Evaluating temporal patterns of metals concentrations in floodplain lakes of the Athabasca Delta (Canada) relative to pre-industrial baselines.

Sediment quality monitoring is widely used to quantify extent of river pollution, but requires knowledge of pre-disturbance conditions in the potentially altered landscape. This has long been identified as a critical aspect to develop for addressing concerns of river pollution in the Alberta Oil Sands Region. Here, we use analyses of sediment cores from eight floodplain lakes spanning a 67 river-km transect across the Athabasca Delta to define pre-1920 (pre-industrial) baseline concentrations for vanadium and five primary pollutants. We then evaluate if sediment metals concentrations have become enriched above baseline since onset of oil sands development and other industrial activities. Results demonstrate no enrichment of metals concentrations (except zinc at one lake) and absence of consistent temporal increases above pre-industrial baselines. Thus, natural processes continue to dominate metal deposition in floodplain lakes of the Athabasca Delta -- an important finding to inform stewardship decisions. The pre-1920 metals concentrations baselines offer a useful tool for ongoing sediment monitoring in aquatic ecosystems of the Athabasca Delta.

Human pituitary gonadotropin index. I. Standardized LRH test criteria for evaluation of functional amenorrhea.

LRH test were carried out by giving 339 amenorrheic women and 74 normally menstruating volunteers an intravenous injection of 25 mug LRH (Hoe 471). Plasma LH and FSH were measured by RIA in two laboratories (Tuebingen and Ulm) using two standard reference preparations: LER 907 and 2nd IRP-HMG. The average conversion factors between the two standard preparations were calculated at 5.0 for LH and 25.0 for FSH. Furthermore, the estradiol-17beta levels were measured in 139 out of the 339 patients immediately before and 60 minutes after LRH injection. Taking the episodic and cyclic plasma gonadotropin fluctuations into consideration a shorthand system classifying the gonadotropin baseline (BI-BIV) and LH responses to 25 mug LRH (R0-R2) has been established and is referred to as Human Pituitary Gonadotropin Index (HPGI). It is possible to achieve reproducible gonadotropin results in two different laboratories using two different standard reference preparations. Two separate, randomly selected groups of amenorrheic women were found to have the same percent distribution of the HPGI. A correlation coefficient of r equal 0.67 between basal and LRH stimulated plasma LH levels does not sufficiently characterize the individual LH response behavior. A significant increase of plasma LH and FSH within the test period (60') reveals that the iv administration of 25 mug LRH represents an adequate dose for the LRH test in women. The HPGI which characterizes the functional state of gonadostat, may become a useful diagnostic index for evaluating women with anovulatory disease before, during, and after therapy.