Quantifying the Primary Emissions and Photochemical Formation of Isocyanic Acid Downwind of Oil Sands Operations

Isocyanic acid (HNCO) is a known toxic species and yet the relative importance of primary and secondary sources to regional HNCO and population exposure remains unclear. Off-road diesel fuel combustion has previously been suggested to be an important regional source of HNCO, which implies that major industrial facilities such as the oil sands (OS), which consume large quantities of diesel fuel, can be sources of HNCO. The OS emissions of nontraditional toxic species such as HNCO have not been assessed. Here, airborne measurements of HNCO were used to estimate primary and secondary HNCO for the oil sands. Approximately 6.2 ± 1.1 kg hr^-1 was emitted from off-road diesel activities within oil sands facilities, and an additional 116-186 kg hr^-1 formed from the photochemical oxidation of diesel exhaust. Together, the primary and secondary HNCO from OS operations represent a significant anthropogenic HNCO source in Canada. The secondary HNCO downwind of the OS was enhanced by up to a factor of 20 relative to its primary emission, an enhancement factor significantly greater than previously estimated from laboratory studies. Incorporating HNCO emissions and formation into a regional model demonstrated that the HNCO levels in Fort McMurray (∼10-70 km downwind of the OS) are controlled by OS emissions; > 50% of the monthly mean HNCO arose from the OS. While the mean HNCO levels in Fort McMurray are predicted to be below the 1000 pptv level associated with potential negative health impacts, (∼25 pptv in August-September), an order of magnitude increase in concentration is predicted (250-600 pptv) when the town is directly impacted by OS plumes. The results here highlight the importance of obtaining at-source HNCO emission factors and advancing the understanding of secondary HNCO formation mechanisms, to assess and improve HNCO population exposure predictions.

Werner syndrome protein: biochemical properties and functional interactions

Werner syndrome is a premature aging syndrome displaying numerous signs and symptoms found in normal aging. The disease is associated with a mutation in the WRN gene. We have purified the Werner protein (WRN) and studied its biochemical activities and its protein interactions. WRN is a helicase and an exonuclease and also has an associated ATPase activity. WRN interacts physically and functionally with replication protein A (RPA), which stimulates its helicase activity. We have studied the WRN exonuclease activity and found that it can be blocked by certain DNA lesions and not by others. Thus, while WRN does not bind to DNA damage, it may have properties that allow it to sense the presence of damage in DNA. More recently we have found other protein interactions that involve physical and functional interactions with WRN, which could suggest a role for WRN in DNA repair.

Boredom proneness: its relationship to psychological- and physical-health symptoms

The relationship between boredom proneness and health-symptom reporting was examined. Undergraduate students (N = 200) completed the Boredom Proneness Scale and the Hopkins Symptom Checklist. A multiple analysis of covariance indicated that individuals with high boredom-proneness total scores reported significantly higher ratings on all five subscales of the Hopkins Symptom Checklist (Obsessive-Compulsive, Somatization, Anxiety, Interpersonal Sensitivity, and Depression). The results suggest that boredom proneness may be an important element to consider when assessing symptom reporting. Implications for determining the effects of boredom proneness on psychological- and physical-health symptoms. as well as the application in clinical settings, are discussed.

Coeliac axis thrombosis associated with the combined oral contraceptive pill: a rare cause of an acute abdomen

We report a case of coeliac axis thrombosis and splenic infarction presenting in a girl of 14 years who had been on the oral contraceptive pill (OCP), Marvelon (ethinyloestradiol 30 microg plus desogestrel 150 microg, Organon, Cambridge, UK), for 3 weeks. She had no other risk factors for thrombo-embolism. Diagnosis was made with duplex Doppler ultrasound and confirmed with dynamically-enhanced comput-ed tomography and magnetic resonance angiography, thus avoiding the need for percutaneous arteriography. Though mesenteric thrombo-embolic disease is recognised in association with use of the combined OCP, it has not previously been reported to affect the coeliac axis. Paediatricians and surgeons should be aware of the risks to young girls on the OCP, and consider it in their differential diagnosis of the acute abdomen.

Clinical event management using push technology--implementation and evaluation at two health care centers

For two years, beginning in 1995, we developed and implemented a novel method for delivering patient information directly to clinicians. Using rules based logic to scan data bound for an electronic medical record, messages were automatically written that alert care providers to important patient information. These messages were transmitted electronically to either existing email accounts or to wide-screen pagers, or to both. This system now is operational at two medical centers. We describe the model and methods that led to its successful implementation and compare it to other ways of delivering patient information.