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Full-Text Articles in Life Sciences

The Role Of Gap-43 Phosphorylation In Axon Behavior In The Developing Zebrafish Visual System, Jennifer Forecki Dec 2013

The Role Of Gap-43 Phosphorylation In Axon Behavior In The Developing Zebrafish Visual System, Jennifer Forecki

Theses and Dissertations

Developing neurons extend processes to specific targets and establish connections that are essential for future function of the nervous system. One of these processes, the axon, has a motile tip called a growth cone that rearranges its membrane-associated actin cytoskeleton to turn toward or away from environmental guidance cues. Growth associated protein 43 (GAP-43) is one of the most abundant proteins associated with axonal growth cone membranes and is known to modulate the formation and stability of the actin cytoskeleton during axon guidance. Protein kinase C (PKC)-mediated phosphorylation of GAP-43 on serine 42 regulates its interactions with actin. Phosphorylated ...


The Roles Of N-Myc And L-Myc During Inner Ear Neurosensory Development, Benjamin Joseph Kopecky Dec 2013

The Roles Of N-Myc And L-Myc During Inner Ear Neurosensory Development, Benjamin Joseph Kopecky

Theses and Dissertations

Introduction: Hearing loss affects over 500 million people worldwide and results from irreversible damage to inner ear hair cells. The only available treatment is cochlear implants, which may be unable to provide sensory input if neuronal connections are lost, as they are in mouse models. Thus, regeneration of hair cells offers the only permanent cure; however, such therapeutic intervention requires a detailed molecular understanding inner ear development and hair cell maintenance. During mouse development, there is a balance between proliferation and differentiation that not only determines the size of the ear, but also is needed to form a functional sensory ...


Dystroglycan In Cerebellar Development And Disease, Huy Tuan Nguyen Dec 2013

Dystroglycan In Cerebellar Development And Disease, Huy Tuan Nguyen

Theses and Dissertations

Dystroglycanopathies are muscular dystrophies caused by mutations in genes involved the in O-linked glycosylation of alpha-dystroglycan. Severe forms exhibit brain and ocular developmental abnormalities in addition to muscular dystrophy. While cerebellar dysplasia is a common feature of dystroglycanopathy, its pathogenesis has not been thoroughly investigated. Here we evaluate the role of dystroglycan during cerebellar development. Brain-selective deletion of dystroglycan does not affect overall cerebellar growth, but causes malformations associated with glia limitans disruptions and granule cell heterotopia that recapitulate phenotypes found in dystroglycanopathy patients. Cerebellar pathology in these mice is not evident until birth even though dystroglycan is lost during ...


Taking Tone Into Account: Cognitive Neuroscientific Investigations Of Mandarin Chinese Spoken Word Processing, Jeffrey G. Malins Oct 2013

Taking Tone Into Account: Cognitive Neuroscientific Investigations Of Mandarin Chinese Spoken Word Processing, Jeffrey G. Malins

Electronic Thesis and Dissertation Repository

To date, theories of how humans recognize spoken words have yet to account for tonal languages such as Mandarin Chinese. One reason for this is that we know relatively little about how native speakers of tonal languages process spoken words in the brain. This dissertation addresses this problem by examining Mandarin spoken word processing in both adult native speakers and typically developing children. In adults, functional magnetic resonance imaging (fMRI) was used to assess the extent to which the brain regions involved in processing tonal information are distinct from those involved in vowel processing (Chapter 2), while event related potentials ...


Developmental Characterization Of Tissue Inhibitor Of Metalloproteinase Domain Functions In Xenopus Laevis, Michelle A. Nieuwesteeg Sep 2013

Developmental Characterization Of Tissue Inhibitor Of Metalloproteinase Domain Functions In Xenopus Laevis, Michelle A. Nieuwesteeg

Electronic Thesis and Dissertation Repository

During development the extracellular matrix is cleaved and remodeled to facilitate the large-scale cell rearrangements that are necessary for processes like gastrulation, neurulation, angiogenesis and organogenesis. ECM remodeling occurs primarily through secreted enzymes called matrix metalloproteinases (MMPs). Regulation of MMP activity is achieved through the tissue inhibitor of metalloproteinases (TIMPs), a small family of secreted proteins that bind MMPs in a 1:1 manner to inhibit their activity. Although TIMPs were originally characterized based on their MMP-inhibitory activities, in vitro studies have revealed that TIMPs are multifunctional proteins, with structurally and functionally distinct N- and C-terminal domains. TIMP N-terminal domains ...


Confocal Microscopy Study Of The Embryonic Development Of The Viviparous Nemertean Prosorhochmus Americanus Reveals Larval Features Supporting Indirect Development In Hoplonemerteans, S Tyler Spindle Aug 2013

Confocal Microscopy Study Of The Embryonic Development Of The Viviparous Nemertean Prosorhochmus Americanus Reveals Larval Features Supporting Indirect Development In Hoplonemerteans, S Tyler Spindle

Theses and Dissertations

Recent studies of hoplonenemertean planuliform larvae have clarified their development and provided insight into larval evolution within the phylum. However, an assessment of viviparous development using modern techniques is lacking. To help facilitate a comprehensive comparative evaluation of developmental diversity within hoplonemerteans, we have conducted a confocal laser scanning microscopy investigation of the development in Prosorhochmus americanus, one of the few viviparous hoplonemertean species. Phalloidin staining provides evidence of a modified transitory larval epidermis, and reveals that the foregut, midgut, proboscis, central nervous system, and body wall musculature form early in development, consistent with observations for planktonic and encapsulated hoplonemertean ...


