Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Scatterscore: a reconnaissance method to evaluate changes in water quality

Water quality data collected in periodic monitoring programs are often difficult to evaluate, especially if the number of parameters is large, the sampling schedule varies, and values are of different orders of magnitude. The Scatterscore Water Quality Evaluation was developed to yield a quantitative score, based on all measured variables in periodic water quality reports, indicating positive, negative or random change. This new methodology calculates a reconnaissance score based on the differences between up-gradient (control) versus down-gradient (treatment) water quality data sets. All parameters measured over a period of time at two or more sampling points are compared. The relationship between the ranges of measured values and the ratio of the medians for each parameter produces a data point that falls into one of four sections on a scattergram. The number and average values of positive, negative and random change points is used to calculate a Scatterscore that indicates the magnitude and direction of overall change in water quality. The Scatterscore Water Quality Evaluation, a reconnaissance method to track general changes, has been applied to 20 sites at which coal utilization by-products (CUB) were used to control acid mine drainage (AMD).