Biology Commons^™

Acclimation Of Photosynthetic Temperature Optima Of Temperate And Boreal Tree Species In Response To Experimental Forest Warming, Kerrie M. Sendall, Peter B. Reich, Changming Zhao, Hou Jihua, Xia Orong Wei, Artur Stefanski, Karen Rice, Roy L. Rich, Rebecca A. Montgomery

Faculty Research & Creative Activity

Rising temperatures caused by climate change could negatively alter plant ecosystems if temperatures exceed optimal

temperatures for carbon gain. Such changes may threaten temperature-sensitive species, causing local extinctions and

range migrations. This study examined the optimal temperature of net photosynthesis (Topt) of two boreal and four

temperate deciduous tree species grown in the field in northern Minnesota, United States under two contrasting temperature

regimes. We hypothesized that Topt would be higher in temperate than co-occurring boreal species, with

temperate species exhibiting greater plasticity in Topt, resulting in better acclimation to elevated temperatures. The

chamberless experiment, located at two sites in …

Group 3 Late Embryogenesis Abundant Proteins From Embryos Of Artemia Franciscana: Structural Properties And Protective Abilities During Desiccation, Leaf C. Boswell, Michael A. Menze, Steven C. Hand

Faculty Research & Creative Activity

Group 3 late embryogenesis abundant (LEA) proteins are highly

hydrophilic, and their expression is associated with desiccation

tolerance in both plants and animals. Here we show that two

LEA proteins from embryos of Artemia franciscana, AfrLEA2

and AfrLEA3m, are intrinsically disordered in solution but

upon desiccation gain secondary structure, as measured by circular

dichroism. Trifluoroethanol and sodium dodecyl sulfate

are both shown to induce a-helical structure in AfrLEA2 and

AfrLEA3m. Bioinformatic predictions of secondary-structure

content for both proteins correspond most closely to conformations

measured in the dry state. Because some LEA proteins

afford protection to desiccation-sensitive proteins during drying

and …

Cryopreservation Of Hepatocyte (Hepg2) Cell Monolayers: Impact Of Trehalose, Blake Stokich, Quinn Osgood, David Grimm, Shhyam Moorthy, Nilay Chakraborty, Michael A. Menze

Faculty Research & Creative Activity

A simple method to cryogenically preserve hepatocyte monolayers is currently not available but such a technique would facilitate numerous applications in the field of biomedical engineering, cell line development, and drug screening. We investigated the effect of trehalose and dimethyl sulfoxide (Me2SO) in cryopreservation of human hepatocellular carcinoma (HepG2) cells in suspension and monolayer formats. HepG2 cell monolayers were incubated for 24 h at varying concentrations of trehalose (50–150 mM) prior to cryopreservation to identify the optimum concentration for such preincubation. When trehalose alone was used as the cryoprotective agent (CPA), cells in monolayer format did not survive freezing while …

Are U, Ni, And Hg An Environmental Risk Within A Rcra/Cercla Unit On The U.S. Department Of Energy's Savannah River Site?, Paul G. Edwards, Karen F. Gaines, A. Lawrence Bryan Jr., James M. Novak, Susan A. Blas

Faculty Research & Creative Activity

The U.S. Department of Energy's Savannah River Site (SRS) is a former nuclear weapon production facility. From 1954–1985, releases of Al, Cu, Cr, Hg, Ni, Pb, U, and Zn were discharged into the Tims Branch-Steed Pond water system. This study investigates whether metal concentrations in Tims Branch's sediment, biofilm and other biota exceed screening level risk calculations to determine if remedial actions should be pursued for the Contaminants of Potential Concern (U, Ni, Hg). Transfer factors (TFs) were calculated to determine metal concentration changes throughout lower trophic levels and results were compared with sediment benchmarks to create hazard quotients (HQs) …

Trophic Dynamics Of U, Ni, Hg And Other Contaminants Of Potential Concern On The Department Of Energy’S Savannah River Site, Paul G. Edwards, Karen F. Gaines, A. Lawrence Bryan Jr., James M. Novak, Susan A. Blas

Faculty Research & Creative Activity

The Department of Energy’s Savannah River Site is a former nuclear weapon material production and current research facility located in South Carolina, USA. Wastewater discharges from a fuel and nuclear reactor target manufacturing facility released depleted and natural U, as well as other metals into the Tims Branch- Steed Pond water system. We investigated the current dynamics of this system for the purposes of environmental monitoring and assessment by examining metal concentrations, bioavailability, and trophic transfer of contaminants in seven ponds. Biofilm, detritus, and Anuran and Anisopteran larvae were collected and analyzed for stable isotopes (δ15N, δ13C) and contaminants of …

Genetic Engineering, A Hope For Sustainable Biofuel Production: Review, Sudip Paudel, Michael A. Menze

Faculty Research & Creative Activity

The use of recently developed genetic engineering tools in combination with organisms that have the potential to produce precursors for the production of biodiesel, promises a sustainable and environment friendly energy source. Enhanced lipid production in wild type and/or genetically engineered organisms can offer sufficient raw material for industrial transesterification of plant-based triglycerides. Bio-diesel, produced with the help of genetically modified organisms, might be one of the best alternatives to fossil fuels and to mitigate various environmental hazards.

Toxicodynamic Modeling Of 137cs To Estimate White-Tailed Deer Background Levels For The Department Of Energy's Savannah River Site, Karen F. Gaines, James M. Novak, Christopher W. Bobryk, Susan A. Blas

Faculty Research & Creative Activity

The U.S. Department of Energy's (USDOE) Savannah River Site (SRS) is a former nuclear weapon material production and current research facility adjacent to the Savannah River in South Carolina, USA. The purpose of this study was to determine the background radiocesium (137Cs) body burden (e.g., from global fallout) for white-tailed deer (Odocoileus virginianus) inhabiting the SRS. To differentiate what the background burden is for the SRS versus 137Cs obtained from SRS nuclear activities, data were analyzed spatially, temporally and compared to other off-site hunting areas near the SRS. The specific objectives of this study were: to compare SRS and offsite …