Photobiological hydrogen production from live cells of the cyanobacterium Synechocystis sp. PCC 6803 encapsulated in silica gel was investigated. Hydrogen is a dense energy carrier with potential to reduce dependence on fossil fuels, provided a renewable and sustainable means of production can be achieved. Under certain conditions, Synechocystis sp. PCC...
Photobiological hydrogen production -- the use of photosynthesis to split water into hydrogen and oxygen -- presents an opportunity for efficient and large-scale solar biofuel development. One of the major challenges in this area is competition for reductant between the hydrogen-evolving hydrogenase enzyme and other metabolic pathways. In this work...
Cell-to-cell communication by chemical signals, termed quorum sensing (QS), is a common regulatory scheme in the microbial world. Pseudomonas aeruginosa¸ an opportunistic pathogen of burn wounds and cystic fibrosis lungs, uses QS to control the expression of hundreds of genes, particularly those necessary for population level benefits such as biofilm...
In this dissertation, we consider two problems in number theory, both relating to modular forms. First we consider when a given modular form can be expressed as a quotient in Dedekind's $\eta$ function. Rouse and Webb \cite{RW} have determined the integers $N \leq 500$ such that the graded ring of...
Cyanobacteria inhabit nearly every ecosystem on earth, play a vital role in nutrient cycling, and are
useful as model organisms for fundamental research in photosynthesis and carbon and nitrogen fixation.
In addition, they are important for several established biotechnologies for producing food additives,
nutritional and pharmaceutical compounds, and pigments, as...
Feminist compositionists have long argued for addressing the feminization of composition, or its association with low value “women’s work,” by revaluing caring labor (Enos; Heinert and Phillips; Tuell). However, this argument assumes that writing teachers’ care work is beneficial for all students and teachers. Focusing on responding to student writing...
The diffusion of divalent nickel (Ni²⁺) from wet silica gels was investigated.
Silica gel is gaining interest as an encapsulation matrix for biological components.
The transport of biologically relevant species within the gel is determined by the
structural characteristics of the gel, which are in turn governed by synthesis
parameters....
Corals have multiple roles in maintaining ocean health and are some of the world’s most diverse ecosystems. The coral animal is host to a multitude of taxa, including symbiotic dinoflagellate algae, fungi, bacteria, protists, and viruses. Environmental stressors and disease agents can perturb the delicate balance of the coral host...
In real networks, identifying dense regions is of great importance. For example, in a network that represents academic collaboration, authors within the densest component of the graph tend to be the most prolific. Dense subgraphs often identify communities in social networks. And dense subgraphs can be used to discover regulatory...
The purpose of this study is to investigate the role of the
source of the external trade statistics in measuring the price
responsiveness of foreign demands and relative price competitiveness
of the major exporting countries in trade of agricultural commodities
in international markets. In particular, the papers included in this...
Lichens are an important part of the biota in western Oregon forests, where
they perform valuable ecological roles and contribute significantly to biodiversity.
Lichens in western Oregon are threatened by a number of factors including air
pollution and land use practices. If we wish to maintain the persistence of lichens...
Freshwater cyanobacterial blooms are a nuisance and health threat in the Pacific Northwest. The accepted methods of characterizing these blooms by microscopic cell counts cannot differentiate between toxic and non-toxic strains of the cyanobacterium Microcystis. Also, there is limited understanding of freshwater cyanophage that may control bloom dynamics. In order...
Microbial electrochemical systems (MESs) have attracted much research attention in recent years due to their promising applications in renewable energy generation, bioremediation, and wastewater treatment. In a MES, microorganisms interact with electrodes via electrons, catalyzing oxidation and reduction reactions at the anode and the cathode.
The bacterial community of a...
The objective of this study was to compare light wood framing and traditional timber
framing quantitatively through environmental impact assessment and load path analysis. This
research was inspired by a traditional timber frame structure constructed in Vermont in 2011, and
the design of structures considered within reflect the general characteristics...
The objectives of the experiment were to: 1) determine the relationship
between overstory canopy cover and ungulate herbivory on understory production
composition and diversity and 2) determine the effects of timber harvest, ungulate
herbivory and season of use on botanical composition and nutritional quality of
beef cattle diets. Three randomly...
The main objective of this study was to offer an alternative methodology for
forest sector modeling in developing economies. To this effect, a policy preference
function was developed and estimated using data from the forest sector of the Cote
d'Ivoire.
The justification for this alternative framework for forest sector analysis...