A phytoplankton bloom dominated by the pennate diatom Nitzschia
curta (Van Heurck) Hasle was observed during January-February 1983 at
a receding ice-edge in the Western Ross Sea, Antarctica. The core of
the bloom was found between 100-150 Km from the ice-edge. Nitzschia
curta cell densities up to 22 x 10⁶...
Dissolved silicic acid (Si(OH)4) and biogenic silica (BSiO2) concentrations were measured on four different cruises in the Southern Ocean along 1700 W from late October 1997 to mid-March 1998. These data were used to construct a vertically integrated Si budget in the surface layer from 58° to 68° S. Throughout...
Diatoms are a ubiquitous group of plankton responsible for 20-40% of oceanic
primary production, and a higher fraction of organic matter export to the ocean
interior. Diatoms actively transport dissolved inorganic silicon into their cells, and
through the process of silicification (i.e. biogenic silica production) they build tough
and intricate...
As the frequency and intensity of wildfires continue to occur in the West, so does the need for measures intended to improve firefighter safety; public safety; and the protection of property, resources, and wildlife. Furthermore, as human activity in the expanding Wildland Urban Interface increases, so does the need for...
The focus of this thesis is to design, characterize, and apply novel computational methods and molecular systems to interrogate heterogeneous human gut microbiome-related phenomena. In Chapter 2, I design, implement, and characterize a method for embedding co-occurrence patterns derived from massive 16s amplicon datasets. I use this method to 1....
Boreal and temperate biomes host nearly half of the earth’s forested ecosystems. The temperate rainforests of the Pacific coast of North America constitute nearly half of all temperate rainforests on earth. Along the northern extent of this region, the perhumid and sub-polar rainforests of southeast and southcentral Alaska are among...
There is a growing body of research that describes the benefits of place-based environmental education (EE) within the schools, including improved competencies, better interpersonal skills, decreased gaps in social divides, increased pupil engagement in learning, increased community awareness, and increased environmental stewardship. Though the benefits are many, few schools utilize...
Gut-brain communication consists of bidirectional routes between cognitive centers of the brain and peripheral intestines. This bidirectional communication is the result of the interplay between enteroendocrine cells (EECs), enteric nervous system, central nervous system, the vagus nerve, and our microbiota. Multiple studies have associated gut microbial dysbiosis with neurological disorders...
New delivery methods for radiotracers are constantly being proposed. Two key properties of the delivery method must be analyzed: dose to patient and effectiveness of delivery. In this work, the localized skin dose for intranasal administration of 18F was determined utilizing MCNP code. An anatomically accurate nasal cavity was constructed...
Natural landscapes around the world have experienced serious loss and degradation, which negatively impacts ecosystem service provision by these landscapes. As a result, there have been serious investments to restore natural capital. However, restoration faces complex trade-offs, such as that between restoration quality, or how closely the restored landscapes resembles...
Current neutron dosimetry methods rely on the assumption that charged particle equilibrium (CPE) is established within the tissue medium. This maintains that the kinetic energy transferred to the medium (KERMA) is equivalent to absorbed dose. However, this assumption is only valid for large volumes such as the whole body. For...
Over the last ten years, clinical, pre-clinical and animal studies have shown associations between the microbiota and neurological functions. Recent work by the scientific community on the gut-microbiome-brain axis have revealed that gut dysbiosis and specific microbial taxa are associated with a myriad of neurological conditions, such as autism spectrum...
The lens dose equivalent (LDE) is a regulatory limit set to protect radiation workers. Current methods for estimating the LDE are specific to beam sources in a vacuum and require interpolating data from tables. A new set of deterministic equations for photon and electron point sources has been developed. These...
A long running problem in mathematical biology is the prediction of extinction events, a specialized case of the larger global stability problem found in differential equations and dynamical systems theory. A central technical question is how to introduce the randomness observed in real ecological systems not accounted for in deterministic...