142 research outputs found

    The Role of Aqueous Thin Film Evaporative Cooling on Rates of Elemental Mercury Air-Water Exchange Under Temperature Disequilibrium Conditions

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    Proceedings of the 2001 Georgia Water Resources Conference, April 26 and 27, 2001, Athens, Georgia.Numerous technical studies have demonstrated that vapor phase air-water exchange of a number of toxicants including elemental mercury display a diel cycle. Specifically, daytime rates of air-water exchange can exceed nighttime values by 33 to 300% (e.g. see references cited in Loux, 2000 and Loux, 2001). Loux (2001) illustrated that while diel water column elemental mercury concentration cycles may tend to be the dominant factor in observed diel cycles in elemental mercury air-water exchange rates, the effect of diel cycles in temperature disequilibrium between the atmosphere and underlying waters also may be significant.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors

    Issues in Assessing Environmental Exposures to Manufactured Nanomaterials

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    Manufactured nanomaterials (MNs) are commonly considered to be commercial products possessing at least one dimension in the size range of 10−9 m to 10−7 m. As particles in this size range represent the smaller fraction of colloidal particles characterized by dimensions of 10−9 m to 10−6 m, they differ from both molecular species and bulk particulate matter in the sense that they are unlikely to exhibit significant settling under normal gravitational conditions and they are also likely to exhibit significantly diminished diffusivities (when compared to truly dissolved species) in environmental media. As air/water, air/soil, and water/soil intermedium transport is governed by diffusive processes in the absence of significant gravitational and inertial impaction processes in environmental systems, models of MN environmental intermedium transport behavior will likely require an emphasis on kinetic approaches. This review focuses on the likely environmental fate and transport of MNs in atmospheric and aquatic systems. Should significant atmospheric MNs emission occur, previous observations suggest that MNs may likely exhibit an atmospheric residence time of ten to twenty days. Moreover, while atmospheric MN aggregates in a size range of 10−7 m to 10−6 m will likely be most mobile, they are least likely to deposit in the human respiratory system. An examination of various procedures including the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal particle suspension stability in water indicates that more sophisticated approaches may be necessary in order to develop aquatic exposure models of acceptable uncertainty. In addition, concepts such as Critical Coagulation Concentrations and Critical Zeta Potentials may prove to be quite useful in environmental aquatic exposure assessments

    Evaluating Herbicides for the Control of Multiflora Rose and Autumn Olive in Eastern Ohio

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    Invasive plants cause billions of dollars annually in damage, displace desirable plants, and reduce available land area for livestock grazing. Multiflora rose and autumn olive are two such species prevalent across the Eastern United States. Originally introduced for livestock containment and erosion control, these plants have become widespread, resulting in reduced animal grazing. The Eastern Agricultural Research Station (EARS) is located in Southeast Ohio and is owned by The Ohio State University. Much of the more than 2,000 acres has a history of surface mining and was reclaimed with the planting of multiflora rose and autumn olive. These plants have invaded significant portions of the property and have reduced land available to support the commercial beef research herd. Our study included a replicated trial of multiflora rose and autumn olive plants. We categorized plants into small and medium/large sizes across the study area. Six herbicide treatments were applied to plants using a handheld sprayer. Herbicide treatments were applied randomly in August and an assessment was completed approximately six weeks to rate effectiveness of the applications as compared to the control plants. There were four replicates per treatment. The initial results of the first year of the study indicate each of the products tested provided acceptable control of the treated plants

    The HMGB1/RAGE inflammatory pathway promotes pancreatic tumor growth by regulating mitochondrial bioenergetics

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    Tumor cells require increased adenosine triphosphate (ATP) to support anabolism and proliferation. The precise mechanisms regulating this process in tumor cells are unknown. Here, we show that the receptor for advanced glycation endproducts (RAGE) and one of its primary ligands, high-mobility group box 1 (HMGB1), are required for optimal mitochondrial function within tumors. We found that RAGE is present in the mitochondria of cultured tumor cells as well as primary tumors. RAGE and HMGB1 coordinately enhanced tumor cell mitochondrial complex I activity, ATP production, tumor cell proliferation and migration. Lack of RAGE or inhibition of HMGB1 release diminished ATP production and slowed tumor growth in vitro and in vivo. These findings link, for the first time, the HMGB1-RAGE pathway with changes in bioenergetics. Moreover, our observations provide a novel mechanism within the tumor microenvironment by which necrosis and inflammation promote tumor progression

    Emergency Medical Services (EMS) Activities Funded by the Medicare Rural Hospital Flexibility Program

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    Since the first full year of Flex Program funding, the number and range of EMS improvement activities proposed by participating facilities has increased substantially. This report describes the EMS-related projects that states proposed to conduct in fiscal year 2004-2005

    Intrauterine Blood Plasma Platelet-Therapy Mitigates Persistent Breeding-Induced Endometritis, Reduces Uterine Infections, and Improves Embryo Recovery in Mares

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    Microorganisms, including pathogenic or opportunistic bacteria and fungi, may gain access to the uterus during breeding, and infectious endometritis plays a major role in equine subfertility. This study aimed to assess the post-breeding inflammatory response, endometrial culture, and embryo recovery of mares susceptible to persistent breeding-induced endometritis (PBIE) treated with plasma-rich (PRP) or -poor (PPP) plasma. Mares (n = 12) susceptible to PBIE had three cycles randomly assigned to receive intrauterine infusions of lactate ringer solution (LRS, control), or autologous PRP or PPP pre- (−48 and −24 h) and post-breeding (6 and 24 h). Mares were bred with fresh semen from one stallion. Intrauterine fluid accumulation (IUF) and endometrial neutrophils were assessed every 24 h up to 96 h post-breeding. Uterine cytokines (Ilβ, IL6, CXCL8, and IL10) were evaluated before (0 h), 6, and 24 h post-breeding, and endometrial culture three and nine days after breed. Embryo flushing was performed 8 days post-ovulation. Data were analyzed with mixed model, Tukey’s post-hoc test, and multivariate regression. PRP treatment reduced endometrial neutrophils, post-breeding IUF, and pro-inflammatory cytokines when compared to control-assigned cycles, but not significantly different than PPP. Controls had a significantly higher percentage of positive bacterial cultures (33%) in comparison to PRP-assigned cycles (0%), whereas cycles treated with PPP were not significantly different from the other groups (25%). The PRP-assigned cycles had significantly greater embryo recovery rates (83%) than the control (33%), though not significantly different than PPP (60%). Plasma infusion reduced the duration and intensity of the post-breeding inflammatory response and improved embryo recovery in mares susceptible to PBIE. Platelets incrementally downregulate PBIE and appear to have a dose-dependent antimicrobial property
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