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Biological Motion Processing In Typical Development And In The Autism Spectrum, Aaron Krakowski

Dissertations, Theses, and Capstone Projects

Biological motion (BM) analysis and interpretation is a fundamental process of human neurocognition that has been only minimally explored neurophysiologically. In addition to its importance in understanding the underlying roots and development of social cognition, BM processing is a prime candidate domain for exploring the underlying etiology of social cognitive disorders such as the autism spectrum.

In an initial experiment, typical adults observed BM point-light displays of a human actor (UM) as well as their spatially scrambled counterparts (SM), in both an unattended distractor task as well as an explicit attention task. Results showed a neurophysiological response manifested as three …

Age-Related Aspects Of Mirror-Use By Bottlenose Dolphins (Tursiops Truncatus), Rachel A. Morrison

Dissertations, Theses, and Capstone Projects

Bottlenose dolphins are neuroanatomically different and evolutionarily divergent from primates yet they exhibit mirror self-recognition (MSR), a rare cognitive ability in non-human animals. This research investigated the developmental and age-related aspects of MSR in this species. During a longitudinal study, a social group of bottlenose dolphins at the National Aquarium, Baltimore, MD were exposed to a mirror and their behavioral responses were recorded to: 1) further confirm the presence of MSR in this species, 2) determine the age of emergence of MSR and 3) draw comparisons with data documenting the emergence of this ability in humans and great ape species. …

Attention Shapes Our Expectations And Perceptions: The Neural Mechanisms Of Top-Down Attention During Adulthood And Development, Snigdha Banerjee

Dissertations, Theses, and Capstone Projects

Top-down attention is the focusing of attention at one's will through knowledge regarding a current task. There is evidence that top-down attention involves the modulation of sensory cortices by higher order regions. However, the mechanisms of top-down attention across sensory modalities, its influence on early sensory inputs, as well as interactions with motivational systems remain unclear. We performed the following set of electrophysiological experiments in typically developed adults and adolescents to examine these areas. 1) The supramodal attentional theory holds that parietally-based attentional mechanisms are shared across sensory modalities. We tested the supramodal theory by examining if lateralized parieto-occipital alpha-band …

Developmental Cis-Regulatory Analysis Of The Cyclin D Gene In The Sea Urchin Strongylocentrotus Purpuratus, Christopher Michael Mccarty

Electronic Theses and Dissertations

Proper execution of animal development requires that it be integrated with cell division. In part, this is made possible due to cell cycle regulatory genes becoming dependent upon developmental signaling pathways that regulate their transcription. Cyclin D genes are important bridges linking the regulation of the cell cycle to development because these genes regulate the cell cycle, growth and differentiation in response to intercellular signaling. In this dissertation, a cis-regulatory analysis of a cyclin D gene, Sp-CycD, in the sea urchin, Strongylocentrotus purpuratus, is presented. While the promoters of vertebrate cyclin D genes have been analyzed, the cis-regulatory sequences across …

The Ontogeny Of Whistle Production In Infant Atlantic Bottlenose Dolphins (Tursiops Truncatus) During The First Thirty Days Of Life, Brittany Leigh Jones

Master's Theses

The manner in which dolphin calves acquire their whistle repertoire is largely unknown. This paper focuses on whistle development in four bottlenose dolphin calves during the first thirty days of life in order to increase our understanding of the early emergence of whistles and whistle-like vocalizations. The acoustic parameters of whistle-type vocalizations (i.e., whistles and whistlesquawks) that coincided with a bubblestream emission from the focal calf and/or its mother were analyzed, as were the behavioral states of the mother-calf pair during the emission of such vocals. Mother and calf whistle rates are inversely related, with the mother whistling more often …

Phylogeny And Population Genetics Of The Endangered Dwarf Bear-Poppy, Arctomecon Humilis Coville (Papaveraceae) Using Microsatellite Markers, Joshua Simpson

Dissertations, Theses, and Capstone Projects

The genus Arctomecon (Papaveraceae) is comprised of three narrowly endemic rare species that are largely restricted to gypsum soils of the eastern Mojave Desert. The small, remaining populations of these species have become increasingly isolated by urban development and habitat fragmentation. Arctomecon humilis is federally listed as endangered due to its limited distribution within a ~15 km radius of an actively expanding city. Organizations involved with land management and conservation have called for greater insight into the genetic variation and population structure of the remaining subpopulations as they make important decisions regarding where to focus their efforts and resources.

The …

Role Of Cardiac Catecholamines In Embryos And Adults Under Stress, Candice Baker

Electronic Theses and Dissertations

Cardiovascular disease is responsible for the loss of one life every 38 seconds and accounts for 26.6 percent of all infants that die of congenital birth defects. Adrenergic hormones are critically important regulators of cardiovascular physiology in embryos and adults. They are key mediators of stress responses and have profound stimulatory effects on cardiovascular function, and dysregulation of adrenergic function has been associated with many adverse cardiac conditions, including congenital malformations, arrhythmias, ischemic heart disease, heart failure, and sudden cardiac death. Despite intensive study, the specific roles these hormones play in the developing heart is not well-understood. Further, there is …

Cochlear Development And Auditory Function In The Absence Of Thyroid Hormone Transporters Mct8 And Oatp1c1, Richard Sinn

All Graduate Theses, Dissertations, and Other Capstone Projects

Thyroid hormone (TH) is essential for the development and maturation of the nervous system. The thyroid gland secretes an active form of TH, triiodothyronine, and a prohormone, thyroxine, into the blood. TH is charged, which prevents it from passively diffusing across cell membranes and thus requires cell membrane transporters to facilitate its movement into and out of cells. However, whether TH transporters are required for TH-mediated developmental events, including the auditory system, is largely unknown.

The purpose of the present study was to investigate two specific TH transporters, monocarboxylate transporter 8 (Mct8) and organic anion transporting polypeptide 1c1 (Oatp1c1), and …