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Full-Text Articles in Life Sciences

Functional Morphology, Biomechanics, And Evolution Of Ruminant Mammals, Abby Vander Linden Oct 2021

Functional Morphology, Biomechanics, And Evolution Of Ruminant Mammals, Abby Vander Linden

Doctoral Dissertations

Ruminant mammals, including the families Bovidae, Cervidae, Tragulidae, Moschidae, Antilocapridae, and Giraffidae, display incredible past and present diversity in morphology, ecology, and behavior. They inhabit an impressive range of environments across North and South America, Europe, Asia, and Africa, and compel the fascination of naturalists and researchers alike with their charismatic social behavior and conspicuous cranial appendages. I explore the drivers and consequences of this spectacular diversity through a comparative morphological framework, biomechanical modeling approaches, and semi-parametric and likelihood-based methods for estimating state-dependent diversification rates across the ruminant phylogeny. Together, these investigations provide evidence for adaptation via correlated evolution of …


Monitoring Mammals At Multiple Scales: Case Studies From Carnivore Communities, Kadambari Devarajan Oct 2021

Monitoring Mammals At Multiple Scales: Case Studies From Carnivore Communities, Kadambari Devarajan

Doctoral Dissertations

Carnivores are distributed widely and threatened by habitat loss, poaching, climate change, and disease. They are considered integral to ecosystem function through their direct and indirect interactions with species at different trophic levels. Given the importance of carnivores, it is of high conservation priority to understand the processes driving carnivore assemblages in different systems. It is thus essential to determine the abiotic and biotic drivers of carnivore community composition at different spatial scales and address the following questions: (i) What factors influence carnivore community composition and diversity? (ii) How do the factors influencing carnivore communities vary across spatial and temporal …


Diversity And Evolution Of Human Eccrine Sweat Gland Density, Andrew W. Best Oct 2021

Diversity And Evolution Of Human Eccrine Sweat Gland Density, Andrew W. Best

Doctoral Dissertations

Human eccrine density is highly derived. However, little is known about contemporary variation in this trait, what shapes it, and how it influences heat dissipation. This project explores 3 questions: 1) Is variation in functional eccrine density (FED) explained by childhood climate? 2) Is this variation patterned by geographic ancestry? 3) Is variation in FED associated with differences in heat dissipation capacity? We measured FED and sweat production in 6 body areas via pharmacological stimulation and impressions of sweating skin in 72 participants. Childhood climate variables were taken from the WorldClim database and geographic ancestry was estimated with 23andMe tests. …


Mechanisms Of Mitotic Checkpoint Silencing By The Disordered Kinetochore Protein Spc105, Margaux Audett Oct 2021

Mechanisms Of Mitotic Checkpoint Silencing By The Disordered Kinetochore Protein Spc105, Margaux Audett

Doctoral Dissertations

The kinetochore protein Spc105R (DmSpc105R) is a large intrinsically disordered protein (IDP) that recruits spindle assembly checkpoint (SAC) proteins and is required for SAC signaling in a conserved manner. Chromosome biorientation satisfies the SAC and while it has been proposed that SAC satisfaction may require the establishment of stable kinetochore-MT (KT-MT) attachments and tension generation, the question of whether tension directly regulates SAC signaling is unresolved and controversial. Here we present data in support of Spc105R as a tension-sensing IDP that directly regulates checkpoint protein localization and signaling independent of the establishment of stable KT-MT attachments. The N-terminus of DmSpc105R …


The Role Of Med31 And Med12 In Directing Adipogenesis Of Human Adult-Derived Mesenchymal Stem Cells, Joseph Straub May 2021

The Role Of Med31 And Med12 In Directing Adipogenesis Of Human Adult-Derived Mesenchymal Stem Cells, Joseph Straub

Doctoral Dissertations

Selective gene expression is crucial in maintaining the self-renewing and multipotent properties of stem cells. Mediator is a large, evolutionarily conserved, multisubunit protein complex that modulates gene expression by relaying signals from cell type-specific transcription factors to RNA polymerase II. In humans, this complex consists of 30 subunits arranged in four modules: head, middle, tail, and kinase. In our introduction, we show the state of the field of Mediator study with a focus on the critical kinase module. In the following chapters, we used siRNA knockdowns to investigate the roles of the highly-conserved core subunit MED31 and the kinase module …


Dynamic Evolution In The Leucine-Rich Repeat Receptor-Like Kinase (Lrr-Rlk) Family Of Receptors, Jarrett Man Apr 2021

Dynamic Evolution In The Leucine-Rich Repeat Receptor-Like Kinase (Lrr-Rlk) Family Of Receptors, Jarrett Man

Doctoral Dissertations

Cells in multicellular organisms must gauge their environmental conditions, including neighboring cells, during development. In plants, the Leucine-Rich Repeat Receptor-like Kinases (LRR-RLKs) encode a family of membrane-bound receptors that transduce such cell-to-cell signals and are required for many aspects of plant development. Very little is known about the function of most of these genes, and the evolutionary history of the family is difficult to infer because of its size and complexity. Several factors contribute to this difficulty, including genetic redundancy, challenging bioinformatic detection, exceptionally large family size, and high copy number variation among species. In this dissertation, I characterize some …