Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Entire DC Network

A Mathematical Model Of Moisture Movement And Bacterial Growth In Two-Dimensional Porous Medium, Rachel Elizabeth Tewinkel May 2014

A Mathematical Model Of Moisture Movement And Bacterial Growth In Two-Dimensional Porous Medium, Rachel Elizabeth Tewinkel

Theses and Dissertations

Bacterial growth in sand is of concern in regard to the health of beaches. A mathematical model is presented that represents the movement of moisture and the growth of bacteria through a beach. Simulations were run by numerically solving Richards Equation using a Finite Volume Method in order to track moisture movement. A model of moisture-dependent bacterial growth was then implemented. These simulations show that elevated bacteria counts following rain events do not necessarily result from bacteria in the body of water, but can also be sourced from the sand. Additionally, four different moisture-dependent bacterial growth models are compared to …


Antimicrobial Resistance Of Channel Catfish Intestinal Microflora In The Arkansas And Ninnescah Rivers In Kansas, Jordan R. Hofmeier May 2014

Antimicrobial Resistance Of Channel Catfish Intestinal Microflora In The Arkansas And Ninnescah Rivers In Kansas, Jordan R. Hofmeier

Master's Theses

Antimicrobial compounds have been used by humans to counteract bacterial infections since 1910. Overuse of these compounds in clinical and agricultural applications has led to rapid evolution and global spread of antimicrobial resistance and rivers are the main receiving body for antimicrobials and resistant bacteria from urban effluents and agricultural runoff. When antimicrobial-resistant bacteria enter the aquatic environment, water acts as a physical pathway for their distribution. Subsequently, resistance genes become established in natural systems and pose threats to human health and ecological processes. Due to these potential threats, antimicrobial resistance in the aquatic environment should be closely monitored. To …


Dispersal Of Antibiotic-Resistant Bacteria Near Central Great Plains Feedlots, Jennifer R. Pfannenstiel-Klaus May 2014

Dispersal Of Antibiotic-Resistant Bacteria Near Central Great Plains Feedlots, Jennifer R. Pfannenstiel-Klaus

Master's Theses

Antibiotic resistance is a growing concern in medical and veterinary settings. Resistance can be worsened by misuse and overuse of antibiotics. Such situations can give rise to highly resistant organisms. Ciprofloxacin, a synthetic, broad-spectrum antibiotic used to treat gram-positive and gram-negative infections in humans, has similar chemical structure to enrofloxacin, which is used to treat animals. Cross-resistance might arise because of that similarity. This research describes the dispersal and prevalence of bacteria that exhibit ciprofloxacin resistance in relation to feedlots in the central Great Plains region. Six times in 2013, six feedlots were sampled for airborne bacterial communities at, upwind …


Remediation Of Tetracycline From Water Sources Using Vetiver Grass (Chrysopogon Zizanioides L. Nash) And Tetracycline-Tolerant Root-Associated Bacteria, Aparupa Sengupta Jan 2014

Remediation Of Tetracycline From Water Sources Using Vetiver Grass (Chrysopogon Zizanioides L. Nash) And Tetracycline-Tolerant Root-Associated Bacteria, Aparupa Sengupta

Dissertations, Master's Theses and Master's Reports - Open

Antibiotics are emerging contaminants worldwide. Due to insufficient policy regulations, public awareness, and the constant exposure of the environment to antibiotic sources has created a major environmental concern. Wastewater treatment plants (WWTP) are not equipped to filter-out these compounds before the discharge of the disinfected effluent into water sources (e.g., lakes and streams) and current available technologies are not equipped to remediate these compounds from environmental sources. Hence, the challenge remains to establish a biological system to remove these antibiotics from wastewater. An invitro hydroponic remediation system was developed using vetiver grass (Chrysopogon zizanioides L. Nash) to remediate tetracycline …


Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski Jan 2014

Structure-Function Analysis Of Zapc, An Ftsz-Ring Stabilizer, In Escherichia Coli Cytokinesis, Lukasz Tchorzewski

Dissertations and Theses

In Escherichia coli, cell division is defined by the polymerization and constriction of a cytokinetic ring (Z ring) formed by FtsZ, a tubulin-like GTPase, at midcell. Division also involves the formation of a multi-protein complex at midcell known as the divisome. Several divisome proteins promote the assembly/disassembly processes of FtsZ, thereby exercising spatiotemporal control over division. Among FtsZ regulatory proteins are the FtsZ ringassociated proteins (Zap), which either directly or indirectly stabilize the Z-ring by increasing lateral interactions amongst FtsZ protofilaments in the Z-ring. ZapA-D are recruited during early cytokinesis and have overlapping functions in stabilizing FtsZ at midcell, but …


Microbial Communities Colonizing Leaves During Early Decomposition Stages, Stephanie Harper Jan 2014

Microbial Communities Colonizing Leaves During Early Decomposition Stages, Stephanie Harper

Electronic Theses and Dissertations

Microbial communities associated with decaying leaves play an important role in the cycling of nutrients in stream ecosystems. In headwater streams that are deemed as heterotrophic, bacteria and fungi are main drivers of organic matter decomposition and thus partly responsible for facilitating the cycling of nutrients from leaves that fall into the stream. The main objective of this study was to compare microbial community composition between different leaf types during breakdown in stream ecosystems. To achieve this objective, I used a combination of field and laboratory trials. Field experiments were performed at the Luquillo Experimental Forest using Dacryodes excelsa and …