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Full-Text Articles in Life Sciences

Inheritance, Differential Expression, And Candidate Gene Analyses For Avr2 In Phytophthora Sojae, Chelsea S. Ishmael Feb 2016

Inheritance, Differential Expression, And Candidate Gene Analyses For Avr2 In Phytophthora Sojae, Chelsea S. Ishmael

Electronic Thesis and Dissertation Repository

Phytophthora sojae is an oomycete responsible for seed, root and stem rot of soybean plants. Managing this disease relies on growing soybean cultivars with race-specific resistance (Rps) genes that deliver complete host immunity in the presence of corresponding pathogen avirulence (Avr) effector proteins. The aims of this study were to characterize virulence towards Rps2 among different P. sojae strains, track the inheritance of this trait, and attempt to identify an Avr2 gene. Fifteen P. sojae strains were tested for virulence towards Rps2 and crosses were performed between selected virulent and avirulent strains to follow the inheritance of virulence. …


Weather And Photoperiod Indices Of Autumn And Winter Dabbling Duck Abundance In The Mississippi And Atlantic Flyways Of North America, Lena M. Van Den Elsen Jan 2016

Weather And Photoperiod Indices Of Autumn And Winter Dabbling Duck Abundance In The Mississippi And Atlantic Flyways Of North America, Lena M. Van Den Elsen

Electronic Thesis and Dissertation Repository

Climate change may influence autumn and winter distributions of dabbling ducks throughout the Atlantic and Mississippi Flyways of North America. To determine how weather and photoperiod influenced autumn-winter abundances of dabbling ducks at staging areas in eastern North America, I modeled weather and photoperiod variables with rate of change in relative abundance of various dabbling duck species over space and time. Latitude was incorporated into models to determine if changes in duck abundance in relation to weather severity were influenced by locale. Changes in abundance were best described by weather models incorporating temperature and snowfall variables for all species except …


Investigating The Suitability Of The Crayfish Metabolome As A Bioindicator Of Stream Conditions, Natalie M. Izral Jan 2016

Investigating The Suitability Of The Crayfish Metabolome As A Bioindicator Of Stream Conditions, Natalie M. Izral

Electronic Thesis and Dissertation Repository

The suitability of the crayfish metabolome as a bioindicator of stream conditions was investigated because there is a need for fast responding, sensitive, diagnostic, and ecologically relevant bioindicators. A laboratory study assessed Procambarus clarkii metabolome sensitivity to six different treatments of food or DO stress. A field study in subcatchments of the Red River Valley, Manitoba, Canada assessed the effects of land-use type (reference, agriculture, wastewater effluent) on the Orconectes virilis metabolome. Crayfish were sacrificed, and hepatopancreas, gill, and tail tissues were dissected. Analyses found the metabolome was sensitive enough to potentially diagnose food and DO stress in P. clarkii …


Examining The Role Of Atrx In Astrocytes, Haley Mcconkey Jan 2016

Examining The Role Of Atrx In Astrocytes, Haley Mcconkey

Electronic Thesis and Dissertation Repository

Astrocytes perform many homeostatic roles in the brain while supplying metabolites to neurons and mediating synaptic transmission. The current study explored a possible role of the Atrx gene in astrocytes. Hypomorphic mutations in this gene cause the ATR-X intellectual disability syndrome. Deletion of Atrx in the forebrain leads to an apparent increase in reactive astrocytes, potentially caused by the high level of neuroprogenitor cell death. To avoid such non cell-autonomous effects on astrocytes, we generated mice with inducible conditional inactivation of Atrx in astrocytes. Preliminary analysis two weeks following induction of Atrx gene deletion revealed variably lower expression of Connexin …


Structural And Functional Studies Of The Heptose Modifying Enzymes That Play A Role In Campylobacter Jejuni Virulence., Heba Soliman Barnawi Jan 2016

Structural And Functional Studies Of The Heptose Modifying Enzymes That Play A Role In Campylobacter Jejuni Virulence., Heba Soliman Barnawi

Electronic Thesis and Dissertation Repository

Campylobacter jejuni is a major cause of gastroenteritis in humans. The capsule of some species contains unique modified heptoses. Heptose modification was elucidated for C. jejuni NCTC11168 and 18-176, and novel epimerases and reductases essential for the heptose modification were identified. We hypothesized that heptose modifying enzymes in C. jejuni have specific catalytic residues that allow for substrate and product specificity. Substrate synthesis, structural modeling, point mutations, and enzymatic analysis have been applied to map the active sites. Putative catalytic residues showed substrate and/or product specificity. The epimerases structures were solved by crystallography done by our collaborator. We also hypothesized …