The increase in dissolved organic carbon (DOC) concentrations in freshwater systems has received considerable attention due to its implications for drinking water treatment and numerous limnological processes. While past studies have documented the influence of recovery from acidification and climate change on long-term DOC trends, the emerging importance of these explanatory factors remains less understood. In addition, few studies have followed up on recent trends in sites that have undergone increases in DOC.
View Article and Find Full Text PDFReservoirs are vital to meet the ever-increasing demands for freshwater in a warming climate. Dissolved organic matter (DOM) represents an important pool of carbon and can be a major concern in drinking water sources. However, insights into DOM dynamics in temperate, semi-arid reservoirs remain limited.
View Article and Find Full Text PDFAn in vitro study was carried out to examine the impact of UV exposure on metal-dissolved humic material (M-DHM) complexes in aqueous systems at different pH. Complexation reactions of dissolved M (Cu, Ni, and Cd) with DHM increased with the increasing pH of the solution. Kinetically inert M-DHM complexes dominated at higher pH in the test solutions.
View Article and Find Full Text PDFDiverse environmental and anthropogenic factors, such as the ongoing reservoir constructions may influence riverine dissolved organic matter (DOM) properties. This has important implications for river water quality, particularly when reservoirs are a source of drinking water. Simultaneous studies of multidecadal trends in dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) are scarce.
View Article and Find Full Text PDFChanges in hydro-meteorological conditions due to warming climate and the operation of reservoirs may support algal blooms. Lake Diefenbaker is a large reservoir on the Canadian Prairies. Annual flow volume from its major tributary, the South Saskatchewan River (SSR), varies with precipitation and temperature in the Rocky Mountains.
View Article and Find Full Text PDFLong-term patterns in dissolved organic carbon (DOC) concentrations in 49 eastern Canadian lakes from four sites were re-examined with a ~ 35-year (~1980-2015) dataset. The study sites were Dorset (number of lakes, n = 8), Experimental Lakes Area (ELA, n = 4), Kejimkujik (n = 26) and Yarmouth (n = 11). Lake DOC patterns were synchronous within each site.
View Article and Find Full Text PDFTurbidity affects a variety of aquatic ecosystem processes. Turbidity events are dominated by suspended sediment in many systems. High levels of suspended sediment in lakes can occur during periods of high inflows from turbid tributaries or suspension of sediment from lake beds.
View Article and Find Full Text PDFIn 2011, the U.S. Department of Health and Human Services added critical congenital heart disease (CCHD), which occurs in two of every 1,000 births, to the list of conditions recommended to states for universal newborn screening (1).
View Article and Find Full Text PDFIn this study, we built a two-dimensional sediment transport model of Lake Diefenbaker, Saskatchewan, Canada. It was calibrated by using measured turbidity data from stations along the reservoir and satellite images based on a flood event in 2013. In June 2013, there was heavy rainfall for two consecutive days on the frozen and snow-covered ground in the higher elevations of western Alberta, Canada.
View Article and Find Full Text PDFCritical congenital heart defects (CCHD) occur in approximately two of every 1,000 live births. Newborn screening provides an opportunity for reducing infant morbidity and mortality. In September 2011, the U.
View Article and Find Full Text PDFA fundamental step in the management of nutrient impacted water bodies is the determination of the type and degree of nutrient limitation. However, nutrient deficiency indicators often provide inconsistent results. Recent advances in the measurement of phosphate concentrations may provide a better means to understand results from P deficiency indicators.
View Article and Find Full Text PDFWe investigated the effect of ultraviolet radiation (UVR) on the uptake and partitioning of radiophosphate ((33)PO (4) (3-) ) in size-fractionated plankton assemblages (0.2-0.8, 0.
View Article and Find Full Text PDFBackground: Drug use has been associated with risk behaviour among gay men. We examined the use of drugs and sexual risk behaviour among homosexually-active men who engaged in group sex in Australia.
Methods: We used an anonymous, self-complete survey about participants' most recent occasion of group sex with other men and in-depth interviews with a small number of these survey participants.
Background: Musculotendinous stiffness provides an estimate of resistance to joint perturbation, thus contributing to joint stability. Females demonstrate lesser hamstring stiffness than males, potentially contributing to the sex discrepancy in anterior cruciate ligament injury risk. However, it is unclear if the sex difference in hamstring stiffness is due to differences in muscle size or to inherent/material properties of the musculotendinous unit.
View Article and Find Full Text PDFThe hamstrings limit anterior cruciate ligament (ACL) loading, and neuromuscular control of these muscles is crucial for dynamic knee joint stability. Sex differences in electromechanical delay (EMD) and rate of force production (RFP) have been reported previously, and attributed to differences in musculotendinous stiffness (MTS). These characteristics define the neuromechanical response to joint perturbation, and sex differences in these characteristics may contribute to the greater female ACL injury risk.
View Article and Find Full Text PDFWe investigated the usefulness of phytoplankton for the removal of surface water contaminants. Nine large mesocosms (92.2m(3)) were suspended in the flooded DJX uranium pit at Cluff Lake (Saskatchewan, Canada), and filled with highly contaminated mine water.
View Article and Find Full Text PDFBackground: The accurate measurement of total body and subcutaneous fat is essential if therapeutic interventions, aimed at preventing or reversing lipodystrophy syndrome, are to be adequately assessed. The aim of this study was to investigate the variability of dual-energy X-ray absorptiometry (DEXA) scans analysis performed at local sites compared to central analysis in a multicenter clinical trial.
Method: The PIILR study was a multicenter randomized clinical trial in which 80 HIV-infected patients with physician-documented lipodystrophy had serial measurements of body composition performed with Lunar DEXA scans.
Context: Peripheral lipoatrophy may complicate antiretroviral therapy of human immunodeficiency virus (HIV) infection, often related to duration and type of nucleoside analog therapy, and may have a mitochondrial pathogenesis. No proven therapy exists for lipoatrophy, but abacavir is a nucleoside analog that may be less toxic to mitochondria.
Objective: To determine if substitution of stavudine or zidovudine with abacavir improves HIV lipoatrophy without affecting control of HIV replication.