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Analyzes the efficiency of normal and lognormal probability functions in measuring concentrations of trace elements in air particulates in Quebec. Concentrations, skewness and goodness to fit test values of elements in the air particulates; Efficiency of probabilities in determining the coefficient of skewness; Observations of the chi-square test.

Manure storage is a well known source of anthropogenic ammonia emissions and has been the subject of numerous studies in Western Europe and the U.S. However, climate and manure management practices differ widely in Canada. In this study, commercial dairy and swine manure storages covered by floating geomembranes were monitored for periods exceeding six months in Canada. The swine manure storage emitted negligible amounts of ammonia over the summer, from 5.8 x 10-3 to 0.13 µg m-2 s-1, much lower than emission rates found in the literature for swine manure, which ranged between 45 and 875 µg m-2 s-1. The most substantial ammonia emissions at the swine facility occurred during manure mixing operations. A structural difference in the covering technology at the dairy manure storage rendered it less airtight than at the swine manure storage. The dairy manure storage emitted more substantial amounts of ammonia when unfrozen (91 to 171 µg m-2 s-1 then when frozen during winter (1.9 to 16 µg m-2 s-1). These emission rates are lower in magnitude than values found in the literature for dairy manure, which ranged between 10 and 864 µg m-2 s-1. Average relative uncertainties of emission rate measurements were estimated to be 8%, 26%, and 26%, respectively, for unfrozen dairy manure, frozen dairy manure, and swine manure. [ABSTRACT FROM AUTHOR]

Background: Acute rejection (AR) is associated with worse renal allograft outcomes. Therefore, this study investigated single-nucleotide polymorphisms (SNPs) to identify genetic variants associated with AR, accounting for center variation, in a multicenter, prospective, observation study., Methods: We enrolled patients from six transplant centers, five in the United States and one in Canada. A total of 2724 SNPs were genotyped. We accounted for center variation in AR rates by stratifying by transplant center and using novel knowledge discovery methods., Results: There was significant center variation in AR rates across the six transplant sites (P<0.0001). Accounting for this difference and clinical factors independently associated with AR, we identified 15 novel SNPs associated with AR with stratification by transplant center (P<0.05). We also identified 15 novel SNPs associated with severity of tubulitis scores, after adjusting for transplant center and other clinical factors independently associated with severity of tubulitis (P<0.05). There was some overlap with one SNP associated with AR and also associated with severity of tubulitis, among the top 15 SNPs., Conclusion: Center-to-center variation is a major challenge to genomic studies focused on AR. The SNPs associated with AR and severity of tubulitis in this study will need to be validated in independent cohort of kidney transplant recipients.

Death with function causes half of late kidney transplant failures, and cardiovascular disease (CVD) is the most common cause of death in these patients. We examined the use of potentially cardioprotective medications in a prospective observational study at seven transplant centers in the United States and Canada. Among 935 patients, 87% received antihypertensive medications at both 1 and 6 months after transplantation. Similar antihypertensive regimens were used for patients with and without diabetes and CVD, but with wide variability among centers. In contrast, while 44% of patients were on angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) at the time of transplantation, the proportion taking these agents dropped to 12% at month 1, then increased to 24% at 6 months. Fewer than 30% with CVD or diabetes received ACEI/ARB therapy 6 months posttransplant. Aspirin use was uncommon (<40% of patients). Even among those with diabetes and/or CVD, fewer than 60% received aspirin and only half received a statin at 1 and 6 months. This study demonstrates marked variability in the use of cardioprotective medications in kidney transplant recipients, a finding that may reflect, among several possible explanations, clinical uncertainty due the lack of randomized trials for these medications in this population.