Effect of Increasing Nitrogen Deposition on Soil Microbial Communities

Increasing nitrogen deposition, increasing atmospheric CO2, and decreasing biodiversity are three main environmental changes occurring on a global scale. The BioCON (Biodiversity, CO2, and Nitrogen) ecological experiment site at the University of Minnesota's Cedar Creek Ecosystem Science Reserve started in 1997, to better understand how these changes would affect soil systems. To understand how increasing nitrogen deposition affects the microbial community diversity, heterogeneity, and functional structure impact soil microbial communities, 12 samples were collected from the BioCON plots in which nitrogenous fertilizer was added to simulate the effect of increasing nitrogen deposition and 12 samples from without added fertilizer. DNA from the 24 samples was extracted using a freeze-grind protocol, amplified, labeled with a fluorescent dye, and then hybridized to GeoChip, a functional gene array containing probes for genes involved in N, S and C cycling, metal resistance and organic contaminant degradation. Detrended correspondence analysis (DCA) of all genes detected was performed to analyze microbial community patterns. The first two axes accounted for 23.5percent of the total variation. The samples fell into two major groups: fertilized and non-fertilized, suggesting that nitrogenous fertilizer had a significant impact on soil microbial community structure and diversity. The functional gene numbers detected in fertilized …
Date: May 17, 2010
Creator: Xiao, Shengmu; Xue, Kai; He, Zhili; VanNostrand, Joy D.; Liu, Jianshe; Hobbie, Sarah E. et al.
System: The UNT Digital Library

Reference set of regulons in Desulfovibrionales inferred by comparative genomics approach

in this study, we carried out large-scale comparative genomics analysis of regulatory interactions in Desulfovibrio vulgaris and 12 related genomes from Desulfovibrionales order using our recently developed web server RegPredict (http://regpredict.lbl.gov). An overall reference collection of 26 Desulfovibrionales regulogs can be accessed through RegPrecise database (http://regpredict.lbl.gov).
Date: November 15, 2010
Creator: Kazakov, Alexey E.; Rodionov, Dmitry A.; Price, Morgan N.; Arkin, Adam P.; Dubchak, Inna & Novichkov, Pavel S.
System: The UNT Digital Library

In silico discovery of the dormancy regulons in a number of Actinobacteria genomes

Mycobacterium tuberculosis is a dangerous Actinobacteria infecting nearly one third of the human population. It becomes dormant and phenotypically drug resistant in response to stresses. An important feature of the M. tuberculosis pathogenesis is the prevalence of latent infection without disease, making understanding of the mechanisms used by the bacteria to exist in this state and to switch to metabolically active infectious form a vital problem to consider. M. tuberculosis dormancy is regulated by the three-component regulatory system of two kinases (DosT and DevS) and transcriprional regulator (DevR). DevR activates transcription of a set of genes, which allow the bacteria to survive long periods of anaerobiosis, and may be important for long-term survival within the host during latent infection. The DevR-regulon is studied experimentally in M. tuberculosis and few other phylogenetically close Mycobacteria spp. As many other two-component systems, the devRS operon is autoregulated. However, the mechanism of the dormancy is not completely clear even for these bacteria and there is no data describing the dormancy regulons in other species.
Date: November 16, 2010
Creator: Gerasimova, Anna; Dubchak, Inna; Arkin, Adam & Gelfand, Mikhail
System: The UNT Digital Library

Investigation of the carbon dioxide sorption capacity and structural deformation of coal

Due to increasing atmospheric CO2 concentrations causing the global energy and environmental crises, geological sequestration of carbon dioxide is now being actively considered as an attractive option to mitigate greenhouse gas emissions. One of the important strategies is to use deep unminable coal seams, for those generally contain significant quantities of coal bed methane that can be recovered by CO2 injection through enhanced coal bed natural gas production, as a method to safely store CO2. It has been well known that the adsorbing CO2 molecules introduce structural deformation, such as distortion, shrinkage, or swelling, of the adsorbent of coal organic matrix. The accurate investigations of CO2 sorption capacity as well as of adsorption behavior need to be performed under the conditions that coals deform. The U.S. Department of Energy-National Energy Technology Laboratory and Regional University Alliance are conducting carbon dioxide sorption isotherm experiments by using manometric analysis method for estimation of CO2 sorption capacity of various coal samples and are constructing a gravimetric apparatus which has a visual window cell. The gravimetric apparatus improves the accuracy of carbon dioxide sorption capacity and provides feasibility for the observation of structural deformation of coal sample while carbon dioxide molecules interact with coal …
Date: January 1, 2010
Creator: Hur, Tae-Bong; Fazio, James; Romanov, Vyacheslav & Harbert, William
System: The UNT Digital Library

