Modeling the contribution of speeding and impaired driving to insurance claim counts and costs when contributing factors are unknown

PROBLEM: There are no specific indicators for distinguishing insurance claims related to speeding and impaired driving in the information warehouse at the Insurance Corporation of British Columbia. Contributing factors are only recorded for that part of the claim data that is also reported by the police. Most published statistics on crashes that are related to alcohol or speeding are based on police-reported data, but this represents only a fraction of all incidents. METHOD: This paper proposes surrogate models to estimate the counts and the average costs associated with speeding and impaired driving to insurance claims when contributing factors are unknown. Using police-reported data, classification rules and logistic regression models are developed to form such estimates. One approach applies classification rules to categorize insurance claims into those related to speeding, impaired driving, and other factors. The counts and the costs of insurance claims for each of these strata and overall are then estimated. A second method models the probability that an insurance claim is related to speeding or impaired driving using logistic regression and uses this to estimate the overall counts and the average costs of the claims. The two methods are compared and evaluated using simulation studies. RESULTS: The logistic regression model was found to be superior to the classification model for predicting insurance claim counts by category, but less efficient at predicting average claim costs. IMPACT: Having estimates of counts and costs of insurance claims related to impaired driving or speeding for all reported crash events provides a more accurate basis for policy-makers to plan changes and benefits of road safety programs.     

Estimating the contributions of speeding and impaired driving to insurance claim cost

INTRODUCTION: Logistic regression modelling of crash counts likely associated with speeding and impaired driving was earlier found [Zheng, Y., Cooper, P. J., & Dean, C. B. (2007). Modeling the contribution of speeding and impaired driving to insurance claim counts and costs when contributing factors are unknown. Journal of Safety Research, 38(1)] to successfully predict known outcomes in a series of simulations, but the same types of models did not accurately predict average crash costs. The aim of the study reported here was to develop a means to adjust classification model results that would improve their cost-predicting efficiency. METHOD: A classification modelling process was adjusted at the back-end using non-linear optimization to rationalize the classified proportions with the true proportions when the model was applied to representative subsets of the training data. Corrections were developed to account for cost (severity) differences arising from the classification process that were not due to true variations. The process was then applied to insurance claim test data where crash contributors were unknown. RESULTS: The optimization and severity correction procedure resulted in substantial improvement in average crash cost prediction for both impaired and unsafe speed collision involvements. The error measured against true values in 20 simulations was about half for the adjusted classification model of what it was for either unadjusted classification or logistic regression models. CONCLUSIONS: Non-linear optimization of classification matrices appears to be a workable tool for improving the predictive efficiency of models where desired outcomes represent average characteristics of records as compared to simple counts or proportions. IMPACT ON INDUSTRY: Using the methodology on a full-year of insurance claim data indicated that reliance on police-reported records alone would have underestimated the total cost of unsafe speed and impaired crashes by about 40%. Since most jurisdictions use police data to base policy decisions and set program spending around such safety issues, this finding has important implications.     

Inventories and Distribution of Radiocaesium in Arctic Marine Sediments: Influence of Biological and Physical Processes

Abstract

Extensive surveys of sediment burdens of radiocaesium, specifically ¹³⁷Cs, and other radioactive contaminants in the Arctic during the 1990′s, indicate that almost all anthropogenic radionuclides buried on continental shelves adjacent to Alaska are derived from global bomb fallout. the ¹³⁷Cs (half-life: 30.2y) activities observed in surface (0–4 cm) marine sediments however, vary widely, albeit much less than the expected current inventory resulting from bomb fallout at this latitude (～100mBq cm^?2). This observed geographical variation provided the opportunity to evaluate physical and biological mechanisms that may affect caesium biogeochemistry on Arctic continental shelves. We investigated whether high biological productivity in portions of the Bering and Chukchi Seas is effective in removing dissolved radiocaesium from the water column, and whether biological production in overlying water affects total radiocaesium inventories in sediments. Based upon C/N ratios in the organic fraction of shallow sediments, we found no evidence that higher inventories or surface activities of radiocaesium are present in areas with higher deposition of particulate organic matter. Based upon stable carbon isotope ratios of organic matter in sediments, we found no evidence that terrestrial runoff contributes proportionally to higher surface activities, although terrestrial runoff may affect total inventories of the radionuclide. Radiocaesium content of surface sediments was significantly correlated with total organic carbon content of sediments and the proportion of sediments in the finest sediment fractions. Because high current flow can also be expected to influence distributions of those sedimentary parameters, we conclude that re-distribution of     

Corporate Social Responsibility (CSR) practices developed by Brazilian companies: an exploratory study

In a world where companies have major influence over the economy, politics, and environment, they must be held accountable for their actions. With this in mind, the publication of sustainability reports is in a company’s best interest, since the disclosure of Corporate Social Responsibility (CSR) and sustainable practices can bring enormous advantages, largely related to a company’s image. The amount of information presented in sustainability reports turns them into valuable sources for research data, allowing analyses related to CSR and management practices, stakeholder relations, language used, among others. However, there is no a paper in the literature that analyzes theses information jointly for the Brazilian companies, and then we decided to explore this theme. This research aimed to identify advances and gaps of CSR practices performed by Brazil companies, through the analysis of 30 sustainability reports published between 2014 and 2015. The main findings indicate that, in general, the analyzed companies are experienced in sustainability reporting; however, there is still room for improvements, including a better mapping and reporting of practices involving the integration of CSR to organizational structure, stakeholder engagement, and continuous improvement practices.     

