Biological Engineering Commons^™

Adhesion Of Jurkat Cells In Defined Media And Substrates, Sarah De Leo

Honors Capstones

No abstract provided.

Metabolic Engineering Of A Thermophilic Bacterium To Produce Ethanol At High Yield, A. Joe Shaw, Kara K. Podkaminer, Sunil G. Desai, John S. Bardsley, Stephen R. Rogers, Philip G. Thorne, David A. Hogsett, Lee R. Lynd

Dartmouth Scholarship

We report engineering Thermoanaerobacterium saccharolyticum, a thermophilic anaerobic bacterium that ferments xylan and biomass-derived sugars, to produce ethanol at high yield. Knockout of genes involved in organic acid formation (acetate kinase, phosphate acetyltransferase, and L-lactate dehydrogenase) resulted in a strain able to produce ethanol as the only detectable organic product and substantial changes in electron flow relative to the wild type. Ethanol formation in the engineered strain (ALK2) utilizes pyruvate:ferredoxin oxidoreductase with electrons transferred from ferredoxin to NAD(P), a pathway different from that in previously described microbes with a homoethanol fermentation. The homoethanologenic phenotype was stable for >150 generations …

Modeling Electric Fields In Microfluidic Devices, Micah Fincher

Honors Capstones

No abstract provided.

N-Glycan Modification In Aspergillus Species, Elke Kainz, Andreas Gallmetzer, Christian Hatzl, Juergen H. Nett, Huijuan Li, Thorsten Schinko, Robert Pachlinger, Harald Berger, Yazmid Reyes-Dominguez, Andreas Bernreiter, Tillmann Gerngross, Stefan Wildt, Joseph Strauss

Dartmouth Scholarship

The production by filamentous fungi of therapeutic glycoproteins intended for use in mammals is held back by the inherent difference in protein N-glycosylation and by the inability of the fungal cell to modify proteins with mammalian glycosylation structures. Here, we report protein N-glycan engineering in two Aspergillus species. We functionally expressed in the fungal hosts heterologous chimeric fusion proteins containing different localization peptides and catalytic domains. . This strategy allowed the isolation of a strain with a functional -1,2-mannosidase producing increased amounts of N-glycans of the Man 5 GlcNAc 2 type. This strain was further engineered by the introduction of …

Cellulose Utilization By Clostridium Thermocellum: Bioenergetics And Hydrolysis Product Assimilation, Yi-Heng P. Zhang, Lee R. Lynd

Dartmouth Scholarship

The bioenergetics of cellulose utilization by Clostridium thermocellum was investigated. Cell yield and maintenance parameters, Y(X/ATP)True = 16.44 g cell/mol ATP and m = 3.27 mmol ATP/g cell per hour, were obtained from cellobiose-grown chemostats, and it was shown that one ATP is required per glucan transported. Experimentally determined values for G(ATP)P-T (ATP from phosphorolytic beta-glucan cleavage minus ATP for substrate transport, mol ATP/mol hexose) from chemostats fed beta-glucans with degree of polymerization (DP) 2-6 agreed well with the predicted value of (n-2)/n [corrected] (n = mean cellodextrin DP assimilated). A mean G(ATP)(P-T) value of 0.52 +/- 0.06 was calculated …

Validating Surface Energy Balance Fluxes Derived From Airborne Remote Sensing, José Luis Chávez Egüez

Biological Engineering

Remote sensing-derived energy balance components were compared against measured eddy covariance energy balance terms using heat flux source area models to validate the airborne multispectral remote sensing procedure in the estimation of instantaneous and daily evapotranspiration rates.

A procedure was developed to generate raster layers of the footprint weights for weighting/integrating the different components of the energy balance model and obtain meaningful comparisons to similar energy balance terms measured at eddy covariance and/or Bowen ratio stations.

Soil heat flux and surface aerodynamic temperature models were studied in an effort to improve the remote sensing estimation of distributed evapotranspiration rates. Aerial …

Takagi–Sugeno Fuzzy Modeling Of Skin Permeability, Deepak R. Keshwani, David D. Jones, Rhonda M. Brand

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The skin is a major exposure route for many potentially toxic chemicals. It is, therefore, important to be able to predict the permeability of compounds through skin under a variety of conditions. Available skin permeability databases are often limited in scope and not conducive to developing effective models. This sparseness and ambiguity of available data prompted the use of fuzzy set theory to model and predict skin permeability. Using a previously published database containing 140 compounds, a rule-based Takagi–Sugeno fuzzy model is shown to predict skin permeability of compounds using octanol-water partition coefficient, molecular weight, and temperature as inputs. Model …

Evapotranspiration Using A Satellite-Based Surface Energy Balance With Standardized Ground Control, Ricardo Trezza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study evaluated the potential of using the Surface Energy Balance Algorithm for Land (SEBAL) as a means for estimating evapotranspiration (ET) for local and regional scales in Southern Idaho. The original SEBAL model was refined during this study to provide better estimation of ET in agricultural areas and to make more reliable estimates of ET from other surfaces as well, including mountainous terrain. The modified version of SEBAL used in this study, termed as SEBAL_ID (lD stands for Idaho) includes standardization of the two SEBAL "anchor" pixels, the use of a water balance …

The Import Of Importing And Unnatural Acts: The Political Psychology Of Bioengineered Plants, Ibpp Editor

International Bulletin of Political Psychology

This article describes political psychological aspects of opposition to the importing of bioengineered plants.

Development Of A Biologically Based Aerobic Composting Simulation Model, Dennis P. Stombaugh, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

A relatively simple dynamic model based on microbial process kinetics has been developed for aerobic composting. Differential equations describing microbial, substrate, and oxygen concentrations, as well as moisture and temperature profiles have been derived as a function of vessel size and aeration rate. Microbial biomass growth was described using Monod growth kinetics as a function of degradable substrate concentration, oxygen concentration, moisture content, and compost temperature. Facility and fan operating costs have been included to permit economic optimization of the process. Predicted results demonstrated the ability of the model to quantify and describe the influence of multiple interacting factors (temperature, …

Does Junk Dna Regulate Gene Expression In Humans, M. A. Hulten, Michael W. Stacey, S. J. Armstrong

Bioelectrics Publications

No abstract provided.

Termites Or White Ants, Clee Francis Howard Jenkins

Journal of the Department of Agriculture, Western Australia, Series 4

TERMITES are commonly but erroneously called "white ants."

Actually they are more nearly related to cockroaches than to ants, but their general appearance and subterranean habits have given strong support to the popular designation.

They may be divided into two major groups from an economic point of view, viz., wood-dwelling and earth-dwelling termites.