2011 DOE Occupational Radiation Exposure Summary poster

This poster graphically presents data pertaining to occupational radiation exposure in terms of total effective dose (TED), primarily, but also collective dose and average measureable dose.
Date: December 12, 2012
Creator: Oak Ridge Associated Universities
System: The UNT Digital Library

Analysis of a US Department of Energy Emergent Technologies Cohort

As a major user of engineered nanoparticles, the U.S. Department of Energy (DOE) uses various methods to monitor the health of emergent technologies workers (ETW) who handle or could potentially be exposed to unbound engineered nanoparticles (UNP). Using data from DOE’s Illness and Injury Surveillance Program (IISP), Oak Ridge Associated Universities (ORAU) created a registry of ETWs. IISP currently tracks 125,000 workers at 14 DOE facilities. Workers in IISP, who were classified as ETWs, were placed in a separate database using Microsoft Access. Using SAS (Version 9.2; Cary, NC), the health status of this cohort was analyzed by a variety of different variables such as age, gender, occupation, years of employment, number of years classified as an ETW, and site.
Date: December 12, 2012
Creator: Strader, Cliff; Ellis, Elizabeth; Barrie, Martin D; Tankersley, William & Wallace, Phil
System: The UNT Digital Library

Rapid Field Measurement of Dissolved Inorganic Carbon Based on CO{sub 2} Analysis

Dissolved inorganic carbon (DIC) is commonly measured in water and is an important parameter for understanding carbonate equilibrium, carbon cycling, and water-rock interaction. While accurate measurements can be made in the analytical laboratory, we have developed a rapid, portable technique that can be used to obtain accurate and precise data in the field as well.
Date: January 1, 2012
Creator: VESPER, DJ, Edenborn, Harry
System: The UNT Digital Library

Hydrogel Tracer Beads: The Development, Modification, and Testing of an Innovative Tracer for Better Understanding LNAPL Transport in Karst Aquifers

The goal of this specific research task is to develop proxy tracers that mimic contaminant movement to better understand and predict contaminant fate and transport in karst aquifers. Hydrogel tracer beads are transported as a separate phase than water and can used as a proxy tracer to mimic the transport of non-aqueous phase liquids (NAPL). They can be constructed with different densities, sizes & chemical attributes. This poster describes the creation and optimization of the beads and the field testing of buoyant beads, including sampling, tracer analysis, and quantitative analysis. The buoyant beads are transported ahead of the dissolved solutes, suggesting that light NAPL (LNAPL) transport in karst may occur faster than predicted from traditional tracing techniques. The hydrogel beads were successful in illustrating this enhanced transport.
Date: January 1, 2012
Creator: Amanda Laskoskie, Harry M. Edenborn, and Dorothy J. Vesper
System: The UNT Digital Library

Anisotropic Flow in the Forward Directions

The STAR Forward TPCs (FTPCs) extend the STAR acceptance for charged particles into the region 2.5 < |eta| < 4.0. We see the first signal of directed flow (v{sub 1}) at RHIC energies. While v{sub 1} is consistent with zero in the central rapidity region it rises up to 2 percent at pseudorapidities of +-4. With this signal we can verify that elliptic flow (v{sub 2}) is in-plane. The measurement of v{sub 2} in the FTPCs confirms the falloff by a factor of about 2 compared to mid-rapidity previously seen by PHOBOS [1]. In addition we look for higher harmonics (v{sub n}, n>2) where in the case of v{sub 4} a signal is seen in the STAR TPC. With the available statistics for the FTPCs we give an upper limit for these harmonics, since the results agree with zero within the errors. However, the falloff of v{sub 4} from mid-rapidity to forward-rapidities appears to be faster than for v{sub 2}.[1] B.B. Back. Phys. Rev. Lett. 89, 222301 (2002)
Date: March 9, 2004
Creator: Oldenburg, Markus D. & Putschke, Jorn
System: The UNT Digital Library