Summary of Toxicological Data for Aquatic Organisms of Illinois

The data presented in this report contain Information on toxicity testing performed on organisms that could be found In aquatic habitats in Illinois. To compile this information a thorough list of all aquatic organisms in Illinois was required. This was constructed through literature searches and personal communication with scientists who collect and identify Illinois aquatic specimens. Each species name was used to search a database which contained toxicity information on aquatic organisms. No toxicological Information was found for many Illinois species. For most organisms, all available information retrieved from the database is presented. For species on which extensive toxicological research has been performed, data showing 96 hour LC50 or EC50 values and chronic testing values constitute the bulk of the records. In addition to records detailing toxicity values and experimental conditions, a list of tested chemical compounds and organisms is included. Literature citing observations and identification of aquatic organisms within Illinois was the most valuable resource in compiling a list of Illinois aquatic species. Staff of the Illinois Natural History Survey were helpful in recommending the most useful publications, making available their own field lists, and helping to update taxonomy and nomenclature from older reports. In particular we would like to acknowledge Don Webb, Larry Page, Warren Brigham, Mark Wetzel, Kevin Cummings, and Allison Brigham from the INHS Faunistics section and Michael Henebry from the section of Aquatic Biology. To retrieve toxicity data on the aquatic organisms of Illinois, a Chemical Information System, Inc. database, AQUIRE (Aquatic Information Retrieval System), was employed. AQUIRE contains data extracted from publications dealing with the toxic effects of chemical substances on aquatic organisms. Each Latin species name from the compiled Illinois list was used to search records in the database. If AQUIRE matched a record with the species name, the record was stored. If there were an excessive number of matching records, the search was narrowed by specifying particular regimens and/or effective endpoint types. Ultimately a printout of the records pertaining to each organism was produced. The data contained In this report are duplications of the AQUIRE records obtained for Illinois organisms. The taxonomy, habitat, and Illinois distribution is listed immediately preceding the AQUIRE records compiled for each species. These records have been substantially reduced from their original size and are arranged by chemical compound in alphabetical and/or numerical order.published or submitted for publicationis peer reviewe

The Knudsen temperature jump and the Navier-Stokes hydrodynamics of granular gases driven by thermal walls

Thermal wall is a convenient idealization of a rapidly vibrating plate used for vibrofluidization of granular materials. The objective of this work is to incorporate the Knudsen temperature jump at thermal wall in the Navier-Stokes hydrodynamic modeling of dilute granular gases of monodisperse particles that collide nearly elastically. The Knudsen temperature jump manifests itself as an additional term, proportional to the temperature gradient, in the boundary condition for the temperature. Up to a numerical pre-factor of order unity, this term is known from kinetic theory of elastic gases. We determine the previously unknown numerical pre-factor by measuring, in a series of molecular dynamics (MD) simulations, steady-state temperature profiles of a gas of elastically colliding hard disks, confined between two thermal walls kept at different temperatures, and comparing the results with the predictions of a hydrodynamic calculation employing the modified boundary condition. The modified boundary condition is then applied, without any adjustable parameters, to a hydrodynamic calculation of the temperature profile of a gas of inelastic hard disks driven by a thermal wall. We find the hydrodynamic prediction to be in very good agreement with MD simulations of the same system. The results of this work pave the way to a more accurate hydrodynamic modeling of driven granular gases.Comment: 7 pages, 3 figure

Greenhouse gas balance over thaw-freeze cycles in discontinuous zone permafrost

Peat in the discontinuous permafrost zone contains a globally significant reservoir of carbon that has undergone multiple permafrost-thaw cycles since the end of the mid-Holocene (~3700 years before present). Periods of thaw increase C decomposition rates which leads to the release of CO2 and CH4 to the atmosphere creating potential climate feedback. To determine the magnitude and direction of such feedback, we measured CO2 and CH4 emissions and modeled C accumulation rates and radiative fluxes from measurements of two radioactive tracers with differing lifetimes to describe the C balance of the peatland over multiple permafrost-thaw cycles since the initiation of permafrost at the site. At thaw features, the balance between increased primary production and higher CH4 emission stimulated by warmer temperatures and wetter conditions favors C sequestration and enhanced peat accumulation. Flux measurements suggest that frozen plateaus may intermittently (order of years to decades) act as CO2 sources depending on temperature and net ecosystem respiration rates, but modeling results suggest that—despite brief periods of net C loss to the atmosphere at the initiation of thaw—integrated over millennia, these sites have acted as net C sinks via peat accumulation. In greenhouse gas terms, the transition from frozen permafrost to thawed wetland is accompanied by increasing CO2 uptake that is partially offset by increasing CH4 emissions. In the short-term (decadal time scale) the net effect of this transition is likely enhanced warming via increased radiative C emissions, while in the long-term (centuries) net C deposition provides a negative feedback to climate warming

