Water Quality in the Gillham Lake-Cossatot River System During Dry and Wet Periods

Water samples were collected in the Cossatot River-Gillham Lake system during an extended dry period and after heavy rains to determine the spatial variations in certain water quality characteristics. Of particular interest was the influence of the reservoir discharge on the water quality of the tailwater compared with the effects of four tributaries entering the tailwater below the reservoir. The water quality of the Cossatot River below Gillham Lake at low-flow (dry periods) and during the first 3 days after heavy rainfall (wet period) was influenced more by the tributaries entering the tailwater than by the reservoir water release. We estimated, however, that the amount of particulate inorganic matter released to the tailwater from the reservoir after the initial 3-day wet period would be greater than the amounts entering the tailwater from the tributaries

Not driving alone: Commuting in the Twenty-first century

This paper investigates recent commuting trends in American workers. Unlike most studies of commuting that rely on Census data, this study utilizes the unique American Time Use Survey to detail the complex commuting patterns of modern-day workers. The data confirm what has been suspected, that incidence of driving alone has decreased substantially in recent years while carpooling has rebounded. The results from the multi-nominal logistic estimation of workers' commuting choices yield support for both the traditional economic determinants as well as for the newer, socio-economic factors. In addition to the cost savings, many commuters appear to value the social aspect of carpooling. Surprisingly, there is little evidence that the need for autonomy plays much of a factor in explaining workerÕs choice of the journey to work. The estimated short-run elasticity of carpooling with respect to real gas prices appears to be quite high and largely accounts for the significant decline in the incidence of driving alone.Ride sharing, carpooling, commuting, gasoline process, social capital

Analyzing Chiral Symmetry Breaking in Supersymmetric Gauge Theories

We compare gap equation predictions for the spontaneous breaking of global symmetries in supersymmetric Yang-Mills theory to nonperturbative results from holomorphic effective action techniques. In the theory without matter fields, both approaches describe the formation of a gluino condensate. With $N_f$ flavors of quark and squark fields, and with $N_f$ below a certain critical value, the coupled gap equations have a solution for quark and gluino condensate formation, corresponding to breaking of global symmetries and of supersymmetry. This appears to disagree with the newer nonperturbative techniques, but the reliability of gap equations in this context and whether the solution represents the ground state remain unclear.Comment: LaTex, 14 pages, including 1 figure in EPS format. Revised to correct gluino anomalous dimension, with minor accompanying text change

Signatures of multiple stellar populations in unresolved extragalactic globular/ young massive star clusters

We present an investigation of potential signatures of the formation of multiple stellar populations in recently formed extragalactic star clusters. All of the Galactic globular clusters for which good samples of individual stellar abundances are available show evidence for multiple populations. This appears to require that multiple episodes of star formation and light element enrichment are the norm in the history of a globular cluster. We show that there are detectable observational signatures of multiple formation events in the unresolved spectra of massive, young extragalactic star clusters. We present the results of a pilot program to search for one of the cleanest signatures that we identify - the combined presence of emission lines from a very recently formed population and absorption lines from a somewhat older population. A possible example of such a system is identified in the Antennae galaxies. This source's spectrum shows evidence of two stellar populations with ages of 8 Myr and 80 Myr. Further investigation shows that these populations are in fact physically separated, but only by a projected distance of 59 pc. We show that the clusters are consistent with being bound and discuss the possibility that their coalescence could result in a single globular cluster hosting multiple stellar populations. While not the prototypical system proposed by most theories of the formation of multiple populations in clusters, the detection of this system in a small sample is both encouraging and interesting. Our investigation suggests that expanded surveys of massive young star clusters should detect more clusters with such signatures.Comment: 11 pages, 7 figures: accepted for publication in Ap

Limits on [OIII] 5007 emission from NGC4472's globular clusters: constraints on planetary nebulae and ultraluminous black hole X-ray binaries in globular clusters

We have searched for [OIII] 5007 emission in high resolution spectroscopic data from Flames/Giraffe VLT observations of 174 massive globular clusters (GCs) in NGC4472. No planetary nebulae (PNe) are observed in these clusters, constraining the number of PNe per bolometric luminosity, \alpha<0.8*10^{-7}PN/L_{\odot}. This is significantly lower than the rate predicted from stellar evolution, if all stars produce PNe. Comparing our results to populations of PNe in galaxies, we find most galaxies have a higher \alpha than these GCs (more PNe per bolometric luminosity - though some massive early-type galaxies do have similarly low \alpha). The low \alpha required in these GCs suggests that the number of PNe per bolometric luminosity does not increase strongly with decreasing mass or metallicity of the stellar population. We find no evidence for correlations between the presence of known GC PNe and either the presence of low mass X-ray binaries (LMXBs) or the stellar interaction rates in the GCs. This, and the low \alpha observed, suggests that the formation of PNe may not be enhanced in tight binary systems. These data do identify one [OIII] emission feature, this is the (previously published) broad [OIII] emission from the cluster RZ 2109. This emission is thought to originate from the LMXB in this cluster, which is accreting at super-Eddington rates. The absence of any similar [OIII] emission from the other clusters favors the hypothesis that this source is a black hole LMXB, rather than a neutron star LMXB with significant geometric beaming of its X-ray emission.Comment: 10 pages, 3 figures, accepted for publication in Ap

THE BLACK ORGAN AND TISSUE DONOR SHORTAGE: A REVIEW OF THE LITERATURE

On April 16, 1999, the Department of Health and Human Services and the United Network for Organ Sharing (UNOS) announced that the number of organ donors increased 5.6 percent in 1998, the first substantial increase since 1995. Donation increases between 1997 and 1998 were substantial for whites (up 6.6 percent from 4,139 to 4,410 donors) and Hispanics (up 7.8 percent from 552 to 595 donors). However, the number of black donors remained relatively unchanged at 654 donors in 1998, and the number of Asian donors decreased by 8.4 percent from 107 to 98 donors (HRSA, April 16, 1999)

A history of teacher organization

A book review of Power to the Teacher, by Marshall O. Donley, Jr

The Evolution of Creationism in Public Schools

In cases involving evolution and creation, the courts have made every effort to ensure that the wall of separation between church and state remains high and impregnable

A church-state compromise

Educators, school board members and parents are often caught between conflicting objectives