Modelling the travel time of transit vehicles in real‐time through a GTFS‐based road network using GPS vehicle locations

Predicting the arrival time of a transit vehicle involves not only knowledge of its current position and schedule adherence, but also traffic conditions along the remainder of the route. Road networks are dynamic and can quickly change from free‐flowing to highly congested, which impacts the arrival time of transit vehicles, particularly buses which often share the road with other vehicles, so reliable predictions need to account for real‐time and future traffic conditions. The first step in this process is to construct a framework with which road state (traffic conditions) can be estimated using real‐time transit vehicle position data. Our proposed framework implements a vehicle model using a particle filter to estimate road travel times, which are used in a second model to estimate real‐time traffic conditions. Although development and testing took place in Auckland, New Zealand, we generalised each component to make the framework compatible with other public transport systems around the world. We demonstrate the real‐time feasibility and performance of our approach in real‐time, where a combination of R and C++ was used to obtain the necessary performance results. Future work will use these estimated traffic conditions in combination with historical data to obtain reliable arrival time predictions of transit vehicles.     

Diagnostic sequence of cocaine use disorder in relation to other mental health conditions among college students

Abstract

Objective: Cocaine use is increasing. Comorbidities and diagnostic sequencing are needed among college students to inform treatment of cocaine use disorder (CUD). Method: Using electronic medical records from the psychiatric clinic at the student health care center of a large, public university from 2005 to 2015, patients diagnosed with CUD were identified. Their top mental health conditions were identified and assessed to see whether the first diagnosis of these conditions was made (1) before, (2) at the same time as, or (3) after the first diagnosis of CUD. Results: Among the 50 CUD patients, their most common mental health comorbidities were alcohol use disorder, anxiety, depression, and cannabis use disorder. Anxiety and depression were likely to be diagnosed before CUD; alcohol and cannabis use disorders were likely to be diagnosed concurrently with CUD. Conclusion: Diagnostic sequencing can be used to inform screening, workup, and treatment for patients with CUD.     

Reducing the Risk of Injury from Table Saw Use: The Potential Benefits and Costs of Automatic Protection

The use of table saws in the United States is associated with approximately 28,000 emergency department (ED) visits and 2,000 cases of finger amputation per year. This article provides a quantitative estimate of the economic benefits of automatic protection systems that could be designed into new table saw products. Benefits are defined as reduced health‐care costs, enhanced production at work, and diminished pain and suffering. The present value of the benefits of automatic protection over the life of the table saw are interpreted as the switch‐point cost value, the maximum investment in automatic protection that can be justified by benefit‐cost comparison. Using two alternative methods for monetizing pain and suffering, the study finds switch‐point cost values of $753 and $561 per saw. These point estimates are sensitive to the values of inputs, especially the average cost of injury. The various switch‐point cost values are substantially higher than rough estimates of the incremental cost of automatic protection systems. Uncertainties and future research needs are discussed.     

Induced inefficiency as a response to the union threat

Milkman and Mitchell (1995) extend Rosen’s (1969) threat-effect hypothesis to suggest that the threat of unionization can induce inefficient underutilization of labor by nonunion firms. If firms follow this strategy, the apparent paradox of competitive coexistence in the face of higher union wages reflects induced nonunion firm inefficiency rather than superior union firm efficiency. Furthermore, this strategy decreases demand for nonunion workers in a partially unionized industry. A generalized cost function analysis of data from sawmills in the Pacific Northwest yields evidence that nonunion firms use this strategy.     

The EPA Health Risk Assessment of Methylcyclopentadienyl Manganese Tricarbonyl (MMT)

This paper describes the U.S. Environmental Protection Agency's assessment of potential health risks associated with the possible widespread use of a manganese (Mn)-based fuel additive, methylcyclopentadienyl manganese tricarbonyl (MMT). This assessment was significant in several respects and may be instructive in identifying certain methodological issues of general relevance to risk assessment. A major feature of the inhalation health risk assessment was the derivation of Mn inhalation reference concentration (RfC) estimates using various statistical approaches, including benchmark dose and Bayesian analyses. The exposure assessment component used data from the Particle Total Exposure Assessment Methodology (PTEAM) study and other sources to estimate personal exposure levels of particulate Mn attributable to the permitted use of MMT in leaded gasoline in Riverside, CA, at the time of the PTEAM study; on this basis it was then possible to predict a distribution of possible future exposure levels associated with the use of MMT in all unleaded gasoline. Qualitative as well as quantitative aspects of the risk characterization are summarized, along with inherent uncertainties due to data limitations.     

Limits to social capital: comparing network assistance in two New Orleans neighborhoods devastated by Hurricane Katrina

Sociological research emphasizes that personal networks offer social resources in times of need and that this capacity varies by the social position of those involved. Yet rarely are sociologists able to make direct comparisons of such inequalities. This study overcomes this methodological challenge by examining network activation among residents of two unequal neighborhoods severely devastated by Hurricane Katrina. Results indicate that local network capacities of Lower Ninth Ward residents relative to those of the more affluent Lakeview neighborhood dissipated before, during, and after the disaster to erode the life chances of individual residents and the neighborhood they once constituted.     

Discourse Analysis in Career Counseling and Development

Discourse analysis can be used to understand and interpret culturally and socially produced meanings regarding work and to outline how specific rules and conventions can configure meaning production of work in context. The implications of some core concepts in discourse analysis pertinent to career counseling are explored, including discourse, deconstruction, power/knowledge, psy‐complex, ideology, and identity. Such an exploration has the potential to initiate a process of critical self‐reflection in career counseling and development so as to enhance ethical, fair, and inclusive practices in the field.