of the uncertainty and risk analysis, i.e., the advanced first-order and second-moment approach. Hourly rainfall data in the Bazhang River watershed are used in the model development and application. The results indicate that compared with observed lag times extracted from historical events, the observed ones are mostly located within the 95% confidence interval of the simulated lag times. In addition, the resulting underestimated risk from the PLT equation can reasonably represent the degree of the difference between the estimated lag time and observed lag time. Consequently, the proposed PLT equation not only estimates the lag time at specific locations along the river, but also provides a corresponding reliability.
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We propose a robust risk measurement approach that minimizes the expectation of overestimation plus underestimation costs. We consider uncertainty by taking the supremum over a collection of probability measures, relating our appr...
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We propose a robust risk measurement approach that minimizes the expectation of overestimation plus underestimation costs. We consider uncertainty by taking the supremum over a collection of probability measures, relating our approach to dual sets in the representation of coherent risk measures. We provide results that guarantee the existence of a solution and explore the properties of minimizer and minimum as risk and deviation measures, respectively. An empirical illustration is carried out to demonstrate the use of our approach in capital determination. (C) 2020 Elsevier B.V. All rights reserved.
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Estimating the cost of transportation tunnel projects during the feasibility stage is highly complex and challenging for state/ federal agencies. The use of traditional methods to estimate tunnel project costs has led to significa...
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Estimating the cost of transportation tunnel projects during the feasibility stage is highly complex and challenging for state/ federal agencies. The use of traditional methods to estimate tunnel project costs has led to significant cost underestimation because of limited information/data to compare different alternatives. To address cost underestimation, 40 cost estimating factors were identified by conducting a systematic literature review. Seven electronic databases were searched and articles were screened based on pre-established criteria. Of the 788 articles retrieved, 39 articles published from 1988 to 2013 met the inclusion criteria and were included in the review. The resulting data was analysed using descriptive and Anderson-Darling statistical methods. The results of the analysis showed that the top five factors contributing to cost underestimation were engineering and construction complexities, geological conditions, cost estimation, market conditions, and environmental requirements. The findings from the review showed the importance of incorporating the effect of each determined estimating factor by state/federal agencies or metropolitan planning organizations when preparing initial estimates to avoid cost underestimation and/or to reduce the errors associated with such estimates. Future research may be warranted to explore the possibility of weighting the factors.
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Risk, including economic risk, is increasingly a concern for public policy and management. The possibility of dealing effectively with risk is hampered, however, by lack of a sound empirical basis for risk assessment and managemen...
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Risk, including economic risk, is increasingly a concern for public policy and management. The possibility of dealing effectively with risk is hampered, however, by lack of a sound empirical basis for risk assessment and management. This article demonstrates the general point for cost and demand risks in urban rail projects. The article presents empirical evidence that allow valid economic risk assessment and management of urban rail projects, including benchmarking of individual or groups of projects. Benchmarking of the Copenhagen Metro is presented as a case in point. The approach developed is proposed as a model for other types of policies and projects in order to improve economic and financial risk assessment and management in policy and planning.
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