Circadian clocks coordinate molecular, cellular, physiological, and behavioral processes with the 24-hour solar day. While clock functions are well understood in young animals, it is not clear how aging or neurodegenerative disease affects the various levels of the circadian system. A common symptom of many neurodegenerative diseases including Alzheimer’s disease...
Auditory defects and disorders are prevalent at all ages and affect 8% of the population in developed nations including newborns and children. Congenital hearing loss is the most common birth defect and it is estimated that 1 in 1000 children are affected by deafness at birth or before the onset...
The human cathelicidin antimicrobial peptide (CAMP) is a broad spectrum microbicidal agent and modulator of both the innate and adaptive immune system. It is induced by 1,25-dihydroxyvitamin D (1,25(OH)₂D₃) through activation of the vitamin D receptor (VDR) and primary bile salts through activation of the xenobiotic nuclear receptor farnesoid X...
Circadian clocks are endogenous molecular mechanisms that coordinate daily rhythms in gene expression, cellular activities, and physiological functions with external day/night cycles. Breakdown of circadian rhythms such as sleep/wake cycles is associated with the onset of several neurological diseases; however, it is not clear whether disruption of rhythms is a...
Coibamide A is a methyl-stabilized cyclic depsipeptide with a lariat side chain that was isolated from a marine cyanobacterium as part of an International Cooperative Biodiversity Groups program based in Panama. Previous testing of this potent and selective growth-inhibitory agent in the National Cancer Institute (NCI) in vitro 60 human...
Sexual selection can influence the mating system of an organism through multiple mechanisms. These mechanisms result in variation in reproductive success among individuals, and include scramble competition, endurance rivalries, contests, mate choice and cryptic choice, and sperm competition. Understanding the mating system of a species requires the identification of which...
Darwin devised the evolutionary theory of sexual selection to account for the manifold extravagances of courtship behaviors and displays. Mating interactions represent a major evolutionary process driving the elaboration, vibrancy, and peculiarity of these courtship traits. For my dissertation research, I strived to elucidate the dynamics that constitute the complex...
In this dissertation I study evolutionary patterns at genes encoding antimicrobial peptides (AMPs) in frogs. AMPs are short, amphipathic, cationic, secreted proteins that kill bacteria and other pathogens through a non-catalytic mechanism that involves
binding to and disrupting the microbial cell membrane. In many animal taxa, positive selection is much...