101 research outputs found
Determining the fate and toxicity of polycyclic aromatic hydrocarbons associated with coal-tar and other carbonaceous material particles in urban lakes
U.S. Department of the InteriorU.S. Geological SurveyOpe
Effect of soil on the mutagenic properties of waste water
The disposal of complex mixtures such as waste water on agricultural lands poses known and unknown environmental risks. Mutagens may be introduced into the eco-system and perhaps concentrated by crop plants or leached into ground water supplies. The purpose of this study was to determine the biological effect of a mutagenic waste water before and after application to soil. We used an XAD-8 methanol extract of waste water from the municipal sewage treatment facility at Sauget IL. This extract was a potent direct acting mutagen when assayed with the Salmonella typhimurium. 1 and 3 ml of extract were brought up to 10 ml volumes with water and added to 10 a of sterile or nonsterile , native clay loam. These mixtures were placed in a shaking water bath at room temperature for 0, 24, and 48 h. After separation of solid and liquid portions by filtration, dichloromethane was added to extract the organic fractions from each component. Solvent extractions were evaporated to dryness under vacuum and brought up in DMSO. Tests for mutagenic activity were conducted using strain TA98. After addition to the soil for greater periods of time the mutagenic activity decreased. The solid component exhibited greater mutagenic activity than the liquid. The XAD-8 extract was also assayed using the yg2 assay in Zea mays and the micronucleus assay in Tradescantia. The extract did not induce mutation or chromosome aberrations in these assays. The sludge from the Sauqet plant was chemically fractionated and assayed with S. typhimurium strains TA98 and TA100. The neutral fraction was the most mutagenic fraction followed by the weak acid,-strong acid and basic fractions. These chemical fractions uncovered more mutagenic potency than was predicted by assaying a crude organic extract of the sludge.U.S. Department of the InteriorU.S. Geological SurveyOpe
Development of a Method to Identify Antioxidant Chemical Fractions Isolated From Waste Products of Commercial Corn-Based Ethanol
This final report documents the results from our WMRC seed grant to develop a rapid, quantitative assay to measure the antioxidant capacity of chemical fractions of com distillate solids (CDS). CDS is the primary by-product of commercial com-based ethanol. We are searching for value-added products from the by-products of industrial com processing. The research was done in 2002, although the report was published in 2015. ISTC was formerly the Illinois Waste Management and Research Center (WMRC).WMRC Sponsored Research ProgramOpe
Some Empirical Evidence on the Impact of the AICPA’s Mandatory Continuing Education Requirements
Independent evaluation of a simple clinical prediction rule to identify right ventricular dysfunction in patients with shortness of breath
BACKGROUND:
Many patients have unexplained persistent dyspnea after negative computed tomographic pulmonary angiography (CTPA). We hypothesized that many of these patients have isolated right ventricular (RV) dysfunction from treatable causes. We previously derived a clinical decision rule (CDR) for predicting RV dysfunction consisting of persistent dyspnea and normal CTPA, finding that 53% of CDR-positive patients had isolated RV dysfunction. Our goal is to validate this previously derived CDR by measuring the prevalence of RV dysfunction and outcomes in dyspneic emergency department patients.
METHODS:
A secondary analysis of a prospective observational multicenter study that enrolled patients presenting with suspected PE was performed. We included patients with persistent dyspnea, a nonsignificant CTPA, and formal echo performed. Right ventricular dysfunction was defined as RV hypokinesis and/or dilation with or without moderate to severe tricuspid regurgitation.
RESULTS:
A total of 7940 patients were enrolled. Two thousand six hundred sixteen patients were analyzed after excluding patients without persistent dyspnea and those with a significant finding on CTPA. One hundred ninety eight patients had echocardiography performed as standard care. Of those, 19% (95% confidence interval [CI], 14%-25%) and 33% (95% CI, 25%-42%) exhibited RV dysfunction and isolated RV dysfunction, respectively. Patients with isolated RV dysfunction or overload were more likely than those without RV dysfunction to have a return visit to the emergency department within 45 days for the same complaint (39% vs 18%; 95% CI of the difference, 4%-38%).
