Integrated Risk Model Research Articles

Trajectories of language delay from age 3 to 5: persistence, recovery and late onset

Knowledge is scarce on what contributes to whether children with early language delay (LD) show persistent, recovering or sometimes late-onset LD without a prior history of early LD in subsequent preschool years. To explore whether an integrative model of vital risk factors, including poor early communication skills, family history of language-related difficulties and male gender, predicts the development of persistent, recovering or late-onset LD trajectories from 3 to 5 years quantitatively and qualitatively differently. LD was assessed by maternal reports on the Ages and Stages Questionnaire at 3 and 5 years for 10 587 children in The Norwegian Mother and Child Cohort Study. Children were classified across time as having no, late onset, transient or persistent LD. Multinomial logistic regression analyses included the integrative model of vital risk factors and covariates. Across time, 3%, 5% and 6.5% of the children displayed persistent, transient and late-onset LD, respectively. The odds for persistent LD were doubled for boys and children with low language comprehension at 1.5 years; and tripled by late-talking familial risk. These same odds decreased for transient LD, and even further for late-onset LD. Familial risk for writing and reading difficulties especially increased the odds for late-onset and persistent LD, while familial risk of unintelligible speech increased the odds for transient LD. Although girls had on average far better language comprehension than boys, low language comprehension was a stronger risk factor for persistent LD in girls. Preschool LD trajectories were uniquely predicted from the integrative risk model of poor early communicative skills, family history and male gender. This might benefit identification of different LD trajectories by supporting broader severe vulnerability for persistent LD, milder vulnerability for transient LD, and possibly a specific risk for reading and learning difficulties for children with late-onset LD.

An integrated stress testing framework via Markov switching simulation

Capturing tail events, especially those that include the rare possibility of severe loss, is one of the important objectives of modern risk analysis. However, the past behavior of financial data is not necessarily an accurate predictor of possible scenarios in the future. The economic turmoil of recent years has resulted in calls for a more forward-looking approach to financial risk management that integrates expert knowledge on plausible future scenarios with classical risk management models calibrated on past behavior. As a complementary risk analysis tool, stress testing is receiving more and more attention, both from regulators and from practitioners. Nevertheless, classical risk analysis models, such as value-at-risk models, that are based on historical data, are often disconnected from stress testing. This disconnection can prevent a comprehensive view of the risk profile of a financial institution. This paper proposes a multiperiod switching simulation based method for integrated stress testing risk analysis that incorporates plausible events that are not necessarily captured in historical data or in historical stressed calibration of risk models. Our application focuses on the integration of rare stress events and model stress into a market risk portfolio. However, the proposed method is also applicable to other financial risk models, eg, portfolio credit risk models. An integrated risk model and stress testing framework not only leads to forward-looking tail risk measurement, which mitigates the black swan effect, but also takes stress testing into advanced risk management decision making analysis, such as scenario-based portfolio optimization.

An Integrated Approach for Risk Assessment of CO2 Infrastructure in the COCATE Project

An innovative risk analysis model has been developed in order to quantify and analyse safety risks related to loss-of- containment scenarios in the pipeline transport of CO2. The risk model integrates the identified failure modes, consequence estimates and emergency response, producing consistent risk profiles based on complete outcome spaces and for different system design choices. The method involves integration in a Bayesian Belief Network (BN) of analytical equations for gas dispersion combined with statistics and expert estimates of particularly uncertain variables. Future failure initiators, scenarios and impacts are captured in a graphical structure which represents and calculates the effects of common causes. The test case for the integrated risk model will be a large CO2 capture and transport network at the Le Havre industrial zone with export to Rotterdam. The primary relative advantages of the BN risk model approach are discussed.

Integrating Gene and Mir Expression Profiles and Regulatory Network Structures to Define Aberrent Feed Forward Loops with Functional and Clinical Implications in Myeloma.

