Arbuscular mycorrhizal fungi (AMF) may exert profound influences on ecosystem resilience and invasion resistance in western North American sagebrush steppe and other arid rangeland plant communities. Maintenance of plant community structure through ecological feedbacks such as facilitation of nutrient cycling and uptake by host plants, physical and chemical contributions to...
Variations in ocean conditions influenced by climate fluctuations may impact fish populations by changing their spatial distribution, physiology, survival, and other ecological features. Somatic growth is a crucial aspect of the biology of fishes and an important contributor to biomass fluctuations. Climate variability also affects somatic growth rates along the...
The majority of the Earth's shallow crust is composed of basalt that erupted on the seafloor and was subsequently altered by chemical exchange with seawater. One aspect of this alteration is the replacement of glass by secondary minerals, including clays. Petrographic thin sections from ODP Holes 504B and 896A revealed...
Potentially relevant literature for the years 1990-1999 was identified by (a) conducting keyword searches of computerized bibliographic databases, especially CAB Abstracts and Aquatic Sciences and Fisheries Abstracts, (b) reading through the tables of contents of a few especially relevant journals, (c) searching the internet for pertinent bibliographies, and (d) to...
Uncertainty in above ground forest biomass (AGB) estimates at broad-scale depends primarily on three sources of error that interact and propagate: measurement error, model error, and sampling error. Using Monte Carlo simulations, we compare the total propagated error for two sets of regional-level component equations for lodgepole pine AGB, and...
Symbiosis is the close and protracted interaction between organisms. The molecular interactions that occur during symbiosis are complex with multiple barriers that must be overcome. Many Gram-negative, host-associated bacteria use a type III secretion system to mediate associations with their eukaryotic hosts. This secretion system is a specialized apparatus for...
L-pipecolic acid (L-PA) is the higher homolog of proline. It occurs naturally in
many organisms, including primates, as an intermediate in lysine degradation. The
pathway by which lysine is converted into L-pipecolic acid employs the enzyme Lpipecolate
oxidase (L-PO), and appears to be tissue specific to the central nervous system...
Managers of forest and plantation ecosystems are encountering growing problems involving plant pathogens and the expanding geographic ranges of these pathogens. Historically unexposed stands are exceptionally vulnerable when a non-native pathogen is introduced because these pathogens can cause devastating disease in a host population that lacks co-evolved resistance mechanisms. One...
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....