Cavefish Population Status and Environmental Quality in Cave Springs Cave, Arkansas - Final Report submitted to Arkansas Natural Heritage Commission

This report summarizes the continuing effort to monitor environmental quality in the Cave Springs Cave Natural Area and to implement the Ozark Cavefish Recovery Plan. Last year’s report (Brown et al., 1998) identified certain environmental stressors, including a trend over 15 years of increasing nutrient pollution, a low cavefish population count of only 106, and the presence of heavy metals in the cave water and one semi-volatile organic compound (the phthalate DEHP at 500 ppb) in resident crayfish tissue. This year’s monitoring effort demonstrates that fecal coliforms continue to exceed Arkansas State Water Quality Standards (Regulation 2), sometimes by a factor of 1000. The presence of heavy metals is confirmed, in not only the cave water and sediments, but in crayfish tissue, which implies that it may be bioaccumulating in the cave foodweb. Furthermore, beryllium, copper, lead, selenium, and zinc are present in concentrations in the cave water that exceeded the Regulation 2 standards for chronic, and sometimes acute, toxicity to aquatic life. Significant amounts of nitrate are also present (with a yearly average of over 5 mg NO3-N/ L), and phosphate concentrations occasionally exceed Regulation 2 standards. Concentrations of nitrate, ortho-phosphate, total phosphate, total coliforms, and several dissolved metals (Al, Ba, Cu, Fe, and Pb) were all highly correlated with discharge, and concentrations were highest during stormflow events. No pesticides were detected in cave water, crayfish tissue or bat guano. Phthalates were again detected in crayfish tissue (DEP and DEHP at 1 ppb each), as well as the cave water (DEHP at 0.7 ppb). While the effects of these phthalates upon aquatic organisms are unknown, the U. S. Environmental Protection Agency considers phthalates to be human carcinogens and hormone disrupters. Ironically, while the cavefish habitat appears to be quite polluted, this year’s population survey counted 166 Ozark cavefish, the most ever counted for this (or any other) habitat. In order to integrate these pollution concerns and other data about this cave complex, a geographic information system was created for the Cave Springs Cave recharge zone. Preliminary analyses have detected several sensitive areas and pollution sources. The cave complex was determined to extend outside of the Natural Area boundary, and several sinkholes were identified. Photo-lineaments and fracture traces were identified, and other studies in Benton County demonstrate that these features, commonly expressed as intermittent streams on the surface, allow surface pollutants to rapidly enter the groundwater. Protection of these adjacent lands, sinkholes, and streams is recommended. The reduction or cessation of the land application of sewage sludge and agricultural waste in the recharge zone is also recommended

Matter formed at the BNL relativistic heavy ion collider

We suggest that the "new form of matter" found just above $T_c$ by RHIC is made up of tightly bound quark-antiquark pairs, essentially 32 chirally restored (more precisely, nearly massless) mesons of the quantum numbers of $\pi$, $\sigma$, $\rho$ and $a_1$. Taking the results of lattice gauge simulations (LGS) for the color Coulomb potential from the work of the Bielefeld group and feeding this into a relativistic two-body code, after modifying the heavy-quark lattice results so as to include the velocity-velocity interaction, all ground-state eigenvalues of the 32 mesons go to zero at $T_c$ just as they do from below $T_c$ as predicted by the vector manifestation (VM in short) of hidden local symmetry. This could explain the rapid rise in entropy up to $T_c$ found in LGS calculations. We argue that how the dynamics work can be understood from the behavior of the hard and soft glue.Comment: Final versio

Statistical evaluation of control inputs and eye movements in the use of instruments clusters during aircraft landing

Two different types of analyses were done on data from a study in which eye movements and other variables were recorded while four pilots executed landing sequences in a Boeing 737 simulation. Various conditions were manupulated, including changes in turbulence, starting position, and instrumentation. Control inputs were analyzed in the context of the various conditions and compared against ratings of workload obtained using the Cooper-Harper scale. A number of eye-scanning measures including mean dwell time and transition from one instrument to another were entered into a principal components factor analysis. The results show a differentiation between control inputs and eye-scanning behavior. This shows the need for improved definition of workload and experiments to uncover the important differences among control inputs, eye-scanning and cognitive processes of the pilot

Predicting the hypervelocity star population in Gaia

Hypervelocity stars (HVSs) are amongst the fastest objects in our Milky Way. These stars are predicted to come from the Galactic center (GC) and travel along unbound orbits across the Galaxy. In the coming years, the ESA satellite Gaia will provide the most complete and accurate catalogue of the Milky Way, with full astrometric parameters for more than $1$ billion stars. In this paper, we present the expected sample size and properties (mass, magnitude, spatial, velocity distributions) of HVSs in the Gaia stellar catalogue. We build three Gaia mock catalogues of HVSs anchored to current observations, exploring different ejection mechanisms and GC stellar population properties. In all cases, we predict hundreds to thousands of HVSs with precise proper motion measurements within a few tens of kpc from us. For stars with a relative error in total proper motion below $10 \%$, the mass range extends to ~$10 M_{\odot}$ but peaks at ~$1$ $M_\odot$. The majority of Gaia HVSs will therefore probe a different mass and distance range compared to the current non-Gaia sample. In addition, a subset of a few hundreds to a few thousands of HVSs with $M$ ~ $3$ $M_\odot$ will be bright enough to have a precise measurement of the three-dimensional velocity from Gaia alone. Finally, we show that Gaia will provide more precise proper motion measurements for the current sample of HVS candidates. This will help identifying their birthplace narrowing down their ejection location, and confirming or rejecting their nature as HVSs. Overall, our forecasts are extremely encouraging in terms of quantity and quality of HVS data that can be exploited to constrain both the Milky Way potential and the GC properties.Comment: 17 pages, 18 figures, accepted for publication in MNRA

Time-Reversal-Violating Schiff Moment of 199Hg

We calculate the Schiff moment of the nucleus 199Hg, created by pi-N-N vertices that are odd under parity (P) and time-reversal (T). Our approach, formulated in diagrammatic perturbation theory with important core-polarization diagrams summed to all orders, gives a close approximation to the expectation value of the Schiff operator in the odd-A Hartree-Fock-Bogoliubov ground state generated by a Skyrme interaction and a weak P- and T-odd pion-exchange potential. To assess the uncertainty in the results, we carry out the calculation with several Skyrme interactions (the quality of which we test by checking predictions for the isoscalar-E1 strength distribution in 208Pb) and estimate most of the important diagrams we omit.Comment: 13 pages, 7 figure

A influência dos nutrientes do solo na abundância de enquitreídeos (Oligochaeta, Enchytraeidae) em quatro diferentes sistemas de produção em Quitandinha, PR.

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