AbstractAbstract 2386Multiple myeloma (MM) is a clonal plasma cell malignancy with a heterogeneous genetic background. Extensive gene expression profile analysis have provided interesting insight into the disease biology and its correlation with clinical outcome; however, we have begun to realize the significant limitations of expression profile data alone. Therefore there is a growing understanding that additional genomic correlates need to be incorporated to develop an integrated oncogenomic analysis. We have here developed and defined multi-gene transcriptional and post-transcriptional feed-forward loop (FFL) These conceptual FFLs consist of a master TF which regulates a miR and together with it controls a set of specific common gene/s. These recurrent and important network motifs form functional nodes in the larger regulatory network, and are considered linchpins of disease causing genomic alterations in cancer and MM in particular. We have developed a comprehensive novel integrative analysis method, dChip-GemiNI (Gene and miRNA Network-based Integration), which combines gene and miR expression profiles, and also incorporates regulatory network structure in the form of computationally identified TF–miRNA FFLs. The dChip-GemiNI method statistically ranks computationally predicted FFLs by their explanatory power to account for differential gene and miRNA expression. We have next applied dChip-GemiNi to a training dataset of 60 MM patients and 5 normal plasma cells (NPCs) with both gene expression (GE) and miR profiles (dataset GSE16558) in order to identify FFLs containing TF-miR-gene networks with loss of negative feedback regulation in MM, supporting the uncontrolled growth, anti-apoptosis and/or other oncogenic effects. We have identified 20 FFLs significantly aberrant between NPC and MM cells. Prominent FFLs involve known MM dysregulated TFs such as MYC, TP53 and Sp1. In addition, we have utilized 3 available myeloma datasets with both miR and GE profiles (GSE16558, GSE17306, GSE17498), and classified MM samples into hyperdiploid MM (HMM) and non-hyperdiploid MM (NHMM) subtype groups by GE profiles at an accuracy >85%. These two groups have different survival outcomes (p-value < 0.01). We have identified 55 FFLs altered between these two MM subtypes. In particular we have observed that the FFL involving CREB1- miR-20a and target genes RRAGD, PIP4K2A, RHOC and CCND2 is altered between HMM and NHMM and is common between the 3 datasets. We have now begun to statistically ranks computationally predicted FFLs and develop a motif score to develop an integrated risk stratification model. In conclusion, FFLs form critical regulatory loops driving the functional behavior of MM cells. Analyzing the molecular impact of FFLs as a unit combining the aggregate impact of TF-miR and the target gene/s in MM will be instrumental in understanding the biology of the disease, developing clinically relevant integrated risk models, and translating basic research into targeted therapy. The ultimate goal is to develop strategies to regulate homeostatic control of these loops and overcome their oncogenic effects that drive the malignant phenotype. Disclosures:Munshi:Celgene: Consultancy; Millenium: Consultancy; Merck: Consultancy; Onyx: Consultancy.

POP accumulation in the food chain: Integrated risk model for sewage sludge application in agricultural soils

Because of its benefits to soil and crops, sewage sludge application on agricultural soils is a managing practice of increasing use. However, this practice may lead to contamination of the food chain, especially by persistent organic pollutants (POPs). The main objective of this study was to integrate probabilistic multimedia models to predict the accumulation of POPs in the food chain and the related risks to humans, as a consequence of sludge application on soil. For that, four models were integrated: (i) soil fate, (ii) plant, (iii) food chain and (iv) exposure and risk. These models were applied for two scenarios (occupational and non-occupationally exposed populations) in a time span of 30 years. The variability of the inputs and outputs was also considered. The model was applied to a case-study of 4 POPs (2,3,7,8TCDD, PCB 180, benzo(a)pyrene, and dibenzo(a,h)anthracene) in an agricultural soil located in Catalonia (NE of Spain). Some differences in cancer risk due to POP exposure were appreciated between both evaluated scenarios. However, all values were below the threshold levels. With the exception of 2,3,7,8TCDD, all the contaminants reached steady state on soil in the first five years of the evaluation. Concentration levels in food (vegetables, meat and milk) were linearly correlated to those in soils. Air inhalation was noted to be an occupational exposure route of minor importance. Sensitivity analysis for 2,3,7,8TCDD showed that exposure parameters were responsible for most of the variability in the results.

