Nutrient Concentrations in the Scioto River and the Relative Importance to the Problem of Hypoxia in the Gulf of Mexico

Nutrients from the Mississippi-Atchafalaya River Basin have been found to be a principal cause of the hypoxic zone that forms every spring and summer on the Louisiana-Texas continental shelf in the northern Gulf of Mexico. Water that has less than 2 mg/l of dissolved oxygen content is referred to as hypoxic. The low levels of oxygen cause stress and can prove to be lethal to immobile bottom-dwelling species, thus altering the food chain and energy relationships. The hypoxic zone has been growing since it first mapped. Fertilizers applied in agricultural lands are the primary source of nutrients that contribute to hypoxia. The Mississippi River Basin drains some of the most productive, and most fertilized, agricultural land in the world. The goals of this study are to 1) gain a better understanding about the problem of hypoxia in general 2) investigate the relative importance of the different sources of nutrients and the contributions of sub basins in the Mississippi River Basin and to 3) examine available data in the Upper Scioto River Basin to assess it's contribution of nutrients and identify trends of nutrient concentrations. This thesis is divided into five chapters. Section 2 presents an overview of nutrient chemistry, sources, and different factors that govern nutrient loading in streams, with an emphasis on agricultural settings. Section 3 describes the problem of hypoxia in the northern Gulf of Mexico and the factors that control its year-to-year extent. Section 4 examines the Scioto River Basin and nutrient data from Griggs and O'Shaughnessy Reservoirs, which are feed by the Scioto River near Columbus Ohio. These data sets were taken monthly over a 15-year period and provides the basis to understand the local contribution to the hypoxic zone, suggest factors that control nutrient concentrations in the Scioto River, and to understand the trends in nutrient levels near Columbus, Ohio. Section 5 summarizes the major conclusions of the study

Detection of cytokine protein expression in mouse lung homogenates using suspension bead array

BACKGROUND: The objective for this present study was to determine whether or not suspension bead array is a feasible method to detect changes in cytokine protein expression in mouse lung tissue homogenates. Here, we report on suspension bead array as a feasible method for detection of lipopolysaccharide (LPS)-evoked changes in cytokine protein expression in mouse lung tissue homogenates. MATERIALS AND METHODS: Mice were treated (0.2 ml, intraperitoneal, i.p.) with phosphate buffered saline (PBS) or LPS (0.25 mg/ml) and sacrificed at either 2- or 24-hours post treatment. Formalin-fixed and paraffin-embedded lung sections were evaluated by light microscopy. Flash frozen lung tissues were homogenized for measurement of various cytokine protein expression levels using suspension bead array, antibody array and ELISA. Comparison between groups was performed using a Wilcoxon signed rank test. RESULTS: Pulmonary perivascular edema and an accumulation of mixed cell infiltrates within blood and lymphatic vessels, as well as in the adjacent interstitium, were present at both 2- and 24-hours following LPS treatment. A minimal increase in the number of alveolar macrophages was also observed in the 24-hour LPS-treated mice only. The suspension bead array assay revealed statistically significant increases in mouse lung tissue homogenate levels of interleukin-6 (IL-6) and granulocyte/macrophage colony-stimulating factor (GM-CSF) proteins and a decrease in IL-2 protein at 24-hours post LPS-treatment only. Similar cytokine protein expression patterns were observed using antibody array. Significantly increased IL-6 protein expression levels were also detected using ELISA, which correlated with the suspension bead array data. CONCLUSION: The present study shows that suspension bead array is a feasible method to detect changes in cytokine protein expression in mouse lung tissue homogenates

Police stress and teacher stress at work and at home

This study compared police officers and teachers in three communities--which varied in size, geographical location, and economic base--for differences in perceived occupational stress and for differences in the patterns of perceived job stress, perceived nonjob stress, and both perceived job and life stressors. For police officers, higher levels of job stress were associated with higher levels on measures of perceived job stressors. This relationship varied from city to city, with the relationship holding for the city in which both police operations and school operations were relatively normal, with no difference between police and teachers in the city in which the school administration was in conflict with its employees, and with a reversal in the city in which the police administration was noted for its excellent management skills.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29609/1/0000698.pd

Germline Met Mutations in Mice Reveal Mutation- and Background-Associated Differences in Tumor Profiles

BACKGROUND: The receptor tyrosine kinase Met is involved in the progression and metastasis of numerous human cancers. Although overexpression and autocrine activation of the Met signaling pathway are commonly found in human cancers, mutational activation of Met has been observed in small cell and non-small cell lung cancers, lung adenocarcinomas, renal carcinomas, and mesotheliomas. METHODOLOGY/PRINCIPAL FINDINGS: To investigate the influence of mutationally activated Met in tumorigenesis, we utilized a novel mouse model. Previously, we observed that various Met mutations developed unique mutation-specific tumor spectra on a C57BL/6 background. Here, we assessed the effect of genetic background on the tumorigenic potential of mutationally activated Met. For this purpose, we created congenic knock-in lines of the Met mutations D1226N, M1248T, and Y1228C on the FVB/N background. Consistent with the mutation-specific tumor spectra, several of the mutations were associated with the same tumor types as observed on C57BL/6 background. However, on the FVB/N background most developed a high incidence of mammary carcinomas with diverse histopathologies. CONCLUSIONS/SIGNIFICANCE: This study demonstrates that on two distinct mouse backgrounds, Met is able to initiate tumorigenesis in multiple cell types, including epithelial, hematopoietic, and endothelial. Furthermore, these observations emphasize that even a modest increase in Met activation can initiate tumorigenesis with both the Met mutational spectra and host background having profound influence on the type of tumor generated. Greater insight into the interaction of genetic modifiers and Met signaling will significantly enhance our ability to tailor combination therapies for Met-driven cancers