Photocatalytic ozonation of pesticides in a fixed bed flow through UVA-LED photoreactor

In this study, a fixed bed flow through UVA-LED photoreactor was used to compare the efficiency of ozone, photocatalysis and photocatalysis-ozone degradation, and mineralization of two pure pesticides, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methyl-4-chlorophenoxyacetic acid (MCPA), and a commercial one, Killex®. For the degradation of the parent compounds, ozone-based processes were more effective. While for mineralization, photocatalytic processes were more effective. Photocatalytic ozonation was the most efficient process for both the degradation and mineralization of the parent compounds. The degradation rates and mineralization by photocatalytic ozonation were higher than the summation of the corresponding rates by ozonation and photocatalysis, indicating a symbiotic relationship.Overall, the photocatalytic ozonation process with the fixed bed TiO₂ reduces the time needed for the degradation and mineralization of the pesticides, reduces the costs of powder catalyst separation and overcomes the reduced efficiency of immobilized catalysts, which makes the process quite attractive for practical applications.     

Mechanisms of biodegradation of dibenzoate plasticizers

Biodegradation mechanisms were elucidated for three dibenzoate plasticizers: diethylene glycol dibenzoate (D(EG)DB), dipropylene glycol dibenzoate (D(PG)DB), both of which are commercially available, and 1,6-hexanediol dibenzoate, a potential green plasticizer. Degradation studies were done using Rhodococcus rhodochrous in the presence of pure alkanes as a co-substrate. As expected, the first degradation step for all of these systems was the hydrolysis of one ester bond with the release of benzoic acid and a monoester. Subsequent biodegradation of the monobenzoates of diethylene glycol (D(EG)MB) and dipropylene glycol (D(PG)MB) was very slow, leading to significant accumulation of these monoesters. In contrast, 1,6-hexanediol monobenzoate was quickly degraded and characterization of the metabolites indicated that the biodegradation proceeded by way of the oxidation of the alcohol group to generate 6-(benzoyloxy) hexanoic acid followed by β-oxidation steps. This pathway was blocked for D(EG)MB and D(PG)MB by the presence of an ether function.The use of a pure hydrocarbon as a co-substrate resulted in the formation of another class of metabolites; namely the esters of the alcohols formed by the oxidation of the alkanes and the benzoic acid released by hydrolysis of the original diesters. These metabolites were biodegraded without the accumulation of any intermediates.     

Mitigation of two pyrethroid insecticides in a Mississippi Delta constructed wetland

Constructed wetlands are a suggested best management practice to help mitigate agricultural runoff before entering receiving aquatic ecosystems. A constructed wetland system (180 m × 30 m), comprising a sediment retention basin and two treatment cells, was used to determine the fate and transport of simulated runoff containing the pyrethroid insecticides lambda-cyhalothrin and cyfluthrin, as well as suspended sediment. Wetland water, sediment, and plant samples were collected spatially and temporally over 55 d. Results showed 49 and 76% of the study's measured lambda-cyhalothrin and cyfluthrin masses were associated with vegetation, respectively. Based on conservative effects concentrations for invertebrates and regression analyses of maximum observed wetland aqueous concentrations, a wetland length of 215 m × 30 m width would be required to adequately mitigate 1% pesticide runoff from a 14 ha contributing area. Results of this experiment can be used to model future design specifications for constructed wetland mitigation of pyrethroid insecticides.     

Lingual and biting responses to prey chemicals by ingestively naive scincid lizards: discrimination from control chemicals,time course,and effect of method of stimulus presentation

Summary. We tested responses to prey chemicals by lizard hatchlings of an oviparous species and neonates of a viviparous species, neither of which had never eaten. Both species responded more strongly to prey chemicals than to odorous and odorless control stimuli presented on cotton swabs. Although only a few species have been examined, all that have been tested have an innate capacity for prey chemical discrimination, suggesting that this innate response to prey chemicals is widespread among lizards that use the lingual-vomeronasal system to locate and identify prey. Innate prey chemical discrimination has the great advantage of permitting lizards lacking prior experience with food to respond appropriately to chemical cues associated with food. Both species discriminated prey chemicals from control substances at age three days, earlier than previously known. Our data hint that Mabuya macularia may be capable of discrimination on its day of birth, but further study is needed to determine the exact onset. A stronger tendency to attack swabs bearing prey chemicals by Scincella lateralis than by M. macularia may be explained by differences in defensiveness near an experimenter or by differences in the importance of visual prey cues for confirmation of chemical cues in the natural habitats of these species. In M. macularia responses to the control stimuli declined over days of testing, suggesting habituation, but responses to prey chemicals did not habituate by the third day of testing, which is interpreted as a possible adaptive response to permit location of food. In the standard method of stimulus presentation, a cotton swab bearing a chemical stimulus is placed anterior to a lizard's snout. We tested a new method in which the swab was placed in continuous contact with the lizard's anterior labial scales. The new method elicited significantly stronger responses from M. macularia. We discuss reasons for this finding and applications for the new method. Received 2 September 1999; accepted 15 December 1999