Alternations Of Nmda And Gabab Receptor Function In Development: A Potential Animal Model Of Schizophrenia, Monica Bolton Aug 2013

Alternations Of Nmda And Gabab Receptor Function In Development: A Potential Animal Model Of Schizophrenia, Monica Bolton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Schizophrenia is a debilitating mental disorder that affects up to 3% of the world population. The behavioral symptoms are categorized into positive and negative symptoms, which appear during late adolescence/early adulthood. Unfortunately, the underlying cellular and molecular mechanisms of the disease are poorly understood. Several hypotheses exist to explain mechanisms contributing to these behavioral alterations. One model proposes that a reduced function of the NMDA glutamate receptor on specific GABAergic interneurons may be responsible for deficits in schizophrenia. Post-mortem investigations provide evidence of reductions in both glutamate and GABA-related proteins in patients with schizophrenia. Further, GABAergic interneurons that are ...


The Effects Of Soil Ph And Composition On Blacklegged Tick Molting Success Avian Window Strike Mortality On Union College Campus, Kaleigh Ahern Jun 2013

The Effects Of Soil Ph And Composition On Blacklegged Tick Molting Success Avian Window Strike Mortality On Union College Campus, Kaleigh Ahern

Honors Theses

The blacklegged tick (Ixodes scapularis) is the one of the most significant vectors of infectious disease in the world and most notorious for its ability to transmit Borrelia burgdorferi, the bacteria that causes Lyme disease. Because both the range of the blacklegged tick and the annual incidence of Lyme disease have been increasing in North America over the past several decades, it is becoming increasingly important to better understand how environmental factors contribute to blacklegged tick survival. Past studies have shown that these factors include precipitation levels, extent of groundcover, plant and animal community composition, temperature, and soil type. Because ...


Evaluation Of Survey Methods And Development Of Species Distribution Models For Kit Foxes In The Great Basin Desert, Stephen J. Dempsey May 2013

Evaluation Of Survey Methods And Development Of Species Distribution Models For Kit Foxes In The Great Basin Desert, Stephen J. Dempsey

All Graduate Theses and Dissertations

Historically, kit foxes (Vulpes macrotis) once occupied the desert and semi-arid regions of southwestern North America, ranging from Idaho to central Mexico. Their range-wide decline has warranted the kit fox to be listed as endangered in Colorado, threatened in California and Oregon, and designated as a state sensitive species in Idaho and Utah. Once considered the most abundant carnivore in western Utah, the kit fox has been in steep decline over the past decade, creating a demand to determine kit fox presence. Currently there is little consensus on which survey methodology is best to detect kit fox presence. We tested ...


Nutritional And Economic Analysis Of Small-Scale Agriculture In Imbaburra, Ecuador, Jake Erickson May 2013

Nutritional And Economic Analysis Of Small-Scale Agriculture In Imbaburra, Ecuador, Jake Erickson

All Graduate Theses and Dissertations

Nutritional and Economic Analysis of Small-Scale Agriculture in Imbabura, Ecuador Intervention projects in the developing world normally aim to satisfy either the nutritional needs of a group, or advancing the economic stability, but not both. One of the many issues that may arise by narrowly focusing and creating an aid program is that although a group may be fed, they are not equipped to mitigate risks that will arise after project completion and thus continue or revert back to a malnourished state. A bridge is required to join the economic and nutritional programs to create aid interventions that are sustainable ...


Learning And Power In International Farmer Exchanges, Stephen August Lauer Jan 2013

Learning And Power In International Farmer Exchanges, Stephen August Lauer

Graduate Theses and Dissertations

The "Bridging the Gap" program provides an opportunity to explore the relationships between learning and power in international agricultural development partnerships. A USAID-funded partnership between Iowa State University and Volunteer Efforts for Development Concerns, this farmer-to-farmer program sent groups of Iowan women farmers to Uganda to teach Ugandan women farmers with the objectives that Ugandans would move from subsistence to commercial farming and that both groups would benefit from the cultural exchange. Data were collected primarily through semi-structured qualitative interviews of 28 Ugandan farmers, 7 Iowan farmers, and several program staff, and were analyzed using a grounded-theory approach. This thesis ...


New Tools For Real-Time Study Of Embryonic Development, Lauren M. Browning Jan 2013

New Tools For Real-Time Study Of Embryonic Development, Lauren M. Browning

Theses and Dissertations in Biomedical Sciences

Embryonic development represents one of the most complex and dynamic cellular processes in biology, and plays vital roles in understanding of functions of embryonic stem cells (ESCs) and design of ESC-based therapy. Conventional assays and fluorescence-based imaging methods have been widely used for the study of embryonic development. These conventional methods cannot effectively provide spatial and temporal resolutions with sufficient sensitivity and selectivity that are required to depict embryonic development in vivo in real-time at single-cell and single-molecule resolutions. In this dissertation, we have developed a wide range of innovative tools for real-time study of embryonic development. These new tools ...