Weyl's Lagrangian in teleparallel form

The main result of the paper is a new representation for the Weyl Lagrangian (massless Dirac Lagrangian). As the dynamical variable we use the coframe, i.e. an orthonormal tetrad of covector fields. We write down a simple Lagrangian - wedge product of axial torsion with a lightlike element of the coframe - and show that this gives the Weyl Lagrangian up to a nonlinear change of dynamical variable. The advantage of our approach is that it does not require the use of spinors, Pauli matrices or covariant differentiation. The only geometric concepts we use are those of a metric, differential form, wedge product and exterior derivative. Our result assigns a variational meaning to the tetrad representation of the Weyl equation suggested by J. B. Griffiths and R. A. Newing

Integrating rich user feedback into intelligent user interfaces

The potential for machine learning systems to improve via a mutually beneficial exchange of information with users has yet to be explored in much detail. Previously, we found that users were willing to provide a generous amount of rich feedback to machine learning systems, and that the types of some of this rich feedback seem promising for assimilation by machine learning algorithms. Following up on those findings, we ran an experiment to assess the viability of incorporating real-time keyword-based feedback in initial training phases when data is limited. We found that rich feedback improved accuracy but an initial unstable period often caused large fluctuations in classifier behavior. Participants were able to give feedback by relying heavily on system communication in order to respond to changes. The results show that in order to benefit from the user’s knowledge, machine learning systems must be able to absorb keyword-based rich feedback in a graceful manner and provide clear explanations of their predictions

Decisive Search for a Diquark-Antidiquark Meson with Hidden Strangeness

Diquark-antidiquark states are expected to exist as a natural complement of mesons and baryons. Although they were predicted long ago, and some candidates were found experimentally, none has, as yet, been reliably identified. We suggest that the search for the so-called $C(1480)$-meson in reactions such as photoproduction $\gamma N\rightarrow\phi\pi N$ and $K N \rightarrow \phi \pi \Lambda$ should provide a decisive way to settle this issue. Estimates of the cross sections are given using present experimental information on the C-meson and assuming its diquark-antidiquark structure. Sizable cross sections are predicted (of the order of 0.1 $\mu$b for photoproduction and of the order of 0.1 mb for $KN$ at the maximum with an insignificant background). Failure to find this kind of signal would imply that the C-meson is {\it not} a diquark-antidiquark state.Comment: 9 pages in LATex + 6 figs. (available from authers upon request), IUHET-269/9

Just how long can you live in a black hole and what can be done about it?

We study the problem of how long a journey within a black hole can last. Based on our observations, we make two conjectures. First, for observers that have entered a black hole from an asymptotic region, we conjecture that the length of their journey within is bounded by a multiple of the future asymptotic ``size'' of the black hole, provided the spacetime is globally hyperbolic and satisfies the dominant-energy and non-negative-pressures conditions. Second, for spacetimes with ${\Bbb R}^3$ Cauchy surfaces (or an appropriate generalization thereof) and satisfying the dominant energy and non-negative-pressures conditions, we conjecture that the length of a journey anywhere within a black hole is again bounded, although here the bound requires a knowledge of the initial data for the gravitational field on a Cauchy surface. We prove these conjectures in the spherically symmetric case. We also prove that there is an upper bound on the lifetimes of observers lying ``deep within'' a black hole, provided the spacetime satisfies the timelike-convergence condition and possesses a maximal Cauchy surface. Further, we investigate whether one can increase the lifetime of an observer that has entered a black hole, e.g., by throwing additional matter into the hole. Lastly, in an appendix, we prove that the surface area $A$ of the event horizon of a black hole in a spherically symmetric spacetime with ADM mass $M_{\text{ADM}}$ is always bounded by $A \le 16\pi M_{\text{ADM}}^2$, provided that future null infinity is complete and the spacetime is globally hyperbolic and satisfies the dominant-energy condition.Comment: 20 pages, REVTeX 3.0, 6 figures included, self-unpackin

The Efroimsky formalism adapted to high-frequency perturbations

The Efroimsky perturbation scheme for consistent treatment of gravitational waves and their influence on the background is summarized and compared with classical Isaacson's high-frequency approach. We demonstrate that the Efroimsky method in its present form is not compatible with the Isaacson limit of high-frequency gravitational waves, and we propose its natural generalization to resolve this drawback.Comment: 7 pages, to appear in Class. Quantum Gra

Why Do They Do It? A Case Study of Factors Influencing Part-Time Faculty to Seek Employment at a Community College

The purpose of this qualitative study was to discover the motivational factors influencing part-time faculty employment within the community college from the perspective of the part-time faculty. The study examined these reported motivational factors for differences influenced by age, gender, and employment status. A survey was distributed to a random sample of part-time faculty members at a large metropolitan community college in the Southeastern United States. Participants were asked to respond to categorical demographic questions and survey questions to determine workplace satisfaction. Three open-ended questions were presented to obtain in-depth information about the motivational factors leading adjunct faculty to seek employment at the community college. Findings reveal that motivation is a result of interest in working within a discipline, working with students, and achieving personal satisfaction