Isotopic signals in an agricultural watershed suggest denitrification is locally intensive in riparian areas but extensive in upland soils

© The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Sigler, W. A., Ewing, S. A., Wankel, S. D., Jones, C. A., Leuthold, S., Brookshire, E. N. J., & Payn, R. A. Isotopic signals in an agricultural watershed suggest denitrification is locally intensive in riparian areas but extensive in upland soils. Biogeochemistry, 158, (2022): 251–268, https://doi.org/10.1007/s10533-022-00898-9.Nitrogen loss from cultivated soils threatens the economic and environmental sustainability of agriculture. Nitrate (NO3−) derived from nitrification of nitrogen fertilizer and ammonified soil organic nitrogen may be lost from soils via denitrification, producing dinitrogen gas (N2) or the greenhouse gas nitrous oxide (N2O). Nitrate that accumulates in soils is also subject to leaching loss, which can degrade water quality and make NO3− available for downstream denitrification. Here we use patterns in the isotopic composition of NO3− observed from 2012 to 2017 to characterize N loss to denitrification within soils, groundwater, and stream riparian corridors of a non-irrigated agroecosystem in the northern Great Plains (Judith River Watershed, Montana, USA). We find evidence for denitrification across these domains, expressed as a positive linear relationship between δ15N and δ18O values of NO3−, as well as increasing δ15N values with decreasing NO3− concentration. In soils, isotopic evidence of denitrification was present during fallow periods (no crop growing), despite net accumulation of NO3− from the nitrification of ammonified soil organic nitrogen. We combine previous results for soil NO3− mass balance with δ15N mass balance to estimate denitrification rates in soil relative to groundwater and streams. Substantial denitrification from soils during fallow periods may be masked by nitrification of ammonified soil organic nitrogen, representing a hidden loss of soil organic nitrogen and an under-quantified flux of N to the atmosphere. Globally, cultivated land spends ca. 50% of time in a fallow condition; denitrification in fallow soils may be an overlooked but globally significant source of agricultural N2O emissions, which must be reduced along-side other emissions to meet Paris Agreement goals for slowing global temperature increase.National Institute of Food and Agriculture, 2011–51130-31121, S. A. Ewing, 2011, S. A. Ewing, 2016–67026-25067, S. A. Ewing, Montana State University Extension, Montana Fertilizer Advisory Committee, Montana Agricultural Experiment Station, Montana State University Vice President of Research, Montana State University College of Agriculture, Montana Institute on Ecosystems, NSF EPSCoR, OIA-1757351, S. A. Ewing, OIA-1443108, S. A. Ewing, EPS-110134, S. A. Ewing

Linguistics

Contains table of contents for Section 4, an introduction and abstracts on seven doctoral dissertations

Myeloid Cell Tissue Factor Does Not Contribute to Venous Thrombogenesis in an Electolytic Injury Model

Tissue factor (TF) is a potent initiator of the extrinsic coagulation cascade. The role and source of TF in venous thrombotic disease is not clearly defined. Our study objective was to identify the contribution of myeloid cell TF to venous thrombogenesis in mice

A highly invasive human glioblastoma pre-clinical model for testing therapeutics

Animal models greatly facilitate understanding of cancer and importantly, serve pre-clinically for evaluating potential anti-cancer therapies. We developed an invasive orthotopic human glioblastoma multiforme (GBM) mouse model that enables real-time tumor ultrasound imaging and pre-clinical evaluation of anti-neoplastic drugs such as 17-(allylamino)-17-demethoxy geldanamycin (17AAG). Clinically, GBM metastasis rarely happen, but unexpectedly most human GBM tumor cell lines intrinsically possess metastatic potential. We used an experimental lung metastasis assay (ELM) to enrich for metastatic cells and three of four commonly used GBM lines were highly metastatic after repeated ELM selection (M2). These GBM-M2 lines grew more aggressively orthotopically and all showed dramatic multifold increases in IL6, IL8, MCP-1 and GM-CSF expression, cytokines and factors that are associated with GBM and poor prognosis. DBM2 cells, which were derived from the DBTRG-05MG cell line were used to test the efficacy of 17AAG for treatment of intracranial tumors. The DMB2 orthotopic xenografts form highly invasive tumors with areas of central necrosis, vascular hyperplasia and intracranial dissemination. In addition, the orthotopic tumors caused osteolysis and the skull opening correlated to the tumor size, permitting the use of real-time ultrasound imaging to evaluate antitumor drug activity. We show that 17AAG significantly inhibits DBM2 tumor growth with significant drug responses in subcutaneous, lung and orthotopic tumor locations. This model has multiple unique features for investigating the pathobiology of intracranial tumor growth and for monitoring systemic and intracranial responses to antitumor agents