Use of Contingent Valuation to Elicit Willingness-to-Pay for the Benefits of Developmental Health Risk Reductions

We report the results of several contingent valuation (CV) surveys to elicit willingness-to-pay values from the general public for risk reductions associated with decreases in exposure to a chemical, PCBs, in the environment. We also develop Quality Adjusted Life Years (QALYs) from the survey using both standard gamble and time-tradeoff elicitation methods to explore the relationship between QALYs and willingness-to-pay (WTP), and to develop QALY weights for subtle developmental effects. The results of the CV surveys are designed for incorporation into a case study of an integrated risk model to monetize the benefits of predicted risk reductions. Respondents showed a nearly proportional, positive relationship between decreasing the risk of a 6-point reduction in IQ (a standard measure of “intelligence”) and WTP, but showed a negative relationship between risk reduction and WTP for reading comprehension as an outcome. The range of mortality risks that respondents would accept on behalf of their (hypothetical) 10-year-old child is 2 in 10,000 to 9 in 1,000 per IQ point, and WTP per IQ point is $466 ($380, $520). QALY weights elicited via time tradeoff (reduction in life expectancy) were significantly different from QALY weights elicited via a standard gamble (p = 0.001). Respondents who answered questions about ecological endpoints first were willing to pay a small additional amount when asked about human health effects, but those respondents who answered questions about human health endpoints first were not willing to pay any additional amount when subsequently asked about ecological effects.

Environmental Toxicity Testing in the Risk Assessment of a Metal Contaminated Abandoned Mining Site in Hungary

A three tiered, iterative Environmental Risk Assessment methodology, including preliminary Qualitative Risk Assessment, Quantitative Hazard Assessment and Site Specific Quantitative Risk Assessment, was established to assess the environmental risk of point and diffuse pollution of mining origin at catchment scale [1]. The model site was an abandoned Pb and Zn sulphide ore mine in Gyöngyösoroszi, Toka-valley, NE Hungary [2]. The Integrated Risk Model considers the sources identified by the GIS-based (Geographical Information System) pollution map, the transport routes shown by the GIS-based flow accumulation model and the receptors of different land uses in the catchment. The site-specific quantitative risk was characterised by the Soil Testing Triad [3]. The three elements of the Triad are: physico-chemical analyses of the soil and the contaminants, the biological characterisation and ecotoxicity testing of the contaminated soil, measuring the response of single species in laboratory bioassays, the natural response of the soil microflora and plants or the dynamic response of the whole soil in microcosms. The Triad approach strongly supports the characterisation of the site specific risk as well as the selection and planning of the suitable remediation option.

On the distribution tail of an integrated risk model: A numerical approach

We consider an insurance risk process with the possibility to invest the capital reserve into a portfolio consisting of a risky asset and a riskless asset. The stock price is modelled by an exponential Lévy process and the riskless interest rate is assumed to be constant. We aim at the risk assessment of the integrated risk process in terms of a high quantile or the far out distribution tail. We indicate an application to an optimal investment strategy of an insurer.

An Integrated IT Risk Model

The worldwide concern with corporate governance concerns itself, inter alia, with the risks that an organization faces; for many, IT is significant among those risks. This paper examines the audit approach, and others, to dealing with risks in IT-based systems. This paper summarizes the findings of research in IT-related areas of risk and then draws together a charter for IT governance that meets the wider needs of corporate governance. IT risks are collated in the form of a portfolio so that risk is dealt with in a positive, systematic manner. The portfolio sets out to be exhaustive so that all risk can be brought together under a single managerial role. The IT governance model balances risks with strategic goals and the specific benefits that are intended through the implementation of IT. A case study illustrates the application of the model.

Integrated risk modelling

In this article, we present a new approach to modelling the total economic capital required to protect a financial institution against possible losses. The approach takes into account the correlation between risk types, and in this respect, it improves upon the conventional practice that assumes perfectly correlated risks. A statistical model is built, and Monte Carlo simulation is used to estimate the total loss distribution. The methodology has been implemented in the Norwegian financial group DnB’s system for risk management. Incorporating current expert knowledge of relationships between risks, rather than taking the most conservative stand, gives a 20% reduction in the total economic capital for a one year time horizon.

An integrated risk model of a drinking-water-borne cryptosporidiosis outbreak.

