Wheat endosperm morphogenesis was studied by light microscopy
during the entire growth period of anthesis to maturity. Four
developmental stages have been described in this thesis: (1) double
fertilization, (2) formation of the lower endosperm cells, (3)
termination of nuclear divisions, and (4) initiation of protein
bodies.
The first manuscript...
Marine bacterioplankton play an important role in global elemental cycles because they return carbon dioxide and nutrients to the biosphere as they reduce organic matter. Furthermore, marine bacterioplankton are not uniformly active, and subpopulations of the in situ community may be more or less active at any given time. Defining...
This research examines the downstream fining phenomenon as it operates in coastal gravel-bed rivers of Oregon. Downstream fining is a change in bed composition toward smaller sediment sizes in the downstream direction. Changes in stream flow discharge and channel slope affect the rate of bed-load transport, thereby altering the downstream...
This thesis includes three studies involving different aspects of modeling protein structure. The first study illustrates the levels of insight available from atomic-resolution protein structures. The second study derives general trends of protein geometry from atomic-resolution structures and shows their implications for modeling. The third study creates a model of...
Swiss needle cast (SNC) is a foliage disease of Douglas-fir caused by Nothophaeocryptopus gaeumannii, an Ascomycete fungus (Mycosphaerellaceae) that causes growth reductions in Douglas-fir plantations across the Pacific Northwest. Epidemiology of the fungus is generally well known in plantation trees, but the relationship between disease expression and foliage nutrition and...
The first goal of this study was to understand the role of u-calpain in skeletal muscle protein degradation in cultured muscle cells. Several strategies were developed to down-regulate endogenous u-calpain activity and m-calpain activity in rat myotubes. These included over-expression of antisense u-calpain (AnsL), dominant negative u-calpain (DN-u-CL), antisense 30K...
Skeletal muscle is the largest organ in the body by mass, comprising roughly 40% of total bodyweight in adults. It plays diverse and unique roles that include movement, locomotion, and support for posture and internal organs, among others. The structural foundation for all skeletal muscle in adults is formed early...
Despite the advances in surgery, physical therapy, and pharmaceutical agents, muscle
dysfunction (i.e., atrophy and weakness) continues to impair recovery from an anterior
cruciate ligament (ACL) injury and surgery. Ischemia-reperfusion injury during surgery
and the subsequent limb disuse are two events experienced by patients having ACL
surgery. Oxidative stress and...
Inflorescence necrosis (IN) is a recently described disorder in grapes
characterized by partial or complete deterioration of the pedicel and rachis near
bloom. Elevated levels of ammonium in the rachis are associated with the
incidence of IN and hypothesized as the cause of the disorder. An incubation
system with single-node...
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...