Digital Commons Network^™

Quantification Of Hydrologic Response To Forest Disturbance In Western U.S. Watersheds, Sara A. Goeking '92

Doctoral Dissertations

Forested watersheds produce more than half of the water supply in the United States. Forests affect how precipitation is partitioned into available water versus evapotranspiration. This dissertation investigated how water yield and snowpack responded to forest disturbance following recent disturbances in western U.S. forests during the period 2000-2019.

Chapter 2 systematically reviewed 78 recent studies that examined how water yield or snowpack changed after forest disturbances. Water yield and snowpack often increased after disturbance, but decreased in some circumstances. Decreased water yield was most likely to occur following disturbances that did not remove the entire forest canopy. It was also …

The Statistical Dynamics Of Nonequilibrium Control, Grant Murray Rotskoff '09

Doctoral Dissertations

Living systems, even at the scale of single molecules, are constantly adapting to changing environmental conditions. The physical response of a nanoscale system to external gradients or changing thermodynamic conditions can be chaotic, nonlinear, and hence difficult to control or predict. Nevertheless, biology has evolved systems that reliably carry out the cell’s vital functions efficiently enough to ensure survival. Moreover, the development of new experimental techniques to monitor and manipulate single biological molecules has provided a natural testbed for theoretical investigations of nonequilibrium dynamics. This work focuses on developing paradigms for both understanding the principles of nonequilibrium dynamics and also …

Stem Cell Biology And Strategies For Therapeutic Development In Degenerative Diseases And Cancer, Angel A. Alvarez '98

Doctoral Dissertations

Stem cell biology is an exciting field that will lead to significant advancements in science and medicine. We hypothesize that inducing the expression of stem cell genes, using the embryonic stem cell gene nanog, will reprogram cells and dedifferentiate human mesenchymal stem cells into pluripotent stem cells capable of neural differentiation. The aims of initial studies are as follows:

Aim 1: Demonstrate that forced expression of the embryonic stem cell gene nanog induces changes in human mesenchymal stem cells to an embryonic stem cell-like phenotype.

Aim 2: Demonstrate that induced expression of nanog up-regulates the expression of multiple embryonic stem …

Environmental Implications Of Francisella Tularensis Biofilms, Jeffrey J. Margolis '00

Doctoral Dissertations

Francisella tularensis survives in one of the widest environmental ranges of any pathogen. Numerous mammals and arthropod vectors are infected by this highly virulent organism. How this zoonotic pathogen persists outside of its many hosts remains unexplored. We aimed to examine how F. tularensis interacts with environmental surfaces, and hypothesized that biofilm formation may enable survival of this organism in nature. By understanding the role these surface-attached bacterial communities play in F. tularensis ecology, we hope to gain insight into the mechanisms of environmental persistence and transmission of this pathogen.

We identify chitin as a potential non-host niche for F. …