A dynamic risk model is developed to track the occurrence and evolution of a drinking-water-borne cryptosporidiosis outbreak. The model characterizes and integrates the various environmental, medical, institutional, and behavioral factors that determine outbreak development and outcome. These include contaminant delivery and detection, water treatment efficiency, the timing of interventions, and the choices that people make when confronted with a known or suspected risk. The model is used to evaluate the efficacy of alternative strategies for improving risk management during an outbreak, and to identify priorities for improvements in the public health system. Modeling results indicate that the greatest opportunity for curtailing a large outbreak is realized by minimizing delays in identifying and correcting a drinking-water problem. If these delays cannot be reduced, then the effectiveness of risk communication in preemptively reaching and persuading target populations to avoid exposure becomes important.

Factors influencing occurrence and impacts of fires in northern European forests

The return interval and number of fires vary, depending on the geographical location in interaction with climate, topography and amount of fuel. During recent decades, in northern Europe the number and severity of fires have been insignificant compared with Mediterranean region, in which fire return intervals may be 15–35 years, compared to the average of 60–120 years for boreal forests. This is partly due to the efficient system of fire protection in northern Europe, but is mainly due to the less favourable climate for fire and the smaller human impact on ignition of forest fires. The consequences of fire are related to both site and stand characteristics, site being the most important factor controlling the stability of stands. Dry sites being more flammable and likely to ignite are associated with high risk of fire. In northern Europe, due to the interaction between species and site, the role of species difference in risk of fire damage is not clear. In southern Europe, fire risk cannot be explained by differences between tree species. There, other vegetation (shrubs, etc.) is of major importance for the risk of fire. Management of forests can, to some degree, alter the risk and the occurrence of fire. In northern Europe, logging may have compensated for fire occurrence by decreasing the amount of fuel. In addition, forest roads act as fire-breaks and facilitate fire-fighting. On the contrary, in southern Europe the risk of fire has been found to increase because the traditional forest uses and management have decreased, which increases the accumulation of fuel. However, it is not yet possible to quantify and compare the effect of management in absolute terms. Currently, some tools, such as fire-risk indices, remote sensing and GIS-based techniques, are available for prediction of fire risk in some areas. For example, fire-risk indices are most suitable for areas, like northern Europe, which have a low fire risk. In high-risk areas, such as southern Europe, more sophisticated techniques are needed for assessment of the risk. In the future, assuming global warming at northern latitudes (2 x CO2 climate), the risk of fire damage could also increase in northern Europe. Therefore, to allow the various locational and silvicultural factors to be assessed on the European level, an integrated risk model is needed.

SoilRisk: Risk Assessment Model for Organic Contaminants in Soil

This paper describes in detail a new integrated risk model, SoilRisk, for low-levels of organic pollutants in soil. An analytical model of the fate and transport of organics in unsaturated soil is used where chemical losses from the unsaturated zone occur due to first-order degradation, volatilization at the soil surface, and leaching to the saturated zone. The unsaturated zone module is linked to air dilution/dispersion, saturated zone transport, and dust generation modules to allow estimation of long-term average air, groundwater, respirable dust, and soil contaminant concentrations. With SoilRisk, the carcinogenic risk resulting from a specified contaminant concentration in soil or the contaminant concentration in soil to meet a specified level of risk can be estimated. These model outputs can be evaluated as single values or as cumulative distribution functions, depending on whether the input parameters are specified deterministically or probabilistically. In a subsequent paper, the model is applied to evaluate the risk implications of establishing uniform, concentration-based soil remediation goals.

The global impact of the Chernobyl reactor accident.

Radioactive material was deposited throughout the Northern Hemisphere as a result of the accident at the Chernobyl Nuclear Power Station on 26 April 1986. On the basis of a large amount of environmental data and new integrated dose assessment and risk models, the collective dose commitment to the approximately 3 billion inhabitants is calculated to be 930,000 person-gray, with 97% in the western Soviet Union and Europe. The best estimates for the lifetime expectation of fatal radiogenic cancer would increase the risk from 0 to 0.02% in Europe and 0 to 0.003% in the Northern Hemisphere. By means of an integration of the environmental data, it is estimated that approximately 100 petabecquerels of cesium-137 (1 PBq = 10(15) Bq) were released during and subsequent to the accident.