CONCLUSION:
This simple clinical prediction rule predicted a 33% prevalence of isolated RV dysfunction or overload. Patients with isolated RV dysfunction had higher recidivism rates and a trend toward worse outcomes
Obituary for Tamara Grummt
Tamara Grummt passed away on January 26, 2020 in Oelsnitz/Vogtland, Germany. Tamara was one of the scientific pioneers in the field of environmental toxicology, namely genotoxicity and hygiene of drinking and bathing waters. Her passing is not only a great loss to environmental research and to the global environmental toxicology community—we have lost an outstanding personality with the heart in the right place, who has become, for many of us, a wonderful friend
Another intermediate mass black hole in a starburst galaxy?: The luminous X-ray source in NGC 3628 reappears
In a 52 ks-long Chandra ACIS-S observation of the nearby starburst galaxy NGC
3628, obtained to study the starburst-driven outflow from this galaxy, we have
detected a very luminous (L_X = 1.1e40 erg/s in the 0.3-8.0 keV energy band)
point source located at least 20 arcsec (~970 pc) from the nucleus of the
galaxy. No radio, optical or near-IR counterpart to this source has been found.
This is most probably the reappearance of the strongly-variable
X-ray-luminous source discovered by Dahlem et al (1995), which faded by a
factor >27 between December 1991 and March 1994 (at which point it had faded
below the detection limit in a ROSAT HRI observation). This source is clearly a
member of an enigmatic class of X-ray sources that are considerably more
luminous than conventional X-ray binaries but less luminous than AGN, and which
are not found at the dynamical center of the host galaxy.
The Chandra spectrum is best-fit by an absorbed power law model with a photon
index of Gamma = 1.8+/-0.2, similar to that seen in Galactic BH binary
candidates in their hard state. Bremsstrahlung models or multi-color disk
models (the favored spectral model for objects in this class based on ASCA
observations) can provide statistically acceptable fits only if the data at
energies E > 5 keV is ignored. This is one of the first X-ray spectra of such
an object that is unambiguously that of the source alone, free from the
spectral contamination by X-ray emission from the rest of the galaxy that
affects previous spectral studies of these objects using ASCA.Comment: Accepted for publication in the Ap
Catching Element Formation In The Act
Gamma-ray astronomy explores the most energetic photons in nature to address
some of the most pressing puzzles in contemporary astrophysics. It encompasses
a wide range of objects and phenomena: stars, supernovae, novae, neutron stars,
stellar-mass black holes, nucleosynthesis, the interstellar medium, cosmic rays
and relativistic-particle acceleration, and the evolution of galaxies. MeV
gamma-rays provide a unique probe of nuclear processes in astronomy, directly
measuring radioactive decay, nuclear de-excitation, and positron annihilation.
The substantial information carried by gamma-ray photons allows us to see
deeper into these objects, the bulk of the power is often emitted at gamma-ray
energies, and radioactivity provides a natural physical clock that adds unique
information. New science will be driven by time-domain population studies at
gamma-ray energies. This science is enabled by next-generation gamma-ray
instruments with one to two orders of magnitude better sensitivity, larger sky
coverage, and faster cadence than all previous gamma-ray instruments. This
transformative capability permits: (a) the accurate identification of the
gamma-ray emitting objects and correlations with observations taken at other
wavelengths and with other messengers; (b) construction of new gamma-ray maps
of the Milky Way and other nearby galaxies where extended regions are
distinguished from point sources; and (c) considerable serendipitous science of
scarce events -- nearby neutron star mergers, for example. Advances in
technology push the performance of new gamma-ray instruments to address a wide
set of astrophysical questions.Comment: 14 pages including 3 figure
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